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http://blog.sigfpe.com/2010_07_01_archive.html?m=0 | # A Neighborhood of Infinity
## Saturday, July 31, 2010
### Automatic Divided Differences
Divided Differences
I've previously talked about automatic differentiation here a few times. One of the standard arguments for using automatic differentiation is that it is more accurate than numeric differentiation implemented via divided differences. We can approximate f'(x) by using (f(x)-f(y))/(x-y) with a value of y near x. Accuracy requires y to be close to x, and that requires computing the difference between two numbers that are very close. But subtracting close numbers is itself a source of numerical error when working with finite precision. So you're doomed to error no matter how close you choose x and y to be.
However, the accuracy problem with computing divided differences can itself be fixed. In fact, we can adapt the methods behind automatic differentiation to work with divided differences too.
(This paragraph can be skipped. I just want to draw a parallel with what I said here. Firstly I need to correct the title of that article. I should have said it was about *divided differences*, not *finite differences*. The idea in that article was that the notion of a divided difference makes sense for types because for a large class of function you can define divided differences without using either differencing or division. You just need addition and multiplication. That's the same technique I'll be using here. I think it's neat to see the same trick being used in entirely different contexts.)
The Direct Approach
Firstly, here's a first attempt at divided differencing:
> diff0 f x y = (f x - f y)/(x - y)
We can try it on the function f:
> f x = (3*x+1/x)/(x-2/x)
diff0 f 1 1.000001 gives -14.0000350000029. Repeating the calculation with an arbitrary precision package (I used CReal) gives -14.000035000084000. We are getting nowhere near the precision we'd like when working with double precision floating point.
The Indirect Approach
Automatic differentiation used a bunch of properties of differentiation: linearity, the product rule and the chain rule. Similar rules hold for divided differences. First let me introduce some notation. If f is a function then I'll use f(x) for normal function application. But I'll use f[x,y] to mean the divided difference (f(x)-f(y))/(x-y). We have
(f+g)[x,y] = f[x,y]+g[x,y]
(fg)[x,y] = f(x)g[x,y]+f[x,y]g(y)
h[x,y] = f[g(x),g(y)]g[x,y] when h(x)=f(g(x))
We can modify the product rule to make it more symmetrical though it's not strictly necessary:
(fg)[x,y] = 0.5(f(x)+f(y))g[x,y]+0.5f[x,y] (g(x)+g(y))
(I got that from this paper by Kahan.)
In each case, given f evaluated at x and y, and its divided difference at [x, y], and the same for g, we can compute the corresponding quantities for the sum and product of f and g. So we can store f(x), f(y) and f[x,y] together in a single structure:
> data D a = D { fx :: a, fy :: a, fxy :: a } deriving (Eq, Show, Ord)
And now we can implement arithmetic on these structures using the rules above:
> instance Fractional a => Num (D a) where
> fromInteger n = let m = fromInteger n in D m m 0
> D fx fy fxy + D gx gy gxy = D (fx+gx) (fy+gy) (fxy+gxy)
> D fx fy fxy * D gx gy gxy = D (fx*gx) (fy*gy) (0.5*(fxy*(gx+gy) + (fx+fy)*gxy))
> negate (D fx fy fxy) = D (negate fx) (negate fy) (negate fxy)
I'll leave as an exercise the proof that this formula for division works:
> instance Fractional a => Fractional (D a) where
> fromRational n = let m = fromRational n in D m m 0
> D fx fy fxy / D gx gy gxy = D (fx/gx) (fy/gy) (0.5*(fxy*(gx+gy) - (fx+fy)*gxy)/(gx*gy))
For the identity function, i, we have i(x)=x, i(y)=y and i[x,y]=1. So for any x and y, the evaluation of the identity function at x, y and [x,y] is represented as D x y 1. To compute divided differences for any function f making use of addition, subtraction and division we need to simply apply f to D x y 1. We pick off the divided difference from the fxy element of the structure. Here's our replacement for diff0.
> diff1 f x y = fxy \$ f (D x y 1)
This is all mimicking the construction for automatic differentiation.
Evaluating diff0 f 1 1.000001 gives -14.000035000083997. Much closer to the result derived using CReal. One neat thing about this is that we have a function that's well defined even in the limit as x tends to y. When we evaluate diff1 f 1 1 we get the derivative of f at 1.
I thought that this was a novel approach but I found it sketched at the end of this paper by Reps and Rall. (Though their sketch is a bit vague so it's not entirely clear what they intend.)
Both the Kahan paper and the Reps and Rall papers give some applications of computing divided diferences this way.
It's not clear how to deal with the standard transcendental functions. They have divided differences that are very complex compared to their derivatives.
Aside
There is a sense in which divided differences are uncomputable(!) and that what we've had to do is switch from an extensional description of functions to an intensional description to compute them. I'll write about this some day.
Note that the ideas here can be extended to higher order divided differences and that there are some really nice connections with type theory. I'll try to write about these too.
Update: I found another paper by Reps and Rall that uses precisely the method described here.
## Saturday, July 03, 2010
### Death to Hydrae (or the operational semantics of ordinals)
Unprovable Propositions
Among other things, Godel's first incompleteness theorem allows us to construct a statement in the language of Peano arithmetic that can't be proved using the axioms of Peano arithmetic. Unfortunately, this statement is a highly contrived proposition whose sole purpose is to be unprovable. People who learn of Godel's theorems often ask if there are other more natural and uncontrived mathematical statements that can't be proved from the Peano axioms.
My goal in this post will be to describe one of these propositions. Not just uncontrived, but actually very useful. I only intend to tell half of the story here because I feel like there are many good treatments already out there that tell the rest. I'm just going to get to the point where I can state the unprovable proposition, and then sketch how it can be proved if you allow yourself a little Set Theory.
> {-# OPTIONS_GHC -fno-warn-missing-methods #-}> import Prelude hiding ((^))> infixr 8 ^> type Natural = Integer
Termination
Suppose we implement a function to compute the Fibonacci numbers like so:
> fib 0 = 0> fib 1 = 1> fib n = fib (n-2) + fib (n-1)
How do we know that fib terminates for all natural number arguments? One approach is this: if we pass in the argument n it clearly never recurses more than n levels. Each time it recurses it calls itself at most twice. So it must terminate in O(2n) steps (assuming that the primitive operations such as addition take constant time). We can think of this code in a kind of imperative way. It's a bit like n nested loops, each loop going round up to two times.
Suppose instead that we have some kind of recursive function g that goes n levels deep but for which the number of calls of g to itself is no longer two. In fact, suppose the number of self-calls is very large. Even worse, suppose that each time g is called, it calls itself many more times than it did previously, maybe keeping track of this ever growing number through a global variable. Or instead of a global variable, maybe an evil demon decides how many times g calls itself at each stage. Can you still be sure of termination?
A Simple Machine
In order to look at this question, we'll strip a computer right down to the bare minimum. It will have an input (that the evil demon could use) for natural numbers and will output only one symbol. Here's a design for such a machine:
> data Machine = Done | Output Machine | Input (Natural -> Machine)
A value of type Machine represents the state of the machine. Done means it has finished running. Output s means output a symbol and continue in state s. Input f means stop to input a number from the demon (or elsewhere), call it i, and then continue from state f i. This is very much in the style discussed by apfelmus and I in recent blog posts.
Here's an interpreter for one of these machines:
> run1 Done = return ()> run1 (Output x) = print "*" >> run1 x> run1 (Input f) = readLn >>= (run1 . f)
For any n we can easily build a machine to output n stars. This is such a natural machine to want to build it seems only right to give it the name n. If we want to do this then we need to make Machine an instance of Num and define fromInteger for it:
> instance Num Machine where> fromInteger 0 = Done> fromInteger n = Output (fromInteger (n-1))
Typing run1 8, say, will output 8 stars.
Now given two of these machines there is a natural notion of adding them. a + b is the machine that does everything b does followed by everything a does. (Remember, that's b then a.) To do this we need to dig into b and replace every occurrence of Done in it with a. That way, instead of finishing like b, it leads directly into a. In the case of a + Input f, for each number i we need to dig into f i replacing each Done with a:
> a + Done = a> a + Output b = Output (a + b)> a + Input f = Input (\i -> a + f i)
There's a natural way to multiply these machines too. The idea is that in a * b we run machine b. But each time the Output command is run, instead of printing a star it executes a. You can think of this as a control structure. If n is a natural number then a * n means running machine a n times. In the case of a * Input f, instead of multiplying by a fixed natural number, we get an input from the user and multiply by f i instead:
> _ * Done = Done> a * Output b = a*b + a> a * Input f = Input (\i -> a * f i)
We can make a machine to input a number and then output that many stars. Here it is:
> w = Input fromInteger
Try running run1 w.
Can you guess what the machine w * w does? Your first guess might be that it inputs two numbers and outputs as many stars as the product of the two numbers. Try it. What actually happens is that we're computing w * Input fromInteger. Immediately from the definition of * we get Input (\i -> w*i). In other words, the first input gives us an input i, and then w is run i times. So if we initially input i, we are then asked for i more inputs and after each input, the corresponding number of stars is output. Although the original expression contains just two occurrences of w, we are required to enter i+1 numbers.
Given the definitions of + and * it seems natural to define the power operation too:
> (^) :: Machine -> Machine -> Machine> a ^ Done = Output Done> a ^ Output b = a^b * a> a ^ Input f = Input (\i -> a ^ f i)
The power operation corresponds to the nesting of loops. So, for example, w ^ n can be thought of loops nested n deep.
Try working out what w ^ w does when executed with run1.
Consider the set M of all machines built using just a finite number of applications of the three operators +, * and ^ to w and the non-zero naturals. (The non-zero condition means we exclude machines like 0*w that accept an input and do nothing with it.) Any such expression can be written as f w, where the definition of f makes no mention of w.
Suppose we use run1 and we always enter the same natural n. Then each occurrence of w acts like n. So if we start with some expression in w, say f w, then always inputting n results in f n stars. We could test this with run1 (w^w^w^w), always entering 2, but it would require a lot of typing. Instead we can write another intepreter that consumes its inputs from a list rather from the user (or demon). And instead of printing stars it simply prints out the total number of stars at the end:
> run2 Done _ = 0> run2 (Output x) as = 1 + run2 x as> run2 (Input f) (a:as) = run2 (f a) as
Now you can try run2 (w^w^w^w) [2,2..] and see that we (eventually) get 2222.
Termination Again
If we run a machine in M there's a pattern that occurs again and again. We input a number, and then as a result we go into a loop requesting more numbers. These inputs may in turn request more inputs. Like the mythological hydra, every input we give may spawn many more requests for inputs. As the number of inputs required may depend on our previous inputs, and we may input numbers as large as we like, these machines may run for a long time. Suppose our machine terminates after requesting n inputs. Then there must be some highest number that we entered. Call it m. Then if the original machine was f w (with f defined in terms of the 3 operators and non-zero naturals), the machine must have terminated outputting no more than f m stars. So if our machine terminates, we can bound how many steps it took.
But do our machines always terminate? The input we give to the machine might not be bounded. If we run run2 (w^w) [4,5..], say, the inputs grow and grow. If these inputs grow faster than we can chop off the heads of our hydra, we might never reach termination.
Consider a program to input n and then output fib n. It accepts an input, recurses to a depth of at most n, and calls itself at most twice in each recursion. Compare with the machine 2 ^ w. This accepts an input n, recurses to a depth n, calling itself exactly twice each time. So if 2 ^ w terminates, so does fib. The more complex example above where I introduced the evil demon will terminate if w ^ w does, as long as the demon doesn't stop inputting numbers. So if we can show in one proof that every machine of type Machine terminates, then there are many programs whose termination we could easily prove.
Let's consider an example like run1 (w ^ w) with inputs 2, 3, 4, ...
We start with w ^ w. Examining the definition of the operator ^ we see that this proceeds by requesting an input. The first input is 2. Now we're left with w ^ 2. This is w * w. Again it accepts an input. This time 3. Now we go to state w * 3. This is w*2 + w. Again we accept an input. This time 4. We are led to w*2 + 4. This now outputs 4 stars and we are left with w * 2 which is w + w. We accept an input 5, output 5 stars and are left with w. After a further input of 6, it outputs 6 stars and terminates. Or we could just run run2 (w ^ w) [2,3..] and get 15(=4+5+6) as output.
The transitions are:
w ^ w
-> w ^ 2
-> w * w
-> w * 3
-> w*2 + w
-> w*2 + 4 -> ... -> w * 2
-> w + w
-> w + 5 -> ... w
-> 6 -> ... -> 0.
Now for some Set Theory. Rewrite the above sequence using the transfinite ordinal ω instead of w. The sequence becomes a sequence of ordinals. Any time we accept an input, the rightmost ω becomes a finite ordinal. So we have a descending sequence of ordinals. This is true whatever ordinal we start with. The execution of either Input or Output always strictly decreases our ordinal, and any descending sequence of ordinals must eventually terminate. Therefore every machine in M eventually terminates.
But here's the important fact: to show termination we used the ordinal ω, and this required the axiom of infinity and some Set Theory. Instead we could encode the termination question, via Godel numbering, as a proposition of Peano arithmetic. If we do this, then we hit against an amazing fact. It can't be proved using the axioms of Peano arithmetic. So we have here a useful fact, not a contrived self-referential one, that can't be proved with Peano arithmetic.
Why can't it be proved using just the Peano axioms?
A few years back, Jim Apple made a post about constructing (some) countable ordinals in Haskell. His construction nicely reflects the definitions a set theorist might make, but the code doesn't actually do anything. Later I learned from Hyland and Power how you can interpret algebraic structures as computational effects. apfelmus illustrates nicely how an abstract datatype can be made to do things with the help of an interpreter. Roughly speaking, doing this is what is known as operational semantics. So I thought, why not apply this approach to the algebraic rules for defining and combining ordinals. The result are the interpreters run1 and run2 above.
run1 gives an example of a Hydra game. In fact, its precisely the hydra game described in this paper because it always chops off the rightmost head. The Kirby-Paris theorem tells us we can't prove this game terminates using just the Peano axioms. A web search on Goodstein's theorem will reveal many great articles with the details.
A well-ordered quantity that you can keep decreasing as a program runs, and that can be used to prove termination, is an example of a loop variant. Loop variants are often natural numbers but the above shows that transfinite ordinals make fine loop variants. But in the interest of being fair and balanced, here's a dissenting view. The author has a point. If you are forced to use transfinite ordinals to show your program terminates, the age of the universe will probably be but the briefest flicker compared to your program's execution. On the other hand, if you don't want an actual bound on the execution time, ordinals can provide very short proofs of termination for useful programs.
> instance Show Machine> instance Eq Machine> instance Ord Machine | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7781461477279663, "perplexity": 1006.8982378021318}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2016-44/segments/1476988718426.35/warc/CC-MAIN-20161020183838-00495-ip-10-171-6-4.ec2.internal.warc.gz"} |
https://compmatsci.wordpress.com/2010/09/ | ## Crystallization kinetics and stress induced twinning/de-twinning
### September 24, 2010
F Liu et al
The crystallization kinetics of amorphous Zr50Al10Ni40, as measured by means of both isothermal and isochronal differential scanning calorimetry, were evaluated using a new procedure involving application of a modular analytical model to provide a complete description of the phase-transformation kinetics, in combination with a preceding analysis of the transformation-rate maximum. The power of detailed analysis of the position of the transformation-rate maximum, as a function of the transformed fraction, was demonstrated by identification of the operating impingement mode. On this basis, the kinetic parameters governing the crystallization kinetics could then be determined quantitatively using the modular analytical model. The crystallization governing mechanisms could be varied by appropriate control of the crystallization conditions. The results obtained are consistent with the microstructural evolution, as observed by transmission electron microscopy.
S Hu et al
Twinning in certain metals or under certain conditions is a major plastic deformation mode. Here we present a phase field model to describe twin formation and evolution in a polycrystalline fcc metal under loading and unloading. The model assumes that twin nucleation, growth and de-twinning is a process of partial dislocation nucleation and slip on successive habit planes. Stacking fault energies, energy pathways (γ surfaces), critical shear stresses for the formation of stacking faults and dislocation core energies are used to construct the thermodynamic model. The simulation results demonstrate that the model is able to predict the nucleation of twins and partial dislocations, as well as the morphology of the twin nuclei, and to reasonably describe twin growth and interaction. The twin microstructures at grain boundaries are in agreement with experimental observation. It was found that de-twinning occurs during unloading in the simulations, however, a strong dependence of twin structure evolution on loading history was observed.
## Some papers from scripta
### September 10, 2010
H Wei et al
Interdiffusion behavior of Ni3Al-Mo ternary system at 1423, 1473 and 1523 K were studied using Ni3Al/Ni3Al-Mo single-phase diffusion couples. The concentration dependent interdiffusion coefficients were calculated over whole diffusion range, and average ternary interdiffusion coefficients were carefully determined in the middle of the diffusion zone. These ternary coefficients were also examined to estimate tracer diffusion coefficients of Mo in Ni3Al phase. Furthermore, the results were utilized to explain the diffusion behavior of Mo in Ni3Al-based superalloys IC-6.
X Zhu and Y Xiang
In this paper, we study the glide force due to stress on the constituent dislocations of slightly perturbed symmetric low angle tilt boundaries. We show that the stabilizing force comes from both the long-range interaction of the constituent dislocations and their local line tension effect. We also present a continuum model for such glide force. The obtained results and continuum model provide a basis for further understanding of the stress-driven migration of distorted grain boundaries.
J A Sharon et al
Micro-tensile experiments and electron microscopy have been utilized to characterize the mechanical behavior of nanocrystalline Pt films. The behavior can be described as high strength with limited strain to failure. The tensile deformation triggers a microstructural evolution increasing the grain size from 20nm in the initial state to 33nm in the deformed state. This observation of grain growth at a homologous temperature of 0.146 provides further evidence of the role of mechanical stress in initiating grain growth in nanocrystalline metals.
H Xing et al
The evolution of morphology during directional solidification is investigated in terms of the interaction between bubbles and the solid–liquid interface. The results reveal that the solid phase grows along the bubble boundary to form solid envelopes and a liquid gap. As the interface velocity increases, the expansion coefficients of bubbles increase continually, and then decrease. The solidification microstructures of bubbles transform in the sequence water-drop→elongated→irregular with increasing interface velocity.
J W Elmer and E D Specht
Ag nanoink sintering kinetics and subsequent melting is studied using in situ synchrotron-based X-ray diffraction. Direct observations of Ag nanoink sintering on Cu demonstrate its potential for materials joining since the Ag nanoink sinters at low temperatures but melts at high-temperatures. Results show low expansion coefficient of sintered Ag, nonlinear expansion as Ag densifies and interdiffuses with Cu above 500 °C, remelting consistent with bulk Ag, and eutectic reaction with Cu. The results demonstrate the usefulness of Ag nanoink as a high-temperature bonding medium.
Magnetization and resistivity were measured as a function of temperature in polycrystalline Ni–Mn–Sn Heusler alloys with a magnetocrystalline first order phase transition. At external magnetic fields <0.2 T the magnetization change associated with the phase transition happened at a temperature up to not, vert, similar5 K lower than the true phase transition temperature measured by electrical resistivity or predicted by thermodynamic theory. We associate this anomaly with magnetic exchange coupling between austenite and martensite phases coexisting near the transition.
G Gottstein and L S Shvindlerman
The drag effect by second-phase particles on grain boundary motion is considered with regard to the triple line particle–grain boundary that is formed during the interaction between a particle and a grain boundary. A quantitative analysis of this effect has become possible due to recent measurements of the triple line energy. In the limit of large particles (dp > 50 nm) the particle is wet by the boundary (Zener approximation) whereas smaller particles are repelled by the grain boundary.
## Couple of papers from Acta
### September 10, 2010
Grain boundary evolution in copper bicrystals is investigated during uniaxial tension at 10 K. Grain boundary structures are generated using molecular statics employing an embedded atom method potential, followed by molecular dynamics simulation at a constant 1 × 109 s−1 strain rate. Interfacial free volume is continuously measured during boundary deformation, and its evolution is investigated both prior to and during grain boundary dislocation nucleation. Free volume provides valuable insight into atomic-scale processes associated with stress-induced grain boundary deformation. Different boundary structures are investigated in this work to analyze the role of interface structure, stress state and initial free volume on dislocation nucleation. The results indicate that the free volume influences interfacial deformation through modified atomic-scale processes, and grain boundaries containing particular free volume distributions show a greater propensity for collective atomic migration during inelastic deformation.
A first principles continuum analytical model for cationic segregation to the grain boundaries in complex ceramic oxides is presented. The model permits one to determine the electric charge density and the segregation-induced electric potential profiles through the grain and can be extrapolated to the range of nanostructured grain sizes. The theoretical predictions are compared with existing data for yttria-stabilized tetragonal zirconia polycrystals. The implications for physical properties (mainly high temperature plasticity and hardening behaviour) are then discussed.
## Rolling rubber bands, growing bacteria and corroding silicon wafers
### September 10, 2010
Three papers from PRL that discuss some interesting problems:
P S Raux et al
We present the results of a combined experimental and theoretical investigation of rolling elastic ribbons. Particular attention is given to characterizing the steady shapes that arise in static and dynamic rolling configurations. In both cases, above a critical value of the forcing (either gravitational or centrifugal), the ribbon assumes a two-lobed, peanut shape similar to that assumed by rolling droplets. Our theoretical model allows us to rationalize the observed shapes through consideration of the ribbon’s bending and stretching in response to the applied forcing.
[2] Morphology, Growth, and Size Limit of Bacterial Cells
H Jiang and S X Sun
Bacterial cells utilize a living peptidoglycan network (PG) to separate the cell interior from the surroundings. The shape of the cell is controlled by PG synthesis and cytoskeletal proteins that form bundles and filaments underneath the cell wall. The PG layer also resists turgor pressure and protects the cell from osmotic shock. We argue that mechanical influences alter the chemical equilibrium of the reversible PG assembly and determine the cell shape and cell size. Using a mechanochemical approach, we show that the cell shape can be regarded as a steady state of a growing network under the influence of turgor pressure and mechanical stress. Using simple elastic models, we predict the size of common spherical and rodlike bacteria. The influence of cytoskeletal bundles such as crescentin and MreB are discussed within the context of our model.
G Moras et al
We present a quantum-accurate multiscale study of how hydrogen-filled discoidal “platelet” defects grow inside a silicon crystal. Dynamical simulations of a 10-nm-diameter platelet reveal that H2 molecules form at its internal surfaces, diffuse, and dissociate at its perimeter, where they both induce and stabilize the breaking up of highly stressed silicon bonds. A buildup of H2 internal pressure is neither needed for nor allowed by this stress-corrosion growth mechanism, at odds with previous models. Slow platelet growth up to micrometric sizes is predicted as a consequence, making atomically smooth crystal cleavage possible in implantation experiments.
## Some recent papers from Acta
### September 4, 2010
A D Sheikh-Ali
Stress-induced behavior of high-angle near-coincidence symmetric tilt boundaries has been examined in bicrystal specimens of zinc. Parameters of coupling between boundary sliding and migration were determined. The angular deviation from the coincidence misorientation within the range of boundary specialness has a noticeable effect on the sliding-to-migration ratio, called “coupling factor”. Mechanisms of coupled boundary sliding and migration based on the motion of edge-type extrinsic and intrinsic grain boundary dislocations are discussed. It has been demonstrated that the observed alteration of the coupling factor with the change in boundary misorientation is due to the change of the parameters of extrinsic secondary grain boundary dislocations. The obtained results have also shown the limitation of the coincidence site lattice/displacement shift complete lattice model for the quantitative description of the structure of near-coincidence boundaries.
M Ohno and K Matsuura
The peritectic reaction process in carbon steel, L + δ → γ, has been analyzed by a quantitative phase-field simulation. The calculated moving velocities of the γ–L and γ–δ planar interfaces in the isothermal peritectic transformation precisely agree with the corresponding experimental data, which strongly supports the accuracy of the present simulation. The diffusion-controlled peritectic reaction rate and the growth velocity of the γ phase along the δ–L interface obtained by the present simulation were fairly consistent with the experimentally measured values. This indicates that recent experimental findings can be explained by a diffusion-controlled mechanism. This is in marked contrast to the claims made on the basis of the experimental data and an analytical model that the peritectic reaction is not controlled by the diffusion of carbon.
M Amoorezaei et al
We study spacing selection in directional solidification of Al–Cu alloys under transient growth conditions. New experimental results are presented which reveal that the mean dendritic spacing vs. solidification front speed exhibits plateau-like regions separated by regions of rapid change, consistent with previous experiments of Losert and co-workers. Quantitative phase-field simulations of directional solidification with dynamical growth conditions approximating those in the experiments confirm this behavior. The mechanism of this type of change in mean dendrite arm spacing is consistent with the notion that a driven periodically modulated interface must overcome an energy barrier before becoming unstable, in accord with a previous theory of Langer and co-workers.
C M Mueller and R Spolenak
Thin metal films can degrade into particles in a process known as dewetting. Dewetting proceeds in several stages, including void initiation, void growth and void coalescence. Branched void growth in thin Au films was studied by means of electron backscatter diffraction (EBSD). The holes were found to protrude into the film predominantly at high angle grain boundaries and the branched shape of the holes can be explained by surface energy minimization of the grains at the void boundaries. (1 1 1) Texture sharpening during dewetting was observed and quantified by EBSD and in situ X-ray studies.
Ti–Ni–Cu/SiO2 two layer diaphragm-type microactuators were fabricated by sputter deposition and micromachining. The influence of heat treatment temperature on the actuation behavior was investigated under quasi-static conditions. The interfacial structure of Ti–Ni–Cu/SiO2 and internal structure of the Ti–Ni–Cu layer were also investigated using transmission electron microscopy. The reaction layer formed between the Ti–Ni–Cu and SiO2 layers, and preferentially grew into the SiO2 side. The reaction layer formed at 1023 K mainly consisted of Ti4(Ni,Cu)2O. The maximum height of the diaphragm decreased with increasing heat treatment temperature. The growth of the reaction layer also affected the microstructure of the Ti–Ni–Cu layer. The density of fine platelets and Ti2Ni precipitates decreased with increasing heat treatment temperature from 873 to 923 K, and they disappeared at 973 K due to the fact that the reaction layer mainly consisted of a Ti-rich phase. The microactuator heat treated at 973 K showed the highest transformation temperature with the lowest transformation temperature hysteresis, which is attractive for high speed actuation. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.833430826663971, "perplexity": 2629.8603923771984}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-24/segments/1590347390437.8/warc/CC-MAIN-20200525223929-20200526013929-00405.warc.gz"} |
https://www.physicsforums.com/threads/couple-of-log-questions.284107/ | # Couple of log questions
1. Jan 10, 2009
1. The problem statement, all variables and given/known data
1.) 3logx2y + 2logxy
2.) 4logabc - 2loga2b - 3logbc
2. Relevant equations
3. The attempt at a solution
I know that 3logx2 is the same as 6logx but I don't know what to do since theres a y there
2. Jan 10, 2009
### snipez90
What is the question? If it's to simplify as much as possible, you can use log(xy) = log(x) + log(y).
3. Jan 10, 2009
Yep thats the question. I'm just confused about what to do with all these coefficients.
Is 3logx2y the same as logx6y3??
Can I write logx6y3 as logx6[/sup + log]y3 or do I have to get rid of them powers first?
4. Jan 10, 2009
### NoMoreExams
Yes assuming x^2y are both an argument of your log
5. Jan 10, 2009
### tiny-tim
I'm guessing that they want it in the form 6logx + 3logy.
(after all, how would you look up logx6 in log-tables if x = 2.345? … you'd have to find 2.3456 first, and the only way of doing that is to … yes!! )
6. Jan 10, 2009
Thanks a lot.
I have 2 more log questions in front of me that are confusing as hell too:
1.) log (x2 + 2) = 2.6
and
2.) 2x + 1 = 32x - 1
For the first one there I was wondering if I can express it like this 2logx + 2? Can I do that?
Last edited: Jan 10, 2009
7. Jan 10, 2009
### tiny-tim
Nooo … that woud be (logx2) +2
Hint: if loga = b, then a = eb
8. Jan 10, 2009
### jgens
Careful tiny-tim: log(a) doesn't necessarily refer to the natural logarithm. log(a) commonly refers to the logarithm base 10 as well.
9. Jan 10, 2009
### Delphi51
if log X = Y, then X = B^Y (where B is the base of the log)
If it doesn't make sense in logarithm land, transform it to power land!
And vice versa.
10. Jan 11, 2009
### kbaumen
Well, where I study lg is decimal logarithm, ln is natural logarithm and log refers to a logarithm with any other base which is shown in subscript right after the log symbol. For example log$$_{2}$$8 = 3 ( I don't know why, but using LaTex here shows a subscript as a superscript on my machine. The 2 is supposed to be as a subscript. I hope you get the idea), lg100 = 2 and ln(e$$^{2}$$) = 2.
11. Jan 11, 2009
### tiny-tim
Hi kbaumen!
You have to use "inline" LaTeX (typing "itex" instead of "tex") if you're inserting into a line of text (see just above) …
but it's much better, on this forum, to use the X2 or X2 tags (just above the reply box), especially since any LaTeX takes up a lot of space on the server.
12. Jan 11, 2009
### kbaumen
Oh. Thanks a lot for the explanation.
13. Jan 11, 2009
### HallsofIvy
Staff Emeritus
Then x2+ 2= a2.6 where "a" is the base of the logarithm (probably 10 or e).
Since there exponentials are to different bases, which cannot be converted to one another, there is no easy way to solve this equation.
14. Jan 11, 2009
I decided to plug in some random numbers and the first one I plugged in (1) happened to work. Since theres no simple way to solve it maybe thats what I was meant to do. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8313912153244019, "perplexity": 1957.1377986100413}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2016-50/segments/1480698541773.2/warc/CC-MAIN-20161202170901-00162-ip-10-31-129-80.ec2.internal.warc.gz"} |
https://physics.stackexchange.com/questions/26546/is-it-possible-to-look-into-the-beginning-of-the-universe?lq=1 | # Is it possible to look into the beginning of the Universe?
If we currently can look into some of the furthest stars, actually seeing the past
Isn't it conceivable that given enough distance we should be able to see
Parts of the Big Bang? If the Universe is endless, it means we should be able to see into its beginning.
Has this theory ever been presented ? Is there anyone looking in to this possibility ?
Omar is correct that the furthest back we can "see" is the Cosmic Microwave Background because before this time photons, the carriers of light, were "coupled" with the protons and neutrons (and before that quarks). As the universe cooled the photons were able to be freed and create the Cosmic Microwave Background we see today. However we can theoretically look farther back with other techniques.
As Nic mentioned, the CMB is not entirely isotropic, meaning it is not the same in all directions. Slight variations (generally less than one part in $10^5$) can indicate structure from the time of decoupling (sometimes called the time last scattering). This is known as the Saches-Wolfe effect. However one has to be careful because there is also some redshifting (making the photons loose energy and appear more "red") cause along the path from the surface of last scattering to us, known as the "integrated Saches Wolfe effect".
There are also other backgrounds that can be theoretically seen if we get more precise instruments:
There is a Cosmic Neutrino Background, which could provide us information about further back in time. This is because, while photons decoupled about 400,000 years after the big bang, neutrinos decoupled significantly earlier, perhaps just a few seconds. However, because they were emitted earlier, they are even more redshifted and low energy (the CMB is about 2.7 K, a CNB would be ~1.9K) and neutrinoes are significantly harder to detect anyway. So far the only extraterrestrial neutrinoes detected have been from the sun and SN 1987a (a supernova).
There is also a gravitational wave background. It is very difficult to detect this, particularly because we haven't been able to directly detect any gravitational wave from a distant source (LIGO's detections were very close by, cosmologically speaking). There was a proposed space mission called the Big Bang Observer, which was never approved due to budget and technical concerns, which might have detected these early gravitational waves. They would have been emitted even earlier, probably just after inflation some $10^{-32}$ seconds after the big bang. EDIT: Note that the BICEP2/Keck paper of course shows great evidence for the existence of these gravitational waves, but they are still an indirect" in that we see their effects on the cosmic microwave background as opposed to directly seeing the space-time variations they cause. EDIT 2: The BICEP2/Keck results were found to be inconclusive! It is still an open question in cosmology.
As far as looking back to $t=0$, that seems unlikely. To say for certain we would need a good quantum gravity theory to understand the uber-early (before $10^{-42}$ seconds) universe. Perhaps some very strange exotic particle could exist that would give us a "view" of this period.
EDIT 3: Updated LIGO results.
• Yeah....the CNB...speaking as a neutrino experimenter, right now we haven't got the first clue how to probe that. The energies are so low and the cross-sections so small (by our standards!) that nothing we use these days has a chance. – dmckee Dec 13 '11 at 2:58
• The inflation produced gravitational waves MIGHT be detectable in the "B-modes" of polarization of the CMB. Whether they are detectable depends on the details of the inflationary model. – FrankH Dec 13 '11 at 8:13
• The BICEP experiment has now reported a positive result using the method suggested by @FrankH here. – dmckee Apr 12 '14 at 15:39
The furthest back we can look is the Cosmic Microwave Background (CMB) radiation. It is not possible to observe any further back than that because prior to that the Universe was hot enough to only contain hydrogen plasma. This plasma (soup of electrons and protons) absorbed any photons therefore making the Universe opaque.
• There are inferences based on anisotropies in the CMB that allow us to picture early times. – Nic Dec 12 '11 at 11:26 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7418337464332581, "perplexity": 675.2471157526675}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-51/segments/1575540528457.66/warc/CC-MAIN-20191210152154-20191210180154-00055.warc.gz"} |
https://www.physicsforums.com/threads/simple-error-analysis.788111/ | # Simple error analysis
• #1
SalfordPhysics
69
1
## Homework Statement
A series of 5 measurements of Y are recorded with increasing X. (i.e. gradient has units Y/X)
The error in measurement of Y is ±0.05
The error in measurement of X is ±0.005.
How is the error in the gradient calculated?
## Homework Equations
- measurements[/B]
Y | X
0.2 | 0.23
0.3 | 0.27
0.5 | 0.31
0.6 | 0.38
0.8 | 0.42
## The Attempt at a Solution
I assumed that the error in the gradient a would given by the equation.
εa = √((εY)2 + (εX)2)
I was unsure however if it was given by the addition of the individual error in each measurement.
Thanks
• #2
Homework Helper
Gold Member
38,361
7,903
I really dislike questions like this. The distribution of the errors in the inputs is not stated. It seems that those who pose these questions expect you to interpret the given errors as some (unspecified but fixed) number of standard deviations in normal distributions. In practice, errors induced by reading instruments are closer to uniform distributions. That being the case, the error in Y/X will be a different distribution, and it is not clear what an answer of the form ±ε would mean.
Putting that aside, the formula you quote is for fractional errors. That is, if the actual error in Xi is εi then the fractional error is εi/Xi. Of course, this is only an approximation, and only works when εi is small compared with Xi.
• #3
Homework Helper
15,067
4,117
I understand Haru's dislike, but since this is something that probably happens to many students, perhaps a few questions and comments may be useful:
The big question is: what's this about? If Sal has more context, he/she can get more and better assistance. What are you varying, what are you measuring, where do the error estimates come from ? Are they statistical or are they systematic ?
Error estimates are usually pretty rough. 0.05 and 0.005 are testimony. There is a chance they are one half the least significant digit of some measuring instrument, in which case see Haru's comment.
Notation:
It's good practice to state errors (or rather: error estimates) to one decimal place (unless the first digit is 1, or unless there is a good reason to state more).
it's good practice to state measurement to the same number of decimal places as the estimated error. So here X, Y = 0.230, 0.20 etc. That the trailing digit is always zero is suspicious.
Experiments:
usually you vary something (the independent variable) and you measure something (the dependent variable). The varied quantity is probably measured too, like in this case. A simple plot shows the independent variable on the x-axis and the dependent variable on the y-axis. If there is a reason to expect linear behaviour you do a linear least squares analysis to find a slope and an intercept. Other theoretically expected behaviours may bring you to plot calculated values (square root, logarithm, etc.) to obtain an expected linear relationship.
Analysis: With the given information, I would do a linear least squares fit to estimate the slope and the error therein. I would be ignoring the error in X and I would feel justified to do so: it's ten times smaller than the error in Y so when things add up quadratically the one half percent wrong is much smaller than the error in the estimated errors: " √ ( 0.052 + 0.0052 ) = 0.05 "
• #4
SalfordPhysics
69
1
I made these values and data up to custom to my actual problem.
The experiment was zeeman splitting using a CCD. The data was recorded by the program, with ΔE (Y from before) recorded to 1 decimal place and B (X from before) recorded to 2 decimal places. Gradient was automatically plotted. I want to know what the error in it is and so just need to know what method
• #5
Homework Helper
15,067
4,117
Method is linear regression. Expressions are e.g. here (for error see here).
Otherwise, Excel has a Regression entry under Data | Data Analysis
What does "gradient was automatically plotted" mean ? You got a plot of the data and it showed Y = 3.0 * X - 0.5 ?
• #6
Homework Helper
Gold Member
38,361
7,903
I would be ignoring the error in X : it's ten times smaller than the error in Y
... as fractions of the X and Y values respectively.
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2K | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8655886054039001, "perplexity": 1176.3701315340747}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572833.95/warc/CC-MAIN-20220817032054-20220817062054-00755.warc.gz"} |
https://mathematica.stackexchange.com/questions/135648/unable-to-evaluate-the-limit-of-an-expression-at-infinity-with-assumptions-on-p | # Unable to evaluate the Limit of an expression at Infinity, with assumptions on parameters
I need some help in evaluating the following limit with assumptions:
Limit[Result, L -> Infinity, Assumptions -> A ∈ Integers && A > 0 &&
B ∈ Integers && B > 0 && C ∈ Integers && C > 0 && D > 0 && F > 0]
where
Result := C D (B F)^(A + L) (-C D + B F)^-A
((C D + B F)^(-1 - L) - ((-C D + B F)^(-1 - L)
Gamma[1 + A + L] Hypergeometric2F1[1 + L, 1 + A + L,
2 + L, -((C D + B F)/(-C D + B F))])/(Gamma[A] Gamma[2 + L]))
It should come out to 0, and I am sure of this. I just need to verify.
The reason is that I plugged in values for all of the parameters (except L), and then summed over Result from L=0 to L=100000 - the sum converges to 1.
Mathematica is unable to evaluate this limit as I defined it. Is there a proper way?
Thanks in advance for any help.
• Did you type this correctly? When I simplify this I get C D (B F)^(A+L) (-C D+B F)^-A. BTW, D is a predefined keyword for derivative. You may use some other variable. – Anjan Kumar Jan 18 '17 at 3:48
• I think I did type correctly... what did you simplify to get that !? – user10189 Jan 18 '17 at 3:50
• I just used Simplify[Result]. – Anjan Kumar Jan 18 '17 at 3:51
• Strange. I did not get that. I have version 10.4. – user10189 Jan 18 '17 at 3:52
• I noticed that in the code you have posted, there is a new line in the Result. This is the reason why it gives different results. – Anjan Kumar Jan 18 '17 at 4:04
It is convenient to replace C by a B F/D, where a > 0. Also, specify that L is positive.
Simplify[Result /. C -> a B F/D, B > 0 && F > 0 && a > 0 && L > 0]
(* (1 - a)^-A a B F (B F)^L (((1 + a) B F)^(-1 - L) - ((-(-1 + a) B F)^(-1 - L)
Gamma[1 + A + L] Hypergeometric2F1[1 + L, 1 + A + L, 2 + L,
(1 + a)/(-1 + a)])/(Gamma[A] Gamma[2 + L])) *)
It is not uncommon for Limit to fail when dealing with hypergeometric functions. So, use Series instead.
Series[%, {L, Infinity, 1}, Assumptions -> B > 0 && F > 0 && L > 0] // Normal
(* ((1 - a)^-A a (B F)^L ((1 + a) B F)^-L)/(1 + a) *)
FullSimplify[%, B > 0 && F > 0 && L > 0 && a > 0]
(* (1 - a)^-A a (1 + a)^(-1 - L) *)
Limit[%, L -> Infinity, Assumptions -> a > 0]
(* 0 *)
as desired.
• This is simply brilliant. My next step was to compute the series anyway! – user10189 Jan 18 '17 at 6:27 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8024386763572693, "perplexity": 1313.4767031999238}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-43/segments/1570986676227.57/warc/CC-MAIN-20191017200101-20191017223601-00151.warc.gz"} |
http://cs.felk.cvut.cz/en/news/detail/1221 | # News & Events
### CS seminar series - Jie Zhang
CS seminar series presents
Social Welfare in One-Sided Matchings: Game Analysis, Mechanism Design, and Applications
by Jie Zhang
Monday, May 2 at 14:30 in 205
Abstract:
We study the problem of approximate social welfare maximization (without money) in one-sided matching problems when agents have unrestricted cardinal preferences over a finite set of items. From the mechanism design perspective, we show that the folklore mechanism Random Priority is asymptotically the best truthful-in-expectation mechanism and the best ordinal mechanism for the problem. From the game analysis perspective, we present a general lower bound of $\Omega(\sqrt{n})$ on the Price of Anarchy, which applies to all mechanisms and we show that the Probabilistic Serial protocol achieves a matching upper bound. We discuss some applications and extensions of the problem. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.6085926294326782, "perplexity": 1550.5701973039074}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-17/segments/1492917122992.88/warc/CC-MAIN-20170423031202-00028-ip-10-145-167-34.ec2.internal.warc.gz"} |
https://developer.mozilla.org/ja/docs/Web/CSS/transform-function/scaleZ | # scaleZ()
The `scaleZ()` CSS function defines a transformation that resizes an element along the z-axis. Its result is a `<transform-function>` data type.
This scaling transformation modifies the z-coordinate of each element point by a constant factor, except when the scale factor is 1, in which case the function is the identity transform. The scaling is not isotropic, and the angles of the element are not conserved. `scaleZ(-1)` defines an axial symmetry, with the z-axis passing through the origin (as specified by the `transform-origin` property).
In the above interactive examples, `perspective: 550px;` (to create a 3D space) and `transform-style: preserve-3d;` (so the children, the 6 sides of the cube, are also positioned in the 3D space), have been set on the cube.
Note: `scaleZ(sz)` is equivalent to to `scale3d(1, 1, sz)`.
## Syntax
```scaleZ(s)
```
### Values
`s`
Is a `<number>` representing the scaling factor to apply on the z-coordinate of each point of the element.
Cartesian coordinates on ℝ2 Homogeneous coordinates on ℝℙ2 Cartesian coordinates on ℝ3 Homogeneous coordinates on ℝℙ3
This transformation applies to the 3D space and can't be represented on the plane. $\left(\begin{array}{cc}10& 0\\ 01& 0\\ 0& 0& s\end{array}\right)$ $\left(\begin{array}{ccc}10& 0& 0\\ 01& 0& 0\\ 0& 0& s& 0\\ 0& 0& 0& 1\end{array}\right)$
## Examples
### HTML
```<div>Normal</div>
<div class="perspective">Translated</div>
<div class="scaled-translated">Scaled</div>```
### CSS
```div {
width: 80px;
height: 80px;
background-color: skyblue;
}
.perspective {
/* Includes a perspective to create a 3D space */
transform: perspective(400px) translateZ(-100px);
background-color: limegreen;
}
.scaled-translated {
/* Includes a perspective to create a 3D space */
transform: perspective(400px) scaleZ(2) translateZ(-100px);
background-color: pink;
}
```
## Specifications
Specification Status Comment
CSS Transforms Level 2
The definition of 'scaleZ()' in that specification.
Editor's Draft Initial definition
## Browser compatibility
Please see the `<transform-function>` data type for compatibility info. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 2, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.6966997385025024, "perplexity": 1698.8953434448852}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-40/segments/1600400189264.5/warc/CC-MAIN-20200918221856-20200919011856-00358.warc.gz"} |
https://groupprops.subwiki.org/wiki/Moufang_implies_diassociative | # Moufang implies diassociative
This article gives the statement and possibly, proof, of an implication relation between two loop properties. That is, it states that every loop satisfying the first loop property (i.e., Moufang loop) must also satisfy the second loop property (i.e., diassociative loop)
View all loop property implications | View all loop property non-implications
## Statement
Any Moufang loop is a diassociative loop.
## Facts used
1. Moufang implies alternative: A Moufang loop is an alternative loop, i.e., it satisfies the left alternative law $x * (x * y) = (x * x) * y$ and the right alternative law $x * (y * y) = (x * y) * y$.
2. Moufang's theorem: This states that if $L$ is a Moufang loop, and $x,y,z$ are (not necessarily distinct) elements of $L$ such that $x * (y * z) = (x * y) * z$, then the subloop of $L$ generated by $x,y,z$ is a group, i.e., it is associative.
## Proof
Given: A Moufang loop $L$. Elements $x,y \in L$ (not necessarily distinct).
To prove: The subloop of $L$ generated by $x,y$ is associative.
Proof: Setting $z = y$, we see that by fact (1), $x * (y * z) = (x * y) * z$ (using the right alternative law part). Hence, by fact (2), the subloop generated by $x,y,z$ is a group. But since $z = y$, this is the same as the subloop generated by $x$ and $y$, completing the proof. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 18, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9788764119148254, "perplexity": 595.455979527937}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-45/segments/1603107878921.41/warc/CC-MAIN-20201022053410-20201022083410-00531.warc.gz"} |
https://www.esaral.com/q/let-e-g-and-n-represent-the-magnitudes-of-electromagnetic-26729/ | Let E, G and N represent the magnitudes of electromagnetic,
Question:
Let $E, G$ and $N$ represent the magnitudes of electromagnetic, gravitational and nuclear forces between two electrons at a given separation. Then
(a) $\mathrm{N}>\mathrm{E}>\mathrm{G}$
(b) $E>N>G$
(c) $\mathrm{G}>\mathrm{N}>\mathrm{E}$
(d) $E>G>N$
Solution:
(d) $E>G>N$ | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9957793951034546, "perplexity": 656.9958831868756}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-21/segments/1652662509990.19/warc/CC-MAIN-20220516041337-20220516071337-00317.warc.gz"} |
https://tobiasroth.github.io/BDAEcology/stan.html | # 18 MCMC using Stan
## 18.1 Background
Markov chain Monte Carlo (MCMC) simulation techniques were developed in the mid-1950s by physicists (Metropolis et al., 1953). Later, statisticians discovered MCMC (Hastings, 1970; Geman & Geman, 1984; Tanner & Wong, 1987; Gelfand et al., 1990; Gelfand & Smith, 1990). MCMC methods make it possible to obtain posterior distributions for parameters and latent variables (unobserved variables) of complex models. In parallel, personal computer capacities increased in the 1990s and user-friendly software such as the different programs based on the programming language BUGS (Spiegelhalter et al., 2003) came out. These developments boosted the use of Bayesian data analyses, particularly in genetics and ecology.
## 18.2 Install rstan
In this book we use the program Stan to draw random samples from the joint posterior distribution of the model parameters given a model, the data, prior distributions, and initial values. To do so, it uses the “no-U-turn sampler,” which is a type of Hamiltonian Monte Carlo simulation , and optimization-based point estimation. These algorithms are more efficient than the ones implemented in BUGS programs and they can handle larger data sets. Stan works particularly well for hierar- chical models . Stan runs on Windows, Mac, and Linux and can be used via the R interface rstan. Stan is automatically installed when the R package rstan is installed. For installing rstan, it is advised to follow closely the system-specific instructions.
## 18.3 Writing a Stan model
The statistical model is written in the Stan language and saved in a text file. The Stan language is rather strict, forcing the user to write unambiguous models. Stan is very well documented and the Stan Documentation contains a comprehensive Language Manual, a Wiki documentation and various tutorials.
We here provide a normal regression with one predictor variable as a worked example. The entire Stan model is as following (saved as linreg.stan)
data {
int<lower=0> n;
vector[n] y;
vector[n] x;
}
parameters {
vector[2] beta;
real<lower=0> sigma;
}
model {
//priors
beta ~ normal(0,5);
sigma ~ cauchy(0,5);
// likelihood
y ~ normal(beta[1] + beta[2] * x, sigma);
}
A Stan model consists of different named blocks. These blocks are (from first to last): data, transformed data, parameters, trans- formed parameters, model, and generated quantities. The blocks must appear in this order. The model block is mandatory; all other blocks are optional.
In the data block, the type, dimension, and name of every variable has to be declared. Optionally, the range of possible values can be specified. For example, vector[N] y; means that y is a vector (type real) of length N, and int<lower=0> N; means that N is an integer with nonnegative values (the bounds, here 0, are included). Note that the restriction to a possible range of values is not strictly necessary but this will help specifying the correct model and it will improve speed. We also see that each line needs to be closed by a column sign. In the parameters block, all model parameters have to be defined. The coefficients of the linear predictor constitute a vector of length 2, vector[2] beta;. Alternatively, real beta[2]; could be used. The sigma parameter is a one-number parameter that has to be positive, therefore real<lower=0> sigma;.
The model block contains the model specification. Stan functions can handle vectors and we do not have to loop over all observations as typical for BUGS . Here, we use a Cauchy distribution as a prior distribution for sigma. This distribution can have negative values, but because we defined the lower limit of sigma to be 0 in the parameters block, the prior distribution actually used in the model is a truncated Cauchy distribution (truncated at zero). In Chapter 10.2 we explain how to choose prior distributions.
Further characteristics of the Stan language that are good to know include: The variance parameter for the normal distribution is specified as the standard deviation (like in R but different from BUGS, where the precision is used). If no prior is specified, Stan uses a uniform prior over the range of possible values as specified in the parameter block. Variable names must not contain periods, for example, x.z would not be allowed, but x_z is allowed. To comment out a line, use double forward-slashes //.
## 18.4 Run Stan from R
We fit the model to simulated data. Stan needs a vector containing the names of the data objects. In our case, x, y, and N are objects that exist in the R console.
The function stan() starts Stan and returns an object containing MCMCs for every model parameter. We have to specify the name of the file that contains the model specification, the data, the number of chains, and the number of iterations per chain we would like to have. The first half of the iterations of each chain is declared as the warm-up. During the warm-up, Stan is not simulating a Markov chain, because in every step the algorithm is adapted. After the warm-up the algorithm is fixed and Stan simulates Markov chains.
library(rstan)
# Simulate fake data
n <- 50 # sample size
sigma <- 5 # standard deviation of the residuals
b0 <- 2 # intercept
b1 <- 0.7 # slope
x <- runif(n, 10, 30) # random numbers of the covariate
simresid <- rnorm(n, 0, sd=sigma) # residuals
y <- b0 + b1*x + simresid # calculate y, i.e. the data
# Bundle data into a list
datax <- list(n=length(y), y=y, x=x)
# Run STAN
fit <- stan(file = "stanmodels/linreg.stan", data=datax, verbose = FALSE)
##
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## Chain 4: | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8348414301872253, "perplexity": 7882.397412046087}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572127.33/warc/CC-MAIN-20220815024523-20220815054523-00762.warc.gz"} |
https://www.physicsforums.com/threads/current-does-not-always-choose-the-path-of-least-resistance.835077/ | # Current does not always choose the path of least resistance...?
1. Sep 29, 2015
### fog37
Hello Forum,
Electric current usually goes down the path of least resistance if it can. However, there are situations in which it prefers to go through a path of more resistance if the path of least resistance has no potential difference across.
Are my statements correct?
For example, see the circuit below where the current does not pass through the red segment of the circuit because it has no potential a difference across and could be removed without affecting the circuit:
thanks!
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2. Sep 29, 2015
### Jeff Rosenbury
Yes, your statement is correct. Current does not always follow the path of least resistance. Your example is a little misguided though.
Current travels in loops. so the entire loop resistance needs to be considered.
But suppose we have a 100Ω resistor in parallel with a 99Ω resistor. Some current will flow in each rather than all of it flowing in the path of least resistance, the 99Ω resistor.
(More will flow in the 99Ω than the 100Ω though.)
Also there are capacitance, inductance, and occasionally relativistic effects that affect the current flow.
3. Sep 29, 2015
### epenguin
It goes through all paths. Some goes through the bird perching on the high voltage electric supply cables. But it goes in the 'laziest' way possible, it goes in such a way that it heats (aka dissipates energy) the least possible, given the constraints. So it mostly goes through the cable not the bird. There was a thread about it by a guy who discovered this (not the first unfortunately) here. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8219282031059265, "perplexity": 840.460643330089}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-30/segments/1531676593051.79/warc/CC-MAIN-20180722061341-20180722081341-00116.warc.gz"} |
https://osf.io/q6sxh/ | ## Experiment 1
Contributors:
Date created: | Last Updated:
: DOI | ARK
Category: Data
### Wiki
Instructions for Use This component contains the data and analysis scripts for Experiment 1 reported in our Journal of Neurophysiology paper. Contents: Exp1_SubjectExclusionLog is a record of which subjects were excluded from our final sample (and were therefore replaced). SpatialWM_LongDelay.m is the script used to run the experiment (this script requires PsychToolbox; see http://psychtoolbox.org... | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9810269474983215, "perplexity": 9490.391389123115}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-39/segments/1568514573065.17/warc/CC-MAIN-20190917081137-20190917103137-00318.warc.gz"} |
http://www.thespectrumofriemannium.com/2017/07/17/log192-bits-on-black-holes-i/?shared=email&msg=fail | LOG#192. Bits on black holes (I).
Hi, doctorish ladies and gentlemen!
I am going to teach some bits of black hole today. For the simplest static (non-rotatory) black hole, the whole space-time is fully specified by mass , and some constants, like . The critical radius for a black hole is the Schwarzschild radius
The black hole area, assuming space-time, reads
And the surface gravity at the event horizon is written as follows
It is very interesting that this surface gravity is, in fact, the maximal force guessed by the maximal force follower, divided by the black hole mass, i.e., . Surface gravity creates tides with units equal to:
The celebrated Bekenstein-Hawking area formula for the entropy is, as you already know if you follow my blog:
with units in . A note I have never done before: entropy from Boltzmann formula has dimensions of , energy divided by absolute temperature. Using Shannon definition, you get
using units of nats. Nats are equal to shannons (Sh) or hartleys, bans or dits. And 1 hartley is bit = nats. Therefore, you can express the BH entropy in terms of , hartleys, or shannons (i.e., bits or dits as well!). Hawking’s biggest discovery was the black hole temperature, that fixed the factor in the area law from the Bekenstein’s biggest discovery, the analogy between black holes and thermodynamics:
And, moreover, since black holes behave as blackbodies, they radiate! As they radiate, they become smalles (I am neglecting accretion, of course, from the macro-world) and they explote. The evaporation time for black holes is
and the black hole luminosity from a pure blackbody reads
from a BH flux
As the luminosity is power, or rate of change of energy:
with becomes
or
so
and thus ( is the Planck mass, and is a solar mass)
or
The black hole power or luminosity reads
for a solar mass black hole becomes
A Planck mass BH evaporates in about . For a solar mass BH, you need about . Primordial BH, born in the early universe withe evaporating time about , evaporating by now, has to be about . However, taking the cosmic microwave background (CMB) temperature, and equating it to the Hawking temperature, you obtain a bound about . Black holes as dark matter (primordial black holes. PMB) have been proposed. The interesting window of mass is
Even more,…If you add extra dimensions of space, e.g. extra space-like dimension, and you define the fundamental scale of gravity as and not , then you have that the evaporating time for a higher dimensional BH scales as follows
Interesingly, the limit and are “the same”, excepting by the diffusion of gravitational flux through .
Black hole species have sizes:
1. Micro BH. Mass about the moon mass. Radius about 0.1mm.
2. Stellar BH. Mass up to tens of solar masses. Radius about 30km or a few hundreds of km.
3. Intermediate mass BH. Yet to be discovered but hinted since LIGO GW detections and other clues. Masses since hundreds of solar masses up to almost a million of solar masses. Radii are variable. It is about Earth radius for a thousand solar mass BH.
4. Supermassive BH. From millions to billions or more (there are people arguing about an upper bound on BH mass) of solar masses. Radii are between 0.001 and 200 AU (astronomical units).
There are other types of black holes: extremal (superextremal), type D, with cosmological constant, primordial, … Mechanisms for BH production in laboratory and/or astrophysical scenarios are also interesting. Even their simulation via analogue fluid systems or quantum computing! For Kerr or Kerr-Newmann black holes, the following bound is known
in Planck units. The equivalence between the Hawking process, the Unruh radiation and the Schwinger mechanism is also curious. Another interesting radius for BH systems are:
the photon sphere and the inner stable circular orbit radius, respectively. And
are the Hawking and Unruh temperatures in natural units. Check what is the condition to both formulae to give the same number. Do you know what is the fastest way to get the correct BH entropy formula using basic thermodynamics. Know the Hawking temperature in natural units . Knowing this, you can fix the number in BH from thermodynamics:
so
You only get the right formula if you put by hand an extra factor. Indeed, in extra dimensions, you also get:
More on extra dimensional p-branes, not directly black holes but alike. The tension for a p-brane reads
and the YM coupling
The Dirac-Nambu action
Note, that M-theory fixes in some way. Black branes are BH-like solutions in superstring/M-theory. In extra dimensions, the newtonian gravitational law reads off as follows
(1)
where the omega is the surface area of the unit sphere
Kerr (rotating, uncharged) BH are interesting. Collide two of these Kerr BH. They will emit energy in form of electromagnetic, gravitational or any other form of radiation. The maximal efficiency is known to be (due to Hawking himself):
Charged BH are worst for efficiency process in BH thermodynamics. Hawking knows this from his paper, Gravitational radiation from colliding black holes. Rotating BH has a Hawking temperature
where is the Kerr parameter. Take yourself a few Planck absements, , in order to guess that the right formula for the power of Kerr BH is
For a Kerr-Newmann BH (rotating, charged), the power is
To end this post, and to prepare you for the follow up post, let me speculate a little bit about BH “are” or “we think they are”:
• Black holes are spacetime, rotating or not, charged or not, but they are highly curved space-time fully specified by some parameters or numbers.
• Quantum BH or at least semi-classical BH has a temperature and they evaporate. If you take this as serious, the own space-time does decay, at least, highly curved space-time.
• BH have microstates, but we don’t know for sure what they are.
That entropy of any BH seems to scale like area and not like volume, is sometimes refferred as the holographic principle. BH entropy seems to be non-extensive. Indeed, this suggests a link with condensed matter. Or even with solid state theory. Are BH “materials”? Of course, since matter and energy are equivalent when you are using relativity, they should. That charges of BH are on the boundary, it seems, and not on the full volume seems to be something like topological insulators or superconductors. The quantum theory of space-time is yet to be built. Is it a world crystal like P. Jizba and collaborators suggest? A crystal is any highly ordered microscopic structure with lattices extending in all directions of space. However, solids are generally much more complex. Polycrystals are many crystals bonded or fused together. Is space-time or a BH a polycrystal? The classification of solids in crystalline, polycrystalline and amorphous could be also useful in BH physics! Polymorphism implies many crystals or phases. There are allotropy and polyamorphism as well. Furthermore, if you extend these thoughts to quasi-crystals, you get a bigger picture of black holes. Quasicrystals are non periodic “ordered” arrays of atoms. Could BH be quasicrystals? The International Union of Crystallography (IUC) defines crystal in a very general fashion. Its definition contains ordinary periodic discrete crystals, quasicrystals, and any other system showing some periodic diffraction diagram/pattern. Crystallinity itself is any structural order material, solid of material system. This definition paves the way towards topological ordered systems. It yields and correlates with hardness, density, transparency, diffusion and other material features. Crystalites or grains are the basic pieces (atoms) of polycrystals or polycrystalline matter. There are also materials “in between” crystals and amorphous materials. They are called paracrystals. More precisely, paracrystals are short medium range ordering lattice material, similar to liquid crystal phases, but lacking ordering in one direction at least. Geologists admit, today, four levels of crystallinity:
1. Holocrystalline.
2. Hypocrystalline.
3. Hypohyaline.
4. Holohyaline.
Open question: could you guess a way to classify BH solutions with certain geological dictionary? I did it. And it is lot of fun! Let me know if you arrive to some conclusion like me.
Open question (II): the Hagedorn temperature is the temperature beyond string theory ceases to have sense. The degrees of freedom have to be redefined beyond that point. Dimensionally, check that
When is Hagedorn temperature equal to Planck temperature? Could they be different? Following the same arguments, calculate the temperature of a gas of branes and its Hagedorn temperature.
See you in my next blog post!
Epilogue:
View ratings | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8535307049751282, "perplexity": 2135.544292520658}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-09/segments/1550247481122.31/warc/CC-MAIN-20190216210606-20190216232606-00281.warc.gz"} |
http://www.r-bloggers.com/tag/latex/page/4/ | # Posts Tagged ‘ LaTex ’
## Sorting out Sweave in Eclipse/StatET
November 29, 2010
By
Using Sweave to produce pretty-looking documentation for R is awfully handy. It takes a little tweaking to get set up in Eclipse and StatET though. I followed the information in Jeromy Anglim’s webpage to originally get Sweave set up. The followi...
## Sweave Tutorial 1: Using Sweave, R, and Make to Generate a PDF of Multiple Choice Questions
November 26, 2010
By
In this post I present an example of using Sweave to prepare a PDF of formatted multiple choice questions.More broadly the example shows how to use Sweave to incorporate elements of a databaseinto a formatted LaTeX document.It aims to be useful to any...
## Robust adaptive Metropolis algorithm [arXiv:10114381]
November 23, 2010
By
Matti Vihola has posted a new paper on arXiv about adaptive (random walk) Metropolis-Hastings algorithms. The update in the (lower diagonal) scale matrix is where is the current acceptance probability and the target acceptance rate; is the current random noise for the proposal, ; is a step size sequence decaying to zero. The spirit of
## Animated plots in R and LaTeX
October 12, 2010
By
I like to use animated plots in my talks on functional time series, partly because it is the only way to really see what is going on with changes in the shapes of curves over time, and also because audiences love them! Here is how it is done. For LaTeX, you need to create every
## Export R data to tex code
October 12, 2010
By
We often use Gnu R to work on different things and to solve various exercises. It's always a disgusting job to export e.g. a matrix with probabilities to a LaTeX document to send it to our supervisors, but Rumpel just gave me a little hint.
## Creating a Presentation with LaTeX Beamer – Including Images from Graphics Files
August 7, 2010
By
It will often be more efficient to generate graphics in an external software package and then include these files in a LaTeX beamer presentation. The standard LaTeX approach to including graphics can be utilised to perform this task. Fast Tube by Casper The graphicx is useful for including graphics files in a presentation and this package has
## Creating a Presentation with LaTeX Beamer – Equations and tikz
July 23, 2010
By
Many presentations created using LaTeX beamer included mathematical equations and these can be easily included in a presentation and in this post we will consider using the tikz package to add various interesting elements to equations, such as lines between text on a slide and part of an equation. Fast Tube by Casper The examples on this
## Creating a Presentation with LaTeX Beamer – Boxes
July 19, 2010
By
We can add coloured boxes with text or mathematics into a LaTeX beamer presentation which is particularly useful if we have definitions, theorem or computer code to highlight this information that may not be so accessible within a paragraph of text. Fast Tube by Casper The easiest way to create a box is to use the various
## More StackExchange sites
July 16, 2010
By
The StackExchange site on Statistical Analysis is about to go into private beta testing. This is your last chance to commit if you want to be part of the private beta testing. Don’t worry if you miss out — it will only be a week before it is then open to the public. There is | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.819452166557312, "perplexity": 1948.0285226193414}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-49/segments/1416931007510.17/warc/CC-MAIN-20141125155647-00113-ip-10-235-23-156.ec2.internal.warc.gz"} |
http://mathhelpforum.com/pre-calculus/4909-plotting-graph-trigonometric-function-print.html | # Plotting a graph - Trigonometric Function
• August 14th 2006, 10:01 AM
c00ky
Plotting a graph - Trigonometric Function
Hi Again guys,
I've been told that the following problem can be solved on excel fairly easily... but i'm unsure what i should do with it.
Could anybody guide me through the solution so i can practice some examples?
Here is a screenshot of the problem:
Thanks
• August 14th 2006, 10:15 AM
ThePerfectHacker
1 Attachment(s)
You have,
$4\cos \left( x +\frac{\pi}{4} \right)$
That means, you will draw your regular cosine curve having an amplitute of 4 and the shift it to the left.
First draw the regular cosine of amplitude of 4. (dotted line)
Then use it to help you draw the real curve move to the left of $\pi/4$ (red line).
• August 14th 2006, 01:26 PM
c00ky
Thanks, that looks a little complicated though Perfect Hacker.. the examples we did at college on excel looked a little more simple.
I briefly remember we had a table of values on the excel spreadsheet, and then we had a graph which looked similar to the answer which was removed from this thread.
• August 14th 2006, 04:07 PM
Quick
1 Attachment(s)
Quote:
Originally Posted by c00ky
Thanks, that looks a little complicated though Perfect Hacker.. the examples we did at college on excel looked a little more simple.
I briefly remember we had a table of values on the excel spreadsheet, and then we had a graph which looked similar to the answer which was removed from this thread.
I removed my answer becuase I wasn't certain if my excel is set to radians or degrees.
I've reposted it below, you can decide.
• August 14th 2006, 04:09 PM
topsquark
Quote:
Originally Posted by Quick
I removed my answer becuase I wasn't certain if my excel is set to radians or degrees.
I've reposted it below, you can decide.
For the record, all trig functions in Excel assume the argument is in radians. The inverse functions all give answers in terms of radians.
