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11,735,522 | https://en.wikipedia.org/wiki/Oracle%20unified%20method | The Oracle unified method (OUM), first released by Oracle Corporation in 2006, is a standards-based method with roots in the unified process (UP). OUM is business-process and use-case driven and includes support for the Unified Modeling Language (UML), though the use of UML is not required. OUM combines these standards with aspects of Oracle's legacy methods and Oracle implementation best-practices.
OUM is applicable to any size or type of information technology project. While OUM is a plan-based method – that includes extensive overview material, task and artifact descriptions, and associated templates – the method is intended to be tailored to support the appropriate level of ceremony required for each project. Guidance is provided for identifying the minimum subset of tasks, tailoring the project approach, executing iterative and incremental project planning, and applying agile techniques. Supplemental guidance provides specific support for Oracle products, tools, and technologies.
Supported topics
OUM v6.4.0 provides support for:
Application implementation
Cloud application services implementation
Software upgrade projects
as well as the complete range of technology projects including:
Business intelligence (BI)
Enterprise security
WebCenter
Service-oriented architecture (SOA)
Application Integration Architecture (AIA)
Business process management (BPM)
Enterprise integration
Custom software
Detailed techniques and tool guidance are provided, including a supplemental guide related to Oracle Tutor and UPK.
Availability
OUM is available for use by Oracle employees; for Oracle PartnerNetwork Diamond, Platinum, and Gold Partners; and for customers who participate in the OUM Customer Program.
Legacy method retirement dates:
Oracle Custom Development Method (CDM), February 2010
Oracle CDM Fast Track, February 2010
Oracle Application Implementation Methodology (AIM), January 2011
Oracle AIM for Business Flows, January 2011
Oracle's Siebel Results Roadmap, January 2011
Oracle Data Warehouse Method (DWM) Fast Track, May 2011
Oracle EasiPath Migration Method (EMM), December 2011
Oracle's PeopleSoft Compass Methodology, June 2013
Formal methods
Oracle software | Oracle unified method | [
"Engineering"
] | 415 | [
"Software engineering",
"Formal methods"
] |
11,735,693 | https://en.wikipedia.org/wiki/Complex%20quadratic%20polynomial | A complex quadratic polynomial is a quadratic polynomial whose coefficients and variable are complex numbers.
Properties
Quadratic polynomials have the following properties, regardless of the form:
It is a unicritical polynomial, i.e. it has one finite critical point in the complex plane, Dynamical plane consist of maximally 2 basins: basin of infinity and basin of finite critical point ( if finite critical point do not escapes)
It can be postcritically finite, i.e. the orbit of the critical point can be finite, because the critical point is periodic or preperiodic.
It is a unimodal function,
It is a rational function,
It is an entire function.
Forms
When the quadratic polynomial has only one variable (univariate), one can distinguish its four main forms:
The general form: where
The factored form used for the logistic map:
which has an indifferent fixed point with multiplier at the origin
The monic and centered form,
The monic and centered form has been studied extensively, and has the following properties:
It is the simplest form of a nonlinear function with one coefficient (parameter),
It is a centered polynomial (the sum of its critical points is zero).
it is a binomial
The lambda form is:
the simplest non-trivial perturbation of unperturbated system
"the first family of dynamical systems in which explicit necessary and sufficient conditions are known for when a small divisor problem is stable"
Conjugation
Between forms
Since is affine conjugate to the general form of the quadratic polynomial it is often used to study complex dynamics and to create images of Mandelbrot, Julia and Fatou sets.
When one wants change from to :
When one wants change from to , the parameter transformation is
and the transformation between the variables in and is
With doubling map
There is semi-conjugacy between the dyadic transformation (the doubling map) and the quadratic polynomial case of c = –2.
Notation
Iteration
Here denotes the n-th iterate of the function :
so
Because of the possible confusion with exponentiation, some authors write for the nth iterate of .
Parameter
The monic and centered form can be marked by:
the parameter
the external angle of the ray that lands:
at c in Mandelbrot set on the parameter plane
on the critical value:z = c in Julia set on the dynamic plane
so :
Examples:
c is the landing point of the 1/6 external ray of the Mandelbrot set, and is (where i^2=-1)
c is the landing point the 5/14 external ray and is with
Map
The monic and centered form, sometimes called the Douady-Hubbard family of quadratic polynomials, is typically used with variable and parameter :
When it is used as an evolution function of the discrete nonlinear dynamical system
it is named the quadratic map:
The Mandelbrot set is the set of values of the parameter c for which the initial condition z0 = 0 does not cause the iterates to diverge to infinity.
Critical items
Critical points
complex plane
A critical point of is a point on the dynamical plane such that the derivative vanishes:
Since
implies
we see that the only (finite) critical point of is the point .
is an initial point for Mandelbrot set iteration.
For the quadratic family the critical point z = 0 is the center of symmetry of the Julia set Jc, so it is a convex combination of two points in Jc.
Extended complex plane
In the Riemann sphere polynomial has 2d-2 critical points. Here zero and infinity are critical points.
Critical value
A critical value of is the image of a critical point:
Since
we have
So the parameter is the critical value of .
Critical level curves
A critical level curve the level curve which contain critical point. It acts as a sort of skeleton of dynamical plane
Example : level curves cross at saddle point, which is a special type of critical point.
Critical limit set
Critical limit set is the set of forward orbit of all critical points
Critical orbit
The forward orbit of a critical point is called a critical orbit. Critical orbits are very important because every attracting periodic orbit attracts a critical point, so studying the critical orbits helps us understand the dynamics in the Fatou set.
This orbit falls into an attracting periodic cycle if one exists.
Critical sector
The critical sector is a sector of the dynamical plane containing the critical point.
Critical set
Critical set is a set of critical points
Critical polynomial
so
These polynomials are used for:
finding centers of these Mandelbrot set components of period n. Centers are roots of n-th critical polynomials
finding roots of Mandelbrot set components of period n (local minimum of )
Misiurewicz points
Critical curves
Diagrams of critical polynomials are called critical curves.
These curves create the skeleton (the dark lines) of a bifurcation diagram.
Spaces, planes
4D space
One can use the Julia-Mandelbrot 4-dimensional (4D) space for a global analysis of this dynamical system.
In this space there are two basic types of 2D planes:
the dynamical (dynamic) plane, -plane or c-plane
the parameter plane or z-plane
There is also another plane used to analyze such dynamical systems w-plane:
the conjugation plane
model plane
2D Parameter plane
The phase space of a quadratic map is called its parameter plane. Here:
is constant and is variable.
There is no dynamics here. It is only a set of parameter values. There are no orbits on the parameter plane.
The parameter plane consists of:
The Mandelbrot set
The bifurcation locus = boundary of Mandelbrot set with
root points
Bounded hyperbolic components of the Mandelbrot set = interior of Mandelbrot set with internal rays
exterior of Mandelbrot set with
external rays
equipotential lines
There are many different subtypes of the parameter plane.
See also :
Boettcher map which maps exterior of Mandelbrot set to the exterior of unit disc
multiplier map which maps interior of hyperbolic component of Mandelbrot set to the interior of unit disc
2D Dynamical plane
"The polynomial Pc maps each dynamical ray to another ray doubling the angle (which we measure in full turns, i.e. 0 = 1 = 2π rad = 360°), and the dynamical rays of any polynomial "look like straight rays" near infinity. This allows us to study the Mandelbrot and Julia sets combinatorially, replacing the dynamical plane by the unit circle, rays by angles, and the quadratic polynomial by the doubling modulo one map." Virpi KaukoOn the dynamical plane one can find:
The Julia set
The Filled Julia set
The Fatou set
Orbits
The dynamical plane consists of:
Fatou set
Julia set
Here, is a constant and is a variable.
The two-dimensional dynamical plane can be treated as a Poincaré cross-section of three-dimensional space of continuous dynamical system.
Dynamical z-planes can be divided into two groups:
plane for (see complex squaring map)
planes (all other planes for )
Riemann sphere
The extended complex plane plus a point at infinity
the Riemann sphere
Derivatives
First derivative with respect to c
On the parameter plane:
is a variable
is constant
The first derivative of with respect to c is
This derivative can be found by iteration starting with
and then replacing at every consecutive step
This can easily be verified by using the chain rule for the derivative.
This derivative is used in the distance estimation method for drawing a Mandelbrot set.
First derivative with respect to z
On the dynamical plane:
is a variable;
is a constant.
At a fixed point ,
At a periodic point z0 of period p the first derivative of a function
is often represented by and referred to as the multiplier or the Lyapunov characteristic number. Its logarithm is known as the Lyapunov exponent. Absolute value of multiplier is used to check the stability of periodic (also fixed) points.
At a nonperiodic point, the derivative, denoted by , can be found by iteration starting with
and then using
This derivative is used for computing the external distance to the Julia set.
Schwarzian derivative
The Schwarzian derivative (SD for short) of f is:
See also
Misiurewicz point
Periodic points of complex quadratic mappings
Mandelbrot set
Julia set
Milnor–Thurston kneading theory
Tent map
Logistic map
References
External links
Monica Nevins and Thomas D. Rogers, "Quadratic maps as dynamical systems on the p-adic numbers"
Wolf Jung : Homeomorphisms on Edges of the Mandelbrot Set. Ph.D. thesis of 2002
More about Quadratic Maps : Quadratic Map
Complex dynamics
Fractals
Polynomials | Complex quadratic polynomial | [
"Mathematics"
] | 1,822 | [
"Functions and mappings",
"Complex dynamics",
"Mathematical analysis",
"Polynomials",
"Mathematical objects",
"Fractals",
"Mathematical relations",
"Algebra",
"Dynamical systems"
] |
11,736,149 | https://en.wikipedia.org/wiki/Distributed%20multipole%20analysis | In computational chemistry, distributed multipole analysis (DMA) is a compact and accurate way of describing the spatial distribution of electric charge within a molecule.
Multipole expansion
The DMA method was devised by Prof. Anthony Stone of Cambridge University to describe the charge distribution of a molecule in terms of a multipole expansion around a number of centers. The idea of using a multi-center multipole expansion was earlier proposed by Robert Rein. Typically, the centers correspond to the atoms constituting the molecule, though this is not a requirement. A multipole series, consisting of a charge, dipole, quadrupole and higher terms is located at each center. Importantly, the radius of convergence of this multipole series is sufficiently small that the relevant series will be convergent when describing two molecules in van der Waals contact.
The DMA series are derived from ab initio or density functional theory calculations using Gaussian basis sets. If the molecular orbitals are written as linear combinations of atomic basis functions the electron density takes the form of a sum of products of the basis functions, called density matrix elements. Boys (1950) showed that the product of two spherical Gaussian functions, centered at different points, can be expressed as a single Gaussian at an intermediate point known as the overlap center.
If a basis of Gaussian functions is used, the product of two s functions is spherically symmetric and can be represented completely just by a point charge at the ‘overlap center’ of the two Gaussian functions. The product of an s orbital and a p orbital has only charge and dipole components, and the product of two p functions has charge, dipole and quadrupole components.
If the overlap center is not at an atom, one can move the origin of the multipole expansion to the nearest distributed multipole site, re-expressing the series to account for the change of origin. The multipole expansion will no longer terminate, but the higher terms will be small. One may take the sites wherever one chooses, but they will usually be at the atoms. For small molecules one may wish to use additional sites at the centers of bonds; for larger molecules one may use a single site to describe a group of atoms such as a methyl group. The DMA procedure is exact and very fast, but for modern large basis sets with diffuse basis functions it has to be modified somewhat. When the basis functions have exponents that are small, the product function extends over several atoms, and it is better to calculate the distributed multipoles by numerical quadrature over a grid of points. The grid can be defined so that each point is associated with a particular site, and the multipoles for each site are obtained by quadrature over the points belonging to that site.
This description then includes at each site:
Charges, describing electronegativity effects in a chemically intuitive way;
Dipoles, arising from overlap of s and p orbitals and describing lone pairs and other atomic distortions;
Quadrupoles, arising from the overlap of p orbitals, and associated with pi bonds, for example;
Octopoles and hexadecapoles can be included if very high accuracy is required.
The DMA describes the potential at points outside the molecule with an accuracy which is essentially that of the wavefunction, so that its use entails no loss of precision. The DMA description gives the electrostatic energy of interaction between two molecules. It does not account for charge overlap effects and hence excludes the penetration energy.
Comparison to other methods
DMA is inherently much more accurate than the commonly used partial charge methodologies for calculating intermolecular interaction energies, since it captures anisotropy of the atom-atom contributions to electrostatic interaction. It may therefore seem surprising that it has not been more widely used in molecular simulation. Possible reasons for this are:
Its non-inclusion in popular simulation codes;
The need to keep track of the orientation of a local axis system for each molecule;
The conformation-dependence of the DMA. As a consequence of its accuracy, the DMA captures features of the molecular charge distribution that depend strongly on molecular conformation. Thus, in a DMA-based simulation, the multipoles would have to be recalculated whenever a molecule underwent a conformational change.
Applications
DMA has found extensive use in crystal structure prediction for small organic molecules, where significant progress can often be made while using rigid molecular structures. It has also been used to develop force fields for molecular simulations, such as the AMOEBA force field.
References
Quantum chemistry
Computational chemistry
Theoretical chemistry | Distributed multipole analysis | [
"Physics",
"Chemistry"
] | 937 | [
"Quantum chemistry",
"Quantum mechanics",
"Theoretical chemistry",
"Computational chemistry",
" molecular",
"nan",
"Atomic",
" and optical physics"
] |
11,736,738 | https://en.wikipedia.org/wiki/Fizeau%20interferometer | A Fizeau interferometer is an interferometric arrangement whereby two reflecting surfaces are placed facing each other. As seen in Fig 1, the rear-surface reflected light from the transparent first reflector is combined with front-surface reflected light from the second reflector to form interference fringes.
The term Fizeau interferometer also refers to an interferometric arrangement used by Hippolyte Fizeau in a famous 1851 experiment that seemingly supported the partial ether-drag hypothesis of Augustin Jean Fresnel, but which ultimately played an instrumental role in bringing about a crisis in physics that led to Einstein's development of the theory of special relativity. See Fizeau experiment.
Applications
Fizeau interferometers are commonly used for measuring the shape of an optical surface: Typically, a fabricated lens or mirror is compared to a reference piece having the desired shape. In Fig. 1, the Fizeau interferometer is shown as it might be set up to test an optical flat. A precisely figured reference flat is placed on top of the flat being tested, separated by narrow spacers. The reference flat is slightly beveled (only a fraction of a degree of beveling is necessary) to prevent the rear surface of the flat from producing interference fringes. A collimated beam of monochromatic light illuminates the two flats, and a beam splitter allows the fringes to be viewed on-axis.
The reference piece is sometimes realized by a diffractive optical element (computer-generated hologram or CGH), as this can be manufactured by high accuracy lithographic methods. Fig. 2 illustrates the use of CGHs in testing. Unlike the figure, actual CGHs have line spacing on the order of 1 to 10 μm. When laser light is passed through the CGH, the zero-order diffracted beam experiences no wavefront modification. The wavefront of the first-order diffracted beam, however, is modified to match the desired shape of the test surface. In the illustrated Fizeau interferometer test setup, the zero-order diffracted beam is directed towards the spherical reference surface, and the first-order diffracted beam is directed towards the test surface in such a way that the two reflected beams combine to form interference fringes.
Fizeau interferometers are also used in fiber optic sensors for measuring pressure, temperature, strain, etc.
Fizeau's ether-drag experiment
Significance
In 1851, Fizeau used an entirely different form of interferometer to measure the effect of movement of a medium upon the speed of light, as seen in Fig. 3.
According to the theories prevailing at the time, light traveling through a moving medium would be dragged along by the medium, so the measured speed of the light would be a simple sum of its speed through the medium plus the speed of the medium.
Fizeau indeed detected a dragging effect, but the magnitude of the effect that he observed was far lower than expected. His results seemingly supported the partial ether-drag hypothesis of Fresnel, a situation that was disconcerting to most physicists.
Over half a century passed before a satisfactory explanation of Fizeau's unexpected measurement was developed with the advent of Einstein's theory of special relativity.
Experimental setup
Light reflected from the tilted beam splitter is made parallel using a lens and split by slits into two beams, which traverse a tube carrying water moving with velocity v. Each beam travels a different leg of the tube, is reflected at the mirror at left, and returns through the opposite leg of the tube. Thus, both beams travel the same path, but one in the direction of flow of the water, and the other opposing the flow. The two beams are recombined at the detector, forming an interference pattern that depends upon any difference in time traveling the two paths.
The interference pattern can be analyzed to determine the speed of light traveling along each leg of the tube.
See also
Hippolyte Fizeau
List of types of interferometers
References
External links
Some typical measurement setups from the booklet of interferometer manufacturer Zygo Corp.
Interferometers
Observational astronomy | Fizeau interferometer | [
"Astronomy",
"Technology",
"Engineering"
] | 866 | [
"Interferometers",
"Observational astronomy",
"Astronomical sub-disciplines",
"Measuring instruments"
] |
11,736,831 | https://en.wikipedia.org/wiki/HD%2081040 | HD 81040 is a star in the equatorial constellation of Leo. With an apparent visual magnitude of +7.73 it is too dim to be visible to the naked eye but can be viewed with a small telescope. The star is located at a distance of 112 light years from the Sun based on parallax. It is drifting further away with a radial velocity of +49 km/s, having come to within some 527,000 years ago.
Properties
This is an ordinary G-type main-sequence star with a stellar classification of G0V. The Sun somewhat dwarfs HD 81040 in terms of physical characteristics: it has 87% of the Sun's mass and 91% of the radius of the Sun. It is spinning with a projected rotational velocity of 5.3 km/s, and has near solar metallicity. The age of the star is not precisely known; the ELODIE spectrograph suggested 0.8 Gyr and found it to have a young dust disk. Later measurements by modelling chromosperic activity suggested an age of 4.18 Gyr.
Planetary system
On November 24, 2005, a superjovian planet was announced by Sozzetti et al. It was discovered using the radial velocity method. Astrometric measurements using Gaia, published in several papers, show that the inclination of its orbit is about 111 degrees, so its true mass is somewhat higher than that predicted from its minimum mass.
See also
List of extrasolar planets
List of stars in Leo
References
External links
The Extrasolar Planets Encyclopaedia: HD 81040
G-type main-sequence stars
Planetary systems with one confirmed planet
Circumstellar disks
Leo (constellation)
Durchmusterung objects
081040
046070 | HD 81040 | [
"Astronomy"
] | 360 | [
"Leo (constellation)",
"Constellations"
] |
11,737,468 | https://en.wikipedia.org/wiki/Probabilistic%20bisimulation | In theoretical computer science, probabilistic bisimulation is an extension of the concept of bisimulation for fully probabilistic transition systems first described by K.G. Larsen and A. Skou.
A discrete probabilistic transition system is a triple
where gives the probability of starting in the state s, performing the action a and ending up in the state t. The set of states is assumed to be countable. There is no attempt to assign probabilities to actions. It is assumed that the actions are chosen nondeterministically by an adversary or by the environment. This type of system is fully probabilistic, there is no other indeterminacy.
The definition of a probabilistic bisimulation on a system S is an equivalence relation R on the state space St, such that for every pair s,t in St with sRt and for every action a in Act and for every equivalence class C of R
Two states are said to be probabilistically bisimilar if there is some such R relating them.
When applied to Markov chains, probabilistic bisimulation is the same concept as lumpability.
Probabilistic bisimulation extends naturally to weighted bisimulation.
References
Theoretical computer science | Probabilistic bisimulation | [
"Mathematics"
] | 262 | [
"Theoretical computer science",
"Applied mathematics"
] |
11,737,650 | https://en.wikipedia.org/wiki/Molecular%20drive | Molecular drive is a term coined by Gabriel Dover in 1982 to describe evolutionary processes that change the genetic composition of a population through DNA turnover mechanisms. Molecular drive operates independently of natural selection and genetic drift.
The best-known such process is the concerted evolution of genes present in many tandem copies, such as those for ribosomal RNAs or silk moth egg shell chorion proteins, in sexually reproducing species. The concept has been proposed to extend to the diversification of multigene families. The mechanisms involved include gene conversion, unequal crossing-over, transposition, slippage replication and RNA-mediated exchanges. Because mutations changing the sequence of one copy are less common than deletions, duplications and replacement of one copy by another, the copies gradually come to resemble each other much more than they would if they had been evolving independently.
Concerted evolution can be unbiased, in which case every version has an equal probability of being the one that replaces the others. However, if the molecular events have any bias favouring one version of the sequence over others, that version will dominate the process and eventually replace the others. The name 'molecular drive' reflects the similarity of the process with what was originally the better-known process of meiotic drive.
Molecular drive can also act in bacteria, where parasexual processes such as natural transformation cause DNA turnover.
TRAM
According to Dover, TRAM is a genetic system that has features of non-mendelian inheritance Turnover, copy number and functional Redundancy And Modulatory. To date all regulatory regions (promoters) and genes that have been examined in detail at the molecular level, have TRAM characteristics. As such, part of their evolutionary history will have been influenced by the molecular drive process.
Adoptation
According to Dover, Adoptation is an evolved feature of an organism that contributes to its viability and reproduction (established by molecular drive) and that adopts some previously inaccessible component of the environment.
References
Evolutionary biology
Molecular evolution
Non-Darwinian evolution | Molecular drive | [
"Chemistry",
"Biology"
] | 408 | [
"Evolutionary biology",
"Evolutionary processes",
"Molecular evolution",
"Molecular biology",
"Non-Darwinian evolution",
"Biology theories"
] |
11,737,949 | https://en.wikipedia.org/wiki/HD%2081040%20b | HD 81040 b is a massive gas giant exoplanet that orbits the star HD 81040, discovered in 2005 by radial velocity. Its orbital period is just over 1000 days. It has a semimajor axis of about 1.95 AU, and its orbit is quite eccentric, at a little over 0.5.
Astrometry of HD 81040 using Gaia, published in several papers, has determined an orbital inclination of about 111°. This, combined with the minimum mass, gives a true mass of . Since the inclination is high, there is a small chance that the planet transits.
See also
HD 33564 b
References
Leo (constellation)
Giant planets
Exoplanets discovered in 2005
Exoplanets detected by radial velocity
Exoplanets detected by astrometry | HD 81040 b | [
"Astronomy"
] | 164 | [
"Leo (constellation)",
"Constellations"
] |
11,738,155 | https://en.wikipedia.org/wiki/Spatiotemporal%20Epidemiological%20Modeler | The Spatiotemporal Epidemiological Modeler (STEM) is free software available through the Eclipse Foundation. Originally developed by IBM Research, STEM is a framework and development tool designed to help scientists create and use spatial and temporal models of infectious disease. STEM uses a component software architecture based on the OSGi standard. The Eclipse Equinox platform is a reference implementation of that standard. By using a component software architecture, all of the components or elements required for a disease model, including the code and the data are available as software building blocks that can be independently exchanged, extended, reused, or replaced. These building blocks or plug-ins are called eclipse "plug-ins" or "extensions". STEM plug-ins contain denominator data for administrative regions of interest. The regions are indexed by standard (ISO3166) codes.
STEM currently includes a large number of plug-ins for the 244 countries and dependent areas defined by the Geographic Coding Standard maintained by the International Organization for Standardization. These plug-ins contain global data including geographic data, population data, demographics, and basic models of disease. The disease models distributed with STEM include epidemiological compartment models. Other plug-ins describe relationships between regions including nearest-neighbor or adjacency relationships as well as information about transportation, such as connections by roads and a model of air transportation.
Relationships between regions can then be included in models of how a disease spreads from place to place. To accomplish this, STEM represents the world as a "graph". The nodes in the graph correspond to places or regions, and the edges in the graph describe relationships or connections between regions. Both the nodes and the edges can be labeled or "decorated" with a variety of denominator data and models. This graphical representation is implemented using the Eclipse Modeling Framework (EMF). Since a model can be built up using separate subgraphs, STEM enables model composition. Predefined subgraphs defining different countries can be assembled with a drag and drop interface. New disease vectors can simply be added to existing models by augmenting the model with a new set of edges. The architecture also supports collaboration as users can not only create new models and compose new scenarios but also exchange these models and scenarios as reusable components and thereby build on each other's work. As an open source project, users are encouraged to create their own plug-ins (both data and models) and, if appropriate, to contribute their work back to the project.
References
External links
STEM
Free science software
Free health care software
Epidemiology
Public health and biosurveillance software
IBM software
Space and time | Spatiotemporal Epidemiological Modeler | [
"Physics",
"Environmental_science"
] | 536 | [
"Physical quantities",
"Time",
"Space",
"Epidemiology",
"Spacetime",
"Environmental social science",
"Space and time"
] |
11,738,158 | https://en.wikipedia.org/wiki/Monilinia%20fructigena | Monilinia fructigena is a plant pathogen in the fungus kingdom causing a fruit rot of apples, pears, plums, peaches and cherries.
Classification
Three Monilinia species cause brown rot of fruit (Monilinia laxa, Monilinia fructicola, Monilinia fructigena); Monilinia fructigena is found most commonly to cause brown rot in fruits of the Pome family and Rosaceae family. The genus Monilinia could be viewed as divided into two sections, Disjunctoriae and Junctoriae; M. fructigena belongs to Junctoriae. These ‘sections’ are the resulting attempt to further differentiate Monilinia into two separate classifications based on morphology, the specialization of the pathogens’ hosts, and the biological process of infection. Belonging to the section Junctoriae entails possessing no disjunctor cells in between the mature spores contained in the conidial chains. Differentiation in the laboratory of the three main Monilinia species can be quite difficult. In a report by De Cal and Melgarejo, it was demonstrated that the species can be differentiated through altering the light exposure to a long-wave UV light and dark cycle. Monilinia fructigena and Monilinia fructicola can be recognized from Monilinia laxa in this experiment, as M. laxa possesses a noticeably short distance from the conidia to the first germ tube branch. Furthermore, M. fructigena and M. fructicola can be individually distinguishable through measuring the maximum diametric growth rate of the culture. The maximum growth rate of M. fructigena was just 8 mm/2 days, whilst M. fructicola expanded its diameter by 20 mm after two days. Conidia produced by Monilinia fructigena are noted to be dry spores, and are not discharged, but pulled away on currents of wind. The conidiophores are short and unspecialized, and perform as a means to elevate the spore chains above infected tissues to provide better exposure to air currents. Except for the occasion of a desiccated infected fruit falling to the ground, peduncles and fruits carrying the pathogen are in the perfect place for further dispersal of airborne spores—in a tree, of course. Infection of fruits by M. fructigena can take place during all periods of development, from the fruitlet to the mature fruit.
Hosts and symptoms
When infection occurs during or shortly after pollination, asymptomatic growth of the pathogen allows the fruit to mature normally. However, as the fruit ripens, small circular brown spots begin developing and quickly rotting on the flesh's surface; given plenty of moisture, conidial pustules develop on the infected areas. On mature infected fruits, brown rot spreads quickly throughout the fruit as a brown decay of the flesh. In areas/climates with high relative humidity, conidial tufts appear at the surface of the fruit; when RH is low, the fruit simply desiccates. Fruit rot caused by the brown rot pathogen Monilinia fructigena is a notorious ailment found in Malus domestica—the apple tree—with the fungus occasionally spreading from the infected fruit to the branches, causing cankering. With apple infections, a varying symptom can occur within the fruits, causing what is commonly known as “black apple”. This symptom entails the color of the rot changing from brown to a deep shade of black. The apple skin remains shiny and unbroken, and shrinkage of the actual tissue does not occur until later in development, where it often rots quickly in storage. Fruit rot is commonly found on apples, pears, and plums, but is less often found within peaches, nectarines, or apricots.
Disease cycle
Within the short span of several days, the entire ripe fruit is rotten and rife with conidial tufts and/or vegetative growth of mycelium. When relative humidity surrounding the fruit is low, conidial tufts and mycelium do not develop. After dropping in a mummified form to the ground, the pathogen overwinters, eventually sending up apothecia to produce the wind-carried ascospores that arrive on new plant tissues. Fallen infected tissues that possess sufficient moisture to undergo the sporulation process often provide a source of secondary inoculation. Under the right conditions, mycelial growth takes place, forming a hardened sclerotia sphere-shape around the core or seed of the fruit. As this mycelial/stroma growth is taking place, the outside of the fruit rots away. The resulting germination utilizes a third type of spore called a “microconidia” that acts as a spermatia in sexual reproduction. Roberts and Dunegan postulated that the means of aerial distribution of conidia resulted in widespread transportation to new hosts, while rain performs well as a means of washing the conidia into more favorable conditions. Conidia are not the only primary way Monilinia fructigena has been observed to be propagated in nature. There are numerous insects, such as wasps, beetles, flies, and butterflies that have been recognized as vectors of Monilinia spp. Birds wounding the tree or its fruits have been identified as possible wound-causing agents that allow the fungus to enter the host.
Environment and management
In a study conducted over a period of four years by Holb and Scherm (2007), it was reasonably concluded that the use of integrated management along with inorganic insecticides attributed a lower infection rate (6.4%) than plots using just organic insecticides (20.1%). With Monilinia fructigena, it is important to note that primary infection of the pathogen occurs through wounds; vector control may be a more logical route of attempting to control the fungus. It was also found that certain fungicides, namely pyraclostrobin and boscalid, applied after spring bloom were effective against Monilinia fructigena as a means of combating primary infection. Conidia produced by Monilinia fructigena are also spread by the wind in times of high temperatures and low relative humidity; conidia can also be spread by rain drops. When spores are spread by rain dislodging the conidia, the added water also provides a supply of moisture for germination and mycelial development.
Photographs
References
Fungal plant pathogens and diseases
Apple tree diseases
Pear tree diseases
Stone fruit tree diseases
Sclerotiniaceae
Fungi described in 1801
Fungus species | Monilinia fructigena | [
"Biology"
] | 1,386 | [
"Fungi",
"Fungus species"
] |
11,738,269 | https://en.wikipedia.org/wiki/Valsaria%20insitiva | Valsaria insitiva is a plant pathogen, that causes perennial canker in apples and almonds.
See also
List of apple diseases
List of almond diseases
References
External links
Index Fungorum
USDA ARS Fungal Database
Enigmatic Dothideomycetes taxa
Fungi described in 1863
Fungal tree pathogens and diseases
Apple tree diseases
Fruit tree diseases
Fungus species | Valsaria insitiva | [
"Biology"
] | 72 | [
"Fungi",
"Fungus species"
] |
11,738,333 | https://en.wikipedia.org/wiki/Monilinia%20mali | Monilinia mali is a fungal plant pathogen which causes leaf blight on apple.
References
Fungal tree pathogens and diseases
Apple tree diseases
Sclerotiniaceae
Fungi described in 1945
Fungus species | Monilinia mali | [
"Biology"
] | 40 | [
"Fungi",
"Fungus species"
] |
11,738,413 | https://en.wikipedia.org/wiki/Hyphodontia%20aspera | Hyphodontia aspera is a species of fungus in the family Schizoporaceae.
References
Fungi described in 1874
Hymenochaetales
Fungal plant pathogens and diseases
Taxa named by Elias Magnus Fries
Fungus species | Hyphodontia aspera | [
"Biology"
] | 49 | [
"Fungi",
"Fungus species"
] |
11,738,475 | https://en.wikipedia.org/wiki/Perenniporia%20medulla-panis | Perenniporia medulla-panis is a species of poroid fungus in the family Polyporaceae. It is a plant pathogen that infects stone fruit trees. The species was first described by Nikolaus Joseph von Jacquin in 1778. Marinus Anton Donk transferred it to the genus Perenniporia in 1967.
References
Fungi described in 1778
Fungi of Europe
Fungal tree pathogens and diseases
Stone fruit tree diseases
Perenniporia
Fungus species | Perenniporia medulla-panis | [
"Biology"
] | 95 | [
"Fungi",
"Fungus species"
] |
11,738,539 | https://en.wikipedia.org/wiki/Phellinus%20pomaceus | Phellinus pomaceus is a plant pathogen particularly common on Prunus species. It is not aggressively pathogenic but can cause considerable decay in trees suffering from other stress factors. P. pomaceus is found in Europe as well as areas of Asia, South America and Africa. This species has historically been used for medicinal purposes and is currently being researched for its chemical and biological properties. This is a very long-lived conk, bearing as many as eighty annual growth rings.
References
Fungal tree pathogens and diseases
Stone fruit tree diseases
pomaceus
Fungi described in 1933
Taxa named by Christiaan Hendrik Persoon
Fungus species | Phellinus pomaceus | [
"Biology"
] | 130 | [
"Fungi",
"Fungus species"
] |
11,738,598 | https://en.wikipedia.org/wiki/Gibberella%20fujikuroi | Gibberella fujikuroi is a fungal plant pathogen. It causes bakanae disease in rice seedlings.
Another name is foolish seedling disease. It gets that name because the seeds can be infected, leading to disparate outcomes for the plant. There are not many diseases that initiate similar symptoms as bakanae.
Hosts and symptoms
Gibberella fujikuroi is most widely known for its disease producing capabilities in rice, but barley, millet, sugarcane and maize are also susceptible. In all infected plants, similar symptoms have been found, though rice has been most predominantly studied. The most telltale symptom of Bakanae is the tall, spindly look of the plant. This is a result of the gibberellins, or growth hormones, the fungus secretes. Infected plants are easy to pick out, then, as they often rise above the rest of the healthy plants with regularly secreted growth hormones. However, it is also possible that stunting may occur, along with Chlorosis of the leaves of the plant, root lesions, or empty grains of plants grown to maturity.
Disease cycle
Gibberella fujikuroi is a polycyclic ascomycete. Thus, it is possible to, at the right stage of the lifecycle of the pathogen, see perithecia or conidia under the microscope. The pathogen overwinters in perithecia and will infect through soil in seeds that are not pre-infected. Infected seed is also a source of inoculum; conidia will germinate when planted. Infected seeds are the main way the disease is propagated. Symptoms can be observed during growing season.
Environment
Bakanae is observed in all rice growing areas of the world. Thus, the pathogen thrives in the same growing conditions as rice. Rice requires a warm, wet growing season. Fields may even be flooded. The disease is known to be able to spread through water. Additionally, infected spores can be spread during harvesting. Thus, it is important to quarantine the infected seeds.
Management
There have been many management solutions put forth, with the most important and widely used being the use of treated seeds. Growers should confer with the source of their seeds and as a second measure, check the weight of the seeds they receive. Lightweight seeds are typically infected. Seeds can also be treated to prevent pathogen activation. There are two options that have been found to be successful: hot water baths and chlorine treatments. However, one cannot be sure that the pathogen will be fully neutralized when subjected to these conditions.
Resistance in rice has also been studied. Specifically, the Binam cultivar has been found to be the most resistant to the disease, thus producing the largest yield in experiments when the disease was purposefully induced. Other varieties have shown partial resistance, but none as strong as Binam.
One new option that is under investigation for management potential is treating the seeds with silver nanoparticles. The particles are a known antifungal that are not toxic to humans. In one study, treatment with the particles reduced the incidence of the disease significantly.
Importance
In rice crops, this disease has made a staggering economic impact. Losses have been specifically high in Asian countries, namely India, Thailand, and Japan. Specifically, Basmati rice has been a main target for Gibberella fujikuroi. At times, growers have lost up to 50% of their crop. However, rates of disease are not often so high and only occur during epidemic years.
Luckily, attempts at management have found success in the past and new treatments are continually researched. Growers can be confident that they will find an option to deal with this disease if it is present in their crop, if not initially, then hopefully by the next growing season.
Pathogenesis
The pathogen induces excessive gibberellin production in the plant, resulting in the rapid growth of the hosts. The amount of Gibberellin is important in determining the extent of the disease. Another interaction between the plant and pathogen is the sporulation of mycelium at the lower levels of the plant - white fungal masses can be observed. Conidia, the secondary inoculum, are the result of these spore masses.
References
External links
Index Fungorum
USDA ARS Fungal Database
Gibberella moniliformis, fusarium at MetaPathogen: stages, tissues, references
Fungal plant pathogens and diseases
Rice diseases
fujikuroi
IARC Group 2B carcinogens
Fusarium
Fungi described in 1931
Fungus species | Gibberella fujikuroi | [
"Biology"
] | 927 | [
"Fungi",
"Fungus species"
] |
11,738,605 | https://en.wikipedia.org/wiki/Fusarium%20verticillioides | Fusarium verticillioides is the most commonly reported fungal species infecting maize (Zea mays). Fusarium verticillioides is the accepted name of the species, which was also known as Fusarium moniliforme. The species has also been described as mating population A of the Fusarium fujikuroi species complex (formally known as Gibberella fujikuroi species complex). F. verticllioides produces the mutagenic chemical compound fusarin C. F. verticillioides produces a group of disease-causing mycotoxins—fumonisins—on infected kernels.
References
Fungal plant pathogens and diseases
verticillioides
Fungi described in 1881
Fungus species | Fusarium verticillioides | [
"Biology"
] | 157 | [
"Fungi",
"Fungus species"
] |
11,738,774 | https://en.wikipedia.org/wiki/Phyllosticta%20perseae | Phyllosticta perseae is a fungal plant pathogen infecting avocados.
References
External links
USDA ARS Fungal Database
Fungal plant pathogens and diseases
Avocado tree diseases
perseae
Fungi described in 1885
Fungus species | Phyllosticta perseae | [
"Biology"
] | 50 | [
"Fungi",
"Fungus species"
] |
11,738,798 | https://en.wikipedia.org/wiki/Colletotrichum%20nigrum | Colletotrichum nigrum is a fungal plant pathogen.
References
nigrum
Fungal plant pathogens and diseases
Fungi described in 1890
Fungus species | Colletotrichum nigrum | [
"Biology"
] | 32 | [
"Fungi",
"Fungus species"
] |
11,739,145 | https://en.wikipedia.org/wiki/Crown%20Fountain | Crown Fountain (sometimes known as the "Squirting Faces") is an interactive work of public art and video sculpture featured in Chicago's Millennium Park, which is located in the Loop community area. Designed by Spanish artist Jaume Plensa and executed by Krueck and Sexton Architects, it opened in July 2004. The fountain is composed of a black granite reflecting pool placed between a pair of glass brick towers. The towers are tall, and they use light-emitting diodes (LEDs) to display digital videos on their inward faces. Construction and design of the Crown Fountain cost $17 million. The water operates from May to October, intermittently cascading down the two towers and spouting through a nozzle on each tower's front face.
Residents and critics have praised the fountain for its artistic and entertainment features. It highlights Plensa's themes of dualism, light, and water, extending the use of video technology from his prior works. Its use of water is unique among Chicago's many fountains, in that it promotes physical interaction between the public and the water. Both the fountain and Millennium Park are highly accessible because of their universal design.
Crown Fountain has been one of the most controversial of all the Millennium Park features. Before it was even built, some were concerned that the sculpture's height violated the aesthetic tradition of the park. After construction, surveillance cameras were installed atop the fountain, which led to a public outcry (and their quick removal).
However, the fountain has survived its contentious beginnings to find its way into Chicago pop culture. It is a popular subject for photographers and a common gathering place. While some of the videos displayed are of scenery, most attention has focused on its video clips of local residents. The fountain is a public play area and offers people an escape from summer heat, allowing children to frolic in the fountain's water.
Concept and design
Grant Park, which is between Lake Michigan and the central business district, is commonly called "Chicago's Front Yard". Its northwest corner had been Illinois Central rail yards and parking lots until 1997, when it was made available for development by the city as Millennium Park. Millennium Park was conceived in 1998 as the capstone of Grant Park, to celebrate the new millennium and to feature world-renowned architects, artists, designers, landscape architects, and urban planners. As of 2007, Millennium Park trails only Navy Pier as a Chicago tourist attraction.
Selection of artist
In December 1999, Lester Crown and his family agreed to sponsor a water feature in Millennium Park. Unlike other park feature sponsors, the Crowns acted independently of Millennium Park officials; they conducted independent surveys of water technologies, held their own informal design contest, and stayed active in the design and engineering of the project.
The Crowns were open-minded about the choice of artist; wanting a modern work, they solicited proposals from a list of prospective artists and architects. Jaume Plensa researched the traditions and history of fountains and studied anthropomorphism in fountain imagery. Some of his early ideas for the project referenced Buckingham Fountain, but these were soon abandoned. His presentation to the Crown family started with a slide show of fountains from the Middle Ages through the 20th century. Plensa focused on the philosophical meanings associated with fountains, their history, use and art. His presentation included computer animation of facial expressions. The other finalists were Maya Lin, who presented a low-height horizontal form, and Robert Venturi, who presented a fountain that would have been tall. In January 2000, Plensa won the commission to design the fountain over Lin and Venturi. The installation is a video sculpture, commissioned to operate thirty years.
Artistic design
Prior to Crown Fountain, Plensa's dominant theme had been dualism, which he had expanded to artworks in which the viewers are outside, and the visible subjects of the art are inside containers and hollow spaces. In the 1990s, he completed several outdoor sculptures in which he explored the use of light (The Star of David (1998) at Stockholm's Raoul Wallenberg Square, Bridge of Light (1998) in Jerusalem), and LED technology, video, and computer design (Gläserne Seele & Mr. Net in Brandenburg (1999–2000)). In his public art, Plensa challenged himself to involve the viewer with his art, which led to his conception of the Crown Fountain. His objective was to create a socially relevant, interactive fountain for the 21st century. Since water is the focus of a fountain, and since Chicago, and especially Millennium Park, is so greatly affected by the nearby waterfront, Plensa sought to create an eternal water work to complement the local natural inspirations. Because of the colder winters common to the climate of Chicago, Plensa created a fountain that would remain vibrant when the water was inactive in the wintertime, so the fountain is an experience of light themes and the use of video technology.
Plensa explores dualism with Crown Fountain, where he has two randomly selected faces "conversing" with each other. Plensa feels that by using faces, he can represent the diversity of the city both in ethnicity and in age. The artist intends to portray the sociocultural evolution of the city by updating the collection of images. His representation has become a part of the city's pop culture; the first few episodes of the first season of Prison Break featured shots of the fountain.
Plensa feels that the challenge in the creation of successful work of public art is to integrate the viewer into an interactive relationship with the art. The fountain is known for encouraging its visitors to splash and slide in the reflecting pool, jostle for position under the water spout and place themselves under the cascade. This interactivity was to some degree accidental. Although the city planned for some interactivity, the transformation of the fountain into a water park for kids within hours of opening surprised Plensa. Now, when the National Weather Service issues summer heat advisories and the Governor of Illinois declares state office buildings as official daytime cooling centers, the national press points to Crown Fountain as a respite for inhabitants of the Chicago metropolitan area.
Video production
Approximately 75 ethnic, social, and religious Chicago organizations were asked to provide candidates whose faces would be photographed for integration into the fountain. The subjects were chosen from local schools, churches and community groups, and filming began in 2001 at the downtown campus of the School of the Art Institute of Chicago (SAIC). The SAIC students filmed their subjects with a $100,000 high-definition HDW-F900 video camera, the same model used in the production of the three Star Wars prequels. About 20 SAIC students took part in what became an informal master's course in public art for the project. Faculty from Columbia College Chicago was also involved in the production of the video. The high-definition equipment was used because of the scale of the project. Because the image proportions were like a movie screen with a width far exceeding its height, the camera was turned on its side during filming.
Each face appears on the sculpture for a total of 5 minutes using various parts of individual 80-second videos. A 40-second section is played at one-third speed forward and backward, running for a total of 4 minutes. Then, there is a subsequent segment, where the mouth is puckering, that is stretched to 15 seconds. This is followed by a section, in which the water appears to spout from the open mouth, that is stretched to last for 30 seconds. Finally, there is a smile after the completion of the water spouting from the mouth, that is slowed to extend for 15 seconds. Of the original 1,051 subjects filmed, 960 videos were determined to be usable for the project. Originally, the set of images was presumed to be the beginning of a work in progress, but as of 2009 no additional videos are planned.
To achieve the effect in which water appears to be flowing from subjects' mouths, each video has a segment where the subject's lips are puckered, which is then timed to correspond to the spouting water, reminiscent of gargoyle fountains. Each face is cropped so that no hair and usually no ears are visible. Since there is no tripod designed for cameras turned on their sides, an adjustable barber/dentist's chair was used to minimize the need for the movement of the state-of-the-art camera during filming. Nonetheless, in some case, digital manipulation was necessary to properly simulate puckering in the exact proper location on the video. Many of the faces had to be stretched in order to get the mouths properly positioned. Additionally, each video was color-corrected for brightness, contrast and color saturation. Both the playback equipment and the final videos had to be further adjusted to account for sunlight during viewing.
Construction and engineering
The Crown family, for whom the fountain is named, donated $10 million of the $17 million construction and design cost. The Goodman family, known for funding the Goodman Theatre, was also a large contributor; the entire $17 million cost was provided by private donations. The initial proposed cost for the fountain had been $15 million.
After two architectural firms refused the contract to make Plensa's design a reality, the firm Krueck + Sexton Architects accepted. Public art was a departure from Krueck & Sexton's residential and corporate office-dominated portfolio, which includes buildings like the Spertus Institute. Collaboration between the artist, architectural team, and consultants proved to be crucial to the success of the project. The fountain's black granite reflecting pool measures and has an approximate water depth of . It displays videos on two LED screens, each encapsulated in a glass brick tower measuring . The firm designed a special stainless steel T-frame both to bear the load of the walls, which are high, and to withstand lateral wind forces. The frame holds all the glass blocks and transfers the load to the base in a zigzag pattern. Rods measuring in diameter anchor to the structure and project into the frame for lateral stability, while triangular corner brackets add support.
After several dozen glass manufacturing firms were interviewed, L. E. Smith Glass Company emerged as the company to produce 22,500 glass blocks near the upper limit of the size of press glass formed from hand-poured molten glass and cast iron molds. The process used sand and soda ash heated to a temperature of and "gathered" with a large clay ball resembling a honey dipper. Rather than use a standard plunger to ensure the glass that sagged off the rod spread to the corners of the mold, they relied on gravity. The full mold was annealed (reheated in an oven to ) and cooled. Over the course of four months of production, about 350 blocks were produced per day.
