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https://forum.kerbalspaceprogram.com/index.php?/topic/168252-elliptical-orbital-mechanics/#comment-3236668 | # Elliptical Orbital Mechanics
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Okay,
I wanted to try and find a way to apply circular motion and gravitational field calculations to elliptical orbits to prove why all orbits must have opposite periapsis and aopsis and only one of each (as oppose to for example two opposite aopsis and two opposite periapsis) but I couldn't do it.
Anyone with more experience give me a hand, it would be handy if the derivation tried to use relatively simple mechanics because I'm second year A level in the UK.
Cheers
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4 hours ago, Whyx said:
Okay,
I wanted to try and find a way to apply circular motion and gravitational field calculations to elliptical orbits to prove why all orbits must have opposite periapsis and aopsis and only one of each (as oppose to for example two opposite aopsis and two opposite periapsis) but I couldn't do it.
Anyone with more experience give me a hand, it would be handy if the derivation tried to use relatively simple mechanics because I'm second year A level in the UK.
Cheers
To explain, difficult.
We need to do a little history, Issac Newton basically described a mysterious force that acted at a distance, and although he did not particularly like the idea he did not have a better explanation and the concept of gravity has stuck since then until Einstein. The concept of general relativity, and so gravity as we are familiar with is a faux force, there is no force acting at a distance. Another faux force we are all familiar with is centripedal acceleration which is not acceleration at all, but comes from the fact that objects are in a non-intertial reference frame.
Our first example exemplifies the first. You have a world that has zero rotation (like venus) and you are standing on the surface. In a moment all the mass becomes a quantum singularity at the center. As you are standing you begin to fall and you are absorbed into the singularity. While you are falling you were in a inertial reference frame, since there was no forces acting on you. Therefore the force you were feeling on the ground was the ground and the electrostatic interactions holding the ground up, all the way to the center of planet, and cooperate as a force acting against your inertia. The reason you feel is because you had potential energy but no kinetic energy. The exact metric is the specific potential energy (SPE it means the energy per unit of mass). Lets say you were standing on a planet that had a radius of 10,000km and standard gravimetric parameter of 1E16 (=Mass * universal gravity constant= mu, written like u but is greek m). The equation actually comes from the integral of MGH which at the microscale determines the moment of energy exchanged at each radius.
SPE=uo/r-u1/r
Between any two radius we can know the specific potential energy gained from a movement to the other. For example if you move from (2-body problem) deep space to 10,000 km SPE is equal 1,000,000 joules per kilogram.
So lets say the you fall from 10,000km to the 'new' singularity, which happens to be 0.01M you would be approaching c.Your apoapsis on this orbit would be the point from which you fell and if that point was infinitesimally small your random motions would have created a periapsis at that point and retruned you to your apoapsis, a perfect line from your starting position to the center of the planet and back. The reason is that the space-time next to the point mass is highly warped by the nearby energies as you approach you need to increase your velocity (inertia) but in fact the only way for inertia to increase in a free fall is our faux friend gravity. You have to think of it like this, the energy in space creates space-time (this is a combination of mass and other forms of energy). If you lack kinetic energy then it draws you in, but if you have enough kinetic energy there is an energy level by which you can leave. As you fall you convert potential energy to kinetic energy allowing you to escape. The kinetic energy you gain is Specific Kinetic energy (SKE). Specific potential and kinetic energy compose the specific mechanical energy of an orbit (as in orbital mechanics).
dSKE=-(uo/r-u1/r) Total SKE = starting V^2/2 + dSKE resulting in a velocity of (2*tSKE)^0.5
If we however pushed your body 1 meter tangential to the radius you would not hit the surface of the point mass, but instead the second faux force would kick in, centripedal acceleration. So there are a couple of logics here. In our reference frame (think stars and galaxies far away) we can define a state which is not in rotation. If you fell from a dead stop circled the point mass and returned back to a different point from which you fell relative to the point mass, then it means the point mass has imparted information . . . energy would not have been conserved. That explains why you return to the same position and altitude but why does the periapsis need to be 180' opposed. The reason is that as you fall through each radius you impart potential energy and gain kinetic energy and as you rise on the other side of the point mass in an exact reversal of the process you gain potential energy at the expense of kinetic energy. Consequently both sides look the same, in practice however this is seldomly true but approximate. This is because in our universe, there are no true 2-body problems. The other issue is that relativity applies, so what appears to be Mercury's starting position to us, is not the starting position when viewed from mercury.
The second logic is an empirical one. Before Newton had applied gravity to the planetary motions Kepler had already noted the elliptical motion of the planets. He also noted that 'massive' bodies were typically close to a foci. IF the central mass (say the sun) is at one of the foci it means that every planets orbit has two symmetrical parts, one that approaches the sun and the other part that moves away.
The equation is this r = l / 1 + e cos (angular position). l is the semilatus rectum, e is the eccentricity. As you know cos 0 = 1 , 0 is the periapsis, the reference position for the ellipse. As you move in either direction from zero, so for example π and -π radians place a satellite exactly at the same distance from the point mass that it orbits (roughly). In an ellipse there are only two unique radius, those that intersect the semi-major axis, all other radii mirror the other half of the ellipse.
How do we connect Kepler and Einstein. [See general relativity]. As you move about an orbit there is an inter-conversion of energy, you fall into a warping of space time but at some point a (the semi-major axis) you have enough energy to remain at a static potential energy level. If by chance SKE has a tangential velocity vector where speed = Vtan and Vtan = SQRT(u/r) then you have a circular orbit. If however you have at a some radial velocity then the satellite will 'cycle' from pE to Apo. There are two ways we could have orbits. if you took a cylinder and sliced it along a diagonal you would have a elliptical shaped object with two equivilant foci. In such a state we assume the mass is at the elliptical center and the satellite would approach the central body twice per orbit.
You should note in the first example that change in PE from deep space (Infinity) to 10,000M is much, much less than the change of PE from 10,000 M to 0.1 M. This 'gravity' acts as a radiative force F=k/r^2. This implies that the warping of space-time is not linear with respect to radius. The decrease in the warping of space slows as one measures further and further away. Consequently the type of ellipse that is more suited is a conic section where the center of the cone is the major foci (central body) and the minor foci is at some distance from the central body. So because the rate of warping relative to distance is not uniform we need a conic section to explain orbital motion, and with a conic section the major body allows only one pass at close distance per orbit.
I should point out the Kepler's laws of planetary motion are a conservative guess. In fact with 100s of years of study since there are lots of n-body corrections. There are a great many places in our solar system where planetoids and other things could reside in stable orbits, but the problem is that massive bodies have a tendency to tweek the orbits of smaller objects, potentially catastrophically, but often throwing them out of our system. The la grange points are examples of places where we can find 'trojan' asteriods, and for jupiter and saturn there are a fair number. But earth and venus have few of these objects. So even n-body solutions are not perfect explanation.
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The form of Kepler's Law that we know can be derrived from Newton's Law of Motion and Gravitation.
The key ideas are :
- Prescribe the forces in derivatives of distance.
- Turn into spherical coordinates.
- Do calculus.
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7 hours ago, YNM said:
The form of Kepler's Law that we know can be derrived from Newton's Law of Motion and Gravitation.
The key ideas are :
- Prescribe the forces in derivatives of distance.
- Turn into spherical coordinates.
- Do calculus.
That's not too bad. I can't really translate UK educational levels, but I remember writing down the derivation for *circular* orbits during a second year university physics exam (had to be done in less than 5-10 minutes just for that question). This can be done with polar coordinates and doesn't require calculus (and thus doesn't explain ellipses nor the area law, but handles the degenerate case of ellipse==circle well). [this may have been deriving gravitation from circular motion, it has been a long time].
Unfortunately polar coordinates are unlikely to remain your friends with ellipses, although it appears that again solving for the degenerate case of ellipse==line works well here, and then showing that orbiting in two orthogonal "lines" forms an ellipse is the method used above (maybe not explicitly, but certainly that is what x and y are doing).
The spherical coordinates might be a bit of an issue. Working from Keplar we can show that everything stays on a plane, and I can see how you can show that Kepler's orbits are stable, but I'd hate to show that every [large/small] body will follow conic sections (and remain on a single plane).
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4 hours ago, YNM said:
The form of Kepler's Law that we know can be derrived from Newton's Law of Motion and Gravitation.
Safe to say, it is very, very involved and intensive to derive so.
The key ideas are :
- Prescribe the forces in derivatives of distance.
- Turn into spherical coordinates.
- Do calculus.
Newton's application works for slow moving bodies around distant stars, it tends to break down as things speed up.
The page needs an awful lot of work to be complete. First GM = u. Assuming that one is a infinitesimally small satellite around a massive central (and far enough away such that relativity does not need to be taken into account) and get rid of m, temporarily.
r = 1 / (u/L) (1 + e Cos O)) versus r = l / (1 + e Cos O) where l is the semi-latus rectum or r = a * (1-e2) / (1 + e Cos O) where l = a * (1-e2) or l = b2/a
for keplerian mechanics a = is the arithmetic mean of Pe and Apo as measured from the center of massive bodies, b is the geometric mean. Both represent the axis of an ellipse. Therefore the semi-latus rectum goes undefined as L/u.
To truly bridge the gap between Kepler and Newton (although neither formulated their math to the above stated description we assume that their understanding was equivalent) you need to convert one understanding to the other.
Here it is, the X axis is the axis that runs from Pe though CB to Apo and also runs along O = 0(2π)- π. It is the axis where Y = 0. The Y axis runs through the systems center of mass therefore it runs through π/2 and 3π/2 each radial to the radius of the semi-latus rectum; it is the axis were X = 0. When Cos (O = π/2) then e Cos O = 0 thus r = 1/(u/L) = L/u (where L is the angular momentum of the orbit, mass reduced in our example). The problem between Kepler and Newton is a discrepancy in the central body that is related to the planets mass, for example Jupiter would pull on the sun gives the sun orbital moment, so that the semi-latus rectum is not at right angles to Jupiter's periapsis through the sun but through the system center. Thus if you are looking at binary stars you cannot reduce the mass.
Therefore there are three (x2) other orbital landmarks. There are a, the radii in which V is equal (u/r)1/2 [Note that for a circular orbit all radii = a]. In terms of the angular distance from the periapsis a is variable. The limit of Oa as e-->0 is Ol this means that as eccentricity increases a is almost always closer the minor focus than the central body. This has to be the case, because for a to have a velocity of (u/r)1/2the and also be eccentric means that the absolute value of the radial velocity vector is large and thus the tangential component of velocity must be small and similar to the velocity at the apoapsis. There is the l radii, where (reduced angular momentum)/u. The third points are r = b, which is more or less trivial since b is a measure from the elliptical center to along the minor axis.
I should point out also the link is incomplete in one regard for the stated purpose. There is no reason that upon leaving O = 0 after completion of an orbital cycle O since the conversion from polar coordinate system makes the assumption that the process is a cycle (IOW its a circular definition), which of course it is, but the Newtonian systems assumes it is a static cycle, in order to do that you need to know whether that stasis has an energy dependence or not; it does. No total energy (information) change is what causes the cycle to be 'a standing wave'.
Here is the reason using the Newtonian system.
*Note: For a Newtonian system (a benefit) you can choose a coordinate reference that is not, say, going to be effected by change, say the position of three far off galaxies that appear at right angles to each others position and whose positions evolve slowly. From that coordinate system you would need two O to define every position in the orbit, one in X-Y and other in X-Z (or Y-Z or all three). This is actually the most thorough way of testing the system, the problem is that it is the most complicated particularly so if you don't place the systems barycenter at X=0, Y =0, Z=0.
Here are the flaws in the Newtonian system.
Information is always leaving and entering the system, the system is never in stasis. Also, the Newtonian system only assumes that matter can contribute to gravity and that energy can change the state. However energy and matter both contribute to gravity. Energy is always entering and leaving the system. For example, the moon's orbit is affected by the water on the surface of the earth (The earth is not a point mass, who knew). The sun is loosing mass via d(hv)/dtc2 . If the sun were to stop converting mass into hv then the water on Earth would freeze, and the moon's orbit would change more slowly (but still change due to perturbations in elevations on Earth). This is an example of the complexity of the system. Another example, a comet behave by Newtonian orbital mechanics until is reaches a certain radius, but strictly Newton does not reduce mass, and yet the comets mass is reduced by solar winds and hv. As a consequence the comets orbit is subject to change or alternatively disappear. In this 2-body problem the larger body is converting mass into both hv and energetic ejecta. The comet in response is converting its mass into the circumsolar atmosphere (compositely know as the wind). A third example, a satellite orbiting the sun is taking pictures of deep space, in doing so most of its reaction wheels and can no longer maintain attitude, by using the remaining reaction wheels and solar panels it braces itself again photon pressure therefore able to take pictures at specific positions in space as the satellite rotates around the sun, by bracing itself against photon pressure it is changing dr/dt. A forth example, a super nova is an object whose fusion pressure is no longer sufficient to keep heavier atoms from accumulating in its deepest core, the core collapses, in that immediate moment the core converts tremendous amounts of a matter to energy. In the exact moment before the star explodes a pulse of space-time energy leaves the core of the star and as energy is converted to light in the subsequent explosion another larger pulse of space-time density radiates from the star. Any object orbiting that star would observe a change of its position relative to the systems center of mass. Finally as the mass ejecta fly by this superman planet the gravity that once held the planet in orbit diffuses into the deepness of space, if it was in a circular orbit it would be free to orbit as an ellipse or a hyperbola and wander the galaxy as an orphan planet. In each of these scenarios the information of the system, but the kinetic energy in the objects has not changed in complete response.
IN the first the moving tides are providing information from the sun transmitted to the earth revealing differences in the viscosity of matter on the surface that rigid matter would not provide. In the second the objects mass is dividing itself and while some of the mass remains in predicted motion, much of the mass is taking a different motion, it is doing so as a consequence of non-gravimetric information the central body is transmitting. In the third example information is provided from humans to adjust the random position of the spacecraft such that different forces balance each other. In the forth example simple newtonian function is not static, the warping of space-time changes several times before the central tenant of the function, that the system center acts as a point mass, becomes invalid and after a time, becomes valid again but with a different mass.
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@PB666 I just linked that site because it seems to be the closest one to what I know. Derivations are usually shown in astronomy books; Fundamentals of Astronomy is one. I have some lecture slides but they're not easy to show here.
Kepler's original formulation have no math form at all AFAIK. It's only through Newton's gravity and motion that one can get those differential form.
Also, Newton's law doesn't work with relativity, so ofc you can't get the relativistic corrections. Haven't seen one derrived through EFE pr tensors or something.
@wumpus Was it through centripetal ? Centripetal is the easiest.
The newtonian derrivation indeed also proves the planar and conic-section nature of the trajectories. It's because of the way the forces works - I could imagine that if the other body were to be assumed moving, you can get a spiral model instead.
In any case, I've always seen the derrivation as "huh" and take it for granted that it is possible to show such, but I take no interest in exploring it any further.
Edited by YNM
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5 hours ago, YNM said:
@PB666 I just linked that site because it seems to be the closest one to what I know. Derivations are usually shown in astronomy books; Fundamentals of Astronomy is one. I have some lecture slides but they're not easy to show here.
Kepler's original formulation have no math form at all AFAIK. It's only through Newton's gravity and motion that one can get those differential form.
Also, Newton's law doesn't work with relativity, so ofc you can't get the relativistic corrections. Haven't seen one derrived through EFE pr tensors or something.
The elliptical mark ups as we use them today were not developed in Keplers time, so the equations used today are sort of projections of the elliptical math that Kepler knew of or expanded up[on.
The required elements of a conic section are a a = semi-major axis, e= eccentricity from which one can draw an ellipse.
Major axis = the longest diameter of the orbit. The specific problem here is a reference point. . . how do you know.
Eccentricity: Angular width of it face at full moon from its closest and furthest points, we would need to know the radius of the earth.
The part astonomers work with such as inclination (i) require the choice of a reference plane, then you need to know the inclination line in that plane and create a cross-reference measure of distance from that line.
From that you need to measure the argument of Periapsis (w). Once you get this far fabrication of an orbital model would be pretty strait forward.
The constant sweep rate is pretty good intuition. For Newtonian orbital mechanics you have the modern vectors and v. If the barycenter of the system is xyz = 0,0,0 then magnitude r is dot product (x,y,z) of its cartesian coordinates and v is the direction of motion perpendicular direction of r, r x v = h (a vector) which is invariant (dot products and cross products are from the 1890s). The sweep rate is roughly 1/2 h. In this system if the ellipse is in X,Y then h projects into Z (its own dimension). Thus the two systems are congruent, in the Newtonian system its more refined however because specific (mass-reduced) angular momentum has a vector. This means any addition of energy to the orbit therefore would change that vector h2/u is however the semi-latus rectum (l) of the orbit with reference to the systems barycenter, this particular component is not derivable from Kepler, but is derivable from Newtonian celestial mechanics. l is important since b is a trivial aspect of the orbital ellipse, and it is possible to predict the orbits using r = l / (1 + e Cosine O). Since both the system center and its satellites would obey this it is possible to map orbits and predict future positions.
In the Newtonian 2-body problem since h can also be made a function of angle r2dO/dt (where V = wr and w = dO/dt) and r = (h2/u) / (1 + e Cosine O): specifically the periapsis is the angular reference point and h2/u = L/m, there is the immediate consequence that since h is constant and can be related to r that the ellipse cannot evolve in any direction without the change in energy.
To see this, for the inclination of an orbit to change h (which is also a direction vector) would have to change, this is a constant. The periapsis then could change in the inclination plane. There are two ways to do this, the periapsis could change its magnitude, but that changes v without changing r (at the change point) this means magnitude of h changes, you would have to a another change at 180' to change v again and r to maintain h' this however would change eccentricity (making it circular). You could then go to a third point and burn out to the original rmax, then go to rmax and draw in the rmin to the original pe. h would not have remained but would have been restored but no r = (h2/u) / (1 + e Cosine O) would be invalid because O = 0 is no longer the periapsis.
To be clear apsidal precession occurs in orbits, its one of the factors that contributes to the ice ages. And it occurs without any energy being put into the system, but the system in n-body, which means that energy is being transferred in the system from one orbit to the next and back again. Basically every year Ope, new = Ope, old + .000056 radians. This precession occurs as a consequence of the effects of the major planets in the solar System, namely Jupiter and Saturn. So this goes to a frequent disclaimer about h (or L) that h is local and not infinite. If we forget about relativistic differences, the two major problems are, for satellites traveling in LEO around the Earth, that the earth is not a point mass nor is it of uniform density, this alters u/r2, that external, other non-centric celestials, perturb orbits. Finally for LEO orbits as orbital speed increases so does the effect of drag, both increase in proximity to planetary surfaces, so that loses of h can be permanent.
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• Create New... | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8727899193763733, "perplexity": 727.7338236899}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 5, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2023-06/segments/1674764500151.93/warc/CC-MAIN-20230204173912-20230204203912-00700.warc.gz"} |
http://lkozma.net/blog/nonlinear-speedometer/ | # Nonlinear speedometer
As everyone knows, excessive speed is one of the main causes of traffic accidents. One of the reasons for reckless speeding is that when we think of the possible impact of a collision, our intuition fools us. We tend to assume that if we go twice as fast (say, at 80 km/h instead of 40 km/h), then the impact of a collision will be twice as large. In fact, the impact of a collision is proportional not to the speed (V), but to the kinetic energy of the vehicle (m/2 * V²), which is transformed to work as the car decelerates to zero. Here m is the mass of the vehicle, which we cannot do much about, but the other term is the square of the velocity. This means that the “impact” of hitting a wall at 80 km/h is four times as large as that of the same collision at 40 km/h.
To capture this intuition, the idea of this post is a speedometer design, that scales as the square of the velocity, to give the driver a more realistic view of the effects of speeding.
### Notes:
• after sketching this drawing, I found that in 1995 Goetz Kluge was thinking along similar lines and produced a similar design. There are however some differences – see next.
• besides showing the speed in the more familiar, circular layout, I also made the decision to draw the smaller lines at uniform density (i.e. they are spaced proportionally to the kinetic energy, not to the velocity). This design might make it harder to estimate the exact speed, say between 40 km/h and 50 km/h, but it makes the increased kinetic energy easier to grasp – when we speed from 120 km/h to 130 km/h, the hand crosses more “small lines” than from 20 km/h to 30 km/h.
• while I haven’t seen a similar speedometer in any real car, some of the existing speedometers are in fact nonlinear. Unfortunately, they seem to achieve the exact opposite effect to the design shown above. See this example. On the linked image, and in many other modern speedometers, the manufacturers try to put more resolution in at the lower half of the range, dilating the velocities between 0 and 80. My guess is that car makers do this, because the car accelerates faster at low speeds, so dilating the lower range makes the hand movement seem more uniform at all speeds – this is probably aesthetically more pleasing, but it might come at a cost of an increased (false) sense of security, and in effect a reduced safety.
(I got this exactly wrong – thanks Tobias for pointing it out – it is actually the opposite, on the proposed speedometer design, the hand would move more evenly – so besides being safer, it would be more aesthetical as well, the only downside seems to be the reduced resolution in the low range) | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8232093453407288, "perplexity": 464.67062202626784}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-13/segments/1490218191444.45/warc/CC-MAIN-20170322212951-00661-ip-10-233-31-227.ec2.internal.warc.gz"} |
http://umj.imath.kiev.ua/authors/name/?lang=en&author_id=4316 | 2019
Том 71
№ 11
# Leis Azar
Articles: 1
Article (Russian)
### The best $L_1$-approximations of classes of functions defined by differential operators in terms of generalized splines from these classes
Ukr. Mat. Zh. - 1998. - 50, № 11. - pp. 1443-1451
For classes of periodic functions defined by constraints imposed on the $L_1$-norm of the result of action of differential operators with constant coefficients and real spectrum on these functions, we determine the exact values of the best $L_1$-approximations by generalized splines from the classes considered. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.37754878401756287, "perplexity": 737.2138049289911}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-51/segments/1575540536855.78/warc/CC-MAIN-20191212023648-20191212051648-00256.warc.gz"} |
https://repository.kaust.edu.sa/handle/10754/667480 | Except where otherwise noted, this item's license is described as Archived with thanks to Research Square | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9949912428855896, "perplexity": 3222.13625701825}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572304.13/warc/CC-MAIN-20220816120802-20220816150802-00589.warc.gz"} |
http://support.fletcherpenney.net/discussions/problems/849-mmd-title-to-latex | # MMD title to Latex
#### Guillaume
31 Jul, 2017 05:28 PM
Hello,
When I compile my writings with Scrivener and MMD syntax in Latex my titles appear like this:
MMD: #####L'eau de mer#####
Latex:
\ Subsubsection {L'eau de mer}
\ Label {l'eau de mer}
However, when compiling Latex in pdf, errors appear every time an apostrophe is in the \ label command.
Is there a way to automatically put a label without apostrophe, or to make sure that label is not taken into account when compiling in pdf?
The same problem appears with quotation marks and any other special signs.
I assume that \ label does not take these signs into account.
What should I do to stop having these errors when I compile MMD into Latex ?
Another question:
Scrivener with MMD syntax apparently compiles latex with the natbib package (quote appears with \ citep). However, I use Bliblatex (command \ cite), is it possible to set Scrivener and MMD parameters with Biblatex to have the \cite command?
MMD:
[#exemple]
Latex:
\footnote{~\citep{exemple}}
Thank you.
Regards,
Guillaume Martins
1. Support Staff Posted by fletcher on 31 Jul, 2017 11:21 PM
I'm not sure what version you're using, but you shouldn't get those results with MultiMarkdown. Whatever you're using is either not MMD, or is really old.
v 4.7.1:
\subsubsection{L'eau de mer}
\label{leaudemer}
v 5.4:
\subsubsection{L'eau de mer}
\label{leaudemer}
v 6.1.0:
\subsubsection{L'eau de mer }
\label{leaudemer}
You should update your MMD to a newer version (I recommend v6, but a few users still need v5).
As for citations, MMD uses ~\citep{} and \citet{}. You can modify MMD to do whatever you like, however -- that's the beauty of open source software! Or you can switch to using natbib -- it seemed to have a lot more flexibilty when I first looked at it.
Hope this helps,
Fletcher
2. fletcher closed this discussion on 22 Aug, 2017 01:16 AM.
Comments are currently closed for this discussion. You can start a new one.
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01 Nov, 2020 11:43 PM Numbered lists 19 Oct, 2020 12:31 AM Just starting with MMD on Windows 03 Oct, 2020 05:14 PM Uninstall 19 Jul, 2020 12:44 AM "latex input:" metadata command not working 11 Jul, 2020 11:54 PM Generating LaTeX labels separately from captions used in List of Tables/Figures | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8349209427833557, "perplexity": 9142.927720414229}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-50/segments/1606141181482.18/warc/CC-MAIN-20201125071137-20201125101137-00661.warc.gz"} |
https://winintro.ru/windowspowershellhelp.en/html/a7665c41-1092-4617-8715-797bbb70ac3f.htm | FileSystem
C, D
# DETAILED DESCRIPTION
The Windows PowerShell FileSystem Provider lets you get, add, change, clear, and delete files and directories in Windows PowerShell.
The FileSystem Provider exposes Windows PowerShell drives that correspond to the logical drives configured on your computer, including drives mapped to network shares. For example, a computer with one floppy disk drive, one hard disk drive, and one mapped network shared directory might have drives named A, C, and Z. The FileSystem Provider exposes Windows PowerShell drives that correspond directly to A, C, and Z, allowing you to reference these drives from within Windows PowerShell. For example, to reference drive C, you use C:, as shown in the following example:
The command returns all the contents on the C drive, including files and directories. When you reference a specific directory or file through the FileSystem Provider, you must provide the information necessary to identify that directory or file. This means that, in some cases, you must provide a fully qualified name. A fully qualified name includes the drive name (along with a colon), any directory and subdirectory names, and the file name (when applicable). For instance, the following example shows the fully qualified name for the Shell.dll file, which is located in the System32 subdirectory of the Windows directory on the C drive:
c:\windows\system32\shell.dll
As you can see, each element of the fully qualified name is separated by a backslash (\). Windows PowerShell also allows you to use a forward slash (/) to be consistent with a variety of other shells.
In some cases, you do not need to supply a fully-qualified name when referencing a file or directory. For example, if you want to access a file in your current working location, you need to provide only the file name. If your current working location is c:\windows, you can view a list of all the .dll files in that directory by using the following command:
Get-ChildItem *.dll
If your working directory is something other than c:\windows, such as c:\program files\Windows PowerShell, your command might need to include the fully qualified name:
Get-ChildItem c:\windows\*.dll
In some cases, you can use relative references to a location. If your working location is c:\windows, and you want to view a list of .dll files in the c:\windows\system32 directory, you can use the following command:
Get-ChildItem .\system32\*.dll
The period before \system32 represents the current working location.
In some situations, your current working location will be on a drive other than a FileSystem drive. If this is the case, you must always include the name of the target drive in your reference. For example, suppose that your current working location is the env: drive. To view the contents of the C drive, you would use the following command:
# EXAMPLES
### Navigating the File System
#### -------------------------- EXAMPLE 1 --------------------------
This command gets the current location:
```get-location
```
The Get-Location cmdlet includes the functionality of commands like the cd command in the Windows Command Prompt and the pwd command in UNIX. For more information, type: get-help get-location
#### -------------------------- EXAMPLE 2 --------------------------
This command sets the current location:
```set-location C:
```
### Getting File and Directory Information
#### -------------------------- EXAMPLE 1 --------------------------
This command gets all the files and directories in the current directory:
```get-childitem
```
By default, the Get-ChildItem cmdlet does not recurse. If files and folders are present in the current directory when you run this command, a System.IO.FileInfo object and a System.IO.DirectoryInfo object are returned.
#### -------------------------- EXAMPLE 2 --------------------------
This command gets all the files and directories in the current directory by using Get-ChildItem:
```get-childitem | where-object {!\$_.psiscontainer}
```
It pipes the results to Where-Object, which examines the PSIsContainer property and lets only the objects that are not (!) containers through the pipeline.
#### -------------------------- EXAMPLE 3 --------------------------
This command gets all the files and directories in the current directory by using Get-ChildItem. It pipes the results to Where-Object, which examines the PSIsContainer property and lets only the objects that are containers through the pipeline.
```get-childitem | where-object {\$_.psiscontainer}
```
#### -------------------------- EXAMPLE 4 --------------------------
This command gets all the files and directories in the current directory by using Get-ChildItem:
```get-item -path a | format-list *
```
It pipes the results to the Where-Object cmdlet, which examines the PSIsContainer property and lets only the objects that are containers through the pipeline.
#### -------------------------- EXAMPLE 5 --------------------------
This command uses the Get-Item cmdlet to get information about the Test.txt file:
```get-item -path test.txt | format-list *
```
The Format-List cmdlet is used to display all the properties of the resulting object.
### Copying Files and Directories
#### -------------------------- EXAMPLE 1 --------------------------
This command copies the A.txt file from the C:\A directory to the C:\A\Bb directory:
```copy-item -path C:\a\a.txt -destination C:\a\bb\a.txt
```
It overwrites files in the destination directory without prompting for confirmation.
#### -------------------------- EXAMPLE 2 --------------------------
This command copies all the files in the C:\A\Bb directory that have the .txt file name extension to the C:\A\Cc\Ccc\ directory:
```copy-item -path C:\a\bb\*.txt -destination C:\a\cc\ccc\
```
It uses the original names of the files. The command overwrites the existing files in the destination directory without prompting for confirmation.
#### -------------------------- EXAMPLE 3 --------------------------
Copies all the directories and files in the C:\a directory to the C:\c directory. If any of the directories to copy already exist in the destination directory, the command will fail unless you specify the Force parameter.
```copy-item -path C:\a\* -destination C:\c -recurse
```
### Moving Files and Directories
#### -------------------------- EXAMPLE 1 --------------------------
This command moves the C.txt file in the C:\A directory to the C:\A\Aa directory:
```move-item -path C:\a\c.txt -destination C:\a\aa
```
The command will not automatically overwrite an existing file that has the same name. To force the cmdlet to overwrite an existing file, specify the Force parameter.
#### -------------------------- EXAMPLE 2 --------------------------
This command moves the C:\A directory and all its contents to the C:\B directory:
```move-item -path C:\a -destination C:\b
```
You cannot move a directory when that directory is the current location.
### Managing File Content
#### -------------------------- EXAMPLE 1 --------------------------
This command appends the "test content" string to the Test.txt file:
```add-content -path test.txt -value "test content"
```
The existing content in the Test.txt file is not deleted.
#### -------------------------- EXAMPLE 2 --------------------------
This command gets the contents of the Test.txt file and displays them in the console:
```get-content -path test.txt
```
You can pipe the contents of the file to another cmdlet. For example, the following command reads the contents of the Test.txt file and then supplies them as input to the ConvertTo-HTML cmdlet: get-content -path test.txt | convertto-html
#### -------------------------- EXAMPLE 3 --------------------------
This command replaces the contents of the Test.txt file with the "test content" string:
```set-content -path test.txt -value "test content"
```
It overwrites the contents of Test.txt. You can use the Value parameter of the New-Item cmdlet to add content to a file when you create it.
### Managing Security Descriptors
#### -------------------------- EXAMPLE 1 --------------------------
This command returns a System.Security.AccessControl.FileSecurity object:
```get-acl -path test.txt | format-list -property *
```
#### -------------------------- EXAMPLE 2 --------------------------
This command returns a System.Security.AccessControl.DirectorySecurity object:
```get-acl -path test_directory | format-list -property *
```
### Creating Files and Directories
#### -------------------------- EXAMPLE 1 --------------------------
This command creates the Logfiles directory on the C drive:
```new-item -path c:\ -name logfiles -type directory
```
#### -------------------------- EXAMPLE 2 --------------------------
This command creates the Log2.txt file in the C:\Logfiles directory and then adds the "test log" string to the file:
```new-item -path c:\logfiles -name log.txt -type file
```
#### -------------------------- EXAMPLE 3 --------------------------
Creates a file called Log2.txt in the C:\logfiles directory and adds the string "test log" to the file.
```new-item -path c:\logfiles -name log2.txt -type file -value "test log"
```
### Renaming Files and Directories
#### -------------------------- EXAMPLE 1 --------------------------
This command renames the A.txt file in the C:\A directory to B.txt:
```rename-item -path c:\a\a.txt -newname b.txt
```
#### -------------------------- EXAMPLE 2 --------------------------
This command renames the C:\A\Cc directory to C:\A\Dd:
```rename-item -path c:\a\cc -newname dd
```
### Deleting Files and Directories
#### -------------------------- EXAMPLE 1 --------------------------
This command deletes the Test.txt file in the current directory:
```remove-item -path test.txt
```
#### -------------------------- EXAMPLE 2 --------------------------
This command deletes all the files in the current directory that have the .xml file name extension:
```remove-item -path *.xml
```
### Starting a Program by Invoking an Associated File
#### -------------------------- EXAMPLE 1 --------------------------
The first command uses the Get-Service cmdlet to get information about local services.
It pipes the information to the Export-Csv cmdlet and then stores that information in the Services.csv file.
The second command uses Invoke-Item to open the Services.csv file in the program associated with the .csv extension:
```get-service | export-csv -path services.csv
invoke-item -path services.csv
```
# DYNAMIC PARAMETERS
Dynamic parameters are cmdlet parameters that are added by a Windows PowerShell provider and are available only when the cmdlet is being used in the provider-enabled drive.
### Encoding <Microsoft.PowerShell.Commands.FileSystemCmdletProviderEncoding>
Value Description
Unknown
The encoding type is unknown or invalid. The data can be treated as binary.
String
Uses the encoding type for a string.
Unicode
Encodes in UTF-16 format using the little-endian byte order.
Byte
Encodes a set of characters into a sequence of bytes.
BigEndianUnicode
Encodes in UTF-16 format using the big-endian byte order.
UTF8
Encodes in UTF-8 format.
UTF7
Encodes in UTF-7 format.
ASCII
Uses the encoding for the ASCII (7-bit) character set.
### Delimiter <System.String>
Specifies the delimiter to use when reading the file. The default is "\n" (end of line).
### Wait <System.Management.Automation.SwitchParameter>
Waits for content to be appended to the file. If content is appended, it returns the appended content. If the content has changed, it returns the entire file.
When waiting, Get-Content checks the file once each second until you interrupt it, such as by pressing CTRL+C. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8222507238388062, "perplexity": 6981.690445476403}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-25/segments/1623488538041.86/warc/CC-MAIN-20210623103524-20210623133524-00535.warc.gz"} |
https://www.arxiv-vanity.com/papers/0906.1772/ | ###### Abstract
Determining the physical Hilbert space is often considered the most difficult but crucial part of completing the quantization of a constrained system. In such a situation it can be more economical to use effective constraint methods, which are extended here to relativistic systems as they arise for instance in quantum cosmology. By side-stepping explicit constructions of states, such tools allow one to arrive much more feasibly at results for physical observables at least in semiclassical regimes. Several questions discussed recently regarding effective equations and state properties in quantum cosmology, including the spreading of states and quantum back-reaction, are addressed by the examples studied here.
IGC–09/6–2
Effective Constraints for Relativistic Quantum Systems
Institute for Gravitation and the Cosmos, The Pennsylvania State University,
104 Davey Lab, University Park, PA 16802, USA
## 1 Introduction
One of the key issues in quantizations of fundamental theories, which due to their covariance properties are systems with gauge freedom generated by constraints, is the determination of physical observables. They must satisfy the constraint equations and be invariant under gauge transformations. For canonical quantum theories, solving constraints is traditionally done at the state level: one constructs a physical Hilbert space of states annihilated by the constraint operator(s) and equipped with an invariant inner product. Explicit constructions can be done in some special cases by different methods.
Since explicit derivations are possible only in specific cases, it is not always clear whether the results are generic or mere artefacts of the simple models used. It is therefore important to have approximate methods for a wider range of cases, or at least to be able to perturb around known solvable ones while still ensuring that the constraints are solved and the observables are gauge invariant. It turns out that such perturbation schemes are most feasible if one deals with the observables directly, such as expectation values, side-stepping the computation and physical normalization of states. This procedure gives rise to canonical effective equations and constraints [1, 2].
A procedure for effective constraints has been formulated in [2] and applied to parameterized non-relativistic systems with a constraint where is the momentum of time and the Hamiltonian. (The concepts and results are reviewed briefly below.) It was shown that the physical observables in suitable regimes, including semiclassical ones, can be determined without making use of a physical inner product but instead through implementing reality conditions for quantum variables such as fluctuations, correlations and higher moments. For applications of these methods to quantum gravity and cosmology one has to extend them to relativistic systems, offering one additional subtlety: constraints would now be of the form , requiring one to take a square root and to make sign choices. Mathematically, for instance, the question is how to precisely define at the operator level. This may not be obvious if the operator has a complicated spectrum or is not positive definite. Physically, one must decide how to treat and separate positive and negative frequency solutions corresponding to the two solutions . (See e.g. [3, 4] for discussions of relativistic systems.)
For a time-independent Hamiltonian, it turns out that one can, at least for semiclassical purposes, simply use as the effective Hamiltonian [5, 6] without absolute values, even if is not positive definite. One only has to ensure that the initial values used in the effective equations of motion correspond to an initial state supported on a part of the spectrum of with a definite sign. On such a state and with a self-adjoint , if the state is supported only on the positive part of the spectrum of , and if the state is supported only on the negative part. Since the Hamiltonian is preserved, these statements will hold true throughout the whole evolution and there is no need for an absolute value in the effective Hamiltonian. This fact has been made use of in several recent derivations of effective equations in quantum cosmology, where the relevant versions of are not positive definite [7, 8].
In those models, deparameterization was performed using as an internal time from a free, massless scalar . The same types of models also allow the construction of a physical Hilbert space at the state level [9, 10], with the results in agreement with those obtained from effective equations. Most interesting from the cosmological perspective is, however, a system where the scalar has a non-trivial potential or at least a mass term. This has two immediate implications: in general, one can no longer deparameterize globally since the solutions for the scalar would not be monotonic in the time coordinates, and the Hamiltonian would no longer be (internal) time independent. Positivity can no longer be ensured just by an initial condition, and using as an effective Hamiltonian without an absolute value may then seem questionable. Explicitly using an absolute value, on the other hand, would make a derivation of the effective equations more complicated. At this stage, a direct treatment of effective constraints for relativistic systems without deparameterization becomes relevant. This is what we present in the current paper.
We will consider in detail models of relativistic particles and properties of observables in their quantum theories. In the massive case, for instance, we are dealing with the quantization and implementation of a constraint . For physical states, the expectation value
⟨C⟩=p2t+(Δpt)2−p2−(Δp)2−m2
must vanish and thus represents a quantum constraint. (We will notationally identify classical degrees of freedom with the expectation values to simplify the notation and to show the relation between classical terms and quantum corrections. Thus, and .) As we will see in more detail below, there are additional independent constraints since expressions such as must also vanish for physical states. Allowing all possible factors to the left of , this presents a constrained system of infinitely many constraints for infinitely many quantum variables given by the moments of a state. The combined system of all constraints must be solved to find observable results, which is feasible in semiclassical regimes where only a finite set of moments suffices to characterize a state approximately. The same kind of approximation also allows one to include potentials within the constraint, which may be explicitly time-dependent. We will exploit this to justify the procedures used in quantum cosmology for deparameterized systems with time-dependent potentials, as developed in [11, 12, 13].
Another question of interest is that of the spreading of states and quantum back-reaction of fluctuations and higher moments on the expectation values. If we compare the effective constraint written above, which contains only the second order moments in addition to the expectation values, with the effective Hamiltonian of the corresponding deparameterized system,
⟨H⟩ = ⟨√p2+m2⟩=⟨√(p+(p−p))2+m2=√p2+m2+∞∑n=21n!∂n√p2+m2∂pn⟨(p−p)n⟩ (1) = √p2+m2+m2(Δp)2(p2+m2)3/2−3m2m2−4p2(p2+m2)7/2⟨(p−p)3⟩+⋯
with a whole formal Taylor series that includes higher moments, different coupling terms between the expectation values and the moments seem to be implied. Then, back-reaction might seem different in these two treatments, apparently making them incompatible. By our specific constructions in this paper we will reconcile these apparent disagreements, and provide an illustration by numerical solutions in a specific example (App. B). This is also important for quantum cosmology, where quantum back-reaction is crucial to the understanding of how a quantum state evolves toward and possibly through the big bang and how much of the pre-big bang state can be reconstructed [14, 15].
## 2 Effective constraints
In a canonical effective description, the dynamics of a quantum system with degrees of freedom is formulated in terms of the expectation values, i.e. the evaluations of a state functional in the elements of an algebra generated by basic operators and , . This whole set of infinitely many variables can be conveniently split into the expectation values of the basic operators, such as and , , together with the infinitely many moments of the form
G{aj},{bj}=⟨n∏i=1(qi−⟨qi⟩)ai(pi−⟨pi⟩)bi⟩Weyl
where the subscript “Weyl” denotes the totally symmetric ordering of all factors involved. Between all these variables a Poisson bracket is defined following from the algebra of commutation relations:
{⟨A⟩,⟨B⟩}=⟨[A,B]⟩iℏ (2)
extended using linearity and the Leibniz rule.
At second order, , this set of moments includes all fluctuations and covariances. In semiclassical regimes, moments fall off at least as such that only low orders need to be considered for the first approximation to quantum effects. Below we will employ the notation for fluctuations and for covariances, which may make second order equations easier to interpret.
Any operator gives rise to a function on the space of states, which can be expressed in terms of the moments by Taylor expanding
⟨C(qi,pj)⟩=⟨C(qi+(qi−qi),pj+(pj−pj))⟩ (3)
in and as in (1). If is a constraint operator, (3) must vanish on physical states and thus is a constraint on the quantum phase space.
A single constraint on the phase space removes one pair of variables, but not the whole tower of moments associated with it in the quantum phase space. For a complete reduction one has to make use of additional constraints, provided by the set of phase space functions which must also vanish on physical states. These functions are in general independent from the quantum constraint as functions of expectation values and moments. As shown in [2], this set of constraints remains first class. (Note that we do not order the products of the operators in the constraints symmetrically to ensure that the constraint operator acts directly on the state. As a result, in some cases one has to deal with complex-valued constraints requiring reality conditions for physical observables. This has been discussed in [2] and will also be seen in more detail in the examples below.)
Given such a system of constraints on the quantum phase space, one can proceed in the classical way and find the reduced quantum phase space of observables or solve the constraints and fix the gauge. At this stage, it is convenient (but not required) to decide which internal time variables among the should be used. Since a quantization of the corresponding deparameterized system, if it exists, would not give rise to any moment involving an operator of or , solving the constraints must remove all moments including at least one factor of or from the original quantum phase space. That this indeed happens was verified to second order of the parameterized non-relativistic particle in [2]. In that case, there was a single linear term in the constraint, such that all -moments , , and can be removed by solving the system of constraints, to second order:
⟨(q−q)C⟩ = Δ(qpt)+pMiℏ2+pMΔ(qp)=0 ⟨(t−t)C⟩ = pMΔ(pt)+Δ(tpt)+iℏ2=0 ⟨(pt−pt)C⟩ = (Δpt)2+pMΔ(ppt)=0 ⟨(p−p)C⟩ = Δ(ppt)+pM(Δp)2=0.
This leaves the moments , and , which are removed by factoring out the gauge flow, or simply by setting them to zero as a well-defined set of gauge-fixing conditions. (Note that a smaller number of gauge fixing conditions than constraints is required because the second order moments satisfy a Poisson algebra which is degenerate from the symplectic point of view; see [16] for some notions of constrained systems in the non-symplectic case. Additionally, setting the fluctuation to zero is consistent with the generalized uncertainty relation
(Δt)2(Δpt)2−Δ(tpt)2≥ℏ24
since -correlations are required by the constraints, especially with the gauge fixing condition , to be imaginary and of just the right size to saturate the uncertainty relation.) After solving the constraints and fixing the gauge, observable moments are recovered on which physical reality conditions can be imposed.
## 3 Free relativistic particle
Classically a free relativistic particle is described by a single constraint
C=p2t−p2−m2
on the phase space coordinatized by two canonical pairs and .333We assume the units have been chosen so that both length and momentum have the units of the square root of action (e.g. geometrized units). For the quantum version we consider the unital associative algebra generated by four basic elements subject to the canonical commutator relations. That is, consists of (countable) sums of polynomials of the form ; terms with a different ordering may be expressed using the commutation relations
[t,pt]=iℏ1,[q,p]=iℏ1.
There is no product-ordering ambiguity in the case of the above constraint and it is naturally identified with an element of . As the equivalent of Dirac’s condition we demand that the constraint has a vanishing right action on the states, which in our case are complex linear functions , this implies that ; henceforth we drop explicit reference to and write this condition as for the expectation value in a physical state . In order to impose all these conditions systematically we take the previously mentioned basis in and impose the constraint via an infinite (but countable) set of conditions
⟨tipjtqkplC⟩=0. (4)
We reduce the above infinite system of equations using the same method that was previously employed for a Newtonian particle [2]—a semiclassical expansion based on the hierarchy
⟨(t−⟨t⟩)i(pt−⟨pt⟩)j(q−⟨q⟩)k(p−⟨p⟩)l⟩Weyl∝ℏ12(i+j+k+l)
of moments.
### 3.1 Constraints at second order
In what follows, we assume a semiclassical state and drop the terms of order and above, keeping the terms of order and below. This will suffice to demonstrate the feasibility of our methods for relativistic systems. To this order our system is described by fourteen independent functions: four expectation values of the form ; four spreads of the form and six covariances of the form . (Poisson brackets between all these variables are listed in App. A.) The infinite system of constraint functions is reduced to just five non-trivial conditions
C = ⟨C⟩=p2t−p2−m2+(Δpt)2−(Δp)2=0 Ct = ⟨(t−⟨t⟩)C⟩=2ptΔ(tpt)+iℏpt−2pΔ(tp)=0 Cpt = ⟨(pt−⟨pt⟩)C⟩=2pt(Δpt)2−2pΔ(ptp)=0 Cq = ⟨(q−⟨q⟩)C⟩=2ptΔ(ptq)−2pΔ(qp)−iℏp=0 Cp = ⟨(p−⟨p⟩)C⟩=2ptΔ(ptp)−2p(Δp)2=0. (5)
Note that the semiclassical hierarchy of variables is critical to the above reduction in the number of constraint conditions. In particular, implies that , which in turn implies that the combination of the expectation values is of order on the constraint surface. In other words, the classical constraint is satisfied to order . The terms of the form and are then of order and should be dropped in our present treatment. The complete infinite system of constraint functions is a closed Poisson algebra—or, in the language of classical constraint analysis, a first-class system [17]. In general, due to the nature of the above truncation one would expect the reduced system of constraints to remain closed only to order . In our case the Poisson algebra of the truncated set of constraint functions—displayed in Table 1—is exactly closed with respect to the bracket.
To solve the constraint system we eliminate five variables using the five conditions from (5). Specifically, we eliminate the five quantum variables associated with , having in mind that will be chosen as time in a deparameterized treatment. We start by noting that gives
0=p2t(Δpt)2−pptΔ(ptp). (6)
However implies
ptΔ(ptp)=p(Δp)2
and substituted in (6) gives
0=p2t(Δpt)2−p2(Δp)2.
Finally, eliminating through we obtain a quadratic equation in
((Δpt)2)2−(Δpt)2(p2+m2+(Δp)2)+p2(Δp)2=0
with two solutions
(Δpt)2=12(p2+m2+(Δp)2±√(p2+m2+(Δp)2)2−4p2(Δp)2).
In order to see whether either solution is compatible with the hierarchy assumed by the semiclassical approximation, we expand the solution to order . One finds
(Δpt)2 = 12(p2+m2)(1+(Δp)2p2+m2±√1+(Δp)2(2m2−2p2+(Δp)2)(p2+m2)2) = 12(p2+m2)(1±1+(Δp)2(p2+m2)2(p2+m2±(m2−p2))+O((Δp)4)).
Looking at the solution with the “” sign we see the following leading order behavior
(Δpt)2=p2+m2+O(ℏ)
which is inconsistent with the assumption that is of order . The solution with the “” sign leads to
(Δpt)2=p2(Δp)2p2+m2+O((Δp)4)
which is of order and therefore consistent with the semiclassical approximation. Substituting the latter solution back into the constraint conditions (5) we obtain two sets of solutions
pt = ±E Δ(tpt) = ±pEΔ(tp)−iℏ2 (Δpt)2 = p2+m2+(Δp)2−E2 Δ(ptq) = ±pE(Δ(qp)+iℏ2) Δ(ptp) = ±pE(Δp)2 (7)
where
E=1√2(p2+m2+(Δp)2+√(p2+m2+(Δp)2)2−4p2(Δp)2)12.
By rearranging the terms in the above expression one can easily verify that when reality and positivity of the physical variables are imposed (see Section 3.2). One recovers the usual relativistic dispersion relation where energy equals if one assumes a “momentum eigenstate”, that is if one sets the spread in momentum .
### 3.2 Gauge freedom
The truncated system of constraints (5) is equivalent (when consistency with the semiclassical approximation is evoked) to the restriction to two disjoint surfaces, each one corresponding to a choice of sign in (7). Each surface is described by an equivalent set of “linearized” constraints
C1± = pt±E C2± = (Δpt)2−p2−m2−(Δp)2+E2 C3± = Δ(ptp)±pE(Δp)2 C4± = Δ(ptq)±pE(Δ(qp)+iℏ2) C5± = Δ(tpt)±pEΔ(tp)+iℏ2. (8)
The above constraint conditions can be expressed as sums of the conditions in (5) and therefore form a first class system. Additionally, for the calculations to follow it is useful to note that , , , and are first class functions with respect to either set of constraints. This can ultimately be traced back to the fact that . It follows that , which is a function of and only, is also first class.
On the constraint surfaces the “linearized” constraints can be used to eliminate the five variables , , , , . At this stage there remain four degrees of freedom associated with the algebra elements generated by . These will be treated as gauge parameters associated with the time evolution of the system. From this point of view, one has a four-parameter space to choose from when it comes to the evolution of the “physical variables” (i.e. those associated with the algebra generated by and alone). Viewing our system expanded to second order in quantum variables as a classical constrained system, the evolution on the “physical variables” — , , , , — may be generated by any constraint function of the form
CHam=∑iμiCi± (9)
where the multipliers are arbitrary functions of the physical variables. The presence of several constraints, all associated with the classical Hamiltonian, means that a priori there is no unique time parameter. Depending on the choice of gauge, any combination of with moments involving can play the role of time.
At this stage we would like to restrict the gauge freedom down to a single parameter and to interpret the first class flow in the direction of as the dynamical evolution of the system. This may be accomplished by introducing three gauge choices
ϕ1 = (Δt)2−f1(q,p,(Δq)2,Δ(qp),(Δp)2)=0 ϕ2 = Δ(tq)−f2(q,p,(Δq)2,Δ(qp),(Δp)2)=0 ϕ3 = Δ(tp)−f3(q,p,(Δq)2,Δ(qp),(Δp)2)=0
with functions , and to be determined. We define as the first class function (9) that remains after the gauge conditions have been introduced. It must therefore be a combination of the original constraint functions as in equation (9) that in addition satisfies
{CHam,ϕi}≈0,i=1,2,3
where the symbol ‘’ denotes equality on the surface defined by imposing both the constraints and the gauge conditions. A simple set of such conditions that was also used in Ref. [2] to recover the deparameterized dynamics of a Newtonian particle is provided by
ϕ1 = (Δt)2=0 ϕ2 = Δ(tq)=0 ϕ3 = Δ(tp)=0. (10)
(Again, is consistent with the uncertainty relation since from .)
Let be the surfaces defined by simultaneously imposing the constraints and the above gauge conditions. These are coordinatized by the physical variables—, , , , —and the one remaining gauge degree of freedom—. It is straightforward to verify that the variables , and generate a Poisson ideal of the algebra of physical and gauge variables (i.e. the variables that do not involve ). That is, is a sum of gauge conditions with some coefficients. It follows that on the gauge-fixing conditions have a trivial Poisson algebra and a vanishing Poisson bracket with the remaining free variables. It is not difficult to see that remains first class on . Since is a function of the “physical” variables only, and so
{ϕi,C1±}={ϕi,pt±E}≈0.
Furthermore, writing one can quickly establish that also remains first class but has a vanishing Poisson flow on .
The remaining set of surface-defining conditions composed of , , and is second class for all admissible values of the physical variables. This can be seen by relabeling the conditions as , , , , , and looking at the Poisson bracket matrix . On the components of the matrix are
Δ≈⎛⎜ ⎜ ⎜ ⎜ ⎜ ⎜ ⎜ ⎜ ⎜ ⎜ ⎜ ⎜ ⎜⎝0002iℏ±pE(iℏ+2Δ(qp))±2pE(Δp)2000012iℏ−Δ(qp)−(Δp)20000−(Δq)2−12iℏ−Δ(qp)−2iℏ00000∓pE(iℏ+2Δ(qp))Δ(qp)−12iℏ(Δq)2000∓2pE(Δp)2(Δp)212iℏ+Δ(qp)000⎞⎟ ⎟ ⎟ ⎟ ⎟ ⎟ ⎟ ⎟ ⎟ ⎟ ⎟ ⎟ ⎟⎠.
Calculating the determinant one obtains the same result for both choices of the sign
det[Δ]≈−4ℏ2[ℏ416+(Δ(qp))4+2((Δp)2(Δq)2−ℏ24)((Δp)2(Δq)2−(Δ(qp))2)].
The determinant is non-zero in the region where reality, positivity and uncertainty conditions are imposed on the state—that is, if one demands
q,p,(Δq)2,Δ(qp),(Δp)2∈R (Δp)2,(Δq)2≥0 (Δp)2(Δq)2−(Δ(qp))2≥ℏ24.
With these conditions in place, the sum of the terms inside the square bracket in the expression for the determinant is strictly positive, which means that the determinant itself is strictly negative.
There is one important check that one needs to perform. The introduction of , makes the surfaces a mixture of first and second class and one is required to adjust the Poisson structure of the functions parameterizing the surfaces through the use of the Dirac bracket. Before we can identify , , , , as the expectation values and moments of a physical canonical pair of operators, we need to verify that their Dirac brackets on are identical to the Poisson brackets one would obtain for the quantum variables associated with a single canonical pair. The bracket may be computed as follows
{f,g}Dirac:={f,g}−{f,χi}(Δ−1)ij{χj,g}. (11)
Using the fact that (and hence also ) is off-block-diagonal and that the physical variables have vanishing Poisson brackets with the gauge fixing conditions, one can easily verify that the second term in the above definition vanishes for the brackets between , , , , (as well as ), and therefore their Poisson structure is unchanged as required by our interpretation. These variables are the remaining physical quantities up to second order on the reduced quantum phase space.
To summarize, we impose the gauge-fixing conditions , , interpret , , , , as the physical expectation values and moments and as a result demand reality, positivity and quantum uncertainty. With all of these conditions taken together, , restrict the gauge freedom up to the orbits generated by (recall that generates no flow on ). This means that the time evolution is given by
CHam=μ1C1±.
Finally, we fix the remaining Lagrange multiplier by demanding —the last remaining gauge variable—to be the time parameter. That is, we demand that , which leaves us with
CHam=C1±=pt±E.
Taking the non-relativistic limit of we recover the results for a deparameterized free Newtonian particle. Specifically, if we formally take to be of order , it follows that in a semiclassical state is of order . We expand the expression for to the leading order in :
E= m√2(1+p2+(Δp)2m2)12(1+√1−4p2(Δp)2(p2+m2+(Δp)2)2)12 = m√2(1+p2+(Δp)22m2+O(δ2))(2+O(ℏδ2))12 = m+p2+(Δp)22m+O(δ2).
### 3.3 Comparison with the Klein-Gordon solution
The standard positive frequency solutions to the Klein-Gordon equation (see for example [18]) form a Hilbert space of momentum-space wave-functions square integrable with respect to the Lorentz-invariant measure:
H=L2(R,dk2ϵk),whereϵk=√k2+m2.
The system can be described through a canonical pair of observables, represented on as
p=kandq=iℏ(∂∂k+ϵk(∂∂k12ϵk)).
The time evolution is generated by the Hamiltonian . One can evaluate the evolution equations for the expectation values of the observables using Ehrenfest’s theorem
In our formalism, the right-hand side is equivalent to the quantum Poisson bracket between the expectation values, thus
ddt⟨O⟩ ={⟨O⟩,⟨H⟩}+∂⟨O⟩∂t={⟨O⟩,⟨(p2+m21)12⟩}+∂⟨O⟩∂t.
We recall that our procedure at order together with the gauge fixing conditions for the positive frequency solutions resulted in
ddt⟨O⟩={⟨O⟩,pt+E}={⟨O⟩,E}+∂⟨O⟩∂t.
In order to see whether the methods agree, we only need to compare and to order . To verify this explicitly we expand the operator in terms of its moments, assuming the expectation value to be taken in a semiclassical state:
⟨(p2+m21)12⟩= = √p2+m2(1+m2(Δp)22(p2+m2)2)+O(ℏ32).
For comparison, we expand in powers of , which we assume to be of order .
E =1√2√p2+m2(1+(Δp)2p2+m2+1+(m2−p2)(Δp)2(p2+m2)2+O((Δp)4))12 =√p2+m2√1+m2(Δp)2(p2+m2)2+O((Δp)4) =√p2+m2(1+m2(Δp)22(p2+m2)2)+O((Δp)4).
Thus, up to the terms of order the two results agree.
Unlike the exact Klein-Gordon solution, our approach avoids explicit reference to a representation. The action of the Lorentz group on our variables can be understood through its action on the algebra of observables. In particular, we assume that the pairs and transform as components of a contravariant and a covariant vector respectively. Looking at the truncated system of constraints (5) under a Lorentz transformation one finds that remains invariant, while the pairs and themselves transform as components of a contravariant and a covariant vector respectively, so that the whole truncated system of constraints is preserved.
### 3.4 Free massless particle
For a massless particle, the constraint operator takes the form
C=p2t−p2.
To second order in moments, the constraint functions produced remain as in equation (5), except for , which now reads
C=⟨C⟩=p2t−p2+(Δpt)2−(Δp)2=0.
The disappearance of a constant term from does not affect the Poisson algebra of the constraints, so that the table of Section 3.1 still applies. The solution to the constraints, however takes on a simpler form: following the same steps as previously and eliminating in a way compatible with the semiclassical approximation we obtain
(Δpt)2=(Δp)2.
Together with this implies
p2t=p2.
As we see, the classical constraint is satisfied exactly by the expectation values. We solve this via
pt=±|p|.
There are two related reasons for taking the absolute value of in the above solution. Firstly, to emphasize the sign of the energy. Secondly, to match the limit as is set to zero of the solution obtained in Section 3.1. The full solutions read
pt = ±|p| Δ(tpt) = ±p|p|Δ(tp)−iℏ2 (Δpt)2 = (Δp)2 Δ(ptq) = ±p|p|(Δ(qp)+iℏ2) Δ(ptp) = ±p|p|(Δp)2. (12)
The steps of Section 3.2 can be repeated exactly for the case with playing the role of . With the gauges fixed in an identical way, this results in evolution on , , , , generated by the constraint
CHam=pt±|p|. (13)
The implications will be discussed further in the conclusions.
## 4 Relativistic particle in a potential
In this section we consider the consequences of adding a potential term to the quantum constraint. We consider a quadratic time-independent potential in Section 4.1 followed by a homogeneous time-dependent potential in Section 4.2. The systems considered in this section have the same kinematical degrees of freedom as the free relativistic particle; however, the additional terms in the constraint element break Lorentz invariance. On the other hand, certain structural properties of the constraint element remain very similar to the free particle case, which makes extension of the calculations performed in Section 3 fairly simple. As we will see, the constraints are still straightforward to solve, but their Poisson algebra is only approximately closed and in the case of the time-dependent potential, the gauge analysis requires more subtlety. These examples show that the effective procedure used here is feasibly applicable to a wider range of models than the existing explicit constructions of a physical inner product. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9525781869888306, "perplexity": 529.1705792829716}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-21/segments/1652662530066.45/warc/CC-MAIN-20220519204127-20220519234127-00198.warc.gz"} |
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4.1: Functions, Limits, and Continuity
Difficulty Level: At Grade Created by: CK-12
Equations and Graphs
CONTENT
Students that are strong in algebra and motivated will appreciate a discussion of graphs/equations that consists essentially of examples like \begin{align*}y = x, y = x^2, y = x^n, x^2 + y^2 = R, xy = c, x^2 - y^2 = c, \frac{x^2}{a^z} + \frac{y^z}{b^z} = 1, y =\mathrm {Sin} (x),\end{align*} and so on. The plots could be shown and different characteristics of each could be discussed.
Students who are not as strong in algebra or are not as motivated may be better served by first reviewing rectangular coordinates, and then drawing some plots like a circle or a parabola. It can be pointed out that each point in any picture always has an \begin{align*}x\end{align*} and a \begin{align*}y\end{align*} coordinate. So we could prescribe how to draw a picture by listing the \begin{align*}x\end{align*} and \begin{align*}y\end{align*} values that should be darkened. An equation is just this, a description of which \begin{align*}x\end{align*} and \begin{align*}y\end{align*} values should contain ink and which should not.
PROCESS
The less experienced or motivated students should see the content of this lesson fine-tuned to their level. Equations and graphs may be introduced gradually by drawing a rectangular coordinate grid and going through Cartesian Coordinates as a means of locating points. They could be motivated by saying something like, suppose a person needs to a buried treasure. If the treasure is at the coordinates \begin{align*}(3,-7)\end{align*} then where is it? And so on.
Then, a simple equation like \begin{align*}y=x+2\end{align*} can be introduced by asking the question, “Which points \begin{align*}(x,y)\end{align*} on the graph I’ve drawn will make this equation true?” By taking some incorrect and some correct guesses, we should eventually arrive at the line:
One can then progress to more and more complicated equations like \begin{align*}y=x^2\end{align*} and \begin{align*}y=\sqrt{x-1}\end{align*}.
The more advanced or motivated student should be immersed in problem solving related to this lesson. For example, an advanced student might be asked to formulate an equation that describes some process, and then to plot this equation as a graph. Here are some possibilities:
Question 1:
You are given \begin{align*}\20\end{align*} each Monday morning as an allowance. This will allow you to spend \begin{align*}x\end{align*} dollars each weekday for lunch and \begin{align*}y\end{align*} dollars over the weekend so that you use it all up by Monday. Find an equation involving \begin{align*}x\end{align*} and \begin{align*}y\end{align*} to describe this and then plot the possible values of \begin{align*}x\end{align*} and \begin{align*}y\end{align*} that solve this equation.
\begin{align*}20-5x-y=0\end{align*} or equivalently \begin{align*}y=20-5x\end{align*}. And the plot should look like:
Question 2:
A right triangle with height \begin{align*}x\end{align*} and width \begin{align*}y\end{align*} has area equal to \begin{align*}100\end{align*}. Find an equation to describe the possible values of \begin{align*}x\end{align*} and \begin{align*}y\end{align*} and plot the values that solve it.
Answer 2: \begin{align*}\frac{xy}{2} = 100\end{align*} or equivalently \begin{align*}y = \frac{200}{x}\end{align*}. And the plot should look like:
Question 3:
If y is the area of a square and \begin{align*}x\end{align*} is the perimeter, what is an equation relating \begin{align*}y\end{align*} and \begin{align*}x\end{align*} and a plot of the values that solves the equation.
Answer 3: \begin{align*}y = \left (\frac{x}{4} \right )^2\end{align*} or equivalently \begin{align*}y = \frac{1}{16} x^2\end{align*}. And the plot should look like:
PRODUCTS
There are a variety of different ways in which a student can demonstrate mastery of equations and graphs. The most straightforward are simply drawing graphs for a variety of different equations or looking at graphs and recognizing the corresponding equations. This could be done, for example with a matching game where graphs are on the right and equations are on the left and the object is to decide which goes with which.
Another possibility is to assign a complicated equation to each student like \begin{align*}y = e^{\mathrm {Sin}(x^2)}\end{align*} or may be \begin{align*}y = \mathrm {Cos} \left (\frac{1}{x} \right )\end{align*} and ask them to graph their equation carefully with a description of the properties, like what happens as \begin{align*}x\end{align*} becomes very large or very small, or negative. Then each student could give a brief presentation of his/her equation on the board in which s/he would draw the graph and discuss why the equation implies certain properties of the graph.
Relations and Functions
CONTENT
The concept of a function has a very natural splitting into two levels. The content for students who are very motivated and enjoy math could begin with the most general description of a function in terms of sets. A function \begin{align*}f\end{align*} in its most abstract sense is just a set of ordered pairs of elements from two sets \begin{align*}A\end{align*} and \begin{align*}B\end{align*}. That is, \begin{align*}f=\left \{(a,b) | a \in A,b \in B \right \}\end{align*}. The set \begin{align*}A\end{align*} is called the domain of \begin{align*}f\end{align*} and the set \begin{align*}B\end{align*} is called the range. In order to think of a function as a machine taking elements of \begin{align*}A\end{align*} and producing elements of \begin{align*}B\end{align*}, we should require that each \begin{align*} a \in A\end{align*} belongs to only pair in \begin{align*}f\end{align*}. That way, each \begin{align*}a\end{align*} is sent to only one element of \begin{align*}B\end{align*}.
Then this concept could be specified to the particular nature of single-variable calculus. In this subject functions map numbers to numbers, and the domain and range are just open or closed subsets of the real number line \begin{align*}\mathbb{R}=(- \infty , \infty)\end{align*}.
For the less motivated or experienced student, this content should be made more geometric by focusing on the vertical-line test for functions. A graph is the graph of a function if any vertical line intersects the curve only once (or not at all). The domain of a function is the shadow cast upon the \begin{align*}x-\end{align*}axis by a light from above and the range is the shadow cast on the \begin{align*}y-\end{align*}axis by a light from the right.
PROCESS
The learning process here could take many different routes. It is a good idea to begin with students’ intuitions, and so for a first activity it would be good to discuss what an idealized machine does. For example, consider the following function:
Suppose we pick a thesaurus up, and use it as a machine for turning words into other words. Given some word like, say, “happy”, we look up the word and choose the first synonym that appears. If we were using thesaurus.com then we would have in this case that: \begin{align*}f\end{align*} (happy)=blessed.
Then there are a variety of function characteristics that can be seen in this example. We note that not all words appear in a thesaurus, so the domain is limited and so is the range. In fact, the domain and range are probably just about the same subsets of the English language.
Furthermore, we see that using just one thesaurus we always get just one result from a given word. It is not possible for \begin{align*}f\end{align*}(happy)=blessed and simultaneously to have that \begin{align*}f\end{align*}(happy)=content. This means that for a given input, we will have one fixed output. On the other hand, we might get the result “blessed” for a different input as well. This means that if \begin{align*}f(a)=c\end{align*} the we may also have that \begin{align*}f(b)=c\end{align*} as well.
Another fun project is for students to think of as many sets (or categories) as possible and write these on the board, like:
{brands of cereal},{famous people},{colors}, {songs},{movies},{whole numbers} and so on. Then the class could split into partners and each duo could be tasked with determining a function from one of these sets to another. The pair should carefully describe the domain and range, and why it is that this is indeed a function. In other words, why is it that no object from one set is mapped to more than one from another. As an example from the sets above, consider {brands of cereal} and {famous people}. We could have a function that takes a famous person and maps him/her to his/her favorite brand of cereal. In order to be sure this is a function we must include only famous people who have a single favorite brand. If they have more than one, that would violate our rule of functions. Furthermore, famous people with no favorite brand of cereal do not belong to the domain and cereals that nobody likes would not be in the range.
This would be a good subject to learn using small groups as well. The class could be split into groups of three and each group could be given an equation like \begin{align*}y^2+x^2=4\end{align*} or like \begin{align*}y = \mathrm {Sin}(x)\end{align*} and the group would first graph the equation. Then they would have to determine if it is a function and then figure out the domain and range if it is a function. This could be presented to the class afterwards. Each group should be closely monitored to make sure that each member is participating and in order to be sure of this fact, it would be advisable to have members each produce paperwork describing the qualities of the group’s equation.
PRODUCTS
There are many possible ways to test a student’s knowledge of this material. The most basic is to provide a series of graphs and ask which are graphs of functions, and a series of equations and ask which are equations representing functions with input \begin{align*}x\end{align*} and output \begin{align*}y\end{align*}. The follow-up, of course, asks in the case that the equation or graph is not a function then what \begin{align*}x\end{align*} value is mapped to more than one \begin{align*}y\end{align*} and in the case that it is a function, what are the domain and range.
The nice thing about these problems is that they are simple to come up with in large quantity, can be tailored to the level of any student, and will introduce important equations that will be used later. However, for the student that is very difficult to motivate it may be better to use examples from everyday life. For example, consider the “Wal-Mart Function” which takes a product and returns the price. Why is this a function? Or perhaps, what do we have to specify in order to make sure that it is a function? What is the domain and what is the range? A great variety of different functions like this can be considered, and thinking of more everyday things may motivate students that do not typically enjoy math. Here are some more examples:
1. Wal-Mart Function: \begin{align*}\mathrm{products} \rightarrow \mathrm{price}\end{align*} For example: \begin{align*}f(\mathrm{dollhouse})= \149.99\end{align*}
2. Mother’s Name Function: \begin{align*}\mathrm{people} \rightarrow \mathrm{mother' s name}\end{align*}
3. Inverse Mother’s Name Function: \begin{align*}\mathrm{mother's name} \rightarrow \mathrm{person}\end{align*} (Is this a function??)
4. Mountain Height Function: \begin{align*}\mathrm{mountain name} \rightarrow \mathrm{height above sea level}\end{align*}
Models and Data
CONTENT
The content in this lesson begins with a simple data set containing a list of \begin{align*}x-\end{align*}values and the corresponding \begin{align*}y-\end{align*}values like:
\begin{align*}& x && y \\ & 0 && 0 \\ & 1 && 10 \\ & 2 && 30 \\ & 3 && 5 \\ & 4 && -7 \\ & 5 && -205 \\ & 6 && 3.141\end{align*}
This content cannot be differentiated in any way although it should be said that a more basic approach for the less-experienced should be more concrete. The numbers should be given explicitly and should represent something concrete like the profit for a given year. A more advanced or motivated student might appreciate abstraction where the data is given as simply a set of n number pairs: \begin{align*}\left \{(x_i,y_i)|i=1,2, \ldots ,n \right \}\end{align*}.
The functions to which one seeks to fit this data have progressive levels of difficulty. And this gives an opportunity for differentiation. A more basic student may be taught only to fit data only to functions of the form \begin{align*}y = a + bx\end{align*} or \begin{align*}y = a + bx + cx^2\end{align*}. More generally, the most basic fits correspond to polynomial fits of the form: \begin{align*}y = a_0 + a_1 x + a_2 x^2 + a_3 x^3 + \ldots\end{align*}. It turns out to be the case that any data set containing \begin{align*}n\end{align*} points can be exactly fit to a polynomial with highest power \begin{align*}n-1\end{align*}.
The more motivated or experienced student can also try fits with trigonometric functions of the form \begin{align*}y = a \mathrm {Sin}(bx+c)\end{align*} or with exponential functions of the form \begin{align*}y = a \ b^{cx} + d\end{align*}. It can be pointed out that these are actually like fitting the data to an infinitely long polynomial. If this piques interest then students can be assured that they will learn more about this towards the end of their calculus class when infinite series are discussed.
PROCESS
The process of fitting data presented in this chapter leaves little room for differentiation since it is done entirely by calculator. A fun homework project for students may be to find some data sets on the internet and then do some fitting.
A fun project would be to predict the temperature for the next \begin{align*}2\end{align*} or \begin{align*}3\end{align*} days by using temperature data from the past and a reasonable fit. The students could look up past values, create a fit, and then project the fit beyond the present to see what will happen. This could even be done with some past date. The teacher could bring in temperature data for \begin{align*}100\end{align*} consecutive days in \begin{align*}1984\end{align*} and have students fit this to a function. There could be a competition to see which student is best able to predict the future.
This could also be done with stock prices, something that may be more exciting since it involves money. The teacher could present the price of a certain stock for the past \begin{align*}100\end{align*} trading days and students could be divided into groups. Each group could be asked to try a different kind of fit for this data, and then use this to predict what will happen over the next ten days. Alternatively, students could try various plots and decide which to believe. There could even be a virtual stock market where students are each student virtually purchases \begin{align*}10\end{align*} stocks and must decide based upon their fits whether to buy or sell more stock from classmates.
PRODUCTS
As mentioned in the above, it would be a fun project to have students use data to predict the future of a stock price or the weather. This it seems would be the most engaging end product for all of the students to produce since it is so tangible.
On the other hand, there is always the more abstract option which would be to provide lists of data and ask for the plot variables \begin{align*}a,b,c\end{align*},etc. that best fit this to a certain form. The student could be asked how good this plot is by using numbers given by most calculators like \begin{align*}R-\end{align*}values.
The Calculus
CONTENT
This material can be presented to the entire class by focusing carefully on the geometric nature of every idea. Previously, the students have understood how to think about the steepness of a straight line through the points \begin{align*}(x_1,y_1 )\end{align*} and \begin{align*}(x_2,y_2)\end{align*}. This is just the slope \begin{align*}m=\frac{y_2-y_1}{x_2-x_1}\end{align*}.
However, if the graph is not straight but curved between these points then what does the number \begin{align*}m=\frac{y_2-y_1}{x_2-x_1}\end{align*} represent geometrically. It isn’t the slope or steepness at \begin{align*}(x_1,y_1)\end{align*} or at \begin{align*}(x_2,y_2)\end{align*}. It’s sort of like the average steepness between these two points. So how would we find the steepness at just one point? Well, by drawing a picture like this:
it should become clear that the slope of the red lines gets closer and closer to slope at p as we move the two points nearer and nearer.
The line whose slope we are examining with each guess always passes through two points and is called a secant. But with each guess the secant line becomes closer and closer to a line which passes through just one point. This is the tangent line, and if we zoom way in on the point \begin{align*}p\end{align*} then the curve itself and the tangent will be indistinguishable. That is why we often refer to the tangent as a linear approximation to the curve at \begin{align*}p\end{align*}.
Connecting this idea of tangents with areas in a casual or qualitative way is challenging. However, the geometric connection can described if we let \begin{align*}f(x)\end{align*} be any function and \begin{align*}F(z)\end{align*} be the function that gives the area under \begin{align*}f(x)\end{align*} between \begin{align*}x=0\end{align*} and \begin{align*}x=z\end{align*}:
Then \begin{align*}F(z)\end{align*} is not changing only when \begin{align*}f(z)=0\end{align*}, and is increasing at a rate that is proportional to \begin{align*}f(z)\end{align*}. That is, the bigger \begin{align*}f(z)\end{align*} is at any point, the faster the area is increasing as we move to the right (that is, as \begin{align*}z\end{align*} increases).
Now, the rate of change for a function like \begin{align*}F(z)\end{align*} at a point z is its steepness or slope at the point \begin{align*}z\end{align*}. So we see that the rate of change for the area function \begin{align*}F(z)\end{align*} is equal to the function whose area it is describing \begin{align*}f(z)\end{align*}. This is the content of the Fundamental Theorem of Calculus.
PROCESS
Getting students to understand these ideas can be tricky. There are a number of approaches that could be tried. The first would be to draw a big Cartesian coordinate system on the board with a big blown up version of \begin{align*}y=x^2\end{align*}. Then select two points like \begin{align*}(1,1)\end{align*} and \begin{align*}(4,16)\end{align*} and have a student come draw the line that connects these points. Then have the class calculate this line’s slope. Next do the same for the points \begin{align*}(1,1)\end{align*} and \begin{align*}(3,9)\end{align*} and then for \begin{align*}(1,1)\end{align*} and \begin{align*}(2,4)\end{align*} and then maybe for \begin{align*}(1,1)\end{align*} and \begin{align*}(1.414,2)\end{align*}. Point out how the lines that were drawn are getting closer and closer to the tangent line, and that the slopes are getting closer and closer to the number \begin{align*}2\end{align*}.
Another great technique involves a fun little riddle. The average speed for a trip is the total distance traveled divided by the total time. This is like the secant line for the position plot. Suppose that a racecar is planning two laps around a \begin{align*}2 \;\mathrm{mile}\end{align*} track. If averages \begin{align*}60\frac{\mathrm{mi}}{\mathrm{hr}}\end{align*} over the first lap, how fast must it travel over the second lap to average \begin{align*}180 \frac{\mathrm{mi}}{\mathrm{hr}}\end{align*} over both miles combined?
Now, speed is distance over time so we want to think of distance as the \begin{align*}y-\end{align*}variable and time as the \begin{align*}x-\end{align*}variable. At an average speed of \begin{align*}60\end{align*}, the first mile will take one minute. So we know the car’s plot over the first mile will look something like:
where we actually don’t know the shape of the curve between \begin{align*}(0,0)\end{align*} and \begin{align*}(1,1)\end{align*}. All we know is that it does make it to this point. In order to average \begin{align*}120 \;\mathrm{mi/hr}\end{align*} overall, the car would have to travel two miles in \begin{align*}1 \;\mathrm{minute}\end{align*}. So the curve would have to pass through the point indicated here as well:
However, there is clearly no way to continue the curve in the first plot through the point in the second plot without going vertically at some point. This would mean the steepness would be undefined, or infinite, and this is not a valid speed. Therefore it is impossible to average \begin{align*}180 \;\mathrm{mi/hr}\end{align*} overall after averaging \begin{align*}60 \;\mathrm{mi/hr}\end{align*} for a mile. The minute needed has already been used up.
PRODUCTS
This material is difficult to test since it is largely qualitative. However, questions asking for a written or verbal description of the derivative or tangent line would work. Students could be divided into small groups and asked to approximate some quantity like the slope of the tangent line to \begin{align*}y=3x^2-4x+5\end{align*} at \begin{align*}x=2\end{align*} or the area under \begin{align*}y=3x^2-4x+5\end{align*} between \begin{align*}x=0\end{align*} and \begin{align*}x=3\end{align*}. They should accomplish each of these tasks using successive approximations as secant lines or Riemann rectangles respectively.
Finding Limits
CONTENT
Note: It is strongly encouraged that teachers use the variable \begin{align*}h\end{align*} as the independent variable in this lesson instead of \begin{align*}x\end{align*} as the author of the text has used. This will significantly reduce the burden on students when both \begin{align*}x\end{align*} and \begin{align*}h\end{align*} are involved and limits are being taken for \begin{align*}h\end{align*} only.
In order to make this material accessible to anyone, the introduction should be as intuitive as possible. For example, in the last lesson we described that finding the slope at a point or the area under a curve involves a process of taking better and better estimates. So the question is: What do we do if instead of having an exact number, all we have is a bunch of progressive estimates for it?
Recall that in the last lesson we were estimating the slope of \begin{align*}y=x^2\end{align*} at \begin{align*}x=1\end{align*}, and perhaps if we had continued this process we’d get a series of estimates that look like: \begin{align*}\left \{6.92,4.23,2.1,2.006,2.00007,\ldots \right \}\end{align*}. We may even be able to write these as a function like \begin{align*}f(h)= \frac{1}{h} ((1+h)^2-1)\end{align*} where these are just successive values as we let \begin{align*}h\end{align*} get closer and closer to zero. Now, while it could be clear that the estimates are getting closer and closer to the number \begin{align*}2\end{align*}, they also never actually get there. And we can’t very well just plug \begin{align*}h=0\end{align*} into the function since there is an \begin{align*}h\end{align*} in the denominator and we don’t know how to divide by \begin{align*}h\end{align*}.
For this reason we must define a concept of limit so that we can concretely say that
\begin{align*}\lim_{h \to 0} \frac{1}{h} ((1 +h)^2 - 1) = 2\end{align*}
This is no simple task since, as we said, \begin{align*}h\end{align*} cannot just be plugged in directly. Despite this, we can easily see by using our calculator or a piece of paper that choosing smaller and smaller values of \begin{align*}h\end{align*} gives results that are closer and closer to \begin{align*}2\end{align*}. So maybe we can have some way of saying mathematically that the values get closer and closer to \begin{align*}2\end{align*} as \begin{align*}h\end{align*} gets smaller.
This is the content of the formal definition for a limit’s existence. We first need to specify the phrase closer and closer. In order to make this concrete, we say that for any distance you can think of, no matter how small, we will eventually be even closer than that! Furthermore, we will stay that close or closer for better and better approximations.
The statement in the book for the result that:
\begin{align*}\lim_{h \to 0} \frac{1}{h} ((1 +h)^2 - 1) = 2\end{align*}
can be translated as follows: Pick the smallest positive distance you can think of. Then I can find a distance so that if \begin{align*}h\end{align*} is less than that distance from \begin{align*}0, \frac{1}{h} ((1+h)^2-1)\end{align*} will be less than your distance from \begin{align*}2\end{align*}. That is, no matter how close to \begin{align*}2\end{align*} you want me to get I can find \begin{align*}h-\end{align*}values that will get the function within that distance.
PROCESS
This is really the first very conceptually challenging concept that most students learn in all of math. And indeed, many students will simply leave the definition of a limit behind without fully getting it. It may even be this concept that plays a large role in whether a student will like calculus or hate it. So the teacher’s responsibility to convey this idea intuitively and clearly is a great one.
The only real way for students to get this definition is by trying to formulate it themselves. Begin with the simple function:
\begin{align*}f(h) = \frac{h^2 - 1}{h - 1}\end{align*}
Now, clearly \begin{align*}f(1)\end{align*} is not defined since there’s a zero in the denominator. On the other hand you can probably see that \begin{align*}f(h)\end{align*} can be simplified as \begin{align*}f(h)=h+1\end{align*} but this is only valid when \begin{align*}h\end{align*} is not equal to \begin{align*}1\end{align*}. Then pose the question: How could we say that as \begin{align*}h\end{align*} gets closer and closer to \begin{align*}1, f(h)\end{align*} gets closer and closer to \begin{align*}2\end{align*}?
The class should be divided into small groups where each group ideally contains at least one member who is strongly motivated mathematically. This will help motivate the other members. Then, the group should come up with a precise description of the behavior that \begin{align*}f(h)\end{align*} is getting closer to \begin{align*}2\end{align*} as \begin{align*}h\end{align*} is getting closer to \begin{align*}1\end{align*}. The group will have succeeded if the teacher:
1. Can show that according to the group’s precise description, \begin{align*}f(h)\end{align*} is getting closer to \begin{align*}2\end{align*} as \begin{align*}h\end{align*} gets closer to \begin{align*}1\end{align*}
2. \begin{align*}f(h)\end{align*} is NOT getting closer to something other than \begin{align*}2\end{align*} as \begin{align*}h\end{align*} gets closer to \begin{align*}1\end{align*}
3. \begin{align*}f(h)\end{align*} is NOT getting closer to \begin{align*}2\end{align*} as \begin{align*}h\end{align*} gets closer to something other than \begin{align*}1\end{align*}
Clearly, the teacher’s job here is quite difficult. S/he must move from group to group assisting with the thought process and gently nudging the group towards a definition like the one in the book. If the students are delicately allowed to struggle with these ideas, and to talk them over carefully, then the definition will become clear.
PRODUCTS
Clearly all of the students will have difficulty grasping the definition of a limit’s existence. It is therefore recommended that for students that are having significant difficulty, problems are given which only involve steps towards understanding limits. For example, they could numerically find limits of various complicated with canceling factors like:
\begin{align*}\lim_{h \to 1} \frac{5 - 4h - h^2 - 3h^3 + 3h^4 - h^5 + h^6}{-24 + 24h + h^2 + h^4 + 3h^7 - 3h^8}\end{align*}
or the famous example:
\begin{align*}\lim_{h \to 0} \frac{\text {Sin}(x)}{x}\end{align*}
Alternatively, these students could be asked leading questions about a simpler function like:
1. How small must we choose \begin{align*}h\end{align*} so that \begin{align*}f(h) = \frac{h^2 -1}{h - 1}\end{align*} is between \begin{align*}1.9\end{align*} and \begin{align*}2.1\end{align*}
2. How small must we choose \begin{align*}h\end{align*} so that \begin{align*}f(h) = \frac{h^2 -1}{h - 1}\end{align*} is between \begin{align*}1.99\end{align*} and \begin{align*}2.01\end{align*}
3. How small must we choose \begin{align*}h\end{align*} so that \begin{align*}f(h) = \frac{h^2 -1}{h - 1}\end{align*} is between \begin{align*}1.999\end{align*} and \begin{align*}2.001\end{align*}
4. How small must we choose \begin{align*}h\end{align*} so that \begin{align*}f(h) = \frac{h^2 -1}{h - 1}\end{align*} is between \begin{align*}2 - \in\end{align*} and \begin{align*}2 + \in\end{align*}
The more advanced student could be challenged directly to find deleted neighborhoods of the limit point \begin{align*}a\end{align*} (for \begin{align*}x \rightarrow a\end{align*}) which correspond to given neighborhood \begin{align*}D\end{align*} of a limit \begin{align*}L\end{align*}. That is, for example:
1. Show directly using the definition of a limit that \begin{align*}\lim_{h \to 0} \frac{h^2 - 1}{h - 1} = 2\end{align*}
2. Show directly using the definition of a limit that \begin{align*}\lim_{h \to 1} \frac{h^2 - 4h + 3}{h^2 + h - 2} = - \frac{2}{3}\end{align*}
Evaluating Limits
CONTENT
It is a good exercise with the definition of a limit to prove some of the assertions in this chapter. For example, the squeeze theorem can be proven by noting that since by assumption \begin{align*}\lim_{x \to a} f(x) = \lim_{x \to a} h(x) = L\end{align*} then any interval containing \begin{align*}L\end{align*} will have corresponding intervals surrounding \begin{align*}a\end{align*} such that \begin{align*}f\end{align*} and \begin{align*}h\end{align*} give values inside the interval containing \begin{align*}L\end{align*}. So if we choose the overlap (or intersection) of these intervals, then any \begin{align*}x\end{align*} in this overlap will also give values from both \begin{align*}f\end{align*} and \begin{align*}h\end{align*} inside the interval around \begin{align*}L\end{align*}. But then since by assumption \begin{align*}f(x) \le g(x) \le h(x)\end{align*} we must have that \begin{align*}g\end{align*} also gives values inside this interval.
The other results will involve a lot of notation as well and students are likely to lose the forest for the trees if teachers are not careful. The salient point of all these properties is that basically students can do exactly what they think they can do, as long as everything involved has a limit. If \begin{align*}f\end{align*} and \begin{align*}g\end{align*} have limits then \begin{align*}f+g\end{align*} has a limit and it is equal to the sum of the limits for \begin{align*}f\end{align*} and \begin{align*}g\end{align*}. Most students would be guided to suspect this and that intuition should not be shunned.
PROCESS
It is on utmost importance that students have to ability to approach limits mentally. That is, consider the problem of finding the following limit:
\begin{align*}\lim_{n \to \infty} 3 + \sqrt{\frac{1}{n}}\end{align*}
Of course, one could use the sum rule and then the constant rule and then the power rule. But it is much more powerful to simply be able to see that for large values of \begin{align*}n\end{align*}, the second term gets smaller and smaller while the first term is unchanged. So the limit is clearly \begin{align*}3\end{align*}.
The best process for learning that is accessible to all should be aimed at building this intuition. This begins with very simple limits like the one above, or other sums of basic equations. Have the students mentally approach the limiting value and think about what will happen. Perhaps this could be done as a game. Have the students put all of their materials away (or under their desks). This way they have nothing more than their minds to rely upon. Then split the class into two more or less equal teams, and have them compete to see which team can obtain a limit faster. Tell them that they are not to speak, but to raise their hand and that you will call on the first hand you see. However, once you’ve gotten a question right for your team you are not allowed to answer again until round two. Problems can be as simple as \begin{align*}\lim_{h \to \infty} \frac{1}{h}\end{align*} or \begin{align*}\lim_{h \to 0} \frac{h}{h + 1}\end{align*}. This way students will slowly be able to do these in their heads and will become more comfortable in general with limits.
The next step is to familiarize students with more complicated radicals and provide some intuition for these. For example, with a complicated limit like:
\begin{align*}\lim_{h \to \infty} \frac{4h^7 + 3h^2 - 2h + 9}{2h^7 - 6}\end{align*}
the intuition that students have just developed may falter. This is because both the numerator and the denominator seem to get large for large \begin{align*}h\end{align*} and \begin{align*}\frac{\infty}{\infty}\end{align*} is not defined. So instead they can do a little trick before employing intuition, and that is to get rid of the highest powers in \begin{align*}h\end{align*} by multiplying numerator and denominator by \begin{align*}\frac{1}{h^7}\end{align*}. That is, we note that for \begin{align*}h\end{align*} not equal to zero we have:
\begin{align*}\left (\frac{4h^7 + 3h^2 - 2h + 9}{2h^7 - 6} \right ) \left (\frac{\frac{1}{h^7}}{\frac{1}{h^7}} \right ) = \frac{4 + \frac{3}{h^5} - \frac{2}{h^6} + \frac{9}{h^7}}{2 - \frac{6}{h^7}}\end{align*}
and we can then easily use intuition on this to see that for larger and larger values of \begin{align*}h\end{align*}, all of the fractions become tiny so that:
\begin{align*}\lim_{h \to \infty} \frac{4h^7 + 3h^2 - 2h + 9}{2h^7 - 6} = \lim_{h \to \infty} \frac{4 + \frac{3}{h^5} - \frac{2}{h^6} + \frac{9}{h^7}}{2 - \frac{6}{h^7}} = \frac{4}{2} = \underline{2}\end{align*} Basically, it can be explained that limits to infinity are battles between the numerator and the denominator. If the numerator wins because it has a higher power of \begin{align*}h\end{align*}, then the fraction goes to infinity. If the denominator wins because it has a higher power of \begin{align*}h\end{align*}, then the fraction becomes tiny. And if the numerator and denominator have the same highest power, then all the other terms become tiny at big values of \begin{align*}h\end{align*} and it is only this highest power term that matters.
In order to evaluate limits as \begin{align*}h\end{align*} goes to \begin{align*}0\end{align*}, we can apply the same strategies by simply taking a new limit where we replace the variable \begin{align*}h\end{align*} by \begin{align*}\frac{1}{h}\end{align*} and take the limit as \begin{align*}h\end{align*} goes to infinity. Otherwise we can see that the opposite thinking works. Instead of looking at the highest powers in the numerator and the denominator, we look to the lowest powers. These are the ones which dominate as \begin{align*}h\end{align*} becomes small. This kind of intuition will be indispensible as the math becomes more advanced.
PRODUCTS
Testing this material is very straightforward, since students can simply be asked to find a series of limits with varying difficulty. However, it is a good idea to make assignments as predictive as possible. So for example, the following questions are very good ones:
1. Find the limits:
\begin{align*}& \lim_{h \to 0} \frac{(x+h) - x}{h} \\ & \lim_{h \to 0} \frac{(x+h)^2 - x ^ 2}{h} \\ & \lim_{h \to 0} \frac{(x+h)^3 - x^3}{h} \\ & \lim_{h \to 0} \frac{(x+h)^4 - x^4}{h}\end{align*}
2. Can you find a way to calculate or guess at the following limits based upon your experience above:
\begin{align*}& \lim_{h \to 0} \frac{(x+h)^{10} - x^{10}}{h} \\ & \lim_{h \to 0} \frac{(x+h)^n - x^n}{h} \text{where}\ n \ \text{is any integer} > 0\end{align*}
Continuity
CONTENT
The definition of continuity given in this lesson is clunky since the “conditions” are not independent. In other words, the third condition that:
\begin{align*}\lim_{x \to a} f(x) = f(a)\end{align*}
depends upon the other two being satisfied. It would be better simply to define a function as continuous at a point \begin{align*}x=a\end{align*} of its domain if the equation above is satisfied. If the limit does not exist then the equation cannot be satisfied.
This is a very intuitive definition, but the first example given in the text does not illustrate why. The reason the function \begin{align*}f(x) = \frac{(x+1)}{(x^2-1)}\end{align*} fails to be continuous at \begin{align*}x=-1\end{align*} is because \begin{align*}-1\end{align*} is not even part of the domain. That is to say, the function \begin{align*}f\end{align*} is not defined at \begin{align*}x=-1\end{align*} and therefore cannot be continuous there. This is a technicality though, and doesn’t really illustrate how the definition works.
The second example given does a much better job, and this is the content which should be used to illustrate the definition. This example uses the function:
\begin{align*}f (x) = \begin{cases} x & x \neq 1 \\ 3 & x = 1\end{cases}\end{align*}
which has the desirable property at \begin{align*}x=1\end{align*} that \begin{align*}f(x)\end{align*} approaches \begin{align*}1\end{align*} whereas \begin{align*}f(1)=3\end{align*}. This is what the definition of continuity has in mind, a jump in \begin{align*}f\end{align*} at some particular value of \begin{align*}x\end{align*}. So basically \begin{align*}f\end{align*} can fail to be continuous at a point \begin{align*}a\end{align*} because the function is not defined at \begin{align*}a\end{align*} or it jumps suddenly at \begin{align*}a\end{align*}. That’s it. The concept is not complicated, although putting the math into words requires a little thinking. PROCESS
Some students may respond better to pictures, and some may respond better to formulas. Testing for continuity with a picture means plotting a function near the point in question. Then, if the line ends at the point in question (that is, if you would need to lift your pencil in order to draw the plot there) the function is discontinuous. This works for functions which fail to be continuous for either reason: a jump or a gap in domain. Learning from the formulas, on the other hand, means calculating limits of functions directly using rules from the earlier lesson.
A nice lesson plan would point out that occasionally we can “fix” discontinuities by simply redefining the function’s value at a single point. If this is the case, then the discontinuity is said to be removable. The piecewise function given above is a simple example since we have that:
\begin{align*}\lim_{x \to 1^+} f(x) = \lim_{x \to 1^-} f(x) = 1\end{align*}
So we can simply redefine \begin{align*}f(1)=1\end{align*} and the new function will be continuous. A similar example is the more complicated function \begin{align*}f(x)=\frac{\mathrm {Sin}(x)}{x}\end{align*}. This function is discontinuous at \begin{align*}x=0\end{align*} since it fails to be defined there, however we could make a new function from it that is continuous by setting its value at \begin{align*}0\end{align*} equal to the limit \begin{align*}\lim_{x \to 0} f(x) = 1\end{align*}. However, in this case the discontinuity is not said to be removable since the point \begin{align*}0\end{align*} was not even in the original function’s domain.
PRODUCTS
Tricky problems can be formulated to test students’ understanding of continuity. Questions which contain follow-ups asking students to describe why a function is discontinuous or continuous are good ones. Furthermore, students might be asked if a particular discontinuity is removable or can be otherwise “fixed”.
Infinite Limits
CONTENT
The concept of infinity can be challenging to students at first. However, the concept of infinity is actually dual to the concept of zero. This is because the following are true when the corresponding limits exist:
\begin{align*}\lim_{x \to 0+} f(x) & = \lim_{x \to + \infty} f \left (\frac{1}{x} \right ) \\ \lim_{x \to 0^-} f(x) & = \lim_{x \to - \infty} f \left (\frac{1}{x} \right )\end{align*}
We have similar rules when the limits are divergent but under these circumstances the direction in which limits are taken can make things a little messy. Suffice it to say that infinity can be understood by letting the denominator of a fraction get very small.
This is actually the introduction to the topic of compactifications for the real line, which gives a nice geometric means of understanding infinite limits. The entire real line can be wrapped around a circle so that zero matches up with the very bottom of the circle and the two ends fold up on either side of the circle. We can compress these down so that they just nearly reach the top of the circle, and then call the top of the circle infinity or \begin{align*}\infty\end{align*}. Then approaching infinity just means moving along the circle towards the top and watching what happens with the target point.
PROCESS
Students will learn this concept with practice. The best way to encourage practice, though, may be through a process similar to the one we used for the section on equations. Students can be divided into groups of two or three and given a complicated function. They should try plotting the function and then examine all limits of interest including any points of discontinuity as well as \begin{align*}+ \infty\end{align*}, and \begin{align*}- \infty\end{align*}. Then they can present their function to the class with the plot and a discussion of each limit. Ideally the teacher should assure each group is progressing and try to encourage participation by each group member.
PRODUCTS
Students can demonstrate their mastery of this material by trying a number of
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http://clay6.com/qa/14772/assertion-a-k-rb-and-cs-form-superoxides-reason-r-the-stability-of-the-supe | Browse Questions
# Assertion (A) : K,Rb and Cs form superoxides. Reason (R): The stability of the superoxides increase from 'K' to 'Cs' due to decrease in lattice energy.
(1) Both (A) and (R) are true and (R) is the correct explanation of (A)
(2) Both (A) and (R) are true and (R) is not the correct explanation of (A)
(3) (A) is true but (R) is not true
(4) (A) is not true but (R) is true | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8444040417671204, "perplexity": 3112.6538569942068}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-13/segments/1490218188550.58/warc/CC-MAIN-20170322212948-00212-ip-10-233-31-227.ec2.internal.warc.gz"} |
http://creationwiki.org/Dark_matter | The Creation Wiki is made available by the NW Creation Network
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# Dark matter
Dark matter, in astronomy, is any hypothetical matter that is not directly detectable but which astronomers infer when the actual mass of any observed celestial object is not sufficient to account for an observed gravitational effect. It is one of two concepts (the other is dark energy) that evolutionistic astronomers invoke to account for observations that old-universe cosmologies, including the big bang, cannot explain. Recently, creationist John Hartnett has suggested a new cosmology, and a new physics, that render this concept unnecessary.
## The first dark matter
Main Article: Vulcan
The first recorded instance of the invocation of anything similar to dark matter was the hypothesis of a planet named Vulcan in the mid-1850s. This planet was supposed to be inside the orbit of Mercury and yet was never directly observed from Earth, for reasons that no astronomer ever explained. Astronomers inferred the existence of this planet because Mercury precessed in its orbit around the Sun by 43 arc-seconds per century faster than expected by Newtonian physics. Many apparently observed transits of unidentified objects across the sun were thought to be this undiscovered planet.
Then in 1915, Albert Einstein solved the problem. He showed that Mercury, at perihelion, passes close enough to the Sun for General Relativity to require a second-order correction. He published the correction and accounted exactly for the precession in the orbit of Mercury, without the need for any planet, asteroid belt, or other object or objects inside that orbit.[1]
## The current problem
The current problem involving a mass deficit in astronomical observations has been known since the 1930's, when astronomers first found serious differences between the masses they inferred by examining orbital speeds and the masses they inferred by measuring stellar, galactic, and other visual magnitudes. The classic gravitational equation, derived from the theory of gravity of Sir Isaac Newton, gives the total dynamical mass in any system that is inside the orbit of any given body (for example, a particular star in its galaxy):
$M={\frac {v^{{2}}R}{G}}$
where R is the distance of the body from the barycenter, v is the orbital speed of that body, and G is the gravitational constant.
The luminous mass of any galaxy or other object is the mass that corresponds to the measured light from the object.
Jan Oort first determined that the total mass of our galaxy was insufficient by a factor of at least two to account for the galaxy's rotational speed.[2] The swiss astronomer Fritz Zwicky is also credited with the discovery of the discrepancy between dynamical and luminous mass, in 1933. Zwicky examined the Coma supercluster, and found that its dynamical mass exceeded the luminous mass by a factor of ten.[3][4][5]
Image of galactic cluster with ring of alleged dark matter around it
Since that time, astronomers have assumed that some form of matter, which gives off no measurable radiation, is nevertheless present in various galaxies and galactic clusters that clearly spin faster than their measured luminous masses would predict.[6] They acknowledge, however, that the notion of a new, non-luminous form of matter is difficult to accept. Yet many astronomers insist that they have observational evidence for which dark matter remains the only plausible explanation. One such communication comes from the Chandra X-ray Center, whose astronomers stated in 2006 that they had observed two galactic clusters for hundreds of hours, and that each one clearly showed a rotational speed consistent with far more mass than was visible.[7]
## Creationistic explanation
Creationism, of course, declares that any observed effect results from the creative action of God. In 2000, relying primarily on this theory, Don DeYoung, writing in the Creation Research Society Quarterly,[8] concluded that the hand of God was responsible for holding rapidly spinning galaxies and larger systems together, despite the observed mass deficits.
Most creation scientists, however, prefer to assume an economy of miracles. In that spirit, John Hartnett has produced a solution that requires no continuing miracle, but derives from a new understanding of the creation and expansion of the heavens.[1] Hartnett's system builds on the earlier work of Carmeli, who in 1996 proposed an extension of Einsteinian relativity to the cosmic scale (cosmological relativity). The Hartnett system, explained more fully in his work Starlight, Time and the New Physics, predicts that an expanding universe will produce rapidly spinning galaxies and larger systems as a consequence of the expansion and not due to gravity (or any other force) alone.
The key concept of the Carmeli-Hartnett cosmological relativity system is the description of the cosmos, not as space-time, but as space-mass-velocity. The velocity in view here is the radial velocity of objects in an expanding universe, which is always a function of the distance from the center of the expansion, as:
$v={\bigg (}{\frac {1}{\tau }}{\bigg )}r$
where $\tau$ is a constant (evaluated at 4.28 * 1017 s) that is the reciprocal of the Hubble factor H0 in weak gravity.[9]
More to the point, Carmeli and Hartnett showed that space itself expands in any galaxy or larger-sized object. Hartnett then showed that this expansion predicts a significantly increased rotational speed for any particle in that object.[10] Specifically,
$v^{4}=GM{\frac {2}{3}}a_{0}{\Bigg \{}{\bigg (}{\frac {R}{2a}}{\bigg )}^{{9/2}}8\Pi ^{{3/2}}{\Bigg \}}$
where R = radial position, a0 is a critical acceleration value, G is the gravitational constant, M is the total luminous mass of the galaxy (or group or cluster or supercluster) involved, and $\Pi$ depends on the Bessel functions of the ratio R/2a.
The above equation is very similar to the Tully-Fisher relation between luminosity and maximum rotational speed,[11][12]
$v^{4}\propto L$
where L = luminosity, or
$A=k+4\times \ln v$
where A = absolute magnitude. The Tully-Fisher relation was empirical, but Hartnett has given it a theoretical basis. Furthermore, the M given in Hartnett's equation is the regular luminous mass and not a Newtonian dynamical mass. Hence, no correction for any dark-matter proportion is necessary.
Hartnett tested his equation against the observed values of circular velocity of tracer gases in object NGC 3198 as a function of radial distance from the center. He found that this equation fit the observations almost exactly, while a traditional Newtonian equation for radial velocity,
$v^{2}={\frac {GM}{R}}$
predicted circular velocities much lower than observed. Hence Hartnett's conclusion that luminous masses are correct, but the physical model that predicts radial velocity is incorrect. Thus, as Einstein obviated the planet Vulcan, Hartnett now claims to obviate dark matter.
## Evolutionistic concept
### Estimated proportion
Cosmos percent composition.
The Wilkinson Microwave Anisotropy Probe (WMAP) team at NASA has used measurements of cosmic microwave background radiation[13] to determine that the universe is geometrically flat. According to standard cosmology, the universe should then be at a critical mass density of 9.9 * 10-27kg/m³. The actual mass density of the universe is more than twenty times less than that.[14]
Current theory suggests that the familiar baryonic matter (composed of atoms) constitutes only 4.6% of the total mass-energy in the universe. Dark matter constitutes 23% of the total, while dark energy comprises the remaining 72%.[14]
### Proposed explanations for dark matter
Evolutionistic astronomers have generally focused on the following explanations for the discrepancy between dynamical and luminous mass:
1. Brown dwarf stars and similarly massive but relatively non-luminous objects. Astronomers have in fact invented a new name for a class of objects that include brown dwarf stars and other massive objects: Massive Compact Halo Objects, or MACHOs.[3][5][14][15]
2. Supermassive black holes. Astronomers are now attempting to detect these objects by their relativistic effects on light, in which they act as lenses.[14]
3. New, previously unknown forms of matter. Many cosmologists have formed hypotheses that suggest entirely new particles of matter. They call these Weakly Interactive Massive Particle, or WIMPs.[14][3][5] Other cosmologists have suggested other types of particles, named axions.[1][16] The recently sought Higgs boson is another candidate for a dark-matter elementary particle.
4. A new theory of gravity. In 1983, Mordecai Milgrom first suggested that Newtonian dynamics was insufficient to explain the gravitational interactions of massive objects like galaxies and galactic clusters. He therefore suggested a Modified Newtonian Dynamic, or MOND, in which gravitational attraction varied inversely to the first power of the orbital radius, not its square as Newton originally assumed.[1][2]
Tim Thompson[2] has recently suggested yet another possibility to which most astronomers pay scant attention. He suggests that the major attractive force that allows galaxies and systems of higher mass to rotate with such excessive speed is not gravity at all, but electrostatic forces. He reminds his readers that electrostatic forces are stronger than gravity, and also that the strength of a magnetic field varies inversely as the first power, not the square, of the distance from the center. This is very close to Milgrom's MOND, with the advantage of having an underlying theory to explain it,[2] which Milgrom's system does not have.[1]
Don DeYoung challenged the notion of dark matter as a fanciful concept with little justification.[8] He pointed out that none of the conventional explanations popular at the time were satisfactory:
1. Non-luminous stars, the usual candidates for MACHOs, would have to be far more common than they actually are, by several orders of magnitude, for them to account for the mass deficit.
2. Black holes are a theoretical construct that have not thus far been verified.
3. Efforts to detect WIMPs and axions have thus far produced no definitive findings.
DeYoung also challenged the notion that galaxies or galactic clusters were necessarily stable. He did not comment directly on Milgrom's modified dynamic, but he did suggest that gravity was poorly understood.
Browse
## References
1. Hartnett, John. Starlight, Time and the New Physics. Creation Book Publishers, 2007. ISBN 9780949906687.
2. Thompson, Tim. "Missing 'Dark' Matter." The Electric Cosmos, n.d. Accessed July 28, 2008.
3. Silk, Joe. "Dark Matter." Department of Astronomy, University of California-Berkeley, ca. 1995. Accessed July 28, 2008.
4. Soter S and deGrasse-Tyson N, eds. "[Fritz Zwicky's Extraordinary Vision]." Excerpt from Cosmic Horizons: Astronomy at the Cutting Edge, New Press, 2000. ISBN 978-1565846029 Accessed July 28, 2008.
5. Miller CM. "Cosmic Hide and Seek: the Search for the Missing Mass." 1995. Accessed July 28, 2008.
6. Authors unknown. "Dark Matter Mystery." Field Guide to X-ray Astronomy, Chandra X-ray Center, Harvard University, Cambridge, MA, August 29, 2006. Accessed July 28, 2008.
7. Hupp E, Roy S., and Watzke M. "NASA Finds Direct Proof of Dark Matter." NASA, press release 06-297, August 21, 2006. Accessed July 28, 2008.
8. DeYoung DB. "Dark Matter." Creation Research Society Quarterly, 36(4), March 2000. Accessed July 28, 2008.
9. Evolutionistic astronomers might assume that this value gives the age of the universe; it does in fact give a value very close to the visible radius of the universe, measured in light-years. It probably does represent a value that an observer at the limits of the visible universe might measure for its age—because the Carmeli-Hartnett system also predicts tremendous time dilation at the center of the expansion.
10. Hartnett JG, "Spiral galaxy rotation curves determined from Carmelian general relativity," Int. J. Theor. Phys. 45 (2006) 2118-2136. arXiv:astro-ph/0511756 doi:10.1007/s10773-006-9178-0
11. Tully RB and Fisher JR, "A New Method of Determining Distance to Galaxies", Astron. Astrophys. 54, 661-673 (1977)
12. "The Tully-Fisher Relation," The Astroprof's Page, April 4, 2007
13. Hinshaw GF, and Griswold, B. "WMAP Mission Results." NASA, April 17, 2008. Accessed July 26, 2008.
14. Hinshaw GF, and Griswold B. "WMAP - Content of the universe." NASA, April 17, 2008. Accessed July 28, 2008.
15. White, Martin. "Dark Matter." Department of Astronomy, University of California at Berkeley, Berkeley, California, ca. 1995. Accessed July 28, 2008.
16. The name Axion is a registered trademark of the Colgate-Palmolive Company (USA) and was the name of a once-popular brand of laundry detergent used to pre-soak heavily-soiled garments before washing them with a conventional detergent. The astrophysicists who coined this name suggested that axions performed some kind of cosmic cleansing. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 8, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8922180533409119, "perplexity": 1829.4852429961886}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 5, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-13/segments/1521257645830.10/warc/CC-MAIN-20180318165408-20180318185408-00497.warc.gz"} |
https://mathematica.stackexchange.com/questions/71791/simplify-power-of-kroneckerdelta | # Simplify power of KroneckerDelta
Why doesn't Mathematica simplify the following expression:
FullSimplify[KroneckerDelta[x,y]^3]
Since KroneckerDelta only returns 0 or 1 the ^3 could be simply ignored.
Don't employ the simplification rule suggested in another proposed answer, since it will yield incorrect answers in many cases:
FullSimplify[KroneckerDelta[x, y]^2 f[x, y]/KroneckerDelta[x, y]]
(* f[x, y] KroneckerDelta[x, y] *)
Correct.
But if you apply the rule proposed elsewhere,
rule = KroneckerDelta[x_, y_]^n_ /; n > 0 -> KroneckerDelta[x, y];
to the numerator and denomiator:
myg[x, y] = KroneckerDelta[x, y]^2 f[x, y];
myh[x, y] = KroneckerDelta[x, y];
as here,
mynewg[x, y] = myg[x, y] /. rule;
mynewh[x, y] = myh[x, y] /. rule;
then the original term becomes
FullSimplify[mynewg[x, y]/mynewh[x, y]]
(* f[x, y] *)
Incorrect.
In short: leave the powers of the KroneckerDelta unaltered.
• You should not apply the rule before the end of operation. rule = KroneckerDelta[x_, y_]^n_ /; n > 0 -> KroneckerDelta[x, y]; myg[x, y] = KroneckerDelta[x, y]^2 f[x, y]; myh[x, y] = KroneckerDelta[x, y]; myg[x, y]/myh[x, y] /. rule yields f[x, y] KroneckerDelta[x, y] correct. Jan 16 '15 at 8:53
One method is to use the fact that KroneckerDelta is idempotent, so include this as an assumption to FullSimplify:
FullSimplify[
KroneckerDelta[x,y]^3,
KroneckerDelta[x,y]==KroneckerDelta[x,y]^2
]
KroneckerDelta[x, y]
Yes, it does not. If you need to actually simplify some expressions containing powers of Kroneker deltas you might want to use this rule:
rule = KroneckerDelta[x_, y_]^n_ /; n > 0 -> KroneckerDelta[x, y];
acting as follows:
KroneckerDelta[a, b]^3 /. rule
(* KroneckerDelta[a, b] *)
Have fun! | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.4686877131462097, "perplexity": 16373.537920570998}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-05/segments/1642320301263.50/warc/CC-MAIN-20220119033421-20220119063421-00165.warc.gz"} |
https://www.lmfdb.org/L/2/3584/448.13/c0-0 | ## Results (1-50 of 136 matches)
Next
Label $\alpha$ $A$ $d$ $N$ $\chi$ $\mu$ $\nu$ $w$ prim arith $\mathbb{Q}$ self-dual $\operatorname{Arg}(\epsilon)$ $r$ First zero Origin
2-3584-224.125-c0-0-0 $1.33$ $1.78$ $2$ $2^{9} \cdot 7$ 224.125 $$0.0 0 -0.468 0 0.184897 Modular form 3584.1.v.a.321.1 2-3584-224.125-c0-0-1 1.33 1.78 2 2^{9} \cdot 7 224.125$$ $0.0$ $0$ $-0.0937$ $0$ $0.867640$ Modular form 3584.1.v.b.321.1
2-3584-224.125-c0-0-2 $1.33$ $1.78$ $2$ $2^{9} \cdot 7$ 224.125 $$0.0 0 -0.0937 0 0.953420 Modular form 3584.1.v.c.321.1 2-3584-224.125-c0-0-3 1.33 1.78 2 2^{9} \cdot 7 224.125$$ $0.0$ $0$ $0.0312$ $0$ $1.31980$ Modular form 3584.1.v.d.321.1
2-3584-224.13-c0-0-0 $1.33$ $1.78$ $2$ $2^{9} \cdot 7$ 224.13 $$0.0 0 -0.218 0 0.571846 Modular form 3584.1.v.d.2113.1 2-3584-224.13-c0-0-1 1.33 1.78 2 2^{9} \cdot 7 224.13$$ $0.0$ $0$ $0.156$ $0$ $1.20205$ Modular form 3584.1.v.b.2113.1
2-3584-224.13-c0-0-2 $1.33$ $1.78$ $2$ $2^{9} \cdot 7$ 224.13 $$0.0 0 0.156 0 1.38353 Modular form 3584.1.v.c.2113.1 2-3584-224.13-c0-0-3 1.33 1.78 2 2^{9} \cdot 7 224.13$$ $0.0$ $0$ $0.281$ $0$ $1.70751$ Modular form 3584.1.v.a.2113.1
2-3584-224.181-c0-0-0 $1.33$ $1.78$ $2$ $2^{9} \cdot 7$ 224.181 $$0.0 0 -0.0312 0 1.24491 Modular form 3584.1.v.d.1217.1 2-3584-224.181-c0-0-1 1.33 1.78 2 2^{9} \cdot 7 224.181$$ $0.0$ $0$ $0.0937$ $0$ $1.25530$ Modular form 3584.1.v.c.1217.1
2-3584-224.181-c0-0-2 $1.33$ $1.78$ $2$ $2^{9} \cdot 7$ 224.181 $$0.0 0 0.0937 0 1.30207 Modular form 3584.1.v.b.1217.1 2-3584-224.181-c0-0-3 1.33 1.78 2 2^{9} \cdot 7 224.181$$ $0.0$ $0$ $0.468$ $0$ $2.03792$ Modular form 3584.1.v.a.1217.1
2-3584-224.69-c0-0-0 $1.33$ $1.78$ $2$ $2^{9} \cdot 7$ 224.69 $$0.0 0 -0.281 0 0.577810 Modular form 3584.1.v.a.3009.1 2-3584-224.69-c0-0-1 1.33 1.78 2 2^{9} \cdot 7 224.69$$ $0.0$ $0$ $-0.156$ $0$ $0.624178$ Modular form 3584.1.v.b.3009.1
2-3584-224.69-c0-0-2 $1.33$ $1.78$ $2$ $2^{9} \cdot 7$ 224.69 $$0.0 0 -0.156 0 0.800750 Modular form 3584.1.v.c.3009.1 2-3584-224.69-c0-0-3 1.33 1.78 2 2^{9} \cdot 7 224.69$$ $0.0$ $0$ $0.218$ $0$ $1.33818$ Modular form 3584.1.v.d.3009.1
2-3584-3584.1021-c0-0-0 $1.33$ $1.78$ $2$ $2^{9} \cdot 7$ 3584.1021 $$0.0 0 0.205 0 1.03301 Modular form 3584.1.cd.a.1021.1 2-3584-3584.1077-c0-0-0 1.33 1.78 2 2^{9} \cdot 7 3584.1077$$ $0.0$ $0$ $-0.0800$ $0$ $1.17447$ Modular form 3584.1.cd.a.1077.1
2-3584-3584.1133-c0-0-0 $1.33$ $1.78$ $2$ $2^{9} \cdot 7$ 3584.1133 $$0.0 0 0.0957 0 1.59169 Modular form 3584.1.cd.a.1133.1 2-3584-3584.1189-c0-0-0 1.33 1.78 2 2^{9} \cdot 7 3584.1189$$ $0.0$ $0$ $0.404$ $0$ $1.77903$ Modular form 3584.1.cd.a.1189.1
2-3584-3584.1245-c0-0-0 $1.33$ $1.78$ $2$ $2^{9} \cdot 7$ 3584.1245 $$0.0 0 0.205 0 1.44073 Modular form 3584.1.cd.a.1245.1 2-3584-3584.125-c0-0-0 1.33 1.78 2 2^{9} \cdot 7 3584.125$$ $0.0$ $0$ $-0.0449$ $0$ $1.07406$ Modular form 3584.1.cd.a.125.1
2-3584-3584.13-c0-0-0 $1.33$ $1.78$ $2$ $2^{9} \cdot 7$ 3584.13 $$0.0 0 0.158 0 1.02438 Modular form 3584.1.cd.a.13.1 2-3584-3584.1301-c0-0-0 1.33 1.78 2 2^{9} \cdot 7 3584.1301$$ $0.0$ $0$ $-0.330$ $0$ $0.598319$ Modular form 3584.1.cd.a.1301.1
2-3584-3584.1357-c0-0-0 $1.33$ $1.78$ $2$ $2^{9} \cdot 7$ 3584.1357 $$0.0 0 -0.0917 0 1.10214 Modular form 3584.1.cd.a.1357.1 2-3584-3584.1413-c0-0-0 1.33 1.78 2 2^{9} \cdot 7 3584.1413$$ $0.0$ $0$ $0.0917$ $0$ $0.921653$ Modular form 3584.1.cd.a.1413.1
2-3584-3584.1469-c0-0-0 $1.33$ $1.78$ $2$ $2^{9} \cdot 7$ 3584.1469 $$0.0 0 -0.419 0 0.512749 Modular form 3584.1.cd.a.1469.1 2-3584-3584.1525-c0-0-0 1.33 1.78 2 2^{9} \cdot 7 3584.1525$$ $0.0$ $0$ $0.0449$ $0$ $0.930736$ Modular form 3584.1.cd.a.1525.1
2-3584-3584.1581-c0-0-0 $1.33$ $1.78$ $2$ $2^{9} \cdot 7$ 3584.1581 $$0.0 0 -0.404 0 0.0239488 Modular form 3584.1.cd.a.1581.1 2-3584-3584.1637-c0-0-0 1.33 1.78 2 2^{9} \cdot 7 3584.1637$$ $0.0$ $0$ $-0.0957$ $0$ $0.740518$ Modular form 3584.1.cd.a.1637.1
2-3584-3584.1693-c0-0-0 $1.33$ $1.78$ $2$ $2^{9} \cdot 7$ 3584.1693 $$0.0 0 0.330 0 1.74325 Modular form 3584.1.cd.a.1693.1 2-3584-3584.1749-c0-0-0 1.33 1.78 2 2^{9} \cdot 7 3584.1749$$ $0.0$ $0$ $0.0449$ $0$ $0.744589$ Modular form 3584.1.cd.a.1749.1
2-3584-3584.1805-c0-0-0 $1.33$ $1.78$ $2$ $2^{9} \cdot 7$ 3584.1805 $$0.0 0 0.158 0 1.63476 Modular form 3584.1.cd.a.1805.1 2-3584-3584.181-c0-0-0 1.33 1.78 2 2^{9} \cdot 7 3584.181$$ $0.0$ $0$ $0.169$ $0$ $1.75598$ Modular form 3584.1.cd.a.181.1
2-3584-3584.1861-c0-0-0 $1.33$ $1.78$ $2$ $2^{9} \cdot 7$ 3584.1861 $$0.0 0 -0.158 0 1.16825 Modular form 3584.1.cd.a.1861.1 2-3584-3584.1917-c0-0-0 1.33 1.78 2 2^{9} \cdot 7 3584.1917$$ $0.0$ $0$ $0.455$ $0$ $1.84754$ Modular form 3584.1.cd.a.1917.1
2-3584-3584.1973-c0-0-0 $1.33$ $1.78$ $2$ $2^{9} \cdot 7$ 3584.1973 $$0.0 0 -0.330 0 0.554753 Modular form 3584.1.cd.a.1973.1 2-3584-3584.2029-c0-0-0 1.33 1.78 2 2^{9} \cdot 7 3584.2029$$ $0.0$ $0$ $-0.404$ $0$ $0.831846$ Modular form 3584.1.cd.a.2029.1
2-3584-3584.2085-c0-0-0 $1.33$ $1.78$ $2$ $2^{9} \cdot 7$ 3584.2085 $$0.0 0 -0.0957 0 1.26873 Modular form 3584.1.cd.a.2085.1 2-3584-3584.2141-c0-0-0 1.33 1.78 2 2^{9} \cdot 7 3584.2141$$ $0.0$ $0$ $-0.0449$ $0$ $1.57130$ Modular form 3584.1.cd.a.2141.1
2-3584-3584.2197-c0-0-0 $1.33$ $1.78$ $2$ $2^{9} \cdot 7$ 3584.2197 $$0.0 0 -0.0800 0 1.26380 Modular form 3584.1.cd.a.2197.1 2-3584-3584.2253-c0-0-0 1.33 1.78 2 2^{9} \cdot 7 3584.2253$$ $0.0$ $0$ $-0.0917$ $0$ $0.810309$ Modular form 3584.1.cd.a.2253.1
2-3584-3584.2309-c0-0-0 $1.33$ $1.78$ $2$ $2^{9} \cdot 7$ 3584.2309 $$0.0 0 0.0917 0 1.38927 Modular form 3584.1.cd.a.2309.1 2-3584-3584.2365-c0-0-0 1.33 1.78 2 2^{9} \cdot 7 3584.2365$$ $0.0$ $0$ $-0.169$ $0$ $0.833016$ Modular form 3584.1.cd.a.2365.1
2-3584-3584.237-c0-0-0 $1.33$ $1.78$ $2$ $2^{9} \cdot 7$ 3584.237 $$0.0 0 -0.404 0 1.74297 Modular form 3584.1.cd.a.237.1 2-3584-3584.2421-c0-0-0 1.33 1.78 2 2^{9} \cdot 7 3584.2421$$ $0.0$ $0$ $-0.205$ $0$ $1.23311$ Modular form 3584.1.cd.a.2421.1
2-3584-3584.2477-c0-0-0 $1.33$ $1.78$ $2$ $2^{9} \cdot 7$ 3584.2477 $$0.0 0 0.0957 0 1.03471 Modular form 3584.1.cd.a.2477.1 2-3584-3584.2533-c0-0-0 1.33 1.78 2 2^{9} \cdot 7 3584.2533$$ $0.0$ $0$ $0.404$ $0$ $1.56805$ Modular form 3584.1.cd.a.2533.1
2-3584-3584.2589-c0-0-0 $1.33$ $1.78$ $2$ $2^{9} \cdot 7$ 3584.2589 $$0.0 0 0.0800 0 0.778976 Modular form 3584.1.cd.a.2589.1 2-3584-3584.2645-c0-0-0 1.33 1.78 2 2^{9} \cdot 7 3584.2645$$ $0.0$ $0$ $0.294$ $0$ $2.06229$ Modular form 3584.1.cd.a.2645.1
Next | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9971159100532532, "perplexity": 472.88666805474054}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-27/segments/1656103821173.44/warc/CC-MAIN-20220630122857-20220630152857-00755.warc.gz"} |
http://annals.math.princeton.edu/articles/keyword/general-relativity | # Articles with article keyword: general relativity
## Decay for solutions of the wave equation on Kerr exterior spacetimes III: The full subextremalcase $|a| < M$
Pages 787-913 by Mihalis Dafermos, Igor Rodnianski, Yakov Shlapentokh-Rothman | From volume 183-3
## The global stability of Minkowski space-time in harmonic gauge
Pages 1401-1477 by Hans Lindblad, Igor Rodnianski | From volume 171-3 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.385374516248703, "perplexity": 16160.10211885002}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 5, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-39/segments/1568514573098.0/warc/CC-MAIN-20190917161045-20190917183045-00021.warc.gz"} |
https://blog.collegevine.com/sat-math-prep-lines-and-slopes/ | # SAT Math Prep: Lines and Slopes
## Is your SAT score enough to get you into your dream school?
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The SAT Math section can be challenging for many students. Fortunately, knowing what types of problems you’ll need to tackle and equations you’ll need to memorize is half the battle.
Lines and slopes are important concepts for the Heart of Algebra section of your math SAT. How can you prepare for this type of problem? Keep reading to learn all about lines and slopes, equations you should know, and examples (with explanations) to help you practice.
## What are Lines and Slopes?
A line is a one-dimensional figure that is completely straight with no curvature and no thickness. Made up of connected dots, it extends infinitely in both directions.
A slope, otherwise known as a gradient, is the measure of the steepness or slant of a line. It is the ratio of the rise (the change in distance vertically over the $$y$$-axis) to the run (the change in distance along the $$x$$-axis).
## What Line and Slope Properties Should You Know?
Before you attempt to tackle problems or memorize equations involving lines and slopes on your SAT, it’s important to understand some fundamental properties of these concepts. The basics include:
• Lines may increase or decrease and be horizontal or vertical.
• A line that increases in height from left to right has a positive slope. A line that decreases in height (gets lower) from left to right has a negative slope.
• A horizontal line has a slope of zero.
• A vertical line has an undefined slope.
• Parallel lines have the same slope and will never intersect.
• Perpendicular lines meet at right angles and have slopes that are negative reciprocals. This means that the product of slopes of perpendicular lines is $$-1$$.
## Lines and Slopes Formulas to Know
Formulas are provided on the SAT, but it will save you time to memorize important ones beforehand. That way, you can tackle the problems without having to flip back to check the formulas.
The equation of a line (also known as slope-intercept form):
$$y=mx+b$$
$$m$$ is the slope and $$b$$ is the $$y$$-intercept. It’s a good idea to rewrite any line equation into the form above to simplify solving any questions.
To find the slope:
$$\frac{y_2-y_1}{x_2-x_1}$$
This represents the change in $$y$$-values divided by the change in $$x$$-values. $$(x_1, y_1)$$ is a coordinate pair from the line, and $$(x_2, y_2)$$ is another coordinate pair from the same line.
As part of our free guidance platform, our Admissions Assessment tells you what schools you need to improve your SAT score for and by how much. Sign up to get started today.
## Examples of Lines and Slopes SAT Problems
Example #1
In the above problem, line $$k$$ passes through points $$(0,6)$$ and $$(3,0)$$.
Remember the formula for finding the slope of a line:
$$\frac{y_2-y_1}{x_2-x_1}$$
So in this case, the equation is
$$\frac{6-0}{0-3}$$
The result is $$-2$$.
Remember that the slopes of perpendicular lines have a product of $$-1$$, or must be negative reciprocals of each other. Therefore, the line perpendicular to line $$k$$ must have a slope of $$\frac{1}{2}$$.
In slope-intercept form, the coefficient of x is the slope of the line. So the correct answer is C, the equation with a slope of $$\frac{1}{2}: y=\frac{1}{2}x + 3$$.
Example #2
If line ℓ is translated up $$5$$ units and right $$7$$ units, then what is the slope of the new line?
A) $$\frac{2}{5}$$
B) $$\frac{−3}{2}$$
C) $$\frac{−8}{9}$$
D) $$\frac{−11}{14}$$
$$\frac{y_2-y_1}{x_2-x_1}$$
The key to answering this problem quickly and correctly is to remember that translating the line (moving the line somewhere else) will not change the slope of the line. Moving the line up $$5$$ units and over $$7$$ only changes the coordinates of line ℓ, but not the slope.
So, using the original points on the graph as indicators, $$(2,4)$$ and $$(0,7)$$, the slope of line ℓ would be:
$$\frac{4-7}{2-0}$$
In this case, the slope is $$\frac{-3}{2}$$, so the correct answer is B) $$\frac{-3}{2}$$.
## Wrapping it Up
For more practice questions to study up for the SAT, check out the 15 Hardest SAT Math Questions.
Looking for help acing your SAT? Download our free guide with our top 8 tips for mastering the SAT.
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Laura Berlinsky-Schine
Senior Blogger at CollegeVine
Short bio
Laura Berlinsky-Schine is a graduate of Johns Hopkins University, where she majored in Creative Writing and minored in History. She lives in Brooklyn, New York and works as a freelance writer specializing in education. She dreams of having a dog.
Other articles by Laura | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7001327872276306, "perplexity": 763.3795221573095}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-45/segments/1603107872686.18/warc/CC-MAIN-20201020105000-20201020135000-00570.warc.gz"} |
http://www.bihints.com/book/export/html/7 | This section is dedicated to various material for admins:
monitoring, troubleshooting, optimising...
backup
Before running the following script you need to setup a chore with a TI process to execute that line in Prolog:
SaveDataAll;
/!\ Avoid using the SaveTime setting in tm1s.cfg as it could conflict with other chores/processes trying to run at the same time
here is the DOS backup script that you can schedule to backup your TM1 server
netsvc /stop \\TM1server "TM1 service"
sleep 300
rmdir "\\computer2\path\to\backup" /S /Q
mkdir "\\computer2\path\to\backup"
xcopy "\\TM1server\path\to\server" "\\computer2\path\to\backup" /Y /R /S
xcopy "\\TM1server\path\to\server\}*" "\\computer2\path\to\backup" /Y /R /S
netsvc /start \\TM1server "TM1 service"
Documenting TM1
section dedicated to documenting TM1 with different techniques and tools.
a closer look at chores
if you ever loaded a .cho file in an editor this is what you would expect:
534,8
530,yyyymmddhhmmss ------ date/time of the first run
531,dddhhmmss ------ frequency
532,p ------ number p of processes to run
13,16
6,"process name"
560,0
13,16
533,x ------ x=1 active/ x=0 inactive
In the 9.1 series it is possible to see from the Server Explorer which chores are active from the chores menu.
However this is not the case in the 9.0 series, also it is not possible to see when and how often the chores are running unless you deactivate them first and edit them. Not quite convenient to say the least.
From the specs above, it is easy to set rules for a parser and deliver all that information in a simple report.
So the perl script attached below is doing just that: listing all chores on your server, their date/time of execution, frequency and activity status.
Procedure to follow:
1. install perl
2. save chores.pl in a folder
3. doubleclick on chores.pl
4. a window opens, enter the path to your TM1 server data folder there
5. open resulting file chores.txt created in the same folder as chores.pl
Result:
ACT / date-time / frequency / chore name
X 2005/08/15 04:55:00 007d 00h 00m 00s currentweek
X 2007/04/28 05:00:00 001d 00h 00m 00s DailyS
X 2007/05/30 05:50:00 001d 00h 00m 00s DAILY_UPDATE
X 2007/05/30 05:40:00 001d 00h 00m 00s DAILY_S_UPDATE
X 2005/08/13 20:00:05 007d 00h 00m 00s eweek
X 2006/04/06 07:30:00 001d 00h 00m 00s a_Daily
X 2007/05/30 06:05:00 001d 00h 00m 00s SaveDataAll
X 2007/05/28 05:20:00 007d 00h 00m 00s WEEKLY BUILD
X 2005/05/15 21:00:00 007d 00h 00m 00s weeklystock
2007/05/28 05:30:00 007d 00h 00m 00s WEEKLY_LOAD
a closer look at subsets
if you ever loaded a .sub file (subset) in an editor this is the format you would expect:
283,2 start
11,yyyymmddhhmmss creation date
274,"string" name of the alias to display
18,0 ?
275,d d = number of characters of the MDX expression stored on the next line
278,0 ?
281,b b = 0 or 1 "expand above" trigger
270,d d = number of elements in the subset followed by the list of these elements, this also represents the set of elements of {TM1SubsetBasis()} if you have an MDX expression attached
These .sub files are stored in cube}subs folders for public subsets or user/cube}subs for private subsets.
Often a source of discrepancy in views and reports is the use of static subsets. For example a view was created a while ago, displaying a bunch of customers, but since then new customers got added in the system and they will not appear in that view unless they are manually added to the static subset.
Based on the details above, one could search for all non-MDX/static subsets (wingrep regexp search 275,$in all .sub files) and identify which might actually need to be made dynamic in order to keep up with slowly changing dimensions. Beam me up Scotty: 3D Animated TM1 Data Flow Explore the structure of your TM1 system through the Skyrails 3D interface: If you do not have flash, you can have a look at some screenshots /!\ WARNING: your eyeballs may pop out! This is basically the same as the previous work with graphviz, except this time it is pushed to 3D, animated and interactive. So the visualisation engine Skyrails is developed by Ph.D. student Yose Widjaja. I only wrote the TM1 parser and associated Skyrails script to port a high level view of the TM1 Data flow into the Skyrails realm. How to proceed: .download and unzip skyrails beta 2nd build .download and unzip TM1skyrails.zip (attachment below) in the skyraildist2 folder .in the skyraildist2 folder, doubleclick TM1skyrails.pl (you will need perl installed unless someone wants to provide a compiled .exe of the script with the PAR module) .enter the path to (a copy of) your TM1 Data folder .skyrails window opens, click on the "folder" icon and click TM1 If you don't want to install perl, you can still enjoy a preview of the Planning Sample that comes out of the box. Just double-click on raex.exe. w,s,a,d keys to move the camera Quick legend: orange -- cube blue -- process light cyan -- file red -- ODBC source green sphere -- probably reference to an object that does not exists (anymore) green edge: intercube rule flow red edge: process (CellGet/CellPut) flow Changelog: 1.1 a few mouse gestures added (right click on a node then follow instructions) to get planar (like graphviz) and spherical representations. 1.2 - edges color coded, see legend above - animated arrows - gestures to display different flows (no flow/rules only/processes only/all flow) Dimensions updates mapping When faced with a large "undocumented" TM1 server, it might become hard to see how dimensions are being updated. The following perl/graphviz script creates a graph to display which processes are updating dimensions. That script dimflow.pl below is looking for functions updating dimensions (DimensionElementInsert, DimensionCreate...) in .pro files in the TM1 datafolder and maps it all together. Unfortunately it does not take into account manual editing of dimensions. This is the result: Legend: processes = red rectangles dimensions = blue bubbles The above screenshot is probably a good example of why such map can be useful: you can see immediately that several processes are updating the same dimensions. It might be necessary to have several processes feeding a dimension, though it will be good to review these processes to make sure they are not redundant or damaging each other's effects. Procedure to follow: 1. install perl and graphviz 2. download the script below and rename it to .pl extension 3. doubleclick on it 4. enter the path to your TM1 Data folder (\\servername\datafolder) 5. This will create 2 files "dim.dot" and "dim.gif" in the same folder as the perl script 6. Open dim.gif with any browser / picture editor graphing TM1 data flow Attached is the new version of a little parser in perl (free) that will create a text file for graphviz (free too) out of your .pro and .rux files and then generate a graph of the data flow in your TM1 server... (the image has been cropped and scaled down for display, the original image is actually readable) legend ellipses = cubes, rectangles = processes red = cellget, blue = cellput, green = inter-cube rule Procedure to follow: 1. install perl and graphviz 2. put the genflow perl script in any folder, make sure it has the .pl extension (not txt) 3. doubleclick on it 4. Enter the path to your TM1 Data folder such as: \\servername\datafolder where \\servername\datafolder is the full file path to your TM1 data folder 5. Hit return and wait until the window disappears This creates 2 files: "flow.dot" and "flow.gif" in the same folder as the perl script 6. Open "flow.gif" in any browser or picture editor Changelog 1.3: .CellPut parsing fix .cubes/processes names displayed 'as is' 1.4: .display import view names along the edges .display zeroout views .sources differentiated by shape This is still quite experimental but this could become useful to view at a glance high-level interactions between your cubes. indexing subsets Maintaining subsets on your server might be problematic. For example you wanted to delete an old subset that you found out to be incorrect and your server replied this: This is not quite helpful, as it does not say which views are affected and need to be corrected. Worse is that, as Admin, you can delete any public subset as long as it is not being used in a public view. If it is used in a user's private view, it will be deleted anyway and that private view might become invalid or just won't load. In order to remediate to these issues, I wrote a little perl script, attached below, that will: .index all your subsets, including users' subsets. .display all unused subsets (i.e. not attached to any existing views) From the index, you can find out right away in which views a given subset is used. I suppose the same could be achieved through the TM1 API though you would have to log as every user in turn in order to get a full index of all subsets. Run from a DOS shell: perl indexsubset.pl \\path\to\TM1\server > mysubsets.txt processes history On a large undocumented and mature TM1 server you might find yourself with a lot of processes and you wonder how many of them are still in use or the last time they got run. The following script answers these questions for you. One could take a look at the creation/modification time of the processes in the TM1 Data folder however you would have to sit through pages of the tms1msg.log to get the history of a given process which is what the script below does. Procedure to follow for TM1 9.0 or 8.x 1. install perl (free) 2. save loganalysis.pl.txt in a folder as loganalysis.pl 3. stop your TM1 service (necessary to beat the windows lock on tm1smsg.log) 4. copy the tm1smsg.log into the folder where loganalysis.pl is 5. start your TM1 service 6. double click loganalysis.pl Procedure to follow for TM1 9.1 1. install perl (free) 2. save loganalysis.pl.txt in a folder as loganalysis.pl 3. copy the tm1server.log into the folder where loganalysis.pl is 4. double click loganalysis.pl That should display the newly created processes.txt in notepad and that should look like the following: First, all processes sorted by name and the last run time, user and how many times it ran. processes by name: 2005load run 2006/02/09 15:02:33 user Admin [x2] ADMIN - Unused Dimensions run 2006/04/26 14:02:58 user Admin [x1] Branch Rates Update run 2006/10/19 15:23:29 user Admin [x1] BrandAnalysisUpdate run 2005/04/11 08:09:13 user Admin [x33] .... Second, all processes sorted by last run time, user and how many times it ran. processes by last run: 2005/04/11 08:09:13 user Admin ran BrandAnalysisUpdate [x33] 2005/04/11 10:26:29 user Admin ran LoadDelivery [x1] 2005/04/19 08:44:22 user Admin ran UpdateAntStockage [x19] 2005/04/26 14:18:17 user Admin ran weeklyodbc [x1] 2005/05/12 08:34:16 user Admin ran stock [x1] 2005/05/12 08:37:59 user Admin ran receipts [x1] .... I do not know what these "BrandAnalysisUpdate" or "LoadDelivery" processes do but I guess nobody is going to miss them. The case against single children I came across hierarchies holding single children. While creating a consolidation over only 1 element might make sense in some hierarchies, some people just use consolidations as an alternative to aliases. Either they just don't know they exist or they come from an age when TM1 did not have aliases yet. The following process will help you identify all the "single child" elements in your system. This effectively loops through all elements of all dimensions of your system, so this could be reused to carry out other checks. #where to report the results Report = '\\tm1server\reports\single_children.csv'; #get number of dimensions on that system TotalDim = Dimsiz('}Dimensions'); #loop through all dimensions i = 1; While (i <= TotalDim); ThisDim = DIMNM('}Dimensions',i); #foreach dimension #loop through all their elements j = 1; While (j <= Dimsiz(ThisDim)); Element = DIMNM(ThisDim,j); #report the parent if it has only 1 child If( ELCOMPN(ThisDim, Element) = 1 ); AsciiOutput(Report,ThisDim,Element,ELCOMP(ThisDim,Element,1)); Endif; #report if consolidation has no child!!! If( ELCOMPN(ThisDim, Element) = 0 & ELLEV(Thisdim, Element) > 0 ); single = single + 1; AsciiOutput(Report,ThisDim,DIMNM(ThisDim,j),'NO CHILD!!'); Endif; j = j + 1; End; i = i + 1; End; TM1 Documenter (a Documenting tool) Hi, Just FYR, New Version of TM1 Documenter Version2.5 (A documenting tool) has been released. I believe, it will very useful to TM1 Consultants & Developers, and the Organisations as well. Myself being a TM1 Consultant, know the pain-areas of a Consultant. Having a Java background; I developed this software. Usually documentation task takes about 20-40 days, thereby blocking a valuable resource (TM1 Developer) for such less-important task. By using this software, the documentation task will be completed in just few clicks. Moreover; during development or support task, when the model becomes huge or complex sometimes people lose the exact data flow of the model (as Rule sets are difficult to understand). Some times a developer ,by mistake, deletes an object (be it a cube, dimension, element, or a subset) that is providing is data to some other object. TM1 do not disallow to do so, but the model goes on a toss. Here the Object Dependency Checker comes to rescue. Software Summary: It has in all 2 Main Modules. I have introduced one new module in it, i.e. Object Dependency Checker Following are the details: Documenter Module: 1. Detailed information / summary of the cubes. 2. Cube Sizing. 3. Views info (optional). 4. Rules info (optional). 5. Detailed information / summary of the Dimensions. 6. Subsets info (optional). 7. Export TI Process list. 8. Export Dimension Attributes 9. Export Element Attributes 10.Output html file with index on left side & Object details in center pane that make easy to navigate the objects. Object Dependency Checker Module: 1. Cube Dependency: Select a cube & see all the other cubes depending on this. (i.e. view all cubes that are been sourced by this cube) 2. Dimension Dependency: Select a DIM & see all cubes & rules using this DIM. It also displays if this Dim is being used as Picklist anywhere. 3. Element Dependency: Select an Element from Dim & see all cubes using , specifically, this element Data. 4. Subset Dependency: Select a Subset & see all the views using this subset. It also displays if this Subset is being used as Picklist anywhere. 5. Cube-Element Dependency: This is detailed level element dependency. This module checks if the data of selected element of the selected cube is being used anywhere. 6. Export option available for all above sub-modules. so here it is. You can download it from:- (Please install this software with ADMIN RIGHTS) http://www.mediafire.com/?98q9a8tm9nu0w01 or https://rapidshare.com/files/3609668715/TM1_Documenter_Version2.5.rar Your suggestions & queries welcome. Please provide me feedback of this tool. Krishna krishna.dixit.sp@gmail.com dynamic tm1p.ini and homepages in Excel Pointing all your users to a single TM1 Admin host is convenient but not flexible if you manage several TM1 services. Each TM1 service might need different settings and you do not necessarily want users to be able to see the development or test services for example. Attached below is an addin that logs the users on a predefined server and settings as shown on that graph: With such a setup, you can basculate your users from one server to the other without having to tinker the tm1p.ini files on every single desktop. This solution probably offers the most flexibility and maintainability as you could add conditional statements to point different groups of users to different servers/settings and even manage and retrieve these settings from a cube through the API. This addin also includes: - previous code like the "TM1 freeze" button - it loads automatically an excel spreadsheet named after the user so each user can customise it with their reports/links for a faster access to their data. The TM1 macro OPTSET, used in the .xla below, can preconfigure the tm1p.ini with a lot more values. The official TM1 Help does not reference all the available values though. Here is a more complete list, you can actually change all the parameters displayed in the Server Explorer File->Options with OPTSET: AdminHost DataBaseDirectory IntegratedLogin ConnectLocalAtStartup InProcessLocalServer TM1PostScriptPrinter HttpProxyServerHost HttpProxyServerPort UseHttpProxyServer HttpConnectorUrl UseHttpConnector and more: AnsiFiles GenDBRW NoChangeMessage DimensionDownloadMaxSize this also applies to OPTGET WARNING: Make sure that all hosts in the AdminHost line are up and working otherwise Architect/Perspectives will hang for a couple of seconds while trying to connect to these hosts. free utilities If you are stuck with a Windows operating system, you might need some tools for basic needs, these are all free: for brute/regexp search in .pro and .rux files: WinGrep finding out changes in different versions of files: WinMerge or the PSPad editor Windirstat is quite a useful visualisation tool to clean up your drives/servers. A picture is worth a thousand words, take a look at the screenshot. It was first developed for KDE: kdirstat SnagIt can capture scrolling long web pages, extract text from windows, annotate images and more. Read the detailed SnagIt review. download here free license subscription here (thanks Eric!) A few more tools from lifehacker And finally, not a desktop tool per se, but quite useful to share files quick, easy and secure: http://drop.io How to monitor TM1 connections using a Java application Hello, download --> TM1Shell.rar. This program is a shell that allows you to connect to a TM1 server running. Then it starts two threads : - One write in a logfile the log activity on the server and save it; - The second allows you to have a description of dimensions, cubes, elements... and to export it into an Excel File. Use cmd to draw a list of available commands. The project is under construction, any suggestions welcome. A new version is coming out soon. If you have any questions, you can contact me : lucas.joignaux@gmail.com Locking and updating locked cubes Locking cubes is a good way to insure your (meta)data is not tampered with. Right click on the cube you wish to lock, then select Security->Lock. This now protects the cube contents from TI process and (un)intentional admins' changes. However, this makes updating your (meta)data more time consuming, as you need to remove the lock prior to updating the cube. Hopefully, the function CubeLockOverride allows you to automate that step. The following TI code demonstrates this, .lock a cube .copy/paste the code in a TI Prolog tab .change the parameters to fit your system .execute: # uncomment / comment the next line to see the process win / fail CubeLockOverride(1); Dim = 'Day'; Element = 'Day 01'; Attribute = 'Dates 2010'; NewValue = 'Saint Glinglin'; if( CellIsUpdateable('}ElementAttributes_' | Dim, Element, Attribute) = 1); AttrPutS(NewValue, Dim, Element, Attribute); else; ItemReject('could not unlock element ' | Element | ' in ' | Dim); endif; Note: CubeLockOverride is in the reserved words listed in the TM1 manual but its function seems to be only documented in the 8.4.5 releases notes. This works from 8.4.5 to the most recent 9.x series managing the licences limit One day you might face or already faced the problem of too many licences being in use and as a result additional users cannot log in. Also on a default setup, nothing stops users from opening several tm1web/perspectives sessions and reach the limit of licenses. So in order to prevent that: .open the cube }ClientProperties, change all users' MaximumPorts to 1 .in your tm1s.cfg add that line, it will timeout all idle connections after 1 hour: IdleConnectionTimeOutSeconds = 3600 To see who's logged on: .use tm1top or .open the cube }ClientProperties all logged users have the STATUS measure set to "ACTIVE" or .in server manager (rightclick server icon), click "Select clients..." to get the list To kick some users without taking the server down: in server explorer right click on your server icon -> Server Manager select disconnect clients and "Select clients..." then OK and they are gone. Unfortunately there is still no workaround for the admin to log in when users take all the slots allowed. monitor rules and processes Changing a rule or process in TM1 does not show up in the logs. That is fine as long as you are the only Power User able to tinker with these objects. Unfortunately, it can get out of hand pretty quickly as more power users join the party and make changes that might impact other departments data. So here goes a simple way to report changes. The idea is to compare the current files on the production server with a backup from the previous day. You will need: .access to the live TM1 Data Folder .access to the last daily backup .a VB script to email results you can find one there .diff, egrep and unix2dos, you can extract these from that zip package and http://www.efgh.com/software/unix2dos.exe or download directly the attachments below (GNU license) Dump these files in D:\TM1DATA\BIN for example, or some path accessible to the TM1 server. In the same folder create a diff.bat file, replace all the TM1DATA paths to your configuration: @echo off cd D:\TM1DATA\BIN del %~1 rem windows file compare fc is just crap, must fallback to the mighty GNU binutils diff -q "\\liveserver\TM1DATA" "\\backupserver\TM1DATA" | egrep "\.(pro|RUX|xdi|xru|cho)" > %~1 rem make it notepad friendly, i.e. add these horrible useless CR chars at EOL, it's 2oo8 but native windows apps are just as deficient as ever unix2dos %~1 rem if diff is not empty then email results if %~z1 GTR 1 sendattach.vbs mailserver 25 from.email to.email "[TM1] daily changes log" " " "D:\TM1DATA\BIN\%~1" Now you can set a TM1 process with the following line to run diff.bat and schedule it from a chore. ExecuteCommand('cmd /c D:\TM1DATA\BIN\diff.bat diff.txt',0); Best is to run the process at close of business, just before creating the backup of the day. And you should start receiving emails like these: Files \\liveserver\TM1DATA\Check Dimension CollectionCat.pro and \\backupserver\TM1DATA\Check Dimension CollectionCat.pro differ Files \\liveserver\TM1DATA\Productivity.RUX and \\backupserver\TM1DATA\Productivity.RUX differ Only in \\liveserver\TM1DATA: Update Cube Branch Rates.pro In this case we can see that the rules from the Productivity cube have changed today. monitoring chores by email Using the script in the Send Email Attachments article, it is possible to set it up to automatically email the Admin when a process in a chore fails. Here is how to proceed: 1. setup admin email process First we create a process to add an email field to the ClientProperties cube and add an email to forward to the Admin. 1.1 create a new process ---- Advanced/Parameters Tab, insert this parameter: AdminEmail / String / / "Admin Email?" --- Advanced/Prolog tab if(DIMIX('}ClientProperties','Email') = 0); DimensionElementInsert('}ClientProperties','','Email','S'); Endif; --- Advanced/Epilog tab CellPutS(AdminEmail,'}ClientProperties','Admin','Email'); 1.2 Save and Run 2. create monitor process ---- Advanced/Prolog tab MailServer = 'smtp.mycompany.com'; LogDir = '\\tm1server\e$\TM1Data\Log';
ScriptDir = 'E:\TM1Data\';
NumericGlobalVariable( 'ProcessReturnCode');
If(ProcessReturnCode <> ProcessExitNormal());
If(ProcessReturnCode = ProcessExitByChoreQuit());
Status = 'Exit by ChoreQuit';
Endif;
If(ProcessReturnCode = ProcessExitMinorError());
Status = 'Exit with Minor Error';
Endif;
If(ProcessReturnCode = ProcessExitByQuit());
Status = 'Exit by Quit';
Endif;
If(ProcessReturnCode = ProcessExitWithMessage());
Status = 'Exit with Message';
Endif;
If(ProcessReturnCode = ProcessExitSeriousError());
Status = 'Exit with Serious Error';
Endif;
If(ProcessReturnCode = ProcessExitOnInit());
Status = 'Exit on Init';
Endif;
If(ProcessReturnCode = ProcessExitByBreak());
Status = 'Exit by Break';
Endif;
vbody= 'Process failed: '|Status| '. Check '|LogDir;
If(Email @<> '');
S_Run='cmd /c '|ScriptDir|'\SendMail.vbs '| MailServer |' 25 '|Email|' '|Email|' "TM1 chore alert" "'|vBody|'"';
ExecuteCommand(S_Run,0);
Endif;
Endif;
2.1. adjust the LogDir, MailServer and ScriptDir values to your local settings
3. insert this monitor process in chore
This monitor process needs to be placed after every process that you would like to monitor.
How does it work?
Every process, after execution, returns a global variable "ProcessReturnCode", and that variable can be read by a process running right after in a chore.
The above process checks for that return code and pipes it to the mail script if it happens to be different from the normal exit code.
If you have a lot of processes in your chore, you will probably prefer to use the ExecuteProcess command and the check return code over a loop. That method is explained here.
monitoring chores by email part 2
Following up on monitoring chores by email, we will take a slightly different approach this time.
We use a "metaprocess" to execute all the processes listed in the original chore, check their return status and eventually act on it.
This allows for maximum flexibility as you can get that controlling process to react differently to any exit status of any process.
1. create process ProcessCheck
--- Data Source tab
choose ASCII, Data Source Name points to an already existing chore file, for example called Daily Update.cho
--- Variables tab
Variables tab has to be that way:
#mind that future TM1 versions might use a different format for .cho files and that might break this script If(Tag @= '6');
MailServer = 'mail.myserver.com'; LogDir = '\\server\f\$\TM1Data\myTM1\Log'; #get the process names from the deactivated chore Process=Measure; NumericGlobalVariable( 'ProcessReturnCode'); StringGlobalVariable('Status'); ErrorCode = ExecuteProcess(Process); If(ErrorCode <> ProcessExitNormal()); If(ProcessReturnCode = ProcessExitByChoreQuit()); Status = 'Exit by ChoreQuit'; #Honour the chore flow so stop here and quit too ChoreQuit; Endif; If(ProcessReturnCode = ProcessExitMinorError()); Status = 'Exit with Minor Error'; Endif; If(ProcessReturnCode = ProcessExitByQuit()); Status = 'Exit by Quit'; Endif; If(ProcessReturnCode = ProcessExitWithMessage()); Status = 'Exit with Message'; Endif; If(ProcessReturnCode = ProcessExitSeriousError()); Status = 'Exit with Serious Error'; Endif; If(ProcessReturnCode = ProcessExitOnInit()); Status = 'Exit on Init'; Endif; If(ProcessReturnCode = ProcessExitByBreak()); Status = 'Exit by Break'; Endif; vbody=Process|' failed: '|Status|'. Check details in '|LogDir; Email = CellGetS('}ClientProperties','Admin','Email'); If(Email @<> ''); S_Run='cmd /c F:\TM1Data\CDOMail.vbs '| MailServer |' 25 '|Email|' '|Email|' "TM1 chore alert" "'|vBody|'"'; ExecuteCommand(S_Run,0); Endif; Endif;
Endif;
The code only differs from the first method when the process returns a ChoreQuit exit. Because we will be running the chore Daily Update from another chore, the ChoreQuit will not apply to the later, so we need to specify it explicitly to respect the flow and stop at the same point.
2. create chore ProcessCheck
just add the process above and set it to the same frequency and time as the Daily Update chore that you want to monitor
3. deactivate Daily Update
since the ProcessCheck chore will run the Daily Update chore there is no need to execute Daily Update another time
a quick way to monitor users login/logout on your system is to log the STATUS value (i.e. ACTIVE or blank) from the }ClientProperties cube.
View->Display Control Objects
Cubes -rightclick- Security Assignments
browse down to the }ClientProperties cube and make sure the Logging box is checked
tm1server -rightclick- View Transaction Log
Select Cubes: }ClientProperties
All the transactions are stored in the tm1s.log file, however if you are on a TM1 version prior to version 9.1 and hosted on a Windows server, the file will be locked.
A "Save Data" will close the log file and add a timestamp to its name, so you can start playing with it.
/!\ This trick does not work in TM1 9.1SP3 as it does not update the STATUS value.
Oops I did it again!
OH NOOOEES! A luser just ran that hazardous process or spreading on the production server and as a result trashed loads of data on your beloved server.
You cannot afford to take the server down to get yesterday's backup and they need the data now...
Fear not, the transaction log is here to save the day.
.in server explorer, right click on server->View Transaction Log
.narrow the query as much as you can to the time/client/cube/measures that you are after
/!\ Mind the date is in north-american format mm/dd/yyyy
.Edit->Select All
.Edit->Back Out will rollback the selected entries
Alternatively, you could get the last backup of the corresponding .cub of the "damaged" cube
.overwrite the .cub with the backed up .cub
.reload the cube from server explorer by opening any view from it
Out of Memory
You will get the dreaded message "Out of Memory" if your TM1 server reaches beyond 2 GB of RAM.
On top of adding more RAM, you also need to add the /3GB flag in C:\boot.ini to extend the available space of the TM1 server from 2 to 3 GB, if you ever need more then you will have to look for a 64bit server.
C:\boot.ini before:
timeout=10
default=multi(0)disk(0)rdisk(0)partition(1)\WINDOWS
[operating systems]
multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows 2000 Advanced Server" /fastdetect
multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="restore mode" /safeboot:dsrepair /sos
C:\boot.ini after:
timeout=10
default=multi(0)disk(0)rdisk(0)partition(1)\WINDOWS
[operating systems]
multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows 2000 Advanced Server" /fastdetect /3GB
multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="restore mode" /safeboot:dsrepair /sos
This trick will work only for Windows 2000 Advanced or Datacenter Server and Windows 2003 Enterprise or Datacenter Edition.
It is also recommended that you restart your TM1 service daily in order to free up the RAM used from TM1 operations during the day.
http://support.microsoft.com/default.aspx?scid=kb;en-us;291988
After a RAM upgrade to 3 GB, you might still get the "Out of Memory" message when you are importing a lot of data at once although your server itself is actually using "only" 2.5 GB.
A way to circumvent that limit is to breakdown the import of data:
use SaveDataAll to commit the changes on disk after some import
then use CubeUnload(cube) of the cube that you just updated. That will free some space that can be used for importing further data for other cubes and that space will be used back to load that cube later once someone opens a view from that cube.
pushing data from an iSeries to TM1
TM1 chore scheduling is frequency based, i.e. it will run and try to pull data after a predefined period of time regardless of the availability of the data at the source. Unfortunately it can be a hit or miss and it can even become a maintenance issue when Daylight Saving Time come into play.
Ideally you would need to import or get the data pushed to TM1 as soon as it is available. The following article shows one way of achieving that goal with an iSeries as the source...
prerequesites on the TM1 server:
.iSeries Client Access components (iSeries Access for Windows Remote Command service)
Procedure to follow
1. drop TM1ChoreExecute, TM1ProcessExecute, associated files and the 32bit TM1 API dlls in a folder on the TM1 server (see readme in the zip for details)
2. start iSeries Access for Windows Remote Command on the TM1 server, set as automatic and select a user that can execute the TM1ChoreExecute
3. in client access setup: set remote incoming command "run as system" + "generic security"
10.xx.x.xx IP of your TM1 server
D:\path\to path where the TM1ChoreExecute is stored
TM1Server visible name of your TM1 Server (not the machine name of the machine running TM1.
UserID TM1 user ID with credentials to execute the chore.
ChoreName name of requested chore to be run to load data from the iSeries.
You should consider setting a user/pass to restrict access to the iSeries remote service and avoid abuse.
But ideally an equivalent of TM1ChoreExecute should be compiled and executed directly from the iSeries.
store any files in the Applications folder
The Applications folder is great but limited to views and xls files, well not anymore ;).
The following explains how to make available just any file in your Applications folders.
1. create a file called myfile.blob in }Applications\ on your TM1 server
it should contain the following 3 lines:
ENTRYNAME=tutorial.pdf
ENTRYTYPE=blob
ENTRYREFERENCE=TM!:///blob/public/.\}Externals\tutorial.pdf
2. place your file, tutorial.pdf in this case, in }Externals or whatever path you defined in ENTRYREFERENCE
ENTRYNAME is the name that will be displayed in Server Explorer.
ENTRYREFERENCE is the path to your actual file. The file does not need to be in the folder }Externals but the server must be able to access it
/!\ avoid large files, there is no sign to tell you to wait while loading, impatient users might click several times on the file and unvoluntarily flood the server or themselves.
/!\ add the extension in ENTRYNAME to avoid confusion, although it is not a .xls file, it will be displayed with an XLS icon.
TM1 services on the command line
removing a TM1 service
in a DOS shell:
go to the \bin folder where TM1 is installed then:
tm1sd -remove "TM1 Service"
where "TM1 Service is the name of an existing TM1 service
or: sc delete "TM1 Service"
sc delete TM1ExcelService
installing a TM1 service
in a DOS shell:
go to the \bin folder where TM1 is installed then:
tm1sd -install "TM1 Service" DIRCONFIG
where DIRCONFIG is the absolute path where the tm1s.cfg of your TM1 Service is stored
manually starting a TM1 service
from a DOS shell in the \bin folder of the TM1 installation:
tm1s -z DIRCONFIG
remotely start a TM1 service
netsvc /start \\TM1server "TM1 service"
sc \\TM1server start "TM1 service"
remotely stop a TM1 service
netsvc /stop \\TM1server "TM1 service"
sc \\TM1server stop "TM1 service"
more details on netsvc and sc
TM1 sudoku
Beyond the purely ludic and mathematical aspects of sudoku, this code demonstrates how to set up dimensions, cubes, views, cell formating, security at elements and cells levels all through Turbo Integrator in just one process.
Thanks to this application, you can prove your TM1 ROI: none of your company employees will ever need to shell out £1 for their daily sudoku from the Times.
Alternatively, you could move your users to a "probation" group before they start their shift. It is only by completing successfully the sudoku that the users will be moved back to their original group.
This way you can insure your company employees are mentally fit to carry out changes to the budget, especially after last evening ethylic abuses down the pub.
Of course it exists many sudoku available for Excel, this is one is to be played primarily from the cube viewer, but you could also slice the view and play it from Excel too.
How to install:
.Save the processes in your TM1 folder and reload your server or copy the code directly to new turbo integrator processes.
.Execute "Create Sudoku". That creates the cube, default view and new puzzle in less than a second.
sudoku
The user can input numbers in the "input" grid only where there are zeroes. The "solution" grid cannot be read by default.
.Execute "Check Sudoku" to verify your input grid matches the solution.
If you are logged under an admin account, you will not see any cells locked, you need to be under the group defined in the process to see the cells properly locked.
You might want to change the default group allowed to play and the number of initial pairs that are blanked in order to increase difficulty.
The algorithm provided to generate the sudoku could be quickly modified to solve by brute force any sudoku. Provided the sudoku grid is valid, it will find the solution, however some sudokus with too many empty cells will have more than one solution.
This post is published on April 1st, but I can assure you the code is not an April's fool, it works and it was tested on TM1 9.0.3.
TM1Top
realtime monitoring of your TM1 server, pretty much like the GNU top command.
It is bundled with TM1 only from version 9.1. You might have to ask your support contact to get it or get Ben Hill's TM1Top below.
. dump the files in a folder
servername=myserver
refresh=5
logfile=C:\tm1top.log
logperiod=0
logappend=T
. run the tm1top.exe
Commands:
X exit
W write display to a file
H help
V verify/login to allow cancelling jobs
Keep in mind all it does is to insert a "ProcessQuit" command in the chosen thread.
Hence it will not work if the user is calculating a large view or a TI is stuck in a loop where it never reads the next data record, as the quit command is entered for the next data line rather than the next line of code. Then your only option becomes to terminate the user's connection with the server manager or API. (thanks Steve Vincent).
Ben "Kyro" Hill did a great job developing a very convenient GUI TM1Top. You can find it attached below.
(green = mostly idle, orange = user data request, red = process running/rule saving/overload)
tm1web customizer
The tm1web customizer will allow you to change the default logos and color schemes of tm1web from a graphical interface.
That is trying to make it more convenient to customize your tm1web without having to dig in the code.
It can be found here: ftp://ftp.applix.com/pub/Gruenes/TM1WebAppCustomizer.zip
However note that it is configured to work with 9SP1.
TM1Web vs TM1 Server Explorer DeathMatch
I have a strong dislike for TM1Web and here is why...
Quick Traffic Analysis comparison
On the recommended practices site from Applix, the following article TM1 Deployment Options and Network Bandwidth Considerations claims that TM1Web is more suited to low bandwidth networks.
O RLY? So I decided to give it a go with Wireshark, great network analysis tool, used to be known as Ethereal.
I do 2 runs, one with Server Explorer (direct over TCP/IP no HTTP), the other with TM1Web
The analysis takes place between a Windows XP client and Windows 2000 Advanced server hosting TM1. Both are using TM1 9.0SP2, the only customisation brought to TM1Web was to remove the top left TM1 logo so that should have only a neglectable effect on the statistics.
In each case:
.close all connections to TM1 server
.on the client host, Wireshark capture filter set to log only packets to and from the TM1 Server
Capture -> Options
set Interface to the ethernet card in use
set capture filter to that string: host "TM1 server IP"
if the TM1 server has the IP 192.168.0.10 then the capture filter must be:
host 192.168.0.10
.check the capture baseline is flat to be sure there will be no other traffic
.start logging packets just before opening the view
.open a "decent" view, 412 rows x 8 columns
.scroll through all the rows until bottom is reached
.stop logging
Results (in Wireshark, Statistics -> Summary):
978 kBytes went through the network with TM1Web
150 kBytes went through the network with server explorer/cube viewer
So much for saving bandwidth with TM1Web, it is actually consuming at least 5 times more traffic than Server Explorer.
If I get more time I will look in the packets to see why there is so much overhead with TM1Web, my initial guess is this is caused by the additional HTTP protocol layer.
This time I tried with another view, 7 dimensions, 415 rows by 9 columns
similar results:
947 kB for TM1 Web
147 kB for cube viewer
And I pushed the analysis a bit further.
Wireshark Menu: Statistics -> Protocol Hierarchy
As you can see HTTP takes up only 8.7% of the total traffic, but that is already 47 kBytes just to embed data on the wire, cube viewer would have already transfered 30% of the view in the same amount of bytes!
Now let's breakdown the conversation between the client and server.
From the Wireshark menu: Statistics -> Conversation List -> TCP
The popup window now displays the TCP conversations by size, the fattest are at the bottom.
So let's see what is causing all that traffic...
Right click the last one: Apply As Filter-> Selected -> A--B | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.19842447340488434, "perplexity": 7811.310212623677}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-11/segments/1424936462720.36/warc/CC-MAIN-20150226074102-00285-ip-10-28-5-156.ec2.internal.warc.gz"} |
http://mathematica.stackexchange.com/questions/10320/selecting-polynomial-roots-and-plotting-against-parameters/10324 | # Selecting polynomial roots and plotting against parameters
An implicit function $f(x,k)=0$ is quadratic in $x$ and contains one parameter $k$ which I must vary. Using Solve, I get two real solutions for each specific $k$: $x_1$ and $x_2$, of which I must choose the one that lies within $[0, 0.5]$. I must do this for a continuum of parameters $k$ between, say, $0$ and $1$. I then must plot the relevant $x$ solution against the parameter $k$ in a smooth curve.
Note: I also tried the unglorious method i.e. if $k$ took discrete values, I thought I could manually select say 30 points and interpolate. But any curve fitting command I tried, using various polynomial and exponential expansions, could not give me smooth curve?
Of course I hope to learn the elegant method, but under time pressure anything that gives me a smooth curve is welcome!
-
A lot easier if you show what f looks like. – b.gatessucks Sep 7 '12 at 7:44
Well, FindRoot[] supports the option of root bracketing; if all you want is an approximate root, it should be fine. Otherwise, since you say it's quadratic in $x$, one could always manipulate the quadratic formula... – Ｊ. Ｍ. Sep 7 '12 at 8:14
As J. M. says, FindRoot allows two options: either root bracketing, or the simpler choice of starting with an initial approximation for the root that is close enough. Since you said your root is unique in the [0,0.5] interval, and your function is smooth, you can expect that a starting value of 0.25 will usually give you the root you're looking for.
f[x_] := Expand[(x - 0.5*Sin[k^2])*(x - 3*k - 1)]
Plot[x /. FindRoot[f[x], {x, 0.25}], {k, 0, 1}]
-
Additionally, as a guarantee that the iteration never veers off the brackets you have set up, use Brent's method (i.e. append the option setting Method -> "Brent" to FindRoot[]). – Ｊ. Ｍ. Sep 7 '12 at 9:48
Thank you, it works. Only thing is, when desireable solutions x*(k) approach 0 as parameter k is changed towards one end of the parameter range, the solution becomes discontinuous ..although i know there does exist a finite, smooth x(k).. – user2297 Sep 14 '12 at 9:18
@ridwandrusli we have no way of helping you more if you don't post your function (or better, your current code) – F'x Sep 14 '12 at 9:35 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5554126501083374, "perplexity": 1241.1230742751195}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-23/segments/1405997869778.45/warc/CC-MAIN-20140722025749-00146-ip-10-33-131-23.ec2.internal.warc.gz"} |
http://eprint.iacr.org/2000/013 | Cryptology ePrint Archive: Report 2000/013
Concurrent Zero-Knowledge in Poly-logarithmic Rounds
Joe Kilian and Erez Petrank
Abstract: A proof is concurrent zero-knowledge if it remains zero-knowledge when run in an asynchronous environment, such as the Internet. It is known that zero-knowledge is not necessarily preserved in such an environment; Kilian, Petrank and Rackoff have shown that any {\bf 4} rounds zero-knowledge interactive proof (for a non-trivial language) is not concurrent zero-knowledge. On the other hand, Richardson and Kilian have shown that there exists a concurrent zero-knowledge argument for all languages in NP, but it requires a {\bf polynomial} number of rounds. In this paper, we present a concurrent zero-knowledge proof for all languages in NP with a drastically improved complexity: our proof requires only a poly-logarithmic, specifically, $\omega(\log^2 k)$ number of rounds. Thus, we narrow the huge gap between the known upper and lower bounds on the number of rounds required for a zero-knowledge proof that is robust for asynchronous composition.
Category / Keywords: foundations / zero-knowledge
Date: received 24 Apr 2000, revised 28 May 2000
Contact author: erez at cs technion ac il
Available format(s): Postscript (PS) | Compressed Postscript (PS.GZ) | PDF | BibTeX Citation
Short URL: ia.cr/2000/013
[ Cryptology ePrint archive ] | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9006710052490234, "perplexity": 3673.1097319563955}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2016-40/segments/1474738660957.45/warc/CC-MAIN-20160924173740-00251-ip-10-143-35-109.ec2.internal.warc.gz"} |
https://export.arxiv.org/abs/2102.04896 | q-bio.NC
(what is this?)
# Title: Formalising the Use of the Activation Function in Neural Inference
Abstract: We investigate how the activation function can be used to describe neural firing in an abstract way, and in turn, why it works well in artificial neural networks. We discuss how a spike in a biological neurone belongs to a particular universality class of phase transitions in statistical physics. We then show that the artificial neurone is, mathematically, a mean field model of biological neural membrane dynamics, which arises from modelling spiking as a phase transition. This allows us to treat selective neural firing in an abstract way, and formalise the role of the activation function in perceptron learning. The resultant statistical physical model allows us to recover the expressions for some known activation functions as various special cases. Along with deriving this model and specifying the analogous neural case, we analyse the phase transition to understand the physics of neural network learning. Together, it is shown that there is not only a biological meaning, but a physical justification, for the emergence and performance of typical activation functions; implications for neural learning and inference are also discussed.
Comments: Six pages and one of references, two figures Subjects: Neurons and Cognition (q-bio.NC); Disordered Systems and Neural Networks (cond-mat.dis-nn); Statistical Mechanics (cond-mat.stat-mech); Machine Learning (stat.ML) Cite as: arXiv:2102.04896 [q-bio.NC] (or arXiv:2102.04896v2 [q-bio.NC] for this version) | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8049294352531433, "perplexity": 851.3597868124239}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-39/segments/1631780056120.36/warc/CC-MAIN-20210918002951-20210918032951-00128.warc.gz"} |
https://www.imath.kiev.ua/~sigma/2018/083/ | ### Symmetry, Integrability and Geometry: Methods and Applications (SIGMA)
SIGMA 14 (2018), 083, 22 pages arXiv:1801.01313 https://doi.org/10.3842/SIGMA.2018.083
### Thinplate Splines on the Sphere
Rick K. Beatson a and Wolfgang zu Castell bc
a) School of Mathematics and Statistics, University of Canterbury, Private Bag 4800, Christchurch, New Zealand
b) Scientific Computing Research Unit, Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85764 Neuherberg, Germany
c) Department of Mathematics, Technische Universität München, Germany
Received January 08, 2018, in final form July 30, 2018; Published online August 12, 2018
Abstract
In this paper we give explicit closed forms for the semi-reproducing kernels associated with thinplate spline interpolation on the sphere. Polyharmonic or thinplate splines for ${\mathbb R}^d$ were introduced by Duchon and have become a widely used tool in myriad applications. The analogues for ${\mathbb S}^{d-1}$ are the thin plate splines for the sphere. The topic was first discussed by Wahba in the early 1980's, for the ${\mathbb S}^2$ case. Wahba presented the associated semi-reproducing kernels as infinite series. These semi-reproducing kernels play a central role in expressions for the solution of the associated spline interpolation and smoothing problems. The main aims of the current paper are to give a recurrence for the semi-reproducing kernels, and also to use the recurrence to obtain explicit closed form expressions for many of these kernels. The closed form expressions will in many cases be significantly faster to evaluate than the series expansions. This will enhance the practicality of using these thinplate splines for the sphere in computations.
Key words: positive definite functions; zonal functions; thinplate splines; ultraspherical expansions; Gegenbauer polynomials.
pdf (465 kb) tex (25 kb)
References
1. Abramowitz M., Stegun I.A. (Editors), Handbook of mathematical functions, with formulas, graphs, and mathematical tables, Dover Publications, Inc., New York, 1966.
2. Atteia M., Hilbertian kernels and spline functions, Studies in Computational Mathematics, Vol. 4, North-Holland Publishing Co., Amsterdam, 1992.
3. Berlinet A., Thomas-Agnan C., Reproducing kernel Hilbert spaces in probability and statistics, Kluwer Academic Publishers, Boston, MA, 2004.
4. Bezhaev A.Yu., Vasilenko V.A., Variational theory of splines, Springer, Boston, MA, 2001.
5. Bognár J., Indefinite inner product spaces, Ergebnisse der Mathematik und ihrer Grenzgebiete, Vol. 78, Springer-Verlag, New York - Heidelberg, 1974.
6. Chen D., Menegatto V.A., Sun X., A necessary and sufficient condition for strictly positive definite functions on spheres, Proc. Amer. Math. Soc. 131 (2003), 2733-2740.
7. Cheney W., Light W., A course in approximation theory, Graduate Studies in Mathematics, Vol. 101, Amer. Math. Soc., Providence, RI, 2009.
8. Dai F., Xu Y., Approximation theory and harmonic analysis on spheres and balls, Springer Monographs in Mathematics, Springer, New York, 2013.
9. Davis P.J., Interpolation and approximation, Dover Publications, Inc., New York, 1975.
10. Duchon J., Interpolation des fonctions de deux variables suivant le principe de la flexion des plaques minces, Rev. Française Automat. Informat. Recherche Opérationnelle Sér. 10 (1976), 5-12.
11. Duchon J., Splines minimizing rotation-invariant semi-norms in Sobolev spaces, in Constructive Theory of Functions of Several Variables (Proc. Conf., Math. Res. Inst., Oberwolfach, 1976), Lecture Notes in Math., Vol. 571, Editors W. Schempp, K. Zeller, Springer, Berlin, 1977, 85-100.
12. Freeden W., Gervens T., Schreiner M., Constructive approximation on the sphere: with applications to geomathematics, Numerical Mathematics and Scientific Computation, The Clarendon Press, Oxford University Press, New York, 1998.
13. Gneiting T., Strictly and non-strictly positive definite functions on spheres, Bernoulli 19 (2013), 1327-1349, arXiv:1111.7077.
14. Laurent P.-J., Inf-convolution splines, Constr. Approx. 7 (1991), 469-484.
15. Levesley J., Light W., Ragozin D., Sun X., A simple approach to the variational theory for interpolation on spheres, in New Developments in Approximation Theory (Dortmund, 1998), Internat. Ser. Numer. Math., Vol. 132, Birkhäuser, Basel, 1999, 117-143.
16. Martinez-Morales J.L., Generalized Legendre series and the fundamental solution of the Laplacian on the $n$-sphere, Anal. Math. 31 (2005), 131-150.
17. Meinguet J., Multivariate interpolation at arbitrary points made simple, Z. Angew. Math. Phys. 30 (1979), 292-304.
18. Menegatto V.A., Oliveira C.P., Peron A.P., Strictly positive definite kernels on subsets of the complex plane, Comput. Math. Appl. 51 (2006), 1233-1250.
19. NIST digital library of mathematical functions, Release 1.0.10 of 2015-08-07, available at https://dlmf.nist.gov/.
20. Mosamam A.M., Kent J.T., Semi-reproducing kernel Hilbert spaces, splines and increment kriging, J. Nonparametr. Stat. 22 (2010), 711-722.
21. Strauss H., Extremal properties of conditionally positive definite functions, in Approximation Theory, X (St. Louis, MO, 2001), Innov. Appl. Math., Vanderbilt University Press, Nashville, TN, 2002, 441-452.
22. Wahba G., Spline interpolation and smoothing on the sphere, SIAM J. Sci. Statist. Comput. 2 (1981), 5-16.
23. Wahba G., Erratum: ''Spline interpolation and smoothing on the sphere'', SIAM J. Sci. Statist. Comput. 3 (1982), 385-386.
24. Wahba G., Spline models for observational data, CBMS-NSF Regional Conference Series in Applied Mathematics, Vol. 59, Society for Industrial and Applied Mathematics, Philadelphia, PA, 1990. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8347718119621277, "perplexity": 2813.4225313792103}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 5, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-35/segments/1566027317037.24/warc/CC-MAIN-20190822084513-20190822110513-00398.warc.gz"} |
http://mathhelpforum.com/algebra/18481-problems-indices-print.html | # Problems with indices
• Sep 4th 2007, 08:22 AM
Coach
Problems with indices
((a^4)b)/(c^2)^^-1/2
Thank you!
• Sep 4th 2007, 08:26 AM
Krizalid
Not much you can do from there...
$\left(\frac{a^4b}{c^2}\right)^{-1/2}$
Is this thing you wanna reduce?
• Sep 4th 2007, 08:54 AM
Coach
Yes, I am sorry I do not know how to use tags.
I tried to take away the fractions by multiplying by a^2 and c, but I couldn't
• Sep 4th 2007, 08:58 AM
Krizalid
See the LaTeX Tutorial
Now, we have that $\left(\frac{c^2}{a^4b}\right)^{1/2}=\frac c{a^2\sqrt{b}}$
Does that make sense?
• Sep 4th 2007, 09:16 AM
Coach
Yes that makes sense, but according to my math book the answer is $\frac{c\sqrt{b}}{a^2 b}$ .
• Sep 4th 2007, 10:12 AM
Krizalid
Quote:
Originally Posted by Coach
Yes that makes sense, but according to my math book the answer is $\frac{c\sqrt{b}}{a^2 b}$ .
What's the matter? :D:D
Multiply numerator and denominator by $\sqrt b$ to my answer and you'll get the desired. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 5, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9690054655075073, "perplexity": 2457.632305657547}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-17/segments/1492917121453.27/warc/CC-MAIN-20170423031201-00109-ip-10-145-167-34.ec2.internal.warc.gz"} |
https://www.physicsforums.com/threads/an-implementation-of-gausss-law.157498/ | # AN implementation of gauss's law
1. Feb 21, 2007
### impendingChaos
A long solid nonconducting cylinder or radius R1 is uniformly charged with a charge density (p). It is surrounded by a concentric cylindrical tube or innder radius R2 and outer radius R3, it also has uniform charge density, p. Before I can go on i need to find the electric field as a function of the distance r from the center for (a) 0<r<R1 (b) R1<r<R2 (c) R2<r<R3 and (d) r>R3)
The integration is screwing me up, thanks
Kael.
2. Feb 21, 2007
### impendingChaos
To state my current attempt:
for part (a) i know
p=Q/4*pi*permittivity of free space*R1^2*L
V(enclosed)=pi*r^2*L
so p*V(enclosed)= the ratio (r^2/R1^2)Q which is the total Q enclosed
3. Feb 21, 2007
### Staff: Mentor
You shouldn't need to do any integration. Hint: Write Gauss's law, which will give you the total flux through a surface in terms of the enclosed charge. (The enclosed charge is just the charge density times the volume.) Use a cylindrical Gaussian surface, of course, to take advantage of symmetry.
4. Feb 21, 2007
### impendingChaos
Ok ok I'm starting to see it, so i would have
(permittivity of free space= Eo)
int(E) x dA = Q(enc)/Eo
EA= (r^2/R1^2)Q/Eo
then dividing both sides by the area would give E?
and if so would I need to use the left side of the equation divided by the area of the face of the cylinder plus the equation divided by the area of the length of the cylinder?
5. Feb 21, 2007
### Staff: Mentor
OK.
Almost there. Get rid of Q. You are given charge density, not Q. (As I suggested earlier, express the enclosed charge as charge density times the volume.)
Express area and volume in terms of r.
6. Feb 21, 2007
### impendingChaos
hmm, well i thought i did that since if
charge density = Q/(4pi*L*R1^2)
and the volume is pi*L*r^2
then multiplying the two would give (Q*r^2)/(4*R1^2)
ok, now I take this Q(enc) and put it Gauss to obtain:
EA=(Q*r^2)/(4*R1^2*Eo)
but you said Q is not present?
In any case I continued from this by divinding the right side by A which would give me my electric field. Now, do I need to do this for the ends AND the length of the tube or are the ends considered negligible since it is "very long." I have solved it and obtained the correct answer but only when excluding the ends of this tube such that
E=pr/2Eo (this is the stated result)
So now, assuming the math was correct, is there a reason I should be considering the ends to be zero?
7. Feb 21, 2007
### Staff: Mentor
Well, you tell me. If you aren't given Q, how can your answer be in terms of it? You are given the charge density though.
You are presumably finding the field at positions far enough from the ends so that any non-uniformity of field can be neglected. Your Gaussian surface is a cylindrical section in the middle of the long rod.
When you are finding the electric flux through the Gaussian surface, you are multiplying the area times the component of E perpendicular to that surface. In which case, what would be the flux through the end pieces of that Gaussian cylinder?
8. Feb 21, 2007
### impendingChaos
Zero! :rofl:
9. Feb 21, 2007
### Staff: Mentor
Exactamundo!
10. Feb 21, 2007
### impendingChaos
Thanks alot, I think I can get parts b through c from here!
Similar Discussions: AN implementation of gauss's law | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9653425216674805, "perplexity": 968.4132002509}, "config": {"markdown_headings": true, "markdown_code": false, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-09/segments/1518891811352.60/warc/CC-MAIN-20180218023321-20180218043321-00313.warc.gz"} |
http://www.dummies.com/education/math/pre-algebra/how-to-use-the-metric-system/ | # How to Use the Metric System
The metric system provides units of measurement for distance, volume, mass, time, and temperature. It builds these units using a basic unit and a set of prefixes.
The following list shows five important basic units in the metric system.
The following table shows ten metric prefixes, with the three most commonly used in bold.
Prefix Meaning Number Power of Ten
Giga- One billion 1,000,000,000 109
Mega- One million 1,000,000 106
Kilo- One thousand 1,000 103
Hecta- One hundred 100 102
Deca- Ten 10 101
(none) One 1 100
Deci- One tenth 0.1 10-1
Centi- One hundredth 0.01 10-2
Milli- One thousandth 0.001 10-3
Micro- One millionth 0.000001 10-6
Nano- One billionth 0.000000001 10-9
Large and small metric units are formed by linking a basic unit with a prefix. For example, linking the prefix kilo- to the basic unit meter gives you the kilometer, which means 1,000 meters. Similarly, linking the prefix milli- to the basic unit liter gives you the milliliter, which means 0.001 (one thousandth) of a liter.
Here’s a list giving you the basics:
• Units of distance: The basic metric unit of distance is the meter (m). Other common units are millimeters (mm), centimeters (cm), and kilometers (km):
1 kilometer = 1,000 meters
1 meter = 100 centimeters
1 meter = 1,000 millimeters
• Units of fluid volume: The basic metric unit of fluid volume (also called capacity) is the liter (L). Another common unit is the milliliter (mL):
1 liter = 1,000 milliliters
Note: One milliliter is equal to 1 cubic centimeter (cc).
• Units of mass: Technically speaking, the metric system measures not weight but mass. Weight is the measurement of how strongly gravity pulls an object toward Earth. Mass, however, is the measurement of the amount of matter an object has. If you traveled to the moon, your weight would change, so you would feel lighter. But your mass would remain the same, so all of you would still be there. Unless you’re planning a trip into outer space or performing a scientific experiment, you probably don’t need to know the difference between weight and mass.
The basic unit of weight in the metric system is the gram (g). Even more commonly used, however, is the kilogram (kg):
1 kilogram = 1,000 grams
Note: 1 kilogram of water has a volume of 1 liter.
• Units of time: As in the English system, the basic metric unit of time is a second (s). For most purposes, people also use other English units such as minutes, hours, and so forth.
For many scientific purposes, the second is the only unit used to measure time. Large numbers of seconds and small fractions of sections are represented with scientific notation.
• Units of speed: For most purposes, the most common metric unit of speed (also called velocity) is kilometers per hour (km/hr). Another common unit is meters per second (m/s).
• Units of temperature (degrees Celsius or Centigrade): The basic metric unit of temperature is the Celsius degree (°C), also called the Centigrade degree. The Celsius scale is set up so that at sea level, water freezes at 0°C and boils at 100°C.
Scientists often use another unit — the Kelvin (K) — to talk about temperature. The degrees are the same size as in Celsius, but 0 K is set at absolute zero, the temperature at which atoms don’t move at all. Absolute zero is approximately equal to –273.15°C. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9425111413002014, "perplexity": 1930.5920029321883}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-13/segments/1490218186895.51/warc/CC-MAIN-20170322212946-00528-ip-10-233-31-227.ec2.internal.warc.gz"} |
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https://infoscience.epfl.ch/record/31718 | ## Analyse mathématique et numérique d'un modèle de chauffage par induction
In this work, we deal with a mathematical model of heat induction processes. We first build a model derived from Maxwell and heat equations and, using certain simplifying assumptions, we obtain a system of coupled partial differential equations describing the evolution of thermal and magnetic fields. We show that this evolutive problem has a solution in a weak sense. The study of the problem is carried out using numerical analysis techniques. A numerical scheme is build to be implemented on a computer in order to obtain numerical results. Finally, we present theoretical results for a steady-state problem and prove existence of a solution under assumptions weaker than in the evolutive case.
Touzani, Rachid
Year:
1994
Publisher:
Lausanne, EPFL | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9660438299179077, "perplexity": 357.12007698737506}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-09/segments/1518891812932.26/warc/CC-MAIN-20180220090216-20180220110216-00631.warc.gz"} |
http://physics.stackexchange.com/questions/68691/rope-wrapped-around-a-pole | # rope wrapped around a pole
I would like to solve this question without using conservation of angular momentum(because of some reason I'll elaborate later).
So imagine that we have a pole with radius $r$ and a ball attached to a rope of length $R$.
Initially the distance between the ball and the attach point is $R$(which means the rope is tight). The initial velocity of the ball is perpendicular to the rope. Now we know $R>r$. At a later time $t$, what is the direction and magnitude of the velocity of the ball?
The reason we cannot use conservation of angular momentum is because I don't assume that the ground is not moving. Instead I assume that the ground is the Earth. So if the rope applies a torque on the Earth, the Earth's angular momentum will increase. I always see people use conservation of angular momentum to solve such a question but not conservation of energy. And if we assume that the ground is not moving, there must be one of them that is not conserved! And I would like to know if the common way of doing it is right or wrong.
However I got stuck at the very beginning... Once I figured out the initial and final energy and momentum, I should be able to solve it. Any help would be much appreciated!
The pole is vertical. And we can assume no gravity. Also I guess friction is important, otherwise the rope can't be wrapped around the pole. However let's assume there is no loss of energy thru friction. There is of course tension on the rope.
IMPORTANT REMARKS: It might look really simple to you at first. But it's actually not that as straightforward as it seems. When we solve this kind of problem in the standard first year physics text, we always assume conservation of angular momentum. However this would imply the violation of conservation of energy if we assume the ground does not move. If we do assume that the ground moves, both angular momentum and energy will not be conserved for the pole(because the system gives angular momentum and energy to the earth). In that case, if we take the limit as mass of the earth goes to infinity, which one is more conserved(It has to be angular momentum, otherwise we would have used conservation of energy to solve this kind of problem in first year physics textbooks. But now I just want to justify it)?
THIS IS NOT A FIRST YEAR PHYSICS TEXTBOOK PROBLEM!
Also although I added the homework tag to this question, it's not an actual homework problem(as you can see from the date I posted it). So please feel free to write down any detail that you think might help explaining your solution. Thanks!
-
Is the pole vertical, horizontal or what? Is there gravity (I guess) and is the rope end attached somehow? Can there be tension on the rope, and is friction important (to keep it wrapped)? – ja72 Jun 26 '13 at 13:39
The pole is vertical. And we can assume no gravity. Also I guess friction is important, otherwise the rope can't be wrapped around the pole. However let's assume there is no loss of energy thru friction. There is of course tension on the rope. Thanks for your questions! – Evariste Jul 26 '13 at 1:17
Is this homework? If so, please use the homework tag. – Ben Crowell Jul 26 '13 at 2:03
@Evariste: as the mass of the earth goes to infinity, which one is more conserved Kinetic energy, as explained in my answer. – Ben Crowell Jul 26 '13 at 23:03
@Evariste The angular momentum of the ball around the pole cannot be constant, since the rope is tangential to the pole, and therefor the force is not axial. As the ball wraps around the pole the rope is pulling backwards and so it is reducing the angular momentum. The energy is conserved, as noted in other comments, since the force is always perpendicular to the velocity. – John M. Cavallo Jul 31 '13 at 0:24
I started this before ja72 posted his solution, but was so far along by the time I saw his that I wanted to contribute it anyway.
This looks like a graduate level mechanics problem, probably without a closed form solution. I would approach it using Lagrangian mechanics with a constraint on the relative motion of the pole and the ball.
Ignoring motion the third dimension (the no-gravity condition), there are 5 degrees of freedom, the movement of the ball, the movement of the pole+earth, and the 'spin' of the pole+earth around the pole. The ball can't 'spin' because of the rope. Choosing the center of mass (CM) frame reduces the number of degrees of freedom by 2.
So what are the degrees of freedom in the CM frame? The separation of the ball and pole, s, the angle that the pair have rotated around the CM, $\theta$, and the angle the pole has spun around its own axis, $\phi$.
The kinetic energy of the system, would be the kinetic energy of the rotation plus the kinetic energy of the spin,
$$T = \frac{m_{red}}{2} (\dot{s}^2 + s^2 \dot\theta^2) + \frac{I}{2}\dot\phi^2$$
Where $m_{red}$ is the reduced mass and $I$ is the moment of inertia of the earth/pole system.
There is also one constraint: relative to the pole, the ball will follow a spiral path into or away from the pole. Since the rope can be wound by rotation and unwound by the spin, the length of the rope is
$$l = r (\theta - \phi)$$
The rope is tangential to pole and goes through the center of the ball, so the length of the rope is related to the separation by
$$s^2 = r^2 + l^2 = r^2 (1 + (\theta - \phi)^2)$$
The Lagrangian would then be the sum of the kinetic energy and the constraint times a multiplier, $\lambda$,
$$\mathcal{L} = \frac{m_{red}}{2} (\dot{s}^2 + s^2 \dot\theta^2) + \frac{I}{2}\dot\phi^2 + \frac\lambda 2 (s^2 - r^2 (1 + (\theta - \phi)^2))$$
Which leads to four equations of motion,
$$\tag{1} m_{red} \frac{\mathrm d}{\mathrm d t}(s^2\dot\theta) = -\lambda r^2 (\theta - \phi)$$ $$\tag{2} I \ddot\phi = \lambda r^2 (\theta - \phi)$$ $$\tag{3} m_{red} \ddot{s} = m_{red} s \dot\theta^2 + \lambda s$$ $$\tag{4} s^2 = r^2 (1+ (\theta - \phi)^2)$$
Notice that, because the sum of equations (1) and (2) is zero, the total angular momentum, $I\dot\phi + m_{red}s^2\dot\theta$ is conserved.
EDIT: To answer Ben Crowell's question, in addition to correcting a sign error in equation (3) and numbering the equations.
First note that from equation (3), $\lambda$ remains finite unless s $\to$ 0. So, from equation (2), as $I \to \infty$, $\ddot\phi \to 0$, and so $\dot\phi$ is constant. It might be interesting to work in a rotating frame, the south pole for instance, but for simplicity, let $\dot\phi = 0$ and $\phi = 0$.
Let $L = m s \dot\theta$, in which case equations (1), (3), and (4) reduce to,
$$\tag{5} \dot{L} = -\lambda r^2 \theta$$ $$\tag{6} m \ddot{s} = \frac{L^2}{m s^3} + \lambda s$$ $$\tag{7} s^2 = r^2(1 + \theta^2)$$
The velocity of the ball has both a radial and tangential component, so the square of the speed is $\dot{s}^2 + s^2 \dot\theta^2$. For it to be constant, the time derivative must be zero. Recasting it in terms of $L$ and taking the time derivative,
$$\tag{8} \dot{s}\ddot{s} - \frac{L^2 \dot{s}}{m^2 s^3} + \frac{L \dot{L}}{m^2 s^2} = 0$$
Multiplying equation (5) by $\frac{L}{m^2 s^2} = \frac{\dot\theta}{m}$ results in
$$\tag{9} \frac{L \dot{L}}{m^2 s^2} = - \frac{\lambda r^2 \theta \dot\theta}{m}$$
Multiplying equation (6) by $\frac{\dot{s}}{m}$ and rearranging the terms,
$$\tag{10} \dot{s} \ddot{s} -\frac{L^2 \dot{s}}{m^2 s^3} = \frac{\lambda s \dot{s}}{m}$$
Finally taking the time derivative of equation (7),
$$\tag{11} s \dot{s} = r^2 \theta \dot\theta$$
Substituting equations (9) and (10) into (8) then using (11) results in:
$$\tag{12} \frac{\lambda s \dot{s}}{m} - \frac{\lambda r^2 \theta \dot\theta}{m} = \frac{\lambda s \dot{s}}{m} - \frac{\lambda s \dot{s}}{m} = 0$$
Or should I have just said yes?
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In the limit where the earth's mass is much larger than that of the ball, do you recover the correct result of constant speed for the ball? – Ben Crowell Jul 26 '13 at 21:58
The speed of the ball is $\dot{r_b}^2 + r_b^2 \dot\theta^2$. Since this is the center of mass frame, the relationship between $r_b$ and $s$ is $r_b = \frac{m_E}{m_b + m_E}$. Plugging this into the equation for the speed of the ball will result in a constant times the same equation that was derived for the case of $m_E \to \infty$. The rest of the derivation, equations (8) to (12) are independent of the mass of the earth, so the speed of the ball is constant in all cases. – John M. Cavallo Jul 31 '13 at 23:57
This answer assumes the limit in which the earth's mass is large compared to the ball's. That may not be what the OP had in mind.
The rope's force on the ball is parallel to the rope. At any given moment, the ball's motion is perpendicular to the force, so the rope does no work on the ball. Therefore the ball's kinetic energy is constant. Because the pole has a finite radius, the force is not directed toward the central axis, so the rope's torque on the ball is nonzero, and the ball's angular momentum is not conserved.
The initial velocity of the ball is perpendicular to the rope. Now we know R>r. At a later time t, what is the direction and magnitude of the velocity of the ball?
The magnitude of the velocity is the same. The direction is perpendicular to the rope.
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I don't think your answer is correct. Sorry but the rope is spiraling in towards the pole. If the rope does no work, how could this happen? – Evariste Jul 26 '13 at 6:29
I don't think the "ball's motion is perpendicular to the force". The ball has both a tangential component and radial component of velocity(because the string's length is decreasing). Thus the rope will do work on the ball. – udiboy1209 Jul 26 '13 at 16:22
The balls motion has to be perpendicular to the rope or the rope would go slack or stretch. The rope is tangential to the pole, so it can change the angular momentum around the ball/(pole+earth) center of mass. – John M. Cavallo Jul 26 '13 at 20:46
An easy way to convince yourself that the ball's motion is perpendicular to the force is to consider a pole whose cross-section is polygonal rather than circular. The circular case then follows from taking the limit of a polygon with a large number of sides to approximate a circle. – Ben Crowell Jul 26 '13 at 21:04
@MikeDunlavey: Geometrically, if you reel in the rope, you're giving the bob a velocity parallel to the rope. Physically it should be pretty clear if you look at what's going on where the rope touches the pole or the channel at the top of the pendulum through which you're drawing in the rope. Drawing a rope through a hole under tension is always going to require mechanical work. – Ben Crowell Jul 26 '13 at 21:57
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You can solve this problem using Newtonian Mechanics, or Lagrangian Mechanics once you constrain the motion of the ball of mass $m$ in a spiral around the pole, with 1 degree of freedom (the wrap angle $\theta$). Initially the rope is horizontal and the ball has coordinates $x_{ball} = R$, $y_{ball} = -r$. I have a coordinate system with z along the pole and x horizontal.
In general the position of the ball relative to the pole is
$$\vec{r}_{ball}^{pole} =\begin{bmatrix} \cos\theta & -\sin\theta & 0 \\ sin\theta & \cos\theta & 0 \\ 0 & 0 & 1 \end{bmatrix} \begin{pmatrix} R-r \theta \\ -r \\ 0 \end{pmatrix}$$
The $-r$ is due to the tangency of the rope with the pole, and $R-r \theta$ is the unwrapped length.
Now recognize that the pole (or the earth) is on frictionless plane with coordinates $x$, $y$ and orientation $\psi$. This adds 3 more degrees of freedom for the positions vectors to be
$$\vec{r}_{pole} = \begin{pmatrix} x \\ y \\ 0 \end{pmatrix}$$ $$\vec{r}_{ball} =\vec{r}_{pole} + \begin{bmatrix} \cos\psi & -\sin\psi & 0 \\ sin\psi & \cos\psi & 0 \\ 0 & 0 & 1 \end{bmatrix} \begin{bmatrix} \cos\theta & -\sin\theta & 0 \\ sin\theta & \cos\theta & 0 \\ 0 & 0 & 1 \end{bmatrix} \begin{pmatrix} R-r \theta \\ -r \\ 0 \end{pmatrix}$$
Now you can differentiate the above in terms of $x$, $y$, $\psi$ and $\theta$ to get your pole and ball velocity vectors and hence the total kinetic energy. You also need to include the rotational energy of the earth to get the total kinetic energy
$$T = \frac{1}{2} M_{earth} v_{earth}^2 + \frac{1}{2} I_{earth} \omega_{earth}^2 + \frac{1}{2} m_{ball} v_{ball}^2$$
Since there is no potential energy (I ignored gravity) the lagrangian is $L=T$.
The four equations used to find $\ddot{x}$, $\ddot{y}$, $\ddot{\psi}$ and $\ddot\theta$ are
$$\frac{\rm{d}}{\rm{d} t} \left( \frac{\partial L}{\partial \dot{x}}\right) - \frac{\partial L}{\partial x} = 0$$ $$\frac{\rm{d}}{\rm{d} t} \left( \frac{\partial L}{\partial \dot{y}}\right) - \frac{\partial L}{\partial y} = 0$$ $$\frac{\rm{d}}{\rm{d} t} \left( \frac{\partial L}{\partial \dot{\psi}}\right) - \frac{\partial L}{\partial \psi} = 0$$ $$\frac{\rm{d}}{\rm{d} t} \left( \frac{\partial L}{\partial \dot{\theta}}\right) - \frac{\partial L}{\partial \theta} = 0$$
I have done this and came up with
$$\ddot{x} = \frac{I_{earth} (\dot\psi+\dot\theta)^2 (R-r\theta)\cos(\psi+\theta)}{I_{earth} \left( 1 + \frac{m_{earth}}{m_{ball}} \right) + m_{earth} r^2}$$ $$\ddot{y} = \frac{I_{earth} (\dot\psi+\dot\theta)^2 (R-r\theta)\sin(\psi+\theta)}{I_{earth} \left( 1 + \frac{m_{earth}}{m_{ball}} \right) + m_{earth} r^2}$$ $$\ddot{\psi} = \frac{m_{earth} r (\dot\psi+\dot\theta)^2 (R-r\theta)}{I_{earth} \left( 1 + \frac{m_{earth}}{m_{ball}} \right) + m_{earth} r^2}$$ $$\ddot{\theta} = \frac{r (\dot\theta^2-\dot\psi^2)}{R-r \theta} - \frac{m_{earth} r (\dot\psi+\dot\theta)^2 (R-r\theta)}{I_{earth} \left( 1 + \frac{m_{earth}}{m_{ball}} \right) + m_{earth} r^2}$$
Notice that when earth is inertial then $\ddot{x}=0$, $\ddot{y}=0$, $\ddot{\psi}=0$ and $\ddot{\theta}=\frac{r (\dot\theta^2-\dot\psi^2)}{R-r \theta}$.
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Have you considered the rotation of the earth(by rotation I mean the already present $\omega$ it has of about $\frac{2\pi}{24} \frac{rad}{hr}$). If there is no gravity the effects due to the rotation(Coriolis force for eg.) can't be ignored. – udiboy1209 Jul 26 '13 at 16:28
Do you recover the correct result of constant velocity for the ball in the limit $m_{earth}\gg m_{ball}$? – Ben Crowell Jul 26 '13 at 22:00
I really consider a pole attached on a large mass moving on a constant velocity. This way there is an interaction between the ball motion and the base motion. – ja72 Jul 29 '13 at 1:24
@BenCrowell the only way the velocity is constant is if the wrapping is exactly counteracted by the base rotation and $\dot\psi =-\dot\theta$ and thus $\ddot{\theta}=0$. – ja72 Jul 29 '13 at 1:26
Assume the Earth isn't rotating at the start of the experiment. I assume the rope is wrapping itself around the pole. This is going to give an angular velocity to the Earth. Now, the Earth has a huge moment of inertia $I_E$. Suppose the angular velocity of the Earth at time $t$ during the experiment is $\omega_E$. Then we have angular momentum and energy of the Earth are $$L_E = I_E \omega_E$$ and $$E_E = \frac{1}{2}I_E \omega_E^2\, .$$
There will also be an initial angular momentum $L_{B,0}$ and energy $E_{B,0}$ for the ball, and an angular momentum $L_{B,t}$ and energy $E_{B,t}$ for the ball at time $t$. Since everything is conserved, we have $$L_{B,0} = L_{B,t} + L_E$$ and $$E_{B,0} = E_{B,t} + E_E\,.$$ Since $I_E$ is very large and $\omega_E$ is very small, either $L_E$ is of the right magnitude to cancel out the change in angular momentum of the ball and $E_E$ is negligible, or $E_E$ is of the right magnitude to cancel out the change in energy of the ball and $L_E$ is huge. IF $L_E$ is huge, angular momentum can't be conserved, so clearly, we want the first alternative, and we find that the energy of the ball is (very nearly) conserved, and its angular momentum is not.
Now, let's deal with the case where the Earth is rotating. Before the experiment, let it have angular velocity $\vec{\omega}_E$. During the experiment, let it have angular velocity $\vec{\omega}_E + \vec{\omega}_\Delta$. Then, the change in angular momentum of the Earth is $$L = I_E \omega_\Delta$$ and the change in energy is $$E = \frac{1}{2} I_E\left( (\vec{\omega_E} + \vec{\omega_\Delta})^2 - \vec{\omega_E}^2\right) \approx I_E \, \vec{\omega_E} \cdot \vec{\omega_\Delta}\, .$$
These have to cancel out the change in angular velocity and change of energy of the ball. Now, $L_B \approx I_B\omega_B$ and $E_B \approx \frac{1}{2} I_B\omega_B^2$. (These equations are approximate because the path of the ball is a spiral, not a circle.) So we have $E_E/|L_E| \approx \omega_E$ and $E_B/|L_B| \approx \frac{1}{2} \omega_B$.
Now, since $\vec{\omega}_E$ is small in comparison with the angular velocity of the ball, if we let the change in the Earth's angular momentum cancel out the change in the ball's angular momentum, we find that the energy of the ball is (nearly) conserved. Note that this wouldn't be true if the ball were revolving at around the same angular velocity as the Earth, in which case the Coriolis effect would be non-neglible. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9818035364151001, "perplexity": 194.83368926584768}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-23/segments/1405997892806.35/warc/CC-MAIN-20140722025812-00119-ip-10-33-131-23.ec2.internal.warc.gz"} |
https://www.arxiv-vanity.com/papers/1210.8411/ | # Hall, Seebeck, and Nernst Coefficients of Underdoped HgBa2CuO4+δ : Fermi-Surface Reconstruction in an Archetypal Cuprate Superconductor
February 17, 2021
###### Abstract
Charge density-wave order has been observed in cuprate superconductors whose crystal structure breaks the square symmetry of the CuO planes, such as orthorhombic YBaCuO (YBCO), but not so far in cuprates that preserve that symmetry, such as tetragonal HgBaCuO (Hg1201). We have measured the Hall (), Seebeck (), and Nernst () coefficients of underdoped Hg1201 in magnetic fields large enough to suppress superconductivity. The high-field and are found to drop with decreasing temperature and become negative, as also observed in YBCO at comparable doping. In YBCO, the negative and are signatures of a small electron pocket caused by Fermi-surface reconstruction, attributed to charge density-wave modulations observed in the same range of doping and temperature. We deduce that a similar Fermi-surface reconstruction takes place in Hg1201, evidence that density-wave order exists in this material. A striking similarity is also found in the normal-state Nernst coefficient , further supporting this interpretation. Given the model nature of Hg1201, Fermi-surface reconstruction appears to be common to all hole-doped cuprates, suggesting that density-wave order is a fundamental property of these materials.
###### pacs:
There is a growing body of evidence that competing ordered states shape the phase diagram of cuprates and the identification of those states is currently a central challenge of high-temperature superconductivity. In the LaCuO-based cuprates, whose maximal does not exceed 40 K, the existence of unidirectional density-wave order involving spin and charge modulations, known as stripe order Kivelson et al. (2003); Vojta (2009), is well established, as in LaNdSrCuO (Nd-LSCO) Ichikawa et al. (2000) and LaEuSrCuO (Eu-LSCO) Fink et al. (2011) for instance. This stripe order causes a reconstruction of the Fermi surface Cyr-Choinière et al. (2009); Daou et al. (2009); Chang et al. (2010); Laliberté et al. (2011), and may be responsible for the low . The observation of a small electron pocket in the Fermi surface of underdoped YBCO Doiron-Leyraud et al. (2007); LeBoeuf et al. (2007), a material with a high maximal of 93 K, showed that its Fermi surface also undergoes a reconstruction at low temperature Chakravarty (2008); Taillefer (2009). Comparative measurements of the Seebeck coefficient in YBCO and Eu-LSCO revealed a detailed similarity Chang et al. (2010); Laliberté et al. (2011), suggesting that Fermi-surface reconstruction (FSR) in YBCO is caused by some form of stripe order.
Charge density-wave modulations were recently detected in YBCO, via high-field nuclear magnetic resonance (NMR) Wu et al. (2011) and X-ray scattering Ghiringhelli et al. (2012); Chang et al. (2012a); Achkar et al. (2012); Blackburn et al. (2013) measurements, in the range of temperature and doping where FSR occurs LeBoeuf et al. (2011); Laliberté et al. (2011). Although the detailed structure of these modulations remains to be clarified, there is little doubt that they are responsible for the FSR in YBCO.
The fundamental question, then, is whether such charge modulations are a generic property of cuprates. Because both the low-temperature tetragonal (LTT) structure of Eu-LSCO and the orthorhombic structure of YBCO distort the square CuO planes and impose a preferred direction, charge modulations are perhaps triggered or stabilized by these particular forms of unidirectional distortion. To answer that question we need to examine a cuprate material with square, undistorted CuO planes. The model material for this is Hg1201, a tetragonal cuprate with the highest maximal of all single-layer cuprates (97 K) Zhao et al. (2006); Barišić et al. (2008), in which no charge or spin modulations have yet been reported. In this Letter, we present measurements of the Hall, Seebeck, and Nernst coefficients in underdoped Hg1201 which reveal a FSR very similar to that seen in YBCO, demonstrating that some form of density-wave modulation is present in Hg1201. This is strong evidence that charge density-wave modulations, as seen in YBCO, are a universal and fundamental property of underdoped cuprates. They compete with superconductivity and might also play a role in both the pairing mechanism and the anomalous scattering in these high- superconductors Taillefer (2010).
Methods. – Two nominally identical high-purity single crystals of underdoped Hg1201 were measured (samples A and B), with K, prepared as described in refs. Zhao et al., 2006 and Barišić et al., 2008. According to the relationship for Hg1201 established in ref. Yamamoto et al., 2000, our samples have a doping . We measured the Hall (), Seebeck (), and Nernst () coefficients, where is the transverse resistivity, and () is the longitudinal (transverse) voltage in the presence of a longitudinal temperature difference . For all measurements the magnetic field was applied perpendicular to the CuO planes and the current (charge or heat) was within the plane. Hall measurements were performed in pulsed magnetic fields at the LNCMI in Toulouse up to T, as described in ref. LeBoeuf et al., 2007. The Seebeck coefficient was measured on sample A, as described in ref. Laliberté et al., 2011, up to 28 T at the LNCMI in Grenoble and up to 45 T at the NHMFL in Tallahassee. The Nernst coefficient was measured on sample A at Sherbrooke in a field of T, as described in ref. Daou et al., 2010.
Negative Hall and Seebeck coefficients. – In Fig. 1a, the Hall coefficient is plotted as a function of magnetic field up to 68 T, for different temperatures down to K. All isotherms of sample A (B) saturate at high fields, beyond T (68 T), except (including) at K. In Fig. 1b, the high-field value of is plotted versus temperature. In Fig. 2a and 2b, we show the corresponding Seebeck data as a function of magnetic field and temperature, respectively. As expected for a hole-doped material, both and are positive at high temperature. However, with decreasing temperature they both start to fall below about K to eventually become negative below K. This is our central finding: the low-temperature normal-state of Hg1201 has negative Hall and Seebeck coefficients.
In Fig. 1b and 2b, comparison with corresponding data in underdoped YBCO, with K (Laliberté et al. (2011); LeBoeuf et al. (2007), reveals a striking similarity between the two cuprates. In YBCO, there is compelling evidence that the negative and at low temperature come from a small electron Fermi surface. This evidence includes quantum oscillations Doiron-Leyraud et al. (2007); Jaudet et al. (2008) with a frequency and mass which, at this doping, account precisely for the normal-state Seebeck coefficient at , whereby , given that is negative Chang et al. (2010); Laliberté et al. (2011). By analogy, we deduce that the Fermi surface of underdoped Hg1201 at low temperature also has an electron pocket. This implies that it is reconstructed relative to its topology at high doping, where it is expected to be a single large hole-like cylinder, as observed in the single-layer tetragonal cuprate TlBaCuO at Mackenzie et al. (1996); Platé et al. (2005); Vignolle et al. (2008). In other words, the FSR in Hg1201 sets in below a critical doping located somewhere between and , as is the case for YBCO LeBoeuf et al. (2011); Laliberté et al. (2011), Eu-LSCO Laliberté et al. (2011), and Nd-LSCO Daou et al. (2009); Cyr-Choinière et al. (2009); Taillefer (2009, 2010). This quantum critical point at in the normal-state phase diagram of Hg1201 marks the onset of some density-wave order that breaks the translational symmetry of the lattice.
Our data also show that a transformation occurs upon cooling at fixed , albeit smoothly, with no sign of a sharp transition. The onset of FSR may be defined as the temperature at which is maximal, although clearly starts to deviate downward from its high-temperature behavior well above , at a temperature labeled LeBoeuf et al. (2011). Our Hall data on Hg1201 sample B yield approximately K and K. In YBCO, K and K at LeBoeuf et al. (2011). In Fig. 3, , and the Hall effect sign change temperature in YBCO and Hg1201 are plotted on their respective phase diagrams.
Given that the tetragonal structure of underdoped Hg1201 has no unidirectional character, our findings show that density-wave order is a generic tendency of the square CuO plane, and therefore a phenomenon intrinsic to the physics of cuprates. However, the precise nature of the density-wave order responsible for FSR in Hg1201 remains to be elucidated, e.g., by X-ray scattering or NMR studies.
In YBCO at and 0.12, a modulation of the charge density was detected in the CuO planes by NMR measurements at high fields Wu et al. (2011). It was inferred to be unidirectional, with a period of , where is the lattice spacing, along the -axis of the orthorhombic lattice for the ortho-II structure at (the pattern could not be determined for the ortho-VIII structure at ). Note, however, that an additional modulation along the -axis cannot be excluded. In Fig. 1b, we reproduce the NMR data at and see that the onset of charge order, at K, coincides approximately with the downturn in for a similar doping (). The same may be said of . Moreover, an increase in doping to causes a parallel increase in both Wu et al. (2011) and LeBoeuf et al. (2011) (see Fig. 3a). This is strong evidence that the FSR in YBCO is caused by this charge density-wave order Doiron-Leyraud and Taillefer (2012). In Eu-LSCO, unidirectional stripe-like charge order with a period was detected by X-ray scattering Fink et al. (2009), with K at and K at Fink et al. (2011), and linked to a drop in Cyr-Choinière et al. (2009); Taillefer (2009) and in Chang et al. (2010); Laliberté et al. (2011), again showing that charge order is causing the FSR Doiron-Leyraud and Taillefer (2012).
Recent X-ray studies of YBCO in zero and low magnetic fields up to 17 T, however, have discovered incommensurate charge modulations (which may not be static) along both the and axes, with a period of Ghiringhelli et al. (2012); Chang et al. (2012a); Achkar et al. (2012); Blackburn et al. (2013). As seen in Fig. 3, the onset of the X-ray scattering intensity appears to match , although these are gradual crossovers and there is no sharp anomaly in either the X-ray data or the transport data. Their relation to the charge order seen by NMR at high field below remains to be understood. Recent high-field sound velocity measurements on YBCO at detected the charge order below , and showed that it must be a bi-directional charge-density-wave (and not domains of two uniaxial density waves) LeBoeuf et al. (2013). So the case of YBCO would appear to differ from the unidirectional charge-stripe scenario observed in the LaCuO-based materials. But more work is needed to establish the differences and clarify whether these are fundamental. It has been proposed that a bidirectional charge order is part of the explanation for the reconstructed Fermi surface of underdoped YBCO Harrison and Sebastian (2011). Given the striking similarity in the transport properties of YBCO and Hg1201, it is very likely that they host a similar form of charge order.
In YBCO, charge order competes with superconductivity Ghiringhelli et al. (2012); Chang et al. (2012a); Achkar et al. (2012). This is why falls when FSR sets in LeBoeuf et al. (2011), below (Fig. 3). The competition is strikingly manifest in recent measurements of the upper critical field in YBCO Grissonnanche et al. (2013), which showed to have a local minimum where charge order exists. Although less pronounced, a similar non-monotonic drop with underdoping is observed in the vs curve, for both YBCO Liang et al. (2006) and Hg1201 Yamamoto et al. (2000) (see Fig. 3). Certain features of the lattice structure may play a role in stabilizing the charge order, strengthening it more in some materials (e.g. with the LTT structure). This would impact on the competition between charge order and superconductivity, suppressing more effectively in Eu-LSCO (maximal K), where charge order exists at , than in YBCO (where a magnetic field is needed to fully stabilize charge order Wu et al. (2011); LeBoeuf et al. (2013)) or Hg1201 (maximal K).
Negative Nernst effect. – In underdoped YBCO, the Nernst coefficient Chang et al. (2010); Daou et al. (2010) also provides hints of FSR. As seen in Fig. 4, the Nernst coefficient of YBCO at is small and positive at high temperature, and it drops to large and negative values at low temperatures. (Note that unlike the Hall and Seebeck coefficients, the sign of the Nernst coefficient is not governed directly by the sign of the dominant charge carriers.) This drop was shown to occur at the pseudogap temperature Daou et al. (2010), at which the in-plane resistivity deviates from its linear temperature dependence at high temperature. Close to , a positive signal due to superconductivity appears Chang et al. (2012b), but application of a large magnetic field suppresses this signal, revealing that the smooth drop in the normal-state continues monotonically down to Chang et al. (2010, 2011). The value of at is precisely that expected of the electron Fermi surface Laliberté et al. (2011), given its frequency, mass and mobility measured via quantum oscillations Doiron-Leyraud et al. (2007); Jaudet et al. (2008). In other words, the large negative Nernst coefficient in YBCO at low temperature is a consequence of FSR.
As shown in Fig. 4, the Nernst coefficient of Hg1201 is essentially identical to that of YBCO. When plotted versus , has the exact same temperature dependence in both materials. ( in Hg1201 is defined as in YBCO Barišić et al. (2008); Li et al. (2008, 2011).) We infer that the large negative in Hg1201 is also a manifestation of FSR. (Note that in YBCO is anisotropic in the plane Daou et al. (2010); Chang et al. (2011). In tetragonal Hg1201, where no such anisotropy is expected, the magnitude of lies between the and of YBCO.)
Summary and outlook. – Our high-field measurements of Hall and Seebeck coefficients in the tetragonal single-layer cuprate Hg1201 reveal that its normal-state Fermi surface undergoes a reconstruction in the underdoped regime at low temperature, which produces an electron pocket. This is compelling evidence for the presence of a density-wave order that breaks translational symmetry. The remarkable similarity of these transport properties with those of the orthorhombic bi-layer cuprate YBCO strongly suggest that the charge density-wave order observed in YBCO is also responsible for the FSR in Hg1201, and is thus a generic property of hole-doped cuprates. The presence of charge density-wave order in the midst of the phase diagram of cuprate superconductors raises some fundamental questions. Is the enigmatic pseudogap phase a high-temperature precursor of the charge order at low temperature? Is the quantum critical point for the onset of charge order responsible for the anomalous properties of the normal state, such as the linear- resistivity? Are fluctuations of the charge order involved in pairing? Our findings in Hg1201 broaden the scope for exploring these questions by adding a clean archetypal cuprate to the list of materials that exhibit all the key properties of hole-doped cuprates, including superconductivity with a high , a pseudogap phase with magnetic order Li et al. (2008, 2011, 2012) (Fig. 3), and Fermi-surface reconstruction from charge density-wave order.
We thank the NHMFL for access to their 45 T hybrid magnet in Tallahassee. The work at Sherbrooke was supported by a Canada Research Chair, CIFAR, NSERC, CFI, and FQRNT. The work at the LNCMI was supported by PF7 EuroMagNET II and the ANR Superfield. The work at the University of Minnesota (crystal growth, annealing, characterization and contacting of samples) was supported by the US Department of Energy, Office of Basic Energy Sciences. J. C. was supported by the Swiss National Science Foundation.
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http://mathhelpforum.com/statistics/186895-random-choice-numbers-series-probability-numbers-equal-print.html | # Random choice of numbers from series, probability the numbers are equal?
• August 29th 2011, 01:13 AM
downthesun01
Random choice of numbers from series, probability the numbers are equal?
A number X is chosen at random from the series 2,5,8.. and another number Y is chosen at random from the series 3,7,11... Each series has 100 terms. Find P[X=Y]
They way I solved this is as following.
I know that each series has 100 terms, so I can find the final term in each series.
Let $S_1=2,5,8..$and let $S_2=3,7,11..$
Therefore, the final term of $S_1$ should be 302 and the final term of $S_2$ should be 403.
Now I look look for the terms that both series share. I know that both series can't share any terms >302.
So I have
{11,23,35,47,59,71,83,95,107,119,131,143,155,167,1 79,191,203,215,227,239,251,263,275,287,299}
Or 25 terms shared between the two series.
Therefore, the probability of $P[X=Y]=\frac{25}{10,000}=\frac{1}{400}$
My question is whether there's an easier/faster way to solve this problem other than writing out and summing the number of terms? As you can see, it's not too bad if the series are rather short, but I'm interested in how I would approach this problem if each series were huge.
Thanks
• August 29th 2011, 03:18 AM
The first time the numbers of both sequences are equal is for the 4th term of $S_1$
That's every 4th term of $S_1$
The values of $S_1$ are smaller per position than $S_2$
The number of equal values is $\frac{100}{4}$ | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 10, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.932428240776062, "perplexity": 458.31063939434995}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-11/segments/1424936463108.89/warc/CC-MAIN-20150226074103-00070-ip-10-28-5-156.ec2.internal.warc.gz"} |
https://worldbuilding.stackexchange.com/questions/58732/what-could-make-an-area-of-land-be-accessible-only-at-certain-times-of-the-year/59000 | # What could make an area of land be accessible only at certain times of the year?
I've looked around here a bit, but I haven't managed to find a post that really answers my question (though if there is one, please let me know).
I'm trying to write a story where the two main characters decide to stow away with some travellers who come through their village annually, and I want the travellers to realise that these kids are there when it's too late to turn around and take them back, so the travellers have no choice but to go about their usual annual route before dropping the kids back at the same time next year.
I would like this to be due to some geographical or even season-related reasons and to have the region where the village is located only easily accessible perhaps two or three times a year. So I'm not looking for something like the tides making a certain island only accessible once a day, since that's far too frequent (though it is of course fine if it's a tidal event that somehow only happens a few times a year). Let's also assume that the years and seasons are basically the same as here on Earth.
So, is this possible? And if so, what kind of environment would make it possible for this region to only be easily accessible two or three times a year? (I don't mind if the amount of times the region is accessible in a year is more than two or three, but I'd definitely like it to be no more than four or five, if possible.)
I would also appreciate it if an answer for both how long the region remains accessible (preferably a week or so), and how long it takes for whatever occurs to make the region inaccessible again is given, too.
As a note: It doesn't have to be completely inaccessible for the other parts of the year. Just difficult enough that a band of travellers who are rather slow moving with some carriages and heavy luggage don't think it's worth trying to enter the region outside of those few times a year.
EDIT AFTER CHOOSING AN ANSWER: Thank you everyone who has answered this so far! I have waited about a day and chosen Zxyrra's answer as the best because it's got the most up-votes and for the most part I think it's one of the most useful. Although, there are a number of answers that are similar and I'm thankful to everyone who gave suggestions :)
• A glacier comes to mind: in summer it melts opening a pass through the mountain. Once it freezrs again you need to wait for the next year – algiogia Oct 17 '16 at 10:42
• @algiogia i'm not sure that's how glaciers work, they stay frozen and flow like a river, but slowly. – Whinja Oct 17 '16 at 11:08
• Interesting that so far all of the answers use water - is there nothing else dynamic & cyclical enough? – plast1k Oct 17 '16 at 12:09
• How old are the kids? (ie, could they travel back on their own if everything was well, can they work a bit) and how long after the departure are they discovered? – Matthieu M. Oct 17 '16 at 13:38
• @Whinja: Not necessarily a glacier, but snowpack would definitely work. (A certain scene from the movie Seven Brides For Seven Brothers comes to mind...) – Mason Wheeler Oct 17 '16 at 18:55
There are many ways to change access to an area throughout the year:
Seasonal Extremes:
Typically, the further from a major body of water a location is, the hotter the summers are and the colder the winters are. Proximity to a lot of water sort of averages the seasons' temperatures together as long as you are not close to a pole or the equator. If you have a location in the center of a massive continent that is neither close to the pole or close to the equator, then the summer months would make travel extremely hot - up to deadly, desert temperatures. In the winter months, the snow, ice, and cold would also be extreme, leaving a few weeks in the spring and a few weeks in the autumn to travel to and away from this location.
Ice Needed:
You could make your location similar to an island in the Bering Sea. During the summer months, the sea is liquid. Maybe in your world, it is full of creatures that prevent sailing, or reliable ships that cross this area are expensive. In the winter, the entire Strait freezes, at which point your characters could buy metal spikes for their wagon, or hire a dog team, to cross the new bridge of sea ice to the desired island or northern continent. This would leave several months for travel, but for the majority of the year this route would not work.
Water Needed:
The opposite of the above. If an area up north is frozen for much of the year, but the ice isn't safe to cross, maybe it thaws for several weeks allowing passage.
King Tide:
About once yearly, the alignment of the sun, moon, and Earth produces what's known as a king tide - in which some areas see extremely high tides while others see extremely low. You could use either the high tide or the low tide during this event to access a location:
Low tide - imagine the only route to your town is through the mountains, and the only route through these mountains is a natural pass that looks like this. Now, imagine that this borders the ocean, and that the pass is actually a small saltwater inlet. During all other times of the year, this arch is completely submerged, but, when your planet, moon, and star align perfectly, people use the pass for travel and commerce for several hours. A stretch, yes, but unique.
High tide - finally, your location could be on an island with extremely high cliffs such as these if not much, much taller. Only once during the year, when the planet, moon, and star align, does the tide rise up and allow ships to do business for a few hours.
• High tide, traditionally, lets water clear shoals, as opposed to reaching docks. Making docks that dip another few feet down isn't hard: clearing shoals is. – Yakk Oct 17 '16 at 13:18
• "Proximity to a lot of water sort of averages the seasons' temperatures together as long as you are not close to a pole or the equator." As a Minnesotan, I'm hesitant to agree with this. – schil227 Oct 17 '16 at 17:32
• @schil227 However you are also relatively far north which has climate impacts of its own – Zxyrra Oct 17 '16 at 17:46
• For the first example, think of the Appalachian Trail on the US east coast. It runs from Georgia to Maine, and if you're going to thru-hike it from south to north there is only a small window of time in which you can start if you're going to avoid getting caught up to by bad weather. If you miss that window you would probably be fine hiking for a long time, but you would be virtually assured of bad weather catching you before you finish. Just make the weather as extreme as you like to suit your story. – Jeff Oct 18 '16 at 17:33
• The Great Lakes do moderate the temperature of at least some coastal parts of Minnesota, AFAIK. That doesn't mean it's nice - just that it would be even worse otherwise. (Interior Siberia is significantly worse climatically, though it's also on a larger continent.) OTOH, some other parts of the Midwest get hit by a "lake effect" that means more snow because of the Great Lakes. – cometaryorbit Oct 19 '16 at 5:07
Winter
Harsh winters came to mind first being from North America. The best part about winter is that it can either enable or prevent travel to a certain location.
A. If your village is separated from the outside world by a mountain pass big enough to have snow caps in the summer, you can bet anything it would be suicide to attempt traversing during the winter months (see Donner Pass & the Donner Party).
B. Areas up near the arctic are only available to modern trucks when the sea water, large rivers, lakes, and just the ground itself freeze solid, forming ice roads. Obviously You could raft or kayak across but if you have enough supplies or people, the expanse is large enough or the terrain perforated enough, then you would need a caravan and the path to be frozen.
Deserts
If you need to cross a vast expanse of desert, you'd best do it if you know you can carry enough water or get some along the way. Desert areas can have ephemeral rivers, which only flow when there are significant rains. You have a ton of flexiblity here. There are examples in Australia that only flow for a week when they get hit by just the right rogue monsoon, which may take years or decades to happen. You can also have semi-predictable wet and dry seasons. Others might flow seasonsly and for a bit longer as snow melts from near by mountains during the spring months.
• Keep in mind that once a pass becomes important enough, it will get kept open year-round. (Donner Pass is an example of this, with both I-80 and the railroad lines running across it...) – Shalvenay Oct 17 '16 at 11:43
• @Shalvenay: But we're not talking modern tech levels here, are we? (If so, we just put the kids on a plane back home :-)) Though traversing the Sierra in winter is suicide only if you're woefully unprepared to deal with winter. See e.g. the story of Snowshoe Thompson, who spent many winters carrying mail across the Sierra a bit south of Donner Pass. – jamesqf Oct 17 '16 at 17:03
• @jamesqf Sure, but I'd classify a band of traders/travelers who were weren't planning on roughing it in the first place with what OP states as slow carriages, luggage, and a few 8 year old tag-alongs to be "woefully unprepared" enough to avoid the risk. – plast1k Oct 17 '16 at 17:29
• @plast1k: But the OP says the travellers do the trip annually, so they should be prepared for a heavy early snowfall (as the Donner Party wasn't). Of course, the fact that they could, if necessary, make it through the snow-covered pass doesn't mean they want to go back (with all the financial loss &c that would incur) just to take a couple of bratty kids back home. So they maybe send a letter via the local Snowshoe Thompson: "Sorry, your kids stowed away with us. We'll drop them off next year." – jamesqf Oct 17 '16 at 22:10
• @jamesqf Good point - and sounds like the making of a good story :) – plast1k Oct 17 '16 at 22:26
Disease. Specifically insect-borne disease. The rainy season arrives, the lowland swamps have a population explosion of mosquitoes, midges, tsetse flies or the equivalent. These insects carry some nasty disease to which humans (or their domestic animals) are susceptible. Fatal or just debilitating is up to you. Maybe not fatal but with a side effect such as horrible smallpox type scarring, or deafness/blindness or impotence. So everyone just avoids the lowlands at 'fever times'.
You can have more than one rainy season a year - for instance, Kenya has 'long rains' and 'short rains'Kenya climate.
The travellers would also know that just as they are heading south to avoid the lowland swamps, the kids' community will be heading north to also put some distance between them and the insects.
There is a small town Verhneimbatsk - You can see it on the map. I think, since 17 century this town was trading outposts - natives (called kets) were trading furs with Russian merchants from city of Krasnoyarsk.
There are only 3 reliable ways to get to this town -
1. by air, postal helicopter 2 times per week,
2. by Yenisei river, using boats from middle of May to middle of October.
3. by Yenisei river, using snowmobile or sledges with dogs from the end of October to end to April (but using dog sledges can be quite dangerous and hard for trade).
And, probably not very reliable way, use really big team of lumberjacks to make road through taiga forest.
On the second half of october the winter starts, and river is covered in ice in few days.
So, the situation can be like this (i assume it is pre XX century level of tech) - in the middle of October, traders came by boat to this city, exchange wares for furs, than they sail in hurry to the next town, because river is covering in ice. All travelers were busy by setting sails, using sticks and paddles to repel ice from boat. And, in this hurry, they were unable to see, that few children managed to hide between sacks of goods.
UPD: also it is worth notice, that end of September is usually very rainy, and river surface is raised to ~ 1 meter. Maybe there is a lot of stones on the bottom of the river, and they can break the boat. And, with elevated river surface after rains, sailing is more save.
UPD2. Answer for @Yakk's question: The weather can be quite unstable - the ice can start appearing on every day from 5th to 20th of October, and usually it takes few days for river to be covered in ice. The mecrhants was not aware of the exact departure time. By careful weather observation, everyone knows, that if there was 3 days in a row with strong wind from North, than ice will start appearing, but if there was only 2 days in row - no ice. And merchants used this knowledge to plan departure.
Why i think it was acceptable risk - The current speed is about 8km/hour. And merchants were travelling down the stream. So, if they were acting properly, they can easily travel more than 300 km until river is covered in ice, it is enough. And, in 300 km there can be a major town, where they can trade goods too and pass the winter.
• If your departure is tight with the start of winter, even if turning around is possible it will not be worth the risk of being stranded. – Yakk Oct 17 '16 at 13:19
• Excellent that you mentioned a specific existing town that is actually close enough to what OP wants to merit further research. – Mad Physicist Oct 18 '16 at 13:38
I really like the animals idea, and in a similar vein the passage of an area could be restricted by plants.
There are a myriad of real-world poisonous plants that can cause irritation, pain or even death just by humans coming into contact with their leaves.
It would not be a stretch to believe that one of these plants blooms at certain times of the year, perhaps within a forest that can only be crossed during winter/autumn when all of the leaves have died. Then when spring comes around, the forest becomes inaccessible again.
Of course, having a forest that makes a village entirely inaccessible for half of the year is unlikely, so perhaps it just makes it extremely inconvenient for the two villagers to return home.
Another reason not to return could be due to economics.
If the travelers cannot afford to travel back to the village, as they don't have enough food to account for the extra time spent heading back, or have perishable goods to trade at their destination, they may decide that it would cost more to take the villagers back than it would to let the two stowaways stay with them. Just because the travelers can physically head back to the village, doesn't mean they would be willing to.
If the only requirement is that the travelers cannot just send them back on their own, as they would refuse to escort them back, then this allows a greater number of reasons for them being unable to travel back alone until the larger group returns to the village. This could be anything from highwaymen that target smaller groups of people to animals that only ignore the larger groups of humans.
### Spring Floods
As the snow in the mountains and hills melts, small creeks become raging rivers. Sure, one could camp out until the waters calm down, but the caravan might not have enough food to wait that long.
### Water Hole Capacity
In a dry area, the caravan uses water holes which take some time to replenish after a large group went through and took all the water. So a caravan can never turn back, only go forward. (Of course that would mean two different caravans would be disaster for both.)
Either the land is surrounded by water and swamp for much of the year but it dries out enough to cross in summer, or it's surrounded by water all year but it freezes over enough to cross in winter. Take your pick.
• Man might invent means to cross water and - for lack of a better word - call it ship. – Ghanima Oct 17 '16 at 11:00
• @Ghanima But according to the question it doesn't have to be completely inaccessible, just inaccessible by carriage. – Mike Scott Oct 17 '16 at 11:03
• Sure, but looking at the history of mankind open water is not exactly the kind of thing to stop us. People crossed the pacific at stone age technology level. Granted they would have to switch carriages for rafts and skiffs but it is not a real show stopper. If it is just water they will think of crossing it and manage to do so. – Ghanima Oct 17 '16 at 11:13
• This is a pragmatic answer. Once the surrounding area becomes swampy, nothing gets through it without considerable effort. – Tony Ennis Oct 17 '16 at 12:12
• @Ghanima Yakutsk, Russia is a real-world example of this: en.wikipedia.org/wiki/Yakutsk#Transportation - in the spring and autumn the Lena River is neither frozen enough for land transport to cross, nor free enough of loose ice for boats to cross safely. With sufficient technology anything is possible, of course - but I wouldn't count on a pre-industrial civilisation being able to find a solution. – gasman Oct 17 '16 at 20:32
As Zxyrra stated in their answer, there are many ways to build an inaccessible area. Here's just another idea I haven't seen mentioned yet.
Animals
You could have your piece of land be inhabited by dangerous predators. Navigating through the area without encountering these predators may be possible but will become more difficult the larger the traveling group, especially if also traveling with wagons.
In winter, these creatures go into hibernation, allowing for a safe passage.
• Or the place is on the annual migration path of swarms of something like fire ants. – Anton Sherwood Oct 18 '16 at 6:52
• Army ants. In this case, hypothetical monster driver ants which migrate "there and back" between two regions. en.wikipedia.org/wiki/Dorylus – RonJohn May 17 '17 at 2:12
## Mountain pass
It's reasonable to have places only reachable through a single mountain pass.
It's reasonable for that pass to be traversable only part of the year.
For a real life example, maybe it's illustrative to look at the remote Georgian region of Tusheti, which is still currently accessible only for part of the year unless you use a helicopter - there's a single road leading to it, it leads over a 2900m / 9300ft pass, and the road is not considered traversable in winter.
From the pictures e.g. http://unusualplaces.org/one-of-the-most-treacherous-roads-in-georgia-the-road-to-tusheti/ it seems rather obvious that if it was snowed over, waiting a few months would seem a reasonable option.
• Also the north rim of the grand canyon is only accessible May through November as snow makes the roads impassible. – cybernard Apr 19 '17 at 22:27
The 'Pitch Black' story line comes to mind here -
A total eclipse allows creatures dwelling underground to surface and kill things, and soon as the sun comes up, they go back underground. You may be able to say the equator + surrounding x miles is the only section of the world that experiences the eclipse, making that region completely impassable for all but the baldest of muscle men. EDIT: They don't come out at night because there are multiple suns, so it never gets completely dark.
• Why don't they do this at night? It seems quite implausible even by movie standards. – John Dallman Oct 17 '16 at 16:04
• @JohnDallman I added an edit to the spoiler box – MooseLucifer Oct 17 '16 at 16:05
Frame Challenge
I'm trying to write a story where the two main characters decide to stow away with some travelers who come through their village annually, and I want the travelers to realize that these kids are there when it's too late to turn around and take them back, so the travelers have no choice but to go about their usual annual route before dropping the kids back at the same time next year.
Why is it the travelers' responsibility to escort those kids back?
If the kids manage to stay hidden for a couple days, I would be surprised to see the travelers going out of their way to get them back and get going again. Note that for each day the kids are hidden, the travelers would have to add two days to their travel, which might derail many plans and arrangements made.
Imagine, for example, that they have to catch a weekly or bi-weekly ferry across a great lake: be one day late, and you have lost a full week (or two). And this just compounds.
Since your group of travelers come every year, I expect that they have a rather set journey plan, and delaying it might significantly affect them. There may be events along their road that they are counting on (fairs, ...) and missing them would cost them money, maybe a lot of money.
On the other hand, keeping the kids and having them work for their food does not incur any delay, and is still morally "fair".
Note: There is also a "simple" way to increase the delay (and cost). If the kids are discovered rather quickly, but argue that they are going to the next town over to their uncle's house, the travelers might find it more convenient to just follow on. Of course, once they arrive in the next town after a few days and there's no uncle to be seen, it now is very expensive to get back to the village...
• Hi, thanks for your answer, but I'm not completely sure what you're trying to add? Are you basically saying that it's best for the travellers to keep the kids with them instead of ruining their schedule? Because I'm pretty sure that's what I said I want to happen. In other words: I already have that bit planned. (BTW the kids are only something like 7/8, so I doubt the travellers are going to abandon them or set them off to find their own way home, meaning that when the travellers realise the kids are there and it's too late to turn around=the moment the kids become their responsibility.) – s.anne.w Oct 17 '16 at 14:02
• @s.anne.w: I am trying to say that there is no need for a major blocker that prevent the group from going back; just schedule pressure can be sufficient to keep the travelers going forward. – Matthieu M. Oct 17 '16 at 15:04
• At the level of technology implied in the question, you do not ever plan your schedule so tightly that being a single day late will cause major problems. Delays happen: a wagon wheel breaks, or a horse runs off, or any of a number of other things could cause you to lose a few hours, and those could easily add up to missing the boat. – Mark Oct 17 '16 at 17:54
• @Mark: I disagree, you have a rough schedule, but you still have one. And if you are already running late and trying to catch up, then you'll be even more reluctant to turn around. – Matthieu M. Oct 17 '16 at 18:06
• @MatthieuM. Oh yes, I understand now. Sorry, I was just off going to bed when I read it so it didn't sink in very well. Thanks for that, but if I can I would like to have a reason relating to the environment the story is set in too. Sorry for my misunderstand :) – s.anne.w Oct 17 '16 at 21:58
The Great Rann of Kutch in Gujarat, India is a lake that is dry during summer and flooded during monsoon.
-> http://www.travelclassics.com/library/india_rann.shtml
An island with temporary ice sheet in winter.
You can access it for a few weeks in summer, after which ice forms on the sea, making it very difficult to board. In autumn, any boat would risk being caught in the ice, or sunk by an iceberg. In winter, the reaching the island would mean boarding on the ice, crossing a long distance on ice in blizzards, and in spring the melting would make the icebergs and the instability of the ice even more dangerous.
Similar to how some stations (like Dumont D'Urville) in Antarctica are difficult to reach outside of a few months in the warmer season.
1) The place is kind of like bermuda triangle which opens up/becomes navigable at the time of the "green flash" pirate lore.
2)Probably after an geomagnetic storm which makes it possible for aeroplanes to pass with least interference.
3) place surrounded by mountains filled with smog. Uncharted territory. It makes it impossible to for planes to pass. You have to rely on the migrating birds for guidance. (hmm...Pandora-ish)
4) A no-fly zone. Riparian states that fighting over a water source. So, Transportation is possible only when the source is dried up.
5) Mythological Areas: Certain areas are made off-limits certain times of the year as they would be visited by certain deities. (Fishing is banned at my place for few months to facilitate the fishes to breed. also to balance out excessive fishing.)
I see only a handful reasons which are all bound to the classical elements: Earth, wind and fire; water; plus radiation, as a modern "element".
Others have given more detailed ideas for some of them; in general though, the reasons for the "elements" to shift seasonally are bound to celestial movements, either of the planet in question, or of near-by celestial bodies like a twin planet or a moon. A double-star could be interesting. Radiation could come from a star emitting hard gamma which is most of the time shielded by another body.
The only other seasonal shift is geological, like a geyser or volcano with a long-time stable period of a few months; possibly in connection with tidal forces of a close body destabilizing the planet's crust.
• I can see how a band of old funky men people singing classics would repel people trying to reach the place. XD – njzk2 Oct 17 '16 at 14:58
• @njzk2 Lol... true... their heads may explode... Or an old folks nudist colony. Can't go there in summer, seasonality built-in. – Peter - Reinstate Monica Oct 17 '16 at 15:03
An easy solution to your dilemma would be a one-way-road. A stretch of land that is only passable in one direction. A wide fast flowing river surrounded by impenetrable forest would be an obvious candidate for this scenario.
In that case your travellers would travel in a circle and part of that circle would be the river: A very fast and convenient way to travel … but only in one direction.
Travelling on this river could easily be more than ten times faster than hiking back trough the (dangerous) woods. So the kids would only have to stay hidden for a few days, which is probably more realistic than waiting for the seasons to change.
An underground fire in a coal seam that contains heavy metals making the smoke that rises from it toxic. Such fires have been known to burn for centuries, like in abandoned coal mines.
The valleys near the coal deposit collect the smoke, which is heavier than air.
During the rainy season, runoff dampens the fire and reduces the output of smoke, making the way passable. Occasional droughts make the area inaccessible for four to five years at a time.
They travelled by ice boat. For hundreds of years ice boats were the fastest way to travel, however they only work when there is ice with little to no snow. In the past large cargo ice boats have been built and used to ferry cargo. I could see the kids being very interested in stowing away on one for the experience.
I was primarily going to answer as Zxryya did, so I am torn about answering at all with just the leftovers, but here you go:
If you travel by sea, then the state of the sea matters. A treacherous region of the sea because of rocks or reefs can become completely safe when tide is high. This isn't just a daily cycle, as a few others mentioned, and tide is not the only option for raising the local water level.
When the monsoons come, they fill the cave pass. When the summer comes, the melting snow fills the creeks and rivers with icy water. If that melting ice involves large chunks falling and diverting to various channels unpredictably, that's even weirder, since some areas might rise and lower.
You also have storms: There are places where the storms are rather predictable. You might not know the specific dates that a storm will boil up, but during certain seasons, you can know to expect one within a window. If the trip required is longer than that window, people might know better.
As simple as a steady wind is, it can make navigation tricky. Imagine if the wind is harsh but there are dangerous rocks sticking up out of the sea all over the place. If the wind varies only a few MPH and angle, it still makes that treacherous. If it's less predictable than that, all you need is a narrow straight made up of tricky rocks to avoid, and you've got a very good reason not to go that way.
So, there are some more ways that things can become semi-prdictably inaccessible and linked to almost any schedule that you want.
(What I mean by this is that you can mix and match effects to make the trip accessible when you want it, pretty much.
e.g. The passage is a cave up a mountain side. It's a rather risky climb, what with the local wildlife like goats and wildcats, at the end of the dry season. At the beginning, well, it's underwater. You have to wait for the lake to dry a bit after the rains to open enough to get through. For about a week, once or twice a year, the passage is filled with enough water that shallow boats can simply sail in with cargo. This is their trade time.
e.g.2 The opening to the passage is underwater all year round, but the passage itself is mostly above sea level. The ice on that shelf does this strange thing where it peels back for a few days, revealing the passage. Locals rush out and harvest the various sea creatures during that time.
There are a few ways in which you could use this. In one case, you could have a derelict nuclear power plant spewing out radioactive waste. For most of the year, the leakage is confined to the immediate area around the plant, but certain seasonal extremes could make for difficult traversal alone, not to mention a storm of radiation at your face. These weather disruptions could occur for weeks or months at a time.
You could also keep the planet as it is and make the star highly radioactive with relatively predictable solar flares which scorch every living thing and piece of electronic equipment on the surface, requiring residents or travelers to bunker down during "radiation season." The frequency for these solar flares could be a quick succession lasting less than a day but anything exposed during that timeframe has no chance of survival.
The village is mostly surrounded by very steep mountains. One side of the village is open to outside travel. The ground beneath that opening is filled with natural gas that leaks out and makes the villagers sick and short of breath. They decided to burn the gas to prevent these issues. A giant fire rages almost year round, blocking entry/exit. A very small creek runs from the mountains into the village. They damn up the water and use it for their water needs. During the winter they get excess water and after a year of collection the damn is now full. This is the one time when they let the water flood out and put out the fire so that people can come and go. Once everyone has gone through they start the fire again as villagers start getting sick from the gas. It takes a year of collecting water in the damn before they have enough to put the fire out again. For a reality check on this idea see Burning fire pit
Water levels, but a very different answer than above:
The area is ringed with mountains sufficient to block normal travel. The only reason there is anyone living there is that there is a river that flows through the area, on both ends it flows through caves.
In periods of high flow you run out of ceiling. In periods of low flow your raft runs aground. Note that the safe flow rate for the two caves is different, this gives one window in which you can enter and one in which you can leave and they do not overlap.
Note that properly packaged cargo can be shipped during periods of high flow--pack it to take a beating and drop your container in the river, it's fished out by nets on the other side. The water flow over the ages has worn away any spots that would cause them to hang up.
You could just take a magic approach if a fantasy setting. The town only appears at x location for x amount of time before disappearing to a new location or back to its own dimension. There is a movie called "Krull" where the castle/fortress they needed to reach was only going to be at a specific location for a short time.
Or town is stationary, but protected by a magic veil/curtain/wall that is only passable under specific conditions. (a la "Mists of Avalon")
Or the region could be on a floating island that is only in range for a certain amount of time before it floats out of range again. Maybe it circumnavigates the world/floats with the ocean currents.
Two things come to mind for me that I didn't see mentioned:
• First, fire, a massive forest fire would certainly cut off a return path through a wooded area, and without modern fire fighting equipment they can burn for several months.
• The second is completely out of the loop from natural reasons to be cut off, but what about some sort of conflict: a war, a military action, an invasion. This wouldn't have to have anything to do with your current story, but it could make a nice sub story while providing the tool to muck up a return trip. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.17554450035095215, "perplexity": 1527.3523556488137}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-51/segments/1575540518882.71/warc/CC-MAIN-20191209121316-20191209145316-00087.warc.gz"} |
http://mathhelpforum.com/calculus/89985-fourier-series-problem.html | 1. ## Fourier Series problem
find a half-range series of $f(x)=x^{2} \ \ in \ \ (0,1)$
and then show that:
$\sum_{n=1}^{\infty}{\frac{1}{n^{2}}}=\frac{\pi^{2} }{6}$
i got a series:
$x^{2}=\frac{4}{3}+\sum_{n=1}^{\infty}{\frac{4(-1)^{n}}{n^{2}\pi^{2}}\cos(n\pi x) }$
2. Originally Posted by silversand
find a half-range series of $f(x)=x^{2} \ \ in \ \ (0,1)$
and then show that:
$\sum_{n=1}^{\infty}{\frac{1}{n^{2}}}=\frac{\pi^{2} }{6}$
i got a series:
$x^{2}=\frac{4}{3}+\sum_{n=1}^{\infty}{\frac{4(-1)^{n}}{n^{2}\pi^{2}}\cos(n\pi x) }$
How did you get the lead term $\frac{4}{3}$ ?
3. Originally Posted by silversand
find a half-range series of $f(x)=x^{2} \ \ in \ \ (0,1)$
and then show that:
$\sum_{n=1}^{\infty}{\frac{1}{n^{2}}}=\frac{\pi^{2} }{6}$
i got a series:
$x^{2}=\frac{4}{3}+\sum_{n=1}^{\infty}{\frac{4(-1)^{n}}{n^{2}\pi^{2}}\cos(n\pi x) }$ | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 10, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9923725128173828, "perplexity": 2915.0040950390026}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-43/segments/1508187823605.33/warc/CC-MAIN-20171020010834-20171020030834-00823.warc.gz"} |
https://infoscience.epfl.ch/record/148694/ | ## From oxide surface to organic transistor properties: the nature and the role of oxide gate surface defects
By applying various surface treatments to the oxide gate of pentacene transistors, both in vacuum (H2, O2 and Ar plasma treatments) and in aqueous solution, we were able to vary the balance between oxygen-free radicals (Si•), oxygen-centered radicals (Si−O• and Si−O−O•), and other defect types such as silanol (Si−OH), silicon hydride (Si−H), and silicate groups (Si−O−). The consequences of these modifications on the microstructure of pentacene deposited onto the gate have been studied by contact angle measurements and atomic force microscopy. The changes in the transport properties of the ultrathin devices were deduced from their electrical characteristics and from independent four-probe measurements. While the wetting properties of the oxide and in turn the pentacene growth process is mainly controlled by the Si−OH/Si−O− balance, it has been evidenced that oxygen-centered radicals act as charge transfer centers and determine to a large extent the transport properties of many thin-film transistors.
Published in:
Journal of Physical Chemistry C, 114, 15, 7153
Year:
2010
Publisher:
American Chemical Society
ISSN:
1932-7447
Keywords:
Laboratories: | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.885828971862793, "perplexity": 5194.942033075717}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-34/segments/1596439738723.55/warc/CC-MAIN-20200810235513-20200811025513-00482.warc.gz"} |
https://stats.stackexchange.com/questions/254746/what-is-the-meaning-of-double-bars-and-2-at-the-bottom-in-ordinary-least-squares/254747 | # What is the meaning of double bars and 2 at the bottom in ordinary least squares?
I saw this notation for ordinary least squares here.
$$\min_w \left\| Xw - y \right\|^2_2$$
I have never seen the double bars and the 2 at the bottom. What do these symbols mean? Do they have specific terminology for them?
• The use of the double bars just indicates that we are using the L2 norm. – Michael Chernick Jan 5 '17 at 17:18
• @MichaelChernick and the 2? Is that part of "L2 norm"? – Aseem Bansal Jan 5 '17 at 17:19
• Yes, like L2, there is also L1. – Jon Jan 5 '17 at 17:22
• I think $X_w$ should be $Xw$ since $w$ is a vector – ilanman Jan 5 '17 at 18:01
• @ilanman Yes that is what was in the notation before the edit. I changed it back – Aseem Bansal Jan 5 '17 at 18:07
You're talking about the $\ell_2$-norm (Euclidean norm) of the vector ($Xw - y$). If this foreign to you, briefly, the $\ell_p$-norm of a vector $u \in \mathbb{R}^{n}$, is:
$$\|u\|_p = \big(\sum_{i=1}^{n} |u_i|^p\big)^{\frac1p}$$
So in your case $\|u\|_2^2 = (\big(\sum\limits_{i=1}^{n} |u_i|^2\big)^{\frac12})^2 = \sum\limits_{i=1}^{n} u_i^2$ which is consistent with the sum of squared residuals for a linear regression. In the context of regression problems, you'll also see this a lot in mean squared error (MSE) calculations, and in ridge regression.
This is a common norm (among other reasons, it's mathematically convenient), so when it's obvious from the context, you'll see the lower $2$ omitted, and just $\|u\|^2$.
As mentioned in the comments, you may also see the $\ell_1$-norm:
$$\|u\|_1 = \sum_{i=1}^{n} |u_i|$$
Which corresponds to the absolute value. Again, you'll see this in mean absolute error (MAE) or lasso problems.
Other popular norms:
• $\ell_0$-norm: Hamming distance, or # of non-zeros in a vector, i.e. in calculating the sparsity of a vector. Technically this isn't a norm (it's a cardinality function), because you have a $\frac{1}{0}$ term in the definition, but it has the form of a norm so we call it one.
• This norm is the ideal norm used in inducing sparsity for regression problems since we really want to zero out coefficients, however computing $\ell_0$ regularization is NP-hard, so instead we approximate it with $\ell_1$ which is solvable via linear programming. It's also popular in Compressed Sensing.
• $\ell_{\infty}$-norm: = $\underset{i} {\text{max}}$ $\{|x_i|\}$ for $i = 1, ..., n$
• $\|A\|_F$: Frobenius (Euclidean) norm, applied to a matrix $A \in \mathbb{R}^{n\times m} = \sqrt{\sum \limits_{i=1}^{n}\sum \limits_{j=1}^{m}|a_{ij}|^2}$
• The link to wolfram alpha was really helpful. – Aseem Bansal Jan 5 '17 at 18:12
• You write that the $\ell_0$ (pseudo)norm counts the number of zeroes in a vector—did you perhaps mean the number of non-zero entries? (This would be more consistent with what I've seen, and also would mean that $\lVert u \rVert_{0}$ would be the Hamming distance between $u$ and $0 \in \mathbb R^n$, as opposed to being $n$ minus that distance.) – wchargin Jan 5 '17 at 22:16
• Spelling error: "Frobenius". – hobbs Jan 6 '17 at 8:22
• Instead of "this is a common norm" I would've just said "L2 is the norm" ;) – Mehrdad Jan 6 '17 at 11:26 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8675640225410461, "perplexity": 592.4314809229384}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-09/segments/1550247496694.82/warc/CC-MAIN-20190220210649-20190220232649-00082.warc.gz"} |
https://www.lil-help.com/questions/40537/assignment-2-lasa-iamphetamine-use-and-abuse | Assignment 2 LASA IAmphetamine Use and Abuse
# Assignment 2 LASA IAmphetamine Use and Abuse
S
0 points
Assignment 2 LASA I-Amphetamine Use and Abuse
Amphetamine Use and Abuse in America
Abstract
Since the 19th century when Americans first discovered new wonder drugs like morphine, heroin,
and cocaine, our society has confronted the problem of drug abuse and addiction. The United
States--grappling with its first drug epidemic in the early 20th century--gradually instituted
effective restrictions: at home through domestic law enforcement and overseas by spearheading a
world movement to limit opium and coca crops. By World War II, American drug use had
become so rare, it was seen as a marginal social problem. The first epidemic was forgotten.
During the 1960s, drugs like marijuana, amphetamines, and psychedelics came on the scene, and a
new generation embraced drugs. Today with the drug...
Assignment 2
solarc
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Excerpt from file: Assignment2LASAIAmphetamineUseandAbuse Assignment2LASAIAmphetamineUseandAbuse AmphetamineUseandAbuseinAmerica Abstract Since the 19th century when Americans first discovered new wonder drugslikemorphine,heroin, andcocaine,oursocietyhasconfrontedtheproblemofdrugabuseand addiction.TheUnited
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Surround your text in *italics* or **bold**, to write a math equation use, for example, $x^2+2x+1=0$ or $$\beta^2-1=0$$
Use LaTeX to type formulas and markdown to format text. See example. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.34354063868522644, "perplexity": 29485.206651538032}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-51/segments/1544376825349.51/warc/CC-MAIN-20181214022947-20181214044447-00206.warc.gz"} |
https://math.stackexchange.com/questions/3347476/find-the-largest-positive-integer-which-can-divide-the-sum-of-any-five-such-numb | Find the largest positive integer which can divide the sum of any five such numbers.
Five different positive integers are such that if we take any two of them, possibly the same number twice, exactly nine different sums may be obtained. Find the largest positive integer which can divide the sum of any five such numbers.
I have no idea how to approach this problem hints, suggestions, and solutions would all be appreciated.
Taken from the 2015 CIMC
Suppose the positive integers are $$a.
Then $$2a give nine distinct sums. So these must be the only sums of pairs.
Then for $$a+c$$ we have $$a+b
So $$a+c = 2b$$
Similar reasoning will show that
$$b+d=2c$$;
$$c+e=2d$$;
$$a+d=b+c$$;
$$b+e=c+d$$; and
$$a+e=2c$$.
From all this we obtain: $$(c-b)-(b-a)=(a+c-2b)=0$$
So $$c-b=b-a$$.
Similarly we will end up with $$e-d=d-c=c-b=b-a$$.
So the five numbers are in arithmetic progression. So their sum is divisible by $$5$$ (the sum will be $$5$$ times the middle value).
• If we take three numbers $1$,$5$ and $6$ such that $1$+$5$<$1$+$6$<$5$+$6$ ,it is not satisfying $a$+$b$=2$c$ condition? – BJKShah Sep 7 '19 at 17:09
• Sir how did you write a +c = 2b step – Rishi Sep 7 '19 at 17:18
• @BJKShah You must have $1+5 < 5+5 < 5+6$ are then only possible sums. If you have $1+6 \ne 5+5$ you will have more than $9$ sums. – fleablood Sep 7 '19 at 17:18
• The thing is those are the only nine sums. $a+ b< 2b < b+c$. So eve you have any $x+y$ so that $a+b < x + y < b+c$ the only possible option to have *only nine sums is if $x + y = 2b$ And $a+b < a+c < b+c$ and $a+b < 2b < a+c$. So the only option is $a+c = 2b$. If $a+c \ne 2b$ then you will have at least $10$ different sums. – fleablood Sep 7 '19 at 17:22
Suppose I have a set of such numbers with sum $$S$$. If I add $$1$$ to each of the five numbers, I don't change the fact that the condition is achieved, but I change the sum to $$S+5$$. This means that the only possible answers to the question are the numbers $$1$$ and $$5$$. [This observation is not necessary, but is the kind of useful guide to what might be happening and also check on calculations which comes in handy].
I can spot two chains of nine sums which must be different (one given in another answer). The corresponding terms of the chains must then be equal, and that shows that the terms must be in arithmetic progression. Five consecutive terms of an AP have sum divisible by $$5$$. I suggest trying to find the second chain for yourself.
Then with $$a\gt b\gt c \gt d \gt e$$ I have both $$2a\gt a+b\gt a+c\gt a+d\gt a+e\gt b+e\gt c+e\gt d+e \gt 2e$$ and $$2a\gt a+b\gt 2b\gt b+c\gt2c\gt c+d\gt 2d \gt d+e \gt 2e$$ whence $$a+c=2b, a+d=b+c, a+e=2c, b+e=c+d, c+e=2d$$ from which $$a-b=b-c, a-b=c-d, [a-c=c-e], b-c=d-e, c-d=d-e$$ showing that there is a common difference - the middle term is not needed for this. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 26, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7627087831497192, "perplexity": 3178.741771896336}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-10/segments/1581875145966.48/warc/CC-MAIN-20200224163216-20200224193216-00243.warc.gz"} |
http://mathhelpforum.com/geometry/155598-what-straight.html | # Math Help - What is straight?
1. ## What is straight?
I want to define straight using the definition of having 180 degrees, but how do you explain 180 degrees?
Also what types of symmetry are considered line symmetry?
2. Originally Posted by loutja35
I want to define straight using the definition of having 180 degrees, but how do you explain 180 degrees?
Also what types of symmetry are considered line symmetry?
First a comment. Many who have worked in axiomatic geometry do not like using ‘degrees’ as a measure of angles.
An angle is the union of two rays with a common endpoint; as in $
\angle BAC = \overrightarrow {AB} \cup \overrightarrow {AC}$
Now a straight angle would be the case in which $C-A-B$.
$A,~B,~\&~C$ are collinear and $A$ is between $B~\&~C$. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 5, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9111307859420776, "perplexity": 804.0693758928114}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": false}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-41/segments/1410657138017.47/warc/CC-MAIN-20140914011218-00168-ip-10-234-18-248.ec2.internal.warc.gz"} |
https://www.physicsforums.com/threads/desperate-bonus-problem.140099/ | # Desperate/Bonus problem
1. Oct 26, 2006
### Newton's Protege
My instructor has assigned me a bonus problem that I have no idea how to do. It is worth 25 points and I need these points very badly! I would be so grateful if anyone knows how to do this problem.
A mass sits on a frictionless sphere. The mass slides down the sphere to a certain point. The mass then acts like a projectile at that point. What is the angle of the point where the mass leaves the sphere. This angle is 48 degrees. Centripetalal acceleration is involved and so is conservation of energy. The instructor wants a mathematical proof of this. He said this can be accomplished within three lines on a sheet of paper. Apparenly, it is a classic "textbook problem" but it is absent from my text book. I have enclosed an attached file to better illustrate what is happening
#### Attached Files:
• ###### A mass is placed onto a frictionless sphere.doc
File size:
20.5 KB
Views:
100
2. Oct 26, 2006 | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9506638050079346, "perplexity": 461.6886722299122}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-26/segments/1498128320865.14/warc/CC-MAIN-20170626203042-20170626223042-00169.warc.gz"} |
http://www.chegg.com/homework-help/questions-and-answers/a-long-solenoid-has-n-turns-per-unit-length-and-is-carrying-a-certain-current-i-an-electro-q3188260 | ## Solenoid
A long solenoid has n turns per unit length and is carrying a certain current i. An electron moves with speed v inside the solenoid in a circle of radius r perpendicular to the solenoid axis. Find an expression for the current i in terms of the given variables. (Use any variable or symbol stated above along with the following as necessary: me for the electron mass, e for the elementary charge, ?0 for the permeability of free space.) | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8105112314224243, "perplexity": 381.7049489971086}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2013-20/segments/1368702849682/warc/CC-MAIN-20130516111409-00015-ip-10-60-113-184.ec2.internal.warc.gz"} |
http://physics.stackexchange.com/questions/16850/is-0-0-0-an-undefined-vector?answertab=oldest | Is (0,0,0) an undefined vector?
I'm not sure what to make of the direction of a vector with components (0,0,0). Is it an undefined vector?
-
Wikipedia: en.wikipedia.org/wiki/Null_vector – Qmechanic Nov 11 '11 at 22:01
2 Answers
There's absolutely nothing wrong with a vector having all zero components. But a vector like that does have an undefined direction. So the definition of a vector as "something which has a magnitude and a direction" can throw you off here a little.
-
In mathematics that is the identity element 0 for vector addition, and is a key object in the definition of a vector space.
Physically, if $(0, 0, 0)$ is the position vector of some particle, then that just means it is located at the origin.
- | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7091668248176575, "perplexity": 454.0929337799759}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": false}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-35/segments/1408500826016.5/warc/CC-MAIN-20140820021346-00170-ip-10-180-136-8.ec2.internal.warc.gz"} |
https://puzzling.stackexchange.com/questions/53210/simple-combination-of-riddles | # Simple combination of riddles!
Embedded in me lies the crucial key,
don't try too hard to trust all of me.
interesting, this riddle I hope you find,
these sentence structures, you must not mind.
Heed me not, for I leave very little tracks.
in a place not far, I have buried them in the past.
so where oh where, should i start?
two, the number of steps to solve me thorough.
off all the places, it can't get more obvious.
ready yourself, for here comes the hard partt.
yjcvfqaqwvjkpmqhvjkutkffng
The first letters of each line spell out
Edit History
This is also hinted at by
The line "I have buried them in the past"
So if we
Check the puzzle's edit history, we see that five letters have been changed. Together these spell out "shift".
This points at
A rot cipher, specifically rot24. This is hinted at by the line "two, the number of steps to solve me thorough" - we're moving every letter two steps backward (or 24 steps forward; they're basically the same thing).
If we use this to decode the last line, we get the final message:
What do you think of this riddle?
• Based on an earlier solution that was accepted but then deleted. – F1Krazy Jul 7 '17 at 11:11 | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8067346215248108, "perplexity": 2834.4019512527975}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-17/segments/1618039379601.74/warc/CC-MAIN-20210420060507-20210420090507-00244.warc.gz"} |
https://tutorials.pytorch.kr/intermediate/parametrizations.html | # Parametrizations Tutorial¶
Author: Mario Lezcano
Regularizing deep-learning models is a surprisingly challenging task. Classical techniques such as penalty methods often fall short when applied on deep models due to the complexity of the function being optimized. This is particularly problematic when working with ill-conditioned models. Examples of these are RNNs trained on long sequences and GANs. A number of techniques have been proposed in recent years to regularize these models and improve their convergence. On recurrent models, it has been proposed to control the singular values of the recurrent kernel for the RNN to be well-conditioned. This can be achieved, for example, by making the recurrent kernel orthogonal. Another way to regularize recurrent models is via “weight normalization”. This approach proposes to decouple the learning of the parameters from the learning of their norms. To do so, the parameter is divided by its Frobenius norm and a separate parameter encoding its norm is learnt. A similar regularization was proposed for GANs under the name of “spectral normalization”. This method controls the Lipschitz constant of the network by dividing its parameters by their spectral norm, rather than their Frobenius norm.
All these methods have a common pattern: they all transform a parameter in an appropriate way before using it. In the first case, they make it orthogonal by using a function that maps matrices to orthogonal matrices. In the case of weight and spectral normalization, they divide the original parameter by its norm.
More generally, all these examples use a function to put extra structure on the parameters. In other words, they use a function to constrain the parameters.
In this tutorial, you will learn how to implement and use this pattern to put constraints on your model. Doing so is as easy as writing your own nn.Module.
Requirements: torch>=1.9.0
## Implementing parametrizations by hand¶
Assume that we want to have a square linear layer with symmetric weights, that is, with weights X such that X = Xᵀ. One way to do so is to copy the upper-triangular part of the matrix into its lower-triangular part
import torch
import torch.nn as nn
import torch.nn.utils.parametrize as parametrize
def symmetric(X):
return X.triu() + X.triu(1).transpose(-1, -2)
X = torch.rand(3, 3)
A = symmetric(X)
assert torch.allclose(A, A.T) # A is symmetric
print(A) # Quick visual check
We can then use this idea to implement a linear layer with symmetric weights
class LinearSymmetric(nn.Module):
def __init__(self, n_features):
super().__init__()
self.weight = nn.Parameter(torch.rand(n_features, n_features))
def forward(self, x):
A = symmetric(self.weight)
return x @ A
The layer can be then used as a regular linear layer
layer = LinearSymmetric(3)
out = layer(torch.rand(8, 3))
This implementation, although correct and self-contained, presents a number of problems:
1. It reimplements the layer. We had to implement the linear layer as x @ A. This is not very problematic for a linear layer, but imagine having to reimplement a CNN or a Transformer…
2. It does not separate the layer and the parametrization. If the parametrization were more difficult, we would have to rewrite its code for each layer that we want to use it in.
3. It recomputes the parametrization everytime we use the layer. If we use the layer several times during the forward pass, (imagine the recurrent kernel of an RNN), it would compute the same A every time that the layer is called.
## Introduction to parametrizations¶
Parametrizations can solve all these problems as well as others.
Let’s start by reimplementing the code above using torch.nn.utils.parametrize. The only thing that we have to do is to write the parametrization as a regular nn.Module
class Symmetric(nn.Module):
def forward(self, X):
return X.triu() + X.triu(1).transpose(-1, -2)
This is all we need to do. Once we have this, we can transform any regular layer into a symmetric layer by doing
layer = nn.Linear(3, 3)
parametrize.register_parametrization(layer, "weight", Symmetric())
Now, the matrix of the linear layer is symmetric
A = layer.weight
assert torch.allclose(A, A.T) # A is symmetric
print(A) # Quick visual check
We can do the same thing with any other layer. For example, we can create a CNN with skew-symmetric kernels. We use a similar parametrization, copying the upper-triangular part with signs reversed into the lower-triangular part
class Skew(nn.Module):
def forward(self, X):
A = X.triu(1)
return A - A.transpose(-1, -2)
cnn = nn.Conv2d(in_channels=5, out_channels=8, kernel_size=3)
parametrize.register_parametrization(cnn, "weight", Skew())
# Print a few kernels
print(cnn.weight[0, 1])
print(cnn.weight[2, 2])
## Inspecting a parametrized module¶
When a module is parametrized, we find that the module has changed in three ways:
1. model.weight is now a property
2. It has a new module.parametrizations attribute
3. The unparametrized weight has been moved to module.parametrizations.weight.original
After parametrizing weight, layer.weight is turned into a Python property. This property computes parametrization(weight) every time we request layer.weight just as we did in our implementation of LinearSymmetric above.
Registered parametrizations are stored under a parametrizations attribute within the module.
layer = nn.Linear(3, 3)
print(f"Unparametrized:\n{layer}")
parametrize.register_parametrization(layer, "weight", Symmetric())
print(f"\nParametrized:\n{layer}")
This parametrizations attribute is an nn.ModuleDict, and it can be accessed as such
print(layer.parametrizations)
print(layer.parametrizations.weight)
Each element of this nn.ModuleDict is a ParametrizationList, which behaves like an nn.Sequential. This list will allow us to concatenate parametrizations on one weight. Since this is a list, we can access the parametrizations indexing it. Here’s where our Symmetric parametrization sits
print(layer.parametrizations.weight[0])
The other thing that we notice is that, if we print the parameters, we see that the parameter weight has been moved
print(dict(layer.named_parameters()))
It now sits under layer.parametrizations.weight.original
print(layer.parametrizations.weight.original)
Besides these three small differences, the parametrization is doing exactly the same as our manual implementation
symmetric = Symmetric()
weight_orig = layer.parametrizations.weight.original
print(torch.dist(layer.weight, symmetric(weight_orig)))
## Parametrizations are first-class citizens¶
Since layer.parametrizations is an nn.ModuleList, it means that the parametrizations are properly registered as submodules of the original module. As such, the same rules for registering parameters in a module apply to register a parametrization. For example, if a parametrization has parameters, these will be moved from CPU to CUDA when calling model = model.cuda().
## Caching the value of a parametrization¶
Parametrizations come with an inbuilt caching system via the context manager parametrize.cached()
class NoisyParametrization(nn.Module):
def forward(self, X):
print("Computing the Parametrization")
return X
layer = nn.Linear(4, 4)
parametrize.register_parametrization(layer, "weight", NoisyParametrization())
print("Here, layer.weight is recomputed every time we call it")
foo = layer.weight + layer.weight.T
bar = layer.weight.sum()
with parametrize.cached():
print("Here, it is computed just the first time layer.weight is called")
foo = layer.weight + layer.weight.T
bar = layer.weight.sum()
## Concatenating parametrizations¶
Concatenating two parametrizations is as easy as registering them on the same tensor. We may use this to create more complex parametrizations from simpler ones. For example, the Cayley map maps the skew-symmetric matrices to the orthogonal matrices of positive determinant. We can concatenate Skew and a parametrization that implements the Cayley map to get a layer with orthogonal weights
class CayleyMap(nn.Module):
def __init__(self, n):
super().__init__()
self.register_buffer("Id", torch.eye(n))
def forward(self, X):
# (I + X)(I - X)^{-1}
layer = nn.Linear(3, 3)
parametrize.register_parametrization(layer, "weight", Skew())
parametrize.register_parametrization(layer, "weight", CayleyMap(3))
X = layer.weight
print(torch.dist(X.T @ X, torch.eye(3))) # X is orthogonal
This may also be used to prune a parametrized module, or to reuse parametrizations. For example, the matrix exponential maps the symmetric matrices to the Symmetric Positive Definite (SPD) matrices But the matrix exponential also maps the skew-symmetric matrices to the orthogonal matrices. Using these two facts, we may reuse the parametrizations before to our advantage
class MatrixExponential(nn.Module):
def forward(self, X):
layer_orthogonal = nn.Linear(3, 3)
parametrize.register_parametrization(layer_orthogonal, "weight", Skew())
parametrize.register_parametrization(layer_orthogonal, "weight", MatrixExponential())
X = layer_orthogonal.weight
print(torch.dist(X.T @ X, torch.eye(3))) # X is orthogonal
layer_spd = nn.Linear(3, 3)
parametrize.register_parametrization(layer_spd, "weight", Symmetric())
parametrize.register_parametrization(layer_spd, "weight", MatrixExponential())
X = layer_spd.weight
print(torch.dist(X, X.T)) # X is symmetric
print((torch.symeig(X).eigenvalues > 0.).all()) # X is positive definite
## Intializing parametrizations¶
Parametrizations come with a mechanism to initialize them. If we implement a method right_inverse with signature
def right_inverse(self, X: Tensor) -> Tensor
it will be used when assigning to the parametrized tensor.
Let’s upgrade our implementation of the Skew class to support this
class Skew(nn.Module):
def forward(self, X):
A = X.triu(1)
return A - A.transpose(-1, -2)
def right_inverse(self, A):
# We assume that A is skew-symmetric
# We take the upper-triangular elements, as these are those used in the forward
return A.triu(1)
We may now initialize a layer that is parametrized with Skew
layer = nn.Linear(3, 3)
parametrize.register_parametrization(layer, "weight", Skew())
X = torch.rand(3, 3)
X = X - X.T # X is now skew-symmetric
layer.weight = X # Initialize layer.weight to be X
print(torch.dist(layer.weight, X)) # layer.weight == X
This right_inverse works as expected when we concatenate parametrizations. To see this, let’s upgrade the Cayley parametrization to also support being initialized
class CayleyMap(nn.Module):
def __init__(self, n):
super().__init__()
self.register_buffer("Id", torch.eye(n))
def forward(self, X):
# Assume X skew-symmetric
# (I + X)(I - X)^{-1}
def right_inverse(self, A):
# Assume A orthogonal
# See https://en.wikipedia.org/wiki/Cayley_transform#Matrix_map
# (X - I)(X + I)^{-1}
layer_orthogonal = nn.Linear(3, 3)
parametrize.register_parametrization(layer_orthogonal, "weight", Skew())
parametrize.register_parametrization(layer_orthogonal, "weight", CayleyMap(3))
# Sample an orthogonal matrix with positive determinant
X = torch.empty(3, 3)
nn.init.orthogonal_(X)
if X.det() < 0.:
X[0].neg_()
layer_orthogonal.weight = X
print(torch.dist(layer_orthogonal.weight, X)) # layer_orthogonal.weight == X
This initialization step can be written more succinctly as
layer_orthogonal.weight = nn.init.orthogonal_(layer_orthogonal.weight)
The name of this method comes from the fact that we would often expect that forward(right_inverse(X)) == X. This is a direct way of rewriting that the forward afer the initalization with value X should return the value X. This constraint is not strongly enforced in practice. In fact, at times, it might be of interest to relax this relation. For example, consider the following implementation of a randomized pruning method:
class PruningParametrization(nn.Module):
def __init__(self, X, p_drop=0.2):
super().__init__()
# sample zeros with probability p_drop
mask = torch.full_like(X, 1.0 - p_drop)
def forward(self, X):
def right_inverse(self, A):
return A
In this case, it is not true that for every matrix A forward(right_inverse(A)) == A. This is only true when the matrix A has zeros in the same positions as the mask. Even then, if we assign a tensor to a pruned parameter, it will comes as no surprise that tensor will be, in fact, pruned
layer = nn.Linear(3, 4)
X = torch.rand_like(layer.weight)
print(f"Initialization matrix:\n{X}")
parametrize.register_parametrization(layer, "weight", PruningParametrization(layer.weight))
layer.weight = X
print(f"\nInitialized weight:\n{layer.weight}")
## Removing parametrizations¶
We may remove all the parametrizations from a parameter or a buffer in a module by using parametrize.remove_parametrizations()
layer = nn.Linear(3, 3)
print("Before:")
print(layer)
print(layer.weight)
parametrize.register_parametrization(layer, "weight", Skew())
print("\nParametrized:")
print(layer)
print(layer.weight)
parametrize.remove_parametrizations(layer, "weight")
print("\nAfter. Weight has skew-symmetric values but it is unconstrained:")
print(layer)
print(layer.weight)
When removing a parametrization, we may choose to leave the original parameter (i.e. that in layer.parametriations.weight.original) rather than its parametrized version by setting the flag leave_parametrized=False
layer = nn.Linear(3, 3)
print("Before:")
print(layer)
print(layer.weight)
parametrize.register_parametrization(layer, "weight", Skew())
print("\nParametrized:")
print(layer)
print(layer.weight)
parametrize.remove_parametrizations(layer, "weight", leave_parametrized=False)
print("\nAfter. Same as Before:")
print(layer)
print(layer.weight)
Total running time of the script: ( 0 minutes 0.000 seconds)
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https://www.physicsforums.com/threads/please-help-problem-due-in-40-min.184091/ | 1. Sep 11, 2007
### mpgriffis
1. The problem statement, all variables and given/known data
Due to several previous unfortunate encounters with law enforcement, your car has been equipped with a GPS tracking device. You know that this device radios your current position to police headquarters at precisely hour intervals, but you don't know the exact time at which this occurs (i.e. it could be every hour on the hour, or every hour on the quarter hour, or something else). If the police can prove that you've driven faster than 100 km/hr at any point, then you are busted.
You have been driving from State College to Sandy Springs, Utah (the latest hot Spring Break destination) along a perfectly straight road for several hours at a leisurely constant speed of 80 km/hr. Sandy Springs is only 46 km ahead. You realize that you can now speed up for the remainder of the trip, without getting busted.
What is the maximum average speed at which you can finish the drive to Sandy Springs, with no chance of getting busted by your GPS tracker?
2. Relevant equations
At first, I tried using d = 1/2 (v0 +v)t since we don't know the acceleration. But we don't even know the time, so I tried using v^2=v0^2 +2ad, but we still don't know the acceleration. I'm starting to think that this problem requires more than 1 kinematics equation. But I don't know which ones. Can someone please help me?
3. The attempt at a solution
No idea.
2. Sep 11, 2007
### dukiex3
well, can vf be considered 100km/hr?
3. Sep 11, 2007
### Dick
No complicated formulas here, just average speed. Worst case is that they check your speed just as you arrive. So you go at some velocity V for 46km. Takes time T=46km/V. The rest of the hour (1-T) was at 80km/hr. Compute an average speed for the last hour of the trip and see how big V can be before the average speed exceeds 100km/hr. I'm giving you more than the average number of hints since you have another kind of speed problem. Good luck in the 40min.
4. Sep 11, 2007
### Dick
That's a guess, right? No, you can go faster. Not that I advocate violating the law.
5. Sep 11, 2007
### learningphysics
Average speed over 1 hr <100km/h
If it drove at v for the last 46km... what's the time for the last 46km... the rest of the hour it was driving at 80km/h
Use (total distance)/(1 hr) = average speed <=100
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http://www.omphalocele.net/66a5niv7/fe517c-24th-parallel-line | Parallel lines are lines that never intersect. It is the line which demarcates boundary between Pakistan and India in … Line l: x − 3 y = 2 Line l 1 is parallel to line l. Hence, the slope of the required line(s) is (3 1 ). For drawing lines, use the graphing calculator. ? Two parallel lines are cut by a transversal, as shown below. How to Find the Distance Between Two Parallel Lines. Through B, draw a line parallel to these perpendiculars, as shown (the three dotted lines are parallel): Note how we have marked the various angles. Here, three set of parallel lines have been shown - vertical, diagonal and horizontal parallel lines. As the term suggests, both systems are used in parallel for a period of time until there is confidence that the new system is sufficient. Measures of angles formed by a transversal. Pick a room in your house! The 24th parallel south is a circle of latitude that is 24 degrees south of the Earth's equatorial plane, about 60 km south of the Tropic of Capricorn.It crosses the Atlantic Ocean, Africa, the Indian Ocean, Australasia, the Pacific Ocean and South America. Starting at the Prime Meridian and heading eastwards, the parallel 24° south passes through: Learn how and when to remove this template message, https://en.wikipedia.org/w/index.php?title=24th_parallel_south&oldid=1008357769, Articles lacking sources from February 2021, Creative Commons Attribution-ShareAlike License, This page was last edited on 22 February 2021, at 22:19. The 24th parallel north is a circle of latitude that is 24 degrees north of the Earth's equatorial plane, which is about 60 kilometres (37 mi) north of the Tropic of Cancer. So parallel lines are lines that have the same slope, and they're different lines, so they never, ever intersect. ∴ Line l 1 : y = 3 1 x + c Shift the coordinates system, to 2, − 1 as origin. And lucky for us, all of these lines are in y equals mx plus b or slope-intercept form, so you can really just look at these lines and figure out their slope. 24th Parallel is the line which Pakistan claims for demarcation between India and Pakistan. These lines are TTL Parallel lines are lines which are always the same distance apart and never meet. The northernmost section of the border between Mauritania and Mali is defined by the parallel.. At this latitude the sun is visible for 13 hours, 42 minutes during the summer solstice … Associação dos Egressos de Engenharia de Produção da UFPE. :5 All the enlisted soldiers were black, either veterans of the U.S. Practice: Angle relationships with parallel lines. A. x=40 because corresponding angles are equal. This, however, is not recognized by India. Fpsckppsc test preparation is online and social platform which facilitates aspirants and … 24th parallel line between which country. dilly dally The Garage parallel lines De nieuwste Parallel Lines collectie bij ABOUT YOU gratis verzending achteraf betalen gratis retour It crosses the Atlantic Ocean, Africa, the Indian Ocean, Australasia, the Pacific Ocean and South America. The cleanest way to do this uses the vector product: if $\mathbf{n_1}$ and $\mathbf{n_2}$ are the normals to the planes, then the line of intersection is parallel to $\mathbf{n_1} \times \mathbf{n_2}$. Hindenberg Line ‐ Boundary line between Germany and Poland to which German retreated in 1917 during the First World War. Join now. Secondary School. 24th parallel line passes through Gujarat, UP and MP 1. At this latitude the sun is visible for 13 hours, 37 minutes during the summer solstice and 10 hours, 39 minutes during the winter solstice.[1]. Up Next. Perpendicular lines from equation. The line which Pakistan claims should be the Demarcation line between India and Pakistan, not accepted by India. Solution: Through A and C, drawn two lines perpendicular to AX and CY. Triangle angles. Pakistan claims that it is the boundary between India and Pakistan in great Rann of Kutch (Gujarat). Lines which will never intersect each other are parallel. 20th Parallel: 5. ★ 24th Parallel: ----- Line which Pakistan claims for demarcation between India and Pakistan. In our case, the points are (–8,9) and (3,–4). Define the formula for slope. Since you are given a point and the slope, use the point-slope form of a line to determine the equation. Select Page. Driver: Parallel Lines is the fourth installment in the Driver video game series. Parallel lines have the same slope and different y-intercepts. 3x-8 x+88 What is the solution when solved for \times and why? If angles are considered then it is 180 degrees, here the two lines are equal so they will never meet. Clearly, $$\angle x$$ = 20 0 (alternate interior angles) $$\angle y$$ … In order for two lines to be parellel, their slopes have to be the same. Solving Equations Involving Parallel and Perpendicular Lines www.BeaconLC.org©2001 September 22, 2001 4 11. The slope is −3. 30th Parallel north stands one-third of the way between the equator and the North Pole. 1. Examples: Input: m = 2, b1 = 4, b2 = 3 Output: 0.333333 Input: m = -4, b1 = 11, b2 = 23 Output: 0.8 Approach:. When a transversal intersects two lines, eight angles are formed. This, however, is not recognized by India 26th Parallel south is a circle of latitude which crosses through Africa, Australia and South America. Institucional; Relação de Alunos e Egressos; Notícias Parallel lines from equation (example 2) Perpendicular lines from equation. So we need to look for different lines that have the exact same slope. Practice: Equation practice with angle addition. To find an equation that is parallel, the slopes must be equal. ... 2021 February 18, 2021 by Teri Bond. (see examples below). From its activation to 1898, the 24th Infantry served throughout the Western United States. Next lesson. This, however, is not recognized by India Show Instructions. The 24th parallel south is a circle of latitude that is 24 degrees south of the Earth's equatorial plane, about 60 km south of the Tropic of Capricorn. Find the slope of a line parallel to the line y = − 3x + 4. Activity 2. The 25th parallel north is a circle of latitude that is 25 degrees north of the Earth's equatorial plane.It crosses Africa, Asia, the Indian Ocean, the Pacific Ocean, North America and the Atlantic Ocean.. 9/24 Parallel Lines and Angle Pairs A transversal is a line that intersects two other lines at different points. A line parallel to 4x+5y=24 passes through point (0,12). The 24th Parallel line (Sir Creek) is the border located between India and Pakistan. In general, you can skip the multiplication sign, so 5x is equivalent to 5*x. Pakistan claims that it is the boundary between India and Pakistan in great Rann … Identify the slope of the given line… Explanation: . Lines that are parallel to each other will never intersect. So, to find an equation of a line that is parallel to another, you have to … Practice: Equation practice with angles. This calculator find and plot equations of parallel and perpendicular to the given line and passes through given point. Find the slope of the line connecting those two points using the general slope formula, , where the points are and .. Join now. : 1 But on the first day of the week, at early dawn, they went to the tomb, taking the spices they had prepared. In geometry, parallel lines can be defined as two lines in the same plane that are at equal distance from each other and never meet. x-3y=24 Solve the system of equations 2x-y=1; x+2y=8 graphically and find the coordinates of the points where corresponding lines intersect y-axis. But this is not recognized by India. Find the parallel line using the point-slope formula. Each overhead light will have at least one switch in series with the light, so you can turn it on and off. The 24th parallel north is a circle of latitude that is 24 degrees north of the Earth's equatorial plane, which is about 60 kilometres (37 mi) north of the Tropic of Cancer. Log in. Sides of various shapes are parallel to each other. It also crosses Africa, Asia, the Indian Ocean, the Pacific Ocean, North America and the Atlantic Ocean. : 1 But on the first day of the week, at early dawn, they came to the tomb bringing the spices which they had prepared. If movement is possible, ball will go to the specified empty field. Learn how to identify different types of lines, including vertical, horizontal, parallel and perpendicular. If two lines are drawn so that they could extend into infinity without ever meeting each other, these lines are called parallel. This is the currently selected item. Starting at the Prime Meridian and heading eastwards, the parallel 24° north passes through: http://aa.usno.navy.mil/data/docs/Dur_OneYear.php, https://en.wikipedia.org/w/index.php?title=24th_parallel_north&oldid=1000958236, Creative Commons Attribution-ShareAlike License, This page was last edited on 17 January 2021, at 15:26. The WildPlay zip-line runs 670 metres along... Get premium, high resolution news photos at Getty Images A parallel run is the practice of keeping an old system operational after a new system is launched. Parallel Lines items snel & met gratis verzending bestellen. 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System is launched, business capabilities, processes and resources a light that goes on when the opens. Driver video game series D connector and may be programmed as inputs, outputs, or both ;!, Australia and South America the distance between two parallel lines are available on a (... Substitute for and in the same slope the Pacific 24th parallel line and South America therefore, 63- 4! Vertical, horizontal, parallel and perpendicular compressor and a light that goes on when door. Natural habitat names: • corresponding angles are equal is latitude which crosses Africa. Crosses Africa, Asia, the points where corresponding lines intersect y-axis de Alunos e Egressos ; Notícias Select.! Overhead light will have at least one switch in series with the light, . In slope intercept form, with m = −3 and b = 4 line y 3. And off Solve the system of equations 2x-y=1 ; x+2y=8 graphically and find the slope of the are... Shown - vertical, horizontal, parallel and perpendicular to the given and. Obtain the result has a compressor and a given point to substitute for and in the graph are parallel it! The question ABOUT parallel or perpendicular lines www.BeaconLC.org©2001 September 22, 2001 4 11 are..! Set of parallel and perpendicular, not accepted by India to 5 * x 3x-8 x+88 What the. Through the point entered … Support from Dilly Dally will be Hotel and. And coeficients may be entered as fractions, integers or decimals ( example 2 ) lines. Business capabilities, processes and resources has a compressor and a given point to substitute for and in graph! 55 because interior angles are equal example 2 ) perpendicular lines, including,..., in slope intercept form, with m = −3 and b = 4 and line C parallel! Have at least one switch in series with the same slope we need to for. \Times =48 because alternate exterior angles are equal 4 11 C Shift coordinates... It also crosses Africa, the Pacific Ocean and South America for,!, parallel and perpendicular lines www.BeaconLC.org©2001 September 22, 2001 4 11 the... And Myanmar -24th parallel specified empty field given point to substitute for in. =34\Div 4 b \times ∈ O C. \times =48 because alternate exterior angles are two angles in the are... For \times and why Makwanajiya AGREGAEP 24th parallel line will generate a step-by-step on... An equation, in slope intercept form, which is derived from the slope, use the point-slope,... Perpendicular lines, you can turn it on and off missions included frontier! Practice of keeping an old system operational after a new system is launched also be to. Would just be the Demarcation line between India and Pakistan in great Rann of Kutch Knowledge Mcqs which Countries! Latex ] m=2 [ /latex ] \square 55 because interior angles on the same slope, and they 're lines... They have the same y-intercept, then they would just be the same and. 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## Crew Rotation In The Superyacht Industry – Part II
Following our last post and feedback, we take a deeper look at rotation. We believe the benefits for crew are well understood, so in this piece we focus mainly on how rotation can improve yacht ownership and whether the benefits outweigh any additional costs involved?
With traditional leave arrangements, crew normally take their accrued leave at the end of a contract if a seasonal job or, when a yachts program allows e.g. at the end of the season, during a refit or crossing, or the off-season lay-up period. This approach means crew may work for prolonged periods before a break and, planning for their leave and/or training required for career progression, is very difficult.
Although a yacht can be admired for its aesthetic beauty and technical excellence, ultimately it is the professional crew who are responsible for ensuring the yacht delivers on the dreams and aspirations of an owner. Employing and retaining the very best crew is, without doubt, fundamental to success. And, as the fleet grows and yachts get bigger, the competition for quality crew will only increase; to meet this challenge terms of employment will need to evolve and rotation will become an ever more important consideration for many.
### So What is Rotation?
I think the simplest explanation is job-sharing, where, most commonly, two crew share the same job and alternate their time onboard and on leave. This is normally the situation with the most senior crew with work/leave ratios such as 2:2 or 3:3 and other crew on ratios such as 5:1 or 3.1.
Although there may be different variations/ratios, not all crew have to be on the same terms, the general principle is that the yacht is fully manned at all times and leave is properly scheduled – within accepted variances due to a yachts program.
With any job share, especially in positions of leadership and responsibility, one of the challenges is ensuring the two people sharing the job have mutual respect, similar ethics, behaviour and work standards. This dynamic is important as consistency is fundamental to the health of the team. Any major differences can lead to uncertainty and confusion amongst the crew and a breakdown in the team and performance – success, relies on identifying and employing the right crew.
### Yacht Availability – Asset Optimisation
Large yachts are a significant investment, and one of the joys of yacht ownership is the freedom to use it without restriction. Therefore, outside of crossings or refit, any time a yacht is unavailable to a yacht owner or, for charter, would seem to be a poor return on the investment.
Even on one season yachts I have seen where the lack of crew has prevented an owner from using their yacht in winter, and there are some stunning days in the winter in the Med! This was frustrating for the owner and something that did not make sense given the investment involved, including the capital costs and operational expenditure.
Rotation ensures that it is the yacht owner who determines when to use the yacht and is not restricted due to crew leave, or quality diminished by use of temporary crew. Lack of crew due to leave commitments would no longer be a reason to curtail use or compromise on safe manning in port.
### Temporary Crew
Temporary crew is an option for replacing crew on leave and keeping the yacht available to the owner, though this is not normally the most successful strategy as recruitment is often at short notice and choice may be limited.
Further, there is no guarantee they will perform, have the same professional standards, gel with the crew and/or yacht owner and family. The training and supervision they will require and, repeated every time a temp is used, is a drain on crew resources creating inefficiencies in the team’s performance and the yachts operation. This can have a negative impact on the quality of service, levels of safety, standards of maintenance and the yacht owner’s experience.
Employing temporary crew has repeating costs such as agency fees, salary, uniform and travel and these can be used to offset the additional cost of permanent crew required for rotation.
### Crew Retention
It is widely accepted that long periods onboard without a suitable break can lead to fatigue and burnout, especially on busy yachts, and the uncertainty in leave planning and difficulty in having a normal life off the yacht can affect the welfare and well-being of crew. All these are contributing factors to the high turnover of crew that is so often complained about in our industry.
The senior crew are even more exposed to these stresses due to the pressures of their roles. These are the mature/older more experienced crew that others look to for leadership, training and motivation – they are the foundation on which the long-term success of the yacht is built. Many will have reached a point their career and/or life where they may have a family or, in a relationship, and are interested in building a fulfilling life away from the yacht.
Junior crew tend to have different priorities, as alluded to in Part I, so whilst extended leave is not so important, a reasonable amount of leave and having the ability to plan for their time off is still a key influence.
Rotation also provides opportunities for advancement and helps remove another oft cited reason for leaving. For example, it may allow a chief officer to step up to rotational captain, or a 2nd stewardess to become rotational chief stewardess. It adds to motivation and further helps retain the skills and knowledge built-up through mentoring and their time served onboard.
Although yacht owners may be frustrated by the constant churn of crew, they may not fully appreciate the hard and soft costs involved. The hard costs include such things as recruitment fees, employment setup costs, uniform, training, etc. and easiest to explain. The soft costs, although harder to put a monetary value on, are also important considerations. Arguably, the biggest cost to crew turnover is the loss of knowledge which could be technical, operational or, even personal to the yacht owner and family. There is also the disruption to the team and operation, and the time and effort required to train and supervise new crew on their journey to becoming an integral part of the team. And, all of these could affect a yacht owners enjoyment; something you cannot put a value on!
It’s also difficult to appreciate the importance a yacht owner places on seeing familiar faces amongst the crew; it helps them relax, and gives them comfort in the knowledge that the crew understand their needs and will make their stay flow seamlessly. I have heard familiarity being used as a reason against rotation due to the additional crew, but this should not be a major concern as it doesn’t take long for those crew to be a familiar sight – they just won’t all be onboard at the same time!
Rotation does not completely eliminate crew turnover as there will always be influences outside the control of the yacht but, by incentivising crew through better leave and improved employment prospects, a yacht owner can remove some of the key reasons for leaving.
### Yes, But Rotation Is Expensive!
This is often, understandingly, the refrain from yacht owners and rightly so, as the payroll can be between 25% – 40% of the operating budget, and it is frequently the captain who must explain how increasing these costs can be of benefit a yacht owner.
Within any proposal, the crew must also buy-in to the idea and understand that a trade-off may be required on their part. It would seem obvious to anyone that if you work less then you should be paid less? Unfortunately, crew do not always see it this way and some expect to work significantly less days whilst still earning the same money – this stance is often where the idea never even gets off the ground. That being said, there are examples of very generous salaries combined with rotation – there is no standard in yachting!
Once an owner recognises the benefits it is clearly easier to implement prior to employment of the crew, such as during a new-build or before purchase. Changing an operational yacht to a rotational structure is a little more challenging due to the uplift in costs, and any salary negotiations that may be required.
The examples below show how changing annual leave allowances affects the number of days worked per year.
• 90 days leave per year, plus one day off per week when onboard, effectively works 236 days per year. On 1:1 rotation they work 183 days per year (no day off per week). This is a reduction of 22%.
• 60 days leave per year, plus one day off per week when onboard, effectively works 261 days per year. On 1:1 rotation they work 183 days per year (no day off per week). This is a reduction of 30%.
• 38 days leave per year, plus one day off per week when onboard, effectively works 280 days per year. On 5:1 rotation, plus one day off per week when onboard, they work 261 days per year. This is a reduction of 7%.
An interesting point is that a full-time employee in the UK with statutory holiday, public holidays and weekends, effectively works 228 days per year.
The effective workdays is also the number used to calculate the daily pay rate. Using that figure you can see that to keep the rate the same would result in a salary reduction by the same percentage – as mentioned, this is something that crew may find difficult to accept, but may also make the salary uncompetitive.
As an exercise I developed a detailed spreadsheet that compares a ‘normal’ yacht with a crew complement of 19 onboard with average salaries, leave and travel costs, against the same yacht with a ‘rotation’ – the table below summarises the leave differences.
### ROTATION LEAVE
Captain 90 days 3:3 Ratio = 183 days
Chief Officer, 2nd Officer,
Purser, Chief Stewardess,
60 days 3:3 Ratio = 183 days
Bosun, Deckhands,
2nd Stewardess,
Stewardesses
38 days 5:1 ratio = 60 Days
Engineers 3:3 Ratio = 183 days 3:3 Ratio = 183 days
### 31
The junior crew are on a 5:1 rotation which, in general, may suit them better given their different priorities to the senior crew. There is still a good amount of time off to rest and recuperate and, importantly, an ability to plan their leave.
What this detailed examination highligthed is that rotation does not result in a doubling crew costs which, is often the assumption. In this particular case the increase in crew costs is between 8% – 24% depending whether salaries are adjusted for effective workdays, left at the original rates, or negotiated somewhere in-between.
### Summary
It is clear that there are costs and benefits associated with rotation; although it is important to perform a detailed analysis of all the cost inputs, outputs and variances – this is a fundamental part of any justification. The benefits, apart from the financial savings that can be made through the reduction in temporary crew and crew turnover, are dependent on the value and importance ‘weighting factor’ that an yacht owner places on these, and whether, on balance, these outweigh the costs and add value to the quality of the ownership experience.
Finally, and worth considering; although rotation is not yet the norm, it is growing trend, especially for the larger yachts – although I have heard of its use on <500gt yachts as well – and more crew will be looking for this in the future – I think most yacht crew would agree that this is a positive change and demonstrates the industries progressive growth and evolving maturity.
As we have mentioned previously, OnlyCaptains are not offering prescriptive solutions, we simply present ideas and suggestions that may offer captains some useful ideas that they can use in their own command and act as a catalyst to further industry discussion – we hope you enjoyed this post and welcome any feedback.
By |2020-11-05T12:55:38+01:00October 28th, 2020|captains, leadership, mentoring, yachtowners|
## Crew Rotation In the Superyacht Industry – Part I
Although commercial shipping has rotated crew for many years, it is a recent phenomenon in the superyacht industry. It started to become a reality on yachts first with engineers, and then on the larger yachts where manning regulations required officers with STCW qualifications.
When rotation first started is a little unclear; it was certainly in use in the late 70’s when I was with BP Shipping – though it only applied to deck and engineering officers. However, what was clear, that it was not born out of regulation, but driven by market forces and a recognition that to attract and keep the right people they had to offer a better work/life balance. Today, these very same reasons are relevant to yachting.
So, in our latest post, we are going to take a dive into rotation and, due to its importance to many captains, their families and yacht owners, we will break it down into two parts and focus on the whys, how’s and the impact this fundamental employment change has had on the yachting community.
This week in Part I, Brendan is writing of his own employment journey to supply some context, then next week in Part II, Malcolm will take a deeper look at the pros and cons and how you might present the idea to a yacht owner using a worked example.
### Brendan
I entered yachting when contracts and structured leave were rare to the point of not known. Leave was when it suited the yacht’s programme, often with little notice. Crew would scramble to make last minute arrangements when a window opened. With limited leave, weekends in port was our time to get away, explore and socialise, leaving the yacht to the care of a couple of watchkeepers. Regardless of age or relationship status, life revolved around the yacht and no alternate lives ashore were maintained.
This began to change for me in 2007 when I joined my first 100m+ yacht and realised there was no stopping a yacht of this scale. It needed crew every day to keep the show running and there were no more ‘weekends with a couple of watchkeepers’. I remember naively saying to the Heads of Departments we would shut the yacht down one weekend for everyone’s rest; they humoured me, said yes, but ignored the instruction and kept the yacht working the way it demanded.
Since that time, I have modelled many and various employment structures for yacht owners and their representatives. When I do these, I do not speak of rotation from a crew’s perspective, it is with consideration of the yacht owners needs and their investment. My point being that the yacht, the owner and guest experience should not suffer because of crew taking leave. I support this position with a crude calculation; add the finance cost of the yacht to the operating expenses and divide by 365 to gain the cost per day of the yacht’s existence. The number can be staggering and to think that you would intentionally stop the operation so the team can take days off does not show good value.
Further to this crude calculation, the owner is reminded that the beauty of yacht ownership is freedom and spontaneity. Rotation can allow that when a gap opens in their diary, they can escape to their yacht and enjoy the pleasure of being on the water with family and friends; something that is even more relevant today.
In one of the presentations the yacht owner agreed for senior crew without hesitation, saying, “but yes, they have families, and we want them to be focussed on us when they are here and not worried about when they can get home.” For junior crew there was a different perspective with the principal asking, “why do these crew want so much time away when they were young?” Weren’t these the years to earn money, travel and gain experience needed to progress?
Malcolm’s comment – the latter point I also heard from an owner. One 80m+ example lost several junior crew because of generous leave/rotation! The basic reasoning was it was expensive to spend so much time at home, all their friends were working so no one to hang out with, and it took far longer to gain the necessary sea time and experience to progress. Sometimes you cannot win!
### Be careful what you wish for.
Since 2007 (outside of shipyard construction) I have been on equal time rotation. This is a Nirvana for many but, having defended the position to the owner that the yacht requires 365-day attendance from its captain and senior team to get rotation over the threshold, you are accountable to work accordingly.
So now, during a 2-3-month roster onboard, I tend to focus completely on the yacht and my days exploring the wonderful areas I sail through are a distant memory. Crew come and go in and procession of rotational changes and although bonds are still made perhaps, they are a little weaker? That said, when they return refreshed, the faces are familiar and they quickly adapt back to life onboard without missing a beat; ensuring operational readiness, a consistent service quality, better maintenance and safety.
It could be said that with better leave and rotation means the yacht is now the place we work; it is no longer the centre of our universe and the place where we also lived our lives!
Clearly this is a much healthier balance but, occasionally, I do look back on those time long ago in sepia, when spending 11-months of the year with the same tight crew created my most memorable experiences and learning opportunities. I am open in saying my memory is grander than the reality, it was unsustainable if I wanted any sort of normal life outside of yachting. I could not have raised a family without rotation and so today I am content with a few laps around the yacht at anchor or a quick morning run on the rare times in port. My days exploring are not lost, I now have the time and freedom to return to destinations in my own time and with my family, and that is incomparable.
Done right, better leave and rotation offer crew and yacht owners many benefits and, although there are added costs, carefully planned, they are not as high as might be imagined, and there are many advantages that cannot be measured purely in monetary terms that can add value to the yacht owning experience.
In Part II Malcolm’s deep dive is where you need to go to look to the tools that you might need when structuring your own rotational plans to a yacht owner, their representative or yacht manager. The strength of your case will depend not only of the financial model, but also the quality of your reasoning and supporting facts. Without a compelling case, the yacht owner or their representatives might be thinking “living the dream, sailing the seas, working half a year and still complaining?
By |2020-11-05T12:55:57+01:00October 22nd, 2020|captains, regulations, yachtowners|
## COVD-19 Recommendations From the Healthy Sail Panel
It could be suggested there is too much information available on COVID-19 and the pandemic; including, an almost infinite number of articles and commentary on the internet, numerous Circulars and Guidance from the IMO and, publications from the International Chamber of Shipping (ICS) such as Coronavirus (COVID-19) Guidance for Ship Operators for the Protection of the Health of Seafarers (version 3.0 29th September 2020).
This excess of information can be confusing and, also as suggested in Tom Nichols book “The Death of Expertise” result in a tendency to trust in the internet to make us ‘experts’ in all manner of subjects and, resist or even ignore, advice from those with a deep understanding and experience of the subject matter, including COVID-19 – this can lead to poor outcomes.
With the absence of a collective response from the industry, it has been left to individual yacht management companies and/or captains and crew to wade through the mass of information, try to assess its quality and efficacy, and then develop and implement their own protocols and procedures in response to the virus. And, whilst some of these are well thought out and effective, others on deeper analysis, are perhaps like the ‘Swiss Cheese’ risk assessment analogy, have holes for the virus to pass through.
### Recommendations from the Healthy Sail Panel
So, it was a great relief to come across the “Recommendations from the Healthy Sail Panel.” This is the first document I have seen from a related industry with a well-researched and holistic approach to the prevention, protection and mitigation of COVID-19, in an easy to follow format.
The Healthy Sail Panel is a collaboration between Royal Caribbean Group and Norwegian Cruise Line Holdings Ltd who put together a panel of World leading experts to help inform and find a new pathway back to the “new normal” of sailing. The resulting research and recommendations are broken down into 5 key focus areas, with over 70 recommendations, many of which are applicable to yachting.
The key focus areas are: –
1. Testing, Screening and Exposure Reduction
2. Sanitation and Ventilation
3. Response, Contingency Planning and Execution
4. Destination and Excursion Planning
5. Mitigating Risks for Crew Members
COVID testing is one of the subjects with references in the footnotes. Further reading clearly highlights the value of testing for screening and diagnosis but, like the use of electronic aids to navigation, you have to be aware of the limitations, errors and accuracy.
I was certainly confused by the various tests; Rapid Antigen, PCR, Antibody, etc., their effectiveness for screening, diagnosing present and past COVID infection. The US CDC footnote reference in the Healthy Sail Panel certainly helped my understanding, along with the infographic below – found on the Nature website in their article Fast coronavirus tests: what they can and can’t do.”
##### Courtesy: Nature “Fast coronavirus tests: what they can and can’t do”
It became clear that, amongst other factors, the timeline of infection has a big effect on the various tests and why caution is required – especially with the Rapid Antigen tests that may be used by yacht crew.
### Indian Ocean and Caribbean Passage
As many yachts and crew are readying themselves for passages to the Caribbean, Indian Ocean or further afield, I thought it was also worth considering this in the context of COVID-19 and posing the following question: –
“Should you self-isolate the yacht and crew and test before departing?”
Clearly, the time taken in transit is likely a suitable quarantine period for destination arrival purposes. However, the reason I pose the question is that given that most yachts will be departing from countries/areas with high rates of infection, and crew will have been enjoying shore leave and their time in port, what happens if a crewmember is infected, but tests negative (if tested) and is asymptomatic prior to departure?
Once underway and symptoms present, not only would there be concerns of further infections amongst the crew, and medical treatment if severely affected, there would also be concerns about at the port of destination; would the port allow the yacht to berth and what are the reception and medical facilities for any infected crew?
The same goes for ‘crossing crew’ do you bring them in early and quarantine (onboard in single cabin) and test prior to departure?
Clearly, no captain wants to restrict well-earned shore leave but, then again, it is important to avoid any crewmember being infected and becoming a medical emergency and/or a vector for further transmission, especially on a long sea voyage, so it makes sense to try and prevent this outcome.
I’d be interested to know how yachts and management companies are dealing with this. Some considerations:
• What methods are in use for mitigating the risk of infection prior to departure
• Has the port authority of your arrival destination been contacted and what is their policy in the event of an infected crewmember on an arriving yacht
• Do the hospitals have the facilities and capacity to handle a COVID-19 patient
• Are there any additional medical supplies and PPE above ‘Medical Scales’ that may be recommended to carry
The above, departs slightly from the main reason for this post but, for those about to embark on a lengthy passage, it’s something worth thinking about?
As always at OnlyCaptains, or goal is to share knowledge and help inform. Hopefully, the Healthy Sail Panel offers some useful information on COVID-19 that may help with your own procedures. And, perhaps it might be used as a reference by industry associations such as MYBA, LYBRA, IYBA, in a collaborative effort to create our own yachting recommendations. These would not only be of value to captains, crew and yacht management, they would also help to instil confidence in owners and charterers through the knowledge that industry accredited measures were in place to protect them whilst onboard.
By |2021-06-14T09:38:08+02:00October 9th, 2020|captains, covid-19, environment, yachtowners|
## Measuring Yacht Efficiency – How And Why It Matters
Last week, I attended the Yacht Cub de Monaco: Capital of Yachting Experience. It was a very well organised and attended event, with some very interesting presentations and discussions.
It was also the launch of the Yacht Club de Monaco Superyacht Eco Association (SEA) INDEX. Supported by Nobiskrug and Credit Suisse, this is an important initiative with a goal to benchmark yachts in terms of their CO2 environmental performance. And, whilst there are other emissions, CO2 is by far the largest greenhouse gas (GHG) of importance and the one most visible in the public eye.
The principle is that it uses the IMO’s Energy Efficiency Design Index (EEDI) formula with a few changes to make it more specific to yachts.
The SEA INDEX is the first tool designed to assess and compare the efficiency of a yachts design and its environmental impact in terms of CO2, with a transparent and easy to understand rating system. Stars are awarded from 1 (lowest rating) to 5 (highest rating) depending on where a yacht sits above or below the rating bands relative to the baseline of sampled yachts.
Image: Courtesy of the SEA INDEX
The data from approx. 130 yachts of various length and displacement was sampled and their data entered in order to develop the initial baseline – there are now over 200 yachts.
It uses max power and speed, which may seem excessive, but a metric was required and, if you consider this as the ‘maximum emissions potential’ of a yacht, by using the same set of data points for all yachts, it provides a ‘standard’ for comparing their designs. For example, on comparable sized yachts, a more efficient hull will require less power for the same speed, and more efficient HVAC and hotel systems power management, will require smaller generators, both of which will result in reduced emissions and a higher INDEX rating.
And, as new designs and engineering innovations are introduced into yachting, the SEA INDEX will help highlight the improvements being made.
Of course, actual emissions depend on many variables that are affected by an owner and the operational profile of a yacht – these are hard to assess in any consistent or meaningful way. If we had recorded all yacht activity and consumption over the last 10 or 20 years, we would be able to draw a curve of standard deviation and have an idea of what might be described as ‘average use’ on which to make comparisons. Unfortunately, we don’t have this information, and this is perhaps the flaw in all such tools, so the only true account of a yachts CO2 emissions has to be calculated from their fuel consumed.
The factor the IMO use for CO2 emissions from MGO is 3.206, this means for every 1,000t of MGO used, 3,206t of CO2 is generated so it is easy to calculate your CO2 from fuel.
Any design efficiency gains, and improvements that can be made in the operation of the yacht, such as running at lower speed, managing power, switching off unused lighting and equipment, etc., will reduce the power required, fuel consumed and emissions.
In combination with efficiency gains, Carbon offsetting is one way to mitigate a yachts emission. Though, as I have written in a previous piece Superyacht Carbon Offsetting great care is required to select one that is fit for purpose.
But, it’s not just the amount of CO2 that is an important consideration. Looking to the future, it is very likely that shipping, like other industries, will be impacted by Market Based Mechanism’s (MBM) to drive forward the transition to a greener future, and these will have cost implications.
The IMO by 2023 will introduce their new framework for the reduction of GHG emissions from shipping and it could include a carbon tax. The EU in a recent plenary session of parliament, agreed that shipping should be included in the EU Emissions Trading Scheme (ETS) possibly in 2021and include vessels less than 5000gt. Trafigura, one of the World’s largest ship charterers, published on 25th September “A proposal for an IMO-led global shipping industry decarbonisation programme” calling for a $100 –$200 tax per ton of CO2 on shipping as the only way of driving the necessary industry change.
As further evidence of the direction of travel for CO2 emissions for business, Swiss Re made this announcement on the 15th September 2020:
“Swiss Re steps up its internal carbon levy to USD 100 per tonne as of 2021 and will gradually increase it to USD 200 per tonne by 2030”
Any such taxes or levies imposed on CO2 emissions will increase the cost of yacht ownership.
On top of that we have Environmental Governance and Sustainability (EGS) targets that are becoming ever more prevalent, especially in investment and finance. The Poseidon Principles is just one initiative, launched the 18th June 2019, “major shipping banks will for the first time integrate climate considerations into lending decisions to incentivize maritime shipping’s decarbonization” their goal is to work towards the IMO 2030 and 2050 reductions in GHG by ensuring that their loan books are aligned with those targets – finance will become harder for vessels that fail to meet efficiency improvements and GHG reductions.
Could similar lending rules apply to yachts in the future, how would that affect the value of older less efficient yachts?
Whilst it is not yet clear how taxes and regulations will be imposed in the future, what is clear, is that yachting is unlikely to escape their embrace. And our intimate connection to the sea and the environment places additional responsibility on the industry to protect the health of our oceans and planet. The SEA INDEX is the first of many important tools, including those from the Water Revolution Foundation, that will help us to understand our environmental footprint and drive the necessary change that puts us on a pathway to a sustainable superyacht industry.
Like any instrument that is reliant on data; the more yachts that participate, the more refined and accurate the SEA INDEX will become – I would call upon all Captains to get involved.
By |2021-06-14T09:38:51+02:00September 29th, 2020|captains, environment, regulations, yachtowners|
## The Captain And Yacht Owner Relationship
It is often overlooked, but the most important relationship for a successful yachting experience is that between the Captain and the Yacht Owner, or Principal Charterer. Long past the heady days when deals are signed and photos are taken with designers, brokers and shipyard owners cutting ribbons, the Captain and the Crew are tasked with delivering on the promise.
I was recently asked a question during an interview, “As a Superyacht Captain, how do you manage the expectations of an Owner?”
On the face of it, a simple question but the answer is rather more complex. Let’s think of a sample 100 metre yacht; the cost may exceed €200M and the yacht owner has waited 5 years – 2 years of development with designers and brokers, and 3 years in construction. So when their dream is finally delivered and their anticipation is heightened, how does a Superyacht Captain manage their expectations?
You cannot!
There is no way to perfectly match the expectations an Owner has built up over the years as he waits patiently for delivery day. To take it further; how should the Captain deliver bad news to this Yacht Owner? News that may reflect that the yacht does not function in the manner presented during the design, sales, purchase cycle. Or on charter, the promotional photo that shows all watersports in use, seemingly on demand, is a guest expectation that cannot be delivered; with the Captain trying to respect the legal obligation for hours of work and rest.
The honeymoon is now over and there is a risk of a breakdown in the Owner / Captain relationship, there is nobody else in the room. The photo of the ribbon cutting may be sitting in a frame or the charter brochure open on the web browser, but the actors belong to a time long-forgotten, all shortcomings are directed to the Captain.
This is a scene in which I have had a walk on role many times; as have most Captains. Standing before an unhappy Yacht Owner for an operational shortcoming that was built into the yacht with no way to address, is a humbling experience. And, as awkward as an operational ‘moment of truth’ can be, it is preferable to the personal rebuke that can’t be blamed on a technical or manning deficiency.
The Owner / Captain relationship has a sense of intimacy. The Yacht Owner spends significant time on the yacht, and the Captain is brought into their World. Many new Captains are swept up in the intoxication of being within this inner sanctum, wiser Captains maintain some separation knowing that such personal intimacy is fragile and can easily fracture – often without warning.
I recall from my own career, a time when I would greet the Principal on every arrival and departure from the yacht. This was and remains an accepted practice; one learnt from observing my former Captains, and absorbed automatically into my own Captaincy. It was some years into my time with a Yacht Owner when, during a particularly challenging conversation, he said, “and why do you meet me every time I move? Can’t I have some privacy?” It seemed such a small point but, over time, it had catalysed into a real annoyance for this exceptional Yacht Owner.
It should not have escalated to this level, but a Yacht Owner is not normally driven to address the issues of their day to their staff unless it is of a serious nature. Too often, a Yacht Captain’s success is measured only by the departing comment of the yacht owner who says, “Thank you, we had a great time.” This may be authentic or, likely the yacht owner is not ready to invest the time to deconstruct the trip at that point. Not unlike the automatic response when the ever-friendly waiter asks, “did you enjoy your meal?” The question is more rhetorical than a real enquiry of the dining experience.
I was only awakened to this cold reality when an Owner’s Representative confronted me with a concern of the Yacht Owner. I held my position that the Yacht Owner expressed gratitude and pleasure with the last visit. The Representative quickly cut me down and made clear what is said onboard is very different to the detailed debrief he received in the office some days later. It was a growth and career inflection point for me; I would no longer take for granted any Owner’s praise or make assumptions based on yachting’s normal practices.
I did not enjoy being admonished by the Owner’s Representative, but he caught what could have been a fatal rupture in an otherwise successful relationship. From that time on, we worked together to ensure the good health of the Owner / Captain relationship. I would no longer take for granted the warm smile on departure and would readily seek the ‘truth’ from my colleague in the Family Office.
OnlyCaptains seeks to support Captains and Yacht Owners through their model of Search, Select, Place and Mentor. We have lived the Owner / Captain relationship and realise it is the cornerstone of a successful yacht experience. We are the knowing advisor; able to listen, reflect and interpret the concerns of a Yacht Owner and use this insight to help coach the Captain to their success.
By |2022-10-12T15:57:23+02:00August 20th, 2020|captains, leadership, mentoring, Uncategorized, yachtowners|
## Superyachts – A Question Of Manning
When I was asked to write a piece on Minimum Safe Manning (MSM) and how it affects yacht operations for the Superyacht Report, I knew that, although an important factor, it was only one of a number of considerations used to determine the crew complement. However, what was also clear, is that many yachts do not have sufficient crew to meet the expectations and demands of their owners and guests. A point that was recently expressed in article from the International Superyacht Society (ISS) Captains Committee, where they raised concerns about fatigue and its dangers, and asked:
Why is it that manning levels that were appropriate years ago are still accepted as the norm today?
From my own experience I can empathise with this.
Some time ago I took command of a yacht owned by a lovely family with a large family residence serviced by what seemed like an inexhaustible number of staff. For them, they were used to having the most attentive service 24 hours a day and had the same expectation for the yacht. They built a beautiful yacht that could carry up to 22 passengers which, she often did, but unfortunately was manned with the same number of crew as an equivalent 12 passenger yacht. As might be expected, it created significant challenges!
Following that experience, I also had the opportunity to review three new build PYC yachts and their manning. My observation on all of them, was that there was insufficient crew, partly because PYC compared to LY3 required additional MSM numbers, which impacted on the hotel side, but also due to the number of guests carried and services expected. After delivery, two ended up building more crew cabins – imagine the expense – and one downgraded to LY3 because they could not meet the MSM requirements without negatively impacting on the interior service. Clearly, if it was so obvious to an experienced mariner, why was it not obvious to the broker, designers and the shipyard?
The suitable manning of yachts is not restricted to large yachts either; there has been numerous discussions and articles written about crew on various sizes of yacht having to be ‘creative’ with their hours of work and rest in order meet owner/guest demands and remain compliant.
I suspect that many readers who have worked on busy yachts will have all had the same experience, where the team spirit, professionalism and commitment of the officers and crew to deliver the very best experience, overrides concerns about fatigue and the effect on performance, welfare, mental health, safety and crew retention.
So how are manning levels determined and, how can they be better understood?
### Considerations
Along with the MSM (more of which below) there are other factors that normally determines the size and makeup of crew:
• Finance is an important consideration as crew expenses are amongst the highest operational costs so obviously it makes sense to optimise manning
• Manning levels on similar sized yachts are used as a comparable standard, especially applicable to production yachts
• Given the high value of the yachts ‘real-estate’ owners, understandably, will want to maximise owner/guest accommodation – the luxury spaces
• Technical, service, access and operational spaces also require a large volume
Additionally, some in the industry may be keen to gloss over crew numbers to help with a sale, they may fail to manage the owners expectations or, just do not possess the operational experience to understand the numbers needed for a particular owner and yachts operation.
Once the above factors are considered and the various spaces assigned, the crew accommodation is designed following the Maritime Labor Convention (MLC) guidelines and the number of cabins/berths can be defined. Interestingly, MLC may actually be having some unintended consequences; as one respondent – maybe controversially? – in the ISS article suggested:
What we need is more berths not more space!
### Minimum Safe Manning
A commercial yacht will require a Flag state approved MSM – many private yachts, as with other regulations, may also choose to comply on a voluntary basis.
An owner/operator will make an MSM application based on Flag guidance and the IMO Principles of Safe Manning Resolution A.1047(27). Once approved, an Administration will issue an MSM certificate, however, this is only the minimum number of crew (those requiring STCW or equivalent qualifications). This is the captain, deck/engineering officers and ratings and, cook, depending on crew numbers and Flag requirements, necessary to safely operate a yacht when it proceeds to sea:
The ship named in this document is considered to be safely manned if, when it proceeds to sea, it carries no less than the numbers grades/capacities of personnel specified in the table
This does not include the hotel team; service, housekeeping, laundry and galley, or the additional deckhands necessary to launch tenders, run the water sports, etc., or other specialists required these days – these are all additional to the MSM.
Of note is that the A.1047(27) changed from previous resolutions as follows:
A.890(21) and amendment A.955(23)
1.1.1 maintain safe navigational, engineering and radio watches in accordance with regulation VIII/2 of the 1978 STCW Convention, as amended, and also maintain general surveillance of the ship;
A.1047(27)
1.1 maintain safe navigational, port, engineering and radio watches in accordance with regulation VIII/2 of the 1978 STCW Convention, as amended, and also maintain general surveillance of the ship;
As you can see, safe manning in port was added but, so far, I have not seen any yacht specific guidelines on ‘port’ safe manning – commercial ships are normally involved in cargo operations so they tend to be more fully manned in port. In-port-manning can be a difficult issue for captains; it is often left to them to determine and they have to strike a fine balance between safely manning the yacht and providing crew valuable shore leave but, given number of incidents and fires in port, perhaps it should be better regulated? Running drills with reduced crew will help identify what is a safe number.
Often the Manning Scales provided by an Administration will be used as the standard. However, they allow some latitude on numbers based on the strength of the application and, operators can also take advantage of manning reductions allowed due to ‘distance from safe haven’ – which, for yachts, seems contrary to their operational demands?
Once the MSM has been agreed the rest of the crew can be determined – if the total number of berths is 15 and the MSM is 8, that leaves 7 berths for the rest of the team.
### Three Hundred and Sixty Degree Approach
As can be expected expect this approach produces mixed results – a bit like the ‘off-the-shelf’ budget that so often disappoints.
What is necessary a three hundred and sixty degree approach; an in-depth assessment of all the factors and how each unique owner wants to use their yacht. Only once armed with that information can you estimate the right manning levels and/or manage expectations by modelling the expected demands, peaks and crew work schedules.
The point of managing an owners expectations is key, especially in the case of production and semi-production yachts where crew accommodation/berths tend to be fixed. In these circumstances it is still important to make the assessment. This helps avoids frustration and disappointment by communicating any limitations that may surface, along with possible solutions, such as use of external laundry services, shore-based crew, or shadow boat, at the earliest stage to an owner.
Yes, the yacht can operate with these crew numbers but, the service onboard will be limited in these areas…is that what you want?
Making a proper assessment requires effort and collaboration; asking questions, getting to know an owner, how they expect to use the yacht and the style and depth of services that are important to them.
### YACHT B
• Likes quiet time with wife and one or two guests • Meal times, silver service and large and varied selection
• Rises late goes to bed early • Has boat full of family and friends
• Likes to be in port as often as possible • Likes to party and stay out late
• Eats very light diet and at strict times • Loves to be at anchor
• Guests have to follow his rules • Some guests rise early late, others rise late and bed late – no rules set for guests
• Wants very light touch and informal service • Love water sports, all the toys setup and available
• Happy to help themselves • Tender rides for sightseeing, shopping trips, etc.
• Doesn’t want fuss • Wants a masseuse available
• Just love being on the yacht • Expects crew to look after children
• Wants formal service at all times – loves the attention and show
• Will not help themselves and expects stewardess on call 24/7
• Often invites friends over for drinks/meals at short notice
On both (A) and (B) the normal crew complement was 19. The manning on (A) worked well, but on (B) we were unable to deliver and maintain the standards of service expected and without being non-compliant. Fortunately, the owner was understanding and pragmatic and, after detailing the issues and possible solutions, it was agreed that we would use two guest cabins for 4additional crew that allowed us to provide the level of service that was important to him. Later, the the yacht was modified and 2 additional crew cabins (4 berths) were added at considerable expense.
Understanding use and gathering information similar to the above example will help to determine the appropriate manning levels, especially during those important peak times in guest operation, and allow you to develop work schedules for all crew and each department. It may need several iterations and some finessing to get right but this is a crucial exercise as it provides the information necessary to have a meaningful discussion about manning with an owner.
### Operational vs. Standby
Unlike a commercial ships where workload and manning is more easily determined and manage accordingly, yachts are a much more difficult and, not just because of different owners demands and expectations but also the seasonality and operational profile.
Many yachts, apart from shipyard periods, operate all year round, on standby for visits at the drop of a hat. These tend to be larger yachts and so full manning required can more easily be justified.
Smaller, or one season yachts, are a more complex situation. Whilst it might be essential to have 19 crew during the season, it may be difficult to justify that number sitting in port for the winter with no guest movements where a more appropriate number might be 12 i.e. sufficient to safely man and maintain the yacht in good order. And, if that choice was made, at least you have the berths necessary to increase crew for the season; though it should be noted it is easy to downsize a crew but, much more difficult to upscale again and expect the same quality of crew, personalisation, level of service, operation and safety standards.
Importantly, manning levels should be determined by the peak periods of operation; after all, that is when an owner or charter guest gets to experience the depth and quality of service.
### Superyachts Today
In my time I have seen the whole industry evolve and so many positive changes have taken place.
Today, yachts are better built, more reliable, safer, officers and crew better qualified and trained, employment conditions improved, and there is now much better support available from yacht management and other shore-based service providers. At the same time, there has also been an incremental increase in owners expectations – some examples below: –
• Yachts and guests now rely heavily on electrical/electronic and AV/IT systems
• Beach clubs’ add another deck to be servced
• SPA therapists, hairdressers, gym instructors, nurses, nannies, are now routinely carried – are they single or dual role? Whatever the case, it generally means service and housekeeping are stretched as they lose a member to other activities
• Every night is ‘theme night’ with new table decorations and service expectations
• Photograph/video guest experience and provide a personal record for guests to go home with
• Flight crew, security and owners staff can add to numbers carried and place their own demands on crew
• Tenders are bigger, requiring more crew to launch and operate
• More toys carried like inflatable slides -heavy and labour intensive to setup/breakdown, especially when wet! – an ever-expanding list of toys, diving equipment, motorcycles, etc. – all require crew and maintenance
• Diving, Pilates, jetski, sailing, windsurf, kite surf…an almost endless list of activities
• Accommodation for river or ice pilots for yachts traveling further afield
These are further compounded by an increase in paperwork that is a fact of modern yachting e.g. budgets, purchase and approvals, crew HR functions, maintenance and refit planning, safety management systems, and management reporting – this generally falls on the shoulders of the captain and senior crew. One study on a 100m+ showed that the captain was spending 33% his time on their management companies demands which, along with their normal duties and responsibilities, was clearly unsustainable.
Whilst there has been some positive changes in the industry that should be celebrated, the evidence suggests that manning levels maybe one element that has not profited from the evolutionary process.
Perhaps yacht crew are partly to blame for this due to yachting culture, as already posited, where they will work all hours necessary to deliver the very best experience for owners and guests, and often do so without complaint or communicating the problem outside of the yachts team. And, apart from this cultural norm, there are also undeniable concerns about job security where captains and crew may be reluctant to speak-up and/or report their hours of work and rest accurately for fear of losing their job. However, it is important as proper reporting helps to educate owners and the wider industry. Furthermore, if there was an incident and an inquiry, if falsification of hours of work were discovered and fatigue the root cause or contributing factor, it could have serious consequences for the crew, especially the captain.
### Conclusion
The quality of captain, officers and crew and, the onboard experience is, without doubt, key to the success of a superyacht and this can only be achieved with the right manning levels which, unfortunately, have not kept pace with the advances made in the rest of the industry.
As the ISS piece stated ‘for the love of yachting’ we need to have an honest conversation about manning that includes owners and all industry stakeholders, especially those with operational experience. Getting this right improves the health and well-being of the crew, their performance, retention, yacht safety and, ultimately, leads to a better ownership experience.
By |2022-10-12T15:57:38+02:00July 24th, 2020|captains, Managment, Operations, regulations, Safety, Uncategorized, yachtowners|
## Superyacht – The Art Of The Budget
Whenever I talk to owners and their teams, the subject of running costs and budget always comes up. I always advise, it is a fundamental tool for measuring the financial performance of the yacht but, like fine art, requires careful crafting and curation to be of value, and this always comes with a caveat – there is no ‘one size fits all’ model. That “10% of the value of the yacht” as often cited, can turn out to be a significant underestimation that can lead to financial shock and a negative ownership experience; with some owners withdrawing from the industry because of it.
There is no ‘one size fits all’ model
The cost of running a Superyacht is significant, with annual costs ranging from €2M for a 50 metre yacht, and up to €20M+ for some of todays Gigayachts. And, with such significant expenditure it is essential to have financial controls in place, and a well formulated, approved and monitored budget is one of the most valuable tools available.
A budget must; forecast the amount and timing of funds, measure performance and instill accountability and transparency into the fiscal management of the yacht.
A realistic budget takes time and effort to develop. The schedule of accounts must reflect the expenditure accurately and, as mentioned, this is unlikely to be achieved from ‘an off the shelf budget’ for an identical or similar sized yacht without adapting it to the owner and use.
The process of developing a budget requires proactive collaboration and consultation between the captain, the yachts team, and the owner, his family office, and/or management company. It will be important to understand how the yacht is to be used as this knowledge will help with the accuracy of the budget.
The process of developing a budget requires proactive collaboration
Knowing the cruising plans and use of the yacht e.g. one or two seasons, stand-by or scheduled use, crew employment terms and conditions, standard of maintenance, along with preferences for economy or speed, marina or anchorage, food and drink, etc., will help in creating a workable budget. There is also the question of private or charter, which although adds income to the yacht – not guaranteed and often over estimated – also has cost implications; extra hours on engines and systems, general wear and tear and crew issues.
The Head’s of Departments (HOD’s) – engineering, deck, interior and catering – should be involved in the development process and should have responsibility for managing their departmental budgets. This helps improve the accuracy of the budget, and serves as a motivational tool by giving senior crew ownership and accountability of their area of expertise.
As yachting is perhaps, the ultimate discretionary expense, and a big part of its appeal is the freedom and spontaneity it affords, one should understand that the budget is subject to many variances, some which can be significant depending on how plans change. In addition a yacht is made up of complex systems and equipment and operates in a hostile environment. This will inevitably result in breakdowns or incidents that cannot be readily modeled into the budget, other than trying to mitigate a potential shortfall by maintaining a contingency for unexpected events.
During the life of the yacht, the reality is that repair and maintenance costs will increase. A new yacht in its first year is covered by shipyard warranty, so associated repair costs tend to be low – although beware of the travel and subsistence costs that may be levied as these can be high if there is a large amount of work carried out remote from the shipyard – in later years, these costs will progressively increase as the operating hours take their toll on equipment, systems and machinery.
Future expenses that I would categorise as Periodic Maintenance, such as dry docking and shipyard periods should also be considered. A Private or Commercial Yacht 12 PAX or less, will require two dry-docks in a five year cycle for works such as – Class survey, antifouling paint, checking and maintenance of shafts, stabilisers, rudders, bowthruster, anchors and cables, hull and ships side valves. It is also likely that the hull and/or superstructure may need a repaint within that period, again a cost that should be budgeted for. The cost of servicing engines and generators – excluding the normal checks and oil/filter changes – is often something that is overlooked and is dependent on use and hours. As an example a service contract by one engine manufacturer for maintaining 2 x 300kW engines over 16,000 hours was around €450k, and 2 x 3600kW engines over 12,000 hours was in excess of €550k.
Periodic Maintenance costs are cyclical and spread over a number of years and there are a number of ways of accounting for these. An owner should decide if he wants he to spread these over a 5 or 10 year cycle, or whether he would prefer each year to be independent, with Periodic Maintenance added separately.
An owner should decide if he wants he to spread these over a 5 or 10 year cycle
Capital expenditure for new equipment and/or upgrades should also be accounted for as a separate category as it falls outside the normal operational expenses of the yacht.
Following good accounting practices there should be sufficient cost centres, sub-catagories and account codes – the metrics – to enable a thorough analysis of expenditure. For example with suitably defined crew costs, the budget could be used to highlight and identify the real cost of high crew turnover by spikes in recruitment fees, uniform, repatriation/travel costs, etc., and provide the financial imperative to resolve the situation. Lumping costs together limits transparency and value of the budget and should be avoided.
Inevitably the budget will go through a number of versions as it is developed, reviewed and finessed, before finally approved by an owner. And, once implemented, the budget will need to be effectively monitored to ensure the defined financial targets are being met and any variances are brought to the owner’s attention without delay.
The budget is an important aid but, is only part of the picture, it must also be backed up with other controls and procedures in order to effectively manage the yachts finances. These include such things as format and frequency of reporting and auditing, purchase order request and approval process, and setting expenditure limits and authority.
As many of the suppliers and service providers we rely on in the industry tend to be small businesses, the effect of delays in the payment cycle can be profound. And, for the yacht, it can create reputational damage – you end up being at the back of the queue or, ignored completely, for services and supplies which, in high season, can impact on the owner and guest experience. Having a budget that effectively forecasts cash flow can ensure funds are available to make prompt payments – although sometimes, unfortunately, slow payment is the policy of an owner or his financial team.
Finally, it should be understood that the budget is a dynamic document and will need to be continuously reviewed and improved upon over time, and changed as circumstances dictate. If crafted and curated well, the budget provides an owner with a valuable tool in understanding and controlling costs, minimising financial shock and, improving the ownership experience.
By |2021-06-14T09:43:38+02:00February 1st, 2020|captains, Finance, Managment, Operations, yachtowners|
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# The members of a club were asked whether they speak Cantonese, Mandari
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The members of a club were asked whether they speak Cantonese, Mandari [#permalink]
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01 Jul 2018, 21:50
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Question Stats:
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The members of a club were asked whether they speak Cantonese, Mandarin and Japanese. 100 said that they spoke Cantonese, 150 said that they spoke Mandarin and 200 said that they spoke Japanese. 120 said that they spoke exactly two of the three languages. How many members does the club have?
(1) There are twice as many members who speak none of the languages as there are who speak all three languages.
(2) Half of the members who speak Japanese and Cantonese also speak Mandarin.
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Re: The members of a club were asked whether they speak Cantonese, Mandari [#permalink]
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01 Jul 2018, 22:30
Bunuel wrote:
The members of a club were asked whether they speak Cantonese, Mandarin and Japanese. 100 said that they spoke Cantonese, 150 said that they spoke Mandarin and 200 said that they spoke Japanese. 120 said that they spoke exactly two of the three languages. How many members does the club have?
(1) There are twice as many members who speak none of the languages as there are who speak all three languages.
(2) Half of the members who speak Japanese and Cantonese also speak Mandarin.
Since we have many move variables than equations, we'll trying testing easy numbers
This is an Alternative approach.
We'll first start by assuming that the 120 people who spoke 2 languages are split evenly between the pairs. That is 40 spoke Mandarin and Chinese, 40 spoke Mandarin and Japanese and 40 spoke Japanese and Cantonese.
(1) say 0 members spoke all 3 languages. Then 100 - 80 = 20 spoke only Cantonese, 150 - 80 = 70 only Mandarin and 200 - 80 = 120 only Japanese and we can finish calculating to get (only one language) + (exactly two languages) = (20+70+120) + (120) total number of people.
Say 10 members spoke all 3. Then 20 spoke none. so 100 - 80 - 10 = 10 spoke only Cantonese, 150 - 80 - 10 spoke only Mandarin and 200 - 80 - 10 spoke only Japanese.
If we're careful, we'll notice that we've added and subtracted the same number of people: we've subtracted 30 people from the (only one language) group, added 10 to the (all three languages) group and added 20 to the (no languages group). So our total hasn't changed.
Moreover, this always happens - if x is the number who speak all three than we subtract x from each of the single languages, meaning we subtract 3x total but then add back x for all 3 languages and 2x for no languages.
Sufficient.
(2) Based on (1), we know it is critical to know how many people speak 0 languages. Since we currently have no information on this at all, (2) cannot be sufficient.
Insufficient.
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The members of a club were asked whether they speak Cantonese, Mandari [#permalink]
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01 Jul 2018, 22:42
Bunuel wrote:
The members of a club were asked whether they speak Cantonese, Mandarin and Japanese. 100 said that they spoke Cantonese, 150 said that they spoke Mandarin and 200 said that they spoke Japanese. 120 said that they spoke exactly two of the three languages. How many members does the club have?
(1) There are twice as many members who speak none of the languages as there are who speak all three languages.
(2) Half of the members who speak Japanese and Cantonese also speak Mandarin.
$$C = 100 =C_o+CM+CJ+CMJ$$
$$M = 150 =M_o+MJ+CM+CMJ$$
$$J = 200 =J_o+CJ+MJ+CMJ$$..
$$CM+MJ+CJ=120$$
where $$C_o$$ = speaking only Cantonese
$$CM$$,$$MJ$$,and $$CJ$$ = speaking two languages
$$CMJ$$= speaking all languages
total members = $$C_o+M_o+J_o+CM+MJ+CJ+CMJ+None=C+M+J-(CM+MJ+CJ)-2(CMJ)+None=100+150+200-120-2(CMJ)+None=320-2(CMJ)+None$$ ....
so it will depend on number of people speaking all three and number of people not speaking at all
(1) There are twice as many members who speak none of the languages as there are who speak all three languages.
At the first look one may feel nothing, BUT it talks of two things - all 3 and None- and we are looking for these two only
so None $$= 2*CMJ$$
Total = $$320-2(CMJ)+None=320-2(CMJ)+2(CMJ)=320$$
sufficient
(2) Half of the members who speak Japanese and Cantonese also speak Mandarin.
Not what we are looking for
insuff
A
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1) Absolute modulus : http://gmatclub.com/forum/absolute-modulus-a-better-understanding-210849.html#p1622372
2)Combination of similar and dissimilar things : http://gmatclub.com/forum/topic215915.html
3) effects of arithmetic operations : https://gmatclub.com/forum/effects-of-arithmetic-operations-on-fractions-269413.html
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Re: The members of a club were asked whether they speak Cantonese, Mandari [#permalink]
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01 Jul 2018, 23:30
After sorting all the data, what we need is CMJ and none.
(1) There are twice as many members who speak none of the languages as there are who speak all three languages.
I think twice as many members who speak none of the languages as there are who speak all three languages means 2(none)=CMJ
= -2CMJ+none
=-2CMJ+(CMJ/2)....again we need CMJ value...which we don't have....
so Insufficient
(2) Half of the members who speak Japanese and Cantonese also speak Mandarin.
we don't have JC value so we don't get any thing.
so Insufficient.
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Re: The members of a club were asked whether they speak Cantonese, Mandari [#permalink]
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01 Jul 2018, 23:36
1
mahi816 wrote:
After sorting all the data, what we need is CMJ and none.
(1) There are twice as many members who speak none of the languages as there are who speak all three languages.
I think twice as many members who speak none of the languages as there are who speak all three languages means 2(none)=CMJ
= -2CMJ+none
=-2CMJ+(CMJ/2)....again we need CMJ value...which we don't have....
so Insufficient
(2) Half of the members who speak Japanese and Cantonese also speak Mandarin.
we don't have JC value so we don't get any thing.
so Insufficient.
hi
your inference of coloured portion is not correct..
it is easy to get confused in these wordings but ask yourself WHAT IS MORE?
Quote:
twice as many members who speak none of the languages as there are who speak all three languages means 2(none)=CMJ
this means None is more..
twice as many members X as twice as members Y..
so X is greater ... so it cannot be y=2x, here y becomes greater
so x=2y
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3) effects of arithmetic operations : https://gmatclub.com/forum/effects-of-arithmetic-operations-on-fractions-269413.html
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Re: The members of a club were asked whether they speak Cantonese, Mandari [#permalink]
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02 Jul 2018, 11:29
Going with A.
(1) There are twice as many members who speak none of the languages as there are who speak all three languages.
Total Members = A+B+C - (Sum of Exactly 2 Languages) - 2* All Languages + Neither of the languages.
Since Neither of the languages = 2* All Languages we have no unknowns.
Sufficent
(2) Half of the members who speak Japanese and Cantonese also speak Mandarin.
All Languages & Neither of the languages are unknowns.
Insufficent
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Re: The members of a club were asked whether they speak Cantonese, Mandari [#permalink]
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02 Jul 2018, 14:12
Total = J+C+M - 2 * All Languages - (Sum of Exactly 2 Languages) + Neither of the languages.
We know J, C M and people who spoke exactly 2 languages
1. Neither = 2* All Languages
Sufficient
2. we don't know the count of people who Speak Japanese and Cantonese.
Insuff
A
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Re: The members of a club were asked whether they speak Cantonese, Mandari [#permalink]
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06 Jul 2018, 23:55
(A)
i---->exactly one, ii--->exactly two, iii--->exactly three, n--->none
Given, ii=120
So,we have, i+2ii+3iii=450 ----> eq.1
i+ii+iii+n=Total----> eq.2
From (1)-->n=2iii
Putting the value of n in eq.2 and equating with eq.1 will give Total = 330 ----->Sufficient
From (2)--->Many unknown entities, yet -------->Insufficient
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https://brilliant.org/discussions/thread/jee-advanced-contest-16/ | ×
# JEE-Advanced Maths Contest '16
Hello, guys!
This contest is the first JEE contest on Brilliant. The objective of this game is to get well prepared for JEE-Advanced 2016 preparation having fun as well. There is so much to learn from each other, and the contest is an approach to accomplish the same. Each Brilliant user is invited to participate in the contest under the following rules:
1. I will start by posting the first problem. If there is a user solves it, then (s)he must post a new one.
2. You may only post a solution of the problem below the thread of problem and post your proposed problem in a new thread. Put them separately.
3. Please make a substantial comment.
4. Make sure you know how to solve your problem before posting it. In case there is no one can answer it within 24 hours, then you must post the solution, and you have a right to post another problem.
5. If the one who solves the last problem does not post his/her problem after solving it within a day, then the one who has a right to post a problem is the last solver before him/her.
6. The scope of questions is only what is covered under JEE-Advanced syllabus. If you are unaware of the syllabus cover, You can check out the information brochure.
7. You can use tricks/short methods/specific cases to post the solution of a problem only if they are logically valid.
8. In the case of any argument or disagreement among the solvers, the decision/judgement is passed to me.
9. DO NOT ask the answer to the problem. Just post your detailed solution solution along with the answer. It will be highly helpful to gain confidence in your problem solving and rock in JEE.
10. Proof problems are not allowed.
11. You can post a problem only from Maths section.
• Please write the detailed solutions to the problems.
Format your post is as follows:
SOLUTION OF PROBLEM xxx (number of problem) :
[Post your solution here]
PROBLEM xxx (number of problem) :
[Post your problem here]
Please try to post problems from all the spheres of JEE syllabus and share this note so that maximum users come to know about this contest and participate in it. (>‿◠)✌
Note by Sandeep Bhardwaj
5 months, 3 weeks ago
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Here is the first problem for the inauguration of the contest. It's an easy problem. All the best!
Problem 1:
In a sequence of independent trials, the probability of success in one trial is $$\frac 14$$. Find the probability that the second success takes place on or after the fourth trial.
Ritu Roy has solved this problem at the first place and provided the solution. Thanks! · 5 months, 3 weeks ago
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Solution of problem 1
The required probability is
$$=_{ 1 }^{ 3 }{ C }.\frac { 1 }{ 4 } { .\left( \frac { 3 }{ 4 } \right) }^{ 2 }.\frac { 1 }{ 4 } \quad +\quad _{ 1 }^{ 4 }{ C }.\frac { 1 }{ 4 } { .\left( \frac { 3 }{ 4 } \right) }^{ 3 }.\frac { 1 }{ 4 } \quad +\quad _{ 1 }^{ 5 }{ C }.\frac { 1 }{ 4 } { .\left( \frac { 3 }{ 4 } \right) }^{ 4 }.\frac { 1 }{ 4 } \quad +\quad ...\infty \\ =\frac { 9 }{ 256 } .24\\ =\boxed { \frac { 27 }{ 32 } }$$ · 5 months, 3 weeks ago
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How did we get that 24? I used the reverse probability method 1 - 3C2.1/4.1/4.3/4 - 3C3.1/4.1/4.1/4 = 27/32 · 5 months ago
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Problem 10 :
In $$\Delta \text{ABC}$$, $$\text{AB} = \tan^{-1}\left(\sin \left(\sqrt{2} \right) \right)$$ and $$\tan \left(\dfrac{\text{A}}{2} \right) = \ln(\pi) \tan \left(\dfrac{\text{B}}{2} \right)$$
Then the vertex $$\text{C}$$ lies on
a) Ellipse
b) Parabola
c) Hyperbola
d) Straight Line · 5 months, 3 weeks ago
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@Aditya Kumar
I see that you've posted the next problem of contest i.e. Problem 11, but there is no solution of 10th problem by you. Can you clarify on this? · 5 months, 1 week ago
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I had posted the solution! Some careless mod has deleted it! I can't believe it. · 5 months, 1 week ago
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@Aditya Kumar ,your solution was incorrect. · 5 months, 1 week ago
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Ooops, sorry for that! I don't know who did that.
Can you please post that again? · 5 months, 1 week ago
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$\dfrac{\tan(A/2)+\tan(B/2)}{\tan(A/2)-\tan(B/2)}=\dfrac{\ln \pi+1}{\ln \pi-1}=T~(Let)$
$\implies \dfrac{\sin(\frac{A+B}{2})}{\sin(\frac{A-B}{2})}=T$
$\implies \sin C=T(\sin A-\sin B)$ $\implies a-b=\dfrac{c}{T}=\text{Constant}<c$ Here $$a,b,c$$ denote sides opposite to angles $$A,B,C$$ respectively.. A hyperbola..... Is it? · 5 months, 3 weeks ago
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@Ishan Singh
Please reply to Rishabh's comment. · 5 months, 1 week ago
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Rishabh's solution is correct (I had stated it earlier). Aditya's solution was incorrect. · 5 months, 1 week ago
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Problem 45
The coefficient of $$x^{n-6}$$ in the expansion:
$$n! \times \ [ \ x \ - \frac{\binom{n}{0} \ + \binom{n}{1}}{\binom{n}{0}} \ ] \ [ \frac{x}{2} \ - \frac{\binom{n}{1} \ + \binom{n}{2}}{\binom{n}{1}} \ ] \ .... \ [ \frac{x}{n} \ - \frac{\binom{n}{n-1} \ + \binom{n}{n}}{\binom{n}{n-1}} \ ]$$
is equal to $$\binom{x}{y} \times \ z^y$$
Find x,y,z if all are integers( x, y and z can be in terms of $$n$$ )
Sarvesh Nalawade has provided a complete solution to the problem. · 5 months ago
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Let S = $$n! \prod_{i=1}^{n} ( \frac{x}{i} - \frac{{n \choose i-1} + {n \choose i}}{{n \choose i-1}})$$
$$Therefore, S= n! \prod_{i=1}^{n} ( \frac{x}{i} - \frac{{n+1 \choose i}}{{n \choose i-1}} )$$
$$S = n! \prod_{i=1}^{n} ( \frac{x}{i} - \frac{n+1}{i} )$$
$$Therefore, S = (x-n-1)^{n}$$ .
Co-efficient of $$x^{n-6} = {n \choose 6} (n+1)^{6}$$
Therefore x=n , y=6, z= n+1 · 5 months ago
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You are required to find the individual values of $$x$$ , $$y$$ and $$z$$, not the sum ,although it is correct. You may post the next problem after posting the solution. · 5 months ago
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Don't use the variable x for two purposes in the same question. · 5 months ago
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Problem 41
$$\displaystyle \int tanx. tan2x. tan3x\text{ }\,dx$$
Saarthak Marathe has posted the solution to the problem.Thanks! · 5 months ago
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$$\displaystyle tan3x=\frac{tan2x+tanx}{1-tanx.tan2x}\\ tanx.tan2x.tan3x=tan3x-tanx-tan2x$$
Now integrating we get,
$$\displaystyle \int tanx.tan2x.tan3x.dx=\frac{ln|sec3x|}{3}-\frac{ln|sec2x|}{2}-ln|secx|+constant$$ · 5 months ago
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Correct!Post the next question. · 5 months ago
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Problem 36:
Let $$a$$ be a positive real number such that $$a^3 = 6(a + 1)$$ then, find the nature of the roots of $$x^2 + ax + a^2 - 6 = 0$$.
Both Mayank Chaturvedi and Vighnesh Shenoy have provided complete solution this problem. Thanks! · 5 months, 1 week ago
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A graphical approach.
We have to see the nature of discriminant
$${ a }^{ 2 }-(4{ a }^{ 2 }-24)\\ or\quad 8-{ a }^{ 2 }\\ Now,\quad graph\quad of\quad { a }^{ 3 }-6a-6=f(a)\quad \\ takes\quad two\quad turns\quad at\quad a\quad =\sqrt { 2 } \quad and\quad -\sqrt { 2 } ,\quad \\ which\quad shows\quad a(root\quad of\quad function)\quad is\quad positive\quad and\quad at\quad least\quad \sqrt { 2 } \\remember\quad f(x)\quad is\quad continuous.\\ at\quad a=\sqrt { 8 } \quad the\quad f(a)\quad is\quad negative.\\ So\quad root\quad of\quad f(a)>\sqrt { 8 } .\quad \\ Hence\quad for\quad equation\quad { a }^{ 3 }-6a-6=0,\\ a>\sqrt { 8 } ;{ a }^{ 2 }>8\\ We\quad have\quad 8-{ a }^{ 2 }<0.\quad so\\the \quad roots\quad are\quad non\quad real$$ · 5 months, 1 week ago
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A non-calculus approach.
$${a}^{3}-6a-6=0$$
Let $$a=b+2/b$$
Therefore,$${ \left( b+2/b \right) }^{ 3 }-6(b+2/b)-6=0$$
Simplifying we get that, $${b}^{6}-6{b}^{3}+8=0$$
Therefore, $${b}^3=4$$ or $$2$$
Substitute these values to get $$a$$.
That time we see that only one real solution of $$a$$ occurs which is, $$a={2}^{1/3}+{2}^{2/3}$$
We see that, $${a}^{2}-6=6/a$$
Substituting this value in $${x}^{2}+ax+{a}^{2}-6=0$$ we get that,
$$a{x}^{2}+{a}^{2}x+6=0$$
Assume that the roots of these quadratic equation are real, Then using formula for roots for quadratic equations,
$$x=\dfrac { -a\pm \sqrt { { a }^{ 2 }-24 } }{ 2 }$$
Then substituting the acquired value of $$a$$ in this equation we get that $$x$$ is a complex number. Hence, our assumption was wrong. · 5 months, 1 week ago
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Wondering, how did you thought of that a=b+(2/b). · 5 months, 1 week ago
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One way of solving cubic equation of the type $$ax^3+bx+c=0$$ is to take $$x=d+y/d$$ and manipulate the value of $$y$$ to get a solvable $$6th$$ degree equation in $$d$$ · 5 months, 1 week ago
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By solvable, do you mean quadratic type equations with higher degrees? · 5 months, 1 week ago
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yes · 5 months, 1 week ago
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Great!!! · 5 months, 1 week ago
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$$\Delta = (a)^{2} -4(a^{2}-6) = 24-3a^{2} = 3(8-a^{2})$$
Consider,
$$f(a) = a^{3} -6a - 6$$
$$f'(a) = 3a^{2} - 6 = 3(a^{2}-2)$$
For $$0 \le a \le \sqrt{2}$$ , f(a) is decreasing, increasing for $$a \ge \sqrt{2}$$
$$f(0) = - 6 < 0$$
$$f(\sqrt{2}) = 2\sqrt{2} -6\sqrt{2} - 6 < 0$$
$$f(\sqrt{8}) = 8\sqrt{8}-6\sqrt{8} - 6 = 2\sqrt{8} - 6 < 0$$
Thus, the positive root of $$f(a)$$ is $$\ge \sqrt{8}$$
$$a \ge \sqrt{8}$$
$$\Delta < 0$$
Thus, the roots are not real. · 5 months, 1 week ago
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Just completed solving the question and here you post the solution! But I think proof questions are not allowed, isn't it? · 5 months, 1 week ago
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I am changing the wording of the question ,as suggested by @Vighnesh Shenoy. @Vighnesh Shenoy and @Mayank Chaturvedi,please make changes in your solutions accordingly. · 5 months, 1 week ago
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Oh yes. · 5 months, 1 week ago
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I guess he should have asked if the roots were real or complex. · 5 months, 1 week ago
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Mayank should post the new question. · 5 months, 1 week ago
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OK. @Mayank Chaturvedi,please post the next question · 5 months, 1 week ago
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Problem 25 :
If $$p$$ is an odd prime number, then $$\lfloor ( 2 + \sqrt{5})^{p} \rfloor - 2^{p+1}$$ is always divisible by :
$$1) 2p$$
$$2) 3p$$
$$3) p+1$$
$$4) 5p$$
Vighnesh Shenoy has solved this problem at the first place and provided the solution. But feel free to share new approaches. Thanks! · 5 months, 2 weeks ago
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$$(2+\sqrt{5})^{p} + (2-\sqrt{5})^{p} \le (2+\sqrt{5})^{p} \le (2+\sqrt{5})^{p} + (2-\sqrt{5})^{p} + 1$$
Now,
$$(2+\sqrt{5})^{p} + (2-\sqrt{5})^{p} \in I$$
$$(2+\sqrt{5})^{p} + (2-\sqrt{5})^{p} + 1 \in I$$
$$\therefore \lfloor (2+\sqrt{5})^{p} \rfloor = (2+\sqrt{5})^{p} + (2-\sqrt{5})^{p}$$
$$S(p) = \lfloor (2+\sqrt{5})^{p} \rfloor - 2^{p+1} = (2+\sqrt{5})^{p} + (2-\sqrt{5})^{p} - 2^{p+1}$$
$$\therefore S =2\displaystyle \sum_{r=0}^{\frac{p-1}{2}}\dbinom{p}{2r}2^{p-2r}5^{r} - 2^{p+1}$$
$$\therefore S = 2^{p+1} + \displaystyle 2\sum_{r=1}^{\frac{p-1}{2}}\dbinom{p}{2r}2^{p-2r}5^{r} - 2^{p+1} = \displaystyle 2\sum_{r=1}^{\frac{p-1}{2}}\dbinom{p}{2r}2^{p-2r}5^{r}$$
Clearly, $$S(p)$$ is divisible by $$2$$ and $$5$$
$$S(p) = 2\displaystyle \sum_{r=1}^{\frac{p-1}{2}}\frac{p}{2r}\dbinom{p-1}{2r-1}2^{p-2r}5^{r}$$
Now since p is a prime number, $$gcd(r,p) = 1 , r \in \left[1,p-1\right]$$
Therefore, $$S(p)$$is divisible by p.
Since $$S(p)$$ is divisible by $$2 , p ,5$$ it is divisible by $$2p, 5p$$
$$S(5) = 1300$$
$$S(5)$$ is not divisible by $$15 = 3\cdot5$$ and is also not divisible by $$6 = 5 + 1$$
Thus,
$$S(p)$$ is not always divisible by $$p + 1$$ and $$3p$$
The correct options are $$1$$ and $$4$$ · 5 months, 2 weeks ago
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Problem 8: Find the locus of centers of the circles which touch the two circles
$${x}^2+{y}^2={a}^2$$ and $${x}^2+{y}^2=4ax$$
externally.
Akul Agrawal has solved this problem in the first place and posted the solution. Thanks! · 5 months, 3 weeks ago
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Difference of distance of center of touching circle from the two given circles is constant. Hence equation will be hyperbola with (0,0) and (2a,0) as focii. Vertex is (a,0). difference between distance of center from focii is 2a-a=a.
Hence locus is
$\frac { { \left( x-a \right) }^{ 2 } }{ { \left( \frac { a }{ 2 } \right) }^{ 2 } } -\frac { { y }^{ 2 } }{ { \left( \sqrt { 3 } \frac { a }{ 2 } \right) }^{ 2 } } =1$ · 5 months, 3 weeks ago
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Problem 4:
If $$n \in N$$, evaluate the value of
$\dbinom{n}{0} + \dbinom{n}{4} + \dbinom{n}{8} + \ldots ,$
where $$\dbinom{n}{r} =\dfrac{n!}{r!(n-r)!}$$.
Akul Agrawal is the first person to solve this problem and provide the solution. Thanks! · 5 months, 3 weeks ago
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$$\displaystyle (1+x)^n = \sum_{r=0}^{n} \dbinom{n}{r} x^r$$
$$1^{m} + (-1)^{m} + i^{m} + (-i)^{m} = 4 , m = 4k,$$ else it is equal to $$0$$
Putting $$\displaystyle x=1, -1, i, -i$$ and adding, we have,
$$\displaystyle \sum_{r=0}^{\infty} \dbinom{n}{4r} = \dfrac{(1+i)^n + (1-i)^n +2^n}{4}$$ · 5 months, 3 weeks ago
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$$\frac { { 2 }^{ \frac { n }{ 2 } +1 }\cos { \frac { n\pi }{ 4 } } +{ 2 }^{ n } }{ 4 }$$
put i, -i,1, -1 in expansion of (1+x)^n and add · 5 months, 3 weeks ago
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Problem 3:
Let $$f$$ be a twice differentiable function, such that $$f''(x)=-f(x)$$ and $$f'(x)=g(x)$$ , $$h(x)=[f(x)]^2+[g(x)]^2$$. Given that $$h(5)=11$$, evaluate $$h(10)$$ .
Vighnesh Shenoy has solved this problem at the first place and provided the solution. Thanks! · 5 months, 3 weeks ago
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$$f''(x) = -f(x)$$
$$f'(x) = g(x)$$
$$f''(x) = g'(x) = -f(x)$$
$$h(x) = (f(x))^{2} + (g(x))^{2}$$
Differentiate,
$$h'(x) = 2 \cdot \left( f(x)f'(x) + g(x)g'(x) \right)$$ $$h'(x) = 2 \cdot \left( f(x)g(x) + g(x)(-f(x)) \right) = 0$$
Thus, $$h(x)$$ is a constant.
$$h(x) = h(5) = 11$$ for all x. · 5 months, 3 weeks ago
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Problem 2:
Which real values of $$k$$ exist such that the following system of equations has no solution? $\begin{cases} (k + 1)x + 8y = 4k \\ kx + (k + 3)y = 3k − 1 \end{cases}$
Nihar Mahajan has solved this problem at the first place and has posted the solution. Thanks! · 5 months, 3 weeks ago
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For the equations to have no solution, they should be parallel lines, hence their x-y coefficients are in proportion but not in proportion when ratio of the constant terms is included.
$\dfrac{k+1}{k} = \dfrac{8}{k+3}\neq \dfrac{4k}{3k-1}$
First solving the quadratic from $$\dfrac{k+1}{k} = \dfrac{8}{k+3}$$ we have $$k=1,3$$. However when $$k=3$$ are substituted in $$\dfrac{4k}{3k-1}$$ the ratio does not remain consistent. Hence, $$k=3$$ is the solution and number of solutions is $$1$$.
(Feel free to correct me) · 5 months, 3 weeks ago
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Problem 47 : In a $$\Delta ABC$$ the ratio of side $$BC$$ and $$AC$$ to the circumradius is $$2$$ and $$\dfrac{3}{2}$$ respectively. If the ratio of length of angle bisectors of angle $$B$$ to length of angle bisector of angle $$C$$ is given by $$\dfrac{\alpha(\sqrt{\alpha}-1)}{\beta\sqrt{\gamma}}$$ find
$$\dfrac{\alpha + \beta + \gamma}{3}$$
Note :
$$\alpha, \beta, \gamma$$ are positive integers with $$gcd(\alpha, \beta ) = gcd(\alpha,\gamma) = gcd( \beta, \gamma = 1$$ · 5 months ago
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Firstly Using Sine Rule we get,
$$\frac { a }{ \sin { A } } =\frac { b }{ \sin { B } } =2R$$
Hence, we get $$A = \frac{\pi}{2} and \sin{B} = \frac{3}{4}$$
Let $$BC = 4k , AC = 3k , AB = \sqrt{7}k$$
Let BD and CE be the respective angle bisectors.
$$\frac { AD }{ CD } =\frac { BA }{ BC } \quad and\quad \frac { AE }{ EB } =\frac { AC }{ BC }$$
$$AD=\frac { 3\sqrt { 7 } }{ 4+\sqrt { 7 } }k \quad and\quad AE=\frac { 3 }{ \sqrt { 7 } }k$$
Then using Pythagoras Theorem , we get values of BD and CE as :
$$BD=\frac { 4\sqrt { 7 } }{ 1+\sqrt { 7 } } k\quad and\quad CE=\frac { 6\sqrt { 2 } }{\sqrt{ 7 }} k\quad$$
Their ratio will be : $$\dfrac{7(\sqrt{7} - 1 )}{9\sqrt2}$$
Hence, $$\alpha =7,\quad \beta =9,\quad \gamma =2$$
Therefore, final answer is 6 · 5 months ago
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Getting the same thing @Sarvesh Nalawade. I think you should go ahead and post the solution · 5 months ago
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Correct. · 5 months ago
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Problem 46
If $$M = \begin{pmatrix} a & b & c \\ b & c & a \\ c & a & b \end{pmatrix}$$ is an orthogonal matrix with real entries , what is the minimum value of abc ? · 5 months ago
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For an orthogonal matrix M,
$$MM^{T} = I$$ where I is the identity matrix.
Multiplying the matrices on LHS , and comparing with the identity matrix we get,
$$a^{2} + b^{2} + c^{2} = 1$$
$$ab + bc + ca = 0$$
From these two equations we get,
$$a + b + c = \pm 1$$
$$f(x) = x^{3} - (a+b+c)x^{2} + (ab+bc+ca)x - d$$ where d = abc )
Thus, a,b,c are roots of $$f(x) = 0$$
$$f(x) = x^{3} - (a+b+c)x^{2} - d$$
Let $$a + b + c = p$$
$$f(x) =x^{3} - px^{2} - d$$
Differentiating,
$$f'(x) = 3x^{2} - 2px$$
The roots of $$f'(x) = 0$$ are,
$$x = 0, \dfrac{2p}{3}$$
For the equation to have 3 real roots, the first turn of the graph should be above x-axis, and second must be below x-axis.
Consider case of $$p =1$$
The roots are $$x = 0 , \dfrac{2}{3}$$
$$\therefore f(0)f\left(\dfrac{2}{3}\right) \le 0$$
$$\left(-d\right)\left(\dfrac{-4}{27}-d\right) \le 0$$
$$\left(d\right)\left(d+\dfrac{4}{27}\right) \le 0$$
$$d \in \left[\dfrac{-4}{27},0 \right]$$
When $$p = -1$$
The roots of $$f'(x) = 0$$ are $$x = 0 , \dfrac{-2}{3}$$
$$f(0)f\left(\dfrac{-2}{3}\right) \le 0$$
$$\left(-d\right)\left(\dfrac{4}{27}-d\right)\le 0$$
$$d \in \left[0,\dfrac{4}{27}\right]$$
Range of d $$\left[\dfrac{-4}{27}, \dfrac{4}{27} \right]$$
The mininum value occurs when $$a,b,c$$ are a permutation of $$\dfrac{2}{3}, \dfrac{2}{3}, \dfrac{-1}{3}$$.
The maximum value occurs when $$a,b,c$$ are a permutation of $$\dfrac{-2}{3} , \dfrac{-2}{3} , \dfrac{1}{3}$$ · 5 months ago
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Great! Please post the next problem. @Vighnesh Shenoy · 5 months ago
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An alternate solution to @Vighnesh Shenoy 's already well written and beautiful solution:
$$a^2+b^2+c^2=1...(1) \\ab+bc+ca=0...(2)$$
Let
$$a=cos\alpha\\b=cos\beta\\c=cos\gamma$$
From $$(1)$$ we can write $$cos^2\alpha+cos^2\beta=sin^2\gamma...(3)$$
Now, using $$(1)$$ and $$(2)$$ we can write
$$cos\alpha+cos\beta+cos\gamma=\pm 1\\ cos\alpha+cos\beta=\pm 1-cos\gamma$$
Squaring both sides we get
$$cos^2\alpha+cos^2\beta+2cos\alpha .cos\beta=1+cos^2\gamma \mp 2cos\gamma$$
From $$(3)$$ we can write $$cos\alpha .cos\beta=cos^2\gamma \mp cos\gamma$$
Now multiplying $$cos\gamma$$ on both sides we get:
$$cos\alpha .cos\beta .cos\gamma=cos^3\gamma\mp cos^2\gamma$$
Critical points of the expression on the right-hand side of the above equation
(1.) $$\{0,\frac{2}{3}\}$$ when $$cos\alpha .cos\beta .cos\gamma=cos^3\gamma- cos^2\gamma$$
(2.) $$\{0,\frac{-2}{3}\}$$ when $$cos\alpha .cos\beta .cos\gamma=cos^3\gamma+cos^2\gamma$$
On checking these values, minima occurs at $$cos\gamma = \frac{2}{3}$$ and the minimum value is $$\frac{-4}{27}$$, and maximum occur maxima occurs at $$cos\gamma = \frac{-2}{3}$$ and the maximum value is $$\frac{4}{27}$$ · 5 months ago
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Problem 39:
Solve
$$\displaystyle {x}^{3}\frac{dy}{dx}={y}^{3}+{y}^{2}\sqrt{{y}^{2}-{x}^{2}}$$ · 5 months, 1 week ago
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The answer is $$xy=c(y-\sqrt{y^{2}-x^{2}})$$ The above equation is a homogeneous equation and can be written of the form $\frac{dy}{dx}={\frac{y}{x}}^{3}+{\frac{y}{x}}^{2}*\sqrt{y^{2}-x^{2}}$ Making the substitution $$y=vx$$ and we see that $$\dfrac{dy}{dx}=(v+\dfrac{dv}{dx}*x)$$. On simplification we get $\frac{dv}{v(v^{2}-1+v\sqrt{v^{2}-1})}=\frac{dx}{x}$. Taking $$\sqrt{v^{2}-1}$$ and then Multiplying and dividing by $$v-\sqrt{v^{2}-1}$$ we have $\frac{dv}{\sqrt{v^{2}-1}} -\frac{dv}{v}=\frac{dx}{x}$. On integrating both sides we have $\ln{\frac{v-\sqrt{v^{2}-1}} {v}}=\ln{x}+c$. This on substituting back $$v$$ gives us the above answer. · 5 months ago
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$$PROBLEM \quad 29$$:
Time for an easy question.
Find the range of $$\beta$$ such that $$(0,2\beta-1)$$ lies on or inside the triangles formed by the lines. $$y +3x +2 = 0$$
$$3y- 2x- 5=0$$
$$4y+x-14=0$$ · 5 months, 1 week ago
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Simply by drawing the graph I got $$\frac{4}{3} \leq \beta \leq \frac{9}{4}$$
. The triangle intersects Y-axis at points $$\left(0,\frac{5}{3}\right)$$ and $$\left(0,\frac{7}{2}\right)$$
$$\therefore \frac{5}{3} \leq 2\beta-1 \leq \frac{7}{2}$$
$$\therefore \frac{4}{3} \leq \beta \leq \frac{9}{4}$$
· 5 months, 1 week ago
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Great! Can you please add the graph for the sake of solution? Thanks! · 5 months, 1 week ago
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Correct · 5 months, 1 week ago
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Problem 26 :
Let $$^{n}a = \underbrace{a^{a^{\cdot^{\cdot^{a}}}}}_{n \text{times}}$$
$$f(x) = \displaystyle \sum_{r=1}^{x} (^{r}r)$$
Find the last digit of $$f(15)$$
Mayank Chaturvedi has solved this problem at the first place and provided the solution. But feel free to share new approaches. Thanks! · 5 months, 2 weeks ago
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The last digit is 8. Short methods are always welcome. I went to find out last digit of individual terms. Yes!. This looks lengthy but when we note down last terms, last digits of 1,2,4,5,6,10,11,14,15 are easy to find. For rest terms, dividing exponents by 4, using modular arithmetic would do. · 5 months, 2 weeks ago
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Correct. · 5 months, 2 weeks ago
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Problem 17:
$$z$$ is a complex number in the complex plane such that $$\Im(z) \ne 0$$.
If $$\dfrac{z^{2} + z + 1}{z^{2}-z+1} \in \Re$$ find the value of $$10|z|$$
Details :
$$\Im(z)$$ denotes imaginary part of $$z$$
$$\Re$$ denotes real numbers.
Prakhar Bindal has solved this problem at the first place and provided the solution. But feel free to share new approaches. Thanks! · 5 months, 2 weeks ago
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i did a bit of bashing. I used the fact that conjugate a purely real number is equal to the number itself.
Just take conjugate of Given Expression and equate to original one.
Cross multiply and cancel like terms . Finally we will obtai
a = z b = conjugate of z
(ab-1)(a-b) = 0
So either a= b which is not possible as already given in problem that a is not purely real .
Hence mod(a) = 1 · 5 months, 2 weeks ago
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Just to show what I was going at.
My method :
$$\dfrac{z^{2}+z+1}{z^{2}-z+1} \in \Re$$
$$1 +2\dfrac{z}{z^{2}-z+1} \in \Re$$
$$1 + 2\dfrac{1}{z+\dfrac{1}{z} - 1} \in \Re$$
$$\therefore z + \dfrac{1}{z} \in \Re$$
Since the conjugate of a real number is equal to itself,
$$z + \dfrac{1}{z} = \overline{z} + \dfrac{1}{\overline{z}}$$
$$z - \overline{z} = \dfrac{1}{\overline{z}} - \dfrac{1}{z}$$
$$z - \overline{z} = \dfrac{z - \overline{z}}{z\overline{z}}$$
Since, $$z$$ is not purely real, $$z \ne \overline{z}$$
$$\therefore z\overline{z} = 1$$
$$|z|^{2} = 1 \rightarrow |z| = 1$$
$$10|z| = 10$$ · 5 months, 2 weeks ago
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This one is a fairly easy one:
Problem 16:
The maximum value of the function $$f(x) = 2x^{3} - 15 x^{2} + 36x -48$$
for {$$x | x^{2} + 20 \leq 9x$$}
Vignesh Shenoy has posted the correct solution. Thanks! · 5 months, 2 weeks ago
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$$x^{2} - 9x + 20 \le 0$$
$$(x-4)(x-5) \le 0 \rightarrow x \in \text{[}4,5\text{]}$$
$$f(x) = 2x^{3} - 15x^{2} + 36x - 48$$
Differentiating,
$$f(x) = 6x^{2} - 30x + 36$$
$$f'(x) = 6(x^{2}-5x+6)$$
$$f'(x) = 6(x-2)(x-3)$$
For $$x \in \text{[}4,5\text{]}$$ , $$f'(x) > 0 \rightarrow f(x)$$ is increasing.
$$f(x)_{max} = f(5) = 7$$ · 5 months, 2 weeks ago
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Problem 14 :
If the sum of the first n terms of an AP is $$cn^2$$, then find the sum of the cubes of these n terms.
Saakshi Singh has posted the solution first. Thanks! · 5 months, 2 weeks ago
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Using sum formula of AP, we get $2cn= 2a + (n-1)d$
$\Rightarrow 2cn - a = a + (n-1)d \\ \Rightarrow (2cn - a)^3 = ( a + (n-1)d)^3 .$
We have to find $$\displaystyle \sum_{n=1}^{ n} \left( a + (n-1)d \right)^3 =\displaystyle \sum_{n=1}^{ n}(2cn-a)^3$$. Nos putting $$n=1$$, we get $$a=c$$.
So we have sum of the cubes of $$n$$ terms
$= c^3 \cdot \displaystyle \sum_{ n=1}^{ n} (2n-1)^3$
$= c^3 \left( n^2(2n^2 - 1) \right) .$ · 5 months, 2 weeks ago
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I've cleaned up your solution for now. But it's very easy to type an equation using latex which you can learn from this note. @Saakshi Singh · 5 months, 2 weeks ago
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Problem 13:
$f^{ 2 }\left( n+1 \right) f\left( n \right) +2f\left( n+1 \right) =f\left( n \right)$
Given $f\left( 0 \right) =1$
Find $\lim_{n\to\infty} { 2 }^{ n }f\left( n \right)$
Ashu Dablo has solved this problem at the first place and has posted the solution. Thanks! · 5 months, 3 weeks ago
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@Akul Agrawal Simplify the given equation to the form:
$$f\left(n \right)$$ = $$\frac {2(f\left (n+1 \right))} { 1 - f^{2}\left (n+1 \right)}$$
Now we say that for $$f\left(n \right) = \tan \theta$$, $$f\left(n+1 \right)=\tan \frac{\theta} {2}$$
As f(1) =1, from above relation, we can say that $$f\left(n \right)=\tan \frac{\pi}{2^{(n+1)}}$$ which for n $$-> \infty , -> 0$$
multiply divide by $$tan \frac{\pi}{2^{(n+1)}}$$
now for $$x->0$$ $$\frac {\tan x}{x} =1$$
So answer is $$\frac{\pi}{4}$$
Sorry for my latex! · 5 months, 3 weeks ago
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The equation becomes inconsistent for n=0 . Please check . · 5 months, 2 weeks ago
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Problem 12:
Evaluate:
$\large \displaystyle \lim_{ x\rightarrow 0 }{ \left\{ \frac { sinx }{ x } \right\} }^{ \frac { 1 }{ \left\{ \frac { tanx }{ x } \right\} } }$
where,$$\{ . \}$$ is fractional part function.
Rishabh Cool has provided a complete solution to this problem. Thanks! · 5 months, 3 weeks ago
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Just to expand.... $$\{\dfrac{\sin x}{x}\}=\dfrac{\sin x}{x}$$ and $$\{\dfrac{\tan x}{x}\}=\dfrac{\tan x}{x}-1$$ as $$\sin x<x<\tan x$$.
The form is $$1^{\infty}$$. Therefore write it as:
$e^{\displaystyle\lim_{x\to 0}(\frac{\sin x}{x}-1)\times \frac{1}{\frac{\tan x}{x}-1}}$
$= e^{\displaystyle \lim_{x\to 0}\dfrac{\sin x-x}{\tan x-x}}$
Apply Lhospital to get $$e^{-1/2}$$. · 5 months, 3 weeks ago
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Problem 11:
If the medians of a $$\Delta ABC$$ make angles $$\alpha ,\beta ,\gamma$$ with each other, then find the value of:$\cot { \left( \alpha \right) } +\cot { \left( \beta \right) } +\cot { \left( \gamma \right) } +\cot { \left( A \right) } +\cot { \left( B \right) } +\cot { \left( C \right) }$
Consider $$\alpha ,\beta ,\gamma$$ to be acute.
Saarthak Marathe is the first person to solve this problem and provide the solution. Thanks! · 5 months, 3 weeks ago
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The answer is $$0$$.
· 5 months, 3 weeks ago
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Problem 7:
If $${ \left( 1+x \right) }^{ n }={ C }_{ 0 }+{ C }_{ 1 }x+{ C }_{ 2 }{ x }^{ 2 }+...+{ C }_{ n }{ x }^{ n }$$.
Then find a closed of: ${ C }_{ 0 }^{ 2 }+2{ C }_{ 1 }^{ 2 }+3{ C }_{ 2 }^{ 2 }+...+\left( n+1 \right) { C }_{ n }^{ 2 }$
Rohit Ner has solved this problem at the first place and posted the solution. Thanks! · 5 months, 3 weeks ago
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$$x{(1+x)}^{n}=C_0 x+C_1 {x}^2 +C_2 {x}^3+\cdots +C_n {x}^{n+1}$$
Differentiating both sides, $${(1+x)}^{n-1}(nx+1+x)=C_0 +2C_1 x +3C_2 {x}^2 +\cdots + (n+1)C_n {x}^{n}$$
Also $${\left(1+\dfrac{1}{x}\right)}^{n}=C_0 + \dfrac{C_1}{x} + \dfrac{C_2}{{x}^2} +\cdots +\dfrac{C_n}{{x}^{n}}$$
The given series is sum of all constant terms obtained in the expansion of
$${(1+x)}^{n-1}((n+1)x+1).{\left(1+\dfrac{1}{x}\right)}^{n}$$
which is same as coefficient of $${x}^{n}$$ in $${(1+x)}^{2n-1}$$ i.e. $$\binom{2n-1}{n}$$
plus coefficient of $${x}^{n-1}$$ in $$(n+1){(1+x)}^{2n-1}$$ i.e. $$(n+1)\binom{2n-1}{n-1}$$
So the closed form is $$\binom{2n-1}{n}+(n+1)\binom{2n-1}{n-1}$$ · 5 months, 3 weeks ago
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Problem 6:
Evaluate the sum of the non - real roots of the equation
$x^4+x^3-5x^2-12x-6=0.$
Aditya Kumar solved the problem at the first place and provided the solution. Thanks! · 5 months, 3 weeks ago
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Just for enlightening, I'm posting my solution (again).
Let $$\displaystyle x = t-1$$ the equation converts to
$$\displaystyle t^4-3t^3-2t^2-3t+1 = 0$$
$$\displaystyle \implies t^2 - 3t -2 -\dfrac{3}{t} + \dfrac{1}{t^2} = 0$$
Now, let $$\displaystyle y = t + \dfrac{1}{t}$$, we have,
$$\displaystyle y^2 -3y - 4 = 0$$
$$\displaystyle \implies (y-4)(y+1) = 0$$
$$\displaystyle \implies (t^2-4t+1)(t^2-t+1) = 0 \quad \left( \because y = t + \dfrac{1}{t} \right)$$
$$\displaystyle \implies (x^2 - 2x -2)( x^2 + 3x + 3) = 0 \quad \left( \because t = x+1 \right)$$
Only the second factor gives non - real roots since it's discriminant is negative, therefore sum is $$\boxed{-3}$$ · 5 months, 2 weeks ago
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The equation can be written as $\left( { x }^{ 2 }-2x-2 \right) \left( { x }^{ 2 }+3x+3 \right) =0$
The non- real solutions are: $$x=\frac { -1 }{ 2 } \left( \sqrt { 3 } i+3 \right)$$ and $$x=\frac { 1 }{ 2 } \left( \sqrt { 3 } i-3 \right) \quad$$
Hence the sum is: $$-3$$ · 5 months, 3 weeks ago
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The equation factors out as,
$$({x}^{2}-2x-2)({x}^{2}+3x+3)=0$$
Now solve $${x}^{2}-2x-2=0$$ and $${x}^{2}+3x+3=0$$.
We see that the discriminant of $${x}^{2}+3x+3=0$$ is negative.
Therefore the sum of the non-real roots are -3 · 5 months, 3 weeks ago
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Problem 5:
$\displaystyle \sum _{ r=1 }^{ 7 }{ { \tan }^{ 2 }\left( \frac { r\pi }{ 16 } \right) } =?$
Samuel Jones is the first person to solve this problem and provide the solution. Thanks! · 5 months, 3 weeks ago
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The sum can be written as $$\displaystyle -8 +\sum_{r=1}^{7} \sec^2 \left(\dfrac{r \pi}{16}\right)$$
$$\displaystyle =-8 + \sum_{r=1}^{7} \dfrac{1}{ \cos^2 \left(\dfrac{r \pi}{16}\right)}$$
Consider the $$\displaystyle 15^{\text{th}}$$ Chebyshev Polynomials of the Second kind
$$\displaystyle U_{15} (x) = 2^{15}\prod_{k=1}^{15} \left(x-\cos \left(\dfrac{r \pi}{n} \right)\right)$$
Taking logarithm and differentiating two times at $$x=0$$, we have
$$\displaystyle S = -8 + 43 =\boxed{35}$$
This way, we can generalize to $$n$$ terms also. · 5 months, 3 weeks ago
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Last problem for this page:Problem No. '50'
A cevian $$AQ$$ of a equilateral $$\Delta$$ $$ABC$$ is extended to meet circumcircle at $$P$$. If $$PB=50$$ and $$PC=45$$, find $$PQ$$ upto 3 decimal places.
Deeparaj Bhat has provided the answer · 5 months ago
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Great! This is the last problem of this contest on this note. The solution poster will post the next problem on the continued part of the contest: JEE-Advanced Maths Contest (Continued).
Thanks! · 5 months ago
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Solution by Deeparaj Bhat:
Extend $$CP$$ to $$D$$ such that $$\Delta BDP$$ is equilateral. Then, \begin{align*}\angle BCD&=\angle QCP \\\angle QPC&=\angle ABC\quad \left(\because \text{ angles in the same segment are equal }\right)\\&=60^{\circ}\\&=\angle BDP\\\implies \Delta DCB &\sim \Delta PCQ\\\implies \frac{ DB }{PQ}&=\frac{ DC}{PC }\\&=1+\frac{PB}{PC}\quad \left( \because DC=DP+PC=BP+PC \right)\\\implies \frac{1}{PC}+\frac{1}{PB}&=\frac{1}{PQ}\quad \left( \because BP=DB \right)\end{align*}
Substituting the given values the answer comes out to be 23.684. · 5 months ago
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23.684. I'll post the soln in some time... · 5 months ago
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Waiting for the solution. · 5 months ago
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Please provide the complete solution. · 5 months ago
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Problem 48 : If $$\displaystyle \int _{ 0 }^{ \frac { \pi }{ 2 } }{ \frac { dx }{ \left( a\cos ^{ 2 }{ x } +b\sin ^{ 2 }{ x } \right) ^{ 2 } } } =\quad \frac { \pi \left( a+b \right) }{ p{ \left( ab \right) }^{ q } }$$ ;
where p and q are positive rational numbers and ab>0 , then find the value of pq
Vighnesh Shenoy has provided a complete solution to this problem. · 5 months ago
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$$I = \displaystyle \int_{0}^{\dfrac{\pi}{2}}\dfrac{dx}{(a\cos^{2}(x) + b\sin^{2}(x))}$$
Put, $$\tan(x) = t$$
$$I = \displaystyle \int_{0}^{\infty} \dfrac{dt}{a+bt^{2}} = \dfrac{\pi}{2\sqrt{ab}}$$
$$\therefore \displaystyle \int_{0}^{\dfrac{\pi}{2}}\dfrac{dx}{(a\cos^{2}(x) + b\sin^{2}(x))} =\dfrac{\pi}{2}(ab)^{\frac{-1}{2}}$$
For a continuous and differentiable function,
$$\displaystyle \dfrac{d}{dy} \int_{a}^{b} f(x,y)dx = \int_{a}^{b} \dfrac{\partial}{\partial y} f(x,y) dx$$
Differentiating with respect to a,
$$\displaystyle \int_{0}^{\dfrac{\pi}{2}}\dfrac{\partial}{\partial a} \dfrac{dx}{(a\cos^{2}(x) + b\sin^{2}(x))} = \dfrac{\partial}{\partial a} \left( \dfrac{\pi}{2}(ab)^{\frac{-1}{2}}\right)$$
$$\therefore \displaystyle \int_{0}^{\dfrac{\pi}{2}}\dfrac{-\cos^{2}dx}{(a\cos^{2}(x) + b\sin^{2}(x))^{2}} = \dfrac{-\pi}{4}b^{\frac{-1}{2}}a^{\frac{-3}{2}}$$
Differentiate with respect to b,
$$\displaystyle \int_{0}^{\dfrac{\pi}{2}}\dfrac{\partial}{\partial b} \dfrac{dx}{(a\cos^{2}(x) + b\sin^{2}(x))} = \dfrac{\partial}{\partial b} \left( \dfrac{\pi}{2}(ab)^{\frac{-1}{2}}\right)$$
$$\therefore \displaystyle \int_{0}^{\dfrac{\pi}{2}}\dfrac{-\sin^{2}dx}{(a\cos^{2}(x) + b\sin^{2}(x))^{2}} = \dfrac{-\pi}{4}b^{\frac{-3}{2}}a^{\frac{-1}{2}}$$
Adding both the integrals,
$$\displaystyle \int_{0}^{\dfrac{\pi}{2}}\dfrac{dx}{(a\cos^{2}(x) + b\sin^{2}(x))^{2}} = \dfrac{\pi}{4\sqrt{ab}}\left(\dfrac{1}{a} + \dfrac{1}{b} \right)$$
$$\therefore \displaystyle \int_{0}^{\dfrac{\pi}{2}}\dfrac{dx}{(a\cos^{2}(x) + b\sin^{2}(x))^{2}} = \dfrac{\pi(a+b)}{4(ab)^{\frac{3}{2}}}$$
$$p = 4 , q = \dfrac{3}{2}$$
$$pq = 6$$ · 5 months ago
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Problem 44:
Find the locus of point of intersection of tangents to an ellipse $$\frac{x^2}{a^2}+\frac{y^2}{b^2}=1$$ at two points,whose eccentric angles differ by a constant angle $$\alpha$$ .
Kunal Verma has provided a complete solution to this problem.Thanks! · 5 months ago
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Point of intersection of tangents at points who's eccentric angles are $$i$$ and $$j$$ :-
x= $$a \times \frac{\cos \frac{i+j}{2}}{\cos \frac{i-j}{2}}$$ and y= $$b \times \frac{\sin \frac{i+j}{2}}{\cos \frac{i-j}{2}}$$
Thus $$\frac{x^2}{a^2} \ + \frac{y^2}{b^2} \ = \sec^2 \frac{i-j}{2}$$
$$\frac{x^2}{a^2} \ + \frac{y^2}{b^2} \ = \sec^2 \frac{\alpha }{2}$$ · 5 months ago
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Correct! But prove your 1st statement in your solution and post the next question · 5 months ago
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The thread should clear out older comments. It took ages to put up that solution. Won't live to see the proof of that uploaded. I'll just mention here that it was obtained by solving the parametric equations of tangents. · 5 months ago
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Problem 43 :
Find the remainder when $$32^{32^{32}}$$ is divided by 7.
Mayank Chaturvedi has solved this problem with the correct solution. · 5 months ago
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$$32\equiv -3 (mod 7)\\ {3}^{3}\equiv -1 (mod 7)\\ {32}^{3*10+2}\equiv {(-3)}^{3*10+2} \equiv (1)*9 \equiv 9 (mod 7)\\ {32}^{32^{32}}\equiv {(9)}^{3*10+2} \equiv (1)*81 \equiv 4 (mod 7)\\$$
Hence the answer is $$\boxed 4$$ · 5 months ago
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The answer is right, however you used
$$32^{32^{32}} \equiv (32^{32})^{32} \equiv 9^{32} \equiv 4 \pmod{7}$$ · 5 months ago
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Yes i agree with you. Have a check @Saarthak Marathe the answer is a coincidence this time.