-Dan
• August 14th 2006, 07:33 PM
CaptainBlack
Quote:
Originally Posted by Quick
I removed my answer becuase I wasn't certain if my excel is set to radians or degrees.
I've reposted it below, you can decide.
I can't read the attachment!
RonL
• August 14th 2006, 07:45 PM
CaptainBlack
1 Attachment(s)
Quote:
Originally Posted by c00ky
Hi Again guys,
I've been told that the following problem can be solved on excel fairly easily... but i'm unsure what i should do with it.
Could anybody guide me through the solution so i can practice some examples?
Here is a screenshot of the problem:
Thanks
Something like:
• August 15th 2006, 10:24 AM
c00ky
So when V = 2.... x = ????
If you plot the graph over 360 degrees there are two answers..
I'm lost!
• August 15th 2006, 11:12 PM
Glaysher
Both answers are correct and if you left the oscillator on you would continue to get two additional answers every 360 degrees
Oh and for those having trouble with Excel try Autograph, designed by mathematicians for teaching mathematicians. I think its pretty good and at college we're stuck with the older version without 3D graphing Get a 30 day trial from here:
http://www.autograph-math.com/
• August 16th 2006, 12:03 AM
CaptainBlack
Quote:
Originally Posted by Glaysher
Both answers are correct and if you left the oscillator on you would continue to get two additional answers every 360 degrees
Oh and for those having trouble with Excel try Autograph, designed by mathematicians for teaching mathematicians. I think its pretty good and at college we're stuck with the older version without 3D graphing Get a 30 day trial from here:
http://www.autograph-math.com/
The advantage of Excel is that it is a very common piece of software
and you are likely to meet it on most PCs you encounter. I would normally
never recommend a piece of commercial software for mathematical work,
but the solver in Excel is a killer application and I use it all the time.
(Commercial software is a strange concept, at home I run MS Office 95
under XP, which I bought a number of years ago for £5 of off e-bay)
Other than common tools like Office (though even here OpenOffice would
almost be a viable alternative if it weren’t for the Excel solver) I would never
recommend commercial software for teaching or research for Maths. The free
products are good and cheap.
RonL
• August 16th 2006, 12:13 AM
Glaysher
Fair enough. I don't know many free ones though. The only one I've got is a wonderfully simple program that allows you to create graph paper to stick in other programs such as Word. I don't like Excel for little things really, like not drawing histograms properly.
• August 16th 2006, 12:21 AM
CaptainBlack
Quote:
Originally Posted by Glaysher
Fair enough. I don't know many free ones though. The only one I've got is a wonderfully simple program that allows you to create graph paper to stick in other programs such as Word. I don't like Excel for little things really, like not drawing histograms properly.
I've forgotten what its called but look for what ThePerfectHacker uses
it looks pretty good and is free. There is a link to its web page somewhere
in his posts (better still just wait till he reads this, I bet he posts the link | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 2, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5376852750778198, "perplexity": 1471.4365176090284}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-35/segments/1440644063881.16/warc/CC-MAIN-20150827025423-00326-ip-10-171-96-226.ec2.internal.warc.gz"} |
https://mathoverflow.net/questions/266624/asymptotics-of-bessel-functions | # Asymptotics of Bessel functions
With $J_n$ standing for the Bessel function of first kind, $n\in \mathbb N$, I define $$f_n (\rho) =\int_0^π J_n(\rho \sin \theta) \sin \theta \ d\theta.$$ Assuming $1\ll\rho\ll n$, I would like to find an equivalent of $f_n(\rho)$. Is it a straightforward consequence of the known expansions?
• $f_n(\rho) = \pi J_{\frac{n-1}{2}}(\rho/2) J_{\frac{n+1}{2}}(\rho/2)$ may help. – Robert Israel Apr 7 '17 at 22:05
We could just take the large-$n$ asymptotic of $J_n(z)\rightarrow (2\pi n)^{-1/2}(ez/2n)^n$, and then
$$f_n(\rho)\rightarrow \frac{1}{n}(\tfrac{1}{2}e\rho/n)^n.$$
This seems to be quite reasonable in the desired range $1\ll\rho\ll n$:
blue is the exact result, gold is the asymptotic expression, plotted as a function of $n$ for fixed $\rho=10$.
Given Robert Israel's result, the large-n expansion for $f_n(\rho)$ is just going to be an order-by-order multiplication of terms from the large-n Bessel expansions, and unless a dramatic simplification occurs, they are going to be complicated and onerous, too. I suggest you do the first two terms and see. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9608403444290161, "perplexity": 256.18569061675703}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-16/segments/1585370493121.36/warc/CC-MAIN-20200328225036-20200329015036-00362.warc.gz"} |
https://www.konglongib.com/author/konglongib_sotlqj/ | ## 4. test problem 4
Welcome to your test problem 4
$\int_0^1xdx = ?$
## 3. test problem 3
Welcome to your test problem 3
1 + 1 = ?
There is an island filled with grass and trees and plants. The only inhabitants are 100 lions and 1 sheep.
The lions are special:
1) They are infinitely logical, smart, and completely aware of their surroundings.
2) They can survive by just eating grass (and there is an infinite amount of grass on the island).
3) They prefer of course to eat sheep.
4) Their only food options are grass or sheep.
Now, here's the kicker:
5) If a lion eats a sheep he TURNS into a sheep (and could then be eaten by other lions).
6) A lion would rather eat grass all his life than be eaten by another lion (after he turned into a sheep).
Assumptions:
1) Assume that one lion is closest to the sheep and will get to it before all others. Assume that there is never an issue with who gets to the sheep first. The issue is whether the first lion will get eaten by other lions afterwards or not.
2) The sheep cannot get away from the lion if the lion decides to eat it.
3) Do not assume anything that hasn't been stated above.
So now the question:
Will that one sheep get eaten or not and why?
## 2. Distance
What is the distance from the origin to the plane 2x+3y+4z=12?
## 1. Tiger and sheep
There is an island filled with grass and trees and plants. The only inhabitants are 100 lions and 1 sheep.
The lions are special:
1) They are infinitely logical, smart, and completely aware of their surroundings.
2) They can survive by just eating grass (and there is an infinite amount of grass on the island).
3) They prefer of course to eat sheep.
4) Their only food options are grass or sheep.
Now, here's the kicker:
5) If a lion eats a sheep he TURNS into a sheep (and could then be eaten by other lions).
6) A lion would rather eat grass all his life than be eaten by another lion (after he turned into a sheep).
Assumptions:
1) Assume that one lion is closest to the sheep and will get to it before all others. Assume that there is never an issue with who gets to the sheep first. The issue is whether the first lion will get eaten by other lions afterwards or not.
2) The sheep cannot get away from the lion if the lion decides to eat it.
3) Do not assume anything that hasn't been stated above.
So now the question:
Will that one sheep get eaten or not and why? | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.33320537209510803, "perplexity": 2114.6828210190993}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-51/segments/1544376827175.38/warc/CC-MAIN-20181216003916-20181216025916-00086.warc.gz"} |
https://www.physicsforums.com/threads/double-slit-experiment-and-wavelengths.317840/ | # Double slit experiment and wavelengths
1. Jun 3, 2009
### brunettegurl
1. The problem statement, all variables and given/known data
A double-slit experiment is performed with light of wavelength 558.0 nm. The bright interference fringes are spaced 1.84 mm apart on the viewing screen. What will the fringe spacing be if the light is changed to a wavelength of 335.0 nm?
2. Relevant equations
d= $$\frac{\lambda * L}{spacing}$$
3. The attempt at a solution
so our assumption is that everything stays constant while only the wavelength changes and the fringe spacing..right?? i am unable to think ahead of this point ..pls. help
2. Jun 3, 2009
### brunettegurl
nevermind i made a silly error while trying to set up a ration btw the 2 wavelengths and distances
Similar Discussions: Double slit experiment and wavelengths | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9255699515342712, "perplexity": 1065.5046646816168}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-43/segments/1508187822966.64/warc/CC-MAIN-20171018123747-20171018143747-00229.warc.gz"} |
https://mathoverflow.net/questions/163117/roots-of-unity-near-1-in-z-p-z/163123 | # Roots of unity near 1 in Z / p Z
Let $r \ge 3$ be a fixed integer. I'm interested in primes p such that no integer in the interval $(-\sqrt{p}, \sqrt{p})$, except $1$ (and $-1$ if $r$ is even), is an r-th root of unity modulo p.
The naive heuristic that $r$-th roots of unity should be "randomly distributed" suggests that there should be infinitely many such primes, and indeed they should have density 1 among all primes. Can this be made rigorous?
• Suppose $r=3$, so that we are looking at roots of $x^2+x+1$. Then this seems like it should follow immediately from results on uniform distribution of solutions to quadratic congruences mod $p$; see imrn.oxfordjournals.org/content/2000/14/719.abstract Apr 11 '14 at 15:36
• Yes, it definitely does, and $r=4,r=6$ as well. Apr 11 '14 at 15:38
OK, thinking a little more clearly about this... (hopefully) Say $p\le N$ fails to have the property you want. Then $p | n^r-1$ for some $|n| < \sqrt{p} \le \sqrt{N}$. There are only $O(\sqrt{N})$ integers of the form $n^r-1$ with $n$ in this range, and each has only $O(\log{N})$ prime factors. So there are only $O(\sqrt{N} \log{N})$ exceptional primes $p \leq N$, which is tiny compared to $\pi(N)$.
• Sweet! So this shows in fact that I could replace $(-\sqrt{p}, \sqrt{p})$ with any interval of the form $(-p^{\delta}, p^\delta)$ with $\delta < 1$ (which seems reasonable). Apr 11 '14 at 16:26 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9617618322372437, "perplexity": 151.89542467128368}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-49/segments/1637964358323.91/warc/CC-MAIN-20211127223710-20211128013710-00132.warc.gz"} |
https://worldwidescience.org/topicpages/l/luminous+blue+variables.html | #### Sample records for luminous blue variables
1. Active Luminous Blue Variables in the Large Magellanic Cloud
Energy Technology Data Exchange (ETDEWEB)
Walborn, Nolan R. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Gamen, Roberto C.; Lajús, Eduardo Fernández [Instituto de Astrofísica de La Plata, CONICET–UNLP and Facultad de Ciencias Astronómicas y Geofísicas, UNLP, Paseo del Bosque s/n, La Plata (Argentina); Morrell, Nidia I. [Las Campanas Observatory, Carnegie Observatories, Casilla 601, La Serena (Chile); Barbá, Rodolfo H. [Departamento de Física y Astronomía, Universidad de La Serena, Cisternas 1200 Norte, La Serena (Chile); Angeloni, Rodolfo, E-mail: walborn@stsci.edu, E-mail: rgamen@fcaglp.unlp.edu.ar, E-mail: eflajus@fcaglp.unlp.edu.ar, E-mail: nmorrell@lco.cl, E-mail: rbarba@dfuls.cl, E-mail: rangelon@gemini.edu [Gemini Observatory, Colina El Pino, Casilla 603, La Serena (Chile)
2017-07-01
We present extensive spectroscopic and photometric monitoring of two famous and currently highly active luminous blue variables (LBVs) in the Large Magellanic Cloud (LMC), together with more limited coverage of three further, lesser known members of the class. R127 was discovered as an Ofpe/WN9 star in the 1970s but entered a classical LBV outburst in or about 1980 that is still in progress, thus enlightening us about the minimum state of such objects. R71 is currently the most luminous star in the LMC and continues to provide surprises, such as the appearance of [Ca ii] emission lines, as its spectral type becomes unprecedentedly late. Most recently, R71 has developed inverse P Cyg profiles in many metal lines. The other objects are as follows: HDE 269582, now a “second R127” that has been followed from Ofpe/WN9 to A type in its current outburst; HDE 269216, which changed from late B in 2014 to AF in 2016, its first observed outburst; and R143 in the 30 Doradus outskirts. The light curves and spectroscopic transformations are correlated in remarkable detail and their extreme reproducibility is emphasized, both for a given object and among all of them. It is now believed that some LBVs proceed directly to core collapse. One of these unstable LMC objects may thus oblige in the near future, teaching us even more about the final stages of massive stellar evolution.
2. Active Luminous Blue Variables in the Large Magellanic Cloud
Science.gov (United States)
Walborn, Nolan R.; Gamen, Roberto C.; Morrell, Nidia I.; Barbá, Rodolfo H.; Fernández Lajús, Eduardo; Angeloni, Rodolfo
2017-07-01
We present extensive spectroscopic and photometric monitoring of two famous and currently highly active luminous blue variables (LBVs) in the Large Magellanic Cloud (LMC), together with more limited coverage of three further, lesser known members of the class. R127 was discovered as an Ofpe/WN9 star in the 1970s but entered a classical LBV outburst in or about 1980 that is still in progress, thus enlightening us about the minimum state of such objects. R71 is currently the most luminous star in the LMC and continues to provide surprises, such as the appearance of [Ca II] emission lines, as its spectral type becomes unprecedentedly late. Most recently, R71 has developed inverse P Cyg profiles in many metal lines. The other objects are as follows: HDE 269582, now a “second R127” that has been followed from Ofpe/WN9 to A type in its current outburst; HDE 269216, which changed from late B in 2014 to AF in 2016, its first observed outburst; and R143 in the 30 Doradus outskirts. The light curves and spectroscopic transformations are correlated in remarkable detail and their extreme reproducibility is emphasized, both for a given object and among all of them. It is now believed that some LBVs proceed directly to core collapse. One of these unstable LMC objects may thus oblige in the near future, teaching us even more about the final stages of massive stellar evolution.
3. Active Luminous Blue Variables in the Large Magellanic Cloud
International Nuclear Information System (INIS)
Walborn, Nolan R.; Gamen, Roberto C.; Lajús, Eduardo Fernández; Morrell, Nidia I.; Barbá, Rodolfo H.; Angeloni, Rodolfo
2017-01-01
We present extensive spectroscopic and photometric monitoring of two famous and currently highly active luminous blue variables (LBVs) in the Large Magellanic Cloud (LMC), together with more limited coverage of three further, lesser known members of the class. R127 was discovered as an Ofpe/WN9 star in the 1970s but entered a classical LBV outburst in or about 1980 that is still in progress, thus enlightening us about the minimum state of such objects. R71 is currently the most luminous star in the LMC and continues to provide surprises, such as the appearance of [Ca ii] emission lines, as its spectral type becomes unprecedentedly late. Most recently, R71 has developed inverse P Cyg profiles in many metal lines. The other objects are as follows: HDE 269582, now a “second R127” that has been followed from Ofpe/WN9 to A type in its current outburst; HDE 269216, which changed from late B in 2014 to AF in 2016, its first observed outburst; and R143 in the 30 Doradus outskirts. The light curves and spectroscopic transformations are correlated in remarkable detail and their extreme reproducibility is emphasized, both for a given object and among all of them. It is now believed that some LBVs proceed directly to core collapse. One of these unstable LMC objects may thus oblige in the near future, teaching us even more about the final stages of massive stellar evolution.
4. Confirmation of the Luminous Blue Variable Status of MWC 930
Directory of Open Access Journals (Sweden)
A. S. Miroshnichenko
2014-01-01
Full Text Available We present spectroscopic and photometric observations of the emission-line star MWC 930 (V446 Sct during its long-term optical brightening in 2006–2013. Based on our earlier data we suggested that the object has features found in Luminous Blue Variables (LBV, such as a high luminosity (~3 105 L⊙, a low wind terminal velocity (~140 km s−1, and a tendency to show strong brightness variations (~1 mag over 20 years. For the last ~7 years it has been exhibiting a continuous optical and near-IR brightening along with a change of the emission-line spectrum appearance and cooling of the star’s photosphere. We present the object’s V-band light curve, analyze the spectral variations, and compare the observed properties with those of other recognized Galactic LBVs, such as AG Car and HR Car. Overall we conclude the MWC 930 is a bona fide Galactic LBV that is currently in the middle of an S Dor cycle.
5. MN112: a new Galactic candidate luminous blue variable
Science.gov (United States)
Gvaramadze, V. V.; Kniazev, A. Y.; Fabrika, S.; Sholukhova, O.; Berdnikov, L. N.; Cherepashchuk, A. M.; Zharova, A. V.
2010-06-01
We report the discovery of a new Galactic candidate luminous blue variable (cLBV) via detection of an infrared circular nebula and follow-up spectroscopy of its central star. The nebula, MN112, is one of many dozens of circular nebulae detected at 24μm in the Spitzer Space Telescope archival data, whose morphology is similar to that of nebulae associated with known (c)LBVs and related evolved massive stars. Specifically, the core-halo morphology of MN112 bears a striking resemblance to the circumstellar nebula associated with the Galactic cLBV GAL079.29+00.46, which suggests that both nebulae might have a similar origin and that the central star of MN112 is an LBV. The spectroscopy of the central star showed that its spectrum is almost identical to that of the bona fide LBV PCygni, which also supports the LBV classification of the object. To further constrain the nature of MN112, we searched for signatures of possible high-amplitude (>~1mag) photometric variability of the central star using archival and newly obtained photometric data covering a 45-yr period. We found that the B magnitude of the star was constant within error margins, while in the I band the star brightened by ~=0.4mag during the last 17 yr. Although the non-detection of large photometric variability leads us to use the prefix candidate' in the classification of MN112, we remind the readers that the long-term photometric stability is not unusual for genuine LBVs and that the brightness of PCygni remained relatively stable during the last three centuries. Partially based on observations collected at the German-Spanish Astronomical Center, Calar Alto, jointly operated by the Max-Planck-Institut für Astronomie Heidelberg and the Instituto de Astrofísica de Andalucía (CSIC). E-mail: vgvaram@mx.iki.rssi.ru (VVG); akniazev@saao.ac.za (AYK); fabrika@sao.ru (SF); olga@sao.ru (OS); berdnik@sai.msu.ru (LNB); cher@sai.msu.ru (AMC); alla@sai.msu.ru (AVZ)
6. The nature of the nebula associated with the luminous blue variable star WRA 751
OpenAIRE
Hutsemekers, Damien; van Drom, E.
1991-01-01
Narrow-band filter imagery as well as medium to high resolution spectroscopy of the nebula surrounding the luminous blue variable (LBV) star WRA 751 are presented. The nebula appears as a slowly expanding H II region of low excitation characterized by a significant N/O overabundance which may be due to the presence in the nebula of nuclear processed material ejected by the star. With the recent discovery of a nebula around HR Car, all but one known galactic LBVs are now shown to be associated...
7. New Galactic Candidate Luminous Blue Variables and Wolf-Rayet Stars
Science.gov (United States)
Stringfellow, Guy S.; Gvaramadze, Vasilii V.; Beletsky, Yuri; Kniazev, Alexei Y.
2012-04-01
We have undertaken a near-infrared spectral survey of stars associated with compact mid-IR shells recently revealed by the MIPSGAL (24 μm) and GLIMPSE (8 μm) Spitzer surveys, whose morphologies are typical of circumstellar shells produced by massive evolved stars. Through spectral similarity with known Luminous Blue Variable (LBV) and Wolf-Rayet (WR) stars, a large population of candidate LBVs (cLBVs) and a smaller number of new WR stars are being discovered. This significantly increases the Galactic cLBV population and confirms that nebulae are inherent to most (if not all) objects of this class.
8. Discovery of a new Galactic bona fide luminous blue variable with Spitzer★
Science.gov (United States)
Gvaramadze, V. V.; Kniazev, A. Y.; Berdnikov, L. N.; Langer, N.; Grebel, E. K.; Bestenlehner, J. M.
2014-11-01
We report the discovery of a circular mid-infrared shell around the emission-line star Wray 16-137 using archival data of the Spitzer Space Telescope. Follow-up optical spectroscopy of Wray 16-137 with the Southern African Large Telescope revealed a rich emission spectrum typical of the classical luminous blue variables (LBVs) like P Cygni. Subsequent spectroscopic and photometric observations showed drastic changes in the spectrum and brightness during the last three years, meaning that Wray 16-137 currently undergoes an S Dor-like outburst. Namely, we found that the star has brightened by ≈1 mag in the V and Ic bands, while its spectrum became dominated by Fe II lines. Taken together, our observations unambiguously show that Wray 16-137 is a new member of the family of Galactic bona fide LBVs.
9. Discovery of a new bona fide luminous blue variable in Norma
Science.gov (United States)
Gvaramadze, V. V.; Kniazev, A. Y.; Berdnikov, L. N.
2015-12-01
We report the results of optical spectroscopy of the candidate evolved massive star MN44 revealed via detection of a circular shell with the Spitzer Space Telescope. First spectra taken in 2009 May-June showed the Balmer lines in emission as well as numerous emission lines of iron, which is typical of luminous blue variables (LBVs) near the visual maximum. New observations carried out in 2015 May-September detected significant changes in the spectrum, indicating that the star became hotter. We found that these changes are accompanied by significant brightness variability of MN44. In particular, the Ic-band brightness decreased by ≈ 1.6 mag during the last six years and after reaching its minimum in 2015 June has started to increase. Using archival data, we also found that the Ic-band brightness increased by ≈3 mag in ≈30 yr preceding our observations. MN44 therefore represents the 17th known example of the Galactic bona fide LBVs. We detected a nitrogen-rich knot to the north-west of the star, which might represent an interstellar cloudlet interacting with the circumstellar shell. We discuss a possible association between MN44 and the INTEGRAL transient source of hard X-ray emission IGR J16327-4940, implying that MN44 might be either a colliding-wind binary or a high-mass X-ray binary.
10. MN48: a new Galactic bona fide luminous blue variable revealed by Spitzer and SALT
Science.gov (United States)
Kniazev, A. Y.; Gvaramadze, V. V.; Berdnikov, L. N.
2016-07-01
In this paper, we report the results of spectroscopic and photometric observations of the candidate evolved massive star MN48 disclosed via detection of a mid-infrared circular shell around it with the Spitzer Space Telescope. Follow-up optical spectroscopy of MN48 with the Southern African Large Telescope (SALT) carried out in 2011-2015 revealed significant changes in the spectrum of this star, which are typical of luminous blue variables (LBVs). The LBV status of MN48 was further supported by photometric monitoring which shows that in 2009-2011 this star has brightened by ≈0.9 and 1 mag in the V and Ic bands, respectively, then faded by ≈1.1 and 1.6 mag during the next four years, and apparently started to brighten again recently. The detected changes in the spectrum and brightness of MN48 make this star the 18th known Galactic bona fide LBV and increase the percentage of LBVs associated with circumstellar nebulae to more than 70 per cent. We discuss the possible birth place of MN48 and suggest that this star might have been ejected either from a putative star cluster embedded in the H II region IRAS 16455-4531 or the young massive star cluster Westerlund 1.
11. Long-term spectroscopic monitoring of the Luminous Blue Variable AG Carinae
Science.gov (United States)
Stahl, O.; Jankovics, I.; Kovács, J.; Wolf, B.; Schmutz, W.; Kaufer, A.; Rivinius, Th.; Szeifert, Th.
2001-08-01
We have extensively monitored the Luminous Blue Variable AG Car (HD 94910) spectroscopically. Our data cover the years 1989 to 1999. In this period, the star underwent almost a full S Dor cycle from visual minimum to maximum and back. Over several seasons, up to four months of almost daily spectra are available. Our data cover most of the visual spectral range with a high spectral resolution (lambda /Delta lambda ~ 20 000). This allows us to investigate the variability in many lines on time scales from days to years. The strongest variability occurs on a time scale of years. Qualitatively, the variations can be understood as changes of the effective temperature and radius, which are in phase with the optical light curve. Quantitatively, there are several interesting deviations from this behaviour, however. The Balmer lines show P Cygni profiles and have their maximum strength (both in equivalent width and line flux) after the peak of the optical light curve, at the descending branch of the light curve. The line-width during maximum phase is smaller than during minimum, but it has a local maximum close to the peak of the visual light curve. We derive mass-loss rates over the cycle from the Hα line and find the highest mass loss rates (log dot {M}/({M}_sun yr-1) ~ -3.8, about a factor of five higher than in the minimum, where we find log dot {M}/({M}_sun yr-1) ~ -4.5) after the visual maximum. Line-splitting is very commonly observed, especially on the rise to maximum and on the descending branch from maximum. The components are very long-lived (years) and are probably unrelated to similar-looking line-splitting events in normal supergiants. Small apparent accelerations of the components are observed. The change in radial velocity could be due to successive narrowing of the components, with the absorption disappearing at small expansion velocities first. In general, the line-splitting is more likely the result of missing absorption at intermediate velocities than of
12. Discovery of two new Galactic candidate luminous blue variables with Wide-field Infrared Survey Explorer
Science.gov (United States)
Gvaramadze, V. V.; Kniazev, A. Y.; Miroshnichenko, A. S.; Berdnikov, L. N.; Langer, N.; Stringfellow, G. S.; Todt, H.; Hamann, W.-R.; Grebel, E. K.; Buckley, D.; Crause, L.; Crawford, S.; Gulbis, A.; Hettlage, C.; Hooper, E.; Husser, T.-O.; Kotze, P.; Loaring, N.; Nordsieck, K. H.; O'Donoghue, D.; Pickering, T.; Potter, S.; Romero Colmenero, E.; Vaisanen, P.; Williams, T.; Wolf, M.; Reichart, D. E.; Ivarsen, K. M.; Haislip, J. B.; Nysewander, M. C.; LaCluyze, A. P.
2012-04-01
We report the discovery of two new Galactic candidate luminous blue variable (LBV) stars via detection of circular shells (typical of confirmed and candidate LBVs) and follow-up spectroscopy of their central stars. The shells were detected at 22 μm in the archival data of the Mid-Infrared All Sky Survey carried out with the Wide-field Infrared Survey Explorer (WISE). Follow-up optical spectroscopy of the central stars of the shells conducted with the renewed Southern African Large Telescope (SALT) showed that their spectra are very similar to those of the well-known LBVs P Cygni and AG Car, and the recently discovered candidate LBV MN112, which implies the LBV classification for these stars as well. The LBV classification of both stars is supported by detection of their significant photometric variability: one of them brightened in the R and I bands by 0.68 ± 0.10 and 0.61 ± 0.04 mag, respectively, during the last 13-18 years, while the second one (known as Hen 3-1383) varies its B, V, R, I and Ks brightnesses by ≃0.5-0.9 mag on time-scales from 10 d to decades. We also found significant changes in the spectrum of Hen 3-1383 on a time-scale of ≃3 months, which provides additional support for the LBV classification of this star. Further spectrophotometric monitoring of both stars is required to firmly prove their LBV status. We discuss a connection between the location of massive stars in the field and their fast rotation, and suggest that the LBV activity of the newly discovered candidate LBVs might be directly related to their possible runaway status. a USNO B-1 (Monet et al. 2003); bDENIS; c2MASS; dSALT; ePROMPT.
13. The Search for New Luminous Blue Variable Stars: Near-Infrared Spectroscopy of Stars With 24 micron Shells
Science.gov (United States)
2010-02-01
Luminous Blue Variable (LBV) stars represent an extremely rare class of very luminous and massive stars. Only about a dozen confirmed Galactic LBV stars are known to date, which precludes us from determining a solid evolutionary connection between LBV and other intermediate (e.g. Ofpe/WN9, WNL) phases in the life of very massive stars. The known LBV stars each have their own unique properties, so new discoveries add insight into the properties and evolutionary status of LBVs and massive stars; even one new discovery of objects of this type could provide break-through results in the understanding of the intermediate stages of massive star evolution. We have culled a prime sample of possible LBV candidates from the Spitzer 24 (micron) archival data. All have circumstellar nebulae, rings, and shells (typical of LBVs and related stars) surrounding reddened central stars. Spectroscopic followup of about two dozen optically visible central stars associated with the shells from this sample showed that they are either candidate LBVs, late WN-type Wolf-Rayet stars or blue supergiants. We propose infrared spectroscopic observations of the central stars for a large fraction (23 stars) of our northern sample to determine their nature and discover additional LBV candidates. These stars have no plausible optical counterparts, so infrared spectra are needed. This program requires two nights of Hale time using TripleSpec.
14. An ultraviolet study of B[e] stars: evidence for pulsations, luminous blue variable type variations and processes in envelopes
Science.gov (United States)
Krtičková, I.; Krtička, J.
2018-06-01
Stars that exhibit a B[e] phenomenon comprise a very diverse group of objects in a different evolutionary status. These objects show common spectral characteristics, including the presence of Balmer lines in emission, forbidden lines and strong infrared excess due to dust. Observations of emission lines indicate illumination by an ultraviolet ionizing source, which is key to understanding the elusive nature of these objects. We study the ultraviolet variability of many B[e] stars to specify the geometry of the circumstellar environment and its variability. We analyse massive hot B[e] stars from our Galaxy and from the Magellanic Clouds. We study the ultraviolet broad-band variability derived from the flux-calibrated data. We determine variations of individual lines and the correlation with the total flux variability. We detected variability of the spectral energy distribution and of the line profiles. The variability has several sources of origin, including light absorption by the disc, pulsations, luminous blue variable type variations, and eclipses in the case of binaries. The stellar radiation of most of B[e] stars is heavily obscured by circumstellar material. This suggests that the circumstellar material is present not only in the disc but also above its plane. The flux and line variability is consistent with a two-component model of a circumstellar environment composed of a dense disc and an ionized envelope. Observations of B[e] supergiants show that many of these stars have nearly the same luminosity, about 1.9 × 105 L⊙, and similar effective temperatures.
15. A new interpretation of luminous blue stars
International Nuclear Information System (INIS)
Stothers, R.
1976-01-01
16. Nature versus nurture: Luminous blue variable nebulae in and near massive stellar clusters at the galactic center
International Nuclear Information System (INIS)
Lau, R. M.; Herter, T. L.; Adams, J. D.; Morris, M. R.
2014-01-01
Three luminous blue variables (LBVs) are located in and near the Quintuplet Cluster at the Galactic center: the Pistol Star, G0.120-0.048, and qF362. We present imaging at 19, 25, 31, and 37 μm of the region containing these three LBVs, obtained with SOFIA using FORCAST. We argue that Pistol and G0.120-0.048 are identical 'twins' that exhibit contrasting nebulae due to the external influence of their different environments. Our images reveal the asymmetric, compressed shell of hot dust surrounding the Pistol Star and provide the first detection of the thermal emission from the symmetric, hot dust envelope surrounding G0.120-0.048. However, no detection of hot dust associated with qF362 is made. Dust and gas composing the Pistol nebula are primarily heated and ionized by the nearby Quintuplet Cluster stars. The northern region of the Pistol nebula is decelerated due to the interaction with the high-velocity (2000 km s –1 ) winds from adjacent Wolf-Rayet Carbon (WC) stars. From fits to the spectral energy distribution (SED) of the Pistol nebula with the DustEM code we determine that the Pistol nebula is composed of a distribution of very small, transiently heated grains (10 to ∼ 35 Å) having a total dust mass of 0.03 M ☉ , and that it exhibits a gradient of decreasing grain size from south to north due to differential sputtering by the winds from the WC stars. The total IR luminosity of the Pistol nebula is 5.2 × 10 5 L ☉ . Dust in the G0.120-0.048 nebula is primarily heated by the central star; however, the nebular gas is ionized externally by the Arches Cluster. Unlike the Pistol nebula, the G0.120-0.048 nebula is freely expanding into the surrounding medium. A grain size distribution identical to that of the non-sputtered region of the Pistol nebula satisfies the constraints placed on the G0.120-0.048 nebula from DustEM model fits to its SED and implies a total dust mass of 0.021 M ☉ . The total IR luminosity of the G0.120-0.048 nebula is
17. Nature versus nurture: Luminous blue variable nebulae in and near massive stellar clusters at the galactic center
Energy Technology Data Exchange (ETDEWEB)
Lau, R. M.; Herter, T. L.; Adams, J. D. [Astronomy Department, 202 Space Sciences Building, Cornell University, Ithaca, NY 14853-6801 (United States); Morris, M. R. [Department of Physics and Astronomy, University of California, Los Angeles, 430 Portola Plaza, Los Angeles, CA 90095-1547 (United States)
2014-04-20
Three luminous blue variables (LBVs) are located in and near the Quintuplet Cluster at the Galactic center: the Pistol Star, G0.120-0.048, and qF362. We present imaging at 19, 25, 31, and 37 μm of the region containing these three LBVs, obtained with SOFIA using FORCAST. We argue that Pistol and G0.120-0.048 are identical 'twins' that exhibit contrasting nebulae due to the external influence of their different environments. Our images reveal the asymmetric, compressed shell of hot dust surrounding the Pistol Star and provide the first detection of the thermal emission from the symmetric, hot dust envelope surrounding G0.120-0.048. However, no detection of hot dust associated with qF362 is made. Dust and gas composing the Pistol nebula are primarily heated and ionized by the nearby Quintuplet Cluster stars. The northern region of the Pistol nebula is decelerated due to the interaction with the high-velocity (2000 km s{sup –1}) winds from adjacent Wolf-Rayet Carbon (WC) stars. From fits to the spectral energy distribution (SED) of the Pistol nebula with the DustEM code we determine that the Pistol nebula is composed of a distribution of very small, transiently heated grains (10 to ∼ 35 Å) having a total dust mass of 0.03 M {sub ☉}, and that it exhibits a gradient of decreasing grain size from south to north due to differential sputtering by the winds from the WC stars. The total IR luminosity of the Pistol nebula is 5.2 × 10{sup 5} L {sub ☉}. Dust in the G0.120-0.048 nebula is primarily heated by the central star; however, the nebular gas is ionized externally by the Arches Cluster. Unlike the Pistol nebula, the G0.120-0.048 nebula is freely expanding into the surrounding medium. A grain size distribution identical to that of the non-sputtered region of the Pistol nebula satisfies the constraints placed on the G0.120-0.048 nebula from DustEM model fits to its SED and implies a total dust mass of 0.021 M {sub ☉}. The total IR luminosity of the G
18. Luminous and Variable Stars in M31 and M33. IV. Luminous Blue Variables, Candidate LBVs, B[e] Supergiants, and the Warm Hypergiants: How to Tell Them Apart
Energy Technology Data Exchange (ETDEWEB)
Humphreys, Roberta M.; Gordon, Michael S.; Hahn, David [Minnesota Institute for Astrophysics, 116 Church Street SE, University of Minnesota, Minneapolis, MN 55455 (United States); Martin, John C. [University of Illinois Springfield, Springfield, IL 62703 (United States); Weis, Kerstin, E-mail: roberta@umn.edu [Astronomical Institute, Ruhr-Universitaet Bochum (Germany)
2017-02-10
In this series of papers we have presented the results of a spectroscopic survey of luminous stars in the nearby spirals M31 and M33. Here, we present spectroscopy of 132 additional stars. Most have emission-line spectra, including luminous blue variables (LBVs) and candidate LBVs, Fe ii emission line stars, the B[e] supergiants, and the warm hypergiants. Many of these objects are spectroscopically similar and are often confused with each other. We examine their similarities and differences and propose the following guidelines that can be used to help distinguish these stars in future work. (1) The B[e] supergiants have emission lines of [O i] and [Fe ii] in their spectra. Most of the spectroscopically confirmed sgB[e] stars also have warm circumstellar dust in their spectral energy distributions (SEDs). (2) Confirmed LBVs do not have the [O i] emission lines in their spectra. Some LBVs have [Fe ii] emission lines, but not all. Their SEDs show free–free emission in the near-infrared but no evidence for warm dust . Their most important and defining characteristic is the S Dor-type variability. (3) The warm hypergiants spectroscopically resemble the LBVs in their dense wind state and the B[e] supergiants. However, they are very dusty. Some have [Fe ii] and [O i] emission in their spectra like the sgB[e] stars, but are distinguished by their A- and F-type absorption-line spectra. In contrast, the B[e] supergiant spectra have strong continua and few if any apparent absorption lines. Candidate LBVs should share the spectral characteristics of the confirmed LBVs with low outflow velocities and the lack of warm circumstellar dust.
19. Outflow-Induced Dynamical and Radiative Instability in Stellar Envelopes with an Application to Luminous Blue Variables and Wolf-Rayet Stars
Science.gov (United States)
Stothers, Richard B.; Hansen, James E. (Technical Monitor)
2002-01-01
Theoretical models of the remnants of massive stars in a very hot, post-red-supergiant phase display no obvious instability if standard assumptions are made. However, the brightest observed classical luminous blue variables (LBVs) may well belong to such a phase. A simple time-dependent theory of moving stellar envelopes is developed in order to treat deep hydrodynamical disturbances caused by surface mass loss and to test the moving envelopes for dynamical instability. In the case of steady-state outflow, the theory reduces to the equivalent of the Castor, Abbott, and Klein formulation for optically thick winds at distances well above the sonic point. The time-dependent version indicates that the brightest and hottest LBVs are both dynamically and radiatively unstable, as a result of the substantial lowering of the generalized Eddington luminosity limit by the mass-loss acceleration. It is suggested that dynamical instability, by triggering secular cycles of mass loss, is primarily what differentiates LBVs from the purely radiatively unstable Wolf-Rayet stars. Furthermore, when accurate main-sequence mass-loss rates are used to calculate the evolutionary tracks, the predicted surface hydrogen and nitrogen abundances of the blue remnants agree much better with observations of the brightest LBVs than before.
20. ON THE NATURE OF THE PROTOTYPE LUMINOUS BLUE VARIABLE AG CARINAE. I. FUNDAMENTAL PARAMETERS DURING VISUAL MINIMUM PHASES AND CHANGES IN THE BOLOMETRIC LUMINOSITY DURING THE S-Dor CYCLE
International Nuclear Information System (INIS)
Groh, J. H.; Damineli, A.; Hillier, D. J.; Whitelock, P. A.; Marang, F.; Rossi, C.
2009-01-01
We present a detailed spectroscopic analysis of the luminous blue variable (LBV) AG Carinae (AG Car) during the last two visual minimum phases of its S-Dor cycle (1985-1990 and 2000-2003). The analysis reveals an overabundance of He, N, and Na, and a depletion of H, C, and O, on the surface of the AG Car, indicating the presence of a CNO-processed material. Furthermore, the ratio N/O is higher on the stellar surface than in the nebula. We found that the minimum phases of AG Car are not equal to each other, since we derived a noticeable difference between the maximum effective temperature achieved during 1985-1990 (22, 800 K) and 2000-2001 (17,000 K). Significant differences between the wind parameters in these two epochs were also noticed. While the wind terminal velocity was 300 km s -1 in 1985-1990, it was as low as 105 km s -1 in 2001. The mass-loss rate, however, was lower from 1985-1990 (1.5 x 10 -5 M sun yr -1 ) than from 2000-2001 (3.7 x 10 -5 M sun yr -1 ). We found that the wind of AG Car is significantly clumped (f ≅ 0.10-0.25) and that clumps must be formed deep in the wind. We derived a bolometric luminosity of 1.5 x 10 6 L sun during both minimum phases which, contrary to the common assumption, decreases to 1.0 x 10 6 L sun as the star moves toward the maximum flux in the V band. Assuming that the decrease in the bolometric luminosity of AG Car is due to the energy used to expand the outer layers of the star, we found that the expanding layers contain roughly 0.6-2 M sun . Such an amount of mass is an order of magnitude lower than the nebular mass around AG Car, but is comparable to the nebular mass found around lower-luminosity LBVs and to that of the Little Homunculus of Eta Car. If such a large amount of mass is indeed involved in the S Dor-type variability, we speculate that such instability could be a failed Giant Eruption, with several solar masses never becoming unbound from the star.
1. WS1: one more new Galactic bona fide luminous blue variable★
Science.gov (United States)
Kniazev, A. Y.; Gvaramadze, V. V.; Berdnikov, L. N.
2015-04-01
In this Letter, we report the results of spectroscopic and photometric monitoring of the candidate luminous blue variable (LBV) WS1, which was discovered in 2011 through the detection of a mid-infrared circular shell and follow-up optical spectroscopy of its central star. Our monitoring showed that WS1 brightened in the B, V and I bands by more than 1 mag during the last three years, while its spectrum revealed dramatic changes during the same time period, indicating that the star became much cooler. The light curve of WS1 demonstrates that the brightness of this star has reached maximum in 2013 December and then starts to decline. These findings unambiguously proved the LBV nature of WS1 and added one more member to the class of Galactic bona fide LBVs, bringing their number to sixteen (an updated census of these objects is provided).
2. Low luminance/eyes closed and monochromatic stimulations reduce variability of flash visual evoked potential latency
Directory of Open Access Journals (Sweden)
Senthil Kumar Subramanian
2013-01-01
Full Text Available Context: Visual evoked potentials are useful in investigating the physiology and pathophysiology of the human visual system. Flash visual evoked potential (FVEP, though technically easier, has less clinical utility because it shows great variations in both latency and amplitude for normal subjects. Aim: To study the effect of eye closure, low luminance, and monochromatic stimulation on the variability of FVEPs. Subjects and Methods: Subjects in self-reported good health in the age group of 18-30 years were divided into three groups. All participants underwent FVEP recording with eyes open and with white light at 0.6 J luminance (standard technique. Next recording was done in group 1 with closed eyes, group 2 with 1.2 and 20 J luminance, and group 3 with red and blue lights, while keeping all the other parameters constant. Two trials were given for each eye, for each technique. The same procedure was repeated at the same clock time on the following day. Statistical Analysis: Variation in FVEP latencies between the individuals (interindividual variability and the variations within the same individual for four trials (intraindividual variability were assessed using coefficient of variance (COV. The technique with lower COV was considered the better method. Results: Recording done with closed eyes, 0.6 J luminance, and monochromatic light (blue > red showed lower interindividual and intraindividual variability in P2 and N2 as compared to standard techniques. Conclusions: Low luminance flash stimulations and monochromatic light will reduce FVEP latency variability and may be clinically useful modifications of FVEP recording technique.
3. Variable blue straggler stars in NGC 5466
International Nuclear Information System (INIS)
Harris, H.C.; Mateo, M.; Olszewski, E.W.; Nemec, J.M.
1990-01-01
Nine variable blue stragglers have been found in the globular cluster NGC 5466. The six dwarf Cepheids in this cluster coexist in the instability strip with other nonvariable stars. The three eclipsing binaries are among the hottest of the blue stragglers. The hypothesis is discussed that all blue stragglers in this cluster have undergone mass transfer in close binaries. Under this hypothesis, rotation and spin-down play important roles in controlling the evolution of blue stragglers in old clusters and in affecting some of their observational properties. 14 refs
4. Luminous and Variable Stars in M31 and M33. V. The Upper HR Diagram
Energy Technology Data Exchange (ETDEWEB)
Humphreys, Roberta M.; Davidson, Kris; Hahn, David [Minnesota Institute for Astrophysics, 116 Church St SE, University of Minnesota, Minneapolis, MN 55455 (United States); Martin, John C. [Barber Observatory, University of Illinois, Springfield, IL 62703 (United States); Weis, Kerstin, E-mail: roberta@umn.edu [Astronomical Institute, Ruhr-Universitaet Bochum (Germany)
2017-07-20
We present HR diagrams for the massive star populations in M31 and M33, including several different types of emission-line stars: the confirmed luminous blue variables (LBVs), candidate LBVs, B[e] supergiants, and the warm hypergiants. We estimate their apparent temperatures and luminosities for comparison with their respective massive star populations and evaluate the possible relationships of these different classes of evolved, massive stars, and their evolutionary state. Several of the LBV candidates lie near the LBV/S Dor instability strip that supports their classification. Most of the B[e] supergiants, however, are less luminous than the LBVs. Many are very dusty with the infrared flux contributing one-third or more to their total flux. They are also relatively isolated from other luminous OB stars. Overall, their spatial distribution suggests a more evolved state. Some may be post-RSGs (red supergiants) like the warm hypergiants, and there may be more than one path to becoming a B[e] star. There are sufficient differences in the spectra, luminosities, spatial distribution, and the presence or lack of dust between the LBVs and B[e] supergiants to conclude that one group does not evolve into the other.
5. Psychophysical Measurements of Luminance Contrast Sensitivity and Color Discrimination with Transparent and Blue-Light Filter Intraocular Lenses.
Science.gov (United States)
da Costa, Marcelo Fernandes; Júnior, Augusto Paranhos; Lottenberg, Claudio Luiz; Castro, Leonardo Cunha; Ventura, Dora Fix
2017-12-01
The purpose of this study was to measure luminance contrast sensitivity and color vision thresholdfs in normal subjects using a blue light filter lens and transparent intraocular lens material. Monocular luminance grating contrast sensitivity was measured with Psycho for Windows (version 2.36; Cambridge Research Systems) at 3.0, 6.0, 12.0, 20.0, and 30.0 cycles per degree of visual angle (cpd) in 15 normal subjects (eight female), with a mean age of 21.6 years (SD = 3.8 years). Chromatic discrimination was assessed with the Cambridge colour test (CCT) along the protan, deutan, and tritan color confusion axes. Both tests were performed in a darkened room under two situations: with a transparent lens and with blue light filter lens. Subjective impressions were taken by subjects regarding their visual experience under both conditions. No difference was found between the luminance contrast sensitivity measured with transparent and blue light filter. However, 13/15 (87%) of the subjects reported more comfortable vision with the blue filter. In the color vision test, tritan thresholds were significantly higher for the blue filter compared with the transparent filter (p = 0.003). For protan and deutan thresholds no differences were found. Blue-yellow color vision is impaired with the blue light filter, and no impairment occurs with the transparent filter. No significant differences in thresholds were found in the luminance contrast sensitivity comparing the blue light and transparent filters. The impact of short wavelength light filtering on intrinsically photosensitive retinal ganglion cells is also discussed.
6. What drives the evolution of Luminous Compact Blue Galaxies in Clusters vs. the Field?
Science.gov (United States)
Wirth, Gregory D.; Bershady, Matthew A.; Crawford, Steven M.; Hunt, Lucas; Pisano, Daniel J.; Randriamampandry, Solohery M.
2018-06-01
Low-mass dwarf ellipticals are the most numerous members of present-day galaxy clusters, but the progenitors of this dominant population remain unclear. A prime candidate is the class of objects known as Luminous Compact Blue Galaxies (LCBGs), common in intermediate-redshift clusters but virtually extinct today. Recent cosmological simulations suggest that present-day dwarf galaxies begin as irregular field galaxies, undergo an environmentally-driven starburst phase as they enter the cluster, and stop forming stars earlier than their counterparts in the field. This model predicts that cluster dwarfs should have lower stellar mass per unit dynamical mass than their counterparts in the field. We are undertaking a two-pronged archival research program to test this key prediction using the combination of precision photometry from space and high-quality spectroscopy. First, we are combining optical HST/ACS imaging of five z=0.55 clusters (including two HST Frontier Fields) with Spitzer IR imaging and publicly-released Keck/DEIMOS spectroscopy to measure stellar-to-dynamical-mass ratios for a large sample of cluster LCBGs. Second, we are exploiting a new catalog of LCBGs in the COSMOS field to gather corresponding data for a significant sample of field LCBGs. By comparing mass ratios from these datasets, we aim to test theoretical predictions and determine the primary physical driver of cluster dwarf-galaxy evolution.
7. Protective effect of blue-light shield eyewear for adults against light pollution from self-luminous devices used at night.
Science.gov (United States)
Ayaki, Masahiko; Hattori, Atsuhiko; Maruyama, Yusuke; Nakano, Masaki; Yoshimura, Michitaka; Kitazawa, Momoko; Negishi, Kazuno; Tsubota, Kazuo
2016-01-01
We investigated sleep quality and melatonin in 12 adults who wore blue-light shield or control eyewear 2 hours before sleep while using a self-luminous portable device, and assessed visual quality for the two eyewear types. Overnight melatonin secretion was significantly higher after using the blue-light shield (P light shield (P light shield as providing acceptable visual quality.
8. P1-12: Different Double-Pulse Distinguishability Among the Luminance Opponency, the Red-Green Opponency, and the Blue-Yellow Opponency
Directory of Open Access Journals (Sweden)
Lin Shi
2012-10-01
Full Text Available The inter-stimuli-interval (ISI thresholds of double pulses discrimination were measured to investigate the temporal distinguishability of double pulses of the luminance opponency, the red-green opponency, and the blue-yellow opponency. Double pulses were presented randomly in one of four quadrants, defined by a central fixation cross on a CRT display controlled by the real time sequencer (RTS of the VSG system in 42-bit color mode calibrated with less than 3% display error rate of the 1931 CIE luminance and chromatic coordinate. Each pulse was of duration 6.7 msec and included a Gaussian patch with gradation of tristimulus values from the peak to the background in equal-energy-white (the luminance opponency or isoluminance (the red-green and the blue-yellow opponency configuration. Eleven observers were asked to report the number of pulses (one or two observed while ISI was adjusted by a psi method. Psychometric functions were estimated using the cumulative distribution function of the extreme value distribution. The threshold was the ISI value corresponding with the rate of 63.21% correct answer. Significant differences were found among ISI thresholds of the luminance, blue-yellow, and red-green opponency. Results supported that the temporal distinguishability of double pulses of the luminance opponency, the red-green opponency, and the blue-yellow opponency were significantly different. The difference can be explained by the impulse response functions (IRF with various first peak time among the luminance opponency, the red-green opponency, and the blue-yellow opponency.
9. THE WHIQII SURVEY: METALLICITIES AND SPECTROSCOPIC PROPERTIES OF LUMINOUS COMPACT BLUE GALAXIES
International Nuclear Information System (INIS)
Tollerud, Erik J.; Barton, Elizabeth J.; Cooke, Jeff; Van Zee, Liese
2010-01-01
As part of the WIYN High Image Quality Indiana-Irvine (WHIQII) survey, we present 123 spectra of faint emission-line galaxies, selected to focus on intermediate redshift (0.4 ∼ 23 -O 32 plane that differs from luminous local galaxies and is more consistent with dwarf irregulars at the present epoch, suggesting that cosmic 'downsizing' is observable in even the most fundamental parameters that describe star formation. These properties for our sample are also generally consistent with lying between local galaxies and those at high redshift, as expected by this scenario. Surprisingly, our sample exhibits no detectable correlation between compactness and metallicity, strongly suggesting that at these epochs of rapid star formation, the morphology of compact star-forming galaxies is largely transient.
10. Blue jets and gigantic jets: transient luminous events between thunderstorm tops and the lower ionosphere
International Nuclear Information System (INIS)
2008-01-01
An overview of general phenomenology and proposed physical mechanisms of large scale electrical discharges termed 'blue jets' and 'gigantic jets' observed at high altitude in the Earth's atmosphere above thunderstorms is presented. The primary emphasis is placed on summarizing available experimental data on the observed morphological features of upward jet discharges and on the discussion of recently advanced theories describing electrodynamic conditions, which facilitate escape of conventional lightning leaders from thundercloud tops and their upward propagation toward the ionosphere. It is argued that the filamentary plasma structures observed in blue jet and gigantic jet discharges are directly linked to the processes in streamer zones of lightning leaders, scaled by a significant reduction of air pressure at high altitudes.
11. Spectroscopy of Luminous Compact Blue Galaxies in Distant Clusters. I. Spectroscopic Data
Science.gov (United States)
Crawford, Steven M.; Wirth, Gregory D.; Bershady, Matthew A.; Hon, Kimo
2011-11-01
We used the DEIMOS spectrograph on the Keck II Telescope to obtain spectra of galaxies in the fields of five distant, rich galaxy clusters over the redshift range 0.5 reported in the literature, except for 11 targets which we believe were previously in error. Within our sample, we confirm the presence of 53 LCBGs in the five galaxy clusters. The clusters all stand out as distinct peaks in the redshift distribution of LCBGs with the average number density of LCBGs ranging from 1.65 ± 0.25 Mpc-3 at z = 0.55 to 3.13 ± 0.65 Mpc-3 at z = 0.8. The number density of LCBGs in clusters exceeds the field density by a factor of 749 ± 116 at z = 0.55; at z = 0.8, the corresponding ratio is E = 416 ± 95. At z = 0.55, this enhancement is well above that seen for blue galaxies or the overall cluster population, indicating that LCBGs are preferentially triggered in high-density environments at intermediate redshifts. Based in part on data obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and NASA, and was made possible by the generous financial support of the W. M. Keck Foundation.
12. THE RED NOVA-LIKE VARIABLE IN M31-A BLUE CANDIDATE IN QUIESCENCE
International Nuclear Information System (INIS)
Shara, Michael M.; Zurek, David; Prialnik, Dina; Yaron, Ofer; Kovetz, Attay
2010-01-01
M31-RV was an extraordinarily luminous (∼10 6 L sun ) eruptive variable, displaying very cool temperatures (roughly 1000 K) as it faded. While this object's peak luminosity matched or exceeded those of the brightest known classical novae, its red colors and cool spectra were very different from those of classical novae. The photometric behavior of M31-RV (and several other very red novae, i.e., luminous eruptive red variables) has led to several models of this apparently new class of astrophysical object. We list these models, which predict very red eruptions and very red remnants decades after the eruptions. One of the most detailed models is that of 'mergebursts'. Mergebursts are (hypothetical) mergers of close binary stars, predicted to rival or exceed the brightest classical novae in luminosity, but to be much cooler and redder than classical novae, and to become slowly hotter and bluer as they age. This prediction suggests two stringent and definitive tests of the mergeburst hypothesis. First, there should always be a cool red remnant, and NOT a hot blue remnant at the site of such an outburst. Second, the inflated envelope of a mergeburst event should be slowly contracting; hence, it must display a slowly rising effective temperature. We have searched the location of M31-RV in multiple observatory archives. Our search revealed a luminous, UV-bright object within 0.''4 (1.5σ of the astrometric position) of M31-RV in archival WFPC2 images taken 10 years after the outburst. Recent Hubble imagery, 20 years after the outburst, determines that this object is still hot and fading; it remains much too hot to be a mergeburst. Furthermore, the effective temperature of this object is declining, contrary to the prediction for mergebursts. If we have correctly identified M31-RV's remnant, it cannot be a mergeburst-but its behavior is consistent with theoretical nova models which erupt on a low-mass white dwarf. Future Hubble UV and visible images could determine if the
13. Temporal variability of green and blue water footprint worldwide
Science.gov (United States)
Tamea, Stefania; Lomurno, Marianna; Tuninetti, Marta; Laio, Francesco; Ridolfi, Luca
2016-04-01
Water footprint assessment is becoming widely used in the scientific literature and it is proving useful in a number of multidisciplinary contexts. Given this increasing popularity, measures of green and blue water footprint (or virtual water content, VWC) require evaluations of uncertainty and variability to quantify the reliability of proposed analyses. As of today, no studies are known to assess the temporal variability of crop VWC at the global scale; the present contribution aims at filling this gap. We use a global high-resolution distributed model to compute the VWC of staple crops (wheat and maize), basing on the soil water balance, forced by hydroclimatic imputs, and on the total crop evapotranspiration in multiple growing seasons. Crop actual yield is estimated using country-based yield data, adjusted to account for spatial variability, allowing for the analysis of the different role played by climatic and management factors in the definition of crop yield. The model is then run using hydroclimatic data, i.e., precipitation and potential evapotranspiration, for the period 1961-2013 as taken from the CRU database (CRU TS v. 3.23) and using the corresponding country-based yield data from FAOSTAT. Results provide the time series of total evapotranspiration, actual yield and VWC, with separation between green and blue VWC, and the overall volume of water used for crop production, both at the cell scale (5x5 arc-min) and aggregated at the country scale. Preliminary results indicate that total (green+blue) VWC is, in general, weekly dependent on hydroclimatic forcings if water for irrigation is unlimited, because irrigated agriculture allows to compensate temporary water shortage. Conversely, most part of the VWC variability is found to be determined by the temporal evolution of crop yield. At the country scale, the total water used by countries for agricultural production has seen a limited change in time, but the marked increase in the water-use efficiency
14. VizieR Online Data Catalog: 2 new candidate luminous blue variables (Gvaramadze+ 2012)
Science.gov (United States)
Gvaramadze, V. V.; Kniazev, A. Y.; Miroshnichenko, A. S.; Berdnikov, L. N.; Langer, N.; Stringfellow, G. S.; Todt, H.; Hamann, W.-R.; Grebel, E. K.; Buckley, D.; Crause, L.; Crawford, S.; Gulbis, A.; Hettlage, C.; Hooper, E.; Husser, T.-O.; Kotze, P.; Loaring, N.; Nordsieck, K. H.; O'Donoghue, D.; Pickering, T.; Potter, S.; Romero Colmenero, E.; Vaisanen, P.; Williams, T.; Wolf, M.; Reichart, D. E.; Ivarsen, K. M.; Haislip, J. B.; Nysewander, M. C.; Lacluyze, A. P.
2013-03-01
Two circular shells, which are the main subject of this paper, were discovered using the WISE 22-um archival data. Spectral observations of WS1 and WS2 were conducted with SALT on 2011 June 12 and 13 during the performance verification phase of the Robert Stobie Spectrograph. (3 data files).
15. A 'variable' stellar object in a variable blue nebula V-V 1-7
International Nuclear Information System (INIS)
Rao, N.K.; Gilra, D.P.
1981-01-01
V-V 1-7 is supposed to be one of the few planetary nebulae with Ao central stars and was included in the planetary-nebula catalogue as PK 235 + 1 0 1. The nebula was seen on the blue Palomar Observatory Sky Survey (POSS) print but not on the red print; as a result it was thought that it might be a reflection nebula. However, the symmetry of the nebula around the central star (HD 62001), and also the ultraviolet photometric variability of this central star led others to suggest that the nebula might be a nova shell. Subsequently it was found that the nebula V-V 1-7 has disappeared. It is not seen on any direct plate known to us except the POSS blue plate. In this paper the disappearance is reported (along with the nebula) of a stellar object, which appears within the 'nebular shell' of V-V 1-7 on the POSS blue plate, but not on the red plate. (author)
16. The effects of luminance contrast, colour combinations, font, and search time on brand icon legibility.
Science.gov (United States)
Ko, Ya-Hsien
2017-11-01
This study explored and identified the effects of luminance contrast, colour combinations, font, and search time on brand icon legibility. A total of 108 participants took part in the experiment. As designed, legibility was measured as a function of the following independent variables: four levels of luminance contrast, sixteen target/background colour combinations, two fonts, and three search times. The results showed that a luminance contrast of 18:1 provided readers with the best legibility. Yellow on black, yellow on blue, and white on blue were the three most legible colour combinations. One of this study's unique findings was that colour combinations may play an even more important role than luminance contrast in the overall legibility of brand icon design. The 12-s search time corresponded with the highest legibility. Arial font was more legible than Times New Roman. These results provide some guidance for brand icon and product advertisement design. Copyright © 2017 Elsevier Ltd. All rights reserved.
17. The VIMOS Public Extragalactic Redshift Survey (VIPERS). An unbiased estimate of the growth rate of structure at ⟨z⟩ = 0.85 using the clustering of luminous blue galaxies
Science.gov (United States)
Mohammad, F. G.; Granett, B. R.; Guzzo, L.; Bel, J.; Branchini, E.; de la Torre, S.; Moscardini, L.; Peacock, J. A.; Bolzonella, M.; Garilli, B.; Scodeggio, M.; Abbas, U.; Adami, C.; Bottini, D.; Cappi, A.; Cucciati, O.; Davidzon, I.; Franzetti, P.; Fritz, A.; Iovino, A.; Krywult, J.; Le Brun, V.; Le Fèvre, O.; Maccagni, D.; Małek, K.; Marulli, F.; Polletta, M.; Pollo, A.; Tasca, L. A. M.; Tojeiro, R.; Vergani, D.; Zanichelli, A.; Arnouts, S.; Coupon, J.; De Lucia, G.; Ilbert, O.; Moutard, T.
2018-02-01
We used the VIMOS Public Extragalactic Redshift Survey (VIPERS) final data release (PDR-2) to investigate the performance of colour-selected populations of galaxies as tracers of linear large-scale motions. We empirically selected volume-limited samples of blue and red galaxies as to minimise the systematic error on the estimate of the growth rate of structure fσ8 from the anisotropy of the two-point correlation function. To this end, rather than rigidly splitting the sample into two colour classes we defined the red or blue fractional contribution of each object through a weight based on the (U - V ) colour distribution. Using mock surveys that are designed to reproduce the observed properties of VIPERS galaxies, we find the systematic error in recovering the fiducial value of fσ8 to be minimised when using a volume-limited sample of luminous blue galaxies. We modelled non-linear corrections via the Scoccimarro extension of the Kaiser model (with updated fitting formulae for the velocity power spectra), finding systematic errors on fσ8 of below 1-2%, using scales as small as 5 h-1 Mpc. We interpret this result as indicating that selection of luminous blue galaxies maximises the fraction that are central objects in their dark matter haloes; this in turn minimises the contribution to the measured ξ(rp,π) from the 1-halo term, which is dominated by non-linear motions. The gain is inferior if one uses the full magnitude-limited sample of blue objects, consistent with the presence of a significant fraction of blue, fainter satellites dominated by non-streaming, orbital velocities. We measured a value of fσ8 = 0.45 ± 0.11 over the single redshift range 0.6 ≤ z ≤ 1.0, corresponding to an effective redshift for the blue galaxies ⟨z⟩=0.85. Including in the likelihood the potential extra information contained in the blue-red galaxy cross-correlation function does not lead to an appreciable improvement in the error bars, while it increases the systematic error
18. Inter-Annual Variability in Blue Whale Distribution off Southern Sri Lanka between 2011 and 2012
Directory of Open Access Journals (Sweden)
Asha de Vos
2014-07-01
Full Text Available Blue whale (Balaenoptera musculus movements are often driven by the availability of their prey in space and time. While globally blue whale populations undertake long-range migrations between feeding and breeding grounds, those in the northern Indian Ocean remain in low latitude waters throughout the year with the implication that the productivity of these waters is sufficient to support their energy needs. A part of this population remains around Sri Lanka where they are usually recorded close to the southern coast during the Northeast Monsoon. To investigate inter-annual variability in sighting locations, we conducted systematic Conductivity-Temperature-Depth (CTD and visual surveys between January–March 2011 and January–March 2012. In 2011, there was a notable decrease in inshore sightings compared to 2009 and 2012 (p < 0.001. CTD data revealed that in 2011 there was increased freshwater in the upper water column accompanied by deeper upwelling than in 2012. We hypothesise that anomalous rainfall, along with higher turbidity resulting from river discharge, affected the productivity of the inshore waters and caused a shift in blue whale prey and, consequently, the distribution of the whales themselves. An understanding of how predators and their prey respond to environmental variability is important for predicting how these species will respond to long-term changes. This is especially important given the rapid temperature increases predicted for the semi-enclosed northern Indian Ocean.
19. Prolonged Sitting is Associated with Attenuated Heart Rate Variability during Sleep in Blue-Collar Workers
Directory of Open Access Journals (Sweden)
David M Hallman
2015-11-01
Full Text Available Prolonged sitting is associated with increased risk for cardiovascular diseases and mortality. However, research into the physiological determinants underlying this relationship is still in its infancy. The aim of the study was to determine the extent to which occupational and leisure-time sitting are associated with nocturnal heart rate variability (HRV in blue-collar workers. The study included 138 blue-collar workers (mean age 45.5 (SD 9.4 years. Sitting-time was measured objectively for four days using tri-axial accelerometers (Actigraph GT3X+ worn on the thigh and trunk. During the same period, a heart rate monitor (Actiheart was used to sample R-R intervals from the electrocardiogram. Time and frequency domain indices of HRV were only derived during nighttime sleep, and used as markers of cardiac autonomic modulation. Regression analyses with multiple adjustments (age, gender, body mass index, smoking, job-seniority, physical work-load, influence at work, and moderate-to-vigorous physical activity were used to investigate the association between sitting time and nocturnal HRV. We found that occupational sitting-time was negatively associated (p < 0.05 with time and frequency domain HRV indices. Sitting-time explained up to 6% of the variance in HRV, independent of the covariates. Leisure-time sitting was not significantly associated with any HRV indices (p > 0.05. In conclusion, objectively measured occupational sitting-time was associated with reduced nocturnal HRV in blue-collar workers. This indicates an attenuated cardiac autonomic regulation with increasing sitting-time at work regardless of moderate-to-vigorous physical activity. The implications of this association for cardiovascular disease risk warrant further investigation via long-term prospective studies and intervention studies.
20. Very Rapid High-amplitude Gamma-Ray Variability in Luminous Blazar PKS 1510-089 Studied with Fermi-LAT
Energy Technology Data Exchange (ETDEWEB)
Saito, S.; Stawarz, L.; Tanaka, Y.T.; Takahashi, T.; Madejski, G.; D' Ammando, F.
2013-03-20
Here we report on the detailed analysis of the γ-ray light curve of a luminous blazar PKS 1510-089 observed in the GeV range with the Large Area Telescope (LAT) onboard the Fermi satellite during the period 2011 September - December. By investigating the properties of the detected three major flares with the shortest possible time binning allowed by the photon statistics, we find a variety of temporal characteristics and variability patterns. This includes a clearly asymmetric profile (with a faster flux rise and a slower decay) of the flare resolved on sub-daily timescales, a superposition of many short uncorrelated flaring events forming the apparently coherent longer-duration outburst, and a huge single isolated outburst unresolved down to the timescale of three-hours. In the latter case we estimate the corresponding γ-ray flux doubling timescale to be below one hour, which is extreme and never previously reported for any active galaxy
1. Climate Change Impact on Variability of Rainfall Intensity in Upper Blue Nile Basin, Ethiopia
Science.gov (United States)
Worku, L. Y.