The glass was custom-made at a factory in Mount Pleasant, Pennsylvania, and shipped to the structural glass panel manufacturer in Melbourne, Florida. The panels were then shipped by truck to Chicago. The glass is white glass, rather than the usual green glass that results from iron impurities. This has the tradeoff of increased image clarity, but greater dirt visibility. Each block is with glass thin enough to avoid image distortion. On each block, one of the six faces is polished, and the other five surfaces are textured.
The structure for the blocks was a challenge. At first, the design team had considered switching to plastic blocks, until the team found Circle Redmont Inc., a prefabricated glass panel company in Melbourne, Florida which specializes in structural glass panel systems. Circle Redmont came up with the plan of turning grates on their sides to be used as building elements. The individual grids are tall and either or wide with cell capacity of an average of 250 blocks. Each tower is composed of 44 grids stacked and welded. The combination of the refraction of the glass and the thinness of the metal make the grid virtually invisible.
The fountain uses per hour, 97% of which is recycled back into the system. Getting the water to the spout took ingenuity. Although consideration was given to omitting a LED tile, it was determined that the images would then look as though they were each missing a tooth. Instead, one tile in each tower is recessed about to allow the installation of clear tubing for the water nozzle. The water regularly spills over the fountain and down the sides of the towers and intermittently spouts from the nozzle. Two essential custom fittings contribute to the artistic vision of the fountain: a custom glass block at the upper edge for guiding the water's descent while remaining unobtrusive, and a plastic nozzle fitted to the stainless steel frame to control the rate of water flow and reduce liability to the city for any injuries sustained by the fountain's interactive participants. The interactive participants are usually children playing in the stream from the water spout or under the cascade. The risk that the spouting water would knock people down made the design both a legal and a physical challenge.
The fountains use over one million LEDs. The inner surface of each tower uses 147 smaller screens with a total of 264,480 LED points (each with two red, one blue and two green LEDs). The physical demands of LED screens, in particular the red, green, and blue long-life light bulbs and the requisite circuitry, created three major challenges: supporting the physical structure, combating heat buildup, and optimizing perceptibility of the display. Plensa had used LED fixtures on previous projects, and thus had some experience with these issues. The LED structure is not supported as a single wall (which would be high), but rather as several segments that are noticeable as visible horizontal bands every few feet: these show where the LED equipment is supported. The heat generated is handled by fans that cool the air at the bottom, that then works its way through the chimney-like tower. Perceptibility was determined to be optimal with LED lights behind the glass.
LEDs were chosen because they were viewed as the lowest maintenance option of the possible color changing fixtures. LEDs fit into an electrical circuit, causing illumination by the movement of electrons in the semiconductor material and making a filament unnecessary, so the bulbs never burn out and do not get too hot. Fins were added to the screens to keep direct sunlight from hitting the LEDs. Color Kinetics (now part of Philips Solid-State Lighting Solutions, which is now called Philips Color Kinetics) ColorBlast 12 LEDs fixtures are used to illuminate the tower structures and glass in an attempt to meet Plensa's objective that the towers have a light and translucent appearance, with their internal structures reflecting light from behind the glass surface. The electronics were designed to be adaptable to the time of day, weather and season and to meet the desired century-long longevity and dependability objectives set by the design team in response to the thirty-year directive.
The pool used pavers that weigh . The pavers were rested on screw jack pedestals in order to be leveled and shimmed. The pavers had to be perfectly leveled for the water to work correctly because the fountain incorporates numerous sensors to regulate the flow and level of the water.
During construction the underground parking garage remained open. An additional challenge was designing the structure to facilitate interior access for ongoing maintenance and repairs, while accommodating two levels of underground parking underneath. The challenge was solved by combining a T-bar grid to absorb weight with about 150 "outriggers", or "tiebacks", inserted through the video wall to support the glass blocks and absorb wind loads. This design allows for the removal of individual glass blocks for cleaning or repair without disruption to the display. The filtered air inside the towers helps minimize the need for cleaning. Crown Fountain'''s design not only included interior access for technical repairs, but also incorporated exemplary, non-discriminatory, barrier-free accessibility, because its interactivity is not limited to the able-bodied. The force of the water accounts for the entire range of possible interactive visitors.
Dedication and operation
Unveiling
Construction of the video sculpture was completed for testing without the fountain's water features on May 18, 2004. Originally, Plensa had planned to have each face appear for 13 minutes, and this continued to be the targeted duration when the testing of the sculpture occurred. Eventually, professors at the School of the Art Institute of Chicago convinced him to use only five-minute videos.
Plensa's design of Crown Fountain was unveiled to the public on July 16–18, during the 2004 grand opening celebrations for Millennium Park. At the time of the unveiling, Crown Fountain, like the nearby Cloud Gate, was incomplete because only 300 of the videos had been refined for public display. It was officially dedicated on July 24, 2004 as part of a special private fundraising party that raised $3 million for the Millennium Park Conservancy fund.
Operation
The control center for the synchronization of images, water flow, and lighting color and intensity is beneath one of the towers, in a room that covers . The room houses high-definition video servers and equipment temperature sensors. Hard drives contain all the individual electronic computer files of the face videos. Generally, the computer programs automatically perform tasks such as determining when the face will pucker and, if weather conditions permit, when to turn the water on and off. Using low- rather than high-resolution images was both less expensive and created a better display for the average viewer. A Barco show controller selects the sequence of faces one at a time and determines a random tower lighting selection of one of eight LED colors programmed into an Electronic Theatre Controls (ETC) Emphasis control system. At night, the ETC system controls spotlights that illuminate the cascading water and that are dimmed by special wet-use location ground fault circuit interrupters. The control room covers an area equal to 26 parking spaces in the underground parking garage, which costs the city $100,000 annually in terms of the opportunity cost of lost revenue (in 2004 dollars). Maintenance issues for the fountain range from kids removing the adhesive between the bricks to pipes in need of maintenance. , annual upkeep costs were approximately $400,000. Typically, the fountain's water features function between mid-spring and mid-fall, but the images remain on the screen year-round.
Video sculpture
The front face of each tower is animated with a continuous, dynamic exhibit of lights and electronic images. Although the screens on the towers periodically display clips of landscapes such as waterfalls, most intriguing are the display of faces of Chicago residents. About 1,000 faces of Chicagoans are shown in a random rotation, the order determined using a Barco show controller. Each face is displayed for five minutes, with a brief period between each of these videos during which the sculpture is unlit. As a result, no more than 12 faces appear per hour during the summer. However, during the winter a version without the final one minute of puckering is shown, so the video segments then are only four minutes each. The video pattern also includes a three-minute water scene every half-hour and a 30-second fade-to-black every 15 minutes. If all the faces were shown consecutively, instead of randomly, they would each appear about once every eight days. A June 2007 article in the Chicago Sun-Times reported that many of the subjects who had their images digitized for the project had yet to either see their own images or hear of anyone who had seen them.
The spouting water from the faces of the towers appears to be flowing from the displayed subject's mouth from a nozzle located in the center of each interior face above the reflecting pool. Images are shown daily year-round, while the water feature only operates from May 1 to approximately October 31, weather permitting. The park is open to the public daily from 6 a.m. to 11 p.m.
Each tower is illuminated from within on three sides by approximately 70 color-changing Color Kinetics LED lighting fixtures per tower, while the fourth side features opposing Barco LED display screens. At night, some of the videos are replaced by images of nature or solid colors. Also at night, the other three sides of the fountain display changing colors. The outer Color Kinetics surfaces randomly display the translucent glow of one of eight colors along with each of the inner opposing faces. As a video sculpture with a variety of cascade and water spout fountain modes, the sculpture is a fluid, dynamic evolving artwork.
FountainCrown Fountain has both slits and a grate for drainage (pictured above right) to drain the of water per minute. When the videos are not on the front of the tower, water cascades down each of the facades. The water is filtered, pumped and recirculated through the fountain. Dual pump rooms below each tower draw water from a reservoir beneath the reflecting pool. There are 12 mechanical pumps that are regulated from a control room in the underground parking garage beneath the south tower of the fountain. The water in the reflecting pool has a depth of about .
Controversies
Before the fountain was completed in 2004, Art Institute of Chicago president James Wood felt the columns would be too tall and other community leaders felt that the height and scale of the project stemmed from a "pissing contest" with other park feature artists. Grant Park has been protected since 1836 by "forever open, clear and free" legislation that has been affirmed by four previous Illinois Supreme Court rulings. Aaron Montgomery Ward twice sued the city of Chicago in the 1890s to force it to remove buildings and structures from Grant Park, and to keep it from building new ones. As a result, the city has what are termed the Montgomery Ward height restrictions on buildings and structures in Grant Park. However, Crown Fountain and Jay Pritzker Pavilion, which stands tall, were exempt from the height restriction because they were classified as works of art and not buildings or structures.
In November 2006, Crown Fountain became the focus of a public controversy when the city added surveillance cameras atop each tower. Purchased through a $52 million Department of Homeland Security grant to the Chicago area, the cameras were part of a surveillance system augmenting eight other cameras covering all of Millennium Park. The city said the cameras, similar to those used throughout the city at high-crime areas and traffic intersections, were intended to remain on the towers for several months until permanent, less intrusive replacements were secured. City officials had consulted the architects who collaborated with Plensa on the tower designs, but Plensa himself had not been notified. Public reaction was negative, as bloggers and the artistic community decried the cameras on the towers as inappropriate and a blight. The city said that the cameras were largely for security reasons, but also partly to help park officials monitor burnt-out lights. The Chicago Tribune quickly published an article concerning the cameras as well as the public reaction, and the cameras were removed the next day. Plensa supported their removal.
Updating
In 2014, the hardware and software behind the fountain's operation were replaced. At the time there were plans to replace LED lighting with incandescent bulbs on each of the non-video display surfaces and to replace the video surface LEDs. Plensa, who maintained control of the video faces for the first two years of the fountain's operation, understands that future generations may wish to update the faces used in the rotation of videos to reflect changes in humanity going forward. In 2014, an additional 1000 faces were anticipated for 2016.
Critical receptionCrown Fountain, Trevi Fountain, and Buckingham Fountain, as well as natural water features such as Old Faithful, are examples of the ability of water to attract people and hold their attention. Crown Fountain has more interactivity than other Chicago fountains, such as Buckingham Fountain and Lorado Taft's Fountain of the Great Lakes and Fountain of Time (all but the last are in Grant Park). These other Chicago fountains are traditional in that they discourage viewer touching; Buckingham Fountain is surrounded by a fence, and Taft's fountains are surrounded by moats. In contrast, Crown Fountain provides an open invitation to play in the fountain's water.
[[Image:20071027 Chicago Picasso with kids.JPG|thumb|upright|alt=A large sculpture with kids climbing on it|left|Crown Fountain's inviting interactivity is likened to the nearby jungle gym-like Chicago Picasso.]]U.S. News & World Report describes the fountain as an exemplary feature of the city's numerous urban parks. Chicago Tribune architecture critic Blair Kamin, who is pleased with the sculptures' verticalness, says the fountain helps appropriately depict the modern 21st-century urban park. The Chicago Sun-Times describes the fountain as "eye-catching, crowd-friendly ... high-tech [and] ... contemporary". The New York Times calls the fountain an "extraordinary art object". Frommer's describes the fountain as public art at its best. The beauty of the fountain is, as the San Francisco Chronicle explains, that it is high-concept art for all to enjoy. The Financial Times refers to the fountain as a "techno-fountain". The fountain is praised for its technical features by industry magazines and has won various awards. The project won the 2006 Bombay Sapphire prize for its design work with glass. Critical reviews were not unanimous in their praise. One Chicago Tribune critic was not impressed with JumboTron-like art, although he conceded the participatory element reminded him in a positive way of the jungle gym element of the Chicago Picasso.
The fountain is featured on the cover of Philip Jodidio's 2005 book, Architecture: Art. Although Plensa is considered to be a conceptual artist, according to Jodidio, Plensa created a work whose architectural aspects are paramount. Its location juxtaposed with the Historic Michigan Boulevard District's skywall highlights these aspects. Jodidio considers the work to be a modernization of the gargoyle theme, and feels that the scale of the enlarged faces humanize the work and challenges the architecture. The towers are an integral part of the skyline that have achieved rare permanence for contemporary art.
See also
Crystal Fountains
List of public art in Chicago
Notes
References
External links
City of Chicago Millennium Park
Millennium Park map
City of Chicago Loop Community Map
Photos of controversial surveillance cameras in initial critical blogpost
Crown Fountain archives at Chicago Tribune''
Millennium Park
Outdoor sculptures in Chicago
2004 sculptures
American contemporary art
Contemporary works of art
Fountains in Illinois
Glass architecture
Glass works of art
Interactive art
Video art
Buildings and structures celebrating the third millennium
Buildings and structures completed in 2004
Buildings and structures in Chicago
Sculptures by Jaume Plensa
2004 establishments in Illinois | Crown Fountain | [
"Materials_science",
"Engineering"
] | 5,472 | [
"Glass architecture",
"Glass engineering and science"
] |
11,739,239 | https://en.wikipedia.org/wiki/Randle%20cycle | The Randle cycle, also known as the glucose fatty-acid cycle, is a metabolic process involving the cross inhibition of glucose and fatty acids for substrates. It is theorized to play a role in explaining type 2 diabetes and insulin resistance.
It was named for Philip Randle, who described it in 1963.
Cycle
The Randle cycle is a biochemical mechanism involving the competition between glucose and fatty acids for their oxidation and uptake in muscle and adipose tissue. The cycle controls fuel selection and adapts the substrate supply and demand in normal tissues. This cycle adds a nutrient-mediated fine tuning on top of the more coarse hormonal control on fuel metabolism. This adaptation to nutrient availability applies to the interaction between adipose tissue and muscle. Hormones that control adipose tissue lipolysis affect circulating concentrations of fatty acids; these in turn control the fuel selection in muscle. Mechanisms involved in the Randle Cycle include allosteric control, reversible phosphorylation and the expression of key enzymes. The energy balance from meals composed of differing macronutrient composition is identical, but the glucose and fat balances that contribute to the overall energy balance change reciprocally with meal composition.
Glucose is spared and rerouted
Fasted state
When fasting, the activation of lipolysis provides fatty acids as the preferred fuel source for respiration. In the liver β-oxidation of fatty acids fulfills the local energy needs and may lead to ketogenesis (creating ketone bodies out of fatty acids.) The ketone bodies are then used to meet the demands of tissues other than the liver. This inhibition of glucose oxidation at the level of pyruvate dehydrogenase preserves pyruvate and lactate, both of which are gluconeogenic precursors.
Fed state
The glucose fatty acid cycle is also observed in the fed state after a high-fat meal or during exercise. This is when plasma concentrations of fatty acids or ketone bodies are increased. The glucose that is not oxidized is then rerouted to glycogen. This rerouting to glycogen explains the rapid resynthesis of muscle glycogen after exercise as well as the increased glycogen content in muscles found in starvation or diabetes. This mechanism replenishes the intermediates of the citric acid cycle.
Inhibition of glycolytic pathway
The impairment of glucose metabolism by fatty acid oxidation is mediated by the short-term inhibition of several glycolytic processes. The extent of inhibition increases along the glycolytic pathway, being most severe at the level of pyruvate dehydrogenase and less severe at the level of glucose uptake and 6-phosphofructo-1-kinase (PFK-1). This sequence occurs because of the initial event, triggered by fatty acid oxidation, is an increase in the mitochondrial ratios of [acetyl-CoA]/[CoA] and [NADH]/[NAD+]. These both serve to inhibit pyruvate dehydrogenase activity. It has been proposed that these changes lead to an accumulation of cytosolic citrate, which in turn inhibits PFK-1, followed by an increase in glucose 6-phosphate, which eventually inhibits hexokinase.
Hemodynamic stress
Hemodynamic stress overrides fatty acid inhibition of glucose metabolism. During this time there is a decrease in substrate supply and an increase in the substrate demand. This leads to an activation of AMP-activated protein kinase (AMPK) as the AMP concentration rises in intracellular fluids and the ATP concentration decreases. The stress-induced activation of AMPK provides an immediate metabolic adaption and protects the heart from ischemic stress.
Fatty acid oxidation inhibition by malonyl-CoA
Malonyl-CoA signals glucose utilization and it controls the entry and oxidation of long-chain fatty acids (LCFA) in the mitochondria. Circulating glucose in the liver stimulates its uptake. Glucose oxidation produces citrate which can be converted to malonyl-CoA by acetyl-CoA carboxylase. Malonyl-CoA inhibits the carnitine palmitoyltransferase (CPT) that controls the entry and oxidation of LCFA. The glucose-derived malonyl-CoA prevents the oxidation of fatty acids and favors fatty acid esterification.
Cytosolic events controlling fatty acid oxidation
Malonyl-CoA concentration
The concentration of malonyl-CoA depends on the balance between acetyl-CoA carboxylase (ACC) and malonyl-CoA decarboxylase (MCD). AMP-activated protein kinase (AMPK) is reported to phosphorylate and inactivate liver ACC. This in turn decreases malonyl-CoA concentrations which stimulates fatty acid oxidation and ketogenesis by glucagon in the liver. AMPK phosphorylates and inactivates ACC in the liver and other tissues.
Integration of AMPK and ACC in the glucose-fatty acid cycle
Inhibition of fatty acid oxidation requires that ACC is active. Both AMPK and MCD are inactive and glucose uptake is stimulated. The LCFAs are then rerouted to esterification. These conditions exist in tissues rich in oxygen, in which AMPK is inactive and glucose inactivates the AMPK (researched in skeletal muscle).
The inhibition of MCD suppresses the oxidation of fatty acids and stimulates glucose oxidation. In a study on MCD deficient mice there was no difference in the oxidation of fatty acids and glucose in the heart under aerobic conditions. It is theorized that the overexpression of fatty acids being used makes up for the lack of MCD.
Fatty acid uptake
Long chain fatty acid uptake is mediated by several transporters, including FAT (fatty acid translocase)/CD36. CD36 deletion rescues lipotoxic cardiomyopathy. FAT/CD36 may be controlled by insulin and AMPK. Increased transport coupled to the formation of the CoA derivatives and the resulting AMPK activation should ensure efficient fatty acid uptake and metabolism.
Mitochondrial events controlling fuel selection
Fatty acids are preferentially oxidized because of the inactivation of PDH by fatty acid oxidation inhibiting glucose oxidation. This suggests that mitochondrial metabolism may control fuel selection. Cellular respiration is stimulated by fatty acids and this relates to an increase in the mitochondrial NADH to NAD+ ratio, suggesting that energy provision overtakes energy consumption. Switching from glucose to fatty acid oxidation leads to a bigger proportion of electrons being transported to complex 2 rather than complex 1 of the respiratory chain. This difference leads to a less efficient oxidative phosphorylation. By oxidizing fatty acids, mitochondria increase their respiration while increasing the production of ROS.
Fatty acids and insulin
Fatty acids may act directly upon the pancreatic β-cell to regulate glucose-stimulated insulin secretion. This effect is biphasic. Initially fatty acids potentiate the effects of glucose. After prolonged exposure to high fatty acid concentrations this changes to an inhibition. Randle suggested that the term fatty acid syndrome would be appropriate to apply to the biochemical syndrome resulting from the high concentration of fatty acids and the relationship to abnormalities of carbohydrate metabolism, including starvation, diabetes and Cushing’s syndrome.
References
Metabolism | Randle cycle | [
"Chemistry",
"Biology"
] | 1,522 | [
"Biochemistry",
"Metabolism",
"Cellular processes"
] |
11,739,278 | https://en.wikipedia.org/wiki/GD%20358 | GD 358 is a variable white dwarf star of the DBV type. Like other pulsating white dwarfs, its variability arises from non-radial gravity wave pulsations within the star itself. GD 358 was discovered during the 1958–1970 Lowell Observatory survey for high proper motion stars in the Northern Hemisphere. Although it did not have high proper motion, it was noticed that it was a very blue star, and hence might be a white dwarf. Greenstein confirmed this in 1969.
In 1968, Arlo U. Landolt discovered the first intrinsically variable white dwarf when he found that HL Tau 76 varied in brightness with a period of approximately 749.5 seconds, or 12.5 minutes. By the middle of the 1970s, a number of additional variable white dwarfs had been found, but, like HL Tau 76, they were all white dwarfs of spectral type DA, with hydrogen-dominated atmospheres. In 1982, calculations by Don Winget and his coworkers suggested that helium-atmosphere DB white dwarfs with surface temperatures around 19,000 K should also pulsate., p. L67. Winget then searched for such stars and found that GD 358 was a variable DB, or DBV, white dwarf. This was the first prediction of a class of variable stars before their observation., p. 89. In 1985, this star was given the variable-star designation V777 Herculis, which is also another name for this class of variable stars.; , p. 3525
Notes and references
Hercules (constellation)
Pulsating white dwarfs
Herculis, V777 | GD 358 | [
"Astronomy"
] | 336 | [
"Hercules (constellation)",
"Constellations"
] |
11,739,495 | https://en.wikipedia.org/wiki/HD%20136118 | HD 136118 is a star in the Serpens Caput section of the Serpens constellation. The star is too dim to be readily visible to the naked eye, having an apparent visual magnitude of 6.93. It is located at a distance of 165 light years from the Sun based on parallax, and is drifting closer with a radial velocity of −3 km/s.
This object is an F-type main-sequence star with a stellar classification of F7V.
The absolute visual magnitude of this star suggests that it has begun to evolve away from the main sequence. The abundances of the stellar atmosphere are similar to the Sun, and it has only a modest level of chromospheric activity. HD 136118 has 84% more mass compared to the Sun, and is 70% larger in radius. The star is an estimated 3.5 billion years old and is spinning with a projected rotational velocity of 8.5 km/s.
Brown dwarf companion
The astronomer Debra Fischer discovered a substellar companion, originally thought to be a very massive exoplanet, which was announced on February 7, 2002. Designated HD 136118 b, it is orbiting the host star with a period of . This object has a minimum mass of . On November 25, 2009, its inclination was calculated to be 163.1° and its true mass , classifying it as a brown dwarf. Later studies in 2022 and 2023 found true masses of about , closer to the minimum mass, but still classifying the companion as a brown dwarf by most definitions.
Due to its high mass the object is likely to be very hot and possibly glowing faintly. The orbit of the object has a semimajor axis of 1.45 astronomical units from the parent star, taking to complete one eccentric orbit.
See also
List of brown dwarfs
References
External links
F-type main-sequence stars
Brown dwarfs
Serpens
BD-01 3045
136118
074948 | HD 136118 | [
"Astronomy"
] | 403 | [
"Constellations",
"Serpens"
] |
11,740,016 | https://en.wikipedia.org/wiki/HD%202039 | HD 2039 is a yellow dwarf or yellow subgiant star in the constellation Phoenix. The star is not visible to the naked eye, and lies 280 light years away from the Sun. HD 2039 is a relatively stable star, and an exoplanet at least three times the mass of the planet Jupiter has been discovered in its orbit; this exoplanet, known as HD 2039 b, was the 100th exoplanet to be discovered.
Nomenclature
The designation HD 2039 from the Henry Draper Catalogue. The catalogue, which was published between 1918 and 1924, was based on the work of Annie Jump Cannon and her team between 1911 and 1915. HD 2039 does not have a common, colloquial name that is characteristic of stars like Sirius, Procyon, and Aldebaran.
Characteristics
HD 2039 is a stable G-type star, meaning it shines with white light that can be seen in the Sun. HD 2039 exhibits a radius approximately 40 percent larger than the Sun's. The star is slightly hotter than the Sun; while HD 2039 has a temperature of 5935 K, the Sun's surface temperature lies nearly 200 kelvins lower at 5778 K. HD 2039 is unusually metal-rich, which has attracted the attention of astrophysicists.
Distance and visibility
The star's magnitude as observed from Earth is 9; this signifies that the body is not visible with the naked eye, but can be seen with a telescope. HD 2039 lies roughly 280 light years from the Sun, which is about as far from the Sun as the second brightest star in the night sky, Canopus.
Planetary system
In 2002, a planet was found by the Anglo-Australian Planet Search team to be orbiting the star in a very eccentric orbit. It has a minimum mass more than four times that of Jupiter and has an orbital period of over three years. The planet orbits its star at a distance of approximately two AU away; the planet Earth, in comparison, orbits at a distance of one AU away from the Sun. HD 2039 b's discovery was reported quietly; no press release was provided by the observatory that discovered the star's planet, and no formal announcement of the planet's existence was made. The entity was the 100th exoplanet to have been verified by the scientific community.
See also
List of extrasolar planets
References
External links
The Extrasolar Planets Encyclopaedia: HD 2039
G-type main-sequence stars
G-type subgiants
002039
001931
Phoenix (constellation)
Planetary systems with one confirmed planet
Durchmusterung objects | HD 2039 | [
"Astronomy"
] | 539 | [
"Phoenix (constellation)",
"Constellations"
] |
11,740,178 | https://en.wikipedia.org/wiki/Primes%20in%20arithmetic%20progression | In number theory, primes in arithmetic progression are any sequence of at least three prime numbers that are consecutive terms in an arithmetic progression. An example is the sequence of primes (3, 7, 11), which is given by for .
According to the Green–Tao theorem, there exist arbitrarily long arithmetic progressions in the sequence of primes. Sometimes the phrase may also be used about primes which belong to an arithmetic progression which also contains composite numbers. For example, it can be used about primes in an arithmetic progression of the form , where a and b are coprime which according to Dirichlet's theorem on arithmetic progressions contains infinitely many primes, along with infinitely many composites.
For integer k ≥ 3, an AP-k (also called PAP-k) is any sequence of k primes in arithmetic progression. An AP-k can be written as k primes of the form a·n + b, for fixed integers a (called the common difference) and b, and k consecutive integer values of n. An AP-k is usually expressed with n = 0 to k − 1. This can always be achieved by defining b to be the first prime in the arithmetic progression.
Properties
Any given arithmetic progression of primes has a finite length. In 2004, Ben J. Green and Terence Tao settled an old conjecture by proving the Green–Tao theorem: The primes contain arbitrarily long arithmetic progressions. It follows immediately that there are infinitely many AP-k for any k.
If an AP-k does not begin with the prime k, then the common difference is a multiple of the primorial k# = 2·3·5·...·j, where j is the largest prime ≤ k.
Proof: Let the AP-k be a·n + b for k consecutive values of n. If a prime p does not divide a, then modular arithmetic says that p will divide every pth term of the arithmetic progression. (From H.J. Weber, Cor.10 in ``Exceptional Prime Number Twins, Triplets and Multiplets," arXiv:1102.3075[math.NT]. See also Theor.2.3 in ``Regularities of Twin, Triplet and Multiplet Prime Numbers," arXiv:1103.0447[math.NT], Global J.P.A.Math 8(2012), in press.) If the AP is prime for k consecutive values, then a must therefore be divisible by all primes p ≤ k.
This also shows that an AP with common difference a cannot contain more consecutive prime terms than the value of the smallest prime that does not divide a.
If k is prime then an AP-k can begin with k and have a common difference which is only a multiple of (k−1)# instead of k#. (From H. J. Weber, ``Less Regular Exceptional and Repeating Prime Number Multiplets," arXiv:1105.4092[math.NT], Sect.3.) For example, the AP-3 with primes {3, 5, 7} and common difference 2# = 2, or the AP-5 with primes {5, 11, 17, 23, 29} and common difference 4# = 6. It is conjectured that such examples exist for all primes k. , the largest prime for which this is confirmed is k = 19, for this AP-19 found by Wojciech Iżykowski in 2013:
19 + 4244193265542951705·17#·n, for n = 0 to 18.
It follows from widely believed conjectures, such as Dickson's conjecture and some variants of the prime k-tuple conjecture, that if p > 2 is the smallest prime not dividing a, then there are infinitely many AP-(p−1) with common difference a. For example, 5 is the smallest prime not dividing 6, so there is expected to be infinitely many AP-4 with common difference 6, which is called a sexy prime quadruplet. When a = 2, p = 3, it is the twin prime conjecture, with an "AP-2" of 2 primes (b, b + 2).
Minimal primes in AP
We minimize the last term.
Largest known primes in AP
For prime q, q# denotes the primorial 2·3·5·7·...·q.
, the longest known AP-k is an AP-27. Several examples are known for AP-26. The first to be discovered was found on April 12, 2010, by Benoît Perichon on a PlayStation 3 with software by Jarosław Wróblewski and Geoff Reynolds, ported to the PlayStation 3 by Bryan Little, in a distributed PrimeGrid project:
43142746595714191 + 23681770·23#·n, for n = 0 to 25. (23# = 223092870)
By the time the first AP-26 was found the search was divided into 131,436,182 segments by PrimeGrid and processed by 32/64bit CPUs, Nvidia CUDA GPUs, and Cell microprocessors around the world.
Before that, the record was an AP-25 found by Raanan Chermoni and Jarosław Wróblewski on May 17, 2008:
6171054912832631 + 366384·23#·n, for n = 0 to 24. (23# = 223092870)
The AP-25 search was divided into segments taking about 3 minutes on Athlon 64 and Wróblewski reported "I think Raanan went through less than 10,000,000 such segments" (this would have taken about 57 cpu years on Athlon 64).
The earlier record was an AP-24 found by Jarosław Wróblewski alone on January 18, 2007:
468395662504823 + 205619·23#·n, for n = 0 to 23.
For this Wróblewski reported he used a total of 75 computers: 15 64-bit Athlons, 15 dual core 64-bit Pentium D 805, 30 32-bit Athlons 2500, and 15 Durons 900.
The following table shows the largest known AP-k with the year of discovery and the number of decimal digits in the ending prime. Note that the largest known AP-k may be the end of an AP-(k+1). Some record setters choose to first compute a large set of primes of form c·p#+1 with fixed p, and then search for AP's among the values of c that produced a prime. This is reflected in the expression for some records. The expression can easily be rewritten as a·n + b.
Consecutive primes in arithmetic progression Consecutive primes in arithmetic progression refers to at least three consecutive primes which are consecutive terms in an arithmetic progression. Note that unlike an AP-k, all the other numbers between the terms of the progression must be composite. For example, the AP-3 {3, 7, 11} does not qualify, because 5 is also a prime.
For an integer k ≥ 3, a CPAP-k''' is k consecutive primes in arithmetic progression. It is conjectured there are arbitrarily long CPAP's. This would imply infinitely many CPAP-k for all k. The middle prime in a CPAP-3 is called a balanced prime. The largest known has 15004 digits.
The first known CPAP-10 was found in 1998 by Manfred Toplic in the distributed computing project CP10 which was organized by Harvey Dubner, Tony Forbes, Nik Lygeros, Michel Mizony and Paul Zimmermann. This CPAP-10 has the smallest possible common difference, 7# = 210. The only other known CPAP-10 as of 2018 was found by the same people in 2008.
If a CPAP-11 exists then it must have a common difference which is a multiple of 11# = 2310. The difference between the first and last of the 11 primes would therefore be a multiple of 23100. The requirement for at least 23090 composite numbers between the 11 primes makes it appear extremely hard to find a CPAP-11. Dubner and Zimmermann estimate it would be at least 1012 times harder than a CPAP-10.
Minimal consecutive primes in AP
The first occurrence of a CPAP-k is only known for k ≤ 6 .
Largest known consecutive primes in AP
The table shows the largest known case of k consecutive primes in arithmetic progression, for k = 3 to 10.xd is a d''-digit number used in one of the above records to ensure a small factor in unusually many of the required composites between the primes.
x106 = 115376 22283279672627497420 78637565852209646810 56709682233916942487 50925234318597647097 08315833909447378791
x153 = 9656383640115 03965472274037609810 69585305769447451085 87635040605371157826 98320398681243637298 57205796522034199218 09817841129732061363 55565433981118807417 = x253 % 379#
x253 = 1617599298905 320471304802538356587398499979 836255156671030473751281181199 911312259550734373874520536148 519300924327947507674746679858 816780182478724431966587843672 408773388445788142740274329621 811879827349575247851843514012 399313201211101277175684636727
See also
Cunningham chain
Szemerédi's theorem
PrimeGrid
Problems involving arithmetic progressions
Notes
References
Chris Caldwell, The Prime Glossary: arithmetic sequence, The Top Twenty: Arithmetic Progressions of Primes and The Top Twenty: Consecutive Primes in Arithmetic Progression, all from the Prime Pages.
Jarosław Wróblewski, How to search for 26 primes in arithmetic progression?
P. Erdős and P. Turán, On some sequences of integers, J. London Math. Soc. 11 (1936), 261–264.
Prime numbers | Primes in arithmetic progression | [
"Mathematics"
] | 2,311 | [
"Prime numbers",
"Mathematical objects",
"Numbers",
"Number theory"
] |
11,740,776 | https://en.wikipedia.org/wiki/HD%202039%20b | HD 2039 b is an extrasolar planet orbiting the star HD 2039. It is almost five times as massive as Jupiter and has a very eccentric orbit.
References
External links
The Extrasolar Planets Encyclopaedia: HD 2039
Phoenix (constellation)
Giant planets
Exoplanets discovered in 2002
Exoplanets detected by radial velocity | HD 2039 b | [
"Astronomy"
] | 72 | [
"Phoenix (constellation)",
"Constellations"
] |
11,740,955 | https://en.wikipedia.org/wiki/Thioformaldehyde | Thioformaldehyde is the organosulfur compound with the formula CH2S. It is the simplest thioaldehyde. This compound is not observed in the condensed state (solid or liquid) because it oligomerizes to 1,3,5-trithiane, which is a stable colorless compound with the same empirical formula.
Despite the instability of these concentrated forms, thioformaldehyde as a dilute gas has been extensively studied. For these purposes, it is produced by thermal decomposition of dimethyl disulfide. The molecule has been observed in the interstellar medium and has attracted much attention for its fundamental nature. The tendency of thioformaldehyde to form chains and rings is a manifestation of the double bond rule.
Although thioformaldehyde tends to oligomerize, many metal complexes are known. One example is Os(SCH2)(CO)2(PPh3)2.
References
Thioaldehydes | Thioformaldehyde | [
"Chemistry"
] | 208 | [
"Thioaldehydes",
"Functional groups"
] |
11,741,990 | https://en.wikipedia.org/wiki/Cyclin-dependent%20kinase%20inhibitor%20protein | A cyclin-dependent kinase inhibitor protein (also known as CKIs, CDIs, or CDKIs) is a protein that inhibits the enzyme cyclin-dependent kinase (CDK) and Cyclin activity by stopping the cell cycle if there are unfavorable conditions, therefore, acting as tumor suppressors. Cell cycle progression is stopped by Cyclin-dependent kinase inhibitor protein at the G1 phase. CKIs are vital proteins within the control system that point out whether the processes of DNA synthesis, mitosis, and cytokines control one another. When a malfunction hinders the successful completion of DNA synthesis in the G1 phase, it triggers a signal that delays or halts the progression to the S phase. Cyclin-dependent kinase inhibitor proteins are essential in the regulation of the cell cycle. If cell mutations surpass the cell cycle checkpoints during cell cycle regulation, it can result in various types of cancer.
CKI Inactivation Process
Cyclin-dependent kinase inhibitor proteins work by inactivating the CDKs through degradation. The typical inactivation mechanism of the CDK/Cyclin complex is based on binding a CDK inhibitor to the CDK cyclin complex and a partial conformational rotation of the CDK. The cyclin is thus forced to release the T loop and detach from the CDK. Then, the CDK inhibitor initiates a small helix into the cleft, blocking the cleft and blocking the active site of the CDK. Eventually, it releases the ATP out of the aperture of the CDK and deactivates it. Cyclin-dependent kinase inhibitor proteins use ATP as a phosphate contributor to phosphorylate serine and threonine residues.
Human cells contain many different cyclins that bind to different CDKs. CDKs and cyclins appear and activate at specific cell cycle phases. Seven cyclin-dependent kinase inhibitor proteins have been identified. They are p15, p16, p18, p19, p21, p27, and p57. These cyclin-dependent kinase inhibitor proteins emerge only in their specific cell cycle phase. Each Cyclin/CDK complex is specific to the part of the cell cycle phase. Each CDK and cyclin can be identified based on the location of the cell cycle. CKIs fall into two categories; those that inhibit CDK1, CDK2, and CDK5 and those that inhibit CDK4 and CDK6. These checkpoints' cell cycle blocks at both the G1/S and G2/M checkpoints are consistent with the inhibition profiles of the enzymes.
Discovery
The discovery of Cyclin-dependent kinase inhibitor proteins in 1990 opened the door in how we think about cell cycle control. It has steered to various other fields of study such as developmental biology, cell biology and cancer research. The discovery of the first CKIs in yeast (Far1) and P21 in mammals has led to research on family of molecules. Further research has demonstrates that Cdks, cyclins and CKIs play essential roles in processes such as transcription, epigenetic regulation, metabolism, stem cell self-renewal, neuronal functions and spermatogenesis.
In mammals, p27, a cyclin-dependent kinase inhibitor protein, helps control CDK activity in G1. Also, the INK4 proteins help stop the G1-CDK activity when they encounter anti-proliferative signals within the environment. CKIs help promote the specific inhibitory signals that contain the cell from entering the S phase. In budding yeast, SIC 1 and Roughex, RUX, in Drosophila possess the same contributions that contribute to the stability of G1 cells. They are expressed in higher numbers in G1 cells to make sure that no S or M CDKs are in the cell.
Structure
In the cyclin-dependent kinase (CDK) family, or CDK, Cyclin, and CKIs, serine/threonine kinases play an integral role in regulating the eukaryotic cell cycle. The structure of CDK2-CyclinA and p27 is determined by crystallography, demonstrating that the inhibitor of p27 stretches at the top of the Cyclin-CDK complex. The amino terminal of p27 has an RXL motif exhibiting a hydrophobic patch of cyclin A. The carboxyl-terminal end of the p27 fragment interacts with the beta sheet of CDKs, causing interference with the structure; p27 slides into the ATP-binding site of CDK2 and inhibits ATP binding.
Clinical significance
Role in cancer: Cyclin-dependent kinase inhibitor (CKI) mutants are frequent in human cancers. The function of CKI is to stop cell growth when there are mistakes due to DNA damage. Once a cell is stopped at a checkpoint due to DNA damage, either the damage is repaired or the cell is induced to perform apoptosis. However, if CKI’s mutations don’t stop the cell, Cyclin D is transcribed. It moves into the cytoplasm and eventually activates a specific cyclin-dependent kinase (CDK). The active cyclin/CDK complex then phosphorylates proteins, activates them, and sends the cell into the next phase of the cell cycle. Since the cell with damaged DNA is not stopped, the cell eventually moves out of the G1 checkpoint and prepares for DNA synthesis. When there is uncontrolled cell growth, it can lead to cancer cells due to the inactivation of the CKIs.
Associated gene and target
References
External links
Protein domains | Cyclin-dependent kinase inhibitor protein | [
"Biology"
] | 1,176 | [
"Protein domains",
"Protein classification"
] |
11,742,171 | https://en.wikipedia.org/wiki/Jingui%20Yaol%C3%BCe | Jingui Yaolüe (), Essential Prescriptions from the Golden Cabinet is a classic clinical book of traditional Chinese medicine written by Zhang Zhongjing (150-219) at the end of the Eastern Han dynasty and was first published in the Northern Song dynasty. The oldest known extant copy, believed to be bibliographically closest to the original, dates to 1340 and was printed with woodcuts in the early Ming dynasty.
There is an annotated English translation by Luo Xiwen, with three hundred modern case histories titled: Synopsis of Prescriptions of the Golden Chamber with 300 Cases. First published in 1995 by New World Press.
References
External links
Chinese source text
Chinese medical texts
Han dynasty texts | Jingui Yaolüe | [
"Chemistry"
] | 147 | [
"Pharmacology",
"Pharmacology stubs",
"Medicinal chemistry stubs"
] |
11,742,691 | https://en.wikipedia.org/wiki/Thienamycin | Thienamycin (also known as thienpenem) is one of the most potent naturally produced antibiotics known thus far, discovered in Streptomyces cattleya in 1976. Thienamycin has excellent activity against both Gram-positive and Gram-negative bacteria and is resistant to bacterial β-lactamase enzymes. Thienamycin is a zwitterion at pH 7.
History
In 1976, fermentation broths obtained from the soil bacterium Streptomyces cattleya were found to be active in a screen for inhibitors of peptidoglycan biosynthesis. Initial attempts to isolate the active compound proved difficult due to its chemical instability. After many attempts and extensive purification, the material was finally isolated in >90% purity, allowing for the structural elucidation of thienamycin in 1979.
Thienamycin was the first among the naturally occurring class of carbapenem antibiotics to be discovered and isolated. Carbapenems are similar in structure to their antibiotic “cousins” the penicillins. Like penicillins, carbapenems contain a β-lactam ring (cyclic amide) fused to a five-membered ring. Carbapenems differ in structure from penicillins in that within the five-membered ring a sulfur is replaced by a carbon atom (C1) and an unsaturation is present between C2 and C3 in the five-membered ring.
Mechanism of action
In vitro, thienamycin employs a similar mode of action as penicillins through disrupting the cell wall synthesis (peptidoglycan biosynthesis) of various Gram-positive and Gram-negative bacteria (Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa to name a few). Although thienamycin binds to all of the penicillin-binding proteins (PBPs) in Escherichia coli, it preferentially binds to PBP-1 and PBP-2, which are both associated with the elongation of the cell wall.
Unlike penicillins, which are rendered ineffective through rapid hydrolysis by the β-lactamase enzyme present in some strains of bacteria, thienamycin remains antimicrobially active. Thienamycin displayed high activity against bacteria that were resistant to other β-lactamase-stable compounds (cephalosporins), highlighting the superiority of thienamycin as an antibiotic among β-lactams.
Biosynthesis
The formation of thienamycin is thought to occur through a different pathway from classic β-lactams (penicillins, cephalosporins). Production of classic β-lactams in both fungi and bacteria occur through two steps: First, the condensation of -cysteine, -valine, and -α-aminoadipic acid by ACV synthetase (ACVS, a nonribosomal peptide synthetase) and then cyclization of this formed tripeptide by isopenicillin N synthetase (IPNS).
The gene cluster (thn) for the biosynthesis of thienamycin of S. cattleya was identified and sequenced in 2003, lending insight into the biosynthetic mechanism for thienamycin formation. The biosynthesis is thought to share features with the biosynthesis of the simple carbapenems, beginning with the condensation of malonyl-CoA with glutamate-5-semialdehyde to form the pyrroline ring. The β-lactam is then formed by a β-lactam synthetase, which makes use of ATP, providing a carbapenam. At some later point, oxidation to the carbapenem and ring inversions must occur.
The hydroxyethyl side chain of thienamycin is thought to be a result of two separate methyl transfers from S-adenosyl methionine. According to the proposed gene functions, ThnK, ThnL, and ThnP could catalyze these methyl-transfer steps. A β-lactam synthetase (ThnM) is thought to catalyze the formation of the β-lactam ring fused to the five-membered ring. How the cysteaminyl side-chain is incorporated is largely unknown, although ThnT, ThnR, and ThnH are involved in the processing of CoA to cysteamine for use in the pathway. Various oxidations complete the biosynthesis.
Total synthesis
Due to low titre and to difficulties in isolating and purifying thienamycin produced by fermentation, total synthesis is the preferred method for commercial production. Numerous methods are available in the literature for the total synthesis of thienamycin. One synthetic route is given in Figure 3.
The starting β-lactam for the pathway given above can be synthesized using the following method (Figure 4):
Clinical use
Since thienamycin decomposes in the presence of water, it is impractical for the clinical treatment of bacterial infections, so stable derivatives were created for medicinal consumption. One such derivative, imipenem, was formulated in 1985. Imipenem, an N-formimidoyl derivative of thienamycin, is rapidly metabolized by a renal dipeptidase enzyme found in the human body. To prevent its rapid degradation, imipenem is normally coadministered with cilastatin, an inhibitor of this enzyme.
References
Carbapenem antibiotics
Thioethers
Total synthesis
Amines
Carboxylic acids
Secondary alcohols | Thienamycin | [
"Chemistry"
] | 1,185 | [
"Carboxylic acids",
"Functional groups",
"Chemical synthesis",
"Total synthesis",
"Amines",
"Bases (chemistry)"
] |
11,743,104 | https://en.wikipedia.org/wiki/Infinite%20alleles%20model | The infinite alleles model is a mathematical model for calculating genetic mutations. The Japanese geneticist Motoo Kimura and American geneticist James F. Crow (1964) introduced the infinite alleles model, an attempt to determine for a finite diploid population what proportion of loci would be homozygous. This was, in part, motivated by assertions by other geneticists that more than 50 percent of Drosophila loci were heterozygous, a claim they initially doubted. In order to answer this question they assumed first, that there were a large enough number of alleles so that any mutation would lead to a different allele (that is the probability of back mutation to the original allele would be low enough to be negligible); and second, that the mutations would result in a number of different outcomes from neutral to deleterious.
They determined that in the neutral case, the probability that an individual would be homozygous, F, was:
where u is the mutation rate, and Ne is the effective population size. The effective number of alleles n maintained in a population is defined as the inverse of the homozygosity, that is
which is a lower bound for the actual number of alleles in the population.
If the effective population is large, then a large number of alleles can be maintained. However, this result only holds for the neutral case, and is not necessarily true for the case when some alleles are subject to selection, i.e. more or less fit than others, for example when the fittest genotype is a heterozygote (a situation often referred to as overdominance or heterosis).
In the case of overdominance, because Mendel's second law (the law of segregation) necessarily results in the production of homozygotes (which are by definition in this case, less fit), this means that population will always harbor a number of less fit individuals, which leads to a decrease in the average fitness of the population. This is sometimes referred to as genetic load, in this case it is a special kind of load known as segregational load. Crow and Kimura showed that at equilibrium conditions, for a given strength of selection (s), that there would be an upper limit to the number of fitter alleles (polymorphisms) that a population could harbor for a particular locus. Beyond this number of alleles, the selective advantage of presence of those alleles in heterozygous genotypes would be cancelled out by continual generation of less fit homozygous genotypes.