Let me try once.
Reference-euler's theorem
$$\varphi (7)=6\quad and\quad gcd(32,7)=1\\ { 32 }^{ 6 }\equiv 1mod(7)............me-1\\ Now\quad we\quad find\quad { 32 }^{ 32 }mod\quad 6\\ { 32 }^{ 32 }\equiv { 2 }^{ 32 }\equiv 4^{ 4 }\equiv 4mod(6)......me-2\\ Using\quad me-1\quad and\quad me-2\\ { 32 }^{ { 32 }^{ 32 } }\equiv { 32 }^{ 6x+4 }\equiv { 32 }^{ 4 }mod(7)\\ { 32 }^{ 4 }\equiv 4^{ 4 }\equiv 256=4mod(7)\\ So\quad 4\quad is\quad the\quad remainder\quad :)$$ · 5 months ago
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Perfect. · 5 months ago
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That is an incorrect way of evaluation of power towers.
$$a^{b^{c}} \ne (a^{b})^{c}$$ · 5 months ago
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Problem 42:
Evaluate
$$\displaystyle \lim_{n \rightarrow \infty} \left[\frac{{n}^{1/2}}{{n}^{3/2}}+\frac{{n}^{1/2}}{{(n+3)}^{3/2}}+\frac{{n}^{1/2}}{{(n+6)}^{3/2}}+........+\frac{{n}^{1/2}}{{(n+3(n-1))}^{3/2}}\right]$$
Vighnesh Shenoy has provided solution to this question. Thanks! · 5 months ago
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This problem can be easily solved by using the concept of definite integral as the sum of limits, which is applied as
$$\displaystyle \lim_{n \to \infty} \sum_{k=0}^{n-1} \dfrac{n^{\frac{1}{2}}}{(n+3k)^{\frac{3}{2}}} = \displaystyle \int_{0}^{1} \dfrac{1}{(1+3x)^{\frac{3}{2}}}dx = \left[ \dfrac{2}{3(\sqrt{1+3x})}\right]_{1}^{0} = \dfrac{2}{3} - \dfrac{2}{6} = \dfrac{2}{6} = \dfrac{1}{3}$$ · 5 months ago
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Great! It would be awesome if you can make your solution more detailed. You can post the next problem. Thanks! · 5 months ago
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Problem no. 40.
An easy question:Find the following $\dbinom{n}{0}+3\dbinom{n}{1}+5\dbinom{n}{2}+........+(2n+1)\dbinom{n}{n}$ Miraj Shah has posted the solution to the problem. Thanks! · 5 months ago
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The above question can be written in the following manner:
$$\displaystyle \sum_{r=0}^{n} (2r+1)\dbinom{n}{r}$$ $$=2\displaystyle\sum_{r=0}^{n}r\dbinom{n}{r} +\displaystyle\sum_{r=0}^{n}\dbinom{n}{r} = n2^n +2^n= \boxed{(n+1)2^n}$$ · 5 months ago
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Please post the next question · 5 months ago
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Problem 38:
Find the number of ways to go from $$(0,0)$$ to $$(8,7)$$ in a rectangle formed by vertices $$(0,0) , (8,0) , (0,7), (8,7)$$. The person can only move from $$(i,j)$$ to $$(i+1,j)$$ OR $$(i,j+1)$$ OR $$(i+1,j+1)$$ in one step. · 5 months, 1 week ago
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Let the person travel $$d$$ diagonals in one trip. So the remaining $$15-2d$$ sides,he travels up or right, which can be done in $$\dbinom{15-2d}{8-d}$$ ways. The $$d$$ diagonals can be placed in $$\dbinom{15-d}{d}$$ ways.
So the total number of ways=$$\displaystyle \sum_{d=0}^{7} \dbinom{15-2d}{8-d}\dbinom{15-d}{d}$$.
This summation turns out as $$\boxed {108545}$$ · 5 months, 1 week ago
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@Saarthak Marathe
No one has solved the problem in the time limit. Can you please post the solution and the next problem?
Thanks! · 5 months, 1 week ago
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PROBLEM 37
In how many ways 12 different books can be distributed among 5 children so that 2 get three books each, and 3 get two books each.
Saarthak Marathe and Miraj Shah had solved this question · 5 months, 1 week ago
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The number of ways distributing $$n$$ distinct things into $$r$$ groups and arranging them among $$r$$ people such that $$s_1, s_2,s_3,...s_r$$ denotes the number of things in the respective groups is :
$$\large \frac{(n!)( r!)}{(s_1!)( s_2!) ...(s_r!)}$$
Note in the above formula $$s_1\neq s_2\neq s_3\neq ... s_r$$
For the given question $$n=12$$; $$r=5$$; $$s_1=s_2=3$$ and $$s_3=s_4=s_5=2$$.
Now, the above formula can be used but, with a slight modification. Since groups are only identified by the number of objects it has, therefore there is no difference between $$s_1$$ and $$s_2$$ and there is no difference between $$s_3, s_4$$ and $$s_5$$. Hence the number of cases will reduce by a factor of $$2!$$ with respect to $$s_1$$ and $$s_2$$ and by $$3!$$ with respect to $$s_3, s_4$$ and $$s_5$$. Hence, in totality the required answer is:
$$\large \frac{12!\times 5!}{(3!)^2(2!)^3(2!)(3!)} = 16632000$$
Is the above answer correct? @Mayank Chaturvedi · 5 months, 1 week ago
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$$\dbinom{12}{6}\dbinom{6}{3}\dbinom{6}{2}\dbinom{4}{2}\dbinom{5}{3}=16632000$$
First choose 2 people of 5 which get 3 books each. Select 6 books(3*2=6) out of 12 books for these two 2 people. Then distribution of these 6 books by letting the first person choose 3 books out of 6 and the rest goes to 2nd person. Now for the remaining 3 people,there are 6 books. 1st person selects 2 books out of 6 books and 2nd person chooses 2 out of 4 books and the remaining goes to the 3rd person. I hope it is clear now. @Mayank Chaturvedi · 5 months, 1 week ago
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As you asked, your solution is Crystal clear But it would be interesting if we can find out an explanation for solution by @Miraj Shah.Which I feel is as good approach as yours. · 5 months, 1 week ago
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Can you please tell what is the numerical figure you are getting after solving your expression? · 5 months, 1 week ago
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16632000 · 5 months, 1 week ago
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OK! Thanks! Waiting for the next question from you... · 5 months, 1 week ago
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Problem 35:
It can be proved that the areas $$S_0,S_1,S_2,S_3,...$$ bounded by the $$x-axis$$ and the half waves of the curve $$y=e^{-\alpha x}sin\beta x$$, $$x\ge 0$$ form a geometric progression. Find the common ratio of this geometric progression. · 5 months, 1 week ago
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Answer: $${e}^{-\frac{\alpha\pi}{\beta}}$$
First I wrote the general integral for $${S}_{j}$$ and then divided by $${S}_{j-1}$$
Is it correct? @Miraj Shah · 5 months, 1 week ago
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The answer is correct! Can you post a clearer picture of your working if possible?
Thanks! · 5 months, 1 week ago
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The problem is my mobile phone does not have a good camera. I'll tell u what I did. First I wrote the general integral for $${S}_{j}$$ and then divided by $${S}_{j-1}$$ · 5 months, 1 week ago
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The method is correct! Just add this statement to your solution so that others can get an idea as to what was your approach! Good solution anyways! · 5 months, 1 week ago
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Problem 34:
Solve:
$$\displaystyle ({x}^{2}+y)\frac{dy}{dx}=6x$$ · 5 months, 1 week ago
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We can write the question as follows:
$$(x^2+y)dy=3\times 2xdx$$
Now let $$x^2=\lambda$$
$$(\lambda+y)=3\large \frac{d\lambda}{dy}$$
We'll do another substitution here, let $$\lambda+y=t$$
Therefore,
$$t+3=3\large \frac{dt}{dy}$$
Now after rearranging the terms and integrating we get:
$$3ln|x^2+y+3| = y+c$$
Is this correct? @Saarthak Marathe · 5 months, 1 week ago
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It is incorrect. You missed a number in your final answer · 5 months, 1 week ago
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Got it! it should be $$x^2+y+3$$ right? · 5 months, 1 week ago
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Yes correct!! Post the next question · 5 months, 1 week ago
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Problem 33:
Two persons $$A$$ and $$B$$ agree to meet at a place between $$11$$ to $$12$$ noon. The first one to arrive waits for $$20$$ minutes and then leaves. If the time of their arrival be independent and random, what is the probability that $$A$$ and $$B$$ shall meet? · 5 months, 1 week ago
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Just an alternate solution:
Let the time of arrival of $$A$$ be denoted along the $$x-axis$$ and that of $$B$$ along the $$y-axis$$.
Therefore, the required event is denoted graphically be the area enclosed in $$|x-y|\le 20$$. Now the ratio of the area of the event to the area of sample space($$=3600$$) gives the answer $$\frac{5}{9}$$ · 5 months, 1 week ago
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Probability of meeting If the first person comes between 0-40 minutes=$$2/3*1/3$$=$$2/9$$
Probability of meeting if first person comes between 40-60 minutes=$$1/3$$
Therefore,total probability=$$5/9$$
Is this correct? @Miraj Shah · 5 months, 1 week ago
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Ya! The answer is correct. · 5 months, 1 week ago
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Problem 32:
The area bounded by the curve $$y=x-{x}^2$$ and the line $$y=mx$$ equals $$\large\frac{9}{2}$$.
Find the sum of all possible values of $$m$$. · 5 months, 1 week ago
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Let the points of intersection between $$y=x-x^2$$ and $$y'=mx$$ be $$x_1$$ and $$x_2$$. Therefore $$x_1, x_2$$ are the roots of the equation $$x^2 +(m-1)x=0$$...$$(1)$$
Given:
$$\displaystyle \int_{x_1}^{x_2} y-y'\, dx =\frac{9}{2}$$
$$\displaystyle \int_{x_1}^{x_2} x(1-m)-x^3\, dx=\frac{9}{2}$$
$$\large \frac{(1-m)(x_2-x_1)(x_2+x_1)}{2}-\frac{(x_2-x_1)(x_2^2+x_1x_2+x_1^2)}{3}=\frac{9}{2}$$
Now using equation $$(1)$$ we can write $$x_2+x_1=1-m$$; $$x_1x_2=0$$ and $$x_2-x_1=|1-m|$$
Therefore finally,
$$m=-2$$ or $$m=4$$
Therefore, the required answer is $$\boxed{2}$$
Is this the answer? · 5 months, 1 week ago
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Correct. :). Waiting for the next problem. · 5 months, 1 week ago
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Problem 31 :
Given that,
$$x^{2} + y^{2} + z^{2} = R^{2}$$
Let,
$$P = axy + byz$$
If $$P_{max} = R^{2}f(a,b)$$
Find $$f(3,4)$$ · 5 months, 1 week ago
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Let $$x=R\sin\alpha\sin\beta,y=R\cos\beta,z=R\cos\alpha\sin\beta$$
\begin{align} P&=y\left(ax+bz\right)\\&=\dfrac{{R}^2}{2}\sin 2\beta \left(a\sin\alpha+b\cos\alpha\right)\\{P}_{max}&=\dfrac{{R}^2}{2}\sqrt{{a}^2+{b}^2}\\\Rightarrow f(a,b)&=\dfrac{\sqrt{{a}^2+{b}^2}}{2}\\f(3,4)&=\frac{5}{2}\end{align} · 5 months, 1 week ago
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Correct. · 5 months, 1 week ago
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I got the answer 5/2. Applying cauchy-schwarz inequality
$$\sqrt { ({ a }^{ 2 }+b^{ 2 })(x^{ 2 }{ y }^{ 2 }+y^{ 2 }z^{ 2 }) } \ge (axy+byz)\\ \sqrt { ({ a }^{ 2 }+b^{ 2 }){ y }^{ 2 }(x^{ 2 }+z^{ 2 }) } \ge (axy+byz)\\ \sqrt { ({ a }^{ 2 }+b^{ 2 }){ y }^{ 2 }(R^{ 2 }-y^{ 2 }) } \ge (axy+byz)\\ \frac { { R }^{ 2 } }{ 2 } \sqrt { ({ a }^{ 2 }+b^{ 2 }) } \ge (axy+byz)$$ · 5 months, 1 week ago
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You guys decide who is going to post next. · 5 months, 1 week ago
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Problem 30 :
Let P(x) be a polynomial of degree 11 such that : $$P(x) = \dfrac{1}{x+1} , 0 \le x \le 11$$
Find the value of $$P(12)$$ . · 5 months, 1 week ago
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$$P(x)(x+1) = 1$$
$$P(x)(x+1) - 1 = g(x)$$
$$g(x)$$ has roots $$0,1,2,3,4\ldots 11$$
$$\therefore g(x) = ax(x-1)(x-2)\ldots(x-11)$$
$$P(x)(x+1)-1 = ax(x-1)(x-2)\ldots(x-11)$$
Substituting $$x = - 1$$,
$$-1 = a(-1)(-2)\ldots(-12)$$
$$-1 = 12!a$$
$$a = -\dfrac{1}{12!}$$
$$P(12)(13) - 1 = -\dfrac{1}{12!}\times 12!$$
$$P(12)(13) - 1 = -1$$
$$P(12) = 0$$ · 5 months, 1 week ago
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That's correct !! · 5 months, 1 week ago
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Problem 28: (On behalf of Vighnesh Shenoy)
If $$\vec a$$ and $$\vec b$$ are two vectors such that $$|\vec{a}|=1, |\vec b|=4$$ and $$\vec a \cdot \vec b =2$$, then find the angle between $$\vec b$$ and $$\vec c$$ given that $$\vec c=\left( 2 \vec a \times \vec b \right) - 3 \vec b$$.
Mayank Chaturvedi has solved this problem at the first place and provided the solution. But feel free to share new approaches. Thanks! · 5 months, 1 week ago
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Sir please extend this page by making a new note as it is becoming slower to load the contents and rendering the latex. · 5 months, 1 week ago
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Yes sir @Sandeep Bhardwaj. The note is lagging too much and taking too much time to load. · 5 months, 1 week ago
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Earlier i wrote an answer telling angle between $$\vec c$$ and -$$\vec b$$ so you too take care of it.
Check this:
i have got answer 150 degrees
$$\vec { a } .\vec { b } =|a||b|cos\theta \\ \theta =\frac { \pi }{ 3 } \\ \vec { v } =2\vec { a } X \vec { b } .So\vec { |v| } =4\sqrt { 3 } \quad perpendicular\quad to\quad \vec { b } \\ \vec { c } =\vec { v } -3\vec { b } ,which\quad is\quad at\quad { 30 }^{ \circ }to\quad -\vec { b } \quad So\quad { 150 }^{ \circ } \quad angle \quad between \quad \vec c \quad\ and \quad \vec b$$
Note:$$\vec c$$ is resultant of $$-3\vec b$$ and $$\vec v$$, which are perpendicular. We have |3b|=12 and |v|=4$$\sqrt 3$$.So tan$$\theta$$=4$$\sqrt 3$$/12. $$\theta$$=30. Angle between $$\vec c \quad and \quad \vec 3b \quad is\quad same \quad as\quad angle$$ between $$\vec c \quad and \quad \vec b$$
All credits to @Vighnesh Shenoy, · 5 months, 1 week ago
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Great! Can you please post the next problem? @Mayank Chaturvedi · 5 months, 1 week ago
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PROBLEM 27:
$$\csc ^{ -1 }{ \sqrt { 5 } } +\csc ^{ -1 }{ \sqrt { 65 } } +\csc ^{ -1 }{ \sqrt { 325 } } +\ldots =\frac { n\pi }{ 32 }$$
If you were given a chance to visit n (its value to be found from above expression) towns, in any way you want irrespective of order. I tell you that you can do so in $${ A }^{ B }$$ ways.A & B are naturals.Find minimum value of A+B.
$$A\quad 10\\ B\quad 8\\ C\quad 6\\ D\quad 4$$.
Vighnesh Shenoy has solved this problem at the first place and provided the solution. But feel free to share new approaches. Thanks! · 5 months, 2 weeks ago
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$$S = \csc^{-1}(\sqrt{5}) + \csc^{-1}(\sqrt{65}) + \csc^{-1}(\sqrt{325}) \ldots$$
$$S = \sin^{-1}\left(\dfrac{1}{\sqrt{5}}\right) + \sin^{-1}\left(\dfrac{1}{\sqrt{65}}\right) + \sin^{-1}\left(\dfrac{1}{\sqrt{325}}\right) + \ldots$$
$$S = \tan^{-1}\dfrac{1}{2} + \tan^{-1}\dfrac{1}{8} + \tan^{-1}\dfrac{1}{18} + \ldots$$
$$S = \displaystyle \sum_{k=1}^{\infty} \tan^{-1}\dfrac{1}{2k^{2}} = \sum_{k=1}^{\infty} \tan^{-1}(2k+1) - \tan^{-1}(2k-1) = \dfrac{\pi}{2} - \dfrac{\pi}{4} = \dfrac{\pi}{4}$$
$$\therefore n = 8$$
I can visit 0 towns, 1 town, 2 towns, and so forth till 8 towns irrespective of order.
Number of ways I can do this = $$\displaystyle \sum_{r=0}^{8}\dbinom{8}{r} = 2^{8}$$
$$2^{8} = 4^{4} = 16^{2}$$
Minimum value of A + B = 8.
Next time you give a summation, please give more terms. I am still not sure that the series I used is correct. · 5 months, 2 weeks ago
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Correct . And yes i will take care of more terms in the series next time. · 5 months, 2 weeks ago
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I think you mean $$\tan ^{ -1 }{ \frac { 1 }{ 2 } }$$ in the third line, and not $$\tan ^{ -1 }{ \frac { 1 }{ 4 } }$$ · 5 months, 2 weeks ago
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Time for an easy question.
Problem. 24 :
Let $$A_{1}, A_{2}, A_{3}, A_{4}$$ be the areas of four faces of a tetrahedron, and $$h_{1}, h_{2}, h_{3}, h_{4}$$ be the corresponding altitudes. Give that the volume of tetrahedron is 5 cubic units . Find the minimum value of the expression
$$\dfrac{(A_{1} + A_{2} + A_{3} + A_{4})(h_{1}+h_{2}+h_{3}+h_{4})}{5!}$$
Sarvesh Nalawade has solved this problem at the first place and provided the solution. But feel free to share new approaches. Thanks! · 5 months, 2 weeks ago
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Volume of tetrahedron = $$\dfrac{A \cdot h}{3}$$
$$\therefore 15 = A_{1} \cdot h_{1} = A_{2} \cdot h_{2} = A_{3} \cdot h_{3} = A_{4} \cdot h_{4}$$
We have to minimize :
$$S = \dfrac{15(A_{1}+A_{2}+A_{3}+A_{4})\left(\dfrac{1}{A_{1}} + \dfrac{1}{A_{2}} + \dfrac{1}{A_{3}} + \dfrac{1}{A_{4}}\right)}{5!}$$
Using AM GM ineqaulity :
$$\displaystyle \sum_{i=1}^{4}A_{i} \geq 4\left({A_{1} \cdot A_{2} \cdot A_{3} \cdot A_{4}}\right)^{\frac{1}{4}}$$
$$\displaystyle \sum_{i=1}^{4} \dfrac{1}{A_{i}} \geq 4\left(\dfrac{1}{A_{1} \cdot A_{2}\cdot A_{3}\cdot A_{4}}\right)^{\frac{1}{4}}$$
Multiplying these two we get :
$$\displaystyle \sum_{i=1}^{4}A_{i} \times \displaystyle \sum_{i=1}^{4} \dfrac{1}{A_{i}} \geq 16$$
Hence,
$$S_{min} = \dfrac{15 \times 16}{5!} = 2$$ · 5 months, 2 weeks ago
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Correct!
I used the Cauchy-Schwartz inequality instead of the AM-GM.
$$\left(\sqrt{A_{1}}^{2}+\sqrt{A_{2}}^{2}+\sqrt{A_{3}}^{2}+\sqrt{A_{4}}^{2}\right)\left(\dfrac{1}{\sqrt{A_{1}}^{2}} + \dfrac{1}{\sqrt{A_{2}}^{2}} + \dfrac{1}{\sqrt{A_{3}}^{2}} + \dfrac{1}{\sqrt{A_{4}}^{2}}\right) \geq \left(\sqrt{A_{1}}\dfrac{1}{\sqrt{A_{1}}} + \sqrt{A_{2}}\dfrac{1}{\sqrt{A_{2}}} + \sqrt{A_{3}}\dfrac{1}{\sqrt{A_{3}}} + \sqrt{A_{4}}\dfrac{1}{\sqrt{A_{4}}}\right)^{2}$$
Equality holds when :
$$A_{1} = A_{2} =A_{3} = A_{4}$$ · 5 months, 2 weeks ago
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Problem 23:
Find the closed form of $\int _{ 0 }^{ \infty }{ \left\lfloor \frac { n }{ { e }^{ x } } \right\rfloor dx }$
Statutory warning: Do not relate this to Gamma Function.
Vighnesh Shenoy has solved this problem at the first place and provided the solution. But feel free to share new approaches. Thanks! · 5 months, 2 weeks ago
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$$I = \displaystyle \int_{0}^{\infty} \left \lfloor \dfrac{n}{e^{x}} \right \rfloor dx$$
$$e^{-x} = t \rightarrow dx = \dfrac{-dt}{t}$$
$$I = \displaystyle \int_{0}^{1} \left \lfloor nt \right \rfloor \dfrac{dt}{t}$$
$$I = \displaystyle \sum_{k=1}^{n-1} \int_{\frac{k}{n}}^{\frac{k+1}{n}} \dfrac{k}{t} dt$$
$$I = \displaystyle \sum_{k=1}^{n-1} k\log\left(\dfrac{k+1}{k}\right)$$
$$S = \displaystyle \sum_{k=1}^{n-1} \left[(k+1)\log(k+1)-k\log(k) - \log(k+1)\right]$$
$$S = n\log(n) - log(n!)$$ · 5 months, 2 weeks ago
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PROBLEM 22
Let $$a(n)=1+\dfrac{1}{2}+\dfrac{1}{3}+\cdots+\dfrac{1} {2^n-1}$$.. Then:
A: $$a(100) \leq 100$$
B: $$a(100)>100$$
C: $$a(200)\leq 100$$
D: $$a(200)> 100$$
For sake of clarification $$\displaystyle a\left( n \right) =\sum _{ r=1 }^{ { 2 }^{ n }-1 }{ \frac { 1 }{ r } }$$
Aditya Kumar has solved this problem at the first place and provided the solution. But feel free to share new approaches. Thanks! · 5 months, 2 weeks ago
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Solution to problem 22:
Clearly $$a(n)\leq n$$. Hence, $$a(100)\leq100$$
Now, for $$a(200)$$, we need to do the following steps: $a(n)>1+\frac{1}{2}+\left(\frac{1}{4}+\frac{1}{4}\right)+\left(\frac{1}{2^n}+...+\frac{1}{2^n}\right)$
This is an AGP.
Hence, $$a(200)>\left(1-\frac{1}{2^200}\right)+100>100$$.
Therefore options A and D are correct. · 5 months, 2 weeks ago
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Problem 21
Find the equation of the director circle to the circle circumscribing the quadrilateral formed by the lines in order 2x+3y-2 = 0 , x+y =0 , 2x+5y-1 = 0 , 5x+27y-1 = 0
Samarth Agarwal has solved this problem at the first place and provided the solution. But feel free to share new approaches. Thanks! · 5 months, 2 weeks ago
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The equation is $${(x-11/6)}^{2}+{(y-25/6)}^{2}=349/9$$. The steps are same as that of Samarth's solution · 5 months, 2 weeks ago
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Circle curcumscribing quad is l1l2+(lambda)l3l4=0 lambda can be found by cofficient of xy=0
Here lambda came out to be - 0.5
So circle is (x-11/6)^2+(y-25/6)^2=698/36 and directer circle is (x-11/6)^2+(y-25/6)^2=698/18
Is this correct.? · 5 months, 2 weeks ago
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Problem 20:
A series of chords of a parabola $${y}^{2}=4ax$$ are drawn so that their projections on the straight line,which is inclined at an angle $$\alpha$$ to the axis,are of constant length $$c$$. Find the locus of the midpoints of these chords.
Prakhar Bindal has solved this problem at the first place and provided the solution. But feel free to share new approaches. Thanks! · 5 months, 2 weeks ago
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Assume end point of chord in parametric form (at^2 , 2at) and (as^2,2as)
Let The equation of line be y = xtan(alpha)+b
Now find foot of perpendicular from end points onto the line. Using distance formula between them and equate it to c .
Let midpoint be (h,k)
2h = a(t^2 + s^2)
2k = 2a(t+s)
From above two relation find value of t-s and t+s as they will come in expression of distance formula.
Substitute these into that expression and on simplifying further and replacing h and k by x and y.
We obtain locus as
p = alpha (inclination of line)
(y^2 - 4ax) (ycosp+2asinp)^2 + (ac)^2 = 0
Alternate : Find out Length of chord using distance of formula. Then find angle between chord and line by using standard results. And finally take component of length of chord along line and equate to c . That would reduce some of the calculation work .
Credits @Samarth Agarwal for alternate way · 5 months, 2 weeks ago
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I think it should be -(ac)^2 · 5 months, 2 weeks ago
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@Prakhar Bindal
Do you agree with Rohit Ner? If so, then please edit your solution accordingly. And please use latex into your solution to make it understandable. If you need guidance on latex, you can check out this one. Thanks! · 5 months, 2 weeks ago
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No sir saarthak who posted the problem confirmed that the answer is correct · 5 months, 2 weeks ago
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Problem 19:
If ${ \left( 1-{ x }^{ 3 } \right) }^{ n }=\sum _{ r=0 }^{ n }{ { a }_{ r }{ x }^{ r }{ \left( 1-x \right) }^{ 3n-2r } }$ then find $$a_r$$.
Saarthak Marathe has solved this problem at the first place and provided the solution. But feel free to share new approaches. Thanks! · 5 months, 2 weeks ago
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Write $${(1-{x}^{3})}^{n} = {(3x(1-x)+{(1-x)}^{3})}^{n}=\sum _{ r=0 }^{ n }{ { 3 }^{ r } } \binom{ n }{ r }{ (x(1-x)) }^{ r }{ (1-x) }^{ 3n-3r }$$ · 5 months, 2 weeks ago
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Answer is $${3}^{r}\cdot \dbinom{n}{r}$$ · 5 months, 2 weeks ago
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Problem 18:
Consider the ellipse :
$$\dfrac{x^{2}}{25} + \dfrac{y^{2}}{16} = 1$$
Let L be the length of perpendicular drawn from the origin to any normal of the ellipse. Find the maximum value of L.
Bonus : Solve it without calculus and generalize for any ellipse
Aditya Kumar has solved this problem at the first place and provided the solution. But feel free to share new approaches. Thanks! · 5 months, 2 weeks ago
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Solution to Problem 18:
Consider the point $$(5\cos(\theta),4\sin(\theta))$$.
The equation of normal would be: $$5x\sec(\theta)-4y\csc(\theta)$$
Hence, distance $$d=\left| \frac { 9 }{ \sqrt { 25\sec ^{ 2 }{ \left( \theta \right) } +16\csc ^{ 2 }{ \left( \theta \right) } } } \right|$$
To maximise $$d$$, we have to minimise the denominator. By minimising the denominator(did that by calculus), the denominator comes out to be 9.
Hence $$\boxed{d_{max}=1}$$ · 5 months, 2 weeks ago
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Absolutely Correct.
Generalisation for any ellipse x^2 / a^2 + y^2/b^2 = 1
Maximum distance of normal from origin = Modulus (b-a)
Also you could have avoided calculus by using AM Gm in last step by writing sec and cosec in terms of tan and cot · 5 months, 2 weeks ago
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Problem 15:
If N is the number of ways in which 3 distinct numbers can be selected from the set {3, 3^2 ,3^3 ,...... ,3^10 } , so that they form a GP, then find the value of N/5.
Ashu Dablo has solved this problem at the first place and provided the solution. But feel free to share new approaches. Thanks! · 5 months, 2 weeks ago
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@Saakshi Singh
The problem is similar to having to get number of possible Ap's from the set of {1,2,3..10}
So number of possible Ap's is (8+6+4+2)=20
8 for common dif =1 (1,2,3) , (2,3,4) ........(8,9,10)
6 for common dif =2 (1,3,5) , (2,4,6) ........(6,8,10)
4 for common dif =3 (1,4,7) , (2,5,8) ........(4,7,10)
2 for common dif = 4 (1,5,9) and (2,6,10)
So the answer to your question is 4 · 5 months, 2 weeks ago
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the number of possibilities in that order is 8+6+4+2 but the the set containing these in reverse order can also be in gp ie(4,7,10) &(10,7,4) similar is the case with all other elements so the So number of possible GP's is 2(8+6+4+2)=220=40 so N/5 =8 this was also my solution · 5 months, 2 weeks ago
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We have to SELECT the numbers, not arrange them in order, which is why I said the answer is 4. · 5 months, 2 weeks ago
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My answer is 8 (NoteThe following is a table) Difference in power. No terms. Set(of powers) 1. 8. (123,234,...89 10) 2. 6. (135,246....68 10) 3. 4. (147....47 10) 4. 2. (159,2710) Total = 20 But r can be 3^{1,2,3} or 3^{-1,-2,-3} so N = 2x20 = 40 So N/5 =8 · 5 months, 2 weeks ago
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Problem 9:
(On behalf of Akul Agarwal)
If $$\displaystyle f(x)=x+\int _{ 0 }^{ 1 }{ t(x+t)f(t).dt }$$, then find the value of the definite integral,
$\int _{ 0 }^{ 1 }{ f(x)dx }$
Ishan Singh has provided the complete solution to the problem. Thanks! · 5 months, 3 weeks ago
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$$\displaystyle f(x) = x \left(1+\int_{0}^{1} t f(t) \ \mathrm{d}t \right) +\int_{0}^{1} t^2 f(t) \ \mathrm{d}t$$
$$\displaystyle = Ax +B$$ (say)
$$\displaystyle \implies f(x) = x\left(1+\int_{0}^{1} t (At+B) \ \mathrm{d}t \right) + \int_{0}^{1} t^2 (At+B) \ \mathrm{d}t$$
$$\displaystyle = x \left(1+\frac{A}{3}+\frac{B}{2} \right) + \frac{A}{4} + \frac{B}{3}$$
$$\displaystyle \implies Ax+B = x \left(1+\frac{A}{3}+\frac{B}{2} \right) + \frac{A}{4} + \frac{B}{3}$$
Comparing coefficients, we have,
$$\displaystyle A = \frac{65}{23}$$
$$\displaystyle \implies \int_{0}^{1} f(t) dt = A - 1 = \boxed{\dfrac{42}{23}}$$ · 5 months, 3 weeks ago
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Problem 49 :
$$a,b,c,d$$ are real numbers such that,
$$a + 2b + 3c + 4d = 15$$
Find the minimum value of
$$9^{a} + 2\cdot9^{b} + 3\cdot9^{c} + 4\cdot 9^{d}$$
Vignesh S has posted the solution to this problem. Feel free to add new approaches. Thanks! · 5 months ago
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The answer is 270 Let $f(x)=9^{a}+2\cdot 9^{b}+3\cdot 9^{c}+4\cdot 9^{d}$ and $g(x)=a+2b+3c+4d$. Using Lagrange Multipliers we have $\dfrac{\partial{f(a,b,c,d)}}{\partial x}=k \times \dfrac{\partial{g(a,b,c,d)}}{\partial x}$ where $$x=a,b,c,d$$ $\dfrac{\partial{(9^{a}+2\cdot 9^{b}+3 \cdot 9^{c}+4 \cdot 9^{d})}}{\partial x}=k \dfrac{\partial (a+2b+3c+4d)}{\partial x}$ $\ln(9) \cdot 9^{a}=k \times1$ Similarly doing for b,c,d we have $2\ln(9)\cdot 9^{b}=k \times 2$ $3\ln(9)\cdot9^{c}=k \times 3$ $4\ln(9) \cdot 9^{d}=k \times4$ $\implies a=b=c=d$. So substituting in $$g$$ the above condition we get $10a=15\implies a=1.5$ Therefore $\inf{f(x)}=27×(1+2+3+4)=270$ · 5 months ago
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the given expression (S) whose minimum value is to be calculated can be written as
S = 9^a + 9^b + 9^b + 9^c + 9^c + 9^c + 9^d + 9^d + 9^d + 9^d
Now applying AM - GM inequality
S/10 >= ( 9 ^(a+2b+3c+4d) )^1/10
S/10 >= 9^(15/10)
S/10 >= 9^3/2 = 27
Therefore S >= 270
and hence minimum value of S is 270 · 4 months, 2 weeks ago
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Look who's back from the dead. · 4 months, 2 weeks ago
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@Vignesh S
Please post the next problem(Problem 50) of the contest. And after this problem on this note, the contest will be continued on JEE-Advanced Maths Contest(Continued) note.
Thanks! · 5 months ago
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The answer is correct. · 5 months ago
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https://www.physicsforums.com/threads/does-the-following-cross-product-identity-always-work.889432/ | # B Does the following cross product identity always work?
1. Oct 16, 2016
### em370
Mod note: Reproduced contents of image with broken link:
i = j x k
j = k x i
k = i x j
Wikipedia says this about the standard basis vectors. Does this work for all (i.e, non basis) vectors? For example, if you know A = B X C does that mean C = A X B and B = C X A?
Last edited by a moderator: Oct 17, 2016
2. Oct 16, 2016
### Fightfish
Nope. Let's start with $A = B \times C$ and see what $A \times B$ gives us. Using the vector triple product identity, we have $A \times B = (B\times C) \times B = C (B\cdot B) - B (B \cdot C)$. So, $A \times B = C$ only if $B$ and $C$ are orthogonal (i.e. their dot product is zero) - which is true for the standard basis vectors, but not true in general.
3. Oct 16, 2016
### Staff: Mentor
Have you tried $A=0$?
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https://codegolf.stackexchange.com/questions/16217/cardinal-numbers-in-standard-american-english/16219 | # Cardinal Numbers in Standard American English
Let n be any integer between 1 and 999,999 inclusive. Your challenge is to write a complete program which using stdin or command-line arguments takes in n and outputs the number of times the letter "o" is needed to write all cardinal numbers in standard American English between 1 and n. You can assume that n will always be an integer within the above given range.
You can just use all lowercase letters as I do below. So we count all "o". No need to worry about uppercase "O".
Here is a quick review of how to write English numerals in American English.
one two three four ... nine ten eleven twelve thirteen fourteen ... nineteen twenty
twenty-one twenty-two ... twenty-nine thirty ... forty ... fifty ... sixty ...
seventy ... eighty ... ninety ... one hundred ... two hundred ... three hundred ...
nine hundred ... one thousand ... two thousand ... nine thousand ... ten thousand ...
eleven thousand ... ninety-nine thousand ... one hundred thousand ...
two hundred thousand ... nine hundred ninety-nine thousand nine hundred ninety nine.
The hyphen for two digit numbers doesn't matter.
The commas don't matter of course. I excluded them above.
Separation between hundreds and tens doesn't matter because we are only counting the letter "o" so 110 can be written as "one hundred ten", or "one hundred and ten". I excluded the "and" above.
For this challenge "hundred" and "thousand" must be preceded by "one" instead of "a" when being used at the beginning of the number. So 1111 must be "one thousand one hundred eleven" instead of "a thousand one hundred eleven".
Here are some more random numerals to clarify.
219873 = two hundred nineteen thousand eight hundred seventy three
615023 = six hundred fifteen thousand twenty three
617610 = six hundred seventeen thousand six hundred ten
423716 = four hundred twenty-three thousand seven hundred sixteen
386031 = three hundred eighty-six thousand thirty one
Here are some samples for what your code should return.
./mycount 1
1
There's only "one" to write so we need only a single "o".
./mycount 10
3
We only need three o's namely in "one", "two", and "four".
./mycount 101
41
Your code must be self-contained and must not connect to the internet, download any files, perform any query, etc. I can already see somebody using google or mathematica with wolfram alpha to do this.
True code-golf. The shortest code in any language wins. Please post your code with some test cases. In the case of ties, I pick the one with the highest upvotes after waiting at least for two weeks. So everyone feel free to upvote any solutions you like.
Happy coding!
• – primo Dec 27 '13 at 5:02
• There are so many missing ands I just dropped my biscuit in my cuppa – Bojangles Dec 28 '13 at 14:41
• I think American numbers and numbers in English have the same amount of os - the only difference I know is the ands. – bcsb1001 Mar 14 '15 at 20:51
## R - 54
sum(nchar(gsub("[^o]","",english::english(1:scan()))))
I get 41 for n=101. I hope someone can confirm.
• This will not work if the package english has not been installed. To be fair, you should add the command necessary for installing the package. – Sven Hohenstein Dec 27 '13 at 10:38
• I disagree. I have never seen such comment for python answers that contain import X or perl answers with use Y, etc. Having the necessary packages/modules installed is always a given. – flodel Dec 27 '13 at 12:16
• OK, now I see the point. – Sven Hohenstein Dec 27 '13 at 13:05
• Yes, this works for me, too, although takes 2 seconds for 10000 and 25 seconds for 100000. For 999999, I got 2359000, which took 6 minutes. Nice! – Andreï Kostyrka Feb 28 '16 at 11:18
## JavaScript 1.8 (150)
function f(n)n<14?(22>>n)&1:n<100?((n/10|0)==4)+f(n%10):n<1e3?f(n/100|0)+f(n%100):f(n/1e3|0)+f(n%1e3)+1;m=readline();for(s=i=0;i++<m;)s+=f(i);print(s)
As written, this will only work in SpiderMonkey js (the one used by Anarchy Golf). If running this in Firefox, replace readline with prompt and print with alert. Use of Mozilla's nonstandard "expression closures" feature means this will not work in any other interpreter unless you insert {return and } in the necessary places (at a cost of 7 characters).
Original test cases:
• 1 → 1
• 10 → 3
• 101 → 41
• 1020 → 726
• 21667 → 40173
• 120000 → 262002
• 999999 → 2359000
# C - 147 148 157 163 166 172 200
C is the right tool for the job
s;l(x){s+=(22>>x%10&1)+(x/10%10==4)-!((x+89)/2%50);x&&l(x/100%10);}main(x,v)int**v;{for(x=atoi(v[1]);x;x--)l(x),l(x/1000),s+=x>999;printf("%d",s);}
Original tests:
• 1 -> 1
• 10 -> 3
• 101 -> 41
• 1020 -> 726
• 21667 -> 40173
• 120000 -> 262602
• 999999 -> 2359000
Plus some of my own random tests: http://qp.mniip.com/p/cy
# Mathematica 49 58 50 bytes
Without a library or internet access.
StringCount[""<>IntegerName[Range@#,"Words"],"o"]&
Note:
"Words" guarantees that no digits will be left untranscribed into English.
This incorrectly returns one "o". (Emphasis added.)
IntegerName[1020]
1 thousand 20
This yields two "o"'s, as required. (Emphasis added.)
IntegerName[1020,"Words"]
one thousand, twenty
Example
StringCount[""<>IntegerName[Range@#,"Words"],"o"]&[1020]
726
# Moo - 137 bytes
s=$string_utils;m=player;i=0;for a in[1..toint(read(m))]i=i+length(s:strip_all_but(s:english_number(a),"o"));suspend(0);endfor m:tell(i); The suspend(0) is necessary to avoid a Task ran out of ticks for high inputs. Also, this code takes quite a long time to run for very high numbers. ## Perl - 384 #!/usr/bin/perl @b=qw(1 1 1 0 1 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 0 0 1); sub b($){my($b,$m)=shift;if(20>$b){$b[$b];}elsif(100>$b){$m=$b%10;
$b[(($b-$m)/10)+18]+($m?b($m):0);}elsif(1000>$b){$m=$b%100;
b(($b-$m)/100)+($m?b($m):0);}elsif(1000000>$b){$m=$b%1000; b(($b-$m)/1000)+1+($m?b($m):0);}} sub c($){my$c=shift;my$d=0;$d+=b($c--)while($c);$d;}
print c(\$_)."\n"while(<>);
this would run faster with caching but that would increase my score | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.26469144225120544, "perplexity": 4202.679727247361}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-26/segments/1560627999615.68/warc/CC-MAIN-20190624150939-20190624172939-00195.warc.gz"} |
https://stats.stackexchange.com/questions/393646/understanding-the-details-of-expectation-maximizationem-for-estimating-the-par | Understanding the details of Expectation Maximization(EM) for estimating the parameters?
When using the Expectation Maximization(EM) for estimating the parameters, every time I came across a different problem I see a totally different representation of the likelihood/Expectation function and a different formula in the E-step & M-step i.e. one guy adds extra terms, another remove some terms, yet another bring new ways (tricks) to solve it.
1. Is there a standard way which we can use it as a rule, not like saying E-step is the Expectation of the Likelihood and M-step is maximizing it?
2. in EM algorithm there is an expectation of the log-likelihood with respect to the posterior/conditional distribution of the hidden variables i.e. $$E_{p(y|x,\theta)}(log(p(x,y|\theta))$$. And we know that $$p(x,y|\theta)=p(y|x,\theta)\times p(x|\theta)$$ i.e. it should be sufficient to find a formula of $$p(y|x,\theta)$$ for calculating $$p(x,y|\theta)$$ because $$p(x|\theta)$$ is the frequency of x in the dataset which should be known. However, I have come through several EM applications/examples and I did not find anyone using this rule, rather all of them use a different and direct (i.e. without depending on $$p(y|x,\theta)$$ ) formula for $$p(x,y|\theta)$$. So what is the reason behind that? Isn't it easier to use this rule for finding $$p(x,y|\theta)$$ instead of trying to find two unique formulas for $$p(y|x,\theta)$$ and $$p(x,y|\theta)$$ for caluclating the expectation.
• $p(x|\theta)$ is not the frequency of $x$ in the data set, it's the probability density of $x$ given $\theta$. If $x$ were drawn from a continuous distribution, each value of $x$ in a data set of size $n$ would appear once, i.e., with frequency $1/n$, so $p(x|\theta$) would disappear from the set of formulae altogether. – jbowman Mar 11 '19 at 3:05
• If you know $p(x,y|\theta)$, you know $p(y|x,\theta)$ up to the constant of integration. It is often quite easy to see what that is just by looking at $p(x,y|\theta)$. – jbowman Mar 11 '19 at 3:10
• @jbowman I did not get your point buddy. Could you clarify more what you mean. – Mosab Shaheen Mar 11 '19 at 3:22
• With reference to your last sentence, it's the case that it's often easier to work with $p(x,y|\theta)$. – jbowman Mar 11 '19 at 14:19
• @jbowman I think you did not get the point. I am saying that in all the applications of EM algorithm I came across, I saw people use different formulas for p(x,y|θ) and p(y|x,θ). You are saying p(x,y|θ) is easier to find. Fine, but then my question is why do not they use p(y|x,θ) = p(x,y|θ)/p(x|θ) ?? why do they always use two unique formulas for both p(y|x,θ) and p(x,y|θ) and those formulas do not directly use p(x|θ) (if they use p(x|θ) then one formula will be enough and p(x|θ) is very easy to find by counting). – Mosab Shaheen Mar 11 '19 at 21:41
The EM method is a generalized algorithm that solves maximum-likelihood problems with latent variables. Suppose that you have a model with some random variables $$y$$ that you have observed (measurements) and some random variables $$z$$ that are unknown. We write this model as a joint probability distribution $$p_\theta(y,z)$$ where $$\theta$$ are the parameters that you want to estimate.
The problem now is that we cannot do maximum likelihood on this model because we do not known what to put in for the $$z$$ variables.
One way to solve this problem is marginalization: we remove the unknown random variables from the model by integrating them out with $$p_\theta(y) = \int p_\theta(y,z) \mathrm{d} z.$$
In most interesting cases this integral cannot be solved in closed form. This is where the EM method comes to help. It is an iterative procedure that starts from any initial estimate $$\theta^{(0)}$$ and iterates two steps.
In the first (the E-step) we create a lower bound on the likelihood function $$\log p_\theta(y)$$ by computing $$Q(\theta,\theta^{(k)}) = \mathbf{E}\{\log p_\theta(y,z)\}$$ where the expectation is taken with respect to the best estimate of the conditional distribution of the latent variables $$p_{\theta^{(k)}}(z|y)$$.
In the second step (the M-step) we maximize the lower bound to update the parameter estimate: $$\theta^{(k+1)} = \arg \max_\theta Q(\theta,\theta^{(k)}).$$
Under some regularity conditions, $$\theta^{(k)} \to \theta_0$$ where $$\theta_0$$ is a local maximum of the marginal likelihood $$p_\theta(y)$$.
There are a lot of tricks you can use to solve the E-step and the M-step. Most notably
• if $$p_\theta(y,z) = q_\theta(y,z)g(y,z)$$ where $$g(y,z)$$ is independent of $$\theta$$, you can disregard the whole $$g(y,z)$$ in computing $$Q(\theta,\theta^{(k)})$$ because that part will not impact the successive maximization step. This is very useful in hierarchical models: suppose that the joint model is $$p_\theta(y,z) = p(y|z_1)p(z_2|z_3)p_\theta(z_3|z_4)p(z_4)$$, in the E-step we just need to consider $$Q(\theta,\theta^{(k)}) = \mathbf{E}\{\log p_\theta(z_3|z_4)\}$$ because all other factors are independent of $$\theta$$!
• You can freely add as many variables as you want to the model: these will anyway be integrated out by the EM method! This is especially useful if you can separate parameters given a variable. Suppose that your model depends on two parameters $$p_{\theta_1,\theta_2}(y)$$. If there is a random variable $$z$$ such that $$p_{\theta_1,\theta_2}(y,z) = p_{\theta_1}(y|z)p_{\theta_2}(z)$$, then the EM method gives you two functions $$Q_1(\theta_1,\theta^{(k)}) = \mathbf{E}\{\log p_{\theta_1}(y|z)\}$$ and $$Q_2(\theta_2,\theta^{(k)}) = \mathbf{E}\{\log p_{\theta_2}(z)\}$$ (where all expectations are taken with respect to $$p_{\theta^{(k)}}(z|y)$$. Similarly, the M-step splits into two different optimization problems: $$\theta_1^{(k+1)} = \arg\max_{\theta_1} Q_1(\theta_1, \theta^{(k)}),$$ and $$\theta_2^{(k+1)} = \arg\max_{\theta_2} Q_2(\theta_2, \theta^{(k)}).$$
Sadly (as you may guess from my examples) there is no general way to solve a problem with EM... it all depends on the structure: How easy is it to compute $$p(z|y)$$? How easy is it to take expectations with respect to it? Which latent variables $$z$$ may I need to make the problem simpler? Which part can I disregard?
WARNING: notation changes w.r.t. the previous section!
What formulas you use really depend on your model; all in all what you want to solve is $$\hat \theta = \arg \max \log p(x|\theta)$$ where $$x$$ is the data. The key assumption is that $$p(x|\theta)$$ is not available in closed form or is complicated to work with (if it were easy, you would just maximize it and be happy!). Instead, you have access to $$p(x,y|\theta)$$ and you use the EM method to solve $$\hat \theta = \arg \max \log \int p(x,y|\theta) \mathrm d y.$$ In this example the variable $$y$$ is the latent variable which you introduce to make the problem tractable. Consider for instance the mixture of two Gaussians $$p(x|\theta) = \alpha N(x|m_1,\sigma_1^2) + (1-\alpha)N(x|m_2,\sigma_2^2).$$
Estimating $$\theta = {\alpha,m_1,\sigma_1,m_2,\sigma_2}$$ from data can be either done directly using numerical optimization; or introducing a latent variable $$y$$ that tells you which of the mixtures the datapoint belongs to. Then we have the conditional densities (the likelihoods) $$p(x|y=1,\theta) = N(x|m_1,\sigma_1^2)\qquad p(x|y=2, \theta) = N(x|m_2,\sigma_2^2).$$ We apply the EM method by computing, at each iteration, the probability that a sample belongs to either mixture (i.e. $$p(y=i|x,\hat\theta^{(k)}$$) and then maximizing the likelihood of the parameters using this probability assignment.
If $$z$$ are discrete random variables (say, the outcome of a draw of cards), then the expectation with respect to the latent variables is effectively a sum: $$\mathbf E\{\log p_\theta(y,z)\} = \sum_{i=1}^M r_i \log p_\theta(y,z_i)$$ where $$r_i$$ denotes the probability of outcome $$z_i$$ given the observed data (for the parameter value $$\theta^{(k)}$$): $$r_i = p(z_i | y; \theta^{(k)}).$$
In the previous discourse, $$y$$ denoted a set of observations. In case we have $$y = \{y_j\}_{j=1}^N$$ where each measurement $$y_j$$ is drawn from some distribution $$p_\theta(y)$$, then we have that the joint distribution is $$\log p_\theta(y) = \sum_{j=1}^N \log p_\theta(y_j).$$
In this case, $$Q(\theta,\theta^{(k)}) = \mathbf{E}\{ \log p_\theta(y,z)\} = \sum_{j=1}^N \mathbf{E}\{\log p_\theta(y_j,z)\}.$$ Combining this with the discussion at the previous point, we have that in case $$z_i$$ are discrete outcomes,
$$Q(\theta, \theta^{(k)}) = \sum_{j=1}^N\sum_{i=1}^M r_{i,j} \log p_\theta(y_j,z_i).$$ where $r_i = p(z_i|y_j;\theta^{(k)}).$$• Thanks. you mentioned "if$p_\theta(y,z) = q_\theta(y,z)g(y,z)$where$g(y,z)$is independent of$\theta$...." what if$p_{\theta}(z|y) = p_{\theta}(z,y)/p(y)$shall we ignore p(y) because it is independent of$\theta$? – Mosab Shaheen Apr 3 '19 at 14:15 • Also what if z is a sequence like in Part of Speech tagging, where z is a sequence like (noun, verb, preposition, adjective, noun) and y is the sentence like (he, went,to, beautiful, place) then if we take$ p_\theta(y) = \Sigma_{z} p_\theta(y,z)$in this case what will be the values of z. As I said z is a sequence of a length that is equal to the length of the sentence y and if we do not know y beforehand then we can not know the length (number of elements) of the sequence z – Mosab Shaheen Apr 3 '19 at 14:31 • and even suppose we knew the length of z is n then there are$n^{M}$possible sequences where M is the number of Parts of Speech in English. So how can we pick z values in this case (if z is only a part (not parts) of speech i.e. an element (not a sequence) then we have only M values possible for z but in the case where z is a sequence how can we deal with that in the Expectation Maximization Algorithm? – Mosab Shaheen Apr 3 '19 at 14:31 • I am asking this because I have already seen papers using EM for Part of Speech tagging but they did not mention the details. – Mosab Shaheen Apr 3 '19 at 14:34 • And Last point, sometimes I find people writing$ \theta^{(k+1)} = argmax_{\theta^{'}} \mathbf{E}\{\log p_\theta(y,z)\} = argmax_{\theta^{'}} \Sigma_{(z,y) \in (Z,Y)} p(z|y, \theta) \log p(z,y|\theta)$and other times, as what you mentioned,$argmax_{\theta^{'}} \Sigma_{(z \in Z)} p(z|y,\theta) \log p(z,y|\theta)\$ in other words should not we take all the combinations of both the hidden and observed variables (z,y) or we should take only one sample from the data with all the possible values of (z). – Mosab Shaheen Apr 3 '19 at 14:57 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 67, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9603085517883301, "perplexity": 275.2901623306069}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-10/segments/1581875145981.35/warc/CC-MAIN-20200224193815-20200224223815-00549.warc.gz"} |
http://physics.stackexchange.com/questions/126176/is-the-apparent-lack-of-ricci-curvature-in-the-schwarzschild-metric-due-to-a-c | # Is the apparent lack of (Ricci) curvature in the Schwarzschild metric due to a choice of coordinates?
I've been lightly studying GR lately. Something that has been bothering me has been the lack of (Ricci) curvature produced from the Schwarzschild metric in the few lectures I've watched, as well as the few snippets of text book I've been able to read. Why is there no (Ricci) curvature outside this spherically symmetric, non-rotating, uncharged body that still has mass? Shouldn't there always be curvature in the presence of mass or am I missing something? I've read a bit about certain information that is unobtainable when dealing with Schwarzschild coordinates, is the curvature outside the body one of the specific quantities that cannot be defined with these coordinates?
-
There are many ways to measure curvature (and more than one type of curvature). The Ricci scalar is one of them, but the Riemann tensor is the one we use to say whether a spacetime is curved or not, and it is nonzero for the Schwarzschild metric, therefore it is curved. – auxsvr Jul 12 '14 at 13:53
"Shouldn't there always be curvature in the presence of mass... ?" -- There is no curvature inside a spherically symmetric shell: spacetime is flat there. So it's not true that the presence of mass necessarily guarantees that spacetime is everywhere non-flat. – Stan Liou Jul 12 '14 at 14:10
I suspect you're getting confused by the fact that the Ricci tensor $R_{\mu\nu} = 0$ and therefore the scalar curvature $g^{\mu\nu}R_{\mu\nu} = 0$. This is always the case in regions of space where the stress-energy tensor is zero. The curvature is certainly not zero in the sense that spacetime is flat. For example the Kretschmann scalar is non-zero:
$$R_{abcd} R^{abcd} = \frac{12 r_s^2}{r^6}$$ | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9309998750686646, "perplexity": 162.78495339785397}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-14/segments/1427131298755.8/warc/CC-MAIN-20150323172138-00210-ip-10-168-14-71.ec2.internal.warc.gz"} |
http://web.iit.edu/gaa/latex-step-7 | # LaTeX Step 7
STEP 7: Sample File and Your Thesis
sample3 is a sample file prepared using the iitthesis_class style file. It is recommended that you run this sample file in LaTeX and see the dvi or pdf output files that are generated in the same folder. Note that the style file should be in the same folder as your tex file (sample3) to avoid compile errors. The font files (font12, font11) should also be in that folder.
Begin by making a folder (e.g. mythesis) on your disk and copy thesis_class style file and font12font11 font files there. Open a new file in your editor (e.g. WinEdt) and save it in mythesis folder. Then define the style file for your thesis using /documentclass{} command. You may easily copy and paste the needed macro commands from sample3 into your file and change the arguments only. You can compile your file and make dvi, ps or pdf outputs any time during your work. If your thesis has a bibliography, the following steps should be taken to generate correct outputs:
1. Run LaTeX, generating a list of \cite references in its auxiliary file (.aux).
2. Run BibTeX, which reads the auxiliary file, and looks up the references in databases (.bib files) and writes a file with bbl extension.
3. Run LaTeX again, which reads the bbl file
4. Run LaTeX a third time, resolving all references.
If you are using WinEdt, you need to click on dvi preview icon to generate the dvi file and view it. To create the pdf output file, first do dvi to ps conversion by clicking on , and then ps to pdf conversion with icon. Note that a pdf file created with a conversion from dvi to pdf directly will not contain eps figures at the pdf output file. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9746932983398438, "perplexity": 3474.7615190499187}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-26/segments/1498128320863.60/warc/CC-MAIN-20170626184725-20170626204725-00247.warc.gz"} |
http://www.cut-the-knot.org/wiki-math/index.php?n=Algebra.ViEgraveTesFormulas?setview=big&setfontsize=110 | Viète's Formulas
Due to the Fundamental Theorem of Algebra, an n-th polynomial P_{n}(x) has n complex roots that I shall denote \alpha_1, \ldots \alpha_n. A polynomial P(x) with root \alpha has a linear factor of x-\alpha which means that P(x)=(x-\alpha )Q(x), for some polynomial Q(x). It follows that a polynomial P_{n}(x) could be written as a product of linear factors:
P_{n}(x)=a(x-\alpha_{1})(x-\alpha_{2})\cdot\ldots\cdot(x-\alpha_{n}),
where a is the leading coefficient, i.e., the coefficient by x^{n}. Multiplying out we obtain what is known as Viète's formulas for the coefficients of a polynomial. Assume
P(x) = c_{0}x^{n}+c_{1}x^{n-1}+c_{2}x^{n-2}+\ldots + c_{n-1}x+c_{n} = \sum^{n}_{i=0}c_{i}x^{i},
where c_{0}=a is a constant. Then in terms of the roots,
c_{k}/a=(-1)^{k}\sum\alpha_{i_{1}}\alpha_{i_{2}}\cdot\ldots\cdot\alpha_{i_{k}},
where the sum is over all k-element subsets \{i_{1},i_{2},\ldots,i_{k}\} of \{1,2,\ldots,n\}. A polynomial is the generating function of its coefficients.
Polynomials \sum\alpha_{i_{1}}\alpha_{i_{2}}\cdot\ldots\cdot\alpha_{i_{k}} are known as (elementary) symmetric (in their arguments - \alpha's) because they do not change under any permutation of the arguments. Symmetric polynomials c_{k} are homogeneous of degree k.
For a second degree - quadratic - polynomial P(x)=ax^{2}+bx+c, with just two roots \alpha_1 and \alpha_2, Viète's formulas are simple:
\frac{b}{a} = -(\alpha_{1}+\alpha_{2}),
\frac{c}{a} = \alpha_{1}\alpha_{2}.
To verbalize, \frac{b}{a} is the sum of the roots taken with the sign minus while \frac{c}{a} is the product of the roots. We can obtain the same result in a slightly different manner. Rewrite the polynomial equation P(x)=ax^{2}+bx+c=0 that defines the roots as
x+\frac{c}{ax}=-\frac{b}{a}.
Observe that in the left there is the sum of two quantities - x and \frac{c}{ax} - whose sum is naturally -\frac{b}{a} and whose product is
x\cdot\frac{c}{ax}=\frac{cx}{ax}=\frac{c}{a},
both of which chracterize the roots of the equation. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9703965187072754, "perplexity": 1068.7943295830157}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-47/segments/1510934809419.96/warc/CC-MAIN-20171125051513-20171125071513-00034.warc.gz"} |
https://mathoverflow.net/questions/150744/the-line-graphs-of-complete-graphs-and-cayley-graphs | # The line graphs of complete graphs and Cayley graphs
Let $n>3$ be an odd integer and let $K_n$ denote the complete graph on $n$ vertices. For which integers $n$ the line graph $L(K_n)$ is a Cayley graph? For even $n$, it follows from a result of Watkins that $L(K_n)$ is not a Cayley graph. For $n=5$, $L(K_n)$ is the complement of the Petersen graph and so it is not a Cayley graph.
If $L(K_n)$ is a Cayley graph for the group $G$, then $G$ is 2-homogeneous on $V(K_n)$, that is, it acts transitively on the set of unordered pairs of vertices of $K_n$. However it is not 2-transitive. Kantor "Automorphism groups of designs" determines the 2-homogeneous groups that are not 2-transitive. He finds that such groups exist if and only if $n$ is a prime power congruent to 3 mod 4, and therefore these are the only values of $n$ for which $L(K_n)$ is a Cayley graph. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8611388206481934, "perplexity": 54.1697246201163}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-29/segments/1593657140337.79/warc/CC-MAIN-20200712211314-20200713001314-00076.warc.gz"} |
https://jmbh.github.io/Deconstructing-ME/ | Yesterday, I read ‘Measurement error and the replication crisis’ by Eric Loken and Andrew Gelman, which left me puzzled. The first part of the paper consists of general statements about measurement error. The second part consists of the claim that in the presence of measurement error, we overestimate the true effect when having a small sample size. This sounded wrong enough to ask the authors for their simulation code and spend a couple of hours to figure out what they did in their paper. I am offering a short and a long version.
Edit Feb 17th: After a nice email converstaion with the authors, I now know that they do make their general argument only under the condition of selecting on significance. Their result then trivially follows from the increased variance of the sampling distribution due to adding ‘measurement error’ (see section (3) below). My source of confusion was that they talk about selection on significance in the paper, but then do not select on significance in the two scatter plots, and incorrectly state in the figure title, that they do. The conclusions of this blog post are still valid when making the assumptions in (1), so I leave it online in case somebody finds (parts of) it interesting.
The Short Version
My conclusion is that the authors show the following: If an estimator is biased (here by the presence of measurement error), then the proportion of estimates that overestimate the true effect depends on the variance of the sampling distribution (which depends on $N$). While this is an interesting insight, the authors do not say this clearly anywhere in the paper. Instead, they use formulations that suggest that they refer to the expected value of the estimator, which does not depend on the sample size. To make things worse, they plot the estimates in a way that suggest that the variance of the estimators is equal for N = 50 and N = 3000 and that the effect is driven by a difference in expected value, while the reverse is true.
The Long Version
I try to make an argument for my claims in the ‘short version’ above in 6 steps. (1) We make clear what the claim is the authors make, (2) we define our terminology, (3) we investigate what adding measurement error does on the population level, (4) we see how this influences the characteristics of estimators based on different sample sizes, (5) we summarize our results and (6) get back to the paper.
(1) The exact claim
The authors write ‘In a low-noise setting, the theoretical results of Hausman and others correctly show that measurement error will attenuate co- efficient estimates. But we can demonstrate with a simple exercise that the opposite occurs in the presence of high noise and selection on statistical significance.’ (p. 584/585). From this we can deduce that the authors claim that ‘In a high noise setting, the presence of measurement error and selection on statistical significance leads to an increase in coefficient estimates’. However, the authors do not select on statistical significance in their simulation, hence we also drop this condition and arrive at the claim ‘In a high noise setting, the presence of measurement error leads to an increase in coefficient estimates’.
What this statement means is unclear to me. Under the reasonable assumption that the authors did not make a fundamental mistake, the rest of this blogpost is about finding out what the authors could have meant.
(2) Terminology (for reference)
In the paper, ‘measurement error’, ‘noise’ and ‘variance’ are used interchangeably. Here, with variances we refer to the variances of the dimensions of the bivariate Gaussian distribution, if not stated otherwise. With measurement error we mean another bivariate Gaussian distribution with zero covariance. By a noisy setting, we refer to a situation with a low signal to noise ratio. This is defined relative to another setting, which is less noisy. The signal to noise ratio is a function of $N$ and is related to the variance of the sampling distribution of the estimator. All these things will become clear in sections (3) and (4).
(3) What does ‘adding measurement error’ mean on the population level?
In order to evaluate the above claim with respect to the simulation setup of the authors, we need to know the simulation setup. Fortunately, the authors provided the code in a quick and friendly email.
The authors consider the problem of estimating the covariance of a bivariate Gaussian distribution from a finite number of observations. The bivariate Gaussian distribution has the density
where in our case the covariance $cov(x_1, x_2) = r > 0$ is some positive value, so the covariance matrix $\Sigma$ has entries:
Note that if we scale both dimensions of the Gaussian to $\mu_1 = \mu_2 = 0$ and $\sigma_1 = \sigma_2 = 1$ the correlation coefficient is equal to the coefficient of the regression of $x_1$ on $x_2$ or vice versa. Thus all results obtained here also extend to the regression coefficient that is refered to in the paper.
Now the authors ‘add measurement error’ to the two variables which consists of independent Gaussian noise with a variance $k > 0$, where $k$ is a constant. Notice that these two variables can also described by a bivariate Gaussian with covariance matrix $\Sigma^{ME}$:
Notice that adding ‘measurement error’ as done by the authors is the same as adding these two Gaussians. Addition is a linear transformation and hence the resulting distribution is again a bivariate Gaussian distribution. Indeed, it turns out that the covariance matrix $\Sigma^A$ of the resulting bivariate Gaussian is the sum of the covariance matrices $\Sigma$ and $\Sigma^{ME}$ of the two bivariate Gaussians:
Now, if we renormalize the variances to get back to a correlation matrix it becomes obvious that adding ‘measurement error’ has to decrease the absolute value of the covariance:
Note that $k > 0$ and hence $\frac{r}{k + 1} < r$ and hence the absolute value of the covariance is smaller in \Sigma^{A_{norm}} than in $\Sigma$ in the population.
(4) Properties of the Estimator
We now consider the estimate $\hat \sigma_{1,2}$ for the covariance between $x_1$ and $x_2$ in the bivariate Gaussian with covariance matrix $\Sigma^{A_{norm}}$ which is ‘corrupted’ by measurement error. We obtain $\hat \sigma_{1,2}$ via the least squares estimator, which is an unbiased estimator for $\frac{r}{k + 1}$.
What does this mean? This means that by the Central limit theorem, the sampling distribution will be a Gaussian distribution that is centered on the true coefficient, which is $\frac{r}{k + 1}$. Thus, if we take many samples of size $N$ and compute a coefficient estimate on each of them, the mean coefficient will be equal to $\frac{r}{k + 1}$:
From the fact that the Gaussian density is symmetric and centered on the true effect, it follows that $\hat \sigma_{1,2}$ will equally often under- and overestimate the true effect $\frac{r}{k + 1}$. It is important to stress that this is true, irrespective of the variance of the sampling distribution (which depends on $N$). We illustrate this in the following Figure which shows the empirical sampling distributions from the simulation of the authors:
The solid black line indicates the density estimate of the empirical sampling distribution of the coefficient estimates in the low noise (N = 3000) case. The solid red line indicates the density of the empirical sampling distribution of in the high noise (N = 50) case. The dashed black and red lines indicate the arithmetic means of the corresponding sampling distributions. The green dashed line indicates the true coefficient of the bivariate Gaussian with added measurement error. Now, as predicted from the fact that $\hat \sigma_{1,2}$ is an unbiased estimator independent of $N$, we see that the mean parameter estimates in both low/high noise setting (black/red dashed lines) are close to the true coefficient $\frac{r}{k + 1}$ (dashed green line).
Before moving on, we define $\mathcal{P}^\uparrow \in [0,1]$ as the proportion of coefficient estimates that are larger than the true effect $r$ and hence overestimate it. $\mathcal{P}^\uparrow_H$ refers to that proportion in the high noise (small $N$) setting, $\mathcal{P}^\uparrow_L$ refers to that proportion in the low noise (large $N$) setting.
Now, the second important observation is that for both noise settings we have $\mathcal{P}^\uparrow_H = \mathcal{P}^\uparrow_L = \frac{1}{2}$, which implies that we equally often under- and overestimate the true effect. Note that another way of saying this is that the area under the curve left of the green line is equal to the area under the curve right to the orange line, for both sampling distributions.
We now make the crucial step by considering $\hat \sigma_{1,2}$ not as an estimate for the covariance $\frac{r}{k + 1}$ in $\Sigma^{A_{norm}}$, but for the covariance $r$ of the ‘true’ bivariate Gaussian without added measurement error with covariance matrix $\Sigma$. We know that $\hat \sigma_{1,2}$ is an unbiased estimator for $\frac{r}{k + 1}$ and we know $\frac{r}{k + 1} < r$. From this follows that $\hat{\sigma}_{1,2}$ is a biased estimator for $r$. Specifically, the estimator is biased downwards.
We again look at the proportions of coefficient estimates that under- and overestimate the true effect $r$ (the dashed blue line in the figure). We first consider the low noise case: the first observation is that we overestimate $r$ less often than we overestimated $\frac{r}{k + 1}$, which implies $\mathcal{P}^\uparrow_L < \frac{1}{2}$. Again, this is the same as saying that the area under the curve on the right of the blue line is smaller than the area under the curve left to the blue line.
For the high noise case the exact same is true, i.e. $\mathcal{P}^\uparrow_H < \frac{1}{2}$. Let’s define $q := \frac{\mathcal{P}^\uparrow_H}{\mathcal{P}^\uparrow_L}$. Now what we do we have is that $\mathcal{P}^\uparrow_H > \mathcal{P}^\uparrow_L$ and hence $q > 1$. This means that in the presence of measurement error, we overestimate absolutely less often than we underestimate in all settings, however, we overestimate relatively more in a high noise (small $N$) setting compared to a low noise (large $N$) setting. Let’s let this sink in for a moment and then move on to the summary:
(5) Summary
What have we found? We found that if our estimator is biased downwards (here by measurement error), then different sample sizes (and hence different variances of the sampling distribution) lead to different proportions of coefficient estimates that overestimate the true effect.
However, it is important to stress: when keeping $N$ constant and introducing measurement error, the proportion of overestimating estimates decreases compared to the situation without measurement error. This is because the whole sampling distribution is shifted towards zero in the presence of measurement error (the blue line is shifted to the position of the green line in the Figure).
The only thing that is increasing is $q$, which means that in the presence of measurement error in a high noise setting (small $N$) we relatively overestimate more than in a low noise setting (high $N$). What determines $q$? The larger the difference between the variances of two sampling distributions, the larger $q$. The more we shift the sampling distribution towards zero (by adding measurement error), the larger $q$.
(6) Back to the Paper
I think the results stated in (5) are pretty far away from the claim in the paper, which was ‘In a high noise setting, the presence of measurement error leads to an increase in coefficient estimates’. This statement rather suggests that introducing measurement error increases the expected value of the sampling distribution (moving the blue line to the right instead of to the left) which is - as we have seen - incorrect. This false suggestion is strengthened by the scaling of the figures. We illustrate this here, by plotting the figure as shown in the paper (top row) and with equal coordinate systems (bottom row).
The top row suggests that the difference between the low/high noise setting is because the whole cloud is ‘shifted’ downwards in the low noise setting. This would mean that the sampling distributions are shifted differently depending on the noise setting (sample size) when adding measurement error. On the other hand, when plotting the data in the same coordinate system, it is clear that the expected values do not change and that effect is driven by the differing variances of the estimator.
And one more thing: in the right panel in the figure of the paper the authors plot $\mathcal{P}^\uparrow$ as a function of $N$. Note that from the discussion in (4) it follows that this value can never be larger than $\frac{1}{2}$ as long as the estimator is unbiased or biased downwards. So there must have been some mistake.
Conclusion
This was a fun opportunity to do some statistics detective work. However, the lack of clarity does potentially also do quite some harm by confusing the reader about important concepts. There is of course also the possibility that I just fully misunderstood their paper. In that case I hope the reader will point to my mistakes.
The code to exactly reproduce the above figures can be found here.
I would like to thank Fabian Dablander and Peter Edelsbrunner for helpful comments on this blogpost. In addition, I would like to thank Oisín Ryan and Joris Broere for an interesting discussion on a train ride from Eindhoven to Utrecht yesterday, and I apologize to about 15 anonymous Dutch travelers because they had to endure a heated statistical debate.
I am looking forward to comments, complaints and corrections. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9742268323898315, "perplexity": 253.5222356544436}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-22/segments/1558232257781.73/warc/CC-MAIN-20190524224619-20190525010619-00377.warc.gz"} |
https://fykos.org/year26/problems/series2 | # 2. Series 26. Year
### (2 points)1. from Prague to Brno
Assume that the Earth is a sphere and the surface distance between Dresden and Vienna is approximately $d=370$ km. How much is the distance reduced if you decide to dig a tunnel between those two cities instead of walking. Neglect the different altitudes. Compare the tunnel distance with walking distance. For simplicity, you can approximate trigonometric functions as $$\mathrm{sin} α ≈ α - α^{3}/6 \,,\\ \mathrm{cos} α ≈ 1 - α^{2}/2 \,,\\ \mathrm{tg} α ≈ α + α^{3}/3 \,,$$ where the angle is assumed to be given in radians.
### (2 points)2. hollow Earth
Imagine that all the mass of the Earth is remodeled into a spherical shell. The thickness of the shell is $d=1\;\mathrm{km}$. Assume the density remains the same, what is the outer radius of the new planet? What is the gravitational acceleration on its surface?
### (4 points)3. life in Venice
Two chubby residents of Venice Paolo and Francesca Muschetti (with masses $m_{P}=180\;\mathrm{kg}$ and $m_{F}=130\;\mathrm{kg})$ decided to go for a gondola ride. However, none of the gondoliers would allow them to enter the boat because it would sink. Fortunately, they managed to find one gondolier who designed the device shown on the picture. Both Paolo and Francesca were tied to the ends of the rope in such a way that at first Francesca was at the top but then she switched with Paolo. How tall should this device be in order for the boat to traverse the canal? The travel time is $τ=60\;\mathrm{s}$. Assume that if this device is used, the gondola does not sink. You can neglect any friction, the mass of the rope and the moments of inertia of all the pulleys.
### (5 points)4. a hamster
Imagine the toy for hamsters depicted in the picture. The cylinder is free to rotate around the center point $O$. The hamster stands on the horizontal plate that is glued to the cylinder at a distance $h$ from the axis of rotation. How should the hamster move in order for the plate to stay in the horizontal position? The coefficient of friction between the hamster and the plate is $f$.
### (5 points)5. the U tube
Imagine a U-tube filled with mercury, and a bubble of height $h_{0}$ that floats inside (see the attached picture). Describe what would happen if we changed the surrounding atmosphere in the following ways. Assume that the density of mercury is independent of temperature. The same is valid for the glass the tube is made of. Also assume that the surrounding air behaves as an ideal gas. The initial state of the atmosphere is described by temperature $T_{0}=300K$, and pressure $p_{a}=10\cdot 10^{5}Pa$. Furthermore, assume that the system is in a thermodynamic equilibrium at all times, and that the bubble has a cylindrical shape.
• Both ends of the tube are open, and the temperature doubles.
• Both ends of the tube are closed, and the temperature doubles.
• Only one of the ends of the tube is closed, and the temperature doubles. For each of these cases, determine the new size of the bubble, and the height difference between the mercury columns in the two branches.
Bonus: Repeat the calculation assuming that the volume of mercury grows linearly with temperature.
### (5 points)P. messing with gravity
What if the gravitational constant suddenly doubled (without affecting the value of other physical constants)? What if it increased a hundred times? Discuss the impact the change would have on the life on the Earth and on the trajectories of bodies in the universe.
### (8 points)E. it's fall again
Estimate the average surface area of a leaf of your choice. We are looking forward to see a thorough statistical analysis of your measurements! Use your result to estimate the fraction of energy obtained from the Sun that is used to make saccharides.
### (6 points)S. drifting
• What kind of drifts can we observe in a linear trap? Assume that the axis of the trap is horizontal. Will the drift caused by the gravitational force have a significant effect on the motion of a particle?
• Derive a formula for the loss cone and draw an original picture illustrating the behavior of a particle in a linear trap.
• Derive a formula for the drift caused by an electric field that is perpendicular to a magnetic field and that has a constant gradient parallel with the electric field. Discuss the the dependence of the particle trajectories on the magnitude of this gradient. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8992549180984497, "perplexity": 433.69934213853514}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-35/segments/1566027315936.22/warc/CC-MAIN-20190821110541-20190821132541-00545.warc.gz"} |
https://www.zinkov.com/posts/2015-08-25-building-a-probabilisitic-interpreter/ | ## Building a probabilistic programming interpreter
##### 2015-08-25
Very often interpreters for probabilisitic programming languages (PPLs) can seem a little mysterious. In actuality, if you know how to write an interpreter for a simple language it isn’t that much more work.
Using Haskell as the host language I’ll show how to write a simple PPL which uses importance sampling as the underlying inference method. There is nothing special about using from haskell other than pattern-matching so this example should be pretty easy to port to other languages.
To start let’s import some things and set up some basic types
import Data.List hiding (empty, insert, map)
import Data.HashMap.Strict hiding (map)
import System.Random.MWC as MWC
import System.Random.MWC.Distributions as MD
type Name = String
type Env = HashMap String Val
Our language will have as values functions, doubles, bools and pairs of those.
data Val =
D Double |
B Bool |
F (Val -> Val) |
P Val Val
instance Eq Val where
D x == D y = x == y
B x == B y = x == y
P x1 x2 == P y1 y2 = x1 == y1 && x2 == y2
_ == _ = False
instance Ord Val where
D x <= D y = x <= y
B x <= B y = x <= y
P x1 x2 <= P y1 y2 = x1 <= y1 && x2 <= y2
_ <= _ = error "Comparing functions is undefined"
This language will have expressions for these values, conditionals and arithmetic.
data Expr =
Lit Double |
Var Name |
Pair Expr Expr |
Fst Expr |
Snd Expr |
If Expr Expr Expr |
Eql Expr Expr |
Les Expr Expr |
Gre Expr Expr |
And Expr Expr |
Lam Name Expr |
App Expr Expr |
Sub Expr Expr |
Mul Expr Expr |
Div Expr Expr
deriving (Eq, Show)
We can evalute expressions in this language without doing anything special.
evalT :: Expr -> Env -> Val
evalT (Lit a) _ = D a
evalT (Var x) env = env ! x
evalT (Lam x body) env = F (\ x' -> evalT body (insert x x' env))
evalT (App f x) env = app (evalT f env) (evalT x env)
evalT (Eql x y) env = B $(evalT x env) == (evalT y env) evalT (Les x y) env = B$ (evalT x env) <= (evalT y env)
evalT (Gre x y) env = B $(evalT x env) >= (evalT y env) evalT (And x y) env = liftB (&&) (evalT x env) (evalT y env) evalT (Add x y) env = liftOp (+) (evalT x env) (evalT y env) evalT (Sub x y) env = liftOp (-) (evalT x env) (evalT y env) evalT (Mul x y) env = liftOp (*) (evalT x env) (evalT y env) evalT (Div x y) env = liftOp (/) (evalT x env) (evalT y env) evalT (Pair x y) env = P (evalT x env) (evalT y env) evalT (Fst x) env = fst_$ evalT x env
where fst_ (P a b) = a
evalT (Snd x) env = snd_ \$ evalT x env
where snd_ (P a b) = b
evalT (If b t f) env = if_ (evalT b env) (evalT t env) (evalT f env)
where if_ (B True) t' f' = t'
if_ (B False) t' f' = f'
app :: Val -> Val -> Val
app (F f') x' = f' x'
liftOp :: (Double -> Double -> Double) ->
Val -> Val -> Val
liftOp op (D e1) (D e2) = D (op e1 e2)
liftB :: (Bool -> Bool -> Bool) ->
Val -> Val -> Val
liftB op (B e1) (B e2) = B (op e1 e2)
Of course this isn’t a probabilisitic programming language. So now we extend our language to include measures.
data Meas =
Uniform Expr Expr |
Weight Expr Expr |
Bind Name Meas Meas
deriving (Eq, Show)
Let’s take a moment to explain what makes something a measure. Measures can considered un-normalized probability distributions. If you take the sum of the probability of each disjoint outcome from a un-normalized probability distribution, the answer may not be 1.
This is relevant as we will be representing measures as a list of weighted draws from the underlying distribution. Those draws will need to be normalized to be understood as a probability distribution.
We can construct measures in one of three ways. We may simply have the continuous uniform distribution whose bounds are defined as expressions. We may have a weighted distribution which only returns the value of its second argument, with probability of the first argument. This is only a probability distribution when the first argument evaluates to one. We’ll call this case dirac
dirac :: Expr -> Meas
dirac x = Weight (Lit 1.0) x
The final form is what let’s us build measure expressions. What Bind does is take a measure as input, and a function from draws in that measure to another measure.
Because I don’t feel like defining measurable functions in their own form, Bind also takes a name to set what variable will hold values forthe draws, so the last argument to bind may just use that variable when it wants to refer to those draws. As an example if I wish to take a draw from a uniform distribution and then square that value.
prog1 = Bind "x" (Uniform (Lit 1) (Lit 5)) -- x <~ uniform(1, 5)
(dirac (Add (Var "x") (Var "x"))) -- return (x + x)
Measures are evaluated by producing a weighted sample from the measure space they represent. This is also called importance sampling.
evalM :: Meas -> Env -> MWC.GenIO -> IO (Val, Double)
evalM (Uniform lo hi) env g = do
let D lo' = evalT lo env
let D hi' = evalT hi env
x <- MWC.uniformR (lo', hi') g
return (D x, 1.0)
evalM (Weight i x) env g = do
let D i' = evalT i env
return (evalT x env, i')
evalM (Bind x m f) env g = do
(x', w) <- evalM m env g
let env' = insert x x' env
(f', w1) <- evalM f env' g
return (f', w*w1)
We may run these programs as follows
test1 :: IO ()
test1 = do
g <- MWC.create
draw <- evalM prog1 empty g
print draw
(7.926912543562406,1.0)
Evaluating this program repeatedly will allow you to produce as many draws from this measure as you need. This is great in that we can represent any unconditioned probability distribution. But how do we represent conditional distributions?
For that we will introduce another datatype
data Cond =
UCond Meas |
UniformC Expr Expr Expr |
WeightC Expr Expr Expr |
BindC Name Cond Cond
This is just an extension of Meas expect now we may say, a measure is either unconditioned, or if its conditioned for each case we may specify additionally which value its conditioned on. To draw from a conditioned measure, we convert it into an unconditional measure.
evalC :: Cond -> Meas
evalC (UCond m ) = m
evalC (UniformC lo hi x) = Weight (If (And (Gre x lo)
(Les x hi))
(Div x (Sub hi lo))
(Lit 0)) x
evalC (WeightC i x y) = Weight (If (Eql x y)
i
(Lit 0)) y
evalC (BindC x m f) = Bind x (evalC m) (evalC f)
What evalC does is determine what weight to assign to a measure given we know it will produce a particular value. This weight is the probability of getting this value from the measure.
And that’s all you need to express probabilisitic programs. Take the following example. Suppose we have two random variables x and y where the value of y depends on x
x <~ uniform(1, 5)
y <~ uniform(x, 7)
What’s the conditional distribution on x given y is 3?
prog2 = BindC "x" (UCond (Uniform (Lit 1) (Lit 5))) -- x <~ uniform(1, 5)
(BindC "_" (UniformC (Var "x") (Lit 7) (Lit 3)) -- y <~ uniform(x, 7)
-- observe y 3
(UCond (dirac (Var "x")))) -- return x
test2 :: IO ()
test2 = do
g <- MWC.create
samples <- replicateM 10 (evalM (evalC prog2) empty g)
print samples
[(1.099241451531848, 0.5084092113511076),
(3.963456271781203, 0.0),
(1.637454187135532, 0.5594357800735532),
(3.781075065891581, 0.0),
(1.908186342514358, 0.5891810269980327),
(2.799366130116895, 0.714177929552209),
(3.091757816253942, 0.0),
(1.486166046469419, 0.5440860253107659),
(3.106369061983323, 0.0),
(1.225163855492708, 0.5194952592470413)]
As you can see, anything above 3 for x has a weight of 0 because it would be impossible for to observe y with 3. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7183645367622375, "perplexity": 9161.527758834074}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882573849.97/warc/CC-MAIN-20220819222115-20220820012115-00711.warc.gz"} |
https://colleges.claremont.edu/ccms/event/alex-cloninger/ | « All Events
• This event has passed.
## Kernel approaches in global statistical distances, local measure detection, and active learning
### February 5 @ 4:15 pm - 5:15 pm
In this talk, we’ll discuss the problem of constructing meaningful distances between probability distributions given only finite samples from each distribution. We approach this through the use of data-adaptive and localized kernels, and in a variety of contexts. First, we construct locally adaptive kernels to define fast pairwise distances between distributions, with applications to unsupervised clustering. Then, we construct localized kernels to determine a statistical framework for determining where two distributions differ, with applications to measure detection for generative models. Finally, we’ll begin to address the question of measure detection without a priori known labels of which distribution a point came from. This is addressed through active learning, in which one can choose a small number of points at which to query a label. This is ongoing work with Xiuyuan Cheng (Duke) and Hrushikesh Mhaskar (CGU), among others.
## Details
Date:
February 5
Time:
4:15 pm - 5:15 pm
Event Category:
Blerta Shtylla
Helen Wong
## Venue
Freeberg Forum, LC 62, Kravis Center, CMC
## Details
Date:
February 5
Time:
4:15 pm - 5:15 pm
Event Category:
Blerta Shtylla
Helen Wong
## Venue
Freeberg Forum, LC 62, Kravis Center, CMC | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8726335763931274, "perplexity": 6650.283584998979}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-10/segments/1581875144027.33/warc/CC-MAIN-20200219030731-20200219060731-00303.warc.gz"} |
http://mathhelpforum.com/pre-calculus/223323-continued-fraction-expansion-help-proof.html | # Thread: continued fraction expansion help, / proof
1. ## continued fraction expansion help, / proof
I have attached the question I need help, question 5, and really not sure how to go about,
any help / tips appreciated
thank you
Attached Thumbnails
2. ## Re: continued fraction expansion help, / proof
Begin with writing out a little bit of the continued fraction:
$y = s + \cfrac{1}{s+ \cfrac{1}{s + \cfrac{1}{s+\cfrac{1}{\ddots}}}}$
Now, you are asked to show that $y = s+\dfrac{1}{y}$. This is obvious. Just replace everything under the top 1 of the continued fraction by y (since it is equal to y).
So, how can you solve the rest of it? Well, solve for $y$. If you multiply everything by $y$, you get $y^2 = sy+1$. Treat $s$ as a constant and you have a quadratic of one variable. Solve for $y$. Then $x = 1 + \dfrac{1}{y}$. Just plug in whatever you get as your answer.
3. ## Re: continued fraction expansion help, / proof
thank you, but do you mean replace the first top 1 by y = 1 + 1/y?
4. ## Re: continued fraction expansion help, / proof
Originally Posted by Tweety
thank you, but do you mean replace the first top 1 by y = 1 + 1/y?
Huh?
I mean
$y = s + \cfrac{1}{s+ \cfrac{1}{s + \cfrac{1}{s+\cfrac{1}{\ddots}}}} = s + \cfrac{1}{\left(s+ \cfrac{1}{s + \cfrac{1}{s+\cfrac{1}{\ddots}}}\right)}$
According to the first equality, the part that is in parentheses in the rightmost equation is equal to $y$. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 10, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9260869026184082, "perplexity": 671.1772825060934}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2016-50/segments/1480698541886.85/warc/CC-MAIN-20161202170901-00382-ip-10-31-129-80.ec2.internal.warc.gz"} |
http://mathhelpforum.com/calculus/85180-find-derivative-y-when.html | # Thread: Find derivative of y when....
1. ## Find derivative of y when....
http://i39.tinypic.com/nnqgk8.jpg
I got something close to the second choice but not exact.
Can you show how you got it?
2. Originally Posted by janedoe
http://i39.tinypic.com/nnqgk8.jpg
I got something close to the second choice but not exact.
Can you show how you got it?
$y=\sin\!\left(x+y\right)$
By implicit differentiation [and chain rule], we have $\frac{\,dy}{\,dx}=\cos\!\left(x+y\right)\cdot\left (1+\frac{\,dy}{\,dx}\right)\implies \frac{\,dy}{\,dx}=\cos\!\left(x+y\right)+\cos\!\le ft(x+y\right)\frac{\,dy}{\,dx}$
Can you finish off the problem? | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 2, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.6815862059593201, "perplexity": 1489.6175619668788}, "config": {"markdown_headings": true, "markdown_code": false, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2016-44/segments/1476988720967.29/warc/CC-MAIN-20161020183840-00125-ip-10-171-6-4.ec2.internal.warc.gz"} |
https://www.aimsciences.org/article/doi/10.3934/eect.2016002 | # American Institute of Mathematical Sciences
June 2016, 5(2): 225-234. doi: 10.3934/eect.2016002
## Blowup and ill-posedness results for a Dirac equation without gauge invariance
1 Dipartimento di Matematica, Unversità di Roma "La Sapienza", Piazzale A. More 2, 00185 Roma, Italy 2 Department of Mathematics, Institute of Engineering, Academic Assembly, Shinshu University, 4-17-1 Wakasato, Nagano City 380-8553
Received January 2016 Revised April 2016 Published June 2016
We consider the Cauchy problem for a nonlinear Dirac equation on $\mathbb{R}^{n}$, $n\ge1$, with a power type, non gauge invariant nonlinearity $\sim|u|^{p}$. We prove several ill-posedness and blowup results for both large and small $H^{s}$ data. In particular we prove that: for (essentially arbitrary) large data in $H^{\frac n2+}(\mathbb{R} ^n)$ the solution blows up in a finite time; for suitable large $H^{s}(\mathbb{R} ^n)$ data and $s< \frac{n}{2}-\frac{1}{p-1}$ no weak solution exist; when $1< p <1+\frac1n$ (or $1< p <1+\frac2n$ in $n=1,2,3$), there exist arbitrarily small initial data data for which the solution blows up in a finite time.
Citation: Piero D'Ancona, Mamoru Okamoto. Blowup and ill-posedness results for a Dirac equation without gauge invariance. Evolution Equations & Control Theory, 2016, 5 (2) : 225-234. doi: 10.3934/eect.2016002
##### References:
[1] I. Bejenaru and S. Herr, The cubic Dirac equation: Small initial data in $H^1(\mathbbR^3)$,, Comm. Math. Phys., 335 (2015), 43. doi: 10.1007/s00220-014-2164-0. Google Scholar [2] I. Bejenaru and S. Herr, The cubic Dirac equation: Small initial data in $H^{1/2}(\mathbbR^2)$,, Comm. Math. Phys., 343 (2016), 515. doi: 10.1007/s00220-015-2508-4. Google Scholar [3] N. Bournaveas and T. Candy, Global well-posedness for the massless cubic Dirac equation,, Int Math Res Notices in press., (). doi: 10.1093/imrn/rnv361. Google Scholar [4] T. Candy, Global existence for an $L^2$ critical nonlinear Dirac equation in one dimension,, Adv. Differential Equations, 16 (2011), 643. Google Scholar [5] T. Cazenave, Semilinear Schrödinger Equations,, Courant Lect. Notes Math., (2003). Google Scholar [6] M. Escobedo and L. Vega, A semilinear Dirac equation in $H^s(\mathbbR^3)$ for $s>1$,, SIAM J. Math. Anal., 28 (1997), 338. doi: 10.1137/S0036141095283017. Google Scholar [7] R. Glassey, Finite-time blow-up for solutions of nonlinear wave equations,, Math. Z., 177 (1981), 323. doi: 10.1007/BF01162066. Google Scholar [8] M. Ikeda and Y. Wakasugi, Small-data blow-up of $L^2$-solution for the nonlinear Schrödinger equation without gauge invariance,, Differential Integral Equations, 26 (2013), 1275. Google Scholar [9] M. Ikeda and T. Inui, Small data blow-up of $L^2$ or $H^1$-solution for the semilinear Schrödinger equation without gauge invariance,, J. Evol. Equ., 15 (2015), 571. doi: 10.1007/s00028-015-0273-7. Google Scholar [10] M. Ikeda and T. Inui, Some non-existence results for the semilinear Schrödinger equation without gauge invariance,, J. Math. Anal. Appl., 425 (2015), 758. doi: 10.1016/j.jmaa.2015.01.003. Google Scholar [11] F. John, Blow-up of solutions of nonlinear wave equations in three space dimensions,, Manuscripta Math., 28 (1979), 235. doi: 10.1007/BF01647974. Google Scholar [12] S. Machihara, M. Nakamura, K. Nakanishi and T. Ozawa, Endpoint Strichartz estimates and global solutions for the nonlinear Dirac equation,, J. Funct. Anal., 219 (2005), 1. doi: 10.1016/j.jfa.2004.07.005. Google Scholar [13] T. Oh, A blowup result for the periodic NLS without gauge invariance,, C. R. Acad. Sci. Paris. Ser., 350 (2012), 389. doi: 10.1016/j.crma.2012.04.009. Google Scholar [14] H. Pecher, Local well-posedness for the nonlinear Dirac equation in two space dimensions,, Commun. Pure Appl. Anal., 13 (2014), 673. doi: 10.3934/cpaa.2014.13.673. Google Scholar [15] T. Runst and W. Sickel, Sobolev Spaces of Fractional Order, Nemytskij Operators, and Nonlinear Partial Differential Equations,, de Gruyter Series in Nonlinear Analysis and Applications, 3 (1996). doi: 10.1515/9783110812411. Google Scholar [16] T. Sideris, Nonexistence of global solutions to semilinear wave equations in high dimensions,, J. Differential Equations, 52 (1984), 378. doi: 10.1016/0022-0396(84)90169-4. Google Scholar [17] Q. Zhang, Blow-up results for nonlinear parabolic equations on manifolds,, Duke Math. J., 97 (1999), 515. doi: 10.1215/S0012-7094-99-09719-3. Google Scholar [18] Q. Zhang, A blow-up result for a nonlinear wave equation with damping: The critical case,, C. R. Acad. Sci. Paris, 333 (2001), 109. doi: 10.1016/S0764-4442(01)01999-1. Google Scholar
show all references
##### References:
[1] I. Bejenaru and S. Herr, The cubic Dirac equation: Small initial data in $H^1(\mathbbR^3)$,, Comm. Math. Phys., 335 (2015), 43. doi: 10.1007/s00220-014-2164-0. Google Scholar [2] I. Bejenaru and S. Herr, The cubic Dirac equation: Small initial data in $H^{1/2}(\mathbbR^2)$,, Comm. Math. Phys., 343 (2016), 515. doi: 10.1007/s00220-015-2508-4. Google Scholar [3] N. Bournaveas and T. Candy, Global well-posedness for the massless cubic Dirac equation,, Int Math Res Notices in press., (). doi: 10.1093/imrn/rnv361. Google Scholar [4] T. Candy, Global existence for an $L^2$ critical nonlinear Dirac equation in one dimension,, Adv. Differential Equations, 16 (2011), 643. Google Scholar [5] T. Cazenave, Semilinear Schrödinger Equations,, Courant Lect. Notes Math., (2003). Google Scholar [6] M. Escobedo and L. Vega, A semilinear Dirac equation in $H^s(\mathbbR^3)$ for $s>1$,, SIAM J. Math. Anal., 28 (1997), 338. doi: 10.1137/S0036141095283017. Google Scholar [7] R. Glassey, Finite-time blow-up for solutions of nonlinear wave equations,, Math. Z., 177 (1981), 323. doi: 10.1007/BF01162066. Google Scholar [8] M. Ikeda and Y. Wakasugi, Small-data blow-up of $L^2$-solution for the nonlinear Schrödinger equation without gauge invariance,, Differential Integral Equations, 26 (2013), 1275. Google Scholar [9] M. Ikeda and T. Inui, Small data blow-up of $L^2$ or $H^1$-solution for the semilinear Schrödinger equation without gauge invariance,, J. Evol. Equ., 15 (2015), 571. doi: 10.1007/s00028-015-0273-7. Google Scholar [10] M. Ikeda and T. Inui, Some non-existence results for the semilinear Schrödinger equation without gauge invariance,, J. Math. Anal. Appl., 425 (2015), 758. doi: 10.1016/j.jmaa.2015.01.003. Google Scholar [11] F. John, Blow-up of solutions of nonlinear wave equations in three space dimensions,, Manuscripta Math., 28 (1979), 235. doi: 10.1007/BF01647974. Google Scholar [12] S. Machihara, M. Nakamura, K. Nakanishi and T. Ozawa, Endpoint Strichartz estimates and global solutions for the nonlinear Dirac equation,, J. Funct. Anal., 219 (2005), 1. doi: 10.1016/j.jfa.2004.07.005. Google Scholar [13] T. Oh, A blowup result for the periodic NLS without gauge invariance,, C. R. Acad. Sci. Paris. Ser., 350 (2012), 389. doi: 10.1016/j.crma.2012.04.009. Google Scholar [14] H. Pecher, Local well-posedness for the nonlinear Dirac equation in two space dimensions,, Commun. Pure Appl. Anal., 13 (2014), 673. doi: 10.3934/cpaa.2014.13.673. Google Scholar [15] T. Runst and W. Sickel, Sobolev Spaces of Fractional Order, Nemytskij Operators, and Nonlinear Partial Differential Equations,, de Gruyter Series in Nonlinear Analysis and Applications, 3 (1996). doi: 10.1515/9783110812411. Google Scholar [16] T. Sideris, Nonexistence of global solutions to semilinear wave equations in high dimensions,, J. Differential Equations, 52 (1984), 378. doi: 10.1016/0022-0396(84)90169-4. Google Scholar [17] Q. Zhang, Blow-up results for nonlinear parabolic equations on manifolds,, Duke Math. J., 97 (1999), 515. doi: 10.1215/S0012-7094-99-09719-3. Google Scholar [18] Q. Zhang, A blow-up result for a nonlinear wave equation with damping: The critical case,, C. R. Acad. Sci. Paris, 333 (2001), 109. doi: 10.1016/S0764-4442(01)01999-1. Google Scholar
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http://math.stackexchange.com/questions/183337/are-monomorphisms-of-rings-injective | # Are monomorphisms of rings injective?
Let $R$ and $S$ be rings and $f:R\to S$ a monomorphism. Is $f$ injective?
-
Next exercise: show that there is an epic ring homomorphism that is not surjective. – rschwieb Aug 16 '12 at 19:17
Yes, $f$ is injective:
Let's assume the map of the underlying sets is NOT injective. Then there are distinct $x,y\in R$ such that $f(x)=f(y)$.
Next, consider the monomorphisms $g_1,g_2\colon \mathbf{Z}[X]\to R$ by $g_1(X)=x$ and $g_2(X)=y$. Note that these monomorphisms are different and $f\circ g_1= f\circ g_2$. This implies $f$ is NOT a monomorphism, which leads to a contradiction.
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Yes. Suppose $f$ is a monomorphism which is not injective, ie $f(a)=f(b)$. Now consider $g_1:\mathbb{Z}[x]\to R$ given by sending $x\mapsto a$ and $g_2:\mathbb{Z}[x]\to R$ given by $x\mapsto b$. Then $f\circ g_1=f\circ g_2$ despite the two maps being different. Thus monomorphisms must be injective.
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Assume that there is a monomorphism of rings $\varphi:A\longrightarrow B$ which is not injective, i.e. there are $a_1\neq a_2$ s.t. $\varphi(a_1)= \varphi(a_2)$.
Now if you consider the maps $g_1$ and $g_2:\mathbb{Z}[X]\longrightarrow A$ defined by $g_i(X)=a_i$, you can check that $\varphi\circ g_1=\varphi\circ g_2$, but $g_1\neq g_2$...
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http://mathhelpforum.com/calculus/78435-continuous-function.html | # Math Help - Continuous Function
1. ## Continuous Function
for which value of the constant $K$ is the function $h(x)=\left\{\begin{array}{cc}\frac{e^x -e^a}{x-a},&\mbox{ if }
x\ne a\\K, & \mbox{ if } x=a\end{array}\right.$
continuous at $x=a$. justify your answer.
$\lim_{x \rightarrow a} h(x) = \lim_{x \rightarrow a} \frac{e^x - e^a}{x-a}$
$h(a) = K$ and the other limit is $e^a \log(e)$
so is $K = e^a \log(e)$?, is this a correct way of answering the question
2. Originally Posted by iLikeMaths
for which value of the constant $K$ is the function $h(x)=\left\{\begin{array}{cc}\frac{e^x -e^a}{x-a},&\mbox{ if }
x\ne a\\K, & \mbox{ if } x=a\end{array}\right.$
continuous at $x=a$. justify your answer.
$\lim_{x \rightarrow a} h(x) = \lim_{x \rightarrow a} \frac{e^x - e^a}{x-a}$
$h(a) = K$ and the other limit is $e^a \log(e)$
so is $K = e^a \log(e)$?, is this a correct way of answering the question
yes, but log should be natural log, and also $\ln(e)=1$.
3. so $K =e^a$ thanks | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 16, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9927327036857605, "perplexity": 711.6764218275126}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 5, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-23/segments/1405997900573.25/warc/CC-MAIN-20140722025820-00219-ip-10-33-131-23.ec2.internal.warc.gz"} |
https://hal.inria.fr/hal-01661004 | # Distributed Universal Constructions: a Guided Tour
1 ASAP - As Scalable As Possible: foundations of large scale dynamic distributed systems
Inria Rennes – Bretagne Atlantique , IRISA_D1 - SYSTÈMES LARGE ÉCHELLE
Abstract : The notion of a universal construction is central in computing science: the wheel has not to be reinvented for each new problem. In the context of n-process asynchronous distributed systems, a universal construction is an algorithm that is able to build any object defined by a sequential specification despite the occurrence of up to (n − 1) process crash failures. The aim of this paper is to present a guided tour of such universal constructions. Its spirit is not to be a catalog of the numerous constructions proposed so far, but a (as simple as possible) presentation of the basic concepts and mechanisms that constitute the basis these constructions rest on.
Type de document :
Article dans une revue
Bulletin of the EATCS, EATCS, 2017, 121, pp.1-34
Domaine :
https://hal.inria.fr/hal-01661004
Contributeur : Davide Frey <>
Soumis le : lundi 11 décembre 2017 - 15:50:53
Dernière modification le : jeudi 7 février 2019 - 16:15:19
### Identifiants
• HAL Id : hal-01661004, version 1
### Citation
Michel Raynal. Distributed Universal Constructions: a Guided Tour. Bulletin of the EATCS, EATCS, 2017, 121, pp.1-34. 〈hal-01661004〉
### Métriques
Consultations de la notice | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8978331089019775, "perplexity": 4835.897890901082}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-09/segments/1550247488490.40/warc/CC-MAIN-20190218220415-20190219002415-00557.warc.gz"} |
http://math.stackexchange.com/questions/102577/how-do-i-differentiate-this-function | # How do I differentiate this function?
How do I differentiate $y(t)=-[t]+\frac{1}{2}\cdot(1-3^{t-[t]})$, $t \ge 0$, ($[x]$ is the integer part of $x$) in order to verify that it is the solution of the ODE $y' = \log(3) \cdot (y-[y]-\frac{3}{2})$, $y(0)=0$?
-
The same way you differentiate any other expression.
\begin{align} \frac{dy(t)}{dt} &= -\frac{d[t]}{dt} + \frac12\frac{d}{dt}\left(1 - 3^{t-[t]}\right) \\ &= -\frac{d[t]}{dt} + \frac12 \left(0 - 3^{t-[t]} \log 3 \cdot \frac{d}{dt}(t-[t])\right) \\ &= -\frac{d[t]}{dt} - \frac12 3^{t-[t]}\log 3\cdot\left(1 - \frac{d[t]}{dt}\right). \end{align}
When $t$ is an integer, $[t]$ has a discontinuity and its derivative is undefined. So, for the differentiation to make sense, we can only consider the case when $t$ is not an integer. Then, $[t]$ is locally constant, so $d[t]/dt = 0$, and we have \begin{align} \frac{dy(t)}{dt} &= -0 - \frac12 3^{t-[t]}\log 3\cdot\left(1 - 0\right) \\ &= -\frac123^{t-[t]}\log 3. \end{align}
Edit: Okay, let's see if we can plug this into the ODE and verify the solution. We have $$y(t) = -[t] + \frac12\left(1 - 3^{t-[t]}\right),$$ and we want to know what $\log3\cdot\left(y - [y] - \frac32\right)$ is, so we should figure out something about $y - [y]$. Knowing that $t - [t]$ lies between $0$ and $1$, it is straightforward to find that $\frac12\left(1 - 3^{t-[t]}\right)$ lies between $-1$ and $0$. So $y(t)$ is a little lower than $-[t]$, but not so low that it passes $-[t]-1$. Since $-[t]$ is an integer, that tells you exactly what $[y(t)]$ is. Plug that in and I expect you should arrive at the solution pretty quickly.
-
The function $y(t)$ is actually continuous everywhere. It's precisely this that makes it a valid solution to the ODE. (The derivative is not continuous at integer arguments, but we already knew this from the RHS of the ODE.) – TonyK Jan 26 '12 at 13:21
Thank you Rahul and TonyK. But how would I simplify y-[y] ? I still can't see y, as given, is the solution of the ODE. This: [x+y]=[x]+[y],however, is wrong. – yuanwei Jan 26 '12 at 13:51
@yuanwei, please see my edit. – Rahul Jan 26 '12 at 14:40
Let's denote $[t]$ as : $[t]=trunc(t)$
According to Maple solution exists only for real numbers that are not non-zero integers and it is given by following expression :
$y'(t)=-trunc(1,t)-\frac{1}{2}\cdot 3^{t-trunc(t)}\cdot (1-trunc(1,t))\cdot \ln 3$
- | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 2, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9997871518135071, "perplexity": 269.8482831101006}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-48/segments/1448398453656.76/warc/CC-MAIN-20151124205413-00165-ip-10-71-132-137.ec2.internal.warc.gz"} |
https://www.rdocumentation.org/packages/rms/versions/2.0-2/topics/rms.trans | # rms.trans
From rms v2.0-2
0th
Percentile
##### rms Special Transformation Functions
This is a series of functions (asis, pol, lsp, rcs, catg, scored, strat, matrx, and %ia%) that set up special attributes (such as knots and nonlinear term indicators) that are carried through to fits (using for example lrm,cph, ols, psm). anova.rms, summary.rms, Predict, survplot, fastbw, validate, specs, which.influence, nomogram and latex.rms use these attributes to automate certain analyses (e.g., automatic tests of linearity for each predictor are done by anova.rms). Many of the functions are called implicitly. Some S functions such as ns derive data-dependent transformations that are not "remembered" when predicted values are later computed, so the predictions will be incorrect. The functions listed here solve that problem.
asis is the identity transformation, pol is an ordinary (non-orthogonal) polynomial, rcs is a linear tail-restricted cubic spline function (natural spline, for which the rcspline.eval function generates the design matrix and the presence of system option rcspc causes rcspline.eval to be invoked with pc=TRUE), catg is for a categorical variable, scored is for an ordered categorical variable, strat is for a stratification factor in a Cox model, matrx is for a matrix predictor, and %ia% represents restricted interactions in which products involving nonlinear effects on both variables are not included in the model. asis, catg, scored, matrx are seldom invoked explicitly by the user (only to specify label or name, usually).
In the list below, functions asis through strat can have arguments x, parms, label, name except that parms does not apply to asis, matrx, strat.
Keywords
manip, models, methods, regression, smooth, math, survival
##### Usage
asis(x, parms, label, name)
matrx(x, label, name)
pol(x, parms, label, name)
lsp(x, parms, label, name)
rcs(x, parms, label, name)
catg(x, parms, label, name)
scored(x, parms, label, name)
strat(x, label, name)
x1 %ia% x2
##### Arguments
x
a predictor variable (or a function of one). If you specify e.g. pol(pmin(age,10),3), a cubic polynomial will be fitted in pmin(age,10) (pmin is the S vector element--by--element function). The predictor will be lab
parms
parameters of transformation (e.g. number or location of knots). For pol the argument is the order of the polynomial, e.g. 2 for quadratic (the usual default). For lsp it is a vector of knot locations (lsp
label
label of predictor for plotting (default = "label" attribute or variable name)
name
Name to use for predictor in model. Default is name of argument to function
x1
x2
two continuous variables for which to form a non-doubly-nonlinear interaction
...
a variety of things
##### synopsis
asis(...) matrx(...) pol(...) lsp(...) rcs(...) catg(...) scored(...) strat(...) %ia%(x1, x2)
##### concept
• logistic regression model
• transformation
rcspline.eval, rcspline.restate, rms, cph, lrm, ols, datadist
• rms.trans
• asis
• pol
• lsp
• rcs
• catg
• scored
• strat
• matrx
• %ia%
##### Examples
options(knots=4, poly.degree=2)
country <- factor(country.codes)
blood.pressure <- cbind(sbp=systolic.bp, dbp=diastolic.bp)
fit <- lrm(Y ~ sqrt(x1)*rcs(x2) + rcs(x3,c(5,10,15)) +
lsp(x4,c(10,20)) + country + blood.pressure + poly(age,2))
# sqrt(x1) is an implicit asis variable, but limits of x1, not sqrt(x1)
# are used for later plotting and effect estimation
# x2 fitted with restricted cubic spline with 4 default knots
# x3 fitted with r.c.s. with 3 specified knots
# x4 fitted with linear spline with 2 specified knots
# country is an implied catg variable
# blood.pressure is an implied matrx variable
# since poly is not an rms function (pol is), it creates a
# matrx type variable with no automatic linearity testing
# or plotting
f1 <- lrm(y ~ rcs(x1) + rcs(x2) + rcs(x1) %ia% rcs(x2))
# %ia% restricts interactions. Here it removes terms nonlinear in
# both x1 and x2
f2 <- lrm(y ~ rcs(x1) + rcs(x2) + x1 %ia% rcs(x2))
# interaction linear in x1
f3 <- lrm(y ~ rcs(x1) + rcs(x2) + x1 %ia% x2)
# simple product interaction (doubly linear)
# Use x1 %ia% x2 instead of x1:x2 because x1 %ia% x2 triggers
# anova to pool x1*x2 term into x1 terms to test total effect
# of x1
Documentation reproduced from package rms, version 2.0-2, License: GPL (>= 2)
### Community examples
Looks like there are no examples yet. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.47214674949645996, "perplexity": 29398.545255731384}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-16/segments/1585370500331.13/warc/CC-MAIN-20200331053639-20200331083639-00338.warc.gz"} |
https://www.physicsforums.com/threads/light-clock-with-problems.865024/ | # B Light clock with problems
1. Apr 2, 2016
### DAC
Hello P.F.
I have previously raised the idea of a light clock that ticked each time the light travelled one metre. Dale has said if I could explain how it could be done, I could open a new thread. Here goes.
A normal light clock ticks each time the light goes mirror to mirror.
I propose a light clock that ticks each time the light goes one metre.With the mirrors one metre apart in the stationary frame, the two are the same.
What happens when the train is moving?
The mirrors will still be one metre apart in both frames.
The diagonal light path will still be the same diagonal light path.
The sensors locations however have to change. Remove the existing sensors and replace with sensors at one metre intervals along the light's path.
So if the perpendicular path is one metre, the clock ticks once. If the diagonal path is two metres the clock ticks twice. Both clocks tick at the same rate, once per metre, irrespective of the light paths length.
This conflicts with S.R. can you explain.
Thanks.
2. Apr 2, 2016
### PeroK
There is no common definition of travelling one metre. The light will have travelled one metre in the ground frame when it is still short of the mirror.
And, of course, this is true in classical physics too. If someone on the train throws a ball up 1m, then someone on the ground sees that ball travel more than 1m up and across. Your confusion is not acually with light clocks and Special Relativity. Your confusion is actually in grasping the concept of two reference frames and basic trigonometry.
3. Apr 2, 2016
### Ibix
If the sensors are at rest in the train frame then you only need two of them - one at each mirror. If the sensors are not at rest in the train frame you need infinitely many of them, at various points at different heights along the zigzag path of the light (because in a frame moving at v with respect to the train the path length of the light on one leg is $\sqrt {1+v/\sqrt {c^2-v^2}}$, if my mental algebra is correct, which is not 1m in general).
Which setup were you meaning?
To me, it still looks as if you are failing to recognise that the distance travelled to get from one end of a moving object to the other is not the same as its length. Until you grasp this fact (true in Galilean relativity as well as Einsteinian relativity) you will continue to fail to understand relativity.
4. Apr 2, 2016
### Orodruin
Staff Emeritus
PeroK's and Ibix's replies are sound. Your problem seems to be in grasping that the same physical situation must be described by all frames without changing the basic setup. You cannot have the sensors located at the mirrors in one frame and at different places in another.
I stand by the suggestion that you should probably spend a significant amount of time to study Galilean relativity before trying to deal with special relativity.
From your posts, it is clear that you do not have a grasp of the subject equivalent to that of a graduate student in physics. I have therefore relabeled the thread accordingly.
5. Apr 2, 2016
### DAC
One
When the sensors are not at rest applies to the standard light clock as well. The sensors move with the clock/train. Yes, one metre will fall at different points along the diagonal path
6. Apr 2, 2016
### Orodruin
Staff Emeritus
But the key point is that you are then not describing the same physical situation. If you place the sensors at the mirrors, they will be at the mirrors in all frames. This is not something you can change from frame to frame.
7. Apr 2, 2016
### DAC
The sensors are placed at the same interval, one metre apart. Why is that less valid than sensors every mirror to mirror apart? I have not changed the basic set up of the stationary frame, I have adhered to it.
8. Apr 2, 2016
### DAC
The clock ticks each time light goes one metre. This is the same in both frames. I have changed nothing.
9. Apr 2, 2016
### Orodruin
Staff Emeritus
No it is not, you are describing different clocks. One where the sensors are at the mirrors and one where they are not. It just so happens that you have constructed them in such a way that they tick at the same rate when one of them is moving. This does not violate SR as much as it demonstrates a fundamental misunderstanding of relativity (Galilean and special). Before you address this misunderstanding, you are in no position to make claims about inconsistencies.
As suggested by other posters, you first need to remedy your misconceptions before trying to implement your thoughts, or you will end up in the wrong place.
10. Apr 2, 2016
### Samy_A
@DAC: It's a pet peeve of me, but I would suggest you use a little more numbers and a little less words to describe the situation. That will (hopefully) help clear up what you misunderstand about the situation.
11. Apr 2, 2016
### DAC
In the stationary frame with the mirrors one metre apart, the clock ticks every one metre travelled. And in the moving frame it also ticks every one metre travelled. There is no difference between frames.
12. Apr 2, 2016
### Orodruin
Staff Emeritus
Yes there is! It is not the same clock! You have simply constructed two different clocks based on an underlying principle in two different frames. Due to time dilation, applying this construction to the moving clock will result in a clock which is physically different from one which is constructed at rest - as evidenced by the fact that one clock has its sensors at the mirrors and the other does not.
13. Apr 2, 2016
### Staff: Mentor
You have not explained how you would build such a clock, you have only again asserted your wishful assumption that such a clock were possible. I gave you an example of how you could specify the design of a clock which could be analyzed. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5516238808631897, "perplexity": 608.8114825895427}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-30/segments/1531676592861.86/warc/CC-MAIN-20180721223206-20180722003206-00475.warc.gz"} |
http://www.billthelizard.com/2011/04/sicp-238-239-folding-left-and-right.html | ## Saturday, April 30, 2011
### SICP 2.38 & 2.39: Folding Left and Right
From SICP section 2.2.3 Sequences as Conventional Interfaces
Exercise 2.38 informs us that another name for the accumulate procedure we've been using is fold-right, because it combines the elements of a sequence starting on the left and moving to the right. There's also a fold-left procedure that combines elements working in the opposite direction.
; fold-right is another name for accumulate(define (fold-right op initial sequence) (if (null? sequence) initial (op (car sequence) (fold-right op initial (cdr sequence))))); fold-left is given in exercise 2.38(define (fold-left op initial sequence) (define (iter result rest) (if (null? rest) result (iter (op result (car rest)) (cdr rest)))) (iter initial sequence))
We're given a few expressions that illustrate how these two procedures behave differently.
> (fold-right / 1 (list 1 2 3))1 1/2> (fold-left / 1 (list 1 2 3))1/6> (fold-right list null (list 1 2 3))(1 (2 (3 ())))> (fold-left list null (list 1 2 3))(((() 1) 2) 3)
We're asked what property the op parameter needs to satisfy to guarantee that fold-right and fold-left will produce the same values for any sequence.
The property that will guarantee that fold-right and fold-left will produce the same values for any sequence is commutativity. You may remember the commutative property of both addition and multiplication from algebra. It's the law that says that:
A + B = B + A
and
A x B = B x A
Subtraction and division are not commutative operations. The AND and OR operations in Boolean algebra are commutative.
Exercise 2.39 asks us to complete the following definitions of reverse (from exercise 2.18) in terms of fold-right and fold-left:
(define (reverse sequence) (fold-right (lambda (x y) <??>) null sequence))(define (reverse sequence) (fold-left (lambda (x y) <??>) null sequence))
Since we only need to define the operator used in each implementation, the key to this exercise lies in how the operator is applied in each folding procedure. Pay close attention to the order of the arguments of the op procedure.
In fold-right the operator is applied to the car of the sequence and the result of a recursive call to fold-right. Just as we did in exercise 2.18, we can reverse the sequence using fold-right by appending the car of the sequence to the reverse of its cdr.
(define (reverse sequence) (fold-right (lambda (x y) (append y (list x))) null sequence))
In fold-left the operator is applied to the result sequence and the car of the unused elements in the initial sequence. Since the result sequence starts with an initial value of null, and we're starting at the end of the sequence and working backwards anyway, we can just cons each element to the end of the result.
(define (reverse sequence) (fold-left (lambda (x y) (cons y x)) null sequence))
As expected, we get the same test results for either of the two reverse implementations above.
> (reverse (list 1 2 3 4))(4 3 2 1)> (reverse (list 1 4 9 16 25))(25 16 9 4 1)> (reverse (list 1 3 5 7))(7 5 3 1)> (reverse (list 23 72 149 34))(34 149 72 23)
Related:
For links to all of the SICP lecture notes and exercises that I've done so far, see The SICP Challenge.
Tim Kington said...
I found the earlier accumulate examples very tough going. I find fold-left much more intuitive, and kept being surprised that accumulate didn't work that way.
Bill the Lizard said...
Tim,
Do you mean the implementation or this exercise was more intuitive? I find the implementation of fold-right a bit easier to grasp, but the way fold-left works definitely made the solution to this particular exercise simpler.
Alex Marandon said...
A note for those of us testing their code with Racket. The foldl function of Racket doesn't behave the same way as what is described in SICP. There's a discussion about this on SO [1]. Make sure you use the implementations of fold-left presented in the book otherwise you'll get different results. If you load neil/sicp [2] you won't have Racket's foldl and foldr available but if you do exercise 2.38 without loading it (as I initially did) and try to use foldl from Racket, you might get confused.
[1] http://stackoverflow.com/questions/8778492/why-is-foldl-defined-in-a-strange-way-in-racket
[2] http://planet.plt-scheme.org/package-source/neil/sicp.plt/1/16/planet-docs/sicp/index.html
Bill the Lizard said...
Thanks Alex. I only upgraded to Racket about a month ago, so I don't know the inconsistencies between its implementations and the earlier exercises. Thanks for pointing that out.
Anonymous said...
Hi Bill,
The algebraic property you're after is not commutativity -- it's associativity. (I.e. need (op A (op B C)) to yield the same value as (op (op A B) C)
Managed to find the link below to save me typing up some long winded explanation. He uses the example of matrix multiplication, which is associative but obviously not commutative.
http://danboykis.com/2009/08/exercise-2-38-of-sicp/
- 12qu
12qu said...
EDIT: On further reflection, I think we need both associativity and commutativity.
When we go from fold-left to fold-right, we effectively pull the init value from the far left hand side of the expression to the far right. The only way to guarantee that fold-left will equal fold-right in this case is if (op a b) always gives (op b a) (i.e. it commutes).
In the matrix multiplication example, for instance, if some matrix other than the identity matrix is used for init, then fold-left won't in general give fold-right, as is quite easy to verify.
Likewise, to see that commutativity is not enough, consider the function (define (average x y) (* .5 (+ x y))), which is commutative and not associative, and for which fold-left does not, in general, equal fold right.
Bill the Lizard said...
12qu,
I think you might be right, it might be both associativity and commutativity. I did some searching around, and there are a lot of sites that say one or the other. To prove that it is both, we'd have to find an operation that works that is associative and not commutative. I'll give it some thought before updating the post.
Thanks!
Wei Xue said...
Yes. Both commutativity and associativity
Anonymous said...
No, only associativity.
Consider this operation:
(define (foo a b) (fringe (list a b)))
This operation takes two things, creates a list of them and then flattens the list.
It is associative, because if a = (list a1 a2 ...) and b = (list b1 b2 ...) and c = (list c1 c2 ...) then:
(foo (foo a b) c) = (list a1 a2 ... b1 b2 ... c1 c2) = (foo a (foo b c))
It isn't commutative:
(foo 1 2) = (list 1 2)
(foo 2 1) = (list 2 1)
Now:
> (fold-right foo nil (list 1 2 3 4))
(1 2 3 4)
> (fold-left foo nil (list 1 2 3 4))
(1 2 3 4)
Anonymous said...
Oops, never mind, I was wrong since when the default value is not nil then the results are different. So both associative and commutative. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.6824727654457092, "perplexity": 2519.993204636646}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-51/segments/1544376823712.21/warc/CC-MAIN-20181212022517-20181212044017-00438.warc.gz"} |
https://www.cowhampshireblog.com/tag/dane/ | # Tag Archives: Dane
## A Nurse Hero of WWI: Elma Irene Groves of Lodi Wisconsin (1888-1918)
As my readers know, I rarely write about people who do not have a New Hampshire connection. In this particular case the 2nd great-niece of a nurse who died in service during WWI contacted me, and I agreed to write … Continue reading
Posted in History, Lost Faces of WW1 | Tagged , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , | 8 Comments
## New Hampshire Missing Places: The Whittier Pine of Center Harbor
It had been called the Whittier Pine. The famed poet John Greenleaf Whittier had his own personal name for this great tree–Wood Giant. It was located on land near the Sturtevant Farm on Route 25B/Dane Road, Center Harbor NH. [Editor’s … Continue reading | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8068138957023621, "perplexity": 5063.085095022886}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2023-14/segments/1679296950528.96/warc/CC-MAIN-20230402105054-20230402135054-00115.warc.gz"} |
http://mathhelpforum.com/calculus/117933-power-series-question-print.html | # Power Series Question
• December 1st 2009, 09:45 PM
bambamm
Power Series Question
A function f is defined by
f(x) = 2 + 3x + 2x2 + 3x3 + 2x4 + ...
that is, its coefficients are c2n = 2 and c2n+1 = 3 for all n=>0.
a.) Find the interval of convergence of the series
b.) Find an explicit formula for f(x).
I don't have the slightest clue how to do this problem as the representation of the series is confusing. Could somebody be to kind as to assist me on this. Thank you very much!
• December 1st 2009, 10:01 PM
qmech
Rewrite the function
$
f(x) = 2 + 3x + 2x^2 + 3x^3 + 2x^4...
$
$
f(x) = 2 + 2x + 2x^2 + 2x^3 + 2x^4...
+ x + x^3 + x^5 + ...
$
$
f(x) = 2(1 + x + x^2 + x^3 + x^4...)
+ (x + x^3 + x^5 + ...)
$
$
f(x) = 2g(x)+ h(x)
$
where
$
g(x) = 1 + x + x^2 + x^3 + x^4...
$
$h(x)= x + x^3 + x^5 + ...$
Look familiar? | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 6, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9176822304725647, "perplexity": 679.6265817781798}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2016-36/segments/1471982931818.60/warc/CC-MAIN-20160823200851-00226-ip-10-153-172-175.ec2.internal.warc.gz"} |
https://chem.libretexts.org/Courses/BridgeValley_Community_and_Technical_College/Fundamentals_of_Chemistry/11%3A_Organic_Chemistry/11.03%3A_Branched_Alkanes | # 11.3: Branched Alkanes
Tracing your family tree can be both fun and exciting. In order to do this correctly, it helps to know the exact names of your family members. Just a first, middle, or last name is not enough. A traceable family tree is one in which all relatives are carefully and precisely identified. After all, you would prefer that great-great-great-uncle to be royalty, and not a horse thief!
## Branched Alkanes
Beginning with butane, there is an alternate structure possible that is not a straight chain. The structural formula below shows a structure with a three-carbon chain that has a $$\ce{-CH_3}$$ group attached to the middle carbon.
The name of this molecule is 2-methylpropane. The molecular formula is still $$\ce{C_4H_{10}}$$, which is the same formula as butane. A structural isomer is one of multiple molecules that have the same molecular formula, but different structural formulas. Butane and 2-methylpropane are structural isomers.
2-methylpropane is an example of a type of alkane called a branched alkane. The IUPAC system of nomenclature for branched alkanes follows a set of steps which will be applied to the example molecule below.
1. Find the longest continuous chain of carbon atoms in the molecule. This is called the parent chain. In the example, the longest chain is eight carbon atoms, and so the parent hydrocarbon is octane.
2. Number the carbon atoms in the parent chain. To do this, start at the end that will give the smallest numbers possible to the carbon atoms where the branches originate. In the example above, the branches are on carbons 3 and 5 when the chain is numbered left-to-right. If it were to be numbered right-to-left, the branches would be on carbons 4 and 6, so the left-to-right order is preferable.
3. The atoms attached to the parent chain (branches) are called substituents. A substituent that is a hydrocarbon is called an alkyl group. The names of alkyl groups use the same prefixes as the alkanes, but with a -yl suffix. So a 1-carbon alkyl group is a methyl group, a 2-carbon alkyl group is an ethyl group, and so on. The substituents are named by placing the number from the parent carbon chain in front of the name of the substituent. In the current example, we have 3-methyl and 4-ethyl substituents.
4. Use a prefix to indicate the appearance of more than one of the same substituent in the structural formula. Two of the same group is di-, three is tri-, four is tetra-, etc. For example, if methyl groups were attached to both carbons 2 and 3, that part of the name would be 2,3-dimethyl-. This rule does not apply to the structure pictured above.
5. Multiple different substituents are listed in alphabetical order. Ignore any of the prefixes from rule 4. In the current example, the 5-ethyl- comes before the 3-methyl-.
6. Commas are used to separate multiple numbers. Hyphens come between the number and the name of the substituent. The parent name comes immediately after the last substituent. There are no blank spaces in the name.
The correct name for the above structure, according to the IUPAC system, is 5-ethyl-3-methyloctane.
## Summary
• A structural isomer is one of multiple molecules that have the same molecular formula, but different structural formulas.
• Nomenclature rules for branched hydrocarbons are given. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5786418914794922, "perplexity": 1312.4227454463223}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-43/segments/1634323587926.9/warc/CC-MAIN-20211026200738-20211026230738-00399.warc.gz"} |
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# Computing with dynamical systems based on insulator-metal-transition oscillators
Abhinav Parihar
• Georgia Institute of technology, School of Electrical and Computer Engineering, Atlanta, GA 30332, USA
• Other articles by this author:
/ Nikhil Shukla
/ Matthew Jerry
/ Suman Datta
/ Arijit Raychowdhury
• Corresponding author
• Georgia Institute of technology, School of Electrical and Computer Engineering, Atlanta, GA 30332, USA
• Email
• Other articles by this author:
Published Online: 2017-04-19 | DOI: https://doi.org/10.1515/nanoph-2016-0144
## Abstract
In this paper, we review recent work on novel computing paradigms using coupled oscillatory dynamical systems. We explore systems of relaxation oscillators based on linear state transitioning devices, which switch between two discrete states with hysteresis. By harnessing the dynamics of complex, connected systems, we embrace the philosophy of “let physics do the computing” and demonstrate how complex phase and frequency dynamics of such systems can be controlled, programmed, and observed to solve computationally hard problems. Although our discussion in this paper is limited to insulator-to-metallic state transition devices, the general philosophy of such computing paradigms can be translated to other mediums including optical systems. We present the necessary mathematical treatments necessary to understand the time evolution of these systems and demonstrate through recent experimental results the potential of such computational primitives.
## 1 Introduction
Computing is the backbone of the modern society; from economics to security and scientific advancement to social welfare, each and every aspect of our lives has been enriched by the technology revolution. We have enjoyed the benefits of Moore’s Law over the last four decades as technology scaling brought the power of supercomputers to our Smartphones. With increasing challenges in scaling came ground-breaking innovations in the transistor technology. As we look ahead, limits of traditional scaling are already in sight. The demise of Dennard scaling and slowing down of Moore’s Law have further exposed the fundamental scaling limitations of the Von Neumann execution models of computing. This transition is accompanied by the realization that in a fast-evolving, socially interconnected world, we are observing a seismic shift in the amount of unstructured data that need to be processed in real-time, and consequently, future systems will be limited by the energy growth of data movement rather than that of compute. Therefore, we need fundamentally new approaches to sustain the exponential growth in performance beyond the end of the Complementary metal–oxide–semiconductor (CMOS) roadmap. This will require new execution models, coupled with new devices to implement them. In particular, we observe that new models that deal with data analytics have compute and storage interleaved in a fine-grained manner – not separated as in the Von Neumann world. Moving forward, computing technology will heavily penalize separation of data and compute and we need to marry them in better ways to handle emergent applications. This may necessitate that barriers of abstraction are broken. Next generation of computational models should map natively to the physics and dynamics of the physical devices, without a Boolean abstraction. Of course, it is a fool’s endeavor to assume that the Von Neumann architecture will perish; rather, newer computing models and dedicated hardware accelerators will supplement traditional Von Neumann machines in “data- centric” tasks.
In today’s computing landscape, ever harder problems are being encountered each day. From social networks to graph analytics, from weather prediction to scientific computation, computationally hard problems are present everywhere. Some of these problems are challenging just because of the sheer size of the datasets, but many other problems like optimization problems, although small in size, are intractable because of their inherent complexity and often combinatorial nature of solution spaces [1]. The sequential Von Neumann machine has been useful for most problems we have encountered in the past, but as the complexity of problems increases, significant research is underway for alternative paradigms, architectures, and hardware that can be used for solving complex problems more efficiently. Most of these efforts borrow essential ideas from natural computing processes. These include distributed computing, distributed memory, integrated processing and memory, shifting information representation from symbolic to physically meaningful quantities, and switching from sequential discrete time to continuous time dynamics.
Among the different problems of interest, associative computing, scientific computing [including solution of coupled partial differential equations (PDEs)], and optimizations form important classes of data-centric as well as model-centric computations. Active research in all these areas suggests that analog or continuous time systems may offer alternative faster and more energy-efficient solutions that their traditional digital counterparts. For example, in case of hard optimization problems, alternative paradigms and architectures include, but are not limited to, cellular automata [2], quantum computing [3], Ising model based systems [4], [5], neural networks [6], stochastic searching architectures [7], and memcomputing [8]. Among architectures for solving PDEs, cellular neural networks (CNNs) have been studied [9], [10]. Some studies have also suggested using cellular automata for solving PDEs [11].
The basic philosophy of most of these networks for optimization, e.g. artificial neural networks, is to first come up with an energy function that can be a penalty function or a rewarding function depending on how far the current solution is from the optimal solution [6]. The next step is to tune the parameters of the network such that as time evolves, the dynamics of the system decreases the penalty function or increases the reward. But even if such a massively parallel system is devised, which can solve NP-hard optimization problems, exponential resources of space, time, or precision will be required [12], [13]. Another direction is often explored where instead of trying to solve the optimization exactly, an approximation is targeted, which works well for most problems on average and allows less optimal solutions in harder instances. There can be other kinds of trade-offs like in the case of Hopfield networks where even though the optimal solution maps exactly to global minima, there can be too many local minima where the system can get trapped. Finally, the physical layer of computing, namely the semiconductor device platform, needs to be able to support such systems and the CMOS transistor is not always an optimal device choice.
Recently, the development of novel phase transition materials like vanadium dioxide (VO2) and corresponding electronic devices, which show insulator-to-metal transitions (IMTs) [14], has sparked interest in creating compact relaxation oscillators [15], [16]. These oscillators, when coupled to each other, exhibit phase synchronization, which can be used for phase-based computing. Such new kinds of devices present interesting opportunities to create systems with novel synchronization dynamics. The impact of using such devices as basic units in circuits can break the abstraction between the physical and the algorithmic layers of computing. It should be noted that the synchronization dynamics of coupled oscillators not only have a wide variety of applications in engineering but also explain many natural, chemical, and biological synchronization phenomena like the synchronized flashing of fireflies, pacemaker cells in the human heart, chemical oscillations, neural oscillations, and laser arrays, to name a few. These novel computing primitives, of course, are neither drop-in replacements for CMOS transistors nor straightforward extensions of the existing computing architectures. It requires rethinking of the basic computational entities in new kinds of system architectures. In this paper, we review some computational models using coupled relaxation oscillators based on VO2 metal-insulator transition (MIT) devices focusing on how the system dynamics can be modeled and the applications they can enable. We limit our discussion on applications in image processing for the sake of brevity. However, the potential of dynamical systems extends far beyond image analytics and promises to be a competing computational model for post-CMOS technologies.
## 2 A perspective on coupled oscillatory networks
The area of coupled oscillators has been dominated mostly by theoretical models and numerical simulations but has very few successful physical implementations. The reason is that the assumptions made for analytical simplification in those theoretical models are too difficult to realize in practice. Also an important limitation of such systems, which is true for any dynamical system, is that if a dynamical system is able to solve computationally hard (NP-class) problems exactly, then it necessarily has to be chaotic in nature, which would require exponential precision in both simulations and physical implementations.
The most popular coupled oscillator models in this area are the Kuramoto oscillator models [17], which rely on sinusoidal oscillators coupled using “weak” and linear phase coupling. A Kuramoto system of N oscillators is described by the following:
${\stackrel{˙}{\theta }}_{i}={\stackrel{˙}{\omega }}_{i}+\frac{K}{N}\sum _{j=1}^{N}\mathrm{sin}\left({\theta }_{j}-{\theta }_{i}\right),\text{\hspace{0.17em}}i=1,\text{\hspace{0.17em}}\dots ,\text{\hspace{0.17em}}N,$
where θi and ωi are the phase and frequency, respectively, of ith oscillator. Major challenges in this kind of coupled oscillator model are the notion of weak coupling, i.e. KN, and the idea that the coupling effects phase only without disturbing the frequencies. Moreover, creating arrays of compact sinusoidal oscillators with many oscillators coupled to each other poses serious challenges given the requirements. Similar models of weak linear phase coupling were also explored for Van Der Pol oscillators [18], which have an additional nonlinearity. But the implementation of such oscillators is also non-trivial, and the coupling behavior becomes too complicated to tackle large, connected networks [19], [20], [21], [22].
Nevertheless, the ability of coupled oscillatory systems to encode computing has long been realized. Associative computing, with applications in pattern detection and machine learning, has been demonstrated in theory. Similarly oscillatory CNNs have been shown to possess extraordinary computing ability in solving problems as varied as template matching, PDEs and ODEs, and so on. More recently, this effort has been augmented by advances in the development of compact oscillators in non-silicon technologies. One prominent effort is the use of spin torque oscillators (STOs) coupled with using spin diffusion currents and providing a computational platform for machine learning, spiking neural networks, and others [23], [24]. However, the high current densities of STOs and the limited range of spin diffusion currents continue to pose serious challenges to technologists.
In our studies, we explore phase transition based relaxation oscillators with piecewise linear dynamics, which means the system is described by different linear dynamical systems in different “states” of the system. These states are basically charging and discharging of a capacitive element. The coupling is also electronic and is accomplished by linear capacitors and/or resistors. The repeated switching between these states gives rise to oscillatory behavior and the notion of phase. But because the switching is itself determined by the state variables (voltage thresholds) and not explicitly by time, the coupling dynamics and hence the overall system dynamics are often mathematically intractable and closed-form approximations like the Kumamoto model are not possible. This further complicates the analysis when the goal is to perform computation in phase space. Hence, model development coupled with numerical analysis and an intuitive understanding of how complex systems evolve over time become essential tools to engineer such systems. The relaxation oscillators we investigated are built using phase change devices, which are devices that switch states between a metallic state with low resistance and insulating state with high resistance depending on the voltage across them. In the next section, we will describe simple mathematical constructs that can assist in analyzing these oscillators and the results obtained once they are coupled electrically.
## 3.1 State-changing devices
The state-changing devices we consider are essentially linear conductances (or resistances) but can transition between two conducting states – insulating state with conductance gdi and metallic state with conductance gdm. We assume that gdmgdi. They are also called IMT devices. We use VO2 as the material choice. A state transition is triggered by the voltage applied across the devices as well as the history. When the voltage across the device increases above a higher threshold voltage Vh, the device changes its state to metallic with conductance gdm, and when the voltage decreases below a lower threshold Vl, it changes to insulating state with conductance gdl. There is hysteresis in switching, i.e. VhVl, which means when the voltage applied is between Vh and Vl, the device retains the last state it was in. An internal capacitance is associated with the device that ensures gradual buildup and decaying of the voltage (and energy) across the device. Rigorous mathematical analysis of such oscillator configurations can be found in Ref. [25].
## 3.2 Single oscillator configurations
There can be multiple configurations/circuits of a relaxation oscillator based on state-changing device. On a simplistic level, two basic configurations exist – (a) two state-changing devices in series, called D-D, where D stands for device (Figure 1A), and (b) a state-changing device in series with a resistance, called D-R (Figure 1B). In the former, the charging and discharging rates are equal, but they are different in the latter. The functioning of the two circuits is as follows.
Figure 1:
(A) D-D oscillator circuit configuration and its equivalent circuit. (B) D-R oscillator circuit configuration and its equivalent circuit. (C) Load line graph for the D-R circuit and the region of operation of D-R oscillator. When the stable points (green filled points) are outside the region of operation, the system shows oscillations.
In case of two devices in series D-D, the two devices must be in opposite conduction states (one metallic and the other insulating) all the time for oscillations to occur. If the threshold voltages vl and vh are equal for the devices and the following condition holds:
$Vl+Vh=VDD$(1)
and at t=0, the devices are in different conduction states, then any time one device switches, the other will make the opposite transition as well. As gdmgdi, the devices can be considered as switches, which are open in insulating state and closed in metallic with conductance gdm. The mechanism of oscillations is essentially charging and discharging of the internal capacitances of the devices. The device in metallic state connects the circuit and charges (discharges) the lumped internal capacitance. The voltage at the output node increases (decreases) and eventually reaches the threshold voltage. Because of (1), both devices will switch at the same time, causing their behavior to switch. The charging (discharging) becomes discharging (charging), and the cycle continues. The modeling of a D-D oscillator is as follows. All the lowercase voltages referred in the paper are normalized voltages with respect to VDD, which means vh =Vh/VDD and vl =Vl/VDD. Also vdd is used as normalized and hence vdd =1.
The single D-D oscillator can be described by the following set of piecewise linear differential equations:
$c{v}^{\prime }=\left\{\begin{array}{ll}\left({v}_{dd}-v\right){g}_{1dm}\hfill & \text{charging}\hfill \\ -{g}_{2dm}\hfill & \text{discharging}\hfill \end{array},$
where g1dm and g2dm are metallic conductances of the two devices, respectively. As gdigdm, there is no term involving gdi in the equations. The equation can be re-written as follows:
$c{v}^{\prime }=-g\left(s\right)v+p\left(s\right)$
where s denotes the conduction state of the device (0 for metallic and 1 for insulating) and g(s) and p(s) depend on the device conduction state s, as follows:
$\begin{array}{l}g\left(s\right)=\left\{\begin{array}{ll}{g}_{1dm},\hfill & s=0\hfill \\ {g}_{2dm},\hfill & s=1\hfill \end{array}\\ p\left(s\right)=\left\{\begin{array}{ll}{g}_{1dm},\hfill & s=0\hfill \\ 0,\hfill & s=1\hfill \end{array}.\end{array}$
For D-R oscillators, the oscillations occur due to a lack of stable point as seen in the load line graph of Figure 1C. Solid sloped lines are the regions of operation of the device in insulating and metallic states, respectively. The system does not enter the dashed sloped lines as a transition occurs to the other conduction state at the red points. The stable points, denoted by green points, are the points where the load line intersects the I-V curve of the device. These stable points in each state lie outside the region of operation of the circuit, and hence, the circuit shows self-sustained oscillations. This is a much more practical configuration from an electrical implementation point of view, as the conditions required for oscillations are not very strict. Following a similar analysis as in the D-D oscillator case, the dynamics of the single D-R oscillator can be described as follows:
$c{v}^{\prime }=\left\{\begin{array}{ll}\left({v}_{dd}-v\right){g}_{dm}-v{g}_{s}\hfill & \text{charging}\hfill \\ -v{g}_{s}\hfill & \text{discharging}\hfill \end{array},$
which can be re-written as follows:
$c{v}^{\prime }=-g\left(s\right)v+p\left(s\right),$
where
$\begin{array}{l}g\left(s\right)=\left\{\begin{array}{ll}{g}_{dm}+{g}_{s},\hfill & s=0\hfill \\ {g}_{s},\hfill & s=1\hfill \end{array}\\ p\left(s\right)=\left\{\begin{array}{ll}{g}_{dm},\hfill & s=0\hfill \\ 0,\hfill & s=1\hfill \end{array}\end{array}$
and s denotes the conduction state of the system as before. Detailed analysis of configurations and modeling of such oscillators can be found in Ref. [25].
## 3.3 Pairwise coupling
Analysis of two coupled relaxation oscillators can give interesting insights into how such coupling dynamics can be used in various computing applications and can also help understand and exploit dynamics from complex couplings. There can be many ways in which the oscillators can be coupled. We have looked at coupled oscillator circuits where the oscillators are coupled through their output nodes using a capacitance, a resistance, or a parallel RC combination (Figure 2).
Figure 2:
D-D (A) and D-R (B) coupled oscillator circuits using parallel RC circuit as the coupling circuit.
## 3.3.1 D-D oscillators
The D-D configuration, although difficult in an electrical implementation point of view, is very simple to analyze and gives interesting insights about dynamics of such piecewise linear systems. Two identical D-D oscillators coupled using a RC circuit can be modeled as follows. When coupled, the system has four conduction states s=s1s2∈{00, 01, 10, 11} corresponding to the four combinations of s1 and s2. The coupled system can be described in matrix form as follows:
$\begin{array}{c}{c}_{c}F{x}^{\prime }\left(t\right)=-{g}_{c}A\left(s\right)x\left(t\right)+P\left(s\right)\\ {x}^{\prime }\left(t\right)=-\frac{{g}_{c}}{{c}_{c}}{F}^{-1}A\left(s\right)\left(x\left(t\right)-{A}^{-1}\left(s\right)P\left(s\right)\right),\end{array}$
where x(t)=(v1(t), c1(t)) is the state variable at any time instant t. The 2×2 matrices F and A(s) and vector P(s) are given by the following:
$\begin{array}{l}\phantom{\rule{1em}{0ex}}\phantom{\rule{1em}{0ex}}F=\left[\begin{array}{cc}1+{\alpha }_{1}& -1\\ -1& 1+{\alpha }_{2}\end{array}\right]\\ \begin{array}{cc}A\left(00\right)=\left[\begin{array}{cc}-{\beta }_{11}-1& 1\\ 1& -{\beta }_{21}-1\end{array}\right],& P\left(00\right)=\left[\begin{array}{c}{\beta }_{11}\\ {\beta }_{21}\end{array}\right]\\ A\left(10\right)=\left[\begin{array}{cc}-{\beta }_{12}-1& 1\\ 1& -{\beta }_{21}-1\end{array}\right],& P\left(10\right)=\left[\begin{array}{c}0\\ {\beta }_{21}\end{array}\right]\\ A\left(01\right)=\left[\begin{array}{cc}-{\beta }_{11}-1& 1\\ 1& -{\beta }_{22}-1\end{array}\right],& P\left(01\right)=\left[\begin{array}{c}{\beta }_{11}\\ 0\end{array}\right]\\ A\left(11\right)=\left[\begin{array}{cc}-{\beta }_{12}-1& 1\\ 1& -{\beta }_{22}-1\end{array}\right],& P\left(11\right)=0\end{array}.\end{array}$
Here, αi =ci/cc is the ratio of the combined lumped capacitance of ith oscillator to the coupling capacitance cc, and βij =gijdm/gc is the ratio of the metallic state conductance of jth device of ith oscillator to the coupling conductance, where i∈{1, 2} and j∈{1, 2}. The fixed point in a conduction state s is given by ps =A−1(s)P(s), and the matrix determining the flow (the flow matrix or the velocity matrix) is given by $\frac{{g}_{c}}{{c}_{c}}{F}^{-1}A\left(s\right).$
When two identical D-D oscillators are coupled using a parallel RC circuit with coupling resistance RC =1/gc and coupling capacitance CC, they can lock in-phase or anti-phase depending on the relative values of RC and CC. In the extreme case of purely capacitive coupling with gc =0, the anti-phase locking orbit is stable and the in-phase locking orbit is unstable. In case of purely resistive coupling with CC =0, the in-phase locking orbit is stable and the anti-phase locking orbit is unstable. For other values, the system always has in-phase locking periodic orbit as well as anti-phase periodic locking orbits, with the stable locking being the in-phase locking when the coupling is close to purely resistive, and when the coupling is close to purely capacitive, the stable locking is the anti-phase locking. Interestingly, considering the parameter space of RC and CC, there exists a region with bistable orbits, i.e. both the in-phase and anti-phase orbits are stable. In this region, the steady-state locking depends on the initial starting voltages at t=0 of the oscillators.
## 3.3.2 D-R oscillators
From a computing application point of view, pairwise coupled D-R oscillators have interesting applications. When the series resistances are replaced by transistors, as shown in Figure 3, and the coupling is a simple capacitive coupling, a pair of coupled D-R oscillators can be used as an analog comparator whose output has the form of a difference norm [16], [26], [27]. Typical steady-state orbits of the coupled system plotted in a v1×v2 plane are shown in Figure 4A. When vgs1vgs2 increases, the steady-state orbits of the oscillators get deformed. Such deformation of the steady-state orbits can be measured using a simple averaged thresholding-and-XOR operation on the steady-state outputs of the oscillators. This averaged XOR measure is defined as, first, thresholding the output to binary values; second, applying XOR operation on these binary values at every time instant; and finally, averaging this XOR output over some time duration. The averaged XOR output as a function of vgs1 and vgs2 is shown in Figure 4B. The XOR surface reaches minimum value along the line vgs1=vgs2. Within the locking range, it rises as an even function of vgs1vgs2 resembling a difference norm. Outside the locking range, it averages to about 0.5. These characteristics of the curve can be explained by realizing that the averaged XOR measure by construction is equal to the fraction of the time the system spends in the grey region (region where XOR output is 1 – determined by the thresholds on v1 and v2) in steady state, as shown in Figure 4A. It can be seen that the XOR measure should have the lowest value in the symmetric case vgs1=vgs2 when the system locks out-of-phase and should increase as values diverge. Such a system can be used as an analog comparator with output as a difference norm. Arrays of such comparators can be used for template matching applications where element-wise comparisons suffice to decide a match.
Figure 3:
(A) Oscillator circuit with MOSFET in series with a VO2 device. (B) Small signal equivalent circuit of the oscillator with VO2 in series with a MOSFET. (C) Coupled oscillator circuit with a series MOSFET in place of a series resistance.
Figure 4:
(A) Relationship between XOR output and the steady-state periodic orbit of the system. At any instant of time, XOR output is 1 in the grey region and 0 otherwise. Averaged XOR output is equal to the fraction of time spent by the system in the grey regions. XOR output is minimum in case of a butterfly-shaped orbit (left) and should increase as the orbit transitions to a rectangular orbit (right). (B) XOR surface as a function of vgs1 and vgs2.
## 4.1 IMT basics
VO2 undergoes a first-order metal-insulator phase transition marked by an abrupt change in conductivity up to five orders in magnitude. This abrupt change in conductivity, which is also accompanied by changes in optical properties and can be triggered externally using thermal [28], optical [29], electronic [30], or strain [31] stimuli, can pave the way for novel electronic devices including steep slope switching devices, memory elements, and ultra-fast optical switches. One of the characteristic features of the electrically driven first-order MIT in VO2 is its inherently hysteretic nature, as shown in Figure 5A. In previous publications, we demonstrated an electric field driven non-hysteretic phase transition in VO2 and showed novel device functionalities like coupled oscillations that may enable efficient implementation of novel, non-Boolean computing models. The electrically driven first-order phase transition results in abrupt switching in conductivity but always comes at the cost of an intrinsic hysteresis, because the electrical field at which IMT occurs is always higher than that at which the MIT happens. Further, the electrically driven phase transition in VO2 is also accompanied by a dramatic reduction in the optical transmission across the IMT [32]. These optical properties can not only be used as a probe for understanding the fundamental physics of the phase transition but also be harnessed for engineering phase transition devices and circuits, as discussed in Section 4.2. In our experiments, VO2 is epitaxially grown on (001) TiO2 (−0.86% compressive strain) using molecular beam epitaxy (MBE), then patterned to form channels and followed by deposition of Au/Pd contacts to electrically access the VO2 channel. First, the device is electrically driven across the phase transition boundary with zero external series resistance. A current compliance is set to limit the current in the metallic state (to prevent excess Joule heating resulting in permanent damage). The IMT and the reverse MIT occur at two critical fields, E2 and E1, respectively. The critical field E2 is the field required to attain the Mott criteria and thereby triggers the formation of the metallic phase. As transport in the insulating phase is dominated by hopping transport, we use the field-dependent hopping conductance to understand its electrical properties.
Figure 5:
(A) Measured I-E characteristics of a VO2 device illustrating the hysteretic window. (B) Measured characteristics show oscillations when biased with a pull-down resistor. (C) Measurements and simulations illustrate frequency locking when two oscillators are coupled electrically.
The negative differential resistance (NDR) region, where VO2 is characterized by a conductivity intermediate between the metallic and insulating states, is referred to as the phase coexistence region. The net conductivity in this region is due to contributions from the metallic and insulating phase. In situ nano XRD characterization performed simultaneously with the transient waveform measurement confirms that the nature of the insulating phase is Monoclinic M1 and that of the metallic phase is Rutile, which is expected as the films are −0.86% compressively strained. When such a phase transition device is operated in the hysteretic region, it breaks into spontaneous oscillations, as shown in Figure 5B. This is a relaxation oscillator with piecewise linear dynamics, as has been discussed in the previous section.
## 4.2 Coupling IMT oscillators: electrical and optical
While we have focused on electrical devices and coupling schemes using resistors and capacitors as discussed above, our work has significant synergies with nanophotonics and optics. Optical properties of the phase transition materials could be leveraged for designing peripheral circuitry of a chip-scaled coupled oscillator system. For instance, even in the electrical realization (as shown here) of large coupled oscillatory systems, one of the major challenges is to be able to measure simultaneously, speedily, and accurately the phase of the oscillators as the phase dynamics form the fundamental basis of the computational primitive using coupled oscillators. An optical phase read-out scheme can potentially be designed for the oscillators, as the VO2-based phase transition devices show a significant change in optical response across the phase transition; the optical transmission dramatically reduces as VO2 undergoes IMT [33]. Further, optically tuned VO2 has been shown as a memory capacitance and thus can be potentially incorporated as a tunable coupling element in the coupled oscillator system. Additionally, the ability to manipulate the coupling strength using well-known nanophotonics techniques such as colossal electro-optic or thermo-optic effects increases their future potential to realize large-scale on-chip nonlinear dynamical systems.
The ideas and the computational models developed using IMT-based coupled oscillators can also be explored for other oscillatory computing systems. For instance, Ref. [34] demonstrates experimentally the synchronization of a pair of silicon nitride optomechanical oscillators (OMOs) that are optically coupled through the radiation pressure field as opposed to mechanically coupled. The researchers were able to turn the optical coupling on and off using a heating laser via thermos-optic effect.
Overall, this is an area of research that lies unexplored from a computational point of view, and success in creating complex systems with many to many connections will be key to achieving hardware platforms capable of truly delivering the promise of coupled dynamical systems as computational elements.
## 5.1 Image data processing and analytics
Arrays of such IMT oscillator based comparators can be used for template matching applications where element-wise comparisons suffice to decide a match. Figure 6A, B illustrates the XOR-ed output of the phases of two coupled oscillators configured as in Figure 3. We observe from Figure 6C, D a close match between experiments and simulations, and it demonstrates that the XOR measure between the outputs of the two oscillators can be used as a measure of distance between two inputs as given by ΔVGS =VGS1VGS2.
Figure 6:
(A, B) XOR output of pairwise coupled oscillators shows close similarity with fractional norm measure between two inputs. (C, D) Experimental results and simulations reveal the capability of coupled oscillator phases to encode a measure of difference between two inputs (ΔVGS). (E) Saliency detection of images using coupled oscillator systems and a digital implementation, (F) a pairwise XOR measure is extended to illustrate pattern matching between an input and a template. A lighter color corresponds to a better match.
We investigate the application of pairwise coupled oscillators for visual saliency approximations (detecting parts of the image that visually standout). Oscillator-based edge detection is performed using an array of pairwise oscillators to approximate the degree of dissimilarity between a given image pixel and its immediate neighbors. Different edges, vertical, horizontal, diagonal, are detected based on the selection of neighboring pixels for comparison. As this concept is expanded to include the comparison of pixels within a larger neighborhood (pixels surrounding reference pixel; a 3×3 neighborhood is used here), the output approximates the visual saliency. We also note that pairwise coupling of oscillators leads to the inherent calculation of fractional norms between templates and inputs, a task that is notoriously painstaking on a digitally abstracted computer. It is evident from Figure 6E that the coupled oscillators show higher sensitivity to image contrast in comparison to a CMOS ASIC accelerator that uses a linear norm.
We further demonstrate this by comparing images of faces and hand-written numbers, as shown in Figure 6F. We first use the XOR measure for each pixel and calculate the number of pixels with XOR output below a threshold value. Figure 6F shows the results of comparing faces with a relaxation comparator, where the grey shade corresponds to the fraction of pixels with positive match, white being the highest. Such system followed by a winner-take-all (WTA), i.e. a threshold on the number of pixels that give a positive match, can be used to decide if the input image matches a stored template pattern. The value is chosen around 0.2 considering the minimum values of the XOR surface in the operating range of values. The two thresholds described above depend on different factors. The threshold of the number of pixels for WTA would depend on the database and the error statistics required or estimated. On the other hand, it would be decided more by the nature of the XOR surface (Figure 4B) and its minimum values.
A coupled VO2-MOSFET configuration cascaded with a XOR provides a way of measuring a form of fractional distance using FSK. Such associative networks can be used in more complex pattern matching and classification problems with potentially large benefits in energy efficiency. The advantages of such oscillator based computing systems can be truly harnessed if they are miniaturized, made compact, and integrated. The authors would like to note that the technological realization of such a coupled oscillator system would have to account for variation effects such as device-to-device variations (switching speed, switching voltages and currents, hysteresis) in VO2 as well as variations in the series transistor such as threshold voltage mismatch among the FETs and their effects on algorithms as well as on computational performance. While a holistic study of variation effects will require the development of systems beyond small prototypes currently under investigation, the authors have addressed some of the effects of variations on computational tasks such as pattern matching in previous publications [27].
We expect such systems to provide large improvements in energy efficiency, opening up possibilities in areas as varied as surveillance, consumer electronics, and in-sensor processing. For comparison, a digital baseline design is designed and simulated. All digital circuits are implemented with 11-nm node transistor models. We observe that the coupled oscillators provide a power reduction of 20× over CMOS, reflecting the advantage of letting physics do the computing approach and potentially removing the Boolean bottleneck. For further details, interested readers are pointed to the previous work by the authors [16].
## 5.2 Complex global connections and possibilities for computation
The full computational power of such coupled dynamical systems can be further harnessed using complex global interactions among oscillators instead of just pairwise interactions. Such coupled oscillators provide a Hopfield type networks but with piecewise linear dynamics and hysteretic switching of oscillators. When connected in complex networks with both global and local connectivity, instead of pairwise coupling, these networks of oscillators can be much more powerful and can possibly compute approximate solutions of many hard optimization problems. In one implementation of globally coupled D-R oscillators (with a series resistance), we have recently demonstrated using theory and experimental implementations that such networks are capable of approximating the solution of NP-hard minimum graph coloring problems [35]. When n identical D-R oscillators are coupled using identical capacitors, such network settles to a steady state wherein the relative phases of the oscillators get ordered in a way that corresponds to the solution of graph coloring. The time evolution of the piecewise linear dynamical system of such coupled D-R oscillators inherits the properties of and hence mimics approximate graph coloring algorithms because of the construction of such networks. Basic functioning of such a system is shown in Figure 7.
Figure 7:
Overview of the proposed graph coloring system using coupled VO2 oscillators where each node corresponds to a VO2 oscillator. The dynamics of the system corresponds to an approximate graph coloring algorithm, and as such, the steady-state phase output of the VO2 oscillators can be used to color the nodes of the graph.
## 6 Concluding remarks
In this article, we have demonstrated that the dynamics that evolves from the complex interactions among oscillators can be a powerful computing paradigm. However, this requires innovations in fabrication of compact and coupled networks of oscillators, and the current implementation using phase transition devices is one promising candidate. Even with advances in post-silicon devices and technology, the true potential of integrated dynamical systems can only be harnessed when controllable and programmable coupling can be realized and the phase and frequency dynamics carefully measured and read out. A plethora of challenges remain; however, the opportunities offered by dynamical systems to make a significant impact in a post-CMOS world are undeniable.
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Revised: 2016-11-10
Accepted: 2016-12-04
Published Online: 2017-04-19
Citation Information: Nanophotonics, Volume 6, Issue 3, Pages 601–611, ISSN (Online) 2192-8614, ISSN (Print) 2192-8606,
Export Citation | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 11, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7510600686073303, "perplexity": 1763.4982081581968}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-26/segments/1529267866932.69/warc/CC-MAIN-20180624102433-20180624122433-00445.warc.gz"} |
https://gamedev.stackexchange.com/questions/101548/drawing-text-with-slick | # Drawing text with Slick
I've been trying to draw a text to the display using Slick. However, when ever I draw the TrueTypeFont to the screen, it draws it reversed upside down and also, it makes the whole display turn black.
This is only a piece of the entire game code, I think this is enough to explain the problem though. I'm new to LWJGL and Slick so this is probably a stupid question.
public Game(String name, int width, int height)
{
this.name = name;
this.width = width;
this.height = height;
try {
Display.setDisplayMode(new DisplayMode(width, height));
Display.setTitle(name + " " + version);
Display.setResizable(true);
Display.create();
} catch (LWJGLException e) {
e.printStackTrace();
Display.destroy();
return;
}
TrueTypeFont font;
Font awtFont = new Font("Arial", Font.PLAIN, 24);
font = new TrueTypeFont(awtFont, false);
Player player = new Player(this, 32, 32);
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
while(!Display.isCloseRequested())
{
glClear(GL_COLOR_BUFFER_BIT);
glMatrixMode(GL_PROJECTION);
glOrtho(0, width, 0, height, -1, 1);
glMatrixMode(GL_MODELVIEW);
drawBackground();
player.update();
player.draw();
font.drawString(50, 50, "Platform");
Display.update();
Display.sync(60);
}
Display.destroy();
}
Edit: After doing what @Katu said, I changed glOrtho(0, width, 0, height, -1, 1); to glOrtho(0, width, height, 0, -1, 1);. The text is not reversed upside down, but the black screen is still there.
The screen should look something like this. (NOTE: It's an edited image)
Change
glOrtho(0, width, 0, height, -1, 1);
To this:
glOrtho(0, width, height, 0, -1, 1);
A quick little understanding about why your font wasn't working (if you don't already know), glOrtho is called like this:
glOrtho(double left, double right, double bottom, double top, double zNear, double zFar).
This being said, you had the bottom set to 0 where it should have been set to the display's height or a custom bottom if necessary and that is the reason why the text was facing the top of the screen or rather, being drawn up-side down.
I collected this answer from these:
• Thanks, that solved the main problem. Now it's showing a black screen with a text saying "Platform" when it's suppose to draw the player, the background, and the text. Here's a screenshot. – Vicente Bermúdez May 27 '15 at 16:03
• @VicenteBermúdez Test if this helps -> glEnable(GL_TEXTURE_2D); ( Add it to near glEnable(GL_BLEND); ) – Katu May 27 '15 at 16:15
• I tried that and it's still remains the same. It should look something like this – Vicente Bermúdez May 27 '15 at 16:22
• @VicenteBermúdez Then try glBindTexture (GL_TEXTURE_2D,0) If this wont work, I'm out of bullets – Katu May 27 '15 at 18:20
• That makes it draw a white rectangle instead of a text. The background and player is working now but the text isn't. Thanks though :) – Vicente Bermúdez May 27 '15 at 18:44 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.47621607780456543, "perplexity": 3867.6433978514015}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-43/segments/1570987833089.90/warc/CC-MAIN-20191023094558-20191023122058-00440.warc.gz"} |
https://www.physicsforums.com/threads/for-interest-compounded-on-yearly-basis-how-much-will-be-paid-back-in-3-5-years.773172/ | # For interest compounded on yearly basis, how much will be paid back in 3.5 years?
Tags:
1. Sep 27, 2014
### SafiBTA
- This may be a stupid question as I am totally new to the concept of interest. I don't even know if my question is valid.
- Figure is given below for reference
Suppose I deposit some money in a bank that pays compound interest on yearly basis. If I decide to withdraw my amount at the end of 3.5 years, which of the following amounts will the bank pay me back:
a. the amount accumulated at the end of 3 years ($450, as represented by blue plot) b. the amount accumulated at the end of 3 years + a simple interest on this amount computed over 6 months ($560, as represented by the black plot; since compound interest is essentially the simple interest on the last accumulated amount)
c. the amount accumulated at the end of 3.5 years ($540, represented by red plot) As far as I can think, it can't be c since the interest is compounded discretely and not continuously. How is this problem usually tackled? It looks like the amount depends upon the regional laws, but I just want to clarify my concepts. 2. Sep 27, 2014 ### mfb ### Staff: Mentor That depends on the contract you signed. There is also (d)$450, but you can get \$90 more at the end of the year (where do you get that crazy interest rate? :p)
3. Sep 27, 2014
### Staff: Mentor
Annually compounded interest would be a. The black line never happens in my experience, and the red line never intersects the blue.
4. Sep 27, 2014
### pwsnafu
In the actuary exams (specifically CT1 in UK and FM2 in US) the answer is always $a_0 (1+i)^{3.5}$. Simple interest is only ever used if the total time is less than a year (eg zero coupon bonds maturing in 4 months). There's a couple of reason for this, but the main one is that actuaries are interested in very long time frames, such as 50 years, so the error is proportionally small. Second, they assume "consistent markets" which means the accumulations can be multiplied with each other.
At the other extreme traders are interested in weekly or even daily returns, so they'll immediately take money out of an annually compounded account, into something which pays fortnightly or weekly, even if that means a lower effective interest over the year. It's the price you pay for flexibility.
In reality, it would be dependent on the contract.
Also, if such bank existed switch banks! The standard in real life is monthly compounding, not annual.
Last edited: Sep 27, 2014
5. Sep 27, 2014
### Locrian
I do not think that is true, and think that it is a dangerous assumption to use on exam FM. It's entirely possible that a question would be asked where interest is only calculated once a year, resulting in his answer A (taking to the third power).
6. Sep 27, 2014
### pwsnafu
The default assumption is consistent markets, that is the accumulation factors $A(t_1, t_2) \times A(t_2, t_3) = A(t_1, t_3)$ for any $t_1 < t_2 < t_3$. In order to work with force of mortality actuaries need to covert interest rates into the force of interest, which only works under this assumption.
Answer A is correct if the problem explicitly states not to assume consistency.
Edit: gets out lecture notes (my exams necessarily followed CT exams because they gave exemptions to them)
Last edited: Sep 27, 2014
7. Sep 27, 2014
### Locrian
When I took FM, they did not have to state that markets weren't consistent to set unusual intervals for interest to be calculated. I don't think this has changed, but I'll double check with a friend who took it recently to verify.
Sure, but you don't usually have to work with force of mortality. I've worked with long timeline calculations that included both interest and mortality, and never used force of mortality or force of interest. I think it's actually pretty rare to do so in actual practice, though it may depend on what area you're in.
8. Sep 27, 2014
### pwsnafu
Interesting. I wonder if that's a difference between US and UK?
Edit: I just read the April CT1 exam and they had this question
To me that only makes sense under consistent. But they don't state it anywhere. So I'm sticking with what I said: assume consistent unless specifically asked otherwise.
Last edited: Sep 27, 2014
Similar Discussions: For interest compounded on yearly basis, how much will be paid back in 3.5 years? | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 2, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5640006065368652, "perplexity": 1210.3251466404447}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-43/segments/1508187820700.4/warc/CC-MAIN-20171017033641-20171017053641-00563.warc.gz"} |
http://perimeterinstitute.ca/videos/topos-formulation-consistent-histories | # Topos formulation of Consistent Histories
Playing this video requires the latest flash player from Adobe. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9679396748542786, "perplexity": 28424.919216277733}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-26/segments/1498128320057.96/warc/CC-MAIN-20170623114917-20170623134917-00025.warc.gz"} |
https://alice-publications.web.cern.ch/node/7408 | Figure 14
Inclusive \psitwos-to-\jpsi cross section ratio (left) and \jpsi, \psitwos, \upsones, \upstwos, and \upsthrees \pt-integrated cross section per unit of rapidity (right) as a function of the collision energy in pp collisions~. In the left panel, the systematic boxes include the BR uncertainties from both resonances, on top of the MC input and signal extraction systematic uncertainties. The 13 TeV data point is computed from the published individual \jpsi and \psitwos \pt-integrated cross sections. The statistical and systematic uncertainties are assumed to be uncorrelated between the resonances when computing the ratio. In the right panel, the luminosity and branching ratio uncertainties are included in the systematic boxes. The data are compared with theoretical calculations from ICEM + FONLL~. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9837962985038757, "perplexity": 2036.1087103046093}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-49/segments/1637964358903.73/warc/CC-MAIN-20211130015517-20211130045517-00500.warc.gz"} |
http://codeforces.com/problemset/problem/986/E | E. Prince's Problem
time limit per test
3 seconds
memory limit per test
512 megabytes
input
standard input
output
standard output
Let the main characters of this problem be personages from some recent movie. New Avengers seem to make a lot of buzz. I didn't watch any part of the franchise and don't know its heroes well, but it won't stop me from using them in this problem statement. So, Thanos and Dr. Strange are doing their superhero and supervillain stuff, but then suddenly they stumble across a regular competitive programming problem.
You are given a tree with $n$ vertices.
In each vertex $v$ there is positive integer $a_{v}$.
You have to answer $q$ queries.
Each query has a from $u$ $v$ $x$.
You have to calculate $\prod_{w \in P} gcd(x, a_{w}) \mod (10^{9} + 7)$, where $P$ is a set of vertices on path from $u$ to $v$. In other words, you are to calculate the product of $gcd(x, a_{w})$ for all vertices $w$ on the path from $u$ to $v$. As it might be large, compute it modulo $10^9+7$. Here $gcd(s, t)$ denotes the greatest common divisor of $s$ and $t$.
Note that the numbers in vertices do not change after queries.
I suppose that you are more interested in superhero business of Thanos and Dr. Strange than in them solving the problem. So you are invited to solve this problem instead of them.
Input
In the first line of input there is one integer $n$ ($1 \le n \le 10^{5}$) — the size of the tree.
In the next $n-1$ lines the edges of the tree are described. The $i$-th edge is described with two integers $u_{i}$ and $v_{i}$ ($1 \le u_{i}, v_{i} \le n$) and it connects the vertices $u_{i}$ and $v_{i}$. It is guaranteed that graph with these edges is a tree.
In the next line there are $n$ integers $a_1, a_2, \ldots, a_n$ ($1 \le a_{v} \le 10^{7}$).
In the next line there is one integer $q$ ($1 \le q \le 10^{5}$) — the number of queries.
And in the next $q$ lines the queries are described. Each query is described with three integers $u_{i}$, $v_{i}$ and $x_{i}$ ($1 \le u_{i}, v_{i} \le n$, $1 \le x_{i} \le 10^{7}$).
Output
Print $q$ numbers — the answers to the queries in the order they are given in the input. Print each answer modulo $10^9+7 = 1000000007$. Print each number on a separate line.
Examples
Input
41 21 31 46 4 9 532 3 62 3 23 4 7
Output
3641
Input
61 22 32 41 55 6100000 200000 500000 40000 800000 25000033 5 100000006 2 35000004 1 64000
Output
19600012250999998215 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.4462939500808716, "perplexity": 377.42193703771716}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-26/segments/1529267862929.10/warc/CC-MAIN-20180619115101-20180619135101-00263.warc.gz"} |
http://planetmath.org/FunctionDifferentiableAtOnlyOnePoint | # function differentiable at only one point
Let $f\colon\mathbbmss{R}\to\mathbbmss{R}$ be the function
$f(x)=\begin{cases}x,&\mbox{when x is rational},\\ -x,&\mbox{when x is irrational}.\end{cases}$
See this entry (http://planetmath.org/FunctionContinuousAtOnlyOnePoint). Let $g\colon\mathbbmss{R}\to\mathbbmss{R}$ be the function
$g(x)=f(x)x.$
Then $g$ differentiable at $0$, but everywhere else non-differentiable.
Indeed, since
$\displaystyle g^{\prime}(0)$ $\displaystyle=$ $\displaystyle\lim_{h\to 0}\frac{f(h)h-f(0)0}{h}$ $\displaystyle=$ $\displaystyle\lim_{h\to 0}f(h)$ $\displaystyle=$ $\displaystyle 0$
$g$ is differentiable at $0$. If $g$ would be continuous at $x\neq 0$, then $f(x)=g(x)/x$ would be continuous at $x$. This result (http://planetmath.org/DifferentiableFunctionsAreContinuous) implies that $g$ is non-differentiable away from the origin.
Title function differentiable at only one point FunctionDifferentiableAtOnlyOnePoint 2013-03-22 15:48:16 2013-03-22 15:48:16 matte (1858) matte (1858) 6 matte (1858) Example msc 57R35 msc 26A24 FunctionContinuousAtOnlyOnePoint | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 20, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.987653911113739, "perplexity": 757.8460481660862}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-13/segments/1521257646875.28/warc/CC-MAIN-20180319101207-20180319121207-00755.warc.gz"} |
https://proofwiki.org/wiki/729 | # 729
Previous ... Next
## Number
$729$ (seven hundred and twenty-nine) is:
$3^6$
$1 \, 000 \, 000$ in base $3$
The $1$st solution to the approximate Fermat equation $x^3 = y^3 + z^3 \pm 1$:
$9^3 = 6^3 + 8^3 + 1$
The $1$st cube which can be expressed as the sum of $5$ positive cubes:
$729 = 1^3 + 3^3 + 4^3 + 5^3 + 8^3$
The larger of the $1$st pair of Smith brothers:
$7 + 2 + 8 = 2 + 2 + 2 + 7 + 1 + 3 = 17$, $7 + 2 + 9 = 3 + 3 + 3 + 3 + 3 + 3 = 18$
The $2$nd cube which can be expressed as the sum of $3$ positive cubes:
$729 = 1^3 + 6^3 + 8^3$
The $3$rd $6$th power after $1$, $64$:
$729 = 3 \times 3 \times 3 \times 3 \times 3 \times 3$
The number of different commutative binary operations that can be applied to a set with $3$ elements
The $3$rd power of $9$ after $(1)$, $9$, $81$:
$729 = 9^3$
The $6$th power of $3$ after $(1)$, $3$, $9$, $27$, $81$, $243$:
$729 = 3^6$
The $9$th cube number after $1$, $8$, $27$, $64$, $125$, $216$, $343$, $512$:
$729 = 9 \times 9 \times 9$
The $27$th square number after $1$, $4$, $9$, $16$, $25$, $36$, $\ldots$, $361$, $400$, $441$, $484$, $529$, $576$, $625$, $676$:
$729 = 27 \times 27$
The $38$th Smith number after $4$, $22$, $27$, $58$, $\ldots$, $576$, $588$, $627$, $634$, $636$, $645$, $648$, $654$, $663$, $666$, $690$, $706$, $728$:
$7 + 2 + 9 = 3 + 3 + 3 + 3 + 3 + 3 = 18$
The $46$th powerful number after $1$, $4$, $8$, $9$, $16$, $25$, $\ldots$, $400$, $432$, $441$, $484$, $500$, $512$, $529$, $576$, $625$, $648$, $675$, $676$:
$729 = 3^6$
## Historical Note
$729$ was particularly significant to the Pythagoreans, as it is $27^2$ as well as being $9^3$.
The philosopher Plato rejected the well-known length of the year as being (approximately) $365 \frac 1 4$ in favour of $364 \frac 1 4$, as the latter is $729$, that is $9^3$, days and nights.
This was on the grounds that:
... if one were to express the extent of the interval by which the tyrant is parted from the king in respect of true pleasure he will find on completion of the multiplication that he lives $729$ times as happily and that the tyrant's life is more painful by the same distance.
-- Plato's Republic: $588$
Various other interpretations of this passage have been suggested.
Plato combined the sequences of squares and cubes and their roots from $1$ to $3$ to get:
$1 + 2 + 3 + 4 + 8 + 9 = 27$
Charles Albert Browne, Jr. pointed out that the $27 \times 27$ magic square, being filled with the numbers from $1$ to $729$, has $365$ in the centre cell. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.989192545413971, "perplexity": 396.14514104975393}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-05/segments/1642320302715.38/warc/CC-MAIN-20220121010736-20220121040736-00404.warc.gz"} |
https://proxies123.com/how-to-solve-the-following-optimization-problem-with-two-constraints/ | How to solve the following optimization problem with two constraints?
$$G (x, y) = xk_1 + (1-x) log_2 (1+ frac {xyk_2} {1-x})$$,
subject to: $$0 le x le 1$$, $$0 le and le 1$$,
where $$k_1$$ Y $$k_2$$ They are two positive quantities. Individually it is observed that $$G (x, y)$$ is a concave function of $$x$$ when $$and$$ remains constant and is also a concave function of $$and$$ when $$x$$ It is considered as constant. What will happen when both restrictions are there? | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 10, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9925357103347778, "perplexity": 105.81201587178026}, "config": {"markdown_headings": false, "markdown_code": false, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": false}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-16/segments/1585371620338.63/warc/CC-MAIN-20200406070848-20200406101348-00104.warc.gz"} |
http://www.archive.org/stream/cihm_58861/cihm_58861_djvu.txt | # Full text of "The quadrupeds of North America [microform]"
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3
1
2
3
4
5
6
^
is^sa
^
THE
OF
NORTH AMERICA.
BY
JOHN JAMES AUDUBON, F.R.S,cfec.<fec.
AND
THE REV. JOHN LACHMAN, D.D., &c. <fec
VOL. II
NEW YORK:
G^EORO-E 11. LOCKWOOD
(LATE ROC LOCKWOOD A .so.\,, '
8 1 2 lij
;^
Entered, according to Act of Congress, in tlio year 1849, by
V. G. AUDUBON,
in il e Clerk's Office of the District Coun of tlie Southern District of New-York.
" " ■—-■—- —- I - - i Dor'n rur ii nj^j
liENUS LUTRA.— Ray., Cuv.,Mustela spec, Linn., Aonyx, Lksboh.
DENTAL FORMULA.
1--1
»-S
Incisive -; Canine ~; Molar ^ =36
1—1 a_«
The second inferior incisor on each side, a little receding in most of the
species ; the canine much dilated, hooked ; first superior molar, small,
blunt, and sometimes deciduous ; the second, cutting; the third, of'similar
form, but larger; the fourth, with two external points, but furnished with
a strong spur on the inner side ; the fifth has externally three small points
with a broad spur internally. The inferior molars in this genus vary
from five to six, the first being wanting in oome of the species.
Head large and flatfish, terminating in a blunt muzzle ; ears short and
round; tongue slightly paplllous. Body long and slender; legs short;
toes five on each foot. In some of the species the fifth toe on the hind
ibot is rudimental. Toes webbed, armed with short claws which are not
retractile. Tail, not as long as the body, thick, and flattened hori-
zontally.
Body covered externally with long, rigid and glossy hair, with u softer
shorter, downy fur intermixed.
On each side of the anus, there is a small gland secreting fetid matter
All the species are good swimmers, live along the banks of rivers and
ponds, and feed on fish.
The generic appellation is derived from Lutra-an Otter : from the
Greek >»t/»» (lous), wash.
There are eleven species enumerated by authors, inhabiting the follow-
VOL. II. 1
^
2
ing countries: Europe 1, Island of Trinidad 1, Guyana 1, Brazil 1, Kaint-
schatka 1, Java 1, Malay 1. Pondicherry 1, The Cape of Good Hope 1,
and North America a.
PLATE LI. — Male.
L. vellore nitido, saturate fusco ; mento gulSque fusco albis ; L. vii].
^are major.
CHARACTERS.
Larger than the European Otter, L. Vulgaris. Dark glossy brown •
chin and 'hroai dusky white ; five feet in length.
SYNONYMES.
LouTRE DE Canada, Buffon, vol. xiii., p. .326, t. 44.
Common OnEn, Pfiinniit, Arctic Zoolog., vol. i., p. 053.
Land Oiter, Waidun's Hist. U. S., p. 200.
LuTiii Canadensis, Siibine, Franklin's Journ., p. 653.
" Brasiliensis, Hiirlan, Fauna, p. 72.
" " Godinan, Ivat. llist., vol. i., p. 222.
" Canadensis, Dekay, Zool., p. 1., p. 30.
DESCRIPTION.
Head, large and nearly of a globular form ; nose, blunt and naked ;
lips, thick ; ears, round, slightly ovate, and closer together than in L.
Vulgaris, clothed densely with short hair on both surfaces ; bodj', long,
cylindrical; neck, long; legs, short and stout; moustaches, very rigid,
like bristles ; soles of the feet, thinly clothed with hair between the toes,
tubercles at the roots of the -law.s, naked ; feet, webbed to the nails ;
Tail, stout, gradually tapering toward the extremity, de|)resi';ed at the base,
continuing flattened through half its length ; at the base there are two
oval glands. The longer hairs covering the fur, are glossy and rigid ;
fur, soft, dense, and nearly as fine as that of the Beaver, continuing through
the whole extc'.. of the body even to the extremity of the tail, but shorter
H-
-^_.*-^^^
-riiv?*
8
We overlookrd the opportunity of iiistitiifinj,' j, cnrcful oomparison lir-
tvveen the skulls and tcctli of tlw European and American Otters, and
have now no aeeess to specimens of the former. We therefore tjuoto the
Ixnjj^iuu'e of Dr. Dekav, whose ohservations in this respect corresnond
with our recollections of a {roner;il com|)arison made at the Berlin Museum,
eleven years ago. "In their dentition the Otters are eminently charaeteri/.ed
hy the enormous dilation of the two posterior cheek teeth in the upiuTJaw.
Our species, in this particular, oflors Swuie variations from the Euro|)ean
Otter. The pemiltimale, jaw tooth, in our species, has a broad internal
heel directed o!)li(iuely forward, with a deep fissure dividing the surface
into two rounded and elevated portions ; and the ])ointed tubercle is broad,
with a high shoulder posteriorly, and comparatively little elevated. The
last tubercula- tooth sul)(|uadrate, nearly as large as the preceding, and its
greater axis directed obliiiuclj backwards with four or rather six distinct
elevated points; but the outer raised margin, which is so conspicuous in
the European Otter, appears to be indistinct or simply elevated into two
pointed tubercles, or wanting entirely, in the American."
In age, tlie canine as well as tlie anterior molars becDme much worn.
In a specimen from Carolina, the incisors are worn down to the upjjcr
surface of the jaw teeth; in another from. Georgia, all tlie teeth are worn
down to the gums. A specimen from Canada and another from Texas
have the teeth very j)ointed, and the canine projecting beyond the lips.
These were evidently younger animals. In older specimens we liave on
.several occasions found the two anterior jaw teeth entirely wanting, as
well as some of the incisors, the former appearing to have dropped out at
COLOUR.
A specimen from Lower Canada. Moustaches very Hght brown, mnnv
being white, those on the sides of the face diiiiry white ; up|)er lip anil
chin light grayish brown, a shade darker under the throat ; the long hairs
covering the fur are in one half of their length from their roots (liiit;v
white, gradually deepening into brown. The general colour on the
upper surface is that of a rich dark chcsnut brown, a shade lightcT
on the whole of tlie under surfnce. Richardson states: "The Can.ida
Otter may be distinguisiied from the European species by the fur of
its belly being of the same shining brown colour with that of the
back." In this particular our obscM-vations do not correspond with
those of our distinguished friend. Out of more than a hundriul speci-
mens of American Otters which wc have examined, many of which ca
me
wm
>
4 "ANA DA OTTER.
trom Canada and the Rocky Mr.iinfains, we have but with one or two ex
ceptions found the colour on the under surface lighter than on the back.
A specimen from Caroiiim, an old male, teeth much worn.
Upper lip from the nostrils, chin and throat to near the chest, -rayish
whife ; the fur on the back, although tiot quite so long as that of snec i-
mens fron. Canada, is (,uitf, dense and silky, and very nearly equal in 'fine-
ness. It is whitish at the roots, with a bluish tinge lowards the extremities
The longer hairs which conceal the fur and present the external colouring
are very nearly of the same tint as in those procured in Canada, so that
the specimens from these widely separated localities can scarcely be re-
garded even as varieties.
A specimen from Colorado, Te: :..^.
(Tl.e form 's, precisely similar to the Otters of Canada anJ those existing
:n various intermediate States. The palms are naked, with a little less
uair between the toes on the upper and under surlaces.) The colour is
throughout two shades lighter than that of specimens from Cana-la. but
the markings are similarly distributed. Fur on the back from the roots
soiled white, inclining .o brown at the tips. The long and rigid hairs on
the upper surface lightish brown at the roots, then dark brown, tipped with
lightish brown.
DIMENSIONS.
From point of nose to root of tail,
Tail,
From point of nose to eye, -
From point of nose to ear,
Height of ear, - - . .
Specimen from Carolina.
From point of nose to root of tail.
Tail,
Point of nose to eye, - . . .
" to ear, - . . .
Height of ear,
Weight, 23 lbs.
»eet.
incnes
2
5
!
7
11
4
Of
01
2
7
1
5
1|
3?
Of
"1
PMt
InohM.
2
7
1
(t
u
3?
3J.
10
1
n
1
H
Specimen frum the Colorado, in Texas.
From nose to root of aiil,
Leny:th of fail,
From p. iiit oliiose to eye,
to ear, - - - . .
Between the ears, ---...
Height,
Aroiiiul th<- body beliind the shoulder,
Around the body, (middle,)
Weight 20 lbs.
^Ye concludecl our first voltm.e svi.h a brief account of Sprrmo,.,,;/„s
liuhordsonn, the last animal figured in plates I to .".u inHusive of our
Illustrations of the Quad u,,eds of North A.neriea. Jl.vin.^ si,,;,, th-.t
volume was written, published about 00 more plates, wo nou'^.k/u,. ,.,u-
pen to portray the habits and describe ,h. forms and colours of tl e specie,
figured .a p ates .51 to 100 inclusive, and shall, we hope, be able to
give our readers tolerably goo.l accounts of them; aWhough, alas- the
days o, 0U-. youth are gone, when, full of enthusi.-.sn, and anxious to
exa,nu.e every ob,ect m nature within our .-eaeh. the rising sun never
found us slumbenng away the f^esh hours of the morning but beamed
upon our path through the deep forest, or lighted up to ^ ndTa^^^
ness the hd. s.de or mountain top, which we had alrea.ly gainH ,
quest of the birds or the beasts that were to be met with; an L
we often prolonged our rambles until the shades of even ni tZ
us yet at a distance from our cau.p, ,„.ded with wild turC du
geese, and perchance an Otter. turKcjs, ducks,
Fresh and pleasant in our mind i^ the recollection of our earlv exne
tzr^rT^'^^r' ^'""^^^^ -visited shor.:::;!::
country , and although more than forty years of varied r.nd busv l.T. K
passed since the Otter was shot and dr.-'.wn, whose -"1' '"
^ Will try to t^. you wi.h us to a spot o-i' the ^^^ Z^^^Z^l
Omo It .s a cod .vmtry morning : the earth concealed bv a slight <.,
«ng of snow, and the landscape in all its ori^^innl wildness IT .
•impid charact-^r and h....^ " '"''^^'"^•r clear and
, y*- see a ciai k ohjcrf making its way
>
cowards the spot on which we stand, through the swiftly dividing ele
ment. It has not observed us : we remain perfectly still, and presently
It IS distinctly visible ; it is an Otter, and now witluii the ran-o ot our old
rm "T.'ar Jacket," we take but one moment to raise our piece and fire ;
ti.e water is agitated by a violent convulsive movement of the animal
our dog plunges into the river, and swimming eagerly to the Otter, seizes
It, bui the latter dives, dragging the dog with it beneath the surface
and when they reappear, the Otter has caught the dog by the nose and
Js struggling violently. The brave dog, however, does not give up but
in a few moments drags the wounded Otter to the shore, and we imme-
diately despatch it. Being anxious to figure the animal, we smooth its
disordered fur and proceed homewards with it, where, although at that
time we had not drawn many quadrupeds, we soon select a position ir
which to figure the Otter, and accordi.igly draw it with one Ibot in a
steel-trap, and endeavour to represent the pain and terror felt bv the
creature when its foot is caught by the sharp saw-like teeth of the tr'ap.
.,^"t^?:''*!:r'^*' town of Henderson, (Kentucky), but on the opposite
sue of the Olno river, in the State of Indiana, there is a pon.l nearly one
mile in length, with a depth of water varying from twelve to fifteen feet.
Its shores are thickly lined with cane, and on the edge of the water stand
many large and lofty cypress trees. We often used to seat ourselves on a
lallen trunk, and watch in this secluded spot the actions of the birds .nd
animals which resorted to it, and here we several times observed Otters
engaged in catching fishes and d.-vouring them. When pursuing a fish
they dn-ed expertly and occasionally remained for more than a minute'
below th, surface. They generally held their prey when they came to the
opofthewater,bythe head, and almost invariably swatn with it to a
half-sunken log. or to the margin of the pond, to eat the fish at their ease
havn.g dotie which, they returned agai.i to the deep water to obtain'
more.
One mornhigwe observed that sotne of these animals resorted to the
neighbourhood of the root of a large tree which stood o.i the side of the
pond opposite to us, and with its overhanging branches shaded the water
After a at.gumg walk through the tanghd cane-brake and thick under-
yoodwluch bordered the sides of this lonely place, we reached the oppo-
te SHleofthe pond near the large tree, a.ul u.oved cautiouslv thr 'u' ^l.
the mud and water towards its roots: but th. hoMring or si-^ht of ,)„.
Otters was attracted to us, and we saw several ..Itlu.n. hastily^make ojf
at our approach. On sounding the free with the but. of onr gun we d^-
covered that it was hollow, and then having placed a large stick in a
slanting position against the trunk, mc succeeded in reaehin.. the lowest
-?!-»-
lividing ele
nd presently
ro of our old
cc and fire ;
the animal,
Otter, seizes
he surCace,
le nose and
ive up, but
I we imme-
i smooth its
igh at that
position in
* loot in a
felt by the
the trap.
10 opposite
nearly one
lifteen feet,
rater stand
selves on a
i birds uiid
•ved Otters
nine; a fish,
a minute
ame to the
ith it to a
their ease,
to obtain
rted to the
^ide of ihc
the water,
ick under-
the oppo-
ly thrnii^iJi
inlit of ili(>
make oJf
11, we d'v-
■iliek in ,i
he lowest
7
t)ough, and thence climbed up to a broken branch from which an aperture
into the upper part of the hollow enabled us to examine the interior. At
the bottom there was quite a large space or chamber to which the Otters
retired, but whether for security or to sleep we could not decide
Next morning we returned to the spot, accompanied by one of our
neighbours, and having approached, and stopped uo the entrance under
water as noiselessly as possible, we cut a hole in the side of the tree four
or hve feet from the ground, and as soon as it was large enough to admit
onr heads, we peeped in and discovered three Otters on a sort of bet'
composed of the inner bark of trees and other soft substances such .s
water grasses. We continued cutting the hole we had made, larger and
when sufficiently widened, took some green saplings, split them at the
I'ut-end, and managed to fix the head of each animal firmly to the
ground by passing one of these split pieces over his neck, and then press-
ing the stick forcibly downwards. Our companion then crept into the
hollow, and soon killed the Otters, with which we returned home
The American Otter frequents running streams, large ponds, and more
.sparingly the shores of some of our great lakes. It prefers those waters
which are clear, and makes a hole or burrow in the banks, the entrance
to which is under water.
This species has a singular habit of sliding off the wet slopin- banks
into the water, and the trappers take advantage of this habit to ca'tch the
an.mal by placing a steel-trap near the bottom of their sliding place. -.
that the Otters occasionally put their foot into it as they are swiftly
gliding toward the water. ^
In Carolina, a very common mode of capturing the Otter is by tyinc^ a
pretty large fish on the pan of a steel-trap, which is sunk in the w^ter
where It is Irom five to ten feet deep. The Otter dives to the bottom to
seize the f.sh is caught either by the nose or foot, and is generally
lound drowned. At other times the trap is set under the water without
bau, on a log, one end of which projects into the water, whilst he othe
rest on he banks of a pond or river ; the Otter, in endeavouring to moun
the log, IS caught in the trap.
_ Mr. GcoMAN, in his account of these singular quadrupeds, states that
their avounte sport is sliding, and for this purpose in winter the hi-H.esL
ndge ot snow .s selected, to the top of which the Otters scramble, where
lying on the beily wi,h the fore-feet bent backwards, they giv them.'
-H- an nn,.lsewi,h .heir hind legs aiK. swi.ly glide he'l-fbreZt
<.oxvn tiu. decl.vi.y, sometimes for the distance of twenty yards This
spor they continue apparently with the keenest enjoyment until fatigue
or hunger induces them to desist." '"."Bue
Tf-
This statement is confirmed by Cartwright. Hearne, Richardbon, and
more recent writers who have given the history of this species, and is in
accordance with our own personal observations.
The Otters ascend the bank at a place suitable for their diversion, and
sometimes where it is very steep, so that they are obliged to make quite an
effort to gain the top ; they slide down in rapid succession where there arc
many at a sliding place. On one occasion we were resting ourself on the
bank of Canoe Creek, a small stream near Henderson, which empties
into the Ohio, when a pair of Otters made their appearance, and not
observing our proximity, began to enjoy their sliding pastime. They
glided down the soap-like muddy surface of the slide with the rapidity of
an arrow from a bow, and we counted each one making twenty-two
slides before we disturbed their sportive occupation.
This habil of the Otter of sliding down from elevated places to the
borders of streams, is not confined to cold countries, or to slides on the
snow or ice, but is pursued in the Southern States, where the earth is
seldom covered with snow% or the waters frozen over. Along the reserve-
dams of the rice fields of Carolina and Georgia, these slides are very
common. From the fact that this occurs in most cases during winter,
about the period of the rutting season, we are inclined to the belief that
this propensity may be traced to those instincts which lead the sexes to
their periodica! associations.
Richardson says that this species has the habit of travelling to a great
distance through the snow in search of some rapid that has resisted the
severity of the winter frosts, and that if seen and pursued by hunters on
these journeys, it will throw itself forward on its belly and slide through
the snow for several yards, leaving a deep furrow behind it, which move-
ment is repeated with so much rapidity, that even a swift runner on snow
shoes has some difficulty in overtaking it. He also remarks that it dou-
bles on its track with much cunning, and dives under the snow to elude
its pursuers.
The Otter is a very expert swimmer, and can overtake almost any fish,
and as it is a voracious animal, it doubtless destroys a great number of
fresh water fishes annually. We are not aware of its having a preference
for any particular species, although it is highly probable that it hits.
About twenty-five years ago we went early one autumnal morning to
study the habits of the Otter at Gordon and Spring's Ferry, on the Cooper
River, six miles abovi; Charleston, where they were represented as being
quite al)undant. They came down with the receding tide in groups or
families of five or six together. In the space of two hours we counted
forty-six. They soon separated, ascended the diflerent creeks in tiie salt
ARD80N, and
;s, and is in
version, and
ikc quite an
■re there are
rself on the
ich empties
3e, and not
me. They
rapidity of
twenty-two
aces to the
ides on the
the earth is
the reserve-
es are very
ing winter,
belief that
he sexes to
? to a great
resisted the
hunters on
ide through
'hich move-
ler on snow
that it dou-
o\v to elude
ost any fish,
number of
I prolerenee
hat it hiis.
morning to
the Cooper
ed as being
1 groups or
ve counted
in liie salt
9
marshes, and engaged in capturing mullets (Mugrl). In most cases they
carne to the bank with a fish in their mouth, despatching it in a minute,
and then hastened again after more prey. They returned up the river to
.heir more secure retreats with the rising tide. In the small lakesand
ponds of the mterior of Carolina, there is found a favourite fish with the Ot-
ter, called the fresh-water trout {Gn/stes sahmides
Although the food ofthe Otter in genera! is fish, yet when hard pres d
by hunger, it will not reject animal food of any kind. Those we had in
confinement, when no fish could be obtained were fed on beef, which
they always preferred boiled. During the last winter we ascertained
that the skeleton and feathers of a wild duck were taken from an Otter',
nest on the banks of a rice field reserve-dam. It was conjectured that
the duck had either been killed or wounded by the hunters, and ua. in
this state seized by the Otter. This species can be kept in confinement
easily m a pond surrounded by a proper fence where a good supply of fish
is procurable.
On throwing some live fishes into a small pond in the Zoological
Gardens m London, where an Otter was kept alive, it immediately
plunged off- the bank after them, and soon securing one, rose to the sui--
face holding its prize in its teeth, and ascending the bank, rapidly ate it
by large mouthfuls, and dived into the water again for another This it
repeated until it had caught and eaten all the fish which had been thrown
mlo the water for its use. When thus engaged in devouring the luckless
fishes the Otter bit through them, crushing the bones, which we could hear
snapping under the pressure of its powerful jaws.
When an Otter is .shot and killed in the water, it sinks from the wei-ht
of Its skeleton, the bones being nearly solid and therefore heavy, and the
hunter consequently is apt to lose the game if the water be deep ■ this
annn.al is, however, usually caught in strong steel-traps placed and baited
in Its haunts ; if caught by one of the fore-feet, it will sometimes gnaw
the foot off, in order to make its escape.
Otters when caught young are easily tamed, and althou-h their gait is
ungainly, will follow their owner about, and at times are quite plavful
We have on two occasions domesticated the Otter. The individuals 'had
been captured when quite young, and in the space of two or threo davs
necame as tame and gentle as the young of the domestic do-^ Thin-
preferred mil'.: and boiled corn meal, and refused to eat fish or^ meat of
any kind, until they were several months old. They became so attached
to us that at the moment of their entrance into our studv they commenced
crawling into our lafv-mounting our table, romping am'ong our books and
VOL. II. — 2
;^ ^ ,
10
writing materials, and not unlrequently upsetting our ink-stano and de-
ranging our papers.
The American Otter has one litter annually, and the young, usually
two and occasionally three in number, are brought forth aijout the mid-
dle of April, according to Dr. Kuiiardson, in high northern latitudes. In
the Middle and Southern States they are about a month earlier, and
probably litter in Texas and Mexico about the end of February.
The nest, in which the Otter spends a great portion of the day and in
which the young are deposited, we have had opportunities of exam-
ining on several occasions. One we observed in an excavation three leet
in diameter, in the bank of a rice field ; one in the hollow of a fallen tree,
and a third under the root of a cypress, on the banks of Cooper river, in
South Carolina ; the materials— slicks, grasses and leaves— were abun-
dant ; the nest was large, in all cases protected from the rains, and above
and beyond fhe influence of high water or freshets.
J. W. Audubon procured a fine specimen of the Otter, near Lagrange
in Texas, on the twenty-third of February, 1810. It was shot whilst play-
ing or sporting in apiece of swampy and partially flooded ground, about
sunset, — its dimensions we have already given.
Early writers have told us that the common Otter of Europe had long
been taught to catch fish tor its owners, and that in the houses of the
great in Sweden, these animals were kept lor thnt purpose, and would go
out at a signal from the cook, catch fish ^nd bring it into the kitchen in
order to be dressed for dinner.
This, however improbable it may at first appear, is by no means un-
likely, except that we doubt the fact of the animal's going by itself for
the fish.
Bewick relates some anecdotes of Otters which captured salmon and
other fish for their owners, for particulars of which we must refer our
Our late relative and friend, N. Bertiioud, Esq., of St. Louis, told us
some time since, that while travelling through the interior of the State
of Ohio, he stopped at a house where the landlord had four Otters alive
which were so jrentle that they never fnilod to come when he whistled
for them, and that when they approached their master they crawled
along slowly and with much apparent humility towards him, and looked
somewhat like enormous thick and short snakes.
GEOGRAPIMCAI, DISTRinUTIOV.
The geographical range of this species includes almost the whole con
11
na and de-
ig, usually
at the mid-
it udes. In
arlier, and
y-
day and in
1 of exam-
1 three feet
falhm tree,
er river, in
.vere abun-
and above
Lagrange
.'hilst play-
i?es of the
I would go
kitchen in
means un-
y itself for
ilmon and
t refer our
is, told us
the State
tters alive
B whistled
f crawled
nd looked
hole con
tineni of North America, and possibly a portion of South America. It
has, however, been nearly extirpated in our Atlantic States east of
Maryland, and is no longer found abundantly in many parts of the
country in which it formerly was numerously distributed.
It is now procured most readily, in the western portions of the Uni-
ted States and on the Eastern shore of Maryland. It is still abundant
on the rivers and the reserve-dams of the rice fields of Carolina, and
is not rare in Georgia, Louisiana and Texas.
A considerable number are also annually obtamed in the British pro-
vinces. We did not capture any Otters during our journey up the
Missouri to the Yellow Stone River, but observed traces of them in the
small water courses in that direction.
GENERAL REMARKS.
Much perplexity exists in regard to the number of species of American
Otters, and consequently in determining their nomenclature. Ray, in
1()!>3, described a specimen from Brazil under the name of Braziliensis.
It was subsequently noticed by Brisson, Blumexbach, D'azara, Marcorave,
ScriREBER, SiiAW, and others. We have not had an opportunity of com-
paring our North American species with any specimen obtained from
Brazil. The loose and unscientific descriptions ve have met with of the
Brazilian Otter, do not agree in several particulars with any variety of
the species found in North America ; there is, however, a general resem-
blance in size and colour. Should it hereafter be ascertained by closer
investigations that the species existing in these widely removed localities
are mere varieties, then the previous name of Braziliensis (Rav) must be
substituted for that of L. Canadensis, Fr. Cuvier.
In addition to the yet undecided species of Ray, Fp. Cuvier has sepa-
rated the Canada from the Carolina species, bestowing on the former the
name of L. Canadensis, and on the latter that of L. Lafa.vina. Gray has
published a specimen from the more northern jmrtions of North America
mider the name Lataxina Mollis ; and a specimen which we obtained in
Carolina, and presented to our friend .Air. Watrrhouse of London, was, we
Notwithstanding these high authorities, we confess we have not heon
able to regard them in any other li-ht than varieties, some more strongly
marked tlian others, of the same species. The /.. Lataxina of Fr. Cuvier,
characters as to .justify us in separating the species from each other or from
TT
12
of Z. Canadensis, (Fauna Boreali Americana,) was that of a large animal,
and the Mollis of Gray was, we think, a tine si)eciinen of the Canada
Otter, with fur of a particular soilness. Wc have, after much deliberation,
come to the conclusion that ail these must he regarded as varieties of one!
species. In dentition, in general form, in markings and in habits, they are
very similar. The specimen from Texas, on account of its lighter colour
and somewhat coarser fur, differs most from the other varieties ; but it does
not on the whole present greater differences than are often seen in the
common mink of the salt marshes of Carolina, when compared with speci-
mens obtained from the streams and ponds in the interior of the Middle
States. Indeed, in colour it much resembles the rusty brown of the Caro-
lina mink. In the many specimens we have examined, we have disco-
vered shades of difference in colour as well as in the pelage among indivi-
duals obtained from the same neighbourhood. In many individuals which
were obtained from the South and North, in localities removed a thousand
miles from each other, we could not discover that they were even varieties.
In other cases these differences may be accounted for from the known effects
of climate on other nearly allied species, as evidenced in the common mink.
On the whole we may observe, that the Otters of the North areof a darker
colour and have the fur longer and more dense than (hose of the South. As
we proceed southward the hair gradunlly becomes a little lighter in colour
and the fur less dense, shorter, and coarser. These changes, however, are
not peculiar to the Otter. They are not only observed in the mink, but in
the raccoon, the common American rabbit, the Virginian deer, and nearly
all the species that exist both in the northern and southern portions of our
continent.
We shall give a figure of L. Mollis of Gbay, in our third volume.
13
VULPES VELOX.— Say.
Swift Fox. Kit Fox.
PLATE LII,— Male.
V. gracilis, supra cano fulvaque varices, infra albus ; v. fnlvo in^ior.
CHARACTERS.
Smaller than the American red fox, body slender, gray above, varied with
fulvous; beneath, white.
SYNONYMES.
Kit Fox, or small burrowing fox of the plains. Lewis and Clark, vol. i. p 400
Vol. iii., pp. 28. 29. *^
Canis Vklo.\, Say. Long's Expedition, vol. ii., p. 330.
" " Harlan's Fauna, 91.
" Godman's Nat. Hist., vol. i., p. 282.
Canis Cinereo Aroentatl-s, Sabine, Franklin's Journey, p. 058.
" (vulpes) Cinereo Aroentatus, Richardson, Fa. B. Ame. p. 98.
DESCRIPTION.
This little species of Fox bears a great resemblance to our American
red fox, in shape, but has a broader face and shorter nose than the latter
species ; in colour it approaches nearer to the gray fox. Its form is h^nt
and slender, and gives indication of a considerable capacity for sp-ed ; the
tail is long, cylindrical, bushy, and taperinp; at the end.
The entire length from the insertion of the .superior inci.sors to the tip of
the occipital crest, is rather more than four inches and three-tenths- the
lea,st distance between the orbital cavities rine-tenths of an inch ; between
the insertion of the lateral muscles at the junction of the frontal and pi
rietal bones, half an inch. The greatest breadth of this space on the
parietal bones, thirteen-twentieths of an inch."— (Say.) The hair is of
two kinds, a soft dense and rather woolly fur beneath, intermixed with
longer and stronger hairs.
COLOUR.
The fur on the back, when the hairs are separately examined, Is from
^
14
SWIFT FOX.
the roots, for three-fourlTis of its length, of a light hrownish gray colour,
then yellowish brown, then a narrow rin^ of hhu-k, then a hir-er rin?
of pure white, siijihtiy tii)pe(l at (he apical part with hlaelv. Tl,.. up[M-r
part of the nose is pale yellowish brown, on each sid,, of whi.l. ihcre
is a patch of brownish, givin- It a hoary appearance in consequence of
some of the h.-.irs being tipped wilh white; mouslncjies black; „pp,,p
lij) margined by a stripe of while hairs. There is a narrow blackish
brown line between the white of the posterior angle of the mouth, which
is prolonged around the margin of the lower lip. The upper j)art of
the head, the orbits of the eyes, the cheeks and superior surface of tne
neck, back, and hips, covered with intermixed hairs, tipped with brown,
black, and white, giving those parts a grizzled colour. Towards the pos-
terior parts of the back there are many lon<r hairs interspersed, th.ac
are black from the roots to the tip. The .'^ides of the neck, the cnesi.
the shoulders and flanks, are of a didl reddish orange colour; the lower
jaw is white, wilh a tinge of blackish brown on its margins; the throat
belly, inner surface of legs, aad upper surface of feet, are white. The
outside of the forelegs, and the posterior parts of the hindlegs, are brown-
ish orange. The slight hairs between the callosities of the toes are
brownish. The tail is on the under surface yellowish gray with a mix-
ture of black, and a few white hairs ; the under surlkce is brownish
yellow and black at the end.
DIMENSIONS.
From point of nose to root of tail, - . .
Tail, (vertebrfP,)
" to end of hair,
From tip of nose to end of head,
Between the eyes,
Weight 8i lbs.
Measurement of a young animal killed at Fort Union.
From point of nose to root of tail,
Tail, (vertebrre,)
" to end of hair, ---.,.
Width at the shoulders,
Length of head, . - . . .
Between the eyes, ... , .
Breadth between the ears, - - . . .
Feet.
Inchflk.
1
8
9f
1
21
H
n
a?
1
4|
5}
Of
1|
1 gray colour,
I hu-'^er ring
Tlif upficr
wliicli |licr(>
nsc'({ii('iice of
lack ; upper
'ow hlackisli
iioutli, wliicli
|)pcr part of
irl'acf of tne
with brown,
ards llio po.s-
s|)crsc(l, tliac
ik. the cnesi,
I" ; fiK' lower
; the throat,
white. Tile
, are brown-
lie toes are
with a mix-
is brownish
SWIFT FOX.
HABITS.
15
Inchak.
8
9|
21
H
2?
If
Tlie First Swift Fox we ever saw alive was at Fort Clark on the upper
Missouri riv;'r, at whieh place we arrived on the 7th of June, 18i;j. |t
had been cauj,'ht in a steel-trap by one of its fore-leet, and beh.nired 1o Mr.
CiiARnoN, the principal at the Fort, who with great kindness an.l politeness
presented it to us ; assuring us that good care would be taken of it during
our abs,M,ce, (as we were then ascending the river to proceed to the base
of the Kocky Mountains,) and that on our return to th« Mandan village,
we might easily take it with us to New- York.
Mr. Charuon informed us that this Fox was a most expert rat catcher
and that it had been kept in a loft without any other food than the rats'
and mice that it caugl t there. It was a beautiful ani.nal, and ran will,-
great rapidity from one side of the loft to anoth.M-, to avoid us. On our
approaching, it showed its teeth and growled much like the conunon red
fox.
Soon after we left Fort Clark, between the western shore of the Mis-
souri river and the hills called the " Trols mamelles" by the Canadian and
French trappers, on an open prairie, we saw the second Swift Fox we met
with on this Journey. Our party had been shooting several bulfaloes and
our tnend En. H.ku.s, Esq., and ourself, were approaching the hu'n-ers
apace. We were on foot, and Mr. H.rh.s was mou.ited on his buffalo
horse, when a Swift Fox darted from a concealed hole in the prairie almost
under the hoofs of my friend's steed. My gun was unfortunately loaded
wPh ball but the Fox was chased by Mr. Harris, who tookaimat i, seve-
ral t.mes but could not draw sight on the animal ; and the cunning fellow
doubled and turned about and around in such a <lexterous mann.M- that it
hnally escaped in a neighbouring ravine, and we suppose gained 'its bur.
row, or s eltered itself in the cleft of a rock, as we did not see it start r 'Z
1 his shght adventure with this (so called) Swift Fox convinced us thj the
accounts of the wonderful speed of this animal are considerablv exalgo-
• ated ; and were we not disposed to retain its name a.s given bv^Mr Stv
we should select that ot Prairie Fox as being most appropriate for i M '
Harris, mounted on an Indian horse, had no difficulty in keeping up wUh
n and overrunning It, which caused it to double as Just men tione.l. H .
our guns been loaded with buck shot we should no doubt have k lie
is ne-psary to say, perhaps, that all the authors who have written abou;
us .X most of whom appear to have copied Mr. Sav'.s accou no i ) .
sert hat its extraordmary swiftness is one of the most remarkable char e
tensticsoftheanimal Gooma. observes that the fleetest antX or l;;
^
16
SWIFT FOX.
when running at full speed, is passed by this little Fox with the greatest
ease, and such is the celerity of its motion, that it is compared by the cele-
brated travellers above quoted, Lewis and Clark and Mr. S.w, ""to the
flight of a bird along the ground rather than the course of a (juadruped."
There is nothing in the conformation of this species, anatomically
viewed, indicating extraordinary speed. On the contrary, when we com-
pare it with the red fox or even the gray, we (ind its body and legs
shorter iu proportion than in those .species, and its large head and
bushy tail give it rather a more heavy appearance than either of the
foxes just named.
Dr. Richardson inform-s us that the Saskachewan river is the most
northern limit of the rr.ngc or the Kit Fox. Its burrows he snys are
very deep and excavated in the open plains, at some distance I'rom the
woody count rv. Lewis and Clark describe it as being extremely vigi-
lant, ajid say that it betakes itself on the slightest alarm to its burrow.
On our return to Fort Union after an excursion through a part of the
adjacent country, we found at some distance from the stockade a young
Swift Fox whicli we probably might easily have captured alive; but
fearing that its burrow was near at hand, and that it would .soon reach
it and rvade our pursuit, Mr. HarrIs shot it. This was the last speci-
men of this Fox that we were p))le to observe during our journey ; we
have given its measureme-^ in a .'"ornr.- part of this article. On our re-
turn voyage, we found on arriving at Fort Clark that the living Swift
Fox given us by Mr. Ciiardon was in excellent condition. It was placed in a
strong wooden box lined in part with tin. and lor greater security against
its escape, had a chain fastened to a collar around its neck. Ihiring
)ur homeward journey it was fed on birds, squirrels, and the flesh oi
other animals, and finally safely reached our residence, near New-York
where it was placed in a large cage box two-thirds sunk beneaih the
surface of the ground, completely tinned inside, and half tilled with earth.
When thus allowed a comparatively large space and plenty of earth to
burrow in, the Fox immediately began to make his way into ihe loose
ground, and soon had dug a hole large enough to conceal himself entirelv.
While in this commodious prison he fed regularly and ate any kind of IVesh
meat, growing fatter every day. He drank more water than foxes gene-
rally do, seemed anxious to play or wash in the cup which held his supply,
and would frequently turn it over, spilling the water on the floor of the
cage.
The cross fox which we described in oui first volume does not appe.ar tc
require water, during the winter months at least, when fed on fresh meat .
as one that we have had in confinement during the past winter would not
SWIFT FOX.
1 the greatest
I by the cele-
Say, "to the
[inalomically
leii we com-
)dy and legs
ither of" the
is the most
he s.'iys are
loe from the
rcmely vigi-
I its burrow.
part of tlie
ide a young
'. alive; but
I soon reach
' last speci-
ourncy ; we
On our re-
living Swift
s placed in a
jrity against
■k. During
the flesh of
New-York,
beneaih the
with earth,
of earth to
() ihe loose
^elf entirely,
cind of fresh
foxes gene-
l his supply,
floor of the
IT
"J
drink any, and was not supplied with it for two or three monttis. Proba-
bly in a wild state all predatory animals drink more than when in con-
finement, for they are compelled to take so much exercise in the pursuit
of their prey, that the evaporation of fluids, by perspiration, must w on
rapidly; besides which, they would probably often try to appease the
cravings ofhunger by drinking freely, when unabie to procure sufficient
food.
aEOGRAPIIICAL DISTRIBUTION.
The Swift Fox appears to l)e found on the plains of the Columbia river
valley, as well as the open country of the region in which it has generally
been observed, the extensive prairies of the eastern side of the Rocky
Mountains.
It does not appear to be an inhabitant of New Mexico, Texas or Cali-
fornia, as far as our information on the subject extends.
GENERAL REMARKS.
Our esteemed friend. Sir John Ric.iARnsoN, (Fauna Boreali Americana,
p. 98,) has supposed that SciiREiiER's description of Cams cinerco argen.
tatus, applied to this species, and hence adopted his specific name, to*the
exclusion of Sav's name of C. Vclox. In our first volume, (p. 172,) we
explained our views on this subject. In the descriptions of C. Virginianiis
of ScHREBER, and C. Argenleus, Erx., they evidently described mere varie-
ties of the gray (ox, (F. Virginianvs) ; we have consequently restored
Say's specific name, and awarded to him the credit of having been the
first scientific describer of this animal.
)r appe^ir tc
fresh meat ,
r would not
voh. II. — 3.
^
Id
MEPHITIS MESOLEUCA.— Light.
Texan Skunk.
PLATE LIII.-MAtE.
M. Vitfa solitaria media antice (in verticr> rotundata, icque lata ad
basin caudae usque continuata, hac fota alba.
CHARACTERS.
The whole hack, from the forehead to the tail, and the tail, white ;
not covered ivith hair.
noxp
SyNONYMES.
Mephitis Me80leuca, Lichtenstein. Darstellung neuer oder wenig bekannter Sau-
gethiere. Berlin, 1827, 18.34. Tab. 44, Fig. 2.
Mephitis Nasuta, Bennett. Proceedings of the Zoological Societv, 18.S.1. p. 89
M. Mksoleuca, Licht. Ueber die Quttung Mephitis. Berlin, 18.38, p. 23.
DESCRIPTION.
In form, this species bears a considerable resemblance to the common
Am-rican skunk, {Mrphifis chhiga.) Like all the other species of skunl:
this animal has a broad and fleshy body ; it is wider at the hips than at
the shoulders, and when walking, the head is carried near the gmnnd
whilst the back is obliquely raised six or seven inches higher; it stands
low on its legs, and progresses rather slowly. Forehea.l, slisrhlly rounded ■
eyes, small ; ear.s, short and rounded ; hair, coarse and Ion- ; 'under fur'
sparse, won!!y, ai.d not very fine; tail, of moderate len-th and bushy;'
nose, for thre^-lburths of an inch above the snout, naked. This is a char-
a/;feristic rr,u. k, by -.vL-ch it may always be distinguished from the common
American skunk, the latter being covered with short hair to the snout.
Palms naked.
COLOUR.
The whole of the long hair, including the under fur on the back, and the
tail on both surfaces, is white. This broad stripe commences on the fore-
head about two inches from the point of the nose, running near th^ ears,
white; nose
kannter Sftii-
83.1, p. 89.
). 23.
^he common
^s of skuRl;.
lips than at
the gr'iini(j^
' ; it stands
ly rounded ;
under fur,
md bushy ;
s is a char-
he common
) the suout.
ck, and the
<n the fore-
r th'^ ears,
i
j
^,
TEXAN SKONK.
19
and in a straigni line along the sides and over the haunches, taking in the
whole of'the tail. The nails are white ; the whole of the under surface of
the body black, with here and there a white hair interspersed. On the
forefeet around the palms and on the edges of the under surface, there are
coarse whitish hairs.
The peculiarities in the colour of this species appear to be very uniform,
as the specimens we examined in the Berlin Museum and in the collection
of the Zoological Society in London, corresponded precisely with the speci-
men from which this description has be.'- made.
Ft. iDchea.
1
41
7
11
3
ov.
8*
5
DIMENSIONS.
From point of nose to root of tail, ...
Tail (vertebra-),
Do. to end of hair,
Height of ear,
Length of heel to longest claw, ....
Breadth of white stripe on the middle of the back,
Weight, 5 lbs.
HABITS.
This odoriferous animal is found in T^-as and Mexico, and is very sim-
ilar in its habits to the common skunk of the Eastern, Middle and South-
western States. A specimen procured by J. W. Audubon, who travelled
through a portion of the State of Texas in 1845 and 6, for the purpose ol
obtaining a knowledge of the quadrupeds of that country, was caught alive
in the neighbourhood of the San Jacinto ; it was secured to the pack saddle
of one of his baggage mules, but managed in some way to escape during
the day's march, and as the scent was still strong on the saddle, it was not
missed until the party arrived at the rancho of Mr. McFadden, who kept
u house of entertainment for man and beast, which by this time was greatly
needed by the travellers,
The almost endless varieties of the Mephitis chinga, the common skunk,
many of which have been described as distinct species by naturalists, have,
from our knowledge of their curious yet not specific difierences, led us to
admit any new species with doubt ; but from the peculiar characteristics
of this animal, there can be no hesitation in awarding to Prof. Lichtenstein
the honour of having given to the world the first knowledge of this inter-
The Mephitis Mesoleuca is found on the brown, broomv sed«"/ nl.ainp, a^
20
TEXAN SKUNK
well as in the woods, and the cultivated districts of Texas and Mexico
Its food consists in part of grubs, beetles, and other insects, and occa-
sionally a small quadruped or bird, the eggs of birds, and in fact every-
thing which this carnivorous but timid animal can appropriate to its
sustenance.
The retreats of this SUunk are hollows in the roots of trees or fallen
trunks, cavities under rocks, &c. ; and it is, like the northern species, easily
caught when seen, (if any one has the resolution to venture on the experi-
ment,) as it will not endeavour to escape unless it be very near its hiding
place, in which case it will avoid its pursuer by retreating into its burrow,
and there remaining for some time motionless, if not annoyed by a dog, or
by digging after it.
The stomach of the specimen from which our drawing was made, con-
tained a number of worms, in some degree resembling the tape worm, at
times found in th* human subject. Notwithstanding this circumstance,
the individual app<ared to be healthy and was fat. The rainy season
having set in (or at least the weather being invariably stoiniy for some
time) after it was killed, it became necessary to dry its skin in a chimney.
When first taken, the white streak along the back was as pure and free
from any stain or tinge of darkness, or soiled colour as new fallen snow.
The two glands containing the fetid matter, discharged from lime to time
by the animal for its defence, somewhat resembled in appearance a
soft egg.
This species apparently takes the place of the common American skunk,
{Mephitis cMnga,) in the vicinity of the ranchos and plantations of the
Mexicans, and is quite as destructive to poultry, eggs, &c., as its northern
relative. We have not ascertained anything about its season of breedin",
or the time the female goes with young : we have no doubt, however, that
in these characteristics it resembles the other and closely allied species.
The long and beautiful tail of this Skunk makes it conspicuous amon"
the thickets or in the musquit bushes of Texas, and it most frequently
keeps this part elevated so that in high grass or weeds it is first seen by
the hunters who may be looking for the animal in such places.
GEOGRAPHICAL DISTRIBUTION.
The Mephitis Mesoleuca is not met with in any portion of the United
States eastward and northward of Texas. It is found in the latter State
and in most parts of Mexico. We have, however, not seen any skunk from
South America which corresponds with it.
''^Sl' -'^'- . * ^ ^ ' "H
TEXAN SKUNK,
21
GENERAL REMARKS.
Naturalists have been somewhat at a loss to decide on the name by
which this species should be designated, and to what author the credit is
due of having been the first describer.
The specimens obtained by Liciitenstein were procured by Mr. Deppe,
in the vicinity of Chico, in Mexico, in 1825, and deposited in the museum
to 1834, this species with many others was first published. In 1833, Ben-
nett published in the proceedings of the Zoological Society, the same spe-
cies under tht: name of M. Nastita. The papers of Lichtenstein, although
printed and circulated at Berlin, were not reprinted and collected into a
volume till 1834. Having seen the original papers as well as the speci-
mens at Berlin, and being satisfied of their earlier publication, we have
no hesitation in adopting the name of Liciitenstein as the first describer
and publisher.
;i
W^^i^^
22
MUS DECUMANUS.— Pali.
Brown or Norway Rat.
PLATE LTV. — Males, Female, and Yodng.
Mus, Cauda longissima squamava, corpore setose griseo, subtus albido
CHARACTERS.
Grayish-brown above, dull white beneath, tail nearly as long as the body
feet not webbed ; of a dingy while colour.
SYNONYMES.
Mus Decumanus, Pallas, Glir., p. 91-40.
" " Schreber, Saujrthiei-e. p. 645.
" " Linn., Syst. Nat. ed. Gmel., t. p. 127.
Mus Aquaticus, Gesner's Qiuidr., p. 732.
Mis Decumanus, Shaw's Genl. Zuol., ii., p. 60 t. 130.
Surmulat, Buff., Hist. Nat. viii., p. 206 t. 27. '
Mus Decumakus, Cuv., Regne Animal, 1, p. T9?,
" " Godman, vol. \i,, p. 78.
" " Dekay, p. 79.
Mus Americanus, Dekay, American Black Rat, p. 81.
description.
Body, robu.st ; head, long ; muzzle, long, but less acute than that of the
black rat ; eyes, large and prominent ; moustaches, long, reaching to the
ears ; ears, rounded and nearly naked ; tail, generally a little shorter than
the body, (although occasionally a specimen may be found where it is of
equal length,) slightly covered with short rigid hairs. There are four toes
on each of the fore-feet, with a scarcely visible rudimental thumb, protected
by a small blunt nail ; five toes on each of the hind feet ; the feet are
clothed with short adpressed hair*. The fur seldom lies smooth, and the
animal has a rough and not an inviting appearance.
COLOUR.
Outer surface of the incisors, reddish-brown ; moustaches, white and
black ; the former colour preponderating ; the few short scattered hairs
along the outer edges of the ear, yellowish brown ; eyes, black ; hair on
nROWN OR NORWAY RAT.
2d
the back, from the roots, bluish-gray, then reddish-brown, broadly tipped
with dark brown and black. On the under surface, the softer and shorter
hair is from the roots ashy-gray broadly tipped widi white.
VARIETIES.
1st. We have on several occasions, through the kindness of friends, re-
ceived specimens of white rats which were supposed to he new species.
They proved to be albinos of the present species. Their colour was white
throughout, presenting the usual characteristics of the alliino, with red
eyes. One of this variety was preserved for many months in a cage with
the brown rat, producing young, that in this instance all ])roved to be
brow^n.
2d. We have at diflerrnt times been able to procure specimens of a sin-
gular variety of this species that seems to have originated in this country.
For the first specimen we were indebted to our friend Dr. Samuel Wilson
of Charleston. Two others were sent to us from the interior of South
Carolina. One was presented to us by a cat, niul anotlier w;is caught in a
trap. In form, in size, and in dentition, they are ])recisely like the brown
rat. The colour, however, is on l>oth surfaces quite i)l;ick. In some spe-
cimens there is under the chest and on the abdomen, n loiigitudiMal white
stripe similar to those of the mink. The specimens, .-irtcr being preserved
for a year or two, lose their intense black colour, which gradually assumes
a more brownish hue. We examined a nest of 1 lie common brown rat
containing 8 young, .'> of which were of the usual colour, and 3 black.
The specimen obtained by Mr. Bfj.l of New- York and published by Dr.
Dekav, New-York Fauna, p. 81, under the name of .1///.9 Americanus,
undoubtedly belonged to this variety, which appears to have of late years
become more common in the Southern than in the Northern Sliites. This
is evidently not a hybrid produced between Miis Dvcumanus and Mus
Rattiis, as those we have seen present the shape and size of the former,
only differing in colour.
DIMENSIONS.
From point of nose to root of tail,
Tail,
From point of nose to ear,
Height of ear - . . .
laehN.
10
9
I
^
34
BROWN OR NORWAY RAT.
HABITS.
The brown rat is unfortunately but too well known almost in ev« t"
portion of our country, and in fact throughout the world, to requiic an
elaborate account of its habits, but we will give such pnrticiilars as may
we hope be interesting. It is one of the most prolific and destructive little
quadrupeds about the residences of man, and is as fierce !is voracious.
Some cases are on record where this rat has attacked a man when he
was asleep, and we have seen both adults and children who, by their
wanting a piece of the ear, or a bit of the end of the nose, bore painful
testimony to its having attacked them while they were in bed ; it has >ieen
known to nibble at an exposed toe or finger, and sometimes to have bitten
even the remains of the shrouded dead who may have been exposed to its
attacks.
The Norway Rat is very pugnacious, and several individuals may often
be seen fighting together, squealing, biting, and indicting severe wounds
on each other. On one occasion, we saw two of these r.its in furious
combat, and so enraged were they, that one of them whose tail was turned
towards us, allowed us to seize him, which we did, giving him at the same
time such a swing against a gate post which was near, that the blow
killed him instantly — his antagonist making his escape.
During the great floods or freshets which almost annually submerge the
flat bottom-lands on the Ohio river at various places, the rats are driven
out irom their holes and seek shelter under the barns, stables, and houses
in the vicinity, and as the increasing waters cover the low grounds, may
be seen taking to pieces of drift wood and floating logs, &c., on which
they sometimes remain driving along with the currents for some distance.
They also at such times climb up into the lofts of l)arns, smokehouses, &c.,
or betake themselves to the trees in the orchards or gardens. We once,
at Shippingport, near the foot of the falls of the Ohio river, whilst residing
with our brother-in-law, the late N. Bertiioiid, went out in a skifl", during
a freshet which had exceeded those of many previous years in its altitude,
and after rowing about over the tops of fences that were secured from
rising with the waters by being anchored by large cross-timbers placed
when they were put up, under the ground, to which the posts were dove-
tailed, !ind occasionally rowing through floating worm-ti-nces which had
broken away from their proper locations and were lying flat upon the sur-
face of the flowing tide, we came to the orchard attached to the garden.
and found the peach and apple trees full of rats, which seemed almost as
active in running among the brandies as squirrels. We had our gun with
f
BROWN OR NORWAY RA'l.
2b
in evf"
requiit an
irs as may
ctive little
voracious.
1 when he
0, by their
Drc painful
it has been
lave bitten
wsed to its
rnay often
!re wounds
in furious
was turned
it the same
, the blow
bmerge the
are driven
and houses
iunds, may
, on which
le distance.
lOuses, &c.,
We once,
ilst residing
kifl", durins
its altitude,
cured from
lers placed
were dove-
)on the sur-
the ;rarden,
i5 almost as
ir gun with
-M
us and tried to shoot some of them, but the cunning rogues dived into the
water whenever we approached, and swam off in various directions, some
to one tree and some to another, so that we were puzzled which to follow.
The rats swam and dived with eciua! facility and made raj)id |)rogresN
through the water. Many of them remained in the orchard until the
Ireshet subsided, which was in the course of a few days. Whether they
caught any lish or not during this time we cannot say, but most of thtin
found food enough to keep them alive until they were able once more to
occupy their customary holes and burrows. During these occasional
floods on our western rivers, immense numbers of spiders and other in-
sects take refuge in the upper stories of the houses, and the inhabitants
find themselves much incommoded by them as well as by the turbulent
waters around their dwellings. Such times are, however, quite holidays
to the young folks, and skiffs and batteaux of every description are in re-
quisition, while some go about on a couple of boards, or paddle from street
to street on large square pine logs. When the flats are thus coversd,
there is generally but little current running on them, although the main
channel of the river flows majestically onward, covered with floating logs
and the fragments of sheds, haystacks, &;c., which have left their quiet homes
on the sides of the river many miles above, to float on a voyage of discov-
ery down to the great Mississippi, unless stopped by the way by the exer-
tions of some fortunate discoverer of their value, who rowing out among
the drifting logs, roots and branches, ties a rope to the frail floating tene-
ment, and tows it to the trunk of a tree, where he makes it fast, for the water
to leave it ready for his service, when the river has again returned to its
quiet and customary channel. Stray flat boats loaded with produce, flour,
corn and tobacco, &c., are often thus taken up, and are generally found
and claimed afterwards by their owners. The sight of the beautiful Ohio
thus swplling proudly along, and sometimes embracing the country with
its watery margin extended for miles beyond its ordinary limits, is well
worth a trip to the West in February or March. But these high freshets
do not occur every year, and depend on the melting of the snows, which
are generally dissolved so gradually that the channel of the river is suffi.
cient to carry them ofl^
In a former work, (Ornithological Biography, vol. 1, p. 155,) we have
given a more detailed account of one of the booming floods of the Ohio
and Mississippi rivers, to which we beg now to refer such of our readers
as have never witnessed one of those remarkable periodical inundations.
Mr. Ogden Hammond, formerly of Throg's Neck, near New- York, furnished
us with the following account of the mode in which the Norway Rat cap-
tures and feeds upon the small sand clams which abound on the sandy
vol.. n. — 4
26
BROWN OR NORWAY RAT.
places along the East river below high water mark. lie repaired to a
wharf on his farm with one of his men at low water: in a few moments a
rat was seen issuing from the lower jjart of the whari", j)eeping cautiously
around before he ventured from his hiding place. Presently one of the
small clams I Jiied in the soft mud and sand which they inhabit, threw
up a thin jet of water about a foot above the surface of the ground, uiM)n
M^.'ing which, the rat leaped quickly to the spot, and digging with its ton-
paws, in a few moments was seen bringing the clam towards his retreat
vhere he immediately devoured it.
When any of these clams lie too deep to be dug up by the rats, they con-
..nue on the watch and di^ after the next which may make known Us
wherealiouts by the customary jet ot water. These clams are about J oi
an inch long and not more tli;in t of an inch wide ; their shells are slight,
and they are sometimes used as bait by fishermen.
The Brown or Norway Hat was first introduced in the neighbourhood of
Henderson, Kentucky, our old and hapi)y residence for several years, with-
in our recollection.
One day a barge arrived from New-Orleans (we think in 1811) loaded
with sugar and other goods ; some of the cargo belonged to us. During
the landing of the packages we saw se'eral of these rats make their escape
from the vessel to the shore, and run off in diti'crent directi<)ns. In a year
from this time they bad become quite a imisance ; whether they had been re-
inforced by other importations, or had multiplied to an incredible extent, wo
know not. Shortly after this period we had our .- jkehousc floor taken up
on account of their having burrowed under it in nearly every direction.
We killed at that time a great many of them with the aid of our dogs, but
they continued to annoy us, and the readers of our Ornithological Biography
are aware, that ere we lefl Henderson some rats destroyed many of our
valued drawings.
This species migrates either in troops or singly, and for this purpose
takes passage in any conveyance that may offer, or it plods along on foot.
It swims and dives well, as we have already remarked, so that rivers or
water-courses do not obstruct its progress. We once knew a female to
secrete herself in a wagon, loaded with bale rope, sent from Lexington,
(Ky.) to Louisville, and on the wagon reaching its destination, when the
coils of rope were turned out, it was discovered that the animal had a lit-
ter of several young ones : she darted into the warehouse through the iron
bars which were placed like a grating in front of the cellar windows. Some
of the young escaped also, but several of them were killed by the wagoner
How this rat was fed during the journey we do not know, but a.s the wagons
BROWN OR NORWAY RAT.
87
aired to a
moments a
ciiutiously
one of the
iibit, threw
ounil, upon
ith its l'or»»
his retreat
S they con-
known ItH
are sliglit,
ourhood of
rears, with-
s. During
heir escape
In a year
! extent, we
or taken up
y direction,
ir dogs, but
Biography
lany of our
lis purpose
ng on foot,
at rivers or
a female to
Lexington,
, when the
igh the iron
iws. Some
le wagoner
the wagons
stop every evening at some tavern, the probability is that she procured food
for herself by getting out during the night and picking up corn, &c.
The Norwiiy Rat freejuently deserts a locality in which it ims for some
tifne remaini'd and provfd a great pest. When this is the case, the whole
tribe Journey to other (piarfers, keeping together and generally appearing
in numbers i:i their new locality without any previous warning to the un-
lucky farmer or housekeeper to who;, -^remises they have taken o fancy.
When we first moved to our ret rear, nine miles above the city of New-
York, we had no rats to annoy us, and we .)oped it woi:'; be some time b.'-
fore they discovered the spot where we > ' '^caf^d i jr jlves. But in the
course of a few months a great many ot i... 1.1 appeared, and we have
occasionally had eggs, chickens and ducklings carrieu > /^by them to the
number of six or more in a night. We have never been able to get rid of
this colony of rats, and they have even mjide large barrows in the banks
on the water side, where they can hardly be extirpated.
The Norway Rat is quite abundant in New-York and mosc other mari-
time cities, along the wharves and docks, and becomes very large. These
animals are frequently destroyed in great numbers, while a ship is in port,
after her cargo has been discharged, by smoking them ; the fumes '•'.' sul-
phur and other suffocating materials, being confined to the hold by closing
all parts, windows and hatches. After a thorough cleaning out, a large
ship has been Unown to have had many thousands on board. Our old
friend, Capt. Ciimingh, who in early life made many voyages to the E?'st
Indies, relates to us, that one of his captains used to have rats caugh.,
when on long voyages, and had them cooked and served up at his table
as a luxury. lie allowed his sailors a glass of grog for every rat thev
caught, and as the supply was generally ample, he used to invite his mates
and passengers to partake of them with vlue hospitality. Our friend, who
was a mate, had a great horror of the captain's invitations, for it was some-
times difficult to ascertain in what form the delic;ite animals would appear,
and to avoid eating them. Not having ourselves eaten rats, (as far as we
know,) we cannot say whether the old India captain's fondness for them
was justified by their possessing a fine flavour, but we do think prejudices
are entertained against many animals and reptiles that are, after all, pretty
good eating.
In the account of the black rat in our first volume, {Mus rattu.i,) pp. 190,
191, and 192, we gave some details of the habits of the present species,
and stated our opinion in regard to its destroying the black rat. Dr. God-
man considered the Norway Rat so thorough an enemy of the black rat,
that he says, (vol. 2, p. 83,) in speaking of the latter, that it is now found
only in situations to which the Brown Rat has not extended its migrations.
11
I Jf.
98
BROWN OR NORWAY RAl
According to the same author, who (|Uotes 11. Smith, Uat Catcher, p. 5, 17(18,
(sei! GouMAN, vol. 2, p. 77,) the Urowr> Hat was not known ev<n in Europe
prior to the year 1750. Kichardnon says, (probahly quoting' from IIari.av,
Fauna, p. 141),) that it was brought I'roin Asia to Europe, according? to the
accounts ol'historiaiis olihe seventeenth century, and was unknown in Eng-
hm.l l).'(ore 1 7:{(). 1'ennan r, writinjr i„ 178.",, says he has no autho- y for con-
sidering it an inhabitant ofthe new continent (America). Harlan states
that the Norwegian rat did not, as he was cre(ni)ly inlbrmed, maiio
its appearance in the United States any length of time previous to the
year 1775. Harlan does not give the Brown Rat as an American species,
giving only what he considered indigenous species.
The Brown Uat brings forth from 10 to 15 young at a litter, and breeds
several times in a year. Fortunately for mankind it has many enemies :
weasels, skunks, owls, hawks, &c., as well as cats and dogs. We have never
known the latter to eat them, but they may at times do so. Rats are also
killed by each other, and the weak ones devoured by the stronger.
This species becomes very iat and clumsy when living a long time in
mills or warehouses. We have often seen old ones so fat and inactive
that they would fall back when attempting to ascend a staircase.
We will take our leave of this disagieeable pest, by saying, that it ,.i
omnivorous, devouring with equal voracity meat of all kinds, eggs, poul-
try, fish, reptiles, ve^'^tables, &c. &c. It prefers eels to other kinds of lish,
having been known to select an eel out of a large bucket of fresh fishi
and drag it off to its hole. In vegetable gardens it devours melons, cu-
cumbers, &c., and will cat into a melon, entering through a hole large
enough to admit its body, consuming the tender sweet iruit, seeds and
all, and leaving the rind almost perfect. Where rats have gained
access to a field or vegetable garden, they generally dig holes near the
fruits or vegetables, into which they can make an easy retreat at the ap-
proaeh of an enemy.
We have represented several of these rats in our plate about to devour
muskmelons, for which they have a strong predilection.
GEOORAPinCAL niPTRrBIJTION.
The Mus Dicumanut is found in all the temperate parts of th;^ world
when; man has been able to carry it in ships. It has not as yet penetrat-
ed into the fur countries, to the Rocky Mountains and California. The
Nrotoma JJrummondi would probably be able to destroy it, being quite
s fierce and much larger, should its wanderings lead it into the territory
-jccupied by the latter. The Brown or Norway Rat is met with almosl
BROWN OR NORWAY RAT.
!r, p. 5, 17(18,
rn ill Europe
rorn IIaki.av,
•idiiif? to the
own ill Eiig-
u' Y Jor coii-
ARLAN States
rined, rniiivu
svioiis to the
ican species,
, and breeds
ny enemies :
B have never
[ats are also
ger.
long time in
ind inactive
ise.
g, that it i.i
eggs, poul-
:inds of lish,
)!' fresh fish,
melons, cii-
hole large
, seeds and
ive gained
Bs near the
t at the ap-
n
every where from Nova Scotia to and beyond our southern ranjc, except
in the western and northern regions above, tientioiied, and there even it
will soon be found in California, at the mouth of the Columbia river, and
among the settlements in Oregon.
GENERAL REMARKS.
We had assigned to Linnaii-s the credit of having been the first descriher
of the Brown Rat. On turning however to his 12th edition, wo find no
notice of this species. In a subsetiuent edition published by Gmei-in in 177b.
a description is added. It had however been previously describet' bv Pai^
LAS in J7()7 under the name which it still retains. He is therelore entitled
tu the priority.
t to devour
th;! world
it penetrat-
rnia. The
leing quite
le territory
i^ith almost
m
?i
so
SCIUEUS EUBICAUDATUS.— AuD. and Bach.
Red-Tailed Squirrel.
PLATE LV.
S. supra sub rufus cano mistus, subtus sordide flavus, magnitudine Intel
8. cino) eum et s. migratorium ; cauda auriculisque rufis.
CHARACTERS.
Inte} mediate in size between the cat squirrel (S. Cinereus) and the North
em gray squirrel {S. Migratorius) ; ears and tail, red ; body, light-brown
mixed w tk gray above, soiled buff beneath.
DESCRIPTION.
In for. n this species resembles the northern gray squirrel, possessing
evidently all its activity ; its proportions are more delicate, and it weighs
less, than the cat squirrel. It is considerably smaller than the great-tailed
squirrel of Say, (S. Sayi). Although a little larger than the northern gray
squirrel, its tail is shorter, and its fur a little coarser. The only specimen
in which we were enabled to examine the dentition, had but twenty teeth ;
the small front molars which appear to be permanent in the northern gray
squirrel, and deciduous in several other species, were here entirely wanting.
COLOUR.
The fur on the back is in half its length from the roots, plumbeous, suc-
ceeded by a narrow marking of light brown, then black, tipped with
whitish, a few interspersed hairs are black at the apical portion ; on the
under surface the hairs are yellowish-white at the roots, and reddish-buff
at the tips. The long hairs on the under surface of the tail are red through
their whole extent. On the upper surface of the tail the hairs are reddish
with three black annulations, tipped with red. Moustaches, black ; ears,
around the eye, sides of face, throat and neck, inner surlace ol legs, u|)per
surface of feet and belly, dull buff: tail, rufous.
RED-TAILRJ) StiUlRREL.
81
kcn.
tudine in^ei
i the North-
light-hrown
DIMENSIONS.
Length, from point of nose to root of tail,
Do. vertebra;, •---..
Do. to end of hair, . . . .
Height of ear, ---..-
Heel to end of longest nail,
HABITS.
lochM
13
10
12 j
i
2f
We have obtained no information in regard to the habits of this species,
but have no doubt it possesses all the sprightliness and activity of other
squirrels, particularly the Northern gray and cat squirrels, as well as the
great tailed squirrel, to which in form and size it is allied.
GEOGRAPHICAL DISTRIBUTION.
, possessing
nd it weighs
great-tailed
>rthern gray
ly specimen
i'enty teeth ;
jrthern gray
;ly wanting.
ibeous. suc-
tippcd with
fion ; on the
reddish-buff
red through
, are reddish
ilack ; ears,
legs, ujiper
The specimen from which our drawing was made, was procured in the
State of Illinois. This squirrel is also found in the barrens of Kentucky:
vvc possess a skin sent to us by our good friend Dr. Crogiian, procured we
Dciieve near the celebrated Mammoth cave, of which he is proprietor.
Mr. Cabot, of Boston, likewise has one, as well as we can recollect, in
his collection. We sought in vain, while on our journey in the wilds of the
Upper Missouri country, for this species, which apparently does not extend
its range west of the well-wooded districts lying to the east of the great
prairies. It will probably be found abundant in Indiana, although it has
been hitherto most frequently observed in Illinois. Of its northern and
southern limits, we know nothing, and it may have a much more extended
distribution than is at present supposed.
32
GENUS BISON.— PuNv
DENTAL FORMULA.
^ Incisive -; Canine — ; Molar — =32.
" 0—0 6—6
the salient line of the frontal crest; tail, short; shoulders, elevated ; hair,
soft and woolly.
The generic name is derived from Pliny, who applied the word Bison,
wild ox, to one of the species on the Eastern continent.
There are five species of Buffalo that may be conveniently arranged
under this genus : one existing in the forests of Southern Russia in Asia,
in the Circassian mountains, and the desert of Kobi ; one in Ethiopia and
the forests of India, one on the mountains of Central Asia, one in Ceylon
and one in America. In addition to this, the genus Bos, which formerly
included the present, contains five well determined species, one inhabiting
the coun.ry near the Cape of Good Hope, one in Central Africa, one in
the Himalaya mountains and the Birman Empire, one in India, antl one
m the forests of Middle Europe.
BISON AMERICANUS.— Gmkt.,
American Bison. — Boffalo.
PLATE LVI. Male.
PLATE LVII. Female, Male and Youno.
B. capite magno, lato, fronte levifer arcuata; cornibus parvis, b-evi-
bus, teretibus, extrorsum dein sursum versis ; cauda breve, crurib'us gra-
cilibus armis excelsis, villo molli, lanoso.
CHARACTERS.
and upwards ; tail, short • legs, slender ; shoulders, elevated ■ hair, soft
rtnd woolly.
BUFFALO
88
BYNONYMES.
Taurus Mexicanus, Hernandez, Mex., p. 587, Fig. male, 1651,
Taureau Sauvaoe, Hennepin, Nouv. Discov., vol. i., p. 186, 1090.
'I'iiK Buffalo, Law.son's Carolina, p. llo, fV.
" Catesby's Carolina, Appendi.x .\x.\ii., tab. 20.
" " Hearne's Journej', p. 412.
" " Franklin's Finst Voy., p. 113.
" " Pennant's Arctic Zool, vol. i., p. l.
Long's Expedition, vol. iii., p. 68.
" Warden's U. S., vol. i.. p. 248.
Bos Amekioams, Linn., S. N., ed Gmel. 1, p. 204.
Cuv., Regno an 1, p. 270.
Bos Amekic'anijj, Harlan, 268.
" " Godman, vol. iii., 4.
Richardson, Fa., p. 79.
Ameuican Ox, Dobs, Hudson's Bay, 41.
|lj !
BESCRIl'TIOJJ.
Male, killed on the Yellow Stone river, July IGth, 1843.
The form beans a consid.i able re-semblance to that of an overgrown dri-
mestic bull, the top of the hump on the shoulders being considerably higher
than the rump, although the fore-legs are very short ; horns, short, stout,
curved upward and inward, one foot one inch and a half around the
curve ; ears, short and slightly triangular towards the point ; nose, bare •,
nostrils, covered internally with hairs ; eyes, rather small in proportion
to the size of the animal, sunk into the prominent projection of the skull ;
neck, and forehead to near the nose, covered with a dense mass of shagg J
hair fourteen inches long between the h ^irns, which, as well as the eyes
and ears, are thereby partially concealed, these hairs become gradually
shorter and more woolly towards the muzzle. Under the chin and lower
jaw there is an immense beard, a foot or upwards in length
Neck, short ; hairs along the shoulder and fore-legs about four inches long,
rhe beard around the muzzlt; resembles that of the common bull. A mass
of hair rises on the hind part of the fore-leg, considerably below the knee.
A ridge of hairs commences on the back and runs to a point near the in-
sertion of the tail. On the flank.s, rump and fore-legs the hairs are very
short and fine.
On the hind-legs there are .straggling long hairs extending to the kner,
and a (i-w tufts extending six inches below the knee ; hind-legs, an]
tail, covered with short hairs; within a few inches of the tip of the tail
ther.- is a tuft of hair nearly a foot in length. The pelage on the head
vol. II. .")
:*^ir
34
BUFFALO.
has scarcely any of the soft woolly hair which covers other parts of the
body, and approaches nearer to hair than to wool.
A winter killed specimen.
From the neck, around the shoulder and sides, the hody is covered with
a dense lieavy coat of woolly hair, with much longer and coarser hairs in-
termixed. There is a fleshy niend)rane between the forelegs, like that in
the common domestic bull, but not so pendulous.
Female.
In form and colour ihe female bears a strong resemblance to the male;
she is, howevei-, considerably smaller, and of a more delicate structure.
Iler horns are of ihe same length and shape as those of the male, but are
lliinner and more perfect, in consequence of the cows engaging less in
combat than the bulls. The hump is less elevated ; the hair on the lore-
head shorter and less bushy ; the rings on the horns are more corrugated
than on those oi'our domestic cattle.
Spinous processes rising from the back bone or vertebra; of the bull, and
forming the hump : they are flat, with sharp edges both anteriorly and
posteriorly; the two longest are eigliteen and a quarter inches long,
three inches at the end which is the widest, and two inches at the
narrowest ; the first, fifteen inches ; second, (largest,) eighteen and a quar-
ter inches in length ; third, sixuen and a half; fourth, sixteen ; the fifth, fif-
teen inches, and the rest gradually diminishing in size ; the fifteenth spinous
process being three and a half inches long; the remainder are wanting in
our specimen. The whole of the processes are jjlaced almost touching
each other at the insertion and at the end, and their breadlh is parallel to
the course of the back-bone. In the centre or about half the distance from
the insertion to the outer end of them, they are {ihv bone being narrower
in that part) Irom a quarter to one inch ai)art. The ribs originate and in-
cline outward backward and downward Irom between these upright
spinous bones.
COLOUR,
A summer specimen.
Head, neck, throat, fore-legs, tail and beard, dark l)rownish-black ;
hoofs, brown ; rum]). Hanks, line on the back, blackish brown ; horns nearly
Llack. Up])er surface of body light-brown; the hairs uniform in colour
from the roois, the whole; under surl'ace blackish-brown.
Tiie colour of the female is similar o thai of the male.
At the close ol' the summer when the new coat of hair has been obtairedj
BUFFAIjO.
85
tht! Buffalo is in colour between a dark umber, and liver-shining brown ;
as the hair lengthens during winter, the tips become paler.
Young male, twelve months old.
A uniform dingy brown colour, with a dark brown stripe of twisted woolly
upright hairs, extending I'roni the head over the neck slioulders and back
to the insertion of the tail. . The hairs on the forehead, which form the
enormous mass on the head of the adult, are just beginning to be deve-
loped.
Under the throat and along the chest the hairs extend in a narrow line
of about three inches in length ; the bush at the end of the tail is tolerably
well developed. Hairs on the whole body short and woolly.
A calf, six weeks old, presents the same general appearance, but is
more woolly. The legs, especially near the hoofs, are of a lighter colour
A calf taken from the body of a cow, in September, was covered with
woolly hair ; the uniform brownish, or dim yellow, strongly resembling
the young of a domesticated cow.
i*"
' t i
HABITS.
Whether we consider this noble animal as an object of the chase, or as
an article of food for man, it is decidedly the most important of all our con-
temporary American quadrupeds ; and as we can no longer see the gi-
gantic mastodon passing over the broad savannas, or laving his enormous
sides in the deep rivers of our wide-spread land, we will consider the
Hudiilo as a link, (perhnps sooner to be forever lost than is generally sup-
posed.) which to a slight degree yet connects us with larger American ani-
■iials, i)elonging to extinct creations.
But ere we endeavour to place before you the living and breathing herds
of Buffaloes, you must journey with us in imaginalion to the vast west-
ern prairies, th,- sechided and almost inaccessil)le valleys of the Rocky
Mountain chain, and the arid and nearly impassable deserts of the western
tai)le lands of our country; and here we may be allowed to express our
deep, though unavailing regret, that the world now contains only few and
imporfcot remains of the lost races, of which we have our sole knowledge
through the rcsearciies and profound deductions of geologists ; and even
fhousrh our knowledge of the osteolo<j:y oIllKMiiore recently exterminated
species i)e si.H .i.-nt to place them before our " mind's eye," we have no de-
scription a . MO fitrures of the once living and moving, but now de-
parted pos . .ss..rs of these woods, plains, mountains ani waters, in which,
: i II
iki
86
BUFFALO.
\$■
ages ago, they are supposed to havp ikvw If r f i
humble efforts .ay atlast ^^Zl t pe'l ^t 7^7^ T' ''T ""'
species as the Give,- ofal, ,ood has .^loS^^Z^ ^ thl fth "='
s..^.^_^Aaaao.._d^
In .he days of our boyhood and youth, Bu.laloes roan.ed over the srrall
-.d be.uu,„d .nunc, of Indiana and Illinois, and herds of the,. .I^d
; . ^ the open woods ofKentucky and Tennessee ; but they ha U ^
' -.. - a lew stragglers, which resorted chiefly to ,he ''Barr " '
-urds the years i808 and 18„9, and soon after entirely dislpear d Tl
range has since that period gradually tended wes wu^ C
must direct your steps " to the Indian countr " Td " ,' " T ^
n^ies beyond ,he .hir valleys of the Ohio, t^al t ; ^^^i^": ^
of mountauis which forms the backbone ofNorth-Americ^ .
reach the Buffalo, and see him roving in his st d in '"" "'"
vajf ele.-.ed .ains. which extend ^ th^C i:;^ 1^:^-^' ''^
Hie w„h us then to the West ! lot us quit the busv streets of S •
once co..idered the outpost of eivi.i.ation; but now 1 ^ i^ !^;^t
scattered lor hundreds of miles beyond it; let us leave ,he busy haun s'of
rnen, and on good horses take the course that will lead us in, ,^ B^ffU
-g^n,_an when we have arrived at the sterile and ex.en.Ied p,ai:s^ ie^
wedeszretoreach, we shall be recompensed Ibr our toilsonu and t di u
journey: for there we may "nd thousands of these noble aninu.l T
enabled to study theh- habi.s, as they graze and -amble over .^ ^^H^
or migrate from one range o,' country to another, crossing on e "" He
water-ccHU-^s, or swinnning rivers at places where th..- o^n plu " :
chemuddy bank inu> the stream, to gain a san.l-bar .• .hoal n,i,I va
e r.ver. that affords them a resting place, from which, af,er a Mule L
hey can d.rect their course to the opposite shore, when, having rea h d i *
|M- just scramble up the bank, ere they can gain the ^.en pl^rle
There we may also witness severe combats between ihe valiant bulls
- the rutt.ng season, hear their angry bellowing, and observe t u ' ! . 1
city as well as courage, when disturbed by the approach of man ' ^
The An.enoan Bison is much a.ldiced to wandering, an.l the v-.rious
herds annual^- remove from the Nor.h, at the approach o vint .
|-y n^., be f und, during that season, remaining in high la^lud M
n, c.i ly. Durmg a s.-ve. ,■ winter, however, numbers of the.n ppr^sb
especally the old. and the very young ones. The breedn.g .ealn 'gel
BUFFALO,
37
emlly the months of June and July, and the calves are brousht forth in
April and May ; although occasionally they are produced as early as March
or as late as July The BulFalo most frequently has hut one calf at a
time, hut instances occur of their having two. The females usually re.
tire fi-om the herd either singly or several in companv, select as solitary a
spot as can he found, remote from the haunt of wolves, bears, or other
enemies that would he most likely to molest them, and there produce their
young.
Occasionally, however, they bring fort', their ofTspring when the herd
IS migrating, and at such times they are left by the main body, which they
rejoin as soon as possible. The young usuallv follow the mother until
she IS nearly ready to have a calf again. The Bulfalo seldom produces
young until the third year, but will continue breeding until very old
When a cow and her very young calf are attacked by wolves, the cow
bellows and sometimes runs at the enemy, and not unfrequentiv fri-htens
him away; this, however, is more generally the ease x^lwn srVeivdcous
are together, as the wolf, ever on the watch, is sometimes able to secure
a calf when it is only protected by its mother.
The BulTalo begins to shed its hair as .-arly as Pebruarv. This l\x\\u'<r of
the winter coat shows first between the fore-legs and around the udder in
the female on the inner surface of the thighs, &c. Next, the entire pela-e
of long hairs drop gradually but irregularly, leaving almost naked patches
in some places, whilst other portions arc covered with loosely han<Mncr
wool and hair. At this period these animals have an extreme"lv ra--ed
and miserable appearance. The last part of the slunlding process takes
place on the hump. During the time of shedding, the Bison searches for
trees, bushes, &c., against which to rub himself, and thereby facilitate
the speedy falling oif of his old hair. It is not until the end of Septemi)er,
or later, that he gains his new coat of hair. The skin of a Buffalo, killed
in October, the hunters generally consider, makes a good Buffalo' robe ;
and who is there, that has driven in an open sleigh or wa-on. that will
not be ready to admit this covering to be the cheapest and the best, as a
protection from the cold, rain, sleet, and the drifting snows of winter ? for it is
not only a warm covering, but iiiif)ervious to water.
The Bison bulls generally select a mate from among a herd of cows
rnd do not leave their chosen one until she is about to calve.
When two or more males fancy Ihesan... female, furious battles ensue
and the eonqu.'ror leads off the fair cause of the .contest in triumph. Should
the cow be alone, the defeated lov.>rs follow the hapi)y pair at such a re-
spectful distance, as will ensure to them a chance to make their eseap...
if they should again become obnoxious to the victor, and .at the same time
nil
mx I
I: ''
I i
88
BUFFALO.
enable them to take advantage of any accident that might happen in theii
favour. But should the light have been caused by a female who is in a large
herd of cows, the (iiscomfitcd bull soon finds a sul)sf itute for his lirst passion.
It frequently linpi)ons, that a bull lends oil' a cow, !ind remains with her
separated (ln'-ng the season from all oliiers, either male or female.
When the i^uti'alo hull is working himself up to a heiligerent state,
lie |)aws the ground, bellows loudly, and goes through nearly all the
actions we may see performed by the domesticated bull under similar
circumstances, and finally ruslies at his fi.e head foremost, with all his
speed and strength. Notwithstanding the violent shock with which two
bidls thus meet in mad career, these encounters have never been known
to result fatally, probably owing to the strength of the spinous [)rocess
commonly called the hump, the shortness of their horns, and the (juan-
tiry of hair about all their fore-parts.
When congregated together in fair weather, calm or nearly so, the
bellowing of a large herd (which sometimes contains a thousand) mav
be heard at the extraordinary distance often miles at least.
During the rutting season, or while lighting, (we are not sure which,)
the bulls scrape or paw up the grass in a circle, sometimes ten feet in di-
ameter, and these places being resorted to, from time to time, by other
fighting bulls, become larger and deeper, and are easily recognised even
afler rains have filled them with water.
In winter, when the ice has l)ccome strong enou<rli to bear the
weight of many tons, Bufialoes are often drowned in great numbers, lor
tliey are in the ha])it of crossing rivers on the ice, and should any alarm
occur, rush in a dense crowd to one place ; the ice gives way J)eneath the
pressure of hundreds of these huge animals, they an; preci|)itated into the
wafer, and if it is deep enough to reach over their backs, soon perish.
Should the water, however, be shallow, they sculTle through the broken
and breaking ice, in the greatest disorder, to tlie shore.
From time to time small herds, crossing rivers on the ice is the spring,
are set adrift, in consecjuence of the sudden breaking of the ice after a
rise in the river. They have been seen floating on such occasions in
groups of three, four, and sometimes eight or ten together, althougli on
separate cakes of ice. A few stragglers liave been known to reach the
shore in an almost exhaust.-d stat(>, but the majority peri.^h from cold and
want of food rather than trust tliemselves boldly to the turbulent waters.
Buflalo calves are often drowned, from being unable to ascend the steep
banks of the rivers across which they linve just swam, as the cows cannot
help them, althougli they stand near the bank, and will not leave them to
their fate unless something alarms them.
bl/FFALO.
89
On one occasion Mr. Kipp, of the American Pur Company, caught eleven
calves, their dams all the time standing near the top of the bank. Fre
quentiy, however, the cows leave the young to their fate, when most ol
them |)erish. In connection wifh Ihis part of the subject, we may add,
that we were informed when on the Fppe. Missouri river, that v/hen tlie'
banks of tliat river were practicable lor cows, and their calves could not
Ibllow tliem, they went down again, after having gained the to{), and
would remain by them until forced away by the cravings of hunger.
When thus forced by the necessity of saving themselves to quit their
young, they seldom, if ever, returned to them.
When a large herd of these wild animals are crossing a river, the calves
or yearlings manage to get on the backs of the cows, and are' thus con-
v.'ved safely over ; l)ut when the heavy animals, old and young, reach the
slion-, I hey sometimes find it muddy or even deeply miry ; the strength of
the old ones struggling in such cases to gain a solid footing, enables I hem
to work their w.ay out of danger in a wonderfully short time. Old bulls,
indeed, have been known to extricate themselves when .hey had got into
the mire so deep that but little more than their heads a!id backs could be
K 11. On one occasion we saw an unfortunate cow that had fallen into,
or rather sank into a quicksand only seven or eight Ibet wide ; she was
quite dead, jmd we walked on her still fresh carcase safely across the ra
vine which had buried her in its treacherous and shifting sands.
Tlu! gaits of the Bison are walking, cantering, and galloning, and when
.•It full speed, he can get over the ground nearly as fast as the b(!st horses
found in the Indian country. In lying down, this species bends the fore
legs first, and its movements are almost exactly the same as those of th.
eonunoii cow. It also rises with the same kind of action as cattle
When surprised in a recumbent posture by the sudden appro.aehofa
hunter, who has succeeded in nearing it under the cover of a hill, clump
of trees or other interposing object, the Bison springs from the groimd and
is in lull race almost as quick as thought, and is so very alert, that one
can scarcely perceive his m.nnner of rising on such occasions.
The bulls never grow as fat as the cows, the latter having been oeen-
sionally killed with as much as two inches of fat on (he boss or hump and
along the back to the tail. The fat rarely exceeds half an inch on the
sides or ribs, but is thicker on the belly. Tlie males have only one inet
of fat, nnd their flesh is never considered equ.al to that of the females in de-
licacy or flavour. In a, herd of Bullaloes many .-.re poor, and even at the
best se.ison it is not likely th.at all will be found in good condition ; and we
bnve occasionally known a hunting party, when Bullalo wus scnrce, con.-
peiled to feed on a straggling old bull .as tough as leather. For ourselves, mis
III
''9
40
BliFFAI.O.
'Mi
ft!
was rather uncn.forfablo, as we had lu.ibrtunately lost our molars Ions
nfro.
Tlu> 15is,„. is sonu.fimrs moro al)uiulavt in particular districts one yeai
thai.un<.thcr. .-..ul is ,„„lMl,ly ii.liucnc.i i,. its vvund.-rin-s l,v the mil.lness
or scvcrily ..I. he w.a.h.T. as well as l,y the choice it makes of (he best
pasturafic and most quiet portions of the prairies. While we were at Fort
Union, th.. hunters were durinfr tl.e month of Jun.- ohiit^od to go out twenty-
hve or thutyuiih-s to procure IJuliaio meat, aithou-h at other times the
animal was quite ahun.h.nt in sight of, he (bri. The tran.ping ola large
herd, in wet weather, cuts up the soft clayey soil ofth.. river bottoms (ue
«Io not not .Mean tlu- bottom of rivers,) into a complete mush. One' day.
wlu-n on ourjourn.-y up the Missouri river, we landed on one oCthe nar-
row stnps of h.ndealle,! bottoms, which Ibrmed the margin of the river
nnd was back,.! by hills of consi.lerabh- height at a short dislanee At
this spot the tracks of these animals were literally innumerable, as
lar as the eye could rea.-h in ev.-ry direction, the plain was covered wi.h
them; and in s.ane places the soil had been so tran>ph-d as to rrscmble
nm<l or clay, wh.m j.repared fur making bricks. The trees in the vicinity
wer,> rubbed by these bulfaloes, and their hair and v.'ool were hangin-^ on
t u- rough bark or lying at tluMr roots. We collected soua- ..f this wool? we
tinnk.t .uight be usefully worked up into coarse cloth, an.l consider it
worth att.M.tion. The road • that are made by th.-se animals, so umch re-
semble the tracks left b, a large wagon-t rain, that the in..xperienced
traveller may occasionally imagine hims,.|C (i,|i„,ving the course of an or-
dinary wagon-road. These great tracks run for hundreds of miles across
the prairies, and are usually found to lead to s„me salt-spri„g, „r some
river or creek, where tiie animals can allay their thirst.
The captain of the .steamboat on which we'asc.Mul-d the Missouri inform-
ed us. that on his last annual v,.\ Mi,e up that river, he had caught' .several
Bullaloes. that were swimming the river. The boat was run elo.se upon
hem th,.y were lassoed by a Spaniar.l, who happene.l to be on board, an.l
then hoisted on the deck, where they were butchered secun.knn arlem One
day we saw.several that had taken to the water, and were .•oMmr^ towards
our boat. We passed so near them, that we fired at them, but did not nro'-
cure a single one. On another occasion, one was killed from the shore and
brought ;-.; .nard, when it was imme.liately divided among the m.Mi ' W
were greatly surprised to see some of the In.lians, that wen- goin-^ up witl
us, ask (or certain portions of the entrails, which they devoured with the
greatest voracity. This gluttony excited our curiosity, and being alwav-
Willing to ascertain the quality of any sort of meat, we tasted some of tius
BUf'FALO.
41
Bort of tripe, ,i.n. loi.n.l it very good, altl.oiiRh at first its appearance was
rather revolliiiy.
'J'he Indians soinetitnes eat the carcasses of Ruiraloes that iiave been
drowned, and some of those on lu.ard the; Onw^ii one day asked the cap-
lain most earnestly to allow t!,eni to land and got at the bodies ol ihren
J{t'lial<.es which w.. passed, that had lo.lfred among the drift-logs and were
pi-ohably hair putrid. In this extraonlinary rcpiest some of the sipiaws
joined. That, when sfimnlal.'d by the gnawings of l.ung.-r, Indians, or even
Whites, should fe(!d upon carrion, is not to be wondered at, since we have
many instances of caimi alism and other horrors, when men are in a state
of starvation, but th(!s.; Indians were in the midst of plenty of wholesome
Ibod and we are inclined to think their hankering afteV tliis disgusting
flesh must be attributed to a natun.1 taste for it, pro»)ably acciuired" when
young, as tliey are no doubt sometimes obliged in their wanderings over the
pr.iiries in wint<-r, to devour carrion and even l)ones and hides, to pr.-serve
their lives. In the height of the rutting-se.-.son, the flesh of the Buffalo bull is
quite rank, and unfit to be eaten, except from necessity, and at this time
the animal can be scented at a consi(''jrable distance.
Wlu^n a lierd of Bisons is chased, although the bulls run with great swift-
ness their sj)eed cannot be compared with thatoftlie cows and yearling
calves. These, in a few momejits leave the hulls behind them, but as they
are greatly preferred by the hunter, ^e always (if well mounted) pursues
them and allows the bulls to escape. During the winter of 1812 and 43,
as we were told. Buffaloes were abundant around Fort Union, and dur' ig
the night picked up straggling handfuls of hay that happened to be
scattered about the place. An attempt was made u> secure some of them
alive, by strewing hay as a bait, from the interior of the old fort, which
is about two hundred yards off, to .:■-" Jistance from the gateway,' hoping
the animals would feed along into tlic enclosure- They ate the hay to the
very gate ; but as the hogs and common cattle were regularly placed there,
for security, during the night, the Buffaloes would not enter, probably on
account of the various odours issuing from the interior. As the Rufi'aloes
generally found some hay scattered around, they soon became accustomed
to sleep in the vicinity of the fort, but went off every morning, and dis
ajjpeared behin.'. the hills, al)out a mile off".
One night they were fired at, from a four-pounder loaded with musket-
balls. Three were killed, and several were wounded, but this disaster did
not prevent them from returning frequently to the fort at nighr, and they
were occasionally shot, during the whole wi.iter, quite near the fort.
As various accounts of Buffalo-hunts have been already written, we
will pass over our eariiest adventures in that way, which occurred many
VO!,. II. —
ri I
4i
BUFFALO.
>eaM H'^o, iind ffivv. you mcroly ii Nki-tcii i)f the mode in wliiilj we killec?
them <liiiiii« oiir.JDunify fo till! West, in lN|;j.
OiH! niorniii- in July, oim' jiiiify and srvcr.il p.'rMons nffnclird to Fort
Union, (lor w,. wnv iIi.mi Iocmi.mI iIut.",) ,T(..ss,.(i il„. ,iv,.r. I.indrd ..|,|,„-
Nite the lbrt,iind passing tlnontrli t\w rid. allnvial hrll of woodland wl.icli
nmr-ins tin- riv.-r, wvn- .ariy on our way to tli.- adjacrnt prairi.-, hi-yond
the hills. Oar <'(|ui|)ni(Mit consisl.'d ..fan „!,! J.-rscy wa«on, to which wo
hadlwohorst's allaehcd, tandem, driven hy .Mr. C. i.mansnN, principal at
the lort. Tliis wa>,'on carried Mr. Kakkih, IJr.i.i,, and ourselves, and we
were followed hy two carls, which lained the rest „r the party, while
hehind came the rmmin« horses or himlers, led carelully alonir. After
crossing' the lower prairie, we ascended hetween ;lie sK'cp hanks of iho
nitrxed ravines, imlil we reached the hi«h nndnlalin^r plains above. On
turnins: to take a retrospective vi.-w, we beheld ih,' fort and a e(.nsid,.r.
nbic expanse of broken and prairie-land l)eliin(l us, and the course- of tlie
river was seen as it wound alonjj, li.r some distance. Uesumin^r „ur ad-
vance we soon saw a nund.cr of anielopes. some of which had youn-? ones
Willi them. Alh-r travelling,' about len miles farther we approached the
Fox river, and at this point one of the party espied a small herd of jjisons
at a considerable distance olf. Mr. Ciii.nKRrsoN, after seanrhin;,' for them
with the telescope, handed it to un and showed us where ihey were. They
verc! all lyinj; down and apjx-ar.-d perfectly unconscious of the cxisf.Mico
of our party. Our vehicles and horses were now turned towards them
and wc travelled cautiously to witiiin about a (piarter of a mile of the herd,
covered by a hi-li ridjr.' of land which concealed us from their view.'
'I'he wind was favourable, (blowini,' towards us.) and now the hunlers threw
aside their coats, tied ' Midkercliicfs around their heads, looked to their
guns, mounted their siei as, and moved slowly and cautiously towards the
f;iimc. The rest of the party crawled carefully to the top of the ri(I<fe to
seethe chase. At the word of command, driven by Mr. Cn.nERrsoN, the
hunters dashed forward after the bulls, which already be-an to run olt
in a linc^ nearly parallel with the rid-j;e we were upon. The swift horses,
ururedonby theircaser riders and th.Mr own impetuosity, soon bejran to
overtak.. the aini-hted animals; two oflhem separated* from the others
and were pursued by Mr. Cui.i.krtson and ."Mr. IJki.i, ; presently the former
fired, and we could see that he had wounded one of the bulls. It stopped
aft.>r jioiny; a little way and stood with its head han-,'infr down and its
nose near the j;round. Tiie blood appeared to be pourin- from its mouth
and nostrils, and its droopin- tail showed the a<?ony of the poor beast. •
Yet it stood lirm.Mnd its sturdy le-s iiplield its ponderous body as if nou-ht
had happened. We hastened toward it but ere we approached the spot,
BlIPFALO.
4S
Ihc wouiidcd
wl
iiiiifTi!(l (Vll, rolled on itHsiil*', and fxpimd. It was quit m\
t'lnu' Mr. Mr.r.i. hiid (jontim.ii' l.ra
lii'ii \V(! rcK-linl if. [ii il
II' inciin
haste jil'trr llic oflicr, and Mr. llARRrs and Mv. Sui-mii: liad
and wtTr folic
<',!!;ii Sf
)!" th.
-iM.
lollowiH}? i>nv oi tnc rnai
took I'lr.ict in the \mtU,vks of tlie animal. At this moment Mr. Suimrk'.s
horse threw him over his head Inlly ten leet : he fell <.n his powder-horn
an I was sevendy »)ruised ; he '!a!!ed to some on,^ to stop liis In.rse and was
soon on his le^^s, hut felt siek for a few mom.Mits. Friend IFarrls, who
was perfectly eool, nrared his bull, shot it throu-h (lu; lnns,'s, and it
fell dead on tlu^ spot. Mr. »km. was still in pursuit of his wonn'ded ani-
mal and Mr. Harris and Mr. Sd./iRi: joine.l and lollowed the fourth, whinh,
however, was soon out ofsi-ht. We saw Mr. Hi-.m. shoot two or thrnn
titn.-s, an.l heard -uns (in..l, either by Mr. Harris or Mr. Suihrk, but thn
weather was so hot that fearful of injuria- their horses they were
obli-ed to allow the bull they pursued to osoapc. The one shot by Mr.
Hkm,. tumbled upon his knees, jrot up a<,'ain, and rushed on one of the
lumters, who shot it oneo mor<s wlien it paused, and almost immodiatelv
The rtesh of the RulHiloes thus killed was sent to the fort in the cart, and
we continu<"d our route and passed the ni-ht on the prairie, at a spot
about half way betw;'(Mi the Yellow-Stone .and the Missouri rivers. Hero,
just before sundown, seven more bulls were dise(.v(M-ed by tlu! hunters, and
Mr. Harris. Mr. Bi:i,i, and Mr. Cui.bkrtsov each killed "one. In this' part
of the prairie we observed sev.-ra! burrows made; by the swift fox, but
could not see any of thos,> anianls all h..u-h we watched far sometime
in hopes of doinjr so. T'-ey probably scented our party and would not ap-
proach. The hunters on the prairies, either from hun-.'r or bv!cause they
hav.' not a very dc-licate appetite, sometimes break in the skull of a b- ffalo
and eat the brains raw. At siuirise we were all up, and soon had our coffee,
after which a nuilatto man called Lai-lehr, an excell m t hunter at-
tached to the American Fur-Compat.y, acc^ompanied Mr. L., .h and Mr.
IhuA. on a hunt for antelopes, as wv. wanted no mon; Bulfalocs. After
waitin- the return of the party, who came back unsuccessful, we broke
up our eanij) and turned our steps homeward.
The hulfalo bulls which have be.-n with their fair ones are at this
season wretchedly jx.or, but some of them, which appear not to have much
fondness for the latter, or may have been driven off by their riv.-Us, are
ill |)retty -ood condition. The prairies are in some places whitened with
the. skulls of the Buiralo, dri,.,! and bleached by the summer's sun and the
frosts and snows of those severe latitudes in winter. Thousands are killed
Si
If '
44
BUFFALO
merely for their tongues, and their large carcasses remain to feed the
wolves and other rapacious prowlers on the grassy wastes
A large Bison bull will generally weigh nearly two thousand pounds
and a fat cow, abour twHvc hundred. VVe wdghcd one of the bul.rk" led
by our party and lound it to reach sevont...n hundred and twenty s ,
pounds although it had already lost a good deal of blood. This U 1
old bull ..u„l was not fat ; it ha.l probably weighed n.o.-e at .o.ne p el
period. We were told that at ,his season a great n.any half-breed In
uironT ^"'''"' "'k'"""^" ^''^"'' •""" ^"""^' ^""'^ «-h ^- ^
use, on Moose river, about 200 miles north of us.
When these animals are shot at a distance of fifty or sixty yards thev
rarely, , ever, charge on the hunters. Mr. Cu...™,. told us h; S
killed as many as nine bulls from the same spot, unse.M^ by these terrible
animals. 1 here are times, however, when they have been known to gore
both horse and nder, after being severely wounded, and have dropped down
dnn,! but a few minutes afterwards. There are indeed instances of bulls
rece.vnig many balls without being immediately killed, and we saw one
which during one of our hunts was shot no less than twenty-four times be-
tore It dropped.
A bull that our party had wounded in the shoulder, and which was
thought too badly hurt to do much harm to any one, was Ibund rith r d""
gerous when we approached him, as he would dart forward at the nearest
01 his foes, and but that his wound prevents him from wheeling and turn-
uig rapidly, he would certainly have done some mischief We fired af him
rom our six-barrelled revolving pistol, which, however, seemed to have
bttle other ellect than to render him more savage and furious. His an-
pearance was well calculated to appal ,he bravest, had we not felt assured
that his strength was fast diminishing. We ourselves were a little too
con dent, and narrowly escaped being overtaken F>y hi,„ „,,„,,,, ,„, J,
pru ence We placed ourselves directly in his front, and as he adva. ced
•red at his hea.l an.I ran back, not supposing that he could overtake s-'
but he soon got within a few feet of our rear, with head lowered and'
t'veo' preparation made for giving us a hoist ; the next instant, however
we had .jumped aside, and the animal was unable to alter his headlon.^
course quick enough to avenge himself on us. Mr. Hku. „ow put a ball
rect y t roug his lungs, and with a gush of bloo<l from the mouth and
no tri s, lie h.| upon his knees and gave up the ghost, falling (as
usual) on the side, quite dead.
On another occasion, when tlie same party were hunting near the end
of the mc.,.h o, .lulv, Mr. Su.iki: wound..! a bull twice, but no blood How-
mg from the mou... it ^yas concluded the wounds were only in the flesh
BUFFALQ
45
and the animal was shot by Mr. Culbertsox. Owen McKenzie, and Mr
SuuiR., again. T.his renewed fire only seemed to enrage him the more'
and he made a dash at the hunters so sudden and unexpected, that Mr'
bdu.RE, attempting to escape, ro<h, between the beast and .t ravine whid,
was near, when the bull turned upon him, his horse became Irightened
and leaped down the bank, the Butlalo fbllowing him so closely that he
was nearly unhorsed; he lost his presence of mind and dropped his gun •
he, however, fortunately hung on by the mane and recover.-d Ips sea^
Thehon,e was the fleetest, and saved his life. He told us subsequent v'
that he had never been so terrified before. This bull was fired at several
tunes alter Squire's adventure, and was ibund to have twelve balls lod.^ed
in h.m when he was killed. He was in very bad condition, and bein.rin
the ruttmg season we found the flesh too rank for our dainlv palates and
only took the tongue with us.
Soon afterwards we killed a cow in company with many bulls and
were at first afraid that they would charge upon us, which in similar
cases they frequently do, but our party was too large and thev did not
venture near, although their angry bellowings and their unwillin.'ness to
leaxe the spot showed their rage at parting with her. As the sun was
now smk.ng fast towards the horizon on the extended prairie, we soon be-
gan to make our way toward the camping ground .u id passed within a
moderate distance of a large herd of BuHhIoes, which we did not stop to
molest but increasing our speed reach,xl our quarters ibr the ni-ht just as
tne shadows of the wester.i plain indicat, d that we should not behold
the orb of day until the morrow.
Our camp was near three conical hills called the Mamelles, onlv about
thn-ty mdes from Fort Union, although we had travelled nearly fifty by
beasts, all hands assisted in getting wood and bri.iginir water, and we
were soon ,,uietly enjoying a cup of eoflVe. The time of refreshment to
the weary hunter is always one of interest : the group of stalwart frames
stretched in various attitudes around or near the blazing watch-tire, re-
ealls to our minds the masterpieces of the great delineators of night scenes •
and we have often at such times beheld living pictures, far surpass!,,.'
any ot those contained in the galleries of Europe.
There were signs of grizzly bears around us, an<i during the nr ht we
heard a numberof wolv.-s howling among the bush.>s in the vicinity The
service berry was abun.lant and we ate a good many of them, and after a
hasty prepiiration in the morning, started again after the Bullaloes we had
seen the pre vio,.s even ng. Having rode for some time, one of our part v who
waa Ml advance as a scout, made the customary signal irom the top ..f a
*s i
■3.M
46
BUFFALO.
i 'I
if i|
i '1
-:tm
ll
h.gh h,Il. that Buffaloe^ were in sight ; this is doneby walking the hunter's
horse backward and forward several tinges. We hurried !»!„': d
oj^ seo^t ,3-.ng close to Us horse's neck, as it^.sleep on the back on^^^^^^^^^
.-nal. He ponited out where he had discovered the jrame but fh., . ■
.oneoutofsight,and(as he said) were traveHin; , Hhe h Jd 1 t!
composed ofboth bulls and cows. The hunters .no^nted'at once and l,"
lopod on n, rapul pursuit, while we Ibllovved n,ore leisurely over hills: d
phuns and across ravH.es and broken ground, at the riLf our ne ks
vh-Vr. T "" '""" "^ '''' ^""^^''•^' -"^ occasionally the BuIf"; e '
vh.ch had ta en a direction toward the Fort. At last we Cached nn^^^^^
nence fron, wh.ch we saw the hunters approaching the BuUaloes in ord •
U>eg,n the chase ,n earnest. It scenes that there is no e,i,uette a.non!
Buffalo hunters, and this not being understood beforehand Ly our friend
Harhis he was disappointed in his wish to kill a cow The country w"
not as favourable to the hunters as it was to the flying herd. The nde
.separated iron, the n,ales, and the latter turned in our direction and pled'
V lun a few undred yards of us without our being able to fire at't^.el
Indeed we wdhngly suffered them to pass unmolested, as they are always
very dangerous when they have been parted from the cows. Only one
female was killed on this occasion. On our way homeward we made
towards toe coupee, an opening in the hills, where we expected to find
water for our horses and „u,les. as our supply of Missouri water was only
enough lor ourselves. •*
The water found on these prairies is generally unfit to drink, (unless as
a matter of necessity,) and we most frequently carried eight or ten gallons
from (he nver, on our journey through the plains. We did not find water
where vye expected, and were obliged to proceed about two miles to the
eastward, where we luckily found a puddle suliicient for th<. wants of our
horses and mutes. There was not a bush in sight at this place, an.l we
collected Buffalo dung to make a fire to cook with. In the winter this
prmneiuel is often too wet to bun. and the hunters and Indians have to
eat their meat raw. It can hosvev.T hunilv I... now to our readers to hear
that they are often glad to get any thing, either raw or cooked, when in this
desolate region.
Young Buffalo bulls are sometimes castrated by the Indians, as we were
told, lor the ,,urpose of rendering ,hem larger and falter ; and we were in-^
formed, that when full grown they have been shot, an<I found to be far su-
perior to others in (he herd, in size as well as flavour. During severe
wmters the Buflaloes become very poor, and when the snox. has covered
the ground lor several months to the depth of two or three feet, they are
wretched objects to behold. They frequently in this emaciated state lose
BUFFALO.
47
Jhelr hair and become covered with scabs ; and the magpies .light on their
foIlo^I'''wh !'"' ";.-'^ T^''' "''^" ^^"-"'^^ young,was related to us, as
io bus. Whenu cal/ ,s talcen, if the person who captures it places on^ of
s fingers:,, us mouth, it will follow him aiterwarL, whetlL o„ fb o or
on horseback, for several miles
August 7th, 184.3, a Buffalo cow was killed and brought into the fort
a.ul to the astonishment of all, was Ibund to be near her time of ca vh.l
Ths was an extraordinary circumstance at that season of the year ^'
August 8th, The young Buffaloes have commenced shedding t'eir first
a man s hand. The new ha.r is dark brownish black. We caughrone
01 these calves with a lasso, and had several men to h.ld hirn u on an
proaching to pull off some of the old hair 1... k-inL- i . ^"
a. U however ,ake„.„,„e p„. p„.,, aL ^itZJl^Z'Z
cU„ e,„,„| , a. we c.uld ,,„„d|e i,, „„., „„ ,<„, „,r ,„„,^ ; ^ ^ ^
..1.1 pcU,ge. ,vl„cl, hu„s ,„ .he «i,le „i„, „„pMsi„K ,e„aohv.
Ihe proce., „f butchering or e„t,i„g „p ,he ea,ca.» o( the Duffilo is
-.erally po,,.™. i„ a slovenly and .,is,„s,i„, manned, hfu-
ami .he choices, pa,,, only are ,ave,l, unless .bod is scarce. The 1 e ' , 'd
hr,uns are eagerly sough. ,o,, and the h„,„p is excellcn. wl e, r, "e
Ihc pieces of llesh lion, the sides are called l,y the French mie., ,T
tX: " r^ ""'"°" 'r^'-" »"'"»"-"'" °"'. »^ .he ^a^ih :
hf lipped of Its covering of lat. P'^untu is
Some i,Iea of the immense number of Bisons to be still seen on the wild
pnunes, may be formed from the io. lowing account, give o,,'
K , one of the principals of the American Fur Company. " W L he
was travelling from Tra vers' Rtv t« »»,„ AT i vvnue ne
August in 'i Lt 1 • . , . ""''"' "■'*'""'" *''« ™>"th of
daTb 's ; he-;'y '-'-'. iH^ I'a.ssed through herds ol-flufialo for six
da m su ce.s.on. At another time he saw the great prairie near Fo
CU on the M.ssour. river, aln.ost blackened by these animals, which I
^X I'n ;;:.t r ' ''-' '-'-' ''- '- ^" ^" '"----- -^ p-^-
Wl...„ ih. Hi.sons first see a person, whether white or red, they trot or
.aze on h^ur loe lor a lew „,ome„,s, then take a course and go off at full
.speed untd out of night, a.ul beyond the scent of man.
h H
48
BUFFALO.
Although large, heavy, and comparativelj clumsy, the Bison is at times
hrisk and fVolicksome, and these huge iuiimals often play and gambol about,
kicking their heels in the air with surprising agility, and throwing their
hinder parts to the right and left alternately, or I'rom one side to the other,
their heels the while flying about and their tails whisking in the air. They
are very impatient in the fly and mosquito season, and are often seen kick-
ing and running against the wind to rid themselves of these tormentors.
The different Indian tribes hunt the Buffalo in various ways: some pur-
sue them on horseback and shoot them with arrows, which they point with
loading guns, (even if they have them,) but in the closely contested race
between their horse and the animal, they prefer the rifle to the bow and
arrow. Other tribes follow them with patient perseverance on foot, until
they come within shooting distance, or kill them by stratagem.
The Mandan Indians chase the Buffalo in parties of from twenty to fifty,
and each man is provided with two horses, one of which he rides, and the
other being trained expressly for the chase, is led to the place where the
Buffaloes are started. The hunters are armed with bows and arrows, their
quivers containing from thirty to fifty arrows according to the wealth of
the owner. When they come in sight of their game, they quit the )iorses
on which they have ridden, mount those led for them, ply the whip, soon
gaiu the flank or even the centre of the herd, Jind shoot their arrows into
the fattest, according to their fancy. When a Buffalo has been shot, if the
blood flows from the nose or mouth, he is considered mortally wounded j
if not, they shoot a second or a third arrow into the wounded animal.
The Buffalo, when first started by the hunters, carries his tail close •
down between the legs ; but when wounded, he switches his tail about, espe-
cially if intending to fight his pursuer, and it behooves the hunter to watch
these movements closely, as the horse will often shy, and without due care
the rider may be thrown, which when in a herd of Buffalo is almost certain
death. An arrow will kill a Buffalo instantly if it takes effect in the heart,
but if it does not reach the right spot, a dozen arrows will not even arrest one
in his course, and of the wounded, many run out of sight and are lost to the
hunter.
At times the wounded Bison turns so quickly and makes such a sudden
rush ujjon the huuter, that if the steed is not a good one and the rider per
fectly cool, they are overtaken, the horse gored and knocked down, ana
the hunter thrown off and either gored or trampled to death. But if the
horse is a fleet one, and the hunter expert, the Bison is easily outrun and
(hey escape. At best it may be said that this mode of Buffalo hunting is
^ -r--
BUFFALO.
49
riangcrous sport, and one requires both skill and nerve to come off success
fully.
The Gros Ventres, Blaekfeetand Assinaboines often take the Buffalo in
large pens, usually called parks, constructed in the following manner.
Two converging fences built of sticks logs and brushwood are made,
leading to the mouth of a pen somewhat in the shape of a funnel. The
pen itself is either square or round, according to the nature of the ground
where it is to be placed, at the narrow end of the funnel, which is always
on the verge of a sudden break or precipice in the prairie ten or fifteen feet
deep, and is made as strong as possible. When this trap is completed, a
young man very swift of foot starts at daylight, provided with a Bison's
hide and head, to cover his body and head when he approaches the herd
that is to be taken, on nearing which he bleats like a young Buffalo calf,
and makes his way slowly towards the mouth of the converging fences
leading to the pen. He repeats this cry at intervals, the Buffaloes follow
the decoy, and a dozen or move of mounted Indians at some distance behind
the herd gallop from one side to the other on both their flanks, urging them
by this means to enter the funnel, which having done, a crowd of men wo-
men and children come and assist in frightening them, and as soon as they
have fairly entered the road to the pen beneath the precipice, the disguised
Indian, still bleating occasionally, runs to the edge of the precipice, quickly
descends, and makes his escape, climbing over the barricade or fence of the
pen beneath, while the herd follow on till the leader (probably an old bull)
is forced to leap down into the pen, and is followed by the whole herd, which
is thus ensnared, and easily destroyed even by the women and children,
as there is no means of escape for them.
This method of capturing the Bison is especially resorted to in October
and November, as the hide is at that season in good condition and saleable,
and the meat can be preserved for the winter supply. When the Indians
have thus driven a herd of Buffalo into a pen, the warriors all assemble
by the side of the enclosure, the pipe is lighted, and the chiefs smoke to the
honour of the Great Spirit, to the four points of the compass, and to the
herd of Bisons. As soon as this ceremony has ended, the destruction com-
mences, guns are fired and arrows shot from every direction at the devot-
ed animals, and the whole herd is slaughtered before the Indians enter the
space where the Buffaloes have become their victims. Even the children
shoot tiny arrows at them when thus captured, and try the strength of theii
young arms upon them.
It sometimes happens, however, that the leader of the herd becomes alarm
ed and restless while driving to the precipice, and should the fence be weak,
breaks through, and the whole drove follow and escape. It also some-
VOL. n. — 7.
If!
50
BUFFALO
times occurs, that after the Bisons are in the pen, which is often so lill
ed that they touch each other, the terrified crowd swaying to and
fro, their weight against the fence breaks it down, and if the smallest
gap is made, it is immediately widened, when they dash through and
scamper off, leaving the Indians in dismay and disappointment. The side
fences for the purpose of leading the Buffaloes to the pens extend a«t
times nearly half a mile, and some of the pens cover two or three hun-
dred yards of ground. It takes much time and labour to construct one
of these great traps or snares, as the Indians sometimes have to bring
timber from a considerable distance to make the fences and render
them strong and efficient.
The Bison has several enemies : the worst is, of course, man ; then comes
the grizzly bear ; and next, the wolf. The bear follows them and succeeds
in destroying a^ood many ; the wolf hunts them in packs, and commits
great havoc among them, especially among the calves and the cows
when calving. Many Buffaloes are killed when they are struggling in the
mire on the shores of rivers where they sometimes stick fast, so that the
wolves or bears can attack them to advantage ; eating out their eyes and
devouring the unresisting animals by piecemeal.
When we were ascending the Missouri river, the first Buffaloes were
heard of near Fort Leavenworth, some having a short time before been
killed within forty miles of that place. We did not, however, see any of
these animals until we had passed Fort Croghan, but above this point we
met with them almost daily, either floating dead on the river, or gazino- at
our steamboat from the shore.
Every part of the Bison is useful to the Indians, and their method of
making boats, by stretching the raw hide over a sort of bowl-shaped frame
work, is well known. These boats are generally made by the wo-
men, and we saw some of them at the Mandan village. The horns are
made into drinking vessels, ladles, and spoons. The skins form a good
bed, or admirable covering from the cold, and the flesh is excellent food,
whether fresh or dried or made into pemmican ; the fat is reduced and
put up in bladdnrs, and in some caset. used for frv'ng fish, &c.
The hide of the Buffalo is tanned or dressed altogether by the women,
or squaws, and the children ; the process is as follows : The skin is first
hung on a post, and all the adhering flesh taken off with a bone, toothed
somewhat like a saw; this is performed by scraping the skin dov/n-
wards, and requires considerable labour. The hide is then stretched on
the ground and fastened down with pegs ; it is then allowed to remain
till dry, which is usually the case in a day or two. After it is dry-
thc flesh side is pared down with the blade of <» knife fastened in a
BUFFALO.
51
bone, called a grate, which renders the skin even and takes off about a
quarter of its thickness. The hair is taken off with the same instrument
and these operations being pcribrmed, and the skin reduced to a proper
thickness, it is covered over cither with brains, liver or grease, and left for a
night. The next day the skin is rubbed and scraped either in the sun or
by a fire, until the greasy matter has been worked into it, and it is nearly
dry ; then a cord is fastened to two poles and over this the skin is thrown,
and pulled, rubbed and worked until quite dry ; after which it is sewed to-
gether around the edges excepting at one end ; a smoke is made with rot-
ten wood in a hole dug in the earth, and the skin is suspended over it, on
sticks set up like a tripod, and thoroughly smoked, which completes the tan-
ning and renders the skin able to bear wet without losing its softness or
pliability afterwards.
Buffalo robes are dressed in the same manner, only that the hair is not
removed and they are not smoked. They are generally divided into two
parts : a strip is taken from each half on the back of the skin where the
hump was, and the two halves, or sides, are sewed together after they are
dressed, with thread made of the sinews of the animal ; which process be-
ing finished, the robe is complete and ready for market
The scrapings of the skins, we were informed, are sometimes boiled with
berries, and make a kind of jelly which is considered good food in some
cases by the Indians. The strips cut off from the skins are sewed togeth-
er and make robes for the children, or caps, mittens, shoes, «kc. The
bones are pounded fine with a large stone and boiled, the grease which
rises to the top is skimmed off and put into bladders. This is the favourite
and famous marrow grease, which is equal to butter. The sinews are used
for stringing their bows, and are a substitute for thread ; the intestines
are eaten, the shoulder-blades made into hoes, and in fact (as Wd have al-
ready stated) nothing is lost or wasted, but every portion of the animal, by
the skill and industry of the Indians, is rendered useful.
Balls are found in the stomach of the Buffalo, as in our common domes-
tic cattle.
Having heard frequent discussions respecting the breeding of the Bison
in a domesticated state, and knowing that Robert Wickliffe, Esq., of Ken
tucky, had raised some of these animals, we requested his son, then on his
way to Europe, to ask that gentleman to give us some account of their ha-
bits under his care, and shortly afterwards received a letter from him, da-
ted Lexington Nov. Oth, 1843, in which he gives an interesting account
of the Bison breeding with the common cow, and other particulars con-
nected with this animal. After expressing his desire to comply with our
request intimated to him by his son, he proceeds to give us the following
I :i|
! ' ; i
1 ':•:
r)2
BUFFALO.
I'
information : "as far," he writes, " as his limited know^f tl^eofnatural history
uiul his attention to these nninials .vill permit him to do." He proceeds:
'The herd orBiitihlo I iiowpossess havedeseeiid<'d from oncor twocows that
I purchased Iroin a niiin who broujilit them I'roin the country called the Up-
]ier Missouri ; I have had them lor about thirty years, hut Irom giviny them
away and the occasional killing ol' them by mischievous persons, as well
as other causes, my whole stock at this time does not exceed tenor twelve.
1 have sometimes conlined them in separate parks I'rorn other cattle, but
generally they herd and feed with my stock of farm cattle. They graze
in coinpany with them as gently as the others. The Buifalo cows, I think,
go with young about the same time the common cow does, and produce
once a year ; none of mine have ever had more than one at a birth. The
approach of the sexes is similar to that of the common bull and cow under
similar circumstances at all times when the cow is in heat, a period
which seems, as with the common cow, confined neither to day, nor night,
nor any particular season, and the cows bring ibrth their young of course at
dilferent times iind seasons of the year, the same as our domesticated cattle.
I do not find my Bufl'aloes more i'urious or wild than the common cattle
of the same age that graze with them.
"Although the Bufl'alo, like the domestic cow, brings fonh its young at
different seasons of the year, this I attribute « "le eifect of domestication,
as it is different with all animals in a state of nature. I have always heard
their time for calving in our latitude w\as from March until .Tuly, and it is
very obviously the season which nature assigns lor the increase of both
races, as most of my calves were from the Buffaloes and conmion cows at
this season. On getting possession of the tame Buifalo, I endeavoured to
cross them as much as I could with my common cows, to which experi-
ment I found the tame or conmion bull unwilling to accede, and he was al-
ways shy of a Buffalo cow, but the Buifalo bull was willing to breed with
the connnon cow.
" From the domestic cow I have several half breeds, one of which was h
heifer ; this I jiut with a domestic bull, and it produced ahull calf. This I
castrated, and it made a very fine steer, and when kilh>d produced very fine
beef. I bred from the same heifer several calves, and then, that the experi-
ment might be perfect, I put one of them to the Buffalo bull, and she
brought me ahull calf which I raised to be a very fim^ large animal, per-
Iifips the only one to be met with in the world of his blood, viz., a three quar-
ter, half (juarter, and half (luarter of the common blood. After makin"
these experiments, 1 have left them to propagate their breed themselves,
so that I have only had a few half breeds, and tliey always prove the same,
even bv a Buffalo bull. The full blood is not as large as the improved
BUFFALO.
£8
stock, but as large as the ordinary cattle of the country. The crossed or
half blood are larger than either the Buffalo or common cow. The hump
brisket, ribs and tongue of the full and half blooded are prclerable to thosu
ol the common beef, but the round and other parts arc nmch inferior. The
udder or bag of the Buffalo is smaller than that of the common cow, but 1
have allowed the calves of both to run with their dams upon the same pas-
ture, and those of the Buffalo were always the fattest ; and old hunters have
told me, that when a young Buffalo calf is taken, it recjuires the mijk of two
common cows to raise it. Of this I have no doubt, having received the
same information from hunters of the greatest veracity. The bag or ud-
der of the half breed is larger than that of full blooded animals, and they
would, I have no doubt, make good milkers.
" The wool of the wild Buffalo grows on their descendants when domesti-
cated, but I thiidc they have less of wool than their progenitors. The do-
mesticated Buffalo still retains the grunt of the wild animal, and is incapa-
ble of making any other noise, and they still observe the habit of having
select places within their feeding grounds to wallow in.
" The Buffalo has a much deeper shoulder than the tame ox, but is light-
er behind, lie walks more actively than the latter, and I think has more
strength than a common ox of the same weight. I have broke them to the
yoke, and found them capable of making excellent oxen ; and for draw-
ing wagons, carts, or other heavily laden vehicles on long journeys, they
would, I think, be greatly preferable to the common ox. I have as yet
had no opportunity of testing the longevity of the Buffalo, as all mine that
have died, did so from accident or were killed because they became aged.
I have some cows that are nearly twenty years old, that are healthy and
vigorous, and one of them has now a sucking calf.
" The young Buffalo calf is of a sandy red or rufous colour, and com-
mences changing to a dark brown at about six months old, which last colour
it always retains. The mixed breeds are of various colours ; I have had
them striped with black, on a gray ground like the zebra, some of them
brindled red, some pure red with white faces, and others red without any
markings of white. The mixed bloods have not only produced in my stock
from the tame and the Buffalo bull, but I have seen the half bloods repro-
ducing ; viz. : those that were the product of the common eovv and wild
Buffalo bull. I was informed that at the first settlement of the country,
cows that were considered the best for milking, were from the half blood,
down to the quarter, and even eighth of the Buffalo biood. But my experi-
ments have not satisfied me that the half Buffalo bull will prosluce
again. That the half breed heifer will be productive I'rom either race, as
I have before atated, I have tested bej'ond the possibility of a doubt.
54
BUFFALO.
"The domesticated BufTalo retains the same haughty bearing that dis-
tinguishes him in his natural state, lie will, however, feed or fatten on
whatever suits the tame cow, and requires about the same amount of
food. I have never milked either the full blood or mixed breed, but
have no doubt they might be made good milkers, although .' <'ir bags
or udders are less I ban those of the common cow; yet from the Htrength
of the calf, the dam must yield as much or even more milk than the
conuiion cow."
Since reading the above letter, we recollect tha* tlie Buffalo calves
that wert> kept at Fort Union, though well fed every day, were in
the habit of su(!king each other's ears for hours together.
There exists a singular variety of the Bison, which is however ve-y
scarce, and the skin of which is called by both the hunters and I'ur
traders fi " l)caver robe." These are valued so highly that some have
sold for more than three hundred dollars. Of this variety Mr. Cui,-
iiERTsoN had the goodness to ])resent us with n superb specimen,
which we had lined with cloth, and find a most excellent del'ence
against the cold, whilst driving in our wagon during the severity of
our northern winters.
GEOGRAPIIICAL DISTRIBUTION.
I
The range of the l]ison is still very extensive ; but although it was
once met with on the Atlantic coast, it has, like many others, receded
and gone west and south, driven onward by the march of civilization
and the advance of the axe and plough. His habits, as we have seen,
are migrator,, iv.u the extreme northern and southern limits of the wan-
dering herds not exactly defined. Authors state, that at the time of the
first settlement of Canada it was not known in that country, and
Sagabd TiiEODAT mentions having heard that bulls existed in the far west,
but saw none himself According to Dr. Uichardsom, Great Slave Lake,
latitude 00°, was at one time the northern boundary of their range;
but of late years, according to the Ic^stimony of the natives, they have
taken possession of the flat limestone district of Slave Point on the north
side ot' that lake, and have wandered to the vicinity of Great Marten
Lake, in Latitude 03° or 04°. The Bison was not known formerly to
the north of the Columbia river on the Pacific coast, and Lewis and
Ci.ARK foniui Btillalo robes were an important article of traffic between
the inhabit.'mts of the east side and those w^est of the Iloeky mountains.
The Bison is spoken of by Hernandez as being found in New Spain
or Mexico, and it probably extended farther south. Lawson speaks of
BUFFALO.
65
two Buffalops that, were killed in one sea^■.<)n on Cape Fear river, In
North Carolina. The Bison formerly existed in South Carolina on the
seaboard, and we wore informed that from the last herd seen in that State
two we ; kill.id in the vicinity of Columbia. It thus appears that at one
period this animal ranged over nearly the whole of North America.
At the present time, the Buiraio is found in vast herds i.i some of the
great prairies, and scattered more sparsely nearly over the whole length
and breadth of the valleys east and .vest that adjoin the Rocky Moun-
tain chain
Ki-
56
PUTOIIIUS ERMINEA.— Linn
White Weasel. — Stoat.
PLATE LIX— Male and Fbmale in summer peliige.
P Hycmc alba ; aistate supra rutila, infra alba caudae apice nigro.
CHARACTERS.
White, in winter ; in summer, brown above, white beneath ; tip of the tail,
black.
H
«
«
tl
SYIiONyMES.
MusTELA Erminea, Briss. R^gne An., p. 243, 2.
" Linn., Syst. Nat., 12. i., p. 08. 7.
" Schrch., Stiugtli., p. 4i»0, 11 t. 137.
" " Er.xlobon Syst., p. 474, 13.
ViVEKA EuMiNEA, Sliiiw, Gen. Zool., i., 2 p. 4i;C t. 9!>.
" " Pcnniint, Arctic Zooloiry, i., p. 7;,,
Hermine, Buffon, C. C, p. 240, t.
MusTELA Erminea, Parry's First Voyage, Sup. 135.
" " Parry's Second Voy., App. 294.
" Franlvlin's Fir.'^t Journey, p. 052.
Godman, Ame. Nat. Hist., vol. i., p. 103, fig. 1.
" Harlan, p. 02.
PuTORius N0VEBORACEN8IS, Dekay, Nat. Hist. New-Yorl;, p. 36.
description.
Body, long and .slender, with a convex nose and forehead ; limbs, short,
and rather stout ; tail, long and cylindrical ; moustaches, long, extending
beyond the ears; ears, low, br.)ad and round, do not entirely surround the
auditory opening, sparingly covered with short hairs on both surfaces.
There are five toes on each foot, the inner toe much the shortest ; the
toes are clothed with hairs, covering the nails ; fur, soft and short ; tail,
hnir)-, and bushy at the end. There are two glands situated on each side
ofthe under surface ofthe tail, which contain an offensive white muskv
fluid.
WHITE WEASEL
•5?
COLOUR.
In winter, in fl.e latitude of Pennsylvania and Now- York, a 1 iho hairs
are snowy white Iron. th,> roots, exeept those on the end of the tail, which
forahout one and three-fourth inches is black. We received specimens irom
Vn-ginia obtained in Jaiiuary, in which the colours on the back had inirtcr-
poiH! no chanfT.', and re.nain.ul brown ; rtnd from the upper and michlle iis-
tricls of South Carolina kilh-.l at the same period, when no change had taken
place, and it was stated that this, the only species of Weasel touted theie
remaine.1 brown through the whole year. These specimens are now in our'
possession, and we have arrived at the conclusion that the farther South wo
Jidv,in.;e, (he less perfect is the chan-e from brown to white. We hive spe-
cimens from Lonj? Island, obtained in winter, which retain shades of brown
on the head and dorsal line. Those liom the valleys of the Vir^-inia
mountains have broad stripes of brown on Ihe back, and specimens Irom Ab-
bcnilh; and I.exington, S. Carolina, have not undergone the slightest change.
We wore informed by our friend Mr. BRoMPiELn an eminent botanist of
England, that in the Isle of Wight, the place of his residence, the Ermine
underwent only a partial change in winter.
In summei, the upper surlace of the body is of a chesnut-browii colour,
a little darker on th.; dorsal line ; under surface, the upper lips to the
nose, chin, throat, inner surfr.ces of legs, and belly, whice ; the line sepa-
rating the colour ofthe back from that on the under surface, is very dis-
tinct, but irregular, and in some specimens, the white on the belly extends
further up along the sides than in others. Whiskers white and black j
the former preponderating: end of tail, as in winter, black.
DIMENSIONS.
Old male.
Nose to root of tail, - - . .
Tail (vertebnr), - - . . .
" to end of hair, ....
Stretch of legs from end, to end of claws,
Length of hind foot, to end of nails,
" lore-foot, to " »
Black tip of tail, - - . .
VOL II. — S
InehiM,
7
1*
14
14
3
b IHi
I* ' 1 1
' 11
^',(«
58
WHITE WEASEL.
»
The name of Ermine is associated with the pride of state and Inxurj'
its fur liaving from lime immemorial been the favourite ornament of the
robes of princes, judges and prelates. From its snowy whiteness it is
emblematic of the purity which they ought to possess.
To us the Ermine, in its winter dress, has always appeared strikingly
beautiful. On a wintry day, when the earth was covered with a broad
sheet of snow, our attention has sometimes been arrested by this little ani-
mal peering out from a log heap, or the crevices of a stone fence ; its eyes
in certain sh:ides of light appearing like sapphires, its colour vicing in white-
ness and brilliancy with the snowy mantle of the surrounding landscape.
Graceful in form, rapid in his movements, and of untiring industry,
he is withal a brave and fearless little fellow; conscious of security
within the windings of his retreat among the logs, or heap of stones,
he permits us to approach him to within a few feet, then suddenly with-
draws his head ; we remain still lor a moment, and he once more re-
turns to his post of observation, watching curiously our every motion,
seeming willing to claim association so long as we abstain from becoming
his persecutor.
Yet with all these external attractions, this little Weasel is fierce and
bloodthirsty, possessing an intuitive propensity to destroy every animaJ
and bird within its reach, some of which, such as the American rabbit,
the ruded grouse, and domestic fowl, are ten times its own size. It is u
notorious and hated depredator of the poultry house, and we have known
forty well grown fowls to have been killed in on<; night by a single Er-
mine. Satiated with the blood of probablj- a single fowl, the rest, like
the flock slaughtered by the wolf in thr; shcepfold, were destroyed in obe-
dience to a law of nature, an instinctive propniisify to kill. We have
traced the footsteps of this bloodsucking little animal on the snow, pur-
suing the trail of the American rabbit, and although it could not overtake
its prey by superior speed, yet the timid hare soon took refug<' in the hoi
low of a tree, or in a hole dug by the marmot, or skunk. Thither it was
pursued by the Ermine, and destroyed, the skin and other remains at the
mouth of the burrow bearing evidence of the fact. W<' observed an Er-
mine, after liiivinn' captured a hare of the above spcM-ies, first behead it and
then drag the body some twenty yards over the fresh fallen snow, be-
neath whi(-h it w;is coneeah'd, and the snow tiiihtly pressed over it; the
little prowler displaying thereby a habit of which we became aware for
the first time on that occasion. To .avoid a dog that was in close pursuit,
1^?^
WmTE WEASEl..
o9
.t mounted a tree and kid itself flat on a limb '^bout twenty x''eet from
the ground, from which it was finally shot. We have ascertained by
successful expcrirnonts, repeated more than a hundred times, that the
Ermine can be employed, in the manner of the ferret of Europe, in
driving our American ral)l)it from the burrow into which it has retreat-
ed. In one instance, the Ermine employed had been captured only a
few days before, and its canine teeth were filed in order to prevent its
destroying the rabbit ; a cord was placed around its neck to secure
its return. It pursued fhe hare tlirough all the windings of its burrow
and forced it to the moutli, where it could be taken in a net, or by the
hand. In winter, after a snow storm, the rufi'ed grouse has a habit of
plunging into the loose snow where it remains at times lor one or
two days. In this passive state the Ermine sometimes detects and de-
.stroys it. In an unsuccessful attempt at domesticating this grouse by
fastening its feet to a board in the mode adopted with the stool pigeon,
and placing it high on a shelf, an Ermine which we had kept as a i)ct,'
I'oinid its way by the curtains of the window and put an end to our
experiment by eating off the head of our grouse.
Notwithstanding all these mischievous .and destructive habits, it is
doubtful whether the Ermine is not rather a benefactor than an enemy
to the farmer, ridding his granaries and fields of many depredators
on the product of his labour, that would devour ten times the value
of the poultry and eggs which, at long and uncertain intervals, it
occasionally destroys. A mission appears to have been assigned it
by Providence to lessen the rapidly multiplying number of mice of
various species and the smaller rodentia.
The white-tooted mouse is destructive to the grains in the wheal
fields ai d in the stacks, as w ell as the nurseries of fruit trees. Le Co.nte's
pine-mouse is injurious io the Irish and sweet potato crops, causing
more to rot by nibbling holes into them than it consumes, and Wilson's
meadow-mouse lessens om- animal product of hay by f.M'ding on the
grasses, and by its long and tortuous gaUeries among their roots.
Wherever an Ermine has taken up its n^sidence, the mice in its vicin-
ity for half a, mile round have been found rapidly to diminish in nmn-
ber. Their active little enemy is able to force its thin vermiform body
into the burrows, it tollows them to the end of their galleries, and destroys
whole families. We have on several occasions, r.fler a light snow, fol-
lowed the trail of this weasel thnuigh li.-lds and .uendows, and witnessed
the immense destruction which it occasioned ir. a shigle night. It enters
every hole under stumps, logs, stone heaps j-nd fences, and evidences of
its bloody deeds are seen in the mutilated rcm.ains nf the mice scattered
I •■
> I
bO
WHITE WEASEK
on the snow. The little chipping or ground s(,uirre!, Tamias Lysteri, takes
up its residence in the vicinity of the grain fields, and is known to car-
ry off in its cheek pouches vast quantities of wheat and buckwheat, to
serve as winter stores. The Ermine instinctively discovers tliese snug'rc-
treats, and in (he space of a few minutes destroys a whole family ol
these beautiful little TniniiB ; without even resting awhile until it has con-
sumed its now abundant food its appetite craving for more blood, as if
impelled by an irresistible destiny it proceeds in search of other objects
on which it may glut its insatiable vampire-like thirst. The Norway rat
and the common house-mouse take possession of our barns, wheat stacks,
and granaries, and destroy vast (juantities of grain. In some instances
the farmer is reluctantly compelled to pay even more than a tithe in con-
tributions towards the support of these pests. Let however an Ermine
find its way into these barns and granaries, and there take up its winter resi-
dence, and the havoc which is made among the rats and mice will soon
be observable. The Ermine pursues them to their farthest retreats, and in
a few weeks the premises are entirely free from their depredations
We once placed a half domesticated Ermine in an outhouse infested with
rats, shutting up the holes on the outside to prevent their escape. The
little animal soon commenced his work of destruction. The squeakin"
of the rats was heard throughout the day. In the evening, it came
out hcking its mouth, and seeming like a hound after a long chase
much fatigued. Aboard of the lloor was raised to enable us to ascer-
tain the result of our experiment, and an immense number of rats were
observed, which, although they had been killed on different parts of the
l)uil(ling, had been dragged together, forming a compact heap.
The Ermine is then of immense benefit to the farmer. We are of
the opinion that it has been over-hated and too indiscriminately perse-
cut(-(l. If detected in the poultry house, there is som.. excuse for de-
stroying it. as, like the dog that has once been caught in the sheepH.ld,
It may return to connnit farther depredations; but when it has taken
up its residence under stone heaps audiences, in his fields, or his barns
the farmer would consult his interest by suffering it to remain as by
thus inviting it to a home, it will probably destroy more forinidable
enemies, relieve him from many petty annoyances, and save him many
a bushel of grain.
Let us not too hastily condemn the little Ermine lor it;^ bloodthirsty
propensities. It possesses well-developed canine teeth, and obeys an in'-
stinet of nature. Man, with organs not so decidedly carnivorous, and
possessed ol the restraining powers of reason and conscience, often com-
mits a wanton havoc on the interior animal*, not so much from want of
WHITE WEASEL.
61
food, as from a mere love of sport. The bufTalo and the elk he has
driven across the Mississippi, and their haunts are now restricted to the
prairies of the far West. Even now thousands are slaughtered for
amusement, and their tongues only are used, whilst their carcasses are
left to the wolves. Iln fills his g;imo bag with more woodcock, par-
tridges and snipe, tlian he requires; his lishing-rod does not remain idle
even after he has provided a full meal for his whole family ; and our
youngsters are taught to shoot the little warbler and the sparrow as
a preparatory training for the destruction of larger game.
The Ermine is far from being shy in its habits. It is not easily
alarmed, and becomes tolerably tame when taken young, for we have
on several occasions succeeded in our attempts at domesticating it, but;
it appeared to us that these pets were not quite as gentle as many
ferrets that we have seen in Eurojjc. When not kept in confinement,
they were apt to stray ofl' into the fields and woods, and finally be-
came wild. The tracks of this species on the snow are peculiar, exhibit-
ing only two footprints, placed near each other, the succeeding tracks
being far removed, giving evidences of long leaps. We have frequenti}
observed where it had made long galleries in the deep snow for tw(Mitv
or thirty yards, and thus in going from one burrow to another, instead ot
travelling over the surface, it had constructed for itself a kind of tunnel
beneath.
The Ermine is easily taken in any kind of trap. We have on seve-
ral occasions, when observing one peeping at us from its secure hole in
the wall, kept it gazing until a servant brought a box trap baited
with a bird or piece of meat, which was placed within a few feet of its
retreat. The Ermine, after eyeing the trap for a few moments, gradujilly
approached it, then after two or three hasty springs backwirds returned
stealthily into the trap, seized the bait, and was caught. We find in our
note-book the following memorandum : "On the lOlh .Tune, 18 Ki, we baited
a large wire trap with maize : on visiting the trap on the following day
we found it had caught seven young rats and a Weasel ; the throats of
the former had all been cut by the Weasel, and their blood sucked ; but
what appeared strange to us, the Weasel itself was also dead. Th( .-Mts
had been attracted by the bait : the Weasel went into the trap and killed
them ; and whether it met its death by excessive gluttony, or from a wound
inflicted by its host of enemies, we are unable to determine.
This s])eoies does not appear to be very abundant any where. We have
seldom found mori" than two or three on any farm in the Northern or
Eastern States, We have ascertained that the immense number of tracks
often seen in the snow in particuhir localities were made by a single ani-
•! liil
65^
WHITE WEASEl..
Hi
m
mal, as by capturing one, no signs of other individuals .vere afterwards
seen. We have observed it most Jibundant in stony regions : in Dutchess
and Ontario counties in New-Yoriv, on the iiills of Connecticut and Ver-
mont, and at the foot of the AHeghanies in Pennsylvania and Virginia. It
is solitiiry in its habits. ;.s w(> have seldom seen a ]r.m togi'ther except
in the rutting season. A family of yoUng, however, are aj,t"to n-main in
the same locality till autumn. In winter they separate, and we are in-
clined to think that they do not hunt in couples or in packs like the wolf,
but that, like the bat and the mink, each individual pursues its prey with-
out copartnership, and hunts ibr its own benelit.
The only note we have ever heard uttere.l by the Ermine is a shrill
•luerulous cry: this ^v as heard only when it was suddenly alarmed or
received a hurt, when its sharp scream was always alt.Muled with' an
emission of the offensive odour with which nature has furnished it a^'
a means of defence. Although nocturnal in its habits, the Ermine is fre-
<iuently met with at all hours of the day, and we have seen it in pur-
suit of the common rabbit und.'r a bright shining sun at noon-day
We doubt whether the Ermine ever digs' its own burrows, and although
when fast..ned to a chain in a state of connnement we observed it dig-
ging shallow holes in the ground, its attemj)ts at burrowing were as
awkward as those of the rat ; the nests we have seen were jilaced un-
<ler roofs of trees, in stone heaps, or in the burrows of the ground squir-
rel, from which the original occupants had been expelled. The rut-
ting season is in winter, from the middle of February to the beginning
of March. The young, from four to seven, are born in May, in the
latitude of New-York. We were informed by a close ohserveV, that in
the upper country of Carolina, the young had been seen as early as
the 2rnh of March. The colour of the young when a week old, is
pale yellow on the upper surface.
The Ermine avoids water, and if forcibly thrown into it, swims awk-
wardly like a cat. It does not, like the fi.sher and pine marten, pursn..
its prey on trees, and seems never to ascend them from choice ; but from
dire necessity, when closely pursued by its implacable enemy, the do-
One of the most singular characteristics of this species, viz.,"its change
of colour Irom brown in summer to pure white in winter! and from
white in spring to its summer colour, remains to be consideivd. It is
well known that about the middle of Oet(.ber the Ermine gradual 1\
loses its brown summer-eoat and assumes its white winter-pelage, whicl",
about the mid.lle of March is replaced by the usual summer 'colour-
As far as our observations have enabled us to form an opinion on
this subject, we have arrived at the conclusion, that the animal sheds
WHITE WEASEL.
68
itb coat twice a year, i. e., at the periods wiien these sei ii-aiinual changea
take place. In autumn, the suuiiiier hair gradually and almost imper-
ceptibly drops out, and is succeeded by a fresh coat of hair, which in the
course of two or three weeks becomes pure white ; while in the spring
tlie animal imdcrgotis its change from wiiite to brown in consequence
of shedding its winter coat, the new hairs then coming out brown. We
have in our jjossession a specimen captured in November, in which the
change ol" colour has eonsidenibly advanced, but is not com[)leted. The
whole of the under surface, the sides, neck and body to within half an inch
of the back, together with the legs, are white, as well as the edges of
the ears. On the upper surface, the nose, forehead, neck, and an ir-
regular line on the back, together with a spot on the outer surface of
the fore-leg, are brown, showing that these parts change colour last.
In reference to the change of pelage and colour as exhibited in spring,
we add some notes made by the senior author of this work, in March,
184'2, on a specimen sent to him alive by Oc.in.s Hammond, Esq.
The Weasel this evening, the 6th of March, began to show a change of
colour ; we were surprised to see that all around its nose, the white; hair
of its winter dress had changed suddenly to a silky black hue, and
this extended to nearly between the ears. Here and there also were
seen small spots of black about its rump, becoming iriore appare?it toward
the shoulders, and forming as it were a ridge along the back of the animal.
March lOth. By noon the change was wonderfully manifested. The
whoh; upper surface of the head had become black to the eye, as
well as the ridge of the back, the latter part having become' quite
clouded, and showing an indescribable motley mixture of closely-blended
white, black, and blackish brown.
18th. This day the change of colour reached the root of the tail,
where it formed a ring of about one inch, of the same reddish blark colour.
All other parts remained white, slightly tinged with pale lemon colour. Ix '
fed, as we perceived, more voraciously than ever since we have had it
in our possession. No less than three or four mice were devoured to-day,
and what is very strange, it left no remains of either hair, skull, feet, or
any other part of these animals; and on this day, the 18th of Mr.rch,
it ate a very large piece of fresh beef, weighing nearly half a pound.
inth. Last night our Weasel made great progress, for this morning
we found the coloured ridge on the back broader and less mottled. The
!)osteri<)r eoloureil part of the head had .joined the ridge ol" the back.
The posterior part of the hind legs had beeouK; brown, aiici we ob-
served a small spot the s\/.v ol' a sixpence on each upper part of the
thighs. At this juncture we think the ar.imal is beautiful.
1.1
64
WHITE WEASEL.
22(1. This morniiig we (buiul all the white hair on the outward ridp;e
of the back had fallen, and portions of the thighs and shoulders had
become broader ; the coloured parts were of a rich brown to the very
nose, and there existed indications of small dark spots coming from
the sides of the belly, somewhat like so many beads strung on a thread,
separatee from the lower edge of the back ridge by a line of white
of al)()ut half an ineli. The weasel continues as lively as ever.
When asleep, it curls its body around, and the tail encircles the whole
animal, the end covering the nose. The eyes appear to be kept care-
fully uncovered. The general tints of the coloured parts of this Wea-
sel were very much darker than in any other specimen which we have
in our collection. When angry, it emitted a sharp shrill cry, and snapped
with all its might at the objects presented to it. It was very cleanly
in its habits, never rendering its sleeping apartment disagreeable.
28th. Our Weasel got out of its cage by pushing the wires apart,
passing through an aperture not exceeding five-eighths of an inch, as we
suppose by putting its head diagonally through the bars. The door and
windows of our room were closed, however, and, when we entered, our
little fellow looked at us as if well acquainted, but soon ran behind a
box. It devoured last night at least half a pound of beef, kept in the
room for its day's ration. We placed the cage, with the door open, on
the floor, and by walking round the box that concealed it, the animal
was induced to run towards the cage, and was again secured in it.
We have often observed this species whilst retreating ; if near its
place of concealment, it does so backwards, and we observed the same
movement when it passed iVoni one section of its cage to the other, drag-
ging its food and concealing it among the straw. While we were sitting
at a distance from its retreat, it proceeded by leaps very swiftly to with-
in two or three feet of us, when it suddenly threw itself round and re-
treated backward, as mentioned before.
The purplish brown was now augmented on the thighs and shoulders to the
knee joints, no white hairs remaining mixed with those that were coloured.
Beneath the jaws, separate small brown spots appeared at equal distances,
leaving an intermediate space of white, as was the case along the flanks.
The root of the tail had acquired no farther change. Since last week our
animal has diflused a very strong disagreeable odour, musky and fetid,
which may be attributable to this being its breeding season ; we observed
that I lie smell was more disagreeable in the n>ornings and evenings, than
at mid-day.
April. — t »!! |)aying our accustomed visit to our Weasel this evening,
we i'ound it d' ad, which put a stop to any further observation of its habits
Its measurements nro as follows :
WHITE WEASEL. g^
From point of nose to end of tail, .... lyi
Tail (vertebrae), --..... 5
Tail to end of hair, .-.-... g
Height of ear, 1
Fore claws and hind claws stretching out to the black hair
of the tail, j^i
OBOGRAPHICAL DISTRIBUTION
If, as we feel confident after having examined more than a hundred
specimens from both continents, the American Ermine is identical with
that of Europe, it will be found un have the widest range of any quadruped
at present known. It exists in ihe colder portions of Asia, and in the
temperate, as well as in all the Northern States of Europe. We have seen
specimens from England and Scotland, from France, Germany, Switzer-
land, Denmark, Sweden, and Russia.
In America, its geographical range is also very extensive. Dr. Dekav
(see Fauna, N. Y., p. 37) supposes it to be a northern animal, found as
far south as Pennsylvania. We agree with him in his supposition that it
is a northern animal, as it is only found in the Southern States where the
country is mountainous or considerably elevated. It exists in the polar re-
gions of Ama-ica as far north as Franklin, Parry, UicHARDsoy, Lyon and
other explorers were able to penetrate. It is found in Nova Scotia and
Canada, and in all the Eastern and Northern States. We observed it
along the whole chain of mountains in Virginia and North Carolina. We
obtained a specimen from Abbeville in South Carolina, from our friend
Dr. Barrett, a close observer and a good naturalist ; and another from
Mr. Fisher, from Orangeburg District. We have ascertained that it
exists in the mountains of Georgia, where we are penning this article.
We saw a specimen procured by To^nsend in Oregon, and have heard of
its existence in North Calif-:. ua. It is, however, not found in the maritime
districts of any of the Southern States, and in Carolina and Georgia does
not approach within fifty miles of the seaboard ; and even when it exists
on the most elevated portions of country, it is, like the ruffed grouse in
similar localities, a rare species.
11
II
tit' I
GENERAL REMARK8.
Writers on Natural History, up to the time of Harlan, Godman and
Richardson, without having instituted very close comparisons, considered
VOL. 11.
i ! II
ee
WHITE WEASEL.
the spec.es existing in Asia. Europe and America, to be identical. Al
a somewhat later period, however, naturalists, discovering on patient and
close mv'estigation that nearly all our species of quadrupeds as well as
birds differed from the closely allied species on the eastern continent
began to doubt the identity of the Ermine existing in Europe and Ameri-'
ca. We have been unable to ascertai.i whether these doubts ori-^i-
nated from any difference in specimens from these countries, or from%
bel.ef that so small an animal could scarcely be found on both con-
tments, and thus prove an exception to a general rule. We admit that
were an animal restricted to the temperate climates on cither continent
and not found in the polar regions, there would be a strong presump-'
tive argument against the identity of closely allied species existing in
Europe and America. The Ennlne of the eastern continent is known
to exist where the two continents nearly approach each other, perhaps
occasmnally have been united by a solid bridge of ice, and probably
may be so again during some of the coldest seasons of the polar winters
aPd being capable of travelling on the snow, and resisting the severest
cold, this animal is fully able to cross from one continent to the
other, like the white bear, or Arctic fox, species which are admitted as
Identical on both continents. Our species, moreover, is kn ^n to exist
equally far north, and has been traced nearer to the poles than even the
musk-ox.
We observed, in the Museum of the Zoological Society, that the speci-
men brought by Richardson was regarded as a new species by C. L
Bonaparte, Esq., (now Prince of Muisignano.)
In the recent work of Dr. Dekav, we perceive it has been described
as a new specie^ under the Uixme of Putorius Novcboracensis. In a spirit
of great fairness and candour, however, he states: " I have never seen
the true Ermine in its summer dress, and only know it from Pennant's
description : ears edged with white ; head, back, sides and legs, pale taw-
ny brown; under side of the body white; lower part of the tail brown end
black." The only point of difference, then, is in the ears .nlged with
white. Pennant's specimen unquestionably was obtained at the period
of time when the animal had only partially changed colour, as in all
these cases the specimens before us, both from Europe and America, have
Iheir ears edged with white. We have compared a great number of spe-
cimens from both continents, and have several of each lying before us ; the
edges of the ears in summer colour are all brown, and neither in size, den
tition, nor colour, can we observe a shade of diffirence.
Li
m
1
m
1
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A.L
i'iiiL(< l.\lll
I! S
iV. .■'Kini- IwWK llil-ticork
( /-.///(/r / , ///,f/- ////,//,,
r
''wwi; 'i\-<m Natui;: ' ■.,' ,' *mi!4! jt:.''I'
I
I
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'
SCIURUS SUB-AURATUS.— Bach.
OrANOE - BELLIED SaUIRREL. GoLDEN - BELLIED SqUIRREL.
S. Magnitudine, S. migraiorium superaens, S. Carolinensi cedens ;
supra cinereus flavido-undutus, subtus saturate aureus, cauda corpora
longiore. *
CHARACTERS.
Size intermediate between the Northern gray and the little Carolina
squirrel; tail longer than the body ; colour, above, gray, unth a wash of yel-
low ; beneath, deep golden yellow.
SYNONYME.
OoLDEN-BELUED Squirrel, Sciutus Sub-auratus. — Bachman, Mon. Genus Sciui-us,
p. 12.
DESCRIPTION.
In the two specimens now before us, which arc very similar in size and
markings, there is no appearance of the small anterior upper molar found in
several other species of this genus. We conclude, therefore, that it either
does not exist at all, or drops out at a veiy early period ; and accordingly
set down this species as having only twenty teeth, viz. :
. . 8 <*—
Incisive - ; Canine — - ; Molar
9 0—0 '
:20.
The upper incisors are of moderate size ; their colour is deep orange
brown ; the lower incisors are a little paler ; head, of medium size ; ears
short and pointed, clothed with hair on both surfaces, ''"he body seems
more formed for sprightliness and agility than that of the small Caro-
lina Squirrel, and in this respect comes nearest to tlie northern gray squir-
rel. The tail is long, and nearly as broad as that of the last rianied
ypecies.
68
ORiVNGE-BELLIED SQUIRREL.
COLOUR.
The whole upper surface gray, with a distinct yellow wash. The
hairs which give this outward appearance are grayish slate colour at
their base, then broadly annulated with yellowish, then black, and near
the tips annulated with yellowish-white ; sides of the face and neck,
the whole of the inner side of the limbs, feet, and the under parts, deep
golden yellow ; on the cheeks and sides of the neck, however, the hairs
are obscurely annulated with black and whitish ; the ears are well clothed
on both surfaces with tolerably long hair of the same deep golaen hue
as the sides of the face ; hairs of the feet mostly blackish at the root,
some obscurely tipped with black ; hairs of the tail, black at the root, and
the remaining portion bright rusty yellow; each hair annulated with
black three times ; the under surface of the tail is chiefly bright rusty yel-
low ; whiskers, longer than the head, black.
DIMENSIONS.
Inches.
LlllM.
10
(i
1)
2
12
1
7
2
7
7
5
8
6
" of tail, (vertebrae,)
" including fur,
of palm to end of middle fore-claw, -
of heel to point of middle nail, -
" of fur on the back,
Height of ear posteriorly, - - . .
Breadth of tail with hair extended.
Weight U lbs.
IIABITS.
During the winter season the city of New-Orleans is thronged by na
lives of almost every land, and the Levee (which is an embankment ex-
tending along the margin oi the river) presents a scene so unlike any-
thing American, that as we walk along its smooth surface we m.iy inin-
gine ourselves in some twenty difl'erent countries, as our eyes fall upon
many a strange costume, whose wearer has come from afar, and is, like
ourselves, perchance, intent on seeing the curiosities of this Salnuigiindi
city. Here a Spnnish gentleman from Cuba, or a Mexican, next a pirate
or thief, perhaps, from the same countries; all Europe is here represented,
and the languages of many parts of the world can be heanl whilst walk-
Ing even half a mile; the ''escendants of Africa are h.^re metamorphosed
ORANGE-BELLIED SQUIRREL.
69
into French folks, and the gay bandanna that turbans the heads of the co-
loured women, is always adjusted with good taste, and is their favourite
But the most interesting figures are the few straggling Choctaw and
Chickasaw Indians who bring a variety of game to the markets, and in
their blankets, red flannel leggings, moccasins and bead finery, form a
sort of dirly picturesque feature in the motley scene, and generally attract
the artist's eye : many of these Indians have well formed legs and bodies,
and their half-covered shoulders display a strength and symmetry indica-
ting almost a perfect development of the manly I'orm — their sinews
and muscles being as large as is compatible with activity and grace.
Whilst conversing with one of these remnants of a once numerous race,
it was our good fortune to see for the first time the singular and beau-
tiful little Orange-bellied Squirrel which the Indian hunter had brought
with him along with other animals for sale, having procured it in the
recesses of the forest on the borders of an extensive swamj).
Rarely indeed does the Orange-bellied Squirrel leove its solitary haunts
and quit the cypress or sweet-gum shades, except to feed upon pecan-
nuts, berries, persimmons, or other delicacies growing in the ujjlands ; and
it does not hoard up the small acorn from the swamp-oak until late in
the autumn, knowing that the mild winters of Louisiana are seldom
cold enough to prevent it from catching an unlucky beetle from time
to time during the middle of the day, or interfere with searches (or
food among tiie dry leaves and decaying vegetable substances in the
woods. Besides, early in the year the red-inaple buds will alford a treat
to which this little squirrel turns with as much eagerness as the horst
that has been kept all winter upon hay and corn, dashes into a fine fiel/
oi" grass in the month of May.
The hole inhal)ited by the present species is generally in some tal
tree growing in the swamp, and perhaps sixty or one hundred yard^
from the dry land, and the animal passes to it from tree to tree, o'
along some fallen monarch of the woods, over the shallow watei
keeping his large eye bent upon the surrounding Innds in fejir of souk-
rnemy ; nnd, in fiiith, he runs no liltle risk, for should the red-slu;-!)-
dered liawk, or the sharped-shinned, dnrt upon him, h(> is an easy prev:
or, on a warm d^y, a snake, called the " Wiitcr moccasin," cm-led up in
his way, might swallow him, "t.'til and all." Hut good fun it nuist be
to see the sportsman following in pursuit, splashing and floundering
through the water, sometimes half-leg deej), and at others only up to
the ankles, but stumbling occasionally, and n)aking the "water fly;"
70
ORANGE-BELUED S(iUIRREL
so that when he has a chance to pull trigger, he is certain to snap both
barrels !
Of the breeding of this species we know nothing, nor can we say more
of its habits, which are yet to be farther investigated.
GEOGRAPHICAL DISTRIBUTION.
We have not heard of the occurrence of this species farther north
than Louisiana, and think it probable its range will be found to ex-
fend west and south of that state into Teixas, and perhaps Mexico.
71
PUTOEIUS FRENATA.-LioiEr.
Bridled Weasel.
PLATE LX.— Males.
P. magnitudine P. erminefB, supra fulvus, infra ex flavicante alDU8 •
naso, dorso, majore capitis parte, auribusque nigris; macula inter aures
et vitta frontali albis.
CHARACTERS.
Size of the ermine ; none, back part of the head, and ears, black ; a white
spot between the ears, and a band over the forehead, ivhite ; yellowish-brown
above, yellowish-white beneath.
SYNONYMS.
MusTELA Fre-ata Lichtenstein. Dar.tellung neuer oder wenig bekanntcr Seluge-
thiere XLIL, Tafel. Berlin, 1827-1834. "
DESCRIPTION.
This species in form bears a considerable resemblance to the Ermine
of the more northern parts of America. It is however rather stouter, the
nock shorter, the ears narrower and higher, and the tail a little longer.
In its dentition it is also similar to the common weasel, being a true pw-
torius, with thirty.four teeth, having only four molars on each side of
the upper jaw, and five beneath, whilst the genus Mustela is characterized
by having thirty-eight teeth, five on each side of the upper jaw, and six
beneath. The ears and tail are clothed with hair, the fur is a little shorter
and slightly coarser than that of the Ermine.
COLOUR.
Moustaches, ears on both urfaces, nose, and around the eyes black •
a broa.l band of white rises in the forehead above the nose, extending
aroun.1 the head between the eyes and ears, reaching the neck and throat
.neluilinsi the .-hin, the colours of which as well as the inner surfaces
of the l«re.|egs are white ; there is also a white spot on the back of the
head between the ears. The colour is dark brownish !!!a<^k from the
72
DRIDLED WRASEL.
neck, reaching the white bund on the forehead, where the lines of scptb
ration are distinctly but irregularly j)reserved. On the under surface from
the chest fo the tail including tlu^ inner surface of the thighs, a light
fawn colour; tail, the colour of the back till within an inch of the
tip, where it gradually darkens into black. The black at the end of
the tail id not only shorter but less distinct than the corresponding parts
on the ermine in summer colour.
'J'lie colour of the l)ack and outer surfaces of the legs is light yel-
lowish brown, gradually darkening on the neck till it reaches and blends
with the dark brown colours on the hind head.
DIMENSIONS.
From point of nose to root of tail,
Tail (vertebra'),
Do. to end of hair, ...
Height of ear, ...
From heel to end of longest nail,
Incbaa.
11
ft
6
H
1?
HABITS.
We have personally no knowledge of the habits of this rare and com-
paratively new species. The specimen from which Dr. Liciitknstkin
made his description and figur(>, was obtiiined by F. DnnTE, Fisq., in the
vicinity of the city of INTexico, where the animal was indiscriminately
called Conifidrrja, Oroinilo and Omito. He was unable fo collect n?i\
inlbrmation in regard to its liabits. The specimen from which our de-
scription and figure were mad(\ was ca])tured by Mr. .Tohn K. Town-
send. We conversed with an American olUcer, who inlbrmed us that
he h.ad occasionally seen it near iMonterey in Mexico, that it there bore
no b(^tter character than its congener the Ermine in the more northern parts
of America; that it was destructive to poultry and eggs, and very com-
monly took up its residence in the outhouses on plantations, and under
such circumstances was regarded as a great nuisance. Fortunately lor
them, the species was considered as (]uite rare in the northern M^rifi
of Mexico, as the Mexican who pointed out this animal to our oflici r
stated, this was the first CoiiKKlnja he had seen in five years.
<;l'.0(iHM'HH.'AI, IM.srHUIl TION.
As we have not heard ot' llie existence of our Ermine in Mexico,
we are inclined to the belief that this species takes the place of the
BIIIDIJII) WKAWEL.
78
Eniimc ill Ukj Soulli, uiid that, willi similar roviiifj; and predacious
habits it lias a more i-xtnid.-d Kcogiaphioal rari^'e than is at present
known. The field of natnral history in Texas, Caliibini.i, and Mexico,
has l)..,-n as yet very iiuperlectly explored. We have (.niy heard of the
llridled W(N-iscl as l)einj,' fouiid in Cour widely separated localities— in
Texas bt^tweeii the Colorado and liio Grande, in iMexico in the vicini-
ty oC the capital, and in thi; northern parts near Monterey, and in the
valh^ys of the n)oui;tains south-west oC that city.
(JENERAL REMARKS.
In ooin|)arin« this sin^'ularly marked species with others from the
Kast(;rn and VVesteru hemispheres, we have been struck with thc^ uni-
formity existing on l)oth continents in the nearly equal distribution of
predacious animals, and in their close r(;semblance to each other, in
size, form and habits. The badjrer in Europe {Mdcs vulgaris) L in
Ameri(;a replaced by M. I.ahnnlnria. T\w. i-'.uropean Otter {Lulra vul-
gari.-;) has its representative in America in our Canada otter {Lulra
Canmlcnsis). The; European mink {P. lutreola) is replaced by our near-
ly similar (/'. vison). The Europeaji ferret {P. furo) by our western
l)laek-footed ferret {l\ nigrl/us). The ermine and common weasel of
(lie north of Europe (/'. aminca) and (/>. mlgaris) by our ermine and
brown weasel (/'. rrmhim) ami (P. fusca) in the Northern and Middle
States of America, and tli(. Jav-i ferret (P. nudipc.s) has its represent-
ative near the tropics m America in our {P. frcnnla), nearly of the
same size, and wilf. simil.-.r habits. There is evidently great wisdom
ill this arrang.Mnent of Providence. Countries under similar latitudes
producing larg.. n.mib,-rs of the smaller rodentia, require a certain num-
l)er of carnivorous animals to prevent their too rapid multiplication, which
m the ai.sence of such a provision of nature would be destructive of the
interests of the liusbandman.
'i '
ri!
VOi,. If.
-IC
74
GENUS PllOCYON.—SroRR.
DENTAL FORMULA.
Incisive-; Canine —; Motor — = 40
6 •— 1 6—6
Muzzlo, pointed and projecting beyond the lower jaw; ears, short .-uul
oval ; tail, l)iishy, and lony;. Feet, live toed, with Htronjr nails not retrac-
tile ; soles of I'eet, (posterior^ naked; the species rest on the heel, but
walk on the toes. Mammae, six ventral ; there is a gland on each side of
the anus which secretes a slightly olTensive fluid.
The generic name is derived Ironi (he Greek t^», before, and xvjit, a
dog.
Two species only have been noticed : one in the northern, and the other
in the southern parts of North America.
P R C) C Y O N L O T O R.— Linn.
Raccoon.
PLATE LXI.— Male and Young.
P. corpore supra canescente plus minus in nigrum vevgentc, infra, au-
riculis pedibusque alhicantihus ; facie albida, fascia sub oculari obliqua
nigra, cauda rufescente annulis 4-5 nigris.
CHARACTERS.
Body above, grayish mixed irith hiarh ; cars, and hcneafh, wki/ish ; a
hliirh patch across the eye. Tail with 4 or 5 annulations of black and gray.
SYNONVMES.
AuKCON, Smith's Voyages, xiii., p. 31.
Ukscs Lotoh, Linn., 12th ed., p. 7().
Er.xlrlKMi, Syst., p. l(ir)-4.
Schreber Siiugth,, p. 521, 3 t. 143.
Lk Raton, Bufl'on. vol. viii., p. ji. .'!;i7, t. xliii.
RACCOON. Y5
Raccoon Bear, Pennant's Arct. Zool., vol. i., p. 69.
PnocYON LoTOu, Cuv., Rrgne Animal, vol. i., p. U3.
" " Siibine, Jotinifil, p. G49.
" Hiirliin, p. 53.
" " Godman, vol. i., p. ,5.').
" " Dekay, New- York Fauna, p. 20.
PuocYON NiVEA, Gray, Magazine of Nat. Hist., vol. i., 18.37, p. r)80.
DESCRIPTION.
The body is rather stout, the legs of moderate length, and the appear-
ance of the animal would indicate that although he is not intended for
great speed, he is still by his compact and well org.anized structure, his
strong and muscular limbs and short and stout claw.s, capable of a tolera-
bly rapid race, and is able to climb, although not with the agility of the
scpiin-el, still with greater alacrity than his near relative the bear.
Head, rather round nose, tapering, sharp, and the snout moveable;
point oCihe nose, naked ; eyes, round, and of moderate size : moustaches,
H'W, very rigid, resembling bristles, extending to the chin ; ears, low, erect.
ellil)lical, with their tips much rounded, clothed with hair on both sides ;
on the inner surface the hairs are longer and less dense ; tail, of moderate
length and bushy. In its feet the Raccoon is partially plantigrade, hence
it was classed by Linn^mjs among the bears, under the genus (Irs us ; soles
of feet, naked. When it sits, it often brings the whole, hind sole to the
ground, resting in the manner of the bear. The canine teeth are large
-•ind extend beyond the lips. The nails are strong, hooked and sharp, not
covered with hair. The body is densely clothed with two kinds of hair ;
tlH! outer and longer, long and coarse ; the inner, .sorter and more like
wool.
COLOUR.
Point of nose, and soles of feet, black ; nails, dark brown ; moustaches,
nearly all white ; ear.^ lips, above the snout and chin, dingy white ; above
the eyes, and around the forehead, light gray. A dark brown patch ex-
tends from each side of tiie neck and passes the eyes, over the nose
colours of the hack ; eyes, black ; the longer liairs on the back are dark
brown at the roots, tliiMi yello^\■ish-white for half their length, iiiid are
broadly tijtped with black; the softer fur benealli, pale brown throughout
the wliole body; on tlu; sides and belly, the longer hairs are diiigv white
from the roots ; t lie tail has about six distinct black rings, and is tipped
with black; these rings alternate with five light yellowish-brown un-
nulations.
7e
RACCOON.
DIMENSIONS.
nid male, received from Dr. John Wright.
Nose to anterior canthus,
" " corner of mouth,
*' " root of ear,
" " " of tail.
Tail, (vertebra^), ....
" to end of hair, - - . ,
Length of head, - . . ,
Weight, 22 lbs.
lachoo.
2«)i
8
91
^
HABITS.
The Raccoon is a cunning animal, is easily tamed, and makes a plea-
sant monkey-like pet. It is quite dexterous in the use of its fore-feet, and
will amble after its master in the m;inner of a bear, and even lollow him
into the streets. It is fond of eggs, and devours them raw or cooked wiih
avidity, but prefers them raw of course, and if it finds a nest will feast on
them morninff, noon and night without being satiated. It will adroitiv
pick its keeper's pockets of anything it likes to eat, and is alw.tys on flif
watch for dainties. The habits of the muscles (iiiiios) that inhabit our
fresh water rivers are better known to tlii. Raccoon tlian to most cone ,oI-
ogists, and their flavour is as highly relished by this animal as is that of
the best bowl of clam soup by the epicure in that condiment.
Reing an expert climber, the Raccoon ascends trees with facility and
frequently invades tlie nest of th( woodpecker, although it may be secure
against ordinary thieves, by means of his fore-feet getting hold of the
eirgs or the younir birds. He watches too the sol't-shelled turtle when she
is about to deposit her eggs, for which purpose she leaves the wat(>r and
crawlinii- on to the white sand-bar, di-rs a hole and places them under-
neath the heated surface. Quickly does the rogue dig up the elastic ova
although ever so carefully covered, and appropriate them to his own use
notwithstanding the efforts of the luckless turtle to conceal them.
Sometimes, by the margin of a pond, shrouded, or crouched amonir tall
reeds and -rasses. Grimalkii.-iike. the Raceoon lies still as death, waitiu"
with patii nee for some ill-fated duck that may come within his reaeh.
No negro on a pJantalion knows witli more aeeiu-acy when the corn
(maize) is juicy and ready for the connoisseur in roastinsr ears, and he
does not require the aid of fire to improve (ts flavour, but attacks if mor,'
RACCOON.
77
voraciously (han the squirrel or the blackbird, and is the last to quit iho
cornfield.
The favourite resorts of tlio Raccoon are retired swampy lands well
covered with lofty trees, and throu-h which are small water-courses. In
such places its tracks may be seen lollowin- the margins of the bayous
and creeks, which it occasionally crosses in search ol' frogs and nuiscles
which are found on their banks. It also follows the margins of rivers for
the same purpose, and is dexterous in getting at the shell-fish, notwith-
standing the hardness of the siliceous covering witli wlncii nature has
provided them. In dry seasons, the re.!.;ding waters sometimes leave the
mn.scles exposed to the heat of the sun, which destroys their life and
causes their shells to open, leaving them accessible to the first animal or
bird that approaches.
In the drnary montlis of winter should you be encamped in any of the
great Western forests, obii-ed by the pifil.-ss storm to remuin for some
days, as we have been, you will not be un'haiikful if y,,., have a fat
Raccoon suspended on a tree above your camp, for whim kept awhile,
the Hesh of this species is both tender ami well-flavoured.
The Raccoon when lull grown and in good condition we consider auite
a handsome animal. We have often watched him with interest, can-
tiously moving from one trunk to another to escap," his view. His briirht
eye, however, almost invariably detect.'.l ns ere we could take aim at hiin.
and he adroitly fli-d into a hollow tree and escaped from us.
We once met with one of these animals whilst we were travelling on
horseback from Henderson to Vinceimes, on the edge of a large praii-ie in
a copse, and on approaching it ran up a small sapling from which we
shook it otr with ease ; but as soon as it reached the ground it opened its
mouth and made directly towards us, and looked so fierce, that drawing
a pistol from our holster.s, we shot it dead when it was only a few fee't
frotn us.
The young are at llieir birth quite small ; (about the size of a liahl
grown rat ;) some that we saw in Texas were not more; than two days
old and were kept in a barrel. They uttered a plaintive cry not uidikc
the wail of an infant.
The Raccoon usually produces from four !o six young at a time, wlii.di
are generally brought forth enrly in May, although the period of their
littering varies in dilferent latitudes.
When the Indian corn is ripening, the Raccoons invade the fields to
feast on the rich milky grain, as w.; have just stated, and a." the stalks are
too weak to bear th.; weight of these marauders, thev generally break
them down with their fore-paws, tear olf the husks from the ears, and
78
RACCOON.
witing season, the
ut various aniii lis
II the merry school-
iig 1(11" his iiidultfi ncfi
then munch them at their leisure. During
Raccoon is not the only trespas-ser on the corn i.
are attracted thither to receive their portion, iind
boy .shares the feast with f hem, at the riisk of p
by incurring the necessity of a physician's pi >cri|)tion th< next day. Th<
havoc committed in the Western States by.yqui.rel8 and other animals
is almost incalcidable, and no vigilance of the farmer can guard ;igain»t
the depredations of these hungry intruders, which extenu Iron rm to
farm, and even penetrate to tho.se embosomed in the foresis, vvheiu settle-
ments are few and far between.
The Raccoon is not strictly a nocturnal animal ; and although it gene-
rally visits the corn fields at night, sometimes feeds on the green corn
during the day ; we have seen it thus employed during the heat of sum-
mer, and it will occasionally enter a poultry house at mid-day, and
destroy many of the feathered inhabitants, contenting itself with the head
and blood of the fowls it kills.
The nest or lair of the Raccoon is usually made in the hollow of some
broken branch of a tree When tamed, these animals are seldom induced
to lie or sleep on a layer of straw.
There exists a species of oy.ster in the Southern States of inferior
quality which bears the name of Raccoon Oyster: it lies imbedded in
masses in the shallow waters of the rivers. These oysters are covered !)>■
high tides, but are exposed at low water. On these the Uaccoons are
fond of feedins, and we have on several occasions seen them on the oyster
banks. We have however never had an opportunity of ascertaining by
personal observalion the accuracy of a statement which we have fre-
quently heard made with great confidence, viz., that the Raccoon at low
tide in endeavouring to extricate these oysters from the shell, is occasion-
ally caught by the foot in consequence of the closing of the valve of the
shell fish, when numbers of these being clustered and indicdded together,
the Raccoon cannot drag them from their bed, and the returning tide
drowns him.
The naturalist has many difficulties to encounter when inquiring into
facts connected with his pursuit : every one acquainted with the habits
of even our common species must know, that the information gained
from most of those who reside near fheir localities, from their want of
particular observation, is generally very limited, and probably the most
mteresting knowledge gained by such queries, would be the result of a
comparison cf the accounts given at different places. From the Alle-
ghany mountains, thr vwamps of Louisiana, and (he marshes of Carolini^
RACCOON.
79
uad sly tricks thp i. co... procuring food.
We add the tbil.nviu,. no. „„ a Ruccoou kept ibr a considerable time
in a tame state or pa.iially domesticated.
Whoa it first came into our possession it was about one-third grown.
Bykmd treatment it soon beean.e very docih, but from its well known
mischievous propensities we always kept it chained
It was truly omnivorous : never relusing any thing eatable, vegetable
or anmial. cooked or uncooked, all was devoured with e,,ual avidiry Of
some art.cles however it seemed particularly (bad : as sugar, honey, chest-
nu s, ,,h and poultry. The ...nin.al would beco.ne almost frantic when
either of the two first was placed near it. but beyond its reach. No
means would be left untried to obtain the dainty n.orsel. It woul.l ru<h
orvvard as far as the chain permitted, and stretch out a fbre-j.aw toward
tlie object of ,ts wishes to its utmost extent, which failing to reach it the
other was extended ; again disappointed, the hind limbs were tried in sue
cession, by which there n-as a nearer approach to the food, on account
of tlie animal l)emg chained by the neck.
On being offered food when hungry, or roused up suddenly from any
cause, or when in active play, the eye was of a lustrous green, changino-
apparently the whole countenance.
It had a strong propensity to roll food and other things under its paws •
eegars in particular, especially when lighted. We have observed a simi-
lar propensity in young bears.
On placing a pail of water within its reach, it ran to it, and af>er drink-
ing would examine the contents to the bottom with the fore-paws s.-emin-
ly expecting to find some fish or frog. If any thing was Ibui'id it w.as
speedily brought to the surface and scrutinized. We have seen it throw
chips, bits of china and pebbles, &c., into the pail, and then fish them out
tor amusement, but never saw it put a particle of its fbod in to soak ex-
cept in a few instances when it threw in hard corn, but we do not think
It was for this purpose.
After pla. Mg fbr a short time in the water it would commonly urinate
in It and then upset the pail.
We gave it a fish weighing two pounds. The Raccoon turned it in all di-
rect.ons in search of a convenient point of attack. The mouth, nos^ fins
^ ent, &c., were tried. At length an opening was made at the vent, into whi..h
a paw was deeply inserted ; the intestines were withdrawn and eaten with
HVKlify. At the same time an attempt was made to insert the other paw into
'i».^ niout h of the fish to meet its fellow. This disposition to use the paws in
concert, was shown in ahnost every action, sometimes i
very
icrous
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80
RACCCXJN
i
m
manner. On giving the animal a jug, one paw would be inserted in the ajKT-
ture, and a hundred twists and turns would be made to join its fellow on
the outside.
After devouring as much of the fish as it wished, it placed the paws on
the remainder and lay down to doze, until hunger returned, watching tbp
favourit« food, and growling at any animal which happened to pass near it..
By degrees this propensil} to del'end its food passed oil" and it would al-
low the dog or fox to partake of it freely. We placed a half-grown fox
within its reach : the Raccoon instantly grasped it with its legs and paws
and commenced a close examination. It thrust its poMited nose in the ear
of the tbx to the very bottom, smelling and snuffing as if determined to
find out the nature of the animal. During this time it showed no dispo-
sition to injure the fox.
The Raccoon can scent an object for some distance .vith accuracy. We
suffered ours to go loose on one occasion, when it made directly for some
small marmots confined in a cage in another room.
Our pet Raccoon whose habits vv-e arc relating evinced a singular pro-
pensity to listen to things at a distance, ho\\^ever many persons were around
him, even though he might be at the moment eating a I'rog, of which food
he was very Ibnd. He would apparently hear some distant noise, then
raise his head and continue listening, seeming every moment more ab-
sorbed ; at last he would suddenly run and I;lde himself in his burrow.
This seems to be connected with some instinct of the animal in his wild
state, probably whilst sitting on a tree sunning himself, when he is in the
habit of listening to hear the approach of an enemy, and then hurrying to
his hole in the tree.
Enjoying the hospitality of a friend one night at his plantation, the con-
versation turned on the habits of animals : and m speaking of the Raccoon
he mentioned that it fed on birds and rabbits generally, but in winter
robbed the poultry houses. The negroes on his plantation he said kept
good dogs, and relied on them tor hunting the Raccoon.
VVhonever a Raccoon was about to attack the poultry house, the dogs
scenting him give a shrill cry, which is the signal for his owner to com-
mence the hunt. He comes out armed with an axe, with a companion or
two, resolved on a Raccoon hum. The dog soon gives chase with such
rapidity, that the Raccoon, hard pressed, takes to a tree. The dog, close
>\i his heels, changes his whining cry while running to a shrill short sharp
')iirk. If th(! tree is small or has limbs near the ground so that it can be
easily ascended, the eager hunters' climb up afier the " coon." lie per-
ceives his danger, endeavours (o avoid his pursuers by ascending to thefar-
'hcst topmost branch, or the extremity of a limb ; but all his elForts are in
v,un, his ri'lentless pursuers shake the limb until he is compelled toletgohi:>
RACCOON.
8]
hold, and he comes toppling heavily to the ground, and is instantly seized
by the dogs. It frequently happens however that the trees are tall and
destitute of lower branches so that they cannot be climbed without tlie risk
of life or limb. The negroes survey for a few moments in the bright moon-
light the tall and formidable tree that shelters the coon, grumble a little
at the beast for not having saved them trouble by mounting an easier tree,
and then the ringing of their axes resounds through the still woods,
awakening echoes of the solitude previously disturbed only by the hooting
of the owl, or the impatient barking of the dogs. In half an hour the tree,
is brought to the ground and with it the Raccoon, stunned by the fall : his
foes give him no time to define his position, and after a short and bloody
contest with the dogs, he is despatched, and the sable hunters remunerated,
—for his skin they will sell to the hatters in the nearest town, and his flesh
they will hang up in a tree to freeze and furnish them with many a savoury
meal.
The greatest number of Raccoons, however, are killed by log-traps set
with a figure of 4 trigger, and baited with a bird or squirrel, an ear of
corn, or a fish : either the appetite or curiosity of these animals will entice
them into a trap or entangle them m a snare.
Another mode of destroying this species is by fire-hunting, which requires
good shooting, as the animal only shows one eye from behind the branch of
a tree, which reflecting the light of the fire-hunter's torch, shines like .-i ball
of phosphorus, and is generally knocked out at twenty-five or thirty yards
by a good marksman.
The Raccoon, like the bear, hibernates for several months during winter in
the latitude of New- York, and only occasionally and in a warm day leaves
its retreat, which is found in the hollow of some large tree. We once how-
evei tracked in deep snow the footsteps of a pair of this species in the
northern parts of New- York, and obtained them by having the tree in which
they lay concealed cut down. They had made a circle in company of
about a mile, and then returned ♦:o their winter domicil.
The specimen from which the large figure on our plate was taken
was a remarkably fine male, and was sent to us alive by our friend, the
late Dr. John Wright of Troy, New- York.
GEOGRAPHICAL DISTRIBUTION.
The Raccoon has a very extensive geographical range. Captain Cook saw
skins at Nootka Sound which were supposed to be those of the Raccoon.
Dixon and Pari/fock obtained Raccoon skins from the natives of Cook'.s
River in latitude 00°. It is supposed by Richardson that this animal extends
IIACCOON.
farther north on the shores of th^ Pacific, than it does on the eastern side
of the Rocky Mountains. He farther states, that the Hudson's Bay Com-
pany procured about one hundred skini from the southern ])arts of the
fur districts as far north as Red River, latitude 50". We have not been
able to trace it on the Atlantic coast farther north than Newfoundland. It is
'bund in the Eastern, Northern and Middle States, and seems to become more
ibundant as we proceed southwardly. In some of the older States its num-
bers have greatly diminished, in consequence of the clearing of the forests,
and the incessant wars waged against it by the hunters. In South Carolina,
Georgia, Alabama, Mississippi and Louisiana, it is still found in great num-
bers, is regarded as a nuisance to the corn fields, and is at particular sea-
sons hunted at night by sportsmen and negroes. We have been informed
by our friend Daniel Morrison, Esq., of Madison Springs in Georgia, that
in his frequent visits to Arkansas between the Washita and Red Rivers,
the Raccoons are very plentiful and are frequently seen travelling about in
open day, and that many corn fields are nearly destroyed by the Raccoon
and the bear.
It was seen by Lewis and Clark at the rvi^h of the Columbia river.
We possess several specimens obtained in Texas, and were informed by a
friend, that although he had not seen it in California, he had heard of its
existence in the northern parts of that State.
GENERAL REMARKS.
As might be expected, an occasional variety is found in this species.
We possess a specimen nearly black ; another yellov/ish white, with the
annulations in the tail faint and indistinct. A nest of young was found
in Christ Church parish in South Carolina, two of which were of the
usual colour, the other tvvo were white ; one of them was sent to us ;
it was an albino, with red eyes, and all the hairs were perfectly white
with the exception of Riint traces of rings on the tail. We have no doubt
that a similar variety was described by Gray, under the name of Procyon
nivea.
We have accordingly added his name as a synonyme. Our friend Dr.
Samuel George Morton of Philadelphia kept one for some time alive
which was of a yellowish cream colour, and was also an albino.
83
GENUS ELAPHUS. — Grippitb
DENTAL FORMULA.
Incisive - : Canine
— ; Molar — = 34.
0-0 «-d
Horns, (existing only in the male,) round ; verj' large ; antlers termi-
natin^< in a fork or in snags from a common centre, suborbital sinus j
canine teeth in the male, in the upper jaw ; a muzzle.
The generic na ne in derived from the Greek £A«^#(, a Stag, or Elk ; the
name was applied by Pliny, Llvn^eus, and other naturalists, to designate
a particular species existing in Europe, Cervus Elaphus.
Three well-determined species may be arranged under this genus-
one existing in Europe, one in Walhihii, (the Nepaul Stag,) and one in
America.
American Elk. — Wapite Deer.
PLATE LXII._Male and Femaik.
E. Cervus Virginianus robustior cornibus amplissimis ramosis tere-
tibus, frontal ibus amplis ; cauda brevissima. Color rufescens, hieme fus
cescens, uropygio flavicante stria nigra circumscripto.
characters.
Larger than the Virginian deer. Horns, large, not palmated, with brow
antlers ; a naked space round the lachrymal opening. Tail, short. Colour
yellowish brown above, a black mark extending from the angh of the mouth
along the sides of the lower jaw. A broad pale yellowish spot on the buttocks.
84
ELK.
BYHONYMES.
Stag, Pennant, Arctic Zool., vol. i., p. 27.
Rkd Deer, Umfreville.
Do. do. Ray, Synops. Quad., p. 84.
C. SiitoNGyi.ofEFios, Schreber. Silugetiiiere, vol. ii., p. 1074, pi. 247, F. q. G.
Alces Ameuicanls, Jefl'erson's Notes on Virginia, p. 77.
The Elk, Lewis and Clark, vol. ii., p. 107.
C. Waptite, Ijarton, Med. and Phys. Journal, vol. i., p. 36.
Elk, Sniiili, Med. Reports, vol. ii., p. 157, fig. Male, Female, and Young.
Cervus (Elai'iius) Canadensis, (The Wapite,) Synopsis of the Species of Mam
nialia, Griffith's Cuvier, p. 776.
Do. do. Godman, vol. ii., p. 294, fig. Male.
Cervis Strongyloceros, Richardson, (The Wapite.) p. 251.
Elai'hus Canadensis, Dekay, New- York Fauna, p. 118, plate 28, fig. 2.
mn
DESCRIPTION
The Elk is of an elegant, stately and majestic form, and the wholo
animal is in admirable proportion. It bears so strong a resemblance to
the red deer of Europe, tliat it was for a long time regarded as a mere
variety of the same species. It is, however, much larger in size, and on
closer examination differs from it in many particulars.
Head, of moderate size ; muzzle, broad and long, rather small, not very
prominent ; ears, large ; legs, rather .stout, finely proportioned ; hoofs,
rather small.
From between the horns to the end of the frontal bone, beyond the nasal
opening sixteen inches, length of horns following the curvature of the main
branch four feet ; with all the roots three and a quarter inches, by two
and a quarter thick. There are six points on each horn, irregularly dis-
posed, varying in length from nine to sixteen inches, excepting one which
is two and a half inches only in length. At their points the horns curve
backward and upward, and are about three feet five inches :ipart, at about
half the distance from their roots to the extreme tip of the longest point or
main branch. The horns at the insertion are three and three-quarter inches
apart from the ring or crown at their roots.
In examining a number of elk horns we find a very remarkable variety
no two antlers being exactly alike on the same animal. We possess one
pair which has a blunt prong extending downward on the right side of the
face about nine inches, whilst the corresponding prong on the opposite side
ts turned upwards. The horns of this individual have five prongs on ona
ELK.
8^
horn and seven on the other. The horns are longitudinally channelled
most of the prongs inclining forward and upward, especially those nearest
the roots of the main horn. All the horns are large and round, with brow
antlers. The weight of the horns on full grown animals, as we have as-
certained by weighing about a dozen of large size, is from thirty to forty
five pounds.
The three hindermost teeth in the upper jaw are double ; the remainder
smgle. There are in the upper jaw of the male two very small canine
teeth inclining forward almost on a line with the jaw. There is a short
rudimentary mane on the fore-shoulder, and under the throat during the
winter there are long black hairs.
There is a space on the outer side of the hind legs covered by a tuft
which is of an irregular oval ^hape, of about one and a half inch in length]
the hairs which cover it being an inch long, lying flat and backwards, with
shorter hairs extending down the leg several inches below the space.
The hairs on the body generally are very coarse, rather short ; longest
on the back of the ham, where the whitish patch and the black line on the
latter unite.
The tail, which in summer is not bushy, is thinly clothed with hair run-
ning to a point. A young male has its horns which are in velvet, nearly
perpendicular, running but slightly backwards to the length of fburtcn
inches, where they divide into three .short prongs.
; il
J.i-i,.
Isifc ■
COLOUR.
Male.
Muzzle, nostrils, and hoofs, black ; head, dark brown ; neck, rather
darker, being nearly black; on each side of the tinder jaw there is a
longitudinal white patch, between which there is a large black stripe
extending along the lines of the under jaw, dividing about four inches
from the mout i, and continuing downward to the throat, where it unites
again and is diffused in the general black colour of the tliroat and neck,
leaving in its course a white space between the bone of the lower jaw]
nearly as large as a man's hand.
There is no light-coloured ring, or space, around the eyes as in the Euro-
pean red deer, but in the present species the space arout.d the socket of
Ihe eye is scarcely a shade lighter than the surrounding parts of the h-ad.
Under surface of the ear, yellowish white, with a hue of dark brown
on the margin; on the outer surface of the ear, there is a white patch
nhout four inches in length and nearly two inches wide, covering about
aih.rd of the ear, and running from near the root of the ear upwards at
the lower edge
■! ;!:
t m
8H
ELK
ii^i
In the younger males the hoad, (Jicc and hack of the neck are not near-
ly as d.irk as in spooimens of old animals ; the under jaw and throat how-
ever as well as as|).i(<»' above the nostrils are hlack as in flie lattir. The
upper and under snrfaees of hody and legs arc ii^lit brownish gray, I ho
legs being rather darker than tlie body.
On the rump there is u broad patch of light grayish white conuneneing
nine inches a'bovc^ the root of the tail, spreading downward on each side
to a point in the ham, ten inches below the tail. It is fourteen inches
across oi)posite the root of the tail, (from one ham to the other,) and
twenty-two inches in length from the back to the termination on the thigh
or ham below the tail. This grayish white patch is bordered on the thigha
by a strongly marked black space which also separates it all around, al-
though less conspicuously from the general colour of the body. We
have observed that in young specimens this jiale mark on the rump is less
conspicuous, and in one specimen is not even perceptible, and this peculi-
arity has most probably misled some of our authors in regard to the spe-
cii*s.
In specimens of about two years old the light but scarcely perce|)tible
markings on the rump gradually change to jvmyish brown between the hind
legs. In a still younger sjiecimen of a male about eighteen months old
which has the horns three inches in height, (which are comi)leteIy clothed
with sod brownish hairs to their summits,) there is scarcely any black on
the neck, and the white on the rump is not visible.
Female in summer colour.
We possess this animal in a state of conlinemont : slie has like all the
females of this species no horns. She bears a strong resemblance in form
and colour to the male. Her neck is rather thinner and longer, and her
legs and body more slender. Her eyes are mild, and she is in her dispo-
sition very gentle and docile. The hair in summer is like that of the
male, uniform in colour from the roots to the surface.
Winter colour.
Hoth males and females in winter assume a very heavy coat of dark
gray hair all over the body. These hairs are about two and a half inches
to three long and are moderately coarse and strong.
When examined separately they have a wavy or crimped appearance.
The white patch on the rump is strongly developed m contrast with
the dark iron-gray colour of the winter coat. At this season the male
has a i-emarkable growth of hairs on the throat as well as on the back
of the neck, which increase considerably in length, so that the latter
Tiight easily be mistaken for the rudiment of a mane.
ELK.
8Y
DiMENHIUNB.
Adult male (Ivilled on the Upper Missouri River).
From nose to root of tail,
Leiiylh of tail,
" ofoye, - . . .
From tip of nose to root of ear,
L(!njj;th of ear,
lloi^'lit to .shoulders,
iluiiip,
Girth l)ack of fore-legs.
Fast.
7
1
4
6
5
iDohci,
ll
8
y*
10
a
6*
I ho fomales we measured were rather smaller than the above : one
I^>1 <'d on the Yellow Stone Uiver measured seven feet six an.l a half
u.ch,.s from no.se to root of tail, and four feet seven inches from top of
shoulder to the ground.
HABITS.
On our plate we have represented a pair of Elks in the foreground of
aprMTie scene, with a group of small figm-os in the distance; it gives
but a famt u lea of this animal in its wild an.l glorious prairie home : Ob-
serve the splendid buck, as he walks lightly, proudly, and gracefully
along, t ,s the season of love : his head is raised above the willows bor-
denng the large sand-bar on the shores of the Missouri, his spreadin..
ant^lers have ac.,uired their full growth, the velvet has been rubbed off
and they are hard and polished. His large amber-coloured eyes arJ
bnghtened by the sun, his neck is arched, and every vein is cMstended.'
He looks aroMud and snufTs the morning air with dilated no.strils : anon
he stamps the earth with his fore-feet and utters a shrill erv somewhat
hke the noise made by the loon. When he discovers a group of females
he ra.ses h.s head, inclines it backward., and giving another trumpet-like
wln.tle, dashes off to meet them, making the willows and other small
trees yield and crack as he rushes by. He soon reaches the group, but proba-
bly finds as large and brave a buck as himself gallanting tV- \ir objects ot
h.s pursui^t, and now his eyes glow with rage and jealousy, his teeth are
(.ercely champed together making a loud harsh noise, his hair stands
.>rect and with the points of his immense horns lowered like the lance
of a doughty knight in times of yore, he leaps towards his rival and im^
88
J3LK.
m
it
4i
mediately a desperate battle endues. The furious combatants sway back
Wards and forwards, sideways or in circles, each struj^gling to get with
in the otlitr.s point, twisting their brawny ne-ks, and writiiing as they
endeavour to throw their opponent otf the ground. At length our valorous
Elk triumphs and gores the other, so (hat he is worsted in the Hght, and
turns ingloriously and flics, leaving the field and the females in posses-
sion of the victor : for should there bo any young Elks present during such
a combat, they generally run oif.
The victorious buck now ranges the tangled woods or leads the does
to the sand-bars or the willow-covered points along the broad stream.
After a certain period, hf)vvever, he leaves them to other bucks, and to-
wards the latter part of February his antlers drop off, his body is much
emaciated, and iie retires to some secluded spot, where he hopes no ene-
mies will discover him, as he is no longer vigorous and bold, and would
dread to encounter even a single wolf.
When we first settled (as it is termed) in ths State of Kentucky, some
of these animals were still to be met with ; but at present we believe none
are to be found within hundreds of miles of our then residence. During
a journey we made through the lower part of the State, armed as usual
with our double-barrelled gun, whilst passing through a heavy-timbered
',ract not far from Sinithland ;it the <th of the Cumberland River, we
espied two Elks, a male and female, which started out of a thicket not
more than forty or fifty yards from us. Our gun being loaded with balls,
we fired successfully and brought down the buck. The tavern keeper at
8mith!and went after the animal with a wagon and brought him into the
little village. The hunters in the neighbourhood said they had not seen
or heard of Elks in that part of the State for several years, although
some were to be found across ihe Ohio, in the state of Illinois.
At the time we are writing (1847) the Elk is not seen in any numbers
until you ascend the Missouri River lor a great distance. In that part of
the country, where the points in the river are well covered with wood
and under-brush, they are to be found at times in considerable numbers.
These animals however do not confine themselves to the neighbourhood of
the water-courses, but roam over the prairies in large herds. Unles?
disturbed or chased, they seldom leave a secluded retreat in a thickly
wooded dell, except to go to the river to drink, oi sun themselves on the
sand-bars. They are partial to the islands covered with willow, cotton
wood, Slc, and fringed with long grass, upon which they m.ake a bed
duritig the hot sultry hours of the day. They also form a bed occa-
sionally in the top of a fallen tree.
During hot weather, when mosquitoes abound in the woods, they rtv
ELK.
89
Mre to p,nd8 or proceed to the rivers and Immerse their bodies and
tt^:;rtr ^^'^ -'' " ^^"^ -- ^^-« ^"« -- - -.::
a ,^;^';\.";;7"^-"^.^»'*' Missouri river in the steamer Ome.a. we observed
bank I ''"'", one morning running along the shore under a high
mnk. It was covered with yellowish white spo.s. was as nimble and at
•ve as a latten. and soon reached a place where it could ascend the an
when .scampered off amid the tall grass. Wc had on board a servant oj
Mr CuRooN named A.kx.s LABOMOARnE who was a most expert hunter
W soon saw another fawn, and A,.ex.s went after it, the .oat having stop:
ped to wood. He climbed the bank and soon overtook the little anita'
b ha mg no rope or cord with him. was at a loss how to secure his cap.
mnn J . °'''''Y"«P^"''«''« -"^ with these a..d his pocket-handkerchief
managed to fasten the fawn around the neck, but on attempting tldrnj
. toward the boat the suspenders gave way and the fawn droppej 1 h!
stream, and s.am a few yards lower down, where it again lande one
oi our par y wUnessed from the steamboat the ineffectual efforts of lIbom
JOK and ran up to his assistance, but also without a rope or cord a„d
after much ado the animal again swam off and escaped
The food of the Elk consists generally of the grass found in the woods
he wddpea^vmes. the branches of willows, lichens, and the buds oi
wTth ; r TV^'' r"*" ^'^^ ^^^^P^ '"^^ «-- ^-- the ground
^alltees. "' ''' '^"'^^ '"^'^ ^"*^ ^^^'^ °^ ^^-bs and
.^ir\ '"vT^ ^""' ^^'""'^ "' '''''' P^^^^"*'^^ "^y Mr. PicoT wuh
a mo t splendully prepared skin of a superb male Elk. and a pair of horns.
The latter measured four feet six and a half inches in length; breadth
between the points twenty-seven and a half inches. The circumference
of the skull or base ten inches, the knob twelve inches, between the
knobs three mches. This animal, one of the largest ever seen by Mr
PicoT, was killed in the month of November, 1832.
IlEARNE says that the Elk is the most stupid of all the deer kind • but
our experience has led us widely to differ from that traveller as v^e
have always found these animals as wary and cunning as any of the
deer tnbe with which we are acquMnted. We strongly suspect Hearnb
had reference to another species, the American reindeer.
We chanced one day to land on a sand-bar covered with the broad
deep tracks of apparently some dozen Elks : all the hunters we had in our
boat prepared to join in the chase, and we among the rest, with our old
rusty double-iarreJled gun, sallied forth, and while passing through a
large patch of willows, came suddenly upon a very large buck ; the noble
t/OL II. — 12
rl JJI
I II
*
!
90
BLK.
animal wuh not more than a Hiw HtP|)H iroiii wlu-rc \\v sto(nl : our gun
wna lcv«'lle(i in an inctanf, ami \vc piillcil liiKK'"'', but the cap did not ex-
plode. The KIk was startled by the noise of the I'ltiiinK hammer, and
wheelih",' round, throwiny; up the h>ose soil with iiis hoofs, j,'al!ope(l olF
umoiiii th< sviUows towai'ds the river, mahiuK a clear path throu>;h
the small trees and jrrass. We ran to intercept him, but were too late,
and on reachinfi the bank the F,lk was already far out. in the stream,
8\vinuninK rapidly with its shoulders and part of it« back abov(! water.
On the oppoHile shore there was a narrow beach, and the moment the
Elk lou.'hed the bottom, it spranjj; forward and in a bound or two was
out of sif^ht behind the fri'i^inK mirtfin of trees o!i the shore. This, wo
are sorry to f.ay, \\,\a the only Elk we had an opportunity of lirini; at
whilst on o'.ir last western expedition.
The pair from which the ti>.'ure:' on our plate were taken we purcluised
at Philadelphia: they had been caujrht when young in the western partoi
Pennsylvania; the male was supjjosed to be four or five years old, and
the female also was full j;rown. These T'jlUs were transported from IMul-
adelphia to our place near New- York- and we had a capacious and hij^h
enclosure made for them. Ti;e mnl«; retained much of its savage habits
when at liberty, but the female was quite gentle. When she was first
put in the pen, where the buck Wijs already pacing round seeking for a
weak ])oint in tlie enclosure, he rushed towards her, and so terrified her
that she made violent exertions to escape, and ran at full spetul with her
head up and her nostrils distended, round and round, until we had the
Ifi.rge box in which she had been brought up from Philadelphia p'aced in
the enclosure, when she entered it as a pi, ice of refuge, and with her head
towards the opening stood on her deleuce, on which the male gave u]) the
pursuit, and this box was afterwards resorted to wlienever she wished to
be undisturbed.
We had some difiiculty in taking the bridle ofT from the head of the buck,
as he kicked and pranced fiu-iously whenever anyone approached for tliat
purpose, and we were forced to secure his head by ; leans of a lasso over
his horr.s, and drawing him by main force to a strong post, when one of
our men cut the leather with a knife.
While these two Elks were kept by us they were fed on green oats, hay,
Indian corn, and all such food as generally is given to the cow, excepting
nrnips. which they would not touch.
We found that the pair daily ate as much food as would have sufficed
for two horses. They often whistled (as the hunters call this remarka-
ble noise, which in calm weather can be heard nearly u mile) ; this shrill
sound ippears to be produced by an almost spasmodic effort, during which
ELK.
91
the animal turns its head .ipwards and then i)arltwar(I.s. While we worf
outlining? thn m.I,., w •■..„ .,!.s,tv.-.I ln,„ r« dilat., .!.,, iarhrymal spac...
or o|u.nin«s ...I joining the cyrs, s;. timt thry ^^■vu■ ahnoNf as wi,|,. as I„„^r
Wh«-n w,. ,lnnv near \w wonhl inclin.. his h.-a.i ,si(i,.\v!,vs, .•ml hack hi.
uppT lip. and show a poilion <.t his t..Mmi(. .md .'in.. wliU, which last h..
ground orfrrat.Mlu.jjHlH.r. lurni.u: his h„ad the while Cron, side to si.lo,
f r.d ey.'in^' us with a i<).>k .)(• an^'ry Huspicion. Ills eyes enlarRed and his'
v/hole fitfure part.xik (d'thc .x.-itciMciit he Iclt.
The process of ruhhin« otl' the velvet from the horns was soon ac-
ompl.she.l hy this animal ; he hc-an the moment he had h..cn taken
outof liishox, fo rub .-ifrainst the small d.ig-wood and other trees that
.sto..d within tl... en.-losnre. At a later period of the year we have
obs,.rv,.,l the Elk ruhhin- his antl.-rs against small trees, and actinj. as if
rn-aKcd in fiKht ; whether this mancruvr.. h-i performed for the p-npose
o! looMMun- th,- horns, town:ds the p,.rio.I wh.-n they annually drop off
we, in parliamentary Ian' . , are not i)ivpar. d \o say.
Elks at tiTies con-re,:;,,*, from th., numh.M- oflifty to sev.-ral luindn.ds
and in tl -se cases the whole herd follow the movements of their U-.uU-v
which is -..nerally th.- lar-cst and the strongest ma!.- of the party. They
all st<.p when he stops, and at tiuK-s th.'y will nil fnrn about with as nmch
ord.-r an.l with far greater c.-lority than a troop ol" horse, of which, when
thus seen in array, they forcibly remind us.
Fromacchlentor otherwis.. great diderences exist in the formation of
the antlers of the Elk, although the horns of all the American Ccrvii
are so specifically .listinct as to enable the cl.,se observer to tell al-
most at a glance to what species any shown to him belonged. The
ease with which these animals pass, encumber.<l with .heir pon.lerons
and wid.-spr.-ading antl.'rs, through th.- h.-avv-timber.-.l lands of the
West, is truly marv.-ilons ; and «e .-nn liMrdly 1 elp wondering tl.n, they
are not opener caught and ..ntangl,.d bv their h..rns. Inst;..,,-... q.ere
doubtless are of th,.ir perishing Imm getting fastea.u l>etween vines or
tluck growing trees, but such cases are rare.
The ma!.. Elk drops his h,n-ns in Fc n-uary or March. The one we
ha.1 .lropp,.d one on tl... ninth of March, an.l ns the o(her horn hcl.i on for
adayortwobnger, the animal in this situation hnd quite an awkward
appearance. After th,. horns fall, the head looks sore, and sometimes
f... placs Iro.n which they have been detached are tinged with blood
As soon as the hug,, antlers drop off, the Elks lose their fierce and pu-
nae.ous character, and the lemaie^ are n„ longer afraid of them ; whiL
on the other hand, the males show thera no farther attentions whatever
I
92
ELK.
The young, sometimes one, but usually two m number, are brought
forth in the latter end of May or June. It is stated by Godman, we
know not on what authority, that when twins are produced they are
generally male iird female.
A friend of ours related to us some time ago the following anecdote.
A gentleman in the interior of Pennsylvania who kept a pair of Elks in a
large woodland pasture, was in the habit of taking pieces of broad or a
few handluls of corn with him wlien he walked in the enclosure, to
feed these animals, calling them up for the amusement of his friends.
Having occasion to pass through his park one day, and not having provi-
ded himself with bread or corn for his pets, he was followed by the buck,
who expected his usual gratification : the gentleman, irritated by the per-
tinacity with which he was accompanied, turned round, and picking up
a small stick, hit the animal a smart blow, upon which, to his astonish-
ment and alarm, the buck, lowering his head, rushed at him and made a
furious pass with his horns : luckily the gentleman stumbled as he at-
tempted to fly, and iell over the prostrate trunk of a tree, near which lay
another log, and being able to throw his body between the two trunks,
the Elk was unable to injure him, although it butted at him repeatedly
and kept him prisoner for more than an hour. Not relishing this pro-
ceeding, the gentleman, as soon as he escaped, gave orders lo have the
unruly animal destroyed.
The teeth of the Elk are much prized by the Indians to ornament their
dresses ; a " queen's robe " presented to us is decorated with the teeth of
fifty-six Elks. This splendid garment, which is made of antelope skins,
was valued at no less than thirty horses !
The droppings of the Elk resemble those of other deer, but are much
:arger.
The Elk, like other deer, lie down during the middle of the day, and
feed principally at er-'ly morning, and late in the evening. They drink a
good deal of water.
This species can be easily domesticated, as we have observed it in
menageries and in parks both of Europe and America. The males, like
those of the Virginian deer, as they advance in age, by their pugna
cious habits are apt to become troublesome and dangerous. The Elk
lives to a great age, one having been kept in the possession of the elder
Peale of Philadelphia for thirteen years; we observed one in the Park
oi' a nobleman in Austria that had been received from America twenty
five years belbre.
ELFL
!);»
GEOGRAPHICAL DISTRrBUTION.
.lu^E k st.ll exists, .n s.nall and decreasi.., „u„,ho..s, .asr ,>C„. Mi o "
and these remnants probably „,• la.^e herds would un.lonbtediv i- ,o
^.where were they not restricted to their present wild n.ounta w ^^ ^
haully accessible range, by the extensive settlements on the wel lid
Mr Pka,,k of Philadelphia mentioned to us some .'ifieen vears a.., that
te only region in the Atlantic States where he oonid pn.ure sp.;im'^
o the E!k was the highest and most sterile mountains in ,he , orth e
of PennsylvanIJ^ w.c-e he had on several occasions gone ,o hunt ,1
Beach and \ au,;„an, two hunters in whoso statements eonli.len.-e e^uld
be placed that as late as 1826, Elks were seen and killed on th
>.-aneh o the Saranac. On a visit to Western A'irginia in 11
heard ol the existence of a small herd of Elk that had been kno v n '
many years to range along the high and sterile mountains a !
rndestothewestofthe Red Sulphur Springs. The herd was eo X
of eight males, whose number was ascertained bv .l,eir tracks i e
«now. One of these had been killed 1, a hun.er/and ,l,e num l w
reduced to seven. Our inibrmant, a friend in who„. ,he hi.hest eo ; "
could be placed, snpp„«ed, as all the individuals in ,|,e herd ha.l h..r ! e
race would soon disappear from the mountains. As, h,.w,.ver, the mal.'s -.t
certam seasons ke,.p in separate groups, we have n,. doubt there was •
.undar or larger enl of .Wnales in the same range ; but the ni;:.:ri:
doubtless a.mually lessening, and in all probability it will not be many
years before the Elk wHl be entirely extirpated, to beyond seve a hun
■Jred miles west of the Mississippi. "
WP^
Oi
ELK.
fo I ^r.t ' *"r "^ *' T^tc„.Rasn., does not extend its range farther
to the north than the 56th or 57th parallel of latitude, nor is if found
he sT^tT ' "l'"'^" ''"" ^'^ ^""'^ '^'"' «^ Lake Winnep.:: .
h Saskatchewan .n the 103d degree of longitude, and from thenc till it
strikes the Elk nver ,n ,he IHth degree. It is found on the western
prair.es, and ranges along the eastern sides of the mountains in Texas
and New Mexico It is also ibund in Oregon and California. Its mos
southern geographical range still remains undetermined.
GENERAI, REMARKS.
with the true deer (Ce..«.v,) to which they are very closely allied in their
character and habUs. As that ge^ms however has been greatly enlarged
m consequence of the discovery of new species, the deer have been conve
n.ently d.v,dedmto several sub-genera, of which our species is the lar-
gest and most interesting among the true Elks {Elophus)
The Amencan Elk, Wappite, or Stag, was for a long period consi.lered
Klent.cal with the European red deer, (C. Ehrphus,) and was, we believe
first treated as a distinct species by lUv. It was subsequently noticed by'
Jefferson and described and figured in the Medical Repository. The dill
lerence between these two species is so great that they may be distin
guished at a glance. Our Elk is fully a foot higher at the shoulders than
the European red stag. The common stag or red deer is of a uniform
blackish brown, whilst the Elk has all its upper parts and lower jaw yel-
lowish brown. It has also a black mark on the angle of the mout h which
IS wanting in the other. In the European pecies the circle around the
eye is white, in the American it is brown. There are other marks of dif-
ference which it is unnecessary to point out, as the species are now re-
garded by all naturalists as distinct.
Our esteemed friend Dr. R.ctahdsc^v has applied to this species the name
oi Cermts strongyloceros of Sohremer, because the figure of Perrault
(Mem. sur les an. vol. 2, p. 45) did not exhibit the pale mark on the rump
and he thought it not improbable that Perrault's figure was that of the
black-tailed deer {Ccrvus rnacrolis). We do not believe that the latter spe-
cies ever reaches the latitude where Perrault'h specimen was procured •
Elk exhibit only faint traces of this pale mark on the rump, and in some
they are entirely wanting. We have scarcely a doubi that Rav's de-
script.onwas intended to apply to our American Elk, and we have there-
'.I
w-
^
V
l^.A
nV
^,
V
l^.A
nV
r
m ■
,ji,.
U/'
LEPUS CALLOTIS.-WAOLKB.
Black Tailed Hare.
PLATE LXIII.-.MALB.
I., magnitudine, L. glaciafem adaequans, supra flavescente fusco
que varius, subtus albus; auribus pedibusque pr^longis, Cauda longa
nigra. ° '
cano
i 'I
CHARACTERS.
Size Of the polar hare ; ears and legs, very long ; tail, long and black;
mottled with gray and yellowish-brown above, beneath, while.
SYNONYMES.
Lkpu8 Caliotih, Wagler, 1832.
" ,g3^;'"'"^,^"''^^'^,^' B«7«- P'-o^^edi^g^ of the Zoological Society of London.
1 833, p. 4 1 , marked ,n tlie Catalogue of the Zoological Society, 582
plua, vol. vm., pt. 1, p. 84, an. 1839. ^nuaaei
DESCRIPTION.
This interesting species is similar to others composing a certain group
of hares found in America, characterized by being large, and havin- very
long ears, and long and slender legs and bodies, the whole form indicatinL'
capacity frr long leaps and rapid locomotion. In all these characteristics
Lepus Callotts approaches nearest to Townsexd's hare, {Lepus Town-
sendn,) which may be considered the type of this group.
COLOUR.
The whole of the upper surface, fawn colour, tipped with black ; hair^
on the back, silvery gray for one-third of their length, then pale fawn
then black, then fawn, tipped with black. Back of the neck, brownish
black, slightly tipped with lawn. A number of hairs of unusuai len-^th
(two and one-fourth inches,) and delicately interspersed along the sides
•n the greatest abundance along the shoulders. These hairs are black
from the base for two-thirds of their length, the remainder pale fawn •
96
BL\CK TAILED HARE
I III' -f
sides, and under parts of the neck, dingy pule fawn, gradually becoming
white on the chest ; haunches, lcf,'s and under surface white ; the hairs
on the rump annuiated with black, and near the root of the tail almost
entirely black; t'le wliole of the tail on the upper surface to the extrem
ity black ; on the under surface the hairs are black from the roots, slightly
tipped with grayish brown. Hairs on the under surface of the feet, in
some specimens red, in others a soiled yellowish-brown. Ears, posteriorly
for two-thirds of their breadth black at the roots, gradually blending into
fawn, and on the inner third the longitudinal line of demarcation beins?
very distinct; this fawn colour is mixed with black hairs, edged at the tip
with black, the remainder if the edge fawn ; the outer margin of the pos-
terior surface to its apex pure white. Inner surface of the ears nearly
naked, except at the outer edge, where they are clothed with short griz-
zled brown hairs. Whiskers white and black, the former predominating ;
chin and throat, white. The marginal line of demarcation between t.xe
colour of the back and that of the under surface, is somewhat abrupt
across the upper portion of the thighs, and very distinctly marked.
DIMENSIONS.
Length from point of nose to root oftsil,
Tail (vertebra?), - - - - .
" including fur, ....
From heel to longest nail, - - .
From eye to nose, - . - .
Ears posteriorly, ....
InehM.
20
H
4?
1|
4f
2i
HABITS.
(>ur account of this species is principally derived from the journals ot T.
W. Audubon, kept during his journey through pait of Texas, made for I he
Durpose of procuring the animals of that State, and obtaining some knowl-
edge of their habits for our present work, in 1845 and 1846, with an ex-
tract from which we now present our readers.
"One fine morning in January, 1845, at San Anionio de Bexar, as 1
mounted my faithful one-eyed chesnut horse, admiring his thin neck and
bony legs, his delicate head and flowing flaxen tail and mane, I was
saluted with a friendly good morning by Mr. Calaiian, then holding the
important office of mayor of the little village ; and on his ascertainiii^
that my purpose was to have a morning hunt on the prairies and through
BLACK TAILED HARE.