2015-12-01
Extreme rainfall events are major problems in Ethiopia with the resulting floods that usually could cause significant damage to agriculture, ecology, infrastructure, disruption to human activities, loss of property, loss of lives and disease outbreak. The aim of this study was to explore the likely changes of precipitation extreme changes due to future climate change. The study specifically focuses to understand the future climate change impact on variability of rainfall intensity-duration-frequency in Upper Blue Nile basin. Precipitations data from two Global Climate Models (GCMs) have been used in the study are HadCM3 and CGCM3. Rainfall frequency analysis was carried out to estimate quantile with different return periods. Probability Weighted Method (PWM) selected estimation of parameter distribution and L-Moment Ratio Diagrams (LMRDs) used to find the best parent distribution for each station. Therefore, parent distributions for derived from frequency analysis are Generalized Logistic (GLOG), Generalized Extreme Value (GEV), and Gamma & Pearson III (P3) parent distribution. After analyzing estimated quantile simple disaggregation model was applied in order to find sub daily rainfall data. Finally the disaggregated rainfall is fitted to find IDF curve and the result shows in most parts of the basin rainfall intensity expected to increase in the future. As a result of the two GCM outputs, the study indicates there will be likely increase of precipitation extremes over the Blue Nile basin due to the changing climate. This study should be interpreted with caution as the GCM model outputs in this part of the world have huge uncertainty.
2. An extremely luminous and variable ultraluminous X-ray source in the outskirts of Circinus observed with NuSTAR
Energy Technology Data Exchange (ETDEWEB)
Walton, D. J.; Fuerst, F.; Harrison, F.; Stern, D.; Grefenstette, B. W.; Madsen, K. K.; Rana, V. [Space Radiation Laboratory, California Institute of Technology, Pasadena, CA 91125 (United States); Bachetti, M.; Barret, D.; Webb, N. A. [Universite de Toulouse, UPS-OMP, IRAP, Toulouse (France); Bauer, F. [Instituto de Astrofísica, Facultad de Física, Pontificia Universidad Católica de Chile, 306, Santiago 22 (Chile); Boggs, S. E.; Craig, W. W. [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Christensen, F. E. [DTU Space, National Space Institute, Technical University of Denmark, Elektrovej 327, DK-2800 Lyngby (Denmark); Fabian, A. C. [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom); Hailey, C. J. [Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Miller, J. M. [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109-1042 (United States); Ptak, A.; Zhang, W. W. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)
2013-12-20
Following a serendipitous detection with the Nuclear Spectroscopic Telescope Array (NuSTAR), we present a multi-epoch spectral and temporal analysis of an extreme ultraluminous X-ray source (ULX) located in the outskirts of the Circinus galaxy, hereafter Circinus ULX5, including coordinated XMM-Newton+NuSTAR follow-up observations. The NuSTAR data presented here represent one of the first instances of a ULX reliably detected at hard (E > 10 keV) X-rays. Circinus ULX5 is variable on long time scales by at least a factor of ∼5 in flux, and was caught in a historically bright state during our 2013 observations (0.3-30.0 keV luminosity of 1.6 × 10{sup 40} erg s{sup –1}). During this epoch, the source displayed a curved 3-10 keV spectrum, broadly similar to other bright ULXs. Although pure thermal models result in a high energy excess in the NuSTAR data, this excess is too weak to be modeled with the disk reflection interpretation previously proposed to explain the 3-10 keV curvature in other ULXs. In addition to flux variability, clear spectral variability is also observed. While in many cases the interpretation of spectral components in ULXs is uncertain, the spectral and temporal properties of all the high quality data sets currently available strongly support a simple disk-corona model reminiscent of that invoked for Galactic binaries, with the accretion disk becoming more prominent as the luminosity increases. However, although the disk temperature and luminosity are well correlated across all time scales currently probed, the observed luminosity follows L∝T {sup 1.70±0.17}, flatter than expected for simple blackbody radiation. The spectral variability displayed here is highly reminiscent of that observed from known Galactic black hole binaries (BHBs) at high luminosities. This comparison implies a black hole mass of ∼90 M {sub ☉} for Circinus ULX5. However, given the diverse behavior observed from Galactic BHB accretion disks, this mass estimate is
3. Assessment of AOD variability over Saudi Arabia using MODIS Deep Blue products
International Nuclear Information System (INIS)
Butt, Mohsin Jamil; Assiri, Mazen Ebraheem; Ali, Md. Arfan
2017-01-01
The aim of this study is to investigate the variability of aerosol over The Kingdom of Saudi Arabia. For this analysis, Moderate Resolution Imaging Spectroradiometer (MODIS) Deep Blue (DB) Aerosol Optical Depth (AOD) product from Terra and Aqua satellites for the years 2000–2013 is used. The product is validated using AERONET data from ground stations, which are situated at Solar Village Riyadh and King Abdullah University of Science and Technology (KAUST) Jeddah. The results show that both Terra and Aqua satellites exhibit a tendency to show the spatial variation of AOD with Aqua being better than Terra to represent the ground based AOD measurements over the study region. The results also show that the eastern, central, and southern regions of the country have a high concentration of AOD during the study period. The validation results show the highest correlation coefficient between Aqua and KAUST data with a value of 0.79, whilst the Aqua and Solar Village based AOD indicates the lowest Root Mean Square Error (RMSE) and Mean Absolute Error (MAE) values which are, 0.17 and 0.12 respectively. Furthermore, the Relative Mean Bias (RMB) based analysis show that the DB algorithm overestimates the AOD when using Terra and Solar Village data, while it underestimates the AOD when using Aqua with Solar Village and KAUST data. The RMB value for Aqua and Solar Village data indicates that the DB algorithm is close to normal in the study region. - Highlights: • The significance of aerosol in the Kingdom of Saudi Arabia is addressed. • MODIS (Terra and Aqua), AERONET and ground based sand event data is used. • MODIS DB product is used to prepare annual aerosol maps and monthly AOD variability. • A comparison is made between Terra and Aqua AOD product over bright surface. • MODIS DB AOD product is validated using AERONET data at Solar Village and KAUST. - This research highlighted the aerosol variability over The Kingdom of Saudi Arabia by using Satellite, AERONET
4. Application of Artificial Neural Networks (ANNs for Weight Predictions of Blue Crabs (Callinectes sapidus RATHBUN, 1896 Using Predictor Variables
Directory of Open Access Journals (Sweden)
C. TURELI BILEN
2011-10-01
Full Text Available An evaluation of the performance of artificial networks (ANNs to estimate the weights of blue crab (Callinectes sapidus catches in Yumurtalık Cove (Iskenderun Bay that uses measured predictor variables is presented, including carapace width (CW, sex (male, female and female with eggs, and sampling month. Blue crabs (n=410 were collected each month between 15 September 1996 and 15 May 1998. Sex, CW, and sampling month were used and specified in the input layer of the network. The weights of the blue crabs were utilized in the output layer of the network. A multi-layer perception architecture model was used and was calibrated with the Levenberg Marguardt (LM algorithm. Finally, the values were determined by the ANN model using the actual data. The mean square error (MSE was measured as 3.3, and the best results had a correlation coefficient (R of 0.93. We compared the predictive capacity of the general linear model (GLM versus the Artificial Neural Network model (ANN for the estimation of the weights of blue crabs from independent field data. The results indicated the higher performance capacity of the ANN to predict weights compared to the GLM (R=0.97 vs. R=0.95, raw variable when evaluated against independent field data.
5. Inter-Annual Variability in Blue Whale Distribution off Southern Sri Lanka between 2011 and 2012
OpenAIRE
Vos, Asha de; Pattiaratchi, Charitha; Harcourt, Robert
2014-01-01
Blue whale (Balaenoptera musculus) movements are often driven by the availability of their prey in space and time. While globally blue whale populations undertake long-range migrations between feeding and breeding grounds, those in the northern Indian Ocean remain in low latitude waters throughout the year with the implication that the productivity of these waters is sufficient to support their energy needs. A part of this population remains around Sri Lanka where they are usually recorded cl...
6. The luminous and the grey
CERN Document Server
Batchelor, David
2014-01-01
Color surrounds us: the lush green hues of trees and grasses, the variant blues of water and the sky, the bright pops of yellow and red from flowers. But at the same time, color lies at the limits of language and understanding. In this absorbing sequel to Chromophobia-which addresses the extremes of love and loathing provoked by color since antiquity-David Batchelor charts color's more ambiguous terrain. The Luminous and the Grey explores the places where color comes into being and where it fades away, probing when it begins and when it ends both in the imagination and in the material world.
7. SN2015bh: NGC2770's 4th supernova or a luminous blue variable on its way to a Wolf-Rayet star?
DEFF Research Database (Denmark)
Thone, C. C.; de Ugarte Postigo, A.; Leloudas, G.
2017-01-01
yr that experienced a possible terminal explosion as type IIn SN in 2015, named SN 2015bh. This possible SN (or " main event") had a precursor peaking similar to 40 days before maximum. The total energy release of the main event ;is similar to 1.8 X 10(49) erg, consistent with a ... 2015bh lies within a spiral arm of NGC2770 next to several small star-forming regions with a metallicity of similar to 0.5 solar and a stellar population age of 7-10 Myr. SN 2015bh shares many similarities with SN 2009ip and may form a new class of objects that exhibit outbursts a few decades prior...
8. Variability in the carbon storage of seagrass habitats and its implications for global estimates of blue carbon ecosystem service.
Directory of Open Access Journals (Sweden)
Paul S Lavery
Full Text Available The recent focus on carbon trading has intensified interest in 'Blue Carbon'-carbon sequestered by coastal vegetated ecosystems, particularly seagrasses. Most information on seagrass carbon storage is derived from studies of a single species, Posidonia oceanica, from the Mediterranean Sea. We surveyed 17 Australian seagrass habitats to assess the variability in their sedimentary organic carbon (C org stocks. The habitats encompassed 10 species, in mono-specific or mixed meadows, depositional to exposed habitats and temperate to tropical habitats. There was an 18-fold difference in the Corg stock (1.09-20.14 mg C org cm(-3 for a temperate Posidonia sinuosa and a temperate, estuarine P. australis meadow, respectively. Integrated over the top 25 cm of sediment, this equated to an areal stock of 262-4833 g C org m(-2. For some species, there was an effect of water depth on the C org stocks, with greater stocks in deeper sites; no differences were found among sub-tidal and inter-tidal habitats. The estimated carbon storage in Australian seagrass ecosystems, taking into account inter-habitat variability, was 155 Mt. At a 2014-15 fixed carbon price of A$25.40 t(-1 and an estimated market price of$35 t(-1 in 2020, the C org stock in the top 25 cm of seagrass habitats has a potential value of $AUD 3.9-5.4 bill. The estimates of annual C org accumulation by Australian seagrasses ranged from 0.093 to 6.15 Mt, with a most probable estimate of 0.93 Mt y(-1 (10.1 t. km(-2 y(-1. These estimates, while large, were one-third of those that would be calculated if inter-habitat variability in carbon stocks were not taken into account. We conclude that there is an urgent need for more information on the variability in seagrass carbon stock and accumulation rates, and the factors driving this variability, in order to improve global estimates of seagrass Blue Carbon storage. 9. White LEDs with limit luminous efficacy Energy Technology Data Exchange (ETDEWEB) Lisitsyn, V. M.; Stepanov, S. A., E-mail: stepanovsa@tpu.ru; Yangyang, Ju [National Research Tomsk Polytechnic University, 30 Lenin Av., Tomsk, 634050 (Russian Federation); Lukash, V. S. [JSC Research Institute of Semiconductor Devices, 99a Krasnoarmeyskaja St., Tomsk, 634050 (Russian Federation) 2016-01-15 In most promising widespread gallium nitride based LEDs emission is generated in the blue spectral region with a maximum at about 450 nm which is converted to visible light with the desired spectrum by means of phosphor. The thermal energy in the conversion is determined by the difference in the energies of excitation and emission quanta and the phosphor quantum yield. Heat losses manifest themselves as decrease in the luminous efficacy. LED heating significantly reduces its efficiency and life. In addition, while heating, the emission generation output and the efficiency of the emission conversion decrease. Therefore, the reduction of the energy losses caused by heating is crucial for LED development. In this paper, heat losses in phosphor-converted LEDs (hereinafter chips) during spectrum conversion are estimated. The limit values of the luminous efficacy for white LEDs are evaluated. 10. Optical system for a universal luminance meter NARCIS (Netherlands) Schreuder, D.A. 1965-01-01 There is a need for luminance meters in various fields of photometry having these characteristics: a- objective method of measurements. b. variable shape and size of measurement area. c- absence of parallax during aiming operations. d- Possibility of observing the part of the field of view to be 11. Analyzing the variability of sediment yield: A case study from paired watersheds in the Upper Blue Nile basin, Ethiopia Science.gov (United States) Ebabu, Kindiye; Tsunekawa, Atsushi; Haregeweyn, Nigussie; Adgo, Enyew; Meshesha, Derege Tsegaye; Aklog, Dagnachew; Masunaga, Tsugiyuki; Tsubo, Mitsuru; Sultan, Dagnenet; Fenta, Ayele Almaw; Yibeltal, Mesenbet 2018-02-01 Improved knowledge of watershed-scale spatial and temporal variability of sediment yields (SY) is needed to design erosion control strategies, particularly in the most severely eroded areas. The present study was conducted to provide this knowledge for the humid tropical highlands of Ethiopia using the Akusity and Kasiry paired watersheds in the Guder portion of the Upper Blue Nile basin. Discharge and suspended sediment concentration data were monitored during the rainy season of 2014 and 2015 using automatic flow stage sensors, manual staff gauges and a depth-integrated sediment sampler. The SY was calculated using empirical discharge-sediment curves for different parts of each rainy season. The measured mean daily sediment concentration differed greatly between years and watersheds (0.51 g L- 1 in 2014 and 0.92 g L- 1 in 2015 for Kasiry, and 1.04 g L- 1 in 2014 and 2.20 g L- 1 in 2015 for Akusity). Sediment concentrations at both sites decreased as the rainy season progressed, regardless of the rainfall pattern, owing to depletion of the sediment supply and limited transport capacity of the flows caused by increased vegetation cover. Rainy season SYs for Kasiry were 7.6 t ha- 1 in 2014 and 27.2 t ha- 1 in 2015, while in Akusity SYs were 25.7 t ha- 1 in 2014 and 71.2 t ha- 1 in 2015. The much larger values in 2015 can be partly explained by increased rainfall and larger peak flow events. The magnitude and timing of peak flow events are major determinants of the amount and variability of SYs. Thus, site-specific assessment of such events is crucial to reveal SY dynamics of small watersheds in tropical highland environments. 12. The effect of chromatic and luminance information on reaction times. Science.gov (United States) O'Donell, Beatriz M; Barraza, Jose F; Colombo, Elisa M 2010-07-01 We present a series of experiments exploring the effect of chromaticity on reaction time (RT) for a variety of stimulus conditions, including chromatic and luminance contrast, luminance, and size. The chromaticity of these stimuli was varied along a series of vectors in color space that included the two chromatic-opponent-cone axes, a red-green (L-M) axis and a blue-yellow [S - (L + M)] axis, and intermediate noncardinal orientations, as well as the luminance axis (L + M). For Weber luminance contrasts above 10-20%, RTs tend to the same asymptote, irrespective of chromatic direction. At lower luminance contrast, the addition of chromatic information shortens the RT. RTs are strongly influenced by stimulus size when the chromatic stimulus is modulated along the [S - (L + M)] pathway and by stimulus size and adaptation luminance for the (L-M) pathway. RTs are independent of stimulus size for stimuli larger than 0.5 deg. Data are modeled with a modified version of Pieron's formula with an exponent close to 2, in which the stimulus intensity term is replaced by a factor that considers the relative effects of chromatic and achromatic information, as indexed by the RMS (square-root of the cone contrast) value at isoluminance and the Weber luminance contrast, respectively. The parameters of the model reveal how RT is linked to stimulus size, chromatic channels, and adaptation luminance and how they can be interpreted in terms of two chromatic mechanisms. This equation predicts that, for isoluminance, RTs for a stimulus lying on the S-cone pathway are higher than those for a stimulus lying on the L-M-cone pathway, for a given RMS cone contrast. The equation also predicts an asymptotic trend to the RT for an achromatic stimulus when the luminance contrast is sufficiently large. 13. Paul Callaghan luminous moments CERN Document Server Callaghan, Paul 2013-01-01 Acknowledged internationally for his ground-breaking scientific research in the field of magnetic resonance, Sir Paul Callaghan was a scientist and visionary with a rare gift for promoting science to a wide audience. He was named New Zealander of the Year in 2011. His death in early 2012 robbed New Zealand of an inspirational leader. Paul Callaghan: Luminous Moments brings together some of his most significant writing. Whether he describes his childhood in Wanganui, reflects on discovering the beauty of science, sets out New Zealand's future potential or discusses the experience of fa 14. SPECTRAL AND SPATIAL SELECTIVITY OF LUMINANCE VISION IN REEF FISH Directory of Open Access Journals (Sweden) Ulrike E Siebeck 2014-09-01 Full Text Available Luminance vision has high spatial resolution and is used for form vision and texture discrimination. In humans, birds and bees luminance channel is spectrally selective – it depends on the signals of the long-wavelength sensitive photoreceptors (bees or on the sum of long- and middle- wavelength sensitive cones (humans, but not on the signal of the short-wavelength sensitive (blue photoreceptors. The reasons of such selectivity are not fully understood. The aim of this study is to reveal the inputs of cone signals to high resolution luminance vision in reef fish. 16 freshly caught damselfish, Pomacentrus amboinensis, were trained to discriminate stimuli differing either in their colour or in their fine patterns (stripes vs. cheques. Three colours (‘bright green’, ‘dark green’ and ‘blue’ were used to create two sets of colour and two sets of pattern stimuli. The ‘bright green’ and ‘dark green’ were similar in their chromatic properties for fish, but differed in their lightness; the ‘dark green’ differed from ‘blue’ in the signal for the blue cone, but yielded similar signals in the long-wavelength and middle-wavelength cones. Fish easily learned to discriminate ‘bright green’ from ‘dark green’ and ‘dark green’ from ‘blue’ stimuli. Fish also could discriminate the fine patterns created from ‘dark green’ and ‘bright green’. However, fish failed to discriminate fine patterns created from ‘blue’ and ‘dark green’ colours, i.e. the colours that provided contrast for the blue-sensitive photoreceptor, but not for the long-wavelength sensitive one. High resolution luminance vision in damselfish, Pomacentrus amboinensis, does not have input from the blue-sensitive cone, which may indicate that the spectral selectivity of luminance channel is a general feature of visual processing in both aquatic and terrestrial animals. 15. The role of luminance and chromatic cues in emmetropisation. Science.gov (United States) Rucker, Frances J 2013-05-01 At birth most, but not all eyes, are hyperopic. Over the course of the first few years of life the refraction gradually becomes close to zero through a process called emmetropisation. This process is not thought to require accommodation, though a lag of accommodation has been implicated in myopia development, suggesting that the accuracy of accommodation is an important factor. This review will cover research on accommodation and emmetropisation that relates to the ability of the eye to use colour and luminance cues to guide the responses. There are three ways in which changes in luminance and colour contrast could provide cues: (1) The eye could maximize luminance contrast. Monochromatic light experiments have shown that the human eye can accommodate and animal eyes can emmetropise using changes in luminance contrast alone. However, by reducing the effectiveness of luminance cues in monochromatic and white light by introducing astigmatism, or by reducing light intensity, investigators have revealed that the eye also uses colour cues in emmetropisation. (2) The eye could compare relative cone contrast to derive the sign of defocus information from colour cues. Experiments involving simulations of the retinal image with defocus have shown that relative cone contrast can provide colour cues for defocus in accommodation and emmetropisation. In the myopic simulation the contrast of the red component of a sinusoidal grating was higher than that of the green and blue component and this caused relaxation of accommodation and reduced eye growth. In the hyperopic simulation the contrast of the blue component was higher than that of the green and red components and this caused increased accommodation and increased eye growth. (3) The eye could compare the change in luminance and colour contrast as the eye changes focus. An experiment has shown that changes in colour or luminance contrast can provide cues for defocus in emmetropisation. When the eye is exposed to colour 16. Organizational justice is related to heart rate variability in white-collar workers, but not in blue-collar workers-findings from a cross-sectional study. Science.gov (United States) Herr, Raphael M; Bosch, Jos A; van Vianen, Annelies E M; Jarczok, Marc N; Thayer, Julian F; Li, Jian; Schmidt, Burkhard; Fischer, Joachim E; Loerbroks, Adrian 2015-06-01 Perceived injustice at work predicts coronary heart disease. Vagal dysregulation represents a potential psychobiological pathway. We examined associations between organizational justice and heart rate variability (HRV) indicators. Grounded in social exchange and psychological contract theory, we tested predictions that these associations are more pronounced among white-collar than among blue-collar workers. Cross-sectional data from 222 blue-collar and 179 white-collar men were used. Interactional and procedural justice were measured by questionnaire. Ambulatory HRV was assessed across 24 h. Standardized regression coefficients (β) were calculated. Among white-collar workers, interactional justice showed positive relationships with 24-h HRV, which were strongest during sleeping time (adjusted βs≥0.26; p values≤0.01). No associations were found for blue-collar workers. A comparable but attenuated pattern was observed for procedural justice. Both dimensions of organizational injustice were associated with lowered HRV among white-collar workers. The impact of justice and possibly its association with health seems to differ by occupational groups. 17. Assessment of the impact of climate change on spatiotemporal variability of blue and green water resources under CMIP3 and CMIP5 models in a highly mountainous watershed Science.gov (United States) Fazeli Farsani, Iman; Farzaneh, M. R.; Besalatpour, A. A.; Salehi, M. H.; Faramarzi, M. 2018-04-01 The variability and uncertainty of water resources associated with climate change are critical issues in arid and semi-arid regions. In this study, we used the soil and water assessment tool (SWAT) to evaluate the impact of climate change on the spatial and temporal variability of water resources in the Bazoft watershed, Iran. The analysis was based on changes of blue water flow, green water flow, and green water storage for a future period (2010-2099) compared to a historical period (1992-2008). The r-factor, p-factor, R 2, and Nash-Sutcliff coefficients for discharge were 1.02, 0.89, 0.80, and 0.80 for the calibration period and 1.03, 0.76, 0.57, and 0.59 for the validation period, respectively. General circulation models (GCMs) under 18 emission scenarios from the IPCC's Fourth (AR4) and Fifth (AR5) Assessment Reports were fed into the SWAT model. At the sub-basin level, blue water tended to decrease, while green water flow tended to increase in the future scenario, and green water storage was predicted to continue its historical trend into the future. At the monthly time scale, the 95% prediction uncertainty bands (95PPUs) of blue and green water flows varied widely in the watershed. A large number (18) of climate change scenarios fell within the estimated uncertainty band of the historical period. The large differences among scenarios indicated high levels of uncertainty in the watershed. Our results reveal that the spatial patterns of water resource components and their uncertainties in the context of climate change are notably different between IPCC AR4 and AR5 in the Bazoft watershed. This study provides a strong basis for water supply-demand analyses, and the general analytical framework can be applied to other study areas with similar challenges. 18. Luminance requirements for lighted signage Science.gov (United States) Freyssinier, Jean Paul; Narendran, Nadarajah; Bullough, John D. 2006-08-01 Light-emitting diode (LED) technology is presently targeted to displace traditional light sources in backlighted signage. The literature shows that brightness and contrast are perhaps the two most important elements of a sign that determine its attention-getting capabilities and its legibility. Presently, there are no luminance standards for signage, and the practice of developing brighter signs to compete with signs in adjacent businesses is becoming more commonplace. Sign luminances in such cases may far exceed what people usually need for identifying and reading a sign. Furthermore, the practice of higher sign luminance than needed has many negative consequences, including higher energy use and light pollution. To move toward development of a recommendation for lighted signage, several laboratory human factors evaluations were conducted. A scale model of a storefront was used to present human subjects with a typical red channel-letter sign at luminances ranging from 8 cd/m2 to 1512 cd/m2 under four background luminances typical of nighttime outdoor and daytime inside-mall conditions (1, 100, 300, 1000 cd/m2), from three scaled viewing distances (30, 60, 340 ft), and either in isolation or adjacent to two similar signs. Subjects rated the brightness, acceptability, and ease of reading of the test sign for each combination of sign and background luminances and scaled viewing distances. 19. Variability assesment of some morphological traits among blue pine (pinus wallichiana) communities in hindukush ranges of Swat, Pakistan International Nuclear Information System (INIS) Rahman, I. U.; Khan, N.; Ali, K. 2017-01-01 Pinus wallichiana dominated forest communities, located in the Hindukush ranges of Swat, Pakistan were analysed for variability in the cone and seed traits. The results disclosed significant variability in mean values, critical difference, co-efficient of variation, broad sense heritability, genetic gain and genetic advance. Genotypic variance (Vg) and genotypic coefficient of variance (GCV) were noted to be lower than the corresponding environmental variance (Ve) and environmental coefficient of variability (ECV) for most of the parameters which clearly shows that these traits are under the control of environment. Both Number of male clusters/branch and 100 seeds weight are heritable traits as having higher genotypic variance and genotypic coefficient of variance. Traits like 100 seeds weight, Number of male cluster/branch, number of female cones/tree, female cone weight and number of sterile scales/cone showed moderate to high percentage of heritability indicates that these traits are under strong genetic control. These heritable additive genetic traits can be used for future breeding and tree improvement plans for the species. It is further concluded that the alleged traits should be given priority while selecting superior genotypes. (author) 20. First observations of transient luminous events in Indian sub-continent DEFF Research Database (Denmark) Singh, Rajesh; Maurya, Ajeet K.; Veenadhari, B. 2014-01-01 The article offers information on the initial observations of flashes of lightning discharge observed above thunderstorms. It mentions that the transient luminous events (TLE) are classified on the basis of their geometrical shape and luminosity into Sprites, Halos and Blue Starters. It also focu... 1. A Blue Lagoon Function DEFF Research Database (Denmark) Markvorsen, Steen 2007-01-01 We consider a specific function of two variables whose graph surface resembles a blue lagoon. The function has a saddle point$p$, but when the function is restricted to any given straight line through$p$it has a {\\em{strict local minimum}} along that line at$p$.......We consider a specific function of two variables whose graph surface resembles a blue lagoon. The function has a saddle point$p$, but when the function is restricted to any given straight line through$p$it has a {\\em{strict local minimum}} along that line at$p.... 2. Comparison of clinical outcomes between luminal invasive ductal carcinoma and luminal invasive lobular carcinoma. Science.gov (United States) Adachi, Yayoi; Ishiguro, Junko; Kotani, Haruru; Hisada, Tomoka; Ichikawa, Mari; Gondo, Naomi; Yoshimura, Akiyo; Kondo, Naoto; Hattori, Masaya; Sawaki, Masataka; Fujita, Takashi; Kikumori, Toyone; Yatabe, Yasushi; Kodera, Yasuhiro; Iwata, Hiroji 2016-03-25 The pathological and clinical features of invasive lobular carcinoma (ILC) differ from those of invasive ductal carcinoma (IDC). Several studies have indicated that patients with ILC have a better prognosis than those with ductal carcinoma. However, no previous study has considered the molecular subtypes and histological subtypes of ILC. We compared prognosis between IDC and classical, luminal type ILC and developed prognostic factors for early breast cancer patients with classical luminal ILC. Four thousand one hundred ten breast cancer patients were treated at the Aichi Cancer Center Hospital from 2003 to 2012. We identified 1,661 cases with luminal IDC and 105 cases with luminal classical ILC. We examined baseline characteristics, clinical outcomes, and prognostic factors of luminal ILC. The prognosis of luminal ILC was significantly worse than that of luminal IDC. The rates of 5-year disease free survival (DFS) were 91.9% and 88.4% for patients with luminal IDC and luminal ILC, respectively (P = 0.008). The rates of 5-year overall survival (OS) were 97.6% and 93.1% for patients with luminal IDC and luminal ILC respectively (P = 0.030). Although we analyzed prognosis according to stratification by tumor size, luminal ILC tended to have worse DFS than luminal IDC in the large tumor group. In addition, although our analysis was performed according to matching lymph node status, luminal ILC had a significantly worse DFS and OS than luminal IDC in node-positive patients. Survival curves showed that the prognosis for ILC became worse than IDC over time. Multivariate analysis showed that ILC was an important factor related to higher risk of recurrence of luminal type breast cancer, even when tumor size, lymph node status and histological grade were considered. Luminal ILC had worse outcomes than luminal IDC. Consequently, different treatment approaches should be used for luminal ILC than for luminal IDC. 3. Intra-population variability of ocean acidification impacts on the physiology of Baltic blue mussels (Mytilus edulis): integrating tissue and organism response. Science.gov (United States) Stapp, L S; Thomsen, J; Schade, H; Bock, C; Melzner, F; Pörtner, H O; Lannig, G 2017-05-01 Increased maintenance costs at cellular, and consequently organism level, are thought to be involved in shaping the sensitivity of marine calcifiers to ocean acidification (OA). Yet, knowledge of the capacity of marine calcifiers to undergo metabolic adaptation is sparse. In Kiel Fjord, blue mussels thrive despite periodically high seawater PCO 2 , making this population interesting for studying metabolic adaptation under OA. Consequently, we conducted a multi-generation experiment and compared physiological responses of F1 mussels from 'tolerant' and 'sensitive' families exposed to OA for 1 year. Family classifications were based on larval survival; tolerant families settled at all PCO 2 levels (700, 1120, 2400 µatm) while sensitive families did not settle at the highest PCO 2 (≥99.8% mortality). We found similar filtration rates between family types at the control and intermediate PCO 2 level. However, at 2400 µatm, filtration and metabolic scope of gill tissue decreased in tolerant families, indicating functional limitations at the tissue level. Routine metabolic rates (RMR) and summed tissue respiration (gill and outer mantle tissue) of tolerant families were increased at intermediate PCO 2 , indicating elevated cellular homeostatic costs in various tissues. By contrast, OA did not affect tissue and routine metabolism of sensitive families. However, tolerant mussels were characterised by lower RMR at control PCO 2 than sensitive families, which had variable RMR. This might provide the energetic scope to cover increased energetic demands under OA, highlighting the importance of analysing intra-population variability. The mechanisms shaping such difference in RMR and scope, and thus species' adaptation potential, remain to be identified. 4. The Role of Luminance and Chromaticity on Symmetry Detection Directory of Open Access Journals (Sweden) Chia-Ching Wu 2011-05-01 Full Text Available We investigated the effect of luminance and chromaticity on symmetry detection with the noise masking paradigm. In each trial, a random dot noise mask was presented in both intervals. A symmetric target was randomly presented in one interval while a random dot control was presented in the other. The orientation of the symmetric axis of the target was either 45°or −45° diagonal. The task of the observer was to determine which interval contained a symmetric target. The dots in both the target and the mask was painted with 1 to 4 colors selected from white, black, red, green, blue and yellow. We measured the target density threshold at various noise densities. Our results showed that when the number of the colors in the images was equal, the thresholds were lower in the luminance conditions than in the chromaticity conditions. In addition, the thresholds decreased with the increment of the number of the colors in the images. This suggests that (1 the luminance symmetry detection mechanism is more sensitive than chromaticity one and (2 that, contrasted to the prediction of an uncertainty model, the diversity in color facilitates symmetry detection. 5. Reproducibility of airway luminal size in asthma measured by HRCT. Science.gov (United States) Brown, Robert H; Henderson, Robert J; Sugar, Elizabeth A; Holbrook, Janet T; Wise, Robert A 2017-10-01 Brown RH, Henderson RJ, Sugar EA, Holbrook JT, Wise RA, on behalf of the American Lung Association Airways Clinical Research Centers. Reproducibility of airway luminal size in asthma measured by HRCT. J Appl Physiol 123: 876-883, 2017. First published July 13, 2017; doi:10.1152/japplphysiol.00307.2017.-High-resolution CT (HRCT) is a well-established imaging technology used to measure lung and airway morphology in vivo. However, there is a surprising lack of studies examining HRCT reproducibility. The CPAP Trial was a multicenter, randomized, three-parallel-arm, sham-controlled 12-wk clinical trial to assess the use of a nocturnal continuous positive airway pressure (CPAP) device on airway reactivity to methacholine. The lack of a treatment effect of CPAP on clinical or HRCT measures provided an opportunity for the current analysis. We assessed the reproducibility of HRCT imaging over 12 wk. Intraclass correlation coefficients (ICCs) were calculated for individual airway segments, individual lung lobes, both lungs, and air trapping. The ICC [95% confidence interval (CI)] for airway luminal size at total lung capacity ranged from 0.95 (0.91, 0.97) to 0.47 (0.27, 0.69). The ICC (95% CI) for airway luminal size at functional residual capacity ranged from 0.91 (0.85, 0.95) to 0.32 (0.11, 0.65). The ICC measurements for airway distensibility index and wall thickness were lower, ranging from poor (0.08) to moderate (0.63) agreement. The ICC for air trapping at functional residual capacity was 0.89 (0.81, 0.94) and varied only modestly by lobe from 0.76 (0.61, 0.87) to 0.95 (0.92, 0.97). In stable well-controlled asthmatic subjects, it is possible to reproducibly image unstimulated airway luminal areas over time, by region, and by size at total lung capacity throughout the lungs. Therefore, any changes in luminal size on repeat CT imaging are more likely due to changes in disease state and less likely due to normal variability. NEW & NOTEWORTHY There is a surprising lack 6. Blue gods, blue oil, and blue people. Science.gov (United States) Fairbanks, V F 1994-09-01 Studies of the composition of coal tar, which began in Prussia in 1834, profoundly affected the economies of Germany, Great Britain, India, and the rest of the world, as well as medicine and surgery. Such effects include the collapse of the profits of the British indigo monopoly, the growth in economic power of Germany based on coal tar chemistry, and an economic crisis in India that led to more humane tax laws and, ultimately, the independence of India and the end of the British Empire. Additional consequences were the development of antiseptic surgery and the synthesis of a wide variety of useful drugs that have eradicated infections and alleviated pain. Many of these drugs, particularly the commonly used analgesics, sulfonamides, sulfones, and local anesthetics, are derivatives of aniline, originally called "blue oil" or "kyanol." Some of these aniline derivatives, however, have also caused aplastic anemia, agranulocytosis, and methemoglobinemia (that is, "blue people"). Exposure to aniline drugs, particularly when two or three aniline drugs are taken concurrently, seems to be the commonest cause of methemoglobinemia today. 7. Blue Light Protects Against Temporal Frequency Sensitive Refractive Changes. Science.gov (United States) Rucker, Frances; Britton, Stephanie; Spatcher, Molly; Hanowsky, Stephan 2015-09-01 Time spent outdoors is protective against myopia. The outdoors allows exposure to short-wavelength (blue light) rich sunlight, while indoor illuminants can be deficient at short-wavelengths. In the current experiment, we investigate the role of blue light, and temporal sensitivity, in the emmetropization response. Five-day-old chicks were exposed to sinusoidal luminance modulation of white light (with blue; N = 82) or yellow light (without blue; N = 83) at 80% contrast, at one of six temporal frequencies: 0, 0.2, 1, 2, 5, 10 Hz daily for 3 days. Mean illumination was 680 lux. Changes in ocular components and corneal curvature were measured. Refraction, eye length, and choroidal changes were dependent on the presence of blue light (P light, refraction did not change across frequencies (mean change -0.24 [diopters] D), while in the absence of blue light, we observed a hyperopic shift (>1 D) at high frequencies, and a myopic shift (>-0.6 D) at low frequencies. With blue light there was little difference in eye growth across frequencies (77 μm), while in the absence of blue light, eyes grew more at low temporal frequencies and less at high temporal frequencies (10 vs. 0.2 Hz: 145 μm; P light. Illuminants rich in blue light can protect against myopic eye growth when the eye is exposed to slow changes in luminance contrast as might occur with near work. 8. Comparison of clinical outcomes between luminal invasive ductal carcinoma and luminal invasive lobular carcinoma International Nuclear Information System (INIS) Adachi, Yayoi; Ishiguro, Junko; Kotani, Haruru; Hisada, Tomoka; Ichikawa, Mari; Gondo, Naomi; Yoshimura, Akiyo; Kondo, Naoto; Hattori, Masaya; Sawaki, Masataka; Fujita, Takashi; Kikumori, Toyone; Yatabe, Yasushi; Kodera, Yasuhiro; Iwata, Hiroji 2016-01-01 The pathological and clinical features of invasive lobular carcinoma (ILC) differ from those of invasive ductal carcinoma (IDC). Several studies have indicated that patients with ILC have a better prognosis than those with ductal carcinoma. However, no previous study has considered the molecular subtypes and histological subtypes of ILC. We compared prognosis between IDC and classical, luminal type ILC and developed prognostic factors for early breast cancer patients with classical luminal ILC. Four thousand one hundred ten breast cancer patients were treated at the Aichi Cancer Center Hospital from 2003 to 2012. We identified 1,661 cases with luminal IDC and 105 cases with luminal classical ILC. We examined baseline characteristics, clinical outcomes, and prognostic factors of luminal ILC. The prognosis of luminal ILC was significantly worse than that of luminal IDC. The rates of 5-year disease free survival (DFS) were 91.9 % and 88.4 % for patients with luminal IDC and luminal ILC, respectively (P = 0.008). The rates of 5-year overall survival (OS) were 97.6 % and 93.1 % for patients with luminal IDC and luminal ILC respectively (P = 0.030). Although we analyzed prognosis according to stratification by tumor size, luminal ILC tended to have worse DFS than luminal IDC in the large tumor group. In addition, although our analysis was performed according to matching lymph node status, luminal ILC had a significantly worse DFS and OS than luminal IDC in node-positive patients. Survival curves showed that the prognosis for ILC became worse than IDC over time. Multivariate analysis showed that ILC was an important factor related to higher risk of recurrence of luminal type breast cancer, even when tumor size, lymph node status and histological grade were considered. Luminal ILC had worse outcomes than luminal IDC. Consequently, different treatment approaches should be used for luminal ILC than for luminal IDC. The online version of this article (doi:10.1186/s12885 9. THE PHOTOMETRIC AND SPECTRAL EVOLUTION OF THE 2008 LUMINOUS OPTICAL TRANSIENT IN NGC 300 International Nuclear Information System (INIS) Humphreys, Roberta M.; Davidson, Kris; Bond, Howard E.; Bedin, Luigi R.; Bonanos, Alceste Z.; Berto Monard, L. A. G.; Prieto, José L.; Walter, Frederick M. 2011-01-01 The 2008 optical transient in NGC 300 is one of a growing class of intermediate-luminosity transients that brighten several orders of magnitude from a previously optically obscured state. The origin of their eruptions is not understood. Our multi-wavelength photometry and spectroscopy from maximum light to more than a year later provide a record of its post-eruption behavior. We describe its changing spectral energy distribution, the evolution of its absorption- and emission-line spectrum, the development of a bipolar outflow, and the rapid transition from a dense wind to an optically thin ionized wind. In addition to strong, narrow hydrogen lines, the F-type absorption-line spectrum of the transient is characterized by strong Ca II and [Ca II] emission. The very broad wings of the Ca II triplet and the asymmetric [Ca II] emission lines are due to strong Thomson scattering in the expanding ejecta. Post-maximum, the hydrogen and Ca II lines developed double-peaked emission profiles that we attribute to a bipolar outflow. Between approximately 60 and 100 days after maximum, the F-type absorption spectrum, formed in its dense wind, weakened and the wind became transparent to ionizing radiation. We discuss the probable evolutionary state of the transient and similar objects such as SN 2008S and conclude that they were most likely post-red supergiants or post-asymptotic giant branch stars on a blue loop to warmer temperatures when the eruption occurred. These objects are not luminous blue variables. 10. Signs of depth-luminance covariance in 3-D cluttered scenes. Science.gov (United States) Scaccia, Milena; Langer, Michael S 2018-03-01 In three-dimensional (3-D) cluttered scenes such as foliage, deeper surfaces often are more shadowed and hence darker, and so depth and luminance often have negative covariance. We examined whether the sign of depth-luminance covariance plays a role in depth perception in 3-D clutter. We compared scenes rendered with negative and positive depth-luminance covariance where positive covariance means that deeper surfaces are brighter and negative covariance means deeper surfaces are darker. For each scene, the sign of the depth-luminance covariance was given by occlusion cues. We tested whether subjects could use this sign information to judge the depth order of two target surfaces embedded in 3-D clutter. The clutter consisted of distractor surfaces that were randomly distributed in a 3-D volume. We tested three independent variables: the sign of the depth-luminance covariance, the colors of the targets and distractors, and the background luminance. An analysis of variance showed two main effects: Subjects performed better when the deeper surfaces were darker and when the color of the target surfaces was the same as the color of the distractors. There was also a strong interaction: Subjects performed better under a negative depth-luminance covariance condition when targets and distractors had different colors than when they had the same color. Our results are consistent with a "dark means deep" rule, but the use of this rule depends on the similarity between the color of the targets and color of the 3-D clutter. 11. Luminous Phenomena - A Scientific Investigation of Anomalous Luminous Atmospheric Phenomena Science.gov (United States) Teodorani, M. 2003-12-01 Anomalous atmospheric luminous phenomena reoccur in several locations of Earth, in the form of multi-color light balls characterized by large dimensions, erratic motion, long duration and a correlated electromagnetic field. The author (an astrophysicist) of this book, which is organized as a selection of some of his technical and popularizing papers and seminars, describes and discusses all the efforts that have been done in 10 years, through several missions and a massive data analysis, in order to obtain some scientific explanation of this kind of anomalies, in particular the Hessdalen anomaly in Norway. The following topics are treated in the book: a) geographic archive of the areas of Earth where such phenomena are known to reoccur most often; b) observational techniques of astrophysical kind that have been used to acquire the data; c) main scientific results obtained so far; d) physical interpretation and natural hypothesis vs. ETV hypothesis; e) historical and chronological issues; f) the importance to brindle new energy sources; g) the importance to keep distance from any kind of "ufology". An unpublished chapter is entirely devoted to a detailed scientific investigation project of light phenomena reoccurring on the Ontario lake; the chosen new-generation multi-wavelength sensing instrumentation that is planned to be used in future missions in that specific area, is described together with scientific rationale and planned procedures. The main results, which were obtained in other areas of the world, such as the Arizona desert, USA and the Sibillini Mountains, Italy, are also briefly mentioned. One chapter is entirely dedicated to the presentation of extensive abstracts of technical papers by the author concerning this specific subject. The book is accompanied with a rich source of bibliographic references. 12. Accurate method for luminous transmittance and signal detection quotients measurements in sunglasses lenses Science.gov (United States) Loureiro, A. D.; Gomes, L. M.; Ventura, L. 2018-02-01 The international standard ISO 12312-1 proposes transmittance tests that quantify how dark sunglasses lenses are and whether or not they are suitable for driving. To perform these tests a spectrometer is required. In this study, we present and analyze theoretically an accurate alternative method for performing these measurements using simple components. Using three LEDs and a four-channel sensor we generated weighting functions similar to the standard ones for luminous and traffic lights transmittances. From 89 sunglasses lens spectroscopy data, we calculated luminous transmittance and signal detection quotients using our obtained weighting functions and the standard ones. Mean-difference Tukey plots were used to compare the results. All tested sunglasses lenses were classified in the right category and correctly as suitable or not for driving. The greatest absolute errors for luminous transmittance and red, yellow, green and blue signal detection quotients were 0.15%, 0.17, 0.06, 0.04 and 0.18, respectively. This method will be used in a device capable to perform transmittance tests (visible, traffic lights and ultraviolet (UV)) according to the standard. It is important to measure rightly luminous transmittance and relative visual attenuation quotients to report correctly whether or not sunglasses are suitable for driving. Moreover, standard UV requirements depend on luminous transmittance. 13. Posthuman blues CERN Document Server Tonnies, Mac 2013-01-01 Posthuman Blues, Vol. I is first volume of the edited version of the popular weblog maintained by author Mac Tonnies from 2003 until his tragic death in 2009. Tonnies' blog was a pastiche of his original fiction, reflections on his day-to-day life, trenchant observations of current events, and thoughts on an eclectic range of material he culled from the Internet. What resulted was a remarkably broad portrait of a thoughtful man and the complex times in which he lived, rendered with intellige... 14. Optimal Solution Volume for Luminal Preservation: A Preclinical Study in Porcine Intestinal Preservation. Science.gov (United States) Oltean, M; Papurica, M; Jiga, L; Hoinoiu, B; Glameanu, C; Bresler, A; Patrut, G; Grigorie, R; Ionac, M; Hellström, M 2016-03-01 Rodent studies suggest that luminal solutions alleviate the mucosal injury and prolong intestinal preservation but concerns exist that excessive volumes of luminal fluid may promote tissue edema. Differences in size, structure, and metabolism between rats and humans require studies in large animals before clinical use. Intestinal procurement was performed in 7 pigs. After perfusion with histidine-tryptophan-ketoglutarate (HTK), 40-cm-long segments were cut and filled with 13.5% polyethylene glycol (PEG) 3350 solution as follows: V0 (controls, none), V1 (0.5 mL/cm), V2 (1 mL/cm), V3 (1.5 mL/cm), and V4 (2 mL/cm). Tissue and luminal solutions were sampled after 8, 14, and 24 hours of cold storage (CS). Preservation injury (Chiu score), the apical membrane (ZO-1, brush-border maltase activity), and the electrolyte content in the luminal solution were studied. In control intestines, 8-hour CS in HTK solution resulted in minimal mucosal changes (grade 1) that progressed to significant subepithelial edema (grade 3) by 24 hours. During this time, a gradual loss in ZO-1 was recorded, whereas maltase activity remained unaltered. Moreover, variable degrees of submucosal edema were observed. Luminal introduction of high volumes (2 mL/mL) of PEG solution accelerated the development of the subepithelial edema and submucosal edema, leading to worse histology. However, ZO-1 was preserved better over time than in control intestines (no luminal solution). Maltase activity was reduced in intestines receiving luminal preservation. Luminal sodium content decreased in time and did not differ between groups. This PEG solution protects the apical membrane and the tight-junction proteins but may favor water absorption and tissue (submucosal) edema, and luminal volumes >2 mL/cm may result in worse intestinal morphology. Copyright © 2016 Elsevier Inc. All rights reserved. 15. Daylight calculations using constant luminance curves Energy Technology Data Exchange (ETDEWEB) Betman, E. [CRICYT, Mendoza (Argentina). Laboratorio de Ambiente Humano y Vivienda 2005-02-01 This paper presents a simple method to manually estimate daylight availability and to make daylight calculations using constant luminance curves calculated with local illuminance and irradiance data and the all-weather model for sky luminance distribution developed in the Atmospheric Science Research Center of the University of New York (ARSC) by Richard Perez et al. Work with constant luminance curves has the advantage that daylight calculations include the problem's directionality and preserve the information of the luminous climate of the place. This permits accurate knowledge of the resource and a strong basis to establish conclusions concerning topics related to the energy efficiency and comfort in buildings. The characteristics of the proposed method are compared with the method that uses the daylight factor. (author) 16. EVOLUTION OF THE MOST LUMINOUS DUSTY GALAXIES International Nuclear Information System (INIS) Weedman, Daniel W.; Houck, James R. 2009-01-01 A summary of mid-infrared continuum luminosities arising from dust is given for very luminous galaxies, L IR > 10 12 L sun , with 0.005 0.7 in the 9.7 μm silicate absorption feature (i.e., half of the continuum is absorbed) and having equivalent width of the 6.2 μm polycyclic aromatic hydrocarbon feature ν (8 μm) for the most luminous obscured AGNs is found to scale as (1+z) 2.6 to z = 2.8. For unobscured AGNs, the scaling with redshift is similar, but luminosities νL ν (8 μm) are approximately three times greater for the most luminous sources. Using both obscured and unobscured AGNs having total infrared fluxes from the Infrared Astronomical Satellite, empirical relations are found between νL ν (8 μm) and L IR . Combining these relations with the redshift scaling of luminosity, we conclude that the total infrared luminosities for the most luminous obscured AGNs, L IR (AGN obscured ) in L sun , scale as log L IR (AGN obscured ) = 12.3 ± 0.25 + 2.6(±0.3)log(1+z), and for the most luminous unobscured AGNs, scale as log L IR (AGN1) = 12.6(±0.15) + 2.6(±0.3)log(1+z). We previously determined that the most luminous starbursts scale as log L IR (SB) = 11.8 ± 0.3 + 2.5(±0.3)log(1+z), indicating that the most luminous AGNs are about 10 times more luminous than the most luminous starbursts. Results are consistent with obscured and unobscured AGNs having the same total luminosities with differences arising only from orientation, such that the obscured AGNs are observed through very dusty clouds which extinct about 50% of the intrinsic luminosity at 8 μm. Extrapolations of observable f ν (24 μm) to z = 6 are made using evolution results for these luminous sources. Both obscured and unobscured AGNs should be detected to z ∼ 6 by Spitzer surveys with f ν (24 μm) > 0.3 mJy, even without luminosity evolution for z > 2.5. By contrast, the most luminous starbursts cannot be detected for z > 3, even if luminosity evolution continues beyond z = 2.5. 17. Simultaneous chromatic and luminance human electroretinogram responses. Science.gov (United States) Parry, Neil R A; Murray, Ian J; Panorgias, Athanasios; McKeefry, Declan J; Lee, Barry B; Kremers, Jan 2012-07-01 The parallel processing of information forms an important organisational principle of the primate visual system. Here we describe experiments which use a novel chromatic–achromatic temporal compound stimulus to simultaneously identify colour and luminance specific signals in the human electroretinogram (ERG). Luminance and chromatic components are separated in the stimulus; the luminance modulation has twice the temporal frequency of the chromatic modulation. ERGs were recorded from four trichromatic and two dichromatic subjects (1 deuteranope and 1 protanope). At isoluminance, the fundamental (first harmonic) response was elicited by the chromatic component in the stimulus. The trichromatic ERGs possessed low-pass temporal tuning characteristics, reflecting the activity of parvocellular post-receptoral mechanisms. There was very little first harmonic response in the dichromats' ERGs. The second harmonic response was elicited by the luminance modulation in the compound stimulus and showed, in all subjects, band-pass temporal tuning characteristic of magnocellular activity. Thus it is possible to concurrently elicit ERG responses from the human retina which reflect processing in both chromatic and luminance pathways. As well as providing a clear demonstration of the parallel nature of chromatic and luminance processing in the human retina, the differences that exist between ERGs from trichromatic and dichromatic subjects point to the existence of interactions between afferent post-receptoral pathways that are in operation from the earliest stages of visual processing. 18. The blue supergiant MN18 and its bipolar circumstellar nebula Science.gov (United States) Gvaramadze, V. V.; Kniazev, A. Y.; Bestenlehner, J. M.; Bodensteiner, J.; Langer, N.; Greiner, J.; Grebel, E. K.; Berdnikov, L. N.; Beletsky, Y. 2015-11-01 We report the results of spectrophotometric observations of the massive star MN18 revealed via discovery of a bipolar nebula around it with the Spitzer Space Telescope. Using the optical spectrum obtained with the Southern African Large Telescope, we classify this star as B1 Ia. The evolved status of MN18 is supported by the detection of nitrogen overabundance in the nebula, which implies that it is composed of processed material ejected by the star. We analysed the spectrum of MN18 by using the code CMFGEN, obtaining a stellar effective temperature of ≈21 kK. The star is highly reddened, E(B - V) ≈ 2 mag. Adopting an absolute visual magnitude of MV = -6.8 ± 0.5 (typical of B1 supergiants), MN18 has a luminosity of log L/L⊙ ≈ 5.42 ± 0.30, a mass-loss rate of ≈(2.8-4.5) × 10- 7 M⊙ yr- 1, and resides at a distance of ≈5.6^{+1.5} _{-1.2} kpc. We discuss the origin of the nebula around MN18 and compare it with similar nebulae produced by other blue supergiants in the Galaxy (Sher 25, HD 168625, [SBW2007] 1) and the Large Magellanic Cloud (Sk-69°202). The nitrogen abundances in these nebulae imply that blue supergiants can produce them from the main-sequence stage up to the pre-supernova stage. We also present a K-band spectrum of the candidate luminous blue variable MN56 (encircled by a ring-like nebula) and report the discovery of an OB star at ≈17 arcsec from MN18. The possible membership of MN18 and the OB star of the star cluster Lynga 3 is discussed. 19. Method and apparatus for generating highly luminous flame Energy Technology Data Exchange (ETDEWEB) Gitman, G.M. 1992-05-12 A combustion process and apparatus are provided for generating a variable high temperature, highly luminous flame with low NOx emission by burning gaseous and liquid materials with oxygen and air. More particularly, the invention provides a process in which there is initial control of fuel, oxygen, and air flows and the delivery of the oxidizers to a burner as two oxidizing gases having different oxygen concentrations (for example, pure oxygen and air, or oxygen and oxygen-enriched air). A first oxidizing gas containing a high oxygen concentration is injected as a stream into the central zone of a combustion tunnel or chamber, and part of the fuel (preferably the major part) is injected into the central pyrolysis zone to mix with the first oxidizing gas to create a highly luminous high-temperature flame core containing microparticles of carbon of the proper size for maximum luminosity and high temperature, and a relatively small amount of hydrocarbon radicals. In addition, part of the fuel (preferably the minor part) is injected in a plurality of streams about the flame core to mix with a second oxidizing gas (containing a lower oxygen concentration than the first oxidizing gas) and injecting the second oxidizing mixture about the flame core and the minor fuel flow to mix with the minor fuel flow. This creates a plurality of fuel-lean (oxygen-rich) flames which are directed toward the luminous flame core to form a final flame pattern having high temperature, high luminosity, and low NOx content. 6 figs. 20. The effect of inter-annual variability of consumption, production, trade and climate on crop-related green and blue water footprints and inter-regional virtual water trade: A study for China (1978-2008). Science.gov (United States) Zhuo, La; Mekonnen, Mesfin M; Hoekstra, Arjen Y 2016-05-01 Previous studies into the relation between human consumption and indirect water resources use have unveiled the remote connections in virtual water (VW) trade networks, which show how communities externalize their water footprint (WF) to places far beyond their own region, but little has been done to understand variability in time. This study quantifies the effect of inter-annual variability of consumption, production, trade and climate on WF and VW trade, using China over the period 1978-2008 as a case study. Evapotranspiration, crop yields and green and blue WFs of crops are estimated at a 5 × 5 arc-minute resolution for 22 crops, for each year in the study period, thus accounting for climate variability. The results show that crop yield improvements during the study period helped to reduce the national average WF of crop consumption per capita by 23%, with a decreasing contribution to the total from cereals and increasing contribution from oil crops. The total consumptive WFs of national crop consumption and crop production, however, grew by 6% and 7%, respectively. By 2008, 28% of total water consumption in crop fields in China served the production of crops for export to other regions and, on average, 35% of the crop-related WF of a Chinese consumer was outside its own province. Historically, the net VW within China was from the water-rich South to the water-scarce North, but intensifying North-to-South crop trade reversed the net VW flow since 2000, which amounted 6% of North's WF of crop production in 2008. South China thus gradually became dependent on food supply from the water-scarce North. Besides, during the whole study period, China's domestic inter-regional VW flows went dominantly from areas with a relatively large to areas with a relatively small blue WF per unit of crop, which in 2008 resulted in a trade-related blue water loss of 7% of the national total blue WF of crop production. The case of China shows that domestic trade, as governed by 1. Research on the calibration methods of the luminance parameter of radiation luminance meters Science.gov (United States) Cheng, Weihai; Huang, Biyong; Lin, Fangsheng; Li, Tiecheng; Yin, Dejin; Lai, Lei 2017-10-01 This paper introduces standard diffusion reflection white plate method and integrating sphere standard luminance source method to calibrate the luminance parameter. The paper compares the effects of calibration results by using these two methods through principle analysis and experimental verification. After using two methods to calibrate the same radiation luminance meter, the data obtained verifies the testing results of the two methods are both reliable. The results show that the display value using standard white plate method has fewer errors and better reproducibility. However, standard luminance source method is more convenient and suitable for on-site calibration. Moreover, standard luminance source method has wider range and can test the linear performance of the instruments. 2. Study on the Influence Factors of the Luminous Intensity of the Long Afterglow Luminous Paints Directory of Open Access Journals (Sweden) Zhao Su 2016-01-01 Full Text Available In order to extend the time afterglow luminous powder, enhancement the brightness of luminous paint, this study explore affect long afterglow energy storage luminous paints brightness of the main factors. Luminous paints were prepared with rare earth aluminate long afterglow luminescent powder, first is luminous powder surface modification, then investigate the influence of light emitting powder content, calcium carbonate, titanium dioxide, nano alumina and other fillers on the luminescent properties of the paints. It was concluded that the water resistance of the luminescent powder is better and the brightness can be improved after the modification of anhydrous alcohol. The addition of nano-alumina can improve the brightness of the system, and can effectively enhance the hardness of the paints. In the paints, the two kinds of components of carbonate and titanium dioxide have little effect on the luminescent brightness of the painting. 3. Cataclysmic variables, Hubble-Sandage variables and eta Carinae International Nuclear Information System (INIS) Bath, G.T. 1980-01-01 The Hubble-Sandage variables are the most luminous stars in external galaxies. They were first investigated by Hubble and Sandage (1953) for use as distance indicators. Their main characteristics are high luminosity, blue colour indices, and irregular variability. Spectroscopically they show hydrogen and helium in emission with occasionally weaker FeII and [FeII], and no Balmer jump (Humphreys 1975, 1978). In this respect they closely resemble cataclysmic variables, particularly dwarf novae. In the quiescent state dwarf novae show broad H and HeI, together with a strong UV continuum. In contrast to the spectroscopic similarities, the luminosities could hardly differ more. Rather than being the brightest stars known, quiescent dwarf novae are as faint or fainter than the sun. It is suggested that the close correspondence between the spectral appearance of the two classes combined with the difference in luminosity is well accounted for by a model of Hubble-Sandage variables in which the same physical processes are occurring, but on a larger scale. (Auth.) 4. High luminous flux from single crystal phosphor-converted laser-based white lighting system KAUST Repository Cantore, Michael 2015-12-14 The efficiency droop of light emitting diodes (LEDs) with increasing current density limits the amount of light emitted per wafer area. Since low current densities are required for high efficiency operation, many LED die are needed for high power white light illumination systems. In contrast, the carrier density of laser diodes (LDs) clamps at threshold, so the efficiency of LDs does not droop above threshold and high efficiencies can be achieved at very high current densities. The use of a high power blue GaN-based LD coupled with a single crystal Ce-doped yttrium aluminum garnet (YAG:Ce) sample was investigated for white light illumination applications. Under CW operation, a single phosphor-converted LD (pc-LD) die produced a peak luminous efficacy of 86.7 lm/W at 1.4 A and 4.24 V and a peak luminous flux of 1100 lm at 3.0 A and 4.85 V with a luminous efficacy of 75.6 lm/W. Simulations of a pc-LD confirm that the single crystal YAG:Ce sample did not experience thermal quenching at peak LD operating efficiency. These results show that a single pc-LD die is capable of emitting enough luminous flux for use in a high power white light illumination system. 5. Compact RGBY light sources with high luminance for laser display applications Science.gov (United States) Paschke, Katrin; Blume, Gunnar; Werner, Nils; Müller, André; Sumpf, Bernd; Pohl, Johannes; Feise, David; Ressel, Peter; Sahm, Alexander; Bege, Roland; Hofmann, Julian; Jedrzejczyk, Daniel; Tränkle, Günther 2018-02-01 Watt-class visible laser light with a high luminance can be created with high-power GaAs-based lasers either directly in the red spectral region or using single-pass second harmonic generation (SHG) for the colors in the blue-yellow spectral region. The concepts and results of red- and near infrared-emitting distributed Bragg reflector tapered lasers and master oscillator power amplifier systems as well as their application for SHG bench-top experiments and miniaturized modules are presented. Examples of these high-luminance light sources aiming at different applications such as flying spot display or holographic 3D cinema are discussed in more detail. The semiconductor material allows an easy adaptation of the wavelength allowing techniques such as six-primary color 3D projection or color space enhancement by adding a fourth yellow color. 6. A pocket-sized luminance meter. NARCIS (Netherlands) Schreuder, D.A. 1964-01-01 In many case the light technician will feel the want of assessing the luminance of certain surfaces within his field of view in a quick and convenient manner. The measurement need not be very accurate, but it should be carried out with an apparatus so small that it can easily be taken along 7. Ecology and biology of luminous bacteria in the Arabian Sea Digital Repository Service at National Institute of Oceanography (India) Ramaiah, N.; Chandramohan, D. Extensive studies on occurrence, distribution and species composition of luminous bacteria in the Arabian Sea were carried out from various habitats. Luminous bacterial population was by far the highest in the environs of the Arabian Sea... 8. Underlying mechanisms of transient luminous events: a review Directory of Open Access Journals (Sweden) V. V. Surkov 2012-08-01 Full Text Available Transient luminous events (TLEs occasionally observed above a strong thunderstorm system have been the subject of a great deal of research during recent years. The main goal of this review is to introduce readers to recent theories of electrodynamics processes associated with TLEs. We examine the simplest versions of these theories in order to make their physics as transparent as possible. The study is begun with the conventional mechanism for air breakdown at stratospheric and mesospheric altitudes. An electron impact ionization and dissociative attachment to neutrals are discussed. A streamer size and mobility of electrons as a function of altitude in the atmosphere are estimated on the basis of similarity law. An alternative mechanism of air breakdown, runaway electron mechanism, is discussed. In this section we focus on a runaway breakdown field, characteristic length to increase avalanche of runaway electrons and on the role played by fast seed electrons in generation of the runaway breakdown. An effect of thunderclouds charge distribution on initiation of blue jets and gigantic jets is examined. A model in which the blue jet is treated as upward-propagating positive leader with a streamer zone/corona on the top is discussed. Sprite models based on streamer-like mechanism of air breakdown in the presence of atmospheric conductivity are reviewed. To analyze conditions for sprite generation, thunderstorm electric field arising just after positive cloud-to-ground stroke is compared with the thresholds for propagation of positively/negatively charged streamers and with runway breakdown. Our own estimate of tendril's length at the bottom of sprite is obtained to demonstrate that the runaway breakdown can trigger the streamer formation. In conclusion we discuss physical mechanisms of VLF (very low frequency and ELF (extremely low frequency phenomena associated with sprites. 9. Luminance-based specular gloss characterization OpenAIRE Leloup, Frédéric; Pointer, Michael R.; Dutré, Philip; Hanselaer, Peter 2011-01-01 Gloss is a feature of visual appearance that arises from the directionally selective reflection of light incident on a surface. Especially when a distinct reflected image is perceptible, the luminance distribution of the illumination scene above the sample can strongly influence the gloss perception. For this reason, industrial glossmeters do not provide a satisfactory gloss estimation of high-gloss surfaces. In this study, the influence of the conditions of illumination on specular ... 10. Luminance-based specular gloss characterization. Science.gov (United States) Leloup, Frédéric B; Pointer, Michael R; Dutré, Philip; Hanselaer, Peter 2011-06-01 Gloss is a feature of visual appearance that arises from the directionally selective reflection of light incident on a surface. Especially when a distinct reflected image is perceptible, the luminance distribution of the illumination scene above the sample can strongly influence the gloss perception. For this reason, industrial glossmeters do not provide a satisfactory gloss estimation of high-gloss surfaces. In this study, the influence of the conditions of illumination on specular gloss perception was examined through a magnitude estimation experiment in which 10 observers took part. A light booth with two light sources was utilized: the mirror image of only one source being visible in reflection by the observer. The luminance of both the reflected image and the adjacent sample surface could be independently varied by separate adjustment of the intensity of the two light sources. A psychophysical scaling function was derived, relating the visual gloss estimations to the measured luminance of both the reflected image and the off-specular sample background. The generalization error of the model was estimated through a validation experiment performed by 10 other observers. In result, a metric including both surface and illumination properties is provided. Based on this metric, improved gloss evaluation methods and instruments could be developed. 11. Blue-Green Algae Science.gov (United States) ... that taking a specific blue-green algae product (Super Blue-Green Algae, Cell Tech, Klamath Falls, OR) ... system. Premenstrual syndrome (PMS). Depression. Digestion. Heart disease. Memory. Wound healing. Other conditions. More evidence is needed ... 12. Luminance and chromatic signals interact differently with melanopsin activation to control the pupil light response. Science.gov (United States) Barrionuevo, Pablo A; Cao, Dingcai 2016-09-01 Intrinsically photosensitive retinal ganglion cells (ipRGCs) express the photopigment melanopsin. These cells receive afferent inputs from rods and cones, which provide inputs to the postreceptoral visual pathways. It is unknown, however, how melanopsin activation is integrated with postreceptoral signals to control the pupillary light reflex. This study reports human flicker pupillary responses measured using stimuli generated with a five-primary photostimulator that selectively modulated melanopsin, rod, S-, M-, and L-cone excitations in isolation, or in combination to produce postreceptoral signals. We first analyzed the light adaptation behavior of melanopsin activation and rod and cones signals. Second, we determined how melanopsin is integrated with postreceptoral signals by testing with cone luminance, chromatic blue-yellow, and chromatic red-green stimuli that were processed by magnocellular (MC), koniocellular (KC), and parvocellular (PC) pathways, respectively. A combined rod and melanopsin response was also measured. The relative phase of the postreceptoral signals was varied with respect to the melanopsin phase. The results showed that light adaptation behavior for all conditions was weaker than typical Weber adaptation. Melanopsin activation combined linearly with luminance, S-cone, and rod inputs, suggesting the locus of integration with MC and KC signals was retinal. The melanopsin contribution to phasic pupil responses was lower than luminance contributions, but much higher than S-cone contributions. Chromatic red-green modulation interacted with melanopsin activation nonlinearly as described by a "winner-takes-all" process, suggesting the integration with PC signals might be mediated by a postretinal site. 13. Influence of Spatial and Chromatic Noise on Luminance Discrimination. Science.gov (United States) Miquilini, Leticia; Walker, Natalie A; Odigie, Erika A; Guimarães, Diego Leite; Salomão, Railson Cruz; Lacerda, Eliza Maria Costa Brito; Cortes, Maria Izabel Tentes; de Lima Silveira, Luiz Carlos; Fitzgerald, Malinda E C; Ventura, Dora Fix; Souza, Givago Silva 2017-12-05 Pseudoisochromatic figures are designed to base discrimination of a chromatic target from a background solely on the chromatic differences. This is accomplished by the introduction of luminance and spatial noise thereby eliminating these two dimensions as cues. The inverse rationale could also be applied to luminance discrimination, if spatial and chromatic noise are used to mask those cues. In this current study estimate of luminance contrast thresholds were conducted using a novel stimulus, based on the use of chromatic and spatial noise to mask the use of these cues in a luminance discrimination task. This was accomplished by presenting stimuli composed of a mosaic of circles colored randomly. A Landolt-C target differed from the background only by the luminance. The luminance contrast thresholds were estimated for different chromatic noise saturation conditions and compared to luminance contrast thresholds estimated using the same target in a non-mosaic stimulus. Moreover, the influence of the chromatic content in the noise on the luminance contrast threshold was also investigated. Luminance contrast threshold was dependent on the chromaticity noise strength. It was 10-fold higher than thresholds estimated from non-mosaic stimulus, but they were independent of colour space location in which the noise was modulated. The present study introduces a new method to investigate luminance vision intended for both basic science and clinical applications. 