These results became important in the formation of the neutral theory, because neutral (or nearly neutral) alleles create no such segregational load, and allow for the accumulation of a great deal of polymorphism. When Richard Lewontin and J. Hubby published their groundbreaking results in 1966 which showed high levels of genetic variation in Drosophila via protein electrophoresis, the theoretical results from the infinite alleles model were used by Kimura and others to support the idea that this variation would have to be neutral (or result in excess segregational load).
References
See also
Infinite sites model
Evolutionary biology
Population genetics
Mathematical and theoretical biology | Infinite alleles model | [
"Mathematics",
"Biology"
] | 665 | [
"Evolutionary biology",
"Applied mathematics",
"Mathematical and theoretical biology"
] |
11,743,518 | https://en.wikipedia.org/wiki/Lolland%20Hydrogen%20Community | Denmark's first full-scale wind-Hydrogen energy plant and testing facility, the Lolland Hydrogen Community, began operation in May 2007. It is also the European Union's first full-scale Hydrogen Community Demonstration facility for residential Fuel Cell Combined Heat and Power (CHP).
Phase 3 of the project that ran until 2012 and was the installing of fuel cell micro combined heat and power plants.
Located in the city of Nakskov on the island of Lolland, where wind power is abundant, the hydrogen energy plant was received with funding from the Danish Energy Authority, which is a joint partnership between the Municipality of Lolland, IRD Fuel Cells, and Baltic Sea Solutions.
The island of Lolland is producing 50% more energy from renewable energy sources than it consumes, and the hydrogen project was seeking to locally store excess wind power in the form of hydrogen, for use in residential and industrial facilities.
Hydrogen is produced by using excess wind power to electrolyze water to produce hydrogen and oxygen. The oxygen is used in the municipal water treatment plant nearby to speed up the biological process. The hydrogen is stored in low-pressure storage tanks at six bars and fuels two PEM Fuel Cell Micro Combined Heat and Power (CHP) stations of 2 kilowatts (kW) and 6.5 kW, respectively.
See also
Hydrogen economy
Renewable energy in Iceland
Wind-hydrogen hybrid power system
Wind power in Denmark
References
Sustainable energy
Electrochemistry
Energy conversion
Hydrogen production
Power stations in Denmark
Hydrogen economy
Lolland | Lolland Hydrogen Community | [
"Chemistry"
] | 305 | [
"Electrochemistry",
"Physical chemistry stubs",
"Electrochemistry stubs"
] |
11,744,329 | https://en.wikipedia.org/wiki/Disincentive | A disincentive is something that discourages an individual or an organization from behaving in a certain way. Disincentives may fall within the scope of economics, social issues or politics. For comparison, incentives encourage behaving in a desirable way.
Economic
Economic disincentives are any factors that demotivate an individual from following a particular path. For example, if pay for a particular task is too low, that prospective employee may choose to avoid following that particular employment route. Similarly, if an individual has a particular medical issue and the employer is unable or unwilling to accommodate his or her impediment, that individual will choose to look elsewhere for work.
Politics
The furtherance of disincentives is a tool used by politicians both in foreign policy and domestic policy. Disincentives in foreign policy are means and tactics used to deter an adversary from belligerence. In domestic policy, a disincentive is a tool that aims to deter an individual from breaking the law or otherwise reoffending.
See also
Cognitive evaluation theory
References
Motivation | Disincentive | [
"Biology"
] | 219 | [
"Ethology",
"Behavior",
"Motivation",
"Human behavior"
] |
11,744,449 | https://en.wikipedia.org/wiki/Scattering%20from%20rough%20surfaces | Surface roughness scattering or interface roughness scattering is the elastic scattering of particles against a rough solid surface or imperfect interface between two different materials. This effect has been observed in classical systems, such as microparticle scattering, as well as quantum systems, where it arises electronic devices, such as field effect transistors and quantum cascade lasers.
Classical description
In the classical mechanics framework, a rough surface, such as a machined metal surface, randomizes the probability distribution function governing the incoming particles, leading to net momentum loss of the particle flux.
Quantum description
In the quantum mechanical framework, this scattering is most noticeable in confined systems, in which the energies for charge carriers are determined by the locations of interfaces. An example of such a system is a quantum well, which may be constructed from a sandwich of different layers of semiconductor. Variations in the thickness of these layers therefore causes the energy of particles to be dependent on their in-plane location in the layer. Classification of the roughness at a given position, , is complex, but as in the classical models, it has been modeled as a Gaussian distribution by some researchers
This assumption may be formulated in terms of the ensemble average for some given characteristic height, , and correlation length, , such that
Types of Scattering
Selective Scattering : In selective Scattering scattering depends upon the wavelength of light.
Mie scattering : Mie theory can describe how electromagnetic waves interact with homogeneously spherical particles. However, a theory for homogeneous spheres will completely fail to predict polarization effects. When the size of the molecules is greater than the wavelength of light, the result is a non-uniform scattering of light.
Lambertian Scattering: This type of scattering occurs when a surface has microscopic irregularities that scatter light perfectly uniformly in all directions, causing it to appear equally bright from all viewing angles.
Subsurface Scattering: This type of scattering occurs when light scatters within a material before exiting the surface at a different point.
Isotropic crystal scattering (aka powder diffraction): This type of scattering occurs when every crystalline orientation is represented equally in a powdered sample. Powder X-ray diffraction (PXRD) operates under the assumption that the sample is randomly arranged such that each plane will be represented in the signal.
Notes
Scattering | Scattering from rough surfaces | [
"Physics",
"Chemistry",
"Materials_science"
] | 459 | [
"Condensed matter physics",
"Scattering",
"Particle physics",
"Nuclear physics"
] |
11,745,881 | https://en.wikipedia.org/wiki/Ammonium%20heptamolybdate | Ammonium heptamolybdate is the inorganic compound whose chemical formula is (NH4)6Mo7O24, normally encountered as the tetrahydrate. A dihydrate is also known. It is a colorless solid, often referred to as ammonium paramolybdate or simply as ammonium molybdate, although "ammonium molybdate" can also refer to ammonium orthomolybdate, (NH4)2MoO4, and several other compounds. It is one of the more common molybdenum compounds.
Synthesis
Ammonium heptamolybdate is easily prepared by dissolving molybdenum trioxide in an excess of aqueous ammonia and evaporating the solution at room temperature. While the solution evaporates, the excess of ammonia escapes. This method results in the formation of six-sided transparent prisms of the tetrahydrate of ammonium heptamolybdate.
Solutions of ammonium paramolybdate react with acids to form molybdic acid and an ammonium salt. The pH value of a concentrated solution will lie between 5 and 6.
Structure
The compound was first analyzed crystallographically by Lindqvist, but has been reanalyzed. All Mo centers are octahedral. Some oxide ligands are terminal, some doubly bridging, and a few are triply bridging ligands.
Uses
as an analytical reagent to measure the amount of phosphates, silicates, arsenates and lead in aqueous solution (e.g. pigments, river water, sea water etc.)
in the production of molybdenum metal and ceramics
in the preparation of dehydrogenation and desulfurization catalysts
in the fixing of metals
in electroplating
in fertilizers for crops.
as a negative stain in biological electron microscopy, typically in the 3–5% (vol/vol) concentration range and in the presence of trehalose; or at saturated concentration to perform cryo-negative staining.
For the detection of recreational drugs as a component of the Froehde reagent
Related compounds
Potassium heptamolybdate, also obtained as the tetrahydrate, is very similar to the ammonium salt.
Safety
Molybdates are typically of low toxicity, so much so that few reports of incidents have ever been reported.
References
See also
Phosphate test aka Deniges' method links to here.
Molybdates
Ammonium compounds | Ammonium heptamolybdate | [
"Chemistry"
] | 535 | [
"Ammonium compounds",
"Salts"
] |
11,746,064 | https://en.wikipedia.org/wiki/San%20Marino%20Scale | The San Marino Scale is a suggested scale for assessing risks associated with deliberate transmissions from Earth aimed to possible extraterrestrial intelligent life. The scale evaluates the significance of transmissions from Earth as a function of signal intensity and information content. The scale was suggested by Iván Almár at a conference in San Marino in 2005.
The radio output of Jupiter, Saturn and Neptune is not considered in the model.
The San Marino Scale was subsequently adopted by the SETI Permanent Study Group of the International Academy of Astronautics at its 2007 meeting in Hyderabad, India.
Calculation
In the original presentation given by Almár, the San Marino Index, SMI, of a given event is calculated as the sum of two terms.
The first term, I, is based on the intensity of the signal relative to the background noise in the same frequency band. This term is logarithmic, and calculated as:
For example, a signal which is 100 times more intense than the background noise at the same frequency and bandwidth would have an I value of two.
The second term, C, is more subjective and relates to the content, aiming, timing, and character of the signal. A C rating of one is something like a stray radar pulse, lacking any information content and randomly directed. A C rating of five is a deliberate reply to an extraterrestrial signal.
Rating scale
References
Extraterrestrial life
Search for extraterrestrial intelligence
Interstellar messages | San Marino Scale | [
"Astronomy",
"Biology"
] | 290 | [
"Biological hypotheses",
"Extraterrestrial life",
"Astronomical controversies",
"Hypothetical life forms"
] |
11,746,531 | https://en.wikipedia.org/wiki/Eureka%20Prometheus%20Project | The Eureka PROMETHEUS Project (PROgraMme for a European Traffic of Highest Efficiency and Unprecedented Safety, 1987–1995) was the largest R&D project ever in the field of driverless cars. It received in funding from the EUREKA member states, and defined the state of the art of autonomous vehicles. Numerous universities and car manufacturers participated in this Pan-European project.
In formulating the project, the automotive and industrial partners recognised the need for a wide range of skills and cooperated with over forty research establishments to create a programme consisting of seven sub-projects. Under a steering committee were three projects on industrial research and four on basic research.
Industrial research
PRO-CAR : Driver assistance by computer systems
PRO-NET : Vehicle-to-vehicle communication
PRO-ROAD : Vehicle-to-environment communication
Basic Research
PRO-ART : Methods and systems of artificial intelligence
PRO-CHIP: Custom hardware for intelligent processing in vehicles
PRO-COM : Methods and standards for communication
PRO-GEN : Traffic scenario for new assessment and introduction of new systems
In 1987, some UK Universities expressed concern that the industrial focus on the project neglected import traffic safety issues such as pedestrian protection. PRO-GEN project leader, the UK Government's Transport and Road Research Laboratory noted that research activities should 'in some way, further the aims of the vehicle companies.
Results
The project culminated in a 'Board Members Meeting' (BMM) on 18–20 October 1994 in Paris. Projects demonstrated ('Common European Demonstrators') were:
CED 1 : Vision Enhancement
CED 2-1 : Friction Monitoring and Vehicle Dynamics
CED 2-2 : Lane Keeping Support
CED 2-3 : Visibility Range Monitoring
CED 2-4 : Driver Status Monitoring
CED 3 : Collision Avoidance
CED 4 : Cooperative Driving
CED 5 : Autonomous Intelligent Cruise Control
CED 6 : Automatic Emergency Call
CED 7 : Fleet Management
CED 9 : Dual Mode Route Guidance
CED 10: Travel and Traffic Information Systems
PROMETHEUS PRO-ART profited from the participation of Ernst Dickmanns, the 1980s pioneer of driverless cars, and his team at Bundeswehr Universität München, collaborating with Daimler-Benz. A first culmination point was achieved in 1994, when their twin robot vehicles VaMP and VITA-2 drove more than on a Paris multi-lane highway in standard heavy traffic at speeds up to . They demonstrated autonomous driving in free lanes, convoy driving, automatic tracking of other vehicles, and lane changes left and right with autonomous passing of other cars.
Participants
There were upwards of 600 commercial members that participated in some way in the Prometheus Project, however, notable ones include
Aeritalia
Aerospatiale
ASEA-Brown-Bovei
BASF
BMW
Bosch
British Aerospace
Bull
CASA
CGE
Fiat
GEC
Imperial Chemicals, Inc.
ICL
Italtel
Matra
MBB
Mercedes
Montedison
Nokia
Olivetti
Peugeot
Philips
Plessey
Renault
Saab
SGS-Thompson
Siemens
Thomson
Volkswagen
Volvo
In addition to commercial participation, there were multiple countries that assisted with the project. These include
France
Germany
Italy
Spain
The UK
The Netherlands
Sweden
Austria
Belgium
Denmark
Norway
Switzerland
Finland
Portugal
Greece
Ireland
Luxembourg
Turkey
Yugoslavia
Iceland
Canada
The United States
Hungary
See also
Driverless car
DARPA Grand Challenge
ARGO Project on autonomous cars
ELROB trials
Grand Cooperative Driving Challenge 2011, International Competition
Notes
Self-driving cars
Eureka (organisation)
Robotics competitions | Eureka Prometheus Project | [
"Engineering"
] | 683 | [
"Automotive engineering",
"Self-driving cars"
] |
11,746,640 | https://en.wikipedia.org/wiki/ProSyst | ProSyst Software GmbH was founded in Cologne in 1997 as a company specializing in Java software and middleware. ProSyst's first commercial application was a Java EE application server. In 2000, the company sold this server technology and has since focused completely on OSGi solutions.
In 1999, ProSyst was among the first companies to join the OSGi Alliance and since then has made important contributions to the development of each release of OSGi specifications (Release 1–4). ProSyst is a member of the OSGi Alliance board of directors alongside IBM, Nokia, NTT, Siemens, Oracle Corporation, Samsung, Motorola and Telcordia. Additionally, members of ProSyst staff serve in several positions on the OSGi Alliance.
In recent years ProSyst set its focus exclusively on the development of OSGi related software such as Frameworks, Bundles, Remote Management Systems and OSGi tools for developers including a full SDK available for download. ProSyst's OSGi applications are used by SmartHome devices, mobile phone manufacturers, network equipment providers (in CPEs), white goods manufacturers, car manufacturers and in the eHealth market.
ProSyst employs more than 120 Java and OSGi experts and offers OSGi related training, support (SLAs), technical consulting and development services.
As a member, ProSyst contributes to OSGi, Eclipse, Java Community Process, Nokia Forum Pro and the CVTA Connected Vehicle Trade Association.
Prosyst was acquired by Bosch in February 2015, and was merged into Bosch Group's software and systems unit Bosch Software Innovations GmbH.
Notable products
Commercial off-the-shelf products around OSGi mBS
Reduced-size Java client from 1999
References
Companies based in Cologne
Java platform software
Middleware
Software companies of Germany | ProSyst | [
"Technology",
"Engineering"
] | 362 | [
"Software engineering",
"Middleware",
"IT infrastructure"
] |
11,746,968 | https://en.wikipedia.org/wiki/Dialyte%20lens | A dialyte lens (sometimes called a dialyt) is a compound lens design that corrects optical aberrations where the lens elements are widely air-spaced. The design is used to save on the amount of glass used for specific elements or where elements can not be cemented because they have dissimilar curvatures. The word dialyte means "parted", "loose" or "separated" in Greek.
Design
In its simplest form, a dialyte can be formed by separating the elements in a cemented achromatic doublet of positive and negative lenses, although the powers of the individual elements must be increased to compensate.
Applications
Telescopes
The idea of widely separating the color correcting elements of a lens dates back to W. F. Hamilton's 1814 catadioptric Hamiltonian telescope and Alexander Rogers' 1828 proposals for a dialytic refractor. The goal was to combine a large crown glass objective with a much smaller flint glass downstream to make an achromatic lens since flint glass at that time was very expensive. Dialyte designs were also used in the Schupmann medial telescope designed by in German optician Ludwig Schupmann near the end of the 19th century, in John Wall's 1999 "Zerochromat" retrofocally corrected dialytic refractor and the Russian made "TAL Apolar125" telescope which uses 6 elements arranged in three widely separated groups.
Photography
There are many types of dialyte camera lenses. One popular design is perfectly symmetric, which provides good correction for many aberrations. This consists of two air-spaced achromatic doublets arranged back-to-back around a central stop, or four air spaced lens elements in total: the outer pair is biconvex and the inner pair is biconcave; one example is the Celor. The Swiss mathematician Emil von Höegh, who had designed the popular Dagor anastigmat lens for Goerz in 1892, continued to refine that design, resulting in the Goerz Dagor Type B lens of 1899, later renamed to Celor and Syntor.
The Aviar lens (Taylor Hobson) designed by Arthur Warmisham (1917) is similar but is considered to have a different origin, from the splitting of the central biconcave element of the Cooke triplet. The resulting two biconcave elements are closer together than in the Dialyte/Celor design.
Enlarging
Since the aberrations remain constant over a wide range of object distances, and is favourable for fairly wide apertures, this design proved useful for enlarging lenses.
See also
List of telescope types.
References
Photographic lenses
Optics
Lens designers
Camera lenses by year of introduction | Dialyte lens | [
"Physics",
"Chemistry"
] | 557 | [
"Applied and interdisciplinary physics",
"Optics",
" molecular",
"Atomic",
" and optical physics"
] |
13,246,370 | https://en.wikipedia.org/wiki/Gilbert%20cell | In electronics, the Gilbert cell is a type of frequency mixer. It produces output signals proportional to the product of two input signals. Such circuits are widely used for frequency conversion in radio systems. The advantage of this circuit is the output current is an accurate multiplication of the (differential) base currents of both inputs. As a mixer, its balanced operation cancels out many unwanted mixing products, resulting in a "cleaner" output.
It is a generalized case of an early circuit first used by Howard Jones in 1963, invented independently and greatly augmented by Barrie Gilbert in 1967. It is a specific example of "translinear" design, a current-mode approach to analog circuit design. The specific property of this cell is that the differential output current is a precise algebraic product of its two differential analog current inputs.
Function
There is little difference between the Jones cell and the translinear multiplier in this topology. In both forms, two differential amplifier stages are formed by emitter-coupled transistor pairs (Q1/Q4, Q3/Q5) whose outputs are connected (currents summed) with opposite phases. The emitter junctions of these amplifier stages are fed by the collectors of a third differential pair (Q2/Q6). The output currents of Q2/Q6 become emitter currents for the differential amplifiers. Simplified, the output current of an individual transistor is given by ic = gm vbe. Its transconductance gm is (at ) about . Combining these equations gives . However, IC here is given by vbe,rf gm,rf. Hence , which is a multiplication of vbe,lo and vbe,rf. Combining the two different stages output currents yields four-quadrant operation.
The Jones topology can be generalized by "stacking" any number of pairs of differential pairs (whose two differential inputs and two differential outputs are likewise connected out-of-phase and in-phase, respectively) on top of a conventional Jones cell, resulting in a circuit that retains the balanced nature of the Jones cell's operation. Specifically, the differential output current would now be proportional to the product of an arbitrary number of differential inputs (or some translinear function thereof). However, the utility of this generalization in practical microelectronics settings is limited due to the large voltage headroom needed to keep all of the transistors in the proper (forward-active) region of operation.
However, in the cells later invented by Gilbert, shown in the figure on the right, there are two additional diode-connected transistors (labeled as V1 and V2). This is a crucial difference because they generate the logarithm of the associated differential (X) input current so that the exponential characteristics of the following transistors result in an ideally perfect multiplication of these input currents with the remaining pair of (Y) currents. This additional diode cell topology is typically used when a low distortion voltage-controlled amplifier (VCA) is required. This topology is rarely used in RF mixer/modulator applications for various reasons, one being that the linearity advantage of the top linearized cascode is minimal due to the near-square wave drive signals to these bases. The drive is less likely to be a fast-edge squarewave at very high frequencies when there may be some advantage in the linearization.
Nowadays, functionally similar circuits can be constructed using CMOS or BiCMOS cells.
See also
NE612, oscillator, and mixer.
References
Frequency mixers
Analog circuits
Radio electronics | Gilbert cell | [
"Engineering"
] | 728 | [
"Analog circuits",
"Electronic engineering",
"Radio electronics",
"Frequency mixers"
] |
13,246,418 | https://en.wikipedia.org/wiki/Industrial%20fan | Industrial fans and blowers are machines whose primary function is to provide and accommodate a large flow of air or gas to various parts of a building or other structures. This is achieved by rotating a number of blades, connected to a hub and shaft, and driven by a motor or turbine. The flow rates of these mechanical fans range from approximately to per minute. A blower is another name for a fan that operates where the resistance to the flow is primarily on the downstream side of the fan.
Functions and industries
There are many uses for the continuous flow of air or gas that industrial fans generate, including combustion, ventilation, aeration, particulate transport, exhaust, cooling, air-cleaning, and drying, to name a few. The industries served include electrical power production, pollution control, metal manufacturing and processing, cement production, mining, petrochemical, food processing, cryogenics, and clean rooms.
Centrifugal fans and axial fans
Most industrial fans may be categorized into one of two general types: centrifugal fans and axial fans.
Centrifugal
The centrifugal design uses the centrifugal force generated by a rotating disk, with blades mounted at right angles to the disk, to impart movement to the air or gas and increase its pressure. The assembly of the hub, disk and blades is known as the fan wheel, and often includes other components with aerodynamic or structural functions. The centrifugal fan wheel is typically contained within a scroll-shaped fan housing, resembling the shell of the nautilus sea creature with a central hole. The air or gas inside the spinning fan is thrown off the outside of the wheel, to an outlet at the housing's largest diameter. This simultaneously draws more air or gas into the wheel through the central hole. Inlet and outlet ducting are often attached to the fan's housing, to supply and/or exhaust the air or gas to the industry's requirements.
There are many varieties of centrifugal fans, which may have fan wheels that range from less than 3 cm to over in diameter.
Axial
The axial design uses axial forces to achieve the movement of the air or gas, spinning a central hub with blades extending radially from its outer diameter. The fluid is moved parallel to the fan wheel's shaft, or axis of rotation. The axial fan is often contained within a short section of cylindrical ductwork, to which inlet and outlet ducting can be connected.
Axial fan types have fan wheels with diameters that usually range from less than a foot (0.3 meters) to over , although axial cooling tower fan wheels may exceed in diameter.
In general, axial fans are used where the principal requirement is for a large volume of flow, and the centrifugal design where both flow and higher pressures are required. Axial fans provide huge airflow at low pressures. They draw air parallel to the axis and force it straight out.
Design paths
There are several paths to determining a fan design for an application.
For industries where the application requirements do not vary greatly and applicable fan designs have diameters of around or less, a standard or pre-engineered design might be selected.
When the application involves more complex specifications or a larger fan, then a design based on an existing model configuration will often satisfy the requirements. Many model configurations already cover the range of current industry processes. An appropriate model from the fan company's catalogue is selected, and the company's engineers apply design rules to calculate the dimensions and select options and material for the desired performance, strength and operating environment.
Some applications require a dedicated, custom configuration for a fan design to satisfy all specifications.
All industrial fan designs must be accurately engineered to meet performance specifications while maintaining structural integrity. For each application, there are specific flow and pressure requirements. Depending on the application, the fan may be subject to high rotating speeds, an operating environment with corrosive chemicals or abrasive air streams, and extreme temperatures. Larger fans and higher speeds produce greater forces on the rotating structures; for safety and reliability, the design must eliminate excessive stresses and excitable resonant frequencies. Computer modeling programs for computational fluid dynamics (CFD) and finite element analysis (FEA) are often employed in the design process, in addition to laboratory scale model testing. Even after the fan is built the verification might continue, using fan performance testing for flow and pressure, strain gage testing for stresses and tests to record the fan's resonant frequencies.
Fan subtypes
Fan types and their subtypes are industry standard, recognized by all major fan producers.
Centrifugal
Any of these fan subtypes can be built with long-lasting erosion-resistant liners.
Airfoil (Air foil) – Used for a wide range of applications in many industries, fans with hollow, airfoil-profiled blades are designed for use in airstreams where high efficiency and quiet operation are required. They are used extensively for continuous service at ambient and elevated temperatures in forced and induced draft applications in the metals, chemical, power generation, paper, rock products, glass, resource recovery, incineration and other industries throughout the world.
Backward curve – These fans have efficiencies nearly as high as the airfoil design. An advantage is that their single-thickness, curved plate blades prevent the possibility of dust particle buildup inside the blade, as may occur with perforated airfoil blades. The robust design allows high tip-speed operation, and therefore this fan is often used in high-pressure applications.
Backward inclined – These fans have simple flat blades, backwardly inclined to match the velocity pattern of the air passing through the fan wheel for high-efficiency operation. These fans are typically used in high-volume, relatively low-pressure, clean air applications.
Radial blade – The flat blades of this type are arranged in a radial pattern. These rugged fans offer high pressure capability with average efficiency. They are often fitted with erosion-resistant liners to extend rotor life. The housing design is compact to minimize the floor space requirement.
Radial tipped – These fans have wheels that are backward curved, but in a way slightly different from backward curved fans. Backward curved fans have wheels whose blades curve outward, while radial-tip fans' blades are curved inward and radial at their tips (hence the name "radial tip"), while still in a backwardly-curved configuration. Their curvature can also be thought of as radial at the tips but gradually sloping toward the direction of rotation. This rugged design is used in high-volume flow rate applications when the pressure requirement is rather high and erosion resistance is necessary. It offers medium efficiencies. A common application is the dirty side of a baghouse or precipitator. The design is more compact than airfoil, backward curved or backward inclined fans.
Paddle-wheel – This is an open impeller design without shrouds. Although the efficiency is not high, this fan is well suited for applications with extremely high dust loading. It can be offered with field-replaceable blade liners from ceramic tiles or tungsten carbide. This fan may also be used in high-temperature applications.
Forward-curve – This "squirrel cage" impeller generates the highest volume flow rate (for a given tip speed) of all the centrifugal fans. Therefore, it often has the advantage of offering the smallest physical package available for a given application. This type of fan is commonly used in high-temperature furnaces. However, these fans can only be used for conveying air with low dust loading because they are the most sensitive to particle build-up, but also due to the large number of blades that forward-curve wheels require.
Industrial exhausters – This is a relatively inexpensive, medium-duty, steeply inclined flat-bladed fan for exhausting gases, conveying chips, etc.
Pre-engineered fans (PE) – A series of fans of varying blade shapes that are usually available in only standard sizes. Because they are pre-engineered these fans may be available with relatively short delivery times. Often, pre-engineered rotors with various blade shapes may be installed into a common housing. These are often available in a wide range of volume and pressure requirements to meet the needs of many applications.
Pressure blowers – These are high-pressure, low-volume blowers used in combustion air applications in furnaces or to provide “blow-off” air for clearing and/or drying applications.
Surgeless blowers – These high-pressure, low-volume blowers have a reduced tendency for “surging” (periodic variation of flow rate) even at severely reduced fan speeds. This allows extreme turndown (low-flow) without significant pulsation.
Mechanical vapor recovery blowers -These specially designed centrifugal fans are designed to increase temperature and pressure of saturated steam in a closed-loop system.
Acid gas blowers - These very heavy construction blowers are suitable for inlet pressures from full vacuum to 100 psig. Materials are selected for corrosion resistance to the gases and particulate handled.
Specialty process gas blowers - These blowers are for high pressure petrochemical processes.
Axial
High-temperature axial fans – These are high-volume fans designed to operate against low flow resistance in industrial convection furnaces. They may be of either single-direction or bi-directional designs. Extremely rugged, they are most often used in high-temperature furnace (up to 1800 degF) application.
Tube axial fans – These are axial fan units with fan wheels located in cylindrical tubes, without inlet or outlet dampers.
Vaneaxial fans – These axial flow fans have a higher pressure capability due to the presence of static vanes.
Variable pitch axial fans – The blades on these axial fans are manually adjustable to permit the blade angle to be changed. This allows operation over a much wider range of volume/pressure relationships. The blades are adjusted periodically to optimize efficiency by matching the blade pitch to the varying conditions for the application. These fans are often used in mining applications.
Variable pitch on-the-fly axial fans – These are similar to “Variable Pitch Axial Fans” except they include an internal mechanism that allows the blade pitch to be adjusted while the fan rotor is in motion. These versatile fans offer high-efficiency operation at many different points of operation. This instantaneous blade adjustment capability is an advantage that is possible with axial fans only.
Cooling fans - (also referred to as "cooling tower fans") - These are axial fans, typically with large diameters, for low pressures and large volumes of airflow. Applications are in wet mechanical cooling towers, air-cooled steam condensers, air-cooled heat exchangers, radiators, or similar air-cooled applications.
Mixed-flow fans - The gas flow patterns these fans produce resemble a combination of axial and centrifugal patterns, although the fan wheels often appear similar to centrifugal wheels. There are various types of mixed-flow fans, including gas-tight high-pressure fans and blowers.
Jet
Jet Fans are used for daily ventilation requirements and smoke extraction in case of fire (250 ® C/120 min)
These Industrial fans have symmetrical impeller blades; 100% reversible with low noise emissions IP55 motors, insulation class H (smoke extraction version). Application for Basement Ventilation & Tunnel Ventilation etc.
Flow control
There are several means of controlling the flow rate of a fan, e.g., temporarily reducing the air or gas flow rate; these can be applied to both centrifugal and axial fans.
Speed Variation - All of the fan types described above can be used in conjunction with a variable speed driver. This might be an adjustable frequency AC controller, a DC motor and drive, a steam turbine driver, or a hydraulic variable speed drive unit ("fluid drive"). Flow control by means of variable speed is typically smoother and more efficient than by means of damper control. Significant power savings (with reduced cost of operation) are possible if variable speed fan drives are used for applications that require reduced flow operation for a significant portion of the system operating life.
Industrial Dampers - These devices also allow fan volumetric flow control during operation, by means of panels so as to direct gas flow or restrict the inlet or outlet areas.
There is a variety of dampers available:
Louvered Inlet Box Dampers
Radial Inlet Dampers
Variable Inlet Vane (VIV) Dampers
Vortex Dampers
Discharge Dampers
See also
Fan (mechanical)
Axial fan design
Specific fan power
Three-dimensional losses and correlation in turbomachinery
References
External links
Air Movement and Control Association (AMCA)
Online-calculation of axial flow fans: Free basic fan design tool for the calculation of axial flow fan geometry and power curves, cpu-cooling, industry fans, detailed result package available for download
Ventilation fans
Industrial equipment
Turbomachinery | Industrial fan | [
"Chemistry",
"Engineering"
] | 2,609 | [
"Chemical equipment",
"nan",
"Mechanical engineering",
"Turbomachinery"
] |
13,246,451 | https://en.wikipedia.org/wiki/Godwin%20Laboratory%2C%20University%20of%20Cambridge | The Godwin Laboratory is a research facility at the University of Cambridge. It was originally set up to investigate radiocarbon dating and its applications, and was one of the first laboratories to determine a radiocarbon calibration curve. The lab is named after the English scientist Harry Godwin.
History
With the late Professor Sir Nicholas Shackleton in charge, the focus of research shifted to marine isotope records, which document changes in the size of polar ice sheets and temperature changes. This research helped to establish the Milankovitch Theory as the most plausible explanation of glacial/interglacial changes over the past million years, and was continued to develop much more extensive geological timescales, covering the last 30 million years, on the basis of this hypothesis. Other areas researched by members of the laboratory include pollen records and tree rings as a proxy for past climate. The laboratory changed principal allegiance from the Department of Plant Sciences to the Department of Earth Sciences around 1995.
In 2005, after Nick Shackleton's retirement, the laboratory was incorporated into the building housing the Department of Earth Sciences, where it continues to operate. It is part of the inter-departmental Godwin Institute for Quaternary Research, a loose collection of Cambridge University research facilities and workers focused on research particularly addressing the history of the last 1.8 million years.
References
Institutions in the Department of Earth Sciences, University of Cambridge
Geology of the United Kingdom
Radiocarbon dating
Research institutes in Cambridge | Godwin Laboratory, University of Cambridge | [
"Physics",
"Chemistry"
] | 290 | [
"Nuclear chemistry stubs",
"Nuclear and atomic physics stubs",
"Nuclear physics"
] |
13,246,688 | https://en.wikipedia.org/wiki/RDF/XML | RDF/XML is a syntax, defined by the W3C, to express (i.e. serialize) an RDF graph as an XML document. RDF/XML is sometimes misleadingly called simply RDF because it was introduced among the other W3C specifications defining RDF and it was historically the first W3C standard RDF serialization format.
RDF/XML is the primary exchange syntax for OWL 2, and must be supported by all OWL 2 tools.
References
External links
RDF/XML Syntax Specification
RDF Primer
RFC 3870: application/rdf+xml Media Type Registration
Resource Description Framework
Semantic Web
XML-based standards | RDF/XML | [
"Technology"
] | 136 | [
"Computer standards",
"Computer science stubs",
"Computer science",
"XML-based standards",
"Computing stubs"
] |
13,246,733 | https://en.wikipedia.org/wiki/Institute%20for%20Materials%20Research | , abbreviated IMR or , is a research institute for materials science in the Tohoku University, Japan. It consistently ranks as one of the top in ISI citations on materials research. In 2001, it ranked first in the field of materials science by ISI, Philadelphia .
Outline
The institute is the oldest of the five research institutes of Tohoku University. It was started 90 years ago by the late Professor Kotaro Honda for research on KS steel. In 1987, it was reorganized into its present form, a national collaborative research institute, and designated as a Center of Excellence (COE) for materials science.
IMR's research field is diverse materials as well as metals. Some of its recent creations include new types of materials, including high-performance, high-quality and multifunctional materials such as amorphous alloys with complex structures, and bulk metallic glasses developed from them. The institute also specialises in multicomponent intermetallic compounds, quasicrystals, oxides, ceramics, nanostructural controlled metals, semiconductors, crystals for solar cells, biomaterials, organic materials, hydrogen storage alloys, and shaped crystals, among others.
Former names
The present name of the institute is the Institute for Materials Research (IMR).
April 1, 1916: the 2nd Division of the Provisional Institute of Physical and Chemical Research(東北帝国大学理科大学臨時理化学研究所第2部)
May 21, 1919: the Iron and Steel Research Institute (ISRI)(東北帝国大学附属鉄鋼研究所)
August 8, 1922: the Research Institute for Iron, Steel and Other Metals (RIISOM)(東北帝国大学金属材料研究所, 東北大学金属材料研究所1947)
May 21, 1987: Institute for Materials Research (IMR)
Research results
Refer to this page.
People
Presidents
Researchers
Refer to this page.
The institute has produced many world-famous researchers. Akihisa Inoue, the 18th president of Tohoku University, is well-known for his work on bulk metallic glasses. The Institute of Scientific Information (ISI) has named him as one of the most cited researchers in materials science and engineering, with just two of his publications being the 2nd and 8th most highly-cited in the field. Inoue was awarded the 2006 Prime Minister's Prize for this research, and the 2009 James C. McGroddy Prize for New Materials from the American Physical Society.
Facilities and laboratories
Refer to this page.
Address
1-1-2-chome, Katahira, Aoba-ku, Sendai, Miyagi 980-8577 JAPAN
See also
Tohoku University
Research Institute of Electronic Communication
Institute of Development, Aging and Cancer
External links
IMR official website
References
Tohoku University website
Tohoku University
Research institutes in Japan
Materials science institutes
1916 establishments in Japan | Institute for Materials Research | [
"Materials_science"
] | 608 | [
"Materials science organizations",
"Materials science institutes"
] |
13,246,989 | https://en.wikipedia.org/wiki/LifeSaver%20bottle | The LifeSaver bottle is a portable water purification device. The bottle filters out objects larger than 15 nanometres.
Development
After the 2004 Asian tsunami and Hurricane Katrina disaster in the U.S., Michael Pritchard, a water-treatment expert in Ipswich, England began to develop the LifeSaver bottle after seeing that it took multiple days for water to reach refugees. Pritchard presented a prototype of the LifeSaver at 2007's DSEi London, where the product was named "Best Technological Development". Pritchard's entire stock of 1,000 bottles sold out within four hours of the presentation.
Speaking at TED in 2009, Pritchard estimated that by using the LifeSaver bottle, reaching the Millennium Development Goals of halving the number of people without drinking water will cost $8 billion; while $20 billion would provide drinking water for everyone on Earth.
Independent test results
In 2007, the LifeSaver bottle was tested by the London School of Hygiene & Tropical Medicine and the results found it to completely filter out all bacteria and viruses.
Use
The bottle's interchangeable filter can purify between 4,000 and 6,000 litres (1,050 to 1,585 gallons) before it stops working and needs to be replaced. It filters out objects bigger than 15 Nanometres—including viruses, bacteria, and cysts. The carbon filter does not require chemicals. The process of filtering the water takes 20 seconds, allowing for 0.71 litres (1.5 pints) of water to be filtered. Once a filter has reached its limit, it will not allow contaminated water to be drunk. The LiveSaver bottle has been used by soldiers for drinking water as well as cleaning wounds.
To filter the water, one puts contaminated water in the back of the bottle, then screws the lid on. The lid has a built in pump which is operated manually with a hand; the pumping action forces the contaminated water through the nano-filter and safe drinking water collects in another chamber in the bottle. The drinker then opens the top of the bottle from which safe drinking water comes out.
A much larger version of the LifeSaver bottle, called the LifeSaver Jerrycan, has the same filtering technology. The can allows for the filtration of 10,000 to 20,000 litres (2,650 to 5,300 gallons). One jerrycan filter can provide water for four people over a three-year span.
Limits
The bottle can be used to filter urine and will remove all microbiological contamination. However, there will be an amount of dissolved salts that can not be removed. Metals such as iron, and salt from salt water cannot be removed effectively, either.
See also
Tata Swach
Slingshot (water vapor distillation system)
Millbank bag
References
External links
LifeSaver Official Website
Michael Pritchard speaking at TED
Drinking water
Waterborne diseases
Water filters | LifeSaver bottle | [
"Chemistry"
] | 594 | [
"Water treatment",
"Water filters",
"Filters"
] |
13,247,184 | https://en.wikipedia.org/wiki/SMS%20%28hydrology%20software%29 | SMS (Surface-water Modeling System) is a complete program for building and simulating surface water models from Aquaveo. It features 1D and 2D modeling and a unique conceptual model approach. Currently supported models include ADCIRC, CMS-FLOW2D, FESWMS, TABS, TUFLOW, BOUSS-2D, CGWAVE, STWAVE, CMS-WAVE (WABED), GENESIS, PTM, and WAM.
Version 9.2 introduced the use of XMDF (eXtensible Model Data Format), which is a compatible extension of HDF5. XMDF files are smaller and allow faster access times than ASCII files.
The Watershed Modeling System (WMS) is a proprietary water modeling software application used to develop watershed computer simulations. The software provides tools to automate various basic and advanced delineations, calculations, and modeling processes. It supports river hydraulic and storm drain models, lumped parameter, regression, 2D hydrologic modeling of watersheds, and can be used to model both water quantity and water quality. , supported models include HEC-1, HEC-RAS, HEC-HMS, TR-20, TR-55, NFF, Rational, MODRAT, HSPF, CE-QUAL-W2, GSSHA, SMPDBK, and other models.
History
SMS was initially developed by the Engineering Computer Graphics Laboratory at Brigham Young University (later renamed in September, 1998 to Environmental Modeling Research Laboratory or EMRL) in the late 1980s on Unix workstations. The development of SMS was funded primarily by The United States Army Corps of Engineers and is still known as the Department of Defense Surface-water Modeling System or DoD SMS. It was later ported to Windows platforms in the mid 1990s and support for HP-UX, IRIX, OSF/1, and Solaris platforms was discontinued.
In April 2007, the main software development team at EMRL entered private enterprise as Aquaveo LLC, and continue to develop SMS and other software products, such as WMS (Watershed Modeling System) and GMS (Groundwater Modeling System).
WMS was initially developed by the Engineering Computer Graphics Laboratory at Brigham Young University in the early 1990s on Unix workstations. James Nelson, Norman Jones, and Woodruff Miller wrote a 1992 paper titled "Algorithm for Precise Drainage-Basin Delineation" that was published in the March 1994 issue of the Journal of Hydraulic Engineering. The paper described an algorithm that could be used to describe the flow of water in a drainage basin, thereby defining the drainage basin.
The development of WMS was funded primarily by The United States Army Corps of Engineers (COE). In 1997, WMS was used by the COE to model runoff in the Sava River basin in Bosnia. The software was sold commercially by Environmental Modeling Systems.
It was later ported to Windows platforms in the mid 1990s. WMS 6.0 (2000) was the last supported version for HP-UX, IRIX, OSF/1, and Solaris platforms. Development of WMS was done by the Environmental Modeling Research Laboratory (EMRL) at Brigham Young University (BYU) until April 2007, when the main software development team at EMRL incorporated as Aquaveo. Royalties from the software are paid to the engineering department at BYU.
The planners of the 2002 Winter Olympics, held in Salt Lake City, Utah, used WMS software to simulate terrorist attacks on water infrastructure such as the Jordanelle Reservoir.
Examples of SMS Implementation
SMS modeling was used to "determine flooded areas in case of failure or revision of a weir in combination with a coincidental 100-year flood event" (Gerstner, Belzner, and Thorenz, p. 975). Furthermore, "concerning the water level calculations in case of failure of a weir, the provided the with those two-dimensional depth-averaged hydrodynamic models, which are covering the whole Bavarian part of the river Main. The models were created with the software Surface-Modeling System (SMS) of Aquaveo LLC" (Gerstner, Belzner, and Thorenz, 976).
This article "describes the mathematical formulation, numerical implementation, and input specifications of rubble mound structures in the Coastal Modeling System (CMS) operated through the Surface-water Modeling System (SMS)" (Li et al., 1). Describing the input specifications, the authors write, "Working with the SMS interface, users can specify rubble mound structures in the CMS by creating datasets for different structure parameters. Five datasets are required for this application" (Li et al., p. 3) and "users should refer to Aquaveo (2010) for generating a XMDF dataset (*.h5 file) under the SMS" (Li et al., p. 5).
This study examined the "need of developing mathematical models for determining and predicting water quality of 'river-type' systems. It presents a case study for determining the pollutant dispersion for a section of the River Prut, Ungheni town, which was filled with polluted water with oil products from its tributary river Delia" (Marusic and Ciufudean, p. 177). "The obtained numerical models were developed using the program Surface-water Modeling System (SMS) v.10.1.11, which was designed by experts from Aquaveo company. The hydrodynamics of the studied sector, obtained using the SMS module named RMA2 [13], served as input for the RMA module 4, which determined the pollutant dispersion" (Marusic and Ciufudean, p. 178–179).
This study focused on finding "recommendations for optimization" of the "Chusovskoy water intake located in the confluence zone of two rivers with essentially different hydrochemical regimes and in the backwater zone of the " (Lyubimova et al., p. 1). "A two-dimensional (in a horizontal plane) model for the examined region of the water storage basin was constructed by making use of the software product SMS v.10 of the American company AQUAVEO LLC" (Lyubimova et al., p. 2). Evaluations of the SMS-derived, two-dimensional model as well as a three-dimensional model yielded the discovery that "the selective water intake from the near-surface layers can essentially reduce hardness of potable water consumed by the inhabitants of Perm" (Lyubimova et al., p. 6).
References
External links
US Army Corps of Engineers – DoD SMS white paper
SMS Documentation Wiki
Scientific simulation software
Hydrology software | SMS (hydrology software) | [
"Environmental_science"
] | 1,379 | [
"Hydrology",
"Hydrology software"
] |
13,247,256 | https://en.wikipedia.org/wiki/Nuclebr%C3%A1s%20Equipamentos%20Pesados | The Nuclebrás Equipamentos Pesados S.A., commonly shortned to NUCLEP, is a Brazilian state-owned nuclear company specialized in nuclear engineering and heavy equipment for nuclear, defense, oil and gas industries, founded on 12 April 1975.
See also
Goiânia accident (Nuclebrás aided in response effort)
National Nuclear Energy Commission
References
Manufacturing companies of Brazil
Companies based in Rio de Janeiro (state)
Manufacturing companies established in 1975
Engineering companies of Brazil
Defence companies of Brazil
Nuclear technology companies of Brazil
Brazilian companies established in 1975 | Nuclebrás Equipamentos Pesados | [
"Physics"
] | 116 | [
"Nuclear and atomic physics stubs",
"Nuclear physics"
] |
13,247,267 | https://en.wikipedia.org/wiki/Lyndon%E2%80%93Hochschild%E2%80%93Serre%20spectral%20sequence | In mathematics, especially in the fields of group cohomology, homological algebra and number theory, the Lyndon spectral sequence or Hochschild–Serre spectral sequence is a spectral sequence relating the group cohomology of a normal subgroup N and the quotient group G/N to the cohomology of the total group G. The spectral sequence is named after Roger Lyndon, Gerhard Hochschild, and Jean-Pierre Serre.
Statement
Let be a group and be a normal subgroup. The latter ensures that the quotient is a group, as well. Finally, let be a -module. Then there is a spectral sequence of cohomological type
and there is a spectral sequence of homological type
,
where the arrow '' means convergence of spectral sequences.
The same statement holds if is a profinite group, is a closed normal subgroup and denotes the continuous cohomology.
Examples
Homology of the Heisenberg group
The spectral sequence can be used to compute the homology of the Heisenberg group G with integral entries, i.e., matrices of the form
This group is a central extension
with center corresponding to the subgroup with . The spectral sequence for the group homology, together with the analysis of a differential in this spectral sequence, shows that
Cohomology of wreath products
For a group G, the wreath product is an extension
The resulting spectral sequence of group cohomology with coefficients in a field k,
is known to degenerate at the -page.
Properties
The associated five-term exact sequence is the usual inflation-restriction exact sequence:
Generalizations
The spectral sequence is an instance of the more general Grothendieck spectral sequence of the composition of two derived functors. Indeed, is the derived functor of (i.e., taking G-invariants) and the composition of the functors and is exactly .
A similar spectral sequence exists for group homology, as opposed to group cohomology, as well.
References
(paywalled)
Spectral sequences
Group theory | Lyndon–Hochschild–Serre spectral sequence | [
"Mathematics"
] | 411 | [
"Group theory",
"Fields of abstract algebra"
] |
13,247,379 | https://en.wikipedia.org/wiki/Factorion | In number theory, a factorion in a given number base is a natural number that equals the sum of the factorials of its digits. The name factorion was coined by the author Clifford A. Pickover.