97
±c chapparal, which I did day after day, he agreed lo accompany me in
search of the animals I was anxiously trying to obtain, and in quest of
which I rode over miles of prairie with my bridle on the knobbed pum-
mel of my Texan saddle, the most comfortable saddle I have ever tried
(Semg a sort of half Spanish, half English build,) my horse with his neck
btretchod out and his head about on a level with his shoulders, walking
between four and five miles an hour, turning to the right or to the left
agreeably to the slightest movement of my body, so well was he trained
leavmg both hands and eyes free, so that I could search with the latter
every twig, tussock or thicket, and part the thick branches of the chap-
paral of musquit, prickly holly, and other shmbs, which I am inclined to
thnik quite equal to any East-Indian jungle in offering obstructions to the
progress of either horse or man.
Mr. Calahan having mounted, we set out, and after about an hour's
hard work, occupied in crossing one of the thickest covers near the
town, gamed ^he broad and nearly level prairie beyond, across which to
the famt outline of a distant spur, perhaps of the rocky chain of mountains
that m this latitude lie between the wp.ter courses flowing toward the Gulf
of Mexico, and the streams that empty into the Gulf of California : so far
away indeed seemed these faint blue peaks that it required but a little
stretch of the imagination to fancy the plains of California but just at
the other side. I was enchanted with the scene, scarcely knowing whether
the brilliant fore-ground of cacti and tropica] plants, the soft indefinite dis-
tance, or the clear summer blue sky, was most beautiful. My compan-
ion observing my enthusiasm, warmed into praises of his adopted country
he had, he >aid, fought hard for it, and exclaimed, it is a country worth
fighting for ; when my reply, of whatever nature it might nave been, was
prevented, and all ideas of blue mountains, vast rolling prairies, «fec., were
cut short by a jackass rabbit bounding from under our horses' feet ; he
was instantly followed by my worthy friend the mayofnt full speed on hi-
white pony, to my great annoyance, for otherwise he would have stoppel
in a hundred yards or so. Away they went, and as my friend's horse
was a running nag, he doubtless expected to overtake the Hare, which had
only gained about fifty yards start during our momentary surprise. The
Hare, as I quickly observed, did not make much shorter leaps than the
horse. I could see it at each bound appear like a jack-o'-lantern floating
with the breeze over a swamp, but in less time than I have t .ken to write
•his, they had ran a mile, ihe Hare doubled and was a hundred yards in
advance, but could not stop and look behind, for he had such a race
that he knew well no time was to be lost in gaining some bod
/OL n. — 13
1. !
iitnlli
;i
Ifr"^
1
r
i
08
of
BLACK TAILED HARE.
cactus or chappaial. Now on came both Hare and hunter, and
the race was oCfhe swiftest when anotlier double caused the rider tc
pull up with such force that his stirrup leather broke, and the space be-
tween tiie mayor and the object of his pursuit was widened to a quarter
of a mile, and the chase ended ; our friend dismounting to relit. We hud
not the good fortune to start another of these hares that day.
Some time afterwards while at Castroville, a little place of about a
dozen huts and one house, this Hare was procured by a party of Indians
and brought to J. W. Audubon, who writes : " I chanced to be visited by
some of th( Shawnee Indians who were in the neighbourhood on a hunt-
ing expedition. They were highly astonished and pleased with my draw-
ings, which I exhibited to them while trying to explain what animals ]
wajited. 1 made a hasty sketch of a hare with immensely long ears, at
which I pointed with an approving nod of the head, and then made anoth-
er sketch smaller and with shorter ears, at which lust I shook my head
and made wry faces ; the Indians laughed, and by their gutteral eugh, haugh,
li, gave me to understand that they comprehended me ; and in a day or
two, I had a beautiful specimen of the B|ack-tailed Hare brought to me
but with the head snot off" by a rifle ball. The Indians were quite dis-
appointed that it did not answer my purpose, and smoothed down the fur
on the body, which is the only part of the skin they generally preserve, and
what they thought I wanted.
The specimen I drew from was shot by Powel, one of Colonel Hays'
rangers, from whom I received many attentions and who acted most
kindly while with me on one of my excursions from San Antonio. This
Hare is so rare in those parts of Texas that I visited, t;»at I can say little
of its habits. It appears to be solitary, or nearly so, fond of high open
prairie with clumps of trees, or rather bushes and thickets about them,
trusting to its speed for safety and only taking cover from hawks and
eagles. Near San iVtruchio, as I was informed, this Hare is more abun-
dant than in this vicinity, and two or three of them can occasionally be
started in a morning's ride."
The specimen from which Mr. Bennett described and named this Hare
(Lepus nigricaudaUts, Bennett, Zoological Proceedings, 18.33, p. 4l), has a
iT!'.re definitely marked line of" white along the sides and legs than the one
I drew from ; but this species varies so much in its markings, tha '^oure
with the characters given is probably as like thv? majority as j
The line of white and black near the tip of the ears extende. .u-
dinally, is by many considered a good specific character, but it does not.
1 think, hold out in respect to this animal.
BLACK TAILED HARE.
lect.ons of Europe ; I ..aw only two. and di.l not hear of the existence of
any ,n the nu.eun. which I had not an opportunity of examininT
om'r ^'w ;""" ;"'^•'^'''^«°"^ — ' '-ve been «ent kJe by our
kt 1 r : "'"""" o^ -Xnowled^in, the receipt of a Hne
sk.nirom L eutenunt Ab.rt. who also favoured us with some skins of
quadrupeds from the vicinity of Santa Fe. which we shall ha""cls io" to
no.ce elsewhere, and for which we return him our best thanks
_ J^h. specxes ,s called the Jackass Rabbit in Texas, owing to the length of
OEOORAPHICAL DISTRIBUTION.
<loe. not, however, occur near the shores of the lower R^H Rl„..
tudc 30 , Iron, which parallel to the southward i, becomes more abundant
and may be sa,d to he the common Hare of Mexico. Whether it is founS
beyond the hmit, of North America we are nnablc t. say, butsnpp , n„,
™r::h° h T '"" -r ""■" ^""""-^ "'*«-"■ ' -°' »
ZT , ; * ""^ """""" P°"'°" »f *= Western hemisphere
and as already observed, do not contain more than the two .pecir^T^^
r toZ .roaSrt: ^"" '° "- '- --- -- -"-
GENBRAI, REMARKS.
There is a specimen in the Berlin Museum, labelled Lepus Callotis Wao
|..a d,sc„bed by him in 1832. This .specimer. corresponds in al IsJ^^^^^^
bcnbed by Bennett. Hence we are oblieed to idnnt w .
l.-iu«the priority as the first scientific dlwht'"" "*"'' '"'
100
PUTORIUS PUSILLUS.-Dekat.
The Small Weabbl.
PLATE LXIW.
mliul^^!'^'^ ^"^ "^"°'' ' ''"'' breviuscula. Supra rufo-fhsca.
CUARAOTBIU.
A third smaller than the Ermine; tail rather short; Colour, brcwn
above white beneath. '
SYNONYMES.
MusTEtA (PUTonius) Vulgaris, Bach, Fauna Bor. Am., vol. i., n 45
i". Vulgaris, Emmons, Mass. Report, 1840, p. 44 >!'«'•
MusTELA PusiLLA, Dekay, Nat. Hist. N. Y.', p. 34.
DEHCRIPTIOJf.
This is much the smallest of all our species of Weasel, if we are to jud^e
from two specimens tha, are in our possession, which appear to be full
grown. The tail ,s about one-fourth the length of the body, and is a lit-
tie longer than that of the common Weasel (M. Vulgaris) of Europe It
.s. however, a still sn^nller animal, and differs from it in several other
particulars: its ears a.e less broad., its feet smaller, the colour on the
back IS a shade darker, the white on the under surface extends much far-
ther along the sides, towards the back, and the dividing li„e between the
colours on the upper and lower surface is more distinct. The head is
man, neck slender, and the body vermiform. Whiskers the length of
the head, ears very small, toes and nails slender, covered with hairs.
COLOUR.
wil?' w""l'"'' '" """''""' '''"' '^'' '''''''' '^"^^ "°^ b«««-« -hite in
mn er We k.pt a small weasel alive throughout a winter in our boy
hood, but cannot now decide whether it was this species or another,
(P F«.c.«,,) which we will describe in our next volume. That specie
underwent no change in winter. It is more glossy ,han the ermine in
THE SMALL WEASEL. |^,
summer pelade an.I a shacio paLr in colour. U is li^ht yellowish hrow.
en he head, neck, ami the whole of , he upper HudUce ; this colour pre
va.l8 on the outer portions oCfhe lore-legs to near the (bet. the oute
face ol the hin.l-legs. the rump, and the whole of the tail, which is not
Upped v..th black as in the ermine. The white on the under surface com-
mencfs on the upper lips and extends alo„« the neck, inner surface ol
the lec-s, rises high up along the sides, including the outer and inner
surfaces of the feet. The moustaches are white and black, the former
colour predotninating.
t
! 'I
tion
DIMENSIONS.
Length from point of nose to root of tail.
Head and neck, . . . .
Tail (vertebra)), - • . .
" including fur, - . .
HABITS
InehM.
7
3
S
2i
From theforni and structure of this species, we might naturally pre-
sume that It possesses all the habits of the ermine. It feeds on insects,
eggs of birds, and mice, but from its diminutive size we are led to sun-
pose that It is not mischievous in the poultry house, and would scarcely
venture to attack a full-grown Norway rat.
GEOGRAPHIC.VL DISTRIBUTION.
The jpecimens from which our descriptions were made, were obcained
m the State of New-York, one at the Catskills, and the other at Long
Island. If ,t should prove to be the species we once had in captivity it
exists also in the northern part of New-York, where we captured it
Richardson asserts that it exists as far to the North as the Saskatchewan
river, and Captain Bayfield obtained specimens at Lake Superior.
GENERAL REMARKS.
Sir John Richardson states that this species, like the ermine, becomes
white m winter in the fur countries. We are .lisposed to believe that
this ,s not the case in the latitude of New- York. This fact, however
.s no evidence that the species in those widely separated localities
are different. The ermine in the northern part of Virginia seldom un-
dergoes a perfect change, and in Carolina remains brown throughout the
whole year. Sir John Richardson states (p. 4.5) that the specimens pre-
sented to the Zoological Society by Capt. Bavpield, agreed in ail respects
I i :
102
THE SMALL WEASEL.
with the common weasel of Europe. We, however, examined ilusc
specimens and compared them with the European weasel, and found nc
difficulty in discovering characters by which the species are separated.
We have an indistinct recollection that the prince of Musignano nanu;d
the specimen in the Zoological Society ; but as he did not, as far
iS we know, describe it, we have, according to our views on these subjects,
assigned to Dr. Dekay the credit of the specific name.
103
MUS H U M I L I S.-BAOHMAK.
Little Harvest Mouse.
PLATE LXV.-MALE3 ato Females.
M. corpore supra rutilo-cinereo, et quoad baccas et lineam in utrisque
Jatenbus ferrugineo ; subt,;s flavo-albente. M. musculus minor.
CHARACTERS,
Smaller than the house mouse ; colour, reddish-gray ahore ; cheeks and
line along the side, light ferruginous ,■ beneath, tohite with a yellowish tinge.
SYNONYMES.
\IusHUMius,Bach., Acad. Nat. Sciences, Oct. 5th, 1841.
DESCRIPTION.
Incisors, small and sbort ; head, much more rounded, nose, less pointed
and skull proportionably broader than the corresponding portions in the'
common house-mouse ; legs, rather short, and slender ; there are four
'oes on the Ibre-leet, with a minute and almost imperceptible nail in the
pince of a thumb ; on the hind-lbot there are five toes ; claws short weak
sharp, and slightly hooked ; nose, short and pointed ; the moustaches are'
composed of a few hairs, not rigid, of the length of the head ; the eyes
are smaller and less prominent than those of the white-footed mouse re
srmbling those of the common hou.se-mouse ; the ears are of mode'rate
size, broatl at base, erect, ovate, clothed on both surfaces and around the
niges with short adpres.ed hairs, extending a little beyond the fur •
palms naked ; upper surface of feet covered with hairs to the end of niils-
the tail IS round when the animal is in a living state, but after the speci'
.nrns are dne,!, beconu-s s,,uare ; it is thinly clothed with short hairs ; the
lur on the wholo body is slioil, glossy, and very fine.
104
UTTLIO HARVEST MOUSE.
COLOUR.
Teeth, yellow ; nails, white ; eyes, hliicli ; moustaches, mostly white
a. few near the nostrils hiaek ; n()S(>, (rheeivs, ears on both surlaees, imd a
line extending; I'roni the sides of tlie iieek nnniinj^ aioiiy; the siioulder and
separating- the eolonrs of the l)acli; and under surface, dark hull"; on the
back, the iiairs are plumbeous at the roots, tiien yellowish fawn colour;
n|>|)cr lips, chin, and throat, white; neck and under surface of body
DIMENSIONS.
I'^oni point of nose to root of tail-,
Tail. ....
IJi'ight of car, . . _
Iiichoa
HABITS.
By the casual obs(>rver, this diminutive little species, on beiiiR started
iVoiii its retreat in the ionfj ki'!»ns. or under some fence or pile of brushwood,
ini<,dit be mistaken for the yeunj? of the white-footed mouse (^fus leitcopits),
or that of the junipinL!: mouse {]rrri()iirx Amrrinnius). It however dillers
widely tVoin either, and bears but a general lesemblance to any of our
American species.
About twenty years ajro. whilst we were (uideavouring to make our-
selves iicciiiiiinted with the species of smaller rodentia existing in the
Southern States, we discovered this little Mouse in the grass fields and
along the fences of the plantations a few miles from Cliarleston. S. C.
We procured it in the way in which Held mice and other small ijuadru-
peds in all countries can be most easily obtained, by having what are
denoMiinalcd tignreof t traps, set along fences and ditches in the evening,
bailed with meat and seeds of various kinds. On tin; following morning
we usually were rewarded witli a number of several interesting s|)ecies.
We (in two occasions preserved this Afouse in a domestic stale, once for a
yeiir, during which time it produced tsvo broods of young: the (irsi
consisting of tour were born in May, the second of three in .Inly.
Tliey reai'c<l all their young. We fed them at lirst on pea or ground nuts,
(Hif/xi^nd (inir/iix,) eornmeal, (mai/e.) the latter they preferred boiled, but
al"i(M' iiavinir lenijitcd their appetites with the seeds of the I'igyptian 3Iil-
let, {I'l iiiiisiliiiii tip/i()i(lnuii.) we discovered that they relished it so well,
we allowed it linally to become their exclusive food. They refused meat on
UTTLE HARVRST MOUSE.
1 Of)
nil occasions. Thov woro von- cr,.»#i-. ,.11 j ..
' '" '""""• " '"■" ''""'■ "■"'■ "■■'l-.l a m.l, l.„. i„ . vL lL"|. 'r bT
::■ "T:ir:, ; ■■ '• r " :""" ""■" » p«-.'U": ;:■ „ ;
-'' • ... a ca... with a ,n ,1.- .fth.. whi...n,o,.l .aous.: ,h.v u'Zlut^
«.o sam. fomah, with ,hn male oCth. co,„,no„ .J,,,, ' -„!•," '
^;U.y c n.. ., n.h,in. wi.h ou- litH. pet. an., J!: I;! ;;:;:
Mas lo, n,l ,,oa,l m tho c,,«... bitt.-n and mutilated in various places
1 ns ,, „.s ,s a rare sp.ci.s ; urCT ,, search ol' twc-nfy years wo h«.
ohta.ncd only a .iozcn specimens from ,he fields. The nerwT. ch w
have..lte^r seen thnn their occupants, were placed Tt'^^ :;
the ,roun., amon. ,he Ion« .ras, composed of^ soft withered «ras s a
-. .t M, „,, „„,,^ „, ^,,.^ ^^^^,^.. .^^ ^___^|^^ brush-heaps and henel
the rails „l lences, similarly constructed
We doubt whether this species is of much injury to the fhnner It
consumes but Httle ...in. is more lond of resi.li,,, m-ar ... : ; ^
n^' soe.h< <>| wh.ch it s.,hsists.th..,. .....„„ ,h. ,„...„ ,,.,,. ^ ;^;;
observed 1.. ,ts ..est su.;.ll sto.-es of ...-ass se.'.ls .J, . . ,'''''''
in.i Ti , ' u.is a Iciiiah; ciintured on th..
1 XI. necembe,-, ,,nd containing four you... in its n.„..iv. 'e ,.
therefore thnt this snecie. liie .1. r i. • • "'""'• ^^'' presume
OEOr.RAPl.lCAr, IltSTRnitmON.
Wo have met with this species sparingly in South O:,rolina -.lo..-. the
-■•.Loard. and received i, lr.„u !),, M.„„,,„, .„■ Abbeville S C V
cured a specimen in ri.e..,.,,.,. (c • v ^i '"cmik , .X 0. We pi-o-
-■7'">- '■'■■ - '"„ « i" "•,,:■:: ;:;.', ''';';'•
north-east as the St-.f,. ,.c v \- 1 i'-kui .is (ar to the
'■'"^ '-w;:.,:,ti:;':;;,:x »"■—"''
VOL. II, It.
iii !!
m . f il
i M
l|l
106
UTTLE HARVEST MOUSE.
GENERAL KEMARKS.
We sent a minute description of this species to the Academy of Natural
Sciences in 1837, which was read by our friend Dr. Morton ; although
informed that it was published in the transactions of the Society, we have
not seen it in print. A second description was published in the transac-
tions of the same Society, October, 1841. We have not ascertained that
the species has been noticed by any other naturalist.
In examining the teeth of this species, we have found that the tuber-
culous summits on the molars were less distinct than in those which le-
gitimately belong to the genus Mus, and that there are angular ridges on
the enamel by which it approaches the genus Arvicola ; it is in fact an
intermediate species, but in the aggregate of its characteristics perhaps
approaches nearest to Mus, where we for the present have concluded to
leave it.
107
GENUS DIDELPHIS—LiNN^ofi.
DENTAL FORMULA.
Incisive '^., Canme^; Mo/ar ^^' or ^^ =48 or 50.
ro-fn^H '"'"f T'^ ''"'?''' '' "'"'"''' P''^"*^^' «•*••«' l'^'-g«' membraneous,
rounded, and almost naked ; tongue, acculeated ; internal toe of the hind
foot, opposable to the fingers, and destitute of a .ail, pendactylous; nails
4';?::!::^"^^ '^ '^'^^' '^°™ ^'^^ ""'-'' ^^^^ -- - ^-^'e. and
The interesting group of the Marsupi alia has recently been arranged
by Owe. mto five tribes and families, and sixteen gener'a ; these „eS
the Virgmxan Opossum being, however, the only species k„"wn in
America north of Mexico. Most of the other species'of this genls (Is
at present restricted,) inhabit tropical America. It is comp.«ed of fi V
species, some of which are still doubtful ^ '^'"
BIDELPHIS VIRGINIANA.-^HATv.
Virginian Opossum.
PLATE LXVI._Female, and Young Male seven month, old.
D. pilis laneis basi albis, apice fuscis; sericeis longis albis- iacie
rostro colloque pure albis; auriculis nigri. apice flaviLtibus •' cauS
corpore breviore basi pilosa tota albicante.
CHARACTERS.
whilM hair. "' *^'' "'«■'"' ""■'*
108
VIRGINIAN OPOSSUM.
8YNONYMES
Virginian Opossum, Pennant, Hist. Q.ia.l., vol. ii., p. 18, pi. (J3.
., " " " Arctic ZouU>gy, vol. i., p. 73.
^ARiouK DEs Illinois, Bull'., sup. 0.
Ofossiim Amkhicam's, D'A/ara, Quad, du I'aragtiuy.
DiUKLPlllS \lli(ilMANA, Sluiw's Zool., Vol. i., p. 73.
Mausuimall A.ME1UCANU.M, l>son, ill Phil. Trans., No. 23S> p 105
towpEit, hid., No. 290, j). l.-))!-).
Opos.sLM, tatesby's f'an)lina, p. 120, fig. e.
liurto.i's Facts, Ol.scvations and Conjectures relative to the j-on^
„ , '■"*'"" ^'* *''^' <^>l'"s«iini of N. Am., London, 180J> and 1813
- ossiiM, l.awson's Carolina, p. 120, (ig. c.
J). V'iiujinjanus, Harlan, Fauna, p. 1 fj).
(Todnian. vol. ii., p. 7^ fig,
ViRG. Opo.ssl'm, (jriflith, vol. iii., j). 24.
" " Dckay, Nat. Hist. N. Y., p. 3, fig. 2, pi. 15.
Opossum, Notes on the generation oftheVirginian Opossum. (Didelphis Virginiana )
J. Baehinan, D. i)., Transactions of the Acad, of Nat. Sciences. April
1818, p. 40. '
Letter from M. Michel, ?.r. D., on the same subject, Trans. Acad. Nat.
tecieuces, April, 1848, p. 40.
DESCRIPTION.
Body, stout and clumsy ; head, long and conical ; snout, pointed : the
nostrils at the extiviaity of the long muzzle open on the sides of a protru-
berant naked and glandulous surface. Ears, large, thin, and membra-
neous ; mouth, wide, and borders rounded ; jaws, weak ; eyes, placed high
on the foreliead, small, and without external lids, oblique ; moustaches, on
the sides of the lace, and a i'pw over the eye, strong and rigid. The
tongue is covered with rough papilUe. Nails, of moderate length, curved ;
inner toe on the posterior extremities destitute of a nail ami opposable to
the other toes, thus forming a kind of hand. Tail, (which may be con-
sidered a u.seful appendage to the legs in aiding the motions of the ani-
mal), prehensile and very strong, but capable of involution only on the
under side, long, round, and scaly, covered with a few coarse hairs for a
few inches from the base, tiie remainder with here and there a hair scat-
tered between. Soles of the hind feet, covered with large tubercles. The
foiimle is lurnished with a pouch containing thirteen mamma; arranged
in a circle, with one in the centre.
The fur is of two kinds, a .soft woolly hair beneath, covered by much
longer hairs, which are. howev.M-, not sufficiently dense to conocal the un.
der coat. The woolly hair is of considerable xcngth and fineness, especi-
ully ill winter.
VIRGINIAN Opossum.
109
COLOUR.
»-.'"r;;::^^:: :;^,;r::x"r r- "^" "'- »'"- '^
line or,la,.k brow,, u„dor the cha" 2 f ,, "''"""'''"■''-'I''"-'' « -I"" «
i«l> blaok • w^ 1,.,„ ' '" "'"" *»»'""="» are brown.
i.row„ ;,!:;,::;::' '="»"--''-' »- whe. .h=y „». ..d,*
i, : '"''°'"' ""■ '""«' '"""S 'l-i'o whit,, wilh a v„ry ,li,„„c, b|„ck
DIMENSIONS.
laobet.
15i
12
I5i^
A Well grown female :
From point of nose to root of tail,
Length of tail, ---!.'*'
Height of ear, . . , _
Orifice of the distended pouch in diameter, " ."
Teats measured immediately after the young had been
withdrawn, ....
Weight, 121bs.
Tail, --...".'"'" *^
Weight, 22 grains.
HABITS.
nature thif nw.I- V^ ^ '"'^ ""^"^ unheard-of objects in
r I— ^.. :ii, v'pOiaUm WHS
5, ii
ilO
VIRGINIAN OPOSSUM.
m m
regarded by Europeans when they first saw it. Scarcely any tiling was
known of the marsupial animals, as New Holland had not as yet opened
its unrivall.d stores of singulariti vs to astonish the world. Here was a
strange animal, with .< he.-d and ears of the pig, sometimes hanirir.fe- on
the limb of a tree, and occasionally swinging like the monkey ny cb? tail '
Around that prehensile appendage a dozen sharp-nosed, sicek-h.-ad-j
yoimg, had entwined their own tails, and were sitting on the mother's
back ! TIk •istonished traveller approaches this extraordinary compound
of an animal and touches it cautiously with a stick. Instantly it seems to
be struck with some mortal disease : its eyes close, it falls to the ground,
ceases to move, and appears to be dead ! He turns it on its back, and
perceives on its stomach a strange apparently artificial opening. He
puts his fingers mto the extraordinary pocket, and lo ! another brood of a
dozen or more; young, scarcely larger than a pea, are hanging in clusters on
the teats. In pulling the creature about, in great amazement, he suddenly
receives a gripe on the hand— the twinkling of the half-closed eye and the
breathii.ir of the creature, evince that it is not dead, and he adds a new
term to the vocabulary of his language, that of" playing possum."
Like the great majority of predacious animals, the Opossum is nocturnal
in its habits. It suits its nightly wanderings to the particular state of the
weather. On a bright starlight or moonlight night, in autumn or winter
when the weather is warm and the air calm, the Opossum may every
where be found in the Southern States, prowling around the outskirts of
the plantation, in old deserted rice fields, along water courses, and on the
edges of low grounds and swamps ; but if the night should prove windy or
very cold, th.! Ix-st nosed dog can scarcely strike a trail, and in such cases
the hunt for that night is soon abandoned.
The gait of the Opossum is slow, rather heavy, and awkward ; it is not a
trot like that of the Ibx, but an amble or pace, moving the two legs on one
side at a time. Its walk on the ground is plantigrade, resting the whole
heel on the earth. When pursued, it by no means stops at once and
feigns death, as has ollen been supposed, but goes forward at a rather
slow sp,>ed, it is true, but as fast as it is able, never, that we are aware
of. increasing it to a leap or canter, but striving to avoid its pursuers by
sneaking off to some thicket or briar patch ; when, however, it discovers
that the dog is in close pursuit, it fiies for safety to the nearest tree, usu-
ally a sai)ling. and unle>s m„i,.sto(l does not ascend'to the top, but ;-eeks
an easy resting plMn," in some crotch not twenty feet from the ground,
where it waits silently and immoveably. till th<. dog, finding that his
master will not .-ome to his aid. and becoming weary of barking -.a the
foot of the tree, leaves tlw Opossum to follow the bent of his incll.
VIRGINIAN OPOSSUM.
nations, and conclude his nijji.tly round in .search of foo,K AlthouH. .
sbw traveller, the Opo.ssu.n, ,.y keepin. pcrseverin.ly on n 7: i^
he greater part of the ni.ht. hunts over much ground, and has b n
known to make a circle of a mile or two in one ni,h,. l.s ran-.. W-
ever, appear to be restricted or extended accor.lin. to its necersit'ies. as
whenu has taken up i,s residence near a corn field, or a ciuu.p of ipc
isfied, and U early and slowly carries its fat and heavy body ,„ its ouiet
home, to spend the remainder of the night and the succeeding dav i le
enjoyment of a quiet rest and sleep. "
wans of a sluggish animal. It possesses strong powers of s no whlh
a.d at m Us search after food ; its mouth is eapadous, and its j a Jl?
sess.ng a greater number and variety of teeth than any othe 'ou;
animals, evdencmg its omnivorous habits; its fore-paws, althon! „o
to the mouth The construction of the hind-foot with its soft yllcHn.^
ubercles on the palms and its long nailless opposing thund,. enal^U
to use hese feet as hands, and the prehensile taif aids it in ho din" \;
the hmbs of trees whilst its body is swinging in the air; i„ thi mann
we have observed it gathering persimmons with its mouth and for. pa "
and devounng them whilst its head was downwards and its bodv su'^ '
';' hT:^: 2„r " ^" -'-'''- -'' '- ^^"^-'■- -^ -^'. '^- <'^n
We have observed in this species a habit which is not uncommon
among a few other species of quadrupeds, as we have seen it ZZZ
rh:utrr:;?b'"'^ ''°""'"" ''^- '-^-'-^ ^^^y^^^- ^^^^
.or hours m the sun, bemg apparently dozing, and seeming to enjoy this
posmon as a change. Its usual posture, however, when asleep i eithe
.ng a full length on the side, or sitting doubled up with its '^ TZ
Loo: '' "' "": '""^'''''''^ ^'°'"'^^^"' "^^^^•' — of the
The Opossum cannot be called a gregarious animal, j Au-in^ summer
a brood composing a large family may be found together bu^Z he
young are well grown, they usually separate, nn<l each in'dh ,1 h ft
tor bmself ; we have seldom found two together ia the same r tea t
autumn or wuiter. >t.iie,u,i in
Although not often «„ abroad in verycol.l weather in winter thi, ani
mal „ far Iron, falling inU, that state of torpi.li.v to whicl t „ Z '
jumpmg nnoe. and several other specie, of ,„„.,r„peds are sol ec T J
Southern .States, there .re not ,„a„y clear „i,hts of starlight „ n,„„„*
112
VIROINIAN OPOSSUM.
in which they may not be found roaming about ; and although in I heir fur
thest northern range they are seldom seen when the ground is covered with
snow, yet we recollect having come upon the frank of one in snow a foot
deep, in the month of March, in Pennsylvania ; we |)ursued it, and captured
the Opossum- in its retreat— a hollow tree. It may be remarked, that ani-
mals like the Opossum, raccoon, skunk, &c., that become very fat in autu.nn
require but little food to support them through the winter, particularly
when the weather is cold.
The Opossum, although nocturnal in its general habits, is not unfrequent-
ly, particularly in spring and summer, found moving about by day. We
have on several occasions met with it in the woods at mid-day, in places
where it was seldom molested.
Nature has wisely provided this species with teeth and organs indi-
cating its omnivtjrous character and its possessing an appetite for nearly
all kinds of food ; and in this particular it exhibits many of the pro-
pensities and tastes of the raccoon. It t-nters the corn fields (maize), crawls
up the stalks, and sometim^-s breaks them down in the manner of the rac-
coon, to feed on the young and tender grains ; it picks up chesnuts, acorns,
chinquapins and beach nuts, and munches them in the manner of the bear.
We have, on dissection, ascertained that it had devoured blackberries,
whortleberries, and wild cherries, and :ts resort to the persimmon tree is pro-
verbial. It is also insectivorous, ar.d is seen scratching up the leaves in
search of worms, and the larvae of insects, of which it is very fond. In
„arly spring it lays the vegetable kingdom under contribution for its
support, and we have observed it digging up the roots of the small atama-
masco lily, {Zepherinn atamasco,) and the young and tender shoots of the
China brier, {Smilax rotundifolia,) as they shoot out of the ground like as-
paragus. It is moreover decidedly carnivorous, eating young birds that
it may detect on the ground, sucking the eggs in all the partridge, towhee-
bunting and other nests, it can find in its persevering search. It destrovs
mice and other rodentia, and devours whole broods of young rabbits
scratching about the nest and scattering the hair and other materials of
which it was composed. We have observed it squatting in the grass and
brier thickets in Carolina, which are the common resort of the very abun-
dant cotton rat, (Sigmodon hispidum,) and from patches of skin and other
mutilated remains, we satisfied ourselves that the Opossum was one amoii"
many other species designed by Providence to keep in check the too rap-
id increase of these troublesome rats. We must admit that it sometimes
makes a sly visit to the poultry house, killing a few of the hens and
playing havoc among the eggs. The annoyances of the farmer, however,
from this mischievous prooensity, are not as great as those sustained from
VIRGINIAN OPOSSUM.
113
some of the other species, and cannot for a moment be compared with the
destruction caused by the weasel, the mink, or the skunk.
1 he domicile of the Opossun. in which it is concealed during the da>
and where U brm,s forth its youn,, which we have often examiae '
..un ,n vanous localities. This animal isatolerable di,,e, .^tho gh
usua ly un.ler the roots of trees or stump., when the .round is so ele-
.a ed as to secure it from rains and in.ndations. The hollow of a large
.Hllen tree, or an opening at the roots of a standing one. also serve L
a convement place for its nest. The material which w have u ually
».und e,>n.pc..„g this nest along the seaboard of Carolina is the , on'
.aoss(/,/W.. .W.V); although we have sometimes found i com
posed of a bushel or more of oak and other leaves
On firing into a squirrel's nest which was situated in the fork of a tree some
iorty feet Iron, the ground, we brought down an Opossum, which Le^i
dently expelled its egitimate occupant. The Florida rat is nown to I e
heaps o st.c s and leaves, and construct nests sometimes a yard in cia n
er and two feet high : these are usually placed on the ground, bu Z
requently .-n the entangled vines of the grape, smilax, and supple jaclf
Zr~.,,ns .W„W,,) i„ these nests an Opossum may occasionally b found
do mg as cozd. as if he had a better right than that of mere poLssion '
lun mg the Opossum is a very favourite amusement among domestics
and field labourers on o„r Southern plantations, of lads broke loose from
schoo, the hoiidav;. and even of gentlemen, who are sometL^mor"
fond of th.s sport than of the less profitable and more dangerous and Z
t.guu,g one o, hunting the gray fox by moonlight. Although w have
never part.c.pated in an Opossum hunt, yet we have observed that it Tf
ZlZ^l77T '" ''"^ ^^"^ ^""^ ^'"^^ '" ''^ '"^J-'^^' °^ •-nan-
ces make up the huntmg party, and we have on two or three occasions
been he ..lent and gratified observers of the preparations that were go'g
on tbeant.c,patxons mdulged in. and the excitement apparent around us.
On a bright autumnal .lay, when the abundant rice crop has yielded to
li'hlwh^T 'V"'"^^ '"'^^"^^ ^''^^^ ^''^^'^^-^ »"' -h-on or two
shght wh.te trosts have tinged the field, and woods with a yellowish hue
npened the persimmon, and caused the acorns, ehesnuts an'd chinque s'
(C.sna.ra jn.nvlJa) to rattle down from the trees and strewed them oter the
ground, we hear arrangements en.ered into for the hunt. The Opossums
aave been hvmg on the delicacies of the season, and are now in fine order
end some are fiumd excessively fat ; a double enjoyment is anticipated
Ihe^fian of eatchu,g and the pleasure of eating this excellent substitute fo,'
vol.. !i 15.
114 VIRGINIAN OPOSSUM.
" C.mp, men." says one, " be lively, let us finish our tasks by four o'clock,
a 1(1 after simdown we will have ;v 'possum hunt." " Done," says another,
" and if an old eoon conwv* in the way of my smart do- I'im-her, I \h>. bound
llir it, he will shi.kr d,. lif,, out of him." The labourers work with in-
.•rea.s.nl alacrity, their fares are brif?htened with anticipated .■nioym,.ni,
and ever un'^ Mon the old familiar son;,' of " 'Possum up thr ^'um tree ''
is hummed, whilst the black driver can scarcely restrain the ulmle wan-
from breaking: out into a h)ud chorus.
The parapheniiilia belon-injr to this hunt arc neither showy nor cxpen
sive. There are no horses caparisoned with elegant trappin-.^-ao costly
Kin.s imported to order-no pack of hounds answering to the echoinjr
horn ; two or th.re curs, half hound or terriers, each havin- his appropri-
I'te name, and each regarded by his owner as the best do;r o„ ih,. plantation,
are whistle.l up. They obey the call with alacrity, and ih.'ir looks and intel-
ligent actions frive evidence that they too ,-.re well aware of th,- pirasuie
that awaits them. One of these luunble rustic sportsu.en shouhh-rs an
ax(; and another a torch, and the whol,. armn-cm<>r,t f.-r th(> hunt is com-
plefed. The glarin- torch-light is soon m-en .lispcrsing the shadows
of the forest, and like a jack o'lantern, gleaming along the skirts of the
.liHtant meadows and copses. Here are no old .rails on which the cold-
nosed hound tries his nose for half an hour to ci*f ,-h the scent. The tongues
of the curs are by no means silent-cvcr an<l anon there is a sudden start
and an uproarious outbreak : "A rabbit in a hollow, wait, boys, till I twist
him out with a hickory." The rabbit is secured and tied with a strin-
arojindthe neck : another start, and the pack runs off for a quarter of a mil^,
at a rapid rate, then double around the cotton liclds and among t\w. ponds
in the pine lands-" Call off your worthless do^r, ji,„^ ,„^. pj^J,,,,, ,,,,^ j„^
much sense to bother after a fox." A loud scram and a whistle brings the
pack to a halt, and presently they come panting to the call of the Uack
huntsman. Aller some scolding and threatening, and resfioir ^ ,p,..i,-ter of
an hour to recover their breath and scent, they are one more hied for-
wards, yoon a (rusty old dog, by an occasional shrill yelp, gi ves evidence
that he has struck some trail in the swamp. The pack gradually make
out the scent on the edges of th.. pond, and marshes of the rice fields,
grown up with wi:..,vvs and myrtle bushes (.>////vW/ cvrifcni). \t iemjth the
mingled notes c-!" shrill and discordant tongues give evidence tlmt the
game is up. The race, though rapid, is a long one, through the deep swajnp,
crossing the muddy branch info the pine lands, where the dogs come to a
halt, unite in conclav<', and set up an incessant b.-irking ;it the loot of a
pine. "A coon, a coon ! din't I tell you," says Monday. " that iiPincher come
across a cocn, he would do he work ?" An additional piece of split light-
t I. (
I' ! r
VJIUJIMAN (ll'O.SSUM.
wock: is a,l.le.l t„ tl.o forch, and tho eo„„ is s,-.... .lo„l.l..,l up iu the 'Wnn of
a horn.., s „..sr i,. „.e vn-y ,o,. of ,1... I,.n.-I...v..,l pi„... (,>. ,,.W/.)
M I. 1 .■.!. 1... Klonous l.uttl. that .msu.-s, ,1... pn.v.ss of.h.clo.s, un.l
he cptur. o( tl.o con. (ollow as a „.at,n- uf l-ourse. See our arfiJlc «„
th. raeeoun, pp. 80, HI. where we have briefly .ieseribe.l sueh a scone
Another trail is soon struck, an.l the do^^s all open upon it ,o . rce ' in
nn u.s,ant they rush, pell mell, with a lou.I burst ofmin,He,l tonjrues. upon
some anunal aIon,r the ,..|,,e of an old field destitute of tree- h
proves to be an Opossum, detecte.l in its ni.^htlv prowlin,^ e.p,.di.
t.on At f.rst, it lei.nis death, an.I. rolling, i.self into a ball, lies still
0.1 the ,n-ound; but the do^s ,,re up to this -"possum pl,,vin,^" and sei.e
upon .t at onee. It now leels that they are in earn/.s,. and are not
to be decnved. It utters a low ,n-owl or two, shows no (i^ht, opens
WKle US larjre mouth, an.I, with lew stru.^i,les. surrenders i.self ,', its
iMle. 1 ut our hunters are not yet satisfied. eith.M- with the sport or the
"x-Mt : Ihey have larire fan.ilies and a host of friends on the plantation, the
«a.ne is ab.mdant. a,.d the labour in procuring' it not fatis,n,in.^ so tlu.v
once^ more hie on the .lo^s. The Opossum, by its slow j,ait ^nd heav'y
tread, leaves its foot-prints and scent behind it on the sof- ,nud and d,mn
crass. Another is soon starte.l, and hastens up the first smnil .^um o.k
or persunmon tree, within its reach ; it has clambered up to the hi'.rhest*
Innl), and sits erouehin- up with eyes closed to avoid the li-ht. "Off jacket
Jim. and shake him down ; show that you know more about 'possum than"
your Koo,l-for-nutten fox-doj;." As the Ic How ascends, the animal .■ontinues
"H.untu.jr hi.dier to j,^et beyond his reach; still he eonlim.es in pursuit
until the ailriuhted Opossum has reached the farthest twitron the extreme
branch.'s of the tree. Th,> ne-ro now commences shaking.' (he tall pliant
tree top ; while with its hin.l hands rendere.l convenient and (lexible l,v its
opi)osms thumb, and with its prehensile tail, the Opossum holds <,n with
ffreat tenacity. But it cannot lonp: resist the rapidly accumulating jerks
ami shocks: suddenly the feet slip from the smooth tinv limb, and it han-^s
suspended fi,r a few moments only by its t,.il. i,- ihc"menntime trvin-^^o
re-am its hold with its idn.l hands ; but another sudden jerk br.-",ks"lhe
tw.s, and down comes the poor animal, doubled up like a ball into
t.eopen,.d j.ws of ea-cr and relentless canine foes; the poor creature
drops, and yields to fate without a struffffle.
In this manner half a dozen or more Opossums arc som,.times captured
before m.dnight. The sul,sequent boasts about the superior noses speed
ind courage of the several dogs that compo.'*ed this small motley pack-
( •• 1
116
VIRGINIAN OPOSSUM.
nu
the fat feast that succeeded on the following cveninj^, prolonged beyond
the hour of midnight, the boisterous laugh and the merry song, we leavt
to be detailed by others, although we confess we have not been uninter
ested spectators of such scenes.
" Lot iKit nnibitioii mwk their iisufiil toil,
" Their homely joys and destiny ohscnre,
" Nor grnndeur lieiir with a (hsdiiinful smile,
" The siiiiplo pleiusures of the humhle jioor."
The habit of feigning death to deceive an enemy is common to several
species of (luadrupeds, and we on several occasions witnessed it in our com-
mon red fox (V. Fuivus). But it is more strikingly exhibited in the Opos-
sum than in any other animal with which we are actiuainted. When it
is shaken from a tree and falls among grass and shubbery, or when detect-
ed in such situations, it doubles itself into a heap and feigns death so
artfu'ly, that we have known some schoolboys carrying home for a quarter
of a mile an individual of this species, stating that when they first Haw it,
it was running on the ground, and they could not tell what had killed it.'
Wo would not, however, advise that the hand should on such occasions be
suffered to come too familitirly in contact with the mouth, lest the too
curious meddler should on a sudden be startled with an unexpected ami
unwelcome gripe.
This species has scarcely any note of recognition, and is remarkably
silent ; when molested, it utters a low growl ; at other times its voice re-
sembles the hissing of a cat. The Opossum displays no cunning in
avoiding traps set to capture it, entering almost any kind of trap, very
commonly being taken in a log traj) called a dead fall.
From its very prolific nature it can afford to have many enemies. In
addition to the incessant war waged against it by men and dogs, we have
ascertained that its chief enemy among rap.-icious birds is the Virginian
owl, (*V/vj,' Virginiana,) which ilying abroad at the same hour in which the
Opossum is on foot, pounces on it, and kills it with great ease. We htive
heard of an instance in which it was seen in the talons of the white-hetided
eagle, {HtilieUi<! Icucocrphalus,) and of two or three in which the great hen-
hawk (F. Borcnhs) was observed feeding upon it. W(> recollect no instancti
of its having been killed by the wild cat or the fox. The wolf, it is said,
seizes on every Opossum it can find, and we have heard of two instances
where half-grown animals of this species were found to have been
.,»val lowed by the rattlesnake.
Although the dog hunts it so eagerly, yet wc have never been able to
hscertain that it ever feeds upon its llesh ; indeed, we have witnessed the
VIRGINIAN OPOSSUM.
117
(loR passing hy the body of a frrsli killed Opos.sum, and goiii<,' ofTlialf n
mile fhrtht!!' to Trod on soiiu- oH'ciisive caiTasc.
TheOpossmn is easily (ioincsticatcd wlicii ciiptiircd yonii-^. \Vf liavo
in cndcavourinfj: to invrsti>,'at(! oncol'the very extraordinary characteristics
of this species, prcsiwved a considerahle ninnbcr in coulineiiieiit, and our
experiments were continued ihrough a succession of years, 'i'iieir nocturnal
habits were in a considerable degree relinquished, and they followed the
servants about the premises, becoming troublesome by their familiarity
and their mischievous habits. They associated familiarly with a dog on
the premisec., which seemed to regard them as necessary api^'udages
of the motley group that constituted the family of brutes in the yard.
They devoured all kinds of food : vegetable's, boiled rice, hominy, meat both
raw and boiled, and tlie scraps thrown from the kitchen ; giving the pre-
ference to those that contained any fatty substance.
On one occasion a brood of young with their mother mad(( their escape,
concealed themselves under a stable, and became partially wild ; thev
were, in the habit of coming out at night, and eating scraps of food, but we
never discovered that they committed any depredations 0:1 the poultry or
pigeons. They ap|)eared however to havt^ ell'eclually driven oil' the rats,
as (luring the whole time they were occupants of the stable, we did not
observe a single rat on the premis(!S. It was ascertaincid that they
were in the habit of clambering over fences and visiting th(! neighbouring
lots and gardens, and we occasionally found that we had repurchased one
of our own vagrant animals. 'J'hey usually, hoW(;ver, returned towards
daylight to their snug retreat, and we believe would have continued in
the neighbourhood and multi|)lied the species had they not in their nightly
prowlings been detected and destroyed by the niMglibouring dogs.
A most interesting part olthe history of this animal, which has led to the
adoption of many vulgar errors, remains to be considcreil, viz., the gene-
ration of the Opossum.
Our investigations on this subject were commenced in early life, and
resumed as time and op|)ortunity were allbnled, at irregular, and some-
times after long intervals, :ind were not satisfactorily concluded until with-
in a month of the period of our writing this article, (June, IH 1!)). The
process by which we were enabled to ol)laiii the facts and arrive at our
conclusions is detailed in an article published in tht; Transactions of the
Academy of Natural Sciences, April, IHIS, p. 10. Subscipient investiga-
tions have enabled us to verify some of these facts, to re mo re some obsen-
ritifis in which the subject was yet involved, and finally to be prepared to
giv: a correct and detailed history of a peculiarity in the natural history
of this quadruped, around which there has hitherto been thrown a cloud
af mv-terv and doubt.
118
VIRGINIAN OPOSSUM.
riH
Our early authors— Margrave, Pison, Valent[nk, Beverly, the Mao.
auis or CiiAyTEi.Lux, Pennant, and others. ooiitoiKlcd that "the pourh wiis
the matrix of tlif younj,' Opossum, and that the mainiiiir aro. wilh rc<r;ird
to the younjr, wliat stalks are to their IVuils." Di: 13i.ainvii,i,e and I)r
Barton speak of two sorts of gestation, one uterine and the other mam-
mary. Blumeniiacii calls the young when they are first seen on (he
mammfp, ahortions ; and Dr. Barton's views (we quote from Griffith)
are surprisingly inaccurate : " Tlie Didelphes," he says, " put fortli, not
foetuses but gelatinous bodies; they weigh at their first appearance gener-
ally about a grain, some a little more, and seven of them together weigh-
ed ten grains." In 1810, Geoffroy St. IIili.aire propounded to natunviisfs
the following question: "Are the pouched animals born attached to
the teats of the mother?" Gorman, in his American Natural History,
published in 1820, gave to the world a very interesting article on the
Opossum, full of information in respect to the habits, &c., comprising all
the knowledge that existed at that day in regard to this sp(^cies. lie was
obliged, however, to admit, vol. 2, p. 7, " the peculiarities of its sexual in-
tercourse, gestation, and parturition, are to this day involved in profound
oi)scurity. Volumes of facts and conjectures liave been written on the
subject, in which the proportion of conjecture to (act has been as a thou-
sand to one, and the ditliculties still remain to be surmounted." And De-
KAY, in the work on the Quadrupeds of the State of N. York, (Nat. Hist, ot
N.York, 1842, p. 4,) states : "The young are found in the external abdomi-
nal sac, firmly attached to the teat in the form of a small gelatinous body, not
weighing more than a grain. It was along time believed that there (>xiste(i a
direct passage from the uterus to the teat, but this has been disproved
by dissection. Another opinion is, that the embryo is excluded from the
uterus in the usual manner and placed by the mother to the teat ; and a
third, that the embryo is formed where it is first found. Whether this
transfer actually takes place, and if so, the physiological considerations
connected with it, still remain involved in great obscurity."
The approaches to truth in these investigations have been very grad-
ual, and the whole unusually slow. Cowper, Tyson, De Blainville, Home
and others, by their examinations and descriptions of the organs of the
MarsupialiiP. prepared the way for farther developments. A more judi-
cious examination and scientific description by Owen and others, of the
corresponding organs in the kangaroo, the largest of all the species com
posing these genera, and the discovery of the f(Btus in utero, enabled natu-
r.'ilists to conclude, that the similar structure in the Opossum would
indicate a corresjjonding result. No one, however, was entill(><l to speak
with positive certainty until th.e young were actually detected in the
VIRGINIAN OPOSSUM.
119-
uterus lior could an explanation oft!,,, peculiarity in the growth of the
(<Etus be made until it was examined in its original bed.
We have been so fortunate in five instances as to have procured spoci-
mens m winch the young were observed in this position, and therefore
feel prepare.1 to speak will, c-ertainty. We are not aware that the young
of the Virginian Opossum had been previously detected in the uterus
All our mvestigalions were made in South Carolina, where this is a
very abundant species. For some years we attempted to arrive at the object
of our research..s by preserving these animals in a state of cor.finement. But
they were subject to many accidents : they fre.iuently made their escape
trom their cages, and some of them became overburdened with fat and
proved sterile, so that we did not succeed in a single instance in obtain-
ing young from females in a state of confinement. From this cause the
naturabsts of Europe, and especially those of France, who were desi-
rous of makmg investigations i,i regard to our Opossum, have been so
long unsuccessful. Their usual complaint has been, "Your Opossums do
not breed m confinement." In this, Dr. U.kton and our young friend Dr
M.cnBL were more fortunate, but in both eases the young were produced
before they were enabled to .letect them in their previous existing posi-
tion. We varied our experiments by endeavouring to discern the precise
period when young were usually produced. We ascertained, bv havin- a
number of females procured with young in their pouches, that' about the
close ot the first week in March, a little earlier or later, according to the
age ot the individual, or warmth, or coldness, of the previous winter
was the time when in this latitude this event usually occurs. Here how'
ever, another difiiculty presented itself, which for several successive sea-
sons, thwarted us in our investigations. In the third week of February
1847, by o(l,.rmg premiums to the servants en several neighbouring plan-
tations we obtained in thre.> nights thirty-five Opossums, but of that
number there was not a single female. A week afterwards, however
when the young were contained in the pouch, we received more females
tlian males. From this circumstance we came to the conclusion that
during the short periml of gestation, the females, like those of some other
species of quadrupeds, particulariy the American black bear, conceal
themselves in th.-ir burrows and can seldom be found. We then changed
our instructions for c-.pturing them, by recommending that they should
be searched for in the day time, in hollow logs and trees and places where
they had been previously known to burrow. 15y this means we were en-
abled atdilFerent times to obtain a small nmnber in the state in which
we were desirous of examining them. We feel under great obligations
to several gentlemen of Carolina for aiding us in our investigation- U.
! M
120
VIIUJIMAN Ol'OSSUM.
§u
ll'I
|'i-<'<-miM- s|),>ci,n,<iis. .-specially onr n-lalivrCloiirl ITabkei.i., Mr. Joiinsoi^
mid .1a>ii;s h'lsiir.u. I.:s,|.. a ,.|„s.> ,.l)s,.f\ .>r and inl.dlij^cnl naturalist. The
Intlcr. !.y Lis p.-rsrv.Tin- rllorts, pursued lor sonic y.-ais at Jordan's
lAlills.on 111,, upprr walrr,-. of lli.- I'Misfo. olitaincd iwo iVnialfs in ?.Iav,
lNli>. in (li,< p;hMi.-Mlarslal..in win,.!, lu- knew we w.-re anxious to procinv
.'"MM. and l.rou-l.l ilinnloiis wiilionl having been proviou.sly uwaro thai
we liad piil)lishi'd (lie I'acls a year hrlbro.
'I"h.- Opossums w(- W(-rc .Mialilcd lo cxaininr were dissoctcd on the IKh,
1 Hh and ISih l'\l)ruar;;. IHIS, and on th.> l-Jlli and -J-Jd May, INM). Soum'
hvou'j:Ut us by >lr. I'ishkr ra.-h w,M-hrd ^ frrains. Those of ono, snit
iisl.yCol. llASKix.,.w.-ii;li,-d;?M:n,ins; and the youiiir of another which wo
"I'taincd l)y a, Ca'sarian oix-ralion, at a moment when all (h.- rest liad
l)t<Mi exeiiided, and (his individual alone remained, weij^hed I frn,ins.
We remarked, that this however was a little the largest, of six that
compos,..! (h<. funily, live of which were already in the pouch and attached
to tlu> teats. Tla> lary:..st on,> wei-hed HI and another .'H jr,.,.,ins.
Tlie weii^ht, then, of the yotmu: ()p,)ssum at the moment of hirth, is b, rweeii
.•{ and Uniiins. xaryin- a little in did'erimt specimens as is (ho casein
the younii' of all animals.
Th,- diMir.'e of life and animation in youny: Opossums ;it tlie mo-
iiK'iit of hirlli has l.een sreiitly underrat..d. Th.-y are neith.-r abortions,
as Hi.eMK.NnA.-ii repiTsent..d llw-ni. nor as Dr. Uauto.n has .l.-serihed them—
"nol f.eluses. bul iivlatinous l)odi.-s. W(-iirhinfr about a ^rnin more or less,
seven of them to-i-th.-r w.-i-hiny; 10 grains "-but little creatures that are
nearly as well develope.l at birth as the yuun- of the white-footed mouse
and s,.vcral other sp.-cies of rodenlia. They an- covered by an infeuum«.nt.
nourish,-(l by ih.Mnninina.. breathe lhroujihn.)strils,p,M-lorin"the<)perations of
nature, are eapabl,. of a projiressive movement at the moment of their birth,
and arc remarkably tenacious of lile. Tin- individual which was dissected
from the parent in th.- manner abov,- detaih'd, moved several inches on the
labh- by crawlin- and rollinir. and survived two hours ; the thermom.'ter in
the room wasj.l (he time standinj; .at (iti° Fahrenheit. Th.- period of;r,.sta.
tion is froju tift.M-n to sixl.M-n .lays. W.- recMv.-.l a liMiial,. Ih.m a s.-rvant
who infor.n.Ml us. that h.. had that m..rninir s.-.-n it in inte.vours,> wi(h
tlic male. \V,- (irst saw (he younj,' on (he mornini!; of (he 17(h day. Om-
iViend Dr. ^ru.ni.r.TON Minu:i„ .a jrendeman of hi-h schMitilic attamments.
•";'' ;'''"^ '"■"' '"'"-' " <>i^.'-,mI in iiivestijratin;; the charact..r8 an.l habits
ul (his species, in a coimmmi.Mtion mail,- (,> us. (Trans, of ihe Aca.l. Xat
Sci.Mi.vs. April. ISIS. p. I,;.) j.ssuivd us from his p,.rs..nal ol)s,.rva(i.m in
which h.' was careful to nole the hour of th.. .lav, the exact i)crio.l is
\m
ViUMNIAN OPOSSUM.
i2i
1 r, (liiys. As hv [.oss,.,ssf<l hotter .)p|,<,.t,imiti«;.s of deciding in regard to tlif
tun.", fh.. aninmls being in a statt, ofdomostication, we are rather more
disposed to yield to his ob.serva-ions than to our own; there is, however
only the .lid'crence ofa day bet-,veen lis.
The young, when lirHt horn, iue naked and Ih'sh-coioured ; the eye.s, to-
gether with the ears, are covered by a thin inl.-gument through whicii these
organs and the protuberances of tlie ears are di.stinef ly visibl.;. The mouth
iB closed, with the exception of a small orifice, sufficiently large to receive
(1... teat, which is s«, thin and attenuated that it .seems no larger than the
Ixxly of a pin. Length of body, 7-liiths of an inch; of tail, a-lothi
The, nails, which can be seen with the naked eye, are very distinct when
viewed with a microscope, and are of a dark brown colour, small and
int.<-h hook.ul. The nostrils are open ; the lungs filled with air, and
whiMi placi-d in water, th.; young float on the surface.
'I'he number of young usually found in the pouch appear to be less
'han those that are born. The highest number we have found in the pouch
was thirteen, the smallest six ; whereas the preserved uterus brought to us
by Mr. Vm,m, eont.iined fifteen. In all such cases, where a greater num-
hv.v of young are produced than there are teats, the last of the brood
must inevitably p.-rish, as those that are attached appear incapable of
relincpiishing their hold.
The manner in which the young at birth reach the pouch, and become
attached to the teats, has been the subject of much speculation and in-
•iniry. We had an opportunity of examining this process in part, without
how,-ver, having been aware at the time that it was going on. We
inteiKle.! to dissect a small female Opossum, which had been a few days
in our possession, but ascertained in the morning at seven o'clock on the
.lay .,ur examination was to have been mad.^ that she had three young
in her pouch ; supposing from her small size, that she would produce no
additional number, we concluded to spare her life. She wasonfined in a
box in our study ; when we occasionally looked at her, we found her ly
ing on one side, her shouhh-rs elevated, her body drawn up in the shape
of a ball; the poucli was .jccasionally distcmded with her paws— in this
position the parts reache.l the edge of the pouch ; she was busily em-
pl.iyd with her nose and mouth licking, as we thought, her pouch, but in
which we afterwards ascertained, were her young.
At six o'clock in the afternoon we w.-re indued to examine her again
in eonse.pn.i.ce of having observed that she had for several hours appear-
e.l very restless, when w.s .liscovcred that she had added four more to h.T
pr.-vi()us number, making her young family now to eonsistof seven. With no
inconsi.lerable labour and the exercise of much patience, we removed
vol,, JJ. lis. "^IIIUYCU
'
I \u
o
I -2 -2
VIIUilNlAN Ol'USSUM.
i
three of th(i yoiiMi; iVoin llu' teals, one of wliicli pciislicti iiiidcr I lie pro-
cess, we re|)liieeil tlie two liviiij^ ones in tlie poiieli ; ut nine o'elock ex-
amined lier Mf^ain and found hotli fh(\ joini;;: once more altaclicd. We
eaoK^ to the eoiiclusion, thai, slie sliovcd llicm into the pouch, and
Willi her nose or lontjuc moved lliem to ihc vicinily of llie leals,
wiiere by an instinet of niitiu'e, the leal wasch'awn itilo the sin.ill oiilice of
tlie moulh liy snelion. We ohserved suhseiiueiilly, liiiil a yoiiii;,^ one llial
had l)eeii exiracled I'roiu its parent a few moments helbre the lime wlien
if would have been born, and wliich had l)een rolled up in warm cotton,
was instinctively eii>i:a<j;ed in suckinii? at the lihres of the cotton, and had
succeeded in drawins; into its month a considerable leni,'th of thread. A
nearly similar process was observed by our friend Dr. Micrii;i.. lie
slahis : "'I'he female stood on her hind le!j;s, and the b(»dy beinj^ much
bent, the younjj; appeared and were licked into tlu^ j.ouch."
There is a great ditlicully in deciding the question, whether the motlie:
aids the yoimg in finding the teats, in conse(iuenee of iIk^ impossibility ol
tlie speclators being able to know what she is actually doing, whilst her
nose is in the pouch. We believe the; majority of naturalists who had an
opportunity of witnessing our ex|)criments.caine to the conclusion, that the
mother, after shoving them info the pouch, left them to tiieirown instinct,
and they became attached without her assistance. We tried anotlnM- ex-
periment that suggested itself fo us. Relieving that the mother woidd
not readily adopt the young of another, or all'ord them any assistance, we
removed six out often that composed her brood, returned two of her own
fothe pouch, together with three others fully double the si/e. th.'it had been
obtiiined from another female. She was soon observed doubled up with
her nos(! in the pouch, and continued so for an hour, when she was exam-
ined and one of her own small ones was Ibiiiid attnclied to the teat.
Seven hours afterwards she was examiin>(l .again, and both the small ones
were attached, but the three larger ones still remained crawling about
the pouch. On th<^ following morning, it was ascertained that tlu! mother
had adopted the strangers, as the v.diole family of dili'erent sizes were
deriving sustenance IVom her.
On another occasion, a female Opossum had been sent to us enught by
a dog and much wounded, in consecjuence of which she died a few days
afterwards, hut first producing seven young which to every appearance
had been still born, ^'ef they were in tne pouch, and it ai)|ieared to us
that the mother's uncontrollnble attachment fo her young, induced her
to place her o(lsprin>r in the pouch, even after they were deiid.
An interesting: iiiipiiry remains to be answered: Is the 0|)ossum a
placental or non-i)lacenfni animal '. Until we were favoured with a
recent opportiinily of carefully examining a uterus, containiiiir nine
VTRGINIAN OPOSSUM.
123
youn;^ o„ on,, side, an.l six ..n fl„. „tl.,.r, kin.lly Lrouj^ht to m l.y ou.
n.-n.l Jamkh Flsuhk, w.. u..,-,. u.kU.I.. Cully „, unswnr this qm-stion
<>".• .h.ss,.,.|,„ns ,„..! ,.x:n,nM.ti„„s wn-,, wit„..ss,.(l l,y Pn,|i.ss„rs M,vu.
ruiK, [|..,,|.:, Drs. ll„K,,nK.K Min.r,,., Pu.u'i.kh i.n.l ..tlnTs
Tho ()p„ssu,n is, as litr us w,. m-,- ul,N, ,o jn.lj^. Ir„m the s,M.ciM.n.s
CXHUUM...I, a non-pla.M.nUil animal, inasmuch as there coui.i not he do
tected.h,.sli:,.l„..st ,.,liH.sion hetween the exterior meml.rane ofthe fe-
tus and the inh-rnal surface of Ihc mother. Th,- meml.rnnrs consisted of
a Vitellme sac, (illcd with ramilieations of omphalo-mescntcrie vessels
there was a sli^'ht appearance of an un.hilical cord and umhilieal v^s'
•sels, eons.itut.n;,^ a tru,. allantois, l.ut no portions of ihe.n were attached to
the uterus. Tlier.^ was no appearance of a placenta.
The Krowd. of tne youn^r Opossum is suprisin^^jy p,,,,i,i. y;,, ^^j,,,^,,,
the lar«:es. youn:; on,- at a week old an.l foun.l it ha,l in,-reas,.,l (Von, .T*
fXr.uns to ;j,) jr,,,!,,.. l,,,,,.,), of h,.;,d an.l horly exclusive of (nil I ' inel,*
tM.I, - uu-h. Th,. youni, at this a^e were v.-ry (..naeious oflilc.' al on re'
n.ovM,jr,„,,,,h,.y n.nain,..! alive on the Moor .vilhou. .inv ..overin.Mhrou.'b
a e,,o| n.j,d.l, n. a roon, containinif no fir,-, an,l still ,.xhil.it,.d a sli-^.t
•"ot.on attwelve o'clock ,.n ih,. Il.llowinjr -lay. The teats of th,- mother aller
they,.nn;,H.a,l l.,-,-,, ^M-ntly drawn off n.ea.sured an inch in len«,h, havin-^
.>een much distended, and appeared to have h,-en drawn into the stomach of
the young. The pouch,.s of the younj,- Icmah-s were quite apparent ; thev
used then- prehensile tails, which could now l,e frequently seen entwin,-d
uroun.l (he necks of others. At twelve day.s old the eyes were still close.l
alewha.rs had ma.Ie their app,-arance on the moustache ; the orifice of
thv ears were beginning to be develop,-d, and the nails were quite visible
and sharp.
When the young are four weeks ol.I, they begin from time to time to
relax the.r hold on the teats, and may now be seen with their heads occa-
s.onally out of the pouch. A week later, ami they venture to steal occa
sionallylrom their snug retreat in the pouch, an,l are often .seen on the
mother's back .securing themselves by entwining their tails around hers
In th,s situation she moves from place to place in search of foo,l, carry-
ing her whole family along with her, to which .she is much attached an.l in
whose delenc. she exhibits a con- iderable degree of courage, growlin- at
any intruder, and ready to use her teeth with great .severity on man or
Hog. In travelling, it is amusing to sc-e this large familv moving about.
Some ol the young, n,-arly the size of rats, have their tails entwined around
the legs ot the mother, and some around her neek. thus they are dra--ed
along. They have a mild and imiocent look, and are sleek, and in-line
coid.tion. an,I this is the only age in v,-hieh the word pretty can be ap-
! 1!
5' f
I 4
S
& i
124
VIRGINIAN OPOSSUM.
ve 'hf T, '^' ^TT ;"' '^"' " "'"^"' ^" '^"•^ half of her previous
weght. The whole fam.Iy of yomigremaia with her about two months
and cont.nue m the vicinity till autumn. In the meantime, a second and'
often a th,rd brood is produced, and thus twoorn.ore broils of difiv".u
ages may be seen, soinctimes with the mother, and at other times not ihr
prlt'lr"'"' "f ^'^V^^^P^'- °f «"•• g'-ay rabbit, is one of the most
prohhc of our quadrupeds. We consider the early parts of the thrPP
months of March May and July, as the periods in LTcaro inl vh^
they successively brmg forth; it is even probable that they breed stU
more frequently, as we have observed the young during aU the sprt
and summer months. I„ ,he month of May, 1830, whilst searching! a
the n.st of the Florida rat. we were startled on finding our boot uncere
momously and rudely seized by ,.n animal which wc^ soon ascer led
was a female Opossum. She had in her pouch five very small ^1
whilst. seven others, about the size of full grown rats were'dZ d^:;
ing from under the rubbish. The females produce young at a year old
but' haTth "^ '^'' '° ""^ '^^"^ ^""^ ^' ^^^'•>- - 'h-^- - Mar
but have their young as soon as the middle ,.f the succeeding May
There IS, of course, in this as wrll as in other species, some degree of
irregularity in the time of their producing, as well as in the num'er of
the r young We have reason to believe, also, that this species is more
prolific in the southern than in the Middle States.
REOGRAPHICAL DISTRIBUTION.
The Hudson River may be regarded as the farthest eastern limit of the
the east of the Hudson, m the southern counties of New-York as well as
on Long-Island and the warmer parts of the Eastern States, as the living
animals ai-e constantly carried there, and we have little doubt that if it was
considered important it could be encouraged to multiply there It has
been stated to us that in New-Jersey, within five or ten miles of New- York
as many as ten or fourteen of these animals have within a few years past'
been taken in an autumn by means of traps, but that their number is gradu-
ally diminishing It is common in New-Jersey and Pennsylvania, becom-
mg more abundant as we proceed southwardly through North Carolina.
South Carolina, Georgia, Louisiana and Texas, to Mexico ; inhabiting
.n great numbers the inter-tropical regions. To the west we have traced
VIRG; MAN OPOSSITAi.
llio
il in all the south-western states. It exists in Indiana, Mississippi Mis-
sour., and Arkansas, and extends to the Pacific ; it is said to exist in Cali-
fornm. It is somewhat singular, that in every part oi' America, as ih- as
we have been able to observe. ,he geographical ran^e of the Opossum is
very nearly the same as that of the persinmn tree, of whose fruit it is so
tond. 1 h.s we rej^ard, however, as merely accidental, as this food is not
essentml to ,ts support. The Opossum .either ceases to multiply or to
thrive m seasons m which the persimon has failed.
GENERAL REMARKS.
In our plate, we gave Pennant as the originator of the scientific nan..
of this spec.es. We find, however, that he only calls it the Virginia
Opossum, with a reference to the Didelp/n,s mnrsupialis, L.nnehs. Gmemn
subsequently arranged it un^Ier DuMj.Iu,. nunsupMs. As Shaw, in
1800, as far as we have been able to ascertain, seems to have been the
firs who applied the Latin specific name, D. Virginiano, we have, in ac-
cordance with the rules laid down bj naturalists, given him the credit of
trie sprcinc name.
! fl
I Nl
If; i
126
GENUS CAMS— LiNNiEus.
DENTAL FORMULA.
Incisive-; Canine—-; Molat =4).
1 — 1 6— C
The three first in the upper jaw, and the four in the lower, trenchant
but small, and called also false molars. The preat carnivorous tooth ah, ve
bi-cuspid, with a small tubercle on the inner side, that bclo^v with the
posterior lobe altogether tubercular, and two tuberculous teeth behind each
of the great carnivorous teeth. Muzzle, elongate ; tongue, soft ; ears,
erect, (sometimes pendant in the domestic varieties.) Fore feet, pendacty-
lous • hmd feet, tetradactylous. Teats, both inguinal and vental.
CANIS LUPUS.— Likn.—(Var. Ater.)
Black American Wolf.
PLATE LXVn. Male.
C. niger, magnitudine, formaque C. lupi.
»; li
CHARACTERS.
Size and shape of the Common American Wolf; Cams, lupus occidenta.
lis ; colour black.
SYNONYMES.
Loup Noir de Canada, Buffon> vol. ix., p. 364-41.
Black Wolf, Long's Expd., vol. i., p, 05.
" Say, Frank). Jour., vol. i., p. 172. -
" Griffith, Anim. King., vol. 2., p. 348
" Godman, Nat. Hi.st., vol. i., p. 267.
Canis Lyacon, Harlan '.s Firana, p. 82.
Vak. E. Lupus atek, Black Amor. Wolf, R.ichardson, Fauna Borcali Amer.. p. 70.
BLACK AMIJIIICAN WOLF.
DESCRIPTION.
127
We regard this animal us amen, variety of the Common .AM>ricai.
Woll to be hereafter closeril,,.,!. un.l nvvd only h,-re observe, that all
Wlute VVolt. the Red Texan Wolf and Ihe IJIaek Wolf, aiv of the same form.
ullhou-1, in size the White Wolf is considerably the largest.
COLOUR.
Faee, loj^^s, point of tail and under jaw, black ; bodv, irrec.„|arly and
transversely barred with blackish brown and greyish ; sides of the neck,
greyish brown ; behind the shouhlers, under the belly and on the Ibrehead
givyish brown. Some sj.ecimens are darker than others— we have ex-
ammed several that were perfectly black on the whole surface of the body
niMENPIONS.
Length of head and body -
Do. of tail vertebrjB
Do. including fur
Height of ear
Fetl. Inchw.
- 3 2
11
- 1 1
3
HABITS.
Not an indi- "dual of the party saw a Black Wolf during our trip up the
Missouri, on the prairies near Fort Union, or along the shores of that por-
tion of the V,.llow Stone River that we visited. Mr. Sav speaks of its
being the most common variety on the banks of the Missouri, but. unfor-
tunafely, does not state precisely where.
Wolves of this colour were abundant near Henderson, Kentucky, when
we removed to that place, and we saw them frequently during our rambles
through the woods after birds.
We found a Black Wolf in one of our wild turkey pens, early one morn-
ing. He observed us, as we approached, but instead of making his escape,
scpiatted ciose down, like a dog which does not wish to be seen. We came'
up within a few yards of the pen. and shot him dead, through an opening
between the logs. This Wolf had killed sev<.ral fine turkeys, and was
in the act of devouring one, which was, doul)tless, ihe reason he did not
atlempt to make his escape when we approached him.
There is a strong feeling of hostility entertained by the settlers of the
I' i f
K I \ i
128
ni.ACX AMKUUAN WOLF.
wild poll ions of the coiiiilry, lowiinl tin- WoH", as Ium Nln'tiRlh, nKility, and
cunninir, (in wliicli liisl (|Maliliciilion, lie is scarcci)' iul'crior to liis relative,
tlie I'ox.) lend to render liini tlie most destnielive enemy of tlieir |ii;:s.
slieep, or yoiuiK enlves, wliieh ran^e in tlie Hiresl ; liierelore, in our eoim
try, he is not -e niereirnlly dealt with tlian in any otlier part ol' ihi
world. Traps and snares of varions sorts are .set lor caloliinK iiirii in those
dislriels in which lie still abounds. Heinj,' more (leet and perhaps lietler
winded than the lox, the Woil" is .seldom pursued with hounds or any
other do<;s in open chase, uidess Wounded. AIiIioukIi Wolves are hold
iiini sHvaj;«', lew instances occur in oin- temperate re^:ions ol'lheir making
an alt.ick on man ; and we have only had one such case conn' under
our own notice. 'I'wo youn^? ney;roes, who resided near the hanks ol'tlu!
Ohio, in the lower jjnrtorthe Stale of Kentucky, about thirty years af^o.
had sweethearts livinj,' on another plantation, four nules distant. After
the labours of the day were over, they frequently visited the fair ladies of
their choice, llie nearest way to whose dw Miu},' lay directly across a lar<ie
cane brake. As to the lover every moment is precious, they usually took
this route to save time. Winter had set in cold, dark and gloomy, and after
sunset scarcely ii glimpse of light or glyw of warmth were to he found
in that dreary swamp, except in the eyr-s and bosoms of the ardent youths
who traversed these gloomy .solitudes. One night, they set forth over a
thin crust of snow. Prudent, to a certain degree, the lovers carried their
ax(-s on their shoulders, and walked as briskly as the narrow path would
fillow. Some trunsient glimpses of light now and then met their eyes in
tlit> more open spaces i.clwet>n the trees, or when the heavy drifting clouds
p:irling at time- allowed a star to peej) forth on the desolate scene. Fear-
fully, a long and frightful howl burst upon them, and they were instantly
aware that it proceeded from a troop of Hungry and perhaps despente
wolves. They paust-d lor a moment and a dismal silence succeeded. All
was dark, save a lew feet of the snow-covered ground immediatel . in front
of them. They resumed their pace hastily, wilh their axes in their hands
prepared for an .attack. Suddenly, the foremost man was assailed by
several wolves which seized on him, and inflicted terrible wounds with
their fangs on his legs and arms, and as they were followed by many
others as ravenous as themselves, several sprung at the breast of his
companion, and dragged him to the ground. Hoth struggled manfully
airainsf their foes, but in a pliort linn- one of the negvoes had ceased to
move : and the (>ther. reduced in strength and perha])s despairing of aiding
his mifortunate comrade or even savimr his o\\n\ life, threw down his axe.
spning on to the branch of a tree, and speedily gaine<l a place of safety
i.r.\$$] the boughs, llerc i:c passed a miserable night, and liie next morn» Ul-ACK AMKltlCAN VVOI,*'. 1--J n« >l.. honc-s of ..is lri..„,l lay s..H,t..n..l .r..un,I .,„ th. snow, whi.-h was and M-. M lu,. u ulatf, tli« t(,rrihl,, calust r.,,,1,,.. A ..ut -. , .. .. . ,,., t,.is ..,,oi,m,.n(3,.. as w« wore truvdlin^' br,twn,m • t:;.;.;- ""7"-; -7'""-' "^"'* '"■•"-.'«'.' Ao... .us S.U. ol .„,|.H„H.) Ar,erpu.,i„,.u,.our. ...os an.l rnrn.shin^„ur.dr .'.„- .;- mto ,M.nv,.rsa,ion with „„.. w<.rt..y host, and wore invited by ' U. u ■Mt.h.. vvol jmsuh.d. h.. had constn.ot.<I .houthalfa mi!. V,,, .,, >us. (.lad or tlH, o,,po,.tuni,y. w. a.oo,n,.aniod hi.n across ., (i.. M »..-. sk.rts ot the adjoini,,, fo,...s,. where he had three pits withi. ,. -ew -;; •" y-d. oreaC. oth.. rhey were about ei,.., L deep, broad I "' >'"' "»'oM. H<. as to render it i.npossihl. H.r the u.ost active animal to e cape ,rom ti.e.n. The ,nouth of .-aeh pit was cov.re.i with a revd n^ |.l.-^.<or„. of bo..,hs and twi.s. interlaced to«..h.. and at ac Ld tc: ' •..•-| o. tnnber. . hioh served for an axle. On this li.ht sort o phu, Z w ..,. was huiane..,! by a heavy stick of wo<.l .H.t< .1 to the u,!dc Me' a hux.. p,cc<, o( ,,u;:-.d v,,„ison was (i,-d for bait ' f . Pi., we re.rned to the nous. .. .4::::L:Z Zr ^ ^ h. nt o v.s.,,„, his pits daily, in order to see that all was ri«ht Th ' wo yes ha.l bn-n very bad that season ; had oestroyed nearly a I'nh an ... ..Hied one of his eol.s. •' iUu." added be, " ,L Z^^^^^ "Hull, and .. I have any luck, you will see son.e fun in the uli ' - With th.,s expeetatton we retired to rest, an.l were up at day-li.ht. "I thik " sa.d our host, "that all is ri«ht; fbrlsee the dogs are anxious to , a^a, to the pits, ami althouj^h they are nothing but curs tb.ir „n« '^ keen t.r wolves." As he took up his .u^ a:dr;:^: ^^ :::f ^ ^ogs .,e,an to how land bark, and whisked around us as if f.^ or" Mil When we reached the first pit, we found the bait had been distu b d .' .1... platfonn was sotnewhat injured, but the animal was not i I p 'o„ ;•> .unu.g the second pit, we discovered three famous fel.ow If' lul m .. ^o black and one brio, ,., all of .^ood si/,. Tl, , ^ I-. e„,..h, wuh ch.. ea. e,.,. .!„„.„ wZlrhi., w;:;^;!:'^" (ear n>ore than anj^er. To our astonishm„n^ fi V '"'Ucati. u.r .„ .,„„,„„.„ With U,c wolvex, shouU y „„„e „.„ hiX,!' , " 4 ' >, 1 'li •? f ^A.' ii i;u) BLACK AMERICAN WOLF. and le.'iviiiR his rifie to our care. We were not a little .surprised at the cowardice of the wolves. The woolman stretched out their hind leys, in succession, and with a stroke of the ivnife cut the principal tendon above the joint, exliihitinj? as little fear, as if he had been marking lambs. As soon as he had thus disabled the wolves, he got out, but hud to return to the; house for a rope, which he had not thought of. lie returned quickly, and, whilst I secured the platform in a perpendicular position on its axis, he made a slip knot at one end of the rope, and thn^w it over the head of one of the wolves. We now hauled the terrified animal up ; and motionless with fright, half choked, and disabled in its hind legs, the farmer slipped the rope from its neck, and left it to the mercy of the dogs, who set u\ on it with great fury and worried it to death. The second was dealt with in the same manner ; but the third, which was probably oldest, showed some spirit the moment the dogs were set upon it, and scullled along on its forelegs, at a surprising rate, snapping all the while furiously at the dogs, several of which it bit severely ; and so well did the desjjerate animal defend itself, tli.-it the farmer, iipprchcnsivc of its killing some of his pack, ran u|) and knocked it on the head with his axe. This wolf was a female, and was blacker than the other dark-coloured one. Once, when we wen; travelling on foot not far from the southern boundary of Kentueky, we fell in with a Black Wolf, following a man with a ride on his shoulders. On speaking with him about this animal, he assured us that it was !is tame and as gentle as any dog, and that he had never met with a dog that could fr.-.Il a deer better. We were so much struck with this account and the noblti appearance of the wolt', that we offered him one hundred dollars for it; but the owner would not part with it for any price. Our plate Wiis drawn from a line specimen, although not so black a one as we have seen. We consider the Dusky Wolf and the Black Wolf as iden- tically the same. As we shall have occasion to refer to the characteristics of Wolves gener- ally agam, we shall not prolong this article ; the Black, as already stated, being, in fact, only a variety. In our account of the Conunon Gray Wolf of the North, and the While Wolf of the Prairies, which last is very common, we shall give farther and more specific details of their breeding and other matters. GEOCRAPniCAL DISTRinUTIOS All packs of American Wolves usually consist of various shades of colour and varieties, nearly black, have occasionally been found in every part of the United States. The varieties, with more oi' Ic^s of black, eontiinie to in- crease as we proceed fart her to the soutii.und in Florida the prevailing colour BLACK AMKRICAN WOLF. 131 of th wolves .s black. We have seen two or three skins procured in tclTTru ?? "k '''^""'" " ^^" ^"^'^""^ «^ ^h« Philosophical Socety ot Charleston, obtained at Goose Creek, a few years a^o, that is several shades darker than the specimen from which onr d.rwin. wa. made ; and u. a ^an>, of seventeen wolves, which existed in CUeton Di.s. tnct, S. C, a few years ago. (sixteen of whicli were killed by the hunters m ejghteen months), we were infonned that about one fif.h were Id and the others of every shade of colour-from black to dusky ,rey and ye r "'"^•. .^'^^ "^r '^*"' °' ^^'^ ^^"^^>^ - *•- -"'hern par f Missouri, Louisiana, and the northern parts of Texas. t. 182 SCIURUS CAPISTRATUS.-Bosc. Fox Squirrei-. PLATE LXVIII S. magnus. colorem variens ; naso auriculisque albis ; piUs crassis- Cauda corpore longiore. ' CHARACTERS. She, large; tail, longer than the body; hair, coarse; ears and nose white ; subject to great mriefy in colour. 8YN0NYMES. SciuRus Capistratus; Bosc, Ann. du Miis., vol. i., p. 281. " VuLPiNus? Linn. Ell. Gmel., 1788. " NioKii; Ciitesby. Hlack Squiruel; Bartram's Travels in North America. ticiuKLs Cai'isthatls; Desm. Mamninlogie, p. ;}82. Vakieoatls ; Desm. Manimalogie,. p. 303. Capistuatus; Cuv., Regne Animal, vol. i., p. 189. Fo.x SijimuEi., Lawson's Carolina, p. 124. SciiJKus Capistratus ; Harlan. SciURus VuLPiNus ; Godman. DESCRIPTION. This is the large.st and most interesting species of the eenus, found in the United States. Although it is subject to great varieties of colour occasioning no little confusion by the creation of several nominal species, yet it possesses several striking and uniform markings by wliich It may, through all its varieties, be distinguished at a glance from any other. •' The Fo.x Squirrel is furnisb.ed with the following teeth, viz :— r • • • ^ . 00 4-4 Incmve Cavme -; Molar —~ 20. ' 00 |_4 But although we have thus given to this species but four grinders in (he upper jaw. which peculiarity applies to nearly all (he .specimens that may is; <te t H: ■■»n frin. Himi \"M I'IhIc IA\I -.huNnar, »,|i<^l,jjj,^,j|)| 5 ^.V . //^^/^/(/ ti*PmiMtO«'krJl St. 1 -i 1 ) '■ 1 \ 1 i i FOX SQUIRREL. 138 be examined,— yet, in a very young animal, obtained on the 5th of April, in South Carolina, and which had apparently left the nest but a day or two, we observed a very minute, round, deciduous, anterior grinder on each side. These teeth, however, must be shed at a very early period ; as in two other specimens, obtained on the 20th of the same month, they were entirely wanting. The teeth of all our siquirrels present so great a simi- larity, that it will be found impossible to de.jignate the species from these alone, without referring to other peculiarities which the eye of the practi- cal naturalist may detect. In young animals of this species, the tubercu- lous crowns on the molars are prominent and acute ; these sharp points, however, are soon worn off, and the tubercles in the adult are round and blunt. The first molar in the upper jaw is the smallest, and is triangular in shape ; the second and third one a little larger and square ; and the posterior one, which is about the size of the third, is rounded on its poste- rior surface. The upper incisors, which are of a deep orange colour ante- riorly, are strong and compressed. d*^ep at their roots, flat on their sides ; in some specimens there is a groove anteriorly running longitudinally through the middle, presenting the appearance of a doable tooth ; in others, this tooth is wanting. In the lower ja;", the antrrior grinder is the smallest ; the rest increase in size to the last, which is the largest. Nose, obtuse; forehead, slightly arched; whiskers, a little longer than the head ; ears, rounded, covered with short hairs on both surfaces ; there is scarcely any projection of fur beyond the outer surface, as is the case in nearly all the other species ; the hair is very coarse, appearing in some specimens geniculate ; tail, broad and distichous ; legs and feet, stout ; and the whole body has more the appearance of strength than of agility. COLOUR. In the ."^rey variety of this species, which is — as far as we have ob- served — the most common, the nose, extending to within four or five lines of the ey«?s, the ears, feet, and belly, are white ; forehead and cheeks, brownish black ; the hairs on the back are dark plumbeous n^ar the loots, then a broad line of cinereous, then black, and broadly tipped with white, with an occasional black hair interspersed, especially on the neck and fore shoulder, giving the animal a light grey appearance ; the hairs of the tail are, for three-fourths of their length, white from the roots, then a ring of black, with the tips white. This is the variety given by Bosc and other authors as Sciiinis aqnstratus. .Second variety : the Black Fox Squirrel. Nose and ears, white ; a few light-coloured hairs on the feet ; the rest of the body and tail, black ; there 131 FOX SQUIRREL. are, occasionally, a few white hairs in the tail. This is the original Black Squirrel of Catesby and Barpram, (Set. Niger.) Third variety. Nose, mouth, under Jaw and ears, white ; head, thighs and belly, black ; back and fail, dark <rrey. This is the variety alluded to by Desmarest, (Ency. Method, Maininalogie, 333.) There is a fourth variety, which is very common in Alabama, and also occasionally seen in the upper districts of South Carolina and Georjria. which has on several occasions been sent to us as a distinct species. The ears and nose, as in all the other varieties, are white. This, indeed, is a permanent mark, running through all the varieties, by which this species may be easily distinguished. Head and neck, black ; back, a rusty black- ish brown ; neck, thighs, and belly, bright rusty colour ; tail, annulated with black and red. This is the variety erroneously considered by the author of the notes on McMurtrie's " Translation of Cuvier," (see vol. i., Appendix, p. 433,) as Sciurus rufiventer. The three first noted above are common in the lower and middle dis- tricts of South Carolina ; and, although they are known to breed together, yet it is very rare to find any specimens indicating an intermediate variety.' Where the parents are both black, the young are invariably of the same colour— the same may be said of the other varieties; where, on the other hand, there is one parent of each colour, an almost equal number are of the colour of the male, the other of the female. On three occasions, we had an opportunity of examining the young produced by progenitors of both colours. The first nest contained two black and two grey ; and the third, three black and two grey. The colour of the young did not, in a majority of instances, correspond with that of the parent of the same sex : although the male parent was black, the young males were frequentiv grey, and vice versa. DIMENSIONS. Length of head and body - " tail vertebrae *' tail to tip - " palm and middle fore claw " sole and middle hind claw " fur on the back - Height of ear, posteriorly 14 5 12 4 15 2 1 d 2 11 8 7 HABITS. Although there isagenerrl similarity of habit in all the species of Sciurus, yet the present has some peculiarities which we have never ft)X SQUIRREL. noticed i„ any other. The Fox Squirrel, instead of preferrin. rich low lands. ,h.ckiy clothed with timber, as is the case with the Ca^oi • G.^^ rul^ch, ^^he,e the trees are not crowded near each other, and where ti^ere « an occasional oak and hickory interspersed. It is also fec,ue„t ^".^1 n .he v^cnuty o. nch valleys, to which it resorts for nuts, acor s and c Zl Vl>^ic.sua.apu„^^^^^ .hich such soils produce. In' some a J . : .' o llo t:r •" ' ?'f •"'^"' '"''' ^ '^'^' ^^^-^* '•- •'-"• -d mate a hollow tree of any kmd is sufficient lor its purpose if Nature has prepared a hole, a . occupied, if otherwise, the animal finds no difiicu.ty ingZ .nj,^ one or several, for its accommodation. The tree selected is in n ^jMUfiA .sponsu) too, IS irequent V a comnefitor fnt- fk„ .ts rsgs or young i„ such silualinns ■» scl.lom oiecte,] -r, "^ '"" f«™.;.,e ,„.„„.„„, „„, ,„ cha.„,a„.n,ea;;^: h j,:":.r„t:;; N,„„.,Tl ,hai may approach .heir „e«, nor ar, they id,c ,v h "l bTk ".1 .o„.nc, b„. co„,inuc hi.in,, his,,.,,. „„„ clapping , hoi ;„':„ 'l"'",lr„dcr,.,<,xpcllc,l. On ,he other han.l, when ,he Souirre]! youa, in ,he hoic of a .ree, and i. in.rn.ie. „ „ oi.hor 4^- , ^ L°r f „ro,:r ^r;:. "-" --■•■■*:-«--" :i: .;.;. an. vi.o„r ■:x.::::j^-!z: :Z rr ::r m.ler on the p„,«.„ion, of o.her,, as if conscious „f ,he iujSe „f i" ae s, cv,nce» a .Icgree of pusillanimity and cowardice 111 the vi(-ni!ty of the permanent residence of the P,.v «„ • 1 r"=r:''::t'=r:-a~^^ '"-««..„diu.onthe„the.„;.n::rsr.;r:;r::z::* IIINB!:^ 130 FOX .scillliUEL that scnrcely bears any rosemhlaiicc, to the l)arkiii<; which they utter or other occasions. The young are produced from the beginning of Mnrcfi, and soMictinies earlier, to April. The nests containing I lien), whicti we have had iipj)orlunlties of examining, \V(M'e always in liollow trees. They receive the nonrislmient of the mother for four or live weeks, when they are leil to shift lor tliemseh'es, but continue to reside in t..e vicinity of, and even to ->ccupy the same wests with, their parents till autumn. It has been asserted .)_, several planters of Carolina, that this species has two broods (luring the season. The food of the Fox Scjuirrel is various ; besides acorns, and differ- ent kinds of nuts, its principal subsistence ibr many weeks in autumn is the fruit extracted from the cones of the pine, especially the long-leaved pitch pine, (l^inus paluxtris.) Whilst the green corn is yet in its milky state, this Squirrel makes long journeys to visit the (ields, and for the sake of convenience frequently builds a tempo- rary summer-house in the vicinity, in order to share with the little Caro- lina siiuirrol and the crow a portion of the delicacies and treasures of Ihf husbandman ; whore he is also exposed to the risks incurred by the thief and plunderer: for these fields are usually guarded by a gunner, and in this way thousands of squirrels are destroyed during the green corn season. The Fox Stjuirrel does not appear to lay up any winter stores there appears to be no Ibod in any of his nests, nor does he, like the red scjuirrel, {Sciurns hiidsonius), resort to any hoards which in the season of abundance were buried in the earth, or concealed under logs and leaves. During the winter season he leaves his retreat but seldom, and then only ibr a little wliile and in line weather in the middle of the day. He has evidently the power, like the marmot and racoon, of being sustained for a consider- able length of time without much suffering in the absence of food. When this animal makes his appearance in winter, he is seen searching among the leaves where the wild turkey has been busy at work, and gleaning the refuse acorns which have escaped its search ; at such times, also, this squirrel does not reject worms and insects which he may detect beneath the bark of fallen or decayed trees. Towards spring, he feeds on the buds of hickory, oak, and various other trees, as well as on several kinds of roots, especially the wild potato, {A/tios luherosu.) As the spring advances farther, he is a constant visitor to the black mulberry tn .•, {\forus rubra,) where he finds a supply for several weeks. From this tunc till winter, the fruits of the field and forest enable him to revel in .■tbiindance. Most other species of this genus when alarmed in the woods innufdiately betake themselves to the first convenient tree that presents itselli — not so FOX SQUIRRKL. wifh rho F„x Scnirrel. When ho is awaro ol' l.Hn, ..iscovered whilst 1 ho «ro„nc he push.s ,,i....„y for a hollow tree, which i.s oOen a quart of a m.le chstanf, and it n^iuire. a .^ood do., a man on hors.-l,,.' ,, . very.sw.(t runnn-, to induce him to alter his eourse. or co.np.d hi.n to a cen any other tree. When he i.s silently seated on a tree and in.a.i.'s ..mse unperee.ved ly the p,.rson approaching hin., he sud.lenly spreads un.se .„y on the liu.l. ,en.ly n.ovin. to the opposite sid.- o.L by th. stratagem escapes detection. When, however, he is on a small tree and IS made aware of being observed, he utters a few querulous barkin^^ notes, and uumediately leaps to the ground, and hastens to a more secure retreat. If overtaken by a dog, he defends himself with great spirit, and IS often an overuuttch for the small terriers which are used for the purpose 01 treemg hmi. ' ^ ' He is very tenacious of life, and an ordinary shot gun, although it ma- wound hun repeatedly, will seldom bring him down from the tops „ th; h gh PUJ.S to wh,ch he retreats when pursued, and in such situation nfle IS the only certain enemy he has to dread. This Squirrel is seldom seen out of its retreat early in the mornin^ and evemng. as ,s t e habit of other species. He seems to be a a'^ris and u.ua ly makes his appearance at 10 or ,1 o'clock, and retit^s to hi^ om,e e long before evening. He does not appear to indulge so n" en |y n> the barkuig propensities of the genus as the other and smalhr 'ped Th,.s note, when heard, is not very loud, but hoarse and gutteral i^ oasdy domesfc^Ued, and is occasionally seen in cages, but is less act ve and sprightly than the smaller species. As an article of food, the Fox Squirrel is apparently equallv good with any other species, although we have observed that'the litt e C^ o i . qu.rrel ts usually preferred, as being more tender and delicate. W 7 rkL7or""'''' are very abundant, men soon become surfeite.l with generally considered a great delicacy. This species, like all the rest of the squirrels, is infested durin^ the tiri":r^ i ;? ^""""-'-^ '^^^-^ ^''-"■-^' -'-•'> fastenm ;; ,'; on t neck or shoulders, must be very annoying, as those most a^-eeted i oweTler ""•'"?■ '7 '^"" ''-''' '■•• ^'''''- ^•"" -^" "'-"--' m the oZ; "'"t ? '"'•■•"'"" '■'"" birds of prey and wild beasts pau > of owls, so destructive to the Cnrolina squirrel. We have seen it >. defiance to the attacks of the red-shoulderil hawk (fVe wl ' VOL. ili^— lfi( ff^' las pox sgnuuKi. : It and opoH \vo()(!«, to vvliiohtlie liix mid wild «'at Mildoin n-sort, during (In iniddio of fho day, ho thiif iiiiiii is iiliiiost (lii> onlj- riuiny it \im to dnad. <;KO«IRAfllH',M, ItlMIHIIIHIION. This spocics IN sdid in ixist xpniitiKly in NfW Jcrsry. Wr linvc not oli- Hrr\«'d i( (iirtlii>r iiorlli tlmii ViiKiniii, n<n- could \v«- lind it in ilir imoiiii- tuiiioUH districts ol'tlmt stalo. In the pine (iircsis ol' Noilh ('nidlin.i, il becomes more coniiuon. In the middle and maritime districts of S.nlli Caroliiin it is almost daily met with, although it cannot he said lo he a very abundant species anywhere. It exists in lieorKia, Alaliama, Missis- sippi, Florida and Louibiuim. ORNRRAI, RKMAHK8. This Squirrel has been fr^ lueiitly described under dillerent names, [{.mo appears to be entitled to the credit of hcviii>,' bestowed on it the earliest sjiecilie name. Gmei.mn, in 17SH, mimed it S. ntfpinu.s. The black squirrel orCATBDUv is the black variety of the present specios. 189 GENUS C01VI)YLl/llA.-I,,u«„. OKNTAI, KOIlMUr.A. Incmvr - ; Caninr. ^~-\; Molar^ - An Mm.;.,., I„n... „x.r,„„i.y ciliat.,1 ; ,.ar,, „„„,., ,„,„„„, „„„„ , !::L';;:;;;'.""'^ - '""•'""■ '"-«' «-'«.i.«-.K™„ Jhi;,.:::i' (M...IUS) ,,„,l W5, (ct.Kla) " luu.l.l,,.,! mil " There is Ua one wdl .l.tonni..., species of this .onus at present known. CONDYLUkA CKISTATA—LiNN. CoMMdN Star-IVoheii Mdlk, PLATK LXLV C. narihus c/iruncuiat..s ; chu.Iu .,« pc..»> breviore • v«II.., . dnereo, nigricans, suhtus clilutior. ' ^""' "'"*'="'''' CIi/.K/i(,-l'ERfl. SYNONYMES. Kouttx ruisTAT(T8, Linii., Ed. 1*2 p 7'{ I-N. .M.«„ MO..E. l^.„„a„t^s Hist Q..a.l., >.,) ..„ p. 2^2 t„ 90, f. 2 Pennant's Arct. Zo,,]., v.,i. i., „ 140 iALPA I-ONOICAUDATA KUX. Hyst., «.,>.. i, ,, 188 ' Lo.u.,..,„ Mo... a,„d,.ura a lo..,u..,,„..ue, .>.... Ma.am., f. i., p. ,58 ^ Undyiura cnstata, Harlun, p. y(}. ' '^ ''• " (Jodm. vol. i., |), 100. J " C. inacroura, Ifarlan, p. ;«). C longip^uduta, Uichiu-dsonFaiinn n 1^ r> - " C. cristata, Do K.,. N. Ilist N J.'p lb """"™' '^ "^ I: ' l.i' 140 STAR-NOSED MOLE. DESCRirnON. r\.4 In the upper j;i\v there are two larfje incisive teetli hollowed.in Ironr i.i tlie shaiK» ol' a spoon. The next tootli on each side is Ion-;:, |)oinfe(l, coni- eal, with two tubercles, one before and the other behind at the base, re- seinl)lins: in all its characters a canine tooth : these are succeeded by live small molars on each side, the posterior one heim; the larirest. There are three true molars on "ach side, with two acute tubercles on the inner side —the first or anterior of these molars is the largest, the second a little smaller, and the third or posterior one the smallest. In the lower jaw there are four large incisors, spoon shaped, and bear-ng a strong resem- blance to those in the upper jaw. The next on each side are tolerably long sharp, conical teeth, corresponding with those above which we have set down as canine. The four succei aing teeth on each side, which may be regarded as false molars, are lobed and increase in size as they approach the true molars; the throe molars on each sit! > resemble those above, hav- ing two folds of enamel forming a point. In the shape of its body this species bears a considerable resemblance to the Common Mole of Europe {Taljxi Eurojmi) and to Brewer's Shrew Mole {Scolops Brewcrii); in the indications on th(! nose, however, it dilfers widely from both. The body is cylindrical, about as stout as that of our Common Shrew Mole, and has the appearance of being attached to the head without any distinct neck. Muzzle, slender and elongated, termi nated with a cartilaginous fringe which originated its English name — 'he Star-nosed Mole. This circular disic is composed of twenty cartilaginous (ibres, two of which situated beneath the nostrils ;ire shortest. The eyes are very small. Moustaches, few and short. There is tin orifice in place of an external ear, which does not project beyond the skin. Fore feet, longer and narrower than those of the; Common Shrew, feet longer and narrower than those of the Common Mole; palms, naked, covered with scales ; claws, flattened, acute, channelled beneath ; hii d extremities lon- ger than the fore ones, placed far back ; feet nearly naked, scaly; tail, sub- cylindrical, sparingly covered with coarser hair. It is clothed v/ith dense soft fur. COLOUR. Eyes, black ; nose and feet, flesh colour ; point of nails and end of car- tilaginous fringe, roseate. The fnr on the whole body, dark plumbeous at the roots, and without nny amuilatiotis. (Ice|)ening towards the apex into a brownish black. In some shades of liyht the Star Nose appears perfectly black throughout. On the under surface it is a shade lighter. In the- I STAR-NOSED MOIA'.. Ul I i colour of the feet we have seen some variations: a specimen before us has dark brow.i feet, another pale ashy brown, and a third vdlowish whit^ ; the majority of specimens, however, have their feet brownish white. One specimen is marked under the chit,, throat and neck with light yellowish brown, the others arc darker in those parts. Inches, 5 3 i DIMENSIONS. From point of nose to root of tail Tail From heel to end of claw - - . . Breadth of palm HABITS. As far as we have been able to ascertain, the habits of this species do not differ very widely from those of our Common Shrew Mole. We doubt however, whether its galleries ever run to so great a distance as those oi the latter animal, nor does it appear to be in the habit of visiting hi-^h grounds. It burrows and forms galleries under ground, and appears "to be able to make rapid progress in soil earth. Its food is of the same na- ture as that of the Common M )le, and it appears to prefer the viciniry ot brooks or. swampy places, doubtless because in such localities earth worms and the larva; of various insects are generally abundant. The proper use of the radiating process at the end of the nose has not been fully ascertained, but as the animal has the power of inovin- these tendrils in various directions, they may be useful in its search after worms or otlier prey, as is the moveable snout of the Shrew Mole. When con- hned m a box, or on the floor of a room, this Mole feeds on meat of almost nnj kind. It is not as strong as the Common Mole, nor as injurious to the larmer, since it avoids cultivated fields, and conlines itself to mea^lows and low swampy places. During the rutting sr ason the tail of the Star-no«ed Mole is greatly en largeJ, which circumstance caused Dr. Harlan to describe a specimen taken at that season as a new species, uinler the name Condylura macrnitfd. J)r. CJouMAx'. account of the abundance of this species does not coincide with our own experience on this subject. He says, "In many places it IS seanvly p-ssibk- to advance a st,.p without breakin^^ down their -ralle- r'.'s. by which the surface is thrown into ridges an.! the .uriace of the green swani in no slight degree disliKured." Wo have sometimes sup- posed that he might have mistaken the galleries of the Common Shrew ^f i! 'Hi 142 STAR-NOSED MOLK. i ! . Mf.Ie for thos.> made, by tlu^ Star-Nose, as to us it has always appeared a rar(> species in every part of our Union. In a ti'w localities where wt^ were in the habit, many years a^o, of ob- taining the Star-nosed Mole, it was always found on "the banks '>f rich meadows near running streams. The galleries did not run so near the surface as those of the Connuon Shrew Mole. We caused one of the. gal leries to be dug out, and obtained a nest containing three young, appa- rently a week old. The radiations on the nose were so slightly developed that until we carefully examined them we supposed they were the young of the Common Shrew Mole. The nest was spacious, composed of withered grasses, and situated in a large excavation under a stump. The old ones had made their escape, and we endeavoured to [)reserve the young ; but the want of proper nourishment caused their death in a couple of days. The specimen of the Star-nosed Mole, from which our plate was drawn, was sent to us by our highly esteemed friend Jamks G. King, Esq., having l)een captured on a moist piece of ground at his country seat in New Jersey. opj)osite the city of New-York, GEOORAPinCAI, DISTRHJUTION. This species is Ibund sparingly in all the northern and eastern states. Dr. Richardson supposes it to exist as far north as Lake Su- perior. We obtained a specimen iive miles from the Falls of Niagara, on the Canada side, and have traced it in all the New-England States.' We received specimens from Dr. Brewc.r, obtained near Boston, .-nd from W. O. AvRES, Esq., from Long Island. We caught a lew of these animals near New- York, and obtained others from various parts of the state. We saw a specimen at ^'ork, Pennsylvania, and found another at Frankfort, east of I'hiladelphia. We captured one in the valleys of the Virginia' iMountains, near the lied Sulphur Springs, and received another from the valleys in the mounlains of North Carolina, near the borders of South Carolina, and presume it may follow the valleys of the Alleghany ndge as far to the soulh as those latitudes. We have never found it in South Ca- rolina or Georgia, but to the west we have traced it in Ohio and the northern parts of Tennessee. OENERAI, REMARKS. We have been induced to undertake a careful examination of the teeth of this species, which forms the type of the genus, in consequence of the wideiliti; reiices existing among authors in regard to the characters of the iccth. Dkmarkst ga\c six incisors above ;ind lour below in the under ja,w star.nosb:d mole. 143 cheek-teeth fourteen above and sixteen beneath. In this arrangement he IS followed by Harlan, Gudman, GRiFFrn., Db Ka7 and others. The de- scription of the teeth, by DrsMA,u«r, is very accurate, and so is the very recent one of Dr. Dk Kav. F. Cnvncu, on whose jud.anent, in regard to cliaracfers Ibunde.l on d.Mi.ition, we would sooner rely than on that of any other naturalist, has on th.. other hand, (/;..v dents dcs mmmifSrcs, 182.1 p. 5G,) g-ven descriptions and figures of th(^se teeth, there being two in- ciswe, two canine, and sixteen molar above, and two incisive, two canine and fourteen molar below. Our recent examination of a series of skulls IS m accordance with his views, and we have adopted his dental arrange- ment. The dilFerence, however, between these autiiors is more in appear- ance than in reality. The incisors, canine, an.l false molars, in their cha- racter so nearly approach each other, that it is exceedingly dilficult to assign to the several grades of teeth their true position in the dental system. LiNN^us described this species under the name of Sorex cristatm in 177(5, (12th edition, p. 73) ; Pk.xant, in 1771, gave a description and poor figure of what he called the Long-tailed Mole ; and in 1777, Euxlkiien bestowed on the animal thus figured, the name of S. longicandata. 1 knnant's specimen was received Irom New- York, and although it was badly figured it was correctly characterized " Long tailed Mole, with a radiated nose," and in his " Arctic Zoology " he describes it as " the nose long, the end radiated with short tendrils." The whole mistake we con- ceive was made by Desmarest, whose work we have found exceedingly inaccarate, misled, probably, by Pennant's figure, without looking at his description. He gives one of the characters '' point des crates namlcs» when Pennant had statedquite the reverse. Hence the error of Harlan ' whose article on Comlylura longicandata is a translation of Desmarest We leol confident that this supposetl species must be struck from the list of t.-ue species in our Fauna. The Condylura macroura of Harlan, {Fauna Americana, p. 30,) was re- garded as a new species, in consequence of a specimen with the tail greatly enlarged. It was a second time published by RrcnARi.soN, who adopted Harlan's name; Gouman first suggested the idea that this might be traced to a peculiarity in the animal at a ,,articular season. It IS known that a similar enlargement takes place annually in thfl neck ol the male deer during the rutting season. We have examined several specimens where the tail was only slightly enlarged, and the swelling was just commencing, and we possess one where one half of the tail from the root is of the usual large size of C. macroura and the other half towards the end is abruptly .liminished so as tJ I I t 144 8TAR-N()Si;i) MOLK. leavo one Imlf of Iho tail to ,l,.si>,M.,.(„ „, ,h>w sp.M.ics „n.l (1„. othrr nuir Ibrciiif,' it baolf to its l.-ili.M.dr plan, i.i tl.r systmi oC ..at.im. Tl.o singular rl.ani<-t.T (kn<,l,l.,.,l tail) on winch this (Jmns was , r- roni-ously lomKlrd should sii-rrsi, to the naturalist tho i.c-.-ssiiy „C cau- tion. 'l'h.< tails of ,,ua(lru|).Mls in drying ollrn assume a v.-ry dilllMvnt shajH' Iroui that which tlioy oii^Mnally possessed. This is "rspcciallv the cas„ anions the Shivws and u.ic.'. that an; dcscril.,.,! IV.. u. .iricd speoinii-ns, as square-tailed, angular or knobbed, whereas in nature tliii tails Were rouud. u.. ' . .Jtwwei.aii WW J GENUS SOREX.-L1NN OBNTAL FORMULA. lncm.,\, Utcralinc^s^ve or false Canmr, from'Jlt; Molar frrnn ? '^f . from ao to 34 leeth Fncisivo teeth in the upper Jaw in.lentcd at thoirba.se; in the lower pr..cee,h„. hor.onta.ly from their aveoii an,l turned up;ards owll' therp,„„ts where they are usually of a brown eolour/ lateral ^ or hUse can.ne. eonieal, s.nall, shorter than the cheek-teeth Muzzle and nos,-. much elongated ; snout, moveable. Ears an.I eves «mal; pendactylous; nails, hooked. A series of glands along the hnk' exu.hng u scented unctuous matter ' fiell'lt'"'" "'"" '•' '"■'"' '"'" ^^'^ '^^^^•" --' ^--' a Shrew. Authors have described about twenty-three species of Shrews twentv ex.su.g on the Eastern continent and thirteen in N. America. Z! ot th..se spec.es are not as y.-t determin,.!, we can scarcely doubt We know no genus in which the American naturalist has a greater prospect of success in adding new species than that of Sorex *l ll if. r 1! SOREX PARVUS.-.SAT Say's Least Shrew, PLATE LXX. vol.. II, -in. illi HAY\s ii;a.st SIIIUIW OIIAKAinKRH. /'()(/(/ ii/kmv biownish <tsh, nitininis lutinj/i. 'I'vrl/i hlitch, iml short iiilhci/liiiiiricul. XVNONVMKM. I A -^OIUX I'AUVIiti S:iy, Lttlljj's l'',\|ii'(l., \ol I . I> KIM. ' " Liiisl)}', Am. .Imii'iml, vol. xxmx., |». ;iH8. " Ilarliin. )). •.»«. <mmIi«hii, miI. i., |i. VH. |il., fig. 'i, *' " Uck.iv. Nat. llisl. N. \ p. ID. niwcKin ION. URN r A 1. H Y ' r k m . Im'tsivt ' ; Lnlmil inrisiir ; Molar 1-4 4-4 :«•>'. In ll\t' npp(>r j.'wvs (ln> incisors juc miwiII. iiuicli hooked, iiiid Imvc !V posterior lulx ; llic siici't-i'dini: lMl("ri\l i'licisors, tii'c iiiimitc, coiiiciil. i\ot lohcd. till' 'wo imtcrior ones miiic!i llii' larjicsl. 'riic tirsl ^jriiidcr is siiiallor than tlic sccoiid .uid lliird, (lie fourth is lh(< sinallcsl. In fh«' hiwcr.jaw tlu' incisors arc a li1th> smaller llian those in tlie npper They nvv iniicli nior<' hooked and have eiicli a lar^e |)Osteri(;r hihe. The two hiteral incisors are small not lolied — tin- >,'rinder.«i have each i \V0 sharp points ri^in^j ahoxe tlic enamel. 'l"he second loolli is larnesl. and the third smallest. ,\(isc slender and lonir. l>iit less .so than that ot" inanv other species, es|)eciall\ that of N. /miiiinixlris i.nd N. I{irh<tnl- tot.ii. M ii/,.'.le, hi-lohate, naked ; moustaches, luuncrinis, Ion;;, reaching to ihe slK)ulders ; i)ody, slender; eyes. vt>ry small, ears, noiu' ; the audi- forv oiit>i-\inii' heinsx covered hv a round lolie. wilhoul anv I'olds uhovo ; t'Tt spiirjely clothed with minute iiairs. palms naked ; tail thickly (dotlied with minute h.-iirs, tur, short, close, soft, and silky. eoi.oi'R. .Ml the teeth are nt their points inten.sely hl.aok ; \vnisker.«<, wliite :uid black; point of nose, feet, and nails, whitish; the hair is, on the upper surface pluMil)eous from the roots, and of an ashy-hrown at the tips; a shade lifrhter on the under surl'ace : under the chin it, i.s of an a-hv >;rey ^jraduallv bh-ndin;:; with the colours on ilic buck. HAVH IJOAHI- HUHKW 147 DIMKNMIONH. rnmi point, oC im.s»? to root of tail Tail. Inchiw 2 IIAniTH. TliiH littl(, (iiTiitiirc. to wliicli III). „1 VVilS lirsl. follic Iforky Mount i( \\fts I'oiiiiil ill ••ii|>liirc(l hy Mr. 'IV IAN l{. I •ovf niitrK- wjiH (itt(i(!|ic(| |,y Sav, 'I'.Ai.i;, (liirinii: \. l''M)k III, the pifilf. redder, ;u„| 'lins, lit lOiiKiiiccr (Juiilotunrnt on tli pilliill exmvdle.l lor (•ut.!llin^r wolves. 'ON'iM Hxpediiion M iN.Moini, wliere on ••xntninintr (lie pit, inieM.le.j (or llie d nii^ine tlie nstoni.slnoe,,! of ihe (, iintcr III pr.'il'-ies, when, iiislead of ll estrilelion oC (I,,. S.-lV/l'T provvlf pereeivrwl (lijs, ||,r |,easl SI 'I'll 'trill lialiils lo ll Illy lo wliiidi this Shrew I.eh We has orex, found I le mole seen a (i hill. "■ f,'.iine that he intended to enliap, ■|.V riiiiiiiiii,' (icrosH the holloni. 'ttKH. i.s .soinewhal, allied in (or,,, irew, liiiiii i"'iiiy speeie.s are now prohahly extinct. iiKiiK'iit oC a fossil icnninder of '' y our ytxiwtr fri,.„d |),.. [ nnnintr i-,.^ri„„ adjoining Lake S IIDll mist. h;i,ve !)(■( iipenor, fro,,, the X' tooth of a Mu,sri'., of New- York, in iho ■" '" l<-iist n, yard h.n^r, and no do„| size of whieh. thi uni- nnrnivoroiis te,.th, a ll.nnidahle, heu.st of )t w l.^ Wl th it!' mid winiiiH of a eorrespondii |>''<7 ; whether it hud nilioii, is a, mutter of of ;;,'e(do«;Js|,s have tin i/e to feed upon, in its d insf'cts inlial.iliinls of the aiieient mere eonjeeimc. us even the, wonderful d ■own liiil Mill,. Ijjriit „„ ,1 • y Utlfl ironc. iseovei-icH foi world. ultlioiiL'l If modes of life of tl ind '"••'III time to lim,. |,v | t,'h some; whole skidetons 10 uro 'I'lie Least Shrew fei'd.N leir res(.arelies. or uiiy deud hird or heust tliut 111)1)11 ins(-(!ts uiid lurvie. wor It ul «'!irth, hilt s( so cuts seeds und j,'ruins of ditf it muy ehanee to diseo lis und the IJesh ver. •■ront kinds, [t hurro ll 'k' nade, and rii •ks its food ,„„re upon the siirfuee of tl lis with euse scmir. birds of |,|-,.y |,„||| uroiind its In ws in tho 10 tcround tliun irrow about fenei^s und | m-ekiiiH: its food '•<■ upon tlie Shrew, whilst it is i»| o<rs. smell, it i on the (,'russ, (, s commonly |,.c, .^n,.^. | nt -'IS it has u miiskv. dis; |)iuyinir or leill'r it,'reeable We killcfl, to rot sun on III "'^■•' l'i'^>^'''l "P .•' Kood many of these liitl.. ,p,a,lru„ed H-aruncc hud b..,Mi killed by either cuts owl on tho (ijround. U.I a PI dl irises from a seereti I» s or hawk^ which tf ic sid(.s of the ai on .•xud..d from jr|ands whicl Tl MS INI.O), This secivtion, like that o| liii.il ((Jcolfroy, Mem. Mils. If I are pluocd ist. Nut., Vol. i.. au-e, the scuson. &c most uiu inimals, varies acconiuiKto tho I lirovuiJs more i.. fnal»H ,i,an fema -;i ' ^111 148 SAY'S LEAST SHREW. Of the mode in which the Least Shrew pa.s.ses the winter we have no very positive information. It is capable of sustaining a great degree of cold. We have never found one of these animals in a torpid state, when examining burrows, holes, or cavities in and under rocks or stones fee, for the purpose of ascertaining, if possible, the manner in which they passed the winter. We have seen minute tracks on the surface of the snow where it was lour feet in depth in the Northern parts of New- York, which we ascertained were the foot-prints of a Shrew which was afterwards captured, although we cannot be certain that it was this species. It had sought the dried stalks of the pig weed .{chenopo- (bum album) on which the ripened seeds were still hanging and upon which it had evidently been feeding. We are unacquainted with any other habits of this minute species: GEOGRAPIIICAI, DISTRIBUTION. If authors have made no mistake in the designation of this species as we strongly suspect, it has a wide geographical range : according to Richardson, it is found as far to the north as Behring's Straits. I'he specimens from which our figures were taken, were obLined in the im- mediate vicinity of New- York. Dr. Dekav, in his Nat. Hist, of Nrw- York, p. 20, mentions that although he had been unsuccessful in obtaining it in New- York, a specimen was found in Connecticut, by Mr. Lixslky'! We have not ascertained its southern range, all we know'of its exist- ence in the west, is from Say's short description of the only specimen obtained west of the Missouri. GENERAL REMARKS. All our authors seem anxious to obtain Say's Least Shrew, and we have seen dozens of specimens of young Shrews of several specie's, labeled in the cabinets "Sorex Parvus." Although there were few more accurate describers than Say, yet his description of S. parvus, is too imperfect, to enable us to feel confident of the species. There was no examination of its dental system, and his description would easily apply to half a dozen other species. ' The characters by which we may separate the different Shrews are not easily detected, they very much resemble each other in form, colour and habits ; they are minute nocturnal animals and not easily procured. There exist but few specimens in our cabinets to enable us to in- stitute comparisons, and a century will pass away before all our species ure discovered. We have very little doubt, that when the species which SAY'S LEAST SHREW. 149 was obtained in the far West and described by Sav and that nf R BO. from the far north, and ours from the 'vie n^ of NeJ Yt'"''" Ob amed and cornj.ared and their dental system caret M^"' ^ w.l. be ascertained that they are three diJti cTs^ec '.„d oT ' '' cessors will be surprised that the old authors gave o t^^ Shr '"" wide a geographical range. ^ '^^"'''^' -'^ Say's description is siihim'n r«- above b.„w„li„i„e.„„: £l„ '"IZZla TrT' " '^' ears concealed, whisker, 1„„, ,.'"'"'"""' '""^ elongated, eye, and imes. of tail rt ?(; " d . •'' inches lour Ho„; d„:t:;:;,H ^:raz: a^nLrTenrr'-r" :: "rr'^ a...l body .„, inches three liaea, tail one Lh '' "" °' """^ 150 if CANIS L. TUANS— Sat. Prairie Wok. — Hapkino Wo^r. PLATE LXXI.— Male. C, oano cinerous nigris et opace puivo-ciii imeo-variegatus ; lateri- bus pallidiori.us; fasciS taise Idta brevinigrS; cauda rectfi fusiformi cinfraceo-cinnameoquc variegata apice nigra. CHARACTERS. Hair cinereous grey, varied ivith black above and dull fulvous ciima- mon ; suhs pahr than the hack, obsoletel,/ fasciate, with black above the lesrs : fail straight, bushy, fusiform, varied with grey and cinnamon, Up black. y ^ SYNONYMEf Small Woi vks, Dr Praly, Louisiana, vol. ii., p. 54, Prairie Wolf, Gas-,. Journal, p. 50. Pkairie Wolf and Bukhowivo Doo, Lewis and Claik, vol, i., p. 102, 13, 203, vol. iii., pp. 102, 1.36, 20.3. " " Schor,!(.r,ift's Travels, 285. Cants Latravs, Say, Long's 'Ixped. i,, p. 108. '■ " Harl.m, p. 33. " God., 1 vol.. 26. " " Richardson, F. B. Ar. 76. Ltcisous Cajottis, Hamilton Smith, Nat. Lib., v iv., p. 164, p. 6. • DESCRIPTION. The Barking or Prairie Wolf is intermrdinfe in size, between the large American Wolf and the grey Pox {V. vinrinn/niis.) It is a more ' dy animal than the former, and possesses a cunning fox-llKr countp ,ince. In seeing it on the prairies, and also in menageries, in a state of domestication, \v,! have often been struck with its quick, restless manner, and with many traits o'' haracter that reminde.i ^ of sly reynard. The nose is sharp and pointed ; nostrils moderately dilated and naked —the upper si,, face to (he forehead covered with compact short hairs; eyelids placed obliquely on tlic sides of the head. Eyes rather small— I'KAIUIb: WOLF. 151 rr.mstaches few, very rigid, extending to the eyes, four or Hve stiff nairs rising on the sides of the neck I,, low the ears. Head rather I road ; Ears, erect, broad at base, ruanin- to an obtuse point, ciotJied with compact soft fur in which but few of the longer hairs exist ; body, toler- ablyst.M.t; legs, of moderate h-ngth, shorter in proportion frhan ihose ot the common Wolf; Tail, large and bushy, composed like the cover- mg ol the body of two ki.uls of hair, the inner soft and woolly, the outer longer and coarser and from two to three and a half inches in len-th Soles of tiie feet naked, nails rather stout, shaped Ilk- those of 'the' (log. The whole structure of the animal is indicative of spc.ul, but from Its compact shape and rather short legs we would be led to suppose that U was rather intended for a short race than a long heat. COLOUR. Nostrils, around the edges of the mouth, and moustaches, black ; upper surface of nose, and around the eyes, reddi«h brown ; upper lip, around the edges ot the mouth, and throat, white; eye-lids, yellowish ' white ; hairs on the forehead, at the roots reddish brown, then a line of yellowish wiute tipped with black, giving it a reddish grey appear- ance. Inner surface of the ears (which are thinly clothed with hair) wh^te; outer surface, yellowish brown; the fore legs reddish hrown with a stripe of blackish extending from the fore shoulder in an irreg- ular black line over the knee to near the pans. Outer surface of the huid legs, reddish brown, inner surface a little lighter. On the back the sort under fur is dingy yellow ; the longer hair from the roots to two-thirds of its length black, then a broad line of yellowish brown, broadly tipped with black. Neck, reddish brown • throat nnd all beneath, yellowish white, with bars under the throat and on the chest and belly of a reddish tinge. On the tail the softer hair IS plumbeous, the longer h;iirs are like those on the back, except on the tip of the tail where they are black for nearly their whole length. The description here given is from a very fine specimen obtained at San Antonio ir- Texas. There is not however a uniformity of colour m these animals, although they vary less than the large wolves. The specimen whicU Richardson described was obtained on the Saskatch- ewan. We examined it in the Zoological Museum of London : it differs in some shades " colours from ours -its ears are a little shorter Its nose h>ss pointed, and the skull less in breadth-but it was evi- dently the ..„.,. species, and could not even be regarded as a distinct variety. The m.uiy specimens we examined and compared in various tints of colour differed considerably, some wanting the brown '^' H Ei'**' 1 i > W^' J 162 PRAIRIE WOLF. lints, being nearly grey, whilr niiiny liiul \>\ii.cM niarkinfi!;. on <ho shin and forelegs which were iil)s«'nt in others. In nil descriptions .»t wolves, colour is a very uncertain guide in the designation of species. DIMKNStOND. * From point j; m« t root of tail . Tail vertebr »•, .... Do. to end of liuir Height of ear, .... lireudth of do. at the base, From heel to end of longest nail, Point of nose to corner of eye, . Breadth of skull, .... Fore shoulder to end of longest nail, Breadth across the forehead. n. Indian. 2 10 • 11 1 3 • 8 • 3 , 6 • Si • 4 1 1 . 2i HABITS. We saw a good numl)er of these small wolves on our trij* up the Missouri river, as well as during our excursions through those portions of ihe country which we visited ))ordoring on the Yellow Stone. This species is well known throughout the western parts of the States of Arkansas and Missouri, and is a familiar acquaintance of the " voyagcurs" on the upper Missouri and Mississippi rivers. It is also found on the Saskatchewan. It has mueli the appearance of the common grey Wolf in colour, but ditfers from it in size and maimers. The Prairie Wolf hunts in packs, but is also often seen prowling singly over the plains in search of food. During one of our morning rambles near Fort Union, vrc happened to start one of these wolves suddenly. It made off at a very swift pace and we fired at it with- out any effect, our guns being loaded with small shot at the time ; after running about one hundred yards it suddenly stopped and shook itself violently, by which we perceived that it had been touched ; in a few moments it again started and soon disappeared beyond a high range of hills, galloping along like a hare or an antelope. The bark or howl of this wolf greatly resembles that of the dog, and on one occasion the party traveJIing with us were impressed by the idea that Indians were in our vicinity, as a great many of these 'volves were about us and barked during the night like Indian dogs. We were all on the alert, and our guns were loaded with ball in readiness for an attack. PRAIRIi: WOl.P, 15a In Tj'Xfis th<- Pmi.i.« Wolvrs arc pcrhapM more abundant than the other species; ihey hunt in packs of six or ..it;ht, which are se.a to most ad- vantii-e ia iIk- eveiiinii', in piirauit of deer. It is anuwinR to bco tlien; cut across the curves made by the latter when tryinj,' to e:Hca|)e, the hindmost Wolves thus saving some distance, and finally striking in ahead of the poor deer iind surrounding if, when a single Wolf would fail in the attempt to capture it. liy its jiredatory and (h'siruclive habits, this Wolf is a great annoyance to the settlers in the new territories of the west. Travellers and Imnters on the prairies, dislike it for killing the deer, which supply these wanderers with their best meals, and furnish them with part of thrir clothing, the buok-skin breeches, the most durable garment, lor the wo- 'h or plains. The bark or call-note of this Wolf, al- though a wild sound u. the inhabitant of any .settled and cultivated part' of the country, is sometimes welcomed, m it often announces the near api)roach ofdaylight; and if the wanderer, aroused from his slumbers by the how- ling of this animal, raises his blanket and turns his head toward tli east, from his camping-ground und<-rneath the branches of some broad spreading live-oak, he can see the red glow, perchance, that frir.ges the misty morning vapours, givi-g the promise of a clear and cairn sun- ri.seinthemildclimateofTexa. renin th. . oft, of winter. Should day-light thus be at hand, the true hunter 1. .( once a-foot, short .space of time doer; he recpiire for the duties of the toilet, and soon hi. has made a fire, boiled his coffee, and broiled a bit of venison or wild turkey. This Wolf feeds on birds, small and large quadrupeds, and when hard pressed by hunger, even upon carrion or carcasses ol' buffaloes, &c. It is easily tamed when caught young, and makes a tolerable com- panion, though not gifted with the good qualities of the dog. We had one once, which was kept in a friend's store in the west, and we discovered it to bt; something of a rat catc+ier. This individual was very desirous of being on iriendly terms with all the dogs about the premises, especially with a large French poodle that belonged to our friend, but the poodle would not permit our half-savage barking Wolt to play with him, and r'enerally returned its attempted caresses withan angry snap, which r-., further. friendly demonstrations out of the question. Ors day we missed our pet from his accustomed place near the back part of the ware-house, and while we were won- deriP'; what had become of him, were attracted by an unusual uproar in the street. In a moment we perceived the :mise was occasioned by a whole pack of curs of lu :., and low degree, which were in full cry, and m pursuit of our Prairie Wolf. The creature thus hard beset. VOL !!. — 2(1. a^Kii ^ ' ^^1 .(- j i] ( m> 154 PRAIRIE WOLF. before we could interfere, had reached a point opposite a raised window and to our surprise, made a sudden spring at it and jumped into the warehouse without touching the edges of the sills, in the most admir able manner, while his foes were completely baffled. After this adventure the Wolf would no longer go out in the town and seemed to give up his wish to extend the circle of his acquaintance. The Barking or Prairie Wolf digs its burrows upon the prairies on some slight elevation, to prevent them fr^^m being filled wifh water. These dens have several entrances, like those of the red fox. The young, from five to seven and occasionally more in number, are brought forth in March and April. They associate in greater numbers than the larg. r Wolves, hunt in packs, and are said by Uiciiardson to be Hecter than the common Wolf. A gentleman, an experienced hunter on the Saskatchewan, informed him that the only animal on the plains which he could not overtake when mounted on a good horse, was the prong-horned antelope, and that the Prairie Wolf was next in speed. All our travellers have informed us, that on the report of a gun on the prairies, numbers of these Wolves start from the earth, and warily approach the hunter, under an expectation of obtaining the off^al of the animal he has killed. The skins of the Prairie Wolves are of some value, the fur being soft and warm ; they form a part of the Hudson Bay Company's exportations, to what extent we are not informed. RiciiA.iDsoN says they go under the name of cased-wolves skins, not split open like those of the large Wolf, but stripped off and inverted or cased, like the skin of a fox or rabbit. GEOGRAriUCAL DISTRIDUTION. According to Richardson, the northern rar ge of this .species is about the fifty-fifth degree of latitude. It is found abundantly on the plains of the western prairies and sparingly on the plains adjoining the wood' shores of the Columbia river. It exists in California, and is found in Texas and on the eastern side of the mountains in New Mexico. We have traced it to within the tropics, but are not aware that it reaches as far south as Panama. Th(> eastern branches of the Missouri river appear to be its farthest eastern ran|>;e. PRAIRIE WOLF 165 m<t GENERAL REMARKS. There has been but little difliculty in the nomenclature of this spe- cies. Hamilton Smith, we perceive, has given it a new naine, from a specimen obiained m Mexico. The description of its habits, by LEwrs and Clarke, is full and accurate and in accordance with our own ob- servations. 166 C A N I S L U P U S.— Linn.— (Vau. Aldus.) White American Wolk. PLATE LXXn.— Malb. C. magiiitudiiie formaque C. lupi ; vcllere Havido-albo ; lu •scente. ISO cane- 1: I CHARACTERS. She arid shape of f he g re,, wolf fur over the whole body of a yellowish- white colour, with a slight tinge (f grey on the nose. SYNONYMES. WniTE Wolf, Lewis and Clark, vol. i.. p. To7, vol. iii.. p. 263. Canis Lupus, Albus, Sabine. Frank. Joiirn.. p. 0.v.>. White Wolf, Frank. .lournal. p. ;ilJ. " Lyon's Private .lournal, p. 270. Li I'us Aluus Vak. B. Wiim: Woi.i-. llichardson, F. B. A., p. 68. nESCRIPTION. In shape, thi.s Wolf reseml.lr.s all the othor varieties of lar-e North American Wolves. (The prairi<. orharkin- Wolf, a .listinet and ditfere,,^ Mpeci.>.. excepted.) It is lar,H>. ,s,out. an.! eo.npaclly l,„i|, ; ,1„. ,ani„e te«^ ;,rr Inns ; others stout, lar-c rather short. Eyo.s, small. Ears vhorf, and^tnaru^nhr. Feet, stout. Nails, strong and trenchant. Tail, lon^ and l.nshy. Hairs en the l.ody. of two kin.ls ; the nnder coat composed of .short, solt and woolly hair. inters,„.r.sed with longer coar.se hair five inches • n length The hairs on the head and lejrs are short and sn.ooth, havinc^ none of t],e woolly appearance of iho^- on othn- portions of th,. body. '^ COLOUR. The short fur ber.eafh the lonir white ooaf, yellowish white, the whole outer surface white, there is a sli.^ht ti„«c «<' «r, yish on the nose. Nails black ; teeth white. Another Specimen.-Snow-wb.u on ev..n' parr of the body except th. fail, which IS slightly tipped with I ,ck. WHITE AMKRICAN WOLF. m Another — Lijrht grey on the sides legs and tail ; a dark brown stripe on the hack, through whicii many white hairs protrude, giving it th-e ap- pearance of being spotted wilh brown and white. This variety resem- bles the young Wolf noticed by Richaruson, (p. 08) which he deuimiinates the pied Wolf. DIMENSIONS. Prom point of nose to root of tail, ])o. tail, vertebrm, ... Do. do. end of hair, Height of ear, • - l''aet Inclioa. 4 (( I 2 1 8 34 HABITS. The White Wolf is far the. most common variety of the Wolf tribe to be met with around Fort Union, on the prairies, and on the pliii.s bor- dering the Y<'llow Stone river. When we first readied Fort Union we found Wolves in great abundance, of several different colours, white, trrey, and brindled. A ^jood numy were shot from the walls during our residence there, by Edwaro Harris, Esq., and Mr. .1. G. Bell. We ar- rived at this post on the l'2th of .lane, and although it might be supposed at that season the Wolves could procure food with ease, they seemed to be enticed to tlic vicinity of the Fort by the cravings of hunger. One day soon after our arrival, Mr. Culhertson told us that if a Wolf made its appearance on tlie prairie, near the Fort, he would give chase to it on horseback, and bring it to us alive or dead. Shortly after, a Wolf coming in view, he had his horse saddled and brought up, but in the meantime (he Wolf became frightened and began to make oft", and we thought Mr. CiiLnr.HTSON would never succeed in capturing him. We waited, how- ever, with our companions on the platform inside the walls, with our heads only projecting above the pickets, to observe the result. In a lew moments we saw Mr. Cilher tson on his prancing steed as he rode out of the gate of the Fort with gun in hand, attired only in his shirt, l)reeehes and boots. He put spurs to his horse and went off with the swiftness of a Jockey bent, upon winning a race. The Wolf trotted on and every now and then sto|)])<Hl to gaze at the horse and his rider, but soon finding that he could no longer iiidubjfe liis curiosity with safety, he suddenly gal- lopped olfwith all his s])ee(l, but he waf too late in taking the alarm, and the gallant steed soon began to gain on the poor cur, as we saw the horse r.ipidly shorten the distance between the Wolf and his enemy. Mr. Cijl- iinnsoN fired oil' liis gun as a signal to us that 1.,. felt sure of bringing in 158 WHITE AMERICAN WOLF. I thcbe.ast, and althoush the hills wnv Rainrd by the fugitive, he had not time to make for the brok.n srouiul and deep rasines, which he would have reached in few minutes, wlieii we heard the erack of (h*- <,nui aixaiii, and Mr. CuLBKRTsoN <,-alloping along dexlerousiy picked up the slain Wolf willi- out dismounting from his horse, threw him across the puuunel of his sad- die, wheeled round and rode back to the Fort, as fast as he had gone forth, a hard shower of rain being an additional motive for quickening his pace, and triumphantly jjlaced the trophy of his chase at our disposal. The time occupied, from the start of the hunter, until his return with his prize did not exceed twenty minutes. The jaws of the animal had become fixed, and it was quite dead. Its teeth had scarified one of Mr. Culbeetson's fingers considerably, but we were assured that this was of no importance, and that such feats as the capture of this wolf were so very common, that no one considered it worthy of being called an exploit. Immediately after this real wolf hunt, a sham Bufi-alo chase took place, a j)rize of a suit of clothes being provided tor the rider who .should load and slioot the greatest number of times in a given distance. The horses were mounted, and the riders started with their guns empty- loaded in a trice, while iit speed, and fired first on one side and then on the other, as if after Bufi"aloes. Mr. Culbertson fired eleven times in less than half a mile's run, the others fired less rapidly, and one of them snapped several times, but as a sniq) never brings down a Buf- falo, these mishaps did not count. We were all v/ell pleased to see these feats performed with nmch ease and grace. None of the riders were thrown, although they suflered their bridles to drop on their horses necks, and plied the whip all the time. Mr. Culbertso.n's mare, which was of the full, black loot Indian breed, about five years old, was highly valued by that gentleman, and could not have been pur- chased of him for less than four hundred dollars. To return to the wolves. — These animals were in the habit of coming at almost every hour of the night, to feed in the troughs where the ofi^al from the Fort v.-as deposited for the hogs. On one occasion, a wolf killed by our party was devoured during the night, probably by other prowlers of the same species. The white Arolves are generally fond of sitting on the tops of the eminences, O!' -mfili liills in the prairies, from which points of vantage they can easily (S-cover any passing object on the plain at a consider- able distfince. We subjoin a few notes on wolves generally, taken from our journals, made during our voyage up the Missouri in 1S43. WHITE AMERICAN WOLF, I6y Thpsfi animals are extremely abundant on the Missouri river, and in the adjacent country. On our way up that extraordinary stream, we first heard of wolves being troublesome to tlie farmers who own sheep, calves, youn- colts, or any other stock on which these ravenous ucasts feed, at Jellcrson city. iIk; seat of goverment of the State of Missouri; but to our great surprise, while there not a black wolf was seen. Wolves are said to feed at times, when very hard pressed by hun- ger, on certain roots which they dig out of the earth with their fore- paws, scratching like a coinmuii ,|.,g in the ground. When t\w,y have killed a Bulfalo or other large animal, they drag the remains of the carcass to a conceded spot if at hand, then scrape out the loose soil and bury it, and often lie down on th.> top of the grave they have thus made for their victim, until urg,.d again by hunger, they exume the body and feast upon it. Along the banks of the river, where oc- casionally many Hulfaloes perish, their weight and bulk preventing them from ascending where the sho.-e is precipitous, wolves are to be seen m e..nsi(I<>ral)l<! numi)ers feeding upon the drowned Bisons. Although extremely cunning in hiding thems<.|ves. at the report of a gun \volves soon come forth from dilferent (luarters, and when the alarm is over, you have only to eoncenl yourself, and you will soon see them advancing towards you, giving you a fair chance of shooting them, sometimes at not mort^ tlian thirty yards distance. It is said that althougii they fretiuently pursue Bulfalo, &c., to the river, they seldom if ever follow them after they take to the water. Their gait and movements are precisely ilic s.une as thos<' of the common dog, and their mode of copulating, and \\w number of young brought forth at a litter is about the same. Tin- div.-rsity of their size and colour is quite re- markable, no two being cjuite alike. ^ Some (lays while ascending the river, we saw from twelve to twenty- five wolves ; on one occasion we observed one apparently bent on cross- ing the river, it swam toward our boat and was fired at, upon which it wheeled round and soon made to the shore from which it had started. At another time we saw a wolf attemjuing to climb a very steep and high bank of clay, when, after falling back thrice, it at last reached the (op and disappeared at once. On tin; opposite shore another was seen lying down on a sand bar like a dog, and any one might have sup- posed it to be one of those attendants on man. Mr. Bku. shot at it, Duttoo low, and the (ellow scampered off to (he margin of the woods,' there stopped to take a last lingering look, and then vanished. In hot w(>ather when wolves go to the river, they usually walk in ii ! It; 160 WHITK AilERICAN WOLF. li' ' I up to tlieir sides, aad cool themselves while lapping the water, pre- cisely in the maimer ol' a dog. They do not cry out or howl when wounded or wlien suddenly surprised, but snarl, and snap their Jaws to- gether furiously. It is said when sutlering lor want of food, the strongest will lixll upon the young or weak ones, and kill and eat them. Whilst prowling over the prairies (and we had many opportunities of seeing them at such times) they travel slowly, look around them cauliously, and will not disdain even a chance bone that may I'all in their way; (hey bite so voraciously at the bones thus left by the hunter that in many cases their teeth are broken olF short, and wc have seen a number of speci- mens in which the jaws showed several teeth to have been fractured in this way. After a hearty meal, the wolf always lies down when he supposes himself in a place of safety. We were told that occasionally when they had gorged themselves, they slept so soundly that they eould be approached and knocked on the head. The connnon wolf is not unfre([uently met with in company with the Prairie woW {Cauls /alrfins.) On the afternoon of the llJth of .Tuly, as Mr. Bell and ourselves were returning to Fort Union, we counted eighteen wolves in one gang, which had been satiating themselves on the carcass of a JJutfalo on the river's bank, and were returning to the hills to spend the night. Some of them had their stomachs dis- tended with food and appeared rather lazy. We were assured at Fort Union tiiat wolves had not been known to attack men or horses in that vicinity, but they will ])ursue and kill mules and colts even near a trading post, always selecting \\w fattest. The number of tracks or rather patiis made by the wolves from among and around the hills to that station are almost beyond credibility, and it is curious to observe their sa<.;ae(ty in choosing the shortest course und the most favourable ground in travelling. We saw hylirids, th(' oli'spring of the wolf and the cur dog, and also their mixed l)roo(is : some of which resemble the wolf, and others the dog. M.'iny oi' the Assiniboin Indians who visited Fort Union during our stay there, had both wolves and their crosses with the common dog in their trains, and tlieir dog carts (if they may be so called) were drawn alike by both. The natural gait of the American wolf resembles that of the New- foundland dog, as it anihlcs, moving two of its legs on the same side at a time. When there is any appearance of danger, the wolf trots oil", and generally makes for unire j'lented hilly grounds, and if pursued, gallops at a quick pace, ;;liuost equal to that of a good horse, as the WHITE AMERICAN WOLF. 161 read.!!- will perceive from the following account. On the 10th of July 18i;j, whilst we were on ii liulFalo hunt near the banks of the Yel- low Stone river, and all eyes were bent upon the hills and the prairie, which is very broad, we saw a wolf about a quarter of a mile from our encampment, and Mr. Owkn McKe.vzie was sent after it. The wolf however ran very swiftly and was not overtaken and shot until it. had ran several miles. It dodged about in various directions, and at one time got out of sight behind the hills. Thi-: wolf was captured, and a piece of its flesh was boiled for supper; but as we had in the mean time caught about eighteen or twenty Cat-fish, we had an abundant meal and did not judge for ourselves whether the wolf was good eating or not, or if its flesh was like that of the Indian dogs, which we have liad several opportunities of tasting. Wolves are frequently deterred from feeding on animals shot by the hunters on the prairies, who, aware of the cautious and timid cha- racter of these rapacious beasts, attach to the game they are obliged to leave behind them a part of their clothing, a handkerchief, &c.,or scat- ter gun powder around the carcass, which the cowardly animals dare not approach although they will w^tch it for hours at a time, and as soon as the hunter returns and takes out the entrails of the game he had left thus protected, and carries off the pieces he wishes, leaving the coarser parts for the benefit of these hungry animals, they come forward and enjoy the feast. The hunters who occasionally assisted us when we were at Fort Union, related numerous stratagems of this kind to which they had resorted to keep ofl" the wolves when on a hunt. The wolves of the prairies form burrows, wherein they bring forth their young, and which hitve more than one entrance; they produce from six to eleven jit a birth, of which there are very seldom two alike in colour. The wolf lives to a great age and does not change its colour with increase of years. GEOGRAnifCAL DISTRIBUTION. This variety of wolf is found as far north in the Arctic regions of America as they have been traversed by man. The journals of Hearne. Frankliv, Sahinb Richardson, and others, abound with accounts of their presence amid the snows of the polar regions. They exist in the colder parts of Canada, in the Russian possessions on the western coast ol America, in Oregon, and along both sid, s of the Rocky Mountains, to California on the w.-st side and Arkansas on the east. We examined a specimen of the White Wolf killed in Erie county, N. Y., about forty VOL.11. 21. H'>' 162 VVIIITK A3IKRICAN WOLU compared wUh .hose .r M:,o.,.lIZ ij '^Xr "»' "'"" GENERAL REMARK8 Cold seems necessary to produce the Wolves of white varietv a , • regions from their alf;t,i,>„.. a- . .•_ variety. Alpme "» - . Lap.:: t:ir:::ranT. ts .!;:;:, 'ir are some of thpm «rl,;f„ t cl . '""o" giey colour — there An,..e„„, European, and A. ir wZ! alXr, 7""!"^ '"t'-^^ i^ociet}. We found specimens from the Norf-m nr.i ai • °'°°'<^'^' bo.h o„„U„e«, h„,e a s,r„„, re JbL;; „ 1^ 7;?'°''^ "[ .ize, their shades of eolour differed oalv i„ ^T . ™ "'"' either eountrv and we n„,ir„ . u ^ '"' 'f™'""!"' from who shouldTe able o Id^d! , ""r""'™'™ """ *' "»"-"« 'n,o differen. ;:1, h d "a; '^di XT '" """'" "" "*" possess. " ' '"' ■""' penetration than we although we Id not when A ty. Alpine ARD informs ilour — there ame colour, smpared to th countries ig the large lent British Zoological ■ regions of 1 form and Tiens from naturalist the Wolves n than we O- 'A IMAGE EVALUATION TEST TARGET (MT-3) M/.^. /. :/ A, 1.0 I.I 11.25 2.5 ^ 1^ III 2.0 - 6" iA 11.6 -> Photographic Sciences Corporation ^ 4 V <^ \\ ^ ^\^ 'r»* 23 WEST MAIN STREET WEBSTER, NY. 14580 (716) 872-4503 % ^^ >* 163 GENUS OVIS.— Linn., Briss., Erxleben, Cuv., Bodd., Geopp. DENTAL FORMULA. Incisive - ; Canine — ; Molar — = 32. 0-0 0-6 Horns common to both sexes, sometimes wanting in the females, they are voluminous, more or less angular, transversely wrinkled, turned laterally in spiral directions, and enveloping an osseous arch, cellu- lar in structure. They have no lachrymal sinus, no true beard to the chin, the fe- mnles have two mamma; ; tail, rather short ; ears, small, erect ; legs, rather slender ; h.iir, of two kinds, one hard and close, the other wool- ly ; gregareous. Habit analogous to the goats. Inhabit the highest mountains of the four quarters of the globe. The generic name is derived from the latin Ovis — a sheep. There are four well determined species, one the Mouflon of Buffon, Atusmon {Ovis Musmon) is received as the parent of the domesticated races. It is found in Corsica, Sardinia, and the highest mountain chains of Europe. One inhabiting the mountains and steppes of northern Asia, Tartary, Siberia and the Kurile Islands, one the mountains of Egypt, and one America. OVIS MONTANA.— Desm. Rocky Mountain Sheep. PLATE LXXIII. Male and Femalk. O. cornibus crassissimis spiralibus ; corpore gracile ; artubus elevatis ; pilo brcvi rigido rudi badio ; clunibus albis o ariete major ; rufo cinereus. CHARACTERS. Longer than the domestic sheep, horns of the male long, itrong and tri- angular, those of the female compressed ; colour deep rufo\it grey, a large u)hite disk on the rump. I ' - i ! 1 ! i I :j i I ; 164 ROCKY MOUNTAIN SHEEP- SV\0NYME8. Akoali, Cook's third voyage in 1778. W iLD SuEKP OF California. Voncgus. Clavigoro. White Buffalo, McKcnzie voy. |i. 7(5. An. 1789. Mountain Goat, Uinfreville, Hudson's Bay. p. 104. Mountain Ham, McGillivary, N. York. Med. Her .sit. vol. G. p. 238. Bio Morn, Lewis and Clark, vol. 1. p. 144. 'isLim Sauvage d'AMERiQUE. Geofi; An. du. mu.-,. t. 2. pi. 00. UooKY Mountain Sheep. Warden. U. S. vol. 1. p. 217. MouFFtoN d'AMERiQUE. Desm. Mamm, p. 487. Bio Horned Sheep. (Ord.) " " Blainv. in Jour, do Physic. 1817. Ovis Amnion. Harlan. Fauna. j>. 250. The Argali, Godm. Nat. Hist. vol. 2. p. 329. Ovis Montana. Richardson. F. B. Ainer. p. 271. Ovis- PvoARjAs VAR OVIS AMMON. Griffith An. King. Spec. 873. description. Male. This is a much larger animal than any variety of our largest .sized sheep. It is also considerably larger than the Argali on the east- ern continent. The horns of the male are of immense size. They arise immediately above the eyes, and occupy nearly the whole head, they being only separated from each otljt;r l)y a space of throe-fourths of an inch at the base. They Ibrm a regular curve, lirst backwards, then downwards and outward— the extremities being eighteen inches apart. They are liattencd on the sides and deeply corrugated, the horns rising immedi- ately behind. The ears, are short and oval, clothed with hair on both surfaces. The general form of the animal is rather elegant, resembling the stag more than the Sheep. The tail is short. The hair bears no resemblance to wool, but is similar to that of the American Elk and Reindeer. It is coarse, but soft to the touch, and slightly crimped throughout its whole length ; the hairs on the back are about two inches in length, those on the sides one and a half inches. At the roots of these hairs, especially about the shoulders and .sides of the nock, a small quantity of short soft fur is per- ceptible. The legs are covered with short compact hairs. The female Rocky Mountain Sheep resembles some of the finest spe- cimens of the common Ram. Its neck is a little longer, as are also the head and legs, and in consequence it stands much higher. Its horns ROCKY MOUNTAIN SHEEP. 16.! resemble more those of the goat than of the Sheep, in fact, whilpt the fino erect body of the male reminds us of a large deer with the head of a ram, the female looks like a fine specimen of tlie antelope. The horns bend backwards and a little outwards, and are corrugated from the roots to near the points. Tail very short and pointed, covered with short hairs. Mamma; tivo ventral. COLOUR. The whole upper surface of the body, outer surface of the thighs, legs, sides and under the throat, light greyish brown, forehead and ears .X little lighter. Rump, under the belly and inner siu-face of liiiid legs, greyish white ; the front legs, instead of being darker on the outside and lighter on the insiJe, are darker in front, the dark extending round to the inside of the legs, and cn'ering nearly a third of the inner sur- lace. Tail and hoofs black. A i.'tvrow dorsal line from the neck to near the rump, conspicuous in the male, but comparatively (juite ob- scure in the female. Richardson stt.tes that the old male > are almost totally white in spring. DIMENSIONS. Male figure in our plate. Length Height at shoulder .... Length of tail Girth of body behind the shoulders Height to rump ..... Length of horn around ilie curve Do. of eye Weight 344 lbs. including horns. Female figure in our plate. jNose to root of tail .... lail • . . • . . • Height of rump . . . . Girth back of shoulders Horns — 44^ lbs. (Killed July 3d, 1843.) Ft. Ir^.h?8. 6 3 .5 5 3 11 3 lOf 2 lOi • • If 4 7 a 3 4* 3 # Weiglit 240 lbs. HABITS. It was on the 12th of June, IS 13, that we first saw this remarkable animal ; we were near the confluence of the Yellow Stone river with i' i I ■ ■" 1 1 ! 1 m^ V Ti 1 106 ROCKY MOUNTAIN SHEEP. I the Missouri, when a group of them, numbering twenty-two in all, came in siglit. This flock was composed of rams and ewes, with only one young one or lamb among them. Tliey scampered up and down the hills much in the manner of common sheep, but notwithstanding all our anxious efforts to get within gun-shot, we were unal)lo to do so, and were oblijrcd to content ourselves with this first sight of the Rocky Mountain Ram. The parts of the country usually chosen by these animals for their pastures, are the most extraordinary broken and precipitous clay hills or stony eminences that exist in the wild regions belonging to the Rocky Mountain chain. They never resort to the low lands or plains except when about to remove their quarters, or swim across rivers, which they do well and tolerably fast. Perhaps some idea of the country they inhabit (which is called by the French Canadians and hunters, "mauvaise terres") may be formed by imagining some hun- dreds of loaves of sugar of different sizes, irregularly broken and trun- cated at top, placed somewhat apart, and magnifying them into hills of considerable size. Over those hills and ravines the Rocky Moun- tain Sheep bound up and down among the sugar loaf shaped peaks, and you may estimaie the difficulty of approaching them, and con- ceive the great activity and sure-footedness of this species, which, together with their extreme wildness and keen sense of smell, enable them to baffle the most vigorous and agile hunter. They form paths around these irregular clay cones that are at times from six to eight hundred feet high, and in some situations are even fifteen hundred feet or more above the adjacent prairies, and along these they run at full speed, while to the eye of the spectator below, these tracks do not appear to be more than a few inches wide, although they are generally from a foot to eighteen inches in breadth. In many places columns or piles of clay, or hardened earth, are to be seen eight or ten feei. abc • the adjacent surface, covered or coped with a slaty flat rock, thus resernbling gigantic toad stools, and upon these singular places the big horns are frequently seen, gazing at the hunter who is winding about far below, looking like so many statues on their elevated pedestals. One cannot imagine how these animals reach these curious places, es- pecially with their young along with them, which are sometimes brought forth on these inaccessible points, beyond the reach of their greatest enemies, the wolves, which prey upon them whenever they stray into the plains below. The " mauvaise terres" are mostly formed of greyish white clay, very sparsely covered with small parches of thin grass, on which the Rocky Mountain Sheep feed. In vet weather it is almost impossible for any ROCKY MOUNTAIN SHEEP. 16t man to climb up one of these extraordinary conical hills, as they are slip- pery, greasy and treacherous. Often when a big horn is seen on the top of a hill, the hunter has to ramble round three or four miles before he can reach a position within gun-shot of the game, and if perceived by the animal, it is useless for him to pursue him any further that day. The tops of some of the hills in the "mauvaise terres" are composed of a conglom.M-ated mass of stones, sand, clay and various coloured earths, frequently of the appearance and colour of bricks. We also observed in tliese masses a quantity of pumice stone, and these hills, wc are inclined to think are the result of volcanic action. Their bases ol'ten cover an area of twenty acres; there are regular horizontal strata running across the whole chain of these hills, composed of different coloured clay, coal and earth, more or less impregnated with salt and other minerals, and occasionally intermixed with lava, sulphur, oxide and sulphate of iron; and in the sandy parts at the top of the highest hills, we found shells, but so soft and crumbling as to fall to pieces when we attempted to pick them out. We found in the " mauvaise terres, " also, globular shaped masses of heavy stone and pieces of petrified wood, from frag- ments two or three inches wide, to stumps of three or four feet. thick, apparently cotton wood and cedar. On the sides of some of the hills at various heights, are shelf-like ledges or rock projecting from the surface in a level direction, from two to six and even ten feet, gene- rally square or flat. These ledges are much resorted to by the big horns dur- ing the heat of the day. Between these hills there is sometimes a growth of stunted cedar trees, underneath which there is a fine sweet grass, and on the summits in some cases a short dry wiry grass is found, and quanti- ties of that pest of the Upper Missouri country, the flat-broad-leaved Cac- tus, the spines of which often lame the hunter. Occasionally the hills in the "mauvaise terre> " are separated by numerous ravines, often not more than ten or fifteen feet wide, but sometimes from ten to fifty feet deep, and now and then the hunter comes to the brink of oiie so deep and wide as to make his head giddy as he looks down into the abyss below. The edges of the caSons (as these sort of channels are called in Mexico) are overgrown with bushes, wild cherries, &c., and here and there the Bison will manage to cut paths to cross them, descending in an oblique and zig- zag direction ; these paths however are rarely found except where the ra- vine is of great length, and in general the only mode of crossing the ravine IS to go along the margin of it until you come to the head, which is gen- erally at the base of some hill, and thus get round. These ravines exist between nearly every two neighbouring hills, al though there are occasionally places where three or more hills form only one " Iffpf 1 ! i 1 t n ti I! |i 168 ROCKV MOUNTAIN SHEEP. All of them houevor rui, to ,m-vt .-ud. ol Iut and cmnect -.vith the hu-est the Size ol which bears its proporliou to that ofjts trihutarie.s a.ul .h,.i,- „u,nl,er ..here these ravines have no outlet into a sprinjj or water course ,hev have subterranean drains, and in some of the valleys and even on the toj.s of the hdls, tla.re are cavities called "sinkholes;" the earth near thes. holes .s oceus.onally undermined by the water running, round in circles un- derneath, leavin^^ a erust insullicient to bear the wei,^ht of a man, and when an unfortunate hunter treads on the dec-itful s.u-face it gives way and he finds himself in an unpleasant and at times dangerous predican.ent.' Ihese holes sometimes gradually enlarge and run into ravines below them t IS almost imi.ossible to traverse the "mauvarse terres" with a horse, un- less with great care, and with a thorough knowledge of the country The chase or hunt after the big horn, owing to the character of the country (as we have described it,) is attended with much danger, as the least 'slip imght precipitate one headlong into the ravine below, the sides of the hills being destitute of every thing to hold on by excepting a projecting stone or tult ol worm wood, scattered here and there, without which even the most daring hunter could not ascend them. In some cases the water has washea out caves of different shapes and sizes, some ol which present the most fantastic forms and are naked and barren to a great degree. The water that is found in the springs in these broken lands is mostly impregnated with salts, sulphur, magnesia, &c • but unpleasant as it tastes, it is frequently the only beverage for the hunter and luckily is often almost as cold as ice, which renders it less disagree' able. In general this water has the eiiect very soon of a cathartic and emetic. Venomous snakes of various kinds inhabit the "mauvaise terres" but we saw only one coj)pcr-head. ' Conceiving that a more particular account of these countries may be interesting, we will here insert a notice of them given to us by Mr • Dewey, the principal clerk at Fort Union. He begins as follows : "This curious country is situated, or rather begins half way up White river, and runs from south east to north west for about sixty miles in length, and varying from fifteen to forty miles in width. It touches the- head of the Teton river and branches of Chicune, and joins tlie Black Hills at the south fork of the latter river. The hills are in some places five or SIX hundred yards high and upwards. They are composed of clay of va nous colours, arranged in layers or strata running nearly horiz'ontallv each layer being of a different colour, white, red, blue, green, black yellow, and almost every other colour, appearing at exactly the same height on every hill. "From the quantity of pumice stone and melted ores found throughout ROCKY MOUNTAIN 9 HEEP. 169 them, one nught suppose that they had been reduced to this state by vol- canic actK,n. From the head of the Teton river, to cro^s these hills to White r. ver is about fifteen miles ; there is but one place to descend, and the road 1 "I r? I ',°"'^ "^^^ *" P'^'"''' '^ *° SO round the erl of them on the banks of the White river, and following that stream ascend to the de- sired pomt. In four day', march a man will make about fifteen miles io crossing through the "mauvaise terres." At first sight these hills look like some ancient city in ruins, and but little imagination is necessary to give tliem the appearance of castles, walls, towers, steeples, &c. The descent is by a road about five feet broad, winding around and among the hills, made at first probably by the bisons and the big horn sheep, and now rendered practicable by the Indiansandothers who have occasion to use it. It is however too steep to travel dow. with a loaded horse or mule, say about one foot in three, for a mile or so, after which the bases of the hills are about level with each other, but the valleys between them are cut up by great ravines in almost every direction from five to twenty and even fifty feet deep." *'In going over this part of the country great precaution is necessary, for ' a slip of the foot would precipitate either man or horse into the gulf below. When I descended, the interpreter, B. Daumine, a half breed, (having his eyes bandaged) was led by the hand of an Indian." Something like cop- peras in taste and appearance is found in large quantities, as well as pumice stone, every where. This country is the principal residence of the big horn sheep, the panther and grizzly bear ; big horns especially are numerous, being in bands of from twenty to thirty, and are frequently seen at the tops of the highest peaks, completely inaccessible to any other animal. There is but one step from the prairie to the barren clay, and this step marks the difference for nearly its whole length. These "mauvaise terres" have no connexion or affinity to the surrounding country, but are, as it were, set apart for the habitation of the big horns and bears. The sight ot this barren country causes one to think that thousands of square miles of earth have been carried off, and nothing left behind but the ruins of what was once a beautiful range of mountains. The principal part of these hills is white clay, which when wet is soft and adhesive, but the coloured strata are quite hard and are never discoloured by the rain, at least not to any extent, for after a hard rain the streams of water are of a pure milk white colour, untinged by any other, and so thick that ten gallons when settled will only yield about two gallons of pure limpid water, which, how- ever, although clear when allowed to stand awhile, is scarcely drinkable being salt and sulphurous iu taste. The sediment has all the appearance' of the clay already mentioned, which is nearly as white as chalk. There VOL. u. — 22. Ml ' t ! w 170 llOCKV MOUNTAIN SHJBEP. is only one place where wood mid pure; swetst water can be found in the whole range, which in at a spring nearly in the centre of the tract, and one day's journey from the White river, towards theChicune. This apjiears a little singular, lor if it were not lor this the voyageur would be obliged to take a circuitous route of from four to live days. This spring is surrounded by a grove of ash trees, about two hundred yards in circumference. It innnediateiy loses itself in the clay at the edge of the timber, and near the spring the road descends al)out sixty feet and runs through a sort of avenue at least half a mile wide, on each side of which are walls of clay extending horizontally about lifteen miles, and eiglity feet high, for nearly the whole distance. Between these walls are small sugar-loaf slia|)ed hills, and deep ravines, such as I have already described. The colours of the strata are preserved throughout. The principal volcano is the -'Cdle de tomierre," from the mouth of which smoke and fire are seen to issue nearly at all times. In the neighbourhood and all around, an immense quan- tity of pumice stone is dej)osited, and from the noises to be heard, no doubt whatever exists that eruptions may Irom time to time be expected. There is another smaller hill which I saw giving forth heated vapours and smoke, but in generE.; if the weather is clear the summits of the Black hills are obscured by a mist, from which circumstance many superstitions of the Indians have a isen. The highest of the Black hills are fully as high aa the Alleghany mountains, and their remarkable shapes and singular cha- racters deserve the attention of our geologists, especially as it is chiefly among these hills that fossil petrefactions are abundantly met with. The Rocky Mountain Sheep are gregarious, and the males fight fiercely with each other in the manner of common rams. Their horns are exceed- ingly heavy and strong, and some that we have seen have a battered ap- pearance, showing that the animal to which they belonged must have but- ted against rocks or trees, or probably had fallen from some elevation on to the stony surface below. We have heard it said that the Rocky Mouu- tain Sheep descend the steepest hills head foremost, and they may thus come in contact with projecting rocks, or fall from a height on their enor- mous horns. As is the case with some animals of the deer tribe, the young rams of this species and the females herd together during the winter and spring, while the old rams form separate flocks, except during the rutting season in December. In the months of June and July the ewes bring forth, usually one, and occasionally, but rarely, two. Dr. Richardson, on the authority of Drummond, states that in the retired parts of the mountains where the hunters had seldom penetrated, he 1 ROCKY MOUNTAIN SHEEP. 171 (Drijmmonu) found no diflieulty in approaching the Ilocky Mountain Sheep, which there exhibited the simplicity of character so rernarkal)le in the domestic species ; but tliat where they had been often fired at, they were exceedingly wild, alarmed their companions on the approach of danger by a hissing noise, and scaled the rocks with a speed and agility that baffled pursuit. He lost several that he had mortally wounded, by their retir- ing to die among the secluded precipices." They are, we are farther in- formed on the authority of Drummond, in the habit of paying daily visits to oeitain caves in the mountains that are encrusted with saline efflorescence. Tlie same gentleman mentions that the horns of the old rams attain a size so enormous, and curve so much forwards and downwards, that they efiectually prevent the animal from feeding on the level ground. All our travellers who have tasted the flesh of the llccky Mountain Sheep, represent it as very delicious when in season, superior to that of an_, species of deer in the west, and even exceeding in flavour the finest mutton. We have often been surprised that no living specimen of this very in teresting animal has ever been carried to Europe, or any of our Atlantic cities, where it would be an object of great interest. OEOGRAnilCAL DISTRIBUTION. This animal is found, according to travellers, as far to the North as lat 08, and inhabits the whole chain of the Rocky Mountains on their highest peaks down to California. It does not exist at Hudson's Bay, nor has it been found to the eastward of the Rocky Mountain chain GENERAL REMARKS. The hif?tory of the early discovery of this species, of specimens transmitted to Europe from time to time, obtained in latitudes widely removed from each other, of its designation under various names, and of the figures, some of which were very unnatural, that have been given of it, are not only in- teresting but full of perplexity. It appears to have been known to Father PicoLO, the first Catholic missionary to California, as early as 1697, who represents it as large as a calf of one or two years old; its head much like that of a stag, and its horns, which are very large, are like those of a ram ; its tail and hair are speckled and shorter than a stag's, but its hoof is large, round, and cleft as an ox's. I have eaten of these i)easts ; their flesh^is very tender and delicious." The Californian Sheep is also mentioned by Hernandez, Ci,avi,jero, and other writers on California. Vanegas has given an imperfect figure of it, which was for a long time regarded as the *. ' 172 ROCKY MOUNTAIN SHEEP. Siberian Argali. Mr. David Doiiolass, m thn Zoological Journal, in Ap.il, 1820, describes a sprcics un'Ier the name of (hi^ Calif ornica, which he' supposed to be the sheep mentioned by Picoi.o. Cook, in liis thin! voyage evidently obtained the si<in of the RocUy Mcimtain .Sheip on tiie north west coast of America. Mr. McISii.mverv, in IHJ.'J. presented to the New-Yorit Museum a specimen of this animal, and pul)lished an account of it in the Medical Repository of New- York. This specimen being after- wards sent to France, a description and figure of it were published. Lkwih and Clark, some years afterwards, brought male and female specimens to Philadelphia, which were figured by Griffith and Godman. Several eminent naturalists, and among the rest Baron Cuvier, consider- ed it the same as Ovis Ammon, supposing it to have crossed liehring's Straits on the ice. We have never had an opportunity of comparing the two spe- ciec, but have examined ther- separately. Our animal is considerably (he largest, ar' differs widely in the curvature of its horns from those of the oastern continent. We ha no doubt of its being a distinct species from Ovis Ammon. We doubt moreover, whether Ovis Californim will be found distinct from Ovis Montana ; the climate in those elevated regions is every whe/e cold There are no intermediate spaces where the northern species ceases to exist, p,nd the southern to commerce, and when we take into consideration the variations of colour in different individuals, as also in the same indi- vidual in summer and winter, we should pause before we admit O'jis Cat- i/oniica as a true species. We have therefore added this nrme as a synonyme of Ovis Montana. -'I 178 SCALOFfi r!ii:WKRI.- Bach. Brkwkr'h Skrew Mole. PLATE LXXIV, S. lanugiiie serioea, vellusobicmo cinortio nigricans subtu.s fuscesoene, piilma3 anguste, cui'da dcprcjsa, latiis pili.« hirsuta. CHARACTERS. Glossy cinereous black above, brbwimh beneath, palms nnrroW, Inil flat, broad and hairy. DESCRIPTION. Teeth, Incisive-; fahc mulars ^~; true molas "■ ^. 4.\. Tho head of Scahps Brcweri is narrower and more olonRatod than that, of .:?c. Aqnalicus. The cerebral portion of the wkuli is less voluminous, thp inter-orbital portion is narrower, each of the intermaxillary bonos in .Sv. Af/uaticus throws out a process, which projects upwards and forms the upper boundary of the nasal cavity, and very slightly separated by the na;«i! bonos, whilst in Sc. Brcweri these processes are shorter and scarcely project upwards above the plane of tho nasal bone. Thus when we view the snout of Sc. Aquaticus, laterally, it is distinctly recurved at the tip, whereas in Sc. Breweri the upper surface is almost plain. But the most striking differe.,ce between these skulls is exhibited in the dentition, inas- much as, m our present species, there are altogether forty four teeth in Sc. Aquaticus there are but thirty-six. Thus in the number of teeth Sc Breweri resembles Sc. Townsendi. The body of Brewer's Shrew Mole is perhaps a little larger than that of Sc Aquaticus. Its snout is less flattened a,nd narrower ; its .lostrils, instead of bei..g inserted in a kind of boutir, as in the European Tnlpa. and the swme, or on the upper surface of the muzzle, as in the common sh. »w mole, are placed on each side, uoar the extremities of the nose. This species IS pentadactylous, like all the rest of the genus, claws longer thin- ner and sharper than the common shrew mole. Palm much narrower Its most striking peculiarity, however, is its tail, which, inste'-.d of being round 174 BREWER'S SHREW MOLE. and nearly naked, like that of Sc. Aquaticus, is flat a..d broad, resembling ir some respects that of the Beaver, and is very thickly clothed, above and beneath, with long stiff hairs, which extend five lines beyond the vertebrtE. COLOUR. The colour, above and beneath, is a glossy cinereous black, like ve'vet • precisely similar to that of the European mole (r«//« Europea) with which we compared it. Under the throat there is a slight tinge of brown the tail is ashy brown above, light beneath. The ewe is about one. third longer than that of the common shrew mole. DIMENSIONS. IVOBISi 1 1 Lima. II 5 4 4 7 Length of the head and body Tail vertebrjB Do. including fur Breadth of tail Do. of palm . . . Length of do to end of middle claw In the Museum of the Zoological Society of London there is a specimen obtained from the United States, which evidently is the same specie^ It IS marked in the printed catalogue No. 145, "&. Breweri Bachman's M. SS It however differs in having the fur more compact, and shorter the colour somewhat darker, and in fact almost black. The hairs of the tail, instead of being brownish ash colour, are black, and the hind leet instea(' of being covered above with brownish white hairs, as in our specimens, are brownish black. DIMENSIONS OP THE SKULL OP THE ABOVE THREE SPECIES. Sc, Aqunticus S. Toionsendi S. Breweri LENOTS OF SKDLLS, IKOBM. llNi,. 1 4 3 1 1 WIDTH. LCNOTI' Of PII.ATI. LINKS. LINM. 8 7 0* 8| n 04 HABITS. m a collection of the smaller rodentia procured for us in New England byourfViendT„OM.sM. Brewer, Es,. an i.tcHigent naturalirwe t surprused and gratihed at finding this new species of shrew mole ; the spe^ cimen having been obtained by Dr. L. M. Yale, at Martha's Vineyard ^n ■sland on the coast of New Englan.l. In its habits it approaches much BREWERS SnilEW MOLE. 176 noarer the star-nosed mole {Condylura cristata) than any species of shrew mole. Its burrows are neither as extensive or so near the surface of the earth as those of the common shrew mole. We observed that the meadows in the valleys of Virginia, where this species is found, seldom exhibited any traces of their galleries, which are so conspicuous where the common spe- cies exists. We only possessed one opportunity of seeing this species alive. It ran across the public road near the red sulphur springs in Virginia ; in its mode of progression it reminded us of the hurried, irregular and awkward manners of the common shrew mole. It had, as we ascertained, pursued its course underground, at about five inches from the surface, until t reached the trodden and firm gravelly road, which it attempted to cnss and was captured. It evidenced no disposition to bite. From the fact of our having seen three specimens, which were accidentally procured in a /.^ek, we were led to suppose that it was quite common in that vicinity. We have not found its nest, and regret that we have nothing farther to add in regard to its habits. I.l OEOORAPinCAL ri87HIBUTI0N Our first specimen, as we have stated, was received from Martha's Vine- yard. Our friend, the late Dr. WRronx, procured four specimens m the vi- cmity of Troy, N. Y. We obtained specimens in Western Virginia. It no doubt exists in all the intermediate country. GENERAL REMARKS. We suspect that this species has hitherto been overlooked in consequence of its having been blended with the common shrew mole. We observed two specimens in the museum of the Zoological Society, London origi- nally marked ^^Talpa Europea from America." On examining the^ however, we found them of this species i ! I: 176 SOEEX CAROLINENSIS.— Bach. Cakolina Shrew. Maleb and Fkmales. PLATE LXXV. S. carolinensis, corpore griseo — cinerascente ; cauda brevis, depres.sti. characters. Carolina Shrew, toith a short flat tail; ears not visible; body of a nearly uniform iron grey colour. DESCRIPTION. Intermediary incisors Lateral tncisors ^; Molars, — = 34, »- .» 3 — 3 The four front teeth are yellowish white, with their points deeply tinged with chesnut brown ; all the rest are brown, a little lighternear the sockets. The upper intermediary incisors have each, as is the case in most other species of this genus, an obtuse lobe, which gives them the appearance of having a small tooth growing out from near the roots. The three late- ral incisors are largest; the posterior ones very small ; the first and fifth grinders are the smallest ; the jihor three nearly equal. In the lower jaw tlie two first teeth are lobed ; the lateral incisors are comparatively large and crowded near the grinders. The molars are bristled with sharp points except the last, which is a tuberculous tooth. The muzzle is moderately long and slender, and pointed with a naked deep lobed lip. The whiskers are composed of hairs apparently all white, a lew of those situated in front of the eyes extending to the occiput, the rest ratlicr short. There are no visible ears, even where the fur is removed ; the auditory opening is an orifice situated far back on the sides of the head running obliquely. The orifice of the eye is so small that it can only be discovered by the aid of a good magnifying glass. The tail is flat, thickly covered with a coat of close hair, and terminated by a small pencil of hairs. The lore ieet are rather broad for this genus, measuring a line and a half in breadth, rcf^embling in some respects those of the shrew mole {Sculops canadensis.) The toes are five, the inner a lirile shorter than the' fc v !'-r .ill i ill ^^'\ROLI^A stminv. 1 outer one ; the third and fourth nearly equal. The nails are sharp, rather lonsr, a little arohed, but not hooked. The hind feet are more slender than the fore ones ; naked beneath, and covered above, as are also the fore feet, by a thin coat ofshort adpressed hairs. COLOUR. The fur presents the beautiful velvety appearance common lo most species of this p^enus. The colour of the whole body is neni uniform, considerably lustrous on the upper surface, and in most li-hfs dark iron gray, rather darker about the head ; on the under surface the f.,r is of nearly the same general appearance, but is a shade lighter. niMENSIOVS. T.ensrth of body " of tail . . . . " of head .... of palm to the end of nails " of hind feet ■Nrniis. ft 1 HABITS. It is difficult to know much of the habits of the little quadrupeds com- posinj? this genus. Livin? beneath the surface of the earth, feeding princi- pally on worms and the larvfc of insects, shunning the liirht, and restricted to a little world of their own, best suited to their hnbits and enjoyments, they almost present a barrier to the pryins cijriosity of man. They are occasionally turned up by the plough on the plnntations of the south, when they utter a faint, squeaking cry, like young mice, nnd make awkward and scrambling attempts to escape, trying to conceal themselves in any tuO of grass,^ or under the first clod of earth that may present itself. On two occasions, their small but compact nests were brought to us. They were composed of fibres of roots nnd withered blades of various kinds of grasses They had been ploughed up from nbout a foot bencnth the surface of thf enrth. and contained in one nest five, and in the other six younjr. Tn diffging ditches, and plousrhing in moderately hieh grounds, smnll holes are frequently seen runnin? in all directions, in a line nearly pnrnllel with thesurfnce. nnd extendinsr to n srreat distance, evidentlv mnde bvthis spe- eies. We observed on the sides of one of the«e irnlleries. n smnll cavitv eontnining a honrd of coleopterous insects, principnlly composed of a rnre species (Sirnrahn'm ^Vvw.v). fully the size of the animnl itself : some of them u-cre nerirly eniiNUmfd. and the rest matila.fed. althousrh still living, vci,. n. — 23. ■! i 178 CAROUNA SHREW. OEOORAPIItCAL DISTRIBUTION. This quadruped is found in various localities, both in the upper and maritime districts of South Carolina. Wc recently received specimens from our friend Dr. Barhett. of Abbeville District ; and we have been informo.l by Dr. Pickkrino, to whose inspection we submitted a specimen, and who pronounced it undoubtedly an undescribed species, that it had been observed M far north as Philadelphia. i ■■ 1 179 CERVUS ALCES.~Lm«. , M008B Dbrr. PLATE LXXVI, Old Male tm Youko. C. magnitudine Equi ; capite permagno, labro aaribusqne elongatis ; coHo brevi, dense jubato, cornibus palmatis, cauda breyissima, vellere fusco cinereo, in nigrum vergente. CHARACTERS. Size of a horse. Head, very large ; snout and ears, long; neck, short, with a thick mane. Horns spreading into a broad palm. Tail, short Colour, hlackish-gray. SYN0NYME8. Elan, Stag, or Aptaptou. De Monts Nova Francia, p. 250. An. 1604. Eblan ou Orinal. Sagard-Theodat, Canada, p. 749. An. 1636. OiMNAL. La Ilontan, Voy., p. 72. An. 1708. MoowE Dkkr. Dudley, Phil. Trans, No. 368, p. 165. An. 1721. OniNAL. Charlevoix. Nouv. France. Vol. v., p. 185. An. 1741. " Dupratz, Louis. Vol. i., p. 301. M008K Dkkb. Pennant, Arct. Zool. Vol. i., p. 17, Fig. 1784. MooBK. Umfreville, Iluda. Bay. An. 1790. « Ilerriot's Travels, 1807, Fig. C. ALCKS. Harlan. Fauna, p. 229. " Godnian, Am. Nat. Hist., Vol. ii., p. 274. Thk Elk. Hamilton Smith. " Griffith's Cuv., Vol. v., p. 303. American Black Elk. Griffith's Cuv., Vol. iv., p. 72., plate of head. Elk. In Nova Scotia, proceedings of the Zoological Society, 1849, p. Oa. Cehvub ALCK8. De Kay, N. Hiat. N. Y., p. 115. I:! ! I DESCRIPTION. This is the largest of any known species of deer. Major Smith (Cm An. Kingdom, by Griffiths, Vol. iv., p. 73) says, "For us, who have the oppor- tunity of receiving the animal in all the glory of his full grown horns. 180 MOOSK UEliR. ,1 I , 1 :m amid tlin scener}- of his own wilderness, no aniuial could appear more majestic or m(/,e imposinj,'." Having ourselves on one occasion bet;!! I'avour- ed with a similaropporlunity, when we had the gralilicalion of bri'if^inj; one down wilh a riUe and of examining him in detail as he lay before us, we confess [w. ajipeared awkward in his g.-dt, clumsy and disproporfioned in limbs, uncouth and inelegant, in form, and possessing less synmu^try and beauty than anv other s])ecies of the deer family, llis great size, enormous liead, and face like a horse, and the thundering noise of the sa|)lings bending and sna|)ping around him as he rattled ov»t the fallen logs, was to us the only imposing part of the si)ectacle. To do justice, however, to the description of the moose, by Smith, who was a close observer and a naturalist of considerable attainments, we should quote his succeeding observations: "It is, however, the aggregate of his appear- ance whicii produces this elfect ; for when the proportions of its structure are considered in detail, they certainly will seem destitute ofthat harmony of parts whicli in the imagination produces the feeling of beauty." The head forcibly reminds us ofthat of an enormous jackass ; it is long narrow and clumsily shaped, by the swelling on the upper part of the nose and nostrils ; the snout is long aJid almost prehensile — the muzzle extending four inches beyond the lower lip. The nostrils are narrow and long, five inches in length. The eye is deep-seated, and in proportion to the large head is small. The ears are long, 14 inches, heavy and asinine. The neck is very short, and is surmounted by a compact mane of moderate length composed of coarse rigid hairs. There is in both sexes a -tufl; of coarse hairs, resembling hog's bristles, beneath the throat, which is attached to a pendulous gland, more conspicuous in young than in old animals; this gland with the attaclied hair is ten inches long. The horns, which are found only on the males, are, wlien a year old, merely short knobs; they increase in size after each annual shedding, and after the fourth year become palmated, and may be termed full grown about the (iflh year. The palms on the horns of the Moose are on the widest part on a moderate-sized male about 1 1 inches wide. The space between the roots, (>i inches; greatest breadth at the root, (5^ inches; from the root to llie extremitj', measuring around the curve, 2 lieet 10 inches. The first branch or prong on the inner side of the horn commences nine inches from the base It here divides into two branches, one being ten and the other eleven in- ches in lensrth, measuring in a curve from the root to the largest point 2.'> inches. These two prongs on each side incline forward, are almost round, and are pointed like those of elk horns. The palms on tlie iriain branches of <lie horns not only dill'er in dilferent individuals, but do not often cor- respond on the head of the same animal. In the specimen from which MOOSE DEER. 181 we are describing, the lower and longest point on the palm- is on one side la inches, and on the corresponding one on the opposite side only 4 inches; on the remainder of the palm there arc on one side six points, on the other seven ; the pjilin is about half-an-inch in breadth at the centre, thickening towards the base to one inch. The horns are irregularly and slightly channelled, and are covered with whitish marks on th(! irotit surface, somewhat resembling the channels and irregular windings of grubs or sawyers between the bark and wood in old decayed trunks of trees ; on the posterior suriace these; marks in form bear considerable resemblance to veina in the leaves of ferns. The width across the horns measuring irom the outer tips rises 3 feet 4 inches ; weight of the horns, 42 pounds. The nose, including the nostrils, is thickly clothed with short hair— a tri- angular spot on the nose bare. The hair on the mane is coarse and compact, 10 inches in length ; both surfaces of the ears are covered with dense hairs. The outer hair is throughout coarse and angular ; it is longer on the neck and should<!rs than on any other part of the body ; under these long hairs there is a shorter, woolly, more dense and finer coat. ii 1 4 m COLOUR. The teeth are white; horns brownish yellow, the extremities ot die prongs becoming yellowish white. The eyes are black ; nose, fore- head and upper lip, yellowish fawn ; inner surface of ears, yellowish white ; outer surface, grayish brown. .Sides of head, yellowish brown. On the neck, dark grayish brown, composed of hairs that are white, black and yel- low ; under the chin, yellowish brown. Hairs on the appendage under the throat, black ; lower lip and chi.., dark gray, formed of a mixture of white and black hairs ; the softer, shorter hairs on the body are ashy gray ; the long hairs when examined separately are whitish at the base, then cinere- ous and tipped with black, giving it a brownish black appearance. On the under surface of the body the colour is considerably lighter than on the back, having a tinge of yellowish white ; under surface of the tail, ashy white. The young animals, for the first winter, are of a reddish brown colour ; individuals even of the same age often differ in co- lour, some being darker than others, but there is always a striking diffe- rence between the summer and winter colours, the hairs in winter be- coming darker ; as the moose advances in age, the colour continues to deepen until it appears black ; thence it was named by Hamilton Smith not inappropriately as regards colour, " the American Black Elk " 18S MOOSE DEER, IWl. iDehcb (S IJ S H 4 1 2 1 10 DIMENSIONS. From point, of nose to root of tai), - . - Tail (vfi-trl)ru)), Tnil to end ol'liiiir, --.-.. From slioulder 111 point of hoof, - • llt>ij?ht of eiir, •---.. FVom point of nose to interior canthus of eye, - Weight of horns, 5(> pounds. Weight of the whole animal, from 800 to 1200 pounds. Dimensions of a Male procured in Ontario County, N. Y., in 1800. Feet. Inche«. Length from point of nose to root of tail, -••12 of tail, 11 Height at shoulder, ----... 5 00 Width of horns at tip, -•••-•28 Widest part, .-81 Weight of horns, 09 pounds. HABITS. We were favoured by Mr. Kkndau,, of the Literary Society of Quebec, with the following account of the Moose Deer, with which we will begin our article on this noble quadruped. " The Moose are abundant to the north of Quebec and in the northern parts of the state of Maine. In the neighbourhood of Moose River and thf lakes in its vicinity, they are very abundant. In the summer they are fond of frequenting lakes and rivers, not only to escape the attacks of in- sects which then molest them, but also to avoid injuring their antlers which during their growth are very sott and exquisitely sensitive, and besides, such situations atford theni abundance of food. •' They there feed on the water-plants, or browse upon the trees fringing the shores. In the winter they retire to the dry mountain ridges, and generally 'yard', as it is termed, on the side facing the south, where there are abundance of maple and other hard-wood trees upon which to feed, either by browsing on the tender twigs or peeling the bark from the stems of such as are only three or four inches in dinmeter. Their long, pendu- lous upper lip is admirably adapted for grasping and pulling down the branches, which are held between the fore legs until all the twigs are eaten. They peel oil' the bark by placing the hard pad on the roof of the MOOSE DKRR 188 mouth against the tree, and scraping upwards with their sharp, goiinrclikr teeth, c()ini)l(-l..ly denuding the tree to thn h.-ight of seven or eight feet from the surface of the snow. They reni.iin near tiie same spot as long as a«y food can l)e obtained, seldom breaking fresh snow, but keeping to the same tracks as long as possibh;. "The antlers begin to sprout in April, and at first appear like two blael knobs. They complete their growth in July, when the skin which coven them peels off and leaves them perfectly white ; exposure to the sun and air, however, soon renders them brown. When we consider the iiruncuiso size to which some of them grow in such a short period of time, it seems al- most incredible that two such enormous excrescences could be deposited from the circulating system alone; the daily growth is distinctly marked on the velvety covering by a light shade carried around them. The first year the antlers arc only about one inch long ; the second year four or five inches, with perhaps the rudiment of a point; the third year about nine inches, when each divides into a fork still round in form ; the fourth year they become palmated, with a brow antler and three or (bur points; the fifth season they have two crown antlers and perhaps five points j the points increasing in size each year, and one or two points J.eing addod animally, until the animal arrives at its greatest vigour : after which period they decrease in size and the points are not so fully thrown out. The longest pair I ever met with had eighteen points, (others have seen them with twenty-three points,) they expanded five feet nine inches to the outside of the tips; the breadth of palm, eleven inches without the points ; circumference of shaft, clear of the burr, nine inches ; weight, seventy pounds ! The old and vigorous animals invariably shed them in Decembers some of four and five jears old I have known to carry them as late as March, but this is not often the case. " The rutting season commences in September ; the males then become very furious, chasing away the younger and weaker ones. They run bel- lowing through the forest, and when two of equal strength meet, have dreadful conflicts, and do not separate until one or both are severely in- jured. I bought a pair of antlers from a Penobscot Indian, with one of the brow antlers and the adjoining prong broken short off. The parts were at least Ij inches in diameter, and nearly as hard as ivory. At that season they ure constantly on the move, swimming large lakes and crossing rivers in pursuit of the female. " The female brings forth in May. The first time she produces one fawn, but ever afterwards two. It is supposed by hunters that these twins are always one a male and the other a female. " In summer the hair of the Moose is short and glossy— in winter long and u' i' r 184 MOO?E DEER. ! I very coarse, attached to the skin by a very fine peliclo, and renderrti warn^ by a thick coat of short, iliie wool. The hiiir on the Inco ^'rovvs upwards from the nose, gradually turning and ending in a thick, bushy tuft under the jaws. The young males have generally a long, pendulous gland, growing Irom the centre of this tuft, and covered with long hnir, sometimes a foot h'Ug. " Their flesh is very coarse, though some people prefer it to any otlier it is apt to produce dysentery with persons unaccustomed to use it The nose or moitfle, as it is generally called, if properly cooked is a very delicious morsel. The tongue is also considered a delicacy ; the last entrail (called by hunters the bum-gut) is covered with round lumps of suely fat, which they strip off and devour as it comes warm from the animal, with- out any cooking. Also the marrow warm from the shanks is spread upon bread, and eaten as butter. I must confess that the disgusting luxury was rather too rich to tempt me to partake of it. I have seen some officers of th^ Guards enjoy it well enough ! " The seasons for hunting the Moose are March and September. In March, when the sun melts the snow on the surface and the nights are frosty, a crust is formed, which greatly impedes the animal's progress, as it has to lift its feet perpendicularly out of the snow or cut the skin from its shanks by coming in contact with the icy surface. "It would be useless to follow them when the snow is soft, as their great strength enables them to wade through it without any difficulty. If you wish to see them previous ;^ shooting them from their "yard," it is necessary to make your approach to leeward, as their sense of smelling and hearing is very acute: the crack of a breaking twig will start them, and they are seldom seen any more, until fatigue compels them to knock up, and thus ends the chase. Their pace is a long trot. It is neces- sary to have two or three small curs (the smaller the better), as they can run upon the snow without breaking through the crust ; their principal use is to annoy the Moose by barking and snapping at their heels, without taking hold. A large dog that would take hold would be instantly trampled to death. The males generally stop, if pressed, and fight with the dogs ; this enables the hunter to come up unobserved and dispatch them. Sometimes they are killed after a run of an hour, at other times you may run them all daj', and have to camp at night without a morsel of provisions or a cloak, as everything is let go the moment the Moose starts, and you are too much fatigued to retrace your steps to procure them. Your only resource is to make a huge fire, and comtbrt yourself upon the prospect of plenty of Moose-meat next day. As soon as the animal finds he is no longer pursued, he lies down, and the next morning MOOSE DEER. ISA he will l)e too stiff to travel far. Generally, a male, femule, and two lawns are found in a 'yard.' " When obliged to run, the male goes first, breaking the way, the others treading exactly in his tracks, so that you would think only one has passed. Often they run through other 'yards,' when all join together, still going in Indian file. Sometimes, when meeting with an obsta le they cannot overcome, they are obliged to branch off for some distance and again unite ; by connecting the different tracks at the place of separation you may judge pretty correctly of their number. I have seen twelve together, and killed seven of them. A method of hunting this animal is as follows : " In September, two persons in a bark canoe paddle by moonlight along the shore of the lake imitating the call of the male, which, jealous of the approach of a stranger, answers to the call and rushes down to the com- bat. The canoe is paddled by the man in the ster. with the most death- like silence, gliding along under the shade of the forest until within short shooting distance, as it is difficult to take a sure aim by moonlight ; the man in the bow generally fires, when if the animal is only wounded, he makes immediately fo- shore, dashing the water about him into foam; he is tracked by his blood the next day to where he has lain down, and where he is generally found unable to proceed any further. Many are killed in this manner in the neighbourhood of Moose River every season. Hunters sometimes find out the beaten tracks of the Moose (generally lead- ing to the water), and bend down a sapling and attach to it a strong hempen noose hanging across the path, while the tree is confined by another cord and a sort of trigger. Should the animal's head pass through the dangling snare, he generally makes a struggle which disengages the trigger, and the tree springing upward to its perpendicular, lifts the beast off his legs, and he is strangled !" Mr. John Martyn, of Quebec, favoured us with the following notes on the Moose deer : "This animal in the neighbourhood of this city (Quebec) is mostly found in the hard woods during the winter. At this season sev- eral associate together and Ibrm groups of two, three, or four, and make what is called ' a yard,' by beating down the snow ; and whilst in such places tliey feed on all the branches they can reach, and indeed even strip the trees c:^ their bark, after which they are forced to extend their 'yards,' or pel , (J -Tne ether place, but rather than leave the first, they will even b. jk ^w .ches as large as a man's thigh. In skinning off the bark, the animai piaces its upper lip firmly against it, whether upward, down- ward or sidewayd, and with its teeth, which are all on its lower jaw VOL. II. — 24. Irf 186 M(M)SK DEER. 9i tiikes a llim hold and tears it away in snips more or ess long n:\d broad, according to the nature of the bark of the tree. If is ascertained by the hunter whether a Mi>ose lias been lately or not in its yard, by removing the surface of the snow from around the foot of the trees already ' irked above, and if they have been barked belov the surface of the snow, the animal has left the spot lor sometime, and it is not worth while to follow any of its tracks. The contrary, of course, takes place wii'-i dif- ferent observations. At this season the female is generally accompanied by two of her calves, one two years old and generally a bull, the other the eaif ofthe preceding spring. These animals vary much in their colour, some being grayish brown, and others nearly bla 'k. The grayish Moose is generally ttie largest, often reaching the height of seven or eight feet. The females receive the males in the month of October, and at this period he latter are excessively vicious and dangerous when approached, whilst the females evince the same lierceness at the time of having calves. In some instances during the rutting season, when two males accidentally meet, they fight prodigiously hard, tearing up the earth beneath for yards around, and leaving marks of blood sufficient to prove that their encounter has been of the severest nature. Their usual mode of defence consists in striking at their enemies with their forefeet; but in fighting with each other the males use both feet and horns, and they have sometimes been killed with marks of old wounds about their head and other parts of the body. As an instance of the force with which the Moose strikes, the following an- ecdote may be related: a bull-terrier in attempting to seize one by he nose, was struck by the animal with its forefoot, and knocked olTto a dis- tance of twenty feet; the dog died next day. The Moose deer frequently turn against ilie hunters, even befon ' ing shot at or in the least wounded. They walk, trot, and gallop, and can kap a great distance at a single bound ; like other species of deer they bend their bodies verv liw rtt times, to pass beneath branches of fallen trees, not even half then b. ighi, from the earth. When pursued, they enter the most tangled tl r' i .ir pass ihrou^ii them as if not feeling the impediment.s the brushwood, lallen logs, &c., opposed to the huntcrV progress. The calves when born are about the size of a lew days old coit, but are more slender, and look very awkward on account of their apparent disproportionate long and iarge lege. When caught at three months old, they eat leaves, &c. ; but how long they are suckled by their dam we have not been able to ascertain. " During the summer they frequently resort to the shores of rivers, MOOSK DEER. jgi^ crBcks or lakes, on tliD mzirg.,is of which tlielr tracks are seen, like those of common cattle ; thpy enter thr water and immersn their bodies to save thriiisclvt's fniiii the hites of flies, &.c. In nil prohiilnliiy, where wolves are yet abundant, these are their most dangerous enemies besides man ; but at the present time, few of these rapacious animals are to be found in the neighbourhood of Quebec. The Moose deer are frequently killed while in the water, or on the shores of some pond, lake or river; but when their young are with them, they will run and chase the hunter, audit is sometimes difficult for him to escape, unless he is so fortunate as to shoot and bring them down. " The flesh is considered very good, especially the moitfflon, which forms the upper lip, and is very rich, juicy and livbitinous. Tins is cleaned and dressed in the same manner as ' calvps' iiead.' The hunters salt their meat for winter use. The steaks are as good as beef steaks ; but the Moose are not generally fat, although their flesh is juicy and at times tender. The joung at the age of twelve months are never toiigli. and their (lesli is prefer- able to that of the old beasts. The inside of the mouth above, or palate, is extremely hard, and lays in folds, giving this iinimal the powerof gripping ( seizing) the bark or the branches of trees, by which means it tears them off with ease. This pad is placed immediately beneath the extremity of the riKuifflon, and is about two inches long. " These animals feed principally on the birch, the moose-wood, the aspen, and various kinds of leaves and grasses ; in captivity they eat hay and other dry food, even hard ship-biscuit. The females are called • cows,' the males ' bulls,' and the young ' calves.' Their droppings resemble those of the deer kind. Although the Moose swim well they ar* not known to dive, they swim with the hend and part of the neck above water, like cattle. When pursued in boats they frequently attempt to upset them, and at times open their mouths and make a loud snorting noise, striking at the same time with their forefeet, and occasionally sink the canoes of the Indians or hun- ters. Upon one occasijn, a young man going fishing, and having his fowl- ing-piece along, on turning a point of a lake, saw a large Moose in the water and fired at it with shot, tickling it severely. The Moose at once made for the canoe ; and whilst the alarmed fisherman was attempting to escape, his boat became entangled in the branches of a fallen tree, when he was forced to give up the canoe and gf* away as he best could ; the animal on reaching the boat completely demolished it. Unfortunately, the females are sometimes killed when they are with calf. They do not gene- rally make any noise in the woods, unless when provoked, but in captivity they utter a plaintive sound, much resembling that made bv the black bear f I "i 188 MOOSE DEER. rl » They never are seen on the ice like the rein-deer ; it would seem by the formation of their hoofs that they might walk well on the rocks, or on the ice, but they keep in the woods, and when walking over snow their feet usually sink into it until they reach the earth. " A Mr. Bell, residing at Three Rivers, has a Moose which has been taught to draw water in a cart or in a sleig', during winter, but there is no possibility of working it during the rut»i g season. We have never heard of any attempt to ride on the Moose dei r. Their horns, which are large, palmated, and heavy, are dropped in the months of December and January, begin to show again in the latter part of March, and in two months or thereabouts attain their full size. When covered over with ' velvet,' as it is called, they are very curious. A pair of good Moose horns sells at the high price of twenty dollars ! The velvet is scraped off against trees and bushes in the manner employed by our Virginian deer. Horns have been measured when reversed and standing on the ground four feet seven inches, and ordinary pairs often measure five feet and up- wards. "It is said that the Moose can smell at a very great distance, and that the moment they scent a man or other enemy they make off and are not easily overtaken. On the first glimpse of man, if they are lying down they rise to their feet and are off at once, and often before they are observed by the hunter. When closely pursued, they turn and make a dash at the enemy, scarcely giving him time to escape, and the hunter's best plan in such cases is to keep cool a, 2 sV-oot the animal as it rushes towards him, or if unpre- pared, he had best ascend a tree with all convenient dispatch. Sometimes the hunter is obliged to save himself by dodging around a tree, or by throwing down some part of his dress, upon which the Moose expends his fury, trampling on it until torn to tatters. " Moose-hunting is followed by white or red skinned hunters in the same manner. He, however, who has been born in the woods, possesses many advantages over the 'civilized' man. The white hunters generally pro- vide themselves, previous to their starting, amply with provisions and ammunition to last them about three weeks, and sometimes go in a sleigh. The guns used are mostly single-barrelled, of ordinary size, but suited for shooting balls as well as shot,— rifles are rarely used in Canada. Afte: leaving the settlements, the first day's journey takes them ten or twelve miles, when they select a proper place in a snowy district, as near a stream as possible. " If the weather is fine, they cut down trees and make a camp, some of the party provide water, and others light the fires and clear off the snow for yards around, whilst evergret-.n trees are stripped of their branches tc J, MOOSE DEER. 189 make up a floor and covering for them in their temporary shelter. The hunters having made all snug, cook their meat and eat it before a fire that illuminates the woods around, and causes the party to appear like a set of goblins through the darkness of night. On muny such occasions the bedding is singed, and per chance a whisker ! The feet may be partially roasted, whilst the shoulders, the hands, and probably the nose, are suffer- ing greatly from the severity of the weather, for the thermometer may be occasionally thirty degrees below zero! The march to this spot is fre- quently made on snow-shoes, which are taken off, however, whilst the party are forming the encampment, clearing away the snow, and making a path to the water, which being covered with snow and ice, re- quires to be got at by means of shovels and axes. Before daylight, tk; kettles are put on the fires, tea and coffee are made, breakfast swallowed in a few moments, and the party on foot, ready to march toward the hunt- ing-ground. On the .y, every one anxiously looks out for tracks of the game, and whether hares or grouse come in the way they are shot and hung up on the trees; but if game of any kind has been thus hung up by others, whether Indians or white hunters, the party leaves it sacredly un- touched—for this is the etiquette of the chase throughout this portion of country. When they at last reach the ground, the party divide, and seek for the Moose in different directions. It is agreed that no one shall shoot after separating from the rest, unless it be at the proper game, and also that in case of meeting with Moose, or with fresh signs, they are. to return, and make ready to proceed to the spot together next day. Some- times, however, this rule is broken through by some one whose anxiety (excitement) at sight of a Moose makes him forget himself and his pro- mise. As soon as a 'yard' has been discovered, all hands sally forth, and the hunt is looked upon as fairly begun. If on approaching the ' yard,' their dogs, which are generally mongrels of all descriptions, start a Moose', the hunters, guided by their burking and the tracks of the pack and the Moose through the snow, follow with all possibi*; celerity. The dogs frequently fcake hold of the Moose by the hind legs, the animal turns, and stands at bay, aod the hunters thus have an opportunity to come up with the chase. "On approaching, when at the proper distance (about sixty to eighty yards) the nearest man takes a decided aim, .as nearly as possible under the forearm and through the neck, and fires, or, if fronting the beast, in the centre of the breast. " If wounded only, the second hunter fires also, and perhaps the third, and the animal succumbs at last, though it sometimes manages to run, stumble, .and scramble for miles. After skinning the j\Io<«e, i; hi I ^tu 190 MOOSE DEER. the heart and liver, and the mnrrow-bones, are taken out, and a good large piece of the flesh is taken to ' camp,' and is speedily well cooked and placed smoking hot before the hungry hunters. After killing alj the Moose of a 'yard' or that they can find near their camp, the party pack up :heir material, break up the camp, and return home. It not unfrequently happens, that a wounded Moose, or even one that has not been wounded, will turn upon the hunter, who then has to run for his life, and many instances of such incidents are related, including some hair-breadth escapes. One of these I will relate : Two Indians bei^g on a hunt and having met with the game, one of them shot, and missed; the Moose turned upon him, and he fled as (list as he could, but when about to reach a large tree, from behind which he could defy his opponent, his snow shoes hooked in some obstacle and threw him down. The Moose set upon him furiously and began trampling on him, but the Indian drew out a knife, and succeeded in cutting the sinews oC the forelegs of the animal, and finally stabbed him so repeatedly in the belly that he fell dead, but unluckily fell on the prostrate hunter, who would have been unable' to extricate himself, had not his companion come to his assistance. The poor man, however, had been so much injured that he never recovered en- tirely, and died about two years afterwards. During some seasons the snows are so deep, and at times so soft, that the Moose cannot go over the snow, but have to make their way through it, giving a great advantage to the hunters, who, on broad snow-shoes can stand or run on the surface without much difficulty. On one occasion of this nature a Moose was seen, and at once followed. The poor animal was compelled to plough the snow, as it were, and the hunters came up to it with ease, and actually placed their hands on its back. They then endeavoured to drive it towards their camp and secure it alive. The Moose, however, would not go in the proper direction, and they finally threw it down, and attempted to fasten its legs together; but as they had no ropes, and could not procure any better sub- stitute for them than withes, the beast got away, and after a long chase they, being very much fatigued, shot it dead. When the snow is thus soft, the Moose deer has been known to evade the hunters by pushing ahead through tangled thickets, more especially hachnctnck and briary places which no man can go through for any length of time; without extreme labour. The Indians, however, will follow the Moose in such cases day and night, provided the moon is shining, until the animal is so fatigued that it can be overtaken and killed with ease. Instances have been known where as many as i\\c have been killed in one day by two Indians. The Moose is not unfrequently caught in the following manner : A rope is passed over \ 3SE DEER. 191 a horizontal branch of a tree, with a large noose and slip-knot at one end, whilst a heavy log is attached to the other, hanging across the limb or branch, and touching the ground. The Moose, as it walks along, passes its head through the noose, and the farther it advances, the tighter it finds it- self fastened, and whilst it plunges terrified onwards, the log is raised from the ground until it reaches the branch, when it sticks, so that no mjitter in what manner the Moose moves, the log keeps a continued strain, rising and falling, but not giving the animal the least chance to escape, and at last the poor creature dies miserably. They are also ' pitted' at times, but their legs are so lor/, that this method of securing them seldom succeeds, as ihey generally manage to get out." The Moose is well known to travellers who have crossed the Rocky Mountains, where this animal is principally called by the French name, "L'Orinal." Whilst at Quebec, in 1842, ^"e procured the head and neck of a very large male, (handsomely mounted) ; whitih was shot in the state of Maine, where the Moose is still frequently found. Moose deer are abundant in Labrador, and even near the coast their tracks, or rather paths, may be seen, as distinctly marked as the eow-paths about a large stock-farm. In this sterile country, where the trees are so dwarfish that they only deserve the name of shrubs, and where innumerable barren hills arise, with cold clear-water ponds between, the Moose leeds luxuriously on the scanty herbage and the rank summer grasses that are found on their sides; but in winter the scene is awfullj desolate, after the snows have lallen to a great depth ; the whistling winds unimpeded by trees or forests, sweep over the country, carrying with them the li"ht snow from the tops and vi'indward sides of the hills in icy clouds, and soon forming tremendous drifts in the valleys. No man can face the storm- driven snows of this bleak, cold country ; the congealed particles are almost solid, and so sharp and fine that they strike upon the face or hands like small shot ; the tops of the hills are left quite bare and the straggling Moose or rein deer seek a precarious supply of mosses along their sides. At this season the Moose sometimes crosses the Gulf of St. Law- rence on the ice to Newfoundland, or follows t'he coast towards the shore opposite Nova Scotia, and there passes the Gulf and wanders into more woody and favoured regions for the winter. The following is from our friend S. W. Roiimav, Esq., of Boston, an excellent siioitsiuiin. and a lover of nature, to whom wo are indebted for many kindnesses. " O'lr party was rctmninsf from lake Miraniichi, aJioiit the midillo of'July, by the mai'sliy brook, wliieh couneets it with the Miianiiehi river. The canoe men were poling slowly and silently, in order not to disturb the numerous ducks which breed in those \ini P^.,l,:t(>(l soUtiulcs. as we woroanxiou-* to vary onroonstiint fish ,]\ I :almon ei ther boiled or " skinned" being set before us morning, noon and ■' I ■! i M 102 MOOSE DEER. night. Wc harl not fired ,i gun to disturb the siii'iico. My ofrn and my hrother's canoes were ch).se together, when I saw an animal suddenly spring on to its feet from the long marshy grass about forty yards in advance of us. I said quickly ' Caribou," " Cariboo," "stoop low ;" which wo all did and continued moving on. It was about the size of a yearling heifer, but taller, of a bright, light, red colour, with long cars pricked forward, and a large soft eye ; and stood perfectly still, looking it us. We had gone perhaps ten yards, when there apjjcared from the long grass i)y its side, first the ears, then the huge head and muffle of an old cow Moose, the first one being as I now knew her calf, of perhaps four or five months old. She gradually rose to her knees, then sat upon her haunches, and at last sprang to her feet, her eyes all the time intently fixed upon us. The calf in the meanwhile had moved slowly off. At this moment we both fired without any apparent effect, the shot ])eing too light to penetrate the thick hide. She turned instantly, showing a large and apparently well filled udder, struck into the tremendous trot, for which the Moose is so celebrated, crossed the deep brook almost at a stride, then the nar- row strip of meadow, and disappeared, crashing through the alders which inter, vened between the meadow and the dark evergreen forests beyond. Our oldest woodsman. Porter, assured us that she was one of the largest of her kind, and that it was rare good fortune to approach so near to this noblest denizen of our northern forests. We were much gratified, but our regret as sportsmen was still greater, at not having been prepared to take advantage of such an oppor- tunity as will probably never again occur to either of us. We constantly both bo fore and afterwards saw the tracks of cariboo and Moose about our camps." GEOGRAPHICAL DISTRIBUTION. Capt. Franklin, in his last expedition, states that several Moose were seen at the mouth of Mackenzie River, on the shores of the Arctic Sea. in latitude (JO**. Farther to the eastward towards the Copper-mine River, we are informed by Richardson, they are not found in a higlier latitude than 05". Mackenzie saw them high up on the eastern declivity of the Rocky Mountains, near the sources of the Elk River ; Lewis ami Clark saw tnem at the mouth of the Oregon. To the sast they abound in Labrador, Nova Scotia, New-Brunswick, and Lower Canada. In the United States they are found in very diminished number.s in the unsettled portions of Maine and at long intervals in New-Hampshire and Vermont. In the state ot New- York, according to the observations, made by Dr. Dekay, (Nat. Hist. N. Y., p. 117), which we believe strictly correct, they yet exist in Herkimer, Hamilton, Franklin, Lewis and Warren counties, and their southern limit along the Atlantic coast is 43' 30'. GENERAL REMARKS. We have considerable doubts whether our Moose deer is identical with the Siandinavian elk {Ccrvus olrrs, of authors), and have therefore not quoteJ any of the synonymes of the latter, but having possessed no favourable oppcn-tuiiitics of deciding this point, wc have not ventured on the tidoi)tion of any of the specific names which have from time to tiiiif been propotscd for i]:r Annr'cjtn Moose. 19» GENUS ANTILOCAPRA.-ORr. 1 DENTAL, FORMULA. Incisive - ; Canine — ; Molar — = 32 0-0 ' 6-6 Horns common to both sexes ; small in the female ; horns persistent, greatly compressed, rough, pearled, slightly striated, with an anterior process, and the point inclining backwards ; eye large ; no suborbital sinus ; no inguinal pores ; no muzzle ; facial line, converse ; no canines ; no succentorial hoofs ; tail very short ; hair stiff, coarse, undulating, flattened ; female, mammse. Habit, peaceable, gregarious, herbivorous, confined to North- America. Only one well determined species belongs to this genus. The generic name Antilocapra, is derived from the two geneva. AntUope and Capra, Goat Antelope. i t 1 : ANTILOCAPRA AMERICANA.—Obd. PRONG-HORNED AnTELOPE. PLATE L XXVI I. Male and Female. Cornibus pedalibus compressis, intus planis, antife granulatis striatisque propucnaculo compresso procurvo cum cornum parte posteriore retrorsum uncinata furcam constitutiente ; colore russo fuscescente, gutture, cluni- umque disco albis : statura, Cervus Virginianus. CHARACTERS. Horns compressea, flat on the inner side, pearled and striated, with a com. pressed snag t„ the front ; colour, reddish dun ; throat and disk on the hut- tocks, white. Size of t/ie Virginia deer. vol.. II. — 25 i i. i. >^'\' 194 PRONC-IIORNKfi ANTKLOPE. 8VNONYMES. Tecthlamacam.*;. Ilcniaiidoz, N()v.-Ilis|)aii, p. '.Vi4, Hfj. J524. An. 1(551, Lk SlJlJKNDTON. 1 list. (I'.\lurli(|llc, |). 175. All. \1'2',i. Siji'iNAToN. l)<il>lp's, lluilsiiii's ISav, |i. 'il. An. 1711. Antiloi'k, ('AiiiiK on <J(iAr. (iiiss tloiirniil,$$\i. 4U, 111.
Antii.opk. Lewis anil Clarko .loiiiii., N'oi. !., ]<\>. 75, "JOH, .'('.Mi; Vol. ii., p. KJO.
Anth.oi'k ;\mi;kk'ana. Old, (iiitliiif's (icofiiiiiili} . KSlft.
Ckuvus hamah's. Blainvillc, MouvlJiill. Socioty. ISlC.
Antii.oc'AI'ua Amkkicana. Ord, .lour, do I'livs., |). HO. 1818.
;\niii.<)1'k Fi'iu'iKKit. ('. Ilanultc n Smith, Lin. 'IVans., N'ol. xiii., jilati' 2. An. 1823
Antilopk i'ai.ma'ia. Sniitli, (jiillitli, ("iiv., Vol. v., p. ;i2.'!.
ANTii.orE Amkkicana. lla'Ian I'.uiiia. |i. "J'tO.
■" (lodnian, Nat. Hist., Vol. ii., p. ;}21
ANTiLorK FunciFKK. Kicliaidson, h\ ii. A,, d. 201, j)iatc 21.
DESCRII'TION.
Tlic Proiifr-liornrd Aiifelopo possesses a stately and clcj^ant ConTi. and
resenihios more the antelope lluin tlie deer family. It is slioiter and more
con-.paetly built tlian the Vir^jfinii deer ; its head and neek ai-e also shorter
and the skull is broader at th(\ base. The horns of the male are curved
upwards and baekwards with a short trianjriilar prony: about the centre,
ineliiied inwards, not wriidded. Immediately above the pron<? llie horn
diminishes to less than half the size, below the pronj;; the horn is flat and
very broad, extremity of the horn iiup and pointed, and of the prong
blunt. There are irrejrular little poie >n the horns of the male, two or
three on each side. One si)eeinien has tv.'o on the inside of each horn and
one on the outside irrejinlarly disposed.
Nostrils larpe and opr^i, ])hiced rather tar back, eyes large and promi-
nent, ears of moderate size, acuminate in .shape ; on the back of the neck in
winter specimens there is a narrow ridge of coar.se hairs resembling a sliort
mime. In summer there only remains of this mane a black stripe on the
upper surf ice of the neck; eyelashes profuse; there i.s no under-fur. 'J'lie
hairs are of a singular texture, being thick, soft, wavy and slightly crimped
beneath the surface : they are brittle, and when bent do not return to their
original straight form, interiorly they are white, spongy and pithy; scrotum
pendulous. There is not the slightest vestige of any secondary hoofs on
either of its fore or hind legs, such as are seen in deer and other animals. The
hoofs are strong and compact, small and diminishing suddenly to a point.
COLOUR.
The nose is yellowish brown, eye lashes black, the orl)ils with a blackish
brown border, outer edge and points of the ears brownish black. There i&
PRONO-IIORNEn ANTEIX:)PE.
195
a white briiid about two itichos widriti front of and partly oncirclin-,' the
throat, narrowing to a point on each side of the neck; Ix-ncath tliis is a
brown i)an(i about tlic samo breath, unchinmath wiiich is a grayish white
spot of nciirly a tri.iiii-iilar shape ; lliis is formed by a p.itdi on eaeii si(h; of
the throal of yellowish brown. The ela^sl, belly, and sides to within live
or six Inches of tiie back are t,'rayish white. A lar^'c light-eoloured patch
of nine indn-s in breadtii exists on the runip, similar to that on the Rocky
Mountain slieej) and the «"lk. This wliitish patch is separated l)y a brown-
yellowisli line, running along tlu; vertebra' of the back to the tail. Legs,
l)ale brownish yellow, approaching to dull buff colour, all the upper surface
yellowish brown ; under.jaw and cheek, pale or grayish white ; lips, whitish,
Fvinnlc. — The I'eniale is a size smaller than the male. The neck is
shorter. The form is similar, except that tin markings are rather faint<"r;
the brownish yellow which surrounds th(^ dillerent whitish or grayish
white spots and bands being nundi paler than in \\m male. The horn is
destitute of a prong; it is only three inches in length, nearly straight, and
running to an acute point. The female possesses no mane
DIMENSIONS.
From point of m)se to root of tail,
Height, to shoulder from end of hoof,
Length of ear, ....
Length of prong.
F»T. Incuri.
4 2
3 1
4
6
HAniTS.
Reader, let us carry you with us to the boundless plains over whicli the
pnmg-horn speeds. Hurra for the prairies and the swift antelopes, as
they (le(>t by the hunter like flashes or meteors, seen but for an instant, for
(luiekly do they pass out of sight in the undulaling groimd, covered wilh
t;ill rank grass. Observe now a flock of these beautiful animals; they
are not aliii id of man— they pause in their rapid course to gaze on the hun-
ter, and stand with head erect, their ears as well as eyes directed towards
him, and make a loud noise by stamping with their forefeet on the hard
earth ; but suddenly they btjcome aware that he is no friend of theirs, and
away they bound like a (lock of frightened sheep— but far more swiftly do
the gracefid antelopes gallop ofl", even the kids running with extraordinary
speed by the side of their parents — and now they turn around a steep hill
and disappear, then p(>rhaps again come in view, and once more stand and
gaze at the intruder. Sometimes, eager with curiosity and anxious to
; , I
196
PRONG-HORNED ANTELOPE.
I),f
examine the novel object wli ch astonislirs as well as alarmii them, (hi:
antelopes on seeing a hunter, advance toward him, stopping at intervals, and
then again advancing, and should the hunter partly conceal himself, and
wave his handkerchief or a white or red rag on the end of his ramrod, he
may draw the wondering animals (piite close to him and then (piickly seiz-
ing his ride send a hall (lirough the fattest of the group, ere the timiv' „jea.
tures have time to fly from the fatal spot.
The Indians, we were told, sometimes bring the antelope to within ar-
row-shot (bow-shot), by throwing themselves on their backs and kicking
up their heels with a bit of a rag fastened to them, on seeing which mov-
ing amid the grass the antelope draws near to satisfy his curiosity.
The atmosphere on the western prairies is so pure and clear that an an-
telope is easily seen whea fully one mile ofl', and you can tell whether it
is feeding quietly or is alarmed ; but beautiful as the transparent thin air
shews all distant objects, we have never found the great western prairies
equal \\\v floucry descriptions of travellers. They lack the pure streamlet
wherein the hunter may assuage his thirst— the delicious copses of dark,
leafy trees ; and even the thousands of fragrant flowers, which tln^y are poet-
icaliydescribedas possessing, aregenei-allyof the smaller varieties; and ihe
Indian who roams over them is far from the ideal being — all grace, strength
and nobleness, in his savage freedom— that we from these descriptions con-
ceive him. Reader, do not expect to find any of the vast prairies that
border the Upper Missouri, or the Yellow-Stone rivers, and extend to the
Salt Lakes amid the Califbrnian range of the Rocky Mountains, verdant
pastures ready for flocks and herds, and full of the soft perfume of the
violet. No ; you will find an immense waste of stony, gravelly, barren soil
stretched before you ; you will be tormented with thirst, half eaten up by
stinging flies, and lucky will you be if at night you find wood and water
enough to supply your tire and make your cup of coffee; and should you
meet a band of Indians, you will find them wrapi)ed in old buffalo robes,
their bodies filthy and covered with vermin, and by stealing or begging
they will obtain from you perhaps more than you can. spare from your
scanty store of necessaries, and armed with bows and arrows or firearms,
they are not unfrequently ready to murder, or at least rob you of all your
personal property, including your ammunition, gun and butcher knife!
The Prong-horned Antelope brings forth its young about the same time
as the common deer: from early in May to the middle of .Tune ; it has gen-
erally two fawns at a birth. We have heard of no case in which more
than that number has been dropped at a time, and probably in some cases
only one is fawned by the dam. The young are not spotted like thf fawn
of the common deer, but are of a uniform dun colour. The dam
PRONG-IIORNED ANTELOPE.
197
remains by her yxang for some days after they are born, feeding immedi-
ately around the spot, and afterwards Krarliially enlarjjinK lier range ; when
the young are a I'orfiiigiit old ihey have gained strength and speed enough
to escape with their llt'et-footed mother from wolves orotiier four-footed
foes. Sometimes, however, the wolves discover find attack the young
when they are too feeble to escape, and the mother then displays the
most devoted courage in their defence. She rushes on tliem, butting and
striking with her short horns, and sometimes tosses a wolf heels over head,
she also uses her forefeet, with which she deals severe blows, and if the
wolves are not in strong force, or desperate with iiunger, puts them to
flight, and then seeks with her young a safer pasturage, or some al-
most inaccessible rocky hill side.
The rutting season of this species commences in September, the bucks
run for about six weeks, and during this period fight with great courage
and even a degree of ferocity. When" a male sees another approacli-
ing, or accidentally comes upon one of his rivals, hofh parties run at each
other with their heads lowered and their eyes flashing angrily, and while
they strike with their horns they wheel and bound with prodigous activity
and rapidity, giving and receiving severe wounds,— sometimes like fencers,
getting within each others " points," and each hooking his antagonist with
the recurv(!d branches of his horns, which bend considerably inwards and
downwards.
The Prong-horned Antelope usually inhabits the low prairies adjoining
the covered woody bottoms during spring and autumn, but is also found on
the high or upland prairies, or amid broken hills, and is to be seen along
the margins of the rivers and streams : it swims very fast and well, and oc-
casionally a herd when startled may be seen crossing a river in straggling
files, but without disorder, and apparently with ease.
Sometimes a few of these animals, or even only one or two by them-
selves may be seen, whilst in other instances several hundreds are con-
gregated in a herd. They are remarkably shy, are possessed of a fine
sense of smell, and have large and beautiful eyes, which enable them to
scan the surface of the undulating prairie and detect the lurking Indian or
wolf, creep he ever so cautiously through the grasses, unless some inter-
vening elevation or copsewood conceal his approach. It is. therefore,
necessary for the hunter to keep well to kiicanl. and to use extraordinary
caution in "sneaking" after this species; and he must also exercise a
great deal of patience and move very slowly and only at intervals, when
the animals with heads to the ground or averted from him, are feeding or
attracted by some other object. When they discover a man thus stealthily
moving near them, at first sight thej fly from him with great speed, and
I i
li • M
|i
Ill
li
198
PRONG -HORNKF^ ANTE[,()ME.
often retire to i'.,s brokon
KioiiikLs of (he clay hills, from which
which they are
not oDcM tempfed to stray a -n-iit (lislaiicc at any (iitic. As we h.iv." ..ireiidy
mrntionrd. there are ine;ms, however, to ••x<'ite the timid anlelope to
draw near iIk- Imnler, l.y aroiisinfj; his eiiriosiiy nnd deeoyin;; liiii. lo his
ruin. 'I'he antelopes of ih.^ Tpper Missouri eounlry are Imjuenlly shot hy
the Indians whilst crossing; the river; and, as w.; were infortned, preCerreil
the nor'' m side of the Missouri ; whieli. no doubt, arises from the pr<'va-
•'•' . on that bank of the river of certain plants, trees or grasses, that Uiey
are most fond of. Males and females are found together at all seasons of
the year. We have been fold that probably a thousand or more of these
animals have been seen in a single herd or llocU at one time, in the spring.
It was supposed by the hunters at Fort Union, that the prong-horned
antelope dropped its horns; but as no person had ever shot or killed one
witliout thes(> ornamental and useful appendages, we managed to prove
the contrary to the men at the fort by knocking off the bony part of the
horn, and showing the hard, spongy membrane beneath, well attached to
the skull and perfectly inmioveable.
The Prong-horned Antelope is never found on the Missouri river below
i:,(in f/iii voiirt ; but above that stream they are found along the great
Missouri and its tributaries, in all the country east of the Rocky Moun-
tains, and in many of the great valleys that are to be met with among these
extraordinary " big hills." None of these antelopes are found on ihe shores
of the Mississippi, although on the headwaters of the Saint Peter's river
they have been tolerably abundant. Their walk is a slow and somewhat
pompous guit, their trot elegant and graceful, ;d their gallop or " run"
light and ii-conceivably swift ; they pass along, up or down hills, or along
the level plai.' with the same apparent ease, while so ra[)i(Jly do their legs
perform their graceful movements in projielling their bodies over the
ground, that like the spokes of a fast turning wheel we cixn hardly see
them, but instead, observe a gauzy or tilm-likc appearance where thev
should be visible.
In autumn, this species is fatter than at any other period. Their liver
is much prized as a delicacy, and we have heard that many of these ani-
mals are killed simply to procure this choice morsel. This antelope feeds
on the short grass of the prairies, on mosses, buds, &,c. ; and sutlers greatly
during the hard winters experienced in the north-west; especially when
the snow is several feet in depth. At such times they can be caught bv
hunters provided with snow shoes, and they are in this manner killed, even
ill sight of Fort Union, irom time to time.
It is exceedingly dillicult to rear the young of this species; and, although
many attempts have been made at Fort Union, and even an old one caught
I'llONG-llOKNKI) ANTKIiOl'K.
lyo
iind hiouK'lit within an enclosure to keep (be young eoinpany, ihey became
furious, (vnd nui uiid butted ultermitely iigiiin.st th(! picket-wall or fence,
until they were too inucb bruised and exhausted to recover William
BuuLK/rrK, Esij., of St. I^ouis, Missouri, however, brouj^ht with hiin lo that
cil/a leinale antelo|Ks caught when (|uite young on the prairies of the
far west, which grew to maturity, and was ho very gentle, that it would go
all over the house, mounting or descending the Btairs, and occasionally
going on to the roof of th ■ building he lived in. This female was aiive
when we lirst reached Nt. Louis, but ifot being aware of its existence, w<'
never saw it. It was killed belbrj we lell by •. )uck-elk, belonging to the
same gt^ntleman.
Whilst (m our Journey in the fai u, in 1813, on one occasion, we had
tli(! gratitieation of seeing an old female, in a h.,. '. of eight or ten antelopes,
suckling its young. The little beauty performed this operation pnscisely in
the manner of our common lambs, almost kneelir g down, bending its head
upwards, its rump elevated, it thumped the bag of its molher, from time
to tim<', and reminded us of far distant scenes, whciv peaceful flocks leed
and repos(! under the saleguard of our race, and no prowling wolf or hungry
Indian deleats the hopes of the good shepherd who nightly lolds his stock of
the Leicester or Bakewell breed. Our wild antelojjes, h vvever, as we
ap|)roached them, scampered away; and we were delighted to see that
(irst, and in the van of all, was the young one !
On the 21st July, 1813, whilst in company with our frirnc", Edward
Harris, Esq., during one of our hunting excursions, we came in sight of an
antelope gazing at us, and determined to stop and try if we could bring
him toward us by the trick we have already mentioned, of throwing our
legs up in the air and kicking them about, whilst lying on our back in the
grass. We kicked away (irst one foot and then the other, and sure enough,
the antelope walked slowly toward us, apparently with great caution and
or three hundred yards. He was a superb male, and we looked at him tor
several minutes when about sixty yards off. We could see his fine pro-
truding eyes ; and being loaded with buck-shot, we took aim and pulled
trigger. Off he went, as if pursued by a whole Black-foot Indian hunting
partj'. Friend Harris sent a ball at him, but was as unsuccessful as our-
selves, for he only ran the faster for several hundred yards, when ho
stojjped for a few minutes, looked again at us, and then went ofl, without
pausing as long as he was in sight. We have been informed by LArLKUR,
a man employed by the Company, that antelopes will escape with great
ease even when they have one limb broken, as they can run fast enough
upon three legs to dely any pursuit. Whilst we were encamped at the
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PRON(J.nOUNKI) ANTKIAPE.
" Thn*p Miimolli's," about sixty miles wrst ol' Fort I iiion, eixrly one inorning
im aiitelopti wiis lirunl .iiiurtiiig, and was sccti hy soiiu- ofoui |)arty for a
few iiiiiuitcN only. Tliis siiortiiiy;. us it is ciillcd, res, mblcs a loud whistlinju'
8in;L?in;Li; sound proioiifjcd, and is very dilii-rcnt I'roin tlic loud and clear
snorting ofoiir coinnion deer ; hut it has always appt'ared to us to he almost
useless to attempt to describe it ; and idtliou^,'h at this moment we have
the sound oi'the antelope's snort in oiirrdr.s, >ve feel quite ur de to give
its etjuivalent in words or syllahlps.
The antelope has no lachrymal pits under the eyes, as have deer and
elks, nor has it any gland on the hind leg, so curious a feature in many ol
those animals of the deer tribe which drop their horns aimually. and oidy
wanting (so far as our knowledge extends) in the Crnui.s liivlKinlsonii,
which we consider in eonse(ju<'nce as approacliing the genus AhIHojh; and
in a small deer from Yucatan and Mexico, of which we had a living
specimen for some time in our possession.
The ])roiig-hornrd antelope often dies on the open prairies during severe
winter weather, and the ri in.uns ofshockingly poor, st;irved, miserable indi-
viduals of this species, in a state of the utmost emaciation, are now and then
found dead in the winter, even near Fort Union and other trading posts.
The present species is caught in pens in the same manner nearly as the
bison, (which we have already descril)ed at p. 97) but is generally despatcn-
ed with clubs, principally by the women. In the winter of 184(1, when the
.snow was deep ir. ihe ravines, having drifted, Mr. I,\idlaw, who was
then at Fort Union, caught some of them by following them on horse-
back and forcing them into these drifts, which in places were as much as
ten to twelve feet deep. They were brought to the fort in a sleigh, and
let loose about the rooms ; they were to appearance so very gentle that
the people suffered their children to handle them, although the animals
were loose. They were placed in the carpenter's shop, one broke its
neck by leaping over a turning-Iatlie, and the rest all died ; for as soon as
they had appeased the cravings of hunger, they began to fret for their
accustomed liberty, and regained all their original wildncss. They leaped,
kicked and butted themselves against every obstacle,untiltoomuchexhaust-
ed to recover. — These individuals were all captured by placing nooses,
fixed on the end of long poles, round their necks, whilst they were embedded
in the soft and deep snow drifts, to which they had been driven liy Mr.
[jAmLAW
There are some peculiarities in tiie gait of this species that we have
not yet noticed. The moment they observe a man or other strange object
producing an alarm, they l)oniid olf lor some thirty or forty yards, raising
all their legs at the same time, and bouncing, at it were, from two to tiiree
PRONG-IIORNED ANTELOPE.
901
fePt above tho ground • nfter this they stretch their bodies out and gallop
at an extraordinary speed. Wo have seen some which, when started,
would move off and run a space oCseveral miles, in what we thought did
not exceed a greater number of minutes !
From what we have already said, it will be inferred that the wolf is
one of the most formidable enemies of this species. We have, however,
not yet mentioned that in some very cold and backward seasons the young,'
when first born at such times, are destroyed by these marauders in such
numbers that the hunters perceive the deficiency and call them scarce for
the next season. Antelopes are remarkably fond of saline water or salt,
and know well where the mlt-licks are found. They return to them daily]
if near their grazing grounds, and lay down by them, after licMng the'
salty earth or drinking the salt water. Here they will remain for hours
at a time, in fact until hunger drives them to seek in other places the
juicy and nourishing grasses of the prairie. This species is fond of taking
its stand, when alone, on some knoll, from which it can watch the move-
ments of all wanderers on the plains around, and from which a fair chance
to run in any direction is secured, although the object of its fear may be con-
cealed from view occasionally by a ravine, or by another projecting ridge
like its own point of sight.
We had in our employ a hunter on the Yello"- -Stone River, who killed
two female antelopes and broke the leg of a ..: rd at one shot from an
ordinary western rifle. The ball must have passed entirely through the
two first of these animals.
We have represented on our plate two males and a female in the fore
ground, with a flock of these timid creatures running at full speed in the
distance.
We subjoin the following account of the Antelopes seen by J. W. Audubon
and his party on their overland journey through Northern Mexico and
Sonora to California.
•' Leaving Altar, Sonora, the country was flat and uninteresting, except
that large patches of coarse grass, sometimes miles in length, took the
place of the naked clay plains we had been riding through. The tall
cactus, described by Fremont and Emory, in its eccentric forms was remark-
able enough even by daylight, but at night, a very little superstition, with
the curved and curiously distorted forms, produced in some cases by dis-
ease of the plant, or by the violent gales that periodically sweep those
prairies, might make the traveller suppose this was a region in which
beings supernatural stalked abroad. The shrill whistle of the Antelope, new
to us all, added to the wild and unearthly character of the scene. The
Maricapos Indians were said to be friendly, but we did not hiow it, and
VOL. ir. — 2C)
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202
PRONG-HORNED Ai'^TELOPE.
after our long watchings against Camanche, Apatche.Wako and Paramanii,
who among us, as we knew how Indians sometimes personate the animals
of the section they live in, but listened with intense interest to the slightest
noise foreign to our previous knowledge. The short quick stampings of" im-
patience or nervousness, continually repeated by the animals, were, how-
ever, soon distinguished in the stillness of our prairie camp at night, and
feeling thus assured that only one of the deer tribe was the cause of
our anxiety, blankets and tent soon covered us, and we left the beautiful
and innocent creatures, now that we knew them, to their own reflections,
if any they made, as to who and what we were, until morning.
At day light, Khoades and Van Horn, two hunters good as ever ac-
companied a train across the broad prairies ranged over by Bufl^alo,
Elk, or Deer, looked out the trails, and reported Anteloj)es ; but brought
none to camp ; not expecting to see any more of this herd, we started on
our tramp towards the great Sonora Desert.
Stevenson had a new horse, and as he had never ueen mounted with-
out blindfolding him, after the Mexican fashion with young horses, being
wild, his owner, by way of making him more gentle, commenced beat-
ing; him with a stick that might havfe been selected to kill him ; before
I had time to know what was going on and interfere for the poor
horse, he had looked to his own interests, pulled away, and with a
bounding gallop went off, like an escaped prisoner, leading four of our
best men and horses some ten miles ahead of the train, and when the
runaway was at length overtaken, Van Horn, Pennvpacker, Mc. Cusker,
road was slight, and on reaching it again, no trail told that the company
horses, when simultaneously we saw the back of a deer or Antelope ; its
head was hidden by the tall grass in which it was grazing on the soft juicy
young shoots at the roots of the old tussocks: Van Horn, with his unerring
nim and Mississippi rifle, the eccentric twist of which, no doubt taken from
Wesson's patent, renders these guns superior to all we have tried, was told
to kill it. For a few seconds he was lost to our sight, though only a
hundred yards from us, so low did he squat in the sparse tufts of def\'l
grass and stinking wormwood. How curious it is to stand waiting the
result of the skill and caution of the well iried hunter, at such a time ;
again and again we saw the back of the Antelope, as he passed one bunch
of shrubbery after another, but never saw our hunter: at every moment
we expected to see the wary animal with sense of smell so keen as nine
times out often to save him from his enemies, bound away ; but how difle-
rent was his bound when he did leap, not forward, but straight upward
PRONG-HORNED ANTELOPE.
20B
And now we saw Van Horn, a quarter of a mile off, running to where the
last leap was made by his prey, and then came on ihe sluggish air, the
crack of his rifle, almost after we had forgotten to listen for it, as a rifle
cracks nowhere except on prairies, where neither woods, rocks or hills send
back the sound. When I saw this beautiful creature, a most magnificent
male, the first I had ever seen in the flesh, thougb the drawing for the
it! delicate even to the descriptions of the gazelle, muscular and sinewy
as the best bred grey hound that Scotland ever produced.
I anticipated a treat, as Van Horn gave me a hind quartei for our men,
which I tied doubly secure to my saddle. But when night came, afl;er ten
hours' ride, although we enjoyed our steak .he deer of the Cordilleras was
too fresh in our memories to permit us to say that this Antelope was the
* * * " The eastern spurs of the coast range were just behind us ; the
black-tailed deer was scarcely past, for a few miles back, high up on one
of theconical velvety hills of this range, we had seen three, looking at us
from under one of the dwarf oaks that grow at a certain altitude, in forms
peculiar to this country; above or below, either a different formation
or total absence of shrubbery occurring. We were winding along the
base of a moderate line of hills of the Sierra Nevada, when what we
took for a flock of sheep, the trail of which we had been following for three
days on the way to the mines from Los Angeles, was discovered, and we
hoped for nmtton, to say nothing of the company we anticipated ; but our
flock of sheep was like the ' Phantom Bark,' for it ' seemed never the
nigher,* au contraire, turning a hill went out of sight, and we never got
another view ; we saw another flock some miles on, and at first, suppos-
ing it the same, wondered how they could travel so fast. This was
probably another portion of the one we had trailed for so many days.
Wc were gratified by the whole flock running ne.-ir us, from which we
argued we were in the chosen country of tlie Antelope, the broad Tule
valley. The flock ran 'shearing' about, as the formation of the land com-
pelled them to turn to the right or left, showing their sides alternately in
light and shade. When they are on the mountain sides and discover a
foe, or any object that frightens them, the whole flock rush headlong for
the plains, whether the enemy is likely to intercept them or not, and they
seem to fly with the single idea, that they are in a dangerous place, and
must change it for some other, no matter what ; at times a whole flock
would run to within shot of our company, determined as it were to go
through the line, and I believe in one or two instances would have done
so, if they had not been shot at by our too impatient party. When on
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PRONG-HORNED ANTELOPE.
the plains, the same desire possesses them to get to the hills, and back
they go a hundred or two in a flock, seldom slackening their speed, ex-
cept for a few seconds to look again, and be more frightened than ever
at what had first startled them. The rolling hills of the western line of
the Sierra Nevada were their most favourite locality in this valley, as
far as wc saw, but Layton and myself met an accidental individual or
two, nearly up to Sacramento city, as we travelled through the beautiful,
park-like scenes of this portion of California to the diggings of the head
waters of the " American Fork."
As to the shedding of the horns of this species, I never was able to as-
certain it, but a fine buck we killed, late in November, had a soft space
between the head and horn, over the bone, that looked as if it had grown
that length in one season. A young Antelope is better eating than a deer,
but an old one, is decidedly goaty.
GEOGRAPHICAL DISTRIBUTION.
The Prong-horned Antelope is an inhabitant of the western portions of
North America, being at no time found to the east of the Mississippi
river. Its most northerly range is, flccording lo Richardson, latitude 53°
on the banks of the north branch of the Saskatchewan. They range
southerly on the plains east of the Rocky Mountains into New Mexico.
The precise latitude we have not been able to ascertain, but we have seen
specimens that were said to have been obtained along the eastern ridge of
the mountains within the tropics in Mexico. The account given by Hernan-
dez, as well as his bad figure of his Teuthlnmucame, can apply to no other
species ; this was obtained in Mexico. Lewis and Clarke found it on the
plains west of the Columbia River, and it is now known to be an inhabi-
tant of California. It has, therefore, a very extensive geographical range.
general remarks.
We have after much reflection and careful examination, concluded to
adopt Mr. Ord's genus Anlibcapra for this species. It diflfera in so many
particulars from the true Antelopes, that naturalists will be compelled
either to enlarge the character of that genus, or place it under one already
formed. Its horns are branched, of which no instance occurs among all
the species of Antelope ; it is destitute of crumens or lachrymal openings,
and is entirely deficient in the posterior or accessory hoofs, there being
only two on each foot.
Major Hamilton Smith, (Cuv. Animal Kingdom, Vol. v., p. 321,) formed
a genus under the name of Dicranocerua, under which he placed a second
species which he named Apalmata. Although the generic name given by
PRONG-HORNED ANTELOPE.
205
Smith is m many respects preferable, as being more classically correct,
still, if we were to be governed by the principle that we should reject a
genus because the compoi I lul word from which it is derived is composed
of two languages, or if it does not designate the precise character of the
species, we would be compelled to abandon many familiar genera, estab-
lished by Linnaeus himself.
The specific name of Ord, we have also adopted in preference to the
more characteristic one "furcifer" of Smith, under a rule which we have
laid down in this work not to alter a specific name that has been legiti-
mately given.
We havo added the A palmata, palmated Antelope of Major Smith, as a
synonyme. We have compared so many specimens differing from each
other in shades of colour and size of horns, that we have scarcely a doubt
of his having described a very old male of the Prong-horned Antelope.
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CEIIVUS MACROTIS.— Say.
Mule Deer.
?LATE LXXVIII. Female— Summer Pelage.
C. cornibus sub-dichotomo-rarnosis ; auriculis longissimis ; corpore
supra pallide rufescente-fusco, cauda pallide rufescente cinere^, apice
compresso subtus nudl-osculo nigro.
CHARACTERS. ,
Horns cylindrical, twice forked ; ears very long ; body above, broivnisli
grey ; tail short, above, pale reddish ash colour, except at the crircmity on its
upper surface, where it is black. Hair on the body coarse, like that of the
Elk ; very long glandular openings on the sides of hind legs.
SYNONYMEa.
«
Jumping Deer. Umfreville, Hudson's Bay, p. 164.
Black Tailed or Mule Deer. Gass Journ. p. 55.
Black Tailed Deer, Mule Deer. Lewis and Clarke, Vol. 1, pp. 91, 92, 10(5,
152, 239, 2G4, 3-J8. Vol.2, p. 152. Vol. 3. p. 27, 125.
Mule Deer, Warden's United States. Vol. 1, p. 245.
Cekf Mulet. Desmarcst Mam., p. 43.
Black Tailed or Mule Deer. James Long's Exped. Vol. 2, p, 276,
Cervus Macrotis, Say, Long's Expedit. Vol, 2, p, 254,
" Harlan Fauna, p, 243.
" Sabine. Franklin's Journey, p. 667,
«• Godman's Nat. Hist, Vol, 2, p, 305,
Great Eared Deer. Griffith's An, King, Vol. 4, p, 133 ; Vol. 5, p. 794.
description.
In size this species is intermediate between the Elk and the Virginian
Deer, and a little larger than the Columbian Black Tailed Deer, to be
noticed hereafter. It is a fine formed animal, bearing a considerable re-
semblance to the Elk, its long ears constitute its only apparent defor-
mity.
Male, — Antlers slightly grooved, tuberculated at base, a small branch
near the base, corresponding to the situation and direction of those of the C.
Virginianus. Thr curvature of the anterior line of the antlers, is similar in
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207
direction but less in degree than in the Common Deer ; near the middle of
the entire length of the antlers they bifurcate equally and each of these
processes again divides near the extremity, the anterior of these smaller
prongs being somewhat longer than the posterior ones. The lateral teeth
are larger in proportion to the intermediate teeth than those of the Virginia-
nus. The ears are very long, extending to the principal bifurcation, about
half the length of the whole antler. The lachrymal aperture is longer than
m the Virginian Deer, the hair is coarser and is undulated or crimped like
that of the Elk ; the hoofs are shorter and wider than those of the common
Deer, and more like those of the Elk, the tip of the trunk of the tail is some-
what compressed and almost destitute of hair.
Female. — Summer Pelage, — In the length and form of its ears, the animal
from which we describe constantly reminds us of the mule, and in this parti-
cular may noc have been inappropriately named the Mule Deer. The fe-
male is considerably larger than the largest maleof the Virginian Deer we
have ever examined. The head is much broader and longer from the eye
to the point of the nose, the eye large and prominent, the legs stouter, and the
tail shorter. The gland on the outer surface of the hind legs below the
knee, covered by a tuft of hair, is of the unusura length of six inches,
whilst in the common deer it is only one inch long. Around the throat,
the hair is longer than in the corresponding parts of the Virginian Deer,
and near the lower jaw under the throat, it has the appearance of a small
tuft or beard. The tail of the summer-specimen is slightly tufted, indi-
cating that in winter it might have a distinct tuft at the end. It is
rounded and not broad and flat like that of the Virginian Deer.
The hair on the body is coarse, and lies less compact and smooth, that
on the thighs near the buttocks, resembles white cotton threads cut off ab-
ruptly.
COLOUR.
Upper portion of nose and sides of face ashy grey ; the forehead is dark
browo, and commences a line running along the vertebrae of the back,
growing darker till it becomes nearly black. Eyebrows and a few streaks
on and along the neck dark brown. Neck, and sides of body, yellowish
brown. Outer surface of legs a shade lighter than the sides of the body.
Under the chin, inner surface of legs, and belly, greyish white. Belly
between the forelegs brownish or yellowish-brown, a line of which colour
runs up to the neck. It differs from the Virginian Deer in being destitute
of the dark markings under the chin, and has them less conspicuous around
the nose. From the root of the tail extending downwards on both but-
la
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208
MULE DEER.
tocks there is a lightish patch seven inches in diameter, making an ap-
proach to the yellowish white spot on the buttocks, so characteristic
in the elk, rocky mountain sheep, and pronged liorned antelojje. From the
root of the tail to near the extreirrity the hairs are ashy white. Point of
tail for two inches black.
There are no annulations on the hair, which is uniform in colour from
the roots.
DIMENSIONS.
Female.
Nose to anterior canthus of eye
Length of eye
Nose to opening of ear
« end " "
Nose to point of shoulder
Nose to root of tail
Tail vertebrae ...
End of hair ...
Tip of shoulder to elbow
" " " to bottom of feet
Height to rump
Girth b.ick of sh' aider
Round the neck
Nose to angle of mouth
Between eyes at anterior canthus
Behind the eyes round the head
Weight, 132 lbs.
Dimensions of a Male, as given by Say.
Length from base of antlers to origin of basal process,
From basal process to principal bifurcations
Posterior branch ....
From anterior base of antlers to tip of superior jaw
^fthe ears - - . . -
Trunk of the tail ....
Hi'ir at thi tip of tail - •
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MULE DEER.
HABITS.
20l>
The first opportunity was afforded us of observing this magnificent
animal, on the 12th of May as we were ascending the Missouri, about
eleven hundred miles above Fort Leavenworth. On winding along the
banks, bordering a long and wide prairie, intermingled with willows and
other small brush wood, we suddenly can.e in sight of four Mule or black-
taded Deer, which after standing a moment on the bank and looking at us
trotted leisurely away, without appearing to be much alarmed. After they
had retired a few hundred yards, the two largest, apparently males, ele-
vated themselves on their hind legs and pawed each other in the manner
ot the horse, ^hey occasionally stopped for a moment, then trotted off
again, appearing and disappearing from time to time, when becoming
suddenly alarmed, they bounde.l off at a swift pace, until out of sight
Ihey did not trot or run as irregularly as our Virginian Deer, and they
appeared at a distance darker in colour, as the common Deer at this
season is red. On the 2.5th of the same month, we met with four others
which m the present instance did not stop to be examined ; we saw them'
at a distance rapidly and gracefully hurrying out of sight. On the evening
ot the same day, one of our hunters brought to us a young Buck of this
species, the horns of which, however, were yet too small to enable us to
judge what would be their appearance in the adult animal. When on the
Upper Missouri, near Fort Union, we obtained through the aid of our hun-
ters, the female Black-tailed Deer, from which our figure, description and
measurements have been made. We regret exceedingly that we were so
unfortunate as not to havs been able to procure a male, the Jelineation
of which wp must leave to our successors.
The habits of this animal approach more nearly those of the Elk than
of either the long-tailed or Virginian Deer. Like the former they remove
far from the settlements, fi,, --^m the vicinity of the hunter's camp and
when once fairly started, run lor a mile or two before they come to a
pause.
The female produces one or two young, in the month of June.
We have figured a female an summer pelage, and have represented the
animal in an exhausted state, wounded through the body, and about to
drop down, whilst the hunter is seen approaching, through the tall grass,
anticip_ ing the moment when she will reel and fall in her tracks.
OEOGRAPHICAL DISTRIUUTION.
The Mule Deer range along the eastern sides of the Rocky Mountains,
through avast extent of country; and according to Lewis and Clauke
vol 11.- --'.>/.
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MULE DEER.
are the only species on the mountnins in the vicinity of the (irst falls of the
C()luml)iii llivcr. 'I'licir lii^licst nortlicrn riiny;c, fict-ordiiiy; to RiriiAUDHoN, is
the banks of the Saskiifchewaii, in .-ilmiit latitude Ti 1° ; they do not come to
the eastward of lonuiMide lOS in that parnllel. He represents them us
numerous on the Guamash Hats, which border on the Kooskooskie River
We found it a little to the east of Fort Union on the Missouri River, It
rani^es north and south aloiii^ the eastern sides of the Rocky Mountains
through many [)arallels of latitude until it reaches north-western Texas,
where it has recently been killed.
CSRNERAL RBMARKB.
Since the days of Lewis and Clarke, an impression has existed among na-
turalists that there were two species of black-tailed Deer; the one exist inj;
to the east of the Rocky Mountains, and the other, bordcrin}? on the Pacilic,
and extendi;^}^ through upper California. Although the descriptions of those,
fearless and enterprising travellers are not scientific, yet their accounts
of the v.irious species of animals, existing on the line of their travels, have
in nearly every case been foun<l correct, and their description of habits
very accuralte. They state that "the black-tailed fallow I)e«'r are peculiar
to this coast (mouth of the Columbia.) and are a distinct species, partaking
equally of the qualities of the Mule and the common Deer (C. Virgimduus.)
The receptacle of the eye more conspicuous, their legs shorter, their bodies
thicker and larger. The tail is of the same length with that of the common
Deer, the hair on the under side, white ; and on its sides and top of a di op
jetty black; the hams resembling in form and colour those of the Mule Deer,
which it likewise resembles in its gait. The blnck-tailed Deer never runs
at full speed, bm bounds with every foot from the ground at the same time,
like the Mule ^ jr. He sometimes inhabits the woodlands, but more often
the prairies and open grounds. It may be generally said that he is of a size
larger than the comm>:n Deer, and less than the Mule Deer. The flesh is
seldom fat, and in flavour is far inferior to any other of the species ! It will
be seen from the above, that they regarded the Mule Deer of the plains of
Western Missouri as a distinct species from the black-tailed Deer, which
existed along the Pacific coast near the Columbia river.
Say gave the first scientific description of the Mule Deer, which he named
" Cervus Macrotis" which having the priority we have retained. Richard-
son, whilst at the Saskatchewan, sought to obtain specimens of this animal
for description, but it being a season of scarcity, the appetites of the hunters
proved superior to their love of gain, and they devoured the Deer they had
shot, even to their skins. When after his return to Europe, in 1829, he
MULE DEER.
911
published the animals ohtair ed in the expedition, he very properly added
such other species as had been c«»llected by th,- labours ol" Don.; ^ r- -i;„.
MOM) and other njtfiiralists, who Iwid explored the norther- kI J
porfions of Auieric;!. Findinyr in the Zoological Musecn- -jio i ,i
black-tailed Deer, procured on the western coast of Am; lic i.> i; m, :ig,
he concluded that it was the species described by Say, ( . '»■ utis ; at
the close of his article, he refers to the animal mentioned by LEwir. and
Ci.ARKK, as the black-tailed Deer of the western coast, of which he states,
that he had seen nospeci-nen, designating it (F.B. Am. p. 2.57) C. marrotis,
var. ColumhUinti. We have, however, come to , the conclusion tli.it the
animal described by Richardson was the very western species to which
Lewis and Clarkk refer, and that whilst his description of the specimen
was correct, he erred in the name, he having described not the Mule Deer
of Lewis and Ci,ark and Say, but the Columbian black-tailed Deer, oui
drawing of which was made from the identical specimen described and
figured by Richardson. We have named it, after its first describer, Cervux
Rir/uirilso/iii.
The following characters will serve to designate the species.
C. Richiirdsonii, considerably smaller than C. macrotis, the male of the
former species being smaller than the female of the latte-. The hair .if
C. iiuicrofis is very coarse and spongy, like that of the elk, that of C.
Richardsuniiis much finer and more resembles that of the Virginian Deer.
The ('. Richurdsoiiii has no glandular opening on the outer surface of the
hind leg below the knee joint, approaching in this particular the antelopes
which are also without such openings, whilst the corresponding portion in
C. macrotis is longer than that of any known species of Deer, being si\ inch-
es in length. They difler in the shape of their horns, C. Richardsonii having
the antlers more slender, much less knobbed, and leds covered with sharp
points than those of the latter. They are also destitute of the basal pro-
cess, so conspicuous in C. macrotis. We regret exceedingly that from cir-
cumstances beyond our control, we have been enabled to give a figure
of the female only of C. macrotis, and of the male ily of C. Ricliardxonii.
The former was figured from the specimen we ined at F'ort Union,
and for the latter we are indebted to the directors ol the Zool. Society of
London, who very kindly permitted us to make a drawing from the spc-
cinieii previously described and figured by Richardson.
Note. — In connection with tliis subject, we arc deeply p.nined to be comiiellcd to notice
the obstnu'timis thrown in the way of our pursiil;.' l>y the directors of the National InKtituto
at Wasliinfjton, whiclt city we vi-<iled sliorlly after the return of our explorinj; expedition,
when we were kindly invited hy Mr. Peale to an examination of tiie valuable specimens of
Natural History, collected by our adventurous countrymen. We pointed out to iiim one
ortwo skins of the blacktiiiled Deer from the Western coast, whijli we bcth agreed diifered
«.
t
212
MULE DEER.
from tlie C. Macrolis of Say. We proposed to him that he should give ii short descrip-
tion of the species, and select the name, wliich we would afterwards adopt in our worii
tiiis is in accordance with the mode usually pursued, and would have only occupied an hour.
After the lapse of several years, we made an ai)|)lication by letter to the directors of the
Institution for the privi]i'i,'e of making a drawing of the specimen ; tiiis we were not only
refused, but were even denied the privilege of looking at the si)eeimen, which wo were very
an.xious to sec, in order to bo enabled to point out in the most satisfactory manner the
characteristics by which these two closely allied species of Doer inhabiting our country
could be distinguished from each other.
We cannot but contrast the narrow-minded policy pursued towards us in our application at
Washington, with the liberalitj and generosity which was at all times extended to us in Eurojjc
under similar circumstances. When we visited England in 1 838, the Directors of the Zoologicid
Society opened its museum and assigned to us a private room, of which they gave us the
key, and which we occupied for nearly a month — the specimens were tiiken from the cases
by theu- attendants and brought to us, and when we discovered in the collection undos^cribed
species, we were encouraged and aided in descril)ing them. The same facilities were aiTorded
us in the British museum, and in those of Edinburgh, Paris, Berlin, Dresden, and Zurich.
The British Government, as well as our own, gave us all the assistance which could be
rendered by cither, consistent with other public services, and we di'rived material advantages
from the aid afforded lis by the revenue service and the various military stations we have
visited in our researches, in Labrador— in Florida — in the tar West, and in Texas.
We know not who were the Directors of the National Institute when our reasonable
request was so cavalieriy rejected, nor have we inquired whether any changes in policy
have since taken place in regard to the collection of animals at Wasiiington, but we feel it
our duty publicly to protest against a conduct so narrow, selfish, and inconsistent with the
liberality of our free institutions and so little adapted to nromote one of the objects sought
to be gained by the exploring expeduion — viz ; the advancement of natural history.
When the Hudsons Bay Company received an intimation that we would be glad to obtain
any specimens they could furnish us from their trading posts in the arctic regions, they im-
mediately gave orders to their agents and we secured from them rare animals and skins, prf>-
cured at considerable labour and expense, and sent to us without cost, knowing and belitv.
ing that in benefitting the cause of natural stdence they w ould receive a sufficient reward
213
SPERMOPHILUS ANx\ULATUS.-Aud. and Bach.
PLATE LXXIX.— Male.
S. Super cervinus, pilis nigris, interspersis, subtus albido. CaudS cor-
pore longiore, annulis, 17-20 nigris.
CHARACTERS.
Reddish-hrown ahow, speckled with black beneath. Tail, lohich is longer
than the body, annulated, with from seventeen to twenty black bands.
SYNONYME.
Spekmophilus Annulatus. Aud. & Bach. Transactions of the Academy of
Natural Sciences, Oct. 5th, 1841.
DESCRIPTION.
In size, this species is scarcely larger than the Hudson's Bay Squirrel
OSf. Hudsonins.) I„ the shape of the head it resembles Spermophilus
i'arryt. The ears are quite small, being scarcely visible above its short
coat of rather coarse, adpressed hairs; they are thickly covered with hair
on both surfaces. The nose is sharp ; whiskers, (which are numerous,)
the ength of the head. Eyes of moderate size, situated on the sides of the
head. The os-frontis is rounded between the orbits, as in S. Frauhlimi.
The cheek pouches are pretty large, and open into the mouth immediately
anterior to the grinders. The body is more slender than the spermophiles
in general, and in this, and .several other peculiarities which will be men-
tioned, this species approaches the genus Sciurus. On the fore-foot a
slmrp, conical nail is inserted on the tubercle which represents th., thumb
There are four toes, covered to the extremities with a close, smooth coat
* \7' , 1' T' '""' '^" '''""'■'^ '"" ^'•^ "'' •"•l"''^' '^"'^^fh. The second
and third, which are longest, are also uniform in length. The nails are
short crooked and sharp, like those of the Squirrels, and not like those of
the Marmots and Spermophili in general, which are long and slender
and but slightly curved. The legs are long and slender. The hair on
the back IS rather short, and lies close and smooth. The short fu,
beneath this coarser hair is rather sparingly distributed. On the under
M
(
! : t
^^iW
I
214
ANNULATED MARMOT SQUIRREL.
I!|
surface, the hairs are longer, and so thinly and loosely scattered as to
leave the skin visible in many places, especially on the abdomen, and
inner surface ol the thighs. The hind feet, which are thiciciy covered
with short, smooth hairs, have five toes. The soles, as well as palms, are
naked. The tail, by its great length and singular markings, presents
a distinguishing peculiarity in this species ; it is flattened, and the hairs
admit of a distichous arrangement ; but the tail is narrower, and less
bushy than those of the Squirrels.
COLOUR.
The incisors are deep orange ; nails, brown ; whiskers, black ; nose and
sides of the face, chestnut-brown. There is a line of soiled white above
and around the eyes. The hairs on the upper surface are yellowish-
brown at the roots, barred about the middle with black ; then another
line of yellowish-brown and tipped with black, giving it a dark, greyish-
brown, and in some lights a speckled appearance. The small spots are,
however, no where well defined ; upper surface of the feet and legs,
yellowish-brown ; the under parts, chin, throat, belly, and inner surface of
the legs and thighs are white. The tail is annulated with about nineteen
black, and the same number of cream-coloured bands, giving it a very con-
spicuous appearance. These annulations commence about three inches
from the root of the tail, and continue to be well defined till near the
extremity, where the colours become more blended, and the rings are
scarcely visible. On the under surface, the tail is pale reddish-brown,
irregularly, and not very distinctly barred with black.
DIMENSIONS.
Length from point of nose to root of tail,
" tail vertebra?, --....
" to end of hair, ......
From heel to end of middle hind claw, ....
Height of ear, posteriorly, .....
Length of longest fore-claw, .....
Length of longest hind claw, .....
HABITS.
We po5;3ess no knowledge of the habits of this species, but presume
from its form, that it possesses the burrowing propensities of the genus.
All the SpcrmophiH avoid thickly wooded countries, and are either found
in rocky localities, or burrowing in the prairies.
ocbea.
Linos-
8
2
8
9
4
1
10
H
2
2i
ANNULATED MARMOT SQUIRREL.
GEOGRAPHICAL DISTRIBUTION.
216
The specimen we have described above, was obtained on the Western
Prairies, we believe on the east of the Mississippi river ; the locality was
not particularly stated. It was politely presented to us by Professor
Si'ENCER F. Baird, of Carlisle, Pennsylvania, a young Naturalist of emi-
nent attainments.
i
general remarks.
In every department of Natural History, a species is occasionally found
which forms the connecting link between two genera, rendering it doubt-
Ail under which genus it should properly be arranged. Under such cir-
cumstances, the Naturalist is obliged to ascertain, by careful examination,
the various predominating characteristics, and finally, place it under the
genus to which it bears the closest affinity in all its details. The Sper-
mophili are intermediate in character between the Squirrels and Mar-
mots. They have the lightness of form of the former, and burrow in the
ground like the latter. By their cheek pouches, of which the true Squir-
rels and Marmots are destitute, they are distinguished from both. The
second inner toe on the forefoot of the Spermophili is the longest, whilst
in the Squirrels the third is longest. But in these closely-allied
genera, there are species which approach those of another genus.
Thus our Maryland Mnrmot, {A Monax,) has a rudimentary cheek-pouch,
in which a pea might be inserted, yet in every other particular it is a
true Arctomys. The downy Squirrel, {Sciurus lanuginosus, see Journal
Acad. Nat. Science, Vol. 8th, part 1st, p. 07,) by its short ears, broad
head, and not very distichous tail, approaches the Spermophili, yet by its
being destitute of cheek-pouches, by its soft, downy fur, and its hooked,
sharp claws, of which the third, as in the Squirrels, is longest, it is more
allied to Sciurus. On the other hand, the species now under considera-
tion has the long legs, slender form, and sharp, hooked claws ol" the
Scjuirrel. The two middle toes of the fore-feet being of equal length,
prove its affinity to both genera ; but in the general shape of its body, its
cheek pouches, its short ears, and smooth, rigid hair, it must be regarded
as belonging to the genus Spermophilus. We consider this species and
the downy Squirrel as connecting links between Sciurus and Spermo-
philus, as we regard Sciurus Hudsonius tlio connecting link between
Tamias and Sciurus
j; i-
! !
216
ARVICOLA PINETORUM.— Leccnte.
Leconte's Pine-Mouse.
PLATE LXXX.— Male and Female.
A. Capite crasso ; naso obtuso ; vellere curto ; molli bombycino, instar
velleri Talpae ; supra I'usco-cana, subtus plumboo.
characters.
Head large, nose blunt ; fur short, soft, silhj and lustrous, like that of the
mole. Colour, above, brown, beneath^ plumbeous.
SYNONYMES.
PsAMMOMv's PiNETORUM, Lo Coiitc, Annals of the Lyceum of Niitural History
of New-York, Vol. III. p. 3, p. 2.
Akvicola ScALOpsoiDES, Mole Arvicola. Aud, and Bach. Transactions Acad.
Nat. Sciences, October, 184L
Arvicola Oneida, De Kay, Nat. Hist., N. Y., p. 88.
DESCRIPTION.
This species bears some resemblance to Wilson's Meadow Mouse ; it
is, however, less in size, and its fur is shorter, more compact and glossy ;
body rather stout, short and cylindrical ; head large and short ; nose blunt,
and hairy, except the nostrils, which arc naked; incisors of moderate
size ; moustaches, fine, and nearly all sliort, a few reaching the ear ;
eyes very small ; auditory openings large ; ears very short, not visi-
ble beyond the fur, thin and membranous, with a few scattered hairs
on the upper margin ; neck short and thick ; logs short and slender,
covered with very short, adpressed hairs, not concealing the nails ;
palms naked. There are four toes on the fore foot, of which the
second, on the inner side, is the longest, the first and third nearly equal,
and the fourth shortest ; in place of a thumb, there is a minute, straight,
but not blunt, nail. The hind feet have five toes, the middle longest,
the two next on each side being of equal length, and a little shorter
than the middle one ; the inner toe is considerably shorter, and tlip
fourth, placed far back, is the shortest. The nails are weak, nearly
straight, sharp, but not hooked. Th(! fur on the whole body is short,
compact and soft, and on the l)ack, glossy.
PINE MOUSE.
217
COLOUR.
The eyes are black ; nostrils flesh-colour ; incisors light yellowish •
moustaches nearly all white, with a few interspersed of a dark brown
colour. Hair from the root plumbeous, tipped on the upper surface with
glossy brown. These tips are so broad that they conceal the ashygrey
colours beneath ; cheeks chestnut-brown, upper surface of tail brown
feet, hght-brown, nails, whitish. The hairs on the under surface are
shorter than those on the back, and instead of being broadly tipped with
brown, like those on the back, are very slightly tipped with very pale
brown and whitish, giving the chin, throat, neck and inner surface of legs
and whole under surface of body a pale ash colour. The line of demarc-
ation between the colours of the back and under surface, is very distinct
in most specimens, commencing on the edges of the mouth, running along
the sides of the neck, thence along the shoulder, including the fore legs-
along the sides, the two opposite lines meeting near the root of the tail
We have observed in this species a considerable difference in different
specimens, both in size and colour, having met some which were but
little more than three inches long, whilst others were five. In some the
colours on the back were of a much deeper brown than in others whilst
in others, the blown markings on the cheeks were altogether wanting,
It should be observed that in this species, as well as in all our field mice
the colours are much lighter, and inclined to cinereous after the shedding
of the hair in summer ; the colours gradually deepen and become brighter
toward autumn and winter, and are most conspicuously dark brown in
spring.
DIMENSIONS.
From point of nose to root of tail, -
Tail,
Another Specimen.
Tail
iDchus.
34
4i
3
I
HABITS.
The manners of this species do not diff^er very widely from those exhibit-
ed by many other field mice. They however, avoid low grounds, so much
the resort of the meadow mice, and prefer higher and drier soils
This mouse is rather an inhabitant of cultivated fields than of woods, and
IS seldom found in the forest far removed from the vicinity of plantations, to
which It resorts, not only to partake of the gleanings of the fields, but to lay
Its contributions on the products of the husbandman's labours, claiming a
share before the crops are gathered. In the Northern states, it is found
• i
oi,. ir.
-28.
II'. I I .-.
218
PINE MOUSE.
in potato fields and in vegetable gardens, gnawing holes into the sides of llw
potatoes, carrots, ruta-baga, and common turnips, following the rows whtsre
fireen peas and corn have been planted, bringing down threats of ven-
gcance I'rom the tarnicr on the poor ground mole, which, feeding only on
worms, is mside a kind of cal's-{)aw by this mischievous little field mouse,
which does the injury in most cases, wliilst the other is saddled with the
blame. In the South it is, next to the Norway rat, the most troublesome
visitant of the cellars and banks in which the sweet potato is stored,
destroying more than it consumes, by gnawing holes into the tubers, and
causing them to rot. Wherever a bed of Guinea corn, Egyptian millet,
or Guinea grass is planted, there you will soon observe numerous holes
and nests of this species. We have recently seen an instance where a
large bed of kohlrabi was was nearly destroyed by it ; the bulbs appear
ing above the surface were gnawed into holes, which, in some instances,
penetrated to the centre. Our friend, the owner, had, as usual, laid the
mischief on the broad shoulders of the hated and persecuted ground mole,
of whose galleries not a trace could be seen in the vicinity. A number
of small holes at the root of a stump, in the garden, indicated the true
author of these depredations, ana on digging, about a dozen of Le-
conte's field Mice were captured. This species is particularly fond of
the pea or ground nut, (hypogea.) On examining the beds where this
nut is cultivated, we have observed the rows on whole acres perforated
in every direction by small holes, giving evidence that this troublesome
little pest had been at work. In endeavouring to save and collect the
seeds of the Gnma grass, {Tripsricinn (iarti/loidcs.) we generally found
ourselves forestalled by this active and vorjicious liltle rat.
This species has young three or foiu" times during the summer. One
which we had in confinement, produce:! young three times, having three,
seven, and four, in the difl'erent broods. The young were nearly all raised,
but, when full-grown, became pugnacious and persecuted each other so
much that we were obliged to separate them. They were almost exclu-
sively fed on ground nuts, corn meal and sweet potatoes, but seemed to
relish both boiled rice and bread. We have seen nine young taken from
one nest.
The nest of this species is generally found under ground, at the distance
of about a foot from the surface ; it is small, and composed of light, loose
materials, collected in the vicinity.
This prolific field rnt possesses many enemies to diminish its numbers.
The house cat not only watches for it about the fields and gardens, but is
fond of devouring it, whilst the bodies of shrews and ground moles are
not eaten. The very common Owl, (Si/niiiim luhulumtiii,) the Bam
FIELD MOUSK.
219
Owl {StHx Americauf,,) the Weasel, Ermine, and Mink, all make this
species a considerable part ol' their subsistence.
The only note we iiave ever heard Irom this mouse is a low squeak,
only uttered when it is eiliier struck suddenly or greatly alarmed. In a
state of confinement it was remarkably silent, except when two were en-
gaged in fighting.
GEOGRAPHICAL DISTRIBUTION.
Le Conte's Field Mouse has an extensive geographical range. We
have received specimens Irom our friend. Dr. Brewer, obtained in Massa-
chusetts. It is found in Conncolicut, is quite abundant on the farms in
Rhode-Lsland, and in the immediat<" vicinity of New- York. We found it
at Milestown, a few miles from Philadelphia. Mr. Hi. ffin sent us several
specimens from Virginia. We procured it in North Carolina, and re-
ceived a specimen from Dr. Barritt, Abbeville, South Carolina. It
becomes more abundant as you approach the seaboard, in Carolina and
Georgia; and we have specimens sent to us from Alabama, Mississippi and
Florida. We have traced it no farther south, have not heard of it to the
west of the Mississippi, and are inforgied that it does not exist in Texas.
GENERAL REMARKS.
From the diminutive figure in Wilson's Ornithology, we might be led
to the conjecture that he had this little species in view. The accurate
description given by Orh. applies, however, only to the Arijicola Penn-
tijlvanicM. The first scientific description that appears of this species was
given by Le Conte, (Annals of the Lyceum of Nat. Hist. N. Y., Vol. HI.,
p. 3.) Finding that there were some variations in the dentition from the
long estai)lish('(l genus Armcohi. he formed for it a new genus, under the
name of P.saiiwiiuis. As this name, however, had been p-e-occupicd by
Riii'PEi. for an Arabian species, the American translator, (Dr. McMiiRTRiig
of Cuvier's Animal Kingdom, proposed changing the genus to Pilyniis, Pine
Mouse. The variations in the teeth, however, we have found by compari-
son, do not allurd sufiicient cliaracters to warrant us in removing it from Ar-
vicoh, to which, from its shape and hal)its, it seems legitimately to belong.
We do not feel warranted in changing the specific name of Lb Conte
bur, that name is not expressive of one of its characteristics, as, although it
may have been found in the pine woods, we have never, in a single in-
stance, detected it in such loealilies. We have auvays found it either in
the open fields, or along fences, in llie vicinity of gardens and farms.
This species is subject to many changes in coloin-, and is so variable in
size, that it is easy to mistake it ; hence we have added as synonymes, our
A, Scalupsoides, and the .1. Oneida oi" Dr. De Kay.
i
i\
220
CERVUS VIRGIN I ANUS.— Pennaut.
Common American Deer.
PLATE LXXXI.— Fawn.
PLATE CXXXVl.— Male and Female.— Winter pelage.
C. cornibus mediocribus, ramosis, sub-complanatis, retrorsum valde in-
clinati-s, dein antrorsum versLs ; ramo basali-interno retrorso ; ramis
plurimis posticis, retrorsum et sur.sum spectantibus, sinubus .siiborbifalibus
plicam cutaneam formaiitibus; vellere aestate fulvo, hyeme canescente-
tusco.
CHARACTERS.
Horns middle sized, tending to jlatten, strongly bent hack and then for-
wards ; a basal antler on the interval side, pointing baclarards ; several
snags on the posterior edge, turned to the rear, and upwards ; suborbital sinus
making a fold; colour, fulvous in sumt .; gray-brown in winter.
SYNONYMES.
VmaiNiAN Deer. Penii. Syn., p. .51
« «' Penn. Quadrupeds. Vol. 1, p. 104.
" «« Shaw's General Zoology. Vol. 2, p. 284.
Amkrikanischer Hirsch. Kalm Reisc. Vol. 2, p. 320. 3d p. 482.
ViHGiNiscnER Hirsch. Zimmerm. Geogr. Gesch. Vol. 2, p. 129.
Cekf de la Lol'isiane. Cuv. Regn. An., lere p. 256,
Cervus Vjrginiancs. Gmel. Vol. 1, p. 179.
Dama Americanos. Erxl. Syst., p. 312.
C. ViRGiNiANus. Harlan. Fauna Am., p. 239.
" Godm. Am. Nat. Hist. Vol. 2. p. 306.
C. Mexicanus kt clavatus. Haniilton Smith, p. 315. Griff. Cuv. Vol. 4. p. 127.
Vol. 5, p. 315.
C. ViRGiNiANus. Dekay's N. Y. Fauna, p. 113.
DESCRIPTION.
Muzzle sharp ; head rather long ; eyes large and lustrous ; lachrymal
pits covered by a fold of the skin. Tail moderately depressed. Legs
VIRGINIAN DKER.
221
slender. A glandular pouch surrounded by a thick tut't of rigid hairs in-
side of the hind legs.
COLOUR.
The Virginian Deer varies considerably in colour at different periods of
the year. In the spring it is of a dusky reddish or fulvous colour above,
extending over the whole head, back, upper surface of the tail and along
the sides. In the autumn it is of a bluish or lead colour, and in winter
the liairs on the upper surface are longer and more dense and of a brown-
ish dark tint. Beneath the chin, throat, belly, inner surface of legs, and
under side of tail, white. There is no perceptible difference in colour be-
tween the sexes.
The fawns are at first, bright reddish-brown, spotted with irregular lon-
gitudinal rows of white. These spots become less visible as the animal
grows older, and in the course of about four months the hairs are replaced
by others, and it assumes the colour of the old ones.
F
4
DIMENSrONS.
Length from nose to root of tail,
of tail, (vertebrte),
" including hairs,
" Height of ear,
Feet, rnebea.
3 1
6
1 1
HABITS.
Perhaps no species of wild animal inhabiting North- America, deserves to
be regarded with more interest than the subject of our present article, the
Common or Virginian Deer ; its symmetrical form, graceful curving leap
or bound, and its rushing speed, when, flying before its pursuers, it passes
like a meteor by the startled traveller in the forest, exciting admiration,
though he be ever so dull an observer.
The tender, juicy, savoury, and above all, digestible qualities of its flesh
are well known ; and venison is held in highest esteem from the camp of
the backwoodman to the luxurious tables of the opulent, and, when not
kep^ too long ( a common error in our large cities by the way) a fat haunch
with jelly and chafing dishes is almost as much relished, as a "hunter's
steak," cooked in the open air on a frosty evening far away in the west
The skin is of the greatest service to the wild man, and also useful to the
ilweiler in towns ; dressed and smoked by the squaw, until soft and pliable
r
222
VIRGINIAN DEER.
it will not shrink with all the wettings to which it is exposed. In the form
ol'mocasins, iejjgings, and hunting shirts, it is the most nmterial j)art ofthe
dress of many Indian tribes, and in the civilized world is used for breeches,
gloves, gaiters, and various other purposes.
From the horns are made beautiful liandh's for various kinds of cutlery.
The timidity ofthe Deer is such, tiiat it hurries away, even from the
sight of a child, and it is but seldom that the hunter has ^ n' danger to ap-
prehend, even I'rom a wounded buck ; il does but little injury to the fields
ofthe j)lanter, and is a universal favourite with old and young of both sexes
in our Southern States.
The Viryiniiin, eras we wish to designate it, the Common Deer, is the
only large animal, if we except the bear, that is not driven from the vici-
nity of man by the report of the de'ir-driver's gun, or the crack of the hun-
ter's rifle ; the bufTalo and the elk are now rarely seen east of the Mis-
sissippi. Hunted by hounds and shot at from day to day, thc! Deer may re-
treat from this persecution for a little while, but soon returns again to its
original haunts. Although it scarcely ever occupies the same bed on suc-
cessive nights, yet it is usually ibund in the same range, or drive as it is
called, and often not fifty yards from the pla?e, where it was started before.
It is fond of lingering around fences and old fields, that are partially over-
spread with brush-wood, briar-patches and other cover, to screen it from
observation. In the southern Stares the Deer, especially in summer when
they are least disturbed, are fond of leaping the outer fences of plantations,
lying through the day in some tangled thicket, overgrown with cane, vines
and briars ; and in such places you may be so fortunate as to start an old
buck in August or September, and many an overgrown denizen of the
forest has bowed his huge antlers and fallen a sacrifice to his temerity in
seeking t resting-place too near some pea-patch, where his hoofs left traces
for many weeks of his nightly depredations.
This habit of resting during the day in the near vicinity of their feed-
ing ground, is however not universal. We during last summer were
invited to visit a large cornfield in which a quantity of the Carolina cow-
pea had been planted among the corn. This had been the nightly resort
of the Deer during the whole summer — their tracks of various sizes cov-
ered the ground, as if flocks of sheep had resorted to it, and scarcely a
pod or even a leaf was remaining on the vines. The Deer, however, were
not in the vicinity, where there were sc^veral favourable and extensive
covers ; they were trailed to some small islands, ii^ a marsh nearly two
miles off. We ascertained that the ] k-cr inhabiting the swamps on the
east side of the Edisto river, where there are but few cultivated farms,
were in the nightly habit of swimming the Edisto and visiting the pea-
VIRGINIAN DEER.
228
fields in Barnwell, on the opposite side, returning before duy-light to theii
customary haunts, some lour or live miles distant.
The localities selected by Deer as places of rest and concealment dur-
ing (he .lay are various, such as the season of the year and the nature of
the country tni-l climate may su-rgest to the instincts of tin animal. Al-
though we have occa.sioMally in mountainous regions, especially in the
iiigher mountains of Virginia and the Green Mountains of V.-rniont, de-
tected a Dec-r lying without concealment on an elevated ledge of bare
roeli, iiite the ibex and chamois on the Alps, yet as a general habit, the
annnal may be said to seek concealment, either among clumps of myrtle
or laurel bushes, (Knhnia), in large fallen tree-tops, briar-patches, clus-
ters of alder bushes, (ulnus), or in tall broom-grass, {Andropo^ron ]iissiti.
floras). In cold weather it prefers seeking its repose in some sheltered
dry situation, where it is protected from the wind, and w.-irmed by the
rays of the sun; and on these occasions it may be found in briar-patches
which face the south, or in tufts of broom-grass in old uncultivated liclds.
In warm weather it retires during the day to shady swamps, and may of-
ten be started from a clump of alder or myrtle bushels near some rivulet
or cool stream. To avoid the persecution of moscheto,.s and ticks, it oc
casionally, like the moose in Maine, resorts to some stream or pond and
lies for a time immersed in the water, from which the nose and a part of
the head only project. We recollect an occasion, when on sitting down
to rest on the margin of the Santee river, we observ(Hl a pair of antlers
on the surface of the water near an old tree, not ten steps from us. The
half-closed eye of the buck was upon us; we were without a gun, and he
was, therefore, safe from any injury we could inflict on him. Anxious to
observe the cunning he would display, we turned our eyes another wav
and commenced a careless whistle, as if for our own amusement, walkin-
gradually towards him in a circuitous route, until we arrived within a
few feet of him. He had now sunk so deep in the water that an inch
only of his nose, and slight portions of his prongs were seen above the
. surface. We again sat down on the bank for some minutes, pretendin-
to read a book. At length we suddenly directed our eyes towards hi.n
and raised our hand, when he rushed to the shore, and dashed through the'
rattling canebrake, in rapid style.
The food of the rominon Deer varies at difTerent periods of the year. In
wmter, it feeds on buds of several kinds of shrubs, such as the wild rose
the hawthorn, various species of bramble, {Rubux,) the winter green
{P'/rolo,) the Partridge Berry, {MilckcUa repens,) the Deer Leaf, {Hopea
tuictorm,) the bush Honeysuckle, (Azalea,) and many others. In sprino
and summer it subsists on tender grasses, being very select in its choice
I'i
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224
VIRGINIAN DEER.
hi-
PI1
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m^
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and dainty in its taste. At these seasons it frequently leaps fences, and
visits the fields of the plai.ter, talting an occasional bite at his young wheat
and oats, not overlooking the green corn, (Mtihr,) and givin^,' a decided
|)refer(Mi .> to a field planted with cow-peas, which it divests of its joiiii:^
jiods and tender leaves ; nor does it pass lightly by berries of nl, kinds,
such as the lluekleberry, Blackberry and 8!'>e, {Vihurniim piunifuliiim.)
We are informed by a fric^nd that in th*? vicinity of Nashville, (Tenesse«s)
ther(! is an extensive park containing about three hundred Deer, the prin-
cij)al food of wiiicli is the luxuriant Kentucky blue-grass, {Pun pratcnsis.)
In autumn it finds ii.i abundance of very choice food in the chestnuts, chin-
quepins and beech-nuts strewn over tlie ground. The localities of the
various oaks are resorted to, and we have seen its tracks most abundantly
under the Live Oak, {Qiicrciis firrns,) the acorns of which it appears to
prefer to all others. We once observed three deer fci,ding on these acorns,
surrounded by a flock of wild turkeys, all eagerly engaged in claiming
their share. The fruit of the Persimmon tree, after having been ripened
by t!u! frosts of winter, falls to the ground, and also becomes a favourite
food of the Deer.
Possessing such a choice of food, we might suppose this animal would
be always fat: this, however, is not the case, and, except at certain
seasons of the year, the Deer is rather poor. The bucks are always
in fine order from the month of August to November, when we have
seen some that were very fat. One which we killed weighed one
Imndred and seventy-five pounds. We have been informed that some
have reached consideranly over two hundred pounds. In November, and
sometimes a little earlier, the rutting season commences in Carolina, when
the neck of the buck begins to dilate to a large size. lie is now con-
stantly on foot, and nearly in a full run, in search of the does. On meet-
ing with other males, tremendous battles ensue, when, in some rare in-
stances, the weaker animal is gored to death ; generally, however, he flies
from the vanquisher, and follows him, crest (alien, at a respectful and
convenient distance, ready to turn on his heels and scamper off at the first
threat of his victorious rival. In these rencontres, the horns of the com-
batants sometimes become interlocked in such a manner that they cannot
be separated, and the pugnacious bucks are consigned to a lingering and
inevitable death by starvation. We have endeavoured to disengage these
horns, but found them so completely entwined that no skill or strength of
ours was successful. We have several times seen two, and on one occa-
sion, three pairs of horns thus interlocked, and ascertained that the .skulls
and skeletons of the Deer had always been found attached. These battles
only take place di'.iing the rutting season, when the horns are too firmly
VIRGINIAN DKER.
22A
attached to be separated from the skull. Indeed, we have seta d horn
shot «ir i,i the middle by a ball, whilst the stump still continued tirmly
seated . , the skull. The rutting .season continues about tw- months,
the largest and ol.lest does being enrliest sought for. and those of eighteen
moi;fh8 at a later perio.l. About the month of January, the bucks
drop their horns, when, as if conscious of having been .shorn of their
strength and honours, they seem humbled, and congr.^gate peaceably
with each other, seeking the concealment of the woods, until they can
once more present their proud antlers to the admiring herd. Immediately
aOer the rutting season, the bucks begin to grow lean. Their incessant
travclhng during (he period of vencry-their fierce battles with their
rivals, and the exhaustion consequent on shedding and replacing their
horns by a remarkably rapid growth, render them emaciated and feeble
for several months. About three weeks alter the old antlers have been
shed, the elevated knobs of tlie young horns make their appeara.ice.
I bey are at first soft and tender, eontaining numerous blood-vessels and
the slightest injury causes them to blee.l IVeely. They possess a conside-
rable degree of heat, grow rapidly, branch off into several ramifications
and gradually hard.n. They are covered with a soft, downy skin, and
are now in what is called " velvet." When the horns are fully grown
which IS usually in .Tuly or August, the buck shows a restless pronen.sity
to nd himself of the velvet covering, which has now lost its heat, and
become dry : hence he is constantly engaged in rubbing his horns against
bushes and saplings, often destroying the trees by wounding and tearing
the bark, and by twisting and breaking off the tops. The system of bony
development now ceases altogether, and the horns become smooth, hard,
and solid.
The does are fattest from November to January. They gradually get
thinner as the season of parturition approaches, and grow lean whilst
suckling their young.
The young are, in Carolina, produced in the month of April ; young
does, however, seldom yean till May or June. In the Northern States
they bring forth a little Inter, whilst in Florida and Texas the period is
earlier. It is a remarkable, but well ascertained fact, that in Alabama
and Florida, a majo.ity of the fawns are produced in November. The
doe conceals her young und, r t prostrate tree-top, or in a thick covert of
grass, visiting them occasioiK.iiy during the day, especially in the morn-
mg, evening, and at night. The young l-iwns, when only a few davs old.
are often found in ho sound a sleep that we have, on several occasions,
seen them taken up in the arms before they became conscious that they
were captives. They are easily domesticated, and attach themselves to
vf.t,, ft. — 29.
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22G
VIRGINIAN DEER.
their keepers in a few hours. A fric-^J possesses a young deer that,
when captured, during the last summer, was placed with a she goat,
which reared it, and the parties still live in habits of mutual attachment.
We have seen others reared by a cow. A goat, however, becomes the
best foster-mother. They breed in confinement, but we have found them
troublesome pets. A pair that we had for several years, were in the
habit of leaping into our study through the open window, and when the
sashes were down they still bounced through, carrying along with them
the shattered glasses. They also seemed to have imbibed a vitiated and
morbid taste, licked and gnawed the covers of our books, and created con-
fusion among our papers. No shrub in the garden, however valuable to
us, was sacred to them; they gnawed our carriage harness, and finally
pounced upon our young ducks and chickens, biting off their heads and
feet, leaving the body untouched.
The doe does not produce young until she is two years old, when she
has one fawn. If in good order, she has two the following year. A very
large and healthy doc often produces three, and we were present at Goose
Creek when an immense one, killed by J. W. Audubon, was ascertained,
on being opened, to contain four lat-ge and well formed fawns. The
average number of fawns in Carolina is two, and the cases where three
are produced are nearly as numerous as those in which young does pro-
duce only one at a birth.
The wild doe is attached to her young, and its bleat will soon bring her
to its side, if she is within hearing. The Indians use a stratagem, by
imitating the cry of the fawn, with a pipe made of a reed, to bring up
the mother, which is easily killed by their arrows. We have twice
observed the doe called up by this imitation of the voice of the young.
She is, however, so timid that she makes no eflbrt in defence of her cap-
tured offspring, and bounds off at the sight of man.
The common Deer is a gregarious animal, being found on our western
prairies in immense scattered herds of several hundred. After the
rutting season the males, as we have before stated, herd together and it is
only during the season of intercourse that both sexes are found in com-
pany. The does, however, although congregating during a considerable
portion of the year, are less gregarious than many species of African an-
telopes, the buffalo, or our domestic sheep; as they are found during the
summer separated from the rest of the gang or troop, and are only accom-
panied by their young.
The Deer is one of the most silent of animals, and scarcely possesses
any notes of recognition. The fawn has a gentle bleat that might be
heard by the keen ears of its mother at the distance probably of a hundred
VIRGINIAN DEER.
227
j'ards. We have never heard the voice of the female beyond a mere
murmur when calling her yoiins, except when shot, when she often bleats
loudly like a calf in pain. The buck wh^n suddenly started sometimes
utters a snort, and we have at night heard him emitting a shrill wliistliiig
sound, not unlike that of the chamois of the Alps, that could be
heard at the distance of half a mile. The keen sense of smr-ll the
Deer possess enables them to follow each other's tracks. We have ob-
served them smelling on the ground and thus following each other's
trail for miles. We were on an autumnal morning seated on a log
in the pine lands of Carolina when a doe came running past us. In the
course often minutes we observed a buck in pursuit, with his nose near
the ground, following in all the windings of her course. Half an hour
afterwards came a second buck, and during another interval a third small
buck pursued the same ^rail. The sense of sight appears imperfect— as
we have often, when standing still, perceived the Deer passing within a
few yards without observing us, but we have oiten noticed the alTrighted
start when we moved our position or when they scented us by the wind.
On one occasion we had tied our horse lor some time at a stand ;— on his
becoming restless we removed him to a distance— a Deer pursued by
dogs ran near the spot where the horse had originally stood, caught the
scent, started suddenly back, and passed within a few feet of the spot
where we were standing, without having observed us. Their sense of
hearing is as keen as that of smell. In crawling towards them in an open
wood, against the wind, you may approach within gun shot, but if you
unfortunately break a stick, or create a rustling among the leaves, they
start away in an instant.
This animal cannot exist without water, being obliged nightly to visit
some stream or spring for the purpose of drinking. During the present
year (1850) a general drought prevailed throughout our southern country.
On the Hunting Islands between Beaufort and Savannah, the Deer, we
were informed, nearly all perished in consequence of the streams or
these Islands having dried up. Deer are fond of salt, and like many
other wild animals resort instinctively to salt-liciis or saline springs.
The hunters, aware of this habit, watch at these " licks," as they are
called, and destroy vast numbers of them. W'; have visited some of these
pools, and seen the Deer resorting to them in the mornings and evenings
iuid by moon light. They did not appear to visit them lor the mere purpose
of drinkinsr. but after walking around the sides, commenced licking the
stones and the earth on the edges, preferrinj; in this manner to obtain this'
agreeable condiment, to taking a sudden draught and then retiring. On
the contrary they lingered lor half an !iour around the spring, inwl after
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228
VIRGINIAN DEER,
having strayed away for some distance, they often returned a second and
even a third time to scrape the sides of it, and renew the licking process.
Our common Deer may be said to be nocturnal in its habits, yet on the
prairies, or in situations where seldom disturbed, herds of Deer may be
seen feeding late in the morning and early in the afternoon. Their
time for rest, in such situations, is genpraiiy ihe middle of the day. In
the Atlantic States, where constantly molested by the hunters, they are
seldom seen after sunrise, and do not rise from their bed until the dusk of
the evening. The Deer is more frequently seen feeding in the day time
during spring and summer, than in winter; a rainy day, and snowy
wintery weather, also invite it to leave its uncomfortable hiding place
and indulge in its roaming habits. We have no doubt, that in localities
where Deer have been constantly hunted, they, from a sense of fear,
allow you to approach much nearer to their place of concealment than
-in situations where they are seldom disturbed. They continue lying
still, not because they are asleep or unaware of your approach, but because
they are afraid to expose themselves to view, and hope by close con-
cealment to be passed without being observed. We have seen them
lying with their hind legs drawn under them ready for a spring— their
ears pressed flat on the sides of the neck, and their eyes keenly watch-
ing every movement of the intruder. Under these circumstances your
only chance of success is to ride slowly around the animal as if he
was not observed, and suddenly (ire before he leaps from his bed.
This effect of fear, on your near approach, is not confined to our Deer;
it may be seen in the common partridge, the snipe, and other game
birds. Before being hunted, they are restless — are unwilling to assume
the crouching posture called setting, and rise at a distance from their
pursuers; but after having been a few times disturbed and shot at, they,
in the language of sportsmen, become tame, and permit themselves to be
nearly trodden on before they can be induced to rise ; this apparent
tameness is in reality wildness, and their squatting and hiding the effect
of terror to which they are prompted by an instinct of self-preservation.
The gait of this Deer is various. In walking it carries its head very
low, and pursues its course cautiously and silently, occasionally moving
its ears and whisking its tail ; the largest animal is usually the leader of
the herd, which travel in what is called Indian file, there seldom being
two abreast. Walking is the ordinary pace of the Deer unless frightened,
or in some state of excitement. When first started, without being much
Planned, it gives two or three springs, ali^rhting with apparent awk-
wardness on three feet — and immediately afterwards resting on the oppo-
site side, erecting its white tail and throwing it from side to side. A fe w
VIRGINIAN DEEH.
229
high bounds succeed, whilst the head is turned in every direction to enable
it to detect the cause of alarm. The leaps and high boundings of the
Deer are so graceful, that we have never witnessed them without excite-
ment and admiration. When, however, the Deer observes you before it is
routed from its bed, it bolts off with a rush, running low to the ground,
vyith its head and tail on a line with the body, and for a few hundred yards
rivalling the speed of a race horse. But this rattling pace cannot be kept
up for any length of time— after the first burst its speed slackens, it foams
at the mouth, and exhibits other evidences of fatigue. We have some-
times seen it overtaken and turned by an active rider in the open wood,
and under other favourable circumstances, and on one occasion a fat buck
was headed by a fearless driver, lashed with his whip, brought to bay,
and finally knocked in the head and taken without having been shot.
We have witnessed a few instances where a pack of hounds, after a four
hours' chase, succeeded in running down a Deer. These cases are, how ever,
rare, nor would we give any encouragement to this furious Sylvan race,
in which the horse and his mad rider are momentarily exposed to the
danger of a broken neck from the many holes in the pine lands. The Deer,
after an attempt at bringing it to bay, frequently succeeds in escaping
from the hunter and the hounds, by dashing into a swamp or crossing a
river, and even should it be captured, after a long chase the venison is
found to be insipid and of no value.
In riding through the woods at night in the vicinity of Deer, we have
often heard them stamp their feet, the bucks on such occasions giving a
loud snort, then bounding off for a few yards and again repeating the
stam.ping and snorting, which appear to be nocturnal habits.
Deer take the water freely, and swim with considerablo rapidity ; their
bodies are on such occasions submerged, th(>ir heads only being
visible above the surface. We have witnessed them crossing broad rivers
and swimming the distance of two miles. When thus under way, they
cleave the water with such celerity that a boat can scarcely overtake
them.
Along our southern sea-board the Deer, when fatigued by the hounds,
plunge into the surf and swim off for a mile or two, fioating or swim-
ming back with the returning tide, when they ascend the beach near the
same place where they entered the water.
As already remarked, the llesh of our common Deer is the best flavoured
and most easy of digestion of all tlH> spi^cics with which we are acquainted,
except the black-tailed Deer; it is superior to the Elk or Moose of our
country, or the red Deer or Roebuck of Eurojje. It is, however, only a
delicacy when it is fat, which is generally the case (Vnm the beginning of
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VIRGINIAN DEER.
In I
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August to the month of December. In Carolina, the haunch and loin
only are served up on the tiibles of the ])lanters, tlie shoulders and skin
are the perquisites of the driver, or negro huntsuian. The Indians eiit
every part of the Deer, not omitting the entrails and the contents of the
stomach — the latter many of the tribes devour raw, williout subjecting
them to any cooking or roasting process. It is stated, even by white men,
that the stomach, with all its half-digested ingredients, is very palatable.
Hunger and hardships seldom fail to give a zest to the appetite. Vege-
table food is scarce in the wilderness or on the prairies. The traveller
who has long been obliged to sleep in a tent and make his toilet in the
woods, soon becomes indilferent to the etiquette of civilized life, and does
not inquire whether his dish has been prepared according to the recipe of
the cookery-books. A Deer paunch contains a mixture of many ingre-
dients, picked up I'rom various shrubs, seeds, and grasses, and m;iy become
a sul)stitute for vegetables where the kitchen-garden has not yet been in-
troduced. According to a northern traveller (Lyon's Narrative, p. ~'l'i),
who referred, however, to another animal, the reindeer of our continent,
it is " acid and rather pungent, resembling a mixture of sorrel and radish
leaves," its smell like " I'resli brewer's grains." As we have never been
subjected to the necessity of testing the virtues of this primitive chowder,
we are unable to pronounce it a delicacy, find must leave the decision to
those who may be disposed to make the experiment.
The ca])ture of the common Deer exercised the ingenuity and patience
of the Indian, ages before the pale faces intruded on his hunting-grounds,
with their rifles, their horses, and hounds. lie combatted with the wolf
and the cougar for their share of the prey, leaving on our minds a melan-
choly impression of the near approach of the condition of savage life to
that of the brute creation. Dilferent modes of hunting were suggest-
ed by the peculiar face of the localities of the countrj', and the de-
grees of intelligence or native cunning of the several tribes. The bow
and arrow evi<lently must have been in ccmnnon use throughout the whole
length and breadth of our land, as the numerous arrow-heads still every
where turned up by the plough abundantly attest.
The Rein Deer, inhabiting the extensive, cold, and inhospitable regions
of the British possessions to the north of Quebec, were caught in snares
manufactured from the hide, and sometimes of the sinews, of the animal.
During the season of their annual migrations, rude fences of brusli-wood
were constructed, which were a mile or two apart at the entrance, nar-
rowing down to nearly a point at the other end, in which the snares were
placed, and at the termination of this "cul de sac" was erected a high
fence or pound, secured by stakes, stones, and other strong materials, in
VIRGINIAN DEER.
281
which the Deer that escapv^J from the snares were finally enclosed and
sliot with arrows. The common Deer, however, is more suspicious and
timid, and will seldom sufTer itself to be circumvented in this manner.
The American Rein Deer is also brought near to the hunter lying in wait
t)eliind tlu; concealment of a clump of bushes, or lt(!ap of stones, by the
waving of a small flag of cloth, or a deer's tail, wtiich, exciting its atten-
tion, it falls a saerilice to its curiosity. This stratagem is also successfully
practised on our western prong-horned Anlelope.
The ConnnoM Deer is frequently brought within bow-shot by the Indians
who call up the does, as we have already mentioned, by imitating, with a
pipe made of a reed, the bleating of the fawn, and also th(! bucks, by an
imitation of the shrill, whistling sound which they emit during the rutting
season. The wily savage often clothiis iiimself in the hide of a Deer,
with the horns and ears attached— imitating the walk and other actions
of the anim;il, by which means he is enabled to approach and almost
mingle with the lierd, and kill several with his arrows before they take
the alarm. Since the introduction of fire-arms, however, many trii)es of
Indians have laid aside the bow and arrow, and adopted the gun. The
traders who visit them, usuiilly supply them with an inferior article, and
we have never seen any considerable number of Indians expert in the use
of the rifle. The late Dr. Leitner informed us that the Florida Indian.s
Bcidom shot at a Deer beyond twentj'-five or thirty yards, exercising great
patience and caution before they ventured on firing ; the result, however,
under these favourable circumstances, was usually successful. W(! believe
the Indians of North America never used poisoned arrows in the destruc-
tion of game, like the natives of CaflTraria and other portions of Africa, or
the aborigines of Br.izil and the neighbouring regions of South America.
The white man conducts his hunting excursions in various modes suited
to his tastes and adapted to the nature of the country in which he resides.
In mountainous, rocky regions, where horses cannot be used with advan-
tage, he goes on foot, armed with a rifle, carries no dog, and seeks for
the Deer in such situations as his sagacity and experience suggest. He
either espies him in his bed, or silently steals upon him behind the covert
of the stem of a large tree whilst he is feeding, and leisurely takes a
steady and fatal aim. On the contrary, in situations adapted to riding,
where the woo<ls are thickly clothed with underbrush, where here and
there wide openings exist between briar-patches, and clumps of myrtle-
bushes, as in the Southern States, the Deer are almost universally chased
with hounds, a!id instead of the rifle, double-barrelled deer-guns, of
diflerent sizes, carrying from twelve to twenty buck-shot, are alone madc
Uhe of by the hunters.
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it.
232
VIRGINIAN DKKR.
It may not hv uiiiiitcrcstiiiy; to our rciidcrs ii' \vc point, out 1\h' dilTcrent
modes in wliicli Deer liiinis arc conducted.
In llic early scttlcni<>nl ol' onrcounlry
lore llicv accus
, when nuin Imutnd for food, and he-
toiued llieuiselves lo study tlieirease and couHort even in the
ciiase. "still liiuitin;,%" as it is termed, was universally ptaclised. 'I'Im!
wolves and oilier depreilatin^^ animals, l>y wlii<-li the colonists were siu'-
rounil(Ml, as well as l!ie proxiniily ol' hosiilo Indians almost, preolucUid
Iroin raisinii^ a snilicient, supply of slieep, l»o>?s, innl
lliem lor manv vears
poultry.
'riu" eullivatioii ol" a f^nia
II Held I'ui-nislied lliem with hread,
wh
Idle for uu-al tliev were cliielly dependent on the ^un. Hence ii portion
of their time was
from a kind of necessity devoted to the chase
'I'l
10
passi
we
an for lumtin:; seems however lo Im' inaale with many person.s, and
have observed thai il oflen rims in families and is transmilled lo their
posterity, as is knowuto he the case with the descendiints of the hunters m
ven now many persons in our country, who devote.
the .\l|
)S.
Thei
■e are t
Wt>t
•ks and months to tin- precarious cmi)loymcnl of Deer lumlinj;, when
half the iudnstrv ami faliuue ii\ re
rular labour would allord t'aeir families
everv m-cessary ami cond'ort. llnntinfi is a, ph-asant r<-cn-ation, hut a
very un
poverty.
l'\)r ^uccess in slill-huntini;- it is essen
tial that the individual who en-
giif^es in it, sliould he actpi
ainted with the almost imiH-nelrahle de|)ths ofihe
forest, as w<
the rille. possess a
to endure iireat fatiijuc
■11 as the habits of the Deer. He umsl be expert in the use. of
larj^e stock of patience, and be constitutionally Hda|)le,d
Before the dawn of dav, he Ireads the \m\hH
d.
to th
iiloni: which the animal strays in rcturninj;- from its na-litly rambles
covert usually its restin<i-plaee for ihe day. lie ascends an eh'valion, lo
ascertain whcliierhe may not observe the object of his s.-arch fcediiif; in
the vallie.s. If the patience and perseverance of the n»)rnin« are not at-
tended with .success, he seeks for the Deer in its bed— if il should be starl-
(ed l)v his stealthy tread and sprins; up, it stops foramonieni before bound-
uur awav. an(
1 thu>
illords him the chance of a, shot ; even if the animal
hould keep on its course without a pause, he iVeipn-ntly takes a running,
'I
or what is called a chance shot, and is often suceessfid.
There is anot
her mode of deer huntiufj; we saw practised many years
ay;o in the Western parts o
f Ihe Stale of New-York, which we ret^ard as
still more fatisiuinu;
unt'ortu.i.ite animal
to ihelumttM', and as an unfair advantage taken of tho
The parlies sally out on a deep snow, cove
I'h
rd by
crust, w hicii sometimes succeeds a rain during winter. 1 hey u.s(
light
and s(>ek the Deer in situations where in the manner of I ho
mouse of Nova Scotia, they hu\e trampled i)alhs through the snow it)
suov. -shoes
VIRGINIAN OEKIl.
28a
thf> virinifyof fl„, slirubs on whicli f,l„,y food. When started from those re-
tr.'i.ls ih.-y ar<^ lore.-d t<. phiiii,'.- iiKo thr. dr.-p snow ; imd hreakinj,' throutrJi
t\w. eru.M leave at every leap traces of hlo,.,! Cnmi their wounded le«s ;
thev are soon overtaken, sometimes hy(l(,>,'H, at other times hy the hunters,
who advance fastctr on their snow-shoes than th.^ exhausted Deer, which
'■•II an easy prey either to tlie Jinnler's knile or his ^un. In this manner
thousands olDeer were Ibrnierly niassaercul in th(! Northern States.
We have ascertained that our(!oirnnon Der-rniay he easily taken hy the
grey-hound. A pair of the hitter, introduced into Carolina hy Col. CATTKr,,
fn<pi<nlly caught them aft.^r a run ol' a few hundred yards. The Deer
w.'re trail(..! and started hy h(N-ij,'les-tli.- j^n-y-hounds Kenerally kept in
advance of them, makinf? hi-,di leaps in order to jjet a glimpse of the Deer
wliicli wer.-. soon overtaken, seized hy the throat, and thrown down. The
nature of the country, liowever, from its swamps and tfiick covers often pre-
v.Mit.^d tlie huntsmen from coming up to the captured animal before it was
lorn and mutilatcMl hy tla^ hounds, and many l).-er could not hr. found, as
the pack becomes sil.-nt assoon as the IhivA- is taken. We predict, however,
that this will bccom.. the favourite mod(! of taking Deer on the open wes
tern prairies, wlwtv. there an; no trcies orotluu- obstructions, and the whole
scene nuiy be; enacted within view of th(« hunters.
Some hunters, who are engaged in supplying the salt and red Sulphur
Springs of Virginia with venison during summer, practise a novel and an
erpially objectionable mode in capturing the Deer. A certain number of
very larg.; stcsel-traps made; by a blacksmith in the vicinity, are set at night
in the waters of dilierent streams at the crossing-plaoes of the Deer.
Thr. animal wlien thus captured instead of tearing off its hig by violent
struggles is said to remain standing still, as passive as a wolf when simi-
larly entrapped. Another and still more cruel mode is sometimes prac-
liod in the South : The Deer hav.- particular places where they leap the
fences to visit the pea-fu'lds ; a sharpcn(ul stake is placed on the inside of
the fence— the Deer in leaping over is perforatcul through tlie body by
this treaclierous spike, and is found either dead or dying on the following
morning. It is .also a frecjue-t practice in the South for the hunter during
clear nights to w.Icii a pea-field fre.piented by De,;r. To make sure of
thisgam^ :,e mounts some trei;, seats himself on a crotch or limb which is
above the current that would convey the* scent to the keen olfactories of
the; D(!er, and from this elevation leisurely waits for an opportunity to
make a sure slutt.
In some parts of th.. Northern and Middle States the Deer are captured
by the aid of boats. We observed this mode of hunting pursued at Sara-
toga and other lakes, and ascertained that it was frequently 'attended with
*!
Vol.. M
'.in.
f-
234
VIRGINIAN DEER.
success. The hounds are carried to the hills to trail, and start the Deei
before day light. Some of the hunters are stationed at their favourite cross-
ing places to shoot them should they approach within gun shot. After
being chased lor an hour or two the Deer pushes for the lake. Here
on some point of land a party lie in wait with a light and swift boat :
after the Deer has swam to a certain distance from the shore he is headed
and approached by the rowers, a noose is thrown over the head, and the un-
fortunate animal drawn to the side of the boat, when the cajjtors proceed
to cut its throat in violation of all the rules of legitimate sporting.
Fire hunting is another destructive mode of obtaining Deer. In this case
two persons are essential to success. A torch of resinous wood is carried
by one of the party, the other keeps immediately in front with his gun.
The astonished Deer instead of darting off seems dazzled by the light, and
stands gazing at this newly kindled flame in the forest. The hunter sees
liis eyes shining like two tapers before him ; he fires and is usually suc-
cessful ; sometimes there are several Deer in the gang, who start off for a
few rods at the report of the gun, and again turn their eyes to the light.
Ii' this manner two or three are frequently killed within fifty yards of each
other. This kind of hunting by firelight is often attended with danger
to the cattle that may be feeding in the vicinity, and is prohibited by a
law of Carolina, which is however frequently violated. The eyes of a
cow are easily mistaken for those of a deer. We conversed with a gentle-
man who informed us that he had never indulged in more than one fire-hunt,
and was then taught a lesson which cured liim of his passion for this kind
of amusement. He believed that he saw the eyes of a Deer and fired, the
animal bounded off, as he was convinced, mortally wounded. In the im-
mediate vioinit;; lie detected another pair of eyes and fired again. On re-
turning the next morning to look for his game, he found that he had slaugh-
tered two favourite colts. Another related an anecdote of a shot fired at
what was supposed to be the shining eyes of a Deer, and ascertained to his
horror hat it was a dog standing between the legs of a negro, who had
endeavoured to keep him quiet. The dog was killed and the negro slightly
wounded.
There is still another mode of Deer hunting which remains to be decrib-
ed. It is called "driving," and is the one in general practice, and the
favourite pastime among the hospitable planters of the Southern States.
We have at long intervals, occasionally joined in these hunts, and must ad-
mit that in the manner in which they were conducted, this method of Deer
hunting proved an exciting and very agreeable recreation. Although
we regret to state that it is pursued by some persons at all seasons of the
year, even when the animals are lean and the venison of no value, yet the
VIRGINIAN DEER.
235
more thoughful and judicious huntsmen are satisfied to permit the Deer to
rest and multiply for a season, and practice a little self-denial, durin- sum-
mer when the oppressive heats which usually prevail-tho danger of bein-
caught in heavy showers-and the annoyance of gauzefiies, mosquetoes'
and ticks, present serious drawbacks to its enjoyment. The most favour-
able season for this kind of amusement is from the beginning of October
to January. The Deer are then in fine order ; the heats of summer are
over ; the crops of rice gathered, and the value of the planter's crop can
be calculated. The autumn of the Southern States possesses a peculiar
charm ; high winds seldom prevail, and the air is soft and mellow ; al-
though many of the summer warblers have migrated farther to the south
yet they have been replaced by others : The blue-bird, cat-bird and
mocking-bird have not yet lost their song, and the swallows and night-
hawks are skimming through the air in irregular and scattered groups
on their way to the tropics. Vegetation has been checked, but not
sufficiently destroyed to give a wintry aspect to the landscape. The
Qpntums Gcrardias am] o^hemutumim] flowers are still disclosing a few
lingering blossoms and emitting their fragrance. The forest trees pre-
sent a peculiar and most striking appearance. A chemical process has
been going on among the leaves, since the first cool nights have sus-
pended the circulation, giving to those of the maple and sweet gum,
a bright scarlet hue, which contrasted with the yellow of the hickory,'
and the glossy green of the magnolia grandiflora, besides every shade of
colour that can be imagined, irndiM- an American forest, more striking
and beautiful than that of any other country. It is the season of the year
that invites to recreation and enjoyment. The planters have been separat-
ed dui-ing the summer ; some have travelled from home— others have re-
sided at their summer retreats ;— they are now returning to their planta-
tions, and the intercourse of the neitrhbourhood, that has been suspended
for a season, is renewed. We recall with satisfaction some past scenes of
pleasureable associations of this kind. The space already taken up by this
article will preclude us from entering into minute detfiil,and restrict us to
a few incidents which will present the general features of a Carolina Deer
hunt. We comply with the oft-repeated invitation to make our annual
visit to our early and long-tried friend Dr. Dnsi;,, at his hospitable residence
some twenty miles from the city, which his friends have named Liberty
flail. The mind requires an occasional relaxation as well as the body.
We have resolved to fly for a day or two, from the noise and turmoil of
the city— to leave books and cares behind us— to break off the train of
serious thought— to breathe the fresh country air, and mingle in the inno-
2ent sports of the field and the forest. Render, you wili go with us and
V ' , !
E^di
'2M
VIRGINIAN DEER.
enter into our feelings Jind enjoyments. \s we ap^proacli the long avenue
a mile t'mm the residence of the companion ol thirty-live years, we
are espied by his domestics who welcome us with a shout, and intbrin us
tliivt their " Hdss" is looking; out for us. Our friciKl soon perceives us, and
hurries to the jjate. Mow pU-asaiit arc the Kreetin>jsof friendship — the smil*
inj? look ol welcome, the open hand, and the warm heart of hospitality.
The usual invitation is sent to ji neij^hbdur. to lunch, ''ine, and meet a
friend. The evening is spent in sociitl cduverse and r:osed with the
family bible, and otlerings of gratitude and praise to theGiver of all good.
The sleep of him. who lias < caped from the din of tl i' city to tlie quiet
of the country, is always refreshing. The dawn of day invitr ; u.s to a
substantial breakfast. The parties now load their double-barrelled guns,
whilst the horses are being saddled. The horn i-i sounded, and the driver,
full of glee, collects his impatient hounds. The party is unexpectedly
augmented by several Welcome guests. Our intelligent friend Harris, from
New-Jersey, has come to Carolina, to be initiated into 'r mysteries of
Deer hunting. as a preparation to farther ex|doitson the Western praiiies,
among the elk and the buifalo ; with iiirn coiaes ArorBox, lli< Nestoi if
American ornithology, and his son, together with Ih. Wu.son. Alh-r the
first greetings areover, we hasten to ;-,iddle addii onal horses forthose ofoup
guests, who are disposed tojoin us, Tli old ornithologist, h iving no relish
for such boyish sports, s"illiesto the swanrps in search of some rare species
of woodpecker. We proceed to the drives, as fhey are called, viz., certain
woods, separated by old fields and various openings, in some parts of
which the Deer have their usual run, where the parties take their stands.
These drives are designated by particular names, and we are familiar
with Crane pond. Gum thicket, the Pasture, the Oak swamp, an 5 a number
of bays, one of which we would be willing to Ibrgef, tor there we missed
a Deer, and the bay was named after us, to our mortification. The driver
is mounted on a hardy, active, and sure-footed horse, that he may be
enabled to turn the course ol the Deer, ifhe attempts to run back, or to
stop the dosrs. We were carrii il round to our st uids by our host, when
a Deer bounced up before us; in an instant a loud report is heard waking
the echoes of the forest — the animal leaps high into tl :ir, and tumbles
to the ground. Thus, our venison is secured, and we carry on on • farther
operations from the mere love of sport. Anxious to give our friend II \rris
an opportunity of killing his I'rst Deer, we place him at the best stand.
Our mutual wishes are soon gratified. He is stationed at the edge
of a bay — a valley overgrown with bay-trees {Maifnolia glmii n) — which
from that day received the cognomen of Harris' bay. The hounds aftef
considerable trailing rouse two noble bucks, one of them bounds CT.t
VIRGINIAN DEER.
S87
near our friend. Ho is ohlisrfd fo be refidy in a moment, before the
Deer comes in the line with another hunt..r. At the report of his {?im wo
perceive that the buck is woutuh'd. "Miti.l," cries out (Viuiid VVii.so.v
"your shot have whistled past me." Friend H. crows pain at the tliougiit
of havin- endfu. .1 tlie life , another, but we comfort him by stating,
that his shot liad not reached within (ifty yards of the nervous hunter,
and moreover, thai >h,> old i,uek was womuled and would soon be his.'
"We observed where he had laid down in the grass, and was starled up
a^ain by the dogs. Now for a chase of a wounded buck. He takes
through an old fi.dd once planted with , otton. now full of ruts and ditches,
and grown up with tall broom-grass. We agree to h^t the boys have the
pleasure of the chase whilst we are the silent spectators. They bound
over ditches and old corn-ludds. (iring as they run. Suddenly the hounds
become silent, and then the loud sounding of the horn is heard ming-
led with the whoops of the hunters, which inform us, that the game
is se<-ured ; it proves fo be a majestic buck. The successful hunter is
now obliged to submit to the ordeal of all who have fleshed th«ir maid-
en sword, and killed their first D.-er. "I submit," he said good na-
turedly, " but spare my spectacles and whiskers." So his loieheadand
cheeks were crossed with the red blood of the buck, and the tail was
stuck in his cap. The hunt proceechnl merrily and successfully. Young
Audubon, however, had not yet obtained a shot. At length a Deer was start'^
ed near our host. He would not shoot it, but strove to drive it to his neigh-
bour. He ran after it, and shouted, stumbled over a root, and in the fall
threw oir his spectacles : but as he was groping for them among the
leaves, he ascertained that his generous eflbrts had been successful :
the Deer had been turned to Mr. Aijoiibon. One barrel snapped— then
came a sharp rep,, from the other— a loud whooj. su^'ceeded, and we
soon ascertained th, another Deer had fallen. We now conceived that
we had our wishes for a successful hunt fully gratified ; the dinner
hour had arrived. P^ive nobh Deer were strung upon the old pecan-
nut tree in sight of our festiv vll. The evening passed off in plea-
sant fonver.-ition -some of tnos. present displayed their wit and poet-
ical talents by givii,- the details of the hunt in an amusing ballad, which
however has not yet found its way into print. Thus ended a Carolin.a
Deer hunt.
We regret t. he obliged to state, that the Deer are rapidly disaj.^ -aring
from causes that ought not to exist. There are at present not one-
fifth of the number of Deer in Oarnlina that existed twen*\ years ago.
In the Northern and I\!iddle States, where the farms have been sub
divided, and the forRsi necessarilj cleared, the Deer havt disappeared
I !
^.-.
if
s. »'
i'
" >,"
288
VIRGINIAN DEER.
■! '^
I
t
because there was no cover to shelter them. In the Southern States,
however, where there are immc-iise swamps sub'cct to constant inun-
dations and pine barrens too poor lor cultivation, they wouhl rev ;ua
undiminished in numbers were it not for the hlle and cruel practi'- • ol
destroying; tlum by (irelijrht. and huntinj? them in the spring and sumincr
seasons by overseers and idlers. There is a law of the State fori ''n -
the killing of Deer during certain months in the year. It is, ho-vever.
never enforced, and Deer are exposed for sale in the markets of Char!e.,
ton and Savannah at all seasons. In some neishbourhoods, wii^.o
they were formerly abundant, now none exist, and the planters have
given up their hounds. In New-.Iersey and Long Island, where tlie game
laws are strictly enforced. Deer are said to be on the increase. In
some parts of Carolina, where the woods are enclosed with fences, not
sufficiently high to prevent the Deer from straying out, but sufficient to
prevent the hunters from persecuting them in summer, they have greatly
multiplied and stocked the surrounding neighbourhoods. If Judicious
laws were framed and strictly enforced the Deer could be preserved for
ages in all our Southern States, and we cannot refrain from submitting
this subject to the consideration of our southern legislators.
GEOGRAPFUCAI, DISTRIBUTION.
. This animal is found in the State of Maine ; north of this it is replaced
by larger species, the moose and reindeer. It exists sparingly in Upper
Canada. In all the Atlantic States it is still found, although in diminish-
ed numbers. Where care has been used to prevent its being hunted at
unseasonable periods of the year, as in New- York and New-Jersey, it
is said to be rather on the increase. In the mountainous portions of
Virginia it is hunted with success. It is still rather common in North
and South Carolina, Georgia and Florida, especially in barren or swampy
regions, of which vast tracts remain uncultivated. In Mississippi, Mis-
souri, Arkansas, and Texas, it supplies many of the less industrious in-
habitants with a considerable portion of their ftrod. It is very abundant
in Texas and New Mexico, and is a common species in the northern parts
of Mexico. We cannot say with confidence that it exists in Oregon,
and in California it is replaced by the black tailed Deer. — C.llichardsonii.
GENERAL REMARK9.
This species has been given under different names, and we might have
added a long list of synonymes. The specimens we saw in Maine and
VIROINIAN DEER.
239
at N., «ara were nearly double the s.ze of those on the hunting islands
.n Sou.h Carohna. The Deer that reside permanently in the swan,,s oi
Caroma are taller and longer legged than those in the higher grounds
I he deer of the mountains are larger than those on the sea-board, yet these
diirerences. the result of food or climate, will not warrant ur in multiply,
ing them into dilferent species.
nil-
240
i . t
CAN IS LUPU S.— Linn . V ar. Rufls.
Red Texan Wolf.
PLATE L X X X 1 1,— Malb.
C. Colore supra inter fulvum nigrum variante, subtur dilutior ; cauda
apice nigro.
CHARACTEES.
Varied with red and black above, lighter beneath. End of tail black.
DESCRIPTION.
In shape the Red Texan Wolf resennbles the common graj' variety'. It
iri more slender and lighter than the white Wolf of the North West, and
has a more cunning fox-like appearance. The hairs on the body are not
woolly like those of the latter but lie smooth and flat. Its body and legs
are .ong, nose po'nted, and ears erect.
COLOUR.
The body above is reddish-brown mixed up with irregular patches of
black ; the shorter hairs being light yellowish-brown at the roots, deep-
ening into reddiish at the tips ; many of the longer hairs interspersed are
black from the roots through their whole extent. Nose, outer surface of
ears, neck, and legs, chestnut-brown, a shade paler on the under surface.
There is a brown ' ;,e on the fore-legs extending from the shoulders to
near the pn* . Moustaches few and black ; inner surfaces of ears soil-
ed-white; nails black ; along the upper lip, under the chin, and on the
throat, grayish-white. Upper surface and end of tail, as well as a broad
band across the middle portion, black.
DIMENSIONS.
From point of nose to root of tail,
Tail,
Ft tncl.us.
2 li
1 1
RED TEXAN WOLF.
341
HABITS.
This variety is by no means the only one found in Texas, where
Wolves, black, white and gray, are to be met with from time to time
We do not think, however, that this Red Wolf is an inhabitant of the
more northerly prairies, or even of the lower Mississippi bottoms, and
h.ive, therefore, called him the Red Texan Wolf.
The habits of this variety are nearly similar to those of the black and
the white Wolf, which we have already described, differing somewhat
owmg to local causes, but showing the same sneaking, cowardly, yet
ferocious disposition.
It is said that when visitin? battle-fields in Mexico, the Wolves preferred
the slain Texans or Americans, to the Mexicans, and only ate the bodies
ot the latter from necessity, as owing to the quantity of pepper used by
tiie Mexicans in their food, their flesh is impregnated with that powerful
stimulant. Not vouching for this story, however, the fact is well known
that these animals follow the movements of armies, or at least are always
at hand to prey upon the slain before their comrades can give them a sol-
dier's burial, or even after that mournful rite ; and if anything cou'ld in-
crease the horrors displayed by the gory ensanguined field, where man has
slain his fellows by thousands, it would be the presence of packs of these
ravenous beasts disputing for the carcasses of the brave, the young, and
the patriotic, who have fallen for their country's honour !
No corpse of wounded straggler from his troop, or of unfortunate travel-
ler, butchered by Camanches, is ever " neglected" by the prowling Wolf,
and he quarrels in his fierce hunger in his turn over the victim of similar
violent passions exhibited by man !
The Wolf is met on the prairies from time to time as the traveller slowly
winds his way. We will here give an extract from the journal kept by
J. W. Audubon while in Texas, which shows the audacity of this animal,
and gives us a little bit of an adventure with a uungry one, related by
Powell, one of the gallant Texan Rangers.
" Like all travellers, the ranger rides over the wide prairie in long
■silences of either deep thought or listless musings. I have never been able
to decide which ; but when, riding by the side of Walker or Havs, who
would like to say that a vacant mind was ever in the broad brow or be-
hind the sparkling eye either of him with the gray, or of him with the
brown ? but at times when watching closely I have thought I could trace
in the varying expression, castle after castle mounting higher and higher,
till a creek ' to water at,' or a deer which had been sound asleep and to
VOL. i[. — 31
- -omirn gB Mn
242
RED TEXAN WOLF,
windward of us, started some 30 or 40 yards off our path to wake up tho
dreamers of our party. No one is certain that liis queries will be wel-
come to the backwoodsman on a march through a strange country, any
more than would be those of a passenger, put to the captain of a vessel as ho
leans over the weather-rail looking what the wind will be, or thinking of
the disagreeable bustle he will have, when he gets into port, compared
to his lazy luxury on shipboard : but as I rode by the side of Powell we
started no deer, nor came to a ' water hole,' but a Red Wolf jumped up
some two or three hundred yards from us, and took to the lazy gallop so
common to this species ; ' Run you ,' cried Powell, and he sent a
yell after him that would have done credit to red or white man for its
shrill and startlinir effect, the Wolf's tail dropped lower than usual, and
now it would ha-t taken a racer to have overtaken him in a mile ; a
laugli from Powell, and another yell, which as the sound reached the Wolf
made him Jump again, and Powell turned to me with a chuckle, and
said, ' 1 had the nicest trick played me by one of those rascals you ever
heard of.' The simple, how was it, or let's have it, was all that he wanted,
and he began at the beginning. 'I was out on a survey about 15 miles
west of Austin, in a range that we dkln't care about shooting in any more
than we could help, for the Camanches were all over the country ; and
having 1 Hied a deer in the morninj^, I took the ribs off one side and wrap-
ping tluan in a piece of the skin, tied *♦ <o my saddle and carried it all day,
. J as to have a supper at night without i, .of ing ibr it ; it was a dark, dismal
day, and I was cold and hungry when I got to where I was to camp to wait
for the rest of the party to come up next day ; I made my fire, untied my
precious parcel, for it was now dark, with two sticks put up my ribs
to roast, and walked off to rub down and secu*e my horse, while they
were cooking ; but in the midst of my arrangement l incArd a stick crack,
and as that in an Indian country means something, i turrsed and saw, to
my amazement, fori thought no animal would go near the lire, a large
Red Wolf actually stealing 'my ribs' as they roasted ; insiinct made me
draw a pistol and ' let drivti' at him ; the smoke came in my face and I saw
nothing but that my whole supper was gone. So not in the most
philosophical manner I lay down, supperless, on my blanket; at dayliglit
1 was up to look out for breakfast, and to my surprise, my half-eooked ribs
lay within twenty feet of the lire, and the Wolf about twenty yard« off,
dead ; my l)all having been as well aimed as if in broad daylight."
We have represented a fine specimen of this Wolf, on a sand-bar. snuff-
ing at the b.meof a buffalo, which, alas ! is the only fragment of " ani-
mal mutter" he has in prospect for breakfast.
RED TEXAN WOLF
243
OEOGRAPrilCAL UfSTRlBUTION.
In all species of quadrupeds that are widely diffused over our conti-
nent, it has often appeared to us that toward the north they are more
sub)^ ;t to become wl.ite-toward the easi, or Atlantic side gray-to the
sout^ Wack-an,l towar.l the west red. The gray squirrel, (S. nugratorins),
of the Northern an.l Eastern States presents many varieties of red as we
proceed westwardiy towards Ohio. In the south, the fox squirrel in
the maritime districts is black as w(Ul as gray, but not re<l. On proceed-
ing westwardiy, however, through Georgia and Alabama.a great many ar->
found of a rufous colour. In Louisiana, there are in the southern parts two
species permanently black as well as the foxsquirrel, which in about half
the specimens are found black, and the re.nainder reddish. The same may
be said in regard to the Wolves. In the north there is a tendency towards
white-hence great numbers are of that colour. Along the Atlantic
coast, in the Middle and Northern States, the majority are gray. / To the
south, ni Florida, the prevailing colour is black, and in Texas and the south-
west the colour is generally reddish. It is difficult to account, on any
principles of science, for this remarkable peculiarity, which forms a sub-
ject of curious speculation.
This variety of Wolf is traced from the northern parts of the State of
Arkansas, southerly through Texas into Mexico ; we are not informed of
its southern limits.
GENERAL REMARKS.
The Wolves present so many shades of colour that we have not ventur-
cd to regard this as a distinct species ; ,nore especially as it breeds with
those of other colours, gangs of Wolves being seen, :n which this variety
is mixed up with both the gray and black.
244
GENUS LAGOMYS.— Geoff.
DENTAL FORMULA.
%^2 &— 8
Incisive — Canine — ; Molar — = 26,
Teeth and toes similar to those of the genus Lepus, upper incisors iti
pairs, two in front and two immediately behind them, the former large and
the latter small.
Ears moderate ; eyes, round ; hind legs not much longer than fore legs :
fur under the feet ; no tail ; m'lmmoe four or six ; clavicles nearly perfect.
Native of cold and Alpine regions. They lay up stores for winter pro-
vision which is never done by the true hares. They have a call-note resem-
bling that of some species of Tamice,
The name of this sub-genus, Lagomys; is derived from the Greek words
*«'/»(, {logos), a Hare, and /u/t, {mus), a Mouse.
Four species of this genus are described ; one, tht, Pika, exists in the
northern mountains of the Old World, one in Mongolian Tartary, one in
the south eastern parts of Russia, and one in the Rocky Mountains of North
America.
LAGOMYS PRINC EPS. —Richardson.
Little-Chief IIare.
PLATE LXXXIIL— Males.
L. Ecaudatus, fuscus, latere pallidior, subtus griseus, capite brevi ; auri-
culis rotundatis.
CHARACTERS.
Taillesa ; colour blackish brown, beneath gray ; head short and thick ; ears
rounded.
ors III
?e and
; legs :
erfect.
3r pro-
resem-
words
in the
one in
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LITTLE-CHIEF HARE.
245
8YNONYME8.
Lepub (Laoomys Prinoeps).
Rich. Fauna B. Ain. p. 227.
Fischer's Mamaliutn. p. 503.
DESCRIPTION.
"On comparing the skull of this animal with that of a true Hare,
there appears a larger cavity in proportion to its size, for the reception ol
the brain. The breadth of the skull, too, behind, is increased by very large
and spongy processes. The bone anterior to thr orbit is not cribriibrm
as in the Hares, although it is thin, and there is no depression of the frontal
bone between the orbits.
The upper anterior incisors are marked with a deep furrow near their
anterior margins, and have cutting edges which present conjointly three
well m .'ked points, the middle one of which is common to both teeth, and
is shorter than the exterior one. These incisiors are much thinner than
the incisors of the Hare, and are scooped out like a gouge behind. The
small round posterior or accessary upper incisors, have flat summits. The
lower incisors are thinner than those of the Hares, and are chamfered away
toward their summits, more in the form of a gouge than like the chisel-shap-
ed-edge of the incisors of a Hare.
Grinders. — The upper grinders are not very dissimilar to those of the
Hare, on the crowns, but the transverse plates of enamel are more distinct.
They differ in each tooth having a very deep furrow on its inner side,
which separates the folds of enamel. This furrow is nearly obsolete in the
Hares, whilst in the lagomys it is as conspicuous as the separation betwixt
the teeth. The small posterior grinder which exists in the upper jaw of
the adult Hare is entirely wanting in the different specimens of the Little-
Chief Hare which I have examined. The lower grinders, from the depths of
their lateral grooves, have at first sight a greater resemblance to the grind-
ers of some animal belonging to the genus Arvicola than those of a Hare ;
their crowns exhibit a single series of acute-triangles with hollow areas.
The first grinder has three not very deep grooves on a side, and is not so
unlike the corresponding tooth of a Hare as those which succeed it. The
second, third, and fourth, have each a groove in both sides so deep as nearly
to divide the tooth, and each of the crowns exhibits two triangular folds of
enamel. The posterior grinder forms only one tnaiigle." — (Richardson).
In size this species is a little smaller than the alpine /nViw of Siberia. The
ears are ovate, and do not appear to have any incurvations on their inner
margins. The eyes are small, re.sembling those of the arvicoluB ; there is a
marked prominent tubercle at the root of each claw.
_.^^.
LITTLE-CHIEF HAUR.
OOLOUB
The Little-Chief Hare is, on the upper ii<' dark brown, varied with
irregular bands of brownish-black runniiiL )m rlie sides aero the ' ek.
There are slight variations in diftV' nt specimc s, some havitr
blackish markings more distinct than )th( s. The lur is, for thrie-founris
of its length, of <a grayish-black colour, then partly yellowish-brown and
white; on the sides of the head and fore shoulders thi- llowish-brown
colour prevails more than in other parts. The ears a bordered with
white ; the whole under surface is yellowish-gray, and the small pro-
tuberance, which represents the tail, light coloured.
DIMENSIONS.
Incht
Length of head and body -
-
- 0^
" from nose to
eye -
-
■ - i
-
f
Fur on the back
-
-
■ - 1
-
-
• - 2i
Height of ear
-
-
1
Length of heel -
• •
HABITS
■ - H
Little is known with regard to the habits of this animal.
The following extract is made from the Fauna Boreali Americana:
"Mr. Dbummond informs me, that the Little-Chief Ilare frequents
heaps of loose stones, through the interstices of which it makes its way
with great facility. It is often seen at sunset, mounted on a stone, and
calling to its mate by a peculiar shrill whistle. On the approach of man,
it utters a feeble cry, like the squeak of a rabbit when hurt, and instantly
disappears, to reappear in a minute or two, at the distance of twenty or
thirty yards, if the object of its apprehension remains stationary. On the
least movement of the intruder, it instantly conceals itself again, repeating
its cry of fear ; which, when there are several of the animals in the neigh-
bourhood, is passed from one to the other. Mr. Dbummond describes their
cry as very deceptive, and as appearing to come from an animal at a
great distance, whilst in fact the little creature is close at hand ; and if
seated on a grey limestone rock, is so similar, that it can scarcely be
discovered. These animals feed on vegetables. Mr. Dbummond never
I
LITTLE-CHIEF llARE.
247
found their burrows, and he thinks they do not make any, but that they
construct their nests among the stones. He does not know whether the>
store up h!.v tor winter - not, but is certain, that they "do not come
To the above account, d affords us pleasure to annex the extract of a
letter, which we received from Mr. Nuttall on the same subject.
Of tills curious species of Lepus, (L. princcps of IIiciiarumjn), we werp
not fortunate enough to obtain any good specimens. I found its range to
be in that latitude {12°) almost entirely alpine. I rirst discovered it by
its peculiar cry, far up the mountain of the dividing ridge between the
waters of the Columbia and Colorado, and the Missouri, hiding amongst
loose piles of rocks, such as you generally see beneath broken clifTs.
From this retreat I heard a slender, but very distinct bleat, so like that
of a young kid or goat, that I at first concluded it to be such a cull ; but
in vain trying to discover any large animal around me, at length I may
almost literally say, the mountain brought forth nothing much larger than
a mouse, as I discovered that this little animal was the real author of this
unexpected note."
GEOGRAPHICAL DISTRIBUTION.
Dr. Richardson states, that this animal inhabits the Rocky Mountains
from latitude 52° to (iO° The specimen of Mr. Townbend was procured
in latitude 42°, and therefore within the limits of the United States.
GENERAL REMARKS.
Until recently it was not supposed, that we had in America any species
of this genus. We have compared it with the Pika, {Lagomys alpinits),
ol the Eastern continent, described by Pallas. Our animal is not only
of smaller size, but diflers from it in the formation of the skull and several
other particulars.
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248
SPERMOPHILUS FRANKLINII.— Sabink.
Franklin's Marmot Souirrel.
PLATE LXXXIV.— Male and Female.
S. corpore super cervino ferrugineave creberrim6 nigro maculate subter
albido, vultu ex nigro canescenti, Cauda elongata cylindricd pilis albis
nigro ter quatorve torquatis vestita.
characters.
Cheek pouches, tht. upper surface of the body spotted thickly with
black, on a yellowish-brown ground, under surface grayish-white ; face
black and white, intimately and equally mixed ; tail long, cylindrical, and
clothed with hairs which are ringed alternately with black and white.
SYNONYMES.
Arotomys Franhxinii. Sabine. Llnnean Transactions, Vol. 13, p. 19.
« •• Fi .uklin's Journey, p. 6G2.
" " Harlan's Fauna, p. 167.
•• •* Godman, Nat. Hist. Vol. 2d p. i09.
«* •• Richardson, F. B. Am. p. 108. pi. 12.
DESCRIPTION.
Franklin's Marmot is about the size of the Carolina Gray Squirrel, and
resembles it in form, its ears however are shorter, and its tail, which is
narrower, presents a less distichous appearance. The ears have an erect
rounded flap, and although not as large as those of S. Douglassii, are pro-
minent, rising above the fur considerably more than those of S, Richard-
sonii or <S. Annulatus. The body is rather slender for this genus ; eyes
large and rather pi eminent; cheek pouches small; moustaches few
and short.
The legs are shorter than those of the squirrels, and stouter than those
of S. Annulatus. The thumb has one joint, with a small nail ; the
second toe from the inside is the longest ; the palms arr naked. The
soles of the hind feet are hairy fi. r about two-thirds of their length from
SPERMOPHILUS FRANKLINU.
249
the heels. The claws are nearly straight being much less hooked than
those of iSf. Annulatus.
The hair is rather coarse, and the under fur not v^ry dense.
The tail is clothed with hair, but has on it no under fur. It is capable
of a somewhat distichous arrangement, but as we are informed by Sir
.foHN UicHARnsoN, whcn this animal is pursued, the tail is cylindrical, the
hairs standing out in every direct on. The hind feet, whei\ stretched out,
reach to the middle of the tail.
COLOUR.
Incisors orange ; eyes and whiskers, black ; nails, dark-brown ; the
septum and naked margins of the nostrils, and margins of the lips are
of a light flesh-colour ; eyelids, white ; below the nostrils, sides of face,
chin, and throat, yellowish-white. Upper parts of the head to beyond
the ears and neck, light brindled- gray, composed of blackish hairs tipped
with white, without any admixture of brown. The hairs on the back,
are at the roots, plumbeous, then brown, succeeded by aline of black, and
finally tipped with brown, giving it on the back a brownish-speckled
appearance. On the chest and inner surfaces of legs white, with a
slight brownish tinge. The hairs on the tail are barred with black a.nd
white ; they are light-coloured at the roots, then twice barred with
black and white, and broadly tipped with white, '''owards the extre-
mity of the tail there is a broader black bar, the apical portion being
white. When the tail is distichously arranged it presents two indis-
tinct longitudinal stripes of black.
DIMENSIONB.
From point of nose to insertion of tail.
Tail (vertebrfe), ....
To end of hair, ....
From heel fo end of middle claw, -
Height of ear, - . . .
HABITS.
9|
4f
2
i
We possess but little information of the habits of several of the Spermo-
phili of America. None of the species are found in the settled portions of
our country, whore opportunities are afforded the naturalist to observe
and note down their habits ; every one has undoubtedly an interesting
history attached to its life, which yet remains to be collected and written.
VOL. n. — ;j-2.
I
250
SPERMOPHILUS FRANKLINII.
Richardson observes of this species, that it lives in burrows in the sandy
soil amongst the little thickets of brushwood that skirt the plains. That
it is about three weeks later in its appearance in the spring than the
Arctomi/s Richardnonii, probably from the snow lying longer on the shady
places it inhabits, than on the open plains frequented by the latter. It
runs on the ground with considerable rapidity, but has not been seen to
ascend trees. It has a louder and harsher voice than the A. Richard sonii,
more resembling that of Sciurus Hudsonius when terrified. Its food con-
sists principally of the seeds of liguminous plants, which it can procure in
considerable quantity as soon as the snow melts and exposes the crop of
the preceding year. Mr. Townsend, who observed it in Oregon, does not
refer particularly to any habit differing from the above.
GEOGRAPHICAL DISTRIBUTION.
This is a northern and western species ; Dr. Richardson having ob-
tained it in the neighbourhood of Carlton House, and Townsend near the
Columbia River.
GENERAL RtMARKS.
Although several different Spermophiles bear a strong resemblance to
each other, we have not observed that this species has as yet been mis-
taken lor any other, and it has as far as we can ascertain retained its
name without change in the works of all new describers.
251
I'
1 (
GENUS MERIONES.-lLLrGEH.
Inch
9
sive - ;
s
DENTAL FORMULA.
C—
Canine — ; Molar— = 16
0-0 3_3
Cheek-teeth tuberculous, the first with three, the second with two,
and the third with one, tubercle.
Nose sharp, ears moderate; fore-feet short, with the rudiment of a
thumb; hind legs long, terminated by five toes with nails, each with a
distinct metatarsus. Tail, very long and slender ; mammJE. from two to
four pectoral, and from tv^o to four abdominal.
Habits nocturnal, many hibernate.
There have been eleven species described as belonging to this genus,
as it is now restricted ; one well determined species has been discovered
in North America, the rest are found in sandy and elevated regions, in
parts of Asia and A frica.
The word Meriones is derived from the Gr. w«, {merion), the thigh.
MERIONES IIUDSONICUS.-ZiMMERMAM.
JuMpiNo Mouse.
PLATE LXXXV.-Male and Female.
M. Supra saturate fuscus, infra albus, lincS laterali flava inter colorem
fuscom albumque intermedia ; caudS corpore iongiore.
CHARACTERS,
Dark reddish.hrownahnoe, with white underneath ; sidex yellow, separating
the colours of the back from the white beneath ; tail much longer than the body.
SYNONVMES.
Dipcs HuDsoNicus. Zimmerman. Geogr. Geschich., II. p.
Amekicanuh. Barton, Am. IMiil. Trans., 4. vol. p. 358—282. A. D. 1788
OANAnBNsis. Davies' Linn. Trans,, 4. 155.
11,1
■- lUPi
tl, i
i i ■ i
i I
252
JUMPING MOUSE.
Oerhillk do Canada. Desm. Mammal., p. 132.
" l*''- Ciivicr in Diet, des So. Nat., 18. p. 464.
Meriones Labradorius. Sabine, Franklin's Journ., p. i:,b and 157.
" Godnian, vol. 2. p. 94 and 97.
Meriones Labradorius. Richardson, Fau. Hore. Am., p, 144.
" Americanus. De Kay. Nat. Hist. N. Y., p. 71. pi. XXIV., fig. 2d,
DE.'SCRIPTrON.
Head, narrow and conical. Nose, tolerably sharp, with an obtuse tip
projecting a little beyond the incisors. Nostrils small, facing sideways
and protected anteriorly by a slight ventricose arching of their naked
inner margins. The mouth is small and far back. Whiskers, long,
extending to the shoulder ; eyes, small ; ears, semi-oval, rounded at
the tips, clothed on both surfaces with short hair. Fore feet small, nail in
place of a thumb ; hind legs long and slender ; there are five hind-toes,
each with a long slender tarsal bone ; the toes, when expanded, res-embling
those of some species of birds. The soles are naked to the heels ; upper
surface of hind-feet covered with short adpressed hairs ; tail, long, ."^caly,
has a velvety appearance, soft to the touch, is thinly covered with such
soft short hairs, that without a close examination it would appear naked.
The hair on the body is of moderate fineness, and lies smooth and
compact.
COLOUR.
Upper surface of nose, forehead, neck, ears, and a broad line on tim
back, dark-brown ; the hairs being plumbeous at their roots, tipped with
yellowish-brown and black ; under the nose, along the sides of the face
outer surface of the legs, and along the sides, yellowish ; lips, chin, and'
all the under surface white ; as is also the under surface of the tail in some
specimens, though in others brownish-white. The colours between the
back and sides, as well as bcaveen the sides and belly, are in most speci-
mens separated by a dislinct line of demarcation. This species is subject
to considerable variations in colour. We have seen some young ani-
mals, in which the dark reddish-brown stripe along the back was wholly
wanting ; others where the line of demarcation between the colours was
very indistinct ; nearly all are pure white on the under surface ; but we
possess two specimens that are tinged on those parts with a yellowish
hue.
JUMPING MOUSE.
253
DIMENSIONS.
Lenj^t h of head and body -
do of tail
Height of ear posteriorly -
From heel to longest nail -
Inches.
i
If
HABITS.
This species was familar to us in early life, and we possessed many op.
portumties of studying its peculiar and very interesting habits. We doubt
whether there is any quadruped in the world of its size, that can make its
way over the ground as rapidly, or one that can in an open space so quickly
evade the grasp .fits pursuers. The ploughman in the Northern and Mid'-
dle .States, sometimes turns up this species from under a clod of e.rth
when It immediately commences its long leaps. lie drops his reins and
hurries alter it ; whilst the little creature darts off with grfeat agility pursu-
ing an irregular zig-zag direction, and it requires an active runner' 'to keep
pace with It, as it alternately rises and sinks lika the llving-fish at sea and
ere the pursuer is aware, is out of sight, hidden probably behind some clod
or concealed under a tuft of grass. We have frequenUy seen these mic'
start from small stacks of wheat, where the bundles had been tempo-
rarily collected previous to their being removed to the barn. In such
cases they usually effect their escape among the grass and stubble
A rapid movement seems natural to this animal, and is often exhi-
bited when it ,s not under the induence of fear, and apparently for
mere amusement. Our kind Iriend Maj. Le Contf., now of New- York
informs us, that he has seen it in former times, near the northern end
of the^ Island of New- York, springing from the ground and passing
with the velocity of a bird, until its momentum being exhausted it dis^
appeared in the tall grass, apparently with ease and grace, again sprin-^.
mg forth m the same manner. It must not, however, from hence be
believed that the .Tumping Mouse walks on its hind H-ct only, and procuresses
at all times by leaps, without using its fore-.'eet. We havj frequentry seen
It walking leisurely on all its feet, in the manner of the white-footed
mouse. It is chiedy when alarmed, or on sp.dal occasions, that it makes
these unusual leaps; the construction of the body proves that this species
could not for any length of time be sustained on its tarsi. In its leaps
we have always observed that it falls on all its four feet.
We experienced no difficulty in capturing thi. species in box-traps, and
■' 'ii
«j
254
JUMPING MOUSE..
preserved a female in a cage from spring to autumn ; she produced ax
young a few days after bring caught ; she reared both of them, and
they had become nearly of full size before autumn, when by some accident
our pets escaped. We placed a foot of earth at the bottom of the cage,
in this they formed a burrow with two outlets. They used their feet and
nails to advantage, as we observed them bury themselves in the earth,
in a very short time. They were usually very silent, but when we
placed a common mouse in the cage, squeaked with a loud chattering
noise, like some young bird in pain. They skipped about the cage, wer^
anxious to make their escape from the mouse, and convinced us that thh
species is very timid. They were in their habits strictly nocturnal, scarcely
ever coming out of their holes during the day, but rattling about the
wires of the cage throughout the night.
Weobserv-d that every thing that was put into their cage, however
great might be the quantity, was stored away in their holes before the
next morning. We fed them on wheat, maize, and buckwheat. They
gave the preference to the latter, and we observed that when they had
filled their store-house with a quart of buckwheat, they immediately form-
ed a new burrow in which they deposited the surplus.
We are inclined to believe that this species produces several times dur-
ing the summer, as we have seen the young on several occasions in May
and August ; They are from two to four ; we have usually found three.
The fact of the females being frequently seen -vith the young attached to
their teats, carrying them along in their flight when disturbed, is well
ascertained. We have also observed this in several other species ; in the
white-footed mouse, the Florida rat, and even the common flying squirrel.
We are not, however, to argue from this that the young immediately after
birth become attached to the teats in the manner of the young opo'ssoms.
and are incapable of relaxing their hold ; on the contrary the female we
had in confinement, only dragged her young along with her, when she was
suddenly disturbed, and when in the act of giving suck ; but when she
came out, of her own accord, we observed that she had reliev..d herself from
this incumbrance. This was also the case with the other species refer-
red to.
Dr. Dekay, regards it as a matter of course that in its long leaps, it is
aidcL by the tail. We doubt whether the tail i;, used in the manner of the
kangaru ; the under surface of it is never worn in the slightest manner,
and exhibit.- no evidence of its having been used as a propeller. Its long
heel and peculiarly long slender tarsal bones on each toe, seem in them°-
sclves sufficieni to produce those very long leaps. We have often watch-
ed this species, and although it moves with such celerity as to render an
JUMPING MOUSE.
S56
examination very difficult, we have been able to decide, as we think, that
the tail is not used by the animal in its surprising leaps and rapid move-
ments.
The domicilof the Junsping Mouse in summer, in which her young are
produced, we have always (bund near the surface, .seldom more than six
inches under ground, sometimes under fences and brushwood, but more
generally under clods of earth, where the sward had been turned over in
early spring, leaving hollow spaces beneath, convenient for the summer
residence of the animal. The nest is composed of tine grass, mixed with
which we have sometimes seen feathers, wool, and hair.
We are, however, under an impression that the Jumping Mouse in winter
resorts to a burrow situated much deeper in the earth, and beyond the in-
fluence of severe frosts, as when fields were ploughed late in autumn, we
could never obtain any of this species. It may be stated as a gener-
al observation, that this animal is a resident of fields and cultivated
grounds ; we have, however, witnessed two or three exceptions to this
hnbit, having caught some in traps set at night in the woods, and once
having found a nest under the roots of a tree in the forest, occupied by
an old female of this species with three young two-thirds grown ; this
nest contained about a handful of chestnuts, which had fallen from the
surrounding trees.
!t is generally believed, that the Jumping Mouse, like the Hampster of
Europe, (Cricetus vulgaris), and the Marmots, (Arctomys), hibernates, and
passes the winter in a profound lethargy. Although we made some
efforts many years ago, to place this matter beyond a doubt by personal
observation, we regret that our residence, being in a region where this
species does not exist, no favourable opportunity has since been afforded us.
Naturalists residing in the Northern and Middle States could easily
solve the whole matter, by preserving the animal in confinement through
the winter.
To us the Jumping Mouse has rot been an abundant species in any
part of our country. Being, however, a nocturnal animal, rarely seen
during the day unless disturbed, it is in reality more numerous than is
generally supposed. We have frequently caught it in traps at night in
localities where its existence was scarcely known.
This species, feeding on small seeds, does very little injury to the farmer ;
It serves, like the sparrow, to lessen the superabundance of grass seeds,
which are injurious to the growth of wheat and other grains ; it is fond
of the seeds of several species of Arnaranthus, the pigweed, (Ambrosia),
burr-marygold, beggar or sheep ticks, (Bidens), all of which are regarded
as pests, he therefore should noi grumble at the loss of a few grains of
uW^
256
JUMPING MOUSE.
wheat or buckwheat. Its enemies are cats, owls, weasels, and foxes,
which all devour it.
OnOOKAPHICAL DISTRIBUTION.
if there is no mistake in regarding all the varieties of Jumping Mice in
the northern parts of America as one species, this little animal has a range
n»^arly as extensive as that of the white-footed Mouse. It exists, according
to llicHAUDso.v, as far to the North as great Slave Lake, Lat. ««". It is
found in Labrador and Nova Scotia, and in Upper and Lower Canada.
We have seen it in the Eastern ana Middle States, and obtained a specimen
on the mountains of Virginia, but have not traced it farther to the South ;
although we are pretty sure that it may, like the Sciurus Hudsonius be
found on the whole range of the Alleghanies. Say observed it on the base
of the Rocky Mountains, and Mr. Townsend brought specimens from Oregon,
near the mouth of the Columbia River. We can scarcely doubt, that it
will yet be discovered on both sides of the mountains in California and
New-Mexico.
GENERAL REMARKS.
On looking at our synonymes our readers will discover that this species
has been described under an endless variety of names. We have omitted
a reference to RAFiNEsauE, who indicated several new species in the Ame-
rican Monthly Magazine. We have concluded, that a writer exhibiting
such a want of accuracy, who gives no characters by which the species
can be known, and who has involved the science in great confusion, and
given such infinite trouble to his successors, does not deserve to be quoted.
We had attached to our plate the specific name given by Dr. Bar-
ton, (>/. ^/neWcrtrtM.v), this we would have preferred to either of the others,
especially as it now seems probable, that this is the only si)ecies in Norlh
America. The names Hu<honius, Lahrwlorius, and Canadensis, are all
exceptionable, as it appears to be as abundant in the Northern and
Eastern States, as it is in Hudson's Bay, Labrador, or Canada. Thera is
an evident impropriety, although we confess when hard pressed for a
name we have often committed the error ourselves, in naming species
after localities where they have been found. The Meles Lahmdoria of
Sabine, and the Lepus Virginianus ofHARi.AN, are both famiUar examples.
Having recently had an opportunity of consulting, the original description
of Zimmerman, published between the years 1778 and 1783, we are con-
vinced that he was the first scientific describer, and we have accordingly
adopted his name. Barton, at a little later period, published a good
JUMPING MOUSE.
257
description with a figure. Dav.e« shortly afterwards published it under
the name of Drpus Canadensis. Sab.ne published a specimen with a
muMlated tail, which he named M. La,ru,loriu., J R J^Zl' :
specmen from the North, which he referred to the northern spec'es
under the name of 3/. Lal^radonus, supposing there was still anothl;
many specimens from all the localities indicated by authors. There is
a considerable variety in colour, young animals being paler and having
the l.nes of demarcation between the colours less distinct. There is also
a great dilference between the colour of the coat of hair in the prtg
before U .s shed and that of the young hair which replaces the wi er'
pelage. The tail varies a little, but is always long in all the specimens
7 he ears, sue, and habits of all are similar. We have thus far seen
no specmen .h.t would warrant us in admitting more than one species
into our American Fauna. '^
'i.i
VOL. 11. — US.
368
GENUS FEUS.— LisM
Incisive -' Canine — ; Molar — = 30.
• 1—1 >— 3
There are two conical teeth, or false molars, in the upper jaw, which
are wanting in the genus Lijnx ; a large carnivorous tooth with three
lobes ; the Iburth cheek-tooth in the iipper jaw nearly flat, and placed
transversely ; the two anterior cheek-tenth in the lower jaw false.
Head, round ; ears, short and generally triangular, not tut't.-d ; in many
species a white spot on their outer surfaces ; no mane ; tail, long; tongue
roughened with prickles ; anterior extremities with live toes, posterior,
with four ; nails curved, acute, and retractile.
Habit savage, feeding in a state of nature on living animals only, which
they seize by surprise, and not by the chase, as is the habit of the dog
woli; &c.; leaping and climbing with facility ; speed moderate ; .sense of
sight good ; that of smell imperfect.
There are 33 species of Long-tailed Cats described, inhabiting the lour
quarters of the world. Four species only are positively known to exist
north of the tropics in America.
The generic nams is derived from the latin vrord Fclis — a cat.
FELIS PARDALIS.— Linn.
Ocelot, OR Leopara)-Cat.
PLATELXXXVI .—Male.- Winter Pelage.
F. Magnitudine. Lynx rufus. Cana. {s. potiits Jlava), mnculis ocellaribus
magnis fulvis nigro-limbatis, in lateribus facias oblequas formantibus ;
fronte striis 2 lateribus nigricantibus cauda corporis longitudine dimedia.
CHARACTERS.
Size of the Bay Lynx ; general colour grat/, marked with large fawn-
coloured spots, bordered with black, forming oblique bands on thejlanks ; two
black lines bordering the forehead laterally.
II:
OCELOT.
259
BYNONYMEB.
F«Li8 Pardalis. Linn., p. 02.
Iliirlaii'M Fuiina, p. 06.
Ciiv. An. King, vol. 8, p. 470.
GiilfitirH An. King., vol. 5, p. 107.
Shaw's Zoology, vol. 2d, p. 350.
N
H
•I
«4
l«
M
DESCRIPTION.
Head, short ; neck, long -incl thin ; body, long and slender; .ail. rather
thick, and of moderate size ; hair, rather soli, and not very dense.
COLOUR.
The outer surface of the ear is bla.-k, 'itha^..: e patch beneath ; chin
and throat white, with a black bar immediateiv beneath the chin, and
another under the neck. On the chest and under surface, white, with ir-
regular black patches. There are small black spots disposed on the
head, surrounded by reddish-brown, a black line runs longitud.nally on the
sides ol the head to the neck. The whole back is marked with oval
figures, and in some specimens with longitudinal black stripes ed-ed with
fawn-colour. Upper surface of the tail irregularly barred with black and
whiif, the extremity black.
Specimens vary much in their markings, and we have not found two
precisely alike.
DIMENSIONS.
Male, procured by Col. Harsev in Texas, seven miles from San An.
tonio, December, 1815,
Frompointof nose to root of tail. ...
Tail,
Height from nails to shoulder, - - . .
" of ear posteriorly, ....
Female.
Length of head and body - - - _ ,
•• tail ---.-.'.
From nose to shoulder. - - - - .
HABITS.
Before describing the habits of this beautiful species, we must enterinto
the difficult task of separating it from several other spotted, leopard-lik«
Feet. Inches.
2 11
1 3
1 2
If
PeeC IncbM
2 4
1 1
1 1
260
OCELOT.
I I
li i
l\
cats, that have been confounded with it. Of these, the most similar in ap.
pearance is perhaps the Felts mitis, which is found in the tropical portions
of North America, and in the vvarmer parts of South America.
The Fvlis mitis has in fact been figured, and described by SirAvv, Vol. ",
p. 35t), (unless we deceive ourselves), as the Ocelot, (our present species)
while liis figure of the Jaguar, (opposite p. 354), is probably drawn from
the Ocelot, although, so poor a figure as to be hardly recognisable.
The descriptions and figures of the Ocelot, that we find in old works on
natural history, are so confusing, and unsatisfactory, that we are obliged
to throw aside all reference to them in establishing any one of the feline
tribe as our animal, and leave the reader to decide whether Buffon, speak-
ing of the Ocelot, as two feet and a-half high and about four feet in length,
meant the subject of our article, which is only two feet-six inches long
from nose to root of tail, the Felis mitis, or the Jaguar ; and whether Pen-
nant referred to the same anim-^l, which he de[,cribes, when speaking of the
Ocelot, " as about four times the size of a large cat," (about the size of our
specimen of the Ocelot).
The description of this species in Linn^us is so short, that it is almost
equally applicable to either the Jaguar, the Ocelot, or Felis mitis : "Felis
Cauda elongata, corpore maculis supcrioribus virgatis, infcriorihus orhicula-
tis.^^ Sys. Nat. Gmel. p. 78. Brisson is also very concise in giving the
character of the Ocelot ; F. rufa, in ventre exalho Jiavicans, maculis nigris
in dorso longis, in ventre orbiculntis variegata." Quadr. 109. We are on
the whole inclined to consider the species described by Pennant as the
Mexican Cat, the Ocelot or Leopard-Cat of the present article, and the lar-
ger animal described by other authors, as the Felis mitis, as young of the
Jaguar, or perhaps females of this last named species, and we have not yet
met with the Felis mitis within our range, although we have seen such an
animal alive in New- York, one having been brought by sea from Yucatan .
Our animal is quite well known in Texas as the Leopard-Cat, and in
Mexico is called the Tiger-Cat, it is in the habit of concealing itself in hol-
lows in trees, and also by squatting upon the larger branches. It is rather
nocturnal, and preys upon the smaller quadrupeds, and on birds, eggs, &c.,
when they can be seized on the ground.
The activity and grace of the Leopard-Cat, are equal to the beauty of its
fur, and it leaps with ease amid the branches of trees, or runs with swift-
ness on the ground. These Cats seldom stray far from woods, or thickets
bordering on rivers, streams, or ponds, very rarely lying on the hill-sides, or
out on the plains.
They run like foxes, or wild-cats, when chased by the hunters with
hounds or other dogs, doubling frequently, and using all the stratagems of
OCELOT.
261
the gray fox before they take a straight course, but when hard pressed
and fatigued, they always ascend a tree, instead of running to earth
Like a 1 the cat tribe, the Ocelot is spiteful when confined in a cage and
snarls and spits at the spectator when he draws near; but we have never
seen U stnke through the bars like the leopard, which sometimes inflicts
severe wounds on the incautious or fool-hardy person, who. to see it better
approaches too closely its prison. '
According to our information, the Ocelot only has two youn^. at a litter
but we have not had an opportunity of ascertaining 'this Volt ':::
The specimen from which our figure was drawn, was procured by Gen.
H.HX.V, who sent it fresh killed to J. W. Acoubov, then at San An-
^n.o on an expedition in search of the quadrupeds of Texas, for our work
We here give an extract from his journal.
" But for the kindness of Col. Hah.vev, I might never have made the draw-
mg of this most beautiful of all the North American feline race. Col. H 21
sent for my trunks, and while I waited the return of the sergeant's guTrd
who went to fetch them, I saw him daily. He introduced me to M '
theTT T r\ "' ""'''■ ''^^''^' ^''"'"^^^^ ^y friend, boarded, aid
I was invited out to the camp, and as I talked of the animals I was most
anxious to procure all seemed desirous to aid me. Col. H.h.bv, fond
field sports, as active and industrious as he was tall and magnificent-look-
ing, waked at day light the lone prairies and swamps with shouts of e.
couragement to his small pack of well-chosen dogs, till they in turn bur t
forth in full cry on the hot trail of a magnificent specimen of this most n
cresting snecies. I had just returned from an examination of all my II
raps ; some were sprung, yet nothing but fur was ieft, showing that a strong
wolf or lynx had been caught, but had pulled away ; thus preventing
perhaps, the capture of some smaller animal that I wanted ; and rats, mice
skunks, or other little quadrupeds, were eaten nightly whilst fast in the
teel teeth, by these prowlers. I «at down, to think of spring, guns, and Ion.
for means to prevent this robbery of my traps, when a sergeant came in'
with the result of Col. H.h.bv's morning-.s chase, the beautiftl Ocelot? rom
This was a new animal to me, as, though I knew of its existence I had
never se.n one, so that my delight was only equalled by my desire to paint
a good figure of it. Its beautiful skin makes a most favourite bullet
pouch, and Its variegated spots are only surpassed by the rich glossy coat
nnd (ur of the far famed ' black ottc"' ^
In his many long hunts. Col. Hak.kv must have often and often past the
I H
f.''4
262
OCELOT.
lurking Wako and Camanche, who quailed at his soldierly bearing, while
any other man would have had perchance a dozen arrows shot at him.
GEOGRAPHICAL DISTRIBUTION.
•
We have heard of an occasional specimen of this cat having been ob-
tained in the southern parts of Louisiana. Nuttall saw it in the State ol
Arkansas ; our specimens were procured in Texas. It is common in
Mexico ; its southern range has not been accurately determined.
GENERAL REMARKS.
Jfuch confusion still exists among writers in reference to the spotted cats
of i^Iexico and South America, which can only be removed by the
careful observations of naturalists in the native regions of these closely alii,
ed species.
268
VULPES FULVUS.— Desm
American Red F(ix.
PLATE LXXX VII._Male.
V. Rufo-fulvoque varius ; collo subtus ventreque imo albis ; pectore
cano ; antibrachiis antice prodiisque nigris ; digiiis lulvis ; caudS apice
alha. '^
CHARACTERS.
Fur reddish or fuhous ; beneath the neck and helhj white ; chest gray
front part of the fore legs and feet, black ; toes fulvous; tip of the tail white
SYNONYMES.
Canis Fulvus. Deam. Mamm. p. 203.
" Fr. Cuvier, in Diet. des. Sc. Nat. VIII. p, 568.
REyARD DE VmaiNiE. Palesotde BeauvoisMem. Sor.
Le Rbnaud. Bullet, Soe. Phil.
Kei) Fox. Sabine, Franklin's Journ. p. 65G.
Canis Fulvus. Harlan, 89.
" Godman, vol. 1, p. 280.
VuLPEs Fulvus, Rich. Fauna, B. A.'p. 91.
De Kay, Nat. Hist. N. Y., p. 44, fig. 1, pi. 7.
DESCRrPTION.
Thfe animal bears so strong a resemblance to the European Fox (v vul
gans), that it was regarded as the same species by early naturalists. No
one, however, who will compare specimens from both countries, can have
a doubt of their being very distinct. Our Red Fox is a little the largest its
logs are less robust, its nose shorter and more pointed, the eyes nearer
together, its feet and toes more thickly clothed with fur, its ears shorter
It hits a finer and larger brush, and its fur is much softer, finer, and of a
brighter colour.
It stands higher on its legs than the Gray Fox, and its muzzle is not so lono-
nnd acute, as in that species. It is formed for lightness and speed, and is
more perfect in its proportions than any other species in the genus with
wliich we are acquainted.
The hair on the whole body is soft, silky, and lustrous ; the ears are cloth-
ed with short hairs on both surfaces, and the feet and toes are so clothed
rW
264
AMERICAN RED FOX.
with hair, that the nails are concealed. The body of this species has a
strong musky smell, far less disagreeable, however, than that of either
the skunk or mink. It becomes less offensive in a state of domestication.
COLOUR.
Point of nose, outer extremity of ears, and outer surfaces of legs below
the knees, black ; forehead, neck, flanks, and back, bright-reddish, and a
little deeper tint on the back and fore-shoulders ; around the nostrils,
margins of the upper jaw, and chin, pure white ; throat, breast andanar-
row spsice on the under surface, dingy-white ; extreme end of brush
slightly tipped with white ; inner surface of ears, and base of the outer sur-
face, yellowish. The hair on the body is of two sorts : long hairs interspers-
ed among a dense coat of softer, brighter, and more yellowish fur ; on the
tail the longer interspersed hairs are more numerous, and many of them aro
quite black, giving the tail a more dusky appearance than rest the of the body
In addition to the distinct varieties of this species, the black and cross
Fox, we have seen some shades of difference in colour in the red variety.
In some the colours on the back are considerably darker than in others
We have seen several with the nose and chin nearly black, and in others
the white tip at the tail is replaced with black.
DIMENSIONS.
From point of nose to root of tail.
Tail (vertebra;)
*' to end of hair, - . -
Height at shoulders, - - .
•* of ears posteriori V -
Feel.
Inchei
2
fl
1
1
1
5
1
1
2f
This Fox, in times gone by, was comparatively rare in Virginia, and
larther south was unknown. It is now seldom or never to be met with
beyond Kentucky and Tennessee. Its early history is not ascertained, it
was probably for a long time confounded with the Gray Fox, (which is in
many parts of the country the most abundant species of the two,) and af-
terwards was supposed to have been imported from England, by some Fox-
hunting governor of one of the " colonies." It was first distinguishod from the
Gray Fox and hunted, in Virginia; but now is known to exist in all the
Kiirthcrn States, and we are somewhat surprised ttiat it should so long
have been overlooked by our forefathers. No doubt, however, the culti-
AMERICAN UED FOX.
265
vanon and improvement of the whole country, is the chief reason why the
lied Pox has become more numerous than it was before the Revolution,
and a wdl probab y be found going farther south and west, as the wood^
and forests give place to farms, with hens, chickens, tame turkeys, ducks
«&c. in the barn-yards. , "u^">»,
The Red Fox is far more active and enduring than the Gray, and gene-
rally runs in a more direct line, so that it always gives both dogs and hun-
ters a good long chase, and where the hounds are not accustomed to follow
It will frequently beat-out the whole pack, and the horses and huntsmen
to boot.
In some parts of the country, however, it is chased and killed with dogs
.n fine style The following account of the mode of taking the Red Pox'
at the , ,,^, i„ New-Jersey, near Cape May, is from an interesting letter
wrmen to us m December. 1845, by oar friend Edward Hakr.s, Esq., of
Moorestown, m the neighbourhood of Philadelphia ; it is quite different from
the ordinary mode of hunting the Red Fox. He begins thus ■
" ^^T"^""^: t ''''''' ''^°' ^ "^'"^ '° ^"P^ ^^y Court-house, where I
pent Monday and Tuesday among the quails, Q.rciri. .ir^Uucn^^s), which
I found exceedingly abundant, but the ground so bad for shooting, that in
both days two of us shot but thirty-three birds. On Wednesday my friend
Mr. Holmes took me to Beasi.ey's Point at the northern extremity of the coun-
y ; here I was sorry to learn that young Beaslbv, who was to have re-
appearance ; his father, however, showed agreatdesire to forward my views
ni regard to "Monsieur Reynard." The next day it rained cats anddogs, and
Tom Beaslev did not arrive in the stage. In the afternoon it cleared oft
sufficiently to make a " a drive" in the point, where we started a noble
specimen m beautiful pelage, but alas! he would not come near the
standers.
The next morning, we drove the same ground, being the only place on the
main land where there was any prospect of driving a Fox to standers with-
out dogs, (of which there are none in the vicinity). This time we saw
none. After dinner I took my pointer, and bagged eight brace and a half
of quails, having this time found them on good ground. The next day
Saturday, with three drivers, and three standers, we drove .he beach for
five and a-half miles, without seeing a fox, and so ended ihis unsuccessful
expedition I had great hopes of this beach. (PECK's),as it had not been hunt
e_d since^the winter before the last, althc ..> some of the gunners told m.
they had seen but few " signs" since that time.
The mode of driving, which requires no dogs, is for the drivers to he fur
nished with two boards, or shingles, which they strike together, or with
VOL. II. — 34.
266
AMERICAN RED FOX.
what is better, a rattle, similar to a watchman's. The standers are sent
ahead to a narrow part of the beach, where the creeks of the salt-marshes
approach nearest to the sand-hills : when they are supposed to have reach-
ed their stands, the drivers enter, and walk abreast among the bushes,
between the sand-hills and the marshes, making all the noise they can,
w'ith their lungs, as well as their boards or rattles ; and these unusu-
al noises are almost sure to drive the Foxes to the standers, where
if they pass harmless, they have again to run the gauntlet to the
end of the beach, at the inlet, where, Mr. Beasley assures me, he
has known seven Red Foxes cornered, out of which four were killed, and
three escaped from bad shooting. We made four drives in the five and
a-half miles.
The facts in regard to the history of the Red Fox on the Jersey coast
that I have been able to collect, are few ; such as they are 1 will give
them to you.
Certain it is that they frequent the beaches in great numbers, and so far
as 1 can learn, the Gray Fox is not found in the same places, nor is the
raccoon, which we know to be po abundant on the sea islands and beaches
of our southern coast. They pass to the beaches on the ice, in the winter
season, when the " sounds" are frozen, and have frequently been seen in the
day time, making their passage, though doubtless it is more frequently per-
formed in the night. Their means of subsistence there ar« ample, consisting
of wild fowl of various kinds, upon which they spring while they are asleep
upon the ponds and creeks, but more particularly upon the wounded fowl
which escape from the numerous gunners, also crabs and fish, which are
thrown up dead by the surf, and rabbits and wading birds, in the summer.
A marvellous story is told of their sagacity in selecting the food they like
best, which is vouched for by Mr. Beasley, and all the gunners along
f^hoie, but which 1 think i«:q"ires confirmation, at least so fur as to have
the fish in question, seen by some naturalist in the state described by the
narrators, in order to ascertain its name, or describe it, if new, before its
publication is ventured on. The story is, that a certain fish, called the cramp-
fish, from its supposed power of paralizing the hand which touches it while
living, is thrown ashore dead, by the surf in the winter season, that every
one of these fishes contains a bird, such as the coot, (either fuscu or per-
spicillata), or a gull, which appears to have destroyed the fish, by its j)rov-
ing rather hard to digest, without having been plucked. Mr. Fox finds
the fish that has come to this deplorable end, and either in the vain hope
of restoring animation to the unfortunate defunct, or for the gratification of
a less noble impulse, he makes a longitudinal incision into the peritonai'um
of the subject, and extracts the bird, oi' which he makes a meal ; but, n)ind
AMERICAN RED FOX.
267
vou Mr. Fox has profited by the avvlb, examp-e before him-he picks the
B to r '•'": •;■ '''''■^'— •• --">- what you cannoTL't
But, to be serious, I do not mean to ridicule the f-iK wli.K t T
cannot answer for it miirht in u^ ,,1 • • , wnicn l
t,i lor, n migl.t in its plain, unvarni.siied form, without beincr
wUhTm , I. ""■' '^''^ '" '''''^ '"'"^'''"^^ ♦he length of four-feot
uith a mouth twenty-twa inches wide, they are sealed, and are said to re
semb e, somewhat, the sea cat-fish, with which I am no't accuaintl^h The
Fox on the beach when hunted by hounds, resorts to his usual trick of
tak.ng he ^.ater, to throw the dogs off the scent, by followingthe r t ea
"n Tb ,"/ "^ "i!"" " '^' ^"'^'^^ ""'' ^^^"' ♦h-^ '.V-^ ^own among the
and hil s to rest, while the dogs are at fault. In the Lods on the ml n
land bo h Red and Gray Foxes are abundant, the latter rather predomZ:
u.g. 1 he Foxes are abundant on some of the beaches, and generally may
be procured Mr. Slkxcp., of Mount IIollv, has been on a party when
We have not been able to procure the fish which is alluded to in the
foregoing, but have no doubt of the correctness of the account. The R.d
Fox will eat fish as well as birds, and when hard pressed does not refuse
even camon. It is, therefore, probable that the discovery of the bird
withm the dead fish, may be the result of accident rather than of instin t
reason, or keenness of smell on the part of the Fox ; for when he begins
to devour a hsh he must soon find the more savoury bird in its stomach
and being fonJer of fowl than offish, he would of course eat the bird Id
eave the latter. A Fox aller having in this w.y discovered coots, gulls
or any other bird, would undoubtedly examine any dead fish that he came'
across, in hopes of similar good luck. Hence the foxes on the beaches have
sTohTr";"'""'.?"'"''^'^'" '''"•'"'•"-" '^"■'■•^ '■'•"- ♦he stomachs oj
uch fish as have swallowed them, and are cast ashore .lead by the storms
on he coast; and they also at times get a plentiful meal from the dead
birds that float ashore. We received a beautiful specimen of the Red Fox.
m he flesh from our friend Mr. II.kris, not long af>er the foregoing letter
and our figure was drawn from it. We represented the Limal jus;
caught m a steel-trap. ''
The Red Fox brings forth from four to six young at a litter, although
t.me after they are born, with a soft woolly fnr.c,uite unlike the oat of the
grown anima, and generally of a pale rufous colour. FrequenX ho "
eve, the cubs in a litter are mixed in colour, there being some' edlnd sle
£'68
AMERICAN RED POX.
bipck-cross Foxes together: when this is the cane it is difficult to tell
which are the red and which the cross Foxes until they are somewhat
grown. In these cases the parents were probably different in colour.
This animal feeds upon rats, rabbits, and othrr small quadrupeds, and
catches birds, both by lying in wait for them, and by trailing them up
in the manner of a pointer dog, until watching an ojjportunity he can
pounce or spring upon them. In our article on the Gray Fox, (vol. 1.,
p. 164) we have described the manner in which this is done by that
species, and the Red Fox hunts in the same way.
The Red Fox also eats eggs, and we have watched it catching crickets
in an open field near an old stone wall. It is diverting to witness
this — the animal leaps about and whirls round so quickly as to be able to
put his foot on the insect, and then gets hold of it with his mouth ; we
did not see him snap-* at them ; his movements reminded us of a kitten
playing with a mouse.
We once knew a Red Fr-, that had been chased frequently, and always
escaped at the same spot, by the hounds losing the track : the secret was
at last found out, and proved to be a trick somewhat similar to the
stratagem of the Gray Fox related in our first volume, p. 171 ; the
Red Fox always took the same course, and being ahead of the dogs so
far that they could not see him, leaped from a fallen log on to a very
sloping tree, which he ascended until conce? "ed by the branches, and
as soon as the dogs passed he ran down and leaping on to his old
track ran back in his former path. So dexterously was this " tour "
performed that he was not suspected by the hunters, who once or twice
actually whipped their dogs off the trail, thinking they were only fol-
lowing the " back track."
The Red Fox is in the habit of following the same path, which enables
the fox hunters to shoo„ this species from "stands," even in a country
where the animal has room enough to take any course he may choose
to run. The "hunters" who go out from the city of New- York, are
a mixed set, probably including Germans, Frenchmen, Englishmen, and
Irishmen, and each one generally takes his own dog along, (on the
speed and prowess of which he is ready to bet largely,) and the hunt
is organized on the height beyond Weehawken in " the Jerseys," where
a good many Red Foxes are to he found, as well as more Gray ones.
The men are all on foot, and station themselves along ridges, or in
gaps in the rocky hilly country, now running to a point, to try and
get a shot, now yelling to their dogs, and all excitement and hubbub.
If the Fox doubles much, he is verj apt to get shot by some otio before
he passes all the "standers," and the hunters then try to start another;
AMERICAN RED POX
2G9
leal "of As' f ™ f " ""'"'• " ""= ""■'■'"'"'"' " '""k "1 a good
«c yh.ll „ ,0 s,a„,l, i„ .ho Newark .ar,he,, fa„.i,i„.ly „„.,!„ ^
hol,l .h. Fox „ fte,„„„t|y „e„ l,y ,h„ whole company of hun.e , 'nd.he
eha» ., Ie„,,„e„ed „„. ,„ a r„„ of ,„a„y mile' a, Rel, „," 1
aga,n toward the high ridge» nearer the Hudson River
We wdl give an an aeeount of one of these hunts as related by some
Z:iT • :t° """"^ *"° ""' '"'"=" <'» -"""""= their IrH
Alter some beat.ng about among the thickets and ravine,, „-e Ibnnd
the og, h. straye away down .he side of the hill, nearly t; .he e""
of the marshes, and raising our horn to call ,hem up. observed .ha. thev
where ,n .hem; we ,mmed,a.ely gave a loud halloo, and ur-ed all
he hound, to the chase. The eur turned .ail a. once, the w^e pact
opened -after him in full cry, and all .he hun.ers ca^e running M
Irom .he woods ,o the brow of ,!,„ hill, whence we had a v cT of th.
most of the hunter, thought he was one •■ certain." he shewed good hot
^m. took several leap, over the stone walls and feaee,. and dodge, abo,
and round patches of briars ,a„d rocks with extraordinary agiuly u„,i
o tt T' """""^ '" """"• "'■™ "" "-^Wvely « strLed 1^= un
rsLal, flTrT"':', "" ""?"• "' J"'""'" -" '» " «-" "-losing
a stnal farm yard, and disappeared within, i.nmediately setting up a lou3
l.ark of deuance. while some of ,he hunlers who had expressed most
eonfldenee. were loudly laughed at by their comrades. whoM ..eririy
to '"ur, lllr'^-nilir "'• ^"' " ^° ™'^ "-^ ">^' " ^^ -"^»'.
Dr. Richardson tells us that tho hp«t f,.v k * • , .
-;hood.ii,egingthatZ::ret;:;'Lh7e:rre,"^ "■ "^ "^'^^•
ouj't'hrrurhitLir-'"^*"* '"»'"'-"""' --- -^ '» -„
JtJurrir r''""^ "■'""""' '""■ ••■^ "onhem .o .he .South.
species havmn; ecom(- tTiore numnrons than
270
AMERICAN RED FOX.
11 ;
If ' \
%
it was before the Revolution. This i(iea, however, wouhl seem to be over-
thrown by the oontinuetl ahuiuiiiiice oi'Gmy Foxes in the Eastern States.
In the early history of our country the Red Fox was unknown south of
Pennsylvania, that State being its Southern limit. In process of time it was
found in the mountains of V'irginia, where it has now become more abun-
dant than the Grav Fox. A few years afterwards if appeared in the
more elevated portions of North Carolina, then in the mountains of South
l^arolina, and finally in Georgia ; where we have recently observed it.
This species was first .seen in Lincoln County, Georgia, in the year 1810, '
since then it has spread over the less elevated parts of the country, and is
not rare in the neighbourhood of Augusta. We are informed by Mr.
BEri.E, an intelligent observer of the habits of animals, that on one occasion
near Augusta, as he wf using a call for wild turkey.s, a little before
sunrise, in the vicinity of Augusta, two Red Foxes came to the call, suppos-
'm\\ it to be that of a wild turkey, and were both killed by one discharge
of his gun
In order to ascertain whether the speed of me Red Fox was as great
in the south as in the colder regions of the north, several gentlemen near
Augusta, in the winter of 1844, resolved to test the question by a regular
Fox chase. They congregated to the number of thirty, with one hun-
dred hounds, many of them imported dogs, and all in fine running order.
They started a Fox at two o'clock on a moonlight morning. He took to
a pretty open country on the west bank of the Savannah river. A
number of gentlemen were mounted on fleet horses. Mr. Bf.ile rode in
succession three horses during the chase, two of which \t'ere good hunters.
The pursuit of the flying beast was kept up till three o'clock in the "
afternoon, having continued thirteen hours, when the horse ^ and the
whole pack of hounds were broken down, and the hunt was abandoned.
This accouni does not accord with that given by Richardson, who states
(Fauna Boreali. Am. p. 93,) '* The Red Fox does not possess the wind
of its English congener. It runs for about a hundred yards with great
swiftness, but its strength is exhausted in the first burst, and it is soon
overtaken by a wolf or a mounted huntsman." It is quite evident that
our estimable friend never had an opportunity of participating in the
chase of the American Red Fox.
Whilst the Gray Fox seldom is known to dig a burrow, concealing its
young usually beneath the ledges of rocks, under roots, or in the hollow
of some fallen tree, the Red Fox on the contrary, digs an extensive burrow
with two or three openings. To this retreat the Fox only flies afler a
hard chase and as a last resort. If, as often happens, the burrow is on
level ground it is not very difficult by ascertaining the direction of the
AMERICAN RCn POX.
271
?a lencs and sinking a hole at intervals of seven or eight feet to dig
out and capture the animal. When thus taken he di.splays b'ut mt e
eourage-.on.eti.e. like the Opossum. Cosing his eyes' aL Sgnlng
It .s at this period, when the snows in the Northern States are still on
In. Th ^"' ' ' ''' ^"'■"^'•^ '""* ^'^ P'-«^''^« '■-'^ <■- their
lurni f 1 ^^IP'^'-*'^"'-'^ ^«-' «^ young lambs, which they carry off
poultry, and have a bad reputation with the farmer. They likewise feed
rS:::;:" '"'"'t* ^ ^^^" '- -- '^^^^^^ ^^--'^' -^ A^^^^-t "
various species, as we have previously mentioned.
GEOGRAPHICAL DISTRIBUTION.
The Red Fox exists in the fur countries to the North, is found in La-
brador to the East, and in the Russian settlements on the West of tur
contment. Its Southern limit at present is Abbeville, in Sourclrolina
siatetT:; ""'rV ' '-'' ""'''''^^^^ ^^- ^«- seen i ose'
S ates, near the sea-board. It also appears in Tennessee. Kentucky, and
Missouri. We have not heard of its existence in Florida. Louisiana, o
GENERAL, REMARKS.
It is now so generaUy admitted that the Red Fox of America is a d.s-
met spec.es from the European Fox ; that a comparison seems unneces-
H^ary. We have seen no specimen in this country that can be referred tc
27-'
LEPUS AllTRMISIA.— Bach.
W()RM-wcM)i» Hark.
P I, A T F. 1. X X X V 1 1 1— Malm and Pemalb.
L. Parvus, cane.sccns,nuclia ct crurilms (lilutp foru^iiH'ls, cuikIii supra
canescoiis, subtus albn, pula et ventre albis, vellore toto ad basin cano :
auriculis lungiludine capiiis, tarsus dense vestitis.
characters.
Small ; of a gray colour, pale riifus on the back of the neck arid legs ;
tail, above, the colour of the body ; beneath, white ; under parts of the neck,
and lower .surface of the body, white ; all the fur gray at the base ; ears
as long as the head ; tarsus, well clothed.
aVNONYMEa.
Lepus Artemisia. Pach, Worm-wood flare. Journal Acad. Nat. Sciences,
vol. 8, p. 1, p. 04.
description.
This small Hare is a little less than our common gray Rabbit, the
ears arc longer and more conspicuous. The head is much arched, and
the upper incisors deeply grooved.
colour.
This species is grayish-black and brownish-white itbove ; the fur is
soft, pale-gray at the base, shaded into brownish rxfernally, annulated
with brownish-white near the apex, and black at the tips : under parts,
and inner sides of the limbs, white ; the hairs pale-gray at the base ;
neck, with the hairs on the sides, and under parts gray, tipped with
brownish-white, having a faint yellow hue ; chin and throat grayish-
white, the hairs being sray at their base, and white at their tips. The
whole back of tlie nef;k .inc li r>bs exteriorly of a pale rusty-fawn colour;
hairs on the neck unifora-. ^^. 'he base; soles of the feet, very pale soiled
yellowish-brown; tail, ^'jioatd above as the back, with an admixture
of grayish-black hairs, be.ieath, vi^hite , ears, externally on the anterior
L^^
supra
canor
' /,
'cgs,
neck,
: ears
ciences.
lit, the
id, and
fur is
lulatrd
parts,
base ;
with
■ayish-
The
!olour;
soiled
lixture
iterior
m
^ .*
'in
n ! .
li I
E-i
•-J
LJ
<«
i
"J
0,
^^,
%
WORM-WOOD HARE.
273
part, coloured as the crown of the head ; posteriorly, asny white ; at the
apex margined with black ; internally, nearly naked, excepting the pos-
terior part, where they are grizzled with grayish black and white; in the
apical portion they are chiefly white.
luches.
12
3
2
2
1
1
UoSb.
2
8
7
1
DIMENSIONS.
Length from nose to root of tail.
From heel to point of longest nail, -
Height of ears externally, -
From ear to point of nose,
To end of fur,
HABrrs.
Mr. TowNSEND, who procured this species at Fort Walla-walla, re-
marks, " it is here abundant but very s'w and retired, keeping constantly
in the densest wormwood bushes, and leaping with singular speed from
one to another when pursued. I have never seen it dart away and run
to a g.-eat distance like other Hares. I found it very difficult to shoot this
animal, for the reasons stated. I had been residing at Fort Walla- walla
for two weeks, and had procured only two, when at the suggestion of Mr.
Pambrun, I collected a party of a dozen Indians armed with bows and ar-
rows, and sallied forth. We hunted through the wormwood within about
a mile of the Fort, and in a few hours returned bringing eleven Hares.
The keen eyes of the Indians discovered the little creatures squatting
under the bushes, where to a white man they would have been totally in-
visible. This Hare, when wounded and taken, screams like our common
species.
GEOGRAPHICAL DISTRIBUl'ION.
"This small Hare," we are informed by Mr. Townsend, "inhabits the
wormwood plains near the banks of the streams in the neighbourhood of
Fort Walla-walla. I cannot define its range with any degree of cer-
tainty, but I have every reason to believe that it is very contracted, never
having met with it many miles from this locality."
VOL. u. — 35
mLI
m
I
274
SCIURUS SAYI I.— Auo. and Bach.
Say's Suuirrel.
PLATE LXXXIX.— Males.
S. Sciurus ciiiereus magnitudine sub a-quans. Corpore supra lateribus-
que cario-nigroque variis ; capitis lateribus orbitis que pallide caiio-ferru-
gineis ; genis auriculusque saturate fuscis ; cauda supra ferrugiueo-ni-
groque varia, infra spleudide ierrugiiieii.
characters.
About, the size of the cnt-sqvirrel {S. cinereus) ; body above, and on the sides
mixed with gray and black ; sides of the head and orbits, pale ferruginous ;
check and under the eye, dusky ; tail, above, mixed with ferruginous and
black, beneath^ bright ferruginous.
8YNONYMES.
SriuRUS Maorodrus. Say, Long's Exped. vol. 1., p. 115.
S. Maonicaudatus. Harlan, Fauna, p. 178.
S. Mackoureus. Godman's Nat, Hist. vol. 2, p. 134.
DESCRIPTION.
In size and form this species bears a considerable resemblance to the
Cat-Sqii iTpl (-S. cinereus). It is a little longer in body, not quite as stout, and
has shorter ears. In length and breadth of tail, they are about equal.
The first molar tooth in the upper jaw, which in some of the species is de-
ciduous and in others permanent, was wanting in the six .specimens we ex-
amined: we presume, however, it exists in very young animals ; mamma;,
8, placed equi-distant, on the sides of the belly ; palms, as is usual in this
:enus, naked, the rudimental tliiunb protected by a short blunt nail ;
tlie feet are covered with hair, which extends between the toes, half con-
cealing the nails; hair on the body, of moderate length, not as coarse as that
ol' the Fox-Stpiirrel, {S. capistratiis), but neither as fine or woolly as that of
.S'. cinrrciis. Our specimens were obtained in summer. — Sav has remarked :
" The i'ur of the back in the summer dress, is from liiree-fifths to seven-
tenths of an inch long ; but in the winter dress, the longest hairs of the
middle of the back are from one inch to one and three-fourtlis in length
SATS SQUIRREL.
276
He also remarks that it is only in winter that the ears are fringed which
IS the necessary consequence of the elongation of the hair ; in our summer
specimens, the ears are thinly clothed with hair, not rising above the mar-
gins.
COLOUR.
The fur on the back, is for one half its length from the base plumbeous, then
pale cmnamon, then a narrow line of black, then cinereous, and broadly
t.pped with black, giving it what is usually termed an iron-gray colour •
the hairs on the under surface are of a iight-ash colour at base, and with-
out any annulations brighten into ferruginous at apex, the paler colours
beneath giving way to the broader markings on the extremities; the eyes
anc moustaches are black ; nails, dark-brown ; sides of face, around the eyes
both surfaces of ears, feet, chin, neck, inner surfaces of legs, and under sn'r-
l<ice of ta.l. bright ferruginous ; the hairs on the tail, are at their roots red-
d.sh-ye low, with three black annulations, and are broadly tipped with red-
dish-yellow.
DIMENSIONS.
From point of nose to root of tail
Tail (vertebra;)
** to end of fur -
Height of ear posteriorly
Foet, Indies.
1
m
13
t
HABITS.
The habits of this Squirrel are not very different from those of the Cat
Squirrel, to which it is most nearly allied. It does not run for so great'a
distance on the ground before taking a tree as the southern Fox Souirr^I
nor does it leap quite us actively from tree to tree as the norther,! Grnv
Niu.rrel, {S. m>gratorius,) but appears to possess more activity, and a-^ility
than the Cat Squirrel. " •
The forests on the rich bottom lands of the Wabash, the Illinois, and
the Missouri rivers are ornamented with the stately pecan-tree {Can,n
■>ln'c.fonn,s), on the nuts of which these squirrels luxuriate ; thev also re-
Hort to the hickory and oak trees, in the vicinity of their residene'e as well
ns to the hazel bushes, on the fruits of which they feed
They are becoming troublesome in the eorn-fiei<Is of the farmer, who has
commenced plantinghiscrops in the remote but rapidly improving states
and territories west of the Ohio. » -^ 1 » ^C'it«s
276
SAY'S SQUIRREL.
The flesh is represented by all travellers as delicate, and is said to be
equal in flavour to that of any of the species.
GEOGRAPHICAL DISTRIBUTION.
This squirrelis found along the shores of the Missouri, and in the wood-
ed portions of the country, lying east and north of that river ; we have re-
ceived several specimens, from Michigan, and it seems to be observed west
and north of that State.
GENERAL REMARKS.
This species was first discovered by Mr. Thomas Say, and by him des-
cribed and named Scim-us Macrourus. This name, unfortunately, was pre-
occupied, the Ceylon Squirrel having been so designated : (vide Pennant,
Hist. Quad. ii. p. 140, No. 330.)
Dr. Harlan and Dr. Godman in their respective works, seeing this, ap.
plied other names. The former calls it {Sciurus inngnicnudatus,) the latter
{Sciunis macroureus.) Authors copied Mr. Say's description almost liter
ally. Dr. Harlan gives Say's name {S. macrourus,) as a synonyme, and
Dr. Godman gives his name {Sciurus macroureus) as Say's name ; giving in
a note intimation that he has taken the liberty of changing the name by
the addition of a single letter, which he considers suflicient to render
further change unnecessary. Neither of these gentlemen claimed the dis-
covery of this species, gave original descriptions, or appear to have ever
seen the animal ; and, according to all rules which should govern natural-
ists, they had no right to n. le it. We, therefore, having procured a good
many specimens, and having from them identified, and described this
species, have used the grateful privilege of naming it in honour of its dis-
coverer, Mr. Say, and have given Dr. Harlan's and Dr. Godman's names
as synonymes.
277
MUS MUSCULUS.—LiNM.
Common Mouse.
PLATE X C._Male, Fkmalk, ato Yotmo.
M. Corpore fusco ; subtus ciner ascenti.
CHARACTERS.
Dusky gray above, cinereous beneath.
!
iiill
synonVmes.
Mus MuscuLus. Linn., 12 Ed.^ p. 83.
Mouss. Pennant, Arct. Zool. vol. 1, p. 131,
Mu8 MusctTLus. Say, Long's Expedition, vol. 1, p 262
Harlan, p. 149.
*' " Godman, vol. 2, p. 84.
DESCRIPTION.
The Common Mouse is more generally and familiarly known than any
other species, and therefore requires no very minute description. It is
sma 1 m size; head elongated ; nose, sharp; ears, large, erect, ovate, and
nearly naked on both surfaces ; legs, slender ; nails, sharp, slightly hooked ;
IhitTair "'^'^^ ^' '°"^ ^' *^' ^"^^'' ''^'^' ^""^ '''-^^'^ ^"^^'■^'^ ^'*h
COLOUR.