14. Super-luminous Type II supernovae powered by magnetars Science.gov (United States) Dessart, Luc; Audit, Edouard 2018-05-01 Magnetar power is believed to be at the origin of numerous super-luminous supernovae (SNe) of Type Ic, arising from compact, hydrogen-deficient, Wolf-Rayet type stars. Here, we investigate the properties that magnetar power would have on standard-energy SNe associated with 15-20 M⊙ supergiant stars, either red (RSG; extended) or blue (BSG; more compact). We have used a combination of Eulerian gray radiation-hydrodynamics and non-LTE steady-state radiative transfer to study their dynamical, photometric, and spectroscopic properties. Adopting magnetar fields of 1, 3.5, 7 × 1014 G and rotational energies of 0.4, 1, and 3 × 1051 erg, we produce bolometric light curves with a broad maximum covering 50-150 d and a magnitude of 1043-1044 erg s-1. The spectra at maximum light are analogous to those of standard SNe II-P but bluer. Although the magnetar energy is channelled in equal proportion between SN kinetic energy and SN luminosity, the latter may be boosted by a factor of 10-100 compared to a standard SN II. This influence breaks the observed relation between brightness and ejecta expansion rate of standard Type II SNe. Magnetar energy injection also delays recombination and may even cause re-ionization, with a reversal in photospheric temperature and velocity. Depositing the magnetar energy in a narrow mass shell at the ejecta base leads to the formation of a dense shell at a few 1000 km s-1, which causes a light-curve bump at the end of the photospheric phase. Depositing this energy over a broad range of mass in the inner ejecta, to mimic the effect of multi-dimensional fluid instabilities, prevents the formation of a dense shell and produces an earlier-rising and smoother light curve. The magnetar influence on the SN radiation is generally not visible prior to 20-30 d, during which one may discern a BSG from a RSG progenitor. We propose a magnetar model for the super-luminous Type II SN OGLE-SN14-073. 15. Effects of absolute luminance and luminance contrast on visual search in low mesopic environments. Science.gov (United States) Hunter, Mathew; Godde, Ben; Olk, Bettina 2018-03-26 Diverse adaptive visual processing mechanisms allow us to complete visual search tasks in a wide visual photopic range (>0.6 cd/m 2 ). Whether search strategies or mechanisms known from this range extend below, in the mesopic and scotopic luminance spectra (search in more complex-feature and conjunction-search paradigms. The results verify the previously reported deficiency windows defined by an interaction of base luminance and luminance contrast for more complex visual-search tasks. Based on significant regression analyses, a more precise definition of the magnitude of contribution of different contrast parameters. Characterized feature search patterns had approximately a 2.5:1 ratio of contribution from the Michelson contrast property relative to Weber contrast, whereas the ratio was approximately 1:1 in a serial-search condition. The results implicate near-complete magnocellular isolation in a visual-search paradigm that has yet to be demonstrated. Our analyses provide a new method of characterizing visual search and the first insight in its underlying mechanisms in luminance environments in the low mesopic and scotopic spectra. 16. Standard deviation of luminance distribution affects lightness and pupillary response. Science.gov (United States) Kanari, Kei; Kaneko, Hirohiko 2014-12-01 We examined whether the standard deviation (SD) of luminance distribution serves as information of illumination. We measured the lightness of a patch presented in the center of a scrambled-dot pattern while manipulating the SD of the luminance distribution. Results showed that lightness decreased as the SD of the surround stimulus increased. We also measured pupil diameter while viewing a similar stimulus. The pupil diameter decreased as the SD of luminance distribution of the stimuli increased. We confirmed that these results were not obtained because of the increase of the highest luminance in the stimulus. Furthermore, results of field measurements revealed a correlation between the SD of luminance distribution and illuminance in natural scenes. These results indicated that the visual system refers to the SD of the luminance distribution in the visual stimulus to estimate the scene illumination. 17. Luminance cues constrain chromatic blur discrimination in natural scene stimuli. Science.gov (United States) Sharman, Rebecca J; McGraw, Paul V; Peirce, Jonathan W 2013-03-22 Introducing blur into the color components of a natural scene has very little effect on its percept, whereas blur introduced into the luminance component is very noticeable. Here we quantify the dominance of luminance information in blur detection and examine a number of potential causes. We show that the interaction between chromatic and luminance information is not explained by reduced acuity or spatial resolution limitations for chromatic cues, the effective contrast of the luminance cue, or chromatic and achromatic statistical regularities in the images. Regardless of the quality of chromatic information, the visual system gives primacy to luminance signals when determining edge location. In natural viewing, luminance information appears to be specialized for detecting object boundaries while chromatic information may be used to determine surface properties. 18. SURVEY OF THE ENTOMOFAUNA THROUGH LUMINOUS TRAP Directory of Open Access Journals (Sweden) V. R. Andrade Neto 2014-09-01 Full Text Available The demand for forest-based raw materials for energy, construction, paper pulp and the pressure to comply with legal requirements concerning environmental legislation, for example, the replacement of the permanent preservation area, legal reserve and recovery of degraded area, leads to encourage the production of healthy seedlings in a health status to do not compromise their future production. The present study aimed to survey the entomofauna population using the “Luiz de Queiroz” model of luminous trap, with white and red fluorescent lamps. The experiment was conducted at the nursery “Flora Sinop” in Sinop – MT. The survey was conducted weekly between the months of April to July 2010, totaling 4 months sand, 32 samples collected. The orders Hemiptera and Coleoptera showed the highest number of individuals captured, either in attraction with white or red light. It was captured 10.089 individuals, 9.339 collected under the influence of white light, representing 92,56%, and 750 with red light, only 7,44% of the total. The white light luminous trap possessed greater efficiency in the attraction of insects when compared with the red light trap. 19. Blue Emission in Proteins OpenAIRE Sarkar, Sohini; Sengupta, Abhigyan; Hazra, Partha; Mandal, Pankaj 2014-01-01 Recent literatures reported blue-green emission from amyloid fibril as exclusive signature of fibril formation. This unusual visible luminescence is regularly used to monitor fibril growth. Blue-green emission has also been observed in crystalline protein and in solution. However, the origin of this emission is not known exactly. Our spectroscopic study of serum proteins reveals that the blue-green emission is a property of protein monomer. Evidences suggest that semiconductor-like band struc... 20. White-electroluminescent device with horizontally patterned blue/yellow phosphor-layer structure International Nuclear Information System (INIS) Won Park, Boo; Sik Choi, Nam; Won Park, Kwang; Mo Son, So; Kim, Jong Su; Kyun Shon, Pong 2007-01-01 White-electroluminescent (EL) devices with stripe-patterned and square-patterned phosphor-layer structures are fabricated through a screen printing method: electrode/BaTiO 3 insulator layer/patterned blue ZnS:Cu, Cl and yellow ZnS:Cu, Mn phosphor layer/ITO PET substrate. The luminous intensities of EL devices with stripe-patterned and square-patterned phosphor-layer structures are 33% and 23% higher than a conventional device with the phosphor-layer structure without any patterns using the phosphor blend. It can be explained in terms of the absorption of the emitted blue light of blue phosphor layer by the yellow-emitting phosphor layer. The EL device of our patterned phosphor-layer structure gives the possibility to enhance the luminance 1. Chromatic blur perception in the presence of luminance contrast. Science.gov (United States) Jennings, Ben J; Kingdom, Frederick A A 2017-06-01 Hel-Or showed that blurring the chromatic but not the luminance layer of an image of a natural scene failed to elicit any impression of blur. Subsequent studies have suggested that this effect is due either to chromatic blur being masked by spatially contiguous luminance edges in the scene (Journal of Vision 13 (2013) 14), or to a relatively compressed transducer function for chromatic blur (Journal of Vision 15 (2015) 6). To test between the two explanations we conducted experiments using as stimuli both images of natural scenes as well as simple edges. First, we found that in color-and-luminance images of natural scenes more chromatic blur was needed to perceptually match a given level of blur in an isoluminant, i.e. colour-only scene. However, when the luminance layer in the scene was rotated relative to the chromatic layer, thus removing the colour-luminance edge correlations, the matched blur levels were near equal. Both results are consistent with Sharman et al.'s explanation. Second, when observers matched the blurs of luminance-only with isoluminant scenes, the matched blurs were equal, against Kingdom et al.'s prediction. Third, we measured the perceived blur in a square-wave as a function of (i) contrast (ii) number of luminance edges and (iii) the relative spatial phase between the colour and luminance edges. We found that the perceived chromatic blur was dependent on both relative phase and the number of luminance edges, or dependent on the luminance contrast if only a single edge is present. We conclude that this Hel-Or effect is largely due to masking of chromatic blur by spatially contiguous luminance edges. Copyright © 2017 Elsevier Ltd. All rights reserved. 2. SN REFSDAL: CLASSIFICATION AS A LUMINOUS AND BLUE SN 1987A-LIKE TYPE II SUPERNOVA Energy Technology Data Exchange (ETDEWEB) Kelly, P. L.; Filippenko, A. V.; Graham, M. L. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Brammer, G.; Strolger, L.-G.; Riess, A. G. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Selsing, J.; Hjorth, J.; Christensen, L. [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen (Denmark); Foley, R. J. [Department of Physics, University of Illinois at Urbana-Champaign, 1110 W. Green Street, Urbana, IL 61801 (United States); Rodney, S. A. [Department of Physics and Astronomy, University of South Carolina, 712 Main St., Columbia, SC 29208 (United States); Treu, T. [University of California, Los Angeles, CA 90095 (United States); Steidel, C. C.; Strom, A.; Zitrin, A. [California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Schmidt, K. B.; McCully, C. [Department of Physics, University of California, Santa Barbara, CA 93106-9530 (United States); Bradač, M. [University of California, Davis, 1 Shields Avenue, Davis, CA 95616 (United States); Jha, S. W. [Department of Physics and Astronomy, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 (United States); Graur, O., E-mail: pkelly@astro.berkeley.edu [Center for Cosmology and Particle Physics, New York University, New York, NY 10003 (United States); and others 2016-11-10 We have acquired Hubble Space Telescope (HST) and Very Large Telescope near-infrared spectra and images of supernova (SN) Refsdal after its discovery as an Einstein cross in fall 2014. The HST light curve of SN Refsdal has a shape consistent with the distinctive, slowly rising light curves of SN 1987A-like SNe, and we find strong evidence for a broad H α P-Cygni profile and Na I D absorption in the HST grism spectrum at the redshift ( z = 1.49) of the spiral host galaxy. SNe IIn, largely powered by circumstellar interaction, could provide a good match to the light curve of SN Refsdal, but the spectrum of a SN IIn would not show broad and strong H α and Na I D absorption. From the grism spectrum, we measure an H α expansion velocity consistent with those of SN 1987A-like SNe at a similar phase. The luminosity, evolution, and Gaussian profile of the H α emission of the WFC3 and X-shooter spectra, separated by ∼2.5 months in the rest frame, provide additional evidence that supports the SN 1987A-like classification. In comparison with other examples of SN 1987A-like SNe, photometry of SN Refsdal favors bluer B - V and V - R colors and one of the largest luminosities for the assumed range of potential magnifications. The evolution of the light curve at late times will provide additional evidence about the potential existence of any substantial circumstellar material. Using MOSFIRE and X-shooter spectra, we estimate a subsolar host-galaxy metallicity (8.3 ± 0.1 dex and <8.4 dex, respectively) near the explosion site. 3. VizieR Online Data Catalog: Spectroscopy of luminous compact blue galaxies (Crawford+, 2016) Science.gov (United States) Crawford, S. M.; Wirth, G. D.; Bershady, M. A.; Randriamampandry, S. M. 2017-10-01 Deep imaging data in UBRIz and two narrow bands were obtained with the Mini-Mosaic camera from the WIYN 3.5 m telescope for all five clusters between 1999 October and 2004 June. We obtained spectroscopic observations for a sample of cluster star-forming galaxies with the DEIMOS, Faber et al. 2003 on the Keck II Telescope during 2005 October and 2007 April. The narrow-band filters were specifically designed to detect [OII] λ3727 at the redshift of each cluster. All of the clusters have been the target of extensive observations with the HST, primarily using either WFPC2 or the Advanced Camera for Surveys (ACS). For all measurements, we have attempted to select data taken in a filter closest to the rest-frame B band. We have employed ACS imaging data whenever possible and substituted WFPC2 images only when required. For clusters observed in the far-infrared regime by the Spitzer Space Telescope, we extracted MIPS 24μm flux densities, S24, from images obtained through the Enhanced Imaging Products archive. (2 data files). 4. THE MOST LUMINOUS GALAXIES DISCOVERED BY WISE Energy Technology Data Exchange (ETDEWEB) Tsai, Chao-Wei; Eisenhardt, Peter R. M.; Stern, Daniel; Moustakas, Leonidas A. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr., Pasadena, CA 91109 (United States); Wu, Jingwen; Wright, Edward L. [Department of Physics and Astronomy, UCLA, Los Angeles, CA 90095-1547 (United States); Assef, Roberto J. [Núcleo de Astronomía de la Facultad deIngeniería, Universidad Diego Portales, Av. Ejército Libertador 441, Santiago (Chile); Blain, Andrew W. [Department of Physics and Astronomy, University of Leicester, 1 University Road, Leicester, LE1 7RH (United Kingdom); Bridge, Carrie R.; Sayers, Jack [Division of Physics, Math, and Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States); Benford, Dominic J.; Leisawitz, David T. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Cutri, Roc M.; Masci, Frank J.; Yan, Lin [Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125 (United States); Griffith, Roger L. [Department of Astronomy and Astrophysics, The Pennsylvania State University, 525 Davey Lab, University Park, PA 16802 (United States); Jarrett, Thomas H. [Astronomy Department, University of Cape Town, Private Bag X3, Rondebosch 7701 (South Africa); Lonsdale, Carol J. [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903 (United States); Petty, Sara M. [Department of Physics, Virginia Tech, Blacksburg, VA 24061 (United States); Stanford, S. Adam, E-mail: Chao-Wei.Tsai@jpl.nasa.gov [Department of Physics, University of California Davis, One Shields Avenue, Davis, CA 95616 (United States); and others 2015-06-01 We present 20 Wide-field Infrared Survey Explorer (WISE)-selected galaxies with bolometric luminosities L{sub bol} > 10{sup 14} L{sub ☉}, including five with infrared luminosities L{sub IR} ≡ L{sub (rest} {sub 8–1000} {sub μm)} > 10{sup 14} L{sub ☉}. These “extremely luminous infrared galaxies,” or ELIRGs, were discovered using the “W1W2-dropout” selection criteria which requires marginal or non-detections at 3.4 and 4.6 μm (W1 and W2, respectively) but strong detections at 12 and 22 μm in the WISE survey. Their spectral energy distributions are dominated by emission at rest-frame 4–10 μm, suggesting that hot dust with T{sub d} ∼ 450 K is responsible for the high luminosities. These galaxies are likely powered by highly obscured active galactic nuclei (AGNs), and there is no evidence suggesting these systems are beamed or lensed. We compare this WISE-selected sample with 116 optically selected quasars that reach the same L{sub bol} level, corresponding to the most luminous unobscured quasars in the literature. We find that the rest-frame 5.8 and 7.8 μm luminosities of the WISE-selected ELIRGs can be 30%–80% higher than that of the unobscured quasars. The existence of AGNs with L{sub bol} > 10{sup 14} L{sub ☉} at z > 3 suggests that these supermassive black holes are born with large mass, or have very rapid mass assembly. For black hole seed masses ∼10{sup 3} M{sub ☉}, either sustained super-Eddington accretion is needed, or the radiative efficiency must be <15%, implying a black hole with slow spin, possibly due to chaotic accretion. 5. Dermatoscopy of blue vitiligo. Science.gov (United States) Chandrashekar, L 2009-07-01 Blue vitiligo is a distinct variant of vitiligo characterized by a blue-grey appearance of the skin, which corresponds histologically with absence of epidermal melanocytes and presence of numerous dermal melanophages. A 23-year-old woman of Indian origin with Fitzpatrick skin type V presented with a 1-month history of normoaesthetic depigmented macules over the right forearm, dorsa of the hands and right areola. The macule over the right forearm had a bluish tinge. A clinical diagnosis of vitiligo vulgaris with blue vitiligo was made. Dermatoscopy of the interface between the blue macule and the hypopigmented macule revealed a linear depigmented macule in the centre with multiple blue dots and absence of epidermal melanin on the side of the blue macule, and reticular pigmentation with a few depigmented macules and scattered blue dots over the side of the hypopigmented macule. Blue vitiligo was described previously in a patient seropositive for human immunodeficiency virus, and believed to represent postinflammatory hyperpigmentation in areas bordering the vitiliginous patches as a result of psoralen ultraviolet A treatment. This case is unusual because of its rarity and the description of the associated dermatoscopical findings. 6. Blue Ocean Thinking Science.gov (United States) Orem, Donna 2016-01-01 This article describes a concept called the "blue ocean thinking strategy," developed by W. Chan Kim and Renée Mauborgne, professors at INSEAD, an international graduate school of business in France. The "blue ocean" thinking strategy considers opportunities to create new markets for services, rather than focusing solely on… 7. Covariation of Color and Luminance Facilitate Object Individuation in Infancy Science.gov (United States) Woods, Rebecca J.; Wilcox, Teresa 2010-01-01 The ability to individuate objects is one of our most fundamental cognitive capacities. Recent research has revealed that when objects vary in color or luminance alone, infants fail to individuate those objects until 11.5 months. However, color and luminance frequently covary in the natural environment, thus providing a more salient and reliable… 8. Luminous flux and colour maintenance investigation of integrated LED lamps DEFF Research Database (Denmark) Corell, Dennis Dan; Thorseth, Anders; Dam-Hansen, Carsten 2014-01-01 This article will present an investigation of the luminous flux and colour maintenance of white LED based retrofit lamps. The study includes 23 different types of integrated LED lamps, covering 18 directional and 5 non-directional. Luminous flux and colour data for operation up to 20000 h has been... 9. HIGH-DENSITY CIRCUMSTELLAR INTERACTION IN THE LUMINOUS TYPE IIn SN 2010jl: THE FIRST 1100 DAYS International Nuclear Information System (INIS) Fransson, Claes; Ergon, Mattias; Sollerman, Jesper; Challis, Peter J.; Kirshner, Robert P.; Marion, G. H.; Milisavljevic, Dan; Friedman, Andrew S.; Chornock, Ryan; Czekala, Ian; Soderberg, Alicia; Chevalier, Roger A.; France, Kevin; Smith, Nathan; Bufano, Filomena; Kangas, Tuomas; Larsson, Josefin; Mattila, Seppo; Benetti, Stefano 2014-01-01 Hubble Space Telescope and ground-based observations of the Type IIn supernova (SN) 2010jl are analyzed, including photometry and spectroscopy in the ultraviolet, optical, and near-IR bands, 26-1128 days after first detection. At maximum, the bolometric luminosity was ∼3 × 10 43 erg s –1 and even at 850 days exceeds 10 42 erg s –1 . A near-IR excess, dominating after 400 days, probably originates in dust in the circumstellar medium (CSM). The total radiated energy is ≳ 6.5 × 10 50 erg, excluding the dust component. The spectral lines can be separated into one broad component that is due to electron scattering and one narrow with expansion velocity ∼100 km s –1 from the CSM. The broad component is initially symmetric around zero velocity but becomes blueshifted after ∼50 days, while remaining symmetric about a shifted centroid velocity. Dust absorption in the ejecta is unlikely to explain the line shifts, and we attribute the shift instead to acceleration by the SN radiation. From the optical lines and the X-ray and dust properties, there is strong evidence for large-scale asymmetries in the CSM. The ultraviolet lines indicate CNO processing in the progenitor, while the optical shows a number of narrow coronal lines excited by the X-rays. The bolometric light curve is consistent with a radiative shock in an r –2 CSM with a mass-loss rate of M-dot ∼0.1 M ⊙ yr −1 . The total mass lost is ≳ 3 M ☉ . These properties are consistent with the SN expanding into a CSM characteristic of a luminous blue variable progenitor with a bipolar geometry. The apparent absence of nuclear processing is attributed to a CSM that is still opaque to electron scattering 10. HIGH-DENSITY CIRCUMSTELLAR INTERACTION IN THE LUMINOUS TYPE IIn SN 2010jl: THE FIRST 1100 DAYS Energy Technology Data Exchange (ETDEWEB) Fransson, Claes; Ergon, Mattias; Sollerman, Jesper [Oskar Klein Centre, Department of Astronomy, Stockholm University, AlbaNova, SE-106 91 Stockholm (Sweden); Challis, Peter J.; Kirshner, Robert P.; Marion, G. H.; Milisavljevic, Dan; Friedman, Andrew S.; Chornock, Ryan; Czekala, Ian; Soderberg, Alicia [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Chevalier, Roger A. [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904 (United States); France, Kevin [CASA, University of Colorado, 593UCB Boulder, CO 80309-0593 (United States); Smith, Nathan [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Bufano, Filomena [Departamento de Ciencias Fisicas, Universidad Andres Bello, Avda. Republica 252, Santiago (Chile); Kangas, Tuomas [Tuorla Observatory, University of Turku, Väisäläntie 20 FI-21500 Piikkiö (Finland); Larsson, Josefin [KTH, Department of Physics, and the Oskar Klein Centre, AlbaNova, SE-106 91 Stockholm (Sweden); Mattila, Seppo [Finnish Centre for Astronomy with ESO (FINCA), University of Turku, Väisäläntie 20 FI-21500 Piikkiö (Finland); Benetti, Stefano [INAF-Osservatorio Astronomico di Padova, Vicolo dellOsservatorio 5, I-35122 Padova (Italy) 2014-12-20 Hubble Space Telescope and ground-based observations of the Type IIn supernova (SN) 2010jl are analyzed, including photometry and spectroscopy in the ultraviolet, optical, and near-IR bands, 26-1128 days after first detection. At maximum, the bolometric luminosity was ∼3 × 10{sup 43} erg s{sup –1} and even at 850 days exceeds 10{sup 42} erg s{sup –1}. A near-IR excess, dominating after 400 days, probably originates in dust in the circumstellar medium (CSM). The total radiated energy is ≳ 6.5 × 10{sup 50} erg, excluding the dust component. The spectral lines can be separated into one broad component that is due to electron scattering and one narrow with expansion velocity ∼100 km s{sup –1} from the CSM. The broad component is initially symmetric around zero velocity but becomes blueshifted after ∼50 days, while remaining symmetric about a shifted centroid velocity. Dust absorption in the ejecta is unlikely to explain the line shifts, and we attribute the shift instead to acceleration by the SN radiation. From the optical lines and the X-ray and dust properties, there is strong evidence for large-scale asymmetries in the CSM. The ultraviolet lines indicate CNO processing in the progenitor, while the optical shows a number of narrow coronal lines excited by the X-rays. The bolometric light curve is consistent with a radiative shock in an r {sup –2} CSM with a mass-loss rate of M-dot ∼0.1 M{sub ⊙} yr{sup −1}. The total mass lost is ≳ 3 M {sub ☉}. These properties are consistent with the SN expanding into a CSM characteristic of a luminous blue variable progenitor with a bipolar geometry. The apparent absence of nuclear processing is attributed to a CSM that is still opaque to electron scattering. 11. Blue ocean strategy. Science.gov (United States) Kim, W Chan; Mauborgne, Renée 2004-10-01 Despite a long-term decline in the circus industry, Cirque du Soleil profitably increased revenue 22-fold over the last ten years by reinventing the circus. Rather than competing within the confines of the existing industry or trying to steal customers from rivals, Cirque developed uncontested market space that made the competition irrelevant. Cirque created what the authors call a blue ocean, a previously unknown market space. In blue oceans, demand is created rather than fought over. There is ample opportunity for growth that is both profitable and rapid. In red oceans--that is, in all the industries already existing--companies compete by grabbing for a greater share of limited demand. As the market space gets more crowded, prospects for profits and growth decline. Products turn into commodities, and increasing competition turns the water bloody. There are two ways to create blue oceans. One is to launch completely new industries, as eBay did with online auctions. But it's much more common for a blue ocean to be created from within a red ocean when a company expands the boundaries of an existing industry. In studying more than 150 blue ocean creations in over 30 industries, the authors observed that the traditional units of strategic analysis--company and industry--are of limited use in explaining how and why blue oceans are created. The most appropriate unit of analysis is the strategic move, the set of managerial actions and decisions involved in making a major market-creating business offering. Creating blue oceans builds brands. So powerful is blue ocean strategy, in fact, that a blue ocean strategic move can create brand equity that lasts for decades. 12. Densities, cellulases, alginate and pectin lyases of luminous and other heterotrophic bacteria associated with marine algae Digital Repository Service at National Institute of Oceanography (India) Ramaiah, N.; Chandramohan, D. Epiphytic luminous and non-luminous bacteria were determined quantitatively for eight intertidal algal species from rocky beaches of Goa and Lakshadweep coral reef lagoon. Luminous bacteria were present on all eight algal species and contributed 2... 13. A Practical Device for Measuring the Luminance Distribution Directory of Open Access Journals (Sweden) Thijs Kruisselbrink 2017-06-01 Full Text Available Various applications in building lighting such as automated daylight systems, dynamic lighting control systems, lighting simulations, and glare analyzes can be optimized using information on the actual luminance distributions of the surroundings. Currently, commercially available luminance distribution measurement devices are often not suitable for these kind of applications or simply too expensive for broad application. This paper describes the development of a practical and autonomous luminance distribution measurement device based on a credit card-sized single-board computer and a camera system. The luminance distribution was determined by capturing High Dynamic Range images and translating the RGB information to the CIE XYZ color space. The High Dynamic Range technology was essential to accurately capture the data needed to calculate the luminance distribution because it allows to capture luminance ranges occurring in real scenarios. The measurement results were represented in accordance with established methods in the field of daylighting. Measurements showed that the accuracy of the luminance distribution measurement device ranged from 5% to 20% (worst case which was deemed acceptable for practical measurements and broad applications in the building realm. 14. Blue Ribbon Panel Report Science.gov (United States) An NCI Cancer Currents blog by the NCI acting director thanking the cancer community for contributing to the Cancer Moonshot Blue Ribbon Panel report, which was presented to the National Cancer Advisory Board on September 7. 15. Northeast Atlantic blue whiting OpenAIRE Heino, Mikko 2010-01-01 Heino, M. 2010. Northeast Atlantic blue whiting. In Life cycle spatial patterns of small pelagic fish in the Northeast Atlantic, pp. 59-64. Ed by P. Petitgas. ICES Cooperative Research Report 306. ICES, Copenhagen. 16. New York Blue Data.gov (United States) Federal Laboratory Consortium — New York Blue is used cooperatively by the Laboratory and Stony Brook University as part of the New York Center for Computation Sciences. Ranked as the 28th fastest... 17. Calibrating photometric redshifts of luminous red galaxies International Nuclear Information System (INIS) Padmanabhan, Nikhil; Budavari, Tamas; Schlegel, David J.; Bridges, Terry; Brinkmann, Jonathan 2005-01-01 We discuss the construction of a photometric redshift catalogue of luminous red galaxies (LRGs) from the Sloan Digital Sky Survey (SDSS), emphasizing the principal steps necessary for constructing such a catalogue: (i) photometrically selecting the sample, (ii) measuring photometric redshifts and their error distributions, and (iii) estimating the true redshift distribution. We compare two photometric redshift algorithms for these data and find that they give comparable results. Calibrating against the SDSS and SDSS–2dF (Two Degree Field) spectroscopic surveys, we find that the photometric redshift accuracy is σ~ 0.03 for redshifts less than 0.55 and worsens at higher redshift (~ 0.06 for z < 0.7). These errors are caused by photometric scatter, as well as systematic errors in the templates, filter curves and photometric zero-points. We also parametrize the photometric redshift error distribution with a sum of Gaussians and use this model to deconvolve the errors from the measured photometric redshift distribution to estimate the true redshift distribution. We pay special attention to the stability of this deconvolution, regularizing the method with a prior on the smoothness of the true redshift distribution. The methods that we develop are applicable to general photometric redshift surveys. 18. Statistical thermodynamics of supercapacitors and blue engines NARCIS (Netherlands) van Roij, R.H.H.G. 2013-01-01 We study the thermodynamics of electrode-electrolyte systems, for instance supercapacitors filled with an ionic liquid or blue-energy devices filled with river- or sea water. By a suitable mapping of thermodynamic variables, we identify a strong analogy with classical heat engines. We introduce 19. The Blue Compact Dwarf Galaxy IZw18 NARCIS (Netherlands) Musella, I.; Marconi, M.; Fiorentino, G.; Clementini, G.; Aloisi, A.; Annibali, F.; Contreras, R.; Saha, A.; Tosi, M.; van der Marel, R. P. 2012-01-01 We present the results obtained for the Blue compact galaxy IZw18 on the basis of ACS HST data obtained from our group. In particular, we discuss the stellar population and the variable stars content of this galaxy to get information about its star formation history and distance. 20. Confirming LBV Candidates Through Variability: A Photometric and Spectroscopic Monitoring Study Science.gov (United States) Stringfellow, Guy; Gvaramadze, Vasilii 2013-02-01 Luminous Blue Variable (LBV) stars represent an extremely rare class of luminous massive stars with high mass loss rates. The paucity ( 12) of confirmed Galactic LBV precludes determining a solid evolutionary connection between LBV and other intermediate (e.g. Ofpe/WN9, WNL) phases in the life of very massive stars. We've been conducting an optical/near-IR spectral survey of a large subset of central stars residing within newly discovered it Spitzer nebulae and have identified over two dozen new candidate LBVs (cLBVs) based on spectral similarity alone; confirming them as bona fide LBVs requires demonstrating 1-3 mag photometric and spectroscopic variability. This marks a significant advancement in the study of massive stars, far outweighing the return from many studies searching for LBVs and WRs the past several decades. Monitoring from semesters 2011B-2012A already has confirmed one new cLBV as a bona fide LBV. We propose to continue optical-IR photometric monitoring of these cLBVS with the 1.3m. Chiron, replacing the RC spectrograph on the 1.5m, now allows high-resolution optical spectroscopic monitoring of bright cLBVs, 11 of which are proposed herein. Spectra are important for understanding the physics driving photometric variability, properties of the wind, and allow analysis of line profiles. 1. Exploratory X-ray monitoring of luminous radio-quiet quasars at high redshift: Initial results Energy Technology Data Exchange (ETDEWEB) Shemmer, Ohad; Stein, Matthew S. [Department of Physics, University of North Texas, Denton, TX 76203 (United States); Brandt, W. N.; Schneider, Donald P. [Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States); Paolillo, Maurizio [Dipartimento di Scienze Fisiche, Università Federico II di Napoli, via Cinthia 6, I-80126 Napoli (Italy); Kaspi, Shai [School of Physics and Astronomy and the Wise Observatory, Tel Aviv University, Tel Aviv 69978 (Israel); Vignali, Cristian [Dipartimento di Astronomia, Università degli studi di Bologna, via Ranzani 1, I-40127 Bologna (Italy); Lira, Paulina [Departamento de Astronomia, Universidad de Chile, Camino del Observatorio 1515, Santiago (Chile); Gibson, Robert R., E-mail: ohad@unt.edu [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States) 2014-03-10 We present initial results from an exploratory X-ray monitoring project of two groups of comparably luminous radio-quiet quasars (RQQs). The first consists of four sources at 4.10 ≤ z ≤ 4.35, monitored by Chandra, and the second is a comparison sample of three sources at 1.33 ≤ z ≤ 2.74, monitored by Swift. Together with archival X-ray data, the total rest-frame temporal baseline spans ∼2-4 yr and ∼5-13 yr for the first and second group, respectively. Six of these sources show significant X-ray variability over rest-frame timescales of ∼10{sup 2}-10{sup 3} days; three of these also show significant X-ray variability on rest-frame timescales of ∼1-10 days. The X-ray variability properties of our variable sources are similar to those exhibited by nearby and far less luminous active galactic nuclei (AGNs). While we do not directly detect a trend of increasing X-ray variability with redshift, we do confirm previous reports of luminous AGNs exhibiting X-ray variability above that expected from their luminosities, based on simplistic extrapolation from lower luminosity sources. This result may be attributed to luminous sources at the highest redshifts having relatively high accretion rates. Complementary UV-optical monitoring of our sources shows that variations in their optical-X-ray spectral energy distribution are dominated by the X-ray variations. We confirm previous reports of X-ray spectral variations in one of our sources, HS 1700+6416, but do not detect such variations in any of our other sources in spite of X-ray flux variations of up to a factor of ∼4. This project is designed to provide a basic assessment of the X-ray variability properties of RQQs at the highest accessible redshifts that will serve as a benchmark for more systematic monitoring of such sources with future X-ray missions. 2. WARM MOLECULAR GAS IN LUMINOUS INFRARED GALAXIES Energy Technology Data Exchange (ETDEWEB) Lu, N.; Zhao, Y.; Xu, C. K.; Mazzarella, J. M.; Howell, J.; Appleton, P.; Lord, S.; Schulz, B. [Infrared Processing and Analysis Center, California Institute of Technology, MS 100-22, Pasadena, CA 91125 (United States); Gao, Y. [Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China); Armus, L.; Díaz-Santos, T.; Surace, J. [Spitzer Science Center, California Institute of Technology, MS 220-6, Pasadena, CA 91125 (United States); Isaak, K. G. [ESA Astrophysics Missions Division, ESTEC, P.O. Box 299, 2200-AG Noordwijk (Netherlands); Petric, A. O. [Gemini Observatory, 670 N. A' ohoku Place, Hilo, HI 96720 (United States); Charmandaris, V. [Department of Physics, University of Crete, GR-71003 Heraklion (Greece); Evans, A. S. [Department of Astronomy, University of Virginia, 530 McCormick Road, Charlottesville, VA 22904 (United States); Inami, H. [National Optical Astronomy Observatory, Tucson, AZ 85719 (United States); Iwasawa, K. [ICREA and Institut de Ciències del Cosmos (ICC), Universitat de Barcelona (IEEC-UB), Martí i Franquès 1, E-08028 Barcelona (Spain); Leech, J. [Department of Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH (United Kingdom); Sanders, D. B., E-mail: lu@ipac.caltech.edu [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); and others 2014-06-01 We present our initial results on the CO rotational spectral line energy distribution (SLED) of the J to J–1 transitions from J = 4 up to 13 from Herschel SPIRE spectroscopic observations of 65 luminous infrared galaxies (LIRGs) in the Great Observatories All-Sky LIRG Survey. The observed SLEDs change on average from one peaking at J ≤ 4 to a broad distribution peaking around J ∼ 6 to 7 as the IRAS 60-to-100 μm color, C(60/100), increases. However, the ratios of a CO line luminosity to the total infrared luminosity, L {sub IR}, show the smallest variation for J around 6 or 7. This suggests that, for most LIRGs, ongoing star formation (SF) is also responsible for a warm gas component that emits CO lines primarily in the mid-J regime (5 ≲ J ≲ 10). As a result, the logarithmic ratios of the CO line luminosity summed over CO (5–4), (6–5), (7–6), (8–7) and (10–9) transitions to L {sub IR}, log R {sub midCO}, remain largely independent of C(60/100), and show a mean value of –4.13 (≡log R{sub midCO}{sup SF}) and a sample standard deviation of only 0.10 for the SF-dominated galaxies. Including additional galaxies from the literature, we show, albeit with a small number of cases, the possibility that galaxies, which bear powerful interstellar shocks unrelated to the current SF, and galaxies, in which an energetic active galactic nucleus contributes significantly to the bolometric luminosity, have their R {sub midCO} higher and lower than R{sub midCO}{sup SF}, respectively. 3. Production of L-Asparaginase by the marine luminous bacteria Digital Repository Service at National Institute of Oceanography (India) Ramaiah, N.; Chandramohan, D. Fortythree strains of luminous bacteria, belonging to 4 species, (Vibrio harveyi, V. fischeri, Photobacterium leiognathi and P. phosphoreum) isolated from different marine samples, were examined for the production of L-asparaginase. Presence... 4. Study on the luminous characteristics of a natural ball lightning Science.gov (United States) Wang, Hao; Yuan, Ping; Cen, Jianyong; Liu, Guorong 2018-02-01 According to the optical images of the whole process of a natural ball lightning recorded by two slit-less spectrographs in the Qinghai plateau of China, the simulated observation experiment on the luminous intensity of the spherical light source was carried out. The luminous intensity and the optical power of the natural ball lightning in the wavelength range of 400-690 nm were estimated based on the experimental data and the Lambert-Beer Law. The results show that the maximum luminous intensity was about 1.24 × 105 cd in the initial stage of the natural ball lightning, and the maximum luminous intensity and the maximum optical power in most time of its life were about 5.9 × 104 cd and 4.2 × 103 W, respectively. 5. Geometry of illumination, luminance contrast, and gloss perception OpenAIRE Leloup, Frédéric; Pointer, Michael R.; Dutré, Philip; Hanselaer, Peter 2010-01-01 The influence of both the geometry of illumination and luminance contrast on gloss perception has been examined using the method of paired comparison. Six achromatic glass samples having different lightness were illuminated by two light sources. Only one of these light sources was visible in reflection by the observer. By separate adjustment of the intensity of both light sources, the luminance of both the reflected image and the adjacent off-specular surroundings could be individually varied... 6. Predicting daylight illuminance on inclined surfaces using sky luminance data Energy Technology Data Exchange (ETDEWEB) Li, D.H.W.; Lau, C.C.S.; Lam, J.C. [City University of Hong Kong, Kowloon (China). Dept. of Building and Construction 2005-07-01 Daylight illuminance, particularly on vertical surfaces, plays a major role in determining and evaluating the daylighting performance of a building. In many parts of the world, however, the basic daylight illuminance data for various vertical planes are not always readily available. The usual method to obtain diffuse illuminance on tilted planes would be based on inclined surface models using data from the horizontal measurements. Alternatively, the diffuse illuminance on a sloping plane can be computed by integrating the luminance distribution of the sky 'seen' by the plane. This paper presents an approach to estimate the vertical outdoor illuminance from sky luminance data and solar geometry. Sky luminance data recorded from January 1999 to December 2001 in Hong Kong and generated by two well-known sky luminance models (Kittler and Perez) were used to compute the outdoor illuminance for the four principal vertical planes (N, E, S and W). The performance of this approach was evaluated against data measured in the same period. Statistical analysis indicated that using sky luminance distributions to predict outdoor illuminance can give reasonably good agreement with measured data for all vertical surfaces. The findings provide an accurate alternative to determine the amount of daylight on vertical as well as other inclined surfaces when sky luminance data are available. (author) 7. Dynamics of backlight luminance for using smartphone in dark environment Science.gov (United States) Na, Nooree; Jang, Jiho; Suk, Hyeon-Jeong 2014-02-01 This study developed dynamic backlight luminance, which gradually changes as time passes for comfortable use of a smartphone display in a dark environment. The study was carried out in two stages. In the first stage, a user test was conducted to identify the optimal luminance by assessing the facial squint level, subjective glare evaluation, eye blink frequency and users' subjective preferences. Based on the results of the user test, the dynamics of backlight luminance was designed. It has two levels of luminance: the optimal level for initial viewing to avoid sudden glare or fatigue to users' eyes, and the optimal level for constant viewing, which is comfortable, but also bright enough for constant reading of the displayed material. The luminance for initial viewing starts from 10 cd/m2, and it gradually increases to 40 cd/m2 for users' visual comfort at constant viewing for 20 seconds; In the second stage, a validation test on dynamics of backlight luminance was conducted to verify the effectiveness of the developed dynamics. It involving users' subjective preferences, eye blink frequency, and brainwave analysis using the electroencephalogram (EEG) to confirm that the proposed dynamic backlighting enhances users' visual comfort and visual cognition, particularly for using smartphones in a dark environment. 8. Detection of chromatic and luminance distortions in natural scenes. Science.gov (United States) Jennings, Ben J; Wang, Karen; Menzies, Samantha; Kingdom, Frederick A A 2015-09-01 A number of studies have measured visual thresholds for detecting spatial distortions applied to images of natural scenes. In one study, Bex [J. Vis.10(2), 1 (2010)10.1167/10.2.231534-7362] measured sensitivity to sinusoidal spatial modulations of image scale. Here, we measure sensitivity to sinusoidal scale distortions applied to the chromatic, luminance, or both layers of natural scene images. We first established that sensitivity does not depend on whether the undistorted comparison image was of the same or of a different scene. Next, we found that, when the luminance but not chromatic layer was distorted, performance was the same regardless of whether the chromatic layer was present, absent, or phase-scrambled; in other words, the chromatic layer, in whatever form, did not affect sensitivity to the luminance layer distortion. However, when the chromatic layer was distorted, sensitivity was higher when the luminance layer was intact compared to when absent or phase-scrambled. These detection threshold results complement the appearance of periodic distortions of the image scale: when the luminance layer is distorted visibly, the scene appears distorted, but when the chromatic layer is distorted visibly, there is little apparent scene distortion. We conclude that (a) observers have a built-in sense of how a normal image of a natural scene should appear, and (b) the detection of distortion in, as well as the apparent distortion of, natural scene images is mediated predominantly by the luminance layer and not chromatic layer. 9. Tritium pollution in the Swiss luminous compound industry International Nuclear Information System (INIS) Krejci, K.; Zeller, Jr. 1979-01-01 The Swiss luminous compound industry is an important consumer of tritium. About 350kCi go into production of tritium gas-filled light sources and 40kCi into production of tritium luminous compound annually. To illustrate the pollution problem, a factory is mentioned that handles 200kCi annually and a chain of luminizers, processing 20kCi over the same period as tritium luminous compound. This material is manufactured by coating phosphors with tritiated polystyrene having a specific activity up to 200Ci/g. Because of the high specific activity, the radiation damage produces an average activity release of 5.2% annually, which is one of the main reasons for public and occupational exposure. The processing of large quantities of tritium gas requires special equipment, such as units made entirely of stainless steel for purification and hydrogenation, oxidation systems for highly contaminated air, glove boxes, ventilation and monitoring systems. Nevertheless, contamination of air, surfaces, water and workers cannot be avoided. Only in a few cases were MPC-values for tritium content in urine of workers exceeded. From these results, biological half-lives between 5-15 days were estimated. Regular medical examinations showed no significant influence in blood picture parameters, except in one single case with a tritium concentration in urine of 2.8mCi/litre. Entirely different problems arise in most luminizing factories where luminous paint is processed as an open radioactive source. (author) 10. HALESIS projet: Hight Altitude Luminous Events Studied by Infrared Spectro-imagery Science.gov (United States) Croizé, Laurence; Payan, Sébastien; Bureau, Jérome; Duruisseau, Fabrice; Huret, Nathalie 2014-05-01 During the last two decades, the discovery of transient luminous events (TLEs) in the high atmosphere [1], as well as the observation of gamma ray flashes of terrestrial origin (Terrestrial Gamma Flashes or TGF) [2] demonstrated the existence of another interaction processes between the different atmospheric layers (troposphere, stratosphere, mesosphere and ionosphere). Indeed, the frequency of occurrence of these phenomena over thunderstorm cells, and the energies involved provide evidence for an impulsive energy transfer between the troposphere and the highest atmospheric layers, which was not considered before. HALESIS (High Altitude Luminous Events Studied by Infrared Spectro-imagery) is an innovative project based on hyperspectral imagery. The purpose of this experience is to measure the atmospheric perturbation in the minutes following the occurrence of Transient Luminous Events (TLEs) from a stratospheric balloon in the altitude range of 20 to 40 km. The first part of the study has been dedicated to establish the project feasibility. To do that, we have simulated spectral perturbation induced by an isolated blue jet. Theoretical predictions [3] have been used to simulate the radiative perturbation due to O3, NO, NO2, NO+ concentration induced by the blue jet. Simulations have been performed using the line by line radiative transfer model LBLRM [4] taking into account of the Non Local Thermodynamic Equilibrium hypotheses. Then, the expected signatures have been compared to the available instrumentation. During this talk, HALESIS project and the results of the feasibility study will be presented. Then, the estimated spectral signatures will be confronted with the technical capabilities of different kind of hyperspectral imagers. We will conclude on the project feasibility, but also on the challenges that lie ahead for an imager perfectly suited for experiences like HALESIS. 1. Franz R, Nemzek R, Winckler J. Television image of a large upward electrical 11. Natural Blue Food Colour DEFF Research Database (Denmark) Roda-Serrat, Maria Cinta In recent years, there has been a growing tendency to avoid the use of artificial colorants and additives in food products, especially after some studies linked their consumption with behavioural changes in children. However, the incorporation of colorants from natural origin remains a challenge...... for food technologists, as these are typically less vivid and less stable than their synthetic alternatives. Regarding blue colorants, phycocyanins from cyanobacteria are currently in the spotlight as promising new natural blue colorants. Phycocyanins are proteins which blue colour results from...... the presence of the chromophore phycocyanobilin (PCB), a covalently attached linear tetrapyrrole. The applications of phycocyanins as food colorants are however limited, as they show poor stability in certain conditions of pH, light and temperature. Cleavage of PCB from the protein followed by careful product... 12. Advancing Our Understanding of the Etiologies and Mutational Landscapes of Basal Like, Luminal A, and Luminal B Breast Cancers Science.gov (United States) 2016-10-01 will be further analyzed for effects on reading frame and protein structure and function using analysis and prediction tools such as PolyPhen and...luminal A, and luminal B tumors. Originally this study intended to include 900 newly diagnosed first primary triple negative (TN) invasive breast cancer...breast cancer risk factors. At the end of the interview participants will be asked to donate an oral tissue specimen for future genetic testing. Medical 13. Optical spectroscopy of the blue supergiant Sk-69° 279 and its circumstellar shell with SALT Science.gov (United States) Gvaramadze, V. V.; Kniazev, A. Y.; Maryeva, O. V.; Berdnikov, L. N. 2018-02-01 We report the results of optical spectroscopy of the blue supergiant Sk-69° 279 and its circular shell in the Large Magellanic Cloud (LMC) with the Southern African Large Telescope (SALT). We classify Sk-69° 279 as an O9.2 Iaf star and analyse its spectrum by using the stellar atmosphere code CMFGEN, obtaining a stellar temperature of ≈30 kK, a luminosity of log (L*/ L⊙) = 5.54, a mass-loss rate of log (\\dot{M}/ M_{⊙} yr^{-1}) = -5.26, and a wind velocity of 800km s-1. We found also that Sk-69° 279 possesses an extended atmosphere with an effective temperature of ≈24 kK and that its surface helium and nitrogen abundances are enhanced, respectively, by factors of ≈2 and 20-30. This suggests that either Sk-69° 279 was initially a (single) fast-rotating ( ≳ 400 km s- 1) star, which only recently evolved off the main sequence, or that it is a product of close binary evolution. The long-slit spectroscopy of the shell around Sk-69° 279 revealed that its nitrogen abundance is enhanced by the same factor as the stellar atmosphere, which implies that the shell is composed mostly of the CNO processed material lost by the star. Our findings support previous propositions that some massive stars can produce compact circumstellar shells and, presumably, appear as luminous blue variables while they are still on the main sequence or have only recently left it. 14. Brightness, hue, and saturation in photopic vision: a result of luminance and wavelength in the cellular phase-grating optical 3D chip of the inverted retina Science.gov (United States) Lauinger, Norbert 1994-10-01 In photopic vision, two physical variables (luminance and wavelength) are transformed into three psychological variables (brightness, hue, and saturation). Following on from 3D grating optical explanations of aperture effects (Stiles-Crawford effects SCE I and II), all three variables can be explained via a single 3D chip effect. The 3D grating optical calculations are carried out using the classical von Laue equation and demonstrated using the example of two experimentally confirmed observations in human vision: saturation effects for monochromatic test lights between 485 and 510 nm in the SCE II and the fact that many test lights reverse their hue shift in the SCE II when changing from moderate to high luminances compared with that on changing from low to medium luminances. At the same time, information is obtained on the transition from the trichromatic color system in the retina to the opponent color system. 15. Hubble's View of Little Blue Dots Science.gov (United States) Kohler, Susanna 2018-02-01 The recent discovery of a new type of tiny, star-forming galaxy is the latest in a zoo of detections shedding light on our early universe. What can we learn from the unique little blue dots found in archival Hubble data?Peas, Berries, and DotsGreen pea galaxies identified by citizen scientists with Galaxy Zoo. [Richard Nowell Carolin Cardamone]As telescope capabilities improve and we develop increasingly deeper large-scale surveys of our universe, we continue to learn more about small, faraway galaxies. In recent years, increasing sensitivity first enabled the detection of green peas luminous, compact, low-mass (10 billion solar masses; compare this to the Milky Ways 1 trillion solar masses!) galaxies with high rates of star formation.Not long thereafter, we discovered galaxies that form stars similarly rapidly, but are even smaller only 330 million solar masses, spanning less than 3,000 light-years in size. These tiny powerhouses were termed blueberries for their distinctive color.Now, scientists Debra and Bruce Elmegreen (of Vassar College and IBM Research Division, respectively) report the discovery of galaxies that have even higher star formation rates and even lower masses: little blue dots.Exploring Tiny Star FactoriesThe Elmegreens discovered these unique galaxies by exploring archival Hubble data. The Hubble Frontier Fields data consist of deep images of six distant galaxy clusters and the parallel fields next to them. It was in the archival data for two Frontier Field Parallels, those for clusters Abell 2744 and MAS J0416.1-2403, that the authors noticed several galaxies that stand out as tiny, bright, blue objects that are nearly point sources.Top: a few examples of the little blue dots recently identified in two Hubble Frontier Field Parallels. Bottom: stacked images for three different groups of little blue dots. [Elmegreen Elmegreen 2017]The authors performed a search through the two Frontier Field Parallels, discovering a total of 55 little blue dots 16. The "Blue Banana" Revisited NARCIS (Netherlands) Faludi, A.K.F. 2015-01-01 This essay is about the “Blue Banana”. Banana is the name given subsequently by others to a Dorsale européenne (European backbone) identified empirically by Roger Brunet. In a background study to the Communication of the European Commission ‘Europe 2000’, Klaus Kunzmann and Michael Wegener put 17. Blue Light Emitting Polyphenylene Dendrimers with Bipolar Charge Transport Moieties Directory of Open Access Journals (Sweden) Guang Zhang 2016-10-01 Full Text Available Two light-emitting polyphenylene dendrimers with both hole and electron transporting moieties were synthesized and characterized. Both molecules exhibited pure blue emission solely from the pyrene core and efficient surface-to-core energy transfers when characterized in a nonpolar environment. In particular, the carbazole- and oxadiazole-functionalized dendrimer (D1 manifested a pure blue emission from the pyrene core without showing intramolecular charge transfer (ICT in environments with increasing polarity. On the other hand, the triphenylamine- and oxadiazole-functionalized one (D2 displayed notable ICT with dual emission from both the core and an ICT state in highly polar solvents. D1, in a three-layer organic light emitting diode (OLED by solution processing gave a pure blue emission with Commission Internationale de l’Éclairage 1931 CIE xy = (0.16, 0.12, a peak current efficiency of 0.21 cd/A and a peak luminance of 2700 cd/m2. This represents the first reported pure blue dendrimer emitter with bipolar charge transport and surface-to-core energy transfer in OLEDs. 18. Blue Light Emitting Polyphenylene Dendrimers with Bipolar Charge Transport Moieties. Science.gov (United States) Zhang, Guang; Auer-Berger, Manuel; Gehrig, Dominik W; Blom, Paul W M; Baumgarten, Martin; Schollmeyer, Dieter; List-Kratochvil, E J W; Müllen, Klaus 2016-10-20 Two light-emitting polyphenylene dendrimers with both hole and electron transporting moieties were synthesized and characterized. Both molecules exhibited pure blue emission solely from the pyrene core and efficient surface-to-core energy transfers when characterized in a nonpolar environment. In particular, the carbazole- and oxadiazole-functionalized dendrimer ( D1 ) manifested a pure blue emission from the pyrene core without showing intramolecular charge transfer (ICT) in environments with increasing polarity. On the other hand, the triphenylamine- and oxadiazole-functionalized one ( D2 ) displayed notable ICT with dual emission from both the core and an ICT state in highly polar solvents. D1 , in a three-layer organic light emitting diode (OLED) by solution processing gave a pure blue emission with Commission Internationale de l'Éclairage 1931 CIE xy = (0.16, 0.12), a peak current efficiency of 0.21 cd/A and a peak luminance of 2700 cd/m². This represents the first reported pure blue dendrimer emitter with bipolar charge transport and surface-to-core energy transfer in OLEDs. 19. The Formation of Primordial Luminous Objects International Nuclear Information System (INIS) Ripamonti, Emanuele; Kapteyn Astron. Inst., Groningen; Abel, Tom; KIPAC, Menlo Park 2005-01-01 leave the discussion of feedback to lecture notes by Ferrara and Salvaterra and by Madau and Haardt in this same book and focus only on the aspects of the formation of the first objects. The advent of cosmological numerical hydrodynamics in particular allow a fresh new look at these questions. Hence, these notes will touch on aspects of theoretical cosmology to chemistry, computer science, hydrodynamics and atomic physics. For further reading and more references on the subject we refer the reader to other relevant reviews such as Barkana and Loeb 2001, and more recently Ciardi and Ferrara 2004, Glover 2004 and Bromm and Larson 2004. In these notes, we try to give a brief introduction to only the most relevant aspects. We will start with a brief overview of the relevant cosmological concepts in section 2, followed by a discussion of the properties of primordial material (with particular emphasis to its cooling and its chemistry) in section 3. We will then review the technique and the results of numerical simulations in sections 4 and 5: the former will deal with detailed 3D simulations of the formation of gaseous clouds which are likely to transform into luminous objects, while the latter will examine results (mostly from 1D codes) about the modalities of such transformation. Finally, in section 6 we will critically discuss the results of the previous sections, examining their consequences and comparing them to our present knowledge of the universe 20. Closing the mind's eye: incoming luminance signals disrupt visual imagery. Directory of Open Access Journals (Sweden) Rachel Sherwood Full Text Available Mental imagery has been associated with many cognitive functions, both high and low-level. Despite recent scientific advances, the contextual and environmental conditions that most affect the mechanisms of visual imagery remain unclear. It has been previously shown that the greater the level of background luminance the weaker the effect of imagery on subsequent perception. However, in these experiments it was unclear whether the luminance was affecting imagery generation or storage of a memory trace. Here, we report that background luminance can attenuate both mental imagery generation and imagery storage during an unrelated cognitive task. However, imagery generation was more sensitive to the degree of luminance. In addition, we show that these findings were not due to differential dark adaptation. These results suggest that afferent visual signals can interfere with both the formation and priming-memory effects associated with visual imagery. It follows that background luminance may be a valuable tool for investigating imagery and its role in various cognitive and sensory processes. 1. Association of proteasomal activity with metastasis in luminal breast cancer Science.gov (United States) Shashova, E. E.; Fesik, E. A.; Doroshenko, A. V. 2017-09-01 Chimotrypsin-like (ChTL) and caspase-like (CL) proteasomal activities were investigated in different variants of the tumor progression of luminal breast cancer. Patients with primary luminal breast cancer (n = 123) in stage T1-3N0-2M0 who had not received neoadjuvant treatment were included in this study. Proteasome ChTL and CL activities were determined in the samples of tumor and adjacent tissues. The coefficients of chymotrypsin-like (kChTL) and caspase-like (kCL) proteasome activity were also calculated as the ratio of the corresponding activity in the tumor tissue to activity in the adjacent tissue. ChTL, CL, kChTL and kCL in the tissues of luminal A and B breast cancer with lymphogenic metastasis were compared, and their association with hematogenous metastasis was evaluated. On the one hand, CL activity of proteasomes increased in luminal A breast cancer with extensive lymphogenic metastasis (N2), on the other hand it decreased in the luminal B subtype of cancer. The ratio of proteasomal activity in the tumor and adjacent tissues plays a significant role in the hematogenic pathway of breast cancer progression and is associated with poor metastatic-free survival. 2. Impact of Intestinal Microbiota on Intestinal Luminal Metabolome Science.gov (United States) Matsumoto, Mitsuharu; Kibe, Ryoko; Ooga, Takushi; Aiba, Yuji; Kurihara, Shin; Sawaki, Emiko; Koga, Yasuhiro; Benno, Yoshimi 2012-01-01 Low–molecular-weight metabolites produced by intestinal microbiota play a direct role in health and disease. In this study, we analyzed the colonic luminal metabolome using capillary electrophoresis mass spectrometry with time-of-flight (CE-TOFMS) —a novel technique for analyzing and differentially displaying metabolic profiles— in order to clarify the metabolite profiles in the intestinal lumen. CE-TOFMS identified 179 metabolites from the colonic luminal metabolome and 48 metabolites were present in significantly higher concentrations and/or incidence in the germ-free (GF) mice than in the Ex-GF mice (p metabolome and a comprehensive understanding of intestinal luminal metabolome is critical for clarifying host-intestinal bacterial interactions. PMID:22724057 3. Luminal progenitors restrict their lineage potential during mammary gland development. Science.gov (United States) Rodilla, Veronica; Dasti, Alessandro; Huyghe, Mathilde; Lafkas, Daniel; Laurent, Cécile; Reyal, Fabien; Fre, Silvia 2015-02-01 The hierarchical relationships between stem cells and progenitors that guide mammary gland morphogenesis are still poorly defined. While multipotent basal stem cells have been found within the myoepithelial compartment, the in vivo lineage potential of luminal progenitors is unclear. Here we used the expression of the Notch1 receptor, previously implicated in mammary gland development and tumorigenesis, to elucidate the hierarchical organization of mammary stem/progenitor cells by lineage tracing. We found that Notch1 expression identifies multipotent stem cells in the embryonic mammary bud, which progressively restrict their lineage potential during mammary ductal morphogenesis to exclusively generate an ERαneg luminal lineage postnatally. Importantly, our results show that Notch1-labelled cells represent the alveolar progenitors that expand during pregnancy and survive multiple successive involutions. This study reveals that postnatal luminal epithelial cells derive from distinct self-sustained lineages that may represent the cells of origin of different breast cancer subtypes. 4. Asymmetric effects of luminance and chrominance in the watercolor illusion Directory of Open Access Journals (Sweden) Andrew eCoia 2014-09-01 Full Text Available When bounded by a line of sufficient contrast, the desaturated hue of a colored line will spread over an enclosed area, an effect known as the watercolor illusion. The contrast of the two lines can be in luminance, chromaticity, or a combination of both. The effect is most salient when the enclosing line has greater contrast with the background than the line that induces the spreading color. In most prior experiments with watercolor spreading, the luminance of both lines has been lower than the background. An achromatic version of the illusion exists where a dark line will spread while being bounded by either a darker or brighter line. In a previous study we measured the strength of the watercolor effect in which the colored inducing line was isoluminant to the background, and found an illusion for both brighter and darker achromatic outer contours. We also found the strength of spreading is stronger for bluish (+S cone input colors compared to yellowish (-S cone input ones, when bounded by a dark line. The current study set out to measure the hue dependence of the watercolor illusion when inducing colors are flanked with brighter (increment as opposed to darker outer lines. The asymmetry in the watercolor effect with S cone input was enhanced when the inducing contrast was an increment rather than a decrement. Further experiments explored the relationship between the perceived contrast of these chromatic lines when paired with luminance increments and decrements and revealed that the perceived contrast of luminance increments and decrements is dependent on which isoluminant color they are paired with. In addition to known hue asymmetries in the watercolor illusion there are asymmetries between luminance increments and decrements that are also hue dependent. These latter asymmetries may be related to the perceived contrast of the hue/luminance parings. 5. Asymmetric effects of luminance and chrominance in the watercolor illusion. Science.gov (United States) Coia, Andrew J; Crognale, Michael A 2014-01-01 When bounded by a line of sufficient contrast, the desaturated hue of a colored line will spread over an enclosed area, an effect known as the watercolor illusion. The contrast of the two lines can be in luminance, chromaticity, or a combination of both. The effect is most salient when the enclosing line has greater contrast with the background than the line that induces the spreading color. In most prior experiments with watercolor spreading, the luminance of both lines has been lower than the background. An achromatic version of the illusion exists where a dark line will spread while being bounded by either a darker or brighter line. In a previous study we measured the strength of the watercolor effect in which the colored inducing line was isoluminant to the background, and found an illusion for both brighter and darker achromatic outer contours. We also found the strength of spreading is stronger for bluish (+S cone input) colors compared to yellowish (-S cone input) ones, when bounded by a dark line. The current study set out to measure the hue dependence of the watercolor illusion when inducing colors are flanked with brighter (increment) as opposed to darker outer lines. The asymmetry in the watercolor effect with S cone input was enhanced when the inducing contrast was an increment rather than a decrement. Further experiments explored the relationship between the perceived contrast of these chromatic lines when paired with luminance increments and decrements and revealed that the perceived contrast of luminance increments and decrements is dependent on which isoluminant color they are paired with. In addition to known hue asymmetries in the watercolor illusion there are asymmetries between luminance increments and decrements that are also hue dependent. These latter asymmetries may be related to the perceived contrast of the hue/luminance parings. 6. Human Mammary Luminal Epithelial Cells Contain Progenitors to Myoepithelial Cells Energy Technology Data Exchange (ETDEWEB) Pechoux, Christine; Gudjonsson, Thorarinn; Ronnov-Jessen, Lone; Bissell, Mina J; Petersen, Ole 1999-02-01 The origin of the epithelial and myoepithelial cells in the human breast has not been delineated. In this study we have addressed whether luminal epithelial cells and myoepithelial cells are vertically connected, i.e., whether one is the precursor for the other. We used a primary culture assay allowing preservation of basic phenotypic traits of luminal epithelial and myoepithelial cells in culture. The two cell types were then separated immunomagnetically using antibodies directed against lineage-specific cell surface antigens into at best 100% purity. The cellular identity was ascertained by cytochemistry, immunoblotting, and 2-D gel electrophoresis. Luminal epithelial cells were identified by strong expression of cytokeratins 18 and 19 while myoepithelial cells were recognized by expression of vimentin and {alpha}-smooth muscle actin. We used a previously devised culture medium (CDM4) that allows vigorous expansion of proliferative myoepithelial cells and also devised a medium (CDM6) that allowed sufficient expansion of differentiated luminal epithelial cells based on addition of hepatocyte growth factor/scatter factor. The two different culture media supported each lineage for at least five passages without signs of interconversion. We used parallel cultures where we switched culture media, thus testing the ability of each lineage to convert to the other. Whereas the myoepithelial lineage showed no signs of interconversion, a subset of luminal epithelial cells, gradually, but distinctly, converted to myoepithelial cells. We propose that in the mature human breast, it is the luminal epithelial cell compartment that gives rise to myoepithelial cells rather than the other way around. 7. THE TRANSATLANTIC BLUE DIPLOMACY Directory of Open Access Journals (Sweden) Ioana GUTU 2016-12-01 Full Text Available The international diplomatic environment has reached to an unprecedented development, involving one of the newly specialized diplomatic types, namely the economic diplomacy. At the core of the fast movements in the diplomatic spheres across the Globe are the international agreements like the Transatlantic Trade and Investment Partnership (TTIP that determined diplomacy to dissolve into new subtypes, evolving from ground to the ocean and implementing new ways of achieving economic and climate sustainability. One of the newly created diplomatic spheres, is the blue ocean diplomacy that acts mainly in accordance with the rules and regulations that are being applied to the transatlantic economy. Even though TTIP encourages the increase of trade flows across the Atlantic, it will also ease the foreign investment procedures that, under the approach of keeping a sustainable environment, will represent one of the most important initiatives in implementing the blue economy concept within the framework of the transatlantic diplomacy. 8. Effect of Ionizing Radiation on Luminous Bacteria Cells International Nuclear Information System (INIS) Kudryasheva, N.; Rozhko, T.; Alexandrova, M.; Vasyunkina, E.; Arkhipova, V. 2011-01-01 Marine luminous bacteria were used to monitor toxicity of alpha- (Am-241, U-235+238) and beta- (tritium) radionuclide solutions. Increase or inhibition of bacterial luminescence was observed under exposure to radionuclides. Radiation toxicity of Am and chemical toxicity of U were demonstrated. Effects of U were similar to those of stable heavy metals: sensitivity was about 10-5 M. Sensitivity of the bacteria to Am-241 was 300 Bq/L (10 -11 M). Inhibition of bacterial growth was observed under exposure to Am-241 and tritium. Role of peroxides and electron transfer processes in the effects of radionuclides on luminous bacteria is discussed. 9. A Blind Pilot: Who is a Super-Luminal Observer? Directory of Open Access Journals (Sweden) Rabounski D. 2008-04-01 Full Text Available This paper discusses the nature of a hypothetical super-luminal observer who, as well as a real (sub-light speed observer, perceives the world by light waves. This consideration is due to that fact that the theory of relativity permits different frames of reference, including light-like and super-luminal reference frames. In analogy with a blind pilot on board a supersonic jet aeroplane (or missile, perceived by blind people, it is concluded that the light barrier is observed in the framework of only the light signal exchange experiment. 10. Statistical thermodynamics of supercapacitors and blue engines OpenAIRE van Roij, René 2012-01-01 We study the thermodynamics of electrode-electrolyte systems, for instance supercapacitors filled with an ionic liquid or blue-energy devices filled with river- or sea water. By a suitable mapping of thermodynamic variables, we identify a strong analogy with classical heat engines. We introduce several Legendre transformations and Maxwell relations. We argue that one should distinguish between the differential capacity at constant ion number and at constant ion chemical potential, and derive ... 11. Discovery of a very Lyman-α-luminous quasar at z = 6.62. Science.gov (United States) Koptelova, Ekaterina; Hwang, Chorng-Yuan; Yu, Po-Chieh; Chen, Wen-Ping; Guo, Jhen-Kuei 2017-02-02 Distant luminous quasars provide important information on the growth of the first supermassive black holes, their host galaxies and the epoch of reionization. The identification of quasars is usually performed through detection of their Lyman-α line redshifted to 0.9 microns at z > 6.5. Here, we report the discovery of a very Lyman-α luminous quasar, PSO J006.1240 + 39.2219 at redshift z = 6.618, selected based on its red colour and multi-epoch detection of the Lyman-α emission in a single near-infrared band. The Lyman-α line luminosity of PSO J006.1240 + 39.2219 is unusually high and estimated to be 0.8 × 10 12 Solar luminosities (about 3% of the total quasar luminosity). The Lyman-α emission of PSO J006.1240 + 39.2219 shows fast variability on timescales of days in the quasar rest frame, which has never been detected in any of the known high-redshift quasars. The high luminosity of the Lyman-α line, its narrow width and fast variability resemble properties of local Narrow-Line Seyfert 1 galaxies which suggests that the quasar is likely at the active phase of the black hole growth accreting close or even beyond the Eddington limit. 12. Modeling blue stragglers in young clusters International Nuclear Information System (INIS) Lu Pin; Deng Licai; Zhang Xiaobin 2011-01-01 A grid of binary evolution models are calculated for the study of a blue straggler (BS) population in intermediate age (log Age = 7.85–8.95) star clusters. The BS formation via mass transfer and merging is studied systematically using our models. Both Case A and B close binary evolutionary tracks are calculated for a large range of parameters. The results show that BSs formed via Case B are generally bluer and even more luminous than those produced by Case A. Furthermore, the larger range in orbital separations of Case B models provides a probability of producing more BSs than in Case A. Based on the grid of models, several Monte-Carlo simulations of BS populations in the clusters in the age range are carried out. The results show that BSs formed via different channels populate different areas in the color magnitude diagram (CMD). The locations of BSs in CMD for a number of clusters are compared to our simulations as well. In order to investigate the influence of mass transfer efficiency in the models and simulations, a set of models is also calculated by implementing a constant mass transfer efficiency, β = 0.5, during Roche lobe overflow (Case A binary evolution excluded). The result shows BSs can be formed via mass transfer at any given age in both cases. However, the distributions of the BS populations on CMD are different. 13. THE UNUSUALLY LUMINOUS EXTRAGALACTIC NOVA SN 2010U International Nuclear Information System (INIS) Czekala, Ian; Berger, E.; Chornock, R.; Marion, G. H.; Margutti, R.; Challis, P.; Pastorello, A.; Botticella, M. T.; Ergon, M.; Sollerman, J.; Smartt, S.; Vinkó, J.; Wheeler, J. C. 2013-01-01 We present observations of the unusual optical transient SN 2010U, including spectra taken 1.03 days to 15.3 days after maximum light that identify it as a fast and luminous Fe II type nova. Our multi-band light curve traces the fast decline (t 2 = 3.5 ± 0.3 days) from maximum light (M V = –10.2 ± 0.1 mag), placing SN 2010U in the top 0.5% of the most luminous novae ever observed. We find typical ejecta velocities of ≈1100 km s –1 and that SN 2010U shares many spectral and photometric characteristics with two other fast and luminous Fe II type novae, including Nova LMC 1991 and M31N-2007-11d. For the extreme luminosity of this nova, the maximum magnitude versus rate of decline relationship indicates a massive white dwarf (WD) progenitor with a low pre-outburst accretion rate. However, this prediction is in conflict with emerging theories of nova populations, which predict that luminous novae from massive WDs should preferentially exhibit an alternate spectral type (He/N) near maximum light. 