Definition
Let be a natural number. For a base , we define the sum of the factorials of the digits of , , to be the following:
where is the number of digits in the number in base , is the factorial of and
is the value of the th digit of the number. A natural number is a -factorion if it is a fixed point for , i.e. if . and are fixed points for all bases , and thus are trivial factorions for all , and all other factorions are nontrivial factorions.
For example, the number 145 in base is a factorion because .
For , the sum of the factorials of the digits is simply the number of digits in the base 2 representation since .
A natural number is a sociable factorion if it is a periodic point for , where for a positive integer , and forms a cycle of period . A factorion is a sociable factorion with , and a amicable factorion is a sociable factorion with .
All natural numbers are preperiodic points for , regardless of the base. This is because all natural numbers of base with digits satisfy . However, when , then for , so any will satisfy until . There are finitely many natural numbers less than , so the number is guaranteed to reach a periodic point or a fixed point less than , making it a preperiodic point. For , the number of digits for any number, once again, making it a preperiodic point. This means also that there are a finite number of factorions and cycles for any given base .
The number of iterations needed for to reach a fixed point is the function's persistence of , and undefined if it never reaches a fixed point.
Factorions for
b = (k − 1)!
Let be a positive integer and the number base . Then:
is a factorion for for all
is a factorion for for all .
b = k! − k + 1
Let be a positive integer and the number base . Then:
is a factorion for for all .
Table of factorions and cycles of
All numbers are represented in base .
See also
Arithmetic dynamics
Dudeney number
Happy number
Kaprekar's constant
Kaprekar number
Meertens number
Narcissistic number
Perfect digit-to-digit invariant
Perfect digital invariant
Sum-product number
References
External links
Factorion at Wolfram MathWorld
Arithmetic dynamics
Base-dependent integer sequences | Factorion | [
"Mathematics"
] | 536 | [
"Recreational mathematics",
"Number theory",
"Arithmetic dynamics",
"Dynamical systems"
] |
13,248,239 | https://en.wikipedia.org/wiki/Composition%20of%20the%20human%20body | Body composition may be analyzed in various ways. This can be done in terms of the chemical elements present, or by molecular structure e.g., water, protein, fats (or lipids), hydroxyapatite (in bones), carbohydrates (such as glycogen and glucose) and DNA. In terms of tissue type, the body may be analyzed into water, fat, connective tissue, muscle, bone, etc. In terms of cell type, the body contains hundreds of different types of cells, but notably, the largest number of cells contained in a human body (though not the largest mass of cells) are not human cells, but bacteria residing in the normal human gastrointestinal tract.
Elements
About 99% of the mass of the human body is made up of six elements: oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus. Only about 0.85% is composed of another five elements: potassium, sulfur, sodium, chlorine, and magnesium. All 11 are necessary for life. The remaining elements are trace elements, of which more than a dozen are thought on the basis of good evidence to be necessary for life. All of the mass of the trace elements put together (less than 10 grams for a human body) do not add up to the body mass of magnesium, the least common of the 11 non-trace elements.
Other elements
Not all elements which are found in the human body in trace quantities play a role in life. Some of these elements are thought to be simple common contaminants without function (examples: caesium, titanium), while many others are thought to be active toxins, depending on amount (cadmium, mercury, lead, radioactives). In humans, arsenic is toxic, and its levels in foods and dietary supplements are closely monitored to reduce or eliminate its intake.
Some elements (silicon, boron, nickel, vanadium) are probably needed by mammals also, but in far smaller doses. Bromine is used by some (though not all) bacteria, fungi, diatoms, and seaweeds, and opportunistically in eosinophils in humans. One study has indicated bromine to be necessary to collagen IV synthesis in humans. Fluorine is used by a number of plants to manufacture toxins but in humans its only known function is as a local topical hardening agent in tooth enamel.
Elemental composition list
The average adult human body contains approximately atoms and contains at least detectable traces of 60 chemical elements. About 29 of these elements are thought to play an active positive role in life and health in humans.
The relative amounts of each element vary by individual, mainly due to differences in the proportion of fat, muscle and bone in their body. Persons with more fat will have a higher proportion of carbon and a lower proportion of most other elements (the proportion of hydrogen will be about the same).
The numbers in the table are averages of different numbers reported by different references.
The adult human body averages ~53% water. This varies substantially by age, sex, and adiposity. In a large sample of adults of all ages and both sexes, the figure for water fraction by weight was found to be 48 ±6% for females and 58 ±8% water for males. Water is ~11% hydrogen by mass but ~67% hydrogen by atomic percent, and these numbers along with the complementary % numbers for oxygen in water, are the largest contributors to overall mass and atomic composition figures. Because of water content, the human body contains more oxygen by mass than any other element, but more hydrogen by atom-fraction than any element.
The elements listed below as "Essential in humans" are those listed by the US Food and Drug Administration as essential nutrients, as well as six additional elements: oxygen, carbon, hydrogen, and nitrogen (the fundamental building blocks of life on Earth), sulfur (essential to all cells) and cobalt (a necessary component of vitamin B12). Elements listed as "Possibly" or "Probably" essential are those cited by the US National Research Council as beneficial to human health and possibly or probably essential.
*Iron = ~3 g in males, ~2.3 g in females
Of the 94 naturally occurring chemical elements, 76 are listed in the table above. Of the remaining 18, it is not known how many occur in the human body.
Most of the elements needed for life are relatively common in the Earth's crust. Aluminium, the third most common element in the Earth's crust (after oxygen and silicon), serves no function in living cells, but is toxic in large amounts, depending on its physical and chemical forms and magnitude, duration, frequency of exposure, and how it was absorbed by the human body. Transferrins can bind aluminium.
Periodic table
Composition
The composition of the human body can be classified as follows:
Water
Proteins
Fats (or lipids)
Hydroxyapatite in bones
Carbohydrates such as glycogen and glucose
DNA and RNA
Inorganic ions such as sodium, potassium, chloride, bicarbonate, phosphate
Gases mainly being oxygen, carbon dioxide
Many cofactors.
The estimated contents of a typical 20-micrometre human cell is as follows:
Tissues
Body composition can also be expressed in terms of various types of material, such as:
Muscle
Fat
Bone and teeth
Nervous tissue (brain and nerves)
Hormones
Connective tissue
Body fluids (blood, lymph, urine)
Contents of digestive tract, including intestinal gas
Air in lungs
Epithelium
Composition by cell type
There are many species of bacteria and other microorganisms that live on or inside the healthy human body. In fact, there are roughly as many microbial as human cells in the human body by number.
(much less by mass or volume). Some of these symbionts are necessary for our health. Those that neither help nor harm humans are called commensal organisms.
See also
List of organs of the human body
Hydrostatic weighing
Dietary element
Composition of blood
List of human blood components
Body composition
Abundance of elements in Earth's crust
Abundance of the chemical elements
References
Biochemistry
Human anatomy
Human physiology | Composition of the human body | [
"Chemistry",
"Biology"
] | 1,261 | [
"Biochemistry",
"nan"
] |
13,248,494 | https://en.wikipedia.org/wiki/Tropospheric%20ozone%20depletion%20events | Tropospheric ozone depletion events are phenomena that reduce the concentration of ozone in the earth's troposphere. Ozone (O3) is a trace gas which has been of concern because of its unique dual role in different layers of the lower atmosphere. Apart from absorbing UV-B radiation and converting solar energy into heat in the stratosphere, ozone in the troposphere provides greenhouse effect and controls the oxidation capacity of the atmosphere.
Sources of tropospheric ozone
Ozone in the troposhere is determined by photochemical production and destruction, dry deposition and cross-tropopause transport of ozone from the stratosphere. In the Arctic troposphere, transport and photochemical reactions involving nitrogen oxides and volatile organic compounds (VOCs) as a result of human emissions also produce ozone resulting in a background mixing ratio of 30 to 50 nmol mol−1 (ppb). Nitrogen oxides play a key role in recycling active free radicals (such as reactive halogens) in the atmosphere and indirectly affect ozone depletion. Ozone depletion events (ODEs) are phenomena associated with the sea ice zone. They are routinely observed at coastal locations when incoming winds have traversed sea ice covered areas.
Halogen activation
During springtime in the polar regions of Earth, unique photochemistry converts inert halide salt ions (e.g. Br−) into reactive halogen species (e.g. Br atoms and BrO) that episodically deplete ozone in the atmospheric boundary layer to near zero levels. These processes are favored by light and low temperature conditions. Since their discovery in the late 1980s, research on these ozone depletion events has shown the central role of
bromine photochemistry. The exact sources and mechanisms that release bromine are still not fully understood, but the combination of concentrated sea salt in a condensed phase substrate appears to be a pre-requisite. Shallow boundary layers are also likely to be beneficial since they enhance the speed of autocatalytic bromine release by confining the released bromine to a smaller space. Under these conditions, and with sufficient acidity, gaseous hypobromous acid (HOBr) can react with condensed sea salt bromide and produce bromine that is then released to the atmosphere. Subsequent photolysis of this bromine generates bromine radicals that can react with and destroy ozone. Due to the autocatalytic nature of the reaction mechanism, it has been called bromine explosion.
Chemical destruction
It is still not fully understood how salts are transported from the ocean and oxidized to become reactive halogen species in the air. Other halogens (chlorine and iodine) are also activated through mechanisms coupled to bromine chemistry. The main consequence of halogen activation is chemical destruction of ozone, which removes the primary precursor of atmospheric oxidation, and generation of reactive halogen atoms/oxides that become the primary oxidizing species. The oxidation ability originally influenced by ozone is weakened, while the halogen species now holds the oxidation ability. This changes the reaction cycles and final products of many atmospheric reactions. During ozone depletion events, the enhanced halogen chemistry can effectively oxidize reactive gaseous elements.
Effects
The different reactivity of halogens as compared to OH and ozone has broad impacts on atmospheric chemistry. These include near complete removal and deposition of mercury, alteration of oxidation fates for organic gases, and export of bromine into the free troposphere. The deposition of reactive gaseous mercury (RGM) in snow from oxidation by enhanced halogens increases the bioavailability of mercury. Recent changes in the climate of the Arctic and state of the Arctic sea ice cover are likely to have strong effects on halogen activation and ozone depletion events. Human-induced climate change affects the quantity of snow and ice cover in the Arctic, altering the intensity of nitrogen oxide emissions. Increment in background levels of nitrogen oxide apparently strengthens the consumption of ozone and the enhancement of halogens.
See also
Arctic haze
Free radical halogenation
Tropospheric ozone
Frost flower (sea ice)
References
Environmental chemistry
Ozone depletion | Tropospheric ozone depletion events | [
"Chemistry",
"Environmental_science"
] | 848 | [
"Environmental chemistry",
"nan"
] |
13,250,030 | https://en.wikipedia.org/wiki/Angel%20Balevski | Angel Balevski () (4 March 1910 – 15 September 1997) was a Bulgarian engineer, inventor, and politician. He has been a member of the State Council of the People's Republic of Bulgaria for the whole duration of its existence (1971-1989). Balevski was president of the Bulgarian Academy of Sciences (1968-1988), Co-president of the International Academy of Science, Munich (1988-1997) and chairman of the Bulgarian Pugwash Group.
Life
He graduated from a technical school in Brno in the Czech Republic in 1934 and started his professional career as a metallurgical engineer. Later he was a professor at numerous universities across Europe. Balevski was the founder of the Bulgarian academic school in the field of metal sciences and technologies. He was successful in designing a hot pressing machine for non-ferrous metals. He developed an original method for cast iron production from Bulgarian raw materials in a rotating drum furnace. Together with Ivan Dimov, he developed a counter-pressure casting method which was a novelty in world foundry technology and was protected by over 100 patent documents in Bulgaria and abroad. He was the author or co-author of more than seven monographs and academic textbooks.
Awards
Balevski was elected honorary and foreign member of the academies and research societies in many countries. He was the Co-president of the International Academy of Science, Munich (1988) and a member of the Board of the Pugwash Movement of Scientists for Peace (1971).
He was presented with the highest Bulgarian and foreign awards for his contribution to science and inventions, including two Dimitrov Prizes, the French Palmes académiques, the Lomonosov Gold Medal of the Russian Academy of Sciences and others. He was also awarded the honorary title of People's Scientist. He was Doctor h.c. of the Technical University, Sofia.
References
See also
Bulgarian Academy of Science
International Academy of Science (History)
1910 births
1997 deaths
People from Troyan
Bulgarian inventors
Members of the Bulgarian Academy of Sciences
Foreign members of the USSR Academy of Sciences
Foreign members of the Russian Academy of Sciences
Recipients of the Ordre des Palmes Académiques
Recipients of the Lomonosov Gold Medal
Bulgarian mechanical engineers
Technical University, Sofia
20th-century inventors | Angel Balevski | [
"Technology"
] | 463 | [
"Science and technology awards",
"Recipients of the Lomonosov Gold Medal"
] |
13,250,438 | https://en.wikipedia.org/wiki/Protein%20mass%20spectrometry | Protein mass spectrometry refers to the application of mass spectrometry to the study of proteins. Mass spectrometry is an important method for the accurate mass determination and characterization of proteins, and a variety of methods and instrumentations have been developed for its many uses. Its applications include the identification of proteins and their post-translational modifications, the elucidation of protein complexes, their subunits and functional interactions, as well as the global measurement of proteins in proteomics. It can also be used to localize proteins to the various organelles, and determine the interactions between different proteins as well as with membrane lipids.
The two primary methods used for the ionization of protein in mass spectrometry are electrospray ionization (ESI) and matrix-assisted laser desorption/ionization (MALDI). These ionization techniques are used in conjunction with mass analyzers such as tandem mass spectrometry. In general, the proteins are analyzed either in a "top-down" approach in which proteins are analyzed intact, or a "bottom-up" approach in which protein are first digested into fragments. An intermediate "middle-down" approach in which larger peptide fragments are analyzed may also sometimes be used.
History
The application of mass spectrometry to study proteins became popularized in the 1980s after the development of MALDI and ESI. These ionization techniques have played a significant role in the characterization of proteins. (MALDI) Matrix-assisted laser desorption ionization was coined in the late 1980s by Franz Hillenkamp and Michael Karas. Hillenkamp, Karas and their fellow researchers were able to ionize the amino acid alanine by mixing it with the amino acid tryptophan and irradiated with a pulse 266 nm laser. Though important, the breakthrough did not come until 1987. In 1987, Koichi Tanaka used the "ultra fine metal plus liquid matrix method" and ionized biomolecules the size of 34,472 Da protein carboxypeptidase-A.
In 1968, Malcolm Dole reported the first use of electrospray ionization with mass spectrometry. Around the same time MALDI became popularized, John Bennett Fenn was cited for the development of electrospray ionization. Koichi Tanaka received the 2002 Nobel Prize in Chemistry alongside John Fenn, and Kurt Wüthrich "for the development of methods for identification and structure analyses of biological macromolecules." These ionization methods have greatly facilitated the study of proteins by mass spectrometry. Consequently, protein mass spectrometry now plays a leading role in protein characterization.
Methods and approaches
Techniques
Mass spectrometry of proteins requires that the proteins in solution or solid state be turned into an ionized form in the gas phase before they are injected and accelerated in an electric or magnetic field for analysis. The two primary methods for ionization of proteins are electrospray ionization (ESI) and matrix-assisted laser desorption/ionization (MALDI). In electrospray, the ions are created from proteins in solution, and it allows fragile molecules to be ionized intact, sometimes preserving non-covalent interactions. In MALDI, the proteins are embedded within a matrix normally in a solid form, and ions are created by pulses of laser light. Electrospray produces more multiply-charged ions than MALDI, allowing for measurement of high mass protein and better fragmentation for identification, while MALDI is fast and less likely to be affected by contaminants, buffers and additives.
Whole-protein mass analysis is primarily conducted using either time-of-flight (TOF) MS, or Fourier transform ion cyclotron resonance (FT-ICR). These two types of instrument are preferable here because of their wide mass range, and in the case of FT-ICR, its high mass accuracy. Electrospray ionization of a protein often results in generation of multiple charged species of 800 < m/z < 2000 and the resultant spectrum can be deconvoluted to determine the protein's average mass to within 50 ppm or better using TOF or ion-trap instruments.
Mass analysis of proteolytic peptides is a popular method of protein characterization, as cheaper instrument designs can be used for characterization. Additionally, sample preparation is easier once whole proteins have been digested into smaller peptide fragments. The most widely used instrument for peptide mass analysis are the MALDI-TOF instruments as they permit the acquisition of peptide mass fingerprints (PMFs) at high pace (1 PMF can be analyzed in approx. 10 sec). Multiple stage quadrupole-time-of-flight and the quadrupole ion trap also find use in this application.
Tandem mass spectrometry (MS/MS) is used to measure fragmentation spectra and identify proteins at high speed and accuracy. Collision-induced dissociation is used in mainstream applications to generate a set of fragments from a specific peptide ion. The fragmentation process primarily gives rise to cleavage products that break along peptide bonds. Because of this simplicity in fragmentation, it is possible to use the observed fragment masses to match with a database of predicted masses for one of many given peptide sequences. Tandem MS of whole protein ions has been investigated recently using electron capture dissociation and has demonstrated extensive sequence information in principle but is not in common practice.
Approaches
In keeping with the performance and mass range of available mass spectrometers, two approaches are used for characterizing proteins. In the first, intact proteins are ionized by either of the two techniques described above, and then introduced to a mass analyzer. This approach is referred to as "top-down" strategy of protein analysis as it involves starting with the whole mass and then pulling it apart. The top-down approach however is mostly limited to low-throughput single-protein studies due to issues involved in handling whole proteins, their heterogeneity and the complexity of their analyses.
In the second approach, referred to as the "bottom-up" MS, proteins are enzymatically digested into smaller peptides using a protease such as trypsin. Subsequently, these peptides are introduced into the mass spectrometer and identified by peptide mass fingerprinting or tandem mass spectrometry. Hence, this approach uses identification at the peptide level to infer the existence of proteins pieced back together with de novo repeat detection. The smaller and more uniform fragments are easier to analyze than intact proteins and can be also determined with high accuracy, this "bottom-up" approach is therefore the preferred method of studies in proteomics. A further approach that is beginning to be useful is the intermediate "middle-down" approach in which proteolytic peptides larger than the typical tryptic peptides are analyzed.
Protein and peptide fractionation
Proteins of interest are usually part of a complex mixture of multiple proteins and molecules, which co-exist in the biological medium. This presents two significant problems. First, the two ionization techniques used for large molecules only work well when the mixture contains roughly equal amounts of material, while in biological samples, different proteins tend to be present in widely differing amounts. If such a mixture is ionized using electrospray or MALDI, the more abundant species have a tendency to "drown" or suppress signals from less abundant ones. Second, mass spectrum from a complex mixture is very difficult to interpret due to the overwhelming number of mixture components. This is exacerbated by the fact that enzymatic digestion of a protein gives rise to a large number of peptide products.
In light of these problems, the methods of one- and two-dimensional gel electrophoresis and high performance liquid chromatography are widely used for separation of proteins. The first method fractionates whole proteins via two-dimensional gel electrophoresis. The first-dimension of 2D gel is isoelectric focusing (IEF). In this dimension, the protein is separated by its isoelectric point (pI) and the second-dimension is SDS-polyacrylamide gel electrophoresis (SDS-PAGE). This dimension separates the protein according to its molecular weight. Once this step is completed in-gel digestion occurs. In some situations, it may be necessary to combine both of these techniques. Gel spots identified on a 2D Gel are usually attributable to one protein. If the identity of the protein is desired, usually the method of in-gel digestion is applied, where the protein spot of interest is excised, and digested proteolytically. The peptide masses resulting from the digestion can be determined by mass spectrometry using peptide mass fingerprinting. If this information does not allow unequivocal identification of the protein, its peptides can be subject to tandem mass spectrometry for de novo sequencing. Small changes in mass and charge can be detected with 2D-PAGE. The disadvantages with this technique are its small dynamic range compared to other methods, some proteins are still difficult to separate due to their acidity, basicity, hydrophobicity, and size (too large or too small).
The second method, high performance liquid chromatography is used to fractionate peptides after enzymatic digestion. Characterization of protein mixtures using HPLC/MS is also called shotgun proteomics and MuDPIT (Multi-Dimensional Protein Identification Technology). A peptide mixture that results from digestion of a protein mixture is fractionated by one or two steps of liquid chromatography. The eluent from the chromatography stage can be either directly introduced to the mass spectrometer through electrospray ionization, or laid down on a series of small spots for later mass analysis using MALDI.
Applications
Protein identification
There are two main ways MS is used to identify proteins. Peptide mass fingerprinting uses the masses of proteolytic peptides as input to a search of a database of predicted masses that would arise from digestion of a list of known proteins. If a protein sequence in the reference list gives rise to a significant number of predicted masses that match the experimental values, there is some evidence that this protein was present in the original sample. Purification steps therefore limit the throughput of the peptide mass fingerprinting approach. Alternatively, peptides can be fragmented with MS/MS to more definitively identify them.
MS is also the preferred method for the identification of post-translational modifications in proteins versus other approaches such as antibody-based methods.
De novo (peptide) sequencing
De novo peptide sequencing for mass spectrometry is typically performed without prior knowledge of the amino acid sequence. It is the process of assigning amino acids from peptide fragment masses of a protein. De novo sequencing has proven successful for confirming and expanding upon results from database searches.
As de novo sequencing is based on mass and some amino acids have identical masses (e.g. leucine and isoleucine), accurate manual sequencing can be difficult. Therefore, it may be necessary to utilize a sequence homology search application to work in tandem between a database search and de novo sequencing to address this inherent limitation.
Database searching has the advantage of quickly identifying sequences, provided they have already been documented in a database. Other inherent limitations of database searching include sequence modifications/mutations (some database searches do not adequately account for alterations to the 'documented' sequence, thus can miss valuable information), the unknown (if a sequence is not documented, it will not be found), false positives, and incomplete and corrupted data.
An annotated peptide spectral library can also be used as a reference for protein/peptide identification. It offers the unique strength of reduced search space and increased specificity. The limitations include spectra not included in the library will not be identified, spectra collected from different types of mass spectrometers can have quite distinct features, and reference spectra in the library may contain noise peaks, which may lead to false positive identifications. A number of different algorithmic approaches have been described to identify peptides and proteins from tandem mass spectrometry (MS/MS), peptide de novo sequencing and sequence tag-based searching.
Antigen presentation
Antigen presentation is the first step in educating the immune system to recognize new pathogens. To this end, antigen presenting cells expose protein fragments via MHC molecules to the immune system. Not all protein fragments bind, however, to the MHC molecules of a certain individual. Using mass spectrometry, the true spectrum of molecules presented to the immune system can be determined.
Protein quantitation
Multiple methods allow for the quantitation of proteins by mass spectrometry, and recent advances have enabled quantifying thousands of proteins in single cells. Protein quantification by mass spectrometry benefits from efficient sampling (counting) of many ions per protein compared to other methods. Quantifications can be performed by label-free methods and by multiplexed methods, which use isotopic mass tags as labels. Multiplexed methods can improve both quantitative accuracy and throughput.
Typically, stable (e.g. non-radioactive) heavier isotopes of carbon (13C) or nitrogen (15N) are incorporated into one sample while the other one is labeled with corresponding light isotopes (e.g. 12C and 14N). The two samples are mixed before the analysis. Peptides derived from the different samples can be distinguished due to their mass difference. The ratio of their peak intensities corresponds to the relative abundance ratio of the peptides (and proteins). The first generation of methods for isotope labeling included SILAC (stable isotope labeling by amino acids in cell culture), trypsin-catalyzed 18O labeling, ICAT (isotope coded affinity tagging), and iTRAQ (isobaric tags for relative and absolute quantitation). The more recent generation of multiplexing methods include tandem mass tags (TMT) for DDA data and mTRAQ for multiplexed DIA (plexDIA).
"Semi-quantitative" mass spectrometry can be performed without labeling of samples. Typically, this is done with MALDI analysis (in linear mode). The peak intensity, or the peak area, from individual molecules (typically proteins) is here correlated to the amount of protein in the sample. However, the individual signal depends on the primary structure of the protein, on the complexity of the sample, and on the settings of the instrument. Other types of "label-free" quantitative mass spectrometry, uses the spectral counts (or peptide counts) of digested proteins as a means for determining relative protein amounts.
Protein structure determination
Characteristics indicative of the 3-dimensional structure of proteins can be probed with mass spectrometry in various ways. Comparing charge state distributions can give information about the structure of a protein. A wide variety of high charge states indicates disorder of the protein, whereas more compact, folded proteins result in lower charge states. By using chemical crosslinking to couple parts of the protein that are close in space, but far apart in sequence, information about the overall structure can be inferred. By following the exchange of amide protons with deuterium from the solvent, it is possible to probe the solvent accessibility of various parts of the protein. Hydrogen-deuterium exchange mass spectrometry has been used to study proteins and their conformations for over 20 years. This type of protein structural analysis can be suitable for proteins that are challenging for other structural methods. Another interesting avenue in protein structural studies is laser-induced covalent labeling. In this technique, solvent-exposed sites of the protein are modified by hydroxyl radicals. Its combination with rapid mixing has been used in protein folding studies.
Proteogenomics
In what is now commonly referred to as proteogenomics, peptides identified with mass spectrometry are used for improving gene annotations (for example, gene start sites) and protein annotations. Parallel analysis of the genome and the proteome facilitates discovery of post-translational modifications and proteolytic events, especially when comparing multiple species.
References
Mass spectrometry
Proteomics | Protein mass spectrometry | [
"Physics",
"Chemistry"
] | 3,330 | [
"Spectrum (physical sciences)",
"Instrumental analysis",
"Mass",
"Mass spectrometry",
"Matter"
] |
13,250,641 | https://en.wikipedia.org/wiki/Tutte%E2%80%93Berge%20formula | In the mathematical discipline of graph theory the Tutte–Berge formula is a characterization of the size of a maximum matching in a graph. It is a generalization of Tutte theorem on perfect matchings, and is named after W. T. Tutte (who proved Tutte's theorem) and Claude Berge (who proved its generalization).
Statement
The theorem states that the size of a maximum matching of a graph equals
where counts how many of the connected components of the graph have an odd number of vertices.
Equivalently, the number of unmatched vertices in a maximum matching equals.
Explanation
Intuitively, for any subset of the vertices, the only way to completely cover an odd component of by a matching is for one of the matched edges covering the component to be incident to . If, instead, some odd component had no matched edge connecting it to , then the part of the matching that covered the component would cover its vertices in pairs, but since the component has an odd number of vertices it would necessarily include at least one leftover and unmatched vertex. Therefore, if some choice of has few vertices but its removal creates a large number of odd components, then there will be many unmatched vertices, implying that the matching itself will be small. This reasoning can be made precise by stating that the size of a maximum matching is at most equal to the value given by the Tutte–Berge formula.
The characterization of Tutte and Berge proves that this is the only obstacle to creating a large matching: the size of the optimal matching will be determined by the subset with the biggest difference between its numbers of odd components outside and vertices inside . That is, there always exists a subset such that deleting creates the correct number of odd components needed to make the formula true. One way to find such a set is to choose any maximum matching , and to let be the set of vertices that are either unmatched in , or that can be reached from an unmatched vertex by an alternating path that ends with a matched edge. Then, let be the set of vertices that are matched by to vertices in . No two vertices in can be adjacent, for if they were then their alternating paths could be concatenated to give a path by which the matching could be increased, contradicting the maximality of . Every neighbor of a vertex in must belong to , for otherwise we could extend an alternating path to by one more pair of edges, through the neighbor, causing the neighbor to become part of . Therefore, in , every vertex of forms a single-vertex component, which is odd. There can be no other odd components, because all other vertices remain matched after deleting . So with this construction the size of and the number of odd components created by deleting are what they need to be to make the formula be true.
Relation to Tutte's theorem
Tutte's theorem characterizes the graphs with perfect matchings as being the ones for which deleting any subset of vertices creates at most odd components. (A subset that creates at least odd components can always be found in the empty set.) In this case, by the Tutte–Berge formula, the size of the matching is ; that is, the maximum matching is a perfect matching. Thus, Tutte's theorem can be derived as a corollary of the Tutte–Berge formula, and the formula can be seen as a generalization of Tutte's theorem.
See also
Graph toughness, a problem of creating many connected components by removing a small set of vertices without regard to the parity of the components
Hall's marriage theorem
References
Reprinted by Dover Publications, 2001.
Matching (graph theory)
Theorems in discrete mathematics | Tutte–Berge formula | [
"Mathematics"
] | 763 | [
"Mathematical theorems",
"Discrete mathematics",
"Graph theory",
"Theorems in discrete mathematics",
"Mathematical relations",
"Matching (graph theory)",
"Mathematical problems"
] |
13,250,817 | https://en.wikipedia.org/wiki/Zip%20fuel | Zip fuel, also known as high energy fuel (HEF), is any member of a family of jet fuels containing additives in the form of hydro-boron compounds, or boranes. Zip fuels offer higher energy density than conventional fuels, helping extend the range of jet aircraft. In the 1950s, when the short range of jet aircraft was a major problem for military planners, zip fuels were a topic of significant study.
A number of aircraft were designed to make use of zip, including the XB-70 Valkyrie, XF-108 Rapier, as well as the BOMARC, and even the nuclear-powered aircraft program. The Navy considered converting all of their jet engines to zip and began studies of converting their aircraft carriers to safely store it.
In testing, the fuels proved to have several serious problems, and the entire effort was eventually cancelled in 1959.
Description
The highest energy-density fuel (by weight) in common propellant combinations is hydrogen. However, gaseous hydrogen has very low (volume) density; liquified hydrogen has higher density but is complex and expensive to store. When combined with carbon, hydrogen can be rendered into the easily burnable hydrocarbon fuels. Other elements, like aluminum and beryllium, have even higher energy content than carbon, but do not mix well to form a stable fuel that can be easily burned.
Of all the low-mass elements, boron has the combination of high energy, low weight and wide availability that makes it interesting as a potential fuel. Boranes have a high specific energy, about 70,000 kJ/kg (30,000 BTU/lb). This compares favorably to a typical kerosene-based fuel, such as JP-4 or RP-1, which provides about 42,000 kJ/kg (18,000 BTU/lb). They are not suitable for burning as a fuel on their own, however, as they are often prone to self-ignition in contact with air, making them dangerous to handle.
When mixed with conventional jet fuels, they add to the energy content while becoming somewhat more stable. In general terms, boron-enhanced fuels offer up to 40% higher energy density than plain JP-4 in terms of both weight and volume. In the US a whole family of fuels were investigated, and generally referred to by the names they were assigned during the Air Force's Project HEF: HEF-1 (ethyldiborane), HEF-2 (propylpentaborane), HEF-3 (ethyldecaborane), HEF-4 (methyldecaborane), and HEF-5 (ethylacetylenedecaborane).
Zip fuels have a number of disadvantages. For one, the fuel is toxic, as is its exhaust. This was of little concern in flight, but a major concern for ground crews servicing the aircraft. The fuels burn to create solids that are both sticky and corrosive, while boron carbide solids are abrasive. This caused serious problems for turbine blades in jet engines, where the exhaust built up on the blades and reduced their effectiveness and sometimes caused catastrophic failure of the engine. Finally, the exhaust plume is filled with particulates, as with coal smoke, allowing an aircraft to be spotted visually at long range.
In the end, the problem of burning HEF throughout the entire engine proved impossible to solve. Removing the buildup was difficult, and the wear it caused was something that materials science was unable to address. It was possible to burn it with relative ease in an afterburner, but this would only be effective on aircraft that used an afterburner for extended periods of time. Combined with the high cost of producing the fuel and the toxicity issues, the value of zip fuel was seriously reduced.
After interest in boranes as jet fuel waned, some small-scale research into their use as rocket fuel continued. This too proved to be a dead-end, as the solid boron oxides in the combustion products interfered with the expected thermodynamics, and the thrust advantages could not be realized.
History
Several studies were made into boronated fuels over the years, starting with the U.S. Army's rocket-related Project HERMES in the late 1940s, the U.S. Navy Bureau of Aeronautics's Project ZIP in 1952, and the U.S. Air Force's Project HEF (High Energy Fuels) in 1955. For much of the 1950s, zip fuels were considered to be the "next big thing" and considerable funds were expended on these projects in an effort to bring them into service. The Navy's name stuck, and all the boronated fuels became known as "zip fuels", although the Air Force's naming for the fuels themselves became common.
The main thrust of the Air Force's program was based on HEF-3, which seemed to be the most likely candidate for quick introduction. HEF became part of the WS-110 efforts to build a new long-range bomber to replace the B-52 Stratofortress with a design able to dash at speeds up to Mach 2. The initial designs from Boeing and North American Aviation (NAA) both used conventional fuels for takeoff and cruise, switching to HEF during the high-speed dash, burning it only in their afterburner sections. This avoided the main problems with HEF; by burning it only in the afterburners the problem with buildup on the turbine was eliminated, and since the afterburners were only used for takeoff and high-speed flight, the problems with the toxic exhaust were greatly reduced.
When the initial designs proved to be too expensive to justify their relatively small performance improvement, both returned to the drawing board and came up with new designs that flew at supersonic speeds for most of a combat mission. These designs were based around new engines designed for sustained high-speed flight, with the NAA B-70 Valkyrie and General Electric J93 progressing to the prototype stage. In these cases the afterburners were used for a longer period, maximizing the benefits of HEF. There were plans to introduce a later version of the J93 that would burn HEF-4 throughout. Meanwhile, there were also studies on using HEF-3 in the BOMARC ramjets, as well as studies about carrying it on the U.S. Navy's aircraft carrier fleet to power future aircraft, but these programs both died out.
As the problems were proving intractable, the Air Force canceled their program in 1959, and interest in zip essentially disappeared. By this point the only design still considering using HEF was the XB-70 and its J93. NAA and General Electric responded by redesigning the engine to run on a new higher-density form of jet fuel, JP-6, and filling one of the two bomb bays with a new fuel tank. In doing so the range was dramatically reduced from about . This reduced the selection of targets that could be attacked from the US and required in-flight refueling for every mission profile, one more problem that led to the project's eventual re-direction as a purely experimental aircraft.
It is estimated that the US spent about $1 billion on the program, in 2001 inflation-adjusted dollars. At least five HEF production plants were built in the US, and two workers were killed in an explosion that destroyed one plant in New York. Most of the program was classified Top Secret while being carried out, but nevertheless it was widely covered both in the trade press and civilian newspapers.
Both the US and Soviet Union independently declassified their research in 1964.
Zip fuel research led to the use of triethylborane as an ignition agent for the JP-7 fuel used in the SR-71 Blackbird.
One potentially lasting relic of the HEF program is an abandoned dirt airfield outside Boron, California. Marked on USGS topographical maps as "Air Force Plant #72", nothing but the airstrip and a water tank were ever built on the site. It is speculated that this would have been a factory for HEF fuel, using the large borax deposits nearby (giving the town its name), where it could be easily shipped to Edwards Air Force Base.
References
Sources
J. R. Cracknell, "High Energy Fuels", Flight International, 15 March 1956, pg. 332–334
M. Frederick Hawthorne, "From Mummies to Rockets and on to Cancer Therapy"
Dave Schubert, "From Missiles to Medicine: The development of boron hydrides", Pioneer, March 2001
"Boron Air Force Plant #72 Airfield, Boron, CA"
Aviation fuels | Zip fuel | [
"Engineering"
] | 1,791 | [
"Aviation fuels",
"Aerospace engineering"
] |
13,251,197 | https://en.wikipedia.org/wiki/Ion%20cyclotron%20resonance | Ion cyclotron resonance is a phenomenon related to the movement of ions in a magnetic field. It is used for accelerating ions in a cyclotron, and for measuring the masses of an ionized analyte in mass spectrometry, particularly with Fourier transform ion cyclotron resonance mass spectrometers. It can also be used to follow the kinetics of chemical reactions in a dilute gas mixture, provided these involve charged species.
Definition of the resonant frequency
An ion in a static and uniform magnetic field will move in a circle due to the Lorentz force. The angular frequency of this cyclotron motion for a given magnetic field strength B is given by
where z is the number of positive or negative charges of the ion, e is the elementary charge and m is the mass of the ion. An electric excitation signal having a frequency f will therefore resonate with ions having a mass-to-charge ratio m/z given by
The circular motion may be superimposed with a uniform axial motion, resulting in a helix, or with a uniform motion perpendicular to the field (e.g., in the presence of an electrical or gravitational field) resulting in a cycloid.
Ion cyclotron resonance heating
Ion cyclotron resonance heating (or ICRH) is a technique in which electromagnetic waves with frequencies corresponding to the ion cyclotron frequency is used to heat up a plasma. The ions in the plasma absorb the electromagnetic radiation and as a result of this, increase in kinetic energy. This technique is commonly used in the heating of tokamak plasmas.
In the solar wind
On March 8, 2013, NASA released an article according to which ion cyclotron waves were identified by its solar probe spacecraft called WIND as the main cause for the heating of the solar wind as it rises from the Sun's surface. Before this discovery, it was unclear why the solar wind particles would heat up instead of cool down, when speeding away from the Sun's surface.
See also
Cyclotron resonance
Electron cyclotron resonance
References
Condensed matter physics
Electric and magnetic fields in matter
Ion source
Scientific techniques
Plasma phenomena | Ion cyclotron resonance | [
"Physics",
"Chemistry",
"Materials_science",
"Engineering"
] | 444 | [
"Physical phenomena",
"Spectrum (physical sciences)",
"Plasma physics",
"Plasma phenomena",
"Ion source",
"Electric and magnetic fields in matter",
"Phases of matter",
"Materials science",
"Mass spectrometry",
"Condensed matter physics",
"Matter"
] |
13,252,222 | https://en.wikipedia.org/wiki/Relaxin%20receptor | The relaxin receptors are a subclass of four closely related G protein-coupled receptors (GPCR) that bind relaxin peptide hormones.
Below is list of human relaxin receptors, their endogenous peptide hormones, and what downstream enzymes are activated or inhibited by the receptor.
See also
Relaxin family peptide hormones
Insulin/IGF/Relaxin family
Relaxin/insulin-like family peptide receptor 1
References
External links
G protein-coupled receptors | Relaxin receptor | [
"Chemistry"
] | 92 | [
"G protein-coupled receptors",
"Signal transduction"
] |
13,252,599 | https://en.wikipedia.org/wiki/Distribution%20amplifier | In electronics, a distribution amplifier, or simply distribution amp or DA, is a device that accepts a single input signal and provides this same signal to multiple isolated outputs.
These devices allow a signal to be distributed to multiple destinations without ground loops or signal degradation. They are used for a number of common engineering tasks, including multiple amplification, cable television, splitting monitor and front of house mixes, and "tapping" a signal prior to sending it through effects units to preserve a "dry" signal for later experimentation.
Audio distribution amplifier
An audio distribution amplifier also known as: a press feed; a pool feed; a media feed; press box; or an ADA, takes a single audio feed, usually a line input, but it may be a microphone input, and outputs multiple line or microphone outputs. This can be done using a passive feed, where the signal is split among the outputs, or as an active feed where the outputs are amplified. The primary use of the Audio Distribution Amplifier is to share a single audio feed with multiple members of the press pool.
Video distribution amplifier
A video distribution amplifier (also known as a distribution amp or VDA) takes a video signal as an input, amplifies it, and outputs the amplified video signal to two or more outputs. It is primarily used to supply a single video signal to multiple pieces of video equipment. It adjusts the amplitude of a video signal to compensate for loss of signal in a video distribution system. Extending the distance of the video signal is the main purpose of the VDA. There are VDAs built for all video formats, NTSC, ATSC, QAM16, QAM32, QAM64, composite video and component video.
Their construction and capabilities can be simple; accept input signal, amplify, then output. Others can be more sophisticated and allow remote control from a control station, allow adjustment of the gain, equalization, and provide status of the input and output signals through Ethernet networks.
See also
Microphone splitter
References
External links
Info about some very common distribution amplifier types.
Guide to HDMI Distribution Amp, switches and matrix
Press feeds from distributor Whirlwind USA.
Consumer electronics
Video hardware
Television technology | Distribution amplifier | [
"Technology",
"Engineering"
] | 443 | [
"Information and communications technology",
"Electronic engineering",
"Television technology",
"Video hardware"
] |
13,253,184 | https://en.wikipedia.org/wiki/BMW%20M2B15 | The BMW M2B15 was BMW's first flat-twin engine. Manufactured from 1920 to 1923, the M2B15 was intended to be a portable industrial engine, but it was used by several German motorcycle manufacturers to power their motorcycles.
In 1920, BMW engineer Max Friz reverse-engineered the engine of foreman Martin Stolle's 1914 Douglas motorcycle and developed a similar 500 cc side-valve flat engine from it. This was referred to internally as the Type M2B15 and offered for sale officially as the "Bayern Motor". The engine was tried out by various motorcycle manufacturers. Starting in 1920, Victoria of Nuremberg used the engine in their KR 1 motorcycle, and other manufacturers such as SMW and Bison also fitted it.
Bayerische Flugzeugwerke used the M2B15 engine in their Helios motorcycle. BMW inherited the Helios when it was merged with BFW in 1922.
References
M2B15
Motorcycle engines
Boxer engines | BMW M2B15 | [
"Technology"
] | 196 | [
"Motorcycle engines",
"Engines"
] |
13,253,580 | https://en.wikipedia.org/wiki/False%20door | A false door, or recessed niche, is an artistic representation of a door which does not function like a real door. They can be carved in a wall or painted on it. They are a common architectural element in the tombs of ancient Egypt, but appeared possibly earlier in some Pre-Nuragic Sardinian tombs known as Domus de Janas. Later they also occur in Etruscan tombs and in the time of ancient Rome they were used in the interiors of both houses and tombs.
Mesopotamian origin
Egyptian architecture was influenced by Mesopotamian precedents, as it adopted elements of Mesopotamian Temple and civic architecture. These exchanges were part of Egypt-Mesopotamia relations since the 4th millennium BCE.
Recessed niches were characteristic of Mesopotamian Temple architecture, and were adopted in Egyptian architecture, especially for the design of Mastaba tombs, during the First Dynasty and the Second Dynasty, from the time of the Naqada III period (circa 3000 BCE). It is unknown if the transfer of this design was the result of Mesopotamian workmen in Egypt, or if temple designs appearing on imported Mesopotamian seals may have been a sufficient source of inspiration for Egyptian architects.
Ancient Egypt
The ancient Egyptians believed that the false door was a threshold between the worlds of the living and the dead and through which a deity or the spirit of the deceased could enter and exit.
The false door was usually the focus of a tomb's offering chapel, where family members could place offerings for the deceased on a special offering slab placed in front of the door.
Most false doors are found on the west wall of a funerary chapel or offering chamber because the Ancient Egyptians associated the west with the land of the dead. In many mastabas, both husband and wife buried within have their own false door.
Structure
A false door usually is carved from a single block of stone or plank of wood, and it was not meant to function as a normal door. Located in the center of the door is a flat panel, or niche, around which several pairs of door jambs are arranged—some convey the illusion of depth and a series of frames, a foyer, or a passageway. A semi-cylindrical drum, carved directly above the central panel, was used in imitation of the reed-mat that was used to close real doors.
The door is framed with a series of moldings and lintels as well, and an offering scene depicting the deceased in front of a table of offerings usually is carved above the center of the door. Sometimes, the owners of the tomb had statues carved in their image placed into the central niche of the false door.
Historical development
The configuration of the false door, with its nested series of doorjambs, is derived from the niched palace façade and its related slab stela, which became a common architectural motif in the early Dynastic period. The false door was used first in the mastabas of the Third Dynasty of the Old Kingdom (c. 27th century BCE) and its use became nearly universal in tombs of the fourth through sixth dynasties. Rarely, the Old Kingdom false door was combined with statues, demonstrating the common ancestry of the false door and naos in similar early ancient Egyptian architectural features. During the nearly one hundred and fifty years spanning the reigns of the sixth Dynasty pharaohs Pepi I, Merenre, and Pepi II, the false door motif went through a sequential series of changes affecting the layout of the panels, allowing historians to date tombs based on which style of false door was used. The same dating approach is used also for the First Intermediate Period.
After the First Intermediate Period, the popularity of the false doors diminished, being replaced by stelae as the primary surfaces for writing funerary inscriptions.
Representations of false doors also appeared on Middle Kingdom coffins such as the Coffin of Nakhtkhnum (MET 15.2.2a, b) dating to late Dynasty 12 (). Here, the false door is represented by two wooden doors that are secured with door bolts, bracketed on both sides by architectural niching – recalling earlier niched temple and palace façades such as the enclosure wall that surrounds the mortuary complex of king Djoser of the Third Dynasty. In a similar manner to the Old Kingdom false doors, representations of false doors on Middle Kingdom coffins facilitated the movement of the deceased's spirit between the afterlife and the world of the living.
Inscriptions
The side panels usually are covered in inscriptions naming the deceased along with their titles, and a series of standardized offering formulas. These texts extol the virtues of the deceased and express positive wishes for the afterlife.
For example, the false door of Ankhires reads:
The lintel reads:
The left and right outer jambs read:
Prehistoric Sardinia
Carved or painted Pre-Nuragic false doors appear in about 20 tombs mostly located in northwestern Sardinia, an example being some of the Domus de Janas of the necropolis of Anghelu Ruju, which are variously datable from the Ozieri to the Bonnanaro cultures of Pre-Nuragic Sardinia ().
These false doors, apparently resulting from a strong Eastern influence, usually appear on the back wall of the main chamber, and are represented by horizontal and vertical frames and a projecting lintel. Sometimes the door is topped with painted or carved U-shaped bull horns, inscribed inside each other in a variable number.
Unlike the Egyptian ones, the meaning of pre-Nuragic false doors is less clear. It has been argued that these represents the passageway to the afterlife that definitively separate the deceased from the living loved ones, also preventing a possible return. Alternatively, it is possible that these false doors are simply clues of the plan of the corresponding former house of the deceased.