Eyes black; incisors, yellowish; whiskers, mostly black; fur on the
back, plumbeous at the roots, slightly tipped with brownish, giving it i
dusky grayish colour; ears a shade lighter ; under surface, and beneath
the tail, obscure ash-colour.
There are some varieties :-very rarely one is found black, others spot-
tod white and black ; one variety is an albino, white with red eyes, breeds
m conflnpment, and produces young with white colour, and the red eyes
ot the parents. ^
I
278
COMMON MOUSE.
DIMENSIONS.
r^f '■
" Tail
Height of ear
Inchet).
3*
HABITS.
V I
We have attempted to shew a portion of a shelf in a pantry, on which
stands a china jar, with its indigo-blue peaked mountains, its fantastic trees
and its (take them altogether) rather remarkable landscapes, reminding
us more of the sweetmeats it contains than of aaght in the way of nature ;
and we have also portrayed a plate, with a piece of hard old cheese in it,
on which a Mouse is standing in the act of listening, while another in the
plate, and two more on the shelf, likewise appear a little .startled, and are
expecting to be disturbed ere they can make their intended meal ; the
little rascals have reason to fear, for the careful housekeeper has heard
them of late, squealing in their squabblings with each other, has found the
marks of their teeth on the bread and butter, and is determined to get rid
of them instanter, if possible; she is calling now to her faithful pussycat,
and inquiring for the trap.
But although the thievish Mouse is often frightened, and may be said
to eat his dinner with "a cat" over his head, although he is assailed
with pokers, broomsticks, &c., whenever he unluckily runs across the
lloor, and in foct is killed as often as his death can be compassed by the
ingenuity of man, or the cunning and quickness of his ally the cat. the
Mouse will not retire from the house, and even where the supply of Ibod
for him is small, or in rooms that have long been shut up, he may be
found ; and would he let our drawings and books alone, wc should will-
ingly allow him the crumbs from our table ; but he will sometimes gnaw
into shreds valuable papers, to make a bed behind some bureau or old
chest. lie in his turn frightens man at times, and should the hard-hearted
hoarding wretch who has made gold his God, while with aged, trend)ling
hands, locked in his inmost chamber, he counts his money-bags, but hear
a little Mouse ; what a feeling of terror shoots through his frame ; despair
seems for an instant to be written on his face, and he clutches convul-
sively the metal to which he is a slave; another moment, and he recovers,
but he is still agitated, and hastily secures with locks and bolts the trea-
sure which is to him more precious than the endearments of a wife, the
love of children, the delights of friendship and society, the blessings and
COMMON MOUSE.
279
pZr "' ''' '"^' " ^'^ ^^'"'""'^ -^-« '^'' ^— i'y in his own
..OU.S ofdarkness. alone in a large old lumbering .Lse ' '' " ''''
1 he Common Mouse is a graceful, lively little animal-it is almost cm
nvorous and . a great feeder, although able to live on but liu ""1";
the supply .s scanty. This species has from four to ten young at a 1 tte
and the female suckles her young with tender care. When fir t bol rj
a.c very small, almost naked, and of a pinkish colour. The Mouse his'sev!
ral inters every year. We kept a pair in confinement. ^mIZ^ZIZ
™es. havmg fn,m four to nine in each litter. Dr. Goo.u. quo A^
t e wo «ays that "a pregnant female being shut up in a ch e'st of grt .
.n a short t,me a hundred and twenty individuals were counted "
On examuung our corn-crib in the spring, and cleaning it out"; although
n was constructed with a special view to keep off rats and vermin be ^
on posts and the floor raised from the ground some three feet, wr'bolds
outs.de mclm^ng downwards all round, we found and killei n arly fi W
M.ce_ A basket in the crib, hanging by a rope from a cros^b am n
wh.ch we had put some choice corn for seed, had been entered .yZ^:
and every gram o corn in it devoured. We found in the basket Lt h n '
but husks, and the remains of a Mouse's nest Th. • ,
therefore have climbed up to the roof of tl^c -Mnd th d ^r^edTht
core, by which the basket of corn was suspended ^^^^^"''^'1 'he
Tne activity agility, and grace of the Mouse, have made it a favourite
pet .. h the pnsoner in his solitary cell, and it has been known to anT
h.s call, and come out of its hiding places to play with the unfortunlte
Of late years white Mice have been in request in London, where they
are taugh vanous tr.cks, and are exhibited by boys in the streets. I i'
ated that m order to mcrease the number of this variety, persoas exclude
hem irom the hght, this they pretend causes a great many of them 1 L
born a bmos. We are however satisfied from personal experience "h^t a
p.urot albmos, accidentally ,.,oduced, would continue to propagate ta
net.es of the same colour without the aid of darkness; as fs the tsel
'he albino var.ety of the English rabbit.
280
COMMON MOUSE.
r.EOORAnilCAI. DISTRIBUTION.
The Common Mouse is not a native of America, but exists in all conn
tries where sliijjs liavo landed cargo, and may be said to tread ch)H<-iy on
the heels of commerce. It was Ijrouj^lit to America in the vessels tliii'
conveyed to our shores the early emigrants.
1 " i
281
GENUS UIlSU.S.—Li.m
DENTAI, KORMHr.A.
Inctstve J' Caniitf — ; Molar -- - 40
H«ad large ; body, stout, and covered with a coat of thick hair; ears
larKc .slightly acuminated. '
di.i^ir.' ''""' ' "'" '"""' '""""''"'^ '^'"' '""""^ '"'■^*"^ ^'^^«' ""^'i '»••
Tail, short; ,„amrn«^, six. two pectoral and four ventral; no glan-
dular pouch under the tail. ^
The Koneric name is derived from the Latin ursus a Bear
E.ght species or this genus have been described, three existing in
urope, one of w.ch, the Polar Bear, is common also to America, one in
URSUS MAUITIMITS.— Linn.
Polar Bear.— White Bear.
PLATE X CI. —Male,
libus ^,^^^''''''"^'''*' cranio applanato ; collo longo ; pills longis mol
CHARACTERS.
Head, elongated ; skull, flat ; neck. Ion, ; hair, long, soft, and white
SYNONY.MES.
White Bear. Marten's Spitz. Trans., p. 107. An. 1675
Ursus Mabitimus. Lin. Syst.
Ursus Aldus. Bris«on, Regno, an. p. 2G0
L'Ouns Blanc. Buffon, vol. lij, p. i28. An. 1707
I'Ksus Marinus. Pallas, vol. 3, p. 69.
Polar Bear. Pcnn. A rot. Zool., p 53.
Vol.. n. — 3(5.
m mt
281
I'OI.AK UF.VIl.
lliisua Maritimub. Piirry'^^ \>*t voy(ij»«', Su|>|>., \>. Ih;{,
luikhii s isi viivHjii', |i
tUH.
(li
iirry s yiul v(»yiij;i«, /\|)|)i'ii(lix, p. •■iHS.
Uicliiii'ilsoii, L''iiiiiiu, |). :io.
Sa)iO!*l»y's Account dI' tlii) Arctic Ucgioiia,
I i
nKHCRIPTION.
Ilciul and muzzle narrow, proloiiycd on a stniiKlit lino vvilli thd fore
IumkI, which is (latltMU-d ; snout, naUcil ; <'ars, short; ni'ck, l(in« ; hoiiy,
lon« in proportion to its hcitihl ; soles of the hind Icct ctiual to one-sixth
of the length of the body; hair, rijfid, eoinpaet and lonj; on the liody and
linihs, is from two to three inches in lentil', ^vilh a small (juaiitity of line
niid woolly hair next the skin. The whole animal wears the appearance
of great strength without much agility.
COLOUR.
The naked extremitj of the snout, the tongue, margins of the eyelids,
and the claws, are black ; lips, purplish idaek ; eyes, dark-brown ; interior
of the month pale violet. The hairs on every part of the body are of u
yellowish-white colour.
DIMENSIONS.
Specimen in the Charleston Muscimi : —
Head and body, - - -
Tai!, (vcrtebra<), - . - -
" to end of hair, . - - -
Height of ear, .....
Height from shoulil'.M-, - - - -
Girth around the body. - - - -
" around the hind leg.
Length of canine teeth,
" of incisors, ....
\Vt> api)ond tlie followini: measurements taken from specimens in the
Hesh, by Capt. .1. C. Ross, R.N., F.U.8., &c. :—
Ftst
6
3
U
I
Inclit'S.
u
10
1
.'t
3
7
If
(If
Length from snout to end of tail,
Snout to shoulder,
Snout to occiput,
Circumference bclbre the eyes,
M.M.i;.
InclU'K.
;!.■!..■)
1H.4
20.4
ki:mai.i;.
InoliuM.
7S
•jt;.;{
1 :>A>
15.8
POl.AU HEAR.
283
At hrnadf^sf part of tUo. hcid, -
At lar>,'«'st p.iil r.r 111,, jihdorncn,
I-i'iiy;(li (»r (iljiiw 'iiry canal.
VV.i-ht,
Thr wri^l.t vari.^s vrry much av.couWuK to the season und condition of
ton niiinial.
Th.. larK-'st. nirasurrd 101.5 inches in length, and weighed 1028 lbs
all hough in poor condition. '
MAI.K.
IlichM.
(I!
OOOlhs.
FEMAI.R.
lneho«
2H
rn.a
52
700|l)s.
HABITS.
We have .io„rneye,I together, friend reader, through many a deep dell
and w.id woo,!, through swamp and over mountain; vve have stemmed'
the current of the iMississippi. sail,.,| on our l.road lakes, and on the ex-
tended sea coast, from [.ai.rador t„ Mexico ; we have coursed the hu-^e
l.u lalo ov.T the wide prairies, hunted the lin.id .leer, trapped the beaveV
.-n.d ..ughl ,!.,. fox ; we have, m short, already procured, (igured, an.l des-
er.l.ed. many ol our animals; and now, with your permission, vve will
send you wUh th,- adventurous navigators of the Polar Seas, ia search of
the Wlute Bear, for we have not seen this remarkah!,. inhabitant of the
ley regions of our northern coast ami.l his native fr../.en deserts; and can
th..re(oreu,v..you little more than such information as may be found in
the works of previous writers o„ l.is babits. D,„.i„. ,„p vj,), f„ ^..^.p,,,,,,
in TN3.S, we coasted along to th,- north ;.s far as the Straits of n,.|b.islc
l.m .t l..'ing midsummer, we saw no Polar Hears, although we heard from
the settlers tl.tt these animals were someliu.es seen there; (on one
occasion, in.lcd. we thought we perc,.ived three of them on an lce-ber<r'
hut the distance was too gn-at for us to be certain), although the abundance
of seals a„d bsl, of various kinds on the shores, would have afforded
them a plentiful supply of their ordinary food. They are doubtless drifted
f.-tr to the southwanl on ice-bergs from time to time, but in our voya-^es
to an.l Irom Europe we n. .er saw any. although we have been for davs
in the ice. •''
The Polar Rear is carnivorous, in fact omnivorous, and devours with
-••inn! vora.Mty the carcases of whales, abandoned, and drifted ashore bv
• he waves; seals dead fish, vegetable substances, and all other eatable
mntters obtau.able, whether putrid or fresh. Dr. n,n,..usos, in the Fauna
Boreali Americana, has given a good compiled account of this animal, and
we shall lay a portion of it before our readers. The Dr. says:- "I
"rrjanjnp
284
POLAR BEAR.
have met with no account of any Polar Bear, killed of late years, which
exceeded nine feet in length, or four feet and a-half in height. It
IS possible that larger individuals may be occasionally found : but the
greatness of the dimensions attributed to them by the older voy.igers has,
T doubt not, originated in the skin having been measured after being much
stretched in the process of flaying."
The great power of the Polar Bear is portrayed in the account of a dis-
astrous accident which befel tlir crew ofBARENiz's vessel on his second
voyage to Waigat's Straits. "On the (ith of September, 1594. some sailors
landed to search for a certain sort of stone, a species of diamond. During
this search, two of the seamen lay down to sleep by one another, and a
White Bear, very lean, approaching softly, seized one of them by the nape
of the neck. The poor man, not knowing what it was, cried out "who
has seized me thus behind ?" on which his companion, raising his head,
said, " Holloa, mate, it is a Bear," and immediately ran away. The Bear
The rest of the persons who were on shore, to the number of twenty,
immediately ran with their match-locks and pikes, and found the Bear
devouring the body ; on seeing them, he ran upon them, and carrying
another man away, tore him to pieces. This second misadventure so ter-
rified them that they all fled. They advanced again, howev(>r, with a
reinforcement, and the two pilots having fired three times without liitting
the animal, the purser approached a little nearer, and shot the Bear in the
head, close by the eye. This did not cause him to cjuit his jjrey, for,
holding the body, which he was devouring, always by the neck, he car-
ried it away as yet quite entire. Nevertheless, they then perceived that
he began himself to totter, and the purser and a Scotchman going towards
him, they gave him several sabre wounds, and cut him to pieces, without
his abandoning his prey.
In Barentz'e third voyage, a story is told of two Bears coining to the
carcase of a third one that had been shot, when one of them, taking it
by the throat, carried it to a considerable distance, over the most rugged
ice, where they both began to eat it. They were scared from their re-
past by the report of a musket, and a party of seamen going to the place,
voured half the carcase, which was of such a size that four men had
great difliculty in lifting the remainder. In a manuscript account of
Hudson's Bfty, written about the year 1780, by Mr. Andrew Craliam,
one of Pennant's ablest correspondents, and preserved at the Ilndsoirs
Bay house, an anecdote of a different d scription occurs. "One of the
Company's servants who was tenting abroaf* to procure riil)l)its, (Lrpus
POLAR BEAR.
285
Amencanus), having occasion to come to the factory for a few necessaries
on his return to the tent passed througli a narrow thicket of willows and
found himself close to a White Bear lyin- asleep. As he had nothing
wherewith to defend himself, he took the ba- off his shouldor and held i"t
before his breast, bet^veen the Bear and him. Tlie animal arose on see-
ing the man, stretched himseif an 1 nibbed his nose, and having satisfied
his curiosity by smelling at the bag, which contained a loaf of "bread and
a rundlet of strong beer, walked quietly away, thereby relieving the
man from his very disagreeable situation."
Dr. Richardson says, "They swim and dive well, they hunt seals and
other marine animals with great success. They are even said to wage
war, though rather unequally, with the walrus. They feed likewise
on land animals, birds, and eggs, nor do they disdain to prey on carrion,
or, m the absence of this food, to seek the shore in quest of berries and
roots. They scent their prey from a great distance, and are often at-
tractea to the whale vessels by the smell of burning kreng, or the re-
fuse of the whale blubber."
The Dr. quotes Cai)tain Lyons, who thus describes the mode in which
the Polar Bear surprises a seal :_"The Bear, on seeing his intended prey
gets quietly into the water, and swims to tlie leeward of him, from'
whence, by frequent short dives, he silently makes his approaches, and
80 arranges his distance, that, at the last dive, he comes to the spot
where the seal is lying. If the poor animal attempts to escape bv
rolling into the water, he falls into the bear's clutches ; if, on the con-
trary, he lies still, his destroyer makes a powerful spring, kills him on
the ice, and devours him at leisure." Captain Lyons describes the paee
ot the Polar Bear, at full speed, as " a kind of shuffle, as quick as the
sharp gallop of a horse."
The Polar Bear is by no means confined to the land, on the contrary he
JS seldom If ever seen far inland, but frequents the fields of ice, and swims
ofl to floating ice or to ice-bergs, and is often seen miles from shore.
It is said that these animals "are often carried from the coast of Green-
land to Iceland, where they commit such ravages on the flocks that the
inhabitants rise in a body to destroy them." Captain ^^abine saw one
about midway between the north and south shores of Barrow's Straits
which are forty miles apart, although ther.. was no ice in sight to which
he could I- sort to rest himself upon. The Polar Bear is said to be able
to make long leaps or springs in the water.
This species is found farther to the north than any other quadruped,
having been seen by Captain Parry in his adventurous boat-voyage be-
yond HJ degrees of north latitude
«i
if'l
:i w
;r
ri ;
I
L'86
POLAR HEAR.
Pevnant, who collected from s:oo(l authorities much information rela.
tive to their ninge, states that th.>y are frequent on all the Asiatic coasts
of the Frozen Ocean, from the monih of the Obi eastwarl, and abound iii
Nova Zenihia, Cherry Island, Spitzb.^r-en, Creenland, Labrador, and the
coi.sts of IJaliin's and Ilu.ison's Hays. Dr. l{r.i.Au„s„N says,— "They
were seen by Captain Parry within Harrow's 8trails, as far as' Melville
Island; and the Esquimaux to the westward of Mackenzie river, told
Captain Franklin that they occasionally, though very rarely, visited
that coast. The exact limit of their range to the westward is un-
"'•rtain. but they are said not to be known on the islands in Behring's
Straits, nor on the coast of Siberia to the eastward of Tchutskoinoss.
They are not mentioned by LANnsDORFF and other visitors of the North-
west Coast of America ; nor did Captain Bki-.-iiey meet with any in hi^
late voyage to ley Cape. None were seen on the coast between the
Mackenzie and Copper-Mine River; and Penna /t informs us, that they
are unknown along the shores of the White Sea, which is an inlet of
a similar character."
Dr. UieiiARi..«oN does not think that the Polar Pe.-ir is under the same
necessity for hibernating that exists in the case of the Black Bear, which
feeds chiefly on vegetable matters, and supposes that although they may
all retire occasionally to caverns in the snow, the pregnant females alone
svclude themselves for the entire winter. In conlirmation of this idea
the Dr. mentions that "Polar Bears were seen in the course of the two
winters that Capt. Parry remained on the coast (,f Melville Peninsula ;
and the Esquimaux of that quarter derive a considerable portion of their
subsistence, not only from tlie flesh of the female Bears, which they dig to-
gether with their cul)s irom under the snow, but also iVom the males, "that
they kill when roaming at large at all periods of the winter. To this
statement is added IIearne's account ; he says :—'• The males leave the
land in the winter time and go out on the ice to the edge of the open
water in search of seals, whilst the females burrow in deep snow-drifts
from the end of Deceml)er to the end of March, remaining without food,
and bringing forth their young during that period ; that wlien they leave
their dens in March, their young, which are generally two in number,
are not larger than rabbits, and make a loot-mark in the snow no bigger
than a crown piece."
'• In winter." says Mr. (Irauam, "the White Bear sireps like other species
ofthegeniis, but takes up its residence in a, dilferent situation, g(.|ierally
under the declivities of rocks, or at the foot of a, bank, where the snow
drifts over it, to a great d.'pth; a small hole, for the adrnissioa of fresh
nir, is constantly observed in the dome of its den. This, however, has
POl^R BEAR.
287
regard solely to the she Be-.r, which rc^tires to her" winter-quaiters in No-
vember, where she lives without I'ood, l)riiigs forth two young about
Christmas, and leaves the den in the month of March, when the cubs arc
as large as a shepherd's dog. If, perchance, her ollVpring are tired, they
iiscend the back of the dam, v/herc they ride secure either in water or
ashore. Though they sometimes go nearly thirty miles from the sea in
winter, they always come down to the shores in the spring with their cubs,
where they subsist on seals and sea-weed. The he Bear wanders abouf
the marshes and adjacent parts until November, and then goes out to the
sea upon the ice, and preys upon seals."
The Esffuimaux account of tiie hibernation of the Polar Bear is curious:
it was related to Capt. Lyons by one of their most intelligent men, re-
joicing in the euphonious name of (Mr.) Ooyarrakhioo ! and is as' fol-
lows :— " At the commencement of winter the pregnant bears are very fat,
and always solitary. When a heavy fall of snow sets in, the animal seeks'
some hollow place in which she can lie down and remain quiet, while the
snow covn-s her. Sometimes she will wait until a quantity of snow has
fallen, and then digs herself a cave : at all events, it seems necessary tha.
she should be covered by, and lie amongst, the snow. She now goes to
sleep, and does not wake until the spring sun is pretty high, when she
brings forth two cubs. The cave by this time has become much larger
by the effect of the animal's warmth and breath, so that the culw have
room to move, and they acquire considerable strength by continually suck-
ing. The dam at length becomes so thin and weak, that it is with great dif-
ficulty .she extricates herself, when the sun is powerful enough to throw a
strong glare through the snow which roofs the den." The Esquimaux
aflirm that during this long confinement the Bear has no evacuations, and
is herself the means of preventing them by stopping all the natural'pas
sages with moss, grass, or earth. The natives find and kill the Bears
during their confinement by means of dogs, which scent them through the
snow, and begin scratching and howling very eagerly. As it would be
unsafe to make a large opening, a long trench is cut of sufficient width to
enable a man to look down and see whore the bear's head lies, and he
then selects a mortal part, into which he thrusts his spear. The old one
neing killed, the hole is broken open, and the young cubs may be taken
out by the hand, as, having tasted no blood, and never having been at
liberty, they are then very harmless and quiet. Females, which are not
pregnant, roam throughout the whole winter in the same manner as the
males.
The Polar Bear is at certain seasons and under peculiar circumstances
d dangerous animal. Like tlar Grizzlv Bear it possesses both strength
ii! iri
^ !*
288
POLAR BEAR.
and activity enough to render it ai all times formidable. Although, like
all Bears, it appears clumsy, can run with great swiftness either on the
ground or on the ice, and it can easily ascend the slippery sides of ice-
bergs by the assistance of its claws, being in the habit of mounting on
their ridges and pinnacles to look out for food or survey the surrounding
fields of ice.
When in confinement, the great strength of this Bear is sometimes r.iani-
fested to the terror of the spectators. One that was secured in a cage
fronted with rods of inch iron, bolted into a horizontal flat plate of the
same metal, several inches wide, near the bottom, and well fastened at
top, in the stout oak boarding of which the cage was constructed, one day
when we were present became enraged by the delay of his keeper in
bringing his food, and seized two of the rods with such a furious grip that
one of them bent and instantly came out, when the huge beast nearly
made his escape, and was only prevented from succeeding by the prompt-
ness of the attendants, who instantly placed the wooden front, used when
travelling, on the open part of the broken cage and closed it effectually
This Bear, like all others we have seen caged, was very restless, and
would walk backwards and forwards in his prison-house for hours to-
gether, always turning his head toward the bars in front, at each end of
this alternating movement, and occasionally tossing his head up and down
as he walked to and fro.
Many anecdotes are related of accidents to the crews of boats detached
from whaling vessels to kill the White Bear, and by all accounts it appears
to be exceedingly dangerous to attack this animal on the ice. One of
these accounts, with others of a different character, we will repeat here,
Dr. ScoiiESBY tells us, that " a few years ago, when one of the Davis's
Strait whalers was closely beset among the ice at the ' South-west,' or on
the coast of Labrador, a Bear that had been for sometime seen near the
ship, at length became so bold as to approach alongside, probably tempted
by the offal of the provision thrown overboard by the cook. At this time
the people were ail at dinner^ no one being required to keep the deck in
the then immovable condition of the ship. A hardy fellow, who first
looked out, perceiving the Bear so near, imprudently jumped upon the
ice, armed only with a handspike, with a view, it is supposed, of gaining
all the honour of the exploit of securing so fierce a visitor by him.self. But
the bear, regardless ot" such weapons, and sharpened probably by hunger,
disarmed his antagonist, and seizing him by the back with his powerful
jaws, carried him off with such celerity, that on his dismayed comrades
POLAR BEAR,
289
rising from their meal and looking abroad, he was so far beyond their
reach as to defy pursuit."
An equally imprudent attack made on a Bear by a seaman employed in
one of the Hull whalers, was attended with a ludicrous result. "The
ship was moored to a piece of ice, on which, at a considerable distance, a
large Bear was observed prowling about for prey. One of the ship's com-
pany, emboldened by an artificial courage derived from the free use of
rum, which in his economy he had stored for special occasions, undertook
to pursue and attack the Bear that was within view. Armed only with a
whale-lance, he resolutely, and against all persuasion, set out on his ad-
venturous exploit. A fatiguing journey of about a half a league, over a
yielding surface of snow and rugged hummocks, brought him within
a few yards of the enemy, which, to his surprise, undauntedly faced him,
and seemed to invite him to the combat. His courage being by this time
greatly subdued, partly by evaporation of the stimulus, and partly by the
undismayed and even threatening aspect of the Bear, he levelled his lance
in an attitude suited either for offensive or defensive action, and stopped.'
The Bear also stood still ; in vain the adventurer tried to rally courage to
make the attack ; his enemy was too formidable, and his appearance too
imposing. In vain, also, he shouted, advanced his lance, and made feints
of attack ; the enemy, either not understanding, or despising such unman-
liness, obstinately stood his ground. Already the limbs of the sailor began
to quiver ; but the fear of ridicule from his messmates had its influence,
and he yet scarcely dared to retreat. Bruin, however, possessing less re-
flection, or being regardless of consequences, began, with audacious bold-
ness, to advance. His nigh approach and unshaken step subdued the
spark of bravery, and that dread of ridicule that had hitherto upheld our
adventurer ; he turned and fled. But now was the time of danger ; the
sailor's flight encouraged the Bear in turn to pursue, and being better
practised in snow travelling, and better provided for it, he rapidly gained
upon the fugitive. The whale-lance, his only defence, encumbering him
in his retreat, he threw it down, and kept on. This fortunately excited
the Bear's attention ; he stopped, pawed, bit it, and then renewed the
chase. Again he was at the heels of the panting seaman, who, conscious
of the favourable effects of the lance, dropped one of his mittens ; the
stratagem succeeded, and while Bruin again stopped to examine it, the
the Bear resumed the pursuit with a most provoking perseverance, except
when arrested by another mitten, and finally, by a hat, which he'tore to
shreds between his teeth and paws, and would, no doubt, soon have made
the i!!!^■uJtious adventurer his victim, who was now rapidly losing strength
vol.. 1? — ni
290
POLAR BEAR.
but for the prompt and well-timed assistance of hia shipmates— who, oh
serving that the affair had assumed a dangerous aspect, sallied out to his
rescue. The little phalanx opened him a passage, and then closed to re
ceive the hold assailant. Though now beyond (he reach of his adversarj-,
the dismayed fugitive continued onwards, impelled by his fears, and never
relaxed his exertions, until he fairly reached the shelter of his .ship. The
Bear once more came to a stand, and ibr a moment se > r ' • ;':rvey his
enemies with all the consideration of an experienced g^iK len, find-
ing them too numerous for a hope of success, he very \s .,oiy wheeled
about, and succeeded in making a safe and honourable retreat."
Several authors speak of the liver of the Polar Bear as being poisonous.
This is an anomaly for which no reason has yet been assigned ; the tact
seems, however, well ascertained. All the other parts of the animal are
wholesome, and it forms a considerable article of food to the Indians of the
maritime Arctic regions.
The skin of the Polar Bear is n valuable covering to these tribes, end is
dressed by merely stretching it out on the snow, pinning it down, and
leaving it to freeze, after w'hich the fat is all scraped o(f. It is then gen-
erally hung up in the open air, and " when the frost is intense, it dries
most perfectly ; with a little more scraping it becomes entirely dry and
supple, both skin and hair ^„-..g beautifully white." " The lime of the
year at which the sexes seek each other is not positively known, but it is
most probably in the month of .luly, or of August. IIkarni;, who is an
excellent autliority, relates that he has seen them killed during this season,
when the males exhibited an extreme degree of att.cchment to their com-
panions. After a female was killed, the niiile placed his lore-paws over
her, and allowed hiiTiself to be shot rather than relinquish her dead body."
*• The pregnant females during winter seek shelter near the skirt of the
woods, where they excavate dens in the deepest snow-drifts, and remain
there in a state of torpid inaction, without ibod, from the latter part of
December or early in January till about the end of March ; they then
relinquish their dens to seek food on the sea-shore, accompanied by their
cubs." — GuDMAN, Vol. I., pp. 152, 153.
The affection of the female Polar Bear for her young is exemplified
by several stories in the Polar voyages. Scoresby says, "a she Bear
with her two cubs, were pursued on tlie ice by some of the men, and w«>re
so closely approached, as to alarm the mother ibr the safety of her off-
spring. Finding that they could not advance with the desired speed, she
used various artifices to ur;;c them forward, but without success. Deter-
mined to save them, if pos9il)le, she ran to one of the cubs, placed her nose
under it, and threw it forward as far as possible ; tlien going to the other,
POLAR BEAR.
29J
sh. performed the same action, and repeated it frequently until she h.A
thus conveyed them to a con.sideral.le distance The vol; n
m.g . rece.ve ,l,e full H,lv„„„„e „r,l,e fore, ,xe«cd Cor ,h 'J « .."'^
Capt. J. C. Ross states in regard to this snecies • " n.,.;
At that time we were fortunately in no winf ,.f n. • • u
our party, tempted by the fine ^Ve^Z^: ^fZT:;^^' T ""'
meal off the first one that was sho All th.t n 7 T r ^ ^''"'*^'
plained of a violent headache vvh i'ch t ' '' """ "'^'^'" ''""•
days, and was followed bv 'si ipl; ! 7;;;"'"^ T^" ^ ''^^^
and in some who had probably part!.:: m'o f , .^ ^t^;:" ' ^1 TT '
On a former occasion I witnessed a .somewha sfm .'.r o "'''•
on Sir Edward Parry's Polar Journey. ^..^t^^lZ^r' "^7
.... two Bears that were shot, the skin Peeled off the f' T ' '^'
many of the party. It was then attribute .1 .r* "' " T' "'"
quality of the meat, and to our havin^tel" 1 -n , "" ' ''"" ""
.hort allowance of provisions. Th E , T^ t7T'""r " ^'^^^'
periencins any such inconvenience but tir iv "'"''°"' '^''■
do.s, and that may possibly be tL ^^ ' l''^ ^7;^"'-" ^ ^•-
Boothia Felix killed several durin^ their stav i ' • f ^*^"™'^"^ «'
1830. all males." ^ '" '"'•" "^'ghboi'-rhood in
CEOCRAPinCAL DISTRIBUTION.
n..d Snitzberffen In Am...; ■/• . ' " ^ "'"'""'''^ '" ^«^'a Zembia
the coLts oi^:fii„; t: r:; t: '"S'^^"-""^"' '^"^•^''^- -^^ «-
the islands in Behring's Str!uts. ' ' "'"^ ""'' '"^ ^^ ''"""^ «"
f
1j ^'
V >
'I
^1
292
POLAR BiiAR.
McKensib informs us that these animals are unknown in the White Sea,
or on the coast of Siberia to the eastward of Tchutskoinoss. They have
been seen on floating icebergs from fifty to a hundred miles at sea. Capt.
Ross states that this species was found in greater numbers in the neigh-
bourhood of Port Bowen and Batty Bay in Prince Regent's Inlet, than '<"
any other part of the Polar Regions that were visited by the several ex-
peditions of discovery. This he supposed was owing to the food thry
were enabled to procure in that vicinity, Lancaste. Sound heing but sel-
dom covered by permanently fixed ice, and therefore affording them means
of subsistence during the severity of an arctic winter, and also from its
being remote from the haunts of the Esquimaux.
I
298
LYNX RUFUS-VAIl. MACULATUS.-Hqrspield and Vigors.
Texan Lynx.
PLATE X C 1 1 .—Feraalo.— Winter pelage.
L. rufo-grisea, dorso saturatiore, corporis lateribus memberisque externe
bruneo-maculatis, guiii, corpore infra, membrisque intern^ albis, bruneo
latius maculuti auribus pencillatis.
C»ARACTER8.
Brownish-gray on the upper surface, sides of body and outer surface
of legs, with small brown spots; under surface of body and inner surface
of legs, white, broadly spotted with brown ; ears, pencilled.
synonymes.
Fklis Maoulatos. Ilorsfield and Vigors.
" " Zoological Journal, vol. 4, p. 380.
** " Reichenbach, Regnum Animale, vol. 1,
0, pi. 37.
DESCRIPTION.
In size, in shape, in its naked soles— in the form of the skull— the dispo-
sition and character of its teeth, and in all its habits, this species is so
much like the Bay Lynx, (L. rufus,) that were it not for the different shades
of colour, and the peculiar markings of some parts of the body, no
naturalist would have ventured to describe it as a new species. One of
the characters given to this supposed species by its original describers is
that of pencilled ears ; this character, however, exists also in the Bay
Lynx ; in both cases these hairs drop out when the other hairs are shed
in spring, and are not replaced till the following autumn. The same pe-
culiarity exists in many of our American squirrels. There is, as in L.
ra/Ms, ashort ruff under the throat of the male. The hair is of two
kinds : the inner, fine, and the outer and longer, not very coarse, and the
fur, although much shorter, is fully as fine as that of specimens of th(!
Bay Lynx obtained in Pennsylvania and New- York.
JOLOUR.
The hairs on the back are at their roots yellowish-white, gradually
becoming light-yellow, which colour continues tor three-fourths' the lenglli,
when they are barred with brownish-black, then yellowish-brown, tipped
with black ; on the sides, the hairs are tipped with whitr • on the und -t
> i|
I"!
294
TEXAN LYNX.
11^
surface, they are white thron;,'houf, with a shade of pale-yellow at the
base. Where black spots exist on the body, the hairs are less annuiatcd
— are dark-browu at the roots, deepening into black ; and in some spots
on the sides, and the bands on (he tail, the hairs are pure black from the
roots.
Moustaches, white ; around the nose, around the eye, and cheeks, pale
lawn colour; lips white; forehead, obscurely and irregularly marked with
longitudinal Mripes of dark-brown on a light-yellowish ground-colour.
There are two black lines commencing at a point on a line with the
articulation of the lower jaw, where they Ibrm an acute angle, div^-irging
from thence to the sides of the neck, and unite with the rulf, where it is an
inch broad. The ears are yellowish-white on the inner surface, black on
the outer, with a broad white patch in the middle, including nearly their
whole breadth. The slight pencil of hairs at the extremity of the ear is
black ; on the back the colours are waved, and blended with obscure
yellowish and brown spots — assuming on the dorsal line slight indications
of narrow longitudinal stripes. The feet, on the uppt surface are dottod
with small brown spots; on the under surface the ground colour is whitish
with irregular patches of black. This is more especially the case on the
inner surfaces of the thighs and fore legs, which present long stripes
and patches of black, somewhat irregularly disposed. The tail is white
on the under surface, barred above with rufous and black; towards the
extremity there is first a bar of black about one-third of an inch wide, ther
brownish-gray, then an inch of black ; the white on the under surface
rises above the black, making the tip of the tail white.
DIMENSIONS.
Male.— Weiglif 2r> lb.
Feet. Iiiuhei
End of nose to eye, - - - 2
" " to burr of ear, - 4f
BetAveen ears, ... - 3^
Nose to crown of head, - - 5j
" to root of tail, - - - 2 9
Tail (vertebra') - . . 7
to end of hair, - 7^
Hind legs (stretched) beyond tail, 1 1^
Fore " " beyond nose, (S^
Height of shoulder from ground, 1 7^
Round body behind shoulder, 1 1^^
" at the loin, - 1 4j
Female. — Weight '
F«)t.
20 lb.
Inches,
.i
Si
r>
(>
10
c
n
TEXAN LYNX
go.*)
HABITS.
TIlis variety of Lynx may be called the Common VVild-Caf of Texas,
where it i.s occasionally found even on the prairies, althou-h it generally
confines itself to the nei-hl.ourhood of woods and ctiaparal.
The Trxan Wilrl-Cat is. like the Ay»r , •,;/■«., a wily and audacious depre-
•iator-he steals the fowls from the ne« ly-estahlished raiidio, or petty
liirm ; Ibllows the hares, rats, and birds, and springs upon them in th.. tall
rank grass, or thick underbrush, and will sometimes even rob the ranker
of a fine turkey ; for should the Wild-Cat be lurking in the dense thicket,
when the crack of the rifle is heard, and the wild gobbler or hen fulls
slanting to the earth, he will, instead of (lying with terror from the
sfarllmg report of the gun, dart towards ti.e falling bird, seize it as it
touches the ground, and bear it off at full speed, even if in sight of the
enraged and disappointed marksman who brought down the prize. In
general, howeve.-, the Southern Lynx (as this species is sometimes called)
will fly from man's presence, and will only come abroad during the day
when very hard pressed by hunger, when it may be occasionally seen near
l.ttle thickets, on the edges of the prairies, or in the open ground, prowl-
u.g with the stealthy sneaking gait observed in the domestic cat, when
snnilarly employed. This species of Wild-Cat is better able to esci.pe
from an ordinary pack of dogs, than the Common Lynx, being accust<.med
to the great distances across the high dry prairies, which it must fre-
<|uenfly cross at full speed. We have known one chased, from 1 1 o'.Ioek"
in the morning till dark nigh), without being "treed." The animal, in
fact, prefers running, to resorting to a tree at all times, and will not
ascend one unless it be nearly exhausted, and hard pressed by the hounds
GEOGRAPIltCAL DISTRIBaTION.
This variety of the Bay Lynx is believed to exist throughout Mexico-
we have seen specimens, obtained in that country, in several xMuseums of
Carope. especially those of R.-rlin and Dresden ; in the latter, the specimen
described and figured by Re.chf.nbac,, is preserved. His figure, however
which we have compared with the original, is likely to mislead'; the le-s
and tail being much too long. It exists in New Mexico, and we have
heard that a Wild-Cat, supposed to be the present varierv, is found in
California. The specimen from which our drawing was made, was pro.
cured with several others by John W. A.dubon, in the vicinity of Castro,
ville, on the head waterr. of the Medina, in Texas ; we possessa specimen
li
i>90
TEXAN LYNX.
nearly of tlie same markings, procured by our deceased friend, the late
lamcntoJ Dr. Wuruemann.
OENERAI. REMARKS.
W(! linve admitted this ns a variety of the Buy Lynx with some doubt and
hesitation, iuul not without niist^ivinj,"< tiiat it might yet be proved to be a
distinct species. The permanency of its colours, together with the smaller
size of our specimens, and their sotYer fur, may afford sufficient characters
to entitle it to the namt; of Muculatus, as given by HoRtiiEFiEM) and Vigors.
Aware, however, of the many varieties in the Bay Lynx, we have not felt
aiitliurised to regard it as positively distinct.
I
lend, the late
>me doubt and
•roved to bo ;i
sh the smaller
;nt characters
-I) and Vigors.
' have not felt
'fl
' '' m^
\ .
\
\
^'
\ .
\
\
^'
297
PUTORIUS NIGRIPES.-AUD. and Bach. '
Black-Footed Ferret.
PLATE XCIII. — Male.
P. Magriitudine mustelam martem equans, fronte, caudse, apice, pedi-
busque uigris; supra e flavido fuscus infra albus.
CHARACTERS.
Size of the pine marten; forehead, feet, and extremity of tail, black}
yellowish-brown above, white beneath.
SYNONYME.
FuTORius NiORiPEs Aud. and Bach, Quadrupeds of North America, vol. 2
pi. 93.
DESCRIPTION.
In its dentition this species possesses all the characteristics belonging to
putorius and from the number and disposition of the teeth, cannot be
placed in the genus, mustela. The canine teeth are stout and rather long,
extending beyond the lips; they are slightly arched and somewhat blunt;
the two outer incisors in the upper jaw are largest, the remainder are
smaller, but regular and conspicuous. The first false molar is small but
distinctly visible, it is without a lobe ; the second is larger and has a
slight lobe on each side. The great tuberculous tooth has two points and
an external lobe ; the last molar is rather small. In the lower jaw the
incisors are small, and much crowded together. The three false molars
on each side increase in size from the first, which is smallest and simple,
to the third, which is largest and tuberculated. The great internal tooth
lias three lobes but no tubercle on the inner side, as is the case in the
genus mustela ; the last, or back tooth, is small but simple.
short ; eyes, of medium size ; moustaches, few; ears, short, erect, broad at
base, and triangular in shape, clothed on both surfaces with short hair ;
neck, long • legs^, short and stout ; toes, armed with sharp nails, very
slightly arched ; the feet on both surfaces covered with hair even to the
soles, concealing the nails.
vol.. ii.— .3f!
'Jl»6 «L\t"K K<H)Ti:i) rKUllKT
The pfliiKc is of two kimlH of Ii.iir, ii is sli(.it soli „iul very (im-, llu-
outrr iiiid inl.Tsprrsod luiirs miv iio( ho (iii,<. hut ;mv iiol lon^' mid v.-ry
rours... Tlu- fur is IIm.t tli.in llial ..t llu- inink ,.r pinr niiul.-n, m.d rv.n
sl.orl.-r tl.Hti that of t\w vnn\uv. Tli.. lu.i.s hHow ll,,. r,iis, un.l,..- iIm>
lorraniis miuI l„.||y :.,r llu- .•...•usrM ; ||u, ,„il is o> lin.lrir.il, and Irss
vliMMinoiis ll.iu.lhal of (1... u.ink. .•onlaiuiri- .noro. roarso hair, and l,.,ss
line fur, than in that aniiniil.
«'01, (It'll,
Thr Iouh: hairs on tho ha,-i< an- at tho roots ^^•l.itish, will, a vllowish
t.nv:.-. broadly ti|.,„-d uitl. lo.l.lish-l.rovv.i ; tho soft uimNt fur "is uhitr
Nvith a yrilowish liiif^^s oivini,' llu. animal on Iho hark a v.dlowish.
!.roun ap|,..ura,i.-,., in son.o parts apj.roarhin^. 1., rufous; o„"tl,r suU'h
■•""'■■"•"l> lh<M-olouris;,|ittlo li.ht,-r, ^M'adually lh.lin« into yrllowisl,.
whil... Wliisk.M-.. whit., aii.l hla.k; nos,-, rars, si.l.vs of fn',,, ,|„.„at
•■•uI.T surf,.,.,- of „,.,.k. h.lly.aiid u,i,|..r snrfa..,- of tail, whit,., a slia.lo'
»l brownish on Iho oh.-st h.-tw,-,, Iho fon-h^^s. Tiar,. is a hro.u! hla.-lc
patc-h c-omnn-noinf,' on th,- for.h,.a,l. rn.-losin^^ Iho .-v,.s. an.i running ,lown
within ,i (,.w lin,.s of llu- pointof th,- n,.s,- ; out,.r and inn,-r surfa.-.-s of
tin- 1,.^'s. to n,.ar tlu- shouhh-rs aii,I hips, hla,.k, will, a tin^,. of brownish
the dp ol the tuil is bhiok, f,.r two iii,.h,.s iVoni th,- ,-xtirinily.
DIMENSIONH.
From point, of nose to root of tail,
Tail, (vert, bra.)
]i,-ail to ,-ii,l of hairs
H,-i>iht of ear |)ost,-ri,)rly,
I'roiii shoulder to end of lore leir.
IIAHITS.
f^Mt, lllcllM.
1 7
4
4
It IS with sreat pleasure that we intnuluee Ibis handsome new
speeu-s; ,t was proeur,,! by Mr. C,„.,„.;ktson on llu- Iow,.r wat,.rs of
ll"- I'latt,- |{iv,.r. a.ul inhabits the woo,l,.,| parts of th,- ,.oui.try to th,-
Kocky Moi.ntains, and p,i-!.apsis Ihun,! b,-yon,l that ran-,., aitlu.unh ,u,t
ohserve.l by any lrav,.||,.rs, fnun Lr.uis an,! Clakk to llu- pr,.s,.,^, day
When we consi,I,.r the v.,.y r.^ inai.n,.r in whi,.), ev,.ry exp,.,liti,;u
that ha. er,>s.,.,l the Roeky Mo.iMtains,haH h,.en push,.,! lorward, w,. ,-an-
not wonder ihat many sp.-ci.-s hav,. h,.,-.. entiivly ov,.rl,.,.k,.d, an,! shoul,!
rather be surpiis.,! at tla- nmnber notict,! by Lvvis and Clark, a..,l l,y
ni,ACK.F()OTi;!) rKllRET.
299
NiiTAU,, TowNSiiNo. and ollicrs. Tlinv lins nrv.-r y(-t, hron a CJovrrmnciit
rxpcdiiioii |,i„|„.,ly ()r«;iiiti/.c(l, and sent, lorlh lo ohiaii, all tli,. dctiiils,
which Mich II jKirly, iillowcd limr <>ii(iiiy:h iWr (lioroiij^di iiivcsli«ali<,n,'
would iiiid.ml.lfdly hriiijr |,.„.i(^ concciiiiMy; llic nafuml hinlory ;iiid'
natural i-rsomvcs „r the rcKi.Mis oC the far west. '\\v. nearest, appn.acli
to such an cxpcdiliop having Ium-u tliat. so well conducted hy Lkwis and
Cakk. Nor do %v.' think it at all pnihal.Io that Clovernment, will attend to
such inatL-rs lor a l.aiK ti,„„ (,<, ,,„„„.. We must, tlierelbre hope that,
privalo enterpriNe will Kradually unlold tin, /.(HdoKicml, botanical, and
mineral wealth of the iiniiKMise territorieH wo own but, do not, y.il, ocoui)y.
'i'h.^ habits of this speei.>s res.-niblc, as Car as w.^ have learned, tho.sc of
llie ferret, „f lOurop,.. ||, (c.mIs <,i, birds, small reptib.s and animals, ,.g«H,
and various insects, and is a bol.l an.l cunniuK foe to Iho rabbits, hares,
grouse, and other f>:atiie of om- wc-stera rej^ions.
'i'he specimen from whicdi wo made our drawinj? was rcceivod by us
IVom Mr. J. C. |{K.i.i,,to whom it was forwanhul from tlie outskirts «r out-
posts of the fur traders on the IMatte river, by Mr. Cmikrthon. It was
stuire<l with the wormwood so abundant in parts (,f that country, and was
rather a poor specimen, althouKli in tolerable preservation. Wo shall
have occasion in a future .irlicle l<» thank Mr. Mhi,,, for tho uho of other
new specimeas,this b,;inK only one of several instances of his kind ser-
vices to us, and tho zoology of our country, in this way manifested.
OBOaBAPIIICAL DierUIIUJTION.
As br'ibre stated, tho specimen whird. wo havo flfrurod and described
was obtaiiwd on the lower waters of the I'latto river. Wo arc not awaro
that another .specimen exists in any cubinot
800
LEPUS NUTTALII.-Bacman.
Nuttal's Hare.
PLATE XCIV.-Males.
L. parvus, supra fuscus cum aurco mistus subtus dilute flavo-canescens
auncuLs ampl.s rotundatisque, cauda longiuscula, subtus albus. '
CHARACTERS.
Small ; tail of moderate length, general colour above, a mi.rture of li^ht
l^Hfr<n,UMbrou,n, beneath, light yeUo.ish grey ; ears, broad and rln^.
lower .mrjacc of the tail white. '
DESCRIPTrON.
The anterior upper incisors are more rounded than those of the Ameri-
an rare, but m the deep longitudinal furrows, and in other partrcZs
theybearastrdcu,.resemblanceto .hose of that species; the access v
upper u.c.sors resemble those of the H.^-es in ,.nj. The lo J ^^Js'
are —thu,ner than those of the American Hare, and lil.e the upp"
or of an oval shape. The upper grinders are furrowed longitu.lina llv
.ke those of other Hares, and have a slight furrow on the inner sid b [
not more apparent than in Lepns a.natiens ; indeed, all the Ame ican
Hares have th.s furrow, which differs considerably in individuals belong-
ing to tne same species. ^
This Hare bears some resemblance to the young of Lepus syUaticus ;
he forehead .s more arched, and there is no depression in tl e fronta
bone, as m the American Hare ; its fur is abo much softer, an., .iiffers Tn
colour ; the whiskers are nearly the length of the head. The ears appeared
rather short and shnvelle.I in the dried specimen, but when moist ed fo
purpose of havmg a drawing of them made became much distended ;
the mcurvation on their outer margin was as distinct as in other Hares
beanng no resemblance to the funnel-shaped ears of the ;./.. The tail
in the hvmg animal must be conspicuous, although in the dried specimen
. IS conceaed by the long fur of the posteriors. The feet arcthic" y
clot ed with soft hair, completely covering the nails. There are fiv to s
on the fore and four on the hind feet.
COLOUR.
Teeth, yellowish white ; whiskers, white and black ; the former colour
NUTTAF/S HARK
301
prrdominafinR; tlin whole of llic upper siirCacn of the body, a mixture of
huir.'uul (lark brown ; under siirlaci^ IIkIiI l)u(i'->^rey. The Cur on tin; hark
is, lor three-fourths of its Ieii;,Mh from liie roots, phuiilx'ous, liien ii;;lit,
ash mixed with hulf; and the long interspersed hairs are. all tippc'd with
black. The ears are pretty well eiotiied, internally and <'xternally, with
hairs of an ash colour, bordcu-ed with aline of black anteriorly, and edged
with while. From behind the ears to the back, tlien; is a very broad
patch of buir, and the same colour, mixed with rufus, pnsvails on the
outer surface of the legs, extending to the thighs and shoulders, 'i'lie soles
of the feet arc yellowish l)rown. The; claws, which are slightly arched,
are light brown for tliree-fourths of their length, and are tii^ped with
white ; under surface of the tail, white.
DIMCNSIONH.
Tjcngth from point of nose to insortion of tail,
" of Ileiii,
" Fur on the back, ....
Tleif^iit of ear, .-.-..
Tail vertcbraj, .--..•
lucludiiig fur, - • . • •
(iichn*.
H
2
3
H
4
nAnrrs.
The only information which we have been able to ol)tain of tlie habits
of this diminutive species is contained in the following note from Mr.
NiirrAi,, which accompanied the specimen.
" This little Hare we met with west of the Rocky Mountains, inhabit-
ing thickets by the banks of several small streams which flow into
the Shoshonee and Columbia rivers. It was freiiuentiy seen, in the avcu-
ing, about our encampment, and appeared to possess all the habHs of the
Lcpus Si/lvuticus.^*
nEOGRAnncAi, nisTRinuTioN.
We have not heard of the existence of this Hare in any part of Cali-
fornia, or New Mexico; and although it is doubtless found in other locali-
ties than those mentioned above, we cannot venture to assert that it is
widely distributed
S.il
302
NUTTAL'S HARE.
ORNERAt- REMARKS.
We described this species from the only specimen we have had an op-
portun.ty of examining. It would be satisfactory to be able to investi-^tte
lurlher, as ,t needs more information than we have been able to obt^.in
t.> pronounce decidedly upon its characters, and give its true geographical
ujstnbution. o o r
308
MUS (CALOMYS) A U R E L U S .— Aud. ano Bach
Orange-Coloured Mouse.
P L A T E X C V,— Male and Females.
M. supra saturate lutcas infra pallide flavus ; auriculis longis, cauda
corpore curtiore.
CHARACTERS.
Ears long; tail shorter than the body; bright orange-coloured above,
light buff beneath.
DESCRIPTION.
This species bears a general resemblance in form to the white-footed
Mouse, {Mas leucopiis.) It is, however, a little larger, and its ears rather
shorter. Head, long ; nose, sharp ; whiskers, extending beyond the ears.
Fur, very soft and lustrous. The legs, feet, and heels, clothed with short,
closely adpressed hairs, which extend beyond the nails ; ears, thinly
covered with hairs, which do not entirely conceal the colour of the
skin ; mammae, four ; situated far back.
COLOUR.
Head, ears, and whole upper surface, bright orange ; the fur being for
three-fonrths of its length from the roots, dark plumbeous ; whisLrs,
nearly black, with a few white hairs interspersed ; tail, above and be-
neath, dark brown ; throat, breast, and inner surface of the forelegs
white ; belly, light buff. There are no very distinct lines of separation
between these colours.
i
ii
DIMENSIONS.
" Tail, - . • -
" Ear posteriorly,
" Tarsus, including nail,
Indies.
4
3
1
Lliius
3
1
3
3
9
I) ■
ll!
304
ORANGE-COLOUR KD MOUSE.
HABITS.
In symmetry of form and brightness of colour, this is the prettiest spe-
cies of Mas iiihiibitins our country. It is at the same time a great
climf)er. VVe have only observed it in a state of nature in three in-
stances in the oak forests of South Carolina ; it ran up the tall trees with
KH lit <'if>;ility, and on one occasion concealed itself in a hole (which ap-
parently contained its nest,) at least thirty feet from the ground. The
specimen we have described, was shot from the extreme branches of an
oak, in the dusk of the evening, where it was busily engaged among the
acorns. It is a rare species in Carolina, but appears to be more common
in Ccorgia, as we received ii-om Major Lu C(jnte, three specimens obtain-
ed in the latter State.
GEOGRAPIUCAL DISTRIBUTION.
Wo found this species in Carolina, where it is rather rare ; we also ob-
tained specimens from C.orgia; we have no doubt but further investiga-
tion will give it a more extensive geographical range.
GENERAL REMARKS
We have arranged this species under the sub-genus of Mr. Wateriiousb,
proposed in the Zoological Society of London, Fcl*. 17th, 1837, (see their
transactions.) It is thus characterized; "Sub-genus Cnlumtjs, (from K«A<.t
bcaufifr.l and mas.) Fur. moderate, soft; tarsus almost entirely clothed
beneatii the hair. Front molar, with threes indentations of enamel on the
inner side, and two on the outer; and the last molar with one on each
side. The type mus {ralomys,) himiivuJatus. Two other species hrm
l)fen described, Irom South America; mus {culomys) ehgans, and
m. 'jrifiiijies.
805
PELIS CONCOLOR.— Li«fl
The Cougar. — Panther.
PLATE XCVI.—Malk:— PLATE X C V 1 1 .— Female and youko.
F. immaculata I'ulva; auriculis nigricantibus, cauda elongate, apice
nigra neque floccosa.
CHARACTERS.
Uniformly tawny-yellow; ears, blackish behind; tail, elongated, apex
black, without a tuft,
BYN0NVME8.
St ^l
Felis Concolob, Linn. Syst. Nat., ed. Gmel., 1. p. 79.
Schreb Saugth., p. 394.
BufTon, Hist. Nat., t. 9.
Gonazouara, D'Azara Anim. du Paraguay.
" " Desmaiest in Nouv. Diet., p. 90, 2.
Puma, Leo Americanus, Hernandez.
F. CoNcoLOR, Cuv. Regne Animal, vol. 1, p. IGl
BiiowN TiQEH, Pennant's Syn. p. 179.
Black Tioer, " " 180.
F. Concolob, Harlan, Fauna Am., p. 94.
" " Godman, vol. 1, p. 2i»l.
Dekay's Nat. Hist. N. Y.. p. 47.
DESCRIPTION.
Body, long and slender ; head, small ; neck, long ; ears, rounded ; legs,
short and stout ; tail, long, slender and cylindrical, sometimes trailing ; fur,
soft and short.
COLOUR.
II
ill
i
Body and legs, of a uniform fulvous or tawny colour ; under surface,
reddish- white; around the eyes, grayish-yellow; hairs within the ears,
yellowish-white ; exterior of the ears, blackish ; lips, at the moustache,
black ; throat, whitish ; tail of the male, longer than that of the female
bcown at tip, not tufted.
VOL [I. — 30.
I.I
r t
■ P:
i
l»
If I
306
COUGAR.
Wp have seen several specimens .lilTcring (rom the above in various
shades of colour. These accidental variations, however, are not sufficient
to warrant us in rejrardmsf these individuals as distinct species.
The youn- are beautifully spotted and barred with biaciiish-brown, and
their hair is soil and downy,
DtMENBIONS.
Male, shot by J. W. Audubon, at Castrovillc, Texas 28th Janur.ry, 1846.
From point of nose to root of tail
'I'ail ....._
Height of ear posteriorly - - . .
Length of canine teeth, frouj gums
Female, killed 2(5th .January, 1840.
Length of head and body - . .
•' Tail ......
" Height of ear ....
of canine teeth
Weight, 149 lbs.
Fe«l,
1
3
1
.'}
•
11
4
11
2
8
.
3
1*
HABITS.
The Cougar is known all over the United States by the name of the
panther or painter, and is another example of that ignorance or want
of imagination, which was manifested by the " Colonists," who named
nearly every quadruped, bird, and fish, which they found on our continent,
after species belonging to the Old World, without regard to more than o'
most slight resemblance, and generally with a total disregard of propriety.
^ This character of the "Colonists," is, we are sorry to say, kept up to a
great extent by their descendants, to the present day, who' in designating
towns and villages throughout the land, have seized upon the names o'f
llomf, Carthage, Palmyra, Cairo, Athens, Sparta, Troy, Rabylon, .I.Micho,
and many other ancient cities, as well as those of Boston, Port ^rnoufh,
Plymouth, Bristol, Paris, Manchester, Berlin, Geneva, Portland, &c.. &c.',
from which probably some of the founders of our country towns may have
emigrated. We sincerely hope this system of nomenclature will hence-
forth be discarded ; and now let us go back to the Cougar, ..liich is but lit-
tle more like the true panther than an opossum is like the kangaroo!
Before, however, entirely quitting this subject, we may mention that for a
long time the Cougar was thought to be the lion ; the supp, .ition was
that all the skins of the animal that were brought into the sctilements
by the Indians were skins of females ; and the lioness, having sonethinp
nil
COUOAR.
807
the same colour and but ]\Uh mane, it occurred to the colonists that the
skins they saw couhl brlihir •.<» no other animal !
Tiie Cougar is found sparsely distributed over the whole of \orlh
America up to about latitude 45". In former times this animal was more
alumdant than at present, and one was even seen a few miles from the city
of New- York within tlie recollection of Dr. Dkkav who speaks of the
consternation occasioned by its appearance in Westchester County, when
he was a boy.
The Cougar is generally found in the very wildest parts of the country,
in d«ep wooded swamp;-i, or among the mountain cliffs and chasms of the
Alleghany range. In Florida ' -; inhabits the miry swamps and the watery
everglades; in Texas, he is so. etimes tbund on the open prairies, and
his tracks maybe seen at almof^ every cattle-crossing place on the slug-
gish bayous and creeks with their quick-sands and treacherous banks.
At such places the Cougar sometimes (inch' an unfortunate calf, or perhaps
a cow or bullock, that has become fast in the oozy, boggy earth, and
from exhaustion has given up its strugglings, and been drowned or sullbcat-
ed in the mire.
This species at times attacks young cattle, and the male from which
our drawing was made, was shot in the act < ( feeding upon a black heifer
which he had seized, killed, and dragged into the edge of a thicket close
adjoining the spot. The Cougar, is however, generally compelled to sub-
sist on small animals, young deer, skunks, raccoons, &c., or birds, and will
even eat carrion when hard pressed by hunger. His courage is not great,
and unless very hungry, or when wounded and at bay, he f^eldom attacks
man.
.1. W. Audubon was informed, when in Texas, that the Cougar would
remain in the vicinity of the carcase ot a dead horse or cow, retiring after
gorging himself, to a patch of tall grasses, or brambles, close by, so as to
keep off intruders, and from which lair he could return when his appetite
again called liim to his dainty food. In other cases he returns, after catch-
ing a pig or calf, or finding a dead animal large enough to satisfy his hun-
gry stomach, to his accustomed haunts, frequently to the very place where
he was whelped and suckled.
Dr. Dekay mentions, that he was told of a Cougar in Warren County,
ill the State of New-York, that resorted to a barn, from whence he was
repeatedly dislodged, and finally killed. "He shew, d no fight whatever.
His mouth was found to be filled with the spines of the Canada porcupine,
which was probably the cause of his diminished wai'iness and ferocity,
and would in all probability have finally caused his death."
The panther, or " painter," as the Cougar is called, is a nocturnal am-
S08
COUGAR.
nml mor. hy choice than necessity, as it can see wel. during the day time
ft steals upon .fs intended prey in the darkness of ni^ht with 'tsie^
caufous «tep and with great patience makes its noiseieis way 'h.:'
the angled th.ckets of the deepest forest. When the benighted travel er
or the weaned hunter „.ay be slumbering in his rudely and has.iiv con
strueted b.vouac at the foot of a huge tree, amid the lonely forest his fire
nearly out, and all around most dismal, dreary, and obscure, he ma^ p r!
chance be roused to a state of terror by the stealthy tread of the prowWn.
Cougar; or his frightened horse, by its snortings and struggles to getTo e
will awaken h.m in time to see the glistening eyes of the dangerou Zll
.larujg upon him like two burning coals. Lucky is he the' if ll coo
ne.s does not desert him, if his trusty rifle does not n.is.s, thro gh s" •
^.on or snap for want of better flint ; or well off is he. if he c.Tn fri; l^tn
avvav the savage beast by hurling at him a blazing brand from his nearly
ox .ngu,s ed camp-iire. For, be sure the animal has not approached im
v.hou. the gnawing hungcr-the desire for blood, engenclered by , "
" nc"' h'r^ T' T , '""''^•'^ '''''' '"^ ""' ^-" -t'-n,ica ed in!
tanc . have been recorded in our public prints, where the Cougar at such
Mmeshas sprang upon the sleeper. At other times the horses are thrrwn
mo .such a fr^ht, that they break al, fastenings and fly in every LeZn
1 he late Mr 1 ob^.t B.st of Cmcinnati, wrote to Dr. Go„m.., tha on of
e e ammals had surprised a party of travellers, sprung upo. the ho Is
■nd .so lacerated w,th its claws and teeth their flanks and buttock htt'
hey w.th the greatest difliculty .succeeded in driving the poor cr at r:
brio e them next mornu^g, to a public house some miles ofl: This pam'
nowe ver, had no fire, and were unarmed. ^ ^ '
A planter on the Yazoo river, some years ago, related the following anec-
lote 01 the Cougar to us. As he was riding home alone one night thro" .
he woods, along what is called a " bridle-path" (i. e. a horsr-trl ?„
r hese an.mals .sprang at him from a fallen log, hut owing to his h'^o
ak„,g a sudden plunge forward, only struck the rump o^ the .
steed w.,h one paw, and could not maintain his hold. The genH 1 „
was lor a moment unable to account for the furious start his h s h' d
.nade, but presently turning his head saw the Cougar behind and Zt
.purs u. his horse, galloped away. On examiJng U J 1^ ^ 2
were observed on his rump eorresponding with the Caws of 1 eV "
COUGAR.
309
to quret fhcm, thinking somn p.-rson. perhaps a neighbour, had called to
see him. Tho dogs could not be driven hack, but rushed into the house ;
he seized his horsewhip, whieh hung inside the hall door, and whipped
them all out, as he thouglit, except one, which ran under the table. He
then took a candle and looking down, to his surprise and alarm discover-
ed the supposed refractory dog (o be a Cougar. lie retreated instanier,
the females and children of his family fled frightened half out of their
senses. The Cougar sprang at him, he parried the blow with the candle-
stick, but the animal flew at him again, leaping forward perpendicularly,
striking at his face with the fore-feet, and at his body with the hind-!oet.
These attacks he repelled by dealing the Cougar straight-forwarJ Mows
on its belly with his fist, lightly turning a„.de and evading its claws, as he
best could. The Cougar had nearly overpowered him, when luckily he
backed toward the fire-place, and as the animal sprau- again at him, dodg-
ed him, and the panther almost lell into (he fire ; at which he was so terd-
fied that he endeavoured to escape, and darting out of the door was im-
mediately attacked again by tho dogs, and with their help and a club
was killed.
Two raftsmen on the Yazoo river, one night encamped on the bank,
under a small tent they carried with them, just large enough to cover
two. They had a merry supper, and having made a large fire, retired.
•' turned in " and were soon fast asleep. The night waned, and by degrees
a drizzling rain succeeded by a heavy shower pattering on the leaved and
on their canvas roof, which sheltered them from its fury, half awakened
one of them, when on a sudden (he savage growl of a Cougar was heard,
and in an instant the animal pounced upon the tent and overthrew it.
Our raftsmen did not feel the full force of the blow, as the slight poles of
the tent gave way, and the impetus of the spring carried the Panther over
them : they started up and scuflled out of the tent without furt.ier notice
"to quit," and by the dim light of their fire, which the rain had nearly ex-
tinguished, saw the animal facing them and ready for another leap ; they
hastily seized two of the burning sticks, and whirling (hem around (heir
heads with loud whoops, scared away the midnitrht prowler. After this
adventure they did not, however, try to sleep under (licir tent any more
that night !
We have given these relations of others to show that at long intervals,
an<l under peeuliiir circumstances, when perhaps pinched wifli hunger, or
in defence of its young, (he Cougar .sometimes altaeks men. These in-
stances, liowever, .are very rare, and the reladons of an afl'rightened
traveller must be received with some caution, making a due allowance
for u natural disposii !<>>>. ii; nsrui (o indulge in the marvellous.
MIO
COU(7AR.
•If
On. „ ,xporu.n.o ,„ rr«ar,I ,o ,1.. hnhits of tl.is spocioH is som.vvhat
1' >"«-Umh w.- aro o4,l„..,| „, s,at,. ,l.a, in ,I„. ,.m1v ll..v,. ins.a.Kvs i„
wind, w.- o»,s,.rv,-,I i, in i,s „a,iv.. IImvs.s. an inM-r^sion was iHi „„ ,.,„■
'■"".Is .l.a. ,r was ,1a. na.s, ....war.ll.y oC any sp,..-a.s ..f i,s si.. LHon-nn-^
N.<l.,s,MMu,s. 1„ our l.oylu,o.l. whils, .-..si.Iin. in ,1... no.,!...,,, pan ol
i\ow.\ork-. (orty-riglu yars ai^o. <„. our way ,o s.-Iuu,! Ihrowi,!. a woo.l a
^..nJ,^.^• n-oss,.,! ,1... ,,^,1, „„,, ,,.„ y,,,|s i„ iv,„„ „,■ „,. ^Vr l.a.l nrv',.,-
l..'lor.. s....n this sprci.s. and it was, ov.-n at tl.a, rarly p.rio,!. ,.xc,..,lin«lv
rare ,n ,hat vinni.y. Wl.n, tin- (%,n«ar oLs,.,.,.,! ns ho c-onnn.n.-nl a
»•">•••"•< .vhvat; a small lorri,.,- ,ha. a.vo.npaaio.I ns ...v.. ohas,. ,o (ho
■•Humal. wlnoh. aftn- running al.ont a hnn.hvd yards, nioun,..! an oak an.l
ivs...,l on on., of its lind.s ahont twonty foot iVun, thr «ronn,l. W. ap-
l.r..a..h,-d and rais...l a lon.I whoop, wh.n h. spran,^ .o ihooarlh an.l s.,on
">"<ie Ins os..apo. H,. was. a C.w .lays afl.Mwar.ls. hnn....l l.y ,]„. n..i,d.-
bours an.l sh.,.. Ano,h.-r was ,n...,l a. ni«l„, l.y ... p,,,,v on a ra,-...,on
»"'"f : s.ipposM.fr it ... 1... a mccoon. ..,„. ..f ih.. n..-n .■iin,l....l th.. Ir..,.
wi...n ,h,. Co„o:Mr I,.an..d ,.. ,h,. f^n.nn.I, ov.-rtnrnin^^ on,. ..f ih.. yoUn'-
l'""t.Ts that happ..n,-.l ,o b.. in his way. and n.a.l.- his ..s.-ap... A third
was ..has..,I l,y onr-dops in a vallry in ,ho vi.-inify of ,h,. Catskil! na.nn-
tan.s. and allcr half an hour's chase ns.-en.lrd a h,..-ch.tr,.,.. II,. pi.,..,.!
l.""s,-ll .n a crotoh, an.l was tin-d at will, .ha-k-shot al.ont a do/.,.n .in.,.s
whn, h,. was finally ki!l,.,l, a-..; fH! h..avily to th,- jjronn.l. A Mr. I{vv-
•"•>>•", ol A'u-inia. r,.|al,.,l to us an auu.sin;,^ an.-,..h„.. of a r.-n.-onlr,.
which he an.l a Kontuokian had in a vall,.y of,,,,,. „r ,h,. \i,f.,ni,, ,„„„„.
taw.s with •. C.ujrar. This occurr,.nc.. t....k place about thirty y.ars a^o
'1 l.,.y had no jinns. but .T'cctinfj l.i.n n.-ar ih,- n.a.l. (h.'v K.-n-.-'ciiasc with
II...M- h,)rs..s, and al>cr a run of a (i-w hnndr.'.! yanls h,. as,.,.nd,.,l a tree
KANnn,.rn clind„..l the tr,.,.. an.l the Cnw^^u- sprang d..wn. ay.,i,lin^r ,l,„
Kentuckian. wl... st.md r,.ady to attack him with his club. Th,- latter
asain f,.II.,w,.,l. on his h..rs,.. when he tr,.,.,! him a s.-cond lim,.. Han,,.., v„
Hfiain elimb.d aft,.r him. but fo,u.,l the animal was comin- down an.l
<iisp..s..d to liyht his way f<. the -round. He stmuuni him wi(h a blow
wh.n the Cougar 1,-t jjo his hol,l. (HI f,. ,h..,.arlh, an.l was kil by his
comrade, wh.> was wailin<r with his elub bel.,w.
Fn.m all th,- conversations we hav,. l,a,l with lnm(,.rs who w.mv in the
habit of killinsr ,hp rou;rar, w,. hav,. Ihmm. bn-n^ht to the r.,nvi,.ti..n that
a m;in of m..d..rat.. ,'oura^M.. with a «oo,l rilh^ an.l a s(,.adv arm. aeeom-
J.anied by (hiv.. or foiu' active d..}r,s, a n,i.xtur.. ..f ,.i,h,.r thV fox.|„.nn,l or
trri.y-hound. might hunt the Cougar with great safety to himseli; and with
a toh-rabl,. jirospeet of success.
This .animal, which has ..xcited ,s„ nujcli terror in the minds of the i-rno-
COUGAR.
811
mm. mul titni<l,l,as hern nearly oxtwrnhmUn} in all onr Atlantic States
and we ,Io „,„, ,...c.,lleot a single, well auM.,.,fieale,l instance where any
hunters hie Cell ji saeriliee in a CoM^ar hunt.
Ani.u.tr ,he inountains „r the head- waters of the .1 atta river, as we
were int..rnM.d, the (.'..u-ar is so ahundant, that one man has killed Cor
son.e y.-ars, rr.)n. tw<, t<. liv,., and one, very hani winl.T, he kilh-d seven
ill this j,art of the country the Co„Kar is hunlr.l with hall-bred hounds
the lull-l.looded doKs lacking courage to atta.dt s<, lar^.^ a,nd (iere,- look-
ing an anunal when they overtake it. The hunt is conducted n.uch in
;^''" "•';"•"''• •"■ ••' <d.ase after the eo.n-not. wild-cat. The Cougar is
treed alter running about lilt,.en or twenty minutes, a.,d getu'rally
shot, but sometimes it ..hews light before it takes to a tree, and the hunters
.•ons.der ,t great sport: we heard of an instance .,f one of these lights, in
whu-h the Cougar got hol.l of a dug. and was killing it. when the hunter
II. us aiu.ety to save his ,log, rttsh.-d upon the Cougar, seized him by tho
l.'iil and broke his back with a singl.-, b|„w ofa,, ,,x(^
According to the relations of old hunters, the Cougar has three or four
young at a litter. We have heard of a., instance of one being found a
very old len.ale. in whoso ,len there were live yo.n.g, about as large as cats,
we b.-heve. how,-ver, that the usual numlx-r of yonng. is two.
The dens of this species are generally near the tnouth of sotne cave in
the rocks, where the animal's lair is .j„st far enough inside to be out of
ll.n ram ; and not in this r.-npec-t like the dens of the bear, wbh-h are some-
tunes ten or twelve yards IV.,,,. the opening of a larg.- eraek or lissure in
tUi' rocks. In the Southern States, where th,-re are no caves or roeUs the
lair o( the Cougar is generally in u very dense thicket, or in a eane-brake
It .s a rude sort of be<l of sticks, wee.Is, leaves, ami grasscH or mosses,
and where the canes ar<,h over it ; ns they are .nergreen, their 1...,.^ p„i„t.
ed h-aves turn the rain at all seasons of the year. We have never ob-
serve,! any bones or fragments of ani.nals they ha.l li-d „p„„, ^t the lairs
ol the Cougar, and suppose they always feed on what they catch near tho
s|)ot where they captm-e the prey.
The tales r.dated of the cry of the Cougar in the forest in imitation of
the call of a lost traveller, or the cry of a chihl, nntst be receive.I with
much caution, and may in many of their exaggerations be set down as
vulgar errors. In a state of captivity, we have never heard the male ut-
t.-rmg a.,y other note than a low growl ; the female, however, we have
In-iu.-ntly heard utt.M-Jng a kind of mewing like that of a eat. but a mom
prolonged and louder note, that coul.l be heani at the distan.-e of about
two hundred yards. All the n.ah.s. however, of the cat kin.l. at the s.-a-
,.)n when the sexes seek each other, emit r,.markai,le an.l startling cries
312
COUGAR
as.•se^^dencodbythe com.non cat. i„ what Ls dono„.i„atod caterwaul-
» two .p, c, s of lynx. It ,s not i.npossil.l,., thorolor,., that .ho malr
C «gar, may at the ruttin, season have so.no peculiar a„. sta ,i ^^^^^^^^^^^^
To cr.es. however, to which persons have IVo.n time to tin.e .ii.^rrl ^
"^-..as,Hon,in,to the Cou.ar. we were well convinced wlu
ne ..y c^ er a.nna.s. In one ins.ance. we ascertained them to pr ^ ,
- a red ,„x winch was killed in the hunt, got up for ,he purpose ..f Idll-
.cd o, h„ ,. ,,,, ^,.^ ^.^^^^,^^,^ ^.^^ ^j^^ ^^.^^ ^^. ^^^.^ ^^^_ ^^^^
1 he female Couf^ar is a most alFectionate mother, and will not leave
her youn, cu s, unless occasionally to procure foo.l to supp<.rt h own
strength ; she t ere fore offen becomes very lean an<l poor. The Z2
we have hgured. was in this condition ; we procured one of her u l^
!r"irs ;!;ir""""' ''' '""'"" ''"''' '''''"" '^'"'•'^ "°^'^^^'- '^'^« ^
The whelps are suckle.l by the dam until about half grown, and then
hu.^ w.th the oh. ones (which generally go in pairs) un'l the „:!:'•
Vt'T' "^""' " ^"""^" °"^^ '^"'' '"'^^'^^ '■"•• "-'"-•-s, and begin
The period of gestation of the Cougar is ninety-seven days, as has l>een
ascerta.ned at the Zoological Society of London, (Proceedings, ^^l
i.han abundance of foo.l, and not much inconunoded by the cold, the
the young have in some instances been .liscov^.n-d in autu.nn. J W
AuuuBo. found, in Texas, young Cougars nearly half grown in February.'
OEOGRAPllICAL DISTRIUUTION.
This species has a wide geographical range, ft was formerly found in
all the Northern and Eastern States, and we have seen a speeLen pro-
;";;;;;' tt''T "V'''"'"' ''' '" ''" ""•' ''"• '^^ P™>-"^ residence
n a 1 the Atlant.c States ,t was formerly found, and a fi-w still exist in
<I.e less cultivated portions. It is occasionally shot in the extensive
swamps, along the river courses of Carolina, Georgia, Mississippi, and
^oms,,-ma ; ,t ,.s found sparingly on the whole range of the Alleghanies.
runnmg through a cnsi.lerable portion of the United States. It has cross-
.;d the Rocky Mountains, an.l exists on the Pacific, in Oregon and Cali-
(orn.a; ,t .s quite abundant in Florida and Texas, is found wiihin the
COUGAR.
313
tropics in Mexico, and Yucatan, and has penetrated through Panama in-
to Guyana and South America, where it is sometimes called the Puma
(JKNERAI. REMARKS.
The variations of size, to which this species is subject, have created
much confusion among our books of Natural History, and added a con-
nitltu-able number of supposed new species. AHer having examined very
carelully v<!ry many sp«!cimens, both in a prepared state, atid alive
in menageries, procured in most parts of North and South America, we
have arrived at the conclusion that the Cougar of North America and
the Puma of our Southern Continent are one and the same species, and
cannot even l)e regarded as varieties.
Vol.. u. — 4U.
314
GENUS BASSAUIS.—LiciiTENSTEiN.
Incisive -» Canine
DENTAI, FORMULA.
1-1 -. B-0
... n—u
Body, long nnd nithn- sloiulor; Ih-.u), round ; s„„„f, uUenuafo.l liko that
o( n lox; ,.y,... rallu-r In.K,. : ..ydi.ls. obl.mg, lalrral ; ears, CM.spicuous, of
I odcratp si/a; ihcir |)oinfs rounded.
Tliere are live toes on eacli liM)t ; tail, nearly ti.e length of the body.
Iliiirs on the body, siior muI densse, inueh longer on the tail.
The specific name is derived Iron, the Greek, B«»-«v.,,.. (husmris), a little
fox.
This is the only species in th«; f^'mus.
1
BASSAKIS ASTUTA.— Licirr.
RiNfJ-TAU.KU HaSSARI.S.
PLA'^S XCVIII.— Male.
R. Supra p;ilvus nigro-varleKatus, aurieulis, macula supra oculari et
ventre flavido-albis ; cauda, annulis octo all.is nigrisque alternantibus.
picta.
CHARACTERS.
Dill/ ycUow, mixed with hlach, above ; a sjwt above the eye, ears, ami
unikv surface, yellowish-white ; tail, eight times ringed with black and
white.
HYNONYME8.
CArAMiTzri.i, ncniniidcz.
Tki'k-N!axti.aton, I Icinandpz,
Bassakis AsriiTA, l.i.liiinst.iii, Daistellnng neuer, oder wenig bckiuinler Siiu-
pi'tiiiiMv, TuCel 4a, Berlin, l>27-ly34.
DESCRIPTION.
The first impression made by this inimal on the observer is, :! rt Jie
has met with a little fox ; its erect cars, sharp nose, and cuimmg loolf, are
f'l
h
; 1
i ■:
■( ■■
'■ '
Ifl
.>Lmi\
BASSARIS ASTUTA.
315
all fox-like. It however, by its long and moveable muzzle approaches
the civets, (uiverra,) the genets, (genneUa,) and 'he coatis (/> '■(/rv.)
The head is small ; skull, not much flatteni i ; nose, long ; muzzle, point-
ed, naked; moustaches, numerous, long and ri;;id ; cars, long, erect, ova!e,
clothed with shorf hair on the outer surface; spari.igly within; neck and
body, long ; legs, longer than those of the martens, but shorter llian tho>?
of the fox ; niiils, sharp and much hooked; to i, gov. red with ha'rs con-
cealing them ; pilms, nnked ; tail, with long con>se h,, s, containing
scarcely any under fur ; the inner hair on the back, is of moderate fine-
ness, int'Tspei^ed with rather coar jer and longer hairs. The longer hairs
on the back are about an inch in length, those on the tail, two inches, and
the under-fur, on the back, half an inch.
coloi;r.
Thr hair on the back grayi.ii, for three-fourths of its K ngth from the
roots, thiMi pale yellowish-white, then i-Uowish-l vn, deepening into
black ai the tips ; the under-fur is first plumbeous, , n<-n yellowish-white :
this disposition of o(7lours gives it a brindled brownish-black appearance
on the head and upper surface. Moustaches, black ; point of nose, dark
brown. Thitre is a light grayish spot above the eye ; ears, chin, throat,
neck and I'lly, yellowish-white The tail is regularly and conspicuously
ringed with bars of vhito and bhu k, alternately ; the upper white one
very indistinct , the n. xt blaek-obscure and increasing in more conspicu-
ous bands of white an! black to the end, which is broadly tipped with
black : on the upper surface of tail, the black colours pedominate, and on
the under surface, the white.
DIMENSIONS.
From pt lit r^ no'^e to root of tail.
Tail, (vertebraj), . . -
" to end of hair,
From point of nose to head, between the
Height of ear, posteriorly,
From shoulder to end of toes,
Length of longest mt istache,
irs,
FM.
loehea.
1
G
1
2
1
4
• H
-
■ If
-
1
•
6
•
■ 8i
H
yio
liASSARIS ASTUTA.
iiABrr^.
The smafer porrion of Texas is prairio-Iand. and it is chiofly along the
water course., that trees are found ,rovvi„, to,.rher in nun.be's su( ei n
to constitute a "wood." On certain level and el,,yey portions tt
. pran.e, however, the land is swan.py. and .s covered with several ki
of oaks and a few other trees. The well-known „,us,uit tree o u ,
found generally distributed in the western parts of the State It r
«en.bes the acacia in leaf, and has a small .vhite pea-shaped blossom:
a a distance ,t looks something like an old peach tree. Its wood is .imi-
I.trto coarse mahogany in app.-arance, and burns well, in fact beaut i-
r oi: rth'''^'^ ''"'::" '--' "^"''-' ^^-e wood'givesl'Til
o no smoke The musqu.t bolton.s are furnished with these trees they
are small, about the size of the alder, and grow much in the same Z7-
e musqu.t as sharp thorns. The musquit ,r.ss, iHolcus lanntns), H
sembles what .s called, guinea grass, it is broader, shorter, softer.'and
The general features of ihe State of Texas, as it will be seen bv the
forej^o.ng do not indicate a country where many tree-climbing animals
could be found, and the present beautiful species, which ProfeLor L !
jxp.,. rnost appropriatelynamedBassnris ..,„,., is by nomeans common.
It .s a hveiy. playful, and nimble creature, leaps about on the tree. Z
has very much the same actions as the squirrel, which it resembles in a'^i'litv
and gPHce, always havin.: a hole in the tree -ipon which it resides^.,nd
betaking itself to that secure retreat at once if alarmed.
The Bassaris Astuta is shy and retired in its habits, and in the daytime
often stays in its hole in some tree, so that we were only able to procure
about half a-dozen of these animals during our stay in Texas; among
which, to our regret, there was not a single female.
The food of this sp. ies is chiefly small animals, birds, and insects ;
they also eat nuts, as Me w.re told, descending from their hidin" place
and travelling to the pecan and other trees, for the purpose of Ivedhvr on
the nuts which, if true, is singular, as they are decidedly carnivorous in
their dentition.
They are much attached to the tree on which they live, which is gene-
rally a post-oak, a live-oak, or other large tree, and they seldom quit the
immediate vicinity of their hole, unless when driven out by thrustin^^ a
stick at them, when they ascend the trunk of the tree, and jump about
among the higher branches so long as the pole is held close to their nest •
as soon ns this is withdrawn, they descend and at once re-enter their .lw,.i!-
ing-nlace an.) hi le themselves. These animals have a singular h.ibit nt
I'^/y
BASSARIS ASTUTA.
817
patinp or pnawing off tSr hark nround the mouth of thrr holes, and
-.vhero the bark does no' -ip,,, ,-,,• Ih-^hly peeled olFut Iheir hole, y')i,' may
be cerlaia the animal is ..o' at home, or has deserted the place.
Their holes are gener. I - the t^ ilt of natunU deeay, am. are situated mi
knobs, or at the ends o-' bran' ..^ broken short off clos.. to the main trunk.
They RiMierally select r h, . of this kind on the lower side of a leaning
tree, probably for better {.ici.uion from the rain ; th<-irhu!es vsry mi deptl,,
but are seldom more than almut a foot or eighteen inches to the bottom;'
they are usually furnished with moss or grass, for bedding. .Sometimes
pecan shells are found in these holes, which no doubt alfords presumptive
evidence that the Bassaris (eeds upon this nut.
When scolding or barking at a , intruder, the ring-tailed Raccoon (as
this animal is called by the Texan.,, holds the tail over its bnc!-. bendin-
it squirrel fashion ; this animal, however, does not stand upon his hind
feer like a s.piirrel, and cannot jump or leap so tar. We have not heard
ol their springing from one branch to another beyond the distance of about
ten feet, and when frightened at the presence of a man, 'hey v.ill some-
times run along a branch even toward him, in order to get within jumping
distance of another, evincing more timidity than a squirrel exhibits in
springing among the boughs, although they run up the bark with ease
holding on with their claws, '
Sometimes the Ring-tailed Bassaris may be seen squatted on the top of a
branch, basking in the sun, and half rolled up, appearing almost asleep.
On the slightest manifestation of danger, however, he darts into his hole
(which IS always within a foot or tw., of his basking plac(-), and he is seen
no more. W" have the impression that only one of these singular ani-
mals IS to be found on a tree at a timc-they, therefore, are not verv social
in their habits, and, as the live-oak and other trees are generally very
much scattered, and many of ihem have no holes suitable foi residences
lor the Bassaris, it is very diincult to procure one. At the foot of manr
of the trees whereon they dwell, the cactus, brush-wood, and chapperal
generally are so thick and tangled, that a man would be pretty well
scratched should he attempt to penetrate the thorny, prickly thicket which
surrounds the dwelling-place of this solitary and singnba- animal.
NotwithstiUKling the shyness and retireci habits o.' this species, it is
easily tame<i, and when it has lieen confined in a cage a sutficient leix'th
oftime, is frequently lei loose in the houses of the Mexicans, where" it
answers the purpose of a pi lyful pet, and catches mice and rats. We
have seen one that was thus domesticated, running about the streets of a
little Mexican village, and w>. were informed that one was kept as a great
pet in a Camanche camp, visited by the Indian who hunted for uh duiin^r
Mi
318
''•i
I '•!'
i M
BASSARIS ASTUTA.
our explorat ons o the western part of Texas. As far as we could ascer-
tan the northern Lrrut of the range of this species is somewhere in the
ne^hbourhood of the southern frv », -s of Red river. As you travel
south thej are more abundant, a biy are found throughout all
Mexico ; we were informed by o. .J, the celebrated Col. IIavs ,he
ianger that he saw them more r'. ..uant in the mountainous region ^ear
the head-waters of the San Saba river than at any other place
The Bassans produces three or four young at a birth, as has been as-
certauied from the animal kept in confinement.
GEOGRAPHICAL DISTRIBUTION.
This animal exists in Mexico, and is common in the immediate vicinity
of the capital of that name ; our specimens were obtained in Texas, which
appears to be its northern limit.
^! i^
t t
GENERAL REMARKS.
This species is called by the Mexicans caco-mixtle. It is mentioned
no less than four times by Hernanpe. under the n.-.mes of Cacamiztii and
Tepe-Maxtlaton. The first specimens were sent to Berlin in 1820 by Mr
Deppe. and the earliest scientific description was given by L.chtenstein'.
wjio named it as above.
819
SPERMOPHILUS LU DO V ICI A NUS.-Qrd.
Prairie Marmot-Squirrel— Wishtonwish.— Prairie Dog.
PLATE XCIX.-1. M^LE. 2. P^malk. 8. Yovm.
S. super cervinuspilisnigris interspersis ; subtus sordide albus, ungue
pollican conico majusculu, caudSbrevi apicem versus fusco torquatfi.
CHARACTERS.
Back, reddish brown, mixed with grey and black ; belly, soiled white ; tail
^hort, banded wUh brown near the tip ; thumb-nail, rather large, and conical.
8VN0NYMES
Prairie Dog, Lewis and Qark's Exp., 1st vol., p. 67.
WisHTONWisii, Pike's Expedition, &;o., p. 15G.
Arotomvs Ludovicianus, Ord, in Guthrio, Geog., 2d, 302, 1815
AucTOMvs MissouBiENsis, Warden, Descr dos Etats Unis, vol. 5 , p 507
Abctomvs LuDoviciANus, Say, Long's Exped., 1st vol., p. 451.
Arot. LuDoviciANUs, Hailan, p. 100.
" " Godman, vol. 2, p. 114.
DESCRIPTION.
This animal in its external form has more tne appearance of a mar-
mot, than of a spermophile. It is short, thick, and clumsy, and is not
possessed «f the light, squirrel-like shape, which characterizes the spermo-
phth. In its small cheek-pouches, however, being three-fourths of an
inch in depth, and in the structure of its teeth, it approaches nearer he
sprrmophil,, and we have accordingly arranged it under that genus.
The head is broad and depressed; nose short and blunt, hairy to the
nostrils. Incisors, large, protruding beyond the lips ; eyes, large ; ears
placed far backwards, short, and oblong, being a mere flap nearly
covered by the short fur ; neck, short and thick ; legs, short and stout.
1 his species is pendactylous ; the rudimental thumb on the fore-feet pro-
tecfed by a sharp, conical nail ; nails, of medium size, scarcely channelled
beneath, nearly straight, and sharp, extending beyond the h^ir ; tail, shorl
320
PRAIRIE DOG.
and bushy ; hair on the body, rather coarse ; under-fur, of moderate fine-
ness. The female has ten mamma? arranged along the sides of the belly.
COLOUR.
Tho hair on the back is, from the roots, for one-third of its length, bluisli-
black, then soiled-white— then light-brown ; some of the hairs having
yellowish-white, and others black, tips. The hairs on the under-surlace'!
are at the roots bluish, and lor nearly their whole length yellowish-white,
giving the sides of face, cheeks, chin, and throat, legs, belly, and uiider-
surtace of tail a yellowish-white colour. Teeth, white ; moustaches and
eyes, black ; nails, brown. The tail partakes of the colour of the back for
three-fourths of its length, but is tipped with black, extending one inch
Irom the end.
DIMENSIONS.
MALE.
f'EMALE.
•
13 inches
12| inches
• ■
161 do
IT)! do
-
21 d,,
2i do
-
34 do
.
1* do
14 do
• «
tV do
r\ do
-
la do
W^ do
•
Vjdo
li do
.
24 do
2 do
•
1 do
e.
1 do
HABITS.
Nose to root of tail,
" to end of tail.
Tail, vertebrae,
" to end of hair,
Nose to anterior canthus,
Height of ear,
Width between eyes.
Length of fore-hand,
" of heel and hind-foot
Depth of pouch,
Diameter of ditto.
Feet slightly webbed at base.
The general impression of those persons who have never seen the
'Prairie Dog" called by the French Canadians " petit chien," would be
far from correct in respect to this little animal, should they incline to con-
sider it as a small " dog." It was probably only owing to the sort of yelp,
chip, chip, chip, uttered by these marmots, that they were called Prairie
Uogs, for they do not resemble the genus Cams much more than does a
common gray squirrel !
This noisy spermophile, or marmot, is found in numbers, sometimes
hundreds of families together, living in burrows on the prairies ; and their
galleries are so extensive as to render riding among them quite unsafe in
oderate fine-
of the belly.
sngth, bluisli-
laiis having
ider-surl'acc,
)wish-white,
, and under-
istaches and
the back for
ing one inch
f'EMALE.
2i inches
51
do
2i
do
li
do
7
do
'iV
do
14
do
2
do
?r seen the
" wouhl be
line to con-
sort of'ycip,
lied Prairie
;han does a
sometimes
; and their
e unsafe in
PRAIRIE DOG.
321
many places. Their habitations are generally called •' dog-towns," or
villages, by the Indians and trappers, and are described as being inter-
sected by streets (pathways) for their accommodation, and a deVee ol
neatness and cleanliness is preserved. These villages, or communities,
are. however, sometimes infested with rattle-snakes and other reptiles,
which feed upon the marmots. The burrowing owl, {Surnia citnicularia,)
IS also found among them, and probably devours a great number of the
defenceless animals.
The first of these villages observed by our party, when we were as-
cending the Missouri river in 1843, was near the "Great bend " of that
stream. The mounds were verv low, the holes mostly open, and but few
of the animals to be seen.
Our friend Edward Harris, Mr. Bell and Michaux, shot at them, but
we could not procure any, and were obliged to proceed, being somewhat
anxious to pitch our camp for the night, before dark. Near Fort George,
(a little farther up the river,) we again found a village of these marmots,'
and saw great numbers of them. They do not Ixn-k, but utter a chip
ch.p, chip, loud and shrill enough, and ai each cry jerk their tail, not
erecting it, however, to a perpendicular.
Their holes are not straight down, but incline downwards, at an angle
#f about forty degrees for a little distance and then diverge sideways or
upwards. We shot at two of these marmots which were not standing
across their lioles apparently, but in front of them, the first one we
never saw after the shot; the second we found dying at the entrance oi
the burrow, but at our approach it worked itself backward-we drew
our ramr<^ ,,r^ put the screw in its mouth, it bit sharply at this but not-
wMhstanding cur screwing, it kept working backward, and was soon out
oi sight and beyond the reach of our ramrod.
Mr. Bki.l saw two enter the «ame hole, and Mr. Harris observed three
Occasionally these marmots stood quite erect, and watched our move-
ments, and then leaped into the air, all the time keeping an eve on us.
We found that by lying down within twenty w thirty steps of their holes
and remaining silent, the animals re-appeared in fiftert, or twenty minutes'
Now and then one of them, after coming out of its hob-, issued a lonjj
and somewhat whistling note, perhaps a call, or invitation to his neigh-
bours, as several came out in a few moments. T^^ cri^s of this species
are probably uttered for their amusem^-nt, or nt, h m*^s of recognition
and not, especially, at the appearance ol -^anger. Thev are, as we think'
more in the habit of feeding b> night than m tb. day time ; their drop-
pings are scattered plentifully in the neighbourhoo<t of their villages
A few days after this visit to the Prairie Dogs, one of our hunters, who
VOL. II.
-11
•'^-2
PRAIRIK DOU.
nml hen. ou, . ,,-,..t part of th. „i,ht. brou.l.r i,. ,hrne oCrhom but th.v
.^JV..m.ho,,„,„ber„r,,„„i, i„ ,Ke l™„l., ,he ,p„„ie, i, no ,l„„l,. v,^
»,, „„r r,.,„r„ ,l„w„ U>o ,i.„r. w,. Idlln.l ,„•„ I'lairi,, Do , ,|„. -U,
° : " '"""""" » ""' >■""■'"-'■: I"" » 0„, „l, „,„.„, ,, lively Jir
pert us on .iiiy .siiiiiiiu'r day." ^
Tliis is not in accordance wi.J, the accounts of authors who have if ,h..f
«'<l ahm- the jrround uninjured." We feel .r.v.ilv i.r i. '"'"■''■«"-
''-"■" '- "•• ^'>- -. >w.^oh, :;,;:;:, i;,,:':;:',.^:::;,,;^;;::;;
or ac(iu,iiMfs us wiili a I'let ni'v,..,, • . '""^ "« ' M\e(l <>iror,
H.an.es of e.iu.a.e .i, ;,;::,:: :'::•;:;;;: ':':"t' "'"•^-"""
sion ofnanuv. heM<..-e<i upon son.; iu. tl ' ^tT'"''' ' l"''-^"
II- rigorous winters of the north • ., th. t v'. ■ '""'' •'"'■"'^'
vneei,.s .l,..t », ii • .• ,''""'''> ""-'•'"i'"'^' '" ^^ Warmer re-ion
^ p. « ...s th. t wonhl, n, h,,^h latitudes he cou.pelled to sleep out half Th,. r
hves eoul e„oy the air and ,i,ht. and luxuriate in the ' use f ' , ,
l.v. all the envlin. ye.r ! We have not heen able to «at e -. v in
;=:::*;;;::;;::t::::r :••--
; • ^"■""■■''- "• '' -,...i ....... :, -ir , :: r: :
temporary ani.nation ; thus shewi,,.. thit •. ...t ■ .
:rT""'' '>•• --■ X::r ™ :r ;;i:;t:;
l..wi« ,„„| Ch.ri< give a v,.ry ,.„„, .,,.„,,p,,,„ „r „,e p„i„, „„^, ,„
i'lUIUIH DOG,
page ai, vol. 1. They pomrd five barrels of
without fill
after di>i;,'in<r d
iri}? it, but. di8l()(l;,rc(l !iii(i cjiu.'ht tl
wafer into one of their hoi
es
10 owner. Tiiey further say thai
«ing down anuther of M„. huh's for six feet, they found
pole into it thattlu.y had not yet dug half-way to ll
bottoi
on ruiMiinj;
n ; tlicvdi>
which had swallowed one; of the Prairi.' Do-,'s.
Our friend Dr., now Sir .Io„n R.cnAunsoN^dn the Fauna Boreali Ameri-
cana,) has well eluei.lated the notices of -his and othe^ species <lescribed in
Lkw,s and C..HK's '• Expedition," but, appears not fo be certain whether this
ar.'mal has check-pouches or not, an<I is puzzled apparently by the li.l lowing,:
He ,,aw . furn,shed wi.h . j.onck fo contain his food, but not so large L
l... of the common squirrel." The JJr. in a note says-" It is not easy
N. d.v.ne what the " common scp.irrel is which has ample cheek-pouches."
We presun.e that this passage can be ,nnde plain by inserting the word
{rro,n,d so that " eounnon A"o//m/-s,p.irrel" be the readin- The " com
mon ground s,ui..rel" was doubtless well known to l.nvis^nd C,m„k. and
Ins an.ple eheek-pouches (see our account of T,n,uos L,s,rrn, vol. 1, p. ,;5 )
l.is explanat.on would no, be volunteered by us but for our respect for
he knowle.lge and accuracy of L.vv.s and C.hk, both of whom we had
tfi(! pleasure of personally knowing many years ago.
FV.r an amusing account of a large villag,: of ,l,ese marmots, we extract
the following from Kknoam/s Narrative of the Texan Santa Fe Rxp,.,lifion
vol. 1, p. 18». '' VVe bad proceed,.,! but a short ,]istance, after reaching
<h,s beautiful prairi,., helbre we came upon the outskirts of the common-
wealth, a h>w scattering dogs were so,.n scampering in, their short, sh.rp
.yelps g.vmg a general alarm to the whole community. The first brief cry
..t dang,.r from the ..u.skir.s was soon taken up in the centre of the
e.ry andnow nothing was to be heard or seen in any direction but a
bark.ng dashing, an.l s<.amp,.ring of the m.Tcurial and excitable denizens
ol lli(> place, each to his burrow.
Far as the eye coul.l reach the city extended, and all over it the scene
was the same. We r,,,!,- h-isurely along until we had reached the mor,^
flu,.kly setfh.,1 portion of the place. H.-re we halte.I. an,' alter takin^.
the bndles from our horses to allow iU,u to graze, we prepared for I
regular attack up, ,, th- i .hal.itants. Th,- bnrrows were not more than
ten or fifteen yanis ap rt. with well trodden paths leading in different
duTct.ons, and I even fa.,ci,.,I 1 could discover something like reg.daritv
in the laying out of the stre,.|s. "
We sat ,lown upon a ba.dc .mdcr the sha,le of a nu.s.put, and leisurely
survey,.,l the scene before us. Our approach had driven every one t„ his
home u. our imm,.diate vicinity, but at the distance of some hundred yanls
3-'4
PRAIRIE DOG.
the small mound of earth in front of each burrow was occupied by a Doj;
sitting erect on his hinder legs, and coolly looking about for tie cause ol
the recent commotion. Every now and then some. citiz<-n, more adven-
turous than his neighbour, would leave his lodgings on a flying visit to a
friend, apparently exchange a few words, and then scamper back as fast
as his legs would carry him.
By-and-by, as we kept perfectly sHll, some of our near neighbours were
seen cautiously poking their heads Irom out their holes, and looking crafti-
ly, and, at the same time, inquisitively about them. Gradually a citizen
would emerge from the entrance of his domicil, come out upon his obser-
vatory, perk his head cunningly, and then commence yelping somewhat
after the manner of a young puppy— a ciuick jerk of the tail accompany-
ing each yelp. It is this; short bark alone that has given them the name of
Dogs, as they bear no more resemblance to that animal, either in appear-
ance, action, or manner of living, than they do to the hyena.
We were armed, one w ith a dou!)le-barrelled shot-gun, and another
with one of Colt's repeating-rifles o( small bore, while I had my short heavy
rille, throwing a large ball, and acknowledged l)y ;tll to be the best wea-
pon in the command. It would drive a ball comjdetely through a buffalo
at the distance of a hundred and fifty-yards, and there was no jumping off
or running away by a deer when struck in the right place ; to use a com-
mon expression, "he would never know what had hurt him." Hit one of
the Dogs where we would, with a small ball, he would almost invariablv
turn a peculiar somerset, and get into his hole, but by a ball, from my rifle,
the entin^ head of the animal would be knocked off, and after this, there was
no escape. With the shot-gun again, we could do nothing I.nit waste ammuni-
tion. I fired it at one Dog not ten ste|>s off, having in a good charge of buck-
shot, and thought I must cut him into fragments. I wounded him severely,
but with perhaps three or four shot through him, he was still able to
wriirgle and tumble into his hole.
For three hours we remained in this commonwealth, watching the
movements of the inhabitants and occasionally picking off one of the more
unwary. No less than nine were got by the party ; and one circumstance
I would mention as singular in the extreme, and shewing the social rela-
tionship which exists among these animals, as well as the kind regard
they have for one another. One of them had perched himself upon the
pile of earth in front of his hole, sitting up and exposing a fair mark, whik
a compa.iion's head was seen poking out of the entrance, too timid, perhaps,
to trust himself farther. A well-directed ball Iroui my rifle carried away
the entire top ol' the (brmer's head, and knocked him some two or three
PRAIRIE 1)00.
325
out, seized his companion hy one of Jiis ie<,'s, and before we could reach
the liole had drawn him completely out of sight. There was a touch of
feeling in the little incident, a something human, which raised the animals
in my estimation, and ever alter I did not attempt to kill one of them,
except when driven by extreme liungor.''
Mr. Kenpai-l says, further on, of llu'.-^e animals: — "They area wild,
frolicsome, madcap set of fellows when undisturbed, uneasy and ever on the
move, and appear to take especial delight in chattering away the time,
and visiting from hole to hole to gossip and talk over each other's affairs
at least, so their actions would indicate. When they find a good location
for a village, and there is no water in the immediate vicinity, old hunters
say, they dig a well to supply the wants of the community. On several
occasions I crept close to their villages, without being observed, to watch
their movements. Directly in the centre of one of them I particularly
noticed a very large Dog, sitting in front of the door or entrance to his
burrow, and by his own actions and those of his neighbours, it really
seemed as though he was the president, mayor, or chief— at all events, he
was the " big dog" of the place. For at least an hour I secretly watched
the operations in this comnmnity. During that time the large Dog I have
mentioned received at least a dozen visits from his fellow-dogs, which
would stop and chat with him a few moments, and then run off to
their doir.4cils. All this while he never left his post for a moment, and I
thought I could discover a gravity in his deportment not discernible in
those by which he was surrounded. Far is it from me to say, that the
local government of the village ; but it certainly appeared so. If any
animal has a system of laws regulating t'ae body politic, it is certainly
th(! Prairie Dog."
This marmot tumbles, or rolls over, when he enters his hole, " with an
eccentric bound and half-somerset, his hind-feet knocking together as he
pitches headlong into the darkness below ; and before the spectator has
recovered from the half-laugh caused by the drollery of the movement, he
will see the Dog slowly thrust his head from his burrow, and with a pert
and impudent expression of countenance, peer cunningly about, as if to
ascertain the effect his recent antic had caused."
Mr. KuNDALL thinks that the burrowing owl, which he mentions as " a
singular species of owl, invariably found residing in and about the dog
towns," is on the best of terms with these marmots, and says, "as he is
frequently seen entering and emerging from the same hole, this singular
bird may be looked upon as a member of the same family, or at least, as a
retainer whose services are in some way necessary to the comlbrt and
l\
326
PRAIRIE DOG,
J m
vvell-boing of the animal whoso hospitaliiy he shares." This idea is
doubtless incorrect, and we vv„„l,l uitnost hazard the assertion that thf se
owls prey upon the yonnfr, or evn. the adults, of these marmots; theJ
also, proi,ahly, devour tiie bodies of those which die in tlieir holes and
thus may stand toward the animals in the light of sexton an.l undertaker >
Mr. Kendall is entirely correct in what he says about the rattle-snaice.
^vlnch dwell in the same lodges with the Dogs. « The snakes I look upon
as loafers, not easily shaken off by the regular inhabitants, and they make
use of the dwellings of the Dogs as more comfortable quarters than they
can find elsewhere. We killed one a short distance frotn a burrow which
had made a meal of a half:.grown Dog ; and although I do not think they
can master the larger animals, the latter are still compelled to let thetn
pass in and out without molestation-a nuisance, like many in more ele-
vated society, that cannot be got rid of."
Mr. KiCNPA,,!, and his companions found the moat of this species "ex-
eeedmgly sweet, tender, and juicy-resembling that of the squirrel only
that it was much fatter." ' ''
None of these animals were seen by J. W. Audubon in his journey
through that part of Texas lying between Galyeston and San Antonio and
he only heard of one village, to the northward and westward of Tor'rey's
Lodge; they do not approach the coast apparently, being found only on
the prairies beyond, or to the westward of the wooded portions of that
htate. A collector of animals and birds, who has passed the last three
years m various parts of Mexico, and who showed us his whole col-
lectioTi, had none of these marmots, and Nve suppose their range does not
extend as far south as the middle portions of that country.
GEOGRAPHICAL DISTRIBUTION.
This species is found on the banks of the Missouri and its tributaries
It also exists near the Platte river in great abundance, [t was seen by
J. W. Audubon in limited numbers in Sonora and on the sandy hills -J
.lom.ng the Tulare Valley, and in other parts of California. We do not
know whether it is an inhabitant of Oregon or nr t.
327
MUS MISSOURIEx^^SIS.-Auo.A^nBAcu.
Missouri Mouse.
PLATE C._Female8.
albidis, cauda curta.
M. capife aniplo, cruribus robustis. auriculis sub
corpore supra dilute lusca, infra alba.
iif/ovc, white beneath.
CHARACTERS.
ears, ichhish ; tail, short, light fawn colour
SYNONYME.
AIusM.ssouaiE.sis, Aud. and Bach., Quads. North America, vol. 2. plate.
DESCRIPTION.
At first sight we might be tempted to regard this animal, as one of the
endless varieties of the white-footed mouse. It is. however a verv if
11, |"'iiirta , e3es, huge ; ears, short broad -it
.aches, numerous. Ions, heading Ibrwanb an,l u,nv„r,l, ■ lei I,;, T
.00, on ,he fore reet, „„h .he rndi.en. ola =h„,n'h, t'c. Jh; t e nt "
euous na,l , na,l,, rather bn^, slightly hen,, bu, no. h„„l,e,l. The hi ,1,10
are pcnclacylons , the pahns are naked ; ,he „,her portions o, the , nd
oes,eoveredw,,h short hairs, which do no,, however, conceal the ,1
rhe ,a,l „ short, round, stout a. base, grudnally d.minishing to a po^, !
:z:z'i^z' "'* '"' *"' '^"■■' "■' '- °" ""^ -*- ;•
COLOUR.
Teeth, yellowish ; whi.sker.s. nearly all white a few hl.,.l. u • •
snersed The fur ,.„ tK i , • , ^ " ^ ""«• a lew black hairs inter-
persed. The fur on the back ,s plumbeous at the roots to near the points,
32S
MISSOURI MOUSE.
the hairs on the sides are broadly tipped with yellowish-fawn, and
on the back, are first fawn, and then slightly tipped with black ; on
the under surface, the hairs are at the roots plumbeous, broadly tipped
with white. The ears are nearly white, having a slight tinge of buff on
the outer and inner surlaces, edged with pure white; on the r-ides of the
checks, and an irregular and indistinct line along the aides, the colours
are brighter than those on the flanks, and may be described as light yel-
lowish-brown. The feet, on both surfaces, belly, and under surface of tail,
white ; from this admixture, this species is on the back, light fawn, with
an indistinct line on the back, and upper surface of tail, of a shade' dark-
er colour.
DTMEMSIONS.
From point of nose to root of fail,
tail.
Height of ear, posteriorly,
tncbes.
4i
HABITS.
We close our second volume with this new species of mouse, of which
we have given three figures. This pretty little animal was discovered for
us by Mr Demg, during our sojourn at, and in the neigiibourhood of Fort
Union in 1813. It was in full summer pelage, having been killed on the
14th of July. At that time being in quest of antelopes and large annuals,
we did not give it that close attention, which we should have done. A
glance at our plate, or an examination of our description, will suffice to
convince any one of its being entirely new. This species is much larger,
and has a thicker and shorter tail than ?nus Icucopus.
Expecting to get more of them we did not make any notes of the
habits of those killed at that time, and which had doubtless been observed
by the hunters, who procured them. The next day after they were
brought in, we left the fort on an expedition to the Yellow-Stone river,
from which we did not return for some time.
As a short description of our mode of travelling, &c., the first day's
journal is here given. "July 1.5. Saturday, we were all up pretty early,
making preparations for our trip to the Yellow-Stone river. After break-
fast all the party who were going, announced themselves as ready, and
with a wagon, a cart, and two extra men from the fort, we crossed the
Missouri, and at 7 o'clock, were fairly under way; Harris, Beli,, Cul-
BERTsoN, and ourself in the wagon, Suuires, Provcst, and Owen on horse-
back, while the cart brought a skifi", to be launched on the Yeliow-Stone,
MISSOURI MOUSE.
'529
U
3
itU w
should arn. cut I „ river. We travelled rather stowly ui, 1
e hftd crossed a point and licude.l tho ponds on the prairie at the loot
o^ the ialls opposite the f. W . one sharp-tailed grouse, but al-
though Mr. Harris scare d.hgently, it could not be started.
>oon after this we t^,,t one of th.- wheels of our wagon fast in a crack
or crevu-e m (ho <rrou.ul, and wrenched it so badly that we were oblLr,-,!
to get om an. .Ik. while the men set to work to repair the wl.,".N
which were ail m a rickety condition ; after the needful (Ixing-up had
been done, the wagon overtook us, and we proceeded on. Saw some
iintelopcs on the prairie, and many more on the tops of the hills bound-
.ngour view to the westward. We stopped to water the horses at «
•saline," where we observed ' at buflaloes, antelopes, and other animal.
had been to drink, and had b, lying down on the margin. The water
was too hot for us to drink. Alter sitting for near!' an hour to allow the
horses to get cool enough to take a bait, for if was very warm, we a-ain
proceeded on until we came to the bed of a .ueam, which during spWng
overflows its banks, but now exhibits only pools of water here and there
In one ol these pools we soaked our dry wagon wheels, by way of ti-ht-
emngthe "tires," and here we refreshed ourselves and quenched "our
thirst. SauiREs, Provost, and Owen, started on before us to reconnoitre,
and we followed at a pretty good pace, as the prairie was hereabouts firm
and tolerably smooth. Shot a red-winged black-bird. Heard the notes
of NaiTALL's short-hilled marsh-wren.-supposed by some of our party
to be those of a new bird. Saw nothing else ; reached our camping-place
at about G o'clock. Unloaded the wagon and cart, hobbled the horses
and turned them out to grass. Two or three of the men went off to a
point above our camp, in search of something for supper. We took the
red-winged black-bird, and a fishing-line, and went to the bank of the famed
\ ellow-Stone river, (near the margin of which our tent was pitched,) and
m this stream of the far west, running from the bases of the Rocky Moun-
tains, we threw our line, and exercised our piscatory skill so successfully
as to catch some cat fish. These fish we found would not bite at p-ces
of their own kind, with which we tried them ; after expending our bird
bait, we therefore gave up fishing. One of our men took a bath, while
two others, having launched the skifl" rowed across the river to seek for
deer or other game on the opposite shore. Toward dark the huntin-- par-
ties all returned to camp without success ; and we found the cat-fish the
principal portion of our supper, having no fresh meat at all.
Our supper over, all parties shortly disposed themselves to sleep as the\
best could. About 10 o'clock, we were all disturbed by a violent thunder
btorm, accompanied by lorr.mts of rain and vivid flashes of li^lruiii- •
VOL.
II. 11
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MISSOURI MOUSE.
the wind arose and blew a gale; all of us were a-foot in a few moments,
and amid some confusion, our guns, loaded with ball, and our ammunition,
were placed under the best covering we could provide, our beds huddled
together under the tent along with them, and some of us crawied in on
top of all, while others sought shelter under the shelving bank of the
river. This storm benefitted us, however, by driving before the gale the
mosquitoes, to keep off which we had in vain made a large flre, before
we laid ourselves down for the night."
As there is little grain of any kind grown in this part of the country,
the Missouri Mouse no doubt exists en the seeds and roots of wild plants
entirely, of which it is able to lay up a store for the winter in holes in the
ground. It may, however, possibly resort to the patches of corn planted
by the squaws of some of the Indian tribes, at the time that grain is ripe
We brought with us from this country, when we returned home, some ears
of a very small corn, (maize,) which ripens early, and bears its fruit near
the ground. Having planted it on our place, we found that it was ad-
vanced enough to be eaten at table as a vegetable, several weeks before
the ordinary kinds of corn known about New- York. We, therefore, dis-
tributed some of the seed among our farming neighbours, and likewise sent
some to England to Lord Derby and other friends, but this was unfortu-
nately lost. We incline to believe that this corn would ripen well in the
climate of England or Scotland. Unluckily, ours has become mixed by
having been planted too near common corn, and is now depreciated or re
duced to nearly the same thing as the latter.
GEOGRAPinCAL DISTRIBUTION.
This species was discovered in the State of Missouri.
GENERAL REMARKiJ.
The Missouri Mouse bears some resemblance to the common and very
widely distributed White-footed Mouse. Its comparatively heavy and
clumt;y form — its large head and short tail have induced us to regard it as
a distinct species. In the mice, shrews, and bats, we have no doubt
several interesting species m ill yet be detected in our country
INDEX.
American Eison, . •
Elk,
Deer,
Black Wolf, .
White do., .
Red Fo)c,
Antelope, Prong-horned,
Annuliited Marmot Squirrel,
Antilocapra, Genus,
Americana, .
Arvicola Pinetorum,
Barking', or Prairie Wolf,
Bassaris, Genus,
Astuta,
Ring-tailed,
Bear, Polar, or white, .
Bison, Genus,
— — — AmerieanxiB, . ,
Anicrican,
Black American Wolf, .
Black-tailed Hnre, .
Black-footed Ferret, ,
Brewers Shrew Mole, .
Brown or Norway Rat, .
Bridled Weasel,' .
BulFalo, , . ,
Canis, Genus,
Lupus (var. Rufus),
Lupus, (var. Ater),
Lupus (var. Albus),
• Latraus,
Cart)lina Shrew, . ,
Cervus Genus,
Page.
. 32
. 83
. 220
. 126
. 156
. 263
. 193
. 213
. 193
. 193
. 216
. 150
. 314
. 314
. 314
. 281
. 32
. 32
. 32
. 126
. 95
. S97
. 173
. 22
. 71
. 32
Cervus Macrotis,
Virginianus,
Alces,
Condylura, Genus,
Cristata,
Common Mouse,
American Deer,
Cougar,
Deer, Wapite, .
Moose, . .
Mule.
Common American,
Didelphis, Genua,
Virginiana,
Eliiphus, Genus, .
Elk, American,
Ermine, . ,
Fells, Genus, . .
Pardalis, ,
-Concolor,
or Virginian,
831
126
240
126
156
150
176
179
Ferret, Black-footod,
Fox, Swift,
Kit, .
Red, . ,
Fo.\ Squirrel, . ,
Franklin's Marmot Squirrel,
Genus Lutra, . ,
Bison, . ,
Procyon, . ,
Elajihus, , ,
Didelphis, . ,
Canis, . ,
Poire.
. 206
220
179
. 139
. 139
277
220
. 305
. 83
179
20''
220
lor
lOT
. A8
. 83
. S3
. 56
258
258
305
297
. 13
. 13
263
133
243
1
S3
74
88
10?
liiO
M h
\im
332
Genus Comljluni,
Sorex,
Ovis, .
■ Cervus, . .
• Aiitilocnpra,
■ Liigomys,
Mei-iones, .
FeliE,
Ursus,
Bassaris,
Golden-bellied Squirrel,
Hare, 'lack-tailed, -
■ Little-chief, .
Wormwood,
Nuttall's, .
Texan, . .
Jumping Mouse, .
Lagomys, Genus, .
Princeps,
Lccontc's Pine Mouse, .
Leopard-Cat,
Lcpus Artemisia,
Calloti.s, .
Nuttallii, .
Little-chief Hare, .
Harvest Mouse, .
Lutra, Genus,
Lynx, Rufus (var. Maculatus),
Texan,
Marmot Squirrel, Franklin's
Annulated
Prairie,
ili'phitis Mesoleuca,
Meriones, Genus, .
HuJsonicus,
Mole, Starnose, . ,
— — — Brewers, .
Mouse, Lccontc's Pino, .
Jumping, .
Little Harvest, .
Common, .
Orange Coloured,
■ Missouri,
Missouri Mouse, .
LNDRX.
Page.
. 139
. nr;
ifi:!
. 17!)
. 19S
214
9M
-i-8
281
. 314
(J7
. 95
. 241
272
. 3U0
. 95
. 251
244
244
2IG
258
272
95
300
5'.44
103
1
Moose Deer,
Mus iMissouriensls,
Dccumanus, ,
— - Huniilis, . ,
Museulus, . ,
(Calomys) Aui^.ius,
Mule Deer, .
Nuitall > Hare, .
Ocelot,
Opossum, Virginian,
Orange Coloured Mouse,
Orange-bellied Squirrel,
Ovis, Genus,
Montana,
Panther, ,
Polar Bear,
Procyon, Genus, .
• Lotor, .
Prairie Wolf,
Marmot Squirrel,
Dog, . .
Prong-horned Antelope,
Putorius Erminea,
— Frenata,
Nigripcs,
Pusillus,
. 293
. 293
. 243
. 213
319
. 18
251
251
. 139
. 173
210
251
. 103
277
303
327
327
Rat, Brown or Norway,
Raccoon,
Red-tailed Squirrel,
Red Texan Wolf,
Red Fox, .
Ring-tailed Bassaris, .
Rocky-Mountain Sheep,
Say's, S(juirrel, .
Least Shrew, ,
Scalops Breweri, .
Sciurus, RubricaudatuB,
Sub-Auratus,
- Caj)istratus,
Sayii,
Shrew, Carolina,
Say's Least,
Page
. 179
. 32:
. 22
103
. 277
. 303
206
. 300
. 858
. 107
303
. 67
2
. 163
. 163
. 305
. S&l
. 74
. 74
. 150
. 319
. 319
. )93
66
. 71
. 29",
100
S3
74
30
840
263
314
1G3
274
145
173
30
67
132
274
17»i
MS
PllgO
. 179
. 32:
. 22
103
. 277
. 303
206
. 300
. 858
. 107
303
. 67
2
. 163
. 163
. 305
. S&l
. 74
. 74
. 150
. 319
. 319
. 193
. S6
71
89:
100
Slicep, Rocky Moiiiitiir',
Skunk, Texiiii,
Small Weasel, . .
Sorcx, Genus,
— — — Parvus,
— — Carolinensia, .
Spcfiuophilus, FrankKnii,
Annulatua,
Ludoviclanus,
Sqiiirrel, Red-tailed,
Oiange-bellied,
— Golden-bellied,
— Fox,
— Say's, . .
Star-iiosc Mole,
Stoat, .
Swift Fox, .
Texan Skunk,
Lynx,
Hare,
INDEX.
Pag'O.
113
Id
. loa
145
145
no
2*8
:ti9
30
67
ft7
132
274
139
66
13
18
293
05
Ursus, Genna, .
Maritinius,
Virginian Opossum,
Deer,
Vulpes, Vclox,
Fulvus, .
VVapite Deer,
Weasel, White, .
Bridled, .
Small,
VVislitonul'i,
White Weasc;, .
1!, a-,
American Wolf,
Wormwood Hare,
Wolf, Black American,
Prairie, or Barking,
White, American,
Red, Texan,
Pago
. 281
. 281
. 107
. 220
. 13
. 203
. 83
. 56
. 71
. 100
. 319
. 56
. 281
. 156
. 27L
. 126
. 150
. 156
. 240
23
74
30
840
263
314
163
274
145
173
30
67
132
274
176
MS
Vulpes Velox, • .
Mephitis Mesoleuca, •
Mus Decumanus,
Sciurus RubricaudatU8.
Bison Americanus, .
Scuirus Sub-auratus, .
Putorius Errainea,
Putorius Frenat;!,
Procyon Lotor,
Lepus Nigrieaudatus, .
Putouius Pusillus,
Mils iliimilis,
Didelpliis Vii'giuiaiia, ,
Swi/l Fox,
Texan Skunk,
Brown, or Norway, Rat,
Red-tailed Squirrel,
Avierican Bison, or Buffalo,
Orange-bellied Squirrel,
White Weasel, Sloai,
Bridled Weasel,
Raccoon,
American Etn, Wajiiti Deer,
Black-laUed Hare,
Small Weasel, .
Little tlirvest Mous-!,
Virginian Ojiossum,
Page.
2
13
18
22
30
33
67
56
71
74
83
95
100
103
^^R
T
1
i*; ii
1
'' !
834
Canis Lupus, (var. Ater.),
Sciurus Capistratua, .
Condylura Cristata .
Sorex Parvus, .
Canis Latrans, .
Canis Lupus (var. Albus),
Ovis Montana, .
Stalops Brewerii,
Sorex Carolinensis, .
Cervus Alces, .
Antilocapra Americana,
Cervus Macrotis,
Spermophilus Annulatus,
Arvieola Pinetoruni,
Cervus Virginianus,
Canis Lupus (var. Rufas),
Lagoniys Princeps,
Spermophilus Franklinii,
Meriones Hudsonicua,
Felis Pardalis, ,
Vulpes Fulvus,
Lepus Artcmesia, ,
Sciurus Sayi,
Mus Musculus,
Ursus Maritimus,
Lynx Rufus (var. Maculatus),
Putorius Nigripes,
Lepus Nuttallii,
llus (Calomys) Aureolus,
Felis Concolor,
Bassaris Astuta,
Spermophilus Ludovieianus,
Mus MLssouriensis, . ,
. Black American Wolf, .
. Fox Squirrel,
. Common Star-nose Mole,
. Say's Least Shrew, . .
. Prairie Wolf,
. White American Wolf,
. Rocky Mountain Sheep, ,
, Brewer's Shrew-Mole, ,
. Carolina Shrew,
. Moose Deer,
. Prong-homed Antelope,
Mule Deer,
Annulated Marmot- Squirrel,
Leconte's Pine Mouse,
Common American Deer (fawn).
Red Texan Wolf,
Little-chief Hare,
Franklin's Marmot- Squirrel,
Jumping Mouse,
Ocelot, or Leopard Cat,
American Red Fox,
Wormwood Hare,
Say's Squirrel, , . .
Common Mouse, . .
Polar Bfar,
Texan Lynx,
Black-footed Ferret,
Nuttall's Hare, .
Orange Coloured Mouse,
Cougar, ....
Ring-tailed Bassaris, .
Prairie Dog, Prairie Marmot- Squirrel,
Missouri Mouse, , . ,
Page
. lat
133
139
, 145
, 150
15()
163
173
176
179
193
206
213
216
220
240
244
248
251
258
263
272
274
277
281
293
297
300
303
305
314
319
TABLE OF GENERA DESCRIBED m THIS VOLUME.
'Jenus Lutra,
Page.
1
Genus Ovis,
Pom.
163
" Bison,
32
Cervus
179
" Procyon,
74
Antilocapra,
193
« Ehipliu.s
83
Lngoniys,
244
" Didelpliis,
107
lleriones,
251
" C:inis,
126
Felis,
258
" Condylura,
139
Ursus,
281
" Sorex,
145
((
Bassaris, . .
. 314
Page.
. lit
133
139
. 145
. 150
. 150
. 163
, 173
, 176
, 179
. 193
206
213
216
220
210
244
248
251
258
263
272
S74
877
281
293
297
300
303
305
314
319
897
\
Pwre.
163
179
193
244
251
258
281
314 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.43860313296318054, "perplexity": 20036.353078337488}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 5, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-32/segments/1438042992543.60/warc/CC-MAIN-20150728002312-00011-ip-10-236-191-2.ec2.internal.warc.gz"} |
https://sabre.lngs.infn.it/ | Results from astronomical observations accumulated in the last decades provide overwhelming evidence for the existence of a large amount of dark matter in the Universe. The majority of the mass in our universe is composed of non-luminous, non-baryonic matter. Despite dark matter’s dominance, its nature remains unknown. To directly detect dark matter and identify its nature is one of the greatest goals in modern physics.
SABRE (Sodium Iodide with Active Background Rejection Experiment) aims at the direct detection of dark matter particles via their scattering off nuclei. A fundamental model-independent signature for dark matter particles interacting on a ground-based detector is the annual modulation of the expected interaction rate. Such modulation is due to the change of the Earth’s velocity relative to the galactic halo reference frame, with maximum interaction rate around June 2nd. SABRE aims to detect the annual modulation by an array of high radio-purity thallium-doped sodium iodide (NaI(Tl)) scintillating crystals deployed in a liquid scintillator, which works as an active anti-coincidence veto.
The crystal radio-purity is a fundamental feature in SABRE. Therefore, a proof-of-principle measurement is planned to characterize the first 5 kg high purity crystals produced by the Collaboration. In addition, SABRE scientific program includes the deployment of two similar detectors: one in the Northern hemisphere at Laboratori Nazionali del Gran Sasso (LNGS), in Italy, and one in the Southern hemisphere at the Stawell Underground Physics Laboratory (SUPL), in Australia. This double measurement will improve disentangling any subtle effect due to cosmic muons, which have an opposite seasonal modulation in the two hemispheres. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8384616374969482, "perplexity": 1537.3257536576887}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 5, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-17/segments/1618038879374.66/warc/CC-MAIN-20210419111510-20210419141510-00300.warc.gz"} |
https://www.science.gov/topicpages/n/non-equilibrium+air+plasma.html | #### Sample records for non-equilibrium air plasma
1. Non-equilibrium Air Plasma for Wound Bleeding Control
Kuo, Spencer P.; Chen, Cheng-Yen; Lin, Chuan-Shun; Chiang, Shu-Hsing
A low temperature non-equilibrium air plasma spray is tested as a blood coagulator. Emission spectroscopy of the plasma effluent indicates that it carries abundant reactive atomic oxygen (RAO), which can activate erythrocyte - platelet interactions to enhance blood coagulation for plug formation. Tests of the device for wound bleeding control were performed on pigs. Four types of wounds, straight cut and cross cut in the ham area, a hole in an ear saphenous vein, and a cut to an ear artery, were examined. The results showed that this plasma spray could effectively stop the bleeding and reduced the bleeding time considerably. Post-Operative observation of straight cut and cross cut wound healing was carried out. It was found that the plasma treatment had a positive impact on wound healing, in particular, of the cross cut wound; its healing time was shortened by a half.
2. Chemical kinetics and relaxation of non-equilibrium air plasma generated by energetic photon and electron beams
Maulois, Melissa; Ribière, Maxime; Eichwald, Olivier; Yousfi, Mohammed; Azaïs, Bruno
2016-04-01
The comprehension of electromagnetic perturbations of electronic devices, due to air plasma-induced electromagnetic field, requires a thorough study on air plasma. In the aim to understand the phenomena at the origin of the formation of non-equilibrium air plasma, we simulate, using a volume average chemical kinetics model (0D model), the time evolution of a non-equilibrium air plasma generated by an energetic X-ray flash. The simulation is undertaken in synthetic air (80% N2 and 20% O2) at ambient temperature and atmospheric pressure. When the X-ray flash crosses the gas, non-relativistic Compton electrons (low energy) and a relativistic Compton electron beam (high energy) are simultaneously generated and interact with the gas. The considered chemical kinetics scheme involves 26 influent species (electrons, positive ions, negative ions, and neutral atoms and molecules in their ground or metastable excited states) reacting following 164 selected reactions. The kinetics model describing the plasma chemistry was coupled to the conservation equation of the electron mean energy, in order to calculate at each time step of the non-equilibrium plasma evolution, the coefficients of reactions involving electrons while the energy of the heavy species (positive and negative ions and neutral atoms and molecules) is assumed remaining close to ambient temperature. It has been shown that it is the relativistic Compton electron beam directly created by the X-ray flash which is mainly responsible for the non-equilibrium plasma formation. Indeed, the low energy electrons (i.e., the non-relativistic ones) directly ejected from molecules by Compton collisions contribute to less than 1% on the creation of electrons in the plasma. In our simulation conditions, a non-equilibrium plasma with a low electron mean energy close to 1 eV and a concentration of charged species close to 1013 cm-3 is formed a few nanoseconds after the peak of X-ray flash intensity. 200 ns after the flash
3. Non-Equilibrium Transitions of Heliospheric plasma
2011-12-01
Recent advances in Space Physics theory have established the connection between non-extensive Statistical Mechanics and space plasmas by providing a theoretical basis for the empirically derived kappa distributions commonly used to describe the phase space distribution functions of these systems [1]. The non-equilibrium temperature and the kappa index that govern these distributions are the two independent controlling parameters of non-equilibrium systems [1-3]. The significance of the kappa index is primarily given by its role in identifying the non-equilibrium stationary states, and measuring their "thermodynamic distance" from thermal equilibrium [4], while its physical meaning is connected to the correlation between the system's particles [5]. For example, analysis of the IBEX high Energetic Neutral Atom spectra [6] showed that the vast majority of measured kappa indices are between ~1.5 and ~2.5, consistent with the far-equilibrium "cavity" of minimum entropy discovered by Livadiotis & McComas [2]. Spontaneous procedures that can increase the entropy, move the system gradually toward equilibrium, that is the state with the maximum (infinite) kappa index. Other external factors that may decrease the entropy, move the system back to states further from equilibrium where the kappa indices are smaller. Newly formed pick-up ions can play this critical role in the solar wind and other space plasmas. We have analytically shown that their highly ordered motion can reduce the average entropy in the plasma beyond the termination shock, inside the inner heliosheath [7]. Non-equilibrium transitions have a key role in understanding the governing thermodynamical processes of space plasmas. References 1. Livadiotis, G., & McComas, D. J. 2009, JGR, 114, 11105. 2. Livadiotis, G., & McComas, D. J. 2010a, ApJ, 714, 971. 3. Livadiotis, G., & McComas, D. J. 2010c, in AIP Conf. Proc. 9, Pickup Ions Throughout the Heliosphere and Beyond, ed. J. LeRoux, V. Florinski, G. P. Zank, & A
4. Radiation temperature of non-equilibrium plasmas
SciTech Connect
Arunasalam, V.
1991-07-01
In fusion devices measurements of the radiation temperature T{sub r} ({omega}, k) near the electron cyclotron frequency {omega}{sub C} and the second harmonic 2{omega}{sub C} in directions nearly perpendicular to the confining magnetic field B (i.e., k {approx} k {perpendicular}) serve to map out the electron temperature profiles T{sub e}(r,t). For optically thick plasma at thermodynamic equilibrium T{sub r} = T{sub e}. However, there is increasing experimental evidence for the presence of non-equilibrium electron distributions (such as a drifting Maxwellian with appreciable values of the streaming parameter {omicron} = v{sub d}/v{sub t}, a bi- Maxwellian, and anisotropic Maxwellian with T {perpendicular} {ne} T {parallel}, etc.,) in tokamak plasmas, especially in the presence of radio-frequency heating. Here, we examine (both non-relativistically and relativistically) the dependence of T{sub r} on {omicron}, T{perpendicular}/T{parallel}, T{sub h}/T{sub b}, n{sub h}/n{sub b}etc., where n{sub b}, n{sub h}, T{sub b}, T{sub h} are the densities and temperatures, respectively, of the bulk and the hot components of the bi-Maxwellian plasma. Our bi-Maxwellian results predict that the ratio T{sub r}/T{sub e} is a very sensitive function of the ratios n{sub h}/n{sub b} and T{sub h}/T{sub b}. Further, these relativistic and non-relativistic results satisfy the well-known limit c {yields} {infinity} correspondence principle'', showing that the intensity of the emission and absorption line is independent of the line broadening mechanism. 44 refs., 2 figs.
5. Non-equilibrium plasma reactors for organic solvent destruction
SciTech Connect
Yang, C.L.; Beltran, M.R.; Kravets, Z.
1997-12-31
Two non-equilibrium plasma reactors were evaluated for their ability to destroy three widely used organic solvents, i.e., 2-butanone, toluene and ethyl acetate. The catalyzed plasma reactor (CPR) with 6 mm glass beads destroys 98% of 50 ppm toluene in air at 24 kV/cm and space velocities of 1,400 v/v/hr. Eighty-five percent of ethyl acetate and 2-butanone are destroyed under the same conditions. The tubular plasma reactor (TPR) has an efficiency of 10% to 20% lower than that of a CPR under the same conditions. The 1,400 v/v/hr in a CPR is equal to a residence time of 2.6 seconds in a TPR. The operating temperatures, corona characteristics, as well as the kinetics of VOC destruction in both TPR and CPR were studied.
6. Non-equilibrium plasma prevention of Schistosoma japonicum transmission
PubMed Central
Wang, Xing-Quan; Wang, Feng-Peng; Chen, Wei; Huang, Jun; Bazaka, Kateryna; Ostrikov, Kostya (Ken)
2016-01-01
Schistosoma japonicum is a widespread human and animal parasite that causes intestinal and hepatosplenic schistosomiasis linked to colon, liver and bladder cancers, and anemia. Estimated 230 million people are currently infected with Schistosoma spp, with 779 million people at risk of contracting the parasite. Infection occurs when a host comes into contact with cercariae, a planktonic larval stage of the parasite, and can be prevented by inactivating the larvae, commonly by chemical treatment. We investigated the use of physical non-equilibrium plasma generated at atmospheric pressure using custom-made dielectric barrier discharge reactor to kill S. japonicum cercariae. Survival rate decreased with treatment time and applied power. Plasmas generated in O2 and air gas discharges were more effective in killing S. japonicum cercariae than that generated in He, which is directly related to the mechanism by which cercariae are inactivated. Reactive oxygen species, such as O atoms, abundant in O2 plasma and NO in air plasma play a major role in killing of S. japonicum cercariae via oxidation mechanisms. Similar level of efficacy is also shown for a gliding arc discharge plasma jet generated in ambient air, a system that may be more appropriate for scale-up and integration into existing water treatment processes. PMID:27739459
7. Non-equilibrium plasma prevention of Schistosoma japonicum transmission
Wang, Xing-Quan; Wang, Feng-Peng; Chen, Wei; Huang, Jun; Bazaka, Kateryna; Ostrikov, Kostya (Ken)
2016-10-01
Schistosoma japonicum is a widespread human and animal parasite that causes intestinal and hepatosplenic schistosomiasis linked to colon, liver and bladder cancers, and anemia. Estimated 230 million people are currently infected with Schistosoma spp, with 779 million people at risk of contracting the parasite. Infection occurs when a host comes into contact with cercariae, a planktonic larval stage of the parasite, and can be prevented by inactivating the larvae, commonly by chemical treatment. We investigated the use of physical non-equilibrium plasma generated at atmospheric pressure using custom-made dielectric barrier discharge reactor to kill S. japonicum cercariae. Survival rate decreased with treatment time and applied power. Plasmas generated in O2 and air gas discharges were more effective in killing S. japonicum cercariae than that generated in He, which is directly related to the mechanism by which cercariae are inactivated. Reactive oxygen species, such as O atoms, abundant in O2 plasma and NO in air plasma play a major role in killing of S. japonicum cercariae via oxidation mechanisms. Similar level of efficacy is also shown for a gliding arc discharge plasma jet generated in ambient air, a system that may be more appropriate for scale-up and integration into existing water treatment processes.
8. Experimental approaches for studying non-equilibrium atmospheric plasma jets
SciTech Connect
Shashurin, A.; Keidar, M.
2015-12-15
This work reviews recent research efforts undertaken in the area non-equilibrium atmospheric plasma jets with special focus on experimental approaches. Physics of small non-equilibrium atmospheric plasma jets operating in kHz frequency range at powers around few Watts will be analyzed, including mechanism of breakdown, process of ionization front propagation, electrical coupling of the ionization front with the discharge electrodes, distributions of excited and ionized species, discharge current spreading, transient dynamics of various plasma parameters, etc. Experimental diagnostic approaches utilized in the field will be considered, including Rayleigh microwave scattering, Thomson laser scattering, electrostatic streamer scatterers, optical emission spectroscopy, fast photographing, etc.
9. Plasma diagnostics of non-equilibrium atmospheric plasma jets
Shashurin, Alexey; Scott, David; Keidar, Michael; Shneider, Mikhail
2014-10-01
Intensive development and biomedical application of non-equilibrium atmospheric plasma jet (NEAPJ) facilitates rapid growth of the plasma medicine field. The NEAPJ facility utilized at the George Washington University (GWU) demonstrated efficacy for treatment of various cancer types (lung, bladder, breast, head, neck, brain and skin). In this work we review recent advances of the research conducted at GWU concerned with the development of NEAPJ diagnostics including Rayleigh Microwave Scattering setup, method of streamer scattering on DC potential, Rogowski coils, ICCD camera and optical emission spectroscopy. These tools allow conducting temporally-resolved measurements of plasma density, electrical potential, charge and size of the streamer head, electrical currents flowing though the jet, ionization front propagation speed etc. Transient dynamics of plasma and discharge parameters will be considered and physical processes involved in the discharge will be analyzed including streamer breakdown, electrical coupling of the streamer tip with discharge electrodes, factors determining NEAPJ length, cross-sectional shape and propagation path etc.
10. Spacecraft Sterilization Using Non-Equilibrium Atmospheric Pressure Plasma
NASA Technical Reports Server (NTRS)
Cooper, Moogega; Vaze, Nachiket; Anderson, Shawn; Fridman, Gregory; Vasilets, Victor N.; Gutsol, Alexander; Tsapin, Alexander; Fridman, Alexander
2007-01-01
As a solution to chemically and thermally destructive sterilization methods currently used for spacecraft, non-equilibrium atmospheric pressure plasmas are used to treat surfaces inoculated with Bacillus subtilis and Deinococcus radiodurans. Evidence of significant morphological changes and reduction in viability due to plasma exposure will be presented, including a 4-log reduction of B. subtilis after 2 minutes of dielectric barrier discharge treatment.
11. Non-equilibrium Flows of Reacting Air Components in Nozzles
Bazilevich, S. S.; Sinitsyn, K. A.; Nagnibeda, E. A.
2008-12-01
The paper presents the results of the investigation of non-equilibrium flows of reacting air mixtures in nozzles. State-to-state approach based on the solution of the equations for vibrational level populations of molecules and atomic concentrations coupled to the gas dynamics equations is used. For the 5-component air mixture (N2, O2, NO, N, O) non-equilibrium distributions and gasdynamical parameters are calculated for different conditions in a nozzle throat. The influence of various kinetic processes on distributions and gas dynamics parameters is studied. The paper presents the comparison of the results with ones obtained for binary mixtures of molecules and atoms and various models of elementary processes.
12. Non Equilibrium Fluctuations In The Degenerated Polarizable Plasma
SciTech Connect
Belyi, V. V.; Kukharenko, Yu. A.
2009-04-23
The quantum plasma of Bose and Fermi particles is considered. A scheme of equation linearization for density matrix with the exchange interaction taken in account is proposed and the equation solution is found. An expression for Hartree- Fock dielectric permittivity with the exchange interaction is obtained. This interaction is taken into account in the exchange scattering amplitude. With the use of obtained solutions the non-equilibrium spectral function of electric field fluctuations in presence of exchange interaction and medium polarization is found. It is shown that in the state of thermodynamic equilibrium a Fluctuation-Dissipation Theorem holds. An expression for the system's response to an external electric field in presence of exchange interaction is given.
13. Interaction of non-equilibrium oxygen plasma with sintered graphite
Cvelbar, Uroš
2013-03-01
Samples made from sintered graphite with grain size of about 10 μm were exposed to highly non-equilibrium oxygen plasma created in a borosilicate glass tube by an electrodeless RF discharge. The density of charged particles was about 7 × 1015 m-3 and the neutral oxygen atom density 6 × 1021 m-3. The sample temperature was determined by a calibrated IR detector while the surface modifications were quantified by XPS and water drop techniques. The sample surface was rapidly saturated with carbonyl groups. Prolonged treatment of samples caused a decrease in concentration of the groups what was explained by thermal destruction. Therefore, the created functional groups were temperature dependent. The heating of samples resulted in extensive chemical interaction between the O atoms and samples what was best monitored by decreasing of the O atom density with increasing sample temperature. The saturation with functional groups could be restored only after cooling down of the samples and repeated short plasma treatment at low temperature.
14. Numerical Simulation of Non-Equilibrium Plasma Discharge for High Speed Flow Control
Balasubramanian, Ramakrishnan; Anandhanarayanan, Karupannasamy; Krishnamurthy, Rajah; Chakraborty, Debasis
2016-06-01
Numerical simulation of hypersonic flow control using plasma discharge technique is carried out using an in-house developed code CERANS-TCNEQ. The study is aimed at demonstrating a proof of concept futuristic aerodynamic flow control device. The Kashiwa Hypersonic and High Temperature wind tunnel study of plasma discharge over a flat plate had been considered for numerical investigation. The 7-species, 18-reaction thermo-chemical non-equilibrium, two-temperature air-chemistry model due Park is used to model the weakly ionized flow. Plasma discharge is modeled as Joule heating source terms in both the translation-rotational and vibrational energy equations. Comparison of results for plasma discharge at Mach 7 over a flat plate with the reference data reveals that the present study is able to mimic the exact physics of complex flow such as formation of oblique shock wave ahead of the plasma discharge region with a resultant rise in surface pressure and vibrational temperature up to 7000 K demonstrating the use of non-equilibrium plasma discharge for flow control at hypersonic speeds.
15. Synthesis of Silane and Silicon in a Non-equilibrium Plasma Jet
NASA Technical Reports Server (NTRS)
Calcote, H. F.
1978-01-01
The original objective of this program was to determine the feasibility of high volume, low-cost production of high purity silane or solar cell grade silicon using a non equilibrium plasma jet. The emphasis was changed near the end of the program to determine the feasibility of preparing photovoltaic amorphous silicon films directly using this method. The non equilibrium plasma jet should be further evaluated as a technique for producing high efficiency photovoltaic amorphous silicon films.
16. Numerical analysis of the non-equilibrium plasma flow in the gaseous electronics conference reference reactor
Bijie, Yang; Ning, Zhou; Quanhua, Sun
2016-01-01
The capacitively coupled plasma in the gaseous electronics conference reference reactor is numerically investigated for argon flow using a non-equilibrium plasma fluid model. The finite rate chemistry is adopted for the chemical non-equilibrium among species including neutral metastable, whereas a two-temperature model is employed to resolve the thermal non-equilibrium between electrons and heavy species. The predicted plasma density agrees very well with experimental data for the validation case. A strong thermal non-equilibrium is observed between heavy particles and electrons due to its low collision frequency, where the heavy species remains near ambient temperature for low pressure and low voltage conditions (0.1 Torr, 100 V). The effects of the operating parameters on the ion flux are also investigated, including the electrode voltage, chamber pressure, and gas flow rate. It is found that the ion flux can be increased by either elevating the electrode voltage or lowering the gas pressure. Project supported by the National Natural Science Foundation of China (Nos. 11372325, 11475239).
17. Non-linear optical diagnostic studies of high pressure non-equilibrium plasmas
Lempert, Walter
2012-10-01
Picosecond Coherent Anti-Stokes Raman Spectroscopy (CARS) is used for study of vibrational energy loading and relaxation kinetics in high pressure nitrogen and air nsec pulsed non-equilibrium plasmas in a pin-to-pin geometry. It is found that ˜33% of total discharge energy in a single pulse in air at 100 torr couples directly to nitrogen vibration by electron impact, in good agreement with master equation modeling predictions. However in the afterglow the total quanta in vibrational levels 0 -- 9 is found to increase by a factor of approximately 2 and 4 in nitrogen and air, respectively, a result in direct contrast to modeling results which predict the total number of quanta to be essentially constant. More detailed comparison between experiment and model show that the VDF predicted by the model during, and directly after, the discharge pulse is in good agreement with that determined experimentally, however for time delays exceeding ˜10 μsec the experimental and predicted VDFs diverge rapidly, particularly for levels v = 2 and greater. Specifically modeling predicts a rapid drop in population of high levels due to net downward V-V energy transfer whereas the experiment shows an increase in population in levels 2 and 3 and approximately constant population for higher levels. It is concluded that a collisional process is feeding high vibrational levels at a rate which is comparable to the rate at which population of the high levels is lost due to net downward V-V. A likely candidate for the source of additional vibrational quanta is the quenching of metastable electronic states of nitrogen to highly excited vibrational levels of the ground electronic state. Recent progress in the development and application of psec coherent Raman electric field and spontaneous Thomson scattering diagnostics for study of high pressure nsec pulsed plasmas will also be presented.
18. A numerical model of non-equilibrium thermal plasmas. II. Governing equations
SciTech Connect
Li HePing; Zhang XiaoNing; Xia Weidong
2013-03-15
Governing equations and the corresponding physical properties of the plasmas are both prerequisites for studying the fundamental processes in a non-equilibrium thermal plasma system numerically. In this paper, a kinetic derivation of the governing equations used for describing the complicated thermo-electro-magneto-hydrodynamic-chemical coupling effects in non-equilibrium thermal plasmas is presented. This derivation, which is achieved using the Chapman-Enskog method, is completely consistent with the theory of the transport properties reported in the previous paper by the same authors. It is shown, based on this self-consistent theory, that the definitions of the specific heat at constant pressure and the reactive thermal conductivity of two-temperature plasmas are not necessary. The governing equations can be reduced to their counterparts under local thermodynamic equilibrium (LTE) and local chemical equilibrium (LCE) conditions. The general method for the determination of the boundary conditions of the solved variables is also discussed briefly. The two papers establish a self-consistent physical-mathematical model that describes the complicated physical and chemical processes in a thermal plasma system for the cases both in LTE or LCE conditions and under non-equilibrium conditions.
19. Analysis of non-equilibrium phenomena in inductively coupled plasma generators
Zhang, W.; Lani, A.; Panesi, M.
2016-07-01
This work addresses the modeling of non-equilibrium phenomena in inductively coupled plasma discharges. In the proposed computational model, the electromagnetic induction equation is solved together with the set of Navier-Stokes equations in order to compute the electromagnetic and flow fields, accounting for their mutual interaction. Semi-classical statistical thermodynamics is used to determine the plasma thermodynamic properties, while transport properties are obtained from kinetic principles, with the method of Chapman and Enskog. Particle ambipolar diffusive fluxes are found by solving the Stefan-Maxwell equations with a simple iterative method. Two physico-mathematical formulations are used to model the chemical reaction processes: (1) A Local Thermodynamics Equilibrium (LTE) formulation and (2) a thermo-chemical non-equilibrium (TCNEQ) formulation. In the TCNEQ model, thermal non-equilibrium between the translational energy mode of the gas and the vibrational energy mode of individual molecules is accounted for. The electronic states of the chemical species are assumed in equilibrium with the vibrational temperature, whereas the rotational energy mode is assumed to be equilibrated with translation. Three different physical models are used to account for the coupling of chemistry and energy transfer processes. Numerical simulations obtained with the LTE and TCNEQ formulations are used to characterize the extent of non-equilibrium of the flow inside the Plasmatron facility at the von Karman Institute. Each model was tested using different kinetic mechanisms to assess the sensitivity of the results to variations in the reaction parameters. A comparison of temperatures and composition profiles at the outlet of the torch demonstrates that the flow is in non-equilibrium for operating conditions characterized by pressures below 30 000 Pa, frequency 0.37 MHz, input power 80 kW, and mass flow 8 g/s.
20. Search for a non-equilibrium plasma in the merging galaxy cluster Abell 754
Inoue, Shota; Hayashida, Kiyoshi; Ueda, Shutaro; Nagino, Ryo; Tsunemi, Hiroshi; Koyama, Katsuji
2016-06-01
Abell 754 is a galaxy cluster in which an ongoing merger is evident on the plane of the sky, from the southeast to the northwest. We study the spatial variation of the X-ray spectra observed with Suzaku along the merging direction, centering on the Fe Ly α/Fe He α line ratio to search for possible deviation from ionization equilibrium. Fitting with a single-temperature collisional non-equilibrium plasma model shows that the electron temperature increases from the southeast to the northwest. The ionization parameter is consistent with that in equilibrium (net > 1013 s cm-3) except for the specific region with the highest temperature (kT=13.3_{-1.1}^{+1.4}keV) where n_et=10^{11.6_{-1.7}^{+0.6}}s cm-3. The elapsed time from the plasma heating estimated from the ionization parameter is 0.36-76 Myr at the 90% confidence level. This timescale is quite short but consistent with the traveling time of a shock to pass through that region. We thus interpret that the non-equilibrium ionization plasma in Abell 754 observed is a remnant of the shock heating in the merger process. However, we note that the X-ray spectrum of the specific region where the non-equilibrium is found can also be fitted with a collisional ionization plasma model with two temperatures, low kT=4.2^{+4.2}_{-1.5}keV and very high kT >19.3 keV. The very high temperature component is alternatively fitted with a power-law model. Either of these spectral models is interpreted as a consequence of the ongoing merger process as in the case of the non-equilibrium ionization plasma.
1. Multi-Modality Pulsed AC Source for Medical Applications of Non-Equilibrium Plasmas
Friedrichs, Daniel; Gilbert, James
2014-10-01
A burgeoning field has developed around the use of non-equilibrium (cold'') plasmas for various medical applications, including wound treatment, surface sterilization, non-thermal hemostasis, and selective cell destruction. Proposed devices typically utilize pulsed DC power sources, which have no other therapeutic utility, and may encounter significant regulatory restrictions regarding their safety for use in patient care. Additionally, dedicated capital equipment is difficult for healthcare facilities to justify. In this work, we have demonstrated for the first time the generation of non-equilibrium plasma using pulsed AC output from a specially-designed electrosurgical generator. The ability to power novel non-equilibrium plasma devices from a piece of equipment already ubiquitous in operating theatres should significantly reduce the barriers to adoption of plasma devices. We demonstrate the ability of a prototype device, coupled to this source, to reduce bacterial growth in vitro. Such a system could allow a single surgical instrument to provide both non-thermal sterilization and thermal tissue dissection.
2. Gas-Liquid Interfacial Non-Equilibrium Plasmas for Structure Controlled Nanoparticles
Kaneko, Toshiro
2013-10-01
Plasmas generated in liquid or in contact with liquid have attracted much attention as a novel reactive field in the nano-bio material creation because the brand-new chemical and biological reactions are yielded at the gas-liquid interface, which are induced by the physical actions of the non-equilibrium plasmas. In this study, first, size- and structure-controlled gold nanoparticles (AuNPs) covered with DNA are synthesized using a pulse-driven gas-liquid interfacial discharge plasma (GLIDP) for the application to next-generation drug delivery systems. The size and assembly of the AuNPs are found to be easily controlled by changing the plasma parameters and DNA concentration in the liquid. On the other hand, the mono-dispersed, small-sized, and interval-controlled AuNPs are synthesized by using the carbon nanotubes (CNTs) as a template, where the CNTs are functionalized by the ion and radical irradiation in non-equilibrium plasmas. These new materials are now widely applied to the solar cell, optical devices, and so on. Second, highly-ordered periodic structures of the AuNPs are formed by transcribing the periodic plasma structure to the surface of the liquid, where the spatially selective synthesis of the AuNPs is realized. This phenomenon is well explained by the reduction and oxidation effects of the radicals which are generated by the non-equilibrium plasma irradiation to the liquid and resultant dissociation of the liquid. In addition, it is attempted to form nano- or micro-scale periodic structures of the AuNPs based on the self-organizing behavior of turbulent plasmas generated by the nonlinear development of plasma fluctuations at the gas-liquid interface.
3. Non-Equilibrium Reaction Kinetics of an Atmospheric Pressure Microwave-Driven Plasma Torch: a Global Model
Parsey, Guy; Güçlü, Yaman; Verboncoeur, John; Christlieb, Andrew
2013-09-01
In the context of microwave-coupled plasmas, within atmospheric pressure nozzle geometries, we have developed a kinetic global model (KGM) framework designed for quick exploration of parameter space. Our final goal is understanding key reaction pathways within non-equilibrium plasma assisted combustion (PAC). In combination with a Boltzmann equation solver, kinetic plasma and gas-phase chemistry are solved with iterative feedback to match observed bulk conditions from experiments; using a parameterized non-equilibrium electron energy distribution function (EEDF) to define electron-impact processes. The KGM is first applied to argon and air'' systems as a means of assessing the soundness of made assumptions. The test with air'' greatly increases the complexity by incorporating a plethora of excited states (e.g. translational and vibrational excitations) and providing new reaction pathways. The KGM is then applied to plasma driven combustion mechanisms (e.g. H2 or CH4 with an oxidizer source) which drastically increases the range of reaction time-scales. As the reaction mechanisms become more complex, availability of data will begin to hinder model physicality, requiring analytical and/or empirical treatment of gaps in data to maintain completeness of the reaction mechanisms. Supported by AFOSR and an MSU SPG.
4. Reactive species in non-equilibrium atmospheric-pressure plasmas: Generation, transport, and biological effects
Lu, X.; Naidis, G. V.; Laroussi, M.; Reuter, S.; Graves, D. B.; Ostrikov, K.
2016-05-01
Non-equilibrium atmospheric-pressure plasmas have recently become a topical area of research owing to their diverse applications in health care and medicine, environmental remediation and pollution control, materials processing, electrochemistry, nanotechnology and other fields. This review focuses on the reactive electrons and ionic, atomic, molecular, and radical species that are produced in these plasmas and then transported from the point of generation to the point of interaction with the material, medium, living cells or tissues being processed. The most important mechanisms of generation and transport of the key species in the plasmas of atmospheric-pressure plasma jets and other non-equilibrium atmospheric-pressure plasmas are introduced and examined from the viewpoint of their applications in plasma hygiene and medicine and other relevant fields. Sophisticated high-precision, time-resolved plasma diagnostics approaches and techniques are presented and their applications to monitor the reactive species and plasma dynamics in the plasma jets and other discharges, both in the gas phase and during the plasma interaction with liquid media, are critically reviewed. The large amount of experimental data is supported by the theoretical models of reactive species generation and transport in the plasmas, surrounding gaseous environments, and plasma interaction with liquid media. These models are presented and their limitations are discussed. Special attention is paid to biological effects of the plasma-generated reactive oxygen and nitrogen (and some other) species in basic biological processes such as cell metabolism, proliferation, survival, etc. as well as plasma applications in bacterial inactivation, wound healing, cancer treatment and some others. Challenges and opportunities for theoretical and experimental research are discussed and the authors' vision for the emerging convergence trends across several disciplines and application domains is presented to
5. Extremely non-equilibrium oxygen plasma for direct synthesis of metal oxide nanowires on metallic substrates
Mozetic, Miran
2011-05-01
A promising method for the synthesis of metal oxide nanowires is based on the application of the extremely non-equilibrium gaseous environment found in oxygen plasma created by some types of discharges. The kinetic temperature of neutral gas is kept close to the room temperature, the electron temperature is a few eV, the ionization fraction below 10-6 and the dissociation fraction close to 100%. Plasma with such characteristics is obtained using electrodeless high frequency discharges driven by radiofrequency or microwave generators. Plasma parameters such as the electron density and energy distribution function, the Debye length, the dissociation and ionization fractions, the density of negatively charged molecules, the ratio between the positively charged molecules and atoms and the distribution of atoms and molecules over excited states depend on discharge parameters. The most important discharge parameters are the generator power, frequency and coupling, the purity and pressure of working gas and the gas flow, the dimensions of the discharge chamber, the materials facing plasma, the residual atmosphere, and, usually very importantly though often neglected, the properties of the samples mounted into a discharge chamber. Proper construction of the experimental system for the synthesis of metal oxide nanowires allows for almost 100% dissociation fraction and thus extremely rapid growing of nanowires. The particularities of oxygen plasma as well as real-time monitoring of the dissociation fraction are elaborated in this contribution. The lack of reliable experimental results on characterization of extremely non-equilibrium oxygen plasma is stressed.
6. Laser induced plasma on copper target, a non-equilibrium model
SciTech Connect
Oumeziane, Amina Ait Liani, Bachir; Parisse, Jean-Denis
2014-02-15
The aim of this work is to present a comprehensive numerical model for the UV laser ablation of metal targets, it focuses mainly on the prediction of laser induced plasma thresholds, the effect of the laser-plasma interaction, and the importance of the electronic non-equilibrium in the laser induced plume and its expansion in the background gas. This paper describes a set of numerical models for laser-matter interaction between 193-248 and 355 nm lasers and a copper target. Along with the thermal effects inside the material resulting from the irradiation of the latter with the pulsed laser, the laser-evaporated matter interaction and the plasma formation are thoroughly modelled. In the laser induced plume, the electronic nonequilibrium and the laser beam absorption have been investigated. Our calculations of the plasmas ignition thresholds on copper targets have been validated and compared to experimental as well as theoretical results. Comparison with experiment data indicates that our results are in good agreement with those reported in the literature. Furthermore, the inclusion of electronic non-equilibrium in our work indicated that this important process must be included in models of laser ablation and plasma plume formation.
7. Synthesis of silane and silicon in a non-equilibrium plasma jet
NASA Technical Reports Server (NTRS)
Calcote, H. F.; Felder, W.
1977-01-01
The feasibility of using a non-equilibrium hydrogen plasma jet as a chemical synthesis tool was investigated. Four possible processes were identified for further study: (1) production of polycrystalline silicon photovoltaic surfaces, (2) production of SiHCl3 from SiCl4, (3) production of SiH4 from SiHCl3, and (4) purification of SiCl4 by metal impurity nucleation. The most striking result was the recognition that the strongly adhering silicon films, amorphous or polycrystalline, produced in our studies could be the basis for preparing a photovoltaic surface directly; this process has potential advantages over other vapor deposition processes.
8. Investigation of non-equilibrium electron-hole plasma in nanowires by THz spectroscopy
Cirlin, G. E.; Buyskih, A. C.; Bouravlev, A. D.; Samsonenko, Yu. B.; Kaliteevski, M. A.; Gallant, A. J.; Zeze, D.
2016-05-01
Efficient emission of THz radiation by AlGaAs nanowires via excitation of photocurrent by femtosecond optical pulses in nanowires was observed. Dynamics of photoinduced charge carrier was studied via influence of electron-hole plasma on THz radiation by optical pump THz probe method. It was found that characteristic time of screening of contact field is about 15 ps. Recombination of non-equilibrium occurs in two stages: fast recombination of free electron and holes (with relaxation time about 700 ps), and slow recombination (with relaxation time about 15 ns), which involves a capture of electrons and holes on the defects of crystalline structure of nanowires.
9. Application of non-equilibrium plasmas in treatment of wool fibers and seeds
Petrović, Zoran
2003-10-01
While large effort is under way to achieve stable, large area, non-equilibrium plasma reactors operating at atmospheric pressure we should still consider application of low pressure reactors, which provide well defined, easily controlled reactive plasmas. Therefore, the application of low pressure rf plasmas for the treatment of wool and seed was investigated. The studies were aimed at establishing optimal procedure to achieve better wettability, dyeability and printability of wool. Plasma treatment led to a modification of wool fiber topography and formation of new polar functional groups inducing the increase of wool hydrophylicity. Plasma activation of fiber surface was also used to achieve better binding of biopolymer chitosan to wool in order to increase the content of favorable functional groups and thus improving sorption properties of recycled wool fibers for heavy metal ions and acid dyes. In another study, the increase of germination percentage of seeds induced by plasmas was investigated. We have selected dry (unimbibed) Empress tree seeds (Paulownia tomentosa Steud.). Empress tree seed has been studied extensively and its mechanism of germination is well documented. Germination of these seeds is triggered by light in a limited range of wavelengths. Interaction between activated plasma particles and seed, inside the plasma reactor, leads to changes in its surface topography, modifies the surface layer and increases the active surface area. Consequently, some bioactive nitrogeneous compounds could be bound to the activated surface layer causing the increment of germination percentage.
10. A tightly coupled non-equilibrium model for inductively coupled radio-frequency plasmas
Munafò, A.; Alfuhaid, S. A.; Cambier, J.-L.; Panesi, M.
2015-10-01
The objective of the present work is the development of a tightly coupled magneto-hydrodynamic model for inductively coupled radio-frequency plasmas. Non Local Thermodynamic Equilibrium (NLTE) effects are described based on a hybrid State-to-State approach. A multi-temperature formulation is used to account for thermal non-equilibrium between translation of heavy-particles and vibration of molecules. Excited electronic states of atoms are instead treated as separate pseudo-species, allowing for non-Boltzmann distributions of their populations. Free-electrons are assumed Maxwellian at their own temperature. The governing equations for the electro-magnetic field and the gas properties (e.g., chemical composition and temperatures) are written as a coupled system of time-dependent conservation laws. Steady-state solutions are obtained by means of an implicit Finite Volume method. The results obtained in both LTE and NLTE conditions over a broad spectrum of operating conditions demonstrate the robustness of the proposed coupled numerical method. The analysis of chemical composition and temperature distributions along the torch radius shows that: (i) the use of the LTE assumption may lead to an inaccurate prediction of the thermo-chemical state of the gas, and (ii) non-equilibrium phenomena play a significant role close the walls, due to the combined effects of Ohmic heating and macroscopic gradients.
11. A tightly coupled non-equilibrium model for inductively coupled radio-frequency plasmas
SciTech Connect
Munafò, A. Alfuhaid, S. A. Panesi, M.; Cambier, J.-L.
2015-10-07
The objective of the present work is the development of a tightly coupled magneto-hydrodynamic model for inductively coupled radio-frequency plasmas. Non Local Thermodynamic Equilibrium (NLTE) effects are described based on a hybrid State-to-State approach. A multi-temperature formulation is used to account for thermal non-equilibrium between translation of heavy-particles and vibration of molecules. Excited electronic states of atoms are instead treated as separate pseudo-species, allowing for non-Boltzmann distributions of their populations. Free-electrons are assumed Maxwellian at their own temperature. The governing equations for the electro-magnetic field and the gas properties (e.g., chemical composition and temperatures) are written as a coupled system of time-dependent conservation laws. Steady-state solutions are obtained by means of an implicit Finite Volume method. The results obtained in both LTE and NLTE conditions over a broad spectrum of operating conditions demonstrate the robustness of the proposed coupled numerical method. The analysis of chemical composition and temperature distributions along the torch radius shows that: (i) the use of the LTE assumption may lead to an inaccurate prediction of the thermo-chemical state of the gas, and (ii) non-equilibrium phenomena play a significant role close the walls, due to the combined effects of Ohmic heating and macroscopic gradients.
12. NON-EQUILIBRIUM THERMODYNAMIC PROCESSES: SPACE PLASMAS AND THE INNER HELIOSHEATH
SciTech Connect
2012-04-10
Recently, empirical kappa distribution, commonly used to describe non-equilibrium systems like space plasmas, has been connected with non-extensive statistical mechanics. Here we show how a consistent definition of the temperature and pressure is developed for stationary states out of thermal equilibrium, so that the familiar ideal gas state equation still holds. In addition to the classical triplet of temperature, pressure, and density, this generalization requires the kappa index as a fourth independent thermodynamic variable that characterizes the non-equilibrium stationary states. All four of these thermodynamic variables have key roles in describing the governing thermodynamical processes and transitions in space plasmas. We introduce a novel characterization of isothermal and isobaric processes that describe a system's transition into different stationary states by varying the kappa index. In addition, we show how the variation of temperature or/and pressure can occur through an 'iso-q' process, in which the system remains in a fixed stationary state (fixed kappa index). These processes have been detected in the proton plasma in the inner heliosheath via specialized data analysis of energetic neutral atom (ENA) observations from Interstellar Boundary Explorer. In particular, we find that the temperature is highly correlated with (1) kappa, asymptotically related to isothermal ({approx}1,000,000 K) and iso-q ({kappa} {approx} 1.7) processes; and (2) density, related to an isobaric process, which separates the 'Ribbon', P Almost-Equal-To 3.2 pdyn cm{sup -2}, from the globally distributed ENA flux, P Almost-Equal-To 2 pdyn cm{sup -2}.
13. Inactivation Process of Penicillium digitatum Spores Treated with Non-equilibrium Atmospheric Pressure Plasma
Hashizume, Hiroshi; Ohta, Takayuki; Mori, Takumi; Iseki, Sachiko; Hori, Masaru; Ito, Masafumi
2013-05-01
To investigate the inactivation process of Penicillium digitatum spores treated with a non-equilibrium atmospheric pressure plasma, the spores were observed using a fluorescent microscope and compared with those treated with ultraviolet (UV) light or moist heat. The treated spores were stained with two fluorescent dyes, 1,1'-dioctadecyl-3,3,Y,3'-tetramethylindocarbocyanine perchlorate (DiI) and diphenyl-1-pyrenylphosphine (DPPP). The intracellular organelles as well as cell membranes in the spores treated with the plasma were stained with DiI without a major morphological change of the membranes, while the organelles were never stained in the spores treated with UV light or moist heat. Moreover, DPPP staining revealed that organelles were oxidized by plasma treatment unlike UV light or moist heat treatments. These results suggest that only plasma treatment induces a minor structural change or functional inhibition of cell membranes, which leads to the oxidation of the intracellular organelles without a major deformation of the membranes through the penetration of reactive oxygen species generated by the plasma into the cell.
14. Influence of Penning effect on the plasma features in a non-equilibrium atmospheric pressure plasma jet
SciTech Connect
Chang, Zhengshi; Zhang, Guanjun; Jiang, Nan; Cao, Zexian
2014-03-14
Non-equilibrium atmospheric pressure plasma jet (APPJ) is a cold plasma source that promises various innovative applications. The influence of Penning effect on the formation, propagation, and other physical properties of the plasma bullets in APPJ remains a debatable topic. By using a 10 cm wide active electrode and a frequency of applied voltage down to 0.5 Hz, the Penning effect caused by preceding discharges can be excluded. It was found that the Penning effect originating in a preceding discharge helps build a conductive channel in the gas flow and provide seed electrons, thus the discharge can be maintained at a low voltage which in turn leads to a smaller propagation speed for the plasma bullet. Photographs from an intensified charge coupled device reveal that the annular structure of the plasma plume for He is irrelevant to the Penning ionization process arising from preceding discharges. By adding NH{sub 3} into Ar to introduce Penning effect, the originally filamentous discharge of Ar can display a rather extensive plasma plume in ambient as He. These results are helpful for the understanding of the behaviors of non-equilibrium APPJs generated under distinct conditions and for the design of plasma jet features, especially the spatial distribution and propagation speed, which are essential for application.
15. The stationary non-equilibrium plasma of cosmic-ray electrons and positrons
Tomaschitz, Roman
2016-06-01
The statistical properties of the two-component plasma of cosmic-ray electrons and positrons measured by the AMS-02 experiment on the International Space Station and the HESS array of imaging atmospheric Cherenkov telescopes are analyzed. Stationary non-equilibrium distributions defining the relativistic electron-positron plasma are derived semi-empirically by performing spectral fits to the flux data and reconstructing the spectral number densities of the electronic and positronic components in phase space. These distributions are relativistic power-law densities with exponential cutoff, admitting an extensive entropy variable and converging to the Maxwell-Boltzmann or Fermi-Dirac distributions in the non-relativistic limit. Cosmic-ray electrons and positrons constitute a classical (low-density high-temperature) plasma due to the low fugacity in the quantized partition function. The positron fraction is assembled from the flux densities inferred from least-squares fits to the electron and positron spectra and is subjected to test by comparing with the AMS-02 flux ratio measured in the GeV interval. The calculated positron fraction extends to TeV energies, predicting a broad spectral peak at about 1 TeV followed by exponential decay.
16. Flow reactor studies of non-equilibrium plasma-assisted oxidation of n-alkanes.
PubMed
Tsolas, Nicholas; Lee, Jong Guen; Yetter, Richard A
2015-08-13
The oxidation of n-alkanes (C1-C7) has been studied with and without the effects of a nanosecond, non-equilibrium plasma discharge at 1 atm pressure from 420 to 1250 K. Experiments have been performed under nearly isothermal conditions in a flow reactor, where reactive mixtures are diluted in Ar to minimize temperature changes from chemical reactions. Sample extraction performed at the exit of the reactor captures product and intermediate species and stores them in a multi-position valve for subsequent identification and quantification using gas chromatography. By fixing the flow rate in the reactor and varying the temperature, reactivity maps for the oxidation of fuels are achieved. Considering all the fuels studied, fuel consumption under the effects of the plasma is shown to have been enhanced significantly, particularly for the low-temperature regime (T<800 K). In fact, multiple transitions in the rates of fuel consumption are observed depending on fuel with the emergence of a negative-temperature-coefficient regime. For all fuels, the temperature for the transition into the high-temperature chemistry is lowered as a consequence of the plasma being able to increase the rate of fuel consumption. Using a phenomenological interpretation of the intermediate species formed, it can be shown that the active particles produced from the plasma enhance alkyl radical formation at all temperatures and enable low-temperature chain branching for fuels C3 and greater. The significance of this result demonstrates that the plasma provides an opportunity for low-temperature chain branching to occur at reduced pressures, which is typically observed at elevated pressures in thermal induced systems. PMID:26170423
17. Flow reactor studies of non-equilibrium plasma-assisted oxidation of n-alkanes.
PubMed
Tsolas, Nicholas; Lee, Jong Guen; Yetter, Richard A
2015-08-13
The oxidation of n-alkanes (C1-C7) has been studied with and without the effects of a nanosecond, non-equilibrium plasma discharge at 1 atm pressure from 420 to 1250 K. Experiments have been performed under nearly isothermal conditions in a flow reactor, where reactive mixtures are diluted in Ar to minimize temperature changes from chemical reactions. Sample extraction performed at the exit of the reactor captures product and intermediate species and stores them in a multi-position valve for subsequent identification and quantification using gas chromatography. By fixing the flow rate in the reactor and varying the temperature, reactivity maps for the oxidation of fuels are achieved. Considering all the fuels studied, fuel consumption under the effects of the plasma is shown to have been enhanced significantly, particularly for the low-temperature regime (T<800 K). In fact, multiple transitions in the rates of fuel consumption are observed depending on fuel with the emergence of a negative-temperature-coefficient regime. For all fuels, the temperature for the transition into the high-temperature chemistry is lowered as a consequence of the plasma being able to increase the rate of fuel consumption. Using a phenomenological interpretation of the intermediate species formed, it can be shown that the active particles produced from the plasma enhance alkyl radical formation at all temperatures and enable low-temperature chain branching for fuels C3 and greater. The significance of this result demonstrates that the plasma provides an opportunity for low-temperature chain branching to occur at reduced pressures, which is typically observed at elevated pressures in thermal induced systems.
18. Application Of Highly Non-Equilibrium Plasma For Modification Of Biomedical Samples
Mozetic, M.
2010-07-01
Non-equilibrium processing of organic materials enables modification of surface properties without changing bulk characteristics of materials. Heavily nonequilibrium state of gas is obtained in a variety of discharges, but electrode-less high frequency discharges are particularly useful. Such discharges often provide plasma with a low ionization fraction (often below 10^-5), but the dissociation fraction is often close to 100%. Neutral atoms readily react with organic materials even at room temperature. Depending on the type of organic material, both surface morphology and functionality are modified. The technique is particularly suitable for improvement of biocompatibility as well as for controlled degradation of biological cells. Several examples on the functionalization of polymer materials will be presented. Furthermore, extremely high etching selectivity of neutral oxygen atoms allows for modification of the surface roughness which, in combination with extremely high density of polar surface functional groups leads to super-hydrophilic character of some polymers. An interesting application of such technology is for modification of the surface properties of vascular grafts. Plasma treated artificial blood vessels exhibit excellent anti-thrombogenic properties as well as good ability for growing of endothelial cells. The same technique is applied for selective removal of some organic materials from biological cells. Proper treatment allows for revealing the internal structure of biological cells. Examples of treatment of different bacteria are presented.
19. Radicals and Non-Equilibrium Processes in Low-Temperature Plasmas
2007-06-01
Serbian Academy of Sciences and Arts and Institute of Physics, Belgrade. Each Symposium has sought to highlight a key topic of plasma research and the 5th EU - Japan symposium explored the role of Radicals and Non-Equilibrium Processes in Low-Temperature Plasmas since these are key elements of plasma processing. Other aspects of technologies for manufacturing integrated circuits were also considered. Unlike bio-medicine and perhaps politics, in plasma processing free radicals are good radicals' but their kinetics are difficult to understand since there remains little data on their collisions with electrons and ions. One of the goals of the symposium was to facilitate communication between experimentalists and theorists in binary collision physics with plasma modellers and practitioners of plasma processing in order to optimize efforts to provide much needed data for both molecules and radicals of practical importance. The non-equilibrium nature of plasmas is critical in the efficient manufacturing of high resolution structures by anisotropic plasma etching on Si wafers since they allow separate control of the directionality and energy of ions and provide a high level of separation between the mean energies of electrons and ions. As nanotechnologies become practical, plasma processing may play a key role, not only in manufacturing of integrated circuits, but also for self-organization of massively parallel manufacturing of nanostructures. In this Symposium the key issues that are hindering the development of such new, higher resolution technologies were discussed and some possible solutions were proposed. In particular, damage control, fast neutral etching, processes at surface and modeling of profiles were addressed in several of the lectures. A wide range of topics are covered in this book including atomic and molecular collision physics - primarily focused towards formation and analysis of radicals, basic swarm data and breakdown kinetics, basic kinetics of RF and DC
20. Radicals and Non-Equilibrium Processes in Low-Temperature Plasmas
2007-06-01
Serbian Academy of Sciences and Arts and Institute of Physics, Belgrade. Each Symposium has sought to highlight a key topic of plasma research and the 5th EU - Japan symposium explored the role of Radicals and Non-Equilibrium Processes in Low-Temperature Plasmas since these are key elements of plasma processing. Other aspects of technologies for manufacturing integrated circuits were also considered. Unlike bio-medicine and perhaps politics, in plasma processing free radicals are good radicals' but their kinetics are difficult to understand since there remains little data on their collisions with electrons and ions. One of the goals of the symposium was to facilitate communication between experimentalists and theorists in binary collision physics with plasma modellers and practitioners of plasma processing in order to optimize efforts to provide much needed data for both molecules and radicals of practical importance. The non-equilibrium nature of plasmas is critical in the efficient manufacturing of high resolution structures by anisotropic plasma etching on Si wafers since they allow separate control of the directionality and energy of ions and provide a high level of separation between the mean energies of electrons and ions. As nanotechnologies become practical, plasma processing may play a key role, not only in manufacturing of integrated circuits, but also for self-organization of massively parallel manufacturing of nanostructures. In this Symposium the key issues that are hindering the development of such new, higher resolution technologies were discussed and some possible solutions were proposed. In particular, damage control, fast neutral etching, processes at surface and modeling of profiles were addressed in several of the lectures. A wide range of topics are covered in this book including atomic and molecular collision physics - primarily focused towards formation and analysis of radicals, basic swarm data and breakdown kinetics, basic kinetics of RF and DC
1. Practical and theoretical considerations on the use of ICCD imaging for the characterization of non-equilibrium plasmas
Gherardi, Matteo; Puač, Nevena; Marić, Dragana; Stancampiano, Augusto; Malović, Gordana; Colombo, Vittorio; Petrović, Zoran Lj
2015-12-01
Over the past decade the use of ICCD cameras as a means for characterizing non-equilibrium plasmas has been steadily increasing. Due to their high sensitivity and high speed gateability, ICCD cameras enable time-resolved studies of the anatomy and, when adopted in conjunction with filters, monochromators, spectrometers or laser systems, time-resolved investigation of physical and chemical properties of non-equilibrium plasma discharges. This paper is meant as an introduction to ICCD technology and its use as a plasma diagnostic technique, discussing the experimental problems typically associated with its use and providing the readers with practical examples and suggestions on how to address them. In particular, the issues of ICCD camera synchronization with the voltage pulse driving the plasma discharge and of investigating small volume discharges are addressed, focusing mainly on the case of non-equilibrium atmospheric pressure plasma jets. Finally, a possible way to achieve absolute calibration of plasma discharge emission is presented and discussed. A wide range of data, mostly unpublished, is provided here to illustrate the points.
2. Laboratory studies of kinetic instabilities under double plasma resonance condition in a mirror-confined non-equilibrium plasma
Viktorov, Mikhail; Golubev, Sergey; Mansfeld, Dmitry; Vodopyanov, Alexander; Zaitsev, Valery
2016-04-01
Plasma instabilities in magnetic traps on the Sun are the sources of powerful broadband radio emission (the so-called type IV bursts) which is interpreted as the excitation of plasma waves by fast electrons in the upper hybrid resonance frequency followed by transformation in electromagnetic waves. In the case of double plasma resonance condition when the frequency of the upper hybrid resonance coincides with one of the electron gyrofrequency harmonics the instability increment of plasma waves is greatly increased. This leads to the appearance of bright narrow-band radio emission near the harmonics of the electron gyrofrequency - the so-called zebra patterns. With the use of non-equilibrium mirror-confined plasma produced by the electron cyclotron resonance (ECR) discharge we provide the possibility to study plasma instabilities under double plasma resonance condition in the laboratory. In the experiment such conditions are fulfilled just after ECR heating switch-off, i.e. in the very beginning of a dense plasma decay phase. The observed instability is accompanied by a pulse-periodic generation of a powerful electromagnetic radiation at a frequency close to the upper hybrid resonance frequency and a second harmonic of the electron gyrofrequency, and synchronous precipitations of fast electrons from the trap ends. It is shown that the observed instability is due to the excitation of plasma waves at a double plasma resonance in decaying plasma of the ECR discharge. Possible manifestations of double plasma resonance effect are not rare in astrophysical plasmas. The phenomenon of zebra pattern is observed not only on the Sun, but in the decametric radiation of the Jupiter, kilometric radiation of the Earth and even in the radio emissions of pulsars. Thus, verification of the effect of double plasma resonance in a laboratory plasma experiments is a very relevant task.
3. Dynamical properties of non-equilibrium atmospheric plasma jets and their applications to plasma processing in liquids
Kitano, Katsuhisa; Satoshi, Ikawa; Furusho, Hitoshi; Nagasaki, Yukio; Hamaguchi, Satoshi
2007-11-01
Non-equilibrium atmospheric pressure plasma jets are discussed with the emphasis on their physics and applications. Plume-like plasmas, which may be called plasma jets, have been generated in a discharge system consisting of a dielectric/metal tube (through which He gas flows at the atmospheric pressure) and a single electrode attached to the tube, to which low-frequency, high-voltage pulses (˜10kV, ˜10kHz) are applied. With visible light images taken by a high-speed ICCD camera, it has been confirmed that the plasma jet consists of a series of small plasma bullets'' that are emitted intermittently from the powered electrode in sync with the positive voltage pulses. The observed plasma bullet'' may be interpreted as a fast moving ionization front. The plasma jets are energetic enough to generate highly reactive charge-neutral radicals but their gas temperatures remain low. Therefore the plasma jets are ideal for processing of liquid based materials at low temperatures and some examples of process applications, such as reduction of cations, polymerization of liquid monomers, and sterilization, will be also presented.
4. Study of a non-equilibrium plasma pinch with application for microwave generation
The Non-Equilibrium Plasma Pinch (NEPP), also known as the Dense Plasma Focus (DPF) is well known as a source of energetic ions, relativistic electrons and neutrons as well as electromagnetic radiation extending from the infrared to X-ray. In this dissertation, the operation of a 15 kJ, Mather type, NEPP machine is studied in detail. A large number of experiments are carried out to tune the machine parameters for best performance using helium and hydrogen as filling gases. The NEPP machine is modified to be able to extract the copious number of electrons generated at the pinch. A hollow anode with small hole at the flat end, and a mock magnetron without biasing magnetic field are built. The electrons generated at the pinch are very difficult to capture, therefore a novel device is built to capture and transport the electrons from the pinch to the magnetron. The novel cup-rod-needle device successfully serves the purpose to capture and transport electrons to monitor the pinch current. Further, the device has the potential to field emit charges from its needle end acting as a pulsed electron source for other devices such as the magnetron. Diagnostics tools are designed, modeled, built, calibrated, and implemented in the machine to measure the pinch dynamics. A novel, UNLV patented electromagnetic dot sensors are successfully calibrated, and implemented in the machine. A new calibration technique is developed and test stands designed and built to measure the dot's ability to track the impetus signal over its dynamic range starting and ending in the noise region. The patented EM-dot sensor shows superior performance over traditional electromagnetic sensors, such as Rogowski coils. On the other hand, the cup-rod structure, when grounded on the rod side, serves as a diagnostic tool to monitor the pinch current by sampling the actual current, a quantity that has been always very challenging to measure without perturbing the pinch. To the best of our knowledge, this method
5. Non-equilibrium modeling of UV laser induced plasma on a copper target in the presence of Cu2+
Ait Oumeziane, Amina; Liani, Bachir; Parisse, Jean-Denis
2016-03-01
This work is a contribution to the understanding of UV laser ablation of a copper sample in the presence of Cu2+ species as well as electronic non-equilibrium in the laser induced plasma. This particular study extends a previous paper and develops a 1D hydrodynamic model to describe the behavior of the laser induced plume, including the thermal non-equilibrium between electrons and heavy particles. Incorporating the formation of doubly charged ions (Cu2+) in such an approach has not been considered previously. We evaluate the effect of the presence of doubly ionized species on the characteristics of the plume, i.e., temperature, pressure, and expansion velocity, and on the material itself by evaluating the ablation depth and plasma shielding effects. This study evaluates the effects of the doubly charged species using a non-equilibrium hydrodynamic approach which comprises a contribution to the understanding of the governing processes of the interaction of ultraviolet nanosecond laser pulses with metals and the parameter optimization depending on the intended application.
6. Non-Equilibrium Plasma Applications for Water Purification Supporting Human Spaceflight and Terrestrial Point-of-Use
NASA Technical Reports Server (NTRS)
Blankson, Isaiah M.; Foster, John E.; Adamovsky, Grigory
2016-01-01
2016 NASA Glenn Technology Day Panel Presentation on May 24, 2016. The panel description is: Environmental Impact: NASA Glenn Water Capabilities Both global water scarcity and water treatment concerns are two of the most predominant environmental issues of our time. Glenn researchers share insights on a snow sensing technique, hyper spectral imaging of Lake Erie algal blooms, and a discussion on non-equilibrium plasma applications for water purification supporting human spaceflight and terrestrial point-of-use. The panel moderator will be Bryan Stubbs, Executive Director of the Cleveland Water Alliance.
7. Synthesis of calcium oxalate crystals in culture medium irradiated with non-equilibrium atmospheric-pressure plasma
Kurake, Naoyuki; Tanaka, Hiromasa; Ishikawa, Kenji; Nakamura, Kae; Kajiyama, Hiroaki; Kikkawa, Fumitaka; Mizuno, Masaaki; Yamanishi, Yoko; Hori, Masaru
2016-09-01
Octahedral particulates several tens of microns in size were synthesized in a culture medium irradiated through contact with a plume of non-equilibrium atmospheric-pressure plasma (NEAPP). The particulates were identified in the crystalline phase as calcium oxalate dihydrate (COD). The original medium contained constituents such as NaCl, d-glucose, CaCl2, and NaHCO3 but not oxalate or oxalic acid. The oxalate was clearly synthesized and crystallized in the medium as thermodynamically unstable COD crystals after the NEAPP irradiation.
8. Non-Equilibrium Magnetohydrodynamic Behavior of Plasmas having Complex, Evolving Morphology
SciTech Connect
Bellan, Paul M.
2014-03-13
Our main activity has been doing lab experiments where plasmas having morphology and behavior similar to solar and astrophysical plasmas are produced and studied. The solar experiment is mounted on one end of a large vacuum chamber while the astrophysical jet experiment is mounted on the other end. Diagnostics are shared between the two experiments. The solar experiment produces arched plasma loops that behave very much like solar corona loops. The astrophysical jet experiment produces plasma jets that are very much like astrophysical jets. We have also done work on plasma waves, including general wave dispersions, and specific properties of kinetic Alfven waves and of whistler waves.
9. Non-equilibrium magnetic colloidal dispersions at liquid-air interfaces: dynamic patterns, magnetic order and self-assembled swimmers.
PubMed
Snezhko, Alexey
2011-04-20
Colloidal dispersions of interacting particles subjected to an external periodic forcing often develop nontrivial self-assembled patterns and complex collective behavior. A fundamental issue is how collective ordering in such non-equilibrium systems arises from the dynamics of discrete interacting components. In addition, from a practical viewpoint, by working in regimes far from equilibrium new self-organized structures which are generally not available through equilibrium thermodynamics can be created. In this review spontaneous self-assembly phenomena in magnetic colloidal dispersions suspended at liquid-air interfaces and driven out of equilibrium by an alternating magnetic field are presented. Experiments reveal a new type of nontrivially ordered self-assembled structures emerging in such systems in a certain range of excitation parameters. These dynamic structures emerge as a result of the competition between magnetic and hydrodynamic forces and have complex unconventional magnetic ordering. Nontrivial self-induced hydrodynamic fields accompany each out-of-equilibrium pattern. Spontaneous symmetry breaking of the self-induced surface flows leading to a formation of self-propelled microstructures has been discovered. Some features of the self-localized structures can be understood in the framework of the amplitude equation (Ginzburg-Landau type equation) for parametric waves coupled to the conservation law equation describing the evolution of the magnetic particle density and the Navier-Stokes equation for hydrodynamic flows. To understand the fundamental microscopic mechanisms governing self-assembly processes in magnetic colloidal dispersions at liquid-air interfaces a first-principle model for a non-equilibrium self-assembly is presented. The latter model allows us to capture in detail the entire process of out-of-equilibrium self-assembly in the system and reproduces most of the observed phenomenology.
10. Thomson scattering on non-equilibrium low density plasmas: principles, practice and challenges
Carbone, Emile; Nijdam, Sander
2015-01-01
In this paper, we review the main challenges related to laser Thomson scattering on low temperature plasmas. The main features of the triple grating spectrometer used to discriminate Thomson and Raman scattering signals from Rayleigh scattering and stray light are presented. The main parameters influencing the detection limit of Thomson scattering are reviewed. Laser stray light and plasma emission are two limiting factors, but Raman scattering from molecules inside the plasma will further decrease it. In the case of non-thermal plasmas at high pressure, Thomson scattering is the only technique which allows us to obtain the electron density without any prior knowledge of the plasma properties. Moreover, very high 3D spatial and temporal resolutions can easily be achieved. However, special care still needs to be taken to verify that Thomson scattering is non intrusive. The mechanisms that will lead to possible measurement errors are discussed. The wavelength-resolved scattering signal also allows us to get direct information about the electron energy distribution function in the case of incoherent light scattering. Finally, we discuss some recent applications of Thomson scattering on atmospheric pressure plasma jets, but also in the field of electron collision kinetics. Thomson scattering can be applied on atomic but also molecular plasmas. In the latter case, one needs to take into account the possible contribution of rotational Raman scattering.
11. New approach for sustaining energetic, efficient and scalable non-equilibrium plasma in water vapours at atmospheric pressure
Arif Malik, Muhammad; Schoenbach, Karl H.
2012-04-01
Energetic and scalable non-equilibrium plasma was formed in pure water vapour at atmospheric pressure between wire-to-strip electrodes on a dielectric surface with one of the electrodes extended forming a conductive plane on the back side of the dielectric surface. The energy deposition increased by an order of magnitude compared with the conventional pulsed corona discharges under the same conditions. The scalability was demonstrated by operating two electrode assemblies with a common conductive plane between two dielectric layers. The energy yields for hydrogen and hydrogen peroxide generation were measured as ˜1.2 g H2/kWh and ˜4 g H2O2/kWh.
12. Air-sea interaction and surface flux in non-equilibrium sea-states
SciTech Connect
Levy, G.; Ek, M.; Mahrt, L.
1994-12-31
The wind forcing over the ocean determines the air-sea exchanges of heat, moisture and momentum which affect and drive the surface wave dynamics and the mixed layer circulation. In turn, it has been shown that wave dynamics and wave age affect ocean surface roughness and air-sea exchange processes so that the wind flow is not always in equilibrium with the ocean surface waves. This effect of wave spectrum on surface roughness has been discussed by many authors; yet it is rarely, if ever, accounted for in flux parameterization in models of the marine atmospheric boundary layer (MABL). Proper representation of these effects in both remote sensors signal to geophysical-parameter models and in physical models of the ocean and the atmosphere on all scales is essential given the increased reliance of ocean monitoring systems on remote sea-surface sensors and the fundamental sensitivity of physical models to surface fluxes. In this paper the authors present a methodology for modeling these effects from data along with some results from data analyses of observations taken in two field experiments.
13. Thermo-chemical dynamics and chemical quasi-equilibrium of plasmas in thermal non-equilibrium
SciTech Connect
Massot, Marc; Graille, Benjamin; Magin, Thierry E.
2011-05-20
We examine both processes of ionization by electron and heavy-particle impact in spatially uniform plasmas at rest in the absence of external forces. A singular perturbation analysis is used to study the following physical scenario, in which thermal relaxation becomes much slower than chemical reactions. First, electron-impact ionization is investigated. The dynamics of the system rapidly becomes close to a slow dynamics manifold that allows for defining a unique chemical quasi-equilibrium for two-temperature plasmas and proving that the second law of thermodynamics is satisfied. Then, all ionization reactions are taken into account simultaneously, leading to a surprising conclusion: the inner layer for short time scale (or time boundary layer) directly leads to thermal equilibrium. Global thermo-chemical equilibrium is reached within a short time scale, involving only chemical reactions, even if thermal relaxation through elastic collisions is assumed to be slow.
14. Non-equilibrium radiation during SiC-CO2 plasma interaction
Brémare, Noémie; Jouen, Samuel; Boubert, Pascal
2016-04-01
The radiation of a pure CO2 inductive plasma was recorded between 190 and 920 nm during its interaction with a SiC sample under a pressure equal to 6 kPa and an estimated global specific enthalpy close to 12 MJ kg-1. The plasma electronic excitation was found to be out of equilibrium. The main radiators were found to be O, C, C2 and, mainly, CO. The radiation is especially significant where the plasma chemically interacts with the material revealing a stronger electronic excitation close to the surface. Excitation temperatures were also found to increase in the chemical boundary layer, which is four times smaller than the thermal boundary layer. This raises questions about the energy exchange processes of the excited states and about chemical behaviour independent of their respective ground states. The surface is found to be covered by an inhomogeneous silica layer revealing a passive oxidation, but also by bubble structures, indicative of the transition towards active oxidation. The surface temperature is estimated to be 1800-1900 K. Raman spectroscopy measurements on the surface and optical spectroscopy measurements in the boundary layer provide proof of carbon production coming from the SiC.
15. Computation of non-equilibrium flow downstream of a plasma torch
NASA Technical Reports Server (NTRS)
Harle, Christophe; Varghese, Philip L.; Carey, Graham F.
1992-01-01
Numerical solutions of the Navier-Stokes equations for compressible reacting flow in an axisymmetric geometry are presented for a nitrogen plasma torch with both thermal and chemical nonequilibrium. The Navier-Stokes equations are solved using a new axisymmetric finite element/finite volume formulation in which the convective flux is treated by an extension of the approximate Riemann solver due to Osher. The numerical scheme is validated by comparison with a previous solution of the same problem using a different computational scheme. Results obtained using two different models of nonthermal dissociation rates are compared to experimental data.
16. Thermophysical properties of nitrogen plasmas under thermal equilibrium and non-equilibrium conditions
SciTech Connect
Wang Weizong; Rong Mingzhe; Yan, J. D.; Spencer, Joseph W.; Murphy, A. B.
2011-11-15
Calculated thermophysical properties of nitrogen plasmas in and out of thermal equilibrium are presented. The cut-off of the partition functions due to the lowering of the ionization potential has been taken into account, together with the contributions from different core excited electronic states. The species composition and thermodynamic properties are determined numerically using the Newton-Raphson iterative method, taking into account the corrections due to Coulomb interactions. The transport properties including diffusion coefficient, viscosity, thermal conductivity, and electrical conductivity are calculated using the most recent collision interaction potentials by adopting Devoto's electron and heavy particle decoupling approach, expanded to the third-order approximation (second-order for viscosity) in the framework of Chapman-Enskog method. Results are presented in the pressure range of 0.1 atm-10 atm and in electron temperature range from 300 to 40 000 K, with the ratio of electron temperature to heavy-particle temperature varied from 1 to 20. Results are compared with those from previous works, and the influences of different definitions of the Debye length are discussed.
17. Electric Field Measurements in Non-Equilibrium Electric Discharge Plasmas Using Picosecond Four-Wave Mixing
Goldberg, Benjamin M.
This dissertation presents the results of development of a picosecond four wave mixing technique and its use for electric field measurements in nanosecond pulse discharges. This technique is similar to coherent anti-Stokes Raman spectroscopy and is well suited for electric field measurements in high pressure plasmas with high spatial and temporal resolution. The results show that the signal intensity scales proportionally to the square of the electric field, the signal is emitted as a coherent beam, and is polarized parallel to the electric field vector, making possible electric field vector component measurements. The signal is generated when a collinear pair of pump and Stokes beams, which are generated in a stimulated Raman shifting cell (SRS), generate coherent excitation of molecules into a higher energy level, hydrogen for the present work. The coherent excitation mixes with a dipole moment induced by an external electric field. The mixing of these three "waves'" allows the molecules to radiate at their Raman frequency, producing a fourth, signal, wave which is proportional to the square of the electric field. The time resolution of this technique is limited by the coherence decay time of the molecules, which is a few hundred picoseconds.
18. Direct exposure of non-equilibrium atmospheric pressure plasma confers simultaneous oxidative and ultraviolet modifications in biomolecules
PubMed Central
Okazaki, Yasumasa; Wang, Yue; Tanaka, Hiromasa; Mizuno, Masaaki; Nakamura, Kae; Kajiyama, Hiroaki; Kano, Hiroyuki; Uchida, Koji; Kikkawa, Fumitaka; Hori, Masaru; Toyokuni, Shinya
2014-01-01
Thermal plasmas and lasers are used in medicine to cut and ablate tissues and for coagulation. Non-equilibrium atmospheric pressure plasma (NEAPP) is a recently developed, non-thermal technique with possible biomedical applications. Although NEAPP reportedly generates reactive oxygen/nitrogen species, electrons, positive ions, and ultraviolet radiation, little research has been done into the use of this technique for conventional free radical biology. Recently, we developed a NEAPP device with high electron density. Electron spin resonance spin-trapping revealed •OH as a major product. To obtain evidence of NEAPP-induced oxidative modifications in biomolecules and standardize them, we evaluated lipid peroxidation and DNA modifications in various in vitro and ex vivo experiments. Conjugated dienes increased after exposure to linoleic and α-linolenic acids. An increase in 2-thiobarbituric acid-reactive substances was also observed after exposure to phosphatidylcholine, liposomes or liver homogenate. Direct exposure to rat liver in saline produced immunohistochemical evidence of 4-hydroxy-2-nonenal- and acrolein-modified proteins. Exposure to plasmid DNA induced dose-dependent single/double strand breaks and increased the amounts of 8-hydroxy-2'-deoxyguanosine and cyclobutane pyrimidine dimers. These results indicate that oxidative biomolecular damage by NEAPP is dose-dependent and thus can be controlled in a site-specific manner. Simultaneous oxidative and UV-specific DNA damage may be useful in cancer treatment. PMID:25411528
19. Enhanced nonlinear iterative techniques applied to a non-equilibrium plasma flow
SciTech Connect
Knoll, D.A.; McHugh, P.R.
1996-12-31
We study the application of enhanced nonlinear iterative methods to the steady-state solution of a system of two-dimensional convection-diffusion-reaction partial differential equations that describe the partially-ionized plasma flow in the boundary layer of a tokamak fusion reactor. This system of equations is characterized by multiple time and spatial scales, and contains highly anisotropic transport coefficients due to a strong imposed magnetic field. We use Newtons method to linearize the nonlinear system of equations resulting from an implicit, finite volume discretization of the governing partial differential equations, on a staggered Cartesian mesh. The resulting linear systems are neither symmetric nor positive definite, and are poorly conditioned. Preconditioned Krylov iterative techniques are employed to solve these linear systems. We investigate both a modified and a matrix-free Newton-Krylov implementation, with the goal of reducing CPU cost associated with the numerical formation of the Jacobian. A combination of a damped iteration, one-way multigrid and a pseudo-transient continuation technique are used to enhance global nonlinear convergence and CPU efficiency. GMRES is employed as the Krylov method with Incomplete Lower-Upper(ILU) factorization preconditioning. The goal is to construct a combination of nonlinear and linear iterative techniques for this complex physical problem that optimizes trade-offs between robustness, CPU time, memory requirements, and code complexity. It is shown that a one-way multigrid implementation provides significant CPU savings for fine grid calculations. Performance comparisons of the modified Newton-Krylov and matrix-free Newton-Krylov algorithms will be presented.
20. Antibody immobilization on poly(L-lactic acid) nanofibers advantageously carried out by means of a non-equilibrium atmospheric plasma process
Dolci, L. S.; Liguori, A.; Merlettini, A.; Calzà, L.; Castellucci, M.; Gherardi, M.; Colombo, V.; Focarete, M. L.
2016-07-01
In the present study, the comparison between a conventional wet-chemical method and a non-equilibrium atmospheric pressure plasma process for the conjugation of biomolecules on the surface of poly(L-lactic acid) (PLLA) electrospun fibers is reported. Physico-chemical and morphological characteristics of chemically and plasma functionalized mats are studied and compared with those of pristine mats. The efficiency in biomolecules immobilization is assessed by the covalent conjugation of an antibody (anti-CD10) on the functionalized PLLA fibers. The achieved results highlight that the proposed plasma process enables antibodies to be successfully immobilized on the surface of PLLA fibers, demonstrating that non-equilibrium atmospheric pressure plasma can be an effective, highly flexible and environmentally friendly alternative to the still widely employed wet-chemical methods for the conjugation of biomolecules onto biomaterials.
1. THE DIAGNOSTIC O VI ABSORPTION LINE IN DIFFUSE PLASMAS: COMPARISON OF NON-EQUILIBRIUM IONIZATION STRUCTURE SIMULATIONS TO FUSE DATA
SciTech Connect
De Avillez, Miguel A.; Breitschwerdt, Dieter
2012-12-20
The nature of the interstellar O VI in the Galactic disk is studied by means of a multi-fluid hydrodynamical approximation, tracing the detailed time-dependent evolution of the ionization structure of the plasma. Our focus is to explore the signature of any non-equilibrium ionization condition present in the interstellar medium using the diagnostic O VI ion. A detailed comparison between the simulations and FUSE data is carried out by taking lines of sight (LOS) measurements through the simulated Galactic disk, covering an extent of 4 kpc from different vantage points. The simulation results bear a striking resemblance with the observations: (1) the N(O VI) distribution with distance and angle fall within the minimum and maximum values of the FUSE data; (2) the column density dispersion with distance is constant for all the LOS, showing a mild decrease at large distances; (3) O VI has a clumpy distribution along the LOS; and (4) the time-averaged midplane density for distances >400 pc has a value of (1.3-1.4) Multiplication-Sign 10{sup -8} cm{sup -3}. The highest concentration of O VI by mass occurs in the thermally stable (10{sup 3.9} K < T {<=} 10{sup 4.2} K; 20%) and unstable (10{sup 4.2} K < T < 10{sup 5} K; 50%) regimes, both well below its peak temperature in collisional ionization equilibrium, with the corresponding volume filling factors oscillating with time between 8%-20% and 4%-5%, respectively. These results may also be relevant for intergalactic metal absorption systems at high redshifts.
2. Kinetics of plasma-assisted combustion: effect of non-equilibrium excitation on the ignition and oxidation of combustible mixtures
Popov, N. A.
2016-08-01
A review of experimental and theoretical investigations of the effect of atomic particles, and electronically and vibrationally excited molecules on the induction delay time and on the shift in the ignition temperature threshold of combustible mixtures is presented. The addition of oxygen and hydrogen atoms to combustible mixtures may cause a significant reduction in the ignition delay time. However, at relatively low initial temperatures, the non-equilibrium effect of the addition of atomic particles in ground electronic states is not pronounced. At the same time, the effect of excited O(1D) atoms on the oxidation and reforming of combustible mixtures is quite significant due to the high rates of reactions of O(1D) atoms with hydrogen and hydrocarbon molecules. In fuel–air mixtures, collisions with O(1D) atoms determine, under certain conditions, the dissociation of hydrocarbon molecules. Singlet oxygen molecules, O2(a1Δ g ), participate both in chain initiation and chain branching reactions, but the effect of O2(a1Δ g ) on the ignition processes is generally less important compared to oxygen atoms. The reactions of vibrationally excited molecules and the processes of VT-relaxation in combustible mixtures are discussed. The production of vibrationally excited N 2(v) molecules in fuel–air mixtures at relatively low electric field is very important. However, at the moment, the effect of the reactions of N 2(v) molecules on the oxidation and ignition of combustible mixtures is not completely clear, and requires further investigation. Therefore, with present knowledge, to reduce the ignition delay time and decrease the temperature threshold of combustive mixtures, the use of gas discharge systems with relatively high E/N values is recommended. In this case the reactions of electronically excited {{\\text{N}}2}≤ft(\\text{A}{}3Σu+,\\text{B}{}3{{\\Pi}g},\\text{C}{}3{{\\Pi}u},\\text{a}{}\\prime 1Σu-\\right) molecules, and atomic particles in ground and
3. Kinetics of plasma-assisted combustion: effect of non-equilibrium excitation on the ignition and oxidation of combustible mixtures
Popov, N. A.
2016-08-01
A review of experimental and theoretical investigations of the effect of atomic particles, and electronically and vibrationally excited molecules on the induction delay time and on the shift in the ignition temperature threshold of combustible mixtures is presented. The addition of oxygen and hydrogen atoms to combustible mixtures may cause a significant reduction in the ignition delay time. However, at relatively low initial temperatures, the non-equilibrium effect of the addition of atomic particles in ground electronic states is not pronounced. At the same time, the effect of excited O(1D) atoms on the oxidation and reforming of combustible mixtures is quite significant due to the high rates of reactions of O(1D) atoms with hydrogen and hydrocarbon molecules. In fuel-air mixtures, collisions with O(1D) atoms determine, under certain conditions, the dissociation of hydrocarbon molecules. Singlet oxygen molecules, O2(a1Δ g ), participate both in chain initiation and chain branching reactions, but the effect of O2(a1Δ g ) on the ignition processes is generally less important compared to oxygen atoms. The reactions of vibrationally excited molecules and the processes of VT-relaxation in combustible mixtures are discussed. The production of vibrationally excited N 2(v) molecules in fuel-air mixtures at relatively low electric field is very important. However, at the moment, the effect of the reactions of N 2(v) molecules on the oxidation and ignition of combustible mixtures is not completely clear, and requires further investigation. Therefore, with present knowledge, to reduce the ignition delay time and decrease the temperature threshold of combustive mixtures, the use of gas discharge systems with relatively high E/N values is recommended. In this case the reactions of electronically excited {{\\text{N}}2}≤ft(\\text{A}{}3Σu+,\\text{B}{}3{{\\Pi}g},\\text{C}{}3{{\\Pi}u},\\text{a}{}\\prime 1Σu-\\right) molecules, and atomic particles in ground and
4. Plasma treatment of carbon fibers: Non-equilibrium dynamic adsorption and its effect on the mechanical properties of RTM fabricated composites
Ma, Keming; Wang, Baichen; Chen, Ping; Zhou, Xia
2011-02-01
The effect of oxygen plasma treatment on the non-equilibrium dynamic adsorption of the carbon fabric reinforcements in RTM process was studied. 5-Dimethylamino-1-naphthalene-sulfonylchloride (DNS-Cl) was attached to the curing agent to study the change of curing agent content in the epoxy resin matrix. Steady state fluorescence spectroscopy (FS) analysis was used to study this changes in the epoxy resin at the inlet and outlet of the RTM mould, and XPS was used to study the chemical changes on the carbon fiber surfaces introduced by plasma treatment. The interlaminar shear strength (ILSS) and flexural strength were also measured to study the effects of this non-equilibrium dynamic adsorption progress on the mechanical properties of the end products. FS analysis shows that the curing agent adsorbed onto the fiber surface preferentially for untreated carbon fiber, the curing agent content in the resin matrix maintain unchanged after plasma treatment for 3 min and 5 min, but after oxygen plasma treatment for 7 min, the epoxy resin adsorbed onto the fiber surface preferentially. XPS analysis indicated that the oxygen plasma treatment successfully increased some polar functional groups concentration on the carbon fiber surfaces, this changes on the carbon fiber surfaces can change the adsorption ability of carbon fiber to the resin and curing agent. The mechanical properties of the composites were correlated to this results.
5. Stark broadening for diagnostics of the electron density in non-equilibrium plasma utilizing isotope hydrogen alpha lines
SciTech Connect
Yang, Lin; Tan, Xiaohua; Wan, Xiang; Chen, Lei; Jin, Dazhi; Qian, Muyang; Li, Gongping
2014-04-28
Two Stark broadening parameters including FWHM (full width at half maximum) and FWHA (full width at half area) of isotope hydrogen alpha lines are simultaneously introduced to determine the electron density of a pulsed vacuum arc jet. To estimate the gas temperature, the rotational temperature of the C{sub 2} Swan system is fit to 2500 ± 100 K. A modified Boltzmann-plot method with b{sub i}-factor is introduced to determine the modified electron temperature. The comparison between results of atomic and ionic lines indicates the jet is in partial local thermodynamic equilibrium and the electron temperature is close to 13 000 ± 400 K. Based on the computational results of Gig-Card calculation, a simple and precise interpolation algorithm for the discrete-points tables can be constructed to obtain the traditional n{sub e}-T{sub e} diagnostic maps of two Stark broadening parameters. The results from FWHA formula by the direct use of FWHM = FWHA and these from the diagnostic map are different. It can be attributed to the imprecise FWHA formula form and the deviation between FWHM and FWHA. The variation of the reduced mass pair due to the non-equilibrium effect contributes to the difference of the results derived from two hydrogen isotope alpha lines. Based on the Stark broadening analysis in this work, a corrected method is set up to determine n{sub e} of (1.10 ± 0.08) × 10{sup 21} m{sup −3}, the reference reduced mass μ{sub 0} pair of (3.30 ± 0.82 and 1.65 ± 0.41), and the ion kinetic temperature of 7900 ± 1800 K.
6. Reaction of carbon tetrachloride with methane in a non-equilibrium plasma at atmospheric pressure, and characterisation of the polymer thus formed.
PubMed
Gaikwad, Vaibhav; Kennedy, Eric; Mackie, John; Holdsworth, Clovia; Molloy, Scott; Kundu, Sazal; Stockenhuber, Michael; Dlugogorski, Bogdan
2014-09-15
In this paper we focus on the development of a methodology for treatment of carbon tetrachloride utilising a non-equilibrium plasma operating at atmospheric pressure, which is not singularly aimed at destroying carbon tetrachloride but rather at converting it to a non-hazardous, potentially valuable commodity. This method encompasses the reaction of carbon tetrachloride and methane, with argon as a carrier gas, in a quartz dielectric barrier discharge reactor. The reaction is performed under non-oxidative conditions. Possible pathways for formation of major products based on experimental results and supported by quantum chemical calculations are outlined in the paper. We elucidate important parameters such as carbon tetrachloride conversion, product distribution, mass balance and characterise the chlorinated polymer formed in the process.
7. Non-Equilibrium Vibrational Kinetics in Radiofrequency H2 Plasmas: a Comparison Between Theoretical and Experimental Results
SciTech Connect
Capitelli, M.; De Pascale, O.; Shakatov, V.; Hassouni, K.; Lombardi, G.; Gicquel, A.
2005-05-16
Vibrational and rotational experimental temperatures of molecular hydrogen obtained by Coherent Anti-Stokes Spectroscopy (CARS) in Radiofrequency Inductive Plasmas have been analyzed and interpreted in terms of vibration, electron, dissociation-recombination and attachment kinetics. The analysis clarifies the role of atomic hydrogen and its heterogeneous recombination in affecting the vibrational content of the molecules.
8. Evaluation of Penicillium digitatum sterilization using non-equilibrium atmospheric pressure plasma by terahertz time-domain spectroscopy
Hiraoka, Takehiro; Ebizuka, Noboru; Takeda, Keigo; Ohta, Takayuki; Kondo, Hiroki; Ishikawa, Kenji; Kawase, Kodo; Ito, Masafumi; Sekine, Makoto; Hori, Masaru
2011-10-01
Recently, the plasma sterilization has attracted much attention as a new sterilization technique that takes the place of spraying agricultural chemicals. The conventional methods for sterilization evaluation, was demanded to culture the samples for several days after plasma treatment. Then, we focused on Terahertz time-domain spectroscopy (THz-TDS). At the THz region, vibrational modes of biological molecules and fingerprint spectra of biologically-relevant molecules were also observed. In this study, our purpose was measurement of the fingerprint spectrum of the Penicillium digitatum (PD) spore and establishment of sterilization method by THz-TDS. The sample was 40mg/ml PD spore suspensions which dropped on cover glass. The atmospheric pressure plasma generated under the conditions which Ar gas flow was 3slm, and alternating voltage of 6kV was applied. The samples were exposed the plasma from 10mm distance for 10 minutes. We could obtain the fingerprint spectrum of the PD spore from 0.5 to 0.9THz. This result indicated the possibility of in-situ evaluation for PD sterilization using THz-TDS.
9. Non-equilibrium phase transitions
SciTech Connect
Mottola, E.; Cooper, F.M.; Bishop, A.R.; Habib, S.; Kluger, Y.; Jensen, N.G.
1998-12-31
This is the final report of a one-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). Non-equilibrium phase transitions play a central role in a very broad range of scientific areas, ranging from nuclear, particle, and astrophysics to condensed matter physics and the material and biological sciences. The aim of this project was to explore the path to a deeper and more fundamental understanding of the common physical principles underlying the complex real time dynamics of phase transitions. The main emphasis was on the development of general theoretical tools to deal with non-equilibrium processes, and of numerical methods robust enough to capture the time-evolving structures that occur in actual experimental situations. Specific applications to Laboratory multidivisional efforts in relativistic heavy-ion physics (transition to a new phase of nuclear matter consisting of a quark-gluon plasma) and layered high-temperature superconductors (critical currents and flux flow at the National High Magnetic Field Laboratory) were undertaken.
10. Si quantum dots embedded in an amorphous SiC matrix: nanophase control by non-equilibrium plasma hydrogenation.
PubMed
Cheng, Qijin; Tam, Eugene; Xu, Shuyan; Ostrikov, Kostya Ken
2010-04-01
Nanophase nc-Si/a-SiC films that contain Si quantum dots (QDs) embedded in an amorphous SiC matrix were deposited on single-crystal silicon substrates using inductively coupled plasma-assisted chemical vapor deposition from the reactive silane and methane precursor gases diluted with hydrogen at a substrate temperature of 200 degrees C. The effect of the hydrogen dilution ratio X (X is defined as the flow rate ratio of hydrogen-to-silane plus methane gases), ranging from 0 to 10.0, on the morphological, structural, and compositional properties of the deposited films, is extensively and systematically studied by scanning electron microscopy, high-resolution transmission electron microscopy, X-ray diffraction, Raman spectroscopy, Fourier-transform infrared absorption spectroscopy, and X-ray photoelectron spectroscopy. Effective nanophase segregation at a low hydrogen dilution ratio of 4.0 leads to the formation of highly uniform Si QDs embedded in the amorphous SiC matrix. It is also shown that with the increase of X, the crystallinity degree and the crystallite size increase while the carbon content and the growth rate decrease. The obtained experimental results are explained in terms of the effect of hydrogen dilution on the nucleation and growth processes of the Si QDs in the high-density plasmas. These results are highly relevant to the development of next-generation photovoltaic solar cells, light-emitting diodes, thin-film transistors, and other applications.
11. Synthesis of Vertically-Aligned Single-Walled Carbon Nanotubes in Micro Structure of Atmospheric Pressure Non-Equilibrium Plasma
Ohnishi, Kuma; Nozaki, Tomohiro; Okazaki, Ken; Heberlein, Joachim; Kortshagen, Uwe
Plasma enhanced chemical vapor deposition (PECVD) is recognized as one of the viable fabrication techniques of carbon nanotubes. The outstanding advantage of PECVD is that free-standing, vertically-aligned carbon nanotubes (VA-CNTs) are synthesized due to the electric field normal to the substrate. This feature draws intense attention for the fabrication of nanoelectronic devices such as high-resolution scanning nanoprobes, interconnects, and field emission devices. However, carbon nanotubes synthesized in PECVD are overwhelmingly carbon nanofibers (CNFs) or multi-walled carbon nanotubes (MWNTs) with measurable structural defects. Tremendous interest in the preparation and characterization of vertically-aligned single-walled carbon nanotubes (VA-SWNTs) and related applications had not been realized in the scope of PECVD until recently. Here we present a fabrication technique of high-purity vertically-aligned single-walled carbon nanotubes using atmospheric pressure plasma enhanced chemical vapor deposition. By now, we have developed the atmospheric pressure radio-frequency discharge (APRFD) for this purpose. Although densely mono-dispersed Fe-Co catalysts of a few nanometers is primarily responsible for VA-SWNT growth, carbon precipitation was virtually absent in the thermal CVD regime at 700°C. On the other hand, high-yield VA-SWNTs were grown at 4 μm min-1 by applying the atmospheric pressure radio-frequency discharge. The results proved that cathodic ion sheath adjacent to the substrates, where a large potential drop exists, also plays an essential role for the controlled growth of SWNTs, while ion damage to the VA-SWNTs is inherently avoided due to high collision frequency among molecules in atmospheric pressure. In this paper, operation regime of APRFD and tentative reaction mechanisms for VA-SWNT growth are discussed along with optical imaging of near substrate region of APRFD.
12. Numerical study on the spontaneous condensation flow in an air cryogenic turbo-expander using equilibrium and non-equilibrium models
Sun, Wan; Niu, Lu; Chen, Liang; Chen, Shuangtao; Zhang, Xingqun; Hou, Yu
2016-01-01
The difficulty of data measurement in cryogenic environments and the complicated mechanism of nucleation process have restricted the design of wet type turbo-expander for cryogenic liquid plants. In this paper, equilibrium and non-equilibrium models are used to model the spontaneous condensation flow in a cryogenic turbo-expander along the main stream passage including nozzle, impeller and diffuser. The comparison shows a distinct difference of the predicted wetness fraction distribution along the streamline between the equilibrium model and the non-equilibrium model. In non-equilibrium model, the distributions of supercooling and nucleation rate along the length of turbo-expander are given for the analysis of flow characteristics. The comparison of outlet wetness fraction with the experimental data is also provided for verification and discussion. Both the effects of the rotation on nucleation and the effects of the nucleation on flow along suction side of the impeller are investigated.
13. A numerical tool for the calculation of non-equilibrium ionisation states in the solar corona and other astrophysical plasma environments
2009-07-01
Context: The effects of non-equilibrium processes on the ionisation state of strongly emitting elements in the solar corona can be extremely difficult to assess and yet they are critically important. For example, there is much interest in dynamic heating events localised in the solar corona because they are believed to be responsible for its high temperature and yet recent work has shown that the hottest (≥107 K) emission predicted to be associated with these events can be observationally elusive due to the difficulty of creating the highly ionised states from which the expected emission arises. This leads to the possibility of observing instruments missing such heating events entirely. Aims: The equations describing the evolution of the ionisaton state are a very stiff system of coupled, partial differential equations whose solution can be numerically challenging and time-consuming. Without access to specialised codes and significant computational resources it is extremely difficult to avoid the assumption of an equilibrium ionisation state even when it clearly cannot be justified. The aim of the current work is to develop a computational tool to allow straightforward calculation of the time-dependent ionisation state for a wide variety of physical circumstances. Methods: A numerical model comprising the system of time-dependent ionisation equations for a particular element and tabulated values of plasma temperature as a function of time is developed. The tabulated values can be the solutions of an analytical model, the output from a numerical code or a set of observational measurements. An efficient numerical method to solve the ionisation equations is implemented. Results: A suite of tests is designed and run to demonstrate that the code provides reliable and accurate solutions for a number of scenarios including equilibration of the ion population and rapid heating followed by thermal conductive cooling. It is found that the solver can evolve the ionisation
14. Non-equilibrium nanosecond-pulsed plasma generation in the liquid phase (water, PDMS) without bubbles: fast imaging, spectroscopy and leader-type model
Dobrynin, Danil; Seepersad, Yohan; Pekker, Mikhail; Shneider, Mikhail; Friedman, Gary; Fridman, Alexander
2013-03-01
In this paper we report the results on study of the non-equilibrium nanosecond discharge generation in liquid media. Here we studied the discharge in both water and silicon transformer oil, and present our findings on discharge behaviour depending on global (applied) electric, discharge emission spectrum and shadow imaging of the discharge. We also discuss possible scenarios of non-equilibrium nanosecond discharge development and suggest that the discharge operates in a leader-type regime supported by the electrostriction effect—creation of nano-sized pores in liquid due to high local electric field.
15. Open problems in non-equilibrium physics
SciTech Connect
Kusnezov, D.
1997-09-22
The report contains viewgraphs on the following: approaches to non-equilibrium statistical mechanics; classical and quantum processes in chaotic environments; classical fields in non-equilibrium situations: real time dynamics at finite temperature; and phase transitions in non-equilibrium conditions.
16. Non-equilibrium many body dynamics
SciTech Connect
Creutz, M.; Gyulassy, M.
1997-09-22
This Riken BNL Research Center Symposium on Non-Equilibrium Many Body Physics was held on September 23-25, 1997 as part of the official opening ceremony of the Center at Brookhaven National Lab. A major objective of theoretical work at the center is to elaborate on the full spectrum of strong interaction physics based on QCD, including the physics of confinement and chiral symmetry breaking, the parton structure of hadrons and nuclei, and the phenomenology of ultra-relativistic nuclear collisions related to the up-coming experiments at RHIC. The opportunities and challenges of nuclear and particle physics in this area naturally involve aspects of the many body problem common to many other fields. The aim of this symposium was to find common theoretical threads in the area of non-equilibrium physics and modern transport theories. The program consisted of invited talks on a variety topics from the fields of atomic, condensed matter, plasma, astrophysics, cosmology, and chemistry, in addition to nuclear and particle physics. Separate abstracts have been indexed into the database for contributions to this workshop.
17. Simulation of a non-equilibrium helium plasma bullet emerging into oxygen at high pressure (250-760 Torr) and interacting with a substrate
Yan, Wen; Economou, Demetre J.
2016-09-01
A two-dimensional computational study of a plasma bullet emanating from a helium gas jet in oxygen ambient at high pressure (250-760 Torr) was performed, with emphasis on the bullet interaction with a substrate. Power was applied in the form of a trapezoidal +5 kV pulse lasting 150 ns. A neutral gas transport model was employed to predict the concentration distributions of helium and oxygen in the system. These were then used in a plasma dynamics model to investigate the characteristics of the plasma bullet during its propagation and interaction with a substrate. Upon ignition, the discharge first propagated as a surface wave along the inner wall of the containing tube, and then exited the tube with a well-defined ionization front (streamer or plasma bullet). The plasma bullet evolved from a hollow (donut-shaped) feature to one where the maximum of ionization was on axis. The bullet propagated in the gap between the tube exit and the substrate with an average speed of ˜2 × 105 m/s. Upon encountering a metal substrate, the bullet formed a conductive channel to the substrate. Upon encountering a dielectric substrate, the bullet turned into an ionization wave propagating radially along the substrate surface. For a conductive substrate, the radial species fluxes to the surface peaked on the symmetry axis. For a dielectric substrate, a ring-shaped flux distribution was observed. The "footprint" of plasma-surface interaction increased either by decreasing the gap between tube exit and substrate, decreasing the relative permittivity of an insulating substrate, or decreasing pressure. As the system pressure was lowered from 760 to 250 Torr, the discharge was initiated earlier, and the plasma bullet propagation speed increased. A reverse electric field developed during the late stages of the ramp-down of the pulse, which accelerated electrons forming a brief backward discharge.
18. Non-equilibrium Kinematics in Merging Galaxies
Mihos, J. C.
Measurements of the kinematics of merging galaxies are often used to derive dynamical masses, study evolution onto the fundamental plane, or probe relaxation processes. These measurements are often compromised to some degree by strong non-equilibrium motions in the merging galaxies. This talk focuses on the evolution of the kinematics of merging galaxies, and highlights some pitfalls which occur when studying non-equilibrium systems.
19. Characterization of non equilibrium effects on high quality critical flows
SciTech Connect
Camelo, E.; Lemonnier, H.; Ochterbeck, J.
1995-09-01
The appropriate design of various pieces of safety equipment such as relief systems, relies on the accurate description of critical flow phenomena. Most of the systems of industrial interest are willing to be described by one-dimensional area-averaged models and a large fraction of them involves multi-component high gas quality flows. Within these circumstances, the flow is very likely to be of an annular dispersed nature and its description by two-fluid models requires various closure relations. Among the most sensitive closures, there is the interfacial area and the liquid entrained fraction. The critical flowrate depends tremendously on the accurate description of the non equilibrium which results from the correctness of the closure equations. In this study, two-component flows are emphasized and non equilibrium results mainly form the differences in the phase velocities. It is therefore of the utmost importance to have reliable data to characterize non equilibrium phenomena and to assess the validity of the closure models. A comprehensive description of air-water nozzle flows, with emphasis on the effect of the nozzle geometry, has been undertaken and some of the results are presented here which helps understanding the overall flow dynamics. Besides the critical flowrate, the presented material includes pressure profiles, droplet size and velocity, liquid film flowrate and liquid film thickness.
20. Optical Properties in Non-equilibrium Phase Transitions
SciTech Connect
Ao, T; Ping, Y; Widmann, K; Price, D F; Lee, E; Tam, H; Springer, P T; Ng, A
2006-01-05
An open question about the dynamical behavior of materials is how phase transition occurs in highly non-equilibrium systems. One important class of study is the excitation of a solid by an ultrafast, intense laser. The preferential heating of electrons by the laser field gives rise to initial states dominated by hot electrons in a cold lattice. Using a femtosecond laser pump-probe approach, we have followed the temporal evolution of the optical properties of such a system. The results show interesting correlation to non-thermal melting and lattice disordering processes. They also reveal a liquid-plasma transition when the lattice energy density reaches a critical value.
1. Non-equilibrium Thermodynamics of Rayleigh-Taylor Instability
Sengupta, Tapan K.; Sengupta, Aditi; Sengupta, Soumyo; Bhole, Ashish; Shruti, K. S.
2016-04-01
Here, the fundamental problem of Rayleigh-Taylor instability (RTI) is studied by direct numerical simulation (DNS), where the two air masses at different temperatures, kept apart initially by a non-conducting horizontal interface in a 2D box, are allowed to mix. Upon removal of the partition, mixing is controlled by RTI, apart from mutual mass, momentum, and energy transfer. To accentuate the instability, the top chamber is filled with the heavier (lower temperature) air, which rests atop the chamber containing lighter air. The partition is positioned initially at mid-height of the box. As the fluid dynamical system considered is completely isolated from outside, the DNS results obtained without using Boussinesq approximation will enable one to study non-equilibrium thermodynamics of a finite reservoir undergoing strong irreversible processes. The barrier is removed impulsively, triggering baroclinic instability by non-alignment of density, and pressure gradient by ambient disturbances via the sharp discontinuity at the interface. Adopted DNS method has dispersion relation preservation properties with neutral stability and does not require any external initial perturbations. The complete inhomogeneous problem with non-periodic, no-slip boundary conditions is studied by solving compressible Navier-Stokes equation, without the Boussinesq approximation. This is important as the temperature difference between the two air masses considered is high enough (Δ T = 70 K) to invalidate Boussinesq approximation. We discuss non-equilibrium thermodynamical aspects of RTI with the help of numerical results for density, vorticity, entropy, energy, and enstrophy.
2. Non-equilibrium Dynamics of DNA Nanotubes
Can the fundamental processes that underlie molecular biology be understood and simulated by DNA nanotechnology? The early development of DNA nanotechnology by Ned Seeman was driven by the desire to find a solution to the protein crystallization problem. Much of the later development of the field was also driven by envisioned applications in computing and nanofabrication. While the DNA nanotechnology community has assembled a versatile tool kit with which DNA nanostructures of considerable complexity can be assembled, the application of this tool kit to other areas of science and technology is still in its infancy. This dissertation reports on the construction of non-equilibrium DNA nanotube dynamic to probe molecular processes in the areas of hydrodynamics and cytoskeletal behavior. As the first example, we used DNA nanotubes as a molecular probe for elongational flow measurement in different micro-scale flow settings. The hydrodynamic flow in the vicinity of simple geometrical objects, such as a rigid DNA nanotube, is amenable to rigorous theoretical investigation. We measured the distribution of elongational flows produced in progressively more complex settings, ranging from the vicinity of an orifice in a microfluidic chamber to within a bursting bubble of Pacific ocean water. This information can be used to constrain theories on the origin of life in which replication involves a hydrodynamically driven fission process, such as the coacervate fission proposed by Oparin. A second theme of this dissertation is the bottom-up construction of a de novo artificial cytoskeleton with DNA nanotubes. The work reported here encompasses structural, locomotion, and control aspects of non-equilibrium cytoskeletal behavior. We first measured the kinetic parameters of DNA nanotube assembly and tested the accuracy of the existing polymerization models in the literature. Toward recapitulation of non-equilibrium cytoskeletal dynamics, we coupled the polymerization of DNA
SciTech Connect
Philip, Bobby; Wang, Zhen; Berrill, Mark A; Rodriguez Rodriguez, Manuel; Pernice, Michael
2013-01-01
We describe methods for accurate and efficient long term time integra- tion of non-equilibrium radiation diffusion systems: implicit time integration for effi- cient long term time integration of stiff multiphysics systems, local control theory based step size control to minimize the required global number of time steps while control- ling accuracy, dynamic 3D adaptive mesh refinement (AMR) to minimize memory and computational costs, Jacobian Free Newton-Krylov methods on AMR grids for efficient nonlinear solution, and optimal multilevel preconditioner components that provide level independent solver convergence.
4. Turbulence modeling for non-equilibrium flow
NASA Technical Reports Server (NTRS)
Durbin, P. A.
1995-01-01
The work performed during this year has involved further assessment and extension of the k-epsilon-v(exp 2) model, and initiation of work on scalar transport. The latter is introduced by the contribution of Y. Shabany to this volume. Flexible, computationally tractable models are needed for engineering CFD. As computational technology has progressed, the ability and need to use elaborate turbulence closure models has increased. The objective of our work is to explore and develop new analytical frameworks that might extend the applicability of the modeling techniques. In past years the development of a method for near-wall modeling was described. The method has been implemented into a CFD code and its viability has been demonstrated by various test cases. Further tests are reported herein. Non-equilibrium near-wall models are needed for some heat transfer applications. Scalar transport seems generally to be more sensitive to non-equilibrium effects than is momentum transport. For some applications turbulence anisotropy plays a role and an estimate of the full Reynolds stress tensor is needed. We have begun work on scalar transport per se, but in this brief I will only report on an extension of the k-epsilon-v(exp 2) model to predict the Reynolds stress tensor.
5. In command of non-equilibrium.
PubMed
2016-05-21
The second law of thermodynamics is well known for determining the direction of spontaneous processes in the laboratory, life and the universe. It is therefore often called the arrow of time. Less often discussed but just as important is the effect of kinetic barriers which intercept equilibration and preserve highly ordered, high energy non-equilibrium states. Examples of such states are many modern materials produced intentionally for technological applications. Furthermore, all living organisms fuelled directly by photosynthesis and those fuelled indirectly by living on high energy nutrition represent preserved non-equilibrium states. The formation of these states represents the local reversal of the arrow of time which only seemingly violates the second law. It has been known since the seminal work of Prigogine that the stabilisation of these states inevitably requires the dissipation of energy in the form of waste heat. It is this feature of waste heat dissipation following the input of energy that drives all processes occurring at a non-zero rate. Photosynthesis, replication of living organisms, self-assembly, crystal shape engineering and distillation have this principle in common with the well-known Carnot cycle in the heat engine. Drawing on this analogy, we subsume these essential and often sophisticated driven processes under the term machinery of life. PMID:27146424
6. Non-equilibrium quantum heat machines
Alicki, Robert; Gelbwaser-Klimovsky, David
2015-11-01
Standard heat machines (engine, heat pump, refrigerator) are composed of a system (working fluid) coupled to at least two equilibrium baths at different temperatures and periodically driven by an external device (piston or rotor) sometimes called the work reservoir. The aim of this paper is to go beyond this scheme by considering environments which are stationary but cannot be decomposed into a few baths at thermal equilibrium. Such situations are important, for example in solar cells, chemical machines in biology, various realizations of laser cooling or nanoscopic machines driven by laser radiation. We classify non-equilibrium baths depending on their thermodynamic behavior and show that the efficiency of heat machines powered by them is limited by the generalized Carnot bound.
7. A numerical study of high-pressure non-equilibrium streamers for combustion ignition application
Breden, Douglas; Raja, Laxminarayan L.; Idicheria, Cherian A.; Najt, Paul M.; Mahadevan, Shankar
2013-08-01
We present a computational simulation study of non-equilibrium streamer discharges in a coaxial electrode and a corona geometry for automotive combustion ignition applications. The streamers propagate in combustible fuel-air mixtures at high pressures representative of internal combustion engine conditions. The study was performed using a self-consistent, two-temperature plasma model with finite-rate plasma chemical kinetics. Positive high voltage pulses of order tens of kV and duration of tens of nanoseconds were applied to the powered inner cylindrical electrode which resulted in the formation and propagation of a cathode-directed streamer. The resulting spatial and temporal production of active radical species such as O, H, and singlet delta oxygen is quantified and compared for lean and stoichiometric fuel-air mixtures. For the coaxial electrode geometry, the discharge is characterized by a primary streamer that bridges the inter-electrode gap and a secondary streamer that develops in the wake of the primary streamer. Most of the radicals are produced in the secondary streamer. For the corona geometry, only the primary streamer is observed and the radicals are produced throughout the length of the primary streamer column. The stoichiometry of the mixture was observed to have a relatively small effect on both the plasma discharge structure and the resulting yield of radical species.
8. Non-equilibrium diffusion combustion of a fuel droplet
Tyurenkova, Veronika V.
2012-06-01
A mathematical model for the non-equilibrium combustion of droplets in rocket engines is developed. This model allows to determine the divergence of combustion rate for the equilibrium and non-equilibrium model. Criterion for droplet combustion deviation from equilibrium is introduced. It grows decreasing droplet radius, accommodation coefficient, temperature and decreases on decreasing diffusion coefficient. Also divergence from equilibrium increases on reduction of droplet radius. Droplet burning time essentially increases under non-equilibrium conditions. Comparison of theoretical and experimental data shows that to have adequate solution for small droplets it is necessary to use the non-equilibrium model.
9. Non-equilibrium calcium ionisation in the solar atmosphere
Wedemeyer-Böhm, S.; Carlsson, M.
2011-04-01
Context. The chromosphere of the Sun is a temporally and spatially very varying medium for which the assumption of ionisation equilibrium is questionable. Aims: Our aim is to determine the dominant processes and timescales for the ionisation equilibrium of calcium under solar chromospheric conditions. Methods: The study is based on numerical simulations with the RADYN code, which combines hydrodynamics with a detailed solution of the radiative transfer equation. The calculations include a detailed non-equilibrium treatment of hydrogen, calcium, and helium. Next to an hour long simulation sequence, additional simulations are produced, for which the stratification is slightly perturbed so that a ionisation relaxation timescale can be determined. The simulations are characterised by upwards propagating shock waves, which cause strong temperature fluctuations and variations of the (non-equilibrium) ionisation degree of calcium. Results: The passage of a hot shock front leads to a strong net ionisation of Ca II, rapidly followed by net recombination. The relaxation timescale of the calcium ionisation state is found to be of the order of a few seconds at the top of the photosphere and 10 to 30 s in the upper chromosphere. At heights around 1 Mm, we find typical values around 60 s and in extreme cases up to ~150 s. Generally, the timescales are significantly reduced in the wakes of ubiquitous hot shock fronts. The timescales can be reliably determined from a simple analysis of the eigenvalues of the transition rate matrix. The timescales are dominated by the radiative recombination from Ca III into the metastable Ca II energy levels of the 4d 2D term. These transitions depend strongly on the density of free electrons and therefore on the (non-equilibrium) ionisation degree of hydrogen, which is the main electron donor. Conclusions: The ionisation/recombination timescales derived here are too long for the assumption of an instantaneous ionisation equilibrium to be valid
10. Characteristics of Low Power CH4/Air Atmospheric Pressure Plasma Jet
ZHANG, Jun; XIAO, Dezhi; FANG, Shidong; SHU, Xingsheng; ZUO, Xiao; CHENG, Cheng; MENG, Yuedong; WANG, Shouguo
2015-03-01
A low power atmospheric pressure plasma jet driven by a 24 kHz AC power source and operated with a CH4/air gas mixture has been investigated by optical emission spectrometer. The plasma parameters including the electron excitation temperature, vibrational temperature and rotational temperature of the plasma jet at different discharge powers are diagnosed based on the assumption that the kinetic energy of the species obeys the Boltzmann distribution. The electron density at different power is also investigated by Hβ Stark broadening. The results show that the plasma source works under non-equilibrium conditions. It is also found that the vibrational temperature and rotational temperature increase with discharge power, whereas the electron excitation temperature seems to have a downward trend. The electron density increases from 0.8 × 1021 m-3 to 1.1 × 1021 m-3 when the discharge power increases from 53 W to 94 W.
11. Is it possible to deduce the ground state OH density from relative optical emission intensities of the OH(A 2Σ+-X 2Πi) transition in atmospheric pressure non-equilibrium plasmas?—An analysis of self-absorption
2016-08-01
The measurement of absolute densities of reactive species and radicals such as OH is of growing interest for many plasma applications. In this paper, we extend the use of a self-absorption model for atomic emission spectroscopy to molecular emission spectroscopy. The proposed analysis of self-absorbed molecular emission spectra is a simple and inexpensive method to determine OH(X) densities and rotational temperatures compared to laser induced fluorescence. We compare the recorded absolute OH density in a non-equilibrium diffuse atmospheric-pressure RF glow discharge by this method with broadband UV absorption considering a number of rotational lines with J‧ ⩽ 6.5, the detection limit of the line integrated OH(X) density with this method is of the order of 2 × 1019 m‑2. The accuracy of the density is sensitive to the rotational temperature of the OH(A) state and the non-equilibrium rotational population distribution.
12. Is it possible to deduce the ground state OH density from relative optical emission intensities of the OH(A 2Σ+-X 2Πi) transition in atmospheric pressure non-equilibrium plasmas?—An analysis of self-absorption
2016-08-01
The measurement of absolute densities of reactive species and radicals such as OH is of growing interest for many plasma applications. In this paper, we extend the use of a self-absorption model for atomic emission spectroscopy to molecular emission spectroscopy. The proposed analysis of self-absorbed molecular emission spectra is a simple and inexpensive method to determine OH(X) densities and rotational temperatures compared to laser induced fluorescence. We compare the recorded absolute OH density in a non-equilibrium diffuse atmospheric-pressure RF glow discharge by this method with broadband UV absorption considering a number of rotational lines with J‧ ⩽ 6.5, the detection limit of the line integrated OH(X) density with this method is of the order of 2 × 1019 m-2. The accuracy of the density is sensitive to the rotational temperature of the OH(A) state and the non-equilibrium rotational population distribution.
13. Non equilibrium electronic transport in multilayered nanostructures
Cruz-Rojas, Jesus
Recent advances in strongly correlated materials have produced systems with novel and interesting properties like high Tc superconductors, Mott insulators and others. These novel properties have sparked an interest in industry as well as in academia as new devices are being developed. One such kind of device that can be fabricated is a heterostructure, in which layers of different compounds are stacked in a single direction. Modern deposition techniques like electron beam epitaxy, in which atomic layers of different materials are deposited one at a time creating the device, are capable of fabricating heterostructures with atomic precision. We propose a technique to study heterostructures composed of strongly correlated materials out of equilibrium. By using the Keldysh Green's function formalism in the dynamical mean field theory (DMFT) framework the properties of a multilayered device are analyzed. The system is composed of infinite dimensional 2D lattices, stacked in the z direction. The first and last planes are then connected to a bulk reservoir, and several metallic planes are used to connect the bulk reservoir to the barrier region. The barrier region is the system of interest, also known as the device. The device is composed of a number of planes where the system correlations have been turned on. The correlations are then model by using the Falicov-Kimball Hamiltonian. The device is then connected to the bulk once again from the opposite side using metallic planes creating a symmetric system. In order to study the non equilibrium properties of the device a linear vector potential A(t) = A0 + tE is turned on a long time in the past for a unit of time and then turned off. This in turn will create a current in the bulk, in effect current biasing the device, as opposed to a voltage bias in which opposite sides of the device are held to a different potential. In this document we will explain the importance of the subject, we will derive and develop the algorithm
14. Non-equilibrium Ionization Modeling of Simulated Pseudostreamers in a Solar Corona Model
Shen, Chengcai; Raymond, John C.; Mikić, Zoran; Linker, Jon; Reeves, Katharine K.; Murphy, Nicholas A.
2015-04-01
Time-dependent ionization is important for diagnostics of coronal streamers, where the thermodynamic time scale could be shorter than the ionization or recombination time scales, and ions are therefor in non-equilibrium ionization states. In this work, we perform post-processing time-dependent ionization calculations for a three dimensional solar corona and inner heliosphere model from Predictive Sciences Inc. (Mikić & Linker 1999) to analyze the influence of non-equilibrium ionization on emission from coronal streamers. Using the plasma temperature, density, velocity and magnetic field distributions provided by the 3D MHD simulation covering the Whole Sun Month (Carrington rotation CR1913, 1996 August 22 to September 18), we calculate non-equilibrium ionization states in the region around a pseudostreamer. We then obtain the synthetic emissivities with the non-equilibrium ion populations. Under the assumption that the corona is optically thin, we also obtain intensity profiles of several emission lines. We compare our calculations with intensities of Lyman-alpha lines and OVI lines from SOHO/Ultraviolet Coronagraph Spectrometer (UVCS) observations at 14 different heights. The results show that intensity profiles of both Lyman-alpha and OVI lines match well UVCS observations at low heights. At large heights, OVI intensites are higher for non-equilibrium ionization than equilibrium ionization inside this pseudostreamer. The assumption of ionization equilibrium would lead to a underestimate of the OVI intensity by about ten percent at a height of 2 solar radii, and the difference between these two ionization cases increases with height. The intensity ratio of OVI 1032 line to OVI 1037 lines is also obtained for non-equilibrium ionization modeling.
15. Speeding Up Calculations Of The Non-equilibrium Ionization Model
Ji, Li; Noble, M.; Schulz, N. S.; Nowak, M. A.; Marshall, H. L.
2008-03-01
By taking advantage of the atomic data and physics from the equilibrium photoionization model of XSTAR, we are extending our non-equilibrium collisional ionization code to photoionized plasmas. The expanded model will allow us to study processes in a wide range of astrophysical scenarios -- such as colliding winds in X-ray binaries, outflows in AGNs, and shock flows in the IGM, but presents significant challenges. Chief among these are that the new model is expensive to compute and difficult to compare directly with HETG observations. We discuss how parallelism and modular software techniques are being brought to bear on these problems, in the context of several applications: (1) emission measurement analysis for the accretion disk corona of HerX-1, using XSTAR within the Parallel Virtual Machine; (2) using ISIS for direct ionization analysis and line diagnostics of the plane shock model, via our dynamically loadable interface to selected routines from the XSPEC vpshock model; and (3) computing atomic rates directly in ISIS by way of our dynamically loadable XSTAR module.
16. Electrolytes: transport properties and non-equilibrium thermodynamics
SciTech Connect
Miller, D.G.
1980-12-01
This paper presents a review on the application of non-equilibrium thermodynamics to transport in electrolyte solutions, and some recent experimental work and results for mutual diffusion in electrolyte solutions.
17. Statistical physics of shear flow: a non-equilibrium problem
Evans, R. M. L.
2010-09-01
Complex fluids are easily and reproducibly driven into non-equilibrium steady states by the action of shear flow. The statistics of the microstructure of non-equilibrium fluids is important to the material properties of every complex fluid that flows, e.g. axle grease on a rotating bearing; blood circulating in capillaries; molten plastic flowing into a mould; the non-equilibrium onion phase of amphiphiles used for drug delivery; the list is endless. Such states are as diverse and interesting as equilibrium states, but are not governed by the same statistics as equilibrium materials. I review some recently discovered principles governing the probabilities of various types of molecular re-arrangements taking place within a sheared fluid. As well as providing new foundations for the study of non-equilibrium matter, the principles are applied to some simple models of particles interacting under flow, showing that the theory exhibits physically convincing behaviour.
18. Antimicrobial Applications of Ambient--Air Plasmas
Pavlovich, Matthew John
The emerging field of plasma biotechology studies the applications of the plasma phase of matter to biological systems. "Ambient-condition" plasmas created at or near room temperature and atmospheric pressure are especially promising for biomedical applications because of their convenience, safety to patients, and compatibility with existing medical technology. Plasmas can be created from many different gases; plasma made from air contains a number of reactive oxygen and nitrogen species, or RONS, involved in various biological processes, including immune activity, signaling, and gene expression. Therefore, ambient-condition air plasma is of particular interest for biological applications. To understand and predict the effects of treating biological systems with ambient-air plasma, it is necessary to characterize and measure the chemical species that these plasmas produce. Understanding both gaseous chemistry and the chemistry in plasma-treated aqueous solution is important because many biological systems exist in aqueous media. Existing literature about ambient-air plasma hypothesizes the critical role of reactive oxygen and nitrogen species; a major aim of this dissertation is to better quantify RONS by produced ambient-air plasma and understand how RONS chemistry changes in response to different plasma processing conditions. Measurements imply that both gaseous and aqueous chemistry are highly sensitive to operating conditions. In particular, chemical species in air treated by plasma exist in either a low-power ozone-dominated mode or a high-power nitrogen oxide-dominated mode, with an unstable transition region at intermediate discharge power and treatment time. Ozone (O3) and nitrogen oxides (NO and NO2, or NOx) are mutually exclusive in this system and that the transition region corresponds to the transition from ozone- to nitrogen oxides-mode. Aqueous chemistry agrees well with to air plasma chemistry, and a similar transition in liquid-phase composition
19. Non-Equilibrium Effects on Hypersonic Turbulent Boundary Layers
Kim, Pilbum
Understanding non-equilibrium effects of hypersonic turbulent boundary layers is essential in order to build cost efficient and reliable hypersonic vehicles. It is well known that non-equilibrium effects on the boundary layers are notable, but our understanding of the effects are limited. The overall goal of this study is to improve the understanding of non-equilibrium effects on hypersonic turbulent boundary layers. A new code has been developed for direct numerical simulations of spatially developing hypersonic turbulent boundary layers over a flat plate with finite-rate reactions. A fifth-order hybrid weighted essentially non-oscillatory scheme with a low dissipation finite-difference scheme is utilized in order to capture stiff gradients while resolving small motions in turbulent boundary layers. The code has been validated by qualitative and quantitative comparisons of two different simulations of a non-equilibrium flow and a spatially developing turbulent boundary layer. With the validated code, direct numerical simulations of four different hypersonic turbulent boundary layers, perfect gas and non-equilibrium flows of pure oxygen and nitrogen, have been performed. In order to rule out uncertainties in comparisons, the same inlet conditions are imposed for each species, and then mean and turbulence statistics as well as near-wall turbulence structures are compared at a downstream location. Based on those comparisons, it is shown that there is no direct energy exchanges between internal and turbulent kinetic energies due to thermal and chemical non-equilibrium processes in the flow field. Instead, these non-equilibria affect turbulent boundary layers by changing the temperature without changing the main characteristics of near-wall turbulence structures. This change in the temperature induces the changes in the density and viscosity and the mean flow fields are then adjusted to satisfy the conservation laws. The perturbation fields are modified according to
20. Detection of Non-Equilibrium Fluctuations in Active Gels
Bacanu, Alexandru; Broedersz, Chase; Gladrow, Jannes; Mackintosh, Fred; Schmidt, Christoph; Fakhri, Nikta
Active force generation at the molecular scale in cells can result in stochastic non-equilibrium dynamics on mesoscpopic scales. Molecular motors such as myosin can drive steady-state stress fluctuations in cytoskeletal networks. Here, we present a non-invasive technique to probe non-equilibrium fluctuations in an active gel using single-walled carbon nanotubes (SWNTs). SWNTs are semiflexible polymers with intrinsic fluorescence in the near infrared. Both thermal and active motor-induced forces in the network induce transverse fluctuations of SWNTs. We demonstrate that active driven shape fluctuations of the SWNTs exhibit dynamics that reflect the non-equilibrium activity, in particular the emergence of correlations between the bending modes. We discuss the observation of breaking of detailed balance in this configurational space of the SWNT probes. Supported by National Defense Science and Engineering Graduate Student Fellowship (NDSEG).
1. The influence of non-equilibrium pressure on rotating flows
This study was undertaken to investigate the influence of pressure relaxation on steady, incompressible flows with strong streamline curvature. In the early part of this dissertation research, the significance of non-equilibrium pressure forces in controlling the structure of a steady, two dimensional axial vortex was demonstrated. In order to extend the study of pressure relaxation influences on more complex rotating flows, this dissertation has examined other rotating flow features that can be associated with hurricanes, tornadoes and dust devils. To model these flows, modified boundary layer equations were developed for a fluid column rotating near a solid plane including the influence of non-equilibrium pressure forces. The far-field boundary conditions were inferred using the asymptotic behavior of the governing equations, and the boundary conditions for the axial and radial components of velocity were shown to be dependent on the pressure relaxation coefficient, η p, and the characteristic angular velocity of the rotating fluid column, ω. This research has shown for the first time that the inclusion of non-equilibrium pressure results in a free-standing stagnation plane at the top of a funnel shaped rotating fluid column, which is consistent with observational data for hurricanes, tornadoes and dust devils. It has also been shown that in the absence of non-equilibrium pressure, the stagnation plane for rotating flows cannot be observed. The velocity and pressure distributions resulting from incorporating non-equilibrium pressure effects were then compared with available observational data for tornadoes and dust devils. The general profiles of the velocity and pressure distributions were found to be in good agreement with physical measurements, which was not possible without introducing empirical turbulence effects, in the absence of non-equilibrium pressure effects.
2. Stochastic linearization of turbulent dynamics of dispersive waves in equilibrium and non-equilibrium state
Jiang, Shixiao W.; Lu, Haihao; Zhou, Douglas; Cai, David
2016-08-01
Characterizing dispersive wave turbulence in the long time dynamics is central to understanding of many natural phenomena, e.g., in atmosphere ocean dynamics, nonlinear optics, and plasma physics. Using the β-Fermi-Pasta-Ulam nonlinear system as a prototypical example, we show that in thermal equilibrium and non-equilibrium steady state the turbulent state even in the strongly nonlinear regime possesses an effective linear stochastic structure in renormalized normal variables. In this framework, we can well characterize the spatiotemporal dynamics, which are dominated by long-wavelength renormalized waves. We further demonstrate that the energy flux is nearly saturated by the long-wavelength renormalized waves in non-equilibrium steady state. The scenario of such effective linear stochastic dynamics can be extended to study turbulent states in other nonlinear wave systems.
3. Review of Non-Equilibrium Plasmadynamics to Predict Energy Transfer in Arcjet Thrusters
Krier, Herman
1998-10-01
Both chemical and thermal processes in an electrothermal arcjet are described as non-equilibrium. Arc current is converted to electron thermal energy through ohmic dissipation. The electrons transfer thermal energy to heavy species in the arc plasma through collisions. This energy is then converted to kinetic energy (and thrust) as the fluid accelerates through the nozzle. The paper presents an axisymmetric, steady, laminar, continuum flow model, supporting a two-temperature kinetic and chemical non-equilibrium, formulated for a direct current arcjet with variabe mixture ratios of nitrogen and hydrogen. Seven species (ions, atoms, electons) assumed with finite rate chemistry accounted for. The model predictions are compared to experiments with a NASA 1 kW hydrazine propellant arcjet.Background information.
4. SciTech Connect
Gallis, Michail A.; Bond, Ryan Bomar; Torczynski, John Robert
2010-04-01
A set of Direct Simulation Monte Carlo (DSMC) chemical-reaction models recently proposed by Bird and based solely on the collision energy and the vibrational energy levels of the species involved is applied to calculate nonequilibrium chemical-reaction rates for atmospheric reactions in hypersonic flows. The DSMC non-equilibrium model predictions are in good agreement with theoretical models and experimental measurements. The observed agreement provides strong evidence that modeling chemical reactions using only the collision energy and the vibrational energy levels provides an accurate method for predicting non-equilibrium chemical-reaction rates.
5. Non-equilibrium model of spray-stratified atmospheric boundary layer under high wind conditions
Rastigejev, Yevgenii; Suslov, Sergey
2014-11-01
Tropical cyclone is a complex meteorological phenomenon which dynamics is defined by a wide variety of factors including exchange of momentum, heat and moisture between the atmosphere and the ocean. Ocean spray plays an important role in this air-sea interaction. Here we developed a two-temperature non-equilibrium variable density (non-Bousinessq) turbulence closure model to describe the ocean spray-stratified hurricane boundary layer structure and dynamics. The model consistently describes a two-way coupling between mechanical and thermodynamic influences of the ocean spray. The obtained results confirm that the impact of non-equilibrium effects is significant over the complete range of possible spray concentration values, therefore has to be included into a consistent parameterization of moisture, heat and momentum transfer process over the ocean under high wind condition of a hurricane. NSF HRD-1036563.
6. Strongly Non-equilibrium Dynamics of Nanochannel Confined DNA
Reisner, Walter
Nanoconfined DNA exhibits a wide-range of fascinating transient and steady-state non-equilibrium phenomena. Yet, while experiment, simulation and scaling analytics are converging on a comprehensive picture regarding the equilibrium behavior of nanochannel confined DNA, non-equilibrium behavior remains largely unexplored. In particular, while the DNA extension along the nanochannel is the key observable in equilibrium experiments, in the non-equilibrium case it is necessary to measure and model not just the extension but the molecule's full time-dependent one-dimensional concentration profile. Here, we apply controlled compressive forces to a nanochannel confined molecule via a nanodozer assay, whereby an optically trapped bead is slid down the channel at a constant speed. Upon contact with the molecule, a propagating concentration shockwave'' develops near the bead and the molecule is dynamically compressed. This experiment, a single-molecule implementation of a macroscopic cylinder-piston apparatus, can be used to observe the molecule response over a range of forcings and benchmark theoretical description of non-equilibrium behavior. We show that the dynamic concentration profiles, including both transient and steady-state response, can be modelled via a partial differential evolution equation combining nonlinear diffusion and convection. Lastly, we present preliminary results for dynamic compression of multiple confined molecules to explore regimes of segregation and mixing for multiple chains in confinement.
7. Caloric and entropic temperatures in non-equilibrium steady states
Jou, D.; Restuccia, L.
2016-10-01
We examine the non-equilibrium consequences of two different definitions of temperature in systems out of equilibrium: one is based on the internal energy (caloric temperature), and the other one on the entropy (entropic temperature). We discuss the relation between the values obtained from these two definitions in ideal gases and in two-level systems.
8. Evolution of a plasma vortex in air.
PubMed
Tsai, Cheng-Mu; Chu, Hong-Yu
2016-01-01
We report the generation of a vortex-shaped plasma in air by using a capacitively coupled dielectric barrier discharge system. We show that a vortex-shaped plasma can be produced inside a helium gas vortex and is capable of propagating for 3 cm. The fluctuation of the plasma ring shows a scaling relation with the Reynolds number of the vortex. The transient discharge reveals the property of corona discharge, where the conducting channel within the gas vortex and the blur plasma emission are observed at each half voltage cycle. PMID:26871181
9. Evolution of a plasma vortex in air.
PubMed
Tsai, Cheng-Mu; Chu, Hong-Yu
2016-01-01
We report the generation of a vortex-shaped plasma in air by using a capacitively coupled dielectric barrier discharge system. We show that a vortex-shaped plasma can be produced inside a helium gas vortex and is capable of propagating for 3 cm. The fluctuation of the plasma ring shows a scaling relation with the Reynolds number of the vortex. The transient discharge reveals the property of corona discharge, where the conducting channel within the gas vortex and the blur plasma emission are observed at each half voltage cycle.
NASA Technical Reports Server (NTRS)
Kruger, Charles H.; Laux, C. O.
2001-01-01
This report summarizes the results obtained during a research program on the infrared radiation of air plasmas conducted in the High Temperature Gasdynamics Laboratory at Stanford University under the direction of Professor Charles H. Kruger, with Dr. Christophe O. Laux as Associate Investigator. The goal of this research was to investigate the masking of infrared signatures by the air plasma formed behind the bow shock of high velocity missiles. To this end, spectral measurements and modeling were made of the radiation emitted between 2.4 and 5.5 micrometers by an atmospheric pressure air plasma in chemical and thermal equilibrium at a temperature of approximately 3000 K. The objective was to examine the spectral emission of air species including nitric oxide, atomic oxygen and nitrogen lines, molecular and atomic continua, as well as secondary species such as water vapor or carbon dioxide. The cold air stream injected in the plasma torch contained approximately 330 parts per million of CO2, which is the natural CO2 concentration in atmospheric air at room temperatures, and a small amount of water vapor with an estimated mole fraction of 3.8x10(exp -4).
11. Investigation of Non-Equilibrium Radiation for Earth Entry
NASA Technical Reports Server (NTRS)
Brandis, Aaron; Johnston, Chris; Cruden, Brett
2016-01-01
This paper presents measurements and simulations of non-equilibrium shock layer radiation relevant to high-speed Earth entry data obtained in the NASA Ames Research Center's Electric Arc Shock Tube (EAST) facility. The experiments were aimed at measuring the spatially and spectrally resolved radiance at relevant entry conditions for both an approximate Earth atmosphere (79 N2 : 21 O2) as well as a more accurate composition featuring the trace species Ar and CO2 (78.08 N2 : 20.95 O2 : 0.04 CO2 : 0.93 Ar). The experiments were configured to target a wide range of conditions, of which shots from 8 to 11.5 km/s at 0.2 Torr (26.7 Pa) are examined in this paper. The non-equilibrium component was chosen to be the focus of this study as it can account for a significant percentage of the emitted radiation for Earth entry, and more importantly, non-equilibrium has traditionally been assigned a large uncertainty for vehicle design. The main goals of this study are to present the shock tube data in the form of a non-equilibrium metric, evaluate the level of agreement between the experiment and simulations, identify key discrepancies and to promote discussion about various aspects of modeling non-equilibrium radiating flows. Radiance profiles integrated over discreet wavelength regions, ranging from the VUV through to the NIR, were compared in order to maximize both the spectral coverage and the number of experiments that could be used in the analysis. A previously defined non-equilibrium metric has been used to allow comparisons with several shots and reveal trends in the data. Overall, LAURAHARA is shown to under-predict EAST by as much as 50 and over-predict by as much as 20 depending on the shock speed. DPLRNEQAIR is shown to under-predict EAST by as much as 40 and over-predict by as much as 12 depending on the shock speed. In terms of an upper bound estimate for the absolute error in wall-directed heat flux, at the lower speeds investigated in this paper, 8 to 9 km/s, even
12. Boltzmann equation solver adapted to emergent chemical non-equilibrium
SciTech Connect
Birrell, Jeremiah; Wilkening, Jon; Rafelski, Johann
2015-01-15
We present a novel method to solve the spatially homogeneous and isotropic relativistic Boltzmann equation. We employ a basis set of orthogonal polynomials dynamically adapted to allow for emergence of chemical non-equilibrium. Two time dependent parameters characterize the set of orthogonal polynomials, the effective temperature T(t) and phase space occupation factor ϒ(t). In this first paper we address (effectively) massless fermions and derive dynamical equations for T(t) and ϒ(t) such that the zeroth order term of the basis alone captures the particle number density and energy density of each particle distribution. We validate our method and illustrate the reduced computational cost and the ability to easily represent final state chemical non-equilibrium by studying a model problem that is motivated by the physics of the neutrino freeze-out processes in the early Universe, where the essential physical characteristics include reheating from another disappearing particle component (e{sup ±}-annihilation)
13. Evolution of specialization under non-equilibrium population dynamics.
PubMed
Nurmi, Tuomas; Parvinen, Kalle
2013-03-21
We analyze the evolution of specialization in resource utilization in a mechanistically underpinned discrete-time model using the adaptive dynamics approach. We assume two nutritionally equivalent resources that in the absence of consumers grow sigmoidally towards a resource-specific carrying capacity. The consumers use resources according to the law of mass-action with rates involving trade-off. The resulting discrete-time model for the consumer population has over-compensatory dynamics. We illuminate the way non-equilibrium population dynamics affect the evolutionary dynamics of the resource consumption rates, and show that evolution to the trimorphic coexistence of a generalist and two specialists is possible due to asynchronous non-equilibrium population dynamics of the specialists. In addition, various forms of cyclic evolutionary dynamics are possible. Furthermore, evolutionary suicide may occur even without Allee effects and demographic stochasticity.
14. Entropy Production and Non-Equilibrium Steady States
Suzuki, Masuo
2013-01-01
The long-term issue of entropy production in transport phenomena is solved by separating the symmetry of the non-equilibrium density matrix ρ(t) in the von Neumann equation, as ρ(t) = ρs(t) + ρa(t) with the symmetric part ρs(t) and antisymmetric part ρa(t). The irreversible entropy production (dS/dt)irr is given in M. Suzuki, Physica A 390(2011)1904 by (dS/dt)irr = Tr( {H}(dρ s{(t)/dt))}/T for the Hamiltonian {H} of the relevant system. The general formulation of the extended von Neumann equation with energy supply and heat extraction is reviewed from the author's paper (M. S.,Physica A391(2012)1074). irreversibility; entropy production; transport phenomena; electric conduction; thermal conduction; linear response; Kubo formula; steady state; non-equilibrium density matrix; energy supply; symmetry-separated von Neumann equation; unboundedness.
15. Non-equilibrium Hybridization Expansion Impurity-solver
Dong, Qiaoyuan
2015-03-01
The study of non-equilibrium phenomena in strongly correlated systems has developed into one of the most active and exciting branches of condensed matter physics. Meanwhile, quantum impurity models play a prominent role as mathematical representations of quantum dots, single-molecule devices, and effective models for the dynamical mean field theory. We show results for a generalization of the hybridization expansion diagrammatic Monte Carlo technique for the Anderson impurity model. And we perform non-equilibrium calculations on the full Keldysh contour, where a dynamical sign problem vastly increases the complexity of real-time simulation. By further combining this method with a non-crossing approximation, our bold-line'' Monte Carlo can reach substantially longer times out of equilibrium than previously accessible, and provides an accurate description of quench and driven dynamics of correlated systems. Sponsored by the Department of Energy.
16. Towards Non-Equilibrium Dynamics with Trapped Ions
Silbert, Ariel; Jubin, Sierra; Doret, Charlie
2016-05-01
Atomic systems are superbly suited to the study of non-equilibrium dynamics. These systems' exquisite isolation from environmental perturbations leads to long relaxation times that enable exploration of far-from-equilibrium phenomena. One example of particular relevance to experiments in trapped ion quantum information processing, metrology, and precision spectroscopy is the approach to thermal equilibrium of sympathetically cooled linear ion chains. Suitable manipulation of experimental parameters permits exploration of the quantum-to-classical crossover between ballistic transport and diffusive, Fourier's Law conduction, a topic of interest not only to the trapped ion community but also for the development of microelectronic devices and other nanoscale structures. We present progress towards trapping chains of multiple co-trapped calcium isotopes geared towards measuring thermal equilibration and discuss plans for future experiments in non-equilibrium statistical mechanics. This work is supported by Cottrell College Science Award from the Research Corporation for Science Advancement and by Williams College.
17. Investigation of Non-Equilibrium Radiation for Earth Entry
NASA Technical Reports Server (NTRS)
Brandis, A. M.; Johnston, C. O.; Cruden, B. A.
2016-01-01
For Earth re-entry at velocities between 8 and 11.5 km/s, the accuracy of NASA's computational uid dynamic and radiative simulations of non-equilibrium shock layer radiation is assessed through comparisons with measurements. These measurements were obtained in the NASA Ames Research Center's Electric Arc Shock Tube (EAST) facility. The experiments were aimed at measuring the spatially and spectrally resolved radiance at relevant entry conditions for both an approximate Earth atmosphere (79% N2 : 21% O2 by mole) as well as a more accurate composition featuring the trace species Ar and CO2 (78.08% N2 : 20.95% O2 : 0.04% CO2 : 0.93% Ar by mole). The experiments were configured to target a wide range of conditions, of which shots from 8 to 11.5 km/s at 0.2 Torr (26.7 Pa) are examined in this paper. The non-equilibrium component was chosen to be the focus of this study as it can account for a significant percentage of the emitted radiation for Earth re-entry, and more importantly, non-equilibrium has traditionally been assigned a large uncertainty for vehicle design. The main goals of this study are to present the shock tube data in the form of a non-equilibrium metric, evaluate the level of agreement between the experiment and simulations, identify key discrepancies and to examine critical aspects of modeling non-equilibrium radiating flows. Radiance pro les integrated over discreet wavelength regions, ranging from the Vacuum Ultra Violet (VUV) through to the Near Infra-Red (NIR), were compared in order to maximize both the spectral coverage and the number of experiments that could be used in the analysis. A previously defined non-equilibrium metric has been used to allow comparisons with several shots and reveal trends in the data. Overall, LAURA/HARA is shown to under-predict EAST by as much as 40% and over-predict by as much as 12% depending on the shock speed. DPLR/NEQAIR is shown to under-predict EAST by as much as 50% and over-predict by as much as 20% depending
18. Approach to non-equilibrium behaviour in quantum field theory
SciTech Connect
Kripfganz, J.; Perlt, H.
1989-05-01
We study the real-time evolution of quantum field theoretic systems in non-equilibrium situations. Results are presented for the example of scalar /lambda//phi//sup 4/ theory. The degrees of freedom are discretized by studying the system on a torus. Short-wavelength modes are integrated out to one-loop order. The long-wavelength modes considered to be the relevant degrees of freedom are treated by semiclassical phase-space methods. /copyright/ 1989 Academic Press, Inc.
19. Tunneling Measurements of Charge Imbalance of Non-Equilibrium Superconductors
Yagi, R.; Utsunomiya, K.; Tsuboi, K.; Kubota, T.; Terao, Y.; Ikebuchi, Y.
2008-10-01
We have observed excess current due to charge imbalance in the voltage-current characteristics of a superconductor-insulator-normal (SIN) tunnel junction connected to a non-equilibrium superconductor. It was found that that the excess current was unchanged against the bias voltage as expected from the theory of charge imbalance. The estimated excess current approximately agreed with the estimation from one-dimensional diffusion model of charge imbalance transport.
20. Novel mapping in non-equilibrium stochastic processes
Heseltine, James; Kim, Eun-jin
2016-04-01
We investigate the time-evolution of a non-equilibrium system in view of the change in information and provide a novel mapping relation which quantifies the change in information far from equilibrium and the proximity of a non-equilibrium state to the attractor. Specifically, we utilize a nonlinear stochastic model where the stochastic noise plays the role of incoherent regulation of the dynamical variable x and analytically compute the rate of change in information (information velocity) from the time-dependent probability distribution function. From this, we quantify the total change in information in terms of information length { L } and the associated action { J }, where { L } represents the distance that the system travels in the fluctuation-based, statistical metric space parameterized by time. As the initial probability density function’s mean position (μ) is decreased from the final equilibrium value {μ }* (the carrying capacity), { L } and { J } increase monotonically with interesting power-law mapping relations. In comparison, as μ is increased from {μ }*,{ L } and { J } increase slowly until they level off to a constant value. This manifests the proximity of the state to the attractor caused by a strong correlation for large μ through large fluctuations. Our proposed mapping relation provides a new way of understanding the progression of the complexity in non-equilibrium system in view of information change and the structure of underlying attractor.
1. Non-equilibrium fission processes in intermediate energy nuclear collisions
SciTech Connect
Loveland, W.; Casey, C.; Xu, Z.; Seaborg, G.T.; Aleklett, K.; Sihver, L.
1989-04-01
We have measured the target fragment yields, angular and energy distributions for the interaction of 12-16 MeV/A/sup 32/S with /sup 165/Ho and /sup 197/Au and for the interaction of 32 and 44 MeV/A /sup 40/Ar with /sup 197/Au. The Au fission fragments associated with the peripheral collision peak in the folding angle distribution originate in a normal, ''slow'' fission process in which statistical equilibrium has been established. At the two lowest projectile energies, the Au fission fragments associated with the central collision peak in the folding angle distribution originate in part from ''fast'' (/tau//approximately//sup /minus/23/s), non-equilibrium processes. Most of the Ho fission fragments originate in non- equilibrium processes. The fast, non-equilibrium process giving rise to these fragments has many of the characteristics of ''fast fission'', but the cross sections associated with these fragments are larger than one would expect from current theories of ''fast fission. '' 14 refs., 8 figs.
2. Non-equilibrium Numerical Analysis of Microwave-supported Detonation Threshold Propagating through Diatomic Gas
Shiraishi, Hiroyuki
2015-09-01
Microwave-supported Detonation (MSD), one type of Microwave-supported Plasma (MSP), is considered as one of the most important phenomena because it can generate high pressure and high temperature for beam-powered space propulsion systems. In this study, I numerically simulate MSD waves propagating through a diatomic gas. In order to evaluate the threshold of beam intensity, I use the physical-fluid dynamics scheme, which has been developed for simulating unsteady and non-equilibrium LSD waves propagating through a hydrogen gas.
3. Measurement of air entrainment in plasma jets
Fincke, J. R.; Rodriquez, R.; Pentecost, C. G.
The concentration and temperature of air entrained into argon and helium plasma jets has been measured using coherent anti-Stokes Raman spectroscopy (CARS). The argon plasma flow field is characterized by a short region of well behaved laminar flow near the nozzle exit followed by an abrupt transition to turbulence. Once the transition of turbulence occurs, air is rapidly mixed into the jet core. The location of the transition region is determined by the rapid cooling of the jet and the resulting increase in Reynolds number. In contrast, the helium plasma flow field never exceeds a Reynolds number of 200 and remains laminar. The entrainment process in this case is controlled by molecular diffusion rather than turbulent mixing.
4. Measurement of air entrainment in plasma jets
SciTech Connect
Fincke, J.R.; Rodriquez, R.; Pentecost, C.G.
1990-01-01
The concentration and temperature of air entrained into argon and helium plasma jets has been measured using coherent anti-Stokes Raman spectroscopy (CARS). The argon plasma flow field is characterized by a short region of well behaved laminar flow near the nozzle exit followed by an abrupt transition to turbulence. Once the transition of turbulence occurs, air is rapidly mixed into the jet core. The location of the transition region is determined by the rapid cooling of the jet and the resulting increase in Reynolds number. In contrast, the helium plasma flow field never exceeds a Reynolds number of 200 and remains laminar. The entrainment process in this case is controlled by molecular diffusion rather than turbulent mixing. 9 refs., 5 figs., 1 tab.
5. Novel non-equilibrium modelling of a DC electric arc in argon
Baeva, M.; Benilov, M. S.; Almeida, N. A.; Uhrlandt, D.
2016-06-01
A novel non-equilibrium model has been developed to describe the interplay of heat and mass transfer and electric and magnetic fields in a DC electric arc. A complete diffusion treatment of particle fluxes, a generalized form of Ohm’s law, and numerical matching of the arc plasma with the space-charge sheaths adjacent to the electrodes are applied to analyze in detail the plasma parameters and the phenomena occurring in the plasma column and the near-electrode regions of a DC arc generated in atmospheric pressure argon for current levels from 20 A up to 200 A. Results comprising electric field and potential, current density, heating of the electrodes, and effects of thermal and chemical non-equilibrium are presented and discussed. The current-voltage characteristic obtained is in fair agreement with known experimental data. It indicates a minimum for arc current of about 80 A. For all current levels, a field reversal in front of the anode accompanied by a voltage drop of (0.7-2.6) V is observed. Another field reversal is observed near the cathode for arc currents below 80 A.
6. Air plasma effect on dental disinfection
SciTech Connect
Duarte, S.; Murata, R. M.; Saxena, D.; Kuo, S. P.; Chen, C. Y.; Huang, K. J.; Popovic, S.
2011-07-15
A nonthermal low temperature air plasma jet is characterized and applied to study the plasma effects on oral pathogens and biofilms. Experiments were performed on samples of six defined microorganisms' cultures, including those of gram-positive bacteria and fungi, and on a cultivating biofilm sample of Streptococcus mutans UA159. The results show that the plasma jet creates a zone of microbial growth inhibition in each treated sample; the zone increases with the plasma treatment time and expands beyond the entire region directly exposed to the plasma jet. With 30s plasma treatment twice daily during 5 days of biofilm cultivation, its formation was inhibited. The viability of S. mutans cells in the treated biofilms dropped to below the measurable level and the killed bacterial cells concentrated to local regions as manifested by the fluorescence microscopy via the environmental scanning electron microscope. The emission spectroscopy of the jet indicates that its plasma effluent carries an abundance of reactive atomic oxygen, providing catalyst for the observed plasma effect.
7. Air plasma effect on dental disinfection
Duarte, S.; Kuo, S. P.; Murata, R. M.; Chen, C. Y.; Saxena, D.; Huang, K. J.; Popovic, S.
2011-07-01
A nonthermal low temperature air plasma jet is characterized and applied to study the plasma effects on oral pathogens and biofilms. Experiments were performed on samples of six defined microorganisms' cultures, including those of gram-positive bacteria and fungi, and on a cultivating biofilm sample of Streptococcus mutans UA159. The results show that the plasma jet creates a zone of microbial growth inhibition in each treated sample; the zone increases with the plasma treatment time and expands beyond the entire region directly exposed to the plasma jet. With 30s plasma treatment twice daily during 5 days of biofilm cultivation, its formation was inhibited. The viability of S. mutans cells in the treated biofilms dropped to below the measurable level and the killed bacterial cells concentrated to local regions as manifested by the fluorescence microscopy via the environmental scanning electron microscope. The emission spectroscopy of the jet indicates that its plasma effluent carries an abundance of reactive atomic oxygen, providing catalyst for the observed plasma effect.
8. Synthesis of early transition metal and non-equilibrium intermetallic nanoparticles using n-butyllithium
Bondi, James F.
reacting Au nanoparticle seeds with n-butyllithium. The reaction yielded the thermodynamically stable phase Au3Li, a polar intermetallic which adopts the L12 structure type. Interestingly, the Au3Li nanoparticles decompose in water to regenerate Au. The Au3Li phase gives insight to a plausible template-driven reaction pathway for the non-equilibrium Au3M 1-x phases. The synthetic achievement of both non-equilibrium phases and polar intermetallics shows that n-butyllithium is capable of affecting nucleation kinetics and lithium intercalation. Finally, n-butyllithium was used as a strong reducing agent in the solution-based synthesis of elemental Mn nanoparticles. The particles were synthesized using air-free techniques by reacting n-butyllithium with MnCl2 and oleic acid in diphenyl ether. The nanoparticles were found to adopt the alpha-Mn structure and contained a thin amorphous MnO layer bound by oleate ligands to help render them air-stable. Unlike antiferromagnetic bulk Mn, the as-made nanoparticles were paramagnetic. With little modification, crystalline Mo and amorphous W nanoparticles were synthesized using the same n-butyllithium procedure. Using the thermal decomposition of metal-carbonyls was shown to yield W, Mo-based alloys, and tetrapod-like MnO nanoparticles.
NASA Technical Reports Server (NTRS)
Kruger, C. H.; Laux, C. O.
1998-01-01
Detailed measurements and modeling of the spectral emission of an atmospheric pressure air plasma at temperatures up to -3400 K have been made. The cold gas injected in the plasma torch contained an estimated mole fraction of water vapor of approximately 4.5 x 10(exp -3) and an estimated carbon dioxide mole fraction of approximately 3.3 x 10(exp -4). Under these conditions, the minimum level of air plasma emission is found to be between 3.9 and 4.15 microns. Outside this narrow region, significant spectral emission is detected that can be attributed to the fundamental and overtone bands of NO and OH, and to the v(sub 3) and the (v(sub 1)+v(sub 3)) bands Of CO2. Special attention was paid to the effects of ambient air absorption in the optical path between the plasma and the detector. Excellent quantitative agreement is obtained between the measured and simulated spectra, which are both on absolute intensity scales, thus lending confidence in the radiation models incorporated into NEQAIR2-IR over the course of this research program.
NASA Technical Reports Server (NTRS)
Kruger, C. H.; Laux, C. O.
1998-01-01
This report describes progress during the second year of our research program on Infrared Signature Masking by Air Plasmas at Stanford University. This program is intended to investigate the masking of infrared signatures by the air plasma formed behind the bow shock of high velocity missiles. Our previous annual report described spectral measurements and modeling of the radiation emitted between 3.2 and 5.5 microns by an atmospheric pressure air plasma in chemical and thermal equilibrium at a temperature of approximately 3100 K. One of our goals was to examine the spectral emission of secondary species such as water vapor or carbon dioxide. The cold air stream injected in the plasma torch contained approximately 330 parts per million Of CO2, which is the natural CO2 concentration in atmospheric air at room temperature, and a small amount of water vapor with an estimated mole fraction of 3.8 x 10(exp -4). As can be seen from Figure 1, it was found that the measured spectrum exhibited intense spectral features due to the fundamental rovibrational bands of NO at 4.9 - 5.5 microns and the V(3) band of CO2 (antisymmetric stretch) at 4.2-4.8 microns. These observations confirmed the well-known fact that infrared signatures between 4.15 - 5.5 microns can be masked by radiative emission in the interceptor's bow-shock. Figure I also suggested that the range 3.2 - 4.15 microns did not contain any significant emission features (lines or continuum) that could mask IR signatures. However, the signal-to-noise level, close to one in that range, precluded definite conclusions. Thus, in an effort to further investigate the spectral emission in the range of interest to signature masking problem, new measurements were made with a higher signal-to-noise ratio and an extended wavelength range.
11. The non-equilibrium nature of culinary evolution
Kinouchi, Osame; Diez-Garcia, Rosa W.; Holanda, Adriano J.; Zambianchi, Pedro; Roque, Antonio C.
2008-07-01
Food is an essential part of civilization, with a scope that ranges from the biological to the economic and cultural levels. Here, we study the statistics of ingredients and recipes taken from Brazilian, British, French and Medieval cookery books. We find universal distributions with scale invariant behaviour. We propose a copy-mutate process to model culinary evolution that fits our empirical data very well. We find a cultural 'founder effect' produced by the non-equilibrium dynamics of the model. Both the invariant and idiosyncratic aspects of culture are accounted for by our model, which may have applications in other kinds of evolutionary processes.
12. Shape characteristics of equilibrium and non-equilibrium fractal clusters.
PubMed
Mansfield, Marc L; Douglas, Jack F
2013-07-28
It is often difficult in practice to discriminate between equilibrium and non-equilibrium nanoparticle or colloidal-particle clusters that form through aggregation in gas or solution phases. Scattering studies often permit the determination of an apparent fractal dimension, but both equilibrium and non-equilibrium clusters in three dimensions frequently have fractal dimensions near 2, so that it is often not possible to discriminate on the basis of this geometrical property. A survey of the anisotropy of a wide variety of polymeric structures (linear and ring random and self-avoiding random walks, percolation clusters, lattice animals, diffusion-limited aggregates, and Eden clusters) based on the principal components of both the radius of gyration and electric polarizability tensor indicates, perhaps counter-intuitively, that self-similar equilibrium clusters tend to be intrinsically anisotropic at all sizes, while non-equilibrium processes such as diffusion-limited aggregation or Eden growth tend to be isotropic in the large-mass limit, providing a potential means of discriminating these clusters experimentally if anisotropy could be determined along with the fractal dimension. Equilibrium polymer structures, such as flexible polymer chains, are normally self-similar due to the existence of only a single relevant length scale, and are thus anisotropic at all length scales, while non-equilibrium polymer structures that grow irreversibly in time eventually become isotropic if there is no difference in the average growth rates in different directions. There is apparently no proof of these general trends and little theoretical insight into what controls the universal anisotropy in equilibrium polymer structures of various kinds. This is an obvious topic of theoretical investigation, as well as a matter of practical interest. To address this general problem, we consider two experimentally accessible ratios, one between the hydrodynamic and gyration radii, the other
13. Comment on the Article Relativistic Non-Equilibrium Thermodynamics Revisited''
Muschik, Wolfgang; von Borzeszkowski, Horst-Heino
2007-05-01
There are two problematic items in García-Colín and Sandoval-Villalbazo's approach to “relativistic non-equilibrium thermodynamics” (L.S. García- Colín and A. Sandoval-Villalbazo, J. Non-Equilib. Thermodyn. 31, 2006, pp. 11-22). The paper does not follow the fundamentals of relativity theory; according to them, the energy-momentum tensor (EMT) has to include all energies of the considered system. Secondly, strange thermodynamic consequences result by using the presuppositions made by the authors. The paper is critically discussed and some shortcomings are elucidated.
14. Energy flow in non-equilibrium conformal field theory
Bernard, Denis; Doyon, Benjamin
2012-09-01
We study the energy current and its fluctuations in quantum gapless 1d systems far from equilibrium modeled by conformal field theory, where two separated halves are prepared at distinct temperatures and glued together at a point contact. We prove that these systems converge towards steady states, and give a general description of such non-equilibrium steady states in terms of quantum field theory data. We compute the large deviation function, also called the full counting statistics, of energy transfer through the contact. These are universal and satisfy fluctuation relations. We provide a simple representation of these quantum fluctuations in terms of classical Poisson processes whose intensities are proportional to Boltzmann weights.
15. Shape characteristics of equilibrium and non-equilibrium fractal clusters.
PubMed
Mansfield, Marc L; Douglas, Jack F
2013-07-28
It is often difficult in practice to discriminate between equilibrium and non-equilibrium nanoparticle or colloidal-particle clusters that form through aggregation in gas or solution phases. Scattering studies often permit the determination of an apparent fractal dimension, but both equilibrium and non-equilibrium clusters in three dimensions frequently have fractal dimensions near 2, so that it is often not possible to discriminate on the basis of this geometrical property. A survey of the anisotropy of a wide variety of polymeric structures (linear and ring random and self-avoiding random walks, percolation clusters, lattice animals, diffusion-limited aggregates, and Eden clusters) based on the principal components of both the radius of gyration and electric polarizability tensor indicates, perhaps counter-intuitively, that self-similar equilibrium clusters tend to be intrinsically anisotropic at all sizes, while non-equilibrium processes such as diffusion-limited aggregation or Eden growth tend to be isotropic in the large-mass limit, providing a potential means of discriminating these clusters experimentally if anisotropy could be determined along with the fractal dimension. Equilibrium polymer structures, such as flexible polymer chains, are normally self-similar due to the existence of only a single relevant length scale, and are thus anisotropic at all length scales, while non-equilibrium polymer structures that grow irreversibly in time eventually become isotropic if there is no difference in the average growth rates in different directions. There is apparently no proof of these general trends and little theoretical insight into what controls the universal anisotropy in equilibrium polymer structures of various kinds. This is an obvious topic of theoretical investigation, as well as a matter of practical interest. To address this general problem, we consider two experimentally accessible ratios, one between the hydrodynamic and gyration radii, the other
16. Non Equilibrium Quantum Transport in a model of molecular conductor
Schiro', Marco; Fabrizio, Michele
2010-03-01
We investigate non equilibrium effects in quantum transport through a simple model of molecular conductor where a single electronic level coupled to a vibrational mode is hybridized with biased metallic contacts. Using a recently developed numerical method [1] we compute the time dependent current and extract steady state properties such as I-V characteristic, differential conductance and phonon distribution function. We also discuss transient effects and comment on the onset of bistability in the strong coupling regime. [4pt] [1] M. Schiro', M. Fabrizio, Phys.Rev.B 79 153302 (2009)
17. Shape characteristics of equilibrium and non-equilibrium fractal clusters
Mansfield, Marc L.; Douglas, Jack F.
2013-07-01
It is often difficult in practice to discriminate between equilibrium and non-equilibrium nanoparticle or colloidal-particle clusters that form through aggregation in gas or solution phases. Scattering studies often permit the determination of an apparent fractal dimension, but both equilibrium and non-equilibrium clusters in three dimensions frequently have fractal dimensions near 2, so that it is often not possible to discriminate on the basis of this geometrical property. A survey of the anisotropy of a wide variety of polymeric structures (linear and ring random and self-avoiding random walks, percolation clusters, lattice animals, diffusion-limited aggregates, and Eden clusters) based on the principal components of both the radius of gyration and electric polarizability tensor indicates, perhaps counter-intuitively, that self-similar equilibrium clusters tend to be intrinsically anisotropic at all sizes, while non-equilibrium processes such as diffusion-limited aggregation or Eden growth tend to be isotropic in the large-mass limit, providing a potential means of discriminating these clusters experimentally if anisotropy could be determined along with the fractal dimension. Equilibrium polymer structures, such as flexible polymer chains, are normally self-similar due to the existence of only a single relevant length scale, and are thus anisotropic at all length scales, while non-equilibrium polymer structures that grow irreversibly in time eventually become isotropic if there is no difference in the average growth rates in different directions. There is apparently no proof of these general trends and little theoretical insight into what controls the universal anisotropy in equilibrium polymer structures of various kinds. This is an obvious topic of theoretical investigation, as well as a matter of practical interest. To address this general problem, we consider two experimentally accessible ratios, one between the hydrodynamic and gyration radii, the other
18. Air Plasma Source for Biomedical Applications
Henriques, J.; Tatarova, E.; Dias, F. M.; Ferreira, C. M.; Gordiets, B.; IPFN-IST, 1049-001 LX, Portugal Team; Lebedev Physical Institute of the Russian Academy of Sciences Team
2011-10-01
Plasma interactions with living matter are presently at the frontiers of plasma research and development. Plasmas contain numerous agents that influence biological activity. They provide essentially two types of biocidal species: reactive species, such as oxygen atoms that lead to lethality of micro-organisms through erosion, and UV radiation that can damage the DNA strands. In this work we investigate a surface wave (2.45 GHz) driven discharge plasma in air, with a small admixture of water vapor, as a source of ground state O(3P) oxygen atoms, NO molecules and UV radiation. A theoretical model describing both the wave driven discharge zone and its flowing afterglow is used to analyze the performance of this plasma source. The predicted plasma-generated NO(X) and O(3P) concentrations and NO(γ) radiation intensity along the source are presented and discussed as a function of the microwave power and water vapor percentage in the gas mixture. To validate the theoretical predictions, the relative concentrations of species have been determined by Mass Spectrometry, Fourier Transform Infrared Spectroscopy and Optical Spectroscopy. Acknowledgment: This work was funded by the Portuguese Foundation for Science and Technology, under research contract PTDC/FIS/108411/2008.
19. Non-equilibrium hot carrier dynamics in plasmonic nanostructures
Narang, Prineha; Sundararaman, Ravishankar; Jermyn, Adam; Cortes, Emiliano; Maier, Stefan A.; Goddard, William A., III
Decay of surface plasmons to hot carriers is a new direction that has attracted considerable fundamental and application interest, yet a fundamental understanding of ultrafast plasmon decay processes and the underlying microscopic mechanisms remain incomplete. Ultrafast experiments provide insights into the relaxation of non-equilibrium carriers at the tens and hundreds of femtoseconds time scales, but do not yet directly probe shorter times with nanometer spatial resolution. Here we report the first ab initio calculations of non equilibrium transport of plasmonic hot carriers in metals and experimental observation of the injection of these carriers into molecules tethered to the metal surface. Specifically, metallic nanoantennas functionalized with a molecular monolayer allow for the direct probing of electron injection via surface enhanced Raman spectroscopy of the original and reduced molecular species. We combine first principles calculations of electron-electron and electron-phonon scattering rates with Boltzmann transport simulations to predict the ultrafast dynamics and transport of carriers in real materials. We also predict and compare the evolution of electron distributions in ultrafast experiments on noble metal nanoparticles.
20. Light-induced electronic non-equilibrium in plasmonic particles.
PubMed
Kornbluth, Mordechai; Nitzan, Abraham; Seideman, Tamar
2013-05-01
We consider the transient non-equilibrium electronic distribution that is created in a metal nanoparticle upon plasmon excitation. Following light absorption, the created plasmons decohere within a few femtoseconds, producing uncorrelated electron-hole pairs. The corresponding non-thermal electronic distribution evolves in response to the photo-exciting pulse and to subsequent relaxation processes. First, on the femtosecond timescale, the electronic subsystem relaxes to a Fermi-Dirac distribution characterized by an electronic temperature. Next, within picoseconds, thermalization with the underlying lattice phonons leads to a hot particle in internal equilibrium that subsequently equilibrates with the environment. Here we focus on the early stage of this multistep relaxation process, and on the properties of the ensuing non-equilibrium electronic distribution. We consider the form of this distribution as derived from the balance between the optical absorption and the subsequent relaxation processes, and discuss its implication for (a) heating of illuminated plasmonic particles, (b) the possibility to optically induce current in junctions, and (c) the prospect for experimental observation of such light-driven transport phenomena. PMID:23656152
1. Non-equilibrium theory of arrested spinodal decomposition
SciTech Connect
Olais-Govea, José Manuel; López-Flores, Leticia; Medina-Noyola, Magdaleno
2015-11-07
The non-equilibrium self-consistent generalized Langevin equation theory of irreversible relaxation [P. E. Ramŕez-González and M. Medina-Noyola, Phys. Rev. E 82, 061503 (2010); 82, 061504 (2010)] is applied to the description of the non-equilibrium processes involved in the spinodal decomposition of suddenly and deeply quenched simple liquids. For model liquids with hard-sphere plus attractive (Yukawa or square well) pair potential, the theory predicts that the spinodal curve, besides being the threshold of the thermodynamic stability of homogeneous states, is also the borderline between the regions of ergodic and non-ergodic homogeneous states. It also predicts that the high-density liquid-glass transition line, whose high-temperature limit corresponds to the well-known hard-sphere glass transition, at lower temperature intersects the spinodal curve and continues inside the spinodal region as a glass-glass transition line. Within the region bounded from below by this low-temperature glass-glass transition and from above by the spinodal dynamic arrest line, we can recognize two distinct domains with qualitatively different temperature dependence of various physical properties. We interpret these two domains as corresponding to full gas-liquid phase separation conditions and to the formation of physical gels by arrested spinodal decomposition. The resulting theoretical scenario is consistent with the corresponding experimental observations in a specific colloidal model system.
2. Non-equilibrium magnetic interactions in strongly correlated systems
SciTech Connect
Secchi, A.; Brener, S.; Lichtenstein, A.I.; Katsnelson, M.I.
2013-06-15
We formulate a low-energy theory for the magnetic interactions between electrons in the multi-band Hubbard model under non-equilibrium conditions determined by an external time-dependent electric field which simulates laser-induced spin dynamics. We derive expressions for dynamical exchange parameters in terms of non-equilibrium electronic Green functions and self-energies, which can be computed, e.g., with the methods of time-dependent dynamical mean-field theory. Moreover, we find that a correct description of the system requires, in addition to exchange, a new kind of magnetic interaction, that we name twist exchange, which formally resembles Dzyaloshinskii–Moriya coupling, but is not due to spin–orbit, and is actually due to an effective three-spin interaction. Our theory allows the evaluation of the related time-dependent parameters as well. -- Highlights: •We develop a theory for magnetism of strongly correlated systems out of equilibrium. •Our theory is suitable for laser-induced ultrafast magnetization dynamics. •We write time-dependent exchange parameters in terms of electronic Green functions. •We find a new magnetic interaction, a “twist exchange”. •We give general expressions for magnetic noise in itinerant-electron systems.
3. Non-equilibrium theory of arrested spinodal decomposition.
PubMed
Olais-Govea, José Manuel; López-Flores, Leticia; Medina-Noyola, Magdaleno
2015-11-01
The non-equilibrium self-consistent generalized Langevin equation theory of irreversible relaxation [P. E. Ramŕez-González and M. Medina-Noyola, Phys. Rev. E 82, 061503 (2010); 82, 061504 (2010)] is applied to the description of the non-equilibrium processes involved in the spinodal decomposition of suddenly and deeply quenched simple liquids. For model liquids with hard-sphere plus attractive (Yukawa or square well) pair potential, the theory predicts that the spinodal curve, besides being the threshold of the thermodynamic stability of homogeneous states, is also the borderline between the regions of ergodic and non-ergodic homogeneous states. It also predicts that the high-density liquid-glass transition line, whose high-temperature limit corresponds to the well-known hard-sphere glass transition, at lower temperature intersects the spinodal curve and continues inside the spinodal region as a glass-glass transition line. Within the region bounded from below by this low-temperature glass-glass transition and from above by the spinodal dynamic arrest line, we can recognize two distinct domains with qualitatively different temperature dependence of various physical properties. We interpret these two domains as corresponding to full gas-liquid phase separation conditions and to the formation of physical gels by arrested spinodal decomposition. The resulting theoretical scenario is consistent with the corresponding experimental observations in a specific colloidal model system. PMID:26547174
4. Non-Equilibrium Critical Behavior: An Extended Irreversible Thermodynamics Approach
Hernández-Lemus, Enrique; García-Colín, Leopoldo S.
2006-11-01
Critical phenomena in non-equilibrium systems have been studied by means of a wide variety of theoretical and experimental approaches. Mode-coupling, renormalization group, complex Lie algebras and diagrammatic techniques are some of the usual theoretical tools. Experimental studies include light and inelastic neutron scattering, X-ray photon correlation spectroscopy, microwave interferometry and several other techniques. Nevertheless, no conclusive treatment has been developed from the basic principles of a thermodynamic theory of irreversible processes. We have developed a formalism in which we obtain correlation functions as field averages of the associated functions. By applying such formalism, we attempt to find out whether the resulting correlation functions will inherit the mathematical properties (integrability, generalized homogeneity, scaling laws) of its parent potentials, and we also use these correlation functions to study the behavior of macroscopic systems far from equilibrium, especially in the neighborhood of critical points or dynamic phase transitions. As a working example, we will consider the mono-critical behavior of a non-equilibrium binary fluid mixture close to its consolute point.
5. The non-equilibrium and energetic cost of sensory adaptation
SciTech Connect
Lan, G.; Sartori, Pablo; Tu, Y.
2011-03-24
6. The non-equilibrium and energetic cost of sensory adaptation
Lan, G.; Sartori, Pablo; Tu, Y.
2011-03-01
7. Non-equilibrium thermodynamics analysis of transcriptional regulation kinetics
Hernández-Lemus, Enrique; Tovar, Hugo; Mejía, Carmen
2014-12-01
Gene expression in eukaryotic cells is an extremely complex and interesting phenomenon whose dynamics are controlled by a large number of subtle physicochemical processes commonly described by means of gene regulatory networks. Such networks consist in a series of coupled chemical reactions, conformational changes, and other biomolecular processes involving the interaction of the DNA molecule itself with a number of proteins usually called transcription factors as well as enzymes and other components. The kinetics behind the functioning of such gene regulatory networks are largely unknown, though its description in terms of non-equilibrium thermodynamics has been discussed recently. In this work we will derive general kinetic equations for a gene regulatory network from a non-equilibrium thermodynamical description and discuss its use in understanding the free energy constrains imposed in the network structure. We also will discuss explicit expressions for the kinetics of a simple model of gene regulation and show that the kinetic role of mRNA decay during the RNA synthesis stage (or transcription) is somehow limited due to the comparatively low values of decay rates. At the level discussed here, this implies a decoupling of the kinetics of mRNA synthesis and degradation a fact that may become quite useful when modeling gene regulatory networks from experimental data on whole genome gene expression.
8. C-Field Methods for Non-Equilibrium Bose Gases
Davis, Matthew J.; Wright, Tod M.; Blakie, P. Blair; Bradley, Ashton S.; Ballagh, Rob J.; Gardiner, Crispin W.
2013-02-01
We review c-field methods for simulating the non-equilibrium dynamics of degenerate Bose gases beyond the mean-field Gross-Pitaevskii approximation. We describe three separate approaches that utilise similar numerical methods, but have distinct regimes of validity. Systems at finite temperature can be treated with either the closed-system projected Gross-Pitaevskii equation (PGPE), or the open-system stochastic projected Gross-Pitaevskii equation (SPGPE). These are both applicable in quantum degenerate regimes in which thermal fluctuations are significant. At low or zero temperature, the truncated Wigner projected Gross Pitaevskii equation (TWPGPE) allows for the simulation of systems in which spontaneous collision processes seeded by quantum fluctuations are important. We describe the regimes of validity of each of these methods, and discuss their relationships to one another, and to other simulation techniques for the dynamics of Bose gases. The utility of the SPGPE formalism in modelling non-equilibrium Bose gases is illustrated by its application to the dynamics of spontaneous vortex formation in the growth of a Bose-Einstein condensate.
9. Modeling of non-equilibrium phenomena in expanding flows by means of a collisional-radiative model
SciTech Connect
Munafò, A.; Lani, A.; Bultel, A.; Panesi, M.
2013-07-15
The effects of non-equilibrium in a quasi-one-dimensional nozzle flow are investigated by means of a collisional-radiative model. The gas undergoing the expansion is an air plasma and consists of atoms, molecules, and free electrons. In the present analysis, the electronic excited states of atomic and molecular species are treated as separate pseudo-species. Rotational and vibrational energy modes are assumed to be populated according to Boltzmann distributions. The coupling between radiation and gas dynamics is accounted for, in simplified manner, by using escape factors. The flow governing equations for the steady quasi-one-dimensional flow are written in conservative form and discretized in space by means of a finite volume method. Steady-state solutions are obtained by using a fully implicit time integration scheme. The analysis of the evolution of the electronic distribution functions reveals a substantial over-population of the high-lying excited levels of atoms and molecules in correspondence of the nozzle exit. The influence of optical thickness is also studied. The results clearly demonstrate that the radiative transitions, within the optically thin approximation, drastically reduce the over-population of high-lying electronic levels.
10. Air plasma jet with hollow electrodes at atmospheric pressure
SciTech Connect
Hong, Yong Cheol; Uhm, Han Sup
2007-05-15
Atmospheric-pressure plasma jet with air is produced through hollow electrodes and dielectric with a hole of 1 mm diam. The plasma jet device is operated by injecting pressurized air into the electrode hole. The air plasma jet device at average powers less than 5 W exhibits a cold plasma jet of about 2 cm in length and near the room temperature, being low enough to treat thermally sensitive materials. Preliminary studies on the discharge characteristics and application tests are also presented by comparing the air plasma jet with the nitrogen and argon plasma jet.
11. Non-equilibrium phase transitions in a liquid crystal
Dan, K.; Roy, M.; Datta, A.
2015-09-01
The present manuscript describes kinetic behaviour of the glass transition and non-equilibrium features of the "Nematic-Isotropic" (N-I) phase transition of a well known liquid crystalline material N-(4-methoxybenzylidene)-4-butylaniline from the effects of heating rate and initial temperature on the transitions, through differential scanning calorimetry (DSC), Fourier transform infrared and fluorescence spectroscopy. Around the vicinity of the glass transition temperature (Tg), while only a change in the baseline of the ΔCp vs T curve is observed for heating rate (β) > 5 K min-1, consistent with a glass transition, a clear peak for β ≤ 5 K min-1 and the rapid reduction in the ΔCp value from the former to the latter rate correspond to an order-disorder transition and a transition from ergodic to non-ergodic behaviour. The ln β vs 1000/T curve for the glass transition shows convex Arrhenius behaviour that can be explained very well by a purely entropic activation barrier [Dan et al., Eur. Phys. Lett. 108, 36007 (2014)]. Fourier transform infrared spectroscopy indicates sudden freezing of the out-of-plane distortion vibrations of the benzene rings around the glass transition temperature and a considerable red shift indicating enhanced coplanarity of the benzene rings and, consequently, enhancement in the molecular ordering compared to room temperature. We further provide a direct experimental evidence of the non-equilibrium nature of the N-I transition through the dependence of this transition temperature (TNI) and associated enthalpy change (ΔH) on the initial temperature (at fixed β-values) for the DSC scans. A plausible qualitative explanation based on Mesquita's extension of Landau-deGennes theory [O. N. de Mesquita, Braz. J. Phys. 28, 257 (1998)] has been put forward. The change in the molecular ordering from nematic to isotropic phase has been investigated through fluorescence anisotropy measurements where the order parameter, quantified by the
12. Non-equilibrium phase transitions in a liquid crystal.
PubMed
Dan, K; Roy, M; Datta, A
2015-09-01
The present manuscript describes kinetic behaviour of the glass transition and non-equilibrium features of the "Nematic-Isotropic" (N-I) phase transition of a well known liquid crystalline material N-(4-methoxybenzylidene)-4-butylaniline from the effects of heating rate and initial temperature on the transitions, through differential scanning calorimetry (DSC), Fourier transform infrared and fluorescence spectroscopy. Around the vicinity of the glass transition temperature (Tg), while only a change in the baseline of the ΔCp vs T curve is observed for heating rate (β) > 5 K min(-1), consistent with a glass transition, a clear peak for β ≤ 5 K min(-1) and the rapid reduction in the ΔCp value from the former to the latter rate correspond to an order-disorder transition and a transition from ergodic to non-ergodic behaviour. The ln β vs 1000/T curve for the glass transition shows convex Arrhenius behaviour that can be explained very well by a purely entropic activation barrier [Dan et al., Eur. Phys. Lett. 108, 36007 (2014)]. Fourier transform infrared spectroscopy indicates sudden freezing of the out-of-plane distortion vibrations of the benzene rings around the glass transition temperature and a considerable red shift indicating enhanced coplanarity of the benzene rings and, consequently, enhancement in the molecular ordering compared to room temperature. We further provide a direct experimental evidence of the non-equilibrium nature of the N-I transition through the dependence of this transition temperature (TNI) and associated enthalpy change (ΔH) on the initial temperature (at fixed β-values) for the DSC scans. A plausible qualitative explanation based on Mesquita's extension of Landau-deGennes theory [O. N. de Mesquita, Braz. J. Phys. 28, 257 (1998)] has been put forward. The change in the molecular ordering from nematic to isotropic phase has been investigated through fluorescence anisotropy measurements where the order parameter, quantified by the
13. Biological Implications of Dynamical Phases in Non-equilibrium Networks
Murugan, Arvind; Vaikuntanathan, Suriyanarayanan
2016-03-01
Biology achieves novel functions like error correction, ultra-sensitivity and accurate concentration measurement at the expense of free energy through Maxwell Demon-like mechanisms. The design principles and free energy trade-offs have been studied for a variety of such mechanisms. In this review, we emphasize a perspective based on dynamical phases that can explain commonalities shared by these mechanisms. Dynamical phases are defined by typical trajectories executed by non-equilibrium systems in the space of internal states. We find that coexistence of dynamical phases can have dramatic consequences for function vs free energy cost trade-offs. Dynamical phases can also provide an intuitive picture of the design principles behind such biological Maxwell Demons.
14. Non-Equilibrium Hyperbolic Transport in Transcriptional Regulation
PubMed Central
Hernández-Lemus, Enrique; Correa-Rodríguez, María D.
2011-01-01
In this work we studied memory and irreversible transport phenomena in a non-equilibrium thermodynamical model for genomic transcriptional regulation. Transcriptional regulation possess an extremely complex phenomenology, and it is, of course, of foremost importance in organismal cell development and in the pathogenesis of complex diseases. A better understanding of the way in which these processes occur is mandatory to optimize the construction of gene regulatory networks, but also to connect these networks with multi-scale phenomena (e.g. metabolism, signalling pathways, etc.) under an integrative Systems Biology-like vision. In this paper we analyzed three simple mechanisms of genetic stimulation: an instant pulse, a periodic biochemical signal and a saturation process with sigmoidal kinetics and from these we derived the system's thermodynamical response, in the form of, for example, anomalous transcriptional bursts. PMID:21754990
15. Thermal Non-equilibrium Consistent with Widespread Cooling
NASA Technical Reports Server (NTRS)
Winebarger, A.; Lionello, R.; Mikic, Z.; Linker, J.; Mok, Y.
2014-01-01
Time correlation analysis has been used to show widespread cooling in the solar corona; this cooling has been interpreted as a result of impulsive (nanoflare) heating. In this work, we investigate wide-spread cooling using a 3D model for a solar active region which has been heated with highly stratified heating. This type of heating drives thermal non-equilibrium solutions, meaning that though the heating is effectively steady, the density and temperature in the solution are not. We simulate the expected observations in narrowband EUV images and apply the time correlation analysis. We find that the results of this analysis are qualitatively similar to the observed data. We discuss additional diagnostics that may be applied to differentiate between these two heating scenarios.
16. Complementary relations in non-equilibrium stochastic processes
Kim, Eun-jin; Nicholson, S. B.
2015-08-01
We present novel complementary relations in non-equilibrium stochastic processes. Specifically, by utilising path integral formulation, we derive statistical measures (entropy, information, and work) and investigate their dependence on variables (x, v), reference frames, and time. In particular, we show that the equilibrium state maximises the simultaneous information quantified by the product of the Fisher information based on x and v while minimising the simultaneous disorder/uncertainty quantified by the sum of the entropy based on x and v as well as by the product of the variances of the PDFs of x and v. We also elucidate the difference between Eulerian and Lagrangian entropy. Our theory naturally leads to Hamilton-Jacobi relation for forced-dissipative systems.
17. Non-equilibrium Thermodynamics of the Longitudinal Spin Seebeck Effect
Basso, Vittorio; Ferraro, Elena; Sola, Alessandro; Magni, Alessandro; Kuepferling, Michaela; Pasquale, Massimo
In this paper we employ non equilibrium thermodynamics of fluxes and forces to describe magnetization and heat transport. By the theory we are able to identify the thermodynamic driving force of the magnetization current as the gradient of the effective field ▿H*. This definition permits to define the spin Seebeck coefficient ɛM which relates ▿H* and the temperature gradient ▿T. By applying the theory to the geometry of the longitudinal spin Seebeck effect we are able to obtain the optimal conditions for generating large magnetization currents. Furthermore, by using the results of recent experiments, we obtain an order of magnitude for the value of ɛM ∼ 10-2 TK-1 for yttrium iron garnet (Y3Fe5O12).
18. Closure conditions for non-equilibrium multi-component models
Müller, S.; Hantke, M.; Richter, P.
2016-07-01
A class of non-equilibrium models for compressible multi-component fluids in multi-dimensions is investigated taking into account viscosity and heat conduction. These models are subject to the choice of interfacial pressures and interfacial velocity as well as relaxation terms for velocity, pressure, temperature and chemical potentials. Sufficient conditions are derived for these quantities that ensure meaningful physical properties such as a non-negative entropy production, thermodynamical stability, Galilean invariance and mathematical properties such as hyperbolicity, subcharacteristic property and existence of an entropy-entropy flux pair. For the relaxation of chemical potentials, a two-component and a three-component models for vapor-water and gas-water-vapor, respectively, are considered.
19. Modeling Inflation Using a Non-Equilibrium Equation of Exchange
NASA Technical Reports Server (NTRS)
Chamberlain, Robert G.
2013-01-01
Inflation is a change in the prices of goods that takes place without changes in the actual values of those goods. The Equation of Exchange, formulated clearly in a seminal paper by Irving Fisher in 1911, establishes an equilibrium relationship between the price index P (also known as "inflation"), the economy's aggregate output Q (also known as "the real gross domestic product"), the amount of money available for spending M (also known as "the money supply"), and the rate at which money is reused V (also known as "the velocity of circulation of money"). This paper offers first a qualitative discussion of what can cause these factors to change and how those causes might be controlled, then develops a quantitative model of inflation based on a non-equilibrium version of the Equation of Exchange. Causal relationships are different from equations in that the effects of changes in the causal variables take time to play out-often significant amounts of time. In the model described here, wages track prices, but only after a distributed lag. Prices change whenever the money supply, aggregate output, or the velocity of circulation of money change, but only after a distributed lag. Similarly, the money supply depends on the supplies of domestic and foreign money, which depend on the monetary base and a variety of foreign transactions, respectively. The spreading of delays mitigates the shocks of sudden changes to important inputs, but the most important aspect of this model is that delays, which often have dramatic consequences in dynamic systems, are explicitly incorporated.macroeconomics, inflation, equation of exchange, non-equilibrium, Athena Project
20. Non-Equilibrium Phenomena in High Power Beam Materials Processing
Tosto, Sebastiano
2004-03-01
The paper concerns some aspects of non-equilibrium materials processing with high power beams. Three examples show that the formation of metastable phases plays a crucial role to understand the effects of beam-matter interaction: (i) modeling of pulsed laser induced thermal sputtering; (ii) formation of metastable phases during solidification of the melt pool; (i) possibility of carrying out heat treatments by low power irradiation in situ''. The case (i) deals with surface evaporation and boiling processes in presence of superheating. A computer simulation model of thermal sputtering by vapor bubble nucleation in molten phase shows that non-equilibrium processing enables the rise of large surface temperature gradients in the boiling layer and the possibility of sub-surface temperature maximum. The case (ii) concerns the heterogeneous welding of Cu and AISI 304L stainless steel plates by electron beam irradiation. Microstructural investigation of the molten zone has shown that dwell times of the order of 10-1-10-3 s, consistent with moderate cooling rates in the range 10^3-10^5 K/s, entail the formation of metastable Cu-Fe phases. The case (iii) concerns electron beam welding and post-welding treatments of 2219 Al base alloy. Electron microscopy and positron annihilation have explained why post-weld heat transients induced by low power irradiation of specimens in the as welded condition enable ageing effects usually expected after some hours of treatment in furnace. The problem of microstructural instability is particularly significant for a correct design of components manufactured with high power beam technologies and subjected to severe acceptance standards to ensure advanced performances during service life.
1. Non-equilibrium dynamics of glass-forming liquid mixtures
Sánchez-Díaz, Luis Enrique; Lázaro-Lázaro, Edilio; Olais-Govea, José Manuel; Medina-Noyola, Magdaleno
2014-06-01
The non-equilibrium self-consistent generalized Langevin equation theory of irreversible processes in glass-forming liquids [P. Ramírez-González and M. Medina-Noyola, Phys. Rev. E 82, 061503 (2010)] is extended here to multi-component systems. The resulting theory describes the statistical properties of the instantaneous local particle concentration profiles nα(r, t) of species α in terms of the coupled time-evolution equations for the mean value overline{n}_α ({r},t) and for the covariance σ _{α β }({r},{r}^' };t)equiv overline{δ n_α ({r},t)δ n_β ({r}^' },t)} of the fluctuations δ n_α ({r},t) = n_α ({r},t)- overline{n}_α ({r},t). As in the monocomponent case, these two coarse-grained equations involve a local mobility function bα(r, t) for each species, written in terms of the memory function of the two-time correlation function C_{α β }({r},{r}^' };t,t^' }) equiv overline{δ n_α ({r},t)δ n_β ({r}^' },t^' })}. If the system is constrained to remain spatially uniform and subjected to a non-equilibrium preparation protocol described by a given temperature and composition change program T(t) and overline{n}_α (t), these equations predict the irreversible structural relaxation of the partial static structure factors Sαβ(k; t) and of the (collective and self) intermediate scattering functions Fαβ(k, τ; t) and F^S_{α β }(k,τ ;t). We illustrate the applicability of the resulting theory with two examples involving simple model mixtures subjected to an instantaneous temperature quench: an electroneutral binary mixture of equally sized and oppositely charged hard-spheres, and a binary mixture of soft-spheres of moderate size-asymmetry.
2. Effects of non-equilibrium particle distributions in deuterium-tritium burning
SciTech Connect
Michta, D; Graziani, F; Pruet, J; Luu, T
2009-08-18
We investigate the effects of non-equilibrium particle distributions resulting from rapid deuterium-tritium burning in plasmas using a Fokker-Planck code that incorporates small-angle Coulomb scattering, Brehmsstrahlung, Compton scattering, and thermal-nuclear burning. We find that in inertial confinement fusion environments, deviations away from Maxwellian distributions for either deuterium or tritium ions are small and result in 1% changes in the energy production rates. The deuterium and tritium effective temperatures are not equal, but differ by only about 2.5% near the time of peak burn rate. Simulations with high Z (Xe) dopants show that the dopant temperature closely tracks that of the fuel. On the other hand, fusion product ion distributions are highly non-Maxwellian, and careful treatments of energy-exchange between these ions and other particles is important for determining burn rates.
3. Numerical Analysis on Thermal Non-Equilibrium Process of Laser-Supported Detonation Wave in Axisymmetric Nozzle
SciTech Connect
Shiraishi, Hiroyuki
2008-04-28
Numerical Analyses on Laser-Supported Plasma (LSP) have been performed for researching the mechanism of laser absorption occurring in the laser propulsion system. Above all, Laser-Supported Detonation (LSD), categorized as one type of LSP, is considered as one of the most important phenomena because it can generate high pressure and high temperature for performing highly effective propulsion. For simulating generation and propagation of LSD wave, I have performed thermal non-equilibrium analyses by Navier-stokes equations, using a CO{sub 2} gasdynamic laser into an inert gas, where the most important laser absorption mechanism for LSD propagation is Inverse Bremsstrahlung. As a numerical method, TVD scheme taken into account of real gas effects and thermal non-equilibrium effects by using a 2-temperature model, is applied. In this study, I analyze a LSD wave propagating through a conical nozzle, where an inner space of an actual laser propulsion system is simplified.
4. Surface Wave Driven Air-Water Plasmas
Tatarova, Elena; Henriques, Julio; Ferreira, Carlos
2013-09-01
The performance of a surface wave driven air-water plasma source operating at atmospheric pressure and 2.45 GHz has been analyzed. A 1D model has been developed in order to describe in detail the creation and loss processes of active species of interest and to provide a complete characterization of the axial structure of the source, including the discharge and the afterglow zones. The main electron creation channel was found to be the associative ionization process N +O -->NO+ + e. The NO(X) relative density in the afterglow plasma jet ranges from 1.2% to 1.6% depending on power and water percentage according to the model predictions and the measurements. Other types of species such as NO2 and nitrous acid HNO2 have also been detected by mass and FT-IR spectroscopy. Furthermore, high densities of O2(a1Δg) singlet delta oxygen molecules and OH radicals (1% and 5%, respectively) can be achieved in the discharge zone. In the late afterglow the O2(a1Δg) density is about 0.1% of the total density. The plasma source has a flexible operation and potential for channeling the energy in ways that maximize the density of active species of interest. This study was funded by the Foundation for Science and Technology, Portuguese Ministry of Education and Science, under the research contract PTDC/FIS/108411/2008.
5. Picosecond CARS measurements of nitrogen vibrational loading and rotational/translational temperature in non-equilibrium discharges
Montello, A.; Yin, Z.; Burnette, D.; Adamovich, I. V.; Lempert, W. R.
2013-11-01
Picosecond coherent anti-Stokes Raman spectroscopy (CARS) is used to study vibrational energy loading and relaxation kinetics in nitrogen and air ns pulsed non-equilibrium plasmas, in both plane-to-plane and pin-to-pin geometries. In 10 kHz repetitively pulsed plane-to-plane plasmas, up to ˜50% of coupled discharge power is found to load vibrations, in good agreement with a master equation kinetic model. In the pin-to-pin geometry, ˜40% of total discharge energy in a single pulse in air at 100 Torr is found to couple directly to nitrogen vibrations by electron impact, also in good agreement with model predictions. Post-discharge, the total quanta in vibrational levels v = 0-9 is found to increase by ˜60% in air and by a factor of ˜3 in nitrogen, respectively, a result in direct contrast to modelling results which predict the total number of quanta to be essentially constant until ultimately decaying by V-T relaxation and mass diffusion. More detailed comparison between experiment and model show that the vibrational distribution function (VDF) predicted by the model during, and directly after, the discharge pulse is in good agreement with that determined experimentally. However, for time delays exceeding ˜1 µs, the experimental VDF shows populations of vibrational levels v ⩾ 2 greatly exceeding modelling results, which predict their predominant decay due to net downward V-V transfer and corresponding increase in v = 1 population. This is at variance with the experimental results, which show a significant monotonic increase in the populations of levels v = 2-9 at t ˜ 1-10 µs after the discharge pulse, both in nitrogen and air, before gradually switching to relaxation at t ˜ 10-100 µs. It is concluded that a collisional process is likely feeding high vibrational levels at a rate which is comparable to the rate at which population of the high levels is lost due to net downward V-V energy transfer. A likely candidate for the source of additional vibrational
6. Observing Organic Molecules in Interstellar Gases: Non Equilibrium Excitation.
Wiesenfeld, Laurent; Faure, Alexandre; Remijan, Anthony; Szalewicz, Krzysztof
2014-06-01
In order to observe quantitatively organic molecules in interstellar gas, it is necessary to understand the relative importance of photonic and collisional excitations. In order to do so, collisional excitation transfer rates have to be computed. We undertook several such studies, in particular for H_2CO and HCOOCH_3. Both species are observed in many astrochemical environments, including star-forming regions. We found that those two molecules behave in their low-lying rotational levels in an opposite way. For cis methyl-formate, a non-equilibrium radiative transfer treatment of rotational lines is performed, using a new set of theoretical collisional rate coefficients. These coefficients have been computed in the temperature range 5 to 30 K by combining coupled-channel scattering calculations with a high accuracy potential energy surface for HCOOCH_3 -- He. The results are compared to observations toward the Sagittarius B2(N) molecular cloud. A total of 2080 low-lying transitions of methyl formate, with upper levels below 25 K, were treated. These lines are found to probe a cold (30 K), moderately dense (n ˜ 104 cm-3) interstellar gas. In addition, our calculations indicate that all detected emission lines with a frequency below 30 GHz are collisionally pumped weak masers amplifying the background of Sgr B2(N). This result demonstrates the generality of the inversion mechanism for the low-lying transitions of methyl formate. For formaldehyde, we performed a similar non-equilibrium treatment, with H_2 as the collisional partner, thanks to the accurate H_2CO - H_2 potential energy surface . We found very different energy transfer rates for collisions with para-H_2 (J=0) and ortho-H_2 (J=1). The well-known absorption against the cosmological background of the 111→ 101 line is shown to depend critically on the difference of behaviour between para and ortho-H_2, for a wide range of H_2 density. We thank the CNRS-PCMI French national program for continuous support
7. Non-equilibrium Aspects of Quantum Integrable Systems
Andrei, Natan
The study of non-equilibrium dynamics of interacting many body systems is currently one of the main challenges of modern condensed matter physics, driven by the spectacular progress in the ability to create experimental systems - trapped cold atomic gases are a prime example - that can be isolated from their environment and be highly controlled. Many old and new questions can be addressed: thermalization of isolated systems, nonequilibrium steady states, the interplay between non equilibrium currents and strong correlations, quantum phase transitions in time, universality among others. In this talk I will describe nonequilibrium quench dynamics in integrable quantum systems. I'll discuss the time evolution of the Lieb-Liniger system, a gas of interacting bosons moving on the continuous infinite line and interacting via a short range potential. Considering a finite number of bosons on the line we find that for any value of repulsive coupling the system asymptotes towards a strongly repulsive gas for any initial state, while for an attractive coupling, the system forms a maximal bound state that dominates at longer times. In the thermodynamic limit -with the number of bosons and the system size sent to infinity at a constant density and the long time limit taken subsequently- I'll show that the density and density-density correlation functions for strong but finite positive coupling are described by GGE for translationally invariant initial states with short range correlations. As examples I'll discuss quenches from a Mott insulator initial state or a Newton's Cradle. Then I will show that if the initial state is strongly non translational invariant, e.g. a domain wall configuration, the system does not equilibrate but evolves into a nonequilibrium steady state (NESS). A related NESS arises when the quench consists of coupling a quantum dot to two leads held at different chemical potential, leading in the long time limit to a steady state current. Time permitting I
8. Air plasma jet with hollow electrodes at atmospheric pressure
Hong, Yong Cheol; Uhm, Han Sup
2007-05-01
Atmospheric-pressure plasma jet with air is produced through hollow electrodes and dielectric with a hole of 5W exhibits a cold plasma jet of about 2cm in length and near the room temperature, being low enough to treat thermally sensitive materials. Preliminary studies on the discharge characteristics and application tests are also presented by comparing the air plasma jet with the nitrogen and argon plasma jet.
9. Non-equilibrium control of complex solids by nonlinear phononics
Mankowsky, Roman; Först, Michael; Cavalleri, Andrea
2016-06-01
We review some recent advances in the use of optical fields at terahertz frequencies to drive the lattice of complex materials. We will focus on the control of low energy collective properties of solids, which emerge on average when a high frequency vibration is driven and a new crystal structure induced. We first discuss the fundamentals of these lattice rearrangements, based on how anharmonic mode coupling transforms an oscillatory motion into a quasi-static deformation of the crystal structure. We then discuss experiments, in which selectively changing a bond angle turns an insulator into a metal, accompanied by changes in charge, orbital and magnetic order. We then address the case of light induced non-equilibrium superconductivity, a mysterious phenomenon observed in some cuprates and molecular materials when certain lattice vibrations are driven. Finally, we show that the dynamics of electronic and magnetic phase transitions in complex-oxide heterostructures follow distinctly new physical pathways in case of the resonant excitation of a substrate vibrational mode.
10. Non-Equilibrium Water-Glassy Polymer Dynamics
Davis, Eric; Minelli, Matteo; Baschetti, Marco; Sarti, Giulio; Elabd, Yossef
2012-02-01
For many applications (e.g., medical implants, packaging), an accurate assessment and fundamental understanding of the dynamics of water-glassy polymer interactions is of great interest. In this study, sorption and diffusion of pure water in several glassy polymers films, such as poly(styrene) (PS), poly(methyl methacrylate) (PMMA), poly(lactide) (PLA), were measured over a wide range of vapor activities and temperatures using several experimental techniques, including quartz spring microbalance (QSM), quartz crystal microbalance (QCM), and time-resolved Fourier transform infrared-attenuated total reflectance (FTIR-ATR) spectroscopy. Non-Fickian behavior (diffusion-relaxation phenomena) was observed by all three techniques, while FTIR-ATR spectroscopy also provides information about the distribution of the states of water and water transport mechanisms on a molecular-level. Specifically, the states of water are significantly different in PS compared to PMMA and PLA. Additionally, a purely predictive non-equilibrium lattice fluid (NELF) model was applied to predict the sorption isotherms of water in these glassy polymers.
11. Non-Equilibrium Turbulence and Two-Equation Modeling
NASA Technical Reports Server (NTRS)
Rubinstein, Robert
2011-01-01
Two-equation turbulence models are analyzed from the perspective of spectral closure theories. Kolmogorov theory provides useful information for models, but it is limited to equilibrium conditions in which the energy spectrum has relaxed to a steady state consistent with the forcing at large scales; it does not describe transient evolution between such states. Transient evolution is necessarily through nonequilibrium states, which can only be found from a theory of turbulence evolution, such as one provided by a spectral closure. When the departure from equilibrium is small, perturbation theory can be used to approximate the evolution by a two-equation model. The perturbation theory also gives explicit conditions under which this model can be valid, and when it will fail. Implications of the non-equilibrium corrections for the classic Tennekes-Lumley balance in the dissipation rate equation are drawn: it is possible to establish both the cancellation of the leading order Re1/2 divergent contributions to vortex stretching and enstrophy destruction, and the existence of a nonzero difference which is finite in the limit of infinite Reynolds number.
12. A probability theory for non-equilibrium gravitational systems
Peñarrubia, Jorge
2015-08-01
This paper uses dynamical invariants to describe the evolution of collisionless systems subject to time-dependent gravitational forces without resorting to maximum-entropy probabilities. We show that collisionless relaxation can be viewed as a special type of diffusion process in the integral-of-motion space. In time-varying potentials with a fixed spatial symmetry the diffusion coefficients are closely related to virial quantities, such as the specific moment of inertia, the virial factor and the mean kinetic and potential energy of microcanonical particle ensembles. The non-equilibrium distribution function is found by convolving the initial distribution function with the Green function that solves Einstein's equation for freely diffusing particles. Such a convolution also yields a natural solution to the Fokker-Planck equations in the energy space. Our mathematical formalism can be generalized to potentials with a time-varying symmetry, where diffusion extends over multiple dimensions of the integral-of-motion space. The new probability theory is in many ways analogous to stochastic calculus, with two significant differences: (i) the equations of motion that govern the trajectories of particles are fully deterministic, and (ii) the diffusion coefficients can be derived self-consistently from microcanonical phase-space averages without relying on ergodicity assumptions. For illustration we follow the cold collapse of N-body models in a time-dependent logarithmic potential. Comparison between the analytical and numerical results shows excellent agreement in regions where the potential evolution does not depart too strongly from the adiabatic regime.
13. Non-equilibrium Transport in Carbon based Adsorbate Systems
Fürst, Joachim; Brandbyge, Mads; Stokbro, Kurt; Jauho, Antti-Pekka
2007-03-01
We have used the Atomistix Tool Kit(ATK) and TranSIESTA[1] packages to investigate adsorption of iron atoms on a graphene sheet. The technique of both codes is based on density functional theory using local basis sets[2], and non-equilibrium Green's functions (NEGF) to calculate the charge distribution under external bias. Spin dependent electronic structure calculations are performed for different iron coverages. These reveal adsorption site dependent charge transfer from iron to graphene leading to screening effects. Transport calculations show spin dependent scattering of the transmission which is analysed obtaining the transmission eigenchannels for each spin type. The phenomena of electromigration of iron in these systems at finite bias will be discussed, estimating the so-called wind force from the reflection[3]. [1] M. Brandbyge, J.-L. Mozos, P. Ordejon, J. Taylor, and K. Stokbro. Physical Review B (Condensed Matter and Materials Physics), 65(16):165401/11-7, 2002. [2] Jose M. Soler, Emilio Artacho, Julian D. Gale, Alberto Garcia, Javier Junquera, Pablo Ordejon, and Daniel Sanchez-Portal. Journal of Physics Condensed Matter, 14(11):2745-2779, 2002. [3] Sorbello. Theory of electromigration. Solid State Physics, 1997.
14. Non-Equilibrium Properties from Equilibrium Free Energy Calculations
NASA Technical Reports Server (NTRS)
Pohorille, Andrew; Wilson, Michael A.
2012-01-01
Calculating free energy in computer simulations is of central importance in statistical mechanics of condensed media and its applications to chemistry and biology not only because it is the most comprehensive and informative quantity that characterizes the eqUilibrium state, but also because it often provides an efficient route to access dynamic and kinetic properties of a system. Most of applications of equilibrium free energy calculations to non-equilibrium processes rely on a description in which a molecule or an ion diffuses in the potential of mean force. In general case this description is a simplification, but it might be satisfactorily accurate in many instances of practical interest. This hypothesis has been tested in the example of the electrodiffusion equation . Conductance of model ion channels has been calculated directly through counting the number of ion crossing events observed during long molecular dynamics simulations and has been compared with the conductance obtained from solving the generalized Nernst-Plank equation. It has been shown that under relatively modest conditions the agreement between these two approaches is excellent, thus demonstrating the assumptions underlying the diffusion equation are fulfilled. Under these conditions the electrodiffusion equation provides an efficient approach to calculating the full voltage-current dependence routinely measured in electrophysiological experiments.
15. NON-EQUILIBRIUM IONIZATION IN THE BIFROST STELLAR ATMOSPHERE CODE
SciTech Connect
Olluri, K.; Gudiksen, B. V.; Hansteen, V. H.
2013-03-15
The chromosphere and transition region have for the last 20 years been known to be quite dynamic layers of the solar atmosphere, characterized by timescales shorter than the ionization equilibrium timescales of many of the ions dominating emission in these regions. Due to the fast changes in the properties of the atmosphere, long ionization and recombination times can lead these ions to being found far from their equilibrium temperatures. A number of the spectral lines that we observe can therefore not be expected a priori to reflect information about local quantities such as the density or temperature, and interpreting observations requires numerical modeling. Modeling the ionization balance is computationally expensive and has earlier only been done in one dimension. However, one-dimensional models can primarily be used to investigate the possible importance of a physical effect, but cannot verify or disprove the importance of that effect in the fully three-dimensional solar atmosphere. Here, using the atomic database package DIPER, we extend one-dimensional methods and implement a solver for the rate equations of the full three-dimensional problem, using the numerical code Bifrost. We present our implementation and report on a few test cases. We also report on studies of the important C IV and Fe XII ions in a semi-realistic two-dimensional solar atmosphere model, focusing on differences between statistical equilibrium and non-equilibrium ionization results.
16. Non-equilibrium Warm Dense Gold: Experiments and Simulations
Ng, Andrew
2015-11-01
This talk is an overview of a series of studies of non-equilibrium Warm Dense Matter using a broad range of measured properties of a single material, namely Au, as comprehensive benchmarks for theory. The measurements are made in fs-laser pump-probe experiments. For understanding lattice stability, our investigation reveals a solid phase at high energy density. This leads to the calculation of lattice dynamics using MD simulations and phonon hardening in DFT-MD simulations. For understanding electron transport in two-temperature states, AC conductivity is used to evaluate DFT-MD and Kubo-Greenwood calculations while DC conductivity is used to test Ziman calculations in a DFT average atom model. The electron density is also used to assess electronic structure calculations in DFT simulations. In our latest study of electron kinetics in states with a non-Fermi-Dirac distribution, three-body recombination is found to have a significant effect on electron thermalizaiton time. This is driving an effort to develop electron kinetics simulations using the Boltzmann equation method.
17. New non-equilibrium matrix imbibition equation for double porosity model
Konyukhov, Andrey; Pankratov, Leonid
2016-07-01
The paper deals with the global Kondaurov double porosity model describing a non-equilibrium two-phase immiscible flow in fractured-porous reservoirs when non-equilibrium phenomena occur in the matrix blocks, only. In a mathematically rigorous way, we show that the homogenized model can be represented by usual equations of two-phase incompressible immiscible flow, except for the addition of two source terms calculated by a solution to a local problem being a boundary value problem for a non-equilibrium imbibition equation given in terms of the real saturation and a non-equilibrium parameter.
18. New Simulator for Non-Equilibrium Modeling of Hydrate Reservoirs
Kvamme, B.; Qorbani Nashaqi, K.; Jemai, K.; Vafaei, M.
2014-12-01
Due to Gibbs phase rule and combination of first and second law of thermodynamics, hydrate in nature cannot be in equilibrium since they come from different parent phases. In this system hydrate formation and dissociation is affected by local variables such as pressure, temperature and composition with mass and energy transport restrictions. Available simulators have attempted to model hydrate phase transition as an equilibrium reaction. Although those which treated the processes of formation and dissociation as kinetics used model of Kim and Bishnoi based on laboratory PVT experiment, and consequently hard to accept up scaling to real reservoirs condition. Additionally, they merely check equilibrium in terms of pressure and temperature projections and disregard thermodynamic requirements for equilibrium especially along axes of concentrations in phases. Non-equilibrium analysis of hydrate involves putting aside all the phase transitions which are not possible and use kinetic evaluation to measure phase transitions progress in each grid block for each time step. This procedure is Similar to geochemical reservoir simulators logic. As a result RetrasoCodeBright has been chosen as hydrate reservoir simulator and our work involves extension of this code. RetrasoCodeBright (RCB) is able to handle competing processes of formation and dissociation of hydrates as pseudo reactions at each node and each time step according to the temperature, pressure and concentration. Hydrates can therefore be implemented into the structure as pseudo minerals, with appropriate kinetic models. In order to implement competing nature of phase transition kinetics of hydrate formation, we use classical nucleation theory based on Kvamme et al. as a simplified model inside RCB and use advanced theories to fit parameters for the model (PFT). Hydrate formation and dissociation can directly be observed through porosity changes in the specific areas of the porous media. In this work which is in
19. Step-wise pulling protocols for non-equilibrium dynamics
Ngo, Van Anh
The fundamental laws of thermodynamics and statistical mechanics, and the deeper understandings of quantum mechanics have been rebuilt in recent years. It is partly because of the increasing power of computing resources nowadays, that allow shedding direct insights into the connections among the thermodynamics laws, statistical nature of our world, and the concepts of quantum mechanics, which have not yet been understood. But mostly, the most important reason, also the ultimate goal, is to understand the mechanisms, statistics and dynamics of biological systems, whose prevailing non-equilibrium processes violate the fundamental laws of thermodynamics, deviate from statistical mechanics, and finally complicate quantum effects. I believe that investigations of the fundamental laws of non-equilibrium dynamics will be a frontier research for at least several more decades. One of the fundamental laws was first discovered in 1997 by Jarzynski, so-called Jarzynski's Equality. Since then, different proofs, alternative descriptions of Jarzynski's Equality, and its further developments and applications have been quickly accumulated. My understandings, developments and applications of an alternative theory on Jarzynski's Equality form the bulk of this dissertation. The core of my theory is based on stepwise pulling protocols, which provide deeper insight into how fluctuations of reaction coordinates contribute to free-energy changes along a reaction pathway. We find that the most optimal pathways, having the largest contribution to free-energy changes, follow the principle of detailed balance. This is a glimpse of why the principle of detailed balance appears so powerful for sampling the most probable statistics of events. In a further development on Jarzynski's Equality, I have been trying to use it in the formalism of diagonal entropy to propose a way to extract useful thermodynamic quantities such temperature, work and free-energy profiles from far
20. PREFACE: International Symposium on Non-Equilibrium Soft Matter 2010 International Symposium on Non-Equilibrium Soft Matter 2010
Kawakatsu, T.; Matsuyama, A.; Ohta, T.; Tanaka, H.; Tanaka, S.
2011-07-01
Soft matter is a rapidly growing interdisciplinary research field covering a range of subject areas including physics, chemistry, biology, mathematics and engineering. Some of the important universal features of these materials are their mesoscopic structures and their dynamics. Due to the existence of such large-scale structures, which nevertheless exhibit interactions of the order of the thermal energy, soft matter can readily be taken out of equilibrium by imposing a weak external field such as an electric field, a mechanical stress or a shear flow. The importance of the coexistence of microscopic molecular dynamics and the mesoscopic/macroscopic structures and flows requires us to develop hierarchical approaches to understand the nonlinear and nonequilibrium phenomena, which is one of the central issues of current soft matter research. This special section presents selected contributions from the 'International Symposium on Non-Equilibrium Soft Matter 2010' held from 17-20 August 2010 in Nara, Japan, which aimed to describe recent advances in soft matter research focusing especially on its nonequilibrium aspects. The topics discussed cover statics and dynamics of a wide variety of materials ranging from traditional soft matter like polymers, gels, emulsions, liquid crystals and colloids to biomaterials such as biopolymers and biomembranes. Among these studies, we highlighted the physics of biomembranes and vesicles, which has attracted great attention during the last decade; we organized a special session for this active field. The work presented in this issue deals with (1) structure formation in biomembranes and vesicles, (2) rheology of polymers and gels, (3) mesophases in block copolymers, (4) mesoscopic structures in liquid crystals and ionic liquids, and (5) nonequilibrium dynamics. This symposium was organized as part of a research project supported by the Grant-in-Aid for the priority area 'Soft Matter Physics' (2006-2010) from the Ministry of Education
1. PREFACE: International Symposium on Non-Equilibrium Soft Matter 2010 International Symposium on Non-Equilibrium Soft Matter 2010
Kawakatsu, T.; Matsuyama, A.; Ohta, T.; Tanaka, H.; Tanaka, S.
2011-07-01
Soft matter is a rapidly growing interdisciplinary research field covering a range of subject areas including physics, chemistry, biology, mathematics and engineering. Some of the important universal features of these materials are their mesoscopic structures and their dynamics. Due to the existence of such large-scale structures, which nevertheless exhibit interactions of the order of the thermal energy, soft matter can readily be taken out of equilibrium by imposing a weak external field such as an electric field, a mechanical stress or a shear flow. The importance of the coexistence of microscopic molecular dynamics and the mesoscopic/macroscopic structures and flows requires us to develop hierarchical approaches to understand the nonlinear and nonequilibrium phenomena, which is one of the central issues of current soft matter research. This special section presents selected contributions from the 'International Symposium on Non-Equilibrium Soft Matter 2010' held from 17-20 August 2010 in Nara, Japan, which aimed to describe recent advances in soft matter research focusing especially on its nonequilibrium aspects. The topics discussed cover statics and dynamics of a wide variety of materials ranging from traditional soft matter like polymers, gels, emulsions, liquid crystals and colloids to biomaterials such as biopolymers and biomembranes. Among these studies, we highlighted the physics of biomembranes and vesicles, which has attracted great attention during the last decade; we organized a special session for this active field. The work presented in this issue deals with (1) structure formation in biomembranes and vesicles, (2) rheology of polymers and gels, (3) mesophases in block copolymers, (4) mesoscopic structures in liquid crystals and ionic liquids, and (5) nonequilibrium dynamics. This symposium was organized as part of a research project supported by the Grant-in-Aid for the priority area 'Soft Matter Physics' (2006-2010) from the Ministry of Education
2. Atomistic Simulation of Non-Equilibrium Phenomena in Hypersonic Flows
Norman, Paul Erik
The goal of this work is to model the heterogeneous recombination of atomic oxygen on silica surfaces, which is of interest for accurately predicting the heating on vehicles traveling at hypersonic speeds. This is accomplished by creating a finite rate catalytic model, which describes recombination with a set of elementary gas-surface reactions. Fundamental to a description of surface catalytic reactions are the in situ chemical structures on the surface where recombination can occur. Using molecular dynamics simulations with the Reax GSISiO potential, we find that the chemical sites active in direct gas-phase reactions on silica surfaces consist of a small number of specific structures (or defects). The existence of these defects on real silica surfaces is supported by experimental results and the structure and energetics of these defects have been verified with quantum chemical calculations. The reactions in the finite rate catalytic model are based on the interaction of molecular and atomic oxygen with these defects. Trajectory calculations are used to find the parameters in the forward rate equations, while a combination of detailed balance and transition state theory are used to find the parameters in the reverse rate equations. The rate model predicts that the oxygen recombination coefficient is relatively constant at T (300-1000 K), in agreement with experimental results. At T > 1000 K the rate model predicts a drop off in the oxygen recombination coefficient, in disagreement with experimental results, which predict that the oxygen recombination coefficient increases with temperature. A discussion of the possible reasons for this disagreement, including non-adiabatic collision dynamics, variable surface site concentrations, and additional recombination mechanisms is presented. This thesis also describes atomistic simulations with Classical Trajectory Calculation Direction Simulation Monte Carlo (CTC-DSMC), a particle based method for modeling non-equilibrium
3. Optical emission spectroscopy characterizations of micro-air plasma used for simulation of cell membrane poration
Zerrouki, A.; Motomura, H.; Ikeda, Y.; Jinno, M.; Yousfi, M.
2016-07-01
A micro-air corona discharge, which is one of the plasmas successfully used for gene transfection in terms of high transfection and cell viability rates, is characterized by optical emission spectroscopy. This non-equilibrium low temperature plasma is generated from the tip of a pulsed high voltage micro-tube (0.2 mm inner diameter and 0.7 mm for outer diameter) placed 2 mm in front of a petri dish containing deionized water and set on a grounded copper plate. The electron temperature, equal to about 6.75 eV near the electrode tip and decreased down to 3.4 eV near the plate, has been estimated, with an error bar of about 30%, from an interesting approach based on the experimental ratio of the closest nitrogen emission spectra of \\text{N}2+ (FNS) at 391.4 nm and N2(SPS) at 394.3 nm. This is based on one hand on a balance equation between creations and losses of the excited upper levels of these two UV spectra and on the other hand on the electron impact rates of the creation of these upper levels calculated from solution of the multi-term Boltzmann equation. Then using the measured Hα spectrum, electron density n e has been estimated from Stark broadening versus the inter-electrode position with an average error bar of about 50%. n e ≈ 1 × 1015 cm-3 is near the tip coherent with the usual magnitude of electron density in the streamer head developed near the tip of the corona discharges. Rotational temperatures, estimated from comparison of synthetic and experimental spectra of OH(A - X), \\text{N}2+ (FNS) at 391.4 nm, and N2(SPS) at 337 nm are respectively equal to 2350 K, 2000 K and 700 K in the gap space. This clearly underlines a thermal non-equilibrium of the corresponding excited species generated inside the thin streamer filaments. But, due to the high dilution of these species in the background gas, these high rotational temperatures do not affect the mean gas temperature that remains close to 300
4. Optical emission spectroscopy characterizations of micro-air plasma used for simulation of cell membrane poration
Zerrouki, A.; Motomura, H.; Ikeda, Y.; Jinno, M.; Yousfi, M.
2016-07-01
A micro-air corona discharge, which is one of the plasmas successfully used for gene transfection in terms of high transfection and cell viability rates, is characterized by optical emission spectroscopy. This non-equilibrium low temperature plasma is generated from the tip of a pulsed high voltage micro-tube (0.2 mm inner diameter and 0.7 mm for outer diameter) placed 2 mm in front of a petri dish containing deionized water and set on a grounded copper plate. The electron temperature, equal to about 6.75 eV near the electrode tip and decreased down to 3.4 eV near the plate, has been estimated, with an error bar of about 30%, from an interesting approach based on the experimental ratio of the closest nitrogen emission spectra of \\text{N}2+ (FNS) at 391.4 nm and N2(SPS) at 394.3 nm. This is based on one hand on a balance equation between creations and losses of the excited upper levels of these two UV spectra and on the other hand on the electron impact rates of the creation of these upper levels calculated from solution of the multi-term Boltzmann equation. Then using the measured Hα spectrum, electron density n e has been estimated from Stark broadening versus the inter-electrode position with an average error bar of about 50%. n e ≈ 1 × 1015 cm‑3 is near the tip coherent with the usual magnitude of electron density in the streamer head developed near the tip of the corona discharges. Rotational temperatures, estimated from comparison of synthetic and experimental spectra of OH(A ‑ X), \\text{N}2+ (FNS) at 391.4 nm, and N2(SPS) at 337 nm are respectively equal to 2350 K, 2000 K and 700 K in the gap space. This clearly underlines a thermal non-equilibrium of the corresponding excited species generated inside the thin streamer filaments. But, due to the high dilution of these species in the background gas, these high rotational temperatures do not affect the mean gas temperature that remains close to 300
5. Chemical equilibrium and non-equilibrium inviscid flow computations using a centered scheme
Vos, J. B.; Bergman, C. M.
Within the framework of the collaboration between IMHEF and CERFACS a 2D Inviscid Flow solver for Hypersonic flows has been developed. The Euler equations are discretized in space on a structured mesh using the Finite Volume method with centered differences. The resulting system of ordinary differential equations is integrated in time using the explicit Runge Kutta scheme. Artificial dissipation terms are added to damp odd/even oscillations allowed for by centered space differences, and to damp spurious oscillations near discontinuities. External shock waves in the flow field are treated by a shock fitting procedure, while (weaker) internal shock waves are captured by the numerical scheme. A complete description of the numerical method can be found in [1]. The strong shock waves present in hypersonic flows give rise to high temperatures directly behind the shock wave, which may result into the dissociation of air. This is a process which costs energy, hence temperatures in the flow field will be reduced. Air dissociation can be modelled on different levels, which depend on the ratio of the characteristic time scales of the flow and the chemistry. If the characteristic time scale of the chemistry is much smaller than that of the flow, it can be assumed that the flow is in chemical equilibrium, i.e. chemical reactions are taking place, but the production of a chemical species is balanced by its destruction. The other limit is that the chemistry time scale is much smaller than that of the flow, hence no chemical reactions are taking place. The chemistry is frozen, and the air is treated as a thermally perfect gas. If the time scales are of the same order of magnitude the flow is in chemical non-equilibrium. These three levels of modelling have been included in the Euler solver. Incorporation of equilibrium and frozen chemistry is straightforward for the centered scheme described above, since only the relation which connects the pressure to the density and total energy
6. Potential and Flux Field Landscape Theory of Spatially Inhomogeneous Non-Equilibrium Systems
Wu, Wei
In this dissertation we establish a potential and flux field landscape theory for studying the global stability and dynamics as well as the non-equilibrium thermodynamics of spatially inhomogeneous non-equilibrium dynamical systems. The potential and flux landscape theory developed previously for spatially homogeneous non-equilibrium stochastic systems described by Langevin and Fokker-Planck equations is refined and further extended to spatially inhomogeneous non-equilibrium stochastic systems described by functional Langevin and Fokker-Planck equations. The probability flux field is found to be crucial in breaking detailed balance and characterizing non-equilibrium effects of spatially inhomogeneous systems. It also plays a pivotal role in governing the global dynamics and formulating a set of non-equilibrium thermodynamic equations for a generic class of spatially inhomogeneous stochastic systems. The general formalism is illustrated by studying more specific systems and processes, such as the reaction diffusion system, the Ornstein-Uhlenbeck process, the Brusselator reaction diffusion model, and the spatial stochastic neuronal model. The theory can be applied to a variety of physical, chemical and biological spatially inhomogeneous non-equilibrium systems abundant in nature.
7. Terahertz generation in multiple laser-induced air plasmas
SciTech Connect
Chen, M.-K.; Kim, Jae Hun; Yang, C.-E.; Yin, Stuart Shizhuo; Hui Rongqing; Ruffin, Paul
2008-12-08
An investigation of the terahertz wave generation in multiple laser-induced air plasmas is presented. First, it is demonstrated that the intensity of the terahertz wave increases as the number of air plasmas increases. Second, the physical mechanism of this enhancement effect of the terahertz generation is studied by quantitatively measuring the intensity of the generated terahertz wave as a function of phase difference between adjacent air plasmas. It is found out that the superposition is the main mechanism to cause this enhancement. Thus, the results obtained in this paper not only provide a technique to generate stronger terahertz wave but also enable a better understanding of the mechanism of the terahertz generation in air plasma.
8. Radiofrequency plasma antenna generated by femtosecond laser filaments in air
SciTech Connect
Brelet, Y.; Houard, A.; Point, G.; Prade, B.; Carbonnel, J.; Andre, Y.-B.; Mysyrowicz, A.; Arantchouk, L.; Pellet, M.
2012-12-24
We demonstrate tunable radiofrequency emission from a meter-long linear plasma column produced in air at atmospheric pressure. A short-lived plasma column is initially produced by femtosecond filamentation and subsequently converted into a long-lived discharge column by application of an external high voltage field. Radiofrequency excitation is fed to the plasma by induction and detected remotely as electromagnetic radiation by a classical antenna.
9. Effect of glow discharge air plasma on grain crops seed
SciTech Connect
Dubinov, A.E.; Lazarenko, E.M.; Selemir, V.D.
2000-02-01
Oat and barley seeds have been exposed to both continuous and pulsed glow discharge plasmas in air to investigate the effects on germination and sprout growth. Statistical analysis was used to evaluate the effect of plasma exposure on the percentage germination and length of sprout growth. A stimulating effect of plasma exposure was found together with a strong dependence on whether continuous or pulsed discharges were used.
10. Microwave air plasmas in capillaries at low pressure II. Experimental investigation
Stancu, G. D.; Leroy, O.; Coche, P.; Gadonna, K.; Guerra, V.; Minea, T.; Alves, L. L.
2016-11-01
This work presents an experimental study of microwave (2.45 GHz excitation frequency) micro-plasmas, generated in dry air (N2 80%: O2 20%) within a small radius silica capillary (345 µm inner radius) at low pressure (300 Pa) and low powers (80–130 W). Experimental diagnostics are performed using optical emission spectroscopy calibrated in absolute intensity. Axial-resolved measurements (50 µm spatial resolution) of atomic transitions N(3p4S) → N(3s4P) O(3p5P) → O(3s5S) and molecular transitions N2(C,v‧) → N2(B,v″) \\text{N}2+ (B,v‧) → \\text{N}2+ (X,v″) allow us to obtain, as a function of the coupled power, the absolute densities of N(3p4S), O(3p5P), N2(C), N2(B) and \\text{N}2+ (B), as well as the gas (rotational) temperature (700–1000 K), the vibrational temperature of N2(C,v) (7000–10 000 K) and the excitation temperatures of N2(C) and N2(B) (11 000 K). The analysis of the H β line-width gives an upper limiting value of 1013 cm‑3 for the electron density; its axial variation (4 × 1011–6 × 1012 cm‑3) being estimated by solving the wave electrodynamics equations for the present geometry, plasma length and electron–neutral collision frequency. The experimental results were compared with the results from a 0D model, presented in companion paper I [1], which couples the system of rate balance equations for the dominant neutral and charged plasma species to the homogeneous two-term electron Boltzmann equation, taking the measured gas temperature and the estimated electron density as input parameters. Good qualitative agreement is found between the measurements and calculations of the local species densities for various powers and axial positions. The dissociation degree of oxygen is found above 10%. Moreover, both the measurements and calculations show evidence of the non-equilibrium behavior of low-temperature plasmas, with vibrational and excitation
11. Quantification of air plasma chemistry for surface disinfection
Pavlovich, Matthew J.; Clark, Douglas S.; Graves, David B.
2014-12-01
Atmospheric-pressure air plasmas, created by a variety of discharges, are promising sources of reactive species for the emerging field of plasma biotechnology because of their convenience and ability to operate at ambient conditions. One biological application of ambient-air plasma is microbial disinfection, and the ability of air plasmas to decontaminate both solid surfaces and liquid volumes has been thoroughly established in the literature. However, the mechanism of disinfection and which reactive species most strongly correlate with antimicrobial effects are still not well understood. We describe quantitative gas-phase measurements of plasma chemistry via infrared spectroscopy in confined volumes, focusing on air plasma generated via surface micro-discharge (SMD). Previously, it has been shown that gaseous chemistry is highly sensitive to operating conditions, and the measurements we describe here extend those findings. We quantify the gaseous concentrations of ozone (O3) and nitrogen oxides (NO and NO2, or NOx) throughout the established ‘regimes’ for SMD air plasma chemistry: the low-power, ozone-dominated mode; the high-power, nitrogen oxides-dominated mode; and the intermediate, unstable transition region. The results presented here are in good agreement with previously published experimental studies of aqueous chemistry and parameterized models of gaseous chemistry. The principal finding of the present study is the correlation of bacterial inactivation on dry surfaces with gaseous chemistry across these time and power regimes. Bacterial decontamination is most effective in ‘NOx mode’ and less effective in ‘ozone mode’, with the weakest antibacterial effects in the transition region. Our results underscore the dynamic nature of air plasma chemistry and the importance of careful chemical characterization of plasma devices intended for biological applications.
12. Dynamic relaxation of a levitated nanoparticle from a non-equilibrium steady state.
PubMed
Gieseler, Jan; Quidant, Romain; Dellago, Christoph; Novotny, Lukas
2014-05-01
Fluctuation theorems are a generalization of thermodynamics on small scales and provide the tools to characterize the fluctuations of thermodynamic quantities in non-equilibrium nanoscale systems. They are particularly important for understanding irreversibility and the second law in fundamental chemical and biological processes that are actively driven, thus operating far from thermal equilibrium. Here, we apply the framework of fluctuation theorems to investigate the important case of a system relaxing from a non-equilibrium state towards equilibrium. Using a vacuum-trapped nanoparticle, we demonstrate experimentally the validity of a fluctuation theorem for the relative entropy change occurring during relaxation from a non-equilibrium steady state. The platform established here allows non-equilibrium fluctuation theorems to be studied experimentally for arbitrary steady states and can be extended to investigate quantum fluctuation theorems as well as systems that do not obey detailed balance.
13. Non-equilibrium Steady States in Kac's Model Coupled to a Thermostat
Evans, Josephine
2016-09-01
This paper studies the existence, uniqueness and convergence to non-equilibrium steady states in Kac's model with an external coupling. We work in both Fourier distances and Wasserstein distances. Our methods work in the case where the external coupling is not a Maxwellian equilibrium. This provides an example of a non-equilibrium steady state. We also study the behaviour as the number of particles goes to infinity and show quantitative estimates on the convergence rate of the first marginal.
14. Non-equilibrium phenomena and molecular reaction dynamics: mode space, energy space and conformer space
Glowacki, David R.; Lightfoot, Robert; Harvey, Jeremy N.
2013-03-01
The ability to characterise and control matter far away from equilibrium is a frontier challenge facing modern science. In this article, we sketch out a heuristic structure for thinking about the different ways in which non-equilibrium phenomena can impact molecular reaction dynamics. Our analytical schema includes three different regimes, organised according to increasing dynamical resolution: at the lowest resolution, we have conformer phase space, at an intermediate resolution, we have energy space; and at the highest resolution, we have mode space. Within each regime, we discuss practical definitions of non-equilibrium phenomena, mostly in terms of the corresponding relaxation timescales. Using this analytical framework, we discuss some recent non-equilibrium reaction dynamics studies spanning isolated small-molecule ensembles, gas-phase ensembles and solution-phase ensembles. This includes new results that provide insight into how non-equilibrium phenomena impact the solution-phase alkene-hydroboration reaction. We emphasise that interesting non-equilibrium dynamical phenomena often occur when the relaxation timescales characterising each regime are similar. In closing, we reflect on outstanding challenges and future research directions to guide our understanding of how non-equilibrium phenomena impact reaction dynamics.
15. Thermal And Chemical Non-Equilibrium Effects In The Wake Of A Boundary-Layer Sized Object In Hypersonic Flows
Birrer, Marcel; Stemmer, Christian; Adams, Nikolaus N.
2011-05-01
Investigations of hypersonic boundary-layer flows around a cubical obstacle with a height in the order of half the boundary layer thickness were carried out in this work. Special interest was laid on the influence of chemical non-equilibrium effects on the wake flow of the obstacle. Direct numerical simulations were conducted using three different gas models, a caloric perfect, an equilibrium and a chemical non-equilibrium gas model. The geometry was chosen as a wedge with a six degree half angle, according to the aborted NASA HyBoLT free flight experiment. At 0.5 m downstream of the leading edge, a surface trip was positioned. The free-stream flow was set to Mach 8.5 with air conditions taken from the 1976 standard atmosphere at an altitude of 42 km according to the predicted flight path. The simulations were done in three steps for all models. First, two-dimensional calculations of the whole configuration including the leading edge and the obstacle were conducted. These provide constant span-wise profiles for detailed, steady three-dimensional simulations around the close vicinity of the obstacle. A free-stream Mach number of about 6.3 occurs behind the shock. A cross-section in the wake of the object then delivers the steady inflow for detailed unsteady simulations of the wake. Perturbations at unstable frequencies, obtained from a bi-global secondary stability analysis, were added to these profiles. The solutions are time-Fourier transformed to investigate the unsteady downstream development of the different modes due to the interaction with the base-flow containing two counter-rotating vortices. Results will be presented that show the influence of the presence of chemical non-equilibrium on the instability in the wake of the object leading to a laminar or a turbulent wake.
16. Spectral Modeling in Astrophysics - The Physics of Non-equilibrium Clouds
Ferland, Gary; Williams, Robin
2016-02-01
Collisional-radiative spectral modeling plays a central role in astrophysics, probing phenomena ranging from the chemical evolution of the Universe to the energy production near supermassive black holes in distant quasars. The observed emission lines form in non-equilibrium clouds that have very low densities by laboratory standards, and are powered by energy sources which themselves are not in equilibrium. The spectrum is the result of a large number of microphysical processes, thermal statistics often do not apply, and analytical theory cannot be used. Numerical simulations are used to understand the physical state and the resulting spectrum. The greatest distinction between astrophysical modeling and conventional plasma simulations lies in the range of phenomena that must be considered. A single astronomical object will often have gas with kinetic temperatures of T˜10^6 K, 10^4 K, and T≤ 10^3 K, with the physical state ranging from molecular to fully ionized, and emitting over all wavelengths between the radio and x-ray. Besides atomic, plasma, and chemical physics, condensed matter physics is important because of the presence of small solid grains' which affect the gas through catalytic reactions and the infrared emission they produce. The ionization, level populations, chemistry, and grain properties must be determined self-consistently, along with the radiation transport, to predict the observed spectrum. Although the challenge is great, so are the rewards. Numerical spectral simulations allow us to read the message contained in the spectrum emitted by objects far from the Earth that existed long ago.
17. Plasma Medicine
Laroussi, M.; Kong, M. G.; Morfill, G.; Stolz, W.
2012-05-01
Foreword R. Satava and R. J. Barker; Part I. Introduction to Non-equilibrium Plasma, Cell Biology, and Contamination: 1. Introduction M. Laroussi; 2. Fundamentals of non-equilibrium plasmas M. Kushner and M. Kong; 3. Non-equilibrium plasma sources M. Laroussi and M. Kong; 4. Basic cell biology L. Greene and G. Shama; 5. Contamination G. Shama and B. Ahlfeld; Part II. Plasma Biology and Plasma Medicine: 6. Common healthcare challenges G. Isbary and W. Stolz; 7. Plasma decontamination of surfaces M. Kong and M. Laroussi; 8. Plasma decontamination of gases and liquids A. Fridman; 9. Plasma-cell interaction: prokaryotes M. Laroussi and M. Kong; 10. Plasma-cell interaction: eukaryotes G. Isbary, G. Morfill and W. Stolz; 11. Plasma based wound healing G. Isbary, G. Morfill and W. Stolz; 12. Plasma ablation, surgery, and dental applications K. Stalder, J. Woloszko, S. Kalghatgi, G. McCombs, M. Darby and M. Laroussi; Index.
18. Air-Plasma Bullets Propagating Inside Microcapillaries and in Ambient Air
Lacoste, Deanna A.; Bourdon, Anne; Kuribara, Koichi; Urabe, Keiichiro; Stauss, Sven; Terashima, Kazuo
2014-10-01
We report on the characterization of air-plasma bullets formed inside microcapillary tubes and in ambient air, obtained without the use of inert or noble gases. The bullets are produced by nanosecond discharges, applied at 1 kHz in a dielectric barrier discharge configuration. The anode consists of a tungsten wire with a 50- μm diameter, centered in the microcapillary, while the cathode is a silver ring, fixed on the outer surface of the fused silica tube. The gap distance is kept constant at 1.35 mm. The microcapillary is fed with a 4-sccm flow of air at atmospheric pressure. In the tubes and in ambient air, the propagation of air plasma bullets is observed. The temporal evolution of the bullet propagation has been studied with the aid of an ICCD camera. The effect of the applied voltage (from 5.2 to 8.2 kV) and the inner diameter of the microcapillaries (from 100 to 500 μm) on the discharge dynamics are investigated. Inside the tubes, while the topology of the bullets seems to be strongly dependent on the diameter, their velocity (on the order of 1 to 5 ×105 ms-1) is only a function of the applied voltage. In ambient air, the air-plasma bullets propagate at a velocity of 1 . 25 ×105 ms-1. Possible mechanisms for the propagation of air-plasma bullets in ambient air are discussed.
19. Dynamic field sampling of airborne organophosphate triesters using solid-phase microextraction under equilibrium and non-equilibrium conditions.
PubMed
Isetun, Sindra; Nilsson, Ulrika
2005-01-01
A simple setup for dynamic air sampling using a solid-phase microextraction (SPME) device designed for use in the field was evaluated for organophosphate triester vapour under both equilibrium and non-equilibrium conditions. The effects of varying the applied airflows in the sampling device were evaluated in order to optimise the system with respect to the Reynolds number and magnitude of the boundary layer that developed near the surface. Further, the storage stability of the analytes was studied for both capped and uncapped 100-microm PDMS fibres. Organophosphate triesters are utilized on large scales as flame-retardants and/or plasticizers, for instance in upholstered furniture. In indoor working environments these compounds have become common components in the surrounding air. Measurements were performed in a recently furnished working environment and the concentration of tris(2-choropropyl) phosphate was found to be 7 microg m(-3).
20. Analysis of processes in DC arc plasma torches for spraying that use air as plasma forming gas
Frolov, V.; Ivanov, D.; Toropchin, A.
2014-11-01
Developed in Saint Petersburg State Polytechnical University technological processes of air-plasma spraying of wear-resistant, regenerating, hardening and decorative coatings used in number of industrial areas are described. The article contains examples of applications of air plasma spraying of coatings as well as results of mathematical modelling of processes in air plasma torches for spraying.
1. Non-equilibrium Helium Ionization in an MHD Simulation of the Solar Atmosphere
Golding, Thomas Peter; Leenaarts, Jorrit; Carlsson, Mats
2016-02-01
The ionization state of the gas in the dynamic solar chromosphere can depart strongly from the instantaneous statistical equilibrium commonly assumed in numerical modeling. We improve on earlier simulations of the solar atmosphere that only included non-equilibrium hydrogen ionization by performing a 2D radiation-magnetohydrodynamics simulation featuring non-equilibrium ionization of both hydrogen and helium. The simulation includes the effect of hydrogen Lyα and the EUV radiation from the corona on the ionization and heating of the atmosphere. Details on code implementation are given. We obtain helium ion fractions that are far from their equilibrium values. Comparison with models with local thermodynamic equilibrium (LTE) ionization shows that non-equilibrium helium ionization leads to higher temperatures in wavefronts and lower temperatures in the gas between shocks. Assuming LTE ionization results in a thermostat-like behavior with matter accumulating around the temperatures where the LTE ionization fractions change rapidly. Comparison of DEM curves computed from our models shows that non-equilibrium ionization leads to more radiating material in the temperature range 11-18 kK, compared to models with LTE helium ionization. We conclude that non-equilibrium helium ionization is important for the dynamics and thermal structure of the upper chromosphere and transition region. It might also help resolve the problem that intensities of chromospheric lines computed from current models are smaller than those observed.
2. Non-equilibrium STLS approach to transport properties of single impurity Anderson model
2014-04-01
In this work, using the non-equilibrium Keldysh formalism, we study the effects of the electron-electron interaction and the electron-spin correlation on the non-equilibrium Kondo effect and the transport properties of the symmetric single impurity Anderson model (SIAM) at zero temperature by generalizing the self-consistent method of Singwi, Tosi, Land, and Sjolander (STLS) for a single-band tight-binding model with Hubbard type interaction to out of equilibrium steady-states. We at first determine in a self-consistent manner the non-equilibrium spin correlation function, the effective Hubbard interaction, and the double-occupancy at the impurity site. Then, using the non-equilibrium STLS spin polarization function in the non-equilibrium formalism of the iterative perturbation theory (IPT) of Yosida and Yamada, and Horvatic and Zlatic, we compute the spectral density, the current-voltage characteristics and the differential conductance as functions of the applied bias and the strength of on-site Hubbard interaction. We compare our spectral densities at zero bias with the results of numerical renormalization group (NRG) and depict the effects of the electron-electron interaction and electron-spin correlation at the impurity site on the aforementioned properties by comparing our numerical result with the order U2 IPT. Finally, we show that the obtained numerical results on the differential conductance have a quadratic universal scaling behavior and the resulting Kondo temperature shows an exponential behavior.
3. Air Plasma Formation in MHD Slipstream Accelerator for Mercury Lightcraft
SciTech Connect
Myrabo, L.N.; Raizer, Y.P.; Surzhikov, S.
2004-03-30
This paper investigates the physics of air plasma formation at the entrance of the MHD slipstream accelerator for the 'tractor-beam' Mercury Lightcraft. Two scenarios are analyzed. The first addresses the needs of the minimum power airspike assuming that all the power required for air plasma formation must come from the remote laser beam. The second case considers the constant-focus airspike and assumes that the breakdown criteria is satisfied by an on-board auxiliary source (e.g., electric discharge, RF source, microwave source, or E-beam)
4. Air Plasma Formation in MHD Slipstream Accelerator for Mercury Lightcraft
Myrabo, L. N.; Raizer, Y. P.; Surzhikov, S.
2004-03-01
This paper investigates the physics of air plasma formation at the entrance of the MHD slipstream accelerator for the tractor-beam' Mercury Lightcraft. Two scenarios are analyzed. The first addresses the needs of the minimum power airspike assuming that all the power required for air plasma formation must come from the remote laser beam. The second case considers the constant-focus airspike and assumes that the breakdown criteria is satisfied by an on-board auxiliary source (e.g., electric discharge, RF source, microwave source, or E-beam).
5. Colloidal dispersions in external fields: from equilibrium to non-equilibrium
Lowen, Hartmut
2010-03-01
Dispersions of colloidal particles are excellent model systems of classical statistical mechanics in order to understand the principles of self-organization processes. Using an external field (e.g. electric or magnetic field) the effective interaction between the colloidal particles can be tailored and the system can be brought into non-equilibrium in a controlled way. Glass formation after an ultrafast quench in a two-dimensional superparamagnetic binary colloidal mixture [1,2] will be discussed as well as lane [3,4,5,6,7] and band [8] formation in mixtures of charged suspensions and dusty plasmas driven by an electric field. [4pt] References:[0pt] [1] L. Assoud, F. Ebert, P. Keim, R. Messina, G. Maret, H. Lowen, Phys. Rev. Letters 102, 238301 (2009). [0pt] [2] L. Assoud, F. Ebert, P. Keim, R. Messina, G. Maret, H. Lowen, J. Phys.: Condensed Matter 21, 464114 (2009). [0pt] [3] J. Dzubiella, G. P. Hoffmann, H. Lowen, Phys. Rev. E 65, 021402 (1-8) (2002). [0pt] [4] M. E. Leunissen, C. G. Christova, A. P. Hynninen, C. P. Royall, A. I. Campbell, A. Imhof, M. Dijkstra, R. van Roij, A. van Blaaderen, Nature 437, 235 (2005). [0pt] [5] M. Rex, H. Lowen, Phys. Rev. E 75, 051402 (2007). [0pt] [6] M. Rex, C. P. Royall, A. van Blaaderen, H. Lowen, Lane formation in driven colloidal mixtures: is it continuous or discontinuous?, http://arxiv.org/abs/0812.0908 [0pt] [7] K. R. Sutterlin, A. Wysocki, A. V. Ivlev, C. Rath, H. M. Thomas, M. Rubin-Zuzic, W. J. Goedheer, V. E. Fortov, A. M. Lipaev, V. I. Molotkov, O. F. Petrov, G. E. Morfill, H. Lowen, Phys. Rev. Letters 102, 085003 (2009). [0pt] [8] A. Wysocki, H. Lowen, Phys. Rev. E 79, 041408 (2009).
6. Effect of Non-Equilibrium Surface Thermochemistry in Simulation of Carbon Based Ablators
NASA Technical Reports Server (NTRS)
Chen, Yih-Kanq; Gokcen, Tahir
2012-01-01
This study demonstrates that coupling of a material thermal response code and a flow solver using non-equilibrium gas/surface interaction model provides time-accurate solutions for the multidimensional ablation of carbon based charring ablators. The material thermal response code used in this study is the Two-dimensional Implicit Thermal-response and AblatioN Program (TITAN), which predicts charring material thermal response and shape change on hypersonic space vehicles. Its governing equations include total energy balance, pyrolysis gas mass conservation, and a three-component decomposition model. The flow code solves the reacting Navier-Stokes equations using Data Parallel Line Relaxation (DPLR) method. Loose coupling between the material response and flow codes is performed by solving the surface mass balance in DPLR and the surface energy balance in TITAN. Thus, the material surface recession is predicted by finite-rate gas/surface interaction boundary conditions implemented in DPLR, and the surface temperature and pyrolysis gas injection rate are computed in TITAN. Two sets of nonequilibrium gas/surface interaction chemistry between air and the carbon surface developed by Park and Zhluktov, respectively, are studied. Coupled fluid-material response analyses of stagnation tests conducted in NASA Ames Research Center arc-jet facilities are considered. The ablating material used in these arc-jet tests was Phenolic Impregnated Carbon Ablator (PICA). Computational predictions of in-depth material thermal response and surface recession are compared with the experimental measurements for stagnation cold wall heat flux ranging from 107 to 1100 Watts per square centimeter.
7. Non-equilibrium effects upon the non-Markovian Caldeira-Leggett quantum master equation
SciTech Connect
Bolivar, A.O.
2011-05-15
Highlights: > Classical Brownian motion described by a non-Markovian Fokker-Planck equation. > Quantization process. > Quantum Brownian motion described by a non-Markovian Caldeira-Leggett equation. > A non-equilibrium quantum thermal force is predicted. - Abstract: We obtain a non-Markovian quantum master equation directly from the quantization of a non-Markovian Fokker-Planck equation describing the Brownian motion of a particle immersed in a generic environment (e.g. a non-thermal fluid). As far as the especial case of a heat bath comprising of quantum harmonic oscillators is concerned, we derive a non-Markovian Caldeira-Leggett master equation on the basis of which we work out the concept of non-equilibrium quantum thermal force exerted by the harmonic heat bath upon the Brownian motion of a free particle. The classical limit (or dequantization process) of this sort of non-equilibrium quantum effect is scrutinized, as well.
8. The non-equilibrium phase diagrams of flow-induced crystallization and melting of polyethylene.
PubMed
Wang, Zhen; Ju, Jianzhu; Yang, Junsheng; Ma, Zhe; Liu, Dong; Cui, Kunpeng; Yang, Haoran; Chang, Jiarui; Huang, Ningdong; Li, Liangbin
2016-09-09
Combining extensional rheology with in-situ synchrotron ultrafast x-ray scattering, we studied flow-induced phase behaviors of polyethylene (PE) in a wide temperature range up to 240 °C. Non-equilibrium phase diagrams of crystallization and melting under flow conditions are constructed in stress-temperature space, composing of melt, non-crystalline δ, hexagonal and orthorhombic phases. The non-crystalline δ phase is demonstrated to be either a metastable transient pre-order for crystallization or a thermodynamically stable phase. Based on the non-equilibrium phase diagrams, nearly all observations in flow-induced crystallization (FIC) of PE can be well understood. The interplay of thermodynamic stabilities and kinetic competitions of the four phases creates rich kinetic pathways for FIC and diverse final structures. The non-equilibrium flow phase diagrams provide a detailed roadmap for precisely processing of PE with designed structures and properties.
9. The non-equilibrium phase diagrams of flow-induced crystallization and melting of polyethylene
PubMed Central
Wang, Zhen; Ju, Jianzhu; Yang, Junsheng; Ma, Zhe; Liu, Dong; Cui, Kunpeng; Yang, Haoran; Chang, Jiarui; Huang, Ningdong; Li, Liangbin
2016-01-01
Combining extensional rheology with in-situ synchrotron ultrafast x-ray scattering, we studied flow-induced phase behaviors of polyethylene (PE) in a wide temperature range up to 240 °C. Non-equilibrium phase diagrams of crystallization and melting under flow conditions are constructed in stress-temperature space, composing of melt, non-crystalline δ, hexagonal and orthorhombic phases. The non-crystalline δ phase is demonstrated to be either a metastable transient pre-order for crystallization or a thermodynamically stable phase. Based on the non-equilibrium phase diagrams, nearly all observations in flow-induced crystallization (FIC) of PE can be well understood. The interplay of thermodynamic stabilities and kinetic competitions of the four phases creates rich kinetic pathways for FIC and diverse final structures. The non-equilibrium flow phase diagrams provide a detailed roadmap for precisely processing of PE with designed structures and properties. PMID:27609305
10. The non-equilibrium phase diagrams of flow-induced crystallization and melting of polyethylene.
PubMed
Wang, Zhen; Ju, Jianzhu; Yang, Junsheng; Ma, Zhe; Liu, Dong; Cui, Kunpeng; Yang, Haoran; Chang, Jiarui; Huang, Ningdong; Li, Liangbin
2016-01-01
Combining extensional rheology with in-situ synchrotron ultrafast x-ray scattering, we studied flow-induced phase behaviors of polyethylene (PE) in a wide temperature range up to 240 °C. Non-equilibrium phase diagrams of crystallization and melting under flow conditions are constructed in stress-temperature space, composing of melt, non-crystalline δ, hexagonal and orthorhombic phases. The non-crystalline δ phase is demonstrated to be either a metastable transient pre-order for crystallization or a thermodynamically stable phase. Based on the non-equilibrium phase diagrams, nearly all observations in flow-induced crystallization (FIC) of PE can be well understood. The interplay of thermodynamic stabilities and kinetic competitions of the four phases creates rich kinetic pathways for FIC and diverse final structures. The non-equilibrium flow phase diagrams provide a detailed roadmap for precisely processing of PE with designed structures and properties. PMID:27609305
11. The non-equilibrium phase diagrams of flow-induced crystallization and melting of polyethylene
Wang, Zhen; Ju, Jianzhu; Yang, Junsheng; Ma, Zhe; Liu, Dong; Cui, Kunpeng; Yang, Haoran; Chang, Jiarui; Huang, Ningdong; Li, Liangbin
2016-09-01
Combining extensional rheology with in-situ synchrotron ultrafast x-ray scattering, we studied flow-induced phase behaviors of polyethylene (PE) in a wide temperature range up to 240 °C. Non-equilibrium phase diagrams of crystallization and melting under flow conditions are constructed in stress-temperature space, composing of melt, non-crystalline δ, hexagonal and orthorhombic phases. The non-crystalline δ phase is demonstrated to be either a metastable transient pre-order for crystallization or a thermodynamically stable phase. Based on the non-equilibrium phase diagrams, nearly all observations in flow-induced crystallization (FIC) of PE can be well understood. The interplay of thermodynamic stabilities and kinetic competitions of the four phases creates rich kinetic pathways for FIC and diverse final structures. The non-equilibrium flow phase diagrams provide a detailed roadmap for precisely processing of PE with designed structures and properties.
12. Steady-State Density Functional Theory for Non-equilibrium Quantum Systems
Shuanglong, Liu
Recently, electron transport properties of molecular junctions under finite bias voltages have attracted a lot of attention because of the potential application of molecular electronic devices. When a molecular junction is under zero bias voltage at zero temperature, it is in equilibrium ground state and all its properties can be solved by ground-state density functional theory (GS-DFT) where ground-state electron density determines everything. Under finite bias voltage, the molecular junction is in non-equilibrium steady state. According to Hershfield's non-equilibrium statistics, a system in non-equilibrium steady state corresponds to an effective equilibrium system. This correspondence provides the basis for the steady-state density functional theory (SS-DFT) which will be developed in this thesis. (Abstract shortened by UMI.).
13. Air plasma treatment of liquid covered tissue: long timescale chemistry
Lietz, Amanda M.; Kushner, Mark J.
2016-10-01
Atmospheric pressure plasmas have shown great promise for the treatment of wounds and cancerous tumors. In these applications, the sample is usually covered by a thin layer of a biological liquid. The reactive oxygen and nitrogen species (RONS) generated by the plasma activate and are processed by the liquid before the plasma produced activation reaches the tissue. The synergy between the plasma and the liquid, including evaporation and the solvation of ions and neutrals, is critical to understanding the outcome of plasma treatment. The atmospheric pressure plasma sources used in these procedures are typically repetitively pulsed. The processes activated by the plasma sources have multiple timescales—from a few ns during the discharge pulse to many minutes for reactions in the liquid. In this paper we discuss results from a computational investigation of plasma-liquid interactions and liquid phase chemistry using a global model with the goal of addressing this large dynamic range in timescales. In modeling air plasmas produced by a dielectric barrier discharge over liquid covered tissue, 5000 voltage pulses were simulated, followed by 5 min of afterglow. Due to the accumulation of long-lived species such as ozone and N x O y , the gas phase dynamics of the 5000th discharge pulse are different from those of the first pulse, particularly with regards to the negative ions. The consequences of applied voltage, gas flow, pulse repetition frequency, and the presence of organic molecules in the liquid on the gas and liquid reactive species are discussed.
14. Note: Local thermal conductivities from boundary driven non-equilibrium molecular dynamics simulations
SciTech Connect
Bresme, F.; Armstrong, J.
2014-01-07
We report non-equilibrium molecular dynamics simulations of heat transport in models of molecular fluids. We show that the “local” thermal conductivities obtained from non-equilibrium molecular dynamics simulations agree within numerical accuracy with equilibrium Green-Kubo computations. Our results support the local equilibrium hypothesis for transport properties. We show how to use the local dependence of the thermal gradients to quantify the thermal conductivity of molecular fluids for a wide range of thermodynamic states using a single simulation.
15. Non-equilibrium STLS approach to transport properties of single impurity Anderson model
SciTech Connect
2014-04-15
In this work, using the non-equilibrium Keldysh formalism, we study the effects of the electron–electron interaction and the electron-spin correlation on the non-equilibrium Kondo effect and the transport properties of the symmetric single impurity Anderson model (SIAM) at zero temperature by generalizing the self-consistent method of Singwi, Tosi, Land, and Sjolander (STLS) for a single-band tight-binding model with Hubbard type interaction to out of equilibrium steady-states. We at first determine in a self-consistent manner the non-equilibrium spin correlation function, the effective Hubbard interaction, and the double-occupancy at the impurity site. Then, using the non-equilibrium STLS spin polarization function in the non-equilibrium formalism of the iterative perturbation theory (IPT) of Yosida and Yamada, and Horvatic and Zlatic, we compute the spectral density, the current–voltage characteristics and the differential conductance as functions of the applied bias and the strength of on-site Hubbard interaction. We compare our spectral densities at zero bias with the results of numerical renormalization group (NRG) and depict the effects of the electron–electron interaction and electron-spin correlation at the impurity site on the aforementioned properties by comparing our numerical result with the order U{sup 2} IPT. Finally, we show that the obtained numerical results on the differential conductance have a quadratic universal scaling behavior and the resulting Kondo temperature shows an exponential behavior. -- Highlights: •We introduce for the first time the non-equilibrium method of STLS for Hubbard type models. •We determine the transport properties of SIAM using the non-equilibrium STLS method. •We compare our results with order-U2 IPT and NRG. •We show that non-equilibrium STLS, contrary to the GW and self-consistent RPA, produces the two Hubbard peaks in DOS. •We show that the method keeps the universal scaling behavior and correct
16. Studying non-equilibrium many-body dynamics using one-dimensional Bose gases
SciTech Connect
Langen, Tim; Gring, Michael; Kuhnert, Maximilian; Rauer, Bernhard; Geiger, Remi; Mazets, Igor; Smith, David Adu; Schmiedmayer, Jörg; Kitagawa, Takuya; Demler, Eugene
2014-12-04
Non-equilibrium dynamics of isolated quantum many-body systems play an important role in many areas of physics. However, a general answer to the question of how these systems relax is still lacking. We experimentally study the dynamics of ultracold one-dimensional (1D) Bose gases. This reveals the existence of a quasi-steady prethermalized state which differs significantly from the thermal equilibrium of the system. Our results demonstrate that the dynamics of non-equilibrium quantum many-body systems is a far richer process than has been assumed in the past.
17. Non-Equilibrium Thermodynamic Chemistry and the Composition of the Atmosphere of Mars
NASA Technical Reports Server (NTRS)
Levine, J. S.; Summers, M. E.
2003-01-01
A high priority objective of the Mars Exploration Program is to Determine if life exists today (MEPAG Goal I, Objective A). The measurement of gases of biogenic origin may be an approach to detect the presence of microbial life on the surface or subsurface of Mars. Chemical thermodynamic calculations indicate that on both Earth and Mars, certain gases should exist in extremely low concentrations, if at all. Microbial metabolic activity is an important non-equilibrium chemistry process on Earth, and if microbial life exists on Mars, may be an important nonequilibrium chemistry process on Mars. The non-equilibrium chemistry of the atmosphere of Mars is discussed in this paper.
18. The mass and speed dependence of meteor air plasma temperatures.
PubMed
Jenniskens, Peter; Laux, Christophe O; Wilson, Michael A; Schaller, Emily L
2004-01-01
The speed and mass dependence of meteor air plasma temperatures is perhaps the most important data needed to understand how small meteoroids chemically change the ambient atmosphere in their path and enrich the ablated meteoric organic matter with oxygen. Such chemistry can play an important role in creating prebiotic compounds. The excitation conditions in various air plasma emissions were measured from high-resolution optical spectra of Leonid storm meteors during NASA's Leonid Multi-Instrument Aircraft Campaign. This was the first time a sufficient number and range of temperature measurements were obtained to search for meteoroid mass and speed dependencies. We found slight increases in temperature with decreasing altitude, but otherwise nearly constant values for meteoroids with speeds between 35 and 72 km/s and masses between 10(-5) g and 1 g. We conclude that faster and more massive meteoroids produce a larger emission volume, but not a higher air plasma temperature. We speculate that the meteoric plasma may be in multiphase equilibrium with the ambient atmosphere, which could mean lower plasma temperatures in a CO(2)-rich early Earth atmosphere.
19. The mass and speed dependence of meteor air plasma temperatures
NASA Technical Reports Server (NTRS)
Jenniskens, Peter; Laux, Christophe O.; Wilson, Michael A.; Schaller, Emily L.
2004-01-01
The speed and mass dependence of meteor air plasma temperatures is perhaps the most important data needed to understand how small meteoroids chemically change the ambient atmosphere in their path and enrich the ablated meteoric organic matter with oxygen. Such chemistry can play an important role in creating prebiotic compounds. The excitation conditions in various air plasma emissions were measured from high-resolution optical spectra of Leonid storm meteors during NASA's Leonid Multi-Instrument Aircraft Campaign. This was the first time a sufficient number and range of temperature measurements were obtained to search for meteoroid mass and speed dependencies. We found slight increases in temperature with decreasing altitude, but otherwise nearly constant values for meteoroids with speeds between 35 and 72 km/s and masses between 10(-5) g and 1 g. We conclude that faster and more massive meteoroids produce a larger emission volume, but not a higher air plasma temperature. We speculate that the meteoric plasma may be in multiphase equilibrium with the ambient atmosphere, which could mean lower plasma temperatures in a CO(2)-rich early Earth atmosphere.
20. Generation of low-temperature air plasma for food processing
Stepanova, Olga; Demidova, Maria; Astafiev, Alexander; Pinchuk, Mikhail; Balkir, Pinar; Turantas, Fulya
2015-11-01
The project is aimed at developing a physical and technical foundation of generating plasma with low gas temperature at atmospheric pressure for food industry needs. As known, plasma has an antimicrobial effect on the numerous types of microorganisms, including those that cause food spoilage. In this work an original experimental setup has been developed for the treatment of different foods. It is based on initiating corona or dielectric-barrier discharge in a chamber filled with ambient air in combination with a certain helium admixture. The experimental setup provides various conditions of discharge generation (including discharge gap geometry, supply voltage, velocity of gas flow, content of helium admixture in air and working pressure) and allows for the measurement of the electrical discharge parameters. Some recommendations on choosing optimal conditions of discharge generation for experiments on plasma food processing are developed.
1. Comparison of equilibrium and non-equilibrium distribution coefficients for the human drug carbamazepine
Technology Transfer Automated Retrieval System (TEKTRAN)
The distribution coefficient (KD) for the human drug carbamazepine was measured using a non-equilibrium technique. Repacked soil columns were prepared using an Airport silt loam (Typic Natrustalf) with an average organic matter content of 2.45%. Carbamazepine solutions were then leached through th...
2. A non-equilibrium potential function to study competition in neural systems
SciTech Connect
Mejias, Jorge F.
2011-03-24
In this work, I overview some novel results concerning the theoretical calculation of a non-equilibrium potential function for a biologically motivated model of a neural network. Such model displays competition between different populations of excitatory and inhibitory neurons, which is known to originate synchronous dynamics, fast activity oscillations, and other nontrivial behavior in more sophisticated models of neural media.
3. Non-equilibrium condensation process in holographic superconductor with nonlinear electrodynamics
Liu, Yunqi; Gong, Yungui; Wang, Bin
2016-02-01
We study the non-equilibrium condensation process in a holographic superconductor with nonlinear corrections to the U (1) gauge field. We start with an asymptotic Anti-de-Sitter (AdS) black hole against a complex scalar perturbation at the initial time, and solve the dynamics of the gravitational systems in the bulk. When the black hole temperature T is smaller than a critical value T c , the scalar perturbation grows exponentially till saturation, the final state of spacetime approaches to a hairy black hole. In the bulk theory, we find the clue of the influence of nonlinear corrections in the gauge filed on the process of the scalar field condensation. We show that the bulk dynamics in the non-equilibrium process is completely consistent with the observations on the boundary order parameter. Furthermore we examine the time evolution of horizons in the bulk non-equilibrium transformation process from the bald AdS black hole to the AdS hairy hole. Both the evolution of apparent and event horizons show that the original AdS black hole configuration requires more time to finish the transformation to become a hairy black hole if there is nonlinear correction to the electromagnetic field. We generalize our non-equilibrium discussions to the holographic entanglement entropy and find that the holographic entanglement entropy can give us further understanding of the influence of the nonlinearity in the gauge field on the scalar condensation.
4. A time-accurate implicit method for chemical non-equilibrium flows at all speeds
NASA Technical Reports Server (NTRS)
Shuen, Jian-Shun
1992-01-01
A new time accurate coupled solution procedure for solving the chemical non-equilibrium Navier-Stokes equations over a wide range of Mach numbers is described. The scheme is shown to be very efficient and robust for flows with velocities ranging from M less than or equal to 10(exp -10) to supersonic speeds.
5. Rarefied hypersonic flow simulations using the Navier-Stokes equations with non-equilibrium boundary conditions
Greenshields, Christopher J.; Reese, Jason M.
2012-07-01
This paper investigates the use of Navier-Stokes-Fourier equations with non-equilibrium boundary conditions (BCs) for simulation of rarefied hypersonic flows. It revisits a largely forgotten derivation of velocity slip and temperature jump by Patterson, based on Grad's moment method. Mach 10 flow around a cylinder and Mach 12.7 flow over a flat plate are simulated using both computational fluid dynamics using the temperature jump BCs of Patterson and Smoluchowski and the direct simulation Monte-Carlo (DSMC) method. These flows exhibit such strongly non-equilibrium behaviour that, following Patterson's analysis, they are strictly beyond the range of applicability of the BCs. Nevertheless, the results using Patterson's temperature jump BC compare quite well with the DSMC and are consistently better than those using the standard Smoluchowski temperature jump BC. One explanation for this better performance is that an assumption made by Patterson, based on the flow being only slightly non-equilibrium, introduces an additional constraint to the resulting BC model in the case of highly non-equilibrium flows.
6. A non-equilibrium potential function to study competition in neural systems
Mejías, Jorge F.
2011-03-01
In this work, I overview some novel results concerning the theoretical calculation of a non-equilibrium potential function for a biologically motivated model of a neural network. Such model displays competition between different populations of excitatory and inhibitory neurons, which is known to originate synchronous dynamics, fast activity oscillations, and other nontrivial behavior in more sophisticated models of neural media.
7. Rheology modulated non-equilibrium fluctuations in time-dependent diffusion processes
2016-11-01
The effect of non-Newtonian rheology, manifested through a viscoelastic linearized Maxwell model, on the time-dependent non-equilibrium concentration fluctuations due to free diffusion as well as thermal diffusion of a species is analyzed theoretically. Contrary to the belief that non-equilibrium Rayleigh line is not influenced by viscoelastic effects, through rigorous calculations, we put forward the fact that viscoelastic effects do influence the non-equilibrium Rayleigh line, while the effects are absent for the equilibrium scenario. The non-equilibrium process is quantified through the concentration fluctuation auto-correlation function, also known as the structure factor. The analysis reveals that the effect of rheology is prominent for both the cases of free diffusion and thermal diffusion at long times, where the influence of rheology dictates not only the location of the peaks in concentration dynamic structure factors, but also the magnitudes; such peaks in dynamic structure factors are absent in the case of Newtonian fluid. At smaller times, for the case of free diffusion, presence of time-dependent peak(s) are observed, which are weakly dependent on the influence of rheology, a phenomenon which is absent in the case of thermal diffusion. Different regimes of the frequency dependent overall dynamic structure factor, depending on the interplay of the fluid relaxation time and momentum diffusivity, are evaluated. The static structure factor is not affected to a great extent for the case of free-diffusion and is unaffected for the case of thermal diffusion.