14. Profile of a Growing Urban School: The Lumin Experience Science.gov (United States) Ford, Terry 2015-01-01 This fairytale-come-true began with an idealistic public school teacher just out of college who lived in the neighborhood of her students. In stages, working with a community organizing group consisting mainly of concerned parents, Terry Ford founded what is now called Lumin Education, a network of campuses serving more than six hundred children… 15. SN 2010U: A LUMINOUS NOVA IN NGC 4214 International Nuclear Information System (INIS) Humphreys, Roberta M.; Helton, L. Andrew; Prieto, Jose L.; Rosenfield, Philip; Williams, Benjamin; Murphy, Jeremiah; Dalcanton, Julianne; Gilbert, Karoline; Kochanek, Christopher S.; Stanek, K. Z.; Khan, Rubab; Szczygiel, Dorota; Mogren, Karen; Fesen, Robert A.; Milisavljevic, Dan 2010-01-01 The luminosity, light curve, post-maximum spectrum, and lack of a progenitor on deep pre-outburst images suggest that SN 2010U was a luminous, fast nova. Its outburst magnitude is consistent with that for a fast nova using the maximum magnitude-rate of decline relationship for classical novae. 16. Might dark matter not be concentric with luminous matter International Nuclear Information System (INIS) Xu Chongming; Lu Tan. 1986-12-01 In this paper, an idea on dark matter nonconcentric with luminous matter is proposed. This case could influence the rotation curve of galaxy differently in its different direction. Recently, Rubin and Ford's observation on rotation curve of Hickson 88a has been explained by means of the idea. Some possible observational predictions have also been given. (author) 17. Luminance compensation for AMOLED displays using integrated MIS sensors Science.gov (United States) Vygranenko, Yuri; Fernandes, Miguel; Louro, Paula; Vieira, Manuela 2017-05-01 Active-matrix organic light-emitting diodes (AMOLEDs) are ideal for future TV applications due to their ability to faithfully reproduce real images. However, pixel luminance can be affected by instability of driver TFTs and aging effect in OLEDs. This paper reports on a pixel driver utilizing a metal-insulator-semiconductor (MIS) sensor for luminance control of the OLED element. In the proposed pixel architecture for bottom-emission AMOLEDs, the embedded MIS sensor shares the same layer stack with back-channel etched a Si:H TFTs to maintain the fabrication simplicity. The pixel design for a large-area HD display is presented. The external electronics performs image processing to modify incoming video using correction parameters for each pixel in the backplane, and also sensor data processing to update the correction parameters. The luminance adjusting algorithm is based on realistic models for pixel circuit elements to predict the relation between the programming voltage and OLED luminance. SPICE modeling of the sensing part of the backplane is performed to demonstrate its feasibility. Details on the pixel circuit functionality including the sensing and programming operations are also discussed. 18. Mechanical feedback in the molecular ISM of luminous IR galaxies NARCIS (Netherlands) Loenen, A. F.; Spaans, M.; Baan, W. A.; Meijerink, R. Aims. Molecular emission lines originating in the nuclei of luminous infra-red galaxies are used to determine the physical properties of the nuclear ISM in these systems. Methods. A large observational database of molecular emission lines is compared with model predictions that include heating by UV 19. Astronomy. ASASSN-15lh: A highly super-luminous supernova. Science.gov (United States) Dong, Subo; Shappee, B J; Prieto, J L; Jha, S W; Stanek, K Z; Holoien, T W-S; Kochanek, C S; Thompson, T A; Morrell, N; Thompson, I B; Basu, U; Beacom, J F; Bersier, D; Brimacombe, J; Brown, J S; Bufano, F; Chen, Ping; Conseil, E; Danilet, A B; Falco, E; Grupe, D; Kiyota, S; Masi, G; Nicholls, B; Olivares E, F; Pignata, G; Pojmanski, G; Simonian, G V; Szczygiel, D M; Woźniak, P R 2016-01-15 We report the discovery of ASASSN-15lh (SN 2015L), which we interpret as the most luminous supernova yet found. At redshift z = 0.2326, ASASSN-15lh reached an absolute magnitude of Mu ,AB = -23.5 ± 0.1 and bolometric luminosity Lbol = (2.2 ± 0.2) × 10(45) ergs s(-1), which is more than twice as luminous as any previously known supernova. It has several major features characteristic of the hydrogen-poor super-luminous supernovae (SLSNe-I), whose energy sources and progenitors are currently poorly understood. In contrast to most previously known SLSNe-I that reside in star-forming dwarf galaxies, ASASSN-15lh appears to be hosted by a luminous galaxy (MK ≈ -25.5) with little star formation. In the 4 months since first detection, ASASSN-15lh radiated (1.1 ± 0.2) × 10(52) ergs, challenging the magnetar model for its engine. Copyright © 2016, American Association for the Advancement of Science. 20. Gastric luminal epidermal growth factor is affected by diet | Iputo ... African Journals Online (AJOL) Objective. Diet is an area of major interest to those investigating the causes of cancer of the oesophagus in the Transkei. This study looked at the associations between intragastric epidermal growth factor level, diet and intragastric pH. Setting and subjects. A dietary survey was co-ordinated with studies of gastric luminal ... 1. Vocal Fold Epithelial Response to Luminal Osmotic Perturbation Science.gov (United States) Sivasankar, Mahalakshmi; Fisher, Kimberly V. 2007-01-01 Purpose: Dry-air challenges increase the osmolarity of fluid lining the luminal surface of the proximal airway. The homeostasis of surface fluid is thought to be essential for voice production and laryngeal defense. Therefore, the authors hypothesized that viable vocal fold epithelium would generate a water flux to reduce an osmotic challenge (150… 2. The predetermination of the luminance in tunnel entrances at day. NARCIS (Netherlands) Schreuder, D.A. & Oud, H.J.C. 1988-01-01 In tunnel lighting practice, only the scatter in the eye, in the windscreen of the car, and in the atmosphere need to be taken into account. For all practical day- time conditions, the required luminance in any portion of the tunnel can be assessed as being a constant fraction of this sum- 3. Relationship between luminous fish and symbiosis. I. Comparative studies of lipopolysaccharides isolated from symbiotic luminous bacteria of the luminous marine fish, Physiculus japonicus. Science.gov (United States) Kuwae, T; Andoh, M; Fukasawa, S; Kurata, M 1983-01-01 In order to investigate the relationship between host and symbiosis in the luminous marine fish, Physiculus japonicus, the bacterial lipopolysaccharides (LPS) of symbiotic luminous bacteria were compared serologically and electrophoretically. Five symbiotic luminous bacteria (PJ strains) were separately isolated from five individuals of this fish species caught at three points, off the coasts of Chiba, Nakaminato, and Oharai. LPS preparations were made from these bacteria by Westphal's phenol-water method and highly purified by repeated ultracentrifugation. These LPSs contained little or no 2-keto-3-deoxyoctonate and had powerful mitogenic activity. In sodium dodecylsulfate polyacrylamide gel electrophoresis, these PJ-1 to -5 LPSs were separated by their electrophoretic patterns into three groups; the first group included PJ-1 and PJ-4, the second group PJ-2 and PJ-3, and the third group PJ-5 alone. The results agreed with those of the double immunodiffusion test; precipitin lines completely coalesced within each group but not with other groups. In immunoelectrophoresis, one precipitin line was observed between anti PJ-2 LPS serum and PJ-5 LPS but the electrophoretic mobility of PJ-5 LPS was clearly different from that of the PJ-2 LPS group. Furthermore, in a 50% inhibition test with PJ-2 LPS by the passive hemolysis system, the doses of PJ-2 LPS, PJ-3 LPS, and PJ-5 LPS required for 50% inhibition (ID50) in this system were 0.25, 0.25, and 21.6 micrograms/ml for each alkali-treated LPS, respectively, and the ID50's of both PJ-1 LPS and PJ-4 LPS were above 1,000 micrograms/ml. These results indicate that PJ-5 LPS has an antigenic determinant partially in common with LPS from the PJ-2 group but not with LPS from the PJ-1 group and that the symbiotic luminous bacterium PJ-5 is more closely related to the PJ-2 group than to the PJ-1 group. These results show that the species Physiculus japonicus is symbiotically associated with at least three immunologically different 4. Anomalous Cepheids and population II blue stragglers Science.gov (United States) Nemec, James M. Recent studies of anomalous Cepheids (ACs) and population II blue stragglers (BSs), including photometrically variable BSs (VBSs), are reviewed. The VBSs represent about 25 percent of the BSs, the majority of which are SX Phe short-period variables in the Cepheid instability strip. Mass estimates derived using various techniques suggest that both ACs and BSs are relatively massive (about 1.0-1.6 solar mass). The recent discovery that two BSs in the globular cluster NGC 5466 are contact binaries, and the earlier discovery that one of the BSs in Omega Cen is an eclipsing binary, provide direct evidence that at least some BSs are binary systems. 5. The Blue Marble Science.gov (United States) 2002-01-01 This spectacular Moderate Resolution Imaging Spectroradiometer (MODIS) 'blue marble' image is based on the most detailed collection of true-color imagery of the entire Earth to date. Using a collection of satellite-based observations, scientists and visualizers stitched together months of observations of the land surface, oceans, sea ice, and clouds into a seamless, true-color mosaic of every square kilometer (.386 square mile) of our planet. Most of the information contained in this image came from MODIS, illustrating MODIS' outstanding capacity to act as an integrated tool for observing a variety of terrestrial, oceanic, and atmospheric features of the Earth. The land and coastal ocean portions of this image is based on surface observations collected from June through September 2001 and combined, or composited, every eight days to compensate for clouds that might block the satellite's view on any single day. Global ocean color (or chlorophyll) data was used to simulate the ocean surface. MODIS doesn't measure 3-D features of the Earth, so the surface observations were draped over topographic data provided by the U.S. Geological Survey EROS Data Center. MODIS observations of polar sea ice were combined with observations of Antarctica made by the National Oceanic and Atmospheric Administration's AVHRR sensor-the Advanced Very High Resolution Radiometer. The cloud image is a composite of two days of MODIS imagery collected in visible light wavelengths and a third day of thermal infra-red imagery over the poles. A large collection of imagery based on the blue marble in a variety of sizes and formats, including animations and the full (1 km) resolution imagery, is available at the Blue Marble page. Image by Reto Stockli, Render by Robert Simmon. Based on data from the MODIS Science Team 6. Astronomy in Denver: The polarization evolution of the luminous Type Ib SN 2012au Science.gov (United States) Hoffman, Jennifer L.; DeKlotz, Sophia; Cooper, Kevin; Slay, Hannah; Williams, George Grant; Supernova Spectropolarimetry Project (SNSPOL) 2018-06-01 We present an analysis of the spectropolarimetric behavior of the Type Ib SN 2012au over the first 315 days of its evolution. Our data were obtained by the Supernova Spectropolarimetry Project using the CCD Imaging/Spectropolarimeter (SPOL) at the 61" Kuiper, the 90" Bok, and the 6.5-m MMT telescopes. SN 2012au was a very energetic, luminous, and slowly evolving event that may represent an intermediate case between normal core-collapse supernovae and the enigmatic superluminous supernovae. Strong, time-variable line polarization signatures, particularly in the He Il λ5876 line, support previous hypotheses of an asymmetric explosion and allow us to trace detailed structures within the supernova ejecta as they change over time. We compare the polarimetric evolution of the continuum and emission lines in SN 2012au and compare its behavior with that of other bright and polarimetrically variable supernovae. 7. Effects of Irradiation on bacterial atp luminous intensity of cooled pork and chicken International Nuclear Information System (INIS) Ju Hua 2010-01-01 The effect of irradiation on cooled pork and chicken was detected with ATP luminous intensity method. The influences of other factors to ATP luminous intensity were also discussed. There was positive correlation between ATP standard concentration and ATP luminous intensity, and negative correlation between irradiation dosage and ATP luminous intensity. The trend of ATP luminous intensity of cooled pork and chicken after irradiation was inverse S, and the maximum ATP luminous intensity appeared at 6.0 kGy, and minimum at 4.0 and 8.0 kGy. Sterilized water and sterilized pork had no interference to ATP luminous intensity of the samples. There was significant positive correlation between E. coli 10003 concentration and ATP luminous intensity, the coefficient correlation was 0.9437. (authors) 8. Highly efficient deep-blue organic light emitting diode with a carbazole based fluorescent emitter Science.gov (United States) Sahoo, Snehasis; Dubey, Deepak Kumar; Singh, Meenu; Joseph, Vellaichamy; Thomas, K. R. Justin; Jou, Jwo-Huei 2018-04-01 High efficiency deep-blue emission is essential to realize energy-saving, high-quality display and lighting applications. We demonstrate here a deep-blue organic light emitting diode using a novel carbazole based fluorescent emitter 7-[4-(diphenylamino)phenyl]-9-(2-ethylhexyl)-9H-carbazole-2-carbonitrile (JV234). The solution processed resultant device shows a maximum luminance above 1,750 cd m-2 and CIE coordinates (0.15,0.06) with a 1.3 lm W-1 power efficiency, 2.0 cd A-1 current efficiency, and 4.1% external quantum efficiency at 100 cd m-2. The resulting deep-blue emission enables a greater than 100% color saturation. The high efficiency may be attributed to the effective host-to-guest energy transfer, suitable device architecture facilitating balanced carrier injection and low doping concentration preventing efficiency roll-off caused by concentration quenching. 9. Blue ocean leadership. Science.gov (United States) Kim, W Chan; Mauborgne, Renée 2014-05-01 Ten years ago, two INSEAD professors broke ground by introducing "blue ocean strategy," a new model for discovering uncontested markets that are ripe for growth. In this article, they apply their concepts and tools to what is perhaps the greatest challenge of leadership: closing the gulf between the potential and the realized talent and energy of employees. Research indicates that this gulf is vast: According to Gallup, 70% of workers are disengaged from their jobs. If companies could find a way to convert them into engaged employees, the results could be transformative. The trouble is, managers lack a clear understanding of what changes they could make to bring out the best in everyone. Here, Kim and Mauborgne offer a solution to that problem: a systematic approach to uncovering, at each level of the organization, which leadership acts and activities will inspire employees to give their all, and a process for getting managers throughout the company to start doing them. Blue ocean leadership works because the managers' "customers"-that is, the people managers oversee and report to-are involved in identifying what's effective and what isn't. Moreover, the approach doesn't require leaders to alter who they are, just to undertake a different set of tasks. And that kind of change is much easier to implement and track than changes to values and mind-sets. 10. The nature of luminous Ly α emitters at z ˜ 2-3: maximal dust-poor starbursts and highly ionizing AGN Science.gov (United States) Sobral, David; Matthee, Jorryt; Darvish, Behnam; Smail, Ian; Best, Philip N.; Alegre, Lara; Röttgering, Huub; Mobasher, Bahram; Paulino-Afonso, Ana; Stroe, Andra; Oteo, Iván 2018-06-01 Deep narrow-band surveys have revealed a large population of faint Ly α emitters (LAEs) in the distant Universe, but relatively little is known about the most luminous sources ({L}_{Lyα } ≳ 10^{42.7} erg s-1; L_{Lyα }≳ L^*_{Lyα }). Here we present the spectroscopic follow-up of 21 luminous LAEs at z ˜ 2-3 found with panoramic narrow-band surveys over five independent extragalactic fields (≈4 × 106 Mpc3 surveyed at z ˜ 2.2 and z ˜ 3.1). We use WHT/ISIS, Keck/DEIMOS, and VLT/X-SHOOTER to study these sources using high ionization UV lines. Luminous LAEs at z ˜ 2-3 have blue UV slopes (β =-2.0^{+0.3}_{-0.1}) and high Ly α escape fractions (50^{+20}_{-15} per cent) and span five orders of magnitude in UV luminosity (MUV ≈ -19 to -24). Many (70 per cent) show at least one high ionization rest-frame UV line such as C IV, N V, C III], He II or O III], typically blue-shifted by ≈100-200 km s-1 relative to Ly α. Their Ly α profiles reveal a wide variety of shapes, including significant blue-shifted components and widths from 200 to 4000 km s-1. Overall, 60 ± 11 per cent appear to be active galactic nucleus (AGN) dominated, and at LLyα > 1043.3 erg s-1 and/or MUV sharp transition in the nature of LAEs, from star formation dominated to AGN dominated. 11. File list: His.Brs.10.AllAg.Luminal_cells [Chip-atlas[Archive Lifescience Database Archive (English) Full Text Available His.Brs.10.AllAg.Luminal_cells mm9 Histone Breast Luminal cells SRX213395,SRX213418...,SRX213416 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.Brs.10.AllAg.Luminal_cells.bed ... 12. File list: ALL.Brs.10.AllAg.Luminal_cells [Chip-atlas[Archive Lifescience Database Archive (English) Full Text Available ALL.Brs.10.AllAg.Luminal_cells mm9 All antigens Breast Luminal cells SRX213395,SRX2...13418,SRX213398,SRX213416 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/ALL.Brs.10.AllAg.Luminal_cells.bed ... 13. File list: ALL.Brs.50.AllAg.Luminal_cells [Chip-atlas[Archive Lifescience Database Archive (English) Full Text Available ALL.Brs.50.AllAg.Luminal_cells mm9 All antigens Breast Luminal cells SRX213395,SRX2...13418,SRX213398,SRX213416 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/ALL.Brs.50.AllAg.Luminal_cells.bed ... 14. File list: His.Brs.05.AllAg.Luminal_cells [Chip-atlas[Archive Lifescience Database Archive (English) Full Text Available His.Brs.05.AllAg.Luminal_cells mm9 Histone Breast Luminal cells SRX213395,SRX213418...,SRX213416 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.Brs.05.AllAg.Luminal_cells.bed ... 15. File list: His.Brs.50.AllAg.Luminal_cells [Chip-atlas[Archive Lifescience Database Archive (English) Full Text Available His.Brs.50.AllAg.Luminal_cells mm9 Histone Breast Luminal cells SRX213395,SRX213418...,SRX213416 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.Brs.50.AllAg.Luminal_cells.bed ... 16. File list: ALL.Brs.20.AllAg.Luminal_cells [Chip-atlas[Archive Lifescience Database Archive (English) Full Text Available ALL.Brs.20.AllAg.Luminal_cells mm9 All antigens Breast Luminal cells SRX213395,SRX2...13418,SRX213398,SRX213416 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/ALL.Brs.20.AllAg.Luminal_cells.bed ... 17. Radiation exposure to dial painters from 3H luminous paint industry International Nuclear Information System (INIS) Sawant, J.V. 1992-01-01 Tritium is used as the active component in self-luminous paint. The paper describes in-vitro solubilisation study of luminous paint in blood serum. Besides urine samples of luminous paint workers and air samples of two watch factories were analysed for 3 H. The results of these analysis are also presented. (author). 8 refs., 4 figs., 4 tabs 18. Conjunctions of colour, luminance and orientation: the role of colour and luminance contrast on saliency and proximity grouping in texture segregation. Science.gov (United States) Leonards, U; Singer, W 2000-01-01 To examine whether perceptual grouping on the basis of orientation can be performed simultaneously with or only subsequently to grouping according to colour or luminance, we tested whether subjects are able to segregate arrays of texture elements that differ from surrounding elements by conjunctions of either (i) colour and orientation, or (ii) luminance contrast and orientation, or (iii) luminance contrast polarity and orientation. Subjects were able to use conjunctions between luminance and orientation for segregation but not conjunctions between colour or contrast polarity and orientation. Our results suggest that (i) in agreement with earlier findings, there seem to exist no specific conjunction detectors for colour and orientation or contrast polarity and orientation, and (ii) when orientation defined textures are to be distinguished by virtue of differences in luminance, colour, or contrast polarity, luminance provides a much stronger cue than colour or contrast polarity for saliency-based orientation grouping. 19. Synthesis and electroluminescent properties of blue emitting materials based on arylamine-substituted diphenylvinylbiphenyl derivatives for organic light-emitting diodes Energy Technology Data Exchange (ETDEWEB) Lee, Kum Hee; You, Jae Nam; Won, Jiyeon; Lee, Jin Yong [Department of Chemistry, Sungkyunkwan University, Suwon, 440-746 (Korea, Republic of); Seo, Ji Hoon [Department of Information Display, Hongik University, Seoul, 121-791 (Korea, Republic of); Kim, Young Kwan, E-mail: kimyk@hongik.ac.kr [Department of Information Display, Hongik University, Seoul, 121-791 (Korea, Republic of); Yoon, Seung Soo, E-mail: ssyoon@skku.edu [Department of Chemistry, Sungkyunkwan University, Suwon, 440-746 (Korea, Republic of) 2011-10-31 This paper reports the synthesis and electroluminescent properties of a series of blue emitting materials with arylamine and diphenylvinylbiphenyl groups for applications to efficient blue organic light-emitting diodes (OLEDs). All devices exhibited blue electroluminescence with electroluminescent properties that were quite sensitive to the structural features of the dopants in the emitting layers. In particular, the device using dopant 4 exhibited sky-blue emission with a maximum luminance, luminance efficiency, power efficiency, external quantum efficiency and CIE coordinates of 39,000 cd/m{sup 2}, 12.3 cd/A, 7.45 lm/W, 7.71% at 20 mA/cm{sup 2} and (x = 0.17, y = 0.31) at 8 V, respectively. In addition, a blue OLED using dopant 2 with CIE coordinates (x = 0.16, y = 0.18) at 8 V exhibited a luminous efficiency, power efficiency and external quantum efficiency of 4.39 cd/A, 2.46 lm/W and 2.97% at 20 mA/cm{sup 2}, respectively. 20. Tunable photonic crystals with partial bandgaps from blue phase colloidal crystals and dielectric-doped blue phases. Science.gov (United States) Stimulak, Mitja; Ravnik, Miha 2014-09-07 Blue phase colloidal crystals and dielectric nanoparticle/polymer doped blue phases are demonstrated to combine multiple components with different symmetries in one photonic material, creating a photonic crystal with variable and micro-controllable photonic band structure. In this composite photonic material, one contribution to the band structure is determined by the 3D periodic birefringent orientational profile of the blue phases, whereas the second contribution emerges from the regular array of the colloidal particles or from the dielectric/nanoparticle-doped defect network. Using the planewave expansion method, optical photonic bands of the blue phase I and II colloidal crystals and related nanoparticle/polymer doped blue phases are calculated, and then compared to blue phases with no particles and to face-centred-cubic and body-centred-cubic colloidal crystals in isotropic background. We find opening of local band gaps at particular points of Brillouin zone for blue phase colloidal crystals, where there were none in blue phases without particles or dopants. Particle size and filling fraction of the blue phase defect network are demonstrated as parameters that can directly tune the optical bands and local band gaps. In the blue phase I colloidal crystal with an additionally doped defect network, interestingly, we find an indirect total band gap (with the exception of one point) at the entire edge of SC irreducible zone. Finally, this work demonstrates the role of combining multiple - by symmetry - differently organised components in one photonic crystal material, which offers a novel approach towards tunable soft matter photonic materials. 1. Numerosity estimation in visual stimuli in the absence of luminance-based cues. Directory of Open Access Journals (Sweden) Peter Kramer 2011-02-01 Full Text Available Numerosity estimation is a basic preverbal ability that humans share with many animal species and that is believed to be foundational of numeracy skills. It is notoriously difficult, however, to establish whether numerosity estimation is based on numerosity itself, or on one or more non-numerical cues like-in visual stimuli-spatial extent and density. Frequently, different non-numerical cues are held constant on different trials. This strategy, however, still allows numerosity estimation to be based on a combination of non-numerical cues rather than on any particular one by itself.Here we introduce a novel method, based on second-order (contrast-based visual motion, to create stimuli that exclude all first-order (luminance-based cues to numerosity. We show that numerosities can be estimated almost as well in second-order motion as in first-order motion.The results show that numerosity estimation need not be based on first-order spatial filtering, first-order density perception, or any other processing of luminance-based cues to numerosity. Our method can be used as an effective tool to control non-numerical variables in studies of numerosity estimation. 2. High prevalence of luminal B breast cancer intrinsic subtype in Colombian women. Science.gov (United States) Serrano-Gomez, Silvia Juliana; Sanabria-Salas, Maria Carolina; Hernández-Suarez, Gustavo; García, Oscar; Silva, Camilo; Romero, Alejandro; Mejía, Juan Carlos; Miele, Lucio; Fejerman, Laura; Zabaleta, Jovanny 2016-07-01 Breast cancer is the most frequent malignancy in women worldwide. Distinct intrinsic subtypes of breast cancer have different prognoses, and their relative prevalence varies significantly among ethnic groups. Little is known about the prevalence of breast cancer intrinsic subtypes and their association with clinicopathological data and genetic ancestry in Latin Americans. Immunohistochemistry surrogates from the 2013 St. Gallen International Expert Consensus were used to classify breast cancers in 301 patients from Colombia into intrinsic subtypes. We analyzed the distribution of subtypes by clinicopathological variables. Genetic ancestry was estimated from a panel of 80 ancestry informative markers. Luminal B breast cancer subtype was the most prevalent in our population (37.2%) followed by luminal A (26.3%), non-basal triple negative (NBTN) (11.6%), basal like (9%), human epidermal growth factor receptor 2 (HER2) enriched (8.6%) and unknown (7.3%). We found statistical significant differences in distribution between Colombian region (P = 0.007), age at diagnosis (P = 0.0139), grade (P studies analyzing the molecular profiles of breast cancer in Colombian women will help us understand the molecular basis of this subtype distribution and compare the molecular characteristics of the different intrinsic subtypes in Colombian patients. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com. 3. Luminance enhancement in quantum dot light-emitting diodes fabricated with Field’s metal as the cathode Science.gov (United States) Basilio, Carlos; Oliva, Jorge; Lopez-Luke, Tzarara; Pu, Ying-Chih; Zhang, Jin Z.; Rodriguez, C. E.; de la Rosa, E. 2017-03-01 This work reports the fabrication and characterization of blue-green quantum dot light-emitting diodes (QD-LEDs) by using core/shell/shell Cd1-x Zn x Se/ZnSe/ZnS quantum dots. Poly [(9,9-bis(3‧-(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)] (PFN) was introduced in order to enhance the electron injection and also acted as a protecting layer during the deposition of the cathode (a Field’s metal sheet) on the organic/inorganic active layers at low temperature (63 °C). This procedure permitted us to eliminate the process of thermal evaporation for the deposition of metallic cathodes, which is typically used in the fabrication of OLEDs. The performance of devices made with an aluminum cathode was compared with that of devices which employed Field’s metal (FM) as the cathode. We found that the luminance and efficiency of devices with FM was ~70% higher with respect to those that employed aluminum as the cathode and their consumption of current was similar up to 13 V. We also demonstrated that the simultaneous presence of 1,2-ethanedethiol (EDT) and PFN enhanced the luminance in our devices and improved the current injection in QD-LEDs. Hence, the architecture for QD-LEDs presented in this work could be useful for the fabrication of low-cost luminescent devices. 4. Longitudinal measurements of luminance and chromatic contrast sensitivity: comparison between wavefront-guided LASIK and contralateral PRK for myopia. Science.gov (United States) Barboni, Mirella Telles Salgueiro; Feitosa-Santana, Claudia; Barreto Junior, Jackson; Lago, Marcos; Bechara, Samir Jacob; Alves, Milton Ruiz; Ventura, Dora Fix 2013-10-01 The present study aimed to compare the postoperative contrast sensitivity functions between wavefront-guided LASIK eyes and their contralateral wavefront-guided PRK eyes. The participants were 11 healthy subjects (mean age=32.4 ± 6.2 years) who had myopic astigmatism. The spatial contrast sensitivity functions were measured before and three times after the surgery. Psycho and a Cambridge graphic board (VSG 2/4) were used to measure luminance, red-green, and blue-yellow spatial contrast sensitivity functions (from 0.85 to 13.1 cycles/degree). Longitudinal analysis and comparison between surgeries were performed. There was no significant contrast sensitivity change during the one-year follow-up measurements neither for LASIK nor for PRK eyes. The comparison between procedures showed no differences at 12 months postoperative. The present data showed similar contrast sensitivities during one-year follow-up of wave-front guided refractive surgeries. Moreover, one year postoperative data showed no differences in the effects of either wavefront-guided LASIK or wavefront-guided PRK on the luminance and chromatic spatial contrast sensitivity functions. 5. Improvement in luminance of light-emitting diode using InP/ZnS quantum dot with 1-dodecanethiol ligand Science.gov (United States) Fukuda, Takeshi; Sasaki, Hironao 2018-03-01 We present the synthesis protocol of a red emissive InP/ZnS quantum dot with a 1-dodecanthiol ligand and its application to a quantum dot light-emitting diode. The ligand change from oleylamine to 1-dodecanthiol, which were connected around the InP/ZnS quantum dot, was confirmed by Fourier-transform infrared spectroscopy and thermal analysis. The absorption peak was blue-shifted by changing 1-dodecanthiol ligands from oleylamine ligands to prevent the unexpected nucleation of the InP core. In addition, the luminance of the light-emitting device was improved by using the InP/ZnS quantum dot with 1-dodecanthiol ligands, and the maximum current efficiency of 7.2 × 10-3 cd/A was achieved. The 1-dodecanthiol ligand is often used for capping to reduce the number of surface defects and/or prevent unexpected core growth, resulting in reduced Auger recombination. This result indicates that 1-dodecanthiol ligands prevent the deactivation of excitons while injecting carriers by applying a voltage, resulting in a high luminance efficiency. 6. Evaluating the Influence of Chromatic and Luminance Stimuli on SSVEPs from Behind-the-Ears and Occipital Areas Directory of Open Access Journals (Sweden) Alan Floriano 2018-02-01 Full Text Available This work presents a study of chromatic and luminance stimuli in low-, medium-, and high-frequency stimulation to evoke steady-state visual evoked potential (SSVEP in the behind-the-ears area. Twelve healthy subjects participated in this study. The electroencephalogram (EEG was measured on occipital (Oz and left and right temporal (TP9 and TP10 areas. The SSVEP was evaluated in terms of amplitude, signal-to-noise ratio (SNR, and detection accuracy using power spectral density analysis (PSDA, canonical correlation analysis (CCA, and temporally local multivariate synchronization index (TMSI methods. It was found that stimuli based on suitable color and luminance elicited stronger SSVEP in the behind-the-ears area, and that the response of the SSVEP was related to the flickering frequency and the color of the stimuli. Thus, green-red stimulus elicited the highest SSVEP in medium-frequency range, and green-blue stimulus elicited the highest SSVEP in high-frequency range, reaching detection accuracy rates higher than 80%. These findings will aid in the development of more comfortable, accurate and stable BCIs with electrodes positioned on the behind-the-ears (hairless areas. 7. Uniform Luminous Perovskite Nanofibers with Color-Tunability and Improved Stability Prepared by One-Step Core/Shell Electrospinning. Science.gov (United States) Tsai, Ping-Chun; Chen, Jung-Yao; Ercan, Ender; Chueh, Chu-Chen; Tung, Shih-Huang; Chen, Wen-Chang 2018-04-30 A one-step core/shell electrospinning technique is exploited to fabricate uniform luminous perovskite-based nanofibers, wherein the perovskite and the polymer are respectively employed in the core and the outer shell. Such a coaxial electrospinning technique enables the in situ formation of perovskite nanocrystals, exempting the needs of presynthesis of perovskite quantum dots or post-treatments. It is demonstrated that not only the luminous electrospun nanofibers can possess color-tunability by simply tuning the perovskite composition, but also the grain size of the formed perovskite nanocrystals is largely affected by the perovskite precursor stoichiometry and the polymer solution concentration. Consequently, the optimized perovskite electrospun nanofiber yields a high photoluminescence quantum yield of 30.9%, significantly surpassing the value of its thin-film counterpart. Moreover, owing to the hydrophobic characteristic of shell polymer, the prepared perovskite nanofiber is endowed with a high resistance to air and water. Its photoluminescence intensity remains constant while stored under ambient environment with a relative humidity of 85% over a month and retains intensity higher than 50% of its initial intensity while immersed in water for 48 h. More intriguingly, a white light-emitting perovskite-based nanofiber is successfully fabricated by pairing the orange light-emitting compositional perovskite with a blue light-emitting conjugated polymer. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. 8. Spatiotemporal Characteristics for the Depth from Luminance Contrast Directory of Open Access Journals (Sweden) Kazuya Matsubara 2011-05-01 Full Text Available Images with higher luminance contrast tend to be perceived closer in depth. To investigate a spatiotemporal characteristic of this effect, we evaluated subjective depth of a test stimulus with various spatial and temporal frequencies. For the purpose, the depth of a reference stimulus was matched to that of the test stimulus by changing the binocular disparity. The results showed that the test stimulus was perceived closer with higher luminance contrast for all conditions. Contrast efficiency was obtained from the contrast that provided the subjective depth for each spatiotemporal frequency. The shape of the contrast efficiency function was spatially low-pass and temporally band-pass. This characteristic is different from the one measure for a detection task. This suggests that only subset of contrast signals are used for depth from contrast. 9. Development and construction of a programmable generator of luminous impulses International Nuclear Information System (INIS) Sahuc, P. 1989-01-01 The design and construction of an impulse generator, for light waves, designed to control the characteristics of a scintillator. In these detectors, a particle gives rise to the emission of a luminous signal, which must be transformed in an electrical signal. In the present work, photomultipliers are used as luminous-electrical signal converters. The principles of operation of a scintillator, of a scintillator connected with a photodiode, and of a scintillator connected with a photomultiplier are reviewed. The analysis of the performance and of the possibilies offered by the usual generators of light, show that more suitable solutions are required. The characteristics of the electroluminescent diodes, their performances, concerning light emission and power, are investigated. The principles, the operating conditions and the performances of a generator of light, applying electroluminescent diodes, are examined. The construction and the results obtained with a prototype are presented [fr 10. Virulence of luminous vibrios to Artemia franciscana nauplii. Science.gov (United States) Soto-Rodriguez, S A; Roque, A; Lizarraga-Partida, M L; Guerra-Flores, A L; Gomez-Gill, B 2003-02-27 From healthy and diseased penaeid shrimp from Asia and the Americas, 25 luminous and 2 non-luminous bacterial strains were isolated, and 14 were phenotypically identified as Vibrio harveyi; 9 isolates produced significant mortalities (45 to 80%) in Artemia franciscana nauplii at inoculation densities of 10(5) to 10(6) CFU ml(-1) compared to the controls (unchallenged nauplii). The maximum number of bacteria ingested (bioencapsulated) by the Artemia nauplii varied from less than 10 to 10(3) CFU nauplius(-1) and no significant relationship was observed between the density of bacteria inoculated, the amount of bacteria ingested, and naupliar mortality. Significant correlations were obtained between naupliar mortality and production of proteases, phospholipases or siderophores, but not between mortality and lipase production, gelatinase production, hydrophobicity or hemolytic activity. The results suggest that virulence of the strains tested was more related to the production of particular exoenzymes than to the measured colonization factors. 11. Geometry of illumination, luminance contrast, and gloss perception. Science.gov (United States) Leloup, Frédéric B; Pointer, Michael R; Dutré, Philip; Hanselaer, Peter 2010-09-01 The influence of both the geometry of illumination and luminance contrast on gloss perception has been examined using the method of paired comparison. Six achromatic glass samples having different lightness were illuminated by two light sources. Only one of these light sources was visible in reflection by the observer. By separate adjustment of the intensity of both light sources, the luminance of both the reflected image and the adjacent off-specular surroundings could be individually varied. It was found that visual gloss appraisal did not correlate with instrumentally measured specular gloss; however, psychometric contrast seemed to be a much better correlate. It has become clear that not only the sample surface characteristics determine gloss perception: the illumination geometry could be an even more important factor. 12. Instant BlueStacks CERN Document Server Judge, Gary 2013-01-01 Get to grips with a new technology, understand what it is and what it can do for you, and then get to work with the most important features and tasks. A fast-paced, example-based approach guide for learning BlueStacks.This book is for anyone with a Mac or PC who wants to run Android apps on their computer. Whether you want to play games that are freely available for Android but not your computer, or you want to try apps before you install them on a physical device or use it as a development tool, this book will show you how. No previous experience is needed as this is written in plain English 13. An evaluation of organic light emitting diode monitors for medical applications: great timing, but luminance artifacts. Science.gov (United States) Elze, Tobias; Taylor, Christopher; Bex, Peter J 2013-09-01 In contrast to the dominant medical liquid crystal display (LCD) technology, organic light-emitting diode (OLED) monitors control the display luminance via separate light-emitting diodes for each pixel and are therefore supposed to overcome many previously documented temporal artifacts of medical LCDs. We assessed the temporal and luminance characteristics of the only currently available OLED monitor designed for use in the medical treatment field (SONY PVM2551MD) and checked the authors' main findings with another SONY OLED device (PVM2541). Temporal properties of the photometric output were measured with an optical transient recorder. Luminances of the three color primaries and white for all 256 digital driving levels (DDLs) were measured with a spectroradiometer. Between the luminances of neighboring DDLs, just noticeable differences were calculated according to a perceptual model developed for medical displays. Luminances of full screen (FS) stimuli were compared to luminances of smaller stimuli with identical DDLs. All measured luminance transition times were below 300 μs. Luminances were independent of the luminance in the preceding frame. However, for the single color primaries, up to 50.5% of the luminances of neighboring DDLs were not perceptually distinguishable. If two color primaries were active simultaneously, between 36.7% and 55.1% of neighboring luminances for increasing DDLs of the third primary were even decreasing. Moreover, luminance saturation effects were observed when too many pixels were active simultaneously. This effect was strongest for white; a small white patch was close to 400 cd/m(2), but in FS the luminance of white saturated at 162 cd/m(2). Due to different saturation levels, the luminance of FS green and FS yellow could exceed the luminance of FS white for identical DDLs. The OLED temporal characteristics are excellent and superior to those of LCDs. However, the OLEDs revealed severe perceptually relevant artifacts with 14. Night sky luminance under clear sky conditions: Theory vs. experiment International Nuclear Information System (INIS) Kocifaj, Miroslav 2014-01-01 Sky glow is caused by both natural phenomena and factors of anthropogenic origin, and of the latter ground-based light sources are the most important contributors for they emit the spatially linked spectral radiant intensity distribution of artificial light sources, which are further modulated by local atmospheric optics and perceived as the diffuse light of a night sky. In other words, sky glow is closely related to a city's shape and pattern of luminaire distribution, in practical effect an almost arbitrary deployment of random orientation of heterogeneous electrical light sources. Thus the luminance gradation function measured in a suburban zone or near the edges of a city is linked to the City Pattern or vice versa. It is shown that clear sky luminance/radiance data recorded in an urban area can be used to retrieve the bulk luminous/radiant intensity distribution if some a-priori information on atmospheric aerosols is available. For instance, the single scattering albedo of aerosol particles is required under low turbidity conditions, as demonstrated on a targeted experiment in the city of Frýdek-Mistek. One of the main advantages of the retrieval method presented in this paper is that the single scattering approximation is satisfactorily accurate in characterizing the light field near the ground because the dominant contribution to the sky glow has originated from beams propagated along short optical paths. - Highlights: • Urban sky glow is interpreted in terms of city emission function. • Luminance function in a suburban zone is linked to the City Pattern. • Single scattering approximation is applicable in modeling urban sky glow. • Information on aerosols represents valuable inputs to the retrieval procedure. • Sky glow patterns vary with light source distribution and spectral emission 15. Selected luminal mucosal complications of adult celiac disease OpenAIRE Freeman, Hugh 2009-01-01 Hugh J FreemanDepartment of Medicine (Gastroenterology), University of British Columbia, Vancouver, BC, CanadaAbstract: Celiac disease is a gluten-dependent intestinal disorder that appears to be associated with several clinical conditions. Some involve the luminal mucosa of the stomach and intestinal tract and may, occasionally, complicate the course of celiac disease. Collagenous colitis has been associated with celiac disease and may lead to chronic diarrhea. Conversely, some of t... 16. Underlying mechanisms of transient luminous events: a review OpenAIRE V. V. Surkov; M. Hayakawa 2012-01-01 Transient luminous events (TLEs) occasionally observed above a strong thunderstorm system have been the subject of a great deal of research during recent years. The main goal of this review is to introduce readers to recent theories of electrodynamics processes associated with TLEs. We examine the simplest versions of these theories in order to make their physics as transparent as possible. The study is begun with the conventional mechanism for air breakdown at stratospheric... 17. Enigmatic sub-luminous accreting neutron stars in our Galaxy NARCIS (Netherlands) Wijnands, R. 2008-01-01 During the last few years a class of enigmatic sub-luminous accreting neutron stars has been found in our Galaxy. They have peak X-ray luminosities (2-10 keV) of a few times 10(34) erg s(−1) to a few times 10(35) erg s(−1), and both persistent and transient sources have been found. I present a short 18. Dynamic encoding of natural luminance sequences by LGN bursts. Directory of Open Access Journals (Sweden) Nicholas A Lesica 2006-07-01 Full Text Available In the lateral geniculate nucleus (LGN of the thalamus, visual stimulation produces two distinct types of responses known as tonic and burst. Due to the dynamics of the T-type Ca(2+ channels involved in burst generation, the type of response evoked by a particular stimulus depends on the resting membrane potential, which is controlled by a network of modulatory connections from other brain areas. In this study, we use simulated responses to natural scene movies to describe how modulatory and stimulus-driven changes in LGN membrane potential interact to determine the luminance sequences that trigger burst responses. We find that at low resting potentials, when the T channels are de-inactivated and bursts are relatively frequent, an excitatory stimulus transient alone is sufficient to evoke a burst. However, to evoke a burst at high resting potentials, when the T channels are inactivated and bursts are relatively rare, prolonged inhibitory stimulation followed by an excitatory transient is required. We also observe evidence of these effects in vivo, where analysis of experimental recordings demonstrates that the luminance sequences that trigger bursts can vary dramatically with the overall burst percentage of the response. To characterize the functional consequences of the effects of resting potential on burst generation, we simulate LGN responses to different luminance sequences at a range of resting potentials with and without a mechanism for generating bursts. Using analysis based on signal detection theory, we show that bursts enhance detection of specific luminance sequences, ranging from the onset of excitatory sequences at low resting potentials to the offset of inhibitory sequences at high resting potentials. These results suggest a dynamic role for burst responses during visual processing that may change according to behavioral state. 19. THE MASSIVE STAR POPULATION IN M101. I. THE IDENTIFICATION AND SPATIAL DISTRIBUTION OF THE VISUALLY LUMINOUS STARS International Nuclear Information System (INIS) Grammer, Skyler; Humphreys, Roberta M. 2013-01-01 An increasing number of non-terminal giant eruptions are being observed by modern supernova and transient surveys. But very little is known about the origin of these giant eruptions and their progenitors, many of which are presumably very massive, evolved stars. Motivated by the small number of progenitors positively associated with these giant eruptions, we have begun a survey of the evolved massive star populations in nearby galaxies. The nearby, nearly face-on, giant spiral M101 is an excellent laboratory for studying a large population of very massive stars. In this paper, we present BVI photometry obtained from archival HST/ACS Wide Field Camera images of M101. We have produced a catalog of luminous stars with photometric errors <10% for V < 24.5 and 50% completeness down to V ∼ 26.5 even in regions of high stellar crowding. Using color and luminosity criteria, we have identified candidate luminous OB-type stars and blue supergiants, yellow supergiants, and red supergiants for future observation. We examine their spatial distributions across the face of M101 and find that the ratio of blue to red supergiants decreases by two orders of magnitude over the radial extent of M101 corresponding to 0.5 dex in metallicity. We discuss the resolved stellar content in the giant star-forming complexes NGC 5458, 5453, 5461, 5451, 5462, and 5449 and discuss their color-magnitude diagrams in conjunction with the spatial distribution of the stars to determine their spatio-temporal formation histories 20. Blue fluorescent organic light emitting diodes with multilayered graphene anode International Nuclear Information System (INIS) Hwang, Joohyun; Choi, Hong Kyw; Moon, Jaehyun; Shin, Jin-Wook; Joo, Chul Woong; Han, Jun-Han; Cho, Doo-Hee; Huh, Jin Woo; Choi, Sung-Yool; Lee, Jeong-Ik; Chu, Hye Yong 2012-01-01 As an innovative anode for organic light emitting devices (OLEDs), we have investigated graphene films. Graphene has importance due to its huge potential in flexible OLED applications. In this work, graphene films have been catalytically grown and transferred to the glass substrate for OLED fabrications. We have successfully fabricated 2 mm × 2 mm device area blue fluorescent OLEDs with graphene anodes which showed 2.1% of external quantum efficiency at 1000 cd/m 2 . This is the highest value reported among fluorescent OLEDs using graphene anodes. Oxygen plasma treatment on graphene has been found to improve hole injections in low voltage regime, which has been interpreted as oxygen plasma induced work function modification. However, plasma treatment also increases the sheet resistance of graphene, limiting the maximum luminance. In summary, our works demonstrate the practical possibility of graphene as an anode material for OLEDs and suggest a processing route which can be applied to various graphene related devices. 1. Wavelength and ambient luminance dependence of laser eye dazzle. Science.gov (United States) Williamson, Craig A; McLin, Leon N; Rickman, J Michael; Manka, Michael A; Garcia, Paul V; Kinerk, Wesley T; Smith, Peter A 2017-10-10 A series of experiments has been conducted to quantify the effects of laser wavelength and ambient luminance on the severity of laser eye dazzle experienced by human subjects. Eight laser wavelengths in the visible spectrum were used (458-647 nm) across a wide range of ambient luminance conditions (0.1-10,000 cd·m -2 ). Subjects were exposed to laser irradiance levels up to 600 μW·cm -2 and were asked to recognize the orientation of optotypes at varying eccentricities up to 31.6 deg of visual angle from the laser axis. More than 40,000 data points were collected from 14 subjects (ages 23-64), and these were consolidated into a series of obscuration angles for comparison to a theoretical model of laser eye dazzle. Scaling functions were derived to allow the model to predict the effects of laser dazzle on vision more accurately by including the effects of ambient luminance and laser wavelength. The updated model provides an improved match to observed laser eye dazzle effects across the full range of conditions assessed. The resulting model will find use in a variety of laser safety applications, including the estimation of maximum dazzle exposure and nominal ocular dazzle distance values. 2. Relationships between luminance and visual acuity in the rhesus monkey Science.gov (United States) Cavonius, C. R.; Robbins, D. O. 1973-01-01 1. The ability of rhesus monkeys to detect the gap in Landolt ring test-objects that were presented against background luminances between 5 × 10-5 cd/m2 and 5 × 103 cd/m2 was compared with similar human data. 2. At high luminance-levels the acuity of human observers is slightly better than that of rhesus, but rhesus have better acuity at scotopic luminance-levels. Both species have distinct photopic and scotopic acuity functions that cross at 6 × 10-3 cd/m2. 3. The threshold for light detection is estimated to be the same for both species when specified in quanta incident on the retina. 4. It is concluded that the receptor and neural mechanisms that mediate visual-acuity function similarly in rhesus and man, and that the differences in acuity that were measured in the two species may be attributed to optical rather than to physiological factors. PMID:4199366 3. Effect of the green/blue flicker matrix for P300-based brain–computer interface: an EEG–fMRI study. Directory of Open Access Journals (Sweden) Shiro eIkegami 2012-07-01 Full Text Available The visual P300 brain–computer interface (BCI, a popular system for EEG-based BCI, utilizes the P300 event-related potential to select an icon arranged in a flicker matrix. In the conventional P300 BCI speller paradigm, white/gray luminance intensification of each row/column in the matrix is used. In an earlier study, we applied green/blue luminance and chromatic change in the P300 BCI system and reported that this luminance and chromatic flicker matrix was associated with better performance and greater subject comfort compared with the conventional white/gray luminance flicker matrix. In this study, we used simultaneous EEG-fMRI recordings to identify brain areas that were more enhanced in the green/blue flicker matrix than in the white/gray flicker matrix, as these may highlight areas devoted to improved P300-BCI performance. The peak of the positive wave in the EEG data was detected under both conditions, and the peak amplitudes were larger at the parietal and occipital electrodes, particularly in the late components, under the green/blue condition than under the white/gray condition. fMRI data showed activation in the bilateral parietal and occipital cortices, and these areas, particularly those in the right hemisphere, were more activated under the green/blue condition than under the white/gray condition. The parietal and occipital regions more involved in the green/blue condition were part of the areas devoted to conventional P300s. These results suggest that the green/blue flicker matrix was useful for enhancing the so-called P300 responses. 4. Life prediction of OLED for constant-stress accelerated degradation tests using luminance decaying model Energy Technology Data Exchange (ETDEWEB) Zhang, Jianping, E-mail: jpzhanglzu@163.com [College of Energy and Mechanical Engineering, Shanghai University of Electric Power, Shanghai 200090 (China); Li, Wenbin [College of Energy and Mechanical Engineering, Shanghai University of Electric Power, Shanghai 200090 (China); Cheng, Guoliang; Chen, Xiao [Shanghai Tianyi Electric Co., Ltd., Shanghai 201611 (China); Wu, Helen [School of Computing, Engineering and Mathematics, University of Western Sydney, Sydney 2751 (Australia); Herman Shen, M.-H. [Department of Mechanical and Aerospace Engineering, The Ohio State University, OH 43210 (United States) 2014-10-15 In order to acquire the life information of organic light emitting diode (OLED), three groups of constant stress accelerated degradation tests are performed to obtain the luminance decaying data of samples under the condition that the luminance and the current are respectively selected as the indicator of performance degradation and the test stress. Weibull function is applied to describe the relationship between luminance decaying and time, least square method (LSM) is employed to calculate the shape parameter and scale parameter, and the life prediction of OLED is achieved. The numerical results indicate that the accelerated degradation test and the luminance decaying model reveal the luminance decaying law of OLED. The luminance decaying formula fits the test data very well, and the average error of fitting value compared with the test data is small. Furthermore, the accuracy of the OLED life predicted by luminance decaying model is high, which enable rapid estimation of OLED life and provide significant guidelines to help engineers make decisions in design and manufacturing strategy from the aspect of reliability life. - Highlights: • We gain luminance decaying data by accelerated degradation tests on OLED. • The luminance decaying model objectively reveals the decaying law of OLED luminance. • The least square method (LSM) is employed to calculate Weibull parameters. • The plan designed for accelerated degradation tests proves to be feasible. • The accuracy of the OLED life and the luminance decaying fitting formula is high. 5. Robust brightness enhancement across a luminance range of the glare illusion. Science.gov (United States) Tamura, Hideki; Nakauchi, Shigeki; Koida, Kowa 2016-01-01 The glare illusion refers to brightness enhancement and the perception of a self-luminous appearance that occurs when a central region is surrounded by a luminance gradient. The center region appears to be a light source, with its light dispersing into the surrounding region. If the luminous edge is critical for generating the illusion, modulating the perceived luminance of the image, and switching its appearance from luminous to nonluminous, would have a strong impact on lightness and brightness estimation. Here, we quantified the illusion in two ways, by assessing brightness enhancement and examining whether the center region appeared luminous. Thus, we could determine whether the two effects occurred jointly or independently. We examined a wide luminance range of center regions, from 0 to 200% relative to background. Brightness enhancement in the illusion was observed for a wide range of luminances (20% to 200% relative to background), while a luminous-white appearance was observed when the center region luminance was 145% of the background. These results exclude the possibility that brightness enhancement occurs because the stimuli appear self-luminous. We suggest that restoring the original image intensity precedes the perceptual process of lightness estimation. 6. Life prediction of OLED for constant-stress accelerated degradation tests using luminance decaying model International Nuclear Information System (INIS) Zhang, Jianping; Li, Wenbin; Cheng, Guoliang; Chen, Xiao; Wu, Helen; Herman Shen, M.-H. 2014-01-01 In order to acquire the life information of organic light emitting diode (OLED), three groups of constant stress accelerated degradation tests are performed to obtain the luminance decaying data of samples under the condition that the luminance and the current are respectively selected as the indicator of performance degradation and the test stress. Weibull function is applied to describe the relationship between luminance decaying and time, least square method (LSM) is employed to calculate the shape parameter and scale parameter, and the life prediction of OLED is achieved. The numerical results indicate that the accelerated degradation test and the luminance decaying model reveal the luminance decaying law of OLED. The luminance decaying formula fits the test data very well, and the average error of fitting value compared with the test data is small. Furthermore, the accuracy of the OLED life predicted by luminance decaying model is high, which enable rapid estimation of OLED life and provide significant guidelines to help engineers make decisions in design and manufacturing strategy from the aspect of reliability life. - Highlights: • We gain luminance decaying data by accelerated degradation tests on OLED. • The luminance decaying model objectively reveals the decaying law of OLED luminance. • The least square method (LSM) is employed to calculate Weibull parameters. • The plan designed for accelerated degradation tests proves to be feasible. • The accuracy of the OLED life and the luminance decaying fitting formula is high 7. MRI texture analysis in differentiating luminal A and luminal B breast cancer molecular subtypes - a feasibility study. Science.gov (United States) Holli-Helenius, Kirsi; Salminen, Annukka; Rinta-Kiikka, Irina; Koskivuo, Ilkka; Brück, Nina; Boström, Pia; Parkkola, Riitta 2017-12-29 The aim of this study was to use texture analysis (TA) of breast magnetic resonance (MR) images to assist in differentiating estrogen receptor (ER) positive breast cancer molecular subtypes. Twenty-seven patients with histopathologically proven invasive ductal breast cancer were selected in preliminary study. Tumors were classified into molecular subtypes: luminal A (ER-positive and/or progesterone receptor (PR)-positive, human epidermal growth factor receptor type 2 (HER2) -negative, proliferation marker Ki-67 MaZda. Texture parameters and tumour volumes were correlated with tumour prognostic factors. Textural differences were observed mainly in precontrast images. The two most discriminative texture parameters to differentiate luminal A and luminal B subtypes were sum entropy and sum variance (p = 0.003). The AUCs were 0.828 for sum entropy (p = 0.004), and 0.833 for sum variance (p = 0.003), and 0.878 for the model combining texture features sum entropy, sum variance (p = 0.001). In the LOOCV, the AUC for model combining features sum entropy and sum variance was 0.876. Sum entropy and sum variance showed positive correlation with higher Ki-67 index. Luminal B types were larger in volume and moderate correlation between larger tumour volume and higher Ki-67 index was also observed (r = 0.499, p = 0.008). Texture features which measure randomness, heterogeneity or smoothness and homogeneity may either directly or indirectly reflect underlying growth patterns of breast tumours. TA and volumetric analysis may provide a way to evaluate the biologic aggressiveness of breast tumours and provide aid in decisions regarding therapeutic efficacy. 8. Red sprites and blue jets: Thunderstorm-excited optical emissions in the stratosphere, mesosphere, and ionosphere International Nuclear Information System (INIS) Sentman, D.D.; Wescott, E.M. 1995-01-01 Recent low light level monochrome television observations obtained from the ground and from the space shuttle, and low light level color and monochrome television images obtained from aboard jet aircraft, have shown that intense lightning in mesoscale thunderstorm systems may excite at least two distinct types of optical emissions that together span the space between the tops of some thunderstorms and the ionosphere. The first of these emissions, dubbed ''sprites,'' are luminous red structures that typically span the altitude range 60--90 km, often with faint bluish tendrils dangling below. A second, rarer, type of luminous emission are ''blue jets'' that appear to spurt upward out of the anvil top in narrow cones to altitudes of 40--50 km at speeds of ∼100 km/s. In this paper the principal observational characteristics of sprites and jets are presented, and several proposed production mechanisms are reviewed. copyright 1995 American Institute of Physics 9. Luminous bacteria cultured from fish guts in the Gulf of Oman. Science.gov (United States) Makemson, J C; Hermosa, G V 1999-01-01 The incidence of culturable luminous bacteria in Omani market fish guts was correlated to habitat type amongst 109 species of fish. Isolated representative luminous bacteria were compared to known species using the Biolog system (95 traits/isolate) and cluster analysis, which showed that the main taxa present in fish guts were clades related to Vibrio harveyi and Photobacterium species with sporadic incidence of P. phosphoreum. The luminous isolates from gut of the slip-mouth (barred pony fish), Leiognathus fasciatus, were mainly a type related to Photobacterium but phenotypically different from known species. These luminous gut bacteria were identical with the bacteria in the light organ, indicating that the light organ supplies a significant quantity of luminous bacteria to the gut. In many of the fish that lack light organs, luminous bacteria were also the dominant bacterial type in the gut, while in some others luminous bacteria were encountered sporadically and at low densities, reflecting the incidence of culturable luminous bacteria in seawater. Pelagic fish contained the highest incidence of culturable luminous bacteria and reef-associated fish the lowest. No correlation was found between the incidence of culturable luminous bacteria and the degree to which fish produce a melanin-covered gut. Copyright 1999 John Wiley & Sons, Ltd. 10. Photobacterium kishitanii sp. nov., a luminous marine bacterium symbiotic with deep-sea fishes. Science.gov (United States) Ast, Jennifer C; Cleenwerck, Ilse; Engelbeen, Katrien; Urbanczyk, Henryk; Thompson, Fabiano L; De Vos, Paul; Dunlap, Paul V 2007-09-01 Six representatives of a luminous bacterium commonly found in association with deep, cold-dwelling marine fishes were isolated from the light organs and skin of different fish species. These bacteria were Gram-negative, catalase-positive, and weakly oxidase-positive or oxidase-negative. Morphologically, cells of these strains were coccoid or coccoid-rods, occurring singly or in pairs, and motile by means of polar flagellation. After growth on seawater-based agar medium at 22 degrees C for 18 h, colonies were small, round and white, with an intense cerulean blue luminescence. Analysis of 16S rRNA gene sequence similarity placed these bacteria in the genus Photobacterium. Phylogenetic analysis based on seven housekeeping gene sequences (16S rRNA gene, gapA, gyrB, pyrH, recA, rpoA and rpoD), seven gene sequences of the lux operon (luxC, luxD, luxA, luxB, luxF, luxE and luxG) and four gene sequences of the rib operon (ribE, ribB, ribH and ribA), resolved the six strains as members of the genus Photobacterium and as a clade distinct from other species of Photobacterium. These strains were most closely related to Photobacterium phosphoreum and Photobacterium iliopiscarium. DNA-DNA hybridization values between the designated type strain, Photobacterium kishitanii pjapo.1.1(T), and P. phosphoreum LMG 4233(T), P. iliopiscarium LMG 19543(T) and Photobacterium indicum LMG 22857(T) were 51, 43 and 19 %, respectively. In AFLP analysis, the six strains clustered together, forming a group distinct from other analysed species. The fatty acid C(17 : 0) cyclo was present in these bacteria, but not in P. phosphoreum, P. iliopiscarium or P. indicum. A combination of biochemical tests (arginine dihydrolase and lysine decarboxylase) differentiates these strains from P. phosphoreum and P. indicum. The DNA G+C content of P. kishitanii pjapo.1.1(T) is 40.2 %, and the genome size is approximately 4.2 Mbp, in the form of two circular chromosomes. These strains represent a novel species, for 11. Photometry of faint blue stars International Nuclear Information System (INIS) Kilkenny, D.; Hill, P.W.; Brown, A. 1977-01-01 Photometry on the uvby system is given for 61 faint blue stars. The stars are classified by means of the Stromgren indices, using criteria described in a previous paper (Kilkenny and Hill (1975)). (author) 12. Ecology of blue straggler stars CERN Document Server Carraro, Giovanni; Beccari, Giacomo 2015-01-01 The existence of blue straggler stars, which appear younger, hotter, and more massive than their siblings, is at odds with a simple picture of stellar evolution. Such stars should have exhausted their nuclear fuel and evolved long ago to become cooling white dwarfs. They are found to exist in globular clusters, open clusters, dwarf spheroidal galaxies of the Local Group, OB associations and as field stars. This book summarises the many advances in observational and theoretical work dedicated to blue straggler stars. Carefully edited extended contributions by well-known experts in the field cover all the relevant aspects of blue straggler stars research: Observations of blue straggler stars in their various environments; Binary stars and formation channels; Dynamics of globular clusters; Interpretation of observational data and comparison with models. The book also offers an introductory chapter on stellar evolution written by the editors of the book. 13. China Mobile: Expanding "Blue Ocean" Institute of Scientific and Technical Information of China (English) 2006-01-01 Driving force is crucial for realizing high-speed growth. The strong driving force from "Blue Ocean Strategy" is an important advantage for China Mobile to realize harmonious and leap-forward development. 14. Development of a LED based standard for luminous flux Science.gov (United States) Sardinha, André; Ázara, Ivo; Torres, Miguel; Menegotto, Thiago; Grieneisen, Hans Peter; Borghi, Giovanna; Couceiro, Iakyra; Zim, Alexandre; Muller, Filipe 2018-03-01 Incandescent lamps, simple artifacts with radiation spectrum very similar to a black-body emitter, are traditional standards in photometry. Nowadays LEDs are broadly used in lighting, with great variety of spectra, and it is convenient to use standards for photometry with spectral distribution similar to that of the measured artifact. Research and development of such standards occur in several National Metrology Institutes. In Brazil, Inmetro is working on a practical solution for providing a LED based standard to be used for luminous flux measurements in the field of general lighting. This paper shows the measurements made for the developing of a prototype, that in sequence will be characterized in photometric quantities. 15. Blue Organic Light-Emitting Diodes Based on Triphenylene Derivatives Energy Technology Data Exchange (ETDEWEB) Kim, Seul Ong; Jang, Heung Soo; Yoon, Seung Soo [Sungkyunkwan Univ., Suwon (Korea, Republic of); Lee, Seok Jae; Kim, Young Kwan [Hongik Univ., Seoul (Korea, Republic of) 2013-08-15 A series of blue fluorescent emitters based on triphenylene derivatives were synthesized via the Diels -Alder reaction in moderate yields. The electronic absorption and emission characteristics of the new functional materials were affected by the nature of the substituent on the triphenylene nucleus. Multilayered OLEDs were fabricated with a device structure of: ITO/NPB (50 nm)/EML (30 nm)/Bphen (30 nm)/Liq (2.0 nm)/Al (100 nm). All devices showed efficient blue emissions. Among those, a device using 1 gives the best performances with a high brightness (978 cd m{sup -2} at 8.0 V) and high efficiencies (a luminous efficiency of 0.80 cd/A, a power efficiency of 0.34 lm/W and an external quantum efficiency of 0.73% at 20 mA/cm{sup 2}). The peak wavelength of the electroluminescence was 455 nm with CIE{sub x,y} coordinates of (0.17, 0.14) at 8.0 V. 16. Power blue and green laser diodes and their applications Science.gov (United States) Hager, Thomas; Strauß, Uwe; Eichler, Christoph; Vierheilig, Clemens; Tautz, Sönke; Brüderl, Georg; Stojetz, Bernhard; Wurm, Teresa; Avramescu, Adrian; Somers, André; Ristic, Jelena; Gerhard, Sven; Lell, Alfred; Morgott, Stefan; Mehl, Oliver 2013-03-01 InGaN based green laser diodes with output powers up to 50mW are now well established for variety of applications ranging from leveling to special lighting effects and mobile projection of 12lm brightness. In future the highest market potential for visible single mode profile lasers might be laser projection of 20lm. Therefore direct green single-mode laser diodes with higher power are required. We found that self heating was the limiting factor for higher current operation. We present power-current characteristics of improved R and D samples with up to 200mW in cw-operation. An optical output power of 100mW is reached at 215mA, a current level which is suitable for long term operation. Blue InGaN laser diodes are also the ideal source for phosphor based generation of green light sources of high luminance. We present a light engine based on LARP (Laser Activated Remote Phosphor) which can be used in business projectors of several thousand lumens on screen. We discuss the advantages of a laser based systems in comparison with LED light engines. LARP requires highly efficient blue power laser diodes with output power above 1W. Future market penetration of LARP will require lower costs. Therefore we studied new designs for higher powers levels. R and D chips with power-current characteristics up to 4W in continuous wave operation on C-mount at 25°C are presented. 17. Efficiency and stability of a phosphor-conversion white light source using a blue laser diode Directory of Open Access Journals (Sweden) G. Ledru 2014-10-01 Full Text Available A white light source using direct phosphor-conversion excited by a blue laser diode is presented. In this preliminary study we have investigated the influence of phosphor’s thickness and operating current of the laser diode over the (x, y chromaticity coordinates, Correlated Color Temperature (CCT and Color Rendering Index (CRI. The best values found were 4000 K and 94. A 40 lm/W luminous efficacy was achieved together with a CRI close to 90 for an operating current of 0.8 A. Those values, to the best of our knowledge, were not previously reported in the literature. 18. Luminal epithelial cells within the mammary gland can produce basal cells upon oncogenic stress. Science.gov (United States) Hein, S M; Haricharan, S; Johnston, A N; Toneff, M J; Reddy, J P; Dong, J; Bu, W; Li, Y 2016-03-17 In the normal mammary gland, the basal epithelium is known to be bipotent and can generate either basal or luminal cells, whereas the luminal epithelium has not been demonstrated to contribute to the basal compartment in an intact and normally developed mammary gland. It is not clear whether cellular heterogeneity within a breast tumor results from transformation of bipotent basal cells or from transformation and subsequent basal conversion of the more differentiated luminal cells. Here we used a retroviral vector to express an oncogene specifically in a small number of the mammary luminal epithelial cells and tested their potential to produce basal cells during tumorigenesis. This in-vivo lineage-tracing work demonstrates that luminal cells are capable of producing basal cells on activation of either polyoma middle T antigen or ErbB2 signaling. These findings reveal the plasticity of the luminal compartment during tumorigenesis and provide an explanation for cellular heterogeneity within a cancer. 19. Psychophysical and physiological responses to gratings with luminance and chromatic components of different spatial frequencies. Science.gov (United States) Cooper, Bonnie; Sun, Hao; Lee, Barry B 2012-02-01 Gratings that contain luminance and chromatic components of different spatial frequencies were used to study the segregation of signals in luminance and chromatic pathways. Psychophysical detection and discrimination thresholds to these compound gratings, with luminance and chromatic components of the one either half or double the spatial frequency of the other, were measured in human observers. Spatial frequency tuning curves for detection of compound gratings followed the envelope of those for luminance and chromatic gratings. Different grating types were discriminable at detection threshold. Fourier analysis of physiological responses of macaque retinal ganglion cells to compound waveforms showed chromatic information to be restricted to the parvocellular pathway and luminance information to the magnocellular pathway. Taken together, the human psychophysical and macaque physiological data support the strict segregation of luminance and chromatic information in independent channels, with the magnocellular and parvocellular pathways, respectively, serving as likely the physiological substrates. © 2012 Optical Society of America 20. Effects of electron transport material on blue organ light-emitting diode with fluorescent dopant of BCzVBi. Science.gov (United States) Meng, Mei; Song, Wook; Kim, You-Hyun; Lee, Sang-Youn; Jhun, Chul-Gyu; Zhu, Fu Rong; Ryu, Dae Hyun; Kim, Woo-Young 2013-01-01 High efficiency blue organic light emitting diodes (OLEDs), based on 2-me-thyl-9,10-di(2-naphthyl) anthracene (MADN) doped with 4,4'-bis(9-ethyl-3-carbazovinylene)-1,1'-biphenyl (BCzVBi), were fabricated using two different electron transport layers (ETLs) of tris(8-hydroxyquinolino)-aluminum (Alq3) and 4,7-di-phenyl-1,10-phenanthroline (Bphen). Bphen ETL layers favored the efficient hole-electron recombination in the emissive layer of the BCzVBi-doped blue OLEDs, leading to high luminous efficiency and quantum efficiency of 8.34 cd/A at 100 mA/cm2 and 5.73% at 100 cd/m2, respectively. Maximum luminance of blue OLED with Bphen ETL and Alq3 ETL were 10670 cd/m2, and CIExy coordinates of blue OLEDs were (0.180, 0279) and (0.155, 0.212) at 100 cd/m2. 1. The Highly Luminous Type Ibn Supernova ASASSN-14ms DEFF Research Database (Denmark) Vallely, P. J.; Prieto, J. L.; Stanek, K. Z. 2018-01-01 We present photometric and spectroscopic follow-up observations of the highly luminous Type Ibn supernova ASASSN-14ms, which was discovered on UT 2014-12-26.61 atm_V \\sim 16.5$. With a peak absolute$V$-band magnitude brighter than$-20.5$, a peak bolometric luminosity of$1.7 \\times 10......^{44}$ergs s$^{-1}$, and a total radiated energy of$2.1 \\times 10^{50}$ergs, ASASSN-14ms is one of the most luminous Type Ibn supernovae yet discovered. In simple models, the most likely power source for this event is a combination of the radioactive decay of$^{56}$Ni and$^{56}$Co at late times...... and the interaction of supernova ejecta with the progenitor's circumstellar medium at early times, although we cannot rule out the possibility of a magnetar-powered light curve. The presence of a dense circumstellar medium is indicated by the intermediate-width He I features in the spectra. The faint ($m_g \\sim 21...