Etruria
In Etruscan tombs the false door has a Doric design and is always depicted closed. Most often it is painted, but on some occasions it is carved in relief, like in the Tomb of the Charontes at Tarquinia. Unlike the false door in ancient Egyptian tombs, the Etruscan false door has given rise to a diversity of interpretations. It might have been the door to the underworld, similar to its use of the ancient Egypt. It could have been used to mark the place where a new doorway and chamber would be carved for future expansion of the tomb. Another possibility is that it is the door of the tomb itself, as seen from outside. In the Tomb of the Augurs at Tarquinia two men are painted to the left and right of a false door. Their gestures of lamentation indicate that the deceased were considered to be behind the door.
Ancient Rome
Painted doors were used frequently in the decoration of both First- and Second style interiors of Roman villas.
An example is the villa of Julius Polybius in Pompeii, where a false door is painted on a wall opposite a real door to achieve symmetry. Apart from creating architectural balance, they could serve to make the villa seem larger than it really was.
See also
Monumental inscription
References
Further reading
External links
Ancient Egypt from A to Z
Doors
Architectural elements
Egyptian artefact types
Burial monuments and structures
Naqada III | False door | [
"Technology",
"Engineering"
] | 1,448 | [
"Building engineering",
"Architectural elements",
"Components",
"Architecture"
] |
13,255,208 | https://en.wikipedia.org/wiki/Affect%20display | Affect displays are the verbal and non-verbal displays of affect (emotion). These displays can be through facial expressions, gestures and body language, volume and tone of voice, laughing, crying, etc. Affect displays can be altered or faked so one may appear one way, when they feel another (e.g., smiling when sad). Affect can be conscious or non-conscious and can be discreet or obvious. The display of positive emotions, such as smiling, laughing, etc., is termed "positive affect", while the displays of more negative emotions, such as crying and tense gestures, is respectively termed "negative affect".
Affect is important in psychology as well as in communication, mostly when it comes to interpersonal communication and non-verbal communication. In both psychology and communication, there are a multitude of theories that explain affect and its impact on humans and quality of life.
Theoretical perspective
Affect can be taken to indicate an instinctual reaction to stimulation occurring before the typical cognitive processes considered necessary for the formation of a more complex emotion. Robert B. Zajonc asserts that this reaction to stimuli is primary for human beings and is the dominant reaction for lower organisms. Zajonc suggests affective reactions can occur without extensive perceptual and cognitive encoding, and can be made sooner and with greater confidence than cognitive judgments.
Lazarus on the other hand considers affect to be post-cognitive. That is, affect is elicited only after a certain amount of cognitive processing of information has been accomplished. In this view, an affective reaction, such as liking, disliking, evaluation, or the experience of pleasure or displeasure, is based on a prior cognitive process in which a variety of content discriminations are made and features are identified, examined for their value, and weighted for their contributions.
A divergence from a narrow reinforcement model for emotion allows for other perspectives on how affect influences emotional development. Thus, temperament, cognitive development, socialization patterns, and the idiosyncrasies of one's family or subculture are mutually interactive in non-linear ways. As an example, the temperament of a highly reactive, low self-soothing infant may "disproportionately" affect the process of emotion regulation in the early months of life.
Non-conscious affect and perception
In relation to perception, a type of non-conscious affect may be separate from the cognitive processing of environmental stimuli. A monohierarchy of perception, affect and cognition considers the roles of arousal, attentional tendencies, affective primacy, evolutionary constraints, and covert perception within the sensing and processing of preferences and discrimination. Emotions are complex chains of events triggered by certain stimuli. There is no way to completely describe an emotion by knowing only some of its components. Verbal reports of feelings are often inaccurate because people may not know exactly what they feel, or they may feel several different emotions at the same time. There are also situations that arise in which individuals attempt to hide their feelings, and there are some who believe that public and private events seldom coincide exactly, and that words for feelings are generally more ambiguous than are words for objects or events.
Affective responses, on the other hand, are more basic and may be less problematic in terms of assessment. Brewin has proposed two experiential processes that frame non-cognitive relations between various affective experiences: those that are prewired dispositions (i.e., non-conscious processes), able to "select from the total stimulus array those stimuli that are casually relevant, using such criteria as perceptual salience, spatiotemporal cues, and predictive value in relation to data stored in memory", and those that are automatic (i.e., subconscious processes), characterized as "rapid, relatively inflexible and difficult to modify... (requiring) minimal attention to occur and... (capable of being) activated without intention or awareness" (1989 p. 381).
Arousal
Arousal is a basic physiological response to the presentation of stimuli. When this occurs, a non-conscious affective process takes the form of two control mechanisms; one mobilization, and the other immobilization. Within the human brain, the amygdala regulates an instinctual reaction initiating this arousal process, either freezing the individual or accelerating mobilization.
The arousal response is illustrated in studies focused on reward systems that control food-seeking behavior. Researchers focused on learning processes and modulatory processes that are present while encoding and retrieving goal values. When an organism seeks food, the anticipation of reward based on environmental events becomes another influence on food seeking that is separate from the reward of food itself. Therefore, earning the reward and anticipating the reward are separate processes and both create an excitatory influence of reward-related cues. Both processes are dissociated at the level of the amygdala and are functionally integrated within larger neural systems.
Affect and mood
Mood, like emotion, is an affective state. However, an emotion tends to have a clear focus (i.e., a self-evident cause), while mood tends to be more unfocused and diffused. Mood, according to Batson, Shaw, and Oleson (1992), involves tone and intensity and a structured set of beliefs about general expectations of a future experience of pleasure or pain, or of positive or negative affect in the future. Unlike instant reactions that produce affect or emotion, and that change with expectations of future pleasure or pain, moods, being diffused and unfocused, and thus harder to cope with, can last for days, weeks, months, or even years. Moods are hypothetical constructs depicting an individual's emotional state. Researchers typically infer the existence of moods from a variety of behavioral referents.
Positive affect and negative affect represent independent domains of emotion in the general population, and positive affect is strongly linked to social interaction. Positive and negative daily events show independent relationships to subjective well-being, and positive affect is strongly linked to social activity. Recent research suggests that "high functional support is related to higher levels of positive affect". The exact process through which social support is linked to positive affect remains unclear. The process could derive from predictable, regularized social interaction, from leisure activities where the focus is on relaxation and positive mood, or from the enjoyment of shared activities.
Gender
Research has indicated many differences in affective displays due to gender. Gender, as opposed to sex, is one's self-perception of being masculine or feminine (i.e., a male can perceive himself to be more feminine or a female can perceive herself to be more masculine). It can also be argued, however, that hormones (typically determined by sex) greatly affect affective displays and mood.
Affect and child development
According to studies done in the late '80s and early '90s, infants within their first year of life are not only able to begin recognizing affect displays but can begin mimicking the displays and also begin developing empathy. A study in 2011 followed up on these earlier studies by testing fifteen 6-12 month old infants' arousal, via pupil dilation, when looking at both positive and negative displays. Results showed that when presented with negative affect, an infant's pupil will dilate and stay dilated for a longer period of time when compared to neutral affect. When presented with positive affect however, the pupil dilation is much larger, but stays dilated for shorter amount of time. While this study does not prove an infant's ability to empathize with others, it does show that infants do recognize and acknowledge both positive and negative displays of emotion.
In the early 2000s over the period of about seven years, a study was done on about 200 children whose mother had "a history of juvenile-onset unipolar depressive disorder" or simply, depression as children themselves. In the cases of unipolar depression, a person generally displays more negative affect and less positive affect than a person without depression. Or, they are more likely to show when they are sad or upset, than when they are excited or happy. This study that was published in 2010 discovered that the children of mothers that have unipolar depression, had lower levels of positive affect when compared to the control group. Even as the children grew older, while the negative affect began to stay the same, the children still showed consistently lower positive affect. This study suggests that "Reduced PA [positive affect] may be one source of developmental vulnerability to familial depression..." meaning that while having family with depression, increases the risk of children developing depression, reduced positive affect increases the risk of this development. But knowing this aspect of depression, might also be able to help prevent the onset of depression in young children well into their adulthood.
Disorders and physical disabilities
There are some diseases, physical disabilities and mental health disorders that can change the way a person's affect displays are conveyed. Reduced affect is when a person's emotions cannot be properly conveyed or displayed physically. There is no actual change in how intensely they truly feel emotions; there is simply a disparity between emotions felt and how intensely they are conveyed. These disorders can greatly affect a person's quality of life, depending on how intense the disability is.
Flat, blunted and restricted affect
These are symptoms in which an affected person feels an emotion, but does not or cannot display it. Flat being the most severe in where there is very little to absolutely no show of emotions. Restricted and blunted are, respectively, less severe. Disorders involving these reduced affect displays most commonly include schizophrenia, post traumatic stress disorder, depression, autism and persons with traumatic brain injuries. One study has shown that people with schizophrenia that experience flat affect, can also experience difficulty perceiving the emotions of a healthy individual.
Facial paralysis and surgery
People who have facial deformities or paralysis may also be physically incapable of displaying emotions. This is beginning to be corrected though, through "Facial Reanimation Surgery" which is proving not only to successfully improve a patient's affect displays, but also bettering their psychological health. There are multiple types of surgeries that can help fix facial paralysis. Some more popular types include fixing the actual nerve damage, specifically any damage to the hypoglossal nerve; facial grafts where nerves taken from a donor's leg are transplanted into the patient's face; or if the damage is more muscular versus actual nerves, muscle may be transferred into the patient's face.
Strategic display
Emotions can be displayed in order to elicit desired behaviors from others.
People have been known to display positive emotions in various settings. Service workers often engage in emotional labor, a strive to maintain positive emotional expressions despite difficulties in working conditions or rude customers, in order to conform to organizational rules. Such strategic displays are not always effective, since if they are detected, lower customer satisfaction results.
Perhaps the most notable attempt to feign negative emotion could be seen with Nixon's madman theory. Nixon's administration attempted to make the leaders of other countries think Nixon was mad, and that his behavior was irrational and volatile. Fearing an unpredictable American response, leaders of hostile Communist Bloc nations would avoid provoking the United States. This diplomatic strategy was not ultimately successful.
The effectiveness of the strategic display depends on the ability of the expresser to remain undetected. It may be a risky strategy since if detected, the person's original intent could be discovered, undermining the future relationship with the target.
According to the appraisal theory of emotions, the experience of emotions is preceded by an evaluation of an object of significance to that individual. When individuals are seen to display emotions, it serves as a signal to others of an event important to that individual. Thus, deliberately altering the emotion display toward an object could be used make the targets of the strategic emotion think and behave in ways that benefit the original expresser. For example, people attempt to hide their expressions during a poker game in order to avoid giving away information to the other players, i.e., keep a poker face.
See also
Affect (psychology)
Affect theory
Affective
Affective spectrum
Deception
Discrete emotions theory
Display rules
Emotion
Emotional contagion
Emotional labor
Empathy
Facial communication
Interpersonal deception theory
Psychopathy
Self-awareness
Self-deception
Sincerity
Silvan Tomkins
References
Emotion
Evolutionary psychology | Affect display | [
"Biology"
] | 2,510 | [
"Emotion",
"Behavior",
"Human behavior"
] |
13,255,720 | https://en.wikipedia.org/wiki/Information%20repository | In information technology, an information repository or simply a repository is "a central place in which an aggregation of data is kept and maintained in an organized way, usually in computer storage." It "may be just the aggregation of data itself into some accessible place of storage or it may also imply some ability to selectively extract data."
Universal digital library
The concept of a universal digital library was described as "within reach" by a 2012 European Union Copyright Directive which told about Google's attempts to "mass-digitize" what are termed "orphan works" (i.e. out-of-print copyrighted works).
The U.S. Copyright Office and the European Union Copyright law have been working on this. Google has reached agreements in France which "lets the publisher choose which works can be scanned or sold." By contrast, Google has been trying in the USA for a "free to digitize and sell any works unless the copyright holders opted out" deal and is still unsuccessful.
Information repository
Attempts to develop what was called an information repository'' have been underway for decades:
In 1989, IBM tried to have OfficeVision combine mainframes and PCs to enable "an information repository."
In 2003, Microsoft introduced OneNote as an extension to Microsoft Office 2003; it would support "a personal information repository."
In 1996, an 1898-founded library obtained additional funding to expand its mission, and become a major "local resource center and regional information repository." The New York Times described them as "the second largest in the New York City region, second only to the New York Public Library on Fifth Avenue." Their services include "a computer information center devoted to outside-item requests."
Federated information repository
A federated information repository is an easy way to deploy a secondary tier of data storage that can comprise multiple, networked data storage technologies running on diverse operating systems, where data that no longer needs to be in primary storage is protected, classified according to captured metadata, processed, de-duplicated, and then purged, automatically, based on data service level objectives and requirements. In federated information repositories, data storage resources are virtualized as composite storage sets and operate as a federated environment.
Federated information repositories were developed to mitigate problems arising from data proliferation and eliminate the need for separately deployed data storage solutions because of the concurrent deployment of diverse storage technologies running diverse operating systems. They feature centralized management for all deployed data storage resources. They are self-contained, support heterogeneous storage resources, support resource management to add, maintain, recycle, and terminate media, track of off-line media, and operate autonomously.
Automated data management
Since one of the main reasons for the implementation of a federated information repository is to reduce the maintenance workload placed on IT staff by traditional data storage systems, federated information repositories are automated. Automation is accomplished via policies that can process data based on time, events, data age, and data content. Policies manage the following:
File system space management
Irrelevant data elimination (mp3, games, etc.)
Secondary storage resource management
Data is processed according to media type, storage pool, and storage technology.
Because federated information repositories are intended to reduce IT staff workload, they are designed to be easy to deploy and offer configuration flexibility, virtually limitless extensibility, redundancy, and reliable failover.
Data recovery
Federated information repositories feature robust, client based data search and recovery capabilities that, based on permissions, enable end users to search the information repository, view information repository contents, including data on off-line media, and recover individual files or multiple files to either their original network computer or another network computer.
References
Data management
Data security
Records management | Information repository | [
"Technology",
"Engineering"
] | 773 | [
"Data management",
"Cybersecurity engineering",
"Data security",
"Data"
] |
13,255,999 | https://en.wikipedia.org/wiki/List%20of%20academic%20computer%20science%20departments | List
Academic computer science departments
Computer | List of academic computer science departments | [
"Technology"
] | 8 | [
"Computing-related lists"
] |
13,256,745 | https://en.wikipedia.org/wiki/Planetary%20nebula%20luminosity%20function | Planetary nebula luminosity function (PNLF) is a secondary distance indicator used in astronomy. It makes use of the [O III] λ5007 forbidden line found in all planetary nebula (PNe) which are members of the old stellar populations (Population II).
It can be used to determine distances to both spiral and elliptical galaxies despite their completely different stellar populations and is part of the Extragalactic Distance Scale.
Procedure
The distance estimate to a galaxy using the PNLF requires discovery of such an object in the target galaxy that is visible at λ5007 but not when the entire spectrum is considered. These points are candidate PNe, however, there are three other types of objects that would also exhibit such an emission line that must be filtered out: HII regions, supernova remnants, and Lyα galaxies. After the PNe are determined, to estimate a distance one must measure their monochromatic [O III] λ5007 luminosity. What remains is a statistical sample of
PNe. The observed luminosity function is then fitted to some standard law.
Finally, one must estimate the foreground interstellar extinction. The two sources of extinction, are from within the Milky Way and the internal extinction of the target galaxy. The first is well known and can be taken from sources such as reddening maps computed from H I measurements and galaxy counts or from IRAS and DIRBE satellite experiments. The later type of extinction, occurs only in target galaxies which are either late type spiral or irregular. However, this extinction is difficult to measure. In the Milky Way, the scale height of PNe is much bigger than that of the dust. Observational data and models support that this holds true for other galaxies, that the bright edge of the PNLF is primarily due to PNe in front of the dust layer. The data and models support a less than 0.05 apparent magnitude internal extinction of a galaxy's PNe.
Physics behind process
The PNLF method is unbiased by metallicity. This is because oxygen is a primary nebular coolant; any drop in its concentration raises the plasma's electron temperature and raises the amount of collisional excitations per ion. This compensates for having a smaller number of emitting ions in the PNe resulting in little change in the λ5007 emissions . Consequently, a reduction in oxygen density only lowers the emergent [O III] λ5007 emission line intensity by approximately the square root of the difference in abundance. At the same time, the PNe's core responds to metallicity the opposite way. In the case where the metallicity of the progenitor star is smaller, the PNe's central star will be a bit more massive and its illuminating ultraviolet flux will be a bit greater. This added energy almost precisely accounts for the decreased emissions of the PNe. Consequently, the total [O III] λ5007 luminosity that is produced by a PNe is practically
uncorrelated to metallicity. This beneficial negation is in agreement with more precise models of PNe evolution. Only in extremely metal-poor PNe does the brightness of the PNLF cutoff dim by more than a small percentage.
The relative independence of the PNLF cutoff with respect to population age is harder to understand. The [O III] λ5007 flux of a PNe directly correlates to the brightness of its central star. Further, the brightness of its central star directly correlates to its mass and the central star's mass directly varies in relation to its progenitor's mass. However, by observation, it is demonstrated that reduced brightness does not happen.
Notes
References
Large-scale structure of the cosmos
Planetary nebulae
Physical cosmology
Standard candles | Planetary nebula luminosity function | [
"Physics",
"Astronomy"
] | 772 | [
"Astronomical sub-disciplines",
"Standard candles",
"Theoretical physics",
"Astrophysics",
"Physical cosmology"
] |
13,256,800 | https://en.wikipedia.org/wiki/Motion%20system | Motion system in engineering and systems, is a component of a test and measurement system that provides motion to a load or loads in a one or many directions. Generally a motion system is made up of a set (or stack) of linear and rotational stages. A linear stage moves in a straight line, while a rotation stage moves in a partial or full circle. A stage can either be manually controlled with a knob control, or automated with a motion controller.
A motion system generally is computer controlled and can perform fast, reliable, repeatable, and accurate positioning of loads. Most systems will support motion in X and Y directions, which is referred to as an XY stack. Often either a Z axis (up/down motion) or R axis (rotational motion) is placed on top of the XY stack.
For automated stages, a scale can be attached to the internals of the stage and an encoder used to measure the position on the scale and report this to the controller, thereby determining the precise position of the stage. This allows for a motion controller to reliably and repeatably move to set positions with the linear stage.
See also
Linear stage
System of measurement
Motion controller
External links
Motion Basics and Standards
Systems engineering | Motion system | [
"Engineering"
] | 249 | [
"Systems engineering"
] |
8,618,239 | https://en.wikipedia.org/wiki/Hardware%20functionality%20scan | A hardware functionality scan (HFS) is conducted in order to verify that a certain device is really what it claims to be. It is patented by Microsoft.
Some operating systems only send copy protected content, such as movies, to an output device, such as the screen, if that device is able to protect the content from being tapped in an unprotected format. This mechanism can be circumvented by letting fake hardware claiming to be a trusted device. HFS prevents this by letting the device perform certain tasks which are hard to emulate.
Problems
In order to support open-source drivers, a hardware manufacturer has to reveal some details about their product, but HFS requires this information to be kept secret. The problem with generic drivers is that the HFS requires individual drivers for each variant of a product to make them distinguishable, drivers have to account for implementation details instead of using abstract functionality models.
A hardware manufacturer has to have their product's HFS fingerprint listed in the database of trusted hardware in order to make it work under newer Windows operating systems. Thus, Microsoft dictates the conditions under which a device is accepted. The manufacturer may be required to implement certain DRM-features, for which they have to pay a royalty to its respective inventor.
References
Digital rights management systems
Proprietary hardware | Hardware functionality scan | [
"Technology"
] | 268 | [
"Computer security stubs",
"Computing stubs"
] |
8,618,787 | https://en.wikipedia.org/wiki/Mobile%20porn | Mobile porn, also known as mobile adult content, mobile erotica or cellphone adult content, is pornography transmitted over mobile telecommunications networks for consumption on mobile devices (mainly mobile phones, tablets and smartphones).
History
Just like the internet and pay TV, the adult entertainment industry was one of the first forms of mass media to embrace mobile devices as a new means to distribute content. During 2002, Private Media Group became the first adult media company to employ a dedicated mobile specialist. This initiative led to the industry's first adult SMS services, erotic mobile content distribution and mobile internet (WAP) site, called "Private Mobile", offering a small range of videos directly to their consumers. This service was intended for the increasing range of Private consumers using feature phones in Europe with colour screens.
From the mid-2000s onwards, many mobile network operators eventually deployed age verification systems and industry-regulated explicitness grading levels that gradually allowed mobile erotica to be legally purchased through gated mobile operator portal communities only by consenting adults.
With the onset of smartphones in 2007 and portable tablet computers thereafter, more and more consumers in developed markets have since left these gated mobile operator communities and now browse the internet on their mobile and apps instead for their mobile erotica.
Widespread adoption of Apple's iPhone was initially expected to encourage growth in the mobile erotica industry. Following the release of the original iPhone in 2007, the search term "iPhone Porn" spiked considerably in popularity. with 37% of iPhone users watching video on their iPhone However, Apple chairman Steve Jobs made it clear that no adult content would ever be sold from Apple's App Store, and thousands of adult apps have been banned on the App Store. However, Apple's ban on adult apps has been criticized as being impractical and ineffective.
Other companies in the mobile and video industries situated themselves to take advantage of this trend. Google built a new phone system called Google Play that supports any application within reasonable decency guidelines. Since then, dedicated adult-only app stores like MiKandi and other mobile internet publishers have benefited from this gap in the market instead.
Following its inception in 2002, the mobile erotica business was expected to grow to a market value of $2.3 billion within its first eight years.
North America
The North American mobile erotica market differs from Europe in that carriers were slow to allow adult sites to use their subscriber payment mechanisms such as SMS, slowing market growth. Alternate business models involve offering free videos in the 'tube' style of websites with advertising funding. For the cost of viewing an ad, users can get free video clips.
Verizon Wireless and Sprint Nextel Corporation announced as late as 2008 that they would allow some adult content to be viewed on their networks, while working to prevent access to this content by children. There have been expectations for some time that these companies will overcome age-verification, political, and religious challenges that have become a barrier to this market, to take advantage of the resulting increase in mobile web-surfing on their networks.
Criticisms
There has been some criticism of mobile porn, namely the exposure of children to inappropriate and unregulated content. However, most mobile network operators have implemented age verification systems, which require that customers who want to buy porn through their phone legally prove that they are a consenting adult first.
Sony, the company which created the PlayStation Portable (PSP), say that they are unhappy with the spread of PSP porn, but claim to be unable to stop its spread.
See also
MiKandi
Private Media Group
References
Pornography by genre
Mobile content | Mobile porn | [
"Technology"
] | 724 | [
"Mobile content"
] |
8,619,255 | https://en.wikipedia.org/wiki/Computational%20logic | Computational logic is the use of logic to perform or reason about computation. It bears a similar relationship to computer science and engineering as mathematical logic bears to mathematics and as philosophical logic bears to philosophy. It is an alternative term for "logic in computer science".
Computational logic has also come to be associated with logic programming, because much of the early work in logic programming in the early 1970s also took place in the Department of Computational Logic in Edinburgh. It was reused in the early 1990s to describe work on extensions of logic programming in the EU Basic Research Project "Compulog" and in the associated Network of Excellence. Krzysztof Apt, who was the co-ordinator of the Basic Research Project Compulog-II, reused and generalized the term when he founded the ACM Transactions on Computational Logic in 2000 and became its first Editor-in-Chief.
The term “computational logic” came to prominence with the founding of the ACM Transactions on Computational Logic in 2000. However, the term was introduced much earlier, by J.A. Robinson in 1970. The expression is used in the second paragraph with a footnote claiming that "computational logic" is "surely a better phrase than 'theorem proving', for the branch of artificial intelligence which deals with how to make machines do deduction efficiently".
In 1972 the Metamathematics Unit at the University of Edinburgh was renamed “The Department of Computational Logic” in the School of Artificial Intelligence. The term was then used by Robert S. Boyer and J Strother Moore, who worked in the Department in the early 1970s, to describe their work on program verification and automated reasoning. They also founded Computational Logic Inc.
See also
Logic programming
Automated theorem proving
Type theory
Formal verification
References
Further reading
Logic in computer science
Computational fields of study | Computational logic | [
"Mathematics",
"Technology"
] | 363 | [
"Mathematical logic",
"Logic in computer science",
"Computing and society",
"Computational fields of study"
] |
8,619,670 | https://en.wikipedia.org/wiki/Polytetrahedron | Polytetrahedron is a term used for three distinct types of objects, all based
on the tetrahedron:
A uniform convex 4-polytope made up of 600 tetrahedral cells. It is more commonly known as a 600-cell or hexacosichoron. Other derivative 4-polytope are identified as polytetrahedra, where a qualifying prefix such as rectified or truncated is used.
A connected set of regular tetrahedra, the 3-dimensional analogue of a polyiamond. Polytetrahedra and polyiamonds are related as polycubes are related to polyominoes.
In origami, a polypolyhedron is "a compound of multiple linked polyhedral skeletons with uniform nonintersecting edges" . There exist two topologically distinct polytetrahedra, each made up of four intersecting triangles.
See also
Compound of five tetrahedra
Compound of ten tetrahedra
References
4-polytopes
Polyhedra
Paper folding | Polytetrahedron | [
"Mathematics"
] | 213 | [
"Recreational mathematics",
"Paper folding",
"Geometry",
"Geometry stubs"
] |
8,619,843 | https://en.wikipedia.org/wiki/Wattle%20%28anatomy%29 | A wattle is a fleshy caruncle hanging from various parts of the head or neck in several groups of birds and mammals. Caruncles in birds include those found on the face, wattles, dewlaps, snoods, and earlobes. Wattles are generally paired structures but may occur as a single structure when it is sometimes known as a dewlap. Wattles are frequently organs of sexual dimorphism. In some birds, caruncles are erectile tissue and may or may not have a feather covering.
Wattles are often such a striking morphological characteristic of animals that they feature in their common name. For example, the southern and northern cassowaries are known as the double-wattled and single-wattled cassowary, respectively, and a breed of domestic pig is known as the Red Wattle.
Birds
Function
In birds, wattles are often an ornament for courting potential mates. Large wattles are correlated with high testosterone levels, good nutrition, and the ability to evade predators, which in turn indicates a potentially successful mate. Ornamental organs such as wattles may be associated with genes coding for disease resistance. In umbrellabirds, the wattle serves to amplify the birds' calls.
Examples
Birds with wattles include:
From the neck or throat
Birds of the genus Casuarius: the northern, southern, and dwarf cassowaries
Galliformes (e.g., wild turkeys, chickens)
Some vultures
Some lapwings
The male of the wattled starling
Some Australian wattlebirds (Anthochaera spp.)
The New Zealand wattlebirds (Callaeidae), which include the kōkako, tīeke or saddleback, and the huia
The wattled crane (Bugeranus carunculatus)
Three neotropical bellbird species
From below or around the eyes
The African wattle-eye or puffback flycatcher
The wattled jacana (Jacana jacana)
The African wattled lapwing (Vanellus senegallus)
Many male pheasants
Spectacled tyrant
Gracula hill mynas
Muscovy duck (Cairina moschata)
The English carrier pigeon
Mammals
Mammals with wattles include:
Some domestic goats have fleshy, fur-covered protuberances, called tassels, hanging on either side of the throat.
Some domestic pigs, such as the Kunekune, Lithuanian Native pig, and Red Wattle have a fleshy protuberance hanging on either side of the throat.
Gallery
See also
Dewlap
Casque (anatomy)
Crest (feathers)
Comb (anatomy) - the fleshy structure present atop the heads of many Galliform species
Frontal shield
Gular pouch
Dubbing (poultry) - wattle amputation
References
Birds
Bird anatomy
Vertebrate anatomy | Wattle (anatomy) | [
"Biology"
] | 575 | [
"Birds",
"Animals"
] |
8,620,083 | https://en.wikipedia.org/wiki/1%2C2%2C4-Butanetriol | 1,2,4-Butanetriol is an organic compound with the formula . It is an colorless, odorless, hygroscopic, oily liquid. Containing three alcohol groups, it is classified as a polyol, similar to glycerol and erythritol. It is chiral.
Uses
1,2,4-Butanetriol is used in the manufacture of butanetriol trinitrate (BTTN), an important component of US military rocket motor solid fuel. As of 2014, it was commercially produced by a single Chinese company.
1,2,4-Butanetriol is also used as a precursor for two cholesterol-lowering drugs, Crestor and Zetia, which are derived from D-3,4-dihydroxybutanoic acid, by using 3-hydroxy-gamma-butyrolactone as a chiral synthon
It is used as one of the monomers for manufacture of some polyesters and as a solvent.
Preparation
1,2,4-Butanetriol can be prepared synthetically by several methods, such as hydroformylation of glycidol and subsequent reduction of the product. It can also be prepared by reduction of malic acid esters with sodium borohydride. The oxidation of butynediol with mercuric oxide followed by reduction of the resulting ketone.
Genetically engineered bacteria produce these triols in enantiopure form. Pseudomonas fragi converts D-xylose to D-xylonic acid, which is decarboxylated by a strain of Escherichia coli to D-triol. Similarly, D-arabinose is converted to D-arabinonic acid, which is converted to the L-triol.
References
Triols
Monomers
Alcohol solvents | 1,2,4-Butanetriol | [
"Chemistry",
"Materials_science"
] | 389 | [
"Monomers",
"Polymer chemistry"
] |
8,620,216 | https://en.wikipedia.org/wiki/1%2C2%2C4-Butanetriol%20trinitrate | 1,2,4-Butanetriol trinitrate (BTTN), also called butanetriol trinitrate, is an important military propellant. It is a colorless to brown explosive liquid.
BTTN is used as a propellant in virtually all single-stage missiles used by the United States, including the Hellfire. It is less volatile, less sensitive to shock, and more thermally stable than nitroglycerine, for which it is a promising replacement.
BTTN as a propellant is often used in a mixture with nitroglycerin. The mixture can be made by co-nitration of butanetriol and glycerol. BTTN is also used as a plasticizer in some nitrocellulose-based propellants.
BTTN is manufactured by nitration of 1,2,4-butanetriol. Biotechnological manufacture of butanetriol is under intensive research.
References
External links
WebBook page for 1,2,4-Butanetriol, trinitrate
Nitrate esters
Explosive chemicals
Liquid explosives
Propellants | 1,2,4-Butanetriol trinitrate | [
"Chemistry"
] | 241 | [
"Explosive chemicals"
] |
8,620,449 | https://en.wikipedia.org/wiki/Leray%E2%80%93Hirsch%20theorem | In mathematics, the Leray–Hirsch theorem is a basic result on the algebraic topology of fiber bundles. It is named after Jean Leray and Guy Hirsch, who independently proved it in the late 1940s. It can be thought of as a mild generalization of the Künneth formula, which computes the cohomology of a product space as a tensor product of the cohomologies of the direct factors. It is a very special case of the Leray spectral sequence.
Statement
Setup
Let
be a fibre bundle with fibre . Assume that for each degree , the singular cohomology rational vector space
is finite-dimensional, and that the inclusion
induces a surjection in rational cohomology
.
Consider a section of this surjection
,
by definition, this map satisfies
.
The Leray–Hirsch isomorphism
The Leray–Hirsch theorem states that the linear map
is an isomorphism of -modules.
Statement in coordinates
In other words, if for every , there exist classes
that restrict, on each fiber , to a basis of the cohomology in degree , the map given below is then an isomorphism of modules.
where is a basis for and thus, induces a basis for
Notes
Fiber bundles
Theorems in algebraic topology | Leray–Hirsch theorem | [
"Mathematics"
] | 252 | [
"Theorems in algebraic topology",
"Theorems in topology"
] |
8,620,616 | https://en.wikipedia.org/wiki/Parallel%20compression | Parallel compression, also known as New York compression, is a dynamic range compression technique used in sound recording and mixing. Parallel compression, a form of upward compression, is achieved by mixing an unprocessed 'dry', or lightly compressed signal with a heavily compressed version of the same signal. Rather than lowering the highest peaks for the purpose of dynamic range reduction, it decreases the dynamic range by raising up the softest sounds, adding audible detail. It is most often used on stereo percussion buses in recording and mixdown, on electric bass, and on vocals in recording mixes and live concert mixes.
History
The internal circuitry of Dolby A noise reduction, introduced in 1965, contained parallel buses with compression on one of them, the two mixed in a flexible ratio. In October 1977, an article by Mike Beville was published in Studio Sound magazine describing the technique as applied to classical recordings. Many citations of this article claim that Beville called it "side-chain" compression, most likely due to a misquoting of a citation of the article in Roey Izhaki's book, Mixing Audio: Concepts, Practices and Tools. However, Beville used the term "side-chain" to describe the internal electronics and signal flow of compressors, not to describe a technique for using compressors. His discussion of parallel compression technique occurs in a separate section at the end of the article where he outlines how to place a limiter-compressor "in parallel with the direct signal" to obtain effective compression at low input levels. As Izhaki mentions in his book, others have referred to the technique as "side-chain" compression, which has made for confusion with the side-chain compression technique which uses an external "key" or "side chain" signal to determine compression on a target signal.
Beville's article, entitled "Compressors and Limiters," was reprinted in the same magazine in June 1988. A follow-up article by Richard Hulse in the April 1996 Studio Sound included application tips and a description of implementing the technique in a digital audio workstation. Bob Katz coined the term "parallel compression", and has described it as an implementation of "upward compression", the increase in audibility of softer passages. Studio engineers in New York City became known for reliance on the technique, and it picked up the name "New York compression".
Use
The human ear is sensitive to loud sounds being suddenly reduced in volume, but less so to soft sounds being increased in volume—parallel compression takes advantage of this difference. Unlike normal limiting and downward compression, fast transients in music are retained in parallel compression, preserving the "feel" and immediacy of a live performance. Because the method is less audible to the human ear, the compressor can be set aggressively, with high ratios for strong effect.
In an audio mix using an analog mixing console and analog compressors, parallel compression is achieved by sending a monophonic or stereo signal in two or more directions and then summing the multiple pathways, mixing them together by ear to achieve the desired effect. One pathway is straight to the summing mixer, while other pathways go through mono or stereo compressors, set aggressively for high-ratio gain reduction. The compressed signals are brought back to the summing mixer and blended in with the straight signal.
If digital components are being used, latency must be taken into account. If the normal analog method is used for a digital compressor, the signals traveling through the parallel pathways will arrive at the summing mixer at slightly different times, creating unpleasant comb-filtering and phasing effects. The digital compressor pathway takes a little more time to process the sound—on the order of 0.3 to 3 milliseconds longer. Instead, the two pathways must both have the same number of processing stages: the "straight" pathway is assigned a compression stage which is not given an aggressively high ratio. In this case, the two signals both go through compression stages, and both pathways are delayed the same amount of time, but one is set to do no dynamic range compression, or to do very little, and the other is set for high amounts of gain reduction.
The method can be used artistically to "fatten" or "beef up" a mix, by careful setting of attack and release times on the compressor. These settings may be adjusted further until the compressor causes the signal to "pump" or "breathe" in tempo with the song, adding its own character to the sound. Unusually extreme implementations have been achieved by studio mix engineers such as New York-based Michael Brauer who uses five parallel compressors, adjusted individually for timbral and tonal variations, mixed and blended to taste, to achieve his target sound on vocals for the Rolling Stones, Aerosmith, Bob Dylan, KT Tunstall and Coldplay. Mix engineer Anthony "Rollmottle" Puglisi uses parallel compression applied conservatively across the entire mix, especially in dance-oriented electronic music: "it gives a track that extra oomph and power (not just make it louder—there's a difference) through quieter portions of the jam without resorting to one of those horrific 'maximizer' plugins that squeeze the dynamics right out of your song." While parallel compression is widely utilized in electronic dance music, "side-chain" compression is the technique popularly used to give a synth lead or other melodic element the pulsating quality ubiquitous in the genre. One or more tracks may be side-chained to the kick, thereby compressing them only when the beat occurs.
References
External links
How to Use Parallel Compression in Pro Tools 8
Audio Samples of Parallel Compression on Drums
Audio engineering
Dynamics processing | Parallel compression | [
"Engineering"
] | 1,155 | [
"Electrical engineering",
"Audio engineering"
] |
8,620,994 | https://en.wikipedia.org/wiki/Copper%28I%29%20acetylide | Copper(I) acetylide, Kupfercarbid or cuprous acetylide, is a chemical compound with the formula Cu2C2. Although never characterized by X-ray crystallography, the material has been claimed at least since 1856. One form is claimed to be a monohydrate with formula . is a reddish-brown explosive powder.
Synthesis
Materials purported to be copper acetylide can be prepared by treating acetylene with a solution of copper(I) chloride and ammonia:
C2H2 (g) + 2 CuCl (s) → Cu2C2 (s) + 2 HCl (g)
This reaction produces a reddish solid precipitate.
Properties
When dry, copper acetylide is a heat and shock sensitive primary explosive, more sensitive than silver acetylide.
In acetylene manufacturing plants, copper acetylide is thought to form inside pipes made of copper or an alloy with high copper content, which may result in violent explosion. This led to abandonment of copper as a construction material in such facilities. Copper catalysts used in the chemical industry can also possess a degree of risk under certain conditions.
Reactions
Copper acetylide is the substrate of Glaser coupling for the formation of polyynes. In a typical reaction, a suspension of . in an amoniacal solution is treated with air. The copper is oxidized to and forms a blue soluble complex with the ammonia, leaving behind a black solid residue. The latter has been claimed to consist of carbyne, an elusive allotrope of carbon:<ref name=cataldo2>Franco Cataldo (1999), ' 'A study on the structure and electrical properties of the fourth carbon allotrope: carbyne. Polymer International, volume 44, issue 2, pages 191–200.
</ref>
−C(≡C−C≡)nC−
This interpretation has been disputed.
Freshly prepared copper acetylide reacts with hydrochloric acid to form acetylene and copper(I) chloride. Samples that have been aged with exposure to air or to copper(II) ions liberate also higher polyynes H(−C≡C−)nH, with n'' from 2 to 6, when decomposed by hydrochloric acid. A "carbonaceous" residue of this decomposition also has the spectral signature of (−C≡C−)n chains. It has been conjectured that oxidation causes polymerization of the acetylide anions in the solid into carbyne-type anions .C(≡C−C≡)nC2− or polycumulene-type anions C(=C=C=)mC4−.
Thermal decomposition of copper acetylide in vacuum is not explosive and leaves copper as a fine powder at the bottom of the flask, while depositing a fluffy very fine carbon powder on the walls. On the basis of spectral data, this powder was claimed to be carbyne C(−C≡C−)nC rather than graphite as expected.
Applications
Though not practically useful as an explosive due to high sensitivity, it is interesting as a curiosity because it is one of the very few explosives that do not liberate any gaseous products upon detonation.
The formation of copper acetylide when a gas is passed through a solution of copper(I) chloride is used as a test for the presence of acetylene.
Reactions between Cu+ and alkynes occur only if a terminal hydrogen is present (as it is slightly acidic in nature). Thus, this reaction is used for identification of terminal alkynes.
See also
Carbide
Walter Reppe
Ethynylation
References
Copper(I) compounds
Acetylides
Explosive chemicals | Copper(I) acetylide | [
"Chemistry"
] | 775 | [
"Explosive chemicals"
] |
8,621,096 | https://en.wikipedia.org/wiki/CTGF | CTGF, also known as CCN2 or connective tissue growth factor, is a matricellular protein of the CCN family of extracellular matrix-associated heparin-binding proteins (see also CCN intercellular signaling protein). CTGF has important roles in many biological processes, including cell adhesion, migration, proliferation, angiogenesis, skeletal development, and tissue wound repair, and is critically involved in fibrotic disease and several forms of cancers.
Structure and binding partners
Members of the CCN protein family, including CTGF, are structurally characterized by having four conserved, cysteine-rich domains. These domains are, from N- to C-termini, the insulin-like growth factor binding protein (IGFBP) domain, the von Willebrand type C repeats (vWC) domain, the thrombospondin type 1 repeat (TSR) domain, and a C-terminal domain (CT) with a cysteine knot motif. CTGF exerts its functions by binding to various cell surface receptors in a context-dependent manner, including integrin receptors, cell surface heparan sulfate proteoglycans (HSPGs), LRPs, and TrkA. In addition, CTGF also binds growth factors and extracellular matrix proteins. The N-terminal half of CTGF interacts with aggrecan, the TSR domain interacts with VEGF, and the CT domain interacts with members of the TGF-β superfamily, fibronectin, perlecan, fibulin-1, slit, and mucins.
Role in development
Knockout mice with the Ctgf gene disrupted die at birth due to respiratory stress as a result of severe chondrodysplasia. Ctgf-null mice also show defects in angiogenesis, with impaired interaction between endothelial cells and pericytes and collagen IV deficiency in the endothelial basement membrane. CTGF is also important for pancreatic beta cell development, and is critical for normal ovarian follicle development and ovulation.
Clinical significance
CTGF is associated with wound healing and virtually all fibrotic pathology. It is thought that CTGF can cooperate with TGF-β to induce sustained fibrosis and to exacerbate extracellular matrix production in association other fibrosis-inducing conditions. Overexpression of CTGF in fibroblasts promotes fibrosis in the dermis, kidney, and lung, and deletion of Ctgf in fibroblasts and smooth muscle cells greatly reduces bleomycin-induced skin fibrosis.
In addition to fibrosis, aberrant CTGF expression is also associated with many types of malignancies, diabetic nephropathy and retinopathy, arthritis, and cardiovascular diseases. Several clinical trials are now ongoing that investigate the therapeutic value of targeting CTGF in fibrosis, diabetic nephropathy, and pancreatic cancer.
CTGF (CCN2) has recently been implicated in mood disorders, notably in the postpartum period; these effects may be mediated by its effects on myelination
See also
Ctgf/hcs24 CAESAR
CYR61 (CCN1)
References
External links
Growth factors
CCN proteins | CTGF | [
"Chemistry"
] | 683 | [
"Growth factors",
"Signal transduction"
] |
8,621,397 | https://en.wikipedia.org/wiki/List%20of%20online%20databases | This is a list of online databases accessible via the Internet.
A
Abandoned & Little-Known Airfields
Academic OneFile
Acronym Finder
Adult Film Database
Aeiou Encyclopedia
Airiti Inc
Airliners.net
All Media Guide
Allgame (down)
Allmovie
Allmusic
American National Corpus
Animal Diversity Web
Animal Genome Size Database
Animator.ru
Arachne
ArchINFORM
Archive site
ArtCyclopedia
Amazon.com
Aviation Safety Reporting System
B
Bank of English
Beilstein database
BiblioPage.com
Bibliotek.dk
Big Cartoon DataBase
Big Comic Book DataBase
Bioinformatic Harvester
BoardGameGeek
C
CAMPUS
Catholic-Hierarchy.org
CellarTracker
ChEBI
Chemical Abstracts Service
Chessgames.com
China Pollution Map Database
CIDOB Foundation
Cinema and Science
CiteSeer
ClassRanked.com
Collection of Computer Science Bibliographies
Comic book price guide
Comics Buyer's Guide
Credo Reference
Croatian National Corpus
Current Biography
D
DBLP
DIALOG
Dictionary of Canadian Biography
Discogs
E
Earth Human STR Allele Frequencies Database
ELDIS
EMBASE
Encyclopedia Astronautica
Encyclopedia Mythica
English Short Title Catalogue
Entrez
Everyone's a Critic
F
Factiva
Facts on File
Fashion Model Directory
Filmarchives online
Filmweb
Find a Grave
FINDbase (the Frequency of INherited Disorders database)
FishBase
Flags of the World
Flora Europaea
G
Gallica
GameRankings
GeneNetwork
GeoNames
Gesamtkatalog der Wiegendrucke
Getty Thesaurus of Geographic Names
Golm Metabolome Database
Google
Grand Comics Database
H
Hong Kong Movie DataBase
Hoover's
HotPads.com
I
IGDB (Internet Games Database)
IMDb (Internet Movie Database)
INDUCKS
IndexMaster
Informit (database)
Inorganic Crystal Structure Database
Interment.net
Internet Adult Film Database
Internet Archive
Internet Broadway Database
Internet Movie Cars Database
Internet Movie Firearms Database
Internet Off-Broadway Database
Internet Public Library
Internet Speculative Fiction Database
Internet Theatre Database
ISBNdb.com
J
Jewish Virtual Library
Jointly Administered Knowledge Environment
JSTOR
K
Kdo byl kdo
Killer List of Videogames
L
Lattes
Lesson Planet
LexisNexis
The Literary Encyclopedia
M
Media Bias/Fact Check
MedlinePlus
Metacritic
Metropolitan Travel Survey Archive
MICAD
Mindat.org
MobyGames
Movie Review Query Engine
Moviemistakes.com
MovieTome
MSDSonline
MusicBrainz
MyAnimeList
MySql
N
Names Database
Newsknowledge
Nichigai WHO
NNDB
O
Omniglot
On-Line Encyclopedia of Integer Sequences
Open Source Vulnerability Database
P
Paradisec
PHI-base
Philosophy Research Index
Plant DNA C-values Database
Plants for a Future
Price guide
ProBiS
ProQuest
Proteomics Identifications Database
PsycINFO
PubChem
PubMed Central
Q
Questia – defunct
R
Rate Your Music
REBASE Restriction Enzyme Database
RedLightGreen
Reptile Database
Roller Coaster DataBase
Roud Folk Song Index
S
Scots Law Times
SeatGuru
Sharecare
Sherdog
The Simpsons Archive
The Skyscraper Center
SmealSearch
Svenskt Diplomatarium
T
TCM Movie Database
Textfiles.com
TheTVDB
Tocsearch
TOSEC
Transterm
Truthfinder
TV.com
U
Uchronia: The Alternate History List
Ultimate Guitar Archive
V
Vastari
VET-Bib
Virtuoso Universal Server
W
Web of Science
Whitepages (company)
Who's Who (UK)
WinCustomize
Wind ENergy Data & Information (WENDI) Gateway
Wikidata
World Biographical Information System Online
World Wide Molecular Matrix
WorldCat
Z
Zaask
Zabasearch.com
Zendy.io
Zillow
ZINC database
See also
List of academic databases and search engines
List of biodiversity databases
List of chemical databases
List of neuroscience databases
List of ontologies
References
Databases
Databases | List of online databases | [
"Technology"
] | 750 | [
"Computing-related lists",
"Internet-related lists"
] |
8,622,325 | https://en.wikipedia.org/wiki/Triangulation%20sensor | Optical Triangulation Sensors are commonly used to provide door mounted safety detection on swinging automatic doors. These types of sensors are common in North America. When automatic swinging doors open and close, it is important that they do not come into contact with pedestrians passing through the door.