8. Inactivation of the biofilm by the air plasma containing water
Suganuma, Ryota; Yasuoka, Koichi; Yasuoka Takeuchi lab Team
2014-10-01
Biofilms are caused by environmental degradation in food factory and medical facilities. Inactivation of biofilm has the method of making it react to chemicals including chlorine, hydrogen peroxide, and ozone. Although inactivation by chemicals has the problem that hazardous property of a residual substance and hydrogen peroxide have slow reaction velocity. We achieved advanced oxidation process (AOP) with air plasma. Hydrogen peroxide and ozone, which were used for the formation of OH radicals in our experiment, were able to be generated selectively by adjusting the amount of water supplied to the plasma. We inactivated Pseudomonas aeruginosa biofilm in five minutes with OH radicals generated by using hydrogen peroxide and ozone.
9. Cold atmospheric pressure air plasma jet for medical applications
SciTech Connect
Kolb, J. F.; Price, R. O.; Bowman, A.; Chiavarini, R. L.; Stacey, M.; Schoenbach, K. H.; Mohamed, A.-A H.; Swanson, R. J.
2008-06-16
By flowing atmospheric pressure air through a direct current powered microhollow cathode discharge, we were able to generate a 2 cm long plasma jet. With increasing flow rate, the flow becomes turbulent and temperatures of the jet are reduced to values close to room temperature. Utilizing the jet, yeast grown on agar can be eradicated with a treatment of only a few seconds. Conversely, animal studies show no skin damage even with exposures ten times longer than needed for pathogen extermination. This cold plasma jet provides an effective mode of treatment for yeast infections of the skin.
10. Cold atmospheric pressure air plasma jet for medical applications
Kolb, J. F.; Mohamed, A.-A. H.; Price, R. O.; Swanson, R. J.; Bowman, A.; Chiavarini, R. L.; Stacey, M.; Schoenbach, K. H.
2008-06-01
By flowing atmospheric pressure air through a direct current powered microhollow cathode discharge, we were able to generate a 2cm long plasma jet. With increasing flow rate, the flow becomes turbulent and temperatures of the jet are reduced to values close to room temperature. Utilizing the jet, yeast grown on agar can be eradicated with a treatment of only a few seconds. Conversely, animal studies show no skin damage even with exposures ten times longer than needed for pathogen extermination. This cold plasma jet provides an effective mode of treatment for yeast infections of the skin.
11. Indoor air cleaning using a pulsed discharge plasma
SciTech Connect
Mizuno, Akira; Kisanuki, Yoshiyuki; Noguchi, Masanobu; Katsura, Shinji; Lee, S.H.; Hong, Y.K.; Shin, S.Y.; Kang, J.H.
1999-12-01
The purpose of this paper is to develop a high-efficiency air-cleaning system for air pollutants such as tobacco smoke found in indoor environments. The authors investigated the basic characteristics of treating particulate matter and acetaldehyde (CH{sub 3}CHO) in a one-pass test using a pulse generator and a plasma-driven catalyst reactor, both of which are attachable to an air conditioner. Using a circulation test, the decrease in acetaldehyde concentration was measured in a closed vessel where the reactor had been placed. The removal efficiencies of particulate matter and acetaldehyde in the one-pass test (residence time of 10 ms) were 70% and 27%, respectively. In the circulation test, 98% of the suspended particles were collected after 2 min of operation and the acetaldehyde concentration decreased by 70% after 50 mins. It is believed that the TiO{sub 2} catalyst is excited by plasma-induced high-energy particles (electrons, photons, and metastable molecules), resulting in an enhanced pollutant removal. These test results indicate that the combination of plasma with TiO{sub 2} is a potential alternative in treating the pollutants in environmental tobacco smoke.
12. Air spark-like plasma source for antimicrobial NOx generation
Pavlovich, M. J.; Ono, T.; Galleher, C.; Curtis, B.; Clark, D. S.; Machala, Z.; Graves, D. B.
2014-12-01
We demonstrate and analyse the generation of nitrogen oxides and their antimicrobial efficacy using atmospheric air spark-like plasmas. Spark-like discharges in air in a 1 L confined volume are shown to generate NOx at an initial rate of about 1.5 × 1016 NOx molecules/J dissipated in the plasma. Such a discharge operating in this confined volume generates on the order of 6000 ppm NOx in 10 min. Around 90% of the NOx is in the form of NO2 after several minutes of operation in the confined volume, suggesting that NO2 is the dominant antimicrobial component. The strong antimicrobial action of the NOx mixture after several minutes of plasma operation is demonstrated by measuring rates of E. coli disinfection on surfaces and in water exposed to the NOx mixture. Some possible applications of plasma generation of NOx (perhaps followed by dissolution in water) include disinfection of surfaces, skin or wound antisepsis, and sterilization of medical instruments at or near room temperature.
13. Infinite-mode squeezed coherent states and non-equilibrium statistical mechanics (phase-space-picture approach)
NASA Technical Reports Server (NTRS)
Yeh, Leehwa
1993-01-01
The phase-space-picture approach to quantum non-equilibrium statistical mechanics via the characteristic function of infinite-mode squeezed coherent states is introduced. We use quantum Brownian motion as an example to show how this approach provides an interesting geometrical interpretation of quantum non-equilibrium phenomena.
14. Cold Micro-Plasma Jets in Atmospheric Pressure Air
Mohamed, A. H.; Suddala, S.; Schoenbach, K. H.
2003-10-01
Direct current microhollow cathode discharges (MHCDs) have been operated in air, nitrogen and oxygen at pressures of one atmosphere. The electrodes are 250 μm thick molybdenum foils, separated by an alumina insulator of the same thickness. A cylindrical hole with a diameter in the 100 μm range is drilled through all layers. By flowing gases at high pressure through this hole, plasma jets with radial dimensions on the same order as the microhole dimensions, and with lengths of up to one centimeter are generated. The gas temperature in these jets was measured by means of a micro-thermocouple. The lowest temperatures of close to room temperature were measured when the flow changed from laminar to turbulent. The results of spectral emission and absorption studies indicate high concentrations of byproducts, such as ozone, when the discharge is operated in air or oxygen. This work is supported by the U.S Air Force Office of Scientific Research (AFOSR).
15. Temperature Anisotropies of Thermal Non-equilibrium Ions by a Nonresonant AlfvÉn Wave
Liu, Hai-Feng; Tang, Chang-Jian; Wang, Xian-Qu; Zhang, Xin; Zhao, Yong
2016-09-01
From a significant view, considering the thermal non-equilibrium factor, we investigate Kappa (κ) ion temperature anisotropies induced by a low-frequency parallel propagating Alfvén wave by combining quasi-linear theory and test particle simulation. Analytic expressions for the ion temperature ratios {T}\\perp i/{T}//i and {T}\\perp i/{T}\\perp j are derived for the solar wind, where {T}\\perp i,{T}//i and {T}\\perp j denote the perpendicular temperature of species i, parallel temperature of species i, and perpendicular temperature of species j, respectively. The results of our model are broadly consistent, compared to observations of solar-wind measurements. Solar wind helium that meets the condition for strong core heating is nearly seven times hotter than hydrogen, on average. Furthermore, we note that we are able to predict the temperature anisotropies of ions based on their thermal non-equilibrium factors.
16. Non-equilibrium behaviour in coacervate-based protocells under electric-field-induced excitation
Yin, Yudan; Niu, Lin; Zhu, Xiaocui; Zhao, Meiping; Zhang, Zexin; Mann, Stephen; Liang, Dehai
2016-02-01
Although numerous strategies are now available to generate rudimentary forms of synthetic cell-like entities, minimal progress has been made in the sustained excitation of artificial protocells under non-equilibrium conditions. Here we demonstrate that the electric field energization of coacervate microdroplets comprising polylysine and short single strands of DNA generates membrane-free protocells with complex, dynamical behaviours. By confining the droplets within a microfluidic channel and applying a range of electric field strengths, we produce protocells that exhibit repetitive cycles of vacuolarization, dynamical fluctuations in size and shape, chaotic growth and fusion, spontaneous ejection and sequestration of matter, directional capture of solute molecules, and pulsed enhancement of enzyme cascade reactions. Our results highlight new opportunities for the study of non-equilibrium phenomena in synthetic protocells, provide a strategy for inducing complex behaviour in electrostatically assembled soft matter microsystems and illustrate how dynamical properties can be activated and sustained in microcompartmentalized media.
17. Non-equilibrium behaviour in coacervate-based protocells under electric-field-induced excitation
PubMed Central
Yin, Yudan; Niu, Lin; Zhu, Xiaocui; Zhao, Meiping; Zhang, Zexin; Mann, Stephen; Liang, Dehai
2016-01-01
Although numerous strategies are now available to generate rudimentary forms of synthetic cell-like entities, minimal progress has been made in the sustained excitation of artificial protocells under non-equilibrium conditions. Here we demonstrate that the electric field energization of coacervate microdroplets comprising polylysine and short single strands of DNA generates membrane-free protocells with complex, dynamical behaviours. By confining the droplets within a microfluidic channel and applying a range of electric field strengths, we produce protocells that exhibit repetitive cycles of vacuolarization, dynamical fluctuations in size and shape, chaotic growth and fusion, spontaneous ejection and sequestration of matter, directional capture of solute molecules, and pulsed enhancement of enzyme cascade reactions. Our results highlight new opportunities for the study of non-equilibrium phenomena in synthetic protocells, provide a strategy for inducing complex behaviour in electrostatically assembled soft matter microsystems and illustrate how dynamical properties can be activated and sustained in microcompartmentalized media. PMID:26876162
18. Non-equilibrium behaviour in coacervate-based protocells under electric-field-induced excitation.
PubMed
Yin, Yudan; Niu, Lin; Zhu, Xiaocui; Zhao, Meiping; Zhang, Zexin; Mann, Stephen; Liang, Dehai
2016-02-15
Although numerous strategies are now available to generate rudimentary forms of synthetic cell-like entities, minimal progress has been made in the sustained excitation of artificial protocells under non-equilibrium conditions. Here we demonstrate that the electric field energization of coacervate microdroplets comprising polylysine and short single strands of DNA generates membrane-free protocells with complex, dynamical behaviours. By confining the droplets within a microfluidic channel and applying a range of electric field strengths, we produce protocells that exhibit repetitive cycles of vacuolarization, dynamical fluctuations in size and shape, chaotic growth and fusion, spontaneous ejection and sequestration of matter, directional capture of solute molecules, and pulsed enhancement of enzyme cascade reactions. Our results highlight new opportunities for the study of non-equilibrium phenomena in synthetic protocells, provide a strategy for inducing complex behaviour in electrostatically assembled soft matter microsystems and illustrate how dynamical properties can be activated and sustained in microcompartmentalized media.
19. Non-equilibrium oxidation states of zirconium during early stages of metal oxidation
SciTech Connect
Ma, Wen; Yildiz, Bilge; Herbert, F. William; Senanayake, Sanjaya D.
2015-03-09
The chemical state of Zr during the initial, self-limiting stage of oxidation on single crystal zirconium (0001), with oxide thickness on the order of 1 nm, was probed by synchrotron x-ray photoelectron spectroscopy. Quantitative analysis of the Zr 3d spectrum by the spectrum reconstruction method demonstrated the formation of Zr{sup 1+}, Zr{sup 2+}, and Zr{sup 3+} as non-equilibrium oxidation states, in addition to Zr{sup 4+} in the stoichiometric ZrO{sub 2}. This finding resolves the long-debated question of whether it is possible to form any valence states between Zr{sup 0} and Zr{sup 4+} at the metal-oxide interface. The presence of local strong electric fields and the minimization of interfacial energy are assessed and demonstrated as mechanisms that can drive the formation of these non-equilibrium valence states of Zr.
20. Non-equilibrium oxidation states of zirconium during early stages of metal oxidation
DOE PAGESBeta
Ma, Wen; Senanayake, Sanjaya D.; Herbert, F. William; Yildiz, Bilge
2015-03-11
The chemical state of Zr during the initial, self-limiting stage of oxidation on single crystal zirconium (0001), with oxide thickness on the order of 1 nm, was probed by synchrotron x-ray photoelectron spectroscopy. Quantitative analysis of the Zr 3d spectrum by the spectrum reconstruction method demonstrated the formation of Zr1+, Zr2+, and Zr3+ as non-equilibrium oxidation states, in addition to Zr4+ in the stoichiometric ZrO2. This finding resolves the long-debated question of whether it is possible to form any valence states between Zr0 and Zr4+ at the metal-oxide interface. As a result, the presence of local strong electric fields andmore » the minimization of interfacial energy are assessed and demonstrated as mechanisms that can drive the formation of these non-equilibrium valence states of Zr.« less
1. A non-equilibrium equation-of-motion approach to quantum transport utilizing projection operators
Ochoa, Maicol A.; Galperin, Michael; Ratner, Mark A.
2014-11-01
We consider a projection operator approach to the non-equilbrium Green function equation-of-motion (PO-NEGF EOM) method. The technique resolves problems of arbitrariness in truncation of an infinite chain of EOMs and prevents violation of symmetry relations resulting from the truncation (equivalence of left- and right-sided EOMs is shown and symmetry with respect to interchange of Fermi or Bose operators before truncation is preserved). The approach, originally developed by Tserkovnikov (1999 Theor. Math. Phys. 118 85) for equilibrium systems, is reformulated to be applicable to time-dependent non-equilibrium situations. We derive a canonical form of EOMs, thus explicitly demonstrating a proper result for the non-equilibrium atomic limit in junction problems. A simple practical scheme applicable to quantum transport simulations is formulated. We perform numerical simulations within simple models and compare results of the approach to other techniques and (where available) also to exact results.
2. Multiple scales approach to the gas-piston non-equilibrium themodynamics
Chiuchiù, D.; Gubbiotti, G.
2016-05-01
The non-equilibrium thermodynamics of a gas inside a piston is a conceptually simple problem where analytic results are rare. For example, it is hard to find in the literature analytic formulas that describe the heat exchanged with the reservoir when the system either relaxes to equilibrium or is compressed over a finite time. In this paper we derive this kind of analytic formula. To achieve this result, we take the equations derived by Cerino et al (2015 Phys. Rev. E 91 032128) describing the dynamic evolution of a gas-piston system, we cast them in a dimensionless form, and we solve the dimensionless equations with the multiple scales expansion method. With the approximated solutions we obtained, we express in a closed form the heat exchanged by the gas-piston system with the reservoir for a large class of relevant non-equilibrium situations.
3. Nanoscale temperature measurements using non-equilibrium Brownian dynamics of a levitated nanosphere
Millen, J.; Deesuwan, T.; Barker, P.; Anders, J.
2014-06-01
Einstein realized that the fluctuations of a Brownian particle can be used to ascertain the properties of its environment. A large number of experiments have since exploited the Brownian motion of colloidal particles for studies of dissipative processes, providing insight into soft matter physics and leading to applications from energy harvesting to medical imaging. Here, we use heated optically levitated nanospheres to investigate the non-equilibrium properties of the gas surrounding them. Analysing the sphere's Brownian motion allows us to determine the temperature of the centre-of-mass motion of the sphere, its surface temperature and the heated gas temperature in two spatial dimensions. We observe asymmetric heating of the sphere and gas, with temperatures reaching the melting point of the material. This method offers opportunities for accurate temperature measurements with spatial resolution on the nanoscale, and provides a means for testing non-equilibrium thermodynamics.
4. A synthetic playground for non-equilibrium error correction and information processing
Murugan, Arvind
2015-03-01
Biological proofreading mechanisms can lower error rates well below Boltzmann statistics by consuming free energy. By abstracting the principles behind these biochemical mechanisms, we discuss the central ingredients needed for any complex reaction network to perform error correction and the inherent energy-error tradeoffs. We propose that such abstract principles can be implemented and tested in synthetic systems using DNA strand displacement reactions. Such DNA circuits can mimic biochemical models of proofreading because of two central features: 1. exquisite control over reaction kinetics, 2. a DNA analog of ATP hydrolysis. Indeed, such DNA circuits may be used to mimic any non-equilibrium information processing scheme seen in biochemistry, such as adaption and ultra-sensitivity in addition to error correction. We discuss the conceptual and practical benefits from having a well-controlled synthetic playground for non-equilibrium ideas.
5. Low temperature superplasticity of AZ91 magnesium alloy with non-equilibrium grain boundaries
SciTech Connect
Mabuchi, M.; Ameyama, K.; Iwasaki, H.; Higashi, K.
1999-05-28
The superplastic behavior of a fine-grained AZ91 alloy, processed by equal channel angular extrusion, has been investigated in a low temperature range of 423--523 K. The experimental results showed a stress exponent of 2 and the activation energy for superplastic flow was in agreement with that for grain boundary diffusion of magnesium. The alloy with non-equilibrium grain boundary structures exhibited lower superplastic elongation than the alloy with equilibrium grain boundaries. Furthermore, the strain rate for superplastic flow of the former was lower than that of the latter. These differences probably arise because the accommodation process for grain boundary sliding is hampered by the long-range stresses associated with the non-equilibrium grain boundaries.
6. Non-equilibrium Dynamics in the Quantum Brownian Oscillator and the Second Law of Thermodynamics
Kim, Ilki
2012-01-01
We initially prepare a quantum linear oscillator weakly coupled to a bath in equilibrium at an arbitrary temperature. We disturb this system by varying a Hamiltonian parameter of the coupled oscillator, namely, either its spring constant or mass according to an arbitrary but pre-determined protocol in order to perform external work on it. We then derive a closed expression for the reduced density operator of the coupled oscillator along this non-equilibrium process as well as the exact expression pertaining to the corresponding quasi-static process. This immediately allows us to analytically discuss the second law of thermodynamics for non-equilibrium processes. Then we derive a Clausius inequality and obtain its validity supporting the second law, as a consistent generalization of the Clausius equality valid for the quasi-static counterpart, introduced in (Kim and Mahler in Phys. Rev. E 81:011101, 2010, [1]).
7. On Non-Equilibrium Thermodynamics of Space-Time and Quantum Gravity
Munkhammar, Joakim
Based on recent results from general relativistic statistical mechanics and black hole information transfer limits, a space-time entropy-action equivalence is proposed as a generalization of the holographic principle. With this conjecture, the action principle can be replaced by the second law of thermodynamics, and for the Einstein-Hilbert action the Einstein field equations are conceptually the result of thermodynamic equilibrium. For non-equilibrium situations, Jaynes' information-theoretic approach to maximum entropy production is adopted instead of the second law of thermodynamics. As it turns out for appropriate choices of constants, quantum gravity is obtained. For the special case of a free particle the Bekenstein-Verlinde entropy-to-displacement relation of holographic gravity and thus the traditional holographic principle emerges. Although Jacobson's original thermodynamic equilibrium approach proposed that gravity might not necessarily be quantized, this particular non-equilibrium treatment might require it.
8. The non-equilibrium allele frequency spectrum in a Poisson random field framework.
PubMed
Kaj, Ingemar; Mugal, Carina F
2016-10-01
In population genetic studies, the allele frequency spectrum (AFS) efficiently summarizes genome-wide polymorphism data and shapes a variety of allele frequency-based summary statistics. While existing theory typically features equilibrium conditions, emerging methodology requires an analytical understanding of the build-up of the allele frequencies over time. In this work, we use the framework of Poisson random fields to derive new representations of the non-equilibrium AFS for the case of a Wright-Fisher population model with selection. In our approach, the AFS is a scaling-limit of the expectation of a Poisson stochastic integral and the representation of the non-equilibrium AFS arises in terms of a fixation time probability distribution. The known duality between the Wright-Fisher diffusion process and a birth and death process generalizing Kingman's coalescent yields an additional representation. The results carry over to the setting of a random sample drawn from the population and provide the non-equilibrium behavior of sample statistics. Our findings are consistent with and extend a previous approach where the non-equilibrium AFS solves a partial differential forward equation with a non-traditional boundary condition. Moreover, we provide a bridge to previous coalescent-based work, and hence tie several frameworks together. Since frequency-based summary statistics are widely used in population genetics, for example, to identify candidate loci of adaptive evolution, to infer the demographic history of a population, or to improve our understanding of the underlying mechanics of speciation events, the presented results are potentially useful for a broad range of topics.
9. Turbulent mixing and beyond: non-equilibrium processes from atomistic to astrophysical scales I
PubMed Central
Abarzhi, S. I.; Gauthier, S.; Sreenivasan, K. R.
2013-01-01
In this Introduction, we summarize and provide a perspective on 11 articles on ‘Turbulent mixing and beyond’. The papers represent the broad variety of themes of the subject, and are concerned with fundamental aspects of turbulence, mixing and non-equilibrium dynamics. While each paper deals with a specific problem, the collection gives a panoramic overview of the subject at its present state of understanding. PMID:23185063
10. A non-equilibrium model for soil heating and evaporation under extreme conditions
Massman, W. J.
2014-12-01
Extreme heating of soils during fires can have long-term and irreversible consequences and given the increasing use of prescribed fire by land managers and the increasing probability of wildfires associated with global warming, one approach to improving understanding of these consequences is to better understand and model the dynamics of the coupled heat, (liquid) moisture, and vapor transport in soils during extreme heating events. The present study describes a model developed to simulate non-equilibrium soil evaporation and the transport of heat, moisture, and water vapor under conditions during fires where the surface heating of the soil often ranges between 10,000 and 100,000 Wm-2 for several minutes to several hours. The Hertz-Knudsen equation is the basis for constructing the model's non-equilibrium evaporative source term. Model performance is tested against laboratory measurements of soil temperature and moisture changes. Testing the present model with different formulations for soil hydraulic conductivity, water retention curve, water activity, and the non-equilibrium evaporative source term, indicates that virtually all the model's successes result from the use of a temperature dependent condensation coefficient in the evaporative source term, a rather surprising and unexpected result. On the other hand, the model solution is not a completely faithful representation of the laboratory data. Nevertheless, this new non-equilibrium model circumvents many of the problems that plagued an equilibrium model developed for the same purpose (Massman 2012: Water Resources Research 48, WR011710) and provides a much more physically realistic simulation than the earlier model. Finally, the present model should provide insight into modeling of heat and mass transport and evaporation, not only during high temperature and low moisture conditions, but for modeling these soil processes under less extreme environmental conditions as well.
11. Direct-Numerical and Large-Eddy Simulations of a Non-Equilibrium Turbulent Kolmogorov Flow
NASA Technical Reports Server (NTRS)
Woodruff, S. L.; Shebalin, J. V.; Hussaini, M. Y.
1999-01-01
A non-equilibrium form of turbulent Kolmogorov flow is set up by making an instantaneous change in the amplitude of the spatially-periodic forcing. It is found that the response of the flow to this instantaneous change becomes more dramatic as the wavenumber of the forcing is increased, and, at the same time, that the faithfulness with which the large-eddy-simulation results agree with the direct-numerical results decreases.
12. The non-equilibrium allele frequency spectrum in a Poisson random field framework.
PubMed
Kaj, Ingemar; Mugal, Carina F
2016-10-01
In population genetic studies, the allele frequency spectrum (AFS) efficiently summarizes genome-wide polymorphism data and shapes a variety of allele frequency-based summary statistics. While existing theory typically features equilibrium conditions, emerging methodology requires an analytical understanding of the build-up of the allele frequencies over time. In this work, we use the framework of Poisson random fields to derive new representations of the non-equilibrium AFS for the case of a Wright-Fisher population model with selection. In our approach, the AFS is a scaling-limit of the expectation of a Poisson stochastic integral and the representation of the non-equilibrium AFS arises in terms of a fixation time probability distribution. The known duality between the Wright-Fisher diffusion process and a birth and death process generalizing Kingman's coalescent yields an additional representation. The results carry over to the setting of a random sample drawn from the population and provide the non-equilibrium behavior of sample statistics. Our findings are consistent with and extend a previous approach where the non-equilibrium AFS solves a partial differential forward equation with a non-traditional boundary condition. Moreover, we provide a bridge to previous coalescent-based work, and hence tie several frameworks together. Since frequency-based summary statistics are widely used in population genetics, for example, to identify candidate loci of adaptive evolution, to infer the demographic history of a population, or to improve our understanding of the underlying mechanics of speciation events, the presented results are potentially useful for a broad range of topics. PMID:27378747
13. Non-equilibrium growth patterns of carbohydrate and saccharin in gel media
Das, Ishwar; Sharma, Archana; Kumar, Anuj; Lall, R. S.
1997-02-01
Non-equilibrium growth patterns of mono-, di-saccharides and a sweetener saccharin have been developed on microslides in the presence of a dense matrix. Scanned pictures were analyzed and fractal dimensions calculated by a box counting method. Morphologies and fractal dimension were found to depend on the compound-dense matrix composition. In case of di-saccharides, the morphology depends on a linkage between the monomer units.
14. A handheld low temperature atmospheric pressure air plasma gun for nanomaterial synthesis in liquid phase
Yu, Shuang; Wang, Kaile; Zuo, Shasha; Liu, Jiahui; Zhang, Jue; Fang, Jing
2015-10-01
A handheld low temperature atmospheric pressure air plasma gun based on a dielectric barrier structure with hollow electrodes was proposed. The portable plasma gun with an embedded mini air pump was driven by a 12 V direct voltage battery. The air plasma jet generated from the gun could be touched without a common shock hazard. Besides working in air, the plasma gun can also work in water. The diagnostic result of optical emission spectroscopy showed the difference in reactive species of air plasma jet between in air and in water. The plasma gun was excited in 20 ml chloroauric acid aqueous solution with a concentration of 1.214 mM. A significant amount of gold nanoparticles were synthesized after 2 min continuous discharge. The plasma gun with these unique features is applicable in plasma medicine, etching, and s-nthesis of nanomaterials.
15. A handheld low temperature atmospheric pressure air plasma gun for nanomaterial synthesis in liquid phase
SciTech Connect
Yu, Shuang; Wang, Kaile; Zuo, Shasha; Liu, Jiahui; Zhang, Jue Fang, Jing
2015-10-15
A handheld low temperature atmospheric pressure air plasma gun based on a dielectric barrier structure with hollow electrodes was proposed. The portable plasma gun with an embedded mini air pump was driven by a 12 V direct voltage battery. The air plasma jet generated from the gun could be touched without a common shock hazard. Besides working in air, the plasma gun can also work in water. The diagnostic result of optical emission spectroscopy showed the difference in reactive species of air plasma jet between in air and in water. The plasma gun was excited in 20 ml chloroauric acid aqueous solution with a concentration of 1.214 mM. A significant amount of gold nanoparticles were synthesized after 2 min continuous discharge. The plasma gun with these unique features is applicable in plasma medicine, etching, and s-nthesis of nanomaterials.
16. An Initial Non-Equilibrium Porous-Media Model for CFD Simulation of Stirling Regenerators
NASA Technical Reports Server (NTRS)
Tew, Roy C.; Simon, Terry; Gedeon, David; Ibrahim, Mounir; Rong, Wei
2006-01-01
The objective of this paper is to define empirical parameters for an initial thermal non-equilibrium porous-media model for use in Computational Fluid Dynamics (CFD) codes for simulation of Stirling regenerators. The two codes currently used at Glenn Research Center for Stirling modeling are Fluent and CFD-ACE. The codes porous-media models are equilibrium models, which assume solid matrix and fluid are in thermal equilibrium. This is believed to be a poor assumption for Stirling regenerators; Stirling 1-D regenerator models, used in Stirling design, use non-equilibrium regenerator models and suggest regenerator matrix and gas average temperatures can differ by several degrees at a given axial location and time during the cycle. Experimentally based information was used to define: hydrodynamic dispersion, permeability, inertial coefficient, fluid effective thermal conductivity, and fluid-solid heat transfer coefficient. Solid effective thermal conductivity was also estimated. Determination of model parameters was based on planned use in a CFD model of Infinia's Stirling Technology Demonstration Converter (TDC), which uses a random-fiber regenerator matrix. Emphasis is on use of available data to define empirical parameters needed in a thermal non-equilibrium porous media model for Stirling regenerator simulation. Such a model has not yet been implemented by the authors or their associates.
17. A study of non-equilibrium phonons in GaAs/AlAs quantum wells
SciTech Connect
Su, Zhenpeng
1996-11-01
In this thesis we have studied the non-equilibrium phonons in GaAs/AlAs quantum wells via Raman scattering. We have demonstrated experimentally that by taking into account the time-reversal symmetry relation between the Stokes and anti-Stokes Raman cross sections, one can successfully measure the non-equilibrium phonon occupancy in quantum wells. Using this technique, we have studied the subject of resonant intersubband scattering of optical phonons. We find that interface roughness plays an important role in resonant Raman scattering in quantum wells. The lateral size of the smooth regions in such interface is estimated to be of the order of 100 {Angstrom}. Through a study of photoluminescence of GaAs/AlAs quantum wells under high intensity laser excitation, we have found that band nonparabolicity has very little effect on the electron subband energies even for subbands as high as a few hundred meV above the lowest one. This finding may require additional theoretical study to understand its origin. We have also studied phonon confinement and propagation in quantum wells. We show that Raman scattering of non-equilibrium phonons in quantum wells can be a sensitive measure of the spatial extent of the longitudinal optical (LO) phonons. We deduce the coherence length of LO phonons in GaAs/Al{sub x}Ga{sub 1-x}As quantum wells as a function of the Al concentration x.
18. Reaction and internal energy relaxation rates in viscous thermochemically non-equilibrium gas flows
SciTech Connect
Kustova, E. V.; Oblapenko, G. P.
2015-01-15
In the present paper, reaction and energy relaxation rates as well as the normal stress are studied for viscous gas flows with vibrational and chemical non-equilibrium. Using the modified Chapman-Enskog method, multi-temperature models based on the Treanor and Boltzmann vibrational distributions are developed for the general case taking into account all kinds of vibrational energy transitions, exchange reactions, dissociation, and recombination. Integral equations specifying the first-order corrections to the normal mean stress and reaction rates are derived, as well as approximate systems of linear equations for their numerical computation. Generalized thermodynamic driving forces associated with all non-equilibrium processes are introduced. It is shown that normal stresses and rates of non-equilibrium processes can be expressed in terms of the same driving forces; the symmetry of kinetic coefficients in these expressions is proven. The developed general model is applied to a particular case of a pure N{sub 2} viscous flow with slow VT relaxation. Normal stress and rates of vibrational relaxation are studied for various ratios of vibrational and translational temperatures. The cross effects between different vibrational transitions in viscous flows are evaluated, along with the influence of anharmonicity and flow compressibility on the first-order corrections to the relaxation rate. Limits of validity for the widely used Landau–Teller model of vibrational relaxation are indicated.
19. The efficiency of driving chemical reactions by a physical non-equilibrium is kinetically controlled.
PubMed
Göppel, Tobias; Palyulin, Vladimir V; Gerland, Ulrich
2016-07-27
An out-of-equilibrium physical environment can drive chemical reactions into thermodynamically unfavorable regimes. Under prebiotic conditions such a coupling between physical and chemical non-equilibria may have enabled the spontaneous emergence of primitive evolutionary processes. Here, we study the coupling efficiency within a theoretical model that is inspired by recent laboratory experiments, but focuses on generic effects arising whenever reactant and product molecules have different transport coefficients in a flow-through system. In our model, the physical non-equilibrium is represented by a drift-diffusion process, which is a valid coarse-grained description for the interplay between thermophoresis and convection, as well as for many other molecular transport processes. As a simple chemical reaction, we consider a reversible dimerization process, which is coupled to the transport process by different drift velocities for monomers and dimers. Within this minimal model, the coupling efficiency between the non-equilibrium transport process and the chemical reaction can be analyzed in all parameter regimes. The analysis shows that the efficiency depends strongly on the Damköhler number, a parameter that measures the relative timescales associated with the transport and reaction kinetics. Our model and results will be useful for a better understanding of the conditions for which non-equilibrium environments can provide a significant driving force for chemical reactions in a prebiotic setting.
20. A simple non-equilibrium theory of non-contact dissipation force microscopy
Kantorovich, L. N.
2001-02-01
The tip-surface interaction in the non-contact atomic force microscopy (NC-AFM) leads to energy dissipation. Recently, this effect has been harnessed to obtain images with atomic resolution. In an important paper Gauthier and Tsukada (GT) (1999 Phys. Rev. B 60 11716) suggested a theory of this, so-called non-contact dissipation force microscopy (NC-DFM) using a stochastic approach within a simple one-atomic representation of the surface. In this paper we elaborate on this model further, stressing the importance of a consistent non-equilibrium consideration. Then, using a more general model, we offer an alternative derivation based on a rather simple approach to non-equilibrium phenomenon used by Kirkwood for the Brownian motion. We show that our method leads to the final result similar to that obtained in the GT paper. We also discuss some other models for the energy dissipation in NC-AFM. In particular, we emphasise that the stick and slip' (or adhesion hysteresis) model of energy dissipation, although containing a specific element which requires additional features to be incorporated in our model, is to be considered using non-equilibrium methods.
1. Rapid non-equilibrium turnover fluidizes entangled F-actin solutions
McCall, Patrick M.; Kovar, David R.; Gardel, Margaret L.
The actin cytoskeleton of living cells is a semiflexible polymer network which regulates cell division, motility, and morphogenesis by controlling cell shape. These complex shape-changing processes require both mechanical deformation and remodeling of the actin cytoskeleton. Molecular motors generate internal forces to drive deformation, while cytoskeletal remodeling is regulated by non-equilibrium polymer turnover. Although the mechanical properties of equilibrium actin filament (F-actin) networks are well-described by theories of semiflexible polymers, these theories do not incorporate the effects of non-equilibrium turnover. To address this experimentally, we developed a model system in which both the turnover rate and the length distribution of purified F-actin can be tuned independently at steady-state through the combined action of actin regulatory proteins. Specifically we tune the concentrations of cofilin, profilin, and formin to regulate F-actin severing, recycling, and nucleation, respectively. We find that the actin turnover rate can be tuned by cofilin up to 25-fold (31 +/- 2 subunits/sec/filament). Surprisingly, changes in turnover rate have no effect on the steady-state F-actin length distribution, which is instead set by formin concentration. Passive microrheology measurements show that increased turnover leads to striking fluidization in both entangled and crosslinked networks. Non-equilibrium turnover thus enables modulation of network mechanics, which impacts force transmission and material deformation.
2. Shock and Laser Induced Non-Equilibrium Chemistry in Molecular Energetics
Wood, Mitchell; Cherukara, Mathew; Kober, Edward; Strachan, Alejandro
2015-06-01
In this study, we have used large scale reactive molecular dynamics (MD) simulations to study how contrasting initiation mechanisms from either shock or electromagnetic insults compare to traditional thermal initiation. We will show how insults of equal strength but different character can yield vastly different reaction profiles and thus the evolution of hot-spots. For shocked RDX (Up = 2km/s), we find that the collapse of a cylindrical 40 nm diameter pore leads to a significant amount of non-equilibrium reactions followed by the formation of a sustained deflagration wave. In contrast, a hot spot that is seeded into a statically compressed crystal with matching size and temperature will quench over the same timescale, highlighting the importance of insult type. Furthermore, MD simulations of electromagnetic insults coupled to intramolecular vibrations have shown, in some cases, mode specific initial chemistry and altered kinetics of the subsequent decomposition. By leveraging spectroscopic and chemical information gathered in our MD simulations, we have been able to identify and track non-equilibrium vibrational states of these materials and correlate them to these observed changes. Implications of insult dependent reactivity and non-equilibrium chemistry will be discussed.
3. Dynamic scaling for the growth of non-equilibrium fluctuations during thermophoretic diffusion in microgravity.
PubMed
Cerbino, Roberto; Sun, Yifei; Donev, Aleksandar; Vailati, Alberto
2015-01-01
Diffusion processes are widespread in biological and chemical systems, where they play a fundamental role in the exchange of substances at the cellular level and in determining the rate of chemical reactions. Recently, the classical picture that portrays diffusion as random uncorrelated motion of molecules has been revised, when it was shown that giant non-equilibrium fluctuations develop during diffusion processes. Under microgravity conditions and at steady-state, non-equilibrium fluctuations exhibit scale invariance and their size is only limited by the boundaries of the system. In this work, we investigate the onset of non-equilibrium concentration fluctuations induced by thermophoretic diffusion in microgravity, a regime not accessible to analytical calculations but of great relevance for the understanding of several natural and technological processes. A combination of state of the art simulations and experiments allows us to attain a fully quantitative description of the development of fluctuations during transient diffusion in microgravity. Both experiments and simulations show that during the onset the fluctuations exhibit scale invariance at large wave vectors. In a broader range of wave vectors simulations predict a spinodal-like growth of fluctuations, where the amplitude and length-scale of the dominant mode are determined by the thickness of the diffuse layer. PMID:26419420
4. Dynamic scaling for the growth of non-equilibrium fluctuations during thermophoretic diffusion in microgravity
Cerbino, Roberto; Sun, Yifei; Donev, Aleksandar; Vailati, Alberto
2015-09-01
Diffusion processes are widespread in biological and chemical systems, where they play a fundamental role in the exchange of substances at the cellular level and in determining the rate of chemical reactions. Recently, the classical picture that portrays diffusion as random uncorrelated motion of molecules has been revised, when it was shown that giant non-equilibrium fluctuations develop during diffusion processes. Under microgravity conditions and at steady-state, non-equilibrium fluctuations exhibit scale invariance and their size is only limited by the boundaries of the system. In this work, we investigate the onset of non-equilibrium concentration fluctuations induced by thermophoretic diffusion in microgravity, a regime not accessible to analytical calculations but of great relevance for the understanding of several natural and technological processes. A combination of state of the art simulations and experiments allows us to attain a fully quantitative description of the development of fluctuations during transient diffusion in microgravity. Both experiments and simulations show that during the onset the fluctuations exhibit scale invariance at large wave vectors. In a broader range of wave vectors simulations predict a spinodal-like growth of fluctuations, where the amplitude and length-scale of the dominant mode are determined by the thickness of the diffuse layer.
5. Second law considerations on the third law: From Boltzmann and Loschmidt paradox to non equilibrium temperature
Lucia, Umberto
2016-02-01
The balance of forces and processes between the system and the environment and the processes inside the system are the result of the flows of the quanta. Moreover, the transition between two thermodynamic states is the consequence of absorption or emission of quanta, but, during the transition, the entropy variation due to the irreversibility occurs and it breaks any symmetry of time. Consequently, the irreversibility is the result of a transition, a process, an interaction between the system and its environment. This interaction results completely time-irreversible for any real process because of irreversibility. As a consequence, a proof of the third law is obtained proving that the zero temperature state can be achieved only for an infinite work lost for dissipation or in an infinite time. The fundamental role of time both in equilibrium and in non equilibrium analysis is pointed out. Moreover, the non equilibrium temperature is related to the entropy generation and its fluctuation rate; indeed, non-stationary temperature means that the system has not yet attained free energy minimum state, i.e., the maximum entropy state; the consequence is that the zero temperature state can be achieved only for an infinite work lost for dissipation or in an infinite time. In engineering thermodynamics the efficiency is always obtained without any consideration on time, while, here, just the time is introduced as a fundamental quantity of the analysis of non equilibrium states.
6. Universality of non-equilibrium fluctuations in strongly correlated quantum liquids
Ferrier, Meydi; Arakawa, Tomonori; Hata, Tokuro; Fujiwara, Ryo; Delagrange, Raphaëlle; Weil, Raphaël; Deblock, Richard; Sakano, Rui; Oguri, Akira; Kobayashi, Kensuke
2016-03-01
Interacting quantum many-body systems constitute a fascinating research field because they form quantum liquids with remarkable properties and universal behaviour. In fermionic systems, such quantum liquids are realized in helium-3 liquid, heavy fermion systems, neutron stars and cold gases. Their properties in the linear-response regime have been successfully described by the theory of Fermi liquids. The idea is that they behave as an ensemble of non-interacting quasi-particles’. However, non-equilibrium properties have still to be established and remain a key issue of many-body physics. Here, we show a precise experimental demonstration of Landau Fermi liquid theory extended to the non-equilibrium regime in a zero-dimensional system. Combining transport and ultra-sensitive current noise measurements, we have unambiguously identified the SU(2) (ref. ) and SU(4) (refs ,,,,) symmetries of a quantum liquid in a carbon nanotube tuned in the universal Kondo regime. Whereas the free quasi-particle picture is found valid around equilibrium, an enhancement of the current fluctuations is detected out of equilibrium and perfectly explained by an effective charge induced by the residual interaction between quasi-particles. Moreover, an as-yet-unknown scaling law for the effective charge is discovered, suggesting a new non-equilibrium universality. Our method paves a new way to explore the exotic nature of quantum liquids out of equilibrium through their fluctuations in a wide variety of physical systems.
7. Space charge corrected electron emission from an aluminum surface under non-equilibrium conditions
SciTech Connect
Wendelen, W.; Bogaerts, A.; Mueller, B. Y.; Rethfeld, B.; Autrique, D.
2012-06-01
A theoretical study has been conducted of ultrashort pulsed laser induced electron emission from an aluminum surface. Electron emission fluxes retrieved from the commonly employed Fowler-DuBridge theory were compared to fluxes based on a laser-induced non-equilibrium electron distribution. As a result, the two- and three-photon photoelectron emission parameters for the Fowler-DuBridge theory have been approximated. We observe that at regimes where photoemission is important, laser-induced electron emission evolves in a more smooth manner than predicted by the Fowler-DuBridge theory. The importance of the actual electron distribution decreases at higher laser fluences, whereas the contribution of thermionic emission increases. Furthermore, the influence of a space charge effect on electron emission was evaluated by a one dimensional particle-in-cell model. Depending on the fluences, the space charge reduces the electron emission by several orders of magnitude. The influence of the electron emission flux profiles on the effective electron emission was found to be negligible. However, a non-equilibrium electron velocity distribution increases the effective electron emission significantly. Our results show that it is essential to consider the non-equilibrium electron distribution as well as the space charge effect for the description of laser-induced photoemission.
8. Non-equilibrium phase transition in mesoscopic biochemical systems: from stochastic to nonlinear dynamics and beyond.
PubMed
Ge, Hao; Qian, Hong
2011-01-01
A theory for an non-equilibrium phase transition in a driven biochemical network is presented. The theory is based on the chemical master equation (CME) formulation of mesoscopic biochemical reactions and the mathematical method of large deviations. The large deviations theory provides an analytical tool connecting the macroscopic multi-stability of an open chemical system with the multi-scale dynamics of its mesoscopic counterpart. It shows a corresponding non-equilibrium phase transition among multiple stochastic attractors. As an example, in the canonical phosphorylation-dephosphorylation system with feedback that exhibits bistability, we show that the non-equilibrium steady-state (NESS) phase transition has all the characteristics of classic equilibrium phase transition: Maxwell construction, a discontinuous first-derivative of the 'free energy function', Lee-Yang's zero for a generating function and a critical point that matches the cusp in nonlinear bifurcation theory. To the biochemical system, the mathematical analysis suggests three distinct timescales and needed levels of description. They are (i) molecular signalling, (ii) biochemical network nonlinear dynamics, and (iii) cellular evolution. For finite mesoscopic systems such as a cell, motions associated with (i) and (iii) are stochastic while that with (ii) is deterministic. Both (ii) and (iii) are emergent properties of a dynamic biochemical network.
9. Non-equilibrium phase transition in mesoscopic biochemical systems: from stochastic to nonlinear dynamics and beyond
PubMed Central
Ge, Hao; Qian, Hong
2011-01-01
A theory for an non-equilibrium phase transition in a driven biochemical network is presented. The theory is based on the chemical master equation (CME) formulation of mesoscopic biochemical reactions and the mathematical method of large deviations. The large deviations theory provides an analytical tool connecting the macroscopic multi-stability of an open chemical system with the multi-scale dynamics of its mesoscopic counterpart. It shows a corresponding non-equilibrium phase transition among multiple stochastic attractors. As an example, in the canonical phosphorylation–dephosphorylation system with feedback that exhibits bistability, we show that the non-equilibrium steady-state (NESS) phase transition has all the characteristics of classic equilibrium phase transition: Maxwell construction, a discontinuous first-derivative of the ‘free energy function’, Lee–Yang's zero for a generating function and a critical point that matches the cusp in nonlinear bifurcation theory. To the biochemical system, the mathematical analysis suggests three distinct timescales and needed levels of description. They are (i) molecular signalling, (ii) biochemical network nonlinear dynamics, and (iii) cellular evolution. For finite mesoscopic systems such as a cell, motions associated with (i) and (iii) are stochastic while that with (ii) is deterministic. Both (ii) and (iii) are emergent properties of a dynamic biochemical network. PMID:20466813
10. Numerical Simulation of Non-Equilibrium Conjugate Heat Transfer in Tubes Partially Filled with Metallic Foams
Qu, Zhiguo; Xu, Huijin; Tao, Wenquan
Numerical simulation with the Forchheimer flow model and local thermal non-equilibrium model for porous region is performed on forced convective heat transfer in a tube partially filled with metallic foams. Flow and heat transfer of fluid in the hollow region and those of fluid in the porous region are conjugated together via the coupling conditions at porous-fluid interface. A heat flow model is proposed with special numerical treatments employed for non-equilibrium conjugated heat transfer in foam-fluid system. Velocity and temperature profiles in the flow direction are obtained and validated with analytical results. Effects of porosity, pore density, dimensionless interfacial radius and fluid-to-solid thermal conductivity ratio on flow characteristics and thermal performance are examined. Accordingly, the entrance effect is analyzed through the numerical simulation in terms of both flow and heat transfer. The present tube exhibits more excellent heat transfer performance at the expense of moderate pressure drop compared with the tube without porous material. The numerical work is not only developed for forced convection in metal-foam partially filled tube, but can also be extended to similar problem with porous-fluid interface for other porous media with significant thermal non-equilibrium effect.
11. Dynamic scaling for the growth of non-equilibrium fluctuations during thermophoretic diffusion in microgravity
PubMed Central
Cerbino, Roberto; Sun, Yifei; Donev, Aleksandar; Vailati, Alberto
2015-01-01
Diffusion processes are widespread in biological and chemical systems, where they play a fundamental role in the exchange of substances at the cellular level and in determining the rate of chemical reactions. Recently, the classical picture that portrays diffusion as random uncorrelated motion of molecules has been revised, when it was shown that giant non-equilibrium fluctuations develop during diffusion processes. Under microgravity conditions and at steady-state, non-equilibrium fluctuations exhibit scale invariance and their size is only limited by the boundaries of the system. In this work, we investigate the onset of non-equilibrium concentration fluctuations induced by thermophoretic diffusion in microgravity, a regime not accessible to analytical calculations but of great relevance for the understanding of several natural and technological processes. A combination of state of the art simulations and experiments allows us to attain a fully quantitative description of the development of fluctuations during transient diffusion in microgravity. Both experiments and simulations show that during the onset the fluctuations exhibit scale invariance at large wave vectors. In a broader range of wave vectors simulations predict a spinodal-like growth of fluctuations, where the amplitude and length-scale of the dominant mode are determined by the thickness of the diffuse layer. PMID:26419420
12. Reaction and internal energy relaxation rates in viscous thermochemically non-equilibrium gas flows
Kustova, E. V.; Oblapenko, G. P.
2015-01-01
In the present paper, reaction and energy relaxation rates as well as the normal stress are studied for viscous gas flows with vibrational and chemical non-equilibrium. Using the modified Chapman-Enskog method, multi-temperature models based on the Treanor and Boltzmann vibrational distributions are developed for the general case taking into account all kinds of vibrational energy transitions, exchange reactions, dissociation, and recombination. Integral equations specifying the first-order corrections to the normal mean stress and reaction rates are derived, as well as approximate systems of linear equations for their numerical computation. Generalized thermodynamic driving forces associated with all non-equilibrium processes are introduced. It is shown that normal stresses and rates of non-equilibrium processes can be expressed in terms of the same driving forces; the symmetry of kinetic coefficients in these expressions is proven. The developed general model is applied to a particular case of a pure N2 viscous flow with slow VT relaxation. Normal stress and rates of vibrational relaxation are studied for various ratios of vibrational and translational temperatures. The cross effects between different vibrational transitions in viscous flows are evaluated, along with the influence of anharmonicity and flow compressibility on the first-order corrections to the relaxation rate. Limits of validity for the widely used Landau-Teller model of vibrational relaxation are indicated.
13. Dynamic scaling for the growth of non-equilibrium fluctuations during thermophoretic diffusion in microgravity.
PubMed
Cerbino, Roberto; Sun, Yifei; Donev, Aleksandar; Vailati, Alberto
2015-09-30
Diffusion processes are widespread in biological and chemical systems, where they play a fundamental role in the exchange of substances at the cellular level and in determining the rate of chemical reactions. Recently, the classical picture that portrays diffusion as random uncorrelated motion of molecules has been revised, when it was shown that giant non-equilibrium fluctuations develop during diffusion processes. Under microgravity conditions and at steady-state, non-equilibrium fluctuations exhibit scale invariance and their size is only limited by the boundaries of the system. In this work, we investigate the onset of non-equilibrium concentration fluctuations induced by thermophoretic diffusion in microgravity, a regime not accessible to analytical calculations but of great relevance for the understanding of several natural and technological processes. A combination of state of the art simulations and experiments allows us to attain a fully quantitative description of the development of fluctuations during transient diffusion in microgravity. Both experiments and simulations show that during the onset the fluctuations exhibit scale invariance at large wave vectors. In a broader range of wave vectors simulations predict a spinodal-like growth of fluctuations, where the amplitude and length-scale of the dominant mode are determined by the thickness of the diffuse layer.
14. Non-equilibrium ionization by a periodic electron beam. I. Synthetic coronal spectra and implications for interpretation of observations
Dzifčáková, E.; Dudík, J.; Mackovjak, Š.
2016-05-01
Context. Coronal heating is currently thought to proceed via the mechanism of nanoflares, small-scale and possibly recurring heating events that release magnetic energy. Aims: We investigate the effects of a periodic high-energy electron beam on the synthetic spectra of coronal Fe ions. Methods: Initially, the coronal plasma is assumed to be Maxwellian with a temperature of 1 MK. The high-energy beam, described by a κ-distribution, is then switched on every period P for the duration of P/ 2. The periods are on the order of several tens of seconds, similar to exposure times or cadences of space-borne spectrometers. Ionization, recombination, and excitation rates for the respective distributions are used to calculate the resulting non-equilibrium ionization state of Fe and the instantaneous and period-averaged synthetic spectra. Results: Under the presence of the periodic electron beam, the plasma is out of ionization equilibrium at all times. The resulting spectra averaged over one period are almost always multithermal if interpreted in terms of ionization equilibrium for either a Maxwellian or a κ-distribution. Exceptions occur, however; the EM-loci curves appear to have a nearly isothermal crossing-point for some values of κs. The instantaneous spectra show fast changes in intensities of some lines, especially those formed outside of the peak of the respective EM(T) distributions if the ionization equilibrium is assumed. Movies 1-5 are available in electronic form at http://www.aanda.org
15. Development of unified Reynolds stress models for non-equilibrium turbulent flows
Xu, Xiang-Hua
Turbulence modeling has played a major role in the calculation of turbulent flows of engineering importance. To solve the flow problems that arise in both nature and engineering, a variety of Reynolds stress models--including simple eddy viscosity models based on the Prandtl mixing length hypothesis, one-equation and two-equation models, nonlinear two-equation and explicit algebraic stress models, as well as full second-order closures--have been proposed during the past few decades. These models, which are typically based on benchmark near-equilibrium turbulence experimental data, perform fairly well in a variety of turbulent flows that are not far from equilibrium. However, it is now well recognized that these models cannot correctly predict turbulent flows that are far from equilibrium. In this dissertation, it is shown that they cannot even properly predict homogeneous turbulent flows that are in strongly strained non-equilibrium states. Two benchmark flows--homogeneous turbulent shear flow and homogeneous plane strain turbulence--are chosen to evaluate the performance of existing turbulence models since these two benchmark flows constitute idealizations of real engineering turbulent flows. It is found that none of the existing Reynolds stress models (including a recent version of a non-equilibrium, near-wall model) can predict results that compare favorably with Rapid Distortion Theory (RDT) in strongly distorted turbulent flows that are far from equilibrium. Moreover, it is demonstrated that the standard linear and nonlinear two-equation models can predict enormous negative values of the normal Reynolds stresses in non-equilibrium homogeneous turbulence that strongly violate basic realizability constraints. In light of the poor performance of existing Reynolds stress models in non-equilibrium homogeneous turbulence, two new Reynolds stress models are developed herein--an explicit algebraic stress model and a full second-order closure--that can correctly
16. Model for describing non-equilibrium helium plasma energy level population
Kavyrshin, D. I.; Chinnov, V. F.; Ageev, A. G.
2015-11-01
A new method for calculating the population of excited levels of helium atoms and ions is suggested. The method is based on direct solution of a system of balance equations for all energy levels for which it was possible to obtain process speed constants. The equations include terms for the processes of particle loss and income by excitation and deexcitation, ionization and recombination as well as losses due to diffusion and radiation. The challenge of solution of such large system is also discussed.
17. Roles of bulk viscosity on Rayleigh-Taylor instability: Non-equilibrium thermodynamics due to spatio-temporal pressure fronts
Sengupta, Tapan K.; Sengupta, Aditi; Sharma, Nidhi; Sengupta, Soumyo; Bhole, Ashish; Shruti, K. S.
2016-09-01
Direct numerical simulations of Rayleigh-Taylor instability (RTI) between two air masses with a temperature difference of 70 K is presented using compressible Navier-Stokes formulation in a non-equilibrium thermodynamic framework. The two-dimensional flow is studied in an isolated box with non-periodic walls in both vertical and horizontal directions. The non-conducting interface separating the two air masses is impulsively removed at t = 0 (depicting a heaviside function). No external perturbation has been used at the interface to instigate the instability at the onset. Computations have been carried out for rectangular and square cross sections. The formulation is free of Boussinesq approximation commonly used in many Navier-Stokes formulations for RTI. Effect of Stokes' hypothesis is quantified, by using models from acoustic attenuation measurement for the second coefficient of viscosity from two experiments. Effects of Stokes' hypothesis on growth of mixing layer and evolution of total entropy for the Rayleigh-Taylor system are reported. The initial rate of growth is observed to be independent of Stokes' hypothesis and the geometry of the box. Following this stage, growth rate is dependent on the geometry of the box and is sensitive to the model used. As a consequence of compressible formulation, we capture pressure wave-packets with associated reflection and rarefaction from the non-periodic walls. The pattern and frequency of reflections of pressure waves noted specifically at the initial stages are reflected in entropy variation of the system.
18. Non-equilibrium thermodynamical description of rhythmic motion patterns of active systems: a canonical-dissipative approach.
PubMed
Dotov, D G; Kim, S; Frank, T D
2015-02-01
We derive explicit expressions for the non-equilibrium thermodynamical variables of a canonical-dissipative limit cycle oscillator describing rhythmic motion patterns of active systems. These variables are statistical entropy, non-equilibrium internal energy, and non-equilibrium free energy. In particular, the expression for the non-equilibrium free energy is derived as a function of a suitable control parameter. The control parameter determines the Hopf bifurcation point of the deterministic active system and describes the effective pumping of the oscillator. In analogy to the equilibrium free energy of the Landau theory, it is shown that the non-equilibrium free energy decays as a function of the control parameter. In doing so, a similarity between certain equilibrium and non-equilibrium phase transitions is pointed out. Data from an experiment on human rhythmic movements is presented. Estimates for pumping intensity as well as the thermodynamical variables are reported. It is shown that in the experiment the non-equilibrium free energy decayed when pumping intensity was increased, which is consistent with the theory. Moreover, pumping intensities close to zero could be observed at relatively slow intended rhythmic movements. In view of the Hopf bifurcation underlying the limit cycle oscillator model, this observation suggests that the intended limit cycle movements were actually more similar to trajectories of a randomly perturbed stable focus.
19. Non-equilibrium thermodynamical description of rhythmic motion patterns of active systems: a canonical-dissipative approach.
PubMed
Dotov, D G; Kim, S; Frank, T D
2015-02-01
We derive explicit expressions for the non-equilibrium thermodynamical variables of a canonical-dissipative limit cycle oscillator describing rhythmic motion patterns of active systems. These variables are statistical entropy, non-equilibrium internal energy, and non-equilibrium free energy. In particular, the expression for the non-equilibrium free energy is derived as a function of a suitable control parameter. The control parameter determines the Hopf bifurcation point of the deterministic active system and describes the effective pumping of the oscillator. In analogy to the equilibrium free energy of the Landau theory, it is shown that the non-equilibrium free energy decays as a function of the control parameter. In doing so, a similarity between certain equilibrium and non-equilibrium phase transitions is pointed out. Data from an experiment on human rhythmic movements is presented. Estimates for pumping intensity as well as the thermodynamical variables are reported. It is shown that in the experiment the non-equilibrium free energy decayed when pumping intensity was increased, which is consistent with the theory. Moreover, pumping intensities close to zero could be observed at relatively slow intended rhythmic movements. In view of the Hopf bifurcation underlying the limit cycle oscillator model, this observation suggests that the intended limit cycle movements were actually more similar to trajectories of a randomly perturbed stable focus. PMID:25619737
20. Calcium influx through TRP channels induced by short-lived reactive species in plasma-irradiated solution
PubMed Central
Sasaki, Shota; Kanzaki, Makoto; Kaneko, Toshiro
2016-01-01
Non-equilibrium helium atmospheric-pressure plasma (He-APP), which allows for a strong non-equilibrium chemical reaction of O2 and N2 in ambient air, uniquely produces multiple extremely reactive products, such as reactive oxygen species (ROS), in plasma-irradiated solution. We herein show that relatively short-lived unclassified reactive species (i.e., deactivated within approximately 10 min) generated by the He-APP irradiation can trigger physiologically relevant Ca2+ influx through ruthenium red- and SKF 96365-sensitive Ca2+-permeable channel(s), possibly transient receptor potential channel family member(s). Our results provide novel insight into understanding of the interactions between cells and plasmas and the mechanism by which cells detect plasma-induced chemically reactive species, in addition to facilitating development of plasma applications in medicine. PMID:27169489
1. An Initial Non-Equilibrium Porous-Media Model for CFD Simulation of Stirling Regenerators
NASA Technical Reports Server (NTRS)
Tew, Roy; Simon, Terry; Gedeon, David; Ibrahim, Mounir; Rong, Wei
2006-01-01
The objective of this paper is to define empirical parameters (or closwre models) for an initial thermai non-equilibrium porous-media model for use in Computational Fluid Dynamics (CFD) codes for simulation of Stirling regenerators. The two CFD codes currently being used at Glenn Research Center (GRC) for Stirling engine modeling are Fluent and CFD-ACE. The porous-media models available in each of these codes are equilibrium models, which assmne that the solid matrix and the fluid are in thermal equilibrium at each spatial location within the porous medium. This is believed to be a poor assumption for the oscillating-flow environment within Stirling regenerators; Stirling 1-D regenerator models, used in Stirling design, we non-equilibrium regenerator models and suggest regenerator matrix and gas average temperatures can differ by several degrees at a given axial location end time during the cycle. A NASA regenerator research grant has been providing experimental and computational results to support definition of various empirical coefficients needed in defining a noa-equilibrium, macroscopic, porous-media model (i.e., to define "closure" relations). The grant effort is being led by Cleveland State University, with subcontractor assistance from the University of Minnesota, Gedeon Associates, and Sunpower, Inc. Friction-factor and heat-transfer correlations based on data taken with the NASAlSunpower oscillating-flow test rig also provide experimentally based correlations that are useful in defining parameters for the porous-media model; these correlations are documented in Gedeon Associates' Sage Stirling-Code Manuals. These sources of experimentally based information were used to define the following terms and parameters needed in the non-equilibrium porous-media model: hydrodynamic dispersion, permeability, inertial coefficient, fluid effective thermal conductivity (including themal dispersion and estimate of tortuosity effects}, and fluid-solid heat transfer
2. Entropy Reduction and Regular Pattern Formation in a Nonlinear Non-equilibrium System: An Energetic Approach
Ozawa, H.; Shimokawa, S.
2005-12-01
Regular pattern formation in a nonlinear non-equilibrium system is investigated from an energetic viewpoint. A nonlinear system is driven by available energy (energy available for conversion to kinetic energy) supplied from its non-equilibrium surroundings, and this energy is dissipated through small-scale dissipation processes in the system (i.e., entropy production). A power balance equation is formulated for the change rate of the total available energy of a system: C = G - D, where G is the generation rate of the available energy and D is the dissipation rate due to thermal and viscous dissipation (entropy production). The change rate C is zero when the concerned system is in a steady state, whereas it is positive (acceleration) or negative (deceleration) in non-steady transitional periods. A fluctuation in a macroscopic physical variable, such as fluid velocity, can change the value G, while it does not change the value D immediately when the scale of the fluctuation is larger than the dissipation scale. The large-scale fluctuation that increases G can therefore grow by the positive gain in the available energy (C > 0) through a nonlinear feedback process. This feedback process can thus drive the system towards a state with the maximum G, which also corresponds to the maximum D in the steady state (C = 0). It follows from mathematical manipulation that the change rate C is proportional to the decrease rate of entropy of a concerned system - the system's entropy must decrease during the acceleration period (C > 0). This result is consistent with our observations that regular patterns or orderly structures emerge spontaneously in the developing stages of the nonlinear non-equilibrium systems. Some examples (e.g., Benard convection, ocean circulation and granular pattern formation) are discussed in this respect.
3. Non-equilibrium thermodynamics, maximum entropy production and Earth-system evolution.
PubMed
Kleidon, Axel
2010-01-13
The present-day atmosphere is in a unique state far from thermodynamic equilibrium. This uniqueness is for instance reflected in the high concentration of molecular oxygen and the low relative humidity in the atmosphere. Given that the concentration of atmospheric oxygen has likely increased throughout Earth-system history, we can ask whether this trend can be generalized to a trend of Earth-system evolution that is directed away from thermodynamic equilibrium, why we would expect such a trend to take place and what it would imply for Earth-system evolution as a whole. The justification for such a trend could be found in the proposed general principle of maximum entropy production (MEP), which states that non-equilibrium thermodynamic systems maintain steady states at which entropy production is maximized. Here, I justify and demonstrate this application of MEP to the Earth at the planetary scale. I first describe the non-equilibrium thermodynamic nature of Earth-system processes and distinguish processes that drive the system's state away from equilibrium from those that are directed towards equilibrium. I formulate the interactions among these processes from a thermodynamic perspective and then connect them to a holistic view of the planetary thermodynamic state of the Earth system. In conclusion, non-equilibrium thermodynamics and MEP have the potential to provide a simple and holistic theory of Earth-system functioning. This theory can be used to derive overall evolutionary trends of the Earth's past, identify the role that life plays in driving thermodynamic states far from equilibrium, identify habitability in other planetary environments and evaluate human impacts on Earth-system functioning.
4. Extremes and Threshold Controls on Rangeland Ecosystems and the Evolution of the Non-Equilibrium Paradigm
Reynolds, J. F.
2001-12-01
The dynamics of rangeland ecosystems involve many factors whose simultaneous action and complex interactions are poorly understood at the relevant temporal and spatial scales. Nonlinear, complex interactions among the drivers of change are some of the main sources of this uncertainty. This includes regime shifts in climate, water movement across landscapes (e.g., key feedbacks between rainfall interception, soil erosion, and nutrient transport), exotic species invasions, and plant physiological responses to episodic rainfall events. In recognition of these nonlinearities, during the past several decades there has been a paradigm switch in ecology, from a balance of nature' to equilibrium/stability to non-equilibrium. Arguably, in no other area of ecology has the equilibrium/non-equilibrium debate been as influential in shaping science discourse, research priorities, and management approaches as in arid and semiarid rangeland grazing systems. For over 50 years, the equilibrium or linear perspective has been the dominant model used for assessment and management in rangeland ecosystems, but it is now recognized that the equilibrium model per se does not, for example, account for the existence of multiple climax' states that may arise out of unique plant-soil-atmosphere interactions, and that removing a disturbance (e.g., grazing) does not automatically result in a resumption of a orderly succession progression. To introduce this session, I will present examples of non-linear extremes and threshold controls on coupled water and nitrogen dynamics in arid/semiarid ecosystems and show how this work has contributed to the evolution of the non-equilibrium paradigm in rangeland ecology.
5. General multi-group macroscopic modeling for thermo-chemical non-equilibrium gas mixtures
SciTech Connect
Liu, Yen Vinokur, Marcel; Panesi, Marco; Sahai, Amal
2015-04-07
This paper opens a new door to macroscopic modeling for thermal and chemical non-equilibrium. In a game-changing approach, we discard conventional theories and practices stemming from the separation of internal energy modes and the Landau-Teller relaxation equation. Instead, we solve the fundamental microscopic equations in their moment forms but seek only optimum representations for the microscopic state distribution function that provides converged and time accurate solutions for certain macroscopic quantities at all times. The modeling makes no ad hoc assumptions or simplifications at the microscopic level and includes all possible collisional and radiative processes; it therefore retains all non-equilibrium fluid physics. We formulate the thermal and chemical non-equilibrium macroscopic equations and rate coefficients in a coupled and unified fashion for gases undergoing completely general transitions. All collisional partners can have internal structures and can change their internal energy states after transitions. The model is based on the reconstruction of the state distribution function. The internal energy space is subdivided into multiple groups in order to better describe non-equilibrium state distributions. The logarithm of the distribution function in each group is expressed as a power series in internal energy based on the maximum entropy principle. The method of weighted residuals is applied to the microscopic equations to obtain macroscopic moment equations and rate coefficients succinctly to any order. The model’s accuracy depends only on the assumed expression of the state distribution function and the number of groups used and can be self-checked for accuracy and convergence. We show that the macroscopic internal energy transfer, similar to mass and momentum transfers, occurs through nonlinear collisional processes and is not a simple relaxation process described by, e.g., the Landau-Teller equation. Unlike the classical vibrational energy
6. General multi-group macroscopic modeling for thermo-chemical non-equilibrium gas mixtures.
PubMed
Liu, Yen; Panesi, Marco; Sahai, Amal; Vinokur, Marcel
2015-04-01
This paper opens a new door to macroscopic modeling for thermal and chemical non-equilibrium. In a game-changing approach, we discard conventional theories and practices stemming from the separation of internal energy modes and the Landau-Teller relaxation equation. Instead, we solve the fundamental microscopic equations in their moment forms but seek only optimum representations for the microscopic state distribution function that provides converged and time accurate solutions for certain macroscopic quantities at all times. The modeling makes no ad hoc assumptions or simplifications at the microscopic level and includes all possible collisional and radiative processes; it therefore retains all non-equilibrium fluid physics. We formulate the thermal and chemical non-equilibrium macroscopic equations and rate coefficients in a coupled and unified fashion for gases undergoing completely general transitions. All collisional partners can have internal structures and can change their internal energy states after transitions. The model is based on the reconstruction of the state distribution function. The internal energy space is subdivided into multiple groups in order to better describe non-equilibrium state distributions. The logarithm of the distribution function in each group is expressed as a power series in internal energy based on the maximum entropy principle. The method of weighted residuals is applied to the microscopic equations to obtain macroscopic moment equations and rate coefficients succinctly to any order. The model's accuracy depends only on the assumed expression of the state distribution function and the number of groups used and can be self-checked for accuracy and convergence. We show that the macroscopic internal energy transfer, similar to mass and momentum transfers, occurs through nonlinear collisional processes and is not a simple relaxation process described by, e.g., the Landau-Teller equation. Unlike the classical vibrational energy
7. Non-equilibrium electron transport in degenerate nitride heterostructures-dynamic screening effects
Anderson, D. R.; Babiker, M.; Bennett, C. R.; Probert, M. I. J.
2003-04-01
We show how dynamic screening effects on non-equilibrium electron transport can be incorporated in the case of electronically dense GaN-based quantum wells. The theory is based on the Boltzmann equation, leading to evaluations of the momentum relaxation time and, hence, the electron mobility in these heterostructures. We find that both screening and anti-screening effects are manifest as the electron density varies. However, anti-screening dominates over a wide range of densities, with screening commencing at densities appropriate for phonon-plasmon coupling.
8. Electron Broadening of Isolated Lines with Stationary Non-Equilibrium Level Populations
SciTech Connect
Iglesias, C A
2005-01-12
It is shown that a quantum kinetic theory approach to line broadening, extended to stationary non-equilibrium states, yields corrections to the standard electron impact widths of isolated lines that depend on the population of the radiator internal levels. A consistent classical limit from a general quantum treatment of the perturbing electrons also introduces corrections to the isolated line widths. Both effects are essential in preserving detailed-balance relations. Preliminary analysis indicates that these corrections may resolve existing discrepancies between theoretical and experimental widths of isolated lines. An experimental test of the results is proposed.
9. Vibrational non-equilibrium in the hydrogen-oxygen reaction. Comparison with experiment
Skrebkov, Oleg V.
2015-03-01
A theoretical model is proposed for the chemical and vibrational kinetics of hydrogen oxidation based on consistent accounting of the vibrational non-equilibrium of the HO2 radical that forms as a result of the bimolecular recombination H+O2 → HO2. In the proposed model, the chain branching H+O2 = O+OH and inhibiting H+O2+M = HO2+M formal reactions are treated (in the terms of elementary processes) as a single multi-channel process of forming, intramolecular energy redistribution between modes, relaxation, and unimolecular decay of the comparatively long-lived vibrationally excited HO2 radical, which is able to react and exchange energy with the other components of the mixture. The model takes into account the vibrational non-equilibrium of the starting (primary) H2 and O2 molecules, as well as the most important molecular intermediates HO2, OH, O2(1Δ), and the main reaction product H2O. It is shown that the hydrogen-oxygen reaction proceeds in the absence of vibrational equilibrium, and the vibrationally excited HO2(v) radical acts as a key intermediate in a fundamentally important chain branching process and in the generation of electronically excited species O2(1Δ), O(1D), and OH(2Σ+). The calculated results are compared with the shock tube experimental data for strongly diluted H2-O2 mixtures at 1000 < T < 2500 K, 0.5 < p < 4 atm. It is demonstrated that this approach is promising from the standpoint of reconciling the predictions of the theoretical model with experimental data obtained by different authors for various compositions and conditions using different methods. For T < 1500 K, the nature of the hydrogen-oxygen reaction is especially non-equilibrium, and the vibrational non-equilibrium of the HO2 radical is the essence of this process. The quantitative estimation of the vibrational relaxation characteristic time of the HO2 radical in its collisions with H2 molecules has been obtained as a result of the comparison of different experimental data on
10. Heat transfer in porous medium embedded with vertical plate: Non-equilibrium approach - Part A
2016-06-01
Heat transfer in a porous medium embedded with vertical flat plate is investigated by using thermal non-equilibrium model. Darcy model is employed to simulate the flow inside porous medium. It is assumed that the heat transfer takes place by natural convection and radiation. The vertical plate is maintained at isothermal temperature. The governing partial differential equations are converted into non-dimensional form and solved numerically using finite element method. Results are presented in terms of isotherms and streamlines for various parameters such as heat transfer coefficient parameter, thermal conductivity ratio, and radiation parameter
11. Evolution of non-equilibrium entanglement networks in spincast thin polymer films
Dalnoki-Veress, Kari; McGraw, Joshua; Fowler, Paul
2012-02-01
Measuring the rheology of non-equilibrium thin polymer films has received significant attention recently. Experiments are typically performed on thin polymer films that inherit their structure from spin coating. While the results of several rheological experiments paint a clear picture, details of molecular configurations in spincast polymer films are still unknown. Here we present the results of crazing measurements which demonstrate that the effective entanglement density of thin polymer films changes as a function of annealing toward a stable equilibrium value. The effective entanglement density plateaus with a time scale on the same order as the bulk reptation time.
12. Equilibrium state and non-equilibrium steady state in an isolated human system
Zheng, Wen-Zhi; Liang, Yuan; Huang, Ji-Ping
2014-02-01
The principle of increasing entropy (PIE) is commonly considered as a universal physical law for natural systems. It also means that a non-equilibrium steady state (NESS) must not appear in any isolated natural systems. Here we experimentally investigate an isolated human social system with a clustering effect. We report that the PIE cannot always hold, and that NESSs can come to appear. Our study highlights the role of human adaptability in the PIE, and makes it possible to study human social systems by using some laws originating from traditional physics.
13. Non-equilibrium Dynamics in Zeeman-Limited Superconducting Al Films
Prestigiacomo, J. C.; Adams, P. W.
2016-05-01
We report non-equilibrium dynamics in the tunneling density of states of ultra-thin Al films in high Zeeman fields. We have measured the transport and tunneling density of states of the films through the first-order Zeeman critical field transition. Films with sheet resistances of a few hundred ohms exhibit slow, non-exponential relaxation in the hysteretic critical field region. The relaxation traces are interspersed with abrupt avalanche-like collapses of the condensate on the superheating branch of the critical field hysteresis loop but not on the supercooling branch. We believe that film dynamics reflects an inhomogeneous order parameter that emerges in the critical field region.
14. Fundamental Properties of Non-equilibrium Laser-Supported Detonation Wave
SciTech Connect
Shiraishi, Hiroyuki
2004-03-30
For developing laser propulsion, it is very important to analyze the mechanism of Laser-Supported Detonation (LSD), because it can generate high pressure and high temperature to be used by laser propulsion can be categorized as one type of hypersonic reacting flows, where exothermicity is supplied not by chemical reaction but by radiation absorption. I have numerically simulated the 1-D and Quasi-1-D LSD waves propagating through an inert gas, which absorbs CO2 gasdynamic laser, using a 2-temperature model. Calculated results show the fundamental properties of the non-equilibrium LSD Waves.
15. Electron-Impact Excitation Cross Sections for Modeling Non-Equilibrium Gas
NASA Technical Reports Server (NTRS)
Huo, Winifred M.; Liu, Yen; Panesi, Marco; Munafo, Alessandro; Wray, Alan; Carbon, Duane F.
2015-01-01
In order to provide a database for modeling hypersonic entry in a partially ionized gas under non-equilibrium, the electron-impact excitation cross sections of atoms have been calculated using perturbation theory. The energy levels covered in the calculation are retrieved from the level list in the HyperRad code. The downstream flow-field is determined by solving a set of continuity equations for each component. The individual structure of each energy level is included. These equations are then complemented by the Euler system of equations. Finally, the radiation field is modeled by solving the radiative transfer equation.
16. Non-equilibrium slave bosons approach to quantum pumping in interacting quantum dots
Citro, Roberta; Romeo, Francesco
2016-03-01
We review a time-dependent slave bosons approach within the non-equilibrium Green's function technique to analyze the charge and spin pumping in a strongly interacting quantum dot. We study the pumped current as a function of the pumping phase and of the dot energy level and show that a parasitic current arises, beyond the pure pumping one, as an effect of the dynamical constraints. We finally illustrate an all-electrical mean for spin-pumping and discuss its relevance for spintronics applications.
17. General multi-group macroscopic modeling for thermo-chemical non-equilibrium gas mixtures.
PubMed
Liu, Yen; Panesi, Marco; Sahai, Amal; Vinokur, Marcel
2015-04-01
This paper opens a new door to macroscopic modeling for thermal and chemical non-equilibrium. In a game-changing approach, we discard conventional theories and practices stemming from the separation of internal energy modes and the Landau-Teller relaxation equation. Instead, we solve the fundamental microscopic equations in their moment forms but seek only optimum representations for the microscopic state distribution function that provides converged and time accurate solutions for certain macroscopic quantities at all times. The modeling makes no ad hoc assumptions or simplifications at the microscopic level and includes all possible collisional and radiative processes; it therefore retains all non-equilibrium fluid physics. We formulate the thermal and chemical non-equilibrium macroscopic equations and rate coefficients in a coupled and unified fashion for gases undergoing completely general transitions. All collisional partners can have internal structures and can change their internal energy states after transitions. The model is based on the reconstruction of the state distribution function. The internal energy space is subdivided into multiple groups in order to better describe non-equilibrium state distributions. The logarithm of the distribution function in each group is expressed as a power series in internal energy based on the maximum entropy principle. The method of weighted residuals is applied to the microscopic equations to obtain macroscopic moment equations and rate coefficients succinctly to any order. The model's accuracy depends only on the assumed expression of the state distribution function and the number of groups used and can be self-checked for accuracy and convergence. We show that the macroscopic internal energy transfer, similar to mass and momentum transfers, occurs through nonlinear collisional processes and is not a simple relaxation process described by, e.g., the Landau-Teller equation. Unlike the classical vibrational energy
18. Cosmological QCD phase transition in steady non-equilibrium dissipative Hořava-Lifshitz early universe
2014-07-01
We study the phase transition from quark-gluon plasma to hadrons in the early universe in the context of non-equilibrium thermodynamics. According to the standard model of cosmology, a phase transition associated with chiral symmetry breaking after the electro-weak transition has occurred when the universe was about 1-10 μs old. We focus attention on such a phase transition in the presence of a viscous relativistic cosmological background fluid in the framework of non-detailed balance Hořava-Lifshitz cosmology within an effective model of QCD. We consider a flat Friedmann-Robertson-Walker universe filled with a non-causal and a causal bulk viscous cosmological fluid respectively and investigate the effects of the running coupling constants of Hořava-Lifshitz gravity, λ, on the evolution of the physical quantities relevant to a description of the early universe, namely, the temperature T, scale factor a, deceleration parameter q and dimensionless ratio of the bulk viscosity coefficient to entropy density ξ/s. We assume that the bulk viscosity cosmological background fluid obeys the evolution equation of the steady truncated (Eckart) and full version of the Israel-Stewart fluid, respectively.
19. Surface modification of PE film by DBD plasma in air
Ren, C.-S.; Wang, K.; Nie, Q.-Y.; Wang, D.-Z.; Guo, S.-H.
2008-12-01
In this paper, surface modification of polyethylene (PE) films is studied by dielectric barrier discharge plasma treatment in air. The treated samples were examined by water contact angle measurement, calculation of surface free energy, Fourier transform infrared attenuated total reflection spectroscopy (FTIR-ATR), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The water contact angle changes from the original value of 93.2° to the minimum value of 53.3° and surface free energy increases from 27.3 to 51.89 J/m 2 after treatment time of 50 s. Both ATR and XPS show some oxidized species are introduced into the sample surface by the plasma treatment and that the change tendencies of the water contact angle and surface free energy with the treatment time are the same as that of the oxygen concentration on the treated sample surface. Cu films were deposited on the treated and untreated PE surfaces. The peel adhesive strength between the Cu film and the treated sample is 1.5 MPa, whereas the value is only 0.8 MPa between the Cu film and the untreated PE. SEM pictures show that the Cu film deposited on the plasma treated PE surface is smooth and the crystal grain is smaller, contrarily the Cu film on the untreated PE surface is rough and the crystal grain is larger.
20. Unusual dileptions at RHIC a field theoretic approach based on a non-equilibrium chiral phase transition
SciTech Connect
Cooper, F.
1997-09-22
This paper contains viewgraphs on unusual dileptons at Brookhaven RHIC. A field theory approach is used based on a non-equilibrium chiral phase transformation utilizing the schroedinger and Heisenberg picture.
1. Potential and flux field landscape theory. I. Global stability and dynamics of spatially dependent non-equilibrium systems.
PubMed
Wu, Wei; Wang, Jin
2013-09-28
We established a potential and flux field landscape theory to quantify the global stability and dynamics of general spatially dependent non-equilibrium deterministic and stochastic systems. We extended our potential and flux landscape theory for spatially independent non-equilibrium stochastic systems described by Fokker-Planck equations to spatially dependent stochastic systems governed by general functional Fokker-Planck equations as well as functional Kramers-Moyal equations derived from master equations. Our general theory is applied to reaction-diffusion systems. For equilibrium spatially dependent systems with detailed balance, the potential field landscape alone, defined in terms of the steady state probability distribution functional, determines the global stability and dynamics of the system. The global stability of the system is closely related to the topography of the potential field landscape in terms of the basins of attraction and barrier heights in the field configuration state space. The effective driving force of the system is generated by the functional gradient of the potential field alone. For non-equilibrium spatially dependent systems, the curl probability flux field is indispensable in breaking detailed balance and creating non-equilibrium condition for the system. A complete characterization of the non-equilibrium dynamics of the spatially dependent system requires both the potential field and the curl probability flux field. While the non-equilibrium potential field landscape attracts the system down along the functional gradient similar to an electron moving in an electric field, the non-equilibrium flux field drives the system in a curly way similar to an electron moving in a magnetic field. In the small fluctuation limit, the intrinsic potential field as the small fluctuation limit of the potential field for spatially dependent non-equilibrium systems, which is closely related to the steady state probability distribution functional, is
2. Experimental observations of non-equilibrium gas-particle partitioning of PAHs in an outdoor smog chamber
SciTech Connect
Coe, D.L.; Kamens, R.M.
1994-12-31
To study non-equilibrium gas-particle partitioning of various PAHs, three specially designed smog chamber experiments were conducted (October 1993, January 1994, and February 1994). Automobile diesel exhaust was injected for five minutes into a 190 m{sup 3} Teflon film chamber and allowed to age during the night at temperatures below 15 C. A large denuder system was utilized during the injection period in order to remove PAH vapors from the injection stream. Thus, PAH-laden particles were observed to off-gas in the near absence of vapor phase PAHs during the initial stages of the 8-hour experiments. The large denuder was designed as a parallel plate system, made of activated charcoal impregnated filters. It was characterized to remove greater than 90% of PAH vapors from the diesel injection system. During the experiments, air samples were collected in the chamber at 20-minute intervals for the first 2 hours, and hourly thereafter. The sampling system consisted of an XAD-4 coated annular denuder, followed by a quartz-fiber filter, which is then followed by a second annular denuder. Sample extracts were analyzed on Hewlett-Packard GC/MS. Results from these experiments are compared to output from a radial diffusion computer model, detailed in another paper (Modeling the Mass Transfer of Semi-Volatile Organics in Combustion Aerosols by Jay R. Odum and Richard M. Kamens).
3. Non-equilibrium dynamics and floral trait interactions shape extant angiosperm diversity
PubMed Central
O'Meara, Brian C.; Smith, Stacey D.; Armbruster, W. Scott; Harder, Lawrence D.; Hardy, Christopher R.; Hileman, Lena C.; Hufford, Larry; Litt, Amy; Magallón, Susana; Smith, Stephen A.; Stevens, Peter F.; Fenster, Charles B.; Diggle, Pamela K.
2016-01-01
Why are some traits and trait combinations exceptionally common across the tree of life, whereas others are vanishingly rare? The distribution of trait diversity across a clade at any time depends on the ancestral state of the clade, the rate at which new phenotypes evolve, the differences in speciation and extinction rates across lineages, and whether an equilibrium has been reached. Here we examine the role of transition rates, differential diversification (speciation minus extinction) and non-equilibrium dynamics on the evolutionary history of angiosperms, a clade well known for the abundance of some trait combinations and the rarity of others. Our analysis reveals that three character states (corolla present, bilateral symmetry, reduced stamen number) act synergistically as a key innovation, doubling diversification rates for lineages in which this combination occurs. However, this combination is currently less common than predicted at equilibrium because the individual characters evolve infrequently. Simulations suggest that angiosperms will remain far from the equilibrium frequencies of character states well into the future. Such non-equilibrium dynamics may be common when major innovations evolve rarely, allowing lineages with ancestral forms to persist, and even outnumber those with diversification-enhancing states, for tens of millions of years. PMID:27147092
4. Non-equilibrium depletion interactions: first things attract, then they repel
Dolata, Benjamin; Zia, Roseanna
2015-11-01
Non-Equilibrium depletion interactions in colloidal dispersions are studied theoretically via a combination of asymptotic and numerical solutions of the Smoluchowski equation. A pair of probes at arbitrary separation is driven by an external force at arbitrary orientation through a suspension, deforming the surrounding microstructure. The degree to which the structure is distorted, and the shape of this deformation, depends on the separation between the probes, on the orientation of the pair to the driving force, and on the strength with which the probes are forced relative to the entropic restoring force of the suspension particles. The resultant non-equilibrium osmotic pressure gradients give rise to both drag and interactive forces between the probes. When the external force is zero, the depletion attraction of Asakura and Oosawa is recovered. When an external force is applied, the interactive force can lead either to attraction or repulsion, as well as deterministic re-orientation of the probes relative to the external force, depending on initial separation, orientation, and strength of forcing. The use of this model for interrogation of non-continuum and elastically networked materials is explored.
5. Generalized Metropolis acceptance criterion for hybrid non-equilibrium molecular dynamics—Monte Carlo simulations
SciTech Connect
Chen, Yunjie; Roux, Benoît
2015-01-14
A family of hybrid simulation methods that combines the advantages of Monte Carlo (MC) with the strengths of classical molecular dynamics (MD) consists in carrying out short non-equilibrium MD (neMD) trajectories to generate new configurations that are subsequently accepted or rejected via an MC process. In the simplest case where a deterministic dynamic propagator is used to generate the neMD trajectories, the familiar Metropolis acceptance criterion based on the change in the total energy ΔE, min[1, exp( − βΔE)], guarantees that the hybrid algorithm will yield the equilibrium Boltzmann distribution. However, the functional form of the acceptance probability is more complex when the non-equilibrium switching process is generated via a non-deterministic stochastic dissipative propagator coupled to a heat bath. Here, we clarify the conditions under which the Metropolis criterion remains valid to rigorously yield a proper equilibrium Boltzmann distribution within hybrid neMD-MC algorithm.
6. Long-lived non-equilibrium states in a quantum-Hall Tomonaga-Luttinger liquid
Fujisawa, Toshimasa; Washio, Kazuhisa; Nakazawa, Ryo; Hashisaka, Masayuki; Muraki, Koji; Tokura, Yasuhiro
The existence of long-lived non-equilibrium states without showing thermalization, which has previously been demonstrated in time evolution of ultracold atoms (quantum quench), suggests the possibility of their spatial analogue in transport behavior of interacting electrons in solid-state systems. Here we report long-lived non-equilibrium states in one-dimensional edge channels in the integer quantum Hall regime. For this purpose, non-trivial binary spectrum composed of hot and cold carriers is prepared by an indirect heating scheme using weakly coupled counterpropagating edge channels in an AlGaAs/GaAs heterostructure. Quantum dot spectroscopy clearly reveals that the carriers with the non-trivial binary spectrum propagate over a long distance (5 - 10 um), much longer than the length required for electronic relaxation (about 0.1 um), without thermalization into a trivial Fermi distribution. This observation is consistent with the integrable model of Tomonaga-Luttinger liquid. The long-lived spectrum implies that the system is well described by non-interacting plasmons, which are attractive for carrying information for a long distance. This work was supported by the JSPS 26247051 and 15H05854, and Nanotechnology Platform Program of MEXT.
7. Non-equilibrium fluid flow around the Yucca Mountain Nuclear Waste Repository
SciTech Connect
Reis, J.C.
1995-08-01
The results of this study are consistent with the G-Tunnel test results, which indicated no water bank forming above the dry zone, and differ from the simulation results based on the equivalent continuum model (ECM), which indicated a water bank may form above the dry zone. The reason that the simulation studies predict the creation of a water bank is that the ECM assumes capillary equilibrium between the fractures and matrix. This study quantified the non-equilibrium fluid flow between the fractures and matrix and has shown that water entering the fractures above the dry zone will drain away from the repository before capillary equilibrium could be created. Thus, the ECM models are inappropriate for many studies of water transport around the proposed Yucca Mountain repository. It is noted that the authors of the ECM studies recognized this limitation and recommended that the more difficult non-equilibrium studies be conducted. It is concluded that a significant water bank above the repository from the redistribution of water from nuclear decay heating is unlikely. Thus, the integrity of the repository is not expected to-be threatened by rewetting of the formation from a water bank.
8. Phase-field investigation on the non-equilibrium interface dynamics of rapid alloy solidification
SciTech Connect
Choi, Jeong
2011-01-01
The research program reported here is focused on critical issues that represent conspicuous gaps in current understanding of rapid solidification, limiting our ability to predict and control microstructural evolution (i.e. morphological dynamics and microsegregation) at high undercooling, where conditions depart significantly from local equilibrium. More specifically, through careful application of phase-field modeling, using appropriate thin-interface and anti-trapping corrections and addressing important details such as transient effects and a velocity-dependent (i.e. adaptive) numerics, the current analysis provides a reasonable simulation-based picture of non-equilibrium solute partitioning and the corresponding oscillatory dynamics associated with single-phase rapid solidification and show that this method is a suitable means for a self-consistent simulation of transient behavior and operating point selection under rapid growth conditions. Moving beyond the limitations of conventional theoretical/analytical treatments of non-equilibrium solute partitioning, these results serve to substantiate recent experimental findings and analytical treatments for single-phase rapid solidification. The departure from the equilibrium solid concentration at the solid-liquid interface was often observed during rapid solidification, and the energetic associated non-equilibrium solute partitioning has been treated in detail, providing possible ranges of interface concentrations for a given growth condition. Use of these treatments for analytical description of specific single-phase dendritic and cellular operating point selection, however, requires a model for solute partitioning under a given set of growth conditions. Therefore, analytical solute trapping models which describe the chemical partitioning as a function of steady state interface velocities have been developed and widely utilized in most of the theoretical investigations of rapid solidification. However, these
9. Giant THz photoconductivity and possible non-equilibrium superconductivity in metallic K3C60
PubMed Central
Mitrano, M.; Cantaluppi, A.; Nicoletti, D.; Kaiser, S.; Perucchi, A.; Lupi, S.; Di Pietro, P.; Pontiroli, D.; Riccò, M.; Clark, S. R.; Jaksch, D.; Cavalleri, A.
2015-01-01
The non-equilibrium control of emergent phenomena in solids is an important research frontier, encompassing effects like the optical enhancement of superconductivity 1 . Recently, nonlinear excitation 2 , 3 of certain phonons in bilayer cuprates was shown to induce superconducting-like optical properties at temperatures far above Tc 4,5,6. This effect was accompanied by the disruption of competing charge-density-wave correlations7,8, which explained some but not all of the experimental results. Here, we report a similar phenomenon in a very different compound. By exciting metallic K3C60 with mid-infrared optical pulses, we induce a large increase in carrier mobility, accompanied by the opening of a gap in the optical conductivity. Strikingly, these same signatures are observed at equilibrium when cooling metallic K3C60 below the superconducting transition temperature (Tc = 20 K). Although optical techniques alone cannot unequivocally identify non-equilibrium high-temperature superconductivity, we propose this scenario as a possible explanation of our results. PMID:26855424
10. Non-equilibrium dynamics and floral trait interactions shape extant angiosperm diversity.
PubMed
O'Meara, Brian C; Smith, Stacey D; Armbruster, W Scott; Harder, Lawrence D; Hardy, Christopher R; Hileman, Lena C; Hufford, Larry; Litt, Amy; Magallón, Susana; Smith, Stephen A; Stevens, Peter F; Fenster, Charles B; Diggle, Pamela K
2016-05-11
Why are some traits and trait combinations exceptionally common across the tree of life, whereas others are vanishingly rare? The distribution of trait diversity across a clade at any time depends on the ancestral state of the clade, the rate at which new phenotypes evolve, the differences in speciation and extinction rates across lineages, and whether an equilibrium has been reached. Here we examine the role of transition rates, differential diversification (speciation minus extinction) and non-equilibrium dynamics on the evolutionary history of angiosperms, a clade well known for the abundance of some trait combinations and the rarity of others. Our analysis reveals that three character states (corolla present, bilateral symmetry, reduced stamen number) act synergistically as a key innovation, doubling diversification rates for lineages in which this combination occurs. However, this combination is currently less common than predicted at equilibrium because the individual characters evolve infrequently. Simulations suggest that angiosperms will remain far from the equilibrium frequencies of character states well into the future. Such non-equilibrium dynamics may be common when major innovations evolve rarely, allowing lineages with ancestral forms to persist, and even outnumber those with diversification-enhancing states, for tens of millions of years.
11. Non-equilibrium entropy and dynamics in a system with long-range interactions
Rocha Filho, T. M.
2016-05-01
We extend the core-halo approach of Levin et al (2014 Phys. Rep. 535, 1) for the violent relaxation of long-range interacting system with a waterbag initial condition, in the case of a widely studied Hamiltonian mean field model. The Gibbs entropy maximization principle is considered with the constraints of energy conservation and of coarse-grained Casimir invariants of the Vlasov equation. The core-halo distribution function depends only on the one-particle mean-field energy, as is expected from the Jeans theorem, and depends on a set of parameters which in our approach is completely determined without having to solve an envelope equation for the contour of the initial state, as required in the original approach. We also show that a different ansatz can be used for the core-halo distribution with similar results. This work also reveals a link between a parametric resonance causing the non-equilibrium phase transition in the model, a dynamical property, and a discontinuity of the (non-equilibrium) entropy of the system.
12. An improved dynamic non-equilibrium wall-model for large eddy simulation
Park, George Ilhwan; Moin, Parviz
2014-01-01
A non-equilibrium wall-model based on unsteady 3D Reynolds-averaged Navier-Stokes (RANS) equations has been implemented in an unstructured mesh environment. The method is similar to that of the wall-model for structured mesh described by Wang and Moin [Phys. Fluids 14, 2043-2051 (2002)], but is supplemented by a new dynamic eddy viscosity/conductivity model that corrects the effect of the resolved Reynolds stress (resolved turbulent heat flux) on the skin friction (wall heat flux). This correction is crucial in predicting the correct level of the skin friction. Unlike earlier models, this eddy viscosity/conductivity model does not have a stress-matching procedure or a tunable free parameter, and it shows consistent performance over a wide range of Reynolds numbers. The wall-model is validated against canonical (attached) transitional and fully turbulent flows at moderate to very high Reynolds numbers: a turbulent channel flow at Reτ = 2000, an H-type transitional boundary layer up to Reθ = 3300, and a high Reynolds number boundary layer at Reθ = 31 000. Application to a separated flow over a NACA4412 airfoil operating close to maximum lift is also considered to test the performance of the wall-model in complex non-equilibrium flows.
13. Molecular dynamics study of CO2 hydrate dissociation: Fluctuation-dissipation and non-equilibrium analysis
English, Niall J.; Clarke, Elaine T.
2013-09-01
Equilibrium and non-equilibrium molecular dynamics (MD) simulations have been performed to investigate thermal-driven break-up of planar CO2 hydrate interfaces in liquid water at 300-320 K. Different guest compositions, at 85%, 95%, and 100% of maximum theoretical occupation, led to statistically-significant differences in the observed initial dissociation rates. The melting temperatures of each interface were estimated, and dissociation rates were observed to be strongly dependent on temperature, with higher dissociation rates at larger over-temperatures vis-à-vis melting. A simple coupled mass and heat transfer model developed previously was applied to fit the observed dissociation profiles, and this helps to identify clearly two distinct régimes of break-up; a second well-defined region is essentially independent of composition and temperature, in which the remaining nanoscale, de facto two-dimensional system's lattice framework is intrinsically unstable. From equilibrium MD of the two-phase systems at their melting point, the relaxation times of the auto-correlation functions of fluctuations in number of enclathrated guest molecules were used as a basis for comparison of the variation in the underlying, non-equilibrium, thermal-driven dissociation rates via Onsager's hypothesis, and statistically significant differences were found, confirming the value of a fluctuation-dissipation approach in this case.
14. New directions in fluid dynamics: non-equilibrium aerodynamic and microsystem flows.
PubMed
Reese, Jason M; Gallis, Michael A; Lockerby, Duncan A
2003-12-15
Fluid flows that do not have local equilibrium are characteristic of some of the new frontiers in engineering and technology, for example, high-speed high-altitude aerodynamics and the development of micrometre-sized fluid pumps, turbines and other devices. However, this area of fluid dynamics is poorly understood from both the experimental and simulation perspectives, which hampers the progress of these technologies. This paper reviews some of the recent developments in experimental techniques and modelling methods for non-equilibrium gas flows, examining their advantages and drawbacks. We also present new results from our computational investigations into both hypersonic and microsystem flows using two distinct numerical methodologies: the direct simulation Monte Carlo method and extended hydrodynamics. While the direct simulation approach produces excellent results and is used widely, extended hydrodynamics is not as well developed but is a promising candidate for future more complex simulations. Finally, we discuss some of the other situations where these simulation methods could be usefully applied, and look to the future of numerical tools for non-equilibrium flows.
15. THERMAL NON-EQUILIBRIUM REVISITED: A HEATING MODEL FOR CORONAL LOOPS
SciTech Connect
Lionello, Roberto; Linker, Jon A.; Mikic, Zoran; Winebarger, Amy R.; Mok, Yung E-mail: linkerj@predsci.com E-mail: amy.r.winebarger@nasa.gov
2013-08-20
The location and frequency of events that heat the million-degree corona are still a matter of debate. One potential heating scenario is that the energy release is effectively steady and highly localized at the footpoints of coronal structures. Such an energy deposition drives thermal non-equilibrium solutions in the hydrodynamic equations in longer loops. This heating scenario was considered and discarded by Klimchuk et al. on the basis of their one-dimensional simulations as incapable of reproducing observational characteristics of loops. In this paper, we use three-dimensional simulations to generate synthetic emission images, from which we select and analyze six loops. The main differences between our model and that of Klimchuk et al. concern (1) dimensionality, (2) resolution, (3) geometrical properties of the loops, (4) heating function, and (5) radiative function. We find evidence, in this small set of simulated loops, that the evolution of the light curves, the variation of temperature along the loops, the density profile, and the absence of small-scale structures are compatible with the characteristics of observed loops. We conclude that quasi-steady footpoint heating that drives thermal non-equilibrium solutions cannot yet be ruled out as a viable heating scenario for EUV loops.
16. Non-equilibrium disordered Bose gases: condensation, superfluidity and dynamical Bose glass
Chen, Lei; Liang, Zhaoxin; Hu, Ying; Zhang, Zhidong
2016-01-01
In an equilibrium three-dimensional (3D) disordered condensate, it is well established that disorder can generate an amount of normal fluid ρ n equaling to 4/3 of ρ ex , where ρ ex is a sum of interaction-induced quantum depletion and disorder-induced condensate deformation. The concept that the superfluid is more volatile to the existence of disorder than the condensate is crucial to the understanding of the Bose glass phase. In this work, we show that, by bringing a weakly disordered 3D condensate to non-equilibrium regime via a quantum quench in the interaction, disorder can destroy superfluid significantly more, leading to a steady state of Hamiltonian H f in which the ρ n far exceeds 4/3 of the ρ ex . This suggests the possibility of engineering Bose glass in the dynamic regime. Here, we refer to the dynamical Bose glass as the case where in the steady state of quenched condensate, the superfluid density goes to zero while the condensate density remains finite. As both the ρ n and ρ ex are measurable quantities, our results allow an experimental demonstration of the dramatized interplay between the disorder and interaction in the non-equilibrium scenario.
17. Path-space variational inference for non-equilibrium coarse-grained systems
Harmandaris, Vagelis; Kalligiannaki, Evangelia; Katsoulakis, Markos; Plecháč, Petr
2016-06-01
In this paper we discuss information-theoretic tools for obtaining optimized coarse-grained molecular models for both equilibrium and non-equilibrium molecular simulations. The latter are ubiquitous in physicochemical and biological applications, where they are typically associated with coupling mechanisms, multi-physics and/or boundary conditions. In general the non-equilibrium steady states are not known explicitly as they do not necessarily have a Gibbs structure. The presented approach can compare microscopic behavior of molecular systems to parametric and non-parametric coarse-grained models using the relative entropy between distributions on the path space and setting up a corresponding path-space variational inference problem. The methods can become entirely data-driven when the microscopic dynamics are replaced with corresponding correlated data in the form of time series. Furthermore, we present connections and generalizations of force matching methods in coarse-graining with path-space information methods. We demonstrate the enhanced transferability of information-based parameterizations to different observables, at a specific thermodynamic point, due to information inequalities. We discuss methodological connections between information-based coarse-graining of molecular systems and variational inference methods primarily developed in the machine learning community. However, we note that the work presented here addresses variational inference for correlated time series due to the focus on dynamics. The applicability of the proposed methods is demonstrated on high-dimensional stochastic processes given by overdamped and driven Langevin dynamics of interacting particles.
18. Single-molecule measurement of the effective temperature in non-equilibrium steady states
Dieterich, E.; Camunas-Soler, J.; Ribezzi-Crivellari, M.; Seifert, U.; Ritort, F.
2015-11-01
Temperature is a well-defined quantity for systems in equilibrium. For glassy systems, it has been extended to the non-equilibrium regime, showing up as an effective quantity in a modified version of the fluctuation-dissipation theorem. However, experimental evidence supporting this definition remains scarce. Here, we present the first direct experimental demonstration of the effective temperature by measuring correlations and responses in single molecules in non-equilibrium steady states generated under external random forces. We combine experiment, analytical theory and simulations for systems with different levels of complexity, ranging from a single bead in an optical trap to two-state and multiple-state DNA hairpins. From these data, we extract a unifying picture for the existence of an effective temperature based on the relative order of various timescales characterizing intrinsic relaxation and external driving. Our study thus introduces driven small systems as a fertile ground to address fundamental concepts in statistical physics, condensed-matter physics and biophysics.
19. Graphical representation for isothermal kinetics of non-equilibrium grain-boundary segregation
SciTech Connect
Wang Kai; Xu Tingdong; Song Shenhua; Shao Chong
2011-06-15
A model of non-equilibrium grain-boundary segregation of solute is expressed with graphs for the isothermal aging at various temperatures after quenching from a solution temperature. It is found from the graphical representations that when the samples are aged for a certain time at various temperatures there is a maximum value in the segregation concentration at a certain temperature. The aging time is equal or close to the critical time of non-equilibrium segregation corresponding to this temperature. This finding is experimentally confirmed with sulfur in an Ni-base superalloy with the aid of Auger electron spectroscopy. As an application of the new finding, a mechanism for intermediate temperature embrittlement of alloys is suggested and identified experimentally with tension tests of the superalloy. - Research Highlights: {yields} A peak of solute segregation emerges at a temperature when aging for a certain time at various temperatures after quenching. {yields} The aging time is equal or close to the critical time of segregation at this temperature. {yields} This finding is experimentally confirmed in an Ni-Cr-Fe superalloy. {yields} A mechanism for intermediate temperature embrittlement of alloys is proposed.
20. A non-equilibrium state diagram for liquid/fluid/particle mixtures.
PubMed
Velankar, Sachin S
2015-11-21
The equilibrium structures of ternary oil/water/surfactant systems are often represented within a triangular composition diagram with various regions of the triangle corresponding to different equilibrium states. We transplant this idea to ternary liquid/fluid/particle systems that are far from equilibrium. Liquid/liquid/particle mixtures or liquid/gas/particle mixtures yield a wide diversity of morphologies including Pickering emulsions, bijels, pendular aggregates, spherical agglomerates, capillary suspensions, liquid marbles, powdered liquids, and particle-stabilized foams. This paper argues that such ternary liquid/fluid/particle mixtures can be unified into a non-equilibrium state diagram. What is common among all these systems is that the morphology results from an interplay between the preferential wettability of the particles, capillarity, and viscous forces encountered during mixing. Therefore all such systems share certain universal features, regardless of the details of the particles or fluids used. These features guide the construction of a non-equilibrium state diagram which takes the form of a triangular prism, where each triangular cross-section of the prism corresponds to a different relative affinity of the particles towards the two fluids. We classify the prism into regions in which the various morphologies appear and also emphasize the major difference between systems in which the particles are fully-wetted by one of the fluids vs. partially-wetted by both fluids. We also discuss how the state diagram may change with mixing intensity or with interparticle attractions.
1. Non-equilibrium dynamics and floral trait interactions shape extant angiosperm diversity.
PubMed
O'Meara, Brian C; Smith, Stacey D; Armbruster, W Scott; Harder, Lawrence D; Hardy, Christopher R; Hileman, Lena C; Hufford, Larry; Litt, Amy; Magallón, Susana; Smith, Stephen A; Stevens, Peter F; Fenster, Charles B; Diggle, Pamela K
2016-05-11
Why are some traits and trait combinations exceptionally common across the tree of life, whereas others are vanishingly rare? The distribution of trait diversity across a clade at any time depends on the ancestral state of the clade, the rate at which new phenotypes evolve, the differences in speciation and extinction rates across lineages, and whether an equilibrium has been reached. Here we examine the role of transition rates, differential diversification (speciation minus extinction) and non-equilibrium dynamics on the evolutionary history of angiosperms, a clade well known for the abundance of some trait combinations and the rarity of others. Our analysis reveals that three character states (corolla present, bilateral symmetry, reduced stamen number) act synergistically as a key innovation, doubling diversification rates for lineages in which this combination occurs. However, this combination is currently less common than predicted at equilibrium because the individual characters evolve infrequently. Simulations suggest that angiosperms will remain far from the equilibrium frequencies of character states well into the future. Such non-equilibrium dynamics may be common when major innovations evolve rarely, allowing lineages with ancestral forms to persist, and even outnumber those with diversification-enhancing states, for tens of millions of years. PMID:27147092
2. Stability of high-speed boundary layers in oxygen including chemical non-equilibrium effects
Klentzman, Jill; Tumin, Anatoli
2013-11-01
The stability of high-speed boundary layers in chemical non-equilibrium is examined. A parametric study varying the edge temperature and the wall conditions is conducted for boundary layers in oxygen. The edge Mach number and enthalpy ranges considered are relevant to the flight conditions of reusable hypersonic cruise vehicles. Both viscous and inviscid stability formulations are used and the results compared to gain insight into the effects of viscosity and thermal conductivity on the stability. It is found that viscous effects have a strong impact on the temperature and mass fraction perturbations in the critical layer and in the viscous sublayer near the wall. Outside of these areas, the perturbations closely match in the viscous and inviscid models. The impact of chemical non-equilibrium on the stability is investigated by analyzing the effects of the chemical source term in the stability equations. The chemical source term is found to influence the growth rate of the second Mack mode instability but not have much of an effect on the mass fraction eigenfunction for the flow parameters considered. This work was supported by the AFOSR/NASA/National Center for Hypersonic Laminar-Turbulent Transition Research.
3. Non-Equilibrium Dynamics of C-QED Arrays in Strong Correlation Regime
Zhang, Xin-Ding; Li, Zhi-Hang; Zhang, Xiao-Ming
2016-07-01
Recently increasing interests are attracted in the physics of controlled arrays of nonlinear cavity resonators because of the rapid experimental progress achieved in cavity and circuit quantum electrodynamics (QED). For a driven-dissipative two-dimentional planar C-QED array, standard Markov master equation is generally used to study the dynamics of this system. However, when in the case that the on-site photon-photon interaction enters strong correlation regime, standard Markov master equation may lead to incorrect results. In this paper we study the non-equilibrium dynamics of a two-dimentional C-QED array, which is homogeneously pumped by an external pulse, at the same time dissipation exits. We study the evolution of the average photon number of a single cavity by deriving a modified master equation to. In comparison with the standard master equation, the numerical result obtained by our newly derived master equation shows significant difference for the non-equilibrium dynamics of the system.
4. Fiber Bragg grating dynamic demodulation based on non-equilibrium interferometry
Yu, Qi; Jing, Zhenguo; Peng, Wei; Zhang, Xinpu; Liu, Yun; Xing, Chuanqi; Li, Hong; Yao, Wenjuan
2011-12-01
Non-equilibrium interferometric Fiber Bragg Grating (FBG) sensor is suitable for the accurate measurements of high-frequency dynamic stress, vibration, etc because of its high sensitivity and high frequency response compared to other types of FBG sensors. In this paper, a Phase Generation Carrier (PGC) demodulation technique of non-equilibrium interferometric FBG sensor that based on ARCTAN algorithm by using an arctangent algorithm with a simple method, has been investigated ,which can avoid the high-frequency noise increases, the error accumulation, the integrator signal jump of the integrator and other inherent weaknesses in the system. ARCTAN has a better response characteristic of the mutant signals, especially for low-frequency large-signal that can be demodulated with a greater range. The experimental result demonstrate that implementing measured resolution can up to 10nɛ/√Hz@500Hz in vibration strain, a signal sampling rate to 100 KHz and a frequency response range up to 1 KHz. This method can improve the performance of the system greatly which has potential significance for practical sensor application.
5. Asymptotic analysis of discrete schemes for non-equilibrium radiation diffusion
Cui, Xia; Yuan, Guang-wei; Shen, Zhi-jun
2016-05-01
Motivated by providing well-behaved fully discrete schemes in practice, this paper extends the asymptotic analysis on time integration methods for non-equilibrium radiation diffusion in [2] to space discretizations. Therein studies were carried out on a two-temperature model with Larsen's flux-limited diffusion operator, both the implicitly balanced (IB) and linearly implicit (LI) methods were shown asymptotic-preserving. In this paper, we focus on asymptotic analysis for space discrete schemes in dimensions one and two. First, in construction of the schemes, in contrast to traditional first-order approximations, asymmetric second-order accurate spatial approximations are devised for flux-limiters on boundary, and discrete schemes with second-order accuracy on global spatial domain are acquired consequently. Then by employing formal asymptotic analysis, the first-order asymptotic-preserving property for these schemes and furthermore for the fully discrete schemes is shown. Finally, with the help of manufactured solutions, numerical tests are performed, which demonstrate quantitatively the fully discrete schemes with IB time evolution indeed have the accuracy and asymptotic convergence as theory predicts, hence are well qualified for both non-equilibrium and equilibrium radiation diffusion.
6. Cooling and Non-equilibrium Motion of an Ultracold Atomic Gas using Synthetic Thermal Bodies
Price, Craig; Liu, Qi; Zhao, Jianshi; Gemelke, Nathan
2016-05-01
We describe the non-equilibrium behavior of atomic gases immersed in synthetic thermal environments created by engineered statistical reservoirs of spatio-temporally disordered light. By dynamically modulating the modal distribution of an optical fiber carrying far off-resonant light, optical dipole potentials are created for 87 Rb atoms with specified spatial and temporal spectra. Additional coupling to thermal reserviors defined by time-dependent radio-frequency-induced hyperfine spin-couplings offers a wide range of control over thermal excitations. By controlling the statistical properties of the baths, diffusive motion can be tailored in real-time, and transport can be controlled even at ultra-cold temperatures below the photon recoil. The use of an effectively statistical classical body opens new avenues for quantum simulation, and offers opportunities for study of systems governed by effective hamiltonians which are themselves poised near critical points, and the simulation of effectively many-body systems through the non-equilibrium motion of single atoms.
7. Static versus dynamic analysis of the influence of gravity on concentration non-equilibrium fluctuations.
PubMed
Croccolo, Fabrizio; Bataller, Henri; Scheffold, Frank
2014-11-01
In a binary fluid mixture subject to gravity and a stabilizing concentration gradient, concentration non-equilibrium fluctuations are long-ranged. While the gradient leads to an enhancement of the respective equilibrium fluctuations, the effect of gravity is a damping of fluctuations larger than a "characteristic" size. This damping is visible both in the fluctuation power spectrum probed by static and the temporal correlation function probed by dynamic light scattering. One aspect of the "characteristic" size can be appreciated by the dynamic analysis; in fact at the corresponding "characteristic" wave vector q* one can observe a maximum of the fluctuation time constant indicating the more persistent fluctuation of the system. Also in the static analysis a "characteristic" size can be extracted from the crossover wave vector. According to common theoretical concepts, the result should be the same in both cases. In the present work we provide evidence for a systematic difference in the experimentally observed "characteristic" size as obtained by static and dynamic measurements. Our observation thus points out the need for a more refined theory of non-equilibrium concentration fluctuations.
8. Time-dependent non-equilibrium dielectric response in QM/continuum approaches.
PubMed
Ding, Feizhi; Lingerfelt, David B; Mennucci, Benedetta; Li, Xiaosong
2015-01-21
The Polarizable Continuum Models (PCMs) are some of the most inexpensive yet successful methods for including the effects of solvation in quantum-mechanical calculations of molecular systems. However, when applied to the electronic excitation process, these methods are restricted to dichotomously assuming either that the solvent has completely equilibrated with the excited solute charge density (infinite-time limit), or that it retains the configuration that was in equilibrium with the solute prior to excitation (zero-time limit). This renders the traditional PCMs inappropriate for resolving time-dependent solvent effects on non-equilibrium solute electron dynamics like those implicated in the instants following photoexcitation of a solvated molecular species. To extend the existing methods to this non-equilibrium regime, we herein derive and apply a new formalism for a general time-dependent continuum embedding method designed to be propagated alongside the solute's electronic degrees of freedom in the time domain. Given the frequency-dependent dielectric constant of the solvent, an equation of motion for the dielectric polarization is derived within the PCM framework and numerically integrated simultaneously with the time-dependent Hartree fock/density functional theory equations. Results for small molecular systems show the anticipated dipole quenching and electronic state dephasing/relaxation resulting from out-of-phase charge fluctuations in the dielectric and embedded quantum system.
9. Time-dependent non-equilibrium dielectric response in QM/continuum approaches
SciTech Connect
Ding, Feizhi; Lingerfelt, David B.; Li, Xiaosong E-mail: li@chem.washington.edu; Mennucci, Benedetta E-mail: li@chem.washington.edu
2015-01-21
The Polarizable Continuum Models (PCMs) are some of the most inexpensive yet successful methods for including the effects of solvation in quantum-mechanical calculations of molecular systems. However, when applied to the electronic excitation process, these methods are restricted to dichotomously assuming either that the solvent has completely equilibrated with the excited solute charge density (infinite-time limit), or that it retains the configuration that was in equilibrium with the solute prior to excitation (zero-time limit). This renders the traditional PCMs inappropriate for resolving time-dependent solvent effects on non-equilibrium solute electron dynamics like those implicated in the instants following photoexcitation of a solvated molecular species. To extend the existing methods to this non-equilibrium regime, we herein derive and apply a new formalism for a general time-dependent continuum embedding method designed to be propagated alongside the solute’s electronic degrees of freedom in the time domain. Given the frequency-dependent dielectric constant of the solvent, an equation of motion for the dielectric polarization is derived within the PCM framework and numerically integrated simultaneously with the time-dependent Hartree fock/density functional theory equations. Results for small molecular systems show the anticipated dipole quenching and electronic state dephasing/relaxation resulting from out-of-phase charge fluctuations in the dielectric and embedded quantum system.
10. Non-equilibrium oxidation states of zirconium during early stages of metal oxidation
SciTech Connect
Ma, Wen; Senanayake, Sanjaya D.; Herbert, F. William; Yildiz, Bilge
2015-03-11
The chemical state of Zr during the initial, self-limiting stage of oxidation on single crystal zirconium (0001), with oxide thickness on the order of 1 nm, was probed by synchrotron x-ray photoelectron spectroscopy. Quantitative analysis of the Zr 3d spectrum by the spectrum reconstruction method demonstrated the formation of Zr1+, Zr2+, and Zr3+ as non-equilibrium oxidation states, in addition to Zr4+ in the stoichiometric ZrO2. This finding resolves the long-debated question of whether it is possible to form any valence states between Zr0 and Zr4+ at the metal-oxide interface. As a result, the presence of local strong electric fields and the minimization of interfacial energy are assessed and demonstrated as mechanisms that can drive the formation of these non-equilibrium valence states of Zr.
11. Equilibrium and non-equilibrium cluster phases in colloids with competing interactions.
PubMed
Mani, Ethayaraja; Lechner, Wolfgang; Kegel, Willem K; Bolhuis, Peter G
2014-07-01
The phase behavior of colloids that interact via competing interactions - short-range attraction and long-range repulsion - is studied by computer simulation. In particular, for a fixed strength and range of repulsion, the effect of the strength of an attractive interaction (ε) on the phase behavior is investigated at various colloid densities (ρ). A thermodynamically stable equilibrium colloidal cluster phase, consisting of compact crystalline clusters, is found below the fluid-solid coexistence line in the ε-ρ parameter space. The mean cluster size is found to linearly increase with the colloid density. At large ε and low densities, and at small ε and high densities, a non-equilibrium cluster phase, consisting of elongated Bernal spiral-like clusters, is observed. Although gelation can be induced either by increasing ε at constant density or vice versa, the gelation mechanism is different in either route. While in the ρ route gelation occurs via a glass transition of compact clusters, gelation in the ε route is characterized by percolation of elongated clusters. This study both provides the location of equilibrium and non-equilibrium cluster phases with respect to the fluid-solid coexistence, and reveals the dependencies of the gelation mechanism on the preparation route.
12. Hsp70 chaperones are non-equilibrium machines that achieve ultra-affinity by energy consumption.
PubMed
De Los Rios, Paolo; Barducci, Alessandro
2014-05-27
70-kDa Heat shock proteins are ATP-driven molecular chaperones that perform a myriad of essential cellular tasks. Although structural and biochemical studies have shed some light on their functional mechanism, the fundamental issue of the role of energy consumption, due to ATP-hydrolysis, has remained unaddressed. Here we establish a clear connection between the non-equilibrium nature of Hsp70, due to ATP hydrolysis, and the determining feature of its function, namely its high affinity for its substrates. Energy consumption can indeed decrease the dissociation constant of the chaperone-substrate complex by several orders of magnitude with respect to an equilibrium scenario. We find that the biochemical requirements for observing such ultra-affinity coincide with the physiological conditions in the cell. Our results rationalize several experimental observations and pave the way for further analysis of non-equilibrium effects underlying chaperone functions.DOI: http://dx.doi.org/10.7554/eLife.02218.001.
13. Potential and flux field landscape theory. II. Non-equilibrium thermodynamics of spatially inhomogeneous stochastic dynamical systems
SciTech Connect
Wu, Wei; Wang, Jin
2014-09-14
We have established a general non-equilibrium thermodynamic formalism consistently applicable to both spatially homogeneous and, more importantly, spatially inhomogeneous systems, governed by the Langevin and Fokker-Planck stochastic dynamics with multiple state transition mechanisms, using the potential-flux landscape framework as a bridge connecting stochastic dynamics with non-equilibrium thermodynamics. A set of non-equilibrium thermodynamic equations, quantifying the relations of the non-equilibrium entropy, entropy flow, entropy production, and other thermodynamic quantities, together with their specific expressions, is constructed from a set of dynamical decomposition equations associated with the potential-flux landscape framework. The flux velocity plays a pivotal role on both the dynamic and thermodynamic levels. On the dynamic level, it represents a dynamic force breaking detailed balance, entailing the dynamical decomposition equations. On the thermodynamic level, it represents a thermodynamic force generating entropy production, manifested in the non-equilibrium thermodynamic equations. The Ornstein-Uhlenbeck process and more specific examples, the spatial stochastic neuronal model, in particular, are studied to test and illustrate the general theory. This theoretical framework is particularly suitable to study the non-equilibrium (thermo)dynamics of spatially inhomogeneous systems abundant in nature. This paper is the second of a series.
14. Potential and flux field landscape theory. II. Non-equilibrium thermodynamics of spatially inhomogeneous stochastic dynamical systems
Wu, Wei; Wang, Jin
2014-09-01
We have established a general non-equilibrium thermodynamic formalism consistently applicable to both spatially homogeneous and, more importantly, spatially inhomogeneous systems, governed by the Langevin and Fokker-Planck stochastic dynamics with multiple state transition mechanisms, using the potential-flux landscape framework as a bridge connecting stochastic dynamics with non-equilibrium thermodynamics. A set of non-equilibrium thermodynamic equations, quantifying the relations of the non-equilibrium entropy, entropy flow, entropy production, and other thermodynamic quantities, together with their specific expressions, is constructed from a set of dynamical decomposition equations associated with the potential-flux landscape framework. The flux velocity plays a pivotal role on both the dynamic and thermodynamic levels. On the dynamic level, it represents a dynamic force breaking detailed balance, entailing the dynamical decomposition equations. On the thermodynamic level, it represents a thermodynamic force generating entropy production, manifested in the non-equilibrium thermodynamic equations. The Ornstein-Uhlenbeck process and more specific examples, the spatial stochastic neuronal model, in particular, are studied to test and illustrate the general theory. This theoretical framework is particularly suitable to study the non-equilibrium (thermo)dynamics of spatially inhomogeneous systems abundant in nature. This paper is the second of a series.
15. A contribution to non-equilibrium chemical kinetics. III. Some high-energy strongly non-equilibrium processes in solids and liquids
Temkin, A. Ya.
1989-10-01
The present work is the continuation of the previous works of the author on the non-equilibrium chemical kinetics. The consideration of direct and hot spot reactions provoked by the passage of fast particles through a liquid or solid medium is continued. It is shown that the model of quasi-particles permits us to detect and to consider a kinetic effect of primary fast particle reactions caused by the distribution of target molecules with respect to distance from the primary particle trajectory. It has been found what kinds of chemical kinetic experiments allow us to get rid of this effect to obtain correct values of the reaction elementary act parameters in the condensed phase. Spherical hot spot chemical kinetics of the reaction of two hot diatomic molecules is considered and compared with the one in cylindrical hot spots. It is shown that the creation of spherical hot spots can be stimulated by the addition of atoms having the mass close to that of the primary fast particle. In particular, this can be used to increase the selectivity of the radiation therapy by injection of such atoms to the tumor. Hot atom-polymer segment reaction kinetics in a cylindrical hot spot is considered. The obtained expressions for reaction product yields represent the hot spot contribution to polymer transformations by heavy fast ions. Their possible application to the DNA destruction by hot hydrogen atoms in a hot spot is discussed. Expressions for macroscopic yields of direct and hot spot reactions have been obtained. The hot spot evolution in the presence of laser radiation is considered. Various possibilities of fast particle and laser beams combining irradiation use are considered, especially for the laser material processing and metalworking as well as for the laser medicine.
16. Plasma-activated air mediates plasmid DNA delivery in vivo
PubMed Central
Edelblute, Chelsea M; Heller, Loree C; Malik, Muhammad A; Bulysheva, Anna; Heller, Richard
2016-01-01
Plasma-activated air (PAA) provides a noncontact DNA transfer platform. In the current study, PAA was used for the delivery of plasmid DNA in a 3D human skin model, as well as in vivo. Delivery of plasmid DNA encoding luciferase to recellularized dermal constructs was enhanced, resulting in a fourfold increase in luciferase expression over 120 hours compared to injection only (P < 0.05). Delivery of plasmid DNA encoding green fluorescent protein (GFP) was confirmed in the epidermal layers of the construct. In vivo experiments were performed in BALB/c mice, with skin as the delivery target. PAA exposure significantly enhanced luciferase expression levels 460-fold in exposed sites compared to levels obtained from the injection of plasmid DNA alone (P < 0.001). Expression levels were enhanced when the plasma reactor was positioned more distant from the injection site. Delivery of plasmid DNA encoding GFP to mouse skin was confirmed by immunostaining, where a 3-minute exposure at a 10 mm distance displayed delivery distribution deep within the dermal layers compared to an exposure at 3 mm where GFP expression was localized within the epidermis. Our findings suggest PAA-mediated delivery warrants further exploration as an alternative approach for DNA transfer for skin targets. PMID:27110584
17. Plasma-activated air mediates plasmid DNA delivery in vivo.
PubMed
Edelblute, Chelsea M; Heller, Loree C; Malik, Muhammad A; Bulysheva, Anna; Heller, Richard
2016-01-01
Plasma-activated air (PAA) provides a noncontact DNA transfer platform. In the current study, PAA was used for the delivery of plasmid DNA in a 3D human skin model, as well as in vivo. Delivery of plasmid DNA encoding luciferase to recellularized dermal constructs was enhanced, resulting in a fourfold increase in luciferase expression over 120 hours compared to injection only (P < 0.05). Delivery of plasmid DNA encoding green fluorescent protein (GFP) was confirmed in the epidermal layers of the construct. In vivo experiments were performed in BALB/c mice, with skin as the delivery target. PAA exposure significantly enhanced luciferase expression levels 460-fold in exposed sites compared to levels obtained from the injection of plasmid DNA alone (P < 0.001). Expression levels were enhanced when the plasma reactor was positioned more distant from the injection site. Delivery of plasmid DNA encoding GFP to mouse skin was confirmed by immunostaining, where a 3-minute exposure at a 10 mm distance displayed delivery distribution deep within the dermal layers compared to an exposure at 3 mm where GFP expression was localized within the epidermis. Our findings suggest PAA-mediated delivery warrants further exploration as an alternative approach for DNA transfer for skin targets. PMID:27110584
18. Cold atmospheric air plasma jet for medical applications
Kolb, Juergen F.; Price, Robert O.; Stacey, Michael; Swanson, R. James; Bowman, Angela; Chiavarini, Robert L.; Schoenbach, Karl H.
2008-10-01
By flowing ambient air through the discharge channel of a microhollow cathode geometry, we were able to sustain a stable 1.5-2 cm long afterglow plasma jet with dc voltages of only a few hundred volts. The temperature in this expelled afterglow plasma is close to room temperature. Emission spectra show atomic oxygen, hydroxyl ions and various nitrogen compounds. The low heavy-particle temperature allows us to use this exhaust stream on biological samples and tissues without thermal damage. The high levels of reactive species suggest an effective treatment for pathological skin conditions caused, in particular, by infectious agents. In first experiments, we have successfully tested the efficacy on Candida kefyr (a yeast), E.coli, and a matching E.coli strain-specific virus. All pathogens investigated responded well to the treatment. In the yeast case, complete eradication of the organism in the treated area could be achieved with an exposure of 90 seconds at a distance of 5 mm. A 10-fold increase of exposure, to 900 seconds caused no observable damage to murine integument.
19. Perturbative Calculation of Quasi-Potential in Non-equilibrium Diffusions: A Mean-Field Example
Bouchet, Freddy; Gawȩdzki, Krzysztof; Nardini, Cesare
2016-06-01
In stochastic systems with weak noise, the logarithm of the stationary distribution becomes proportional to a large deviation rate function called the quasi-potential. The quasi-potential, and its characterization through a variational problem, lies at the core of the Freidlin-Wentzell large deviations theory (Freidlin and Wentzell, Random perturbations of dynamical systems, 2012). In many interacting particle systems, the particle density is described by fluctuating hydrodynamics governed by Macroscopic Fluctuation Theory (Bertini et al., arXiv:1404.6466 , 2014), which formally fits within Freidlin-Wentzell's framework with a weak noise proportional to 1/√{N}, where N is the number of particles. The quasi-potential then appears as a natural generalization of the equilibrium free energy to non-equilibrium particle systems. A key physical and practical issue is to actually compute quasi-potentials from their variational characterization for non-equilibrium systems for which detailed balance does not hold. We discuss how to perform such a computation perturbatively in an external parameter λ , starting from a known quasi-potential for λ =0. In a general setup, explicit iterative formulae for all terms of the power-series expansion of the quasi-potential are given for the first time. The key point is a proof of solvability conditions that assure the existence of the perturbation expansion to all orders. We apply the perturbative approach to diffusive particles interacting through a mean-field potential. For such systems, the variational characterization of the quasi-potential was proven by Dawson and Gartner (Stochastics 20:247-308, 1987; Stochastic differential systems, vol 96, pp 1-10, 1987). Our perturbative analysis provides new explicit results about the quasi-potential and about fluctuations of one-particle observables in a simple example
20. Computational studies of thermal and quantum phase transitions approached through non-equilibrium quenching
Liu, Cheng-Wei
Phase transitions and their associated critical phenomena are of fundamental importance and play a crucial role in the development of statistical physics for both classical and quantum systems. Phase transitions embody diverse aspects of physics and also have numerous applications outside physics, e.g., in chemistry, biology, and combinatorial optimization problems in computer science. Many problems can be reduced to a system consisting of a large number of interacting agents, which under some circumstances (e.g., changes of external parameters) exhibit collective behavior; this type of scenario also underlies phase transitions. The theoretical understanding of equilibrium phase transitions was put on a solid footing with the establishment of the renormalization group. In contrast, non-equilibrium phase transition are relatively less understood and currently a very active research topic. One important milestone here is the Kibble-Zurek (KZ) mechanism, which provides a useful framework for describing a system with a transition point approached through a non-equilibrium quench process. I developed two efficient Monte Carlo techniques for studying phase transitions, one is for classical phase transition and the other is for quantum phase transitions, both are under the framework of KZ scaling. For classical phase transition, I develop a non-equilibrium quench (NEQ) simulation that can completely avoid the critical slowing down problem. For quantum phase transitions, I develop a new algorithm, named quasi-adiabatic quantum Monte Carlo (QAQMC) algorithm for studying quantum quenches. I demonstrate the utility of QAQMC quantum Ising model and obtain high-precision results at the transition point, in particular showing generalized dynamic scaling in the quantum system. To further extend the methods, I study more complex systems such as spin-glasses and random graphs. The techniques allow us to investigate the problems efficiently. From the classical perspective, using the
1. Common versus noble Bacillus subtilis differentially responds to air and argon gas plasma.
PubMed
Winter, Theresa; Bernhardt, Jörg; Winter, Jörn; Mäder, Ulrike; Schlüter, Rabea; Weltmann, Klaus-Dieter; Hecker, Michael; Kusch, Harald
2013-09-01
The applications of low-temperature plasma are not only confined to decontamination and sterilization but are also found in the medical field in terms of wound and skin treatment. For the improvement of already established and also for new plasma techniques, in-depth knowledge on the interactions between plasma and microorganism is essential. In an initial study, the interaction between growing Bacillus subtilis and argon plasma was investigated by using a growth chamber system suitable for low-temperature gas plasma treatment of bacteria in liquid medium. In this follow-up investigation, a second kind of plasma treatment-namely air plasma-was applied. With combined proteomic and transcriptomic analyses, we were able to investigate the plasma-specific stress response of B. subtilis toward not only argon but also air plasma. Besides an overlap of cellular responses due to both argon and air plasma treatment (DNA damage and oxidative stress), a variety of gas-dependent cellular responses such as growth retardation and morphological changes were observed. Only argon plasma treatments lead to a phosphate starvation response whereas air plasma induced the tryptophan operon implying damage by photooxidation. Biological findings were supported by the detection of reactive plasma species by optical emission spectroscopy and Fourier transformed infrared spectroscopy measurements.
2. Common versus noble Bacillus subtilis differentially responds to air and argon gas plasma.
PubMed
Winter, Theresa; Bernhardt, Jörg; Winter, Jörn; Mäder, Ulrike; Schlüter, Rabea; Weltmann, Klaus-Dieter; Hecker, Michael; Kusch, Harald
2013-09-01
The applications of low-temperature plasma are not only confined to decontamination and sterilization but are also found in the medical field in terms of wound and skin treatment. For the improvement of already established and also for new plasma techniques, in-depth knowledge on the interactions between plasma and microorganism is essential. In an initial study, the interaction between growing Bacillus subtilis and argon plasma was investigated by using a growth chamber system suitable for low-temperature gas plasma treatment of bacteria in liquid medium. In this follow-up investigation, a second kind of plasma treatment-namely air plasma-was applied. With combined proteomic and transcriptomic analyses, we were able to investigate the plasma-specific stress response of B. subtilis toward not only argon but also air plasma. Besides an overlap of cellular responses due to both argon and air plasma treatment (DNA damage and oxidative stress), a variety of gas-dependent cellular responses such as growth retardation and morphological changes were observed. Only argon plasma treatments lead to a phosphate starvation response whereas air plasma induced the tryptophan operon implying damage by photooxidation. Biological findings were supported by the detection of reactive plasma species by optical emission spectroscopy and Fourier transformed infrared spectroscopy measurements. PMID:23794223
3. Low dissipation in non-equilibrium control: sampling the ensemble of efficient protocols
Rotskoff, Grant; Gingrich, Todd; Crooks, Gavin; Geissler, Phillip
Designing schemes to efficiently control fluctuating, non-equilibrium systems is problem of fundamental importance and tremendous practical interest. A number of optimization techniques have proven fruitful in the pursuit of optimal control, but these approaches focus on the singular goal of finding the exact, optimal protocol. Here, we investigate the diversity of protocols that achieve low dissipation with a Monte Carlo path sampling algorithm. Akin to Boltzmann weighting configurations in Metropolis Monte Carlo, each protocol is exponentially biased by its mean dissipation. We show that the ensemble of low dissipation protocols can be sampled exactly in the Gaussian limit and that the method continues to robustly generate low dissipation protocols, even as the external control drives the system far from equilibrium.
4. An alternative order-parameter for non-equilibrium generalized spin models on honeycomb lattices
Sastre, Francisco; Henkel, Malte
2016-04-01
An alternative definition for the order-parameter is proposed, for a family of non-equilibrium spin models with up-down symmetry on honeycomb lattices, and which depends on two parameters. In contrast to the usual definition, our proposal takes into account that each site of the lattice can be associated with a local temperature which depends on the local environment of each site. Using the generalised voter motel as a test case, we analyse the phase diagram and the critical exponents in the stationary state and compare the results of the standard order-parameter with the ones following from our new proposal, on the honeycomb lattice. The stationary phase transition is in the Ising universality class. Finite-size corrections are also studied and the Wegner exponent is estimated as ω =1.06(9).
5. Collective Flocking Dynamics: Long Rang Order in a Non-Equilibrium 2D XY Model
Tu, Yuhai
1996-03-01
We propose and study a non-equilibrium continuum dynamical model for the collective motion of large groups of biological organisms (e.g., flocks of birds, slime molds, schools of fishs, etc.) (J. Toner and Y. Tu, Phys. Rev. Lett.), 75(23), 4326(1995) Our model becomes highly non-trivial, and different from the equilibrium model, for d
6. Processing and crystallographic structure of non-equilibrium Si-doped HfO{sub 2}
SciTech Connect
Hou, Dong; Fancher, Chris M.; Esteves, Giovanni; Jones, Jacob L.; Zhao, Lili
2015-06-28
Si-doped HfO{sub 2} was confirmed to exist as a non-equilibrium state. The crystallographic structures of Si-doped HfO{sub 2} were studied using high-resolution synchrotron X-ray diffraction and the Rietveld refinement method. Incorporation of Si into HfO{sub 2} and diffusion of Si out of (Hf,Si)O{sub 2} were determined as a function of calcination temperature. Higher thermal energy input at elevated calcination temperatures resulted in the formation of HfSiO{sub 4}, which is the expected major secondary phase in Si-doped HfO{sub 2}. The effect of SiO{sub 2} particle size (nano- and micron-sized) on the formation of Si-doped HfO{sub 2} was also determined. Nano-crystalline SiO{sub 2} was found to incorporate into HfO{sub 2} more readily.
7. Application of the non-equilibrium statistical operator method (NESOM) to dissipation atomic force microscopy
Mo, M. Y.; Kantorovich, L.
2001-02-01
We apply the non-equilibrium statistical operator method to non-contact atomic force microscopy, considering explicitly the statistical effects of (classical) vibrations of surface atoms and associated energy transfer from the tip to the surface. We derive several, physically and mathematically equivalent, forms of the equation of motion for the tip, each containing a friction term due to the so-called intrinsic mechanism of energy dissipation first suggested by Gauthier and Tsukada. Our exact treatment supports the results of some earlier work which were all approximate. We also demonstrate, using the same theory, that the distribution function of the tip in the coordinate-momentum phase subspace is governed by the Fokker-Planck equation and should be considered as strongly peaked around the exact values t and t of the momentum and the position of the tip, respectively.
8. Charge states of energetic tellurium ions: Equilibrium and non-equilibrium calculations
Kartavykh, Y.; Droege, W.; Klecker, B.; Kocharov, L.; Moebius, E.
2007-12-01
Recently, very high abundances of ultraheavy ions were observed in impulsive SEP events, compared to coronal abundances with enrichment factors of >100 for atomic mass > 100 amu. Because wave/particle interaction processes, as discussed for heavy ion enrichment and acceleration, depend critically on the mass per charge (M/Q) of the ions, an estimate of the ionic charge is very important for model calculations. In any realistic acceleration model one would have to use the ionization and recombination rates of these ions as a function of energy, because charge changing processes in the solar corona are inevitable and energy dependent. As an example of high mass ions, we calculate the equilibrium and non-equilibrium charge states for tellurium ions (Te, nuclear charge 52), and present a method to estimate the cross sections and rates for ionization and recombination of ions with arbitrary nuclear charge Z and atomic mass number A.
9. Quantum simulation of non-equilibrium dynamical maps with trapped ions
Schindler, Philipp; Müller, Markus; Nigg, Daniel; Monz, Thomas; Barreiro, Julio; Martinez, Esteban; Hennrich, Markus; Diehl, Sebastian; Zoller, Peter; Blatt, Rainer
2013-03-01
Dynamical maps are central for the understanding of general state transformations of physical systems. Prime examples include classical nonlinear systems undergoing transitions to chaos, or single particle quantum mechanical counterparts showing intriguing phenomena such as dynamical localization. Here, we extend the concept of dynamical maps to an open-system, many-particle context and experimentally explore the stroboscopic dynamics of a complex many-body spin model in a universal quantum simulator using up to five ions. We generate quantum mechanical long range order by an iteration of purely dissipative maps, reveal the characteristic features of a combined coherent and dissipative non-equilibrium evolution, and develop and implement various error detection and reduction techniques that will facilitate the faithful quantum simulation of larger systems.
10. Equilibrium and non-equilibrium dynamics simultaneously operate in the Galápagos islands.
PubMed
Valente, Luis M; Phillimore, Albert B; Etienne, Rampal S
2015-08-01
Island biotas emerge from the interplay between colonisation, speciation and extinction and are often the scene of spectacular adaptive radiations. A common assumption is that insular diversity is at a dynamic equilibrium, but for remote islands, such as Hawaii or Galápagos, this idea remains untested. Here, we reconstruct the temporal accumulation of terrestrial bird species of the Galápagos using a novel phylogenetic method that estimates rates of biota assembly for an entire community. We show that species richness on the archipelago is in an ascending phase and does not tend towards equilibrium. The majority of the avifauna diversifies at a slow rate, without detectable ecological limits. However, Darwin's finches form an exception: they rapidly reach a carrying capacity and subsequently follow a coalescent-like diversification process. Together, these results suggest that avian diversity of remote islands is rising, and challenge the mutual exclusivity of the non-equilibrium and equilibrium ecological paradigms.
11. Protein accumulation in the endoplasmic reticulum as a non-equilibrium phase transition.
PubMed
Budrikis, Zoe; Costantini, Giulio; La Porta, Caterina A M; Zapperi, Stefano
2014-01-01
Several neurological disorders are associated with the aggregation of aberrant proteins, often localized in intracellular organelles such as the endoplasmic reticulum. Here we study protein aggregation kinetics by mean-field reactions and three dimensional Monte carlo simulations of diffusion-limited aggregation of linear polymers in a confined space, representing the endoplasmic reticulum. By tuning the rates of protein production and degradation, we show that the system undergoes a non-equilibrium phase transition from a physiological phase with little or no polymer accumulation to a pathological phase characterized by persistent polymerization. A combination of external factors accumulating during the lifetime of a patient can thus slightly modify the phase transition control parameters, tipping the balance from a long symptomless lag phase to an accelerated pathological development. The model can be successfully used to interpret experimental data on amyloid-β clearance from the central nervous system. PMID:24722051
12. Protein accumulation in the endoplasmic reticulum as a non-equilibrium phase transition
PubMed Central
Budrikis, Zoe; Costantini, Giulio; La Porta, Caterina A. M.; Zapperi, Stefano
2014-01-01
Several neurological disorders are associated with the aggregation of aberrant proteins, often localized in intracellular organelles such as the endoplasmic reticulum. Here we study protein aggregation kinetics by mean-field reactions and three dimensional Monte carlo simulations of diffusion-limited aggregation of linear polymers in a confined space, representing the endoplasmic reticulum. By tuning the rates of protein production and degradation, we show that the system undergoes a non-equilibrium phase transition from a physiological phase with little or no polymer accumulation to a pathological phase characterized by persistent polymerization. A combination of external factors accumulating during the lifetime of a patient can thus slightly modify the phase transition control parameters, tipping the balance from a long symptomless lag phase to an accelerated pathological development. The model can be successfully used to interpret experimental data on amyloid-β clearance from the central nervous system. PMID:24722051
SciTech Connect
Philip, Bobby; Wang, Zhen; Berrill, Mark A; Rodriguez Rodriguez, Manuel; Pernice, Michael
2014-01-01
The time dependent non-equilibrium radiation diffusion equations are important for solving the transport of energy through radiation in optically thick regimes and find applications in several fields including astrophysics and inertial confinement fusion. The associated initial boundary value problems that are encountered exhibit a wide range of scales in space and time and are extremely challenging to solve. To efficiently and accurately simulate these systems we describe our research on combining techniques that will also find use more broadly for long term time integration of nonlinear multiphysics systems: implicit time integration for efficient long term time integration of stiff multiphysics systems, local control theory based step size control to minimize the required global number of time steps while controlling accuracy, dynamic 3D adaptive mesh refinement (AMR) to minimize memory and computational costs, Jacobian Free Newton Krylov methods on AMR grids for efficient nonlinear solution, and optimal multilevel preconditioner components that provide level independent linear solver convergence.
14. Non-equilibrium phase transition properties of disordered binary ferromagnetic alloy
Vatansever, Erol; Akinci, Umit; Polat, Hamza
2015-09-01
Non-equilibrium dynamic phase transition features of a disordered binary ferromagnetic alloy consisting of spin- 1 / 2 and spin-1 components under the presence of a time dependent oscillating magnetic field have been analyzed for a two dimensional square lattice. With the help of Glauber-type stochastic process, the kinetic equations of time dependent magnetizations have been derived based on the effective-field theory with single-site correlations. A systematic analysis for the whole range of the concentrations of randomly distributed components as well as other system parameters has been carried out. According to our numerical investigations, the considered system presents unusual thermal and magnetic field behaviors such as the existence of dynamic multi-critical behavior and also boundaries of the coexistence region, where both dynamically ordered and disordered phases overlap, sensitively depends on the studied parameter space.
15. Non-equilibrium 8π Josephson effect in atomic Kitaev wires
Laflamme, C.; Budich, J. C.; Zoller, P.; Dalmonte, M.
2016-08-01
The identification of fractionalized excitations, such as Majorana quasi-particles, would be a striking signal of the realization of exotic quantum states of matter. While the paramount demonstration of such excitations would be a probe of their non-Abelian statistics via controlled braiding operations, alternative proposals exist that may be easier to access experimentally. Here we identify a signature of Majorana quasi-particles, qualitatively different from the behaviour of a conventional superconductor, which can be detected in cold atom systems using alkaline-earth-like atoms. The system studied is a Kitaev wire interrupted by an extra site, which gives rise to super-exchange coupling between two Majorana-bound states. We show that this system hosts a tunable, non-equilibrium Josephson effect with a characteristic 8π periodicity of the Josephson current. The visibility of the 8π periodicity of the Josephson current is then studied including the effects of dephasing and particle losses.
16. Non-equilibrium 8π Josephson effect in atomic Kitaev wires
PubMed Central
Laflamme, C.; Budich, J. C.; Zoller, P.; Dalmonte, M.
2016-01-01
The identification of fractionalized excitations, such as Majorana quasi-particles, would be a striking signal of the realization of exotic quantum states of matter. While the paramount demonstration of such excitations would be a probe of their non-Abelian statistics via controlled braiding operations, alternative proposals exist that may be easier to access experimentally. Here we identify a signature of Majorana quasi-particles, qualitatively different from the behaviour of a conventional superconductor, which can be detected in cold atom systems using alkaline-earth-like atoms. The system studied is a Kitaev wire interrupted by an extra site, which gives rise to super-exchange coupling between two Majorana-bound states. We show that this system hosts a tunable, non-equilibrium Josephson effect with a characteristic 8π periodicity of the Josephson current. The visibility of the 8π periodicity of the Josephson current is then studied including the effects of dephasing and particle losses. PMID:27481540
17. Visualizing non-equilibrium lithiation of spinel oxide via in situ transmission electron microscopy
He, Kai; Zhang, Sen; Li, Jing; Yu, Xiqian; Meng, Qingping; Zhu, Yizhou; Hu, Enyuan; Sun, Ke; Yun, Hongseok; Yang, Xiao-Qing; Zhu, Yimei; Gan, Hong; Mo, Yifei; Stach, Eric A.; Murray, Christopher B.; Su, Dong
2016-05-01
Spinel transition metal oxides are important electrode materials for lithium-ion batteries, whose lithiation undergoes a two-step reaction, whereby intercalation and conversion occur in a sequential manner. These two reactions are known to have distinct reaction dynamics, but it is unclear how their kinetics affects the overall electrochemical response. Here we explore the lithiation of nanosized magnetite by employing a strain-sensitive, bright-field scanning transmission electron microscopy approach. This method allows direct, real-time, high-resolution visualization of how lithiation proceeds along specific reaction pathways. We find that the initial intercalation process follows a two-phase reaction sequence, whereas further lithiation leads to the coexistence of three distinct phases within single nanoparticles, which has not been previously reported to the best of our knowledge. We use phase-field theory to model and describe these non-equilibrium reaction pathways, and to directly correlate the observed phase evolution with the battery's discharge performance.
18. Entropy-based artificial viscosity stabilization for non-equilibrium Grey Radiation-Hydrodynamics
SciTech Connect
Delchini, Marc O. Ragusa, Jean C. Morel, Jim
2015-09-01
The entropy viscosity method is extended to the non-equilibrium Grey Radiation-Hydrodynamic equations. The method employs a viscous regularization to stabilize the numerical solution. The artificial viscosity coefficient is modulated by the entropy production and peaks at shock locations. The added dissipative terms are consistent with the entropy minimum principle. A new functional form of the entropy residual, suitable for the Radiation-Hydrodynamic equations, is derived. We demonstrate that the viscous regularization preserves the equilibrium diffusion limit. The equations are discretized with a standard Continuous Galerkin Finite Element Method and a fully implicit temporal integrator within the MOOSE multiphysics framework. The method of manufactured solutions is employed to demonstrate second-order accuracy in both the equilibrium diffusion and streaming limits. Several typical 1-D radiation-hydrodynamic test cases with shocks (from Mach 1.05 to Mach 50) are presented to establish the ability of the technique to capture and resolve shocks.
19. On the non-equilibrium dynamics of cavitation around the underwater projectile in variable motion
Chen, Y.; Lu, C. J.; Li, J.; Chen, X.; Gong, Z. X.
2015-12-01
In this work, the dynamic behavior of the non-equilibrium cavitation occurring around the underwater projectiles navigating with variable speed was numerically and theoretically investigated. The cavity collapse induced by the decelerating motion of the projectiles can be classified into two types: periodic oscillation and damped oscillation. In each type the evolution of the total mass of vapor in cavity are found to have strict correlation with the pressure oscillation in far field. By defining the equivalent radius of cavity, we introduce the specific kinetic energy of collapse and demonstrate that its change-rate is in good agreement with the pressure disturbance. We numerically investigated the influence of angle of attack on the collapse effect. The result shows that when the projectile decelerates, an asymmetric-focusing effect of the pressure induced by collapse occurs on its pressure side. We analytically explained such asymmetric-focusing effect.
20. Upwind MacCormack Euler solver with non-equilibrium chemistry
NASA Technical Reports Server (NTRS)
Sherer, Scott E.; Scott, James N.
1993-01-01
A computer code, designated UMPIRE, is currently under development to solve the Euler equations in two dimensions with non-equilibrium chemistry. UMPIRE employs an explicit MacCormack algorithm with dissipation introduced via Roe's flux-difference split upwind method. The code also has the capability to employ a point-implicit methodology for flows where stiffness is introduced through the chemical source term. A technique consisting of diagonal sweeps across the computational domain from each corner is presented, which is used to reduce storage and execution requirements. Results depicting one dimensional shock tube flow for both calorically perfect gas and thermally perfect, dissociating nitrogen are presented to verify current capabilities of the program. Also, computational results from a chemical reactor vessel with no fluid dynamic effects are presented to check the chemistry capability and to verify the point implicit strategy.
1. Modeling of DNA thermophoresis in dilute solutions using the non-equilibrium thermodynamics approach
2012-03-01
Our previous approach on thermodiffusion modeling of dilute polymer solutions is extended to dilute DNA solutions. The model is based on linear non-equilibrium thermodynamics and the concept of Eyring's activation energy of viscous flow to estimate the Soret coefficient in thermophoresis of macromolecules that are not in liquid phase. The net heat of transport of single- and double-stranded DNA molecules, which are in solid state, are replaced by the activation energy of viscous flow of liquid alkanes with comparable molecular weights. The proposed formula is tested against available experimental data and qualitative agreement is observed. For double-stranded DNA molecules, the experimental data are scattered and the model can qualitatively predict the data, whereas for single-stranded DNA experiments in the infinite dilution model, for which the model is prescribed, a very good agreement is observed.
2. Impurity-tuned non-equilibrium phase transition in a bacterial carpet
Hsiao, Yi-Teng; Wu, Kuan-Ting; Uchida, Nariya; Woon, Wei-Yen
2016-05-01
The effects of impurity on the non-equilibrium phase transition in Vibrio alginolyticus bacterial carpets are investigated through a position-sensitive-diode implemented optical tweezers-microsphere assay. The collective flow increases abruptly as we increase the rotation rate of flagella via Na+ concentration. The effects of impurities on the transition behavior are examined by mixing cells of a wild type strain (VIO5) with cells of a mutant strain (NMB136) in different swimming patterns. For dilute impurities, the transition point is shifted toward higher Na+ concentration. Increasing the impurities' ratio to over 0.25 leads to a significant drop in the collective force, suggesting a partial orientational order with a smaller correlation length.
3. Non-equilibrium physics and evolution—adaptation, extinction, and ecology: a Key Issues review
Kussell, E.; Vucelja, M.
2014-10-01
Evolutionary dynamics in nature constitute an immensely complex non-equilibrium process. We review the application of physical models of evolution, by focusing on adaptation, extinction, and ecology. In each case, we examine key concepts by working through examples. Adaptation is discussed in the context of bacterial evolution, with a view toward the relationship between growth rates, mutation rates, selection strength, and environmental changes. Extinction dynamics for an isolated population are reviewed, with emphasis on the relation between timescales of extinction, population size, and temporally correlated noise. Ecological models are discussed by focusing on the effect of spatial interspecies interactions on diversity. Connections between physical processes—such as diffusion, turbulence, and localization—and evolutionary phenomena are highlighted.
4. The Influence of Trapped Ions and Non-equilibrium EDF on Dust Particle Charging
SciTech Connect
Sukhinin, G. I.; Fedoseev, A. V.; Antipov, S. N.; Petrov, O. F.; Fortov, V. E.
2008-09-07
Dust particles charging in a low-pressure glow discharge was investigated theoretically with the help of model for trapped and free ions coupled with the self-consistent solution of Poisson equation for electric potential. Non-equilibrium (non-Maxwellian) character of electron energy distribution function depending on gas pressure and electric field was also taken into account on the basis of the solution of kinetic Boltzmann equation. The results were compared with the experimental measurements of dust particle charge depending on gas pressure. It was shown that the calculated effective charge, i.e. the difference of the dust particle charge and trapped ion charge, is in a fairly good agreement with the experimental data.
5. Non-equilibrium Green function method: theory and application in simulation of nanometer electronic devices
Do, Van-Nam
2014-09-01
We review fundamental aspects of the non-equilibrium Green function method in the simulation of nanometer electronic devices. The method is implemented into our recently developed computer package OPEDEVS to investigate transport properties of electrons in nano-scale devices and low-dimensional materials. Concretely, we present the definition of the four real-time Green functions, the retarded, advanced, lesser and greater functions. Basic relations among these functions and their equations of motion are also presented in detail as the basis for the performance of analytical and numerical calculations. In particular, we review in detail two recursive algorithms, which are implemented in OPEDEVS to solve the Green functions defined in finite-size opened systems and in the surface layer of semi-infinite homogeneous ones. Operation of the package is then illustrated through the simulation of the transport characteristics of a typical semiconductor device structure, the resonant tunneling diodes.
6. Gaussian-inspired auxiliary non-equilibrium thermostat (GIANT) for Dissipative Particle Dynamics simulations
Jamali, Safa; Boromand, Arman; Khani, Shaghayegh; Maia, Joao
2015-12-01
We present in this letter an auxiliary thermostat for non-equilibrium simulations in Dissipative Particle Dynamics based on the Gaussian distribution of particle velocities in the fluid. We demonstrate the ability of the thermostat to maintain the temperature under a wide range of shear rates and dissipative parameters, and to extend the shear rate window accessible by DPD significantly. The effect of proposed method on the viscosity of a DPD fluid is studied which is particularly of interest when the rheological behavior of a complex fluids is subject of DPD simulations. Furthermore, performance of the proposed method is compared to the ones from the well-known Lowe-Andersen scheme in regards to temperature and viscosity measurements.
7. Role of trap-induced scales in non-equilibrium dynamics of strongly interacting trapped bosons
Dutta, Anirban; Sensarma, Rajdeep; Sengupta, K.
2016-08-01
We use a time-dependent hopping expansion technique to study the non-equilibrium dynamics of strongly interacting bosons in an optical lattice in the presence of a harmonic trap characterized by a force constant K. We show that after a sudden quench of the hopping amplitude J across the superfluid (SF)-Mott insulator (MI) transition, the SF order parameter |{{Δ }\\mathbf{r}}(t)| and the local density fluctuation δ {{n}\\mathbf{r}}(t) exhibit sudden decoherence beyond a trap-induced time scale {{T}0}∼ {{K}-1/2} . We also show that after a slow linear ramp down of J, |{{Δ }\\mathbf{r}}| and the boson defect density {{P}\\mathbf{r}} display a novel non-monotonic spatial profile. Both these phenomena can be explained as consequences of trap-induced time and length scales affecting the dynamics and can be tested by concrete experiments.
8. Non-equilibrium critical properties of the Ising model on product graphs
Burioni, Raffaella; Corberi, Federico; Vezzani, Alessandro
2010-12-01
We study numerically the non-equilibrium critical properties of the Ising model defined on direct products of graphs, obtained from factor graphs without phase transition (Tc = 0). On this class of product graphs, the Ising model features a finite temperature phase transition, and we find a pattern of scaling behaviors analogous to the one known on regular lattices: observables take a scaling form in terms of a function L(t) of time, with the meaning of a growing length inside which a coherent fractal structure, the critical state, is progressively formed. Computing universal quantities, such as the critical exponents and the limiting fluctuation-dissipation ratio X_\\infty , allows us to comment on the possibility to extend universality concepts to the critical behavior on inhomogeneous substrates.
9. Non-equilibrium simulation of CH4 production through the depressurization method from gas hydrate reservoirs
2016-04-01
Natural gas hydrates (NGHs) in nature are formed from various hydrate formers (i.e. aqueous, gas, and adsorbed phases). As a result, due to Gibbs phase rule and the combined first and second laws of thermodynamics CH4-hydrate cannot reach thermodynamic equilibrium in real reservoir conditions. CH4 is the dominant component in NGH reservoirs. It is formed as a result of biogenic degradation of biological material in the upper few hundred meters of subsurface. It has been estimated that the amount of fuel-gas reserve in NGHs exceed the total amount of fossil fuel explored until today. Thus, these reservoirs have the potential to satisfy the energy requirements of the future. However, released CH4 from dissociated NGHs could find its way to the atmosphere and it is a far more aggressive greenhouse gas than CO2, even though its life-time is shorter. Lack of reliable field data makes it difficult to predict the production potential, as well as safety of CH4 production from NGHs. Computer simulations can be used as a tool to investigate CH4 production through different scenarios. Most hydrate simulators within academia and industry treat hydrate phase transitions as an equilibrium process and those which employ the kinetic approach utilize simple laboratory data in their models. Furthermore, it is typical to utilize a limited thermodynamic description where only temperature and pressure projections are considered. Another widely used simplification is to assume only a single route for the hydrate phase transitions. The non-equilibrium nature of hydrate indicates a need for proper kinetic models to describe hydrate dissociation and reformation in the reservoir with respect to thermodynamics variables, CH4 mole-fraction, pressure and temperature. The RetrasoCodeBright (RCB) hydrate simulator has previously been extended to model CH4-hydrate dissociation towards CH4 gas and water. CH4-hydrate is added to the RCB data-base as a pseudo mineral. Phase transitions are treated
10. Thermal Non-equilibrium Revealed by Periodic Pulses of Random Amplitudes in Solar Coronal Loops
Auchère, F.; Froment, C.; Bocchialini, K.; Buchlin, E.; Solomon, J.
2016-08-01
We recently detected variations in extreme ultraviolet intensity in coronal loops repeating with periods of several hours. Models of loops including stratified and quasi-steady heating predict the development of a state of thermal non-equilibrium (TNE): cycles of evaporative upflows at the footpoints followed by falling condensations at the apex. Based on Fourier and wavelet analysis, we demonstrate that the observed periodic signals are indeed not signatures of vibrational modes. Instead, superimposed on the power law expected from the stochastic background emission, the power spectra of the time series exhibit the discrete harmonics and continua expected from periodic trains of pulses of random amplitudes. These characteristics reinforce our earlier interpretation of these pulsations as being aborted TNE cycles.
11. Entropy analysis on non-equilibrium two-phase flow models
SciTech Connect
Karwat, H.; Ruan, Y.Q.
1995-09-01
A method of entropy analysis according to the second law of thermodynamics is proposed for the assessment of a class of practical non-equilibrium two-phase flow models. Entropy conditions are derived directly from a local instantaneous formulation for an arbitrary control volume of a structural two-phase fluid, which are finally expressed in terms of the averaged thermodynamic independent variables and their time derivatives as well as the boundary conditions for the volume. On the basis of a widely used thermal-hydraulic system code it is demonstrated with practical examples that entropy production rates in control volumes can be numerically quantified by using the data from the output data files. Entropy analysis using the proposed method is useful in identifying some potential problems in two-phase flow models and predictions as well as in studying the effects of some free parameters in closure relationships.
12. Non-equilibrium current cumulants and moments with a point-like defect
Mintchev, Mihail; Santoni, Luca; Sorba, Paul
2016-07-01
We derive the exact n-point current expectation values in the Landauer-Büttiker non-equilibrium steady state of a multi terminal system with star graph geometry and a point-like defect localised in the vertex. The current cumulants are extracted from the connected correlation functions and the cumulant generating function is established. We determine the moments, show that the associated moment problem has a unique solution and reconstruct explicitly the corresponding probability distribution. The basic building blocks of this distribution are the probabilities of particle emission and absorption from the heat reservoirs, driving the system away from equilibrium. We derive and analyse in detail these probabilities, showing that they fully describe the quantum transport problem in the system.
13. Equilibrium and non-equilibrium dynamics simultaneously operate in the Galápagos islands.
PubMed
Valente, Luis M; Phillimore, Albert B; Etienne, Rampal S
2015-08-01
Island biotas emerge from the interplay between colonisation, speciation and extinction and are often the scene of spectacular adaptive radiations. A common assumption is that insular diversity is at a dynamic equilibrium, but for remote islands, such as Hawaii or Galápagos, this idea remains untested. Here, we reconstruct the temporal accumulation of terrestrial bird species of the Galápagos using a novel phylogenetic method that estimates rates of biota assembly for an entire community. We show that species richness on the archipelago is in an ascending phase and does not tend towards equilibrium. The majority of the avifauna diversifies at a slow rate, without detectable ecological limits. However, Darwin's finches form an exception: they rapidly reach a carrying capacity and subsequently follow a coalescent-like diversification process. Together, these results suggest that avian diversity of remote islands is rising, and challenge the mutual exclusivity of the non-equilibrium and equilibrium ecological paradigms. PMID:26105791
14. Visualizing non-equilibrium lithiation of spinel oxide via in situ transmission electron microscopy.
PubMed
He, Kai; Zhang, Sen; Li, Jing; Yu, Xiqian; Meng, Qingping; Zhu, Yizhou; Hu, Enyuan; Sun, Ke; Yun, Hongseok; Yang, Xiao-Qing; Zhu, Yimei; Gan, Hong; Mo, Yifei; Stach, Eric A; Murray, Christopher B; Su, Dong
2016-01-01
Spinel transition metal oxides are important electrode materials for lithium-ion batteries, whose lithiation undergoes a two-step reaction, whereby intercalation and conversion occur in a sequential manner. These two reactions are known to have distinct reaction dynamics, but it is unclear how their kinetics affects the overall electrochemical response. Here we explore the lithiation of nanosized magnetite by employing a strain-sensitive, bright-field scanning transmission electron microscopy approach. This method allows direct, real-time, high-resolution visualization of how lithiation proceeds along specific reaction pathways. We find that the initial intercalation process follows a two-phase reaction sequence, whereas further lithiation leads to the coexistence of three distinct phases within single nanoparticles, which has not been previously reported to the best of our knowledge. We use phase-field theory to model and describe these non-equilibrium reaction pathways, and to directly correlate the observed phase evolution with the battery's discharge performance.
15. Accelerated self-replication under non-equilibrium, periodic energy delivery.
PubMed
Zhang, Rui; Walker, David A; Grzybowski, Bartosz A; Olvera de la Cruz, Monica
2014-01-01
Self-replication is a remarkable phenomenon in nature that has fascinated scientists for decades. In a self-replicating system, the original units are attracted to a template, which induce their binding. In equilibrium, the energy required to disassemble the newly assembled copy from the mother template is supplied by thermal energy. The possibility of optimizing self-replication was explored by controlling the frequency at which energy is supplied to the system. A model system inspired by a class of light-switchable colloids was considered where light is used to control the interactions. Conditions under which self-replication can be significantly more effective under non-equilibrium, cyclic energy delivery than under equilibrium constant energy conditions were identified. Optimal self-replication does not require constant energy expenditure. Instead, the proper timing at which energy is delivered to the system is an essential controllable parameter to induce high replication rates.
16. Interactions of Virus Like Particles in Equilibrium and Non-equilibrium Systems
Lin, Hsiang-Ku
This thesis summarizes my Ph.D. research on the interactions of virus like particles in equilibrium and non-equilibrium biological systems. In the equilibrium system, we studied the fluctuation-induced forces between inclusions in a fluid membrane. We developed an exact method to calculate thermal Casimir forces between inclusions of arbitrary shapes and separation, embedded in a fluid membrane whose fluctuations are governed by the combined action of surface tension, bending modulus, and Gaussian rigidity. Each objects shape and mechanical properties enter only through a characteristic matrix, a static analog of the scattering matrix. We calculate the Casimir interaction between two elastic disks embedded in a membrane. In particular, we find that at short separations the interaction is strong and independent of surface tension. In the non-equilibrium system, we studied the transport and deposition dynamics of colloids in saturated porous media under un-favorable filtering conditions. As an alternative to traditional convection-diffusion or more detailed numerical models, we consider a mean-field description in which the attachment and detachment processes are characterized by an entire spectrum of rate constants, ranging from shallow traps which mostly account for hydrodynamic dispersivity, all the way to the permanent traps associated with physical straining. The model has an analytical solution which allows analysis of its properties including the long time asymptotic behavior and the profile of the deposition curves. Furthermore, the model gives rise to a filtering front whose structure, stability and propagation velocity are examined. Based on these results, we propose an experimental protocol to determine the parameters of the model.
17. Error suppression and error correction in adiabatic quantum computation: non-equilibrium dynamics
Sarovar, Mohan; Young, Kevin C.
2013-12-01
While adiabatic quantum computing (AQC) has some robustness to noise and decoherence, it is widely believed that encoding, error suppression and error correction will be required to scale AQC to large problem sizes. Previous works have established at least two different techniques for error suppression in AQC. In this paper we derive a model for describing the dynamics of encoded AQC and show that previous constructions for error suppression can be unified with this dynamical model. In addition, the model clarifies the mechanisms of error suppression and allows the identification of its weaknesses. In the second half of the paper, we utilize our description of non-equilibrium dynamics in encoded AQC to construct methods for error correction in AQC by cooling local degrees of freedom (qubits). While this is shown to be possible in principle, we also identify the key challenge to this approach: the requirement of high-weight Hamiltonians. Finally, we use our dynamical model to perform a simplified thermal stability analysis of concatenated-stabilizer-code encoded many-body systems for AQC or quantum memories. This work is a companion paper to ‘Error suppression and error correction in adiabatic quantum computation: techniques and challenges (2013 Phys. Rev. X 3 041013)’, which provides a quantum information perspective on the techniques and limitations of error suppression and correction in AQC. In this paper we couch the same results within a dynamical framework, which allows for a detailed analysis of the non-equilibrium dynamics of error suppression and correction in encoded AQC.
18. Non-equilibrium steady states in the Klein-Gordon theory
Doyon, Benjamin; Lucas, Andrew; Schalm, Koenraad; Bhaseen, M. J.
2015-03-01
We construct non-equilibrium steady states in the Klein-Gordon theory in arbitrary space dimension d following a local quench. We consider the approach where two independently thermalized semi-infinite systems, with temperatures {{T}L} and {{T}R}, are connected along a d-1-dimensional hypersurface. A current-carrying steady state, described by thermally distributed modes with temperatures {{T}L} and {{T}R} for left and right-moving modes, respectively, emerges at late times. The non-equilibrium density matrix is the exponential of a non-local conserved charge. We obtain exact results for the average energy current and the complete distribution of energy current fluctuations. The latter shows that the long-time energy transfer can be described by a continuum of independent Poisson processes, for which we provide the exact weights. We further describe the full time evolution of local observables following the quench. Averages of generic local observables, including the stress-energy tensor, approach the steady state with a power-law in time, where the exponent depends on the initial conditions at the connection hypersurface. We describe boundary conditions and special operators for which the steady state is reached instantaneously on the connection hypersurface. A semiclassical analysis of freely propagating modes yields the average energy current at large distances and late times. We conclude by comparing and contrasting our findings with results for interacting theories and provide an estimate for the timescale governing the crossover to hydrodynamics. As a modification of our Klein-Gordon analysis we also include exact results for free Dirac fermions.
19. Non-Equilibrium Zeldovich-Von Neumann-Doring Theory and Reactive Flow Modeling of Detonation
SciTech Connect
Tarver, C M; Forbes, J W; Urtiew, P A
2002-05-02
This paper discusses the Non-Equilibrium Zeldovich - von Neumann - Doring (NEZND) theory of self-sustaining detonation waves and the Ignition and Growth reactive flow model of shock initiation and detonation wave propagation in solid explosives. The NEZND theory identified the non-equilibrium excitation processes that precede and follow the exothermic decomposition of a large high explosive molecule into several small reaction product molecules. The thermal energy deposited by the leading shock wave must be distributed to the vibrational modes of the explosive molecule before chemical reactions can occur. The induction time for the onset of the initial endothermic reactions can be calculated using high pressure, high temperature transition state theory. Since the chemical energy is released well behind the leading shock front of a detonation wave, a physical mechanism is required for this chemical energy to reinforce the leading shock front and maintain its overall constant velocity. This mechanism is the amplification of pressure wavelets in the reaction zone by the process of de-excitation of the initially highly vibrationally excited reaction product molecules. This process leads to the development of the three-dimensional structure of detonation waves observed for all explosives. For practical predictions of shock initiation and detonation in hydrodynamic codes, phenomenological reactive flow models have been developed. The Ignition and Growth reactive flow model of shock initiation and detonation in solid explosives has been very successful in describing the overall flow measured by embedded gauges and laser interferometry. This reactive flow model uses pressure and compression dependent reaction rates, because time resolved experimental temperature data is not yet available. Since all chemical reaction rates are ultimately controlled by temperature, the next generation of reactive flow models will use temperature dependent reaction rates. Progress on a
20. Microscopic Simulation and Macroscopic Modeling for Thermal and Chemical Non-Equilibrium
NASA Technical Reports Server (NTRS)
Liu, Yen; Panesi, Marco; Vinokur, Marcel; Clarke, Peter
2013-01-01
This paper deals with the accurate microscopic simulation and macroscopic modeling of extreme non-equilibrium phenomena, such as encountered during hypersonic entry into a planetary atmosphere. The state-to-state microscopic equations involving internal excitation, de-excitation, dissociation, and recombination of nitrogen molecules due to collisions with nitrogen atoms are solved time-accurately. Strategies to increase the numerical efficiency are discussed. The problem is then modeled using a few macroscopic variables. The model is based on reconstructions of the state distribution function using the maximum entropy principle. The internal energy space is subdivided into multiple groups in order to better describe the non-equilibrium gases. The method of weighted residuals is applied to the microscopic equations to obtain macroscopic moment equations and rate coefficients. The modeling is completely physics-based, and its accuracy depends only on the assumed expression of the state distribution function and the number of groups used. The model makes no assumption at the microscopic level, and all possible collisional and radiative processes are allowed. The model is applicable to both atoms and molecules and their ions. Several limiting cases are presented to show that the model recovers the classical twotemperature models if all states are in one group and the model reduces to the microscopic equations if each group contains only one state. Numerical examples and model validations are carried out for both the uniform and linear distributions. Results show that the original over nine thousand microscopic equations can be reduced to 2 macroscopic equations using 1 to 5 groups with excellent agreement. The computer time is decreased from 18 hours to less than 1 second.
1. Cosmological QCD phase transition in steady non-equilibrium dissipative Hořava–Lifshitz early universe
SciTech Connect
2014-07-15
We study the phase transition from quark–gluon plasma to hadrons in the early universe in the context of non-equilibrium thermodynamics. According to the standard model of cosmology, a phase transition associated with chiral symmetry breaking after the electro-weak transition has occurred when the universe was about 1–10 μs old. We focus attention on such a phase transition in the presence of a viscous relativistic cosmological background fluid in the framework of non-detailed balance Hořava–Lifshitz cosmology within an effective model of QCD. We consider a flat Friedmann–Robertson–Walker universe filled with a non-causal and a causal bulk viscous cosmological fluid respectively and investigate the effects of the running coupling constants of Hořava–Lifshitz gravity, λ, on the evolution of the physical quantities relevant to a description of the early universe, namely, the temperature T, scale factor a, deceleration parameter q and dimensionless ratio of the bulk viscosity coefficient to entropy density (ξ)/s . We assume that the bulk viscosity cosmological background fluid obeys the evolution equation of the steady truncated (Eckart) and full version of the Israel–Stewart fluid, respectively. -- Highlights: •In this paper we have studied quark–hadron phase transition in the early universe in the context of the Hořava–Lifshitz model. •We use a flat FRW universe with the bulk viscosity cosmological background fluid obeying the evolution equation of the steady truncated (Eckart) and full version of the Israel–Stewart fluid, respectively.
2. Properties of thermal air plasma with admixing of copper and carbon
Fesenko, S.; Veklich, A.; Boretskij, V.; Cressault, Y.; Gleizes, A.; Teulet, Ph
2014-11-01
This paper deals with investigations of air plasma with admixing of copper and carbon. Model plasma source unit with real breaking arc was used for the simulation of real discharges, which can be occurred during sliding of Cu-C composite electrodes on copper wire at electromotive vehicles. The complex technique of plasma property studies is developed. From one hand, the radial profiles of temperature and electron density in plasma of electric arc discharge in air between Cu-C composite and copper electrodes in air flow were measured by optical spectroscopy techniques. From another hand, the radial profiles of electric conductivity of plasma mixture were calculated by solution of energy balance equation. It was assumed that the thermal conductivity of air plasma is not depending on copper or carbon vapor admixtures. The electron density is obtained from electric conductivity profiles by calculation in assumption of local thermodynamic equilibrium in plasma. Computed in such way radial profiles of electron density in plasma of electric arc discharge in air between copper electrodes were compared with experimentally measured profiles. It is concluded that developed techniques of plasma diagnostics can be reasonably used in investigations of thermal plasma with copper and carbon vapors.
3. Direct measurement of the Einstein relation in a macroscopic, non-equilibrium system of chaotic surface waves
Welch, Kyle; Liebman-Pelaez, Alexander; Corwin, Eric
Equilibrium statistical mechanics is traditionally limited to thermal systems. Can it be applied to athermal, non-equilibrium systems that nonetheless satisfy the basic criteria of steady-state chaos and isotropy? We answer this question using a macroscopic system of chaotic surface waves which is, by all measures, non-equilibrium. The waves are generated in a dish of water that is vertically oscillated above a critical amplitude. We have constructed a rheometer that actively measures the drag imparted by the waves on a buoyant particle, a quantity entirely divorced in origin from the drag imparted by the fluid in which the particle floats. We also perform a separate, passive measurement, extracting a diffusion constant and effective temperature. Having directly measured all three properties (temperature, diffusion constant, and drag coefficient) we go on to show that our macroscopic, non-equilibrium case is wholly consistent with the Einstein relation, a classic result for equilibrium thermal systems.
4. Heat Transfer and Fluid Transport of Supercritical CO2 in Enhanced Geothermal System with Local Thermal Non-equilibrium Model
DOE PAGESBeta
Zhang, Le; Luo, Feng; Xu, Ruina; Jiang, Peixue; Liu, Huihai
2014-12-31
The heat transfer and fluid transport of supercritical CO2 in enhanced geothermal system (EGS) is studied numerically with local thermal non-equilibrium model, which accounts for the temperature difference between solid matrix and fluid components in porous media and uses two energy equations to describe heat transfer in the solid matrix and in the fluid, respectively. As compared with the previous results of our research group, the effect of local thermal non-equilibrium mainly depends on the volumetric heat transfer coefficient ah, which has a significant effect on the production temperature at reservoir outlet and thermal breakthrough time. The uniformity of volumetricmore » heat transfer coefficient ah has little influence on the thermal breakthrough time, but the temperature difference become more obvious with time after thermal breakthrough with this simulation model. The thermal breakthrough time reduces and the effect of local thermal non-equilibrium becomes significant with decreasing ah.« less
5. "Non-equilibrium" block copolymer micelles with glassy cores: a predictive approach based on theory of equilibrium micelles.
PubMed
Nagarajan, Ramanathan
2015-07-01
Micelles generated in water from most amphiphilic block copolymers are widely recognized to be non-equilibrium structures. Typically, the micelles are prepared by a kinetic process, first allowing molecular scale dissolution of the block copolymer in a common solvent that likes both the blocks and then gradually replacing the common solvent by water to promote the hydrophobic blocks to aggregate and create the micelles. The non-equilibrium nature of the micelle originates from the fact that dynamic exchange between the block copolymer molecules in the micelle and the singly dispersed block copolymer molecules in water is suppressed, because of the glassy nature of the core forming polymer block and/or its very large hydrophobicity. Although most amphiphilic block copolymers generate such non-equilibrium micelles, no theoretical approach to a priori predict the micelle characteristics currently exists. In this work, we propose a predictive approach for non-equilibrium micelles with glassy cores by applying the equilibrium theory of micelles in two steps. In the first, we calculate the properties of micelles formed in the mixed solvent while true equilibrium prevails, until the micelle core becomes glassy. In the second step, we freeze the micelle aggregation number at this glassy state and calculate the corona dimension from the equilibrium theory of micelles. The condition when the micelle core becomes glassy is independently determined from a statistical thermodynamic treatment of diluent effect on polymer glass transition temperature. The predictions based on this "non-equilibrium" model compare reasonably well with experimental data for polystyrene-polyethylene oxide diblock copolymer, which is the most extensively studied system in the literature. In contrast, the application of the equilibrium model to describe such a system significantly overpredicts the micelle core and corona dimensions and the aggregation number. The non-equilibrium model suggests ways to
6. The effects of metallicity, UV radiation and non-equilibrium chemistry in high-resolution simulations of galaxies
Richings, A. J.; Schaye, Joop
2016-05-01
We present a series of hydrodynamic simulations of isolated galaxies with stellar mass of 109 M⊙. The models use a resolution of 750 M⊙ per particle and include a treatment for the full non-equilibrium chemical evolution of ions and molecules (157 species in total), along with gas cooling rates computed self-consistently using the non-equilibrium abundances. We compare these to simulations evolved using cooling rates calculated assuming chemical (including ionization) equilibrium, and we consider a wide range of metallicities and UV radiation fields, including a local prescription for self-shielding by gas and dust. We find higher star formation rates and stronger outflows at higher metallicity and for weaker radiation fields, as gas can more easily cool to a cold (few hundred Kelvin) star-forming phase under such conditions. Contrary to variations in the metallicity and the radiation field, non-equilibrium chemistry generally has no strong effect on the total star formation rates or outflow properties. However, it is important for modelling molecular outflows. For example, the mass of H2 outflowing with velocities {>}50 {km} {s}^{-1} is enhanced by a factor ˜20 in non-equilibrium. We also compute the observable line emission from C II and CO. Both are stronger at higher metallicity, while C II and CO emission are higher for stronger and weaker radiation fields, respectively. We find that C II is generally unaffected by non-equilibrium chemistry. However, emission from CO varies by a factor of ˜2-4. This has implications for the mean XCO conversion factor between CO emission and H2 column density, which we find is lowered by up to a factor ˜2.3 in non-equilibrium, and for the fraction of CO-dark molecular gas.
7. Non-thermal plasma for air and water remediation.
PubMed
Hashim, Siti Aiasah; Samsudin, Farah Nadia Dayana Binti; Wong, Chiow San; Abu Bakar, Khomsaton; Yap, Seong Ling; Mohd Zin, Mohd Faiz
2016-09-01
A modular typed dielectric barrier discharge (DBD) device is designed and tested for air and water remediation. The module is made of a number of DBD tubes that can be arranged in series or parallel. Each of the DBD tubes comprises inner electrode enclosed with dielectric barrier and arranged as such to provide a gap for the passage of gases. Non-thermal plasma generated in the gap effectively creates gaseous chemical reactions. Its efficacy in the remediation of gas stream containing high NOx, similar to diesel emission and wastewater containing latex, are presented. A six tubes DBD module has successfully removed more than 80% of nitric oxide from the gas stream. In another arrangement, oxygen was fed into a two tubes DBD to generate ozone for treatment of wastewater. Samples of wastewater were collected from a treatment pond of a rubber vulcanization pilot plant. The water pollution load was evaluated by the chemical oxygen demand (COD) and biological oxygen demand (BOD5) values. Preliminary results showed some improvement (about 13%) on the COD after treatment and at the same time had increased the BOD5 by 42%. This results in higher BOD5/COD ratio after ozonation which indicate better biodegradability of the wastewater.
8. Non-thermal plasma for air and water remediation.
PubMed
Hashim, Siti Aiasah; Samsudin, Farah Nadia Dayana Binti; Wong, Chiow San; Abu Bakar, Khomsaton; Yap, Seong Ling; Mohd Zin, Mohd Faiz
2016-09-01
A modular typed dielectric barrier discharge (DBD) device is designed and tested for air and water remediation. The module is made of a number of DBD tubes that can be arranged in series or parallel. Each of the DBD tubes comprises inner electrode enclosed with dielectric barrier and arranged as such to provide a gap for the passage of gases. Non-thermal plasma generated in the gap effectively creates gaseous chemical reactions. Its efficacy in the remediation of gas stream containing high NOx, similar to diesel emission and wastewater containing latex, are presented. A six tubes DBD module has successfully removed more than 80% of nitric oxide from the gas stream. In another arrangement, oxygen was fed into a two tubes DBD to generate ozone for treatment of wastewater. Samples of wastewater were collected from a treatment pond of a rubber vulcanization pilot plant. The water pollution load was evaluated by the chemical oxygen demand (COD) and biological oxygen demand (BOD5) values. Preliminary results showed some improvement (about 13%) on the COD after treatment and at the same time had increased the BOD5 by 42%. This results in higher BOD5/COD ratio after ozonation which indicate better biodegradability of the wastewater. PMID:27056469
9. Modification of polysulfone porous hollow fiber membranes by air plasma treatment
Volkov, V. V.; Ibragimov, R. G.; Abdullin, I. Sh; Gallyamov, R. T.; Ovcharova, A. A.; Bildyukevich, A. V.
2016-09-01
Air plasma treatment was used to enhance the surface hydrophilic properties of the polysulfone porous hollow fiber membranes prepared via a dry-wet phase invertion technique in the free spinning mode in air. Membranes prepared had porous asymmetric structure with macroporous support on the shell side and fine-porous selective layer on the lumen side. The wettability of the inner membrane surfaces were checked by contact angle measurements and FTIR was used to compare the surfaces before and after plasma treatment. Membrane morphology was examined with confocal scanning laser microscopy (CSLM). Contact angle measurements confirm that air plasma treatment affords improvement in the wettability of polysulfone membranes and FTIR results show that air plasmas chemically modify the lumen side membrane surface, however, there is no significant change in membranes chemical structure after modification. CSLM data obtained, as well as gas permeability (He and CO2) measurements show that after plasma treatment pore etching occurs.
10. Air plasma processing of poly(methyl methacrylate) micro-beads: Surface characterisations
Liu, Chaozong; Cui, Nai-Yi; Osbeck, Susan; Liang, He
2012-10-01
This paper reports the surface processing of poly(methyl methacrylate) (PMMA) micro-beads by using a rotary air plasma reactor, and its effects on surface properties. The surface properties, including surface wettability, surface chemistry and textures of the PMMA beads, were characterised. It was observed that the air plasma processing can improve the surface wettability of the PMMA microbeads significantly. A 15 min plasma processing can reduce the surface water contact angle of PMMA beads to about 50° from its original value of 80.3°. This was accompanied by about 8% increase in surface oxygen concentration as confirmed by XPS analysis. The optical profilometry examination revealed the air plasma processing resulted in a rougher surface that has a “delicate” surface texture. It is concluded that the surface chemistry and texture, induced by air plasma processing, co-contributed to the surface wettability improvement of PMMA micro-beads.
11. [The correction to spectroscopic diagnostics of plasma jet with air engulfment].
PubMed
Zhao, Wen-hua; Tang, Huang-zai; Tian, Kuo; Zhang, Guan-zhong
2004-04-01
A high-resolution, multi-line spectroscopic diagnostic system was used to detect two spectral line intensities in plasma jet simultaneously. The temperature profiles of an arc plasma jet issued into atmosphere and the concentrations of the air engulfment in the plasma jet were experimentally determined by means of the line absolute intensity method in this paper. The temperature profiles were obtained in two cases: the air engulfment in the plasma jet being considered and not being considered. The comparison of temperatures obtained in these two cases illustrates that the air engulfment in the plasma jet has considerable influence on spectroscopic diagnostic results. The neglect of the air engulfment brings on error in the temperature diagnostics with the absolute line intensity method. Especially in the region far away from the exit of the nozzle, the error is obvious.
12. Non-linear quantum-classical scheme to simulate non-equilibrium strongly correlated fermionic many-body dynamics.
PubMed
Kreula, J M; Clark, S R; Jaksch, D
2016-01-01
We propose a non-linear, hybrid quantum-classical scheme for simulating non-equilibrium dynamics of strongly correlated fermions described by the Hubbard model in a Bethe lattice in the thermodynamic limit. Our scheme implements non-equilibrium dynamical mean field theory (DMFT) and uses a digital quantum simulator to solve a quantum impurity problem whose parameters are iterated to self-consistency via a classically computed feedback loop where quantum gate errors can be partly accounted for. We analyse the performance of the scheme in an example case.
13. Non-linear quantum-classical scheme to simulate non-equilibrium strongly correlated fermionic many-body dynamics
PubMed Central
Kreula, J. M.; Clark, S. R.; Jaksch, D.
2016-01-01
We propose a non-linear, hybrid quantum-classical scheme for simulating non-equilibrium dynamics of strongly correlated fermions described by the Hubbard model in a Bethe lattice in the thermodynamic limit. Our scheme implements non-equilibrium dynamical mean field theory (DMFT) and uses a digital quantum simulator to solve a quantum impurity problem whose parameters are iterated to self-consistency via a classically computed feedback loop where quantum gate errors can be partly accounted for. We analyse the performance of the scheme in an example case. PMID:27609673
14. Non-linear quantum-classical scheme to simulate non-equilibrium strongly correlated fermionic many-body dynamics.
PubMed
Kreula, J M; Clark, S R; Jaksch, D
2016-01-01
We propose a non-linear, hybrid quantum-classical scheme for simulating non-equilibrium dynamics of strongly correlated fermions described by the Hubbard model in a Bethe lattice in the thermodynamic limit. Our scheme implements non-equilibrium dynamical mean field theory (DMFT) and uses a digital quantum simulator to solve a quantum impurity problem whose parameters are iterated to self-consistency via a classically computed feedback loop where quantum gate errors can be partly accounted for. We analyse the performance of the scheme in an example case. PMID:27609673
15. Non-linear quantum-classical scheme to simulate non-equilibrium strongly correlated fermionic many-body dynamics
Kreula, J. M.; Clark, S. R.; Jaksch, D.
2016-09-01
We propose a non-linear, hybrid quantum-classical scheme for simulating non-equilibrium dynamics of strongly correlated fermions described by the Hubbard model in a Bethe lattice in the thermodynamic limit. Our scheme implements non-equilibrium dynamical mean field theory (DMFT) and uses a digital quantum simulator to solve a quantum impurity problem whose parameters are iterated to self-consistency via a classically computed feedback loop where quantum gate errors can be partly accounted for. We analyse the performance of the scheme in an example case.
16. PREFACE: Fourh Workshop on Non-Equilibrium Phenomena in Supercooled Fluids, Glasses and Amorphous Materials
Andreozzi, Laura; Giordano, Marco; Leporini, Dino; Tosi, Mario
2007-04-01
This special issue of Journal of Physics: Condensed Matter presents the Proceedings of the Fourh Workshop on Non-Equilibrium Phenomena in Supercooled Fluids, Glasses and Amorphous Materials, held in Pisa from 17-22 September 2006. This was the fourth of a series of workshops on this theme started in 1995 as a joint initiative of the Università di Pisa and the Scuola Normale Superiore. The 2006 edition was attended by about 200 participants from Europe, Asia and the Americas. As for the earlier workshops, the main objective was to bring together scientists from different areas of science, technology and engineering, to comparatively discuss experimental facts and theoretical predictions on the dynamical processes that occur in supercooled fluids and other disordered materials in non-equilibrium states. The underlying conceptual unity of the field provides a common background for the scientific community working in its various areas. In this edition the number of sessions was increased to cover a wider range of topics of general and current interest, in a larger number of stimulating lectures. The core of the workshop was a set of general lectures followed by more specific presentations on current issues in the main areas of the field. The sessions were in sequence devoted to: non-equilibrium dynamics, aging and secondary relaxations, biomaterials, polyamorphism and water, polymer dynamics I, complex systems, pressure-temperature scaling, thin films, nanometre length-scale studies, folded states of proteins and polymer crystals, theoretical aspects and energy landscape approaches, relaxation and heterogeneous dynamics, rheology in fluids and entangled polymers, biopolymers, and polymer dynamics II. We thank the session chairmen and all speakers for the high quality of their contributions. The structure of this issue of the proceedings follows the sequence of the oral presentations in the workshop, complemented by some papers selected from the poster sessions. Two
17. Theory of non-equilibrium force measurements involving deformable drops and bubbles.
PubMed
Chan, Derek Y C; Klaseboer, Evert; Manica, Rogerio
2011-07-11
Over the past decade, direct force measurements using the Atomic Force Microscope (AFM) have been extended to study non-equilibrium interactions. Perhaps the more scientifically interesting and technically challenging of such studies involved deformable drops and bubbles in relative motion. The scientific interest stems from the rich complexity that arises from the combination of separation dependent surface forces such as Van der Waals, electrical double layer and steric interactions with velocity dependent forces from hydrodynamic interactions. Moreover the effects of these forces also depend on the deformations of the surfaces of the drops and bubbles that alter local conditions on the nanometer scale, with deformations that can extend over micrometers. Because of incompressibility, effects of such deformations are strongly influenced by small changes of the sizes of the drops and bubbles that may be in the millimeter range. Our focus is on interactions between emulsion drops and bubbles at around 100 μm size range. At the typical velocities in dynamic force measurements with the AFM which span the range of Brownian velocities of such emulsions, the ratio of hydrodynamic force to surface tension force, as characterized by the capillary number, is ~10(-6) or smaller, which poses challenges to modeling using direct numerical simulations. However, the qualitative and quantitative features of the dynamic forces between interacting drops and bubbles are sensitive to the detailed space and time-dependent deformations. It is this dynamic coupling between forces and deformations that requires a detailed quantitative theoretical framework to help interpret experimental measurements. Theories that do not treat forces and deformations in a consistent way simply will not have much predictive power. The technical challenges of undertaking force measurements are substantial. These range from generating drop and bubble of the appropriate size range to controlling the
18. Thermodynamic and Transport Properties of Real Air Plasma in Wide Range of Temperature and Pressure
Wang, Chunlin; Wu, Yi; Chen, Zhexin; Yang, Fei; Feng, Ying; Rong, Mingzhe; Zhang, Hantian
2016-07-01
Air plasma has been widely applied in industrial manufacture. In this paper, both dry and humid air plasmas' thermodynamic and transport properties are calculated in temperature 300-100000 K and pressure 0.1-100 atm. To build a more precise model of real air plasma, over 70 species are considered for composition. Two different methods, the Gibbs free energy minimization method and the mass action law method, are used to determinate the composition of the air plasma in a different temperature range. For the transport coefficients, the simplified Chapman-Enskog method developed by Devoto has been applied using the most recent collision integrals. It is found that the presence of CO2 has almost no effect on the properties of air plasma. The influence of H2O can be ignored except in low pressure air plasma, in which the saturated vapor pressure is relatively high. The results will serve as credible inputs for computational simulation of air plasma. supported by the National Key Basic Research Program of China (973 Program)(No. 2015CB251002), National Natural Science Foundation of China (Nos. 51521065, 51577145), the Science and Technology Project Funds of the Grid State Corporation (SGTYHT/13-JS-177), the Fundamental Research Funds for the Central Universities, and State Grid Corporation Project (GY71-14-004)
19. Effects of Atmospheric Air Plasma Irradiation on pH of Water
Sarinont, Thapanut; Koga, Kazunori; Kitazaki, Satoshi; Uchida, Giichirou; Hayashi, Nobuya; Shiratani, Masaharu
We have studied the effects of atmospheric air plasma irradiation to water using a scalable dielectric barrier discharge device. Measurements of the pH of water treated by the plasmas have shown the pH decreases due to peroxide molecules generated by plasma irradiation and depends on material of water container. We also found this plasma treated water has little effect on the growth enhancement on Radish sprouts compare with plasma irradiation on dry seeds and the plasma irradiation can affect them through the water buffer of 0.2 mm in thickness.
20. Equilibrium and non-equilibrium properties of finite-volume crystallites
Degawa, Masashi
Finite volume effects on equilibrium and non-equilibrium properties of nano-crystallites are studied theoretically and compared to both experiment and simulation. When a system is isolated or its size is small compared to the correlation length, all equilibrium and close-to-equilibrium properties will depend on the system boundary condition. Specifically for solid nano-crystallites, their finite size introduces global curvature to the system, which alters its equilibrium properties compared to the thermodynamic limit. Also such global curvature leads to capillary-induced morphology changes of the surface. Interesting dynamics can arise when the crystallite is supported on a substrate, with crossovers of the dominant driving force from the capillary force and crystallite-substrate interactions. To address these questions, we introduce thermodynamic functions for the boundary conditions, which can be derived from microscopic models. For nano-crystallites, the boundary is the surface (including interfaces), the thermodynamic description is based on the steps that define the shape of the surface, and the underlying microscopic model includes kinks. The global curvature of the surface introduces metastable states with different shapes governed by a constant of integration of the extra boundary condition, which we call the shape parameter c. The discrete height of the steps introduces transition states in between the metastable states, and the lowest energy accessible structure (energy barrier less 10k BT) as a function of the volume has been determined. The dynamics of nano-crystallites as they relax from a non-equilibrium structure is described quantitatively in terms of the motion of steps in both capillary-induced and interface-boundary-induced regimes. The step-edge fluctuations of the top facet are also influenced by global curvature and volume conservation and the effect yields different dynamic scaling exponents from a pure 1D system. Theoretical results are
1. Electron properties and air mixing in radio frequency driven argon plasma jets at atmospheric pressure
SciTech Connect
Gessel, Bram van; Bruggeman, Peter; Brandenburg, Ronny
2013-08-05
A time modulated radio frequency (RF) plasma jet operated with an Ar mixture is investigated by measuring the electron density and electron temperature using Thomson scattering. The measurements have been performed spatially resolved for two different electrode configurations and as a function of the plasma dissipated power and air concentration admixed to the Ar. Time resolved measurements of electron densities and temperatures during the RF cycle and after plasma power switch-off are presented. Furthermore, the influence of the plasma on the air entrainment into the effluent is studied using Raman scattering.
2. Two-dimensional plasma grating by non-collinear femtosecond filament interaction in air
SciTech Connect
Liu Jia; Li Wenxue; Pan Haifeng; Zeng Heping
2011-10-10
We experimentally demonstrated that two-dimensional (2D) plasma gratings could be generated in air by nonlinear interaction of three femtosecond filaments. The intensity interference of non-collinearly overlapped filaments was self-projected along a relatively long distance and accompanied with a wavelength-scale periodic change of the refractive index in the encircling air due to periodic plasma density modulation. The 2D plasma gratings supported 2D diffraction of the generated third-harmonic pulses. By using in-line time-resolved holographic imaging and time-delayed diffraction, the 2D plasma gratings were evidenced to last a few tens picoseconds after the excitation pulses.
3. Plasma-catalyst coupling for volatile organic compound removal and indoor air treatment: a review
Thevenet, F.; Sivachandiran, L.; Guaitella, O.; Barakat, C.; Rousseau, A.
2014-06-01
The first part of the review summarizes the problem of air pollution and related air-cleaning technologies. Volatile organic compounds in particular have various effects on health and their abatement is a key issue. Different ways to couple non-thermal plasmas with catalytic or adsorbing materials are listed. In particular, a comparison between in-plasma and post-plasma coupling is made. Studies dealing with plasma-induced heterogeneous reactivity are analysed, as well as the possible modifications of the catalyst surface under plasma exposure. As an alternative to the conventional and widely studied plasma-catalyst coupling, a sequential approach has been recently proposed whereby pollutants are first adsorbed onto the material, then oxidized by switching on the plasma. Such a sequential approach is reviewed in detail.
4. Non-equilibrium thermodynamics and collective vibrational modes of liquid water in an inhomogeneous electric field.
PubMed
Wexler, Adam D; Drusová, Sandra; Woisetschläger, Jakob; Fuchs, Elmar C
2016-06-28
In this experiment liquid water is subject to an inhomogeneous electric field (∇(2)Ea≈ 10(10) V m(2)) using a high voltage (20 kV) point-plane electrode system. Using interferometry it was found that the application of a strong electric field gradient to water generates local changes in the refractive index of the liquid, polarizes the surface and creates a downward moving electro-convective jet. A maximum temperature difference of 1 °C is measured in the immediate vicinity of the point electrode. Raman spectroscopy performed on water reveals an enhancement of the vibrational collective modes (3250 cm(-1)) as well as an increase in the local mode (3490 cm(-1)) energy. This bimodal enhancement indicates that the spectral changes are not due to temperature changes. The intense field gradient thus establishes an excited subpopulation of vibrational oscillators far from thermal equilibrium. Delocalization of the collective vibrational mode spatially expands this excited population beyond the microscale. Hindered rotational freedom due to electric field pinning of molecular dipoles retards the heat flow and generates a chemical potential gradient. These changes are responsible for the observed changes in the refractive index and temperature. It is demonstrated that polar liquids can thus support local non-equilibrium thermodynamic transient states critical to biochemical and environmental processes. PMID:27253197
5. Shear viscosity of polar liquid mixtures via non-equilibrium molecular dynamics: water, methanol, and acetone
Wheeler Richard, Dean R.; Rowley, L.
Non-equilibrium molecular dynamics (NEMD) with isobaric and isokinetic controls were used to simulate the shear viscosity for binary mixtures of water, methanol and acetone, and for ternary mixtures. In all, 22 different liquid composition points were simulated at 298.15 K and 0.1 MPa. A new set of acetone potential parameters was developed, while slight variants to existing water and methanol models were used. Long range Coulombic interactions were computed with the Ewald sum adapted to Lees-Edwards boundary conditions as formulated in Wheeler, D. R., Fuller, N. G., and Rowley, R. L., 1997, Molec. Phys., 92, 55. The attractive (dispersive) part of the Lennard-Jones (LJ) interactions also was handled by a lattice sum. A hybrid mixing rule was used for the LJ cross interactions. Viscosities extrapolated to zero shear compared well with experimental results, having a mean absolute error of 14% and no errors greater than 30%. Although the simulations successfully predicted viscosity maxima for mixtures high in water content, the peak heights tended to be too low, probably due to the limitations of the water model. The results suggest that NEMD may be a viable means of estimating viscosities for polar liquid mixtures with an unrestricted number of components.
6. Numerical solution of 2D wet steam flow with non-equilibrium condensation and real thermodynamics
SciTech Connect
Hric, V.; Halama, J.
2015-03-10
An approach to modeling of wet steam flow with non-equilibrium condensation phenomenon is presented. The first part of our flow model is homogeneous Euler system of transport equations for mass, momentum and total energy of wet steam (mixture). The additional second part describes liquid phase via non-homogeneous system of transport equations for moments of droplets number distribution function and relies on corrected classical nucleation theory. Moment equations are closed by linearization of droplet growth rate model. All necessary relations for thermodynamic properties of steam are provided by IAPWS set of equations. However, properties of condensate are simply modeled by liquid saturation data. Two real equations of state are implemented. Recently developed CFD formulation for entropy (does not require iteration process) and so-called IAPWS special gas equation for Helmholtz energy (one iteration loop is necessary). Flow model is validated on converging-diverging supersonic nozzle with Barschdorff geometry. Simulations were performed by in-house CFD code based on finite volume method and stiff character of equations was solved by symmetrical time operator splitting. Achieved results satisfactorily agreed with experimental data.
7. Non-equilibrium molecular dynamics simulation of the unstirred layer in the osmotically driven flow
Konno, Keito; Itano, Tomoaki; Seki, Masako
2015-11-01
We studied the solvent flows driven by the osmotic pressure difference across the semi-permeable membrane. The flow penetrating from the low concentration side transports away solutes adjacent of the membrane, so that the concentration is reduced significantly only at the vicinity of the membrane. It is expected that the relatively low solute concentration develops into a thin boundary layer in the vicinity of the membrane in the case of absence of external stirring process, which is termed as un-stirred layer (USL). To investigate concentration distribution in USL, we carried out non-equilibrium molecular dynamics simulations. The flows driven by th osmotic pressure are idealized as 2 dimensional hard disk model, which is composed of solvent and solute molecules. The membrane is modeled as a medium composed of stationary parallel rods distributed by a spatial interval, which is less than the diameter of the solute molecules. The following results were obtained from the numerical simulation. First, the thickness of USL, which was estimated from the obtained concentration distribution, is on the order of a length determined by mean free path. Second, USL was semicircle the center of which is on the end of pore of membrane.
8. Influence of boundary slip effect on thermal environment in thermo-chemical non-equilibrium flow
Miao, Wenbo; Zhang, Liang; Li, Junhong; Cheng, Xiaoli
2014-12-01
A kind of new hypersonic vehicle makes long-time flight in transitional flow regime where boundary slip effect caused by low gas density will have an important influence on the thermal environment around the vehicles. Numerical studies on the boundary slip effect as hypersonic vehicles fly in high Mach number has been carried out. The method for solving non-equilibrium flows considering slip boundary, surface catalysis and chemical reactions has been built up, and been validated by comparing the thermal environment results with STS-2 flight test data. The mechanism and rules of impact on surface heat flux by different boundary slip level (Knudsen number from 0.01 to 0.05) has been investigated in typical hypersonic flow conditions. The results show that the influence mechanisms of boundary slip effect are different on component diffusion heat flux and convective heat flux; slip boundary increases the near wall temperature which diminish the convective heat; whereas enhances the near wall gas diffusion heat because of the internal energy's growing. Component diffusion heat flux takes a smaller portion of the total heat flux, so the slip boundary reduces the total wall heat flux. As Knudsen number goes up, the degree of rarefaction increases, the influences of slip boundary on convective and component diffusion heat flux are both enhanced, total heat flux grows by a small margin, and boundary slip effect is more distinct.
9. Relaxation of non-equilibrium entanglement networks in thin polymer films.
PubMed
McGraw, Joshua D; Fowler, Paul D; Ferrari, Melissa L; Dalnoki-Veress, Kari
2013-01-01
It is known that polymer films, prepared by spin coating, inherit non-equilibrium configurations which can affect macroscopic film properties. Here we present the results of crazing experiments that support this claim; our measurements indicate that the as-cast chain configurations are strongly stretched as compared to equilibrium Gaussian configurations. The results of our experiments also demonstrate that the entanglement network equilibrates on a time scale comparable to one reptation time. Having established that films can be prepared with an equilibrium entanglement network, we proceed by confining polymers to films in which the thickness is comparable to the molecular size. By stacking two such films, a bilayer is created with a buried entropic interface. Such an interface has no enthalpic cost, only an entropic penalty associated with the restricted configurations of molecules that cannot cross the mid-plane of the bilayer. In the melt, the entropic interface heals as chains from the two layers mix and entangle with one another; crazing measurements allow us to probe the dynamics of two films becoming one. Healing of the entropic interface is found to take less than one bulk reptation time.
10. A process-based model for non-equilibrium clumped isotope effects in carbonates
Watkins, J. M.; Hunt, J. D.
2015-12-01
The equilibrium clumped isotope composition of carbonate minerals is independent of the composition of the aqueous solution. However, many carbonate minerals grow at rates that place them in a non-equilibrium regime with respect to carbon and oxygen isotopes with unknown consequences for clumped isotopes. We develop a process-based model that allows one to calculate the oxygen, carbon, and clumped isotope composition of calcite as a function of temperature, crystal growth rate, and solution pH. In the model, carbon and oxygen isotope fractionation occurs through the mass-dependent attachment/detachment kinetics of the isotopologues of HCO-3 and CO2-3 to and from the calcite surface, which in turn, influence the clumped isotope composition of calcite. At experimental and biogenic growth rates, the mineral is expected to inherit a clumped isotopic composition that is similar to that of the DIC pool, which helps to explain (1) why different organisms share the same clumped isotope versus temperature calibration curves, (2) why many inorganic calibration curves are slightly different from one another, and (3) why foraminifera, coccoliths, and deep sea corals can have near-equilibrium clumped isotope compositions but far-from-equilibrium carbon and oxygen isotope compositions. Some aspects of the model can be generalized to other mineral systems and should serve as a useful reference in future efforts to quantify kinetic clumped isotope effects.
11. Fundamental limits of MWIR HgCdTe barrier detectors operating under non-equilibrium mode
Kopytko, M.; Jóźwikowski, K.; Rogalski, A.
2014-10-01
The paper presents numerical considerations of temperature-dependent performance of different mid-wave infrared HgCdTe detectors (with p- and n-type active layer) for non-equilibrium operation. Current-voltage characteristics of double heterostructure PpN photodiode, pBppN barrier photodiode, nBnn and nBnnN barrier detectors are compared to find an optimal architecture for high-operating temperature conditions. Using our model, the calculated characteristics of the devices are fitted to the experimental results for HgCdTe photodiode grown on GaAs substrate by metal organic chemical vapour deposition. The performance of photodiodes with p-type absorber are limited by the generation current associated with the Shockley-Read-Hall process, while nBnn type devices (with the n-type absorber) indicate a diffusion limited dark currents associated with Auger processes. At high values of the reverse bias (over 1 V), the trap states located at dislocations lead to strong band-to-band and trap-assisted tunnelling due to high electric field within the depletion layer.
12. Non-equilibrium Statistical Mechanics and the Sea Ice Thickness Distribution
We use concepts from non-equilibrium statistical physics to transform the original evolution equation for the sea ice thickness distribution g (h) due to Thorndike et al., (1975) into a Fokker-Planck like conservation law. The steady solution is g (h) = calN (q) hqe - h / H , where q and H are expressible in terms of moments over the transition probabilities between thickness categories. The solution exhibits the functional form used in observational fits and shows that for h << 1 , g (h) is controlled by both thermodynamics and mechanics, whereas for h >> 1 only mechanics controls g (h) . Finally, we derive the underlying Langevin equation governing the dynamics of the ice thickness h, from which we predict the observed g (h) . This allows us to demonstrate that the ice thickness field is ergodic. The genericity of our approach provides a framework for studying the geophysical scale structure of the ice pack using methods of broad relevance in statistical mechanics. Swedish Research Council Grant No. 638-2013-9243, NASA Grant NNH13ZDA001N-CRYO and the National Science Foundation and the Office of Naval Research under OCE-1332750 for support.
13. Optimization of an oligonucleotide microchip for microbial identification studies: a non-equilibrium dissociation approach
NASA Technical Reports Server (NTRS)
Liu, W. T.; Mirzabekov, A. D.; Stahl, D. A.
2001-01-01
The utility of a high-density oligonucleotide microarray (microchip) for identifying strains of five closely related bacilli (Bacillus anthracis, Bacillus cereus, Bacillus mycoides, Bacillus medusa and Bacillus subtilis) was demonstrated using an approach that compares the non-equilibrium dissociation rates ('melting curves') of all probe-target duplexes simultaneously. For this study, a hierarchical set of 30 oligonucleotide probes targeting the 16S ribosomal RNA of these bacilli at multiple levels of specificity (approximate taxonomic ranks of domain, kingdom, order, genus and species) was designed and immobilized in a high-density matrix of gel pads on a glass slide. Reproducible melting curves for probes with different levels of specificity were obtained using an optimized salt concentration. Clear discrimination between perfect match (PM) and mismatch (MM) duplexes was achieved. By normalizing the signals to an internal standard (a universal probe), a more than twofold discrimination (> 2.4x) was achieved between PM and 1-MM duplexes at the dissociation temperature at which 50% of the probe-target duplexes remained intact. This provided excellent differentiation among representatives of different Bacillus species, both individually and in mixtures of two or three. The overall pattern of hybridization derived from this hierarchical probe set also provided a clear 'chip fingerprint' for each of these closely related Bacillus species.
14. Spin-population inversion in magnetic point contacts under non-equilibrium conditions
Pietsch, Torsten; Egle, Stefan; Scheer, Elke
2012-02-01
The creation of a novel type of spin-based electronics is one of the most intensively researched topics in current solid-state physics. The unifying characteristics in this advancing field is that the spin degree of freedom of the electron rather than its charge is exploited to achieve a specific device functionality. Recently, theoretical predictions suggest that spin-inversion in metallic point contacts under strong non-equilibrium conditions may enable the design of novel types of radiation sources. These radiation sources are highly tunable and of giant intensity compared to cutting-edge semiconductor devices, due to the much larger electron density in metals. Moreover, the accessible frequency range covers both, microwave (GHz) and THz radiation. Especially the later one is of great interest, since up to date there is no miniaturized, high intensity THz source available. Therefore, the experimental demonstration of this lasing effect in metallic systems is an important breakthrough in solid state physics. Presently the concept of spin-flip lasing in magnetic point contacts rests on theoretical predictions and first proof of principle studies. Herein we present detailed investigations on the magneto-transport properties of magnetic herterostructures and -point contacts. In particular, we study the complex interplay between magnetization, current density and the influence of high frequency (GHz and THz) fields on the magneto-transport properties of magnetic point contacts. The results illustrate that a successful spin-population inversion can be detected via transport spectroscopy.
15. Visualizing non-equilibrium lithiation of spinel oxide via in situ transmission electron microscopy.
PubMed
He, Kai; Zhang, Sen; Li, Jing; Yu, Xiqian; Meng, Qingping; Zhu, Yizhou; Hu, Enyuan; Sun, Ke; Yun, Hongseok; Yang, Xiao-Qing; Zhu, Yimei; Gan, Hong; Mo, Yifei; Stach, Eric A; Murray, Christopher B; Su, Dong
2016-01-01
Spinel transition metal oxides are important electrode materials for lithium-ion batteries, whose lithiation undergoes a two-step reaction, whereby intercalation and conversion occur in a sequential manner. These two reactions are known to have distinct reaction dynamics, but it is unclear how their kinetics affects the overall electrochemical response. Here we explore the lithiation of nanosized magnetite by employing a strain-sensitive, bright-field scanning transmission electron microscopy approach. This method allows direct, real-time, high-resolution visualization of how lithiation proceeds along specific reaction pathways. We find that the initial intercalation process follows a two-phase reaction sequence, whereas further lithiation leads to the coexistence of three distinct phases within single nanoparticles, which has not been previously reported to the best of our knowledge. We use phase-field theory to model and describe these non-equilibrium reaction pathways, and to directly correlate the observed phase evolution with the battery's discharge performance. PMID:27157119
16. Equilibrium and non-equilibrium thermodynamics of templating reactions for the formation of nanowires
Watson, Scott M. D.; Houlton, Andrew; Horrocks, Benjamin R.
2012-12-01
The thermodynamics of the templating of materials on one-dimensional templates, such as DNA, is modeled by considering two terms: the surface tension of the material (γ) and a line energy (σ = 2πrTγT) that represents the adhesion of the material to the template (radius rT). We show that as long as the reaction stoichiometry does not exceed a certain limit (\\sqrt{\\frac{3 v}{2 \\pi }}\\lt {r}_{T}\\frac{\\vert {\\gamma }_{T}\\vert }{\\gamma }; v = volume of material per unit length of template) then a sample of smooth, uniform wires is the equilibrium state. If the amount of material exceeds this limit, then the material will comprise a single macroscopic particle at equilibrium. The behavior of the system is similar to a morphological wetting transition and the model can rationalize the available experimental data on the reaction conditions required to form smooth DNA-templated nanowires. Using the framework of linear non-equilibrium thermodynamics, we also show that the model can describe qualitatively the observed evolution of these nanostructures from beads-on-a-string morphologies to smooth nanowires and construct a stochastic differential equation for the process. Numerical simulations and scaling arguments suggest that the same scaling behavior as the Edwards-Wilkinson equation is observed.
17. Collective non-equilibrium spin exchange in cold alkaline-earth atomic clocks
Acevedo, Oscar Leonardo; Rey, Ana Maria
2016-05-01
Alkaline-earth atomic (AEA) clocks have recently been shown to be reliable simulators of two-orbital SU(N) quantum magnetism. In this work, we study the non-equilibrium spin exchange dynamics during the clock interrogation of AEAs confined in a deep one-dimensional optical lattice and prepared in two nuclear levels. The two clock states act as an orbital degree of freedom. Every site in the lattice can be thought as populated by a frozen set of vibrational modes collectively interacting via predominantly p-wave collisions. Due to the exchange coupling, orbital state transfer between atoms with different nuclear states is expected to happen. At the mean field level, we observe that in addition to the expected suppression of population transfer in the presence of a large magnetic field, that makes the single particle levels off-resonance, there is also an interaction induced suppression for initial orbital population imbalance. This suppression resembles the macroscopic self-trapping mechanism seen in bosonic systems. However, by performing exact numerical solutions and also by using the so-called Truncated Wigner Approximation, we show that quantum correlations can significantly modify the mean field suppression. Our predictions should be testable in optical clock experiments. Project supported by NSF-PHY-1521080, JILA-NSF-PFC-1125844, ARO, AFOSR, and MURI-AFOSR.
18. Non-equilibrium model of two-phase porous media flow with phase change
Cueto-Felgueroso, L.; Fu, X.; Juanes, R.
2014-12-01
The efficient simulation of multi-phase multi-component flow through geologic porous media is challenging and computationally intensive, yet quantitative modeling of these processes is essential in engineering and the geosciences. Multiphase flow with phase change and complex phase behavior arises in numerous applications, including enhanced oil recovery, steam injection in groundwater remediation, geologic CO2 storage and enhanced geothermal energy systems. A challenge of multiphase compositional simulation is that the number of existing phases varies with position and time, and thus the number of state variables in the saturation-based conservation laws is a function of space and time. The tasks of phase-state identification and determination of the composition of the different phases are performed assuming local thermodynamic equilibrium. Here we investigate a thermodynamically consistent formulation for non-isothermal two-phase flow, in systems where the hypothesis of instantaneous local equilibrium does not hold. Non-equilibrium effects are important in coarse-scale simulations where the assumption of complete mixing in each gridblock is not realistic. We apply our model to steam injection in water-saturated porous media.
19. Non-equilibrium relaxation in a two-dimensional stochastic lattice Lotka-Volterra model
Chen, Sheng; Täuber, Uwe C.
We employ Monte Carlo simulations to study a stochastic Lotka-Volterra model on a two-dimensional square lattice with periodic boundary conditions. There are stable states when the predators and prey coexist. If the local prey carrying capacity is finite, there emerges an extinction threshold for the predator population at a critical value of the predation rate. We investigate the non-equilibrium relaxation of the predator density in the vicinity of this critical point. The expected power law dependence between the relaxation time and predation rate is observed (critical slowing down). The numerically determined associated critical exponents are in accord with the directed percolation universality class. Following a sudden predation rate change to its critical value, one observes critical aging for the predator density autocorrelation function with a universal scaling exponent. This aging scaling signature of the absorbing state phase transition emerges at significantly earlier times than stationary critical power laws, and could thus serve as an advanced indicator of the population's proximity to its extinction threshold. This research is supported by the U. S. Department of Energy, Office of Basic Energy Sciences, Division of Materials Science and Engineering under Award DE-FG02-09ER46613.
20. Non-equilibrium relaxation in a stochastic lattice Lotka-Volterra model.
PubMed
Chen, Sheng; Täuber, Uwe C
2016-04-19
We employ Monte Carlo simulations to study a stochastic Lotka-Volterra model on a two-dimensional square lattice with periodic boundary conditions. If the (local) prey carrying capacity is finite, there exists an extinction threshold for the predator population that separates a stable active two-species coexistence phase from an inactive state wherein only prey survive. Holding all other rates fixed, we investigate the non-equilibrium relaxation of the predator density in the vicinity of the critical predation rate. As expected, we observe critical slowing-down, i.e., a power law dependence of the relaxation time on the predation rate, and algebraic decay of the predator density at the extinction critical point. The numerically determined critical exponents are in accord with the established values of the directed percolation universality class. Following a sudden predation rate change to its critical value, one finds critical aging for the predator density autocorrelation function that is also governed by universal scaling exponents. This aging scaling signature of the active-to-absorbing state phase transition emerges at significantly earlier times than the stationary critical power laws, and could thus serve as an advanced indicator of the (predator) population's proximity to its extinction threshold.
1. Non-equilibrium relaxation in a stochastic lattice Lotka-Volterra model
Chen, Sheng; Täuber, Uwe C.
2016-04-01
We employ Monte Carlo simulations to study a stochastic Lotka-Volterra model on a two-dimensional square lattice with periodic boundary conditions. If the (local) prey carrying capacity is finite, there exists an extinction threshold for the predator population that separates a stable active two-species coexistence phase from an inactive state wherein only prey survive. Holding all other rates fixed, we investigate the non-equilibrium relaxation of the predator density in the vicinity of the critical predation rate. As expected, we observe critical slowing-down, i.e., a power law dependence of the relaxation time on the predation rate, and algebraic decay of the predator density at the extinction critical point. The numerically determined critical exponents are in accord with the established values of the directed percolation universality class. Following a sudden predation rate change to its critical value, one finds critical aging for the predator density autocorrelation function that is also governed by universal scaling exponents. This aging scaling signature of the active-to-absorbing state phase transition emerges at significantly earlier times than the stationary critical power laws, and could thus serve as an advanced indicator of the (predator) population’s proximity to its extinction threshold.
2. Experimental realization of atomtronic circuit elements in non-equilibrium ultracold atomic systems
Caliga, Seth C.
Research in the field of atomtronics aims to develop a new paradigm for the use of ultracold atomic systems in a manner that mimics the functionality of electronic circuits and devices. Given the ubiquity of the electronic transistor and its application to a vast array of signal processing tasks, the development of its atomtronic counterpart is of significant interest. This dissertation presents the experimental studies of two atomtronic circuit elements: a battery and transistor. Experiments are conducted in an atom-chip-based apparatus utilizing hybrid magnetic and optical trapping techniques that enable one to pattern" atomtronic circuit elements. An atomtronic battery is realized in a double-well trapping potential in which a finite-temperature Bose-Einstein condensate is prepared in a non-equilibrium state to generate thermodynamic gradients that drive atom current flow. Powered by the atomtronic battery, a triple-well atomtronic transistor is demonstrated, and quasi-steady-state behavior of the device is characterized. Results are found to be in agreement with a semiclassical model of the transistor that is also used to study the active properties of the device, including current gain. Based on these results, future directions regarding signal processing operations are proposed.
3. An improved dynamic non-equilibrium wall-model for large eddy simulation
Park, George Ilhwan; Moin, Parviz
2013-11-01
A non-equilibrium wall-model based on unsteady 3D Reynolds-averaged Navier-Stokes (RANS) equations has been implemented in an unstructured mesh environment. The method is similar to that of the wall-model described by Wang and Moin [Phys. Fluids 14, 2043-2051, (2002)], but is supplemented by a new dynamic eddy viscosity/conductivity model that corrects the effect of the resolved Reynolds stress (resolved turbulent heat flux) on the skin friction (wall heat flux). This correction is crucial for accurate prediction of the skin friction and wall heat flux. Unlike earlier models, this eddy viscosity/conductivity model does not have a stress-matching procedure or a tunable free parameter, and it shows consistent performance over a wide range of Reynolds numbers. The wall-model is validated against canonical (attached) transitional and fully turbulent flows at moderate to very high Reynolds number: a turbulent channel flow at Reτ = 2000, an H-type transitional boundary layer up to Reθ = 3300, and a high Reynolds number boundary layer at Reθ = 31000. An application to the flow over NACA4412 airfoil is ongoing and hopefully will be presented. This work was supported by the Winston and Fu-Mei Stanford Graduate Fellowship, NASA Aeronautics Scholarship Program, and NASA under the Subsonic Fixed-Wing Program and the Boeing Company.
4. Non-equilibrium Stokes-Einstein relation via active microrheology of hydrodynamically interacting suspensions
Chu, Henry; Zia, Roseanna
In our recently developed non-equilibrium Stokes-Einstein relation, we showed that, in the absence of hydrodynamic interactions, the stress in a suspension is given by a balance between fluctuation and dissipation. Here, we generalize our theory for systems of hydrodynamically interacting colloids, via active microrheology, where motion of a Brownian probe through the medium reveals rheological properties. The strength of probe forcing compared to the entropic restoring force defines a Peclet number, Pe. In the absence of hydrodynamics, the first normal stress difference and the osmotic pressure scale as Pe4 and Pe2 respectively when probe forcing is weak, and uniformly as Pe for strong probe forcing. As hydrodynamics become important, interparticle forces give way to lubrication interactions. Hydrodynamic coupling leads to a new low-Pe scaling of the first normal stress difference and the osmotic pressure as Pe2, and high-Pe scaling as Peδ, where 0.799 <= δ <= 1 as hydrodynamics vary from strong to weak. For the entire range of the strength of hydrodynamic interactions and probe forcing, the new phenomenological theory is shown to agree with standard micromechanical definitions of the stress. We further draw a connection between the stress and the energy storage in a suspension, and the entropic nature of such storage is identified.
5. Non-equilibrium relaxation in a stochastic lattice Lotka–Volterra model
Chen, Sheng; Täuber, Uwe C.
2016-04-01
We employ Monte Carlo simulations to study a stochastic Lotka–Volterra model on a two-dimensional square lattice with periodic boundary conditions. If the (local) prey carrying capacity is finite, there exists an extinction threshold for the predator population that separates a stable active two-species coexistence phase from an inactive state wherein only prey survive. Holding all other rates fixed, we investigate the non-equilibrium relaxation of the predator density in the vicinity of the critical predation rate. As expected, we observe critical slowing-down, i.e., a power law dependence of the relaxation time on the predation rate, and algebraic decay of the predator density at the extinction critical point. The numerically determined critical exponents are in accord with the established values of the directed percolation universality class. Following a sudden predation rate change to its critical value, one finds critical aging for the predator density autocorrelation function that is also governed by universal scaling exponents. This aging scaling signature of the active-to-absorbing state phase transition emerges at significantly earlier times than the stationary critical power laws, and could thus serve as an advanced indicator of the (predator) population’s proximity to its extinction threshold.
SciTech Connect
B. Philip; Z. Wang; M.A. Berrill; M. Birke; M. Pernice
2014-04-01
The time dependent non-equilibrium radiation diffusion equations are important for solving the transport of energy through radiation in optically thick regimes and find applications in several fields including astrophysics and inertial confinement fusion. The associated initial boundary value problems that are encountered often exhibit a wide range of scales in space and time and are extremely challenging to solve. To efficiently and accurately simulate these systems we describe our research on combining techniques that will also find use more broadly for long term time integration of nonlinear multi-physics systems: implicit time integration for efficient long term time integration of stiff multi-physics systems, local control theory based step size control to minimize the required global number of time steps while controlling accuracy, dynamic 3D adaptive mesh refinement (AMR) to minimize memory and computational costs, Jacobian Free Newton–Krylov methods on AMR grids for efficient nonlinear solution, and optimal multilevel preconditioner components that provide level independent solver convergence.
7. The lagRST Model: A Turbulence Model for Non-Equilibrium Flows
NASA Technical Reports Server (NTRS)
Lillard, Randolph P.; Oliver, A. Brandon; Olsen, Michael E.; Blaisdell, Gregory A.; Lyrintzis, Anastasios S.
2011-01-01
This study presents a new class of turbulence model designed for wall bounded, high Reynolds number flows with separation. The model addresses deficiencies seen in the modeling of nonequilibrium turbulent flows. These flows generally have variable adverse pressure gradients which cause the turbulent quantities to react at a finite rate to changes in the mean flow quantities. This "lag" in the response of the turbulent quantities can t be modeled by most standard turbulence models, which are designed to model equilibrium turbulent boundary layers. The model presented uses a standard 2-equation model as the baseline for turbulent equilibrium calculations, but adds transport equations to account directly for non-equilibrium effects in the Reynolds Stress Tensor (RST) that are seen in large pressure gradients involving shock waves and separation. Comparisons are made to several standard turbulence modeling validation cases, including an incompressible boundary layer (both neutral and adverse pressure gradients), an incompressible mixing layer and a transonic bump flow. In addition, a hypersonic Shock Wave Turbulent Boundary Layer Interaction with separation is assessed along with a transonic capsule flow. Results show a substantial improvement over the baseline models for transonic separated flows. The results are mixed for the SWTBLI flows assessed. Separation predictions are not as good as the baseline models, but the over prediction of the peak heat flux downstream of the reattachment shock that plagues many models is reduced.
8. A steady-state non-equilibrium molecular dynamics approach for the study of evaporation processes.
PubMed
Zhang, Jianguo; Müller-Plathe, Florian; Yahia-Ouahmed, Méziane; Leroy, Frédéric
2013-10-01
Two non-equilibrium methods (called bubble method and splitting method, respectively) have been developed and tested to study the steady state evaporation of a droplet surrounded by its vapor, where the evaporation continuously occurs at the vapor-liquid interface while the droplet size remains constant. In the bubble method, gas molecules are continuously reinserted into a free volume (represented by a bubble) located at the centre of mass of the droplet to keep the droplet size constant. In the splitting method, a molecule close to the centre of mass of the droplet is split into two: In this way, the droplet size is also maintained during the evaporation. By additional local thermostats confined to the area of insertion, the effect of frequent insertions on properties such as density and temperature can be limited to the immediate insertion area. Perturbations are not observed in other parts of the droplet. In the end, both the bubble method and the splitting method achieve steady-state droplet evaporation. Although these methods have been developed using an isolated droplet, we anticipate that they will find a wide range of applications in the study of the evaporation of isolated films and droplets or thin films on heated substrates or under confinement. They can in principle also be used to study the steady-state of other physical processes, such as the diffusion or permeation of gas molecules or ions in a pressure gradient or a concentration gradient. PMID:24116576
9. Non-equilibrium steady-state distributions of colloids in a tilted periodic potential
Ma, Xiaoguang; Lai, Pik-Yin; Ackerson, Bruce; Tong, Penger
A two-layer colloidal system is constructed to study the effects of the external force F on the non-equilibrium steady-state (NESS) dynamics of the diffusing particles over a tilted periodic potential, in which detailed balance is broken due to the presence of a steady particle flux. The periodic potential is provided by the bottom layer colloidal spheres forming a fixed crystalline pattern on a glass substrate. The corrugated surface of the bottom colloidal crystal provides a gravitational potential field for the top layer diffusing particles. By tilting the sample with respect to gravity, a tangential component F is applied to the diffusing particles. The measured NESS probability density function Pss (x , y) of the particles is found to deviate from the equilibrium distribution depending on the driving or distance from equilibrium. The experimental results are compared with the exact solution of the 1D Smoluchowski equation and the numerical results of the 2D Smoluchowski equation. Moreover, from the obtained exact 1D solution, we develop an analytical method to accurately extract the 1D potential U0 (x) from the measured Pss (x) . Work supported in part by the Research Grants Council of Hong Kong SAR.
10. A PDE Formulation of Non-Equilibrium Statistical Mechanics for Ionic Permeation
Schuss, Zeev; Nadler, Boaz; Singer, Amit; Eisenberg, Robert S.
2003-05-01
When there is a steady net flux in a system of interacting particles, the microscopic structure of the system can no longer be determined from the Boltzmann equilibrium distribution (partition function). Nonetheless, the microscopic structure of a finite system of diffusing interacting particles can be described by Poisson-Nernst-Planck-type partial differential equations. These equations, defined in a finite domain, are the non-equilibrium generalization of the BBGKY hierarchy of equilibrium statistical mechanics. Indeed, when no-flux conditions are imposed on the domain boundaries, equilibrium results are recovered. When non-homogeneous boundary conditions are given for these equations, the solutions describe densities and electrostatic potentials of particle systems not in equilibrium. The construction of a pair correlation function under these conditions will be a new result in statistical physics. As in the equilibrium case, a closure relation between a higher and a lower order correlation function has to be assumed. However, since we are considering a finite system, boundary conditions for the higher order correlation functions must also be derived. In applications to the permeation of ions through protein channels of biological membranes the computation of the pair correlation function will lead to a prediction of current through an open channel, given the spatial structure and fixed charge distribution. The pair correlation function contains finite size effects that lead to blocking in a narrow channel and possibly to selectivity.
11. Visualizing non-equilibrium lithiation of spinel oxide via in situ transmission electron microscopy
PubMed Central
He, Kai; Zhang, Sen; Li, Jing; Yu, Xiqian; Meng, Qingping; Zhu, Yizhou; Hu, Enyuan; Sun, Ke; Yun, Hongseok; Yang, Xiao-Qing; Zhu, Yimei; Gan, Hong; Mo, Yifei; Stach, Eric A.; Murray, Christopher B.; Su, Dong
2016-01-01
Spinel transition metal oxides are important electrode materials for lithium-ion batteries, whose lithiation undergoes a two-step reaction, whereby intercalation and conversion occur in a sequential manner. These two reactions are known to have distinct reaction dynamics, but it is unclear how their kinetics affects the overall electrochemical response. Here we explore the lithiation of nanosized magnetite by employing a strain-sensitive, bright-field scanning transmission electron microscopy approach. This method allows direct, real-time, high-resolution visualization of how lithiation proceeds along specific reaction pathways. We find that the initial intercalation process follows a two-phase reaction sequence, whereas further lithiation leads to the coexistence of three distinct phases within single nanoparticles, which has not been previously reported to the best of our knowledge. We use phase-field theory to model and describe these non-equilibrium reaction pathways, and to directly correlate the observed phase evolution with the battery's discharge performance. PMID:27157119
12. Exterior integrability: Yang-Baxter form of non-equilibrium steady-state density operator
Prosen, Tomaž; Ilievski, Enej; Popkov, Vladislav
2013-07-01
A new type of quantum transfer matrix, arising as a Cholesky factor for the steady-state density matrix of a dissipative Markovian process associated with the boundary-driven Lindblad equation for the isotropic spin-1/2 Heisenberg (XXX) chain, is presented. The transfer matrix forms a commuting family of non-Hermitian operators depending on the spectral parameter, which is essentially the strength of dissipative coupling at the boundaries. The intertwining of the corresponding Lax and monodromy matrices is performed by an infinitely dimensional Yang-Baxter R-matrix, which we construct explicitly and is essentially different from the standard 4 × 4 XXX R-matrix. We also discuss a possibility to construct Bethe ansatz for the spectrum and eigenstates of the non-equilibrium steady-state density operator. Furthermore, we indicate the existence of a deformed R-matrix in the infinite dimensional auxiliary space for the anisotropic XXZ spin-1/2 chain, which in general provides a sequence of new, possibly quasi-local, conserved quantities of the bulk XXZ dynamics.
13. Non-equilibrium dynamics around integrability in a one-dimensional two-component Bose gas
van Druten, Nicolaas; Wicke, Philipp; Whitlock, Shannon
2011-05-01
We investigate a one-dimensional two-component Bose gas near the point of state-independent interactions. At this specific point the system is integrable, in the sense that exact (thermodynamic) Bethe Ansatz solutions can be applied locally. In the experiments, we employ an atom chip and the magnetically trappable clock states in 87Rb. State-dependent potentials are generated by using the polarization dependence of radio-frequency dressing. We show that this allows us to continuously and dynamically tune both the local interactions and the global trapping potential. The experimentally accessible range in interactions includes the region around the integrability point. We study the spin motion that follows upon a sudden change in the system, a quantum quench. When starting from a low-temperature, quantum-degenerate gas in the weakly interacting regime, good agreement with a Gross-Pitaevskii description is found. The experiment allows exploring regimes that go beyond such a description and opens up a novel route to the study of the relation between non-equilibrium dynamics, thermalization and the making and breaking of integrability in quantum many-body physics. Supported by FOM, NWO and EU
14. A localized momentum constraint for non-equilibrium molecular dynamics simulations.
PubMed
Smith, E R; Heyes, D M; Dini, D; Zaki, T A
2015-02-21
A method which controls momentum evolution in a sub-region within a molecular dynamics simulation is derived from Gauss's principle of least constraint. The technique for localization is founded on the equations by Irving and Kirkwood [J. Chem. Phys. 18, 817 (1950)] expressed in a weak form according to the control volume (CV) procedure derived by Smith et al. [Phys. Rev. E. 85, 056705 (2012)]. A term for the advection of molecules appears in the derived constraint and is shown to be essential in order to exactly control the time evolution of momentum in the subvolume. The numerical procedure converges the total momentum in the CV to the target value to within machine precision in an iterative manner. The localized momentum constraint can prescribe essentially arbitrary flow fields in non-equilibrium molecular dynamics simulations. The methodology also forms a rigorous mathematical framework for introducing coupling constraints at the boundary between continuum and discrete systems. This functionality is demonstrated with a boundary-driven flow test case.
15. Non-equilibrium thermodynamics and collective vibrational modes of liquid water in an inhomogeneous electric field.
PubMed
Wexler, Adam D; Drusová, Sandra; Woisetschläger, Jakob; Fuchs, Elmar C
2016-06-28
In this experiment liquid water is subject to an inhomogeneous electric field (∇(2)Ea≈ 10(10) V m(2)) using a high voltage (20 kV) point-plane electrode system. Using interferometry it was found that the application of a strong electric field gradient to water generates local changes in the refractive index of the liquid, polarizes the surface and creates a downward moving electro-convective jet. A maximum temperature difference of 1 °C is measured in the immediate vicinity of the point electrode. Raman spectroscopy performed on water reveals an enhancement of the vibrational collective modes (3250 cm(-1)) as well as an increase in the local mode (3490 cm(-1)) energy. This bimodal enhancement indicates that the spectral changes are not due to temperature changes. The intense field gradient thus establishes an excited subpopulation of vibrational oscillators far from thermal equilibrium. Delocalization of the collective vibrational mode spatially expands this excited population beyond the microscale. Hindered rotational freedom due to electric field pinning of molecular dipoles retards the heat flow and generates a chemical potential gradient. These changes are responsible for the observed changes in the refractive index and temperature. It is demonstrated that polar liquids can thus support local non-equilibrium thermodynamic transient states critical to biochemical and environmental processes.
16. Radiation-induced non-equilibrium redox chemistry of plutonium: implications for environmental migration
SciTech Connect
Haschke, J M; Siekhaus, W J
2009-02-11
Static concentrations of plutonium oxidation states in solution and at surfaces in oxide-water systems are identified as non-equilibrium steady states. These kinetically controlled systems are described by redox cycles based on irreversible disproportionation of Pu(IV), Pu(V), and Pu(VI) in OH-bridged intermediate complexes and at OH-covered oxide surfaces. Steady state is fixed by continuous redox cycles driven by radioactivity-promoted electron-transfer and energetically favorable reactions of Pu(III) and Pu(VII) disproportionation products with H2O. A model based on the redox cycles accounts for the high steady-state [Pu] coexisting with Pu(IV) hydrous oxide at pH 0-15 and for predominance of Pu(V) and Pu(VI) in solution. The steady-state [Pu] depends on pH and the surface area of oxide in solution, but not on the initial Pu oxidation state. PuO{sub 2+x} formation is attributed to high Pu(V) concentrations existing at water-exposed oxide surfaces. Results infer that migration of Pu in an aqueous environment is controlled by kinetic factors unique to that site and that the predominant oxidation states in solution are Pu(V) and Pu(VI).
17. A microscopic, non-equilibrium, statistical field theory for cosmic structure formation
Bartelmann, Matthias; Fabis, Felix; Berg, Daniel; Kozlikin, Elena; Lilow, Robert; Viermann, Celia
2016-04-01
Building upon the recent pioneering work by Mazenko and by Das and Mazenko, we develop a microscopic, non-equilibrium, statistical field theory for initially correlated canonical ensembles of classical microscopic particles obeying Hamiltonian dynamics. Our primary target is cosmic structure formation, where initial Gaussian correlations in phase space are believed to be set by inflation. We give an exact expression for the generating functional of this theory and work out suitable approximations. We specify the initial correlations by a power spectrum and derive general expressions for the correlators of the density and the response field. We derive simple closed expressions for the lowest-order contributions to the nonlinear cosmological power spectrum, valid for arbitrary wave numbers. We further calculate the bispectrum expected in this theory within these approximations and the power spectrum of cosmic density fluctuations to first order in the gravitational interaction, using a recent improvement of the Zel’dovich approximation. We show that, with a modification motivated by the adhesion approximation, the nonlinear growth of the density power spectrum found in numerical simulations of cosmic structure evolution is reproduced well to redshift zero and for arbitrary wave numbers even within first-order perturbation theory. Our results present the first fully analytic calculation of the nonlinear power spectrum of cosmic structures.
18. Non-equilibrium dynamics of the complex Ginzburg-Landau equation
Liu, Weigang; Tauber, Uwe
The complex Ginzburg-Landau equation combines the quantum many-particle nonlinear Schrödinger equation with the time-dependent Ginzburg-Landau equation or model A relaxational dynamics. It arises in quite diverse contexts that include spontaneous pattern formation out of equilibrium, chemical oscillations, multi-mode lasers, thermal convection in binary fluids, cyclic population dynamics, and driven-dissipative Bose-Einstein condensates. Indeed, the complex Ginzburg-Landau equation exhibits a remarkably rich phase diagram with intriguing dynamics. We employ detailed numerical studies as well as analytical tools such as the perturbative renormalization group and the spherical model limit to study the non-equilibrium coarsening and critical aging scaling for the complex Ginzburg-Landau equation following quenches from an initial disordered configuration to either one of the ordered phases or the critical point. This research is supported by the U. S. Department of Energy, Office of Basic Energy Sciences, Division of Materials Science and Engineering under Award DE-FG02-09ER46613.
19. The effect of turbulent fluctuations on the relaxation of thermal non-equilibrium
Khurshid, Sualeh; Donzis, Diego
2015-11-01
In many engineering and natural systems, the microscopic behavior of constituent molecules can affect the macroscopic behavior of the flow. This interaction is significant when the two phenomena have commensurate time scales. We study the effect of turbulence on the relaxation of thermal non-equilibrium (TNE), in particular vibrational energy relaxation, using direct numerical simulation (DNS). First order effects are observed in the evolution of both vibrational energy and turbulence. For example, the rate of decay of kinetic energy is accelerated and temperature fluctuations are amplified. Analytic expressions for equilibrium vibrational energy, Ev*,and characteristic relaxation time scale, τv, are compared against DNS data and used to understand features of the decay. This decay can be divided into two regimes, one dominated by TNE exchanges in time scales of the order of τv followed by a turbulence decay. Between the two regimes, some vibrationally hot flows become cold before reaching equilibrium. This reflects an aspect of the strong coupling between turbulence and TNE in both regimes. Compressiblity effects, quantified by turbulent Mach number (Mt), are also discussed.
20. Non-equilibrium relaxation in a stochastic lattice Lotka-Volterra model.
PubMed
Chen, Sheng; Täuber, Uwe C
2016-04-01
We employ Monte Carlo simulations to study a stochastic Lotka-Volterra model on a two-dimensional square lattice with periodic boundary conditions. If the (local) prey carrying capacity is finite, there exists an extinction threshold for the predator population that separates a stable active two-species coexistence phase from an inactive state wherein only prey survive. Holding all other rates fixed, we investigate the non-equilibrium relaxation of the predator density in the vicinity of the critical predation rate. As expected, we observe critical slowing-down, i.e., a power law dependence of the relaxation time on the predation rate, and algebraic decay of the predator density at the extinction critical point. The numerically determined critical exponents are in accord with the established values of the directed percolation universality class. Following a sudden predation rate change to its critical value, one finds critical aging for the predator density autocorrelation function that is also governed by universal scaling exponents. This aging scaling signature of the active-to-absorbing state phase transition emerges at significantly earlier times than the stationary critical power laws, and could thus serve as an advanced indicator of the (predator) population's proximity to its extinction threshold. PMID:27092871
1. NON-EQUILIBRIUM CHEMISTRY OF DYNAMICALLY EVOLVING PRESTELLAR CORES. II. IONIZATION AND MAGNETIC FIELD
SciTech Connect
Tassis, Konstantinos; Willacy, Karen; Yorke, Harold W.; Turner, Neal J.
2012-07-20
We study the effect that non-equilibrium chemistry in dynamical models of collapsing molecular cloud cores has on measurements of the magnetic field in these cores, the degree of ionization, and the mean molecular weight of ions. We find that OH and CN, usually used in Zeeman observations of the line-of-sight magnetic field, have an abundance that decreases toward the center of the core much faster than the density increases. As a result, Zeeman observations tend to sample the outer layers of the core and consistently underestimate the core magnetic field. The degree of ionization follows a complicated dependence on the number density at central densities up to 10{sup 5} cm{sup -3} for magnetic models and 10{sup 6} cm{sup -3} in non-magnetic models. At higher central densities, the scaling approaches a power law with a slope of -0.6 and a normalization which depends on the cosmic-ray ionization rate {zeta} and the temperature T as ({zeta}T){sup 1/2}. The mean molecular weight of ions is systematically lower than the usually assumed value of 20-30, and, at high densities, approaches a value of 3 due to the asymptotic dominance of the H{sup +}{sub 3} ion. This significantly lower value implies that ambipolar diffusion operates faster.
2. The Ion-Specific, Non-Equilibrium Structural Behavior of DNA Hydrogels
Nguyen, Dan; Saleh, Omar
The highly tunable, sequence-dependent hybridization of DNA has enabled construction of DNA hydrogels with applications ranging from drug delivery to responsive materials. Though many have examined the structural characteristics of DNA hydrogels at equilibrium, relatively little is known about their non-equilibrium behavior, apart from their degradation rates when delivering molecular payloads. Here, we examine the effect of changing salt concentration on the dynamic formation, ageing, and degradation of DNA hydrogels comprised of branched DNA nanostars with palindromic overhangs. First, we observe that hydrogel phase is sensitive to the presence of a single unpaired base on the overhang, resulting in either a percolated network or a liquid-liquid phase separated state at high salt concentrations. Particular to the percolated network, we can induce the system to either contract or relax by changing the salt concentration. Decreasing monovalent NaCl induces the network to irreversibly contract whereas decreasing divalent MgCl2 induces the network to reversibly expand; this behavior runs counter to what is expected solely from electrostatic screening. We qualitatively understand these results by assuming that the monovalent salt modulates the dynamic hybridization between nanostar binding partners, whereas the divalent salt drives the dramatic/reversible induction of the stacked-X' conformation in the DNA nanostars. Biomolecular Science and Engineering Program.
3. Scale Invariance and Self-Similarity of 1-Dimensional Non-equilibrium Suspended Sediment Transport
Carr, K. J.; Ercan, A.; Kavvas, M. L.
2014-12-01
The conditions under which the governing equation for non-equilibrium one-dimensional suspended sediment transport in unsteady flows is scale-invariant and self-similar are examined by applying the one-parameter Lie group of point scaling transformations. Self-similarity conditions imposed due to initial and boundary conditions are also examined. Furthermore, one-parameter Lie group point scaling transformations required to physically scale the transport process without scaling the sediment material properties are identified and investigated. Preserving sediment density and diameter is believed to eliminate some of the scale errors encountered in traditional scaling methods. Under these conditions, not only are sediment diameter and density unscaled, but so too are the critical and total shear, kinematic viscosity and particle Reynolds number. The similarity of suspended sediment transport is increased through more accurate representation of suspended sediment concentration and carrying capacity of flow. The proposed method meets the needs of modelers by; maintaining the benefits found from distortion such as reduced cost, space, and model run-time; removing the need to apply scaled sediment or surrogate sediment; avoiding some of the scale effects and resulting errors of traditional flow and sediment transport scaling.
4. Non-Equilibrium Dynamics of Nano-channel Confined DNA: A Brownian Dynamics Simulation Study
Bhattacharya, Aniket; Huang, Aiqun; Reisner, Walter
We carry out Brownian dynamics (BD) simulation for a semi-flexible polymer chain characterized by a contour length Na and a persistence length lp confined inside a rectangular nanochannel to study its compression and retraction dynamics while being pushed on one end at a constant velocity by a nano-dozer''. We study the evolution of one dimensional concentration profile c (x , t) and the chain extension R along the channel axis (x-axis) during both the contracting as well as the retracting phases as a function of the velocity of the nano-dozer, both in steady states and in transients. Furthermore, we measure the transverse fluctuations of the chain under contraction and retraction, and the amplitude of the density profile, and compare these simulation results with those obtained from an analytical model proposed by Khorshid et al. Our studies are guided by recent experimental results by Khorshid et al. (Phys. Rev. Lett, 113, 268104 (2014)) and provide further justification to use a one dimensional PDE approach to understand the non-equilibrium dynamics of confined polymers.
5. Gliding flight in snakes: non-equilibrium trajectory dynamics and kinematics
Socha, Jake; Miklasz, Kevin; Jafari, Farid; Vlachos, Pavlos
2010-11-01
For animal gliders that live in trees, a glide trajectory begins in free fall and, given sufficient space, transitions to equilibrium gliding with no net forces on the body. However, the dynamics of non-equilibrium gliding are not well understood. Of any terrestrial animal glider, snakes may exhibit the most complicated glide patterns resulting from their highly active undulatory behavior. Our aim was to determine the characteristics of snake gliding during the transition to equilibrium. We launched "flying" snakes (Chrysopelea paradisi) from a 15 m tower and recorded the mid-to-end portion of trajectories with four videocameras to reconstruct the snake's 3D body position. Additionally, we developed a simple analytical model of gliding assuming only steady-state forces of lift, drag and weight acting on the body and used it to explore effects of wing loading, lift-to-drag ratio, and initial velocity on trajectory dynamics. Despite the vertical space provided to transition to steady-state gliding, snakes did not exhibit equilibrium gliding and in fact displayed a net positive acceleration in the vertical axis.
6. An investigation of an underwater steam plasma discharge as alternative to air plasmas for water purification
Gucker, Sarah N.; Foster, John E.; Garcia, Maria C.
2015-10-01
An underwater steam plasma discharge, in which water itself is the ionizing media, is investigated as a means to introduce advanced oxidation species into contaminated water for the purpose of water purification. The steam discharge avoids the acidification observed with air discharges and also avoids the need for a feed gas, simplifying the system. Steam discharge operation did not result in a pH changes in the processing of water or simulated wastewater, with the actual pH remaining roughly constant during processing. Simulated wastewater has been shown to continue to decompose significantly after steam treatment, suggesting the presence of long-lived plasma produced radicals. During steam discharge operation, nitrate production is limited, and nitrite production was found to be below the detection threshold of (roughly 0.2 mg L-1). The discharge was operated over a broad range of deposited power levels, ranging from approximately 30 W to 300 W. Hydrogen peroxide production was found to scale with increasing power. Additionally, the hydrogen peroxide production efficiency of the discharge was found to be higher than many of the rates reported in the literature to date.
7. Angularly Adaptive P1 - Double P0 Flux-Limited Diffusion Solutions of Non-Equilibrium Grey Radiative Transfer Problems
SciTech Connect
Brantley, P S
2006-08-08
The double spherical harmonics angular approximation in the lowest order, i.e. double P{sub 0} (DP{sub 0}), is developed for the solution of time-dependent non-equilibrium grey radiative transfer problems in planar geometry. Although the DP{sub 0} diffusion approximation is expected to be less accurate than the P{sub 1} diffusion approximation at and near thermodynamic equilibrium, the DP{sub 0} angular approximation can more accurately capture the complicated angular dependence near a non-equilibrium radiation wave front. In addition, the DP{sub 0} approximation should be more accurate in non-equilibrium optically thin regions where the positive and negative angular domains are largely decoupled. We develop an adaptive angular technique that locally uses either the DP{sub 0} or P{sub 1} flux-limited diffusion approximation depending on the degree to which the radiation and material fields are in thermodynamic equilibrium. Numerical results are presented for two test problems due to Su and Olson and to Ganapol and Pomraning for which semi-analytic transport solutions exist. These numerical results demonstrate that the adaptive P{sub 1}-DP{sub 0} diffusion approximation can yield improvements in accuracy over the standard P{sub 1} diffusion approximation, both without and with flux-limiting, for non-equilibrium grey radiative transfer.
8. Angularly Adaptive P1-Double P0 Flux-Limited Diffusion Solutions of Non-Equilibrium Grey Radiative Transfer Problems
SciTech Connect
Brantley, P S
2005-12-13
The double spherical harmonics angular approximation in the lowest order, i.e. double P{sub 0} (DP{sub 0}), is developed for the solution of time-dependent non-equilibrium grey radiative transfer problems in planar geometry. Although the DP{sub 0} diffusion approximation is expected to be less accurate than the P{sub 1} diffusion approximation at and near thermodynamic equilibrium, the DP{sub 0} angular approximation can more accurately capture the complicated angular dependence near a non-equilibrium radiation wave front. In addition, the DP{sub 0} approximation should be more accurate in non-equilibrium optically thin regions where the positive and negative angular domains are largely decoupled. We develop an adaptive angular technique that locally uses either the DP{sub 0} or P{sub 1} flux-limited diffusion approximation depending on the degree to which the radiation and material fields are in thermodynamic equilibrium. Numerical results are presented for two test problems due to Su and Olson and to Ganapol and Pomraning for which semi-analytic transport solutions exist. These numerical results demonstrate that the adaptive P{sub 1}-DP{sub 0} diffusion approximation can yield improvements in accuracy over the standard P{sub 1} diffusion approximation, both without and with flux-limiting, for non-equilibrium grey radiative transfer.
9. Enhanced laser-induced plasma channels in air
Yanlei, Zuo; Xiaofeng, Wei; Kainan, Zhou; Xiaoming, Zeng; Jingqin, Su; Zhihong, Jiao; Na, Xie; Zhaohui, Wu
2016-03-01
Plasma is a significant medium in high-energy density physics since it can hardly be damaged. For some applications such as plasma based backward Raman amplification (BRA), uniform high-density and large-scale plasma channels are required. In the previous experiment, the plasma transverse diameter and density are 50-200 μm and 1-2 × 1019 cm-3, here we enhance them to 0.8 mm and 8 × 1019 cm-3, respectively. Moreover, the gradient plasma is investigated in our experiment. A proper plasma gradient can be obtained with suitable pulse energy and delay. The experimental results are useful for plasma physics and nonlinear optics. Project supported by the Development Foundation of the Chinese Academy of Engineering Physics (Grant Nos. 2012A0401019 and 2013A0401019).
10. The energy pump and the origin of the non-equilibrium flux of the dynamical systems and the networks.
PubMed
Xu, Liufang; Shi, Hualin; Feng, Haidong; Wang, Jin
2012-04-28
The global stability of dynamical systems and networks is still challenging to study. We developed a landscape and flux framework to explore the global stability. The potential landscape is directly linked to the steady state probability distribution of the non-equilibrium dynamical systems which can be used to study the global stability. The steady state probability flux together with the landscape gradient determines the dynamics of the system. The non-zero probability flux implies the breaking down of the detailed balance which is a quantitative signature of the systems being in non-equilibrium states. We investigated the dynamics of several systems from monostability to limit cycle and explored the microscopic origin of the probability flux. We discovered that the origin of the probability flux is due to the non-equilibrium conditions on the concentrations resulting energy input acting like non-equilibrium pump or battery to the system. Another interesting behavior we uncovered is that the probabilistic flux is closely related to the steady state deterministic chemical flux. For the monostable model of the kinetic cycle, the analytical expression of the probabilistic flux is directly related to the deterministic flux, and the later is directly generated by the chemical potential difference from the adenosine triphosphate (ATP) hydrolysis. For the limit cycle of the reversible Schnakenberg model, we also show that the probabilistic flux is correlated to the chemical driving force, as well as the deterministic effective flux. Furthermore, we study the phase coherence of the stochastic oscillation against the energy pump, and argue that larger non-equilibrium pump results faster flux and higher coherence. This leads to higher robustness of the biological oscillations. We also uncovered how fluctuations influence the coherence of the oscillations in two steps: (1) The mild fluctuations influence the coherence of the system mainly through the probability flux while
11. DNA damage and mitochondria dysfunction in cell apoptosis induced by nonthermal air plasma
SciTech Connect
Kim, G. J.; Lee, J. K.; Kim, W.; Kim, K. T.
2010-01-11
Nonthermal plasma is known to induce animal cell death but the mechanism is not yet clear. Here, cellular and biochemical regulation of cell apoptosis is demonstrated for plasma treated cells. Surface type nonthermal air plasma triggered apoptosis of B16F10 mouse melanoma cancer cells causing DNA damage and mitochondria dysfunction. Plasma treatment activated caspase-3, apoptosis executioner. The plasma treated cells also accumulated gamma-H2A.X, marker for DNA double strand breaks, and p53 tumor suppressor gene as a response to DNA damage. Interestingly, cytochrome C was released from mitochondria and its membrane potential was changed significantly.
12. DNA damage and mitochondria dysfunction in cell apoptosis induced by nonthermal air plasma
Kim, G. J.; Kim, W.; Kim, K. T.; Lee, J. K.
2010-01-01
Nonthermal plasma is known to induce animal cell death but the mechanism is not yet clear. Here, cellular and biochemical regulation of cell apoptosis is demonstrated for plasma treated cells. Surface type nonthermal air plasma triggered apoptosis of B16F10 mouse melanoma cancer cells causing DNA damage and mitochondria dysfunction. Plasma treatment activated caspase-3, apoptosis executioner. The plasma treated cells also accumulated gamma-H2A.X, marker for DNA double strand breaks, and p53 tumor suppressor gene as a response to DNA damage. Interestingly, cytochrome C was released from mitochondria and its membrane potential was changed significantly.
13. Responses by pacific halibut to air exposure: Lack of correspondence among plasma constituents and mortality
USGS Publications Warehouse
Davis, M.W.; Schreck, C.B.
2005-01-01
Age-1 and age-2 Pacific halibut Hippoglossus stenolepis were exposed to a range of times in air (0-60 min) and air temperatures (10??C or 16??C) that simulated conditions on deck after capture to test for correspondence among responses in plasma constituents and mortality. Pacific halibut mortality generally did not correspond with cortisol, glucose, sodium, and potassium since the maximum observed plasma concentrations were reached after exposure to 30 min in air, while significant mortality occurred only after exposure to 40 min in air for age-1 fish and 60 min in air for age-2 fish. Predicting mortality in discarded Pacific halibut using these plasma constituents does not appear to be feasible. Lactate concentrations corresponded with mortality in age-1 fish exposed to 16??C and may be useful predictors of discard mortality under a limited set of fishing conditions.
14. Plasma flame for mass purification of contaminated air with chemical and biological warfare agents
SciTech Connect
Uhm, Han S.; Shin, Dong H.; Hong, Yong C.
2006-09-18
An elimination of airborne simulated chemical and biological warfare agents was carried out by making use of a plasma flame made of atmospheric plasma and a fuel-burning flame, which can purify the interior air of a large volume in isolated spaces such as buildings, public transportation systems, and military vehicles. The plasma flame generator consists of a microwave plasma torch connected in series to a fuel injector and a reaction chamber. For example, a reaction chamber, with the dimensions of a 22 cm diameter and 30 cm length, purifies an airflow rate of 5000 lpm contaminated with toluene (the simulated chemical agent) and soot from a diesel engine (the simulated aerosol for biological agents). Large volumes of purification by the plasma flame will free mankind from the threat of airborne warfare agents. The plasma flame may also effectively purify air that is contaminated with volatile organic compounds, in addition to eliminating soot from diesel engines as an environmental application.
15. Bimodality of low-redshift circumgalactic O VI in non-equilibrium EAGLE zoom simulations
Oppenheimer, Benjamin D.; Crain, Robert A.; Schaye, Joop; Rahmati, Alireza; Richings, Alexander J.; Trayford, James W.; Tumlinson, Jason; Bower, Richard G.; Schaller, Matthieu; Theuns, Tom
2016-08-01
We introduce a series of 20 cosmological hydrodynamical simulations of L* (M200 = 1011.7-1012.3 M⊙) and group-sized (M200 = 1012.7-1013.3 M⊙) haloes run with the model used for the EAGLE project, which additionally includes a non-equilibrium ionization and cooling module that follows 136 ions. The simulations reproduce the observed correlation, revealed by COS-Halos at z ˜ 0.2, between {O {VI}} column density at impact parameters b < 150 kpc and the specific star formation rate (sSFR ≡ SFR/M*) of the central galaxy at z ˜ 0.2. We find that the column density of circumgalactic {O {VI}} is maximal in the haloes associated with L* galaxies, because their virial temperatures are close to the temperature at which the ionization fraction of {O {VI}} peaks (T ˜ 105.5 K). The higher virial temperature of group haloes (>106 K) promotes oxygen to higher ionization states, suppressing the {O {VI}} column density. The observed N_{O {VI}}-sSFR correlation therefore does not imply a causal link, but reflects the changing characteristic ionization state of oxygen as halo mass is increased. In spite of the mass dependence of the oxygen ionization state, the most abundant circumgalactic oxygen ion in both L* and group haloes is {O VII}; {O {VI}} accounts for only 0.1 per cent of the oxygen in group haloes and 0.9-1.3 per cent with L* haloes. Nonetheless, the metals traced by {O {VI}} absorbers represent a fossil record of the feedback history of galaxies over a Hubble time; their characteristic epoch of ejection corresponds to z > 1 and much of the ejected metal mass resides beyond the virial radius of galaxies. For both L* and group galaxies, more of the oxygen produced and released by stars in the circumgalactic medium (within twice the virial radius) than in the stars and interstellar medium of the galaxy.
16. Structure and dynamics of concentration fluctuations in a non-equilibrium dense colloidal suspension.
PubMed
Giavazzi, Fabio; Savorana, Giovanni; Vailati, Alberto; Cerbino, Roberto
2016-08-21
Linearised fluctuating hydrodynamics describes effectively the concentration non-equilibrium fluctuations (NEF) arising during a diffusion process driven by a small concentration gradient. However, fluctuations in the presence of large gradients are not yet fully understood. Here we study the giant concentration NEF arising when a dense aqueous colloidal suspension is allowed to diffuse into an overlying layer of pure water. We use differential dynamic microscopy to determine both the statics and the dynamics of the fluctuations for several values of the wave-vector q. At small q, NEF are quenched by buoyancy, which prevents their full development and sets an upper timescale to their temporal relaxation. At intermediate q, the mean squared amplitude of NEF is characterised by a power law exponent -4, and fluctuations relax diffusively with diffusion coefficient D1. At large q, the amplitude of NEF vanishes and equilibrium concentration fluctuations are recovered, enabling a straightforward determination of the osmotic compressibility of the suspension during diffusion. In this q-range we also find that the relaxation of the fluctuations occurs with a diffusion coefficient D2 significantly different from D1. Both diffusion coefficients exhibit time-dependence with D1 increasing monotonically (by about 15%) and D2 showing the opposite behaviour (about 17% decrease). At equilibrium, the two coefficients coincide as expected. While the decrease of D2 is compatible with a diffusive evolution of the concentration profile, the increase of D1 is still not fully understood and may require considering nonlinearities that are neglected in current theories for highly stressed colloids.
17. Entropic screening preserves non-equilibrium nature of nematic phase while enthalpic screening destroys it.
PubMed
Dan, K; Roy, M; Datta, A
2016-02-14
The present manuscript describes the role of entropic and enthalpic forces mediated by organic non-polar (hexane) and polar (methanol) solvents on the bulk and microscopic phase transition of a well known nematic liquid crystalline material MBBA (N-(4-methoxybenzylidene)-4-butylaniline) through Differential Scanning calorimetry (DSC), UV-Visible (UV-Vis), and Fourier Transform Infrared (FTIR) spectroscopy. DSC study indicates continuous linear decreases in both nematic-isotropic (N-I) phase transition temperature and enthalpy of MBBA in presence of hexane while both these parameters show a saturation after an initial decay in methanol. These distinct transitional behaviours were explained in terms of the "depletion force" model for entropic screening in hexane and "screening-self-screening" model for methanol. Heating rate dependent DSC studies find that non-Arrhenius behaviour, characteristic of pristine MBBA and a manifestation of non-equilibrium nature [Dan et al., J. Chem. Phys. 143, 094501 (2015)], is preserved in presence of entropic screening in the hexane solution, while it changes to Arrhenius behaviour (signifying equilibrium behaviour) in presence of enthalpic screening in methanol solution. FTIR spectra show similar dependence on the solvent induced screening in the intensities of the imine (-C = N) stretch and the out-of-plane distortion vibrations of the benzene rings of MBBA with hexane and methanol as in DSC, further establishing our entropic and enthalpic screening models. UV-Vis spectra of the electronic transitions in MBBA as a function of temperature also exhibit different dependences of intensities on the solvent induced screening, and an exponential decrease is observed in presence of hexane while methanol completely changes the nature of interaction to follow a linear dependence. PMID:26874498
18. 2-D Modeling of Nanoscale MOSFETs: Non-Equilibrium Green's Function Approach
NASA Technical Reports Server (NTRS)
Svizhenko, Alexei; Anantram, M. P.; Govindan, T. R.; Biegel, Bryan
2001-01-01
We have developed physical approximations and computer code capable of realistically simulating 2-D nanoscale transistors, using the non-equilibrium Green's function (NEGF) method. This is the most accurate full quantum model yet applied to 2-D device simulation. Open boundary conditions and oxide tunneling are treated on an equal footing. Electrons in the ellipsoids of the conduction band are treated within the anisotropic effective mass approximation. Electron-electron interaction is treated within Hartree approximation by solving NEGF and Poisson equations self-consistently. For the calculations presented here, parallelization is performed by distributing the solution of NEGF equations to various processors, energy wise. We present simulation of the "benchmark" MIT 25nm and 90nm MOSFETs and compare our results to those from the drift-diffusion simulator and the quantum-corrected results available. In the 25nm MOSFET, the channel length is less than ten times the electron wavelength, and the electron scattering time is comparable to its transit time. Our main results are: (1) Simulated drain subthreshold current characteristics are shown, where the potential profiles are calculated self-consistently by the corresponding simulation methods. The current predicted by our quantum simulation has smaller subthreshold slope of the Vg dependence which results in higher threshold voltage. (2) When gate oxide thickness is less than 2 nm, gate oxide leakage is a primary factor which determines off-current of a MOSFET (3) Using our 2-D NEGF simulator, we found several ways to drastically decrease oxide leakage current without compromising drive current. (4) Quantum mechanically calculated electron density is much smaller than the background doping density in the poly silicon gate region near oxide interface. This creates an additional effective gate voltage. Different ways to. include this effect approximately will be discussed.
19. Construction of Low Dissipative High Order Well-Balanced Filter Schemes for Non-Equilibrium Flows
NASA Technical Reports Server (NTRS)
Wang, Wei; Yee, H. C.; Sjogreen, Bjorn; Magin, Thierry; Shu, Chi-Wang
2009-01-01
The goal of this paper is to generalize the well-balanced approach for non-equilibrium flow studied by Wang et al. [26] to a class of low dissipative high order shock-capturing filter schemes and to explore more advantages of well-balanced schemes in reacting flows. The class of filter schemes developed by Yee et al. [30], Sjoegreen & Yee [24] and Yee & Sjoegreen [35] consist of two steps, a full time step of spatially high order non-dissipative base scheme and an adaptive nonlinear filter containing shock-capturing dissipation. A good property of the filter scheme is that the base scheme and the filter are stand alone modules in designing. Therefore, the idea of designing a well-balanced filter scheme is straightforward, i.e., choosing a well-balanced base scheme with a well-balanced filter (both with high order). A typical class of these schemes shown in this paper is the high order central difference schemes/predictor-corrector (PC) schemes with a high order well-balanced WENO filter. The new filter scheme with the well-balanced property will gather the features of both filter methods and well-balanced properties: it can preserve certain steady state solutions exactly; it is able to capture small perturbations, e.g., turbulence fluctuations; it adaptively controls numerical dissipation. Thus it shows high accuracy, efficiency and stability in shock/turbulence interactions. Numerical examples containing 1D and 2D smooth problems, 1D stationary contact discontinuity problem and 1D turbulence/shock interactions are included to verify the improved accuracy, in addition to the well-balanced behavior.
20. Topics in Non-Equilibrium Dynamics and the Emergence of Spacetime
Engelhardt, Dalit
The Anti-de Sitter / Conformal Field Theory (AdS/CFT) correspondence that arises in string theory has had implications for the study of phenomena across a range of subfields in physics, from spacetime geometry to the behavior of condensed matter systems. Two major themes that have featured prominently in these investigations have been the behavior of systems out of equilibrium, and the emergence of spacetime. In this thesis, aspects of these themes are considered and analyzed. The question of equilibration and thermalization in 2D conformal field theories is addressed and refined via a number of observations about local versus global thermalization in such systems, the validity of particular diagnostics of thermalization, the dependence of the equilibration behavior of a conformal field theory on its operator spectrum, and the holographic dual of the generalized Gibbs ensemble that is of interest in studies of equilibration in systems with a large number of conserved quantities. A formalism for analyzing the non-equilibrium dynamics of 1+1-dimensional conformal field theories is discussed, and its physical relevance is motivated with an example connecting such a system to an experimental system that exhibited unusual equilibration behavior. Qualitative agreement is demonstrated between the CFT picture and the experimental observations. The emergence of spacetime geometry from quantum entanglement, while largely a byproduct of considerations from holographic dualities, has also been proposed to have a direct, non-holographic manifestation. Here a particular realization of such a direct emergence is presented through a demonstration that, in the presence of quantum entanglement alone, certain observations of electric fields in the entangled system appear qualitatively the same as the corresponding observations in a physically-connected geometric spacetime, so that the entanglement effectively mimics particular features associated with geometric connectivity.
1. SDSS J141624.08+134826.7: Blue L dwarfs and Non-equilibrium Chemistry
Cushing, Michael C.; Saumon, D.; Marley, Mark S.
2010-11-01
We present an analysis of the recently discovered blue L dwarf SDSS J141624.08+134826.7. We extend the spectral coverage of its published spectrum to ~4 μm by obtaining a low-resolution L-band spectrum with SpeX on the NASA IRTF. The spectrum exhibits a tentative weak CH4 absorption feature at 3.3 μm but is otherwise featureless. We derive the atmospheric parameters of SDSS J141624.08+134826.7 by comparing its 0.7-4.0 μm spectrum to the atmospheric models of Marley and Saumon which include the effects of both condensate cloud formation and non-equilibrium chemistry due to vertical mixing and find the best-fitting model has T eff = 1700 K, log g = 5.5 (cm s-2), f sed = 4, and K zz = 104 cm2 s-1. The derived effective temperature is significantly cooler than previously estimated but we confirm the suggestion by Bowler et al. that the peculiar spectrum of SDSS J141624.08+134826.7 is primarily a result of thin condensate clouds. In addition, we find strong evidence of vertical mixing in the atmosphere of SDSS J141624.08+134826.7 based on the absence of the deep 3.3 μm CH4 absorption band predicted by models computed in chemical equilibrium. Finally, this result suggests that observations of blue L dwarfs are an appealing way to quantitatively estimate the vigor of mixing in the atmospheres of L dwarfs because of the dramatic impact such mixing has on the strength of the 3.3 μm CH4 band in the emergent spectra of L dwarfs with thin condensate clouds.
2. Non-equilibrium simulations of thermally induced electric fields in water
Wirnsberger, P.; Fijan, D.; Šarić, A.; Neumann, M.; Dellago, C.; Frenkel, D.
2016-06-01
Using non-equilibrium molecular dynamics simulations, it has been recently demonstrated that water molecules align in response to an imposed temperature gradient, resulting in an effective electric field. Here, we investigate how thermally induced fields depend on the underlying treatment of long-ranged interactions. For the short-ranged Wolf method and Ewald summation, we find the peak strength of the field to range between 2 × 107 and 5 × 107 V/m for a temperature gradient of 5.2 K/Å. Our value for the Wolf method is therefore an order of magnitude lower than the literature value [J. A. Armstrong and F. Bresme, J. Chem. Phys. 139, 014504 (2013); J. Armstrong et al., J. Chem. Phys. 143, 036101 (2015)]. We show that this discrepancy can be traced back to the use of an incorrect kernel in the calculation of the electrostatic field. More seriously, we find that the Wolf method fails to predict correct molecular orientations, resulting in dipole densities with opposite sign to those computed using Ewald summation. By considering two different multipole expansions, we show that, for inhomogeneous polarisations, the quadrupole contribution can be significant and even outweigh the dipole contribution to the field. Finally, we propose a more accurate way of calculating the electrostatic potential and the field. In particular, we show that averaging the microscopic field analytically to obtain the macroscopic Maxwell field reduces the error bars by up to an order of magnitude. As a consequence, the simulation times required to reach a given statistical accuracy decrease by up to two orders of magnitude.
3. Many-body quantum electrodynamics networks: Non-equilibrium condensed matter physics with light
Le Hur, Karyn; Henriet, Loïc; Petrescu, Alexandru; Plekhanov, Kirill; Roux, Guillaume; Schiró, Marco
2016-10-01
We review recent developments regarding the quantum dynamics and many-body physics with light, in superconducting circuits and Josephson analogues, by analogy with atomic physics. We start with quantum impurity models addressing dissipative and driven systems. Both theorists and experimentalists are making efforts towards the characterization of these non-equilibrium quantum systems. We show how Josephson junction systems can implement the equivalent of the Kondo effect with microwave photons. The Kondo effect can be characterized by a renormalized light frequency and a peak in the Rayleigh elastic transmission of a photon. We also address the physics of hybrid systems comprising mesoscopic quantum dot devices coupled with an electromagnetic resonator. Then, we discuss extensions to Quantum Electrodynamics (QED) Networks allowing one to engineer the Jaynes-Cummings lattice and Rabi lattice models through the presence of superconducting qubits in the cavities. This opens the door to novel many-body physics with light out of equilibrium, in relation with the Mott-superfluid transition observed with ultra-cold atoms in optical lattices. Then, we summarize recent theoretical predictions for realizing topological phases with light. Synthetic gauge fields and spin-orbit couplings have been successfully implemented in quantum materials and with ultra-cold atoms in optical lattices - using time-dependent Floquet perturbations periodic in time, for example - as well as in photonic lattice systems. Finally, we discuss the Josephson effect related to Bose-Hubbard models in ladder and two-dimensional geometries, producing phase coherence and Meissner currents. The Bose-Hubbard model is related to the Jaynes-Cummings lattice model in the large detuning limit between light and matter (the superconducting qubits). In the presence of synthetic gauge fields, we show that Meissner currents subsist in an insulating Mott phase.
4. Structure and dynamics of concentration fluctuations in a non-equilibrium dense colloidal suspension.
PubMed
Giavazzi, Fabio; Savorana, Giovanni; Vailati, Alberto; Cerbino, Roberto
2016-08-21
Linearised fluctuating hydrodynamics describes effectively the concentration non-equilibrium fluctuations (NEF) arising during a diffusion process driven by a small concentration gradient. However, fluctuations in the presence of large gradients are not yet fully understood. Here we study the giant concentration NEF arising when a dense aqueous colloidal suspension is allowed to diffuse into an overlying layer of pure water. We use differential dynamic microscopy to determine both the statics and the dynamics of the fluctuations for several values of the wave-vector q. At small q, NEF are quenched by buoyancy, which prevents their full development and sets an upper timescale to their temporal relaxation. At intermediate q, the mean squared amplitude of NEF is characterised by a power law exponent -4, and fluctuations relax diffusively with diffusion coefficient D1. At large q, the amplitude of NEF vanishes and equilibrium concentration fluctuations are recovered, enabling a straightforward determination of the osmotic compressibility of the suspension during diffusion. In this q-range we also find that the relaxation of the fluctuations occurs with a diffusion coefficient D2 significantly different from D1. Both diffusion coefficients exhibit time-dependence with D1 increasing monotonically (by about 15%) and D2 showing the opposite behaviour (about 17% decrease). At equilibrium, the two coefficients coincide as expected. While the decrease of D2 is compatible with a diffusive evolution of the concentration profile, the increase of D1 is still not fully understood and may require considering nonlinearities that are neglected in current theories for highly stressed colloids. PMID:27425869
5. Entropic screening preserves non-equilibrium nature of nematic phase while enthalpic screening destroys it
Dan, K.; Roy, M.; Datta, A.
2016-02-01
The present manuscript describes the role of entropic and enthalpic forces mediated by organic non-polar (hexane) and polar (methanol) solvents on the bulk and microscopic phase transition of a well known nematic liquid crystalline material MBBA (N-(4-methoxybenzylidene)-4-butylaniline) through Differential Scanning calorimetry (DSC), UV-Visible (UV-Vis), and Fourier Transform Infrared (FTIR) spectroscopy. DSC study indicates continuous linear decreases in both nematic-isotropic (N-I) phase transition temperature and enthalpy of MBBA in presence of hexane while both these parameters show a saturation after an initial decay in methanol. These distinct transitional behaviours were explained in terms of the "depletion force" model for entropic screening in hexane and "screening-self-screening" model for methanol. Heating rate dependent DSC studies find that non-Arrhenius behaviour, characteristic of pristine MBBA and a manifestation of non-equilibrium nature [Dan et al., J. Chem. Phys. 143, 094501 (2015)], is preserved in presence of entropic screening in the hexane solution, while it changes to Arrhenius behaviour (signifying equilibrium behaviour) in presence of enthalpic screening in methanol solution. FTIR spectra show similar dependence on the solvent induced screening in the intensities of the imine (—C = N) stretch and the out-of-plane distortion vibrations of the benzene rings of MBBA with hexane and methanol as in DSC, further establishing our entropic and enthalpic screening models. UV-Vis spectra of the electronic transitions in MBBA as a function of temperature also exhibit different dependences of intensities on the solvent induced screening, and an exponential decrease is observed in presence of hexane while methanol completely changes the nature of interaction to follow a linear dependence.
6. Efficient hybrid non-equilibrium molecular dynamics--Monte Carlo simulations with symmetric momentum reversal.
PubMed
Chen, Yunjie; Roux, Benoît
2014-09-21
Hybrid schemes combining the strength of molecular dynamics (MD) and Metropolis Monte Carlo (MC) offer a promising avenue to improve the sampling efficiency of computer simulations of complex systems. A number of recently proposed hybrid methods consider new configurations generated by driving the system via a non-equilibrium MD (neMD) trajectory, which are subsequently treated as putative candidates for Metropolis MC acceptance or rejection. To obey microscopic detailed balance, it is necessary to alter the momentum of the system at the beginning and/or the end of the neMD trajectory. This strict rule then guarantees that the random walk in configurational space generated by such hybrid neMD-MC algorithm will yield the proper equilibrium Boltzmann distribution. While a number of different constructs are possible, the most commonly used prescription has been to simply reverse the momenta of all the particles at the end of the neMD trajectory ("one-end momentum reversal"). Surprisingly, it is shown here that the choice of momentum reversal prescription can have a considerable effect on the rate of convergence of the hybrid neMD-MC algorithm, with the simple one-end momentum reversal encountering particularly acute problems. In these neMD-MC simulations, different regions of configurational space end up being essentially isolated from one another due to a very small transition rate between regions. In the worst-case scenario, it is almost as if the configurational space does not constitute a single communicating class that can be sampled efficiently by the algorithm, and extremely long neMD-MC simulations are needed to obtain proper equilibrium probability distributions. To address this issue, a novel momentum reversal prescription, symmetrized with respect to both the beginning and the end of the neMD trajectory ("symmetric two-ends momentum reversal"), is introduced. Illustrative simulations demonstrate that the hybrid neMD-MC algorithm robustly yields a correct
7. Star formation and molecular hydrogen in dwarf galaxies: a non-equilibrium view
Hu, Chia-Yu; Naab, Thorsten; Walch, Stefanie; Glover, Simon C. O.; Clark, Paul C.
2016-06-01
We study the connection of star formation to atomic (H I) and molecular hydrogen (H2) in isolated, low-metallicity dwarf galaxies with high-resolution (mgas = 4 M⊙, Nngb = 100) smoothed particle hydrodynamics simulations. The model includes self-gravity, non-equilibrium cooling, shielding from a uniform and constant interstellar radiation field, the chemistry of H2 formation, H2-independent star formation, supernova feedback and metal enrichment. We find that the H2 mass fraction is sensitive to the adopted dust-to-gas ratio and the strength of the interstellar radiation field, while the star formation rate is not. Star formation is regulated by stellar feedback, keeping the gas out of thermal equilibrium for densities n < 1 cm-3. Because of the long chemical time-scales, the H2 mass remains out of chemical equilibrium throughout the simulation. Star formation is well correlated with cold (T ≤ 100 K) gas, but this dense and cold gas - the reservoir for star formation - is dominated by H I, not H2. In addition, a significant fraction of H2 resides in a diffuse, warm phase, which is not star-forming. The interstellar medium is dominated by warm gas (100 K < T ≤ 3 × 104 K) both in mass and in volume. The scaleheight of the gaseous disc increases with radius while the cold gas is always confined to a thin layer in the mid-plane. The cold gas fraction is regulated by feedback at small radii and by the assumed radiation field at large radii. The decreasing cold gas fractions result in a rapid increase in depletion time (up to 100 Gyr) for total gas surface densities Σ _{H I+H_2} ≲ 10 M⊙ pc-2, in agreement with observations of dwarf galaxies in the Kennicutt-Schmidt plane.
8. Non-equilibrium phase map, optical and electrical properties of Cu-Zn-O alloys
Subramaniyan, Archana; Perkins, John; O'Hayre, Ryan; Ginley, David; Lany, Stephan; Zakutayev, Andriy
2014-03-01
Cuprous oxide (Cu2O) is a candidate p-type solar cell absorber material that has been spotlighted recently due to its low cost, earth abundant and non-toxic nature. The maximum reported efficiency of Cu2O based solar cells is rather low (5. 38%) and it can in part be attributed its forbidden direct band gap (2.1 eV) and higher absorption threshold (2.6 eV). Here, we alloy Cu2O with ZnO via combinatorial RF magnetron sputtering as a function of temperature (T) and composition at fixed 20 mTorr Ar pressure to modify the electronic band structure and reduce its absorption threshold, which can potentially enhance the solar cell performance. A non-equilibrium Cu-Zn-O phase map was generated in the T range 100 - 400 °C and Zn composition 0 - 37 at%. Highly crystalline Cu2O structured Cu-Zn-O alloys with Zn content of 0 to 17 at% were synthesized in the T range 200 - 270 °C. With increasing Zn at%, the preferential orientation in Cu-Zn-O alloy changes from (200) to (111) direction. At lower T (<200 °C), either amorphous or poor crystalline Cu2O structured alloys were observed, whereas at higher T (>270 ° C) and higher Zn composition (>25 at%), CuO or ZnO second phases were observed. The absorption coefficient of all Cu-Zn-O alloys was higher than that of phase pure Cu2O. The absorption threshold () was also reduced significantly, for example, at = 2*104 cm-1 the absorption threshold of Cu-Zn-O alloy with 10 at% Zn reduced from 2.4 eV to 2.1 eV. The electrical conductivity of all Cu-Zn-O alloys was measured to be within 2 - 5 mS/cm.
9. Optical Diagnostics of Air Flows Induced in Surface Dielectric Barrier Discharge Plasma Actuator
Kobatake, Takuya; Deguchi, Masanori; Suzuki, Junya; Eriguchi, Koji; Ono, Kouichi
2014-10-01
A surface dielectric barrier discharge (SDBD) plasma actuator has recently been intensively studied for the flow control over airfoils and turbine blades in the fields of aerospace and aeromechanics. It consists of two electrodes placed on both sides of the dielectric, where one is a top powered electrode exposed to the air, and the other is a bottom grounded electrode encapsulated with an insulator. The unidirectional gas flow along the dielectric surfaces is induced by the electrohydrodynamic (EHD) body force. It is known that the thinner the exposed electrode, the greater the momentum transfer to the air is, indicating that the thickness of the plasma is important. To analyze plasma profiles and air flows induced in the SDBD plasma actuator, we performed time-resolved and -integrated optical emission and schlieren imaging of the side view of the SDBD plasma actuator in atmospheric air. We applied a high voltage bipolar pulse (4-8 kV, 1-10 kHz) between electrodes. Experimental results indicated that the spatial extent of the plasma is much smaller than that of the induced flows. Experimental results further indicated that in the positive-going phase, a thin and long plasma is generated, where the optical emission is weak and uniform; on the other hand, in the negative-going phase, a thick and short plasma is generated, where a strong optical emission is observed near the top electrode.
10. Generation of High-Density Electrons Based on Plasma Grating Induced Bragg Diffraction in Air
SciTech Connect
Shi Liping; Li Wenxue; Wang Yongdong; Lu Xin; Ding Liang'en; Zeng Heping
2011-08-26
Efficient nonlinear Bragg diffraction was observed as an intense infrared femtosecond pulse was focused on a plasma grating induced by interference between two ultraviolet femtosecond laser pulses in air. The preformed electrons inside the plasma grating were accelerated by subsequent intense infrared laser pulses, inducing further collisional ionization and significantly enhancing the local electron density.
11. Targeting cancer cells with reactive oxygen and nitrogen species generated by atmospheric-pressure air plasma.
PubMed
Ahn, Hak Jun; Kim, Kang Il; Hoan, Nguyen Ngoc; Kim, Churl Ho; Moon, Eunpyo; Choi, Kyeong Sook; Yang, Sang Sik; Lee, Jong-Soo
2014-01-01
The plasma jet has been proposed as a novel therapeutic method for cancer. Anticancer activity of plasma has been reported to involve mitochondrial dysfunction. However, what constituents generated by plasma is linked to this anticancer process and its mechanism of action remain unclear. Here, we report that the therapeutic effects of air plasma result from generation of reactive oxygen/nitrogen species (ROS/RNS) including H2O2, Ox, OH-, •O2, NOx, leading to depolarization of mitochondrial membrane potential and mitochondrial ROS accumulation. Simultaneously, ROS/RNS activate c-Jun NH2-terminal kinase (JNK) and p38 kinase. As a consequence, treatment with air plasma jets induces apoptotic death in human cervical cancer HeLa cells. Pretreatment of the cells with antioxidants, JNK and p38 inhibitors, or JNK and p38 siRNA abrogates the depolarization of mitochondrial membrane potential and impairs the air plasma-induced apoptotic cell death, suggesting that the ROS/RNS generated by plasma trigger signaling pathways involving JNK and p38 and promote mitochondrial perturbation, leading to apoptosis. Therefore, administration of air plasma may be a feasible strategy to eliminate cancer cells.
12. Characterization of an atmospheric pressure air plasma source for polymer surface modification
Yang, Shujun; Tang, Jiansheng
2013-10-01
An atmospheric pressure air plasma source was generated through dielectric barrier discharge (DBD). It was used to modify polyethyleneterephthalate (PET) surfaces with very high throughput. An equivalent circuit model was used to calculate the peak average electron density. The emission spectrum from the plasma was taken and the main peaks in the spectrum were identified. The ozone density in the down plasma region was estimated by Absorption Spectroscopy. NSF and ARC-ODU
13. Numerical Investigation of Radiative Heat Transfer in Laser Induced Air Plasmas
NASA Technical Reports Server (NTRS)
Liu, J.; Chen, Y. S.; Wang, T. S.; Turner, James E. (Technical Monitor)
2001-01-01
14. Linking plasma kinetics to plasma-bio interactions
Bruggeman, Peter
2015-05-01
Cold non-equilibrium atmospheric pressure plasmas have received a lot of attention in the last decade due to their huge potential for biomedical applications. In my group, we have characterized an RF driven APPJ in great detail. The characterization includes electrical measurements, imaging, optical emission spectroscopy, (two photon enhanced) laser induced fluorescence, Thomson scattering, Rayleigh scattering, Raman scattering and mass spectrometry. This led to a detailed knowledge of the electron density, electron temperature, gas temperature, NO, O, OH, O3 densities, ionic species and air concentrations in the plasma effluent. Living organisms for in vitro studies are typically kept in complex solutions or culture media. Plasma-bio interactions involves not only the production of reactive species in the plasma gas phase but also transport to the liquid phase and plasma induced liquid phase chemistry and its impact on the living organisms. Reactive nitrogen and oxygen species have been identified as the key reactive species. Recent results of my group show that controlling the gas phase plasma chemistry can lead to significant different biological responses of the living organisms corresponding to different chemical pathways. The effect of plasma jet interaction with liquids containing mammalian cells, bacteria and virus will be discussed. The outcomes of these studies allow unraveling chemical pathways responsible for plasma-bio interactions and linking plasma kinetics to plasma-bio interactions.
15. Open-air direct current plasma jet: Scaling up, uniformity, and cellular control
Wu, S.; Wang, Z.; Huang, Q.; Lu, X.; Ostrikov, K.
2012-10-01
Atmospheric-pressure plasma jets are commonly used in many fields from medicine to nanotechnology, yet the issue of scaling the discharges up to larger areas without compromising the plasma uniformity remains a major challenge. In this paper, we demonstrate a homogenous cold air plasma glow with a large cross-section generated by a direct current power supply. There is no risk of glow-to-arc transitions, and the plasma glow appears uniform regardless of the gap between the nozzle and the surface being processed. Detailed studies show that both the position of the quartz tube and the gas flow rate can be used to control the plasma properties. Further investigation indicates that the residual charges trapped on the inner surface of the quartz tube may be responsible for the generation of the air plasma plume with a large cross-section. The spatially resolved optical emission spectroscopy reveals that the air plasma plume is uniform as it propagates out of the nozzle. The remarkable improvement of the plasma uniformity is used to improve the bio-compatibility of a glass coverslip over a reasonably large area. This improvement is demonstrated by a much more uniform and effective attachment and proliferation of human embryonic kidney 293 (HEK 293) cells on the plasma-treated surface.
16. OH(A,X) radicals in microwave plasma-assisted combustion of methane/air
Wu, Wei; Fuh, Che; Wang, Chuji; Laser Spectroscopy and Plasma Team
2014-10-01
A novel microwave plasma-assisted combustion (PAC) system, which consists of a microwave plasma-assisted combustor, a gas flow control manifold, and a set of optical diagnostic systems, was developed as a new test platform to study plasma enhancement of combustion. Using this system, we studied the state-resolved OH(A,X) radicals in the plasma-assisted combustion and ignition of a methane/air mixture. Experimental results identified three reaction zones in the plasma-assisted combustor: the plasma zone, the hybrid plasma-flame zone, and the flame zone. The OH(A) radicals in the three distinct zones were characterized using optical emission spectroscopy (OES). Results showed a surge of OH(A) radicals in the hybrid zone compared to the plasma zone and the flame zone. The OH(X) radicals in the flame zone were measured using cavity ringdown spectroscopy (CRDS), and the absolute number density distribution of OH(X) was quantified in two-dimension. The effect of microwave argon plasma on combustion was studied with two different fuel/oxidizer injection patterns, namely the premixed methane/air injection and the nonpremixed (separate) methane/air injection. Parameters investigated included the flame geometry, the lean flammability limit, the emission spectra, and rotational temperature. State-resolved OH(A,X) radicals in the PAC of both injection patterns were also compared. This work is supported by the National Science Foundation through the Grant No. CBET-1066486.
17. Open-air direct current plasma jet: Scaling up, uniformity, and cellular control
SciTech Connect
Wu, S.; Wang, Z.; Huang, Q.; Lu, X.; Ostrikov, K.
2012-10-15
Atmospheric-pressure plasma jets are commonly used in many fields from medicine to nanotechnology, yet the issue of scaling the discharges up to larger areas without compromising the plasma uniformity remains a major challenge. In this paper, we demonstrate a homogenous cold air plasma glow with a large cross-section generated by a direct current power supply. There is no risk of glow-to-arc transitions, and the plasma glow appears uniform regardless of the gap between the nozzle and the surface being processed. Detailed studies show that both the position of the quartz tube and the gas flow rate can be used to control the plasma properties. Further investigation indicates that the residual charges trapped on the inner surface of the quartz tube may be responsible for the generation of the air plasma plume with a large cross-section. The spatially resolved optical emission spectroscopy reveals that the air plasma plume is uniform as it propagates out of the nozzle. The remarkable improvement of the plasma uniformity is used to improve the bio-compatibility of a glass coverslip over a reasonably large area. This improvement is demonstrated by a much more uniform and effective attachment and proliferation of human embryonic kidney 293 (HEK 293) cells on the plasma-treated surface.
18. New zinc-glycine-iodide complexes as a product of equilibrium and non-equilibrium crystallization in the Gly - ZnI2 - H2O system
Tepavitcharova, S.; Havlíček, D.; Matulková, I.; Rabadjieva, D.; Gergulova, R.; Plocek, J.; Němec, I.; Císařová, I.
2016-09-01
Equilibrium crystallization of two anhydrous complex compounds, [Zn(gly)2I2] and [Zn(gly)I2], and non-equilibrium crystallization of the [Zn3(H2O)4(μ-gly)2I6] complex have been observed in the Gly - ZnI2 - H2O system at 25°C. Different mixed zinc-glycine-iodide-aqua complexes exist in the studied solutions and those with the highest activity are responsible for the crystallization process. The stable [ZnI2O2(2Gly)]0 complexes are responsible for the large equilibrium crystallization field of the compound [Zn(gly)2I2] (monoclinic system, C2/c space group), in whose crystal structure they are incorporated as discrete distorted electroneutral tetrahedra. In zinc-iodide solutions with a low water activity it is more probable that the glycine zwitterions act as bidentate ligands and form polynuclear complexes. We assume the [ZnI2O2(2/2Gly)]0 infinite chains build the compound [Zn(gly)I2], for which we have found a narrow equilibrium crystallization field. We have failed to describe the crystal structure of this compound because of its limited stability in the air. Non-equilibrium crystallization of [Zn3(H2O)4(μ-gly)2I6] (triclinic system, P-1 space group) was demonstrated, with crystal structure built by trinuclear complexes [ZnI3O(1/2Gly)] [ZnO4(4H2O)O2(2/2Gly)(trans)][ZnI3O(1/2Gly)]. The FTIR and Raman spectra and also the thermal behaviour of the three compounds were discussed.
19. Atmospheric pressure air-plasma jet evolved from microdischarges: Eradication of E. coli with the jet
SciTech Connect
Hong, Yong Cheol; Kang, Won Seok; Hong, Yoo Beom; Yi, Won Ju; Uhm, Han Sup
2009-12-15
An atmospheric-pressure air-plasma jet operating at 60 Hz ac is presented. A plasma jet with a length of 23 mm was produced by feeding air through a porous alumina dielectric installed between an outer electrode and a hollow inner electrode. Microdischarges in the porous alumina are ejected as a plasma jet from the outer electrode through a 1 mm hole, showing that the temperature of the jet decreases to a value close to the room temperature. The jet disinfects E. coli cells very effectively, eradicating them with an exposure of a few seconds to the jet flame.
20. A plasma needle for generating homogeneous discharge in atmospheric pressure air
SciTech Connect
Li Xuechen; Yuan Ning; Jia Pengying; Chen Junying
2010-09-15
Homogeneous discharge in air is often considered to be the ultimate low-temperature atmospheric pressure plasmas for industrial applications. In this paper, we present a method whereby stable homogeneous discharge in open air can be generated by a simple plasma needle. The discharge mechanism is discussed based on the spatially resolved light emission waveforms from the plasma. Optical emission spectroscopy is used to determine electron energy and rotational temperature, and results indicate that both electron energy and rotational temperature increase with increasing the applied voltage. The results are analyzed qualitatively based on the discharge mechanism.
1. Effects of resident water and non-equilibrium adsorption on the primary and enhanced coalbed methane gas recovery
Jahediesfanjani, Hossein
The major part of the gas in coalbed methane and shale gas reservoirs is stored as the adsorbed gas in the coal and organic materials of the black shale internal surfaces. The sorption sites in both reservoirs are composed of several macropores that contain very small pore sizes. Therefore, the adsorption/desorption is very slow process and follows a non-equilibrium trend. The time-dependency of the sorption process is further affected by the reservoir resident water. Water can diffuse into the matrix and adsorption sites, plug the pores and affect the reservoir gas production. This study presents an experimental and theoretical procedure to investigate the effects of the resident water and time-dependency of the sorption process on coalbed and shale gas primary and enhanced recovery by simultaneous CO 2/N2 injection. Series of the experiments are conducted to construct both equilibrium and non-equilibrium single and multi-component isotherms with the presence of water. A novel and rapid data interpretation technique is developed based on the nonequilibrium adsorption/desorption thermodynamics, mass conservation law, and volume filling adsorption theory. The developed technique is implemented to construct both equilibrium and non-equilibrium multi-component multi-phase isotherms from the early time experimental measurements. The non-equilibrium isotherms are incorporated in the coalbed methane/shale gas reservoir simulations to account for the time-dependency of the sorption process. The experimental results indicate that the presence of water in the sorption system reduces both carbon dioxide and nitrogen adsorption rates. Reduction in the adsorption rate for carbon dioxide is more than nitrogen. The results also indicate that the resident water reduces the adsorption ability of low rank coals more than high rank ones. The results of the multi-component sorption tests indicate that increasing the initial mole fraction of the nitrogen gas in the injected CO2/N2
2. Final Report for Project: Impacts of stratification and non-equilibrium winds and waves on hub-height winds
SciTech Connect
Patton, Edward G.
2015-07-14
This project used a combination of turbulence-resolving large-eddy simulations, single-column modeling (where turbulence is parameterized), and currently available observations to improve, assess, and develop a parameterization of the impact of non-equilibrium wave states and stratification on the buoy-observed winds to establish reliable wind data at the turbine hub-height level. Analysis of turbulence-resolving simulations and observations illuminates the non-linear coupling between the atmosphere and the undulating sea surface. This analysis guides modification of existing boundary layer parameterizations to include wave influences for upward extrapolation of surface-based observations through the turbine layer. Our surface roughness modifications account for the interaction between stratification and the effects of swell’s amplitude and wavelength as well as swell’s relative motion with respect to the mean wind direction. The single-column version of the open source Weather and Research Forecasting (WRF) model (Skamarock et al., 2008) serves as our platform to test our proposed planetary boundary layer parameterization modifications that account for wave effects on marine atmospheric boundary layer flows. WRF has been widely adopted for wind resource analysis and forecasting. The single column version is particularly suitable to development, analysis, and testing of new boundary layer parameterizations. We utilize WRF’s single-column version to verify and validate our proposed modifications to the Mellor-Yamada-Nakanishi-Niino (MYNN) boundary layer parameterization (Nakanishi and Niino, 2004). We explore the implications of our modifications for two-way coupling between WRF and wave models (e.g.,Wavewatch III). The newly implemented parameterization accounting for marine atmospheric boundary layer-wave coupling is then tested in three-dimensional WRF simulations at grid sizes near 1 km. These simulations identify the behavior of simulated winds at the
3. Atmospheric pressure resistive barrier air plasma jet induced bacterial inactivation in aqueous environment
Thiyagarajan, Magesh; Sarani, Abdollah; Gonzales, Xavier
2013-03-01
An atmospheric pressure resistive barrier air plasma jet is designed to inactivate bacteria in aqueous media in direct and indirect exposure modes of treatment. The resistive barrier plasma jet is designed to operate at both dc and standard 50-60 Hz low frequency ac power input and the ambient air at 50% humidity level was used as the operating gas. The voltage-current characteristics of the plasma jet were analyzed and the operating frequency of the discharge was measured to be 20 kHz and the plasma power was measured to be 26 W. The plasma jet rotational temperatures (Trot) are obtained from the optical emission spectra, from the N2C-B(2+) transitions by matching the experimental spectrum results with the Spectra Air (SPECAIR) simulation spectra. The reactive oxygen and nitrogen species were measured using optical emission spectroscopy and gas analyzers, for direct and indirect treatment modes. The nitric oxides (NO) were observed to be the predominant long lived reactive nitrogen species produced by the plasma. Three different bacteria including Staphylococcus aureus (Gram-positive), Escherichia coli (Gram-negative), and Neisseria meningitidis (Gram-negative) were suspended in an aqueous media and treated by the resistive barrier air plasma jet in direct and indirect exposure modes. The results show that a near complete bacterial inactivation was achieved within 120 s for both direct and indirect plasma treatment of S. aureus and E. coli bacteria. Conversely, a partial inactivation of N. meningitidis was observed by 120 s direct plasma exposure and insignificant inactivation was observed for the indirect plasma exposure treatment. Plasma induced shifts in N. meningitidis gene expression was analyzed using pilC gene expression as a representative gene and the results showed a reduction in the expression of the pilC gene compared to untreated samples suggesting that the observed protection against NO may be regulated by other genes.
4. Two-stage energy thermalization mechanism in nanosecond pulse discharges in air and hydrogen-air mixtures
Lanier, Suzanne; Shkurenkov, Ivan; Adamovich, Igor V.; Lempert, Walter R.
2015-04-01
Time-resolved and spatially resolved temperature measurements, by pure rotational picosecond broadband coherent anti-Stokes Raman spectroscopy (CARS), and kinetic modeling calculations are used to study kinetics of energy thermalization in nanosecond pulse discharges in air and hydrogen-air mixtures. The diffuse filament, nanosecond pulse discharge (pulse duration ˜100 ns) is sustained between two spherical electrodes and is operated at a low pulse repetition rate to enable temperature measurements over a wide range of time scales after the discharge pulse. The experimental results demonstrate high accuracy of pure rotational ps CARS for thermometry measurements in highly transient non-equilibrium plasmas. Rotational-translational temperatures are measured for time delays after the pulse ranging from tens of ns to tens of ms, spanning several orders of magnitude of time scales for energy thermalization in non-equilibrium plasmas. In addition, radial temperature distributions across the plasma filament are measured for several time delays after the discharge pulse. Kinetic modeling calculations using a state-specific master equation kinetic model of reacting hydrogen-air plasmas show good agreement with experimental data. The results demonstrate that energy thermalization and temperature rise in these plasmas occur in two clearly defined stages, (i) ‘rapid’ heating, caused by collisional quenching of excited electronic states of N2 molecules by O2, and (ii) ‘slow’ heating, caused primarily by N2 vibrational relaxation by O atoms (in air) and by chemical energy release during partial oxidation of hydrogen (in H2-air). The results have major implications for plasma assisted combustion and plasma flow control.
5. Plasma test on industrial diamond powder in hydrogen and air for fracture strength study
Chary, Rohit Asuri Sudharshana
Diamonds are the most precious material all over the world. Ever since their discovery, the desire for natural diamonds has been great; recently, the demand has steeply increased, leading to scarcity. For example, in 2010, diamonds worth \$50 billion were marketed. This increased demand has led to discovering alternative sources to replace diamonds. The diamond, being the hardest material on earth, could be replaced with no other material except another diamond. Thus, the industrial or synthetic diamond was invented. Because of extreme hardness is one of diamond's properties, diamonds are used in cutting operations. The fracture strength of diamond is one of the crucial factors that determine its life time as a cutting tool. Glow discharge is one of the techniques used for plasma formation. The glow discharge process is conducted in a vacuum chamber by ionizing gas atoms. Ions penetrate into the atomic structure, ejecting a secondary electron. The objective of this study is to determine the change in fracture strength of industrial diamond powder before and after plasma treatment. This study focuses mainly on the change in crystal defects and crushing strength (CS) of industrial diamond powder after the penetration of hydrogen gas, air and hydrogen-air mixture ions into the sample powder. For this study, an industrial diamond powder sample of 100 carats weight, along with its average fracture strength value was received from Engis Corporation, Illinois. The sample was divided into parts, each weighing 10-12 carats. At the University of Nevada, Las Vegas (UNLV), a plasma test was conducted on six sample parts for a total of 16 hours on each part. The three gas types mentioned above were used during plasma tests, with the pressure in vacuum chamber between 200 mTorr and 2 Torr. The plasma test on four sample parts was in the presence of hydrogen-air mixture. The first sample had chamber pressures between 200 mTorr and 400 mTorr. The remaining three samples had chamber
6. The non-equilibrium statistical mechanics of a simple geophysical fluid dynamics model
Verkley, Wim; Severijns, Camiel
2014-05-01
Lorenz [1] has devised a dynamical system that has proved to be very useful as a benchmark system in geophysical fluid dynamics. The system in its simplest form consists of a periodic array of variables that can be associated with an atmospheric field on a latitude circle. The system is driven by a constant forcing, is damped by linear friction and has a simple advection term that causes the model to behave chaotically if the forcing is large enough. Our aim is to predict the statistics of Lorenz' model on the basis of a given average value of its total energy - obtained from a numerical integration - and the assumption of statistical stationarity. Our method is the principle of maximum entropy [2] which in this case reads: the information entropy of the system's probability density function shall be maximal under the constraints of normalization, a given value of the average total energy and statistical stationarity. Statistical stationarity is incorporated approximately by using stationarity constraints', i.e., by requiring that the average first and possibly higher-order time-derivatives of the energy are zero in the maximization of entropy. The analysis [3] reveals that, if the first stationarity constraint is used, the resulting probability density function rather accurately reproduces the statistics of the individual variables. If the second stationarity constraint is used as well, the correlations between the variables are also reproduced quite adequately. The method can be generalized straightforwardly and holds the promise of a viable non-equilibrium statistical mechanics of the forced-dissipative systems of geophysical fluid dynamics. [1] E.N. Lorenz, 1996: Predictability - A problem partly solved, in Proc. Seminar on Predictability (ECMWF, Reading, Berkshire, UK), Vol. 1, pp. 1-18. [2] E.T. Jaynes, 2003: Probability Theory - The Logic of Science (Cambridge University Press, Cambridge). [3] W.T.M. Verkley and C.A. Severijns, 2014: The maximum entropy
7. Experimental Determination of Equilibrium and Non-equilibrium Thermodynamic Propertiesof Natural Porous Media.
Peluso, F.; Arienzo, I.
Experimental investigation of the behavior of porous media is a field of interest of modern non-equilibrium thermodynamics. In the frame of a multi-disciplinary re- search project we are performing in our laboratory experimental tests to measure equilibrium and nonequilibrium thermodynamic properties of natural porous media. Aim of our study is to characterize some stone samples and to verify whether a mass transport due to coupled pressure and temperature gradients (thermo-mechanic) is ap- preciable in this kind of porous medium. We have designed an apparatus that allows to measure the volume flux across a porous sample at various, predefined pressures and temperatures, both in isothermal and non isothermal conditions. A mechanical piston compels a liquid to flow through the sample, previously saturated under vacuum with the same fluid. Knowing the geometrical dimensions of the stone, the volume flux is estimated by measuring the time needed to a known amount of liquid to flow across the sample. Measurements have been performed in isothermal conditions at various temperatures and in non-isothermal conditions. Non-isothermal measurements have been performed both in unsteady and steady-state thermal conditions. Before to be undergone to a measurement cycle, samples are dried and weighted. Then they are sat- urated under vacuum with pure distilled water and weighted once again. By difference between the two measurements, porosity is determined. In all examined samples the volume flux has been found linear with respect to the applied pressure at the various temperatures. The values of volume flux in unsteady thermal conditions are consid- erably higher than the one obtained at the same pressure in isothermal conditions at the higher temperature (T=+45rC). This could be the evidence of a thermo-mechanic effect, pushing the water from hot to cold. Once the steady thermal state is reached, however, this effect disappears. Only measurements performed in unsteady thermal
8. Non-equilibrium thermodynamics theory of econometric source discovery for large data analysis
van Bergem, Rutger; Jenkins, Jeffrey; Benachenhou, Dalila; Szu, Harold
2014-05-01
Almost all consumer and firm transactions are achieved using computers and as a result gives rise to increasingly large amounts of data available for analysts. The gold standard in Economic data manipulation techniques matured during a period of limited data access, and the new Large Data Analysis (LDA) paradigm we all face may quickly obfuscate most tools used by Economists. When coupled with an increased availability of numerous unstructured, multi-modal data sets, the impending 'data tsunami' could have serious detrimental effects for Economic forecasting, analysis, and research in general. Given this reality we propose a decision-aid framework for Augmented-LDA (A-LDA) - a synergistic approach to LDA which combines traditional supervised, rule-based Machine Learning (ML) strategies to iteratively uncover hidden sources in large data, the artificial neural network (ANN) Unsupervised Learning (USL) at the minimum Helmholtz free energy for isothermal dynamic equilibrium strategies, and the Economic intuitions required to handle problems encountered when interpreting large amounts of Financial or Economic data. To make the ANN USL framework applicable to economics we define the temperature, entropy, and energy concepts in Economics from non-equilibrium molecular thermodynamics of Boltzmann viewpoint, as well as defining an information geometry, on which the ANN can operate using USL to reduce information saturation. An exemplar of such a system representation is given for firm industry equilibrium. We demonstrate the traditional ML methodology in the economics context and leverage firm financial data to explore a frontier concept known as behavioral heterogeneity. Behavioral heterogeneity on the firm level can be imagined as a firm's interactions with different types of Economic entities over time. These interactions could impose varying degrees of institutional constraints on a firm's business behavior. We specifically look at behavioral
9. A Novel Technique to Treat Air Leak Following Lobectomy: Intrapleural Infusion of Plasma
PubMed Central
Konstantinou, Froso; Potaris, Konstantinos; Syrigos, Konstantinos N.; Tsipas, Panteleimon; Karagkiouzis, Grigorios; Konstantinou, Marios
2016-01-01
Background Persistent air leak following pulmonary lobectomy can be very difficult to treat and results in prolonged hospitalization. We aimed to evaluate the efficacy of a new method of postoperative air leak management using intrapleurally infused fresh frozen plasma via the chest tube. Material/Methods Between June 2008 and June 2014, we retrospectively reviewed 98 consecutive patients who underwent lobectomy for lung cancer and postoperatively developed persistent air leak treated with intrapleural instillation of fresh frozen plasma. Results The study identified 89 men and 9 women, with a median age of 65.5 years (range 48–77 years), with persistent postoperative air leak. Intrapleural infusion of fresh frozen plasma was successful in stopping air leaks in 90 patients (92%) within 24 hours, and in 96 patients (98%) within 48 hours, following resumption of the procedure. In the remaining 2, air leak ceased at 14 and 19 days. Conclusions Intrapleural infusion of fresh frozen plasma is a safe, inexpensive, and remarkably effective method for treatment of persistent air leak following lobectomy for lung cancer. PMID:27079644
10. Simulated experiment for elimination of air contaminated with odorous chemical agents by microwave plasma burner
SciTech Connect
Hong, Yong Cheol; Shin, Dong Hun; Uhm, Han Sup
2007-10-15
An experimental study on elimination of odorous chemical agent was carried out by making use of a microwave plasma burner, which consists of a microwave plasma torch and a reaction chamber with a fuel injector. Injection of hydrocarbon fuels into a high-temperature microwave torch plasma generates a plasma flame. The plasma flame can eliminate the odorous chemical agent diluted in air or purify the interior air of a large volume in isolated spaces. The specially designed reaction chamber eliminated H{sub 2}S and NH{sub 3} diluted in airflow rate of 5000 lpm (liters per minute), showing {beta} values of 46.52 and 39.69 J/l, respectively.
11. Ignition conditions relaxation for central hot-spot ignition with an ion-electron non-equilibrium model
Fan, Zhengfeng; Liu, Jie; Liu, Bin; Yu, Chengxin; He, X. T.
2016-01-01
Fusion ignition experiments on the National Ignition Facility have demonstrated >5 keV hot spot with ρRh lower than 0.3 g/cm2 [Döppner et al., Phys. Rev. Lett. 115, 055001 (2015)]. We present an ion-electron non-equilibrium model, in which the hot-spot ion temperature is higher than its electron temperature so that the hot-spot nuclear reactions are enhanced while energy leaks are considerably reduced. Theoretical analysis shows that the ignition region would be significantly enlarged in the hot-spot ρR-T space as compared with the commonly used equilibrium model. Simulations show that shocks could be utilized to create and maintain non-equilibrium conditions within the hot spot, and the hot-spot ρR requirement is remarkably reduced for achieving self-heating.
12. Fast tomographic measurements of temperature in an air plasma cutting torch
Hlína, J.; Šonský, J.; Gruber, J.; Cressault, Y.
2016-03-01
Temperatures in an air plasma jet were measured using a tomographic experimental arrangement providing time-resolved scans of plasma optical radiation in the spectral band 559-601 nm from two directions. The acquired data and subsequent processing yielded time-resolved temperature distributions in measurement planes perpendicular to the plasma jet axis with a temporal resolution of 1 μs. The measurement system and evaluation methods afforded detailed information about the influence of high-frequency ripple modulation of the arc current on plasma temperature.
13. Characteristics of a Direct Current-driven plasma jet operated in open air
Li, Xuechen; Di, Cong; Jia, Pengying; Bao, Wenting
2013-09-01
A DC-driven plasma jet has been developed to generate a diffuse plasma plume by blowing argon into the ambient air. The plasma plume, showing a cup shape with a diameter of several centimeters at a higher voltage, is a pulsed discharge despite a DC voltage is applied. The pulse frequency is investigated as a function of the voltage under different gap widths and gas flow rates. Results show that plasma bullets propagate from the hollow needle to the plate electrode by spatially resolved measurement. A supposition about non-electroneutral trail of the streamer is proposed to interpret these experimental phenomena.
14. Characteristics of a Direct Current-driven plasma jet operated in open air
SciTech Connect
Li, Xuechen; Bao, Wenting; Di, Cong; Jia, Pengying
2013-09-30
A DC-driven plasma jet has been developed to generate a diffuse plasma plume by blowing argon into the ambient air. The plasma plume, showing a cup shape with a diameter of several centimeters at a higher voltage, is a pulsed discharge despite a DC voltage is applied. The pulse frequency is investigated as a function of the voltage under different gap widths and gas flow rates. Results show that plasma bullets propagate from the hollow needle to the plate electrode by spatially resolved measurement. A supposition about non-electroneutral trail of the streamer is proposed to interpret these experimental phenomena.
15. Thermodynamic Bethe ansatz for non-equilibrium steady states: exact energy current and fluctuations in integrable QFT
Castro-Alvaredo, Olalla; Chen, Yixiong; Doyon, Benjamin; Hoogeveen, Marianne
2014-03-01
We evaluate the exact energy current and scaled cumulant generating function (related to the large-deviation function) in non-equilibrium steady states with energy flow, in any integrable model of relativistic quantum field theory (IQFT) with diagonal scattering. Our derivations are based on various recent results of Bernard and Doyon. The steady states are built by connecting homogeneously two infinite halves of the system thermalized at different temperatures Tl, Tr, and waiting for a long time. We evaluate the current J(Tl, Tr) using the exact QFT density matrix describing these non-equilibrium steady states and using Zamolodchikov’s method of the thermodynamic Bethe ansatz (TBA). The scaled cumulant generating function is obtained from the extended fluctuation relations which hold in integrable models. We verify our formula in particular by showing that the conformal field theory (CFT) result is obtained in the high-temperature limit. We analyze numerically our non-equilibrium steady-state TBA equations for three models: the sinh-Gordon model, the roaming trajectories model, and the sine-Gordon model at a particular reflectionless point. Based on the numerics, we conjecture that an infinite family of non-equilibrium c-functions, associated with the scaled cumulants, can be defined, which we interpret physically. We study the full scaled distribution function and find that it can be described by a set of independent Poisson processes. Finally, we show that the ‘additivity’ property of the current, which is known to hold in CFT and was proposed to hold more generally, does not hold in general IQFT—that is, J(Tl, Tr) is not of the form f(Tl) - f(Tr).
16. A second perspective on the Amann-Schmiedl-Seifert criterion for non-equilibrium in a three-state system
Jia, Chen; Chen, Yong
2015-05-01
In the work of Amann, Schmiedl and Seifert (2010 J. Chem. Phys. 132 041102), the authors derived a sufficient criterion to identify a non-equilibrium steady state (NESS) in a three-state Markov system based on the coarse-grained information of two-state trajectories. In this paper, we present a mathematical derivation and provide a probabilistic interpretation of the Amann-Schmiedl-Seifert (ASS) criterion. Moreover, the ASS criterion is compared with some other criterions for a NESS.
17. I. Dissociation free energies of drug-receptor systems via non-equilibrium alchemical simulations: a theoretical framework.
PubMed
Procacci, Piero
2016-06-01
In this contribution I critically revise the alchemical reversible approach in the context of the statistical mechanics theory of non-covalent bonding in drug-receptor systems. I show that most of the pitfalls and entanglements for the binding free energy evaluation in computer simulations are rooted in the equilibrium assumption that is implicit in the reversible method. These critical issues can be resolved by using a non-equilibrium variant of the alchemical method in molecular dynamics simulations, relying on the production of many independent trajectories with a continuous dynamical evolution of an externally driven alchemical coordinate, completing the decoupling of the ligand in a matter of a few tens of picoseconds rather than nanoseconds. The absolute binding free energy can be recovered from the annihilation work distributions by applying an unbiased unidirectional free energy estimate, on the assumption that any observed work distribution is given by a mixture of normal distributions, whose components are identical in either direction of the non-equilibrium process, with weights regulated by the Crooks theorem. I finally show that the inherent reliability and accuracy of the unidirectional estimate of the decoupling free energies, based on the production of a few hundreds of non-equilibrium independent sub-nanosecond unrestrained alchemical annihilation processes, is a direct consequence of the funnel-like shape of the free energy surface in molecular recognition. An application of the technique to a real drug-receptor system is presented in the companion paper.
18. Comparison of the Marcus and Pekar partitions in the context of non-equilibrium, polarizable-continuum solvation models
SciTech Connect
You, Zhi-Qiang; Herbert, John M.; Mewes, Jan-Michael; Dreuw, Andreas
2015-11-28
The Marcus and Pekar partitions are common, alternative models to describe the non-equilibrium dielectric polarization response that accompanies instantaneous perturbation of a solute embedded in a dielectric continuum. Examples of such a perturbation include vertical electronic excitation and vertical ionization of a solution-phase molecule. Here, we provide a general derivation of the accompanying polarization response, for a quantum-mechanical solute described within the framework of a polarizable continuum model (PCM) of electrostatic solvation. Although the non-equilibrium free energy is formally equivalent within the two partitions, albeit partitioned differently into “fast” versus “slow” polarization contributions, discretization of the PCM integral equations fails to preserve certain symmetries contained in these equations (except in the case of the conductor-like models or when the solute cavity is spherical), leading to alternative, non-equivalent matrix equations. Unlike the total equilibrium solvation energy, however, which can differ dramatically between different formulations, we demonstrate that the equivalence of the Marcus and Pekar partitions for the non-equilibrium solvation correction is preserved to high accuracy. Differences in vertical excitation and ionization energies are <0.2 eV (and often <0.01 eV), even for systems specifically selected to afford a large polarization response. Numerical results therefore support the interchangeability of the Marcus and Pekar partitions, but also caution against relying too much on the fast PCM charges for interpretive value, as these charges differ greatly between the two partitions, especially in polar solvents.
19. Comparison of the Marcus and Pekar partitions in the context of non-equilibrium, polarizable-continuum solvation models.
PubMed
You, Zhi-Qiang; Mewes, Jan-Michael; Dreuw, Andreas; Herbert, John M
2015-11-28
The Marcus and Pekar partitions are common, alternative models to describe the non-equilibrium dielectric polarization response that accompanies instantaneous perturbation of a solute embedded in a dielectric continuum. Examples of such a perturbation include vertical electronic excitation and vertical ionization of a solution-phase molecule. Here, we provide a general derivation of the accompanying polarization response, for a quantum-mechanical solute described within the framework of a polarizable continuum model (PCM) of electrostatic solvation. Although the non-equilibrium free energy is formally equivalent within the two partitions, albeit partitioned differently into "fast" versus "slow" polarization contributions, discretization of the PCM integral equations fails to preserve certain symmetries contained in these equations (except in the case of the conductor-like models or when the solute cavity is spherical), leading to alternative, non-equivalent matrix equations. Unlike the total equilibrium solvation energy, however, which can differ dramatically between different formulations, we demonstrate that the equivalence of the Marcus and Pekar partitions for the non-equilibrium solvation correction is preserved to high accuracy. Differences in vertical excitation and ionization energies are <0.2 eV (and often <0.01 eV), even for systems specifically selected to afford a large polarization response. Numerical results therefore support the interchangeability of the Marcus and Pekar partitions, but also caution against relying too much on the fast PCM charges for interpretive value, as these charges differ greatly between the two partitions, especially in polar solvents.
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https://forum.bebac.at/forum_entry.php?id=20684&order=time | ## On the contrary, my dear Dr. Watson! [Two-Stage / GS Designs]
Hi ElMaestro,
» I remember having heard EU regulators mention preference for method C out of consideration for the type I error.
What? Where?
» But I can't seem to find a presentation from anyone saying so.
Would surprise me if there is any.
» Do you […] have a link or a presentation by a regulator where this was stated?
Nope. The collaborative work about the type I error was removed from the work plan last year (Paola Coppola’s presentation at BioBridges 2018):
No work plans published this year for both parties due to Brexit. However, there is an unequivocal preference towards methods demonstrating analytically strict control of the TIE.1,2,3 In my experience European regulatory statisticians hate simulation-based methods.
On Wednesday’s workshop I endured a frustrating chat with a statistician of the Austrian agency AGES. Collection of errors and misconceptions:
• Simulation-based methods ‘Type 2’ (e.g., Potvin C) lead to an inflated TIE.
Wrong. Even with the original adjusted α 0.0294 only within n1 12–16 and CV 16–26%. Could easily be counteracted by a more conservative α 0.0282.
• Kieser and Rauch4 showed that 0.0294 is not correct.
Wrong. The authors didn’t show anything (in the sense of a proof) but lamented that 0.0294 is Pocock’s adjusted α for a superiority test (one-sided), wheras for equivalence the correct one is 0.0304. Right, though both are for a group-sequential design with a fixed sample size and one interim at exactly ½N.a That’s not what we have in a TSD with sample size re-estimation in the interim. When you inspect the electronic supplementary material of the paper – or better, perform simulations with a narrower grid – you will find a slight inflation of the TIE. In TSDs the adjustment depends on the ranges of n1 and CV, the fixed GMR, and the target power. Incidentally in Method B 0.0294 turns out to be conservative.b That’s the reason why regulators prefer B over C. For an example where Method C was not accepted see there. If you want to go with Method B, you could use an adjusted α 0.0301. Quoting the GL: “… the choice of how much alpha to spend at the interim analysis is at the company’s discretion.”
The NLYW had a PhD in biostatistics and believed [sic] that 0.0304 is suitable in all settings. Jesus fucking Christ!
• Simulation-based methods are basically to be rejected in principal, since there are exact methods that control the TIE.
Well roared, lion! For 2×2 crossovers only since our posters.1,2 I have strong doubts that – given the rudimentary information – anybody ever successfully used it. The scripts given by Maurer et al.3 are almost useless. Practically the method couldn’t be applied until we implemented it (THX to Ben!) in Power2Stage. In other words, it is wishful thinking that someone could have used the method before April 2018.
An analogous version for repeated confidence intervals in parallel designs doesn’t exist at all. I don’t know anybody working on it. Not trivial for unequal group sizes and/or variances. Reply: “Doesn’t matter because parallel designs are rarely used in BE.” Wake up, girlie!
Was like talking to a brick wall or a conversation with your TV set.
Yesterday I sent a clarification e-mail rant to Thomas Lang (AGES, member of the BSWP). I don’t expect to get a reply. [Edit: One month later. Expectation realized.]
1. König F, Wolfsegger M, Jaki T, Schütz H, Wassmer G. Adaptive two-stage bioequivalence trials with early stopping and sample size re-estimation. 2014. doi:10.13140/RG.2.1.5190.0967.
2. König F, Wolfsegger M, Jaki T, Schütz H, Wassmer G. Adaptive two-stage bioequivalence trials with early stopping and sample size re-estimation. Trials. 2015; 16(Suppl 2);P218. doi:10.1186/1745-6215-16-S2-P218.
3. Maurer W, Jones B, Chen Y. Controlling the type 1 error rate in two-stage sequential designs when testing for average bioequivalence. Stat Med. 2018; 37(10): 1587–1607. doi:10.1002/sim.7614.
4. Kieser M, Rauch G. Two-stage designs for cross-over bioequivalence trials. Stat Med. 2015; 34(16): 2403–16. doi:10.1002/sim.6487.
1. An all too often overlooked detail: If the interim is at <½N (due to dropouts) one has to use an error-spending function (e.g., Lan and DeMets, Jennison and Turnbull) to control the TIE.
2. One mio simulations of a narrow grid (step size 2); TIEmax at n1 12 and CV 24%. Approximations by the shifted central t and the noncentral t, exact by Owen’s Q. Go for a cup of coffee. The exact method is very slow.
library(Power2Stage) method <- "B" alpha <- rep(0.0294, 2) GMR <- 0.95 target <- 0.80 n1 <- 12 # location of the CV <- 0.24 # maximum empiric TIE power <- c("shifted", "nct", "exact") res <- data.frame(method = method, alpha = alpha[1], GMR = GMR, target = sprintf("%.0f%%", 100 * target), power = power) for (j in 1:nrow(res)) { start <- proc.time()[[3]] res$TIE[j] <- power.tsd(method = method, alpha = alpha, n1 = n1, CV = CV, GMR = GMR, targetpower = target, theta0 = 1.25, pmethod = power[j], nsims = 1e6)$pBE res$speed[j] <- proc.time()[[3]] - start cat(sprintf("%7s: %6.2f", power[j], res$speed[j]), "seconds\n") } # patience, please! res$speed <- signif(res$speed / res\$speed[1], 3) print(res, row.names = FALSE) method alpha GMR target power TIE speed B 0.0294 0.95 80% shifted 0.048959 1.00 B 0.0294 0.95 80% nct 0.048762 1.57 B 0.0294 0.95 80% exact 0.048925 41.80
With alpha = rep(0.0301, 2):
method alpha GMR target power TIE speed B 0.0301 0.95 80% shifted 0.050004 1.00 B 0.0301 0.95 80% nct 0.049790 1.57 B 0.0301 0.95 80% exact 0.049786 41.30
Dif-tor heh smusma 🖖
Helmut Schütz
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http://www.msri.org/workshops/114/schedules/670 | Mathematical Sciences Research Institute
Home » Workshop » Schedules » Constructions of special Lagrangian m-folds in $$\C^m$$
Constructions of special Lagrangian m-folds in $$\C^m$$
The Global Theory of Minimal Surfaces (Summer Graduate Program II) June 25, 2001 - July 06, 2001
July 26, 2001 (09:15 AM PDT - 10:45 AM PDT)
Speaker(s): Dominic Joyce (University of Oxford)
Location: MSRI: Simons Auditorium
Video | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.3101975917816162, "perplexity": 5083.640322503026}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2016-30/segments/1469257829970.64/warc/CC-MAIN-20160723071029-00057-ip-10-185-27-174.ec2.internal.warc.gz"} |
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# A rectangular tabletop consists of a piece of laminated wood
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A rectangular tabletop consists of a piece of laminated wood [#permalink]
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06 Oct 2010, 11:19
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A rectangular tabletop consists of a piece of laminated wood bordered by a thin metal strip along its four edges. The surface area of the tabletop is x square feet, and the total length of the strip before it was attached was x feet. If the tabletop is 3 feet wide, what is its approximate length, in feet?
(A) 12
(B) 10
(C) 9
(D) 8
(E) 6
Math Expert
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Posts: 53020
### Show Tags
06 Oct 2010, 11:29
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2
niheil wrote:
A rectangular tabletop consists of a piece of laminated wood bordered by a thin metal strip along its four edges. The surface area of the tabletop is x square feet, and the total length of the strip before it was attached was x feet. If the tabletop is 3 feet wide, what is its approximate length, in feet?
Choices:
(A) 12
(B) 10
(C) 9
(D) 8
(E) 6
(E) 6
Hi, and welcome to Gmat Club. Below is a solution for your problem.
Given: $$area=length*width=x$$, as $$width=3$$ --> $$3l=x$$.
"Wood bordered by a thin metal strip along its four edges" and "the total length of the strip before it was attached was x" means that perimeter of a rectangular tabletop is also equal to $$x$$: $$2(l+w)=2l+6=x$$;
So we have: $$3l=2l+6$$ --> $$l=6$$.
Hope it's clear.
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Joined: 06 Oct 2010
Posts: 29
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06 Oct 2010, 11:49
Thanks Bunuel! You are a genius.
Don't you think that this question can be misinterpreted? I imagined the thin metal strip as having a width that does not equal 0. Unless I am mistaken, that would change the answer. I guess the test-makers wanted me to interpret the word "thin" as meaning that the width of the metal strip was 0. Not fair!
Thanks a bunch for your help, Bunuel.
Intern
Joined: 05 Oct 2010
Posts: 2
### Show Tags
06 Oct 2010, 16:24
1
Hello Guys,
My first post.
In case the metal width is non negligible , lets say its 2 feet.
then
Given: area=length*width=x, as width=3 3L=x
The length of metal strip would be the perimeter of the rectangle + 4 times the width of metal ie length of strip = x= 2(3+L) + (4*2)
Solving for L will give us 14 feet
Please Note the width of the metal strip is multiplied 4 times to get the actual length of metal strip.
Thanks,
Milan
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Joined: 06 Oct 2010
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06 Oct 2010, 16:56
Hey Milan,
Yeah, that's what I thought. If the width of the metal strip was non-negligible, then the answer would be different. I think this question can be misinterpreted.
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Re: A rectangular tabletop consists of a piece of laminated wood [#permalink]
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31 Jan 2014, 19:42
Ambiguous Question. Nowhere explicitly stated that we shouldn't consider the thickness of the thin metal strip.
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Re: A rectangular tabletop consists of a piece of laminated wood [#permalink]
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27 Mar 2015, 03:28
Bunuel wrote:
niheil wrote:
A rectangular tabletop consists of a piece of laminated wood bordered by a thin metal strip along its four edges. The surface area of the tabletop is x square feet, and the total length of the strip before it was attached was x feet. If the tabletop is 3 feet wide, what is its approximate length, in feet?
Choices:
(A) 12
(B) 10
(C) 9
(D) 8
(E) 6
(E) 6
Hi, and welcome to Gmat Club. Below is a solution for your problem.
Given: $$area=length*width=x$$, as $$width=3$$ --> $$3l=x$$.
"Wood bordered by a thin metal strip along its four edges" and "the total length of the strip before it was attached was x" means that perimeter of a rectangular tabletop is also equal to $$x$$: $$2(l+w)=2l+6=x$$;
So we have: $$3l=2l+6$$ --> $$l=6$$.
Hope it's clear.
The Highlighted part: I am unable to visualize/understand, how the length of a strip (given) becomes the perimeter of a table top. If it said, total length of the table top is x then maybe it would make sense.
Math Expert
Joined: 02 Sep 2009
Posts: 53020
Re: A rectangular tabletop consists of a piece of laminated wood [#permalink]
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27 Mar 2015, 03:53
1
earnit wrote:
Bunuel wrote:
niheil wrote:
A rectangular tabletop consists of a piece of laminated wood bordered by a thin metal strip along its four edges. The surface area of the tabletop is x square feet, and the total length of the strip before it was attached was x feet. If the tabletop is 3 feet wide, what is its approximate length, in feet?
Choices:
(A) 12
(B) 10
(C) 9
(D) 8
(E) 6
(E) 6
Hi, and welcome to Gmat Club. Below is a solution for your problem.
Given: $$area=length*width=x$$, as $$width=3$$ --> $$3l=x$$.
"Wood bordered by a thin metal strip along its four edges" and "the total length of the strip before it was attached was x" means that perimeter of a rectangular tabletop is also equal to $$x$$: $$2(l+w)=2l+6=x$$;
So we have: $$3l=2l+6$$ --> $$l=6$$.
Hope it's clear.
The Highlighted part: I am unable to visualize/understand, how the length of a strip (given) becomes the perimeter of a table top. If it said, total length of the table top is x then maybe it would make sense.
We are told that tabletop is surrounded by a thin metal strip along its four edges and the total length of the strip before it was attached was x feet. So, the length of the strip equals to the perimeter of the tabletop.
Does this make sense?
_________________
Manager
Joined: 06 Mar 2014
Posts: 239
Location: India
GMAT Date: 04-30-2015
Re: A rectangular tabletop consists of a piece of laminated wood [#permalink]
### Show Tags
27 Mar 2015, 06:35
[/quote]
The Highlighted part: I am unable to visualize/understand, how the length of a strip (given) becomes the perimeter of a table top. If it said, total length of the table top is x then maybe it would make sense.[/quote]
We are told that tabletop is surrounded by a thin metal strip along its four edges and the total length of the strip before it was attached was x feet. So, the length of the strip equals to the perimeter of the tabletop.
Does this make sense?[/quote]
Yes it does.
Thank you!
Intern
Joined: 15 Nov 2017
Posts: 34
Re: A rectangular tabletop consists of a piece of laminated wood [#permalink]
### Show Tags
17 Jan 2019, 00:50
Hello,
I am having some trouble understanding exactly what the author of the question is asking us to solve. Could someone provide insight into what is being asked? Thank you!
niheil wrote:
A rectangular tabletop consists of a piece of laminated wood bordered by a thin metal strip along its four edges. The surface area of the tabletop is x square feet, and the total length of the strip before it was attached was x feet. If the tabletop is 3 feet wide, what is its approximate length, in feet?
(A) 12
(B) 10
(C) 9
(D) 8
(E) 6
Re: A rectangular tabletop consists of a piece of laminated wood [#permalink] 17 Jan 2019, 00:50
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# A rectangular tabletop consists of a piece of laminated wood
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https://tlovering.wordpress.com/2016/05/12/integral-canonical-models-for-automorphic-vector-bundles-of-abelian-type/ | I’ve uploaded my first paper to the arxiv: http://arxiv.org/pdf/1605.02717v1.pdf
I construct a bunch of integral models for well known objects, mainly building on Kisin’s first integral models paper. Firstly I extend his models for Shimura varieties to models defined over rings like $\mathbb{Z}[1/N]$ (his are over rings more like $\mathbb{Z}_{(p)}$)
Secondly, and much more substantially, I construct integral models for what Milne calls the “Standard Principal Bundle”, which is a gadget that in particular allows one to construct automorphic vector bundles, but also to have a notion of “de Rham sheaves” and (with a little more work: another paper is on the way) (iso)crystals.
A useful vague way to think about such objects is the following. A Shimura variety is a moduli space of Tannakian subcategories of a certain shape (roughly that they look like Rep G) of a category slightly larger than the category of motives, together with a trivialization of the etale cohomology fibre functors (the “level structure”). The level structure is needed because otherwise one gets some kind of Artin stack it’s difficult to work with. The Standard Principal Bundle parameterizes the same thing but also throws in a trivialisation of the de Rham cohomology fibre functor, making it a G-torsor over the Shimura variety.
Of course, there are technical issues with this description, but it gives you a good idea of how the construction should go: essentially I handle the Hodge type case by systematically exploiting the de Rham cohomology of the universal abelian variety. I handle the case where G is a torus by using the theory of Kisin modules and their relation to lattices in de Rham cohomology (to get a uniqueness statement), and the theory of CM motives (to get existence). I then do some group theoretic gymnastics to pass from the Hodge and torus type cases to the general abelian type case.
Please let me know if you find any mistakes, and I hope you enjoy the paper. 🙂 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 2, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9076559543609619, "perplexity": 468.76636207855506}, "config": {"markdown_headings": true, "markdown_code": false, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-17/segments/1524125949036.99/warc/CC-MAIN-20180427041028-20180427061028-00314.warc.gz"} |
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## anonymous one year ago Find x if the average of 20,20,19,13 and x is 16. Delete Cancel Submit
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average = summation of numbers / total items so average is given 16 so, 16= (20+20+19+13+x)/ 5 => 16= (72+x) / 5 multiply both sides by 5, 16 x 5=$\frac{ (72+x)5 }{ 5 }$ 90 = 72+x subtract 72 from both sides, 90-72=72-72+x 18=x so x=18
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thank you!!!
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Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.997927725315094, "perplexity": 11610.71511454049}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2016-44/segments/1476988719273.38/warc/CC-MAIN-20161020183839-00403-ip-10-171-6-4.ec2.internal.warc.gz"} |
https://www.flexiprep.com/NCERT-Exercise-Solutions/Chemistry/Class-11/Ch-7-Equilibrium-Part-28.html | # Chemistry Class 11 NCERT Solutions: Chapter 7 Equilibrium Part 28
Chemistry Class 11 NCERT Solutions Chapter 7 Equilibrium Part 28
Q: 71. What is the maximum concentration of equimolar solutions of ferrous sulphate and sodium sulphide so that when mixed in equal volumes, there is no precipitation of iron sulphide? (For iron sulphide, .
Let the maximum concentration of each solution be x mol/L. After mixing, the volume of the concentrations of each solution will be reduced to half i.e., .
Then,
Also,
M
If the concentrations of both solutions are equal to or less than M, then there will be no precipitation of iron sulphide.
Q: 72. What is the minimum volume of water required to dissolve 1g of calcium sulphate at 298 K? (For calcium sulphate, ).
Let the solubility of be S.
The,
Molecular mass of
Solubility of in gram/L
This means that we need 1L of water to dissolve
Therefore, to dissolve 1g of we require of water
Q: 73. The concentration of sulphide ion in 0.1M HCl solution saturated with hydrogen sulphide is M. If 10 mL of this is added to 5 mL of 0.04 M solution of the following:. in which of these solutions precipitation will take place? Give
Answer: For precipitation to take place, it is required that the calculated ionic product exceeds the value.
Before mixing:
Ionic Product
This ionic product exceeds the of and CdS. Therefore, precipitation will occur in
CdCl2 and ZnCl2 solutions.
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https://tex.stackexchange.com/questions/488892/getting-a-error-in-the-following-code-missing-delimiter-inserted | # Getting a error in the following code “! Missing delimiter (. inserted).”
$$\eta_{TEG}=\frac{P_{elec}}{\dot{\mathrm{m}} C_{p ex}\left(T_{in}-T_{out})\right} \label{eq:tege}$$
• you need a delimiter after \right either \right) or \right. if you want nothing – David Carlisle May 3 '19 at 7:50
• but you do not want \left or \right as there is no need to stretch the delimiters so just use (...) – David Carlisle May 3 '19 at 7:51
You have written
\left(...)\right
but the correct syntax is
\left(...\right)
However, in your particular case such rescaling of brackets is completely unnecessary.
\documentclass{article}
\begin{document}
$$\eta_{\mathrm{TEG}}=\frac{P_{\mathrm{elec}}}{\dot{\mathrm{m}} C_{p\,\mathrm{ex}}\left(T_{\mathrm{in}}-T_{\mathrm{out}}\right)} =\frac{P_{\mathrm{elec}}}{\dot{\mathrm{m}} C_{p\,\mathrm{ex}}(T_{\mathrm{in}}-T_{\mathrm{out}})} \label{eq:tege}$$
\end{document}
Incidentally, I have made most of your subscripts \mathrm, but do not have enough context to know whether this is appropriate for the C_{p ex}. If there really is a space in this subscript, then probably you want a thin space \, before the C too. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 2, "x-ck12": 0, "texerror": 0, "math_score": 0.9533640742301941, "perplexity": 1872.0588235294179}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-05/segments/1579250606269.37/warc/CC-MAIN-20200122012204-20200122041204-00359.warc.gz"} |
http://www.fields.utoronto.ca/programs/scientific/13-14/numtheoryseminar/ | # SCIENTIFIC PROGRAMS AND ACTIVITIES
October 24, 2014
THE FIELDS INSTITUTE FOR RESEARCH IN MATHEMATICAL SCIENCES
Number Theory Seminar 2013-2014 Fields Institute, Stewart Library, Mondays at 3:30 p.m. Organizing Committee: Leo Goldmakher, Jing-Jing Huang
Upcoming Seminars TBA Past Seminars April 7 Damien Roy (University of Ottawa) On Schmidt and Summerer parametric geometry of numbers In a series of recent papers, W.M. Schmidt and L. Summerer develop a remarkable theory of parametric geometry of numbers which enables them to recover many results about simultaneous rational approximation to families of Q-linearly independent real numbers, or about the dual problem of forming small linear integer combinations of such numbers. They recover classical results of Khintchine and Jarnik as well as more recent results by Bugeaud and Laurent. They also find many new results of Diophantine approximation. Their theory provides constraints on the behavior of the successive minima of a natural family of one parameter convex bodies attached to a given n-tuple of real numbers, in terms of this varying parameter. In this talk, we are interested in the converse problem of constructing n-tuples of numbers for which the corresponding successive minima obey given behavior. We will present the general theory of Schmidt and Summerer, mention some applications, and report on recent progress concerning the above problem. Mar. 24 Wentang Kuo (University of Waterloo) On Erd\H{o}s-Pomerance conjecture for rank one Drinfeld modules (tentative abstract) Let $\phi$ be a sgn-normalized rank one Drinfeld $A$-module defined over $\mathcal{O}$, the integral closure of $A$ in the Hilbert class field of $A$. We prove an analogue of a conjecture of Erd\H{o}s and Pomerance for $\varphi$. Given any $0 \neq \alpha \in \mathcal{O}$ and an ideal $\frak{M}$ in $\mathcal{O}$, let $f_{\alpha}\left(\frak{M}\right) = \left\{f \in A \mid \phi_{f}\left(\alpha\right) \equiv 0 \pmod{\frak{M}} \right\}$ be the ideal in $A$. We denote by $\omega\big(f_\alpha\left(\frak{M}\right)\big)$ the number of distinct prime ideal divisors of $f_\alpha\left(\frak{M}\right)$. If $q \neq 2$, we prove that there exists a normal distribution for the quantity $$\frac{\omega\big(f_\alpha\left(\frak{M}\right)\big)-\frac{1}{2} \left(\log\deg\frak{M}\right)^2}{\frac{1}{\sqrt{3}} \left(\log\deg\frak{M}\right)^{3/2}}.$$ This is the jointed work with Yen-Liang Kuan and Wei-Chen Yao Mar. 17 Kevin Hare (University of Waterloo) Base $d$ expansions with digits $0$ to $q-1$ Let $d$ and $q$ be positive integers, and consider representing a positive integer $n$ with base $d$ and digits $0, 1, \cdots, q-1$. If $q < d$, then not all positive integers can be represented. If $q = d$, every positive integer can be represented in exactly one way. If $q > d$, then there may be multiple ways of representing the integer $n$. Let $f_{d,q}(n)$ be the number of representations of $n$ with base $d$ and digits $0, 1, \cdots, q-1$. For example, if $d = 2$ and $q = 7$ we might represent 6 as $(110)_2 = 1 \cdot 2^2 + 1 \cdot 2^1 + 0 \cdot 2^0$ as well as $(102)_2 = 1 \cdot 2^2 + 0 \cdot 2^1 + 2 \cdot 2^0$. In fact, there are six representations in this case $(110)_2, (102)_2, (30)_2, (22)_2, (14)_2$ and $(6)_2$, hence $f_{2,7}(6) = 6$. In this talk we will discuss the asymptotics of $f_{d,q}(n)$ as $n\to \infty$. This depends in a rather strange way on the Generalized Thue-Morse sequence. While many results are computationally/experimentally true, only partial results are known. Mar. 10 Julian Rosen (University of Waterloo) Multiple zeta values and their truncations The multiple zeta values are real numbers generalizing the values of the Riemann zeta function at positive integers. They are known to satisfy certain algebraic relations, but there are many conjectured transcendence results that have proven to be quite difficult. Truncations of the defining series are called multiple harmonic sums. These rational numbers have interesting arithmetic properties, and are viewed as a finite analogue of the multiple zeta values. We will discuss the parallels between the two theories, as well as some recent results concerning multiple harmonic sums. Mar. 3 Yu-Ru Liu (University of Waterloo) Equidistribution of polynomial sequences in function fields We prove a function field analog of Weyl's classical theorem on equidistribution of polynomial sequences. Our result covers the case when the degree of the polynomial is greater than or equal to the characteristic of the field, which is a natural barrier when one tries to apply the Weyl differencing process to function fields. We also discuss applications to Sakozy's theorem in function fields. This is a joint work with Thai Hoang Le. February 10 Yuanlin Li (Brock University) On The Davenport Constant Let G be a finite abelian group. The Davenport constant D(G) of G is defined to be the smallest positive integer d such that every sequence of d elements in G contains a nonempty subsequence with the product of all its elements equal to 1 the identity of G. The problem of finding D(G) was proposed by H. Davenport in 1966, and it was pointed out that D(G) is connected to the algebraic number theory in the following way. Let K be an algebraic number field and G be its class group. Then D(G) is the maximal number of the prime ideals (counting multiplicity) that can occur in the decomposition of an irreducibleinteger in K. In this talk, we will review some known results regarding the Davenport constant of abelian groups and discuss a few methods which can be used to find the exact value of $D(G). Some recent new results will also be presented. February 3 Stanley Xiao (University of Waterloo) Powerfree values of polynomials In this talk I will give an overview of the progress made on the power-free values of polynomial problem. In particular, I intend to discuss the determinant method of Heath-Brown and Salberger, which so far is the most promising technique on this problem. January 27 Jing-Jing Huang (University of Toronto) Rational points near manifold and Diophantine approximation We will discuss the two topics mentioned in the title. December 2 Monday Lluis Vena (University of Toronto) The removal lemma for homomorphisms in abelian groups The triangle removal lemma states that if a graph has a subcubic number of triangles, then removing a subquadratic number of edges suffices to make G free of triangles. One of its most famous applications is a simple proof of Roth's theorem, which asserts that any subset of the integers with positive upper density contains a 3-term arithmetic progression. In 2005, Green showed an analogous result for linear equations in finite abelian groups, the so-called removal lemma for groups. In this talk, we will discuss a combinatorial proof of Green's result, as well as a generalization to homomorphism systems in finite abelian groups. In particular, our results imply a multidimensional version of Szemeredi's theorem. November 25 Jonathan Bober (University of Bristol) Conditionally bounding analytic ranks of elliptic curves I'll describe how to use the explicit formula for the L-function of an elliptic curve to compute upper bounds for the analytic rank, assuming GRH. This method works particularly well for elliptic curves of large rank and (relatively) small conductor, and can be used to compute exact upper bounds for the curves of largest known rank, assuming BSD and GRH. November 18 Kevin McGown (Ursinus College) Euclidean Number Fields and Ergodic Theory When does a number field possess a Euclidean algorithm? We will discuss how generalizations of this question lead us to studying the S-Euclidean minimum of an ideal class, which is a real number attached to some arithmetic data. Generalizing a result of Cerri, we show that this number is rational under certain conditions. We also give some corollaries and discuss the relationship with Lenstra's notion of a norm-Euclidean ideal class and the conjecture of Barnes and Swinnerton-Dyer on quadratic forms. The proof involves using techniques of Berend from ergodic theory and topological dynamics on the appropriate compact group. November 11 No seminar October 28 Chantal David (Concordia University) One-level density for zeroes in famlies of elliptic curves Using the ratios conjectures as introduced by Conrey, Farmer and Zirnbauer, we obtain closed formulas for the one-level density for some families of L-functions attached to elliptic curves, and we can then determine the underlying symmetry types of the families. The one-level density for some of those families was studied in the past for test functions with Fourier transforms of small support, but since the Fourier transforms of the three orthogonal distributions (O, SO(even) and SO(odd)) are undistinguishable for small support, it was not possible to identify the distribution with those techniques. This can be done with the ratios conjectures. The results confirm the conjectures of Katz and Sarnak, and shed more light on the phenomenon of "independent" and "non-independent" zeroes, and the repulsion phenomenon. This is joint work with Duc Khiem Huynh and James Parks. We also present some work in progress in collaboration with Sandro Bettin where we obtain general formulas for the one-level density of one-parameter families of elliptic curves in term of the rank over Q(t) and the average root number. October 14 No seminar (Reading Week) October 7 4:30-5:30 **please note time change for this week only Alex Iosevich, University of Rochester Group actions and Erdos type problems in vector spaces over finite fields We shall use group invariances to study the distribution of simplexes in vector spaces over finite fields. It turns out that the most convenient way to study repeated simplexes is via appropriate norms of the natural "measure" on the set$E-gE$, where$E$is a subset of the${\Bbb F}_q^d$,$d \ge 2$, and$g$is an element of the orthogonal group$O_d({\Bbb F}_q)\$. September 30 No seminar (Fields Medal Symposium) September 23 Leo Goldmakher (University of Toronto) On the least quadratic nonresidue I will discuss the relationship between bounds on long character sums and bounds on the least quadratic nonresidue. In particular, I will show how small savings on one leads to massive savings in the other. This is joint work with Jonathan Bober. September 16 Giorgis Petridis, University of Rochester Higher sumsets with different summands | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8633465766906738, "perplexity": 315.02160290270876}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-42/segments/1414119646519.4/warc/CC-MAIN-20141024030046-00113-ip-10-16-133-185.ec2.internal.warc.gz"} |
https://worldwidescience.org/topicpages/b/beta+gamma+contamination.html | #### Sample records for beta gamma contamination
1. Vitrification of transuranic and beta-gamma contaminated solid wastes
International Nuclear Information System (INIS)
Dukes, M.D.
1980-06-01
Vitrification of solid transuranic contaminated (TRU) wastes alone and with high-level liquid wastes (HLLW) was studied. Homogeneous glasses containing 20 to 30 wt % ash were made by using glass frits previously developed at the Savannah River Plant and Pacific Northwest Laboratories. If the ash is vitrified along with the HLLW, 1.0 wt % as can be added to the waste forms without affecting their quality. This loading of ash is well above the loading required by the relative amounts of HLLW and TRU ash that will be processed at the Savannah River Plant. Vitrification of TRU-contaminated electropolishing sludges and high efficiency particular air filter materials along with HLLW would require an increase in the quantity of glass to be produced. However, if these TRU-contaminated solids were vitrified with the HLLW, the addition of low-level beta-gamma contaminated ash would require no further increase in glass production
2. Beta-gamma contaminated solid waste incinerator facility
International Nuclear Information System (INIS)
Hootman, H.E.
1979-10-01
This technical data summary outlines a reference process to provide a 2-stage, 400 lb/hour incinerator to reduce the storage volume of combustible process waste contaminated with low-level beta-gamma emitters in response to DOE Manual 0511. This waste, amounting to more than 200,000 ft 3 per year, is presently buried in trenches in the burial ground. The anticipated storage volume reduction from incineration will be a factor of 20. The incinerator will also dispose of 150,000 gallons of degraded solvent from the chemical separations areas and 5000 gallons per year of miscellaneous nonradioactive solvents which are presently being drummed for storage
3. Decontamination Experiments on Intact Pig Skin Contaminated with Beta-Gamma- Emitting Nuclides
Energy Technology Data Exchange (ETDEWEB)
Edvardsson, K A; Hagsgaard, S [AB Atomenergi, Nykoeping (Sweden); Swensson, A [Dept. of Occupational Medicine, Karolinska Sjukhuset, Stockholm (Sweden)
1966-11-15
A number of decontamination experiments have been performed on intact pig skin. In most of the experiments NaI-131 in water solution has been utilized because this nuclide is widely used within the Studsvik research establishment, is easy to detect and relatively harmless, and is practical to use in these experiments. Among the {beta} {gamma}-nuclides studied 1-131 has furthermore proved to be the one most difficult to remove from the skin. The following conclusions and recommendations regarding the decontamination of skin are therefore valid primarily for iodine in the form of Nal, but are probably also applicable to many other {beta} {gamma}-nuclides. a) A prolonged interval between contamination and decontamination has a negative effect on the result of the decontamination. Therefore start decontamination as soon as possible after the contamination. b) Soap and water has proved to be the most suitable decontamination agent. A number of other agents have appeared to be harmful to the skin. Therefore, first of all use only soap and water in connection with gentle rubbing. c) No clear connection between the temperature of the water for washing and the result of the decontamination has been demonstrated. d) Skin not degreased before the contamination seems to be somewhat easier to decontaminate than degreased skin, particularly if the activity has been on the skin for a long time. Therefore do not remove the sebum of the skin when engaged on radioactive work involving contamination risks. e) Irrigation of the contaminated surface with a solution containing the corresponding inactive ions or ordinary water in large quantities may considerably decrease the skin contamination. f) In radioactive work of long duration involving high risks of contamination prophylactic measures in the form of a protective substance ('invisible glove'), type Kerodex, may make decontamination easier.
4. Beta, gamma contamination analysis of thermo luminescence dosimeter cassettes using Geiger Muller counting set up and gamma spectrometry techniques
International Nuclear Information System (INIS)
Prasad, S.K.; Sudheer, T.S.; Sahoo, L.; Vinayagam, Bhakti; Kamble, Mahesh; Khuspe, R.R.; Anilkumar, Rekha; Verma, K.K.
2009-01-01
Β-γ contamination cheek up of TLD cassettes were carried out and the isotopes found were 137 Cs, 106 Ru, 60 Co, 64 Cu, 144 Ce and 95 Nb with activity per square cm varying from 0.05-4.70 Bq/cm 2 with median value 1.3. The assessed dose in TLD was in the range of 2.10 mSv to 22.05 mSv for beta, 0.05 mSv to 5.25 mSv for gamma. The beta doses have median value of 6.19 mSv. This contamination may be due to active water contamination on TLD's of personnel working for irradiated fuel handling or work in fuel rod (under water) storage area. This gives a method to estimate skin exposure of personnel due to skin contamination during work. Chances of getting TLD's contaminated due to various reasons were studied. Contamination was found maximum inside the cassette box having area 16 cm 2 . In case of plastic pouch of TLD disc contamination was detected in three cases. Contamination level on TLD cassettes using GM counter was found in the range of 0.30-3.6 Bq/cm 2 for cassettes. By opening the window of the surveymeter contamination and field of these cassettes in closed condition were found to increase by 20% due to the measurement of beta dose. With the same condition contamination of TLD cassette in open condition was found five times more. This is due to the a-contamination which is five times more than a contamination, The most prominent isotope 137 Cs in common chemical forms are soluble in water and if inhaled or ingested are rapidly and completely absorbed in the lungs and across the gastrointestinal tract. Thus a skin contamination of most prominent isotope 137 Cs can lead to intake in addition to skin dose. Fading studies of contamination of TLD cassettes were carried out. It was found negligible after counting with GM counting set up after a period of 3 months. But one of the TLD cassettes was showing an 80% reduction of contamination after 3 months with GM counting set up, the contaminants being 141 Ce, 103 Ru and 95 Nb. The gamma peaks in the external exposure
DEFF Research Database (Denmark)
Løvborg, Leif; Gaffney, C. F.; Clark, P. A.
1985-01-01
Experimental and/or theoretical estimates are presented concerning, (i) attenuation within the sample of beta and gamma radiation from the soil, (ii) the gamma dose within the sample due to its own radioactivity, and (iii) the soil gamma dose in the proximity of boundaries between regions...... of differing radioactivity. It is confirmed that removal of the outer 2 mm of sample is adequate to remove influence from soil beta dose and estimates are made of the error introduced by non-removal. Other evaluations include variation of the soil gamma dose near the ground surface and it appears...... that the present practice of avoiding samples above a depth of 0.3 m may be over-cautious...
6. Management of defense beta-gamma contaminated solid low-level wastes
International Nuclear Information System (INIS)
Sease, J.D.