2. Effect of americium-241 on luminous bacteria. Role of peroxides
Energy Technology Data Exchange (ETDEWEB)
Alexandrova, M., E-mail: maka-alexandrova@rambler.r [Siberian Federal University, Svobodny 79, 660041 Krasnoyarsk (Russian Federation); Rozhko, T. [Siberian Federal University, Svobodny 79, 660041 Krasnoyarsk (Russian Federation); Vydryakova, G. [Institute of Biophysics SB RAS, Akademgorodok 50, 660036 Krasnoyarsk (Russian Federation); Kudryasheva, N. [Siberian Federal University, Svobodny 79, 660041 Krasnoyarsk (Russian Federation); Institute of Biophysics SB RAS, Akademgorodok 50, 660036 Krasnoyarsk (Russian Federation)
2011-04-15
The effect of americium-241 ({sup 241}Am), an alpha-emitting radionuclide of high specific activity, on luminous bacteria Photobacterium phosphoreum was studied. Traces of {sup 241}Am in nutrient media (0.16-6.67 kBq/L) suppressed the growth of bacteria, but enhanced luminescence intensity and quantum yield at room temperature. Lower temperature (4 {sup o}C) increased the time of bacterial luminescence and revealed a stage of bioluminescence inhibition after 150 h of bioluminescence registration start. The role of conditions of exposure the bacterial cells to the {sup 241}Am is discussed. The effect of {sup 241}Am on luminous bacteria was attributed to peroxide compounds generated in water solutions as secondary products of radioactive decay. Increase of peroxide concentration in {sup 241}Am solutions was demonstrated; and the similarity of {sup 241}Am and hydrogen peroxide effects on bacterial luminescence was revealed. The study provides a scientific basis for elaboration of bioluminescence-based assay to monitor radiotoxicity of alpha-emitting radionuclides in aquatic solutions. - Highlights: {yields} Am-241 in water solutions (A = 0.16-6.7 kBq/L) suppresses bacterial growth.{yields} Am-241 (A = 0.16-6.7 kBq/L) stimulate bacterial luminescence. {yields} Peroxides, secondary radiolysis products, cause increase of bacterial luminescence.
3. Luminal digestion of lactoferrin in suckling and weanling rats
International Nuclear Information System (INIS)
Britton, J.R.; Koldovsky, O.
1987-01-01
The development of luminal digestion of lactoferrin was evaluated in vitro by incubating 125 I-labeled lactoferrin with fluid flushed from the stomach and small intestine of 12-day-old suckling and 31-day-old weanling rats, followed by measurement of radioactivity in trichloroacetic acid-soluble material. Gastric hydrolysis of lactoferrin at pH 3.2 in the weanling was 20-fold greater than that in the suckling. In the small intestine at neutral pH, luminal degradation of lactoferrin was minimal in the suckling but increased significantly after weaning, with maximal degradative capacity demonstrable in the midjejunum. Sephadex G-75 chromatography of intestinal acid-soluble breakdown products revealed two peaks of radioactivity, each comprising 40-45% of the total product; analysis of intestinal acid-precipitable products by polyacrylamide gel electrophoresis yielded several discrete lower molecular weight species. Food deprivation for 12 h/100 g body wt decreased lactoferrin degradation in the weanling jejunum and midjejunum. The findings suggest that lactoferrin digestion may vary with respect to postnatal age of the organism, segment of the gastrointestinal tract, and dietary state. In the young animal, lactoferrin degradation is minimal, and consequently its potential for biological function may be high
4. [Acute blue urticaria following subcutaneous injection of patent blue dye].
Science.gov (United States)
Hamelin, A; Vial-Dupuy, A; Lebrun-Vignes, B; Francès, C; Soria, A; Barete, S
2015-11-01
Patent blue (PB) is a lymphatic vessel dye commonly used in France for sentinel lymph node detection in breast cancer, and less frequently in melanoma, and which may induce hypersensitivity reactions. We report a case of acute blue urticaria occurring within minutes of PB injection. Ten minutes after PB injection for sentinel lymph node detection during breast cancer surgery, a 49-year-old woman developed generalised acute blue urticaria and eyelid angioedema without bronchospasm or haemodynamic disturbance, but requiring discontinuation of surgery. Skin testing using PB and the anaesthetics given were run 6 weeks after the episode and confirmed PB allergy. PB was formally contra-indicated. Immediate hypersensitivity reactions to PB have been reported for between 0.24 and 2.2% of procedures. Such reactions are on occasion severe, chiefly involving anaphylactic shock. Two mechanisms are probably associated: non-specific histamine release and/or an IgE-mediated mechanism. Skin tests are helpful in confirming the diagnosis of PB allergy. Blue acute urticaria is one of the clinical manifestations of immediate hypersensitivity reactions to patent blue dye. Skin tests must be performed 6 weeks after the reaction in order to confirm the diagnosis and formally contra-indicate this substance. Copyright © 2015 Elsevier Masson SAS. All rights reserved.
5. Application of radioisotope for radio-luminous watch and clock industry in Japan
International Nuclear Information System (INIS)
Murayama, Yoshihiko
1981-01-01
6. Identification of Different Classes of Luminal Progenitor Cells within Prostate Tumors
Directory of Open Access Journals (Sweden)
Supreet Agarwal
2015-12-01
Full Text Available Primary prostate cancer almost always has a luminal phenotype. However, little is known about the stem/progenitor properties of transformed cells within tumors. Using the aggressive Pten/Tp53-null mouse model of prostate cancer, we show that two classes of luminal progenitors exist within a tumor. Not only did tumors contain previously described multipotent progenitors, but also a major population of committed luminal progenitors. Luminal cells, sorted directly from tumors or grown as organoids, initiated tumors of adenocarcinoma or multilineage histological phenotypes, which is consistent with luminal and multipotent differentiation potentials, respectively. Moreover, using organoids we show that the ability of luminal-committed progenitors to self-renew is a tumor-specific property, absent in benign luminal cells. Finally, a significant fraction of luminal progenitors survived in vivo castration. In all, these data reveal two luminal tumor populations with different stem/progenitor cell capacities, providing insight into prostate cancer cells that initiate tumors and can influence treatment response.
7. Signal detectability of mammography depends on film-screen system and luminance of view box
International Nuclear Information System (INIS)
Maeda, Fumie; Ogura, Akio; Miyai, Akira
2003-01-01
High-density film and the high-luminance view-box system are being recommended for mammograms owing to the improved detection of masses. However, this system causes an increase in radiation. Therefore, the purpose of this study was to assess whether the detection of masses would improve using the normal-luminance view box and normal-density film with different types of contrast systems. Low-contrast detection using receiver operating characteristic (ROC) analysis and high-contrast detection using an American College of Radiology (ACR) phantom were evaluated for the following systems: high-density film and high-luminance view box, normal-density film and normal-luminance view box, and normal-density film with wide latitude and normal-luminance view box. The results showed no significant variation in the detectability of the system with high-density film and high-luminance view box and the normal-density film with wide latitude and normal-luminance view box. However, in terms of low-contrast visibility, the system using normal-density film and normal-luminance view box was significantly reduced in comparison with the others. Therefore, the system with normal-density film with wide latitude and the normal-luminance view box is recommended because of reduced radiation dose. (author)
8. A LUMINOUS, FAST RISING UV-TRANSIENT DISCOVERED BY ROTSE: A TIDAL DISRUPTION EVENT?
International Nuclear Information System (INIS)
Vinkó, J.; Wheeler, J. C.; Chatzopoulos, E.; Marion, G. H.; Yuan, F.; Akerlof, C.; Quimby, R. M.; Ramirez-Ruiz, E.; Guillochon, J.
2015-01-01
We present follow-up observations of an optical transient (OT) discovered by ROTSE on 2009 January 21. Photometric monitoring was carried out with ROTSE-IIIb in the optical and Swift in the UV up to +70 days after discovery. The light curve showed a fast rise time of ∼10 days followed by a steep decline over the next 60 days, which was much faster than that implied by 56 Ni— 56 Co radioactive decay. The Sloan Digital Sky Survey Data Release 10 database contains a faint, red object at the position of the OT, which appears slightly extended. This and other lines of evidence suggest that the OT is of extragalactic origin, and this faint object is likely the host galaxy. A sequence of optical spectra obtained with the 9.2 m Hobby-Eberly Telescope between +8 and +45 days after discovery revealed a hot, blue continuum with no visible spectral features. A few weak features that appeared after +30 days probably originated from the underlying host. Fitting synthetic templates to the observed spectrum of the host galaxy revealed a redshift of z = 0.19. At this redshift, the peak magnitude of the OT is close to –22.5, similar to the brightest super-luminous supernovae; however, the lack of identifiable spectral features makes the massive stellar death hypothesis less likely. A more plausible explanation appears to be the tidal disruption of a Sun-like star by the central supermassive black hole. We argue that this transient likely belongs to a class of super-Eddington tidal disruption events
9. A New Kind of Blue Hybrid Electroluminescent Device.
Science.gov (United States)
Wang, Junling; Li, Zhuan; Liu, Chunmei
2016-04-01
Bright blue Electroluminescence come from a ITO/BBOT doped silica (6 x 10(-3) M) made by a sol-gel method/Al driven by AC with 500 Hz at different voltages and Gaussian analysis under 55 V showed that blue emission coincidenced with typical triple emission from BBOT. This kind of device take advantage of organics (BBOT) and inorganics (silica). Electroluminescence from a single-layered sandwiched device consisting of blue fluorescent dye 2,5-bis (5-tert-butyl-2-benzoxazolyl) thiophene (BBOT) doped silica made by sol-gel method was investigated. A number of concentrations of hybrid devices were prepared and the maxium concentration was 6 x 10(-3) M. Blue electroluminescent (EL) always occurred above a threshold field 8.57 x 10(5) V/cm (30 V) at alternating voltage at 500 HZ. The luminance of the devices increased with the concentration of doped BBOT, but electroluminescence characteristics were different from a single molecule's photoluminescence properties of triple peaks. When analyzing in detail direct-current electroluminescence devices of pure BBOT, a single peak centered at 2.82 eV appeared with the driven voltage increase, which is similar to the hybrid devices. Comparing Gaussian decomposition date between two kinds of devices, the triple peak characteristic of BBOT was consistent. It is inferred that BBOT contributed EL of the hybrid devices mainly and silica may account for a very small part. Meanwhile the thermal stability of matrix silica was measured by Thermal Gravity-Mass Spectroscopy (TG-MS). There is 12 percent weight loss from room temperature to 1000 °C and silica has about 95% transmittance. So the matric silica played an important role in thermal stability and optical stability for BBOT. In addition, this kind of blue electroluminescence device can take advantages of organic materials BBOT and inorganic materials silica. This is a promising way to enrich EL devices, especially enriching inorganic EL color at a low cost.
10. Efficient fluorescent deep-blue and hybrid white emitting devices based on carbazole/benzimidazole compound
KAUST Repository
Yang, Xiaohui
2011-07-28
We report the synthesis, photophysics, and electrochemical characterization of carbazole/benzimidazole-based compound (Cz-2pbb) and efficient fluorescent deep-blue light emitting devices based on Cz-2pbb with the peak external quantum efficiency of 4.1% and Commission Internationale dÉnclairage coordinates of (0.16, 0.05). Efficient deep-blue emission as well as high triplet state energy of Cz-2pbb enables fabrication of hybrid white organic light emitting diodes with a single emissive layer. Hybrid white emitting devices based on Cz-2pbb show the peak external quantum efficiency exceeding 10% and power efficiency of 14.8 lm/W at a luminance of 500 cd/m2. © 2011 American Chemical Society.
11. Crystalline liquids: the blue phases
Science.gov (United States)
Wright, David C.; Mermin, N. David
1989-04-01
The blue phases of cholesteric liquid crystals are liquids that exhibit orientational order characterized by crystallographic space-group symmetries. We present here a pedagogical introduction to the current understanding of the equilibrium structure of these phases accompanied by a general overview of major experimental results. Using the Ginzburg-Landau free energy appropriate to the system, we first discuss in detail the character and stability of the usual helical phase of cholesterics, showing that for certain parameter ranges the helical phase is unstable to the appearance of one or more blue phases. The two principal models for the blue phases are two limiting cases of the Ginzburg-Landau theory. We explore each limit and conclude with some general considerations of defects in both models and an exact minimization of the free energy in a curved three-dimensional space.
12. Comparison of luminance based metrics in different lighting conditions
DEFF Research Database (Denmark)
Wienold, J.; Kuhn, T.E.; Christoffersen, J.
In this study, we evaluate established and newly developed metrics for predicting glare using data from three different research studies. The evaluation covers two different targets: 1. How well the user’s perception of glare magnitude correlates to the prediction of the glare metrics? 2. How well...... do the glare metrics describe the subjects’ disturbance by glare? We applied Spearman correlations, logistic regressions and an accuracy evaluation, based on an ROC-analysis. The results show that five of the twelve investigated metrics are failing at least one of the statistical tests. The other...... seven metrics CGI, modified DGI, DGP, Ev, average Luminance of the image Lavg, UGP and UGR are passing all statistical tests. DGP, CGI, DGI_mod and UGP have largest AUC and might be slightly more robust. The accuracy of the predictions of afore mentioned seven metrics for the disturbance by glare lies...
13. Clustering of very luminous infrared galaxies and their environment
Science.gov (United States)
Gao, YU
1993-01-01
The IRAS survey reveals a class of ultraluminous infrared (IR) galaxies (ULIRG's) with IR luminosities comparable to the bolometric luminosities of quasars. The nature, origin, and evolution of ULIRG's are attracting more and more attention recently. Since galaxy morphology is certainly a function of environment, morphological observations show that ULIRG's are interacting/merging galaxies, and some ULIRG's might be the dust-enshrouded quasars (S88) or giant ellipticals, the study of ULIRG's environment and large scale clustering effects should be worthwhile. ULIRG's and very luminous IR galaxies have been selected from the 2Jy IRAS redshift survey. Meanwhile, a catalog of IRAS groups of galaxies has been constructed using a percolation-like algorithm. Therefore, whether ULIRG's and/or VLIRG's have a group environment can be checked immediately. Other aspects of the survey are discussed.
14. Progress of OLED devices with high efficiency at high luminance
Science.gov (United States)
Nguyen, Carmen; Ingram, Grayson; Lu, Zhenghong
2014-03-01
Organic light emitting diodes (OLEDs) have progressed significantly over the last two decades. For years, OLEDs have been promoted as the next generation technology for flat panel displays and solid-state lighting due to their potential for high energy efficiency and dynamic range of colors. Although high efficiency can readily be obtained at low brightness levels, a significant decline at high brightness is commonly observed. In this report, we will review various strategies for achieving highly efficient phosphorescent OLED devices at high luminance. Specifically, we will provide details regarding the performance and general working principles behind each strategy. We will conclude by looking at how some of these strategies can be combined to produce high efficiency white OLEDs at high brightness.
15. Shock waves in luminous early-type stars
International Nuclear Information System (INIS)
Castor, J.I.
1986-01-01
Shock waves that occur in stellar atmospheres have their origin in some hydrodynamic instability of the atmosphere itself or of the stellar interior. In luminous early-type stars these two possibilities are represented by shocks due to an unstable radiatively-accelerated wind, and to shocks generated by the non-radial pulsations known to be present in many or most OB stars. This review is concerned with the structure and development of the shocks in these two cases, and especially with the mass loss that may be due specifically to the shocks. Pulsation-produced shocks are found to be very unfavorable for causing mass loss, owing to the great radiation efficiency that allows them to remain isothermal. The situation regarding radiatively-driven shocks remains unclear, awaiting detailed hydrodynamics calculations. 20 refs., 2 figs
16. Origin of faint blue stars
International Nuclear Information System (INIS)
Tutukov, A.; Iungelson, L.
1987-01-01
The origin of field faint blue stars that are placed in the HR diagram to the left of the main sequence is discussed. These include degenerate dwarfs and O and B subdwarfs. Degenerate dwarfs belong to two main populations with helium and carbon-oxygen cores. The majority of the hot subdwarfs most possibly are helium nondegenerate stars that are produced by mass exchange close binaries of moderate mass cores (3-15 solar masses). The theoretical estimates of the numbers of faint blue stars of different types brighter than certain stellar magnitudes agree with star counts based on the Palomar Green Survey. 28 references
17. Adaptive color halftoning for minimum perceived error using the blue noise mask
Science.gov (United States)
Yu, Qing; Parker, Kevin J.
1997-04-01
Color halftoning using a conventional screen requires careful selection of screen angles to avoid Moire patterns. An obvious advantage of halftoning using a blue noise mask (BNM) is that there are no conventional screen angle or Moire patterns produced. However, a simple strategy of employing the same BNM on all color planes is unacceptable in case where a small registration error can cause objectionable color shifts. In a previous paper by Yao and Parker, strategies were presented for shifting or inverting the BNM as well as using mutually exclusive BNMs for different color planes. In this paper, the above schemes will be studied in CIE-LAB color space in terms of root mean square error and variance for luminance channel and chrominance channel respectively. We will demonstrate that the dot-on-dot scheme results in minimum chrominance error, but maximum luminance error and the 4-mask scheme results in minimum luminance error but maximum chrominance error, while the shift scheme falls in between. Based on this study, we proposed a new adaptive color halftoning algorithm that takes colorimetric color reproduction into account by applying 2-mutually exclusive BNMs on two different color planes and applying an adaptive scheme on other planes to reduce color error. We will show that by having one adaptive color channel, we obtain increased flexibility to manipulate the output so as to reduce colorimetric error while permitting customization to specific printing hardware.
18. Effect of Stepwise Doping on Lifetime and Efficiency of Blue and White Phosphorescent Organic Light Emitting Diodes.
Science.gov (United States)
Lee, Song Eun; Lee, Ho Won; Lee, Seok Jae; Koo, Ja-ryong; Lee, Dong Hyung; Yang, Hyung Jin; Kim, Hye Jeong; Yoon, Seung Soo; Kim, Young Kwan
2015-02-01
We investigated a light emission mechanism of blue phosphorescent organic light emitting diodes (PHOLEDs), using a stepwise doping profile of 2, 8, and 14 wt.% within the emitting layer (EML). We fabricated several blue PHOLEDs with phosphorescent blue emitter iridium(III) bis[(4,6-difluorophenyl)-pyridinato-N,C2]picolinate doped in N,N'-dicarbazolyl-3,5-benzene as a p-type host material. A blue PHOLED with the highest doping concentration as part of the EML close to an electron transporting layer showed a maximum luminous efficiency of 20.74 cd/A, and a maximum external quantum efficiency of 10.52%. This can be explained by effective electron injection through a highly doped EML side. Additionally, a white OLED based on the doping profile was fabricated with two thin red EMLs within a blue EML maintaining a thickness of 30 nm for the entire EML. Keywords: Blue Phosphorescent Organic Light Emitting Diodes, Stepwise Doping Structure, Charge Trapping Effect.
19. 10 CFR 30.19 - Self-luminous products containing tritium, krypton-85, or promethium-147.
Science.gov (United States)
2010-01-01
... 10 Energy 1 2010-01-01 2010-01-01 false Self-luminous products containing tritium, krypton-85, or..., krypton-85, or promethium-147. (a) Except for persons who manufacture, process, produce, or initially transfer for sale or distribution self-luminous products containing tritium, krypton-85, or promethium-147...
20. Highly efficient blue OLEDs based on diphenylaminofluorenylstyrenes end-capped with heterocyclic aromatics
Energy Technology Data Exchange (ETDEWEB)
Oh, Suhyun [Department of Chemistry, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Lee, Kum Hee; Kim, Young Kwan [Department of Information Display, Hongik University, Seoul 121-791 (Korea, Republic of); Yoon, Seung Soo, E-mail: ssyoon@skku.edu [Department of Chemistry, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)
2012-10-15
In this paper, we have designed four diphenylaminofluorenylstyrene derivatives end-capped with heterocyclic aromatic groups, such as 9-phenylcabazole, 4-dibenzofuran, 2-benzoxazole, 2-quinoxaline, respectively. These materials showed blue to red fluorescence with maximum emission wavelengths of 476–611 nm, respectively, which were dependent on the structural and electronic nature of end-capping groups. To explore the electroluminescent properties of these materials, multilayer OLEDs were fabricated in the following sequence: ITO/DNTPD (40 nm)/NPB (20 nm)/2% doped in MADN (20 nm)/Alq{sub 3} (40 nm)/Liq. (1 nm)/Al. Among those, a device exhibited a highly efficient blue emission with the maximum luminance of 14,480 cd/m{sup 2} at 9 V, the luminous efficiency of 5.38 cd/A at 20 mA/cm{sup 2}, power efficiency of 2.77 lm/W at 20 mA/cm{sup 2}, and CIE{sub x,y} coordinates of (0.147, 0.152) at 8 V, respectively.
1. Efficient white organic light-emitting devices based on blue, orange, red phosphorescent dyes
International Nuclear Information System (INIS)
Chen Ping; Duan Yu; Xie Wenfa; Zhao Yi; Hou Jingying; Liu Shiyong; Zhang Liying; Li Bin
2009-01-01
We demonstrate efficient white organic light-emitting devices (WOLEDs) based on an orange phosphorescent iridium complex bis(2-(2-fluorphenyl)-1,3-benzothiozolato-N, C 2' )iridium(acetylacetonate) in combination with blue phosphorescent dye bis[(4, 6-difluorophenyl)-pyridinato-N,C 2 )](picolinato) Ir(III) and red phosphorescent dye bis[1-(phenyl)isoquinoline] iridium (III) acetylanetonate. By introducing a thin layer of 4, 7-diphenyl-1,10-phenanthroline between blue and red emission layers, the diffusion of excitons is confined and white light can be obtained. WOLEDs with the interlayer all have a higher colour rendering index (>82) than the device without it (76). One device has the maximum current efficiency of 17.6 cd A -1 and a maximum luminance of 39 050 cd m -2 . The power efficiency is 8.7 lm W -1 at 100 cd m -2 . Furthermore, the device has good colour stability and the CIE coordinates just change from (0.394, 0.425) to (0.390, 0.426) with the luminance increasing from 630 to 4200 cd m -2 .
2. Seeing the Unseen: MIR Spectroscopic Constraints on Quasar Big Blue Bumps
Science.gov (United States)
Gallagher, Sarah; Hines, Dean; Leighly, Karen; Ogle, Patrick; Richards, Gordon
2008-03-01
The IRS on Spitzer offers an exciting opportunity for detailed, mid-infrared spectroscopy of z~2 quasars for the first time. This epoch, sampling the peak of the quasar luminosity evolution, is particularly important for understanding the nature of quasar activity in the most massive galaxies. We aim to use this powerful tool to constrain the shape and power of the far-ultraviolet through soft-X-ray ionizing continuum of luminous quasars. Though these so-called big blue bumps' dominate the power of quasar spectral energy distributions, they are largely unobservable as a result of hydrogen opacity in the Universe. However, we can determine the properties of the big blue bump by studying emission lines from ions in the coronal line region that emit in the mid-infrared and are created by those same energetic and elusive photons. We propose deep, high quality IRS observations of 5 luminous quasars with a range of HeII emission properties to investigate the mid-infrared spectral region in depth and constrain the shape of the ionizing continuum in each quasar. In addition, these high S/N spectra will provide templates for interpreting lower resolution, lower S/N IRS spectra.
3. Independence and interaction of luminance and chromatic contributions to spatial hyperacuity performance.
Science.gov (United States)
Cooper, Bonnie; Lee, Barry B
2014-04-01
Here we test interactions of luminance and chromatic input to spatial hyperacuity mechanisms. First, we tested alignment of luminance and chromatic gratings matched or mismatched in contrast polarity or grating type. Thresholds with matched gratings were low while all mismatched pairs were elevated. Second, we determined alignment acuity as a function of luminance or chromatic contrast alone or in the presence of constant contrast components of the other type. For in-phase components, performance followed the envelope of the more sensitive mechanism. However, polarity reversals revealed an asymmetric effect for luminance and chromatic conditions, which suggested that luminance can override chromatic mechanisms in hyperacuity; we interpret these findings in the context of spatial mechanisms.
4. Blue Ocean vs. Five Forces
NARCIS (Netherlands)
A.E. Burke (Andrew); A.J. van Stel (André); A.R. Thurik (Roy)
2010-01-01
textabstractThe article reports on the authors' research in the Netherlands which focused on a profit model in Dutch retail stores and a so-called blue-ocean approach which requires a new market that attracts consumers and increases profits. Topics include the competitive strategy approach to
5. One-dimensional numerical modeling of Blue Jet and its impact on stratospheric chemistry
Science.gov (United States)
Duruisseau, F.; Thiéblemont, R.; Huret, N.
2011-12-01
In the stratosphere the ozone layer is very sensitive to the NOx abundance. The ionisation of N2 and O2 molecules by TLE's (Transient Luminous Events) is a source of NOx which is currently not well quantified and could act as a loss of ozone. In this study a one dimensional explicit parameterization of a Blue-Jet propagation based on that proposed by Raizer et al. (2006 and 2007) has been developed. This parameterization considers Blue-Jet as a streamer initiated by a bidirectional leader discharge, emerging from the anvil and sustained by moderate cloud charge. The streamer growth varies with the electrical field induced by initial cloud charge and the initial altitude. This electrical parameterization and the chemical mechanisms associated with the discharge have been implemented into a detailed chemical model of stratospheric ozone including evolution of nitrogen, chlorine and bromine species. We will present several tests performed to validate the electrical code and evaluate the propagation velocity and the maximum altitude attains by the blue jet as a function of electrical parameters. The results obtained giving the spatiotemporal evolution of the electron density are then used to initiate the specific chemistry associated with the Blue Jet. Preliminary results on the impact of such discharge on the ozone content and the whole stratospheric system will be presented.
6. Recombination zone in white organic light emitting diodes with blue and orange emitting layers
Science.gov (United States)
Tsuboi, Taiju; Kishimoto, Tadashi; Wako, Kazuhiro; Matsuda, Kuniharu; Iguchi, Hirofumi
2012-10-01
White fluorescent OLED devices with a 10 nm thick blue-emitting layer and a 31 nm thick orange-emitting layer have been fabricated, where the blue-emitting layer is stacked on a hole transport layer. An interlayer was inserted between the two emitting layers. The thickness of the interlayer was changed among 0.3, 0.4, and 1.0 nm. White emission with CIE coordinates close to (0.33, 0.33) was observed from all the OLEDs. OLED with 0.3 nm thick interlayer gives the highest maximum luminous efficiency (11 cd/A), power efficiency (9 lm/W), and external quantum efficiency (5.02%). The external quantum efficiency becomes low with increasing the interlayer thickness from 0 nm to 1.0 nm. When the location of the blue- and orange-emitting layers is reversed, white emission was not obtained because of too weak blue emission. It is suggested that the electron-hole recombination zone decreases nearly exponentially with a distance from the hole transport layer.
7. HOT DUST OBSCURED GALAXIES WITH EXCESS BLUE LIGHT: DUAL AGN OR SINGLE AGN UNDER EXTREME CONDITIONS?
Energy Technology Data Exchange (ETDEWEB)
Assef, R. J.; Diaz-Santos, T. [Núcleo de Astronomía de la Facultad de Ingeniería, Universidad Diego Portales, Av. Ejército Libertador 441, Santiago (Chile); Walton, D. J.; Brightman, M. [Space Radiation Laboratory, California Institute of Technology, Pasadena, CA 91125 (United States); Stern, D.; Eisenhardt, P. R. M.; Tsai, C.-W. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Mail Stop 169-236, Pasadena, CA 91109 (United States); Alexander, D. [Department of Physics, Durham University, Durham DH1 3LE (United Kingdom); Bauer, F. [Departamento de Astronomía y Astrofísica, Pontificia Universidad Católica de Chile, Casilla 306, Santiago 22 (Chile); Blain, A. W. [Physics and Astronomy, University of Leicester, 1 University Road, Leicester LE1 7RH (United Kingdom); Finkelstein, S. L. [The University of Texas at Austin, 2515 Speedway, Stop C1400, Austin, TX 78712 (United States); Hickox, R. C. [Department of Physics and Astronomy, Dartmouth College, 6127 Wilder Laboratory, Hanover, NH 03755 (United States); Wu, J. W., E-mail: roberto.assef@mail.udp.cl [UCLA Astronomy, P.O. Box 951547, Los Angeles, CA 90095-1547 (United States)
2016-03-10
Hot dust-obscured galaxies (Hot DOGs) are a population of hyper-luminous infrared galaxies identified by the Wide-field Infrared Survey Explorer (WISE) mission from their very red mid-IR colors, and characterized by hot dust temperatures (T > 60 K). Several studies have shown clear evidence that the IR emission in these objects is powered by a highly dust-obscured active galactic nucleus (AGN) that shows close to Compton-thick absorption at X-ray wavelengths. Thanks to the high AGN obscuration, the host galaxy is easily observable, and has UV/optical colors usually consistent with those of a normal galaxy. Here we discuss a sub-population of eight Hot DOGs that show enhanced rest-frame UV/optical emission. We discuss three scenarios that might explain the excess UV emission: (i) unobscured light leaked from the AGN by reflection over the dust or by partial coverage of the accretion disk; (ii) a second unobscured AGN in the system; or (iii) a luminous young starburst. X-ray observations can help discriminate between these scenarios. We study in detail the blue excess Hot DOG WISE J020446.13–050640.8, which was serendipitously observed by Chandra/ACIS-I for 174.5 ks. The X-ray spectrum is consistent with a single, hyper-luminous, highly absorbed AGN, and is strongly inconsistent with the presence of a secondary unobscured AGN. Based on this, we argue that the excess blue emission in this object is most likely either due to reflection or a co-eval starburst. We favor the reflection scenario as the unobscured star formation rate needed to power the UV/optical emission would be ≳1000 M{sub ⊙} yr{sup −1}. Deep polarimetry observations could confirm the reflection hypothesis.
8. HOT DUST OBSCURED GALAXIES WITH EXCESS BLUE LIGHT: DUAL AGN OR SINGLE AGN UNDER EXTREME CONDITIONS?
International Nuclear Information System (INIS)
Assef, R. J.; Diaz-Santos, T.; Walton, D. J.; Brightman, M.; Stern, D.; Eisenhardt, P. R. M.; Tsai, C.-W.; Alexander, D.; Bauer, F.; Blain, A. W.; Finkelstein, S. L.; Hickox, R. C.; Wu, J. W.
2016-01-01
Hot dust-obscured galaxies (Hot DOGs) are a population of hyper-luminous infrared galaxies identified by the Wide-field Infrared Survey Explorer (WISE) mission from their very red mid-IR colors, and characterized by hot dust temperatures (T > 60 K). Several studies have shown clear evidence that the IR emission in these objects is powered by a highly dust-obscured active galactic nucleus (AGN) that shows close to Compton-thick absorption at X-ray wavelengths. Thanks to the high AGN obscuration, the host galaxy is easily observable, and has UV/optical colors usually consistent with those of a normal galaxy. Here we discuss a sub-population of eight Hot DOGs that show enhanced rest-frame UV/optical emission. We discuss three scenarios that might explain the excess UV emission: (i) unobscured light leaked from the AGN by reflection over the dust or by partial coverage of the accretion disk; (ii) a second unobscured AGN in the system; or (iii) a luminous young starburst. X-ray observations can help discriminate between these scenarios. We study in detail the blue excess Hot DOG WISE J020446.13–050640.8, which was serendipitously observed by Chandra/ACIS-I for 174.5 ks. The X-ray spectrum is consistent with a single, hyper-luminous, highly absorbed AGN, and is strongly inconsistent with the presence of a secondary unobscured AGN. Based on this, we argue that the excess blue emission in this object is most likely either due to reflection or a co-eval starburst. We favor the reflection scenario as the unobscured star formation rate needed to power the UV/optical emission would be ≳1000 M ⊙ yr −1 . Deep polarimetry observations could confirm the reflection hypothesis
9. Modelling the effects of environmental conditions on the acoustic occurrence and behaviour of Antarctic blue whales.
Directory of Open Access Journals (Sweden)
Fannie W Shabangu
Full Text Available Harvested to perilously low numbers by commercial whaling during the past century, the large scale response of Antarctic blue whales Balaenoptera musculus intermedia to environmental variability is poorly understood. This study uses acoustic data collected from 586 sonobuoys deployed in the austral summers of 1997 through 2009, south of 38°S, coupled with visual observations of blue whales during the IWC SOWER line-transect surveys. The characteristic Z-call and D-call of Antarctic blue whales were detected using an automated detection template and visual verification method. Using a random forest model, we showed the environmental preferences pattern, spatial occurrence and acoustic behaviour of Antarctic blue whales. Distance to the southern boundary of the Antarctic Circumpolar Current (SBACC, latitude and distance from the nearest Antarctic shores were the main geographic predictors of blue whale call occurrence. Satellite-derived sea surface height, sea surface temperature, and productivity (chlorophyll-a were the most important environmental predictors of blue whale call occurrence. Call rates of D-calls were strongly predicted by the location of the SBACC, latitude and visually detected number of whales in an area while call rates of Z-call were predicted by the SBACC, latitude and longitude. Satellite-derived sea surface height, wind stress, wind direction, water depth, sea surface temperatures, chlorophyll-a and wind speed were important environmental predictors of blue whale call rates in the Southern Ocean. Blue whale call occurrence and call rates varied significantly in response to inter-annual and long term variability of those environmental predictors. Our results identify the response of Antarctic blue whales to inter-annual variability in environmental conditions and highlighted potential suitable habitats for this population. Such emerging knowledge about the acoustic behaviour, environmental and habitat preferences of
10. Modelling the effects of environmental conditions on the acoustic occurrence and behaviour of Antarctic blue whales.
Science.gov (United States)
Shabangu, Fannie W; Yemane, Dawit; Stafford, Kathleen M; Ensor, Paul; Findlay, Ken P
2017-01-01
Harvested to perilously low numbers by commercial whaling during the past century, the large scale response of Antarctic blue whales Balaenoptera musculus intermedia to environmental variability is poorly understood. This study uses acoustic data collected from 586 sonobuoys deployed in the austral summers of 1997 through 2009, south of 38°S, coupled with visual observations of blue whales during the IWC SOWER line-transect surveys. The characteristic Z-call and D-call of Antarctic blue whales were detected using an automated detection template and visual verification method. Using a random forest model, we showed the environmental preferences pattern, spatial occurrence and acoustic behaviour of Antarctic blue whales. Distance to the southern boundary of the Antarctic Circumpolar Current (SBACC), latitude and distance from the nearest Antarctic shores were the main geographic predictors of blue whale call occurrence. Satellite-derived sea surface height, sea surface temperature, and productivity (chlorophyll-a) were the most important environmental predictors of blue whale call occurrence. Call rates of D-calls were strongly predicted by the location of the SBACC, latitude and visually detected number of whales in an area while call rates of Z-call were predicted by the SBACC, latitude and longitude. Satellite-derived sea surface height, wind stress, wind direction, water depth, sea surface temperatures, chlorophyll-a and wind speed were important environmental predictors of blue whale call rates in the Southern Ocean. Blue whale call occurrence and call rates varied significantly in response to inter-annual and long term variability of those environmental predictors. Our results identify the response of Antarctic blue whales to inter-annual variability in environmental conditions and highlighted potential suitable habitats for this population. Such emerging knowledge about the acoustic behaviour, environmental and habitat preferences of Antarctic blue whales is
11. A comparison of Ki-67 counting methods in luminal Breast Cancer: The Average Method vs. the Hot Spot Method.
Directory of Open Access Journals (Sweden)
Min Hye Jang
Full Text Available In spite of the usefulness of the Ki-67 labeling index (LI as a prognostic and predictive marker in breast cancer, its clinical application remains limited due to variability in its measurement and the absence of a standard method of interpretation. This study was designed to compare the two methods of assessing Ki-67 LI: the average method vs. the hot spot method and thus to determine which method is more appropriate in predicting prognosis of luminal/HER2-negative breast cancers. Ki-67 LIs were calculated by direct counting of three representative areas of 493 luminal/HER2-negative breast cancers using the two methods. We calculated the differences in the Ki-67 LIs (ΔKi-67 between the two methods and the ratio of the Ki-67 LIs (H/A ratio of the two methods. In addition, we compared the performance of the Ki-67 LIs obtained by the two methods as prognostic markers. ΔKi-67 ranged from 0.01% to 33.3% and the H/A ratio ranged from 1.0 to 2.6. Based on the receiver operating characteristic curve method, the predictive powers of the KI-67 LI measured by the two methods were similar (Area under curve: hot spot method, 0.711; average method, 0.700. In multivariate analysis, high Ki-67 LI based on either method was an independent poor prognostic factor, along with high T stage and node metastasis. However, in repeated counts, the hot spot method did not consistently classify tumors into high vs. low Ki-67 LI groups. In conclusion, both the average and hot spot method of evaluating Ki-67 LI have good predictive performances for tumor recurrence in luminal/HER2-negative breast cancers. However, we recommend using the average method for the present because of its greater reproducibility.
12. A comparison of Ki-67 counting methods in luminal Breast Cancer: The Average Method vs. the Hot Spot Method.
Science.gov (United States)
Jang, Min Hye; Kim, Hyun Jung; Chung, Yul Ri; Lee, Yangkyu; Park, So Yeon
2017-01-01
In spite of the usefulness of the Ki-67 labeling index (LI) as a prognostic and predictive marker in breast cancer, its clinical application remains limited due to variability in its measurement and the absence of a standard method of interpretation. This study was designed to compare the two methods of assessing Ki-67 LI: the average method vs. the hot spot method and thus to determine which method is more appropriate in predicting prognosis of luminal/HER2-negative breast cancers. Ki-67 LIs were calculated by direct counting of three representative areas of 493 luminal/HER2-negative breast cancers using the two methods. We calculated the differences in the Ki-67 LIs (ΔKi-67) between the two methods and the ratio of the Ki-67 LIs (H/A ratio) of the two methods. In addition, we compared the performance of the Ki-67 LIs obtained by the two methods as prognostic markers. ΔKi-67 ranged from 0.01% to 33.3% and the H/A ratio ranged from 1.0 to 2.6. Based on the receiver operating characteristic curve method, the predictive powers of the KI-67 LI measured by the two methods were similar (Area under curve: hot spot method, 0.711; average method, 0.700). In multivariate analysis, high Ki-67 LI based on either method was an independent poor prognostic factor, along with high T stage and node metastasis. However, in repeated counts, the hot spot method did not consistently classify tumors into high vs. low Ki-67 LI groups. In conclusion, both the average and hot spot method of evaluating Ki-67 LI have good predictive performances for tumor recurrence in luminal/HER2-negative breast cancers. However, we recommend using the average method for the present because of its greater reproducibility.
13. Organic light-emitting diodes with direct contact-printed red, green, blue, and white light-emitting layers
Science.gov (United States)
Chen, Sun-Zen; Peng, Shiang-Hau; Ting, Tzu-Yu; Wu, Po-Shien; Lin, Chun-Hao; Chang, Chin-Yeh; Shyue, Jing-Jong; Jou, Jwo-Huei
2012-10-01
We demonstrate the feasibility of using direct contact-printing in the fabrication of monochromatic and polychromatic organic light-emitting diodes (OLEDs). Bright devices with red, green, blue, and white contact-printed light-emitting layers with a respective maximum luminance of 29 000, 29 000, 4000, and 18 000 cd/m2 were obtained with sound film integrity by blending a polymeric host into a molecular host. For the red OLED as example, the maximum luminance was decreased from 29 000 to 5000 cd/m2 as only the polymeric host was used, or decreased to 7000 cd/m2 as only the molecular host was used. The markedly improved device performance achieved in the devices with blended hosts may be attributed to the employed polymeric host that contributed a good film-forming character, and the molecular host that contributed a good electroluminescence character.
14. Degradation of phosphorescent blue organic light-emitting diodes (OLED); Degradation der phosphoreszenten blauen organischen Leuchtdioden
Energy Technology Data Exchange (ETDEWEB)
Chiu, Chien-Shu
2011-07-01
15. Blue and white phosphorescent organic light emitting diode performance improvement by confining electrons and holes inside double emitting layers
Energy Technology Data Exchange (ETDEWEB)
Tsai, Yu-Sheng; Hong, Lin-Ann; Juang, Fuh-Shyang; Chen, Cheng-Yin
2014-09-15
In this research, complex emitting layers (EML) were fabricated using TCTA doping hole-transport material in the front half of a bipolar 26DCzPPy as well as PPT doping electron-transport material in the back half of 26DCzPPy. Blue dopant FIrpic was also mixed inside the complex emitting layer to produce a highly efficient blue phosphorescent organic light emitting diode (OLED). The hole and electron injection and carrier recombination rate were effectively increased. The fabricated complex emitting layers exhibited current efficiency of 42 cd/A and power efficiency of 30 lm/W when the luminance was 1000 cd/m{sup 2}, driving voltage was 4.4 V, and current density was 2.4 mA/cm{sup 2}. A white OLED component was then manufactured by doping red dopant [Os(bpftz){sub 2}(PPh{sub 2}Me){sub 2}] (Os) in proper locations. When the Os dopant was doped in between the complex emitting layers, excitons were effectively confined within, increasing the recombination rate and therefore reducing the color shift. The resulting Commission Internationale de L’Eclairage (CIE) coordinates shifted from 4 to 10 V is (Δx=−0.04, Δy=+0.01). The component had a current efficiency of 35.7 cd/A, a power efficiency of 24 lm/W, driving voltage of 4.6 V and a CIE{sub x,y} of (0.31,0.35) at a luminance of 1000 cd/m{sup 2}, with a maximum luminance of 15,600 cd/m{sup 2} at 10 V. Attaching an outcoupling enhancement film was applied to increase the luminance efficiency to 30 lm/W. - Highlights: • Used the complex double emitting layers. • Respectively doped hole and electron transport material in the bipolar host. • Electrons and holes are effectively confined within EMLs to produce excitons.
16. Blue and white phosphorescent organic light emitting diode performance improvement by confining electrons and holes inside double emitting layers
International Nuclear Information System (INIS)
Tsai, Yu-Sheng; Hong, Lin-Ann; Juang, Fuh-Shyang; Chen, Cheng-Yin
2014-01-01
In this research, complex emitting layers (EML) were fabricated using TCTA doping hole-transport material in the front half of a bipolar 26DCzPPy as well as PPT doping electron-transport material in the back half of 26DCzPPy. Blue dopant FIrpic was also mixed inside the complex emitting layer to produce a highly efficient blue phosphorescent organic light emitting diode (OLED). The hole and electron injection and carrier recombination rate were effectively increased. The fabricated complex emitting layers exhibited current efficiency of 42 cd/A and power efficiency of 30 lm/W when the luminance was 1000 cd/m 2 , driving voltage was 4.4 V, and current density was 2.4 mA/cm 2 . A white OLED component was then manufactured by doping red dopant [Os(bpftz) 2 (PPh 2 Me) 2 ] (Os) in proper locations. When the Os dopant was doped in between the complex emitting layers, excitons were effectively confined within, increasing the recombination rate and therefore reducing the color shift. The resulting Commission Internationale de L’Eclairage (CIE) coordinates shifted from 4 to 10 V is (Δx=−0.04, Δy=+0.01). The component had a current efficiency of 35.7 cd/A, a power efficiency of 24 lm/W, driving voltage of 4.6 V and a CIE x,y of (0.31,0.35) at a luminance of 1000 cd/m 2 , with a maximum luminance of 15,600 cd/m 2 at 10 V. Attaching an outcoupling enhancement film was applied to increase the luminance efficiency to 30 lm/W. - Highlights: • Used the complex double emitting layers. • Respectively doped hole and electron transport material in the bipolar host. • Electrons and holes are effectively confined within EMLs to produce excitons
17. 75 FR 65525 - Anthem Blue Cross Blue Shield, Claim Management Services, Inc. Operations, a Division of...
Science.gov (United States)
2010-10-25
... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-74,327] Anthem Blue Cross Blue Shield, Claim Management Services, Inc. Operations, a Division of Wellpoint, Inc., Green Bay, WI; Notice... former workers of Anthem Blue Cross Blue Shield, Claim Management Services, Inc. Operations, a Division...
18. Month-hour distributions of zenith luminance and diffuse illuminance in Madrid
International Nuclear Information System (INIS)
Soler, Alfonso; Gopinathan, Kannam K.; Robledo, Luis; Ruiz, Enrique
2004-01-01
Month-hour equal mean zenith luminance contours are obtained from one year of data of zenith luminance measurements for cloudless, overcast and partly cloudy skies and also when the combined data for all sky types are considered. For many hours in different months, the overcast sky luminance values are roughly about three times the cloudless sky luminance values and one and a half times the partly cloudy sky values. The dependence of month-hour equal mean zenith luminance contours on the ratio of global to extraterrestrial illuminance on a horizontal surface is also given. From equal mean zenith luminance contours, the approximate values of the mean zenith luminance for different sky conditions and different hours and months of the year can be easily obtained. Month-hour equal mean diffuse illuminance contours are obtained from diffuse illuminance measurements performed during the period 1992-1998. The dependence on solar altitude of the monthly average hourly values of diffuse illuminance is given and compared to the corresponding one obtained from data for Bet Dagan (Israel)
19. Mixing of Chromatic and Luminance Retinal Signals in Primate Area V1.
Science.gov (United States)
Li, Xiaobing; Chen, Yao; Lashgari, Reza; Bereshpolova, Yulia; Swadlow, Harvey A; Lee, Barry B; Alonso, Jose Manuel
2015-07-01
Vision emerges from activation of chromatic and achromatic retinal channels whose interaction in visual cortex is still poorly understood. To investigate this interaction, we recorded neuronal activity from retinal ganglion cells and V1 cortical cells in macaques and measured their visual responses to grating stimuli that had either luminance contrast (luminance grating), chromatic contrast (chromatic grating), or a combination of the two (compound grating). As with parvocellular or koniocellular retinal ganglion cells, some V1 cells responded mostly to the chromatic contrast of the compound grating. As with magnocellular retinal ganglion cells, other V1 cells responded mostly to the luminance contrast and generated a frequency-doubled response to equiluminant chromatic gratings. Unlike magnocellular and parvocellular retinal ganglion cells, V1 cells formed a unimodal distribution for luminance/color preference with a 2- to 4-fold bias toward luminance. V1 cells associated with positive local field potentials in deep layers showed the strongest combined responses to color and luminance and, as a population, V1 cells encoded a diverse combination of luminance/color edges that matched edge distributions of natural scenes. Taken together, these results suggest that the primary visual cortex combines magnocellular and parvocellular retinal inputs to increase cortical receptive field diversity and to optimize visual processing of our natural environment. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.
20. Luminance and chromatic contributions to a hyperacuity task: isolation by contrast polarity and target separation.
Science.gov (United States)
Sun, Hao; Cooper, Bonnie; Lee, Barry B
2012-03-01
Vernier thresholds are known to be elevated when a target pair has opposite contrast polarity. Polarity reversal is used to assess the role of luminance and chromatic pathways in hyperacuity performance. Psychophysical hyperacuity thresholds were measured for pairs of gratings of various combinations of luminance (Lum) and chromatic (Chr) contrast polarities, at different ratios of luminance to chromatic contrast. With two red-green gratings of matched luminance and chromatic polarity (+Lum+Chr), there was an elevation of threshold at isoluminance. When both luminance and chromatic polarity were mismatched (-Lum-Chr), thresholds were substantially elevated under all conditions. With the same luminance contrast polarity and opposite chromatic polarity (+Lum-Chr) thresholds were only elevated close to isoluminance; in the reverse condition (-Lum+Chr), thresholds were elevated as in the -Lum-Chr condition except close to equiluminance. Similar data were obtained for gratings isolating the short-wavelength cone mechanism. Further psychophysical measurements assessed the role of target separation with matched or mismatched contrast polarity; similar results were found for luminance and chromatic gratings. Comparison physiological data were collected from parafoveal ganglion cells of the macaque retina. Positional precision of ganglion cell signals was assessed under conditions related to the psychophysical measurements. On the basis of these combined observations, it is argued that both magnocellular, parvocellular, and koniocellular pathways have access to cortical positional mechanisms associated with vernier acuity. Copyright © 2012 Elsevier Ltd. All rights reserved.
1. NCOA5 is correlated with progression and prognosis in luminal breast cancer
International Nuclear Information System (INIS)
Ye, Xiao-He; Huang, Du-Ping; Luo, Rong-Cheng
2017-01-01
Nuclear receptor coactivator 5 (NCOA5) is known to modulate ERα-mediated transcription and has been found to be involved in the progression of several malignancies. However, the potential correlation between NCOA5 and clinical outcome in patients with luminal breast cancer remains unknown. In the present study, we demonstrated that NCOA5 was significantly up-regulated in luminal breast cancer tissues compared with adjacent non-cancerous tissues both in validated cohort and TCGA cohort. Moreover, Kaplan-Meier analysis indicated that patients with high NOCA5 expression had significantly lower overall survival (P = 0.021). Cox regression analysis indicated that the high NOCA5 expression was independent high risk factor as well as old age (>60) and HER-2 expression (P = 0.039; P = 0.003; P = 0.005; respectively). This study provides new insights and evidences that NOCA5 over-expression was significantly correlated with progression and prognosis in luminal breast cancer. However, the precise cellular mechanisms for NOCA5 in luminal breast cancer need to be further explored. - Highlights: • NCOA5 is significantly over-expressed in human luminal breast cancer tissues. • NOCA5 was involved in the progression of luminal breast cancer. • NCOA5 can predict the progression of luminal breast cancer.
2. Preliminary analysis on faint luminous lightning events recorded by multiple high speed cameras
Science.gov (United States)
Alves, J.; Saraiva, A. V.; Pinto, O.; Campos, L. Z.; Antunes, L.; Luz, E. S.; Medeiros, C.; Buzato, T. S.
2013-12-01
The objective of this work is the study of some faint luminous events produced by lightning flashes that were recorded simultaneously by multiple high-speed cameras during the previous RAMMER (Automated Multi-camera Network for Monitoring and Study of Lightning) campaigns. The RAMMER network is composed by three fixed cameras and one mobile color camera separated by, in average, distances of 13 kilometers. They were located in the Paraiba Valley (in the cities of São José dos Campos and Caçapava), SP, Brazil, arranged in a quadrilateral shape, centered in São José dos Campos region. This configuration allowed RAMMER to see a thunderstorm from different angles, registering the same lightning flashes simultaneously by multiple cameras. Each RAMMER sensor is composed by a triggering system and a Phantom high-speed camera version 9.1, which is set to operate at a frame rate of 2,500 frames per second with a lens Nikkor (model AF-S DX 18-55 mm 1:3.5 - 5.6 G in the stationary sensors, and a lens model AF-S ED 24 mm - 1:1.4 in the mobile sensor). All videos were GPS (Global Positioning System) time stamped. For this work we used a data set collected in four RAMMER manual operation days in the campaign of 2012 and 2013. On Feb. 18th the data set is composed by 15 flashes recorded by two cameras and 4 flashes recorded by three cameras. On Feb. 19th a total of 5 flashes was registered by two cameras and 1 flash registered by three cameras. On Feb. 22th we obtained 4 flashes registered by two cameras. Finally, in March 6th two cameras recorded 2 flashes. The analysis in this study proposes an evaluation methodology for faint luminous lightning events, such as continuing current. Problems in the temporal measurement of the continuing current can generate some imprecisions during the optical analysis, therefore this work aim to evaluate the effects of distance in this parameter with this preliminary data set. In the cases that include the color camera we analyzed the RGB
3. Influence of Al{sub 2}O{sub 3} reflective layer under phosphor layer on luminance and luminous efficiency characteristics in alternating-current plasma display panel
Energy Technology Data Exchange (ETDEWEB)
Park, Choon-Sang [School of Electronics Engineering, College of IT Engineering, Kyungpook National University, Daegu (Korea, Republic of); Tae, Heung-Sik, E-mail: hstae@ee.knu.ac.kr [School of Electronics Engineering, College of IT Engineering, Kyungpook National University, Daegu (Korea, Republic of); Jung, Eun Young [Core Technology Lab., Corporate R and D Center, Samsung SDI Company Ltd., Cheonan (Korea, Republic of)
2013-11-29
This paper examines the optical and discharge characteristics of alternating-current plasma display panel when adopting the Al{sub 2}O{sub 3} reflective layer. The Al{sub 2}O{sub 3} reflective layer is deposited under the phosphor layer by using the screen-printing method. The resulting changes in the optical and discharge characteristics, including the power consumption, color temperature, luminance, luminous efficiency, scanning electron microscopy image, and reflectance, are then compared for both cases with and without Al{sub 2}O{sub 3} reflective layer. As a result of optimizing the thicknesses between the Al{sub 2}O{sub 3} and phosphor layers, the luminance and luminous efficiency are improved by about 17% and 7%, respectively. - Highlights: • We examine characteristics of plasma display panel when adopting reflective layer. • Al{sub 2}O{sub 3} reflective layer was deposited under the phosphor layer. • Al{sub 2}O{sub 3} reflective layer with flaky shape is very effective in enhancing luminance.
4. Luminal nucleotides are tonic inhibitors of renal tubular transport
DEFF Research Database (Denmark)
Leipziger, Jens Georg
2011-01-01
PURPOSE OF REVIEW: Extracellular ATP is an essential local signaling molecule in all organ systems. In the kidney, purinergic signaling is involved in an array of functions and this review highlights those of relevance for renal tubular transport. RECENT FINDINGS: Purinergic receptors are express...... discovered as an important signaling compartment in which local purinergic signaling determines an inhibitory tone for renal tubular transport. Blocking components of this system leads to tubular hyper-absorption, volume retention and elevated blood pressure.......PURPOSE OF REVIEW: Extracellular ATP is an essential local signaling molecule in all organ systems. In the kidney, purinergic signaling is involved in an array of functions and this review highlights those of relevance for renal tubular transport. RECENT FINDINGS: Purinergic receptors are expressed...... in all renal tubular segments and their stimulation generally leads to transport inhibition. Recent evidence has identified the tubular lumen as a restricted space for purinergic signaling. The concentrations of ATP in the luminal fluids are sufficiently high to inflict a tonic inhibition of renal...
5. Green Fluorescent Organic Light Emitting Device with High Luminance
Directory of Open Access Journals (Sweden)
Ning YANG
2014-06-01
Full Text Available In this work, we fabricated the small molecule green fluorescent bottom-emission organic light emitting device (OLED with the configuration of glass substrate/indium tin oxide (ITO/Copper Phthalocyanine (CuPc 25 nm/ N,N’-di(naphthalen-1-yl-N,N’-diphenyl-benzidine (NPB 45 nm/ tris(8-hydroxyquinoline aluminium (Alq3 60 nm/ Lithium fluoride (LiF 1 nm/Aluminum (Al 100 nm where CuPc and NPB are the hole injection layer and the hole transport layer, respectively. CuPc is introduced in this device to improve carrier injection and efficiency. The experimental results indicated that the turn-on voltage is 2.8 V with a maximum luminance of 23510 cd/m2 at 12 V. The maximum current efficiency and power efficiency are 4.8 cd/A at 100 cd/m2 and 4.2 lm/W at 3 V, respectively. The peak of electroluminance (EL spectrum locates at 530 nm which is typical emission peak of green light. In contrast, the maximum current efficiency and power efficiency of the device without CuPc are only 4.0 cd/A at 100 mA/cm2 and 4.2 lm/W at 3.6 V, respectively.
6. Enhanced luminance for inorganic electroluminescent devices with a charged electret
Energy Technology Data Exchange (ETDEWEB)
Wang, Fang-Hsing, E-mail: fansen@dragon.nchu.edu.tw [Department of Electrical Engineering and Graduate Institute of Optoelectronic Engineering, National Chung Hsing University, Taichung 402, Taiwan, ROC (China); Chen, Kuo-Feng [Department of Electrical Engineering and Graduate Institute of Optoelectronic Engineering, National Chung Hsing University, Taichung 402, Taiwan, ROC (China); Display Technology Center/Industrial Technology Research Institute, Hsinchu 310, Taiwan, ROC (China); Chien, Yu-Han; Chang, Chin-Chia; Chuang, Meng-Ying [Display Technology Center/Industrial Technology Research Institute, Hsinchu 310, Taiwan, ROC (China)
2013-09-15
This work proposes a novel inorganic electroluminescent (IEL) device with an electric field built-in (EFBI) technique to reduce its driving voltage and enhance its luminance. The EFBI technique was performed by charging an electret comprising a silicon dioxide film at different temperatures (25–150 °C) in powder electroluminescent (PDEL) devices. The driving voltage of the EFBI-PDEL device decreased by 61.4 V (or 20.5%) under the brightness of 269 cd/m{sup 2}, and its brightness increased by 128 cd/m{sup 2} (or 47%) at ac 300 V. The efficiency of the EFBI-PDEL device significantly increased by 0.827 lm/W (or 45.5%) at ac 300 V. The proposed EFBI-PDEL device has advantages of a low-temperature process and low cost, and potential for large-area display applications. -- Highlights: • An electric-field built-in powder electroluminescent (EFBI-PDEL) device is proposed. • The EFBI technique is performed by charging an electrets. • The driving voltage of the EFBI-PDEL device decreased by 20.5%. • The brightness of the EFBI-PDEL device increased by 47%. • The efficiency of the EFBI-PDEL device increased by 45.5%.