Classification
Sensors used in the automatic door industry typically fall into four categories:
Microwave sensors used to detect motion of a person as they approach an automatic door,
Reflective optical sensors that are mounted on the door header, and detect the presence of a person in the door path
Camera based sensors that are also mounted on the door header and similarly detect presence; and
Triangulation sensors which are mounted on the door and move with the door to provide safety.
Reflective and camera technologies do not perform well on moving swing doors, because they typically depend upon detection of changes in the background. A sensor mounted on a swing door system is constantly in motion, so the background (i.e. floor beneath the door) changes continuously. A triangulation sensor overcomes this problem.
Functionality
In most cases, an optical triangulation sensor is mounted near the top of the swinging door frame, inside a long extruded aluminum tube with an optical window facing the floor. An LED light source emits a collimated, near-infrared light beam. The beam bounces off the floor and is received by a photodiode positioned adjacent to the LED source. A second photodiode (or a linear array of photodiodes) is positioned farther along the length of the sensor.
When the emitted beam bounces off the floor, the reflected energy is almost exclusively concentrated on the first adjacent photodiode. When a human or object moves into the optical path, the reflected beam bounces back from the object. Since the beam is no longer traveling the full optical path length to the floor, its reflected angle changes. One of the adjacent photodiodes then receives the optical energy and the sensor responds by sending a signal to the automatic door controller. At that point the door stops, slows or reverses, hence averting a collision and providing safety.
Triangulation sensors are found on a number of door brands, and manufactured by several sensor manufacturers. One example is the SuperScan-II from BEA. Other products from other manufacturers are also available.
Safety standards
ANSI A156.10-2005 standard for U.S. Automatic Pedestrian Doors
American Association of Automatic Door Manufacturers (AAADM)
DIN 18650 Automatic Door Standard (Germany)
Door automation
Electromechanical engineering | Triangulation sensor | [
"Engineering"
] | 510 | [
"Door automation",
"Automation",
"Electromechanical engineering",
"Mechanical engineering by discipline",
"Electrical engineering"
] |
8,623,048 | https://en.wikipedia.org/wiki/Tail%20%28Chinese%20constellation%29 | The Tail mansion (尾宿, pinyin: Wěi Xiù) is one of the Twenty-eight mansions of the Chinese constellations. It is one of the eastern mansions of the Azure Dragon.
Asterisms
References
Chinese constellations | Tail (Chinese constellation) | [
"Astronomy"
] | 48 | [
"Chinese constellations",
"Constellations"
] |
8,623,889 | https://en.wikipedia.org/wiki/David%20Eisenberg | David S. Eisenberg (born 15 March 1939) is an American biochemist and biophysicist best known for his contributions to structural biology and computational molecular biology. He has been a professor at the University of California, Los Angeles since the early 1970s and was director of the UCLA-DOE Institute for Genomics & Proteomics, as well as a member of the California NanoSystems Institute (CNSI) at UCLA.
Education
Eisenberg attended Harvard University and graduated in 1961 with an A.B. in Biochemical Sciences. He went on to the University of Oxford, where he was awarded a D.Phil in 1965 for research supervised by Charles Coulson.
Research
Eisenberg's current research focuses on the structural biology of amyloidogenic proteins, while his computational efforts largely center on the development of bioinformatic/proteomic methodologies for elucidation and analysis of protein interaction networks. His research group hosts the Database of Interacting Proteins.
Career
Postdoctoral research, Princeton University (1964–1966; with Walter Kauzmann)
Postdoctoral research, California Institute of Technology (1966–1969; with Richard E. Dickerson)
Professor, Department of Chemistry & Biochemistry, UCLA, USA (1969–Present)
Professor, Department of Biological Chemistry, UCLA Medical School
Director, UCLA-DOE Institute for Genomics & Proteomics (1993–2014)
Member, California NanoSystems Institute (CNSI), UCLA
Investigator, Howard Hughes Medical Institute (2001–Present)
Awards
He was the recipient of Harvey Prize (Human Health) 2008 in recognition of his contributions in unfolding the structure of amyloid fibrils. The award was presented to him at a ceremony that took place on March 23, 2009 at the Technion. This recently recognized protein state provides opportunities to understand cells in health and disease.
1961 - L.J. Henderson Prize
1958-1960 - Harvard College Honorary Scholarships
1961-1964 - Rhodes Scholarship
1972-1977 - USPHS Career Development Award
1975 - UCLA Distinguished Teaching Award
1982 - McCoy Award of the UCLA Department of Chemistry and Biochemistry for innovative research
1989 - Member, National Academy of Sciences (Biophysics & Computational Biology section)
1992 - Pierce Award of the Immunotoxin Society
1996 - Protein Society Stein & Moore Award
1998 - American Chemical Society Repligen Corporation Award in Chemistry of Biological Processes
2000 - Investigator, Howard Hughes Medical Institute
2000 - Amgen Award of the Protein Society
2001 - Fellow, American Association for the Advancement of Science
2003 - Member, American Philosophical Society
2004 - UCLA Glenn T. Seaborg Medal
2005 - Harvard University's Westheimer Medal
2008 - ACS Nobel Laureate Signature Award for Graduate Education in Chemistry (as preceptor, student was Rebecca Anne Nelson)
2013 - ISCB (International Society for Computational Biology) Senior Scientist Award
2020 - Passano Award
References
1939 births
Living people
Harvard University alumni
Howard Hughes Medical Investigators
American biophysicists
Jewish American scientists
University of California, Los Angeles faculty
Members of the United States National Academy of Sciences
Fellows of the International Society for Computational Biology
Members of the American Philosophical Society
21st-century American Jews
Members of the National Academy of Medicine
Structural biologists | David Eisenberg | [
"Chemistry"
] | 636 | [
"Structural biologists",
"Structural biology"
] |
8,624,045 | https://en.wikipedia.org/wiki/School%20timetable | A school timetable is a calendar that coordinates students and teachers within the classrooms and time periods of the school day. Other factors include the class subjects and the type of classrooms available (for example, science laboratories).
Since the 1970s, researchers in operations research and management science have developed computerized solutions for the school timetable problem (STP).
Description and purpose of a school timetable
A school timetable consists of a list of the complete set of offered courses, as well as the time and place of each course offered. The purposes of the school timetable are to inform teachers when and where they teach each course, and to enable students to enroll in a subset of courses without schedule conflicts.
History
Prior to the introduction of operations research and management science methodologies, school timetables had to be generated by hand. Hoshino and Fabris wrote, "As many school administrators know, creating a timetable is incredibly difficult, requiring the careful balance of numerous requirements (hard constraints) and preferences (soft constraints). When timetables are constructed by hand, the process is often 10% mathematics and 90% politics, leading to errors, inefficiencies, and resentment among teachers and students."
For the simplest school timetable, such as an elementary school, these conditions must be satisfied:
a teacher cannot teach two courses in the same time slot
no classroom can be used by two courses simultaneously
each teacher has a set of unavailable teaching timeslots.
Hoshino and Fabris describe other conditions of real-life timetabling problems, that
Since the 1970s, researchers have developed computerized solutions to manage the complex constraints involved in building school timetables. In 1976, for example, Gunther Schmidt and Thomas Ströhlein formalized the STP with an iterative algorithm using logical matrices and hypergraphs.
Nelishia Pillay published a comprehensive survey paper of these algorithms in 2014, including a table of methods for solving the school timetabling problem.
High school
High school timetables are quite different from university timetables. The main difference is that in high schools, students have to be occupied and supervised every hour of the school day, or nearly every hour. Also, high school teachers generally have much higher teaching loads than is the case in universities. As a result, it is generally considered that university timetables involve more human judgement whereas high school timetabling is a more computationally intensive task (see the constraint satisfaction problem).
Selected other options
The task of constructing a high school timetable may involve the following options (not an exhaustive list):
Part-time teachers need to have certain entire days off. They will either specify to the school which weekdays they are or simply how many days per cycle they need off. Such teachers can greatly add to the difficulty of timetabling when they are assigned to large blocks.
Sometimes there are 2 or 3 subjects which rotate between student bodies throughout the year. For example, the 8A students might take Art in the first half of the year and Music in the second half.
Off-timetable lessons: sometimes an occasional lesson is scheduled "off the timetable" meaning before school, after school, or during lunch. This usually happens with older students. It can be a desperate response to intractable timetabling problems or a compromise reached in order for the school to be able to offer less popular subjects.
Abbreviations: In the United States «TTh» (or sometimes «TTH» or «T-TH») and «MWF» or «M-W-F» are used as unofficial short-hands for «Tuesdays and Thursdays» and «Mondays, Wednesdays and Fridays». They are used when columns need to be very narrow on tables where the extra characters would create an unintended new row or other unwanted formatting issues.
See also
Block scheduling: When students have fewer, longer classes each day.
Modular scheduling
Schedule
References
External links
International Timetabling Competition 2007
Robertus J. Willemen, School timetable construction, Algorithms and complexity
Planning
Educational time organization
Timetable, school
Time management | School timetable | [
"Physics"
] | 817 | [
"Spacetime",
"Physical quantities",
"Time",
"Time management"
] |
8,624,081 | https://en.wikipedia.org/wiki/BlogML | BlogML is an open format derived from XML to store and restore the content of a blog.
History
BlogML was originally created by Darren Neimke in August 2005 by starting a Workspace on GotDotNet community. In July 2006, BlogML was moved to CodePlex for better open-source development and some other developers joined this project. BlogML has hit three versions so far. Versions 0.9 and 1.0 released on GotDotNet and version 2.0 released on CodePlex. After moving this project to CodePlex, Keyvan Nayyeri joined this project and added some new features for BlogML 2.0.
In addition to BlogML specification, there is a rich set of .NET Framework APIs provided by the BlogML team for .NET developers to work with markup easier.
BlogML is supported by many .NET blogging tools such as Community Server, Subtext, Single User Blog, BlogEngine.NET, DasBlog and the Orchard Project. Also there are some implementations for other blogging engines and services such as Blogger.
Main goals
BlogML is created for some main goals:
Ability to port blog content between Blog Engines:
This is the case where one has a blog based on .Text version 0.95 and wants to upgrade to Community Server. Having an "Export to BlogML" in .Text and an "Import from BlogML" function in Community Server solves this problem.
Ability to port blog content between Blog Engine Versions:
Same as above.
Ability to port blog content between Storage Providers:
This is the case where one might be using a blogging engine such as Single User Blog and is running from one provider - such as DotTextProvider (where the content reads and writes to an existing .Text schema) and wants to continue to use Single User Blog but move to a new data structure. In this case one configures Single User Blog to use the DotTextProvider and run an "Export to BlogML" function, then re-configure the provider to thenative provider and run the "Import from BlogML" function.
Ability to easily back-up a blog:
Here one run some sort of scheduled job to automatically run the "Export to BlogML" function and save the output as a compressed backup file somewhere.
License
BlogML is licensed under BSD license.
References
External links
BlogML
Web syndication formats
XML-based standards
Computer file formats | BlogML | [
"Technology"
] | 497 | [
"Computer standards",
"XML-based standards"
] |
8,624,261 | https://en.wikipedia.org/wiki/Hajime%20Tanabe | was a Japanese philosopher of science, particularly of mathematics and physics. His work brought together elements of Buddhism, scientific thought, Western philosophy, Christianity, and Marxism. In the postwar years, Tanabe coined the concept of metanoetics, proposing that the limits of speculative philosophy and reason must be surpassed by metanoia.
Tanabe was a key member of what has become known in the West as the Kyoto School, alongside philosophers Kitaro Nishida (also Tanabe's teacher) and Keiji Nishitani. He taught at Tōhoku Imperial University beginning in 1913 and later at Kyōto Imperial University, and studied at the universities of Berlin, Leipzig, and Freiburg in the 1920s under figures such as Edmund Husserl and Martin Heidegger. In 1947 he became a member of the Japan Academy, and in 1950 he received the Order of Cultural Merit.
Biography
Tanabe was born on February 3, 1885, in Tokyo to a household devoted to education. His father, the principal of Kaisei Academy, was a scholar of Confucius, whose teachings may have influenced Tanabe's philosophical and religious thought. Tanabe enrolled at Tokyo Imperial University, first as a mathematics student before moving to literature and philosophy. After graduation, he worked as a lecturer at Tohoku University and taught English at Kaisei Academy.
In 1916, Tanabe translated Henri Poincaré’s La Valeur de la science. In 1918, he received his doctorate from Kyoto Imperial University with a dissertation entitled ‘Investigations into the Philosophy of Mathematics’ (predecessor to the 1925 book with the same title).
In 1919, at Nishida’s invitation, Tanabe accepted the position of associate professor at Kyoto Imperial University. From 1922 to 23, he studied in Germany — first, under Alois Riehl at the University of Berlin and then under Edmund Husserl at the University of Freiburg. At Freiburg, he befriended the young Martin Heidegger and Oskar Becker. One can recognise the influence of these philosophers in Tanabe.
In September 1923, soon after the Great Kantō Earthquake, the Home Ministry ordered his return, so Tanabe used the little time he had left — about a couple of months — to visit London and Paris, before boarding his return ship at Marseille. He arrived back in Japan in 1924.
In 1928, Tanabe translated Max Planck’s 1908 lecture, ‘Die Einheit des physikalischen Weltbildes’ for the Philosophical Essays [哲学論叢] translation series, which he co-edited, for his publisher Iwanami Shoten. The same series published translations of essays by Bruno Bauch, Adolf Reinach, Wilhelm Windelband, Siegfried Marck, Max Planck, Franz Brentano, Paul Natorp, Nicolai Hartmann, Kazimierz Twardowski, Ernst Cassirer, Hermann Cohen, Emil Lask, Victor Brochard, Ernst Troeltsch, Theodor Lipps, Konrad Fiedler, Wincenty Lutosławski, Sergei Rubinstein, Hermann Bonitz, Max Weber, Émile Durkheim, Martin Grabmann, Heinrich Rickert, Alexius Meinong, Karl von Prantl and Wilhelm Dilthey (the series ended before the planned translations of Christoph von Sigwart, Carl Stumpf, Edmund Husserl, Clemens Baeumker, Josiah Royce and Hermann Ebbinghaus were published).
After Nishida's retirement from teaching in 1928, Tanabe succeeded him. Though they began as friends, and shared several philosophical concepts such as the absolute nothing [絶対無], Tanabe became increasingly critical of Nishida's philosophy. Many of Tanabe's writings after Nishida left the university obliquely attacked the latter's philosophy.
In 1935, Tanabe published his essay ‘The Logic of Species and the World Schema’ wherein he formulated his own ‘logic of species’ for which he became known.
During the Japanese expansion and war effort, Tanabe worked with Nishida and others to maintain the right for free academic expression. Though he criticized the Nazi-inspired letter of Heidegger, Tanabe himself was caught up in the Japanese war effort, and his letters to students going off to war exhibit many of the same terms and ideology used by the reigning military powers. Even more damning are his essays written in defense of Japanese racial and state superiority, exploiting his theory of the Logic of Species to herald and abet the militaristic ideology. This proposed dialectic argued that every contradictory opposition is to be mediated by a third term in the same manner a species mediates a genus and an individual.
During the war years, however, Tanabe wrote and published little, perhaps reflecting the moral turmoil that he attests to in his monumental post-war work, Philosophy as Metanoetics. The work is framed as a confession of repentance (metanoia) for his support of the war effort. It purports to show a philosophical way to overcome philosophy itself, which suggests that traditional Western thought contained seeds of the ideological framework that led to World War II.
His activities, and the actions of Japan as a whole, haunted Tanabe for the rest of his life. In 1951, he writes:
He lived for another eleven years after writing these words, dying in 1962 in Kita-Karuizawa, Japan.
Thought
As James Heisig and others note, Tanabe and other members of the Kyoto School accepted the Western philosophical tradition stemming from the Greeks. This tradition attempts to explain the meaning of human experience in rational terms. This sets them apart from other Eastern writers who, though thinking about what life means and how best to live a good life, spoke in religious terms.
Although the Kyoto School used Western philosophical terminology and rational exploration, they made these items serve the purpose of presenting a unique vision of reality from within their cultural heritage. Specifically, they could enrich a discussion of the ultimate nature of reality using the experience and thought of various forms of Buddhism like Zen and Pure Land, but embedded in an analysis that calls upon conceptual tools forged and honed in western philosophy by thinkers ranging from Plato to Descartes to Heidegger.
Tanabe's own contribution to this dialog between Eastern and Western philosophy ultimately sets him apart from the other members of the Kyoto School. His radical critique of philosophical reason and method, while stemming from Immanuel Kant and Søren Kierkegaard, which emerges in his work Philosophy as Metanoetics, easily sets him as a major thinker with a unique position on perennial philosophical questions. Some commentators, for example, suggest that Tanabe's work in metanoetics is a forerunner of deconstruction.
Tanabe engaged with philosophers of Continental philosophy, especially Existentialism. His work is often a dialogue with philosophers like Kierkegaard, Friedrich Nietzsche, and Heidegger. Because of his engaging these thinkers, especially the first two, Tanabe's thought has been characterized as Existentialist, though Makoto Ozaki writes that Tanabe preferred the terms "existentialist philosophy of history", "historical existentialism", or "existential metaphysics of history". In his masterpiece, Philosophy as Metanoetics, Tanabe characterized his work as "philosophy that is not a philosophy", foreshadowing various approaches to thinking by deconstructionists.
Like other Existentialists, Tanabe emphasizes the importance of philosophy as being meaning; that is, what humans think about and desire is finding a meaning to life and death. In company with the other members of the Kyoto School, Tanabe believed that the foremost problem facing humans in the modern world is the lack of meaning and its consequent Nihilism. Jean-Paul Sartre, following Kierkegaard in his Concept of Anxiety, was keen to characterize this as Nothingness. Heidegger, as well, appropriated the notion of Nothingness in his later writings.
The Kyoto School philosophers believed that their contribution to this discussion of Nihilism centered on the Buddhist-inspired concept of nothingness, aligned with its correlate Sunyata. Tanabe and Nishida attempted to distinguish their philosophical use of this concept, however, by calling it Absolute Nothingness. This term differentiates it from the Buddhist religious concept of nothingness, as well as underlines the historical aspects of human existence that they believed Buddhism does not capture.
Tanabe disagreed with Nishida and Nishitani on the meaning of Absolute Nothingness, emphasizing the practical, historical aspect over what he termed the latter's intuitionism. By this, Tanabe hoped to emphasize the working of Nothingness in time, as opposed to an eternal Now. He also wished to center the human experience in action rather than contemplation, since he thought that action embodies a concern for ethics whereas contemplation ultimately disregards this, resulting in a form of Monism, after the mold of Plotinus and Georg Wilhelm Friedrich Hegel. That is, echoing Kierkegaard's undermining in Philosophical Fragments of systematic philosophy from Plato to Baruch Spinoza to Hegel, Tanabe questions whether there is an aboriginal condition of preexisting awareness that can or must be regained to attain enlightenment.
Tanabe's insistence on this point is not simply philosophical and instead points again to his insistence that the proper mode of human being is action, especially ethics. However, he is critical of the notion of a pre-existing condition of enlightenment because he accepts the Kantian notion of radical evil, wherein humans exhibit an ineluctable propensity to act against their own desires for the good and instead perpetrate evil.
Tanabe's "Demonstration of Christianity" presents religion as a cultural entity in tension with the existential meaning that religion plays in individual lives. Tanabe uses the terms genus to represent the universality of form that all entities strive for, contrasting them with the stable, though ossified form they can become as species as social systems.
Tanabe contraposes Christianity and Christ, represented here as the opposition between Paul and Jesus. Jesus, in Tanabe's terms, is a historical being who manifests the action of Absolute Nothingness, or God understood in non-theistic terms. God is beyond all conceptuality and human thinking, which can only occur in terms of self-identity, or Being. God becomes, as manifested in human actions, though God can never be reduced to being, or self-identity.
For Tanabe, humans have the potential to realize compassionate divinity, Nothingness, through continual death and resurrection, by way of seeing their nothingness. Tanabe believes that the Christian Incarnation narrative is important for explaining the nature of reality, since he believed Absolute Nothingness becoming human exemplifies the true nature of the divine, as well as exemplar to realization of human being in relationship to divinity. Jesus signifies this process in a most pure form, thereby setting an example for others to follow.
Ultimately, Tanabe chooses philosophy over religion, since the latter tends toward socialization and domestication of the original impulse of the religious action. Philosophy, understood as metanoetics, always remains open to questions and the possibility self-delusion in the form of radical evil. Therefore, Tanabe's statement is a philosophy of religion.
Bibliography
Primary sources
Collected Works [田邊元全集], 15 vols. (Chikuma Shobō [筑摩書房], 1963–64) [CW].
Selected Philosophical Works [田辺元哲学選], 4 vols. (Iwanami Bunko [岩波文庫], 2010) [SPW].
Monographs
Modern Natural Science [最近の自然科学] (Iwanami Shoten [岩波書店], November 1915), reprinted in CW2:1-153.
Philosophy of Science [科学概論] (Iwanami Shoten [岩波書店], September 1918), reprinted in CW2:155-360.
Kant’s Teleology [カントの目的論] (Iwanami Shoten [岩波書店], October 1924), reprinted in CW3:1-72.
Investigations into the Philosophy of Mathematics [数理哲学研究] (Iwanami Shoten [岩波書店], May 1925), reprinted in CW2:361-661.
Hegel’s Philosophy and the Dialectic [ヘーゲル哲学と辯證法] (Iwanami Shoten [岩波書店], January 1932), reprinted in CW3:73-369.
General Philosophy [哲学通論] (Iwanami Shoten [岩波書店], December 1933), reprinted in CW3:371-522.
The Two Sides to Natural Science Education [自然科学教育の両側面] (Monbushō [文部省], March 1937), reprinted in CW5:141-191.
The Meaning of Historical Study [史学の意味] (Nippon Bunka Kyōkai Shuppanbu [日本文化協会出版部], August 1937), reprinted in CW8:33-91.
Science as Morality [徳性としての科学] (Tokyo: Sūgakukyoku [数学局], August 1938), reprinted in CW5:329-83.
My View of the Philosophy of Shōbōgenzō [正法眼蔵の哲学私観] (Iwanami Shoten [岩波書店], May 1939), reprinted in CW5:443-494.
Between Philosophy and Science [哲学と科学の間] (Iwanami Shoten [岩波書店], November 1939), reprinted in CW5:193-327.
Historical Reality [歴史的現実] (Iwanami Shoten [岩波書店], June 1940), reprinted in CW8:117-169.
The Direction of Philosophy [哲学の方向] (Meguro Shoten [目黒書店], April 1941), reprinted in CW8:171-199.
Philosophy as a Way to Repentance: Metanoetics [懺悔道としての哲学] (Iwanami Shoten [岩波書店], April 1946), reprinted in CW9:1-269 and SPW2:33-439.
Urgent Matters for Political Philosophy [政治哲学の急務] (Chikuma Shobō [筑摩書房], June 1946), reprinted in CW8:323-395.
Dialectic of the Logic of Species [種の論理の辯證法] (Akitaya [秋田屋], November 1947), reprinted in CW7:251-372.
Existence, Love and Practice [実存と愛と実践] (Chikuma Shobō [筑摩書房], December 1947), reprinted in CW9:271-492.
Dialectic of Christianity [キリスト教の辯證] (Chikuma Shobō [筑摩書房], June 1948), reprinted in CW10:1-269.
Introduction to Philosophy: The Fundamental Problems of Philosophy [哲学入門——哲学の根本問題] (Chikuma Shobō [筑摩書房], March 1949), reprinted in CW11:1-132 and SPW3:11-216.
The Fundamental Problems of Philosophy, Appendix 1: Philosophy of History and Political Philosophy [哲学の根本問題補説第一——歴史哲学・政治哲学] (Chikuma Shobō [筑摩書房], September 1949), reprinted in CW11:133-282.
The Fundamental Problems of Philosophy, Appendix 2: Philosophy of Science and Epistemology [哲学の根本問題補説第二——科学哲学・認識論] (Chikuma Shobō, April 1950), reprinted in CW11:283-425.
Valéry’s Aesthetics [ヴァレリイの芸術哲学] (Chikuma Shobō [筑摩書房], March 1951), reprinted in CW13:1-162.
Fundamental Problems of Philosophy, Appendix 3: Philosophy of Religion and Ethics [哲学の根本問題補説第三——宗教哲学・倫理学] (Chikuma Shobō [筑摩書房], April 1952), reprinted in CW11:427-632.
Historicist Development of Mathematics: A Memorandum on the Foundations of Mathematics [数理の歴史主義展開——数学基礎論覚書] (Chikuma Shobō [筑摩書房], November 1954), reprinted in CW12:209-334 and SPW3:217-399.
Tanabe’s magnum opus, in his own words the “final accounting” of his philosophy.
Proposition of a New Methodology for Theoretical Physics: The Necessity of Theory of Functions of Complex Variables qua Method of Theoretical Physics and Its Topological Character [理論物理学新方法論提説——理論物理学の方法としての複素変数関数論の必然性とその位相学的性格] (Chikuma Shobō [筑摩書房], May 1955), reprinted in CW12:335-368.
Dialectic of the Theory of Relativity [相対性理論の辯證法] (Chikuma Shobō [筑摩書房], October 1955), reprinted in CW12:369-402.
A Memorandum on Mallarmé [マラルメ覚書] (Chikuma Shobō [筑摩書房], August 1961), reprinted in CW13:199-304 and SPW4:63-218.
Chronological list of works
1910
‘On Thetic Judgement’ [措定判断に就て] (Tetsugaku Zasshi [哲学雑誌], No. 283, September 1910), reprinted in CW1:1-10.
Tanabe develops Alois Riehl’s idea of »setzendes (thetisches) Urteil« from the latter’s Der philosophische Kriticismus und seine Bedeutung.
‘Critical Notice of Theodor Lipps’s Bewusstsein und Gegenstände’ [リップス氏『意識と対象』] (Tetsugaku Zasshi [哲学雑誌], No. 285, November 1910), reprinted in CW14:3-10.
1911
‘Critical Notice of Wilhelm Jerusalem’s Der kritische Idealismus und die reine Logik’ [イェルザレム氏の『批判的観念論と純粋論理学』] (Tetsugaku Zasshi [哲学雑誌], No. 292 and No. 293, June–July 1911), reprinted in CW14:11-32.
1912
‘The Problem of Relativity’ [相対性の問題] (Tetsugaku Zasshi [哲学雑誌], No. 302, April 1912), reprinted in CW14:33-48.
‘Kant and Natural Science’ [カントと自然科学] (Tetsugaku Zasshi [哲学雑誌], No. 306, August 1912), reprinted in CW14:49-60.
‘Critical Notice of Émile Boutroux’s De l’idée de loi naturelle dans la science et la philosophie contemporaines’ [ブートルー氏『自然法の観念』] (Tetsugaku Zasshi [哲学雑誌], No. 307, No. 308 and No. 309, September–November 1912), reprinted in CW14:61-104.
‘Critical Notice of Kuwaki Ayao’s ‘The Problem of Knowledge in Physics’’ [桑木理学士の『物理学上認識の問題』] (Tetsugaku Zasshi [哲学雑誌], No. 310, December 1912), reprinted in CW14:105-113.
1913
‘Critical Notice of Max Planck’s ‘Die Einheit des physkalischen Weltbildes’’ [プランク氏『物理学的世界形象の統一』] (Tetsugaku Zasshi [哲学雑誌], No. 313, No. 314 and No. 315, March–May 1913), reprinted in CW14:114-139.
‘Natorp’s Criticisms of the Principle of Relativity’ [相対性原理に対するナトルプ氏の批評] (Tetsugaku Zasshi [哲学雑誌], No. 318, August 1913), reprinted in CW14:140-152.
‘The Significance of Descriptions in the Epistemology of Physics: A Critique of Kirchhoff and Mach’ [物理学的認識に於ける記載の意義——キルヒホッフ及びマッハの批評] (Tetsugaku Zasshi [哲学雑誌], No. 319, September 1913), reprinted in CW1:11-26.
On the descriptivism of Kirchhoff and Mach.
‘Critical Notice of Henri Poincaré’s ‘L'espace et le temps’’ [ポアンカレ氏『空間と時間』] (Tetsugaku Zasshi [哲学雑誌], No. 322, December 1913), reprinted in CW14:153-164.
1914
‘The Limits of Logicism in Epistemology: A Critique of the Marburg and Freiburg Schools’ [認識論に於ける論理主義の限界——マールブルヒ派とフライブルヒ派の批評] (Tetsugaku Zasshi [哲学雑誌], No. 324 and No. 325, February-March 1914), reprinted in CW1:27-61.
‘On Kuwaki’s Essay on the Method of Physics’ [桑木理学士の物理学の方法に関する一論文] (Tetsugaku Zasshi [哲学雑誌], No. 325, March 1914), reprinted in CW14:165-168.
‘On the Existence of Mathematical Objects: Reading Medicus’ Essay’ [数学的対象の存在について——メディクスの論文を読む] (Tetsugaku Zasshi [哲学雑誌], No. 331, September 1914), reprinted in CW14:169-192.
The essay in question is Fritz Medicus, ‘Bemerkungen zum Problem der Existenz mathematischer Gegenstände’, Kant-Studien, 19:1-19.
1915
‘The Natural Sciences versus the Social and Cultural Sciences’ [自然科学対精神科学・文化科学] (Shinri Kenkyū [心理研究], No. 38, No. 39 and No. 40, February–April 1915), reprinted in CW1:63-93.
‘A Theory of Natural Numbers’ [自然数論] (Tetsugaku Zasshi [哲学雑誌], No. 337 and No. 338, March-April 1915), revised and reprinted in Investigations into the Philosophy of Mathematics.
Modern Natural Science [最近の自然科学] (Iwanami Shoten [岩波書店], November 1915), reprinted in CW2:1-153.
‘Preface to the Third Printing of Modern Natural Science’ [『最近の自然科学』第三版の序] (Iwanami Shoten [岩波書店], December 1915), reprinted in CW14:193.
1916
‘Continuity, Derivative, Infinity’ [連続、微分、無限] (Tetsugaku Zasshi [哲学雑誌], No. 348, No. 349 and No. 351, February-May 1916), revised and reprinted in Investigations into the Philosophy of Mathematics.
‘On Universals’ [普遍に就いて] (Tetsugaku Kenkyū [哲学研究], No. 5, May 1916), reprinted in CW1:95-117.
‘Translator’s Preface to Poincaré, La valeur de la science’ [ポアンカレ『科学の価値』訳者序] (Iwanami Shoten [岩波書店], May 1916), reprinted in CW14:194-195.
‘Negative Numbers and Imaginary Numbers’ [負数及び虚数] (Tetsugaku Zasshi [哲学雑誌], No. 358 and No. 359, December 1916-January 1917), revised and reprinted in Investigations into the Philosophy of Mathematics.
1917
‘The Epistemology of Mathematics’ [数理の認識] (Tetsugaku Kenkyū [哲学研究], No. 13, April 1917), revised and reprinted in Investigations into the Philosophy of Mathematics.
‘Variables and Functions’ [変数及び函数] (Tetsugaku Zasshi [哲学雑誌], No. 363 and No. 364, May-June 1917), revised and reprinted in Investigations into the Philosophy of Mathematics.
‘Moral Freedom’ [道徳的自由] (Shichō [思潮], Vol. 1, No. 3 and No. 4, July–August 1917), reprinted in CW1:119-139.
‘The Theory of Time’ [時間論] (Tetsugaku Kenkyū [哲学研究], No. 17, August 1917), reprinted in CW1:141-171.
1918
‘The Logical Foundations of Geometry’ [幾何学の論理的基礎] (Tetsugaku Zasshi [哲学雑誌], No. 371, No. 372 and No. 373, January-March 1918), revised and reprinted in Investigations into the Philosophy of Mathematics.
‘The Problem of Philosophical Knowledge in German Idealism’ [ドイツ唯心論に於ける哲学的認識の問題] (Tetsugaku Kenkyū [哲学研究], No. 23 and No. 24, February–March 1918), reprinted in CW1:173-226.
‘Reading Dr. Sōda’s Problems in the Philosophy of Economics’ [左右田博士の著『経済哲学の諸問題』を読む] (Tetsugaku Kenkyū [哲学研究], No. 26, May 1918), reprinted in CW14:196-202.
‘The World of Infinity’ [無限の世界] (Shichō [思潮], Vol. 2, No. 5, August 1918), reprinted in CW1:227-234.
‘A Request to Dr. Sōda’s for Clarification regarding the Logic of Individual Causality’ [個別的因果律の論理に就きて左右田博士の教えを乞ふ] (Tetsugaku Kenkyū [哲学研究], No. 30, September 1918), reprinted in CW1:235-244.
Sōda replied with his ‘Awaiting Further Clarification from Dr. Tanabe regarding the Logic of Individual Causality’ [個別的因果律に関して更に田辺博士の教えを俟つ] (Tetsugaku Kenkyū [哲学研究], No. 32, November 1918).
Philosophy of Science [科学概論] (Iwanami Shoten [岩波書店], September 1918), reprinted in CW2:155-360.
‘On Kant’s Theory of Freedom’ [カントの自由論に就いて] (Shichō [思潮], Vol. 2, No. 9, October 1918), reprinted in CW1:245-253.
‘The Significance of Leibniz’s Philosophy [ライプニッツ哲学の意義] (Tetsugaku Kenkyū [哲学研究], No. 32, November 1918), reprinted in CW1:255-284.
‘Lecture on Idealism’ [理想主義] (1918), reprinted in CW15:3-34.
1919
‘The Meaning of the Word ‘Truth’’ [眞といふ語の意味] (Shichō [思潮], Vol. 3, January 1919), reprinted in CW1:285-295.
‘Araragi's Tradition’ [アララギの伝統] (Araragi [アララギ], January 1919), reprinted in CW14:317-320.
‘On Consciousness as Such’ [「意識一般」に就て] (Tetsugaku Zasshi [哲学雑誌], No. 387, May 1919), reprinted in CW1:297-323.
On Kant’s notion of »Bewußtsein überhaupt«.
‘A Remark on Passages Quoted in Kihira’s Essay’ [紀平学士論文中の引用句に就き一言す] (Tetsugaku Zasshi [哲学雑誌], No. 391, September 1919), reprinted in CW14:203-204.
‘The Problem of the Subject of Knowledge’ [認識主観の問題] (Tetsugaku Kenkyū [哲学研究], No. 44, No. 47, No. 59, No. 63 and No. 68, November 1919-November 1921), reprinted in CW1:325-412.
1920
‘The Natural Sciences and the Social Sciences’ [自然科学と文化科学] (Shinano Kyōiku [信濃教育], February-March 1920), reprinted in CW14:253-83.
‘An Amateur's Opinion’ [素人の感想] (Araragi [アララギ], May 1920), reprinted in CW14:321-325.
1921
‘Tanka’ [短歌] (Araragi [アララギ], January-March, June-July, September 1921), reprinted in CW14:326-332.
‘Reading Shimaki Akahiko’s Hio’ [『永魚』を読む] (Araragi [アララギ], March 1921), reprinted in CW14:333-342.
1922
‘On Historical Knowledge’ [歴史の認識に就いて] (Shirin [史林], Vol. 7, No. 1, January 1922), reprinted in CW1:413-422.
‘The Concept of Culture’ [文化の概念] (Kaizō [改造], March 1922), reprinted in CW1:423-447.
‘The Infinite Continuity of Existence’ [実在の無限連続性] (Shisō [思想], No. 6, March 1922), reprinted in CW1:449-472.
Entries in The Iwanami Dictionary of Philosophy [岩波哲学辞典] (Iwanami Shoten [岩波書店], October 1922), reprinted in CW15:419-67.
Archimedes’ axiom [アルキメデス公理]; Körper α [アルファ体]; Analysis situs [位置解析]; Ether [エーテル]; Energetic view of nature [エネルギー観]; Principle of conservation of energy [エネルギー保存則]; Action at a distance [遠隔作用]; Entropy [エントロピー]; Extensive quality [外延量]; Analysis [解析]; Analytical geometry [解析幾何学]; Critique of science [科学批判]; Reversible phenomenon [可逆現象]; Function [関数]; Mechanical view of nature [機械観]; Geometry [幾何学]; Pseudo-spherical space [擬球面空間]; Description [記述]; Descriptive school [記述学派]; Cardinal number [基数]; Series [級数]; Spherical space [球面空間]; Limit [極限]; Grenzpunkt [極限点]; Method of limit [極限法]; Grenzelement [極限要素]; Ortzeit [局所時]; Imaginary number [虚数]; Modern geometry [近世幾何学]; Space curvature [空間曲率]; Contingency [偶然]; Group [群]; Principle of permanence of formal laws [形式不易の原理]; Metrical geometry [計量幾何学]; Atomic theory [原子論]; Ausdehnungslehre [広遠論]; Theory of probability [公算論]; Postulate [公準]; Axiom [公理]; Axiomatic [公理主義]; Coordinates [座標]; Theory of economy of thought [思惟経済説]; Dimension [次元]; Quaternions [四元法]; Self-representation system [自己表現体系]; Natural science [自然科学]; Naturwissenschaftlich [自然科学的]; Natural number [自然数]; Gedankenexperiment [思想実験]; Real number [実数]; Mass [質量]; Projection [射影]; Projective geometry [射影幾何学]; Ordinal number [序数]; Number [数]; Mathematics [数学]; Mathematical [数学的]; Mathematical induction [数学的帰納法]; Mathematical formalism [数学的形式主義]; Mathematical realism [数学的実在論]; Mathematical nominalism [数学的唯名論]; Realm/Corpus of numbers [数体]; Number continuum [数連続体]; Arithmetisation [数論化]; Welt [世界]; Integral [積分]; Integer [整数]; Absolute space [絶対空間]; Absolute time [絶対時間]; Schnitt [切断]; Explanation [説明]; Exact sciences [精密科学]; Prime number [素数]; Theory of quanta [素量説]; Algebraic number [代数的数]; Field of force [力の場]; Transcendental number [超越的数]; Transfinite aggregate [超限集合]; Transfinite number [超限数]; Electromagnetic view of nature [電磁観/電磁的自然観]; Set of points [点集合]; Electron theory [電子論]; Punktmannigfaltigkeit [点複素体]; Point transformation [点変換]; Statistical mechanics [統計的力学]; Homogeneity [等質性]; Isotropy [等方性]; Intensive quantity [内包量]; First law of thermodynamics [熱力学第一法則]; Second law of thermodynamics [熱力学第二法則]; Physical theory of light [光の物理学的理論]; Differential [微分]; Differential coefficient [微分係数]; Infinitesimal method [微分法]; Differential equation [微分方程式]; Non-Euclidean geometry [非ユークリッド幾何学]; To represent [表現する]; Irreversible phenomenon [不可逆現象]; Complex number [複素数]; Negative number [負数]; Principle of conservation of matter [物質保存の原理]; Fourth state of matter [物質の第四態]; Disintegration of matter [物質変脱]; Physics [物理学]; Physical [物理的]; Invariant [不変式]; Mathesis universalis [普遍数学]; Fraction [分数]; Transformation [変換]; Variable [変数]; Parabolic space [放物線空間]; Elements at infinity [無窮遠要素]; Infinity [無限]; Irrational number [無理数]; Euclidean geometry [ユークリッド幾何学]; Rational number [有理数]; Dynamics/Mechanics [力学]; Riemann-Helmholtz geometry [リーマン・ヘルムホルツ幾何学]; Fluxion [流率]; Quantity [量]; Continuity [連続]; Lobachevsky-Bolyai geometry [ロバチェフスキィ・ボリヤイ幾何学]; Logistic/Algebra of logic [論理計算]; Vector analysis [ヴェクトル解析]
1924
‘Letter from Paris’ [巴里より] (Araragi [アララギ], January 1924), reprinted in CW14:343.
‘The Relationship Between Intuition and Thought in the Transcendental Deduction’ [先験演繹論に於ける直観と思惟との関係] (Shisō [思想], No. 30, April 1924), reprinted in CW4:1-16.
‘Kant’s Teleology’ [カントの目的論] (Tetsugaku Kenkyū [哲学研究], No. 99, No. 100 and No. 101, June-August 1924), revised and reprinted in Kant’s Teleology, CW3:1-72.
‘A New Turn in Phenomenology: Heidegger’s Phenomenology of Life’ [現象学に於ける新しき転向——ハイデッガーの生の現象学] (Shisō [思想], No. 36, October 1924), reprinted in CW4:17-34.
Kant’s Teleology [カントの目的論] (Iwanami Shoten [岩波書店], October 1924), reprinted in CW3:1-72.
‘Reading Shimaki Akahiko’s Kadō Shōken’ [『歌道小見』を読む] (Araragi [アララギ], October 1924), reprinted in CW14:344-350.
‘Lecture on the Development of Phenomenology’ [現象学の発展] (1924-25), reprinted in CW15:35-153.
1925
‘Epistemology and Phenomenology’ [認識論と現象学] (Kōza [講座], No. 24 and No. 25, January–February 1925), reprinted in CW4:35-71.
‘Intuitive Knowledge and the Thing in Itself’ [直観知と物自体] (Tetsugaku Kenkyū [哲学研究], No. 109, No. 112 and No. 128, April 1925-November 1926), reprinted in CW4:73-139.
Intuitive knowledge as in Spinoza’s scientia intuitiva.
Investigations into the Philosophy of Mathematics [数理哲学研究] (Iwanami Shoten [岩波書店], May 1925), reprinted in CW2:361-661.
‘On Shimaki Akahiko’s Taikyoshū’ [『太虗集』に就いて] (Araragi [アララギ], August 1925), reprinted in CW14:351-353.
‘Lask’s Logic’ [ラスクの論理] (Shisō [思想], No. 48, October 1925), reprinted in CW4:141-160.
1926
‘Reminiscences of Shimaki Akahiko’ [憶出] ((Araragi [アララギ], October 1926), reprinted in CW14:354-356.
1927
‘On Circular Reasoning in the Critical Method’ [批判的方法に於ける循環論に就いて] (Shisō [思想], No. 64, February 1927), reprinted in CW4:207-229.
‘The Logic of the Dialectic’ [辯證法の論理] (Tetsugaku Kenkyū [哲学研究], No. 132, No. 134, No. 136, No. 146, No. 152 and No. 162, March 1927-September 1929), revised and reprinted in Hegel’s Philosophy and the Dialectic, CW3:234-369.
‘Reflection’ [反省作用] (in Festschrift for Tokunō Bun [得能博士還暦記念哲学論文集], Iwanami Shoten [岩波書店], April 1927), reprinted in CW4:161-205.
‘On the Concept of Sensation’ [感覚の概念に就いて] (Shinrigaku Kenkyū [心理学研究], Vol. 2, No. 3, June 1927) reprinted in CW4:231-239.
‘Translator’s Preface to Planck, ‘Die Einheit des physkalischen Weltbildes’’ [プランク『物理学的世界像の統一』訳者小引] (Iwanami Shoten [岩波書店], July 1927), reprinted in CW14:205-206.
‘Blurb for Tsuchida Kyōson’s Studies on Contemporary Japanese and Chinese Thought’ [土田杏村『日本支那現代思想研究』について] (in Studies on Contemporary Japanese and Chinese Thought [日本支那現代思想研究], revised edition, Dai Ichi Shobō [第一書房], October 1927), reprinted in CW14:357-358.
‘Reminiscences of Sōda Ki’ichirō’ [左右田さんの思出] (Shisō [思想], October 1927), reprinted in CW14:359-374.
1928
‘Knowledge of the Past in the Study of History’ [史学に於ける過去の認識] (Tetsugaku Kenkyū [哲学研究], No. 142, January 1928), reprinted in CW4:241-256.
‘The Role of Concepts in the Historical Knowledge’ [歴史の認識に於ける概念の機能] (Shirin [史林], Vol. 13, No. 2, April 1928), reprinted in CW4:257-269.
‘The Location of Evidence’ [明證の所在] (Tetsugaku Zasshi [哲学雑誌], No. 500, October 1928), reprinted in CW4:271-286.
‘On Confucian Ontology’ [儒教的存在論について] (in Festschrift for Takase Takejirō [高瀬博士還暦記念支那学論叢], Iwanami Shoten [岩波書店], December 1928), reprinted in CW4:287-301.
1929
‘Action and History and Their Relation to the Dialectic’ [行為と歴史、及び辯證法のこれに対する関係] (Shisō [思想], No. 89, October 1929), revised and reprinted in Hegel’s Philosophy and the Dialectic, CW3:211-233.
‘On Shimaki Akahiko’s Art’ [島木さんの藝術] (in a catalogue for The Collected Works of Shimaki Akahiko [島木赤彦全集], Iwanami Shoten, 1929), reprinted in CW14:375.
1930
‘On the So-Called Class Aspect of Science’ [所謂「科学の階級性」に就いて] (Kaizō [改造], Vol. 12, No. 1, January 1930), reprinted in CW14:207-221.
‘A Request to Professor Nishida for Clarification’ [西田先生の教えを仰ぐ] (Tetsugaku Kenkyū [哲学研究], No. 170, May 1930), reprinted in CW4:303-328.
Tanabe’s famous critique of Nishida’s philosophy.
‘The Subject of Morality and Dialectical Freedom’ [道徳の主体と辯證法的自由] (Shisō [思想], No. 100, September 1930), revised and reprinted in Hegel’s Philosophy and the Dialectic, CW3:195-210.