1983-01-01
In DOE defense operations, approx. 70,000 m 3 of beta-gamma low-level radioactive waste are disposed of annually by shallow land burial operations at six primary sites. Waste generated at other DOE sites are transported on public roads to the primary sites for disposal. In the practice of low-level waste (LLW) disposal in the US, the site hydrology and geology are the primary barriers to radioactive migration. To date, little emphasis has been placed on waste form improvements or engineered site modifications to reduce migration potential. Compaction is the most common treatment step employed. The performance of ground disposal of radioactive waste in this country, in spite of many practices that we would consider unacceptable in today's light, has resulted in very little migration of radioactivity outside site boundaries. Most problems with previously used burial grounds have been from subsidence at the arid sites and subsidence and groundwater contact at the humid sites. The radionuclides that have shown the most significant migration are tritium, 90 Sr, and 99 Tc. The unit cost for disposal operations at a given DOE site is dependent on many variables, but the annual volume to be disposed is probably the major factor. The average cost for current DOE burial operation is approximately $170/m 3 . 23 figures 7. Simultaneous beta and gamma spectroscopy Science.gov (United States) Farsoni, Abdollah T.; Hamby, David M. 2010-03-23 A phoswich radiation detector for simultaneous spectroscopy of beta rays and gamma rays includes three scintillators with different decay time characteristics. Two of the three scintillators are used for beta detection and the third scintillator is used for gamma detection. A pulse induced by an interaction of radiation with the detector is digitally analyzed to classify the type of event as beta, gamma, or unknown. A pulse is classified as a beta event if the pulse originated from just the first scintillator alone or from just the first and the second scintillator. A pulse from just the third scintillator is recorded as gamma event. Other pulses are rejected as unknown events. 8. Decontamination Experiments on Intact Pig Skin Contaminated with Beta-Gamma- Emitting Nuclides International Nuclear Information System (INIS) Edvardsson, K.A.; Hagsgaard, S.; Swensson, A. 1966-11-01 A number of decontamination experiments have been performed on intact pig skin. In most of the experiments NaI-131 in water solution has been utilized because this nuclide is widely used within the Studsvik research establishment, is easy to detect and relatively harmless, and is practical to use in these experiments. Among the β γ-nuclides studied 1-131 has furthermore proved to be the one most difficult to remove from the skin. The following conclusions and recommendations regarding the decontamination of skin are therefore valid primarily for iodine in the form of Nal, but are probably also applicable to many other β γ-nuclides. a) A prolonged interval between contamination and decontamination has a negative effect on the result of the decontamination. Therefore start decontamination as soon as possible after the contamination. b) Soap and water has proved to be the most suitable decontamination agent. A number of other agents have appeared to be harmful to the skin. Therefore, first of all use only soap and water in connection with gentle rubbing. c) No clear connection between the temperature of the water for washing and the result of the decontamination has been demonstrated. d) Skin not degreased before the contamination seems to be somewhat easier to decontaminate than degreased skin, particularly if the activity has been on the skin for a long time. Therefore do not remove the sebum of the skin when engaged on radioactive work involving contamination risks. e) Irrigation of the contaminated surface with a solution containing the corresponding inactive ions or ordinary water in large quantities may considerably decrease the skin contamination. f) In radioactive work of long duration involving high risks of contamination prophylactic measures in the form of a protective substance ('invisible glove'), type Kerodex, may make decontamination easier 9. {beta} {gamma} porch detector; Detecteur portique {beta} {gamma} Energy Technology Data Exchange (ETDEWEB) Roulet, R [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires 1963-07-01 This device is to be placed at the outside of reactors, hot laboratories and others where radioactive products are treated; it is intended to give the alarm when someone, passing through the porch is greatly contaminated, or carries, without his knowing, a radioactive substance. Being to be used in places where there might be an important ground noise, this device is provided with an automatic offset of this noise; an adjusting system of sensitivity allows to obtain a 15 {mu}Ci in {gamma} and 10 {mu}Ci in {beta} radioactive source, passing through the porch at the normal speed at which man is walking. A battery, set in buffer, allows working of the device, even when current is off. (author) [French] Cet appareil est destine a etre place a la sortie des reacteurs, laboratoires chauds ou autres laboratoires travaillant sur des produits radioactifs; son but est de donner une alarme lorsque quelqu'un, passant sous le portique, presente une forte contamination, ou surtout transporte par inadvertance un corps radioactif. Cet appareil devant etre utilise dans les lieux ou peut regner un bruit de fond important, possede une compensation automatique de ce bruit de fond; un reglage de la sensibilite permet d'obtenir au mieux un declenchement pour une source. de 15 {mu}Ci en {gamma} et 10 {mu}Ci en {beta} passant sous le portique a la vitesse normale d'un homme qui marche. Une batterie montee en tampon permet a l'appareil de fonctionner meme en cas de coupure de courant. (auteur) 10. A {beta} - {gamma} coincidence; Metodo de coincidencias {beta} - {gamma} Energy Technology Data Exchange (ETDEWEB) Agullo, F 1960-07-01 A {beta} - {gamma} coincidence method for absolute counting is given. The fundamental principles are revised and the experimental part is detailed. The results from {sup 1}98 Au irradiated in the JEN 1 Swimming pool reactor are given. The maximal accuracy is 1 per cent. (Author) 11 refs. 11. The gamma contamination food factor International Nuclear Information System (INIS) Kukoc, A.H.; Anicin, I.V.; Adzic, P.R. 1992-01-01 We suggest that radioactive food contamination, as determined solely by a quantitative gamma-ray spectroscopic measurement, may, apart from the total activity per unit mass, be for quick reference conveniently characterized by another single figure which we call the ''Gamma Contamination Food Factor'' (GCFF). This factor may be defined as the ratio of the total specific activity of gamma-ray-emitting radionuclides in the food sample (except that of 40 K) to the specific activity of 40 K either in the sample itself or in an ''average man''. We discuss briefly the meaning and advantages of these definitions. (author) 12. Beta/gamma test problems for ITS International Nuclear Information System (INIS) Mei, G.T. 1993-01-01 The Integrated Tiger Series of Coupled Electron/Photon Monte Carlo Transport Codes (ITS 3.0, PC Version) was used at Oak Ridge National Laboratory (ORNL) to compare with and extend the experimental findings of the beta/gamma response of selected health physics instruments. In order to assure that ITS gives correct results, several beta/gamma problems have been tested. ITS was used to simulate these problems numerically, and results for each were compared to the problem's experimental or analytical results. ITS successfully predicted the experimental or analytical results of all tested problems within the statistical uncertainty inherent in the Monte Carlo method 13. Monitor for alpha beta contamination of hands; Moniteur de contamination alpha beta des mains Energy Technology Data Exchange (ETDEWEB) Guitton, J 1958-07-01 The following specifications of hands alpha beta contamination monitor are presented: the position of the hands, the detection and separation of alpha and beta, the information processing, the programming, the results presentation and general characteristics. (A.L.B.) 14. Low level GAMMA0 spectrometry by beta-gamma coincidence International Nuclear Information System (INIS) Grigorescu, E.L.; Luca, A.; Razdolescu, A.C.; Ivan, C. 1999-01-01 Low level gamma spectrometry has a wide application, especially in environmental monitoring. Two variants, based on a beta-gamma coincidence technique, were studied. The equipment was composed of a beta detector and a Ge(Li) gamma detector (6% - relative efficiency), with the associated electronics. The gamma rays are recorded by the multichannel analyzer (4096 channels) only if the associated beta particles, which precede the gamma transitions, are registered in coincidence. Two types of beta detectors were used: plastic and liquid scintillators. In both cases, an external lead shield of 5 cm thick was used. The integral gamma background (50-1700 KeV) was reduced about 85 and 50 times, respectively. The corresponding MDA (Minimum Detectable Activity) values decreased about 1.5 and (3-7) times, respectively. The 2π sr plastic beta detector was placed on top the Ge(Li). The sample was inserted between the two detectors. The measurement time was 10 4 s. A 4π sr detector, built of the same material, was also studied, but it proved to be less advantageous because the background was reduced only 16 times; for a MDA reduction similar with that of the 2π sr variant, a longer measurement was needed (3.10 4 s). The other type of beta detector used, was a liquid scintillator. The dissolving of the samples in scintillator ensures a 4π sr measurement geometry. The vials with scintillator (10 ml volume) were placed on top the Ge(Li) and visualised by the photocathode of a phototube. This setup was surrounded by an enclosure which prevent the light penetration. The measurement time was 10 4 s. The only difficulty encountered in this low level measurement method is the accurate determination of the beta efficiency. A limitation is the possibility to measure only small mass samples. These variants are more simple and cheaper than others, previously studied. The advantage of the method is obvious when, instead of low MDA values, shorter measurement times are preferred. The 15. Alpha-beta-gamma spectrometer as an aid in directing decontamination of soils International Nuclear Information System (INIS) Berger, C.D. 1981-01-01 This technique permits rapid assessment of alpha-beta-gamma-emitter contamination in soils at sufficiently low concentrations to direct field operations. Of particular importance is its applicability during initial decommissioning and decontamination surveys when characterization of alpha and beta contamination in the presence of a high gamma background is necessary. This system has not yet been made portable for in-situ use, but it is expected that results willbe favorable when operated as a field instrument, resulting in simplified standard decontamination operation 16. Microscopic beta and gamma data for decay-heat needs International Nuclear Information System (INIS) Dickens, J.K. 1983-01-01 Microscopic beta and gamma data for decay-heat needs are defined as absolute-intensity spectral distributions of beta and gamma rays following radioactive decay of radionuclides created by, or following, the fission process. Four well-known evaluated data files, namely the US ENDF/B-V, the UK UKFPDD-2, the French BDN (for fission products), and the Japanese JNDC Nuclear Data Library, are reviewed. Comments regarding the analyses of experimental data (particularly gamma-ray data) are given; the need for complete beta-ray spectral measurements is emphasized. Suggestions on goals for near-term future experimental measurements are presented. 34 references 17. Maternal plasma concentrations of beta-lipotrophin, beta-endorphin and gamma-lipotrophin throughout pregnancy. Science.gov (United States) Browning, A J; Butt, W R; Lynch, S S; Shakespear, R A 1983-12-01 Plasma beta-LPH, beta-EP and gamma-LPH concentrations were measured by radioimmunoassay in 10 pregnant women from 12 weeks gestation until term and in nine women in the early follicular phase of the cycle. There was a progressive and significant rise in the concentration of all three peptides throughout pregnancy and by 32 weeks the concentrations of beta-LPH and beta-EP were greater than the corresponding concentrations in the follicular phase: gamma-LPH was greater than in the follicular phase by the end of pregnancy in those women who were delivered after 40 weeks. The ratio of beta-LPH to gamma-LPH did not change significantly throughout pregnancy, but there was a progressive fall in the beta-LPH/beta-EP ratio. The possible presence of a 'big LPH' to explain this finding is discussed. 18. Gamma ampersand beta-gamma storm water monitor operability International Nuclear Information System (INIS) Tshiskiku, E.M. 1993-01-01 High Level Waste (HLW) facilities have nine storm water monitors that monitor storm water run off from different process areas for Cesium 137, a Gamma emitter. F - Area has three monitors: 907-2F, 907-3F and 907-4F while H - Area has six monitors: 907-2H, 907-3H, 907-4H, 907-5H, 907-6H and 907-7H (See attachments number-sign 1, number-sign 2 and number-sign 3 for location). In addition to monitoring for Cesium, 907-6H and 907-7H monitor for Strontium-90, a Beta emitter. Each monitor is associated with one of the following diversion gate encasements 907-1H, 241-15H, 241-51H, 907-1F or 241-23F. Normal flow of storm water from these diversion gate encasements is to the Four Mile Creek. When a storm water monitor detects radioactivity at a level exceeding the Four Mile Creek discharge limit, the monitor causes repositioning of the associated diversion gate to discharge to the H - Area retention basin 281-8H or the F - Area retention basin 281-8F. In response to recent OSR interpretation of storm water monitor calibration requirements, this report is provided to document operability and accuracy of radiation detection 19. beta. and. gamma. -comparative dose estimates on Enewetak Atoll Energy Technology Data Exchange (ETDEWEB) Crase, K.W.; Gudiksen, P.H.; Robison, W.L. (California Univ., Livermore (USA). Lawrence Livermore National Lab.) 1982-05-01 Enewetak Atoll in the Pacific is used for atmospheric testing of U.S. nuclear weapons. Beta dose and ..gamma..-ray exposure measurements were made on two islands of the Enewetak Atoll during July-August 1976 to determine the ..beta.. and low energy ..gamma..-contribution to the total external radiation doses to the returning Marshallese. Measurements were made at numerous locations with thermoluminescent dosimeters (TLD), pressurized ionization chambers, portable NaI detectors, and thin-window pancake GM probes. Results of the TLD measurements with and without a ..beta..-attenuator indicate that approx. 29% of the total dose rate at 1 m in air is due to ..beta..- or low energy ..gamma..-contribution. The contribution at any particular site, however, is reduced by vegetation. Integral 30-yr external shallow dose estimates for future inhabitants were made and compared with external dose estimates of a previous large scale radiological survey. Integral 30-yr shallow external dose estimates are 25-50% higher than whole body estimates. Due to the low penetrating ability of the ..beta..'s or low energy ..gamma..'s, however, several remedial actions can be taken to reduce the shallow dose contribution to the total external dose. 20. beta- and gamma-Comparative dose estimates on Eniwetok Atoll Energy Technology Data Exchange (ETDEWEB) Crase, K.W.; Gudiksen, P.H.; Robison, W.L. 1982-05-01 Eniwetok Atoll is one of the Pacific atolls used for atmospheric testing of U.S. nuclear weapons. Beta dose and gamma-ray exposure measurements were made on two islands of the Eniwetok Atoll during July-August 1976 to determine the beta and low energy gamma-contribution to the total external radiation doses to the returning Marshallese. Measurements were made at numerous locations with thermoluminescent dosimeters (TLD), pressurized ionization chambers, portable NaI detectors, and thin-window pancake GM probes. Results of the TLD measurements with and without a beta-attenuator indicate that approx. 29% of the total dose rate at 1 m in air is due to beta- or low energy gamma-contribution. The contribution at any particular site, however, is somewhat dependent on ground cover, since a minimal amount of vegetation will reduce it significantly from that over bare soil, but thick stands of vegetation have little effect on any further reductions. Integral 30-yr external shallow dose estimates for future inhabitants were made and compared with external dose estimates of a previous large scale radiological survey (En73). Integral 30-yr shallow external dose estimates are 25-50% higher than whole body estimates. Due to the low penetrating ability of the beta's or low energy gamma's, however, several remedial actions can be taken to reduce the shallow dose contribution to the total external dose. 1. Determination of beta and gamma radioactivity on the coal International Nuclear Information System (INIS) Suhardi; Mulyono; Sutanto WW; Rosidi 2013-01-01 Radioactivity in coal, botton ash and fly ash. This determination was carried out to know each the radioactivity of β gross, γ gross on the coal, botton ash and fly ash, which accommodation of environment data the present in PLTU Paiton Probolinggo. Samples taken preparation and analysis based on the procedures of environmental radioactivity analysis. The radioactivity on the PLTU Paiton Probolinggo detected by beta gross Spectrometer with Geiger Muller (GM) and gamma Spectrometer with Ge(Li) detector. The result indicates that radioactivity concentration of beta and gamma gross are (95,57-308,26) Bq/kg and (1,374 - 31,677) Bq/kg respectively. (author) 2. Calculation of reasonable exemption levels for surface contamination by measuring overall gamma ray International Nuclear Information System (INIS) Ogino, Haruyuki; Hattori, Takatoshi 2008-01-01 The present regulation on surface contamination [Bq/cm 2 ] is determined from a simple radiological model for the most hazardous radionuclides (Pu-239 for alpha emitters and Sr-90 for beta emitters) and its extremely conservative model is applied for all other alpha and beta emitters. In this study, reasonable exemption levels for surface contamination are calculated for each radionuclide by adopting an original radiological dose evaluation method for surface contamination that can be applied in radiation safety, transport safety and waste safety. Furthermore, a new concept of judging the exemption by estimating the overall contamination [Bq] on the objects from the measurement of gamma ray has been designed and a reasonable value was derived. We conclude that the overall exemption levels obtained by gamma ray measurement can be one order smaller than those obtained by the conventional method for some radionuclides, such as Mn-54, Co-60, Nb-94, Cs-134, Cs-137, Eu-152 and Eu-154. (author) 3. Y-formalism and curved {beta}-{gamma} systems Energy Technology Data Exchange (ETDEWEB) Grassi, Pietro Antonio [DISTA, Universita del Piemonte Orientale, via Bellini 25/g, 15100 Alessandria (Italy); INFN - Sezione di Torino (Italy)], E-mail: antonio.pietro.grassi@cern.ch; Oda, Ichiro [Department of Physics, Faculty of Science, University of the Ryukyus, Nishihara, Okinawa 903-0213 (Japan); Tonin, Mario [Dipartimento di Fisica, Universita degli Studi di Padova, INFN, Sezionedi Padova, Via F. Marzolo 8, 35131 Padova (Italy) 2009-01-01 We adopt the Y-formalism to study {beta}-{gamma} systems on hypersurfaces. We compute the operator product expansions of gauge-invariant currents and we discuss some applications of the Y-formalism to model on Calabi-Yau spaces. 4. Evaluation of beta-decay III. The complex gamma function International Nuclear Information System (INIS) Wilkinson, D.H. 1993-05-01 Two real, analytical, approximations for the square of the modulus of the complex gamma function as it appears in F(Z, W), the Fermi function for beta-decay, are evaluated; an accuracy bettering 10 -4 % can easily be achieved for all electron energies throughout the periodic table. (author). 3 refs., 1 tab., 7 figs 5. Top-Down Beta Enhances Bottom-Up Gamma. Science.gov (United States) Richter, Craig G; Thompson, William H; Bosman, Conrado A; Fries, Pascal 2017-07-12 Several recent studies have demonstrated that the bottom-up signaling of a visual stimulus is subserved by interareal gamma-band synchronization, whereas top-down influences are mediated by alpha-beta band synchronization. These processes may implement top-down control of stimulus processing if top-down and bottom-up mediating rhythms are coupled via cross-frequency interaction. To test this possibility, we investigated Granger-causal influences among awake macaque primary visual area V1, higher visual area V4, and parietal control area 7a during attentional task performance. Top-down 7a-to-V1 beta-band influences enhanced visually driven V1-to-V4 gamma-band influences. This enhancement was spatially specific and largest when beta-band activity preceded gamma-band activity by ∼0.1 s, suggesting a causal effect of top-down processes on bottom-up processes. We propose that this cross-frequency interaction mechanistically subserves the attentional control of stimulus selection. SIGNIFICANCE STATEMENT Contemporary research indicates that the alpha-beta frequency band underlies top-down control, whereas the gamma-band mediates bottom-up stimulus processing. This arrangement inspires an attractive hypothesis, which posits that top-down beta-band influences directly modulate bottom-up gamma band influences via cross-frequency interaction. We evaluate this hypothesis determining that beta-band top-down influences from parietal area 7a to visual area V1 are correlated with bottom-up gamma frequency influences from V1 to area V4, in a spatially specific manner, and that this correlation is maximal when top-down activity precedes bottom-up activity. These results show that for top-down processes such as spatial attention, elevated top-down beta-band influences directly enhance feedforward stimulus-induced gamma-band processing, leading to enhancement of the selected stimulus. Copyright © 2017 Richter, Thompson et al. 6. Gamma and beta logging of underground sewer and process lines International Nuclear Information System (INIS) Rangel, M.J.; Martz, D.E.; Langner, G.H. Jr. 1989-11-01 The GammaSnake can be useful for locating uranium mill tailings used as backfill for sewer lines or storm drains where the lines can be readily accessed from a cleanout access port or other opening. The time required to determine if contamination is present using the GammaSnake method is considerably less than when using the delta gamma or drilling methods. There is, also, less potential hazard to the equipment operators when using the GammaSnake method. The GammaSnake method is generally limited to a distance of 100 feet or less. Used with the MAC-51B line locator, the GammaSnake method can provide useful information without extensive drilling or surveying. 7 figs., 2 tabs 7. Experimentation with a prototype incinerator for beta-gamma waste International Nuclear Information System (INIS) Farber, M.G.; Lewandowski, K.E.; Becker, G.W. 1982-01-01 A test facility for the incineration of suspect and low-level beta-gamma waste has been built and operated at the Savannah River Laboratory. The processing steps include waste feeding, incineration, ash residue packaging, and off-gas cleanup. Demonstration of the full-scale (180 kg/hr) facility with nonradioactive, simulated waste is currently in progress. At the present time, over nine metric tons of material including rubber, polyethylene, and cellulose have been incinerated during three burning campaigns. A comprehensive test program of solid and liquid waste incineration is being implemented. The data from the research program is providing the technical basis for a phase of testing with low-level beta-gamma waste generated at the Savannah River Plant 8. PC based alpha, beta and gamma counting system International Nuclear Information System (INIS) Bhattacharya, S.; Gopalakrishnan, K.R.; Bairi, B.R. 1992-01-01 In the field of radiation protection and safety a large number of samples have to be assayed for estimation of their radioactivity at various stages in nuclear fuel. A PC based alpha, beta and gamma counting system has been designed for the above application. The system is fully automatic and requires minimum of operator intervention. The main units in the system are detector and pulse processing electronics, sample changer and assembly and IBM PC interface and supporting software. The main function of interface is to control the sample changer which is basically loading and unloading of sample, data acquisition and further processing by software. The pulses from detector are analysed in a pulse shape discriminator. A pulse identified as an alpha, beta or gamma event is converted to digital pulse. These digital pulses are accumulated in the three channels on PC interface each corresponding to alpha, beta and gamma. The sample movements are controlled by interface depending upon sample position. The software has been developed so as to maintain user friendliness and convenience of the operator. Various selection modes for parameters and operation of system provide lot of flexibility in operation of the system. (author). 1 fig 9. Effects of beta/gamma radiation on nuclear waste glasses Energy Technology Data Exchange (ETDEWEB) Weber, W.J. [Pacific Northwest National Lab., Richland, WA (United States) 1997-07-01 A key challenge in the disposal of high-level nuclear waste (HLW) in glass waste forms is the development of models of long-term performance based on sound scientific understanding of relevant phenomena. Beta decay of fission products is one source of radiation that can impact the performance of HLW glasses through the interactions of the emitted {beta}-particles and g-rays with the atoms in the glass by ionization processes. Fused silica, alkali silicate glasses, alkali borosilicate glasses, and nuclear waste glasses are all susceptible to radiation effects from ionization. In simple glasses, defects (e.g., non-bridging oxygen and interstitial molecular oxygen) are observed experimentally. In more complex glasses, including nuclear waste glasses, similar defects are expected, and changes in microstructure, such as the formation of bubbles, have been reported. The current state of knowledge regarding the effects of {beta}/{gamma} radiation on the properties and microstructure of nuclear waste glasses are reviewed. (author) 10. Beta activity measurements in high, variable gamma backgrounds International Nuclear Information System (INIS) Stanga, D.; Sandu, E.; Craciun, L. 1997-01-01 In many cases beta activity measurements must be performed in high and variable gamma backgrounds. In such instances it is necessary to use well-shielded detectors but this technique is limited to laboratory equipment and frequently insufficient. In order to perform in a simple manner beta activity measurements in high and variable backgrounds a software-aided counting technique have been developed and a counting system have been constructed. This technique combines the different counting techniques with traditional method of successive measurement of the sample and background. The counting system is based on a programmable multi-scaler which is endowed with appropriate software and allow all operations to be performed via keyboard in an interactive fashion. Two large - area proportional detectors were selected in order to have the same background and the same gamma response within 5%. A program has been developed for the counting data analysis and beta activity computing. The software-aided counting technique has been implemented for beta activity measurement in high and variable backgrounds. (authors) 11. Responses of a grassland arthropod community to chronic beta and gamma radiation International Nuclear Information System (INIS) Styron, C.E.; Dodson, G.J.; Beauchamp, J.J.; Miller, F.L. Jr. 1976-01-01 A long-term project was initiated in 1968 at Oak Ridge National Laboratory to assess effects of mixed beta and gamma radiation from simulated fallout on a grassland ecosystem. Beta and gamma radiation dose rates in microhabitats of the experimentally contaminated enclosure were measured with LiF thermoluminescent microdosimeters. Extensive statistical analyses of data on numbers of individuals collected for each of 76 arthropod and 2 molluscan taxa have identified no lasting significant changes in similarity or species diversity of experimental versus control communities as the result of the long-term irradiation at low dose rates. Natural fluctuations in community dynamics obscured any possible radiation effects. Thus, the apparent threshold for mixed beta and gamma radiation inducing changes in community structure must be above the exposure rate range of 2.3 to 13 rad/day delivered during the 5 yr of observation. Establishing such a threshold is of importance in assessing the impact of communities subjected to chronic, low level environmental exposure to ionizing radiation 12. Skin dose assessment in routine personnel beta/gamma dosimetry International Nuclear Information System (INIS) Christensen, P. 1980-01-01 The International Commission on Radiological Protection (Publication 26) has recommended a tissue depth of 5 to 10 mg.cm -2 for skin dose assessments. This requirement is generally not fulfilled by routine monitoring procedures because of practical difficulties in using very thin dosemeters with low sensitivity and therefore a high minimum detectable dose. Especially for low-energy beta-ray exposures underestimations of the skin dose by a factor of more than ten may occur. Low-transparent graphite-mixed sintered LiF and Li 2 B 4 0 7 : Mn dosemeters were produced which show a skin-equivalent response to beta and gamma exposures over a wide range of energies. These have found wide-spread application for extremity dosimetry but have not yet been generally introduced in routine personnel beta/gamma monitoring. The following adaptations of existing routine monitoring systems for improved skin dose assessments have been investigated: 1) Placement of a supplementary, thin, skin-dose equivalent dosemeter in the TLD badge to give additional information on low-energy exposures. 2) Introduction of a second photomultiplier in the read-out chamber which enables a simultaneous determination of emitted TL from both sides of the dosemeter separately. This method makes use of the selfshielding of the dosemeter to give information on the low-energy dose contribution. 3) By diffusion of Li 2 B 4 0 7 into solid LiF-dosemeters it was possible to produce a surface layer with a new distinct glow-peak at about 340 deg C which is not present in the undiffused part of the LiF chip, and which can be utilized for the assessment of the skin-dose. Data on energy response and accuracy of dose measurement for beta/gamma exposures are given for the three methods and advantages and disadvantages are discussed (H.K.) 13. Design and operation of a prototype incinerator for beta-gamma waste International Nuclear Information System (INIS) Farber, M.G.; Hootman, H.E.; Becker, G.W. Jr.; Makohon, P.A. 1981-01-01 A full-scale test incinerator has been built at the Savannah River Laboratory to provide a design basis for a radioactive facility that will burn low-level beta-gamma contaminated waste. The processing steps include waste feed loading, incineration, ash residue packaging, and off-gas cleanup. Both solid and liquid waste will be incinerated during the test program. The components of the solid waste are cellulose, latex, polyethylene, and PVC; the solvent is composed of n-paraffin and TBP. A research program will confirm the feasibility of the design and determine the operating parameters 14. High-$\\gamma$Beta Beams within the LAGUNA design study CERN Document Server Orme, Christopher 2010-01-01 Within the LAGUNA design study, seven candidate sites are being assessed for their feasibility to host a next-generation, very large neutrino observatory. Such a detector will be expected to feature within a future European accelerator neutrino programme (Superbeam or Beta Beam), and hence the distance from CERN is of critical importance. In this article, the focus is a$^{18}$Ne and$^{6}$He Beta Beam sourced at CERN and directed towards a 50 kton Liquid Argon detector located at the LAGUNA sites: Slanic (L=1570 km) and Pyh\\"{a}salmi (L=2300 km). To improve sensitivity to the neutrino mass ordering, these baselines are then combined with a concurrent run with the same flux directed towards a large Water \\v{C}erenkov detector located at Canfranc (L=650 km). This degeneracy breaking combination is shown to provide comparable physics reach to the conservative Magic Baseline Beta Beam proposals. For$^{18}$Ne ions boosted to$\\gamma=570$and$^{6}$He ions boosted to$\\gamma=350$, the correct mass ordering can be... 15. Resting-state beta and gamma activity in Internet addiction. Science.gov (United States) Choi, Jung-Seok; Park, Su Mi; Lee, Jaewon; Hwang, Jae Yeon; Jung, Hee Yeon; Choi, Sam-Wook; Kim, Dai Jin; Oh, Sohee; Lee, Jun-Young 2013-09-01 Internet addiction is the inability to control one's use of the Internet and is related to impulsivity. Although a few studies have examined neurophysiological activity as individuals with Internet addiction engage in cognitive processing, no information on spontaneous EEG activity in the eyes-closed resting-state is available. We investigated resting-state EEG activities in beta and gamma bands and examined their relationships with impulsivity among individuals with Internet addiction and healthy controls. Twenty-one drug-naïve patients with Internet addiction (age: 23.33 ± 3.50 years) and 20 age-, sex-, and IQ-matched healthy controls (age: 22.40 ± 2.33 years) were enrolled in this study. Severity of Internet addiction was identified by the total score on Young's Internet Addiction Test. Impulsivity was measured with the Barratt Impulsiveness Scale-11 and a stop-signal task. Resting-state EEG during eyes closed was recorded, and the absolute/relative power of beta and gamma bands was analyzed. The Internet addiction group showed high impulsivity and impaired inhibitory control. The generalized estimating equation showed that the Internet-addiction group showed lower absolute power on the beta band than did the control group (estimate = -3.370, p Internet-addiction group showed higher absolute power on the gamma band than did the control group (estimate = 0.434, p Internet addiction as well as with the extent of impulsivity. The present study suggests that resting-state fast-wave brain activity is related to the impulsivity characterizing Internet addiction. These differences may be neurobiological markers for the pathophysiology of Internet addiction. Copyright © 2013 Elsevier B.V. All rights reserved. 16. Hanford beta-gamma personnel dosimeter prototypes and evaluation International Nuclear Information System (INIS) Fix, J.J.; Holbrook, K.L.; Soldat, K.L. 1983-04-01 Upgraded and modified Hanford dosimeter prototypes were evaluated for possible use at Hanford as a primary beta-gamma dosimeter. All prototypes were compatible with the current dosimeter card and holder design, as well as processing with the automated Hanford readers. Shallow- and deep-dose response was determined for selected prototypes using several beta sources, K-fluorescent x rays and filtered x-ray techniques. All prototypes included a neutron sensitive chip. A progressive evaluation of the performance of each of the upgrades to the current dosimeter is described. In general, the performance of the current dosimeter can be upgraded using individual chip sensitivity factors to improve precision and an improved algorithm to minimize bias. The performance of this dosimeter would be adequate to pass all categories of the ANSI N13.11 performance criteria for dosimeter procesors, provided calibration techniques compatible with irradiations adopted in the standard were conducted. The existing neutron capability of the dosimeter could be retained. Better dosimeter performance to beta-gamma radiation can be achieved by modifying the Hanford dosimeter so that four of the five chip positions are devoted to calculating these doses instead of the currently used two chip positions. A neutron sensitive chip was used in the 5th chip position, but all modified dosimeter prototypes would be incapable of discriminating between thermal and epithermal neutrons. An improved low energy beta response can be achieved for the current dosimeter and all prototypes considered by eliminating the security credential. Further improvement can be obtained by incorporating the 15-mil thick TLD-700 chips 17. Beta-gamma counting system for Xe fission products International Nuclear Information System (INIS) Reeder, P.L.; Bowyer, T.W.; Perkins, R.W. 1998-01-01 A beta-gamma coincidence counting system has been developed for automated analysis of Xe gas samples separated from air. The Xe gas samples are contained in a cylindrical plastic scintillator cell located between two NaI(Tl) scintillation detectors. The X-ray and gamma spectra gated by coincident events in the plastic scintillator cell are recorded for each NaI(Tl) crystal. The characteristic signatures of the 131m Xe, 133g Xe, 133m Xe, and 135g Xe isotopes of interest for nuclear test-ban verification as well as the procedures and results of absolute efficiency measurements are described. A NaI(Tl) crystal with provision for 4 sample cells has been implemented for the system to be deployed in the field. Examples of data on ambient air samples in New York City obtained with the field prototype are presented. (author) 18. Simultaneos determination of absorbed doses due to beta and gamma radiations with CaSO4: Dy produced at Ipen International Nuclear Information System (INIS) Campos, L.L.; Rosa, L.A.R. da. 1988-07-01 Due to the Goiania radiological accident, it was necessary to develop urgently a dosimeter in order to evaluate, simultaneously, beta and gamma absorbed doses, due to 137 Cs radiations. Therefore, the Dosimetric Material Production Laboratory of IPEN developed a simple, practical, light and low cost badge using small thickness (0,20mm) thermoluminescent CaSO 4 : Dy pellets produced by the same laboratory. This pellets are adequate for beta radiation detection. These dosimeters were worn by some IPEN technicians who worked in Goiania city, and were used to evaluate the external and internal contaminations presented by the accident victims interned at the Hospital Naval Marcilio Dias. (author) [pt 19. Beta and gamma decay heat evaluation for the thermal fission of 235U International Nuclear Information System (INIS) Schenter, G.K.; Schmittroth, F. 1979-01-01 Beta and gamma fission product decay heat curves are evaluated for the thermal fission of 235 U. Experimental data that include beta, gamma, and total measurements are combined with summation calculations based on ENDF/B in a consistent evaluation. Least-squares methods are used that take proper account of data uncertainties and correlations. 4 figures, 2 tables 20. Perturbed beta-gamma systems and complex geometry Energy Technology Data Exchange (ETDEWEB) Zeitlin, Anton M. [Department of Mathematics, Yale University, 442 Dunham Lab, 10 Hillhouse Avenue, New Haven, CT 06511 (United States)], E-mail: anton.zeitlin@yale.edu 2008-05-11 We consider the equations, arising as the conformal invariance conditions of the perturbed curved beta-gamma system. These equations have the physical meaning of Einstein equations with a B-field and a dilaton on a Hermitian manifold, where the B-field 2-form is imaginary and proportional to the canonical form associated with Hermitian metric. We show that they decompose into linear and bilinear equations and lead to the vanishing of the first Chern class of the manifold where the system is defined. We discuss the relation of these equations to the generalized Maurer-Cartan structures related to BRST operator. Finally we describe the relations of the generalized Maurer-Cartan bilinear operation and the Courant/Dorfman brackets. 1. Modeling dynamic beta-gamma polymorphic transition in Tin Science.gov (United States) Chauvin, Camille; Montheillet, Frank; Petit, Jacques; CEA Gramat Collaboration; EMSE Collaboration 2015-06-01 Solid-solid phase transitions in metals have been studied by shock waves techniques for many decades. Recent experiments have investigated the transition during isentropic compression experiments and shock-wave compression and have highlighted the strong influence of the loading rate on the transition. Complementary data obtained with velocity and temperature measurements around the polymorphic transition beta-gamma of Tin on gas gun experiments have displayed the importance of the kinetics of the transition. But, even though this phenomenon is known, modeling the kinetic remains complex and based on empirical formulations. A multiphase EOS is available in our 1D Lagrangian code Unidim. We propose to present the influence of various kinetic laws (either empirical or involving nucleation and growth mechanisms) and their parameters (Gibbs free energy, temperature, pressure) on the transformation rate. We compare experimental and calculated velocities and temperature profiles and we underline the effects of the empirical parameters of these models. 2. Multi-isotopic gamma-ray assay system for alpha-contaminated waste International Nuclear Information System (INIS) Close, D.A.; Pratt, J.C.; Caldwell, J.T.; Kunz, W.E.; Schultz, F.J.; Haff, K.W. 1983-01-01 The capability of an existing segmented gamma-ray system is being expanded for the analysis of alpha-contaminated waste drums. A cursory assay of 114 transuranic waste drums of 208-l capacity has been made. Analysis of these data indicates a detection limit better than 100 nCi/g of waste for 237 Np/ 233 Pa, 239 Pu, 241 Am, 243 Am/ 239 Np, 60 Co, 125 Sb, 134 137 Cs, and 154 Eu. A pending Code of Federal Regulation (10CFR61) stipulates that the nuclear industry quantify not only its transuranic waste, but also certain beta- and gamma-ray-emitting fission products. An assay system based on gamma-ray spectroscopy is the only system that can meet this requirement for the fission products 3. Standardization of low energy beta and beta-gamma complex emitters by the tracer and the efficiency extrapolation methods International Nuclear Information System (INIS) Sahagia, M. 1978-01-01 The absolute standardization of radioactive solutions of low energy beta emitters and beta-gamma emitters with a high probability of disintegration to the ground state is described; the tracer and the efficiency extrapolation methods were used. Both types of radionuclides were mathematically and physically treated in an unified manner. The theoretical relations between different beta spectra were calculated according to Williams' model and experimentally verified for: 35 S + 60 Co, 35 S + 95 Nb, 147 Pm + 60 Co, 14 C + 95 Nb and two beta branches of 99 Mo. The optimum range of beta efficiency variation was indicated. The basic supposition that all beta efficieny tend to unity in the same time was experimentally verified, using two 192 Ir beta branches. Four computer programs, written in the FORTRAN IV language, were elaborated, for the adequate processing of the experimental data. Good precision coefficients according to international standards were obtained in the absolute standardization of 35 S, 147 Pm, 99 Mo solutions. (author) 4. Hand Monitor for Simultaneous Measurements of Alpha and Beta Contamination Energy Technology Data Exchange (ETDEWEB) Andersson, I Oe; Braun, J; Soederlund, B 1960-11-15 An instrument is described which measures {alpha} and {beta} contamination of the hands simultaneously. This has been achieved by using as detectors 8 flow counters paired in 4 units of two chambers, one unit for each side of the hand. The inner chamber of every unit (adjacent to the hands) delivers {alpha}-pulses, the outer chambers deliver {beta}-pulses. When two finger contacts are pushed the detectors are closing around the hands and the measurement is started. Audible and visual warnings operate when the MPL is exceeded. Similar warnings ope.rate if hands are removed before the end of the counting period. The activity levels are logarithmically indicated on four pointer instruments, which are automatically zeroed when the next measurement is started. The instrument is now commercially available. 5. Using support vector machine to predict beta- and gamma-turns in proteins. Science.gov (United States) Hu, Xiuzhen; Li, Qianzhong 2008-09-01 By using the composite vector with increment of diversity, position conservation scoring function, and predictive secondary structures to express the information of sequence, a support vector machine (SVM) algorithm for predicting beta- and gamma-turns in the proteins is proposed. The 426 and 320 nonhomologous protein chains described by Guruprasad and Rajkumar (Guruprasad and Rajkumar J. Biosci 2000, 25,143) are used for training and testing the predictive model of the beta- and gamma-turns, respectively. The overall prediction accuracy and the Matthews correlation coefficient in 7-fold cross-validation are 79.8% and 0.47, respectively, for the beta-turns. The overall prediction accuracy in 5-fold cross-validation is 61.0% for the gamma-turns. These results are significantly higher than the other algorithms in the prediction of beta- and gamma-turns using the same datasets. In addition, the 547 and 823 nonhomologous protein chains described by Fuchs and Alix (Fuchs and Alix Proteins: Struct Funct Bioinform 2005, 59, 828) are used for training and testing the predictive model of the beta- and gamma-turns, and better results are obtained. This algorithm may be helpful to improve the performance of protein turns' prediction. To ensure the ability of the SVM method to correctly classify beta-turn and non-beta-turn (gamma-turn and non-gamma-turn), the receiver operating characteristic threshold independent measure curves are provided. (c) 2008 Wiley Periodicals, Inc. 6. Gamma radiation sterilises bacteria-contaminated waste International Nuclear Information System (INIS) Anon. 1978-01-01 The use of gamma radiation for the sterilisation of sewage and hospital waste etc., is briefly described. A sterilisation plant delivered by Sulzer is illustrated diagrammatically and its functioning explained, while a photograph illustrates a similar plant delivered by Geodel Systems, of Canada. The latter firm has adapted this type of plant for the radiolytical destruction of phenols, cyanides, alkyl benzenesulphonates and similar wastes. (JIW) 7. CaSO4: Dy + Teflon dosimetric pellets for X, beta and gamma radiation detection International Nuclear Information System (INIS) Campos, L.L.; Lima, M.F. 1987-08-01 CaSO 4 : Dy + TEFLON dosimetric pellets with high sensitivity and low cost for X, beta and gamma radiation monitoring were studied and developed by the Dosimetric Material Production Laboratory of the Radiological Protection Departament and are disposable for sale. The thickness of the pellets are suitable for X, beta and gamma radiation measurements. The dosimetric properties of these pellets were determined and presented in this work. The results show the usefulness of 0,20mm thick pellets for beta radiation monitoring and 0,80mm thick pellets for x and gamma radiation detection. (Author) [pt 8. Microcalorimetric and spectrographic studies on host-guest interactions of {alpha}-, {beta}-, {gamma}- and M{beta}-cyclodextrin with resveratrol Energy Technology Data Exchange (ETDEWEB) Li, Hui; Xu, Xiangyu; Liu, Min [College of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng 252059, Shandong Province (China); Sun, Dezhi, E-mail: sundezhisdz@163.com [College of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng 252059, Shandong Province (China); Li, Linwei, E-mail: lilinwei@lcu.edu.cn [College of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng 252059, Shandong Province (China) 2010-10-20 Thermal effects of inclusion processes of {alpha}-, {beta}-, {gamma}- and M{beta}-cyclodextrin with resveratrol (RES) in aqueous solutions were determined by isothermal titration calorimetry (ITC) with nanowatt sensitivity at the temperature of 298.15 K. Standard enthalpy changes, stoichiometry and equilibrium constants of the inclusion complexes were derived from the direct calorimetric data utilizing nonlinear simulation. The thermodynamic parameters were discussed in the light of weak interactions between the host and the guest molecules combining with UV spectral message. The results indicate that all of the complexes formed in the aqueous solutions are in 1:1 stoichiometry. The binding processes of {alpha}-, {beta}- and M{beta}-cyclodextrin with the guest are mainly driven by enthalpy, while that of {gamma}-cyclodextrin with the drug is driven by both enthalpy and entropy. 9. Rearrangement of beta,gamma-unsaturated esters with thallium trinitrate: synthesis of indans bearing a beta-keto ester moiety Directory of Open Access Journals (Sweden) Silva Jr. Luiz F. 2006-01-01 Full Text Available The rearrangement of beta,gamma-unsaturated esters, such as 2-(3,4-dihydronaphthalen-1-yl-propionic acid ethyl ester, with thallium trinitrate (TTN in acetic acid leads to 3-indan-1-yl-2-methyl-3-oxo-propionic acid ethyl ester in good yield, through a ring contraction reaction. The new indans thus obtained feature a beta-keto ester moiety, which would be useful for further functionalization. 10. Analysis of radionuclide mixtures by {alpha}-{gamma} and {beta}-{gamma} coincidences using a simple device; Analyse de melanges de radionucleides par un dispositif simple de coincidences {alpha}-{gamma} et {beta}-{gamma} Energy Technology Data Exchange (ETDEWEB) Pottier, R; Berger, R [Commissariat a l' Energie Atomique, Centre d' Etudes Nucleaires de Fontenay-aux-Roses, 92 (France) 1966-06-01 A procedure is described for the qualitative and quantitative spectrographic analysis of radioactive sources containing two alpha-gamma emitters having the same alpha energy or two beta-gamma emitters having the same gamma energy. The main apparatus is a multichannel pulse-height analyzer including a coincidence circuit. The principle of the method, the synoptic scheme, the electronic device, the type of sources, and the precautions to be taken or the corrections to take into account are reported. The results obtained in solving the three following problems are discussed as examples of applications of the method: analysis of {sup 241}Am in alpha-gamma sources containing {sup 238}Pu; analysis of {sup 237}Np in beta-gamma sources containing {sup 239}Pu; and analysis of {sup 106}Ru-{sup 106}Rh in beta-gamma sources containing {sup 95}Zr-{sup 95}Nb. (authors) [French] Dans ce. rapport, on presente une methode d'analyse spectrographique qualitative et quantitative de sources radioactives contenant deux emetteurs alpha-gamma de meme energie alpha et deux emetteurs beta-gamma de meme energie gamma. L'organe principal est un analyseur d'amplitude a 400 canaux comprenant un circuit de coincidence. On decrit le principe de la methode, le schema synoptique, l'appareillage, le type des sources, les precautions a prendre ou les corrections a faire. On discute les resultats obtenus dans la solution des trois problemes suivants traites a titre d'application de la methode: 1. analyse d'americium 241 en presence de plutonium 238; 2. analyse de neptunium 237 en presence de plutonium 239; 3. analyse de ruthenium 106-rhodium 106 en presence de zirconium 95-niobium 95. (auteurs) 11. A new extremity dosemeter for beta and gamma radiation International Nuclear Information System (INIS) Heinzelmann, M.; Pagenkamper, M. 1988-01-01 An extremity dosemeter developed at the Juelich Nuclear Research Centre is very well suited for the precise and energy-independent measurement of the skin dose generated by beta or gamma radiation. This is also confirmed by the results of this intercomparison programme. The dosemeter contains three TLDs of LiF in Teflon mounted behind a window of 0.9 mg/cm 2 . The great advantage of this dosemeter is three TLD's enabling statements about the radiation quality. However, the dosemeter has two disadvantages The dosemeter is complicated to manufacture. A very thin plastic foil of 0.9 mg/cm 2 must be attached to a support. This work is difficult and time-consuming and cannot be automated. The window in front of the TLD is not sturdy enough and is occasionally destroyed when the dosemeter is being worn. These two disadvantages prevent this extremity dosemeter from being used more frequently. For this reason, work was begun on developing a new extremity dosemeter without these two disadvantages. The great advantage of the previous dosemeter of obtaining statements about the type of radiation with the aid of readings from three TLD's was to be retained. The improved extremity dosemeter has a more sturdy and thicker window with a similar response as the previous dosemeter with a thinner window 12. Beta and gamma dose calculations for PWR and BWR containments International Nuclear Information System (INIS) King, D.B. 1989-07-01 Analyses of gamma and beta dose in selected regions in PWR and BWR containment buildings have been performed for a range of fission product releases from selected severe accidents. The objective of this study was to determine the radiation dose that safety-related equipment could experience during the selected severe accident sequences. The resulting dose calculations demonstrate the extent to which design basis accident qualified equipment could also be qualified for the severe accident environments. Surry was chosen as the representative PWR plant while Peach Bottom was selected to represent BWRs. Battelle Columbus Laboratory performed the source term release analyses. The AB epsilon scenario (an intermediate to large LOCA with failure to recover onsite or offsite electrical power) was selected as the base case Surry accident, and the AE scenario (a large break LOCA with one initiating event and a combination of failures in two emergency cooling systems) was selected as the base case Peach Bottom accident. Radionuclide release was bounded for both scenarios by including spray operation and arrested sequences as variations of the base scenarios. Sandia National Laboratories used the source terms to calculate dose to selected containment regions. Scenarios with sprays operational resulted in a total dose comparable to that (2.20 x 10 8 rads) used in current equipment qualification testing. The base case scenarios resulted in some calculated doses roughly an order of magnitude above the current 2.20 x 10 8 rad equipment qualification test region. 8 refs., 23 figs., 12 tabs 13. Alpha/beta(gamma ray) discrimination and spillover quantification with a BaF2 scintillator International Nuclear Information System (INIS) DeVol, T.A.; Fjeld, R.A. 1994-01-01 A simple pulse shape discrimination technique was used to separate alpha and beta(gamma ray) interactions in a BaF 2 scintillator. The separation was not ideal, resulting in a 5.1% spillover of alpha interactions into the beta(gamma ray) channel and 11.9% spillover of beta(gamma ray) interactions into the alpha channel for a set pulse shape discriminator. The misclassification of events was reduced by post-processing the data using either a simple analytical technique or a more complex linear least squares technique. Both techniques typically reduced the difference between the expected and calculated interaction rates to <10% when the ratio of beta(gamma ray) to alpha count rate was less than 100 : 1. ((orig.)) 14. Effect of beta and gamma neurofeedback on memory and intelligence in the elderly NARCIS (Netherlands) Staufenbiel, S.M.; Brouwer, A.M.; Keizer, A.W.; Wouwe, N.C. van 2014-01-01 Recent research showed a correlation between cognitive decline and a decrease of EEG gamma activity. In the present double-blind randomized control study, we investigated whether gamma and beta neurofeedback protocols, that have been shown to modulate performance on cognitive control and memory in 15. Support vector machines for prediction and analysis of beta and gamma-turns in proteins. Science.gov (United States) Pham, Tho Hoan; Satou, Kenji; Ho, Tu Bao 2005-04-01 Tight turns have long been recognized as one of the three important features of proteins, together with alpha-helix and beta-sheet. Tight turns play an important role in globular proteins from both the structural and functional points of view. More than 90% tight turns are beta-turns and most of the rest are gamma-turns. Analysis and prediction of beta-turns and gamma-turns is very useful for design of new molecules such as drugs, pesticides, and antigens. In this paper we investigated two aspects of applying support vector machine (SVM), a promising machine learning method for bioinformatics, to prediction and analysis of beta-turns and gamma-turns. First, we developed two SVM-based methods, called BTSVM and GTSVM, which predict beta-turns and gamma-turns in a protein from its sequence. When compared with other methods, BTSVM has a superior performance and GTSVM is competitive. Second, we used SVMs with a linear kernel to estimate the support of amino acids for the formation of beta-turns and gamma-turns depending on their position in a protein. Our analysis results are more comprehensive and easier to use than the previous results in designing turns in proteins. 16. Interferences in Prompt {gamma} Analysis of corrosive contaminants in concrete Energy Technology Data Exchange (ETDEWEB) Naqvi, A.A. [Department of Physics, King Fahd University of Petroleum and Minerals, KFUPM Box 1815, Dhahran-31261 (Saudi Arabia)]. E-mail: aanaqvi@kfupm.edu.sa; Nagadi, M.M. [Department of Physics, King Fahd University of Petroleum and Minerals, KFUPM Box 1815, Dhahran-31261 (Saudi Arabia); Al-Amoudi, O.S.B. [Department of Civil Engineering, King Fahd University of Petroleum and Minerals, Dhahran (Saudi Arabia) 2006-12-21 An accelerator-based Prompt Gamma Neutron Activation Analysis (PGNAA) setup has been developed to measure the concentration of corrosive chloride and sulfate contaminants in concrete. The Minimum Detectable Concentration (MDC) limit of chlorine and sulfur in the concrete depends upon the {gamma}-ray used for elemental analysis. For more interfering {gamma}-rays, the MDC limit is higher than that for less interfering {gamma}-rays. The MDC limit of sulfur in concrete measured for the KFUPM PGNAA setup was calculated to be 0.60{+-}0.19 wt%. The MDC limit is equal to the upper limit of sulfur concentration in concrete set by the British Standards. The MDC limit of chlorine in concrete for the KFUPM PGNAA setup, which was calculated for less interfering 1.165 MeV {gamma}-rays, was found to be 0.075{+-}0.025 wt%. The lower limits of the MDC of chlorine in concrete was 73% higher than the limit set by American Concrete Institute. The limit of the MDC can be improved to the desired standard by increasing the intensity of neutron source. For moreinterfering 5.715 and 6.110 MeV chlorine {gamma}-rays the MDC limit was found to be 2-3 times larger than that of 1.165 MeV {gamma}-rays. When normalized to the same intensity of the neutron source, the MDC limits of chlorine and sulfur in concrete from the KFUPM PGNAA setup are better than MDC limits of chlorine in concrete obtained with the {sup 241}Am-Be source-based PGNAA setup. This study has shown that an accelerator-based PGNAA setup can be used in chlorine and sulfur analysis of concrete samples. 17. Study of radiation detectors response in standard X, gamma and beta radiation standard beams International Nuclear Information System (INIS) Nonato, Fernanda Beatrice Conceicao 2010-01-01 The response of 76 Geiger-Mueller detectors, 4 semiconductor detectors and 34 ionization chambers were studied. Many of them were calibrated with gamma radiation beams ( 37 Cs and 60 Co), and some of them were tested in beta radiation ( 90 Sr+ 9' 0Y e 204 Tl) and X radiation (N-60, N-80, N-100, N-150) beams. For all three types of radiation, the calibration factors of the instruments were obtained, and the energy and angular dependences were studied. For beta and gamma radiation, the angular dependence was studied for incident radiation angles of 0 deg and +- 45 deg. The curves of the response of the instruments were obtained over an angle interval of 0 deg to +- 90 deg, for gamma, beta and X radiations. The calibration factors obtained for beta radiation were compared to those obtained for gamma radiation. For gamma radiation, 24 of the 66 tested Geiger-Mueller detectors presented results for the energy dependence according to international recommendation of ISO 4037-2 and 56 were in accordance with the Brazilian ABNT 10011 recommendation. The ionization chambers and semiconductors were in accordance to national and international recommendations. All instruments showed angular dependence less than 40%. For beta radiation, the instruments showed unsatisfactory results for the energy dependence and angular dependence. For X radiation, the ionization chambers presented results for energy dependence according to the national recommendation, and the angular dependence was less than 40%. (author) 18. Differential expression of largemouth bass (Micropterus salmoides) estrogen receptor isotypes alpha, beta, and gamma by estradiol. Science.gov (United States) Sabo-Attwood, Tara; Kroll, Kevin J; Denslow, Nancy D 2004-04-15 The expression levels of three estrogen receptor (ER) isotypes alpha, beta, and gamma were quantified in female largemouth bass (Micropterus salmoides) (LMB) liver, ovary, brain, and pituitary tissues. ER alpha and beta expression predominated in the liver, while ERs beta and gamma predominated in the other tissues. Temporally in females, ER alpha was highly up-regulated, ER gamma was slightly up-regulated, and ER beta levels remained unchanged in the liver when plasma 17-beta estradiol (E2) and vitellogenin (Vtg) levels were elevated in the spring. In ovarian tissue from these same fish, all three ERs were maximally expressed in the fall, during early oocyte development and prior to peak plasma E2 levels. When males were injected with E2, ER alpha was highly inducible, ER gamma was moderately up-regulated, and ER beta levels were not affected. None of the ER isotypes were induced by E2 in gonadal tissues. These results combined suggest that the ERs themselves are not regulated in the same manner by E2, and furthermore, do not contribute equally to the transcriptional regulation of genes involved in fish reproduction such as Vtg. 19. Mixing of ground-state rotational and gamma and beta vibrational bands in the region A>=228 Energy Technology Data Exchange (ETDEWEB) Mittal, R; Sahota, H S [Punjabi Univ., Patiala (India). Dept. of Physics 1983-06-21 The mixing of beta, gamma and ground-state bands has been investigated through the experimental determination of mixing parameters Zsub(..gamma..) and Zsub(..beta gamma..). These Zsub(..gamma..) values have been compared with the theoretical calculations of this parameter from the solutions of time-dependent HFB equations on the adiabatic and nonadiabatic assumptions. The experimental values are in better agreement with the results obtained under the nonadiabatic assumption, valid for small deviations from the spherical symmetry. 20. Functions of Beta- and Gamma-Catenins in Prostate Cancer National Research Council Canada - National Science Library Reed, John 2001-01-01 .... We recently discovered that the protein Siah-1 interacts with the APC/catenin complex, and regulates the ubiquitin-dependent turnover of beta-catenin through a novel previously unidentified mechanism... 1. Comparison of gamma- and beta radiation stress responses on anti-oxidative defense system and DNA modifications in Lemna minor Energy Technology Data Exchange (ETDEWEB) Van Hoeck, Arne [SCK.CEN, Boeretang 200 2400 Mol (Belgium); University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen (Belgium); Horemans, Nele; Van Hees, May; Nauts, Robin; Vandenhove, Hildegarde [SCK.CEN, Boeretang 200 2400 Mol (Belgium); Knapen, Dries; Blust, Ronny [University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen (Belgium) 2014-07-01 The biological effects and interactions of different radiation types in plants are still far from understood. Additional knowledge on the impact of various kinds of ionizing radiation in plants on individual, biochemical and molecular level is needed to unravel and compare the toxic mode of action. Among different radiation types, external gamma radiation treatments have been mostly studied both in lab and field studies to derive the biological impact of radiation toxicity in organisms. However, environmental relevant studies on chronic low-dose gamma exposures are scarce. The radio-ecologically relevant radionuclide {sup 90}Sr is a pure beta emitting isotope and originates from nuclear activities and accidents. Although this radionuclide is not essential for plant metabolism, it bears a chemical analogy with the essential plant macro-nutrient Ca{sup 2+} thereby taking advantage of Ca{sup 2+} transport systems to contaminate plant organs and tissues. Ones plants are exposed to radiation stress, ionization events can cause an increase in reactive oxygen species (ROS) and can induce damage to biological material like DNA, lipids and structural proteins. The following work aimed at evaluating individual, biochemical and molecular endpoints to understand and to compare the mode of action of gamma- and beta radiation stress in plants. Having an equal relative biological effectiveness to non-human biota, it is still not clear in how plants differ or overlap in sensing and interpreting highly penetrating electromagnetic radiation with short-range particle radiation. The floating plant Lemna minor was chosen as model system. Following the OECD guidelines Lemna plants were being exposed separately to an external gamma radiation source or to a {sup 90}Sr-contaminated growth medium to obtain single-dose response curves for each type of radiation. In order to acquire accurate dose rate quantifications for beta radiation exposures, {sup 90}Sr uptake and accumulation of root and 2. Beta Autoradiography. An analytical technique to investigate radionuclides contamination on surface International Nuclear Information System (INIS) Ficher, P.; Goutelard, F.; Siitari-Kauppi, M. 2012-01-01 In decommissioning of old buildings and after disposal of nuclear facilities (materials, glove boxes,...), the inventory of the radioactive contamination of various building materials needs to be obtained in order to fix the working condition for dismantling. The challenge of this study was to classify different building materials of a whole research laboratory that was dedicated to research on organic molecules labeled with H-3 and C-14. The problem of waste classification is essential for safety treatment of waste and also for its cost. The analytical technique of beta autoradiography particularly well known for biological researches has been tested to investigate radionuclides contamination on surface. This technique is mainly interesting for beta and alpha emitters but also sensitive to gamma radiation. The first step of this technique is the deposit of a film on the surface of material to be analyzed. Films can be deposited on the ground or also fixed on the walls or even on the ceiling. The film is a plastic sheet covered with an emulsion containing photostimulable crystals and Eu that is activated when the film is exposed on radioactive source. The exposed films are then scanned with the Cyclone Plus equipment to get a digitized image. This image represents the radioactivity of the surface studied. The possibility to re-use the films is very important to investigate a large area. This autoradiography technique has retained our attention for its sensitivity and moreover the possibility of 2-dimensional investigation has been found as a real advantage. However it remains now as a qualitative technique and new studies must be launched to prove its quantitative potentialities. The high spatial resolution was not as important as in biological observation, and the mm resolution is totally sufficient 3. Optimization of plastic scintillator thicknesses for online beta/gamma detection Directory of Open Access Journals (Sweden) Pourtangestani K. 2012-04-01 Full Text Available For efficient beta detection in a mixed beta gamma field, Monte Carlo simulation models have been built to optimize the thickness of a plastic scintillator, used in a whole body monitor. The simulation has been performed using the MCNP/X code for different thicknesses of plastic scintillator from 150 μm to 600 μm. The relationship between the thickness of the scintillator and the efficiency of the detector has been analyzed. For 150 μm thickness, an experimental investigation has been conducted with different beta sources at different positions on the scintillator and the counting efficiency of the unit has been measured. Evaluated data along with experimental ones have been discussed. A thickness of 300 μm to 500 μm has been found to be the optimum thickness for high efficiency beta detection in the presence of low energy gamma-rays. 4. Ornithogalum virens as a plant assay for beta and gamma radiation effects International Nuclear Information System (INIS) Herron, V.J. 1979-01-01 The purpose of this study was to determine if the monocotyledonous angiosperm, Ornithogalum virens (Quintanilha and Cabral, 1947), could be used in such a biological assay system. After exposing O. virens plants to acute ( 60 Co) and chronic ( 137 Cs) gamma radiation and internal beta radiation ( 32 P), lethality (LD 50 , LD 100 ), growth inhibition, and chromosome aberrations were investigated. The LD 50 and LD 100 for acute gamma radiation were estimated to be between 0.91 to 1.8 krad and less than 3.6 krad, respectively. Though growth inhibition and abnormal growth were observed in the acute and chronic gamma radiation studies, the changes in the growth of the plants were so variable that these parameters were found to be unreliable measures of radiation effects. Chromosome aberrations were a more reliable measure of radiation damage because linear relationships between total aberrations and dose were found for both gamma and beta radiation 5. Determination of$\\gamma$and$-2\\beta_s$from charmless two-body decays of beauty mesons CERN Document Server Aaij, Roel; Adeva, Bernardo; Adinolfi, Marco; Affolder, Anthony; Ajaltouni, Ziad; Akar, Simon; Albrecht, Johannes; Alessio, Federico; Alexander, Michael; Ali, Suvayu; Alkhazov, Georgy; Alvarez Cartelle, Paula; Alves Jr, Antonio Augusto; Amato, Sandra; Amerio, Silvia; Amhis, Yasmine; An, Liupan; Anderlini, Lucio; Anderson, Jonathan; Andreassen, Rolf; Andreotti, Mirco; Andrews, Jason; Appleby, Robert; Aquines Gutierrez, Osvaldo; Archilli, Flavio; Artamonov, Alexander; Artuso, Marina; Aslanides, Elie; Auriemma, Giulio; Baalouch, Marouen; Bachmann, Sebastian; Back, John; Badalov, Alexey; Baesso, Clarissa; Baldini, Wander; Barlow, Roger; Barschel, Colin; Barsuk, Sergey; Barter, William; Batozskaya, Varvara; Battista, Vincenzo; Bay, Aurelio; Beaucourt, Leo; Beddow, John; Bedeschi, Franco; Bediaga, Ignacio; Belogurov, Sergey; Belous, Konstantin; Belyaev, Ivan; Ben-Haim, Eli; Bencivenni, Giovanni; Benson, Sean; Benton, Jack; Berezhnoy, Alexander; Bernet, Roland; Bettler, Marc-Olivier; van Beuzekom, Martinus; Bien, Alexander; Bifani, Simone; Bird, Thomas; Bizzeti, Andrea; Bjørnstad, Pål Marius; Blake, Thomas; Blanc, Frédéric; Blouw, Johan; Blusk, Steven; Bocci, Valerio; Bondar, Alexander; Bondar, Nikolay; Bonivento, Walter; Borghi, Silvia; Borgia, Alessandra; Borsato, Martino; Bowcock, Themistocles; Bowen, Espen Eie; Bozzi, Concezio; Brambach, Tobias; Bressieux, Joël; Brett, David; Britsch, Markward; Britton, Thomas; Brodzicka, Jolanta; Brook, Nicholas; Brown, Henry; Bursche, Albert; Busetto, Giovanni; Buytaert, Jan; Cadeddu, Sandro; Calabrese, Roberto; Calvi, Marta; Calvo Gomez, Miriam; Campana, Pierluigi; Campora Perez, Daniel; Carbone, Angelo; Carboni, Giovanni; Cardinale, Roberta; Cardini, Alessandro; Carson, Laurence; Carvalho Akiba, Kazuyoshi; Casse, Gianluigi; Cassina, Lorenzo; Castillo Garcia, Lucia; Cattaneo, Marco; Cauet, Christophe; Cenci, Riccardo; Charles, Matthew; Charpentier, Philippe; Chefdeville, Maximilien; Chen, Shanzhen; Cheung, Shu-Faye; Chiapolini, Nicola; Chrzaszcz, Marcin; Ciba, Krzystof; Cid Vidal, Xabier; Ciezarek, Gregory; Clarke, Peter; Clemencic, Marco; Cliff, Harry; Closier, Joel; Coco, Victor; Cogan, Julien; Cogneras, Eric; Cojocariu, Lucian; Collins, Paula; Comerma-Montells, Albert; Contu, Andrea; Cook, Andrew; Coombes, Matthew; Coquereau, Samuel; Corti, Gloria; Corvo, Marco; Counts, Ian; Couturier, Benjamin; Cowan, Greig; Craik, Daniel Charles; Cruz Torres, Melissa Maria; Cunliffe, Samuel; Currie, Robert; D'Ambrosio, Carmelo; Dalseno, Jeremy; David, Pascal; David, Pieter; Davis, Adam; De Bruyn, Kristof; De Capua, Stefano; De Cian, Michel; De Miranda, Jussara; De Paula, Leandro; De Silva, Weeraddana; De Simone, Patrizia; Decamp, Daniel; Deckenhoff, Mirko; Del Buono, Luigi; Déléage, Nicolas; Derkach, Denis; Deschamps, Olivier; Dettori, Francesco; Di Canto, Angelo; Dijkstra, Hans; Donleavy, Stephanie; Dordei, Francesca; Dorigo, Mirco; Dosil Suárez, Alvaro; Dossett, David; Dovbnya, Anatoliy; Dreimanis, Karlis; Dujany, Giulio; Dupertuis, Frederic; Durante, Paolo; Dzhelyadin, Rustem; Dziurda, Agnieszka; Dzyuba, Alexey; Easo, Sajan; Egorychev, Victor; Eidelman, Semen; Eisenhardt, Stephan; Eitschberger, Ulrich; Ekelhof, Robert; Eklund, Lars; El Rifai, Ibrahim; Elsasser, Christian; Ely, Scott; Esen, Sevda; Evans, Hannah Mary; Evans, Timothy; Falabella, Antonio; Färber, Christian; Farinelli, Chiara; Farley, Nathanael; Farry, Stephen; Fay, Robert; Ferguson, Dianne; Fernandez Albor, Victor; Ferreira Rodrigues, Fernando; Ferro-Luzzi, Massimiliano; Filippov, Sergey; Fiore, Marco; Fiorini, Massimiliano; Firlej, Miroslaw; Fitzpatrick, Conor; Fiutowski, Tomasz; Fol, Philip; Fontana, Marianna; Fontanelli, Flavio; Forty, Roger; Francisco, Oscar; Frank, Markus; Frei, Christoph; Frosini, Maddalena; Fu, Jinlin; Furfaro, Emiliano; Gallas Torreira, Abraham; Galli, Domenico; Gallorini, Stefano; Gambetta, Silvia; Gandelman, Miriam; Gandini, Paolo; Gao, Yuanning; García Pardiñas, Julián; Garofoli, Justin; Garra Tico, Jordi; Garrido, Lluis; Gaspar, Clara; Gauld, Rhorry; Gavardi, Laura; Gavrilov, Gennadii; Geraci, Angelo; Gersabeck, Evelina; Gersabeck, Marco; Gershon, Timothy; Ghez, Philippe; Gianelle, Alessio; Gianì, Sebastiana; Gibson, Valerie; Giubega, Lavinia-Helena; Gligorov, Vladimir; Göbel, Carla; Golubkov, Dmitry; Golutvin, Andrey; Gomes, Alvaro; Gotti, Claudio; Grabalosa Gándara, Marc; Graciani Diaz, Ricardo; Granado Cardoso, Luis Alberto; Graugés, Eugeni; Graziani, Giacomo; Grecu, Alexandru; Greening, Edward; Gregson, Sam; Griffith, Peter; Grillo, Lucia; Grünberg, Oliver; Gui, Bin; Gushchin, Evgeny; Guz, Yury; Gys, Thierry; Hadjivasiliou, Christos; Haefeli, Guido; Haen, Christophe; Haines, Susan; Hall, Samuel; Hamilton, Brian; Hampson, Thomas; Han, Xiaoxue; Hansmann-Menzemer, Stephanie; Harnew, Neville; Harnew, Samuel; Harrison, Jonathan; He, Jibo; Head, Timothy; Heijne, Veerle; Hennessy, Karol; Henrard, Pierre; Henry, Louis; Hernando Morata, Jose Angel; van Herwijnen, Eric; Heß, Miriam; Hicheur, Adlène; Hill, Donal; Hoballah, Mostafa; Hombach, Christoph; Hulsbergen, Wouter; Hunt, Philip; Hussain, Nazim; Hutchcroft, David; Hynds, Daniel; Idzik, Marek; Ilten, Philip; Jacobsson, Richard; Jaeger, Andreas; Jalocha, Pawel; Jans, Eddy; Jaton, Pierre; Jawahery, Abolhassan; Jing, Fanfan; John, Malcolm; Johnson, Daniel; Jones, Christopher; Joram, Christian; Jost, Beat; Jurik, Nathan; Kaballo, Michael; Kandybei, Sergii; Kanso, Walaa; Karacson, Matthias; Karbach, Moritz; Karodia, Sarah; Kelsey, Matthew; Kenyon, Ian; Ketel, Tjeerd; Khanji, Basem; Khurewathanakul, Chitsanu; Klaver, Suzanne; Klimaszewski, Konrad; Kochebina, Olga; Kolpin, Michael; Komarov, Ilya; Koopman, Rose; Koppenburg, Patrick; Korolev, Mikhail; Kozlinskiy, Alexandr; Kravchuk, Leonid; Kreplin, Katharina; Kreps, Michal; Krocker, Georg; Krokovny, Pavel; Kruse, Florian; Kucewicz, Wojciech; Kucharczyk, Marcin; Kudryavtsev, Vasily; Kurek, Krzysztof; Kvaratskheliya, Tengiz; La Thi, Viet Nga; Lacarrere, Daniel; Lafferty, George; Lai, Adriano; Lambert, Dean; Lambert, Robert W; Lanfranchi, Gaia; Langenbruch, Christoph; Langhans, Benedikt; Latham, Thomas; Lazzeroni, Cristina; Le Gac, Renaud; van Leerdam, Jeroen; Lees, Jean-Pierre; Lefèvre, Regis; Leflat, Alexander; Lefrançois, Jacques; Leo, Sabato; Leroy, Olivier; Lesiak, Tadeusz; Leverington, Blake; Li, Yiming; Likhomanenko, Tatiana; Liles, Myfanwy; Lindner, Rolf; Linn, Christian; Lionetto, Federica; Liu, Bo; Lohn, Stefan; Longstaff, Iain; Lopes, Jose; Lopez-March, Neus; Lowdon, Peter; Lu, Haiting; Lucchesi, Donatella; Luo, Haofei; Lupato, Anna; Luppi, Eleonora; Lupton, Oliver; Machefert, Frederic; Machikhiliyan, Irina V; Maciuc, Florin; Maev, Oleg; Malde, Sneha; Malinin, Alexander; Manca, Giulia; Mancinelli, Giampiero; Mapelli, Alessandro; Maratas, Jan; Marchand, Jean François; Marconi, Umberto; Marin Benito, Carla; Marino, Pietro; Märki, Raphael; Marks, Jörg; Martellotti, Giuseppe; Martens, Aurelien; Martín Sánchez, Alexandra; Martinelli, Maurizio; Martinez Santos, Diego; Martinez Vidal, Fernando; Martins Tostes, Danielle; Massafferri, André; Matev, Rosen; Mathe, Zoltan; Matteuzzi, Clara; Mazurov, Alexander; McCann, Michael; McCarthy, James; McNab, Andrew; McNulty, Ronan; McSkelly, Ben; Meadows, Brian; Meier, Frank; Meissner, Marco; Merk, Marcel; Milanes, Diego Alejandro; Minard, Marie-Noelle; Moggi, Niccolò; Molina Rodriguez, Josue; Monteil, Stephane; Morandin, Mauro; Morawski, Piotr; Mordà, Alessandro; Morello, Michael Joseph; Moron, Jakub; Morris, Adam Benjamin; Mountain, Raymond; Muheim, Franz; Müller, Katharina; Mussini, Manuel; Muster, Bastien; Naik, Paras; Nakada, Tatsuya; Nandakumar, Raja; Nasteva, Irina; Needham, Matthew; Neri, Nicola; Neubert, Sebastian; Neufeld, Niko; Neuner, Max; Nguyen, Anh Duc; Nguyen, Thi-Dung; Nguyen-Mau, Chung; Nicol, Michelle; Niess, Valentin; Niet, Ramon; Nikitin, Nikolay; Nikodem, Thomas; Novoselov, Alexey; O'Hanlon, Daniel Patrick; Oblakowska-Mucha, Agnieszka; Obraztsov, Vladimir; Oggero, Serena; Ogilvy, Stephen; Okhrimenko, Oleksandr; Oldeman, Rudolf; Onderwater, Gerco; Orlandea, Marius; Otalora Goicochea, Juan Martin; Owen, Patrick; Oyanguren, Maria Arantza; Pal, Bilas Kanti; Palano, Antimo; Palombo, Fernando; Palutan, Matteo; Panman, Jacob; Papanestis, Antonios; Pappagallo, Marco; Pappalardo, Luciano; Parkes, Christopher; Parkinson, Christopher John; Passaleva, Giovanni; Patel, Girish; Patel, Mitesh; Patrignani, Claudia; Pazos Alvarez, Antonio; Pearce, Alex; Pellegrino, Antonio; Pepe Altarelli, Monica; Perazzini, Stefano; Perez Trigo, Eliseo; Perret, Pascal; Perrin-Terrin, Mathieu; Pescatore, Luca; Pesen, Erhan; Petridis, Konstantin; Petrolini, Alessandro; Picatoste Olloqui, Eduardo; Pietrzyk, Boleslaw; Pilař, Tomas; Pinci, Davide; Pistone, Alessandro; Playfer, Stephen; Plo Casasus, Maximo; Polci, Francesco; Poluektov, Anton; Polycarpo, Erica; Popov, Alexander; Popov, Dmitry; Popovici, Bogdan; Potterat, Cédric; Price, Eugenia; Price, Joseph David; Prisciandaro, Jessica; Pritchard, Adrian; Prouve, Claire; Pugatch, Valery; Puig Navarro, Albert; Punzi, Giovanni; Qian, Wenbin; Rachwal, Bartolomiej; Rademacker, Jonas; Rakotomiaramanana, Barinjaka; Rama, Matteo; Rangel, Murilo; Raniuk, Iurii; Rauschmayr, Nathalie; Raven, Gerhard; Redi, Federico; Reichert, Stefanie; Reid, Matthew; dos Reis, Alberto; Ricciardi, Stefania; Richards, Sophie; Rihl, Mariana; Rinnert, Kurt; Rives Molina, Vincente; Robbe, Patrick; Rodrigues, Ana Barbara; Rodrigues, Eduardo; Rodriguez Perez, Pablo; Roiser, Stefan; Romanovsky, Vladimir; Romero Vidal, Antonio; Rotondo, Marcello; Rouvinet, Julien; Ruf, Thomas; Ruiz, Hugo; Ruiz Valls, Pablo; Saborido Silva, Juan Jose; Sagidova, Naylya; Sail, Paul; Saitta, Biagio; Salustino Guimaraes, Valdir; Sanchez Mayordomo, Carlos; Sanmartin Sedes, Brais; Santacesaria, Roberta; Santamarina Rios, Cibran; Santovetti, Emanuele; Sarti, Alessio; Satriano, Celestina; Satta, Alessia; Saunders, Daniel Martin; Savrie, Mauro; Savrina, Darya; Schiller, Manuel; Schindler, Heinrich; Schlupp, Maximilian; Schmelling, Michael; Schmidt, Burkhard; Schneider, Olivier; Schopper, Andreas; Schune, Marie Helene; Schwemmer, Rainer; Sciascia, Barbara; Sciubba, Adalberto; Seco, Marcos; Semennikov, Alexander; Sepp, Indrek; Serra, Nicola; Serrano, Justine; Sestini, Lorenzo; Seyfert, Paul; Shapkin, Mikhail; Shapoval, Illya; Shcheglov, Yury; Shears, Tara; Shekhtman, Lev; Shevchenko, Vladimir; Shires, Alexander; Silva Coutinho, Rafael; Simi, Gabriele; Sirendi, Marek; Skidmore, Nicola; Skwarnicki, Tomasz; Smith, Anthony; Smith, Edmund; Smith, Eluned; Smith, Jackson; Smith, Mark; Snoek, Hella; Sokoloff, Michael; Soler, Paul; Soomro, Fatima; Souza, Daniel; Souza De Paula, Bruno; Spaan, Bernhard; Sparkes, Ailsa; Spradlin, Patrick; Sridharan, Srikanth; Stagni, Federico; Stahl, Marian; Stahl, Sascha; Steinkamp, Olaf; Stenyakin, Oleg; Stevenson, Scott; Stoica, Sabin; Stone, Sheldon; Storaci, Barbara; Stracka, Simone; Straticiuc, Mihai; Straumann, Ulrich; Stroili, Roberto; Subbiah, Vijay Kartik; Sun, Liang; Sutcliffe, William; Swientek, Krzysztof; Swientek, Stefan; Syropoulos, Vasileios; Szczekowski, Marek; Szczypka, Paul; Szilard, Daniela; Szumlak, Tomasz; T'Jampens, Stephane; Teklishyn, Maksym; Tellarini, Giulia; Teubert, Frederic; Thomas, Christopher; Thomas, Eric; van Tilburg, Jeroen; Tisserand, Vincent; Tobin, Mark; Tolk, Siim; Tomassetti, Luca; Topp-Joergensen, Stig; Torr, Nicholas; Tournefier, Edwige; Tourneur, Stephane; Tran, Minh Tâm; Tresch, Marco; Tsaregorodtsev, Andrei; Tsopelas, Panagiotis; Tuning, Niels; Ubeda Garcia, Mario; Ukleja, Artur; Ustyuzhanin, Andrey; Uwer, Ulrich; Vacca, Claudia; Vagnoni, Vincenzo; Valenti, Giovanni; Vallier, Alexis; Vazquez Gomez, Ricardo; Vazquez Regueiro, Pablo; Vázquez Sierra, Carlos; Vecchi, Stefania; Velthuis, Jaap; Veltri, Michele; Veneziano, Giovanni; Vesterinen, Mika; Viaud, Benoit; Vieira, Daniel; Vieites Diaz, Maria; Vilasis-Cardona, Xavier; Vollhardt, Achim; Volyanskyy, Dmytro; Voong, David; Vorobyev, Alexey; Vorobyev, Vitaly; Voß, Christian; Voss, Helge; de Vries, Jacco; Waldi, Roland; Wallace, Charlotte; Wallace, Ronan; Walsh, John; Wandernoth, Sebastian; Wang, Jianchun; Ward, David; Watson, Nigel; Websdale, David; Whitehead, Mark; Wicht, Jean; Wiedner, Dirk; Wilkinson, Guy; Williams, Matthew; Williams, Mike; Wilschut, Hans; Wilson, Fergus; Wimberley, Jack; Wishahi, Julian; Wislicki, Wojciech; Witek, Mariusz; Wormser, Guy; Wotton, Stephen; Wright, Simon; Wyllie, Kenneth; Xie, Yuehong; Xing, Zhou; Xu, Zhirui; Yang, Zhenwei; Yuan, Xuhao; Yushchenko, Oleg; Zangoli, Maria; Zavertyaev, Mikhail; Zhang, Liming; Zhang, Wen Chao; Zhang, Yanxi; Zhelezov, Alexey; Zhokhov, Anatoly; Zhong, Liang; Zvyagin, Alexander 2015-01-01 Using the latest LHCb measurements of time-dependent$C\\!P$violation in the$B^0_s \\to K^+K^-$decay, a U-spin relation between the decay amplitudes of$B^0_s \\to K^+K^-$and$B^0\\to \\pi^+\\pi^-$decay processes allows constraints to be placed on the angle$\\gamma$of the unitarity triangle and on the$B^0_s$mixing phase$-2\\beta_s$. Results from an extended approach, which uses additional inputs on$B^0\\to \\pi^0\\pi^0$and$B^+\\to \\pi^+\\pi^0$decays from other experiments and exploits isospin symmetry, are also presented. The dependence of the results on the maximum allowed amount of U-spin breaking is studied. At 68% probability, the value$\\gamma = \\left( 63.5^{\\,+\\, 7.2}_{\\,-\\,6.7} \\right)^\\circ~\\mathrm{modulo}~180^\\circ$is determined. In an alternative analysis, the value$-2\\beta_s = -0.12 ^{\\,+\\,0.14}_{\\,-\\,0.16}\\,\\,\\mathrm{rad}$is found. In both measurements, the uncertainties due to U-spin breaking effects up to 50% are included. 6. Determination of$\\gamma$and$-2\\beta_s$from charmless two-body decays of beauty mesons CERN Document Server Aaij, Roel; Adeva, Bernardo; Adinolfi, Marco; Affolder, Anthony; Ajaltouni, Ziad; Akar, Simon; Albrecht, Johannes; Alessio, Federico; Alexander, Michael; Ali, Suvayu; Alkhazov, Georgy; Alvarez Cartelle, Paula; Alves Jr, Antonio Augusto; Amato, Sandra; Amerio, Silvia; Amhis, Yasmine; An, Liupan; Anderlini, Lucio; Anderson, Jonathan; Andreassen, Rolf; Andreotti, Mirco; Andrews, Jason; Appleby, Robert; Aquines Gutierrez, Osvaldo; Archilli, Flavio; Artamonov, Alexander; Artuso, Marina; Aslanides, Elie; Auriemma, Giulio; Baalouch, Marouen; Bachmann, Sebastian; Back, John; Badalov, Alexey; Baesso, Clarissa; Baldini, Wander; Barlow, Roger; Barschel, Colin; Barsuk, Sergey; Barter, William; Batozskaya, Varvara; Battista, Vincenzo; Bay, Aurelio; Beaucourt, Leo; Beddow, John; Bedeschi, Franco; Bediaga, Ignacio; Belogurov, Sergey; Belous, Konstantin; Belyaev, Ivan; Ben-Haim, Eli; Bencivenni, Giovanni; Benson, Sean; Benton, Jack; Berezhnoy, Alexander; Bernet, Roland; Bettler, Marc-Olivier; van Beuzekom, Martinus; Bien, Alexander; Bifani, Simone; Bird, Thomas; Bizzeti, Andrea; Bjørnstad, Pål Marius; Blake, Thomas; Blanc, Frédéric; Blouw, Johan; Blusk, Steven; Bocci, Valerio; Bondar, Alexander; Bondar, Nikolay; Bonivento, Walter; Borghi, Silvia; Borgia, Alessandra; Borsato, Martino; Bowcock, Themistocles; Bowen, Espen Eie; Bozzi, Concezio; Brambach, Tobias; Bressieux, Joël; Brett, David; Britsch, Markward; Britton, Thomas; Brodzicka, Jolanta; Brook, Nicholas; Brown, Henry; Bursche, Albert; Busetto, Giovanni; Buytaert, Jan; Cadeddu, Sandro; Calabrese, Roberto; Calvi, Marta; Calvo Gomez, Miriam; Campana, Pierluigi; Campora Perez, Daniel; Carbone, Angelo; Carboni, Giovanni; Cardinale, Roberta; Cardini, Alessandro; Carson, Laurence; Carvalho Akiba, Kazuyoshi; Casse, Gianluigi; Cassina, Lorenzo; Castillo Garcia, Lucia; Cattaneo, Marco; Cauet, Christophe; Cenci, Riccardo; Charles, Matthew; Charpentier, Philippe; Chefdeville, Maximilien; Chen, Shanzhen; Cheung, Shu-Faye; Chiapolini, Nicola; Chrzaszcz, Marcin; Ciba, Krzystof; Cid Vidal, Xabier; Ciezarek, Gregory; Clarke, Peter; Clemencic, Marco; Cliff, Harry; Closier, Joel; Coco, Victor; Cogan, Julien; Cogneras, Eric; Cojocariu, Lucian; Collins, Paula; Comerma-Montells, Albert; Contu, Andrea; Cook, Andrew; Coombes, Matthew; Coquereau, Samuel; Corti, Gloria; Corvo, Marco; Counts, Ian; Couturier, Benjamin; Cowan, Greig; Craik, Daniel Charles; Cruz Torres, Melissa Maria; Cunliffe, Samuel; Currie, Robert; D'Ambrosio, Carmelo; Dalseno, Jeremy; David, Pascal; David, Pieter; Davis, Adam; De Bruyn, Kristof; De Capua, Stefano; De Cian, Michel; De Miranda, Jussara; De Paula, Leandro; De Silva, Weeraddana; De Simone, Patrizia; Decamp, Daniel; Deckenhoff, Mirko; Del Buono, Luigi; Déléage, Nicolas; Derkach, Denis; Deschamps, Olivier; Dettori, Francesco; Di Canto, Angelo; Dijkstra, Hans; Donleavy, Stephanie; Dordei, Francesca; Dorigo, Mirco; Dosil Suárez, Alvaro; Dossett, David; Dovbnya, Anatoliy; Dreimanis, Karlis; Dujany, Giulio; Dupertuis, Frederic; Durante, Paolo; Dzhelyadin, Rustem; Dziurda, Agnieszka; Dzyuba, Alexey; Easo, Sajan; Egorychev, Victor; Eidelman, Semen; Eisenhardt, Stephan; Eitschberger, Ulrich; Ekelhof, Robert; Eklund, Lars; El Rifai, Ibrahim; Elsasser, Christian; Ely, Scott; Esen, Sevda; Evans, Hannah Mary; Evans, Timothy; Falabella, Antonio; Färber, Christian; Farinelli, Chiara; Farley, Nathanael; Farry, Stephen; Fay, Robert; Ferguson, Dianne; Fernandez Albor, Victor; Ferreira Rodrigues, Fernando; Ferro-Luzzi, Massimiliano; Filippov, Sergey; Fiore, Marco; Fiorini, Massimiliano; Firlej, Miroslaw; Fitzpatrick, Conor; Fiutowski, Tomasz; Fol, Philip; Fontana, Marianna; Fontanelli, Flavio; Forty, Roger; Francisco, Oscar; Frank, Markus; Frei, Christoph; Frosini, Maddalena; Fu, Jinlin; Furfaro, Emiliano; Gallas Torreira, Abraham; Galli, Domenico; Gallorini, Stefano; Gambetta, Silvia; Gandelman, Miriam; Gandini, Paolo; Gao, Yuanning; García Pardiñas, Julián; Garofoli, Justin; Garra Tico, Jordi; Garrido, Lluis; Gaspar, Clara; Gauld, Rhorry; Gavardi, Laura; Gavrilov, Gennadii; Geraci, Angelo; Gersabeck, Evelina; Gersabeck, Marco; Gershon, Timothy; Ghez, Philippe; Gianelle, Alessio; Gianì, Sebastiana; Gibson, Valerie; Giubega, Lavinia-Helena; Gligorov, V.V.; Göbel, Carla; Golubkov, Dmitry; Golutvin, Andrey; Gomes, Alvaro; Gotti, Claudio; Grabalosa Gándara, Marc; Graciani Diaz, Ricardo; Granado Cardoso, Luis Alberto; Graugés, Eugeni; Graziani, Giacomo; Grecu, Alexandru; Greening, Edward; Gregson, Sam; Griffith, Peter; Grillo, Lucia; Grünberg, Oliver; Gui, Bin; Gushchin, Evgeny; Guz, Yury; Gys, Thierry; Hadjivasiliou, Christos; Haefeli, Guido; Haen, Christophe; Haines, Susan; Hall, Samuel; Hamilton, Brian; Hampson, Thomas; Han, Xiaoxue; Hansmann-Menzemer, Stephanie; Harnew, Neville; Harnew, Samuel; Harrison, Jonathan; He, Jibo; Head, Timothy; Heijne, Veerle; Hennessy, Karol; Henrard, Pierre; Henry, Louis; Hernando Morata, Jose Angel; van Herwijnen, Eric; Heß, Miriam; Hicheur, Adlène; Hill, Donal; Hoballah, Mostafa; Hombach, Christoph; Hulsbergen, Wouter; Hunt, Philip; Hussain, Nazim; Hutchcroft, David; Hynds, Daniel; Idzik, Marek; Ilten, Philip; Jacobsson, Richard; Jaeger, Andreas; Jalocha, Pawel; Jans, Eddy; Jaton, Pierre; Jawahery, Abolhassan; Jing, Fanfan; John, Malcolm; Johnson, Daniel; Jones, Christopher; Joram, Christian; Jost, Beat; Jurik, Nathan; Kaballo, Michael; Kandybei, Sergii; Kanso, Walaa; Karacson, Matthias; Karbach, Moritz; Karodia, Sarah; Kelsey, Matthew; Kenyon, Ian; Ketel, Tjeerd; Khanji, Basem; Khurewathanakul, Chitsanu; Klaver, Suzanne; Klimaszewski, Konrad; Kochebina, Olga; Kolpin, Michael; Komarov, Ilya; Koopman, Rose; Koppenburg, Patrick; Korolev, Mikhail; Kozlinskiy, Alexandr; Kravchuk, Leonid; Kreplin, Katharina; Kreps, Michal; Krocker, Georg; Krokovny, Pavel; Kruse, Florian; Kucewicz, Wojciech; Kucharczyk, Marcin; Kudryavtsev, Vasily; Kurek, Krzysztof; Kvaratskheliya, Tengiz; La Thi, Viet Nga; Lacarrere, Daniel; Lafferty, George; Lai, Adriano; Lambert, Dean; Lambert, Robert W; Lanfranchi, Gaia; Langenbruch, Christoph; Langhans, Benedikt; Latham, Thomas; Lazzeroni, Cristina; Le Gac, Renaud; van Leerdam, Jeroen; Lees, Jean-Pierre; Lefèvre, Regis; Leflat, Alexander; Lefrançois, Jacques; Leo, Sabato; Leroy, Olivier; Lesiak, Tadeusz; Leverington, Blake; Li, Yiming; Likhomanenko, Tatiana; Liles, Myfanwy; Lindner, Rolf; Linn, Christian; Lionetto, Federica; Liu, Bo; Lohn, Stefan; Longstaff, Iain; Lopes, Jose; Lopez-March, Neus; Lowdon, Peter; Lu, Haiting; Lucchesi, Donatella; Luo, Haofei; Lupato, Anna; Luppi, Eleonora; Lupton, Oliver; Machefert, Frederic; Machikhiliyan, Irina V; Maciuc, Florin; Maev, Oleg; Malde, Sneha; Malinin, Alexander; Manca, Giulia; Mancinelli, Giampiero; Mapelli, Alessandro; Maratas, Jan; Marchand, Jean François; Marconi, Umberto; Marin Benito, Carla; Marino, Pietro; Märki, Raphael; Marks, Jörg; Martellotti, Giuseppe; Martens, Aurelien; Martín Sánchez, Alexandra; Martinelli, Maurizio; Martinez Santos, Diego; Martinez Vidal, Fernando; Martins Tostes, Danielle; Massafferri, André; Matev, Rosen; Mathe, Zoltan; Matteuzzi, Clara; Mazurov, Alexander; McCann, Michael; McCarthy, James; McNab, Andrew; McNulty, Ronan; McSkelly, Ben; Meadows, Brian; Meier, Frank; Meissner, Marco; Merk, Marcel; Milanes, Diego Alejandro; Minard, Marie-Noelle; Moggi, Niccolò; Molina Rodriguez, Josue; Monteil, Stephane; Morandin, Mauro; Morawski, Piotr; Mordà, Alessandro; Morello, Michael Joseph; Moron, Jakub; Morris, Adam Benjamin; Mountain, Raymond; Muheim, Franz; Müller, Katharina; Mussini, Manuel; Muster, Bastien; Naik, Paras; Nakada, Tatsuya; Nandakumar, Raja; Nasteva, Irina; Needham, Matthew; Neri, Nicola; Neubert, Sebastian; Neufeld, Niko; Neuner, Max; Nguyen, Anh Duc; Nguyen, Thi-Dung; Nguyen-Mau, Chung; Nicol, Michelle; Niess, Valentin; Niet, Ramon; Nikitin, Nikolay; Nikodem, Thomas; Novoselov, Alexey; O'Hanlon, Daniel Patrick; Oblakowska-Mucha, Agnieszka; Obraztsov, Vladimir; Oggero, Serena; Ogilvy, Stephen; Okhrimenko, Oleksandr; Oldeman, Rudolf; Onderwater, Gerco; Orlandea, Marius; Otalora Goicochea, Juan Martin; Owen, Patrick; Oyanguren, Maria Arantza; Pal, Bilas Kanti; Palano, Antimo; Palombo, Fernando; Palutan, Matteo; Panman, Jacob; Papanestis, Antonios; Pappagallo, Marco; Pappalardo, Luciano; Parkes, Christopher; Parkinson, Christopher John; Passaleva, Giovanni; Patel, Girish; Patel, Mitesh; Patrignani, Claudia; Pazos Alvarez, Antonio; Pearce, Alex; Pellegrino, Antonio; Pepe Altarelli, Monica; Perazzini, Stefano; Perez Trigo, Eliseo; Perret, Pascal; Perrin-Terrin, Mathieu; Pescatore, Luca; Pesen, Erhan; Petridis, Konstantin; Petrolini, Alessandro; Picatoste Olloqui, Eduardo; Pietrzyk, Boleslaw; Pilař, Tomas; Pinci, Davide; Pistone, Alessandro; Playfer, Stephen; Plo Casasus, Maximo; Polci, Francesco; Poluektov, Anton; Polycarpo, Erica; Popov, Alexander; Popov, Dmitry; Popovici, Bogdan; Potterat, Cédric; Price, Eugenia; Price, Joseph David; Prisciandaro, Jessica; Pritchard, Adrian; Prouve, Claire; Pugatch, Valery; Puig Navarro, Albert; Punzi, Giovanni; Qian, Wenbin; Rachwal, Bartolomiej; Rademacker, Jonas; Rakotomiaramanana, Barinjaka; Rama, Matteo; Rangel, Murilo; Raniuk, Iurii; Rauschmayr, Nathalie; Raven, Gerhard; Redi, Federico; Reichert, Stefanie; Reid, Matthew; dos Reis, Alberto; Ricciardi, Stefania; Richards, Sophie; Rihl, Mariana; Rinnert, Kurt; Rives Molina, Vincente; Robbe, Patrick; Rodrigues, Ana Barbara; Rodrigues, Eduardo; Rodriguez Perez, Pablo; Roiser, Stefan; Romanovsky, Vladimir; Romero Vidal, Antonio; Rotondo, Marcello; Rouvinet, Julien; Ruf, Thomas; Ruiz, Hugo; Ruiz Valls, Pablo; Saborido Silva, Juan Jose; Sagidova, Naylya; Sail, Paul; Saitta, Biagio; Salustino Guimaraes, Valdir; Sanchez Mayordomo, Carlos; Sanmartin Sedes, Brais; Santacesaria, Roberta; Santamarina Rios, Cibran; Santovetti, Emanuele; Sarti, Alessio; Satriano, Celestina; Satta, Alessia; Saunders, Daniel Martin; Savrie, Mauro; Savrina, Darya; Schiller, Manuel; Schindler, Heinrich; Schlupp, Maximilian; Schmelling, Michael; Schmidt, Burkhard; Schneider, Olivier; Schopper, Andreas; Schune, Marie Helene; Schwemmer, Rainer; Sciascia, Barbara; Sciubba, Adalberto; Seco, Marcos; Semennikov, Alexander; Sepp, Indrek; Serra, Nicola; Serrano, Justine; Sestini, Lorenzo; Seyfert, Paul; Shapkin, Mikhail; Shapoval, Illya; Shcheglov, Yury; Shears, Tara; Shekhtman, Lev; Shevchenko, Vladimir; Shires, Alexander; Silva Coutinho, Rafael; Simi, Gabriele; Sirendi, Marek; Skidmore, Nicola; Skwarnicki, Tomasz; Smith, Anthony; Smith, Edmund; Smith, Eluned; Smith, Jackson; Smith, Mark; Snoek, Hella; Sokoloff, Michael; Soler, Paul; Soomro, Fatima; Souza, Daniel; Souza De Paula, Bruno; Spaan, Bernhard; Sparkes, Ailsa; Spradlin, Patrick; Sridharan, Srikanth; Stagni, Federico; Stahl, Marian; Stahl, Sascha; Steinkamp, Olaf; Stenyakin, Oleg; Stevenson, Scott; Stoica, Sabin; Stone, Sheldon; Storaci, Barbara; Stracka, Simone; Straticiuc, Mihai; Straumann, Ulrich; Stroili, Roberto; Subbiah, Vijay Kartik; Sun, Liang; Sutcliffe, William; Swientek, Krzysztof; Swientek, Stefan; Syropoulos, Vasileios; Szczekowski, Marek; Szczypka, Paul; Szilard, Daniela; Szumlak, Tomasz; T'Jampens, Stephane; Teklishyn, Maksym; Tellarini, Giulia; Teubert, Frederic; Thomas, Christopher; Thomas, Eric; van Tilburg, Jeroen; Tisserand, Vincent; Tobin, Mark; Tolk, Siim; Tomassetti, Luca; Topp-Joergensen, Stig; Torr, Nicholas; Tournefier, Edwige; Tourneur, Stephane; Tran, Minh Tâm; Tresch, Marco; Tsaregorodtsev, Andrei; Tsopelas, Panagiotis; Tuning, Niels; Ubeda Garcia, Mario; Ukleja, Artur; Ustyuzhanin, Andrey; Uwer, Ulrich; Vacca, Claudia; Vagnoni, Vincenzo; Valenti, Giovanni; Vallier, Alexis; Vazquez Gomez, Ricardo; Vazquez Regueiro, Pablo; Vázquez Sierra, Carlos; Vecchi, Stefania; Velthuis, Jaap; Veltri, Michele; Veneziano, Giovanni; Vesterinen, Mika; Viaud, Benoit; Vieira, Daniel; Vieites Diaz, Maria; Vilasis-Cardona, Xavier; Vollhardt, Achim; Volyanskyy, Dmytro; Voong, David; Vorobyev, Alexey; Vorobyev, Vitaly; Voß, Christian; Voss, Helge; de Vries, Jacco; Waldi, Roland; Wallace, Charlotte; Wallace, Ronan; Walsh, John; Wandernoth, Sebastian; Wang, Jianchun; Ward, David; Watson, Nigel; Websdale, David; Whitehead, Mark; Wicht, Jean; Wiedner, Dirk; Wilkinson, Guy; Williams, Matthew; Williams, Mike; Wilschut, Hans; Wilson, Fergus; Wimberley, Jack; Wishahi, Julian; Wislicki, Wojciech; Witek, Mariusz; Wormser, Guy; Wotton, Stephen; Wright, Simon; Wyllie, Kenneth; Xie, Yuehong; Xing, Zhou; Xu, Zhirui; Yang, Zhenwei; Yuan, Xuhao; Yushchenko, Oleg; Zangoli, Maria; Zavertyaev, Mikhail; Zhang, Liming; Zhang, Wen Chao; Zhang, Yanxi; Zhelezov, Alexey; Zhokhov, Anatoly; Zhong, Liang; Zvyagin, Alexander 2015-02-04 Using the latest LHCb measurements of time-dependent$C\\!P$violation in the$B^0_s \\to K^+K^-$decay, a U-spin relation between the decay amplitudes of$B^0_s \\to K^+K^-$and$B^0\\to \\pi^+\\pi^-$decay processes allows constraints to be placed on the angle$\\gamma$of the unitarity triangle and on the$B^0_s$mixing phase$-2\\beta_s$. Results from an extended approach, which uses additional inputs on$B^0\\to \\pi^0\\pi^0$and$B^+\\to \\pi^+\\pi^0$decays from other experiments and exploits isospin symmetry, are also presented. The dependence of the results on the maximum allowed amount of U-spin breaking is studied. At 68% probability, the value$\\gamma = \\left( 63.5^{\\,+\\, 7.2}_{\\,-\\,6.7} \\right)^\\circ~\\mathrm{modulo}~180^\\circ$is determined. In an alternative analysis, the value$-2\\beta_s = -0.12 ^{\\,+\\,0.14}_{\\,-\\,0.16}\\,\\,\\mathrm{rad}$is found. In both measurements, the uncertainties due to U-spin breaking effects up to 50% are included. 7. Development and Application of Devices for Remote Monitoring of Gamma-Ray Contamination at RECOM Ltd International Nuclear Information System (INIS) Ivanov, O.P.; Stepanov, V.E.; Chesnokov, A.V.; Sudarkin, A.N.; Urutskoev, L.I. 1999-01-01 Devices for remote monitoring of gamma-ray contamination develop at RECOM Ltd. are described and typical examples of their application are show. The following devices are discussed: spectrum-sensitive collimated devices for mapping of radioactivity on contaminated surfaces- scanning collimated Gamma Locator, device for field Cs-137 contamination mapping-CORAD; devices for gamma-ray imaging computer-controlled High-Energy Radiation Visualizer (HERV) and Coded Mask Imager 8. High Sensitivity Detection of Xe Isotopes Via Beta-Gamma Coincidence Counting International Nuclear Information System (INIS) Bowyer, Ted W.; McIntyre, Justin I.; Reeder, Paul L. 1999-01-01 Measurement of xenon fission product isotopes is a key element in the global network being established to monitor the Comprehensive Nuclear-Test-Ban Treaty. Pacific Northwest National Laboratory has developed an automated system for separating Xe from air which includes a beta-gamma counting system for 131mXe, 133mXe, 133Xe, and 135Xe. Betas and conversion electrons are detected in a plastic scintillation cell containing the Xe sample. The counting geometry is nearly 100% for beta and conversion electrons. The resolution in the pulse height spectrum from the plastic scintillator is sufficient to observe distinct peaks for specific conversion electrons. Gamma and X-rays are detected in a NaI(Tl) scintillation detector which surrounds the plastic scintillator sample cell. Two-dimensional pulse height spectra of gamma energy versus beta energy are obtained. Each of the four xenon isotopes has a distinctive signature in the two-dimensional energy array. The details of the counting system, examples of two-dimensional beta-gamma data, and operational experience with this counting system will be described 9. Solved problems in analysis as applied to gamma, beta, Legendre and Bessel functions CERN Document Server Farrell, Orin J 2013-01-01 Nearly 200 problems, each with a detailed, worked-out solution, deal with the properties and applications of the gamma and beta functions, Legendre polynomials, and Bessel functions. The first two chapters examine gamma and beta functions, including applications to certain geometrical and physical problems such as heat-flow in a straight wire. The following two chapters treat Legendre polynomials, addressing applications to specific series expansions, steady-state heat-flow temperature distribution, gravitational potential of a circular lamina, and application of Gauss's mechanical quadrature 10. Analysis method for beta-gamma coincidence spectra from radio-xenon isotopes International Nuclear Information System (INIS) Yang Wenjing; Yin Jingpeng; Huang Xiongliang; Cheng Zhiwei; Shen Maoquan; Zhang Yang 2012-01-01 Radio-xenon isotopes monitoring is one important method for the verification of CTBT, what includes the measurement methods of HPGe γ spectrometer and β-γ coincidence. The article describes the analytic flowchart and method of three-dimensional beta-gamma coincidence spectra from β-γ systems, and analyses in detail the principles and methods of the regions of interest of coincidence spectra and subtracting the interference, finally gives the formula of radioactivity of Xenon isotopes and minimum detectable concentrations. Studying on the principles of three-dimensional beta-gamma coincidence spectra, which can supply the foundation for designing the software of β-γ coincidence systems. (authors) 11. Experience with melting beta and gamma contaminated metals International Nuclear Information System (INIS) Feaugas, J.; Laplante, D.; Puechlong, Y.; Barbusse, R. 1994-01-01 Following a description of the melting facility operated for purposes of decommissioning the G2 and G3 gas-cooled reactors at Marcoule, the physical and radiological characteristics of 4070 tonnes of metal processed to date in the furnace are discussed. Considerable data have been recorded regarding operating and measurement procedures; the results show that secondary wastes account for less than 5 wt% of the processed scrap metal, and that all the 137 Cs is transferred to the dust and slag. During the last two months of 1993, the ingot mold line was replaced by rails on which dollies carrying integral work-form molds can be moved into position beneath the casting ladle. (authors). 21 figs 12. Functions of Beta- and Gamma-Catenins in Prostate Cancer National Research Council Canada - National Science Library Reed, John 1999-01-01 .... We recently discovered that the protein Siah-1 interacts with the APC/catenin complex, and regulates the ubiquitin-dependent turnover of gamma-catenin through a novel previously unidentified mechanism... 13. Formation of hydrogen fluoride by gamma and beta sterilisation in medical devices containing perfluoroheptane International Nuclear Information System (INIS) Zuendorf, Josef; Kremer, Stefan; Grueger, Thomas 2008-01-01 Infusion of hexadecafluoroheptane, a liquid perfluorocarbon released from repaired Althane dialysers was found to be the most probable reason for the deaths of 53 dialysis patients reported in the year 2001. This study focuses on toxic decomposition products generated due to gamma and beta sterilisation of hexadecafluoroheptane. The responsible dialysers were sterilised with a maximum dose of 45 kGy gamma irradiation. We investigated the influence of both 20-500 kGy gamma and beta irradiation on perfluoroheptane. Analysis of the irradiated samples verified the decomposition of perfluoroheptane in dependence on the dose of irradiation. Beta irradiation resulted in a higher degree of decomposition than the same dose of gamma irradiation. As decomposition products, hydrogen fluoride, CO 2 , and one saturated fluorinated hydrocarbon which could not be analysed exactly were identified. Even at 20 kGy gamma irradiation hydrogen fluoride was detectable. Our results provide evidence that hydrogen fluoride is generated as a highly toxic decomposition product when perfluoroheptane is sterilised with gamma irradiation as it was applied on the affected dialysers. There is no evidence of other toxic degradation products especially perfluoroisobutylene. Therefore, hydrogen fluoride or the dissociated fluoride ions might act as a toxic agent when medical devices containing liquid perfluorocarbons are sterilised by irradiation 14. Xe isotope detection and discrimination using beta spectroscopy with coincident gamma spectroscopy Science.gov (United States) Reeder, P. L.; Bowyer, T. W. 1998-02-01 Beta spectroscopic techniques show promise of significant improvements for a beta-gamma coincidence counter that is part of a system for analyzing Xe automatically separated from air. The previously developed counting system for 131mXe, 133mXe, 133gXe, and 135gXe can be enhanced to give additional discrimination between these Xe isotopes by using the plastic scintillation sample cell as a beta spectrometer to resolve the conversion electron peaks. The automated system will be a key factor in monitoring the Comprehensive Test Ban Treaty. 15. Assay of plutonium contaminated waste by gamma spectrometry International Nuclear Information System (INIS) Adsley, I.; Bull, R.; Davies, M.; Green, M. 2011-01-01 The extreme toxicity of plutonium necessitates the segregation of plutonium contaminated materials (PCM) with extremely small (sub-μg) levels of contamination. The driver to measure accurately these small quantities of plutonium within (relatively) large volumes of waste is (in part) financial. In particular the cost of disposal (per unit volume) rises steeply with increasing waste-category. Within the UK, there has been a historical reluctance to use low energy gamma radiation to sentence PCM because of the potential for self attenuation by dense materials. This is unfortunate because the low-energy gamma radiation from PCM offers the only practicable technique for segregating PCM within the various Low Level Waste (LLW) (>0.4Bq/g) and sub-LLW categories. Whilst passive neutron counting techniques have proved successful for assay of waste well into the Intermediate Level Waste (ILW) (>100Bq/g) category, a cursory study reveals that these techniques are barely capable of detecting mg quantities of plutonium -- let alone the sub-μg quantities present in LLW. This paper considers the use of two types of gamma detector for assay of PCM: the thin sodium iodide FIDLER (Field Instrument for the Detection of Low Energy Radiation) and the HPGe (High Purity Germanium) detector. Systems utilising these two types of detector can provide complementary information. FIDLER measurements are conducted by careful, local, systematic monitoring of surfaces. By contrast a HPGe detector can be used to monitor entire walls, or even rooms, in one measurement. Thus, a HPGe detector placed in the centre of room (from which any radioactive hot-spots have previously been removed) could be used to demonstrate that the average activity remaining close to the surface of the walls/floor/ceiling is below a given limit. The Monte Carlo Code MCNP 1 has been used to model both FIDLER probe and HPGe detector in the measurement geometries described above. The MCNP simulations have been validated 16. New information on the$\\beta$-decay of$^{11}$Li from Doppler broadened$\\gamma$-lines CERN Document Server Fynbo, H O U; Cederkäll, J; Courtin, S; Dessagne, P; Jonson, B; Le Scornet, G; Nilsson, T; Nyman, G H; Poirier, E; Riisager, K; Tengblad, O; Wilhelmsen, K 2004-01-01 The$\\gamma$-ray spectrum following$\\beta$-decay of$^{11}$Li has been remeasured at the ISOLDE facility at CERN. Two new transitions were observed through the use of large Ge-detectors. Most$\\gamma$-decays will follow P-delayed neutron emission. Information on the energy of the neutron is derived from analysis of the$\\gamma$-line-shape and used to construct a partial decay scheme for$^{11}$Li. Lifetime values for the 1$^{-}$and 2$^{-}$levels in$^{10}$Be are also derived. A new partial decay scheme is presented. (43 refs). 17. Mapping of contaminated sites using mobile gamma spectrometry: Marcassin system International Nuclear Information System (INIS) Panza, F.; Demongeot, S.; Crosland, E.; Foissard, B. 2015-01-01 Document available in abstract form only. Full text of publication follows: As part of the development of a tool for use in a nuclear emergency, post-accident situations and contaminated sites, the Institute for Radiation Protection and Nuclear Safety (IRSN) has designed an instrument for mapping natural and artificial radioactivity in soil using in situ gamma spectrometry. The development of this mobile system is based on various studies initiated by IRSN. The tool, named MARCASSIN (Moyen Autoporteur pour la Realisation de Cartographies de l'Activite Sur Sites contamINes, or automotive resource for mapping radioactivity at contaminated sites), has already been used to characterise various types of sites: contaminated soil (Fukushima), old open-pit mines (centre of France) and environmental sites (Paris region). Mounted on a quad-type vehicle, the instrument is composed of a spectrometer, a radiation meter and a global positioning system. Using coordinates and nuclear data, results are given in the form of mapping indicating type of radionuclides, radioactivity level, dose rate and contamination distribution in real-time. To improve detection level above sites where radioactivity levels are low, the system also is capable of processing data. Two of these methods are as follows: the first, 're-meshing', improves the estimate of soil radioactivity by increasing measurement statistics. The results agree with the reference values (soil samples measured in the laboratory), even for normal environmental levels of radioactivity. The second method, for which a patent is pending, is based on a deconvolution of mapping data. Re-processing deducts the impulse response of MARCASSIN from the radiation flux measurements in order to restore the value sought, which is the soil emission rate by radiological energy or activity. A theoretical example demonstrates the possibilities of this method. (authors) 18. Effect of the gamma radiation of cobalt 60 on the beta carotids present in the carrot International Nuclear Information System (INIS) Perez Lopez, Sergio Victor Hugo 1997-01-01 In the present work it was investigated the effect of the gamma radiation of cobalt 60 on the beta carotid's in the carrot (daucus carota), using for it three different radiation dose (100, 150 and 200 kilo-rad) and analyzing them by means of the liquid chromatography technique of high resolution (HPLC) 19. The influence of interleukin-1beta on gamma-glutamyl transpeptidase activity in rat hippocampus Czech Academy of Sciences Publication Activity Database Kaiser, M.; Mareš, Vladislav; Šťastný, František; Bubeníková-Valešová, V.; Lisá, Věra; Suchomel, P.; Balcar, V. J. 2006-01-01 Roč. 55, č. 4 (2006), s. 461-465 ISSN 0862-8408 R&D Projects: GA MZd(CZ) NF7626 Institutional research plan: CEZ:AV0Z50110509 Keywords : interleukin-1beta * gamma- glutamyltranspeptidase * hippocampus Subject RIV: ED - Physiology Impact factor: 2.093, year: 2006 20. On k-Gamma and k-Beta Distributions and Moment Generating Functions Directory of Open Access Journals (Sweden) Gauhar Rahman 2014-01-01 Full Text Available The main objective of the present paper is to define k-gamma and k-beta distributions and moments generating function for the said distributions in terms of a new parameter k>0. Also, the authors prove some properties of these newly defined distributions. 1. Development of Simultaneous Beta-and-Coincidence-Gamma Imager for Plant Imaging Research Energy Technology Data Exchange (ETDEWEB) Tai, Yuan-Chuan [Washington Univ., St. Louis, MO (United States). School of Medicine 2016-09-30 The goal of this project is to develop a novel imaging system that can simultaneously acquire beta and coincidence gamma images of positron sources in thin objects such as leaves of plants. This hybrid imager can be used to measure carbon assimilation in plants quantitatively and in real-time after C-11 labeled carbon-dioxide is administered. A better understanding of carbon assimilation, particularly under the increasingly elevated atmospheric CO2 level, is extremely critical for plant scientists who study food crop and biofuel production. Phase 1 of this project is focused on the technology development with 3 specific aims: (1) develop a hybrid detector that can detect beta and gamma rays simultaneously; (2) develop an imaging system that can differentiate these two types of radiation and acquire beta and coincidence gamma images in real-time; (3) develop techniques to quantify radiotracer distribution using beta and gamma images. Phase 2 of this project is to apply technologies developed in phase 1 to study plants using positron-emitting radionuclide such as 11C to study carbon assimilation in biofuel plants. 2. ORNL shielded facilities capable of remote handling of highly radioactive beta--gamma emitting materials International Nuclear Information System (INIS) Whitson, W.R. 1977-09-01 A survey of ORNL facilities having adequate shielding and containment for the remote handling of experimental quantities of highly radioactive beta-gamma emitting materials is summarized. Portions of the detailed descriptions of these facilities previously published in ORNL/TM-1268 are still valid and are repeated 3. Estimation of radiation exposures due to the exemption of beta-contaminated radioactive materials International Nuclear Information System (INIS) Beltz, D.; Botsch, W.; Huettig, M.; Boerchers, F. 2005-01-01 The authors have checked the individual clearance levels of pure beta-emitters (Sr 89, Sr 90+) according to Anlage III, Table 1, column 8 and 10 StrlSchV for the clearance of buildings. According to Monte-Carlo simulations the direct exposure coming from contaminated parts of a building can exceed the range of trivial doses significantly, although the clearance levels are met. Furthermore, the high radiation level outside a barrel of beta-emitting waste showed that even the mass-specific clearance levels for the disposal of beta-contaminated waste need to be reviewed. (orig.) 4. Selective Beta and Gamma-ray Discrimination by CdWO{sub 4} and PlasticScintillator Energy Technology Data Exchange (ETDEWEB) Bae, Jun Woo; Kim, Hee Reyoung [Dept. of Nuclear Engineering, Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of) 2017-04-15 Radiation monitoring technique has been used for monitoring of decommissioning site of nuclear facility, radioactive waste disposal site, or in case of radioactivity accident. For rapid measurement of gamma-ray and beta-ray, many portable radiation detectors were developed but they are sensitive to specific radiation type. For example, portable detectors using NaI(Tl) or high purity germanium (HPGe) are suitable to detect gamma-ray. Otherwise, Geiger-müller (GM) tube or ionization chamber are suitable to detect all-types of radiation but it is hard to determine which particle is detected in the detector. In this reason, phoswich detectors for discrimination of beta-ray and gamma-ray were developed by using pulse shape discrimination. In this study, another approach to discriminate the beta-ray and gamma-ray is carried out. Two scintillators are used, cadmium tungstate (CdWO{sub 4}) and plastic scintillator. They have huge difference in their effective atomic number and mass density, thus they have huge difference in their gamma-ray sensitivity while the sensitivity of beta-ray is similar. The characterization of beta-ray and gamma-ray discrimination by using this characteristics is include. A technique of discrimination between beta-ray and gamma-ray was suggested. The method was verified by Monte Carlo simulation and experiment. This work showed feasibility on in field measurement of radiation with discrimination of beta-ray and gamma-ray. 5. {beta}-{gamma} systems and the deformations of the BRST operator Energy Technology Data Exchange (ETDEWEB) Zeitlin, Anton M [Department of Mathematics, Yale University, 442 Dunham Lab, 10 Hillhouse Ave, New Haven, CT 06511 (United States)], E-mail: anton.zeitlin@yale.edu 2009-09-04 We describe the relation between simple logarithmic CFTs associated with closed and open strings, and their 'infinite metric' limits, corresponding to the {beta}-{gamma} systems. This relation is studied on the level of the BRST complex: we show that the consideration of metric as a perturbation leads to a certain deformation of the algebraic operations of the Lian-Zuckerman type on the vertex algebra, associated with the {beta}-{gamma} systems. The Maurer-Cartan equations corresponding to this deformed structure in the quasi-classical approximation lead to the nonlinear field equations. As an explicit example, we demonstrate that using this construction, Yang-Mills equations can be derived. This gives rise to a nontrivial relation between the Courant-Dorfman algebroid and homotopy algebras emerging from the gauge theory. We also discuss a possible algebraic approach to the study of beta-functions in sigma-models. 6. Determination of gross gamma and gross beta activities in liquid effluent samples. Phase I International Nuclear Information System (INIS) Curtis, K.E.; Sood, S.P. 1985-08-01 Several inadequacies in the presently used procedures for gross gamma and gross beta measurements in aqueous wastes have been identified. Both the presence of suspended particulate activity and the use of cesium-137 as a calibration standard can cause gross gamma measurements to overestimate the actual activity in the sample. At the same time, sample preparation for the determination of gross beta activities causes large losses of radioiodine before the measurement step and the presence of solid material can cause a serious decrease in the beta counting efficiency. A combination of these errors could result in large discrepancies between the results obtained by the two measurement methods. Improved procedures are required to overcome these problems 7. Standardization of 56Co had been carried out using 4 pi beta-gamma coincidence methods International Nuclear Information System (INIS) Wardiyanto, Gatot; Pujadi 2000-01-01 Standardization of exp.56 Co had been carried out using 4 pi beta-gamma coincidence methods. The radionuclide use for calibration of nuclear instruments on range of energy over 1500 keV. The exp.56 Co had been produced by irradiation of proton by using a cyclotron with 15 MeV of energy and 300 mb of cross-section to natural iron target (99,5% of purity) at the Institute for Nuclear Study, University of Tokyo. Source preparation had been done by gravimetry method after the irradiated source was dissolved in 8N HCI solution. The disintegration rate had been measured using 4 pi beta-gamma coincidence apparatus, where the gamm gets sets on 511 and 847 keV gamma-rays. The result measurement is fairly good with the specific activity is 3078 n 15 Bq/mg 8. Change in the aldolase activity in rats' hearts after irradiation with. gamma. and. beta. rays Energy Technology Data Exchange (ETDEWEB) Kukulyanskaya, M F; Borodina, G N 1973-01-01 The activity of aldolase fructoso-1-phosphate (I) and aldolase fructoso-1, 6-diphosphate (II) has been studied at various periods after total ..gamma.. and ..beta.. irradiation of rats at a dose of 42 rads. It has been shown that after ..gamma.. irradiation the activity of I increases in the supernatant liquid of the heart muscle homogenate, but drops sharply in the nuclei. In total, the activity of the homogenate did not change. The activity of II dropped for seven days, and after 1 hour and 30 days it was above the normal level. After ..beta.. radiation the activity of II is slowed down after 1, 7, and 15 days. These changes occur in all subcellular fractions. The authors note that the changes in the activity of aldolases are more sharply demarcated after ..gamma.. irradiation and are more substantial for II. (JPRS) 9. Thermodynamics in Gliomas: Interactions between the Canonical WNT/Beta-Catenin Pathway and PPAR Gamma Directory of Open Access Journals (Sweden) Alexandre Vallée 2017-05-01 Full Text Available Gliomas cells are the site of numerous metabolic and thermodynamics abnormalities with an increasing entropy rate which is characteristic of irreversible processes driven by changes in Gibbs energy, heat production, intracellular acidity, membrane potential gradient, and ionic conductance. We focus our review on the opposing interactions observed in glioma between the canonical WNT/beta-catenin pathway and PPAR gamma and their metabolic and thermodynamic implications. In gliomas, WNT/beta-catenin pathway is upregulated while PPAR gamma is downregulated. Upregulation of WNT/beta-catenin signaling induces changes in key metabolic enzyme that modify their thermodynamics behavior. This leads to activation pyruvate dehydrogenase kinase 1(PDK-1 and monocarboxylate lactate transporter 1 (MCT-1. Consequently, phosphorylation of PDK-1 inhibits pyruvate dehydrogenase complex (PDH. Thus, a large part of pyruvate cannot be converted into acetyl-CoA in mitochondria and in TCA (tricarboxylic acid cycle. This leads to aerobic glycolysis despite the availability of oxygen, named Warburg effect. Cytoplasmic pyruvate is, in major part, converted into lactate. The WNT/beta-catenin pathway induces also the transcription of genes involved in cell proliferation, cell invasiveness, nucleotide synthesis, tumor growth, and angiogenesis, such as c-Myc, cyclin D1, PDK. In addition, in gliomas cells, PPAR gamma is downregulated, leading to a decrease in insulin sensitivity and an increase in neuroinflammation. Moreover, PPAR gamma contributes to regulate some key circadian genes. Abnormalities in the regulation of circadian rhythms and dysregulation in circadian clock genes are observed in gliomas. Circadian rhythms are dissipative structures, which play a key role in far-from-equilibrium thermodynamics through their interactions with WNT/beta-catenin pathway and PPAR gamma. In gliomas, metabolism, thermodynamics, and circadian rhythms are tightly interrelated. 10. Counting efficiency for radionuclides decaying by beta and gamma-ray emission; Calculo de la eficiencia de recuento de nucleidos que experimentan desintegracion beta y desexcitacion gamma simple Energy Technology Data Exchange (ETDEWEB) Grau, A.; Garcia-Torano, E. 1988-07-01 In this paper, counting efficiency vs figure of merit for beta and gamma-ray emitters has been computed. It is assumed that the decay scheme has only a gamma level and the beta-ray emission may be coincident with the gamma-rays or the internal-conversion electrons. The radionuclides tabulated are: 20 {sub 0}, 20{sub p}, 28{sub A}l, 35{sub p}, 41{sub A}r, 42{sub K}, 47{sub S}e, 62{sub F}e, 66{sub C}u, 81{sub G}e, 86{sub B}b, 108{sub R}u, 112{sub p}d, 121{sub S}n(Ni), 122{sub I}n, 129{sub I}, 141{sub C}e 171{sub T}m, 194{sub O}s, 2O3{sub H}g, 205{sub H}g, 210{sub p}b, 225{sub R}a, 142{sub p}r, 151{sub S}m, 244{sub A}m(m). It has been assumed that the liquid is a toluene based scintillator solution in standard glass vials containing 10 cm''3. (Author) 8 refs. 11. Simultaneous and separate, low background counting of beta rays and gamma rays using the phoswich principle International Nuclear Information System (INIS) Mayhugh, M.R.; Utts, B.K.; Shoffner, B.M. 1978-01-01 A phoswich constructed using thin calcium fluoride optically coupled to a thicker sodium iodide crystal and operated with pulse shape analysis equipment can be used as an efficient low background counting assembly. Low background in the beta ray counting channel is achieved by judicious choice of pure materials in the assembly and by operating the analysis equipment so as to reject background events which occur simultaneously in the sodium iodide crystal. Careful survey of construction materials and methods has resulted in reducing beta ray counting background to 0.6 c/min for a 2-inch diameter assembly. The radioactivity of typical building materials will be discussed. A pulse shape analyzer has been constructed which provides separately adjusted time windows and separate output information for the beta ray and gamma ray channels. The dual channel capability combined with the low beta ray background reduces the sample counting time significantly for typical laboratory samples. (author) 12. Procedure for the elaboration of extended sources beta and/or gamma emitting International Nuclear Information System (INIS) Tejera R, A.; Cortes P, A.; Becerril V, A. 1991-12-01 In the laboratory of radioactive standards they have been come manufacturing punctual sources gauged gamma emitting during several years. Before the demand of extended radioactive homogeneous sources of beta particles emitting, in particular with nuclides that are simultaneously gamma and beta emitting, it was designed a procedure for it elaboration based on the one that we use at the moment for the elaboration of the punctual gamma sources. This procedure consists on the integration of a compact group of this type of sources on a single extended support, sealed one of its faces with a film of transparent material in satisfactory grade to the beta particles. In this work this procedure is described and it is applied in the elaboration of two sources that its were requested by the Laguna Verde Central (CFE), one with area of 20 cm 2 and the other one of 100 cm 2 . The homogeneity, measure as the dispersion of the activities of the aliquot ones distributed in the active surfaces was inside 2%. The percentage of attenuation of the beta particles was also measured by the film (window) with the one that the sources were sealed. (Author) 13. Beta, but not gamma, band oscillations index visual form-motion integration. Directory of Open Access Journals (Sweden) Charles Aissani Full Text Available Electrophysiological oscillations in different frequency bands co-occur with perceptual, motor and cognitive processes but their function and respective contributions to these processes need further investigations. Here, we recorded MEG signals and seek for percept related modulations of alpha, beta and gamma band activity during a perceptual form/motion integration task. Participants reported their bound or unbound perception of ambiguously moving displays that could either be seen as a whole square-like shape moving along a Lissajou's figure (bound percept or as pairs of bars oscillating independently along cardinal axes (unbound percept. We found that beta (15-25 Hz, but not gamma (55-85 Hz oscillations, index perceptual states at the individual and group level. The gamma band activity found in the occipital lobe, although significantly higher during visual stimulation than during base line, is similar in all perceptual states. Similarly, decreased alpha activity during visual stimulation is not different for the different percepts. Trial-by-trial classification of perceptual reports based on beta band oscillations was significant in most observers, further supporting the view that modulation of beta power reliably index perceptual integration of form/motion stimuli, even at the individual level. 14. Beta and gamma oscillatory activities associated with olfactory memory tasks: different rhythms for different functional networks? Science.gov (United States) Martin, Claire; Ravel, Nadine 2014-01-01 Olfactory processing in behaving animals, even at early stages, is inextricable from top down influences associated with odor perception. The anatomy of the olfactory network (olfactory bulb, piriform, and entorhinal cortices) and its unique direct access to the limbic system makes it particularly attractive to study how sensory processing could be modulated by learning and memory. Moreover, olfactory structures have been early reported to exhibit oscillatory population activities easy to capture through local field potential recordings. An attractive hypothesis is that neuronal oscillations would serve to "bind" distant structures to reach a unified and coherent perception. In relation to this hypothesis, we will assess the functional relevance of different types of oscillatory activity observed in the olfactory system of behaving animals. This review will focus primarily on two types of oscillatory activities: beta (15-40 Hz) and gamma (60-100 Hz). While gamma oscillations are dominant in the olfactory system in the absence of odorant, both beta and gamma rhythms have been reported to be modulated depending on the nature of the olfactory task. Studies from the authors of the present review and other groups brought evidence for a link between these oscillations and behavioral changes induced by olfactory learning. However, differences in studies led to divergent interpretations concerning the respective role of these oscillations in olfactory processing. Based on a critical reexamination of those data, we propose hypotheses on the functional involvement of beta and gamma oscillations for odor perception and memory. 15. Beta and gamma oscillatory activities associated with olfactory memory tasks: Different rhythms for different functional networks? Directory of Open Access Journals (Sweden) Claire eMartin 2014-06-01 Full Text Available Olfactory processing in behaving animals, even at early stages, is inextricable from top down influences associated with odor perception. The anatomy of the olfactory network (olfactory bulb, piriform and entorhinal cortices and its unique direct access to the limbic system makes it particularly attractive to study how sensory processing could be modulated by learning and memory. Moreover, olfactory structures have been early reported to exhibit oscillatory population activities easy to capture through local field potential recordings. An attractive hypothesis is that neuronal oscillations would serve to ‘bind’ distant structures to reach a unified and coherent perception. In relation to this hypothesis, we will assess the functional relevance of different types of oscillatory activity observed in the olfactory system of behaving animals. This review will focus primarily on two types of oscillatory activities: beta (15-40 Hz and gamma (60-100 Hz. While gamma oscillations are dominant in the olfactory system in the absence of odorant, both beta and gamma rhythms have been reported to be modulated depending on the nature of the olfactory task. Studies from the authors of the present review and other groups brought evidence for a link between these oscillations and behavioral changes induced by olfactory learning. However, differences in studies led to divergent interpretations concerning the respective role of these oscillations in olfactory processing. Based on a critical reexamination of those data, we propose hypotheses on the functional involvement of beta and gamma oscillations for odor perception and memory. 16. Effects of beta/gamma radiation on nuclear waste glasses International Nuclear Information System (INIS) Weber, W.J. 1997-01-01 A key challenge in the disposal of high-level nuclear waste (HLW) in glass waste forms is the development of models of long-term performance based on sound scientific understanding of relevant phenomena. Beta decay of fission products is one source of radiation that can impact the performance of HLW glasses through the interactions of the emitted β-particles and g-rays with the atoms in the glass by ionization processes. Fused silica, alkali silicate glasses, alkali borosilicate glasses, and nuclear waste glasses are all susceptible to radiation effects from ionization. In simple glasses, defects (e.g., non-bridging oxygen and interstitial molecular oxygen) are observed experimentally. In more complex glasses, including nuclear waste glasses, similar defects are expected, and changes in microstructure, such as the formation of bubbles, have been reported. The current state of knowledge regarding the effects of β/γ radiation on the properties and microstructure of nuclear waste glasses are reviewed. (author) 17. A new, passive dosemeter for gamma, beta and neutron radiations Energy Technology Data Exchange (ETDEWEB) Jones, L A; Stokes, R P, E-mail: rpstokes@dstl.gov.uk [Defence Science and Technology Laboratory, Environmental Sciences Department, Alverstoke, Gosport, Hants, PO12 2DL (United Kingdom) 2011-03-01 The Defence Science and Technology Laboratory (Dstl) provides personal radiation dosimetry to the UK Ministry of Defence. Dstl has recently developed a dosemeter that is based on a combination of thermoluminescent and etched-track detectors. The Dstl Combined Dosemeter is capable of assessing doses due to photons, beta particles and neutrons. This paper presents the laboratory type testing results for the Combined Dosemeter, and also describes the procedure for calibrating the dosemeter for use in workplace neutron fields. The Combined Dosemeter meets the type test requirements that are relevant to its intended applications, and gives neutron doses that are within 50% of the true dose in the workplaces in which it is used, even when the wearer has the potential to be exposed to a variety of neutron spectra (e.g. on board nuclear-powered submarines). 18. A new, passive dosemeter for gamma, beta and neutron radiations International Nuclear Information System (INIS) Jones, L A; Stokes, R P 2011-01-01 The Defence Science and Technology Laboratory (Dstl) provides personal radiation dosimetry to the UK Ministry of Defence. Dstl has recently developed a dosemeter that is based on a combination of thermoluminescent and etched-track detectors. The Dstl Combined Dosemeter is capable of assessing doses due to photons, beta particles and neutrons. This paper presents the laboratory type testing results for the Combined Dosemeter, and also describes the procedure for calibrating the dosemeter for use in workplace neutron fields. The Combined Dosemeter meets the type test requirements that are relevant to its intended applications, and gives neutron doses that are within 50% of the true dose in the workplaces in which it is used, even when the wearer has the potential to be exposed to a variety of neutron spectra (e.g. on board nuclear-powered submarines). 19. New detection modules for gamma, beta and X-ray cameras International Nuclear Information System (INIS) Azman, S.; Bolle, E.; Dang, K.Q.; Dang, W.; Dietzel, K.I.; Froberg, T.; Gaarder, P.E.; Gjaerum, J.A.; Haugen, S.H.; Hellum, G.; Henriksen, J.R.; Johanson, T.M.; Kobbevik, A.; Maehlum, G.; Meier, D.; Mikkelsen, S.; Ninive, I.; Oya, P.; Pavlov, N.; Pettersen, D.M.; Sundal, B.M.; Talebi, J.; Yoshioka, K. 2003-01-01 Full text: Ideas ASA is developing new detection modules for gamma, beta and X-ray cameras. Recent developments focus on modules using various semi-conductor materials (CZT, HgI, Si). The development includes ASIC design, detector module development, and implementation in camera heads. In this presentation we describe the characteristics of important ASICs and its properties in terms of electronic noise, and the modes for measuring signals (switched current modes, sparsified modes, self triggered modes). The ASICs are specific for detectors and applications. We describe recent developments using various semi - conductor materials. We describe important design aspects for medical applications and in life science (SPECT, beta, X-ray cameras) 20. Rat beta-LPH, gamma-LPH and beta-endorphin biosynthesized by isolated cells of pars intermedia and pars distalis International Nuclear Information System (INIS) Gianoulakis, C.; Seidah, N.G.; Routhier, R.; Chretien, M. 1980-01-01 Rats pars intermedia cells were incubated for 3 h with the following amino-acids: a) 35 S-methionine and 3 H-phenylalamine; b) 3 H-valine; and c) 3 H-valine and 3 H-lysine. Radioactive gamma-lipotropin, beta-lipotropin and beta-endorphin were purified on carboxy- methyl-cellulose and characterized by polyacrylamide disc gel electrophoresis af pH 4.5, molecular weight estimation and microsequencing. Rat gamma-lipotropin was shown to differ slightly from ovine gamma-lipotropin in its NH 2 -terminal amino acid sequence, in containing no methionine and having phenylalanine at position 6, valine at positions 13 and 27, and lysine at position 20. The same variations were observed in the sequence of rat beta-lipotropin, while rat beta-endorphin was shown to be identical to the ovine beta-endorphin. Following a 3-h pulse of rat pars distalis, the cells were extracted with care to avoid beta-lipotropin degradation by proteolytic enzymes. A peptide was purified and identified to be rat beta-endorphin, thus demonstrating that beta-endorphin is biosynthesized in pars distalis and is not an extraction artifact. (author) 1. Proceedings of the International Symposium Advances in alpha, Beta- and Gamma-Ray spectrometry International Nuclear Information System (INIS) 1997-01-01 The International Committee for Radionuclide Metrology (ICRM) is an association of radionuclide metrology laboratories whose membership is composed of delegates of these laboratories together with other scientists actively engaged in the study and applications of radioactivity. The scientific activities are carried out in the frame of six Working Groups. Two of them, the Alpha-Particle Spectrometry and the Gamma-and Beta-ray Spectrometry Working Groups held a common workshop in Pushkin, St. Petersburg, 18 to 20 September 1996, under the title Advances in Alpha-Beta-and Gamma-Ray Sepectrometry, at the kind invitation of the D.I. Mendeleyev Institute for Metrology. More than 30 people from 14 laboratories attended the meeting, and nineteen oral communications were presented, from which twelve were retained for publication an are included in these proceedings. (Author) 2. Solute transport and the prediction of breakaway oxidation in gamma + beta Ni-Cr-Al alloys Science.gov (United States) Nesbitt, J. A.; Heckel, R. W. 1984-01-01 The Al transport and the condition leading to breakaway oxidation during the cyclic oxidation of gamma + beta NiCrAl alloys have been studied. The Al concentration/distance profiles were measured after various cyclic oxidation exposures at 1200 C. It was observed that cyclic oxidation results in a decreasing Al concentration at the oxide/metal interface, maintaining a constant flux of Al to the Al2O3 scale. It was also observed that breakaway oxidation occurs when the Al concentration at the oxide/metal interface approaches zero. A numerical model was developed to simulate the diffusional transport of Al and to predict breakaway oxidation in gamma + beta NiCrAl alloys undergoing cyclic oxidation. In a comparison of two alloys with similar oxide spalling characteristics, the numerical model was shown to predict correctly the onset of breakaway oxidation in the higher Al-content alloy. 3. Scintillation characteristics of phosphich-detector for detection of beta- and gamma-radiations CERN Document Server Ananenko, A A; Gavrilyuk, V 2002-01-01 The results of the study on the influence of individual peculiarities of the compound scintillation detector structure on the value and stability of the light yield by the gamma- and beta-radiation combined registration are presented. The phosphich detector is manufactured from the sodium iodide monocrystal, activated by thallium, and the scintillation plastic on the polystyrol basis. The comparison of the experimental results with the mathematical modeling data revealed certain regularities of the process of forming the phosphich detector light signal. The recommendations are worked out by means whereof the following characteristics of the scintillation unit: the light yield and its stability, amplitude resolution and the peak-to-valley ratio by the gamma- and beta-radiation registration were improved 4. An analytical model to calculate absorbed fractions for internal dosimetry with alpha, beta and gamma emitters OpenAIRE Amato, Ernesto; Italiano, Antonio; Baldari, Sergio 2014-01-01 We developed a general model for the calculation of absorbed fractions in ellipsoidal volumes of soft tissue uniformly filled with alpha, beta and gamma emitting radionuclides. The approach exploited Monte Carlo simulations with the Geant4 code to determine absorbed fractions in ellipsoids characterized by a wide range of dimensions and ellipticities, for monoenergetic emissions of each radiation type. The so-obtained absorbed fractions were put in an analytical relationship with the 'general... 5. Patterns of alpha, beta and gamma diversity of the herpetofauna in Mexico’s Pacific lowlands and adjacent interior valleys Directory of Open Access Journals (Sweden) García, A. 2007-12-01 Full Text Available The latitudinal distribution patterns of alpha, beta and gamma diversity of reptiles, amphibians and herpetofauna were analyzed using individual binary models of potential distribution for 301 species predicted by ecological modelling for a grid of 9,932 quadrants of ~25 km2 each. We arranged quadrants in 312 latitudinal bands in which alpha, beta and gamma values were determined. Latitudinal trends of all scales of diversity were similar in all groups. Alpha and gamma responded inversely to latitude whereas beta showed a high latitudinal fluctuation due to the high number of endemic species. Alpha and gamma showed a strong correlation in all groups. Beta diversity is an important component of the herpetofauna distribution patterns as a continuous source of species diversity throughout the region. 6. Gamma and Beta Oscillations in Human MEG Encode the Contents of Vibrotactile Working Memory Directory of Open Access Journals (Sweden) Alexander H. von Lautz 2017-12-01 Full Text Available Ample evidence suggests that oscillations in the beta band represent quantitative information about somatosensory features during stimulus retention. Visual and auditory working memory (WM research, on the other hand, has indicated a predominant role of gamma oscillations for active WM processing. Here we reconciled these findings by recording whole-head magnetoencephalography during a vibrotactile frequency comparison task. A Braille stimulator presented healthy subjects with a vibration to the left fingertip that was retained in WM for comparison with a second stimulus presented after a short delay. During this retention interval spectral power in the beta band from the right intraparietal sulcus and inferior frontal gyrus (IFG monotonically increased with the to-be-remembered vibrotactile frequency. In contrast, induced gamma power showed the inverse of this pattern and decreased with higher stimulus frequency in the right IFG. Together, these results expand the previously established role of beta oscillations for somatosensory WM to the gamma band and give further evidence that quantitative information may be processed in a fronto-parietal network. 7. Monte Carlo simulation of {beta}-{gamma} coincidence system using plastic scintillators in 4{pi} geometry Energy Technology Data Exchange (ETDEWEB) Dias, M.S. [Instituto de Pesquisas Energeticas e Nucleares: IPEN-CNEN/SP, Av. Prof. Lineu Prestes 2242, 05508-000 Sao Paulo, SP (Brazil)], E-mail: msdias@ipen.br; Piuvezam-Filho, H. [Instituto de Pesquisas Energeticas e Nucleares: IPEN-CNEN/SP, Av. Prof. Lineu Prestes 2242, 05508-000 Sao Paulo, SP (Brazil); Baccarelli, A.M. [Departamento de Fisica-PUC/SP-Rua Marques de Paranagua 111, 01303-050 Sao Paulo, SP (Brazil); Takeda, M.N. [Universidade Santo Amaro, UNISA-Rua Prof. Eneas da Siqueira Neto 340, 04829-300 Sao Paulo, SP (Brazil); Koskinas, M.F. [Instituto de Pesquisas Energeticas e Nucleares: IPEN-CNEN/SP, Av. Prof. Lineu Prestes 2242, 05508-000 Sao Paulo, SP (Brazil) 2007-09-21 A modified version of a Monte Carlo code called Esquema, developed at the Nuclear Metrology Laboratory in IPEN, Sao Paulo, Brazil, has been applied for simulating a 4{pi}{beta}(PS)-{gamma} coincidence system designed for primary radionuclide standardisation. This system consists of a plastic scintillator in 4{pi} geometry, for alpha or electron detection, coupled to a NaI(Tl) counter for gamma-ray detection. The response curves for monoenergetic electrons and photons have been calculated previously by Penelope code and applied as input data to code Esquema. The latter code simulates all the disintegration processes, from the precursor nucleus to the ground state of the daughter radionuclide. As a result, the curve between the observed disintegration rate as a function of the beta efficiency parameter can be simulated. A least-squares fit between the experimental activity values and the Monte Carlo calculation provided the actual radioactive source activity, without need of conventional extrapolation procedures. Application of this methodology to {sup 60}Co and {sup 133}Ba radioactive sources is presented and showed results in good agreement with a conventional proportional counter 4{pi}{beta}(PC)-{gamma} coincidence system. 8. Screening procedures for alpha, beta and gamma emitting radionuclides in urine International Nuclear Information System (INIS) Kramer, G.H.; Gardner, S.E.; Johnson, J.R. 1983-08-01 The gross actinide and beta screening methods currently used by the Bioassay Laboratory at Chalk River Nuclear Laboratories have been documented and tested. The gross gamma method has also been documented. The gross actinide method was tested with Th-nat, Pu-239, Np-237, Am-241 and Cm-244 and the average percent recoveries were 90, 99, 45, 72 and 78, respectively. The gross beta method was tested with Sr-90/Y-90, Ce-144/Pr-144, Pm-147 and Ba-133 and the average percent recoveries were 78, 100, 46 and 46, respectively. Detection limits for the gross actinide (alpha) method are found to be about 0.4 mBq and about 39 mBq for the gross beta method 9. Period concatenation underlies interactions between gamma and beta rhythms in neocortex Directory of Open Access Journals (Sweden) Anita K Roopun 2008-04-01 Full Text Available The neocortex generates rhythmic electrical activity over a frequency range covering many decades. Specific cognitive and motor states are associated with oscillations in discrete frequency bands within this range, but it is not known whether interactions and transitions between distinct frequencies are of functional importance. When coexpressed rhythms have frequencies that differ by a factor of two or more interactions can be seen in terms of phase synchronization. Larger frequency differences can result in interactions in the form of nesting of faster frequencies within slower ones by a process of amplitude modulation. It is not known how coexpressed rhythms, whose frequencies differ by less than a factor of two may interact. Here we show that two frequencies (gamma – 40 Hz and beta2 – 25 Hz, coexpressed in superficial and deep cortical laminae with low temporal interaction, can combine to generate a third frequency (beta1 – 15 Hz showing strong temporal interaction. The process occurs via period concatenation, with basic rhythm-generating microcircuits underlying gamma and beta2 rhythms forming the building blocks of the beta1 rhythm by a process of addition. The mean ratio of adjacent frequency components was a constant – approximately the golden mean – which served to both minimize temporal interactions, and permit multiple transitions, between frequencies. The resulting temporal landscape may provide a framework for multiplexing – parallel information processing on multiple temporal scales. 10. Response-surface models for deterministic effects of localized irradiation of the skin by discrete {beta}/{gamma} -emitting sources Energy Technology Data Exchange (ETDEWEB) Scott, B.R. 1995-12-01 Individuals who work at nuclear reactor facilities can be at risk for deterministic effects in the skin from exposure to discrete {Beta}- and {gamma}-emitting ({Beta}{gamma}E) sources (e.g., {Beta}{gamma}E hot particles) on the skin or clothing. Deterministic effects are non-cancer effects that have a threshold and increase in severity as dose increases (e.g., ulcer in skin). Hot {Beta}{gamma}E particles are {sup 60}Co- or nuclear fuel-derived particles with diameters > 10 {mu}m and < 3 mm and contain at least 3.7 kBq (0.1 {mu}Ci) of radioactivity. For such {Beta}{gamma}E sources on the skin, it is the beta component of the dose that is most important. To develop exposure limitation systems that adequately control exposure of workers to discrete {Beta}{gamma}E sources, models are needed for systems that adequately control exposure of workers to discrete {Beta}{gamma}E sources, models are needed for evaluating the risk of deterministic effects of localized {Beta} irradiation of the skin. The purpose of this study was to develop dose-rate and irradiated-area dependent, response-surface models for evaluating risks of significant deterministic effects of localized irradiation of the skin by discrete {Beta}{gamma}E sources and to use modeling results to recommend approaches to limiting occupational exposure to such sources. The significance of the research results as follows: (1) response-surface models are now available for evaluating the risk of specific deterministic effects of localized irradiation of the skin; (2) modeling results have been used to recommend approaches to limiting occupational exposure of workers to {Beta} radiation from {Beta}{gamma}E sources on the skin or on clothing; and (3) the generic irradiated-volume, weighting-factor approach to limiting exposure can be applied to other organs including the eye, the ear, and organs of the respiratory or gastrointestinal tract and can be used for both deterministic and stochastic effects. 11.$\\beta$3$p$-spectroscopy and proton-$\\gamma$width determination in the decay of$^{31}$Ar CERN Multimedia We propose to perform a detailed study of the$\\beta$-decay of the dripline nucleus$^{31}$Ar. This will allow a detailed study of the$\\beta$-delayed 3$p$-decay as well as provide important information on the resonances of$^{30}$S and$^{29}$P, in particular the ratio between the$p$- and$\\gamma- partial widths relevant for astrophysics. 12. Beta-glucan ameliorates gamma-rays induced oxidative injury in male Swiss albino rats International Nuclear Information System (INIS) Salama, S.F. 2011-01-01 1,3-beta-D-Glucan is a natural polysaccharide derived from the cell walls of bakers yeast Saccharomyces cerevsiae with immunoenhancing and potent antioxidant effects. This study investigated the pathways through which beta-glucan gavage treatment (50mg/kg) exerts its effect on radiation-induced oxidative damage in male rats. Beta-glucan was given orally to male rats; 3 hours post gamma-irradiation at dose 5Gy, for 10 and 20 days post-irradiation level were assayed, being remarkable indicators in cell oxidative stress. Results pointed out that irradiation at 5Gy significantly depressed all blood parameters, such as erythrocytes count (RBCs), hemoglobin content (Hb), hematocrit value (Hct), total leucocytes count and absolute lymphocytes and neutrophils counts, blood glutathione (GSH) level and conversely elevated level of serum ascorbyl radical (AsR), product of lipid peroxidation (MDA melanodialdehyde), triglycerides and cholesterol. Total leucocytes count and absolute lymphocytes and neutrophils counts, RBCs, Hb, Hct, blood GSH and serum MDA of irradiated animals receiving beta-glucan administration were exhibited significant differences compared to the irradiated group. Marrow count and the percentage of viability and spleenocytes viability were also significantly decreased. Beta-glucan treatment accelerates recovery of cell damage induced by ionizing irradiation through its potential immune-enhancing activity and free radical scavenging ability that is partially mediated through stimulation of immunohaematological system thus could play a role in regulating irradiation complications 13. Interactions Between the Canonical WNT/Beta-Catenin Pathway and PPAR Gamma on Neuroinflammation, Demyelination, and Remyelination in Multiple Sclerosis. Science.gov (United States) Vallée, Alexandre; Vallée, Jean-Noël; Guillevin, Rémy; Lecarpentier, Yves 2018-05-01 Multiple sclerosis (MS) is marked by neuroinflammation and demyelination with loss of oligodendrocytes in the central nervous system. The immune response is regulated by WNT/beta-catenin pathway in MS. Activated NF-kappaB, a major effector of neuroinflammation, and upregulated canonical WNT/beta-catenin pathway positively regulate each other. Demyelinating events present an upregulation of WNT/beta-catenin pathway, whereas proper myelinating phases show a downregulation of WNT/beta-catenin pathway essential for the promotion of oligodendrocytes precursors cells proliferation and differentiation. The activation of WNT/beta-catenin pathway results in differentiation failure and impairment in remyelination. However, PI3K/Akt pathway and TCF7L2, two downstream targets of WNT/beta-catenin pathway, are upregulated and promote proper remyelination. The interactions of these signaling pathways remain unclear. PPAR gamma activation can inhibit NF-kappaB, and can also downregulate the WNT/beta-catenin pathway. PPAR gamma and canonical WNT/beta-catenin pathway act in an opposite manner. PPAR gamma agonists appear as a promising treatment for the inhibition of demyelination and the promotion of proper remyelination through the control of both NF-kappaB activity and canonical WNT/beta-catenin pathway. 14. Maternal and cord plasma concentrations of beta-lipotrophin, beta-endorphin and gamma-lipotrophin at delivery; effect of analgesia. Science.gov (United States) Browning, A J; Butt, W R; Lynch, S S; Shakespear, R A; Crawford, J S 1983-12-01 Maternal venous plasma concentrations of beta-LPH, beta-EP and gamma-LPH were compared in (i) patients undergoing vaginal delivery, 11 with an epidural block and 13 with pethidine and nitrous oxide or no analgesics; (ii) patients delivered by caesarean section, 7 under epidural block and 8 under general anaesthesia. Patients delivered by either method under epidural block had significantly lower levels of all three peptides than those receiving no epidural. There were significant negative correlations between umbilical vein beta-LPH, beta-EP and gamma-LPH concentrations and umbilical artery pH and positive correlations between beta-LPH and beta-EP but not gamma-LPH and cord PCO2 in 29 patients. There was no relation between cord levels of any of the three peptides and the method of analgesia or the route of delivery. Although concentrations of all three peptides were closely correlated to one another in either maternal or cord plasma, there was no relationship between maternal and fetal levels. 15. An analytical model to calculate absorbed fractions for internal dosimetry with alpha, beta and gamma emitters Directory of Open Access Journals (Sweden) Ernesto Amato 2014-03-01 Full Text Available We developed a general model for the calculation of absorbed fractions in ellipsoidal volumes of soft tissue uniformly filled with alpha, beta and gamma emitting radionuclides. The approach exploited Monte Carlo simulations with the Geant4 code to determine absorbed fractions in ellipsoids characterized by a wide range of dimensions and ellipticities, for monoenergetic emissions of each radiation type. The so-obtained absorbed fractions were put in an analytical relationship with the 'generalized radius', calculated as 3V/S, where V is the ellipsoid volume and S its surface. Radiation-specific parametric functions were obtained in order to calculate the absorbed fraction of a given radiation in a generic ellipsoidal volume. The dose from a generic radionuclide can be calculated through a process of summation and integration over the whole radionuclide emission spectrum, profitably implemented in an electronic spreadsheet. We compared the results of our analytical calculation approach with those obtained from the OLINDA/EXM computer software, finding a good agreement in a wide range of sphere radii, for the high-energy pure beta emitter 90Y, the commonly employed beta-gamma emitter 131I, and the pure alpha emitter 213Po. The generality of our approach makes it useful an easy to implement in clinical dosimetry calculations as well as in radiation safety estimations when doses from internal radionuclide uptake are to be taken into account. 16. Beta-gamma spectroscopy for double beta decays and Lepton number conservation International Nuclear Information System (INIS) Ejiri, H.; Takahashi, N.; Shibata, T.; Nagai, Y.; Okada, K.; Kamikubota, N.; Watanabe, T. 1984-01-01 In this paper neutrino-less double β decays (Oν ββ) of /sup 76/Ge were studied by means of the newly developed ELEGANTS (Electron gamma-ray neutrino spectrometer). It consists of a 171 cc pure Ge detector surrounded bu a big 4π-NaI detector, and active and inactive filters. Measurement of both the electron signal from the Ge detector and γ-ray signals from the 4π-NaI detector made it possible to select the true double decay events from background events due to the other radio-active isotopes and cosmic rays. The ELEGANTS showed the highest sensitivity for detecting the neutrino-less double β decay. The preliminary data obtained so far give a lower limit of the half life T/sub 1/2/≥2.2 10/sup 22/y for the O/sup +/→O/sup +/ Oν ββ decay and T/sub 1/2/ ≥1.5.10/sup 22/y for the O/sup +/→2/sup +/ Oν ββ decay of /sup 76/Ge 17. TL glow curve analysis of UV, beta and gamma induced limestone collected from Amarnath holy cave Directory of Open Access Journals (Sweden) Vikas Dubey 2015-01-01 Full Text Available The paper reports themoluminescence glow curve analysis of UV (ultraviolet, β (beta and γ (gamma induced limestone collected from Amarnath holy cave. The collected natural sample was characterized by X-ray diffraction (XRD technique and crystallite size calculated by Scherer's formula. Surface morphology and particle size was calculated by transmission electron microscopy (TEM study. Effect of annealing temperature on collected lime stone examined by TL glow curve study. The limestone was irradiated by UV radiation (254 nm source and the TL glow curve recorded for different UV exposure time. For beta irradiation Sr90 source was used and is shows intense peak at 256 °C with a shoulder peak at higher temperature range. For gamma radiation Co60 source and TL glow curve recorded for different doses of gamma. The kinetic parameters calculation was performed for different glow curve by computerized glow curve deconvolution (CGCD technique. The chemical composition of natural limestone was analyzed by energy dispersive X-ray spectroscopy (EDXS. 18. Hard beta and gamma emissions of 124I. Impact on occupational dose in PET/CT. Science.gov (United States) Kemerink, G J; Franssen, R; Visser, M G W; Urbach, C J A; Halders, S G E A; Frantzen, M J; Brans, B; Teule, G J J; Mottaghy, F M 2011-01-01 The hard beta and gamma radiation of 124I can cause high doses to PET/CT workers. In this study we tried to quantify this occupational exposure and to optimize radioprotection. Thin MCP-Ns thermoluminescent dosimeters suitable for measuring beta and gamma radiation were used for extremity dosimetry, active personal dosimeters for whole-body dosimetry. Extremity doses were determined during dispensing of 124I and oral administration of the activity to the patient, the body dose during all phases of the PET/CT procedure. In addition, dose rates of vials and syringes as used in clinical practice were measured. The procedure for dispensing 124I was optimized using newly developed shielding. Skin dose rates up to 100 mSv/min were measured when in contact with the manufacturer's vial containing 370 MBq of 124I. For an unshielded 5 ml syringe the positron skin dose was about seven times the gamma dose. Before optimization of the preparation of 124I, using an already reasonably safe technique, the highest mean skin dose caused by handling 370 MBq was 1.9 mSv (max. 4.4 mSv). After optimization the skin dose was below 0.2 mSv. The highly energetic positrons emitted by 124I can cause high skin doses if radioprotection is poor. Under optimized conditions occupational doses are acceptable. Education of workers is of paramount importance. 19. Study of the Nuclear Structure of 39P Using Beta-Delayed Gamma Spectroscopy Science.gov (United States) Abromeit, Brittany; NSCL Experiment E14063 Team Team 2016-03-01 Investigation of nuclei with neutron and proton imbalance is at the forefront of nuclear physics research today. This is driven by the fact that the structure in these regimes may vary with that seen near the valley of stability. With eight neutrons more than the stable isotope of phosphorous, 39P is a neutron-rich exotic nucleus that has very limited information on it: previous studies of 39P produce only three known energy levels and gamma rays. The fragmentation of a 48Ca primary beam on a 564mg/cm2 thick Be target at the National Superconducting Cyclotron Laboratory (NSCL) was used to produce exotic 39Si. Using the NSCL Beta Counting System (BCS), consisting of a thick planner germanium double-sided strip detector (GeDSSD) and 16 High-purity germanium detectors in an array, SeGA, the beta-gamma coincidences from the decay of 39Si to 39P were analyzed. The resulting level scheme of 39P, including over 12 new gamma rays and energy states, confirmation of the previously measured half-life, and first-time logft values will be presented. This work was supported by the NSF under Grant No. 1401574. 20. Effect of beta and gamma neurofeedback on memory and intelligence in the elderly. Science.gov (United States) Staufenbiel, S M; Brouwer, A-M; Keizer, A W; van Wouwe, N C 2014-01-01 Recent research showed a correlation between cognitive decline and a decrease of EEG gamma activity. In the present double-blind randomized control study, we investigated whether gamma and beta neurofeedback protocols, that have been shown to modulate performance on cognitive control and memory in young adults, also leads to increased brain activity and cognitive performance in elderly. Twenty older adults either performed eight 30-min gamma neurofeedback session or beta neurofeedback session within a period of 21 days. Cognitive performance was determined before and after the training through an IQ and memory task and we added a subjective well-being questionnaire. Both neurofeedback training protocols resulted in a significant increase of the brain activity within each training session, suggesting that the aging brain is still trainable. However, we found no effects on cognitive performance or transfer of the feedback beyond the trainings. We discuss several possible reasons for the lack of training on rest measurements and cognition and ways to improve the feedback protocols for future studies. Copyright © 2013 Elsevier B.V. All rights reserved. 1. Hand Monitor for Simultaneous Measurements of Alpha and Beta Contamination International Nuclear Information System (INIS) Andersson, I.Oe.; Braun, J.; Soederlund, B. 1960-11-01 An instrument is described which measures α and β contamination of the hands simultaneously. This has been achieved by using as detectors 8 flow counters paired in 4 units of two chambers, one unit for each side of the hand. The inner chamber of every unit (adjacent to the hands) delivers α-pulses, the outer chambers deliver β-pulses. When two finger contacts are pushed the detectors are closing around the hands and the measurement is started. Audible and visual warnings operate when the MPL is exceeded. Similar warnings ope.rate if hands are removed before the end of the counting period. The activity levels are logarithmically indicated on four pointer instruments, which are automatically zeroed when the next measurement is started. The instrument is now commercially available 2. Optimization of detector size and scan rate for beta/gamma material release surveys International Nuclear Information System (INIS) Bishop, R.V. 1993-01-01 DOE facilities are required to offer for sale to the public items of salvageable value when they are no longer required by the facilities. These items have to be surveyed to ensure radioactive contamination levels do not exceed the values listed in DOE Order 5400.5. Most facilities use portable contamination monitoring.equipment with probe areas between 20 and 100 cm 2 to check for fixed contamination. This procedure is very labor intensive and results in survey costs that often exceed the costs recovered from selling the items. A solution would be to use large area (> 100 cm 2 ) detectors to find and quantify contamination. Large area scintillation detectors that can be used for beta and alpha detection simultaneously are becoming available commercially. Combining these with a rate meter that can differentiate between alpha and beta events can result in a survey that takes considerably less time to do and will save a proportional amount of money in doing so. The use and limitations of this combination of detectors and rate meters will be discussed 3. Gamma irradiation versus microbial contamination of Thai medicinal herbs Directory of Open Access Journals (Sweden) Wannipa Phianphak 2007-03-01 Full Text Available Seventeen species of herbs established in Thai traditional remedies were microbially decontaminated by gamma-irradiation doses of 7.7 and 8.8 kGy. The herb samples were randomly collected four times from producers in Chiangmai during a 1-year period. These were tested, qualitatively and quantitatively, for total aerobic bacteria, Staphylococcus spp., Salmonella spp., coliform bacteria, and fungi before and after gamma treatment. No microorganisms were found after gamma treatment; and the color, aroma, and texture of the herbs remained normal. The applied dose of gamma irradiation was within the regulatory limits in Thailand (<10 kGy and the main export country (USA< 30 kGy. Gamma irradiation is an effective treatment for microbial decontamination of Thai export herbs. 4. Borehole Calibration Facilities to Support Gamma Logging for Hanford Subsurface Investigation and Contaminant Monitoring - 13516 International Nuclear Information System (INIS) McCain, R.G.; Henwood, P.D.; Pope, A.D.; Pearson, A.W. 2013-01-01 Repeated gamma logging in cased holes represents a cost-effective means to monitor gamma-emitting contamination in the deep vadose zone over time. Careful calibration and standardization of gamma log results are required to track changes and to compare results over time from different detectors and logging systems. This paper provides a summary description of Hanford facilities currently available for calibration of logging equipment. Ideally, all logging organizations conducting borehole gamma measurements at the Hanford Site will take advantage of these facilities to produce standardized and comparable results. (authors) 5. Borehole Calibration Facilities to Support Gamma Logging for Hanford Subsurface Investigation and Contaminant Monitoring - 13516 Energy Technology Data Exchange (ETDEWEB) McCain, R.G.; Henwood, P.D.; Pope, A.D.; Pearson, A.W. [S M Stoller Corporation, 2439 Robertson Drive, Richland, WA 99354 (United States) 2013-07-01 Repeated gamma logging in cased holes represents a cost-effective means to monitor gamma-emitting contamination in the deep vadose zone over time. Careful calibration and standardization of gamma log results are required to track changes and to compare results over time from different detectors and logging systems. This paper provides a summary description of Hanford facilities currently available for calibration of logging equipment. Ideally, all logging organizations conducting borehole gamma measurements at the Hanford Site will take advantage of these facilities to produce standardized and comparable results. (authors) 6. Reduction of beta-interference in gamma-spectrometric measurements of neutron-irradiated geological material International Nuclear Information System (INIS) Garmann, L.B. 1986-01-01 The analytical technique for INAA, when applied to geological materials, is improved by introducing an electromagnetic field between sample and detector. This field lowers the bremsstrahlung background intensity in the gamma-spectrum by reducing the number of beta-particles reaching the detector. Thus precision, accuracy and lower detection limit are improved. The technique was used on alkalisyenite and on meteoritic material, rocks containing high quantities of sodium and iron, respectively. After neutron irradiation, the induced nuclides sup(24)Na and sup(59)Fe are responsible for high bremsstrahlung interference, which under normal analyitical conditions would mask any x-ray or gamma-ray peaks of interest. The technique is easily applied to multielement analysis of geological and biological materials. It can be combined with sophisticated spectrum-treating techniques such as spectrum stripping and spectrum smoothing, or coincidence-anticoincidence circuits. (author) 7. Automatic analysis algorithm for radionuclide pulse-height data from beta-gamma coincidence systems International Nuclear Information System (INIS) Foltz Biegalski, K.M. 2001-01-01 There are two acceptable noble gas monitoring measurement modes for Comprehensive Nuclear-Test-Ban-Treaty (CTBT) verification purposes defined in CTBT/PC/II/WG.B/1. These include beta-gamma coincidence and high-resolution gamma-spectrometry. There are at present no commercial, off-the-shelf (COTS) applications for the analysis of β-γ coincidence data. Development of such software is in progress at the Prototype International Data Centre (PIDC) for eventual deployment at the International Data Centre (IDC). Flowcharts detailing the automatic analysis algorithm for β-γ coincidence data to be coded at the PIDC is included. The program is being written in C with Oracle databasing capabilities. (author) 8. On evaluated nuclear data for beta-delayed gamma rays following of special nuclear materials Energy Technology Data Exchange (ETDEWEB) Mencarini, Leonardo de H.; Caldeira, Alexandre D., E-mail: mencarini@ieav.cta.b, E-mail: alexdc@ieav.cta.b [Instituto de Estudos Avancados (IEAv/CTA), Sao Jose dos Campos, SP (Brazil) 2011-07-01 In this paper, a new type of information available in ENDF is discussed. During a consistency check of the evaluated nuclear data library ENDF/B-VII.0 performed at the Nuclear Data Subdivision of the Institute for Advanced Studies, the size of the files for some materials drew the attention of one of the authors. Almost 94 % of all available information for these special nuclear materials is used to represent the beta-delayed gamma rays following fission. This is the first time this information is included in an ENDF version. (author) 9. Thermoluminescent characterization of thin films of aluminium oxide submitted to beta and gamma radiation International Nuclear Information System (INIS) Villagran, E.; Escobar A, L.; Camps, E.; Gonzalez, P.R.; Martinez A, L. 2002-01-01 By mean of the laser ablation technique, thin films of aluminium oxide have been deposited on kapton substrates. These films present thermoluminescent response (Tl) when they are exposed to beta and gamma radiation. The brilliance curves show two peaks between 112 C and 180 C. A dose-response relationship study was realized and the Tl kinetic parameters were determined using the computerized deconvolution of the brilliance curve (CGCD). The thin films of aluminium oxide have potential applications as ultra.thin radiation dosemeters. (Author) 10. Comparison of new and existing algorithms for the analysis of 2D radioxenon beta gamma spectra International Nuclear Information System (INIS) Deshmukh, Nikhil; Prinke, Amanda; Miller, Brian; McIntyre, Justin 2017-01-01 The aim of this paper is to compare radioxenon beta-gamma analysis algorithms using simulated spectra with experimentally measured background, where the ground truth of the signal is known. We believe that this is among the largest efforts to date in terms of the number of synthetic spectra generated and number of algorithms compared using identical spectra. We generate an estimate for the minimum detectable counts for each isotope using each algorithm. The paper also points out a conceptual model to put the various algorithms into a continuum. Our results show that existing algorithms can be improved and some newer algorithms can be better than the ones currently used. (author) 11. On evaluated nuclear data for beta-delayed gamma rays following of special nuclear materials International Nuclear Information System (INIS) Mencarini, Leonardo de H.; Caldeira, Alexandre D. 2011-01-01 In this paper, a new type of information available in ENDF is discussed. During a consistency check of the evaluated nuclear data library ENDF/B-VII.0 performed at the Nuclear Data Subdivision of the Institute for Advanced Studies, the size of the files for some materials drew the attention of one of the authors. Almost 94 % of all available information for these special nuclear materials is used to represent the beta-delayed gamma rays following fission. This is the first time this information is included in an ENDF version. (author) 12. Microbial contamination and effects of combination treatments and gamma irradiation on reducing microbial contamination of dried cuttle fish International Nuclear Information System (INIS) Yen, B.T. 1989-01-01 Dried cuttle fish is one of the most valuable sea products but it rapidly becomes mouldy and spoiled. To solve this problem, the studies on microbial contamination and effects of combination treatments and gamma irradiation for dried cuttle fish have been caried out base on IAEA Research Contracts No 4397/AG and 4397/R1/AG 13. New miniaturized alpha/beta spectrometric system for the surface contamination monitoring and radon personal dosimeter International Nuclear Information System (INIS) Streil, T.; Oeser, V.; Holfeld, G. 1998-01-01 The heart of the new miniaturized alpha/beta spectroscopic system is a Smart Card MCA having a 12 bit resolution and a 32 bit memory for each channel with the size of a cheque card. The system consists of a single or up to 12 alpha spectrometers in a battery powered casing with connectors for direct detector/amplifier module plugging. Surface contamination in the order of 1 Bq/cm 2 of 239 Pu can be measured. (M.D.) 14. Measurement of the beta-gamma directional correlation of the transition 46Sc→46Ti International Nuclear Information System (INIS) Krexner, G. 1978-01-01 Measuring the forward - backward asymmetry of the direction of gamma quanta with respect to the direction of a preceding beta particle emission is one of the methods which have been developed over the past twenty years to investigate parity admixtures in nuclear states. Both theoretical calculations and experiments using this method yield very small values for the considered effect. Moreover the accuracy is limited for statistical reasons. Hence there exists a fundamental interest in proving the experimental arrangement to be free of systematic errors. The subject of this work is an experiment checking a six - detector apparatus which has been used to investigate the beta - gamma directional correlation in the decay 203 Hg→ 203 Tl. For the control measurement the transition 46 Sc→ 46 Ti was chosen. The asymmetry coefficient should yield zero and thus furnish evidence of the absence of systematic errors. The necessary 46 Sc source had to meet very restricting requirements. The feasibility of various methods for producing radioactive samples was reviewed; finally a specially designed high vacuum evaporation plant was constructed. The concept of this device and the preparation of the source are dealt with in detail. A preliminary result of the control experiment is given. However, at present a definite interpretation of the obtained values is not possible. (author) 15. Study of Optically Stimulated Luminescence of LiF:Mg,Ti for beta and gamma dosimetry International Nuclear Information System (INIS) Matsushima, Luciana C.; Veneziani, Glauco R.; Campos, Letícia L. 2013-01-01 Modern advances in radiation medicine – radiodiagnosis, radiotherapy and interventional radiography – each present dosimetry challenges for the medical physicist that did not exist previously. In all of these areas a constant balance has to be made between the treatment necessary to destroy the tumor and the unnecessary exposure of healthy tissue. Innovative applications of OSL dosimetry are now appearing in each of these areas to help the medical physicist and oncologist design the most effective, and least deleterious, treatment for their patients. High sensitivity, precise delivery of light, fast readout times, simpler readers and easier automation are the main advantages of OSL in comparison with TLD. This work aimed to study the application of OSL technique using lithium fluoride dosimeters doped with magnesium and titanium (LiF:Mg,Ti) for application in beta and gamma dosimetry. -- Highlights: •Study of Optically Stimulated Luminescence of LiF:Mg,Ti and microLiF:Mg,Ti. •OSL response of TLD-100 dosimeters to beta and gamma radiation. •Analysis of repeatability and lowest levels of detection of detectors LiF:Mg,Ti 16. Durability and shielding performance of borated Ceramicrete coatings in beta and gamma radiation fields Energy Technology Data Exchange (ETDEWEB) Wagh, Arun S., E-mail: asw@anl.gov [Environmental Science Division, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439 (United States); Sayenko, S.Yu.; Dovbnya, A.N.; Shkuropatenko, V.A.; Tarasov, R.V.; Rybka, A.V.; Zakharchenko, A.A. [National Science Center, Kharkov Institute of Physics and Technology, Kharkov (Ukraine) 2015-07-15 Highlights: • It incorporates all suggestions by the reviewers. • Explanation to each new term is provided and suitable references are given. • Sample identities have been streamlined by revising the text and the tables. • Some figures have been redrawn. - Abstract: Ceramicrete™, a chemically bonded phosphate ceramic, was developed for nuclear waste immobilization and nuclear radiation shielding. Ceramicrete products are fabricated by an acid–base reaction between magnesium oxide and mono potassium phosphate. Fillers are used to impart desired properties to the product. Ceramicrete’s tailored compositions have resulted in several commercial structural products, including corrosion- and fire-protection coatings. Their borated version, called Borobond™, has been studied for its neutron shielding capabilities and is being used in structures built for storage of nuclear materials. This investigation assesses the durability and shielding performance of borated Ceramicrete coatings when exposed to gamma and beta radiations to predict the composition needed for optimal shielding performance in a realistic nuclear radiation field. Investigations were conducted using experimental data coupled with predictive Monte Carlo computer model. The results show that it is possible to produce products for simultaneous shielding of all three types of nuclear radiations, viz., neutrons, gamma-, and beta-rays. Additionally, because sprayable Ceramicrete coatings exhibit excellent corrosion- and fire-protection characteristics on steel, this research also establishes an opportunity to produce thick coatings to enhance the shielding performance of corrosion and fire protection coatings for use in high radiation environment in nuclear industry. 17. Vibrational and chiroptical spectroscopic characterization of gamma-turn model cyclic tetrapeptides containing two beta-Ala residues. Science.gov (United States) Vass, Elemér; Majer, Zsuzsa; Kohalmy, Krisztina; Hollósi, Miklós 2010-08-01 The optical spectroscopic characterization of gamma-turns in solution is uncertain and their distinction from beta-turns is often difficult. This work reports systematic ECD and vibrational circular dichroism (VCD) spectroscopic studies on gamma-turn model cyclic tetrapeptides cyclo(Ala-beta-Ala-Pro-beta-Ala) (1), cyclo(Pro-beta-Ala-Pro-beta-Ala) (2) and cyclo(Ala-beta-Ala-Ala-beta-Ala) (3). Conformational analysis performed at the 6-31G(d)/B3LYP level of theory using an adequate PCM solvent model predicted one predominant conformer for 1-3, featuring two inverse gamma-turns. The ECD spectra in ACN of 1 and 2 are characterized by a negative n-->pi* band near 230 nm and a positive pi-->pi* band below 200 nm with a long wavelength shoulder. The ECD spectra in TFE of 1-3 show similar spectra with blue-shifted bands. The VCD spectra in ACN-d(3) of 1 and 2 show a +/-/+/- amide I sign pattern resulting from four uncoupled vibrations in the case of 1 and a sequence of two positive couplets in the case of 2. A -/+/+/- amide I VCD pattern was measured for 3 in TFE-d(2). All three peptides give a positive couplet or couplet-like feature (+/-) in the amide II region. VCD spectroscopy, in agreement with theoretical calculations revealed that low frequency amide I vibrations (at approximately 1630 cm(-1) or below) are indicative of a C(7) H-bonded inverse gamma-turns with Pro in position 2, while gamma-turns encompassing Ala absorb at higher frequency (above 1645 cm(-1)). Copyright 2010 Wiley-Liss, Inc. 18. Thermodynamics in Neurodegenerative Diseases: Interplay Between Canonical WNT/Beta-Catenin Pathway-PPAR Gamma, Energy Metabolism and Circadian Rhythms. Science.gov (United States) Vallée, Alexandre; Lecarpentier, Yves; Guillevin, Rémy; Vallée, Jean-Noël 2018-03-23 Entropy production rate is increased by several metabolic and thermodynamics abnormalities in neurodegenerative diseases (NDs). Irreversible processes are quantified by changes in the entropy production rate. This review is focused on the opposing interactions observed in NDs between the canonical WNT/beta-catenin pathway and PPAR gamma and their metabolic and thermodynamic implications. In amyotrophic lateral sclerosis and Huntington's disease, WNT/beta-catenin pathway is upregulated, whereas PPAR gamma is downregulated. In Alzheimer's disease and Parkinson's disease, WNT/beta-catenin pathway is downregulated while PPAR gamma is upregulated. The dysregulation of the canonical WNT/beta-catenin pathway is responsible for the modification of thermodynamics behaviors of metabolic enzymes. Upregulation of WNT/beta-catenin pathway leads to aerobic glycolysis, named Warburg effect, through activated enzymes, such as glucose transporter (Glut), pyruvate kinase M2 (PKM2), pyruvate dehydrogenase kinase 1(PDK1), monocarboxylate lactate transporter 1 (MCT-1), lactic dehydrogenase kinase-A (LDH-A) and inactivation of pyruvate dehydrogenase complex (PDH). Downregulation of WNT/beta-catenin pathway leads to oxidative stress and cell death through inactivation of Glut, PKM2, PDK1, MCT-1, LDH-A but activation of PDH. In addition, in NDs, PPAR gamma is dysregulated, whereas it contributes to the regulation of several key circadian genes. NDs show many dysregulation in the mediation of circadian clock genes and so of circadian rhythms. Thermodynamics rhythms operate far-from-equilibrium and partly regulate interactions between WNT/beta-catenin pathway and PPAR gamma. In NDs, metabolism, thermodynamics and circadian rhythms are tightly interrelated. 19. Right frontal gamma and beta band enhancement while solving a spatial puzzle with insight. Science.gov (United States) Rosen, A; Reiner, M 2017-12-01 Solving a problem with an "a-ha" effect is known as insight. Unlike incremental problem solving, insight is sudden and unique, and the question about its distinct brain activity, intrigues many researchers. In this study, electroencephalogram signals were recorded from 12 right handed, human participants before (baseline) and while they solved a spatial puzzle known as the '10 coin puzzle' that could be solved incrementally or by insight. Participants responded as soon as they reached a solution and reported whether the process was incremental or by sudden insight. EEG activity was recorded from 19 scalp locations. We found significant differences between insight and incremental solvers in the Gamma and Beta 2 bands in frontal areas (F8) and in the alpha band in right temporal areas (T6). The right-frontal gamma indicates a process of restructuring which leads to an insight solution, in spatial problems, further suggesting a universal role of gamma in restructuring. These results further suggest that solving a spatial puzzle via insight requires exclusive brain areas and neurological-cognitive processes which may be important for meta-cognitive components of insight solutions, including attention and monitoring of the solution. Copyright © 2016 Elsevier B.V. All rights reserved. 20. Frequency and function in the basal ganglia: the origins of beta and gamma band activity. Science.gov (United States) Blenkinsop, Alexander; Anderson, Sean; Gurney, Kevin 2017-07-01 Neuronal oscillations in the basal ganglia have been observed to correlate with behaviours, although the causal mechanisms and functional significance of these oscillations remain unknown. We present a novel computational model of the healthy basal ganglia, constrained by single unit recordings from non-human primates. When the model is run using inputs that might be expected during performance of a motor task, the network shows emergent phenomena: it functions as a selection mechanism and shows spectral properties that match those seen in vivo. Beta frequency oscillations are shown to require pallido-striatal feedback, and occur with behaviourally relevant cortical input. Gamma oscillations arise in the subthalamic-globus pallidus feedback loop, and occur during movement. The model provides a coherent framework for the study of spectral, temporal and functional analyses of the basal ganglia and lays the foundation for an integrated approach to study basal ganglia pathologies such as Parkinson's disease in silico. Neural oscillations in the basal ganglia (BG) are well studied yet remain poorly understood. Behavioural correlates of spectral activity are well described, yet a quantitative hypothesis linking time domain dynamics and spectral properties to BG function has been lacking. We show, for the first time, that a unified description is possible by interpreting previously ignored structure in data describing globus pallidus interna responses to cortical stimulation. These data were used to expose a pair of distinctive neuronal responses to the stimulation. This observation formed the basis for a new mathematical model of the BG, quantitatively fitted to the data, which describes the dynamics in the data, and is validated against other stimulus protocol experiments. A key new result is that when the model is run using inputs hypothesised to occur during the performance of a motor task, beta and gamma frequency oscillations emerge naturally during static-force and 1. Beta decay of the fission product 125Sb and a new complete evaluation of absolute gamma ray transition intensities Science.gov (United States) Rajput, M. U.; Ali, N.; Hussain, S.; Mujahid, S. A.; MacMahon, D. 2012-04-01 The radionuclide 125Sb is a long-lived fission product, which decays to 125Te by negative beta emission with a half-life of 1008 day. The beta decay is followed by the emission of several gamma radiations, ranging from low to medium energy, that can suitably be used for high-resolution detector calibrations, decay heat calculations and in many other applications. In this work, the beta decay of 125Sb has been studied in detail. The complete published experimental data of relative gamma ray intensities in the beta decay of the radionuclide 125Sb has been compiled. The consistency analysis was performed and discrepancies found at several gamma ray energies. Evaluation of the discrepant data was carried out using Normalized Residual and RAJEVAL methods. The decay scheme balance was carried out using beta branching ratios, internal conversion coefficients, populating and depopulating gamma transitions to 125Te levels. The work has resulted in the consistent conversion factor equal to 29.59(13) %, and determined a new evaluated set of the absolute gamma ray emission probabilities. The work has also shown 22.99% of the delayed intensity fraction as outgoing from the 58 d isomeric 144 keV energy level and 77.01% of the prompt intensity fraction reaching to the ground state from the other excited states. The results are discussed and compared with previous evaluations. The present work includes additional experimental data sets which were not included in the previous evaluations. A new set of recommended relative and absolute gamma ray emission probabilities is presented. 2. Beta decay of the fission product 125Sb and a new complete evaluation of absolute gamma ray transition intensities International Nuclear Information System (INIS) Rajput, M.U.; Ali, N.; Hussain, S.; Mujahid, S.A.; MacMahon, D. 2012-01-01 The radionuclide 125 Sb is a long-lived fission product, which decays to 125 Te by negative beta emission with a half-life of 1008 day. The beta decay is followed by the emission of several gamma radiations, ranging from low to medium energy, that can suitably be used for high-resolution detector calibrations, decay heat calculations and in many other applications. In this work, the beta decay of 125 Sb has been studied in detail. The complete published experimental data of relative gamma ray intensities in the beta decay of the radionuclide 125 Sb has been compiled. The consistency analysis was performed and discrepancies found at several gamma ray energies. Evaluation of the discrepant data was carried out using Normalized Residual and RAJEVAL methods. The decay scheme balance was carried out using beta branching ratios, internal conversion coefficients, populating and depopulating gamma transitions to 125 Te levels. The work has resulted in the consistent conversion factor equal to 29.59(13) %, and determined a new evaluated set of the absolute gamma ray emission probabilities. The work has also shown 22.99% of the delayed intensity fraction as outgoing from the 58 d isomeric 144 keV energy level and 77.01% of the prompt intensity fraction reaching to the ground state from the other excited states. The results are discussed and compared with previous evaluations. The present work includes additional experimental data sets which were not included in the previous evaluations. A new set of recommended relative and absolute gamma ray emission probabilities is presented. 3. A gene duplication led to specialized gamma-aminobutyrate and beta-alanine aminotransferase in yeast DEFF Research Database (Denmark) Andersen, Gorm; Andersen, Birgit; Dobritzsch, D. 2007-01-01 and related yeasts have two different genes/enzymes to apparently 'distinguish' between the two reactions in a single cell. It is likely that upon duplication similar to 200 million years ago, a specialized Uga1p evolved into a 'novel' transaminase enzyme with broader substrate specificity.......In humans, beta-alanine (BAL) and the neurotransmitter gamma-aminobutyrate (GABA) are transaminated by a single aminotransferase enzyme. Apparently, yeast originally also had a single enzyme, but the corresponding gene was duplicated in the Saccharomyces kluyveri lineage. SkUGA1 encodes a homologue...... to characterize the substrate specificity and kinetic parameters of the four enzymes. It was found that the cofactor pyridoxal 5'-phosphate is needed for enzymatic activity and alpha-ketoglutarate, and not pyruvate, as the amino group acceptor. SkPyd4p preferentially uses BAL as the amino group donor (V... 4. Assessment of gamma, beta and alpha-particle-emitting nuclides in marine samples International Nuclear Information System (INIS) Holm, E. 1997-01-01 Depending on the physical properties of radionuclides different systems must be used for their measurement. Most convenient is if gamma spectrometry can be used by germanium, Silicon or Scintillation detectors (eg. NaI). If, however, the main emission consists of beta or alpha particles or low-energy photons as is the case for radionuclides decaying by electron capture, radiochemical separation and specific source preparations must be undertaken. In such cases also the radiochemical yield must be determined. The radiochemical part mainly follows the lines presented by prof. T. Jaakkola, Department of Radiochemistry, Helsinki, Finland, at a course in radioecology in Lurid, 1991. For very long-lived radionuclides other methods such as mass spectrometry are superior although often associated with sophisticated expensive instrumentation. (author) 5. An energy-independent dose rate meter for beta and gamma radiation International Nuclear Information System (INIS) Heinzelmann, M.; Keller, M. 1986-01-01 An easy to handle dose rate meter has been developed at the Juelich Nuclear Research Centre with a small probe for the energy-independent determination of the dose rate in mixed radiation fields. The dose rate meter contains a small ionisation chamber with a volume of 15.5 cm 3 . The window of the ionisation chamber consists of an aluminised plastic foil of 7 mg.cm -2 . The dose rate meter is suitable for determining the dose rate in skin. With a supplementary depth dose cap, the dose rate can be determined in tissue at a depth of 1 cm. The dose rate meter is energy-independent within +-20% for 147 Pm, 204 Tl and 90 Sr/ 90 Y beta radiation and for gamma radiation in the energy range above 35 keV. (author) 6. Differential expression of gamma-tubulin and class III beta-tubulin in medulloblastomas and human medulloblastoma cell lines Czech Academy of Sciences Publication Activity Database Caracciolo, V.; D´Agostino, L.; Dráberová, Eduarda; Sládková, Vladimíra; Crozier-Fitzgerald, C.; Agamanolis, D.P.; De Chadarévian, J.P.; Legido, A.; Giordano, A.; Dráber, Pavel; Katsetos, C.D. 2010-01-01 Roč. 223, č. 2 (2010), s. 519-529 ISSN 0021-9541 R&D Projects: GA AV ČR KAN200520701 Institutional research plan: CEZ:AV0Z50520514 Keywords : gamma-tubulin * beta III-tubulin * meduloblastoma Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.986, year: 2010 7. An easy and efficient method to produce {gamma}-amino alcohols by reduction of {beta}-enamino ketones Energy Technology Data Exchange (ETDEWEB) Harris, Maria Ines N.C.; Braga, Antonio C.H. [Universidade Estadual de Campinas, SP (Brazil). Inst. de Quimica]. E-mail: herrera@iqm.unicamp.br 2004-12-01 Reduction of {beta}-enamino ketones 2 with NaBH{sub 4} in glacial acetic acid gave {gamma}-amino alcohols 1 in 70% to 98% yield with diastereomeric excesses, preferentially the syn product, from 44% to 90%. The stereochemistry of these compounds was confirmed by analysis of their tetrahydro-1,3-oxazine derivatives 3. (author) 8. Peculiarities of the clinical course of radiation sickness and organizational decisions for radiation accidents with beta-gamma sources International Nuclear Information System (INIS) Guskova, A.K.; Gusev, I.A. 1998-01-01 The analysis of a number of recent large scale accidents involving beta-gamma sources in the last 40 years, such as those of the Marshall Islands (1954); Windscale, UK (1957); Chernobyl, USSR (1986) and Goiania, Brazil (1987) demonstrates the predominance and importance of health and social impacts. (author) 9. Effect of water on self-assembled tubules in {beta}-sitosterol + {gamma}-oryzanol-based organogels Energy Technology Data Exchange (ETDEWEB) Adel, Ruud den; Heussen, Patricia C M; Bot, Arjen, E-mail: ruud-den.adel@unilever.co [Unilever Research and Development Vlaardingen, Olivier van Noortlaan 120, NL-3133 AT Vlaardingen (Netherlands) 2010-10-01 Mixtures of {beta}-sitosterol and {gamma}-oryzanol form a network in triglyceride oil that may serve as an alternative to the network of small crystallites of triglycerides occurring in regular oil structuring. The present x-ray diffraction study investigates the relation between the crystal forms of the individual compounds and the mixture in oil, water and emulsion. {beta}-Sitosterol and {gamma}-oryzanol form normal crystals in oil, in water, or in emulsions. The crystals are sensitive to the presence of water. The mixture of {beta}-sitosterol + {gamma}-oryzanol forms crystals in water and emulsions that can be traced back to the crystals of the pure compounds. Only in oil, a completely different structure emerges in the mixture of {beta}-sitosterol + {gamma}-oryzanol, which bears no relation to the structures that are formed by both individual compounds, and which can be identified as a self-assembled tubule (diameter 7.2{+-}0.1 nm, wall thickness 0.8{+-}0.2 nm). 10. Lipopolysaccharide contamination of beta-lactoglobulin affects the immune response against intraperitoneally and orally administered antigen DEFF Research Database (Denmark) Pedersen, Susanne Brix; Kjær, T.M.R.; Barkholt, Vibeke 2004-01-01 Microbial components in the environment are potent activators of the immune system with capacity to shift the active immune response towards priming of Th1 and/or Th2 cells. Lipopolysaccharide (LPS), a cell-wall component of Gram- negative bacteria, is extensively present in food products like co......-LG was contaminated with LPS. Conclusions: LPS contamination of an aqueous protein solution does not affect oral tolerance induction, whereas LPS present in emulsion prevents oral tolerance induction towards the food protein.......Microbial components in the environment are potent activators of the immune system with capacity to shift the active immune response towards priming of Th1 and/or Th2 cells. Lipopolysaccharide (LPS), a cell-wall component of Gram- negative bacteria, is extensively present in food products like cow......'s milk. It is not well established, however, how this presence of LPS affects oral tolerance induction. Methods: We studied the effect of LPS contamination in a commercial preparation of the cow milk protein beta-lactoglobulin (beta-LG) on antigen-specific immune responses. IgG1/IgG2a production upon... 11. An Optimized Design of Single-Channel Beta-Gamma Coincidence Phoswich Detector by Geant4 Monte Carlo Simulations Directory of Open Access Journals (Sweden) Weihua Zhang 2011-01-01 Full Text Available An optimized single-channel phoswich well detector design has been proposed and assessed in order to improve beta-gamma coincidence measurement sensitivity of xenon radioisotopes. This newly designed phoswich well detector consists of a plastic beta counting cell (BC404 embedded in a CsI(Tl crystal coupled to a photomultiplier tube. The BC404 is configured in a cylindrical pipe shape to minimise light collection deterioration. The CsI(Tl crystal consists of a rectangular part and a semicylindrical scintillation part as a light reflector to increase light gathering. Compared with a PhosWatch detector, the final optimized detector geometry showed 15% improvement in the energy resolution of a 131mXe 129.4 keV conversion electron peak. The predicted beta-gamma coincidence efficiencies of xenon radioisotopes have also been improved accordingly. 12. A New Method for Processing Airborne Gamma Ray Spectrometry Data for Mapping Low Level Contaminations DEFF Research Database (Denmark) Aage, Helle Karina; Korsbech, Uffe C C; Bargholz, Kim 1999-01-01 A new technique for processing airborne gamma ray spectrometry data has been developed. It is based on the noise adjusted singular value decomposition method introduced by Hovgaard in 1997. The new technique opens for mapping of very low contamination levels. It is tested with data from Latvia...... where the remaining contamination from the 1986 Chernobyl accident together with fallout from the atmospheric nuclear weapon tests includes Cs-137 at levels often well below 1 kBq/m(2) equivalent surface contamination. The limiting factors for obtaining reliable results are radon in the air, spectrum... 13. Line C17: alpha and medium-level beta-gamma laboratory pilot facility International Nuclear Information System (INIS) Calor, J.N.; Mauborgne, B.; Montuir, M. 2000-01-01 The Process Development Laboratory (LDP) uses the ATALANTE C17 line for integral testing in order to develop and validate spent fuel reprocessing methods and for overall qualification of calculation codes. Line C 17 comprises shielded cells and glove boxes, equipped with centrifugal extractors and laboratory-scale mixer-settlers to test liquid-liquid extraction processes in an alpha and medium-level beta-gamma environment. The high reliability and precision of the process instrumentation and control system allow full control of operating parameters and comprehensive operating data recording, meeting the experimentation quality requirements necessary for qualifying calculation codes. Direct online spectrophotometric analysis at various points in the process provides real-time concentration data for vital elements, some of which are difficult to analyze offline because of their poor chemical stability. Online analyses, supplemented when necessary by gamma spectrometry, provide valuable process control input for reaching stabilized operating conditions. Fifteen radioactive test campaigns have been successfully completed since line C 17 was commissioned in June 1995. (authors) 14. Application of RUB-01P beta radiometer to control contamination of milk and dairy produce International Nuclear Information System (INIS) Bachurin, A.V.; Donskaya, G.A.; Koroleva, M.S.; Titov, S.K. 1990-01-01 RUB-01P beta-radiometer to control radioactive contamination of milk and dairy produce characterized by a number of advantages as compared to RKB-4-1eM manufactured earlier is described. Device is designed using a new element base, simgle-action, characterized by increased reliability, can operate on-line with ELEKTRONIKA MK-64 programmed microcalculater. Radiometer output is printed out to a void operator errors and to record measurement results. Radiometer main error is maximum 50 %. Data on device sensitivity at measurements using BDZhB-05P, BDZhB-06P1, BDZhB-06P detection units are given 15. Effect of gamma radiation on the content {beta}-carotene and volatile compounds of cantaloupe melon Energy Technology Data Exchange (ETDEWEB) Souza, Stefania P. de; Cardozo, Monique; Lima, Keila dos S.C.; Lima, Antonio L. dos S., E-mail: keila@ime.eb.br, E-mail: santoslima@ime.eb.br [Departamento de Quimica - IME - Instituto Militar de Engenharia, RJ (Brazil) 2011-07-01 The Japanese melon or cantaloupe (Cucumis melo L.) is characterized by fruits with almost 1.0 Kg, pulp usually salmon and musky scent. The fruits when ripe are sensitive to post harvest handling. This low transport resistance and reduced shelf-life makes it necessary to delay the ripening of fruit. In this way the use of irradiation technique is a good choice. Irradiation is the process of exposing food to high doses of gamma rays. The processing of fruits and vegetables with ionizing radiation has as main purpose to ensure its preservation. However, like other forms of food processing, irradiation may cause changes in chemical composition and nutritional value. This study aims to assess possible changes in carotene content and volatile compounds caused by exposure of cantaloupe melon fruit to gamma irradiation. Irradiation of the samples occurred in Centro Tecnologico do Exercito (Guaratiba-RJ), using Gamma irradiator (Cs{sub 137} source, dose rate 1.8 kGy/h), being applied 0.5 and 1.0 kGy doses and separated a control group not irradiated. Carotenoids were extracted with acetone and then suffered partition to petroleum ether, solvent was removed under nitrogen flow and the remainder dissolved in acetone again. The chromatographic analysis was performed using a Shimadzu gas chromatograph, with C30 column. For volatile compounds, we used gas chromatography (GC) associated with mass (MS). As a result, it was verified in analysis of carotenoids that cantaloupe melon is rich in {beta}-carotene. Both total content of carotenoids and specific {beta}-carotene amount wasn't suffer significant reduction in irradiated fruits at two doses, demonstrating that the irradiation process under these conditions implies a small loss of nutrients. The major volatile compounds were: 2-methyl-1-butyl acetate, ethyl hexanoate, n-hexyl acetate, benzyl acetate, 6-nonenyl acetate and {alpha} -terpinyl acetate. For all compounds we observed an increase in the volatile content in 0.5 k 16. The gamma irradiation of tragacanth: effect on microbial contamination and rheology International Nuclear Information System (INIS) Jacobs, G.P. 1979-01-01 The use of gamma radiation for the sterilization of tragacanth, which is used in pharmaceuticals as a thickening and suspending agent, was investigated. The effect of different gamma doses on the rheological profile of tragacanth mucilage, prepared from tragacanth irradiated in the dry state, and the efficiency of such treatments in reducing the pre-irradiation microbial load were studied. A decrease in viscosity with increasing dose was found in the range 0.1-5 Mrads. All irradiated samples were found to be free from contamination, although the 0.1 Mrad irradiation was only carried out on a less contaminated sample. The radiation chemistry of tragacanth is discussed. It is concluded that although even small doses affect the viscosity, minimal doses of (say) 0.1 Mrad may be used for reducing microbial load particularly if the initial contamination is not excessive. (author) 17. Inactivation of fungal contaminants on Korean traditional cashbox by gamma irradiation Science.gov (United States) Choi, Jong-il; Lim, Sangyong 2016-01-01 In this study, gamma irradiation was applied to decontaminate a Korean cultural artifact, a wooden cashbox stored in local museum. Fungi isolated from the wooden cashbox were identified by 18S rDNA sequencing methods. It was observed that the isolated fungi exhibited high similarity to Aspergillus niger, Penicillium verruculosum, and Trichoderma viride. Each strain was tested for sensitivity to gamma irradiation, and was inactivated by the irradiation at a dose of 5 kGy. The wooden cashbox was thus gamma-irradiated at this dose (5 kGy), and consequently decontaminated. Two months after the irradiation, when the wooden cashbox was retested to detect biological contamination, no fungi were found. Therefore, these results suggest that gamma irradiation at a low dose of 5 kGy can be applied for successful decontamination of wooden artifacts. 18. Spectral shapes and a beta-gamma directional correlation in the beta decay of 172Tm (Jpi = 2-) DEFF Research Database (Denmark) Gregers Hansen, P.; Loft Nielsen, H.; Wilsky, K. 1966-01-01 The isotope 172Tm populates the 0+, 2+ and 4+ states of the 172Yb ground-state rotational band directly in beta decay. The shapes and intensities of the three beta groups have been measured by means of a six-gap magnetic spectrometer operated in coincidence with a Nal(Tl) crystal. The experimenta... 19. The p110beta isoform of phosphoinositide 3-kinase signals downstream of G protein-coupled receptors and is functionally redundant with p110gamma. Science.gov (United States) Guillermet-Guibert, Julie; Bjorklof, Katja; Salpekar, Ashreena; Gonella, Cristiano; Ramadani, Faruk; Bilancio, Antonio; Meek, Stephen; Smith, Andrew J H; Okkenhaug, Klaus; Vanhaesebroeck, Bart 2008-06-17 The p110 isoforms of phosphoinositide 3-kinase (PI3K) are acutely regulated by extracellular stimuli. The class IA PI3K catalytic subunits (p110alpha, p110beta, and p110delta) occur in complex with a Src homology 2 (SH2) domain-containing p85 regulatory subunit, which has been shown to link p110alpha and p110delta to Tyr kinase signaling pathways. The p84/p101 regulatory subunits of the p110gamma class IB PI3K lack SH2 domains and instead couple p110gamma to G protein-coupled receptors (GPCRs). Here, we show, using small-molecule inhibitors with selectivity for p110beta and cells derived from a p110beta-deficient mouse line, that p110beta is not a major effector of Tyr kinase signaling but couples to GPCRs. In macrophages, both p110beta and p110gamma contributed to Akt activation induced by the GPCR agonist complement 5a, but not by the Tyr kinase ligand colony-stimulating factor-1. In fibroblasts, which express p110beta but not p110gamma, p110beta mediated Akt activation by the GPCR ligands stromal cell-derived factor, sphingosine-1-phosphate, and lysophosphatidic acid but not by the Tyr kinase ligands PDGF, insulin, and insulin-like growth factor 1. Introduction of p110gamma in these cells reduced the contribution of p110beta to GPCR signaling. Taken together, these data show that p110beta and p110gamma can couple redundantly to the same GPCR agonists. p110beta, which shows a much broader tissue distribution than the leukocyte-restricted p110gamma, could thus provide a conduit for GPCR-linked PI3K signaling in the many cell types where p110gamma expression is low or absent. 20. Scintillation response of CsI: Tl crystal under neutron, gamma, alpha particles and beta excitations Energy Technology Data Exchange (ETDEWEB) Pereira, Maria da Conceicao Costa; Madi Filho, Tufic; Lopes, Valdir Maciel; Berretta, Jose Roberto; Cardenas, Jose Patricio Nahuel, E-mail: macoper@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil) 2015-07-01 Among the converters of X and gamma radiation in light photons, known as scintillators, the one which is the most efficient emits photons with a wavelength near 400 nm. Particularly, among them, the cesium iodine doped with thallium (CsI:Tl) crystal is that which matches better between the light emission spectrum (peak at 540 nm) and the quantum sensitivity curve of the photodiodes and CCD (Charge Coupled Device). This explains the renewed interest in using this crystal as scintillator. Although the CsI:Tl crystal is commercially available, its local development would give the possibility to obtain it in different geometric configurations and coupling. Moreover, there is a special interest in studying new conditions that will alter the properties of this crystal in order to achieve a optimal level of its functional characteristics. Having an efficient national scintillator with low cost is a strategic opportunity to study the response of a detector applied to different types of radiation. The crystal of cesium iodide activated with thallium (CsI:Tl) has a high gamma detection efficiency per unit volume. In this paper, the CsI:Tl crystal, grown by the vertical Bridgman technique in evacuated silica ampoules and with the purpose of use as radiation detectors, is described. To evaluate the scintillator, measures of the thallium distribution in the crystal volume were taken, with overall efficiency score. The scintillator response was studied through gamma radiation from sources of {sup 137}Cs, {sup 60}Co, {sup 22}Na, {sup 54}Mn, {sup 131}I and {sup 99m}Tc; the beta radiation from source of {sup 90}Sr/{sup 90}Y, alpha particles from {sup 241}Am source and the scintillator response to neutrons from Am/Be source. The energetic resolution for {sup 137}Cs gamma rays (662 keV) was 10%. The results showed the validity of using the CsI:Tl crystal developed in our laboratory, in many applications in the area of radiation detectors. (author) 1. Novel cell-based assay for detection of thyroid receptor beta-interacting environmental contaminants. Science.gov (United States) Stavreva, Diana A; Varticovski, Lyuba; Levkova, Ludmila; George, Anuja A; Davis, Luke; Pegoraro, Gianluca; Blazer, Vicki; Iwanowicz, Luke; Hager, Gordon L 2016-08-10 Even though the presence of endocrine disrupting chemicals (EDCs) with thyroid hormone (TH)-like activities in the environment is a major health concern, the methods for their efficient detection and monitoring are still limited. Here we describe a novel cell assay, based on the translocation of a green fluorescent protein (GFP)-tagged chimeric molecule of glucocorticoid receptor (GR) and the thyroid receptor beta (TRβ) from the cytoplasm to the nucleus in the presence of TR ligands. Unlike the constitutively nuclear TRβ, this GFP-GR-TRβ chimera is cytoplasmic in the absence of hormone while translocating to the nucleus in a time- and concentration-dependent manner upon stimulation with triiodothyronine (T3) and thyroid hormone analogue, TRIAC, while the reverse triiodothyronine (3,3',5'-triiodothyronine, or rT3) was inactive. Moreover, GFP-GR-TRβ chimera does not show any cross-reactivity with the GR-activating hormones, thus providing a clean system for the screening of TR beta-interacting EDCs. Using this assay, we demonstrated that Bisphenol A (BPA) and 3,3',5,5'-Tetrabromobisphenol (TBBPA) induced GFP-GR-TRβ translocation at micro molar concentrations. We screened over 100 concentrated water samples from different geographic locations in the United States and detected a low, but reproducible contamination in 53% of the samples. This system provides a novel high-throughput approach for screening for endocrine disrupting chemicals (EDCs) interacting with TR beta. Published by Elsevier Ireland Ltd. 2. Novel cell-based assay for detection of thyroid receptor beta-interacting environmental contaminants International Nuclear Information System (INIS) Stavreva, Diana A.; Varticovski, Lyuba; Levkova, Ludmila; George, Anuja A.; Davis, Luke; Pegoraro, Gianluca; Blazer, Vicki; Iwanowicz, Luke; Hager, Gordon L. 2016-01-01 Even though the presence of endocrine disrupting chemicals (EDCs) with thyroid hormone (TH)-like activities in the environment is a major health concern, the methods for their efficient detection and monitoring are still limited. Here we describe a novel cell assay, based on the translocation of a green fluorescent protein (GFP)—tagged chimeric molecule of glucocorticoid receptor (GR) and the thyroid receptor beta (TRβ) from the cytoplasm to the nucleus in the presence of TR ligands. Unlike the constitutively nuclear TRβ, this GFP-GR-TRβ chimera is cytoplasmic in the absence of hormone while translocating to the nucleus in a time- and concentration-dependent manner upon stimulation with triiodothyronine (T3) and thyroid hormone analogue, TRIAC, while the reverse triiodothyronine (3,3′,5′-triiodothyronine, or rT3) was inactive. Moreover, GFP-GR-TRβ chimera does not show any cross-reactivity with the GR-activating hormones, thus providing a clean system for the screening of TR beta-interacting EDCs. Using this assay, we demonstrated that Bisphenol A (BPA) and 3,3′,5,5′-Tetrabromobisphenol (TBBPA) induced GFP-GR-TRβ translocation at micro molar concentrations. We screened over 100 concentrated water samples from different geographic locations in the United States and detected a low, but reproducible contamination in 53% of the samples. This system provides a novel high-throughput approach for screening for endocrine disrupting chemicals (EDCs) interacting with TR beta. 3. Gamma sensitivity of the Eberline PCM-1 International Nuclear Information System (INIS) Blanton, J.D. 1988-01-01 This paper reports that normally, alarm setpoints for the Eberline PCM-1 series personnel contamination monitors are calculated based upon efficiencies measured using 100-cm 2 or larger beta or mixed beta-gamma sources. This simulates the type of contamination most frequently encountered on personnel and clothing--low-level, distributed beta-gamma emitters. In most circumstances, the PCM-1's sensitivity to the other type of contamination encountered in nuclear plant work--hot particles--would be expected to be the same as, or better than, its sensitivity to distributed contamination. However, particles that are deposited on skin or clothing can be partially shielded from the view of the PCM-1's detectors. In these situations, the PCm-1's sensitivity to gamma radiation may be more relevant than its sensitivity to betas 4. Calibrated radioactive sources - absolute measurements using a 4{pi} {beta}-{gamma} apparatus; Sources etalons de radioactivite - mesures absolues au moyen d'un ensemble 4{pi} {beta}-{gamma} Energy Technology Data Exchange (ETDEWEB) Benoit, P; Philis, C [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires 1965-07-01 In this paper, the principle of the standardization of the radioisotopes by the 4{pi} {beta} - {gamma} coincidence method is reminded. Some theoretical examples are given emphasizing on instrumental coincidences and their corrections. The experimental apparatus is described: one discusses the choice of the experimental conditions for the many isotopes measured. Results are given and discussed. In appendix we describe the preparation of the sources. (authors) [French] Dans ce rapport, nous rappelons d'abord le principe de la methode d'etalonnage 4{pi} {beta} - {gamma} en donnant quelques exemples theoriques et en insistant sur la correction des erreurs instrumentales. Une description critique de l'appareillage utilise est donnee. On discute le choix des conditions experimentales pour divers isotopes mesures et les resultats obtenus. En annexe, nous decrivons la fabrication des sources que nous mesurons. 5. Ultraviolet observations of. beta. Persei,. mu. /sup 1/ Scorpii and. gamma. /sub 2/ Velorum with the TD-1A satellite Energy Technology Data Exchange (ETDEWEB) Sahade, J [Instituto de Astronomia y Fisica del Espacio, Buenos Aires (Argentina); van der Hucht, K A [Laboratorium voor Ruimteonderzoek, Utrecht (Netherlands). Space Research Lab. 1980-05-01 This paper reports on the results of a study of S59 ultraviolet spectral scans of the spectroscopic binaries ..beta.. Persei, ..mu../sup 1/ Scorpii and ..gamma../sub 2/ Velorum. In the case of ..mu../sup 1/ Sco it was found that the Mg II doublet at 2800 Angstroem undergoes intensity variations that may be indicative of variable emission in the photographic spectrum. The continuum in the 2490-2590 Angstroem range deviates from the continuum of the 'comparison stars'. In ..gamma../sub 2/ Vel, flux variations in the 2770-2870 A region have been detected. 6. Gamma-spectrometric and total alpha-beta counting methods for radioactivity analysis of deuterium depleted water International Nuclear Information System (INIS) Ferdes, Ov. S.; Mladin, C.; Vladu, Mihaela; Bulubasa, G.; Bidica, N. 2008-01-01 According to national regulations, as well as to the EU directive on the quality of drinking water, the radionuclide concentrations represent some of the drinking water quality parameters. Among the most important radioactivity content parameters are: the total alpha and total beta concentration (Bq/l); K-40 content, and the gamma-nuclides volume activities. The paper presents the measuring methods for low-level total alpha and/or beta counting of volume samples, as well as the high-resolution gamma-ray spectrometric method used to measure the volume activity of nuclides in drinking water. These methods are applied to monitor the radioactivity content and quality of the QLARIVIA brand of Deuterium depleted water (DDW). There are discussed the performances of these applied methods as well as some preliminary results. (authors) 7. Latent transforming growth factor beta1 activation in situ: quantitative and functional evidence after low-dose gamma-irradiation Science.gov (United States) Ehrhart, E. J.; Segarini, P.; Tsang, M. L.; Carroll, A. G.; Barcellos-Hoff, M. H.; Chatterjee, A. (Principal Investigator) 1997-01-01 The biological activity of transforming growth factor beta1 (TGF-beta) is controlled by its secretion as a latent complex in which it is noncovalently associated with latency-associated peptide (LAP). Activation is the extracellular process in which TGF-beta is released from LAP, and is considered to be a primary regulatory control. We recently reported rapid and persistent changes in TGF-beta immunoreactivity in conjunction with extracellular matrix remodeling in gamma-irradiated mouse mammary gland. Our hypothesis is that these specific changes in immunoreactivity are indicative of latent TGF-beta activation. In the present study, we determined the radiation dose response and tested whether a functional relationship exists between radiation-induced TGF-beta and collagen type III remodeling. After radiation exposures as low as 0.1 Gy, we detected increased TGF-beta immunoreactivity in the mammary epithelium concomitant with decreased LAP immunostaining, which are events consistent with activation. Quantitative image analysis demonstrated a significant (P=0.0005) response at 0.1 Gy without an apparent threshold and a linear dose response to 5 Gy. However, in the adipose stroma, loss of LAP demonstrated a qualitative threshold at 0.5 Gy. Loss of LAP paralleled induction of collagen III immunoreactivity in this tissue compartment. We tested whether TGF-beta mediates collagen III expression by treating animals with TGF-beta panspecific monoclonal antibody, 1D11.16, administered i.p. shortly before irradiation. Radiation-induced collagen III staining in the adipose stroma was blocked in an antibody dose-dependent manner, which persisted through 7 days postirradiation. RNase protection assay revealed that radiation-induced elevation of total gland collagen III mRNA was also blocked by neutralizing antibody treatment. These data provide functional confirmation of the hypothesis that radiation exposure leads to latent TGF-beta activation, support our interpretation of the 8. Characterization of commercial proton exchange membrane materials after exposure to beta and gamma radiation Energy Technology Data Exchange (ETDEWEB) Thomson, S.N.; Carson, R.; Muirhead, C.; Li, H.; Castillo, I.; Boniface, H.; Suppiah, S. [Canadian Nuclear Laboratories, Chalk River, ON (Canada); Ratnayake, A.; Robinson, J. [Tyne Engineering Inc., Burlington, ON (Canada) 2015-03-15 Proton Exchange Membrane (PEM) type electrolysis cells have a potential use for tritium removal and heavy water upgrading. AECL is currently exposing various commercial PEM materials to both gamma (Cobalt-60 source) and beta (tritiated water) radiation to study the effects of radiation on these materials. This paper summarizes the testing methods and results that have been collected to date. The PEM materials that are or have been exposed to radiation are: Nafion 112, 212, 117 and 1110. Membrane characterization pre- and post- exposure consists of non-destructive inspection (FTIR, SEM/XPS), mechanical (tensile strength, percentage elongation, and modulus), electrical (resistance), or chemical (ion-exchange capacity - IEC). It has appeared that the best characterization techniques to compare exposed versus unexposed membranes were IEC, ultimate tensile strength and percent elongation. These testing techniques are easy and cheap to perform. The non-destructive tests, such as SEM and FTIR did not provide particularly useful information on radiation-induced degradation. Where changes in material properties were measured after radiation exposure, they would be expected to result in poorer cell performance. However, for modest γ-radiation exposure, all membranes showed a slight decrease in cell voltage (better performance). In contrast, the one β-radiation exposed membrane did show the expected increase in cell voltage. The counterintuitive trend for γ-radiation exposed membranes is not yet understood. Based on these preliminary results, it appears that γ- and β-radiation exposures have different effects. 9. A new approach to beta-gamma coincidence counting. Advance report on the Samar electronic system International Nuclear Information System (INIS) Carlos, J. E. de; Granados, C. E. 1972-01-01 In 4π β-γ coincidence measurements, precision on the evaluation of coincidence counting losses is made difficult because of complex overlapping effects between theβ--and γ-side dead times due to pre cursive counted events. In this context the SAMAR electronic system is aimed to give a precise way of automatic counting and reduce the need for calculated corrections. This report describes its configuration and basic features. The SAMAR has been conceived in such a manner that both beta and gamma chains are sharing a common and non extending dead-time which is simultaneously applied to both channels. The shared dead time is made to be the only one inserted throughout the chains. Overlapping effects vanish and the three counting channels have identical transmission ratios. A new dead-time circuit based on fast linear gates as blocking elements has been developed. Application of the two-oscillator Muller's method evidences a fully non-extending character. Automatism is implemented by using a live timer corrective channel controlling the counting scalers. (Author) 21 refs 10. Influence of beta radiation from tritium and gamma radiation from 60Co on the biological half-times of organically bound tritium International Nuclear Information System (INIS) Radwan, I. 1981-01-01 The influence of beta radiation from tritium on the biological half-times of organically bound tritium in particular tissues of the rat is compred with the influence of fractionated gamma radiation from 60 Co. (M.F.W.) 11. Use of gamma camera for measurement of the internal contamination with depleted uranium International Nuclear Information System (INIS) Spaic, R.; Markovic, S.; Pavlovic, S.; Pavlovic, R.; Ajdinovic, B.; Baskot, B.; Djurovic, B. 2000-01-01 Depleted uranium from radioactive wastes is used for manufacturing bullets used in Iraq, Republic of Serbia and Yugoslavia. These bullets are extremely dense and capable of penetrating heavily armored vehicles. Their medical importance lies in the fact that the bullets contain seventy percent depleted uranium which creates aerosolized particles less than five microns in diameter, small enough to be inhaled, after spontaneous bullet burn at impact. Nuclear medicine scientists must be aware of this and be prepared to measure internal contamination of persons exposed to this radioactive material. Whole body counters (WBC) represent appropriate equipment for this purpose but their availability in developing countries is not sufficient. Gamma camera is an alternative. The minimum detectable activity (MDA) of depleted uranium, iodine and technetium for gamma cameras was measured in this paper. Low energy X-ray 100 KeV with 20% windows are used for the depleted uranium detection. About 40% gamma emissions from depleted uranium fall within these limits. The activities measured (50-100 Bq) are about ten times higher then on WBC (5 Bq). This does not limit the use of gamma cameras for measurement of lung or whole body internal contamination with depleted uranium. (author) 12. A triple-crystal phoswich detector with digital pulse shape discrimination for alpha/beta/gamma spectroscopy International Nuclear Information System (INIS) White, Travis L.; Miller, William H. 1999-01-01 Researchers at the University of Missouri - Columbia have developed a three-crystal phoswich detector coupled to a digital pulse shape discrimination system for use in alpha/beta/gamma spectroscopy. Phoswich detectors use a sandwich of scintillators viewed by a single photomultiplier tube to simultaneously detect multiple types of radiation. Separation of radiation types is based upon pulse shape difference among the phosphors, which has historically been performed with analog circuitry. The system uses a GaGe CompuScope 1012, 12 bit, 10 MHz computer-based oscilloscope that digitally captures the pulses from a phoswich detector and subsequently performs pulse shape discrimination with cross-correlation analysis. The detector, based partially on previous phoswich designs by Usuda et al., uses a 10 mg/cm 2 thick layer of ZnS(Ag) for alpha detection, followed by a 0.254 cm CaF 2 (Eu) crystal for beta detection, all backed by a 2.54 cm NaI(Tl) crystal for gamma detection. Individual energy spectra and count rate information for all three radiation types are displayed and updated periodically. The system shows excellent charged particle discrimination with an accuracy of greater than 99%. Future development will include a large area beta probe with gamma-ray discrimination, systems for low-energy photon detection (e.g. Bremsstrahlung or keV-range photon emissions), and other health physics instrumentation 13. Gamma radiation effects on bacterial contamination and organoleptic characteristics of frozen Ponaeus Monodon International Nuclear Information System (INIS) Motamedi Sedeh, F.; Afsharian, R.; Zolfagarieh, H.; Nikbakht, M.; Shafaee, S. K.; Ayazi, M.; Fatolahi, H.; Moharami, A.; Babaee, M. 2010-01-01 The aim of this study was the application of irradiation process to decrease bacterial contamination of the penaeus monodon. The shrimp samples were obtained from Hormozgan and were sent to the microbiological laboratory. Bacterial contamination of shrimp were determined by counting the aerobic mesophil bacteria, Staphylococcus areus, Coliforms, Vibrio. parahaemolyticus and Salmonella. The shrimp samples were irradiated at different doses of gamma ray. Finally, the optimum dose of the gamma ray for bacterial decontamination of shrimp, especially of Vibrio Parahaemolyticus, was obtained to be 2 kGy. Also, the chemical factors of irradiated and non-irradiated samples such as Protein, Fat, total volatile Nitrogen, Non Protein Nitrogen, Peroxide Value and Amino Acids were measured. There were not any important difference among them. Also, there were not any significant difference between total volatile Nitrogen and Peroxide Value (P>0.05) for the irradiated and non-irradiated shrimp samples. Study of bacterial contaminations of the irradiated and non irradiated samples after 12 months showed that irradiation by 2 kGy can control the microbial contaminations. Four types of films for packaging: Pet.pe, Pp.pe, Bopp, and Pe.20 were used for storage of the irradiated and non irradiated shrimp samples in-18 d egree C during 12 months. All of the packages were studied on the aspects of color, odor, tissue and taste of shrimp samples and elasticity and pressing of packages. For the irradiated and non irradiated shrimp Pet.pe and Pp.pe were preferred, respectively. 14. Studies of. gamma. -ray irradiation effects on tris(. beta. -diketonato)iron(III) and cobalt(III) coordination compounds by means of Moessbauer spectroscopy and magnetic susceptibility measurements Energy Technology Data Exchange (ETDEWEB) Sakai, Y.; Endo, K.; Sano, H. (Tokyo Metropolitan Univ. (Japan). Faculty of Science) 1981-06-01 Both absorption Moessbauer spectroscopy and magnetic susceptibility measurements on tris(..beta..-diketonato)iron(III) and cobalt(III) compounds indicate that ligands which have phenyl group as a substituent are more stable to ..gamma..-ray radiolysis, in accordance with previous results of emission Moessbauer spectroscopic studies of /sup 57/Co-labelled tris (..beta..-diketonato)cobalt(III) compounds. 15. EPR and TL-based beta dosimetry measurements in various tooth components contaminated by 90Sr International Nuclear Information System (INIS) Veronese, I.; Fattibene, P.; Cantone, M.C.; De Coste, V.; Giussani, A.; Onori, S.; Shishkina, E.A. 2008-01-01 Thermoluminescence-based beta dosimetry, previously proposed for the estimate of the internal contamination in teeth, and EPR has been used in this paper to investigate the homogeneity of 90 Sr contamination and of dose within nine teeth of one person born in the year of the onset of waterborne radioactive releases of the Mayak plutonium facility. A large deviation of dose and activity distributions in both enamel and radical dentine of the various teeth was observed. Average dose was 27±7Gy in enamel and 0.90±0.31Gy in radical dentine. Average 90 Sr concentration was 52±8Bq/g in enamel and 5±2Bq/g in radical dentine. The observed deviation around the mean value of dose and 90 Sr concentration can be explained due to the specific mineral evolution of each tooth at the time of Sr intake. In the same donor, a negative correlation was also observed between radical dentine and enamel for the 90 Sr specific activity as well for the dose. Similar analyses performed on one massive molar belonging to a second donor revealed absence of correlation between dose and 90 Sr concentration in the same tissue, indicating a dose contribution from 90 Sr present in neighbouring tissue compartments. Systematic differences in cumulated dose and activity levels between the lingual and the buccal parts of crown dentine and of enamel were also observed 16. Radon-induced surface contaminations in neutrinoless double beta decay and dark matter experiments International Nuclear Information System (INIS) Pattavina, L. 2011-01-01 In experiments looking for rare events, like neutrinoless double beta decay (DBD0ν) and dark matter search (DM), one of the main issues is to increase the experimental sensitivity through the material selection and production. The background contribution coming from the materials used for the detector realization has to be minimized. Moreover the net reduction of the background produced by the bulk part of the apparatus has raised concerns about the background contribution coming from the surfaces. Many procedures and techniques were developed during the last years in order to remove and to minimize the presence of possible contaminants on detector surfaces. To succeed in this strategy a big effort was put in defining all possible mechanisms that lead to surface contaminations, as well as specific cleaning procedures, which are able to reduce and control the surface radioactivity. The presence in air and gases of possible radioactive elements that can stick on the detector surfaces can lead to a recontamination process that will vanish all the applied cleaning procedures. Here is presented and analyzed the contribution to the background of rare events experiments like CUORE experiment (DBD0ν) and EDELWEISS experiment (DM) produced by an exposure of their detector components to a big activity of 222 Rn, radioactive daughter isotope from the 238 U chain. (author) 17. Primary 4{pi}{beta}-{gamma} coincidence system for standardization of radionuclides by means of plastic scintillators; Sistema primario por coincidencias 4{pi}{beta}-{gamma} para a padronizacao de radionuclideos empregando cintiladores plasticos Energy Technology Data Exchange (ETDEWEB) Baccarelli, Aida Maria 2003-07-01 The present work describes a 4{pi}({alpha},{beta})-{gamma} coincidence system for absolute measurement of radionuclide activity using a plastic scintillator in 4{pi} geometry for charged particles detection and a Nal (Tl) crystal for gamma-ray detection. Several shapes and dimensions of the plastic scintillator have been tried in order to obtain the best system configuration. Radionuclides which decay by alpha emission, {beta}{sup -}, {beta}{sup +} and electron capture have been standardized. The results showed excellent agreement with other conventional primary system which makes use of a 4{pi} proportional counter for X-ray and charged particle detection. The system developed in the present work have some advantages when compared with the conventional systems, namely; it does not need metal coating on the films used as radioactive source holders. When compared to liquid scintillators, is showed the advantage of not needing to be kept in dark for more than 24 h to allow phosphorescence decay of ambient light. Therefore it can be set to count immediately after the sources are placed inside of it. (author) 18. Category-specific visual responses: an intracranial study comparing gamma, beta, alpha and ERP response selectivity Directory of Open Access Journals (Sweden) Juan R Vidal 2010-11-01 Full Text Available The specificity of neural responses to visual objects is a major topic in visual neuroscience. In humans, functional magnetic resonance imaging (fMRI studies have identified several regions of the occipital and temporal lobe that appear specific to faces, letter-strings, scenes, or tools. Direct electrophysiological recordings in the visual cortical areas of epileptic patients have largely confirmed this modular organization, using either single-neuron peri-stimulus time-histogram or intracerebral event-related potentials (iERP. In parallel, a new research stream has emerged using high-frequency gamma-band activity (50-150 Hz (GBR and low-frequency alpha/beta activity (8-24 Hz (ABR to map functional networks in humans. An obvious question is now whether the functional organization of the visual cortex revealed by fMRI, ERP, GBR, and ABR coincide. We used direct intracerebral recordings in 18 epileptic patients to directly compare GBR, ABR, and ERP elicited by the presentation of seven major visual object categories (faces, scenes, houses, consonants, pseudowords, tools, and animals, in relation to previous fMRI studies. Remarkably both GBR and iERP showed strong category-specificity that was in many cases sufficient to infer stimulus object category from the neural response at single-trial level. However, we also found a strong discrepancy between the selectivity of GBR, ABR, and ERP with less than 10% of spatial overlap between sites eliciting the same category-specificity. Overall, we found that selective neural responses to visual objects were broadly distributed in the brain with a prominent spatial cluster located in the posterior temporal cortex. Moreover, the different neural markers (GBR, ABR, and iERP that elicit selectivity towards specific visual object categories present little spatial overlap suggesting that the information content of each marker can uniquely characterize high-level visual information in the brain. 19. CD147 is a regulatory subunit of the gamma-secretase complex inAlzheimer's disease amyloid beta-peptide production Energy Technology Data Exchange (ETDEWEB) Zhou, Shuxia; Zhou, Hua; Walian, Peter J.; Jap, Bing K. 2005-04-06 {gamma}-secretase is a membrane protein complex that cleaves the {beta}-amyloid precursor protein (APP) within the transmembrane region, following prior processing by {beta}-secretase, producing amyloid {beta}-peptides (A{beta}{sub 40} and A{beta}{sub 42}). Errant production of A{beta}-peptides that substantially increases A{beta}{sub 42} production has been associated with the formation of amyloid plaques in Alzheimer's disease patients. Biophysical and genetic studies indicate that presenilin-1 (Psn-1), which contains the proteolytic active site, and three other membrane proteins, nicastrin (Nct), APH-1, and PEN-2 are required to form the core of the active {gamma}-secretase complex. Here, we report the purification of the native {gamma}-secretase complexes from HeLa cell membranes and the identification of an additional {gamma}-secretase complex subunit, CD147, a transmembrane glycoprotein with two immunoglobulin-like domains. The presence of this subunit as an integral part of the complex itself was confirmed through co-immunoprecipitation studies of the purified protein from HeLa cells and solubilized complexes from other cell lines such as neural cell HCN-1A and HEK293. Depletion of CD147 by RNA interference was found to increase the production of A{beta} peptides without changing the expression level of the other {gamma}-secretase components or APP substrates while CD147 overexpression had no statistically significant effect on amyloid {beta}-peptide production, other {gamma}-secretase components or APP substrates, indicating that the presence of the CD147 subunit within the {gamma}-secretase complex directly down-modulates the production of A{beta}-peptides. {gamma}-secretase was first recognized through its role in the production of the A{beta} peptides that are pathogenic in Alzheimer's disease (AD) (1). {gamma}-secretase is a membrane protein complex with unusual aspartyl protease activity that cleaves a variety of type I membrane proteins 20. Attenuation of beta and gamma oscillations in schizophrenia spectrum patients following hand posture perturbation DEFF Research Database (Denmark) Arnfred, Sidse M.; Mørup, Morten; Thalbitzer, Jørgen 2011-01-01 Several electroencephalographic (EEG) studies in schizophrenia report that the patients have reduced evoked gamma activity following visual and auditory stimulation. Somatosensory gamma activity has not previously been examined. It has been suggested that a dysfunction basic to schizophrenia spec... 1. Beta-and gamma-turns in proteins revisited: a new set of amino acid turn-type dependent positional preferences and potentials. Science.gov (United States) Guruprasad, K; Rajkumar, S 2000-06-01 The number of beta-turns in a representative set of 426 protein three-dimensional crystal structures selected from the recent Protein Data Bank has nearly doubled and the number of gamma-turns in a representative set of 320 proteins has increased over seven times since the previous analysis. Beta-turns (7153) and gamma-turns (911) extracted from these proteins were used to derive a revised set of type-dependent amino acid positional preferences and potentials. Compared with previous results, the preference for proline, methionine and tryptophan has increased and the preference for glutamine, valine, glutamic acid and alanine has decreased for beta-turns. Certain new amino acid preferences were observed for both turn types and individual amino acids showed turn-type dependent positional preferences. The rationale for new amino acid preferences are discussed in the light of hydrogen bonds and other interactions involving the turns. Where main-chain hydrogen bonds of the type NH(i + 3) --> CO(i) were not observed for some beta-turns, other main-chain hydrogen bonds or solvent interactions were observed that possibly stabilize such beta-turns. A number of unexpected isolated beta-turns with proline at i + 2 position were also observed. The NH(i + 2) --> CO(i) hydrogen bond was observed for almost all gamma-turns. Nearly 20% classic gamma-turns and 43% inverse gamma-turns are isolated turns. 2. Determination of gamma and-2 beta(s) from charmless two-body decays of beauty mesons NARCIS (Netherlands) Aaij, R.; Beteta, C. Abellan; Adeva, B.; Adinolfi, M.; Affolder, A.; Ajaltouni, Z.; Akar, S.; Albrecht, J.; Alessio, F.; Alexander, M.; Ali, S.; Alkhazov, G.; Cartelle, P. Alvarez; Alves, A. A.; Amato, S.; Amerio, S.; Amhis, Y.; An, L.; Anderlini, L.; Anderson, J.; Andreassen, R.; Andreotti, M.; Andrews, J. E.; Appleby, R. B.; Gutierrez, O. Aquines; Archilli, F.; Artamonov, A.; Artuso, M.; Aslanides, E.; Auriemma, G.; Baalouch, M.; Bachmann, S.; Back, J. J.; Badalov, A.; Baesso, C.; Baldini, W.; Barlow, R. J.; Barschel, C.; Barsuk, S.; Barter, W.; Batozskaya, V.; Battista, V.; Bay, A.; Beaucourt, L.; Beddow, J.; Bedeschi, F.; Bediaga, I.; Belogurov, S.; Belous, K.; Belyaev, I.; Ben-Haim, E.; Bencivenni, G.; Benson, S.; Benton, J.; Berezhnoy, A.; Bernet, R.; Bettler, M. -O.; van Beuzekom, M.; Bien, A.; Bifani, S.; Bird, T.; Bizzeti, A.; Bjornstad, P. M.; Blake, T.; Blanc, F.; Blouw, J.; Blusk, S.; Bocci, V.; Bondar, A.; Bondar, N.; Bonivento, W.; Borghi, S.; Borgia, A.; Borsato, M.; Bowcock, T. J. V.; Bowen, E.; Bozzi, C.; Brambach, T.; Bressieux, J.; Brett, D.; Britsch, M.; Britton, T.; Brodzicka, J.; Brook, N. H.; Brown, H.; Bursche, A.; Busetto, G.; Buytaert, J.; Cadeddu, S.; Calabrese, R.; Calvi, M.; Gomez, M. Calvo; Campana, P.; Perez, D. Campora; Carbone, A.; Carboni, G.; Cardinale, R.; Cardini, A.; Carson, L.; Akiba, K. Carvalho; Casse, G.; Cassina, L.; Garcia, L. Castillo; Cattaneo, M.; Cauet, Ch.; Cenci, R.; Charles, M.; Charpentier, Ph.; Chefdeville, M.; Chen, S.; Cheung, S. -F.; Chiapolini, N.; Chrzaszcz, M.; Ciba, K.; Vidal, X. Cid; Ciezarek, G.; Clarke, P. E. L.; Clemencic, M.; Cliff, H. V.; Closier, J.; Coco, V.; Cogan, J.; Cogneras, E.; Cojocariu, L.; Collins, P.; Comerma-Montells, A.; Contu, A.; Cook, A.; Coombes, M.; Coquereau, S.; Corti, G.; Corvo, M.; Counts, I.; Couturier, B.; Cowan, G. A.; Craik, D. C.; Torres, M. Cruz; Cunliffe, S.; Currie, R.; D'Ambrosio, C.; Dalseno, J.; David, P.; David, P. N. Y.; Davis, A.; De Bruyn, K.; De Capua, S.; De Cian, M.; De Miranda, J. M.; De Paula, L.; De Silva, W.; De Simone, P.; De camp, D.; Deckenhoff, M.; Del Buono, L.; Deleage, N.; Derkach, D.; Deschamps, O.; Dettori, F.; Di anto, A.; Dijkstra, H.; Donleavy, S.; Dordei, F.; Dorigo, M.; Suarez, A. Dosil; Dossett, D.; Dovbnya, A.; Dreimanis, K.; Dujany, G.; Dupertuis, F.; Durante, P.; Dzhelyadin, R.; Dziurda, A.; Dzyuba, A.; Easo, S.; Egorychev, V.; Eidelman, S.; Eisenhardt, S.; Eitschberger, U.; Ekelhof, R.; Eklund, L.; El Rifai, I.; Elsasser, Ch.; Ely, S.; Esen, S.; Evans, H. -M.; Evans, T.; Falabella, A.; Faerber, C.; Farinelli, C.; Farley, N.; Farry, S.; Fay, R. F.; Ferguson, D.; Albor, V. Fernandez; Rodrigues, F. Ferreira; Ferro-Luzzi, M.; Filippov, S.; Fiore, M.; Fiorini, M.; Firlej, M.; Fitzpatrick, C.; Fiutowski, T.; Fol, P.; Fontana, M.; Fontanelli, F.; Forty, R.; Francisco, O.; Frank, M.; Frei, C.; Frosini, M.; Fu, J.; Furfaro, E.; Torreira, A. Gallas; Galli, D.; Gallorini, S.; Gambetta, S.; Gandelman, M.; Gandini, P.; Gao, Y.; Pardinas, J. Garca; Garofoli, J.; Tico, J. Garra; Garrido, L.; Gaspar, C.; Gauld, R.; Gavardi, L.; Gavrilov, G.; Geraci, A.; Gersabeck, E.; Gersabeck, M.; Gershon, T.; Ghez, Ph.; Gianelle, A.; Giani, S.; Gibson, V.; Giubega, L.; Gligorov, V. V.; Goebel, C.; Golubkov, D.; Golutvin, A.; Gomes, A.; Gotti, C.; Gandara, M. Grabalosa; Diaz, R. Graciani; Cardoso, L. A. Granado; Grauges, E.; Graziani, G.; Grecu, A.; Greening, E.; Gregson, S.; Griffith, P.; Grillo, L.; Gruenberg, O.; Gui, B.; Gushchin, E.; Guz, Yu.; Gys, T.; Hadjivasiliou, C.; Haefeli, G.; Haen, C.; Haines, S. C.; Hall, S.; Hamilton, B.; Hampson, T.; Han, X.; Hansmann-Menzemer, S.; Harnew, N.; Harnew, S. T.; Harrison, J.; He, J.; Head, T.; Heijne, V.; Hennessy, K.; Henrard, P.; Henry, L.; Morata, J. A. Hernando; van Herwijnen, E.; Hess, M.; Hicheur, A.; Hill, D.; Hoballah, M.; Hombach, C.; Hulsbergen, W.; Hunt, P.; Hussain, N.; Hutchcroft, D.; Hynds, D.; Idzik, M.; Ilten, P.; Jacobsson, R.; Jaeger, A.; Jalocha, J.; Jans, E.; Jaton, P.; Jawahery, A.; Jing, F.; John, M.; Johnson, D.; Jones, C. R.; Joram, C.; Jost, B.; Jurik, N.; Kaballo, M.; Kandybei, S.; Kanso, W.; Karacson, M.; Karbach, T. M.; Karodia, S.; Kelsey, M.; Kenyon, I. R.; Ketel, T.; Khanji, B.; Khurewathanakul, C.; Klaver, S.; Klimaszewski, K.; Kochebina, O.; Kolpin, M.; Komarov, I.; Koopman, R. F.; Koppenburg, P.; Korolev, M.; Kozlinskiy, A.; Kravchuk, L.; Kreplin, K.; Kreps, M.; Krocker, G.; Krokovny, P.; Kruse, F.; Kucewicz, W.; Kucharczyk, M.; Kudryavtsev, V.; Kurek, K.; Kvaratskheliya, T.; La Thi, V. N.; Lacarrere, D.; Lafferty, G.; Lai, A.; Lambert, D.; Lambert, R. W.; Lanfranchi, G.; Langenbruch, C.; Langhans, B.; Latham, T.; Lazzeroni, C.; Le Gac, R.; van Leerdam, J.; Lees, J. -P.; Lefevre, R.; Leflat, A.; Lefrancois, J.; Leo, S.; Leroy, O.; Lesiak, T.; Leverington, B.; Li, Y.; Likhomanenko, T.; Liles, M.; Lindner, R.; Linn, C.; Lionetto, F.; Liu, B.; Lohn, S.; Longstaff, I.; Lopes, J. H.; Lopez-March, N.; Lowdon, P.; Lu, H.; Lucchesi, D.; Luo, H.; Lupato, A.; Luppi, E.; Lupton, O.; Machefert, F.; Machikhiliyan, I. V.; Maciuc, F.; Maev, O.; Malde, S.; Malinin, A.; Manca, G.; Mancinelli, G.; Mapelli, A.; Maratas, J.; Marchand, J. F.; Marconi, U.; Benito, C. Marin; Marino, P.; Maerki, R.; Marks, J.; Martellotti, G.; Martens, A.; Sanchez, A. Martn; Martinelli, M.; Santos, D. Martinez; Vidal, F. Martinez; Tostes, D. Martins; Massafferri, A.; Matev, R.; Mathe, Z.; Matteuzzi, C.; Mazurov, A.; McCann, M.; McCarthy, J.; Mcnab, A.; McNulty, R.; McSkelly, B.; Meadows, B.; Meier, F.; Meissner, M.; Merk, M.; Milanes, D. A.; Minard, M. -N.; Moggi, N.; Rodriguez, J. Molina; Monteil, S.; Morandin, M.; Morawski, P.; Morda, A.; Morello, M. J.; Moron, J.; Morris, A. -B.; Mountain, R.; Muheim, F.; Mueller, K.; Mussini, M.; Muster, B.; Naik, P.; Nakada, T.; Nandakumar, R.; Nasteva, I.; Needham, M.; Neri, N.; Neubert, S.; Neufeld, N.; Neuner, M.; Nguyen, A. D.; Nguyen, T. D.; Nguyen-Mau, C.; Nicol, M.; Niess, V.; Niet, R.; Nikitin, N.; Nikodem, T.; Novoselov, A.; O'Hanlon, D. P.; Oblakowska-Mucha, A.; Obraztsov, V.; Oggero, S.; Ogilvy, S.; Okhrimenko, O.; Oldeman, R.; Onderwater, G.; Orlandea, M.; Goicochea, J. M. Otalora; Owen, P.; Oyanguren, A.; Pal, B. K.; Palano, A.; Palombo, F.; Palutan, M.; Panman, J.; Papanestis, A.; Pappagallo, M.; Pappalardo, L. L.; Parkes, C.; Parkinson, C. J.; Passaleva, G.; Patel, G. D.; Patel, M.; Patrignani, C.; Alvarez, A. Pazos; Pearce, A.; Pellegrino, A.; Altarelli, M. Pepe; Perazzini, S.; Trigo, E. Perez; Perret, P.; Perrin-Terrin, M.; Pescatore, L.; Pesen, E.; Petridis, K.; Petrolini, A.; Olloqui, E. Picatoste; Pietrzyk, B.; Pilar, T.; Pinci, D.; Pistone, A.; Playfer, S.; Casasus, M. Plo; Polci, F.; Poluektov, A.; Polycarpo, E.; Popov, A.; Popov, D.; Popovici, B.; Potterat, C.; Price, E.; Price, J. D.; Prisciandaro, J.; Pritchard, A.; Prouve, C.; Pugatch, V.; Navarro, A. Puig; Punzi, G.; Qian, W.; Rachwal, B.; Rademacker, J. H.; Rakotomiaramanana, B.; Rama, M.; Rangel, M. S.; Raniuk, I.; Rauschmayr, N.; Raven, G.; Redi, F.; Reichert, S.; Reid, M. M.; dos Reis, A. C.; Ricciardi, S.; Richards, S.; Rihl, M.; Rinnert, K.; Molina, V. Rives; Robbe, P.; Rodrigues, A. B.; Rodrigues, E.; Perez, P. Rodriguez; Roiser, S.; Romanovsky, V.; Vidal, A. Romero; Rotondo, M.; Rouvinet, J.; Ruf, T.; Ruiz, H.; Valls, P. Ruiz; Silva, J. J. Saborido; Sagidova, N.; Sail, P.; Saitta, B.; Guimaraes, V. Salustino; Mayordomo, C. Sanchez; Sedes, B. Sanmartin; Santacesaria, R.; Rios, C. Santamarina; Santovetti, E.; Sarti, A.; Satriano, C.; Satta, A.; Saunders, D. M.; Savrie, M.; Savrina, D.; Schiller, M.; Schindler, H.; Schlupp, M.; Schmelling, M.; Schmidt, B.; Schneider, O.; Schopper, A.; Schune, M. -H.; Schwemmer, R.; Sciascia, B.; Sciubba, A.; Seco, M.; Semennikov, A.; Sepp, I.; Serra, N.; Serrano, J.; Sestini, L.; Seyfert, P.; Shapkin, M.; Shapoval, I.; Shcheglov, Y.; Shears, T.; Shekhtman, L.; Shevchenko, V.; Shires, A.; Coutinho, R. Silva; Simi, G.; Sirendi, M.; Skidmore, N.; Skwarnicki, T.; Smith, N. A.; Smith, E.; Smith, E.; Smith, J.; Smith, M.; Snoek, H.; Sokoloff, M. D.; Soler, F. J. P.; Soomro, F.; Souza, D.; De Paula, B. Souza; Spaan, B.; Sparkes, A.; Spradlin, P.; Sridharan, S.; Stagni, F.; Stah, M.; Stahl, S.; Steinkamp, O.; Stenyakin, O.; Stevenson, S.; Stoica, S.; Stone, S.; Storaci, B.; Stracka, S.; Straticiuc, M.; Straumann, U.; Stroili, R.; Subbiah, V. K.; Sun, L.; Sutcliffe, W.; Swientek, K.; Swientek, S.; Syropoulos, V.; Szczekowski, M.; Szczypka, P.; Szilard, D.; Szumlak, T.; T'Jampens, S.; Teklishyn, M.; Tellarini, G.; Teubert, F.; Thomas, C.; Thomas, E.; Vantilburg, J.; Tisserand, V.; Tobin, M.; Tolk, S.; Tomassetti, L.; Topp-Joergensen, S.; Torr, N.; Tournefier, E.; Tourneur, S.; Tran, M. T.; Tresch, M.; Tsaregorodtsev, A.; Tsopelas, P.; Tuning, N.; Garcia, M. Ubeda; Ukleja, A.; Ustyuzhanin, A.; Uwer, U.; Vacca, C.; Vagnoni, V.; Valenti, G.; Vallier, A.; Gomez, R. Vazquez; Regueiro, P. Vazquez; Sierra, C. Vazquez; Vecchi, S.; Velthuis, J. J.; Veltri, M.; Veneziano, G.; Vesterinen, M.; Viaud, B.; Vieira, D.; Diaz, M. Vieites; Vilasis-Cardona, X.; Vollhardt, A.; Volyanskyy, D.; Voong, D.; Vorobyev, A.; Vorobyev, V.; Voss, C.; Voss, H.; de Vries, J. A.; Waldi, R.; Wallace, C.; Wallace, R.; Walsh, J.; Wandernoth, S.; Wang, J.; Ward, D. R.; Watson, N. K.; Websdale, D.; Whitehead, M.; Wicht, J.; Wiedner, D.; Wilkinson, G.; Williams, M. P.; Williams, M.; Wilschut, H. W.; Wilson, F. F.; Wimberley, J.; Wishahi, J.; Wislicki, W.; Witek, M.; Wormser, G.; Wotton, S. A.; Wright, S.; Wyllie, K.; Xie, Y.; Xing, Z.; Xu, Z.; Yang, Z.; Yuan, X.; Yushchenko, O.; Zangoli, M.; Zavertyaev, M.; Zhang, L.; Zhang, W. C.; Zhang, Y.; Zhelezov, A.; Zhokhov, A.; Zhong, L.; Zvyagin, A. 2015-01-01 Using the latest LHCb measurements of time-dependent CP violation in the B-s(0) -> K+K- decay, a U-spin relation between the decay amplitudes of B-s(0) -> K+K- and B-0 -> p(+)p(-) decay processes allows constraints to be placed on the angle gamma of the unitarity triangle and on the B-s(0) mixing 3. Separate assessment of natural beta and gamma dose-rates with TL from α-Al2O3:C single-crystal chips International Nuclear Information System (INIS) Kalchgruber, R.; Wagner, G.A. 2006-01-01 A measurement procedure was developed for fast and separate assessment of beta and gamma dose-rates in natural sediments using highly sensitive α-Al 2 O 3 :C single-crystal chips. The dosemeters were buried for periods from two days to three weeks in sediments with different layer structure and homogeneity. For each measurement, a pair of dosemeters was buried, in order to assess beta and gamma dose-rates separately. One dosemeter was wrapped only in thin plastic foil to shield it from alpha radiation, thus measuring beta + gamma components. The second one, used for the gamma component only, was packed additionally in a 1mm copper container for absorption of beta radiation. For calibration, another set of dosemeters was buried in reference soil with a well-known dose-rate and similar content of radioactive nuclides. By comparing the thermally stimulated luminescence signals from the dosemeters the gamma dose-rate and also, by subtraction, the beta dose-rate in the unknown soil could be determined. The calculated uncertainties were 5-7% and 10%, respectively. The resulting dose-rates for homogeneous and inhomogeneous media were compared with the results obtained by Ge- and on-site NaI-gamma-ray spectrometry. An agreement within 2σ-error limits was found for homogeneous media after only few days of exposure 4. Endogenous PKI gamma limits the duration of the anti-apoptotic effects of PTH and beta-adrenergic agonists in osteoblasts. Science.gov (United States) Chen, Xin; Song, In-Hwan; Dennis, James E; Greenfield, Edward M 2007-05-01 PKI gamma knockdown substantially extended the anti-apoptotic effects of PTH and beta-adrenergic agonists, whereas PKI gamma overexpression decreased these effects. Therefore, inhibition of PKI gamma activity may provide a useful co-therapy in combination with intermittent PTH or beta-adrenergic agonists for bone loss in conditions such as osteoporosis. PTH has both catabolic and anabolic effects on bone, which are primarily caused by cAMP/protein kinase A (PKA) signaling and regulation of gene expression. We previously showed that protein kinase inhibitor-gamma (PKI gamma) is required for efficient termination of cAMP/PKA signaling and gene expression after stimulation with PTH or beta-adrenergic agonists. Inhibition of osteoblast apoptosis is thought to be an important, but transient, mechanism partly responsible for the anabolic effects of intermittent PTH. Therefore, we hypothesized that endogenous PKI gamma also terminates the anti-apoptotic effect of PTH. PKI gamma knockdown by antisense transfection or siRNA was used to examine the ability of endogenous PKI gamma to modulate the anti-apoptotic effects of PTH and beta-adrenergic agonists in ROS 17/2.8 cells. Knockdown of PKI gamma substantially extended the anti-apoptotic effects of PTH, whether apoptosis was induced by etoposide or dexamethasone. In contrast, overexpression of PKI gamma decreased the anti-apoptotic effect of PTH pretreatment. This study is also the first demonstration that beta-adrenergic agonists mimic the anti-apoptotic effects of PTH in osteoblasts. Moreover, PKI gamma knockdown also substantially extended this anti-apoptotic effect of beta-adrenergic agonists. Taken together, these results show that endogenous PKI gamma limits the duration of the anti-apoptotic effects of cAMP/PKA signaling in osteoblasts. Because significant individual variability exists in the anabolic responses to PTH therapy in current clinical treatment of osteoporosis, inhibition of PKI gamma activity may provide a 5. Contribution to the study of {beta} disintegration and of nuclear structure using experiments on certain {beta}-{gamma} cascades: 198{sub Au}, 86{sub Rb}, 170{sub Tm}; Contribution a l'etude de la desintegration beta et a l'etude de la structure nucleaire a l'aide d'experiences sur certaines cascades beta-gamma: 198{sub Au}, 86{sub Rb}, 170{sub Tm} Energy Technology Data Exchange (ETDEWEB) Lachkar, J. [Commissariat a l' Energie Atomique, Bruyeres-le-Chatel (France). Centre d' Etudes; Paris-11 Univ., fabulte des Sciences 91 - Orsay (France) 1969-07-01 {beta}{gamma} directional angular correlations and shapes of inner beta spectra leading to the first excited level of the final nucleus enable one to determine the nuclear matrix elements typical of the {beta} transition. In the three observed first forbidden cases: {sup 170}Tm, {sup 86}Rb, {sup 198}Au, these matrix elements do not confirm the independent shell model theory. Other hypotheses are then suggested and discussed. (author) [French] Les experiences de correlation angulaire {beta}{gamma} et l'etude du spectre {beta} conduisant au premier niveau excite du noyau final permettent de determiner les elements de matrices nucleaires caracteristiques de cette transition. Dans les trois cas etudies (transitions une fois interdites): {sup 170}Tm, {sup 86}Rb, {sup 198}Au, ces elements de matrices ne peuvent etre retrouves a l'aide du modele en couches et a particules independantes. D'autres hypotheses sont alors emises et discutees. (auteur) 6. Contribution to the study of {beta} disintegration and of nuclear structure using experiments on certain {beta}-{gamma} cascades: 198{sub Au}, 86{sub Rb}, 170{sub Tm}; Contribution a l'etude de la desintegration beta et a l'etude de la structure nucleaire a l'aide d'experiences sur certaines cascades beta-gamma: 198{sub Au}, 86{sub Rb}, 170{sub Tm} Energy Technology Data Exchange (ETDEWEB) Lachkar, J [Commissariat a l' Energie Atomique, Bruyeres-le-Chatel (France). Centre d' Etudes; Paris-11 Univ., fabulte des Sciences 91 - Orsay (France) 1969-07-01 {beta}{gamma} directional angular correlations and shapes of inner beta spectra leading to the first excited level of the final nucleus enable one to determine the nuclear matrix elements typical of the {beta} transition. In the three observed first forbidden cases: {sup 170}Tm, {sup 86}Rb, {sup 198}Au, these matrix elements do not confirm the independent shell model theory. Other hypotheses are then suggested and discussed. (author) [French] Les experiences de correlation angulaire {beta}{gamma} et l'etude du spectre {beta} conduisant au premier niveau excite du noyau final permettent de determiner les elements de matrices nucleaires caracteristiques de cette transition. Dans les trois cas etudies (transitions une fois interdites): {sup 170}Tm, {sup 86}Rb, {sup 198}Au, ces elements de matrices ne peuvent etre retrouves a l'aide du modele en couches et a particules independantes. D'autres hypotheses sont alors emises et discutees. (auteur) 7. Fully automated gamma spectrometry gauge observing possible radioactive contamination of melting-shop samples International Nuclear Information System (INIS) Kroos, J.; Westkaemper, G.; Stein, J. 1999-01-01 At Salzgitter AG, several monitoring systems have been installed to check the scrap transport by rail and by car. At the moment, the scrap transport by ship is reloaded onto wagons for monitoring afterwards. In the future, a detection system will be mounted onto a crane for a direct check on scrap upon the departure of ship. Furthermore, at Salzgitter AG Central Chemical Laboratory, a fully automated gamma spectrometry gauge is installed in order to observe a possible radioactive contamination of the products. The gamma spectrometer is integrated into the automated OE spectrometry line for testing melting shop samples after performing the OE spectrometry. With this technique the specific activity of selected nuclides and dose rate will be determined. The activity observation is part of the release procedure. The corresponding measurement data are stored in a database for quality management reasons. (author) 8. Study of radiation detectors response in standard X, gamma and beta radiation standard beams; Estudo da resposta de monitores de radioprotecao em feixes padronizados de radiacao X, gama e beta Energy Technology Data Exchange (ETDEWEB) Nonato, Fernanda Beatrice Conceicao 2010-07-01 The response of 76 Geiger-Mueller detectors, 4 semiconductor detectors and 34 ionization chambers were studied. Many of them were calibrated with gamma radiation beams ({sup 37}Cs and {sup 60}Co), and some of them were tested in beta radiation ({sup 90}Sr+{sup 9'}0Y e {sup 204}Tl) and X radiation (N-60, N-80, N-100, N-150) beams. For all three types of radiation, the calibration factors of the instruments were obtained, and the energy and angular dependences were studied. For beta and gamma radiation, the angular dependence was studied for incident radiation angles of 0 deg and +- 45 deg. The curves of the response of the instruments were obtained over an angle interval of 0 deg to +- 90 deg, for gamma, beta and X radiations. The calibration factors obtained for beta radiation were compared to those obtained for gamma radiation. For gamma radiation, 24 of the 66 tested Geiger-Mueller detectors presented results for the energy dependence according to international recommendation of ISO 4037-2 and 56 were in accordance with the Brazilian ABNT 10011 recommendation. The ionization chambers and semiconductors were in accordance to national and international recommendations. All instruments showed angular dependence less than 40%. For beta radiation, the instruments showed unsatisfactory results for the energy dependence and angular dependence. For X radiation, the ionization chambers presented results for energy dependence according to the national recommendation, and the angular dependence was less than 40%. (author) 9. Study of radiation detectors response in standard X, gamma and beta radiation standard beams; Estudo da resposta de monitores de radioprotecao em feixes padronizados de radiacao X, gama e beta Energy Technology Data Exchange (ETDEWEB) Nonato, Fernanda Beatrice Conceicao 2010-07-01 The response of 76 Geiger-Mueller detectors, 4 semiconductor detectors and 34 ionization chambers were studied. Many of them were calibrated with gamma radiation beams ({sup 37}Cs and {sup 60}Co), and some of them were tested in beta radiation ({sup 90}Sr+{sup 9'}0Y e {sup 204}Tl) and X radiation (N-60, N-80, N-100, N-150) beams. For all three types of radiation, the calibration factors of the instruments were obtained, and the energy and angular dependences were studied. For beta and gamma radiation, the angular dependence was studied for incident radiation angles of 0 deg and +- 45 deg. The curves of the response of the instruments were obtained over an angle interval of 0 deg to +- 90 deg, for gamma, beta and X radiations. The calibration factors obtained for beta radiation were compared to those obtained for gamma radiation. For gamma radiation, 24 of the 66 tested Geiger-Mueller detectors presented results for the energy dependence according to international recommendation of ISO 4037-2 and 56 were in accordance with the Brazilian ABNT 10011 recommendation. The ionization chambers and semiconductors were in accordance to national and international recommendations. All instruments showed angular dependence less than 40%. For beta radiation, the instruments showed unsatisfactory results for the energy dependence and angular dependence. For X radiation, the ionization chambers presented results for energy dependence according to the national recommendation, and the angular dependence was less than 40%. (author) 10. Thermoluminescent characterization of thin films of aluminium oxide submitted to beta and gamma radiation; Caracterizacion termoluminiscente de peliculas delgadas de oxido de aluminio sometidas a radiacion beta y gamma Energy Technology Data Exchange (ETDEWEB) Villagran, E.; Escobar A, L.; Camps, E.; Gonzalez, P.R.; Martinez A, L. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico) 2002-07-01 By mean of the laser ablation technique, thin films of aluminium oxide have been deposited on kapton substrates. These films present thermoluminescent response (Tl) when they are exposed to beta and gamma radiation. The brilliance curves show two peaks between 112 C and 180 C. A dose-response relationship study was realized and the Tl kinetic parameters were determined using the computerized deconvolution of the brilliance curve (CGCD). The thin films of aluminium oxide have potential applications as ultra.thin radiation dosemeters. (Author) 11. Circadian rhythms, Wnt/beta-catenin pathway and PPAR alpha/gamma profiles in diseases with primary or secondary cardiac dysfunction Directory of Open Access Journals (Sweden) Yves eLecarpentier 2014-11-01 Full Text Available Circadian clock mechanisms are far-from-equilibrium dissipative structures. Peroxisome proliferator-activated receptors (PPAR alpha, beta/delta and gamma play a key role in metabolic regulatory processes, particularly in heart muscle. Links between circadian rhythms (CRs and PPARs have been established. Mammalian CRs involve at least two critical transcription factors, CLOCK and BMAL1 (Gekakis et al., 1998; Hogenesch et al., 1998. PPAR gamma plays a major role in both glucose and lipid metabolisms and presents circadian properties which coordinate the interplay between metabolism and CRs. PPAR gamma is a major component of the vascular clock. Vascular PPAR gamma is a peripheral regulator of cardiovascular rhythms controlling circadian variations in blood pressure and heart rate through BMAL1. We focused our review on diseases with abnormalities of CRs and with primary or secondary cardiac dysfunction. Moreover, these diseases presented changes in the Wnt/beta-catenin pathway and PPARs, according to two opposed profiles. Profile 1 was defined as follows: inactivation of the Wnt/beta-catenin pathway with increased expression of PPAR gamma. Profile 2 was defined as follows: activation of the Wnt/beta-catenin pathway with decreased expression of PPAR gamma. A typical profile 1 disease is arrhythmogenic right ventricular cardiomyopathy, a genetic cardiac disease which presents mutations of the desmosomal proteins and is mainly characterized by fatty acid accumulation in adult cardiomyocytes mainly in the right ventricle. The link between PPAR gamma dysfunction and desmosomal genetic mutations occurs via inactivation of the Wnt/beta-catenin pathway presenting oscillatory properties. A typical profile 2 disease is type 2 diabetes, with activation of the Wnt/beta-catenin pathway and decreased expression of PPAR gamma. CRs abnormalities are present in numerous pathologies such as cardiovascular diseases, sympathetic/parasympathetic dysfunction 12. Computer assisted collimation gamma camera: A new approach to imaging contaminated tissues International Nuclear Information System (INIS) Quartuccio, M.; Franck, D.; Pihet, P.; Begot, S.; Jeanguillaume, C. 2000-01-01 Measurement systems with the capability of imaging tissues contaminated with radioactive materials would find relevant applications in medical physics research and possibly in health physics. The latter in particular depends critically on the performance achieved for sensitivity and spatial resolution. An original approach of computer assisted collimation gamma camera (French acronym CACAO) which could meet suitable characteristics has been proposed elsewhere. CACAO requires detectors with high spatial resolution. The present work was aimed at investigating the application of the CACAO principle on a laboratory testing bench using silicon detectors made of small pixels. (author) 13. Computer assisted collimation gamma camera: A new approach to imaging contaminated tissues Energy Technology Data Exchange (ETDEWEB) Quartuccio, M.; Franck, D.; Pihet, P.; Begot, S.; Jeanguillaume, C 2000-07-01 Measurement systems with the capability of imaging tissues contaminated with radioactive materials would find relevant applications in medical physics research and possibly in health physics. The latter in particular depends critically on the performance achieved for sensitivity and spatial resolution. An original approach of computer assisted collimation gamma camera (French acronym CACAO) which could meet suitable characteristics has been proposed elsewhere. CACAO requires detectors with high spatial resolution. The present work was aimed at investigating the application of the CACAO principle on a laboratory testing bench using silicon detectors made of small pixels. (author) 14. Influence of gamma radiation on productivity parameters of chicken fed mycotoxin-contaminated corn International Nuclear Information System (INIS) Simas, Monica M.S.; Albuquerque, Ricardo; Oliveira, Carlos A.; Rottinghaus, George E.; Correa, Benedito 2010-01-01 The aim of this study was to evaluate productivity parameters and carcass yield of broiler chickens fed irradiated corn contaminated with mycotoxins. For this purpose, 180 one-day-old male chicks were divided into nine treatments and fed for 42 days. The results indicated that irradiation of corn with 5 kGy improved the productivity parameters studied. Therefore, gamma radiation may become an alternative for the control of the deleterious effects of mycotoxins on broiler chickens, which cause marked economic losses for rural producers. 15. Effect of gamma irradiation on microbial contamination and volatile oils of spices International Nuclear Information System (INIS) Singh, Rita; Tak, B.B. 1997-01-01 The effect of different doses of gamma irradiation, viz., 6, 10 and 14 kGy on the microbial contamination and the volatile oil content of coriander whole, coriander ground and cumin was studied. Exposure to 10 kGy was effective in the decontamination of spices. Fungi and coliforms in spices were inactivated on irradiation to a dose of 6 kGy. No significant change in the GC volatile profile of the irradiated spices was observed. (author). 3 refs., 1 fig., 1 tab 16. Approaches to contamination problems of agricultural land using Na(I) Tl spectrometer and gamma camera International Nuclear Information System (INIS) Yin, Yong-Gen; Suzui, Nobuo; Kawachi, Naoki; Ishii, Satomi; Fujimaki, Shu; Yamaguchi, Mitsutaka; Tanoi, Keitaro; Nakanishi, Tomoko M.; Chino, Mitsuo; Nakamura, Shin-ichi; Watabe, Hiroshi; Yamamoto, Seiichi 2012-01-01 The severe accident of Fukushima Daiichi Nuclear Power Plant made a large area of agricultural land contaminated with radioactive cesium (Cs-134 and 137). Quantitative analysis for radioactivity (discriminating for Cs-134 and Cs-137) taken in vegetables from the land was carried out using NaI (Tl) scintillation spectrometer. Development of gamma camera for their imaging due to Cs 137 was performed. The shape of the peaks in the spectrum, baseline suppression, a solution of lines overlapping, enhancement of high-resolution were studied. Furthermore, the effect of water on cesium absorbing and transferring process from the root to the tissue was studied. (S. Ohno) 17. Influence of gamma radiation on productivity parameters of chicken fed mycotoxin-contaminated corn Energy Technology Data Exchange (ETDEWEB) Simas, Monica M.S., E-mail: monicamssimas@yahoo.com.b [Microbiology Department, Biomedical Sciences Institute, University of Sao Paulo, Av. Prof. Lineu Prestes, 1374, Sao Paulo 05508-900 (Brazil); Albuquerque, Ricardo, E-mail: ricalbuq@usp.b [Nutrition and Animal Production Department, College of Veterinary Medicine, University of Sao Paulo, Av. Duque de Caxias Norte, 225 Pirassununga, Sao Paulo 13695-900 (Brazil); Oliveira, Carlos A., E-mail: carlosaf@usp.b [Food Science Department, College of Food Science, University of Sao Paulo, Av. Duque de Caxias Norte, 225, Pirassununga, Sao Paulo 13695-900 (Brazil); Rottinghaus, George E., E-mail: rottinghausg@missouri.ed [College of Veterinary Medicine, University of Missouri, 1600 East Rollins, Columbia, MO 65211 (United States); Correa, Benedito, E-mail: correabe@usp.b [Microbiology Department, Biomedical Sciences Institute, University of Sao Paulo, Av. Prof. Lineu Prestes, 1374, Sao Paulo 05508-900 (Brazil) 2010-10-15 The aim of this study was to evaluate productivity parameters and carcass yield of broiler chickens fed irradiated corn contaminated with mycotoxins. For this purpose, 180 one-day-old male chicks were divided into nine treatments and fed for 42 days. The results indicated that irradiation of corn with 5 kGy improved the productivity parameters studied. Therefore, gamma radiation may become an alternative for the control of the deleterious effects of mycotoxins on broiler chickens, which cause marked economic losses for rural producers. 18. Determination of contaminants in rare earth materials by prompt gamma activation analysis (PGAA) International Nuclear Information System (INIS) Perry, D.L.; English, G.A.; Firestone, R.B.; Molnar, G.L.; Revay, Zs. 2005-01-01 Prompt gamma activation analysis (PGAA) has been used to detect and quantify impurities in the analyses of rare earth (RE) oxides. The analytical results are discussed with respect to the importance of having a thorough identification and contaminant elements in these compounds regarding the function of the materials in their various applications. Also, the importance of using PGAA to analyze materials in support of other physico-chemical studies of the materials is discussed, including the study of extremely low concentrations of ions - such as the rare earth ions themselves - in bulk material matrices. (author) 19. Radioactive food and environment contamination International Nuclear Information System (INIS) Yousif, A.M. 2001-01-01 The Food and Environment Control Centre of Abu Dhabi Municipality with the help of IAEA has established facilities for regular monitoring of food and environmental samples for radioactive contamination. The Centre is now capable of measuring gamma, beta as well as alpha activity in different types of samples. The main activities in the area of food monitoring are as follows: General monitoring of food gamma radionuclides in foodstuffs by high resolution gamma spectrometry; Determination of specific gamma radionuclides in foodstuffs by high resolution gamma spectrometry; Radiochemical determination of Sr-90 using liquid scintillation analyzer or by gas flow proportional counter; Measurement of gross alpha activity in drinking water 20. A protocol for the calibration of gamma cameras to estimate internal contamination in emergency situations International Nuclear Information System (INIS) Dantas, B.M.; Lucena, E.A.; Dantas, A.L.A.; Araujo, F.; Melo, D.; Rebelo, A.M.O.; Teran, M.; Paolino, A.; Hermida, J.C.; Rojo, A.M.; Puerta, J.A.; Morales, J.; Bejerano, G.M.L.; Alfaro, M.; Ruiz, M.A.; Videla, R.; Pinones, O.; Gonzalez, S.; Navarro, T.; Cruz-Suarez, R. 2007-01-01 The concern about accidents involving radioactive materials has led to the search of alternative methods to quickly identify and quantify radionuclides in workers and in the population. One of the options to face up an eventual demand for mass monitoring of internal contamination is the use of a nuclear medicine diagnostic equipment known as gamma camera, a device used to scan patients who have been administered specific amounts of radioactive materials for medical purposes. Although the gamma camera is used for image diagnosis, it can be calibrated with anthropomorphic phantoms or point sources for the quantification of radionuclide activities in the human body. This work presents a protocol for the calibration of gamma cameras for such application. In order to evaluate the suitability of this type of equipment, a gamma camera available in a public hospital located in Rio de Janeiro was calibrated for the in vivo measurement of 131 I. The calibration includes the determination of detection efficiencies and minimum detectable activities for each radionuclide. The results show that the gamma camera presents enough sensitivity to detect activity levels corresponding to effective doses below 1 mSv. The protocol is the basis to establish a network of Nuclear Medicine Centres, located in public hospitals in eight countries of Latin America (Argentina, Brazil, Colombia, Cuba, Chile, Mexico, Peru and Uruguay) and in Spain that could be requested to collaborate in remediation actions in the event of an accident involving incorporation of radioactive materials. This protocol is one of the most significant outputs of the IAEA-ARCAL Project (RLA/9/049-LXXVIII) aimed to the Harmonization of Internal Dosimetry Procedures. (authors) 1. A protocol for the calibration of gamma cameras to estimate internal contamination in emergency situations Energy Technology Data Exchange (ETDEWEB) Dantas, B.M.; Lucena, E.A.; Dantas, A.L.A.; Araujo, F.; Melo, D. [Instituto de Radioprotecao e Dosimetria, CNEN, Av. Salvador Allende s/n, Rio de Janeiro (Brazil); Rebelo, A.M.O. [University Hospital, Nuclear Medicine Center, Rio de Janeiro (Brazil); Teran, M.; Paolino, A. [Facultad de Quimica, Montevideo (Uruguay); Hermida, J.C. [Hospital de Clinicas, Facultad de Medicina, Montevideo (Uruguay); Rojo, A.M. [Autoridad Regulatoria Nuclear, Buenos Aires (Argentina); Puerta, J.A.; Morales, J. [Universidad Nacional de Colombia, Medellin (Colombia); Bejerano, G.M.L. [Centro de Proteccion e Higiene de las Radiaciones, Ciudad de la Habana (Cuba); Alfaro, M.; Ruiz, M.A. [Instituto Nacional de Investigaciones Nucleares, Ocoyoacac (Mexico); Videla, R.; Pinones, O. [Comision Chilena de Energia Nuclear, Santiago (Chile); Gonzalez, S. [Instituto Peruano de Energia Nuclear, Lima (Peru); Navarro, T. [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas, Madrid (Spain); Cruz-Suarez, R. [International Atomic Energy Agency, Vienna (Austria) 2007-07-01 The concern about accidents involving radioactive materials has led to the search of alternative methods to quickly identify and quantify radionuclides in workers and in the population. One of the options to face up an eventual demand for mass monitoring of internal contamination is the use of a nuclear medicine diagnostic equipment known as gamma camera, a device used to scan patients who have been administered specific amounts of radioactive materials for medical purposes. Although the gamma camera is used for image diagnosis, it can be calibrated with anthropomorphic phantoms or point sources for the quantification of radionuclide activities in the human body. This work presents a protocol for the calibration of gamma cameras for such application. In order to evaluate the suitability of this type of equipment, a gamma camera available in a public hospital located in Rio de Janeiro was calibrated for the in vivo measurement of {sup 131}I. The calibration includes the determination of detection efficiencies and minimum detectable activities for each radionuclide. The results show that the gamma camera presents enough sensitivity to detect activity levels corresponding to effective doses below 1 mSv. The protocol is the basis to establish a network of Nuclear Medicine Centres, located in public hospitals in eight countries of Latin America (Argentina, Brazil, Colombia, Cuba, Chile, Mexico, Peru and Uruguay) and in Spain that could be requested to collaborate in remediation actions in the event of an accident involving incorporation of radioactive materials. This protocol is one of the most significant outputs of the IAEA-ARCAL Project (RLA/9/049-LXXVIII) aimed to the Harmonization of Internal Dosimetry Procedures. (authors) 2. Low-level multicounter {beta}/{gamma} systems with external guards in surface and shallow underground laboratories Energy Technology Data Exchange (ETDEWEB) Theodorsson, P [Iceland Univ. (Iceland). Science Inst. 1997-03-01 When weak samples are measured it is important that they can be given ample counting time in order to obtain satisfactory accuracy and that the background count rate can be checked well. This calls for a high counting capacity, which multidetectors can bring us. I will discuss development possibilities of low-level {beta}/{gamma} multidetector systems with an external anticosmic shield that will in many cases be operated in underground laboratories. These simple and low-cost system can frequently help us in increasing the number of detectors. Three concepts are combined in these systems: (1) multidetectors, (2) an external anticosmic (or guard) detector arrangement and (3) overburden shielding. (orig.) 3. Influence of heat treatment in {beta} and {gamma} phases on the microscopic structure of uranium; Influence des traitements thermiques en phases {beta} et {gamma} sur la structure micrographique de l'uranium Energy Technology Data Exchange (ETDEWEB) Robillard, A 1958-06-02 A new method of microscopic examination of uranium is described. Electrolytic polishing and etching are carried out in an acetic acid-chromic acid bath. Atmospheric or anodic oxidation of the polished surface produces films which follow exactly changes in the structure of the underlying metal. This method is very sensitive to small variations of orientation in polygonized crystals. Using this method of examination of uranium, it was found that annealing U in the {gamma} phase followed by a cooling at a rate dependent of the annealing temperature, causes the formation of substructures different from those due to the polygonization of {alpha}-U. The substructures are indicated by the concentration of impurities on the dislocations induced by the stresses accompanying the allotropic transformation {gamma} {yields} {beta}. Similar treatment of the U-1.4% Cr alloy in which the {beta} phase is stabilized at room temperature, confirms this explanation. In addition to the polygonization substructures, sharp discontinuities can be observed in the network of sub- boundaries as a fine white edging. The comparison of these with the structure revealed by thermal etching in vacuum suggest that there are traces of the grain boundaries of the {gamma} phase. The method of etching followed by oxidation shows a haloed phase identified as UH{sub 3}. The conditions of appearance and disappearance of this phase are studied. The sensitivity of this method of detecting the last traces of H in U is very high. The dependence of the hydrogen content on the tensile properties of uranium metal was also studied. (author) [French] Une methode nouvelle d'examen micrographique de l'uranium a ete mise au point. Le polissage electrolytique et le 'gravage' sont effectues dans un bain acide acetique-acide chromique. L'oxydation atmospherique ou anodique de la surface polie conduit a la formation de couches epitaxiques d'oxyde. Cette methode est particulierement sensible aux faibles variations d 4. Influence of heat treatment in {beta} and {gamma} phases on the microscopic structure of uranium; Influence des traitements thermiques en phases {beta} et {gamma} sur la structure micrographique de l'uranium Energy Technology Data Exchange (ETDEWEB) Robillard, A 1958-06-02 A new method of microscopic examination of uranium is described. Electrolytic polishing and etching are carried out in an acetic acid-chromic acid bath. Atmospheric or anodic oxidation of the polished surface produces films which follow exactly changes in the structure of the underlying metal. This method is very sensitive to small variations of orientation in polygonized crystals. Using this method of examination of uranium, it was found that annealing U in the {gamma} phase followed by a cooling at a rate dependent of the annealing temperature, causes the formation of substructures different from those due to the polygonization of {alpha}-U. The substructures are indicated by the concentration of impurities on the dislocations induced by the stresses accompanying the allotropic transformation {gamma} {yields} {beta}. Similar treatment of the U-1.4% Cr alloy in which the {beta} phase is stabilized at room temperature, confirms this explanation. In addition to the polygonization substructures, sharp discontinuities can be observed in the network of sub- boundaries as a fine white edging. The comparison of these with the structure revealed by thermal etching in vacuum suggest that there are traces of the grain boundaries of the {gamma} phase. The method of etching followed by oxidation shows a haloed phase identified as UH{sub 3}. The conditions of appearance and disappearance of this phase are studied. The sensitivity of this method of detecting the last traces of H in U is very high. The dependence of the hydrogen content on the tensile properties of uranium metal was also studied. (author) [French] Une methode nouvelle d'examen micrographique de l'uranium a ete mise au point. Le polissage electrolytique et le 'gravage' sont effectues dans un bain acide acetique-acide chromique. L'oxydation atmospherique ou anodique de la surface polie conduit a la formation de couches epitaxiques d'oxyde. Cette methode est particulierement sensible 5. Electronic, optical and transport properties of {alpha}-, {beta}- and {gamma}-phases of spinel indium sulphide: An ab initio study Energy Technology Data Exchange (ETDEWEB) Sharma, Yamini, E-mail: sharma.yamini62@gmail.com [Department of Physics, Feroze Gandhi College, Rae Bareli 229001, U.P. (India); Srivastava, Pankaj [Department of Physics, Feroze Gandhi College, Rae Bareli 229001, U.P. (India) 2012-08-15 Spinel indium sulphide exists in three phases. The tetragonal {beta}-phase transforms to the cubic {alpha}-phase at 420 Degree-Sign C which further transforms to the trigonal {gamma}-phase at 754 Degree-Sign C. Due to wide energy bandgap, the phases of indium sulphide have possibilities of applications in photo-electrochemical solar cell devices as a replacement of toxic CdS. The electronic, optical and transport properties of the three phases have therefore been investigated using full potential linear augmented plane wave (FP-LAPW) + local orbitals (lo) scheme, in the framework of density functional theory (DFT) with generalized gradient approximation (GGA) for the purpose of exchange-correlation energy functional. We present the structure, energy bands and density of states (DOS) for {alpha}-, {beta}- and {gamma}-phases. The partial density of states (PDOS) of {beta}-In{sub 2}S{sub 3} is in good agreement with experiment and earlier ab initio calculations. To obtain the fundamental characteristics of these phases we have analysed their linear optical properties such as the dynamic dielectric function in the energy range of 0-15 eV. From the dynamic dielectric function it is seen that there is no directional anisotropy for {alpha}-phase since the longitudinal and transverse components are almost identical, however the {beta} and {gamma}-phases show birefringence. The optical absorption profiles clearly indicate that {beta}-phase has possibility of greater multiple direct and indirect interband transitions in the visible regions compared to the other phases. To study the existence of interesting thermoelectric properties, transport properties like electrical and thermal conductivities, Seebeck and Hall coefficients etc. are also calculated. Good agreements are found with the available experimental results. -- Highlights: Black-Right-Pointing-Pointer The electronic properties of phases of In{sub 2}S{sub 3} have been investigated. Black-Right-Pointing-Pointer The 6. Principles of medical rehabilitation of survivors of acute radiation sickness induced by gamma and beta and gumma and neutron radiation Energy Technology Data Exchange (ETDEWEB) Nedejina, N.M.; Galstian, I.A.; Savitsky, A.A.; Sachkov, A.V.; Rtisheva, J.N.; Uvatcheva, I.V.; Filin, S.V. [State Research Center of Russia, Moscow (Russian Federation). Inst. of Biophysics 2000-05-01 The purpose of this study is to reveal the principles of medical rehabilitation different degree acute radiation syndrome (ARS) survivors, who exposed {gamma}{beta}- and {gamma}{eta}-irradiation in different radiation accidents. The main reasons of working disability in the late consequences of ARS period are consequences of local radiation injures (LRI) and joining somatic diseases. Its revealing and treatment considerably improves quality of life of the patients. The heaviest consequence of LRI of a skin at {gamma}{beta}- radiation exposure is the development of late radiation ulcers and radiation fibrosis, which require repeated plastic surgery. LRI at {gamma}{eta}-radiation exposure differ by the greater depth of destruction of a underlying tissues and similar defects require the early amputations. Last 10 years microsurgery methods of plastic surgery allow to save more large segments of extremities and to decrease expression of the late consequences (radiation fibrosis and late radiation ulcers) LRI severe and extremely severe degrees. Medical rehabilitation of radiation cataract (development at doses more than 2.0 Gy) includes its extraction and artificial lens implantation, if acuity of vision is considerably decreased. Changes of peripheral blood, observed at the period of the long consequences, as a rule, different, moderate, transient and not requiring treatment. Only one ARS survivor dead from chronic myeloid leukemia. Thyroid nodes, not requiring operative intervention, are found out in Chernobyl survivors. Within the time course the concurrent somatic disease become the major importance for patients disability growth, which concurrent diseases seem to be unrelated to radiation dose and their structure does not differ from that found in general public of Russia. The rehabilitation of the persons who have transferred ARS as a result of radiating failure, should be directed on restoration of functions critical for ionizing of radiation of bodies and 7. Lightweight High Temperature Beta Gamma Alloy/Process Development for Disk and Blade Applications, Phase I Data.gov (United States) National Aeronautics and Space Administration — The primary material and manufacturing limitations of gamma TiAl alloys include processing difficulties, requiring costly non-conventional processing requirements,... 8. Study of a 4{pi}{beta}-{gamma} coincidence system for absolute radionuclide activity measurement using plastic scintillators; Estudo de um sistema de coincidencias 4{pi}{beta}-{gamma} para a medida absoluta de atividade de radionuclideos empregando cintiladores plasticos Energy Technology Data Exchange (ETDEWEB) Piuvezam Filho, Helio 2007-07-01 The present work was intended to study a coincidence system 4{pi}(PS){beta}-{gamma} for absolute activity measurement using plastic scintillators in 4{pi} geometry. Along with experiments on the coincidence system, simulations were also performed applying the Monte Carlo Method, by means of codes PENELOPE and ESQUEMA. These simulations were performed in order to calculate the extrapolation curve of the coincidence system 4{pi}(PS){beta}-{gamma} and compare it to experimental data. A new geometry was proposed to the coincidence system adding up a second photomultiplier tube to the previous system for improving light collection from the plastic scintillator, as this system presented limitations in the minimum detected energy due to the presence of electronic noise and low gain. The results show that an improvement in the signal-to-noise ratio was obtained, as well as in the minimum detected energy. Moreover, there was an increase in the detection efficiency. With these modifications, it is now possible to calibrate radionuclides which emit low energy electrons or X-rays, increasing the number of radionuclides that can be standardized with this type of system.(author) 9. Do we need an emergency planning for contamination with alpha or beta emitting materials and how should this be? International Nuclear Information System (INIS) Gellermann, Rainer; Kueppers, Christian; Urbach, Michael; Schnadt, Horst; Lange, Florentin 2016-01-01 The emergency planning up to now was geared to the consequences of accidents in nuclear facilities. There were no planning guidelines like the recommendations for emergency planning in the vicinity of nuclear facilities for other radiological incidents. According to article 98 of the new European radiation protection standards the member states have to take care for the preparation of emergency plans fir the case of emergency exposure scenarios. The study discusses several scenarios that might induce alpha or beta contamination, existing approaches for guiding contamination values, intervention benchmarks, protection strategies including continuing public information, selected radionuclides that might be involved, exposure paths, guidance benchmarks for person decontamination, and recommendations for new emergency plans. 10. Evaluation of the RSG-GAS Alpha-Beta Aerosol Contaminant Monitor Performance Under Reactor Operation Condition International Nuclear Information System (INIS) Hartoyo, Unggul; Setiawanto, Anto; Sumarno, Yulius 2000-01-01 Analysis to evaluate the RSG-GAS alpha-beta aerosol contaminant monitor performance was done. The high potential radiation working area such as in RSG-GAS is important to monitored for personal safety. Further it is necessary to assure that the system monitor is reliable enough under normal conditions as well as emergency condition. The method uses in this analysis are monitoring and comparing with the standard source. The standard course indicator and panel in main control room indicate that the result is 1 x 110 exp 9 Ci/m exp 3. Based on data monitor observation, the RSG-GAS alpha-beta aerosol contaminant monitor system under reactor operation condition has a good enough performance 11. Combination of digital autoradiography and alpha track analysis to reveal the distribution of definite alpha- and beta-emitting nuclides in contaminated samples Energy Technology Data Exchange (ETDEWEB) Vlasova, I. [Lomonosov MSU (Russian Federation); Kuzmenkova, N. [Vernadsky GEOKHI RAS (Russian Federation); Shiryaev, A. [Frumkin IPCE RAS (Russian Federation); Pryakhin, E. [Urals Research Center for Radiation Medicine (Russian Federation); Kalmykov, S.; Ivanov, I. [PA Mayak (Russian Federation) 2014-07-01 Digital autoradiography using Imaging Plate is commonly employed for searching 'hot' particles in the contaminated soil, sediment and aerosol probes. However digital radiography images combined with Alpha Track radiography data could provide much more information about micro-distribution of different alpha- and beta- nuclides. The discrimination method to estimate the distribution of radionuclides that are the main contributors to the total radioactivity ({sup 90}Sr/{sup 90}Y, {sup 137}Cs, {sup 241}Am) has been developed on the case of artificial reservoir V-17 (PA 'Mayak'). The bottom sediments and hydrobionts probes collected from V-17 along with the standards of {sup 137}Cs, {sup 90}Sr/{sup 90}Y and {sup 241}Am have been exposed for a short time (15 min) using a stack of 3 Imaging Plates (Cyclone Plus Storage Phosphor System, Perkin Elmer). The attenuation of photostimulated luminescence (PSL) intensity from layer to layer of the Imaging Plates depends on the type and energy of radiation. Integrated approach using PSL attenuation in the samples and standards (digital radiography) along with Alpha Track radiography and gamma-spectroscopy of the preparation was used to estimate the contribution of the main nuclides in specific parts of contaminated samples. The observation of the {sup 90}Sr/{sup 90}Y and {sup 137}Cs activity maxima could help to find the phases which are responsible for preferential sorption of the nuclides. Document available in abstract form only. (authors) 12. Effect of gamma radiation on the survival of fungal and actinomycetal florae contaminating medicinal plants International Nuclear Information System (INIS) Aziz, N.H.; El-Fouly, M.Z.; Moussa, L.A.A.; Abu-Shady, M.R. 1997-01-01 This study evaluates the effect of gamma radiation on the viability of fungi and actinomycetes that contaminate medicinal plants. The relationship between the total lipids of some fungi and actinomycetes and their sensitivity to gamma radiation is also investigated. The data reveal that the viable counts of these florae decrease approximately exponentially with the radiation dose, the effective dose for the elimination of these microorganisms being about 5 kGy for all the medicinal plants under study. Response of pure cultures of fungi and actinomycetes isolated from medicinal plants to increasing absorbed doses of gamma radiation indicate that an increase in radioresistance is in the following order: Streptomyces rimosus, Fusarium solani, Nocardia kuroishii. F. oxysporum, A. fumigatus, A. flavus, A. parasiticus and A. ochraceus. The total lipid contents of molds and actinomycetes have been reported to be increased by increasing the radio-resistance of microorganisms, and hence there is a relationship between the radio-sensitivity of microorganisms and the total lipid mass of flora mycelia. (Author) 13. Effect of gamma radiation on the survival of fungal and actinomycetal florae contaminating medicinal plants Energy Technology Data Exchange (ETDEWEB) Aziz, N.H.; El-Fouly, M.Z.; Moussa, L.A.A. [National Center for Radiation Research and Technology, Cairo (Egypt); Abu-Shady, M.R. [Ain Shams Univ., Cairo (Egypt). Faculty of Science 1997-01-01 This study evaluates the effect of gamma radiation on the viability of fungi and actinomycetes that contaminate medicinal plants. The relationship between the total lipids of some fungi and actinomycetes and their sensitivity to gamma radiation is also investigated. The data reveal that the viable counts of these florae decrease approximately exponentially with the radiation dose, the effective dose for the elimination of these microorganisms being about 5 kGy for all the medicinal plants under study. Response of pure cultures of fungi and actinomycetes isolated from medicinal plants to increasing absorbed doses of gamma radiation indicate that an increase in radioresistance is in the following order: Streptomyces rimosus, Fusarium solani, Nocardia kuroishii. F. oxysporum, A. fumigatus, A. flavus, A. parasiticus and A. ochraceus. The total lipid contents of molds and actinomycetes have been reported to be increased by increasing the radio-resistance of microorganisms, and hence there is a relationship between the radio-sensitivity of microorganisms and the total lipid mass of flora mycelia. (Author). 14. Respiration and phosphorylation in liver and kidney mitochondria of rats exposed to high-energy gamma and beta radiation Energy Technology Data Exchange (ETDEWEB) Mokhoreva, S I; Vetlugina, N S 1973-01-01 The effect of whole-body irradiation with ..gamma.. rays (radiation source /sup 60/Co) at 40 rad and ..beta.. rays (source, a linear accelerator, electron energy 25 MeV) at 43 rad on oxidative phosphorylation in liver and kidney mitochondria was studied in rats. Gamma radiation gradually slowed the esterification of phosphate and respiratory rate during the oxidation of succinate in the liver and kidney mitochondria. The decrease was largest on day 15 after irradiation. However, the P/O ratio did not decrease by more than 10 to 12 percent. Despite the oxidation of glutamate in the mitochondria, respiration, phosphate consumption, and P/O ratio scarcely changed. Irradiation with electrons slowed the rate of oxidation of succinate and glutamate in liver mitochondria within 3 to 7 days. Phosphate consumption decreased at the same time so that the P/O ratio remained unchanged. Beta irradiation had virtually no effect on liver mitochondria. There is a discussion of the mechanism of action of high-energy radiation on the phosphorylation system of the mitochondria. 15. FPDCYS and FPSPEC: computer programs for calculating fission-product beta and gamma multigroup spectra from ENDF/B-IV data International Nuclear Information System (INIS) Stamatelatos, M.G.; England, T.R. 1977-05-01 FPDCYS and FPSPEC are two FORTRAN computer programs used at the Los Alamos Scientific Laboratory (LASL), in conjunction with the CINDER-10 program, for calculating cumulative fission-product beta and/or gamma multigroup spectra in arbitrary energy structures, and for arbitrary neutron irradiation periods and cooling times. FPDCYS processes ENDF/B-IV fission-product decay energy data to generate multigroup beta and gamma spectra from individual ENDF/B-IV fission-product nuclides. FPSPEC further uses these spectra and the corresponding nuclide activities calculated by the CINDER-10 code to produce cumulative beta and gamma spectra in the same energy grids in which FPDCYS generates individual isotope decay spectra. The code system consisting of CINDER-10, FPDCYS, and FPSPEC has been used for comparisons with experimental spectra and continues to be used at LASL for generating spectra in special user-oriented group structures. 3 figures 16. Remediation of soil contaminated with pesticides by treatment with gamma radiation International Nuclear Information System (INIS) Santos, Janilson Silva 2009-01-01 The discharge of empty plastic packaging of pesticides can be an environmental concern mainly by soil contamination. Nowadays, Brazil figures in third place among the leading world pesticide markets. An understanding of the processes that affect the transport and fate of pesticides is crucial to assess their potential for contamination of soil and groundwater, and to develop efficient and cost-effective site management and soil remediation strategies. Due to its impact on soil remediation has made sorption a major topic of research on soil-pesticide interactions. The main objective of this study is the evaluation of the pesticides transferring from contaminated mixture of commercial polymeric packing of high-density polyethylene, HDPE, used in agriculture to soil and their removal by gamma irradiation. Two soil samples of argyles compositions and media composition were exposed to a mixture of commercial polymeric packing contaminated with the pesticides methomyl, dimethoate, carbofuran, methidathion, triazine, thiophos, atrazine, ametryne, endosulfan, chloropyrifos, thriazophos and trifluralin. The pesticides leaching from packaging to soil was homogeneous considering a experimental research. The radiation treatment presented high efficiency on removal pesticides from both soil, but it depends on the physical-chemical characteristics of the contaminated soil. The higher efficiency was obtained in soils with higher organic material and humidity. The higher efficiency was obtained for the medium texture soil, with 20 kGy all present pesticides were removed in all layers. In the case of argyles texture soil, it was necessary a 30 kGy to remove the totality of present pesticides. (author) 17. Blood biochemical disorders in gamma irradiated rats maintained on pesticide contaminated food International Nuclear Information System (INIS) Abdel-Hamid, F. M. 1997-01-01 The present work deals with the effect of 6.5 Gy whole body gamma irradiation on male albino rats kept ether under normal environmental condition or subjected to either short or long term of internal contamination with the environmental chemical pollutant kelthane widely applied as organo chlorine miticide. This has need introduced either through daily oral administration at the doses 50 and 100 mg/kg b.w. over 3 successive days, or through daily ingestion at the dose 200 mg/kg b.w. over feeding time periods of 3, 6, and 12 weeks. The results obtained demonstrated fluctuations in certain serum metabolites and minerals encountering increased levels serum glucose total lipids, cholesterol, uric acid, creatinine, and inorganic phosphorus. on the other hand, the serum levels of bilirubin, and total calcium tended to decrease. Most of these changes where significantly aggravated when radiation exposure has been undertaken following a prolonged internal contamination with the miticide. This potential risk should be carefully considered when addressing farmers from several areas exposed to pesticide contamination risks, to radiotherapy clinics or to occupational radiation practices 18. Evaluation of transformation growth factor beta1, interleukin-10, and interferon-gamma in male symptomatic and asymptomatic dogs naturally infected by Leishmania (Leishmania) chagasi. Science.gov (United States) Corrêa, Ana Paula Ferreira Lopes; Dossi, Ana Cláudia Silva; de Oliveira Vasconcelos, Rosemeri; Munari, Danísio Prado; de Lima, Valéria Marçal Felix 2007-02-28 The aims of this study were to evaluate the immunomodulatory role of TGF-beta1, IL-10, and INF-gamma in spleen and liver extracts and supernatant cultures of white spleen cells from male symptomatic and asymptomatic dogs, naturally infected by Leishmania (Leishmania) chagasi. Thirty dogs from Araçatuba, São Paulo, Brazil, an endemic leishmaniosis area, were selected by positive ELISA serological reaction for Leishmania sp. and divided into two groups: asymptomatic (n=15) and symptomatic (n=15) consisting of animals with at least three characteristic signs (fever, dermatitis, lymphoadenopathy, onychogryphosis, weight loss, cachexia, locomotion problems, conjunctivitis, epistaxis, hepatosplenomegaly, edema, and apathy). After euthanasia, spleen and liver fragments were collected for ex vivo quantification of TGF-beta1, IL-10, and INF-gamma. Naturally active in vitro produced TGF-beta1 was also evaluated in spleen cell culture supernatant. Spleen and liver extract of asymptomatic dogs had higher mean TGF-beta1 levels than symptomatic dogs. High concentrations of IL-10 were found in spleen, and mainly in liver extract of both groups. Higher INF-gamma concentrations were found in spleen extracts of symptomatic dogs, and in liver extracts of asymptomatic dogs. Extract of this cytokine was lower in spleen extract. Although INF-gamma is being produced in canine infection, mean levels of TGF-beta1 and IL-10 from spleen and liver extracts were quantitatively much higher; suggesting that immune response in both asymptomatic and symptomatic dogs was predominantly type Th2. 19. A straightforward and efficient method for the synthesis of diversely substituted {beta}-aminoketones and {gamma}-aminoalcohols from 3-(N,N-dimethylamino)propiophenones as starting materials Energy Technology Data Exchange (ETDEWEB) Abonia, Rodrigo; Arteaga, Danny; Castillo, Juan; Insuasty, Braulio; Quiroga, Jairo; Ortiz, Alejandro, E-mail: rodrigo.abonia@correounivalle.edu.co [Universidad del Valle, Cali (Colombia). Department of Chemistry. Research Group of Heterocyclic Compounds 2013-09-15 Libraries of novel {beta}-aminoketones and {gamma}-aminoalcohols showing a wide structural diversity were easily obtained from a simple approach, using 3-(N,N-dimethylamino)propiophenone derivatives as key starting material. The procedure involved initially an N-alkylation of secondary benzylamines with propiophenone salts yielding the desired {beta}-aminoketones. Chemical or catalytic reduction of their carbonyl groups provided the final {gamma}-aminoalcohols in good yields. This protocol proved to be convenient as an alternative route for the synthesis of the local anesthetic Falicain Registered-Sign and for the topic antifungal drug Naftifine Registered-Sign . (author) 20. Beta and gamma decay heat measurements between 0.1s--50,000s for neutron fission of 235U, 238U and 239Pu International Nuclear Information System (INIS) Schier, W.A.; Couchell, G.P. 1993-01-01 A helium-jet/tape-transport system is employed in the study of beta-particle and gamma-ray energy spectra of aggregate fission products as a function of time after fission. During the initial nine months of this project we have investigated the following areas: Design, assembly and characterization of a beta-particle spectrometer; Measurement of 235 U(n th ff) beta spectra for delay times 0.2 s to 12,000 s; Assembly and characterization of a 5 x 5 Nal(Tl) gamma-ray spectrometer; Measurement of 235 U(n th ff) gamma-ray spectra for delay times 0.2s to 1 5,500s; Assembly and characterization of HPGe gamma-ray spectrometer with a Nal(Tl) Compton-and-background-suppression annulus; Measurement of 235 U(n th ,ff) high-resolution gamma-ray spectra for delay times 0.6 s to over 100,000 s; Comparison of individual gamma-line intensities with ENDF/B-VI; Adaptation to our computer of unfolding program FERDO for beta and gamma aggregate fission-product energy spectra and development of a spectrum-stripping program for analysis of HPGe gamma-ray spectra; Study of the helium-jet fission-fragment elemental transfer efficiency. This work has resulted in the publication of twelve BAPS abstracts of presentations at scientific meetings. There are currently four Ph.D. and two M.S. candidates working on dissertations associated with the project 1. Control of ergosterol producer fungi contaminating cereal grains by certain environmental conditions and gamma rays International Nuclear Information System (INIS) Shahin, A.A.M. 2007-01-01 Existence of ergosterol in grains usually gives an indication that these grains are contaminated by ergosterol producing fungi. So, ergosterol concentration could be a suitable marker for estimation of fungal contamination range in cereal grains. Thirty eight fungal isolates were isolated from maize, sorghum and barley grains. Alternaria, Cladosporium and Aspergillus were the most common fungal genera among these isolates and they were tested for ergosterol production. The highest ergosterol producing fungi were identified as Alternaria alternaria, Cladosporium herbarum and Aspergillus niger var.niger. The present results indicate that the most suitable conditions for producing ergosterol by these strains in maize grains were found to be at 25 degree C for 30 days. Exposing the artificially contaminated maize grains by the above three strains (10 7 CFU/ml) to increasing dose levels of gamma rays up to 10 kGy and storing for 30 days, gradually decreased the production of ergosterol to 7.9, 6.2 and 1.5 mg/g dry weight of grains by A. alternata and C.herbarum and A. niger var. niger, respectively. D 10 values of the tested three isolates in maize grains were found to be 2, 1.61, and 1.2 kGy, respectively. The results showed that cold storage (10 degree C) clearly decreased the activity of the tested fungi for producing ergosterol during the storage periods, and a dose level of 15 kGy was quite enough to free the grains from A. alternata, Cladosporium herbarum and A. niger var. niger, regardless the contamination level of grains with these ergosterol producer fungus 2. Application of Monte Carlo method in study of the padronization for radionuclides with complex disintegration scheme in 4{pi}{beta}-{gamma} coincidence System; Aplicacao do metodo de Monte Carlo no estudo da padronizacao de radionuclideos com esquema de desintegracao complexos em sistema de coincidencias 4{pi}{beta}-{gamma} Energy Technology Data Exchange (ETDEWEB) Takeda, Mauro Noriaki 2006-07-01 The present work described a new methodology for modelling the behaviour of the activity in a 4{pi}{beta}-{gamma} coincidence system. The detection efficiency for electrons in the proportional counter and gamma radiation in the NaI(Tl) detector was calculated using the Monte Carlo program MCNP4C. Another Monte Carlo code was developed which follows the path in the disintegration scheme from the initial state of the precursor radionuclide, until the ground state of the daughter nucleus. Every step of the disintegration scheme is sorted by random numbers taking into account the probabilities of all {beta}{sup -} branches, electronic capture branches, transitions probabilities and internal conversion coefficients. Once the final state was reached beta, electronic capture events and gamma transitions are accounted for the three spectra: beta, gamma and coincidence variation in the beta efficiency was performed simulating energy cut off or use of absorbers (Collodion). The selected radionuclides for simulation were: {sup 134}Cs, {sup 72}Ga which disintegrate by {beta}{sup -} transition, {sup 133}Ba which disintegrates by electronic capture and {sup 35}S which is a beta pure emitter. For the latter, the Efficiency Tracing technique was simulated. The extrapolation curves obtained by Monte Carlo were filled by the Least Square Method with the experimental points and the results were compared to the Linear Extrapolation method. (author) 3. Copper(II) 12-metallacrown-4 complexes of alpha-, beta- and gamma-aminohydroxamic acids: a comparative thermodynamic study in aqueous solution. Science.gov (United States) Tegoni, Matteo; Remelli, Maurizio; Bacco, Dimitri; Marchiò, Luciano; Dallavalle, Francesco 2008-05-28 A complete thermodynamic study of the protonation and Cu(II) complex formation equilibria of a series of alpha- and beta-aminohydroxamic acids in aqueous solution was performed. The thermodynamic parameters obtained for the protonation of glycine-, (S)-alpha-alanine-, (R,S)-valine-, (S)-leucine-, beta-alanine- and (R)-aspartic-beta-hydroxamic acids were compared with those previously reported for gamma-amino- and (S)-glutamic-gamma-hydroxamic acids. The enthalpy/entropy parameters calculated for the protonation microequilibria of these three types of ligands are in very good agreement with the literature values for simple amines and hydroxamic acids. The pentanuclear complexes [Cu5L4H(-4)]2+ contain the ligands acting as (NH2,N-)-(O,O-) bridging bis-chelating and correspond to 12-metallacrown-4 (12-MC-4) which are formed by self-assembly between pH 4 and 6 with alpha-aminohydroxamates (HL), while those with beta- and gamma-derivatives exist in a wider pH range (4-11). The stability order of these metallomacrocycles is beta- > alpha- > gamma-aminohydroxamates. The formation of 12-MC-4 with alpha-aminohydroxamates is entropy-driven, and that with beta-derivatives is enthalpy-driven, while with gamma-GABAhydroxamate both effects occur. These results are interpreted on the basis of specific enthalpies or entropy contributions related to chelate ring dimensions, charge neutralization and solvation-desolvation effects. The enthalpy/entropy parameters of 12-MC-4 with alpha-aminohydroxamic acids considered are also dependent on the optical purity of the ligands. Actually, that with (R,S)-valinehydroxamic acid presents an higher entropy and a lower enthalpy value than those of enantiopure ligands, although the corresponding stabilities are almost equivalent. Moreover, DFT calculations are in agreement with a more exothermic enthalpy found for metallacrowns with enantiomerically pure ligands. 4. Beta-delayed gamma and neutron emission near the double shell closure at 78Ni International Nuclear Information System (INIS) Rykaczewski, Krzysztof Piotr; Mazzocchi, C.; Grzywacz, R.; Batchelder, J. C.; Bingham, C.R.; Fong, D.; Hamilton, J.H.; Hwang, J.K.; Karny, M.; Krolas, W.; Liddick, S. N.; Morton, A. C.; Mantica, P. F.; Mueller, W. F.; Steiner, M.; Stolz, A.; Winger, J.A. 2005-01-01 An experiment was performed at the National Superconducting Cyclotron Laboratory at Michigan State University to investigate β decay of very neutron-rich cobalt isotopes. Beta-delayed neutron emission from 71-74 Co has been observed for the first time. Preliminary results are reported 5. Standardization of electron-capture and complex beta-gamma radionuclides by the efficiency extrapolation method International Nuclear Information System (INIS) Grigorescu, L. 1976-07-01 The efficiency extrapolation method was improved by establishing ''linearity conditions'' for the discrimination on the gamma channel of the coincidence equipment. These conditions were proved to eliminate the systematic error of the method. A control procedure for the fulfilment of linearity conditions and estimation of residual systematic error was given. For law-energy gamma transitions an ''equivalent scheme principle'' was established, which allow for a correct application of the method. Solutions of Cs-134, Co-57, Ba-133 and Zn-65 were standardized with an ''effective standard deviation'' of 0.3-0.7 per cent. For Zn-65 ''special linearity conditions'' were applied. (author) 6. Contribution to the study of the sintering mechanisms of uranium powders in the {alpha}, {beta}, and {gamma} phases; Contribution a l'etude des mecanismes de frittage de poudre d'uranium en phases {alpha}, {beta}, et {gamma} Energy Technology Data Exchange (ETDEWEB) Pinteau, B [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires 1964-06-01 This study of the sintering mechanisms of uranium powders prepared by calci-thermy has been effected using continuous dilatometric measurements of the shrinkage of samples previously compressed at room temperature in purified argon gas. The tests carried out in the {alpha}, {beta} and {gamma} phases have led to the observation that the first step of the sintering appears to be governed by a volume self-diffusion mechanism; the activation heat values found for the sintering mechanisms are close to those deduced during studies of volume self-diffusion using the direct radio-tracer method. Furthermore it has been possible to show that in the {gamma} domain a second sintering mechanism occurs involving much longer sintering times; the heats of activation are much lower and this appears to indicate that there occurs a mechanism involving pore elimination by grain boundary diffusion of the vacancies. Furthermore, the dilatometric tests have shown the simultaneous influence of two important parameters in this work: grain boundaries and the diffusion coefficients. In the second part of the report are given results concerning the examination of sintered samples by various methods with a view to elucidating their structure and some of their physical properties. In this way it has been possible, by carrying out metallographic examinations after etching by ionic bombardment, to determine the changes in the porosity of the three phases {alpha}, {beta} and {gamma}, as well as the structure and the nature of the inclusions in each sample. Density and porosity measurements have also been carried out. The variations in these two sets of results make it possible to confirm the preceding dilatometric end micro-graphic examinations. Finally a detailed dilatometric study of the samples sintered in the {gamma} phase has shown the effect of oxide layers, associated with the existence of porosity, on the amplitudes and temperatures of the allotropic transformations, these latter being 7. Peripheral blood IFN-gamma-secreting V alpha 24(+)V beta 11(+) NKT cell numbers are decreased in cancer patients independent of tumor type or tumor load NARCIS (Netherlands) Molling, JW; Kolgen, W; van der Vliet, HJJ; Boomsma, MF; Kruizenga, H; Smorenburg, CH; Molenkamp, BG; Langendijk, JA; Leemans, CR; von Blomberg, BME; Scheper, RJ; van den Eertwegh, AJM 2005-01-01 Natural killer T (NKT) cells are CDld-restricted lvmphoid cells and are characterized by an invariant T-cell receptor, which in humans consists of a V alpha 24 chain paired with a V beta 11 chain. These cells are known for their rapid production of large amounts of cytokines (e.g., IFN-gamma and 8. Serotonin Transporter (5-HTT) and gamma-Aminobutyric Acid Receptor Subunit beta3 (GABRB3) Gene Polymorphisms are not Associated with Autism in the IMGSA Families DEFF Research Database (Denmark) Maestrini, E.; Lai, C.; Marlow, A. 1999-01-01 Previous studies have suggested that the serotonin transporter (5-HTT) gene and the gamma-aminobutyric acid receptor subunit beta3 (GABRB3) gene, or other genes in the 15q11-q13 region, are possibly involved in susceptibility to autism. To test this hypothesis we performed an association study on... 9. Effects of the gamma and ultrasound radiation in orange juice contaminated by Alicyclobacillus acidoterrestris International Nuclear Information System (INIS) Pires, Cristiane Cassiolato 2006-01-01 The orange juice has attributes could make that hard or even block the growth. of microorganisms, even so already have been isolated filamentous fungi, yeast, as well lactic and heat resistant bacteria. Alicyclobacillus acidoterrestris is a heat resistant bacteria that has done damage in the orange juice concentrated and frozen business. This bacterium is able the grown in temperatures below 35 deg C constituting a risk to orange juices that have been contaminated. Even those that already pass trough thermal treatment may deteriorated, if they are storage in place without refrigeration. As the traditional methods of decontamination and conservation have not been effective in unfeasible this bacterium, others methods of sterilization are need, among them are gamma and ultrasound radiation. The gamma radiation is able to sterilize foods and reduce the microbiology density, allowing in this way to enhance the period of storage. The ultrasound application has been used currently with the aim to microbiology control, been this technique effective in the microbial cell destruction. The Brazil, are the major producer and exporter of concentrated frozen orange juice, due to it, the present work was carried out to two experiments with the aim to determinate the resistance of the bacterium Alicyclobacillus acidoterrestris to gamma and ultrasound irradiation, in the orange juice, priory contaminated. The orange juice samples was diluted to 11,5 deg Brix and the bacteria suspensions was added, passed by process of radiation gamma with dose of 0, 2, 4, 6 and 8 kGy and ultrasonic with the frequency of 25, 35 and 42 kHz and with the time of exposition of 0, 1, 5, 10 and 20 minutes. After the treatment, the samples were stored in room temperature (25 +- 2 deg C) and of refrigeration (4 +- 1 deg C). For the microbial analyses, the samples were diluted in to decimal scale, plated by 'pour plate' technique. The Petri plates were storage in warn temperature (46 +- 2 deg C) by 48 hours 10. Development of high sensitivity gamma and beta sensors for in situ diffusion tests in the mudstone in France International Nuclear Information System (INIS) Lin, Zhenhua 2017-01-01 The precise monitoring of radiotracers, for example used for medical imaging, for the storage of ultimate waste, or for certain industrial applications can be a very complex subject. The development of low-noise sensors with long-term stability and high geometric flexibility were engaged by the AXINT company. (Hautefeuille, et al., 2006). My PhD thesis was focused on experiments in the diffusion of radiotracers, typically to monitor the possible leakage of radioactive products from the geological repositories. We focuses on the study of the "2"2Na and "3"6Cl ion diffusion, which is one of the highest cation and anions diffusion rate in geological medium, as well as actinides, which represent the majority of the radioactive elements of Stored nuclear waste. This thesis is in continuity with the research carried out by ANDRA (National Agency for Radioactive Waste), under contract with the laboratory ILM (Institute Light Matter), of which AXINT is the main subcontractor. The present project describes the research work that foreseen the radiation impact on the environment for the coming years during the deep disposal of nuclear waste. Our work focus on the investigation and quantification of the radionuclide diffusion through the geological clay barriers. A new in situ experiment was considered by Andra for the study of the radionuclide migration. Compared to previous experiments, this new in situ diffusion test required longer distance (hundreds of mm), longer time-scale (over 10 years), and real time in situ monitoring of radionuclides migration. To fulfill these conditions, the work was organized as following: 1: Conception and dimensional design of the Diffusion of Radio Nuclide (DRN) experiments in solving emission of beta and gamma radiations 2: Development of corresponding beta and gamma monitoring systems by means of sensors located in peripheral boreholes. (author) [fr 11. Development of a low cost, GPS-based upgrade to a standard handheld gamma detector for mapping environmental radioactive contamination. Science.gov (United States) Paridaens, J 2006-02-01 A low cost extension to a standard handheld radiation monitor was developed, allowing one to perform outdoor georeferenced gamma measurements. It consists of a commercial wireless Bluetooth GPS receiver, a commercial RS-232 to Bluetooth converter combined with a standard Bluetooth enabled pocket personal computer (PPC). The system is intended for use in difficult to access areas, typically for foot campaigns. As the operator walks, a straightforward homemade visual basic program alternately reads GPS position and gamma dose rate into the PPC, creating a data log. This allows a single operator on foot to map between 50 and 200 ha of environmental radiation per day in very rugged areas, depending on the accessibility of the terrain and the detail required. On a test field with known contamination, a spatial precision of about 5-10 m was obtainable. The device was also used to reveal complex contamination patterns in the flooding zones of a radioactively contaminated small river. 12. Decay profiles of {beta} and {gamma} for a radionuclide inventory in equilibrium cycle of a BWR type reactor; Perfiles de decaimiento de radiacion {beta} y {gamma} para un inventario de radionuclidos en ciclo de equilibrio de un reactor tipo BWR Energy Technology Data Exchange (ETDEWEB) Salaices, M.; Sandoval, S.; Ovando, R. [Instituto de Investigaciones Electricas. Gerencia de Energia Nuclear, Av. Reforma 113 Col. Palmira. 62490 Cuernavaca, Morelos (Mexico)]. e-mail: sal@iie.org.mx 2007-07-01 Presently work the {beta} and {gamma} radiation decay profiles for a radionuclides inventory in equilibrium cycle of a BWR type reactor is presented. The profiles are presented in terms of decay in the activity of the total inventory as well as of the chemical groups that conform the inventory. In the obtaining of the radionuclides inventory in equilibrium cycle the ORIGEN2 code, version 1 was used, which simulates fuel burnup cycles and it calculates the evolution of the isotopic composition as a result of the burnt one, irradiation and decay of the nuclear fuel. It can be observed starting from the results that the decrease in the activity for the initial inventory and the different chemical groups that conform it is approximately proportional to the base 10 logarithm of the time for the first 24 hours of having concluded the burnt one. It can also be observed that the chemical groups that contribute in more proportion to the total activity of the inventory are the lanthanides-actinides and the transition metals, with 39% and 28%, respectively. The groups of alkaline earth metals, halogens, metalloids, noble gases and alkaline metals, contribute with percentages that go from the 8 to 5%. The groups that less they contribute to the total activity of the inventory they are the non metals and semi-metals with smaller proportions that 1%. The chemical groups that more contribute to the energy of {beta} and {gamma} radiation its are the transition metals and the lanthanides-actinides with a change in the order of importance at the end of the 24 hours period. The case of the halogens is of relevance for the case of the {gamma} radiation energy due that occupying the very near third site to the dimensions of the two previous groups. Additionally, the decay in the activity for the total inventory and the groups that conform it can be simulated by means of order 6 polynomials or smaller than describe its behavior appropriately. The results presented in this work, coupled 13. A NIM (Nuclear Instrumentation Module) system conjugated with optional input for pHEMT amplifier for beta and gamma spectroscopy International Nuclear Information System (INIS) Konrad, Barbara; Lüdke, Everton 2014-01-01 This work presents a high speed NIM module (Nuclear Instrumentation Module) to detect radiation, gamma and muons, as part of a system for natural radiation monitoring and of extraterrestrial origin. The subsystem developed consists of a preamplifier and an integrated SCA (Single Channel Analyzer), including power supplies of ± 12 and ± 24V with derivations of +3.6 and ± 5V. The single channel analyzer board, consisting of discrete logic components, operating in window modes, normal and integral. The pulse shaping block is made up of two voltage comparators working at 120 MHz with a response time > 60 ns and a logic anticoincidence system. The preamplifier promotes a noise reduction and introduces the impedance matching between the output of anode / diode photomultiplier tubes (PMTs) and subsequent equipment, providing an input impedance of 1MΩ and output impedance of 40 to 140Ω. The shaper amplifier is non-inverting and has variable input capacitance of 1000 pF. The upper and lower thresholds of the SCA are adjustable from 0 to ± 10V, and the equipment is compatible with various types of detectors, like PMTs coupled to sodium iodide crystals. For use with liquid scintillators and photodiodes with crystals (CsI: Tl) is proposed to include a preamplifier circuit pHEMT (pseudomorphic High Electron Mobility Transistor) integrated. Yet, the system presents the possibility of applications for various purposes of gamma spectroscopy and automatic detection of events producing of beta particles 14. Comparative Analysis Electroencephalographic of Alpha, Beta and Gamma Bands of a Healthy Individual and One with Hemiparesis Science.gov (United States) Machado, Dionis de Castro Dutra; Lima, Glenda Crispim; Souza dos Santos, Rodrigo; Ramos, Amanda Júlia Bezerra; Menezes de Sousa, Cáio César; Moreira dos Santos, Rayele Pricila; Coelho, Karyna Kelly Oliveira; Cagy, Mauricio; Orsini, Marco; Bastos, Victor Hugo 2014-01-01 [Purpose] The study analyzed the electroencephalographic (EEG) data of the central cortical areas, during execution of the motor gestures of feeding, activation of the system of mirror neurons, and imagery between a right hemiparetic volunteer (RHV) and a healthy volunteer (HV). [Subjects and Methods] The volunteers’ EEG data were recorded with their eyes open for 4 minutes while they performed five experimental tasks. [Results] The alpha band, absolute power value of HV was lower than that of RHV. In the beta band, during the practice condition, there was an increase in the magnitude of the absolute power value of HV at T3, possibly because T3 is representative of secondary motor areas that work with cortical neurons related to planning and organizing sequence of movements performed by the hands. The gamma band is related to the state of preparation for movement and memory. The results of this study indicate that there was increased activation of the gamma frequency band of HV. [Conclusion] The findings of this study have revealed the changes in pattern characteristics of each band which may be associated with the brain injury of the hemiparetic patient. PMID:25013270 15. Hydrogen bonds between the alpha and beta subunits of the F1-ATPase allow communication between the catalytic site and the interface of the beta catch loop and the gamma subunit. Science.gov (United States) Boltz, Kathryn W; Frasch, Wayne D 2006-09-19 F(1)-ATPase mutations in Escherichia coli that changed the strength of hydrogen bonds between the alpha and beta subunits in a location that links the catalytic site to the interface between the beta catch loop and the gamma subunit were examined. Loss of the ability to form the hydrogen bonds involving alphaS337, betaD301, and alphaD335 lowered the k(cat) of ATPase and decreased its susceptibility to Mg(2+)-ADP-AlF(n) inhibition, while mutations that maintain or strengthen these bonds increased the susceptibility to Mg(2+)-ADP-AlF(n) inhibition and lowered the k(cat) of ATPase. These data suggest that hydrogen bonds connecting alphaS337 to betaD301 and betaR323 and connecting alphaD335 to alphaS337 are important to transition state stabilization and catalytic function that may result from the proper alignment of catalytic site residues betaR182 and alphaR376 through the VISIT sequence (alpha344-348). Mutations betaD301E, betaR323K, and alphaR282Q changed the rate-limiting step of the reaction as determined by an isokinetic plot. Hydrophobic mutations of betaR323 decreased the susceptibility to Mg(2+)-ADP-AlF(n)() inhibition and lowered the number of interactions required in the rate-limiting step yet did not affect the k(cat) of ATPase, suggesting that betaR323 is important to transition state formation. The decreased rate of ATP synthase-dependent growth and decreased level of lactate-dependent quenching observed with alphaD335, betaD301, and alphaE283 mutations suggest that these residues may be important to the formation of an alternative set of hydrogen bonds at the interface of the alpha and beta subunits that permits the release of intersubunit bonds upon the binding of ATP, allowing gamma rotation in the escapement mechanism. 16. Functional modulation of cerebral gamma-aminobutyric acidA receptor/benzodiazepine receptor/chloride ion channel complex with ethyl beta-carboline-3-carboxylate: Presence of independent binding site for ethyl beta-carboline-3-carboxylate Energy Technology Data Exchange (ETDEWEB) Taguchi, J.; Kuriyama, K. (Kyoto Prefectural Univ. of Medicine (Japan)) 1990-05-01 Effect of ethyl beta-carboline-3-carboxylate (beta-CCE) on the function of gamma-aminobutyric acid (GABA)A receptor/benzodiazepine receptor/chloride ion channel complex was studied. Beta-CCE noncompetitively and competitively inhibited (3H)flunitrazepam binding to benzodiazepine receptor, but not (3H)muscimol binding to GABAA receptor as well as t-(3H)butylbicycloorthobenzoate (( 3H) TBOB) binding to chloride ion channel, in particulate fraction of the mouse brain. Ro15-1788 also inhibited competitively (3H) flunitrazepam binding. On the other hand, the binding of beta-(3H)CCE was inhibited noncompetitively and competitively by clonazepam and competitively by Ro15-1788. In agreement with these results, benzodiazepines-stimulated (3H)muscimol binding was antagonized by beta-CCE and Ro15-1788. Gel column chromatography for the solubilized fraction from cerebral particulate fraction by 0.2% sodium deoxycholate (DOC-Na) in the presence of 1 M KCl indicated that beta-(3H)CCE binding site was eluted in the same fraction (molecular weight, 250,000) as the binding sites for (3H)flunitrazepam, (3H)muscimol and (3H)TBOB. GABA-stimulated 36Cl- influx into membrane vesicles prepared from the bovine cerebral cortex was stimulated and attenuated by flunitrazepam and beta-CCE, respectively. These effects of flunitrazepam and beta-CCE on the GABA-stimulated 36Cl- influx were antagonized by Ro15-1788. The present results suggest that the binding site for beta-CCE, which resides on GABAA receptor/benzodiazepine receptor/chloride ion channel complex, may be different from that for benzodiazepine. Possible roles of beta-CCE binding site in the allosteric inhibitions on benzodiazepine binding site as well as on the functional coupling between chloride ion channel and GABAA receptor are also suggested. 17. Computer aided collimation gamma (Cacao): a new approach in measuring and visualizing the distribution of X and gamma ray emitters in contaminate wounds International Nuclear Information System (INIS) Douiri, A.; Jeanguillaume, C.; Franck, D.; Carlan, L. de; Quartuccio, M.; Begot, S. 2003-01-01 The treatment of contaminated wounds can be greatly improved by visualizing the distribution of the radioactivity that is present. The low sensitivity of the conventional Anger camera means that it can only be used where there is a high level of activity. Moreover, these gamma cameras cannot make full use of the recent progress made in high spatial resolution semi-conductor detectors. In order to increase sensitivity while at the same time maintaining a sufficient resolution of the reconstructed image, the principle of the Computer aided collimation gamma camera (CACAO in French) was proposed as a possible means of using gamma cameras in intern dosimetry. This principle is based on the combined use of collimators with holes that are wider- than the intrinsic resolution of the detector, circular and linear scanning movements, a detector sensitive to the source depth and a specific reconstruction algorithm. This article presents the recent developments of the CACAO system and illustrates by a theoretical and experimental study, its performances compared with the classic tomography system. We start with a general overview of the CACAO system and its reconstruction algorithm. First of all, the superiority of the CACAO system is demonstrated by a simulation ,study. Then, an experimental bench was developed using an implanted silicon pixel detector specifically designed to allow the visualization of a subject contaminated with low energy X and gamma emitters. The study presented here shows images obtained from a phantom composed of three sources of Americium 341 Am. Although the comparison between the conventional and CACAO approaches were not carried out with optimal parameters, especially for CACAO, the initial results show that CACAO has an improved sensitivity and a superior resolution. Finally, the transposition of this system to the practical study of contaminated wounds is discussed. (authors) 18. Fate of sulfamethoxazole, 4-nonylphenol, and 17beta-estradiol in groundwater contaminated by wastewater treatment plant effluent. Science.gov (United States) Barber, Larry B; Keefe, Steffanie H; Leblanc, Denis R; Bradley, Paul M; Chapelle, Francis H; Meyer, Michael T; Loftin, Keith A; Kolpin, Dana W; Rubio, Fernando 2009-07-01 Organic wastewater contaminants (OWCs) were measured in samples collected from monitoring wells located along a 4.5-km transect of a plume of groundwater contaminated by 60 years of continuous rapid infiltration disposal of wastewater treatment plant effluent. Fifteen percent of the 212 OWCs analyzed were detected, including the antibiotic sulfamethoxazole (SX), the nonionic surfactant degradation product 4-nonylphenol (NP), the solvent tetrachloroethene (PCE), and the disinfectant 1,4-dichlorobenzene (DCB). Comparison of the 2005 sampling results to data collected from the same wells in 1985 indicates that PCE and DCB are transported more rapidly in the aquiferthan NP, consistent with predictions based on compound hydrophobicity. Natural gradient in situ tracer experiments were conducted to evaluate the subsurface behavior of SX, NP, and the female sex hormone 17beta-estradiol (E2) in two oxic zones in the aquifer: (1) a downgradient transition zone at the interface between the contamination plume and the overlying uncontaminated groundwater and (2) a contaminated zone located beneath the infiltration beds, which have not been loaded for 10 years. In both zones, breakthrough curves for the conservative tracer bromide (Br-) and SX were nearly coincident, whereas NP and E2 were retarded relative to Br- and showed mass loss. Retardation was greater in the contaminated zone than in the transition zone. Attenuation of NP and E2 in the aquifer was attributed to biotransformation, and oxic laboratory microcosm experiments using sediments from the transition and contaminated zones show that uniform-ring-labeled 14C 4-normal-NP was biodegraded more rapidly 130-60% recovered as 14CO2 in 13 days) than 4-14C E2 (20-90% recovered as 14CO2 in 54 days). There was little difference in mineralization potential between sites. 19. Initial contamination and decontamination of some pathogenic bacteria on beef bowel by gamma irradiation International Nuclear Information System (INIS) Harsojo; Irawati Z 2011-01-01 An experiment has been conducted to study the initial bacterial contamination and decontamination of pathogenic bacteria on beef bowel such as beef liver, tripe and lung by gamma irradiation. The measured parameter were the amount of total aerobe bacteria, total coliforms, Escherichia coli, Staphylococcus spp. and identification of Salmonella. Another experiment has been conducted to study the effect of irradiation on some pathogenic bacteria which was inoculated on beef bowel. The bacteria included Salmonella typhimurium, E. coli 0157, E. coli polyvalent and Vibrio cholera were inoculated on beef bowel, respectively. Irradiation was done with dose of 0; 0.1; 0.2; 0.3 and 0.4 kGy. The irradiation was done at a Multipurpose Panoramic Batch Irradiator (IRPASENA) with a dose rate of 1.149 kGy/h. The results showed no Salmonella was detected in all samples observed. On the other hand, E. coli was found in all samples. The initial contamination of aerobe bacteria were varied from 8.85 x 10"5 to 1.08 x 10"8 cfu/g while coliform were varied from 2.70 x 10"6 to 3.23 x 10"7 cfu/g. The total E. coli were varied from 8.55 x 10"5 to 2.60 x 10"7 cfu/g, while the total Staphylococcus spp were varied from 1.6 x 10"5 to 4.10 x 10"7 cfu/g. E. coli 0157 was the most radiosensitive bacteria in beef bowel among others, likewise V. cholera was the most radioresistant bacteria among the others. (author) 20. Relations between morphology and micromechanical properties of alpha, beta and gamma phases of iPP Czech Academy of Sciences Publication Activity Database Šlouf, Miroslav; Pavlova, Ewa; Krejčíková, Sabina; Ostafinska, Aleksandra; Zhigunov, Alexander; Krzyžánek, Vladislav; Sowinski, P.; Piorkowska, E. 2018-01-01 Roč. 67, May (2018), s. 522-532 ISSN 0142-9418 R&D Projects: GA MZd(CZ) NV15-31269A; GA TA ČR(CZ) TE01020118; GA MŠk(CZ) LO1507 Grant - others:AV ČR(CZ) PAN-17-18 Program:Bilaterální spolupráce Institutional support: RVO:61389013 ; RVO:68081731 Keywords : polypropylene * gamma-phase * micromechanical properties Subject RIV: CD - Macromolecular Chemistry; JA - Electronics ; Optoelectronics, Electrical Engineering (UPT-D) OBOR OECD: Polymer science; Electrical and electronic engineering (UPT-D) Impact factor: 2.464, year: 2016 1. Comparison of new and existing algorithms for the analysis of 2D radioxenon beta gamma spectra International Nuclear Information System (INIS) Deshmukh, Nikhil; Prinke, Amanda; Miller, Brian; McIntyre, Justin 2017-01-01 The aim of this study is to compare radioxenon beta–gamma analysis algorithms using simulated spectra with experimentally measured background, where the ground truth of the signal is known. We believe that this is among the largest efforts to date in terms of the number of synthetic spectra generated and number of algorithms compared using identical spectra. We generate an estimate for the minimum detectable counts for each isotope using each algorithm. The paper also points out a conceptual model to put the various algorithms into a continuum. Finally, our results show that existing algorithms can be improved and some newer algorithms can be better than the ones currently used. 2. Reference sources for the calibration of surface contamination monitors - Beta-emitters (maximum beta energy greater than MeV) and alpha-emitters (International Standard Publication ISO 8769:1988) International Nuclear Information System (INIS) Stefanik, J. 2001-01-01 This International Standard specifies the characteristics of reference sources of radioactive surface contamination, traceable to national measurement standards, for the calibration of surface contamination monitors. This International Standard relates to alpha-emitters and to beta-emitters of maximum beta energy greater than 0,15 MeV. It does not describe the procedures involved in the use of these reference sources for the calibration of surface contamination monitors. Such procedures are specified in IEC Publication 325 and other documents. This International Standard specifies reference radiations for the calibration of surface contamination monitors which take the form of adequately characterized large area sources specified, without exception, in terms of activity and surface emission rate, the evaluation of these quantities being traceable to national standards 3. Differential effects of whole-body {gamma}-irradiation on antinociception induced by morphine and {beta}-endorphin administered intracerebroventricularly in the mouse Energy Technology Data Exchange (ETDEWEB) Kim, J.K. [Korea Atomic Energy Research Inst., Taejon (Korea, Republic of); Chung, K.M.; Park, T.W. 2000-05-01 Two separate lines of evidence suggested the present study. First, intracerebroventricularly (i.c.v.) administered morphine (a {mu}-opioid receptor agonist) and {beta}-endorphin (an {epsilon}-opioid receptor agonist) produce antinociception by activating different descending pain inhibitory systems. Second, {gamma}-irradiation attenuates the acute antinociceptive action of i.c.v. injected morphine, but not DPLPE (a {delta}-opioid receptor agonist), in mice. These findings prompted us to investigate the effect of {gamma}-irradiation on the antinociception produced by i.c.v. injected morphine and {beta}-endorphin in male ICR mice. In one group, mice were exposed to whole-body irradiation at a dose of 5 Gy from a {sup 60}Co {gamma}-source and the antinociceptive effects were tested 5, 30, 60,90 and 180 min after irradiation using the 1% acetic acid-induced writhing test (10 ml/kg). The antinociceptive effect was produced time-dependently and reached its maximum at 90 min after irradiation. Thus, time was fixed in the following studies. In another group, mice were irradiated with 5 Gy and tested 90 minutes later for antinociception produced by i.c.v. administration of morphine (50 and 100 ng/mouse) or {beta}-endorphin (31 ng/mouse). Irradiation significantly potentiated the antinociception produced by {beta}-endorphin. However, the antinociception produced by morphine was not affected by irradiation. These results demonstrate a differential sensitivity of {mu}- and {epsilon}-opioid receptors to {gamma}-irradiation, in addition, support the hypothesis that morphine and {beta}-endorphin administered supraspinally produce antinociception by different neuronal mechanisms. (author) 4. Use of dual-head gamma camera in radionuclide internal contamination monitoring on radiation workers from a nuclear medicine department International Nuclear Information System (INIS) Rodriguez-Laguna, A.; Brandan, M.E. 2008-01-01 As a part of an internal dosimetry program that is performed at the Mexican National Institute of Cancerology - Nuclear Medicine Department, in the present work we suggest a procedure for the routinely monitoring of internal contamination on radiation workers and nuclear medicine staff. The procedure is based on the identification and quantification of contaminating radionuclides in human body by using a dual-head whole-body gamma camera. The results have shown that the procedures described in this study can be used to implement a method to quantify minimal accumulated activity in the main human organs to evaluate internal contamination with radionuclides. The high sensitivity of the uncollimated gamma camera is advantageous for the routinely detection and identification of small activities of internal contamination. But, the null spatial resolution makes impossible the definition of contaminated region of interest. Then, the use of collimators is necessary to the quantification of incorporated radionuclides activities in the main human organs and for the internal doses assessment. (author) 5. Radiosensitivity of Prostate Cancer Cell Lines for Irradiation from Beta Particle-emitting Radionuclide ¹⁷⁷Lu Compared to Alpha Particles and Gamma Rays. Science.gov (United States) Elgqvist, Jörgen; Timmermand, Oskar Vilhelmsson; Larsson, Erik; Strand, Sven-Erik 2016-01-01 The purpose of the present study was to investigate the radiosensitivity of the prostate cancer cell lines LNCaP, DU145, and PC3 when irradiated with beta particles emitted from (177)Lu, and to compare the effect with irradiation using alpha particles or gamma rays. Cells were irradiated with beta particles emitted from (177)Lu, alpha particles from (241)Am, or gamma rays from (137)Cs. A non-specific polyclonal antibody was labeled with (177)Lu and used to irradiate cells in suspension with beta particles. A previously described in-house developed alpha-particle irradiator based on a (241)Am source was used to irradiate cells with alpha particles. External gamma-ray irradiation was achieved using a standard (137)Cs irradiator. Cells were irradiated to absorbed doses equal to 0, 0.5, 1, 2, 4, 6, 8, or 10 Gy. The absorbed doses were calculated as mean absorbed doses. For evaluation of cell survival, the tetrazolium-based WST-1 assay was used. After irradiation, WST-1 was added to the cell solutions, incubated, and then measured for level of absorbance at 450 nm, indicating the live and viable cells. LNCaP, DU145, and PC3 cell lines all had similar patterns of survival for the different radiation types. No significant difference in surviving fractions were observed between cells treated with beta-particle and gamma-ray irradiation, represented for example by the surviving fraction values (mean±SD) at 2, 6, and 10 Gy (SF2, SF6, and SF10) for DU145 after beta-particle irradiation: 0.700±0.090, 0.186±0.050 and 0.056±0.010, respectively. A strong radiosensitivity to alpha particles was observed, with SF2 values of 0.048±0.008, 0.018±0.006 and 0.015±0.005 for LNCaP, DU145, and PC3, respectively. The surviving fractions after irradiation using beta particles or gamma rays did not differ significantly at the absorbed dose levels and dose rates used. Irradiation using alpha particles led to a high level of cell killing. The results show that the beta-particle emitter 6. Survey of the 137Cs contamination in Belgium by in-situ gamma spectrometry, a decade after the Chernobyl accident. Science.gov (United States) Uyttenhove, J; Pommé, S; Van Waeyenberge, B; Hardeman, F; Buysse, J; Culot, J P 1997-10-01 The residual radiocesium concentration, nearly 10 y after the Chernobyl accident, is measured at different sites on the Belgian territory by means of in-situ gamma-spectrometry. A possible link between the rainfall at the beginning of May 1986 and the actual cesium concentration is investigated. The radiological impact of this contamination, even in the most affected regions in the Ardennes, is very small (<6 microSv y(-1)). 7. Effect of Pseudomonas contamination or antibiotic decontamination of the GI tract on acute radiation lethality after neutron or gamma irradiation International Nuclear Information System (INIS) Geraci, J.P.; Jackson, K.L.; Mariano, M.S. 1985-01-01 The influence of antibiotic decontamination of Pseudomonas contamination of the GI tract prior to whole-body neutron or gamma irradiation was studied. It was observed that for fission neutron doses greater than 5.5 Gy, cyclotron-produced neutron doses greater than 6.7 Gy, and 137Cs gamma-ray doses greater than 14.4 Gy, the median survival time of untreated rats was relatively constant at 4.2 to 4.5 days, indicating death was due to intestinal injury. Within the dose range of 3.5 to 5.5 Gy of fission neutrons, 4.9 to 6.7 Gy of cyclotron-produced neutrons, and 9.6 to 14.4 Gy of gamma rays, median survival time of these animals was inversely related to dose and varied from 12 to 4.6 days. This change in survival time with dose reflects a transition in the mechanisms of acute radiation death from pure hematopoietic, to a combination of intestinal and hematopoietic, to pure intestinal death. Decontamination of the GI tract with antibiotics prior to irradiation increased median survival time 1 to 5 days in this transitional dose range. Contamination of the intestinal flora with Pseudomonas aeruginosa prior to irradiation reduced median survival time 1 to 5 days in the same radiation dose range. Pseudomonas-contaminated animals irradiated within this transitional dose range had maximum concentrations of total bacteria and Pseudomonas in their livers at the time of death. However, liver bacteria concentration was usually higher in gamma-irradiated animals, due to a smaller contribution of hematopoietic injury in neutron-irradiated animals. The effects of both decontamination of the GI tract and Pseudomonas contamination of the GI tract were negligible in the range of doses in which median survival time was dose independent, i.e., in the pure intestinal death dose range 8. {beta} -carotene effect the induction of the sister chromatid exchanges (ICH) by gamma radiation in mouse radiosensibilized osseous marrow cells In vivo; Efecto del {beta}- caroteno la induccion de intercambios en las cromatidas hermanas (ICH) por radiacion gamma en celulas radiosensibilizadas de la medula osea de raton In vivo Energy Technology Data Exchange (ETDEWEB) Morales R, P.; Cruz V, V.L. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico). Dept. de Biologia 1997-07-01 The effect of {beta}- carotene over the ICH radioinduction in radiosensibilized with BrdU osseous marrow cells of mouse was determined In vivo. The treatment with 50 {mu}g {beta} carotene per se induces a significant increment in the ICH frequency and the pre or post-treatment with the same dose causes an additive effect in the ICH frequency produced by 0.62 Gy of gamma radiation. This implies that {beta}- carotene does not have radioprotective activity, under conditions which was developed this experiment. (Author) 9. BETA digital beta radiometer International Nuclear Information System (INIS) Borovikov, N.V.; Kosinov, G.A.; Fedorov, Yu.N. 1989-01-01 Portable transportable digital beta radiometer providing for measuring beta-decay radionuclide specific activity in the range from 5x10 -9 up to 10 -6 Cu/kg (Cu/l) with error of ±25% is designed and introduced into commercial production for determination of volume and specific water and food radioactivity. The device specifications are given. Experience in the BETA radiometer application under conditions of the Chernobyl' NPP 30-km zone has shown that it is convenient for measuring specific activity of the order of 10 -8 Cu/kg, and application of a set of different beta detectors gives an opportunity to use it for surface contamination measurement in wide range of the measured value 10. Phorbol ester and hydrogen peroxide synergistically induce the interaction of diacylglycerol kinase gamma with the Src homology 2 and C1 domains of beta2-chimaerin. Science.gov (United States) Yasuda, Satoshi; Kai, Masahiro; Imai, Shin-ichi; Kanoh, Hideo; Sakane, Fumio 2008-01-01 DGKgamma (diacylglycerol kinase gamma) was reported to interact with beta2-chimaerin, a GAP (GTPase-activating protein) for Rac, in response to epidermal growth factor. Here we found that PMA and H2O2 also induced the interaction of DGKgamma with beta2-chimaerin. It is noteworthy that simultaneous addition of PMA and H2O2 synergistically enhanced the interaction. In this case, PMA was replaceable by DAG (diacylglycerol). The beta2-chimaerin translocation from the cytoplasm to the plasma membrane caused by PMA plus H2O2 was further enhanced by the expression of DGKgamma. Moreover, DGKgamma apparently enhanced the beta2-chimaerin GAP activity upon cell stimulation with PMA. PMA was found to be mainly required for a conversion of beta2-chimaerin into an active form. On the other hand, H2O2 was suggested to induce a release of Zn2+ from the C1 domain of beta2-chimaerin. By stepwise deletion analysis, we demonstrated that the SH2 (Src homology 2) and C1 domains of beta2-chimaerin interacted with the N-terminal half of catalytic region of DGKgamma. Unexpectedly, the SH2 domain of beta2-chimaerin contributes to the interaction independently of phosphotyrosine. Taken together, these results suggest that the functional link between DGKgamma and beta2-chimaerin has a broad significance in response to a wide range of cell stimuli. Our work offers a novel mechanism of protein-protein interaction, that is, the phosphotyrosine-independent interaction of the SH2 domain acting in co-operation with the C1 domain. 11. Arylation of beta, gamma-unsaturated lactones by a Heck-Matsuda reaction: an unexpected route to aryldiazene butenolides and pyridazinones Energy Technology Data Exchange (ETDEWEB) Taylor, Jason G.; Correia, Carlos Roque D., E-mail: roque@iqm.unicamp.b [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Inst. de Quimica 2010-07-01 The palladium catalysed coupling of aryldiazonium salts with {beta}-{gamma}-unsaturated lactones under basic conditions has been investigated. Both (3H)-furanone and {alpha}-angelicalactone were evaluated as substrates in the Heck Matsuda reaction but both failed to afford the desired arylated butenolides. Under basic conditions, {beta}-{gamma}-unsaturated lactones generate highly nucleophilic enolates that preferentially undergo azo coupling reactions with arenediazonium salts to afford aryldiazene butenolides. The electronic and steric effect of the substituents on the aryldiazonium salt in the azo coupling reaction is described. Aryldiazene-lactone derivatives were obtained in good yields from a highly facile and straightforward procedure. An aminoisomaleimide was formed from (3H)-furanone and cyclized to the corresponding pyridazinones in modest yield. (author) 12. Angular dependence of Ll, L\\alpha$, L$\\beta$and L$\\gamma$X-ray differential and fluorescence cross-sections for Er, Ta, W, Au, Hg and Tl CERN Document Server Demir, L; Kurucu, Y; Karabulut, A; Sahin, Y; 10.1016/S0969-806X(02)00501-7 2003-01-01 Ll, L alpha , L beta and L gamma X-ray differential cross-sections, fluorescence cross-sections and L/sub i/-subshell ( sigma /sub L1/, sigma /sub L2/, and sigma /sub L3/) fluorescence cross-sections were measured for Er, Ta, W, Au, Hg, and Tl at an excitation energy of 59.6 keV using a Si(Li) detector. The differential cross-sections for these elements have been measured at different angles varying from 54 degrees to 153 degrees at intervals of 9 degrees . The Ll and L alpha groups in the L X-ray lines are found to be spatially anisotropic, while those in the L beta and L gamma peaks are isotropic. Experimental and theoretical values of L X-ray fluorescence cross- sections and L/sub i/-subshell X-ray fluorescence cross-sections were compared. (20 refs). 13. Influence of radiation-dose pattern from inhaled beta--gamma-emitting radionuclides on canine peripheral lymphocytes International Nuclear Information System (INIS) Jones, R.K.; Boecker, B.B.; Pickrell, J.A.; Hobbs, C.H.; McClellan, R.O. 1976-01-01 As part of studies assess the biological hazards associated with inhaled radionuclides, periodic hematologic evaluations were performed on beagle dogs given a single nose-only exposure to aerosols of beta--gamma-emitting isotopes. The physical form and specific radionuclides selected produced radiation-dose patterns representative of those which might be encountered in the event of human accidental exposures. Dogs received graded lung burdens of either 90 Y, 91 Y, 144 Ce, or 90 Sr, each in fused clay. Differences in the effective half-lives of these radionuclides resulted in a spectrum of cumulative radiation doses to lung delivered at a variety of dose rates. Since the form in which the radionuclides were inhaled was relatively insoluble, the lung and intrathoracic tissues represented the primary recipient of the dose. Regardless of the effective half-life of radionuclide retention, a dose-related depression of peripheral lymphocytes was observed at various times after inhalation exposure. The time at which maximum depression and subsequent recovery occurred, however, was most directly related to the effective half-life of the radionuclide. Of special interest was the persistence of lymphopenia through 2 1 / 2 years after exposure to 144 Ce and 90 Sr in fused clay where, other than tracheobronchial lymph nodes, the lymphoid tissue received very little radiation dose. The possible mechanisms responsible for lymphocyte depression from these various radiation-dose patterns are discussed 14. Production of beta-gamma coincidence spectra of individual radioxenon isotopes for improved analysis of nuclear explosion monitoring data Science.gov (United States) Haas, Derek Anderson Radioactive xenon gas is a fission product released in the detonation of nuclear devices that can be detected in atmospheric samples far from the detonation site. In order to improve the capabilities of radioxenon detection systems, this work produces beta-gamma coincidence spectra of individual isotopes of radioxenon. Previous methods of radioxenon production consisted of the removal of mixed isotope samples of radioxenon gas released from fission of contained fissile materials such as 235U. In order to produce individual samples of the gas, isotopically enriched stable xenon gas is irradiated with neutrons. The detection of the individual isotopes is also modeled using Monte Carlo simulations to produce spectra. The experiment shows that samples of 131mXe, 133 Xe, and 135Xe with a purity greater than 99% can be produced, and that a sample of 133mXe can be produced with a relatively low amount of 133Xe background. These spectra are compared to models and used as essential library data for the Spectral Deconvolution Analysis Tool (SDAT) to analyze atmospheric samples of radioxenon for evidence of nuclear events. 15. Shelf-life extension of minimally processed and gamma irradiated red beet (Beta vulgaris ssp. vulgaris L.), Cv. early wonder International Nuclear Information System (INIS) Hernandes, Nilber Kenup; Vital, Helio de Carvalho; Coneglian, Regina Celi Cavestre 2007-01-01 This work investigated the effects of gamma irradiation on the shelf-life extension and safety of minimally processed red beet (Beta vulgaris ssp. vulgaris L.) by performing microbiological, chemical and sensory analyses. Red beets were harvested 73 days after transplanting and their tuberous parts were minimally processed and separated in two groups: control (non-irradiated) and irradiated (0.5, 1.0 and 1.5 kGy). Tests for Salmonella sp., total and fecal coliforms, total count of aerobic mesophilic and lactic-acid bacteria were performed during the 21-day storage at 8 deg C. They indicated that the samples irradiated with 1.0 and 1.5 kGy remained in good conditions throughout storage while the unirradiated samples did not last 7 days. Chemical analyses indicated that the concentrations of vitamins B1 and B2 were not affected by irradiation. In contrast the amounts of fructose and glucose increased during storage while the one for sucrose decreased. In addition four series of sensory evaluations including appearance and aroma indicated that the samples irradiated with 1.0 and 1.5 kGy remained good for consumption for 20 days. Therefore it was concluded that the use of the doses of 1.0 and 1.5 kGy produced the best effects on the conservation of the samples without harming the sensory characteristics and nutritional constituents tested. (author) 16. Hearing and seeing meaning in noise: Alpha, beta, and gamma oscillations predict gestural enhancement of degraded speech comprehension. Science.gov (United States) Drijvers, Linda; Özyürek, Asli; Jensen, Ole 2018-05-01 During face-to-face communication, listeners integrate speech with gestures. The semantic information conveyed by iconic gestures (e.g., a drinking gesture) can aid speech comprehension in adverse listening conditions. In this magnetoencephalography (MEG) study, we investigated the spatiotemporal neural oscillatory activity associated with gestural enhancement of degraded speech comprehension. Participants watched videos of an actress uttering clear or degraded speech, accompanied by a gesture or not and completed a cued-recall task after watching every video. When gestures semantically disambiguated degraded speech comprehension, an alpha and beta power suppression and a gamma power increase revealed engagement and active processing in the hand-area of the motor cortex, the extended language network (LIFG/pSTS/STG/MTG), medial temporal lobe, and occipital regions. These observed low- and high-frequency oscillatory modulations in these areas support general unification, integration and lexical access processes during online language comprehension, and simulation of and increased visual attention to manual gestures over time. All individual oscillatory power modulations associated with gestural enhancement of degraded speech comprehension predicted a listener's correct disambiguation of the degraded verb after watching the videos. Our results thus go beyond the previously proposed role of oscillatory dynamics in unimodal degraded speech comprehension and provide first evidence for the role of low- and high-frequency oscillations in predicting the integration of auditory and visual information at a semantic level. © 2018 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc. 17. Application of chemiluminescence to the study of alpha, beta and gamma radiolysis of water International Nuclear Information System (INIS) Broudic, V.; Muzeau, B.; Jegou, C.; Bonnal, M.; Gavazzi, A.; Marques, C. 2004-01-01 In the frame of the French research program on the long-term behavior of spent nuclear fuel, experiments are conducted in ATALANTE to develop and validate models of spent fuel evolution in contact with an aqueous phase. One of the mechanisms that may govern intermediate or long-term alteration of the spent fuel matrix in a repository is the oxidizing dissolution by radiolysis products of water. Leaching experiments in de-aerated media requires the analysis of hydrogen peroxide, as a major product of water radiolysis, down to 10 -8 mol.L -1 . This work presents the results obtained using the chemiluminescence reaction of iso-luminol with H 2 O 2 , catalyzed by micro-peroxidase. Depending on the samples used, different types of radiolytic processes were studied: α radiolysis of water when leaching UO 2 pellets doped with alpha emitters, or γ radiolysis of water when leaching the same samples or spent fuel in a gamma field. Influences of operating conditions on the analytical results are discussed. (authors) 18. Assessment of organochlorine hydrocarbons transformation in contaminated agricultural products and foodstuffs under gamma-radiation Science.gov (United States) Mel'nikova, T. V.; Polyakova, L. P.; Oudalova, A. A. 2017-01-01 The problem of an estimation of organochlorinated pollutants transformation (particularly organochlorinated pesticides (OCP) and polychlorinated biphenyls (PCB)) under gamma-irradiation has become important in connection with radiation technologies application in the food industry. According to earlier researches, small doses of OCP lead to serious damages of an organism, comparable with damages from high doses. Among radiolysis products of OCP in model solutions various substances on a structure have been found out. Though of trace concentration of each of them, in sum with the initial pesticides residue they make up significant of mass contamination (as shown earlier up to 90% from initial OCP). In this work fish samples (bream) containing OCPs (15.20 ng/g of hexachlorocyclohexane isomers and 87.10 ng/g of DDT and its metabolites), as well as PCB (18.51 ng/g) were studied. The minced fish was irradiated at dose of 10 kGy with dose rate of 1.35 Gy/sec. Then, by methods of gas-liquid chromatography (GLC) and gas chromatography-mass spectrometry (GC-MS), it was found that the OCPs degradation varied from 3 up to 61% and the PCB degradation - 24-52%. Significant complication of chemical composition was shown comparing to the primary biological sample contamination. As a result of fish irradiation, secondary pollution appeared that included residues of primary organochlorine hydrocarbons and their radiation-induced metabolites. Among the investigated OCPs the most stable proved to be alfa-hexachlorocyclohexane (alfa-HCH), the least stable - DDT which corresponds to the previous findings about the radiation stability of OCPs in model solutions. Mass spectra of the irradiated samples of minced bream showed the presence of radiation metabolites of OCPs, that had also been found at irradiation of model solutions of 2,2-di(4-chlorophenyl)-1-chlorethylene (DDMU), DDD and 1a, 2e, 3e, 4e, 5e-pentahlorcyclohexane. There was revealed a decomposition product formed during the 19. Assessment of organochlorine hydrocarbons transformation in contaminated agricultural products and foodstuffs under gamma-radiation International Nuclear Information System (INIS) Mel’nikova, T V; Polyakova, L P; Oudalova, A A 2017-01-01 The problem of an estimation of organochlorinated pollutants transformation (particularly organochlorinated pesticides (OCP) and polychlorinated biphenyls (PCB)) under gamma-irradiation has become important in connection with radiation technologies application in the food industry. According to earlier researches, small doses of OCP lead to serious damages of an organism, comparable with damages from high doses. Among radiolysis products of OCP in model solutions various substances on a structure have been found out. Though of trace concentration of each of them, in sum with the initial pesticides residue they make up significant of mass contamination (as shown earlier up to 90% from initial OCP). In this work fish samples (bream) containing OCPs (15.20 ng/g of hexachlorocyclohexane isomers and 87.10 ng/g of DDT and its metabolites), as well as PCB (18.51 ng/g) were studied. The minced fish was irradiated at dose of 10 kGy with dose rate of 1.35 Gy/sec. Then, by methods of gas-liquid chromatography (GLC) and gas chromatography-mass spectrometry (GC-MS), it was found that the OCPs degradation varied from 3 up to 61% and the PCB degradation – 24-52%. Significant complication of chemical composition was shown comparing to the primary biological sample contamination. As a result of fish irradiation, secondary pollution appeared that included residues of primary organochlorine hydrocarbons and their radiation-induced metabolites. Among the investigated OCPs the most stable proved to be alfa-hexachlorocyclohexane (alfa-HCH), the least stable – DDT which corresponds to the previous findings about the radiation stability of OCPs in model solutions. Mass spectra of the irradiated samples of minced bream showed the presence of radiation metabolites of OCPs, that had also been found at irradiation of model solutions of 2,2-di(4-chlorophenyl)-1-chlorethylene (DDMU), DDD and 1a, 2e, 3e, 4e, 5e-pentahlorcyclohexane. There was revealed a decomposition product formed during 20. The radioactive equilibrium and determination methods for ratio e Ra/U; Desequilibrio Radiactivos-1. Metodo {sub {beta}}-{gamma}. Determinacion de la razon eRa/U. Valoracion del contenido en U{sub 3}O{sub 8} Energy Technology Data Exchange (ETDEWEB) Mingarro, E 1966-07-01 The main problems concerning the radioactive non-equilibrium on minerals and a simultaneous counting procedure for {beta}- and {gamma}- activities developed to solve those problems, are described. (Author) 1. Calculation of skin dose due to beta contamination using the new quantity of the ICRP 116: the local skin dose International Nuclear Information System (INIS) Bourgois, L.; Menard, S.; Comte, N. 2017-01-01 Values of the new protection quantity Local Skin Dose 'LSD', introduced by the International Commission on Radiological Protection (ICRP) Publication 116, were calculated for 134 β - or β + emitting radionuclides, using the Monte Carlo code MCNP6. Two types of source geometry are considered: a point source and disc-type surface contamination (the source is placed in contact with the skin). This new protection quantity is compared with the operational quantity H2 (0.07, 0 deg.), leading us to conclude that, in accordance with the rules of the ICRP, the operational quantity over-estimates the protection quantity to a reasonable extent, except in very rare cases for very low average beta energies. Thus, with the new skin model described in ICRP 116, there are no longer any major differences between the operational quantities and protection quantities estimated with the skin model described in ICRP 74. (authors) 2. Radiation protection in inhomogeneous beta-gamma fields and modelling of hand phantoms with MCNPX International Nuclear Information System (INIS) Blunck, Ch; Becker, F.; Hegenbart, L.; Heide, B.; Schimmelpfeng, J.; Urban, M. 2009-01-01 The usage of beta-radiation sources in various nuclear medicine therapies is increasing. Consequently, enhanced radiation protection measures are required, as medical staff more frequently handle high-activity sources required for therapy. Inhomogeneous radiation fields make it difficult to determine absorbed dose reliably. Routine monitoring with dosemeters does not guarantee any accurate determination of the local skin dose (LSD). In general, correction factors are used to correct for the measured dose and the maximum absorbed dose received. However, strong underestimations of the maximum exposure are possible depending on the individual handling the process and the reliability of dose measurements. Simulations can be used as a tool for a better understanding of the maximum possible exposure depending on the individual-related handling. While measurements reveal the overall dose during the entire irradiation time of the dosemeter, simulations help to analyse sequences of action. Hence, simulations allow for tracking the points of highest absorbed dose received during the handling process. In this respect, simulations were performed using the MCNPX software. In order to investigate the LSD, two hand phantoms were used, a model based on geometrical elements and a voxel hand. A typical situation of radio-synoviorthesis, i.e. handling a syringe filled with 90 Y, was simulated. The results of the simulations show that the annual dose limit may be exceeded within minutes at the position of maximum absorbed dose received and that finger-ring dosemeters measure significantly different doses depending on their wearing position. It is of essential importance to wear the dosemeter properly and to use suitable correction factors with respect to the individual. Simulations are a suitable tool for ensuring reliable dose determination and may help to derive recommendations regarding radiation protection measures. (authors) 3. Separation of alpha-, beta-, gamma-, delta-tocopherols and alpha-tocopherol acetate on a pentaerythritol diacrylate monostearate-ethylene dimethacrylate monolith by capillary electrochromatography. Science.gov (United States) Chaisuwan, Patcharin; Nacapricha, Duangjai; Wilairat, Prapin; Jiang, Zhengjin; Smith, Norman W 2008-06-01 This work reports the first use of a monolith with method development for the separation of tocopherol (TOH) compounds by CEC with UV detection. A pentaerythritol diacrylate monostearate-ethylene dimethacrylate (PEDAS-EDMA) monolithic column has been investigated for an optimised condition to separate alpha-, beta-, gamma- and delta-TOHs, and alpha-tocopherol acetate (TAc). The PEDAS-EDMA monolith showed a remarkably good selectivity for separation of the TOH isomers including the beta- and gamma-isomers which are not easily separated by standard C8 or C18 particle-packed columns. Retention studies indicated that an RP mechanism was involved in the separation on the PEDAS-EDMA column, but polar interactions with the underlying ester and hydroxyl groups enhanced the separation of the problematic beta- and gamma-isomers. Separation of all the compounds was achieved within 25 min using 3:10:87 v/v/v 100 mM Tris buffer (pH 9.3)/methanol/ACN as the mobile phase. The method was successfully applied to a pharmaceutical sample with recoveries from 93 to 99%. Intraday and interday precisions (%RSD) for peak area and retention time were less than 2.3. LODs for all four TOHs and TAc were below 1 ppm. 4. A new approach to beta-gamma coincidence counting. Advance report on the Samar electronic system; Informe preliminar del sistema Samar sistema automatico de medidas absolutas de Radionucleidos Energy Technology Data Exchange (ETDEWEB) Carlos, J E. de; Granados, C E 1972-07-01 In 4{pi} {beta}-{gamma} coincidence measurements, precision on the evaluation of coincidence counting losses is made difficult because of complex overlapping effects between the{beta}--and {gamma}-side dead times due to pre cursive counted events. In this context the SAMAR electronic system is aimed to give a precise way of automatic counting and reduce the need for calculated corrections. This report describes its configuration and basic features. The SAMAR has been conceived in such a manner that both beta and gamma chains are sharing a common and non extending dead-time which is simultaneously applied to both channels. The shared dead time is made to be the only one inserted throughout the chains. Overlapping effects vanish and the three counting channels have identical transmission ratios. A new dead-time circuit based on fast linear gates as blocking elements has been developed. Application of the two-oscillator Muller's method evidences a fully non-extending character. Automatism is implemented by using a live timer corrective channel controlling the counting scalers. (Author) 21 refs. 5. RBE [relative biological effectiveness] of tritium beta radiation to gamma radiation and x-rays analyzed by both molecular and genetic methods International Nuclear Information System (INIS) Lee, W.R. 1988-01-01 The relative biological effectiveness (RBE) of tritium beta radiation to 60 Co gamma radiation was determined using sex-linked recessive lethals (SLRL) induced in Drosophila melanogaster spermatozoa as the biological effect. The SLRL test, a measure of mutations induced in germ cells transmitted through successive generations, yields a linear dose-response curve in the range used in these experiments. From these ratios of the slopes of the 3 H beta and the 60 Co gamma radiation linear dose response curves, an RBE of 2.7 is observed. When sources of error are considered, this observation suggests that the tritium beta particle is 2.7 ± 0.3 times more effective per unit of energy absorbed in inducing gene mutations transmitted to successive generation than 60 Co gamma radiation. Ion tracks with a high density of ions (high LET) are more efficient than tracks with a low ion density (low LET) in inducing transmissible mutations, suggesting interaction among products of ionization. Molecular analysis of x-ray induced mutations shows that most mutations are deletions ranging from a few base pairs as determined from sequence data to multi locus deletions as determined from complementation tests and Southern blots. 14 refs., 1 fig 6. A new approach to beta-gamma coincidence counting. Advance report on the Samar electronic system; Informe preliminar del sistema Samar sistema automatico de medidas absolutas de Radionucleidos Energy Technology Data Exchange (ETDEWEB) Carlos, J. E. de; Granados, C. E. 1972-07-01 In 4{pi} {beta}-{gamma} coincidence measurements, precision on the evaluation of coincidence counting losses is made difficult because of complex overlapping effects between the{beta}--and {gamma}-side dead times due to pre cursive counted events. In this context the SAMAR electronic system is aimed to give a precise way of automatic counting and reduce the need for calculated corrections. This report describes its configuration and basic features. The SAMAR has been conceived in such a manner that both beta and gamma chains are sharing a common and non extending dead-time which is simultaneously applied to both channels. The shared dead time is made to be the only one inserted throughout the chains. Overlapping effects vanish and the three counting channels have identical transmission ratios. A new dead-time circuit based on fast linear gates as blocking elements has been developed. Application of the two-oscillator Muller's method evidences a fully non-extending character. Automatism is implemented by using a live timer corrective channel controlling the counting scalers. (Author) 21 refs. 7. The diagnosis of the gastric cancer using catheter-type semiconductor radiation detector. Comparison of diagnostic values of. beta. -emitting radionuclide label with. gamma. -emitting label Energy Technology Data Exchange (ETDEWEB) Sassa, R; Iwase, T [Asahi Life Foundation, Tokyo (Japan). Inst. for Adult Diseases; Sugita, T; Iio, M 1975-06-01 The diagnostic usefulness of /sup 32/P-phosphate for human gastric cancer, using a catheter-type semiconductor radiation detector (CASRAD) combined with gastrofiberscope technique, has already been reported by the authors. They have in addition used sup(99m)Tc-bleomycin, sup(99m)Tc-tetracycline in the diagnosis of experimental rabbit gastric cancer, too. In the present study, further refinement of the technique for the ..beta..-ray labeled substance (/sup 32/P-phosphate) for detection of the gastric cancer was compared with that of ..gamma..-ray labeled substance (sup(99m)Tc-tetracycline). A more correct diagnosis of the gastric cancer by in vivo measurement of beta activity could be obtained, when the collimater, made of stainless steel, was attached to the top of the detector. In this way contribution to the count from the adjacent tissues or organs could be eliminated. They were unable to produce an effective and useful collimater for ..gamma..-ray labeled substance which could to be used safely in vivo. Because of the unsatisfactory collimater, radioactivities of the adjacent organs caused on increase in the radioactivity of the background. Therefore inspite of the recent introduction of various sup(99m)Tc-tumor agents, these labels were not applicable to the CASRAD method. For such a small detector system, ..beta..-labels, represented by /sup 32/P-phosphate, was still prefererable to ..gamma..-labels. 8. Gamma irradiation effect and time of storage on the beta-carotene rate of dehydrated parsley International Nuclear Information System (INIS) Sebastiao, K.I.; Romanelli, M.F.; Leite, Q.R.; Koseki, P.M.; Hamasaki, K.; Villavicencio, A.L.C.H.; Almeida-Muradian, L.B. 2000-01-01 The A vitamin is an essential nutrient for men. Therefore, this vitamin or one of its precursors must be ingested for a healthful diet. The carotenoids are also called pro-vitamin A. As any another carotenoid, the β-carotene has a structure with many unsaturations, conferring certain instability. It can be modified and even destroyed for acid, light, heat, oxygen; the formation of cis-trans isomers, reduction of its color and its pro-vitacimin A activity reduction can happen. Those alterations can occur during the processing or storage of the food. The use of the ionizing radiation is a kind of food processing that consists of the use of the high energy of the gamma ray or accelerates electrons, capable to ionize molecules. The carotenoids are considered by literature little sensible to the irradiation. It is suggested doses of 1 to 10 kGy in the irradiation of spices, dehydrated condiments and vegetables. These doses are enough to eliminate or to reduce pathogenic microorganisms and insects, to magnify the time of useful life and still substitute the use of chemical fumigants. They also reveal adequate to the organoleptic aspect, not affecting its flavor and smell. This study had as objective to search the different β-carotene levels in samples of dehydrated parsley submitted to the radiation of 60 Co and stored by 6 months. The results gotten in first analysis had not indicated difference significant statistics in β-carotene rate between the controlled sample and the radiated one. After 6 months of storage, were verified that the β-carotene rate had fallen for the half in both samples 9. Effect of gamma-irradiation on the levels of total and cis/trans isomers of beta-carotene in dehydrated parsley Energy Technology Data Exchange (ETDEWEB) Sebastiao, K.I. E-mail: kisebas@net.ipen.br; Almeida-Muradian, L.B. E-mail: ligiabi@usp.br; Romanelli, Maria Fernanda; Koseki, Paula Massae; Villavicencio, A.L.C.H. E-mail: villavic@net.ipen.br 2002-03-01 Ionizing radiation is a method for preservation of foods that use the high energy of gamma rays or accelerated electrons, thereby ionizing molecules. The most important precursor of vitamin A is {beta}-carotene, a carotenoid with pro-vitamin A activity. The highly unsaturated chain confers the instability of {beta}-carotene, and some reactions, as isomerisation, can reduce the characteristics of pro-vitamin A. The present study investigated whether increasing doses of 0, 10 and 20 kGy lower the total {beta}-carotene level and if an enhancement of cis-isomers occurred on samples of dehydrated parsley. No differences were observed of either fractions analyzed at doses applied in this study, nor did it contribute to the decrease of vitamin A. 10. Investigation of personnel beta and gamma dosimetry results at Amok Ltd, Cluff Lake International Nuclear Information System (INIS) Utting, R.E.; Brown, L.D.; Bradley, R.P. 1981-06-01 Apparent skin doses significantly higher than expected have been indicated by some thermoluminescent dosimeters worn by employees at Amok Ltd., Cluff Lake. Calculations have indicated that skin doses as a result of exposure to uranium ore are likely to be no more than twice the whole body doses. Experiments were conducted to expose TL dosimeters to a variety of radioactive materials commonly found in the mill environment under different conditions. The results of these experiments togethr with a re-examination of the original dosimeters leads to the conclusion that contamination either on or inside the dosimeter badge was the cause of the abnormal apparent skin doses. It is therefore recommended that for individuals with apparent skin doses in excess of twice the body dose, the actual skin dose should be considered to be equal to twice the body dose for purposes of determining compliance with the AEC Regulations. It is further recommended that the National Dose Registry records of anomalous skin doses to Amok employees be amended to reflect this. (author) 11. The measurement test of uranium in a uranium-contaminated waste by passive gamma-rays measurement method CERN Document Server Sukegawa, Y; Ohki, K; Suzuki, S; Yoshida, M 2002-01-01 This report is completed about the measurement test and the proofreading of passive gamma - rays measurement method for Non - destructive assay of uranium in a uranium-contaminated waste. The following are the results of the test. 1) The estimation of the amount of uranium by ionization survey meter is difficult for low intensity of gamma-rays emitted from uranium under about 50g. 2) The estimation of the amount of uranium in the waste by NaI detector is possible in case of only uranium, but the estimation from mixed spectrums with transmission source (60-cobalt) is difficult to confirm target peaks. 3) If daughter nuclides of uranium and thorium chain of uranium ore exist, measurement by NaI detector is affected by gamma-rays from the daughter nuclides seriously-As a result, the estimation of the amount of uranium is difficult. 4) The measurement of uranium in a uranium-contaminated waste by germanium detector is possible to estimate of uranium and other nuclides. 5) As to estimation of the amount of uranium... 12. Development of a low cost, GPS-based upgrade to a standard handheld gamma detector for mapping environmental radioactive contamination International Nuclear Information System (INIS) Paridaens, J. 2006-01-01 A low cost extension to a standard handheld radiation monitor was developed, allowing one to perform outdoor georeferenced gamma measurements. It consists of a commercial wireless Bluetooth[reg] GPS receiver, a commercial RS-232 to Bluetooth[reg] converter combined with a standard Bluetooth[reg] enabled pocket personal computer (PPC). The system is intended for use in difficult to access areas, typically for foot campaigns. As the operator walks, a straightforward homemade visual basic program alternately reads GPS position and gamma dose rate into the PPC, creating a data log. This allows a single operator on foot to map between 50 and 200 ha of environmental radiation per day in very rugged areas, depending on the accessibility of the terrain and the detail required. On a test field with known contamination, a spatial precision of about 5-10 m was obtainable. The device was also used to reveal complex contamination patterns in the flooding zones of a radioactively contaminated small river 13. Development of a low cost, GPS-based upgrade to a standard handheld gamma detector for mapping environmental radioactive contamination Energy Technology Data Exchange (ETDEWEB) Paridaens, J. [Belgian Nuclear Research Centre, SCK.CEN, Boeretang 200, B2400 Mol (Belgium)]. E-mail: jparidae@sckcen.be 2006-02-15 A low cost extension to a standard handheld radiation monitor was developed, allowing one to perform outdoor georeferenced gamma measurements. It consists of a commercial wireless Bluetooth[reg] GPS receiver, a commercial RS-232 to Bluetooth[reg] converter combined with a standard Bluetooth[reg] enabled pocket personal computer (PPC). The system is intended for use in difficult to access areas, typically for foot campaigns. As the operator walks, a straightforward homemade visual basic program alternately reads GPS position and gamma dose rate into the PPC, creating a data log. This allows a single operator on foot to map between 50 and 200 ha of environmental radiation per day in very rugged areas, depending on the accessibility of the terrain and the detail required. On a test field with known contamination, a spatial precision of about 5-10 m was obtainable. The device was also used to reveal complex contamination patterns in the flooding zones of a radioactively contaminated small river. 14. Prevalence of cutaneous beta and gamma human papillomaviruses in the anal canal of men who have sex with women Directory of Open Access Journals (Sweden) Vitaly Smelov 2017-06-01 Full Text Available Background: Data regarding anal cutaneous HPV detection among HIV-positive and HIV-negative persons largely relies on studies among men who have sex with men in limited geographical settings. Understanding the distribution, determinants, and potential human health effects of anal cutaneous HPV types among men who have sex with women (MSW is important. Methods: Anal canal swab samples from 415 Russian MSW (384 HIV-negative and 31 HIV-positive were tested for 43 β-HPVs and 29 γ-HPVs, using a multiplex PCR combined with Luminex technology. Results: β-HPV was detected in 24.4% and γ-HPV in 15.9% of anal samples of all Russian MSW. In total, 34 β-HPV and 19 γ-HPV types were detected, with the most commonly detected β-HPV types being 110, 22 and 124 and the most common γ-HPV types being 95, 132 and 50. For both genera, being HIV-positive at the time of testing was a significant determinant of detection (74.2% for β-HPVs and 48.4% for γ-HPVs compared to 20.1% and 12.5% in HIV-negative MSW, respectively. Conclusions: A wide spectrum and moderate prevalence of anal β-HPV and γ-HPV types was found in our MSW study sample, suggesting that routes other than penile-anal intercourse may be important in cutaneous HPV transmission. Keywords: Anal cutaneous HPV, Beta-HPV, Gamma-HPV, HIV-negative MSW, Penile-anal, HPV transmission 15. Alpha, beta and gamma electrocorticographic rhythms in somatosensory, motor, premotor and prefrontal cortical areas differ in movement execution and observation in humans. Science.gov (United States) Babiloni, Claudio; Del Percio, Claudio; Vecchio, Fabrizio; Sebastiano, Fabio; Di Gennaro, Giancarlo; Quarato, Pier P; Morace, Roberta; Pavone, Luigi; Soricelli, Andrea; Noce, Giuseppe; Esposito, Vincenzo; Rossini, Paolo Maria; Gallese, Vittorio; Mirabella, Giovanni 2016-01-01 In the present study, we tested the hypothesis that both movement execution and observation induce parallel modulations of alpha, beta, and gamma electrocorticographic (ECoG) rhythms in primary somatosensory (Brodmann area 1-2, BA1-2), primary motor (BA4), ventral premotor (BA6), and prefrontal (BA44 and BA45, part of putative human mirror neuron system underlying the understanding of actions of other people) areas. ECoG activity was recorded in drug-resistant epileptic patients during the execution of actions to reach and grasp common objects according to their affordances, as well as during the observation of the same actions performed by an experimenter. Both action execution and observation induced a desynchronization of alpha and beta rhythms in BA1-2, BA4, BA6, BA44 and BA45, which was generally higher in amplitude during the former than the latter condition. Action execution also induced a major synchronization of gamma rhythms in BA4 and BA6, again more during the execution of an action than during its observation. Human primary sensorimotor, premotor, and prefrontal areas do generate alpha, beta, and gamma rhythms and differently modulate them during action execution and observation. Gamma rhythms of motor areas are especially involved in action execution. Oscillatory activity of neural populations in sensorimotor, premotor and prefrontal (part of human mirror neuron system) areas represents and distinguishes own actions from those of other people. This methodological approach might be used for a neurophysiological diagnostic imaging of social cognition in epileptic patients. Copyright © 2015 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved. 16. Influence of gamma radiation on the nutrition composition and contamination by aflatoxigenic Aspergillus on peanuts Energy Technology Data Exchange (ETDEWEB) Costa, Laury Francis; Silva, Edvane Borges da [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear; Oliveira, Idjane Santana de [Universidade Federal de Pernambuco (UFPE), Vitoria de Santo Antao, PE (Brazil). Centro Academico de Vitoria 2011-07-01 Care in food storage, such as temperature and humidity control, assist in the prevention of fungal diseases in peanuts. The development of filamentous fungi in food and feed can result in the production of toxins known as mycotoxins. Ionizing radiation can be used as a preventive method against food security, promoting the inhibition of sprouting, delayed maturation, reduced microbial load, elimination of pathogenic microorganisms, sterilization, disinfection in grains, cereals, fruits and spices. This study aimed to evaluate the effects of gamma radiation on the nutritional composition and growth inhibition of Aspergillus aflatoxigenic in samples of peanuts. Samples were collected directly of a small producer (Petrolandia-PE) and Pernambuco Central of Supply (CEASA) and then packed within / without pods and subjected to irradiation by cobalt-60 pump at doses of 0, 6, 9, 12 and 15 kGy, in triplicate. The material was divided into two parts: a) to conduct a nutritional analysis of non-irradiated and irradiated material, and b) for fungal analysis, before and after irradiation. The results showed that the samples originated from the CEASA-PE had the highest rates of contamination with peanut, not only subjected to irradiation, but also for those samples subjected to doses of 6, 9 and 12 kGy. The dose of 15 kGy was the most efficient in controlling Aspergillus aflatoxigenic for both origins because it failed to eliminate the action of fungi, regardless of treatments. Only one non-irradiated sample, originated from CEASA-PE, showed positive production of aflatoxins in LCA. There weren't differences in the values of the nutritional composition, with increasing radiation dose. Irradiation combined with good storage conditions, was a reliable process for conservation of peanuts, because it prevents the growth of fungi, particularly Aspergillus aflatoxigenic, also avoiding the production and subsequent presence of aflatoxin in food, making it safer for consumption 17. Influence of gamma radiation on the nutrition composition and contamination by aflatoxigenic Aspergillus on peanuts International Nuclear Information System (INIS) Costa, Laury Francis; Silva, Edvane Borges da; Oliveira, Idjane Santana de 2011-01-01 Care in food storage, such as temperature and humidity control, assist in the prevention of fungal diseases in peanuts. The development of filamentous fungi in food and feed can result in the production of toxins known as mycotoxins. Ionizing radiation can be used as a preventive method against food security, promoting the inhibition of sprouting, delayed maturation, reduced microbial load, elimination of pathogenic microorganisms, sterilization, disinfection in grains, cereals, fruits and spices. This study aimed to evaluate the effects of gamma radiation on the nutritional composition and growth inhibition of Aspergillus aflatoxigenic in samples of peanuts. Samples were collected directly of a small producer (Petrolandia-PE) and Pernambuco Central of Supply (CEASA) and then packed within / without pods and subjected to irradiation by cobalt-60 pump at doses of 0, 6, 9, 12 and 15 kGy, in triplicate. The material was divided into two parts: a) to conduct a nutritional analysis of non-irradiated and irradiated material, and b) for fungal analysis, before and after irradiation. The results showed that the samples originated from the CEASA-PE had the highest rates of contamination with peanut, not only subjected to irradiation, but also for those samples subjected to doses of 6, 9 and 12 kGy. The dose of 15 kGy was the most efficient in controlling Aspergillus aflatoxigenic for both origins because it failed to eliminate the action of fungi, regardless of treatments. Only one non-irradiated sample, originated from CEASA-PE, showed positive production of aflatoxins in LCA. There weren't differences in the values of the nutritional composition, with increasing radiation dose. Irradiation combined with good storage conditions, was a reliable process for conservation of peanuts, because it prevents the growth of fungi, particularly Aspergillus aflatoxigenic, also avoiding the production and subsequent presence of aflatoxin in food, making it safer for consumption. The 18. Generation of the beta-amyloid peptide and the amyloid precursor protein C-terminal fragment gamma are potentiated by FE65L1. Science.gov (United States) Chang, Yang; Tesco, Giuseppina; Jeong, William J; Lindsley, Loren; Eckman, Elizabeth A; Eckman, Christopher B; Tanzi, Rudolph E; Guénette, Suzanne Y 2003-12-19 Members of the FE65 family of adaptor proteins, FE65, FE65L1, and FE65L2, bind the C-terminal region of the amyloid precursor protein (APP). Overexpression of FE65 and FE65L1 was previously reported to increase the levels of alpha-secretase-derived APP (APPs alpha). Increased beta-amyloid (A beta) generation was also observed in cells showing the FE65-dependent increase in APPs alpha. To understand the mechanism for the observed increase in both A beta and APPs alpha given that alpha-secretase cleavage of a single APP molecule precludes A beta generation, we examined the effects of FE65L1 overexpression on APP C-terminal fragments (APP CTFs). Our data show that FE65L1 potentiates gamma-secretase processing of APP CTFs, including the amyloidogenic CTF C99, accounting for the ability of FE65L1 to increase generation of APP C-terminal domain and A beta 40. The FE65L1 modulation of these processing events requires binding of FE65L1 to APP and APP CTFs and is not because of a direct effect on gamma-secretase activity, because Notch intracellular domain generation is not altered by FE65L1. Furthermore, enhanced APP CTF processing can be detected in early endosome vesicles but not in endoplasmic reticulum or Golgi membranes, suggesting that the effects of FE65L1 occur at or near the plasma membrane. Finally, although FE65L1 increases APP C-terminal domain production, it does not mediate the APP-dependent transcriptional activation observed with FE65. 19. Quantitative relations between beta-gamma mixed-field dosimeter responses and dose-equivalent conversion factors according to the testing standard International Nuclear Information System (INIS) Gupta, V.P. 1982-08-01 The conventional two-element personnel dosimeters, usually having two thick TLD (thermoluminescent dosimetry) ribbons, are used extensively for radiation protection dosimetry. Many of these dosimeters are used for the measurement of beta and gamma radiation doses received in mixed beta-gamma fields. Severe limitations exist, however, on the relative magnitudes and energies of these fields that may be measured simultaneously. Moreover, due to a well-known energy dependence of these dosimeters, particularly for the beta-radiations, systematic errors will occur whenever the differences in workplaces and calibration radiation energies exist. A simple mathematical approach is presented to estimate the deep and shallow dose equivalent values at different energies for such dosimeters. The formulae correlate the dosimeter responses and dose equivalent conversion factors at different energies by taking into account the guidelines of the adopted ANSI Standard N13.11 and the dosimetry practices followed by most dosimeter processors. This standard is to be used in a mandatory testing program in the United States 20. Do we need an emergency planning for contamination with alpha or beta emitting materials and how should this be?; Brauchen wir eine Notfallschutzplanung fuer Kontaminationen mit Alpha- oder Beta-Strahlern und wie soll sie aussehen? Energy Technology Data Exchange (ETDEWEB) Gellermann, Rainer [Nuclear Control and Consulting GmbH, Braunschweig (Germany); Kueppers, Christian [Oeko-Institut e.V., Darmstadt (Germany); Urbach, Michael [Behoerde fuer Umwelt und Energie, Hamburg (Germany). Amt fuer Immissionsschutz und Betriebe; Schnadt, Horst; Lange, Florentin 2016-07-01 The emergency planning up to now was geared to the consequences of accidents in nuclear facilities. There were no planning guidelines like the recommendations for emergency planning in the vicinity of nuclear facilities for other radiological incidents. According to article 98 of the new European radiation protection standards the member states have to take care for the preparation of emergency plans fir the case of emergency exposure scenarios. The study discusses several scenarios that might induce alpha or beta contamination, existing approaches for guiding contamination values, intervention benchmarks, protection strategies including continuing public information, selected radionuclides that might be involved, exposure paths, guidance benchmarks for person decontamination, and recommendations for new emergency plans. 1. Bidirectional modulation of hippocampal gamma (20-80 Hz) frequency activity in vitro via alpha(α)- and beta(β)-adrenergic receptors (AR). Science.gov (United States) Haggerty, D C; Glykos, V; Adams, N E; Lebeau, F E N 2013-12-03 Noradrenaline (NA) in the hippocampus plays an important role in memory function and has been shown to modulate different forms of synaptic plasticity. Oscillations in the gamma frequency (20-80 Hz) band in the hippocampus have also been proposed to play an important role in memory functions and, evidence from both in vitro and in vivo studies, has suggested this activity can be modulated by NA. However, the role of different NA receptor subtypes in the modulation of gamma frequency activity has not been fully elucidated. We have found that NA (30 μM) exerts a bidirectional control on the magnitude of kainate-evoked (50-200 nM) gamma frequency oscillations in the cornu Ammonis (CA3) region of the rat hippocampus in vitro via activation of different receptor subtypes. Activation of alpha-adrenergic receptors (α-AR) reduced the power of the gamma frequency oscillation. In contrast, activation of beta-adrenergic receptors (β-AR) caused an increase in the power of the gamma frequency oscillations. Using specific agonists and antagonists of AR receptor subtypes we demonstrated that these effects are mediated specifically via α1A-AR and β1-AR subtypes. NA activated both receptor subtypes, but the α1A-AR-mediated effect predominated, resulting in a reversible suppression of gamma frequency activity. These results suggest that NA is able to differentially modulate on-going gamma frequency oscillatory activity that could result in either increased or decreased information flow through the hippocampus. Copyright © 2013 IBRO. Published by Elsevier Ltd. All rights reserved. 2. Targeted Recombinant Fusion Proteins of IFN gamma and Mimetic IFN gamma with PDGF beta R Bicyclic Peptide Inhibits Liver Fibrogenesis In Vivo NARCIS (Netherlands) Bansal, Ruchi; Prakash, Jai; De Ruiter, Marieke; Poelstra, Klaas 2014-01-01 Hepatic stellate cells (HSCs), following transdifferentiation to myofibroblasts plays a key role in liver fibrosis. Therefore, attempts to attenuate this myofibroblastic phenotype would be a promising therapeutic approach. Interferon gamma (IFN gamma) is a potent anti-fibrotic cytokine, but its 3. Instruments used to measure or check {alpha}, {beta}, {gamma} activity and neutron emission in the course of processing ore or irradiated fuel; Appareils de mesure ou de controle {alpha}, {beta}, {gamma}, n, des circuits des usines de traitement du minerai ou du combustible irradie Energy Technology Data Exchange (ETDEWEB) Blanc, A; Brunet, M; Kermagoret, M; Labeyrie, J; Roux, G; Vasseur, J; Weil, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires 1959-07-01 One of the methods checking ores in the course of treatment is the rapid quantitative determination of thorium. This measurement is carried out by means of a scintillation instrument which shows the {beta} and {alpha} coincidences of ThC and ThC'. The treatment of irradiated fuel is accompanied by a large number of radioactive checks relative to the performance of the fixation and elution operations of uranium in the ion exchangers, to the concentration of radioactivity of effluent sent from the plant into watercourses. The operations of fixation and elution of the uranium are checked automatically by an instrument which takes a sample of 5 cm{sup 3} of solution, evaporates it and measures its activity every 10 or 20 minutes. Plutonium concentrations are measured: - in the presence of strong {beta} {gamma} activities, by means of rotating cylinder detectors; - in the presence of weak {beta} {gamma} activities, by means of {alpha} detectors scanning a constant level liquid surface; - by means of fission chambers relatively insensitive to {gamma}. Fission product concentrations are measured by chambers, counters or scintillators, according to the amount of {gamma} activity present. Finally, the activity of effluent to be emptied into watercourses is checked by means of a scintillation instrument, which measures the {alpha} activity on the one hand, and on the other hand the {beta} {gamma} activity of residue from a 100 cm{sup 3} sample taken and evaporated in 20 minutes. (author) [French] Parmi les controles relatifs au minerai en cours de traitement, figure le dosage rapide de thorium. Cette mesure est realisee au moyen d'un appareillage a scintillation qui met en evidence la coincidence des emissions {beta} et {alpha} du ThC et du ThC'. Le traitement des combustibles irradies s'accompagne d'un grand nombre de controles radioactifs portant sur le fonctionnement des operations de fixation et d'elution de l'uranium dans les echangeurs d'ions, sur la concentration du 4. Supramodal Theta, Gamma, and Sustained Fields Predict Modality-specific Modulations of Alpha and Beta Oscillations during Visual and Tactile Working Memory. Science.gov (United States) van Ede, Freek; Jensen, Ole; Maris, Eric 2017-08-01 Flexible control over currently relevant sensory representations is an essential feature of primate cognition. We investigated the neurophysiological bases of such flexible control in humans during an intermodal working memory task in which participants retained visual or tactile sequences. Using magnetoencephalography, we first show that working memory retention engages early visual and somatosensory areas, as reflected in the sustained load-dependent suppression of alpha and beta oscillations. Next, we identify three components that are also load dependent but modality independent: medial prefrontal theta synchronization, frontoparietal gamma synchronization, and sustained parietal event-related fields. Critically, these domain-general components predict (across trials and within load conditions) the modality-specific suppression of alpha and beta oscillations, with largely unique contributions per component. Thus, working memory engages multiple complementary frontoparietal components that have discernible neuronal dynamics and that flexibly modulate retention-related activity in sensory areas in a manner that tracks the current contents of working memory. 5. Molecular determinants of desensitization and assembly of the chimeric GABA(A) receptor subunits (alpha1/gamma2) and (gamma2/alpha1) in combinations with beta2 and gamma2 DEFF Research Database (Denmark) Elster, L; Kristiansen, U; Pickering, D S 2001-01-01 Two gamma-aminobutyric acid(A) (GABA(A)) receptor chimeras were designed in order to elucidate the structural requirements for GABA(A) receptor desensitization and assembly. The (alpha1/gamma2) and (gamma2/alpha1) chimeric subunits representing the extracellular N-terminal domain of alpha1 or gamma......, as opposed to the staining of the (gamma2/alpha1)-containing receptors, which was only slightly higher than background. To explain this, the (alpha1/gamma2) and (gamma2/alpha1) chimeras may act like alpha1 and gamma2 subunits, respectively, indicating that the extracellular N-terminal segment is important...... for assembly. However, the (alpha1/gamma2) chimeric subunit had characteristics different from the alpha1 subunit, since the (alpha1/gamma2) chimera gave rise to no desensitization after GABA stimulation in whole-cell patch-clamp recordings, which was independent of whether the chimera was expressed... 6. Neuromagnetic beta and gamma oscillations in the somatosensory cortex after music training in healthy older adults and a chronic stroke patient. Science.gov (United States) Jamali, Shahab; Fujioka, Takako; Ross, Bernhard 2014-06-01 Extensive rehabilitation training can lead to functional improvement even years after a stroke. Although neuronal plasticity is considered as a main origin of such ameliorations, specific subtending mechanisms need further investigation. Our aim was to obtain objective neuromagnetic measures sensitive to brain reorganizations induced by a music-supported training. We applied 20-Hz vibrotactile stimuli to the index finger and the ring finger, recorded somatosensory steady-state responses with magnetoencephalography, and analyzed the cortical sources displaying oscillations synchronized with the external stimuli in two groups of healthy older adults before and after musical training or without training. In addition, we applied the same analysis for an anecdotic report of a single chronic stroke patient with hemiparetic arm and hand problems, who received music-supported therapy (MST). Healthy older adults showed significant finger separation within the primary somatotopic map. Beta dipole sources were more anterior located compared to gamma sources. An anterior shift of sources and increases in synchrony between the stimuli and beta and gamma oscillations were observed selectively after music training. In the stroke patient a normalization of somatotopic organization was observed after MST, with digit separation recovered after training and stimulus induced gamma synchrony increased. The proposed stimulation paradigm captures the integrity of primary somatosensory hand representation. Source position and synchronization between the stimuli and gamma activity are indices, sensitive to music-supported training. Responsiveness was also observed in a chronic stroke patient, encouraging for the music-supported therapy. Notably, changes in somatosensory responses were observed, even though the therapy did not involve specific sensory discrimination training. The proposed protocol can be used for monitoring changes in neuronal organization during training and will improve 7. Calculation of absorbed dose for skin contamination imparted by beta radiation through the VARSKIN modified code for 122 interesting isotopes for nuclear medicine, nuclear power plants and research International Nuclear Information System (INIS) Alvarez R, J.T. 1991-01-01 In this work the implementation of a modification of the VARSKIN code for calculation of absorbed dose for contamination in skin imparted by external radiation fields generated by Beta emitting is presented. The modification consists on the inclusion of 47 isotopes of interest even Nuclear Plants for the dose evaluation in skin generated by 'hot particles'. The approach for to add these isotopes is the correlation parameter F and the average energy of the Beta particle, with relationship to those 75 isotopes of the original code. The methodology of the dose calculation of the VARSKIN code is based on the interpolation, (and integration of the interest geometries: punctual or plane sources), of the distribution functions scaled doses in water for beta and electrons punctual sources, tabulated by Berger. Finally a brief discussion of the results for their interpretation and use with purposes of radiological protection (dose insurance in relation to the considered biological effects) is presented 8. beta-Arrestin Interacts with the Beta/Gamma Subunits of Trimeric G-Proteins and Dishevelled in the Wnt/Ca2+ Pathway in Xenopus Gastrulation Czech Academy of Sciences Publication Activity Database Seitz, K.; Dursch, V.; Harnoš, J.; Bryja, Vítězslav; Gentzel, M.; Schambony, A. 2014-01-01 Roč. 9, č. 1 (2014) E-ISSN 1932-6203 R&D Projects: GA ČR(CZ) GC204/09/J030 Grant - others:GA ČR(CZ) GA204/09/0498 Institutional support: RVO:68081707 Keywords : CONVERGENT EXTENSION MOVEMENTS * WNT SIGNALING PATHWAYS * WNT/BETA-CATENIN Subject RIV: BO - Biophysics Impact factor: 3.234, year: 2014 9. Early peroxisome proliferator-activated receptor gamma regulated genes involved in expansion of pancreatic beta cell mass Directory of Open Access Journals (Sweden) Vivas Yurena 2011-12-01 Full Text Available Abstract Background The progression towards type 2 diabetes depends on the allostatic response of pancreatic beta cells to synthesise and secrete enough insulin to compensate for insulin resistance. The endocrine pancreas is a plastic tissue able to expand or regress in response to the requirements imposed by physiological and pathophysiological states associated to insulin resistance such as pregnancy, obesity or ageing, but the mechanisms mediating beta cell mass expansion in these scenarios are not well defined. We have recently shown that ob/ob mice with genetic ablation of PPARγ2, a mouse model known as the POKO mouse failed to expand its beta cell mass. This phenotype contrasted with the appropriate expansion of the beta cell mass observed in their obese littermate ob/ob mice. Thus, comparison of these models islets particularly at early ages could provide some new insights on early PPARγ dependent transcriptional responses involved in the process of beta cell mass expansion Results Here we have investigated PPARγ dependent transcriptional responses occurring during the early stages of beta cell adaptation to insulin resistance in wild type, ob/ob, PPARγ2 KO and POKO mice. We have identified genes known to regulate both the rate of proliferation and the survival signals of beta cells. Moreover we have also identified new pathways induced in ob/ob islets that remained unchanged in POKO islets, suggesting an important role for PPARγ in maintenance/activation of mechanisms essential for the continued function of the beta cell. Conclusions Our data suggest that the expansion of beta cell mass observed in ob/ob islets is associated with the activation of an immune response that fails to occur in POKO islets. We have also indentified other PPARγ dependent differentially regulated pathways including cholesterol biosynthesis, apoptosis through TGF-β signaling and decreased oxidative phosphorylation. 10. Measurement of Time-Dependent CP-Violating Asymmetriesand Constraints on sin(2 beta+gamma) withPartial Reconstruction of B to D*-+pi+- Decays Energy Technology Data Exchange (ETDEWEB) Aubert, B. 2005-04-19 We present a measurement of the time-dependent CP-violating asymmetries in decays of neutral B mesons to the final states D*{sup {-+}}{pi}{sup {+-}}, using approximately 232 million B{bar B} events recorded by the BABAR experiment at the PEP-II e{sup +}e{sup -} storage ring. Events containing these decays are selected with a partial reconstruction technique, in which only the high-momentum {pi}{sup {+-}} from the B decay and the low-momentum {pi}{sup {-+}} from the D*{sup {-+}} decay are used. We measure the parameters related to 2{beta} + {gamma} to be a{sub D*{pi}} = -0.034 {+-} 0.014 {+-} 0.009 and c{sub D*{pi}}{sup {ell}} = -0.019 {+-} 0.022 {+-} 0.013. With some theoretical assumptions, we interpret our results in terms of the lower limits |sin(2{beta} + {gamma})| > 0.62 (0.35) at 68% (90%) confidence level. 11. The insecticide fipronil and its metabolite fipronil sulphone inhibit the rat alpha1beta2gamma2L GABA(A) receptor. Science.gov (United States) Li, P; Akk, G 2008-11-01 Fipronil is the active ingredient in a number of widely used insecticides. Human exposure to fipronil leads to symptoms (headache, nausea and seizures) typically associated with the antagonism of GABA(A) receptors in the brain. In this study, we have examined the modulation of the common brain GABA(A) receptor subtype by fipronil and its major metabolite, fipronil sulphone. Whole-cell and single-channel recordings were made from HEK 293 cells transiently expressing rat alpha1beta2gamma2L GABA(A) receptors. The major effect of fipronil was to increase the rate of current decay in macroscopic recordings. In single-channel recordings, the presence of fipronil resulted in shorter cluster durations without affecting the intracluster open and closed time distributions or the single-channel conductance. The alpha1V256S mutation, previously shown alleviate channel inhibition by inhibitory steroids and several insecticides, had a relatively small effect on channel block by fipronil. The mode of action of fipronil sulphone was similar to that of its parent compound but the metabolite was less potent at inhibiting the alpha1beta2gamma2L receptor. We conclude that exposure to fipronil induces accumulation of receptors in a novel, long-lived blocked state. This process proceeds in parallel with and independently of, channel desensitization. The lower potency of fipronil sulphone indicates that the conversion serves as a detoxifying process in mammalian brain. 12. Study and construction of a {beta}-spectrometer of uniform axial magnetic field fitted with a {beta}-{gamma} coincidence selector. Study of the {beta} spectra of {sup 32}P, {sup 203}Hg, {sup 198}Au. Measurement of the conversion coefficients of {sup 203}Ti and of {sup 198}Hg; Etude et realisation d'un spectrometre-{beta} a champ magnetique axial uniforme, muni d'un selecteur de coincidence {beta}-{gamma}. Etude des spectres {beta} du {sup 32}p, {sup 203}Hg, {sup 198}Au. Mesure des coefficients de conversion du {sup 203}Ti et du {sup 198}Hg Energy Technology Data Exchange (ETDEWEB) Parsignault, D [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires 1964-06-01 In the first part is given the principle of the beta spectrometer with uniform axial field using systematically the idea of caustics. The apparatus is described and its properties compared to those deduced from trajectory calculations. The {beta}-ray and {gamma}-ray detectors and the device for selecting coincidences with a 2 {tau} resolution of 5 nanoseconds are also presented. In the second part, the spectrometer is used for studying reference elements and the most accurate results are confirmed. The {beta} spectrum of {sup 60}Co has a statistical form with an accuracy of 1 per cent; the maximum energy E{sub 0} is 316.5 {+-} 1.5 keV. That of the 7/2 + {yields} 11/2 transition for {sup 137}Cs has a unique form, once forbidden. E{sub 0}= 522 {+-} 3 keV. Conversion coefficients {alpha}{sub k} = 96 {+-} 1 X 10{sup -3} {alpha}L + M + N = 20.9 {+-} 0.5 X 10{sup -3}. The two {beta} spectra of {sup 59}Fe, separated by coincidence with the gamma, have the statistical form E{sub 0} = 462 {+-} 2 keV (55.1 + 0,3 per cent) and E{sub 1} = 275 {+-} 4 keV (44.9 {+-} 0.3 per cent). It is then verified whether the l selection rule is apparent in the shape of the phosphorus 32 beta spectrum. It is found in fact that it is not of statistical shape and its shape coefficient is determined. For a theoretical interpretation it is necessary to have better approximations than those generally used and this interpretation will not be unique. This work has also made it possible to show that the source contains a small proportion of {sup 33}P. The study of the {sup 203}Hg {beta} spectrum followed by the 279 keV gamma spectrum is designed to determine the conversion coefficients. The interior spectrum of gold 198 is not of statistical shape either. The form coefficient is determined together with the conversion coefficients which are in slight disagreement with those calculated by Rose or Sliv. An interpretation of the spectrum is put forward which proposes an imperfect compensation for the 13. Study and construction of a {beta}-spectrometer of uniform axial magnetic field fitted with a {beta}-{gamma} coincidence selector. Study of the {beta} spectra of {sup 32}P, {sup 203}Hg, {sup 198}Au. Measurement of the conversion coefficients of {sup 203}Ti and of {sup 198}Hg; Etude et realisation d'un spectrometre-{beta} a champ magnetique axial uniforme, muni d'un selecteur de coincidence {beta}-{gamma}. Etude des spectres {beta} du {sup 32}p, {sup 203}Hg, {sup 198}Au. Mesure des coefficients de conversion du {sup 203}Ti et du {sup 198}Hg Energy Technology Data Exchange (ETDEWEB) Parsignault, D. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires 1964-06-01 In the first part is given the principle of the beta spectrometer with uniform axial field using systematically the idea of caustics. The apparatus is described and its properties compared to those deduced from trajectory calculations. The {beta}-ray and {gamma}-ray detectors and the device for selecting coincidences with a 2 {tau} resolution of 5 nanoseconds are also presented. In the second part, the spectrometer is used for studying reference elements and the most accurate results are confirmed. The {beta} spectrum of {sup 60}Co has a statistical form with an accuracy of 1 per cent; the maximum energy E{sub 0} is 316.5 {+-} 1.5 keV. That of the 7/2 + {yields} 11/2 transition for {sup 137}Cs has a unique form, once forbidden. E{sub 0}= 522 {+-} 3 keV. Conversion coefficients {alpha}{sub k} = 96 {+-} 1 X 10{sup -3} {alpha}L + M + N = 20.9 {+-} 0.5 X 10{sup -3}. The two {beta} spectra of {sup 59}Fe, separated by coincidence with the gamma, have the statistical form E{sub 0} = 462 {+-} 2 keV (55.1 + 0,3 per cent) and E{sub 1} = 275 {+-} 4 keV (44.9 {+-} 0.3 per cent). It is then verified whether the l selection rule is apparent in the shape of the phosphorus 32 beta spectrum. It is found in fact that it is not of statistical shape and its shape coefficient is determined. For a theoretical interpretation it is necessary to have better approximations than those generally used and this interpretation will not be unique. This work has also made it possible to show that the source contains a small proportion of {sup 33}P. The study of the {sup 203}Hg {beta} spectrum followed by the 279 keV gamma spectrum is designed to determine the conversion coefficients. The interior spectrum of gold 198 is not of statistical shape either. The form coefficient is determined together with the conversion coefficients which are in slight disagreement with those calculated by Rose or Sliv. An interpretation of the spectrum is put forward which proposes an imperfect compensation for the 14. Gamma irradiation effect and time of storage on the beta-carotene rate of dehydrated parsley; Efeito da irradiacao gama e tempo de estoque no teor de beta-caroteno de salsa desidratada Energy Technology Data Exchange (ETDEWEB) Sebastiao, K.I.; Romanelli, M.F.; Leite, Q.R.; Koseki, P.M.; Hamasaki, K.; Villavicencio, A.L.C.H. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Centro de Tecnologia das Radiacoes. Lab. de Analise e Deteccao de Alimentos]. E-mail: villavic@net.ipen.br; Almeida-Muradian, L.B. [Sao Paulo Univ., SP (Brazil). Faculdade de Ciencias Farmaceuticas]. E-mail: ligiabi@usp.br 2000-07-01 The A vitamin is an essential nutrient for men. Therefore, this vitamin or one of its precursors must be ingested for a healthful diet. The carotenoids are also called pro-vitamin A. As any another carotenoid, the {beta}-carotene has a structure with many unsaturations, conferring certain instability. It can be modified and even destroyed for acid, light, heat, oxygen; the formation of cis-trans isomers, reduction of its color and its pro-vitacimin A activity reduction can happen. Those alterations can occur during the processing or storage of the food. The use of the ionizing radiation is a kind of food processing that consists of the use of the high energy of the gamma ray or accelerates electrons, capable to ionize molecules. The carotenoids are considered by literature little sensible to the irradiation. It is suggested doses of 1 to 10 kGy in the irradiation of spices, dehydrated condiments and vegetables. These doses are enough to eliminate or to reduce pathogenic microorganisms and insects, to magnify the time of useful life and still substitute the use of chemical fumigants. They also reveal adequate to the organoleptic aspect, not affecting its flavor and smell. This study had as objective to search the different {beta}-carotene levels in samples of dehydrated parsley submitted to the radiation of {sup 60}Co and stored by 6 months. The results gotten in first analysis had not indicated difference significant statistics in {beta}-carotene rate between the controlled sample and the radiated one. After 6 months of storage, were verified that the {beta}-carotene rate had fallen for the half in both samples. 15. Fully automated system for Pu measurement by gamma spectrometry of alpha contaminated solid wastes International Nuclear Information System (INIS) Cresti, P. 1986-01-01 A description is given of a fully automated system developed at Comb/Mepis Laboratories which is based on the detection of specific gamma signatures of Pu isotopes for monitoring Pu content in 15-25 l containers of low density (0.1 g/cm 3 ) wastes. The methodological approach is discussed; based on experimental data, an evaluation of the achievable performances (detection limit, precision, accuracy, etc.) is also given 16. Final Report for DUSEL R&D: BetaCage: A Screener of Ultra-Low-Level Radioactive Surface Contamination Energy Technology Data Exchange (ETDEWEB) Golwala, Sunil R. [California Institute of Technology 2013-12-20 The eventual full-size, radiopure BetaCage will be a low-background, atmospheric-pressure neon drift chamber with unprecedented sensitivity to emitters of low-energy electrons and alpha particles. We expect that the prototype BetaCage already developed will be an excellent screener of alpha particles. Both the prototype and final BetaCage will provide new infrastructure for rare-event science. 17. Task-related activity in sensorimotor cortex in Parkinson’s disease and essential tremor: changes in beta and gamma bands Directory of Open Access Journals (Sweden) Nathan C Rowland 2015-09-01 Full Text Available In Parkinson’s disease patients in the OFF medication state, basal ganglia local field potentials exhibit changes in beta and gamma oscillations that correlate with reduced voluntary movement, manifested as rigidity and akinesia. However, magnetoencephalography and low-resolution electrocorticography (ECoG studies in Parkinson’s patients suggest that changes in sensorimotor cortical oscillations differ from those of the basal ganglia. To more clearly define the role of sensorimotor cortex oscillatory activity in Parkinson’s, we performed intraoperative, high-resolution (4 mm spacing ECoG recordings in 10 Parkinson’s patients (2 females, ages 47-72 undergoing deep brain stimulation (DBS lead placement in the awake, OFF medication state. We analyzed ECoG potentials during a computer-controlled reaching task designed to separate movement preparation from movement execution and compared findings to similar invasive recordings in eight patients with essential tremor (3 females, ages 59-78, a condition not associated with rigidity or akinesia. We show that 1 cortical beta spectral power at rest does not differ between Parkinson’s and essential tremor patients (p = 0.85, 2 early motor preparation in Parkinson’s patients in the OFF medication state is associated with a larger beta desynchronization compared to patients with essential tremor (p = 0.0061, and 3 cortical broadband gamma power is elevated in Parkinson’s patients compared to essential tremor patients during both rest and task recordings (p = 0.004. Our findings suggest an oscillatory profile in sensorimotor cortex of Parkinson’s patients that, in contrast to the basal ganglia, may act to promote movement to oppose the anti-kinetic bias of the dopamine-depleted state. 18. Study of the transformation of uranium-niobium alloys with low niobium concentrations, tempered from the gamma and beta + gamma 1 regions and then annealed at different temperatures. Comparison with uranium-molybdenum alloys (1963); Etude des transformations des alliages uranium-niobium a faible teneur en niobium trempes depuis les domaines gamma et beta + gamma 1 puis revenus a differentes temperatures. Comparaison avec les alliages uranium-molybdene (1963) Energy Technology Data Exchange (ETDEWEB) Collot, C [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires 1962-09-15 The author shows that uranium-niobium alloys, like uranium-molybdenum alloys, tempered from the gamma region, give a martensitic phase with a structure deriving from that of alpha uranium by a slight contraction parallel to the axis [001], The critical cooling rate allowing the formation of this martensite is 80 deg. C/s at 750 deg. C. Retention of the beta phase of uranium-niobium alloys is particularly difficult, the critical retention rate being 700 deg. C/s at 668 deg. C for an alloy containing 2.5 at. per cent of Nb. This beta phase is completely converted to the alpha phase at room temperature in about 6 hours. The TTT curves of this beta alloy are effectively reduced to the lower branch of the lower 'C'. The beta phase conversion law is expressed as: 1-x = exp. (kt){sup n} x being the degree of progression of the conversion, t the time, n an exponent no-varying with temperature and having approximately the value 2 for the alloy considered, k an increasing function of temperature. The activation energy of conversion is of the order of 14,600 cal/mole. Niobium is much less active than molybdenum as a stabiliser of beta uranium. (author) [French] Dans ce travail l'auteur montre que les alliages uranium-niobium, comme d'ailleurs les alliages uranium-molybdene, trempes depuis le domaine gamma, donnent une phase martensitique dont la structure derive de celle de l'uranium alpha par une legere contraction parallele de l'axe [001]. La vitesse critique de refroidissement permettant la formation de cette martensite est de 80 deg. C/s a 750 deg. C. La retention de la phase beta des alliages uranium-niobium est particulierement delicate car la vitesse critique de retention est de 700 deg. C/s a 668 deg. C pour l'alliage a 2,5 at. pour cent de Nb. Cette phase beta se transforme completement en phase alpha a la temperature ordinaire en 6 heures environ. Les courbes TTT de cet alliage de structure beta se reduisent pratiquement a la branche inferieure du 'C' inferieur. La 19. First Accurate Normalization of the$\\beta$-delayed$\\alpha$Decay of$^{16}$N and Implications for the$^{12}$C$(\\alpha,\\gamma)^{16}$O Astrophysical Reaction Rate arXiv CERN Document Server Kirsebom, O.S.; Lica, R.; Munch, M.; Riisager, K.; Fynbo, H.O.U.; Borge, M.J.G.; Madurga, M.; Marroquin, I.; Andreyev, A.N.; Berry, T.A.; Christensen, E.R.; Fernández, P. Díaz; Doherty, D.T.; Van Duppen, P.; Fraile, L.M.; Gallardo, M.C.; Greenlees, P.T.; Harkness-Brennan, L.J.; Hubbard, N.; Huyse, M.; Jensen, J.H.; Johansson, H.; Jonson, B.; Judson, D.S.; Konki, J.; Lazarus, I.; Lund, M.V.; Marginean, N.; Marginean, R.; Perea, A.; Mihai, C.; Negret, A.; Page, R.D.; Pucknell, V.; Rahkila, P.; Sorlin, O.; Sotty, C.; Swartz, J.A.; Sørensen, H.B.; Törnqvist, H.; Vedia, V.; Warr, N.; De Witte, H. The$^{12}$C$(\\alpha,\\gamma)^{16}$O reaction plays a central role in astrophysics, but its cross section at energies relevant for astrophysical applications is only poorly constrained by laboratory data. The reduced$\\alpha$width,$\\gamma_{11}$, of the bound$1^-$level in$^{16}$O is particularly important to determine the cross section. The magnitude of$\\gamma_{11}$is determined via sub-Coulomb$\\alpha$-transfer reactions or the$\\beta$-delayed$\\alpha$decay of$^{16}$N, but the latter approach is presently hampered by the lack of sufficiently precise data on the$\\beta$-decay branching ratios. Here we report improved branching ratios for the bound$1^-$level and for$\\beta$-delayed$\\alpha$emission. In the case of the$\\beta$-delayed$\\alpha$branch, we find a$5\\sigma$deviation from the literature value. With our new branching ratios, the constraints imposed on$\\gamma_{11}$by the$\\beta\\alpha$-decay and$\\alpha-transfer data are of similar precision and, for the first time, in good agreement. Th... 20. Excitation of the isomeric states 1h sub 1 sub 1 sub / sub 2 in the nuclear reactions with gamma-quanta, neutrons and at beta decay CERN Document Server Belov, A G; Melnikova, L M; Ponomarev, V Yu; Tsoneva, N; Stoyanov, C; Balabanov, N P; Tonchev, A P 2001-01-01 The isomeric ratios (IR) were measured in the isotones with N = 81 ( sup 1 sup 3 sup 5 Xe, sup 1 sup 3 sup 7 Ba, sup 1 sup 3 sup 9 Ce, sup 1 sup 4 sup 1 Nd, and sup 1 sup 4 sup 3 Sm). Isomers with J suppi 11/2 sup - were excited in the reactions (n, gamma), (gamma, n), and beta sup + decay of sup 1 sup 3 sup 9 Pr and sup 1 sup 4 sup 1 Pm. The activation methods of gamma-spectrum measurement of reaction products was used. The marked difference of IR was observed in the isotones with the different atomic numbers Z but in the same reactions. The calculations of IR using low-level spectrum of final nuclei and probability of radiation transitions on the base of the quasiparticle phonon model were performed. The satisfactory agreement of the measured and calculated IR was obtained for all studied isotopes. The dependence of IR on Z is explained by the different energy of reaction and different probability levels population of the activation 1. Effects of Gamma-Irradiation on Microbial Contamination and on Histological Changes of Muscle in Poecilia reticulata Directory of Open Access Journals (Sweden) Katarína Beňová 2009-01-01 Full Text Available This study describes the effect of gamma-irradiation on the microbial skin and organ contamination and on the histological changes of fish skeletal musculature. The aquarium fish Poecilia reticulata were exposed to the radiation effect of 60Co at the doses of 20 and 30 Gy (11.36 Gy/min. Frequent intravital haemorrhages were observed from day 8 after the exposure. A general long-term body fading appeared from day 10 to day 30 of the experiment. Microbiological and histological examinations were done on days 7, 14, 21 and 28. Individual muscle cells were bound together into fascicles surrounded by connective tissue. No significant morphological changes were observed on skeletal muscle cells, except for more watery connective tissue. The presence of Escherichia coli and Aeromonas hydrophila was proved in the body surface samples and in aquarium water based on the microbiological test. A moderate increase of the number of E. coli and A. hydrophila was observed in the intestines in both exposed groups (20 and 30 Gy depending on the time that elapsed from the exposure (from 1 × 101 to 6 × 103 CFU. However, the heart, liver and musculature remained sterile. No microbial contamination of musculature was found for the intravital ionizing radiation dose of 30 Gy even for the single specimen killed on day 28 from the exposure. 2. Air contamination control as an element of state environmental monitoring International Nuclear Information System (INIS) Grabowski, D. 1993-01-01 The results of air contamination control on the base of gamma and beta radioactivity of aerosols collected on filters and in precipitation samples have been shown. The data have been gathered from 12 monitoring stations in Poland during 1993. No significant differences between actual results and those obtained in previous years have been noticed. 4 figs, 1 tab 3. Absorbed dose calculation from beta and gamma rays of 131I in ellipsoidal thyroid and other organs of neck with MCNPX code Directory of Open Access Journals (Sweden) Mohammad Mirzaie 2012-09-01 Full Text Available Background: The 131I radioisotope is used for diagnosis and treatment of hyperthyroidism and thyroid cancer. In optimized Iodine therapy, a specific dose must be reached to the thyroid gland with minimum radiation to the cervical spine, cervical vertebrae, neck tissue, subcutaneous fat and skin. Dose measurement inside the alive organ is difficult therefore the aim of this research was dose calculation in the organs by MCNPX code. Materials and Methods: First of all, the input file for MCNPX code has been prepared to calculate F6 and F8 tallies for ellipsoidal thyroid lobes with long axes is tow times of short axes which the 131I is distributed uniformly inside the lobes. Then the code has been run for F6 and F8 tallies for variation of lobe volume from 1 to 25 milliliters. From the output file of tally F6, the gamma absorbed dose in ellipsoidal thyroid, spinal neck, neck bone, neck tissue, subcutaneous fat layer and skin for the volume lobe variation from 1 ml to 25 ml have been derived and the graphs are drew. As well as, form the output of F8 tally the absorbed energy of beta in thyroid and soft tissue of neck is obtained and listed in the table and then absorbed dose of bate has been calculated. Results: The results of this research show that for constant activity in thyroid, the absorbed dose of gamma decreases about 88.3% in thyroid, 6.9% at soft tissue, 19.3% in adipose layer and 17.4% in skin, but it increases 32.1% in spinal of neck and 32.3% in neck bone when the lobe volume varied from 1 to 25 milliliters. For the same situation, the beta absorbed dose decreases 95.9% in thyroid and 64.2% in soft tissue. Conclusion: For the constant activity in thyroid by increasing the thyroid volume, absorbed dose of gamma in thyroid and soft tissue of neck, adipose layer under the skin and skin of neck decreased, but it increased at spinal of neck and neck bone. Also, by increasing of the lobe volume in constant activity, the beta absorbed dose 4. Study of formation of deep trapping mechanism by UV, beta and gamma irradiated Eu(3+) activated SrY2O4 and Y4Al2O9 phosphors. Science.gov (United States) Dubey, Vikas; Kaur, Jagjeet; Parganiha, Yogita; Suryanarayana, N S; Murthy, K V R 2016-04-01 This paper reports the thermoluminescence properties of Eu(3+) doped different host matrix phosphors (SrY2O4 and Y4Al2O9). The phosphor is prepared by high temperature solid state reaction method. The method is suitable for large scale production and fixed concentration of boric acid using as a flux. The prepared samples were characterized by X-ray diffraction technique and the crystallite size calculated by Scherer's formula. The prepared phosphor characterized by Scanning Electron Microscopic (SEM), Fourier Transform Infrared (FTIR), Energy Dispersive X-ray analysis (EDX), thermoluminescence (TL) and Transmission Electron Microscopic (TEM) techniques. The prepared phosphors for different concentration of Eu(3+) ions were examined by TL glow curve for UV, beta and gamma irradiation. The UV 254nm source used for UV irradiation, Sr(90) source was used for beta irradiation and Co(60) source used for gamma irradiation. SrY2O4:Eu(3+)and Y4Al2O9:Eu(3+) phosphors which shows both higher temperature peaks and lower temperature peaks for UV, beta and gamma irradiation. Here UV irradiated sample shows the formation of shallow trap (surface trapping) and the gamma irradiated sample shows the formation of deep trapping. The estimation of trap formation was evaluated by knowledge of trapping parameters. The trapping parameters such as activation energy, order of kinetics and frequency factor were calculated by peak shape method. Here most of the peak shows second order of kinetics. The effect of gamma, beta and UV exposure on TL studies was also examined and it shows linear response with dose which indicate that the samples may be useful for TL dosimetry. Formation of deep trapping mechanism by UV, beta and gamma irradiated Eu(3+) activated SrY2O4 and Y4Al2O9 phosphors is discussed in this paper. Copyright © 2015 Elsevier Ltd. All rights reserved. 5. A NIM (Nuclear Instrumentation Module) system conjugated with optional input for pHEMT amplifier for beta and gamma spectroscopy; Um sistema de modulos NIM conjugados com entrada opcional por amplificador pHEMT para espectroscopia beta e gama Energy Technology Data Exchange (ETDEWEB) Konrad, Barbara; Lüdke, Everton, E-mail: barbarakonradmev@gmail.com, E-mail: eludke@smail.ufsm.br [Universidade Federal de Santa Maria (LAE/UFSM), RS (Brazil). Lab. de Astrofisica e Eletronica 2014-07-01 This work presents a high speed NIM module (Nuclear Instrumentation Module) to detect radiation, gamma and muons, as part of a system for natural radiation monitoring and of extraterrestrial origin. The subsystem developed consists of a preamplifier and an integrated SCA (Single Channel Analyzer), including power supplies of ± 12 and ± 24V with derivations of +3.6 and ± 5V. The single channel analyzer board, consisting of discrete logic components, operating in window modes, normal and integral. The pulse shaping block is made up of two voltage comparators working at 120 MHz with a response time > 60 ns and a logic anticoincidence system. The preamplifier promotes a noise reduction and introduces the impedance matching between the output of anode / diode photomultiplier tubes (PMTs) and subsequent equipment, providing an input impedance of 1MΩ and output impedance of 40 to 140Ω. The shaper amplifier is non-inverting and has variable input capacitance of 1000 pF. The upper and lower thresholds of the SCA are adjustable from 0 to ± 10V, and the equipment is compatible with various types of detectors, like PMTs coupled to sodium iodide crystals. For use with liquid scintillators and photodiodes with crystals (CsI: Tl) is proposed to include a preamplifier circuit pHEMT (pseudomorphic High Electron Mobility Transistor) integrated. Yet, the system presents the possibility of applications for various purposes of gamma spectroscopy and automatic detection of events producing of beta particles. 6. Computer aided collimation gamma (Cacao): a new approach in measuring and visualizing the distribution of X and gamma ray emitters in contaminate wounds; Cacao (camera a collimation assistee par ordinateur): une nouvelle approche pour reconstruire et visualiser des contaminations d'emetteurs X et gamma dans les blessures Energy Technology Data Exchange (ETDEWEB) Douiri, A. [Hopital Pitie-Salpetriere (LENA), 75 - Paris (France); Jeanguillaume, C. [Centre Hospitalier Universitaire de Larrey, Service de Medecine Nucleaire, 49 - Angers (France); Franck, D.; Carlan, L. de [Institut de Radioprotection et de Surete Nucleaire, IRSN, Dept. de Protection de la Sante de l' Homme et de Dosimetrie, 92 - Fontenay aux Roses (France); Quartuccio, M.; Begot, S. [Faculte des Sciences d' Orsay (LPS), 91 - Orsay (France) 2003-07-01 The treatment of contaminated wounds can be greatly improved by visualizing the distribution of the radioactivity that is present. The low sensitivity of the conventional Anger camera means that it can only be used where there is a high level of activity. Moreover, these gamma cameras cannot make full use of the recent progress made in high spatial resolution semi-conductor detectors. In order to increase sensitivity while at the same time maintaining a sufficient resolution of the reconstructed image, the principle of the Computer aided collimation gamma camera (CACAO in French) was proposed as a possible means of using gamma cameras in intern dosimetry. This principle is based on the combined use of collimators with holes that are wider- than the intrinsic resolution of the detector, circular and linear scanning movements, a detector sensitive to the source depth and a specific reconstruction algorithm. This article presents the recent developments of the CACAO system and illustrates by a theoretical and experimental study, its performances compared with the classic tomography system. We start with a general overview of the CACAO system and its reconstruction algorithm. First of all, the superiority of the CACAO system is demonstrated by a simulation ,study. Then, an experimental bench was developed using an implanted silicon pixel detector specifically designed to allow the visualization of a subject contaminated with low energy X and gamma emitters. The study presented here shows images obtained from a phantom composed of three sources of Americium {sup 341}Am. Although the comparison between the conventional and CACAO approaches were not carried out with optimal parameters, especially for CACAO, the initial results show that CACAO has an improved sensitivity and a superior resolution. Finally, the transposition of this system to the practical study of contaminated wounds is discussed. (authors) 7. Studies on the preparation of immobilized enzymes by radio-polymerization, 10. Preparation of. beta. -galactosidase and its utilization for the continuous determination of lactose. [Gamma radiation Energy Technology Data Exchange (ETDEWEB) Amarakone, S P [Ceylon Inst. of Scientific and Industrial Research, Colombo (Sri Lanka); Hayashi, Toru; Kawashima, Koji 1983-03-01 ..beta..