7. Cosmological information in the intrinsic alignments of luminous red galaxies
Energy Technology Data Exchange (ETDEWEB)
Chisari, Nora Elisa [Department of Astrophysical Sciences, Princeton University, 4 Ivy Lane, Princeton, NJ 08544 (United States); Dvorkin, Cora, E-mail: nchisari@astro.princeton.edu, E-mail: cdvorkin@ias.edu [Institute for Advanced Study, School of Natural Sciences, Einstein Drive, Princeton, NJ 08540 (United States)
2013-12-01
The intrinsic alignments of galaxies are usually regarded as a contaminant to weak gravitational lensing observables. The alignment of Luminous Red Galaxies, detected unambiguously in observations from the Sloan Digital Sky Survey, can be reproduced by the linear tidal alignment model of Catelan, Kamionkowski and Blandford (2001) on large scales. In this work, we explore the cosmological information encoded in the intrinsic alignments of red galaxies. We make forecasts for the ability of current and future spectroscopic surveys to constrain local primordial non-Gaussianity and Baryon Acoustic Oscillations (BAO) in the cross-correlation function of intrinsic alignments and the galaxy density field. For the Baryon Oscillation Spectroscopic Survey, we find that the BAO signal in the intrinsic alignments is marginally significant with a signal-to-noise ratio of 1.8 and 2.2 with the current LOWZ and CMASS samples of galaxies, respectively, and increasing to 2.3 and 2.7 once the survey is completed. For the Dark Energy Spectroscopic Instrument and for a spectroscopic survey following the EUCLID redshift selection function, we find signal-to-noise ratios of 12 and 15, respectively. Local type primordial non-Gaussianity, parametrized by f{sub NL} = 10, is only marginally significant in the intrinsic alignments signal with signal-to-noise ratios < 2 for the three surveys considered.
8. The Weak Lensing Masses of Filaments between Luminous Red Galaxies
Science.gov (United States)
Epps, Seth D.; Hudson, Michael J.
2017-07-01
In the standard model of non-linear structure formation, a cosmic web of dark-matter-dominated filaments connects dark matter haloes. In this paper, we stack the weak lensing signal of an ensemble of filaments between groups and clusters of galaxies. Specifically, we detect the weak lensing signal, using CFHTLenS galaxy ellipticities, from stacked filaments between Sloan Digital Sky Survey (SDSS)-III/Baryon Oscillation Spectroscopic Survey luminous red galaxies (LRGs). As a control, we compare the physical LRG pairs with projected LRG pairs that are more widely separated in redshift space. We detect the excess filament mass density in the projected pairs at the 5σ level, finding a mass of (1.6 ± 0.3) × 1013 M⊙ for a stacked filament region 7.1 h-1 Mpc long and 2.5 h-1 Mpc wide. This filament signal is compared with a model based on the three-point galaxy-galaxy-convergence correlation function, as developed in Clampitt et al., yielding reasonable agreement.
9. Gemini Near-infrared Spectroscopy of Luminous z~6 Quasars
DEFF Research Database (Denmark)
Jiang, Linhua; Fan, Xiaohui; Vestergaard, Marianne
2007-01-01
We present Gemini near-infrared spectroscopic observations of six luminous quasars at z=5.8$\\sim$6.3. Five of them were observed using Gemini-South/GNIRS, which provides a simultaneous wavelength coverage of 0.9--2.5 $\\mu$m in cross dispersion mode. The other source was observed in K band...... with Gemini-North/NIRI. We calculate line strengths for all detected emission lines and use their ratios to estimate gas metallicity in the broad-line regions of the quasars. The metallicity is found to be supersolar with a typical value of $\\sim$4 Z_{\\sun}, and a comparison with low-redshift observations...... shows no strong evolution in metallicity up to z$\\sim$6. The FeII/MgII ratio of the quasars is 4.9+/-1.4, consistent with low-redshift measurements. We estimate central BH masses of 10^9 to 10^{10} M_{\\sun} and Eddington luminosity ratios of order unity. We identify two MgII $\\lambda\\lambda$2796...
10. Notch3 marks clonogenic mammary luminal progenitor cells in vivo.
Science.gov (United States)
Lafkas, Daniel; Rodilla, Veronica; Huyghe, Mathilde; Mourao, Larissa; Kiaris, Hippokratis; Fre, Silvia
2013-10-14
The identity of mammary stem and progenitor cells remains poorly understood, mainly as a result of the lack of robust markers. The Notch signaling pathway has been implicated in mammary gland development as well as in tumorigenesis in this tissue. Elevated expression of the Notch3 receptor has been correlated to the highly aggressive "triple negative" human breast cancer. However, the specific cells expressing this Notch paralogue in the mammary gland remain unknown. Using a conditionally inducible Notch3-CreERT2(SAT) transgenic mouse, we genetically marked Notch3-expressing cells throughout mammary gland development and followed their lineage in vivo. We demonstrate that Notch3 is expressed in a highly clonogenic and transiently quiescent luminal progenitor population that gives rise to a ductal lineage. These cells are capable of surviving multiple successive pregnancies, suggesting a capacity to self-renew. Our results also uncover a role for the Notch3 receptor in restricting the proliferation and consequent clonal expansion of these cells.
11. The HR diagram for luminous stars in nearby galaxies
International Nuclear Information System (INIS)
Humphreys, R.M.
1978-01-01
Due to the extreme faintness of stars in other galaxies it is only possible to sample the brightest stars in the nearest galaxies. The observations must then be compared with comparable data for the brightest stars, the supergiants and O-type stars, in the Milky Way. The data for the luminous stars are most complete for the Milky Way and the Large Magellanic Cloud. The luminosities for the stars in our Galaxy are based on their membership in associations and clusters, and consequently are representative of Population I within approximately 3kpc of the Sun. The data for the stars in the LMC with spectral types O to G8 come from published observations, and the M supergiants are from the author's recent observations of red stars in the LMC. This is the first time that the M supergiants have been included in an HR diagram of the Large Cloud. The presence of the red stars is important for any discussion of the evolution of the massive stars. (Auth.)
12. Tritium application: self-luminous glass tube(SLGT)
International Nuclear Information System (INIS)
Kim, K.; Lee, S.K.; Chung, E.S.; Kim, K.S.; Kim, W.S.; Nam, G.J.
2005-01-01
To manufacture SLGTs (self-luminous glass tubes), 4 core technologies are needed: coating technology, tritium injection technology, laser sealing/cutting technology and tritium handling technology. The inside of the glass tubes is coated with greenish ZnS phosphor particles with sizes varying from 4∝5 [μm], and Cu, and Al as an activator and a co-dopant, respectively. We also found that it would be possible to produce a phosphor coated glass tube for the SLGT using the well established cold cathode fluorescent lamp (CCFL) bulb manufacturing technology. The conceptual design of the main process loop (PL) is almost done. A delicate technique will be needed for the sealing/cutting of the glass tubes. Instead of the existing torch technology, a new technology using a pulse-type laser is under investigation. The design basis of the tritium handling facilities is to minimize the operator's exposure to tritium uptake and the emission of tritium to the environment. To fulfill the requirements, major tritium handling components are located in the secondary containment such as the glove boxes (GBs) and/or the fume hoods. The tritium recovery system (TRS) is connected to a GB and PL to minimize the release of tritium as well as to remove the moisture and oxygen in the GB. (orig.)
13. Tritium application: self-luminous glass tube(SLGT)
Energy Technology Data Exchange (ETDEWEB)
Kim, K.; Lee, S.K.; Chung, E.S.; Kim, K.S.; Kim, W.S. [Nuclear Power Lab., Korea Electric Power Research Inst. (KEPRI), Daejeon (Korea); Nam, G.J. [Engineering Information Technology Center, Inst. for Advanced Engineering (IAE), Kyonggi-do (Korea)
2005-07-01
To manufacture SLGTs (self-luminous glass tubes), 4 core technologies are needed: coating technology, tritium injection technology, laser sealing/cutting technology and tritium handling technology. The inside of the glass tubes is coated with greenish ZnS phosphor particles with sizes varying from 4{proportional_to}5 [{mu}m], and Cu, and Al as an activator and a co-dopant, respectively. We also found that it would be possible to produce a phosphor coated glass tube for the SLGT using the well established cold cathode fluorescent lamp (CCFL) bulb manufacturing technology. The conceptual design of the main process loop (PL) is almost done. A delicate technique will be needed for the sealing/cutting of the glass tubes. Instead of the existing torch technology, a new technology using a pulse-type laser is under investigation. The design basis of the tritium handling facilities is to minimize the operator's exposure to tritium uptake and the emission of tritium to the environment. To fulfill the requirements, major tritium handling components are located in the secondary containment such as the glove boxes (GBs) and/or the fume hoods. The tritium recovery system (TRS) is connected to a GB and PL to minimize the release of tritium as well as to remove the moisture and oxygen in the GB. (orig.)
14. Effects of background and contour luminance on the hue and brightness of the Watercolor effect.
Science.gov (United States)
Gerardin, Peggy; Dojat, Michel; Knoblauch, Kenneth; Devinck, Frédéric
2018-03-01
Conjoint measurement was used to investigate the joint influences of the luminance of the background and the inner contour on hue- and brightness filling-in for a stimulus configuration generating a water-color effect (WCE), i.e., a wiggly bi-chromatic contour enclosing a region with the lower luminance component on the exterior. Two stimuli with the background and inner contour luminances covarying independently were successively presented, and in separate experiments, the observer judged which member of the pair's interior regions contained a stronger hue or was brighter. Braided-contour control stimuli that generated little or no perceptual filling-in were also used to assess whether observers were judging the interior regions and not the contours themselves. Three nested models of the contributions of the background and inner contour to the judgments were fit to the data by maximum likelihood and evaluated by likelihood ratio tests. Both stimulus components contributed to both the hue and brightness of the interior region with increasing luminance of the inner contour generating an assimilative filling-in for the hue judgments but a contrast effect for the brightness judgments. Control analyses showed negligible effects for the order of the luminance of the background or inner contour on the judgments. An additive contribution of both components was rejected in favor of a saturated model in which the responses depended on the levels of both stimulus components. For the hue judgments, increased background luminance led to greater hue filling-in at higher luminances of the interior contour. For the brightness judgments, the higher background luminance generated less brightness filling-in at higher luminances of the interior contour. The results indicate different effects of the inner contour and background on the induction of the brightness and coloration percepts of the WCE, suggesting that they are mediated by different mechanisms. Copyright © 2018 Elsevier
15. A complex approach to the blue-loop problem
Science.gov (United States)
2015-08-01
The problem of the blue loops during the core helium burning, outstanding for almost fifty years, is one of the most difficult and poorly understood problems in stellar astrophysics. Most of the work focused on the blue loops done so far has been performed with old stellar evolution codes and with limited computational resources. In the end the obtained conclusions were based on a small sample of models and could not have taken into account more advanced effects and interactions between them.The emergence of the blue loops depends on many details of the evolution calculations, in particular on chemical composition, opacity, mixing processes etc. The non-linear interactions between these factors contribute to the statement that in most cases it is hard to predict without a precise stellar modeling whether a loop will emerge or not. The high sensitivity of the blue loops to even small changes of the internal structure of a star yields one more issue: a sensitivity to numerical problems, which are common in calculations of stellar models on advanced stages of the evolution.To tackle this problem we used a modern stellar evolution code MESA. We calculated a large grid of evolutionary tracks (about 8000 models) with masses in the range of 3.0 - 25.0 solar masses from the zero age main sequence to the depletion of helium in the core. In order to make a comparative analysis, we varied metallicity, helium abundance and different mixing parameters resulting from convective overshooting, rotation etc.The better understanding of the properties of the blue loops is crucial for our knowledge of the population of blue supergiants or pulsating variables such as Cepheids, α-Cygni or Slowly Pulsating B-type supergiants. In case of more massive models it is also of great importance for studies of the progenitors of supernovae.
16. The Physics of the Blues
Science.gov (United States)
Gibson, J. Murray
2009-03-01
In looking at the commonalities between music and science, one sees that the musician's palette is based on the principles of physics. The pitch of a musical note is determined by the frequency of the sound wave. The scales that musicians use to create and play music can be viewed as a set of rules. What makes music interesting is how musicians develop those rules and create ambiguity with them. I will discuss the evolution of western musical scales in this context. As a particular example, Blue'' notes are very harmonic notes that are missing from the equal temperament scale. The techniques of piano blues and jazz represent the melding of African and Western music into something totally new and exciting. Live keyboard demonstrations will be used. Beyond any redeeming entertainment value the talk will emphasize the serious connections between science and art in music. Nevertheless tips will be accepted.
17. Blue breath holding is benign.
OpenAIRE
Stephenson, J B
1991-01-01
In their recent publication in this journal, Southall et al described typical cyanotic breath holding spells, both in otherwise healthy children and in those with brainstem lesions and other malformations. Their suggestions regarding possible autonomic disturbances may require further study, but they have adduced no scientific evidence to contradict the accepted view that in the intact child blue breath holding spells are benign. Those families in which an infant suffers an 'apparently life t...
18. Metabolic profiles of triple-negative and luminal A breast cancer subtypes in African-American identify key metabolic differences.
Science.gov (United States)
Tayyari, Fariba; Gowda, G A Nagana; Olopade, Olufunmilayo F; Berg, Richard; Yang, Howard H; Lee, Maxwell P; Ngwa, Wilfred F; Mittal, Suresh K; Raftery, Daniel; Mohammed, Sulma I
2018-02-20
Breast cancer, a heterogeneous disease with variable pathophysiology and biology, is classified into four major subtypes. While hormonal- and antibody-targeted therapies are effective in the patients with luminal and HER-2 subtypes, the patients with triple-negative breast cancer (TNBC) subtype do not benefit from these therapies. The incidence rates of TNBC subtype are higher in African-American women, and the evidence indicates that these women have worse prognosis compared to women of European descent. The reasons for this disparity remain unclear but are often attributed to TNBC biology. In this study, we performed metabolic analysis of breast tissues to identify how TNBC differs from luminal A breast cancer (LABC) subtypes within the African-American and Caucasian breast cancer patients, respectively. We used High-Resolution Magic Angle Spinning (HR-MAS) 1H Nuclear magnetic resonance (NMR) to perform the metabolomic analysis of breast cancer and adjacent normal tissues (total n=82 samples). TNBC and LABC subtypes in African American women exhibited different metabolic profiles. Metabolic profiles of these subtypes were also distinct from those revealed in Caucasian women. TNBC in African-American women expressed higher levels of glutathione, choline, and glutamine as well as profound metabolic alterations characterized by decreased mitochondrial respiration and increased glycolysis concomitant with decreased levels of ATP. TNBC in Caucasian women was associated with increased pyrimidine synthesis. These metabolic alterations could potentially be exploited as novel treatment targets for TNBC.
19. Properties of hot luminous stars; Proceedings of the First Boulder-Munich Workshop, Boulder, CO, Aug. 6-11, 1988
International Nuclear Information System (INIS)
Garmany, C.D.
1990-01-01
Various papers on the properties of hot luminous stars are presented. Individual topics addressed include: problems in photometry of early-type stars; digital optical morphology of OB spectra; massive-star content of the Magellanic Clouds; observations of massive OB stars; LSS 3074, a new double-lined early O-type binary; non-LTE line blanketing with elements 1-28; non-LTE analysis of four PG1159 stars; rescaling method for model atmospheres of hot stars; stellar wind albedo effects on hot photospheres; atomic data and models for hot star abundance determinations; ring nebulae analysis as a probe for WR atmospheres; coordinated observations of P Cygni; radiation-driven winds of hot luminous stars; winds of O stars: velocities and ionization; methods of radiative transfer in expanding atmospheres; mass loss from extragalactic O stars; H-alpha observations of O- and B-type stars; applicability of steady models for hot-star winds; mass of the O6Iaf star HD 153919; stellar winds in Beta Lyrae; models of WR stars; observational abundances of WR stars, the all-variable WC7 binary HD193793
20. Stereo chromatic contrast sensitivity model to blue-yellow gratings.
Science.gov (United States)
Yang, Jiachen; Lin, Yancong; Liu, Yun
2016-03-07
As a fundamental metric of human visual system (HVS), contrast sensitivity function (CSF) is typically measured by sinusoidal gratings at the detection of thresholds for psychophysically defined cardinal channels: luminance, red-green, and blue-yellow. Chromatic CSF, which is a quick and valid index to measure human visual performance and various retinal diseases in two-dimensional (2D) space, can not be directly applied into the measurement of human stereo visual performance. And no existing perception model considers the influence of chromatic CSF of inclined planes on depth perception in three-dimensional (3D) space. The main aim of this research is to extend traditional chromatic contrast sensitivity characteristics to 3D space and build a model applicable in 3D space, for example, strengthening stereo quality of 3D images. This research also attempts to build a vision model or method to check human visual characteristics of stereo blindness. In this paper, CRT screen was clockwise and anti-clockwise rotated respectively to form the inclined planes. Four inclined planes were selected to investigate human chromatic vision in 3D space and contrast threshold of each inclined plane was measured with 18 observers. Stimuli were isoluminant blue-yellow sinusoidal gratings. Horizontal spatial frequencies ranged from 0.05 to 5 c/d. Contrast sensitivity was calculated as the inverse function of the pooled cone contrast threshold. According to the relationship between spatial frequency of inclined plane and horizontal spatial frequency, the chromatic contrast sensitivity characteristics in 3D space have been modeled based on the experimental data. The results show that the proposed model can well predicted human chromatic contrast sensitivity characteristics in 3D space.
1. LUMINOUS BURIED ACTIVE GALACTIC NUCLEI AS A FUNCTION OF GALAXY INFRARED LUMINOSITY REVEALED THROUGH SPITZER LOW-RESOLUTION INFRARED SPECTROSCOPY
International Nuclear Information System (INIS)
Imanishi, Masatoshi
2009-01-01
We present the results of Spitzer Infrared Spectrograph 5-35 μm low-resolution spectroscopic energy diagnostics of ultraluminous infrared galaxies (ULIRGs) at z> 0.15, classified optically as non-Seyferts. Based on the equivalent widths of polycyclic aromatic hydrocarbon emission and the optical depths of silicate dust absorption features, we searched for signatures of intrinsically luminous, but optically elusive, buried active galactic nuclei (AGNs) in these optically non-Seyfert ULIRGs. We then combined the results with those of non-Seyfert ULIRGs at z IR 12 L sun . We found that the energetic importance of buried AGNs clearly increases with galaxy infrared luminosity, becoming suddenly discernible in ULIRGs with L IR > 10 12 L sun . For ULIRGs with buried AGN signatures, a significant fraction of infrared luminosities can be accounted for by the detected buried AGN and modestly obscured (A V < 20 mag) starburst activity. The implied masses of spheroidal stellar components in galaxies for which buried AGNs become important roughly correspond to the value separating red massive and blue less-massive galaxies in the local universe. Our results may support the widely proposed AGN-feedback scenario as the origin of galaxy downsizing phenomena, where galaxies with currently larger stellar masses previously had higher AGN energetic contributions and star formation originating infrared luminosities, and have finished their major star formation more quickly, due to stronger AGN feedback.
2. Synthesis and electroluminescent properties of blue fluorescent materials based on 9,9-diethyl-N,N-diphenyl-9 H-fluoren-2-amine substituted anthracene derivatives for organic light-emitting diodes
Energy Technology Data Exchange (ETDEWEB)
Lee, Seul Bee; Kim, Chanwoo; Park, Soo Na; Kim, Young Seok [Department of Chemistry, Sungkyunkwan University, Suwon, 440-746 (Korea, Republic of); Lee, Ho Won [Department of Information Display, Hongik University, Seoul, 121-791 (Korea, Republic of); Kim, Young Kwan, E-mail: kimyk@hongik.ac.kr [Department of Information Display, Hongik University, Seoul, 121-791 (Korea, Republic of); Yoon, Seung Soo, E-mail: ssyoon@skku.edu [Department of Chemistry, Sungkyunkwan University, Suwon, 440-746 (Korea, Republic of)
2015-11-30
Four 9,9-diethyl-N,N-diphenyl-9 H-fluoren-2-amine substituted anthracene derivatives have been designed and synthesized by Suzuki cross coupling reactions. To explore the electroluminescent properties of these blue materials, multilayer blue organic light-emitting diodes were fabricated in the following device structure: indium tin oxide (180 nm)/N,N’-diphenyl-N,N’-(1-napthyl)-(1,1′-phenyl)-4,4′-diamine (50 nm)/blue emitting materials (1–4) (30 nm)/bathophenanthroline (30 nm)/lithium quinolate (2 nm)/Al (100 nm). All devices appeared excellent deep-blue emissions. Among them, a device exhibited a maximum luminance of 5686 cd/m{sup 2}, the luminous, power and external quantum efficiencies of 5.11 cd/A, 3.79 lm/W, and 4.06% with the Commission International de L'Eclairage coordinates of (0.15, 0.15) at 500 cd/m{sup 2}, respectively. - Highlights: • We synthesized blue fluorescent materials based on anthracene derivatives. • The EL efficiencies of these materials depend on the quantum yields in solid states. • These materials have great potential for applications as blue emitter in OLEDs.
3. The First Hyper-Luminous Infrared Galaxy Discovered by WISE
Science.gov (United States)
Eisenhardt, Peter R.; Wu, Jingwen; Tsai, Chao-Wei; Assef, Roberto; Benford, Dominic; Blain, Andrew; Bridge, Carrie; Condon, J. J.; Cushing, Michael C.; Cutri, Roc;
2012-01-01
We report the discovery by the Wide-field Infrared Survey Explorer of the z = 2.452 source WISEJ181417.29+341224.9, the first hyperluminous source found in the WISE survey. WISE 1814+3412 is also the prototype for an all-sky sample of approximately 1000 extremely luminous "W1W2-dropouts" (sources faint or undetected by WISE at 3.4 and 4.6 micrometers and well detected at 12 or 22 micrometers). The WISE data and a 350 micrometers detection give a minimum bolometric luminosity of 3.7 x 10(exp 13) solar luminosity, with approximately 10(exp 14) solar luminosity plausible. Followup images reveal four nearby sources: a QSO and two Lyman Break Galaxies (LBGs) at z = 2.45, and an M dwarf star. The brighter LBG dominates the bolometric emission. Gravitational lensing is unlikely given the source locations and their different spectra and colors. The dominant LBG spectrum indicates a star formation rate approximately 300 solar mass yr(exp -1), accounting for less than or equal to 10 percent of the bolometric luminosity. Strong 22 micrometer emission relative to 350 micrometer implies that warm dust contributes significantly to the luminosity, while cooler dust normally associated with starbursts is constrained by an upper limit at 1.1 mm. Radio emission is approximately 10? above the far-infrared/radio correlation, indicating an active galactic nucleus is present. An obscured AGN combined with starburst and evolved stellar components can account for the observations. If the black hole mass follows the local MBH-bulge mass relation, the implied Eddington ratio is approximately greater than 4. WISE 1814+3412 may be a heavily obscured object where the peak AGN activity occurred prior to the peak era of star formation.
4. International Nuclear Information System (INIS)
Kovacs, A.; Omont, A.; Fiolet, N.; Beelen, A.; Dole, H.; Lagache, G.; Lonsdale, C.; Polletta, M.; Greve, T. R.; Borys, C.; Dowell, C. D.; Bell, T. A.; Cox, P.; De Breuck, C.; Farrah, D.; Menten, K. M.; Owen, F.
2010-01-01
We present SHARC-2 350 μm data on 20 luminous z ∼ 2 starbursts with S 1.2 m m > 2 mJy from the Spitzer-selected samples of Lonsdale et al. and Fiolet et al. All the sources were detected, with S 350 μ m > 25 mJy for 18 of them. With the data, we determine precise dust temperatures and luminosities for these galaxies using both single-temperature fits and models with power-law mass-temperature distributions. We derive appropriate formulae to use when optical depths are non-negligible. Our models provide an excellent fit to the 6 μm-2 mm measurements of local starbursts. We find characteristic single-component temperatures T 1 ≅ 35.5 ± 2.2 K and integrated infrared (IR) luminosities around 10 12.9±0.1 L sun for the SWIRE-selected sources. Molecular gas masses are estimated at ≅4 x 10 10 M sun , assuming κ 850 μ m = 0.15 m 2 kg -1 and a submillimeter-selected galaxy (SMG)-like gas-to-dust mass ratio. The best-fit models imply ∼>2 kpc emission scales. We also note a tight correlation between rest-frame 1.4 GHz radio and IR luminosities confirming star formation as the predominant power source. The far-IR properties of our sample are indistinguishable from the purely submillimeter-selected populations from current surveys. We therefore conclude that our original selection criteria, based on mid-IR colors and 24 μm flux densities, provides an effective means for the study of SMGs at z ∼ 1.5-2.5.
5. Endo-luminal grafting for treatment of abdominal aortic aneurysms
International Nuclear Information System (INIS)
Fu Weiguo; Wang Yuqi; Chen Fuzhen; Ye Jianrong; Wang Jianhua; Yan Zhiping; Cheng Jiemin
2000-01-01
Objective: To evaluate the preliminary clinical results of endovascular procedures for abdominal aortic aneurysms (AAA) in a prospective study. Methods: Six patients (average age 70 years, range 56 to 78) with infrarenal AAA were enrolled in Shanghai Zhongshan hospital from February 1998 to February 1999. Computed tomography and angiography were done in every patient for measurement of the length, diameter, and angulation of the proximal and distal AAA necks, aneurysm sac, and common and external iliac arteries. The average diameter of the aneurysm was 6.3 cm (range 4.6 cm to 8.0 cm). The mean proximal neck diameter was 2.0 cm (range 1.8 cm to 2.2 cm) and proximal neck length was 3.0 cm (range 2.5 cm to 3.5 cm). All patients were treated with the endo-luminal grafting for exclusion of AAA. Results: Two tubular and 4 bifurcated endo-grafts were used. All endo-graft procedures were completed successfully. One patient died of renal failure 72 hours after the procedure because of the prolonged operative time and excessive contrast medium. Aortography after the procedure showed the AAA were excluded by endo-graft and no endo-leak in the proximal or distal connections was detected. The patients could take meal and were ambulatory on the first and second postoperative day, respectively. Clinical success (aneurysm exclusion with no death or endo-leak) at 30 days was 83.3%. In the 24 months follow-up in 5 cases, no migration, endo-leak, and increasing aneurysm size were detected with spiral CT or color Duplex ultrasound. Conclusion: Based on initial results and a short term mean follow-up period of 24 months, the endovascular treatment of AAA with stent-graft system is feasible and safe. Further study will be required to observe the long term result in the exclusion of AAA
6. Luciferase inactivation in the luminous marine bacterium Vibrio harveyi.
Science.gov (United States)
Reeve, C A; Baldwin, T O
1981-06-01
Luciferase was rapidly inactivated in stationary-phase cultures of the wild type of the luminous marine bacterium Vibrio harveyi, but was stable in stationary-phase cultures of mutants of V. harveyi that are nonluminous without exogenous aldehyde, termed the aldehyde-deficient mutants. The inactivation in the wild type was halted by cell lysis and was slowed or stopped by O2 deprivation or by addition of KCN and NaF or of chloramphenicol. If KCN and NaF or chloramphenicol were added to a culture before the onset of luciferase inactivation, then luciferase inactivation did not occur. However, if these inhibitors were added after the onset of luciferase inactivation, then luciferase inactivation continued for about 2 to 3 h before the inactivation process stopped. The onset of luciferase inactivation in early stationary-phase cultures of wild-type cell coincided with a slight drop in the intracellular adenosine 5'-triphosphate (ATP) level from a relatively constant log-phase value of 20 pmol of ATP per microgram of soluble cell protein. Addition of KCN and NaF to a culture shortly after this drop in ATP caused a rapid decrease in the ATP level to about 4 pmol of ATP per microgram whereas chloramphenicol added at this same time caused a transient increase in ATP level to about 25 pmol/microgram. The aldehyde-deficient mutant (M17) showed a relatively constant log-phase ATP level identical with that of the wild-type cells, but rather than decreasing in early stationary phase, the ATP level increased to a value twice that in log-phase cells. We suggest that the inactivation of luciferase is dependent on the synthesis of some factor which is produced during stationary phase and is itself unstable, and whose synthesis is blocked by chloramphenicol or cyanide plus fluoride.
7. The watercolor effect: quantitative evidence for luminance-dependent mechanisms of long-range color assimilation.
Science.gov (United States)
Devinck, Frédéric; Delahunt, Peter B; Hardy, Joseph L; Spillmann, Lothar; Werner, John S
2005-05-01
When a dark chromatic contour delineating a figure is flanked on the inside by a brighter chromatic contour, the brighter color will spread into the entire enclosed area. This is known as the watercolor effect (WCE). Here we quantified the effect of color spreading using both color-matching and hue-cancellation tasks. Over a wide range of stimulus chromaticities, there was a reliable shift in color appearance that closely followed the direction of the inducing contour. When the contours were equated in luminance, the WCE was still present, but weak. The magnitude of the color spreading increased with increases in luminance contrast between the two contours. Additionally, as the luminance contrast between the contours increased, the chromaticity of the induced color more closely resembled that of the inside contour. The results support the hypothesis that the WCE is mediated by luminance-dependent mechanisms of long-range color assimilation.
8. Measuring high-resolution sky luminance distributions with a CCD camera.
Science.gov (United States)
Tohsing, Korntip; Schrempf, Michael; Riechelmann, Stefan; Schilke, Holger; Seckmeyer, Gunther
2013-03-10
We describe how sky luminance can be derived from a newly developed hemispherical sky imager (HSI) system. The system contains a commercial compact charge coupled device (CCD) camera equipped with a fish-eye lens. The projection of the camera system has been found to be nearly equidistant. The luminance from the high dynamic range images has been calculated and then validated with luminance data measured by a CCD array spectroradiometer. The deviation between both datasets is less than 10% for cloudless and completely overcast skies, and differs by no more than 20% for all sky conditions. The global illuminance derived from the HSI pictures deviates by less than 5% and 20% under cloudless and cloudy skies for solar zenith angles less than 80°, respectively. This system is therefore capable of measuring sky luminance with the high spatial and temporal resolution of more than a million pixels and every 20 s respectively.
9. SI 1985 No. 1048 - The Radioactive Substances (Luminous Articles) Exemption Order 1985
International Nuclear Information System (INIS)
1985-01-01
This Order, which came into force on 17 September 1985, is concerned with exemptions and exclusions under the Radioactive Substances Act 1960 in respect of radioactive luminous instruments and indicators. (NEA) [fr
10. Grain formation in the expanding gas flow around cool luminous stars
International Nuclear Information System (INIS)
Hasegawa, H.
1984-01-01
The existence of solid particles in interstellar space has been revealed by the extinction of starlight in UV, visible and IR. The important sources of interstellar grains are considered to be cool luminous mass loss stars. (author)
11. Distribution and species composition of planktonic luminous bacteria in the Arabian Sea
Digital Repository Service at National Institute of Oceanography (India)
Ramaiah, N.; Chandramohan, D.
Distribution of the total viable heterotrophic bacteria and the luminous bacteria in the neretic and oceanic waters of the west coast of India was studied. Counts of viable heterotrophs fluctuated widely, generally with a decrease in their number...
12. An Assessment of Luminance Imbalance with ANVIS at an Army Helicopter Training Airfield
National Research Council Canada - National Science Library
McLean, William
1997-01-01
One of the casual factors listed in a 1996 mid-air collision between two Australian Army helicopters in formation was a speculation of possible luminance imbalance between the right and left channels...
13. Distribution of luminous bacteria and bacterial luminescence in the equatorial region of the Indian Ocean
Digital Repository Service at National Institute of Oceanography (India)
Ramaiah, N.; Chandramohan, D.
to that of seawater, was noticed from the zooplankton samples. This may be due to the autoinduction of luciferase synthesis or the accumulation of autoinducer in the luminous microflora living in close association with zooplankton...
14. A resolution to the blue whiting (Micromesistius poutassou population paradox?
Directory of Open Access Journals (Sweden)
Fabien Pointin
Full Text Available We provide the strongest evidence to date supporting the existence of two independent blue whiting (Micromesistius poutassou (Risso, 1827 populations in the North Atlantic. In spite of extensive data collected in conjunction with the fishery, the population structure of blue whiting is poorly understood. On one hand, genetic, morphometric, otolith and drift modelling studies point towards the existence of two populations, but, on the other hand, observations of adult distributions point towards a single population. A paradox therefore arises in attempting to reconcile these two sets of information. Here we analyse 1100 observations of blue whiting larvae from the Continuous Plankton Recorder (CPR from 1948-2005 using modern statistical techniques. We show a clear spatial separation between a northern spawning area, in the Rockall Trough, and a southern one, off the Porcupine Seabight. We further show a difference in the timing of spawning between these sites of at least a month, and meaningful differences in interannual variability. The results therefore support the two-population hypothesis. Furthermore, we resolve the paradox by showing that the acoustic observations cited in support of the single-population model are not capable of resolving both populations, as they occur too late in the year and do not extend sufficiently far south to cover the southern population: the confusion is the result of a simple observational artefact. We conclude that blue whiting in the North Atlantic comprises two populations.
15. Comparison of light out-coupling enhancements in single-layer blue-phosphorescent organic light emitting diodes using small-molecule or polymer hosts
Energy Technology Data Exchange (ETDEWEB)
Chang, Yung-Ting [Institute of Chemistry, Academia Sinica, Taipei, Taiwan 11529, Taiwan (China); Department of Electrical Engineering, Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei, Taiwan 10617, Taiwan (China); Liu, Shun-Wei [Department of Electronic Engineering, Mingchi University of Technology, New Taipei, Taiwan 24301, Taiwan (China); Yuan, Chih-Hsien; Lee, Chih-Chien [Department of Electronic Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan 10607, Taiwan (China); Ho, Yu-Hsuan; Wei, Pei-Kuen [Research Center for Applied Science Academia Sinica, Taipei, Taiwan 11527, Taiwan (China); Chen, Kuan-Yu [Chilin Technology Co., LTD, Tainan City, Taiwan 71758, Taiwan (China); Lee, Yi-Ting; Wu, Min-Fei; Chen, Chin-Ti, E-mail: cchen@chem.sinica.edu.tw, E-mail: chihiwu@cc.ee.ntu.edu.tw [Institute of Chemistry, Academia Sinica, Taipei, Taiwan 11529, Taiwan (China); Wu, Chih-I, E-mail: cchen@chem.sinica.edu.tw, E-mail: chihiwu@cc.ee.ntu.edu.tw [Department of Electrical Engineering, Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei, Taiwan 10617, Taiwan (China)
2013-11-07
Single-layer blue phosphorescence organic light emitting diodes (OLEDs) with either small-molecule or polymer hosts are fabricated using solution process and the performances of devices with different hosts are investigated. The small-molecule device exhibits luminous efficiency of 14.7 cd/A and maximum power efficiency of 8.39 lm/W, which is the highest among blue phosphorescence OLEDs with single-layer solution process and small molecular hosts. Using the same solution process for all devices, comparison of light out-coupling enhancement, with brightness enhancement film (BEF), between small-molecule and polymer based OLEDs is realized. Due to different dipole orientation and anisotropic refractive index, polymer-based OLEDs would trap less light than small molecule-based OLEDs internally, about 37% better based simulation results. In spite of better electrical and spectroscopic characteristics, including ambipolar characteristics, higher carrier mobility, higher photoluminescence quantum yield, and larger triplet state energy, the overall light out-coupling efficiency of small molecule-based devices is worse than that of polymer-based devices without BEF. However, with BEF for light out-coupling enhancement, the improved ratio in luminous flux and luminous efficiency for small molecule based device is 1.64 and 1.57, respectively, which are significantly better than those of PVK (poly-9-vinylcarbazole) devices. In addition to the theoretical optical simulation, the experimental data also confirm the origins of differential light-outcoupling enhancement. The maximum luminous efficiency and power efficiency are enhanced from 14.7 cd/A and 8.39 lm/W to 23 cd/A and 13.2 lm/W, respectively, with laminated BEF, which are both the highest so far for single-layer solution-process blue phosphorescence OLEDs with small molecule hosts.
16. Comparison of light out-coupling enhancements in single-layer blue-phosphorescent organic light emitting diodes using small-molecule or polymer hosts
International Nuclear Information System (INIS)
Chang, Yung-Ting; Liu, Shun-Wei; Yuan, Chih-Hsien; Lee, Chih-Chien; Ho, Yu-Hsuan; Wei, Pei-Kuen; Chen, Kuan-Yu; Lee, Yi-Ting; Wu, Min-Fei; Chen, Chin-Ti; Wu, Chih-I
2013-01-01
Single-layer blue phosphorescence organic light emitting diodes (OLEDs) with either small-molecule or polymer hosts are fabricated using solution process and the performances of devices with different hosts are investigated. The small-molecule device exhibits luminous efficiency of 14.7 cd/A and maximum power efficiency of 8.39 lm/W, which is the highest among blue phosphorescence OLEDs with single-layer solution process and small molecular hosts. Using the same solution process for all devices, comparison of light out-coupling enhancement, with brightness enhancement film (BEF), between small-molecule and polymer based OLEDs is realized. Due to different dipole orientation and anisotropic refractive index, polymer-based OLEDs would trap less light than small molecule-based OLEDs internally, about 37% better based simulation results. In spite of better electrical and spectroscopic characteristics, including ambipolar characteristics, higher carrier mobility, higher photoluminescence quantum yield, and larger triplet state energy, the overall light out-coupling efficiency of small molecule-based devices is worse than that of polymer-based devices without BEF. However, with BEF for light out-coupling enhancement, the improved ratio in luminous flux and luminous efficiency for small molecule based device is 1.64 and 1.57, respectively, which are significantly better than those of PVK (poly-9-vinylcarbazole) devices. In addition to the theoretical optical simulation, the experimental data also confirm the origins of differential light-outcoupling enhancement. The maximum luminous efficiency and power efficiency are enhanced from 14.7 cd/A and 8.39 lm/W to 23 cd/A and 13.2 lm/W, respectively, with laminated BEF, which are both the highest so far for single-layer solution-process blue phosphorescence OLEDs with small molecule hosts
17. High luminous flux from single crystal phosphor-converted laser-based white lighting system
KAUST Repository
Cantore, Michael; Pfaff, Nathan; Farrell, Robert M.; Speck, James S.; Nakamura, Shuji; DenBaars, Steven P.
2015-01-01
efficacy of 86.7 lm/W at 1.4 A and 4.24 V and a peak luminous flux of 1100 lm at 3.0 A and 4.85 V with a luminous efficacy of 75.6 lm/W. Simulations of a pc-LD confirm that the single crystal YAG:Ce sample did not experience thermal quenching at peak LD
18. Transferable chloramphenicol resistance determinant in luminous Vibrio harveyi from penaeid shrimp Penaeus monodon larvae
Directory of Open Access Journals (Sweden)
Thangapalam Jawahar Abraham
2016-12-01
Full Text Available Antibiotic-resistant luminous Vibrio harveyi strains isolated from Penaeus monodon larvae were screened for the possession of transferable resistance determinants. All the strains were resistant to chloramphenicol and the determinant coding for chloramphenicol resistance was transferred to Escherichia coli at frequencies of 9.50x10-4 to 4.20x10-4. The results probably suggest the excessive use of chloramphenicol in shrimp hatcheries to combat luminous vibriosis.
19. The impact of luminance on tonic and phasic pupillary responses to sustained cognitive load.
Science.gov (United States)
Peysakhovich, Vsevolod; Vachon, François; Dehais, Frédéric
2017-02-01
20. Blue mussel shell shape plasticity and natural environments: a quantitative approach
DEFF Research Database (Denmark)
Telesca, Luca; Michalek, Kati; Sanders, Trystan
2018-01-01
Shape variability represents an important direct response of organisms to selective environments. Here, we use a combination of geometric morphometrics and generalised additive mixed models (GAMMs) to identify spatial patterns of natural shell shape variation in the North Atlantic and Arctic blue...... scales analysed. Our results show how shell shape plasticity represents a powerful indicator to understand the alterations of blue mussel communities in rapidly changing environments....
1. Evaluation of Code Blue Implementation Outcomes
Directory of Open Access Journals (Sweden)
Bengü Özütürk
2015-09-01
Full Text Available Aim: In this study, we aimed to emphasize the importance of Code Blue implementation and to determine deficiencies in this regard. Methods: After obtaining the ethics committee approval, 225 patient’s code blue call data between 2012 and 2014 January were retrospectively analyzed. Age and gender of the patients, date and time of the call and the clinics giving Code Blue, the time needed for the Code Blue team to arrive, the rates of false Code Blue calls, reasons for Code Blue calls and patient outcomes were investigated. Results: A total of 225 patients (149 male, 76 female were evaluated in the study. The mean age of the patients was 54.1 years. 142 (67.2% Code Blue calls occurred after hours and by emergency unit. The mean time for the Code Blue team to arrive was 1.10 minutes. Spontaneous circulation was provided in 137 patients (60.8%; 88 (39.1% died. The most commonly identified possible causes were of cardiac origin. Conclusion: This study showed that Code Blue implementation with a professional team within an efficient and targeted time increase the survival rate. Therefore, we conclude that the application of Code Blue carried out by a trained team is an essential standard in hospitals. (The Medical Bulletin of Haseki 2015; 53:204-8
2. Mercury-free electrodeless discharge lamp: effect of xenon pressure and plasma parameters on luminance
International Nuclear Information System (INIS)
Nazri Dagang Ahmad; Kondo, Akira; Motomura, Hideki; Jinno, Masafumi
2009-01-01
Since there is much concern about environmental preservation, the authors have paid attention to the uses of mercury in lighting application. They have focused on the application of the xenon low-pressure inductively coupled plasma (ICP) discharge in developing cylindrical type mercury-free light sources. ICP can be operated at low filling gas pressures and demonstrates significant potential in producing high density plasma. Xenon pressure was varied from 0.1 to 100 Torr and the lamp luminance was measured. The gas pressure dependence shows an increase in luminance at pressures below 1 Torr. In order to clarify this behaviour, measurement of plasma parameters was carried out using the double probe method and its relation to lamp luminance is discussed. As the gas pressure is decreased (from 1 to 0.01 Torr), the electron temperature increases while the electron density decreases while at the same time the lamp luminance increases. There are several factors that are believed to contribute to the increase in luminance in the very low pressure region. Increases in luminance are considered to be due to the electron-ion recombination process which brings a strong recombination radiation in continuum in the visible region and also due to the effect of stochastic heating.
3. Nonlinear mapping of the luminance in dual-layer high dynamic range displays
Science.gov (United States)
Guarnieri, Gabriele; Ramponi, Giovanni; Bonfiglio, Silvio; Albani, Luigi
2009-02-01
It has long been known that the human visual system (HVS) has a nonlinear response to luminance. This nonlinearity can be quantified using the concept of just noticeable difference (JND), which represents the minimum amplitude of a specified test pattern an average observer can discern from a uniform background. The JND depends on the background luminance following a threshold versus intensity (TVI) function. It is possible to define a curve which maps physical luminances into a perceptually linearized domain. This mapping can be used to optimize a digital encoding, by minimizing the visibility of quantization noise. It is also commonly used in medical applications to display images adapting to the characteristics of the display device. High dynamic range (HDR) displays, which are beginning to appear on the market, can display luminance levels outside the range in which most standard mapping curves are defined. In particular, dual-layer LCD displays are able to extend the gamut of luminance offered by conventional liquid crystals towards the black region; in such areas suitable and HVS-compliant luminance transformations need to be determined. In this paper we propose a method, which is primarily targeted to the extension of the DICOM curve used in medical imaging, but also has a more general application. The method can be modified in order to compensate for the ambient light, which can be significantly greater than the black level of an HDR display and consequently reduce the visibility of the details in dark areas.
4. Near-field visual acuity of pigeons: effects of head location and stimulus luminance.
Science.gov (United States)
Hodos, W; Leibowitz, R W; Bonbright, J C
1976-03-01
Two pigeons were trained to discriminate a grating stimulus from a blank stimulus of equivalent luminance in a three-key chamber. The stimuli and blanks were presented behind a transparent center key. The procedure was a conditional discrimination in which pecks on the left key were reinforced if the blank had been present behind the center key and pecks on the right key were reinforced if the grating had been present behind the center key. The spatial frequency of the stimuli was varied in each session from four to 29.5 lines per millimeter in accordance with a variation of the method of constant stimuli. The number of lines per millimeter that the subjects could discriminate at threshold was determined from psychometric functions. Data were collected at five values of stimulus luminance ranging from--0.07 to 3.29 log cd/m2. The distance from the stimulus to the anterior nodal point of the eye, which was determined from measurements taken from high-speed motion-picture photographs of three additional pigeons and published intraocular measurements, was 62.0 mm. This distance and the grating detection thresholds were used to calculate the visual acuity of the birds at each level of luminance. Acuity improved with increasing luminance to a peak value of 0.52, which corresponds to a visual angle of 1.92 min, at a luminance of 2.33 log cd/m2. Further increase in luminance produced a small decline in acuity.
5. Study of luminous emissions associated to electron emissions in radiofrequency cavities
International Nuclear Information System (INIS)
Maissa, S.
1996-01-01
This study investigates luminous emissions simultaneously to electron emissions and examines their features in order to better understand the field electron emission phenomenon. A RF cavity, operating at room temperature and in pulsed mode, joined to a sophisticated experimental apparatus has been especially developed. The electron and luminous emissions are investigated on cleaned or with metallic, graphitic and dielectric particles contaminated RF surfaces in order to study their influence on these phenomena. During the surface processing, unstable luminous spots glowing during one RF pulse are detected. Their apparition is promoted in the vicinity of the metallic particles or scratches. Two hypotheses could explain their origin: the presence of micro-plasmas associated to electronic explosive emission during processing or the thermal radiation of the melted metal during this emission. Stable luminous spots glowing during several RF pulses are also detected and appear to increase on RF surfaces contaminated with dielectric particles, leading to strong and explosive luminous emissions. Two interpretations are considered: the initiation of surface breakdowns on the dielectric particles or the heating by the RF field at temperatures sufficiently intense to provoke their thermal radiation then their explosion. Finally a superconducting cavity has been adapted to observe luminous spots, which differ from the former ones bu their star shape and could be associated to micro-plasmas, revealed by the starbursts observed on superconducting cavity walls. (author)
6. Competition between color and luminance for target selection in smooth pursuit and saccadic eye movements.
Science.gov (United States)
Spering, Miriam; Montagnini, Anna; Gegenfurtner, Karl R
2008-11-24
Visual processing of color and luminance for smooth pursuit and saccadic eye movements was investigated using a target selection paradigm. In two experiments, stimuli were varied along the dimensions color and luminance, and selection of the more salient target was compared in pursuit and saccades. Initial pursuit was biased in the direction of the luminance component whereas saccades showed a relative preference for color. An early pursuit response toward luminance was often reversed to color by a later saccade. Observers' perceptual judgments of stimulus salience, obtained in two control experiments, were clearly biased toward luminance. This choice bias in perceptual data implies that the initial short-latency pursuit response agrees with perceptual judgments. In contrast, saccades, which have a longer latency than pursuit, do not seem to follow the perceptual judgment of salience but instead show a stronger relative preference for color. These substantial differences in target selection imply that target selection processes for pursuit and saccadic eye movements use distinctly different weights for color and luminance stimuli.
7. Photographic and LMA observations of a blue starter over a New Mexico thunderstorm
Science.gov (United States)
Edens, H. E.; Krehbiel, P. R.; Rison, W.; Hunyady, S. J.
2010-12-01
8. Liquid biofuels from blue biomass
DEFF Research Database (Denmark)
Kádár, Zsófia; Jensen, Annette Eva; Bangsø Nielsen, Henrik
2011-01-01
Marine (blue) biomasses, such as macroalgaes, represent a huge unexploited amount of biomass. With their various chemical compositions, macroalgaes can be a potential substrate for food, feed, biomaterials, pharmaceuticals, health care products and also for bioenergy. Algae use seawater as a growth...... medium, light as energy source and they capture CO2 for the synthesis of new organic material, thus can grow on non-agricultural land, without increasing food prices, or using fresh water. Due to all these advantages in addition to very high biomass yield with high carbohydrate content, macroalgaes can...
9. Markkinointisuunnitelma Case: Ringetteseura Blue Rings
OpenAIRE
Seppälä, Minna
2012-01-01
Tämän opinnäytetyön tarkoituksena on markkinointisuunnitelman laatiminen ringetteseura Blue Ringsin edustusjoukkueelle. Lähtökohtana on pidetty suunnitelman toteutuskelpoisuutta käytännössä sekä suunnitelman reaalisuutta. Opinnäytetyö on toteutettu projektityönä, jossa on käytetty benchmarkkauksen lisäksi sekä kvalitatiivisia että empiirisiä tutkimusmenetelmiä. Opinnäytetyö koostuu kahdesta osiosta; teoreettinen viitekehys sekä empiirinen osio. Teoriana opinnäytetyössä on käytetty markkinoinn...
10. Improvement of efficiency roll-off in blue phosphorescence OLED using double dopants emissive layer
Energy Technology Data Exchange (ETDEWEB)
Yoo, Seung Il; Yoon, Ju An; Kim, Nam Ho; Kim, Jin Wook; Kang, Jin Sung; Moon, Chang-Bum [Department of Green Energy & Semiconductor Engineering, Hoseo University, Asan (Korea, Republic of); Kim, Woo Young, E-mail: wykim@hoseo.edu [Department of Green Energy & Semiconductor Engineering, Hoseo University, Asan (Korea, Republic of); Department of Engineering Physics, McMaster University, Hamilton, Ontario L8S 4L7 (Canada)
2015-04-15
Blue phosphorescent organic light-emitting diodes (PHOLEDs) were fabricated using double dopants FIrpic and FIr6 in emissive layer (EML) with structure of ITO/NPB (700 Å)/mCP:FIrpic-8%:FIr6-x% (300 Å)/TPBi (300 Å)/Liq (20 Å)/Al (1200 Å). We optimized concentration of the second dopant FIr6 in the presence of a fixed FIrpic to observe its effect on electrical performance of PHOLED device. 24.8 cd/A of luminous efficiency was achieved by the device with dopant ratio of 8%FIrpic:4%FIr6 in EML. Efficiency roll-off was also improved 20% compared to the PHOLED device singly dopped with FIrpic or FIr6 only. Second doping proved its effect in stabilizing charge balance in EML and enhancing energy transfer of triplet excitons between two dopants. - Highlights: • We fabricated blue PHOLED with double blue phosphorescent dopants in single EML. • Efficiency roll-off was improved by using double dopant in single EML. • The host–dopant transfer is discussed by analyzing the photo-absorption and photoluminescence. • The spectroscopic analysis using multi-peak fits with a Gaussian function.
11. High color rendering index white organic light-emitting diode using levofloxacin as blue emitter
International Nuclear Information System (INIS)
Miao Yan-Qin; Zhang Ai-Qin; Li Yuan-Hao; Wang Hua; Jia Hu-Sheng; Liu Xu-Guang; Gao Zhi-Xiang; Tsuboi Taijuf
2015-01-01
Levofloxacin (LOFX), which is well-known as an antibiotic medicament, was shown to be useful as a 452-nm blue emitter for white organic light-emitting diodes (OLEDs). In this paper, the fabricated white OLED contains a 452-nm blue emitting layer (thickness of 30 nm) with 1 wt% LOFX doped in CBP (4,4’-bis(carbazol-9-yl)biphenyl) host and a 584-nm orange emitting layer (thickness of 10 nm) with 0.8 wt% DCJTB (4-(dicyanomethylene)-2-tert-butyl-6-(1,1,7, 7-tetramethyljulolidin-4-yl-vinyl)-4H-pyran) doped in CBP, which are separated by a 20-nm-thick buffer layer of TPBi (2,2’,2”-(benzene-1,3,5-triyl)-tri(1-phenyl-1H-benzimidazole). A high color rendering index (CRI) of 84.5 and CIE chromaticity coordinates of (0.33, 0.32), which is close to ideal white emission CIE (0.333, 0.333), are obtained at a bias voltage of 14 V. Taking into account that LOFX is less expensive and the synthesis and purification technologies of LOFX are mature, these results indicate that blue fluorescence emitting LOFX is useful for applications to white OLEDs although the maximum current efficiency and luminance are not high. The present paper is expected to become a milestone to using medical drug materials for OLEDs. (paper)
12. Relationship of the luminous bacterial symbiont of the Caribbean flashlight fish, Kryptophanaron alfredi (family Anomalopidae) to other luminous bacteria based on bacterial luciferase (luxA) genes.
Science.gov (United States)
Haygood, M G
1990-01-01
Flashlight fishes (family Anomalopidae) have light organs that contain luminous bacterial symbionts. Although the symbionts have not yet been successfully cultured, the luciferase genes have been cloned directly from the light organ of the Caribbean species, Kryptophanaron alfredi. The goal of this project was to evaluate the relationship of the symbiont to free-living luminous bacteria by comparison of genes coding for bacterial luciferase (lux genes). Hybridization of a lux AB probe from the Kryptophanaron alfredi symbiont to DNAs from 9 strains (8 species) of luminous bacteria showed that none of the strains tested had lux genes highly similar to the symbiont. The most similar were a group consisting of Vibrio harveyi, Vibrio splendidus and Vibrio orientalis. The nucleotide sequence of the luciferase alpha subunit gene luxA) of the Kryptophanaron alfredi symbiont was determined in order to do a more detailed comparison with published luxA sequences from Vibrio harveyi, Vibrio fischeri and Photobacterium leiognathi. The hybridization results, sequence comparisons and the mol% G + C of the Kryptophanaron alfredi symbiont luxA gene suggest that the symbiont may be considered as a new species of luminous Vibrio related to Vibrio harveyi.
13. Improving the color purity and efficiency of blue organic light-emitting diodes (BOLED) by adding hole-blocking layer
Energy Technology Data Exchange (ETDEWEB)
Huang, C.J., E-mail: chien@nuk.edu.t [Department of Applied Physics, National University of Kaohsiung, 700 Kaohsiung University Road, Nan-Tzu, Kaohsiung, Taiwan (China); Kang, C.C. [Department of Electro-Optical Engineering, Southern Taiwan University of Technology, 1 Nan-Tai St., Yung-Kang City, Tainan, Taiwan (China); Lee, T.C. [Department of Electrical Engineering, Southern Taiwan University of Technology, 1 Nan-Tai St., Yung-Kang City, Tainan, Taiwan (China); Chen, W.R.; Meen, T.H. [Department of Electronic Engineering, National Formosa University, 64 Wen-Hwa Road, Hu-Wei, Yunlin, Taiwan (China)
2009-11-15
This work demonstrates the fabrication of a bright blue organic light-emitting diode (BOLED) with good color purity using 4,4'-bis(2,2-diphenylvinyl)-1,1'-biphenyl (DPVBi) and bathocuproine (BCP) as the emitting layer (EML) and the hole-blocking layer (HBL), respectively. Devices were prepared by vacuum deposition on indium tin oxide (ITO)-glass substrates. The thickness of DPVBi used in the OLED has an important effect on color and efficiency. The blue luminescence is maximal at 7670 cd/m{sup 2} when 13 V is applied and the BCP thickness is 2 nm. The CIE coordinate at a luminance of 7670 cd/m{sup 2} is (0.165, 0.173). Furthermore, the current efficiency is maximum at 4.25 cd/A when 9 V is applied.
14. Improving the color purity and efficiency of blue organic light-emitting diodes (BOLED) by adding hole-blocking layer
International Nuclear Information System (INIS)
Huang, C.J.; Kang, C.C.; Lee, T.C.; Chen, W.R.; Meen, T.H.
2009-01-01
This work demonstrates the fabrication of a bright blue organic light-emitting diode (BOLED) with good color purity using 4,4'-bis(2,2-diphenylvinyl)-1,1'-biphenyl (DPVBi) and bathocuproine (BCP) as the emitting layer (EML) and the hole-blocking layer (HBL), respectively. Devices were prepared by vacuum deposition on indium tin oxide (ITO)-glass substrates. The thickness of DPVBi used in the OLED has an important effect on color and efficiency. The blue luminescence is maximal at 7670 cd/m 2 when 13 V is applied and the BCP thickness is 2 nm. The CIE coordinate at a luminance of 7670 cd/m 2 is (0.165, 0.173). Furthermore, the current efficiency is maximum at 4.25 cd/A when 9 V is applied.
15. Electronic properties of blue phosphorene/graphene and blue phosphorene/graphene-like gallium nitride heterostructures.
Science.gov (United States)
Sun, Minglei; Chou, Jyh-Pin; Yu, Jin; Tang, Wencheng
2017-07-05
Blue phosphorene (BlueP) is a graphene-like phosphorus nanosheet which was synthesized very recently for the first time [Nano Lett., 2016, 16, 4903-4908]. The combination of electronic properties of two different two-dimensional materials in an ultrathin van der Waals (vdW) vertical heterostructure has been proved to be an effective approach to the design of novel electronic and optoelectronic devices. Therefore, we used density functional theory to investigate the structural and electronic properties of two BlueP-based heterostructures - BlueP/graphene (BlueP/G) and BlueP/graphene-like gallium nitride (BlueP/g-GaN). Our results showed that the semiconducting nature of BlueP and the Dirac cone of G are well preserved in the BlueP/G vdW heterostructure. Moreover, by applying a perpendicular electric field, it is possible to tune the position of the Dirac cone of G with respect to the band edge of BlueP, resulting in the ability to control the Schottky barrier height. For the BlueP/g-GaN vdW heterostructure, BlueP forms an interface with g-GaN with a type-II band alignment, which is a promising feature for unipolar electronic device applications. Furthermore, we discovered that both G and g-GaN can be used as an active layer for BlueP to facilitate charge injection and enhance the device performance.
16. Starbursts in Blue compact dwarf galaxies
International Nuclear Information System (INIS)
Thuan, T.X.
1987-01-01
We summarize all the arguments for a bursting mode of star formation in blue compact dwarf galaxies. We show in particular how spectral synthesis of far ultraviolet spectra of Blue compact dwarf galaxy constitutes a powerful way for studying the star formation history in these galaxies. Blue compact dwarf galaxy luminosity functions show jumps and discontinuities. These jumps act like fossil records of the star-forming bursts, helping us to count and date the bursts
17. Geothermal Technologies Program Blue Ribbon Panel Recommendations
Energy Technology Data Exchange (ETDEWEB)
none,
2011-06-17
The Geothermal Technologies Program assembled a geothermal Blue Ribbon Panel on March 22-23, 2011 in Albuquerque, New Mexico for a guided discussion on the future of geothermal energy in the United States and the role of the DOE Program. The Geothermal Blue Ribbon Panel Report captures the discussions and recommendations of the experts. An addendum is available here: http://www.eere.energy.gov/geothermal/pdfs/gtp_blue_ribbon_panel_report_addendum10-2011.pdf
18. Why Blue-Collar Blacks Help Less
OpenAIRE
Smith, Sandra Susan; Young, Kara Alexis
2013-01-01
Why are blue-collar blacks less likely to help jobseekers than jobholders from other ethnoracial groups or even than more affluent blacks? Drawing from in-depth, semi-structured interviews with 97 black and Latino workers at one large, public sector employer, we find that blue-collar black workers both helped less proactively and rejected more requests for assistance than did blue-collar Latino and white-collar black workers. We attribute blue-collar blacks’ more passive engagement to their...
19. DACH1: its role as a classifier of long term good prognosis in luminal breast cancer.
Directory of Open Access Journals (Sweden)
Desmond G Powe
Full Text Available BACKGROUND: Oestrogen receptor (ER positive (luminal tumours account for the largest proportion of females with breast cancer. Theirs is a heterogeneous disease presenting clinical challenges in managing their treatment. Three main biological luminal groups have been identified but clinically these can be distilled into two prognostic groups in which Luminal A are accorded good prognosis and Luminal B correlate with poor prognosis. Further biomarkers are needed to attain classification consensus. Machine learning approaches like Artificial Neural Networks (ANNs have been used for classification and identification of biomarkers in breast cancer using high throughput data. In this study, we have used an artificial neural network (ANN approach to identify DACH1 as a candidate luminal marker and its role in predicting clinical outcome in breast cancer is assessed. MATERIALS AND METHODS: A reiterative ANN approach incorporating a network inferencing algorithm was used to identify ER-associated biomarkers in a publically available cDNA microarray dataset. DACH1 was identified in having a strong influence on ER associated markers and a positive association with ER. Its clinical relevance in predicting breast cancer specific survival was investigated by statistically assessing protein expression levels after immunohistochemistry in a series of unselected breast cancers, formatted as a tissue microarray. RESULTS: Strong nuclear DACH1 staining is more prevalent in tubular and lobular breast cancer. Its expression correlated with ER-alpha positive tumours expressing PgR, epithelial cytokeratins (CK18/19 and 'luminal-like' markers of good prognosis including FOXA1 and RERG (p<0.05. DACH1 is increased in patients showing longer cancer specific survival and disease free interval and reduced metastasis formation (p<0.001. Nuclear DACH1 showed a negative association with markers of aggressive growth and poor prognosis. CONCLUSION: Nuclear DACH1 expression
20. The Fictional Black Blues Figure: Blues Music and the Art of Narrative Self-Invention
OpenAIRE
Mack, Kimberly
2015-01-01
The Fictional Black Blues Figure: Blues Music and the Art of Narrative Self-Invention, Kimberly MackMy dissertation examines representations of black American blues musicians in contemporary American fiction, drama, and popular music, and it argues that blues music can be examined as a narrative art rooted in the tradition of fictionalized autobiographical self-fashioning. I contend that the contemporary, multi-racial, literary and musical characters in my project who participate in so-called...
1. Dynamic contrast-enhanced MRI in patients with luminal Crohn's disease
International Nuclear Information System (INIS)
Ziech, M.L.W.; Lavini, C.; Caan, M.W.A.; Nio, C.Y.; Stokkers, P.C.F.; Bipat, S.; Ponsioen, C.Y.; Nederveen, A.J.; Stoker, J.
2012-01-01
Objectives: To prospectively assess dynamic contrast-enhanced (DCE-)MRI as compared to conventional sequences in patients with luminal Crohn's disease. Methods: Patients with Crohn's disease undergoing MRI and ileocolonoscopy within 1 month had DCE-MRI (3T) during intravenous contrast injection of gadobutrol, single shot fast spin echo sequence and 3D T1-weighted spoiled gradient echo sequence, a dynamic coronal 3D T1-weighted fast spoiled gradient were performed before and after gadobutrol. Maximum enhancement (ME) and initial slope of increase (ISI) were calculated for four colon segments (ascending colon + coecum, transverse colon, descending colon + sigmoid, rectum) and (neo)terminal ileum. C-reactive protein (CRP), Crohn's disease activity index (CDAI), per patient and per segment Crohn's disease endoscopic index of severity (CDEIS) and disease duration were determined. Mean values of the (DCE-)MRI parameters in each segment from each patient were compared between four disease activity groups (normal mucosa, non-ulcerative lesions, mild ulcerative and severe ulcerative disease) with Mann–Whitney test with Bonferroni adjustment. Spearman correlation coefficients were calculated for continuous variables. Results: Thirty-three patients were included (mean age 37 years; 23 females, median CDEIS 4.4). ME and ISI correlated weakly with segmental CDEIS (r = 0.485 and r = 0.206) and ME per patient correlated moderately with CDEIS (r = 0.551). ME was significantly higher in segments with mild (0.378) or severe (0.388) ulcerative disease compared to normal mucosa (0.304) (p < 0.001). No ulcerations were identified at conventional sequences. ME correlated with disease duration in diseased segments (r = 0.492), not with CDAI and CRP. Conclusions: DCE-MRI can be used as a method for detecting Crohn's disease ulcerative lesions.
2. Dynamic contrast-enhanced MRI in patients with luminal Crohn's disease
Energy Technology Data Exchange (ETDEWEB)
2012-11-15
Objectives: To prospectively assess dynamic contrast-enhanced (DCE-)MRI as compared to conventional sequences in patients with luminal Crohn's disease. Methods: Patients with Crohn's disease undergoing MRI and ileocolonoscopy within 1 month had DCE-MRI (3T) during intravenous contrast injection of gadobutrol, single shot fast spin echo sequence and 3D T1-weighted spoiled gradient echo sequence, a dynamic coronal 3D T1-weighted fast spoiled gradient were performed before and after gadobutrol. Maximum enhancement (ME) and initial slope of increase (ISI) were calculated for four colon segments (ascending colon + coecum, transverse colon, descending colon + sigmoid, rectum) and (neo)terminal ileum. C-reactive protein (CRP), Crohn's disease activity index (CDAI), per patient and per segment Crohn's disease endoscopic index of severity (CDEIS) and disease duration were determined. Mean values of the (DCE-)MRI parameters in each segment from each patient were compared between four disease activity groups (normal mucosa, non-ulcerative lesions, mild ulcerative and severe ulcerative disease) with Mann-Whitney test with Bonferroni adjustment. Spearman correlation coefficients were calculated for continuous variables. Results: Thirty-three patients were included (mean age 37 years; 23 females, median CDEIS 4.4). ME and ISI correlated weakly with segmental CDEIS (r = 0.485 and r = 0.206) and ME per patient correlated moderately with CDEIS (r = 0.551). ME was significantly higher in segments with mild (0.378) or severe (0.388) ulcerative disease compared to normal mucosa (0.304) (p < 0.001). No ulcerations were identified at conventional sequences. ME correlated with disease duration in diseased segments (r = 0.492), not with CDAI and CRP. Conclusions: DCE-MRI can be used as a method for detecting Crohn's disease ulcerative lesions.