‘The Significance of the New Physics’ World Picture’ [新物理学的世界像の意義] (Iwanami Kōza: Butsurigaku Oyobi Kagaku [岩波講座 物理学及び化学], October 1930), reprinted in CW14:222-238.
1931
‘The Identity of the Rational and the Real in Hegel’ [ヘーゲルに於ける理性的と現実的の一致] in Hegel and Hegelianism [ヘーゲルとヘーゲル主義], Iwanami Shoten [岩波書店], February 1931, revised and reprinted in Hegel’s Philosophy and the Dialectic, CW3:173-194.
‘Synthesis and Transcendence’ [綜合と超越] (in Festschrift for Tomonaga Sanjūrō [朝永博士還暦記念哲学論文集], Iwanami Shoten [岩波書店], April 1931), reprinted in CW4:329-353.
‘The Standpoint of Anthropology’ [人間学の立場] (Risō [理想], No. 27, October 1931), reprinted in CW4:355-382.
‘Hegel’s Philosophy and the Absolute Dialectic’ [ヘーゲル哲学と絶対辯證法] (Shisō [思想], No. 113, November 1931), revised and reprinted in Hegel’s Philosophy and the Dialectic, CW3:152-172.
‘Hegel’s Absolute Idealism’ [ヘーゲルの絶対観念論] (Tetsugaku Kenkyū [哲学研究], No. 189, December 1931), revised and reprinted in Hegel’s Philosophy and the Dialectic, CW3:85-135.
‘Understanding Hegel’s Theory of Judgement’ [ヘーゲル判断論の理解] (Tetsugaku Zasshi [哲学雑誌], No. 538, December 1931), revised and reprinted in Hegel’s Philosophy and the Dialectic, CW3:136-151.
1932
Hegel’s Philosophy and the Dialectic [ヘーゲル哲学と辯證法] (Iwanami Shoten [岩波書店], January 1932), reprinted in CW3:73-369.
‘Dialectic of Individual Essence’ [個體的本質の辯證論] (in Spinoza and Hegel [スピノザとヘーゲル], Iwanami Shoten [岩波書店], July 1932), reprinted in CW4:383-415.
‘From the Time Schema to the World Schema’ [図式「時間」から図式「世界」へ] (Tetsugaku Kenkyū [哲学研究], No. 200, November 1932), reprinted in CW6:1-49.
‘Lecture on the Meaning of Dialectic’ [辯證法の意味] (1932-7), reprinted in CW15:155-234.
1933
‘The Way to Philosophy’ [哲学への通路] (Shisō [思想], No. 133, June 1933), reprinted in CW5:1-19.
‘Philosophy of Crisis or Crisis of Philosophy?’ [危機の哲学か哲学の危機か] (September 1933, unpublished), reprinted in CW8:1-9.
General Philosophy [哲学通論] (Iwanami Shoten [岩波書店], December 1933), reprinted in CW3:371-522.
1934
‘The Relationship Between Mathematics and Philosophy’ [数学と哲学との関係] (Iwanami Kōza: Sūgaku [岩波講座 数学], May 1934), reprinted in CW5:21-57.
‘Re-Examining the Foundations of Mathematics: On Konno’s Essay’ [数学の基礎再吟味——今野氏の論文に因みて] (Kagaku [科学], Vol. 4, No. 8, August 1934), reprinted in CW14:239-245.
‘The Relationship Between Religion and Culture: On the Debate Between Barth and Brunner’ [宗教と文化の関係——バルトとブルンナーの論争に因みて] (Shisō [思想], No. 149 October 1934), reprinted in CW5:59-80.
‘On Intellectual Thought Today’ [現下の思想に就て] (Kyōdai Shimbun [京大新聞], November 1934), reprinted in CW14:376-379.
‘Remembering Nakamura Kenkichi’ [中村氏を悼む] (Araragi [アララギ], November 1934), reprinted in CW14:380-382.
‘The Logic of Social Existence’ [社会存在の論理] (Tetsugaku Kenkyū [哲学研究], No. 224, No. 225 and No. 226, November 1934-January 1935), reprinted in CW6:51-167 and SPW1:9-186.
1935
‘Quo Vadis’ [クオ・ワヂス] (Bungei Shunjū [文藝春秋], April 1935), reprinted in CW14:383-385.
‘Letter to Saitō Mokichi’ [齋藤茂吉氏へ] (in an essay collection on Saitō’s Kakinomoto no Hitomaro [柿本人磨]), Iwanami Shoten, May 1935), reprinted in CW14:386-387.
‘The Uniqueness of Iwanami Shoten’s Kokugo’ [岩波『國語』の特色] (Kokugo Tokuhō 2 [國語特報2], October 1935), reprinted in CW14:388-390.
‘The Logic of Species and the World Schema’ [種の論理と世界図式] (Tetsugaku Kenkyū [哲学研究], No. 235, No. 236 and No. 237, October-December 1935), reprinted in CW6:169-264 and SPW1:187-333.
‘The Third Stage of Ontology’ [存在論の第三段階] (Risō [理想], No. 76, November 1935), reprinted in CW6:265-298.
1936
Entries in the Dictionary of Pedagogy [教育学辞典] (Iwanami Shoten [岩波書店], May 1936), reprinted in CW15:468-473.
Philosophy of mathematics [数理哲学]; Methodology [方法論]
‘Answer to the Questionnaire ‘What Do You Want the University’s Students to Read?’’ [アンケート「これは大学生に一讀させたし」に對して] (Kyōdai Shimbun [京大新聞], 20th September 1936), reprinted in CW14:391.
‘On Humanism’ [ヒューマニズムについて] (Shisō [思想], No. 173, October 1936), reprinted in CW5:81-92.
‘The Social Ontological Structure of Logic’ [論理の社会存在論的構造] (Tetsugaku Kenkyū [哲学研究], No. 247, No. 248 and No. 249, October-December 1936), reprinted in CW6:299-396.
‘The Development of Mathematics in the History of Thought’ [思想史的に見たる数学の発達] (in Mathematics as General Education [一般的教養としての数学について], Iwanami Shoten [岩波書店], November 1936), reprinted in CW5:93-140.
1937
The Two Sides to Natural Science Education [自然科学教育の両側面] (Monbushō [文部省], March 1937), reprinted in CW5:141-191.
‘Response to Minoda’s and Matsuda’s Criticisms’ [蓑田氏及び松田氏の批判に答ふ] (Genri Nippon [原理日本], May 1937), reprinted in CW8:11-31.
The Meaning of Historical Study [史学の意味] (Nippon Bunka Kyōkai Shuppanbu [日本文化協会出版部], August 1937), reprinted in CW8:33-91.
‘Response to Criticisms of the Logic of Species’ [種の論理に対する批評に答ふ] (Shisō [思想], No. 185, October 1937), reprinted in CW6:397-445.
‘Clarification of the Meaning of the Logic of Species’ [種の論理の意味を明にす] (Tetsugaku Kenkyū [哲学研究], No. 259, No. 260 and No. 261, October-December 1937), reprinted in CW6:447-521 and SPW1:335-448.
1938
Science as Morality [徳性としての科学] (Tokyo: Sūgakukyoku [数学局], August 1938), reprinted in CW5:329-83.
‘Logic from Kant to Hegel’ [カントからヘーゲルへの論理] (in Festschrift for Hatano Sei’ichi [波多野精一先生献呈論文集], Iwanami Shoten [岩波書店], September 1938), reprinted in CW5:385-404.
‘The Expansion of Scientism’ [科学主義の拡充] (September 1938, unpublished), reprinted in CW8:93-103.
‘The Limits of Existentialist Philosophy’ [実存哲学の限界] (Tetsugaku Zasshi [哲学雑誌], No. 620, October 1938), reprinted in CW7:1-24.
‘My View on the Principle Underlying the Direction of Japan’s Cultural Policy Towards China’ [対支文化政策の指導原理に関する私見] (November-December 1938, unpublished), reprinted in CW8:105-116.
1939
‘On Scientific Thinking’ [科学思想について] (in Keisatsu Kanbu Yokuonkan Kōwaroku [警察幹部浴恩館講話録], May 1939), reprinted in CW14:284-314.
My View of the Philosophy of Shōbōgenzō [正法眼蔵の哲学私観] (Iwanami Shoten [岩波書店], May 1939), reprinted in CW5:443-494.
‘Physics and Philosophy’ [物理学と哲学] (Iwanami Kōza: Butsurigaku [岩波講座 物理学], October 1939), reprinted in CW5:405-441.
‘The Logic of National Existence’ [国家的存在の論理] (Tetsugaku Kenkyū [哲学研究], No. 283, No. 284 and No. 285, October-December 1939), reprinted in CW7:25-99.
Between Philosophy and Science [哲学と科学の間] (Iwanami Shoten [岩波書店], November 1939), reprinted in CW5:193-327.
1940
Historical Reality [歴史的現実] (Iwanami Shoten [岩波書店], June 1940), reprinted in CW8:117-169.
‘Eternity, History, Action’ [永遠・歷史・行為] (Tetsugaku Kenkyū [哲学研究], No. 295, https://doi.org/10.14989/JPS_25_11_909 No. 296] and No. 297, October-December 1940), reprinted in CW7:101-170.
‘Ethics and Logic’ [倫理と論理] (Iwanami Kōza: Rinrigaku [岩波講座 倫理学], Vol. 4, November 1940), reprinted in CW7:171-209.
1941
The Direction of Philosophy [哲学の方向] (Meguro Shoten [目黒書店], April 1941), reprinted in CW8:171-199.
‘The Morality of the State’ [国家の道義性] (Chūō Kōron [中央公論], October 1941), reprinted in CW8:201-219.
‘The Way of Patriotic Thinking’ [思想報国の道] (Kaizō [改造], October 1941), reprinted in CW8:221-241.
‘The Development of the Concept of Existence’ [実存概念の発展] (Tetsugaku Kenkyū [哲学研究], No. 307 and No. 309, October and December 1941), reprinted in CW7:211-251.
Dialectic of the Logic of Species [種の論理の辯證法] (Akitaya [秋田屋], November 1947), reprinted in CW7:251-372.
1942
‘Lecture on Philosophy’ [哲学について] (1942), reprinted in CW15:235-247.
1943
‘Life and Death’ [死生] (May 1943, speech), reprinted in CW8:243-262.
1944
‘The Limits of Culture’ [文化の限界] (February 1944, speech), reprinted in CW8:263-305.
‘A Way to Repentance: Metanoetics’ [懺悔道——Metanoetik] (October 1944, first published in Kyūshin [求真], No. 15, 2008) and SPW2:11-31.
1945
‘Inayaga Shōkichi, The Foundational Concepts of Modern Mathematics, Vol. 1’ [彌永昌吉『現代数学基礎概念（上）』] (Kagaku [科学], Vol. 15, No. 2, October 1945), reprinted in CW14:246-249
1946
‘The Establishment of Democracy in Japan’ [日本民主主義の確立] (Chōryū [潮流], January 1946), reprinted in CW8:307-322.
Philosophy as a Way to Repentance: Metanoetics [懺悔道としての哲学] (Iwanami Shoten [岩波書店], April 1946), reprinted in CW9:1-269 and SPW2:33-439.
Urgent Matters for Political Philosophy [政治哲学の急務] (Chikuma Shobō [筑摩書房], June 1946), reprinted in CW8:323-395.
‘The Standpoint of the Absolute Nothing and the Materialist Dialectic’ [絶対無の立場と唯物辯證法——森宏一氏に答ふ] (Shinzenbi [真善美], August 1946), reprinted in CW8:397-409.
‘Lecture on Philosophical Thinking’ [哲学的思考] (1946), reprinted in CW15:249-286.
1947
‘The Present Task of the Intellectual Classes’ [知識階級現在の任務] (Chōryū [潮流], January 1947), reprinted in CW8:411-441.
‘Christianity, Marxism and Japanese Buddhism: Predictions for the Second Reformation’ [キリスト教とマルクシズムと日本仏教——第二次宗教改革の予想] (Tenbō [展望], No. 21, September 1947), reprinted in CW10:271-324.
Dialectic of the Logic of Species [種の論理の辯證法] (Akitaya [秋田屋], November 1947), reprinted in CW7:251-372.
Existence, Love and Practice [実存と愛と実践] (Chikuma Shobō [筑摩書房], December 1947), reprinted in CW9:271-492.
1948
‘A Theoretical Solution to Class Warfare’ [階級戦の理論的突破] (March 1948, unpublished), reprinted in CW8:443-462.
Dialectic of Christianity [キリスト教の辯證] (Chikuma Shobō [筑摩書房], June 1948), reprinted in CW10:1-269.
‘Localised and Microscopic: Characteristics of Contemporary Thought’ [局所的微視的——現代的思考の特徴] (Tenbō [展望], No. 35, November 1948), reprinted in CW12:3-58.
1949
Introduction to Philosophy: The Fundamental Problems of Philosophy [哲学入門——哲学の根本問題] (Chikuma Shobō [筑摩書房], March 1949), reprinted in CW11:1-132 and SPW3:11-216.
‘Dialectic of Classical Mechanics’ [古典力学の弁証法] (Kiso Kagaku [基礎科学], No. 2, April 1949), reprinted in CW12:59-131
The Fundamental Problems of Philosophy, Appendix 1: Philosophy of History and Political Philosophy [哲学の根本問題補説第一——歴史哲学・政治哲学] (Chikuma Shobō [筑摩書房], September 1949), reprinted in CW11:133-282.
1950
‘Science, Philosophy and Religion’ [科学と哲学と宗教] (Chikuma Shobō Tetsugaku Kōza [筑摩書房 哲学講座], Vol. 4, March 1950), reprinted in CW12:132-207.
The Fundamental Problems of Philosophy, Appendix 2: Philosophy of Science and Epistemology [哲学の根本問題補説第二——科学哲学・認識論] (Chikuma Shobō, April 1950), reprinted in CW11:283-425.
1951
Valéry’s Aesthetics [ヴァレリイの芸術哲学] (Chikuma Shobō [筑摩書房], March 1951), reprinted in CW13:1-162.
1952
Fundamental Problems of Philosophy, Appendix 3: Philosophy of Religion and Ethics [哲学の根本問題補説第三——宗教哲学・倫理学] (Chikuma Shobō [筑摩書房], April 1952), reprinted in CW11:427-632.
1953
‘Special Lecture at Kita-Karuizawa [北軽井沢特別講義] (May 1-3 and October 1-3, 1953), reprinted in CW15:287-417.
‘Philosophy, Poetry and Religion: Heidegger, Rilke, Hölderlin’ [哲学と詩と宗教——ハイデッガー・リルケ・ヘルダーリン] (begun in 1953, unfinished), reprinted in CW13:305-524.
1954
A Historicist Further Development of Mathematics: A Memorandum on the Foundations of Mathematics [数理の歴史主義展開——数学基礎論覚書] (Chikuma Shobō [筑摩書房], November 1954), reprinted in CW12:209-334.
1955
‘Oskar Becker, Die Grundlagen der Mathematik in geschichtlicher Entwicklung’ [オスカー・ベッカー教授の『数学基礎発展史』] (Kagaku Kisoron Kenkyū [科学基礎論研究], Vol. 1, No. 3, March 1955), reprinted in CW14:250-252.
Proposition of a New Methodology for Theoretical Physics: The Necessity of Theory of Functions of Complex Variables qua Method of Theoretical Physics and Its Topological Character [理論物理学新方法論提説——理論物理学の方法としての複素変数関数論の必然性とその位相学的性格] (Chikuma Shobō [筑摩書房], May 1955), reprinted in CW12:335-368.
Dialectic of the Theory of Relativity [相対性理論の弁証法] (Chikuma Shobō [筑摩書房], October 1955), reprinted in CW12:369-402.
1958
‘Memento Mori’ [メメント・モリ] (Shinano Kyōiku [信濃教育], No. 858, May 1958), reprinted in CW13:163-175 and SPW4:11-29.
1960
‘My Interpretation of the Chan Preface’ [禅源私解] (in Festschrift for D. T. Suzuki [鈴木大拙博士記念論文集], Suzuki Gakujutsu Zaidan [鈴木学術財団], October 1960), reprinted in CW13:177-198 and SPW4:31-62.
1961
A Memorandum on Mallarmé [マラルメ覚書] (Chikuma Shobō [筑摩書房], August 1961), reprinted in CW13:199-304 and SPW4:63-218.
1962
‘Ontology of Life or Dialectic of Death?’ [生の存在学か死の弁証法か] (Tetsugaku Kenkyū [哲学研究], No. 483, November 1962), reprinted in CW13:525-576 and SPW4:219-295.
English translations
Early Works (1910–1919)
"The Logic of the Species as Dialectics," trans. David Dilworth and Taira Sato, in Monumenta Nipponica, Vol. 24, No. 3 (1969): 273–88.
"Kant's Theory of Freedom," trans. Takeshi Morisato with Cody Staton in "An Essay on Kant’s Theory of Freedom from the Early Works of Tanabe Hajime" in Comparative and Continental Philosophy, vol. 5 (2013): 150–156.
"On the Universal," trans. Takeshi Morisato with Timothy Burns, in "Groundwork for the Metaphysics of Deductive Reasoning: The Relation of the Universal and the Particular in Early Works of Tanabe Hajime" in Comparative and Continental Philosophy, vol. 5 (2013): 124–149.
Middle Work (1920–1930)
"Requesting the Guidance of Professor Nishida," trans., Richard Stone and Takeshi Morisato, Asian philosophical Texts: Exploring Hidden Sources, eds., Roman Pasca and Takeshi Morisato, 281–308. Milan: Mimesis, 2020.
Logic of Species (1931–1945)
(Forthcoming) "The Social Ontological Structure of the Logic," Tanabe Hajime and the Kyoto School: Self, World, and Knowledge. London: Bloomsbury, 2021.
Later Works (1946–1962)
Philosophy as Metanoetics, trans. Takeuchi Yoshinori, Valdo Viglielmo, and James W. Heisig, University of California Press, 1987.
"Demonstration of Christianity", in Introduction to the philosophy of Tanabe: According to the English translation of the seventh chapter of the demonstratio of Christianity, trans. Makoto Ozaki, Rodopi Bv Editions, 1990.
Secondary sources
Books and theses
Adams, Robert William, "The feasibility of the philosophical in early Taishô Japan: Nishida Kitarô and Tanabe Hajime." PhD diss., University of Chicago, 1991.
Dilworth, David A. and Valdo H. Viglielmo (translators and editors); with Agustin Jacinto Zavala, Sourcebook for modern Japanese philosophy : selected documents, Westport, Conn. : Greenwood Press, 1998.
Fredericks, James L., "Alterity in the thought of Tanabe Hajime and Karl Rahner." PhD diss., University of Chicago, 1988.
Heisig, James W., Philosophers of Nothingness: An Essay on the Kyoto School, Nanzan Library of Asian Religion and Culture, University of Hawaii Press, 2002.
Morisato, Takeshi, Faith and Reason in Continental and Japanese Philosophy: Reading Tanabe Hajime and William Desmond, London: Bloomsbury, 2019.
Ozaki, Makoto, Individuum, Society, Humankind: The Triadic Logic of Species According to Hajime Tanabe (Brill's Japanese Studies Library), Brill Academic Publishers (April 2001), , .
Pattison, George, Agnosis: Theology in the Void, Palgrave Macmillan (February 1997), . .
Unno, Taitetsu, and James W. Heisig (Editor), The Religious Philosophy of Tanabe Hajime: The Metanoetic Imperative (Nanzan Studies in Religion and Culture), Asian Humanities Press (June 1990), , .
Articles
Cestari, Matteo, "Between Emptiness and Absolute Nothingness: Reflections on Negation in Nishida and Buddhism."
Ruiz, F. Perez, "Philosophy in Present-day Japan," in Monumenta Nipponica Vol. 24, No. 1/2 (1969), pp. 137–168.
Heisig, James W., "Tanabe's Logic of the Specific and the Critique of the Global Village," in Eastern Buddhist, Autumn95, Vol. 28 Issue 2, p198.
Sakai, Naoki, "SUBJECT AND SUBSTRATUM : ON JAPANESE IMPERIAL NATIONALISM," in Cultural Studies; Jul2000, Vol. 14 Issue 3/4, p462-530 (AN 4052788)
Viglielmo, V. H., "An Introduction to Tanabe Hajime's Existence, Love, and Praxis" in Wandel zwischen den Welten: Festschrift für Johannes Laube, (Peter Lang, 2003) pp. 781–797.
Waldenfels, Hans, "Absolute Nothingness. Preliminary Considerations on a Central Notion in the Philosophy of Nishida Kitaro and the Kyoto School," in Monumenta Nipponica, Vol. 21, No. 3/4 (1966), 354–391.
Williams, David, "In defence of the Kyoto School: reflections on philosophy, the Pacific War and the making of a post-White world," in Japan Forum, Sep2000, Vol. 12 Issue 2, 143–156.
Online links
Bracken, Joseph, "Absolute Nothingness and The Divine Matrix"
Buri, Fritz, "Hajime Tanabe, Philosophy of repentance and Dialectic of Death," in The Buddha-Christ as the Lord of the True Self: The Religious Philosophy of the Kyoto School, trns. by Harold H. Oliver, Mercer University Press, 1997, pp. 65–94. [via Google Books]
Driscoll, Mark, "Apoco-elliptic Thought in Modern Japanese Philosophy"
Hajime, Tanabe, Jitsuzon to ai to jissen (Existence, Love, and Praxis) [1947], (from vol. 9, Complete Works of Tanabe Hajime), Tokyo, Chikuma Shobô, 1963. A partial translation by V. H. Viglielmo , for which the Preface, Chapter One, and translator's introductory essay are published in “An Introduction to Tanabe Hajime’s Existence, Love, and Praxis." in Wandel zwischen den Welten: Festschrift für Johannes Laube, Peter Lang, 2003.
Mierzejewska, Anna, "The Buddhist Inspiration of The Concept of Faith in The Philosophy of Hajime Tanabe," in SILVA IAPONICARUM, FASC. VI・第六号, WINTER ・冬 2005, pp. 18–37.
Odin, Steve, "Hajime Tanabe," in The Social Self in Zen and American Pragmatism, pp. 114–117.
Ozaki, Makoto, "On Tanabe's Logic of Species," in ΠΑΔΕΙΑ: Comparative Philosophy.
Takahane, Yosuke, "Absolute Nothingness and Metanoetics,".
Wattles, Jeffrey, "Dialectic and Religious Experience in Tanabe Hajime's Philosophy as Metanoetics"
———. Philosophy and Spiritual Experience: The case of a Japanese Shin Buddhist
Yata, Ryosho. "An Examination of the Historical Development of the Concept of Two Aspects of Deep Belief, Part 1".
References
1889 births
1962 deaths
Japanese scholars of Buddhism
Ontologists
Phenomenologists
Philosophers of mathematics
Philosophers of science
20th-century Japanese philosophers
People in interfaith dialogue
Existentialists
Buddhist existentialists
Academic staff of Kyoto University
Kyoto University alumni
Recipients of the Order of Culture
Academic staff of Tohoku University
Kyoto School
Heidegger scholars | Hajime Tanabe | [
"Mathematics"
] | 15,696 | [
"Philosophers of mathematics"
] |
8,624,486 | https://en.wikipedia.org/wiki/T-Square%20%28software%29 | T-Square is an early drafting program written by Peter Samson assisted by Alan Kotok and possibly Robert A. Saunders while they were students at the Massachusetts Institute of Technology and members of the Tech Model Railroad Club.
T-Square was written for the PDP-1 computer and its Type 30 precision CRT that Digital Equipment Corporation donated to MIT in 1961. It is unlikely that many people have had the opportunity to use T-Square although Samson has said the group drew some schematics.
Authors
Students of Jack Dennis and John McCarthy discovered a stunning array of uses for the very expensive room-sized computers that were given to MIT. They were privileged to be enrolled when the school's first programming courses were taught.
They negotiated with their advisors and the operations manager John McKenzie for time and became single-users long before personal computers were available. About 1959 or 1960, some of this group of students became support staff and wrote software for about $1.75 USD per hour. They wrote the programming software which is used to build application software. Later Samson and Kotok became architects of DEC computers.
CAD
During this period Samson created other "firsts" in application software for music, games and page layout so it is perhaps not surprising he wrote what may be the first drafting program. Based on this experience, later in life Samson worked on an electronic drafting program with 80,000 lines of code. He received a patent in virtual reality at Autodesk, a vendor of CAD and CAM software.
Input device
To move the cursor, T-Square used a Spacewar! game controller built by Kotok and Saunders in 1962. It is not known if Saunders was involved in repurposing it for T-Square. Kotok, who was about 20 years old, did participate. He was known for doing what needed to be done and for taking an interest in "all things ingenious or intriguing."
The Spacewar! control boxes were cobbled together with wood, Bakelite and toggle switches. Although they are often considered to be the first joysticks, Kotok did not accept credit for coinventing them with Saunders.
Influence
T-Square is a small part of the reason people use today's computers for drafting, architecture, drawing and illustration and engineering. Prior to this revolution and in some places to this day, draftsmen and women used triangles, wood or metal T-squares, pencils and technical pens on film and paper. The beginning of this change can be seen in a video of Sutherland demonstrating Sketchpad.
In his 1963 MIT Ph.D. thesis, Sutherland explains he completed an early version that could draw parallel and perpendicular lines in November 1961. He goes on to say, "Somewhat before my first effort was working, Welden Clark of Bolt, Beranek and Newman..." showed him a "similar program" running on a PDP-1. T-Square and Sketchpad were developed in the same location a year or two apart but their influence on each other is unknown.
See also
Sketchpad
T-square
Notes
References
Also available at Google Video:
Computer-aided design software
Technical drawing
History of software | T-Square (software) | [
"Technology",
"Engineering"
] | 639 | [
"Design engineering",
"Civil engineering",
"History of software",
"Technical drawing",
"History of computing"
] |
8,624,576 | https://en.wikipedia.org/wiki/Public%20transport%20timetable | A public transport timetable (also timetable and North American English schedule) is a document setting out information on public transport service times. Both public timetables to assist passengers with planning a trip and internal timetables to inform employees exist. Typically, the timetable will list the times when a service is scheduled to arrive at and depart from specified locations. It may show all movements at a particular location or all movements on a particular route or for a particular stop. Traditionally this information was provided in printed form, for example as a leaflet or poster. It is now also often available in a variety of electronic formats.
In the 2000s, public transport route planners / intermodal journey planners have proliferated and offer traveller the convenience that the computer program looks at all timetables so the traveller doesn't need to.
A "timetable" may also refer to the same information in abstract form, not specifically published, e.g. "A new timetable has been introduced".
History
The first compilation of railway timetables in the United Kingdom was produced in 1839 by George Bradshaw. Greater speeds and the need for more accurate timings led to the introduction of standard railway time in Great Western Railway timetables in 1840, when all their trains were scheduled to "London time", i.e. Greenwich Mean Time (GMT), which replaced solar time. Until railway time was introduced, local times for London, Birmingham, Bristol and Manchester could differ by as much as 16 to 20 minutes; in India and North America these differences could be 60 minutes or more.
The European Rail Timetable, a compendium of the schedules of major European railway services, has been in publication since 1873 (appearing monthly since 1883). Originally, and for most of its history, it was published by Thomas Cook & Son and included Thomas Cook or Cook's in its title. Although Thomas Cook Group plc ceased publication in 2013, the Thomas Cook European Rail Timetable was revived by a new company in early 2014 as simply the European Rail Timetable. From 1981 to 2010, Cook also produced a similar bi-monthly Overseas volume covering the rest of the world, and some of that content was moved into the European Timetable in 2011.
Representation
A timetable can be produced dynamically, on request, for a particular journey on a particular day around a particular time (see journey planner, below), or in a timetable that gives an overview of all services, in a particular category, and is valid for a specified period. The latter could take the form of a book, leaflet, billboard, or a (set of) computer file(s), and makes it much easier to find out, for example, whether a transport service at a particular time is offered every day at that time, and if not, on which days; with a journey planner one may have to check every day of the year separately for this.
Matrix format
Many timetables comprise tables with services shown in columns, and stations or stops on the rows of the table. There will often be separate tables for each direction of travel, and often separate (pairs of) tables for working days, weekends and holidays. Generally the times shown against each station or stop will be the departure time, except for the last stop of the service which will be the arrival time. The left hand column will list the stations in route order, and the other columns are arranged from left to right in chronological order.
If the service is scheduled to wait, both arrival and departure times might be shown on consecutive rows. If a slow service is overtaken by a fast service, the slow service will often occupy more than one column, to keep the times in order. There may be additional rows showing connecting services.
In most parts of the world times are shown using the 24-hour clock (although in the United States the 12-hour clock, with the addition of "am/A" or "pm/P" or with pm times in bold, is more often used). If services run at the same minutes past each hour for part of the day, the legend "and at the same minutes past each hour" or similar wording may be shown instead of individual timings.
Other information may be shown, often at the tops of the columns, such as day(s) of operation, validity of tickets for each service, whether seat reservations are required, the type of vehicle used (e.g. for heritage railways and airline timetables), the availability of on-board facilities such as refreshments, availability of classes, and a service number. Timetables with services arranged in rows of tables and stops or stations in columns are less common but otherwise similar to timetables with services in columns.
Stop-specific displays
Some timetables, particularly at railway stations and bus stops, list the times that services depart from that location, sometimes with other information such as destinations, types (train), and stopping conditions. Again, there may be separate lists for different days of the week. There may be a separate list for each line/direction, or a combined chronological list (as in the picture). In parts of mainland Europe train departures are listed on a yellow poster, and arrivals on a white poster. These posters are placed at entrances to stations and on platforms.
Electronic displays
Dynamic electronic displays in stations may be at a central place and list the next few departures for each line, or all departures in the next hour. Displays on platforms usually just show the next departure (or perhaps the next few) from that platform.
Formats
Timetables may be printed as books, booklets, folded or plain cards or paper, posters, or hand-written on posters or blackboards, shown on back-lit displays, or published on-line or as SMS or text messages.
With the development of the internet and electronic systems, conventional thick paper timetables are gradually being replaced by website searching or CD-ROM style timetables, and the publication of comprehensive printed timetables is generally decreasing.
Transport schedule data itself is increasingly being made available to the public digitally, as specified in the General Transit Feed Specification (GTFS) format.
Scheduling
In many modern public transport systems, timetables and rostering are generated by computer, with the operators specifying the required operating span, minimum frequencies, route length/time and other such factors. Design of the schedule may aim to make times memorable for passengers, through the use of clock-face scheduling — services departing at regular intervals, at the same times every hour. This is less likely to apply at peak times, when the priority is optimum utilisation of available vehicles and staff.
Headway services
In large cities services may be so frequent that consulting a timetable is unnecessary. In some cases public transport operators do not publish public timetables for busy times of day, or they may simply state "services run every 3–5 minutes" (or words to that effect), which is the norm for buses in some cities such as Hong Kong even during off-peak hours.
Gallery
International timetables
European Rail Timetable, formerly titled Thomas Cook European Timetable
A monthly timetable book of major trains, some bus and ferry services in Europe.
Thomas Cook Overseas Timetable
A bi-monthly timetable book of major trains, and some bus and ferry services outside Europe, ceased December 2010.
OAG Flight Guide
A monthly air timetable book published by OAG (Official Airline Guide), and covers all airlines and airports in the world.
National timetables
America
United States
Amtrak System Timetable
The official timetable book, published twice a year.
Asia
China
China Railway Passenger Train Timetable (全国铁路旅客列车时刻表)
China Railway Passenger Express Train Timetable (全国铁路旅客快车时刻表)
Published twice a year by China Railway Publishing, in Chinese. The former timetable includes all trains, the latter fast express trains only.
Chinese Railway Timetable
Published irregularly (last January 2015) by Duncan Peattie, in English. It includes all trains shown in the Chinese Railway Passenger Train Timetable, but not all stations.
India
Trains at a Glance
Published once a year in English and Hindi.
Japan
The first regularly published appeared in 1894, published by a private company. By the time of the nationalization of Japanese railways in 1906, three competing timetables were being published and it was decided that only one official timetable should be offered to the public. Five thousand copies of the first official timetable were published in January 1915.
In 2010, two printed national timetables were available; one published by JTB Corporation and one published by the Transportation News Company/Kotsu Shimbunsha, itself owned by all constituent companies of the Japan Railways Group (barring the RTRI) and SoftBank. These thick books - the February 2009 edition of the JTB timetable, for example, contains 1152 pages - are published every month and cover all stations and trains of JR and private railways, as well as long-distance bus, ferry and air services. For frequent JR urban lines, subway trains, private railways and urban buses, only summary timetables are shown. In 2009, a book was published to mark the 1000th edition of the JTB timetable, containing reproductions of all one thousand covers, selected timetables and maps, and articles on the way the timetable is produced.
There are also many searchable online timetables covering all forms of transport, for example http://www.hyperdia.com/. Timetables for PDAs, mobile phones and PCs are readily available.
South Korea
Tourism Transport Timetable (월간 관광교통 시각표)
Published every month and covers all trains, highway bus, ferry and domestic air services.
Europe
Every year, in December and June, the European train timetables are amended. There are seldom major changes to important routes, but the change allows for alterations to international services and for seasonal variation. Currently the dates for the European train timetable changes are usually the Sunday of the second weekend in June and in December. In the months leading up to the changeover date booking will be restricted as some railway operators are sometimes late loading in the new data (between several weeks and a few days before the change).
However, in Switzerland timetable changes only happen once a year in December. In Switzerland major changes happen only in odd years.
One of the most comprehensive European-wide timetable information is provided by the electronic timetable search engine of German Railways Deutsche Bahn (information is also available in Danish, Dutch, French, Italian, Polish, Spanish and Turkish). The same information, but differently presented, one also find on the online timetables by the Swiss Federal Railways (in English, German, French, and Italian) and the timetable by the Czech Ministry of Transport (in Czech, and - however not to every detail - in English and German).
Germany
Ihr Reiseplan
This is a free timetable leaflet distributed in express train and has information about the departure, arrival time of the train and connecting services.
For many years the “Kursbuch Gesamtausgabe” ("complete timetable"), a very thick timetable book, was published but its contents are now available on the Deutsche Bahn website and CD ROM.
Italy
Pozzorario generale
Covers most trains.
Netherlands
Switzerland
In Switzerland, timetables change happens only once a year in December all over Switzerland for any kind of public transportation means; major changes even happens only every second year on odd years.
A large annual publication consisting of all Swiss railways, funiculairs, most lake and river boats, cableways, Swiss PostBus, and all other country buses timetables.
Official Timetable
Official Timetable of Switzerland in one multi-lingual edition, while the particular timetables themselves are kept in the language of the respectively covered Swiss area.
Information and Explanations (German, French, Italian,Rumantsch)
The printed version (three volumes; city transit networks (buses and tramways) are only referenced, but not included) has been cancelled from season 2017/18 onwards. Therefore, only the synoptic map of the first volume is up-to-date:
Volume 1 for railways/funiculairs, cableways, and boats: synoptic map
Volumes 2 and 3 for buses in western and eastern Switzerland: synoptic map (only last version of 2017)
Coherent, integrated online timetables
All online timetables provide information for the same timetable as the printed Official Timetable plus all Swiss city transit systems and networks as well as most railways in Europe. The user interface as well as all Swiss railways stations, and bus, boat, cable car stops are transparently available in German, French, Italian, and English spelling.
By Swiss Federal Railways (SBB CFF FFS):
SBB CFF FFS online
Printed Timetables: Departure/Arrival posters and pocket timetables as well as personal timetables of all SBB CFF FFS railway stations as PDF files.
Mobile Apps by SBB CFF FFS.
By Swiss PostBus (PostAuto, CarPostal, AutoPostale):
Swiss PostBus online ... and Mobile App
Network routes
United Kingdom
GB Rail Timetable
Published by The Stationery Office (the official UK Government publishers), and contains information, according to its title page, "with permission of Network Rail and obtained under licence the Rail Delivery Group. It closely resembles Network Rail's former timetable book, which ceased publication in 2007, but PDF timetable files are on its website.
It appears twice per year:
In May, titled GB Rail Timetable Summer Edition lasting from May to December
In December, titled GB Rail Timetable Winter Edition lasting from December to May
History
Until 1974 each region of British Rail published its own timetable. The first Great Britain timetable started on 4 May 1974. Prior to that the only joint publication between regions had been a publication of 30 principal passenger services from 1962, following the demise of Bradshaw in 1961. The final printed all-line timetable was produced by Network Rail in 2007, after which versions were published both by the Stationery Office and Middleton Press. Subsequently, The Stationery Office version has been discontinued and for the summer of 2016 Middleton Press only published a reprint of the UK pages of the European Rail Timetable, although a limited two-volume comprehensive version belatedly appeared in August.
See also
Clock-face scheduling
Train station announcement
References
External links
illustrated history of the timetable
Public transport information systems
Transportation planning
Scheduling (transportation) | Public transport timetable | [
"Technology"
] | 2,923 | [
"Public transport information systems",
"Information systems"
] |
8,624,952 | https://en.wikipedia.org/wiki/Current%20differencing%20transconductance%20amplifier | Current differencing transconductance amplifier (CDTA) is a new active circuit element.
Properties
The CDTA is not free from parasitic input capacitances and it can operate in a wide frequency range due to current-mode operation. Some voltage and current mode applications using this element have already been reported in literature, particularly from the area of frequency filtering: general higher-order filters, biquad circuits, all-pass sections, gyrators, simulation of grounded and floating inductances and LCR ladder structures. Other studies propose CDTA-based high-frequency oscillators. Nonlinear CDTA applications are also expected, particularly precise rectifiers, current-mode Schmitt triggers for measuring purposes and signal generation, current-mode multipliers, etc.
Basic operation
The CDTA element with its schematic symbol in Fig 1 has a pair of low-impedance current inputs and p, n and an auxiliary terminal z, whose outgoing current is the difference of input currents. Here, output terminal currents are equal in magnitude, but flow in opposite directions, and the product of transconductance () and the voltage at the z terminal gives their magnitudes. Therefore, this active element can be characterized with the following equations:
,
,
,
.
where and is the external impedance connected to z terminal of the CDTA. CDTA can be thought as a combination of a current differencing unit followed by a dual-output operational transconductance amplifier, DO-OTA. Ideally, the OTA is assumed as an ideal voltage-controlled current source and can be described by , where Ix is output current, and denote non-inverting and inverting input voltage of the OTA, respectively. Note that gm is a function of the bias current. When this element is used in CDTA, one of its input terminals is grounded (e.g., ). With dual output availability, condition is assumed.
References
Biolek, D.: CDTA – Building Block for Current- Mode Analog Signal Processing. In: Proceedings of the ECCTD’03, Kraków, Poland, Vol. III, (2003), 397-400
Keskin A.Ü., Biolek, D., Hancioglu, E., Biolková, V: Current-mode KHN filter employing current differencing transconductance amplifiers, AEU — International Journal of Electronics and Communications, 60, (2006), 443-446
Chen, H. Tsao, C. Chen,: Operational transresistance amplifier using CMOS technology. Electronic Letters., 28, 22 (1992), 2087–2088.
Electronic amplifiers | Current differencing transconductance amplifier | [
"Technology"
] | 564 | [
"Electronic amplifiers",
"Amplifiers"
] |
8,625,424 | https://en.wikipedia.org/wiki/Nudity%20in%20religion | Nudity in religion deals with religious beliefs as the basis for modern attitudes and behaviors regarding nudity.
Abrahamic religions
The Abrahamic religions of Judaism, Christianity, and Islam all recount the Genesis creation narrative in which Adam and Eve are unaware of their nakedness until they eat the forbidden fruit of the Tree of Knowledge of Good and Evil. After this, they feel ashamed and try to cover themselves with fig leaves. Judaism does not share the Christian association of nakedness with original sin, an aspect integral to the doctrine of redemption and salvation. In Islam the garden is in Paradise, not on Earth. This is to show that women and men should be covered in clothing, for nudity has the stigma of shame attached to it. Each of these religions has its own unique understanding of what is meant to be taught with the recounting of the story of Adam and Eve.
The biblical story of Bathsheba and apocryphal story of Susanna provide no reference within the text for blame to be placed on women. Regardless, some have interpreted these passages placing the blame of the men’s lusts on the women in the stories, despite the fact that the women are portrayed as victims in these stories rather than participants. In contrast, the apocryphal story of Judith portrays a woman who bathes publicly to seduce and later behead the enemy general Holofernes. The contrast of the story of Judith in her deliberate attempts to seduct contrast the actions of Susanna and Bathsheba, who were victims of the male gaze.
Of particular concern for both Islam and early Christians, as they extended their control over countries that had previously been part of the Byzantine or Roman empires, was the local custom of public bathing. While Christians were mainly concerned about mixed-gender bathing, which had been common, Islam also prohibited nudity for women in the company of non-Muslim women. In general, the Roman bathing facilities were adapted for separation of the genders, and the bathers retaining at least a loin-cloth as was the case in Victorian Turkish baths until the end of the 20th century.
Judaism
In Judaism, nudity is an aspect of body modesty which is regarded as very important in most social and familial situations. Attitudes to modesty vary between the different movements within Judaism as well as between communities within each movement. In more strict (orthodox) communities, modesty is an aspect of Tzniut which generally has detailed rules of what is appropriate behaviour. Conservative and Reform Judaism generally promote modesty values but do not regard the strict Tzniut rules as binding, with each person being permitted (at least in principle) to set their own standards. With the exception of the Haredi community, Jewish communities generally tend to dress according to the standards of the society in which they find themselves.
Orthodox Jewish Law (Halakha) explicitly makes women responsible for maintaining the virtue of modesty (Tzniut) by covering their bodies, including their hair. For men, nakedness was limited to exposure of the penis, but is not limited to public exposure, but in private as well. In late antiquity, Jews viewed with abhorrence the Greek and Roman practices of going naked and portraying male gods as naked. In any religious context, male nudity was of greater concern than female nudity because it was an offense against God. In everyday activity male nudity might be necessary, but is to be avoided. Female nudity was not an offense against God, but only about arousing the sexual passions of men, thus private or female only nudity was not immodest.
A person who enters a ritual bath (a mikveh) does so without clothing, and with no jewelry or even bandages.
Care needs to be taken when reading the Bible, where some references to nakedness serve as a euphemism for intimate sexual behaviour. For example, in the story of Noah the hesitancy of two of Noah's sons when they have to cover their father's nakedness can be seen, averting their eyes, after Noah's youngest son "saw his father's nakedness and told his two brothers outside" what he had done to his father. Nakedness may also be a metaphor for empty-handedness, specifically in situations where a sacrifice or offering to God is expected.
Christianity
Mainstream Christian denominations
There are verses in the Christian Bible that discuss the issue of nudity. Before the fall of man, "Nakedness was 'very good' from the beginning, but its innocence was corrupted by the fall", a concept taught in Genesis 1:31 and Genesis 2:25. Genesis 3:8–10, Revelation 3:18 and Revelation 16:15 discuss that after the fall of man, "publicly exposed nakedness [became] a symbol of the shame of sin." In Genesis 3:7, Adam and Eve tried to cover their nakedness, though their attempt was inadequate for God and so God properly clothed humans in Genesis 3:21. Exodus 20:26 and 28:42–43 explicate that God instructed humans to cover their torso and thighs.
The early Church reflected the contemporary attitudes of Judaism towards nudity. The Old Testament is not positive towards nudity. In Isaiah 20, Isaiah walks nude as a sign of shame.
The first recorded liturgy of baptism, written down by Saint Hippolytus of Rome in his Apostolic Tradition, required men, women and children to remove all clothing, including all foreign objects such as jewelry and hair fastenings. However Laurie Guy argues that complete nudity for baptism candidates (especially women) would not be the norm. He notes that at certain times and in certain places candidates may have been totally naked at the point of baptism, but the Jewish taboo of female nakedness would have mitigated widespread practice of naked baptism.
Later Christian attitudes to nudity became more restrictive, and baptisms were segregated by sex and then later were usually performed with clothed participants. Some of the Eastern Orthodox churches today maintain the early church's liturgical use of baptismal nudity, particularly for infants but also for adults.
Several saints, such as a number of the Desert Fathers as well as Basil Fool for Christ, practiced nudity as a form of ascetic poverty.
Early Christian art included depictions of nudity in baptism. When artistic endeavours revived following the Renaissance, the Catholic Church was a major sponsor of art bearing a religious theme, many of which included subjects in various states of dress and including full nudity. Painters sponsored by the Church included Raphael, Caravaggio and Michelangelo, but there were many others. Many of these paintings and statues were and continue to be displayed in churches, some of which were painted as murals, the most famous of which are at the Sistine Chapel painted by Michelangelo.
, in discussing logion 37 of the Gospel of Thomas, notes that early Christian art depicts, as one would expect, Adam and Eve in Paradise naked. The only other Old Testament figures who are depicted nude are Jonah emerging from the mouth of the Great Fish, Daniel emerging from the Lion's Den, and the resurrected in Ezekiel's vision of the dry bones: these Old Testament scenes containing nude figures are precisely those which were held to be types of the resurrection. Among the New Testament illustrations, apart from baptismal scenes, there are nudes only in one representation of the raising of Lazarus and one representation of the Miracle at Cana.
In light of Exodus 29:26 and 28:42–43 in the Bible, which teach that nakedness is inclusive of anything that exposes the torso and thighs, Methodists of the conservative holiness movement wear pants or dresses that go beyond the knees, as well as shirts that cover the underarms.
In 1981, Pope John Paul II expressed the Catholic Church's attitude to the exposure of the human body in Love and Responsibility: "The human body can remain nude and uncovered and preserve intact its splendour and its beauty... Nakedness as such is not to be equated with physical shamelessness... Immodesty is present only when nakedness plays a negative role with regard to the value of the person... The human body is not in itself shameful... Shamelessness (just like shame and modesty) is a function of the interior of a person."