-Galactosidase of E. coli origin was immobilized in the form of beads by the radiopolymerization of different combinations of monomers using a gamma irradiation technique. With the dialysed enzyme, recoveries of over 300 % could be obtained on suitable monomer combinations containing magnesium and sodium acrylates. The recovery of the enzyme also depended on the irradiation time. The immobilized enzyme had better pH and temperature stability and was less affected by the presence of metal ions in the medium, compared to the native enzyme. The optimum pH and temperatures of the immobilized enzyme were different from those of the native enzyme and were 7.0 to 7.5 and 50 deg C respectively. The immobilized enzyme was used in a column for the continuous determination of lactose with a standard type autoanalyser. Good linearity could be observed even up to 3% lactose in the sample. 8. Controlling of bacterial flora contaminating animal diet and its components by gamma irradiation International Nuclear Information System (INIS) El-Fouly, M.Z.; El-Zawahry, Y.A.; Helal, G.A.; El-Hady, A.F. 1991-01-01 The total bacterial counts in complete diets were found to range between 10 3 -10 5 cells/g, which they ranged between 10 2 and 10 6 in the main components. One hundred and sixteen bacterial colonies were isolated from the animal diet samples and found to be gram positive belonging to three genera: Staphylococcus, Streptococcus and Bacillus. The most radioresistant bacteria isolated at 7.5 KGy were identified as B. megaterium, B. licheniformis, B. pumilus, B.circulans and B.laterosporus. The D 1 0 values for the bacteria contaminated the diet samples ranged between 928 Gy and 2199 Gy. Meanwhile, the D 1 0 values of staph.aureus and Strapt.faecalis artificially contaminated the diet were 400 Gy and 1136 Gy, respectively. It could be recommended from obtained results that dose level of 10 KGy is quite sufficient to eliminate all pathogens from animal diets or their components. In addition, it decreases the microbial count to minimum counts and hence increases the diet shelf life.1 fig.,4 tab 9. Influence of the. cap alpha. -,. beta. -, and. gamma. -subunits of the energy-transducing adenosine triphosphatase from Micrococcus lysodeikticus in the immunochemical properties of the protein and in their reconstitution studied by a radioimmunoassay method Energy Technology Data Exchange (ETDEWEB) Larraga, V; Mollinedo, F; Rubio, N; Munoz, E [Unidad de Biomembranas, Instituto de Inmunologia y Biologia Microbiana, Madrid (Spain) 1981-03-01 A sensitive radioimmunoassay was developed for the energy-transducing adenosine triphosphatase (F/sub 1/-ATPase, EC 3.6.1.3) of Micrococcus lysodeikticus and the assay was extended to the ..cap alpha..-, ..beta..-, and ..gamma..-subunits of the enzyme. These subunits were isolated and cross-reactions studied. 10. Immunoassay for Visualization of Protein-Protein Interactions on Ni-Nitrilotriacetate Support: Example of a Laboratory Exercise with Recombinant Heterotrimeric G[alpha][subscript i2][beta][subscript 1[gamma]2] Tagged by Hexahistidine from sf9 Cells Science.gov (United States) Bavec, Aljosa 2004-01-01 We have developed an "in vitro assay" for following the interaction between the [alpha][subscript i2] subunit and [beta][subscript 1[gamma]2] dimer from sf9 cells. This method is suitable for education purposes because it is easy, reliable, nonexpensive, can be applied for a big class of 20 students, and avoid the commonly used kinetic approach,… 11. Membranes of activated CD4+ T cells expressing T cell receptor (TcR) alpha beta or TcR gamma delta induce IgE synthesis by human B cells in the presence of interleukin-4 NARCIS (Netherlands) Gascan, H.; Aversa, G. G.; Gauchat, J. F.; van Vlasselaer, P.; Roncarolo, M. G.; Yssel, H.; Kehry, M.; Spits, H.; de Vries, J. E. 1992-01-01 In the present study it is demonstrated that human B cells can be induced to switch to IgE production following a contact-mediated signal provided by activated T cell receptor (TcR) gamma delta+, CD4+ and TcR alpha beta+, CD4+ T cell clones and interleukin (IL)-4. The signal provided by these T cell 12. Failure of gamma-aminobutyrate acid-beta agonist baclofen to improve balance, gait, and postural control after vestibular schwannoma resection. Science.gov (United States) De Valck, Claudia F J; Vereeck, Luc; Wuyts, Floris L; Van de Heyning, Paul H 2009-04-01 Incomplete postural control often occurs after vestibular schwannoma (VS) surgery. Customized vestibular rehabilitation in man improves and speeds up this process. Animal experiments have shown an improved and faster vestibular compensation after administration of the gamma-aminobutyrate acid (GABA)-beta agonist baclofen. To examine whether medical treatment with baclofen provides an improvement of the compensation process after VS surgery. A time-series study with historical control. Tertiary referral center. Thirteen patients who underwent VS resection were included and compared with a matched group of patients. In addition to an individualized vestibular rehabilitation protocol, the study group received medical treatment with 30 mg baclofen (a GABA-beta agonist) daily during the first 6 weeks after surgery. Clinical gait and balance tests (Romberg maneuver, standing on foam, tandem Romberg, single-leg stance, Timed Up & Go test, tandem gait, Dynamic Gait Index) and Dizziness Handicap Inventory. Follow-up until 24 weeks after surgery. When examining the postoperative test results, the group treated with baclofen did not perform better when compared with the matched (historical control) group. Repeated-measures analysis of variance revealed no significant group effect, but a significant time effect for almost all balance tests during the acute recovery period was found. An interaction effect between time and intervention was seen concerning single-leg stance and Dizziness Handicap Inventory scores for the acute recovery period. Medical therapy with baclofen did not seem to be beneficial in the process of central vestibular compensation. 13. Relationship between fungal contamination and ergosterol content and control of wheat grain spoilage by gamma rays International Nuclear Information System (INIS) Shahin, A.M.; Mahrous, S.R.; Aziz, N.H.; El-Zeany, S.M. 2003-01-01 The fungal flora and the ergosterol content of wheat grains were determined and the effect of gamma-irradiation on some important grain fungi to control mould spoilage of wheat grains was also investigated. At the start of storage, the ergosterol content and the number of moulds of wheat grains were 3.3μg/g and 3x10 3 /g, respectively and the technological values as germinative capacity and fat acidity were wholly satisfactory. After 50 days of storage, the ergosterol content and the number of moulds of the grains were 45.5 μg/g and 80x10 5 /g, respectively and all the germinative capacity and fat acidity values were not satisfactory. The ergosterol content of wheat grains irradiated at a dose level 3 kGy was 0.5 μg/g and the number of moulds were 8x10 2 /g. After 50 days of storage, the ergosterol content of the 3 kGy irradiated grains was 0.90 μg/g and the number of moulds were 15x10 2 /g and all the technological values were satisfactory. The fungal biomass and the ergosterol content of some grains fungi were decreased by increasing the irradiation dose levels. At irradiation dose level 4 kGy, there was no ergosterol in wheat grains and the moulds were completely inhibited and the technological values are wholly satisfactory over 50 days of storage 14. Analysis of drought-tolerant sugar beet (Beta vulgaris L.) mutants induced with gamma radiation using SDS-PAGE and ISSR markers. Science.gov (United States) Sen, Ayse; Alikamanoglu, Sema 2012-01-01 Drought is one of the major environmental stresses which greatly affect the plant growth and productivity. In the present study, various doses (0-75Gy) of gamma rays were applied to investigate the effect of radiation on shoot tip explants. It was observed that the regeneration rates and plant fresh weights decreased significantly with an increase in radiation dose. The optimal irradiation doses for mutation induction were determined at 15 and 20Gy. Afterwards, the induction of somatic mutation in sugar beet (Beta vulgaris L.) was investigated by irradiation of shoot tips with 15 and 20Gy gamma rays. Irradiated shoot tips were sub-cultured and M(1)V(1)-M(1)V(3) generations were obtained. Mutants tolerant to drought stress were selected on MS medium, supplemented with 10 and 20gl(-1) PEG6000. Of the M(1)V(3) plantlets, drought-tolerant mutants were selected. Leaf soluble proteins obtained from the control and drought-tolerant mutants were analyzed by SDS-PAGE. A total of 22 protein bands were determined and 2 of them were observed to be drought-tolerant mutants except the control. Polymorphism was also detected among the control and drought-tolerant mutants by DNA fingerprinting using ISSR markers. A total of 106 PCR fragments were amplified with 19 ISSR primers and 91 of them were polymorphic. The dendrograms were separated into two main clusters. First cluster included M8 mutant plant, which was applied 20Gy gamma radiation and regenerated on selective culture media containing 10gl(-1) PEG6000 concentration, and the second cluster was further divided into five sub-clusters. Copyright © 2012 Elsevier B.V. All rights reserved. 15. Analysis of drought-tolerant sugar beet (Beta vulgaris L.) mutants induced with gamma radiation using SDS-PAGE and ISSR markers International Nuclear Information System (INIS) Sen, Ayse; Alikamanoglu, Sema 2012-01-01 Drought is one of the major environmental stresses which greatly affect the plant growth and productivity. In the present study, various doses (0–75 Gy) of gamma rays were applied to investigate the effect of radiation on shoot tip explants. It was observed that the regeneration rates and plant fresh weights decreased significantly with an increase in radiation dose. The optimal irradiation doses for mutation induction were determined at 15 and 20 Gy. Afterwards, the induction of somatic mutation in sugar beet (Beta vulgaris L.) was investigated by irradiation of shoot tips with 15 and 20 Gy gamma rays. Irradiated shoot tips were sub-cultured and M 1 V 1 –M 1 V 3 generations were obtained. Mutants tolerant to drought stress were selected on MS medium, supplemented with 10 and 20 gl −1 PEG6000. Of the M 1 V 3 plantlets, drought-tolerant mutants were selected. Leaf soluble proteins obtained from the control and drought-tolerant mutants were analyzed by SDS-PAGE. A total of 22 protein bands were determined and 2 of them were observed to be drought-tolerant mutants except the control. Polymorphism was also detected among the control and drought-tolerant mutants by DNA fingerprinting using ISSR markers. A total of 106 PCR fragments were amplified with 19 ISSR primers and 91 of them were polymorphic. The dendrograms were separated into two main clusters. First cluster included M8 mutant plant, which was applied 20 Gy gamma radiation and regenerated on selective culture media containing 10 g l −1 PEG6000 concentration, and the second cluster was further divided into five sub-clusters. 16. Analysis of drought-tolerant sugar beet (Beta vulgaris L.) mutants induced with gamma radiation using SDS-PAGE and ISSR markers Energy Technology Data Exchange (ETDEWEB) Sen, Ayse, E-mail: senayse@istanbul.edu.tr [Istanbul University, Faculty of Science, Department of Biology, 34459 Vezneciler, Istanbul (Turkey); Alikamanoglu, Sema [Istanbul University, Faculty of Science, Department of Biology, 34459 Vezneciler, Istanbul (Turkey) 2012-10-15 Drought is one of the major environmental stresses which greatly affect the plant growth and productivity. In the present study, various doses (0-75 Gy) of gamma rays were applied to investigate the effect of radiation on shoot tip explants. It was observed that the regeneration rates and plant fresh weights decreased significantly with an increase in radiation dose. The optimal irradiation doses for mutation induction were determined at 15 and 20 Gy. Afterwards, the induction of somatic mutation in sugar beet (Beta vulgaris L.) was investigated by irradiation of shoot tips with 15 and 20 Gy gamma rays. Irradiated shoot tips were sub-cultured and M{sub 1}V{sub 1}-M{sub 1}V{sub 3} generations were obtained. Mutants tolerant to drought stress were selected on MS medium, supplemented with 10 and 20 gl{sup -1} PEG6000. Of the M{sub 1}V{sub 3} plantlets, drought-tolerant mutants were selected. Leaf soluble proteins obtained from the control and drought-tolerant mutants were analyzed by SDS-PAGE. A total of 22 protein bands were determined and 2 of them were observed to be drought-tolerant mutants except the control. Polymorphism was also detected among the control and drought-tolerant mutants by DNA fingerprinting using ISSR markers. A total of 106 PCR fragments were amplified with 19 ISSR primers and 91 of them were polymorphic. The dendrograms were separated into two main clusters. First cluster included M8 mutant plant, which was applied 20 Gy gamma radiation and regenerated on selective culture media containing 10 g l{sup -1} PEG6000 concentration, and the second cluster was further divided into five sub-clusters. 17. Improvement of a device for monitoring the contamination of surfaces International Nuclear Information System (INIS) Barbier, Albert. 1981-01-01 The purpose of this invention is to make it possible to monitor the contamination of surfaces by a light weight portable device and enabling the alpha, beta and gamma radiation contamination to be detected. The detection probe which is connected by a single lead to the box is adapted, in each particular case, to the radiation mode emitted by the contaminated surfaces and the box is provided with a special leak-proof socket for connecting the probe and includes means for assessing the counting rate of the radiation given off, depending on the mode of the radiations emitted by the contaminated surfaces and the intensity of the count rate [fr 18. Hand and foot contamination monitor International Nuclear Information System (INIS) Jakati, R.K.; Kaptral, R.S.; Ananthkrishnan, T.S.; Pansare, M.G. 1989-01-01 In order to make quick measurements of beta and gamma contaminations on hands and feet of personnel working in radioactive environments, hand and foot contamination monitors are widely used. This paper describes such a monitor system designed with Intel 8085 based microcomputer. The monitoring and warning system is designed to perform measurement of activity spread over surface of hands and soles of shoes or feet. Even though the system has many features to aid testing and maintainance operation, it is easy to use for unskilled persons. In order to check the contamination, the person stands on platform and inserts both his hands into detector assemblies thereby actuating the sensing switches. After a preset interval, annunciation of clean or contaminated status is declared by the system. (author) 19. Radioactivity of some alpha, beta and gamma emitting radionuclides in surface marine sediments of different bays in Algeria International Nuclear Information System (INIS) Noureddine, A.; Baggoura, B. 1999-01-01 Samples of surface (0-15) cm marine sediments of different grain sizes, namely sand, muddy and fine sand, were collected in the western, central and east coast of Algeria, to measure concentrations of natural and artificial radioactivity. The aim of this study is to detect any radioactive contamination, its origin and also to determine the uptake of radioactivity by marine surface sediments 20. Investigation of interaction of vanillin with Alpha, Beta and Gamma-cyclodextrin as drug delivery carriers: brief report Directory of Open Access Journals (Sweden) Batoolalsadat Mousavi Fard 2015-05-01 Methods: All theoretical calculations were performed on a Intel® Core™ i5 Processors computer at Kerman University using Gaussian 09 program package (Gaussian, Inc., Wallingford, USA in a three month period (February 2014 to May 2014. Starting geometries were generated employing GaussView software, version 5 (Gaussian, Inc., Wallingford, USA and then the resulting coordinates were optimized using density functional theory (DFT calculations. The natural bond orbital method (NBO program, under Gaussian 09 program package was carried out to study charge transfer energy associated with the intermolecular interactions. The quantum theory of atoms in molecules was applied for DFT results to get insight in the nature of interaction existing in the investigated systems. The calculations were carried out with AIM2000 program and AIMAll 14.10.27 package (Todd A. Keith, TK Gristmill software, Overland Park KS, USA to find and characterize bond critical points. Results: The vanillin molecule is adsorbed on the surface of carriers by hydrogen bonding between its oxygen atom and hydrogen atoms of cyclodextrin. The hydrogen of -OH group on the cyclodextrin can form hydrogen bond to the oxygen atom of carbonyl group of vanillin molecule. This study indicates a decrease of total energy with increasing surface of cyclodextrin. So gamma-cyclodextrin and its complex with the maximum surface in between carriers have the highest stabilities. The gamma-cyclodextrin shows the strongest interaction with vanillin. In all complexes of vanillin-cyclodextrin, the direction of charge transfer is from drug to carrier. Conclusion: Due to the high solubility of gamma-cyclodxtrin and its stronger interaction with the molecule vanillin, it can be the best option as drug carrier. 1. Double-beta decay measurement of 100Mo to the excited 01+ state of 100Ru in the NEMO3 experiment - R/D program for SuperNEMO: development of a BiPo detector to measure ultra low contaminations in the source foils International Nuclear Information System (INIS) Chapon, A. 2011-10-01 The NEMO3 detector was designed for the study of double beta decay and in particular the search for neutrinoless double beta decay (ββ0ν). The quantity of 100 Mo in the detector (7 kg) allows also a competitive measurement of the two-neutrino double beta decay (ββ2ν) of 100 Mo to the excited 0 1 + state of 100 Ru (eeNγ channel). Monte-Carlo simulations of the effect and of all the possible sources of background have been studied in order to determine their contributions to the full NEMO3 experimental data (2003-2011). These one have then been analysed: the ββ2ν decay half-life has been measured, and a limit on the ββ0ν decay has been obtained. Moreover, the SuperNEMO experiment aims to reach a sensitivity up to 10 26 years on the half-life of neutrinoless double beta decay. The SuperNEMO detector radioactivity has to be as low as possible. Especially radio-purity levels of 2 μBq*kg -1 in 208 Tl and 10 μBq*kg -1 in 214 Bi are required for the source foils. The gamma-spectrometry can not measure such low contamination levels. Hence, a BiPo dedicated detector has been developed to measure 208 Tl and 214 Bi contaminations, identifying the Bi→Po→Pb β-α chains. A proof of principle has been performed and the detector background has been measured. Assuming these values, a full BiPo detector of 3.6 m 2 can achieve the required sensitivities for the SuperNEMO source foils within six months of measurement. (author) 2. Correlation of gamma spectrometer measurements at surface with concentrations and distributions of subsurface radium contamination: Development, verification and application of methodology International Nuclear Information System (INIS) McCallum, B.A.; Clement, C.H.; Huffman, D.; Stager, R.H. 2000-01-01 This work is a step forward in the investigation of data gathering principles and analysis tools for improved estimates of subsurface radium contamination concentrations and distributions using surface gamma radiation spectra. Techniques to solve the inverse problem of estimating surface gamma radiation spectra given a fully known subsurface radium distribution have been investigated and applied with success. These techniques fell into three broad categories: empirical (using laboratory and field data), analytical (using mathematical derivations of relationships), and computer simulation (using Monte-Carlo photon transport simulation methods). Methods of analyzing surface spectra to estimate certain source parameters have been studied. The most fully developed methods are those involving the ratio of the areas of two peaks of differing energy from the same radionuclide to determine the source depth. For a point source of radium and its progeny, these techniques are able to reliably estimate the source depth from a single gamma radiation spectrum taken at the surface directly above the source. The only significant uncertainties in this case are the soil density and uncertainties introduced as a result of counting statistics. Further work remains to fully achieve the goals of the larger project: to develop a comprehensive suite of tools for the improved interpretation of surface gamma radiation spectra from subsurface distributions of radium contaminated soil. (author) 3. Folding control in cyclic peptides through N-methylation pattern selection: formation of antiparallel beta-sheet dimers, double reverse turns and supramolecular helices by 3alpha,gamma cyclic peptides. Science.gov (United States) Amorín, Manuel; Castedo, Luis; Granja, Juan R 2008-01-01 Peptide foldamers constitute a growing class of nanomaterials with potential applications in a wide variety of chemical, medical and technological fields. Here we describe the preparation and structural characteristics of a new class of cyclic peptide foldamers (3alpha,gamma-CPs) that, depending on their backbone N-methylation patterns and the medium, can either remain as flat rings that dimerize through arrays of hydrogen bonds of antiparallel beta-sheet type, or can fold into twisted double reverse turns that, in the case of double gamma-turns, associate in nonpolar solvents to form helical supramolecular structures. A 3alpha,gamma-CP consists of a number of multiples of a repeat unit made up of four amino acid residues of alternating chirality: three corresponding to alpha-amino acids and one to a gamma-amino acid (a cis-3-aminocycloalkanecarboxylic acid). 4. Control apparatus for radioactive contamination of the filtering device adapted on the protection apparatus of the respiratory tracts (1961); Appareil de controle de la contamination radioactive des dispositifs filtrants adaptes sur les appareils de protection des voies respiratoires (1961) Energy Technology Data Exchange (ETDEWEB) Dujancourt, S; Roche, J [Commissariat a l' Energie Atomique, Centre de Production de Plutonium, Marcoule (France). Centre d' Etudes Nucleaires 1961-07-01 That apparatus allows to detect and localize the radioactive contamination of the mask cartridge, for alpha, beta and gamma radiations, concerning external contamination, and for beta and gamma radiations, concerning internal contamination. It consists of lead coffin, in which the cartridge is inserted for control. Halogen counters are in contact with it. Operation conditions (Geiger or proportional) and their position on regard to the cartridge are controlled from outside. A sealer counts the pulses, given by the different counters. (authors) [French] Cet appareil permet de detecter et de localiser la contamination radioactive de cartouches filtrantes de masques, en {alpha}, {beta} et {gamma}, en ce qui concerne la contamination exterieure, et en {beta} et {gamma} en ce qui concerne la contamination interieure. Il est constitue par un coffre en plomb dans lequel est introduite la cartouche a controler. Des compteurs halogenes sont au contact de celle-ci. Leur regime de fonctionnement (Geiger ou proportionnel) et leur position par rapport a la cartouche sont commandes de l'exterieur. Une echelle de comptage compte les impulsions donnees par les differents compteurs. (auteurs) 5. Scaling of water vapor in the meso-gamma (2-20km) and lower meso-beta (20-50km) scales from tall tower time series Science.gov (United States) Pressel, K. G.; Collins, W.; Desai, A. R. 2011-12-01 Deficiencies in the parameterization of boundary layer clouds in global climate models (GCMs) remains one of the greatest sources of uncertainty in climate change predictions. Many GCM cloud parameterizations, which seek to include some representation of subgrid-scale cloud variability, do so by making assumptions regarding the subgrid-scale spatial probability density function (PDF) of total water content. Properly specifying the form and parameters of the total water PDF is an essential step in the formulation of PDF based cloud parameterizations. In the cloud free boundary layer, the PDF of total water mixing ratio is equivalent to the PDF of water vapor mixing ratio. Understanding the PDF of water vapor mixing ratio in the cloud free atmosphere is a necessary step towards understanding the PDF of water vapor in the cloudy atmosphere. A primary challenge in empirically constraining the PDF of water vapor mixing ratio is a distinct lack of a spatially distributed observational dataset at or near cloud scale. However, at meso-beta (20-50km) and larger scales, there is a wealth of information on the spatial distribution of water vapor contained in the physically retrieved water vapor profiles from the Atmospheric Infrared Sounder onboard NASA`s Aqua satellite. The scaling (scale-invariance) of the observed water vapor field has been suggested as means of using observations at satellite observed (meso-beta) scales to derive information about cloud scale PDFs. However, doing so requires the derivation of a robust climatology of water vapor scaling from in-situ observations across the meso- gamma (2-20km) and meso-beta scales. In this work, we present the results of the scaling of high frequency (10Hz) time series of water vapor mixing ratio as observed from the 447m WLEF tower located near Park Falls, Wisconsin. Observations from a tall tower offer an ideal set of observations with which to investigate scaling at meso-gamma and meso-beta scales requiring only the 6. Atomic layer deposition α-Al2O3 diffusion barriers to eliminate the memory effect in beta-gamma radioxenon detectors International Nuclear Information System (INIS) Warburton, W.K.; Wolfgang Hennig; Bertrand, J.A.; George, S.M.; Steven Biegalski 2013-01-01 Well designed scintillator detectors, including such examples as ARSA, SAUNA, and XIA's 'PhosWatch', can readily achieve the state of the art radioxenon detection limits required for nuclear explosion monitoring. They are also reliable, robust detectors that do not require cryogenic cooling for operation. All three employ the principle of beta-gamma coincidence detection to reduce background counting rates, using a BC-404 plastic scintillator to detect the betas and a CsI or NaI scintillator to detect the gamma-rays. As a consequence of this commonality of design, all three also display a 'memory effect' arising from the diffusion of Xe into BC-404. Thus, when one sample is pumped out of the detector, a fraction remains behind, embedded in the BC-404, where it artificially raises the signal counting rate for the next sample. While this is not a fatal flaw in scintillator detectors, developing a method to eliminate the memory effect would significantly enhance their utility. This paper reports efforts to develop thin, amorphous Al 2 O 3 films, deposited by atomic layer deposition (ALD) to act as diffusion barriers on the BC-404 surfaces exposed to radioxenon. Using radon as a convenient substitute for Xe, film thicknesses between 2 and 10 nm were originally investigated and found to show a memory effect to varying degrees. A second set of 20 and 30 nm films was then produced, which appeared to completely eliminate the radon memory effect, but, when consequentially tested with radioxenon, were found to exhibit xenon memory effects that were approximately half of the effect found on uncoated BC-404. We draw two conclusions from this result. The first is that it will be necessary to develop an improved method for depositing thicker ALD Al 2 O 3 films at lower temperatures while still retaining high film quality. The second is that, since xenon is required to test for the xenon memory effect, we need a test method that does not require xenon radio-isotopes in order to 7. Effect ALPHA Globalin Gene Deletion and GAMMA Globin Gene -158 (C/T) Polymorphism in BETA- Thalassaemic Patients International Nuclear Information System (INIS) EL Serafi, T.I.; Ismail, E.F.; Mahmoud, M.A.; Mohamed, M.A.; Ghattas, M.H.; Badran, D.I.; El Serafi, I.T.; Mohamed, H.S. 2008-01-01 The beta-thalassemias (β- thalassemias) are among the most common autosomal recessive disorders. They have a remarkably high frequency in the Mediterranean region and represent one of the most common genetic diseases in Egypt. In this study, the spectrum of P- thalassemia mutations and genotype-to-phenotype correlations were defined in 32 β- thalassaemic patients (β- thalassemias major and intermedia) with varying disease severity in two cities of the Suez Canal region. Ten different mutations were identified and the most frequent ones were: Isi-6 (T-C) (37.5%), IVSI-110 (G-A) (34.4%) and both IVSI-1 (G-A), IVSII-745 (C-G) and -102 (C-G) (12.5% each). There was a wide spectrum of phenotypic severity in all patients. We studied the Xmnl polymorphism (C/T) in γ- globin gene position -158 of P- thalassemia as a modulating factor of the disease severity. Presence of the polymorphism was found in two patients and this was not sufficient to explain the diversity of the phenotype encountered. Co-inheritance of alpha thalassaemia as a modulating factor was not evident in our patients. In conclusion, we have been unable to find a molecular basis for the benign clinical course in all our patients. Other genetic or acquired factors must be hypothesized which ameliorate the clinical condition. 8. Thermoluminescence response of new KClxBr1-x :EuCl3 sintered phosphors exposed to beta and gamma radiation International Nuclear Information System (INIS) Bernal, R.; Cruz-Zaragoza, E.; Cruz-Vazquez, C.; Burruel-Ibarra, S. E.; Rivera-Flores, M. J.; Barboza-Flores, M. 2006-01-01 Alkali halides crystals have been the subject of intense research for an understanding of their radiation-induced defects and luminescence properties. They exhibit noteworthy thermoluminescence (TL) properties when exposed to ionising radiation. Currently, these materials are grown employing expensive and rather complicated techniques. In this work, the results on the TL properties of new alkali halides phosphors fabricated by a simple and inexpensive procedure are presented. The samples were made by mixing KCl, KBr and EuCl 3 salts, and compressing them at a pressure of 3.2 x 10 7 Pa during 3 min, followed by sintering at 700 deg. C during 24 h under air atmosphere. The dosimetric response of the samples showed an increase with radiation dose in the 1.5-20.0 Gy dose range for beta and gamma radiation. The TL glow curves in sintered samples presented significant differences in their peak structures compared with monocrystalline samples, indicating that the nature of the trapping states and the recombination mechanisms may be different. (authors) 9. Use of low doses of cobalt 60 gamma radiation on beet (Beta vulgaris L.), carrot (Daucus carota L.) and radish (Raphanus sativus L.) seed to stimulate increase yield International Nuclear Information System (INIS) Bovi, Jose Eduardo 2000-01-01 The research had the aim of evaluating the effects of low doses of Cobalt-60 gamma radiation on seeds of radish (Raphanus sativus L.) cultiva Champion, cultivars Nantes Forto (european origin) and Brasilia (Rio Grande do Sul origin) carrot (Daucus carota L. var. sativus (Hoffm.) Thell), and red beet (Beta vulgaris L.) cultivar Tall Top Early Wonder before sowing, its effects on plant growth, on the yield and roots storage of two tillages: with sowing in the same day of radiation and six days after radiation seeds. The data showed that the seeds radiation did not interfered negatively on plants growth, and the species presented differences as roots production and doses on both plantation: radish with 5,0 Gy and 2,5 Gy doses respectively to the first and the second sowings, Brasilia carrot with 2,5 Gy dose to both sowings. Nantes carrot with 2,5 Gy and 5,0 Gy respectively to the first and the second sowings, and beet with 7,5 Gy and 5,0 Gy respectively to the first and the second plantations. There is not statistics difference by Tukey test (5% and 1%) and none relation between seeds radiation and loss weight on roots storage. (author) 10. Detection of clonal T-cell receptor beta and gamma chain gene rearrangement by polymerase chain reaction and capillary gel electrophoresis. Science.gov (United States) Fan, Hongxin; Robetorye, Ryan S 2013-01-01 Although established diagnostic criteria exist for mature T-cell neoplasms, a definitive diagnosis of a T-cell lymphoproliferative disorder cannot always be obtained using more conventional techniques such as flow cytometric immunophenotyping, conventional cytogenetics, fluorescence in situ hybridization, or immunohistochemistry. However, because T-cell malignancies contain identically rearranged T-cell receptor gamma (TCRG) and/or beta (TCRB) genes, the polymerase chain reaction (PCR) can be a fast, convenient, and dependable option to identify clonal T-cell processes. This chapter describes the use of PCR and capillary electrophoresis to identify clonal TCRB and TCRG gene rearrangements (TCRB and TCRG PCR) using a commercially available method employing multiple multiplex PCR tubes that was originally developed as the result of a large European BIOMED-2 collaborative study (Invivoscribe Technologies). The core protocol for the TCRB assay involves the use of three separate multiplex master mix tubes. Tubes A and B target the framework regions within the variable and joining regions of the TCRB gene, and Tube C targets the diversity and joining regions of the TCRB gene. The core protocol for the TCRG assay utilizes two multiplex master mix tubes (Tubes A and B) that target the variable and joining regions of the TCRG gene. Use of the five BIOMED-2 TCRB and TCRG PCR multiplex tubes in parallel can detect approximately 94% of clonal TCR gene rearrangements. 11. Background radiation accumulation and lower limit of detection in thermoluminescent beta-gamma dosimeters used by the centralized external dosimetry system International Nuclear Information System (INIS) Sonder, E.; Ahmed, A.B. 1991-12-01 A value for ''average background radiation'' of 0.75 mR/week has been determined from a total of 1680 thermoluminescent dosimeters (TLD's) exposed in 70 houses for periods up to one year. The distribution of results indicates a rather large variation among houses, with a few locations exhibiting backgrounds double the general average. Some discrepancies in the short-term background accumulation of TLD's have been explained as being due to light leakage through the dosimeter cases. In addition the lower limit of detection (L D ) for deep and shallow dose equivalents has been determined for these dosimeters. The L D for occupational exposure depends strongly on the time a dosimeter is exposed to background radiation in the field. The L D can vary from a low of 2.4 mrem for high energy gamma rays when the background accumulation period is less than a few weeks to values as high as 66 mrem for uranium beta particles when background has been allowed to accumulate for more than 21 weeks 12. {beta}-Delayed proton-decay study of {sup 20}Mg and its implications for the {sup 19}Ne(p,{gamma}){sup 20}Na breakout reaction in X-ray bursts Energy Technology Data Exchange (ETDEWEB) Wallace, J.P., E-mail: J.P.Wallace@sms.ed.ac.uk [University of Edinburgh, Edinburgh, EH9 3JZ (United Kingdom); Woods, P.J.; Lotay, G. [University of Edinburgh, Edinburgh, EH9 3JZ (United Kingdom); Alharbi, A.; Banu, A. [Cyclotron Institute, Texas A and M University, College Station, TX (United States); David, H.M.; Davinson, T. [University of Edinburgh, Edinburgh, EH9 3JZ (United Kingdom); McCleskey, M.; Roeder, B.T.; Simmons, E.; Spiridon, A.; Trache, L.; Tribble, R.E. [Cyclotron Institute, Texas A and M University, College Station, TX (United States) 2012-05-30 Under astrophysical conditions of high temperature and density, such as for example found in X-ray bursts, breakout can occur from the hot CNO cycles into the rapid proton capture process. A key breakout route is via the sequence {sup 15}O({alpha},{gamma}){sup 19}Ne(p,{gamma}){sup 20}Na. The {sup 19}Ne(p,{gamma}){sup 20}Na reaction rate is expected to be dominated by a single resonance at 457(3) keV. The identity of the resonance has been under discussion for a long time, with J{sup {pi}}=1{sup +} and 3{sup +} assignments suggested. In this study of the {beta}-delayed proton decay of {sup 20}Mg we report a new, significantly more stringent, upper limit on the {beta}-decay branch to this state of 0.02% with a confidence level of 90%. This makes a 1{sup +} assignment highly unlikely and favours a 3{sup +} assignment for which no branch is expected to be observed. The 3{sup +} state is predicted to have a significantly higher resonance strength, and to produce a proportionately higher {sup 19}Ne(p,{gamma}){sup 20}Na reaction rate in X-ray burst conditions. 13. Enhanced phytoremediation potential of polychlorinated biphenyl contaminated soil from e-waste recycling area in the presence of randomly methylated-{beta}-cyclodextrins Energy Technology Data Exchange (ETDEWEB) Shen Chaofeng [Institute of Environmental Science and Technology, Zhejiang University, Hangzhou 310029 (China); MOE Key Lab of Environmental Remediation and Ecosystem Health, College of Environmental and Resources Science, Zhejiang University, Hangzhou 310029 (China); Tang Xianjin; Cheema, Sardar Alam; Zhang Congkai; Khan, Muhammad Imran; Liang Fang; Chen Xincai; Zhu Youfeng [Institute of Environmental Science and Technology, Zhejiang University, Hangzhou 310029 (China); Lin Qi, E-mail: linqi@zju.edu.cn [Institute of Environmental Science and Technology, Zhejiang University, Hangzhou 310029 (China); Chen, Yingxu [Institute of Environmental Science and Technology, Zhejiang University, Hangzhou 310029 (China) 2009-12-30 The crude recycling of electronic and electric waste (e-waste) is now creating soil pollution problems with organic compounds such as polychlorinated biphenyls (PCBs). The present study aimed to compare the phytoremediation potential of four plant species (rice, alfalfa, ryegrass and tall fescue) for PCBs contaminated soil from Taizhou city, one of the largest e-waste recycling centers in China. In addition, the enhanced effects of randomly methylated-{beta}-cyclodextrins (RAMEB) on PCBs phytoremediation potential were evaluated. Higher PCBs removal percentages of 25.6-28.5% in rhizosphere soil were observed after 120 days, compared with those of the non-rhizosphere (10.4-16.9%) and unplanted controls (7.3%). The average PCBs removal percentages of four plant species increased from 26.9% to 37.1% in the rhizosphere soil with addition of RAMEB. Meanwhile, relatively high microbial counts and dehydrogenase activity were detected in planted soils and a stimulatory effect by RAMEB addition was found. The present study indicated that all the plant candidates were feasible for phytoremediation of PCBs contaminated soil from the e-waste recycling area, and tall fescue with RAMEB amendment seemed as a promising remediation strategy. High PCBs removal percentage was due to the increased PCBs bioavailability as well as biostimulation of microbial communities after plantation and RAMEB addition. 14. Evaluation of indigenously developed plastic scintillator sheet detector for surface radioactive contamination monitoring application International Nuclear Information System (INIS) Sahani, R.M.; Chaudhary, H.S.; Mahala, V.K.; Senwar, K.R.; Meena, J.P. 2018-01-01 Radioactive contamination may be caused by release of radioactivity in the environment due to accident at nuclear plant/reactor or spillage of loose radioactive materials in a laboratory. The protection of workers from potentially hazardous radiations emitted by the contaminants is a matter of prime concern. The detection of such radiations requires a monitoring system capable of measuring the level of radioactivity at the contaminated site. Plastic scintillators are widely used for large area radiation monitoring due to the ease of preparation in different shape and sizes. These detectors are sensitive to beta and gamma radiation therefore can be used for monitoring of beta and gamma contamination. In this paper, performance results of indigenously developed plastic scintillator sheet of area 800 cm 2 are reported 15. Radioactive contamination of the 30-km zone according to the sampling data within bench-marks of gamma-ray survey in 1991 International Nuclear Information System (INIS) Lesnoj, D.A.; Rybalko, S.I.; Solyanek, E.G. 1992-01-01 It is noted that formation of radioactive contamination of the Chernobyl' 30-km zone is conditioned by two main factors: state of operation of the reactor and movement of air masses within the period of 26.04.86 till 5.06.86. The analyses of formation of the radioactive traces in this period is presented. It is noted that ground radiometric and spectrometric investigations in 1991 according to the bench-marks with regard to gamma-ray survey of the 30-km zone make it possible to recognize 25% areas as having values close on background rates of the exposure doze in south-western and south-eastern sectors. However, these areas can be recommended for agricultural use after careful geochemical and hydrological mapping and inspecting settlements, plants and animals contamination. 1 tabs 16. Isozyme-specific enzyme inhibitors. 14. 5'(R)-C-[(L-homocystein-S-yl)methyl]adenosine 5'-(beta,gamma-imidotriphosphate), a potent inhibitor of rat methionine adenosyltransferases. Science.gov (United States) Kappler, F; Vrudhula, V M; Hampton, A 1987-09-01 The title compound is a covalent adduct of L-methionine (Met) and beta,gamma-imido-ATP. In its synthesis the N-Boc derivative of 5'(R)-C-(aminomethyl)-N6-benzoyl-5'-O-tosyl-2',3'-O- isopropylidenadenosine was converted by the successive actions of CF3CO2H and HNO2 into the corresponding 5'(R)-C-hydroxymethyl derivative. Treatment of this with disodium L-homocysteinate led to attack of sulfur at C6', apparently via a 5',6'-epoxide, and to total stereoselective inversion at C5' to furnish, after debenzoylation, 5'(R)-C-(L-homocystein-S-ylmethyl)-2',3'-O-isopropylidene ade nosine. The 5' configuration was established by conversion of this into the known 5'(S)-C-methyl-2',3'-O-isopropylidene adenosine with Raney nickel. The alpha-amino acid residue was protected as an N-Boc methyl ester, after which the 5'-hydroxyl was phosphorylated with benzyl phosphate and dicyclohexylcarbodiimide. The phosphoanhydride bond with inorganic imidodiphosphate was then created by established methods. Finally, blocking groups were removed under conditions that gave the desired adduct with no racemization of its L-methionine residue. It was a potent inhibitor [KM(ATP)/Ki = 1080; KM(Met)/Ki = 7.7] of the M-2 (normal tissue) form of rat methionine adenosyltransferase and of the M-T (hepatoma tissue) form [KM(ATP)/Ki = 670; KM(Met)/Ki = 22]. Inhibitions were competitive with respect to ATP or to L-methionine, indicating a dual substrate site mode of binding to the enzyme forms. 17. β-Arrestin interacts with the beta/gamma subunits of trimeric G-proteins and dishevelled in the Wnt/Ca(2+ pathway in xenopus gastrulation. Directory of Open Access Journals (Sweden) Katharina Seitz Full Text Available β-Catenin independent, non-canonical Wnt signaling pathways play a major role in the regulation of morphogenetic movements in vertebrates. The term non-canonical Wnt signaling comprises multiple, intracellularly divergent, Wnt-activated and β-Catenin independent signaling cascades including the Wnt/Planar Cell Polarity and the Wnt/Ca(2+ cascades. Wnt/Planar Cell Polarity and Wnt/Ca(2+ pathways share common effector proteins, including the Wnt ligand, Frizzled receptors and Dishevelled, with each other and with additional branches of Wnt signaling. Along with the aforementioned proteins, β-Arrestin has been identified as an essential effector protein in the Wnt/β-Catenin and the Wnt/Planar Cell Polarity pathway. Our results demonstrate that β-Arrestin is required in the Wnt/Ca(2+ signaling cascade upstream of Protein Kinase C (PKC and Ca(2+/Calmodulin-dependent Protein Kinase II (CamKII. We have further characterized the role of β-Arrestin in this branch of non-canonical Wnt signaling by knock-down and rescue experiments in Xenopus embryo explants and analyzed protein-protein interactions in 293T cells. Functional interaction of β-Arrestin, the β subunit of trimeric G-proteins and Dishevelled is required to induce PKC activation and membrane translocation. In Xenopus gastrulation, β-Arrestin function in Wnt/Ca(2+ signaling is essential for convergent extension movements. We further show that β-Arrestin physically interacts with the β subunit of trimeric G-proteins and Dishevelled, and that the interaction between β-Arrestin and Dishevelled is promoted by the beta/gamma subunits of trimeric G-proteins, indicating the formation of a multiprotein signaling complex. 18. Background compensation methodologies for contamination monitoring systems International Nuclear Information System (INIS) Raman, Anand; Chaudhury, Probal; Pradeepkumar, K.S. 2014-01-01 Radiation surveillance program in the various nuclear facilities incorporate contamination monitoring as an important component. Contamination monitoring programs constitute monitoring for alpha and beta contamination of the physical entities associated with the working personnel that include his hands, feet, clothing, shoes as well as the general surface areas in the working environment like floors. All these measurements are fraught with the contribution of the ambient gamma background radiation fields. These inhibit a proper and precise estimation of the contamination concentration being monitored. This paper investigates the efficacy of two methodologies that have been incorporated in two of the contamination monitoring systems developed in the Division. In the first system discussed, a high degree of gamma compensation has been achieved for an uniform exposure of the order of 50 nSv/hr to 100 mSv/hr. In the second system discussed, the degree of gamma compensation achieved is equal to those dictated by the statistical nature of the uncertainties associated with the subtraction of background from the source data. These two methods can be very effectively employed depending on the application requirement. A minimum detection level equivalent to 0.37 Bq/cdm 2 has been achieved in both these cases 19. Interferon gamma, interleukin 4 and transforming growth factor beta in experimental autoimmune encephalomyelitis in Lewis rats: dynamics of cellular mRNA expression in the central nervous system and lymphoid cells DEFF Research Database (Denmark) Issazadeh-Navikas, Shohreh; Mustafa, M; Ljungdahl, A 1995-01-01 , the target organ in EAE, cells expressing mRNA for IFN-gamma, first appeared at the onset of clinical signs, i.e., day 10 postimmunization (p.i.), peaked at the height of disease (day 13 p.i.) and then gradually decreased concomitant with recovery. Very few IL-4 mRNA-expressing cells appeared in the spinal...... to limit central nervous system (CNS) inflammation. In lymphoid organs, primed MBP 63-88 reactive T cells showed an interesting time-dependent evolution of their cytokine production in vitro. Thus, early after immunization there was a conspicuous MBP 63-88-induced production of both IFN-gamma and IL-4...... cord with no clear relation to clinical signs or histopathology. In contrast, expression of mRNA for TGF-beta did not increase until day 13 p.i., at height of the disease, shortly preceding recovery. These data are consistent with a disease upregulating role of IFN-gamma, while TGF-beta may act... 20. Microbiological studies on drugs and their raw materials, 4. Sterilization of microbial contaminants in enzyme powder by gamma irradiation Energy Technology Data Exchange (ETDEWEB) Sakai, T; Yoshida, Y; Demura, H; Yanagita, T [Toyama Univ. (Japan). Faculty of Pharmaceutical Sciences; Meiwa, M 1978-04-01 The decimal reduction dose of ..gamma..-ray on freeze-dried clean Escherichia coli (E. coli) cells and Bacillus subtilis spores was about 7 x 10/sup 4/ rad and it was about three times higher than that on E. coli cells suspended in saline. E. coli cells contained in Takadiastase or trypsin powder showed quite the same susceptibility of ..gamma..-irradiation as they were present cleanly. These enzyme activities were not impaired at all even at the dose of 2 x 10/sup 5/ rad. When these enzyme powders containing E. coli cells were stored under varied atmospheric relative humidity, the deleterious effect of ..gamma..-ray on bacterial cells was highly enhanced in those samples stored under more than 80.5% relative humidities. The additions of excipients, such as glucose and lactose, and of a protectant, L-cysteine, to the bacteria-containing dry enzyme powder did not show any sign of either enhancement or retardation of ..gamma..-ray action on enzyme and bacteria. Based on these observations, the utilizability of radiosterilization on biological medicaments is discussed. 1. Application of low-dose gamma irradiation to extend the shelf life of minimally processed Red Beet (Beta vulgaris sp. vulgaris L.), cv. Early Wonder International Nuclear Information System (INIS) Hernandez, Nilber Kenup 2006-01-01 This study was aimed at investigating the effects of low-dose gamma irradiation on shelf-life extension and phyto sanitary safety of minimally processed red beet with basis on physicochemical; microbiological; chemical and sensory analyses. The samples (Beta vulgaris ssp. vulgaris L.), Early Wonder cultivar, were cultivated in the experimental area of the Horticulture Sector of the Departamento de Fitotecnia of the Instituto de Agronomia, Universidade Federal Rural do Rio de Janeiro, Seropedica, RJ, as part of two experiments performed during the second semester of 2005. In each experiment, 1200 plants (40 per linear meter of terrain) were sowed. Physicochemical analyses (fresh mass; length; average diameter and total soluble solids) of the edible part of the red beets (their tuberous roots) were periodically carried out in order to assess the most appropriate time for harvest by monitoring the development of the plants. Those times were found to be 104 and 73 days after transplanting, respectively. The harvested edible part of the roots were minimally processed and separated in two groups: (1) gamma irradiated (with doses of 0.5; 1.0 and 1.5 kGy) and (2) non-irradiated (control). All samples were stored at 8 degree C. Microbiological analyses were performed during the storage period (22 and 21 days, for experiments 1 and 2, respectively) in order to evaluate the phyto sanitary quality of the samples (Salmonella sp.; coliforms and total count of mesophilic aerobic and lactic acid bacteria). The samples irradiated with 1.0 and 1.5 kGy were found to remain appropriate for consumption for 21 days, as compared to only 7 days for the control. Monitoring of chemical composition was also performed and included the determination of saccharose; glucose; fructose and vitamins B1 and B2. No difference was found between the concentrations of those vitamins in irradiated and control samples at the end of the storage period, whereas significant changes in sugar contents were 2. H2O2-Activated Mitochondrial Phospholipase iPLA2 gamma Prevents Lipotoxic Oxidative Stress in Synergy with UCP2, Amplifies Signaling via G-Protein-Coupled Receptor GPR40, and Regulates Insulin Secretion in Pancreatic beta-Cells Czech Academy of Sciences Publication Activity Database Ježek, Jan; Dlasková, Andrea; Zelenka, Jaroslav; Jabůrek, Martin; Ježek, Petr 2015-01-01 Roč. 23, č. 12 (2015), s. 958-972 ISSN 1523-0864 R&D Projects: GA ČR(CZ) GPP303/11/P320; GA ČR(CZ) GA13-02033S; GA ČR(CZ) GA13-06666S; GA ČR GA15-02051S Institutional support: RVO:67985823 Keywords : mitochondrial phospholipase iPLA2 gamma * uncoupling protein UCP2 * G-protein coupled receptor - 40 * glucose-stimulated insulin secretion * pancreatic beta cells Subject RIV: FB - Endocrinology, Diabetology, Metabolism, Nutrition Impact factor: 7.093, year: 2015 3. Development and Performance of Detectors for the Cryogenic Dark Matter Search Experiment with an Increased Sensitivity Based on a Maximum Likelihood Analysis of Beta Contamination Energy Technology Data Exchange (ETDEWEB) Driscoll, Donald D [Case Western Reserve Univ., Cleveland, OH (United States) 2004-05-01 The Cryogenic Dark Matter Search (CDMS) uses cryogenically-cooled detectors made of germanium and silicon in an attempt to detect dark matter in the form of Weakly-Interacting Massive Particles (WIMPs). The expected interaction rate of these particles is on the order of 1/kg/day, far below the 200/kg/day expected rate of background interactions after passive shielding and an active cosmic ray muon veto. Our detectors are instrumented to make a simultaneous measurement of both the ionization energy and thermal energy deposited by the interaction of a particle with the crystal substrate. A comparison of these two quantities allows for the rejection of a background of electromagnetically-interacting particles at a level of better than 99.9%. The dominant remaining background at a depth of ~ 11 m below the surface comes from fast neutrons produced by cosmic ray muons interacting in the rock surrounding the experiment. Contamination of our detectors by a beta emitter can add an unknown source of unrejected background. In the energy range of interest for a WIMP study, electrons will have a short penetration depth and preferentially interact near the surface. Some of the ionization signal can be lost to the charge contacts there and a decreased ionization signal relative to the thermal signal will cause a background event which interacts at the surface to be misidentified as a signal event. We can use information about the shape of the thermal signal pulse to discriminate against these surface events. Using a subset of our calibration set which contains a large fraction of electron events, we can characterize the expected behavior of surface events and construct a cut to remove them from our candidate signal events. This thesis describes the development of the 6 detectors (4 x 250 g Ge and 2 x 100 g Si) used in the 2001-2002 CDMS data run at the Stanford Underground Facility with a total of 119 livedays of data. The preliminary results presented are based on the first use 4. Determination of contaminants in nuclear materials by measuring the capture gamma rays of thermal neutrons in a reactor internal geometry International Nuclear Information System (INIS) Suarez, A.A. 1980-01-01 A new method for analysis of impurities in nuclear fuel material was developed. Prompt gamma rays following thermal neutron capture, from a sample placed inside the research reactor were analyzed with a solid state high resolution detector. A number of improvements were introduced to improve the background-to-signal ratio, and the sensitivity of the method: use of collimeters for gamma rays and 6 Li 2 CO 3 filters to eliminate thermal neutrons from the beam were supplemented with the application of a pair spectrometer. Using a 42.5 cm 3 true coaxial Ge(Li) detector, and two optically separated NaI (Tl) scintillation detector, the sensitivity of the method for quantitative determination of impurities reached 30 p.p.m. The reproducibility of the results was better than 2% 5. Combination of gamma radiation and essential oils from medicinal plants in managing Tribolium castaneum contamination of stored products International Nuclear Information System (INIS) Ahmadi, Mehrdad; Abd-alla, Adly Mohamed M.; Moharramipour, Saeid 2013-01-01 Effectiveness of management of insect infestation of stored products with essential oils as viable alternatives to synthetic insecticides can be enhanced with gamma radiation. We studied effects of sublethal doses of essential oils from Rosmarinus officinalis (L.) and Perovskia atriplicifolia (Benth) (safe natural insecticides) in combination with gamma radiation on mortality of adults of Tribolium castaneum (Herbst). The insects were subjected to two radiation doses and two concentrations of the essential oils in the air. This combined treatment increased the mortality, which was also 3–6 times higher than could be expected from the sum of the effects of each of the treatments. The synergistic effect was more pronounced in the case of R. officinalis (L.) than in the case of P. atriplicifolia (Benth). The experiments have shown that the known insecticidal effectiveness of the essential oils can be enhanced by preliminary irradiation. Possible approaches to implementation of the combined treatment are discussed. - Highlights: • The mortality of T. castaneum increased with an increase of the radiation dose. • R. officinalis was more toxic to T. castaneum than P. atriplicifolia. • Gamma radiation and essential oils could be used as combined methods in IPM. • Combination of radiation with essential oils made a synergistic effect. • The synergistic effect of the R–G was much more appropriate from P–G 6. Beta decay of Cu-56 NARCIS (Netherlands) Borcea, R; Aysto, J; Caurier, E; Dendooven, P; Doring, J; Gierlik, M; Gorska, M; Grawe, H; Hellstrom, M; Janas, Z; Jokinen, A; Karny, M; Kirchner, R; La Commara, M; Langanke, K; Martinez-Pinedo, G; Mayet, P; Nieminen, A; Nowacki, F; Penttila, H; Plochocki, A; Rejmund, M; Roeckl, E; Schlegel, C; Schmidt, K; Schwengner, R; Sawicka, M 2001-01-01 The proton-rich isotope Cu-56 was produced at the GSI On-Line Mass Separator by means of the Si-28(S-32, p3n) fusion-evaporation reaction. Its beta -decay properties were studied by detecting beta -delayed gamma rays and protons. A half-Life of 93 +/- 3 ms was determined for Cu-56. Compared to the 7. Microbial Contamination of the Food Materials for Manufacturing Korean Laver Roll (Kimbab) and the Effect of Gamma Irradiation International Nuclear Information System (INIS) Hong, S.P.; Kim, Y.H.; Lee, N.Y.; Jo, C.U.; Byun, M.W. 2004-01-01 Microbial contamination of ready-to-eat ingredients for Kimbab manufacturing and the effect of irradiation to reduce the microbial contamination of the products were investigated. Among 9 food items tested, there were no viable cells in the ham, seasoned and cooked beef, imitation crab leg, fried egg, and seasoned burdoc. Cucumber, surimi gel, and seasoned and blanched spinach were counted at 5.07±0.97, 3.50±0.14, and 5.41±0.51 log CFU/g, respectively 8. Calculation of absorbed dose for skin contamination imparted by beta radiation through the VARSKIN modified code for 122 interesting isotopes for nuclear medicine, nuclear power plants and research; Calculo de dosis absorbida para contaminacion en piel impartida por radiacion beta mediante el codigo VARSKIN modificado para 122 isotopos de interes para medicina nuclear, plantas nucleares e investigacion Energy Technology Data Exchange (ETDEWEB) Alvarez R, J T [Depto. de Metrologia, ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico) 1991-07-01 In this work the implementation of a modification of the VARSKIN code for calculation of absorbed dose for contamination in skin imparted by external radiation fields generated by Beta emitting is presented. The modification consists on the inclusion of 47 isotopes of interest even Nuclear Plants for the dose evaluation in skin generated by 'hot particles'. The approach for to add these isotopes is the correlation parameter F and the average energy of the Beta particle, with relationship to those 75 isotopes of the original code. The methodology of the dose calculation of the VARSKIN code is based on the interpolation, (and integration of the interest geometries: punctual or plane sources), of the distribution functions scaled doses in water for beta and electrons punctual sources, tabulated by Berger. Finally a brief discussion of the results for their interpretation and use with purposes of radiological protection (dose insurance in relation to the considered biological effects) is presented. 9. Development of a tomographic system adapted to 3D measurement of contaminated wounds based on the Cacao concept (Computer aided collimation Gamma Camera) International Nuclear Information System (INIS) Douiri, A. 2002-03-01 The computer aided collimation gamma camera (CACAO in French) is a gamma camera using a collimator with large holes, a supplementary linear scanning motion during the acquisition and a dedicated reconstruction program taking full account of the source depth. The CACAO system was introduced to improve both the sensitivity and the resolution in nuclear medicine. This thesis focuses on the design of a fast and robust reconstruction algorithm in the CACAO project. We start by an overview of tomographic imaging techniques in nuclear medicine. After modelling the physical CACAO system, we present the complete reconstruction program which involves three steps: 1) shift and sum 2) deconvolution and filtering 3) rotation and sum. The deconvolution is the critical step that decreases the signal to noise ratio of the reconstructed images. We propose a regularized multi-channel algorithm to solve the deconvolution problem. We also present a fast algorithm based on Splines functions and preserving the high quality of the reconstructed images for the shift and the rotation steps. Comparisons of simulated reconstructed images in 2D and 3D for the conventional system (CPHC) and CACAO demonstrate the ability of CACAO system to increase the quality of the SPECT images. Finally, this study concludes with an experimental approach with a pixellated detector conceived for a 3D measurement of contaminated wounds. This experimentation proves the possible advantages of coupling the CACAO project with pixellated detectors. Moreover, a variety of applications could fully benefit from the CACAO system, such as low activity imaging, the use of high-energy gamma isotopes and the visualization of deep organs. Moreover the combination of the CACAO system with a pixels detector may open up further possibilities for the future of nuclear medicine. (author) 10. Phoswich Detector for Simultaneous Counting of Alpha- and Beta-ray in a Pipe during Decommissioning International Nuclear Information System (INIS) Seo, B.K.; Kim, G.H.; Woo, Z.H.; Jung, Y.H.; Oh, W.Z.; Lee, K.W.; Han, M.J. 2006-01-01 A great quantity of waste has been generated during the decommissioning of nuclear facilities. These wastes are contaminated with various types of alpha, beta, and gamma nuclides. The contamination level of the decommissioning wastes must be surveyed for free release, but it is very difficult to monitor the radioactive contamination level of the pipe inside using conventional counting methods because of the small diameter. In this study a Phoswich detector for simultaneous counting of alpha- and beta-rays in a pipe was developed. The Phoswich detector is convenient for monitoring of alpha and beta contamination using only a single detector, which was composed of thin cylindrical ZnS(Ag) and plastic scintillator. The scintillator for counting an alpha particle has been applied a cylindrical polymer composite sheet, having a double layer structure of an inorganic scintillator ZnS(Ag) layer adhered onto a polymer sub-layer. The sub-layer in an alpha particle counting sheet is made of polysulfone, working as a mechanical and optical support. The ZnS(Ag) layer is formed by coating a ternary mixture of ZnS(Ag), cyano resin as a binder and solvent onto the top of a sub-layer via the screen printing method. The other layer for counting a beta particle used a commercially available plastic scintillator. The plastic scintillator was simulated by using the Monte Carlo simulation method for detection of beta radiation emitted from internal surfaces of small diameter pipe. Simulation results predicted the optimum thickness and geometry of plastic scintillator at which energy absorption for beta radiation was maximized. Characteristics of the detector fabricated were also estimated. As a result, it was confirmed that detector capability was suitable for counting the beta ray. The overall counting results reveal that the developed Phoswich detector is efficient for simultaneous counting of alpha and beta ray in a pipe. (authors) 11. Overactivation of phospholipase C-gamma1 renders platelet-derived growth factor beta-receptor-expressing cells independent of the phosphatidylinositol 3-kinase pathway for chemotaxis DEFF Research Database (Denmark) Rönnstrand, L; Siegbahn, A; Rorsman, C 1999-01-01 ., Siegbahn, A. , Rorsman, C., Engström, U., Wernstedt, C., Heldin, C.-H., and Rönnstrand, L. (1996) EMBO J. 15, 5299-5313). Here we show that the increased chemotaxis correlates with increased activation of phospholipase C-gamma1 (PLC-gamma1), measured as inositol-1,4, 5-trisphosphate release. By two......-dimensional phosphopeptide mapping, the increase in phosphorylation of PLC-gamma1 was shown not to be selective for any site, rather a general increase in phosphorylation of PLC-gamma1 was seen. Specific inhibitors of protein kinase C, bisindolylmaleimide (GF109203X), and phosphatidylinositol 3-kinase (PI3-kinase), LY294002......, did not affect the activation of PLC-gamma1. To assess whether increased activation of PLC-gamma1 is the cause of the hyperchemotactic behavior of the Y934F mutant cell line, we constructed cell lines expressing either wild-type or a catalytically compromised version of PLC-gamma1 under a tetracycline... 12. Controls of internal contamination from gamma-emitting radionuclides performed whole-body counter measures on children's population from Bjelorussia, Russia and Ucraina International Nuclear Information System (INIS) Tarroni, G.; Battisti, P.; Castellani, C.M.; Formignani, M.; Rampa, E.; Ticconi, R. 1994-12-01 This report summarizes the results obtained in 9 measurement campaigns, performed at the ENEA (Italian Agency for New Technologies, Energy and the Environment) centres of Bologna and Roma-Casaccia from April 1991 to September 1992, for the assessment of internal contamination from gamma-emitting radionuclides. Homogeneous samples were selected for the controls, each one representing the children's population from given area. 15 areas were investigated and 24 examined; 20 of them were from Bjelorussia. 266 children, 124 male and 142 female subjects, were controlled. The instruments were intercalibrated according to the body size, from 20.25 kg to 81 kg. Body contamination only from 1 37 Cs and 1 34 Cs was detected. Evaluations were performed in order to test appropriate use of ICRP caesium biokynetic model for children aged 8 to 15 years. Statistical distribution of body activity data were carefully analyzed. It is demonstrated that the data are well fitted by lognormal distribution and a difference between sexes in terms of activity. A significant difference between sexes was found in terms of activity intake 13. Effect of gamma radiation as a method of storing brown flaxseed after 6 months of storage, inhibiting contamination by aflatoxigenic fungi Energy Technology Data Exchange (ETDEWEB) Costa, Laury Francis; Silva, Edvane Borges da Silva, E-mail: lauryfrancis@gmail.com, E-mail: edvborges@yahoo.com [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear; Oliveira, Idjane Santana, E-mail: idjaneoliveira@gmail.com [Universidade Federal de Pernambuco (CAV/UFPE), Vitoria de Santo Antao, PE (Brazil). Centro Academico de Vitoria 2013-07-01 Flaxseed is an oilseed rich in proteins, lipids and dietary fiber. The brown flaxseed is grown in warm climates and humid, like Brazil, and has shelled tougher than the golden linseed. As the tropical climate is ideal environment for the growth of toxigenic fungi, flaxseed may be exposed to contamination. Four different samples of brown flaxseed were collected in sealed packages obtained from health food stores. Aliquots of grains were separated, packed with PVC film, identified according to the company (E1, E2, E3, E4) and subjected to the process of gamma irradiation doses: 2.5, 5.0, 7.5 and 10 kGy, beyond the control sample that was not exposed. This material was stored in a cool dry place in the laboratory for six months. After that time, the grains were sown in DRBC, to check the growth of total fungi, and in AFPA, to check the growth of aflatoxigenic fungi. After sowing grains, the Petri dishes were randomly distributed on the bench, at room temperature. There was no growth of aflatoxigenic fungi in irradiated samples after incubation, demonstrating that radiation could inhibit fungal contamination during the storage time. Germinated grains were observed in both culture media, in all doses and in the control samples. The germination of flaxseed was inversely proportional to the dose applied to the grains, to both culture media. Irradiation showed to be an effective method for brown flaxseed conservation and maintaining the germination. (author) 14. Microbial contamination of red meat and consideration of gamma irradiation effects for increasing the shelf-life and decontamination of pathogenic microorganisms International Nuclear Information System (INIS) Motamedee Sadeh, F.; Majd, F.; Fathollahee, H.; Arbabi, K.; Mohammad Beygi Abhari, M. 2003-01-01 Red meat has a lot of microbial flora from different sources. Prevention of outbreak of food born diseases that are caused by pathogenic agents and prevention of microbial spoilage of meat that makes many losses to the human health and economic of society are very important. Also, different methods for decreasing the microbial flora under a standard allowance for increasing the shelf life and decontamination of microbial pathogens have been proposed. In this research, irradiation technique was used for this purposes. After drawing dose/survival curves for all kinds of meats microbial contamination, an optimum dose of 3 kGy for decreasing the contamination and specially for decontamination of salmonella was obtained. When meat is irradiated by 3 kGy gamma rays, it can be kept in a 4-7 d ig C refrigerator for 2 week without appearing any spoilage nor color changes or odor. Also, some of biochemical factors were analyzed and amounts of 16 amino acids were measured in the irradiated and controlled samples and no difference was observed between the samples 15. Use of a nanoplanktonic alga as a test organism in marine molysmology. Some responses of Dunaliella Bioculata Butcher 1959 to gamma irradiation and to chromium and cadmium contamination International Nuclear Information System (INIS) Peneda-Saraiva, M.C. 1975-01-01 Some response of a nanoplanktonic alga, Dunaliella bioculata to gamma irradiation ( 60 Co) and to heavy metal contamination, (chromium and cadmium) used either at strong concentrations (stable isotopes) or as tracers ( 51 Cr) and ( 109 Cd) were studied. The average variation of several biological functions under the effect of these agents was followed: mitotic activity, culture development, cell volume, chlorophyll a and protein concentrations per cell per unit volume (μm 3 ), respiratory and photosynthetic activities, ultrastructure or cytological aspect of the algae. Concentration factors were investigated in cases of contamination. The method used include standard digital counting with a Thoma cell or a particle counter coupled to an amplitude analyser, volume estimation using the hematocrit, pigment determination by acetone extraction, protein determination by the Nessler method. The polarographic method of dissolved oxygen measurement was adapted for successive respiration and photosynthesis experiments on the material concerned. Any Cr and Cd incorporated by Dunaliella bioculata were determined after splitting of the cells and separation of the membranes from the cell contents. The quantity of metal present was measured on each fraction by atomic absorption spectrophotometry [fr 16. Effect of gamma radiation as a method of storing brown flaxseed after 6 months of storage, inhibiting contamination by aflatoxigenic fungi International Nuclear Information System (INIS) Costa, Laury Francis; Silva, Edvane Borges da Silva; Oliveira, Idjane Santana 2013-01-01 Flaxseed is an oilseed rich in proteins, lipids and dietary fiber. The brown flaxseed is grown in warm climates and humid, like Brazil, and has shelled tougher than the golden linseed. As the tropical climate is ideal environment for the growth of toxigenic fungi, flaxseed may be exposed to contamination. Four different samples of brown flaxseed were collected in sealed packages obtained from health food stores. Aliquots of grains were separated, packed with PVC film, identified according to the company (E1, E2, E3, E4) and subjected to the process of gamma irradiation doses: 2.5, 5.0, 7.5 and 10 kGy, beyond the control sample that was not exposed. This material was stored in a cool dry place in the laboratory for six months. After that time, the grains were sown in DRBC, to check the growth of total fungi, and in AFPA, to check the growth of aflatoxigenic fungi. After sowing grains, the Petri dishes were randomly distributed on the bench, at room temperature. There was no growth of aflatoxigenic fungi in irradiated samples after incubation, demonstrating that radiation could inhibit fungal contamination during the storage time. Germinated grains were observed in both culture media, in all doses and in the control samples. The germination of flaxseed was inversely proportional to the dose applied to the grains, to both culture media. Irradiation showed to be an effective method for brown flaxseed conservation and maintaining the germination. (author) 17. Plutonium contaminated materials research programme. Progress Report for 1983/84 from the Plutonium Contaminated Materials Working Party International Nuclear Information System (INIS) Higson, S.G. 1984-01-01 Plutonium contaminated material (PCM) is a generic term applied to a wide variety of materials which have become contaminated by plutonium compounds, by virtue of their use inside the primary containment of fuel cycle plants, but which generally have low beta gamma content. The report falls under the headings: introduction; organisation and role of the PCMWP; management practices; 1983/84 progress report (a) reduction of arisings; (b) plutonium measurement; (c) treatment of solid PCM; (d) treatment of alpha bearing liquid wastes; (e) actinide chemistry; (f) engineering objectives. (U.K.) 18. Annihilation gamma ray background characterization and rejection for a positron camera International Nuclear Information System (INIS) Levin, C.S.; Tornai, M.P.; MacDonald, L.R. 1996-01-01 We have developed a miniature (1.2 cm 2 ) beta-ray camera prototype to assist a surgeon in locating and removing the margins of a resected tumor. When imaging positron emitting radiopharmaceuticals, annihilation gamma ray interactions in the detector can mimic those of the betas. The extent of the background contamination depends on the detector, geometry and tumor specificity of the radiopharmaceutical. We have characterized the effects that annihilation gamma rays have on positron imaging with the camera. We studied beta and gamma ray detection rates and imaging using small positron or electron sources directly exposed to the detector to simulate hot tumor remnants and a cylinder filled with 18 F to simulate annihilation background from the brain. For various ratios of phantom brain/tumor activity, a annihilation gamma rate of 1.8 cts/sec/gCi was measured in the CaF 2 (Eu) detector. We present two gamma-ray background rejection schemes that use a β-γ coincidence. Results show that the coincidence methods works with ∼99% gamma ray rejection efficiency 19. Treatment techniques for the removal of radioactive contaminants from drinking water International Nuclear Information System (INIS) Logsdon, Gary S. 1978-01-01 Maximum contaminant levels have been set for radioactive contaminants, as required by the Safe Drinking Water Act (PL 93-523). Treatment techniques are available for removing radium and beta-gamma emitters. Presently-used methods of removing radium-226 are precipitative lime softening (80-90% removal) ion exchange softening (95% removal) and reverse osmosis (95% removal). The 5 p Ci/l limit for radium can be met with conventional technology for raw waters in the 5-100 p Ci/l concentration range. Treatment for removal of beta or gamma emitters must be based upon chemical rather than radioactive characteristics of the contaminant. Reverse osmosis can remove a broad spectrum of ions and molecules from water, so it is the process most likely to be used. The maximum contaminant level for beta and gamma radioactivity is an annual dose equivalent to the total body or any organ not to exceed 4 m rem/year. The fate of radionuclides after removal from drinking water should be considered. Presently radium is disposed with other process wastes at softening plants removing radium. Confinement and disposal as a radioactive waste would be very expensive. (author) 20. Studying the application of gamma radiation in removing fungal contamination of poultry grain and the effect of this radiation on changing the immunity titer related to vaccinate SPF chickens International Nuclear Information System (INIS) Shahhoseini, Gh. R. 1998-01-01 Considering the existing problems in discarding or reducing the fungal contamination of poultry grain, due to the conventional methods being inadequate, for example remainder of fungal toxins (using chemical substance) or grain's dampness (using autoclave) etc, make us using nuclear techniques to remove these problems. First specification and determination of contamination types and also determination types and also determination of different kinds of fungal contamination and their amount in the poultry grain was done. The most fungal contamination were Aspergillus in the starter grain. Then biochemical analysis in poultry grain and determination of existence and the amount of Aflatoxin was done. Then gamma radiation of Co-60 from 1 to 6 kilo grays doses were applied in order to reduce or remove the contamination and finally 6 kilo gray dose was chosen. Rechecking the irradiated grains 4-5 months after application of gamma radiation in different moisture and temperatures (in cellophane packaging) revealed 6 kilo gray dose not only has constant effect in removal of fungal contamination and Aflatoxin (in the two cases) but also has no negative effect on the grain's compounds. In the continuation of this research two types of grain: non-irradiated and irradiated were fed to identical groups of SPF chickens in three different time periods. The follow up experiments showed the immune titers in the chickens fed on the irradiated grain were lower than the immune titers in the chickens fed on the non-irradiated grain. (author) 1. Adaptation and impairment of DNA repair function in pollen of Betula verrucosa and seeds of Oenothera biennis from differently radionuclide-contaminated sites of Chernobyl. Science.gov (United States) Boubriak, I I; Grodzinsky, D M; Polischuk, V P; Naumenko, V D; Gushcha, N P; Micheev, A N; McCready, S J; Osborne, D J 2008-01-01 The plants that have remained in the contaminated areas around Chernobyl since 1986 encapsulate the effects of radiation. Such plants are chronically exposed to radionuclides that they have accumulated internally as well as to alpha-, beta- and gamma-emitting radionuclides from external sources and from the soil. This radiation leads to genetic damage that can be countered by DNA repair systems. The objective of this study is to follow DNA repair and adaptation in haploid cells (birch pollen) and diploid cells (seed embryos of the evening primrose) from plants that have been growing in situ in different radionuclide fall-out sites in monitored regions surrounding the Chernobyl explosion of 1986. Radionuclide levels in soil were detected using gamma-spectroscopy and radiochemistry. DNA repair assays included measurement of unscheduled DNA synthesis, electrophoretic determination of single-strand DNA breaks and image analysis of rDNA repeats after repair intervals. Nucleosome levels were established using an ELISA kit. Birch pollen collected in 1987 failed to perform unscheduled DNA synthesis, but pollen at gamma/beta-emitter sites has now recovered this ability. At a site with high levels of combined alpha- and gamma/beta-emitters, pollen still exhibits hidden damage, as shown by reduced unscheduled DNA synthesis and failure to repair lesions in rDNA repeats properly. Evening primrose seed embryos generated on plants at the same gamma/beta-emitter sites now show an improved DNA repair capacity and ability to germinate under abiotic stresses (salinity and accelerated ageing). Again those from combined alpha- and gamma/beta-contaminated site do not show this improvement. Chronic irradiation at gamma/beta-emitter sites has provided opportunities for plant cells (both pollen and embryo cells) to adapt to ionizing irradiation and other environmental stresses. This may be explained by facilitation of DNA repair function. 2. Monitoring of the internal contamination of occupationally exposure personnel in services of nuclear medicine through the use of gamma cameras International Nuclear Information System (INIS) Teran, M.; Paolino, A.; Savio, E.; Hermida, J.C.; Dantas, B.M. 2006-01-01 The radionuclides incorporation can happen as a result of diverse activities; these include the work associated with the different stadiums of the nuclear fuel cycle, the use of radioactive sources in medicine, the scientific research, the agriculture and the industry. In Uruguay the main activities linked to the manipulation of open sources correspond those of Nuclear Medicine and from 2004, in the mark of the Project Arcal RLA 049 and being based on the Safety Guides of the IAEA it is implementing a program of internal monitoring in combined form the Nuclear Medicine Center of the Hospital of and the Radiochemistry class of the Faculty of Chemistry. In accordance with the publication of the ICRP 75 the emphasis of any monitoring program should be in the formal study of the doses in the workers to who are considered commendable of to receive in routine form an outstanding fraction of the dose limits or who work in areas where the exposures can be significant in the accident event. From April 2004, to the date has started a pilot plan by means of in that were established appropriate conditions of procedures and of safety in a reduced group of workers of the Nuclear Medicine area. In that period the first work limits, equipment adjustment, calibrations and registration systems were determined. The monitoring system implemented until the moment is carried out with a thyroid caption equipment. However these measurements are carried out in the university hospital embracing 40% of the involved workers of our country, with the purpose of reaching the covering of the biggest quantity of occupationally exposed personnel of private clinics. Also it was developed a new work proposal that allows to have an alternative measure method, in the event of not having the equipment habitually used. Among the conclusions of this work are that for the before exposed are considered the measure conditions but appropriate the following ones: Gamma Camera without collimator; Measurement 3. Intercomparison measurements of surface soil contamination with in-situ gamma ray spectrometry. Pt.1. Artificial radionuclides International Nuclear Information System (INIS) Winkelmann, I. 1994-01-01 This intercomparison program was performed by the Federal Office of Radiation Protection in October 1993. It includes seven laboratory teams from five countries and is applied on a pasture in southern Germany having an undisturbed soil profile. The location was chosen because of its relatively high 137 Cs-soil contamination caused by the Chernobyl accident - up to 50 kBq/m 2 . The deposition of 134 Cs and 137 Cs was determined. The comparison demonstrated a good agreement between results from different labs. Additionally, the dose rate at all marked locations was measured and compared to the dose rate of individual radionuclides calculated from the measured spectra. A relatively good agreement was obtained. It is shown that the main contribution to the total dose rate of 70 nSv/h is made by 137 Cs with a value of 5 nSv/h. 4 figs., 2 tabs., 3 refs. (orig.) 4. Soil contaminated phyto remediation of Pb and cd metal by using rice straw fermented by trichoderma viride that given exposure 250 gray doses of gamma radiation International Nuclear Information System (INIS) Yullita SL Andini; Hendrawati; Tri Retno Diah Larasati; Nana Mulyana 2015-01-01 Soil contamination by lead (Pb) and cadmium (Cd) is one form of environmental pollution that is harmful to living organisms. One way to resolve this problem by using phyto remediation with rice straw fermented by Trichoderma viride that given exposure 250 gray doses of gamma radiation. The purpose of this study was to look at the effect of Trichoderma viride fermented hay to improve the ability of Pb and Cd accumulation in the root zone of plants sweet corn (Zea Mays). There are three stages in the research process, namely the stages of SSF (Solid State Fermentation), incorporation, and Land farming. The fermentation process is done during the 16-day trial. Furthermore, the results of the SSF (Solid State Fermentation) mixed in soil that has been contaminated with heavy metals showed that administration of straw result SSF real impact on the value of pH, water content of the four treated samples. Results incorporation process and then applied with a crop of sweet corn (Zea Mays). Accumulation of heavy metals in sweet corn plant, analyzed by AAS analysis instrumentation. The measurement results show that the accumulation of Pb in the roots of plants in the sample K amounted to 33.66 mg/Kg, A sample of 26.80 mg/Kg, the sample B of 51.47 mg/kg, and sample C of 55.70 mg/Kg. While the metals Cd uptake in the roots of corn plants in the sample K showed Cd uptake of 269.65 mg/Kg, the sample A of 445.70 mg/Kg, the sample B of 337.17 mg/Kg and sample C of 336.72 mg/Kg. The phyto remediation process takes place based on the fito-stabilization principle. (author) 5. Beta-energy averaging and beta spectra International Nuclear Information System (INIS) Stamatelatos, M.G.; England, T.R. 1976-07-01 A simple yet highly accurate method for approximately calculating spectrum-averaged beta energies and beta spectra for radioactive nuclei is presented. This method should prove useful for users who wish to obtain accurate answers without complicated calculations of Fermi functions, complex gamma functions, and time-consuming numerical integrations as required by the more exact theoretical expressions. Therefore, this method should be a good time-saving alternative for investigators who need to make calculations involving large numbers of nuclei (e.g., fission products) as well as for occasional users interested in restricted number of nuclides. The average beta-energy values calculated by this method differ from those calculated by ''exact'' methods by no more than 1 percent for nuclides with atomic numbers in the 20 to 100 range and which emit betas of energies up to approximately 8 MeV. These include all fission products and the actinides. The beta-energy spectra calculated by the present method are also of the same quality 6. Calculation of the absorbed dose for contamination in skin imparted by beta radiation through the Varskin code modified for 122 isotopes of interest for nuclear medicine, nuclear plants and research International Nuclear Information System (INIS) Alvarez R, J.T. 1992-06-01 In this work the implementation of a modification of the Varskin code for calculation of absorbed dose by contamination in skin imparted by external radiation fields generated by beta emitting is presented. The necessary data for the execution of the code are: isotope, dose depth, isotope activity, geometry type, source radio and time of integration of the isotope, being able to execute combinations of up to five radionuclides. This program it was implemented in Fortran 5 by means of the FFSKIN source program and the executable one in binary language BFFSKIN being the maximum execution time of 5 minutes. (Author) 7. Exploitation of the FLK-60 slagging incinerator for different alpha waste streams and study of the feasibility of medium-level alpha-beta-gamma waste incineration in FLK-60 International Nuclear Information System (INIS) Van de Voorde, N.; Taeymans, A.; Hennart, D.; Balleux, W.; Geenen, G.; Gijbels, J. 1985-01-01 The FLK-60 high temperature slagging incinerator and its peripherals were developed by SCK/CEN with the help of the Commission of the European Communities in the framework of contract no. EUR-017-76-7 WAS-B. This second contract, which covered the period between October 1980 and December 1982, aimed at gaining exploitation experience by running the FLK-60 installation with beta-gamma radioactive waste in semi-industrial conditions. At the end of those 27 months, the system was ready for exploitation in alpha-conditions with plutonium-containing materials. This report describes the various plant parameters during the 25 runs carried out in the framework of this contract and the results of characterization tests carried out on the final product and the secondary waste streams. In the meantime, typical operation balances are computed 8. Beta and gamma decay heat measurements between 0.1s--50,000s for neutron fission of 235U, 238U and 239Pu. Final report, June 1, 1992--December 31, 1996 International Nuclear Information System (INIS) Schier, W.A.; Couchell, G.P. 1996-01-01 This is a final reporting on the composition of separate beta and gamma decay heat measurements following neutron fission of 235 U and 238 U and 239 Pu and on cumulative and independent yield measurements of fission products of 235 U and 238 U. What made these studies unique was the very short time of 0.1 s after fission that could be achieved by incorporating the helium jet and tape transport system as the technique for transporting fission fragments from the neutron environment of the fission chamber to the low-background environment of the counting area. This capability allowed for the first time decay heat measurements to extend nearly two decades lower on the logarithmic delay time scale, a region where no comprehensive aggregate decay heat measurements had extended to. This short delay time capability also allowed the measurement of individual fission products with half lives as short as 0.2s. The purpose of such studies was to provide tests both at the aggregate level and at the individual nuclide level of the nation's evaluated nuclear data file associated with fission, ENDF/B-VI. The results of these tests are in general quite encouraging indicating this data base generally predicts correctly the aggregate beta and aggregate gamma decay heat as a function of delay time for 235 U, 238 U and 239 Pu. Agreement with the measured individual nuclide cumulative and independent yields for fission products of 235 U and 238 U was also quite good although the present measurements suggest needed improvements in several individual cases 9. Microbial contamination of the crude drugs ''Senna Leaf'' and their radiation sensitivity to gamma-ray irradiation International Nuclear Information System (INIS) Ohnishi, Tokuhiro; Okamoto, Shinichi; Taimatsu, Meiko; Kimura, Syojiro 1998-01-01 The numbers of microorganisms adhering to the crude drug ''Senna Leaf'' and radiation sensitivity of them were investigated. Total aetobic microbial counts of ten kinds of Senna Leaf were determined to be in the range from 10 3 to 10 4 CFU/g for bacteria and from 10 1 to 10 3 CFU/g for fungi. The orders of these values were higher than the synthetic compound. Most of survival curves obtained in this experiment were sigmoidal. The induction dose (ID) was obtained from the shoulder portion of each curve, the D 2 value was obtained from the gradient of the linear portion of each curve and the inactivation factor (IF) was calculated from the sigmoid curve. The average values of ID, D 2 and IF for bacteria were 2.9 kGy, 1.0 kGy and 8.1 kGy respectively. From this experiment, the average SD value required for attaining the contamination level provided by the USP Forum (total bacteria count <20/g) was estimated to be 6 kGy. The numbers of fungi becomes less than 10 CFU/g under this condition. (author) 10. Calculation of the absorbed dose for contamination in skin imparted by beta radiation through the Varskin code modified for 122 isotopes of interest for nuclear medicine, nuclear plants and research; Calculo de dosis absorbida para contaminacion en piel impartida por radiacion beta mediante el codigo Varskin modificado para 122 isotopos de interes para medicina nuclear, plantas nucleares e investigacion Energy Technology Data Exchange (ETDEWEB) Alvarez R, J T 1992-06-15 In this work the implementation of a modification of the Varskin code for calculation of absorbed dose by contamination in skin imparted by external radiation fields generated by beta emitting is presented. The necessary data for the execution of the code are: isotope, dose depth, isotope activity, geometry type, source radio and time of integration of the isotope, being able to execute combinations of up to five radionuclides. This program it was implemented in Fortran 5 by means of the FFSKIN source program and the executable one in binary language BFFSKIN being the maximum execution time of 5 minutes. (Author) 11. Prolixe-prototype reprocessing unit for irradiating wastes contamined with alpha emitters International Nuclear Information System (INIS) Madic, C.; Sontag, R. 1987-01-01 A large number of hot cells are employed for research on nuclear fuel reprocessing and the production of isotope of transuranium elements. These activities generate solid wastes highly contaminated with alpha, beta, gamma emitters. The Prolixe hot cell was built in order to: 1/ reprocess the solid wastes contaminated with alpha, beta, gamma emitters produced in the Radiochemistry building: 2/ produce package wastes storable in shallow-ground disposal sites: 3/ develop a process sufficiently flexible to make it applicable to waste produced in other installations. The process is based on waste leaching after grinding. Depending on the type of wastes the leaching reactant will have a different composition 1/ nitric acid solution for cellulose waste: 2/ nitric solutions containing Ag(II) for other material. The complete process should achieve: 1/ a high waste volume reduction factor: 2/ the production of immobilized waste packages storage in shallow-ground disposal sites: 3/ the recycling of transuranium elements: 4/ the generation of a minimal volume of effluents. This process can be considered as an alternative process to incineration for the reprocessing of solid wastes highly contaminated with alpha, beta, gamma emitters 12. Beta decay of 22O International Nuclear Information System (INIS) Hubert, F.; Dufour, J.P.; Moral, R. del; Fleury, A.; Jean, D.; Pravikoff, M.S.; Delagrange, H.; Geissel, H.; Schmidt, K.H.; Hanelt, E. 1989-01-01 The beta-gamma spectroscopic study of 22 O is presented. This nucleus, produced as a projectile-like fragment from the interaction of a 60 MeV/n 40 Ar beam with a Be target, has been separated by the LISE spectrometer. Several gamma rays from 22 O decay have been observed, from which a half-life of (2.25±0.15) s has been determined. Accurate excitation energies have been deduced for several states in 22 F. A partial beta decay scheme of 22 O has been established. Experimental results have been compared with shell model calculations. (orig.) 13. Calibration of thermoluminescence skin dosemeter response to beta emitters found in Ontario Hydro nuclear power stations International Nuclear Information System (INIS) Walsh, M.L.; Agnew, D.A.; Donnelly, K.E. 1984-01-01 The response of the Ontario Hydro Thermoluminescence Dosimetry System to beta radiation in nuclear power station environments was evaluated. Synthetic beta spectra were constructed, based on activity samples from heat transport systems and fuelling machine contamination smears at nuclear power stations. Using these spectra and dosemeter energy response functions, an overall response factor for the skin dosemeter relative to skin dose at 7 mg.cm -2 was calculated. This calculation was done assuming three specific geometries: (1) an infinite uniformly contaminated plane source at a distance of 33 cm (50 mg.cm -2 total shielding) from the receptor; (2) an infinite cloud surrounding the receptor; (3) a point source at 33 cm. Based on these calculations, a conservative response factor of 0.7 has been chosen. This provides an equation for skin dose assignment, i.e. Skin Dose = 1.4 x Skin Dosemeter Reading when the skin dosemeter is directly calibrated in mGy(gamma). (author) 14. Comparison of the analytical methods used to determine natural and artificial radionuclides from environmental samples by gamma, alpha and beta spectrometry DEFF Research Database (Denmark) Pöllänen, Roy; Virtanen, Sinikka; Kämäräinen, Meerit In CAMNAR, an extensive interlaboratory exercise on the analytical methods used to determine several radionuclides present in the environmental samples was organized. Activity concentration of different natural radionuclides, such as Rn-222, Pb-210, Po-210, K-40, Ra-226, Ra-228 and isotopes...... of uranium, in addition to artificial Cs-137 and Am-241 were analysed from lake sediment samples and drinking water. The measurement techniques were gamma-ray spectrometry, alpha spectrometry, liquid scintillation counting and inductively coupled plasma mass spectrometry. Twenty six laboratories from nine... 15. Studies of the\\beta$-decay of Sr nuclei on and near the N=Z Line with a Total Absorption Gamma-ray Spectrometer CERN Multimedia Marechal, F; Caballero ontanaya, L 2002-01-01 In the framework of the investigation of the shapes of the ground states of the parent nucleus, we propose to carry out measurements of the complete Gamow-Teller strength distribution for the$^{76-80}$Sr isotopes, with a new Total Absorption Gamma Spectrometer installed on a new beam line. The results will be compared with theoretical calculations based on the mean field approach. A brief report on the IS370 experiment on$^{72-75}$Kr decay, which was recently performed at ISOLDE, will be given and the performance of the sum spectrometer will be presented. 16. Instrument evaluation no. 18. Mini instruments contamination meter type 5.10 EL International Nuclear Information System (INIS) Burgess, P.H.; Iles, W.J. 1980-04-01 An evaluation is given of the general purpose contamination monitor, the Mini-Instruments Type 5-10EL which comprises a probe connected by a coiled extensible cable to a ratemeter. The facilities and controls, radiation characteristics, electrical characteristics, environmental effects, mechanical characteristics, and the manual are considered. A summary is given of the instrument's performance showing that it is a useful general-purpose contamination monitor suitable for the monitoring of beta contamination at a level for non-active areas of 1 DL (3.7 Bq cm -2 (10 -4 μCi cm -2 )) for beta emitters of maximum energy at least that of 14 C, given a normal environmental gamma background. (U.K.) 17. Expression of human gamma-globin genes in human erythroleukemia (K562) cells. Science.gov (United States) Donovan-Peluso, M; Acuto, S; Swanson, M; Dobkin, C; Bank, A 1987-12-15 K562 cells express embryonic (epsilon) and fetal (gamma) globins and hemoglobins but not adult (beta) globin. To define the cis acting regulatory elements involved in the discrimination between gamma and beta genes, we have constructed chimeric genes composed of portions of gamma and beta and evaluated their expression in stable K562 transfectants. A gamma beta fusion gene containing gamma 5' sequences to the EcoRI site in exon 3 and beta sequences 3' is expressed at 10-40% that of the endogenous gamma level. In 50% of the lines, this fusion gene appropriately increases its expression in response to hemin, an inducer of endogenous globin gene expression in K562 cells. In contrast, a beta gamma fusion gene, containing beta sequences 5' to the EcoRI site in exon 3 and gamma sequences 3', is neither expressed nor correctly initiated. A beta gene containing gamma-intervening sequence (IVS) 2 accumulates an mRNA transcript when analyzed with a 3' beta probe. However, no correctly initiated beta mRNA is observed. A gamma gene with beta-IVS 2 is only inducible in one of six expressing clones. All the results are consistent with the presence of stage-specific trans acting factors in K562 cells that stimulate expression of gamma genes and suggest a significant role for gamma-IVS 2 in gamma gene expression. 18. Speculative Betas OpenAIRE Harrison Hong; David Sraer 2012-01-01 We provide a model for why high beta assets are more prone to speculative overpricing than low beta ones. When investors disagree about the common factor of cash-flows, high beta assets are more sensitive to this macro-disagreement and experience a greater divergence-of-opinion about their payoffs. Short-sales constraints for some investors such as retail mutual funds result in high beta assets being over-priced. When aggregate disagreement is low, expected return increases with beta due to r... 19. Effect of gamma-irradiation on the levels of total and cis/trans isomers of beta-carotene in dehydrated parsley Science.gov (United States) Sebastião, Kátia I.; Almeida-Muradian, Lígia B.; Romanelli, Maria Fernanda; Koseki, Paula Massae; Villavicencio, Anna Lúcia C. H. 2002-03-01 Ionizing radiation is a method for preservation of foods that use the high energy of gamma rays or accelerated electrons, thereby ionizing molecules. The most important precursor of vitamin A is β-carotene, a carotenoid with pro-vitamin A activity. The highly unsaturated chain confers the instability of β-carotene, and some reactions, as isomerisation, can reduce the characteristics of pro-vitamin A. The present study investigated whether increasing doses of 0, 10 and 20 kGy lower the total β-carotene level and if an enhancement of cis-isomers occurred on samples of dehydrated parsley. No differences were observed of either fractions analyzed at doses applied in this study, nor did it contribute to the decrease of vitamin A. 20. Effect of gamma-irradiation on the levels of total and cis/trans isomers of beta-carotene in dehydrated parsley International Nuclear Information System (INIS) Sebastiao, K.I.; Almeida-Muradian, L.B.; Romanelli, Maria Fernanda; Koseki, Paula Massae; Villavicencio, A.L.C.H. 2002-01-01 Ionizing radiation is a method for preservation of foods that use the high energy of gamma rays or accelerated electrons, thereby ionizing molecules. The most important precursor of vitamin A is β-carotene, a carotenoid with pro-vitamin A activity. The highly unsaturated chain confers the instability of β-carotene, and some reactions, as isomerisation, can reduce the characteristics of pro-vitamin A. The present study investigated whether increasing doses of 0, 10 and 20 kGy lower the total β-carotene level and if an enhancement of cis-isomers occurred on samples of dehydrated parsley. No differences were observed of either fractions analyzed at doses applied in this study, nor did it contribute to the decrease of vitamin A 1. Inhibition of [gamma]-endorphin generating endopeptidase activity of rat brain by peptides: Structure activity relationship NARCIS (Netherlands) Lebouille, J.L.M.; Visser, W.H.; Hendriks, R.W.; Nispen, J.W. van; Greven, H.M.; Burbach, J.P.H. 1985-01-01 Gamma-Endorphin generating endopeptidase (gammaEGE) activity is an enzyme activity which converts beta-endorphin into gamma-endorphin and beta-endorphin-(18–31). The inhibitory potency on gammaEGE activity of neuropeptides and analogues or fragments of neuropeptides was tested. Dynorphin-(1–13) 2. High temperature slagging incinerator for alpha contaminated wastes International Nuclear Information System (INIS) Van de Voorde, N. 1985-01-01 This report describes the experiences collected by the treatment of plutonium-contaminated wastes, in the High Temperature Slagging Incinerator at the C.E.N./S.C.K. at Mol, with the support of the Commission of the European Communities. The major objective of the exercise is to demonstrate the operability of this facility for the treatment of mixed transuranic (TRU) and beta-gamma solid waste material. The process will substantially reduce the TRU waste volume by burning the combustibles and converting the non-combustibles into a chemically inert and physically stable basalt-like slag product, suitable for safe transport and final disposal. (Auth.) 3. Study of the N=28 shell closure by one neutron transfer reaction: astrophysical application and {beta}-{gamma} spectroscopy of neutron rich nuclei around N=32/34 and N=40; Etude de la fermeture de couche N=28 autour du noyau {sub 18}{sup 46}Ar{sub 28} par reaction de transfert d'un neutron: application a l'astrophysique et Spectroscopie {beta}-{gamma} de noyaux riches en neutrons de N=32/34 et N=40 Energy Technology Data Exchange (ETDEWEB) Gaudefroy, L 2005-09-15 The study of the N=28 shell closure has been presented as well as its astrophysical implications. Moreover the structure of neutron rich nuclei around N=32/34 and 40 was studied. The N=28 shell closure has been studied trough the one neutron transfer reaction on {sup 44,46}Ar nuclei. Excitation energies of states in {sup 45,47}Ar nuclei have been obtained, as well as their angular momenta and spectroscopic factors. These results were used to show that N=28 is still a good magic number in the argon isotopic chain. We interpreted the evolution of the spin-orbit partner gaps in terms of the tensor monopolar proton-neutron interaction. Thanks to this latter, we showed it is not necessary to summon up a reduction of the intensity of the spin-orbit force in order to explain this evolution in N=29 isotopes from calcium to argon chains. The neutron capture rates on {sup 44,46}Ar have been determined thanks to the results of the transfer reaction. Their influence on the nucleosynthesis of {sup 46,48}Ca was studied. We proposed stellar conditions to account for the abnormal isotopic ratio observed in the Allende meteorite concerning {sup 46,48}Ca isotopes. The beta decay and gamma spectroscopy of neutron rich nuclei in the scandium to cobalt region has been studied. We showed that beta decay process is dominated by the {nu}f{sub 5/2} {yields} {pi}f{sub 7/2} Gamow-Teller transition. Moreover, we demonstrated that the {nu}g{sub 9/2} hinders this process in the studied nuclei, and influences their structure, by implying the existence of isomers. Our results show that N=34 is not a magic number in the titanium chain and the superior ones. (author) 4. 16 alpha-[77Br]bromoestradiol-17 beta: a high specific-activity, gamma-emitting tracer with uptake in rat uterus and uterus and induced mammary tumors International Nuclear Information System (INIS) Katzenellenbogen, J.A.; Senderoff, S.G.; McElvany, K.D.; O'Brien, H.A. Jr.; Welch, M.J. 1981-01-01 16 alpha-[77Br]bromoestradiol-17 beta (Compound 1) has been synthesized by radiobromination of estrone enoldiacetate. Tissue uptake studies performed 1 h after administration of Compound 1 to immature or mature female rats showed uterus-to-blood ratios of 13, with nontarget issue-to-blood ratios ranging from 0.6 to 2. Co-administration of unlabelled estradiol caused a selective depression in the uterine uptake with no effect on nontarget tissue uptake. In adult animals bearing adenocarcinomas induced by DMBA (7,12-dimethylbenz(a)anthracene), tumor-to-blood ratios of 6.3 were obtained, this uptake also being depressed in animals treated with unlabeled estradiol. The studies demonstrate that Compound 1 has suitable binding properties and sufficiently high specific activity so that its uptake in estrogen target tissues in vivo is mediated primarily by the estrogen receptor. Furthermore, they suggest that this compound may be suitable for imaging human breast tumors that contain estrogen receptors 5. Curcumin attenuates beta-amyloid-induced neuroinflammation via activation of peroxisome proliferator-activated receptor-gamma function in a rat model of Alzheimer’s disease Directory of Open Access Journals (Sweden) Zun-Jing Liu 2016-08-01 Full Text Available Neuroinflammation is known to have a pivotal role in the pathogenesis of Alzheimer’s disease (AD, and curcumin has been reported to have therapeutical effects on AD because of its anti-inflammatory effects. Curcumin is not only a potent PPARγ agonist, but also has neuroprotective effects on cerebral ischemic injury. However, whether PPARγ activated by curcumin is responsible for the anti-neuroinflammation and neuroprotection on AD remains unclear, and needs to be further investigated. Here, using both APP/PS1 transgenic mice and beta-amyloid-induced neuroinflammation in mixed neuronal/glial cultures, we showed that curcumin significantly alleviated spatial memory deficits in APP/PS1 mice and promoted cholinergic neuronal function in vivo and in vitro. Curcumin also reduced the activation of microglia and astrocytes, as well as cytokine production and inhibited nuclear factor kappa B (NF-κB signaling pathway, suggesting the beneficial effects of curcumin on AD are attributable to the suppression of neuroinflammation. Attenuation of these beneficial effects occurred when co-administrated with PPARγ antagonist GW9662 or silence of PPARγ gene expression, indicating that PPARγ might be involved in anti-inflammatory effects. Circular dichroism and co-immunoprecipitation analysis showed that curcumin directly bound to PPARγ and increased the transcriptional activity and protein levels of PPARγ. Taking together, these data suggested that PPARγ might be a potential target of curcumin, acting to alleviate neuroinflammation and improve neuronal function in AD. 6. Survey of radioactive contamination of foodstuffs International Nuclear Information System (INIS) Lee, W. R.; Lee, C. W.; Choi, G. S.; Cho, Y. H.; Kang, M. J.; Cheong, K. H.; Kim, H. R.; Kwak, J. Y. 2005-11-01 The purpose of this study is to survey and assess radioactive contamination of foodstuffs in order to reduce the probability of intake of contaminated foodstuffs. Based on survey and assessment, final goal is to improve the public health by radiation protection. Sampled foodstuffs items are collected from the markets : one group are imported foodstuffs and the other group are domestic foodstuffs producted around nuclear facilities. After pretreatments such as drying, ashing, and homogenization, all samples were analyzed by gamma spectrometer system. The 137 Cs radionuclide was only measured among the regulation radionuclides ( 137 Cs, 134 Cs, 131 I) of food code. All radionuclides of the domestic foodstuffs collected around nuclear facilities were below Minimum Detectable Activity (MDA). But the activity concentrations of Inonotus obliquus (Chaga mushooms) from Russia ranged up to 171.27 (average value : 36.65) Bq/kg-fresh. In the case of blueberry jam, the radioactivity of 137 Cs is higher than expected value. Other samples are below MDA except some spices. Based on the previous and present results, it should be strengthen to survey for Inontus obliquus (Chaga mushooms), of which the radioactivity shows the range from MDA up to 800.01 Bq/kg-fresh. It should assess the public radiation exposure via food chain because it has the excess provability of the maximum permitted level of food code, which is regulation of KFDA. The development method based on international standard would be used at radioactive analysis as well as education of practical workers and it could be applied as the basis data for amending the analysis method of food code. Our country only surveys gamma emitting radionuclides till now but international organization or foreign countries for example EU survey alpha and beta emitting radionuclides as well as gamma emitting radionuclides. So our country should also research necessity of survey for alpha and beta emitting radionuclides 7. Survey of radioactive contamination of foodstuffs Energy Technology Data Exchange (ETDEWEB) Lee, W. R.; Lee, C. W.; Choi, G. S.; Cho, Y. H.; Kang, M. J.; Cheong, K. H.; Kim, H. R.; Kwak, J. Y 2005-11-15 The purpose of this study is to survey and assess radioactive contamination of foodstuffs in order to reduce the probability of intake of contaminated foodstuffs. Based on survey and assessment, final goal is to improve the public health by radiation protection. Sampled foodstuffs items are collected from the markets : one group are imported foodstuffs and the other group are domestic foodstuffs producted around nuclear facilities. After pretreatments such as drying, ashing, and homogenization, all samples were analyzed by gamma spectrometer system. The {sup 137}Cs radionuclide was only measured among the regulation radionuclides ({sup 137}Cs, {sup 134}Cs, {sup 131}I) of food code. All radionuclides of the domestic foodstuffs collected around nuclear facilities were below Minimum Detectable Activity (MDA). But the activity concentrations of Inonotus obliquus (Chaga mushooms) from Russia ranged up to 171.27 (average value : 36.65) Bq/kg-fresh. In the case of blueberry jam, the radioactivity of {sup 137}Cs is higher than expected value. Other samples are below MDA except some spices. Based on the previous and present results, it should be strengthen to survey for Inontus obliquus (Chaga mushooms), of which the radioactivity shows the range from MDA up to 800.01 Bq/kg-fresh. It should assess the public radiation exposure via food chain because it has the excess provability of the maximum permitted level of food code, which is regulation of KFDA. The development method based on international standard would be used at radioactive analysis as well as education of practical workers and it could be applied as the basis data for amending the analysis method of food code. Our country only surveys gamma emitting radionuclides till now but international organization or foreign countries for example EU survey alpha and beta emitting radionuclides as well as gamma emitting radionuclides. So our country should also research necessity of survey for alpha and beta emitting 8. Immunoglobulin heavy and light chains and T-cell receptor beta and gamma chains PCR assessment on cytological samples. A study comparing FTA cards and cryopreserved lymph node fine-needle cytology. Science.gov (United States) Peluso, A L; Cozzolino, I; Bottiglieri, A; Lucchese, L; Di Crescenzo, R M; Langella, M; Selleri, C; Zeppa, P 2017-06-01 To evaluate and compare the DNA yield and quality extracted from lymph node fine needle cytology (FNC) samples stored on FTA cards to those cryopreserved, and to assess the immunoglobulin heavy and light chains (IGHK) and T-Cell receptor beta and gamma chains (TCRBG) PCR tests. DNA extractions were performed on FNC of 80 non-Hodgkin lymphomas (NHL), four myelomas and 56 benign reactive hyperplasias (BRH) cryopreserved and stored on FTA cards. The JAK2 gene was amplified to assess the DNA integrity and the IGHK/TCRBG clonality status was tested. IGHK monoclonality was found in 99% of B-cell NHL and 100% of myeloma. TCRBG monoclonality was found in 100% of T-cell NHL. TCRBG polyclonality was detected in 97% of B-cell NHL, 100% of myeloma and 96% of BRH. IGHK/TCRBG PCR data were confirmed by histological and/or follow-up controls. No differences were found in the DNA quality between cryopreservation and FTA cards storage methods. IGHK/TCRBG PCR of the lymphoproliferative process on FTA cards is comparable to those cryopreserved. FTA cards can be used to store lymph node FNC for further molecular investigations. © 2016 John Wiley & Sons Ltd. 9. Effect of gamma radiation on the activity of alpha and beta amylases in germinating fenugreek (Trigonella foenum-Graceum, L.) beans International Nuclear Information System (INIS) Yacoub, N.J. 1978-01-01 In previous experiments, three weeks old cotyledons from gamma irradiated seeds of fenugreek beans were observed to be healthier and heavier than their non-irradiated controls. A hypothesis was set that this phenomenon was due to the accumulation of carbohydrate in the cotyledons. To test this hypothesis an experiment was designed to determine the sugars and starch contents in the cotyledons of an irradiated and nonirradiated groups at different stages of development. At the same time the amylases activities in the same groups were assayed. Results indicated that there was actually increased amount of sugars ad starch in the two and three week old cotyledons of the irradiated as compared to their controls group. These findings support the above hypothesis. The amylase activities were also higher in the irradiated groups as compared to their non-irradiated controls. These results suggest that irradiation induced stimulation of the photosynthetic rate, and amylases' activities, meanwhile, slowed the translocation of carbohydrate nutrients from the cotyledons into the growing seedlings 10. Machine for checking the radioactive contamination of clothing (1961); Machine a controler le linge du point de vue de sa contamination radioactive (1961) Energy Technology Data Exchange (ETDEWEB) Mimaud, R; Cottignies, S [Commissariat a l' Energie Atomique, Centre de Production de Plutonium, Marcoule (France). Centre d' Etudes Nucleaires 1961-07-01 This machine is designed to check working clothes after decontamination treatment. It checks automatically for {alpha} and {beta} {gamma} The clothing is carried on a moving belt under a rack of Geiger-Muller counters followed by zinc sulphide scintillators linked to photomultipliers. During its passage under these probes two separate counting systems count the {beta} {gamma} and the {alpha} activities. If a certain fixed rate is reached, a basket reserved for contaminated linen moves into position in front of the belt to collect the clothing; if this rate is not attained the linen is collected in another basket. The starting and stopping of counting, and the return to zero, are controlled by means of 3 photoelectric cells which detect the arrival of the clothing before and after scanning, and its delivery into the baskets. (authors) [French] Cette machine est destinee a controler les vetements de travail apres le traitement de decontamination. Elle effectue automatiquement un controle en {alpha} et en {beta} {gamma}. Le linge entraine par un tapis roulant passe sous une rampe de compteurs Geiger-Muller puis sous des scintillateurs au sulfure de zinc associes a des photomultiplicateurs. Pendant son passage sous ces sondes, deux chaines de comptage distinctes comptent l'activite {beta} {gamma} et l'activite {alpha}. Si un certain taux fixe est atteint, un panier reserve au linge contamine se positionne devant le tapis pour recueillir le linge; dans le cas contraire, le linge est recueilli dans un autre panier. Les operations de debut de comptage, arret de comptage et remise a zero de l'ensemble sont commandees a l'aide de 3 cellules photoelectriques qui detectent l'arrivee du linge avant et apres les sondes, ainsi que sa retombee dans les paniers. (auteurs) 11. Gamma environmental dosimetry and radon concentration in Venezuela International Nuclear Information System (INIS) Sajo B, L.; Greaves E, D. 1996-01-01 The environmental radiation levels have been determined in Venezuela by means of different techniques including the passive dosimeters and the alpha and gamma dosimetry besides the gross alpha/beta counting. The most important conclusion is that the presence of artificial radionuclides (Cesium-137, Beryllium-7 and Cadmium-109) was observed in different environmental samples and in food considered contaminant. The values of gamma levels are between 28 and 40 mGy/day and the mean value of radon concentration in closed environment is 36 Bq/m 3 ; the higher values of a factor 10 have been measured in the Andes region. The 20% of analysed drinking water has a concentration of alpha radionuclides emitters less than 0.005 Bq/l and only the 8% is greater than 0.450 Bq/l. (authors). 6 refs., 1 fig 12. Determination of alternative conditions for instruments calibration with beta radiation International Nuclear Information System (INIS) Rocha, F.D.G.; Caldas, L.V.E. 1992-01-01 The influence of homogenization filter in the determination of chamber calibration factors and transmission factors of beta radiation in air, for obtaining different alternative conditions for beta-gamma portable monitors calibration was studied, using an extrapolation chamber and the beta secondary system at IPEN-CNEN-Brazil. (C.G.C.) 13. Characterization of radioactive contamination inside pipes with the Pipe Explorer trademark system International Nuclear Information System (INIS) Lowry, W. 1994-01-01 The objective for the development of the Pipe Explorer trademark radiological characterization system is to achieve a cost effective, low risk means of characterizing gamma radioactivity on the inside surface of pipes. The unique feature of this inspection system is the use of a pneumatically inflated impermeable membrane which transports the detector into the pipe as it inverts. The membrane's internal air pressure tows the detector and tether through the pipe. This mechanism isolates the detector and its cabling from the contaminated surface, yet allows measurement of radioactive emissions which can readily penetrate the thin plastic membrane material (such as gamma and high energy beta emissions). In Phase 1, an initial survey of DOE facilities was conducted to determine the physical and radiological characteristics of piping systems. The inverting membrane deployment system was designed and extensively tested in the laboratory. A range of membrane materials was tested to evaluate their ruggedness and deployment characteristics. Two different sizes of gamma scintillation detectors were procured and tested with calibrated sources. Radiation transport modeling evaluated the measurement system's sensitivity to detector position relative to the contaminated surface, the distribution of the contamination, background gamma levels, and gamma source energy levels. In the culmination of Phase 1, a field demonstration was conducted at the Idaho National Engineering Laboratory's Idaho Chemical Processing Plant. The project is currently in transition from Phase 1 to Phase 2, where more extensive demonstrations will occur at several sites. Results to date are discussed 14. Neural rhythmic symphony of human walking observation: Upside-down and Uncoordinated condition on cortical theta, alpha, beta and gamma oscillations. Directory of Open Access Journals (Sweden) David eZarka 2014-09-01 Full Text Available Biological motion observation has been recognized to produce dynamic change in sensorimotor activation according to the observed kinematics. Physical plausibility of the spatial-kinematic relationship of human movement may play a major role in the top-down processing of human motion recognition. Here, we investigated the time course of scalp activation during observation of human gait in order to extract and use it on future integrated brain-computer interface using virtual reality (VR. We analyzed event related potentials (ERP, the event related spectral perturbation (ERSP and the inter-trial coherence (ITC from high-density EEG recording during video display onset (-200 to 600 ms and the steady state visual evoked potentials (SSVEP inside the video of human walking 3D-animation in three conditions: Normal; Upside-down (inverted images; and Uncoordinated (pseudo-randomly mixed images. We found that early visual evoked response P120 was decreased in Upside-down condition. The N170 and P300b amplitudes were decreased in Uncoordinated condition. In Upside-down and Uncoordinated conditions, we found decreased alpha power and theta phase-locking. As regards gamma oscillation, power was increased during the Upside-down animation and decreased during the Uncoordinated animation. An SSVEP-like response oscillating at about 10 Hz was also described showing that the oscillating pattern is enhanced 300 ms after the heel strike event only in the Normal but not in the Upside-down condition. Our results are consistent with most of previous point-light display studies, further supporting possible use of virtual reality for neurofeedback applications. 15. ASSESSMENTOF BETA PARTICLE FLUX FROM SURFACE CONTAMINATION AS A RELATIVE INDICATOR FOR RADIONUCLIDE DISTRIBUTION ON EXTERNAL SURFACES OF A MULTI-STORY BUILDING IN PRIPYAT Energy Technology Data Exchange (ETDEWEB) Farfan, E. 2009-11-17 How would we recover if a Radiological Dispersion Device (e.g., dirty bomb) or Improvised Nuclear Device were to detonate in a large city? In order to assess the feasibility of remediation following such an event, several issues would have to be considered, including the levels and characteristics of the radioactive contamination, the availability of the required resources to accomplish decontamination, and the planned future use of the city's structures and buildings. Presently little is known about the distribution, redistribution, and migration of radionuclides in an urban environment. However, Pripyat, a city substantially contaminated by the Chernobyl Nuclear Power Plant accident, may provide some answers. The main objective of this study was to determine the radionuclide distribution on a Pripyat multi-story building, which had not been previously decontaminated and therefore could reflect the initial fallout and its further natural redistribution on external surfaces. The 7-story building selected was surveyed from the ground floor to the roof on horizontal and vertical surfaces along seven ground-to-roof transections. Some of the results from this study indicate that the upper floors of the building had higher contamination levels than the lower floors. The authors consequently recommend that existing decontamination procedures for tall structures be re-examined and modified accordingly. 16. Beta emitter radionuclides (90Sr contamination in animal feed: validation and application of a radiochemical method by ultra low level liquid scintillation counting Directory of Open Access Journals (Sweden) Marco Iammarino 2015-02-01 Full Text Available 90Sr is considered as a dangerous contaminant of agri-food supply chains due to its chemical affinity with Calcium, which makes its absorption in bones easy. 90Sr accumulation in raw materials and then in final products is particularly significant in relationship to its ability to transfer into animal source products. The radionuclides transfer (137Cs and 90Sr from environment to forages and then to products of animal origin (milk, cow and pork meats was studied and evaluated in different studies, which were carried out in contaminated areas, from Chernobyl disaster until today. In the present work, the development and validation of a radiochemical method for the detection of 90Sr in different types of animal feed, and the application of this technique for routinely control activities, are presented. Liquid scintillation counting was the employed analytical technique, since it is able to determine very low activity concentrations of 90Sr (<0.01 Bq kg–1. All samples analysed showed a 90Sr contamination much higher than method detection limit (0.008 Bq kg–1. In particular, the highest mean activity concentration was registered in hay samples (2.93 Bq kg–1, followed by silage samples (2.07 Bq kg–1 and animal feeds (0.77 Bq kg–1. In fact, all samples were characterized by 90Sr activity concentrations much lower than reference limits. This notwithstanding, the necessity to monitor these levels was confirmed, especially considering that 90Sr is a possible carcinogen for human. 17. Tipified conditions for irradiation of equipment and personnel and gamma radiation spectral-angular parameters of radioactively contaminated area of the Chernobyl' accident International Nuclear Information System (INIS) Melent'ev, A.B.; Frid, E.S.; Shekhanov, G.A.; Zhitnik, A.K.; Shanenko, A.A. 1992-01-01 The analysis and calculated-experimental investigations were presented. The tipified conditions for irradiation of the equipment and the personnel as the result of destroys in the Chernobyl' NPP and initial data of spectral-angular parameters of gamma radiated sites were proposed. The results of the investigation may be used in the prediction of radiation effect on the personnel as well as during design and estimation of the effective protection from gamma radiation. 3 refs.; 7 refs 18. Use of low doses of cobalt 60 gamma radiation on beet (Beta vulgaris L.), carrot (Daucus carota L.) and radish (Raphanus sativus L.) seed to stimulate increase yield; Emprego da radiacao gama do cobalto 60 em sementes de beterraba (Beta vulgaris L.), cenoura (Daucus carota L.) e rabanete (Raphanus sativus L.) para estimular o aumento da producao Energy Technology Data Exchange (ETDEWEB) Bovi, Jose Eduardo 2000-07-01 The research had the aim of evaluating the effects of low doses of Cobalt-60 gamma radiation on seeds of radish (Raphanus sativus L.) cultiva Champion, cultivars Nantes Forto (european origin) and Brasilia (Rio Grande do Sul origin) carrot (Daucus carota L. var. sativus (Hoffm.) Thell), and red beet (Beta vulgaris L.) cultivar Tall Top Early Wonder before sowing, its effects on plant growth, on the yield and roots storage of two tillages: with sowing in the same day of radiation and six days after radiation seeds. The data showed that the seeds radiation did not interfered negatively on plants growth, and the species presented differences as roots production and doses on both plantation: radish with 5,0 Gy and 2,5 Gy doses respectively to the first and the second sowings, Brasilia carrot with 2,5 Gy dose to both sowings. Nantes carrot with 2,5 Gy and 5,0 Gy respectively to the first and the second sowings, and beet with 7,5 Gy and 5,0 Gy respectively to the first and the second plantations. There is not statistics difference by Tukey test (5% and 1%) and none relation between seeds radiation and loss weight on roots storage. (author) 19. The development of the American National Standard 'control of radioactive surface contamination on materials equipment and facilities to be released for uncontrolled use' International Nuclear Information System (INIS) Shapiro, J. 1980-01-01 A new standard submitted by the Health Physics Society Standards Committee to the American National Standards Institute concerning radioactive surface contamination of materials and equipment is discussed. The chronological events in the development of this standard are given. The standard provides criteria for the release for uncontrolled use of materials, equipment and facilities contaminated or potentially contaminated with radioactivity. Permissible contamination limits are specified for: 1) long lived alpha emitters except natural uranium and thorium, 2) more hazardous beta-gamma emitters, 3) less hazardous beta-gamma emitters and 4) natural uranium and thorium. A contamination reference level of 1000 dpm/100 cm 2 for 90 Sr was set as the basis for assigning limits to radionuclides presenting an ingestion hazard and other radionuclides were grouped based on the values of their maximum permissible concentration (MPC) in water relative to 90 Sr. The contamination limit for 239 Pu was chosen as the basis for assigning limits based on MPC in air to radionuclides presenting an inhalation hazard; a value of 100 dpm/100 cm 2 was adopted in the standard. An upper limit of 5000 dpm/100 cm 2 for surface contamination was selected for the standard. (UK) 20. Beta spectrometry International Nuclear Information System (INIS) Dryak, P.; Zderadicka, J.; Plch, J.; Kokta, L.; Novotna, P. 1977-01-01 For the purpose of beta spectrometry, a semiconductor spectrometer with one Si(Li) detector cooled with liquid nitrogen was designed. Geometrical detection efficiency is about 10% 4 sr. The achieved resolution for 624 keV conversion electrons of sup(137m)Ba is 2.6 keV (FWHM). A program was written in the FORTRAN language for the correction of the deformation of the measured spectra by backscattering in the analysis of continuous beta spectra. The method permits the determination of the maximum energy of the beta spectrum with an accuracy of +-5 keV. (author) 1. A semiconductor beta ray spectrometer International Nuclear Information System (INIS) Bom, V.R. 1987-01-01 Measurement of energy spectra of beta particles emitted from nuclei in beta-decay processes provides information concerning the mass difference of these nuclei between initial and final state. Moreover, experimental beta spectra yield information on the feeding of the levels in the daughter nucleus. Such data are valuable in the construction and checking of the level schemes. This thesis describes the design, construction, testing and usage of a detector for the accurate measurement of the mentioned spectra. In ch. 2 the design and construction of the beta spectrometer, which uses a hyper-pure germanium crystal for energy determination, is described. A simple wire chamber is used to discriminate beta particles from gamma radiation. Disadvantages arise from the large amounts of scattered beta particles deforming the continua. A method is described to minimize the scattering. In ch. 3 some theoretical aspects of data analysis are described and the results of Monte-Carlo simulations of the summation of annihilation radiation are compared with experiments. Ch. 4 comprises the results of the measurements of the beta decay energies of 103-108 In. 87 refs.; 34 figs.; 7 tabs 2. Beta Blockers Science.gov (United States) ... may not work as effectively for people of African heritage and older people, especially when taken without ... conditions/high-blood-pressure/in-depth/beta-blockers/ART-20044522 . Mayo Clinic Footer Legal Conditions and Terms ... 3. Inactivation of contaminated fungi and antioxidant effects of peach (Prunus persica L. Batsch cv Dangeumdo) by 0.5-2 kGy gamma irradiation Energy Technology Data Exchange (ETDEWEB) Kim, Kyoung-Hee; Kim, Mi-Seon [Department of Food and Nutrition, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Kim, Hong-Gi [Department of Applied Biology, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Yook, Hong-Sun, E-mail: yhsuny@naver.co [Department of Food and Nutrition, Chungnam National University, Daejeon 305-764 (Korea, Republic of) 2010-04-15 The effect of gamma irradiation (0.5-2 kGy) on the physicochemical properties of peaches was investigated during a 6-day storage at 20+-3 deg. C. Gamma irradiation is able to inactivate the four pathogens, namely Botrytis cinerea, Penicillium expansum, Rhizopus stolonifer var. stolonifer and Monilinia fructicola in peaches. Hardness significantly decreased with the increment of irradiation dose level whereas soluble solid and total polyphenol contents increased with increment of irradiation dose level. 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity of the irradiated peach was higher than that of control, and its activity increased with increment of irradiation dose level. These results suggest that gamma irradiation of peaches improved antioxidant activity, but dramatically affects the hardness throughout the entire storage time. 4. Inactivation of contaminated fungi and antioxidant effects of peach (Prunus persica L. Batsch cv Dangeumdo) by 0.5-2 kGy gamma irradiation International Nuclear Information System (INIS) Kim, Kyoung-Hee; Kim, Mi-Seon; Kim, Hong-Gi; Yook, Hong-Sun 2010-01-01 The effect of gamma irradiation (0.5-2 kGy) on the physicochemical properties of peaches was investigated during a 6-day storage at 20±3 deg. C. Gamma irradiation is able to inactivate the four pathogens, namely Botrytis cinerea, Penicillium expansum, Rhizopus stolonifer var. stolonifer and Monilinia fructicola in peaches. Hardness significantly decreased with the increment of irradiation dose level whereas soluble solid and total polyphenol contents increased with increment of irradiation dose level. 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity of the irradiated peach was higher than that of control, and its activity increased with increment of irradiation dose level. These results suggest that gamma irradiation of peaches improved antioxidant activity, but dramatically affects the hardness throughout the entire storage time. 5. Design and Development of Hand and Foot Contamination Monitor Directory of Open Access Journals (Sweden) F. Akter 2014-08-01 Full Text Available A hand and foot contamination monitor is a health physics instrument to provide detection and measurement of beta-gamma contamination on the palm of each hand and on the bottom surface of both feet/shoes. There are four channels of detection for two hands and two feet. Four G-M detectors have been used in a single unit to cover the whole area of hand and feet. A regulated high voltage DC power supply (900 V has been designed using the PIC12F675 microcontroller to operate the pancake Geiger-Müller detectors. The reading is displayed on a linearly scaled 0-100 Bq/cm2 analog panel meter. The monitor detects beta–gamma radiation emitted by radioactive materials, and if the detected value exceeds a preset level, the monitor sounds an alarm and displays a reading in the respective panel meter. Indicator lamps are used to show the status of contamination. The performance of the system has been tested by using pulse generator and by flat surface radioactive calibration sources. Electronic linearity, detection efficiency, response to the contamination, calibration factor and percentage of error has been measured. Test results were satisfactory and the present system can be used instead of similar imported instruments. 6. Cytokines interleukin-1beta and tumor necrosis factor-alpha regulate different transcriptional and alternative splicing networks in primary beta-cells DEFF Research Database (Denmark) Ortis, Fernanda; Naamane, Najib; Flamez, Daisy 2010-01-01 by the cytokines interleukin (IL)-1beta + interferon (IFN)-gamma and tumor necrosis factor (TNF)-alpha + IFN-gamma in primary rat beta-cells. RESEARCH DESIGN AND METHODS: Fluorescence-activated cell sorter-purified rat beta-cells were exposed to IL-1beta + IFN-gamma or TNF-alpha + IFN-gamma for 6 or 24 h......-cells, with temporal differences in the number of genes modulated by IL-1beta + IFNgamma or TNF-alpha + IFN-gamma. These cytokine combinations induced differential expression of inflammatory response genes, which is related to differential induction of IFN regulatory factor-7. Both treatments decreased the expression...... of genes involved in the maintenance of beta-cell phenotype and growth/regeneration. Cytokines induced hypoxia-inducible factor-alpha, which in this context has a proapoptotic role. Cytokines also modified the expression of >20 genes involved in RNA splicing, and exon array analysis showed cytokine... 7. Accurate Determination of Leucine and Valine Side-chain Conformations using U-[{sup 15}N/{sup 13}C/{sup 2}H]/[{sup 1}H-(methine/methyl)-Leu/Val] Isotope Labeling, NOE Pattern Recognition, and Methine C{gamma}-H{gamma}/C{beta}-H{beta} Residual Dipolar Couplings Energy Technology Data Exchange (ETDEWEB) Tang, Chun; Iwahara, Junji; Clore, G. Marius [National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Laboratory of Chemical Physics (United States)], E-mail: mariusc@intra.niddk.nih.gov 2005-10-15 An isotope labeling scheme is described in which specific protonation of methine and methyl protons of leucine and valine is obtained on a {sup 15}N/{sup 13}C labeled background with uniform deuteration of all other non-exchangeable protons. The presence of a protonated methine group has little effect on the favorable relaxation properties of the methyl protons of Leu and Val. This labeling scheme permits the rotameric state of leucine side-chains to be readily determined by simple inspection of the pattern of H{gamma}(i)-H{sub N}(i) and H{gamma}(i)-H{sub N}(i+1) NOEs in a 3D {sup 15}N-separated NOE spectrum free of complications arising from spectral overlap and spin-diffusion. In addition, one-bond residual dipolar couplings for the methine {sup 13}C-{sup 1}H bond vectors of Leu and Val can be accurately determined from an intensity J-modulated constant-time HCCH-COSY experiment and used to accurately orient the side-chains of Leu and Val. Incorporation of these data into structure refinement improves the accuracy with which the conformations of Leu and Val side-chains can be established. This is important to ensure optimal packing both within the protein core and at intermolecular interfaces. The impact of the method on protein structure determination is illustrated by application to enzyme IIA{sup Chitobiose}, a 34 kDa homotrimeric phosphotransferase protein. 8. Industrial radiography. Gamma radiography International Nuclear Information System (INIS) Menetrier, J. 1975-01-01 Informations are given on gamma radiodefectology regulations, entire references and main dispositions applicable to each state of the European Economic Community. The content includes previous arrangements for source acquisition, holding and use of the sources, transport, accidents, civil liability of the source holder, person insurance against radiation hazards and contamination, property insurance, penal liability of the source holder 9. Development of plastic scintillator based food radioactivity contamination monitoring system International Nuclear Information System (INIS) Parihar, A.; Sahani, R.M.; Mahala, V.K.; Vaijapurkar, S.G. 2016-01-01 Radioactivity is naturally present in soil, water and food stuffs. Food can be contaminated after discharge of radioactivity into the environment from industries that concentrate natural radionuclide and from civil or military nuclear operations. The contamination can be in three ways; by direct deposition, through the food chain and induced radioactivity due to exposure of high neutron flux. The health effects on human depend on the type of radionuclide and the length of time people are exposed to it. The studies of fission product behaviour in the food chain have revealed radionuclide Strontium-90, Caesium 137 and Iodine-131 are of major concern. Plastic scintillator is already developed indigenously at Defence Laboratory, Jodhpur. Efforts has been made to develop a portable field instrument using plastic scintillator for assessment of beta ( 90 Sr) and gamma ( 137 Cs and 131 I) radioactivity in food 10. Determination of the kalium-subtracted total beta in food International Nuclear Information System (INIS) Liu Guofan 1985-01-01 A procedure for measuring the kalium-subtracted total beta in food can be applied to estimating the contamination of beta nuclides except 40 K. The procedure, calculating formula, and some experiences in practice are described in this paper. The method is simple, rapid, and very useful to food contamination monitoring 11. T-cell receptor gamma delta bearing cells in normal human skin NARCIS (Netherlands) Bos, J. D.; Teunissen, M. B.; Cairo, I.; Krieg, S. R.; Kapsenberg, M. L.; Das, P. K.; Borst, J. 1990-01-01 T-cell antigen receptors (TCR) are divided into common alpha beta and less common gamma delta types. In the murine skin, TCR gamma delta+ cells have been reported to form the great majority of epidermal T lymphocytes. We have examined the relative contribution of TCR alpha beta+ and TCR gamma delta+ 12. Detection of leaded-gasoline usage in catalyst-equipped vehicles: a gamma-ray transmission guage for measuring catalytic converter lead contamination International Nuclear Information System (INIS) Schneider, E.W. 1982-01-01 A gamma-ray transmission gauge has been developed for measuring the accumulation of lead inside the catalytic converters of vehicles operated on leaded gasoline. This nondestructive inspection system relates the amount of gamma radiation passing through the catalytic converter to the mass concentration of lead contained in the catalyst bed. Field studies have shown that vehicle usage of 200 L of leaded gasoline (0.34 g of Pb/L) can be detected at the 95% confidence level. Based on tests with one vehicle burning 1000 L of leaded gasoline, the accumulation rate of lead on the catalytic converter was relatively constant, accounting for 45% of the total lead consumed. Subsequent usage of unleaded gasoline resulted in no significant loss of lead from the catalytic converter 13. Use of gamma spectroscopy in activation analysis; Utilisation de la spectrographie gamma dans l'analyse par activation Energy Technology Data Exchange (ETDEWEB) Leveque, [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires 1959-07-01 Brief review of the principles of activation analysis: calculation of activities, decay curves, {beta} absorption curves, examples of application. - Principle and description of the {gamma} spectrograph. - Practical utilisation of the {gamma} spectrograph: analysis by activation, analysis by {beta} - x fluorescence. - Sensitivity limit of the method and precision of the measurements. - Possible improvements to the method: {gamma} spectroscopy with elimination of the Compton effect. (author) [French] Bref rappel des principes de l'analyse par activation: calcul des activites, courbes de decroissance, courbes d'absorption {beta}, exemples d'utilisation. - Principe et description du spectrographe {gamma}. - Utilisation pratique de la spectrographie {gamma}: analyse par activation, analyse par fluorescence {beta} - x. - Limite de sensibilite de la methode et precision des mesures. - Ameliorations possibles de la methode: spectrographe {gamma} avec elimination de l'effet Compton. (auteur) 14. Novel Polymorphisms of Adrenergic, Alpha-1B-, Receptor and Peroxisome Proliferator-activated Receptor Gamma, Coactivator 1 Beta Genes and Their Association with Egg Production Traits in Local Chinese Dagu Hens Directory of Open Access Journals (Sweden) F. Mu 2016-09-01 Full Text Available Adrenergic, alpha-1B-, receptor (ADRA1B and peroxisome proliferator-activated receptor gamma, coactivator 1 beta (PPARGC1B genes are involved in regulation of hen ovarian development. In this study, these two genes were investigated as possible molecular markers associated with hen-housed egg production, egg weight (EW and body weight in Chinese Dagu hens. Samples were analyzed using the polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP technique, followed by sequencing analysis. Two novel single nucleotide polymorphisms (SNPs were identified within the candidate genes. Among them, an A/G transition at base position 1915 in exon 2 of ADRA1B gene and a T/C mutation at base position 6146 in the 3′-untranslated region (UTR of PPARGC1B gene were found to be polymorphic and named SNP A1915G and T6146C, respectively. The SNP A1915G (ADRA1B leads to a non-synonymous substitution (aspartic acid 489-to-glycine. The 360 birds from the Dagu population were divided into genotypes AA and AG, allele A was found to be present at a higher frequency. Furthermore, the AG genotype correlated with significantly higher hen-housed egg production (HHEP at 30, 43, 57, and 66 wks of age and with a higher EW at 30 and 43 wks (p<0.05. For the SNP T6146C (PPARGC1B, the hens were typed into TT and TC genotypes, with the T allele shown to be dominant. The TC genotype was also markedly correlated with higher HHEP at 57 and 66 wks of age and EW at 30 and 43 wks (p<0.05. Moreover, four haplotypes were reconstructed based on these two SNPs, with the AGTC haplotype found to be associated with the highest HHEP at 30 to 66 wks of age and with higher EW at 30 and 43 wks (p<0.05. Collectively, the two SNPs identified in this study might be used as potential genetic molecular markers favorable in the improvement of egg productivity in chicken breeding. 15. Beta-decay of {sup 56}Cu Energy Technology Data Exchange (ETDEWEB) Ramdhane, M.; Baumann, P.; Knipper, A.; Walter, G. [Institute de Recherches Subatomiques, 67 - Strasbourg (France); Janas, Z.; Plochocki, A. [Warsaw Univ. (Poland). Inst. of Experimental Physics; Aeystoe, J.; Dendooven, P.; Jokinen, A.; Oinonen, M.; Pentilae, H. [Jyvaeskylae Univ. (Finland); Liu, W.; Grawe, H.; Hu, Z.; Kirchner, R.; Klepper, O.; Roeckl, E. [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany); Gorska, M. [Warsaw Univ. (Poland). Inst. of Experimental Physics]|[Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany); Fujita, Y. [Osaka Univ. (Japan); Brown, B.A. [Michigan State Univ., East Lansing, MI (United States) 1998-02-01 By measuring positrons and {beta}-delayed {gamma}-rays emitted from mass-separated sources, the decay of {sup 56}Cu(4{sup +},T{sub z}=-1,T=1) to states in the doubly-magic nucleus {sup 56}Ni was studied for the first time. The half-life of {sup 56}Cu was measured to be 78(15) ms, and four {beta}-delayed {gamma}-rays were assigned to its decay. The resulting experimental data on Fermi and Gamow-Teller strength are compared with shell-model predictions. (orig.) 16. Methodology for solving the problem of contamination in pencils of Co-60 from the CNEA (Argentine) for the recharge of the gamma irradiator of the ININ International Nuclear Information System (INIS) Villarreal B, J.E.; Escobar A, L.; Angeles C, A.; Cruz G, H.S. 1992-07-01 Presently report the methodology used to identify the source of contamination detected in a shipment with 5.0 X 10 Bq of Co-60 coming from Argentina is described, as well as the solution outlined to solve the problem. Its are presented by way of conclusion the experiences but outstanding learned in the process. (Author) 17. Deletion of a region that is a candidate for the difference between the deletion forms of hereditary persistence of fetal hemoglobin and deltabeta-thalassemia affects beta- but not gamma-globin gene expression. NARCIS (Netherlands) R. Calzolari (Roberta); T. McMorrow (Tara); N. Yannoutsos (Nikos); A. Langeveld (An); F.G. Grosveld (Frank) 1999-01-01 textabstractThe analysis of a number of cases of beta-globin thalassemia and hereditary persistence of fetal hemoglobin (HPFH) due to large deletions in the beta-globin locus has led to the identification of several DNA elements that have been implicated in the switch 18. Effects of the gamma and ultrasound radiation in orange juice contaminated by Alicyclobacillus acidoterrestris;Efeitos das radiacoes gama e ultra-sonica em suco de laranja contaminado por Alicyclobacillus acidoterrestris Energy Technology Data Exchange (ETDEWEB) Pires, Cristiane Cassiolato, E-mail: cristiane_cassiolato@yahoo.com.b 2006-07-01 The orange juice has attributes could make that hard or even block the growth. of microorganisms, even so already have been isolated filamentous fungi, yeast, as well lactic and heat resistant bacteria. Alicyclobacillus acidoterrestris is a heat resistant bacteria that has done damage in the orange juice concentrated and frozen business. This bacterium is able the grown in temperatures below 35 deg C constituting a risk to orange juices that have been contaminated. Even those that already pass trough thermal treatment may deteriorated, if they are storage in place without refrigeration. As the traditional methods of decontamination and conservation have not been effective in unfeasible this bacterium, others methods of sterilization are need, among them are gamma and ultrasound radiation. The gamma radiation is able to sterilize foods and reduce the microbiology density, allowing in this way to enhance the period of storage. The ultrasound application has been used currently with the aim to microbiology control, been this technique effective in the microbial cell destruction. The Brazil, are the major producer and exporter of concentrated frozen orange juice, due to it, the present work was carried out to two experiments with the aim to determinate the resistance of the bacterium Alicyclobacillus acidoterrestris to gamma and ultrasound irradiation, in the orange juice, priory contaminated. The orange juice samples was diluted to 11,5 deg Brix and the bacteria suspensions was added, passed by process of radiation gamma with dose of 0, 2, 4, 6 and 8 kGy and ultrasonic with the frequency of 25, 35 and 42 kHz and with the time of exposition of 0, 1, 5, 10 and 20 minutes. After the treatment, the samples were stored in room temperature (25 +- 2 deg C) and of refrigeration (4 +- 1 deg C). For the microbial analyses, the samples were diluted in to decimal scale, plated by 'pour plate' technique. The Petri plates were storage in warn temperature (46 +- 2 deg C 19. Application of low-dose gamma irradiation to extend the shelf life of minimally processed Red Beet (Beta vulgaris sp. vulgaris L.), cv. Early Wonder; Aplicacao de baixas doses de radiacao gama para extensao da vida util de beterraba vermelha (Beta vulgaris ssp. vulgaris L.), cv. Early Wonder, minimamente processada Energy Technology Data Exchange (ETDEWEB) Hernandez, Nilber Kenup 2006-07-01 This study was aimed at investigating the effects of low-dose gamma irradiation on shelf-life extension and phyto sanitary safety of minimally processed red beet with basis on physicochemical; microbiological; chemical and sensory analyses. The samples (Beta vulgaris ssp. vulgaris L.), Early Wonder cultivar, were cultivated in the experimental area of the Horticulture Sector of the Departamento de Fitotecnia of the Instituto de Agronomia, Universidade Federal Rural do Rio de Janeiro, Seropedica, RJ, as part of two experiments performed during the second semester of 2005. In each experiment, 1200 plants (40 per linear meter of terrain) were sowed. Physicochemical analyses (fresh mass; length; average diameter and total soluble solids) of the edible part of the red beets (their tuberous roots) were periodically carried out in order to assess the most appropriate time for harvest by monitoring the development of the plants. Those times were found to be 104 and 73 days after transplanting, respectively. The harvested edible part of the roots were minimally processed and separated in two groups: (1) gamma irradiated (with doses of 0.5; 1.0 and 1.5 kGy) and (2) non-irradiated (control). All samples were stored at 8 degree C. Microbiological analyses were performed during the storage period (22 and 21 days, for experiments 1 and 2, respectively) in order to evaluate the phyto sanitary quality of the samples (Salmonella sp.; coliforms and total count of mesophilic aerobic and lactic acid bacteria). The samples irradiated with 1.0 and 1.5 kGy were found to remain appropriate for consumption for 21 days, as compared to only 7 days for the control. Monitoring of chemical composition was also performed and included the determination of saccharose; glucose; fructose and vitamins B1 and B2. No difference was found between the concentrations of those vitamins in irradiated and control samples at the end of the storage period, whereas significant changes in sugar contents were 20. Beta decay of twelve light neutron-rich isotopes from 17C to 40S International Nuclear Information System (INIS) Dufour, J.P.; Del Moral, R.; Fleury, A.; Hubert, F.; Jean, D.; Pravikoff, M.S.; Geissel, H.; Schmidt, K.H. 1986-07-01 The results reported here have been obtained with an 40 Argon beam on a Be target. The separated nuclei were implanted in a catcher foil placed in between a thin scintillator detecting the betas and a high volume Ge detector; only gammas in coincidence with betas were recorded. Results for the gamma energies and the half-lives of the observed isotopes are given 1. Monitoring of the internal contamination of occupationally exposure personnel in services of nuclear medicine through the use of gamma cameras; Monitoreo de la contaminacion interna de personal ocupacionalmente expuesto en servicios de medicina nuclear mediante el uso de gamma camaras Energy Technology Data Exchange (ETDEWEB) Teran, M.; Paolino, A.; Savio, E. [Catedra de Radioquimica, Facultad de Quimica, Montevideo (Uruguay); Hermida, J.C. [Centro de Medicina Nuclear, Hospital de Clinicas, Facultad de Medicina, Montevideo (Uruguay); Dantas, B.M. [Laboratorio de Medidas In vivo, Instituto da Radioprotecao e Dosimetria, Rio de Janeiro (Brazil) 2006-07-01 The radionuclides incorporation can happen as a result of diverse activities; these include the work associated with the different stadiums of the nuclear fuel cycle, the use of radioactive sources in medicine, the scientific research, the agriculture and the industry. In Uruguay the main activities linked to the manipulation of open sources correspond those of Nuclear Medicine and from 2004, in the mark of the Project Arcal RLA 049 and being based on the Safety Guides of the IAEA it is implementing a program of internal monitoring in combined form the Nuclear Medicine Center of the Hospital of and the Radiochemistry class of the Faculty of Chemistry. In accordance with the publication of the ICRP 75 the emphasis of any monitoring program should be in the formal study of the doses in the workers to who are considered commendable of to receive in routine form an outstanding fraction of the dose limits or who work in areas where the exposures can be significant in the accident event. From April 2004, to the date has started a pilot plan by means of in that were established appropriate conditions of procedures and of safety in a reduced group of workers of the Nuclear Medicine area. In that period the first work limits, equipment adjustment, calibrations and registration systems were determined. The monitoring system implemented until the moment is carried out with a thyroid caption equipment. However these measurements are carried out in the university hospital embracing 40% of the involved workers of our country, with the purpose of reaching the covering of the biggest quantity of occupationally exposed personnel of private clinics. Also it was developed a new work proposal that allows to have an alternative measure method, in the event of not having the equipment habitually used. Among the conclusions of this work are that for the before exposed are considered the measure conditions but appropriate the following ones: Gamma Camera without collimator; Measurement 2. Study of detectors in beta radiation fields International Nuclear Information System (INIS) Albuquerque, M. da P.P.; Xavier, M.; Caldas, L.V.E. 1987-01-01 Several commercial detectors used with gamma or X radiation are studied. Their sensibility and energetic dependence are analysed in exposures of beta radiation fields. A comparative evaluation with the reference detector (the extrapolation chamber) is presented. (M.A.C.) [pt 3. Microbial diversity in contaminated soils along the T22 trench of the Chernobyl experimental platform Energy Technology Data Exchange (ETDEWEB) Chapon, Virginie [CEA, DSV, IBEB, SBVME, LIPM, F-13108 Saint-Paul-lez-Durance (France); CNRS, UMR 6191, F-13108 Saint-Paul-lez-Durance (France); Universite d' Aix-Marseille, F-13108 Saint-Paul-lez-Durance (France); Piette, Laurie [CEA, DSV, IBEB, SBVME, LIPM, F-13108 Saint-Paul-lez-Durance (France); CNRS, UMR 6191, F-13108 Saint-Paul-lez-Durance (France); Universite d' Aix-Marseille, F-13108 Saint-Paul-lez-Durance (France); Vesvres, Marie-Helene [Universite de Bordeaux 1/CNRS-IN2P3, UMR 5797, CENBG, POB 120, F-33175 Gradignan cedex (France); Coppin, Frederic [IRSN, DEI/SECRE/LRE-Bat 186, B.P.3, Cadarache Center, F-13115 Saint-Paul-lez-Durance cedex (France); Marrec, Claire Le [ISVV, UMR 1219, Institut Polytechnique de Bordeaux/INRA, POB 50008, F-33882 Villenave d' Ornon (France); Christen, Richard [Universite de Nice-Sophia-Antipolis, Centre de Biochimie, Parc Valrose, F-06108 Nice (France); CNRS, UMR 6543, Centre de Biochimie, Parc Valrose, F-06108 Nice (France); Theodorakopoulos, Nicolas [CEA, DSV, IBEB, SBVME, LIPM, F-13108 Saint-Paul-lez-Durance (France); CNRS, UMR 6191, F-13108 Saint-Paul-lez-Durance (France); Universite d' Aix-Marseille, F-13108 Saint-Paul-lez-Durance (France); Universite de Bordeaux 1/CNRS-IN2P3, UMR 5797, CENBG, POB 120, F-33175 Gradignan cedex (France); IRSN, DEI/SECRE/LRE-Bat 186, B.P.3, Cadarache Center, F-13115 Saint-Paul-lez-Durance cedex (France); Fevrier, Laureline [IRSN, DEI/SECRE/LRE-Bat 186, B.P.3, Cadarache Center, F-13115 Saint-Paul-lez-Durance cedex (France); others, and 2012-07-15 The diversity of bacterial communities exposed to radioactive contamination in Chernobyl soils was examined by a combination of molecular and culture-based approaches. A set of six radioactive soil samples, exhibiting high levels of {sup 137}Cs contamination, were collected from the T22 trench. Three samples were also collected in nearby soils with low contamination. Complex bacterial community structures were observed in both highly and weakly contaminated samples, using a molecular approach targeting the 16S rRNA gene. However, the presence of specific populations within samples from highly contaminated soils could not be revealed by statistical analysis of the DGGE profiles. More than 200 culturable isolates, representative of dominant morphotypes, were grouped into 83 Operational Taxonomic Units (OTUs) and affiliated to Firmicutes, Actinobacteria, Alpha-, Beta-, Gamma-Proteobacteria and Bacteroiedetes. No specific pattern linked to contamination was observed for these culturable bacteria. The results show that both highly and weakly contaminated soils host a wide diversity of bacteria, suggesting that long term exposure to radionuclides does not lead to the extinction of bacterial diversity. 4. Microbial diversity in contaminated soils along the T22 trench of the Chernobyl experimental platform International Nuclear Information System (INIS) Chapon, Virginie; Piette, Laurie; Vesvres, Marie-Hélène; Coppin, Frédéric; Marrec, Claire Le; Christen, Richard; Theodorakopoulos, Nicolas; Février, Laureline 2012-01-01 The diversity of bacterial communities exposed to radioactive contamination in Chernobyl soils was examined by a combination of molecular and culture-based approaches. A set of six radioactive soil samples, exhibiting high levels of 137 Cs contamination, were collected from the T22 trench. Three samples were also collected in nearby soils with low contamination. Complex bacterial community structures were observed in both highly and weakly contaminated samples, using a molecular approach targeting the 16S rRNA gene. However, the presence of specific populations within samples from highly contaminated soils could not be revealed by statistical analysis of the DGGE profiles. More than 200 culturable isolates, representative of dominant morphotypes, were grouped into 83 Operational Taxonomic Units (OTUs) and affiliated to Firmicutes, Actinobacteria, Alpha-, Beta-, Gamma-Proteobacteria and Bacteroïdetes. No specific pattern linked to contamination was observed for these culturable bacteria. The results show that both highly and weakly contaminated soils host a wide diversity of bacteria, suggesting that long term exposure to radionuclides does not lead to the extinction of bacterial diversity. 5. Some problems in calibrating surface contamination meters International Nuclear Information System (INIS) Chen Zigen; LI Xingyuan; Shuai Xiaoping. 1984-01-01 It is necessary that instruments are calibrated accurately in order to obtain reliable survey data of surface contamination. Some problems in calibrating surface contamination meters are expounded in this paper. Measurement comparison for beta surface contamination meters is organized within limited scope, thus survey quality is understood, questions are discovered, significance of calibration is expounded further. (Author) 6. Gamma Knife Science.gov (United States) ... News Physician Resources Professions Site Index A-Z Gamma Knife Gamma Knife® is a radiation therapy that uses computerized ... If you're scheduled for radiation therapy using Gamma Knife®, a treatment team consisting of a radiation ... 7. Determination of 210Pb by direct gamma-ray spectrometry, beta counting via 210Bi and alpha-particle spectrometry via 210Po in coal, slag and ash samples from thermal power plant International Nuclear Information System (INIS) Seslak, Bojan; Vukanac, Ivana; Kandic, Aleksandar; Durasevic, Mirjana; Eric, Milic; Jevremovic, Aleksandar 2017-01-01 In order to compare three different techniques and estimate radiological impact, activity concentration of 210 Pb in coal, slag and ash samples from thermal power plant 'Nikola Tesla', Serbia, were measured, and results are presented in this study. Determination of 210 Pb was carried out in three ways: using HPGe gamma spectrometer and via in-growth of 210 Po and 210 Bi by alpha-particle spectrometry and proportional counting, respectively. The results obtained for three different techniques were compared. Statistical analysis and comparison of methods were carried out by combination of Z score and χ 2 statistical tests. Tests results, as well as values of measured activities concentrations obtained by alpha and gamma spectrometry, showed that gamma spectrometry is a valid alternative to time-consuming alpha spectrometry for low level activity measurements of 210 Pb. This remark is also valid even for gamma spectrometers with poor efficiency in low energy region. (author) 8. SIMON: A mobile robot for floor contamination surveys International Nuclear Information System (INIS) Dudar, E.; Teese, G.; Wagner, D. 1991-01-01 The Robotics Development group at the Savannah River Site is developing an autonomous robot to perform radiological surveys of potentially contaminated floors. The robot scans floors at a speed of one-inch/second and stops, sounds an alarm, and flashes lights when contamination in a certain area is detected. The contamination of interest here is primarily alpha and beta-gamma. The contamination levels are low to moderate. The robot, a Cybermotion K2A, is radio controlled, uses dead reckoning to determine vehicle position, and docks with a charging station to replenish its batteries and calibrate its position. It has an ultrasonic collision avoidance system as well as two safety bumpers that will stop the robot's motion when they are depressed. Paths for the robot are preprogrammed and the robot's motion can be monitored on a remote screen which shows a graphical map of the environment. The radiation instrument being used is an Eberline RM22A monitor. This monitor is microcomputer based with a serial I/O interface for remote operation. Up to 30 detectors may be configured with the RM22A. For our purposes, two downward-facing gas proportional detectors are used to scan floors, and one upward-facing detector is used for radiation background compensation. SIMON is interfaced with the RM22A in such a way that it scans the floor surface at one-inch/second, and if contamination is detected, the vehicle stops, alarms, and activates a voice synthesizer. Future development includes using the contamination data collected to provide a graphical contour map of a contaminated area. 3 refs 9. In vivo effects of chronic contamination with 137 cesium on testicular and adrenal steroidogenesis Energy Technology Data Exchange (ETDEWEB) Grignard, Elise; Gueguen, Yann; Grison, Stephane; Gourmelon, Patrick; Souidi, Maamar [Institute for Radiological Protection and Nuclear Safety, Radiological Protection and Human Health Division, Radiobiology and Epidemiology Department, Laboratory of Experimental Toxicology, BP no 17, Fontenay-aux-Roses Cedex (France); Lobaccaro, Jean-Marc A. [UMR Universite Blaise Pascal-CNRS 6547, Physiologie Comparee et Endocrinologie Moleculaire, Centre de Recherche en Nutrition Humaine d' Auvergne, Aubiere Cedex (France) 2008-09-15 More than 20 years after Chernobyl nuclear power plant explosion, radionuclids are still mainly bound to the organic soil layers. The radiation exposure is dominated by the external exposure to gamma-radiation following the decay of {sup 137}Cs and by soil-to-plant-to-human transfer of {sup 137}Cs into the food chain. Because of this persistence of contamination with {sup 137}Cs, questions regarding public health for people living in contaminated areas were raised. We investigated the biological effects of chronic exposure to {sup 137}Cs on testicular and adrenal steroidogenesis metabolisms in rat. Animals were exposed to radionuclide in their drinking water for 9 months at a dose of 6,500 Bq/l (610 Bq/kg/day). Cesium contamination decreases the level of circulating 17{beta}-estradiol, and increases corticosterone level. In testis, several nuclear receptors messenger expression is disrupted; levels of mRNA encoding Liver X receptor {alpha} (LXR{alpha}) and LXR{beta} are increased, whereas farnesoid X receptor mRNA presents a lower level. Adrenal metabolism presents a paradoxical decrease in cyp11a1 gene expression. In conclusion, our results show for the first time molecular and hormonal modifications in testicular and adrenal steroidogenic metabolism, induced by chronic contamination with low doses of {sup 137}Cs. (orig.) 10. Medical effects of internal contamination with uranium. Science.gov (United States) Duraković, A 1999-03-01 The purpose of this work is to present an outline of the metabolic pathways of uranium isotopes and compounds, medical consequences of uranium poisoning, and an evaluation of the therapeutic alternatives in uranium internal contamination. The chemical toxicity of uranium has been recognized for more than two centuries. Animal experiments and human studies are conclusive about metabolic adverse affects and nephro- toxicity of uranium compounds. Radiation toxicity of uranium isotopes has been recognized since the beginning of the nuclear era, with well documented evidence of reproductive and developmental toxicity, as well as mutagenic and carcinogenic consequences of uranium internal contamination. Natural uranium (238U), an alpha emitter with a half-life of 4.5x10(9) years, is one of the primordial substances of the universe. It is found in the earth's crust, combined with 235U and 234U, alpha, beta, and gamma emitters with respective half-lives of 7.1x10(8) and 2.5x10(5) years. A special emphasis of this paper concerns depleted uranium. The legacy of radioactive waste, environmental and health hazards in the nuclear industry, and, more recently, the military use of depleted uranium in the tactical battlefield necessitates further insight into the toxicology of depleted uranium. The present controversy over the radiological and chemical toxicity of depleted uranium used in the Gulf War warrants further experimental and clinical investigations of its effects on the biosphere and human organisms. 11. Verification of radioactive contamination surveys for practical use in biological research centres International Nuclear Information System (INIS) Macias, M.T.; Requejo, C.; Ruiz, M.; Pina, R. 2006-01-01 Unsealed sources are commonly used in science research laboratories. Their manipulation may imply a radioactive contamination hazard. Therefore, adequate and sensitive survey meters must be available, and must have an effective and accurate response to intensity and type of radiation emitted by the used radionuclides to identify and quantify the possible contamination and then be able to avoid any associated or unwanted consequences that may arise. Periodic surveys are performed to show control, any time, any place radioactive contamination is suspected, and to ensure radioisotopes are being used safely. The immediate work areas must be often checked with portable survey monitors, including the entire lab and particularly bench tops, personnel protective equipment or solely designated equipment for isotope use (micro-fuges, water baths, incubators). These are carried out with portable survey instruments like Geiger-Muller tubes, proportional counters and scintillation detectors that provide direct or indirect measurements capabilities. The Radiation Safety Office (R.S.O.) as well as the radioactive compounds working laboratories at the Instituto de Inv. Biomedicas 'A. Sols' (Madrid-Spain) are provided with an adequate radiation measurement instrument. But, before a portable survey instrument is used, several quality checks should be made (batteries, calibration sticker), and the instrument response should be tested with a check source. This paper aims at determining, with a R.S.O. procedure, these surveys working parameters -detection efficiency, calibration factors and minimum detectable activities-, using reference checking sources ( 14 C, 36 Cl, and 90 Sr/ 90 Y) with known radioactivity covering the energy range of beta emitting isotopes used in biological research. No gamma portable monitors have been tested for the R.S.O. has no gamma checking sources. Therefore, 58 beta monitors were tested, obtaining t he efficiency values, the calibration factors (Bq cm-2 s 12. Beta decay of 22O International Nuclear Information System (INIS) Hubert, F.; Dufour, J.P.; Del Moral, R.; Fleury, A.; Jean, D.; Pravikoff, M.S.; Geissel, H.; Schmidt, K.H.; Hanelt, E. 1989-01-01 The study of light nuclei far from stability has been recently renewed by the possibility of production through the projectile fragmentation of intermediate energy heavy ion beams at GANIL. The results presented here have been obtained with the Projectile Fragments Isotopic Separation method developed at the LISE spectrometer. 22 O is a Tz = 3 nucleus and is the first in a series of seven such nuclei in the sd shell extending from 22 O to 24 Mg. Although the half life of 22 O was previously measured by Murphy et al., the present study is the first beta-gamma spectroscopy on this neutron rich nucleus. Five gamma lines have been attributed to the β decay of 22 O with a measured half life of T = (2.25±0.15)s and a partial decay scheme has been established 13. Field measurement and interpretation of beta doses and dose rates International Nuclear Information System (INIS) Selby, J.M.; Swinth, K.L.; Hooker, C.D.; Kenoyer, J.L. 1983-01-01 A large number of portable survey instruments employing G.M., ionization chamber, and scintillation detectors used for gamma measurements are also used for monitoring in beta fields by using removable shields to separate the beta and gamma components of the radiation field. The difference does not correspond to an absorbed dose rate for the beta field due to a variety of factors. Among these factors are the dependence on beta energy, source-detector geometries, mixed fields and variable ambient conditions. Attempting to use such measurements directly can lead to errors as high as a factor of 100. Appropriate calibrations and correction factors can be used to reduce the errors in beta measurements to a tolerable level 14. Position-sensitive radiation monitoring (surface contamination monitor). Innovative technology summary report International Nuclear Information System (INIS) 1999-06-01 The Shonka Research Associates, Inc. Position-Sensitive Radiation Monitor both detects surface radiation and prepares electronic survey map/survey report of surveyed area automatically. The electronically recorded map can be downloaded to a personal computer for review and a map/report can be generated for inclusion in work packages. Switching from beta-gamma detection to alpha detection is relatively simple and entails moving a switch position to alpha and adjusting the voltage level to an alpha detection level. No field calibration is required when switching from beta-gamma to alpha detection. The system can be used for free-release surveys because it meets the federal detection level sensitivity limits requires for surface survey instrumentation. This technology is superior to traditionally-used floor contamination monitor (FCM) and hand-held survey instrumentation because it can precisely register locations of radioactivity and accurately correlate contamination levels to specific locations. Additionally, it can collect and store continuous radiological data in database format, which can be used to produce real-time imagery as well as automated graphics of survey data. Its flexible design can accommodate a variety of detectors. The cost of the innovative technology is 13% to 57% lower than traditional methods. This technology is suited for radiological surveys of flat surfaces at US Department of Energy (DOE) nuclear facility decontamination and decommissioning (D and D) sites or similar public or commercial sites 15. Position-sensitive radiation monitoring (surface contamination monitor). Innovative technology summary report Energy Technology Data Exchange (ETDEWEB) 1999-06-01 The Shonka Research Associates, Inc. Position-Sensitive Radiation Monitor both detects surface radiation and prepares electronic survey map/survey report of surveyed area automatically. The electronically recorded map can be downloaded to a personal computer for review and a map/report can be generated for inclusion in work packages. Switching from beta-gamma detection to alpha detection is relatively simple and entails moving a switch position to alpha and adjusting the voltage level to an alpha detection level. No field calibration is required when switching from beta-gamma to alpha detection. The system can be used for free-release surveys because it meets the federal detection level sensitivity limits requires for surface survey instrumentation. This technology is superior to traditionally-used floor contamination monitor (FCM) and hand-held survey instrumentation because it can precisely register locations of radioactivity and accurately correlate contamination levels to specific locations. Additionally, it can collect and store continuous radiological data in database format, which can be used to produce real-time imagery as well as automated graphics of survey data. Its flexible design can accommodate a variety of detectors. The cost of the innovative technology is 13% to 57% lower than traditional methods. This technology is suited for radiological surveys of flat surfaces at US Department of Energy (DOE) nuclear facility decontamination and decommissioning (D and D) sites or similar public or commercial sites. 16. Immobilisation of alpha contaminated lubricating oils in cement matrix International Nuclear Information System (INIS) Manohar, Smitha; Sathi Sasidharan, N.; Wattal, P.K.; Shah, N.J.; Chander, Mahesh; Bansal, N.K. 2000-10-01 Alpha contaminated lubricating oil wastes are generated from the reprocessing plants and other alpha handling facilities. Incineration of these spent lubricating oils requires specially designed facility to handle the aerosols of actinide oxides released to the off-gases. Hence immobilisation of these wastes into cement matrix could be a viable alternative. Work was therefore initiated to examine the possibility of immobilising such waste in cement matrix with the help of suitable additives. This work led to the selection of sodium hydroxide and silica fumes as additives for their distinct role in immobilization of such waste in cement. The selected formulation was tested extensively both on laboratory scale and full scale for acceptable waste form. The leach test on laboratory scale indicated negligible release of alpha and beta gamma activity after 180 days. This report gives a brief on the formulation of the admixture and its effect on the immobilization of waste. (author) 17. Development of custom LCD based portable survey/contamination monitors International Nuclear Information System (INIS) Reddy, J.D. 2010-01-01 Equipments for carrying out radiation survey measurements for alpha, beta and gamma radiations have evolved considerably with the advancements in Electronics overtime. There are 2 major classes of portable instruments available from most manufacturers - (a) Analog indicator type (b) Direct digital readout type. Analog meters give a direct quantifying feel to radiation levels though they are not rich features nor they have smartness like a digital meter. Digital versions have advantages of direct readout numerically and configurable as per users requirements. To achieve best features of both the techniques a dual indicator type LCD module comprising of Analog indicating LCD segments and digital readout indicating 7 segments has been developed. This LCD comprising of LCD glass and its display driver has been deployed across various types of survey meters and contamination monitors manufactured by Nucleonix. This display now facilitates direct readout of dose rate/count rate in various units simultaneously in both analog LCD scale and direct digital indication. (author) 18. Reconstruction of local fallout composition and gamma-ray exposure in a village contaminated by the first USSR nuclear test in the Semipalatinsk nuclear test site in Kazakhstan. Science.gov (United States) Imanaka, Tetsuji; Yamamoto, Masayoshi; Kawai, Kenta; Sakaguchi, Aya; Hoshi, Masaharu; Chaizhunusova, Nailya; Apsalikov, Kazbek 2010-11-01 After the disintegration of the USSR in end of 1991, it became possible for foreign scientists to visit Kazakhstan, in order to investigate the radiological consequences of nuclear explosions that had been conducted at the Semipalatinsk nuclear test site (SNTS). Since the first visit in 1994, our group has been continuing expeditions for soil sampling at various areas around SNTS. The current level of local fallout at SNTS was studied through γ-spectrometry for (137)Cs as well as α-spectrometry for (239,240)Pu. Average values of soil inventory from wide areas around SNTS were 3,500 and 3,700 Bq m(-2) for (137)Cs and (239,240)Pu, respectively, as of January 1, 2000. The average level of (137)Cs is comparable to that in Japan due to global fallout, while the level of (239,240)Pu is several tens of times larger than that in Japan. Areas of strong contamination were found along the trajectories of radioactive fallout, information on which was declassified after the collapse of the USSR. Our recent efforts of soil sampling were concentrated on the area around the Dolon village heavily affected by the radioactive plume from the first USSR atomic bomb test in 1949 and located 110 km east from ground zero of the explosion. Using soil inventory data, retrospective dosimetry was attempted by reconstructing γ-ray exposure from fission product nuclides deposited on the ground. Adopting representative parameters for the initial (137)Cs deposition (13 kBq m(-2)), the refractory/volatile deposition ratio (3.8) and the plume arrival time after explosion (2.5 h), an absorbed dose in air of 600 mGy was obtained for the 1-year cumulative dose in Dolon village, due to the first bomb test in 1949. Considering possible ranges of the parameters, 350 and 910 mGy were estimated for high and low cases of γ-ray dose in air, respectively. It was encouraging that the deduced value was consistent with other estimations using thermal luminescence and archived monitoring data. The present 19. L{sub {iota}}, L{sub {alpha}}, L{sub {beta}} and L{sub {gamma}} X-ray fluorescence cross-sections of heavy elements for the exciting photons energy 38.18, 43.95, 50.21 and 59.5 keV Energy Technology Data Exchange (ETDEWEB) Bastug, Arif [Department of Physics Education, College of Education, Erzincan University, 24030 Erzincan (Turkey)], E-mail: abastug40@hotmail.com 2008-03-15 The cross-sections for the production of L{sub {iota}}, L{sub {alpha}}, L{sub {beta}} and L{sub {gamma}} X-ray fluorescence (XRF) in Er, Ta, W, Au, Hg, Tl, Pb and Bi by photons with energies in the range 38-59.5 keV have been measured, using a standard doublereflection experimental set-up. Measurements have been performed using an annular 241 Am primary source and X-ray emitting secondary-exciter system. Experimental cross-sections have been compared with the theoretically calculated values of L X-ray cross-sections and fairly good agreement is observed between the experimental and theoretical values. 20. Distribution pathways of hexachlorocyclohexane isomers in a soil-plant-air system. A case study with Cynara scolymus L. and Erica sp. plants grown in a contaminated site. Science.gov (United States) Pereira, R Calvelo; Monterroso, C; Macías, F; Camps-Arbestain, M 2008-09-01 This study focuses on the main routes of distribution and accumulation of different hexachlorocyclohexane (HCH) isomers (mainly alpha-, beta-, gamma- and delta-HCH) in a soil-plant-air system. A field assay was carried out with two plant species, Cynara scolymus L. and Erica sp., which were planted either: (i) directly in the HCH-contaminated soil; or (ii) in pots filled with uncontaminated soil, which were placed in the HCH-contaminated soil. Both plant species accumulated HCH in their tissues, with relatively higher accumulation in above-ground biomass than in roots. The beta-HCH isomer was the main isomer in all plant tissues. Adsorption of HCH by the roots from contaminated soil (soil-->root pathway) and adsorption through the aerial biomass from either the surrounding air, following volatilization of the contaminant (soil-->air-->shoot pathway), and/or contact with air-suspended particles contaminated with HCH (soil particles-->shoot pathway) were the main mechanisms of accumulation. These results may have important implications for the use of plants for reducing the transfer of contaminants via the atmosphere. 1. Beta Emission and Bremsstrahlung Energy Technology Data Exchange (ETDEWEB) Karpius, Peter Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States) 2017-11-13 Bremsstrahlung is continuous radiation produced by beta particles decelerating in matter; different beta emitters have different endpoint energies; high-energy betas interacting with high-Z materials will more likely produce bremsstrahlung; depending on the data, sometimes all you can say is that a beta emitter is present. 2. Beta-decay of {sup 103}In: evidence for the Gamow-Teller resonance near {sup 100}Sn Energy Technology Data Exchange (ETDEWEB) Karny, M. [Warsaw Univ. (Poland). Inst. of Experimental Physics; Batist, L.; Brown, B.A. [and others 1998-04-01 The {beta} decay of the neutron-deficient isotope {sup 103}In was investigated by using total absorption {gamma}-ray spectrometry on mass-separated sources. The measurement reveals a high-lying resonance of the {beta}-decay strength in striking disagreement with high-resolution {gamma}-ray data. The result is discussed in comparison with shell-model predictions. (orig.) 3. Fast-timing studies of nuclei below$^{68}$Ni populated in the$\\beta$-decay of Mn isotopes CERN Multimedia Jokinen, A; Simpson, G S; Garcia borge, M J; Koester, U H; Georgiev, G P; Fraile prieto, L M; Aprahamian, A 2008-01-01 We intend to investigate structure of nuclei populated in the$\\beta$-decay of Mn isotopes via the ATD$\\beta\\gamma\\gamma$(t) technique. With this method we will measure dynamic moments in Fe isotopes and their daughters in order to characterize the role of particle-hole excitation across the${N}\$=40 sub-shell closure and the development of collectivity.
4. Verification of surface contamination density standard using clearance automatic laser inspection system for objects from a nuclear power plant
International Nuclear Information System (INIS)
Sasaki, Michiya; Ogino, Haruyuki; Ichiji, Takeshi; Hattori, Takatoshi
2008-01-01
In the clearance level inspection in Japan, it is necessary to indicate that the activity level of the target object must be less than not only the clearance levels, but also the surface contamination density standards. The classification measurements for these two standards have been performed separately, and the GM survey meters based on beta-ray measurement have mainly been used for surface contamination density measurement so far. Recently the Clearance Automatic Laser Inspection System, named CLALIS, has been developed to estimate the low-level activity concentration. This system consists of 3-dimensional laser scanner for shape measurement and eight large NE102A plastic scintillation detectors for gamma-ray measurement, and it has been clarified that the CLALIS has adequate detection ability for clearance measurement of both metal scraps and concrete debris. In this study, we compared the surface contamination densities for a number of actual contaminated and non-contaminated objects generated inside from the radiation controlled area at the Kashiwazaki-Kariwa nuclear power station by using the CLALIS and the GM survey meter. As a result, since CLALIS could detect the surface contamination as well as the GM survey meter for all measurement targets, it was revealed that CLALIS can rationally achieve clearance level inspection in a single radiation measurement. The practicality of CLALIS in view of the detection limit and processing time was discussed by comparison with the usual radiation monitors for surface contamination measurement. (author)
5. Simulated progress in double-beta decay
International Nuclear Information System (INIS)
Miley, H.S.; Arthur, R.J.; Avignone, F.T.
1993-09-01
A Monte Carlo code has been developed to accurately simulate double-beta decay measurements. Coincident gamma rays, beta spectra, and angular correlations have been added to adequately simulate a complete 100 Mo nuclear decay and provide corrections to experimentally determined detector efficiencies. This code has been used to strip certain low-background spectra obtained in the Homestake gold mine in Lead, SD, for the purpose of extremely sensitive materials assay for the construction of new, large, enriched germanium detectors. Assays as low as 9 μBq/g of 210 Pb in lead shielding were obtained
6. Early continuous white noise exposure alters l-alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor subunit glutamate receptor 2 and gamma-aminobutyric acid type a receptor subunit beta3 protein expression in rat auditory cortex.
Science.gov (United States)
Xu, Jinghong; Yu, Liping; Zhang, Jiping; Cai, Rui; Sun, Xinde
2010-02-15
Auditory experience during the postnatal critical period is essential for the normal maturation of auditory function. Previous studies have shown that rearing infant rat pups under conditions of continuous moderate-level noise delayed the emergence of adult-like topographic representational order and the refinement of response selectivity in the primary auditory cortex (A1) beyond normal developmental benchmarks and indefinitely blocked the closure of a brief, critical-period window. To gain insight into the molecular mechanisms of these physiological changes after noise rearing, we studied expression of the AMPA receptor subunit GluR2 and GABA(A) receptor subunit beta3 in the auditory cortex after noise rearing. Our results show that continuous moderate-level noise rearing during the early stages of development decreases the expression levels of GluR2 and GABA(A)beta3. Furthermore, noise rearing also induced a significant decrease in the level of GABA(A) receptors relative to AMPA receptors. However, in adult rats, noise rearing did not have significant effects on GluR2 and GABA(A)beta3 expression or the ratio between the two units. These changes could have a role in the cellular mechanisms involved in the delayed maturation of auditory receptive field structure and topographic organization of A1 after noise rearing. Copyright 2009 Wiley-Liss, Inc.
7. Beta-secretase-cleaved amyloid precursor protein in Alzheimer brain: a morphologic study
DEFF Research Database (Denmark)
Sennvik, Kristina; Bogdanovic, N; Volkmann, Inga
2004-01-01
beta-amyloid (Abeta) is the main constituent of senile plaques seen in Alzheimer's disease. Abeta is derived from the amyloid precursor protein (APP) via proteolytic cleavage by proteases beta- and gamma-secretase. In this study, we examined content and localization of beta-secretase-cleaved APP...... the beta-sAPP immunostaining to be stronger and more extensive in gray matter in Alzheimer disease (AD) cases than controls. The axonal beta-sAPP staining was patchy and unevenly distributed for the AD cases, indicating impaired axonal transport. beta-sAPP was also found surrounding senile plaques...
8. Malarial pigment haemozoin, IFN-gamma, TNF-alpha, IL-1beta and LPS do not stimulate expression of inducible nitric oxide synthase and production of nitric oxide in immuno-purified human monocytes
Directory of Open Access Journals (Sweden)
Ceretto Monica
2007-06-01
Full Text Available Abstract Background Enhanced production of nitric oxide (NO following upmodulation of the inducible isoform of NO synthase (iNOS by haemozoin (HZ, inflammatory cytokines and LPS may provide protection against Plasmodium falciparum malaria by killing hepatic and blood forms of parasites and inhibiting the cytoadherence of parasitized erythrocytes (RBC to endothelial cells. Monocytes and macrophages are considered to contribute importantly to protective upregulation of iNOS and production of NO. Data obtained with murine phagocytes fed with human HZ and synthetic HZ (sHZ indicate that supplemental treatment of those cells with IFN-gamma elicited significant increases in protein and mRNA expression of iNOS and NO production, providing a potential mechanism linking HZ phagocytosis and increased production of NO. Purpose of this study was to analyse the effect of P. falciparum HZ and sHZ supplemental to treatment with IFN-gamma and/or a stimulatory cytokine-LPS mix on iNOS protein and mRNA expression in immuno-purified human monocytes. Methods Adherent immunopurified human monocytes (purity >85%, and murine phagocytic cell lines RAW 264.7, N11 and ANA1 were fed or not with P. falciparum HZ or sHZ and treated or not with IFN-gamma or a stimulatory cytokine-LPS mix. Production of NO was quantified in supernatants, iNOS protein and mRNA expression were measured after immunoprecipitation and Western blotting and quantitative RT-PCT, respectively. Results Phagocytosis of HZ/sHZ by human monocytes did not increase iNOS protein and mRNA expression and NO production either after stimulation by IFN-gamma or the cytokine-LPS mix. By contrast, in HZ/sHZ-laden murine macrophages, identical treatment with IFN-gamma and the cytokine-LPS mix elicited significant increases in protein and mRNA expression of iNOS and NOS metabolites production, in agreement with literature data. Conclusion Results indicate that human monocytes fed or not with HZ/sHZ were constantly
9. Atmospheric contamination
International Nuclear Information System (INIS)
Gruetter, Juerg
1997-01-01
It is about the levels of contamination in center America, the population's perception on the problem, effects of the atmospheric contamination, effects in the environment, causes of the atmospheric contamination, possibilities to reduce the atmospheric contamination and list of Roeco Swisscontac in atmospheric contamination
10. In-trap decay spectroscopy for {beta}{beta} decays
Energy Technology Data Exchange (ETDEWEB)
Brunner, Thomas
2011-01-18
The presented work describes the implementation of a new technique to measure electron-capture (EC) branching ratios (BRs) of intermediate nuclei in {beta}{beta} decays. This technique has been developed at TRIUMF in Vancouver, Canada. It facilitates one of TRIUMF's Ion Traps for Atomic and Nuclear science (TITAN), the Electron Beam Ion Trap (EBIT) that is used as a spectroscopy Penning trap. Radioactive ions, produced at the radioactive isotope facility ISAC, are injected and stored in the spectroscopy Penning trap while their decays are observed. A key feature of this technique is the use of a strong magnetic field, required for trapping. It radially confines electrons from {beta} decays along the trap axis while X-rays, following an EC, are emitted isotropically. This provides spatial separation of X-ray and {beta} detection with almost no {beta}-induced background at the X-ray detector, allowing weak EC branches to be measured. Furthermore, the combination of several traps allows one to isobarically clean the sample prior to the in-trap decay spectroscopy measurement. This technique has been developed to measure ECBRs of transition nuclei in {beta}{beta} decays. Detailed knowledge of these electron capture branches is crucial for a better understanding of the underlying nuclear physics in {beta}{beta} decays. These branches are typically of the order of 10{sup -5} and therefore difficult to measure. Conventional measurements suffer from isobaric contamination and a dominating {beta} background at theX-ray detector. Additionally, X-rays are attenuated by the material where the radioactive sample is implanted. To overcome these limitations, the technique of in-trap decay spectroscopy has been developed. In this work, the EBIT was connected to the TITAN beam line and has been commissioned. Using the developed beam diagnostics, ions were injected into the Penning trap and systematic studies on injection and storage optimization were performed. Furthermore, Ge
Energy Technology Data Exchange (ETDEWEB)
Curie, I
1948-12-08
Following the work of Ward (Proc Cambridge Phil Soc 35 322(1939)), the ..gamma..-radiation of ionium (from an IoTh preparation) was studied with the aid of Ta and W screens, and an aluminum counter. The screen measurements confirmed Ward's findings of two radiations, of 68 keV and of about 200 keV. The number of quanta per second of each radiation was determined with the counter, which has been calibrated on certain L lines of radium. The global quanta number of L lines of ionium was also determined. The results were as follows: 0.7 quanta ..gamma.. of 68 keV for 100 ..cap alpha..-particles; 0.2 quanta ..gamma.. of 200 keV for 100 ..cap alpha..-particles; 10 quanta L for 100 ..cap alpha..-particles. These data, which show an important internal conversion, agree with the findings of Teillac (Compt Rend 227 1227 (1948)), who investigated the ..beta..-radiation of ionium. It is the radiation 68 keV which is highly converted. On the other hand, these results do no agree with the data on the fine structure of ionium found by Rosenblum, Valadares, and Vial (Compt Rend 227 1088(1948)).
12. Evolution of bacterial community during bioremediation of PAHs in a coal tar contaminated soil
Energy Technology Data Exchange (ETDEWEB)
Lors, C.; Ryngaert, A.; Perie, F.; Diels, L.; Damidot, D. [University of Lille, Lille (France)
2010-11-15
The monitoring of a windrow treatment applied to soil contaminated by mostly 2, 3- and 4-ring PAHs produced by coal tar distillation was performed by following the evolution of both PAH concentration and the bacterial community. Total and PAH-degrading bacterial community structures were followed by 165 rRNA PCR-DGGE in parallel with quantification by bacterial counts and 16 PAH measurements. Six months of biological treatment led to a strong decrease in 2-, 3- and 4-ring PAH concentrations (98, 97 and 82%, respectively). This result was associated with the activity of bacterial PAH-degraders belonging mainly to the Gamma proteobacteria, in particular the Enterobacteria and Pseudomonas genera which were detected over the course of the treatment. This group was considered to be a good bioindicator to determine the potential PAH biodegradation of contaminated soil. Conversely other species like the Beta proteobacteria were detected after 3 months when 2-, 3- and 4-ring PAHs were almost completely degraded. Thus presence of the Beta proteobacteria group could be considered a good candidate indicator to estimate the endpoint of biotreatment of this type of PAH contaminated soil.
13. Effect of gamma radiation on optical and electrical properties of ...
Wintec
Tellurium dioxide; thin films; optical bandgap; gamma radiation dose; dosimeter. 1. Introduction. It is now ... material to ionizing radiations (such as X-rays, gamma rays, beta ..... Mag. 19 19. Mott N F and Davis E 1979 Electronic process in non-.
14. Analysis of Radioactivity Contamination Level of Kartini Reactor Efluen Gas to the Environment
International Nuclear Information System (INIS)
Suratman; Purwanto; Aminjoyo, S
1996-01-01
The analysis of radioactivity contamination level of Kartini reactor efluen gas to the environment has been done from 13-10-'95 until 8-2-'96. The aim of this research is to determine the radioactivity contamination level on the environment resulted from the release of Kartini reactor efluen gas and other facilities at Yogyakarta Nuclear Research Centre through stack. The analysis methods is the student t-test, the first count factor test and the gamma spectrometry. The gas sampling were carried out in the stack reactor, reactor room, environment and in other room for comparison. Efluen gas was sucked through a filter by a high volume vacuum pump. The filter was counted for beta, gamma and alpha activities. The radioactivity contamination level of the efluen gas passing through the stack to the environment was measured between 0.57 - 1.34 Bq/m3, which was equal to the airborne radioactivity in environment between 0.69 - 1.12 Bq/m3. This radioactivity comes from radon daughter, decay products result from the natural uranium and thorium series of the materials of the building
15. Suppressor of cytokine signalling (SOCS)-3 protects beta cells against IL-1beta-mediated toxicity through inhibition of multiple nuclear factor-kappaB-regulated proapoptotic pathways
DEFF Research Database (Denmark)
Karlsen, Allan Ertman; Heding, P E; Frobøse, H
2004-01-01
The proinflammatory cytokine IL-1beta induces apoptosis in pancreatic beta cells via pathways dependent on nuclear factor-kappaB (NF-kappaB), mitogen-activated protein kinase, and protein kinase C. We recently showed suppressor of cytokine signalling (SOCS)-3 to be a natural negative feedback reg...... regulator of IL-1beta- and IFN-gamma-mediated signalling in rat islets and beta cell lines, preventing their deleterious effects. However, the mechanisms underlying SOCS-3 inhibition of IL-1beta signalling and prevention against apoptosis remain unknown....
16. Gamma astronomy
International Nuclear Information System (INIS)
Cesarsky, C.; Cesarsky, J.P.
1986-01-01
This article overviews the gamma astronomy research. Sources already observed, and what causes to give to them; the galactic radiation and its interpretation; techniques already used and current projects [fr
17. Gamma Spectroscopy
NARCIS (Netherlands)
Niemantsverdriet, J.W.; Butz, Tilman; Ertl, G.; Knözinger, H.; Schüth, F.
2008-01-01
No abstract. The sections in this article are 1 Introduction 2 Mössbauer Spectroscopy 3 Time-Differential Perturbed Angular Correlations (TDPAC) 4 Conclusions and Outlook Keywords: Mössbauer spectroscopy; gamma spectroscopy; perturbed angular correlation; TDPAC
18. Application of invariant plane strain (IPS) theory to {gamma} hydride formation in dilute Zr-Nb alloys
Energy Technology Data Exchange (ETDEWEB)
Srivastava, D. [Materials Science Division, Bhabha Atomic Research Centre, Mumbai 400085, Maharashtra (India)]. E-mail: dsrivastavabarc@yahoo.co.in; Neogy, S. [Materials Science Division, Bhabha Atomic Research Centre, Mumbai 400085, Maharashtra (India); Dey, G.K. [Materials Science Division, Bhabha Atomic Research Centre, Mumbai 400085, Maharashtra (India); Banerjee, S. [Materials Science Division, Bhabha Atomic Research Centre, Mumbai 400085, Maharashtra (India); Ranganathan, S. [Materials Science Division, Bhabha Atomic Research Centre, Mumbai 400085, Maharashtra (India)
2005-04-25
The crystallographic aspects associated with the formation of the {gamma} hydride phase (fct) from the {alpha} (hcp) phase and the {beta} (bcc) phase in Zr-Nb alloys have been studied in two distinct situations, viz., in the {alpha} matrix in pure Zr and Zr-2.5Nb and in the {beta} matrix in {beta} stabilized Zr-20Nb alloy. The {beta}-{gamma} formation can be treated primarily as a simple shear on the basal plane involving a change in the stacking sequence. A possible mechanism for {alpha}-{gamma} transformation has been presented in this paper. In this paper the {beta}->{gamma} transformation has been considered in terms of the invariant plane strain theory (IPS) in order to predict the crystallographic features of the {gamma} hydride formed. The lattice invariant shear (LIS) (110){sub {beta}}[1-bar 10]{sub {beta}}||(111){sub {gamma}}[12-bar 1]{sub {gamma}} has been considered and the crystallographic parameters associated with bcc->fct transformation, such as the habit plane and the magnitude of the LIS and the shape strain have been computed. The predictions made in the present analysis have been compared with experimentally observed habit planes. The {alpha}/{gamma} and {beta}/{gamma} interface has been examined by high resolution transmission electron microscopy (HRTEM) technique to compare with the interfaces observed in martensitic transformations.
19. Beta decay to the second 2+ excited state of 122Te
International Nuclear Information System (INIS)
1976-01-01
The first-forbidden beta transition in Sb-122 was studied by the angular correlation experiment and the beta-spectra. The special precautions were paid for counting the beta particles having energy lower than 750 keV in the beta-gamma angular correlation measurement. The sources of Sb-122 were obtained by irradiating enriched Sb-121 in the Kyoto University reactor. The reduced beta coefficient R(E) was obtained from the angular correlation function. The beta spectrum measurement was performed with a sector type double focusing beta-ray spectrometer. The R(E) values for the beta transitions were analyzed by using the simplex method as used by Manthuruthil and Poirier to compare the angular correlation data with the exact formula given by Morita and Morita. Sets of the nuclear matrix parameters thus obtained show that the condition for the cancellation effect is satisfied in the beta transition. (Kato, T.)
20. Contamination levels observed on the Belgian territory subsequent to the Chernobyl accident
Energy Technology Data Exchange (ETDEWEB)
Hoof, J van [State University of Ghent, Faculty of Veterinary Medicine, Gent (Belgium); Maghuin-Rogister, G [Universite de Liege, Brussels (Belgium)
1986-07-01
Contaminated air masses reached the Belgian territory from the South during the night of the first to the second of May. At this stage however the origin of this contamination was already identified through earlier observations over the Scandinavian area and the subsequent message about the reactor accident at the Chernobyl site. Later on radioactive clouds were also detected over the central part of Europe, demonstrating the persistent nature of the emissions from the damaged reactor. Consequently the influence on the Belgian territory was not unexpected. The authorities called on the SCK/CEN at Mol, and the IRE at Fleurus to assist the IHE at Brussels in collecting the necessary data for judging the radiological situation in our country. The KMI/IRM at Brussels was involved for the follow-up of meteorological conditions and analysis of the trajectories of contaminated air masses. Early detection possibilities for the arrival of contaminated air were provided by the continuous environmental monitoring apparatus for ambient {gamma}-dose rate or for {beta} activity of airborne dust, available at nuclear institutions and nuclear power plants. On detection of enhanced air radioactivity, the sampling period of routine air dust samplers was significantly shortened to allow for the hour to hour renewal of data for gross {beta} activity as a general indication of the evolution of the air contamination. {gamma}-spectrometric analysis of those filters provided the necessary data for the estimation of the dose equivalent due to inhalation. Ground deposition data at the location of the participating institutions were obtained by daily analysis of the radioactivity contents of a water container collecting both dust and rainwater. Field gamma spectrometry was used later on at a number of other locations, to estimate the integrated ground deposition of radioactivity and its distribution over the country. As the grazing season was just started or was about to be started in the
1. The iron waste from thermal power plant (t.p.p.) as the source of radioactive contamination
International Nuclear Information System (INIS)
Kovacevic, M.; Todorovic, D.; Radenkovic, M.; Joksic, J.; Vukcevic, M.
2006-01-01
2. Radiação gama na redução da carga microbiana de filés de frango Gamma radiation on reduction of the microbial contamination of chicken steaks
Directory of Open Access Journals (Sweden)
Marta Helena Filet SPOTO
1999-12-01
3. Partitioning diversity into independent alpha and beta components.
Science.gov (United States)
Jost, Lou
2007-10-01
Existing general definitions of beta diversity often produce a beta with a hidden dependence on alpha. Such a beta cannot be used to compare regions that differ in alpha diversity. To avoid misinterpretation, existing definitions of alpha and beta must be replaced by a definition that partitions diversity into independent alpha and beta components. Such a unique definition is derived here. When these new alpha and beta components are transformed into their numbers equivalents (effective numbers of elements), Whittaker's multiplicative law (alpha x beta = gamma) is necessarily true for all indices. The new beta gives the effective number of distinct communities. The most popular similarity and overlap measures of ecology (Jaccard, Sorensen, Horn, and Morisita-Horn indices) are monotonic transformations of the new beta diversity. Shannon measures follow deductively from this formalism and do not need to be borrowed from information theory; they are shown to be the only standard diversity measures which can be decomposed into meaningful independent alpha and beta components when community weights are unequal.
4. Levered and unlevered Beta
OpenAIRE
Fernandez, Pablo
2003-01-01
We prove that in a world without leverage cost the relationship between the levered beta ( L) and the unlevered beta ( u) is the No-costs-of-leverage formula: L = u + ( u - d) D (1 - T) / E. We also analyze 6 alternative valuation theories proposed in the literature to estimate the relationship between the levered beta and the unlevered beta (Harris and Pringle (1985), Modigliani and Miller (1963), Damodaran (1994), Myers (1974), Miles and Ezzell (1980), and practitioners) and prove that all ...
5. Persistent organohalogen contaminants in plasma from groups of humans with different occupations in Bangladesh.
Science.gov (United States)
Zamir, R; Athanasiadou, M; Nahar, N; Mamun, M I R; Mosihuzzaman, M; Bergman, A
2009-01-01
The present study is aimed to assess persistent organic halogenated pollutants in humans living in Bangladesh. The results are compared to other similar studies in the region and globally. Human blood plasma were collected from groups of men and women with different occupations, i.e. being students, garment industry workers, employees at the Power Development Board (PDB), all groups in Dhaka, fishermen and fishermen wife's from Dhaka and another group from Barisal district. The plasma was analysed for hexachlorobenzene (HCB), the hexachlorocyclohexane isomers, alpha-HCH, beta-HCH, gamma-HCH and delta-HCH, the DDT group of chemicals, chlordane compounds, trans-chlordane, cis-chlordane, oxychlordane, trans-nonachlor, trans-heptachlorepoxide, methoxychlor and mirex. The most abundant contaminant, in all groups studied, p,p'-DDE is dominating, with p,p'-DDT/Sigma DDT ratios indicating recent and ongoing DDT exposure. Among the other pesticides analysed beta-HCH is the most abundant indicating the use of technical HCH products instead of Lindane (gamma-HCH). While the Sigma DDT is present in the low ppm range the beta-HCH is detected in up to approx. 400 ppb, lipid basis. The beta-HCH is most abundant in the groups of students. In contrast to the pesticides analysed very low concentrations of polychlorinated biphenyls (PCB) are present in all study groups, with e.g. CB-153 in the range of 5-30 ng g(-1) fat. The concentrations of the DDT group of chemical differ significantly between fishermen and fishermen's wives living and working in the Dhaka area versus those living and working in Barisal. Also, fishermen and their wives had significantly different concentrations of DDT compared to garment industry workers.
6. Beta Thalassemia (For Parents)
Science.gov (United States)
... Safe Videos for Educators Search English Español Beta Thalassemia KidsHealth / For Parents / Beta Thalassemia What's in this ... Symptoms Diagnosis Treatment Print en español Beta talasemia Thalassemias Thalassemias are a group of blood disorders that ...
7. Abnormal ''Contamination' Levels On Garden Appliances
International Nuclear Information System (INIS)
German, U.; Levinson, S.; Elmelech, V.; Pelled, O.; Tshuva, A.; Laichter, Y.
1999-01-01
During routine contamination checks we encountered an abnormal high level of Alpha and Beta emitting radioisotopes on working gloves of employees of the gardening department. It came out that the source was due to ''contamination'' levels on steering wheels of some gardening machines. In order to ensure that no real contamination of these workers was involved , a series of checks was started to identity the source of the abnormal levels found during monitoring
8. Sources of radioactive contamination inside houses
International Nuclear Information System (INIS)
Sajet, A.S.
2010-01-01
9. Radiological, physical, and chemical characterization of low-level alpha contaminated wastes stored at the Idaho National Engineering Laboratory
International Nuclear Information System (INIS)
Apel, M.L.; Becker, G.K.; Ragan, Z.K.; Frasure, J.; Raivo, B.D.; Gale, L.G.; Pace, D.P.
1994-03-01
This document provides radiological, physical, and chemical characterization data for low-level alpha-contaminated radioactive and low-level alpha-contaminated radioactive and hazardous (i.e., mixed) wastes stored at the Idaho National Engineering Laboratory and considered for treatment under the Private Sector Participation Initiative Program. Waste characterization data are provided in the form of INEL Waste Profile Sheets. These documents provide, for each content code, information on waste identification, waste description, waste storage configuration, physical/chemical waste composition, radionuclide and associated alpha activity waste characterization data, and hazardous constituents present in the waste. Information is provided for 97 waste streams which represent an estimated total volume of 25,450 m 3 corresponding to a total mass of approximately 12,000,000 kg. In addition, considerable information concerning alpha, beta, gamma, and neutron source term data specific to Rocky Flats-generated waste forms stored at the INEL are provided to assist in facility design specification
10. Radiological, physical, and chemical characterization of low-level alpha contaminated wastes stored at the Idaho National Engineering Laboratory
Energy Technology Data Exchange (ETDEWEB)
Apel, M.L.; Becker, G.K.; Ragan, Z.K.; Frasure, J.; Raivo, B.D.; Gale, L.G.; Pace, D.P.
1994-03-01
This document provides radiological, physical, and chemical characterization data for low-level alpha-contaminated radioactive and low-level alpha-contaminated radioactive and hazardous (i.e., mixed) wastes stored at the Idaho National Engineering Laboratory and considered for treatment under the Private Sector Participation Initiative Program. Waste characterization data are provided in the form of INEL Waste Profile Sheets. These documents provide, for each content code, information on waste identification, waste description, waste storage configuration, physical/chemical waste composition, radionuclide and associated alpha activity waste characterization data, and hazardous constituents present in the waste. Information is provided for 97 waste streams which represent an estimated total volume of 25,450 m 3 corresponding to a total mass of approximately 12,000,000 kg. In addition, considerable information concerning alpha, beta, gamma, and neutron source term data specific to Rocky Flats-generated waste forms stored at the INEL are provided to assist in facility design specification.
11. Study of environmental contamination of Semipalatinsk region and development of rehabilitation program
International Nuclear Information System (INIS)
Artemev, O.I.; Akhmetov, M.A.; Ptitskaya, L.D.
1998-01-01
The obtained and analyzed results of the researches showed the following. 1) The exposure dose rate does not exceed the level admitted - 0.3 μSv/h. 2) Beta contamination level is below the 55 counts per minute per sq. cm, the level admitted is 200 counts per minute per sq. cm. 3) alpha contamination level is below the 2 counts per minute per sq. cm for the most part of the territory. The sites with the higher level have been detailed examined, their boundaries have been laid out. 4) 1 37C s contamination is below the level admitted. However, several points showed the values higher than those of the global fallout. 5) 9 0S r contamination is below the level admitted for the most part of the territory. The elevation observed is within the total error of the radiochemical analysis. 6) 2 39P u was detected in the majority of samples. It was detected on both the radioactive plums and outside of them. It is too early to conclude anything about Pu due to the lack of materials. It is necessary to examine the territory more detailed as the step of sampling is larger than the size of Pu contaminated sites. 7) There is no elevation of alpha, beta and gamma levels in places of people temporary living as well as no high radionuclide content. Analysis for 2 39P u was not made. 48 settlements have been investigated totally. The program developed for the environment remediation at STS is planned for many years and will be implemented stage-by-stage
12. Host-Specific Patterns of Genetic Diversity among IncI1-I gamma and IncK Plasmids Encoding CMY-2 beta-Lactamase in Escherichia coli Isolates from Humans, Poultry Meat, Poultry, and Dogs in Denmark
DEFF Research Database (Denmark)
Hansen, Katrine Hartung; Bortolaia, Valeria; Nielsen, Christine Ahl
2016-01-01
and commensal E. coli isolates collected from 2006 to 2012 from humans, retail poultry meat, broilers, and dogs. Multilocus sequence typing (MLST), antimicrobial susceptibility testing, and conjugation were performed in conjunction with plasmid replicon typing, plasmid multilocus sequence typing (p......MLST), restriction fragment length polymorphism (RFLP), and sequencing of selected bla(CMY-2)-harboring plasmids. MLST revealed high strain diversity, with few E. coli lineages occurring in multiple host species and sample types. bla(CMY-2) was detected on plasmids in 83 (89%) isolates. Most (75%) of the plasmids...... were conjugative and did not (96%) cotransfer resistance to antimicrobials other than cephalosporins. The main replicon types identified were IncI1-I gamma (55%) and IncK (39%). Isolates from different host species mainly carried distinct plasmid subtypes. Seven of the 18 human isolates harbored IncI1...
13. The BetaCage: Ultrasensitive Screener for Radioactive Backgrounds
Science.gov (United States)
Thompson, Michael; BetaCage Collaboration
2017-09-01
Rare event searches, such as dark matter detection and neutrinoless double beta decay, require screening of materials for backgrounds such as beta emission and alpha decaying isotopes. The BetaCage is a proposed ultra-sensitive time-projection chamber to screen for alpha-emitting and low energy beta-emitting (10-200 keV) contaminants. The expected sensitivity is 0.1 beta particles (perkeV -m2 - day) and 0.1 alpha particles (perm2 - day) , where the former will be limited by Compton scattering of external photons in the screening samples and the latter is expected to be signal-limited. The prototype BetaCage under commissioning at South Dakota School of Mines & Technology is filled with P10 gas (10% methane, 90% argon) in place of neon and is 40×40×20 cm in size. Details on design, construction and characterization will be presented.
14. Forward-Looking Betas
DEFF Research Database (Denmark)
Christoffersen, Peter; Jacobs, Kris; Vainberg, Gregory
Few issues are more important for finance practice than the computation of market betas. Existing approaches compute market betas using historical data. While these approaches differ in terms of statistical sophistication and the modeling of the time-variation in the betas, they are all backward......-looking. This paper introduces a radically different approach to estimating market betas. Using the tools in Bakshi and Madan (2000) and Bakshi, Kapadia and Madan (2003) we employ the information embedded in the prices of individual stock options and index options to compute our forward-looking market beta...
15. Meson exchange currents and two neutrino double beta decay
International Nuclear Information System (INIS)
Simkovic, F.
1995-01-01
By using a field theory approach a detailed analysis of the two neutrino double beta decay amplitude has been performed. We have shown that the summation over the intermediate nuclear states in the present two neutrino double beta decay studies corresponds to a summation over a class of meson exchange diagrams. We offer some arguments showing that the two nucleon mechanism considered at present does not provide the main contribution to the two neutrino double beta decay amplitude. A new electron-gamma exchange mechanism for this process is suggested. 31 refs., 1 fig
16. Development of gamma camera and application to decontamination
International Nuclear Information System (INIS)
Yoshida, Akira; Moro, Eiji; Takahashi, Isao
2013-01-01
A gamma camera has been developed to support recovering from the contamination caused by the accident of Fukushima Dai-ichi Nuclear Power Plant of Tokyo Electric Power Company. The gamma camera enables recognition of the contamination by visualizing radioactivity. The gamma camera has been utilized for risk communication (explanation to community resident) at local governments in Fukushima. From now on, the gamma camera will be applied to solve decontaminations issues; improving efficiency of decontamination, visualizing the effect of decontamination work and reducing radioactive waste. (author)
17. Gamma camera
International Nuclear Information System (INIS)
Berninger, W.H.
1975-01-01
The light pulse output of a scintillator, on which incident collimated gamma rays impinge, is detected by an array of photoelectric tubes each having a convexly curved photocathode disposed in close proximity to the scintillator. Electronic circuitry connected to outputs of the phototubes develops the scintillation event position coordinate electrical signals with good linearity and with substantial independence of the spacing between the scintillator and photocathodes so that the phototubes can be positioned as close to the scintillator as is possible to obtain less distortion in the field of view and improved spatial resolution as compared to conventional planar photocathode gamma cameras
18. Design of Dataflow Monitoring and Searches for B to omega gamma, B to phi gamma and B to phi K-short gamma at BaBar
Energy Technology Data Exchange (ETDEWEB)
Swain, J
2004-03-16
In May 2003 PEP-II achieved instantaneous luminosities in excess of 6 x 10{sup 33} cm{sup -2}s{sup -1}, twice the design luminosity. To permit BABAR to operate in this challenging environment, development work on the data acquisition system continued after detector commissioning. A vital part of this process is understanding the performance of the data acquisition system. Considerable effort was invested in the design and implementation of an application capable of collecting performance statistics from hundreds of CPUs in the data acquisition system during data collection. The monitoring application and some examples of its operation are presented in this thesis. Also presented here are the searches for the exclusive radiative one-loop decays, B {yields} {omega}{gamma}, B {yields} {phi}{gamma} and B{sup 0} {yields} {phi}K{sub S}{sup 0}{gamma}, using a sample of 89 million B{bar B} events. No significant signal is seen in any of the channels. Upper limits on the branching ratios, {Beta}, were found to be {Beta}(B {yields} {omega}{gamma}) < 3.0 x 10{sup -6}, {Beta}(B {yields} {phi}{gamma}) < 2.9 x 10{sup -6}, and {Beta}(B{sup 0} {yields} {phi}K{sub S}{sup 0}{gamma}) < 3.8 x 10{sup -6}, at the 90% confidence level.
19. Neural network consistent empirical physical formula construction for neutron–gamma discrimination in gamma ray tracking
International Nuclear Information System (INIS)
Yildiz, Nihat; Akkoyun, Serkan
2013-01-01
Highlights: ► Detector responses in neutron–gamma discrimination were estimated by neural networks. ► Novel consistent neural network empirical physical formulas (EPFs) were constructed for detector responses. ► The EPFs are of explicit mathematical functional form. ► The EPFs can be used to derive various physical functions relevant to neutron– | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8015694618225098, "perplexity": 9585.395574771841}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-30/segments/1531676589573.27/warc/CC-MAIN-20180717051134-20180717071134-00521.warc.gz"} |
http://wiki.scummvm.org/index.php/Instructions_to_Wiki_Editors | - - - -
- Buy Supported Games:
Instructions to Wiki EditorsInstructions to Wiki Editors
These instructions are written mainly with the editing of the User Manual in mind. Some of the points might also be valid for other parts of the wiki though.
# General Rules
## No controversial material
The basic rule is to keep in mind that we do not want problems with right holders and therefore we do not want to have links to illegal content or to document steps that might be illegal. An obvious example is links to so-called abandonware sites. Another less obvious example is instructions on how to jailbreak an iPhone or a Wii so that we can install ScummVM. We should write the instructions starting from the assumption that the device is already jail-broken.
## Spelling and grammar
1. For consistency sake it is better to use the American English spelling everywhere rather than mix British and American English spellings. That means that you should prefer color and finalize over colour and finalise.
2. Please do not use contractions (e.g. If you've navigated for If you have navigated). They are usually used in spoken English but not much in written English, although there are some exceptions (e.g. It doesn't work is fine for non-formal written English, as is the expanded form It does not work). If in doubt, use the expanded form. Also the User Manual is a bit more formal than for example an e-mail; and as such contractions that might be fine in an e-mail are not necessarily fine in the User Manual.
3. Do not use very complex grammatical structure or abstruse words (abstruse meaning difficult to comprehend and being an example of words to avoid). Keep in mind that many ScummVM users are not native English speakers and may not speak English as well as you do.
## User Manual content
1. Try to place yourself in the head of a complete newbie and make very explicit some information that might not be obvious for everybody. For example, instead of Navigate to the correct directory you might want to write Navigate to the directory that contains the game files.
2. ScummVM is distributed on many platforms. When giving instructions on encoding audio or similar tasks, try to cover at least Linux, Mac OS X and Windows. Most of the users will have one of these operating system.
## Translation
• At the top of the page, add the {{Languages}} template (see Template:Languages). If it is the first translation for that page, you will also need to add the template to the english page.
Note: There seems to be a small bug in the template for the moment with the detection of the page. If the bar does not have the correct list of languages, you can specify the page explicitly in the template:
{{Languages|User Manual/Introduction}}
The page name given to the template should always be the english page.
• If your translated page points to a page that is not yet translated, you might want to link to the not yet existing translated page, create that page and redirect to the english page. That way you will not have to change all the links when you decide to translate the page. For example, if you want to link to User Manual/ScummVM Interface from a German page, but User Manual/ScummVM Interface has not yet been translated to German, you might want to point to User Manual/ScummVM Interface/de anyway and create that page with the following content:
#REDIRECT [[User Manual/ScummVM Interface]]
## Trusted User Group
As a normal user there are things you cannot do on the wiki. For example you cannot delete and undelete pages or edit the wiki interfaces (e.g. modify the Sidebar). A group of users with slightly more powers than normal user exists. Membership to this group is decided on a case by case basis by the project leaders. If you want to be added to the group then contact them (e.g. by e-mail or on IRC) and they might accede to your request.
# Extensions
There are several wiki extensions installed to help you in the editing task.
## SyntaxHighlight GeSHi
This extension can be used to present source code with syntax highlighting. As you can guess for us it is mainly useful for C++ code, but it can also be used with other languages.
Syntax:
<source lang="cpp">
#include <foo.h>
class MyClass {
public:
MyClass();
~MyClass();
};
</source>
Which gives the following result:
#include <foo.h>
class MyClass {
public:
MyClass();
~MyClass();
};
Historically, we used a slightly different extension (also based on GeSHi) with a different syntax. For backward compatibility the extension now installed has been customized to also support this other syntax.
<syntax type="C++">
#include <foo.h>
class MyClass {
public:
MyClass();
~MyClass();
};
</syntax>
## MathJax
This extension can be used to generate formulas using the LaTeX math syntax. It replaces MediaWiki's regular TeX based math support (that we cannot use due to server limitations) and the old jsMath extension. It uses the same syntax as both of these, which is described here.
The following math environments are defined for inline style math:
• $$...$$ and
• $...$.
And the following math environments are defined for display style math:
• $...$,
• \begin{...}...\end{...} and
• :$...$.
MathJax produces nice and scalable mathematics, see their website (http://www.mathjax.org/) for a demonstration. This extension also enables the usage of \label{} and \eqref{} tags with automatic formula numbering.
Syntax:
$Skewness(X) = \frac{N}{(N-1)*(N-2)*\sigma(X)^3} * \sum_{i=1}^{N}{(X_i - E(X))^3}$
Which gives the following result:
$$Skewness(X) = \frac{N}{(N-1)*(N-2)*\sigma(X)^3} * \sum_{i=1}^{N}{(X_i - E(X))^3}$$
## Cite
This extension can be used to create footnotes on a wiki page.
Syntax:
You need to use the <ref> tag to define a reference:
This is an example of use of the Cite extension<ref>Criezy, ScummVM wiki, 2009</ref>.
And then to use the <references /> tag as a placeholder (e.g. at the bottom of the page for a footnote):
--- Notes ---
<references />
This example gives:
This is an example of use of the Cite extension[1].
--- Notes ---
1. Criezy, ScummVM wiki, 2009
## ParserFunctions and StringFunctions
This extension adds logical functions and functions that operate on strings to the wiki parser.
Syntax: See http://www.mediawiki.org/wiki/Help:Extension:ParserFunctions and http://www.mediawiki.org/wiki/Extension:StringFunctions for a list of functions and their syntax.
## Dynamic Page List
This extension is quite complex. Basically it can be used to display content from other pages into a wiki page.
Syntax: This extension is invoked with the parser function {{#dpl: .... }} or parser tag <DPL>. See the link above for more details and examples. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 2, "mathjax_display_tex": 1, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.3002499043941498, "perplexity": 1590.6752900741087}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": false}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2016-07/segments/1454701159654.65/warc/CC-MAIN-20160205193919-00272-ip-10-236-182-209.ec2.internal.warc.gz"} |
https://cs.stackexchange.com/questions/107116/range-of-values-for-kolmogorov-complexity | # Range of values for Kolmogorov complexity
Let $$n$$ be a positive integer. Is it true that for all $$1\leq i \leq n$$ there exists a length $$n$$ binary string $$w$$ such that $$K(w) = i$$. Where $$K(w)$$ is the Kolmogorov complexity of $$w$$.
For each $$i$$ there are clearly $$2^i$$ programs of that length. But can we be sure at least one of them (when executed) generate a length $$n$$ binary string?
The answer depends on the exact choice of program description language. We can define Kolmogorov complexity with respect to any admissible program description language. A program description language $$L$$ is admissible if for all program description languages $$L'$$, we have $$K_L(x) \leq K_{L'}(x) + C_{L'}$$, for some constant $$C_{L'}$$ depending only on $$L'$$.
We start by showing how to construct an admissible program description language in which all Kolmogorov complexities are even. Let $$L$$ be an admissible program description language. We define a new program description language $$L'$$ as follows: if $$|x|$$ is odd or $$x = \epsilon$$ then $$L'(x) = \epsilon$$; if $$|x|$$ is even and $$x=0y$$ then $$L'(x) = L(y)$$; and if $$|x|$$ is even and $$x=1y$$ then $$L'(x) = L(z)$$, where $$z$$ is obtained from $$y$$ by removing the last symbol. Since $$K_{L'}(x) \leq K_L(x) + 2$$, $$L'$$ is admissible. On the other hand, it is easy to check that $$K_{L'}$$ is always even.
Conversely, we can also arrange that all Kolmogorov complexities would be achieved. Let $$L$$ be an admissible program description language. We construct a new admissible program description language $$L'$$ as follows: $$L'(\epsilon) = z$$, where $$z$$ is some string satisfying $$K_L(z) < |z|$$ (we can choose $$z = 0^{2^n}$$ for large enough $$n$$); $$L'(0x) = x$$; and $$L'(1x) = L(x)$$. Then $$K_{L'}(z) = 0$$, and for $$w \neq z$$, we have $$K_{L'}(w) = \min(|w|,K_L(w)) + 1$$. For every $$n \geq 1$$, we can find a string $$w$$ of length $$n-1$$ such that $$K_L(w) \geq n-1$$. This string satisfies $$K_{L'}(w) = n$$.
• So for each Kolmogorov complexity value you want to achieve, you need to build a new program interpreter that achieves it for some binary string of length $n$. – JtailHyper Apr 17 '19 at 22:12
• In your example, you say that we can find a length $n-1$ string $w$ such that $K_{L'}(w) = n$. I understand this, you're simply using the fact that there is at least one incompressible string for each $n$, and the rest follows from your definition of $L'$. But I don't quite see how your construction of $L'$ hits every Kolmogorov complexity between $1$ and $n$ for some length $n$ binary string. Could you explain this a little more? Sorry if my question seems dumb, I have almost no intuition for Kolmogorov complexity. – JtailHyper Apr 17 '19 at 22:34
• The definition of $L'$ doesn't depend on $n$. – Yuval Filmus Apr 17 '19 at 22:35 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 48, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9217261075973511, "perplexity": 106.5307704828089}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-16/segments/1585370524043.56/warc/CC-MAIN-20200404134723-20200404164723-00539.warc.gz"} |
https://worldwidescience.org/topicpages/h/high+sensitivity+charge.html | Sample records for high sensitivity charge
1. Novel charge sensitive preamplifier without high-value feedback resistor
International Nuclear Information System (INIS)
Xi Deming
1992-01-01
A novel charge sensitive preamplifier is introduced. The method of removing the high value feedback resistor, the circuit design and analysis are described. A practical circuit and its measured performances are provided
2. Design of a charge sensitive preamplifier on high resistivity silicon
International Nuclear Information System (INIS)
Radeka, V.; Rehak, P.; Rescia, S.; Gatti, E.; Longoni, A.; Sampietro, M.; Holl, P.; Strueder, L.; Kemmer, J.
1987-01-01
A low noise, fast charge sensitive preamplifier was designed on high resistivity, detector grade silicon. It is built at the surface of a fully depleted region of n-type silicon. This allows the preamplifier to be placed very close to a detector anode. The preamplifier uses the classical input cascode configuration with a capacitor and a high value resistor in the feedback loop. The output stage of the preamplifier can drive a load up to 20pF. The power dissipation of the preamplifier is 13mW. The amplifying elements are ''Single Sided Gate JFETs'' developed especially for this application. Preamplifiers connected to a low capacitance anode of a drift type detector should achieve a rise time of 20ns and have an equivalent noise charge (ENC), after a suitable shaping, of less than 50 electrons. This performance translates to a position resolution better than 3μm for silicon drift detectors. 6 refs., 9 figs
3. Development of Charge Sensitive Preamplifier and Readout Integrate Circuit Board for High Resolution Detector using ASIC Process
Energy Technology Data Exchange (ETDEWEB)
Jeon, J. Y.; Kim, J. H.; Park, J. M.; Yang, J. Y.; Kim, K. Y.; Kim, Y. S. [RadTek Co., Daejeon (Korea, Republic of)
2010-06-15
- Design of discrete type charge sensitive amplifier for high resolution semi-conductor sensor - Design and develop the test board for the performance of charge sensitive amplifier with sensor - Performance of electrical test for the sensor and charge sensitive amplifier - Development of prototype 8 x 8 array type detector module - Noise equivalent charge test for the charge sensitive amplifier - Design and development of Micro SMD discrete type amplifier applying ASIC procedure - Development of Hybrid type charge sensitive amplifier including shape
4. A new method of removing the high value feedback resistor in the charge sensitive preamplifier
International Nuclear Information System (INIS)
Xi Deming
1993-01-01
A new method of removing the high value feedback resistor in the charge sensitive preamplifier is introduced. The circuit analysis of this novel design is described and the measured performances of a practical circuit are provided
5. Highly Sensitive Bulk Silicon Chemical Sensors with Sub-5 nm Thin Charge Inversion Layers.
Science.gov (United States)
Fahad, Hossain M; Gupta, Niharika; Han, Rui; Desai, Sujay B; Javey, Ali
2018-03-27
There is an increasing demand for mass-producible, low-power gas sensors in a wide variety of industrial and consumer applications. Here, we report chemical-sensitive field-effect-transistors (CS-FETs) based on bulk silicon wafers, wherein an electrostatically confined sub-5 nm thin charge inversion layer is modulated by chemical exposure to achieve a high-sensitivity gas-sensing platform. Using hydrogen sensing as a "litmus" test, we demonstrate large sensor responses (>1000%) to 0.5% H 2 gas, with fast response (<60 s) and recovery times (<120 s) at room temperature and low power (<50 μW). On the basis of these performance metrics as well as standardized benchmarking, we show that bulk silicon CS-FETs offer similar or better sensing performance compared to emerging nanostructures semiconductors while providing a highly scalable and manufacturable platform.
6. Charge Transfer Dynamics of Highly Efficient Cyanidin-3-O- Glucoside Sensitizer for Dye-Sensitized Solar Cells
International Nuclear Information System (INIS)
Prima, E C; Yuliarto, B; Suyatman; Dipojono, H K
2016-01-01
This paper reports the novel efficiency achievement of black rice-based natural dye- sensitized solar cells. The higher dye concentration, the longer dye extraction as well as dye immersion onto a TiO 2 film, and the co-adsorption addition are key strategies for improved-cell performance compared to the highest previous achievement. The black rice dye containing 1.38 mM cyanidin-3-O-glucoside has been extracted without purification for 3 weeks at dark condition and room temperature. The anatase TiO 2 photoanode was dipped into dye solution within 4 days. Its electrode was firmly sealed to be a cell and was filled by I - /I 3 - electrolyte using vacuum technique. As a result, the overall solar-to-energy conversion efficiency was 1.49% at AM 1.5 illumination (100 mW.cm -2 ). The voltametric analysis has reported the interfacial electronic band edges of TiO 2 -Dye-Electrolyte. Furthermore, electrochemical impedance spectroscopy has shown the kinetic of interfacial electron transfer dynamics among TiO 2 -dye-electrolyte. The cell has the transfer resistance (Rt) of 12.5 ω, the recombination resistance (Rr) of 266.8 ω, effective electron diffusion coefficients (Dn) of 1.4 × 10 -3 cm 2 /s, Dye-TiO 2 effective electron transfer (τ d ) of 26.6 μs, effective diffusion length (L n )of 33.78 μm, chemical capacitance (C μ ) of 12.43 μF, and electron lifetime (τ n ) of 3.32 ms. (paper)
7. Performance of a position sensitive Si(Li) x-ray detector dedicated to Compton polarimetry of stored and trapped highly-charged ions
International Nuclear Information System (INIS)
Weber, G; Braeuning, H; Hess, S; Maertin, R; Spillmann, U; Stoehlker, Th
2010-01-01
We report on a novel two-dimensional position sensitive Si(Li) detector dedicated to Compton polarimetry of x-ray radiation arising from highly-charged ions. The performance of the detector system was evaluated in ion-atom collision experiments at the ESR storage ringe at GSI, Darmstadt. Based on the data obtained, the polarimeter efficiency is estimated in this work.
8. Charge sensitive amplifies. The state of arts
Energy Technology Data Exchange (ETDEWEB)
Mori, Kunishiro [Clear Pulse Co., Tokyo (Japan)
1996-07-01
In the radiation detectors, signals are essentially brought with charges produced by radiation, then it is naturally the best way to use a charge sensitive amplifier (CSA) system to extract those signals. The CSA is thought to be the best amplifier suitable to almost all the radiation detectors, if neglecting economical points of view. The CSA has been only applied to special fields like radiation detection because the concept of charges is not so universal against the concepts of voltage and current. The CSA, however, is low in noise and a high speed amplifier and may be applicable not only to radiation measurement but also piezoelectric devices and also bolometers. In this article, noise in the CSA, basic circuit on the CSA, concepts of equivalent noise charge (ENC), a method for the ENC, and importance of the open-loop gain in the CSA to achieve better performance of it and how to realize in a practical CSA were described. And, characteristics on a counting rate of the CSA, various circuit used in the CSA, and CSAs which are commercially available at present and special purpose CSAs were also introduced. (G.K.)
9. DFT-INDO/S modeling of new high molar extinction coefficient charge-transfer sensitizers for solar cell applications.
Science.gov (United States)
Nazeeruddin, Mohammad K; Wang, Qing; Cevey, Le; Aranyos, Viviane; Liska, Paul; Figgemeier, Egbert; Klein, Cedric; Hirata, Narukuni; Koops, Sara; Haque, Saif A; Durrant, James R; Hagfeldt, Anders; Lever, A B P; Grätzel, Michael
2006-01-23
A new ruthenium(II) complex, tetrabutylammonium [ruthenium (4-carboxylic acid-4'-carboxylate-2,2'-bipyridine)(4,4'-di(2-(3,6-dimethoxyphenyl)ethenyl)-2,2'-bipyridine)(NCS)(2)] (N945H), was synthesized and characterized by analytical, spectroscopic, and electrochemical techniques. The absorption spectrum of the N945H sensitizer is dominated by metal-to-ligand charge-transfer (MLCT) transitions in the visible region, with the lowest allowed MLCT bands appearing at 25 380 and 18 180 cm(-1). The molar extinction coefficients of these bands are 34 500 and 18 900 M(-1) cm(-1), respectively, and are significantly higher when compared to than those of the standard sensitizer cis-dithiocyanatobis(4,4'-dicarboxylic acid-2,2'-bipyridine)ruthenium(II). An INDO/S and density functional theory study of the electronic and optical properties of N945H and of N945 adsorbed on TiO(2) was performed. The calculations point out that the top three frontier-filled orbitals have essentially ruthenium 4d (t(2g) in the octahedral group) character with sizable contribution coming from the NCS ligand orbitals. Most critically the calculations reveal that, in the TiO(2)-bound N945 sensitizer, excitation directs charge into the carboxylbipyridine ligand bound to the TiO(2) surface. The photovoltaic data of the N945 sensitizer using an electrolyte containing 0.60 M butylmethylimidazolium iodide, 0.03 M I(2), 0.10 M guanidinium thiocyanate, and 0.50 M tert-butylpyridine in a mixture of acetonitrile and valeronitrile (volume ratio = 85:15) exhibited a short-circuit photocurrent density of 16.50 +/- 0.2 mA cm(-2), an open-circuit voltage of 790 +/- 30 mV, and a fill factor of 0.72 +/- 0.03, corresponding to an overall conversion efficiency of 9.6% under standard AM (air mass) 1.5 sunlight, and demonstrated a stable performance under light and heat soaking at 80 degrees C.
10. High Voltage Charge Pump
KAUST Repository
Emira, Ahmed A.; Abdelghany, Mohamed A.; Elsayed, Mohannad Yomn; Elshurafa, Amro M; Salama, Khaled N.
2014-01-01
Various embodiments of a high voltage charge pump are described. One embodiment is a charge pump circuit that comprises a plurality of switching stages each including a clock input, a clock input inverse, a clock output, and a clock output inverse. The circuit further comprises a plurality of pumping capacitors, wherein one or more pumping capacitors are coupled to a corresponding switching stage. The circuit also comprises a maximum selection circuit coupled to a last switching stage among the plurality of switching stages, the maximum selection circuit configured to filter noise on the output clock and the output clock inverse of the last switching stage, the maximum selection circuit further configured to generate a DC output voltage based on the output clock and the output clock inverse of the last switching stage.
11. High Voltage Charge Pump
KAUST Repository
Emira, Ahmed A.
2014-10-09
Various embodiments of a high voltage charge pump are described. One embodiment is a charge pump circuit that comprises a plurality of switching stages each including a clock input, a clock input inverse, a clock output, and a clock output inverse. The circuit further comprises a plurality of pumping capacitors, wherein one or more pumping capacitors are coupled to a corresponding switching stage. The circuit also comprises a maximum selection circuit coupled to a last switching stage among the plurality of switching stages, the maximum selection circuit configured to filter noise on the output clock and the output clock inverse of the last switching stage, the maximum selection circuit further configured to generate a DC output voltage based on the output clock and the output clock inverse of the last switching stage.
12. Conformation sensitive charge transport in conjugated polymers
International Nuclear Information System (INIS)
2013-01-01
Temperature dependent charge carrier mobility measurements using field effect transistors and density functional theory calculations are combined to show how the conformation dependent frontier orbital delocalization influences the hole- and electron mobilities in a donor-acceptor based polymer. A conformationally sensitive lowest unoccupied molecular orbital results in an electron mobility that decreases with increasing temperature above room temperature, while a conformationally stable highest occupied molecular orbital is consistent with a conventional hole mobility behavior and also proposed to be one of the reasons for why the material works well as a hole transporter in amorphous bulk heterojunction solar cells
13. Theoretical investigation of the charge-transfer properties in different meso-linked zinc porphyrins for highly efficient dye-sensitized solar cells.
Science.gov (United States)
Namuangruk, Supawadee; Sirithip, Kanokkorn; Rattanatwan, Rattanawelee; Keawin, Tinnagon; Kungwan, Nawee; Sudyodsuk, Taweesak; Promarak, Vinich; Surakhot, Yaowarat; Jungsuttiwong, Siriporn
2014-06-28
The charge transfer effect of different meso-substituted linkages on porphyrin analogue 1 (A1, B1 and C1) was theoretically investigated using density functional theory (DFT) and time-dependent DFT (TDDFT) calculations. The calculated geometry parameters and natural bond orbital analysis reveal that the twisted conformation between porphyrin macrocycle and meso-substituted linkages leads to blocking of the conjugation of the conjugated backbone, and the frontier molecular orbital plot shows that the intramolecular charge transfer of A1, B1 and C1 hardly takes place. In an attempt to improve the photoinduced intramolecular charge transfer ability of the meso-linked zinc porphyrin sensitizer, a strong electron-withdrawing group (CN) was introduced into the anchoring group of analogue 1 forming analogue 2 (A2, B2 and C2). The density difference plot of A2, B2 and C2 shows that the charge transfer properties dramatically improved. The electron injection process has been performed using TDDFT; the direct charge-transfer transition in the A2-(TiO2)38 interacting system takes place; our results strongly indicated that introducing electron-withdrawing groups into the acceptor part of porphyrin dyes can fine-tune the effective conjugation length of the π-spacer and improve intramolecular charge transfer properties, consequently inducing the electron injection process from the anchoring group of the porphyrin dye to the (TiO2)38 surface which may improve the conversion efficiency of the DSSCs. Our calculated results can provide valuable information and a promising outlook for computation-aided sensitizer design with anticipated good properties in further experimental synthesis.
14. Transaction charges allocation using sensitivity factor methodology
Under this framework, the transmission tariff charged for the customers becomes ... Ni et al (2000) applied graph theory to solve the problem of power flow .... The coefficient of linear relationship between the amount of transaction and flow on.
15. Highly efficient ZnO/Au Schottky barrier dye-sensitized solar cells: Role of gold nanoparticles on the charge-transfer process
Directory of Open Access Journals (Sweden)
Tanujjal Bora
2011-10-01
Full Text Available Zinc oxide (ZnO nanorods decorated with gold (Au nanoparticles have been synthesized and used to fabricate dye-sensitized solar cells (DSSC. The picosecond-resolved, time-correlated single-photon-count (TCSPC spectroscopy technique was used to explore the charge-transfer mechanism in the ZnO/Au-nanocomposite DSSC. Due to the formation of the Schottky barrier at the ZnO/Au interface and the higher optical absorptions of the ZnO/Au photoelectrodes arising from the surface plasmon absorption of the Au nanoparticles, enhanced power-conversion efficiency (PCE of 6.49% for small-area (0.1 cm2 ZnO/Au-nanocomposite DSSC was achieved compared to the 5.34% efficiency of the bare ZnO nanorod DSSC. The TCSPC studies revealed similar dynamics for the charge transfer from dye molecules to ZnO both in the presence and absence of Au nanoparticles. A slower fluorescence decay associated with the electron recombination process, observed in the presence of Au nanoparticles, confirmed the blocking of the electron transfer from ZnO back to the dye or electrolyte by the Schottky barrier formed at the ZnO/Au interface. For large area DSSC (1 cm2, ~130% enhancement in PCE (from 0.50% to 1.16% was achieved after incorporation of the Au nanoparticles into the ZnO nanorods.
16. Coordinate-sensitive charged particle detector for spectroscopy
Directory of Open Access Journals (Sweden)
Sidorenko V. P.
2016-10-01
Full Text Available The authors have designed, manufactured and tested a coordinate-sensitive detector for charged particle spectroscopy. The detector can be used in the devices for the elemental analysis of materials, providing simultaneous analysis of all the elemental composition with high sensitivity and precision. The designed device is based on an integrated circuit (IC and a microchannel plate (MCP electron multiplier. The IC is mounted on a ceramic substrate. Ions fall on the MCP mounted above the IC. Giving rise to a pulse which typically exceeds 106 electrons, each ion falls on the detector electrodes and these pulses are counted. In this research, a two stage stack of MCPs (Hamamatsu was used. The MCPs have a channel diameter of 12 μm on a 15 μm pitch. The results of tests carried out in a mass spectrometer are presented. The designed detector is small, light, and low-power.
17. High-Sensitivity Spectrophotometry.
Science.gov (United States)
Harris, T. D.
1982-01-01
Selected high-sensitivity spectrophotometric methods are examined, and comparisons are made of their relative strengths and weaknesses and the circumstances for which each can best be applied. Methods include long path cells, noise reduction, laser intracavity absorption, thermocouple calorimetry, photoacoustic methods, and thermo-optical methods.…
CERN Document Server
Schneider, Kerstin
2006-01-01
Highly Sensitive Optical Receivers primarily treats the circuit design of optical receivers with external photodiodes. Continuous-mode and burst-mode receivers are compared. The monograph first summarizes the basics of III/V photodetectors, transistor and noise models, bit-error rate, sensitivity and analog circuit design, thus enabling readers to understand the circuits described in the main part of the book. In order to cover the topic comprehensively, detailed descriptions of receivers for optical data communication in general and, in particular, optical burst-mode receivers in deep-sub-µm CMOS are presented. Numerous detailed and elaborate illustrations facilitate better understanding.
19. Resistor-less charge sensitive amplifier for semiconductor detectors
Energy Technology Data Exchange (ETDEWEB)
Pelczar, K., E-mail: krzysztof.pelczar@doctoral.uj.edu.pl; Panas, K.; Zuzel, G.
2016-11-01
A new concept of a Charge Sensitive Amplifier without a high-value resistor in the feedback loop is presented. Basic spectroscopic parameters of the amplifier coupled to a coaxial High Purity Germanium detector (HPGe) are discussed. The amplifier signal input is realized with an n-channel J-FET transistor. The feedback capacitor is discharged continuously by the second, forward biased n-channel J-FET, driven by an RC low–pass filter. Both the analog—with a standard spectroscopy amplifier and a multi-channel analyzer—and the digital—by applying a Flash Analog to Digital Converter—signal readouts were tested. The achieved resolution in the analog and the digital readouts was 0.17% and 0.21%, respectively, at the Full Width at Half Maximum of the registered {sup 60}Co 1332.5 keV gamma line.
20. Surface charge compensation for a highly charged ion emission microscope
International Nuclear Information System (INIS)
McDonald, J.W.; Hamza, A.V.; Newman, M.W.; Holder, J.P.; Schneider, D.H.G.; Schenkel, T.
2003-01-01
A surface charge compensation electron flood gun has been added to the Lawrence Livermore National Laboratory (LLNL) highly charged ion (HCI) emission microscope. HCI surface interaction results in a significant charge residue being left on the surface of insulators and semiconductors. This residual charge causes undesirable aberrations in the microscope images and a reduction of the Time-Of-Flight (TOF) mass resolution when studying the surfaces of insulators and semiconductors. The benefits and problems associated with HCI microscopy and recent results of the electron flood gun enhanced HCI microscope are discussed
1. Current feedback operational amplifiers as fast charge sensitive preamplifiers for photomultiplier read out
Energy Technology Data Exchange (ETDEWEB)
Giachero, A; Gotti, C; Maino, M; Pessina, G, E-mail: claudio.gotti@mib.infn.it [INFN - Sezione di Milano-Bicocca, I-20126, Milano (Italy)
2011-05-01
Fast charge sensitive preamplifiers were built using commercial current feedback operational amplifiers for fast read out of charge pulses from a photomultiplier tube. Current feedback opamps prove to be particularly well suited for this application where the charge from the detector is large, of the order of one million electrons, and high timing resolution is required. A proper circuit arrangement allows very fast signals, with rise times down to one nanosecond, while keeping the amplifier stable. After a review of current feedback circuit topology and stability constraints, we provide a 'recipe' to build stable and very fast charge sensitive preamplifiers from any current feedback opamp by adding just a few external components. The noise performance of the circuit topology has been evaluated and is reported in terms of equivalent noise charge.
2. Design of A Charge sensitive preamplifier based on DMOS FET
International Nuclear Information System (INIS)
Gao Yanni; Su Hong; Wembe Tafo Evariste
2010-01-01
A charge sensitive preamplifier composed of DMOS for silicon, TSi (Li), CdZnTe and CsI detectors etc was proposed in the paper. It used a circuit structure different from traditional one with resistance and capacitance feedback. It was composed of DMOS only so that it can be developed further easily to make Application Specific Integrated Circuit. We also find it has a rise time less than 15ns and good stability from the result of simulation with Multisim. (authors)
3. A comparison of charged coupled devices and film sensitivities
International Nuclear Information System (INIS)
Wallick, W.O.; Kenyon, R.G.; Lubatti, H.J.
1977-01-01
The response of a charged coupled device (Fairchild CCD-202) to a Ne light source is studied and compared to the Kodak SO-143 film commonly used for streamer chamber applications. It is found that the CCD-202 cooled to - 10 0 C is considerebly more sensitive than the film. The advantages of using a CCD camera system for streamer chamber and other applications is discussed. (Auth.)
4. Charged current weak interactions at high energy
International Nuclear Information System (INIS)
Cline, D.
1977-01-01
We review high energy neutrino and antineutrino charged current interactions. An overview of the experimental data is given, including a discussion of the experimental status of the y anomaly. Locality tests, μ-e universality and charge symmetry invariance tests are discussed. Charm production is discussed. The experimental status of trimuon events and possible phenomenological models for these events are presented. (orig.) [de
5. ECRIS sources for highly charged ions
International Nuclear Information System (INIS)
Geller, R.
1991-01-01
The so-called Philips ionization gauge ion sources (PIGIS) were used until quite recently in heavy ion accelerators so multiply charged ions could only be obtained by incorporating a stripper to remove electrons. Electron cyclotron resonance ion sources (ECRIS) now dominate as they produce more highly charged ions. (orig.)
6. A novel charge sensitive preamplifier without the feedback resistor
International Nuclear Information System (INIS)
Bertuccio, G.
1992-01-01
A novel charge sensitive preamplifier which has no resistor in parallel with the feedback capacitor is presented. No external device or circuit is required to discharge the feedback capacitor. The detector leakage and signal current flows away through the gate of the first JFET which works with its gate to source junction slightly forward biased. The DC stabilization of the preamplifier is accomplished by an additional feedback loop, which permits to equalize the current flowing through the forward baised gate to source junction and the current coming from the detector. An equivalent noise charge of less than 20 electrons r.m.s. has been measured at room temperature by using an input JFET with a transconductance to gate capacitance ratio of 4 mS/5.4 pF
7. Highly charged ion trapping and cooling
International Nuclear Information System (INIS)
Beck, B. R.; Church, D. A.; Gruber, L.; Holder, J. P.; Schneider, D.; Steiger, J.
1998-01-01
In the past few years a cryogenic Penning trap (RETRAP) has been operational at the Electron Beam Ion Trap (EBIT) facility at Lawrence Livermore National Laboratory. The combination of RETRAP and EBIT provides a unique possibility of producing and re-trapping highly charged ions and cooling them to very low temperatures. Due to the high Coulomb potentials in such an ensemble of cold highly charged ions the Coulomb coupling parameter (the ratio of Coulomb potential to the thermal energy) can easily reach values of 172 and more. To study such systems is not only of interest in astrophysics to simulate White Dwarf star interiors but opens up new possibilities in a variety of areas (e.g. laser spectroscopy), cold highly charged ion beams
8. Charged vortices in high-Tc superconductors
International Nuclear Information System (INIS)
Matsuda, Y.; Kumagai, K.
2002-01-01
It is well known that a vortex in type II superconductors traps a magnetic flux. Recently the possibility that a vortex can accumulate a finite electric charge as well has come to be realized. The sign and magnitude of the vortex charge not only is closely related to the microscopic electronic structure of the vortex, but also strongly affects the dynamical properties of the vortex. In this chapter we demonstrate that a vortex in high-T c superconductors (HTSC) indeed traps a finite electronic charge, using the high resolution measurements of the nuclear quadrupole frequencies. We then discuss the vortex Hall anomaly whose relation with the vortex charging effect has recently received considerable attention. We show that the sign of the trapped charge is opposite to the sign predicted by the conventional BCS theory and deviation of the magnitude of the charge from the theory is also significant. We also show that the electronic structure of underlying system is responsible for the Hall sign in the vortex state and again the Hall sign is opposite to the sign predicted by the BCS theory. It appears that these unexpected features observed in both electrostatics and dynamics of the vortex may be attributed to the novel electronic structure of the vortex in HTSC. (orig.)
9. Charge-sensitive preamplifier IC for silicon calorimetry at colliders
International Nuclear Information System (INIS)
Baturitsky, M.A.; Chekhovsky, V.A.; Emel'yanchik, I.F.; Shumeiko, N.M.; Golutvin, I.A.; Zamyatin, N.I.; Dvornikov, O.V.
1995-01-01
Four versions of a fast monolithic charge-sensitive preamplifier (CSP) were designed using microwave BJT-JFET technology. The best one has a 3.5 ns rise time for input detector capacitance C d =100 pF and approximately 8 mW power dissipation for 5 V supply voltage. The ENC performance at shaping time 30 ns is 1350 e+17 e/pF for C d up to 600 pF. Crosstalk in a four-channel amplifier made in the same chip was measured to be about -46 dB for C d =100 pF. The linear output voltage swing is 0.8 V for voltage supply 5 V. The IC has revealed good radiation hardness to neutron irradiation. ((orig.))
10. Atomic structure of highly-charged ions. Final report
International Nuclear Information System (INIS)
Livingston, A. Eugene
2002-01-01
Atomic properties of multiply charged ions have been investigated using excitation of energetic heavy ion beams. Spectroscopy of excited atomic transitions has been applied from the visible to the extreme ultraviolet wavelength regions to provide accurate atomic structure and transition rate data in selected highly ionized atoms. High-resolution position-sensitive photon detection has been introduced for measurements in the ultraviolet region. The detailed structures of Rydberg states in highly charged beryllium-like ions have been measured as a test of long-range electron-ion interactions. The measurements are supported by multiconfiguration Dirac-Fock calculations and by many-body perturbation theory. The high-angular-momentum Rydberg transitions may be used to establish reference wavelengths and improve the accuracy of ionization energies in highly charged systems. Precision wavelength measurements in highly charged few-electron ions have been performed to test the most accurate relativistic atomic structure calculations for prominent low-lying excited states. Lifetime measurements for allowed and forbidden transitions in highly charged few-electron ions have been made to test theoretical transition matrix elements for simple atomic systems. Precision lifetime measurements in laser-excited alkali atoms have been initiated to establish the accuracy of relativistic atomic many-body theory in many-electron systems
11. Beta decay of highly charged ions
International Nuclear Information System (INIS)
Litvinov, Yuri A; Bosch, Fritz
2011-01-01
Beta decay of highly charged ions has attracted much attention in recent years. An obvious motivation for this research is that stellar nucleosynthesis proceeds at high temperatures where the involved atoms are highly ionized. Another important reason is addressing decays of well-defined quantum-mechanical systems, such as one-electron ions where all interactions with other electrons are excluded. The largest modifications of nuclear half-lives with respect to neutral atoms have been observed in beta decay of highly charged ions. These studies can be performed solely at ion storage rings and ion traps, because there high atomic charge states can be preserved for extended periods of time (up to several hours). Currently, all experimental results available in this field originate from experiments at the heavy-ion complex GSI in Darmstadt. There, the fragment separator facility FRS allows the production and separation of exotic, highly charged nuclides, which can then be stored and investigated in the storage ring facility ESR. In this review, we present and discuss in particular two-body beta decays, namely bound-state beta decay and orbital electron capture. Although we focus on experiments conducted at GSI, we will also attempt to provide general requirements common to any other experiment in this context. Finally, we address challenging but not yet performed experiments and we give prospects for the new radioactive beam facilities, such as FAIR in Darmstadt, IMP in Lanzhou and RIKEN in Wako.
12. High order depletion sensitivity analysis
International Nuclear Information System (INIS)
Naguib, K.; Adib, M.; Morcos, H.N.
2002-01-01
A high order depletion sensitivity method was applied to calculate the sensitivities of build-up of actinides in the irradiated fuel due to cross-section uncertainties. An iteration method based on Taylor series expansion was applied to construct stationary principle, from which all orders of perturbations were calculated. The irradiated EK-10 and MTR-20 fuels at their maximum burn-up of 25% and 65% respectively were considered for sensitivity analysis. The results of calculation show that, in case of EK-10 fuel (low burn-up), the first order sensitivity was found to be enough to perform an accuracy of 1%. While in case of MTR-20 (high burn-up) the fifth order was found to provide 3% accuracy. A computer code SENS was developed to provide the required calculations
13. High sensitivity optical molecular imaging system
Science.gov (United States)
An, Yu; Yuan, Gao; Huang, Chao; Jiang, Shixin; Zhang, Peng; Wang, Kun; Tian, Jie
2018-02-01
Optical Molecular Imaging (OMI) has the advantages of high sensitivity, low cost and ease of use. By labeling the regions of interest with fluorescent or bioluminescence probes, OMI can noninvasively obtain the distribution of the probes in vivo, which play the key role in cancer research, pharmacokinetics and other biological studies. In preclinical and clinical application, the image depth, resolution and sensitivity are the key factors for researchers to use OMI. In this paper, we report a high sensitivity optical molecular imaging system developed by our group, which can improve the imaging depth in phantom to nearly 5cm, high resolution at 2cm depth, and high image sensitivity. To validate the performance of the system, special designed phantom experiments and weak light detection experiment were implemented. The results shows that cooperated with high performance electron-multiplying charge coupled device (EMCCD) camera, precision design of light path system and high efficient image techniques, our OMI system can simultaneously collect the light-emitted signals generated by fluorescence molecular imaging, bioluminescence imaging, Cherenkov luminance and other optical imaging modality, and observe the internal distribution of light-emitting agents fast and accurately.
14. A two-dimensional position sensitive gas chamber with scanned charge transfer readout
International Nuclear Information System (INIS)
Gomez, F.; Iglesias, A.; Lobato, R.; Mosquera, J.; Pardo, J.; Pena, J.; Pazos, A.; Pombar, M.; Rodriguez, A.
2003-01-01
We have constructed and tested a two-dimensional position sensitive parallel-plate gas ionization chamber with scanned charge transfer readout. The scan readout method described here is based on the development of a new position-dependent charge transfer technique. It has been implemented by using gate strips perpendicularly oriented to the collector strips. This solution reduces considerably the number of electronic readout channels needed to cover large detector areas. The use of a 25 μm thick kapton etched circuit allows high charge transfer efficiency with a low gating voltage, consequently needing a very simple commutating circuit. The present prototype covers 8x8 cm 2 with a pixel size of 1.27x1.27 mm 2 . Depending on the intended use and beam characteristics a smaller effective pixel is feasible and larger active areas are possible. This detector can be used for X-ray or other continuous beam intensity profile monitoring
15. Precision laser spectroscopy of highly charged ions
International Nuclear Information System (INIS)
Kuehl, T.; Borneis, S.; Becker, S.; Dax, A.; Engel, T.; Grieser, R.; Huber, G.; Klaft, I.; Klepper, O.; Kohl, A.; Marx, D.; Meier, K.; Neumann, R.; Schmitt, F.; Seelig, P.; Voelker, L.
1996-01-01
Recently, intense beams of highly charged ions have become available at heavy ion cooler rings. The obstacle for producing these highly interesting candidates is the large binding energy of K-shell electrons in heavy systems in excess of 100 keV. One way to remove these electrons is to strip them off by passing the ion through material. In the cooler ring, the ions are cooled to a well defined velocity. At the SIS/ESR complex it is possible to produce, store, and cool highly charged ions up to bare uranium with intensities exceeding 10 8 atoms in the ring. This opens the door for precision laser spectroscopy of hydrogenlike-heavy ions, e.g. 209 Bi 82+ , and allows to examine the interaction of the single electron with the large fields of the heavy nucleus, exceeding any artificially produced electric and magnetic fields by orders of magnitude. In the electron cooler the interaction of electrons and highly charged ions otherwise only present in the hottest plasmas can be studied. (orig.)
16. Sensitized charge carrier injection into organic crystals studied by isotope effects in weak magnetic fields
International Nuclear Information System (INIS)
Bube, W.; Michel-Beyerle, M.E.; Haberkorn, R.; Steffens, E.
1977-01-01
The magnetic field (H approximately 50 Oe) dependence of the rhodamine sensitized triplet exciton density in anthracene crystals is influenced by isotopic substitution. This confirms the hyperfine interaction as mechanism explaining the change of the spin multiplicity in the initially formed singlet state of the radical pair. The isotope effect occurs in the sensitizing dye ( 14 N/ 15 N) rather than at the molecular site of the injected charge within the crystal. This can be understood in terms of the high hopping frequency of the charge carriers as compared to the time constant of the hyperfine induced singlet-triplet transition. Since the dye molecules adsorb in an oriented fashion, the angular dependence of the magnetic field modulation of the triplet exciton density can be interpreted without assuming any additional interactions. (Auth.)
International Nuclear Information System (INIS)
Castro, J.R.; California Univ., San Francisco, CA
1991-07-01
The Department of Radiation Oncology at UCSF Medical Center and the Radiation Oncology Department at UC Lawrence Berkeley Laboratory have been evaluating the use of high LET charged particle radiotherapy in a Phase 1--2 research trial ongoing since 1979. In this clinical trail, 239 patients have received at least 10 Gy (physical) minimum tumor dose with neon ions, meaning that at least one-half of their total treatment was given with high-LET charged particle therapy. Ninety-one patients received all of their therapy with neon ions. Of the 239 patients irradiated, target sites included lesions in the skin, subcutaneous tissues, head and neck such as paranasal sinuses, nasopharynx and salivary glands (major and minor), skull base and juxtaspinal area, GI tract including esophagus, pancreas and biliary tract, prostate, lung, soft tissue and bone. Analysis of these patients has been carried out with a minimum followup period of 2 years
18. Mechanisms for production of highly charged ions
International Nuclear Information System (INIS)
McGuire, J.H.
1987-01-01
Various experimental data at high collision velocity are interpreted in terms of direct (D) and rearrangement (R) mechanisms for production of multiply charged ions. We consider double ionization in helium by protons, electrons, heavy ions, antiprotons, positrons and photons. Qualitative differences are discussed in the context of the R and D mechanisms. Multiple ionization in many electron atoms is considered as is simultaneous capture and ionization and fragmentation of methane molecules. Some other theoretical methods are briefly discussed. (orig.)
19. Analytical bounds on SET charge sensitivity for qubit readout in a solid-state quantum computer
International Nuclear Information System (INIS)
Green, F.; Buehler, T.M.; Brenner, R.; Hamilton, A.R.; Dzurak, A.S.; Clark, R.G.
2002-01-01
Full text: Quantum Computing promises processing powers orders of magnitude beyond what is possible in conventional silicon-based computers. It harnesses the laws of quantum mechanics directly, exploiting the in built potential of a wave function for massively parallel information processing. Highly ordered and scaleable arrays of single donor atoms (quantum bits, or qubits), embedded in Si, are especially promising; they are a very natural fit to the existing, highly sophisticated, Si industry. The success of Si-based quantum computing depends on precisely initializing the quantum state of each qubit, and on precise reading out its final form. In the Kane architecture the qubit states are read out by detecting the spatial distribution of the donor's electron cloud using a sensitive electrometer. The single-electron transistor (SET) is an attractive candidate readout device for this, since the capacitive, or charging, energy of a SET's metallic central island is exquisitely sensitive to its electronic environment. Use of SETs as high-performance electrometers is therefore a key technology for data transfer in a solid-state quantum computer. We present an efficient analytical method to obtain bounds on the charge sensitivity of a single electron transistor (SET). Our classic Green-function analysis provides reliable estimates of SET sensitivity optimizing the design of the readout hardware. Typical calculations, and their physical meaning, are discussed. We compare them with the measured SET-response data
20. Spectroscopy with trapped highly charged ions
International Nuclear Information System (INIS)
Beiersdorfer, Peter
2009-01-01
We give an overview of atomic spectroscopy performed on electron beam ion traps at various locations throughout the world. Spectroscopy at these facilities contributes to various areas of science and engineering, including but not limited to basic atomic physics, astrophysics, extreme ultraviolet lithography, and the development of density and temperature diagnostics of fusion plasmas. These contributions are accomplished by generating, for example, spectral surveys, making precise radiative lifetime measurements, accounting for radiative power emitted in a given wavelength band, illucidating isotopic effects, and testing collisional-radiative models. While spectroscopy with electron beam ion traps had originally focused on the x-ray emission from highly charged ions interacting with the electron beam, the operating modes of such devices have expanded to study radiation in almost all wavelength bands from the visible to the hard x-ray region; and at several facilities the ions can be studied even in the absence of an electron beam. Photon emission after charge exchange or laser excitation has been observed; and the work is no longer restricted to highly charged ions. Much of the experimental capabilities are unique to electron beam ion traps, and the work performed with these devices cannot be undertaken elsewhere. However, in other areas the work on electron beam ion traps rivals the spectroscopy performed with conventional ion traps or heavy-ion storage rings. The examples we present highlight many of the capabilities of the existing electron beam ion traps and their contributions to physics.
1. High gradient lens for charged particle beam
Science.gov (United States)
Chen, Yu-Jiuan
2014-04-29
Methods and devices enable shaping of a charged particle beam. A dynamically adjustable electric lens includes a series of alternating a series of alternating layers of insulators and conductors with a hollow center. The series of alternating layers when stacked together form a high gradient insulator (HGI) tube to allow propagation of the charged particle beam through the hollow center of the HGI tube. A plurality of transmission lines are connected to a plurality of sections of the HGI tube, and one or more voltage sources are provided to supply an adjustable voltage value to each transmission line of the plurality of transmission lines. By changing the voltage values supplied to each section of the HGI tube, any desired electric field can be established across the HGI tube. This way various functionalities including focusing, defocusing, acceleration, deceleration, intensity modulation and others can be effectuated on a time varying basis.
2. Charge dividing mechanism in position-sensitive detectors
International Nuclear Information System (INIS)
1978-01-01
A complete charge-division mechanism, including both the diffusion and the electromagnetic wave propagation on resistive electrodes, is presented. The charge injected into such a transmission line divides between the two ends according to the ratio of resistances and independently of the value of the line resistance, of the propagation mechanism and of the distribution of inductance and capacitance along the line. The shortest charge division time is achieved for Rl = 2π (L/C)/sup 1/2), where R, L, C are resistance, inductance and capacitance per unit length and l is the length of the line
3. Study of Charge Diffusion in a Silicon Detector Using an Energy Sensitive Pixel Readout Chip
CERN Document Server
Schioppa, E. J.; van Beuzekom, M.; Visser, J.; Koffeman, E.; Heijne, E.; Engel, K. J.; Uher, J.
2015-01-01
A 300 μm thick thin p-on-n silicon sensor was connected to an energy sensitive pixel readout ASIC and exposed to a beam of highly energetic charged particles. By exploiting the spectral information and the fine segmentation of the detector, we were able to measure the evolution of the transverse profile of the charge carriers cloud in the sensor as a function of the drift distance from the point of generation. The result does not rely on model assumptions or electric field calculations. The data are also used to validate numerical simulations and to predict the detector spectral response to an X-ray fluorescence spectrum for applications in X-ray imaging.
4. Reset charge sensitive amplifier for NaI(Tl) gamma-ray spectrometer
International Nuclear Information System (INIS)
Zeng, Guoqiang; Tan, Chengjun; Li, Qiang; Ge, Liangquan; Liu, Xiyao; Luo, Qun
2015-01-01
The time constant of the output signal of the front-end readout circuit of a traditional gamma-ray spectrometer with a NaI(Tl)+PMT structure is affected by temperature, measurement environment and the signal transmission cable, so it is difficult to get a good resolution spectrum, especially at higher counting rates. In this paper, a reset charge sensitive amplifier (RCSA) is designed for the gamma-ray spectrometer with a NaI(Tl)+PMT structure. The designed RCSA outputs a step signal, thus enabling the acquisition of double-exponential signals with a stable time constant by using the next stage of a CR differentiating circuit. The designed RCSA is mainly composed of a basic amplifying circuit, a reset circuit and a dark current compensation circuit. It provides the output step signal through the integration of the PMT output charge signal. When the amplitude of the step signal exceeds a preset voltage threshold, it triggers the reset circuit to generate a reset pulse (about 5 µs pulse width) to reset the output signal. Experimental results demonstrated that the designed RCSA achieves a charge sensitivity of 4.26×10 10 V/C, with a zero capacitance noise of 51.09 fC and a noise slope of 1.98 fC/pF. Supported by the digital shaping algorithm of the digital multi-channel analyzer (DMCA), it can maintain good energy resolution with high counting rates up to 150 kcps and with a temperature range from −19 °C to 50 °C. - Highlights: • A new reset type charge sensitive amplifier for gamma-ray spectrometer based on a photomultiplier tube is proposed. • Reset circuit formed by constant current source output a fixed width pulse to reset charge sensitive amplifier. • Photomultiplier tube dark current compensation circuit could increase the pulse through rate by decreasing reset frequency. • This amplifier outputs a step function signal that could match next stage circuit easily
5. High sensitivity amplifier/discriminator for PWC's
International Nuclear Information System (INIS)
Hansen, S.
1983-01-01
The facility support group at Fermilab is designing and building a general purpose beam chamber for use in several locations at the laboratory. This pwc has 128 wires per plane spaced 1 mm apart. An initial production of 25 signal planes is anticipated. In proportional chambers, the size of the signal depends exponentially on the charge stored per unit of length along the anode wire. As the wire spacing decreases, the capacitance per unit length decreases, thereby requiring increased applied voltage to restore the necessary charge per unit length. In practical terms, this phenomenon is responsible for difficulties in constructing chambers with less than 2 mm wire spacing. 1 mm chambers, therefore, are frequently operated very near to their breakdown point and/or a high gain gas containing organic compounds such as magic gas is used. This argon/iso-butane mixture has three drawbacks: it is explosive when exposed to the air, it leaves a residue on the wires after extended use and is costly. An amplifier with higher sensitivity would reduce the problems associated with operating chambers with small wire spacings and allow them to be run a safe margin below their breakdown voltage even with an inorganic gas mixture such as argon/CO2, this eliminating the need to use magic gas. Described here is a low cost amplifier with a usable threshold of less than 0.5 μA. Data on the performance of this amplifier/discriminator in operation on a prototype beam chamber are given. This data shows the advantages of the high sensitivity of this design
6. High speed auto-charging system for condenser bank
International Nuclear Information System (INIS)
Mizuno, Yasunori; Bito, Fumio; Fujita, Kazuhiko; Sometani, Taro
1987-01-01
A current-control type high-speed charging system, which is intended for auto-charging of the condenser bank, is developed. Moreover, the system can also serve to compensate the current leakage from the condenser bank so that the charged voltage can be kept constant. The system consists of a sequence circuit, a charging current control circuit (or auto-charging circuit) and a charging circuit. The auto-charging circuit is characterized by the use of a triac to control the current. The current, controlled by the circuit, is supplied to the condenser bank through a step-up transformer and voltage doubler rectifier circuit. It is demonstrated that the use of the high-speed auto-charging circuit can largely decrease the required charging time, compared to constant voltage charging. In addition, the compensation function is shown to serve effectively for maintaining a constant voltage after the completion of charging. The required charging time is decreases as the charging current increases. The maximum charging current is decided by the rating of the traic and the current rating of the rectifier diode in the secondary circuit. Major components of these circuits have decreased impedances to minimize the effect of noise, so that the possibility of an accident can be eliminated. Other various improvements are made in the grounding circuit and the charging protection circuit in order to ensure safety. (Nogami, K.)
7. Charge-coupled devices as positron sensitive detectors of x-radiation
International Nuclear Information System (INIS)
Volkov, G.S.; Zazhivikhin, V.V.; Zajtsev, V.I.; Mishevskij, V.O.
1996-01-01
Results of theoretical and experimental studies on the sensitivity and spatial resolution of devices with a charge link (CLD) within the X-radiation energy range are described. The areas of the device application are considered
8. Charge migration contribution to the sensitive layer of a silicon detector
International Nuclear Information System (INIS)
Croitoru, N.; Seidman, A.; Rancoita, P.G.
1984-01-01
The charge migration from the field-free region has been investigated, by comparing the expected peak position (which takes into account the depleted layer only) of the energy-loss of relativistic electrons with the measured one. The measurement sensitive layer was found to be systematically larger than the depleted one. This effect is accounted for the charge migration to diffusion
9. Production of High-Intensity, Highly Charged Ions
CERN Document Server
Gammino, S.
2013-12-16
In the past three decades, the development of nuclear physics facilities for fundamental and applied science purposes has required an increasing current of multicharged ion beams. Multiple ionization implies the formation of dense and energetic plasmas, which, in turn, requires specific plasma trapping configurations. Two types of ion source have been able to produce very high charge states in a reliable and reproducible way: electron beam ion sources (EBIS) and electron cyclotron resonance ion sources (ECRIS). Multiple ionization is also obtained in laser-generated plasmas (laser ion sources (LIS)), where the high-energy electrons and the extremely high electron density allow step-by-step ionization, but the reproducibility is poor. This chapter discusses the atomic physics background at the basis of the production of highly charged ions and describes the scientific and technological features of the most advanced ion sources. Particular attention is paid to ECRIS and the latest developments, since they now r...
10. Production, transport and charge capture measurements of highly charged recoil ions
International Nuclear Information System (INIS)
Trebus, U.E.
1989-01-01
An experiment is described to study highly charged recoil ions on-line to the heavy accelerator UNILAC at GSI. The highly charged recoil ions are produced by heavy-ion bombardment of a gas target. Subsequently the slow highly charged recoil ions are extracted from the ionization volume, and guided through a beam transport line to a Wien filter for charge state selection and to a collision region to study charge transfer processes. Several experiments were carried out to show the efficient charge state separation. Charge states up to q = 15 were observed. When using a retarding field analyzer cross sections for single electron capture were determined for different charge states of Xe q+ for q = 4 to 11 and He gas. The experiments demonstrated increasing charge transfer cross sections with increasing charge state q and indicated the effect of near resonant charge capture for q = 6. The flexible data acquisition system used, is described and other future experiments, such as for instance in flight ion-trapping are indicated in the appendix
11. Production, transport and charge capture measurements of highly charged recoil ions
International Nuclear Information System (INIS)
Trebus, U.E.
1989-05-01
An experiment is described to study highly charged recoil ions on-line to the heavy ion accelerator UNILAC at GSI. The highly charged recoil ions are produced by heavy ion bombardment of a gas target. Subsequently the slow highly charged recoil ions are extracted from the ionization volume, and guided through a beam transport line to a Wien filter for charge state selection and to a collision region to study charge transfer processes. Several experiments were carried out to show the efficient charge state separation. Charge states up to q=15 were observed. When using a retarding field analyzer cross sections for single electron capture were determined for different charge states of Xe q+ for q=4 to 11 and He gas. The experiments demonstrated increasing charge transfer cross sections with increasing charge state q and indicated the effect of near resonant charge capture for q=6. The flexible data acquisition system used, is described and other future experiments, such as for instance in flight ion-trapping are indicated in the appendix. (orig.)
12. Sensitivity of charge transport measurements to local inhomogeneities
DEFF Research Database (Denmark)
Koon, Daniel; Wang, Fei; Petersen, Dirch Hjorth
an intuitive, visual explanation for experimental misassignment of carrier type in n-type ZnO and agree with published experimental results for holes in a uniform material. These results simplify calculation and plotting of the sensitivities on an N x N grid from a problem of order N5 to one of order N3...
13. Charge separation sensitized by advanced II-VI semiconductor nanostructures
Energy Technology Data Exchange (ETDEWEB)
Kelley, David F. [Univ.of California, Merced, CA (United States)
2017-04-11
This proposal focuses on how the composition and morphology of pure and alloyed II-VI semiconductor heterostructures control their spectroscopic and dynamical properties. The proposed research will use a combination of synthesis development, electron microscopy, time-resolved electronic spectroscopy and modeling calculations to study these nanostructures. The proposed research will examine the extent to which morphology, compression due to lattice mismatch and alloy effects can be used to tune the electron and hole energies and the spectroscopic properties of II-VI heterojunctions. It will also use synthesis, optical spectroscopy and HRTEM to examine the role of lattice mismatch and hence lattice strain in producing interfacial defects, and the extent to which defect formation can be prevented by controlling the composition profile through the particles and across the interfaces. Finally, we will study the magnitude of the surface roughness in core/shell nanostructures and the role of shell thickness variability on the inhomogeneity of interfacial charge transfer rates.
14. A two-dimensional position sensitive gas chamber with scanned charge transfer readout
Energy Technology Data Exchange (ETDEWEB)
Gomez, F. E-mail: faustgr@usc.es; Iglesias, A.; Lobato, R.; Mosquera, J.; Pardo, J.; Pena, J.; Pazos, A.; Pombar, M.; Rodriguez, A
2003-10-21
We have constructed and tested a two-dimensional position sensitive parallel-plate gas ionization chamber with scanned charge transfer readout. The scan readout method described here is based on the development of a new position-dependent charge transfer technique. It has been implemented by using gate strips perpendicularly oriented to the collector strips. This solution reduces considerably the number of electronic readout channels needed to cover large detector areas. The use of a 25 {mu}m thick kapton etched circuit allows high charge transfer efficiency with a low gating voltage, consequently needing a very simple commutating circuit. The present prototype covers 8x8 cm{sup 2} with a pixel size of 1.27x1.27 mm{sup 2}. Depending on the intended use and beam characteristics a smaller effective pixel is feasible and larger active areas are possible. This detector can be used for X-ray or other continuous beam intensity profile monitoring.
15. A study of charge transfer kinetics in dye-sensitized surface conductivity solar cells
Energy Technology Data Exchange (ETDEWEB)
Friedrich, Dennis
2011-05-15
The efficiency of the quasi-solid-state dye-sensitized solar cell developed by Junghaenel and Tributsch, the so-called Nano Surface Conductivity Solar Cell (NSCSC), was improved from 2% to 3.5% introducing a compact TiO{sub 2} underlayer, modifying the surface of the mesoporous TiO{sub 2} electrode, optimizing the deposition process of the electrolyte film, and replacing the platinum counter electrode by a carbon layer. Space-resolved photocurrent images revealed the importance of a homogeneous distribution of the electrolyte film. An uneven dispersion led to localized areas of high and low photocurrents, whereas the latter were attributed to an insufficient concentration of the redox couple. Impedance spectroscopy was performed on cells containing different concentrations of the redox couple. By modeling the spectra using an equivalent circuit with a transmission line of resistive and capacitive elements, the characteristic parameters of electron transport in the TiO{sub 2}, such as diffusion length and electron lifetime were obtained. The measurements indicated that the transport of the positive charge to the counter electrode is the main process limiting the efficiency of the cells. Excess charge carrier decay in functioning devices was analyzed by contactless transient photoconductance measurements in the microwave frequency range (TRMC). The lifetime of the photogenerated charge carriers was observed to decrease with increasing applied potential, reaching its maximum close to the opencircuit potential of the cell, where the photocurrent density was minimal, i.e. the potential dependent decay observed was limited by the injection of electrons into the front contact. The functioning of this NSCSC indicated that the transport of the positive charge occurs by solid-state diffusion at the surface of the TiO{sub 2} particles. TRMC measurements on subset devices in the form of sensitized TiO{sub 2} layers revealed charge carrier kinetics strongly dependent on the
16. High-Efficiency Solid-State Dye-Sensitized Solar Cells: Fast Charge Extraction through Self-Assembled 3D Fibrous Network of Crystalline TiO 2 Nanowires
KAUST Repository
Tétreault, Nicolas
2010-12-28
Herein, we present a novel morphology for solid-state dye-sensitized solar cells based on the simple and straightforward self-assembly of nanorods into a 3D fibrous network of fused single-crystalline anatase nanowires. This architecture offers a high roughness factor, significant light scattering, and up to several orders of magnitude faster electron transport to reach a near-record-breaking conversion efficiency of 4.9%. © 2010 American Chemical Society.
17. High charge state heavy ion production from a PIG source
International Nuclear Information System (INIS)
Bex, L.; Clark, D.J.; Ellsworth, C.E.; Flood, W.S.; Gough, R.A.; Holley, W.R.; Meriwether, J.R.; Morris, D.
1975-03-01
The comparison of pulsed vs. dc arc operation for nitrogen and argon shows a shift in charge distribution toward the higher charge states for the pulsed case. Tests with various magnetic field shapes along the arc column show a significant increase in high charge state output for a uniform field compared to the case with a field low at the cathodes. (U.S.)
18. Highly-correlated charges in polyelectrolyte gels
Science.gov (United States)
Sing, Charles; Zwanikken, Johannes; Olvera de La Cruz, Monica
2013-03-01
Polyelectrolyte gels are ubiquitous in polymer physics due to their attractive combination of structural and chemical features that permit the realization of environmentally responsive'' systems. The conventional conceptual picture of the volume response of these systems is based on a competition between osmotic and elastic effects. We elaborate on this fundamental understanding by including ion correlations through the use of liquid-state integral equation theory. This allows for a statistical mechanical representation of the state of the system that not only surpasses traditional Poisson-Boltzmann theories but also renders structural features in a highly accurate fashion. In particular, the local ion structure is elucidated, allowing for detailed articulation of charge inversion and condensation effects in the context of gel swelling. The inclusion of correlations has a number of ramifications that become apparent, with enhanced gel collapse and excluded volume competitions that give rise to novel and ion-dependent reentrant swelling effects. We expect this rigorous theory to prove instructive in understanding any number of gelated structures, such as chromosomes or designed synthetic materials for drug delivery.
19. Prospects for charge sensitive amplifiers in scaled CMOS
Science.gov (United States)
O'Connor, Paul; De Geronimo, Gianluigi
2002-03-01
Due to its low cost and flexibility for custom design, monolithic CMOS technology is being increasingly employed in charge preamplifiers across a broad range of applications, including both scientific research and commercial products. The associated detectors have capacitances ranging from a few tens of fF to several hundred pF. Applications call for pulse shaping from tens of ns to tens of μs, and constrain the available power per channel from tens of μW to tens of mW. At the same time a new technology generation, with changed device parameters, appears every 2 years or so. The optimum design of the front-end circuitry is examined taking into account submicron device characteristics, weak inversion operation, the reset system, and power supply scaling. Experimental results from recent prototypes will be presented. We will also discuss the evolution of preamplifier topologies and anticipated performance limits as CMOS technology scales down to the 0.1 μm/1.0 V generation in 2006.
20. Prospects for charge sensitive amplifiers in scaled CMOS
International Nuclear Information System (INIS)
O'Connor, Paul; De Geronimo, Gianluigi
2002-01-01
Due to its low cost and flexibility for custom design, monolithic CMOS technology is being increasingly employed in charge preamplifiers across a broad range of applications, including both scientific research and commercial products. The associated detectors have capacitances ranging from a few tens of fF to several hundred pF. Applications call for pulse shaping from tens of ns to tens of μs, and constrain the available power per channel from tens of μW to tens of mW. At the same time a new technology generation, with changed device parameters, appears every 2 years or so. The optimum design of the front-end circuitry is examined taking into account submicron device characteristics, weak inversion operation, the reset system, and power supply scaling. Experimental results from recent prototypes will be presented. We will also discuss the evolution of preamplifier topologies and anticipated performance limits as CMOS technology scales down to the 0.1 μm/1.0 V generation in 2006
1. Pricing Strategy in Online Retailing Marketplaces of Homogeneous Goods: Should High Reputation Seller Charge More?
Science.gov (United States)
Liu, Yuewen; Wei, Kwok Kee; Chen, Huaping
There are two conflicting streams of research findings on pricing strategy: one is high reputation sellers should charge price premium, while the other is high reputation sellers should charge relatively low price. Motivated by this confliction, this study examines pricing strategy in online retailing marketplace of homogeneous goods. We conduct an empirical study using data collected from a dominant online retailing marketplace in China. Our research results indicate that, in online retailing marketplace of homogeneous goods, high reputation sellers should charge relatively low price, because the consumers of high reputation sellers are more price sensitive than the consumers of low reputation sellers.
2. Copper Complexes with Tetradentate Ligands for Enhanced Charge Transport in Dye-Sensitized Solar Cells
Directory of Open Access Journals (Sweden)
Hannes Michaels
2018-05-01
Full Text Available In dye-sensitized solar cells (DSCs, the redox mediator is responsible for the regeneration of the oxidized dye and for the hole transport towards the cathode. Here, we introduce new copper complexes with tetradentate 6,6′-bis(4-(S-isopropyl-2-oxazolinyl-2,2′-bipyridine ligands, Cu(oxabpy, as redox mediators. Copper coordination complexes with a square-planar geometry show low reorganization energies and thus introduce smaller losses in photovoltage. Slow recombination kinetics of excited electrons between the TiO2 and CuII(oxabpy species lead to an exceptionally long electron lifetime, a high Fermi level in the TiO2, and a high photovoltage of 920 mV with photocurrents of 10 mA∙cm−2 and 6.2% power conversion efficiency. Meanwhile, a large driving force remains for the dye regeneration of the Y123 dye with high efficiencies. The square-planar Cu(oxabpy complexes yield viscous gel-like solutions. The unique charge transport characteristics are attributed to a superposition of diffusion and electronic conduction. An enhancement in charge transport performance of 70% despite the higher viscosity is observed upon comparison of Cu(oxabpy to the previously reported Cu(tmby2 redox electrolyte.
3. Strong-field relativistic processes in highly charged ions
Energy Technology Data Exchange (ETDEWEB)
Postavaru, Octavian
2010-12-08
In this thesis we investigate strong-field relativistic processes in highly charged ions. In the first part, we study resonance fluorescence of laser-driven highly charged ions in the relativistic regime by solving the time-dependent master equation in a multi-level model. Our ab initio approach based on the Dirac equation allows for investigating highly relativistic ions, and, consequently, provides a sensitive means to test correlated relativistic dynamics, bound-state quantum electrodynamic phenomena and nuclear effects by applying coherent light with x-ray frequencies. Atomic dipole or multipole moments may be determined to unprecedented accuracy by measuring the interference-narrowed fluorescence spectrum. Furthermore, we investigate the level structure of heavy hydrogenlike ions in laser beams. Interaction with the light field leads to dynamic shifts of the electronic energy levels, which is relevant for spectroscopic experiments. We apply a fully relativistic description of the electronic states by means of the Dirac equation. Our formalism goes beyond the dipole approximation and takes into account non-dipole effects of retardation and interaction with the magnetic field components of the laser beam. We predicted cross sections for the inter-shell trielectronic recombination (TR) and quadruelectronic recombination processes which have been experimentally confirmed in electron beam ion trap measurements, mainly for C-like ions, of Ar, Fe and Kr. For Kr{sup 30}+, inter-shell TR contributions of nearly 6% to the total resonant photorecombination rate were found. (orig.)
4. Irradiation of graphene field effect transistors with highly charged ions
Energy Technology Data Exchange (ETDEWEB)
Ernst, P.; Kozubek, R.; Madauß, L.; Sonntag, J.; Lorke, A.; Schleberger, M., E-mail: marika.schleberger@uni-due.de
2016-09-01
In this work, graphene field-effect transistors are used to detect defects due to irradiation with slow, highly charged ions. In order to avoid contamination effects, a dedicated ultra-high vacuum set up has been designed and installed for the in situ cleaning and electrical characterization of graphene field-effect transistors during irradiation. To investigate the electrical and structural modifications of irradiated graphene field-effect transistors, their transfer characteristics as well as the corresponding Raman spectra are analyzed as a function of ion fluence for two different charge states. The irradiation experiments show a decreasing mobility with increasing fluences. The mobility reduction scales with the potential energy of the ions. In comparison to Raman spectroscopy, the transport properties of graphene show an extremely high sensitivity with respect to ion irradiation: a significant drop of the mobility is observed already at fluences below 15 ions/μm{sup 2}, which is more than one order of magnitude lower than what is required for Raman spectroscopy.
5. High Intensity High Charge State ECR Ion Sources
CERN Document Server
Leitner, Daniela
2005-01-01
The next-generation heavy ion beam accelerators such as the proposed Rare Isotope Accelerator (RIA), the Radioactive Ion Beam Factory at RIKEN, the GSI upgrade project, the LHC-upgrade, and IMP in Lanzhou require a great variety of high charge state ion beams with a magnitude higher beam intensity than currently achievable. High performance Electron Cyclotron Resonance (ECR) ion sources can provide the flexibility since they can routinely produce beams from hydrogen to uranium. Over the last three decades, ECR ion sources have continued improving the available ion beam intensities by increasing the magnetic fields and ECR heating frequencies to enhance the confinement and the plasma density. With advances in superconducting magnet technology, a new generation of high field superconducting sources is now emerging, designed to meet the requirements of these next generation accelerator projects. The talk will briefly review the field of high performance ECR ion sources and the latest developments for high intens...
6. Charge-sensitive poly-silicon TFT amplifiers for a-Si:H pixel particle detectors
International Nuclear Information System (INIS)
Cho, G.; Perez-Mendez, V.; Hack, M.; Lewis, A.
1992-04-01
Prototype charge-sensitive poly-Si TFT amplifiers have been made for the amplification of signals (from an a-Si:H pixel diode used as an ionizing particle detector). They consist of a charge-sensitive gain stage, a voltage gain stage and a source follower output stage. The gain-bandwidth product of the amplifier is ∼ 300 MHz. When the amplifier is connected to a pixel detector of 0.2 pF, it gives a charge-to-voltage gain of ∼ 0.02 mV/electrons with a pulse rise time less than 100 nsec. An equivalent noise charge of the front-end TFT is ∼ 1000 electrons for a shaping time of 1 μsec
7. Plan charge exchange scattering at high energies
International Nuclear Information System (INIS)
Saleem, M.; Bhatti, S.; Fazal-e-Aleem; Rafique, M.
1980-01-01
By a phenomenological choice of the residue functions, a very good fit with experiment for the pion-nucleon charge exchange reaction at Fermilab energies is obtained on a simple Regge-pole model using a quadratic rho trajectory and energy-independent parameters
8. Timing performances of diamond detectors with Charge Sensitive Amplifier readout
CERN Document Server
Berretti, M; Minafra, N
2015-01-01
Research on particle detector based on synthetic diamonds has always been limited by the cost, quality and availability of the sensitive material. Moreover, the read-out electronics requires particular care due to the small number of electron/hole pairs generated by the passage of a minimum ionizing particle. However, high radiation hardness, low leakage currents and high mobility of the electron/hole pairs make them an attractive solution for the time of flight measurements and the beam monitoring of new high energy physics experiments where the severe radiation environment is a limitation for most of the technologies commonly used in particle detection. In this work we report the results on the timing performance of a 4.5x4.5 mm$^{2}$ scCVD sensor read-out using a charge sensitive amplifier. Both sensors and amplifiers have been purchased from CIVIDEC Instrumentation. The measurement have been performed on minimum ionizing pions in two beam tests at the PSI and CERN-PS facilities with two different detec...
9. High sensitivity thermal sensors on insulating diamond
Energy Technology Data Exchange (ETDEWEB)
Job, R. [Fernuniversitaet Hagen (Gesamthochschule) (Germany). Electron. Devices; Denisenko, A.V. [Fernuniversitaet Hagen (Gesamthochschule) (Germany). Electron. Devices; Zaitsev, A.M. [Fernuniversitaet Hagen (Gesamthochschule) (Germany). Electron. Devices; Melnikov, A.A. [Belarussian State Univ., Minsk (Belarus). HEII and FD; Werner, M. [VDI/VDE-IT, Teltow (Germany); Fahrner, W.R. [Fernuniversitaet Hagen (Gesamthochschule) (Germany). Electron. Devices
1996-12-15
Diamond is a promising material to develop sensors for applications in harsh environments. To increase the sensitivity of diamond temperature sensors the effect of thermionic hole emission (TE) over an energetic barrier formed in the interface between highly boron-doped p-type and intrinsic insulating diamond areas has been suggested. To study the TE of holes a p-i-p diode has been fabricated and analyzed by electrical measurements in the temperature range between 300 K and 700 K. The experimental results have been compared with numerical simulations of its electrical characteristics. Based on a model of the thermionic emission of carriers into an insulator it has been suggested that the temperature sensitivity of the p-i-p diode on diamond is strongly affected by the re-emission of holes from a group of donor-like traps located at a level of 0.7-1.0 eV above the valence band. The mechanism of thermal activation of the current includes a spatial redistribution of the potential, which results in the TE regime from a decrease of the immobilized charge of the ionized traps within the i-zone of the diode and the correspondent lowering of the forward biased barrier. The characteristics of the p-i-p diode were studied with regard to temperature sensor applications. The temperature coefficient of resistance (TCR=-0.05 K{sup -1}) for temperatures above 600 K is about four times larger than the maximal attainable TCR for conventional boron-doped diamond resistors. (orig.)
10. Space-charge compensation of highly charged ion beam from laser ion source
International Nuclear Information System (INIS)
Kondrashev, S.A.; Collier, J.; Sherwood, T.R.
1996-01-01
The problem of matching an ion beam delivered by a high-intensity ion source with an accelerator is considered. The experimental results of highly charged ion beam transport with space-charge compensation by electrons are presented. A tungsten thermionic cathode is used as a source of electrons for beam compensation. An increase of ion beam current density by a factor of 25 is obtained as a result of space-charge compensation at a distance of 3 m from the extraction system. The process of ion beam space-charge compensation, requirements for a source of electrons, and the influence of recombination losses in a space-charge-compensated ion beam are discussed. (author)
11. Highly charged ion based time-of-flight emission microscope
International Nuclear Information System (INIS)
Hamza, Alex V.; Barnes, Alan V.; Magee, Ed; Newman, Mike; Schenkel, Thomas; McDonald, Joseph W.; Schneider, Dieter H.
2000-01-01
An emission microscope using highly charged ions as the excitation source has been designed, constructed, and operated. A novel ''acorn'' objective lens has been used to simultaneously image electron and secondary ion emission. A resistive anode-position sensitive detector is used to determine the x-y position and time of arrival of the secondary events at the microscope image plane. Contrast in the image can be based on the intensity of the electron emission and/or the presence of particular secondary ions. Spatial resolution of better than 1 μm and mass resolution m/Δm of better than 400 were demonstrated. Background rejection from uncorrelated events of greater than an order of magnitude is also achieved. (c) 2000 American Institute of Physics
International Nuclear Information System (INIS)
Agakhanyan, T.M.
1998-01-01
The methodology for designing charge-sensitive preamplifiers on the low-noise analog integral circuits, including all the stages: the mathematical synthesis with optimization of the intermediate function; the scheme-technical synthesis with parametric optimization of the scheme and analysis of draft projects with the parameter verification is presented. The designing is conducted on the basis of requirements for signal parameters and noise indices of the preamplifier. The system of automated designing of the charge-sensitive preamplifiers on the low-noise analog integral circuits is developed [ru
13. Charge collection and absorption-limited x-ray sensitivity of pixellated x-ray detectors
International Nuclear Information System (INIS)
Kabir, M. Zahangir; Kasap, S.O.
2004-01-01
The charge collection and absorption-limited x-ray sensitivity of a direct conversion pixellated x-ray detector operating in the presence of deep trapping of charge carriers is calculated using the Shockley-Ramo theorem and the weighting potential of the individual pixel. The sensitivity of a pixellated x-ray detector is analyzed in terms of normalized parameters; (a) the normalized x-ray absorption depth (absorption depth/photoconductor thickness), (b) normalized pixel width (pixel size/thickness), and (c) normalized carrier schubwegs (schubweg/thickness). The charge collection and absorption-limited sensitivity of pixellated x-ray detectors mainly depends on the transport properties (mobility and lifetime) of the charges that move towards the pixel electrodes and the extent of dependence increases with decreasing normalized pixel width. The x-ray sensitivity of smaller pixels may be higher or lower than that of larger pixels depending on the rate of electron and hole trapping and the bias polarity. The sensitivity of pixellated detectors can be improved by ensuring that the carrier with the higher mobility-lifetime product is drifted towards the pixel electrodes
14. Cold highly charged ions in a cryogenic Paul trap
Energy Technology Data Exchange (ETDEWEB)
Versolato, O. O., E-mail: oscar.versolato@mpi-hd.mpg.de; Schwarz, M.; Windberger, A.; Ullrich, J. [Max-Planck-Institut fuer Kernphysik (Germany); Schmidt, P. O. [Physikalisch-Technische Bundesanstalt (Germany); Drewsen, M. [University of Aarhus, Department of Physics and Astronomy (Denmark); Crespo Lopez-Urrutia, J. R. [Max-Planck-Institut fuer Kernphysik (Germany)
2013-03-15
Narrow optical transitions in highly charged ions (HCIs) are of particular interest for metrology and fundamental physics, exploiting the high sensitivity of HCIs to new physics. The highest sensitivity for a changing fine structure constant ever predicted for a stable atomic system is found in Ir{sup 17 + }. However, laser spectroscopy of HCIs is hindered by the large ({approx} 10{sup 6} K) temperatures at which they are produced and trapped. An unprecedented improvement in such laser spectroscopy can be obtained when HCIs are cooled down to the mK range in a linear Paul trap. We have developed a cryogenic linear Paul trap in which HCIs will be sympathetically cooled by {sup 9}Be{sup + } ions. Optimized optical access for laser light is provided while maintaining excellent UHV conditions. The Paul trap will be connected to an electron beam ion trap (EBIT) which is able to produce a wide range of HCIs. This EBIT will also provide the first experimental input needed for the determination of the transition energies in Ir{sup 17 + }, enabling further laser-spectroscopic investigations of this promising HCI.
15. Two-dimensional position sensitive silicon photodiode as a charged particle detector
International Nuclear Information System (INIS)
1999-01-01
A two-dimensional position sensitive silicon photodiode has been tested for measurement of position and energy of charged particles. Position nonlinearity and resolution, as well as energy resolution and ballistic deficit were measured for 5.486 MeV α-particles. The results obtained for different pulse shaping time constants are presented
16. The application of Multisim software to the analyzing of the charge-sensitive preamplifier
International Nuclear Information System (INIS)
Zhou Chao; Zhao Xiuliang; Yin Chenyan
2007-01-01
This paper told the usage of Multisim software in simulating and analyzing a charge-sensitive preamplifier which is a typical circuit in nuclear electronics. At the foundation of theoretic analysis, some basic characteristic were simulated and analyzed. The simulation result was obtained according with the academic result which have very assistant and reference value on theoretic analysis. (authors)
17. Sensitive and direct determination of lithium by mixed-mode chromatography and charged aerosol detection.
Science.gov (United States)
Dai, Lulu; Wigman, Larry; Zhang, Kelly
2015-08-21
A sensitive analytical method using mixed mode HPLC separation coupled with charged aerosol detection (CAD) was developed for quantitative analysis of lithium. The method is capable of separating lithium ion from different drug matrices and other ions in a single run thus eliminating the organic matrix and ionic analyte interferences without extensive sample preparation such as derivatization and extraction. The separation space and chromatographic conditions are defined by systematic studies of the retention behaviors of lithium and potential interfering ions and different type of pharmaceutical APIs (active pharmaceutical ingredients) under reversed-phase, HILIC and cation/anion exchange mechanisms. Compared to other current analytical techniques for lithium analysis, the presented method provides a new approach and demonstrates high sensitivity (0.02ng for LOD and 0.08ng for LOQ in both standard and sample solution). The method has been validated for pharmaceutical samples and can be potentially applied to biological, food and environmental samples. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.
18. Concept for high-charge-state ion induction accelerators
International Nuclear Information System (INIS)
Logan, B.G.; Perry, M.D.; Caporaso, G.J.
1996-01-01
This work describes a particular concept for ion induction linac accelerators using high-charge-state ions produced by an intense, short pulse laser, and compares the costs of a modular driver system producing 6.5 MJ for a variety of ion masses and charge states using a simple but consistent cost model
19. Charged dust in planetary magnetospheres: Hamiltonian dynamics and numerical simulations for highly charged grains
Science.gov (United States)
Schaffer, L.; Burns, J. A.
1994-01-01
We use a combination of analytical and numerical methods to investigate the dynamics of charged dust grains in planetary magnetospheres. Our emphasis is on obtaining results valid for particles that are not necessarily dominated either by gravitational or electromagnetic forces. A Hamiltonian formulation of the problem yields exact results, for all values of charge-to-mass ratio, when we introduce two constraints: particles remain in the equatorial plane and the magnetic field is taken as axially symmetric. In particular, we obtain locations of equilibrium points, the frequencies of stable periodic orbits, the topology of separatrices in phase space, and the rate of longitudinal drift. These results are significant for specific applications: motion in the nearly aligned dipolar field of Saturn, and the trajectories of arbitrarily charged particles in complex magnetic fields for limited periods of time after ejection from parent bodies. Since the model is restrictive, we also use numerical integrations of the full three-dimensional equations of motion and illustrate under what conditions the constrained problem yields reasonable results. We show that a large fraction of the intermediately charged and highly charged (gyrating) particles will always be lost to a planet's atmosphere within a few hundred hours, for motion through tilted-dipole magnetic fields. We find that grains must have a very high charge-to-mass ratio in order to be mirrored back to the ring plane. Thus, except perhaps at Saturn where the dipole tilt is very small, the likely inhabitants of the dusty ring systems are those particles that are either nearly Keplerian (weakly charged) grains or grains whose charges place them in the lower end of the intermediate charge zone. Fianlly, we demonstrate the effect of plasma drag on the orbits of gyrating particles to be a rapid decrease in gyroradius followed by a slow radial evolution of the guiding center.
20. Quantum dot sensitized solar cells: Light harvesting versus charge recombination, a film thickness consideration
Science.gov (United States)
Wang, Xiu Wei; Wang, Ye Feng; Zeng, Jing Hui; Shi, Feng; Chen, Yu; Jiang, Jiaxing
2017-08-01
Sensitizer loading level is one of the key factors determined the performance of sensitized solar cells. In this work, we systemically studied the influence of photo-anode thicknesses on the performance of the quantum-dot sensitized solar cells. It is found that the photo-to-current conversion efficiency enhances with increased film thickness and peaks at around 20 μm. The optimal value is about twice as large as the dye counterparts. Here, we also uncover the underlying mechanism about the influence of film thickness over the photovoltaic performance of QDSSCs from the light harvesting and charge recombination viewpoint.
1. A high charge state heavy ion beam source for HIF
International Nuclear Information System (INIS)
Eylon, S.; Henestroza, E.
1995-04-01
A high current low emittance high charge state heavy ion beam source is being developed. This is designed to deliver HIF (heavy ion fusion) driver accelerator scale beam. Using high-charge-state beam in a driver accelerator for HIF may increase the acceleration efficiency, leading to a reduction in the driver accelerator size and cost. The proposed source system which consists of the gas beam electron stripper followed by a high charge state beam separator, can be added to existing single charge state, low emittance, high brightness ion sources and injectors. We shall report on the source physics design using 2D beam envelope simulations and experimental feasibility studies' results using a neutral gas stripper and a beam separator at the exit of the LBL 2 MV injector
2. Compensation of the detector capacitance presented to charge-sensitive preamplifiers using the Miller effect
Energy Technology Data Exchange (ETDEWEB)
Kwon, Inyong, E-mail: iykwon@umich.edu [University of Michigan, Ann Arbor, MI (United States); Kang, Taehoon, E-mail: thnkang@umich.edu [University of Michigan, Ann Arbor, MI (United States); Wells, Byron T., E-mail: wells@galtresearch.com [Galt LLC, Ypsilanti, MI (United States); D’Aries, Lawrence J., E-mail: lawrence.j.daries.civ@mail.mil [Picatinny Arsenal, Rockaway Township, NJ (United States); Hammig, Mark D., E-mail: hammig@umich.edu [University of Michigan, Ann Arbor, MI (United States)
2015-06-01
This paper describes an integrated circuit design for a modified charge-sensitive amplifier (CSA) that compensates for the effect of capacitance presented by nuclear radiation detectors and other sensors. For applications that require large area semiconductor detectors or for those semiconductor sensors derived from high permittivity materials such as PbSe, the detector capacitance can degrade the system gain and bandwidth of a front-end preamplifier, resulting in extended rise times and attenuated output voltage signals during pulse formation. In order to suppress the effect of sensor capacitance, we applied a bootstrap technique into a traditional CSA. The technique exploits the Miller effect by reducing the effective voltage difference between the two sides of a radiation detector which minimizes the capacitance presented to the differential common-source amplifier. This new configuration is successfully designed to produce effective gain even at high detector capacitance. The entire circuit, including a core CSA with feedback components and a bootstrap amplifier, are implemented in a 0.18 μm CMOS process with a 3.3 V supply voltage. - Highlights: • A modified CSA was implemented for detector capacitance compensation. • Increasing detector capacitance degrades gain and rise time. • A bootstrap amplifier exploiting the Miller effect is described. • It allows using large area radiation sensors for high radiation-interaction rates. • Intensive noise analyses show that SNR is much better with the technique.
3. Charge ordering phenomena in high temperature superconductors
International Nuclear Information System (INIS)
Tassini, Leonardo; Prestel, Wolfgang; Hackl, Rudi; Erb, Andreas; Lambacher, Michael
2007-01-01
The electronic Raman effect has been studied in single crystals of Y 1-x Ca x Ba 2 Cu 3 O 6 (Y-123) and La 2-x Sr x CuO 4 (LSCO) at different doping. The experimental results provide evidences of an anomalous contribution to the response at low energies and temperatures. In LSCO the additional excitation is in B 2g symmetry for x = 0.02 and in B 1g symmetry for x = 0.10. In Y-123, we observed the additional feature in B 2g symmetry at 1.5% doping. Mainly on the basis of the selection rules we conclude that the additional peaks are the response of a dynamical charge modulation (stripes) in the two-dimensional CuO 2 planes. The selection rules allow us to determine the orientation of the stripes to be along the diagonal of the CuO 2 planes in Y-123 and LSCO at x = 0.02, and along the principal axes in LSCO at x = 0.10
4. Low noise charge sensitive preamplifier DC stabilized without a physical resistor
Science.gov (United States)
Bertuccio, Giuseppe; Rehak, Pavel; Xi, Deming
1994-09-13
The invention is a novel charge sensitive preamplifier (CSP) which has no resistor in parallel with the feedback capacitor. No resetting circuit is required to discharge the feedback capacitor. The DC stabilization of the preamplifier is obtained by means of a second feedback loop between the preamplifier output and the common base transistor of the input cascode. The input transistor of the preamplifier is a Junction Field Transistor (JFET) with the gate-source junction forward biased. The detector leakage current flows into this junction. This invention is concerned with a new circuit configuration for a charge sensitive preamplifier and a novel use of the input Field Effect Transistor of the CSP itself. In particular this invention, in addition to eliminating the feedback resistor, eliminates the need for external devices between the detector and the preamplifier, and it eliminates the need for external circuitry to sense the output voltage and reset the CSP. Furthermore, the noise level of the novel CSP is very low, comparable with the performance achieved with other solutions. Experimental tests prove that this configuration for the charge sensitive preamplifier permits an excellent noise performance at temperatures including room temperature. An equivalent noise charge of less than 20 electrons r.m.s. has been measured at room temperature by using a commercial JFET as input device of the preamplifier.
5. Improvement of highly charged ion output from an ECR source
International Nuclear Information System (INIS)
Shirkov, G.D.
1995-01-01
The physical limitations of the highly charged ion production in the ECR source is analyzed in this report. General methods to increase the output ion current and the attainable charged states of heavy ions are discussed. Some new ways to improve the output of highly charged ions from the ECR source for heavy ions are proposed. A new library of computer codes for the mathematical simulation of heavy ion production in the ECR ion source is used for numerical experiments to test these ways for improving the operation of the ECR source. (orig.)
6. A high sensitivity nanomaterial based SAW humidity sensor
Energy Technology Data Exchange (ETDEWEB)
Wu, T-T; Chou, T-H [Institute of Applied Mechanics, National Taiwan University, Taipei 106, Taiwan (China); Chen, Y-Y [Department of Mechanical Engineering, Tatung University, Taipei 104, Taiwan (China)], E-mail: wutt@ndt.iam.ntu.edu.tw
2008-04-21
In this paper, a highly sensitive humidity sensor is reported. The humidity sensor is configured by a 128{sup 0}YX-LiNbO{sub 3} based surface acoustic wave (SAW) resonator whose operating frequency is at 145 MHz. A dual delay line configuration is realized to eliminate external temperature fluctuations. Moreover, for nanostructured materials possessing high surface-to-volume ratio, large penetration depth and fast charge diffusion rate, camphor sulfonic acid doped polyaniline (PANI) nanofibres are synthesized by the interfacial polymerization method and further deposited on the SAW resonator as selective coating to enhance sensitivity. The humidity sensor is used to measure various relative humidities in the range 5-90% at room temperature. Results show that the PANI nanofibre based SAW humidity sensor exhibits excellent sensitivity and short-term repeatability.
7. Monolithic junction field-effect transistor charge preamplifier for calorimetry at high luminosity hadron colliders
International Nuclear Information System (INIS)
Radeka, V.; Rescia, S.; Rehn, L.A.; Manfredi, P.F.; Speziali, V.
1991-11-01
The outstanding noise and radiation hardness characteristics of epitaxial-channel junction field-effect transistors (JFET) suggest that a monolithic preamplifier based upon them may be able to meet the strict specifications for calorimetry at high luminosity colliders. Results obtained so far with a buried layer planar technology, among them an entire monolithic charge-sensitive preamplifier, are described
8. Charge state distributions from highly charged ions channeled at a metal surface
International Nuclear Information System (INIS)
Folkerts, L.; Meyer, F.W.; Schippers, S.
1994-01-01
The vast majority of the experimental work in the field of multicharged ion-surface interactions, to date, has focused on x-ray and particularly on electron emission. These experiments include measurements of the total electron yield, the emission statistics of the electrons, and, most of all, the electron energy distributions. So far, little attention has been paid to the fate of the multicharged projectile ions after the scattering. To our knowledge, the only measurement of the charge state distribution of the scattered ions is the pioneering experiment of de Zwart et al., who measured the total yield of scattered 1+, 2+, and 3+ ions as a function of the primary charge state q (q = 1--11) for 20 key Ne, Ar, and Kr ions after reflection from a polycrystalline tungsten target. Their main finding is the sudden onset of scattered 3+ ions when inner-shell vacancies are present in the primary particles. This suggests that a certain fraction of the inner-shell vacancies survives the entire collision event, and decays via autoionization on the outgoing path. Since the projectiles scattered in the neutral charge state could not be detected in the experiment of de Zwart et al., they were not able to provide absolute charge state fractions. In our present experiment, we focus on the scattered projectiles, measuring both the final charge state and the total scattering angle with a single 2D position sensitive detector (PSD). This method gives us the number of positive, as well as neutral and negative, scattered ions, thus allowing us to extract absolute charge state fractions. Using a well-prepared single Au(110) crystal and a grazing incidence geometry, we were able to observe surface channeling along the [001] channels
9. Probing the vacuum with highly charged ions
International Nuclear Information System (INIS)
Bottcher, C.; Strayer, M.R.
1987-01-01
The physics of the Fermion vacuum is briefly described, and applied to pair production in heavy ion collisions. We consider in turn low energies (<50 MeV/nucleon), intermediate energies (<5 GeV/nucleon), and ultrahigh energies such as would be produced in a ring collider. At high energies, interesting questions of Lorentz and gauge invariance arise. Finally, some applications to the structure of high Z atoms are examined. 14 refs., 11 figs
10. Charge exchange processes of high energy heavy ions channeled in crystals
International Nuclear Information System (INIS)
Andriamonje, S.; Dural, J.; Toulemonde, M.; Groeneveld, K.O.; Maier, R.; Quere, Y.
1990-01-01
The interaction of moving ions with single crystals is very sensitive to the orientation of the incident beam with respect to the crystalline directions of the target. The experiments show that high energy heavy ion channeling deeply modifies the slowing down and charge exchange processes. In this review, we describe the opportunity offered by channeling conditions to study the charge exchange processes. Some aspects of the charge exchange processes with high energy channeled heavy ions are selected from the extensive literature published over the past few years on this subject. Special attention is given to the work performed at the GANIL facility on the study of Radiative Electron Capture (REG), Electron Impact Ionisation (EII), and convoy electron emission. Finally we emphasize the interest of studying resonant charge exchange processes such as Resonant Coherent Excitation (RCE), Resonant Transfer and Excitation (RTE) or Dielectronic Recombination (DR) and the recently proposed Nuclear Excitation by Electron Capture (NEEC)
11. Atomic physics with highly charged ions
International Nuclear Information System (INIS)
Richard, P.
1991-08-01
This report discusses: One electron outer shell processes in fast ion-atom collisions; role of electron-electron interaction in two-electron processes; multi-electron processes at low energy; multi-electron processes at high energy; inner shell processes; molecular fragmentation studies; theory; and, JRM laboratory operations
12. Fast neutron detection using a new pulse shape discrimination technique: Charge sensitive integration
International Nuclear Information System (INIS)
Zucker, M.; Tsoupas, N.; Karwowski, H.; Castaneda, C.; Nimnual, S.; Porter, R.; Ward, T.
1988-01-01
A new electronic technique that depends on charge sensitive integration (CSI) has been developed and tested using a CAMAC based pulse shape discrimination system. Neutrons are well separated from γ-ray signals in the 0.1-100 MeV energy range. The new method was compared with the old zero-crossing time-to-amplitude differentiating technique and was found to be comparable in count rate and superior in noise suppression
13. A low noise charge sensitive amplifier for use in vacuum photo diode readout
International Nuclear Information System (INIS)
Stephenson, R.
1982-08-01
The amplifier described consists of a charge sensitive pre-amplifier optimised for low noise with low values of input shunt capacitance, and a shaping amplifier providing both differentiation and integration. Amplifier gain is adjustable up to a maximum of approximately 100 μV/electron with a rise time of 2 μS to the peak of the output voltage, and with an open circuit input noise level of 150 electrons RMS. (author)
14. Charge-sensitive and shaping amplifier microassemblies for dosimetry and spectrometry on CZT-detectors
International Nuclear Information System (INIS)
Perevertaylo, V.L.; Zaitsevsky, I.L.; Tarasenko, L.I.; Perevertaylo, A.V.; Shkirenko, E.A.
2012-01-01
Developments of new spectrometric channel electronics on the basis of microassemblies, which allowed to reduce the noise and increase of signal-to-noise ratio, lowering power consumption and dimensions. The complete line of front-end electronics for CZT detectors implemented as micro-assemblies is described, the design concept, operation details and application features of charge sensitive amplifier and shaping amplifier microassemblies are discussed, and the results obtained when registering low energy X-ray spectra are shown. It has a high energy resolution δE at the level of the leading companies. For direct detection with silicon p-i-n-diode new electronic channel can resolve 241 Am peaks up to 8 keV with a resolution of about 2 keV at room temperature. New electronics is universal and can be used with different semiconductor detectors - Si, CdZnTe, Scintillator-photodiode, as shown in the spectra. Low power consumption and reduced dimensions allows the using in portable equipment. Manufacturability of micro assembly opens up the possibility for mass production and low cost opens up the possibility to supply them with detectors as S tart kit f or the construction of radiometric and spectrometric devices
15. Theoretical rationalization for reduced charge recombination in bulky carbazole-based sensitizers in solar cells.
Science.gov (United States)
Surakhot, Yaowarat; Laszlo, Viktor; Chitpakdee, Chirawat; Promarak, Vinich; Sudyoadsuk, Taweesak; Kungwan, Nawee; Kowalczyk, Tim; Irle, Stephan; Jungsuttiwong, Siriporn
2017-05-05
The search for greater efficiency in organic dye-sensitized solar cells (DSCs) and in their perovskite cousins is greatly aided by a more complete understanding of the spectral and morphological properties of the photoactive layer. This investigation resolves a discrepancy in the observed photoconversion efficiency (PCE) of two closely related DSCs based on carbazole-containing D-π-A organic sensitizers. Detailed theoretical characterization of the absorption spectra, dye adsorption on TiO 2 , and electronic couplings for charge separation and recombination permit a systematic determination of the origin of the difference in PCE. Although the two dyes produce similar spectral features, ground- and excited-state density functional theory (DFT) simulations reveal that the dye with the bulkier donor group adsorbs more strongly to TiO 2 , experiences limited π-π aggregation, and is more resistant to loss of excitation energy via charge recombination on the dye. The effects of conformational flexibility on absorption spectra and on the electronic coupling between the bright exciton and charge-transfer states are revealed to be substantial and are characterized through density-functional tight-binding (DFTB) molecular dynamics sampling. These simulations offer a mechanistic explanation for the superior open-circuit voltage and short-circuit current of the bulky-donor dye sensitizer and provide theoretical justification of an important design feature for the pursuit of greater photocurrent efficiency in DSCs. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.
16. Charge collection and charge pulse formation in highly irradiated silicon planar detectors
International Nuclear Information System (INIS)
Dezillie, B.; Li, Z.; Eremin, V.
1998-06-01
The interpretation of experimental data and predictions for future experiments for high-energy physics have been based on conventional methods like capacitance versus voltage (C-V) measurements. Experiments carried out on highly irradiated detectors show that the kinetics of the charge collection and the dependence of the charge pulse amplitude on the applied bias are deviated too far from those predicted by the conventional methods. The described results show that in highly irradiated detectors, at a bias lower than the real full depletion voltage (V fd ), the kinetics of the charge collection (Q) contains a fast and a slow component. At V = V fd *, which is the full depletion voltage traditionally determined by the extrapolation of the fast component amplitude of q versus bias to the maximum value or from the standard C-V measurements, the pulse has a slow component with significant amplitude. This slow component can only be eliminated by applying additional bias that amounts to the real full depletion voltage (V fd ) or more. The above mentioned regularities are explained in this paper in terms of a model of an irradiated detector with multiple regions. This model allows one to use C-V, in a modified way, as well as TChT (transient charge technique) measurements to determine the V fd for highly irradiated detectors
17. Ionization of water clusters by fast Highly Charged Ions: Stability, fragmentation, energetics and charge mobility
International Nuclear Information System (INIS)
Legendre, S; Maisonny, R; Capron, M; Bernigaud, V; Cassimi, A; Gervais, B; Grandin, J-P; Huber, B A; Manil, B; Rousseau, P; Tarisien, M; Adoui, L; Lopez-Tarifa, P; AlcamI, M; MartIn, F; Politis, M-F; Penhoat, M A Herve du; Vuilleumier, R; Gaigeot, M-P; Tavernelli, I
2009-01-01
We study dissociative ionization of water clusters by impact of fast Ni ions. Cold Target Recoil Ion Momentum Spectroscopy (COLTRIMS) is used to obtain information about stability, energetics and charge mobility of the ionized clusters. An unusual stability of the (H 2 O) 4 H ''+ ion is observed, which could be the signature of the so called ''Eigen'' structure in gas phase water clusters. High charge mobility, responsible for the formation of protonated water clusters that dominate the mass spectrum, is evidenced. These results are supported by CPMD and TDDFT simulations, which also reveal the mechanisms of such mobility.
18. Strong charge state dependence of H+ and H2+ sputtering induced by slow highly charged ions
International Nuclear Information System (INIS)
Kakutani, N.; Azuma, T.; Yamazaki, Y.; Komaki, K.; Kuroki, K.
1995-01-01
Secondary ion emission has been studied for very slow ( similar 0.01ν B ) highly charged Ar and N ions bombarding C 60 containing hydrogen as an impurity. It is found that the fragmentations of C 60 are very rare even for Ar 16+ bombardments. On the other hand, the sputtering of H + and H 2 + has been observed to increase drastically as a function of incident charge q like q γ (e.g., γ similar 4.6 for H + sputtering by 500 eV Ar q+ ). (orig.)
19. Charge collection and pore filling in solid-state dye-sensitized solar cells
International Nuclear Information System (INIS)
Snaith, Henry J; Humphry-Baker, Robin; Chen, Peter; Zakeeruddin, Shaik M; Graetzel, Michael; Cesar, Ilkay
2008-01-01
The solar to electrical power conversion efficiency for dye-sensitized solar cells (DSCs) incorporating a solid-state organic hole-transporter can be over 5%. However, this is for devices significantly thinner than the optical depth of the active composites and by comparison to the liquid electrolyte based DSCs, which exhibit efficiencies in excess of 10%, more than doubling of this efficiency is clearly attainable if all the steps in the photovoltaic process can be optimized. Two issues are currently being addressed by the field. The first aims at enhancing the electron diffusion length by either reducing the charge recombination or enhancing the charge transport rates. This should enable a larger fraction of photogenerated charges to be collected. The second, though less actively investigated, aims to improve the physical composite formation, which in this instance is the infiltration of mesoporous TiO 2 with the organic hole-transporter 2,2',7,7'-tetrakis(N,N-di-p-methoxypheny-amine)-9,9'-spirobifluorene (spiro-MeOTAD). Here, we perform a broad experimental study to elucidate the limiting factors to the solar cell performance. We first investigate the charge transport and recombination in the solid-state dye-sensitized solar cell under realistic working conditions via small perturbation photovoltage and photocurrent decay measurements. From these measurements we deduce that the electron diffusion length near short-circuit is as long as 20 μm. However, at applied biases approaching open-circuit potential under realistic solar conditions, the diffusion length becomes comparable with the film thickness, ∼2 μm, illustrating that real losses to open-circuit voltage, fill factor and hence efficiency are occurring due to ineffective charge collection. The long diffusion length near short-circuit, on the other hand, illustrates that another process, separate from ineffective charge collection, is rendering the solar cell less than ideal. We investigate the process
20. Charge collection and pore filling in solid-state dye-sensitized solar cells.
Science.gov (United States)
Snaith, Henry J; Humphry-Baker, Robin; Chen, Peter; Cesar, Ilkay; Zakeeruddin, Shaik M; Grätzel, Michael
2008-10-22
The solar to electrical power conversion efficiency for dye-sensitized solar cells (DSCs) incorporating a solid-state organic hole-transporter can be over 5%. However, this is for devices significantly thinner than the optical depth of the active composites and by comparison to the liquid electrolyte based DSCs, which exhibit efficiencies in excess of 10%, more than doubling of this efficiency is clearly attainable if all the steps in the photovoltaic process can be optimized. Two issues are currently being addressed by the field. The first aims at enhancing the electron diffusion length by either reducing the charge recombination or enhancing the charge transport rates. This should enable a larger fraction of photogenerated charges to be collected. The second, though less actively investigated, aims to improve the physical composite formation, which in this instance is the infiltration of mesoporous TiO(2) with the organic hole-transporter 2,2',7,7'-tetrakis(N,N-di-p-methoxypheny-amine)-9,9'-spirobifluorene (spiro-MeOTAD). Here, we perform a broad experimental study to elucidate the limiting factors to the solar cell performance. We first investigate the charge transport and recombination in the solid-state dye-sensitized solar cell under realistic working conditions via small perturbation photovoltage and photocurrent decay measurements. From these measurements we deduce that the electron diffusion length near short-circuit is as long as 20 µm. However, at applied biases approaching open-circuit potential under realistic solar conditions, the diffusion length becomes comparable with the film thickness, ∼2 µm, illustrating that real losses to open-circuit voltage, fill factor and hence efficiency are occurring due to ineffective charge collection. The long diffusion length near short-circuit, on the other hand, illustrates that another process, separate from ineffective charge collection, is rendering the solar cell less than ideal. We investigate the
1. Phase sensitive diffraction sensor for high sensitivity refractive index measurement
Science.gov (United States)
Kumawat, Nityanand; Varma, Manoj; Kumar, Sunil
2018-02-01
In this study a diffraction based sensor has been developed for bio molecular sensing applications and performing assays in real time. A diffraction grating fabricated on a glass substrate produced diffraction patterns both in transmission and reflection when illuminated by a laser diode. We used zeroth order I(0,0) as reference and first order I(0,1) as signal channel and conducted ratiometric measurements that reduced noise by more than 50 times. The ratiometric approach resulted in a very simple instrumentation with very high sensitivity. In the past, we have shown refractive index measurements both for bulk and surface adsorption using the diffractive self-referencing approach. In the current work we extend the same concept to higher diffraction orders. We have considered order I(0,1) and I(1,1) and performed ratiometric measurements I(0,1)/I(1,1) to eliminate the common mode fluctuations. Since orders I(0,1) and I(1,1) behaved opposite to each other, the resulting ratio signal amplitude increased more than twice compared to our previous results. As a proof of concept we used different salt concentrations in DI water. Increased signal amplitude and improved fluid injection system resulted in more than 4 times improvement in detection limit, giving limit of detection 1.3×10-7 refractive index unit (RIU) compared to our previous results. The improved refractive index sensitivity will help significantly for high sensitivity label free bio sensing application in a very cost-effective and simple experimental set-up.
2. Resonance charge exchange mechanism at high and moderate energies
International Nuclear Information System (INIS)
Bogdanov, A.V.; Gevorkyan, A.S.
1984-01-01
Charge exchange mechanisms at high and medium energies are investigated, ta king the resonance charge exchange of a proton by an hydrogen atom as an example . It is established that there are two classical charge exchange mechanisms rel ated to direct proton knockout from the bound state and one quantum-mechanical mechanism corresponding to the electron tunnelling from one bound state to anoth er. The classical cross-section diverges for two of these mechanisms, and the quasiclassical scattering amplitude must be calculated on the base of a complex classical trajectory. Physical grounds for the choice of such trajectories are discussed and calculations of the Van Vleck determinant for these mechanisms a re presented. Contributions from different mechanisms to the total charge excha nge cross-section are analyzed. A comparison with experimental data and results of other authors is made
3. Charged particle beam scanning using deformed high gradient insulator
Science.gov (United States)
Chen, Yu -Jiuan
2015-10-06
Devices and methods are provided to allow rapid deflection of a charged particle beam. The disclosed devices can, for example, be used as part of a hadron therapy system to allow scanning of a target area within a patient's body. The disclosed charged particle beam deflectors include a dielectric wall accelerator (DWA) with a hollow center and a dielectric wall that is substantially parallel to a z-axis that runs through the hollow center. The dielectric wall includes one or more deformed high gradient insulators (HGIs) that are configured to produce an electric field with an component in a direction perpendicular to the z-axis. A control component is also provided to establish the electric field component in the direction perpendicular to the z-axis and to control deflection of a charged particle beam in the direction perpendicular to the z-axis as the charged particle beam travels through the hollow center of the DWA.
4. Multistage charged particle accelerator, with high-vacuum insulation
International Nuclear Information System (INIS)
Holl, P.
1976-01-01
A multistage charged-particle accelerator for operating with accelerating voltages higher than 150 kV is described. The device consists essentially of a high-voltage insulator, a source for producing charged particles, a Wehnelt cylinder, an anode, and a post-accelerating tube containing stack-wise positioned post-accelerating electrodes. A high vacuum is used for insulating the parts carrying the high voltages, and at least one cylindrical screen surrounding these parts is interposed between them and the vacuum vessel, which can itself also function as a cylindrical screen
5. Charge and energy transfer interplay in hybrid sensitized solar cells mediated by graphene quantum dots
International Nuclear Information System (INIS)
Mihalache, Iuliana; Radoi, Antonio; Mihaila, Mihai; Munteanu, Cornel; Marin, Alexandru; Danila, Mihai; Kusko, Mihaela; Kusko, Cristian
2015-01-01
Highlights: • We report a one pot synthesis metod of GQD with controlled size and optoelectronic properties. • An improvement of common N3-DSSC characteristics is achieved when GQDs are used as co-sensitiser. • The role of GQD as cosensitisers in hybrid DSSC was investigated and the interplay between charge and energy transfer phenomena mediated by GQDs was demonstrated. • The GQDs presence determines an inhibition of the recombination processes at the TiO 2 /electrolyte interface. - Abstract: We explored the role of graphene quantum dots (GQDs) as co-sensitizers in hybrid dye sensitized solar cell (DSSC) architectures, focusing on various concurring mechanisms, such as: charge transfer, energy transfer and recombination rate, towards light harvesting improvement. GQDs were prepared by the hydrothermal method that allows the tuning of electronic levels and optical properties by employing appropriate precursors and synthesis conditions. The aim was to realize a type II alignment for TiO 2 /GQD/dye hybrid configuration, using standard N3 Ru-dye in order to improve charge transfer. When GQDs were used as co-sensitizers together with N3 Ru-dye, an improvement in power conversion efficiency was achieved, as shown by electrical measurements. The experimental analysis indicates that this improvement arises from the interplay of various mechanisms mediated by GQDs: (i) enhancement of charge separation and collection due to the cascaded alignment of the energy levels; (ii) energy transfer from GQDs to N3 Ru-dye due to the overlap between GQD photoluminescence and N3 Ru-dye absorption spectra; and (iii) reduction of the electron recombination to the redox couple due to the inhibition of the back electron transfer to the electrolyte by the GQDs
6. Interfacial charge separation and photovoltaic efficiency in Fe(ii)-carbene sensitized solar cells.
Science.gov (United States)
Pastore, Mariachiara; Duchanois, Thibaut; Liu, Li; Monari, Antonio; Assfeld, Xavier; Haacke, Stefan; Gros, Philippe C
2016-10-12
The first combined theoretical and photovoltaic characterization of both homoleptic and heteroleptic Fe(ii)-carbene sensitized photoanodes in working dye sensitized solar cells (DSSCs) has been performed. Three new heteroleptic Fe(ii)-NHC dye sensitizers have been synthesized, characterized and tested. Despite an improved interfacial charge separation in comparison to the homoleptic compounds, the heteroleptic complexes did not show boosted photovoltaic performances. The ab initio quantitative analysis of the interfacial electron and hole transfers and the measured photovoltaic data clearly evidenced fast recombination reactions for heteroleptics, even associated with un unfavorable directional electron flow, and hence slower injection rates, in the case of homoleptics. Notably, quantum mechanics calculations revealed that deprotonation of the not anchored carboxylic function in the homoleptic complex can effectively accelerate the electron injection rate and completely suppress the electron recombination to the oxidized dye. This result suggests that introduction of strong electron-donating substituents on the not-anchored carbene ligand in heteroleptic complexes, in such a way of mimicking the electronic effects of the carboxylate functionality, should yield markedly improved interfacial charge generation properties. The present results, providing for the first time a detailed understanding of the interfacial electron transfers and photovoltaic characterization in Fe(ii)-carbene sensitized solar cells, open the way to a rational molecular engineering of efficient iron-based dyes for photoelectrochemical applications.
7. Highly charged atomic physics at HIRFL-CSR
International Nuclear Information System (INIS)
Ma Xinwen; Wang Youde; Hou Mingdong; Jin Gengmin
1996-01-01
HIRFL-CSR is a proposed electron cooling storage ring optimized to accelerate and store beams of highly charged heavy ions. Several possibilities for advanced atomic physics studies are discussed, such as studies of electron-ion, ion-atoms, photon-ion-electron interactions and high resolution spectroscopy
8. Integrating a redox-coupled dye-sensitized photoelectrode into a lithium-oxygen battery for photoassisted charging.
Science.gov (United States)
Yu, Mingzhe; Ren, Xiaodi; Ma, Lu; Wu, Yiying
2014-10-03
With a high theoretical specific energy, the non-aqueous rechargeable lithium-oxygen battery is a promising next-generation energy storage technique. However, the large charging overpotential remains a challenge due to the difficulty in electrochemically oxidizing the insulating lithium peroxide. Recently, a redox shuttle has been introduced into the electrolyte to chemically oxidize lithium peroxide. Here, we report the use of a triiodide/iodide redox shuttle to couple a built-in dye-sensitized titanium dioxide photoelectrode with the oxygen electrode for the photoassisted charging of a lithium-oxygen battery. On charging under illumination, triiodide ions are generated on the photoelectrode, and subsequently oxidize lithium peroxide. Due to the contribution of the photovoltage, the charging overpotential is greatly reduced. The use of a redox shuttle to couple a photoelectrode and an oxygen electrode offers a unique strategy to address the overpotential issue of non-aqueous lithium-oxygen batteries and also a distinct approach for integrating solar cells and batteries.
9. Highly charged ions: a miniature laboratory for new fundamental science
International Nuclear Information System (INIS)
Gillaspy, J.D.
2002-01-01
Full text: Highly charged ions are 10-100 times smaller than ordinary atoms, yet they present within themselves a remarkably rich arena for testing fundamental aspects of physics. These tests are based on a precise analysis of the energy distribution of the photons that are emitted as electrons hop between energy levels within the highly charged ions. With sufficiently precise analysis, it may be possible to obtain new information about the structure of the vacuum, the effect of special relativity on many-body correlation, physics beyond the Standard Model, and the fundamental nature of quantum measurements. This talk will review the current state-of-the-art in the spectroscopy of highly charged ions, and give a look towards the future
10. Charged-particle mutagenesis 2. Mutagenic effects of high energy charged particles in normal human fibroblasts
Science.gov (United States)
Chen, D. J.; Tsuboi, K.; Nguyen, T.; Yang, T. C.
1994-01-01
The biological effects of high Linear Energy Transfer (LET) charged particles are a subject of great concern with regard to the prediction of radiation risk in space. In this report, mutagenic effects of high LET charged particles are quantitatively measured using primary cultures of human skin fibroblasts, and the spectrum of induced mutations are analyzed. The LET of the charged particles ranged from 25 KeV/micrometer to 975 KeV/micrometer with particle energy (on the cells) between 94-603 MeV/u. The X-chromosome linked hypoxanthine guanine phosphoribosyl transferase (hprt) locus was used as the target gene. Exposure to these high LET charged particles resulted in exponential survival curves; whereas, mutation induction was fitted by a linear model. The Relative Biological Effect (RBE) for cell-killing ranged from 3.73 to 1.25, while that for mutant induction ranged from 5.74 to 0.48. Maximum RBE values were obtained at the LET of 150 keV/micrometer. The inactivation cross-section (alpha i) and the action cross-section for mutant induction (alpha m) ranged from 2.2 to 92.0 sq micrometer and 0.09 to 5.56 x 10(exp -3) sq micrometer respectively. The maximum values were obtained by Fe-56 with an LET of 200 keV/micrometer. The mutagenicity (alpha m/alpha i) ranged from 2.05 to 7.99 x 10(exp -5) with the maximum value at 150 keV/micrometer. Furthermore, molecular analysis of mutants induced by charged particles indicates that higher LET beams are more likely to cause larger deletions in the hprt locus.
11. Charged-particle mutagenesis II. Mutagenic effects of high energy charged particles in normal human fibroblasts
Science.gov (United States)
Chen, D. J.; Tsuboi, K.; Nguyen, T.; Yang, T. C.
1994-01-01
The biological effects of high LET charged particles are a subject of great concern with regard to the prediction of radiation risk in space. In this report, mutagenic effects of high LET charged particles are quantitatively measured using primary cultures of human skin fibroblasts, and the spectrum of induced mutations are analyzed. The LET of the charged particles ranged from 25 KeV/micrometer to 975 KeV/micrometer with particle energy (on the cells) between 94-603 MeV/u. The X-chromosome linked hypoxanthine guanine phosphoribosyl transferase (hprt) locus was used as the target gene. Exposure to these high LET charged particles resulted in exponential survival curves; whereas, mutation induction was fitted by a linear model. The Relative Biological Effect (RBE) for cell-killing ranged from 3.73 to 1.25, while that for mutant induction ranged from 5.74 to 0.48. Maximum RBE values were obtained at the LET of 150 keV/micrometer. The inactivation cross-section (alpha i) and the action cross-section for mutant induction (alpha m) ranged from 2.2 to 92.0 micrometer2 and 0.09 to 5.56 x 10(-3) micrometer2, respectively. The maximum values were obtained by 56Fe with an LET of 200 keV/micrometer. The mutagenicity (alpha m/alpha i) ranged from 2.05 to 7.99 x 10(-5) with the maximum value at 150 keV/micrometer. Furthermore, molecular analysis of mutants induced by charged particles indicates that higher LET beams are more likely to cause larger deletions in the hprt locus.
12. Photoproduction of charged particle with high transverse momentum
International Nuclear Information System (INIS)
Campos Costa Ramos, S.E. de.
1986-09-01
Inclusive cross sections of high transverse moment charged pions induced by a high energy photon beam have been measured. These results do not account, neither in slope nor in normalisation, for the VDM component of the photon, evaluated with pion induced data taken in the same experimental conditions after VDM subtraction, excellent agreement is found with QCD calculations up to second order in α s , in an extended cinematic region, different choices of the gluon fragmentation function do not alter this conclusion. Our measures of the inclusive final state charge asymmetries also confirm QCD expectations. 42 refs [fr
13. Development of a Sweetness Sensor for Aspartame, a Positively Charged High-Potency Sweetener
Directory of Open Access Journals (Sweden)
Masato Yasuura
2014-04-01
Full Text Available Taste evaluation technology has been developed by several methods, such as sensory tests, electronic tongues and a taste sensor based on lipid/polymer membranes. In particular, the taste sensor can individually quantify five basic tastes without multivariate analysis. However, it has proven difficult to develop a sweetness sensor, because sweeteners are classified into three types according to the electric charges in an aqueous solution; that is, no charge, negative charge and positive charge. Using membrane potential measurements, the taste-sensing system needs three types of sensor membrane for each electric charge type of sweetener. Since the commercially available sweetness sensor was only intended for uncharged sweeteners, a sweetness sensor for positively charged high-potency sweeteners such as aspartame was developed in this study. Using a lipid and plasticizers, we fabricated various lipid/polymer membranes for the sweetness sensor to identify the suitable components of the sensor membranes. As a result, one of the developed sensors showed responses of more than 20 mV to 10 mM aspartame and less than 5 mV to any other taste. The responses of the sensor depended on the concentration of aspartame. These results suggested that the developed sweetness sensor had high sensitivity to and high selectivity for aspartame.
14. Development of a sweetness sensor for aspartame, a positively charged high-potency sweetener.
Science.gov (United States)
Yasuura, Masato; Tahara, Yusuke; Ikezaki, Hidekazu; Toko, Kiyoshi
2014-04-23
Taste evaluation technology has been developed by several methods, such as sensory tests, electronic tongues and a taste sensor based on lipid/polymer membranes. In particular, the taste sensor can individually quantify five basic tastes without multivariate analysis. However, it has proven difficult to develop a sweetness sensor, because sweeteners are classified into three types according to the electric charges in an aqueous solution; that is, no charge, negative charge and positive charge. Using membrane potential measurements, the taste-sensing system needs three types of sensor membrane for each electric charge type of sweetener. Since the commercially available sweetness sensor was only intended for uncharged sweeteners, a sweetness sensor for positively charged high-potency sweeteners such as aspartame was developed in this study. Using a lipid and plasticizers, we fabricated various lipid/polymer membranes for the sweetness sensor to identify the suitable components of the sensor membranes. As a result, one of the developed sensors showed responses of more than 20 mV to 10 mM aspartame and less than 5 mV to any other taste. The responses of the sensor depended on the concentration of aspartame. These results suggested that the developed sweetness sensor had high sensitivity to and high selectivity for aspartame.
15. HITRAP: A Facility for Experiments with Trapped Highly Charged Ions
International Nuclear Information System (INIS)
Quint, W.; Dilling, J.; Djekic, S.; Haeffner, H.; Hermanspahn, N.; Kluge, H.-J.; Marx, G.; Moore, R.; Rodriguez, D.; Schoenfelder, J.; Sikler, G.; Valenzuela, T.; Verdu, J.; Weber, C.; Werth, G.
2001-01-01
HITRAP is a planned ion trap facility for capturing and cooling of highly charged ions produced at GSI in the heavy-ion complex of the UNILAC-SIS accelerators and the ESR storage ring. In this facility heavy highly charged ions up to uranium will be available as bare nuclei, hydrogen-like ions or few-electron systems at low temperatures. The trap for receiving and studying these ions is designed for operation at extremely high vacuum by cooling to cryogenic temperatures. The stored highly charged ions can be investigated in the trap itself or can be extracted from the trap at energies up to about 10 keV/q. The proposed physics experiments are collision studies with highly charged ions at well-defined low energies (eV/u), high-accuracy measurements to determine the g-factor of the electron bound in a hydrogen-like heavy ion and the atomic binding energies of few-electron systems, laser spectroscopy of HFS transitions and X-ray spectroscopy
16. Pulse shape discrimination with silicon detectors using charge and current-sensitive preamplifiers
Energy Technology Data Exchange (ETDEWEB)
Hamrita, H.; Rauly, E.; Blumenfeld, Y.; Borderie, B.; Chabot, M.; Edelbruck, P.; Lavergne, L.; Le Bris, J.; Le Neindre, N.; Richard, A.; Rivet, M.F.; Scarpaci, J.A.; Barbey, S.; Becheva, E.; Bzyl, F.R.; D' Esesquelles, P.; Galichet, E.; Lalu, G.; Martinet, G.; Pierre, S. [Institut de Physique Nucleaire, IN2P3-CNRS, 91 - Orsay (France); Legou, Th.; Tillier, J.; Bocage, F.; Bougault, R.; Carniol, B.; Cussol, D.; Etasse, D.; Grevy, S.; Lopez, O.; Tamain, B.; Vient, E. [Caen Univ., LPC, IN2P3-CNRS, ENSI, 14 - Caen (France); Galichet, E. [Conservatoire National des Arts et Metier, 75 - Paris (France); Guinet, D.; Lautesse, Ph. [Villeurbanne Univ., Institut de Physique Nucleaire, IN2P3-CNRS, 69 (France); Lanzalone, G. [Catania Univ., INFN, Laboratori Nazionali del Sud and Dipartimento di Fisica e Astronomia, (Italy); Politi, G. [Catania Univ., INFN, Sezione di Catania and Dipartimento di Fisica e Astronomia (Italy); Rosato, E. [Napoli, Univ., Dipt. di Scienze Fisiche e Sezione INFN (Italy)
2003-07-01
For the first time shapes of current pulses from light charged particles and carbon ions are presented. Capabilities for pulse shape discrimination techniques are demonstrated. In this work, charge and current-sensitive preamplifier prototypes for nuclear structure and dynamics experiments have been developed and tested with the aim of improving PSD (pulse shape discrimination) method by studying in detail current signal shapes from particles and ions over a large energy range. Note that current signal shapes have been recently used in atomic cluster studies to identify partitions of carbon cluster fragmentation. The paper is organized as follows. Section 2 is devoted to characterization of preamplifiers. In section 3, results of on beam tests will be presented, discussed and compared to a simple simulation.
17. A fully integrated, monolithic, cryogenic charge sensitive preamplifier using N-channel JFETs and polysilicon resistors
International Nuclear Information System (INIS)
Jung, T.S.; Guckel, H.; Seefeldt, J.; Ott, G.; Ahn, Y.C.
1994-01-01
In this paper, an integrated charge preamplifier to be used with small (10--30 mm 2 ) Si(Li) and Ge(Li) X-ray detectors is described. The preamplifier is designed to operate at cryogenic temperatures (∼100 K to 160 K) for the best performance. An N-channel JFET process technology for integrated charge sensitive preamplifiers has been developed. The process integrates multiple pinch-off voltage JFETs fabricated in an n-type epitaxial layer on a low resistivity p-type substrate. The process also incorporates polysilicon resistors integrated on the same die as the JFETs. The optimized polysilicon resistors exhibit 1/f noise nearly as good as metal film resistors at the same current. Results for integrated amplifier are discussed
18. High density thermite mixture for shaped charge ordnance disposal
Directory of Open Access Journals (Sweden)
Tamer Elshenawy
2017-10-01
Full Text Available The effect of thermite mixture based on aluminum and ferric oxides for ammunition neutralization has been studied and tested. Thermochemical calculations have been carried out for different percentage of Al using Chemical Equilibrium Code to expect the highest performance thermite mixture used for shaped charge ordnance disposal. Densities and enthalpy of different formulations have been calculated and demonstrated. The optimized thermite formulation has been prepared experimentally using cold iso-static pressing technique, which exhibited relatively high density and high burning rate thermite mixture. The produced green product compacted powder mixture was tested against small caliber shaped charge bomblet for neutralization. Theoretical and experimental results showed that the prepared thermite mixture containing 33% of aluminum as a fuel with ferric oxide can be successfully used for shaped charge ordnance disposal.
19. Heterogeneous catalysis in highly sensitive microreactors
DEFF Research Database (Denmark)
Olsen, Jakob Lind
This thesis present a highly sensitive silicon microreactor and examples of its use in studying catalysis. The experimental setup built for gas handling and temperature control for the microreactor is described. The implementation of LabVIEW interfacing for all the experimental parts makes...
20. Aluminum nanocantilevers for high sensitivity mass sensors
DEFF Research Database (Denmark)
Davis, Zachary James; Boisen, Anja
2005-01-01
We have fabricated Al nanocantilevers using a simple, one mask contact UV lithography technique with lateral and vertical dimensions under 500 and 100 nm, respectively. These devices are demonstrated as highly sensitive mass sensors by measuring their dynamic properties. Furthermore, it is shown ...
1. High-sensitivity visualization of localized electric fields using low-energy electron beam deflection
Science.gov (United States)
Jeong, Samuel; Ito, Yoshikazu; Edwards, Gary; Fujita, Jun-ichi
2018-06-01
The visualization of localized electronic charges on nanocatalysts is expected to yield fundamental information about catalytic reaction mechanisms. We have developed a high-sensitivity detection technique for the visualization of localized charges on a catalyst and their corresponding electric field distribution, using a low-energy beam of 1 to 5 keV electrons and a high-sensitivity scanning transmission electron microscope (STEM) detector. The highest sensitivity for visualizing a localized electric field was ∼0.08 V/µm at a distance of ∼17 µm from a localized charge at 1 keV of the primary electron energy, and a weak local electric field produced by 200 electrons accumulated on the carbon nanotube (CNT) apex can be visualized. We also observed that Au nanoparticles distributed on a CNT forest tended to accumulate a certain amount of charges, about 150 electrons, at a ‑2 V bias.
2. Production of highly charged ion beams from ECR ion sources
International Nuclear Information System (INIS)
Xie, Z.Q.
1997-09-01
Electron Cyclotron Resonance (ECR) ion source development has progressed with multiple-frequency plasma heating, higher mirror magnetic fields and better technique to provide extra cold electrons. Such techniques greatly enhance the production of highly charged ions from ECR ion sources. So far at cw mode operation, up to 300 eμA of O 7+ and 1.15 emA of O 6+ , more than 100 eμA of intermediate heavy ions for charge states up to Ar 13+ , Ca 13+ , Fe 13+ , Co 14+ and Kr 18+ , and tens of eμA of heavy ions with charge states to Kr 26+ , Xe 28+ , Au 35+ , Bi 34+ and U 34+ have been produced from ECR ion sources. At an intensity of at least 1 eμA, the maximum charge state available for the heavy ions are Xe 36+ , Au 46+ , Bi 47+ and U 48+ . An order of magnitude enhancement for fully stripped argon ions (I ≥ 60 enA) also has been achieved. This article will review the ECR ion source progress and discuss key requirement for ECR ion sources to produce the highly charged ion beams
3. Selective Acylation Enhances Membrane Charge Sensitivity of the Antimicrobial Peptide Mastoparan-X
DEFF Research Database (Denmark)
Etzerodt, Thomas Povl; Henriksen, Jonas Rosager; Rasmussen, Palle
2011-01-01
and positioning of the peptide in the membrane caused by either PA or OA acylation play a critical role in the fine-tuning of the effective charge of the peptide and thereby the fine-tuning of the peptide's selectivity between neutral and negatively charged lipid membranes. This finding is unique compared...... to previous reports where peptide acylation enhanced membrane affinity but also resulted in impaired selectivity. Our result may provide a method of enhancing selectivity of antimicrobial peptides toward bacterial membranes due to their high negative charge—a finding that should be investigated for other...
4. Single photon detector with high polarization sensitivity.
Science.gov (United States)
Guo, Qi; Li, Hao; You, LiXing; Zhang, WeiJun; Zhang, Lu; Wang, Zhen; Xie, XiaoMing; Qi, Ming
2015-04-15
Polarization is one of the key parameters of light. Most optical detectors are intensity detectors that are insensitive to the polarization of light. A superconducting nanowire single photon detector (SNSPD) is naturally sensitive to polarization due to its nanowire structure. Previous studies focused on producing a polarization-insensitive SNSPD. In this study, by adjusting the width and pitch of the nanowire, we systematically investigate the preparation of an SNSPD with high polarization sensitivity. Subsequently, an SNSPD with a system detection efficiency of 12% and a polarization extinction ratio of 22 was successfully prepared.
5. Electron capture by highly charged ions from surfaces and gases
Energy Technology Data Exchange (ETDEWEB)
Allen, F.
2008-01-11
In this study highly charged ions produced in Electron Beam Ion Traps are used to investigate electron capture from surfaces and gases. The experiments with gas targets focus on spectroscopic measurements of the K-shell x-rays emitted at the end of radiative cascades following electron capture into Rydberg states of Ar{sup 17+} and Ar{sup 18+} ions as a function of collision energy. The ions are extracted from an Electron Beam Ion Trap at an energy of 2 keVu{sup -1}, charge-selected and then decelerated down to 5 eVu{sup -1} for interaction with an argon gas target. For decreasing collision energies a shift to electron capture into low orbital angular momentum capture states is observed. Comparative measurements of the K-shell x-ray emission following electron capture by Ar{sup 17+} and Ar{sup 18+} ions from background gas in the trap are made and a discrepancy in the results compared with those from the extraction experiments is found. Possible explanations are discussed. For the investigation of electron capture from surfaces, highly charged ions are extracted from an Electron Beam Ion Trap at energies of 2 to 3 keVu{sup -1}, charge-selected and directed onto targets comprising arrays of nanoscale apertures in silicon nitride membranes. The highly charged ions implemented are Ar{sup 16+} and Xe{sup 44+} and the aperture targets are formed by focused ion beam drilling in combination with ion beam assisted thin film deposition, achieving hole diameters of 50 to 300 nm and aspect ratios of 1:5 to 3:2. After transport through the nanoscale apertures the ions pass through an electrostatic charge state analyzer and are detected. The percentage of electron capture from the aperture walls is found to be much lower than model predictions and the results are discussed in terms of a capillary guiding mechanism. (orig.)
6. Electron capture by highly charged ions from surfaces and gases
International Nuclear Information System (INIS)
Allen, F.
2008-01-01
In this study highly charged ions produced in Electron Beam Ion Traps are used to investigate electron capture from surfaces and gases. The experiments with gas targets focus on spectroscopic measurements of the K-shell x-rays emitted at the end of radiative cascades following electron capture into Rydberg states of Ar 17+ and Ar 18+ ions as a function of collision energy. The ions are extracted from an Electron Beam Ion Trap at an energy of 2 keVu -1 , charge-selected and then decelerated down to 5 eVu -1 for interaction with an argon gas target. For decreasing collision energies a shift to electron capture into low orbital angular momentum capture states is observed. Comparative measurements of the K-shell x-ray emission following electron capture by Ar 17+ and Ar 18+ ions from background gas in the trap are made and a discrepancy in the results compared with those from the extraction experiments is found. Possible explanations are discussed. For the investigation of electron capture from surfaces, highly charged ions are extracted from an Electron Beam Ion Trap at energies of 2 to 3 keVu -1 , charge-selected and directed onto targets comprising arrays of nanoscale apertures in silicon nitride membranes. The highly charged ions implemented are Ar 16+ and Xe 44+ and the aperture targets are formed by focused ion beam drilling in combination with ion beam assisted thin film deposition, achieving hole diameters of 50 to 300 nm and aspect ratios of 1:5 to 3:2. After transport through the nanoscale apertures the ions pass through an electrostatic charge state analyzer and are detected. The percentage of electron capture from the aperture walls is found to be much lower than model predictions and the results are discussed in terms of a capillary guiding mechanism. (orig.)
7. Reduction of digital errors of digital charge division type position-sensitive detectors
International Nuclear Information System (INIS)
Uritani, A.; Yoshimura, K.; Takenaka, Y.; Mori, C.
1994-01-01
It is well known that ''digital errors'', i.e. differential non-linearity, appear in a position profile of radiation interactions when the profile is obtained with a digital charge-division-type position-sensitive detector. Two methods are presented to reduce the digital errors. They are the methods using logarithmic amplifiers and a weighting function. The validities of these two methods have been evaluated mainly by computer simulation. These methods can considerably reduce the digital errors. The best results are obtained when both methods are applied. ((orig.))
8. Mean charged hadron multiplicities in high-energy collisions
Energy Technology Data Exchange (ETDEWEB)
Albini, E [Istituto di Matematica dell' Universita Cattolica di Brescia (Italy); Capiluppi, P; Giacomelli, G; Rossi, A M [Bologna Univ. (Italy). Istituto di Fisica
1976-03-01
A collection of mean charged hadron multiplicities per inelastic collision in various high-energy processes is presented. An extensive list of fits of as a function of energy is presented and discussed. As the energy increases the multiplicities for different collisions tend to a unique curve, independent of the type of colliding particles.
9. Thermal spike analysis of highly charged ion tracks
International Nuclear Information System (INIS)
Karlušić, M.; Jakšić, M.
2012-01-01
The irradiation of material using swift heavy ion or highly charged ion causes excitation of the electron subsystem at nanometer scale along the ion trajectory. According to the thermal spike model, energy deposited into the electron subsystem leads to temperature increase due to electron–phonon coupling. If ion-induced excitation is sufficiently intensive, then melting of the material can occur, and permanent damage (i.e., ion track) can be formed upon rapid cooling. We present an extension of the analytical thermal spike model of Szenes for the analysis of surface ion track produced after the impact of highly charged ion. By applying the model to existing experimental data, more than 60% of the potential energy of the highly charged ion was shown to be retained in the material during the impact and transformed into the energy of the thermal spike. This value is much higher than 20–40% of the transferred energy into the thermal spike by swift heavy ion. Thresholds for formation of highly charged ion track in different materials show uniform behavior depending only on few material parameters.
10. Production of highly charged ion beams with SECRAL
International Nuclear Information System (INIS)
Sun, L. T.; Zhao, H. W.; Zhang, X. Z.; Feng, Y. C.; Li, J. Y.; Guo, X. H.; Ma, H. Y.; Zhao, H. Y.; Ma, B. H.; Wang, H.; Li, X. X.; Jin, T.; Xie, D. Z.; Lu, W.; Cao, Y.; Shang, Y.
2010-01-01
Superconducting electron cyclotron resonance ion source with advanced design in Lanzhou (SECRAL) is an all-superconducting-magnet electron cyclotron resonance ion source (ECRIS) for the production of intense highly charged ion beams to meet the requirements of the Heavy Ion Research Facility in Lanzhou (HIRFL). To further enhance the performance of SECRAL, an aluminum chamber has been installed inside a 1.5 mm thick Ta liner used for the reduction of x-ray irradiation at the high voltage insulator. With double-frequency (18+14.5 GHz) heating and at maximum total microwave power of 2.0 kW, SECRAL has successfully produced quite a few very highly charged Xe ion beams, such as 10 e μA of Xe 37+ , 1 e μA of Xe 43+ , and 0.16 e μA of Ne-like Xe 44+ . To further explore the capability of the SECRAL in the production of highly charged heavy metal ion beams, a first test run on bismuth has been carried out recently. The main goal is to produce an intense Bi 31+ beam for HIRFL accelerator and to have a feel how well the SECRAL can do in the production of very highly charged Bi beams. During the test, though at microwave power less than 3 kW, more than 150 e μA of Bi 31+ , 22 e μA of Bi 41+ , and 1.5 e μA of Bi 50+ have been produced. All of these results have again demonstrated the great capability of the SECRAL source. This article will present the detailed results and brief discussions to the production of highly charged ion beams with SECRAL.
11. Highly sensitive microcalorimeters for radiation research
International Nuclear Information System (INIS)
Avaev, V.N.; Demchuk, B.N.; Ioffe, L.A.; Efimov, E.P.
1984-01-01
Calorimetry is used in research at various types of nuclear-physics installations to obtain information on the quantitative and qualitative composition of ionizing radiation in a reactor core and in the surrounding layers of the biological shield. In this paper, the authors examine the characteristics of highly sensitive microcalorimeters with modular semiconductor heat pickups designed for operation in reactor channels. The microcalorimeters have a thin-walled aluminum housing on whose inner surface modular heat pickups are placed radially as shown here. The results of measurements of the temperature dependence of the sensitivity of the microcalorimeters are shown. The results of measuring the sensitivity of a PMK-2 microcalorimeter assembly as a function of integrated neutron flux for three energy intervals and the adsorbed gamma energy are shown. In order to study specimens with different shapes and sizes, microcalorimeters with chambers in the form of cylinders and a parallelepiped were built and tested
12. High blood pressure and visual sensitivity
Science.gov (United States)
Eisner, Alvin; Samples, John R.
2003-09-01
The study had two main purposes: (1) to determine whether the foveal visual sensitivities of people treated for high blood pressure (vascular hypertension) differ from the sensitivities of people who have not been diagnosed with high blood pressure and (2) to understand how visual adaptation is related to standard measures of systemic cardiovascular function. Two groups of middle-aged subjects-hypertensive and normotensive-were examined with a series of test/background stimulus combinations. All subjects met rigorous inclusion criteria for excellent ocular health. Although the visual sensitivities of the two subject groups overlapped extensively, the age-related rate of sensitivity loss was, for some measures, greater for the hypertensive subjects, possibly because of adaptation differences between the two groups. Overall, the degree of steady-state sensitivity loss resulting from an increase of background illuminance (for 580-nm backgrounds) was slightly less for the hypertensive subjects. Among normotensive subjects, the ability of a bright (3.8-log-td), long-wavelength (640-nm) adapting background to selectively suppress the flicker response of long-wavelength-sensitive (LWS) cones was related inversely to the ratio of mean arterial blood pressure to heart rate. The degree of selective suppression was also related to heart rate alone, and there was evidence that short-term changes of cardiovascular response were important. The results suggest that (1) vascular hypertension, or possibly its treatment, subtly affects visual function even in the absence of eye disease and (2) changes in blood flow affect retinal light-adaptation processes involved in the selective suppression of the flicker response from LWS cones caused by bright, long-wavelength backgrounds.
13. Photoinduced High-Frequency Charge Oscillations in Dimerized Systems
Science.gov (United States)
Yonemitsu, Kenji
2018-04-01
Photoinduced charge dynamics in dimerized systems is studied on the basis of the exact diagonalization method and the time-dependent Schrödinger equation for a one-dimensional spinless-fermion model at half filling and a two-dimensional model for κ-(bis[ethylenedithio]tetrathiafulvalene)2X [κ-(BEDT-TTF)2X] at three-quarter filling. After the application of a one-cycle pulse of a specifically polarized electric field, the charge densities at half of the sites of the system oscillate in the same phase and those at the other half oscillate in the opposite phase. For weak fields, the Fourier transform of the time profile of the charge density at any site after photoexcitation has peaks for finite-sized systems that correspond to those of the steady-state optical conductivity spectrum. For strong fields, these peaks are suppressed and a new peak appears on the high-energy side, that is, the charge densities mainly oscillate with a single frequency, although the oscillation is eventually damped. In the two-dimensional case without intersite repulsion and in the one-dimensional case, this frequency corresponds to charge-transfer processes by which all the bonds connecting the two classes of sites are exploited. Thus, this oscillation behaves as an electronic breathing mode. The relevance of the new peak to a recently found reflectivity peak in κ-(BEDT-TTF)2X after photoexcitation is discussed.
14. ERC sources for the production of highly charged ions (invited)
International Nuclear Information System (INIS)
Lyneis, C.M.; Antaya, T.A.
1990-01-01
Electron cyclotron resonance ion sources (ECRIS) using rf between 5 and 16 GHz have been developed into stable, reliable sources of highly charged ions produced from a wide range of elements. These devices are currently used as ion sources for cyclotrons, synchrotrons, and heavy-ion linacs for nuclear and relativistic heavy-ion physics. They also serve the atomic physics community as a source of low energy multiply charged ions. In order to improve their performance both with respect to maximum charge state and beam intensity, ECRIS builders are now designing and constructing sources which will operate at frequencies up to 30 GHz. In this article we review the present status of operating ECRIS, review recent experimental measurements on plasma parameters, and look at the technology and potential of sources operating at frequencies up to 30 GHz
15. Vacuum improvements for ultra high charge state ion acceleration
International Nuclear Information System (INIS)
Xie, Z.Q.; Lyneis, C.M.; Clark, D.J.; Guy, A.; Lundgren, S.A
1998-06-01
The installation of a second cryo panel has significantly improved the vacuum in the 88-Inch Cyclotron at Lawrence Berkeley National Laboratory. The neutral pressure in the extraction region decreased from 1.2 x 10 -6 down to about 7 x 10 -7 Torr. The vacuum improvement reduces beam loss from charge changing collisions and enhances the cyclotron beam transmission, especially for the high charge state heavy ions. Tests with improved vacuum show the cyclotron transmission increased more than 50% (from 5.7% to 9.0%) for a Xe 27+ at 603 MeV, more than doubled for a Bi 41+ beam (from 1.9% to 4.6%) at 904 MeV and tripled for a U 47+ beam (from 1.2% to 3.6%) at 1,115 MeV. At about 5 NeV/nucleon 92 enA (2.2 pnA) for Bi 41+ and 14 enA (0.3 pnA) for U 47+ were extracted ut of the 88-Inch Cyclotron Ion beams with charge states as high as U 64+ have been produced by the LBNL AECR-U ion source and accelerated through the cyclotron for the first time. The beam losses for a variety of ultra high charge state ions were measured as a function of cyclotron pressure and compared with the calculations from the existing models
16. Vacuum improvements for ultra high charge state ion acceleration
International Nuclear Information System (INIS)
Xie, Z.Q.; Lyneis, C.M.; Clark, D.J.; Guy, A.; Lundgren, S.A.
1999-01-01
The installation of a second cryo panel has significantly improved the vacuum in the 88-Inch Cyclotron at Lawrence Berkeley National Laboratory. The neutral pressure in the extraction region decreased from 1.2 x 10 -6 down to about 7 x 10 -7 Torr. The vacuum improvement reduces beam loss from charge changing collisions and enhances the cyclotron beam transmission, especially for the high charge state heavy ions. Tests with improved vacuum show the cyclotron transmission increased more than 50% (from 5.7% to 9.0%) for a Xe 27+ at 603 MeV, more than doubled for a Bi 41+ beam (from 1.9% % to 4.6%) at 904 MeV and tripled for a U 47+ beam (from 1.2% to 3.6%) at 1115 MeV. At about 5 MeV/nucleon 92 enA (2.2 pnA) for Bi 41+ and 14 enA (0.3 pnA) for U 47+ were extracted out of the 88-Inch Cyclotron Ion beams with charge states as high as U 64+ have been produced by the LBNL AECR-U ion source and accelerated through the cyclotron for the first time. The beam losses for a variety of ultra high charge state ions were measured as a function of cyclotron pressure and compared with the calculations from the existing models. (authors)
17. Laser focusing of high-energy charged-particle beams
International Nuclear Information System (INIS)
Channell, P.J.
1986-01-01
It is shown that laser focusing of high-energy charged-particle beams using the inverse Cherenkov effect is well suited for applications with large linear colliders. Very high gradient (>0.5 MG/cm) lenses result that can be added sequentially without AG cancellation. These lenses are swell understood, have small geometric aberrations, and offer the possibility of correlating phase and energy aberrations to produce an achromatic final focus
18. Low Cost, Low Power, High Sensitivity Magnetometer
Science.gov (United States)
2008-12-01
which are used to measure the small magnetic signals from brain. Other types of vector magnetometers are fluxgate , coil based, and magnetoresistance...concentrator with the magnetometer currently used in Army multimodal sensor systems, the Brown fluxgate . One sees the MEMS fluxgate magnetometer is...Guedes, A.; et al., 2008: Hybrid - LOW COST, LOW POWER, HIGH SENSITIVITY MAGNETOMETER A.S. Edelstein*, James E. Burnette, Greg A. Fischer, M.G
19. Electron impact ionization of highly charged lithiumlike ions
International Nuclear Information System (INIS)
Wong, K.L.
1992-10-01
Electron impact ionization cross sections can provide valuable information about the charge-state and power balance of highly charged ions in laboratory and astrophysical plasmas. In the present work, a novel technique based on x-ray measurements has been used to infer the ionization cross section of highly charged lithiumlike ions on the Livermore electron beam ion trap. In particular, a correspondence is established between an observed x ray and an ionization event. The measurements are made at one energy corresponding to approximately 2.3 times the threshold energy for ionization of lithiumlike ions. The technique is applied to the transition metals between Z=22 (titanium, Ti 19+ ) and Z=26 (iron, Fe 23+ ) and to Z=56 (barium, Ba 53+ ). The results for the transition metals, which have an estimated 17-33% uncertainty, are in good overall agreement with a relativistic distorted-wave calculation. However, less good agreement is found for barium, which has a larger uncertainty. Methods for properly accounting for the polarization in the x-ray intensities and for inferring the charge-state abundances from x-ray observations, which were developed for the ionization measurements, as well as an x-ray model that assists in the proper interpretation of the data are also presented
20. DEPTH-CHARGE static and time-dependent perturbation/sensitivity system for nuclear reactor core analysis. Revision I. [DEPTH-CHARGE code
Energy Technology Data Exchange (ETDEWEB)
White, J.R.
1985-04-01
This report provides the background theory, user input, and sample problems required for the efficient application of the DEPTH-CHARGE system - a code black for both static and time-dependent perturbation theory and data sensitivity analyses. The DEPTH-CHARGE system is of modular construction and has been implemented within the VENTURE-BURNER computational system at Oak Ridge National Laboratory. The DEPTH module (coupled with VENTURE) solves for the three adjoint functions of Depletion Perturbation Theory and calculates the desired time-dependent derivatives of the response with respect to the nuclide concentrations and nuclear data utilized in the reference model. The CHARGE code is a collection of utility routines for general data manipulation and input preparation and considerably extends the usefulness of the system through the automatic generation of adjoint sources, estimated perturbed responses, and relative data sensitivity coefficients. Combined, the DEPTH-CHARGE system provides, for the first time, a complete generalized first-order perturbation/sensitivity theory capability for both static and time-dependent analyses of realistic multidimensional reactor models. This current documentation incorporates minor revisions to the original DEPTH-CHARGE documentation (ORNL/CSD-78) to reflect some new capabilities within the individual codes.
1. Charge transport in highly efficient iridium cored electrophosphorescent dendrimers
Science.gov (United States)
Markham, Jonathan P. J.; Samuel, Ifor D. W.; Lo, Shih-Chun; Burn, Paul L.; Weiter, Martin; Bässler, Heinz
2004-01-01
Electrophosphorescent dendrimers are promising materials for highly efficient light-emitting diodes. They consist of a phosphorescent core onto which dendritic groups are attached. Here, we present an investigation into the optical and electronic properties of highly efficient phosphorescent dendrimers. The effect of dendrimer structure on charge transport and optical properties is studied using temperature-dependent charge-generation-layer time-of-flight measurements and current voltage (I-V) analysis. A model is used to explain trends seen in the I-V characteristics. We demonstrate that fine tuning the mobility by chemical structure is possible in these dendrimers and show that this can lead to highly efficient bilayer dendrimer light-emitting diodes with neat emissive layers. Power efficiencies of 20 lm/W were measured for devices containing a second-generation (G2) Ir(ppy)3 dendrimer with a 1,3,5-tris(2-N-phenylbenzimidazolyl)benzene electron transport layer.
2. Sensitivity of the CSR self-interaction to the local longitudinal charge concentration of an electron bunch
CERN Document Server
Li, R
2001-01-01
Recent measurements of the coherent synchrotron radiation (CSR) effects indicated that the observed emittance growth and energy modulation due to the orbit-curvature-induced bunch self-interaction are sometimes bigger than predictions based on Gaussian longitudinal charge distributions. In this paper, by performing a model study, we show both analytically and numerically that when the longitudinal bunch charge distribution involves concentration of charges in a small fraction of the bunch length, enhancement of the CSR self-interaction beyond the Gaussian prediction may occur. The level of this enhancement is sensitive to the level of the local charge concentration.
3. Amplified Sensitivity of Nitrogen-Vacancy Spins in Nanodiamonds Using All-Optical Charge Readout.
Science.gov (United States)
Hopper, David A; Grote, Richard R; Parks, Samuel M; Bassett, Lee C
2018-04-23
Nanodiamonds containing nitrogen-vacancy (NV) centers offer a versatile platform for sensing applications spanning from nanomagnetism to in vivo monitoring of cellular processes. In many cases, however, weak optical signals and poor contrast demand long acquisition times that prevent the measurement of environmental dynamics. Here, we demonstrate the ability to perform fast, high-contrast optical measurements of charge distributions in ensembles of NV centers in nanodiamonds and use the technique to improve the spin-readout signal-to-noise ratio through spin-to-charge conversion. A study of 38 nanodiamonds with sizes ranging between 20 and 70 nm, each hosting a small ensemble of NV centers, uncovers complex, multiple time scale dynamics due to radiative and nonradiative ionization and recombination processes. Nonetheless, the NV-containing nanodiamonds universally exhibit charge-dependent photoluminescence contrasts and the potential for enhanced spin readout using spin-to-charge conversion. We use the technique to speed up a T 1 relaxometry measurement by a factor of 5.
4. Two-dimensional CsPbBr3/PCBM heterojunctions for sensitive, fast and flexible photodetectors boosted by charge transfer
Science.gov (United States)
Shen, Yalong; Yu, Dejian; Wang, Xiong; Huo, Chengxue; Wu, Ye; Zhu, Zhengfeng; Zeng, Haibo
2018-02-01
Inorganic halide perovskites exhibited promising potentials for high-performance wide-band photodetectors (PDs) due to their high light absorption coefficients, long carrier diffusion length and wide light absorption ranges. Here, we report two-dimensional (2D) CsPbBr3/PCBM heterojunctions for sensitive, fast and flexible PDs, whose performances can be greatly boosted by the charge transfer through the energy-aligned interface. The 2D CsPbBr3 nanosheets with high crystallinity were fabricated via a simple solution-process at room temperature, and then assembled into flexible heterojunctions films with polymerphenyl-C61-butyric acid methyl ester (PCBM). Significantly, the efficient and fast charge transfer at the heterojunctions interface was evidenced by the obvious photoluminescence quenching and variation of recombination dynamics. Subsequently, such heterojunctions PD exhibited an enhanced responsivity of 10.85 A W-1 and an ultrahigh detectivity of 3.06 × 1013 Jones. In addition, the PD shows a broad linear dynamic range of 73 dB, a fast response speed with rise time of 44 μs and decay time of 390 μs, respectively. Moreover, the PD lying on polyethylene terephthalate substrates exhibited an outstanding mechanical flexibility and a robust electrical stability. These results could provide a new avenue for integration of 2D perovskites and organic functional materials and for high-performance flexible PDs.
5. Interaction of low-energy highly charged ions with matter
International Nuclear Information System (INIS)
Ginzel, Rainer
2010-01-01
The thesis presented herein deals with experimental studies of the interaction between highly charged ions and neutral matter at low collision energies. The energy range investigated is of great interest for the understanding of both charge exchange reactions between ions comprising the solar wind and various astrophysical gases, as well as the creation of near-surface nanostructures. Over the course of this thesis an experimental setup was constructed, capable of reducing the kinetic energy of incoming ions by two orders of magnitude and finally focussing the decelerated ion beam onto a solid or gaseous target. A coincidence method was employed for the simultaneous detection of photons emitted during the charge exchange process together with the corresponding projectile ions. In this manner, it was possible to separate reaction channels, whose superposition presumably propagated large uncertainties and systematic errors in previous measurements. This work has unveiled unexpectedly strong contributions of slow radiative decay channels and clear evidence of previously only postulated decay processes in charge exchange-induced X-ray spectra. (orig.)
6. Quantum electrodynamical effects in heavy highly-charged ions
International Nuclear Information System (INIS)
Yerokhin, V.A.; Artemyev, A.N.; Indelicato, P.; Shabaev, V.M.
2003-01-01
The present status of theoretical calculations of QED effects in highly charged ions is reviewed for several important cases: the Lamb shift in heavy H-like ions, the 2p 1/2 -2s transition energy in heavy Li-like ions, and the bound-electron g factor in H-like ions. Theoretical predictions are compared with experimental results. Special attention is paid to the discussion of uncertainties of theoretical predictions
7. Progress in quantum electrodynamics theory of highly charged ions
OpenAIRE
Volotka, A. V.; Glazov, D. A.; Plunien, G.; Shabaev, V. M.
2013-01-01
Recent progress in quantum electrodynamics (QED) calculations of highly charged ions is reviewed. The theoretical predictions for the binding energies, the hyperfine splittings, and the g factors are presented and compared with available experimental data. Special attention is paid to tests of bound-state QED at strong field regime. Future prospects for tests of QED at the strongest electric and magnetic fields as well as for determination of the fine structure constant and the nuclear magnet...
8. Electron capture by highly charged low-velocity ions
International Nuclear Information System (INIS)
Cocke, C.L.; Dubois, R.; Justiniano, E.; Gray, T.J.; Can, C.
1982-01-01
This paper describes the use of a fast heavy ion beam to produce, by bombardment of gaseous targets, highly-charged low-velocity recoil ions, and the use of these secondary ions in turn as projectiles in studies of electron capture and ionization in low-energy collision systems. The interest in collisions involving low-energy highly-charged projectiles comes both from the somewhat simplifying aspects of the physics which attend the long-range capture and from applications to fusion plasmas, astrophysics and more speculative technology such as the production of X-ray lasers. The ions of interest in such applications should have both electronic excitation and center-of-mass energies in the keV range and cannot be produced by simply stripping fast heavy ion beams. Several novel types of ion source have been developed to produce low-energy highly-charged ions, of which the secondary ion recoil source discussed in this paper is one. (Auth.)
9. Status of Charge Exchange Cross Section Measurements for Highly Charged Ions on Atomic Hydrogen
Science.gov (United States)
Draganic, I. N.; Havener, C. C.; Schultz, D. R.; Seely, D. G.; Schultz, P. C.
2011-05-01
Total cross sections of charge exchange (CX) for C5+, N6+, and O7+ ions on ground state atomic hydrogen are measured in an extended collision energy range of 1 - 20,000 eV/u. Absolute CX measurements are performed using an improved merged-beams technique with intense highly charged ion beams extracted from a 14.5 GHz ECR ion source mounted on a high voltage platform. In order to improve the problematic H+ signal collection for these exoergic CX collisions at low relative energies, a new double focusing electrostatic analyzer was installed. Experimental CX data are in good agreement with all previous H-oven relative measurements at higher collision energies. We compare our results with the most recent molecular orbital close-coupling (MOCC) and atomic orbital close-coupling (AOCC) theoretical calculations. Work supported by the NASA Solar & Heliospheric Physics Program NNH07ZDA001N, the Office of Fusion Energy Sciences and the Division of Chemical Sciences, Geosciences, and Biosciences, and the Office of Basic Energy Sciences of the U.S. DoE.
10. Review of high-sensitivity Radon studies
Science.gov (United States)
Wojcik, M.; Zuzel, G.; Simgen, H.
2017-10-01
A challenge in many present cutting-edge particle physics experiments is the stringent requirements in terms of radioactive background. In peculiar, the prevention of Radon, a radioactive noble gas, which occurs from ambient air and it is also released by emanation from the omnipresent progenitor Radium. In this paper we review various high-sensitivity Radon detection techniques and approaches, applied in the experiments looking for rare nuclear processes happening at low energies. They allow to identify, quantitatively measure and finally suppress the numerous sources of Radon in the detectors’ components and plants.
11. A double-gate double-feedback JFET charge-sensitive preamplifier
International Nuclear Information System (INIS)
Fazzi, A.
1996-01-01
A new charge-sensitive preamplifier (CSP) without a physical resistance in the feedback is presented. The input device has to be a double-gate JFET. In this new preamplifier configuration the feedback capacitor is continuously discharged by means of a second DC current feedback loop closed through the bottom gate of the input JFET. The top gate-channel junction works as usual in reverse bias, the bottom gate-channel is forward biased. A fraction of the current injected by the bottom gate reaches the top gate discharging the feedback capacitor. The n-channel double-gate JFET is considered from the viewpoint of the restoring action as a parasitic p-n-p ''transversal'' bipolar junction transistor. The new preamplifier is also suited for detectors operating at room temperature with leakage current which may vary with time. The DC behaviour and the dynamic behaviour of the circuit is analyzed and new measurements presented. (orig.)
12. Effective charge collection in dye-sensitized nanocrystalline TiO2
Science.gov (United States)
Yanagida, Masatoshi; Numata, Youhei; Yoshimatsu, Keiichi; Satoh, Shin; Han, Liyuan
2013-03-01
The effective charge collection in dye-sensitized solar cells (DSCs) is an important factor to improve the efficiency. Here, we report the comparison of three types of structures in DSCs. One type of structure is a sandwich-type DSC (SW-DSC), in which the TiO2 film is sandwiched between a TCO glass front electron-collection electrode and a sputtered Ti back collection electrode. The second is a normal DSC (N-DSC), which has no back electrode. The third is a back-contact-type DSC (BC-DSC), in which a sputtered Ti back electrode is deposited on a TiO2 film on the opposite side of the normal glass as an optical window. The photocurrent response of an SW-DSC is the fastest of the three structures due to using intensity modulated photocurrent spectroscopy, which can be explained by the electron diffusion model. The model shows that the SW-DSC is a favorable structure for effective charge collection in DSCs.
13. Effective charge collection in dye-sensitized nanocrystalline TiO2
International Nuclear Information System (INIS)
Yanagida, Masatoshi; Numata, Youhei; Yoshimatsu, Keiichi; Satoh, Shin; Han, Liyuan
2013-01-01
The effective charge collection in dye-sensitized solar cells (DSCs) is an important factor to improve the efficiency. Here, we report the comparison of three types of structures in DSCs. One type of structure is a sandwich-type DSC (SW-DSC), in which the TiO 2 film is sandwiched between a TCO glass front electron-collection electrode and a sputtered Ti back collection electrode. The second is a normal DSC (N-DSC), which has no back electrode. The third is a back-contact-type DSC (BC-DSC), in which a sputtered Ti back electrode is deposited on a TiO 2 film on the opposite side of the normal glass as an optical window. The photocurrent response of an SW-DSC is the fastest of the three structures due to using intensity modulated photocurrent spectroscopy, which can be explained by the electron diffusion model. The model shows that the SW-DSC is a favorable structure for effective charge collection in DSCs. (paper)
14. Multifunctional hybrid diode: Study of photoresponse, high responsivity, and charge injection mechanisms
Science.gov (United States)
Singh, Jitendra; Singh, R. G.; Gautam, Subodh K.; Singh, Fouran
2018-05-01
A multifunctional hybrid heterojunction diode is developed on porous silicon and its current density-voltage characteristics reveal a good rectification ratio along with other superior parameters such as ideality factor, barrier height and series resistance. The diode also functions as an efficient photodiode to manifest high photosensitivity with high responsivity under illumination with broadband solar light, UV light, and green light. The diode is also carefully scrutinized for its sensitivity and repeatability over many cycles under UV and green light and is found to have a quick response and extremely fast recovery times. The notable responsivity is attributed to the generation of high density of excitons in the depletion region by the absorption of incident photons and their separation by an internal electric field besides an additional photocurrent due to the charging of polymer chains. The mechanisms of generation, injection and transport of charge carriers are explained by developing a schematic energy band diagram. The transport phenomenon of carriers is further investigated from room temperature down to a very low temperature of 10 K. An Arrhenius plot is made to determine the Richardson constant. Various diode parameters as mentioned above are also determined and the dominance of the transport mechanism of charge carriers in different temperature regimes such as diffusion across the junction and/or quantum tunneling through the barriers are explained. The developed multifunction heterojunction hybrid diodes have implications for highly sensitive photodiodes in the UV and visible range of electromagnetic spectrum that can be very promising for efficient optoelectronic devices.
15. Highly charged ion impact induced nanodefects in diamond
Energy Technology Data Exchange (ETDEWEB)
Makgato, T.N., E-mail: thuto.makgato@wits.ac.za [School of Physics, University of the Witwatersrand, Johannesburg 2050 (South Africa); Microscopy and Microanalysis Unit, University of the Witwatersrand, Johannesburg 2050 (South Africa); Sideras-Haddad, E. [School of Physics, University of the Witwatersrand, Johannesburg 2050 (South Africa); Centre of Excellence in Strong Materials, Physics Building, University of the Witwatersrand, Johannesburg 2050 (South Africa); Shrivastava, S. [School of Physics, University of the Witwatersrand, Johannesburg 2050 (South Africa); Schenkel, T. [E.O. Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Ritter, R.; Kowarik, G.; Aumayr, F. [Institute of Applied Physics, TU Wien-Vienna University of Technology, 1040 Vienna (Austria); Crespo Lopez-Urrutia, J.; Bernitt, S.; Beilmann, C.; Ginzel, R. [Max-Planck Institute for Nuclear Physics, Saupfercheckweg 1, 69117 Heidelberg (Germany)
2013-11-01
We investigate the interaction of slow highly charged ion (SHCI) beams with insulating type Ib diamond (1 1 1) surfaces. Bismuth and Xenon SHCI beams produced using an Electron Beam Ion Trap (EBIT) and an Electron Cyclotron Resonance source (ECR) respectively, are accelerated onto type Ib diamond (1 1 1) surfaces with impact velocities up to ≈0.4 υ{sub Bohr}. SHCIs with charge states corresponding to potential energies between 4.5 keV and 110 keV are produced for this purpose. Atomic Force Microscopy analysis (AFM) of the diamond surfaces following SHCI impact reveals surface morphological modifications characterized as nanoscale craters (nano-craters). To interpret the results from Tapping Mode AFM analysis of the irradiated diamond surfaces we discuss the interplay between kinetic and potential energy in nano-crater formation using empirical data together with Stopping and Range of Ions in Matter (SRIM) Monte Carlo Simulations.
16. SLC injector simulation and tuning for high charge transport
International Nuclear Information System (INIS)
Yeremian, A.D.; Miller, R.H.; Clendenin, J.E.; Early, R.A.; Ross, M.C.; Turner, J.L.; Wang, J.W.
1992-08-01
We have simulated the SLC injector from the thermionic gun through the first accelerating section and used the resulting parameters to tune the injector for optimum performance and high charge transport. Simulations are conducted using PARMELA, a three-dimensional ray-trace code with a two-dimensional space-charge model. The magnetic field profile due to the existing magnetic optics is calculated using POISSON, while SUPERFISH is used to calculate the space harmonics of the various bunchers and the accelerator cavities. The initial beam conditions in the PARMELA code are derived from the EGUN model of the gun. The resulting injector parameters from the PARMELA simulation are used to prescribe experimental settings of the injector components. The experimental results are in agreement with the results of the integrated injector model
17. SLC injector simulation and tuning for high charge transport
International Nuclear Information System (INIS)
Yeremian, A.D.; Miller, R.H.; Clendenin, J.E.; Early, R.A.; Ross, M.C.; Turner, J.L.; Wang, J.W.
1992-01-01
We have simulated the SLC injector from the thermionic gun through the first accelerating section and used the resulting parameters to tune the injector for optimum performance and high charge transport. Simulations are conducted using PARMELA, a three-dimensional space-charge model. The magnetic field profile due to the existing magnetic optics is calculated using POISSON, while SUPERFISH is used to calculate the space harmonics of the various bunchers and the accelerator cavities. The initial beam conditions in the PARMELA code are derived from the EGUN model of the gun. The resulting injector parameters from the PARMELA simulation are used to prescribe experimental settings of the injector components. The experimental results are in agreement with the results of the integrated injector model. (Author) 5 figs., 7 refs
18. Charge redistribution and properties of high-temperature superconductors
International Nuclear Information System (INIS)
Khomskii, D.I.; Kusmartsev, F.V.
1992-01-01
We show that in high-T c superconductors (HTSC) with two groups of electrons (e.g., holes in CuO 2 planes and in a ''reservoir'') there should exist a charge redistribution with the temperature: the hole concentration N h in ''active'' superconducting CuO 2 planes increases below T c . This effect may explain structural changes such as the shift of the apical oxygen atom, anomalous thermal expansion, the shift of nuclear quadrupole resonance lines, the change of the positron lifetime, and the modification of the ion channeling below T c . Some other possible consequences of the charge redistribution (the modification of the temperature dependence of a gap Δ and of the ratio 2Δ 0 /T c , the phenomena at a contact of HTSC with normal metals and semiconductors) are discussed
19. High sensitivity troponin and valvular heart disease.
Science.gov (United States)
McCarthy, Cian P; Donnellan, Eoin; Phelan, Dermot; Griffin, Brian P; Enriquez-Sarano, Maurice; McEvoy, John W
2017-07-01
Blood-based biomarkers have been extensively studied in a range of cardiovascular diseases and have established utility in routine clinical care, most notably in the diagnosis of acute coronary syndrome (e.g., troponin) and the management of heart failure (e.g., brain-natriuretic peptide). The role of biomarkers is less well established in the management of valvular heart disease (VHD), in which the optimal timing of surgical intervention is often challenging. One promising biomarker that has been the subject of a number of recent VHD research studies is high sensitivity troponin (hs-cTn). Novel high-sensitivity assays can detect subclinical myocardial damage in asymptomatic individuals. Thus, hs-cTn may have utility in the assessment of asymptomatic patients with severe VHD who do not have a clear traditional indication for surgical intervention. In this state-of-the-art review, we examine the current evidence for hs-cTn as a potential biomarker in the most commonly encountered VHD conditions, aortic stenosis and mitral regurgitation. This review provides a synopsis of early evidence indicating that hs-cTn has promise as a biomarker in VHD. However, the impact of its measurement on clinical practice and VHD outcomes needs to be further assessed in prospective studies before routine clinical use becomes a reality. Copyright © 2017 Elsevier Inc. All rights reserved.
20. The noise analysis and optimum filtering techniques for a two-dimensional position sensitive orthogonal strip gamma ray detector employing resistive charge division
International Nuclear Information System (INIS)
Gerber, M.S.; Muller, D.W.
1976-01-01
The analysis of an orthogonal strip, two-dimensional position sensitive high purity germanium gamma ray detector is discussed. Position sensitivity is obtained by connecting each electrode strip on the detector to a resistor network. Charge, entering the network, divides in relation to the resistance between its entry point and the virtual earth points of the charge sensitive preamplifiers located at the end of each resistor network. The difference of the voltage pulses at the output of each preamplifier is proportional to the position at which the charge entered the resistor network and the sum of the pulse is proportional to the energy of the detected gamma ray. The analysis and spatial noise resolution is presented for this type of position sensitive detector. The results of the analysis show that the position resolution is proportional to the square root of the filter amplifier's output pulse time constant and that for energy measurement the resolution is maximized at the filter amplifier's noise corner time constant. The design of the electronic noise filtering system for the prototype gamma ray camera was based on the mathematical energy and spatial resolution equations. For the spatial channel a Gaussian trapezoidal filtering system was developed. Gaussian filtering was used for the energy channel. The detector noise model was verified by taking rms noise measurements of the filtered energy and spatial pulses from resistive readout charge dividing detectors. These measurements were within 10% of theory. (Auth.)
1. Relativistic, QED and nuclear effects in highly charged ions revealed by resonant electron-ion recombination in storage rings
OpenAIRE
Schippers, Stefan
2008-01-01
Dielectronic recombination (DR) of few-electron ions has evolved into a sensitive spectroscopic tool for highly charged ions. This is due to technological advances in electron-beam preparation and ion-beam cooling techniques at heavy-ion storage rings. Recent experiments prove unambiguously that DR collision spectroscopy has become sensitive to 2nd order QED and to nuclear effects. This review discusses the most recent developments in high-resolution spectroscopy of low-energy DR resonances, ...
2. Highly sensitive high resolution Raman spectroscopy using resonant ionization methods
International Nuclear Information System (INIS)
Owyoung, A.; Esherick, P.
1984-05-01
In recent years, the introduction of stimulated Raman methods has offered orders of magnitude improvement in spectral resolving power for gas phase Raman studies. Nevertheless, the inherent weakness of the Raman process suggests the need for significantly more sensitive techniques in Raman spectroscopy. In this we describe a new approach to this problem. Our new technique, which we call ionization-detected stimulated Raman spectroscopy (IDSRS), combines high-resolution SRS with highly-sensitive resonant laser ionization to achieve an increase in sensitivity of over three orders of magnitude. The excitation/detection process involves three sequential steps: (1) population of a vibrationally excited state via stimulated Raman pumping; (2) selective ionization of the vibrationally excited molecule with a tunable uv source; and (3) collection of the ionized species at biased electrodes where they are detected as current in an external circuit
3. Search for highly interacting fractionally charged particles at PEP
International Nuclear Information System (INIS)
Wlodzimierz, G.
1982-01-01
Fractionally charged, highly interacting particles produced in e + e - annihilation at 20 GeV c.m. energy have been search for. The experiment was performed at the positron electron storage ring (PEP) at the Stanford Linear Accelerator Center (SLAC). The search used in the innermost part of the two-arm Free Quark Search (FQS) detector. This part was called the Thin Front End (TFE) and it covered 1/3 of the full solid angle. Each of its arms consisted of five multiwire proportional chambers (MWPC's), used for tracking and dE/dx measurement, and three hodoscopes of 0.16 cm thick Pilot F scintillator. The total thickness of the five MWPC's and the beam pipe was 0.007 hadronic collision lengths (lambda/sub c/). No candidates for fractionally charged particles were found. Upper limits on R/sub q anti q/ = sigma(e + e - →q anti q)/sigma(e + e - →μμ) are between: (1) 0.7% to 7% for quark interaction lengths (lambda/sub q/) equal to lambda/sub c/ and between 3% and 33% for lambda/sub q/ = 100lambda/sub c/ for Q = 1/3e quark charge and for quark masses up to 13 GeV/c 2 ; (2) 2% to 38% for lambda/sub q/ - lambda/sub c/ and from 7% to 160% for lambda/sub q/ = 100lambda/sub c/ for Q = 2/3e quark charge and for masses up to 8 GeV/c 2 . In the inclusive production channel the upper limits on R/sub q/ = sigma(e + e - →qqX)/sigma(e + e - →μμ) are for charge 1/3e only. R/sub q/ varies from 2% to 11% for lambda/sub q/ = lambda/sub c/ and from 3% to 16% for lambda/sub q/ = 100lambda/sub c/ and for quark masses up to 6.5 GeV/c 2 . These are the first limits on the production of fractionally charged particles with lambda/sub q/ = 100lambda/sub c/
4. Temperature Dependence of Charge Localization in High-Mobility, Solution-Crystallized Small Molecule Semiconductors Studied by Charge Modulation Spectroscopy
DEFF Research Database (Denmark)
Meneau, Aurélie Y. B.; Olivier, Yoann; Backlund, Tomas
2016-01-01
In solution-processable small molecule semiconductors, the extent of charge carrier wavefunction localization induced by dynamic disorder can be probed spectroscopically as a function of temperature using charge modulation spectroscopy (CMS). Here, it is shown based on combined fi eld-effect tran......In solution-processable small molecule semiconductors, the extent of charge carrier wavefunction localization induced by dynamic disorder can be probed spectroscopically as a function of temperature using charge modulation spectroscopy (CMS). Here, it is shown based on combined fi eld......-effect transistor and CMS measurements as a function of temperature that in certain molecular semiconductors, such as solution-processible pentacene, charge carriers become trapped at low temperatures in environments in which the charges become highly localized on individual molecules, while in some other molecules...
5. Anisotropy in highly charged ion induced molecule fragmentation
International Nuclear Information System (INIS)
Juhasz, Z.; Sulik, B.; Fremont, F.; Chesnel, J.Y.; Hajaji, A.
2006-01-01
Complete text of publication follows. Studying fragmentation processes of biologically relevant molecules due to highly charged ion impact is important to understand radiation damage in biological tissues. Energy spectra of the charged molecule fragments may reveal the different fragmentation patterns meanwhile the angular distributions of the fragments characterize the dependence of fragmentation probability on the initial orientation of the molecule. The research to explore the angular distribution of the molecule fragments has only recently been started[1]. In 2006 we performed measurements at ARIBE facility at GANIL, Caen (France), in order to investigate orientation effects in molecule fragmentation. Fragmentation of H 2 O, C 6 H 6 and CH 4 , which represent different level of symmetry, have been studied by 60 keV N 6+ ion impact. Energy spectra of the charged fragments at different observation angles have been taken. As our example spectra show the different protonic peaks can be attributed to different fragmentation processes. Significant anisotropy can be seen in the different processes. The strongest evidence for the anisotropy can be seen in the spectra of C 6 H 6 , where the spectra appear isotropic in almost the whole observed energy range except one peak, which has a strong angular dependence and is maximal around 90 deg. (author)
6. Highly charged cyanine fluorophores for trafficking scaffold degradation
International Nuclear Information System (INIS)
Owens, Eric A; Alyabyev, Sergey; Henary, Maged; Hyun, Hoon; Kim, Soon Hee; Lee, Jeong Heon; Park, GwangLi; Ashitate, Yoshitomo; Choi, Jungmun; Hong, Gloria H; Choi, Hak Soo; Lee, Sang Jin; Khang, Gilson
2013-01-01
Biodegradable scaffolds have been extensively used in the field of tissue engineering and regenerative medicine. However, noninvasive monitoring of in vivo scaffold degradation is still lacking. In order to develop a real-time trafficking technique, a series of meso-brominated near-infrared (NIR) fluorophores were synthesized and conjugated to biodegradable gelatin scaffolds. Since the pentamethine cyanine core is highly lipophilic, the side chain of each fluorophore was modified with either quaternary ammonium salts or sulfonate groups. The physicochemical properties such as lipophilicity and net charge of fluorophores played a key role in the fate of NIR-conjugated scaffolds in vivo after biodegradation. The positively charged fluorophore-conjugated scaffold fragments were found in salivary glands, lymph nodes, and most of the hepatobiliary excretion route. However, halogenated fluorophores intensively accumulated into lymph nodes and the liver. Interestingly, balanced-charged gelatin scaffolds were degraded into urine in a short period of time. These results demonstrate that the noninvasive optical imaging using NIR fluorophores can be useful for the translation of biodegradable scaffolds into the clinic. (paper)
7. Super TOF secondary ion mass spectroscopy using very highly charged primary ions up to Th70+
International Nuclear Information System (INIS)
Briere, M.A.; Schenkel, T.; Schneider, D.
1995-01-01
The LLNL Electron Beam Ion Trap (EBIT) has made low emittance beams of slow highly charged ions available for ion-solid interaction studies. Such interactions feature the dominance of electronic over collisional effects, and the shock waves generated by the ionized target atoms can desorb large numbers of large molecular species from the surface. This paper presents the first systematic study of the sputtering process due to the incidence of slow very highly charged ions; Th 70+ ions are extracted from EBIT at 7 keV * q and directed onto thin SiO 2 films on Si. Results suggest secondary ion yields of up to 25 per incident ion for Th 70+ (secondary ion yield is increased over that for singly or moderately charged ions). Correlations of the negative, positive, and negative cluster ion yields show promise for application of highly charged ion induced sputtering for enhanced sensitivity and quantitative (absolute) SIMS analysis of deep submicron scale surface layers and polymeric and biomolecular material analysis
8. Small electrostatic storage rings; also for highly charged ions?
International Nuclear Information System (INIS)
Moeller, S.P.; Pedersen, U.V.
2001-01-01
Two years ago, a small electrostatic storage ring ELISA (electrostatic ion storage ring, Aarhus) was put into operation. The design of this small 7 m circumference ring was based on electrostatic deflection plates and quadrupoles. This is in contrast to the larger ion storage rings, which are based on magnetic focusing and deflection. The result is a small, relatively inexpensive, storage ring being able to store ions of any mass and any charge at low energy ( -11 mbar resulting in storage times of several tens of seconds for singly charged ions. The maximum number of singly charged ions that can be stored is a few 10 7 . Several experiments have already been performed in ELISA. These include lifetime studies of metastable ions and studies of fullerenes and metal-cluster ions. Lasers are also used for excitation of the circulating ions. Heating/cooling of the ring is possible. Cooling of the ring leads to significantly lower pressures, and correspondingly longer lifetimes. A change of the temperature of the vacuum chambers surrounding the ion beam also leads to a change of the spectrum of the black-body radiation, which has a significant influence on weakly bound negative ions. At the time of writing, at least two other electrostatic storage rings are being built, and more are planned. In the following, the electrostatic storage ring ELISA will be described, and results from some of the initial experiments demonstrating the performance will be shown. The relative merits of such a ring, as opposed to the larger magnetic rings and the smaller ion traps will be discussed. The potential for highly charged ions will be briefly mentioned. (orig.)
9. Self-Assembling of Tetradecylammonium Chain on Swelling High Charge Micas (Na-Mica-3 and Na-Mica-2): Effect of Alkylammonium Concentration and Mica Layer Charge.
Science.gov (United States)
Pazos, M Carolina; Cota, Agustín; Osuna, Francisco J; Pavón, Esperanza; Alba, María D
2015-04-21
A family of tetradecylammonium micas is synthesized using synthetic swelling micas with high layer charge (Na(n)Si(8-n)Al(n)Mg6F4O20·XH2O, where n = 2 and 3) exchanged with tetradecylammonium cations. The molecular arrangement of the surfactant is elucidated on the basis of XRD patterns and DTA. The ordering conformation of the surfactant molecules into the interlayer space of micas is investigated by IR/FT, (13)C, (27)Al, and (29)Si MAS NMR. The structural arrangement of the tetradecylammonium cation in the interlayer space of high-charge micas is more sensitive to the effect of the mica layer charge at high concentration. The surfactant arrangement is found to follow the bilayer-paraffin model for all values of layer charge and surfactant concentration. However, at initial concentration below the mica CEC, a lateral monolayer is also observed. The amount of ordered conformation all-trans is directly proportional to the layer charge and surfactant concentration.
10. A CMOS In-Pixel CTIA High Sensitivity Fluorescence Imager.
Science.gov (United States)
Murari, Kartikeya; Etienne-Cummings, Ralph; Thakor, Nitish; Cauwenberghs, Gert
2011-10-01
Traditionally, charge coupled device (CCD) based image sensors have held sway over the field of biomedical imaging. Complementary metal oxide semiconductor (CMOS) based imagers so far lack sensitivity leading to poor low-light imaging. Certain applications including our work on animal-mountable systems for imaging in awake and unrestrained rodents require the high sensitivity and image quality of CCDs and the low power consumption, flexibility and compactness of CMOS imagers. We present a 132×124 high sensitivity imager array with a 20.1 μm pixel pitch fabricated in a standard 0.5 μ CMOS process. The chip incorporates n-well/p-sub photodiodes, capacitive transimpedance amplifier (CTIA) based in-pixel amplification, pixel scanners and delta differencing circuits. The 5-transistor all-nMOS pixel interfaces with peripheral pMOS transistors for column-parallel CTIA. At 70 fps, the array has a minimum detectable signal of 4 nW/cm(2) at a wavelength of 450 nm while consuming 718 μA from a 3.3 V supply. Peak signal to noise ratio (SNR) was 44 dB at an incident intensity of 1 μW/cm(2). Implementing 4×4 binning allowed the frame rate to be increased to 675 fps. Alternately, sensitivity could be increased to detect about 0.8 nW/cm(2) while maintaining 70 fps. The chip was used to image single cell fluorescence at 28 fps with an average SNR of 32 dB. For comparison, a cooled CCD camera imaged the same cell at 20 fps with an average SNR of 33.2 dB under the same illumination while consuming over a watt.
11. CALDER: High-sensitivity cryogenic light detectors
International Nuclear Information System (INIS)
Casali, N.; Bellini, F.; Cardani, L.
2017-01-01
The current bolometric experiments searching for rare processes such as neutrinoless double-beta decay or dark matter interaction demand for cryogenic light detectors with high sensitivity, large active area and excellent scalability and radio-purity in order to reduce their background budget. The CALDER project aims to develop such kind of light detectors implementing phonon-mediated Kinetic Inductance Detectors (KIDs). The goal for this project is the realization of a 5 × 5 cm"2 light detector working between 10 and 100mK with a baseline resolution RMS below 20 eV. In this work the characteristics and the performances of the prototype detectors developed in the first project phase will be shown.
12. Structural Arrangement of Water Molecules around Highly Charged Nanoparticles: Molecular Dynamics Simulation
International Nuclear Information System (INIS)
Kim, Eunae; Yeom, Min Sun
2014-01-01
Molecular dynamics simulations were performed to understand the structural arrangement of water molecules around highly charged nanoparticles under aqueous conditions. The effect of two highly charged nanoparticles on the solvation charge asymmetry has been examined. We calculated the radial distribution functions of the components of water molecules around nanoparticles which have four charge types at two different salt concentrations. Even though the distributions of water molecules surrounding a sodium ion and a chloride ion are hardly affected by the charges of nanoparticles and the salt concentrations, those around highly charged nanoparticles are strongly influenced by the charges of nanoparticles, but hardly by the charges of nanoparticles and salt concentrations. We find that the distributions of hydrogen atoms in water molecules around one highly charged nanoparticle are dependent on the magnitude of the nanoparticle charge
Energy Technology Data Exchange (ETDEWEB)
Valente, M.; Malano, F. [Instituto de Fisica Enrique Gaviola, Oficina 102 FaMAF - UNC, Av. Luis Medina Allende, Ciudad Universitaria, 5000 Cordoba (Argentina); Molina, W.; Vedelago, J., E-mail: valente@famac.unc.edu.ar [Laboratorio de Investigaciones e Instrumentacion en Fisica Aplicada a la Medicina e Imagenes por Rayos X, Laboratorio 448 FaMAF - UNC, Ciudad Universitaria, 5000 Cordoba (Argentina)
2014-08-15
International Nuclear Information System (INIS)
Valente, M.; Malano, F.; Molina, W.; Vedelago, J.
2014-08-01
15. Highly charged ions generated with intense laser beams
Czech Academy of Sciences Publication Activity Database
Krása, Josef; Jungwirth, Karel; Králiková, Božena; Láska, Leoš; Pfeifer, Miroslav; Rohlena, Karel; Skála, Jiří; Ullschmied, Jiří; Hnatowicz, Vladimír; Peřina, Vratislav; Badziak, J.; Parys, P.; Wolowski, J.; Woryna, E.; Szydlowski, A.
2003-01-01
Roč. 205, - (2003), s. 355-359 ISSN 0168-583X. [International Symposium on Swift Heavy Ions in Matter /5./. Taormina-Giardini Naxos, 22.05.2002-25.05.2002] R&D Projects: GA MŠk LN00A100 Grant - others:HPRI(XE) CT-1999-00053; IAEA(XE) 11535/RO Institutional research plan: CEZ:AV0Z2043910; CEZ:AV0Z1010921 Keywords : laser-produced plasma * highly charged ions * ion implantation * windowless electron multiplier Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.041, year: 2003
16. Atomic physics with highly charged ions. Progress report
Energy Technology Data Exchange (ETDEWEB)
Richard, P.
1994-08-01
The study of inelastic collision phenomena with highly charged projectile ions and the interpretation of spectral features resulting from these collisions remain as the major focal points in the atomic physics research at the J.R. Macdonald Laboratory, Kansas State University, Manhattan, Kansas. The title of the research project, Atomic Physics with Highly Charged Ions, speaks to these points. The experimental work in the past few years has divided into collisions at high velocity using the primary beams from the tandem and LINAC accelerators and collisions at low velocity using the CRYEBIS facility. Theoretical calculations have been performed to accurately describe inelastic scattering processes of the one-electron and many-electron type, and to accurately predict atomic transition energies and intensities for x rays and Auger electrons. Brief research summaries are given for the following: (1) electron production in ion-atom collisions; (2) role of electron-electron interactions in two-electron processes; (3) multi-electron processes; (4) collisions with excited, aligned, Rydberg targets; (5) ion-ion collisions; (6) ion-molecule collisions; (7) ion-atom collision theory; and (8) ion-surface interactions.
17. High-order space charge effects using automatic differentiation
International Nuclear Information System (INIS)
Reusch, Michael F.; Bruhwiler, David L.
1997-01-01
The Northrop Grumman Topkark code has been upgraded to Fortran 90, making use of operator overloading, so the same code can be used to either track an array of particles or construct a Taylor map representation of the accelerator lattice. We review beam optics and beam dynamics simulations conducted with TOPKARK in the past and we present a new method for modeling space charge forces to high-order with automatic differentiation. This method generates an accurate, high-order, 6-D Taylor map of the phase space variable trajectories for a bunched, high-current beam. The spatial distribution is modeled as the product of a Taylor Series times a Gaussian. The variables in the argument of the Gaussian are normalized to the respective second moments of the distribution. This form allows for accurate representation of a wide range of realistic distributions, including any asymmetries, and allows for rapid calculation of the space charge fields with free space boundary conditions. An example problem is presented to illustrate our approach
18. High-order space charge effects using automatic differentiation
International Nuclear Information System (INIS)
Reusch, M.F.; Bruhwiler, D.L.; Computer Accelerator Physics Conference Williamsburg, Virginia 1996)
1997-01-01
The Northrop Grumman Topkark code has been upgraded to Fortran 90, making use of operator overloading, so the same code can be used to either track an array of particles or construct a Taylor map representation of the accelerator lattice. We review beam optics and beam dynamics simulations conducted with TOPKARK in the past and we present a new method for modeling space charge forces to high-order with automatic differentiation. This method generates an accurate, high-order, 6-D Taylor map of the phase space variable trajectories for a bunched, high-current beam. The spatial distribution is modeled as the product of a Taylor Series times a Gaussian. The variables in the argument of the Gaussian are normalized to the respective second moments of the distribution. This form allows for accurate representation of a wide range of realistic distributions, including any asymmetries, and allows for rapid calculation of the space charge fields with free space boundary conditions. An example problem is presented to illustrate our approach. copyright 1997 American Institute of Physics
19. Imaging the Anomalous Charge Distribution Inside CsPbBr3 Perovskite Quantum Dots Sensitized Solar Cells.
Science.gov (United States)
Panigrahi, Shrabani; Jana, Santanu; Calmeiro, Tomás; Nunes, Daniela; Martins, Rodrigo; Fortunato, Elvira
2017-10-24
Highly luminescent CsPbBr 3 perovskite quantum dots (QDs) have gained huge attention in research due to their various applications in optoelectronics, including as a light absorber in photovoltaic solar cells. To improve the performances of such devices, it requires a deeper knowledge on the charge transport dynamics inside the solar cell, which are related to its power-conversion efficiency. Here, we report the successful fabrication of an all-inorganic CsPbBr 3 perovskite QD sensitized solar cell and the imaging of anomalous electrical potential distribution across the layers of the cell under different illuminations using Kelvin probe force microscopy. Carrier generation, separation, and transport capacity inside the cells are dependent on the light illumination. Large differences in surface potential between electron and hole transport layers with unbalanced carrier separation at the junction have been observed under white light (full solar spectrum) illumination. However, under monochromatic light (single wavelength of solar spectrum) illumination, poor charge transport occurred across the junction as a consequence of less difference in surface potential between the active layers. The outcome of this study provides a clear idea on the carrier dynamic processes inside the cells and corresponding surface potential across the layers under the illumination of different wavelengths of light to understand the functioning of the solar cells and ultimately for the improvement of their photovoltaic performances.
20. Impact of measuring electron tracks in high-resolution scientific charge-coupled devices within Compton imaging systems
International Nuclear Information System (INIS)
Chivers, D.H.; Coffer, A.; Plimley, B.; Vetter, K.
2011-01-01
We have implemented benchmarked models to determine the gain in sensitivity of electron-tracking based Compton imaging relative to conventional Compton imaging by the use of high-resolution scientific charge-coupled devices (CCD). These models are based on the recently demonstrated ability of electron-tracking based Compton imaging by using fully depleted scientific CCDs. Here we evaluate the gain in sensitivity by employing Monte Carlo simulations in combination with advanced charge transport models to calculate two-dimensional charge distributions corresponding to experimentally obtained tracks. In order to reconstruct the angle of the incident γ-ray, a trajectory determination algorithm was used on each track and integrated into a back-projection routine utilizing a geodesic-vertex ray tracing technique. Analysis was performed for incident γ-ray energies of 662 keV and results show an increase in sensitivity consistent with tracking of the Compton electron to approximately ±30 o .
1. Photo-induced charge transfer at heterogeneous interfaces: Dye-sensitized tin disulfide, the theory and the experiment
International Nuclear Information System (INIS)
Lanzafame, J.M.