Christian naturist sects
Sects have arisen within Christianity from time to time that have viewed nudity in a more positive light. For example, to the Adamites and the Freedomites, social nudity was an integral part of their ritual. The Adamites, an early Christian sect, practiced "holy nudism", engaging in common worship in the nude. During the Middle Ages, the doctrines of this obscure sect were revived: in the Netherlands by the Brethren of the Free Spirit and the Taborites in Bohemia, and, in a grosser form, by the Beghards in Germany. Everywhere, they met with firm opposition from the mainstream Christian churches.
A religious sect in Canada that immigrated from Russia, the Sons of Freedom, went so far in the 20th century (1903–1950s) as to publicly strip in mass public demonstrations to protest against government policies which were meant to assimilate them.
Christian naturism contains various members associated with most denominations. Although beliefs vary, a common theme is that much of Christianity has misinterpreted the events regarding the Garden of Eden, and God was displeased with Adam and Eve for covering their bodies with fig leaves. argues that the significance of the human need for clothing by far exceeds its theological meaning.
Islam
The practice known as veiling of women in public predates Islam in Persia, Syria, and Anatolia. Islamic clothing for men covers the area from the waist to the knees. In the medieval period, Islamic norms became more patriarchal, and very concerned with the chastity of women before marriage and fidelity afterward. Women were not only veiled, but segregated from society, with no contact with men not of close kinship, the presence of whom defined the difference between public and private spaces.
Islamic countries are guided by rules of modesty that forbid nudity, with variations between five schools of Islamic law. The most conservative is the Hanbali School in Saudi Arabia and Qatar, where it is widespread for women wear the niqab, the garment covering the whole body and the face with a narrow opening for the eyes. Hands are also hidden within sleeves as much as possible. The burqa, limited mainly to Afghanistan, also has a mesh screen which covers the eye opening. Different rules apply to men, women, and children; and depend upon the gender and family relationship of others present. The Sunni scholar Yusuf al-Qaradawi states that looking at the intimate parts of the body of another of either sex must be avoided. For women after puberty, the prohibition includes the entire body except the hands and face. However, hands and face may be shown only if they may be viewed without temptation. Men must cover themselves from the navel to the knees. Shame dictates that the genitals should be covered even when a person is alone. The dress of women must not only cover virtually the entire body, but cannot be either transparent or close-fitting to reveal the shape of the body. When onlookers are close relations, prohibitions for women do not include hair, ears, neck, upper part of the chest, arms and legs. The same exceptions are also made for men seeing women to whom they are proposing marriage.
Indian/Dharmic religions
In ancient Indian cultures, there was a tradition of extreme asceticism (obviously minoritarian) that included full nudity. This tradition continued from the gymnosophists (philosophers in antiquity) to certain holy men (who may however cover themselves with ashes) in present-day Hindu devotion and in Jainism.
In the 4th century BC, Alexander the Great encountered, in India, wandering groups of naked holy men whom he dubbed the naked philosophers (Gr gymnos: naked; sophist: knowledge). The philosopher Onesicritus investigated their beliefs and lifestyle. Pyrrho the Sceptic was impressed and incorporated nudity into his philosophy. The Gymnosophists were Hindus, but Jain and Ajivika monks practiced nudity as a statement that they had given up all worldly goods.
Hinduism
Philosophical basis
The philosophical basis of nudity arises out of the concept of 'Purushartha' (four ends of human life). 'Purushartha' (Puruṣārtha) are 'Kama' (enjoyment), 'Artha' (wealth), ‘Dharma’ (virtue) and 'Moksha' (liberation). It is ‘Purushartha’ which impels a human being towards nudity or any of its related aspect(s) either for spiritual aim or for the aim of enjoyment. Practice of ‘Dharma’ (virtue) brings good result(s) and non-practice of 'Dharma' leads to negative result(s).
Spiritual basis
In the spiritual aspect of Hinduism nudity symbolises renunciation of the highest type. A nude person or deity (for example, some depictions of Kali) denotes one who is devoid of maya or attachment to the body and one who is an embodiment of infinity. Trailanga Swami, the famous nude saint of India, had given an explanation for nudity in religion in the following words, "Lahiri Mahasaya is like a divine kitten, remaining wherever the Cosmic Mother has placed him. While dutifully playing the part of a worldly man, he has received that perfect Self-realization which I have sought by renouncing everything – even my loincloth!"
Material basis
In comparison in the material aspect nudity is considered an art. This view is supported by Sri Aurobindo in his book The Renaissance in India. He says about Hinduism in the book – "Its spiritual extremism could not prevent it from fathoming through a long era the life of the senses and its enjoyments, and there too it sought the utmost richness of sensuous detail and the depths and intensities of sensual experience. Yet it is notable that this pursuit of the most opposite extremes never resulted in disorder…"
Extreme hedonists and materialists like the Charvakas are very candid with regard to pursuing of sensual pleasures. They say, "Marthakamaveva purusharthau" (Riches and pleasure is the summum bonum of life). There is another sloka in support of their view – "Anganalingananadijanyam sukhameva purusatha" (The sensual pleasure arising from the embrace of a woman and other objects is the highest good or end). For non-hedonists pursuing kama (sensual pleasures) accompanied with dharma (virtue) can be the highest ideal or goal in life. There is nothing wrong in it.
Occurrence
Some of the famous nude male and female yogi (male and female saints of India) of Hinduism include Lalla Yogishwari (Lalleshwari), Trailanga Swami, Harihar Baba, Tota Puri. Also in the biography of saint Gorakhnath we have reference to nude male and female yogis who had visited the famous Amarnath Temple during medieval period of India.
Among the Hindu religious sects, only the sadhus (monks) of the Nāga sect can be seen nude. They usually wear a loin-cloth around their waist, but not always; and usually remain in their Akhara or deep forest or isolation and come out in public only once every four years during Kumbh Mela. They have a very long history and are warrior monks, who usually also carry a talwar (sword), trishula (trident), bhala (javelin) or such weapons, and in medieval times have fought many wars to protect Hindu temples and shrines.
Jainism
In India, Digambara monks reject any form of clothing and practice nudity. Digambara (lit. 'sky clad') is one of the two main sects of Jainism. However, the Shvetambara sect is "white-clad" and their holy statues wear a loin cloth.
New religious movements
Neopaganism
In many modern neopagan religious movements, such as Wicca, social and ritual nudity is (relatively) commonplace. In Wicca, the term skyclad refers to ritual nudity instead of social nudity.
Raëlism
In Raëlism, nudity is not problematic. Raëlists in North America have formed GoTopless.org, which organizes demonstrations in support of topfreedom on the basis of the legal and public attitudes to the gender inequality. GoTopless sponsors an annual "Go Topless Day" protest (also known as "National GoTopless Day", "International Go-Topless Day", etc.) in advocacy for women's right to go topless on gender equality grounds.
See also
References
Notes
Citations
Sources
Further reading
External links
Christian Nudist Convocation : Supporting and Gathering Christian Nudists
gotopless.org
Raëlism: Publicity as a Recruitment Technique
Religious practices
Religion and society | Nudity in religion | [
"Biology"
] | 3,522 | [
"Behavior",
"Religious practices",
"Human behavior"
] |
8,625,600 | https://en.wikipedia.org/wiki/Phytane | Phytane is the isoprenoid alkane formed when phytol, a chemical substituent of chlorophyll, loses its hydroxyl group. When phytol loses one carbon atom, it yields pristane. Other sources of phytane and pristane have also been proposed than phytol.
Pristane and phytane are common constituents in petroleum and have been used as proxies for depositional redox conditions, as well as for correlating oil and its source rock (i.e. elucidating where oil formed). In environmental studies, pristane and phytane are target compounds for investigating oil spills.
Chemistry
Phytane is a non-polar organic compound that is a clear and colorless liquid at room temperature. It is a head-to-tail linked regular isoprenoid with chemical formula C20H42.
Phytane has many structural isomers. Among them, crocetane is a tail-to-tail linked isoprenoid and often co-elutes with phytane during gas chromatography (GC) due to its structural similarity.
Phytane also has many stereoisomers because of its three stereo carbons, C-6, C-10 and C-14. Whereas pristane has two stereo carbons, C-6 and C-10. Direct measurement of these isomers has not been reported using gas chromatography.
The substituent of phytane is phytanyl. Phytanyl groups are frequently found in archaeal membrane lipids of methanogenic and halophilic archaea (e.g., in archaeol). Phytene is the singly unsaturated version of phytane. Phytene is also found as the functional group phytyl in many organic molecules of biological importance such as chlorophyll, tocopherol (vitamin E), and phylloquinone (vitamin K1). Phytene's corresponding alcohol is phytol. Geranylgeranene is the fully unsaturated form of phytane, and its corresponding substituent is geranylgeranyl.
Sources
The major source of phytane and pristane is thought to be chlorophyll. Chlorophyll is one of the most important photosynthetic pigments in plants, algae, and cyanobacteria, and is the most abundant tetrapyrrole in the biosphere. Hydrolysis of chlorophyll a, b, d, and f during diagenesis in marine sediments, or during invertebrate feeding releases phytol, which is then converted to phytane or pristane.
Another possible source of phytane and pristane is archaeal ether lipids. Laboratory studies show that thermal maturation of methanogenic archaea generates pristane and phytane from diphytanyl glyceryl ethers (archaeols).
In addition, pristane can be derived from tocopherols and methyltrimethyltridecylchromans (MTTCs).
Preservation
In suitable environments, biomolecules like chlorophyll can be transformed and preserved in recognizable forms as biomarkers. Conversion during diagenesis often causes the chemical loss of functional groups like double bonds and hydroxyl groups.
Studies suggested that pristane and phytane are formed via diagenesis of phytol under different redox conditions. Pristane can be formed in oxic (oxidizing) conditions by phytol oxidation to phytenic acid, which may then undergo decarboxylation to pristene, before finally being reduced to pristane. In contrast, phytane is likely from reduction and dehydration of phytol (via dihydrophytol or phytene) under relatively anoxic conditions. However, various biotic and abiotic processes may control the diagenesis of chlorophyll and phytol, and the exact reactions are more complicated and not strictly-correlated to redox conditions.
In thermally immature sediments, pristane and phytane has a configuration dominated by 6R,10S stereochemistry (equivalent to 6S, 10R), which is inherited from C-7 and C-11 in phytol. During thermal maturation, isomerization at C-6 and C-10 leads to a mixture of 6R, 10S, 6S, 10S, and 6R, 10R.
Geochemical parameters
Pristane/Phytane ratio
Pristane/phytane (Pr/Ph) is the ratio of abundances of pristane and phytane. It is a proxy for redox conditions in the depositional environments. The Pr/Ph index is based on the assumption that pristane is formed from phytol by an oxidative pathway, while phytane is generated through various reductive pathways. In non-biodegraded crude oil, Pr/Ph less than 0.8 indicates saline to hypersaline conditions associated with evaporite and carbonate deposition, whereas organic-lean terrigenous, fluvial,and deltaic sediments under oxic to suboxic conditions usually generate crude oil with Pr/Ph above 3. Pr/Ph is commonly applied because pristane and phytane are measured easily using gas chromatography.
However, the index should be used with caution, as pristane and phytane may not result from degradation of the same precursor (see *Source*). Also, pristane, but not phytane, can be produced in reducing environments by clay-catalysed degradation of phytol and subsequent reduction. Additionally, during catagenesis, Pr/Ph tends to increase. This variation may be due to preferential release of sulfur-bound phytols from source rocks during early maturation.
Pristane/nC17 and phytane/nC18 ratios
Pristane/n-heptadecane (Pr/nC17) and phytane/n-octadecane (Ph/C18) are sometimes used to correlate oil and its source rock (i.e. to elucidate where oil formed). Oils from rocks deposited under open-ocean conditions showed Pr/nC17< 0.5, while those from inland peat swamp had ratios greater than 1.
The ratios should be used with caution for several reasons. Both Pr/nC17and Ph/nC18 decrease with thermal maturity of petroleum because isoprenoids are less thermally stable than linear alkanes. In contrast, biodegradation increases these ratios because aerobic bacteria generally attack linear alkanes before the isoprenoids. Therefore, biodegraded oil is similar to low-maturity non-degraded oil in the sense of exhibiting low abundance of n-alkanes relative to pristane and phytane.
Biodegradation scale
Pristane and phytane are more resistant to biodegradation than n-alkanes, but less so than steranes and hopanes. The substantial depletion and complete elimination of pristane and phytane correspond to a Biomarker Biodegradation Scale of 3 and 4, respectively.
Compound specific isotope analyses
Carbon isotopes
The carbon isotopic composition of pristane and phytane generally reflects the kinetic isotope fractionation that occurs during photosynthesis. For example, δ13C(PDB) of phytane in marine sediments and oils has been used to reconstruct ancient atmospheric CO2levels, which affects the carbon isotopic fractionation associated with photosynthesis, over the past 500 million years. In this study, partial pressure of CO2 reached more than 1000 ppm at maxima compared to 410 ppm today.
Carbon isotope compositions of pristane and phytane in crude oil can also help to constrain their source. Pristane and phytane from a common precursor should have δ13C values differing by no more than 0.3‰.
Hydrogen isotopes
Hydrogen isotope composition of phytol in marine phytoplankton and algae starts out as highly depleted, with δD (VSMOW) ranging from -360 to -280‰. Thermal maturation preferentially releases light isotopes, causing and pristane and phytane to become progressively heavier with maturation.
Case study: limitation of Pr/Ph as a redox indicator
Inferences from Pr/Ph on the redox potential of source sediments should always be supported by other geochemical and geological data, such as sulfur content or the C35 homohopane index (i.e. the abundance of C35 homohopane relative to that of C31-C35 homohopanes). For example, the Baghewala-1 oil from India has low Pr/Ph (0.9), high sulfur (1.2 wt.%) and high C35 homohopane index, which are consistent with anoxia during deposition of the source rock.
However, drawing conclusion on the oxic state of depositional environments only from Pr/Ph ratio can be misleading because salinity often controls the Pr/Ph in hypersaline environments. In another example, the decrease in Pr/Ph during deposition of the PermianKupferschiefer sequence in Germany is in coincidence with an increase in trimethylated 2-methyl-2-(4,8,12-trimethyltridecyl)chromans, an aromatic compound believed to be markers of salinity. Therefore, this decrease in Pr/Ph should indicate an increase in salinity, instead of an increase in anoxia.
See also
Phytol
Pristane
Biomarker
Crocetane
Archaeol
Tocopherols
Sterane
Hopane
References
Alkanes
Diterpenes | Phytane | [
"Chemistry"
] | 2,098 | [
"Organic compounds",
"Alkanes"
] |
8,626,253 | https://en.wikipedia.org/wiki/Alexei%20Smirnov%20%28physicist%29 | Alexei Yuryevich Smirnov (; born October 16, 1951) is a neutrino physics researcher and one of the discoverers of the MSW Effect.
Education
Alexei Smirnov graduated from MSU Faculty of Physics of Moscow State University in 1974. In 1977, he began to work at the Institute for Nuclear Research (INR) of the Academy of Sciences of the USSR, where he received his Candidate of Sciences degree in 1979. In 1989, he received a degree of Doctor of Physical and Mathematical sciences. He also taught at the Faculty of Physics of Moscow State University in the period from 1982 to 1990.
Smirnov joined the International Centre for Theoretical Physics (ICTP) in Trieste, Italy in 1992 as a staff-associate while continuing his affiliation with INR (Moscow) as a leading research scientist. He became a staff member with ICTP in 1997 and where he held the position of principal research scientist. Since 2015 he is a permanent scientist and Max-Planck Fellow at the Max-Planck-Institut für Kernphysik (MPIK) in Heidelberg.
Research and achievements
The main area of Smirnov's research is neutrino physics and astrophysics. In 1984—1985, following earlier work by Lincoln Wolfenstein, Smirnov, together with Stanislav Mikheyev, uncovered effects of resonance enhancement of neutrino oscillations in matter and the adiabatic conversion in non-uniform media known now as the Mikheyev–Smirnov–Wolfenstein effect (MSW effect). Solutions to the solar neutrino problem based on the MSW effect have been proposed. The effects were also applied to supernova neutrinos and neutrinos of various origins propagating in the Earth.
In the following years Smirnov and his colleagues developed a number of aspects of theory and phenomenology of neutrino conversion in various media. Currently Smirnov is working on implications of the obtained neutrino results for fundamental physics (quark-lepton complementarity, unification, etc.) as well as on future programs of studies in neutrino physics.
Smirnov is a co-recipient of the 2005 Bruno Pontecorvo Prize "for his prediction and study of the influence of matter on neutrino oscillations". For his lifetime achievements in physics Smirnov was named Humboldt Research Fellow. This is one of the Germany's most prestigious awards in science which enables outstanding scientists and scholars from abroad to spend up to six months at the Humboldt Institute to carry out research on projects of their own choosing. Alexei Smirnov and Stanislav Mikheyev were awarded the 2008 Sakurai Prize "for pioneering and influential work on the enhancement of neutrino oscillations in matter, which is essential to a quantitative understanding of the solar neutrino flux".
Smirnov is an editor of the Journal of High Energy Physics and Journal of Cosmology and Astroparticle Physics and a divisional associate editor for Physical Review Letters. He is also member of the advisory board of the journal Universe. His awards and honors also include the Biedenharn endowed chair in physics (University of Texas, Austin, 2002), the award of the Japanese Society for promotion of science (2004), an Alexander von Humboldt Foundation research award (2004), and the Erwin Schrödinger guest professorship (Vienna, 2007), as well as the 2016 Albert Einstein Medal.
See also
List of theoretical physicists
References
External links
Alexei Smirnov's papers in the INSPIRE database
1951 births
Living people
Soviet physicists
20th-century Russian physicists
Neutrino physicists
Moscow State University alumni
Academic staff of Moscow State University
Theoretical physicists
Albert Einstein Medal recipients
J. J. Sakurai Prize for Theoretical Particle Physics recipients
21st-century Russian physicists
Russian scientists | Alexei Smirnov (physicist) | [
"Physics"
] | 787 | [
"Theoretical physics",
"Theoretical physicists"
] |
8,626,724 | https://en.wikipedia.org/wiki/Pallet%20inverter | A pallet inverter or pile turner is a machine that is used to turn over full pallet loads of packages or products. The term pallet inverter is also used to cover machines that turn the palletised load through 90 degrees only.
Use
The reasons for needing to turn over a pallet are varied. The primary reason is have access to the bottom of the load without having to manually unload all of the boxes or bags. If a pallet or slip sheet is damaged. it can be replaced by inverting the load, replacing it, and re-inverting the load. Sometimes a manufacturer simply needs to turn their products to stop their contents settling. In some industries, it is necessary to transfer goods from one type of pallet to another – for example, when plastic pallets are used for on-site storage and wooden pallets are used for shipping.
Some products require rapid freezing immediately after production and packaging. Processes can utilize freezer spacers between each tier of boxes on a pallet: these promote air flow for controlled and accelerated refrigeration. Prior to shipping, these spacers can be removed using a pallet inverter. This rotates the load ninety degrees to allow easy removal and reuse.
Pallet inverters can be built into production lines or be used as a stand-alone product.
See also
Bulk material handling
Conveyor system
Palletizer
Slip sheet
References
External links
Removing freezer spacers
Pallets
Packaging machinery
Industrial equipment | Pallet inverter | [
"Engineering"
] | 305 | [
"Packaging machinery",
"Industrial machinery",
"nan"
] |
8,628,305 | https://en.wikipedia.org/wiki/Belokamenka%20%28ship%29 | Belokamenka was an oil tanker (a very large crude carrier, a VLCC). It was latterly used as an FSO (floating production storage and offloading) vessel moored off in Kola Bay near Murmansk and after 2015 off Singapore. Belokamenka was scrapped in April 2019.
History
Belokamenka was originally built by Mitsui Eng. & Shipbuilding Co., Ltd., Chiba Works, on 1980. Its name was Berge Pioneer until 2004.
Technical features
Belokamenka has a length of and width of . It handled four million tonnes of crude oil per year, shipped in by small shuttle tankers from Arkhangelsk.
Operator
Belokamenka was chartered by Rosnefteflot, a subsidiary of Rosneft, on a long-term basis. It was operated by the Oil Terminal "Belokamenka" L.L.C.
References
External links
Images
Floating production storage and offloading vessels
Service vessels of Russia
Oil tankers
Rosneft
1980 ships
Ships built by Mitsui Engineering and Shipbuilding | Belokamenka (ship) | [
"Chemistry"
] | 225 | [
"Floating production storage and offloading vessels",
"Petroleum technology"
] |
10,763,773 | https://en.wikipedia.org/wiki/Pontypool%20japan | Pontypool japan is a name given to the process of japanning with the use of an oil varnish and heat, which is credited to Thomas Allgood of Pontypool. In the late 17th century, during his search for a corrosion-resistant coating for iron, he developed a recipe that included asphaltum, linseed oil and burnt umber. Once applied to metal and heated the coating turned black and was extremely tough and durable.
Pontypool is in a steep valley in South Wales, surrounded by coal and iron working. The iron used was produced by the furnaces of Blaenavon to the north, and most of the "Pontypool ware" was actually produced in nearby Usk or Newport, at the southern end of the valley.
Background
In the late 17th century, there was a developing trade in metal goods made of thin iron sheet, spurred by the development of the rolling mill. Rustproofing this iron was important. Tin plating had been developed in Germany, and British manufacturers needed to compete.
While it was the growth of the iron foundries and tin plating that gave birth to japanning on metal, tin plated iron was not the only metal used. There are examples of brass, copper and bronze used as substrates. In France, copper was the metal primarily used. Because it had to be hammered into shape rather than rolled and stamped, the surface was uneven. This did not provide the best surface for japanning, thus it has a greater tendency to flake off than the smoother English tinware. When the French made tinware it was often trimmed with bronze.
The use of metal allowed a variety of forms that were required to withstand heat and water. Coffee pots, tea sets, candle sticks and other household items could all be japanned and decorated in the popular fashion.
These japanned metal objects are very stable so a great many still survive. Many pieces survive today with little rust. In most cases it is easy to ascertain the underlying metal because it can be seen in losses or scratches. If the japanning is intact, a magnet can be used to identify iron. Most iron trays show some rust on the back where only a single coating was applied. Even the tin plated iron objects show rust in some areas.
It is worth remembering the unavailability of effective paint, at this time. The surface finishes that did exist either had poor adhesion to their substrate, or required either a porous or an organic substrate to bond to. Today's resin-based paints for metals had not been invented.
Recipes
Similar recipes or "secret varnishes" were also used in Birmingham. In his book on Pontypool japan (W. D. John, 1953), published one of the recipes the workmen had handed down through generations:
448 pounds of raw linseed oil
22 pounds of lump umber
20 pounds of flake litharge
100 pounds of asphaltum
5 pounds of cobalt resinate
406 pounds of white spirit or turpentine
The linseed oil was heated together with the umber and the asphaltum while the litharge and cobalt were added slowly. According to the recipe, the varnish was ready when a drop of varnish dripped onto cold glass remained in a ball. After cooling, the turpentine was added. There was also a pale clear version which omitted the asphaltum and the cobalt. In modern tests, this varnish worked equally well on papier mâché and metal plates. Three coats produced a durable glossy black finish.
This recipe is similar to one for gold size published by both (Robert Dossie, 1764) and (Stalker and Parker, 1688). In that version, linseed oil is boiled together with gum animi, asphaltum, litharge and umber in approximately the same proportions as the Pontypool recipe. (Watin, 1755) also describes the use of asphaltum as an addition to the well-known spirit varnishes of the day. It appears that the secret recipe for Pontypool japan had been in existence for some time before its use for japanning metal.
See also
Japan black
References
Further reading
Salmon, W. Polygraphice, or, The arts of drawing, engraving, etching, limning, painting, vernishing, japaning, gilding, &c. : in two volumes ..., London 1701.online
Brown, W. N. A Handbook on Japanning and Enamelling for Cycles, Bedsteds, Tinware, Etc., London 1901. online
Industrial Revolution
Corrosion prevention
Paints | Pontypool japan | [
"Chemistry"
] | 937 | [
"Paints",
"Coatings",
"Corrosion prevention",
"Corrosion"
] |
10,764,126 | https://en.wikipedia.org/wiki/NeuroArm | NeuroArm is an engineering research surgical robot specifically designed for neurosurgery. It is the first image-guided, MR-compatible surgical robot that has the capability to perform both microsurgery and stereotaxy.
IMRIS, Inc. acquired NeuroArm assets in 2010, and the company is working to develop a next generation of the technology for worldwide commercialization. It will be integrated with the VISIUS(TM) Surgical Theatre under the name SYMBIS(TM) Surgical System.
Design
NeuroArm was designed to be image-guided and can perform procedures inside an MRI. NeuroArm includes two remote detachable manipulators on a mobile base, a workstation and a system control cabinet. For biopsy-stereotaxy, either the left or right arm is transferred to a stereotactic platform that attaches to the MR bore. The procedure is performed with image-guidance, as MR images are acquired in near real-time. The end-effectors interface with surgical tools which are based on standard neurosurgical instruments.
End-effectors are equipped with three-dimensional force-sensors, providing the sense of touch. The surgeon seated at the workstation controls the robot using force feedback hand controllers. The workstation recreates the sight and sensation of microsurgery by displaying the surgical site and 3D MRI displays, with superimposed tools. NeuroArm enables remote manipulation of the surgical tools from a control room adjacent to the surgical suite. It was designed to function within the environment of 1.5 and 3.0 tesla intraoperative MRI systems. As neuroArm is MR-compatible, stereotaxy can be performed inside the bore of the magnet with near real-time image guidance. NeuroArm possesses the dexterity to perform microsurgery, outside of the MRI system.
Telerobotic operations both inside and outside the magnet are performed using specialized tool sets based on standard neurosurgical instruments, adapted to the end effectors. Using these, NeuroArm is able to cut and manipulate soft tissue, dissect tissue planes, suture, biopsy, electrocauterize, aspirate and irrigate.
History
The project began in 2002 when Daryl, B.J., and Don Seaman provided $2 million to fund the design efforts. Dr. Sutherland and his group established a collaboration with the Canadian space engineering company MacDonald Dettwiler and Associates (MDA). Close collaboration between MDA's robotic engineers and University of Calgary physicians, nurses, and scientists contributed to the design and development of NeuroArm. Official launch of the project was on April 17, 2007.
NeuroArm was designed to take full advantage of the imaging environment provided by intraoperative MRI. The ability to couple near real-time, high resolution images to robotic technologies provides the surgeon with image guidance, precision, accuracy, and dexterity. MDA's engineers were immersed in the operating room to study typical tool and surgeon motions in order to use biomimicry for effective design of the computer-assisted surgical device. The OR environment, personnel, surgical rhythm and instrumentation remain unchanged. The surgeon, sitting at the workstation, is provided a virtual environment that recreates the sight, sound, and touch of surgery. Functions like tremor filtering and motion scaling were applied to increase precision and accuracy while functions like no-go zones and linear lock were applied to enhance safety. Surgical tools near the patient's head are incapable of fully independent movement and are slaved to the surgeon’s movement at all times. Pre-planned automatic motions are used to move the robot arms away from the patient's head for manual tool exchange, and then return them to the original position and orientation.
On May 12, 2008, the first image-guided MR-compatible robotic neurosurgical procedure was performed at University of Calgary by Dr. Garnette Sutherland using the NeuroArm.
References
External links
Project neuroArm
Seaman Family MR Research Centre
SYMBIS Homepage on IMRIS Website
Videos
Video in press release for NeuroArm unveiling, University of Calgary, April 17, 2007
Related patents
Canadian Patent 2246369 Surgical procedure with magnetic resonance imaging
US Patent 5,735,278 (at USPTO) Surgical procedure with magnetic resonance imaging
US Patent 5,735,278 (at Google) Surgical procedure with magnetic resonance imaging
Neurosurgery
Surgical robots
Biomedical engineering | NeuroArm | [
"Engineering",
"Biology"
] | 914 | [
"Biological engineering",
"Medical technology",
"Biomedical engineering"
] |
10,766,062 | https://en.wikipedia.org/wiki/NGC%206027d | NGC 6027d is a barred spiral galaxy that is strictly a visual member of Seyfert's Sextet, a compact group of galaxies, which is located in the constellation Serpens. NGC 6027d is not interacting with the other galaxies in the cluster, but is in the background and just happens to be in the same line of sight. The galaxy is nearly 700 million light years away from the interacting group, and is estimated to be about 180,000 light-years in diameter.
One supernova has been observed in NGC 6027d: SN 1998fe (type unknown, mag. 18) was discovered by the Lick Observatory Supernova Search on 19 July 1998.
See also
NGC 6027
NGC 6027a
NGC 6027b
NGC 6027c
NGC 6027e
List of NGC objects (6001–7000)
References
External links
HubbleSite NewsCenter: Pictures and description
Barred spiral galaxies
Serpens
6027d
056580
10116 NED05
+04-38-009
Astronomical objects discovered in 1951 | NGC 6027d | [
"Astronomy"
] | 216 | [
"Constellations",
"Serpens"
] |
10,766,404 | https://en.wikipedia.org/wiki/Generalised%20circle | In geometry, a generalized circle, sometimes called a cline or circline, is a straight line or a circle, the curves of constant curvature in the Euclidean plane.
The natural setting for generalized circles is the extended plane, a plane along with one point at infinity through which every straight line is considered to pass. Given any three distinct points in the extended plane, there exists precisely one generalized circle passing through all three.
Generalized circles sometimes appear in Euclidean geometry, which has a well-defined notion of distance between points, and where every circle has a center and radius: the point at infinity can be considered infinitely distant from any other point, and a line can be considered as a degenerate circle without a well-defined center and with infinite radius (zero curvature). A reflection across a line is a Euclidean isometry (distance-preserving transformation) which maps lines to lines and circles to circles; but an inversion in a circle is not, distorting distances and mapping any line to a circle passing through the reference circles's center, and vice-versa.
However, generalized circles are fundamental to inversive geometry, in which circles and lines are considered indistinguishable, the point at infinity is not distinguished from any other point, and the notions of curvature and distance between points are ignored. In inversive geometry, reflections, inversions, and more generally their compositions, called Möbius transformations, map generalized circles to generalized circles, and preserve the inversive relationships between objects.
The extended plane can be identified with the sphere using a stereographic projection. The point at infinity then becomes an ordinary point on the sphere, and all generalized circles become circles on the sphere.
Extended complex plane
The extended Euclidean plane can be identified with the extended complex plane, so that equations of complex numbers can be used to describe lines, circles and inversions.
Bivariate linear equation
A circle is the set of points in a plane that lie at radius from a center point
In the complex plane, is a complex number and is a set of complex numbers. Using the property that a complex number multiplied by its conjugate is the square of its modulus (its Euclidean distance from the origin), an implicit equation for is:
This is a homogeneous bivariate linear polynomial equation in terms of the complex variable and its conjugate of the form
where coefficients and are real, and and are complex conjugates.
By dividing by and then reversing the steps above, the radius and center can be recovered from any equation of this form. The equation represents a generalized circle in the plane when is real, which occurs when so that the squared radius is positive. When is zero, the equation defines a straight line.
Complex reciprocal
That the reciprocal transformation maps generalized circles to generalized circles is straight-forward to verify:
Lines through the origin map to lines through the origin; lines not through the origin map to circles through the origin; circles through the origin map to lines not through the origin; and circles not through the origin map to circles not through the origin.
Complex matrix representation
The defining equation of a generalized circle
can be written as a matrix equation
Symbolically,
with coefficients placed into an invertible hermitian matrix representing the circle, and a vector representing an extended complex number.
Two such matrices specify the same generalized circle if and only if one is a scalar multiple of the other.
To transform the generalized circle represented by by the Möbius transformation apply the inverse of the Möbius transformation to the vector in the implicit equation,
so the new circle can be represented by the matrix
Notes
References
Hans Schwerdtfeger, Geometry of Complex Numbers, Courier Dover Publications, 1979
Michael Henle, "Modern Geometry: Non-Euclidean, Projective, and Discrete", 2nd edition, Prentice Hall, 2001
David W. Lyons (2021) Möbius Geometry from LibreTexts
Circles
Inversive geometry | Generalised circle | [
"Mathematics"
] | 790 | [
"Circles",
"Pi"
] |
10,766,478 | https://en.wikipedia.org/wiki/Homometric%20structures | In chemistry and crystallography, crystal structures that have the same set of interatomic distances are called homometric structures. Homometric structures need not be congruent (that is, related by a rigid motion or reflection). Homometric crystal structures produce identical diffraction patterns; therefore, they cannot be distinguished by a diffraction experiment.
Recently, a Monte Carlo algorithm was proposed to calculate the number of homometric structures corresponding to any given set of interatomic distances.
See also
Patterson function
Arthur Lindo Patterson
References
Stereochemistry | Homometric structures | [
"Physics",
"Chemistry",
"Materials_science"
] | 112 | [
"Materials science stubs",
"Stereochemistry",
"Crystallography stubs",
"Crystallography",
"Space",
"Stereochemistry stubs",
"nan",
"Spacetime"
] |
10,766,750 | https://en.wikipedia.org/wiki/International%20Union%20of%20Crystallography | The International Union of Crystallography (IUCr) is an organisation devoted to the international promotion and coordination of the science of crystallography. The IUCr is a member of the International Council for Science (ICSU).
Objectives
The objectives of the IUCr are to promote international cooperation in crystallography and to contribute to all aspects of crystallography, to promote international publication of crystallographic research, to facilitate standardization of methods, units, nomenclatures and symbols, and to form a focus for the relations of crystallography to other sciences.
The IUCr fulfils these objectives by publishing in print and electronically primary scientific journals through the Acta Crystallographica journal series, as well as Journal of Applied Crystallography, Journal of Synchrotron Radiation, IUCrJ, the series of reference volumes International Tables for Crystallography, distributing the quarterly IUCr Newsletter, maintaining the online World Directory/Database of Crystallographers, awarding the Ewald Prize and organising the triennial Congress and General Assembly.
History
In 1944 the yearly meeting of the X-ray Analysis Group (XRAG) of the UK Institute of Physics was held in Oxford, and the distinguished German crystallographer Paul Peter Ewald, who then taught at Queen's University Belfast, was invited to give the evening lecture. In it he gave a historical survey of some of the stages in the evolution of X-ray crystallography and ended with a strong plea for the formation of an international society or union which would represent, and unify publication for, the new science. This idea was followed up by the British crystallographers, and particularly by Sir Lawrence Bragg, the Chairman of XRAG. In June 1946, within a year of the termination of fighting in WWII, he arranged for an international meeting of crystallographers in London which was attended by some 120 scientists from most of the allied countries. In that London meeting Ewald was elected Chairman of the Provisional International Crystallographic Committee, which put into action the decision to form the International Union of Crystallography.
Presidents
Sir Lawrence Bragg was the first formally elected President of the IUCr, with Ralph Walter Graystone Wyckoff and Arne Westgren as Vice-Presidents. Ewald was elected as 5th President of the IUCr, the 'international society or union' that he had originally conceived, in 1960.
1948 – Lawrence Bragg
1951 – Johannes Martin Bijvoet
1954 – Ralph Wyckoff
1957 – Jean Wyart
1960 – Paul Peter Ewald
1963 – John Desmond Bernal
1966 – Kathleen Lonsdale, Nikolay Belov
1969 – André Guinier
1972 – Dorothy Hodgkin
1975 – Arne Magnéli
1978 – Norio Kato
1981 – Jerome Karle
1984 – Theo Hahn
1987 – Mario Nardelli
1990 – André Authier
1993 – Philip Coppens
1996 – Edward Neill Baker
1999 – Henk Schenk
2002 – William L. Duax
2005 – Yuji Ohashi
2008 – Sine Larsen
2011 – Gautam Radhakrishna Desiraju
2014 – Marvin L. Hackert
2017 – Sven Lidin
2021 – Hanna Dabkowska
2024 – Santiago García Granda
IUCr Symmetry notation
The IUCr notation is the notation for the symmetry group adopted by the International Union of Crystallography in 1952. It identifies members of the Wallpaper group with a 4 character name. First it has a P or C for primitive or centered groups. Groups are denoted by a number 1, 2, 3, 4, or 6 for the highest order of symmetry. Groups can have one or two reflections, denoted as vertical mirrors first (horizontal reflection), and horizontal second (vertical reflection). A simple reflection is denoted by an m (mirror), and a glide-reflection is denoted by a g. Place holder 1 denotes an orthogonal direction with no reflections.
See also
Acta Crystallographica
X-ray crystallography
Crystallography
International Year of Crystallography
Open Access Scholarly Publishers Association, of which IUCr is a member
British Crystallographic Association
American Crystallographic Association
German Crystallographic Society
French Crystallographic Association
Crystallographic Society of Japan
References
External links
International Union of Crystallography Home Page
Archival collections
International Union of Crystallography Paul Peter Ewald records, 1936-1967, Niels Bohr Library & Archives
Members of the International Council for Science
International scientific organizations
Crystallography organizations
Scientific organizations established in 1948
International organisations based in the United Kingdom
Organisations based in Cheshire
Members of the International Science Council | International Union of Crystallography | [
"Chemistry",
"Materials_science"
] | 929 | [
"Crystallography",
"Crystallography organizations"
] |
10,766,937 | https://en.wikipedia.org/wiki/Semiautomaton | In mathematics and theoretical computer science, a semiautomaton is a deterministic finite automaton having inputs but no output. It consists of a set Q of states, a set Σ called the input alphabet, and a function T: Q × Σ → Q called the transition function.
Associated with any semiautomaton is a monoid called the characteristic monoid, input monoid, transition monoid or transition system of the semiautomaton, which acts on the set of states Q. This may be viewed either as an action of the free monoid of strings in the input alphabet Σ, or as the induced transformation semigroup of Q.
In older books like Clifford and Preston (1967) semigroup actions are called "operands".
In category theory, semiautomata essentially are functors.
Transformation semigroups and monoid acts
A transformation semigroup or transformation monoid is a pair consisting of a set Q (often called the "set of states") and a semigroup or monoid M of functions, or "transformations", mapping Q to itself. They are functions in the sense that every element m of M is a map . If s and t are two functions of the transformation semigroup, their semigroup product is defined as their function composition .
Some authors regard "semigroup" and "monoid" as synonyms. Here a semigroup need not have an identity element; a monoid is a semigroup with an identity element (also called "unit"). Since the notion of functions acting on a set always includes the notion of an identity function, which when applied to the set does nothing, a transformation semigroup can be made into a monoid by adding the identity function.
M-acts
Let M be a monoid and Q be a non-empty set. If there exists a multiplicative operation
which satisfies the properties
for 1 the unit of the monoid, and
for all and , then the triple is called a right M-act or simply a right act. In long-hand, is the right multiplication of elements of Q by elements of M. The right act is often written as .
A left act is defined similarly, with
and is often denoted as .
An M-act is closely related to a transformation monoid. However the elements of M need not be functions per se, they are just elements of some monoid. Therefore, one must demand that the action of be consistent with multiplication in the monoid (i.e. ), as, in general, this might not hold for some arbitrary , in the way that it does for function composition.
Once one makes this demand, it is completely safe to drop all parenthesis, as the monoid product and the action of the monoid on the set are completely associative. In particular, this allows elements of the monoid to be represented as strings of letters, in the computer-science sense of the word "string". This abstraction then allows one to talk about string operations in general, and eventually leads to the concept of formal languages as being composed of strings of letters.
Another difference between an M-act and a transformation monoid is that for an M-act Q, two distinct elements of the monoid may determine the same transformation of Q. If we demand that this does not happen, then an M-act is essentially the same as a transformation monoid.
M-homomorphism
For two M-acts and sharing the same monoid , an M-homomorphism is a map such that
for all and . The set of all M-homomorphisms is commonly written as or .
The M-acts and M-homomorphisms together form a category called M-Act.
Semiautomata
A semiautomaton is a triple where is a non-empty set, called the input alphabet, Q is a non-empty set, called the set of states, and T is the transition function
When the set of states Q is a finite set—it need not be—, a semiautomaton may be thought of as a deterministic finite automaton , but without the initial state or set of accept states A. Alternately, it is a finite-state machine that has no output, and only an input.
Any semiautomaton induces an act of a monoid in the following way.
Let be the free monoid generated by the alphabet (so that the superscript * is understood to be the Kleene star); it is the set of all finite-length strings composed of the letters in .
For every word w in , let be the function, defined recursively, as follows, for all q in Q:
If , then , so that the empty word does not change the state.
If is a letter in , then .
If for and , then .
Let be the set
The set is closed under function composition; that is, for all , one has . It also contains , which is the identity function on Q. Since function composition is associative, the set is a monoid: it is called the input monoid, characteristic monoid, characteristic semigroup or transition monoid of the semiautomaton
Properties
If the set of states Q is finite, then the transition functions are commonly represented as state transition tables. The structure of all possible transitions driven by strings in the free monoid has a graphical depiction as a de Bruijn graph.
The set of states Q need not be finite, or even countable. As an example, semiautomata underpin the concept of quantum finite automata. There, the set of states Q are given by the complex projective space , and individual states are referred to as n-state qubits. State transitions are given by unitary n×n matrices. The input alphabet remains finite, and other typical concerns of automata theory remain in play. Thus, the quantum semiautomaton may be simply defined as the triple when the alphabet has p letters, so that there is one unitary matrix for each letter . Stated in this way, the quantum semiautomaton has many geometrical generalizations. Thus, for example, one may take a Riemannian symmetric space in place of , and selections from its group of isometries as transition functions.
The syntactic monoid of a regular language is isomorphic to the transition monoid of the minimal automaton accepting the language.
Literature
A. H. Clifford and G. B. Preston, The Algebraic Theory of Semigroups. American Mathematical Society, volume 2 (1967), .
F. Gecseg and I. Peak, Algebraic Theory of Automata (1972), Akademiai Kiado, Budapest.
W. M. L. Holcombe, Algebraic Automata Theory (1982), Cambridge University Press
J. M. Howie, Automata and Languages, (1991), Clarendon Press, .
Mati Kilp, Ulrich Knauer, Alexander V. Mikhalov, Monoids, Acts and Categories (2000), Walter de Gruyter, Berlin, .
Rudolf Lidl and Günter Pilz, Applied Abstract Algebra (1998), Springer,
References
Category theory
Semigroup theory
Finite automata | Semiautomaton | [
"Mathematics"
] | 1,472 | [
"Functions and mappings",
"Mathematical structures",
"Mathematical objects",
"Fields of abstract algebra",
"Algebraic structures",
"Category theory",
"Mathematical relations",
"Semigroup theory"
] |
10,767,147 | https://en.wikipedia.org/wiki/Lightning%20rocket | A lightning rocket is a rocket that unravels a conductor, such as a fine copper wire, as it ascends, to conduct lightning charges to the ground. Lightning strikes derived from this process are called "triggered lightning."
Design
A conducting lightning rod is grounded and positioned alongside the launch tube in communication with the conductive path to thereby control the time and location of a lightning strike from the thundercloud. The conductor trailed by the rocket can be either a physical wire, or column of ionized gas produced by the engine. A lightning rocket using solid propellant may have cesium salts added, which produces a conductive path when the exhaust gases are discharged from the rocket. In a liquid propellant rocket a solution of calcium chloride is used to form the conductive path.
The system consists of a specially designed launch pad with lightning rods and conductors attached. The launch pad is either controlled wirelessly or via pneumatic line to the control station to prevent the discharge traveling to the control equipment. The fine copper wire (more recently reinforced with kevlar) is attached to the ground and plays out from the rocket as it ascends. The initial strike follows this wire and is as a result unusually straight. As the wire is vaporized by the initial strike, subsequent strikes are more angular in nature and follow the ionization trail of the initial strike. Rockets of this type are used for both lightning research and lightning control.
Betts system
The Betts lightning rocket, patented by Robert E. Betts in 2003, consists of a rocket launcher that is in communication with a detection device that measures the presence of electrostatic and ionic change in close proximity to the rocket launcher that also fires the rocket. This system is designed to control the time and the location of a lightning strike. As the rocket flies to the thundercloud a liquid is expelled aft forming a column in the air of particles that are more electrically conductive than the surrounding air. In a similar fashion to the system employing a solid propellant as the conductive producer this conductive path conducts a lightning strike to ground to thereby control the time and location of a lightning strike from the thundercloud.
References
External links
July 25, 2002, triggered lightning video
Transient Response of a Tall Object to Lightning
Lightning | Lightning rocket | [
"Physics"
] | 460 | [
"Physical phenomena",
"Electrical phenomena",
"Lightning"
] |
10,767,533 | https://en.wikipedia.org/wiki/Journal%20of%20Environmental%20Engineering | The Journal of Environmental Engineering is a monthly engineering journal published by the American Society of Civil Engineers.
The main editor is Dionysios D. Dionysiou of University of Cincinnati.
The journal presents broad interdisciplinary information on the practice and status of research in environmental engineering science, systems engineering, and sanitation. Papers focus on engineering methods; impacts of wastewater collection and treatment; watershed contamination; environmental biology; nonpoint-source pollution on watersheds; air pollution and acid deposition; and solid waste management.
History
As one of ASCE's flagship journals which began publication in 1956, this journal's origin goes back to the publication of the first volume of Transactions of the American Society of Civil Engineers in 1892. Established originally as Journal of the Sanitary Engineering Division and renamed Journal of the Environmental Engineering Division in 1973, it acquired its current name in 1983.
Indexes
The journal is indexed in Google Scholar, Baidu, Elsevier (Ei Compendex), Clarivate Analytics (Web of Science), ProQuest, Civil engineering database, TRDI, OCLC (WorldCat), IET/INSPEC, Crossref, Scopus, and EBSCOHost.
References
External links
ASCE Library
Engineering journals
Environmental engineering
Sewerage
Systems engineering
Systems journals
Waste management journals
American Society of Civil Engineers academic journals
Academic journals established in 1956 | Journal of Environmental Engineering | [
"Chemistry",
"Engineering",
"Environmental_science"
] | 274 | [
"Systems engineering",
"Waste management journals",
"Chemical engineering",
"Water pollution",
"Sewerage",
"Environmental science journals",
"Civil engineering",
"Environmental engineering"
] |
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