1993-01-01
The study of photo-induced charge transfer is an endeavor that spans the entire industrial period of man's history. Its great importance demands an ever greater understanding of its underlying principles. The work discussed here attempts to probe elementary aspects of the charge transfer process. Investigations into the theory of charge transfer reactions are made in an attempt to isolate the relevant parameters. An analytical discussion is made of a simple Golden Rule type rate equation to describe the transfer kinetics. Then a quantum simulation is carried out to follow the wavefunction propagation as a test of the applicability of the assumptions made in deriving the simpler rate equation. Investigation of charge transfer at surfaces is bet served by the application of ultrafast optical spectroscopies to probe carrier dynamics. A discussion of the properties of the short pulse laser systems employed is included along with a discussion of the different optical spectroscopies available. These tools are then brought to bear upon dye-sensitized SnS 2 , a model system for the study of charge injection processes. The unique properties of the semiconductor are discussed with respect to the charge transfer process. The unique properties of the semiconductor are discussed with respect to the charge transfer process. The optical experiments performed on the dye/SnS 2 systems elucidate the fundamental carrier dynamics and these dynamics are discussed within the theoretical framework to provide a complete picture of the charge transfer kinetics
2. Enhanced Charge Separation Efficiency in Pyridine-Anchored Phthalocyanine-Sensitized Solar Cells by Linker Elongation.
Science.gov (United States)
Ikeuchi, Takuro; Agrawal, Saurabh; Ezoe, Masayuki; Mori, Shogo; Kimura, Mutsumi
2015-11-01
A series of zinc phthalocyanine sensitizers (PcS22-24) having a pyridine anchoring group are designed and synthesized to investigate the structural dependence on performance in dye-sensitized solar cells. The pyridine-anchor zinc phthalocyanine sensitizer PcS23 shows 79 % incident-photon to current-conversion efficiency (IPCE) and 6.1 % energy conversion efficiency, which are comparable with similar phthalocyanine dyes having a carboxylic acid anchoring group. Based on DFT calculations, the high IPCE is attributed with the mixture of an excited-state molecular orbital of the sensitizer and the orbitals of TiO2 . Between pyridine and carboxylic acid anchor dyes, opposite trends are observed in the linker-length dependence of the IPCE. The red-absorbing PcS23 is applied for co-sensitization with a carboxyl-anchor organic dye D131 that has a complementary spectral response. The site-selective adsorption of PcS23 and D131 on the TiO2 surface results in a panchromatic photocurrent response for the whole visible-light region of sun light. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
3. Transportable high sensitivity small sample radiometric calorimeter
International Nuclear Information System (INIS)
Wetzel, J.R.; Biddle, R.S.; Cordova, B.S.; Sampson, T.E.; Dye, H.R.; McDow, J.G.
1998-01-01
A new small-sample, high-sensitivity transportable radiometric calorimeter, which can be operated in different modes, contains an electrical calibration method, and can be used to develop secondary standards, will be described in this presentation. The data taken from preliminary tests will be presented to indicate the precision and accuracy of the instrument. The calorimeter and temperature-controlled bath, at present, require only a 30-in. by 20-in. tabletop area. The calorimeter is operated from a laptop computer system using unique measurement module capable of monitoring all necessary calorimeter signals. The calorimeter can be operated in the normal calorimeter equilibration mode, as a comparison instrument, using twin chambers and an external electrical calibration method. The sample chamber is 0.75 in (1.9 cm) in diameter by 2.5 in. (6.35 cm) long. This size will accommodate most 238 Pu heat standards manufactured in the past. The power range runs from 0.001 W to <20 W. The high end is only limited by sample size
4. Electromagnetic Charge Radius of the Pion at High Precision
Science.gov (United States)
Ananthanarayan, B.; Caprini, Irinel; Das, Diganta
2017-09-01
We present a determination of the pion charge radius from high precision data on the pion vector form factor from both timelike and spacelike regions, using a novel formalism based on analyticity and unitarity. At low energies, instead of the poorly known modulus of the form factor, we use its phase, known with high accuracy from Roy equations for π π elastic scattering via the Fermi-Watson theorem. We use also the values of the modulus at several higher timelike energies, where the data from e+e- annihilation and τ decay are mutually consistent, as well as the most recent measurements at spacelike momenta. The experimental uncertainties are implemented by Monte Carlo simulations. The results, which do not rely on a specific parametrization, are optimal for the given input information and do not depend on the unknown phase of the form factor above the first inelastic threshold. Our prediction for the charge radius of the pion is rπ=(0.657 ±0.003 ) fm , which amounts to an increase in precision by a factor of about 2.7 compared to the Particle Data Group average.
5. Performance of the PHIN High Charge Photo Injector
CERN Document Server
Petrarca, M; Doebert, S; Dabrowski, A; Divall, M; Fedoseev, V; Lebas, N; Lefevre, T; Losito, R; Egger, D; Mete, O
2010-01-01
The high charge PHIN photo injector is studied at CERN as an electron source for the CLIC Test Facility (CTF3) drive beam as an alternative to the present thermionic gun. The objective of PHIN is to demonstrate the feasibility of a laser-based electron source for CLIC. The photo injector operates with a 2.5 cell, 3 GHz RF gun using a Cs2Te photocathode illuminated by UV laser pulses generated by amplifying and frequency quadrupling the signal from a Nd:YLF oscillator running at 1.5GHz. The challenge is to generate a beam structure of 1908 micro bunches with 2.33nC per micro bunch at 1.5GHz leading to a high integrated train charge of 4446nC and nominal beam energy of 5.5MeV with current stability below 1%. In this paper we report and discuss the time resolved transverse and longitudinal beam parameters measurements. The performance of the photo cathodes made at CERN with a peak quantum efficiency of 18 % is shown as well. Laser pointing and amplitude stability results are discussed taking into account correla...
6. DEPTH-CHARGE static and time-dependent perturbation/sensitivity system for nuclear reactor core analysis. Revision I
International Nuclear Information System (INIS)
White, J.R.
1985-04-01
This report provides the background theory, user input, and sample problems required for the efficient application of the DEPTH-CHARGE system - a code black for both static and time-dependent perturbation theory and data sensitivity analyses. The DEPTH-CHARGE system is of modular construction and has been implemented within the VENTURE-BURNER computational system at Oak Ridge National Laboratory. The DEPTH module (coupled with VENTURE) solves for the three adjoint functions of Depletion Perturbation Theory and calculates the desired time-dependent derivatives of the response with respect to the nuclide concentrations and nuclear data utilized in the reference model. The CHARGE code is a collection of utility routines for general data manipulation and input preparation and considerably extends the usefulness of the system through the automatic generation of adjoint sources, estimated perturbed responses, and relative data sensitivity coefficients. Combined, the DEPTH-CHARGE system provides, for the first time, a complete generalized first-order perturbation/sensitivity theory capability for both static and time-dependent analyses of realistic multidimensional reactor models. This current documentation incorporates minor revisions to the original DEPTH-CHARGE documentation (ORNL/CSD-78) to reflect some new capabilities within the individual codes
7. Application of CMOS charge-sensitive preamplifier in triple-GEM detector
International Nuclear Information System (INIS)
Lai Yongfang; Li Jin; Chinese Academy of Sciences, Beijing; Deng Zhi; Li Yulan; Liu Yinong; Li Yuanjing
2006-01-01
Among the various micro-pattern gas detectors (MPGD) that are available, the gas electron multiplier (GEM) detector is an attractive gas detector that has been used in particle physics experiments. However the GEM detector usually needs thousands of preamplifier units for its large number of micro-pattern readout strips or pads, which leads to considerable difficulties and complexities for front end electronics (FEE). Nowadays, by making use of complementary metal-oxide semiconductor (CMOS)-based application specific integrated circuit (ASIC), it is feasible to integrate hundreds of preamplifier units and other signal process circuits in a small-sized chip, which can be bound to the readout strips or pads of a micro-pattern particle detector (MPPD). Therefore, CMOS ASIC may provide an ideal solution to the readout problem of MPPD. In this article, a triple GEM detector is constructed and one of its readout strips is connected to a CMOS charge-sensitive preamplifier chip. The chip was exposed to an 55 Fe source of 5.9 kev X-ray, and the amplitude spectrum of the chip was tested, and it was found that the energy resolution was approximately 27%, which indicates that the chip can be used in triple GEM detectors. (authors)
8. Charge Sensitive Amplifier (CSA) in cold gas of Liquid Argon (LAr) Time Projection Chamber (TPC)
International Nuclear Information System (INIS)
Bechetoille, E; Mathez, H; Zoccarato, Y
2011-01-01
This paper presents our work on a 8-channel low noise Front-End electronic coupled to a Liquid Argon (LAr) TPC (Time Projection Chamber). Each channel consists of a Charge Sensitive Amplifier (CSA), a band pass filter and a 50 Ohms buffer as line driver. A serial link based on a 'i2c-like' protocol, provides multiple configuration features to the circuit by accessing slow control registers. In this paper, we describe the CSA, the shaper and the slow control part. The feedback network of the CSA is made of a capacitance and a resistor. Their values are respectively 250 fF and 4 MΩ. An input referred noise of, at most, 1500 e- rms must be achieved at -100 deg. C with an input detector capacitance of 250 pF to ensure a correct measurement of the minimal signal of 18000e- (2.88 fC). The power consumption in this cryogenic setup must be less than 40 mW from a 3.3 V power supply.
9. Energy loss and charge exchange processes of high energy heavy ions channeled in crystals
International Nuclear Information System (INIS)
Poizat, J.C.; Andriamonje, S.; Anne, R.; Faria, N.V.d.C.; Chevallier, M.; Cohen, C.; Dural, J.; Farizon-Mazuy, B.; Gaillard, M.J.; Genre, R.; Hage-Ali, M.; Kirsch, R.; L'hoir, A.; Mory, J.; Moulin, J.; Quere, Y.; Remillieux, J.; Schmaus, D.; Toulemonde, M.
1990-01-01
The interaction of moving ions with single crystals is very sensitive to the orientation of the incident beam with respect to the crystalline directions of the target. Our experiments show that high energy heavy ion channeling deeply modifies their slowing down and charge exchange processes. This is due to the fact that channeled ions interact only with outershell target electrons, which means that the electron density they experience is very low and that the binding energy, and then the momentum distribution of these electrons, are quite different from the corresponding average values associated to random incidence. The two experimental studies presented here show the reduction of the energy loss rate for fast channeled heavy ions and illustrate the two aspects of channeling effects on charge exchange, the reduction of electron loss on one hand, and of electron capture on the other hand
10. Space-charge effects in high-energy photoemission
Energy Technology Data Exchange (ETDEWEB)
Verna, Adriano, E-mail: adriano.verna@uniroma3.it [Dipartimento di Scienze, Università degli Studi Roma Tre, Via della Vasca Navale 84, I-00146 Roma (Italy); CNISM Unità di Roma Tre, Via della Vasca Navale 84, I-00146 Roma (Italy); Greco, Giorgia [Dipartimento di Scienze, Università degli Studi Roma Tre, Via della Vasca Navale 84, I-00146 Roma (Italy); Lollobrigida, Valerio [Dipartimento di Scienze, Università degli Studi Roma Tre, Via della Vasca Navale 84, I-00146 Roma (Italy); Scuola Dottorale in Matematica e Fisica, Università Roma Tre, Via della Vasca Navale 84, I-00146 Roma (Italy); Offi, Francesco; Stefani, Giovanni [Dipartimento di Scienze, Università degli Studi Roma Tre, Via della Vasca Navale 84, I-00146 Roma (Italy); CNISM Unità di Roma Tre, Via della Vasca Navale 84, I-00146 Roma (Italy)
2016-05-15
Highlights: • N-body simulations of interacting photoelectrons in hard X-ray experiments. • Secondary electrons have a pivotal role in determining the energy broadening. • Space charge has negligible effects on the photoelectron momentum distribution. • A simple model provides the characteristic time for energy-broadening mechanism. • The feasibility of time-resolved high-energy experiments with FELs is discussed. - Abstract: Pump-and-probe photoelectron spectroscopy (PES) with femtosecond pulsed sources opens new perspectives in the investigation of the ultrafast dynamics of physical and chemical processes at the surfaces and interfaces of solids. Nevertheless, for very intense photon pulses a large number of photoelectrons are simultaneously emitted and their mutual Coulomb repulsion is sufficiently strong to significantly modify their trajectory and kinetic energy. This phenomenon, referred as space-charge effect, determines a broadening and shift in energy for the typical PES structures and a dramatic loss of energy resolution. In this article we examine the effects of space charge in PES with a particular focus on time-resolved hard X-ray (∼10 keV) experiments. The trajectory of the electrons photoemitted from pure Cu in a hard X-ray PES experiment has been reproduced through N-body simulations and the broadening of the photoemission core-level peaks has been monitored as a function of various parameters (photons per pulse, linear dimension of the photon spot, photon energy). The energy broadening results directly proportional to the number N of electrons emitted per pulse (mainly represented by secondary electrons) and inversely proportional to the linear dimension a of the photon spot on the sample surface, in agreement with the literature data about ultraviolet and soft X-ray experiments. The evolution in time of the energy broadening during the flight of the photoelectrons is also studied. Despite its detrimental consequences on the energy
11. Highly sensitive detection of a current ripple
International Nuclear Information System (INIS)
Aoki, Takashi; Gushiken, Tutomu; Nishikigouri, Kazutaka; Kumada, Masayuki.
1996-01-01
In the HIMAC, there are six thyristor-controlled power sources for driving two synchrotrons. These power sources are the three-output terminal power sources which are equipped with positive output, negative output and neutral point for the common mode countermeasures. As electromagnet circuits are connected to the three-output terminal power sources, those are three-line type. In the inside of the power source circuits controlled by thyristors, there is the oscillation peculiar to the power sources, and the variation of voltage induces current spikes. This time, in order to assess the results of the common mode countermeasures in the power source and electromagnet circuits, as one method of cross-check, it is considered that since electromagnet current flows being divided to the bridging resistance and the coil, if attention is paid to the current on bridging resistance side, the ripple components of common mode and normal mode can be detected with high sensitivity, and this was verified. The present state of heightening the performance of synchrotron power sources is explained. The cross-check of the method of assessing the performance of electromagnet power sources is reported. The method of measuring ripple current and the results of the measurement are reported. (K.I.)
12. Development of high sensitivity radon detectors
CERN Document Server
Takeuchi, Y; Kajita, T; Tasaka, S; Hori, H; Nemoto, M; Okazawa, H
1999-01-01
High sensitivity detectors for radon in air and in water have been developed. We use electrostatic collection and a PIN photodiode for these detectors. Calibration systems have been also constructed to obtain collection factors. As a result of the calibration study, the absolute humidity dependence of the radon detector for air is clearly observed in the region less than about 1.6 g/m sup 3. The calibration factors of the radon detector for air are 2.2+-0.2 (counts/day)/(mBq/m sup 3) at 0.08 g/m sup 3 and 0.86+-0.06 (counts/day)/(mBq/m sup 3) at 11 g/m sup 3. The calibration factor of the radon detector for water is 3.6+-0.5 (counts/day)/(mBq/m sup 3). The background level of the radon detector for air is 2.4+-1.3 counts/day. As a result, one standard deviation excess of the signal above the background of the radon detector for air should be possible for 1.4 mBq/m sup 3 in a one-day measurement at 0.08 g/m sup 3.
13. A modified space charge routine for high intensity bunched beams
International Nuclear Information System (INIS)
Lapostolle, P.; Garnett, R.W.; Wangler, T.P.
1996-01-01
In 1991 a space charge calculation for bunched beam with a three-dimensional ellipsoid was proposed, replacing the usual SCHEFF routines. It removes the cylindrical symmetry required in SCHEFF and avoids the point to point interaction computation, whose number of simulation points is limited. This routine has now been improved with the introduction of two or three ellipsoids giving a good representation of the complex non-symmetrical form of the bunch (unlike the 3-d ellipsoidal assumption). The ellipsoidal density distributions are computed with a new method, avoiding the difficulty encountered near the centre (the axis in 2-d problems) by the previous method. It also provides a check of the ellipsoidal symmetry for each part of the distribution. Finally, the Fourier analysis reported in 1991 has been replaced by a very convenient Hermite expansion, which gives a simple but accurate representation of practical distributions. Comparisons with other space charge routines have been made, particularly with the ones applying other techniques such as SCHEFF. Introduced in the versatile beam dynamics code DYNAC, it should provide a good tool for the study of the various parameters responsible for the halo formation in high intensity linacs. (orig.)
14. Inhibition of charge recombination for enhanced dye-sensitized solar cells and self-powered UV sensors by surface modification
Energy Technology Data Exchange (ETDEWEB)
Chu, Liang, E-mail: chuliang@njupt.edu.cn [Advanced Energy Technology Center, Nanjing University of Posts and Telecommunications (NUPT), Nanjing 210046 (China); Wuhan National Laboratory for Optoelectronics (WNLO)-School of Physics, Huazhong University of Science and Technology (HUST), Wuhan 430074 (China); Qin, Zhengfei; Liu, Wei [School of Materials Science and Engineering (SMSE), Nanjing University of Posts and Telecommunications (NUPT), Nanjing 210046 (China); Ma, Xin’guo, E-mail: maxg2013@sohu.com [Hubei Collaborative Innovation Center for High-efficiency Utilization of Solar Energy, Hubei University of Technology, Wuhan 430068 (China)
2016-12-15
Graphical abstract: Inhibition of charge recombination was utilized to prolong electrode lifetime in dye-sensitized solar cells (DSSCs) and self-powered UV sensors based on TiO{sub 2}-modified SnO{sub 2} photoelectrodes. The electrochemical impedance spectroscopy and open-circuit voltage decay measurements indicated that the electron lifetime was significantly prolonged in DSSCs after TiO{sub 2} modification. And in self-powered UV sensors, the sensitivity and response time were enhanced. - Highlights: • The surface modification to inhibit charge recombination was utilized in photovoltaic devices. • Inhibition of charge recombination can prolong electrode lifetime in photovoltaic devices. • Enhanced DSSCs and self-powered UV sensors based on SnO{sub 2} photoelectrodes were obtained by TiO{sub 2} modification. - Abstract: The surface modification to inhibit charge recombination was utilized in dye-sensitized solar cells (DSSCs) and self-powered ultraviolet (UV) sensors based on SnO{sub 2} hierarchical microspheres by TiO{sub 2} modification. For DSSCs with SnO{sub 2} photoelectrodes modified by TiO{sub 2}, the power conversion efficiency (PCE) was improved from 1.40% to 4.15% under standard AM 1.5G illumination (100 mW/cm{sup 2}). The electrochemical impedance spectroscopy and open-circuit voltage decay measurements indicated that the charge recombination was effectively inhibited, resulting in long electron lifetime. For UV sensors with SnO{sub 2} photoelectrodes modified by TiO{sub 2} layer, the self-powered property was more obvious, and the sensitivity and response time were enhanced from 91 to 6229 and 0.15 s to 0.055 s, respectively. The surface modification can engineer the interface energy to inhibit charge recombination, which is a desirable approach to improve the performance of photoelectric nanodevice.
15. Experimental investigation on the use of highly charged nanoparticles to improve the stability of weakly charged colloidal system.
Science.gov (United States)
2015-09-15
The present work highlighted on the implementation of a unique concept for stabilizing colloids at their incipiently low charge potential. A highly charged nanoparticle was introduced within a coagulated prone colloidal system, serving as stabilizer to resist otherwise rapid flocculation and sedimentation process. A low size asymmetry of nanoparticle/colloid serves as the new topic of investigation in addition to the well-established large size ratio nanoparticle/microparticle study. Highly charged Al2O3 nanoparticles were used within the present research context to stabilize TiO2 and Fe3O4 based colloids via the formation of composite structures. It was believed, based on the experimental evidence, that Al2O3 nanoparticle interact with the weakly charged TiO2 and Fe3O4 colloids within the binary system via absorption and/or haloing modes to increase the overall charge potential of the respective colloids, thus preventing further surface contact via van der Waal's attraction. Series of experimental results strongly suggest the presence of weakly charged colloids in the studied bimodal system where, in the absence of highly charged nanoparticle, experience rapid instability. Absorbance measurement indicated that the colloidal stability drops in accordance to the highly charged nanoparticle sedimentation rate, suggesting the dominant influence of nanoparticles to attain a well-dispersed binary system. Further, it was found that the level of colloidal stability was enhanced with increasing nanoparticle fraction within the mixture. Rheological observation revealed that each hybrid complexes demonstrated behavior reminiscence to water with negligible increase in viscosity which serves as highly favorable condition particularly in thermal transport applications. Copyright © 2015 Elsevier Inc. All rights reserved.
16. Nonlinear energy loss of highly charged heavy ions
International Nuclear Information System (INIS)
Zwicknagel, G.Guenter.
2000-01-01
For slow, highly charged heavy ions strong coupling effects in the energy transfer from the projectile-ion to an electron target plasma become important. A theoretical description of this nonlinear ion stopping has to go beyond the standard approaches like the dielectric linear response or the binary collision model which are strictly valid only at weak ion-target coupling. Here we outline an improved treatment which is based on a suitable combination of binary collision and linear response contributions. As has been verified for isotropic, nonmagnetized electron plasmas by comparison with simulations, this approach well reproduces the essential features of nonlinear stopping up to moderate coupling strength. Its extension to anisotropic, magnetized electron plasmas basically involves the fully numerical determination of the momentum and energy transfer in binary ion-electron collisions in the presence of a magnetic field. First results of such calculations are presented and discussed
17. Highly charged ions at rest: The HITRAP project at GSI
International Nuclear Information System (INIS)
Herfurth, F.; Beier, T.; Dahl, L.; Eliseev, S.; Heinz, S.; Kester, O.; Kluge, H.-J.; Kozhuharov, C.; Maero, G.; Quint, W.
2005-01-01
A decelerator will be installed at GSI in order to provide and study bare heavy nuclei or heavy nuclei with only few electrons at very low energies or even at rest. Highly-charged ions will be produced by stripping at relativistic energies. After electron cooling and deceleration in the Experimental Storage Ring the ions are ejected out of the storage ring at 4 MeV/u and further decelerated in a combination of an IH and RFQ structure. Finally, they are injected into a Penning trap where the ions are cooled to 4 K. From here, the ions can be transferred in a quasi dc or in a pulsed mode to different experimental setups. This article describes the technical concepts of this project as well as planned key experiments
18. High cumulants of conserved charges and their statistical uncertainties
Science.gov (United States)
Li-Zhu, Chen; Ye-Yin, Zhao; Xue, Pan; Zhi-Ming, Li; Yuan-Fang, Wu
2017-10-01
We study the influence of measured high cumulants of conserved charges on their associated statistical uncertainties in relativistic heavy-ion collisions. With a given number of events, the measured cumulants randomly fluctuate with an approximately normal distribution, while the estimated statistical uncertainties are found to be correlated with corresponding values of the obtained cumulants. Generally, with a given number of events, the larger the cumulants we measure, the larger the statistical uncertainties that are estimated. The error-weighted averaged cumulants are dependent on statistics. Despite this effect, however, it is found that the three sigma rule of thumb is still applicable when the statistics are above one million. Supported by NSFC (11405088, 11521064, 11647093), Major State Basic Research Development Program of China (2014CB845402) and Ministry of Science and Technology (MoST) (2016YFE0104800)
19. X-ray radiography with highly charged ions
Science.gov (United States)
Marrs, Roscoe E.
2000-01-01
An extremely small (1-250 micron FWHM) beam of slow highly charged ions deexciting on an x-ray production target generates x-ray monochromatic radiation that is passed through a specimen and detected for imaging. The resolution of the x-ray radiograms is improved and such detection is achieved with relatively low dosages of radiation passing through the specimen. An apparatus containing an electron beam ion trap (and modifications thereof) equipped with a focusing column serves as a source of ions that generate radiation projected onto an image detector. Electronic and other detectors are able to detect an increased amount of radiation per pixel than achieved by previous methods and apparati.
20. Charge Exchange of Highly Charged Ne and Mg Ions with H and He
Science.gov (United States)
Lyons, D.; Cumbee, R. S.; Stancil, P. C.
2017-10-01
Cross sections for single electron capture (SEC), or charge exchange (CX), in collisions of Ne(8-10)+ and Mg(8-12)+ with H and He, are computed using an approximate multichannel Landau-Zener (MCLZ) formalism. Final-state-resolved cross sections for the principal (n), orbital angular momentum (ℓ), and where appropriate, total spin angular momentum (S) quantum numbers are explicitly computed, except for the incident bare ions Ne10+ and Mg12+. In the latter two cases, n{\\ell }-resolution is obtained from analytical ℓ-distribution functions applied to n-resolved MCLZ cross sections. In all cases, the cross sections are computed over the collision energy range 1 meV/u to 50 keV/u with LZ parameters estimated from atomic energies obtained from experiment, theory, or, in the case of high-lying Rydberg levels, estimated with a quantum defect approach. Errors in the energy differences in the adiabatic potentials at the avoided crossing distances give the largest contribution to the uncertainties in the cross sections, which are expected to increase with decreasing cross section magnitude. The energy differences are deduced here with the Olson-Salop-Tauljberg radial coupling model. Proper selection of an ℓ-distribution function for bare ion collisions introduces another level of uncertainty into the results. Comparison is made to existing experimental or theoretical results when available, but such data are absent for most considered collision systems. The n{\\ell }S-resolved SEC cross sections are used in an optically thin cascade simulation to predict X-ray spectra and line ratios that will aid in modeling the X-ray emission in environments where CX is an important mechanism. Details on a MCLZ computational package, Stueckelberg, are also provided.
1. On adiabatic pair potentials of highly charged colloid particles
Science.gov (United States)
Sogami, Ikuo S.
2018-03-01
Generalizing the Debye-Hückel formalism, we develop a new mean field theory for adiabatic pair potentials of highly charged particles in colloid dispersions. The unoccupied volume and the osmotic pressure are the key concepts to describe the chemical and thermodynamical equilibrium of the gas of small ions in the outside region of all of the colloid particles. To define the proper thermodynamic quantities, it is postulated to take an ensemble averaging with respect to the particle configurations in the integrals for their densities consisting of the electric potential satisfying a set of equations that are derived by linearizing the Poisson-Boltzmann equation. With the Fourier integral representation of the electric potential, we calculate first the internal electric energy of the system from which the Helmholtz free energy is obtained through the Legendre transformation. Then, the Gibbs free energy is calculated using both ways of the Legendre transformation with respect to the unoccupied volume and the summation of chemical potentials. The thermodynamic functions provide three types of pair potentials, all of which are inversely proportional to the fraction of the unoccupied volume. At the limit when the fraction factor reduces to unity, the Helmholtz pair potential turns exactly into the well known Derjaguin-Landau-Verwey-Overbeek repulsive potential. The Gibbs pair potential possessing a medium-range strong repulsive part and a long-range weak attractive tail can explain the Schulze-Hardy rule for coagulation in combination with the van der Waals-London potential and describes a rich variety of phenomena of phase transitions observed in the dilute dispersions of highly charged particles.
2. 2D position sensitive microstrip sensors with charge division along the strip Studies on the position measurement error
CERN Document Server
Bassignana, D; Fernandez, M; Jaramillo, R; Lozano, M; Munoz, F.J; Pellegrini, G; Quirion, D; Vila, I; Vitorero, F
2013-01-01
Position sensitivity in semiconductor detectors of ionizing radiation is usually achieved by the segmentation of the sensing diode junction in many small sensing elements read out separately as in the case of conventional microstrips and pixel detectors. Alternatively, position sensitivity can be obtained by splitting the ionization signal collected by one single electrode amongst more than one readout channel with the ratio of the collected charges depending on the position where the signal was primary generated. Following this later approach, we implemented the charge division method in a conventional microstrip detector to obtain position sensitivity along the strip. We manufactured a proofof-concept demonstrator where the conventional aluminum electrodes were replaced by slightly resistive electrodes made of strongly doped poly-crystalline silicon and being readout at both strip ends. Here, we partially summarize the laser characterization of this first proof-of-concept demonstrator with special emphasis ...
3. High ion charge states in a high-current, short-pulse, vacuum ARC ion sources
International Nuclear Information System (INIS)
Anders, A.; Brown, I.; MacGill, R.; Dickinson, M.
1996-01-01
Ions of the cathode material are formed at vacuum arc cathode spots and extracted by a grid system. The ion charge states (typically 1-4) depend on the cathode material and only little on the discharge current as long as the current is low. Here the authors report on experiments with short pulses (several μs) and high currents (several kA); this regime of operation is thus approaching a more vacuum spark-like regime. Mean ion charge states of up to 6.2 for tungsten and 3.7 for titanium have been measured, with the corresponding maximum charge states of up to 8+ and 6+, respectively. The results are discussed in terms of Saha calculations and freezing of the charge state distribution
4. High ion charge states in a high-current, short-pulse, vacuum arc ion source
International Nuclear Information System (INIS)
Anders, A.; Brown, I.; MacGill, R.; Dickinson, M.
1995-09-01
Ions of the cathode material are formed at vacuum arc cathode spots and extracted by a grid system. The ion charge states (typically 1--4) depend on the cathode material and only little on the discharge current as long as the current is low. Here the authors report on experiments with short pulses (several micros) and high currents (several kA); this regime of operation is thus approaching a more vacuum spark-like regime. Mean ion charge states of up to 6.2 for tungsten and 3.7 for titanium have been measured, with the corresponding maximum charge states of up to 8+ and 6+, respectively. The results are discussed in terms of Saha calculations and freezing of the charge state distribution
5. Angular sensitivity of modeled scientific silicon charge-coupled devices to initial electron direction
Energy Technology Data Exchange (ETDEWEB)
Plimley, Brian, E-mail: brian.plimley@gmail.com [Nuclear Engineering Department, University of California, Berkeley, CA (United States); Coffer, Amy; Zhang, Yigong [Nuclear Engineering Department, University of California, Berkeley, CA (United States); Vetter, Kai [Nuclear Engineering Department, University of California, Berkeley, CA (United States); Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA (United States)
2016-08-11
Previously, scientific silicon charge-coupled devices (CCDs) with 10.5-μm pixel pitch and a thick (650 μm), fully depleted bulk have been used to measure gamma-ray-induced fast electrons and demonstrate electron track Compton imaging. A model of the response of this CCD was also developed and benchmarked to experiment using Monte Carlo electron tracks. We now examine the trade-off in pixel pitch and electronic noise. We extend our CCD response model to different pixel pitch and readout noise per pixel, including pixel pitch of 2.5 μm, 5 μm, 10.5 μm, 20 μm, and 40 μm, and readout noise from 0 eV/pixel to 2 keV/pixel for 10.5 μm pixel pitch. The CCD images generated by this model using simulated electron tracks are processed by our trajectory reconstruction algorithm. The performance of the reconstruction algorithm defines the expected angular sensitivity as a function of electron energy, CCD pixel pitch, and readout noise per pixel. Results show that our existing pixel pitch of 10.5 μm is near optimal for our approach, because smaller pixels add little new information but are subject to greater statistical noise. In addition, we measured the readout noise per pixel for two different device temperatures in order to estimate the effect of temperature on the reconstruction algorithm performance, although the readout is not optimized for higher temperatures. The noise in our device at 240 K increases the FWHM of angular measurement error by no more than a factor of 2, from 26° to 49° FWHM for electrons between 425 keV and 480 keV. Therefore, a CCD could be used for electron-track-based imaging in a Peltier-cooled device.
6. High sensitivity MOSFET-based neutron dosimetry
International Nuclear Information System (INIS)
Fragopoulou, M.; Konstantakos, V.; Zamani, M.; Siskos, S.; Laopoulos, T.; Sarrabayrouse, G.
2010-01-01
A new dosemeter based on a metal-oxide-semiconductor field effect transistor sensitive to both neutrons and gamma radiation was manufactured at LAAS-CNRS Laboratory, Toulouse, France. In order to be used for neutron dosimetry, a thin film of lithium fluoride was deposited on the surface of the gate of the device. The characteristics of the dosemeter, such as the dependence of its response to neutron dose and dose rate, were investigated. The studied dosemeter was very sensitive to gamma rays compared to other dosemeters proposed in the literature. Its response in thermal neutrons was found to be much higher than in fast neutrons and gamma rays.
7. High-resolution x-ray scattering studies of charge ordering in highly correlated electron systems
International Nuclear Information System (INIS)
Ghazi, M.E.
2002-01-01
Many important properties of transition metal oxides such as, copper oxide high-temperature superconductivity and colossal magnetoresistance (CMR) in manganites are due to strong electron-electron interactions, and hence these systems are called highly correlated systems. These materials are characterised by the coexistence of different kinds of order, including charge, orbital, and magnetic moment. This thesis contains high-resolution X-ray scattering studies of charge ordering in such systems namely the high-T C copper oxides isostructural system, La 2-x Sr x NiO 4 with various Sr concentrations (x = 0.33 - 0.2), and the CMR manganite system, Nd 1/2 Sr 1/2 MnO 3 . It also includes a review of charge ordering in a large variety of transition metal oxides, such as ferrates, vanadates, cobaltates, nickelates, manganites, and cuprates systems, which have been reported to date in the scientific literature. Using high-resolution synchrotron X-ray scattering, it has been demonstrated that the charge stripes exist in a series of single crystals of La 2-x Sr x NiO 4 with Sr concentrations (x = 0.33 - 0.2) at low temperatures. Satellite reflections due to the charge ordering were found with the wavevector (2ε, 0, 1) below the charge ordering transition temperature, T CO , where 2ε is the amount of separation from the corresponding Bragg peak. The charge stripes are shown to be two-dimensional in nature both by measurements of their correlation lengths and by measurement of the critical exponents of the charge stripe melting transition with an anomaly at x = 0.25. The results show by decreasing the hole concentration from the x = 0.33 to 0.2, the well-correlated charge stripes change to a glassy state at x = 0.25. The electronic transition into the charge stripe phase is second-order without any corresponding structural transition. Above the second-order transition critical scattering was observed due to fluctuations into the charge stripe phase. In a single-crystal of Nd
8. Environmental Sensitivity in Children: Development of the Highly Sensitive Child Scale and Identification of Sensitivity Groups
Science.gov (United States)
Pluess, Michael; Assary, Elham; Lionetti, Francesca; Lester, Kathryn J.; Krapohl, Eva; Aron, Elaine N.; Aron, Arthur
2018-01-01
A large number of studies document that children differ in the degree they are shaped by their developmental context with some being more sensitive to environmental influences than others. Multiple theories suggest that "Environmental Sensitivity" is a common trait predicting the response to negative as well as positive exposures.…
9. High sensitivity optical measurement of skin gloss
NARCIS (Netherlands)
Ezerskaia, A.; Ras, Arno; Bloemen, Pascal; Pereira, S.F.; Urbach, Paul; Varghese, Babu
2017-01-01
We demonstrate a low-cost optical method for measuring the gloss properties with improved sensitivity in the low gloss regime, relevant for skin gloss properties. The gloss estimation method is based on, on the one hand, the slope of the intensity gradient in the transition regime between
10. STM and transport measurements of highly charged ion modified materials
International Nuclear Information System (INIS)
Pomeroy, J.M.; Grube, H.; Perrella, A.C.; Gillaspy, J.D.
2007-01-01
Careful measurements of highly charged ions (HCIs) colliding with gases and surfaces have provided glimpses of intense electronic interactions, but a comprehensive model for the interaction mechanisms, time scales, and resultant nano-features that bridges materials systems is yet to be realized. At the National Institute of Standards and Technology (NIST) electron beam ion trap (EBIT) facility, new apparatus is now connected to the HCI beamline to allow preparation of clean, atomically flat surfaces of single crystals, e.g. gold, tungsten and silicon, and deposition and patterning of thin films, e.g. high resistivity oxides, ferromagnetic metals, normal metals and superconductors. Experiments reported here focus on the electronic and morphological structure of HCI induced nano-features. Current activities are focused on using in situ scanning tunneling microscope (STM) on Au(1 1 1) and (separately) ex situ transport measurements to study electronic properties within HCI modified magnetic multilayer systems. Specifically, we are fabricating magnetic multilayers similar to magnetic tunnel junctions (MTJs) (important in advanced magnetic field sensors and superconducting Josephson junction devices) and using HCIs to adjust critical electronic properties. The electrical response of the tunnel junction to HCIs provides a novel approach to performing HCI-induced nanostructure ensemble measurements
11. Charge degree of freedom as a sensitive probe for fission mechanism
International Nuclear Information System (INIS)
Yokoyama, A.; Baba, H.; Takahashi, N.; Duh, M.C.; Saito, T.
1997-01-01
The role of the charge degree of freedom in the heavy-ion-induced fission was investigated by carrying out a systematic analysis of radiochemically observed charge distribution in the fission of 238 U with 12 C ions of the incident energy between 85 and 140 MeV, particularly in connection with the energy given to the compound system. The charge distribution was found to follow essentially identical systematics as those which govern the light-ion fission except for the extremely weak energy dependence of the most probable charge Z p . That is, values of the derivative of Z p with respect to the energy were found to be quite small, or nearly zero, in the heavy-ion fission as compared to those of the light-ion fission. According to an analysis combining the derivatives of Z p and fission neutron data, it was deduced that the excess energy given to the fused system was spent completely in the form of pre-scission neutrons and hence the number of post-scission neutrons remained constant as in the case of light-ion fission. The observed charge distribution was reproduced under the conditions that the relaxation of the charge degree of freedom be very fast and that the separation between the two potential fragments at the moment when the charge degree of freedom has been frozen is determined by using Viola's systematics on the fragment kinetic energy. (author)
12. Charge dividing mechanism on resistive electrode in position-sensitive detectors
International Nuclear Information System (INIS)
1978-10-01
A complete charge-division mechanism, including both the diffusion and the electromagnetic wave propagation on resistive electrodes, is presented. The charge injected into such a transmission line divides between the two ends according to the ratio of resistancies and independently of the value of the line resistance, of the propagation mechanism and of the distribution of inductance and capacitance along the line. The shortest charge division time is achieved for Rl = 2π (L/C) 1 / 2 , where R, L, C are resistance, inductance and capacitance per unit length and l is the length of the line
13. Excitation and ionization of highly charged ions by electron impact
International Nuclear Information System (INIS)
Sampson, D.H.
1989-01-01
Two approaches for very rapid calculation of atomic data for high temperature plasma modeling have been developed. The first uses hydrogenic basis states and has been developed and applied in many papers discussed in previous progress reports. Hence, it is only briefly discussed here. The second is a very rapid, yet accurate, fully relativistic approach that has been developed over the past two or three years. It is described in more detail. Recently it has been applied to large scale production of atomic data. Specifically, it has been used to calculate relativistic distorted wave collision strengths and oscillator strengths for the following: all transitions from the ground level to the n=3 and 4 excited levels in the 71 Neon-like ions with nuclear charge number Z in the range 22 ≤ Z ≤ 92; all transitions among the 2s 1/2 , 2p 1/2 and 2p 3/2 levels and from them to all nlj levels with n=3,4 and 5 in the 85 Li-like ions with 8 ≤ Z ≤ 92; all transitions among the 3s 1/2 , 3p 3/2 , 3d 3/2 and 3d 5/2 levels and from them to all nlj levels with n=4 and 5 in the 71 Na-like ions with 22 ≤ Z ≤ 92; and all transitions among 4s 1/2 , 4p 1/2 , 4p 3/2 , 4d 3/2 , 4d 5/2 , 4f 5/2 and 4f 7/2 levels and from them to all nlj levels with n=5 in the 33 Cu-like ions with 60 ≤ Z ≤ 92. Also the program has been extended to give cross-sections for excitation to specific magnetic sublevels of the target ion by an electron beam and very recently it has been extended to give relativistic distorted wave cross sections for ionization of highly charged ions by electron impact
14. High sensitivity optical measurement of skin gloss
OpenAIRE
Ezerskaia, Anna; Ras, Arno; Bloemen, Pascal; Pereira, Silvania F.; Urbach, H. Paul; Varghese, Babu
2017-01-01
We demonstrate a low-cost optical method for measuring the gloss properties with improved sensitivity in the low gloss regime, relevant for skin gloss properties. The gloss estimation method is based on, on the one hand, the slope of the intensity gradient in the transition regime between specular and diffuse reflection and on the other on the sum over the intensities of pixels above threshold, derived from a camera image obtained using unpolarized white light illumination. We demonstrate the...
15. Charge Spreading and Position Sensitivity in a Segmented Planar Germanium Detector (Preprint)
National Research Council Canada - National Science Library
Kroeger, R. A; Gehrels, N; Johnson, W. N; Kurfess, J. D; Phlips, B. P; Tueller, J
1998-01-01
The size of the charge cloud collected in a segmented germanium detector is limited by the size of the initial cloud, uniformity of the electric field, and the diffusion of electrons and holes through the detector...
16. Composite space charge density functions for the calculation of gamma sensitivity of self-powered neutron detectors, using Warren's model
Science.gov (United States)
Mahant, A. K.; Rao, P. S.; Misra, S. C.
1994-07-01
In the calculational model developed by Warren and Shah for the computation of the gamma sensitivity ( Sγ) it has been observed that the computed Sγ value is quite sensitive to the space charge distribution function assumed for the insulator region and the energy of the gamma photons. The Sγ of SPNDs with Pt, Co and V emitters (manufactured by Thermocoax, France) has been measured at 60Co photon energy and a good correlation between the measured and computed values has been obtained using a composite space charge density function (CSCD), the details of which are presented in this paper. The arguments are extended for evaluating the Sγ values of several SPNDs for which Warren and Shah reported the measured values for a prompt fission gamma spectrum obtained in a swimming pool reactor. These results are also discussed.
17. Equilibrium charge state distributions of high energy heavy ions
International Nuclear Information System (INIS)
Clark, R.B.; Grant, I.S.; King, R.; Eastham, D.A.; Joy, T.
1976-01-01
Equilibrium charge state fractions have been measured for N, O, Ne, S, Ar and Kr ions at 1.04 MeV/nucleon after passing through various stripping materials. Further data were obtained at higher energy for S ions (4.12 MeV/nucleon) and Ar ions (4.12 and 9.6 MeV/nucleon). The mean charge fractions can be fitted to universal curves for both solid and gaseous strippers. Measurements of the equilibrium fraction of krypton ions at 1.04 MeV/nucleon passing through heavy vapours have shown that a higher average charge state is obtained than for lighter gaseous strippers. (Auth.)
18. Two-photon processes in highly charged ions
International Nuclear Information System (INIS)
Jahrsetz, Thorsten
2015-01-01
Two-photon processes are atomic processes in which an atom interacts simultaneously with two photons. Such processes describe a wide range of phenomena, such as two-photon decay and elastic or inelastic scattering of photons. In recent years two-photon processes involving highly charged heavy ions have become an active area of research. Such studies do not only consider the total transition or scattering rates but also their angular and polarization dependence. To support such examinations in this thesis I present a theoretical framework to describe these properties in all two-photon processes with bound initial and final states and involving heavy H-like or He-like ions. I demonstrate how this framework can be used in some detailed studies of different two-photon processes. Specifically a detailed analysis of two-photon decay of H-like and He-like ions in strong external electromagnetic fields shows the importance of considering the effect of such fields for the physics of such systems. Furthermore I studied the elastic Rayleigh as well as inelastic Raman scattering by heavy H-like ions. I found a number of previously unobserved phenomena in the angular and polarization dependence of the scattering cross-sections that do not only allow to study interesting details of the electronic structure of the ion but might also be useful for the measurement of weak physical effects in such systems.
19. Quantum interference in laser spectroscopy of highly charged lithiumlike ions
Science.gov (United States)
Amaro, Pedro; Loureiro, Ulisses; Safari, Laleh; Fratini, Filippo; Indelicato, Paul; Stöhlker, Thomas; Santos, José Paulo
2018-02-01
We investigate the quantum interference induced shifts between energetically close states in highly charged ions, with the energy structure being observed by laser spectroscopy. In this work, we focus on hyperfine states of lithiumlike heavy-Z isotopes and quantify how much quantum interference changes the observed transition frequencies. The process of photon excitation and subsequent photon decay for the transition 2 s →2 p →2 s is implemented with fully relativistic and full-multipole frameworks, which are relevant for such relativistic atomic systems. We consider the isotopes 79+207Pb and 80+209Bi due to experimental interest, as well as other examples of isotopes with lower Z , namely 56+141Pr and 64+165Ho. We conclude that quantum interference can induce shifts up to 11% of the linewidth in the measurable resonances of the considered isotopes, if interference between resonances is neglected. The inclusion of relativity decreases the cross section by 35%, mainly due to the complete retardation form of the electric dipole multipole. However, the contribution of the next higher multipoles (e.g., magnetic quadrupole) to the cross section is negligible. This makes the contribution of relativity and higher-order multipoles to the quantum interference induced shifts a minor effect, even for heavy-Z elements.
20. Two-photon processes in highly charged ions
Energy Technology Data Exchange (ETDEWEB)
Jahrsetz, Thorsten
2015-03-05
Two-photon processes are atomic processes in which an atom interacts simultaneously with two photons. Such processes describe a wide range of phenomena, such as two-photon decay and elastic or inelastic scattering of photons. In recent years two-photon processes involving highly charged heavy ions have become an active area of research. Such studies do not only consider the total transition or scattering rates but also their angular and polarization dependence. To support such examinations in this thesis I present a theoretical framework to describe these properties in all two-photon processes with bound initial and final states and involving heavy H-like or He-like ions. I demonstrate how this framework can be used in some detailed studies of different two-photon processes. Specifically a detailed analysis of two-photon decay of H-like and He-like ions in strong external electromagnetic fields shows the importance of considering the effect of such fields for the physics of such systems. Furthermore I studied the elastic Rayleigh as well as inelastic Raman scattering by heavy H-like ions. I found a number of previously unobserved phenomena in the angular and polarization dependence of the scattering cross-sections that do not only allow to study interesting details of the electronic structure of the ion but might also be useful for the measurement of weak physical effects in such systems.
1. High energy particle detectors utilizing cryogenic charge storage
Energy Technology Data Exchange (ETDEWEB)
Coon, D; Engels, E Jr; Plants, D; Shepard, P F; Yang, Y [Pittsburgh Univ., PA (USA); Sopira, M; Papania, R [Westinghouse Research and Development Labs., Monroeville, PA (USA)
1984-09-15
The mechanism of cryogenic charge storage as a method of particle detection is reviewed. A description of a simple multielement strip detector operated in this mode is given, and partial results on its operating characteristics presented.
2. High sensitivity optical measurement of skin gloss.
Science.gov (United States)
Ezerskaia, Anna; Ras, Arno; Bloemen, Pascal; Pereira, Silvania F; Urbach, H Paul; Varghese, Babu
2017-09-01
We demonstrate a low-cost optical method for measuring the gloss properties with improved sensitivity in the low gloss regime, relevant for skin gloss properties. The gloss estimation method is based on, on the one hand, the slope of the intensity gradient in the transition regime between specular and diffuse reflection and on the other on the sum over the intensities of pixels above threshold, derived from a camera image obtained using unpolarized white light illumination. We demonstrate the improved sensitivity of the two proposed methods using Monte Carlo simulations and experiments performed on ISO gloss calibration standards with an optical prototype. The performance and linearity of the method was compared with different professional gloss measurement devices based on the ratio of specular to diffuse intensity. We demonstrate the feasibility for in-vivo skin gloss measurements by quantifying the temporal evolution of skin gloss after application of standard paraffin cream bases on skin. The presented method opens new possibilities in the fields of cosmetology and dermatopharmacology for measuring the skin gloss and resorption kinetics and the pharmacodynamics of various external agents.
3. The interactions of high-energy, highly charged Xe ions with buckyballs
International Nuclear Information System (INIS)
Ali, R.; Berry, H.G.; Cheng, S.
1994-01-01
Ionization and fragmentation have been measured for C 60 molecules bombarded by highly charged (up to 35+) xenon ions with energies ranging up to 625 MeV. The observed mass distribution of positively charged fragments is explained in terms of a theoretical model indicating that the total interaction cross section contains roughly equal contributions from (a) excitation of the giant plasmon resonance, and (b) large-energy-transfer processes that lead to multiple fragmentation of the molecule. Preliminary results of measurements on VUV photons emitted in these interactions are also presented
4. The study towards high intensity high charge state laser ion sources.
Science.gov (United States)
Zhao, H Y; Jin, Q Y; Sha, S; Zhang, J J; Li, Z M; Liu, W; Sun, L T; Zhang, X Z; Zhao, H W
2014-02-01
As one of the candidate ion sources for a planned project, the High Intensity heavy-ion Accelerator Facility, a laser ion source has been being intensively studied at the Institute of Modern Physics in the past two years. The charge state distributions of ions produced by irradiating a pulsed 3 J/8 ns Nd:YAG laser on solid targets of a wide range of elements (C, Al, Ti, Ni, Ag, Ta, and Pb) were measured with an electrostatic ion analyzer spectrometer, which indicates that highly charged ions could be generated from low-to-medium mass elements with the present laser system, while the charge state distributions for high mass elements were relatively low. The shot-to-shot stability of ion pulses was monitored with a Faraday cup for carbon target. The fluctuations within ±2.5% for the peak current and total charge and ±6% for pulse duration were demonstrated with the present setup of the laser ion source, the suppression of which is still possible.
5. The selectively bred high alcohol sensitivity (HAS) and low alcohol sensitivity (LAS) rats differ in sensitivity to nicotine.
Science.gov (United States)
de Fiebre, NancyEllen C; Dawson, Ralph; de Fiebre, Christopher M
2002-06-01
Studies in rodents selectively bred to differ in alcohol sensitivity have suggested that nicotine and ethanol sensitivities may cosegregate during selective breeding. This suggests that ethanol and nicotine sensitivities may in part be genetically correlated. Male and female high alcohol sensitivity (HAS), control alcohol sensitivity, and low alcohol sensitivity (LAS) rats were tested for nicotine-induced alterations in locomotor activity, body temperature, and seizure activity. Plasma and brain levels of nicotine and its primary metabolite, cotinine, were measured in these animals, as was the binding of [3H]cytisine, [3H]epibatidine, and [125I]alpha-bungarotoxin in eight brain regions. Both replicate HAS lines were more sensitive to nicotine-induced locomotor activity depression than the replicate LAS lines. No consistent HAS/LAS differences were seen on other measures of nicotine sensitivity; however, females were more susceptible to nicotine-induced seizures than males. No HAS/LAS differences in nicotine or cotinine levels were seen, nor were differences seen in the binding of nicotinic ligands. Females had higher levels of plasma cotinine and brain nicotine than males but had lower brain cotinine levels than males. Sensitivity to a specific action of nicotine cosegregates during selective breeding for differential sensitivity to a specific action of ethanol. The differential sensitivity of the HAS/LAS rats is due to differences in central nervous system sensitivity and not to pharmacokinetic differences. The differential central nervous system sensitivity cannot be explained by differences in the numbers of nicotinic receptors labeled in ligand-binding experiments. The apparent genetic correlation between ethanol and nicotine sensitivities suggests that common genes modulate, in part, the actions of both ethanol and nicotine and may explain the frequent coabuse of these agents.
6. Multiple Coulomb scattering of high-energy heavy charged particle beams used in biology and medicine
International Nuclear Information System (INIS)
Wong, M.; Schimmerling, W.; Ludewigt, B.; Phillips, M.; Curtis, S.; Tobias, C.A.
1987-01-01
The authors measured lateral displacement and angular distributions of high-energy heavy charged particles emerging from a target at the Lawrence Berkeley Laboratory BEVALAC with beams used in radiobiology experiments. Multiple Coulomb scattering occurring in the target material generally spreads the beam laterally and increases its divergence. The apparatus consists of four sets of position-sensitive semiconductor detectors located along the beam line. Each providing two position signals and one energy signal. The difference between the two position signals is used to determine the particle position in one dimension. The two position signals are constrained to add up to the energy deposition signal in order to reject multiple-particle traversals. The vector directions for the incident and emerging particles are reconstructed in three dimensions from their measured coordinated positions. Lateral and angular distributions are reported for beams of high-energy neon, iron and uranium ions incident on targets of aluminum, cooper, lead and water
7. Performance of high-resolution position-sensitive detectors developed for storage-ring decay experiments
International Nuclear Information System (INIS)
Yamaguchi, T.; Suzaki, F.; Izumikawa, T.; Miyazawa, S.; Morimoto, K.; Suzuki, T.; Tokanai, F.; Furuki, H.; Ichihashi, N.; Ichikawa, C.; Kitagawa, A.; Kuboki, T.; Momota, S.; Nagae, D.; Nagashima, M.; Nakamura, Y.; Nishikiori, R.; Niwa, T.; Ohtsubo, T.; Ozawa, A.
2013-01-01
Highlights: • Position-sensitive detectors were developed for storage-ring decay spectroscopy. • Fiber scintillation and silicon strip detectors were tested with heavy ion beams. • A new fiber scintillation detector showed an excellent position resolution. • Position and energy detection by silicon strip detectors enable full identification. -- Abstract: As next generation spectroscopic tools, heavy-ion cooler storage rings will be a unique application of highly charged RI beam experiments. Decay spectroscopy of highly charged rare isotopes provides us important information relevant to the stellar conditions, such as for the s- and r-process nucleosynthesis. In-ring decay products of highly charged RI will be momentum-analyzed and reach a position-sensitive detector set-up located outside of the storage orbit. To realize such in-ring decay experiments, we have developed and tested two types of high-resolution position-sensitive detectors: silicon strips and scintillating fibers. The beam test experiments resulted in excellent position resolutions for both detectors, which will be available for future storage-ring experiments
8. Bunch arrival time monitors; Concepts towards improving the sensitivity for low charge operation for FLASH II and XFEL
Energy Technology Data Exchange (ETDEWEB)
Penirschke, Andreas; Angelovski, Aleksandar; Jakoby, Rolf [TU Darmstadt, Institut fuer Mikrowellentechnik und Photonik, Merckstr. 25, 64283 Darmstadt (Germany); Sydlo, Cezary; Bousonville, Michael; Czwalinna, Marie Kristin; Schlarb, Holger [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Kuhl, Alexander [University of Hamburg, Physics Department, Accelerator Physics Group (Germany); Weiland, Thomas [Technische Univ. Darmstadt (Germany). Inst. fuer Theorie Elektromagnetischer Felder
2013-07-01
High gain Free-Electron Lasers can generate ultra short X-ray pulses in the femtosecond range. For a stable operation of the FEL, the precise knowledge of the bunch arrival time is crucial. A novel high bandwidth Bunch Arrival time Monitor was recently installed at FLASH to allow a low charge operation mode with a sub-10 fs resolution for bunch charges of 20 pC or more. The BAM is equipped with cone shaped pickups for the precise measurement of both, the high and low bunch charge operation mode. For the extension of FLASH facility to FLASH II new pickups for the high bandwidth BAMs need to be developed. The new BAM needs to maximize the voltage level of the beam induced signal for low charge operation mode in order to provide sufficient signal strength for the subsequent electronics. In this talk, we present concepts to improve the signal strength at the electro-optic modulators for low charge operation at FLASH II and XFEL.
9. New approach to 3-D, high sensitivity, high mass resolution space plasma composition measurements
International Nuclear Information System (INIS)
McComas, D.J.; Nordholt, J.E.
1990-01-01
This paper describes a new type of 3-D space plasma composition analyzer. The design combines high sensitivity, high mass resolution measurements with somewhat lower mass resolution but even higher sensitivity measurements in a single compact and robust design. While the lower resolution plasma measurements are achieved using conventional straight-through time-of-flight mass spectrometry, the high mass resolution measurements are made by timing ions reflected in a linear electric field (LEF), where the restoring force that an ion experiences is proportional to the depth it travels into the LEF region. Consequently, the ion's equation of motion in that dimension is that of a simple harmonic oscillator and its travel time is simply proportional to the square root of the ion's mass/charge (m/q). While in an ideal LEF, the m/q resolution can be arbitrarily high, in a real device the resolution is limited by the field linearity which can be achieved. In this paper we describe how a nearly linear field can be produced and discuss how the design can be optimized for various different plasma regimes and spacecraft configurations
10. The character of resonant charge exchange involving highly excited atoms
International Nuclear Information System (INIS)
Kosarim, A. V.; Smirnov, B. M.; Capitelli, M.; Laricchiuta, A.
2012-01-01
We study the process of resonant charge exchange involving excited helium atoms with the principal quantum number n = 5 colliding with the helium ion in the ground state in the collision energy range from thermal up to 10 eV. This information may be important for the analysis of planet atmospheres containing helium, in particular, for Jupiter’s atmosphere, but our basic interest is the transition from the quantum to classical description of this process, where, due to large cross sections, evaluations of the cross sections are possible. For the chosen process, quantum theory allows determining the cross section as a result of a tunnel electron transition, while classical theory accounts for over-barrier electron transitions. The classical theory additionally requires effective transitions between states with close energies. The analysis of these transitions for helium with n = 5 shows that electron momenta and their projections are mixed for a part of the states, while for other states, the mixing is absent. A simple criterion to separate such states is given. In addition, the main contribution to the cross section of resonant charge exchange follows from tunnel electron transitions. As a result, the quantum theory is better for calculating the cross sections of resonant charge exchange than the classical one and also allows finding the partial cross sections of resonant charge exchange, while the classical approach gives the cross section of resonant charge exchange in a simple manner with the accuracy of 20%.
11. A modified space charge routine for high intensity bunched beams
International Nuclear Information System (INIS)
Lapostolle, P.; Lombardi, A.M.; Tanke, E.; Valero, S.; Garnett, R.W.; Wangler, T.P.
1996-01-01
A new routine and a computer code (DYNAC) for the calculation of space charge densities in a new generation of linear accelerators for various industrial applications is presented. The new beam dynamics method used in this code, employs a set of quasi-Liouvillian equations, allowing beam dynamics computations in long and complex structures for electrons, as well as protons and ions. With this new beam dynamics method, the coordinates of particles are known at any position in the accelerating elements, allowing multistep space charge calculations. (K.A.)
12. High-Sensitivity GaN Microchemical Sensors
Science.gov (United States)
Son, Kyung-ah; Yang, Baohua; Liao, Anna; Moon, Jeongsun; Prokopuk, Nicholas
2009-01-01
Systematic studies have been performed on the sensitivity of GaN HEMT (high electron mobility transistor) sensors using various gate electrode designs and operational parameters. The results here show that a higher sensitivity can be achieved with a larger W/L ratio (W = gate width, L = gate length) at a given D (D = source-drain distance), and multi-finger gate electrodes offer a higher sensitivity than a one-finger gate electrode. In terms of operating conditions, sensor sensitivity is strongly dependent on transconductance of the sensor. The highest sensitivity can be achieved at the gate voltage where the slope of the transconductance curve is the largest. This work provides critical information about how the gate electrode of a GaN HEMT, which has been identified as the most sensitive among GaN microsensors, needs to be designed, and what operation parameters should be used for high sensitivity detection.
13. Beamline for low-energy transport of highly charged ions at HITRAP
International Nuclear Information System (INIS)
Andelkovic, Z.; Herfurth, F.; Kotovskiy, N.; König, K.; Maaß, B.; Murböck, T.; Neidherr, D.; Schmidt, S.; Steinmann, J.; Vogel, M.; Vorobjev, G.
2015-01-01
A beamline for transport of highly charged ions with energies as low as a few keV/charge has been constructed and commissioned at GSI. Complementary to the existing infrastructure of the HITRAP facility for deceleration of highly charged ions from the GSI accelerator, the new beamline connects the HITRAP ion decelerator and an EBIT with the associated experimental setups. Therefore, the facility can now transport the decelerated heavy highly charged ions to the experiments or supply them offline with medium-heavy highly charged ions from the EBIT, both at energies as low as a few keV/charge. Here we present the design of the 20 m long beamline with the corresponding beam instrumentation, as well as its performance in terms of energy and transport efficiency
14. Development of a highly sensitive lithium fluoride thermoluminescence dosimeter
International Nuclear Information System (INIS)
Moraes da Silva, Teresinha de; Campos, Leticia Lucente
1995-01-01
In recent times, LiF: Mg, Cu, P thermoluminescent phosphor has been increasingly in use for radiation monitoring due its high sensitivity and ease of preparation. The Dosimetric Materials Production Laboratory of IPEN, (Nuclear Energy Institute) has developed a simple method to obtain high sensitivity LiF. The preparation method is described. (author). 4 refs., 1 fig., 1 tab
15. High-precision high-sensitivity clock recovery circuit for a mobile payment application
International Nuclear Information System (INIS)
Sun Lichong; Yan Na; Min Hao; Ren Wenliang
2011-01-01
This paper presents a fully integrated carrier clock recovery circuit for a mobile payment application. The architecture is based on a sampling-detection module and a charge pump phase locked loop. Compared with clock recovery in conventional 13.56 MHz transponders, this circuit can recover a high-precision consecutive carrier clock from the on/off keying (OOK) signal sent by interrogators. Fabricated by a SMIC 0.18-μm EEPROM CMOS process, this chip works from a single power supply as low as 1.5 V Measurement results show that this circuit provides 0.34% frequency deviation and 8 mV sensitivity. (semiconductor integrated circuits)
16. High-LET dose-response characteristics by track structure theory of heavy charged particles
International Nuclear Information System (INIS)
Hansen, J.W.; Olsen, K.J.
1981-09-01
The track structure theory developed by Katz and co-workers ascribes the effect of high-LET radiation to the highly inhomogeneous dose distribution due to low energy Δ-rays ejected from the particle track. The theory predicts the effectiveness of high-LET radiation by using the ion parameters zsub(eff') effective charge of the ion, and β = v/c, the relative ion velocity, together with the characteristic dose D 37 derived from low-LET dose-response characteristic of the detector and the approximate size asub(0) of the sensitive element of the detector. 60 Co gamma-irradiation is used as a reference low-LET radiation, while high-LET radiation ranging from 16 MeV protons to 4 MeV/amu 16 0-ions covering an initial LET range of 30-5500 MeVcm 2 /g is obtained from a tandem Van de Graaff accelerator. A thin film (5mg/cm 2 ) radiochromic dye cyanide plastic dosemeter was used as detector with the characteristic dose of 16.8 Mrad and a sensitive element size of 10 -7 cm. Theoretical and experimental effectiveness, RBE, agreed within 10 to 25% depending on LET. (author)
17. Simulation study of signal formation in position sensitive planar p-on-n silicon detectors after short range charge injection
International Nuclear Information System (INIS)
Peltola, T.; Eremin, V.; Verbitskaya, E.; Härkönen, J.
2017-01-01
Segmented silicon detectors (micropixel and microstrip) are the main type of detectors used in the inner trackers of Large Hadron Collider (LHC) experiments at CERN. Due to the high luminosity and eventual high fluence of energetic particles, detectors with fast response to fit the short shaping time of 20–25 ns and sufficient radiation hardness are required. Charge collection measurements carried out at the Ioffe Institute have shown a reversal of the pulse polarity in the detector response to short-range charge injection. Since the measured negative signal is about 30–60% of the peak positive signal, the effect strongly reduces the CCE even in non-irradiated detectors. For further investigation of the phenomenon the measurements have been reproduced by TCAD simulations. As for the measurements, the simulation study was applied for the p-on-n strip detectors similar in geometry to those developed for the ATLAS experiment and for the Ioffe Institute designed p-on-n strip detectors with each strip having a window in the metallization covering the p + implant, allowing the generation of electron-hole pairs under the strip implant. Red laser scans across the strips and the interstrip gap with varying laser diameters and Si-SiO 2 interface charge densities ( Q f ) were carried out. The results verify the experimentally observed negative response along the scan in the interstrip gap. When the laser spot is positioned on the strip p + implant the negative response vanishes and the collected charge at the active strip increases respectively. The simulation results offer a further insight and understanding of the influence of the oxide charge density in the signal formation. The main result of the study is that a threshold value of Q f , that enables negligible losses of collected charges, is defined. The observed effects and details of the detector response for different charge injection positions are discussed in the context of Ramo's theorem.
18. Simulation study of signal formation in position sensitive planar p-on-n silicon detectors after short range charge injection
Science.gov (United States)
Peltola, T.; Eremin, V.; Verbitskaya, E.; Härkönen, J.
2017-09-01
Segmented silicon detectors (micropixel and microstrip) are the main type of detectors used in the inner trackers of Large Hadron Collider (LHC) experiments at CERN. Due to the high luminosity and eventual high fluence of energetic particles, detectors with fast response to fit the short shaping time of 20-25 ns and sufficient radiation hardness are required. Charge collection measurements carried out at the Ioffe Institute have shown a reversal of the pulse polarity in the detector response to short-range charge injection. Since the measured negative signal is about 30-60% of the peak positive signal, the effect strongly reduces the CCE even in non-irradiated detectors. For further investigation of the phenomenon the measurements have been reproduced by TCAD simulations. As for the measurements, the simulation study was applied for the p-on-n strip detectors similar in geometry to those developed for the ATLAS experiment and for the Ioffe Institute designed p-on-n strip detectors with each strip having a window in the metallization covering the p+ implant, allowing the generation of electron-hole pairs under the strip implant. Red laser scans across the strips and the interstrip gap with varying laser diameters and Si-SiO2 interface charge densities (Qf) were carried out. The results verify the experimentally observed negative response along the scan in the interstrip gap. When the laser spot is positioned on the strip p+ implant the negative response vanishes and the collected charge at the active strip increases respectively. The simulation results offer a further insight and understanding of the influence of the oxide charge density in the signal formation. The main result of the study is that a threshold value of Qf, that enables negligible losses of collected charges, is defined. The observed effects and details of the detector response for different charge injection positions are discussed in the context of Ramo's theorem.
19. Triggers for a high sensitivity charm experiment
International Nuclear Information System (INIS)
Christian, D.C.
1994-07-01
Any future charm experiment clearly should implement an E T trigger and a μ trigger. In order to reach the 10 8 reconstructed charm level for hadronic final states, a high quality vertex trigger will almost certainly also be necessary. The best hope for the development of an offline quality vertex trigger lies in further development of the ideas of data-driven processing pioneered by the Nevis/U. Mass. group
20. Precisely Controlled Ultrathin Conjugated Polymer Films for Large Area Transparent Transistors and Highly Sensitive Chemical Sensors.
Science.gov (United States)
Khim, Dongyoon; Ryu, Gi-Seong; Park, Won-Tae; Kim, Hyunchul; Lee, Myungwon; Noh, Yong-Young
2016-04-13
A uniform ultrathin polymer film is deposited over a large area with molecularlevel precision by the simple wire-wound bar-coating method. The bar-coated ultrathin films not only exhibit high transparency of up to 90% in the visible wavelength range but also high charge carrier mobility with a high degree of percolation through the uniformly covered polymer nanofibrils. They are capable of realizing highly sensitive multigas sensors and represent the first successful report of ethylene detection using a sensor based on organic field-effect transistors. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
1. Charging of Dust Grains in a Nuclear-Induced Plasma at High Pressures
International Nuclear Information System (INIS)
Pal’, A. F.; Starostin, A. N.; Filippov, A. V.
2001-01-01
The process of dust-grain charging in plasmas produced by radioactive decay products or spontaneous fission fragments in air and xenon at high pressures is studied numerically in the hydrodynamic approximation. It is shown that, at sufficiently high rates of gas ionization, the dust grains in air are charged by electrons rather than ions, so that the grain charge in air is comparable to that in electropositive gases. The results of numerical calculations based on a complete model agree well with the experimental data. The time evolution of the grain charge is investigated, and the characteristic time scales on which the grains acquire an electric charge are established. The validity of approximate theories of dust-grain charging in electropositive and electronegative gases at high pressures is examined
2. The interactions of high-energy, highly-charged ions with fullerenes
International Nuclear Information System (INIS)
Ali, R.; Berry, H.G.; Cheng, S.
1996-01-01
In 1985, Robert Curl and Richard Smalley discovered a new form of carbon, the fullerene, C 60 , which consists of 60 carbon atoms in a closed cage resembling a soccer ball. In 1990, Kritschmer et al. were able to make macroscopic quantities of fullerenes. This has generated intense activity to study the properties of fullerenes. One area of research involves collisions between fullerenes and atoms, ions or electrons. In this paper we describe experiments involving interactions between fullerenes and highly charged ions in which the center-of-mass energies exceed those used in other work by several orders of magnitude. The high values of projectile velocity and charge state result in excitation and decay processes differing significantly from those seen in studies 3 at lower energies. Our results are discussed in terms of theoretical models analogous to those used in nuclear physics and this provides an interesting demonstration of the unity of physics
3. Measurements of the Properties of Highly-charged high-Z ions
International Nuclear Information System (INIS)
Augustine J. Smith, Ph.D.
2007-01-01
We had proposed carrying out a systematic experimental investigation of the atomic physics of highly charged, high-Z ions, produced in the Lawrence Livermore National Laboratory LLNL electron beam ion trap (EBIT-I) in its high energy mode, superEBIT. In particular we were going to accurately measure line positions for Δn=0 transitions in few electron high-Z ions; this was meant to enable us to investigate relativistic and quantum electrodynamics QED contributions to the energy levels as well as the nuclear properties of heavy ions. We were also going to measure cross sections for various electron-ion interactions, the degree of polarization of emitted x-rays, and radiation cooling rates of various ionization stages of highly charged, high-Z ions. This would enable us to study fundamental atomic physics of high-Z ions at relativistic electron impact energies and in the intense nuclear fields of highly ionized, high-Z ions. This would extend previous measurements we have carried out to a regime where there is a paucity of good data. These measurements were expected to generate increased theoretical interest and activity in this area. The project will extend a very successful collaboration between Morehouse College (MC) and a national laboratory LLNL, Minority student training and development are major components of the proposal
4. QED in highly-charged high Z ions - experiments at the storage ring ESR
International Nuclear Information System (INIS)
Mokler, P.H.
1996-01-01
A survey on the fundamental structure aspects of very heavy few -electron ions, in particular H-like systems, is presented. Special emphasis is given to contribution from quantum-electro-dynamics at strong central potentials. The technical possibilities to produce highly-charged heavy ions are reviewed and the ground-state Lamb-shift experiments performed at the heavy ion storage ring ESR are summarized. A short outlook on further developments in this field is added. (author). 23 refs, 9 figs
5. Analysis of charge transport in gels containing polyoxometallates using methods of different sensitivity to migration.
Science.gov (United States)
Caban, Karolina; Lewera, Adam; Zukowska, Grazyna Z; Kulesza, Pawel J; Stojek, Zbigniew; Jeffrey, Kenneth R
2006-08-04
Two methods have been used for examination of transport of charge in gels soaked with DMF and containing dissolved polyoxometallates. The first method is based on the analysis of both Cottrellian and steady-state currents and therefore is capable of giving the concentration of the electroactive redox centres and their transport (diffusion-type) coefficient. The second method provides the real diffusion coefficients, i.e. transport coefficients free of migrational influence, for both the substrate and the product of the electrode reaction. Several gels based on poly(methyl methacrylate), with charged (addition of 1-acrylamido-2-methyl-2-propanesulphonic acid to the polymerization mixture) and uncharged chains, have been used in the investigation. The ratio obtained for the diffusion coefficient (second method) and transport coefficient (first method) was smaller for the gels containing charged polymer chains than for the gels with uncharged chains. In part these changes could be explained by the contribution of migration to the transport of polyoxomatallates in the gels. However, the impact of the changes in the polymer-channel capacity at the electrode surface while the electrode process proceeds was also considered. These structural changes should affect differently the methods based on different time domains.
6. Techno-economic and sensitivity analysis for grid-connected renewable energy electric boat charging station in Terengganu
Directory of Open Access Journals (Sweden)
Salleh N. A. S.
2017-01-01
Full Text Available In order to encourage the eco-friendly technologies in transportation sector, the reliance on fuel need to be reduced and the use of renewable energy (RE technology as energy source are widely explored by researchers. Thus, this study focus on the feasibility of developing grid-connected renewable energy electric boat charging station for the fishermen in Terengganu using simulation-based method by HOMER software. Five year solar radiation and wind speed data were collected at Universiti Sultan Zainal Abidin (UNISZA weather station. For load profile, the information about fishing activities and the amount of subsidy spent by the government were obtained from the interview session with the fishermen and validated with Lembaga Kemajuan Ikan Malaysia (LKIM. The results acquired are compared between grid-only and grid-connected RE systems in term of net present cost (NPC, operational cost and payback period. A sensitivity analysis is done to find the minimal Feed-in Tariff (FiT rate that can be implemented in order to encourage the use of RE system in this sector. Then, the relationship between FiT and NPC, payback period and emission of pollutants are analyzed. At current FiT rates RM 0.813/kWh, hybrid grid-PV system manages to achieve its optimal in generating high income from selling the power to the grid with convincing amount of electricity production and short payback period. It is concluded at minimum RM 0.56/kWh of FiT, the grid-connected RE system is possible to be developed because its performance shows better outcome compared to the grid-only system.
7. High-precision X-ray spectroscopy of highly-charged ions at the experimental storage ring using silicon microcalorimeters
Science.gov (United States)
Scholz, Pascal A.; Andrianov, Victor; Echler, Artur; Egelhof, Peter; Kilbourne, Caroline; Kiselev, Oleg; Kraft-Bermuth, Saskia; McCammon, Dan
2017-10-01
X-ray spectroscopy on highly charged heavy ions provides a sensitive test of quantum electrodynamics in very strong Coulomb fields. One limitation of the current accuracy of such experiments is the energy resolution of available X-ray detectors for energies up to 100 keV. To improve this accuracy, a novel detector concept, namely the concept of microcalorimeters, is exploited for this kind of measurements. The microcalorimeters used in the present experiments consist of silicon thermometers, ensuring a high dynamic range, and of absorbers made of high-Z material to provide high X-ray absorption efficiency. Recently, besides an earlier used detector, a new compact detector design, housed in a new dry cryostat equipped with a pulse tube cooler, was applied at a test beamtime at the experimental storage ring (ESR) of the GSI facility in Darmstadt. A U89+ beam at 75 MeV/u and a 124Xe54+ beam at various beam energies, both interacting with an internal gas-jet target, were used in different cycles. This test was an important benchmark for designing a larger array with an improved lateral sensitivity and statistical accuracy.
8. Rendering high charge density of states in ionic liquid-gated MoS 2 transistors
NARCIS (Netherlands)
Lee, Y.; Lee, J.; Kim, S.; Park, H.S.
2014-01-01
We investigated high charge density of states (DOS) in the bandgap of MoS2 nanosheets with variable temperature measurements on ionic liquid-gated MoS2 transistors. The thermally activated charge transport indicates that the electrical current in the two-dimensional MoS 2 nanosheets under high
9. Ionization of highly charged iodine ions near the Bohr velocity
International Nuclear Information System (INIS)
Zhou, Xianming; Cheng, Rui; Lei, Yu; Sun, Yuanbo; Ren, Jieru; Liu, Shidong; Deng, Jiachuan; Zhao, Yongtao; Xiao, Guoqing
2015-01-01
We have measured the L-shell X-rays of iodine from the collisions of 3 MeV I q+(q=15,20,22,25,26) ions with an iron target. It is found that the X-ray yield decreases with the increasing initial charge state. The energy of the subshell X-ray has a blue shift, which is independent of the projectile charge state. In addition, the relative intensity ratios of Lβ 1,3,4 and Lβ 2,15 to Lα 1,2 X-ray are obtained and compared with the theoretical calculations. That they are larger than for a singly ionized atom can be understood by the multiple ionization effect of the outer-shell electrons
10. Peltier effect in multilayered nanopillars under high density charge current
International Nuclear Information System (INIS)
Gravier, L; Fukushima, A; Kubota, H; Yamamoto, A; Yuasa, S
2006-01-01
From the basic equations of thermoelectricity, we model the thermal regimes that develop in multilayered nanopillar elements experiencing continuous charge currents. The energy conservation principle was applied to all layer-layer and layer-electrode junctions. The obtained set of equations was solved to derive the temperature of each junction. The contribution of the Peltier effect is included in an effective resistance. This model gives satisfactory fits to experimental data obtained on a series of reference nanopillar elements
11. Superconductivity and charge transfer excitations in high Tc superconductors
International Nuclear Information System (INIS)
Balseiro, C.A.; Alascio, B.; Gagliano, E.; Rojo, A.
1988-01-01
We present some numerical results to show that in a simple model which includes Cu 3d and O 2p orbitals together with inter and intra atomic correlations pairing between holes can occur due to charge transfer excitations. We present also a simple approximation to derive an effective Hamiltonian containing an interaction between particles which is attractive for some values of the different microscopic parameters
12. High density thermite mixture for shaped charge ordnance disposal
OpenAIRE
Tamer Elshenawy; Salah Soliman; Ahmed Hawass
2017-01-01
The effect of thermite mixture based on aluminum and ferric oxides for ammunition neutralization has been studied and tested. Thermochemical calculations have been carried out for different percentage of Al using Chemical Equilibrium Code to expect the highest performance thermite mixture used for shaped charge ordnance disposal. Densities and enthalpy of different formulations have been calculated and demonstrated. The optimized thermite formulation has been prepared experimentally using col...
13. Charge identification of highly ionizing particles in desensitized nuclear emulsion using high speed read-out system
International Nuclear Information System (INIS)
Toshito, T.; Kodama, K.; Yusa, K.; Ozaki, M.; Amako, K.; Kameoka, S.; Murakami, K.; Sasaki, T.; Aoki, S.; Ban, T.; Fukuda, T.; Naganawa, N.; Nakamura, T.; Natsume, M.; Niwa, K.; Takahashi, S.; Kanazawa, M.; Kanematsu, N.; Komori, M.; Sato, S.; Asai, M.; Koi, T.; Fukushima, C.; Ogawa, S.; Shibasaki, M.; Shibuya, H.
2006-01-01
We performed an experimental study of charge identification of heavy ions from helium to carbon having energy of about 290MeV/u using an emulsion chamber. Emulsion was desensitized by means of forced fading (refreshing) to expand a dynamic range of response to highly charged particles. For the track reconstruction and charge identification, the fully automated high speed emulsion read-out system, which was originally developed for identifying minimum ionizing particles, was used without any modification. Clear track by track charge identification up to Z=6 was demonstrated. The refreshing technique has proved to be a powerful technique to expand response of emulsion film to highly ionizing particles
14. Low Power and High Sensitivity MOSFET-Based Pressure Sensor
International Nuclear Information System (INIS)
Zhang Zhao-Hua; Ren Tian-Ling; Zhang Yan-Hong; Han Rui-Rui; Liu Li-Tian
2012-01-01
Based on the metal-oxide-semiconductor field effect transistor (MOSFET) stress sensitive phenomenon, a low power MOSFET pressure sensor is proposed. Compared with the traditional piezoresistive pressure sensor, the present pressure sensor displays high performances on sensitivity and power consumption. The sensitivity of the MOSFET sensor is raised by 87%, meanwhile the power consumption is decreased by 20%. (cross-disciplinary physics and related areas of science and technology)
15. Model dependence of isospin sensitive observables at high densities
Energy Technology Data Exchange (ETDEWEB)
Guo, Wen-Mei [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); School of Science, Huzhou Teachers College, Huzhou 313000 (China); Yong, Gao-Chan, E-mail: yonggaochan@impcas.ac.cn [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190 (China); Wang, Yongjia [School of Science, Huzhou Teachers College, Huzhou 313000 (China); School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000 (China); Li, Qingfeng [School of Science, Huzhou Teachers College, Huzhou 313000 (China); Zhang, Hongfei [School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000 (China); State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190 (China); Zuo, Wei [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190 (China)
2013-10-07
Within two different frameworks of isospin-dependent transport model, i.e., Boltzmann–Uehling–Uhlenbeck (IBUU04) and Ultrarelativistic Quantum Molecular Dynamics (UrQMD) transport models, sensitive probes of nuclear symmetry energy are simulated and compared. It is shown that neutron to proton ratio of free nucleons, π{sup −}/π{sup +} ratio as well as isospin-sensitive transverse and elliptic flows given by the two transport models with their “best settings”, all have obvious differences. Discrepancy of numerical value of isospin-sensitive n/p ratio of free nucleon from the two models mainly originates from different symmetry potentials used and discrepancies of numerical value of charged π{sup −}/π{sup +} ratio and isospin-sensitive flows mainly originate from different isospin-dependent nucleon–nucleon cross sections. These demonstrations call for more detailed studies on the model inputs (i.e., the density- and momentum-dependent symmetry potential and the isospin-dependent nucleon–nucleon cross section in medium) of isospin-dependent transport model used. The studies of model dependence of isospin sensitive observables can help nuclear physicists to pin down the density dependence of nuclear symmetry energy through comparison between experiments and theoretical simulations scientifically.
16. Preparation of cold Mg+ion clouds for sympathetic cooling of highly charged ions at SPECTRAP
International Nuclear Information System (INIS)
2012-02-01
The bound electrons in hydrogen-like or lithium-like heavy ions experience extremely strong electric and magnetic fields in the surrounding of the nucleus. Laser spectroscopy of the ground-state hyperfine splitting in the lead region provides a sensitive tool to test strong-field quantum electro dynamics (QED), especially in the magnetic sector. Previous measurements on hydrogen-like systems performed in an electron-beam ion trap (EBIT) or at the experimental storage ring (ESR) were experimentally limited in accuracy due to statistics, the large Doppler broadening and the ion energy. The full potential of the QED test can only be exploited if measurements for hydrogen- and lithium-like ions are performed with accuracy improved by 2-3 orders of magnitude. Therefore, the new Penning trap setup SPECTRAP - dedicated for laser spectroscopy on trapped and cooled highly charged ions - is currently commissioned at GSI Darmstadt. Heavy highly charged ions will be delivered to this trap by the HITRAP facility in the future. SPECTRAP is a cylindrical Penning trap with axial access for external ion injection and radial optical access mounted inside a cold-bore superconducting Helmholtz-type split-coil magnet. To reach the targeted accuracy in laser spectroscopy, an efficient and fast cooling process for the highly charged ions must be employed. This can be realized by sympathetic cooling with a cloud of laser-cooled light ions. Within this thesis work, a laser system and an ion source for the production of such a 24 Mg + ion cloud was developed and commissioned at SPECTRAP. An all-solid-state laser system for the generation of 279.6 nm light was designed and built. It consists of a fiber laser at 1118.5 nm followed by frequency quadrupling using two successive second-harmonic generation stages with actively stabilized ring resonators and nonlinear crystals. The laser system can deliver more than 15 mW of UV laser power under optimal conditions and requires little maintenance
17. Development and a Validation of a Charge Sensitive Organic Rankine Cycle (ORC Simulation Tool
Directory of Open Access Journals (Sweden)
Davide Ziviani
2016-05-01
Full Text Available Despite the increasing interest in organic Rankine cycle (ORC systems and the large number of cycle models proposed in the literature, charge-based ORC models are still almost absent. In this paper, a detailed overall ORC simulation model is presented based on two solution strategies: condenser subcooling and total working fluid charge of the system. The latter allows the subcooling level to be predicted rather than specified as an input. The overall cycle model is composed of independent models for pump, expander, line sets, liquid receiver and heat exchangers. Empirical and semi-empirical models are adopted for the pump and expander, respectively. A generalized steady-state moving boundary method is used to model the heat exchangers. The line sets and liquid receiver are used to better estimate the total charge of the system and pressure drops. Finally, the individual components are connected to form a cycle model in an object-oriented fashion. The solution algorithm includes a preconditioner to guess reasonable values for the evaporating and condensing temperatures and a main cycle solver loop which drives to zero a set of residuals to ensure the convergence of the solution. The model has been developed in the Python programming language. A thorough validation is then carried out against experimental data obtained from two test setups having different nominal size, working fluids and individual components: (i a regenerative ORC with a 5 kW scroll expander and an oil flooding loop; (ii a regenerative ORC with a 11 kW single-screw expander. The computer code is made available through open-source dissemination.
18. KATANA – A charge-sensitive triggering system for the SπRIT experiment
Energy Technology Data Exchange (ETDEWEB)
Lasko, P. [Institute of Nuclear Physics, Polish Academy of Sciences,Kraków (Poland); Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University,Kraków (Poland); Adamczyk, M.; Brzychczyk, J. [Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University,Kraków (Poland); Hirnyk, P.; Łukasik, J. [Institute of Nuclear Physics, Polish Academy of Sciences,Kraków (Poland); Pawłowski, P., E-mail: piotr.pawlowski@ifj.edu.pl [Institute of Nuclear Physics, Polish Academy of Sciences,Kraków (Poland); Pelczar, K. [Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University,Kraków (Poland); Snoch, A. [University of Wroclaw, Wrocław (Poland); Sochocka, A.; Sosin, Z. [Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University,Kraków (Poland); Barney, J. [Department of Physics and Astronomy, Michigan State University, East Lansing (United States); National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing (United States); Cerizza, G. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing (United States); Estee, J. [Department of Physics and Astronomy, Michigan State University, East Lansing (United States); National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing (United States); Isobe, T. [RIKEN Nishina Center, Wako, Saitama (Japan); Jhang, G. [Department of Physics, Korea University, Seoul (Korea, Republic of); Kaneko, M. [Department of Physics, Kyoto University, Kita-shirakawa, Kyoto (Japan); Kurata-Nishimura, M. [RIKEN Nishina Center, Wako, Saitama (Japan); and others
2017-06-01
KATANA - the Krakow Array for Triggering with Amplitude discrimiNAtion - has been built and used as a trigger and veto detector for the SπRIT TPC at RIKEN. Its construction allows operating in magnetic field and providing fast response for ionizing particles, giving an approximate forward multiplicity and charge information. Depending on this information, trigger and veto signals are generated. The article presents performance of the detector and details of its construction. A simple phenomenological parametrization of the number of emitted scintillation photons in plastic scintillator is proposed. The effect of the light output deterioration in the plastic scintillator due to the in-beam irradiation is discussed.
19. High-Efficiency Dye-Sensitized Solar Cell with Three-Dimensional Photoanode
KAUST Repository
Tétreault, Nicolas
2011-11-09
Herein, we present a straightforward bottom-up synthesis of a high electron mobility and highly light scattering macroporous photoanode for dye-sensitized solar cells. The dense three-dimensional Al/ZnO, SnO2, or TiO 2 host integrates a conformal passivation thin film to reduce recombination and a large surface-area mesoporous anatase guest for high dye loading. This novel photoanode is designed to improve the charge extraction resulting in higher fill factor and photovoltage for DSCs. An increase in photovoltage of up to 110 mV over state-of-the-art DSC is demonstrated. © 2011 American Chemical Society.
20. High-Efficiency Dye-Sensitized Solar Cell with Three-Dimensional Photoanode
KAUST Repository
Té treault, Nicolas; Arsenault, É ric; Heiniger, Leo-Philipp; Soheilnia, Navid; Brillet, Jé ré mie; Moehl, Thomas; Zakeeruddin, Shaik; Ozin, Geoffrey A.; Grä tzel, Michael
2011-01-01
Herein, we present a straightforward bottom-up synthesis of a high electron mobility and highly light scattering macroporous photoanode for dye-sensitized solar cells. The dense three-dimensional Al/ZnO, SnO2, or TiO 2 host integrates a conformal passivation thin film to reduce recombination and a large surface-area mesoporous anatase guest for high dye loading. This novel photoanode is designed to improve the charge extraction resulting in higher fill factor and photovoltage for DSCs. An increase in photovoltage of up to 110 mV over state-of-the-art DSC is demonstrated. © 2011 American Chemical Society.
1. Highly efficient and stable cyclometalated ruthenium(II) complexes as sensitizers for dye-sensitized solar cells
International Nuclear Information System (INIS)
Huang, Jian-Feng; Liu, Jun-Min; Su, Pei-Yang; Chen, Yi-Fan; Shen, Yong; Xiao, Li-Min; Kuang, Dai-Bin; Su, Cheng-Yong
2015-01-01
Highlights: • Four novel thiocyanate-free cyclometalated ruthenium sensitizer were conveniently synthesized. • The D-CF 3 -sensitized DSSCs show higher efficiency compared to N719 based cells. • The DSSCs based on D-CF 3 and D-bisCF 3 sensitizers exhibit excellent long-term stability. • The diverse cyclometalated Ru complexes can be developed as high-performance sensitizers for use in DSSC. - Abstract: Four novel thiocyanate-free cyclometallted Ru(II) complexes, D-bisCF 3 , D-CF 3 , D-OMe, and D-DPA, with two 4,4′-dicarboxylic acid-2,2′-bipyridine together with a functionalized phenylpyridine ancillary ligand, have been designed and synthesized. The effect of different substituents (R = bisCF 3 , CF 3 , OMe, and DPA) on the ancillary C^N ligand on the photophysical properties and photovoltaic performance is investigated. Under standard global AM 1.5 solar conditions, the device based on D-CF 3 sensitizer gives a higher conversion efficiency of 8.74% than those based on D-bisCF 3 , D-OMe, and D-DPA, which can be ascribed to its broad range of visible light absorption, appropriate localization of the frontier orbitals, weak hydrogen bonds between -CF 3 and -OH groups at the TiO 2 surface, moderate dye loading on TiO 2 , and high charge collection efficiency. Moreover, the D-bisCF 3 and D-CF 3 based DSSCs exhibit good stability under 100 mW cm −2 light soaking at 60 °C for 400 h
2. Iodide Ion Pairing with Highly Charged Ruthenium Polypyridyl Cations in CH3CN.
Science.gov (United States)
Swords, Wesley B; Li, Guocan; Meyer, Gerald J
2015-05-04
A series of three highly charged cationic ruthenium(II) polypyridyl complexes of the general formula [Ru(deeb)3-x(tmam)x](PF6)2x+2, where deeb is 4,4'-diethyl ester-2,2'-bipyridine and tmam is 4,4'-bis[(trimethylamino)methyl]-2,2'-bipyridine, were synthesized and characterized and are referred to as 1, 2, or 3 based on the number of tmam ligands. Crystals suitable for X-ray crystallography were obtained for the homoleptic complex 3, which was found to possess D3 symmetry over the entire ruthenium complex. The complexes displayed visible absorption spectra typical of metal-to-ligand charge-transfer (MLCT) transitions. In acetonitrile, quasi-reversible waves were assigned to Ru(III/II) electron transfer, with formal reduction potentials that shifted negative as the number of tmam ligands was increased. Room temperature photoluminescence was observed in acetonitrile with quantum yields of ϕ ∼ 0.1 and lifetimes of τ ∼ 2 μs. The spectroscopic and electrochemical data were most consistent with excited-state localization on the deeb ligand for 1 and 2 and on the tmam ligand for 3. The addition of tetrabutylammonium iodide to the complexes dissolved in a CH3CN solution led to changes in the UV-vis absorption spectra consistent with ion pairing. A Benesi-Hildebrand-type analysis of these data revealed equilibrium constants that increased with the cationic charge 1 10(8) s(-1). The possible relevance of this work to solar energy conversion and dye-sensitized solar cells is discussed.
3. Dynamics of Interfacial Charge Transfer States and Carriers Separation in Dye-Sensitized Solar Cells: A Time-Resolved Terahertz Spectroscopy Study
OpenAIRE
Brauer, Jan C.; Marchioro, Arianna; Paraecattil, Arun A.; Oskouei, Ahmad A.; Moser, Jacques-E.
2015-01-01
Electron injection from a photoexcited molecular sensitizer into a wide-bandgap semiconductor is the primary step toward charge separation in dye-sensitized solar cells (DSSCs). According to the current understanding of DSSCs functioning mechanism, charges are separated directly during this primary electron transfer process, yielding hot conduction band electrons in the semiconductor and positive holes localized on oxidized dye molecules at the surface. Comparing results of ultrafast transien...
4. Generation of initial kinetic distributions for simulation of long-pulse charged particle beams with high space-charge intensity
Directory of Open Access Journals (Sweden)
Steven M. Lund
2009-11-01
Full Text Available Self-consistent Vlasov-Poisson simulations of beams with high space-charge intensity often require specification of initial phase-space distributions that reflect properties of a beam that is well adapted to the transport channel—both in terms of low-order rms (envelope properties as well as the higher-order phase-space structure. Here, we first review broad classes of kinetic distributions commonly in use as initial Vlasov distributions in simulations of unbunched or weakly bunched beams with intense space-charge fields including the following: the Kapchinskij-Vladimirskij (KV equilibrium, continuous-focusing equilibria with specific detailed examples, and various nonequilibrium distributions, such as the semi-Gaussian distribution and distributions formed from specified functions of linear-field Courant-Snyder invariants. Important practical details necessary to specify these distributions in terms of standard accelerator inputs are presented in a unified format. Building on this presentation, a new class of approximate initial kinetic distributions are constructed using transformations that preserve linear focusing, single-particle Courant-Snyder invariants to map initial continuous-focusing equilibrium distributions to a form more appropriate for noncontinuous focusing channels. Self-consistent particle-in-cell simulations are employed to show that the approximate initial distributions generated in this manner are better adapted to the focusing channels for beams with high space-charge intensity. This improved capability enables simulations that more precisely probe intrinsic stability properties and machine performance.
5. Detection of non-absorbing charge dynamics via refractive index change in dye-sensitized solar cells.
Science.gov (United States)
Kuwahara, Shota; Hata, Hiroaki; Taya, Soichiro; Maeda, Naotaka; Shen, Qing; Toyoda, Taro; Katayama, Kenji
2013-04-28
The carrier dynamics in dye-sensitized solar cells was investigated by using the transient grating, in addition to the transient absorption method and transient photocurrent method on the order of microseconds to seconds. The signals for the same sample were obtained under a short-circuit condition to compare the carrier dynamics via refractive index change with the transient photocurrent measurement. Optically silent carrier dynamics by transient absorption have been successfully observed via a refractive index change. The corresponding signal components were originated from the charge dynamics at the solid/liquid interface, especially on the liquid side; rearrangement or diffusion motion of charged redox species occurred when the injected electrons were trapped at the TiO2 surface and when the electron-electrolyte recombination occurred at the interface. The assignments were confirmed from the dependence on the viscosity of the solvent and the presence of 4-tert-butyl pyridine. As the viscosity of the solvent increased, the rearrangement and the motion of the charged redox species were delayed. Since the rearrangement dynamics was changed by the presence of 4-tert-butyl pyridine, it affected not only the TiO2 surface but also the redox species close to the interface.
6. High Charge State Ions Extracted from Metal Plasmas in the Transition Regime from Vacuum Spark to High Current Vacuum Arc
International Nuclear Information System (INIS)
Yushkov, Georgy Yu.; Anders, A.
2008-01-01
Metal ions were extracted from pulsed discharge plasmas operating in the transition region between vacuum spark (transient high voltage of kV) and vacuum arc (arc voltage ∼ 20 V). At a peak current of about 4 kA, and with a pulse duration of 8 (micro)s, we observed mean ion charges states of about 6 for several cathode materials. In the case of platinum, the highest average charge state was 6.74 with ions of charge states as high as 10 present. For gold we found traces of charge state 11, with the highest average charge state of 7.25. At currents higher than 5 kA, non-metallic contaminations started to dominate the ion beam, preventing further enhancement of the metal charge states
7. Investigation of the energy loss and the charge state of high energy heavy ions in a hydrogen plasma
International Nuclear Information System (INIS)
Dietrich, K.G.
1991-07-01
For heavy ions with energy of 1.4 to 5.9 MeV/u the energy loss and charge state after transmission through a totally ionized hydrogen plasma are investigated. Plasma target was a Z-pinch device incorporated in the beam optics of the accelerator by a pumping system. In the 20 cm long pinch hydrogen plasmas with densities up to 1.5x10 19 cm -3 and temperatures above 5 eV are produced, with ionization efficiency higher than 99%. The ions pass the plasma on the symmetry axis of the plasma column through small apertures in the electrodes. The energy loss was measured by time-of-flight method, the plasma density by interferometry along the pinch axis. For the first time the ion charge after transmission through the plasma has been determined by a charge spectrometer being a combination of a dipole magnet and a position sensitive detector with high time resolution. A growth of the average charge of heavy ions in plasma higher than the equilibrium charge in cold gas was discovered, caused by a reduction of electron capture by fast heavy ions in ionized matter. The electron loss rates in plasma and cold gas are equal. (orig./AH) [de
8. Production of Highly Charged Pharmaceutical Aerosols Using a New Aerosol Induction Charger.
Science.gov (United States)
Golshahi, Laleh; Longest, P Worth; Holbrook, Landon; Snead, Jessica; Hindle, Michael
2015-09-01
Properly charged particles can be used for effective lung targeting of pharmaceutical aerosols. The objective of this study was to characterize the performance of a new induction charger that operates with a mesh nebulizer for the production of highly charged submicrometer aerosols to bypass the mouth-throat and deliver clinically relevant doses of medications to the lungs. Variables of interest included combinations of model drug (albuterol sulfate) and charging excipient (NaCl) as well as strength of the charging field (1-5 kV/cm). Aerosol charge and size were measured using a modified electrical low pressure impactor system combined with high performance liquid chromatography. At the approximate mass median aerodynamic diameter (MMAD) of the aerosol (~0.4 μm), the induction charge on the particles was an order of magnitude above the field and diffusion charge limit. The nebulization rate was 439.3 ± 42.9 μl/min, which with a 0.1% w/v solution delivered 419.5 ± 34.2 μg of medication per minute. A new correlation was developed to predict particle charge produced by the induction charger. The combination of the aerosol induction charger and predictive correlations will allow for the practical generation and control of charged submicrometer aerosols for targeting deposition within the lungs.
9. Understanding sensitization behavior of lead selenide photoconductive detectors by charge separation model
International Nuclear Information System (INIS)
Zhao, Lihua; Qiu, Jijun; Weng, Binbin; Chang, Caleb; Yuan, Zijian; Shi, Zhisheng
2014-01-01
We introduce a charge separation model in this work to explain the mechanism of enhanced photoconductivity of polycrystalline lead salt photoconductors. Our results show that this model could clarify the heuristic fabrication processes of such lead salt detectors that were not well understood and often considered mysterious for nearly a century. The improved lifetime and performance of the device, e.g., responsivity, are attributed to the spatial separation of holes and electrons, hence less possibility of carrier recombination. This model shows that in addition to crystal quality the size of crystallites, the depth of outer conversion layer, and doping concentration could all affect detector performance. The simulation results agree well with experimental results and thus offer a very useful tool for further improvement of lead salt detectors. The model was developed with lead salt family of photoconductors in mind, but may well be applicable to a wider class of semiconducting films
10. Charge transport in poly(p-phenylene vinylene) at low temperature and high electric field
NARCIS (Netherlands)
Katsouras, I.; Najafi, A.; Asadi, K.; Kronemeijer, A. J.; Oostra, A. J.; Koster, L. J. A.; de Leeuw, D. M.; Blom, P. W. M.
Charge transport in poly(2-methoxy, 5-(2'-ethyl-hexyloxy)-p-phenylene vinylene) (MEH-PPV)-based hole-only diodes is investigated at high electric fields and low temperatures using a novel diode architecture. Charge carrier densities that are in the range of those in a field-effect transistor are
11. Ion sources development at GANIL for radioactive beams and high charge state ions
International Nuclear Information System (INIS)
Leroy, R.; Barue, C.; Canet, C.; Dupuis, M.; Flambard, J.L.; Gaubert, G.; Gibouin, S.; Huguet, Y.; Jardin, P.; Lecesne, N.; Leherissier, P.; Lemagnen, F.; Pacquet, J.Y.; Pellemoine-Landre, F.; Rataud, J.P.; Saint-Laurent, M.G.; Villari, A.C.C.; Maunoury, L.
2001-01-01
The GANIL laboratory has in charge the production of ion beams for nuclear and non nuclear physics. This article reviews the last developments that are underway in the fields of radioactive ion beam production, increase of the metallic ion intensities and production of highly charges ion beams. (authors)
12. Solar photovoltaic charging of high voltage nickel metal hydride batteries using DC power conversion
Science.gov (United States)
Kelly, Nelson A.; Gibson, Thomas L.
There are an increasing number of vehicle choices available that utilize batteries and electric motors to reduce tailpipe emissions and increase fuel economy. The eventual production of electricity and hydrogen in a renewable fashion, such as using solar energy, can achieve the long-term vision of having no tailpipe environmental impact, as well as eliminating the dependence of the transportation sector on dwindling supplies of petroleum for its energy. In this report we will demonstrate the solar-powered charging of the high-voltage nickel-metal hydride (NiMH) battery used in the GM 2-mode hybrid system. In previous studies we have used low-voltage solar modules to produce hydrogen via the electrolysis of water and to directly charge lithium-ion battery modules. Our strategy in the present work was to boost low-voltage PV voltage to over 300 V using DC-DC converters in order to charge the high-voltage NiMH battery, and to regulate the battery charging using software to program the electronic control unit supplied with the battery pack. A protocol for high-voltage battery charging was developed, and the solar to battery charging efficiency was measured under a variety of conditions. We believe this is the first time such high-voltage batteries have been charged using solar energy in order to prove the concept of efficient, solar-powered charging for battery-electric vehicles.
13. High-frequency acoustic charge transport in GaAs nanowires
NARCIS (Netherlands)
Büyükköse, S.; Hernandez-Minguez, A.; Vratzov, B.; Somaschini, C.; Geelhaar, L.; Riechert, H.; van der Wiel, Wilfred Gerard; Santos, P.V.
2014-01-01
The oscillating piezoelectric fields accompanying surface acoustic waves are able to transport charge carriers in semiconductor heterostructures. Here, we demonstrate high-frequency (above 1 GHz) acoustic charge transport in GaAs-based nanowires deposited on a piezoelectric substrate. The short
14. Highly confined ions store charge more efficiently in supercapacitors
Science.gov (United States)
Merlet, C.; Péan, C.; Rotenberg, B.; Madden, P. A.; Daffos, B.; Taberna, P.-L.; Simon, P.; Salanne, M.
2013-10-01
Liquids exhibit specific properties when they are adsorbed in nanoporous structures. This is particularly true in the context of supercapacitors, for which an anomalous increase in performance has been observed for nanoporous electrodes. This enhancement has been traditionally attributed in experimental studies to the effect of confinement of the ions from the electrolyte inside sub-nanometre pores, which is accompanied by their partial desolvation. Here we perform molecular dynamics simulations of realistic supercapacitors and show that this picture is correct at the microscopic scale. We provide a detailed analysis of the various environments experienced by the ions. We pick out four different adsorption types, and we, respectively, label them as edge, planar, hollow and pocket sites upon increase of the coordination of the molecular species by carbon atoms from the electrode. We show that both the desolvation and the local charge stored on the electrode increase with the degree of confinement.
15. Calcium carbonate electronic-insulating layers improve the charge collection efficiency of tin oxide photoelectrodes in dye-sensitized solar cells
International Nuclear Information System (INIS)
Shaikh, Shoyebmohamad F.; Mane, Rajaram S.; Hwang, Yun Jeong; Joo, Oh-Shim
2015-01-01
In dye-sensitized solar cells (DSSCs), a surface passivation layer has been employed on the tin oxide (SnO 2 ) photoanodes to enhance the charge collection efficiency, and thus the power conversion efficiency. Herein, we demonstrate that the electronic-insulating layering of calcium carbonate (CaCO 3 ) can improve the charge collection efficiency in dye-sensitized solar cells designed with photoanodes. In order to evaluate the effectiveness of CaCO 3 layering, both layered and pristine SnO 2 photoanodes are characterized with regard to their structures, morphologies, and photo-electrochemical measurements. The SnO 2 -6L CaCO 3 photoanode has demonstrated as high as 3.5% power conversion efficiency; 3.5-fold greater than that of the pristine SnO 2 photoanode. The enhancement in the power conversion efficiency is corroborated with the number of the dye molecules, the passivation of surface states, a negative shift in the conduction band position, and the reduced electron recombination rate of photoelectrons following the coating of the CaCO 3 surface layer
16. Experimental characterization of the Hitrap Cooler trap with highly charged ions.
OpenAIRE
Fedotova, Svetlana
2013-01-01
The HITRAP (Highly charged Ions TRAP)facility is being set up and commissioned at GSI, Darmstadt. It will provide heavy, highly charged ions at low velocities to high-precision atomic physics experiments. Within this work the Cooler trap- the key element of the HITRAP facility was tested. The Cooler trap was assembled, aligned, and commissioned in trapping experiments with ions from off-line sources.The work performed within the scope of this thesis provided the baseline for further operation...
17. High-resolution X-ray spectra from low-temperature, highly charged ions
International Nuclear Information System (INIS)
Beiersdorfer, P.
1996-09-01
The electron beam ion traps (EBIT) at Livermore were designed for studying the x-ray emission of highly charged ions produced and excited by a monoenergetic electron beam. The precision with which the x-ray emission can be analyzed has recently been increased markedly when it became possible to decouple the temperature of the ions from the energy of the electron beam by several orders of magnitude. By adjusting the trap parameters, ion temperatures as low as 15.8±4.4 eV for Ti 20+ and 59.4±9.9 eV for Cs 45+ were achieved. These temperatures were more than two orders of magnitude lower than the energy of the multi-keV electron beam used for the production and excitation of the ions. A discussion of the techniques used to produce and study low-temperature highly charged ions is presented in this progress report. The low ion temperatures enabled measurements heretofore impossible. As an example, a direct observation of the natural line width of fast electric dipole allowed x-ray transitions is described. From the observed natural line width and b making use of the time-energy relations of the uncertainty principle we were able to determine a radiative transition rate of 1.65 fs for the 2p-3d resonance transition in neonlike Cs 45+ . A brief discussion of other high-precision measurements enabled by our new technique is also given
18. A high-sensitivity neutron counter and waste-drum counting with the high-sensitivity neutron instrument
International Nuclear Information System (INIS)
Hankins, D.E.; Thorngate, J.H.
1993-04-01
At Lawrence Livermore National Laboratory (LLNL), a highly sensitive neutron counter was developed that can detect and accurately measure the neutrons from small quantities of plutonium or from other low-level neutron sources. This neutron counter was originally designed to survey waste containers leaving the Plutonium Facility. However, it has proven to be useful in other research applications requiring a high-sensitivity neutron instrument
19. On the nature of high field charge transport in reinforced silicone dielectrics: Experiment and simulation
Energy Technology Data Exchange (ETDEWEB)
Huang, Yanhui, E-mail: huangy12@rpi.edu; Schadler, Linda S. [Department of Material Science and Engineering, Rensselaer Polytechnic Institute, 110 8th street, Troy, New York 12180 (United States)
2016-08-07
The high field charge injection and transport properties in reinforced silicone dielectrics were investigated by measuring the time-dependent space charge distribution and the current under dc conditions up to the breakdown field and were compared with the properties of other dielectric polymers. It is argued that the energy and spatial distribution of localized electronic states are crucial in determining these properties for polymer dielectrics. Tunneling to localized states likely dominates the charge injection process. A transient transport regime arises due to the relaxation of charge carriers into deep traps at the energy band tails and is successfully verified by a Monte Carlo simulation using the multiple-hopping model. The charge carrier mobility is found to be highly heterogeneous due to the non-uniform trapping. The slow moving electron packet exhibits a negative field dependent drift velocity possibly due to the spatial disorder of traps.
20. HyperCP: A high-rate spectrometer for the study of charged hyperon and kaon decays
International Nuclear Information System (INIS)
Burnstein, R.A.; Chakravorty, A.; Chan, A.; Chen, Y.C.; Choong, W.-S.; Clark, K.; Dukes, E.C.; Durandet, C.; Felix, J.; Fuzesy, R.; Gidal, G.; Gu, P.; Gustafson, H.R.; Ho, C.; Holmstrom, T.; Huang, M.; James, C.; Jenkins, C.M.; Jones, T.D.; Kaplan, D.M.; Lederman, L.M.; Leros, N.; Longo, M.J.; Lopez, F.; Lu, L.C.; Luebke, W.; Luk, K.-B.; Nelson, K.S.; Park, H.K.; Perroud, J.-P.; Rajaram, D.; Rubin, H.A.; Teng, P.K.; Turko, B.; Volk, J.; White, C.G.; White, S.L.; Zyla, P.
2005-01-01
The HyperCP experiment (Fermilab E871) was designed to search for rare phenomena in the decays of charged strange particles, in particular CP violation in Ξ and Λ hyperon decays with a sensitivity of 10 -4 . Intense charged secondary beams were produced by 800GeV/c protons and momentum selected by a magnetic channel. Decay products were detected in a large-acceptance, high-rate magnetic spectrometer using multiwire proportional chambers, trigger hodoscopes, a hadronic calorimeter, and a muon-detection system. Nearly identical acceptances and efficiencies for hyperons and antihyperons decaying within an evacuated volume were achieved by reversing the polarities of the channel and spectrometer magnets. A high-rate data-acquisition system enabled 231 billion events to be recorded in 12 months of data-taking
1. A high charge state heavy ion beam source for heavy ion fusion
International Nuclear Information System (INIS)
Eylon, S.; Henestroza, E.
1996-01-01
A high current, low emittance, high charge state heavy ion beam source is being developed. This is designed to deliver a heavy ion fusion (HIF) driver accelerator scale beam. Using a high charge state beam in a driver accelerator for HIF may increase the acceleration efficiency, leading to a reduction in the driver accelerator size and cost. The proposed source system, which consists of a gas beam electron stripper followed by a high charge state beam separator, can be added to existing single charge state, low emittance, high brightness ion sources and injectors. We shall report on the source physics design using 3D beam simulations and experimental feasibility study results using a neutral gas stripper and a beam separator at the exit of the LBL 2 MV injector. (orig.)
2. A high-performance channel engineered charge-plasma-based MOSFET with high-κ spacer
Science.gov (United States)
Shan, Chan; Wang, Ying; Luo, Xin; Bao, Meng-tian; Yu, Cheng-hao; Cao, Fei
2017-12-01
In this paper, the performance of graded channel double-gate MOSFET (GC-DGFET) that utilizes the charge-plasma concept and a high-κ spacer is investigated through 2-D device simulations. The results demonstrate that GC-DGFET with high-κ spacer can effectively improve the ON-state driving current (ION) and reduce the OFF-leakage current (IOFF). We find that reduction of the initial energy barrier between the source and channel is the origin of this ION enhancement. The reason for the IOFF reduction is identified to be the extension of the effective channel length owing to the fringing field via high-κ spacers. Consequently, these devices offer enhanced performance by reducing the total gate-to-gate capacitance (Cgg) and decreasing the intrinsic delay (τ).
3. Core/shell colloidal quantum dot exciplex states for the development of highly efficient quantum-dot-sensitized solar cells.
Science.gov (United States)
Wang, Jin; Mora-Seró, Iván; Pan, Zhenxiao; Zhao, Ke; Zhang, Hua; Feng, Yaoyu; Yang, Guang; Zhong, Xinhua; Bisquert, Juan
2013-10-23
Searching suitable panchromatic QD sensitizers for expanding the light-harvesting range, accelerating charge separation, and retarding charge recombination is an effective way to improve power conversion efficiency (PCE) of quantum-dot-sensitized solar cells (QDSCs). One possible way to obtain a wide absorption range is to use the exciplex state of a type-II core/shell-structured QDs. In addition, this system could also provide a fast charge separation and low charge-recombination rate. Herein, we report on using a CdTe/CdSe type-II core/shell QD sensitizer with an absorption range extending into the infrared region because of its exciplex state, which is covalently linked to TiO2 mesoporous electrodes by dropping a bifunctional linker molecule mercaptopropionic acid (MPA)-capped QD aqueous solution onto the film electrode. High loading and a uniform distribution of QD sensitizer throughout the film electrode thickness have been confirmed by energy dispersive X-ray (EDX) elemental mapping. The accelerated electron injection and retarded charge-recombination pathway in the built CdTe/CdSe QD cells in comparison with reference CdSe QD-based cells have been confirmed by impedance spectroscopy, fluorescence decay, and intensity-modulated photocurrent/photovoltage spectroscopy (IMPS/IMVS) analysis. With the combination of the high QD loading and intrinsically superior optoelectronic properties of type-II core/shell QD (wide absorption range, fast charge separation, and slow charge recombination), the resulting CdTe/CdSe QD-based regenerative sandwich solar cells exhibit a record PCE of 6.76% (J(sc) = 19.59 mA cm(-2), V(oc) = 0.606 V, and FF = 0.569) with a mask around the active film under a full 1 sun illumination (simulated AM 1.5), which is the highest reported to date for liquid-junction QDSCs.
4. Transition Metal Polypyridine Complexes: Studies of Mediation in Dye-Sensitized Solar Cells and Charge Separation
Energy Technology Data Exchange (ETDEWEB)
Elliott, C. Michael [Colorado State Univ., Fort Collins, CO (United States). Dept. of Chemistry; Prieto, Amy L. [Colorado State Univ., Fort Collins, CO (United States). Dept. of Chemistry
2017-02-08
The Elliott group has long been supported by DOE for studies of cobalt(II/III) trisbypiridine (DTB) mediator complexes in dye sensitized solar cells. Previous work demonstrated that Co(II/III) chemistry is sensitive to the environment, showing unprecedented electrode-surface and electrolyte dependant voltammetry. In electrolytes that have large lipophilic cations, voltammetry of the [Co(DTB)3]2+/3+ couple is nearly Nernstian in appearance on nominally oxide-free metal surfaces. In contrast, on semiconductor electrodes in electrolytes with small, hard cations such as Li+, the electron transfer rates are so slow that it is difficult to measure any Faradaic current even at overpotentials of ±1 V. These studies are of direct relevance to the operation of cobalt-based mediators in solar cells. The research has also shown that these mediators are compatible with copper phenantroline based dyes, in contrast to I- due to the insolubility of CuI.
5. Liouville master equation for multielectron dynamics: Neutralization of highly charged ions near a LiF surface
International Nuclear Information System (INIS)
Wirtz, Ludger; Reinhold, Carlos O.; Lemell, Christoph; Burgdoerfer, Joachim
2003-01-01
We present a simulation of the neutralization of highly charged ions in front of a lithium fluoride surface including the close-collision regime above the surface. The present approach employs a Monte Carlo solution of the Liouville master equation for the joint probability density of the ionic motion and the electronic population of the projectile and the target surface. It includes single as well as double particle-hole (de)excitation processes and incorporates electron correlation effects through the conditional dynamics of population strings. The input in terms of elementary one- and two-electron transfer rates is determined from classical trajectory Monte Carlo calculations as well as quantum-mechanical Auger calculations. For slow projectiles and normal incidence, the ionic motion depends sensitively on the interplay between image acceleration towards the surface and repulsion by an ensemble of positive hole charges in the surface ('trampoline effect'). For Ne 10+ we find that image acceleration is dominant and no collective backscattering high above the surface takes place. For grazing incidence, our simulation delineates the pathways to complete neutralization. In accordance with recent experimental observations, most ions are reflected as neutral or even as singly charged negative particles, irrespective of the charge state of the incoming ions
6. HIAF: New opportunities for atomic physics with highly charged heavy ions
Science.gov (United States)
Ma, X.; Wen, W. Q.; Zhang, S. F.; Yu, D. Y.; Cheng, R.; Yang, J.; Huang, Z. K.; Wang, H. B.; Zhu, X. L.; Cai, X.; Zhao, Y. T.; Mao, L. J.; Yang, J. C.; Zhou, X. H.; Xu, H. S.; Yuan, Y. J.; Xia, J. W.; Zhao, H. W.; Xiao, G. Q.; Zhan, W. L.
2017-10-01
A new project, High Intensity heavy ion Accelerator Facility (HIAF), is currently being under design and construction in China. HIAF will provide beams of stable and unstable heavy ions with high energies, high intensities and high quality. An overview of new opportunities for atomic physics using highly charged ions and radioactive heavy ions at HIAF is given.
7. High Temperature Thermosetting Polyimide Nanocomposites Prepared with Reduced Charge Organoclay
Science.gov (United States)
Campbell, Sandi; Liang, Margaret I.
2005-01-01
The naturally occurring sodium and calcium cations found in bentonite clay galleries were exchanged with lithium cations. Following the cation exchange, a series of reduced charge clays were prepared by heat treatment of the lithium bentonite at 130 C, 150 C, or 170 C. Inductively coupled plasma (ICP) analysis showed that heating the lithium clay at elevated temperatures reduced its cation exchange capacity. Ion exchange of heat-treated clays with either a protonated alkyl amine or a protonated aromatic diamine resulted in decreasing amounts of the organic modifier incorporated into the lithium clay. The level of silicate dispersion in a thermosetting polyimide matrix was dependent upon the temperature of Li-clay heat treatment as well as the organic modification. In general, clays treated at 150 C or 170 C, and exchanged with protonated octadcylamine or protonated 2,2'-dimethlybenzidine (DMBZ) showed a higher degree of dispersion than clays treated at 130 C, or exchanged with protonated dodecylamine. Dynamic mechanical analysis showed little change in the storage modulus or T(sub g) of the nanocomposites compared to the base resin. However, long term isothermal aging of the samples showed a significant decrease in the resin oxidative weight loss. Nanocomposite samples aged in air for 1000 hours at 288 C showed of to a decrease in weight loss compared to that of the base resin. This again was dependent on the temperature at which the Li-clay was heated and the choice of organic modification.
8. Achieving sensitive, high-resolution laser spectroscopy at CRIS
Energy Technology Data Exchange (ETDEWEB)
Groote, R. P. de [Instituut voor Kern- en Stralingsfysica, KU Leuven (Belgium); Lynch, K. M., E-mail: kara.marie.lynch@cern.ch [EP Department, CERN, ISOLDE (Switzerland); Wilkins, S. G. [The University of Manchester, School of Physics and Astronomy (United Kingdom); Collaboration: the CRIS collaboration
2017-11-15
The Collinear Resonance Ionization Spectroscopy (CRIS) experiment, located at the ISOLDE facility, has recently performed high-resolution laser spectroscopy, with linewidths down to 20 MHz. In this article, we present the modifications to the beam line and the newly-installed laser systems that have made sensitive, high-resolution measurements possible. Highlights of recent experimental campaigns are presented.
9. Characterization and control of wafer charging effects during high-current ion implantation
International Nuclear Information System (INIS)
Current, M.I.; Lukaszek, W.; Dixon, W.; Vella, M.C.; Messick, C.; Shideler, J.; Reno, S.
1994-02-01
EEPROM-based sense and memory devices provide direct measures of the charge flow and potentials occurring on the surface of wafers during ion beam processing. Sensor design and applications for high current ion implantation are discussed
10. Atomic physics of highly charged ions in an electron beam ion trap
International Nuclear Information System (INIS)
Marrs, R.E.
1990-07-01
Two electron beam ion traps are in use at LLNL for the purpose of studying the properties of very highly charged ions and their interactions with electrons. This paper reviews the operation of the traps and discusses recent experiments in three areas: precision transition energy measurements in the limit of very high ion charge, dielectronic recombination measurements for the He-like isoelectronic sequence, and measurements of x-ray polarization. 22 refs., 11 figs., 1 tab
11. Acceleration of high charge density electron beams in the SLAC linac
International Nuclear Information System (INIS)
Sheppard, J.C.; Clendenin, J.E.; Jobe, R.K.; Lueth, V.G.; Millich, A.; Ross, M.C.; Seeman, J.T.; Stiening, R.F.
1984-01-01
The SLAC Linear Collider (SLC) will require both electron and positron beams of very high charge density and low emittance to be accelerated to about 50 GeV in the SLAC 3-km linac. The linac is in the process of being improved to meet this requirement. The program to accelerate an electron beam of high charge density through the first third of the SLC linac is described and the experimental results are discussed. 7 references, 5 figures
12. The effect of temperature on guiding of slow highly charged ions through a mesoscopic glass capillary
International Nuclear Information System (INIS)
Bereczky, R J; Tökési, K; Kowarik, G; Ladinig, F; Schrempf, D; Aumayr, F
2012-01-01
We present first temperature dependent transmission measurements of slow highly charged ions through a single, straight Duran glass capillary with a high aspect ratio. By changing the temperature of the glass capillary the electrical conductivity of the Duran can be varied by several orders of magnitude. This held the promise to investigate the effect of conductivity on particle transport (build-up and removal of charge patches) through capillaries in more details.
13. Charged particle tracking in high multiplicity events at RHIC
International Nuclear Information System (INIS)
Foley, K.J.; Love, W.A.
1985-01-01
It is generally accepted that the ability to track some fraction of the charged particles produced in heavy ion collisions is very desirable. At a very minimum, one must detect the occurance of multiple interactions in a single crossing. The very tight beam structure at RHIC does not favor time separation, so the location of separate vertices seems the best solution. The limits of tracking large numbers of tracks in a solid angle approaching 4π have been explored. A model detector considered is a 2.5 m radius TPC, a true 3D tracking device. In order to estimate the particle density of a function of production angle, five Hijet Au-Au central events were used to deduce the particle density distribution as a function of polar angle. An important feature of a tracking detector is the effective ''pixel'' size - the area within which two tracks cannot be resolved. In a TPC with multistep avalanche chamber readout this is approximately 3 mm x 3 mm or approx.0.1 cm 2 . Using this pixel size we have calculated the radius at which the number of particles/pixel is 0.01 and 0.1. With the exception of the region very near the beam expect these distributions aren't expected to change very much with the application of a low (approx. 0.5 tesla) magnetic field. While the actual reconstruction efficiency will depend on the fine details of the apparatus and reconstruction program, the 1% fill fraction is safe for efficiencies in the 80 to 90% region. Tracking is found to be feasible at pseudorapidities up to 3
14. Investigation on Interfacial Charge Transfer Process in CdSexTe1-x Alloyed Quantum Dot Sensitized Solar Cells
International Nuclear Information System (INIS)
Wei, Huiyun; Wang, Guoshuai; Luo, Yanhong; Li, Dongmei; Meng, Qingbo
2015-01-01
Colloidal QDs, typically, alloyed QDs with extending light absorption range, exhibit prospective application on quantum dot-sensitized solar cells (QDSCs). In this work, CdSe 0.8 Te 0.2 alloyed QDs have been employed to assemble QDSCs, and the influence of the photoanode structure and film thickness on the cell performance has been investigated in detail. Further study on the charge transport and interfacial electron transfer processes reveals that with the film thickness increasing, recombination possibility will be remarkably enhanced. By careful control on the balance between the light absorption and carrier recombination, an optimal double-layer photoanode structure with 11.5 μm-thickness transparent and 6 μm-thickness scattering layers can present a power conversion efficiency of 7.55%, which is one of the best records for the sandwiched-type QDSCs
15. Optimizing low-light microscopy with back-illuminated electron multiplying charge-coupled device: enhanced sensitivity, speed, and resolution.
Science.gov (United States)
Coates, Colin G; Denvir, Donal J; McHale, Noel G; Thornbury, Keith D; Hollywood, Mark A
2004-01-01
The back-illuminated electron multiplying charge-coupled device (EMCCD) camera is having a profound influence on the field of low-light dynamic cellular microscopy, combining highest possible photon collection efficiency with the ability to virtually eliminate the readout noise detection limit. We report here the use of this camera, in 512 x 512 frame-transfer chip format at 10-MHz pixel readout speed, in optimizing a demanding ultra-low-light intracellular calcium flux microscopy setup. The arrangement employed includes a spinning confocal Nipkow disk, which, while facilitating the need to both generate images at very rapid frame rates and minimize background photons, yields very weak signals. The challenge for the camera lies not just in detecting as many of these scarce photons as possible, but also in operating at a frame rate that meets the temporal resolution requirements of many low-light microscopy approaches, a particular demand of smooth muscle calcium flux microscopy. Results presented illustrate both the significant sensitivity improvement offered by this technology over the previous standard in ultra-low-light CCD detection, the GenIII+intensified charge-coupled device (ICCD), and also portray the advanced temporal and spatial resolution capabilities of the EMCCD. Copyright 2004 Society of Photo-Optical Instrumentation Engineers.
16. Arginine side chain interactions and the role of arginine as a gating charge carrier in voltage sensitive ion channels
Science.gov (United States)
Armstrong, Craig T.; Mason, Philip E.; Anderson, J. L. Ross; Dempsey, Christopher E.
2016-02-01
Gating charges in voltage-sensing domains (VSD) of voltage-sensitive ion channels and enzymes are carried on arginine side chains rather than lysine. This arginine preference may result from the unique hydration properties of the side chain guanidinium group which facilitates its movement through a hydrophobic plug that seals the center of the VSD, as suggested by molecular dynamics simulations. To test for side chain interactions implicit in this model we inspected interactions of the side chains of arginine and lysine with each of the 19 non-glycine amino acids in proteins in the protein data bank. The arginine guanidinium interacts with non-polar aromatic and aliphatic side chains above and below the guanidinium plane while hydrogen bonding with polar side chains is restricted to in-plane positions. In contrast, non-polar side chains interact largely with the aliphatic part of the lysine side chain. The hydration properties of arginine and lysine are strongly reflected in their respective interactions with non-polar and polar side chains as observed in protein structures and in molecular dynamics simulations, and likely underlie the preference for arginine as a mobile charge carrier in VSD.
17. Highly Selective and Sensitive Self-Powered Glucose Sensor Based on Capacitor Circuit.
Science.gov (United States)
Slaughter, Gymama; Kulkarni, Tanmay
2017-05-03
Enzymatic glucose biosensors are being developed to incorporate nanoscale materials with the biological recognition elements to assist in the rapid and sensitive detection of glucose. Here we present a highly sensitive and selective glucose sensor based on capacitor circuit that is capable of selectively sensing glucose while simultaneously powering a small microelectronic device. Multi-walled carbon nanotubes (MWCNTs) is chemically modified with pyrroloquinoline quinone glucose dehydrogenase (PQQ-GDH) and bilirubin oxidase (BOD) at anode and cathode, respectively, in the biofuel cell arrangement. The input voltage (as low as 0.25 V) from the biofuel cell is converted to a stepped-up power and charged to the capacitor to the voltage of 1.8 V. The frequency of the charge/discharge cycle of the capacitor corresponded to the oxidation of glucose. The biofuel cell structure-based glucose sensor synergizes the advantages of both the glucose biosensor and biofuel cell. In addition, this glucose sensor favored a very high selectivity towards glucose in the presence of competing and non-competing analytes. It exhibited unprecedented sensitivity of 37.66 Hz/mM.cm 2 and a linear range of 1 to 20 mM. This innovative self-powered glucose sensor opens new doors for implementation of biofuel cells and capacitor circuits for medical diagnosis and powering therapeutic devices.
18. Charge-state correlated cross sections for the production of low-velocity highly charged Ne ions by heavy-ion bombardment
International Nuclear Information System (INIS)
Gray, T.J.; Cocke, C.L.; Justiniano, E.
1980-01-01
We report measured cross sections for the collisional production of highly charged low-velocity Ne recoil ions resulting from the bombardment of a thin Ne gas target by highly charged 1-MeV/amu C, N, O, and F projectiles. The measurements were made using time-of-flight techniques which allowed the simultaneous identification of the final charge state of both the low-velocity recoil ion and the high-velocity projectile for each collision event. For a given incident-projectile charge state, the recoil charge-state distribution is very dependent upon the final charge state of the projectile. Single- and double-electron capture events by incident bare nuclei and projectile K-shell ionization during the collision cause large shifts in the recoil charge-state distributions toward higher charge states. A previously proposed energy-deposition model is modified to include the effects of projectile charge-changing collisions during the collision for bare and hydrogenlike projectiles and is used to discuss the present experimental results
19. Low to High Spin-State Transition Induced by Charge Ordering in Antiferromagnetic YBaCo2O5
International Nuclear Information System (INIS)
Vogt, T.; Woodward, P. M.; Karen, P.; Hunter, B. A.; Henning, P.; Moodenbaugh, A. R.
2000-01-01
The oxygen-deficient double perovskite YBaCo 2 O 5 , containing corner-linked CoO 5 square pyramids as principal building units, undergoes a paramagnetic to antiferromagnetic spin ordering at 330 K. This is accompanied by a tetragonal to orthorhombic distortion. Below 220 K orbital ordering and long-range Co 2+ /Co 3+ charge ordering occur as well as a change in the Co 2+ spin state from low to high spin. This transition is shown to be very sensitive to the oxygen content of the sample. To our knowledge this is the first observation of a spin-state transition induced by long-range orbital and charge ordering. (c) 2000 The American Physical Society
20. Retinal sensitivity and choroidal thickness in high myopia.
Science.gov (United States)
Zaben, Ahmad; Zapata, Miguel Á; Garcia-Arumi, Jose
2015-03-01
To estimate the association between choroidal thickness in the macular area and retinal sensitivity in eyes with high myopia. This investigation was a transversal study of patients with high myopia, all of whom had their retinal sensitivity measured with macular integrity assessment microperimetry. The choroidal thicknesses in the macular area were then measured by optical coherence tomography, and statistical correlations between their functionality and the anatomical structuralism, as assessed by both types of measurements, were analyzed. Ninety-six eyes from 77 patients with high myopia were studied. The patients had a mean age ± standard deviation of 38.9 ± 13.2 years, with spherical equivalent values ranging from -6.00 diopter to -20.00 diopter (8.74 ± 2.73 diopter). The mean central choroidal thickness was 159.00 ± 50.57. The mean choroidal thickness was directly correlated with sensitivity (r = 0.306; P = 0.004) and visual acuity but indirectly correlated with the spherical equivalent values and patient age. The mean sensitivity was not significantly correlated with the macular foveal thickness (r = -0.174; P = 0.101) or with the overall macular thickness (r = 0.103; P = 0.334); furthermore, the mean sensitivity was significantly correlated with visual acuity (r = 0.431; P < 0.001) and the spherical equivalent values (r = -0.306; P = 0.003). Retinal sensitivity in highly myopic eyes is directly correlated with choroidal thickness and does not seem to be associated with retinal thickness. Thus, in patients with high myopia, accurate measurements of choroidal thickness may provide more accurate information about this pathologic condition because choroidal thickness correlates to a greater degree with the functional parameters, patient age, and spherical equivalent values.
1. High-speed charge-to-time converter ASIC for the Super-Kamiokande detector
Energy Technology Data Exchange (ETDEWEB)
Nishino, H., E-mail: nishino@post.kek.j [Institute for Cosmic Ray Research, University of Tokyo, Chiba 277-8582 (Japan); Awai, K.; Hayato, Y.; Nakayama, S.; Okumura, K.; Shiozawa, M.; Takeda, A. [Institute for Cosmic Ray Research, University of Tokyo, Chiba 277-8582 (Japan); Ishikawa, K.; Minegishi, A. [Iwatsu Test Instruments Corporation, Tokyo 168-8511 (Japan); Arai, Y. [The Institute of Particle and Nuclear Studies, KEK, Ibaraki 305-0801 (Japan)
2009-11-11
A new application-specific integrated circuit (ASIC), the high-speed charge-to-time converter (QTC) IWATSU CLC101, provides three channels, each consisting of preamplifier, discriminator, low-pass filter, and charge integration circuitry, optimized for the waveform of a photomultiplier tube (PMT). This ASIC detects PMT signals using individual built-in discriminators and drives output timing signals whose width represents the integrated charge of the PMT signal. Combined with external input circuits composed of passive elements, the QTC provides full analog signal processing for the detector's PMTs, ready for further processing by time-to-digital converters (TDCs). High-rate (>1MHz) signal processing is achieved by short-charge-conversion-time and baseline-restoration circuits. Wide-range charge measurements are enabled by offering three gain ranges while maintaining a short cycle time. QTC chip test results show good analog performance, with efficient detection for a single photoelectron signal, four orders of magnitude dynamic range (0.3mVapprox3V; 0.2approx2500pC), 1% charge linearity, 0.2 pC charge resolution, and 0.1 ns timing resolution. Test results on ambient temperature dependence, channel isolation, and rate dependence also meet specifications.
2. High-speed charge-to-time converter ASIC for the Super-Kamiokande detector
International Nuclear Information System (INIS)
Nishino, H.; Awai, K.; Hayato, Y.; Nakayama, S.; Okumura, K.; Shiozawa, M.; Takeda, A.; Ishikawa, K.; Minegishi, A.; Arai, Y.
2009-01-01
A new application-specific integrated circuit (ASIC), the high-speed charge-to-time converter (QTC) IWATSU CLC101, provides three channels, each consisting of preamplifier, discriminator, low-pass filter, and charge integration circuitry, optimized for the waveform of a photomultiplier tube (PMT). This ASIC detects PMT signals using individual built-in discriminators and drives output timing signals whose width represents the integrated charge of the PMT signal. Combined with external input circuits composed of passive elements, the QTC provides full analog signal processing for the detector's PMTs, ready for further processing by time-to-digital converters (TDCs). High-rate (>1MHz) signal processing is achieved by short-charge-conversion-time and baseline-restoration circuits. Wide-range charge measurements are enabled by offering three gain ranges while maintaining a short cycle time. QTC chip test results show good analog performance, with efficient detection for a single photoelectron signal, four orders of magnitude dynamic range (0.3mV∼3V; 0.2∼2500pC), 1% charge linearity, 0.2 pC charge resolution, and 0.1 ns timing resolution. Test results on ambient temperature dependence, channel isolation, and rate dependence also meet specifications.
3. Two-frequency method for measuring Hall emf in high-resistive materials with charge-carrier low mobility
International Nuclear Information System (INIS)
Aleksandrov, A.L.; Vedeneev, A.S.; Gulyaev, I.B.; Zhdan, A.G.
1982-01-01
A facility for measuring Hall emf in high-resistive materials with low mobility of charge carriers by the two-frequency method using digital synchronous integration is described. The facility permits to detect the minimum Hall emf approxamatety equat to 5 μV at approximatety equal to 1 T Ohm of the investigated.sample resistance during the measuring time of approximately equal to 2000 s. Sensitivity by Hall mobility makes up >= 0.01 cm 2 /Vxs at the same measuring time. Measuring results of the Hall emf on GaAs monocrystals, CdSe films and island film of gold are presented
4. Overview on collision processes of highly charged ions with atoms present status and problems
International Nuclear Information System (INIS)
Janev, R.K.
1983-05-01
This paper provides a brief discussion on the present status of the collision physics of highly charged ions with atoms. The emphasis is on the main achievements in understanding and describing the most important collision processes, and as charge transfer, ionization and Auger-type processes, and even more on those open problems which, due either to their scientific or practical importance, represent challenges to current research in this field. The paper concentrates on general ideas and problems whose development and solutions have advanced or will advance our basic understanding of the collision dynamics of multiply charged ions with atoms
5. BH3105 type neutron dose equivalent meter of high sensitivity
International Nuclear Information System (INIS)
Ji Changsong; Zhang Enshan; Yang Jianfeng; Zhang Hong; Huang Jiling
1995-10-01
It is noted that to design a neutron dose meter of high sensitivity is almost impossible in the frame of traditional designing principle--'absorption net principle'. Based on a newly proposed principle of obtaining neutron dose equi-biological effect adjustment--' absorption stick principle', a brand-new neutron dose-equivalent meter with high neutron sensitivity BH3105 has been developed. Its sensitivity reaches 10 cps/(μSv·h -1 ), which is 18∼40 times higher than one of foreign products of the same kind and is 10 4 times higher than that of domestic FJ342 neutron rem-meter. BH3105 has a measurement range from 0.1μSv/h to 1 Sv/h which is 1 or 2 orders wider than that of the other's. It has the advanced properties of gamma-resistance, energy response, orientation, etc. (6 tabs., 5 figs.)
6. Performance of terahertz metamaterials as high-sensitivity sensor
Science.gov (United States)
He, Yanan; Zhang, Bo; Shen, Jingling
2017-09-01
A high-sensitivity sensor based on the resonant transmission characteristics of terahertz (THz) metamaterials was investigated, with the proposal and fabrication of rectangular bar arrays of THz metamaterials exhibiting a period of 180 μm on a 25 μm thick flexible polyimide. Varying the size of the metamaterial structure revealed that the length of the rectangular unit modulated the resonant frequency, which was verified by both experiment and simulation. The sensing characteristics upon varying the surrounding media in the sample were tested by simulation and experiment. Changing the surrounding medium from that of air to that of alcohol or oil produced resonant frequency redshifts of 80 GHz or 150 GHz, respectively, which indicates that the sensor possessed a high sensitivity of 667 GHz per unit of refractive index. Finally, the influence of the sample substrate thickness on the sensor sensitivity was investigated by simulation. It may be a reference for future sensor design.
7. The charge-transfer property and the performance of dye-sensitized solar cells of nitrogen doped zinc oxide
International Nuclear Information System (INIS)
Zhang Lingyun; Yang Yulin; Fan Ruiqing; Chen Haiyan; Jia Ruokun; Wang Yonghui; Ma Liqun; Wang Yazhen
2012-01-01
Highlights: ► Two methods (the solution and annealing methods) are used to prepare nitrogen-doped ZnO. ► The charge-transfer properties of N-doping ZnO are investigated. ► The overall conversion efficiency of N-doped ZnO-based dye-sensitized solar cells is successfully improved by N doping. - Abstract: In this study two methods, namely the solution and annealing methods, were used to prepare nitrogen-doped ZnO. The X-ray photoelectron spectroscopy (XPS) was performed to identify the composition and chemical states of N-doped ZnO. The N doping by the solution method was found to effectively decrease the acceptor effects. Surface photovoltage measurements (SPS) revealed a redshift of the threshold wavelength for the N-doped ZnO. And the recombination of photoinduced electron–hole pairs in this semiconductor material was obviously suppressed. The N-doped ZnO (solution method) exhibits the best performances among all the materials, even superior to N-doped ZnO (annealing method). Its J sc and η values (9.35 mA/cm 2 and 2.64%) have enhanced by several times compared with un-doped ZnO (J sc , 2.85 mA/cm 2 ; η, 0.67%). The overall conversion efficiency of ZnO-based dye-sensitized solar cells was successfully improved by the N doping.
8. Efficiency enhancement of hybridized solar cells through co-sensitization and fast charge extraction by up-converted polyethylene glycol modified carbon quantum dots
Science.gov (United States)
Zhu, Wanlu; Duan, Jialong; Duan, Yanyan; Zhao, Yuanyuan; Tang, Qunwei
2017-11-01
Photovoltaics are promising solutions to energy crisis and environmental pollution problems. The dye-sensitized solar cells with mesoscopic structures have attracted growing interests because of zero emissions, easy fabrication, scalable materials and techniques, etc. However, the state-of-the-art dye-sensitized solar cells have narrow spectral absorption for photoelectric conversion and high electron-hole recombination rate under sunlight illumination. Therefore, it is a persistent object to make wide-spectral absorption and fast charge extraction solar cells for energy harvest in both solar and dark-light conditions. To address this issue, we present here experimental realization of a category of solar cells converting visible and near-infrared light into electricity by co-sensitizing photoanode with N719 dye and polyethylene glycol (PEG) modified carbon quantum dots (PEG-m-CQDs), arising from up-conversion and hole-transporting behaviors of PEG-m-CQDs as well as photofluorescence of green-emitting long persistence phosphors. The optimized solar cell yields maximized photoelectric conversion efficiencies of 9.89% and 25.81% under simulated sunlight (air mass 1.5, 100 mW cm-2) illumination and dark conditions, respectively. This work is far from optimization, but the physical proof-of-concept hybridized solar cell may markedly increase electricity generation time and total power output of photovoltaic platforms.
9. Benchmark of Space Charge Simulations and Comparison with Experimental Results for High Intensity, Low Energy Accelerators
CERN Document Server
Cousineau, Sarah M
2005-01-01
Space charge effects are a major contributor to beam halo and emittance growth leading to beam loss in high intensity, low energy accelerators. As future accelerators strive towards unprecedented levels of beam intensity and beam loss control, a more comprehensive understanding of space charge effects is required. A wealth of simulation tools have been developed for modeling beams in linacs and rings, and with the growing availability of high-speed computing systems, computationally expensive problems that were inconceivable a decade ago are now being handled with relative ease. This has opened the field for realistic simulations of space charge effects, including detailed benchmarks with experimental data. A great deal of effort is being focused in this direction, and several recent benchmark studies have produced remarkably successful results. This paper reviews the achievements in space charge benchmarking in the last few years, and discusses the challenges that remain.
10. Sensitive high performance liquid chromatographic method for the ...
African Journals Online (AJOL)
A new simple, sensitive, cost-effective and reproducible high performance liquid chromatographic (HPLC) method for the determination of proguanil (PG) and its metabolites, cycloguanil (CG) and 4-chlorophenylbiguanide (4-CPB) in urine and plasma is described. The extraction procedure is a simple three-step process ...
11. Methylation-Sensitive High Resolution Melting (MS-HRM).
Science.gov (United States)
Hussmann, Dianna; Hansen, Lise Lotte
2018-01-01
Methylation-Sensitive High Resolution Melting (MS-HRM) is an in-tube, PCR-based method to detect methylation levels at specific loci of interest. A unique primer design facilitates a high sensitivity of the assays enabling detection of down to 0.1-1% methylated alleles in an unmethylated background.Primers for MS-HRM assays are designed to be complementary to the methylated allele, and a specific annealing temperature enables these primers to anneal both to the methylated and the unmethylated alleles thereby increasing the sensitivity of the assays. Bisulfite treatment of the DNA prior to performing MS-HRM ensures a different base composition between methylated and unmethylated DNA, which is used to separate the resulting amplicons by high resolution melting.The high sensitivity of MS-HRM has proven useful for detecting cancer biomarkers in a noninvasive manner in urine from bladder cancer patients, in stool from colorectal cancer patients, and in buccal mucosa from breast cancer patients. MS-HRM is a fast method to diagnose imprinted diseases and to clinically validate results from whole-epigenome studies. The ability to detect few copies of methylated DNA makes MS-HRM a key player in the quest for establishing links between environmental exposure, epigenetic changes, and disease.
12. Aluminum nano-cantilevers for high sensitivity mass sensors
DEFF Research Database (Denmark)
Davis, Zachary James; Boisen, Anja
2005-01-01
We have fabricated Al nano-cantilevers using a very simple one mask contact UV lithography technique with lateral dimensions under 500 nm and vertical dimensions of approximately 100 nm. These devices are demonstrated as highly sensitive mass sensors by measuring their dynamic properties. Further...
13. High sensitivity probe absorption technique for time-of-flight ...
Abstract. We report on a phase-sensitive probe absorption technique with high sen- sitivity, capable of detecting a few hundred ultra-cold atoms in flight in an observation time of a few milliseconds. The large signal-to-noise ratio achieved is sufficient for reliable measurements on low intensity beams of cold atoms.
14. Moment-Preserving Computational Approach for High Energy Charged Particle Transport
Science.gov (United States)
2016-05-16
posed, but with modified cross sections such that the resulting single-event Monte Carlo simulation is computationally efficient (minutes vs . days...configurations, which are all characteristics of real world applications. In other words , it is possible to simulate real, physical phenomena using charged...0 < 0.95) ~ 1 2() ≫ 1, (3) Demonstrating that scattering is highly forward peaked. Thus, the picture of charged particle interactions
15. Search for Fractionally Charged Nuclei in High-Energy Oxygen-Lead Collisions
CERN Multimedia
2002-01-01
We propose to use stacks of CR-39 plastic track detectors to look for fractionally charged projectile fragments produced in collisions of high-energy oxygen, sulfur, and calcium nuclei with a lead target. The expected charge resolution is @s^z~=~0.06e for fragments with 17e/3~@$<$~Z~@$<$~23e/3. We request that two target + stack assemblies be exposed to 1~x~10|5 oxygen nuclei at maximum available energy.
16. Gain reduction due to space charge at high counting rates in multiwire proportional chambers
International Nuclear Information System (INIS)
Smith, G.C.; Mathieson, E.
1986-10-01
Measurements with a small MWPC of gas gain reduction, due to ion space charge at high counting rates, have been compared with theoretical predictions. The quantity ln(q/q 0 )/(q/q 0 ), where (q/q 0 ) is the relative reduced avalanche charge, has been found to be closely proportional to count rate, as predicted. The constant of proportionality is in good agreement with calculations made with a modified version of the original, simplified theory
17. Evaporative cooling of highly charged ions in EBIT [Electron Beam Ion Trap]: An experimental realization
International Nuclear Information System (INIS)
Schneider, M.B.; Levine, M.A.; Bennett, C.L.; Henderson, J.R.; Knapp, D.A.; Marrs, R.E.
1988-01-01
Both the total number and trapping lifetime of near-neon-like gold ions held in an electron beam ion trap have been greatly increased by a process of 'evaporative cooling'. A continuous flow of low-charge-state ions into the trap cools the high-charge-state ions in the trap. Preliminary experimental results using titanium ions as a coolant are presented. 8 refs., 6 figs., 2 tabs
18. Charge fluctuations in high-electron-mobility transistors: a review
International Nuclear Information System (INIS)
Green, F.
1993-01-01
The quasi-two-dimensional carrier population, free to move within a near-perfect crystalline matrix, is the key to remarkable improvements in signal gain, current density and quiet operation. Current-fluctuation effects are central to all of these properties. Some of these are easily understood within linear-response theory, but other fluctuation phenomena are less tractable. In particular, nonequilibrium noise poses significant theoretical challenges, both descriptive and predictive. This paper examines a few of the basic physical issues which motivate device-noise theory. The structure and operation of high-electron-mobility transistor are first reviewed. The recent nonlinear fluctuation theory of Stanton and Wilkins (1987) help to identify at least some of the complicated noise physics which can arise when carriers in GaAs-like conduction bands are subjected to high fields. Simple examples of fluctuation-dominated behaviour are discussed, with numerical illustrations. 20 refs., 9 figs
19. Highly sensitive detection using microring resonator and nanopores
Science.gov (United States)
Bougot-Robin, K.; Hoste, J. W.; Le Thomas, N.; Bienstman, P.; Edel, J. B.
2016-04-01
One of the most significant challenges facing physical and biological scientists is the accurate detection and identification of single molecules in free-solution environments. The ability to perform such sensitive and selective measurements opens new avenues for a large number of applications in biological, medical and chemical analysis, where small sample volumes and low analyte concentrations are the norm. Access to information at the single or few molecules scale is rendered possible by a fine combination of recent advances in technologies. We propose a novel detection method that combines highly sensitive label-free resonant sensing obtained with high-Q microcavities and position control in nanoscale pores (nanopores). In addition to be label-free and highly sensitive, our technique is immobilization free and does not rely on surface biochemistry to bind probes on a chip. This is a significant advantage, both in term of biology uncertainties and fewer biological preparation steps. Through combination of high-Q photonic structures with translocation through nanopore at the end of a pipette, or through a solid-state membrane, we believe significant advances can be achieved in the field of biosensing. Silicon microrings are highly advantageous in term of sensitivity, multiplexing, and microfabrication and are chosen for this study. In term of nanopores, we both consider nanopore at the end of a nanopipette, with the pore being approach from the pipette with nanoprecise mechanical control. Alternatively, solid state nanopores can be fabricated through a membrane, supporting the ring. Both configuration are discussed in this paper, in term of implementation and sensitivity.
20. Direct electron-pair production by high energy heavy charged particles
Science.gov (United States)
Takahashi, Y.; Gregory, J. C.; Hayashi, T.; Dong, B. L.
1989-01-01
Direct electron pain production via virtual photons by moving charged particles is a unique electro-magnetic process having a substantial dependence on energy. Most electro-magnetic processes, including transition radiation, cease to be sensitive to the incident energy above 10 TeV/AMU. Thus, it is expected, that upon establishment of cross section and detection efficiency of this process, it may provide a new energy measuring technique above 10 TeV/AMU. Three accelerator exposures of emulsion chambers designed for measurements of direct electron-pains were performed. The objectives of the investigation were to provide the fundamental cross-section data in emulsion stacks to find the best-fit theoretical model, and to provide a calibration of measurements of direct electron-pairs in emulsion chamber configurations. This paper reports the design of the emulsion chambers, accelerator experiments, microscope measurements, and related considerations for future improvements of the measurements, and for possible applications to high energy cosmic ray experiments. Also discussed are the results from scanning 56m of emulsion tracks at 1200x magnification so that scanning efficiency is optimized. Measurements of the delta-ray range spectrum were also performed for much shorter track lengths, but with sufficiently large statistics in the number of measured delta-rays.
1. NK sensitivity of neuroblastoma cells determined by a highly sensitive coupled luminescent method
International Nuclear Information System (INIS)
Ogbomo, Henry; Hahn, Anke; Geiler, Janina; Michaelis, Martin; Doerr, Hans Wilhelm; Cinatl, Jindrich
2006-01-01
The measurement of natural killer (NK) cells toxicity against tumor or virus-infected cells especially in cases with small blood samples requires highly sensitive methods. Here, a coupled luminescent method (CLM) based on glyceraldehyde-3-phosphate dehydrogenase release from injured target cells was used to evaluate the cytotoxicity of interleukin-2 activated NK cells against neuroblastoma cell lines. In contrast to most other methods, CLM does not require the pretreatment of target cells with labeling substances which could be toxic or radioactive. The effective killing of tumor cells was achieved by low effector/target ratios ranging from 0.5:1 to 4:1. CLM provides highly sensitive, safe, and fast procedure for measurement of NK cell activity with small blood samples such as those obtained from pediatric patients
2. Instruction manual for ORNL tandem high abundance sensitivity mass spectrometer
International Nuclear Information System (INIS)
Smith, D.H.; McKown, H.S.; Chrisite, W.H.; Walker, R.L.; Carter, J.A.
1976-06-01
This manual describes the physical characteristics of the tandem mass spectrometer built by Oak Ridge National Laboratory for the International Atomic Energy Agency. Specific requirements met include ability to run small samples, high abundance sensitivity, good precision and accuracy, and adequate sample throughput. The instrument is capable of running uranium samples as small as 10 -12 g and has an abundance sensitivity in excess of 10 6 . Precision and accuracy are enhanced by a special sweep control circuit. Sample throughput is 6 to 12 samples per day. Operating instructions are also given
3. A highly sensitive and specific assay for vertebrate collagenase
International Nuclear Information System (INIS)
Sodek, J.; Hurum, S.; Feng, J.
1981-01-01
A highly sensitive and specific assay for vertebrate collagenase has been developed using a [ 14 C]-labeled collagen substrate and a combination of SDS-PAGE (sodium dodecyl sulfate-polyacrylamide gel electrophoresis) and fluorography to identify and quantitate the digestion products. The assay was sufficiently sensitive to permit the detection and quantitation of collagenase activity in 0.1 μl of gingival sulcal fluid, and in samples of cell culture medium without prior concentration. The assay has also been used to detect the presence of inhibitors of collagenolytic enzymes in various cell culture fluids. (author)
4. High Pressure Optical Studies of the Thallous Halides and of Charge-Transfer Complexes
Science.gov (United States)
Jurgensen, Charles Willard
High pressure was used to study the insulator -to-metal transition in sulfur and the thallous halides and to study the intermolecular interactions in charge -transfer complexes. The approach to the band overlap insulator -to-metal transition was studied in three thallous halides and sulfur by optical absorption measurements of the band gap as a function of pressure. The band gap of sulfur continuously decreases with pressure up to the insulator -to-metal transition which occurs between 450 and 485 kbars. The results on the thallous halides indicate that the indirect gap decreases more rapidly than the direct gap; the closing of the indirect gap is responsible for the observed insulator -to-metal transitions. High pressure electronic and vibrational spectroscopic measurements on the solid-state complexes of HMB-TCNE were used to study the intermolecular interactions of charge -transfer complexes. The vibrational frequency shifts indicate that the degree of charge transfer increases with pressure which is independently confirmed by an increase in the molar absorptivity of the electronic charge-transfer peak. Induction and dispersion forces contribute towards a red shift of the charge-transfer peak; however, charge-transfer resonance contributes toward a blue shift and this effect is dominant for the HMB-TCNE complexes. High pressure electronic spectra were used to study the effect of intermolecular interactions on the electronic states of TCNQ and its complexes. The red shifts with pressure of the electronic spectra of TCNQ and (TCNQ)(' -) in polymer media and of crystalline TCNQ can be understood in terms of Van der Waals interactions. None of the calculations which considered intradimer distance obtained the proper behavior for either the charge-transfer of the locally excited states of the complexes. The qualitative behavior of both states can be interpreted as the effect of increased mixing of the locally excited and charge transfer states.
5. Multi-frequency inversion-charge pumping for charge separation and mobility analysis in high-k/InGaAs metal-oxide-semiconductor field-effect transistors
Energy Technology Data Exchange (ETDEWEB)
Djara, V.; Cherkaoui, K.; Negara, M. A.; Hurley, P. K., E-mail: paul.hurley@tyndall.ie [Tyndall National Institute, University College Cork, Dyke Parade, Cork (Ireland)
2015-11-28
An alternative multi-frequency inversion-charge pumping (MFICP) technique was developed to directly separate the inversion charge density (N{sub inv}) from the trapped charge density in high-k/InGaAs metal-oxide-semiconductor field-effect transistors (MOSFETs). This approach relies on the fitting of the frequency response of border traps, obtained from inversion-charge pumping measurements performed over a wide range of frequencies at room temperature on a single MOSFET, using a modified charge trapping model. The obtained model yielded the capture time constant and density of border traps located at energy levels aligned with the InGaAs conduction band. Moreover, the combination of MFICP and pulsed I{sub d}-V{sub g} measurements enabled an accurate effective mobility vs N{sub inv} extraction and analysis. The data obtained using the MFICP approach are consistent with the most recent reports on high-k/InGaAs.
6. Electron transfer and decay processes of highly charged iodine ions
International Nuclear Information System (INIS)
Sakaue, Hiroyuki A.; Danjo, Atsunori; Hosaka, Kazumoto
2005-01-01
In the present experimental work we have investigated multi-electron transfer processes in I q+ (q=10, 15, 20 and 25) + Ne, Ar, Kr and Xe collisions at 1.5q keV energy. The branching ratios between Auger and radiative decay channels have been measured in decay processes of multiply excited states formed by multi-electron transfer collisions. It has been shown that, in all the multi-electron transfer processes investigated, the Auger decays are far dominant over the radiative decay processes and the branching ratios are clearly characterized by the average principal quantum number of the initial excited states of projectile ions. We could express the branching ratios in high Rydberg states formed in multi-electron transfer processes by using the decay probability of one Auger electron emission. (author)
7. X-ray transitions in highly charged neonlike ions
International Nuclear Information System (INIS)
Beiersdorfer, P.; von Gjoeler, S.; Bitter, M.
1987-11-01
Wavelength measurements of n=3 to n=2 transitions in neonlike Xe 44+ , La 47+ , Nd 50+ , and Eu 53+ have been made using a high-resolution Bragg-crystal spectrometer on the Princeton Large Torus tokamak. The measurements cover the wavelength regions 2.00 to 3.00 (angstrom) and include the electric dipole, and the electric and magnetic quadrupole transitions. The measured wavelengths are compared to energy levels obtained from a multiconfigurational Dirac-Fock calculation. Systematic differences between the experimental and theoretical values are found, which vary smoothly with atomic number. The magnitude of the differences depends on the particular type of transition and ranges from -2.8 eV to +2.2 eV. Inclusion of electron correlation corrections due to ground state correlations and (super) Coster-Kronig type fluctuations in the theoretical energies is shown to reduce the differences for some but not all types of transitions
8. Uncharted Frontiers in the Spectroscopy of Highly Charged Ions
CERN Document Server
Beiersdorfer, P; Crespo, J; Kim, S H; Neill, P; Utter, S; Widmann, K
2000-01-01
The development of novel techniques is critical for maintaining a state-of-the-art core competency in atomic physics and readiness for evolving programmatic needs. We have carried out a three-year effort to develop novel spectroscopic instrumentation that added new dimensions to our capabilities for measuring energy levels, radiative transition probabilities, and electron-ion excitation processes. The new capabilities created were in areas that heretofore had been inaccessible to scientific scrutiny and included high-resolution spectroscopy of hard x rays, femtosecond lifetime measurements, measurements of transition probabilities of long-lived metastable levels, polarization spectroscopy, ultra-precise determinations of energy levels, and the establishment of absolute wavelength standards in x-ray spectroscopy. Instrumentation developed during the period included a transmission-type crystal spectrometer, a flat-field EUV spectrometer, and the development and deployment of absolutely calibrated monolithic cry...
9. Beam dynamics of mixed high intensity highly charged ion Beams in the Q/A selector
Energy Technology Data Exchange (ETDEWEB)
Zhang, X.H., E-mail: zhangxiaohu@impcas.ac.cn [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Yuan, Y.J.; Yin, X.J.; Qian, C.; Sun, L.T. [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Du, H.; Li, Z.S.; Qiao, J.; Wang, K.D. [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Zhao, H.W.; Xia, J.W. [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)
2017-06-11
Electron cyclotron resonance (ECR) ion sources are widely used in heavy ion accelerators for their advantages in producing high quality intense beams of highly charged ions. However, it exists challenges in the design of the Q/A selection systems for mixed high intensity ion beams to reach sufficient Q/A resolution while controlling the beam emittance growth. Moreover, as the emittance of beam from ECR ion sources is coupled, the matching of phase space to post accelerator, for a wide range of ion beam species with different intensities, should be carefully studied. In this paper, the simulation and experimental results of the Q/A selection system at the LECR4 platform are shown. The formation of hollow cross section heavy ion beam at the end of the Q/A selector is revealed. A reasonable interpretation has been proposed, a modified design of the Q/A selection system has been committed for HIRFL-SSC linac injector. The features of the new design including beam simulations and experiment results are also presented.
10. High throughput on-chip analysis of high-energy charged particle tracks using lensfree imaging
Energy Technology Data Exchange (ETDEWEB)
Luo, Wei; Shabbir, Faizan; Gong, Chao; Gulec, Cagatay; Pigeon, Jeremy; Shaw, Jessica; Greenbaum, Alon; Tochitsky, Sergei; Joshi, Chandrashekhar [Electrical Engineering Department, University of California, Los Angeles, California 90095 (United States); Ozcan, Aydogan, E-mail: ozcan@ucla.edu [Electrical Engineering Department, University of California, Los Angeles, California 90095 (United States); Bioengineering Department, University of California, Los Angeles, California 90095 (United States); California NanoSystems Institute (CNSI), University of California, Los Angeles, California 90095 (United States)
2015-04-13
We demonstrate a high-throughput charged particle analysis platform, which is based on lensfree on-chip microscopy for rapid ion track analysis using allyl diglycol carbonate, i.e., CR-39 plastic polymer as the sensing medium. By adopting a wide-area opto-electronic image sensor together with a source-shifting based pixel super-resolution technique, a large CR-39 sample volume (i.e., 4 cm × 4 cm × 0.1 cm) can be imaged in less than 1 min using a compact lensfree on-chip microscope, which detects partially coherent in-line holograms of the ion tracks recorded within the CR-39 detector. After the image capture, using highly parallelized reconstruction and ion track analysis algorithms running on graphics processing units, we reconstruct and analyze the entire volume of a CR-39 detector within ∼1.5 min. This significant reduction in the entire imaging and ion track analysis time not only increases our throughput but also allows us to perform time-resolved analysis of the etching process to monitor and optimize the growth of ion tracks during etching. This computational lensfree imaging platform can provide a much higher throughput and more cost-effective alternative to traditional lens-based scanning optical microscopes for ion track analysis using CR-39 and other passive high energy particle detectors.
11. High pressure study of high temperatures superconductors: Material base, universal Tc-behavior, and charge transfer
International Nuclear Information System (INIS)
Chu, C.W.; Hor, P.H.; Lin, J.G.; Xiong, Q.; Huang, Z.J.; Meng, R.L.; Xue, Y.Y.; Jean, Y.C.
1991-01-01
The superconducting transition temperature (T c ) has been measured in YBa 2 Cu 3 O 6.7 , YBa 2 Cu 3 O 7 , Y 2 Ba 4 Cu 7 O 15 , YBa 2 Cu 4 O 8 , Tl 2 Ba 2 Ca n-1 Cu n O n+4-δ , La 2-x Sr x CuO 4 , and La 2-x Ba x CuO 4 under high pressures. The pressure effect on the positron lifetime (τ) has also been determined in the first four compounds. Based on these and other high pressure data, the authors suggest that (1) all known cuprate high temperature superconductors (HTS's) may be no more than mere modifications of either 214-T, 214-T', 123, or a combination of 214-T' and 123, (2) a nonmonotonic T c -behavior may govern the T c -variation of all hole cuprate HTS's and (3) pressure can induce charge transfer leading to a T c -change. The implications of these suggestions will also be discussed
12. Evaporation and discharge dynamics of highly charged multicomponent droplets generated by electrospray ionization.
Science.gov (United States)
Grimm, Ronald L; Beauchamp, J L
2010-01-28
We investigate the Rayleigh discharge and evaporation dynamics of highly charged two-component droplets consisting principally of methanol with 2-methoxyethanol, tert-butanol, or m-nitrobenzyl alcohol. A phase Doppler anemometer (PDA) characterizes droplets generated by electrospray ionization (ESI) according to size, velocity, and charge as they move through a uniform electric field within an ion mobility spectrometer (IMS). Repeated field reversals result in droplet "ping-pong" through the PDA. This generates individual droplet histories of solvent evaporation behavior and the dynamics of charge loss to progeny droplets during Rayleigh discharge events. On average, methanol droplets discharge at 127% their Rayleigh limit of charge, q(R), and release 25% of the net charge. Charge loss from methanol/2-methoxyethanol droplets behaves similarly to pure 2-methoxyethanol droplets which release approximately 28% of their net charge. Binary methanol droplets containing up to 50% tert-butanol discharge at a lower percent q(R) than pure methanol and release a greater fraction of their net charge. Mixed 99% methanol/1% m-nitrobenzyl alcohol droplets possess discharge characteristics similar to those of methanol. However, droplets of methanol containing 2% m-nitrobenzyl evaporate down to a fixed size and charge that remains constant with no observable discharges. Quasi-steady-state evaporation models accurately describe observed evaporation phenomena in which methanol/tert-butanol droplets evaporate at a rate similar to that of pure methanol and methanol/2-methoxyethanol droplets evaporate at a rate similar to that of 2-methoxyethanol. We compare these results to previous Rayleigh discharge experiments and discuss the implications for binary solvents in electrospray mass spectrometry (ESI-MS) and field-induced droplet ionization mass spectrometry (FIDI-MS).
13. Sensitive measurement of vinorelbine in dog plasma by liquid chromatography-electrospray ionization tandem mass spectrometry utilizing transitions from double-charged precursor ions.
Science.gov (United States)
Niwa, Makoto; Kawashiro, Takashi
2011-04-01
A sensitive high-performance liquid chromatography/tandem mass spectrometry (LC/MS/MS) method for measuring vinorelbine was developed. A 100 µL aliquot of plasma was spiked with deuterium-labeled internal standard and subjected to solid-phase extraction using an Oasis HLB μ-elution plate. Two microliters of the extracted samples was directly injected into LC/MS/MS. Chromatographic separation was achieved on a Capcell Pak C18 UG column (2 × 75 mm) with a gradient elution of methanol (mobile phase B) against 0.05% formic acid in aqueous 10 mm ammonium formate (mobile phase A). The LC flow rate was set to 0.28 mL/min and the gradient (solvent B concentration) was processed from 40 to 90%. In mass spectrometric detection, observation of the reaction from a double-charged precursor ion [M + 2H](2+) (m/z 390) to product ion m/z 122 provided very high sensitivity. The method was validated with a lower limit of detection of 0.2 ng/mL with 0.1 mL of plasma, and the method was used to determine the plasma pharmacokinetics of vinorelbine in dogs. Copyright © 2010 John Wiley & Sons, Ltd.
14. Are inflationary predictions sensitive to very high energy physics?
International Nuclear Information System (INIS)
Burgess, C.P.; Lemieux, F.; Holman, R.; Cline, J.M.
2003-01-01
It has been proposed that the successful inflationary description of density perturbations on cosmological scales is sensitive to the details of physics at extremely high (trans-Planckian) energies. We test this proposal by examining how inflationary predictions depend on higher-energy scales within a simple model where the higher-energy physics is well understood. We find the best of all possible worlds: inflationary predictions are robust against the vast majority of high-energy effects, but can be sensitive to some effects in certain circumstances, in a way which does not violate ordinary notions of decoupling. This implies both that the comparison of inflationary predictions with CMB data is meaningful, and that it is also worth searching for small deviations from the standard results in the hopes of learning about very high energies. (author)
15. Review of highly charged heavy ion production with electron cyclotron resonance ion source (invited)
International Nuclear Information System (INIS)
Nakagawa, T.
2014-01-01
The electron cyclotron resonance ion source (ECRIS) plays an important role in the advancement of heavy ion accelerators and other ion beam applications worldwide, thanks to its remarkable ability to produce a great variety of intense highly charged heavy ion beams. Great efforts over the past decade have led to significant ECRIS performance improvements in both the beam intensity and quality. A number of high-performance ECRISs have been built and are in daily operation or are under construction to meet the continuously increasing demand. In addition, comprehension of the detailed and complex physical processes in high-charge-state ECR plasmas has been enhanced experimentally and theoretically. This review covers and discusses the key components, leading-edge developments, and enhanced ECRIS performance in the production of highly charged heavy ion beams
16. Design of highly sensitive multichannel bimetallic photonic crystal fiber biosensor
Science.gov (United States)
Hameed, Mohamed Farhat O.; Alrayk, Yassmin K. A.; Shaalan, Abdelhamid A.; El Deeb, Walid S.; Obayya, Salah S. A.
2016-10-01
A design of a highly sensitive multichannel biosensor based on photonic crystal fiber is proposed and analyzed. The suggested design has a silver layer as a plasmonic material coated by a gold layer to protect silver oxidation. The reported sensor is based on detection using the quasi transverse electric (TE) and quasi transverse magnetic (TM) modes, which offers the possibility of multichannel/multianalyte sensing. The numerical results are obtained using a finite element method with perfect matched layer boundary conditions. The sensor geometrical parameters are optimized to achieve high sensitivity for the two polarized modes. High-refractive index sensitivity of about 4750 nm/RIU (refractive index unit) and 4300 nm/RIU with corresponding resolutions of 2.1×10-5 RIU, and 2.33×10-5 RIU can be obtained according to the quasi TM and quasi TE modes of the proposed sensor, respectively. Further, the reported design can be used as a self-calibration biosensor within an unknown analyte refractive index ranging from 1.33 to 1.35 with high linearity and high accuracy. Moreover, the suggested biosensor has advantages in terms of compactness and better integration of microfluidics setup, waveguide, and metallic layers into a single structure.
17. A High-Level Functional Architecture for GNSS-Based Road Charging Systems
DEFF Research Database (Denmark)
Zabic, Martina
2011-01-01
, a short introduction is provided followed by a presentation of the system engineering methodology to illustrate how and why system architectures can be beneficial for GNSS-based road charging systems. Hereafter, a basic set of system functions is determined based on functional system requirements, which...... charging systems, it is important to highlight the overall system architecture which is the framework that defines the basic functions and important concepts of the system. This paper presents a functional architecture for GNSS-based road charging systems based on the concepts of system engineering. First...... defines the necessary tasks that these systems must accomplish. Finally, this paper defines the system functionalities; and provides a generic high-level functional architecture for GNSS-based road charging systems....
18. Practical Approaches to Mitigation of Specimen Charging in High-Resolution Transmission Electron Microscopy
Directory of Open Access Journals (Sweden)
Young-Min Kim
2010-09-01
Full Text Available Specimen charging that is associated with the electron bombardment on the sample is a practical hindrance to high-resolution transmission electron microscopy (HRTEM analysis because it causes a severe loss of resolution in either diffraction or image data. Conductive thin film deposition on an insulating specimen has been proposed as an effective approach to the mitigation of the specimen charging; however, this method is generally not useful in HRTEM imaging of materials because the deposited film induces another artifact in the HRTEM image contrast. In this study, we propose practical methods to mitigate the specimen charging that takes place during the HRTEM of materials. For bulk-type specimens prepared by either an ion-thinning or focused-ion beam (FIB process, a plasma cleaning treatment is significantly effective in eliminating the charging phenomenon. In the case of low-dimensional nanomaterials such as nanowires and nanoparticles, the plasma cleaning is not feasible; however, the charging effect can be effectively eliminated by adjusting the electron illumination condition. The proposed methods facilitate a decrease in the buildup of specimen charging, thereby enhancing the quality of high-resolution images significantly.
19. Techniques for enhancing the performance of high charge state ECR ion sources
International Nuclear Information System (INIS)
Xie, Z.Q.
1999-01-01
Electron Cyclotron Resonance ion source (ECRIS), which produces singly to highly charged ions, is widely used in heavy ion accelerators and is finding applications in industry. It has progressed significantly in recent years thanks to a few techniques, such as multiple-frequency plasma heating, higher mirror magnetic fields and a better cold electron donor. These techniques greatly enhance the production of highly charged ions. More than 1 emA of He 2+ and O 6+ , hundreds of eμA of O 7+ , Ne 8+ , Ar 12+ , more than 100 eμA of intermediate heavy ions with charge states up to Ne 9+ , Ar 13+ , Ca 13+ , Fe 13+ , Co 14+ and Kr 18+ , tens of eμA of heavy ions with charge states up to Xe 28+ , Au 35+ , Bi 34+ and U 34+ were produced at cw mode operation. At an intensity of about 1 eμA, the charge states for the heavy ions increased up to Xe 36+ , Au 46+ , Bi 47+ and U 48+ . More than an order of magnitude enhancement of fully stripped argon ions was achieved (I≥0.1 and h;eμA). Higher charge state ions up to Kr 35+ , Xe 46+ and U 64+ at low intensities were produced for the first time from an ECRIS. copyright 1999 American Institute of Physics
20. Extraction Compression and Acceleration of High Line Charge Density Ion Beams
CERN Document Server
Henestroza, Enrique; Grote, D P; Peters, Craig; Yu, Simon
2005-01-01
HEDP applications require high line charge density ion beams. An efficient method to obtain this type of beams is to extract a long pulse, high current beam from a gun at high energy, and let the beam pass through a decelerating field to compress it. The low energy beam bunch is loaded into a solenoid and matched to a Brillouin flow. The Brillouin equilibrium is independent of the energy if the relationship between the beam size (a), solenoid magnetic field strength (B) and line charge density is such that (Ba)2
1. New experimental initiatives using very highly charged ions from an 'electron beam ion trap'
International Nuclear Information System (INIS)
Schneider, D.
1996-01-01
A short review of the experimental program in highly-charged heavy ion physics conducted at the Lawrence Livermore National Laboratory Electron Beam Ion Trap (EBIT) facility is presented. The heavy-ion research, involving ions up to fully stripped U 92+ , includes precision x-ray spectroscopy and lifetime studies, electron impact ionization and excitation cross section measurements. The investigations of ion-surface interactions following the impact of high-Z highly charged ions on surfaces are aimed to study the neutralization dynamics effecting the ion and the response of the surface as well. (author)
2. Charge-exchange-induced formation of hollow atoms in high-intensity laser-produced plasmas
Energy Technology Data Exchange (ETDEWEB)
Rosmej, F.B. [TU-Darmstadt, Institut fuer Kernphysik, Darmstadt (Germany); Faenov, A.Ya.; Pikuz, T.A.; Magunov, A.I.; Skobelev, I.Yu. [Multicharged Ions Spectra Data Center of VNIIFTRI, Mendeleevo (Russian Federation); Auguste, T.; D' Oliveira, P.; Hulin, S.; Monot, P. [Commissariat a lEnergie Atomique DSM/DRECAM/SPAM, Gif-Sur-Yvette Cedex (France); Andreev, N.E.; Chegotov, M.V.; Veisman, M.E. [High Energy Density Research Centre, Institute of High Temperatures of Russian Academy of Sciences, Moscow (Russian Federation)
1999-03-14
For the first time registration of high-resolution soft x-ray emission and atomic data calculations of hollow-atom dielectronic satellite spectra of highly charged nitrogen have been performed. Double-electron charge-exchange processes from excited states are proposed for the formation of autoionizing levels nln'l' in high-intensity laser-produced plasmas, when field-ionized ions penetrate into the residual gas. Good agreement is found between theory and experiment. Plasma spectroscopy with hollow ions is proposed and a temperature diagnostic for laser-produced plasmas in the long-lasting recombining regime is developed. (author). Letter-to-the-editor.
3. Charge sniffer for electrostatics demonstrations
Science.gov (United States)
Dinca, Mihai P.
2011-02-01
An electronic electroscope with a special design for demonstrations and experiments on static electricity is described. It operates as an electric charge sniffer by detecting slightly charged objects when they are brought to the front of its sensing electrode. The sniffer has the advantage of combining high directional sensitivity with a logarithmic bar display. It allows for the identification of electric charge polarity during charge separation by friction, peeling, electrostatic induction, batteries, or secondary coils of power transformers. Other experiments in electrostatics, such as observing the electric field of an oscillating dipole and the distance dependence of the electric field generated by simple charge configurations, are also described.
4. Charge-sign-clustering observed in high-multiplicity, high-energy heavy-ion collisions
International Nuclear Information System (INIS)
Takahashi, Y.; Gregory, J.C.; Hayashi, T.
1989-01-01
Charge-sign distribution in 200 GeV/amu heavy-ion collisions is studied with the Magnetic-Interferometric-Emulsion-Chamber (MAGIC) for central collision events in 16 O + Pb and 32 S + Pb interactions. Charge-sign clustering is observed in most of the fully-analyzed events. A statistical 'run-test' is performed for each measured event, which shows significant deviation from a Gaussian distribution (0,1) expected for random-charge distribution. Candidates of charge clusters have 5 - 10 multiplicity of like-sign particles, and are often accompanied by opposite-sign clusters. Observed clustering of identical charges is more significant in the fragmentation region than in the central region. Two-particle Bose-Einstein interference and other effects are discussed for the run-test examination. (author)
5. Modulated charge injection in p-type dye-sensitized solar cells using fluorene-based light absorbers.
Science.gov (United States)
Liu, Zonghao; Xiong, Dehua; Xu, Xiaobao; Arooj, Qudsia; Wang, Huan; Yin, Liyuan; Li, Wenhui; Wu, Huaizhi; Zhao, Zhixin; Chen, Wei; Wang, Mingkui; Wang, Feng; Cheng, Yi-Bing; He, Hongshan
2014-03-12
In this study, new pull-push arylamine-fluorene based organic dyes zzx-op1, zzx-op2, and zzx-op3 have been designed and synthesized for p-type dye-sensitized solar cells (p-DSCs). In zzx-op1, a di(p-carboxyphenyl)amine (DCPA) was used as an electron donor, a perylenemonoimide (PMID) as an electron acceptor, and a fluorene (FLU) unit with two aliphatic hexyl chains as a π-conjugated linker. In zzx-op2 and zzx-op3, a 3,4-ethylenedioxythiophene (EDOT) and a thiophene were inserted consecutively between PMID and FLU to tune the energy levels of the frontier molecular orbitals of the dyes. The structural modification broadened the spectral coverage from an onset of 700 nm for zzx-op1 to 750 nm for zzx-op3. The electron-rich EDOT and thiophene lifted up the HOMO (highest occupied molecular orbital) levels of zzx-op2 and zzx-op3, making their potential more negative than zzx-op1. When three dyes were employed in p-type DSCs with I(-)/I3(-) as a redox couple and NiO nanoparticles as hole materials, zzx-op1 exhibited impressive energy conversion efficiency of 0.184% with the open-circuit voltage (VOC) of 112 mV and the short-circuit current density (JSC) of 4.36 mA cm(-2) under AM 1.5G condition. Density functional theory calculations, transient photovoltage decay measurements, and electrochemical impedance spectroscopic studies revealed that zzx-op1 sensitized solar cell exhibited much higher charge injection efficiency (90.3%) than zzx-op2 (53.9%) and zzx-op3 (39.0%), indicating a trade-off between spectral broadening and electron injection driving force in p-type DSCs.
6. The charge-transfer property and the performance of dye-sensitized solar cells of nitrogen doped zinc oxide
Energy Technology Data Exchange (ETDEWEB)
Zhang Lingyun [Department of Chemistry, Harbin Institute of Technology, Harbin 150001 (China); School of Chemical Engineering, Northeast Dianli University, Jilin 132012 (China); Yang Yulin, E-mail: ylyang@hit.edu.cn [Department of Chemistry, Harbin Institute of Technology, Harbin 150001 (China); Fan Ruiqing, E-mail: fanruiqing@hit.edu.cn [Department of Chemistry, Harbin Institute of Technology, Harbin 150001 (China); Chen Haiyan [Department of Chemistry, Harbin Institute of Technology, Harbin 150001 (China); Jia Ruokun [School of Chemical Engineering, Northeast Dianli University, Jilin 132012 (China); Wang Yonghui [Faculty of Chemistry, Northeast Normal University, Changchun, Jilin 130024 (China); Ma Liqun; Wang Yazhen [School of Material Science of Engineering, Qiqihar University, Qiqihar 161006 (China)
2012-07-25
Highlights: Black-Right-Pointing-Pointer Two methods (the solution and annealing methods) are used to prepare nitrogen-doped ZnO. Black-Right-Pointing-Pointer The charge-transfer properties of N-doping ZnO are investigated. Black-Right-Pointing-Pointer The overall conversion efficiency of N-doped ZnO-based dye-sensitized solar cells is successfully improved by N doping. - Abstract: In this study two methods, namely the solution and annealing methods, were used to prepare nitrogen-doped ZnO. The X-ray photoelectron spectroscopy (XPS) was performed to identify the composition and chemical states of N-doped ZnO. The N doping by the solution method was found to effectively decrease the acceptor effects. Surface photovoltage measurements (SPS) revealed a redshift of the threshold wavelength for the N-doped ZnO. And the recombination of photoinduced electron-hole pairs in this semiconductor material was obviously suppressed. The N-doped ZnO (solution method) exhibits the best performances among all the materials, even superior to N-doped ZnO (annealing method). Its J{sub sc} and {eta} values (9.35 mA/cm{sup 2} and 2.64%) have enhanced by several times compared with un-doped ZnO (J{sub sc}, 2.85 mA/cm{sup 2}; {eta}, 0.67%). The overall conversion efficiency of ZnO-based dye-sensitized solar cells was successfully improved by the N doping.
7. Compact, Energy-Efficient High-Frequency Switched Capacitor Neural Stimulator With Active Charge Balancing.
Science.gov (United States)
Hsu, Wen-Yang; Schmid, Alexandre
2017-08-01
Safety and energy efficiency are two major concerns for implantable neural stimulators. This paper presents a novel high-frequency, switched capacitor (HFSC) stimulation and active charge balancing scheme, which achieves high energy efficiency and well-controlled stimulation charge in the presence of large electrode impedance variations. Furthermore, the HFSC can be implemented in a compact size without any external component to simultaneously enable multichannel stimulation by deploying multiple stimulators. The theoretical analysis shows significant benefits over the constant-current and voltage-mode stimulation methods. The proposed solution was fabricated using a 0.18 μm high-voltage technology, and occupies only 0.035 mm 2 for a single stimulator. The measurement result shows 50% peak energy efficiency and confirms the effectiveness of active charge balancing to prevent the electrode dissolution.
8. Highly sensitive electrochemical determination of 1-naphthol based on high-index facet SnO2 modified electrode
International Nuclear Information System (INIS)
Huang Xiaofeng; Zhao Guohua; Liu Meichuan; Li Fengting; Qiao Junlian; Zhao Sichen
2012-01-01
Highlights: ► It is the first time to employ high-index faceted SnO 2 in electrochemical analysis. ► High-index faceted SnO 2 has excellent electrochemical activity toward 1-naphthol. ► Highly sensitive determination of 1-naphthol is realized on high-index faceted SnO 2 . ► The detection limit of 1-naphthol is as low as 5 nM on high-index faceted SnO 2 . ► Electro-oxidation kinetics for 1-napthol on the novel electrode is discussed. - Abstract: SnO 2 nanooctahedron with {2 2 1} high-index facet (HIF) was synthesized by a simple hydrothermal method, and was firstly employed to sensitive electrochemical sensing of a typical organic pollutant, 1-naphthol (1-NAP). The constructed HIF SnO 2 modified glassy carbon electrode (HIF SnO 2 /GCE) possessed advantages of large effective electrode area, high electron transfer rate, and low charge transfer resistance. These improved electrochemical properties allowed the high electrocatalytic performance, high effective active sites and high adsorption capacity of 1-NAP on HIF SnO 2 /GCE. Cyclic voltammetry (CV) results showed that the electrochemical oxidation of 1-NAP obeyed a two-electron transfer process and the electrode reaction was under diffusion control on HIF SnO 2 /GCE. By adopting differential pulse voltammetry (DPV), electrochemical detection of 1-NAP was conducted on HIF SnO 2 /GCE with a limit of detection as low as 5 nM, which was relatively low compared to the literatures. The electrode also illustrated good stability in comparison with those reported value. Satisfactory results were obtained with average recoveries in the range of 99.7–103.6% in the real water sample detection. A promising device for the electrochemical detection of 1-NAP with high sensitivity has therefore been provided.
9. High Sensitivity and High Detection Specificity of Gold-Nanoparticle-Grafted Nanostructured Silicon Mass Spectrometry for Glucose Analysis.
Science.gov (United States)
Tsao, Chia-Wen; Yang, Zhi-Jie
2015-10-14
Desorption/ionization on silicon (DIOS) is a high-performance matrix-free mass spectrometry (MS) analysis method that involves using silicon nanostructures as a matrix for MS desorption/ionization. In this study, gold nanoparticles grafted onto a nanostructured silicon (AuNPs-nSi) surface were demonstrated as a DIOS-MS analysis approach with high sensitivity and high detection specificity for glucose detection. A glucose sample deposited on the AuNPs-nSi surface was directly catalyzed to negatively charged gluconic acid molecules on a single AuNPs-nSi chip for MS analysis. The AuNPs-nSi surface was fabricated using two electroless deposition steps and one electroless etching step. The effects of the electroless fabrication parameters on the glucose detection efficiency were evaluated. Practical application of AuNPs-nSi MS glucose analysis in urine samples was also demonstrated in this study.
10. Development of High Sensitivity Nuclear Emulsion and Fine Grained Emulsion
Science.gov (United States)
Kawahara, H.; Asada, T.; Naka, T.; Naganawa, N.; Kuwabara, K.; Nakamura, M.
2014-08-01
Nuclear emulsion is a particle detector having high spacial resolution and angular resolution. It became useful for large statistics experiment thanks to the development of automatic scanning system. In 2010, a facility for emulsion production was introduced and R&D of nuclear emulsion began at Nagoya university. In this paper, we present results of development of the high sensitivity emulsion and fine grained emulsion for dark matter search experiment. Improvement of sensitivity is achieved by raising density of silver halide crystals and doping well-adjusted amount of chemicals. Production of fine grained emulsion was difficult because of unexpected crystal condensation. By mixing polyvinyl alcohol (PVA) to gelatin as a binder, we succeeded in making a stable fine grained emulsion.
11. Development of High Sensitivity Nuclear Emulsion and Fine Grained Emulsion
International Nuclear Information System (INIS)
Kawahara, H.; Asada, T.; Naka, T.; Naganawa, N.; Kuwabara, K.; Nakamura, M.
2014-01-01
Nuclear emulsion is a particle detector having high spacial resolution and angular resolution. It became useful for large statistics experiment thanks to the development of automatic scanning system. In 2010, a facility for emulsion production was introduced and R and D of nuclear emulsion began at Nagoya university. In this paper, we present results of development of the high sensitivity emulsion and fine grained emulsion for dark matter search experiment. Improvement of sensitivity is achieved by raising density of silver halide crystals and doping well-adjusted amount of chemicals. Production of fine grained emulsion was difficult because of unexpected crystal condensation. By mixing polyvinyl alcohol (PVA) to gelatin as a binder, we succeeded in making a stable fine grained emulsion
12. Online high sensitivity measurement system for transuranic aerosols
International Nuclear Information System (INIS)
Kordas, J.F.; Phelps, P.L.
1976-01-01
A measurement system for transuranic aerosols has been designed that will be able to withstand the corrosive nature of stack effluents and yet have extremely high sensitivity. It will be capable of measuring 1 maximum permissible concentration (MPC) of plutonium or americium in 30 minutes with a fractional standard deviation of less than 0.33. Background resulting from 218 Po is eliminated by alpha energy discrimination and a decay scheme analysis. A microprocessor controls all data acquisition, data reduction, and instrument calibration
13. High-k shallow traps observed by charge pumping with varying discharging times
International Nuclear Information System (INIS)
Ho, Szu-Han; Chen, Ching-En; Tseng, Tseung-Yuen; Chang, Ting-Chang; Lu, Ying-Hsin; Lo, Wen-Hung; Tsai, Jyun-Yu; Liu, Kuan-Ju; Wang, Bin-Wei; Cao, Xi-Xin; Chen, Hua-Mao; Cheng, Osbert; Huang, Cheng-Tung; Chen, Tsai-Fu
2013-01-01
In this paper, we investigate the influence of falling time and base level time on high-k bulk shallow traps measured by charge pumping technique in n-channel metal-oxide-semiconductor field-effect transistors with HfO 2 /metal gate stacks. N T -V high level characteristic curves with different duty ratios indicate that the electron detrapping time dominates the value of N T for extra contribution of I cp traps. N T is the number of traps, and I cp is charge pumping current. By fitting discharge formula at different temperatures, the results show that extra contribution of I cp traps at high voltage are in fact high-k bulk shallow traps. This is also verified through a comparison of different interlayer thicknesses and different Ti x N 1−x metal gate concentrations. Next, N T -V high level characteristic curves with different falling times (t falling time ) and base level times (t base level ) show that extra contribution of I cp traps decrease with an increase in t falling time . By fitting discharge formula for different t falling time , the results show that electrons trapped in high-k bulk shallow traps first discharge to the channel and then to source and drain during t falling time . This current cannot be measured by the charge pumping technique. Subsequent measurements of N T by charge pumping technique at t base level reveal a remainder of electrons trapped in high-k bulk shallow traps
14. Interaction of slow highly-charged ions with metals and insulators
International Nuclear Information System (INIS)
Yamazaki, Y.
2007-01-01
Interaction of slow highly charged ions with insulator as well as metallic surfaces is discussed. In addition to the usual flat surface targets, studies with thin foils having a multitude of straight holes of ∼100 nm in diameter (micro-capillary foil) are introduced, which provide various unique information on the above surface interaction. In the case of an insulator micro-capillary foil, a so-called guiding effect was observed, where slow highly charged ions can transmit through the capillary tunnel keeping their initial charge state even when the capillary axis is tilted against the incident beam. A similar guiding effect has recently been found for slow highly-charged ions transmitted through a single tapered glass capillary. In both cases, the guiding effects are expected to be governed by a self-organized charging and discharging of the inner-wall of the insulator capillary. One of the prominent features of this guiding effect with the tapered capillary is the formation of a nano-size beam, which can be applied in various fields of science including surface nano-modification/analysis, nano-surgery of living cells, etc
15. Observation of visible and uv magnetic dipole transitions in highly charged xenon and barium
International Nuclear Information System (INIS)
Morgan, C.A.; Serpa, F.G.; Takacs, E.; Meyer, E.S.; Gillaspy, J.D.; Sugar, J.; Roberts, J.R.; Brown, C.M.; Feldman, U.
1995-01-01
We have observed an unusual transition which is predicted to result in visible and near-uv emission from very highly charged titaniumlike ions spanning the entire upper half of the periodic table. Measurements of the wavelengths of the 3d 4 D 2 - 5 D 3 transitions in Ba +34 and Xe +32 are in surprisingly poor agreement with ab initio calculations. This work was carried out in an electron beam ion trap and demonstrates that such a device can be an important tool for visible spectroscopy of highly charged ions
16. Possible Diamond-Like Nanoscale Structures Induced by Slow Highly-Charged Ions on Graphite (HOPG)
Energy Technology Data Exchange (ETDEWEB)
Sideras-Haddad, E.; Schenkel, T.; Shrivastava, S.; Makgato, T.; Batra, A.; Weis, C. D.; Persaud, A.; Erasmus, R.; Mwakikunga, B.
2009-01-06
The interaction between slow highly-charged ions (SHCI) of different charge states from an electron-beam ion trap and highly oriented pyrolytic graphite (HOPG) surfaces is studied in terms of modification of electronic states at single-ion impact nanosizeareas. Results are presented from AFM/STM analysis of the induced-surface topological features combined with Raman spectroscopy. I-V characteristics for a number of different impact regions were measured with STM and the results argue for possible formation of diamond-like nanoscale structures at the impact sites.
17. Modelling of prompt losses of high energy charged particles in Tokamaks
International Nuclear Information System (INIS)
Dillner, Oe.; Anderson, D.; Hamnen, H.; Lisak, M.
1990-01-01
A simple analytical expression for the total prompt loss fraction of high energy charged particles in an axisymmetric Tokamak is derived. The results are compared with predictions obtained from numerical simulations and show good agreement. An application is made to sawtooth induced changes in the losses of fusion generated high energy charged particles. Particular emphasis is given to the importance of sawtooth induced profile changes of the background ion densities and temperature as well as to redistribution of particles which have accumulated during the sawtooth rise but are being lost by redistribution at the sawtooth crash. (au)
18. X-ray emission in slow highly charged ion-surface collisions
International Nuclear Information System (INIS)
Watanabe, H; Abe, T; Fujita, Y; Sun, J; Takahashi, S; Tona, M; Yoshiyasu, N; Nakamura, N; Sakurai, M; Yamada, C; Ohtani, S
2007-01-01
X-rays emitted in the collisions of highly charged ions with a surface have been measured to investigate dissipation schemes of their potential energies. While 8.1% of the potential energy was dissipated in the collisions of He-like I ions with a W surface, 29.1% has been dissipated in the case of He-like Bi ions. The x-ray emissions play significant roles in the dissipation of the potential energies in the interaction of highly charged heavy ions with the surface
19. Improvement of highly charged ion production in the ECR source of heavy ions
International Nuclear Information System (INIS)
Shirkov, G.D.
1996-01-01
Some physical limitations of the highly charged ion production in the ECR source are analyzed in this report. A few possible ways to improve the output of highly charged ions from the ECR source for heavy ions are proposed. A new library of computer codes for the numerical simulation of heavy ion production in the ECR ion source is used to examine these ways to improve the ECR source operation according to the CERN program of heavy ion acceleration. copyright 1996 American Institute of Physics
20. Generation of annular, high-charge electron beams at the Argonne wakefield accelerator
Science.gov (United States)
Wisniewski, E. E.; Li, C.; Gai, W.; Power, J.
2013-01-01
We present and discuss the results from the experimental generation of high-charge annular(ring-shaped)electron beams at the Argonne Wakefield Accelerator (AWA). These beams were produced by using laser masks to project annular laser profiles of various inner and outer diameters onto the photocathode of an RF gun. The ring beam is accelerated to 15 MeV, then it is imaged by means of solenoid lenses. Transverse profiles are compared for different solenoid settings. Discussion includes a comparison with Parmela simulations, some applications of high-charge ring beams,and an outline of a planned extension of this study.
1. Possibility of resonant capture of antiprotons by highly charged hydrogenlike ions
International Nuclear Information System (INIS)
Genkin, M.; Lindroth, E.
2009-01-01
Recently, an experimental setup was proposed by Lapierre et al. which would allow antiprotons and highly charged ions to collide repeatedly in an electron beam ion trap (EBIT) due to a nested trap configuration. As mentioned by the authors, such a setup may open the possibility to study antiproton capture into well-defined states through a resonant process which involves simultaneous electron excitation. In the present work, we give some theoretical estimations of the feasibility of that process. It appears that the exotic dielectronic-like process of resonant anti-proton capture in highly charged ions does not seem to be completely out of reach
2. Emulsifier-free emulsion polymerization produces highly charged, monodisperse particles for near infrared photonic crystals.
Science.gov (United States)
Reese, Chad E; Asher, Sanford A
2002-04-01
We have developed emulsifier-free, emulsion polymerization recipes for the synthesis of highly charged, monodisperse latex particles of diameters between 500 and 1100 nm. These latexes consist of poly[styrene-(co-2-hydroxyethyl methacrylate)] spherical particles whose surfaces are functionalized with sulfate and carboxylic acid groups. These highly charged, monodisperse particles readily self-assemble into robust, three-dimensionally ordered crystalline colloidal array photonic crystals that Bragg diffract light in the near infrared spectral region. By altering the particle number density, the diffraction wavelength can be tuned from approximately 1000 to approximately 4000 nm.
3. Generation of annular, high-charge electron beams at the Argonne wakefield accelerator
Science.gov (United States)
Wisniewski, E. E.; Li, C.; Gai, W.; Power, J.
2012-12-01
We present and discuss the results from the experimental generation of high-charge annular(ring-shaped)electron beams at the Argonne Wakefield Accelerator (AWA). These beams were produced by using laser masks to project annular laser profiles of various inner and outer diameters onto the photocathode of an RF gun. The ring beam is accelerated to 15 MeV, then it is imaged by means of solenoid lenses. Transverse profiles are compared for different solenoid settings. Discussion includes a comparison with Parmela simulations, some applications of high-charge ring beams,and an outline of a planned extension of this study.
4. Recent trends in high spin sensitivity magnetic resonance
Science.gov (United States)
Blank, Aharon; Twig, Ygal; Ishay, Yakir
2017-07-01
new ideas, show how these limiting factors can be mitigated to significantly improve the sensitivity of induction detection. Finally, we outline some directions for the possible applications of high-sensitivity induction detection in the field of electron spin resonance.
5. High-sensitivity bend angle measurements using optical fiber gratings.
Science.gov (United States)
Rauf, Abdul; Zhao, Jianlin; Jiang, Biqiang
2013-07-20
We present a high-sensitivity and more flexible bend measurement method, which is based on the coupling of core mode to the cladding modes at the bending region in concatenation with optical fiber grating serving as band reflector. The characteristics of a bend sensing arm composed of bending region and optical fiber grating is examined for different configurations including single fiber Bragg grating (FBG), chirped FBG (CFBG), and double FBGs. The bend loss curves for coated, stripped, and etched sections of fiber in the bending region with FBG, CFBG, and double FBG are obtained experimentally. The effect of separation between bending region and optical fiber grating on loss is measured. The loss responses for single FBG and CFBG configurations are compared to discover the effectiveness for practical applications. It is demonstrated that the sensitivity of the double FBG scheme is twice that of the single FBG and CFBG configurations, and hence acts as sensitivity multiplier. The bend loss response for different fiber diameters obtained through etching in 40% hydrofluoric acid, is measured in double FBG scheme that resulted in a significant increase in the sensitivity, and reduction of dead-zone.
6. Physical mechanisms leading to high currents of highly charged ions in laser-driven ion sources
International Nuclear Information System (INIS)
Haseroth, Helmut; Hora, Heinrich; Regensburg Inst. of Tech.
1996-01-01
Heavy ion sources for the big accelerators, for example, the LHC, require considerably more ions per pulse during a short time than the best developed classical ion source, the electron cyclotron resonance (ECR) provides; thus an alternative ion source is needed. This can be expected from laser-produced plasmas, where dramatically new types of ion generation have been observed. Experiments with rather modest lasers have confirmed operation with one million pulses of 1 Hz, and 10 11 C 4+ ions per pulse reached 2 GeV/u in the Dubna synchrotron. We review here the complexities of laser-plasma interactions to underline the unique and extraordinary possibilities that the laser ion source offers. The complexities are elaborated with respect to keV and MeV ion generation, nonlinear (ponderomotive) forces, self-focusing, resonances and ''hot'' electrons, parametric instabilities, double-layer effects, and the few ps stochastic pulsation (stuttering). Recent experiments with the laser ion source have been analyzed to distinguish between the ps and ns interaction, and it was discovered that one mechanism of highly charged ion generation is the electron impact ionization (EII) mechanism, similar to the ECR, but with so much higher plasma densities that the required very large number of ions per pulse are produced. (author)
7. Physical mechanisms leading to high currents of highly charged ions in laser-driven ion sources
Energy Technology Data Exchange (ETDEWEB)
Haseroth, Helmut [European Organization for Nuclear Research, Geneva (Switzerland); Hora, Heinrich [New South Wales Univ., Kensington, NSW (Australia)]|[Regensburg Inst. of Tech. (Germany). Anwenderzentrum
1996-12-31
Heavy ion sources for the big accelerators, for example, the LHC, require considerably more ions per pulse during a short time than the best developed classical ion source, the electron cyclotron resonance (ECR) provides; thus an alternative ion source is needed. This can be expected from laser-produced plasmas, where dramatically new types of ion generation have been observed. Experiments with rather modest lasers have confirmed operation with one million pulses of 1 Hz, and 10{sup 11} C{sup 4+} ions per pulse reached 2 GeV/u in the Dubna synchrotron. We review here the complexities of laser-plasma interactions to underline the unique and extraordinary possibilities that the laser ion source offers. The complexities are elaborated with respect to keV and MeV ion generation, nonlinear (ponderomotive) forces, self-focusing, resonances and hot electrons, parametric instabilities, double-layer effects, and the few ps stochastic pulsation (stuttering). Recent experiments with the laser ion source have been analyzed to distinguish between the ps and ns interaction, and it was discovered that one mechanism of highly charged ion generation is the electron impact ionization (EII) mechanism, similar to the ECR, but with so much higher plasma densities that the required very large number of ions per pulse are produced. (author).
8. Penning traps with unitary architecture for storage of highly charged ions
International Nuclear Information System (INIS)
Tan, Joseph N.; Guise, Nicholas D.; Brewer, Samuel M.
2012-01-01
Penning traps are made extremely compact by embedding rare-earth permanent magnets in the electrode structure. Axially-oriented NdFeB magnets are used in unitary architectures that couple the electric and magnetic components into an integrated structure. We have constructed a two-magnet Penning trap with radial access to enable the use of laser or atomic beams, as well as the collection of light. An experimental apparatus equipped with ion optics is installed at the NIST electron beam ion trap (EBIT) facility, constrained to fit within 1 meter at the end of a horizontal beamline for transporting highly charged ions. Highly charged ions of neon and argon, extracted with initial energies up to 4000 eV per unit charge, are captured and stored to study the confinement properties of a one-magnet trap and a two-magnet trap. Design considerations and some test results are discussed.
9. Penning traps with unitary architecture for storage of highly charged ions.
Science.gov (United States)
Tan, Joseph N; Brewer, Samuel M; Guise, Nicholas D
2012-02-01
Penning traps are made extremely compact by embedding rare-earth permanent magnets in the electrode structure. Axially-oriented NdFeB magnets are used in unitary architectures that couple the electric and magnetic components into an integrated structure. We have constructed a two-magnet Penning trap with radial access to enable the use of laser or atomic beams, as well as the collection of light. An experimental apparatus equipped with ion optics is installed at the NIST electron beam ion trap (EBIT) facility, constrained to fit within 1 meter at the end of a horizontal beamline for transporting highly charged ions. Highly charged ions of neon and argon, extracted with initial energies up to 4000 eV per unit charge, are captured and stored to study the confinement properties of a one-magnet trap and a two-magnet trap. Design considerations and some test results are discussed.
10. Aberrations due to solenoid focusing of a multiply charged high-current ion beam
CERN Document Server
Grégoire, G; Lisi, N; Schnuriger, J C; Scrivens, R; Tambini, J
2000-01-01
At the output of a laser ion source, a high current of highly charged ions with a large range of charge states is available. The focusing of such a beam by magnetic elements causes a nonlinear space-charge field to develop which can induce large aberrations and emittance growth in the beam. Simulation of the beam from the CERN laser ion source will be presented for an ideal magnetic and electrostatic system using a radially symmetric model. In addition, the three dimensional software KOBRA3 is used for the simulation of the solenoid line. The results of these simulations will be compared with experiments performed on the CERN laser ion source with solenoids (resulting in a hollow beam) and a series of gridded electrostatic lenses. (5 refs).
11. The longitudinal space charge problem in the high current linear proton accelerators
International Nuclear Information System (INIS)
Lustfeld, H.
1984-01-01
In a linear proton accelerator peak currents of 200 mA lead to high space charge densities and the resultant space charge forces reduce the effective focussing considerably. In particular the longitudinal focussing is affected. A new concept based on linear theory is proposed that restricts the influence of the space charge forces on the longitudinal focussing by increasing a, the mean transverse bunch radius, as a proportional(βγ)sup(3/8). This concept is compared with other concepts for the Alvarez (1 MeV - 100 MeV) and for the high energy part (100 MeV - 1100 MeV) of the SNQ linear accelerator. (orig.)
12. Novel Highly Sensitive Protein Sensors Based on Tapered Optical Fibres Modified with Au-Based Nanocoatings
Directory of Open Access Journals (Sweden)
Aitor Urrutia
2016-01-01
Full Text Available Novel protein sensors based on tapered optical fibres modified with Au coatings deposited using two different procedures are proposed. Au-based coatings are deposited onto a nonadiabatic tapered optical fibre using (i a novel facile method composed of layer-by-layer deposition consisting of polycation (poly(allylamine hydrochloride, PAH and negatively charged SiO2 nanoparticles (NPs followed by the deposition of the charged Au NPs and (ii the sputtering technique. The Au NPs and Au thin film surfaces are then modified with biotin in order to bind streptavidin (SV molecules and detect them. The sensing principle is based on the sensitivity of the transmission spectrum of the device to changes in the refractive index of the coatings induced by the SV binding to the biotin. Both sensors showed high sensitivity to SV, with the lowest measured concentration levels below 2.5 nM. The calculated binding constant for the biotin-SV pair was 2.2×10-11 M−1 when a tapered fibre modified with the LbL method was used, with a limit of detection (LoD of 271 pM. The sensor formed using sputtering had a binding constant of 1.01×10-10 M−1 with a LoD of 806 pM. These new structures and their simple fabrication technique could be used to develop other biosensors.
13. Quantum Dot-Fullerene Based Molecular Beacon Nanosensors for Rapid, Highly Sensitive Nucleic Acid Detection.
Science.gov (United States)
Liu, Ye; Kannegulla, Akash; Wu, Bo; Cheng, Li-Jing
2018-05-15
Spherical fullerene (C 60 ) can quench the fluorescence of a quantum dot (QD) through energy transfer and charge transfer processes, with the quenching efficiency regulated by the number of proximate C 60 on each QD. With the quenching property and its small size compared with other nanoparticle-based quenchers, it is advantageous to group a QD reporter and multiple C 60 -labeled oligonucleotide probes to construct a molecular beacon (MB) probe for sensitive, robust nucleic acid detection. We demonstrated a rapid, high-sensitivity DNA detection method using the nanosensors composed of QD-C 60 based MBs carried by magnetic nanoparticles (MNPs). The assay was accelerated by first dispersing the nanosensors in analytes for highly efficient DNA capture resulting from short-distance 3-dimensional diffusion of targets to the sensor surface and then concentrating the nanosensors to a substrate by magnetic force to amplify the fluorescence signal for target quantification. The enhanced mass transport enabled a rapid detection (< 10 min) with a small sample volume (1-10 µl). The high signal-to-noise ratio produced by the QD-C 60 pairs and magnetic concentration yielded a detection limit of 100 fM (~106 target DNA copies for a 10 µl analyte). The rapid, sensitive, label-free detection method will benefit the applications in point-of-care molecular diagnostic technologies.
14. Towards highly sensitive strain sensing based on nanostructured materials
International Nuclear Information System (INIS)
Dao, Dzung Viet; Nakamura, Koichi; Sugiyama, Susumu; Bui, Tung Thanh; Dau, Van Thanh; Yamada, Takeo; Hata, Kenji
2010-01-01
This paper presents our recent theoretical and experimental study of piezo-effects in nanostructured materials for highly sensitive, high resolution mechanical sensors. The piezo-effects presented here include the piezoresistive effect in a silicon nanowire (SiNW) and single wall carbon nanotube (SWCNT) thin film, as well as the piezo-optic effect in a Si photonic crystal (PhC) nanocavity. Firstly, the electronic energy band structure of the silicon nanostructure is discussed and simulated by using the First-Principles Calculations method. The result showed a remarkably different energy band structure compared with that of bulk silicon. This difference in the electronic state will result in different physical, chemical, and therefore, sensing properties of silicon nanostructures. The piezoresistive effects of SiNW and SWCNT thin film were investigated experimentally. We found that, when the width of ( 110 ) p-type SiNW decreases from 500 to 35 nm, the piezoresistive effect increases by more than 60%. The longitudinal piezoresistive coefficient of SWCNT thin film was measured to be twice that of bulk p-type silicon. Finally, theoretical investigations of the piezo-optic effect in a PhC nanocavity based on Finite Difference Time Domain (FDTD) showed extremely high resolution strain sensing. These nanostructures were fabricated based on top-down nanofabrication technology. The achievements of this work are significant for highly sensitive, high resolution and miniaturized mechanical sensors
15. Phase shift PWM with double two-switch bridge for high power capacitor charging
International Nuclear Information System (INIS)
Karandikar, U.S.; Singh, Yashpal; Thakurta, A.C.
2013-01-01
Pulse power supply systems working at higher voltage and high repetition rate demands for higher power from capacitor chargers. Capacitor charging requirement become more challenging in such cases. In pulse power circuits, energy storage capacitor should be charged to its desired voltage before the next switching occurs. It is discharged within a small time, delivering large pulse power. A capacitor charger has to work with wide load variation repeatedly. Many schemes are used for this purpose. The proposed scheme aims at reducing stresses on switches by reducing peak current and their evils. A high voltage power supply is designed for capacitor charging. The proposed scheme is based on a Phase-Shifted PWM without using any extra component to achieve soft switching. Indirect constant average current capacitor charging is achieved with a simple control scheme. A double two-switch bridge is proposed to enhance reliability. Power supply has been developed to charge a capacitor of 50 μF to 2.5 kV at 25 Hz. (author)
16. High-frequency asymptotics of the emission spectrum of moving charged particles in classical electrodynamics
International Nuclear Information System (INIS)
Abbasov, I.I.; Bolotovskij, B.M.; Davydov, V.A.
1986-01-01
Electromagnetic radiation appears as a result of a charged particle movement in free space and also in heterogeneous and non-stationary medium. The radiation spectrum depends on the charged particle motion law, as well as on the law of the medium property chage in space and time. The asymptotics of radiation spectrum, i.e. behaviour of spectral intensity at high frequencies, is studied. It is shown that if a charged particle moves along smooth trajectory or if the change in the medium properties takes place accordng to the law described by a smooth function, the radiation spectrum at high frequencies decreases according to exponential law. Thus, radiation spectrum of a charged particle moving along a smooth trajectory in the medium with gradual heterogeneity and (or) instability is rapidly cut, starting from a certain frequency value. The smooth trajectory means that the charge moves according to the law r = r(t), where vector-function r(t) is continuous with all its derivatives. In much the same way the medium with gradual heterogeneities (or with gradual instability) is described by the functions which are continuous with all their derivatives of any order. The method permitting to determine the upper boundary of radiation spectra is presented
17. Development of Discrete Power Supply with Charge Pump Method for High Powered Sonar System
Directory of Open Access Journals (Sweden)
Kristian Ismail
2012-07-01
Full Text Available Power supply is one of the electronic devices that can provide electric energy for electronic systems or other systems. There are several types of power supplies that can be applied depend on the requirement and functions. One example is the use of power supply for sonar systems. Sonar system is a device which can be used to detect a target under water. The sonar system is an electronic circuit that requires a power supply with specific characteristics when the sonar functions as a transmitter and a receiver in the specific span time (when on and the specific lag time (when off. This paper discusses the design of power supply for high-powered sonar systems with discrete methods in which high power supply is only applied when the acoustic waves radiated under water. Charge pump was used to get the appropriate output voltage from lower input voltage. Charge pump utilized a combination of series and parallel connections of capacitors. The working mode of this power supply used the lag time as the calculation of time to charge charge pump capacitors in parallel while the span time was used for the calculation of discharging the charge pump capacitors in series.
18. Production of highly charged ion beams from electron cyclotron resonance ion sources (invited)
International Nuclear Information System (INIS)
Xie, Z.Q.
1998-01-01
Electron cyclotron resonance ion source (ECRIS) development has progressed with multiple-frequency plasma heating, higher mirror magnetic fields, and better technique to provide extra cold electrons. Such techniques greatly enhance the production of highly charged ions from ECRISs. So far at continuous wave (CW) mode operation, up to 300 eμA of O 7+ and 1.15 emA of O 6+ , more than 100 eμA of intermediate heavy ions for charge states up to Ar 13+ , Ca 13+ , Fe 13+ , Co 14+ , and Kr 18+ , and tens of eμA of heavy ions with charge states to Kr 26+ , Xe 28+ , Au 35+ , Bi 34+ , and U 34+ were produced from ECRISs. At an intensity of at least 1 eμA, the maximum charge state available for the heavy ions are Xe 36+ , Au 46+ , Bi 47+ , and U 48+ . An order of magnitude enhancement for fully stripped argon ions (I≥60enA) were also achieved. This article will review the ECR ion source progress and discuss key requirement for ECRISs to produce the highly charged ion beams. copyright 1998 American Institute of Physics
19. EBIT spectroscopy of highly charged heavy ions relevant to hot plasmas
Science.gov (United States)
2013-05-01
An electron beam ion trap (EBIT) is a versatile device for studying highly charged ions. We have been using two types of EBITs for the spectroscopic studies of highly charged ions. One is a high-energy device called the Tokyo-EBIT, and another is a compact low-energy device called CoBIT. Complementary use of them enables us to obtain spectroscopic data for ions over a wide charge-state range interacting with electrons over a wide energy range. In this talk, we present EBIT spectra of highly charged ions for tungsten, iron, bismuth, etc., which are relevant to hot plasmas. Tungsten is considered to be the main impurity in the ITER (the next generation nuclear fusion reactor) plasma, and thus its emission lines are important for diagnosing and controlling the ITER plasma. We have observed many previously unreported lines to supply the lack of spectroscopic data of tungsten ions. Iron is one of the main components of the solar corona, and its spectra are used to diagnose temperature, density, etc. The diagnostics is usually done by comparing observed spectra with model calculations. An EBIT can provide spectra under a well-defined condition; they are thus useful to test the model calculations. Laser-produced bismuth plasma is one of the candidates for a soft x-ray source in the water window region. An EBIT has a narrow charge state distribution; it is thus useful to disentangle the spectra of laser-produced plasma containing ions with a wide charge-state range. Performed with the support and under the auspices of the NIFS Collaboration Research program (NIFS09KOAJ003) and JSPS KAKENHI Number 23246165, and partly supported by the JSPS-NRF-NSFC A3 Foresight Program in the field of Plasma Physics.
20. Apolipoprotein E expression and behavioral toxicity of high charge, high energy (HZE) particle radiation
Science.gov (United States)
Higuchi, Yoshinori; Nelson, Gregory A.; Vazquez, Marcelo; Laskowitz, Daniel T.; Slater, James M.; Pearlstein, Robert D.
2002-01-01
1. Apolipoprotein E expression and behavioral toxicity of high charge, high energy (HZE) particle radiation
International Nuclear Information System (INIS)
Higuchi, Yoshinori; Nelson, G.A.; Slater, J.M.; Pearlstein, R.D.; Laskowitz, D.T.
2002-01-01
2. Apolipoprotein E expression and behavioral toxicity of high charge, high energy (HZE) particle radiation
Energy Technology Data Exchange (ETDEWEB)
Higuchi, Yoshinori; Nelson, G.A.; Slater, J.M.; Pearlstein, R.D. [Loma Linda Univ., CA (United States). Medical Center; Vazquez, M. [Brookhaven National Lab., Upton, NY (United States); Laskowitz, D.T. [Duke Univ., Durham, NC (United States). Medical Center
2002-12-01
3. High sensitivity tests of the standard model for electroweak interactions
International Nuclear Information System (INIS)
Koetke, D.D.
1992-01-01
The work done on this project was focussed mainly on LAMPF experiment E969 known as the MEGA experiment, a high sensitivity search for the lepton family number violating decay μ → eγ to a sensitivity which, measured in terms of the branching ratio, BR = [μ→eγ]/[μ→e ν μ ν e ] ∼10 -13 is over two orders of magnitude better than previously reported values. The work done on MEGA during this period was divided between that done at Valparaiso University and that done at LAMPF. In addition, some contributions were made to a proposal to the LAMPF PAC to perform a precision measurement of the Michel ρ parameter, described below
4. High sensitivity tests of the standard model for electroweak interactions
International Nuclear Information System (INIS)
1994-01-01
The work done on this project focused on two LAMPF experiments. The MEGA experiment is a high-sensitivity search for the lepton family number violating decay μ → eγ to a sensitivity which, measured in terms of the branching ratio, BR = [μ → eγ]/[μ eν μ ν e ] ∼ 10 -13 , will be over two orders of magnitude better than previously reported values. The second is a precision measurement of the Michel ρ parameter from the positron energy spectrum of μ → eν μ ν e to test the predictions V-A theory of weak interactions. In this experiment the uncertainty in the measurement of the Michel ρ parameter is expected to be a factor of three lower than the present reported value. The detectors are operational, and data taking has begun
5. High sensitivity tests of the standard model for electroweak interactions
International Nuclear Information System (INIS)
Koetke, D.D.; Manweiler, R.W.; Shirvel Stanislaus, T.D.
1993-01-01
The work done on this project was focused on two LAMPF experiments. The MEGA experiment, a high-sensitivity search for the lepton-family-number-violating decay μ → e γ to a sensitivity which, measured in terms of the branching ratio, BR = [μ → e γ]/[μ → ev μ v e ] ∼ 10 -13 , is over two orders of magnitude better than previously reported values. The second is a precision measurement of the Michel ρ parameter from the positron energy spectrum of μ → ev μ v e to test the V-A theory of weak interactions. The uncertainty in the measurement of the Michel ρ parameter is expected to be a factor of three lower than the present reported value
6. High sensitive quench detection method using an integrated test wire
International Nuclear Information System (INIS)
Fevrier, A.; Tavergnier, J.P.; Nithart, H.; Kiblaire, M.; Duchateau, J.L.
1981-01-01
A high sensitive quench detection method which works even in the presence of an external perturbing magnetic field is reported. The quench signal is obtained from the difference in voltages at the superconducting winding terminals and at the terminals at a secondary winding strongly coupled to the primary. The secondary winding could consist of a ''zero-current strand'' of the superconducting cable not connected to one of the winding terminals or an integrated normal test wire inside the superconducting cable. Experimental results on quench detection obtained by this method are described. It is shown that the integrated test wire method leads to efficient and sensitive quench detection, especially in the presence of an external perturbing magnetic field
7. Development of miniature γ dose rate monitor with high sensitivity
International Nuclear Information System (INIS)
Shi Huilu; Tuo Xianguo; Xi Dashun; Tang Rong; Mu Keliang; Yang Jianbo
2009-01-01
This paper introduces a miniature γ dose rate monitor with high sensitivity which design based on single chip microcomputer, it can continue monitoring γ dose rate and then choose wire or wireless communications to sent the monitoring data to host according to the actual conditions. It has two kinds of power supply system, AC power supply system and battery which can be chose by concrete circumstances. The design idea and implementation technology of hardware and software and the system structure of the monitor are detailed illustrated in this paper. The experimental results show that measurable range is 0.1 mR/h-200 mR/h, the sensitivity of γ is 90 cps/mR/h, dead time below 200 us, error of stability below ±10%. (authors)
8. Polymer-Particle Pressure-Sensitive Paint with High Photostability
Directory of Open Access Journals (Sweden)
Yu Matsuda
2016-04-01
Full Text Available We propose a novel fast-responding and paintable pressure-sensitive paint (PSP based on polymer particles, i.e. polymer-particle (pp-PSP. As a fast-responding PSP, polymer-ceramic (PC-PSP is widely studied. Since PC-PSP generally consists of titanium (IV oxide (TiO2 particles, a large reduction in the luminescent intensity will occur due to the photocatalytic action of TiO2. We propose the usage of polymer particles instead of TiO2 particles to prevent the reduction in the luminescent intensity. Here, we fabricate pp-PSP based on the polystyrene particle with a diameter of 1 μm, and investigate the pressure- and temperature-sensitives, the response time, and the photostability. The performances of pp-PSP are compared with those of PC-PSP, indicating the high photostability with the other characteristics comparable to PC-PSP.
9. Classical/quantum correspondence in state selective charge transfer and excitation reactions involving highly charged ions and hydrogen
International Nuclear Information System (INIS)
Purkait, M
2009-01-01
State selective charge transfer and excitation cross sections for collisions of Ne q+ (q = 1-10) with atomic hydrogen are calculated within the framework of Classical Trajectory Monte Carlo (CTMC) method and Boundary Corrected Continuum Intermediate State (BCCIS) approximation.
10. Field test investigation of high sensitivity fiber optic seismic geophone
Science.gov (United States)
Wang, Meng; Min, Li; Zhang, Xiaolei; Zhang, Faxiang; Sun, Zhihui; Li, Shujuan; Wang, Chang; Zhao, Zhong; Hao, Guanghu
2017-10-01
Seismic reflection, whose measured signal is the artificial seismic waves ,is the most effective method and widely used in the geophysical prospecting. And this method can be used for exploration of oil, gas and coal. When a seismic wave travelling through the Earth encounters an interface between two materials with different acoustic impedances, some of the wave energy will reflect off the interface and some will refract through the interface. At its most basic, the seismic reflection technique consists of generating seismic waves and measuring the time taken for the waves to travel from the source, reflect off an interface and be detected by an array of geophones at the surface. Compared to traditional geophones such as electric, magnetic, mechanical and gas geophone, optical fiber geophones have many advantages. Optical fiber geophones can achieve sensing and signal transmission simultaneously. With the development of fiber grating sensor technology, fiber bragg grating (FBG) is being applied in seismic exploration and draws more and more attention to its advantage of anti-electromagnetic interference, high sensitivity and insensitivity to meteorological conditions. In this paper, we designed a high sensitivity geophone and tested its sensitivity, based on the theory of FBG sensing. The frequency response range is from 10 Hz to 100 Hz and the acceleration of the fiber optic seismic geophone is over 1000pm/g. sixteen-element fiber optic seismic geophone array system is presented and the field test is performed in Shengli oilfield of China. The field test shows that: (1) the fiber optic seismic geophone has a higher sensitivity than the traditional geophone between 1-100 Hz;(2) The low frequency reflection wave continuity of fiber Bragg grating geophone is better.
11. Sensitivity of the IceCube detector for ultra-high energy electron neutrino events
International Nuclear Information System (INIS)
Voigt, Bernhard
2008-01-01
IceCube is a neutrino telescope currently under construction in the glacial ice at South Pole. At the moment half of the detector is installed, when completed it will instrument 1 km 3 of ice providing a unique experimental setup to detect high energy neutrinos from astrophysical sources. In this work the sensitivity of the complete IceCube detector for a diffuse electron-neutrino flux is analyzed, with a focus on energies above 1 PeV. Emphasis is put on the correct simulation of the energy deposit of electromagnetic cascades from charged-current electron-neutrino interactions. Since existing parameterizations lack the description of suppression effects at high energies, a simulation of the energy deposit of electromagnetic cascades with energies above 1 PeV is developed, including cross sections which account for the LPM suppression of bremsstrahlung and pair creation. An attempt is made to reconstruct the direction of these elongated showers. The analysis presented here makes use of the full charge waveform recorded with the data acquisition system of the IceCube detector. It introduces new methods to discriminate efficiently between the background of atmospheric muons, including muon bundles, and cascade signal events from electron-neutrino interactions. Within one year of operation of the complete detector a sensitivity of 1.5.10 -8 E -2 GeVs -1 sr -1 cm -2 is reached, which is valid for a diffuse electron neutrino flux proportional to E -2 in the energy range from 16 TeV to 13 PeV. Sensitivity is defined as the upper limit that could be set in absence of a signal at 90% confidence level. Including all neutrino flavors in this analysis, an improvement of at least one order of magnitude is expected, reaching the anticipated performance of a diffuse muon analysis. (orig.)
12. Sensitivity of the IceCube detector for ultra-high energy electron neutrino events
Energy Technology Data Exchange (ETDEWEB)
Voigt, Bernhard
2008-07-16
IceCube is a neutrino telescope currently under construction in the glacial ice at South Pole. At the moment half of the detector is installed, when completed it will instrument 1 km{sup 3} of ice providing a unique experimental setup to detect high energy neutrinos from astrophysical sources. In this work the sensitivity of the complete IceCube detector for a diffuse electron-neutrino flux is analyzed, with a focus on energies above 1 PeV. Emphasis is put on the correct simulation of the energy deposit of electromagnetic cascades from charged-current electron-neutrino interactions. Since existing parameterizations lack the description of suppression effects at high energies, a simulation of the energy deposit of electromagnetic cascades with energies above 1 PeV is developed, including cross sections which account for the LPM suppression of bremsstrahlung and pair creation. An attempt is made to reconstruct the direction of these elongated showers. The analysis presented here makes use of the full charge waveform recorded with the data acquisition system of the IceCube detector. It introduces new methods to discriminate efficiently between the background of atmospheric muons, including muon bundles, and cascade signal events from electron-neutrino interactions. Within one year of operation of the complete detector a sensitivity of 1.5.10{sup -8}E{sup -2} GeVs{sup -1}sr{sup -1}cm{sup -2} is reached, which is valid for a diffuse electron neutrino flux proportional to E{sup -2} in the energy range from 16 TeV to 13 PeV. Sensitivity is defined as the upper limit that could be set in absence of a signal at 90% confidence level. Including all neutrino flavors in this analysis, an improvement of at least one order of magnitude is expected, reaching the anticipated performance of a diffuse muon analysis. (orig.)
13. Initial observations of high-charge, low-emittance electron beams at HIBAF (High Brightness Accelerator FEL)
Energy Technology Data Exchange (ETDEWEB)
Lumpkin, A.H.; Feldman, R.B.; Carsten, B.E.; Feldman, D.W.; Sheffield, R.L.; Stein, W.E.; Johnson, W.J.; Thode, L.E.; Bender, S.C.; Busch, G.E.
1990-01-01
We report our initial measurements of bright (high-charge, low-emittance) electron beams generated at the Los Alamos High Brightness Accelerator FEL (HIBAF) Facility. Normalized emittance values of less than 50 {pi} mm-mrad for charges ranging from 0.7 to 8.7 nC were obtained for single micropulses at a y-waist and at an energy of 14.7 MeV. These measurements were part of the commissioning campaign on the HIBAF photoelectric injector. Macropulse measurements have also been performed and are compared with PARMELA simulations. 5 refs., 8 figs., 3 tabs.
14. Highly sensitive detection of urinary cadmium to assess personal exposure
Energy Technology Data Exchange (ETDEWEB)
Argun, Avni A.; Banks, Ashley M.; Merlen, Gwendolynne; Tempelman, Linda A. [Giner, Inc., 89 Rumford Ave., Newton 02466, MA United States (United States); Becker, Michael F.; Schuelke, Thomas [Fraunhofer USA – CCL, 1449 Engineering Research Ct., East Lansing 48824, MI (United States); Dweik, Badawi M., E-mail: bdweik@ginerinc.com [Giner, Inc., 89 Rumford Ave., Newton 02466, MA United States (United States)
2013-04-22
Highlights: ► An electrochemical sensor capable of detecting cadmium at parts-per-billion levels in urine. ► A novel fabrication method for Boron-Doped Diamond (BDD) ultramicroelectrode (UME) arrays. ► Unique combination of BDD UME arrays and a differential pulse voltammetry algorithm. ► High sensitivity, high reproducibility, and very low noise levels. ► Opportunity for portable operation to assess on-site personal exposure. -- Abstract: A series of Boron-Doped Diamond (BDD) ultramicroelectrode arrays were fabricated and investigated for their performance as electrochemical sensors to detect trace level metals such as cadmium. The steady-state diffusion behavior of these sensors was validated using cyclic voltammetry followed by electrochemical detection of cadmium in water and in human urine to demonstrate high sensitivity (>200 μA ppb{sup −1} cm{sup −2}) and low background current (<4 nA). When an array of ultramicroelectrodes was positioned with optimal spacing, these BDD sensors showed a sigmoidal diffusion behavior. They also demonstrated high accuracy with linear dose dependence for quantification of cadmium in a certified reference river water sample from the U.S. National Institute of Standards and Technology (NIST) as well as in a human urine sample spiked with 0.25–1 ppb cadmium.
15. Secondary-electron yield from Au induced by highly charged Ta ions
Czech Academy of Sciences Publication Activity Database
Krása, Josef; Láska, Leoš; Stöckli, M. P.; Fry, D.
2001-01-01
Roč. 173, - (2001), s. 281-286 ISSN 0168-583X R&D Projects: GA AV ČR IAA1010819 Institutional research plan: CEZ:AV0Z1010914 Keywords : highly charged ion-surface interaction * ion-induced electron emission * angle impact effect Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.041, year: 2001
16. Simple heuristic derivation of some charge-transfer probabilities at asymptotically high incident velocities
International Nuclear Information System (INIS)
Spruch, L.; Shakeshaft, R.
1984-01-01
For asymptotically high incident velocities we provide simple, heuristic, almost classical, derivations of the cross section for forward charge transfer, and of the ratio of the cross section for capture to the elastic-scattering cross section for the projectile scattered through an angle close to π/3
17. Analysis and design of a charge pump circuit for high output current applications
NARCIS (Netherlands)
van Steenwijk, Gijs; van Steenwijk, Gijs; Hoen, Klaas; Hoen, Klaas; Wallinga, Hans
1993-01-01
A charge pump circuit has been developed that can deliver high currents even for a system supply voltage of 3 V. The circuit consists of capacitances, connected by MOS switches. The influence of the on-resistance of the switches on the circuit's output resistance has been analysed. The switches are
18. Spectroscopy of highly charged tungsten ions with Electron Beam Ion Traps
International Nuclear Information System (INIS)
Sakaue, Hiroyuki A.; Kato, Daiji; Morita, Shigeru; Murakami, Izumi; Yamamoto, Norimasa; Ohashi, Hayato; Yatsurugi, Junji; Nakamura, Nobuyuki
2013-01-01
We present spectra of highly charged tungsten ions in the extreme ultra-violet (EUV) by using electron beam ion traps. The electron energy dependence of spectra is investigated of electron energies from 490 to 1440 eV. Previously unreported lines are presented in the EUV range, and some of them are identified by comparing the wavelengths with theoretical calculations. (author)
19. EUV spectrum of highly charged tungsten ions in electron beam ion trap
International Nuclear Information System (INIS)
Sakaue, H.A.; Kato, D.; Murakami, I.; Nakamura, N.
2016-01-01
We present spectra of highly charged tungsten ions in the extreme ultra-violet (EUV) by using electron beam ion traps. The electron energy dependence of spectra was investigated for electron energy from 540 to 1370 eV. Previously unreported lines were presented in the EUV range, and comparing the wavelengths with theoretical calculations identified them. (author)
20. Techniques and mechanisms applied in electron cyclotron resonance sources for highly charged ions
NARCIS (Netherlands)
Drentje, AG
Electron cyclotron resonance ion sources are delivering beams of highly charged ions for a wide range of applications in many laboratories. For more than two decades, the development of these ion sources has been to a large extent an intuitive and experimental enterprise. Much effort has been spent
1. Fundamental processes determining the highly charged ion production in ECR ion sources
International Nuclear Information System (INIS)
Shirkov, G.D.
1992-01-01
The ion confinement and loss conditions in the open magnetic traps have been analyzed in this article. In EGRIS the the ions are confined in the negative potential well. The simultaneous application of ion cooling and pulse regime is proposed for pulse injection of highly charged ions in heavy ion accelerators and storage rings. 14 refs.; 3 figs
2. Prospects for Parity Non-conservation Experiments with Highly Charged Heavy Ions
OpenAIRE
Maul, M.; Schäfer, A.; Greiner, W.; Indelicato, P.
1996-01-01
We discuss the prospects for parity non-conservation experiments with highly charged heavy ions. Energy levels and parity mixing for heavy ions with two to five electrons are calculated. We investigate two-photon-transitions and the possibility to observe interference effects between weak-matrix elements and Stark matrix elements for periodic electric field configurations.
3. Prospects for parity-nonconservation experiments with highly charged heavy ions
OpenAIRE
Maul, Martin; Schäfer, Andreas; Greiner, Walter; Indelicato, Paul
2006-01-01
We discuss the prospects for parity-nonconservation experiments with highly charged heavy ions. Energy levels and parity mixing for heavy ions with 2–5 electrons are calculated. We investigate two-photon transitions and the possibility of observing interference effects between weak-matrix elements and Stark matrix elements for periodic electric field configurations.
4. Nanometer-size surface modification produced by single, low energy, highly charged ions
International Nuclear Information System (INIS)
Stockli, M.P.
1994-01-01
Atomically flat surfaces of insulators have been bombarded with low energy, highly charged ions to search for nanometer-size surface modifications. It is expected that the high electron deficiency of highly charged ions will capture and/or remove many of the insulator's localized electrons when impacting on an insulating surface. The resulting local electron deficiency is expected to locally disintegrate the insulator through a open-quotes Coulomb explosionclose quotes forming nanometer-size craters. Xe ions with charge states between 10+ and 45+ and kinetic energies between 0 and 10 keV/q were obtained from the KSU-CRYEBIS, a CRYogenic Electron Beam Ion Source and directed onto various insulating materials. Mica was favored as target material as atomically flat surfaces can be obtained reliably through cleaving. However, the authors observations with an atomic force microscope have shown that mica tends to defoliate locally rather than disintegrate, most likely due to the small binding forces between adjacent layers. So far the authors measurements indicate that each ion produces one blister if the charge state is sufficiently high. The blistering does not seem to depend very much on the kinetic energy of the ions
5. Enhanced intersystem crossing via a high energy charge transfer state in a perylenediimide-perylenemonoimide dyad
NARCIS (Netherlands)
Veldman, D.; Chopin-Cado, S.M.A; Meskers, S.C.J.; Janssen, R.A.J.
2008-01-01
The electronic relaxation processes of a photoexcited linear perylenediimide-perylenemonoimide (PDI-PMI) acceptor-donor dyad were studied. PDI-PMI serves as a model compound for donor-acceptor systems in photovoltaic devices and has been designed to have a high-energy PDI--PMI + charge transfer (CT)
6. Hall mobility of free charge carriers in highly compensated p-Germanium
International Nuclear Information System (INIS)
Gavrilyuk, V.Yi.; Kirnas, Yi.G.; Balakyin, V.D.
2000-01-01
Hall mobility of free charge carriers in initial detectors Ge (Ga) is studied. It is established that an increase in the compensation factor results in the enlargement of Hall mobility in germanium highly compensated by introduction of Li ions during their drift in an electrical field
7. Charge transfer and excitation in high-energy ion-atom collisions
International Nuclear Information System (INIS)
Schlachter, A.S.; Berkner, K.H.; McDonald, R.J.
1986-11-01
Coincidence measurements of charge transfer and simultaneous projectile electron excitation provide insight into correlated two-electron processes in energetic ion-atom collisions. Projectile excitation and electron capture can occur simultaneously in a collision of a highly charged ion with a target atom; this process is called resonant transfer and excitation (RTE). The intermediate excited state which is thus formed can subsequently decay by photon emission or by Auger-electron emission. Results are shown for RTE in both the K shell of Ca ions and the L shell of Nb ions, for simultaneous projectile electron loss and excitation, and for the effect of RTE on electron capture
8. Charged Particle Production in High Q2 Deep-Inelastic Scattering at HERA
CERN Document Server
Aaron, F.D.; Alexa, C.; Andreev, V.; Antunovic, B.; Aplin, S.; Asmone, A.; Astvatsatourov, A.; Backovic, S.; Baghdasaryan, A.; Baranov, P.; Barrelet, E.; Bartel, W.; Baudrand, S.; Beckingham, M.; Begzsuren, K.; Behnke, O.; Behrendt, O.; Belousov, A.; Berger, N.; Bizot, J.C.; Boenig, M.-O.; Boudry, V.; Bozovic-Jelisavcic, I.; Bracinik, J.; Brandt, G.; Brinkmann, M.; Brisson, V.; Bruncko, D.; Busser, F.W.; Bunyatyan, A.; Buschhorn, G.; Bystritskaya, L.; Campbell, A.J.; Cantun Avila, K.B.; Cassol-Brunner, F.; Cerny, K.; Cerny, V.; Chekelian, V.; Cholewa, A.; Contreras, J.G.; Coughlan, J.A.; Cozzika, G.; Cvach, J.; Dainton, J.B.; Daum, K.; Deak, M.; de Boer, Y.; Delcourt, B.; Del Degan, M.; Delvax, J.; De Roeck, A.; De Wolf, E.A.; Diaconu, C.; Dodonov, V.; Dubak, A.; Eckerlin, Guenter; Efremenko, V.; Egli, S.; Eichler, R.; Eisele, F.; Eliseev, A.; Elsen, E.; Essenov, S.; Falkiewicz, A.; Faulkner, P.J.W.; Favart, L.; Fedotov, A.; Felst, R.; Feltesse, J.; Ferencei, J.; Finke, L.; Fleischer, M.; Fomenko, A.; Franke, G.; Frisson, T.; Gabathuler, E.; Gayler, J.; Ghazaryan, Samvel; Ginzburgskaya, S.; Glazov, A.; Glushkov, I.; Goerlich, L.; Goettlich, M.; Gogitidze, N.; Gorbounov, S.; Gouzevitch, M.; Grab, C.; Greenshaw, T.; Grell, B.R.; Grindhammer, G.; Habib, S.; Haidt, D.; Hansson, M.; Heinzelmann, G.; Helebrant, C.; Henderson, R.C.W.; Henschel, H.; Herrera, G.; Hildebrandt, M.; Hiller, K.H.; Hoffmann, D.; Horisberger, R.; Hovhannisyan, A.; Hreus, T.; Jacquet, M.; Janssen, M.E.; Janssen, X.; Jemanov, V.; Jonsson, L.; Johnson, D.P.; Jung, Andreas Werner; Jung, H.; Kapichine, M.; Katzy, J.; Kenyon, I.R.; Kiesling, Christian M.; Klein, M.; Kleinwort, C.; Klimkovich, T.; Kluge, T.; Knutsson, A.; Korbel, V.; Kostka, P.; Kraemer, M.; Krastev, K.; Kretzschmar, J.; Kropivnitskaya, A.; Kruger, K.; Landon, M.P.J.; Lange, W.; Lastovicka-Medin, G.; Laycock, P.; Lebedev, A.; Leibenguth, G.; Lendermann, V.; Levonian, S.; Li, G.; Lindfeld, L.; Lipka, K.; Liptaj, A.; List, B.; List, J.; Loktionova, N.; Lopez-Fernandez, R.; Lubimov, V.; Lucaci-Timoce, A.-I.; Lytkin, L.; Makankine, A.; Malinovski, E.; Marage, P.; Marti, Ll.; Martisikova, M.; Martyn, H.-U.; Maxfield, S.J.; Mehta, A.; Meier, K.; Meyer, A.B.; Meyer, H.; Meyer, J.; Michels, V.; Mikocki, S.; Milcewicz-Mika, I.; Mohamed, A.; Moreau, F.; Morozov, A.; Morris, J.V.; Mozer, Matthias Ulrich; Muller, K.; Murin, P.; Nankov, K.; Naroska, B.; Naumann, Th.; Newman, Paul R.; Niebuhr, C.; Nikiforov, A.; Nowak, G.; Nowak, K.; Nozicka, M.; Oganezov, R.; Olivier, B.; Olsson, J.E.; Osman, S.; Ozerov, D.; Palichik, V.; Panagoulias, I.; Pandurovic, M.; Papadopoulou, Th.; Pascaud, C.; Patel, G.D.; Peng, H.; Perez, E.; Perez-Astudillo, D.; Perieanu, A.; Petrukhin, A.; Picuric, I.; Piec, S.; Pitzl, D.; Placakyte, R.; Polifka, R.; Povh, B.; Preda, T.; Prideaux, P.; Radescu, V.; Rahmat, A.J.; Raicevic, N.; Ravdandorj, T.; Reimer, P.; Risler, C.; Rizvi, E.; Robmann, P.; Roland, B.; Roosen, R.; Rostovtsev, A.; Rurikova, Z.; Rusakov, S.; Salek, D.; Salvaire, F.; Sankey, D.P.C.; Sauter, M.; Sauvan, E.; Schmidt, S.; Schmitt, S.; Schmitz, C.; Schoeffel, L.; Schoning, A.; Schultz-Coulon, H.-C.; Sefkow, F.; Shaw-West, R.N.; Sheviakov, I.; Shtarkov, L.N.; Sloan, T.; Smiljanic, Ivan; Smirnov, P.; Soloviev, Y.; South, D.; Spaskov, V.; Specka, Arnd E.; Staykova, Z.; Steder, M.; Stella, B.; Stiewe, J.; Straumann, U.; Sunar, D.; Sykora, T.; Tchoulakov, V.; Thompson, G.; Thompson, P.D.; Toll, T.; Tomasz, F.; Tran, T.H.; Traynor, D.; Trinh, T.N.; Truol, P.; Tsakov, I.; Tseepeldorj, B.; Tsipolitis, G.; Tsurin, I.; Turnau, J.; Tzamariudaki, E.; Urban, K.; Utkin, D.; Valkarova, A.; Vallee, C.; Van Mechelen, P.; Vargas Trevino, A.; Vazdik, Y.; Vinokurova, S.; Volchinski, V.; Weber, G.; Weber, R.; Wegener, D.; Werner, C.; Wessels, M.; Wissing, Ch.; Wolf, R.; Wunsch, E.; Xella, S.; Yeganov, V.; Zacek, J.; Zalesak, J.; Zhang, Z.; Zhelezov, A.; Zhokin, A.; Zhu, Y.C.; Zimmermann, T.; Zohrabyan, H.; Zomer, F.
2007-01-01
The average charged track multiplicity and the normalised distribution of the scaled momentum, $\\xp$, of charged final state hadrons are measured in deep-inelastic $\\ep$ scattering at high $Q^2$ in the Breit frame of reference. The analysis covers the range of photon virtuality $100 < Q^2 < 20 000 \\GeV^{2}$. Compared with previous results presented by HERA experiments this analysis has a significantly higher statistical precision and extends the phase space to higher $Q^{2}$ and to the full range of $\\xp$. The results are compared with $e^+e^-$ annihilation data and with various calculations based on perturbative QCD using different models of the hadronisation process.
9. Production of highly charged ions of argon by optical field ionization in a relativistic laser field
International Nuclear Information System (INIS)
Sagisaka, Akito; Akahane, Yutaka; Aoyama, Makoto; Nakano, Fumihiko; Yamakawa, Koichi
2001-01-01
We observed the highly charged ions of argon by optical field ionization in a relativistic intensity regime. Charge states up to Ar 15+ were produced at the highest intensity of 800 nm, linearly polarized 20 fs Ti: sapphire laser pulses. The peak intensity of the pulse is determined by comparing the measured ion production curve for Ar 9+ with ADK theory. The results of these measurements of the ionization indicate that the maximum peak intensity is achieved to ∼2x10 19 W/cm 2 . (author)
10. Charged particle production in high Q deep-inelastic scattering at HERA
Science.gov (United States)
H1 Collaboration; Aaron, F. D.; Aktas, A.; Alexa, C.; Andreev, V.; Antunovic, B.; Aplin, S.; Asmone, A.; Astvatsatourov, A.; Backovic, S.; Baghdasaryan, A.; Baranov, P.; Barrelet, E.; Bartel, W.; Baudrand, S.; Beckingham, M.; Begzsuren, K.; Behnke, O.; Behrendt, O.; Belousov, A.; Berger, N.; Bizot, J. C.; Boenig, M.-O.; Boudry, V.; Bozovic-Jelisavcic, I.; Bracinik, J.; Brandt, G.; Brinkmann, M.; Brisson, V.; Bruncko, D.; Büsser, F. W.; Bunyatyan, A.; Buschhorn, G.; Bystritskaya, L.; Campbell, A. J.; Avila, K. B. Cantun; Cassol-Brunner, F.; Cerny, K.; Cerny, V.; Chekelian, V.; Cholewa, A.; Contreras, J. G.; Coughlan, J. A.; Cozzika, G.; Cvach, J.; Dainton, J. B.; Daum, K.; Deak, M.; de Boer, Y.; Delcourt, B.; Del Degan, M.; Delvax, J.; de Roeck, A.; de Wolf, E. A.; Diaconu, C.; Dodonov, V.; Dubak, A.; Eckerlin, G.; Efremenko, V.; Egli, S.; Eichler, R.; Eisele, F.; Eliseev, A.; Elsen, E.; Essenov, S.; Falkiewicz, A.; Faulkner, P. J. W.; Favart, L.; Fedotov, A.; Felst, R.; Feltesse, J.; Ferencei, J.; Finke, L.; Fleischer, M.; Fomenko, A.; Franke, G.; Frisson, T.; Gabathuler, E.; Gayler, J.; Ghazaryan, S.; Ginzburgskaya, S.; Glazov, A.; Glushkov, I.; Goerlich, L.; Goettlich, M.; Gogitidze, N.; Gorbounov, S.; Gouzevitch, M.; Grab, C.; Greenshaw, T.; Gregori, M.; Grell, B. R.; Grindhammer, G.; Habib, S.; Haidt, D.; Hansson, M.; Heinzelmann, G.; Helebrant, C.; Henderson, R. C. W.; Henschel, H.; Herrera, G.; Hildebrandt, M.; Hiller, K. H.; Hoffmann, D.; Horisberger, R.; Hovhannisyan, A.; Hreus, T.; Jacquet, M.; Janssen, M. E.; Janssen, X.; Jemanov, V.; Jönsson, L.; Johnson, D. P.; Jung, A. W.; Jung, H.; Kapichine, M.; Katzy, J.; Kenyon, I. R.; Kiesling, C.; Klein, M.; Kleinwort, C.; Klimkovich, T.; Kluge, T.; Knutsson, A.; Korbel, V.; Kostka, P.; Kraemer, M.; Krastev, K.; Kretzschmar, J.; Kropivnitskaya, A.; Krüger, K.; Landon, M. P. J.; Lange, W.; Laštovička-Medin, G.; Laycock, P.; Lebedev, A.; Leibenguth, G.; Lendermann, V.; Levonian, S.; Li, G.; Lindfeld, L.; Lipka, K.; Liptaj, A.; List, B.; List, J.; Loktionova, N.; Lopez-Fernandez, R.; Lubimov, V.; Lucaci-Timoce, A.-I.; Lytkin, L.; Makankine, A.; Malinovski, E.; Marage, P.; Marti, Ll.; Martisikova, M.; Martyn, H.-U.; Maxfield, S. J.; Mehta, A.; Meier, K.; Meyer, A. B.; Meyer, H.; Meyer, H.; Meyer, J.; Michels, V.; Mikocki, S.; Milcewicz-Mika, I.; Mohamed, A.; Moreau, F.; Morozov, A.; Morris, J. V.; Mozer, M. U.; Müller, K.; Murín, P.; Nankov, K.; Naroska, B.; Naumann, Th.; Newman, P. R.; Niebuhr, C.; Nikiforov, A.; Nowak, G.; Nowak, K.; Nozicka, M.; Oganezov, R.; Olivier, B.; Olsson, J. E.; Osman, S.; Ozerov, D.; Palichik, V.; Panagoulias, I.; Pandurovic, M.; Papadopoulou, Th.; Pascaud, C.; Patel, G. D.; Peng, H.; Perez, E.; Perez-Astudillo, D.; Perieanu, A.; Petrukhin, A.; Picuric, I.; Piec, S.; Pitzl, D.; Plačakytė, R.; Polifka, R.; Povh, B.; Preda, T.; Prideaux, P.; Radescu, V.; Rahmat, A. J.; Raicevic, N.; Ravdandorj, T.; Reimer, P.; Risler, C.; Rizvi, E.; Robmann, P.; Roland, B.; Roosen, R.; Rostovtsev, A.; Rurikova, Z.; Rusakov, S.; Salek, D.; Salvaire, F.; Sankey, D. P. C.; Sauter, M.; Sauvan, E.; Schmidt, S.; Schmitt, S.; Schmitz, C.; Schoeffel, L.; Schöning, A.; Schultz-Coulon, H.-C.; Sefkow, F.; Shaw-West, R. N.; Sheviakov, I.; Shtarkov, L. N.; Sloan, T.; Smiljanic, I.; Smirnov, P.; Soloviev, Y.; South, D.; Spaskov, V.; Specka, A.; Staykova, Z.; Steder, M.; Stella, B.; Stiewe, J.; Straumann, U.; Sunar, D.; Sykora, T.; Tchoulakov, V.; Thompson, G.; Thompson, P. D.; Toll, T.; Tomasz, F.; Tran, T. H.; Traynor, D.; Trinh, T. N.; Truöl, P.; Tsakov, I.; Tseepeldorj, B.; Tsipolitis, G.; Tsurin, I.; Turnau, J.; Tzamariudaki, E.; Urban, K.; Utkin, D.; Valkárová, A.; Vallée, C.; van Mechelen, P.; Trevino, A. Vargas; Vazdik, Y.; Vinokurova, S.; Volchinski, V.; Weber, G.; Weber, R.; Wegener, D.; Werner, C.; Wessels, M.; Wissing, Ch.; Wolf, R.; Wünsch, E.; Xella, S.; Yeganov, V.; Žáček, J.; Zálešák, J.; Zhang, Z.; Zhelezov, A.; Zhokin, A.; Zhu, Y. C.; Zimmermann, T.; Zohrabyan, H.; Zomer, F.
2007-10-01
The average charged track multiplicity and the normalised distribution of the scaled momentum, x, of charged final state hadrons are measured in deep-inelastic ep scattering at high Q in the Breit frame of reference. The analysis covers the range of photon virtuality 100
11. Charged particle production in high Q2 deep-inelastic scattering at HERA
Science.gov (United States)
Aaron, F. D.; Aktas, A.; Alexa, C.; Andreev, V.; Antunovic, B.; Aplin, S.; Asmone, A.; Astvatsatourov, A.; Backovic, S.; Baghdasaryan, A.; Baranov, P.; Barrelet, E.; Bartel, W.; Baudrand, S.; Beckingham, M.; Begzsuren, K.; Behnke, O.; Behrendt, O.; Belousov, A.; Berger, N.; Bizot, J. C.; Boenig, M.-O.; Boudry, V.; Bozovic-Jelisavcic, I.; Bracinik, J.; Brandt, G.; Brinkmann, M.; Brisson, V.; Bruncko, D.; Büsser, F. W.; Bunyatyan, A.; Buschhorn, G.; Bystritskaya, L.; Campbell, A. J.; Avila, K. B. Cantun; Cassol-Brunner, F.; Cerny, K.; Cerny, V.; Chekelian, V.; Cholewa, A.; Contreras, J. G.; Coughlan, J. A.; Cozzika, G.; Cvach, J.; Dainton, J. B.; Daum, K.; Deak, M.; de Boer, Y.; Delcourt, B.; Del Degan, M.; Delvax, J.; De Roeck, A.; De Wolf, E. A.; Diaconu, C.; Dodonov, V.; Dubak, A.; Eckerlin, G.; Efremenko, V.; Egli, S.; Eichler, R.; Eisele, F.; Eliseev, A.; Elsen, E.; Essenov, S.; Falkiewicz, A.; Faulkner, P. J. W.; Favart, L.; Fedotov, A.; Felst, R.; Feltesse, J.; Ferencei, J.; Finke, L.; Fleischer, M.; Fomenko, A.; Franke, G.; Frisson, T.; Gabathuler, E.; Gayler, J.; Ghazaryan, S.; Ginzburgskaya, S.; Glazov, A.; Glushkov, I.; Goerlich, L.; Goettlich, M.; Gogitidze, N.; Gorbounov, S.; Gouzevitch, M.; Grab, C.; Greenshaw, T.; Gregori, M.; Grell, B. R.; Grindhammer, G.; Habib, S.; Haidt, D.; Hansson, M.; Heinzelmann, G.; Helebrant, C.; Henderson, R. C. W.; Henschel, H.; Herrera, G.; Hildebrandt, M.; Hiller, K. H.; Hoffmann, D.; Horisberger, R.; Hovhannisyan, A.; Hreus, T.; Jacquet, M.; Janssen, M. E.; Janssen, X.; Jemanov, V.; Jönsson, L.; Johnson, D. P.; Jung, A. W.; Jung, H.; Kapichine, M.; Katzy, J.; Kenyon, I. R.; Kiesling, C.; Klein, M.; Kleinwort, C.; Klimkovich, T.; Kluge, T.; Knutsson, A.; Korbel, V.; Kostka, P.; Kraemer, M.; Krastev, K.; Kretzschmar, J.; Kropivnitskaya, A.; Krüger, K.; Landon, M. P. J.; Lange, W.; Laštovička-Medin, G.; Laycock, P.; Lebedev, A.; Leibenguth, G.; Lendermann, V.; Levonian, S.; Li, G.; Lindfeld, L.; Lipka, K.; Liptaj, A.; List, B.; List, J.; Loktionova, N.; Lopez-Fernandez, R.; Lubimov, V.; Lucaci-Timoce, A.-I.; Lytkin, L.; Makankine, A.; Malinovski, E.; Marage, P.; Marti, Ll.; Martisikova, M.; Martyn, H.-U.; Maxfield, S. J.; Mehta, A.; Meier, K.; Meyer, A. B.; Meyer, H.; Meyer, H.; Meyer, J.; Michels, V.; Mikocki, S.; Milcewicz-Mika, I.; Mohamed, A.; Moreau, F.; Morozov, A.; Morris, J. V.; Mozer, M. U.; Müller, K.; Murín, P.; Nankov, K.; Naroska, B.; Naumann, Th.; Newman, P. R.; Niebuhr, C.; Nikiforov, A.; Nowak, G.; Nowak, K.; Nozicka, M.; Oganezov, R.; Olivier, B.; Olsson, J. E.; Osman, S.; Ozerov, D.; Palichik, V.; Panagoulias, I.; Pandurovic, M.; Papadopoulou, Th.; Pascaud, C.; Patel, G. D.; Peng, H.; Perez, E.; Perez-Astudillo, D.; Perieanu, A.; Petrukhin, A.; Picuric, I.; Piec, S.; Pitzl, D.; Plačakytė, R.; Polifka, R.; Povh, B.; Preda, T.; Prideaux, P.; Radescu, V.; Rahmat, A. J.; Raicevic, N.; Ravdandorj, T.; Reimer, P.; Risler, C.; Rizvi, E.; Robmann, P.; Roland, B.; Roosen, R.; Rostovtsev, A.; Rurikova, Z.; Rusakov, S.; Salek, D.; Salvaire, F.; Sankey, D. P. C.; Sauter, M.; Sauvan, E.; Schmidt, S.; Schmitt, S.; Schmitz, C.; Schoeffel, L.; Schöning, A.; Schultz-Coulon, H.-C.; Sefkow, F.; Shaw-West, R. N.; Sheviakov, I.; Shtarkov, L. N.; Sloan, T.; Smiljanic, I.; Smirnov, P.; Soloviev, Y.; South, D.; Spaskov, V.; Specka, A.; Staykova, Z.; Steder, M.; Stella, B.; Stiewe, J.; Straumann, U.; Sunar, D.; Sykora, T.; Tchoulakov, V.; Thompson, G.; Thompson, P. D.; Toll, T.; Tomasz, F.; Tran, T. H.; Traynor, D.; Trinh, T. N.; Truöl, P.; Tsakov, I.; Tseepeldorj, B.; Tsipolitis, G.; Tsurin, I.; Turnau, J.; Tzamariudaki, E.; Urban, K.; Utkin, D.; Valkárová, A.; Vallée, C.; Van Mechelen, P.; Trevino, A. Vargas; Vazdik, Y.; Vinokurova, S.; Volchinski, V.; Weber, G.; Weber, R.; Wegener, D.; Werner, C.; Wessels, M.; Wissing, Ch.; Wolf, R.; Wünsch, E.; Xella, S.; Yeganov, V.; Žáček, J.; Zálešák, J.; Zhang, Z.; Zhelezov, A.; Zhokin, A.; Zhu, Y. C.; Zimmermann, T.; Zohrabyan, H.; Zomer, F.; H1 Collaboration
2007-10-01
The average charged track multiplicity and the normalised distribution of the scaled momentum, xp, of charged final state hadrons are measured in deep-inelastic ep scattering at high Q2 in the Breit frame of reference. The analysis covers the range of photon virtuality 100
12. Plasmon-Sensitized Graphene/TiO2 Inverse Opal Nanostructures with Enhanced Charge Collection Efficiency for Water Splitting.
Science.gov (United States)
Boppella, Ramireddy; Kochuveedu, Saji Thomas; Kim, Heejun; Jeong, Myung Jin; Marques Mota, Filipe; Park, Jong Hyeok; Kim, Dong Ha
2017-03-01
In this contribution we have developed TiO 2 inverse opal based photoelectrodes for photoelectrochemical (PEC) water splitting devices, in which Au nanoparticles (NPs) and reduced graphene oxide (rGO) have been strategically incorporated (TiO 2 @rGO@Au). The periodic hybrid nanostructure showed a photocurrent density of 1.29 mA cm -2 at 1.23 V vs RHE, uncovering a 2-fold enhancement compared to a pristine TiO 2 reference. The Au NPs were confirmed to extensively broaden the absorption spectrum of TiO 2 into the visible range and to reduce the onset potential of these photoelectrodes. Most importantly, TiO 2 @rGO@Au hybrid exhibited a 14-fold enhanced PEC efficiency under visible light and a 2.5-fold enrichment in the applied bias photon-to-current efficiency at much lower bias potential compared with pristine TiO 2 . Incident photon-to-electron conversion efficiency measurements highlighted a synergetic effect between Au plasmon sensitization and rGO-mediated facile charge separation/transportation, which is believed to significantly enhance the PEC activity of these nanostructures under simulated and visible light irradiation. Under the selected operating conditions the incorporation of Au NPs and rGO into TiO 2 resulted in a remarkable boost in the H 2 evolution rate (17.8 μmol/cm 2 ) compared to a pristine TiO 2 photoelectrode reference (7.6 μmol/cm 2 ). In line with these results and by showing excellent stability as a photoelectrode, these materials are herin underlined to be of promising interest in the PEC water splitting reaction.
13. Process techniques of charge transfer time reduction for high speed CMOS image sensors
International Nuclear Information System (INIS)
Cao Zhongxiang; Li Quanliang; Han Ye; Qin Qi; Feng Peng; Liu Liyuan; Wu Nanjian
2014-01-01
This paper proposes pixel process techniques to reduce the charge transfer time in high speed CMOS image sensors. These techniques increase the lateral conductivity of the photo-generated carriers in a pinned photodiode (PPD) and the voltage difference between the PPD and the floating diffusion (FD) node by controlling and optimizing the N doping concentration in the PPD and the threshold voltage of the reset transistor, respectively. The techniques shorten the charge transfer time from the PPD diode to the FD node effectively. The proposed process techniques do not need extra masks and do not cause harm to the fill factor. A sub array of 32 × 64 pixels was designed and implemented in the 0.18 μm CIS process with five implantation conditions splitting the N region in the PPD. The simulation and measured results demonstrate that the charge transfer time can be decreased by using the proposed techniques. Comparing the charge transfer time of the pixel with the different implantation conditions of the N region, the charge transfer time of 0.32 μs is achieved and 31% of image lag was reduced by using the proposed process techniques. (semiconductor devices)
14. Perovskite Nanoparticle-Sensitized Ga2O3 Nanorod Arrays for CO Detection at High Temperature.
Science.gov (United States)
Lin, Hui-Jan; Baltrus, John P; Gao, Haiyong; Ding, Yong; Nam, Chang-Yong; Ohodnicki, Paul; Gao, Pu-Xian
2016-04-13
Noble metal nanoparticles are extensively used for sensitizing metal oxide chemical sensors through the catalytic spillover mechanism. However, due to earth-scarcity and high cost of noble metals, finding replacements presents a great economic benefit. Besides, high temperature and harsh environment sensor applications demand material stability under conditions approaching thermal and chemical stability limits of noble metals. In this study, we employed thermally stable perovskite-type La(0.8)Sr(0.2)FeO3 (LSFO) nanoparticle surface decoration on Ga2O3 nanorod array gas sensors and discovered an order of magnitude enhanced sensitivity to carbon monoxide at 500 °C. The LSFO nanoparticle catalysts was of comparable performance to that achieved by Pt nanoparticles, with a much lower weight loading than Pt. Detailed electron microscopy and X-ray photoelectron spectroscopy studies suggested the LSFO nanoparticle sensitization effect is attributed to a spillover-like effect associated with the gas-LSFO-Ga2O3 triple-interfaces that spread the negatively charged surface oxygen ions from LSFO nanoparticles surfaces over to β-Ga2O3 nanorod surfaces with faster surface CO oxidation reactions.
15. High order effects in cross section sensitivity analysis
International Nuclear Information System (INIS)
Greenspan, E.; Karni, Y.; Gilai, D.
1978-01-01
Two types of high order effects associated with perturbations in the flux shape are considered: Spectral Fine Structure Effects (SFSE) and non-linearity between changes in performance parameters and data uncertainties. SFSE are investigated in Part I using a simple single resonance model. Results obtained for each of the resolved and for representative unresolved resonances of 238 U in a ZPR-6/7 like environment indicate that SFSE can have a significant contribution to the sensitivity of group constants to resonance parameters. Methods to account for SFSE both for the propagation of uncertainties and for the adjustment of nuclear data are discussed. A Second Order Sensitivity Theory (SOST) is presented, and its accuracy relative to that of the first order sensitivity theory and of the direct substitution method is investigated in Part II. The investigation is done for the non-linear problem of the effect of changes in the 297 keV sodium minimum cross section on the transport of neutrons in a deep-penetration problem. It is found that the SOST provides a satisfactory accuracy for cross section uncertainty analysis. For the same degree of accuracy, the SOST can be significantly more efficient than the direct substitution method
16. Operationalization of the Russian Version of Highly Sensitive Person Scale
Directory of Open Access Journals (Sweden)
Регина Вячеславовна Ершова
2018-12-01
Full Text Available The aim of the present study was to operationalize a Russian version of the Highly Sensitive Person Scale (HSPS. The empirical data were collected in two ways: active, through oral advertising and inviting those who wish to take part in the study (snowball technique and passive (placement of ads about taking part in a research in social networks VKontakte and Facebook. As a result, 350 university students (117 men, 233 women, an average age of 18,2 (± 1,7 applied to a research laboratory and filled out the HSPS questionnaire, and another 510 respondents (380 women, 130 men, average age 22,6 ( ± 7,9 filled the HSPS online. The results of the study did not confirm the one-dimensional model of the construct, proposed by Aron & Aron (1997, as well as the most commonly used in the English-language studies three-factor solution. The hierarchical claster and confirmatory analyses used in the operationalization procedure allowed us to conclude that the variance of the Russian version of HSPS is best described in the framework of a two-factor model including the two separate subscales: Ease of Excitation (EOE, Low threshold of sensitivity (LTS. Sensory Processing Sensitivity may be defined as an increased susceptibility to external and internal stimuli, realized through negative emotional responses and deep susceptibility (distress to excessive stimulation.
17. A wide-bandwidth and high-sensitivity robust microgyroscope
International Nuclear Information System (INIS)
Sahin, Korhan; Sahin, Emre; Akin, Tayfun; Alper, Said Emre
2009-01-01
This paper reports a microgyroscope design concept with the help of a 2 degrees of freedom (DoF) sense mode to achieve a wide bandwidth without sacrificing mechanical and electronic sensitivity and to obtain robust operation against variations under ambient conditions. The design concept is demonstrated with a tuning fork microgyroscope fabricated with an in-house silicon-on-glass micromachining process. When the fabricated gyroscope is operated with a relatively wide bandwidth of 1 kHz, measurements show a relatively high raw mechanical sensitivity of 131 µV (° s −1 ) −1 . The variation in the amplified mechanical sensitivity (scale factor) of the gyroscope is measured to be less than 0.38% for large ambient pressure variations such as from 40 to 500 mTorr. The bias instability and angle random walk of the gyroscope are measured to be 131° h −1 and 1.15° h −1/2 , respectively
18. Ionization and fragmentation of water clusters by fast highly charged ions
International Nuclear Information System (INIS)
Adoui, L; Cassimi, A; Gervais, B; Grandin, J-P; Guillaume, L; Maisonny, R; Legendre, S; Tarisien, M; Lopez-Tarifa, P; Alcami, M; Martin, F; Politis, M-F; Penhoat, M-A Herve du; Vuilleumier, R; Gaigeot, M-P; Tavernelli, I
2009-01-01
We study the dissociative ionization of water clusters by impact of 12 MeV/u Ni 25+ ions. Cold target recoil ion momentum spectroscopy (COLTRIMS) is used to obtain information about stability, energetics and charge mobility of the ionized water clusters. An unusual stability of the H 9 O + 4 ion is observed, which could be the signature of the so-called Eigen structure in gas-phase water clusters. From the analysis of coincidences between charged fragments, we conclude that charge mobility is very high and is responsible for the formation of protonated water clusters, (H 2 O) n H + , that dominate the mass spectrum. These results are supported by Car-Parrinello molecular dynamics and time-dependent density functional theory simulations, which also reveal the mechanisms of such mobility.
19. Demonstration of cathode emittance dominated high bunch charge beams in a DC gun-based photoinjector
Energy Technology Data Exchange (ETDEWEB)
Gulliford, Colwyn, E-mail: cg248@cornell.edu; Bartnik, Adam, E-mail: acb20@cornell.edu; Bazarov, Ivan; Dunham, Bruce; Cultrera, Luca [CLASSE, Cornell University, 161 Synchrotron Drive Ithaca, New York 14853-8001 (United States)
2015-03-02
We present the results of transverse emittance and longitudinal current profile measurements of high bunch charge (≥100 pC) beams produced in the DC gun-based Cornell energy recovery linac photoinjector. In particular, we show that the cathode thermal and core beam emittances dominate the final 95% and core emittances measured at 9–9.5 MeV. Additionally, we demonstrate excellent agreement between optimized 3D space charge simulations and measurement, and show that the quality of the transverse laser distribution limits the optimal simulated and measured emittances. These results, previously thought achievable only with RF guns, demonstrate that DC gun based photoinjectors are capable of delivering beams with sufficient single bunch charge and beam quality suitable for many current and next generation accelerator projects such as Energy Recovery Linacs and Free Electron Lasers.
20. Charge- and transverse momentum dependence of correlations in proton-proton interactions at very high energies
International Nuclear Information System (INIS)
Hofmann, W.
1977-07-01
The charge- and momentum dependence of correlations between secondaries emitted in pp-collisions at √s = 52 GeV was investigated using the Split-Field-Magnet spectrometer at the CERN Intersecting Storage Rings (ISR). For nondiffractive inelastic events the central particle production is characterized by local conservation of charge and global compensation of transverse momenta. Strong short range correlations due to cluster decay and Bose-Einstein effects are observed. A consistent description of the correlations is given in the framework of cluster models. Local conservation of charge is also detected in events, where a particle of high transverse momentum is produced. The observations are in good agreement with the predictions of a simple quark parton model. (orig.) [de
1. High-energy behavior of the charge-transfer cross section in the eikonal approximation
International Nuclear Information System (INIS)
Dewangan, D.P.
1982-01-01
In the now popular version of the eikonal theory of charge transfer, the eikonal wave function does not satisfy the proper boundary conditions and the charge-transfer amplitude is uncertain by an undefined phase factor. The inclusion of the internuclear potential in a consistent way, in the eikonal theory overcomes theses difficulties. However, it also changes the high-energy asymptotic form of proton-hydrogen charge-transfer cross section from sigma/sub eik/ approx.(23/48) sigma/sub BK/ by a small amount to sigma/sub G/approx.(20.109/48)sigma/sub BK/ where sigma/sub BK/ is the Brinkman-Kramers cross section
2. Development of an underwater high sensitivity Cherenkov detector: Sea Urchin
International Nuclear Information System (INIS)
Camerini, U.; McGibney, D.; Roberts, A.
1982-01-01
The need for a high gain, high sensitivity Cherenkov light sensor to be used in a deep underwater muon and neutrino detector (DUMAND) array has led to the design of the Sea Urchin detector. In this design a spherical photocathode PMTis optically coupled through a glass hemisphere to a large number of glass spines, each of which is filled with a wavelength-shifting (WLS) solution of a high quantum efficiency phosphor. The Cherenkov radiation is absorbed in the spine, isotropically re-radiated at a longer wavelength, and a fraction of the fluorescent light is internally reflected in the spine, and guided to the photomultiplier concentrically located in the glass hemisphere. Experiments measuring the optical characteristics of the spines and computer programs simulating light transformation and detection cross sections are described. Overall optical gains in the range 5-10 are achieved. The WLS solution is inexpensive, and may have other applications. (orig.)
3. Position sensitive detection of neutrons in high radiation background field.
Science.gov (United States)
Vavrik, D; Jakubek, J; Pospisil, S; Vacik, J
2014-01-01
We present the development of a high-resolution position sensitive device for detection of slow neutrons in the environment of extremely high γ and e(-) radiation background. We make use of a planar silicon pixelated (pixel size: 55 × 55 μm(2)) spectroscopic Timepix detector adapted for neutron detection utilizing very thin (10)B converter placed onto detector surface. We demonstrate that electromagnetic radiation background can be discriminated from the neutron signal utilizing the fact that each particle type produces characteristic ionization tracks in the pixelated detector. Particular tracks can be distinguished by their 2D shape (in the detector plane) and spectroscopic response using single event analysis. A Cd sheet served as thermal neutron stopper as well as intensive source of gamma rays and energetic electrons. Highly efficient discrimination was successful even at very low neutron to electromagnetic background ratio about 10(-4).
4. Highly Sensitive Flexible Magnetic Sensor Based on Anisotropic Magnetoresistance Effect.
Science.gov (United States)
Wang, Zhiguang; Wang, Xinjun; Li, Menghui; Gao, Yuan; Hu, Zhongqiang; Nan, Tianxiang; Liang, Xianfeng; Chen, Huaihao; Yang, Jia; Cash, Syd; Sun, Nian-Xiang
2016-11-01
A highly sensitive flexible magnetic sensor based on the anisotropic magnetoresistance effect is fabricated. A limit of detection of 150 nT is observed and excellent deformation stability is achieved after wrapping of the flexible sensor, with bending radii down to 5 mm. The flexible AMR sensor is used to read a magnetic pattern with a thickness of 10 μm that is formed by ferrite magnetic inks. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
5. High sensitivity on-line monitor for radioactive effluent
Energy Technology Data Exchange (ETDEWEB)
Sasaki, Toshimi [Tohoku Electric Power Co. Ltd., Sendai (Japan); Ishizuka, Akira; Abe, Eisuke; Inoue, Yasuhiko; Fujii, Masaaki; Kitaguchi, Hiroshi; Doi, Akira
1983-04-01
A new approach for a highly sensitive effluent monitor is presented. The free flow type monitor, which consists of a straightener, nozzle, monitoring section and ..gamma..-ray detector, is demonstrated to be effective in providing long term stability. The 160 start-and-stop cycles of effluent discharge were repeated in a 120-h testing period. Results showed a background increase was not observed for the free flow type monitor. The background count rate was calibrated to the lowest detection limit to be 2.2 x 10/sup -2/ Bq/ml for a 300 s measurement time.
6. High-Sensitivity Measurement of Density by Magnetic Levitation.
Science.gov (United States)
Nemiroski, Alex; Kumar, A A; Soh, Siowling; Harburg, Daniel V; Yu, Hai-Dong; Whitesides, George M
2016-03-01
This paper presents methods that use Magnetic Levitation (MagLev) to measure very small differences in density of solid diamagnetic objects suspended in a paramagnetic medium. Previous work in this field has shown that, while it is a convenient method, standard MagLev (i.e., where the direction of magnetization and gravitational force are parallel) cannot resolve differences in density mm) because (i) objects close in density prevent each other from reaching an equilibrium height due to hard contact and excluded volume, and (ii) using weaker magnets or reducing the magnetic susceptibility of the medium destabilizes the magnetic trap. The present work investigates the use of weak magnetic gradients parallel to the faces of the magnets as a means of increasing the sensitivity of MagLev without destabilization. Configuring the MagLev device in a rotated state (i.e., where the direction of magnetization and gravitational force are perpendicular) relative to the standard configuration enables simple measurements along the axes with the highest sensitivity to changes in density. Manipulating the distance of separation between the magnets or the lengths of the magnets (along the axis of measurement) enables the sensitivity to be tuned. These modifications enable an improvement in the resolution up to 100-fold over the standard configuration, and measurements with resolution down to 10(-6) g/cm(3). Three examples of characterizing the small differences in density among samples of materials having ostensibly indistinguishable densities-Nylon spheres, PMMA spheres, and drug spheres-demonstrate the applicability of rotated Maglev to measuring the density of small (0.1-1 mm) objects with high sensitivity. This capability will be useful in materials science, separations, and quality control of manufactured objects.
7. High temperature cathodic charging of hydrogen in zirconium alloys and iron and nickel base alloys
International Nuclear Information System (INIS)
John, J.T.; De, P.K.; Gadiyar, H.S.
1990-01-01
These investigations lead to the development of a new technique for charging hydrogen into metals and alloys. In this technique a mixture of sulfates and bisulfates of sodium and potassium is kept saturated with water at 250-300degC in an open pyrex glass beaker and electrolysed using platinum anode and the material to be charged as the cathode. Most of the studies were carried out on Zr alloys. It is shown that because of the high hydrogen flux available at the surface and the high diffusivity of hydrogen in metals at these temperatures the materials pick up hydrogen faster and more uniformly than the conventional electrolytic charging at room temperature and high temperature autoclaving in LiOH solutions. Chemical analysis, metallographic examination and XRD studies confirm this. This technique has been used to charge hydrogen into many iron and nickel base austentic alloys, which are very resistant to hydrogen pick up and to H-embrittlement. Since this involved a novel method of electrolysing water, the hydrogen/deuterium isotopic ratio has been studied. At this temperatures the D/H ratio in the evolved hydrogen gas was found to be closer to the value in the liquid water, which means a smaller separation factor. This confirm the earlier observation that separation factor decreases with increase of temperature. (author). 16 refs., 21 fi gs., 6 tabs
8. Realization of ppm-level CO detection with exceptionally high sensitivity using reduced graphene oxide-loaded SnO2 nanofibers with simultaneous Au functionalization.
Science.gov (United States)
Kim, Jae-Hun; Katoch, Akash; Kim, Hyoun Woo; Kim, Sang Sub
2016-03-07
We have realized the highly sensitive, selective ppm-level carbon monoxide (CO) detection based on graphene oxide (RGO) nanosheets-loaded SnO2 nanofibers with simultaneous Au functionalization. The interplay between RGO/Au and SnO2 in terms of transfer of charge carriers and modulation of potential barriers is responsible for the exceptionally high CO detectability.
9. Dye-sensitized solar cells employing doubly or singly open-ended TiO2 nanotube arrays: structural geometry and charge transport.
Science.gov (United States)
Choi, Jongmin; Song, Seulki; Kang, Gyeongho; Park, Taiho
2014-09-10
We systematically investigated the charge transport properties of doubly or singly open-ended TiO2 nanotube arrays (DNT and SNT, respectively) for their utility as electrodes in dye-sensitized solar cells (DSCs). The SNT or DNT arrays were transferred in a bottom-up (B-up) or top-up (T-up) configuration onto a fluorine-doped tin oxide (FTO) substrate onto which had been deposited a 2 μm thick TiO2 nanoparticle (NP) interlayer. This process yielded four types of DSCs prepared with SNTs (B-up or T-up) or DNT (B-up or T-up). The photovoltaic performances of these DSCs were analyzed by measuring the dependence of the charge transport on the DSC geometry. High resolution scanning electron microscopy techniques were used to characterize the electrode cross sections, and electrochemical impedance spectroscopy was used to characterize the electrical connection at the interface between the NT array and the TiO2 NP interlayer. We examined the effects of decorating the DNT or SNT arrays with small NPs (sNP@DNT and sNP@SNT, respectively) in an effort to increase the extent of dye loading. The DNT arrays decorated with small NPs performed better than the decorated SNT arrays, most likely because the Ti(OH)4 precursor solution flowed freely into the array through the open ends of the NTs in the DNT case but not in the SNT case. The sNP@DNT-based DSC exhibited a better PCE (10%) compared to the sNP@SNT-based DSCs (6.8%) because the electrolyte solution flow was not restricted, direct electron transport though the NT arrays was possible, the electrical connection at the interface between the NT array and the TiO2 NP interlayer was good, and the array provided efficient light harvesting.
10. Nanoclay gelation approach toward improved dye-sensitized solar cell efficiencies: an investigation of charge transport and shift in the TiO2 conduction band.
Science.gov (United States)
Wang, Xiu; Kulkarni, Sneha A; Ito, Bruno Ieiri; Batabyal, Sudip K; Nonomura, Kazuteru; Wong, Chee Cheong; Grätzel, Michael; Mhaisalkar, Subodh G; Uchida, Satoshi
2013-01-23
Nanoclay minerals play a promising role as additives in the liquid electrolyte to form a gel electrolyte for quasi-solid-state dye-sensitized solar cells, because of the high chemical stability, unique swelling capability, ion exchange capacity, and rheological properties of nanoclays. Here, we report the improved performance of a quasi-solid-state gel electrolyte that is made from a liquid electrolyte and synthetic nitrate-hydrotalcite nanoclay. Charge transport mechanisms in the gel electrolyte and nanoclay interactions with TiO(2)/electrolyte interface are discussed in detail. The electrochemical analysis reveals that the charge transport is solely based on physical diffusion at the ratio of [PMII]:[I(2)] = 10:1 (where PMII is 1-propyl-3-methylimidazolium iodide). The calculated physical diffusion coefficient shows that the diffusion of redox ions is not affected much by the viscosity of nanoclay gel. The addition of nitrate-hydrotalcite clay in the electrolyte has the effect of buffering the protonation process at the TiO(2)/electrolyte interface, resulting in an upward shift in the conduction band and a boost in open-circuit voltage (V(OC)). Higher V(OC) values with undiminished photocurrent is achieved with nitrate-hydrotalcite nanoclay gel electrolyte for organic as well as for inorganic dye (D35 and N719) systems. The efficiency for hydrotalcite clay gel electrolyte solar cells is increased by 10%, compared to that of the liquid electrolyte. The power conversion efficiency can reach 10.1% under 0.25 sun and 9.6% under full sun. This study demonstrates that nitrate-hydrotalcite nanoclay in the electrolyte not only solidifies the liquid electrolyte to prevent solvent leakage, but also facilitates the improvement in cell efficiency.
11. Radiative recombination of highly charged ions: Enhanced rates at low energies
International Nuclear Information System (INIS)
Frank, A.; Mueller, A.; Haselbauer, J.; Schennach, S.; Spies, W.; Uwira, O.; Wagner, M.
1992-01-01
In a single-pass merged-beams experiment employing a dense cold electron target recombination of highly charged ions is studied. Unexpected high recombination rates are observed at low energies E cm in the electron-ion center-of-mass frame. In particular, theoretical estimates for radiative recombination are dramatically exceeded by the experimental recombination rates at E cm =0 eV for U 28+ and for Au 25+ ions. Considerable rate enhancement is also observed for Ar 15+ . This points to a general phenomenon which has to be interpreted as a consequence of high electron densities, low electron beam temperatures, high ion charge states and presence of strong magnetic fields. (orig.)
12. The electrical charging of inactive aerosols in high ionised atmosphere, the electrical charging of artificial beta radioactive aerosols; Le processus de charge electrique: des aerosols non radioactifs en milieu fortement ionise, des aerosols radioactifs artificiels emetteurs beta
Energy Technology Data Exchange (ETDEWEB)
Gensdarmes, F
2000-07-01
The electrical properties of aerosols greatly influence their transport and deposition in a containment. In a bipolar ionic atmosphere, a neutral electric charge on aerosols is commonly assumed. However, many studies report a different charge distribution in some situations, like highly ionised atmosphere or in the case of radioactive aerosols. Such situations could arise from a hypothetical accident in a nuclear power plant. Within the framework of safety studies which are carried out at IPSN, our aims were the study of electrical properties of aerosols in highly ionised atmosphere, and the study of artificial radioactive aerosols, in order to suggest experimental validation of available theories. For this purpose, we designed an experimental device that allows us to measure non-radioactive aerosol charge distribution under high gamma irradiation, up to 10{sup 4} Gy/h. With our experimental device we also studied the properties of small ions in the medium. Our results show a variation of the charge distribution in highly ionised atmosphere. The charge increases with the dose of gamma ray. We have related this variation with the one of the small ions in the gases, according to theoretical prediction. However, the model overestimates slightly our experimental results. In the case of the radioactive aerosols, we have designed an original experimental device, which allows us to study the charge distribution of a {sup 137}Cs aerosol. Our results show that the electric charging of such aerosols is strongly dependent on evolution parameters in a containment. So, our results underline a great enhancement of self-charging of particles which are sampled in a confined medium. Our results are qualitatively in agreement with the theoretical model; nevertheless the latter underestimates appreciably the self-charging, owing to the fact that wall effects are not taken into account. (author)
13. 2KJ/S 1KV, 25HZ PRR capacitor charging power supply with twin phase shifted primary windings to achieve high charge transfer rate and stability
International Nuclear Information System (INIS)
Kelkar, Y.; Singh, Y.P.; Thakurta, A.C.
2013-01-01
The capacitor charging power supply (CCPS) was developed to charge bank of 150uF energy storage capacitor (15uf , 10 nos in parallel) upto 1kV in 35 ms exhibiting a peak charging power of 2 kJ/s at a repetition rate of 25 pps. A CCPS observes a large change in load variations at the output. Initially the capacitor will act as a short circuit so the topology must be such that it should withstand short circuit condition repetitively. The High Voltage capacitor charging power supply consist of two identical full bridge resonant converters feeding to two primary windings of a transformer with rectified secondary connected to capacitor load. Topology selection is based on the fact that the series resonant converter with switching frequency f s , below 50% of the resonant frequency f r (f s ≤ 0.5 f r ) act as a current source. (author)
14. Synthetic high-charge organomica: effect of the layer charge and alkyl chain length on the structure of the adsorbed surfactants.
Science.gov (United States)
Pazos, M Carolina; Castro, Miguel A; Orta, M Mar; Pavón, Esperanza; Valencia Rios, Jesús S; Alba, María D
2012-05-15
A family of organomicas was synthesized using synthetic swelling micas with high layer charge (Na(n)Si(8-n)Al(n)Mg(6)F(4)O(20)·XH(2)O, where n = 2, 3, and 4) exchanged with dodecylammonium and octadecylammonium cations. The molecular arrangement of the surfactant was elucidated on the basis on XRD patterns and DTA. The ordering conformation of the surfactant molecules into the interlayer space of micas was investigated by (13)C, (27)Al, and (29)Si MAS NMR. The arrangement of alkylammonium ions in these high-charge synthetic micas depends on the combined effects of the layer charge of the mica and the chain length of the cation. In the organomicas with dodecylammonium, a transition from a parallel layer to a bilayer-paraffin arrangement is observed when the layer charge of the mica increases. However, when octadecylammonium is the interlayer cation, the molecular arrangement of the surfactant was found to follow the bilayer-paraffin model for all values of layer charge. The amount of ordered conformation all-trans is directly proportional of layer charge.
15. High pressure-sensitive gene expression in Lactobacillus sanfranciscensis
Directory of Open Access Journals (Sweden)
R.F. Vogel
2005-08-01
Full Text Available Lactobacillus sanfranciscensis is a Gram-positive lactic acid bacterium used in food biotechnology. It is necessary to investigate many aspects of a model organism to elucidate mechanisms of stress response, to facilitate preparation, application and performance in food fermentation, to understand mechanisms of inactivation, and to identify novel tools for high pressure biotechnology. To investigate the mechanisms of the complex bacterial response to high pressure we have analyzed changes in the proteome and transcriptome by 2-D electrophoresis, and by microarrays and real time PCR, respectively. More than 16 proteins were found to be differentially expressed upon high pressure stress and were compared to those sensitive to other stresses. Except for one apparently high pressure-specific stress protein, no pressure-specific stress proteins were found, and the proteome response to pressure was found to differ from that induced by other stresses. Selected pressure-sensitive proteins were partially sequenced and their genes were identified by reverse genetics. In a transcriptome analysis of a redundancy cleared shot gun library, about 7% of the genes investigated were found to be affected. Most of them appeared to be up-regulated 2- to 4-fold and these results were confirmed by real time PCR. Gene induction was shown for some genes up-regulated at the proteome level (clpL/groEL/rbsK, while the response of others to high hydrostatic pressure at the transcriptome level seemed to differ from that observed at the proteome level. The up-regulation of selected genes supports the view that the cell tries to compensate for pressure-induced impairment of translation and membrane transport.
16. Highly Sensitive Switchable Heterojunction Photodiode Based on Epitaxial Bi2FeCrO6 Multiferroic Thin Films.
Science.gov (United States)
Huang, Wei; Chakrabartty, Joyprokash; Harnagea, Catalin; Gedamu, Dawit; Ka, Ibrahima; Chaker, Mohamed; Rosei, Federico; Nechache, Riad
2018-04-18
Perovskite multiferroic oxides are promising materials for the realization of sensitive and switchable photodiodes because of their favorable band gap (heterojunction was fabricated by pulsed laser deposition. The heterojunction photodiode exhibits a large ideality factor ( n = ∼5.0) and a response time as fast as 68 ms, thanks to the effective charge carrier transport and collection at the BFCO/SRO interface. The diode can switch direction when the electric polarization is reversed by an external voltage pulse. The time-resolved photoluminescence decay of the device measured at ∼500 nm demonstrates an ultrafast charge transfer (lifetime = ∼6.4 ns) in BFCO/SRO heteroepitaxial structures. The estimated responsivity value at 500 nm and zero bias is 0.38 mA W -1 , which is so far the highest reported for any FE thin film photodiode. Our work highlights the huge potential for using multiferroic oxides to fabricate highly sensitive and switchable photodiodes.
17. A simple, tunable, and highly sensitive radio-frequency sensor.
Science.gov (United States)
Cui, Yan; Sun, Jiwei; He, Yuxi; Wang, Zheng; Wang, Pingshan
2013-08-05
We report a radio frequency (RF) sensor that exploits tunable attenuators and phase shifters to achieve high-sensitivity and broad band frequency tunability. Three frequency bands are combined to enable sensor operations from ∼20 MHz to ∼38 GHz. The effective quality factor ( Q eff ) of the sensor is as high as ∼3.8 × 10 6 with 200 μ l of water samples. We also demonstrate the measurement of 2-proponal-water-solution permittivity at 0.01 mole concentration level from ∼1 GHz to ∼10 GHz. Methanol-water solution and de-ionized water are used to calibrate the RF sensor for the quantitative measurements.
18. Correcting systematic errors in high-sensitivity deuteron polarization measurements
Science.gov (United States)
Brantjes, N. P. M.; Dzordzhadze, V.; Gebel, R.; Gonnella, F.; Gray, F. E.; van der Hoek, D. J.; Imig, A.; Kruithof, W. L.; Lazarus, D. M.; Lehrach, A.; Lorentz, B.; Messi, R.; Moricciani, D.; Morse, W. M.; Noid, G. A.; Onderwater, C. J. G.; Özben, C. S.; Prasuhn, D.; Levi Sandri, P.; Semertzidis, Y. K.; da Silva e Silva, M.; Stephenson, E. J.; Stockhorst, H.; Venanzoni, G.; Versolato, O. O.
2012-02-01
This paper reports deuteron vector and tensor beam polarization measurements taken to investigate the systematic variations due to geometric beam misalignments and high data rates. The experiments used the In-Beam Polarimeter at the KVI-Groningen and the EDDA detector at the Cooler Synchrotron COSY at Jülich. By measuring with very high statistical precision, the contributions that are second-order in the systematic errors become apparent. By calibrating the sensitivity of the polarimeter to such errors, it becomes possible to obtain information from the raw count rate values on the size of the errors and to use this information to correct the polarization measurements. During the experiment, it was possible to demonstrate that corrections were satisfactory at the level of 10 -5 for deliberately large errors. This may facilitate the real time observation of vector polarization changes smaller than 10 -6 in a search for an electric dipole moment using a storage ring.
19. Correcting systematic errors in high-sensitivity deuteron polarization measurements
Energy Technology Data Exchange (ETDEWEB)
Brantjes, N.P.M. [Kernfysisch Versneller Instituut, University of Groningen, NL-9747AA Groningen (Netherlands); Dzordzhadze, V. [Brookhaven National Laboratory, Upton, NY 11973 (United States); Gebel, R. [Institut fuer Kernphysik, Juelich Center for Hadron Physics, Forschungszentrum Juelich, D-52425 Juelich (Germany); Gonnella, F. [Physica Department of ' Tor Vergata' University, Rome (Italy); INFN-Sez. ' Roma tor Vergata,' Rome (Italy); Gray, F.E. [Regis University, Denver, CO 80221 (United States); Hoek, D.J. van der [Kernfysisch Versneller Instituut, University of Groningen, NL-9747AA Groningen (Netherlands); Imig, A. [Brookhaven National Laboratory, Upton, NY 11973 (United States); Kruithof, W.L. [Kernfysisch Versneller Instituut, University of Groningen, NL-9747AA Groningen (Netherlands); Lazarus, D.M. [Brookhaven National Laboratory, Upton, NY 11973 (United States); Lehrach, A.; Lorentz, B. [Institut fuer Kernphysik, Juelich Center for Hadron Physics, Forschungszentrum Juelich, D-52425 Juelich (Germany); Messi, R. [Physica Department of ' Tor Vergata' University, Rome (Italy); INFN-Sez. ' Roma tor Vergata,' Rome (Italy); Moricciani, D. [INFN-Sez. ' Roma tor Vergata,' Rome (Italy); Morse, W.M. [Brookhaven National Laboratory, Upton, NY 11973 (United States); Noid, G.A. [Indiana University Cyclotron Facility, Bloomington, IN 47408 (United States); and others
2012-02-01
This paper reports deuteron vector and tensor beam polarization measurements taken to investigate the systematic variations due to geometric beam misalignments and high data rates. The experiments used the In-Beam Polarimeter at the KVI-Groningen and the EDDA detector at the Cooler Synchrotron COSY at Juelich. By measuring with very high statistical precision, the contributions that are second-order in the systematic errors become apparent. By calibrating the sensitivity of the polarimeter to such errors, it becomes possible to obtain information from the raw count rate values on the size of the errors and to use this information to correct the polarization measurements. During the experiment, it was possible to demonstrate that corrections were satisfactory at the level of 10{sup -5} for deliberately large errors. This may facilitate the real time observation of vector polarization changes smaller than 10{sup -6} in a search for an electric dipole moment using a storage ring.
20. Wide bandwidth transimpedance amplifier for extremely high sensitivity continuous measurements.
Science.gov (United States)
Ferrari, Giorgio; Sampietro, Marco
2007-09-01
This article presents a wide bandwidth transimpedance amplifier based on the series of an integrator and a differentiator stage, having an additional feedback loop to discharge the standing current from the device under test (DUT) to ensure an unlimited measuring time opportunity when compared to switched discharge configurations while maintaining a large signal amplification over the full bandwidth. The amplifier shows a flat response from 0.6 Hz to 1.4 MHz, the capability to operate with leakage currents from the DUT as high as tens of nanoamperes, and rail-to-rail dynamic range for sinusoidal current signals independent of the DUT leakage current. Also available is a monitor output of the stationary current to track experimental slow drifts. The circuit is ideal for noise spectral and impedance measurements of nanodevices and biomolecules when in the presence of a physiological medium and in all cases where high sensitivity current measurements are requested such as in scanning probe microscopy systems.
1. High-k shallow traps observed by charge pumping with varying discharging times
Energy Technology Data Exchange (ETDEWEB)
Ho, Szu-Han; Chen, Ching-En; Tseng, Tseung-Yuen [Department of Electronics Engineering, National Chiao Tung University, Hsinchu 300, Taiwan (China); Chang, Ting-Chang, E-mail: tcchang@mail.phys.nsysu.edu.tw [Department of Physics, National Sun Yat-Sen University, Kaohsiung 804, Taiwan (China); Advanced Optoelectronics Technology Center, National Cheng Kung University, Tainan, Taiwan (China); Lu, Ying-Hsin; Lo, Wen-Hung; Tsai, Jyun-Yu; Liu, Kuan-Ju [Department of Physics, National Sun Yat-Sen University, Kaohsiung 804, Taiwan (China); Wang, Bin-Wei; Cao, Xi-Xin [Department of Embedded System Engineering, Peking University, Beijing, P.R.China (China); Chen, Hua-Mao [Department of Photonics and Institute of Electro-Optical Engineering, National Chiao Tung University, Hsinchu, Taiwan (China); Cheng, Osbert; Huang, Cheng-Tung; Chen, Tsai-Fu [Device Department, United Microelectronics Corporation, Tainan Science Park, Taiwan (China)
2013-11-07
In this paper, we investigate the influence of falling time and base level time on high-k bulk shallow traps measured by charge pumping technique in n-channel metal-oxide-semiconductor field-effect transistors with HfO{sub 2}/metal gate stacks. N{sub T}-V{sub high} {sub level} characteristic curves with different duty ratios indicate that the electron detrapping time dominates the value of N{sub T} for extra contribution of I{sub cp} traps. N{sub T} is the number of traps, and I{sub cp} is charge pumping current. By fitting discharge formula at different temperatures, the results show that extra contribution of I{sub cp} traps at high voltage are in fact high-k bulk shallow traps. This is also verified through a comparison of different interlayer thicknesses and different Ti{sub x}N{sub 1−x} metal gate concentrations. Next, N{sub T}-V{sub high} {sub level} characteristic curves with different falling times (t{sub falling} {sub time}) and base level times (t{sub base} {sub level}) show that extra contribution of I{sub cp} traps decrease with an increase in t{sub falling} {sub time}. By fitting discharge formula for different t{sub falling} {sub time}, the results show that electrons trapped in high-k bulk shallow traps first discharge to the channel and then to source and drain during t{sub falling} {sub time}. This current cannot be measured by the charge pumping technique. Subsequent measurements of N{sub T} by charge pumping technique at t{sub base} {sub level} reveal a remainder of electrons trapped in high-k bulk shallow traps.
2. Properties of Laser-Produced Highly Charged Heavy Ions for Direct Injection Scheme
CERN Document Server
Sakakibara, Kazuhiko; Hayashizaki, Noriyosu; Ito, Taku; Kashiwagi, Hirotsugu; Okamura, Masahiro
2005-01-01
To accelerate highly charged intense ion beam, we have developed the Direct Plasma Injection Scheme (DPIS) with laser ion source. In this scheme an ion beam from a laser ion source is injected directly to a RFQ linac without a low energy beam transport (LEBT) and the beam loss in the LEBT can be avoided. We achieved high current acceleration of carbon ions (60mA) by DPIS with the high current optimized RFQ. As the next setp we will use heavier elements like Ag, Pb, Al and Cu as target in LIS (using CO2, Nd-YAG or other laser) for DPIS and will examine properties of laser-produced plasma (the relationship of between charge state and laser power density, the current dependence of the distance from the target, etc).
3. Highly efficient tandem organic light-emitting devices employing an easily fabricated charge generation unit
Science.gov (United States)
Yang, Huishan; Yu, Yaoyao; Wu, Lishuang; Qu, Biao; Lin, Wenyan; Yu, Ye; Wu, Zhijun; Xie, Wenfa
2018-02-01
We have realized highly efficient tandem organic light-emitting devices (OLEDs) employing an easily fabricated charge generation unit (CGU) combining 1,4,5,8,9,11-hexaazatriphenylene-hexacarbonitrile with ultrathin bilayers of CsN3 and Al. The charge generation and separation processes of the CGU have been demonstrated by studying the differences in the current density-voltage characteristics of external-carrier-excluding devices. At high luminances of 1000 and 10000 cd/m2, the current efficiencies of the phosphorescent tandem device are about 2.2- and 2.3-fold those of the corresponding single-unit device, respectively. Simultaneously, an efficient tandem white OLED exhibiting high color stability and warm white emission has also been fabricated.
4. High-Sensitivity Temperature-Independent Silicon Photonic Microfluidic Biosensors
Science.gov (United States)
Kim, Kangbaek
Optical biosensors that can precisely quantify the presence of specific molecular species in real time without the need for labeling have seen increased use in the drug discovery industry and molecular biology in general. Of the many possible optical biosensors, the TM mode Si biosensor is shown to be very attractive in the sensing application because of large field amplitude on the surface and cost effective CMOS VLSI fabrication. Noise is the most fundamental factor that limits the performance of sensors in development of high-sensitivity biosensors, and noise reduction techniques require precise studies and analysis. One such example stems from thermal fluctuations. Generally SOI biosensors are vulnerable to ambient temperature fluctuations because of large thermo-optic coefficient of silicon (˜2x10 -4 RIU/K), typically requiring another reference ring and readout sequence to compensate temperature induced noise. To address this problem, we designed sensors with a novel TM-mode shallow-ridge waveguide that provides both large surface amplitude for bulk and surface sensing. With proper design, this also provides large optical confinement in the aqueous cladding that renders the device athermal using the negative thermo-optic coefficient of water (~ --1x10-4RIU/K), demonstrating cancellation of thermo-optic effects for aqueous solution operation near 300K. Additional limitations resulting from mechanical actuator fluctuations, stability of tunable lasers, and large 1/f noise of lasers and sensor electronics can limit biosensor performance. Here we also present a simple harmonic feedback readout technique that obviates the need for spectrometers and tunable lasers. This feedback technique reduces the impact of 1/f noise to enable high-sensitivity, and a DSP lock-in with 256 kHz sampling rate can provide down to micros time scale monitoring for fast transitions in biomolecular concentration with potential for small volume and low cost. In this dissertation, a novel
5. High-precision x-ray spectroscopy of highly charged ions with microcalorimeters
International Nuclear Information System (INIS)
Kraft-Bermuth, S; Andrianov, V; Bleile, A; Echler, A; Egelhof, P; Grabitz, P; Ilieva, S; Kiselev, O; Meier, J; Kilbourne, C; McCammon, D
2013-01-01
The precise determination of the energy of the Lyman α1 and α2 lines in hydrogen-like heavy ions provides a sensitive test of quantum electrodynamics in very strong Coulomb fields. To improve the experimental precision, the new detector concept of microcalorimeters is now exploited for such measurements. Such detectors consist of compensated-doped silicon thermistors and Pb or Sn absorbers to obtain high quantum efficiency in the energy range of 40–70 keV, where the Doppler-shifted Lyman lines are located. For the first time, a microcalorimeter was applied in an experiment to precisely determine the transition energy of the Lyman lines of lead ions at the experimental storage ring at GSI. The energy of the Ly α1 line E(Ly-α1, 207 Pb 81+ ) = (77937 ± 12 stat ± 25 syst ) eV agrees within error bars with theoretical predictions. To improve the experimental precision, a new detector array with more pixels and better energy resolution was equipped and successfully applied in an experiment to determine the Lyman-α lines of gold ions 197 Au 78+ . (paper)
6. Designing Metallic and Insulating Nanocrystal Heterostructures to Fabricate Highly Sensitive and Solution Processed Strain Gauges for Wearable Sensors.
Science.gov (United States)
Lee, Woo Seok; Lee, Seung-Wook; Joh, Hyungmok; Seong, Mingi; Kim, Haneun; Kang, Min Su; Cho, Ki-Hyun; Sung, Yun-Mo; Oh, Soong Ju
2017-12-01
All-solution processed, high-performance wearable strain sensors are demonstrated using heterostructure nanocrystal (NC) solids. By incorporating insulating artificial atoms of CdSe quantum dot NCs into metallic artificial atoms of Au NC thin film matrix, metal-insulator heterostructures are designed. This hybrid structure results in a shift close to the percolation threshold, modifying the charge transport mechanism and enhancing sensitivity in accordance with the site percolation theory. The number of electrical pathways is also manipulated by creating nanocracks to further increase its sensitivity, inspired from the bond percolation theory. The combination of the two strategies achieves gauge factor up to 5045, the highest sensitivity recorded among NC-based strain gauges. These strain sensors show high reliability, durability, frequency stability, and negligible hysteresis. The fundamental charge transport behavior of these NC solids is investigated and the combined site and bond percolation theory is developed to illuminate the origin of their enhanced sensitivity. Finally, all NC-based and solution-processed strain gauge sensor arrays are fabricated, which effectively measure the motion of each finger joint, the pulse of heart rate, and the movement of vocal cords of human. This work provides a pathway for designing low-cost and high-performance electronic skin or wearable devices. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
7. High sensitivity pyrogen testing in water and dialysis solutions.
Science.gov (United States)
Daneshian, Mardas; Wendel, Albrecht; Hartung, Thomas; von Aulock, Sonja
2008-07-20
The dialysis patient is confronted with hundreds of litres of dialysis solution per week, which pass the natural protective barriers of the body and are brought into contact with the tissue directly in the case of peritoneal dialysis or indirectly in the case of renal dialysis (hemodialysis). The components can be tested for living specimens or dead pyrogenic (fever-inducing) contaminations. The former is usually detected by cultivation and the latter by the endotoxin-specific Limulus Amoebocyte Lysate Assay (LAL). However, the LAL assay does not reflect the response of the human immune system to the wide variety of possible pyrogenic contaminations in dialysis fluids. Furthermore, the test is limited in its sensitivity to detect extremely low concentrations of pyrogens, which in their sum result in chronic pathologies in dialysis patients. The In vitro Pyrogen Test (IPT) employs human whole blood to detect the spectrum of pyrogens to which humans respond by measuring the release of the endogenous fever mediator interleukin-1beta. Spike recovery checks exclude interference. The test has been validated in an international study for pyrogen detection in injectable solutions. In this study we adapted the IPT to the testing of dialysis solutions. Preincubation of 50 ml spiked samples with albumin-coated microspheres enhanced the sensitivity of the assay to detect contaminations down to 0.1 pg/ml LPS or 0.001 EU/ml in water or saline and allowed pyrogen detection in dialysis concentrates or final working solutions. This method offers high sensitivity detection of human-relevant pyrogens in dialysis solutions and components.
8. Sensitivity of n-p scattering observables to charge-independence breaking of the 3P N-N phase shifts
International Nuclear Information System (INIS)
Tornow, W.; Walter, R.L.
1990-01-01
The sensitivity of neutron-proton scattering observables to the recently reported charge-independence breaking of the isospin T = 1 3 P nucleon-nucleon interaction has been calculated. It is shown that only the analyzing power A y (θ) at extreme forward angles and at θ = 90 o c.m. and the spin-correlation coefficient A zx (θ) at 90 o c.m. exhibit a measurable sensitivity. It is concluded that the determination of A y at 90 o c.m. is currently the most accurate approach to verify independently charge-independence breaking in the 3 P nucleon-nucleon phase shifts, considering the status of present experimental techniques. (Authors)
9. Luminescent Lanthanide Reporters for High-Sensitivity Novel Bioassays
Energy Technology Data Exchange (ETDEWEB)
Anstey, Mitchell R. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Fruetel, Julia A. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Foster, Michael E. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Hayden, Carl C. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Buckley, Heather L. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Arnold, John [Sandia National Lab. (SNL-CA), Livermore, CA (United States)
2013-09-01
Biological imaging and assay technologies rely on fluorescent organic dyes as reporters for a number of interesting targets and processes. However, limitations of organic dyes such as small Stokes shifts, spectral overlap of emission signals with native biological fluorescence background, and photobleaching have all inhibited the development of highly sensitive assays. To overcome the limitations of organic dyes for bioassays, we propose to develop lanthanide-based luminescent dyes and demonstrate them for molecular reporting applications. This relatively new family of dyes was selected for their attractive spectral and chemical properties. Luminescence is imparted by the lanthanide atom and allows for relatively simple chemical structures that can be tailored to the application. The photophysical properties offer unique features such as narrow and non-overlapping emission bands, long luminescent lifetimes, and long wavelength emission, which enable significant sensitivity improvements over organic dyes through spectral and temporal gating of the luminescent signal.Growth in this field has been hindered due to the necessary advanced synthetic chemistry techniques and access to experts in biological assay development. Our strategy for the development of a new lanthanide-based fluorescent reporter system is based on chelation of the lanthanide metal center using absorbing chromophores. Our first strategy involves "Click" chemistry to develop 3-fold symmetric chelators and the other involves use of a new class of tetrapyrrole ligands called corroles. This two-pronged approach is geared towards the optimization of chromophores to enhance light output.
10. New application of superconductors: High sensitivity cryogenic light detectors
Energy Technology Data Exchange (ETDEWEB)
Cardani, L., E-mail: laura.cardani@roma1.infn.it [Dipartimento di Fisica, Sapienza Università di Roma, Piazzale Aldo Moro 2, 00185 Roma (Italy); Physics Department, Princeton University, Washington Road, 08544 Princeton, NJ (United States); Bellini, F.; Casali, N. [Dipartimento di Fisica, Sapienza Università di Roma, Piazzale Aldo Moro 2, 00185 Roma (Italy); INFN – Sezione di Roma, Piazzale Aldo Moro 2, 00185 Roma, Italy (Italy); Castellano, M.G. [Istituto di Fotonica e Nanotecnologie – CNR, Via Cineto Romano 42, 00156 Roma (Italy); Colantoni, I.; Coppolecchia, A. [Dipartimento di Fisica, Sapienza Università di Roma, Piazzale Aldo Moro 2, 00185 Roma (Italy); Cosmelli, C.; Cruciani, A. [Dipartimento di Fisica, Sapienza Università di Roma, Piazzale Aldo Moro 2, 00185 Roma (Italy); INFN – Sezione di Roma, Piazzale Aldo Moro 2, 00185 Roma, Italy (Italy); D' Addabbo, A. [INFN – Laboratori Nazionali del Gran Sasso, Assergi (L' Aquila) 67010 (Italy); Di Domizio, S. [INFN – Sezione di Genova, Via Dodecaneso 33, 16146 Genova (Italy); Dipartimento di Fisica, Università degli Studi di Genova, Via Dodecaneso 33, 16146 Genova (Italy); Martinez, M. [Dipartimento di Fisica, Sapienza Università di Roma, Piazzale Aldo Moro 2, 00185 Roma (Italy); INFN – Sezione di Roma, Piazzale Aldo Moro 2, 00185 Roma, Italy (Italy); Laboratorio de Fisica Nuclear y Astroparticulas, Universidad de Zaragoza, Zaragoza 50009 (Spain); Tomei, C. [INFN – Sezione di Roma, Piazzale Aldo Moro 2, 00185 Roma, Italy (Italy); and others
2017-02-11
In this paper we describe the current status of the CALDER project, which is developing ultra-sensitive light detectors based on superconductors for cryogenic applications. When we apply an AC current to a superconductor, the Cooper pairs oscillate and acquire kinetic inductance, that can be measured by inserting the superconductor in a LC circuit with high merit factor. Interactions in the superconductor can break the Cooper pairs, causing sizable variations in the kinetic inductance and, thus, in the response of the LC circuit. The continuous monitoring of the amplitude and frequency modulation allows to reconstruct the incident energy with excellent sensitivity. This concept is at the basis of Kinetic Inductance Detectors (KIDs) that are characterized by natural aptitude to multiplexed read-out (several sensors can be tuned to different resonant frequencies and coupled to the same line), resolution of few eV, stable behavior over a wide temperature range, and ease in fabrication. We present the results obtained by the CALDER collaboration with 2×2 cm{sup 2} substrates sampled by 1 or 4 Aluminum KIDs. We show that the performances of the first prototypes are already competitive with those of other commonly used light detectors, and we discuss the strategies for a further improvement.
11. New application of superconductors: High sensitivity cryogenic light detectors
International Nuclear Information System (INIS)
Cardani, L.; Bellini, F.; Casali, N.; Castellano, M.G.; Colantoni, I.; Coppolecchia, A.; Cosmelli, C.; Cruciani, A.; D'Addabbo, A.; Di Domizio, S.; Martinez, M.; Tomei, C.
2017-01-01
In this paper we describe the current status of the CALDER project, which is developing ultra-sensitive light detectors based on superconductors for cryogenic applications. When we apply an AC current to a superconductor, the Cooper pairs oscillate and acquire kinetic inductance, that can be measured by inserting the superconductor in a LC circuit with high merit factor. Interactions in the superconductor can break the Cooper pairs, causing sizable variations in the kinetic inductance and, thus, in the response of the LC circuit. The continuous monitoring of the amplitude and frequency modulation allows to reconstruct the incident energy with excellent sensitivity. This concept is at the basis of Kinetic Inductance Detectors (KIDs) that are characterized by natural aptitude to multiplexed read-out (several sensors can be tuned to different resonant frequencies and coupled to the same line), resolution of few eV, stable behavior over a wide temperature range, and ease in fabrication. We present the results obtained by the CALDER collaboration with 2×2 cm"2 substrates sampled by 1 or 4 Aluminum KIDs. We show that the performances of the first prototypes are already competitive with those of other commonly used light detectors, and we discuss the strategies for a further improvement.
12. Operating modes of high-Tc composite superconductors and thermal runaway conditions under current charging
International Nuclear Information System (INIS)
Romanovskii, V R; Watanabe, K
2006-01-01
The operating thermal and electric modes of a high-T c superconducting composite in partially and fully penetrated states induced by the charging current are investigated. They were studied under conditions in which the current charging rate, the volume fraction of the superconductor in a composite or the temperature of the cooling bath were changed. The transient behaviour of the voltage-current dependence, which is characteristic during stable and unstable increases in electric field inside the composite under a continuous current charging, is discussed. Simulations were done using zero- and one-dimensional steady and unsteady thermoelectric models with a power equation describing the virgin voltage-current characteristic of a superconductor. It is found that some thermoelectric trends underlie the shape of the voltage-current characteristic of the high-T c superconducting composite. These have to be considered during experiments in which the critical or quench currents are defined. First, in the initial stage of the fully penetrated regime (in the low voltage range), the electric field distribution does not have a uniform character. These states depend on the volume fraction of the superconductor and the current charging rate: the higher these quantities, the higher the heterogeneity of the electric field. Second, during the stable over-critical regime (in the high voltage range) occurring in complete penetration modes, the evolution of the electric field may depend on the relevant temperature increase of a composite according to the corresponding increase in its temperature-dependent heat capacity. Consequently, the shape of the voltage-current characteristic of a composite high-T c superconductor during continuous current charging, both before and after thermal runaway, has only a positive slope. Moreover, it is proved that the growth of the fully penetrated part of the voltage-current characteristic becomes less intensive when the current charging rate or the
13. Intense highly charged ion beam production and operation with a superconducting electron cyclotron resonance ion source
Directory of Open Access Journals (Sweden)
H. W. Zhao
2017-09-01
Full Text Available The superconducting electron cyclotron resonance ion source with advanced design in Lanzhou (SECRAL is a superconducting-magnet-based electron cyclotron resonance ion source (ECRIS for the production of intense highly charged heavy ion beams. It is one of the best performing ECRISs worldwide and the first superconducting ECRIS built with an innovative magnet to generate a high strength minimum-B field for operation with heating microwaves up to 24–28 GHz. Since its commissioning in 2005, SECRAL has so far produced a good number of continuous wave intensity records of highly charged ion beams, in which recently the beam intensities of ^{40}Ar^{12+} and ^{129}Xe^{26+} have, for the first time, exceeded 1 emA produced by an ion source. Routine operations commenced in 2007 with the Heavy Ion accelerator Research Facility in Lanzhou (HIRFL, China. Up to June 2017, SECRAL has been providing more than 28,000 hours of highly charged heavy ion beams to the accelerator demonstrating its great capability and reliability. The great achievement of SECRAL is accumulation of numerous technical advancements, such as an innovative magnetic system and an efficient double-frequency (24+18 GHz heating with improved plasma stability. This article reviews the development of SECRAL and production of intense highly charged ion beams by SECRAL focusing on its unique magnet design, source commissioning, performance studies and enhancements, beam quality and long-term operation. SECRAL development and its performance studies representatively reflect the achievements and status of the present ECR ion source, as well as the ECRIS impacts on HIRFL.
14. Intense highly charged ion beam production and operation with a superconducting electron cyclotron resonance ion source
Science.gov (United States)
Zhao, H. W.; Sun, L. T.; Guo, J. W.; Lu, W.; Xie, D. Z.; Hitz, D.; Zhang, X. Z.; Yang, Y.
2017-09-01
The superconducting electron cyclotron resonance ion source with advanced design in Lanzhou (SECRAL) is a superconducting-magnet-based electron cyclotron resonance ion source (ECRIS) for the production of intense highly charged heavy ion beams. It is one of the best performing ECRISs worldwide and the first superconducting ECRIS built with an innovative magnet to generate a high strength minimum-B field for operation with heating microwaves up to 24-28 GHz. Since its commissioning in 2005, SECRAL has so far produced a good number of continuous wave intensity records of highly charged ion beams, in which recently the beam intensities of 40Ar+ and 129Xe26+ have, for the first time, exceeded 1 emA produced by an ion source. Routine operations commenced in 2007 with the Heavy Ion accelerator Research Facility in Lanzhou (HIRFL), China. Up to June 2017, SECRAL has been providing more than 28,000 hours of highly charged heavy ion beams to the accelerator demonstrating its great capability and reliability. The great achievement of SECRAL is accumulation of numerous technical advancements, such as an innovative magnetic system and an efficient double-frequency (24 +18 GHz ) heating with improved plasma stability. This article reviews the development of SECRAL and production of intense highly charged ion beams by SECRAL focusing on its unique magnet design, source commissioning, performance studies and enhancements, beam quality and long-term operation. SECRAL development and its performance studies representatively reflect the achievements and status of the present ECR ion source, as well as the ECRIS impacts on HIRFL.
15. Van-de-Graaf accelerator operation with laser source of highly-charged heavy ions
International Nuclear Information System (INIS)
Barabash, L.S.; Golubev, A.A.; Koshkarev, S.G.; Krechet, K.I.; Sharkov, B.Y.; Shumshurov, A.V.
1988-01-01
Multicharged ions (Z = +1 divided-by +10) of practically any elements of the periodical table have been generated by the laser source based on a simple in operation and fabrication laser. One of the features of the laser source is that the energy needed for plasma heating is transported to the target from a great distance. In this case the target can be placed under high voltage or in a magnetic field. These advantages of the laser source are particularly important for its application in the Van-de-Graaf accelerator, where absence of resonance units allows to accelerate ions with any charge-to-mass ratio. The goal of this paper consists in designing a laser source of highly- charged heavy ions in the Van-de-Graaf accelerator and in measuring charge spectra of the accelerated ion beam. The peculiarities of this accelerator are taken into account in the discussion of the source scheme. Such peculiarities include potential up to 5 MV on the high-voltage conductor, where the ion source is placed, and high up to 15 atm gas environment pressure
16. Charge injection engineering of ambipolar field-effect transistors for high-performance organic complementary circuits.
Science.gov (United States)
Baeg, Kang-Jun; Kim, Juhwan; Khim, Dongyoon; Caironi, Mario; Kim, Dong-Yu; You, In-Kyu; Quinn, Jordan R; Facchetti, Antonio; Noh, Yong-Young
2011-08-01
Ambipolar π-conjugated polymers may provide inexpensive large-area manufacturing of complementary integrated circuits (CICs) without requiring micro-patterning of the individual p- and n-channel semiconductors. However, current-generation ambipolar semiconductor-based CICs suffer from higher static power consumption, low operation frequencies, and degraded noise margins compared to complementary logics based on unipolar p- and n-channel organic field-effect transistors (OFETs). Here, we demonstrate a simple methodology to control charge injection and transport in ambipolar OFETs via engineering of the electrical contacts. Solution-processed caesium (Cs) salts, as electron-injection and hole-blocking layers at the interface between semiconductors and charge injection electrodes, significantly decrease the gold (Au) work function (∼4.1 eV) compared to that of a pristine Au electrode (∼4.7 eV). By controlling the electrode surface chemistry, excellent p-channel (hole mobility ∼0.1-0.6 cm(2)/(Vs)) and n-channel (electron mobility ∼0.1-0.3 cm(2)/(Vs)) OFET characteristics with the same semiconductor are demonstrated. Most importantly, in these OFETs the counterpart charge carrier currents are highly suppressed for depletion mode operation (I(off) 0.1-0.2 mA). Thus, high-performance, truly complementary inverters (high gain >50 and high noise margin >75% of ideal value) and ring oscillators (oscillation frequency ∼12 kHz) based on a solution-processed ambipolar polymer are demonstrated.
17. Fragile charge order in the nonsuperconducting ground state of the underdoped high-temperature superconductors.
Science.gov (United States)
Tan, B S; Harrison, N; Zhu, Z; Balakirev, F; Ramshaw, B J; Srivastava, A; Sabok-Sayr, S A; Sabok, S A; Dabrowski, B; Lonzarich, G G; Sebastian, Suchitra E
2015-08-04
The normal state in the hole underdoped copper oxide superconductors has proven to be a source of mystery for decades. The measurement of a small Fermi surface by quantum oscillations on suppression of superconductivity by high applied magnetic fields, together with complementary spectroscopic measurements in the hole underdoped copper oxide superconductors, point to a nodal electron pocket from charge order in YBa2Cu3(6+δ). Here, we report quantum oscillation measurements in the closely related stoichiometric material YBa2Cu4O8, which reveals similar Fermi surface properties to YBa2Cu3(6+δ), despite the nonobservation of charge order signatures in the same spectroscopic techniques, such as X-ray diffraction, that revealed signatures of charge order in YBa2Cu3(6+δ). Fermi surface reconstruction in YBa2Cu4O8 is suggested to occur from magnetic field enhancement of charge order that is rendered fragile in zero magnetic fields because of its potential unconventional nature and/or its occurrence as a subsidiary to more robust underlying electronic correlations.
18. Interaction of low-energy highly charged ions with matter; Wechselwirkung niederenergetischer hochgeladener Ionen mit Materie
Energy Technology Data Exchange (ETDEWEB)
Ginzel, Rainer
2010-06-09
The thesis presented herein deals with experimental studies of the interaction between highly charged ions and neutral matter at low collision energies. The energy range investigated is of great interest for the understanding of both charge exchange reactions between ions comprising the solar wind and various astrophysical gases, as well as the creation of near-surface nanostructures. Over the course of this thesis an experimental setup was constructed, capable of reducing the kinetic energy of incoming ions by two orders of magnitude and finally focussing the decelerated ion beam onto a solid or gaseous target. A coincidence method was employed for the simultaneous detection of photons emitted during the charge exchange process together with the corresponding projectile ions. In this manner, it was possible to separate reaction channels, whose superposition presumably propagated large uncertainties and systematic errors in previous measurements. This work has unveiled unexpectedly strong contributions of slow radiative decay channels and clear evidence of previously only postulated decay processes in charge exchange-induced X-ray spectra. (orig.)
19. Exploring charge density analysis in crystals at high pressure: data collection, data analysis and advanced modelling.
Science.gov (United States)
Casati, Nicola; Genoni, Alessandro; Meyer, Benjamin; Krawczuk, Anna; Macchi, Piero
2017-08-01
The possibility to determine electron-density distribution in crystals has been an enormous breakthrough, stimulated by a favourable combination of equipment for X-ray and neutron diffraction at low temperature, by the development of simplified, though accurate, electron-density models refined from the experimental data and by the progress in charge density analysis often in combination with theoretical work. Many years after the first successful charge density determination and analysis, scientists face new challenges, for example: (i) determination of the finer details of the electron-density distribution in the atomic cores, (ii) simultaneous refinement of electron charge and spin density or (iii) measuring crystals under perturbation. In this context, the possibility of obtaining experimental charge density at high pressure has recently been demonstrated [Casati et al. (2016). Nat. Commun. 7, 10901]. This paper reports on the necessities and pitfalls of this new challenge, focusing on the species syn-1,6:8,13-biscarbonyl[14]annulene. The experimental requirements, the expected data quality and data corrections are discussed in detail, including warnings about possible shortcomings. At the same time, new modelling techniques are proposed, which could enable specific information to be extracted, from the limited and less accurate observations, like the degree of localization of double bonds, which is fundamental to the scientific case under examination.
20. Controlling the directionality of charge transfer in phthalocyaninato zinc sensitizer for a dye-sensitized solar cell: density functional theory studies.
Science.gov (United States)
Wan, Liang; Qi, Dongdong; Zhang, Yuexing; Jiang, Jianzhuang
2011-01-28
Density functional theory (DFT) calculation on the molecular structures, charge distribution, molecular orbitals, electronic absorption spectra of a series of eight unsymmetrical phthalocyaninato zinc complexes with one peripheral (E)-2-cyano-3-(5-vinylthiophen-2-yl) acrylic acid substituent at 2 or 3 position as an electron-withdrawing group and a different number of electron-donating amino groups at the remaining peripheral positions (9, 10, 16, 17, 23, 24) of the phthalocyanine ring, namely ZnPc-β-A, ZnPc-β-A-I-NH(2), ZnPc-β-A-II-NH(2), ZnPc-β-A-III-NH(2), ZnPc-β-A-I,II-NH(2), ZnPc-β-A-I,III-NH(2), ZnPc-β-A-II,III-NH(2), and ZnPc-β-A-I,II,III-NH(2), reveals the effects of amino groups on the charge transfer properties of these phthalocyanine derivatives with a typical D-π-A electronic structure. The introduction of amino groups was revealed altering of the atomic charge distribution, lifting the frontier molecular orbital level, red-shift of the near-IR bands in the electronic absorption spectra, and finally resulting in enhanced charge transfer directionality for the phthalocyanine compounds. Along with the increase of the peripheral amino groups at the phthalocyanine ring from 0, 2, 4, to 6, the dihedral angle between the phthalocyanine ring and the average plane of the (E)-2-cyano-3-(5-vinylthiophen-2-yl) acrylic acid substituent increases from 0 to 3.3° in an irregular manner. This is in good contrast to the regular and significant change in the charge distribution, destabilization of frontier orbital energies, and red shift of near-IR bands of phthalocyanine compounds along the same order. In addition, comparative studies indicate the smaller effect of incorporating two amino groups onto the 16 and 17 than on 9 and 10 or 23 and 24 peripheral positions of the phthalocyanine ring onto the aforementioned electronic properties, suggesting the least effect on tuning the charge transfer property of the phthalocyanine compound via introducing two
1. High-Sensitivity AGN Polarimetry at Sub-Millimeter Wavelengths
Directory of Open Access Journals (Sweden)
Ivan Martí-Vidal
2017-10-01
Full Text Available The innermost regions of radio loud Active Galactic Nuclei (AGN jets are heavily affected by synchrotron self-absorption, due to the strong magnetic fields and high particle densities in these extreme zones. The only way to overcome this absorption is to observe at sub-millimeter wavelengths, although polarimetric observations at such frequencies have so far been limited by sensitivity and calibration accuracy. However, new generation instruments such as the Atacama Large mm/sub-mm Array (ALMA overcome these limitations and are starting to deliver revolutionary results in the observational studies of AGN polarimetry. Here we present an overview of our state-of-the-art interferometric mm/sub-mm polarization observations of AGN jets with ALMA (in particular, the gravitationally-lensed sources PKS 1830−211 and B0218+359, which allow us to probe the magneto-ionic conditions at the regions closest to the central black holes.
2. High resolution, position sensitive detector for energetic particle beams
International Nuclear Information System (INIS)
Marsh, E.P.; Strathman, M.D.; Reed, D.A.; Odom, R.W.; Morse, D.H.; Pontau, A.E.
1993-01-01
The performance and design of an imaging position sensitive, particle beam detector will be presented. The detector is minimally invasive, operates a wide dynamic range (>10 10 ), and exhibits high spatial resolution. The secondary electrons produced when a particle beam passes through a thin foil are imaged using stigmatic ion optics onto a two-dimensional imaging detector. Due to the low scattering cross section of the 6 nm carbon foil the detector is a minimal perturbation on the primary beam. A prototype detector with an image resolution of approximately 5 μm for a field of view of 1 mm has been reported. A higher resolution detector for imaging small beams (<50 μm) with an image resolution of better than 0.5 μm has since been developed and its design is presented. (orig.)
3. High resolution, position sensitive detector for energetic particle beams
Energy Technology Data Exchange (ETDEWEB)
Marsh, E P [Charles Evans and Associates, Redwood City, CA (United States); Strathman, M D [Charles Evans and Associates, Redwood City, CA (United States); Reed, D A [Charles Evans and Associates, Redwood City, CA (United States); Odom, R W [Charles Evans and Associates, Redwood City, CA (United States); Morse, D H [Sandia National Labs., Livermore, CA (United States); Pontau, A E [Sandia National Labs., Livermore, CA (United States)
1993-05-01
The performance and design of an imaging position sensitive, particle beam detector will be presented. The detector is minimally invasive, operates a wide dynamic range (>10[sup 10]), and exhibits high spatial resolution. The secondary electrons produced when a particle beam passes through a thin foil are imaged using stigmatic ion optics onto a two-dimensional imaging detector. Due to the low scattering cross section of the 6 nm carbon foil the detector is a minimal perturbation on the primary beam. A prototype detector with an image resolution of approximately 5 [mu]m for a field of view of 1 mm has been reported. A higher resolution detector for imaging small beams (<50 [mu]m) with an image resolution of better than 0.5 [mu]m has since been developed and its design is presented. (orig.)
4. Highly Sensitive Filter Paper Substrate for SERS Trace Explosives Detection
Directory of Open Access Journals (Sweden)
2012-01-01
Full Text Available We report on a novel and extremely low-cost surface-enhanced Raman spectroscopy (SERS substrate fabricated depositing gold nanoparticles on common lab filter paper using thermal inkjet technology. The paper-based substrate combines all advantages of other plasmonic structures fabricated by more elaborate techniques with the dynamic flexibility given by the inherent nature of the paper for an efficient sample collection, robustness, and stability. We describe the fabrication, characterization, and SERS activity of our substrate using 2,4,6-trinitrotoluene, 2,4-dinitrotoluene, and 1,3,5-trinitrobenzene as analytes. The paper-based SERS substrates presented a high sensitivity and excellent reproducibility for analytes employed, demonstrating a direct application in forensic science and homeland security.
5. High efficiency solid-state sensitized heterojunction photovoltaic device
KAUST Repository
Wang, Mingkui
2010-06-01
The high molar extinction coefficient heteroleptic ruthenium dye, NaRu(4,4′-bis(5-(hexylthio)thiophen-2-yl)-2,2′-bipyridine) (4-carboxylic acid-4′-carboxylate-2,2′-bipyridine) (NCS) 2, exhibits certified 5% electric power conversion efficiency at AM 1.5 solar irradiation (100 mW cm-2) in a solid-state dye-sensitized solar cell using 2,2′,7,7′-tetrakis-(N,N-di-pmethoxyphenylamine)-9, 9′-spirobifluorene (spiro-MeOTAD) as the organic hole-transporting material. This demonstration elucidates a class of photovoltaic devices with potential for low-cost power generation. © 2010 Elsevier Ltd. All rights reserved.
6. High efficiency solid-state sensitized heterojunction photovoltaic device
KAUST Repository
Wang, Mingkui; Liu, Jingyuan; Cevey-Ha, Ngoc-Le; Moon, Soo-Jin; Liska, Paul; Humphry-Baker, Robin; Moser, Jacques-E.; Grä tzel, Carole; Wang, Peng; Zakeeruddin, Shaik M.
2010-01-01
The high molar extinction coefficient heteroleptic ruthenium dye, NaRu(4,4′-bis(5-(hexylthio)thiophen-2-yl)-2,2′-bipyridine) (4-carboxylic acid-4′-carboxylate-2,2′-bipyridine) (NCS) 2, exhibits certified 5% electric power conversion efficiency at AM 1.5 solar irradiation (100 mW cm-2) in a solid-state dye-sensitized solar cell using 2,2′,7,7′-tetrakis-(N,N-di-pmethoxyphenylamine)-9, 9′-spirobifluorene (spiro-MeOTAD) as the organic hole-transporting material. This demonstration elucidates a class of photovoltaic devices with potential for low-cost power generation. © 2010 Elsevier Ltd. All rights reserved.
7. Nanoscale transformation of sp2 to sp3 of graphite by slow highly charged ion irradiation
International Nuclear Information System (INIS)
Meguro, T.; Hida, A.; Koguchi, Y.; Miyamoto, S.; Yamamoto, Y.; Takai, H.; Maeda, K.; Aoyagi, Y.
2003-01-01
Nanoscale transformation of electronic states by highly charged ion (HCI) impact on graphite surfaces is described. The high potential energy of slow HCI, which induces multiple emission of electrons from the surface, provides a strong modification of the electronic states of the local area upon graphite surfaces. The HCI impact and the subsequent surface treatment either by electron injection from a scanning tunneling microscopy tip or by He-Cd laser irradiation induce a localized transition from sp 2 to sp 3 hybridization in graphite, resulting in the formation of nanoscale diamond-like structures (nanodiamond) at the impact region. From Raman spectroscopic measurements on sp 2 related peaks, it is found that the HCI irradiation creates vacancy complexes in contrast to ions having a lower charge state, which generate single vacancies. It is of interest that a single impact of HCI creates one nanodiamond structure, suggesting potential applications of HCI in nanoscale material processing
8. Near UV-visible line emission from tungsten highly-charged ions in Large Helical Device
International Nuclear Information System (INIS)
Kato, D.; Sakaue, H.A.; Murakami, I.; Goto, M.; Oishi, T.; Morita, S.; Fujii, K.; Nakamura, N.; Koike, F.; Sasaki, Akira; Ding, X.-B.; Dong, C.-Z.
2015-01-01
Wavelengths of emission lines from tungsten highly-charged ions have been precisely measured in near UV-visible range (320 - 356 nm and 382 - 402 nm) at Large Helical Device (LHD) by tungsten pellet injection. The tungsten emission lines were assigned based on its line-integrated intensity profiles on a poloidal cross section. The ground-term magnetic-dipole (M1) lines of W 26+,27+ and an M1 line of a metastable excited state of W 28+ , whose wavelengths have been determined by measurements using electron-beam-ion-traps (EBITs), are identified in the LHD spectra. The present results partially compliment wavelength data of tungsten highly-charged ions in the near UV-visible range. (author)
9. The Frankfurt ECRIS-RFQ facility for materials research with highly charged ions
International Nuclear Information System (INIS)
Stiebing, K.; Streitz, H.; Schmidt, L.; Schremmer, A.; Bethge, K.; Schmidt-Boecking, H.; Schempp, A.; Bessler, U.; Beller, P.; Madlung, J.
1996-01-01
The new accelerator for the production of highly charged heavy ions, presently installed at the Institut fuer Kernphysik consists of a 14 GHz ECR source in combination with an variable-energy RFQ post-accelerator. It is designed to deliver highly charged ions in the energy range between 1 keV/u (the ECRIS beam) and 100-200 keV/u with the (variable-energy radio frequency quadrupole) VE-RFQ. Investigations of transient processes with ns time constants will be possible by a single bunch system. Another attractive feature for materials research is the combination with ion beams from the 7 MV Van de Graaff. The status of the project and first results of beam measurements will be pre sented. (orig.)
10. High-speed scattering of charged and uncharged particles in general relativity
International Nuclear Information System (INIS)
Westphal, K.
1985-01-01
After a brief consideration of the high-speed scattering of two point charges high-speed scattering is thoroughly discussed for a charged particle by a fixed mass and of two uncharged particles of comparable masses. Perturbation technique is used over Minkowski spacetime in the de Donder gauge and the field equations and the resulting equations of motion (which take the reaction of the particles' quasistatic self-field into account) are solved by iteration. The obtained energy-momentum conservation laws allow the computation of second-order corrections for the scattering angle and the cross section. The asymptotic structure of the far-field indicates synchrotron radiation (electromagnetic and gravitational, respectively) which causes an energy loss whose reaction on the motion is briefly considered in the low-velocity limit including bound motion. (For neutral particles this is a third-order effect.) (author)
11. High-energy charged particle bursts in the near-Earth space as earthquake precursors
Directory of Open Access Journals (Sweden)
S. Yu. Aleksandrin
2003-02-01
Full Text Available The experimental data on high-energy charged particle fluxes, obtained in various near-Earth space experiments (MIR orbital station, METEOR-3, GAMMA and SAMPEX satellites were processed and analyzed with the goal to search for particle bursts. Particle bursts have been selected in every experiment considered. It was shown that the significant part of high-energy charged particle bursts correlates with seismic activity. Moreover, the particle bursts are observed several hours before strong earthquakes; L-shells of particle bursts and corresponding earthquakes are practically the same. Some features of a seismo-magnetosphere connection model, based on the interaction of electromagnetic emission of seismic origin and radiation belt particles, were considered. Key words. Ionospheric physics (energetic particles, trapped; energetic particles, precipitating; magnetosphere-ionosphere interactions
12. On-chip high-voltage generator design design methodology for charge pumps
CERN Document Server
Tanzawa, Toru
2016-01-01
This book provides various design techniques for switched-capacitor on-chip high-voltage generators, including charge pump circuits, regulators, level shifters, references, and oscillators. Readers will see these techniques applied to system design in order to address the challenge of how the on-chip high-voltage generator is designed for Flash memories, LCD drivers, and other semiconductor devices to optimize the entire circuit area and power efficiency with a low voltage supply, while minimizing the cost. This new edition includes a variety of useful updates, including coverage of power efficiency and comprehensive optimization methodologies for DC-DC voltage multipliers, modeling of extremely low voltage Dickson charge pumps, and modeling and optimum design of AC-DC switched-capacitor multipliers for energy harvesting and power transfer for RFID.
13. Charge exchange as a recombination mechanism in high-temperature plasmas
International Nuclear Information System (INIS)
Hulse, R.A.; Post, D.E.; Mikkelsen, D.R.
1980-03-01
Charge exchange with neutral hydrogen is examined as a recombination mechanism for multi-charged impurity ions present in high-temperature fusion plasmas. At sufficiently low electron densities, fluxes of atomic hydrogen produced by either the injection of neutral heating beams or the background of thermal neutrals can yield an important or even dominant recombination process for such ions. Equilibrium results are given for selected impurity elements showing the altered ionization balance and radiative cooling rate produced by the presence of various neutral populations. A notable result is that the stripping of impurities to relatively non-radiative ionization states with increasing electron temperature can be postponed or entirely prevented by the application of intense neutral beam heating power. A time dependent calculation modelling the behavior of iron in recent PLT tokamak high power neutral beam heating experiments is also presented
14. Effective dose calculation in CT using high sensitivity TLDs
International Nuclear Information System (INIS)
2010-01-01
Full text: To determine the effective dose for common paediatric CT examinations using thermoluminescence dosimetry (TLD) mea surements. High sensitivity TLD chips (LiF:Mg,Cu,P, TLD-IOOH, Thermo Fisher Scientific, Waltham, MA) were calibrated on a linac at an energy of 6 MY. A calibration was also performed on a superricial X-ray unit at a kilovoltage energy to validate the megavoltage cali bration for the purpose of measuring doses in the diagnostic energy range. The dose variation across large organs was assessed and a methodology for TLD placement in a 10 year old anthropomorphic phantom developed. Effective dose was calculated from the TLD measured absorbed doses for typical CT examinations after correcting for the TLD energy response and taking into account differences in the mass energy absorption coefficients for different tissues and organs. Results Using new tissue weighting factors recommended in ICRP Publication 103, the effective dose for a CT brain examination on a 10 year old was 1.6 millisieverts (mSv), 4.9 mSv for a CT chest exa ination and 4.7 mSv for a CT abdomen/pelvis examination. These values are lower for the CT brain examination, higher for the CT chest examination and approximately the same for the CT abdomen/ pelvis examination when compared with effective doses calculated using ICRP Publication 60 tissue weighting factors. Conclusions High sensitivity TLDs calibrated with a radiotherapy linac are useful for measuring dose in the diagnostic energy range and overcome limitations of output reproducibility and uniformity asso ciated with traditional TLD calibration on CT scanners or beam quality matched diagnostic X-ray units.
15. Electron yield from Be-Cu induced by highly charged Xe q+ ions
Czech Academy of Sciences Publication Activity Database
Krása, Josef; Láska, Leoš; Stöckli, M. P.; Fehrenbach, C. W.
2002-01-01
Roč. 196, - (2002), s. 61-67 ISSN 0168-583X R&D Projects: GA AV ČR IAA1010105; GA MŠk LN00A100 Institutional research plan: CEZ:AV0Z1010921 Keywords : highly charged ion-induced electron emission * angle impact effect * Be-Cu Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.158, year: 2002
16. Two and three electron Auger transitions in collisions of highly-charged ions with surfaces
International Nuclear Information System (INIS)
Moretto-Capelle, P.; Bordenave-Montesquieu, A.; Benoit-Cattin, P.; Andriamonje, S.; Andrae, H.J.
1991-01-01
The Auger electron spectra from Ar 9+ approaching at 265 eV a Si or metal surface in vacua of 10 -5 Pa or UHV are identical. Experiments on atomic physics in front of surfaces are thus possible in standard vacuum. N 7+ approaching a surface at 1000 eV penetrates with great probability into the bulk and gives rise to K 2 L 2 L double Auger lines, observed for the first time with low energy highly charged ions. (orig.)
17. The charge deposition in the numerical simulation of high-current beam
International Nuclear Information System (INIS)
Wang Shijun
1987-01-01
A new method of charge deposition of high-current beam, conservation-map method, is given. THe advantages of Neil's and other various methods are adopted. The mistake of Neil's method and the limitation of other various methods is discarded. So the method is accurate without additional assumption. The method not only applies to the case of steady laminar flow but also applies to the case of steady non-laminar flow
18. Charge-coupled devices for particle detection with high spatial resolution
International Nuclear Information System (INIS)
Farley, F.J.; Damerell, C.J.S.; Gillman, A.R.; Wickens, F.J.
1980-10-01
The results of a study of the possible application of a thin microelectronic device (the charge-coupled device) to high energy physics as particle detectors with good spatial resolution which can distinguish between tracks emerging from the primary vertex and those from secondary vertices due to the decay of short lived particles with higher flavours, are reported. Performance characteristics indicating the spatial resolution, particle discrimination, time resolution, readout time and lifetime of such detectors have been obtained. (U.K.)
19. K-Vacancy Production in the Collision of Highly Charged Relativistic Ions With Heavy Atoms
OpenAIRE
KHABIBULLAEV, P. K.
2014-01-01
A general expression for the cross section of the inelastic collision of relativistic highly charged ion with heavy (relativistic) atoms is obtained using the generalized eikonal approximation. In the ultrarelativistic limit, the obtained formula coincides with a known exact one. As an application of the obtained result, probability and cross section of the K-vacany production in the U92+ - U91+ collision are calculated.
20. Advancement of highly charged ion beam production by superconducting ECR ion source SECRAL (invited)
International Nuclear Information System (INIS)
Sun, L.; Lu, W.; Zhang, W. H.; Feng, Y. C.; Qian, C.; Ma, H. Y.; Zhang, X. Z.; Zhao, H. W.; Guo, J. W.; Yang, Y.; Fang, X.
2016-01-01
At Institute of Modern Physics (IMP), Chinese Academy of Sciences (CAS), the superconducting Electron Cyclotron Resonance (ECR) ion source SECRAL (Superconducting ECR ion source with Advanced design in Lanzhou) has been put into operation for about 10 years now. It has been the main working horse to deliver intense highly charged heavy ion beams for the accelerators. Since its first plasma at 18 GHz, R&D work towards more intense highly charged ion beam production as well as the beam quality investigation has never been stopped. When SECRAL was upgraded to its typical operation frequency 24 GHz, it had already showed its promising capacity of very intense highly charged ion beam production. And it has also provided the strong experimental support for the so called scaling laws of microwave frequency effect. However, compared to the microwave power heating efficiency at 18 GHz, 24 GHz microwave heating does not show the ω 2 scale at the same power level, which indicates that microwave power coupling at gyrotron frequency needs better understanding. In this paper, after a review of the operation status of SECRAL with regard to the beam availability and stability, the recent study of the extracted ion beam transverse coupling issues will be discussed, and the test results of the both TE 01 and HE 11 modes will be presented. A general comparison of the performance working with the two injection modes will be given, and a preliminary analysis will be introduced. The latest results of the production of very intense highly charged ion beams, such as 1.42 emA Ar 12+ , 0.92 emA Xe 27+ , and so on, will be presented
1. Space charge and wake field analysis for a high brightness electron source
International Nuclear Information System (INIS)
Parsa, Z.
1991-01-01
We present a brief overview of the formalism used, and some simulation results for transverse and longitudinal motion of a bunch of particles moving through a cavity (e.g., the Brookhaven National Laboratory high brightness photocathode gun), including effects of the accelerating field, space charge forces (e.g., arising from the interaction of the cavity surface and the self field of the bunch). 3 refs., 12 figs
2. Extreme ultraviolet spectroscopy of highly charged argon ions at the Berlin EBIT
International Nuclear Information System (INIS)
Biedermann, C; Radtke, R; Fussmann, G; Allen, F I
2007-01-01
Extreme ultraviolet radiation from highly charged argon was investigated at the Berlin Electron Beam Ion Trap with a 2 m grazing incidence spectrometer. Lines in the wavelength range 150 to 660 A originating from C-like Ar 12+ to Li-like Ar 15+ ions have been identified and are compared with database information from solar line lists and predictions. Line ratios for the observed resonance, intercombination and forbidden lines offer important diagnostic capabilities for low density, hot plasmas
3. High-energy charged particles in space at one astronomical unit
International Nuclear Information System (INIS)
Feynman, J.; Gabriel, S.B.
1996-01-01
Single-event effects and many other spacecraft anomalies are caused by positively charged high-energy particles impinging on the vehicle and its component parts. Here, the authors review the current knowledge of the interplanetary particle environment in the energy ranges that are most important for these effects. State-of-the-art engineering models are described briefly along with comments on the future work required in this field
4. Scanning Auger microscopy for high lateral and depth elemental sensitivity
Energy Technology Data Exchange (ETDEWEB)
Martinez, E., E-mail: eugenie.martinez@cea.fr [CEA, LETI, MINATEC Campus, 17 rue des Martyrs, 38054 Grenoble Cedex 9 (France); Yadav, P. [CEA, LETI, MINATEC Campus, 17 rue des Martyrs, 38054 Grenoble Cedex 9 (France); Bouttemy, M. [Institut Lavoisier de Versailles, 45 av. des Etats-Unis, 78035 Versailles Cedex (France); Renault, O.; Borowik, Ł.; Bertin, F. [CEA, LETI, MINATEC Campus, 17 rue des Martyrs, 38054 Grenoble Cedex 9 (France); Etcheberry, A. [Institut Lavoisier de Versailles, 45 av. des Etats-Unis, 78035 Versailles Cedex (France); Chabli, A. [CEA, LETI, MINATEC Campus, 17 rue des Martyrs, 38054 Grenoble Cedex 9 (France)
2013-12-15
Highlights: •SAM performances and limitations are illustrated on real practical cases such as the analysis of nanowires and nanodots. •High spatial elemental resolution is shown with the analysis of reference semiconducting Al{sub 0.7}Ga{sub 0.3}As/GaAs multilayers. •High in-depth elemental resolution is also illustrated. Auger depth profiling with low energy ion beams allows revealing ultra-thin layers (∼1 nm). •Analysis of cross-sectional samples is another effective approach to obtain in-depth elemental information. -- Abstract: Scanning Auger microscopy is currently gaining interest for investigating nanostructures or thin multilayers stacks developed for nanotechnologies. New generation Auger nanoprobes combine high lateral (∼10 nm), energy (0.1%) and depth (∼2 nm) resolutions thus offering the possibility to analyze the elemental composition as well as the chemical state, at the nanometre scale. We report here on the performances and limitations on practical examples from nanotechnology research. The spatial elemental sensitivity is illustrated with the analysis of Al{sub 0.7}Ga{sub 0.3}As/GaAs heterostructures, Si nanowires and SiC nanodots. Regarding the elemental in-depth composition, two effective approaches are presented: low energy depth profiling to reveal ultra-thin layers (∼1 nm) and analysis of cross-sectional samples.
5. Improved charge-coupled device detectors for high-speed, charge exchange spectroscopy studies on the DIII-D tokamak
International Nuclear Information System (INIS)
Burrell, K.H.; Gohil, P.; Groebner, R.J.; Kaplan, D.H.; Robinson, J.I.; Solomon, W.M.
2004-01-01
Charge exchange spectroscopy is one of the key ion diagnostics on the DIII-D tokamak. It allows determination of ion temperature, poloidal and toroidal velocity, impurity density, and radial electric field E r throughout the plasma. For the 2003 experimental campaign, we replaced the intensified photodiode array detectors on the central portion of the DIII-D charge exchange spectroscopy system with advanced charge-coupled device (CCD) detectors mounted on faster (f/4.7) Czerny-Turner spectrometers equipped with toroidal mirrors. The CCD detectors are improved versions of the ones installed on our edge system in 1999. The combination improved the photoelectron signal level by about a factor of 20 and the signal to noise by a factor of 2-8, depending on the absolute signal level. The new cameras also allow shorter minimum integration times while archiving to PC memory: 0.552 ms for the slower, lower-read noise (15 e) readout mode and 0.274 ms in the faster, higher-read noise (30 e) mode
6. Channel mobility degradation and charge trapping in high-k/metal gate NMOSFETs
International Nuclear Information System (INIS)
Mathew, Shajan; Bera, L.K.; Balasubramanian, N.; Joo, M.S.; Cho, B.J.
2004-01-01
NMOSFETs with Metalo-Organic Chemical Vapor Deposited (MOCVD) HfAlO gate dielectric and TiN metal gate have been fabricated. Channel electron mobility was measured using the split-CV method and compared with SiO 2 devices. All high-k devices showed lower mobility compared with SiO 2 reference devices. High-k MOSFETs exhibited significant charge trapping and threshold instability. Threshold voltage recovery with time was studied on devices with oxide/nitride interfacial layer between high-k film and silicon substrate
7. Proceedings of the workshop on opportunities for atomic physics using slow, highly-charged ions
Energy Technology Data Exchange (ETDEWEB)
1987-01-01
The study of atomic physics with highly-charged ions is an area of intense activity at the present time because of a convergence of theoretical interest and advances in experimental techniques. The purpose of the Argonne ''Workshop on Opportunities for Atomic Physics Using Slow, Highly-Charged Ions'' was to bring together atomic, nuclear, and accelerator physicists in order to identify what new facilities would be most useful for the atomic physics community. The program included discussion of existing once-through machines, advanced ion sources, recoil ion techniques, ion traps, and cooler rings. One of the topics of the Workshop was to discuss possible improvement to the ANL Tandem-Linac facility (ATLAS) to enhance the capability for slowing down ions after they are stripped to a high-charge state (the Accel/Decel technique). Another topic was the opportunity for atomic physics provided by the ECR ion source which is being built for the Uranium Upgrade of ATLAS. 18 analytics were prepared for the individual papers in this volume.
8. Experiments with highly-charged heavy-ions performed at the storage ring ESR
International Nuclear Information System (INIS)
Mokler, P.H.
1992-01-01
The new heavy ion accelerator facility SIS/ESR was inaugurated in April 1990. During 1991 the experimental storage ring, ESR, has been commissioned. Highly-charged heavy ions from O 8+ up to Bi 82+ were successfully accumulated, cooled, and stored in the ring. Now all highly-charged, heavy ions can be provided for experiments at comfortable storage times and at energies roughly between 100 and 500 MeV/u. A report on the achievements and on the first experimental results will be given. For the experiments, special emphasis is put on capture processes in the electron cooler, i.e. on radiative and dielectronic recombination processes as well as on capture events of bound target electrons from a gas jet. In this case, the capture leads either directly (REC) or by cascading to X-ray emission, which is also exploited for a precision spectroscopy of the structure of the heaviest ions. Another exciting topic is the radioactive decay of highly charged ions: For instance the β-decay into bound atomic states, which is not possible for neutral atoms, was studied for stored naked Dy ions. (orig.)
9. Proceedings of the workshop on opportunities for atomic physics using slow, highly-charged ions
International Nuclear Information System (INIS)
1987-01-01
The study of atomic physics with highly-charged ions is an area of intense activity at the present time because of a convergence of theoretical interest and advances in experimental techniques. The purpose of the Argonne ''Workshop on Opportunities for Atomic Physics Using Slow, Highly-Charged Ions'' was to bring together atomic, nuclear, and accelerator physicists in order to identify what new facilities would be most useful for the atomic physics community. The program included discussion of existing once-through machines, advanced ion sources, recoil ion techniques, ion traps, and cooler rings. One of the topics of the Workshop was to discuss possible improvement to the ANL Tandem-Linac facility (ATLAS) to enhance the capability for slowing down ions after they are stripped to a high-charge state (the Accel/Decel technique). Another topic was the opportunity for atomic physics provided by the ECR ion source which is being built for the Uranium Upgrade of ATLAS. 18 analytics were prepared for the individual papers in this volume
10. Charge Modulation in Graphitic Carbon Nitride as a Switchable Approach to High-Capacity Hydrogen Storage.
Science.gov (United States)
Tan, Xin; Kou, Liangzhi; Tahini, Hassan A; Smith, Sean C
2015-11-01
Electrical charging of graphitic carbon nitride nanosheets (g-C4 N3 and g-C3 N4 ) is proposed as a strategy for high-capacity and electrocatalytically switchable hydrogen storage. Using first-principle calculations, we found that the adsorption energy of H2 molecules on graphitic carbon nitride nanosheets is dramatically enhanced by injecting extra electrons into the adsorbent. At full hydrogen coverage, the negatively charged graphitic carbon nitride achieves storage capacities up to 6-7 wt %. In contrast to other hydrogen storage approaches, the storage/release occurs spontaneously once extra electrons are introduced or removed, and these processes can be simply controlled by switching on/off the charging voltage. Therefore, this approach promises both facile reversibility and tunable kinetics without the need of specific catalysts. Importantly, g-C4 N3 has good electrical conductivity and high electron mobility, which can be a very good candidate for electron injection/release. These predictions may prove to be instrumental in searching for a new class of high-capacity hydrogen storage materials. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
11. Single ion induced surface nanostructures: a comparison between slow highly charged and swift heavy ions.
Science.gov (United States)
Aumayr, Friedrich; Facsko, Stefan; El-Said, Ayman S; Trautmann, Christina; Schleberger, Marika
2011-10-05
This topical review focuses on recent advances in the understanding of the formation of surface nanostructures, an intriguing phenomenon in ion-surface interaction due to the impact of individual ions. In many solid targets, swift heavy ions produce narrow cylindrical tracks accompanied by the formation of a surface nanostructure. More recently, a similar nanometric surface effect has been revealed for the impact of individual, very slow but highly charged ions. While swift ions transfer their large kinetic energy to the target via ionization and electronic excitation processes (electronic stopping), slow highly charged ions produce surface structures due to potential energy deposited at the top surface layers. Despite the differences in primary excitation, the similarity between the nanostructures is striking and strongly points to a common mechanism related to the energy transfer from the electronic to the lattice system of the target. A comparison of surface structures induced by swift heavy ions and slow highly charged ions provides a valuable insight to better understand the formation mechanisms. © 2011 IOP Publishing Ltd
12. Atomic physics and synchrotron radiation: The production and accumulation of highly charged ions
International Nuclear Information System (INIS)
Johnson, B.M.; Meron, M.; Agagu, A.; Jones, K.W.
1986-01-01
Synchrotron radiation can be used to produce highly-charged ions, and to study photoexcitation and photoionization for ions of virtually any element in the periodic table. To date, with few exceptions, atomic physics studies have been limited to rare gases and a few metal vapors, and to photoexcitation energies in the VUV region of the electromagnetic spectrum. These limitations can now be overcome using photons produced by high-brightness synchrotron storage rings, such as the x-ray ring at the National Synchrotron Light Source (NSLS) at Brookhaven. Furthermore, calculations indicate that irradiation of an ion trap with an intense energetic photon beam will result in a viable source of highly-charged ions that can be given the name PHOBIS: the PHOton Beam Ion Source. Promising results, which encourage the wider systematic use of synchrotron radiation in atomic physics research, have been obtained in recent experiments on VUV photoemission and the production and storage of multiply-charged ions. 26 refs., 4 figs., 1 tab
13. A hybrid, broadband, low noise charge preamplifier for simultaneous high resolution energy and time information with large capacitance semiconductor detector
International Nuclear Information System (INIS)
Goyot, M.
1975-05-01
A broadband and low noise charge preamplifier was developed in hybrid form, for a recoil spectrometer requiring large capacitance semiconductor detectors. This new hybrid and low cost preamplifier permits good timing information without compromising energy resolution. With a 500 pF external input capacity, it provides two simultaneous outputs: (i) the faster, current sensitive, with a rise time of 9 nsec and 2 mV/MeV on 50 ohms load, (ii) the lower, charge sensitive, with an energy resolution of 14 keV (FWHM Si) using a RC-CR ungated filter of 2 μsec and a FET input protection [fr
14. Laser-engraved carbon nanotube paper for instilling high sensitivity, high stretchability, and high linearity in strain sensors
KAUST Repository
Xin, Yangyang
2017-06-29
There is an increasing demand for strain sensors with high sensitivity and high stretchability for new applications such as robotics or wearable electronics. However, for the available technologies, the sensitivity of the sensors varies widely. These sensors are also highly nonlinear, making reliable measurement challenging. Here we introduce a new family of sensors composed of a laser-engraved carbon nanotube paper embedded in an elastomer. A roll-to-roll pressing of these sensors activates a pre-defined fragmentation process, which results in a well-controlled, fragmented microstructure. Such sensors are reproducible and durable and can attain ultrahigh sensitivity and high stretchability (with a gauge factor of over 4.2 × 10(4) at 150% strain). Moreover, they can attain high linearity from 0% to 15% and from 22% to 150% strain. They are good candidates for stretchable electronic applications that require high sensitivity and linearity at large strains.
15. High charge state metal ion production in vacuum arc ion sources
International Nuclear Information System (INIS)
Brown, I.G.; Anders, A.; Anders, S.
1994-01-01
The vacuum arc is a rich source of highly ionized metal plasma that can be used to make a high current metal ion source. Vacuum arc ion sources have been developed for a range of applications including ion implantation for materials surface modification, particle accelerator injection for fundamental nuclear physics research, and other fundamental and applied purposes. Typically the source is repetitively pulsed with pulse length of order a millisecond and duty cycle or order 1% and operation of a dc embodiment has been demonstrated also. Beams have been produced from over 50 of the solid metals of the periodic table, with mean ion energy up to several hundred keV and with peak (pulsed) beam current up to several amperes. The ion charge state distribution has been extensively studied. Ion spectra have been measured for a wide range of metallic cathode materials, including Li, C, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ge, Sr, Y, Zr, Nb, Mo, Pd, Ag, Cd, In, Sn, Sb, Ba, La, Ce, Pr, Nd, Sm, Gd, Dy, Ho, Er, Tm, Yb, Hf, Ta, W, Ir, Pt, Au, Pb, Bi, Th and U, as well as compound and alloy cathode materials such as TiC, SiC, UC, PbS, brass, and stainless steel. The ions generated are in general multiply-stripped with a mean charge state of from 1 to 3, depending on the particular metal species, and the charge state distribution can have components from Q = 1+ to 6+. Here the authors review the characteristics of vacuum arc ion sources from the perspective of their high charge state metal ion production
16. Study of the multiple ionization in the ion-atom collisions with highly charged sulfur as well as with neutral and lowly charged fluorine projectiles
International Nuclear Information System (INIS)
1986-01-01
With the collisional systems 115 MeV S +Q (Q=+13, +15, +16) on He, Ne, Ar, and Kr as well as 4 MeV F +Q (Q=-1, 0, +1) on Ne the multiple ionization in the ion-atom collision was studied. With the collisional system 4 MeV F +Q on Ne the multiple ionization of target and projectile was studied by coincidence measurement between the recoil ions and projectiles with the charge state Q' after the collision (Q'=-1 to +3). In the pure ionization (no change of the projectile charge) the measured ionization cross sections for the single positive and negative charged projectile are equally large, those of the neutral F projectiles are lower. The comparison with the point particles protons and electrons resulted that the ionization cross sections of the F projectiles are larger and more strongly higher charged recoil ions are produced. The measured ionization cross sections of the F projectile are larger than those of the Ne target atom which is to be reduced to the lower ionization energies of the F projectile. With the highly charged S projectiles the multiple ionization with capture into the projectile was studied. By the measurement of triple coincidcences between recoil ions, projectiles, and SKX-radiation the cases with and without capture into the K shell can be discriminated. The charge distribution with is shifted against that without capture into the K shell to higher charges. This shift is to be reduced to the decay of autoionization states which arise by the capture into the K shell. (orig./HSI) [de
17. Influence of polymer size, liposomal composition, surface charge, and temperature on the permeability of pH-sensitive liposomes containing lipid-anchored poly(2-ethylacrylic acid
Directory of Open Access Journals (Sweden)
Lu T
2012-09-01
Full Text Available Tingli Lu,1 Zhao Wang,2 Yufan Ma,1 Yang Zhang,2 Tao Chen1,21Key Laboratory for Space Bioscience and Biotechnology, School of Life Science, Northwestern Polytechnical University, 2Liposome Research Centre, Xi'an, ChinaBackground: Liposomes containing pH-sensitive polymers are promising candidates for the treatment of tumors and localized infection. This study aimed to identify parameters influencing the extent of contents release from poly(ethylacrylic acid (PEAA vesicles, focusing on the effects of polymer size, lipid composition, vesicle surface charge, and temperature.Methods: Anchored lipid pH-sensitive PEAA was synthesized using PEAA with a molecular weight of 8.4 kDa. PEAA vesicles were prepared by insertion of the lipid-anchored PEAA into preformed large unilamellar vesicles. The preformed liposomes were manipulated by varying the phosphocholine and cholesterol content, and by adding negative or positive charges to the liposomes. A calcein release assay was used to evaluate the effects of polymer size, liposome composition, surface charge, and temperature on liposomal permeability.Results: The release efficiency of the calcein-entrapped vesicles was found to be dependent on the PEAA polymer size. PEAA vesicles containing a phosphatidylcholine to cholesterol ratio of 60:40 (mol/mol released more than 80% of their calcein content when the molecular weight of PEAA was larger than 8.4 kDa. Therefore, the same-sized polymer of 8.4 kDa was used for the rest of study. The calcein release potential was found to decrease as the percentage of cholesterol increased and with an increase in the phosphocholine acyl chain length (DMPC . DPPC . DSPC. Negatively charged and neutral vesicles released similar amounts of calcein, whereas positively charged liposomes released a significant amount of their contents. pH-sensitive release was dependent on temperature. Dramatic content release was observed at higher temperatures.Conclusion: The observed
18. Highly efficient and stable dye-sensitized solar cells based on nanographite/polypyrrole counter electrode
International Nuclear Information System (INIS)
Yue, Gentian; Zhang, Xin’an; Wang, Lei; Tan, Furui; Wu, Jihuai; Jiang, Qiwei; Lin, Jianming; Huang, Miaoliang; Lan, Zhang
2014-01-01
Graphical abstract: Much higher photovoltaic performance of dye-sensitized solar cell with nanographite/PPy counter electrode as well as that of Pt configuration device. - Highlights: • Pt-free dye-sensitized solar cells. • The nanographite/PPy composite film showed high catalytic activity as well as Pt electrode. • The enhanced catalytic activity was attributed to increased active sites. • The DSSC based on the nanographite/PPy electrode showed a high photovoltaic performance. - Abstract: Nanographite/polypyrrole (NG/PPy) composite film was successfully prepared via in situ polymerization on rigid fluorine-doped tin oxide substrate and served as counter electrode (CE) for dye-sensitized solar cells (DSSCs). The surface morphology and composition of the composite film were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectra and Fourier transform infrared spectroscopy (FTIR). The electrochemical performance of the NG/PPy electrode was evaluated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The results of CV and EIS revealed that the NG/PPy electrode possessed excellent electrocatalytic activity for the reduction reaction of triiodide to iodide and low charge transfer resistance at the interface between electrolyte and CE, respectively. The DSSC assembled with the novel NG/PPy CE exhibited an enhanced power conversion efficiency of 7.40% under full sunlight illumination as comparing to that of the DSSC based on sputtered-Pt electrode. Thus, the NG/PPy CE could be premeditated as a promising alternative CE for low-cost and high- efficient DSSCs
19. Effect of different photoanode nanostructures on the initial charge separation and electron injection process in dye sensitized solar cells: A photophysical study with indoline dyes
Energy Technology Data Exchange (ETDEWEB)
Idígoras, Jesús [Nanostructured Solar Cells Group, Department of Physical, Chemical and Natural Systems, Universidad Pablo de Olavide, Ctra. Utrera, km 1, ES-41013 Seville (Spain); Sobuś, Jan [NanoBioMedical Centre, Adam Mickiewicz University, Umultowska 85, 61-614 Poznań (Poland); Quantum Electronics Laboratory, Faculty of Physics, Adam Mickiewicz University in Poznań, Umultowska 85, 61-614 Poznań (Poland); Jancelewicz, Mariusz [NanoBioMedical Centre, Adam Mickiewicz University, Umultowska 85, 61-614 Poznań (Poland); Azaceta, Eneko; Tena-Zaera, Ramon [Materials Division, IK4-CIDETEC, Parque Tecnológico de San Sebastián, Paseo Miramón 196, Donostia-San Sebastián, 20009 (Spain); Anta, Juan A. [Nanostructured Solar Cells Group, Department of Physical, Chemical and Natural Systems, Universidad Pablo de Olavide, Ctra. Utrera, km 1, ES-41013 Seville (Spain); Ziółek, Marcin, E-mail: marziol@amu.edu.pl [Quantum Electronics Laboratory, Faculty of Physics, Adam Mickiewicz University in Poznań, Umultowska 85, 61-614 Poznań (Poland)
2016-02-15
Ultrafast and fast charge separation processes were investigated for complete cells based on several ZnO-based photoanode nanostructures and standard TiO{sub 2} nanoparticle layers sensitized with the indoline dye coded D358. Different ZnO morphologies (nanoparticles, nanowires, mesoporous), synthesis methods (hydrothermal, gas-phase, electrodeposition in aqueous media and ionic liquid media) and coatings (ZnO–ZnO core–shell, ZnO–TiO{sub 2} core–shell) were measured by transient absorption techniques in the time scale from 100 fs to 100 μs and in the visible and near-infrared spectral range. All of ZnO cells show worse electron injection yields with respect to those with standard TiO{sub 2} material. Lower refractive index of ZnO than that of TiO{sub 2} is suggested to be an additional factor, not considered so far, that can decrease the performance of ZnO-based solar cells. Evidence of the participation of the excited charge transfer state of the dye in the charge separation process is provided here. The lifetime of this state in fully working devices extends from several ps to several tens of ps, which is much longer than the typically postulated electron injection times in all-organic dye-sensitized solar cells. The results here provided, comprising a wide variety of morphologies and preparation methods, point to the universality of the poor performance of ZnO as photoanode material with respect to standard TiO{sub 2}. - Highlights: • Wide variety of morphologies and preparation methods has been checked for ZnO cells. • All ZnO cells work worse than TiO{sub 2} ones. • Effective refractive index might be an additional factor in solar cell performance. • Excited charge transfer state of indoline dyes participates in the charge separation.
20. Accelerated Sensitivity Analysis in High-Dimensional Stochastic Reaction Networks.
Science.gov (United States)
Arampatzis, Georgios; Katsoulakis, Markos A; Pantazis, Yannis
2015-01-01
Existing sensitivity analysis approaches are not able to handle efficiently stochastic reaction networks with a large number of parameters and species, which are typical in the modeling and simulation of complex biochemical phenomena. In this paper, a two-step strategy for parametric sensitivity analysis for such systems is proposed, exploiting advantages and synergies between two recently proposed sensitivity analysis methodologies for stochastic dynamics. The first method performs sensitivity analysis of the stochastic dynamics by means of the Fisher Information Matrix on the underlying distribution of the trajectories; the second method is a reduced-variance, finite-difference, gradient-type sensitivity approach relying on stochastic coupling techniques for variance reduction. Here we demonstrate that these two methods can be combined and deployed together by means of a new sensitivity bound which incorporates the variance of the quantity of interest as well as the Fisher Information Matrix estimated from the first method. The first step of the proposed strategy labels sensitivities using the bound and screens out the insensitive parameters in a controlled manner. In the second step of the proposed strategy, a finite-difference method is applied only for the sensitivity estimation of the (potentially) sensitive parameters that have not been screened out in the first step. Results on an epidermal growth factor network with fifty parameters and on a protein homeostasis with eighty parameters demonstrate that the proposed strategy is able to quickly discover and discard the insensitive parameters and in the remaining potentially sensitive parameters it accurately estimates the sensitivities. The new sensitivity strategy can be several times faster than current state-of-the-art approaches that test all parameters, especially in "sloppy" systems. In particular, the computational acceleration is quantified by the ratio between the total number of parameters over the | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8325463533401489, "perplexity": 5401.705376555189}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-30/segments/1531676593208.44/warc/CC-MAIN-20180722100513-20180722120513-00007.warc.gz"} |
http://math.stackexchange.com/users/41721/covertbob?tab=questions&sort=votes | covertbob
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0 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5112390518188477, "perplexity": 24964.504992456466}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2016-22/segments/1464049281876.4/warc/CC-MAIN-20160524002121-00081-ip-10-185-217-139.ec2.internal.warc.gz"} |
https://brilliant.org/discussions/thread/prototyping-windows-8/ | ×
# Prototyping Windows 8
Hey! Yesterday I thought of experimenting with a new web design, so I decided to prototype Windows 8 using pure CSS3 (used a bit of jQuery too). I have managed to successfully prototype it to a great extent (although much work is still left). All I wanted is to ask, why do all my transitions lag so much. I mean, I've seen other websites which use heavy transitions but they all are so smooth. Here, all my transitions are kinda slow and require much of processing speed. Can someone help me with that?
I am not very sure if this is the appropriate place to ask this question or not but I am confident that there are many super-talented memebers on Brilliant.org and someone can definitely help me with that and sorry if this note of mine, anyhow doesn't meets the Rules And Guidelines.
Remember, it is just an experiment! Also, note that currently, it works only on latest browsers and please go full screen. And the password is : password
Here's the link to my work. $$\ddot \smile$$
Note by Kishlaya Jaiswal
2 years, 4 months ago
Sort by:
From where did you learnt all this? · 2 years, 4 months ago
Actually it depends on, to what extent can you use your internet connection.
Ok,coming to the point. For the first time, I saw my elder cousin writing a code in HTML and making a webpage. That's what lit up a fire in me and it proved a great inspiration. I was awestruck to know that all these graphic elements are actually coded contrary to my belief that those were drawn using some sought graphic software(s) (actually I was in grade 5th that time so I hardly knew much about such things). That was the time, when I started coding. Little by little I coded. from writing simple headings, colouring them, etc to making some simple webpages and finally developing the above project.
And the resources which I've used so far includes w3schools.com (for learning basics), www.smashingmagazine.com, codepen.io (learned to develop some nice snippets and some other cool things), and then source codes of major websites like Google, Brilliant, etc. And some other great resources are also out there, just search the google.
And yes, what I think the key factor to learn web development is : "Keep Experimenting" · 2 years, 4 months ago
Well that's amazing and what you said is really true.Hats off!!!! · 2 years, 4 months ago
Oh! Thanks. The above words mean a lot to me. · 2 years, 4 months ago
the webpage is amazing!!!!!!! · 2 years, 4 months ago
Thanks. $$\ddot \smile$$ · 2 years, 4 months ago
You're one of those Super Talented ones @Kishlaya Jaiswal , congratulations for this much knowledge and skill at the age of $$\color{Red}{\text{just 18}}$$... · 2 years, 4 months ago
Thanks.
And yes, I'm not one of those super-talented guys. Indeed you are one of them. $$\ddot \smile$$ · 2 years, 4 months ago
I am not a computer expert but do you know about gpu acceleration? · 2 years, 4 months ago
Yes, but I know only a little bit about it. Oh! that may help. Thanks. · 2 years, 4 months ago
Yay!! CSS3! I love it! Lemme have a look. · 2 years, 4 months ago
It doesn't lag here. Might be hardware problems. · 2 years, 4 months ago
Nope, I've confirmed the lag (tested it on a friend's desktop as well as my laptop)
Actually there's a lag when you pull up the welcome screen and when the start screen appears. It's kinda slow rather it should have been smooth. I've seen some websites where developers have used heavy animations and transitions but they are still very smooth. · 2 years, 4 months ago
You mean like the animations you put on the JOMO website ? · 2 years, 4 months ago
It didn't lagged with @Anton Kriksunov . Neither me. I am sure its hardware or network problem. Its just awesome. How much time did it take? · 2 years, 4 months ago
Haha, seems like I've got some old rusty hardware.
And it took me 2 days to build that (although much work is still left). On first day I did the wireframing and setting up Boot Screen, Welcome Screen and Start Screen. Next day, I worked on desktop, icons, start screen manipulations and the charms bar. Well, I am still not satisfied by icons and even I couldn't find any pre-built metro icons package (something of FontAwesome type) on google.
EDIT : And I don't see any comment from @Anton Kriksunov ? · 2 years, 4 months ago | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8739736676216125, "perplexity": 2765.657299597674}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-30/segments/1500549423716.66/warc/CC-MAIN-20170721042214-20170721062214-00686.warc.gz"} |
http://mathematica.stackexchange.com/questions/19679/automatic-inverse-for-lambert-s-azimuthal-equal-area-projection | # Automatic inverse for Lambert’s Azimuthal Equal-Area Projection
I’m interested in finding closed-form inverses for map projection equations in general (of course, this is not always possible). I’m hoping Mathematica can help me with some of the trickier ones.
As a practice run, I thought I would try and use Mathematica to invert Lambert’s Azimuthal Equal-Area Projection. There are of course closed-form inverse equations on MathWorld, but I’m wondering how I would go about finding these using Mathematica.
I’ve tried using Solve and Reduce, for example:
k = Sqrt[2/(1 + s1 Sin[y] + c1 Cos[y] Cos[x])]
Solve[{u, v} == {
k Cos[y] Sin[x],
k (c1 Sin[y] - s1 Cos[y] Cos[x])
}, {x, y}]
But no luck so far. Perhaps I need to specify more constraints?
For example, I know that the longitude and latitude (x and y above) have:
-π ≤ x ≤ π
-π/2 ≤ y ≤ π/2
I wonder if eliminating variables might also help the solving routines.
-
Have you seen the help pages for Latitude and Longitude? A (minor modification of an) example from that page exhibits an unprojection: Through[{Latitude, Longitude}[GeoGridPosition[{-0.12605573,-0.0464294, 0}, "LambertConformalConic"]]]. – whuber Feb 16 '13 at 11:56
I'm interested in automatically finding closed-form inverse formulæ, given arbitrary forward projection equations, so I'm not sure that really helps me. But thanks anyway! – Jason Davies Feb 16 '13 at 12:33
I've clarified the wording of the question a bit, so it's clear what I'm trying to achieve. – Jason Davies Feb 16 '13 at 12:35
In most cases there's no such thing as closed-form inverse formulae for non-spherical datums, so I presume you mean to apply these equations only to spheres. See pubs.usgs.gov/pp/1395/report.pdf for details. Moreover, only the simpler projections have closed forms, so the problem does not generally have a solution. – whuber Feb 16 '13 at 12:40
Yes, I’m only dealing with spheres, so that should simplify things. I know there is no general solution, but I'd like to know how to solve the simplest ones using Mathematica. Lambert’s azimuthal equal-area seems relatively simple, yet as you can see I’ve failed so far to find the (already known) result using Solve or Reduce. – Jason Davies Feb 16 '13 at 12:45 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.6489691734313965, "perplexity": 1715.678998595125}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-23/segments/1405997865523.12/warc/CC-MAIN-20140722025745-00038-ip-10-33-131-23.ec2.internal.warc.gz"} |
http://mathhelpforum.com/differential-geometry/160119-both-open-closed-set-proof.html | Math Help - Both open and closed set proof
1. Both open and closed set proof
Prove that the only sets that are both open and closed are $\mathbb{R}$ and the empty set $\phi$.
How do you go about proving that every other set is either open, closed, or neither? There are infinitely many other sets.
2. What do you know about connected sets? The space $\mathbb{R}$ is connected.
If $F\subseteq \mathbb{R}$, is non-trivial, and is both open and closed then $F\cup F^c=\mathbb{R}$.
3. If $F$ is open then $F^c$ is closed. So if a set is both open and closed, what does that make the complement of that set? Neither open nor closed?
4. No. These are known as clopen sets (both open and closed).
So if $F$ is clopen then $F^c$ is clopen.
There is a well known result about connected sets and clopen sets.
Otherwise, I have not seen this topic discussed.
5. So if I can prove that the empty set, $\phi$, is both open and closed (or clopen) then I can say that the set of all reals, $\mathbb{R}$, is clopen because $\mathbb{R}$ is the complement to $\phi$?
6. It is completely obvious that those two sets are both open and closed.
They are the only two sets in $\mathbb{R}$ that are. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 14, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9450826048851013, "perplexity": 143.99880416141124}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-23/segments/1406510273676.54/warc/CC-MAIN-20140728011753-00423-ip-10-146-231-18.ec2.internal.warc.gz"} |
http://mathhelpforum.com/statistics/198744-distribution-data-using-standard-deviation.html | # Thread: the distribution of data using standard deviation
1. ## the distribution of data using standard deviation
Hello,
How much data should lie outside +/- 1 standard deviation from the mean in the following example?
If assessing the number of calories consumed by women in a day and the mean was 1800 and the standard deviation was 200, how many women consumed more than 1600 calories (population size 1000)?
What is the cutoff for the 99% points?
If I can get a detailed answer of how this is done, it would be greatly appreciated.
Thank you very much!
2. ## Re: the distribution of data using standard deviation
Is the data approximately normally distributed?
3. ## Re: the distribution of data using standard deviation
I think so. That's all the information I was given.
4. ## Re: the distribution of data using standard deviation
You should know that about 68% of the data lies within 1 standard deviation from the mean of any normal distribution...
5. ## Re: the distribution of data using standard deviation
Would it be possible for someone to answer this question in detail please?
6. ## Re: the distribution of data using standard deviation
Originally Posted by cupsk8
Would it be possible for someone to answer this question in detail please?
What a lazy and ungrateful poster. You're welcome...
7. ## Re: the distribution of data using standard deviation
That's really rude. I'm not being ungrateful or lazy. I don't understand this question at all and I have a huge exam tomorrow and this is the only example like this - it's not even a statistics exam and I've been looking at how to do it for about an hour now. I asked for help kindly AND said please.
8. ## Re: the distribution of data using standard deviation
I don't even want the ANSWER. I just want to know HOW I would go about doing it.
9. ## Re: the distribution of data using standard deviation
And I gave you the first step, and you did not even attempt to work through the problem, just begging for someone to do your work for you. I find that really rude, as do most of the helpers on this site.
10. ## Re: the distribution of data using standard deviation
Okay, can we just back up for a second. I don't even know where to BEGIN. Let me try using 68%. So, everything above 1600 calories would be 68% of the population. So then 680 women consumed over 1600 calories?
And I did say it would be greatly appreciated... I haven't done stats in 8 years.
11. ## Re: the distribution of data using standard deviation
Thank you for showing some effort. You are on the right track, but your question asked how many lie outside of +/- 1 standard deviation from the mean.
Now I'm just wondering if you made a typo. Are you sure the standard deviation is not 2000 calories instead of 200? In the context of the question, that would lie 1 standard deviation from the mean.
12. ## Re: the distribution of data using standard deviation
No, I checked and it's not a typo. That's what it asks. So is the answer not 680 women then?
13. ## Re: the distribution of data using standard deviation
Sorry I misread the question. My original hunch was correct.
No, the answer is not 680 women. Like I said, you are asked how many women consumed more than 1600 calories. All you have done so far is say how many ate between 1600 and 2000 calories (i.e. within one standard deviation from the mean).
Think about the bell curve. All you have shown so far is that 68% lie in between one standard deviation, but you haven't counted what is in the uppermost tail. See this diagram...
If 68% of the data lies within one standard deviation, then 34% lies within the tails. Half of that is in the uppermost tail.
So what percentage of the data are we actually counting?
14. ## Re: the distribution of data using standard deviation
32% of data should lie outside +/-1 standard deviation,
840 women consumed more than 1600 calories,
and cut-off points are 1300 and 2300 calories.
15. ## Re: the distribution of data using standard deviation
Originally Posted by cupsk8
32% of data should lie outside +/-1 standard deviation,
840 women consumed more than 1600 calories,
and cut-off points are 1300 and 2300 calories.
Yes, I agree you are dealing with (68 + 16)% = 84% of the data, which is 840 women.
You are also very close with your cutoff points, but it's actually 99.7% of the data that lies within 3 standard deviations from the mean, not 99%. To be more accurate you will need to convert to the standard normal distribution. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8015565872192383, "perplexity": 544.8722275961371}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-30/segments/1500549425254.88/warc/CC-MAIN-20170725142515-20170725162515-00006.warc.gz"} |
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Their jacket on top of their Smocks when they feel cold. a) Tm value b) C- value c) D -Value d) Cot value 14. c) Commercial Off-The-System state b) A post-architecture model d) Automatic Link Creation and Change, 2 points d) Since software is essentially ‘intangible’ it is relatively easy to manage software projects There are two parts – Essays and Multiple choice questions. 1 point Long Questions and Answers. the reason for such a situation? - Software Engineering Mcqs - Advanced Software Engineering Mcqs ERP stands for a) Evolutionary development usually comes in two flavors; exploratory development, and Access FREE Trigonometric Ratios Of Complementary Angles Interactive Worksheets! 1. Participate in the Sanfoundry Certification contest to get free Certificate of Merit. Answer: a ... To practice all areas of Software Engineering, here is complete set of 1000+ Multiple Choice Questions and Answers on Software Engineering. 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(iii) False, cos A is the abbreviation of cosine A. c) reusability a) COTS-solution systems (d) Module For, example information retrieval techniques, monitoring of change history, naming schemas or, 2 points e) The complexity of systems and their interaction continues faster than we can understand it. What must be. Subscribe and get the complete access of Scholastic Aptitude Test - Mathematics - NTSE - X Standard MCQ Online Test - MCQ's Online Test Series Pack and score high marks. The process of transfer of biological information from RNA to DNA in certain viruses was discovered by a) Francis Crick, 1958 b) Baltimore ,1970 c) Hargobind Singh Khorana, 1970 d) Watson , 1970 15. Practice these MCQ questions and answers for preparation of various competitive and entrance exams. Over 70 % of the following is a generic structure that is extended to create a more specific or! Topic in Engineering Mathematics comfy new bed from Very Multiple Choice questions on Motion for competitions exams! Feel cold cot and a coupled independent components into … Question 5 value c ) high effectiveness d ) of! Top HACCP quizzes measuring the complexity ( size ) of DNA or genome - -! And Obaby DNA or genome list out 2 Multiple Choice questions & answers Mcqs. Model is used to compute the effort Required to integrate reusable components or angle θ they feel cold the way. Engineering strategy where the development process is geared to reusing existing Software costs )... One will enjoy safe and cosy nights in a comfy new bed from Very practice these MCQ and... E ) Client to be used during the process and Distance - Scholastic Aptitude Test Mathematics... Coupled independent components into … Question 5 list out 2 Multiple Choice questions from each skill category some angle.! To Software development, Identify, from among the following is not an of. ) COTS-solution systems b ) Integration ( c ) high effectiveness d ) Staff,! A Math Thinker, the correct option to Test your skills Motion following might be the only means of the. Approaches to Software development, Identify, from among the following, the correct to! Arrange the following is not considered as a risk in project management ) control. Consists of Physics Multiple Choice questions: -Click Here —- > postgresql Interview questions ready be. ) True b ) C- value c ) Alpha ( d ) Module e! Component communication and information exchange Version control c ) testing b ) Object-oriented language... Basic/General Engineering process model i ) False View Answer, 9 of Smocks... Simple designs from little Acorns, all ready to be used during the process remainder fail to deliver features. Language c ) Alpha ( d ) Staff turnover, Required 3, videos, internships and!... Smocks when they feel cold designs from little Acorns, all ready to be during... A slow learner 2 Multiple Choice questions Part 1 of the Series in Trigonometry in. Free Trigonometric Ratios of Complementary Angles Interactive Worksheets access to some kind of graphics 2D.! Answers ( Mcqs ) focuses on “ Software reuse ” cots stands for mcq designs from little Acorns, ready. S dignity her daughter Bholi because she was a slow learner call cot value GATE. Of Software Engineering Mcqs stand 70 % of the Series in Plane Trigonometry topic in Engineering Mathematics of libraries provide.... of initial ssDNA and time take to renature 50 % of It call cot and... By Roy Britten and Eric Davidson in 1960 Unit ( b ) Object-oriented Programming language c ) cots stands for mcq. To list out 2 Multiple Choice questions with answers among the following is a Software Engineering Multiple Choice questions for! Of cosine a MCQ systems Programming MCQ UNIX System MCQ Neural Networks MCQ Fuzzy systems MCQ a particular Type... Programming language c ) Alpha ( d ) cot a is the abbreviation of cosine a Integration... It suggests good practices to be used during the process Software Engineering considered as a risk in management... Some of the mentioned in the sanfoundry Certification contest to get FREE of! - Advanced Software Engineering Mcqs stand mentioned View Answer, 2 one will enjoy safe and cosy nights a! ( Mcqs ) focuses on “ Software reuse specialization View Answer, 2 get Certificate... And Multiple Choice questions on Motion for competitions and exams a directory of Objective questions! Examples of large-scale COTS reuse your little one will enjoy safe and cosy nights in a comfy new from. ) of DNA or genome cot value 14 from each skill category of! In Software Engineering exam questions a generic structure that is extended to create a specific... One will enjoy safe and cosy nights in a comfy new bed from Very each category. It call cot value class include standards and classes that support component communication and information exchange Multiple Choice from. Finger COTS and ESD shoes generic application systems that may be designed support. To compute the effort Required to integrate reusable components or approaches to Software development,,... The final form of testing COTS Software is _____ testing of their Smocks when feel! A truly rigorous discipline e ) Beta the program & answers ( Mcqs focuses. Advantages of Software Engineering Mcqs - Advanced Software Engineering effectiveness d ) Both COTS-solution COTS-integrated. Information exchange be adapted to suit your requirements for taking some of the following is not considered as a in... Cots-Solution systems b ) Version control c ) Contractor ( d ) Staff,! Make your child a Math Thinker, the correct Answer and ITS DETAIL EXPLANATION FREE Trigonometric Ratios of Angles... A Math Thinker, the correct option to Test your skills Motion questions with answers effectiveness... Continues faster than we can understand It complete Enterprise Interactive Worksheets of graphics 2D functions neglected! Distance - Scholastic Aptitude Test - Mathematics - NTSE - X Standard - Online Test... Good practices to be teamed with pretty bedding Specification delays d ) Svedbergs ”. Trivia quizzes can be adapted to suit your requirements for taking some of the model time... Point ( a ) size b ) miRNAs are involved in the regulation of CSCs properties include standards classes! Networks BELOW and stay updated with latest contests, videos, internships and jobs renature 50 % of It cot! ) Middleware Integration frameworks c ) Environment specialization d ) LINUX View Answer, 8 Global Education Learning... Enterprise Resource Planning systems are examples of large-scale COTS reuse ) Functional specialization Answer. 60S ribosome parts stands for _____ is a Software Engineering iv ) cot value and cot Curve It... 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And a None of the Series in Trigonometry topic in Engineering Mathematics Engineering is a reuse-based approach to defining implementing!, all ready to be used during the process activities that are enacted Curve It! Systems d ) Module ( e ) Beta Advanced Software Engineering MCQ systems Programming MCQ UNIX System Neural... ) Integration ( c ) Framework d ) Svedbergs baby COTS from trusted like. Which of the remainder fail to deliver expected features ” trusted brands Mamas... Reuse-Based approach to defining, implementing, and composing loosely coupled independent components into … Question 5 the cotengent angle... Daughter Bholi because she was a slow learner features ” ) high effectiveness d ) lower risks View Answer MCQ! Of cosine a wrist strap, finger COTS and ESD shoes Planning systems are examples of large-scale COTS.! Where the development process is geared to reusing existing Software from each skill.! On WIRELESS SENSOR Networks 1 Interview questions ’ associated with 40S and ribosome..., GATE, IES, PSUs, NET/SET/JRF, UPSC and other entrance exams communication and exchange... Global Education & Learning Series – Software Engineering is a technique for measuring the complexity systems. And over 70 % of the girl ’ s dignity Integration frameworks c ) Environment specialization )! Account different approaches to Software development, Identify, from among the steps. Practice Test MCQ - 2020 compute the effort Required to integrate reusable components or as a risk in management... ) SCIs d ) cot value and cot Curve analysis It is a technique for measuring the of! Tm value b ) Subunit c ) Enterprise application frameworks d ) LINUX View Answer,.... You THINK that ABOVE POSTED MCQ is WRONG of cosine a over 70 % of call. C- value c ) SCIs d ) None of the mentioned Mcqs - Advanced Engineering.
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http://mathhelpforum.com/math-topics/2065-i-need-help-quick-print.html | # I need help quick!!!!
• March 1st 2006, 09:43 PM
sharingan237
I need help quick!!!!
I have a assiment that i have no ideas how to do. Can someone please help, it due tomorrow morning.
Thank in advance to anyone that can help.
Ted's tee charge \$3.75 per shirt, \$0.80 to print each shirt with a design, and \$125 per order for the silk-screen design.
1.Suppose that the track team wishes to make a profit of \$1000 from the sale of T-shirts. Explore several pricing schemes that result in this level of profit by adjusting the amount that the track team charges for the shirts and the number of shirts that need to be sold.
2. For each pricing scheme that you explored in Question 1 , write an equation that represents how many T-shirts need to be sold to reach the break-even point, the point at which the cost and income are the same.
3.For each pricing scheme that you explored in question 1 , write an equation that represents how many T-shirts need to be sold to make a profit of \$1000
• March 4th 2006, 01:41 AM
CaptainBlack
Quote:
Originally Posted by sharingan237
I have a assiment that i have no ideas how to do. Can someone please help, it due tomorrow morning.
Thank in advance to anyone that can help.
Ted's tee charge \$3.75 per shirt, \$0.80 to print each shirt with a design, and \$125 per order for the silk-screen design.
1.Suppose that the track team wishes to make a profit of \$1000 from the sale of T-shirts. Explore several pricing schemes that result in this level of profit by adjusting the amount that the track team charges for the shirts and the number of shirts that need to be sold.
Let the order size be $N$, then the cost in dollars is:
$
C=125+N(3.75+0.80)=125+4.55N
$
Now suppose they sell $M \le N$ shirts at the same price for
each shirt of $p$ dollars, then the revenue is:
$
R=Mp
$
So the profit is:
$
P=R-C=Mp-125-4.55N
$
Now you need to investigate the number that need to be ordered, sold and
the price charged to result in \$1000 profit. At this stage you could also
possibly assume that all the shirts are sold so $M=N$.
An alternative method of pricing could be to charge $p_1$ for the first
$M_1$ shirts and $p_2$ for any further shirts sold.
RonL
• March 4th 2006, 01:44 AM
CaptainBlack
Quote:
Originally Posted by sharingan237
2. For each pricing scheme that you explored in Question 1 , write an equation that represents how many T-shirts need to be sold to reach the break-even point, the point at which the cost and income are the same.
The break-even point is the point at which $P=0$
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