3. The analysis and comparison of blue wool fibre populations found at random on clothing.
Science.gov (United States)
Wiggins, K; Drummond, P
2005-01-01
Fifty-eight garments were taped and searched for mid to dark blue wool fibres. These were then removed from the tapings, mounted on slides and examined using a high-power microscope (400x). A total of 2,740 blue wool fibres were identified and visible range microspectrophotometry (MSP) was performed on them. Three hundred independent blue wool populations were identified on 56 of the 58 garments searched. The lack of control fibres meant the spectral range of each population was unknown. The number of populations may have been underestimated by grouping together the fibres that had broad single peaks and a lack of distinguishing features in the spectra. Although blue wool is considered to be a common fibre type, 300 unique spectral shapes were identified by the use of microspectrophotometry alone. This demonstrates that the dyes used in the dyeing of blue wool are variable. Showing that many different populations of blue wool occur on a range of garments should ensure that the forensic scientist does not underestimate or understate the strength of evidence in cases where blue wool is found. Hopefully this work will enlighten scientists and enable them to also assess the true value of their findings when other commonly occurring fibres are encountered.
4. Reduction of blue tungsten oxide
International Nuclear Information System (INIS)
Wilken, T.; Wert, C.; Woodhouse, J.; Morcom, W.
1975-01-01
A significant portion of commercial tungsten is produced by hydrogen reduction of oxides. Although several modes of reduction are possible, hydrogen reduction is used where high purity tungsten is required and where the addition of other elements or compounds is desired for modification of the metal, as is done for filaments in the lamp industry. Although several investigations of the reduction of oxides have been reported (1 to 5), few principles have been developed which can aid in assessment of current commercial practice. The reduction process was examined under conditions approximating commercial practice. The specific objectives were to determine the effects of dopants, of water vapor in the reducing atmosphere, and of reduction temperature upon: (1) the rate of the reaction by which blue tungsten oxide is reduced to tungsten metal, (2) the intermediate oxides associated with reduction, and (3) the morphology of the resulting tungsten powder
5. The University of Montana's Blue Mountain Observatory
Science.gov (United States)
Friend, D. B.
2004-12-01
The University of Montana's Department of Physics and Astronomy runs the state of Montana's only professional astronomical observatory. The Observatory, located on nearby Blue Mountain, houses a 16 inch Boller and Chivens Cassegrain reflector (purchased in 1970), in an Ash dome. The Observatory sits just below the summit ridge, at an elevation of approximately 6300 feet. Our instrumentation includes an Op-Tec SSP-5A photoelectric photometer and an SBIG ST-9E CCD camera. We have the only undergraduate astronomy major in the state (technically a physics major with an astronomy option), so our Observatory is an important component of our students' education. Students have recently carried out observing projects on the photometry of variable stars and color photometry of open clusters and OB associations. In my poster I will show some of the data collected by students in their observing projects. The Observatory is also used for public open houses during the summer months, and these have become very popular: at times we have had 300 visitors in a single night.
6. Glossiness and perishable food quality: visual freshness judgment of fish eyes based on luminance distribution.
Science.gov (United States)
Murakoshi, Takuma; Masuda, Tomohiro; Utsumi, Ken; Tsubota, Kazuo; Wada, Yuji
2013-01-01
Previous studies have reported the effects of statistics of luminance distribution on visual freshness perception using pictures which included the degradation process of food samples. However, these studies did not examine the effect of individual differences between the same kinds of food. Here we elucidate whether luminance distribution would continue to have a significant effect on visual freshness perception even if visual stimuli included individual differences in addition to the degradation process of foods. We took pictures of the degradation of three fishes over 3.29 hours in a controlled environment, then cropped square patches of their eyes from the original images as visual stimuli. Eleven participants performed paired comparison tests judging the visual freshness of the fish eyes at three points of degradation. Perceived freshness scores (PFS) were calculated using the Bradley-Terry Model for each image. The ANOVA revealed that the PFS for each fish decreased as the degradation time increased; however, the differences in the PFS between individual fish was larger for the shorter degradation time, and smaller for the longer degradation time. A multiple linear regression analysis was conducted in order to determine the relative importance of the statistics of luminance distribution of the stimulus images in predicting PFS. The results show that standard deviation and skewness in luminance distribution have a significant influence on PFS. These results show that even if foodstuffs contain individual differences, visual freshness perception and changes in luminance distribution correlate with degradation time.
7. Measurement of luminance noise and chromaticity noise of LCDs with a colorimeter and a color camera
Science.gov (United States)
Roehrig, H.; Dallas, W. J.; Krupinski, E. A.; Redford, Gary R.
2007-09-01
This communication focuses on physical evaluation of image quality of displays for applications in medical imaging. In particular we were interested in luminance noise as well as chromaticity noise of LCDs. Luminance noise has been encountered in the study of monochrome LCDs for some time, but chromaticity noise is a new type of noise which has been encountered first when monochrome and color LCDs were compared in an ROC study. In this present study one color and one monochrome 3 M-pixel LCDs were studied. Both were DICOM calibrated with equal dynamic range. We used a Konica Minolta Chroma Meter CS-200 as well as a Foveon color camera to estimate luminance and chrominance variations of the displays. We also used a simulation experiment to estimate luminance noise. The measurements with the colorimeter were consistent. The measurements with the Foveon color camera were very preliminary as color cameras had never been used for image quality measurements. However they were extremely promising. The measurements with the colorimeter and the simulation results showed that the luminance and chromaticity noise of the color LCD were larger than that of the monochrome LCD. Under the condition that an adequate calibration method and image QA/QC program for color displays are available, we expect color LCDs may be ready for radiology in very near future.
8. Luminance gradient at object borders communicates object location to the human oculomotor system.
Science.gov (United States)
Kilpeläinen, Markku; Georgeson, Mark A
2018-01-25
The locations of objects in our environment constitute arguably the most important piece of information our visual system must convey to facilitate successful visually guided behaviour. However, the relevant objects are usually not point-like and do not have one unique location attribute. Relatively little is known about how the visual system represents the location of such large objects as visual processing is, both on neural and perceptual level, highly edge dominated. In this study, human observers made saccades to the centres of luminance defined squares (width 4 deg), which appeared at random locations (8 deg eccentricity). The phase structure of the square was manipulated such that the points of maximum luminance gradient at the square's edges shifted from trial to trial. The average saccade endpoints of all subjects followed those shifts in remarkable quantitative agreement. Further experiments showed that the shifts were caused by the edge manipulations, not by changes in luminance structure near the centre of the square or outside the square. We conclude that the human visual system programs saccades to large luminance defined square objects based on edge locations derived from the points of maximum luminance gradients at the square's edges.
9. The effects of luminance contribution from large fields to chromatic visual evoked potentials.
Science.gov (United States)
Skiba, Rafal M; Duncan, Chad S; Crognale, Michael A
2014-02-01
Though useful from a clinical and practical standpoint uniform, large-field chromatic stimuli are likely to contain luminance contributions from retinal inhomogeneities. Such contribution can significantly influence psychophysical thresholds. However, the degree to which small luminance artifacts influence the chromatic VEP has been debated. In particular, claims have been made that band-pass tuning observed in chromatic VEPs result from luminance intrusion. However, there has been no direct evidence presented to support these claims. Recently, large-field isoluminant stimuli have been developed to control for intrusion from retinal inhomogeneities with particular regard to the influence of macular pigment. We report here the application of an improved version of these full-field stimuli to directly test the influence of luminance intrusion on the temporal tuning of the chromatic VEP. Our results show that band-pass tuning persists even when isoluminance is achieved throughout the extent of the stimulus. In addition, small amounts of luminance intrusion affect neither the shape of the temporal tuning function nor the major components of the VEP. These results support the conclusion that the chromatic VEP can depart substantially from threshold psychophysics with regard to temporal tuning and that obtaining a low-pass function is not requisite evidence of selective chromatic activation in the VEP. Copyright © 2013 Elsevier Ltd. All rights reserved.
10. Characteristics of estrogen-induced peroxidase in mouse uterine luminal fluid
International Nuclear Information System (INIS)
Jellinck, P.H.; Newbold, R.R.; McLachlan, J.A.
1991-01-01
Peroxidase activity in the uterine luminal fluid of mice treated with diethylstilbestrol was measured by the guaiacol assay and also by the formation of 3H2O from [2-3H]estradiol. In the radiometric assay, the generation of 3H2O and 3H-labeled water-soluble products was dependent on H2O2 (25 to 100 microM), with higher concentrations being inhibitory. Tyrosine or 2,4-dichlorophenol strongly enhanced the reaction catalyzed either by the luminal fluid peroxidase or the enzyme in the CaCl2 extract of the uterus, but decreased the formation of 3H2O from [2-3H]estradiol by lactoperoxidase in the presence of H2O2 (80 microM). NADPH, ascorbate, and cytochrome c inhibited both luminal fluid and uterine tissue peroxidase activity to the same extent, while superoxide dismutase showed a marginal activating effect. Lactoferrin, a major protein component of uterine luminal fluid, was shown not to contribute to its peroxidative activity, and such an effect by prostaglandin synthase was also ruled out. However, it was not possible to exclude eosinophil peroxidase, brought to the uterus after estrogen stimulation, as being the source of peroxidase activity in uterine luminal fluid
11. Quirks of dye nomenclature. 1. Evans blue.
Science.gov (United States)
Cooksey, C J
2014-02-01
The history, origin, identity, chemistry and use of Evans blue dye are described along with the first application to staining by Herbert McLean Evans in 1914. In the 1930s, the dye was marketed under the name, Evans blue dye, which was profoundly more acceptable than the ponderous chemical name.
12. Blue jay attacks and consumes cedar waxwing
Science.gov (United States)
Daniel Saenz; Joshua B. Pierce
2009-01-01
Blue Jays (Cyanocitta cristata) are known to be common predators on bird nests (Wilcove 1985, Picman and Schriml 1994). In addition to predation on eggs and nestlings, Blue Jays occasionally prey on fledgling and adult birds (Johnson and Johnson 1976, Dubowy 1985). A majority of reports involve predation on House Sparrows (Passer domesticus) and other small birds (...
13. The secret of the blue fog
Science.gov (United States)
Henrich, Oliver; Marenduzzo, Davide
2017-04-01
Why certain liquids turn blue when cooled was a mystery that stumped scientists for more than a century. As Oliver Henrich and Davide Marenduzzo explain, solving the secret of the “blue fog” proved to be an intellectual tour de force - and one that could lead to new types of display devices
14. Layer-by-layer assembly of multicolored semiconductor quantum dots towards efficient blue, green, red and full color optical films
International Nuclear Information System (INIS)
Zhang Jun; Li Qian; Di Xiaowei; Liu Zhiliang; Xu Gang
2008-01-01
Multicolored semiconductor quantum dots have shown great promise for construction of miniaturized light-emitting diodes with compact size, low weight and cost, and high luminescent efficiency. The unique size-dependent luminescent property of quantum dots offers the feasibility of constructing single-color or full-color output light-emitting diodes with one type of material. In this paper, we have demonstrated the facile fabrication of blue-, green-, red- and full-color-emitting semiconductor quantum dot optical films via a layer-by-layer assembly technique. The optical films were constructed by alternative deposition of different colored quantum dots with a series of oppositely charged species, in particular, the new use of cationic starch on glass substrates. Semiconductor ZnSe quantum dots exhibiting blue emission were deposited for fabrication of blue-emitting optical films, while semiconductor CdTe quantum dots with green and red emission were utilized for construction of green- and red-emitting optical films. The assembly of integrated blue, green and red semiconductor quantum dots resulted in full-color-emitting optical films. The luminescent optical films showed very bright emitting colors under UV irradiation, and displayed dense, smooth and efficient luminous features, showing brighter luminescence in comparison with their corresponding quantum dot aqueous colloid solutions. The assembled optical films provide the prospect of miniaturized light-emitting-diode applications.
15. The design of red-blue 3D video fusion system based on DM642
Science.gov (United States)
Fu, Rongguo; Luo, Hao; Lv, Jin; Feng, Shu; Wei, Yifang; Zhang, Hao
2016-10-01
Aiming at the uncertainty of traditional 3D video capturing including camera focal lengths, distance and angle parameters between two cameras, a red-blue 3D video fusion system based on DM642 hardware processing platform is designed with the parallel optical axis. In view of the brightness reduction of traditional 3D video, the brightness enhancement algorithm based on human visual characteristics is proposed and the luminance component processing method based on YCbCr color space is also proposed. The BIOS real-time operating system is used to improve the real-time performance. The video processing circuit with the core of DM642 enhances the brightness of the images, then converts the video signals of YCbCr to RGB and extracts the R component from one camera, so does the other video and G, B component are extracted synchronously, outputs 3D fusion images finally. The real-time adjustments such as translation and scaling of the two color components are realized through the serial communication between the VC software and BIOS. The system with the method of adding red-blue components reduces the lost of the chrominance components and makes the picture color saturation reduce to more than 95% of the original. Enhancement algorithm after optimization to reduce the amount of data fusion in the processing of video is used to reduce the fusion time and watching effect is improved. Experimental results show that the system can capture images in near distance, output red-blue 3D video and presents the nice experiences to the audience wearing red-blue glasses.
16. The time course of color- and luminance-based salience effects.
Directory of Open Access Journals (Sweden)
Isabel C Dombrowe
2010-11-01
Full Text Available Salient objects in the visual field attract our attention. Recent work in the orientation domain has shown that the effects of the relative salience of two singleton elements on covert visual attention disappear over time. The present study aims to investigate how salience derived from color and luminance differences affects covert selection. In two experiments, observers indicated the location of a probe which was presented at different stimulus-onset-asynchronies after the presentation of a singleton display containing a homogeneous array of oriented lines and two distinct color singletons (Experiment 1 or luminance singletons (Experiment 2. The results show that relative singleton salience from luminance and color differences, just as from orientation differences, affects covert visual attention in a brief time span after stimulus onset. The mere presence of an object, however, can affect covert attention for a longer time span regardless of salience.
17. Luminous quasars do not live in the most overdense regions of galaxies at z ˜ 4
Science.gov (United States)
Uchiyama, Hisakazu; Toshikawa, Jun; Kashikawa, Nobunari; Overzier, Roderik; Chiang, Yi-Kuan; Marinello, Murilo; Tanaka, Masayuki; Niino, Yuu; Ishikawa, Shogo; Onoue, Masafusa; Ichikawa, Kohei; Akiyama, Masayuki; Coupon, Jean; Harikane, Yuichi; Imanishi, Masatoshi; Kodama, Tadayuki; Komiyama, Yutaka; Lee, Chien-Hsiu; Lin, Yen-Ting; Miyazaki, Satoshi; Nagao, Tohru; Nishizawa, Atsushi J.; Ono, Yoshiaki; Ouchi, Masami; Wang, Shiang-Yu
2018-01-01
We present the cross-correlation between 151 luminous quasars (MUV 4 σ. The distributions of the distances between quasars and the nearest protoclusters and the significance of the overdensity at the positions of quasars are statistically identical to those found for g-dropout galaxies, suggesting that quasars tend to reside in almost the same environment as star-forming galaxies at this redshift. Using stacking analysis, we find that the average density of g-dropout galaxies around quasars is slightly higher than that around g-dropout galaxies on 1.0-2.5 pMpc scales, while at anti-correlated with overdensity. These findings are consistent with a scenario in which luminous quasars at z ˜ 4 reside in structures that are less massive than those expected for the progenitors of today's rich clusters of galaxies, and possibly that luminous quasars may be suppressing star formation in their close vicinity.
18. Luminance and image quality analysis of an organic electroluminescent panel with a patterned microlens array attachment
International Nuclear Information System (INIS)
Lin, Hoang Yan; Chen, Kuan-Yu; Ho, Yu-Hsuan; Fang, Jheng-Hao; Hsu, Sheng-Chih; Lee, Jiun-Haw; Lin, Jia-Rong; Wei, Mao-Kuo
2010-01-01
Luminance and image quality observed from the normal direction of a commercial 2.0 inch panel based on organic electroluminescence (OEL) technology attached to regular and patterned microlens array films (MAFs) were studied and analyzed. When applying the regularly arranged MAF on the panel, a luminance enhancement of 23% was observed, accompanied by a reduction of the image quality index as low as 74%. By removing the microlenses on the emitting areas, the patterned MAF enhances the luminance efficiency of the OEL by 52% keeping the image quality index of the display as high as 94%, due to the effective light extraction in the glass substrate being less than the critical angle. 3D simulation based on a ray-tracing model was also established to investigate the spatial distribution of light rays radiated from an OEL pixel with different microstructures which showed consistent results with the experimental results
19. Observations of Ultra-Luminous X-ray Sources, and Implications
Science.gov (United States)
Colbert, E. J. M.
2004-05-01
I will review observations of Ultra-Luminous X-ray Sources (ULXs; Lx > 1E39 erg/s), in particular those observations that have helped reveal the nature of these curious objects. Some recent observations suggest that ULXs are a heterogenous class. Although ULX phenomenology is not fully understood, I will present some examples from the (possibly overlapping) sub-classes. Since ULXs are the most luminous objects in starburst galaxies, they, and normal'' luminous black-hole high-mass X-ray binaries are intimately tied to the global galaxian X-ray-star-formation connection. Further work is needed to understand how ULXs form, and how they are associated with the putative population of intermediate-mass black holes.
20. Environmental radioactive monitoring, evaluation and protection in luminous workshops of a factory
International Nuclear Information System (INIS)
Dai Hanbin; Xiang Ming; Tan Jianzu
2009-01-01
Fluorescent technique is often used to display instrumental indicator in the dark environment. Luminous workshops of a factory smear and depict the glassware by means of fluorescent power with adulterated radioactive matter. Because of adulterated radioactive matters such as 226 Ra, 40 K emit alpha-ray,beta-ray and gamma-ray, while they decay spontaneously, and high dose or cumulative radiation can damage human body in different degrees. Therefore, any radioactive damage to human body caused by over-safety dose should be prevented strictly during the working. To ensure health and safety of working staff in luminous workshop and the public, it is necessary to regularly have radioactive monitoring and evaluation to luminous workshop and its surrounding environment. Through the environment radioactive monitoring, the authors analyze its environmental radioactive level,and try to find out the possible problems so as to propose some protective measures for personal health. (authors)
1. High-protein diet modifies colonic microbiota and luminal environment but not colonocyte metabolism in the rat model: the increased luminal bulk connection.
Science.gov (United States)
Liu, Xinxin; Blouin, Jean-Marc; Santacruz, Arlette; Lan, Annaïg; Andriamihaja, Mireille; Wilkanowicz, Sabina; Benetti, Pierre-Henri; Tomé, Daniel; Sanz, Yolanda; Blachier, François; Davila, Anne-Marie
2014-08-15
High-protein diets are used for body weight reduction, but consequences on the large intestine ecosystem are poorly known. Here, rats were fed for 15 days with either a normoproteic diet (NP, 14% protein) or a hyperproteic-hypoglucidic isocaloric diet (HP, 53% protein). Cecum and colon were recovered for analysis. Short- and branched-chain fatty acids, as well as lactate, succinate, formate, and ethanol contents, were markedly increased in the colonic luminal contents of HP rats (P diet, whereas the amount of butyrate in feces was increased (P diet consumption allows maintenance in the luminal butyrate concentration and thus its metabolism in colonocytes despite modified microbiota composition and increased substrate availability. Copyright © 2014 the American Physiological Society.
2. GREEN PEA GALAXIES AND COHORTS: LUMINOUS COMPACT EMISSION-LINE GALAXIES IN THE SLOAN DIGITAL SKY SURVEY
International Nuclear Information System (INIS)
Izotov, Yuri I.; Guseva, Natalia G.; Thuan, Trinh X.
2011-01-01
We present a large sample of 803 star-forming luminous compact galaxies (LCGs) in the redshift range z = 0.02-0.63, selected from Data Release 7 of the Sloan Digital Sky Survey (SDSS). The global properties of these galaxies are similar to those of the so-called green pea star-forming galaxies in the redshift range z = 0.112-0.360 and selected from the SDSS on the basis of their green color and compact structure. In contrast to green pea galaxies, our LCGs are selected on the basis of both their spectroscopic and photometric properties, resulting in a ∼10 times larger sample, with galaxies spanning a redshift range ∼>2 times larger. We find that the oxygen abundances and the heavy element abundance ratios in LCGs do not differ from those of nearby low-metallicity blue compact dwarf galaxies. The median stellar mass of LCGs is ∼10 9 M sun . However, for galaxies with high EW(Hβ), ≥ 100 A, it is only ∼7 x 10 8 M sun . The star formation rate in LCGs varies in the large range of 0.7-60 M sun yr -1 , with a median value of ∼4 M sun yr -1 , a factor of ∼3 lower than in high-redshift star-forming galaxies at z ∼> 3. The specific star formation rates in LCGs are extremely high and vary in the range ∼10 -9 -10 -7 yr -1 , comparable to those derived in high-redshift galaxies.
3. Optimal combination of illusory and luminance-defined 3-D surfaces: A role for ambiguity.
Science.gov (United States)
Hartle, Brittney; Wilcox, Laurie M; Murray, Richard F
2018-04-01
The shape of the illusory surface in stereoscopic Kanizsa figures is determined by the interpolation of depth from the luminance edges of adjacent inducing elements. Despite ambiguity in the position of illusory boundaries, observers reliably perceive a coherent three-dimensional (3-D) surface. However, this ambiguity may contribute additional uncertainty to the depth percept beyond what is expected from measurement noise alone. We evaluated the intrinsic ambiguity of illusory boundaries by using a cue-combination paradigm to measure the reliability of depth percepts elicited by stereoscopic illusory surfaces. We assessed the accuracy and precision of depth percepts using 3-D Kanizsa figures relative to luminance-defined surfaces. The location of the surface peak was defined by illusory boundaries, luminance-defined edges, or both. Accuracy and precision were assessed using a depth-discrimination paradigm. A maximum likelihood linear cue combination model was used to evaluate the relative contribution of illusory and luminance-defined signals to the perceived depth of the combined surface. Our analysis showed that the standard deviation of depth estimates was consistent with an optimal cue combination model, but the points of subjective equality indicated that observers consistently underweighted the contribution of illusory boundaries. This systematic underweighting may reflect a combination rule that attributes additional intrinsic ambiguity to the location of the illusory boundary. Although previous studies show that illusory and luminance-defined contours share many perceptual similarities, our model suggests that ambiguity plays a larger role in the perceptual representation of illusory contours than of luminance-defined contours.
4. SPECIFIC CHARACTERISTICS OF BRAIN METASTASIZING IN PATIENTS WITH LUMINAL SUBTYPE OF BREAST CANCER
Directory of Open Access Journals (Sweden)
A. S. Balkanov
2016-01-01
Full Text Available Background: More than half of female patients with breast cancer are diagnosed with a luminal subtype of the disease; however, specific characteristics of its metastases to the brain have been not well studied, unlike those of HER2 positive and triple negative subtypes. Aim: A comparative analysis of characteristics of metastatic brain lesions in patients with luminal breast cancer. Materials and methods: The time from surgery for breast cancer to the first recurrence and to metastatic brain lesions (assessed by contrast-enhanced MRI imaging was measured in 41 patients with luminal subtype of breast cancer (median age, 49.5±9.6 years, depending on a diameter of the primary tumor and numbers of involved axillary lymph nodes. Results: The time interval to occurrence of brain metastases in luminal subtype of breast cancer is not associated with the size of the tumor. If≥4 axillary lymph nodes are involved (N2–3, brain metastases are identified much earlier (p<0.05 than in patients with N0–1 (34.5±23.9 months and 62.7±50 months, respectively. Neither the size nor the involvement of axillary lymph nodes has any impact on the rates of metastatic lesion to the brain during the first recurrence. Conclusion: Brain metastases occur at a much shorter time in those patients of luminal subtype of breast cancer who have metastases in≥4 axillary lymph nodes. Brain metastases develop in 50% of patients with the first recurrence of the luminal subtype of breast cancer.
5. ["Glare vision". I. Physiological principles of vision change with increased test field luminance].
Science.gov (United States)
Hauser, B; Ochsner, H; Zrenner, E
1992-02-01
Clinical tests of visual acuity are an important measure of visual function. However visual acuity is usually determined only in narrow range of luminance levels between 160 and 320 cd/m2; therefore losses of visual acuity in other ranges of light intensity can not be detected. In a distance of 80 cm from the patients eyes, Landolt rings of varying sizes were presented on a small test field whose light intensity can be varied between 0.1 and 30,000 cd/m2. Thereby an acuity-luminance-function can be obtained. We studied such functions under different conditions of exposure time both with constant and with increasing luminance of the test field. We found that persons with normal vision can increase their visual acuity with increasing test field luminance up to a range of 5000 cd/m2. The maximum values of visual acuity under optimal lightening conditions lie (varying with age) between 2.2 and 0.9. Under pathological conditions visual acuity falls at high luminances accompanied by sensations of glare. Tests of glare sensitivity as a function of exposure time showed 4 sec to be a critical time of exposure since after 4 sec normal persons just reach their maximum visual acuity at high luminances. The underlying physiological mechanisms lead us to suppose that patients with neuronal light adaptation disturbances display a greater visual loss as a result of decreased time of exposure than those with disturbances in the ocular media. Visual acuity as well as the capacity to increase the patients visual acuity under optimal conditions of lighting were both found to be strongly age-dependent.(ABSTRACT TRUNCATED AT 250 WORDS)
6. Tapered photonic crystal fibers for blue-enhanced supercontinuum generation
DEFF Research Database (Denmark)
Møller, Uffe; Sørensen, Simon Toft; Larsen, Casper
2012-01-01
Tapering of photonic crystal fibers is an effective way of shifting the blue edge of a supercontinuum spectrum down in the deep-blue. We discuss the optimum taper profile for enhancing the power in the blue edge....
7. Immunoelectron microscopic localisation of keratin and luminal epithelial antigens in normal and neoplastic urothelium.
Science.gov (United States)
Wilson, P D; Nathrath, W B; Trejdosiewicz, L K
1982-01-01
Immunoelectron microscope cytochemistry was carried out on 2% paraformaldehyde fixed, 50 mu sections of normal urothelium and bladder carcinoma cells in culture using antisera raised in rabbits to human 40-63 000 MW epidermal "broad spectrum" keratin and calf urothelial "luminal epithelial antigen" (aLEA) Both the unconjugated and indirect immunoperoxidase-DAB techniques were used before routine embedding. The localisation of both keratin and luminal epithelial antigen (LEA) was similar in normal and neoplastic cells and reaction product was associated not only with tonofilaments but also lining membrane vesicles and on fine filaments in the cytoplasmic ground substance.
8. Prognostic Significance of Progesterone Receptor–Positive Tumor Cells Within Immunohistochemically Defined Luminal A Breast Cancer
Science.gov (United States)
Prat, Aleix; Cheang, Maggie Chon U.; Martín, Miguel; Parker, Joel S.; Carrasco, Eva; Caballero, Rosalía; Tyldesley, Scott; Gelmon, Karen; Bernard, Philip S.; Nielsen, Torsten O.; Perou, Charles M.
2013-01-01
Purpose Current immunohistochemical (IHC)-based definitions of luminal A and B breast cancers are imperfect when compared with multigene expression-based assays. In this study, we sought to improve the IHC subtyping by examining the pathologic and gene expression characteristics of genomically defined luminal A and B subtypes. Patients and Methods Gene expression and pathologic features were collected from primary tumors across five independent cohorts: British Columbia Cancer Agency (BCCA) tamoxifen-treated only, Grupo Español de Investigación en Cáncer de Mama 9906 trial, BCCA no systemic treatment cohort, PAM50 microarray training data set, and a combined publicly available microarray data set. Optimal cutoffs of percentage of progesterone receptor (PR) –positive tumor cells to predict survival were derived and independently tested. Multivariable Cox models were used to test the prognostic significance. Results Clinicopathologic comparisons among luminal A and B subtypes consistently identified higher rates of PR positivity, human epidermal growth factor receptor 2 (HER2) negativity, and histologic grade 1 in luminal A tumors. Quantitative PR gene and protein expression were also found to be significantly higher in luminal A tumors. An empiric cutoff of more than 20% of PR-positive tumor cells was statistically chosen and proved significant for predicting survival differences within IHC-defined luminal A tumors independently of endocrine therapy administration. Finally, no additional prognostic value within hormonal receptor (HR) –positive/HER2-negative disease was observed with the use of the IHC4 score when intrinsic IHC-based subtypes were used that included the more than 20% PR-positive tumor cells and vice versa. Conclusion Semiquantitative IHC expression of PR adds prognostic value within the current IHC-based luminal A definition by improving the identification of good outcome breast cancers. The new proposed IHC-based definition of luminal A
9. The most luminous type 2 Active Galactic Nuclei of the Swift/ BAT catalog : Are they different?
Science.gov (United States)
Baer, Rudolf Erik; Oh, Kyuseok; Koss, Michael; Wong, Ivy; Schawinski, Kevin
2018-01-01
We present an analysis of the most luminous obscured AGN of the Swift/BAT 70 month catalog, which is based on an all-sky survey in the 14 – 195 keV energy range. This survey identified 838 AGN. Excluding Blazars and AGN close ( |gb| BAT 70 month catalog and from a specific observation campaign in order to analyze the relationship of their luminosity to black hole mass and their Eddington ratios. We discuss whether these most luminous type 2 AGN have common characteristics, which differentiate them from all the type 2 AGN in the 70 month catalog.
10. Endoscopic visualization of luminal organ and great vessels with three dimensional CT scanner
International Nuclear Information System (INIS)
Kobayashi, Hisashi; Okumura, Toshiyuki; Amemiya, Ryuta; Hasegawa, Hiroshi
1992-01-01
Thirty cases examined by three dimensional CT scanner (3DCT) are reported. The observation of inner view using 3DCT were performed in 12 large vessels with vascular disorder, 10 pulmonary bronchi with lung cancer and 8 common bile ducts involved obstructive disease. In order to visualize interface of the lumen, a new software, which was developed by HITACHI MEDICO Inc., was used. In all cases but one the inner view of the luminal organ was clearly demonstrated as 3D images and it was possible to judge some changes of luminal interface involved by the diseases. The 3DCT endoscopic image might be useful as a new endoscopic technique without fiberscopy. (author)
11. Classification of radioactive self-luminous light sources - approved 1975. NBS Handbook 116
International Nuclear Information System (INIS)
Anon.
1977-01-01
The standard establishes the classification of certain radioactive self-luminous light sources according to radionuclide, type of source, activity, and performance requirements. The objectives are to establish minimum prototype testing requirements for radioactive self-luminous light sources, to promote uniformity of marking such sources, and to establish minimum physical performance for such sources. The standard is primarily directed toward assuring adequate containment of the radioactive material. Testing procedures and classification designations are specified for discoloration, temperature, thermal shock, reduced pressure, impact, vibration, and immersion. A range of test requirements is presented according to intended usage and source activity
12. Light production in the luminous fishes Photoblepharon and Anomalops from the Banda Islands.
Science.gov (United States)
Haneda, Y; Tsuji, F I
1971-07-09
The unresolved mechanism of light production in Photoblepharon and Anomalops has been reinvestigated in fresh and preserved material. Based on biochemical evidence obtained with emulsions and cell-free extracts of the organs, especially the stimulation of light with reduced flavin mononucleotide, and on electron microscopy of organ sections showing the presence of numerous bacteria, we conclude that the light is produced by symbiotic luminous bacteria. Because of the continuing failure to cultivate the luminous bacteria and because of their morphology, we suggest that the bacteria are of a primitive type called bacteroids.
13. Visual stimuli for the P300 brain-computer interface: a comparison of white/gray and green/blue flicker matrices.
Science.gov (United States)
Takano, Kouji; Komatsu, Tomoaki; Hata, Naoki; Nakajima, Yasoichi; Kansaku, Kenji
2009-08-01
The white/gray flicker matrix has been used as a visual stimulus for the so-called P300 brain-computer interface (BCI), but the white/gray flash stimuli might induce discomfort. In this study, we investigated the effectiveness of green/blue flicker matrices as visual stimuli. Ten able-bodied, non-trained subjects performed Alphabet Spelling (Japanese Alphabet: Hiragana) using an 8 x 10 matrix with three types of intensification/rest flicker combinations (L, luminance; C, chromatic; LC, luminance and chromatic); both online and offline performances were evaluated. The accuracy rate under the online LC condition was 80.6%. Offline analysis showed that the LC condition was associated with significantly higher accuracy than was the L or C condition (Tukey-Kramer, p < 0.05). No significant difference was observed between L and C conditions. The LC condition, which used the green/blue flicker matrix was associated with better performances in the P300 BCI. The green/blue chromatic flicker matrix can be an efficient tool for practical BCI application.
14. Can greening of aquaculture sequester blue carbon?
Science.gov (United States)
Ahmed, Nesar; Bunting, Stuart W; Glaser, Marion; Flaherty, Mark S; Diana, James S
2017-05-01
Globally, blue carbon (i.e., carbon in coastal and marine ecosystems) emissions have been seriously augmented due to the devastating effects of anthropogenic pressures on coastal ecosystems including mangrove swamps, salt marshes, and seagrass meadows. The greening of aquaculture, however, including an ecosystem approach to Integrated Aquaculture-Agriculture (IAA) and Integrated Multi-Trophic Aquaculture (IMTA) could play a significant role in reversing this trend, enhancing coastal ecosystems, and sequestering blue carbon. Ponds within IAA farming systems sequester more carbon per unit area than conventional fish ponds, natural lakes, and inland seas. The translocation of shrimp culture from mangrove swamps to offshore IMTA could reduce mangrove loss, reverse blue carbon emissions, and in turn increase storage of blue carbon through restoration of mangroves. Moreover, offshore IMTA may create a barrier to trawl fishing which in turn could help restore seagrasses and further enhance blue carbon sequestration. Seaweed and shellfish culture within IMTA could also help to sequester more blue carbon. The greening of aquaculture could face several challenges that need to be addressed in order to realize substantial benefits from enhanced blue carbon sequestration and eventually contribute to global climate change mitigation.
15. Blue objects in the field of M31
Energy Technology Data Exchange (ETDEWEB)
Romano, G [Padua Univ. (Italy). Istituto di Astronomia
1976-10-01
This paper gives the results of a photometric study of star-like blue objects Nos. 14, 15, 16, 17, and 18 discovered by Boerngen et al. (1970) in the field of M31 and of the QSO OA 33. Three of these objects - Nos. 14, 16 and 17 - exhibit variable light. No. 14 is a probable U Geminorum-star; No. 16 is a QSO and very likely also the No. 17. Finally, a candidate is suggested for the optical counterpart of OA 33.
16. Infiltrating giant cellular blue naevus.
Science.gov (United States)
Bittencourt, A L; Monteiro, D A; De Pretto, O J
2007-01-01
Cellular blue naevi (CBN) measure 1-2 cm in diameter and affect the dermis, occasionally extending into the subcutaneous fat. The case of a 14-year-old boy with a giant CBN (GCBN) involving the right half of the face, the jugal mucosa and the lower eyelid with a tumour that had infiltrated the bone and the maxillary and ethmoidal sinuses is reported. Biopsies were taken from the skin, jugal mucosa and maxillary sinus. The following markers were used in the immunohistochemical evaluation: CD34, CD56, HMB-45, anti-S100, A-103, Melan A and MIB-1. The biopsy specimens showed a biphasic pattern affecting the lower dermis, subcutaneous fat, skeletal muscle, bone, jugal mucosa and maxillary sinus, but there was no histological evidence of malignancy. The tumour cells were CD34-, CD56-, HMB45+, anti-S100+ and A-103+. Melan A was focally expressed. No positive MIB-1 cells were identified. The present case shows that GCBN may infiltrate deeply, with no evidence of malignancy.
17. Age-class separation of blue-winged ducks
Science.gov (United States)
Hohman, W.L.; Moore, J.L.; Twedt, D.J.; Mensik, John G.; Logerwell, E.
1995-01-01
and flyway differences in remigial measurements and reduced performance of age classification models as evidence of high variability in size of blue-winged ducks' remiges. Variability in remigial size of these and other small-bodied waterfowl may be related to nutrition during molt.
18. Movements of Blue Sharks (Prionace glauca) across Their Life History
Science.gov (United States)
Vandeperre, Frederic; Aires-da-Silva, Alexandre; Fontes, Jorge; Santos, Marco; Serrão Santos, Ricardo; Afonso, Pedro
2014-01-01
Spatial structuring and segregation by sex and size is considered to be an intrinsic attribute of shark populations. These spatial patterns remain poorly understood, particularly for oceanic species such as blue shark (Prionace glauca), despite its importance for the management and conservation of this highly migratory species. This study presents the results of a long-term electronic tagging experiment to investigate the migratory patterns of blue shark, to elucidate how these patterns change across its life history and to assess the existence of a nursery area in the central North Atlantic. Blue sharks belonging to different life stages (n = 34) were tracked for periods up to 952 days during which they moved extensively (up to an estimated 28.139 km), occupying large parts of the oceanic basin. Notwithstanding a large individual variability, there were pronounced differences in movements and space use across the species' life history. The study provides strong evidence for the existence of a discrete central North Atlantic nursery, where juveniles can reside for up to at least 2 years. In contrast with previously described nurseries of coastal and semi-pelagic sharks, this oceanic nursery is comparatively vast and open suggesting that shelter from predators is not its main function. Subsequently, male and female blue sharks spatially segregate. Females engage in seasonal latitudinal migrations until approaching maturity, when they undergo an ontogenic habitat shift towards tropical latitudes. In contrast, juvenile males generally expanded their range southward and apparently displayed a higher degree of behavioural polymorphism. These results provide important insights into the spatial ecology of pelagic sharks, with implications for the sustainable management of this heavily exploited shark, especially in the central North Atlantic where the presence of a nursery and the seasonal overlap and alternation of different life stages coincides with a high fishing
19. Corneal edema and permanent blue discoloration of a silicone intraocular lens by methylene blue.
Science.gov (United States)
Stevens, Scott; Werner, Liliana; Mamalis, Nick
2007-01-01
To report a silicone intraocular lens (IOL) stained blue by inadvertent intraoperative use of methylene blue instead of trypan blue and the results of experimental staining of various lens materials with different concentrations of the same dye. A "blue dye" was used to enhance visualization during capsulorhexis in a patient undergoing phacoemulsification with implantation of a three-piece silicone lens. Postoperatively, the patient presented with corneal edema and a discolored IOL. Various IOL materials were experimentally stained using methylene blue. Sixteen lenses (4 silicone, 4 hydrophobic acrylic, 4 hydrophilic acrylic, and 4 polymethylmethacrylate) were immersed in 0.5 mL of methylene blue at concentrations of 1%, 0.1%, 0.01%, and 0.001%. These lenses were grossly and microscopically evaluated for discoloration 6 and 24 hours after immersion. The corneal edema resolved within 1 month after the initial surgical procedure. After explantation, gross and microscopic analyses of the explanted silicone lens revealed that its surface and internal substance had been permanently stained blue. In the experimental study, all of the lenses except the polymethylmethacrylate lenses were permanently stained by methylene blue. The hydrophilic acrylic lenses showed the most intense blue staining in all dye concentrations. This is the first clinicopathological report of IOL discoloration due to intraocular use of methylene blue. This and other tissue dyes may be commonly found among surgical supplies in the operating room and due diligence is necessary to avoid mistaking these dyes for those commonly used during ocular surgery.
20. Non-invasive in situ Examination of Colour Changes of Blue Paints in Danish Golden Age Paintings
DEFF Research Database (Denmark)
Buti, David; Vila, Anna; Filtenborg, Troels Folke
A non-invasive study of some paintings containing areas of paint with a Prussian blue component has been conducted at the Statens Museum for Kunst. The in situ campaign has been carried out with a range of different spectroscopic portable techniques, provided by the MOLAB transnational access...... of the frame. Prussian blue is a hydrated iron(III) hexacyanoferrate(II) complex of variable composition depending on the manufacturing [1]. It has been reported that the method of preparation, as well as the use of white pigments or extenders to dilute the blue pigment, may be a factor contributing to its......, the current in situ campaign aimed at mapping and understanding the degradation of Prussian blue and lead white admixtures using non-invasive portable techniques. The presence of Prussian blue was detected, with the MOLAB analytical means, in all the exposed, faded areas, although the colour had turned pale...
1. Hybrid white organic light-emitting devices based on phosphorescent iridium-benzotriazole orange-red and fluorescent blue emitters
Energy Technology Data Exchange (ETDEWEB)
Xia, Zhen-Yuan, E-mail: xiazhenyuan@hotmail.com [Key Laboratory for Advanced Materials and Institute of Fine Chemicals, East China University of Science and Technology, Shanghai 200237 (China); Su, Jian-Hua [Key Laboratory for Advanced Materials and Institute of Fine Chemicals, East China University of Science and Technology, Shanghai 200237 (China); Chang, Chi-Sheng; Chen, Chin H. [Display Institute, Microelectronics and Information Systems Research Center, National Chiao Tung University, Hsinchu, Taiwan 300 (China)
2013-03-15
We demonstrate that high color purity or efficiency hybrid white organic light-emitting devices (OLEDs) can be generated by integrating a phosphorescent orange-red emitter, bis[4-(2H-benzotriazol-2-yl)-N,N-diphenyl-aniline-N{sup 1},C{sup 3}] iridium acetylacetonate, Ir(TBT){sub 2}(acac) with fluorescent blue emitters in two different emissive layers. The device based on deep blue fluorescent material diphenyl-[4-(2-[1,1 Prime ;4 Prime ,1 Double-Prime ]terphenyl-4-yl-vinyl)-phenyl]-amine BpSAB and Ir(TBT){sub 2}(acac) shows pure white color with the Commission Internationale de L'Eclairage (CIE) coordinates of (0.33,0.30). When using sky-blue fluorescent dopant N,N Prime -(4,4 Prime -(1E,1 Prime E)-2,2 Prime -(1,4-phenylene)bis(ethene-2,1-diyl) bis(4,1-phenylene))bis(2-ethyl-6-methyl-N-phenylaniline) (BUBD-1) and orange-red phosphor with a color-tuning phosphorescent material fac-tris(2-phenylpyridine) iridium (Ir(ppy){sub 3} ), it exhibits peak luminance yield and power efficiency of 17.4 cd/A and 10.7 lm/W, respectively with yellow-white color and CIE color rendering index (CRI) value of 73. - Highlights: Black-Right-Pointing-Pointer An iridium-based orange-red phosphor Ir(TBT){sub 2}(acac) was applied in hybrid white OLEDs. Black-Right-Pointing-Pointer Duel- and tri-emitter WOLEDs were achieved with either high color purity or efficiency performance. Black-Right-Pointing-Pointer Peak luminance yield of tri-emitter WOLEDs was 17.4 cd/A with yellow-white color and color rendering index (CRI) value of 73.
2. Efficient blue and white polymer light emitting diodes based on a well charge balanced, core modified polyfluorene derivative.
Science.gov (United States)
Das, Dipjyoti; Gopikrishna, Peddaboodi; Singh, Ashish; Dey, Anamika; Iyer, Parameswar Krishnan
2016-03-14
Fabrication of efficient blue and white polymer light-emitting diodes (PLEDs) using a well charge balanced, core modified polyfluorene derivative, poly[2,7-(9,9'-dioctylfluorene)-co-N-phenyl-1,8-naphthalimide (99:01)] (PFONPN01), is presented. The excellent film forming properties as observed from the morphological study and the enhanced electron transport properties due to the inclusion of the NPN unit in the PFO main chain resulted in improved device properties. Bright blue light was observed from single layer PLEDs with PFONPN01 as an emissive layer (EML) as well as from double layer PLEDs using tris-(8-hydroxyquinoline) aluminum (Alq3) as an electron transporting layer (ETL) and LiF/Al as a cathode. The effect of ETL thickness on the device performance was studied by varying the Alq3 thickness (5 nm, 10 nm and 20 nm) and the device with an ETL thickness of 20 nm was found to exhibit the maximum brightness value of 11 662 cd m(-2) with a maximum luminous efficiency of 4.87 cd A(-1). Further, by using this highly electroluminescent blue PFONPN01 as a host and a narrow band gap, yellow emitting small molecule, dithiophene benzothiadiazole (DBT), as a guest at three different concentrations (0.2%, 0.4% and 0.6%), WPLEDs with the ITO/PEDOT:PSS/emissive layer/Alq3(20 nm)/LiF/Al configuration were fabricated and maximum brightness values of 8025 cd m(-2), 9565 cd m(-2) and 10 180 cd m(-2) were achieved respectively. 0.4% DBT in PFONPN01 was found to give white light with Commission International de l'Echairage (CIE) coordinates of (0.31, 0.38), a maximum luminous efficiency of 6.54 cd A(-1) and a color-rendering index (CRI) value of 70.
3. Hybrid white organic light-emitting devices based on phosphorescent iridium–benzotriazole orange–red and fluorescent blue emitters
International Nuclear Information System (INIS)
Xia, Zhen-Yuan; Su, Jian-Hua; Chang, Chi-Sheng; Chen, Chin H.
2013-01-01
We demonstrate that high color purity or efficiency hybrid white organic light-emitting devices (OLEDs) can be generated by integrating a phosphorescent orange–red emitter, bis[4-(2H-benzotriazol-2-yl)-N,N-diphenyl-aniline-N 1 ,C 3 ] iridium acetylacetonate, Ir(TBT) 2 (acac) with fluorescent blue emitters in two different emissive layers. The device based on deep blue fluorescent material diphenyl-[4-(2-[1,1′;4′,1″]terphenyl-4-yl-vinyl)-phenyl]-amine BpSAB and Ir(TBT) 2 (acac) shows pure white color with the Commission Internationale de L'Eclairage (CIE) coordinates of (0.33,0.30). When using sky-blue fluorescent dopant N,N′-(4,4′-(1E,1′E)-2,2′-(1,4-phenylene)bis(ethene-2,1-diyl) bis(4,1-phenylene))bis(2-ethyl-6-methyl-N-phenylaniline) (BUBD-1) and orange–red phosphor with a color-tuning phosphorescent material fac-tris(2-phenylpyridine) iridium (Ir(ppy) 3 ), it exhibits peak luminance yield and power efficiency of 17.4 cd/A and 10.7 lm/W, respectively with yellow-white color and CIE color rendering index (CRI) value of 73. - Highlights: ► An iridium-based orange–red phosphor Ir(TBT) 2 (acac) was applied in hybrid white OLEDs. ► Duel- and tri-emitter WOLEDs were achieved with either high color purity or efficiency performance. ► Peak luminance yield of tri-emitter WOLEDs was 17.4 cd/A with yellow-white color and color rendering index (CRI) value of 73.
4. 10 CFR 32.101 - Schedule B-prototype tests for luminous safety devices for use in aircraft.
Science.gov (United States)
2010-01-01
....101 Schedule B—prototype tests for luminous safety devices for use in aircraft. An applicant for a... 10 Energy 1 2010-01-01 2010-01-01 false Schedule B-prototype tests for luminous safety devices for use in aircraft. 32.101 Section 32.101 Energy NUCLEAR REGULATORY COMMISSION SPECIFIC DOMESTIC LICENSES...
5. 10 CFR 32.22 - Self-luminous products containing tritium, krypton-85 or promethium-147: Requirements for license...
Science.gov (United States)
2010-01-01
... 10 Energy 1 2010-01-01 2010-01-01 false Self-luminous products containing tritium, krypton-85 or... containing tritium, krypton-85 or promethium-147: Requirements for license to manufacture, process, produce... self-luminous products containing tritium, krypton-85, or promethium-147, or to initially transfer such...
6. The ER stress sensor PERK luminal domain functions as a molecular chaperone to interact with misfolded proteins
Energy Technology Data Exchange (ETDEWEB)
Wang, Peng; Li, Jingzhi; Sha, Bingdong
2016-11-29
PERK is one of the major sensor proteins which can detect the protein-folding imbalance generated by endoplasmic reticulum (ER) stress. It remains unclear how the sensor protein PERK is activated by ER stress. It has been demonstrated that the PERK luminal domain can recognize and selectively interact with misfolded proteins but not native proteins. Moreover, the PERK luminal domain may function as a molecular chaperone to directly bind to and suppress the aggregation of a number of misfolded model proteins. The data strongly support the hypothesis that the PERK luminal domain can interact directly with misfolded proteins to induce ER stress signaling. To illustrate the mechanism by which the PERK luminal domain interacts with misfolded proteins, the crystal structure of the human PERK luminal domain was determined to 3.2 Å resolution. Two dimers of the PERK luminal domain constitute a tetramer in the asymmetric unit. Superimposition of the PERK luminal domain molecules indicated that the β-sandwich domain could adopt multiple conformations. It is hypothesized that the PERK luminal domain may utilize its flexible β-sandwich domain to recognize and interact with a broad range of misfolded proteins.
7. A method for evaluating image quality of monochrome and color displays based on luminance by use of a commercially available color digital camera
Energy Technology Data Exchange (ETDEWEB)
Tokurei, Shogo, E-mail: shogo.tokurei@gmail.com, E-mail: junjim@med.kyushu-u.ac.jp [Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Fukuoka 812-8582, Japan and Department of Radiology, Yamaguchi University Hospital, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505 (Japan); Morishita, Junji, E-mail: shogo.tokurei@gmail.com, E-mail: junjim@med.kyushu-u.ac.jp [Department of Health Sciences, Faculty of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Fukuoka 812-8582 (Japan)
2015-08-15
Purpose: The aim of this study is to propose a method for the quantitative evaluation of image quality of both monochrome and color liquid-crystal displays (LCDs) using a commercially available color digital camera. Methods: The intensities of the unprocessed red (R), green (G), and blue (B) signals of a camera vary depending on the spectral sensitivity of the image sensor used in the camera. For consistent evaluation of image quality for both monochrome and color LCDs, the unprocessed RGB signals of the camera were converted into gray scale signals that corresponded to the luminance of the LCD. Gray scale signals for the monochrome LCD were evaluated by using only the green channel signals of the camera. For the color LCD, the RGB signals of the camera were converted into gray scale signals by employing weighting factors (WFs) for each RGB channel. A line image displayed on the color LCD was simulated on the monochrome LCD by using a software application for subpixel driving in order to verify the WF-based conversion method. Furthermore, the results obtained by different types of commercially available color cameras and a photometric camera were compared to examine the consistency of the authors’ method. Finally, image quality for both the monochrome and color LCDs was assessed by measuring modulation transfer functions (MTFs) and Wiener spectra (WS). Results: The authors’ results demonstrated that the proposed method for calibrating the spectral sensitivity of the camera resulted in a consistent and reliable evaluation of the luminance of monochrome and color LCDs. The MTFs and WS showed different characteristics for the two LCD types owing to difference in the subpixel structure. The MTF in the vertical direction of the color LCD was superior to that of the monochrome LCD, although the WS in the vertical direction of the color LCD was inferior to that of the monochrome LCD as a result of luminance fluctuations in RGB subpixels. Conclusions: The authors
8. Substantial Research Secures the Blue Future for our Blue Plant
Directory of Open Access Journals (Sweden)
Moustafa Abdel Maksoud
2016-06-01
Full Text Available Earth, the blue planet, is our home, and seas and oceans cover more than 70% of its surface. As the earth’s population rapidly increases and available resources decrease, seas and oceans can play a key role in assuring the long-term survival of humankind. Renewable maritime energy has huge potential to provide a considerable part of the earth’s population with decarbonised electricity generation systems. Renewable maritime energy is very flexible and can be harvested above the water’s free surface by using offshore wind turbines, on the water’s surface by using wave energy converters or below the water’s surface by using current or tidal turbines. The supposed conflict between environmental protection measures and economic interests is neither viable nor reasonable. Renewable maritime energy can be the motor for considerable substantial economic growth for many maritime regions and therefore for society at large. The fastest growing sector of renewable maritime energy is offshore wind. The annual report of the European Wind Energy Association from the year 2015 confirms the growing relevance of the offshore wind industry. In 2015, the total installed and grid-connected capacity of wind power was 12,800 MW in the EU and 6,013.4 MW in Germany. 38% of the 2015 annual installation in Germany was offshore, accounting for a capacity of 2,282.4 MW. However, there are a limited number of available installation sites in shallow water, meaning that there is an urgent need to develop new offshore structures for water depths greater than 50m. The persistent trend towards deeper waters has encouraged the offshore wind industry to look for floating wind turbine structures and larger turbines. Floating wind turbine technologies are at an early stage of development and many technical and economic challenges will still need to be faced. Nonetheless, intensive research activities and the employment of advanced technologies are the key factors in
9. High-luminosity blue and blue-green gallium nitride light-emitting diodes.
Science.gov (United States)
1995-01-06
Compact and efficient sources of blue light for full color display applications and lighting eluded and tantalized researchers for many years. Semiconductor light sources are attractive owing to their reliability and amenability to mass manufacture. However, large band gaps are required to achieve blue color. A class of compound semiconductors formed by metal nitrides, GaN and its allied compounds AIGaN and InGaN, exhibits properties well suited for not only blue and blue-green emitters, but also for ultraviolet emitters and detectors. What thwarted engineers and scientists from fabricating useful devices from these materials in the past was the poor quality of material and lack of p-type doping. Both of these obstacles have recently been overcome to the point where highluminosity blue and blue-green light-emitting diodes are now available in the marketplace.
10. Contributions of contour frequency, amplitude, and luminance to the watercolor effect estimated by conjoint measurement.
Science.gov (United States)
Gerardin, Peggy; Devinck, Frédéric; Dojat, Michel; Knoblauch, Kenneth
2014-04-10
The watercolor effect is a long-range, assimilative, filling-in phenomenon induced by a pair of distant, wavy contours of different chromaticities. Here, we measured joint influences of the contour frequency and amplitude and the luminance of the interior contour on the strength of the effect. Contour pairs, each enclosing a circular region, were presented with two of the dimensions varying independently across trials (luminance/frequency, luminance/amplitude, frequency/amplitude) in a conjoint measurement paradigm (Luce & Tukey, 1964). In each trial, observers judged which of the stimuli evoked the strongest fill-in color. Control stimuli were identical except that the contours were intertwined and generated little filling-in. Perceptual scales were estimated by a maximum likelihood method (Ho, Landy, & Maloney, 2008). An additive model accounted for the joint contributions of any pair of dimensions. As shown previously using difference scaling (Devinck & Knoblauch, 2012), the strength increases with luminance of the interior contour. The strength of the phenomenon was nearly independent of the amplitude of modulation of the contour but increased with its frequency up to an asymptotic level. On average, the strength of the effect was similar along a given dimension regardless of the other dimension with which it was paired, demonstrating consistency of the underlying estimated perceptual scales.
11. Dynamic contrast-enhanced MRI in patients with luminal Crohn's disease
NARCIS (Netherlands)
Ziech, M. L. W.; Lavini, C.; Caan, M. W. A.; Nio, C. Y.; Stokkers, P. C. F.; Bipat, S.; Ponsioen, C. Y.; Nederveen, A. J.; Stoker, J.
2012-01-01
Objectives: To prospectively assess dynamic contrast-enhanced (DCE-)MRI as compared to conventional sequences in patients with luminal Crohn's disease. Methods: Patients with Crohn's disease undergoing MRI and ileocolonoscopy within 1 month had DCE-MRI (3T) during intravenous contrast injection of
12. A Semi-Automatic, Remote-Controlled Video Observation System for Transient Luminous Events
DEFF Research Database (Denmark)
Allin, Thomas Højgaard; Neubert, Torsten; Laursen, Steen
2003-01-01
In support for global ELF/VLF observations, HF measurements in France, and conjugate photometry/VLF observations in South Africa, we developed and operated a semi-automatic, remotely controlled video system for the observation of middle-atmospheric transient luminous events (TLEs). Installed...
13. The galactic luminous supersoft X-ray source RXJ0925.7-4758 / MR ...
Nandita Prodhani
2018-01-30
Jan 30, 2018 ... White dwarf; luminous supersoft X-ray source; luminosity; absorption edge. PACS Nos 97.80.Jp; 97.10.Ri; 98.35.Mp; 97.80.Fk. 1. Introduction. For the last few decades, Einstein observatory, Roent- gen Satellite (ROSAT), ASCA, CHANDRA, XMM-. Newton, SWIFT, SUZAKU and other ingenious devices.
14. 78 FR 29391 - Luminant Generation Company, LLC; Combined License Application for Comanche Peak Nuclear Power...
Science.gov (United States)
2013-05-20
... only temporary relief from the applicable regulation and the licensee has made good faith efforts to... only temporary relief from the regulations of 10 CFR 50.71(e)(3)(iii). Luminant has made good faith... applicable regulation and the licensee has made good faith efforts to comply with the regulation'' (10 CFR 50...
15. Maturation of polarization and luminance contrast sensitivities in cuttlefish (Sepia officinalis).
Science.gov (United States)
Cartron, Lelia; Dickel, Ludovic; Shashar, Nadav; Darmaillacq, Anne-Sophie
2013-06-01
Polarization sensitivity is a characteristic of the visual system of cephalopods. It has been well documented in adult cuttlefish, which use polarization sensitivity in a large range of tasks such as communication, orientation and predation. Because cuttlefish do not benefit from parental care, their visual system (including the ability to detect motion) must be efficient from hatching to enable them to detect prey or predators. We studied the maturation and functionality of polarization sensitivity in newly hatched cuttlefish. In a first experiment, we examined the response of juvenile cuttlefish from hatching to the age of 1 month towards a moving, vertically oriented grating (contrasting and polarized stripes) using an optomotor response apparatus. Cuttlefish showed differences in maturation of polarization versus luminance contrast motion detection. In a second experiment, we examined the involvement of polarization information in prey preference and detection in cuttlefish of the same age. Cuttlefish preferentially chose not to attack transparent prey whose polarization contrast had been removed with a depolarizing filter. Performances of prey detection based on luminance contrast improved with age. Polarization contrast can help cuttlefish detect transparent prey. Our results suggest that polarization is not a simple modulation of luminance information, but rather that it is processed as a distinct channel of visual information. Both luminance and polarization sensitivity are functional, though not fully matured, in newly hatched cuttlefish and seem to help in prey detection.
16. Modulation of visual cortical excitability by working memory: effect of luminance contrast of mental imagery
Directory of Open Access Journals (Sweden)
Zaira eCattaneo
2011-02-01
Full Text Available Although much is known about the impact of stimulus properties such as luminance contrast, spatial frequency and orientation on visually evoked neural activity, much less is known about how they modulate neural activity when they are properties of a mental image held in working memory (WM. Here we addressed this question by investigating how a parametric manipulation of an imagined stimulus attribute affects neuronal excitability in the early visual cortex. We manipulated luminance contrast, a stimulus property known to strongly affect the magnitude of neuronal responses in early visual areas. Luminance contrast modulated neuronal excitability, as assessed by the frequency of phosphenes induced by transcranial magnetic stimulation (TMS with the exact nature of this modulation depending on TMS intensity. These results point to a strong overlap in the neuronal processes underlying visual perception and mental imagery: not only does WM maintenance selectively engage neurons which are tuned to the maintained attribute (as has previously been shown, but the extent to which those neurons are activated depends on the luminance contrast (as is the case with visually-evoked responses. From a methodological viewpoint, these results suggest that assessment of visual cortical excitability using TMS is affected by the TMS intensity used to probe the neuronal population.
17. Informational primacy of visual dimensions: specialized roles for luminance and chromaticity in figure-ground perception.
Science.gov (United States)
Yamagishi, N; Melara, R D
2001-07-01
Three experiments were conducted to examine the distinct contributions of two visual dimensions to figure-ground segregation. In each experiment, pattern identification was assessed by asking observers to judge whether a near-threshold test pattern was the same or different in shape to a high-contrast comparison pattern. A test pattern could differ from its background along one dimension, either luminance (luminance tasks) or chromaticity (chromaticity tasks). In each task, performance in a baseline condition, in which the test pattern was intact, was compared with performance in each of several degradation conditions, in which either the contour or the surface of the figure was degraded, using either partial occlusion (Experiment 1) or ramping (Experiments 2 and 3) of figure-ground differences. In each experiment, performance in luminance tasks was worst when the contour was degraded, whereas performance in chromaticity tasks was worst when the surface was degraded. This interaction was found even when spatial frequencies were fixed across test patterns by low-pass filtering. The results are consistent with a late (postfiltering) dual-mechanism system that processes luminance information to extract boundary representations and chromaticity information to extract surface representations.
18. Visual memory for random block patterns defined by luminance and color contrast
NARCIS (Netherlands)
Cornelissen, FW; Greenlee, MW
2000-01-01
We studied the ability of human subjects to memorize the visual information in computer-generated random block patterns defined either by luminance contrast, by color contrast, or by both. Memory performance declines rapidly with increasing inter-stimulus interval, showing a half-life of
19. Luminal Cells Are Favored as the Cell of Origin for Prostate Cancer
Directory of Open Access Journals (Sweden)
Zhu A. Wang
2014-09-01
Full Text Available The identification of cell types of origin for cancer has important implications for tumor stratification and personalized treatment. For prostate cancer, the cell of origin has been intensively studied, but it has remained unclear whether basal or luminal epithelial cells, or both, represent cells of origin under physiological conditions in vivo. Here, we use a novel lineage-tracing strategy to assess the cell of origin in a diverse range of mouse models, including Nkx3.1+/−; Pten+/−, Pten+/−, Hi-Myc, and TRAMP mice, as well as a hormonal carcinogenesis model. Our results show that luminal cells are consistently the observed cell of origin for each model in situ; however, explanted basal cells from these mice can generate tumors in grafts. Consequently, we propose that luminal cells are favored as cells of origin in many contexts, whereas basal cells only give rise to tumors after differentiation into luminal cells.
20. Defining optimal duration and predicting benefit from chemotherapy in patients with luminal-like subtypes.
Science.gov (United States)
Hart, Christopher D; Sanna, Giuseppina; Siclari, Olimpia; Biganzoli, Laura; Di Leo, Angelo
2015-11-01
The molecular subtypes of breast cancer have individual patterns of behaviour, prognosis and sensitivity to treatment, with subsequent implications for the choice of, or indeed role for adjuvant therapy. The luminal A and B subtypes make up the majority of breast cancers, but despite sharing expression of the oestrogen receptor (ER), they are molecularly distinct. It follows then that they would have different sensitivities to chemotherapy. Clinically, luminal A disease has a better prognosis than luminal B, and may not derive significant benefit from adjuvant chemotherapy. However no prospective trials have specifically investigated the benefit of adjuvant chemotherapy in each subtype, nor do we know if certain agents are more or less effective. This paper will briefly summarise the role of molecular profiles in assessing the need for chemotherapy and predicting its effectiveness, followed by an assessment of the relative value of newer anthracycline- or taxane-containing regimes in the luminal-like subtypes, providing a review of retrospective analyses. Copyright © 2015 Elsevier Ltd. All rights reserved.
1. UVB-activated psoralen reduces luminal narrowing after balloon dilation because of inhibition of constrictive remodeling
NARCIS (Netherlands)
Perrée, Jop; van Leeuwen, Ton G.; Velema, Evelyn; Smeets, Mirjam; de Kleijn, Dominique; Borst, Cornelius
2002-01-01
In this study we have explored the potential of PUVB (8-MOP + UVB) therapy for the reduction of luminal narrowing after arterial injury. In 15 rabbits, balloon dilation of iliac arteries was performed. In 20 arteries, dilation was combined with the delivery of pulsed ultraviolet light B (UVB)
2. Cloning and characterization of luciferase from a Fijian luminous click beetle.
Science.gov (United States)
Mitani, Yasuo; Futahashi, Ryo; Niwa, Kazuki; Ohba, Nobuyoshi; Ohmiya, Yoshihiro
2013-01-01
Luminous click beetle is distributed almost exclusively in Central and South America with a single genus in Melanesia. Among these click beetles, the description of Melanesian species has been fragmentary, and its luciferase gene and phylogenetic relation to other click beetles still remain uncertain. We collected a living luminous click beetle, Photophorus jansonii in Fiji. It emits green-yellow light from two spots on the pronotum and has no ventral luminous organ. Here, we cloned a luciferase gene from this insect by RT-PCR. The deduced amino acid sequence showed high identity of ~85% to the luciferases derived from other click beetle species. The luciferase of the Fijian click beetle was produced as a recombinant protein to characterize its biochemical properties. The Km for D-luciferin and ATP were 173 and 270 μm, respectively. The luciferase was pH-insensitive and the spectrum measured at pH 8.0 showed a peak at 559 nm, which was in the range of green-yellow light as seen in the luminous spot of the living Fijian click beetle. The Fijian click beetle luciferase was assigned to the Elateridae clade by a phylogenetic analysis, but it made a clearly different branch from Pyrophorus group examined in this study. © 2013 The American Society of Photobiology.
3. The Biology of blue-green algae
National Research Council Canada - National Science Library
Carr, Nicholas G; Whitton, B. A
1973-01-01
.... Their important environmental roles, their part in nitrogen fixation and the biochemistry of phototrophic metabolism are some of the attractions of blue-geen algae to an increasing number of biologists...
4. BLUES function method in computational physics
Science.gov (United States)
Indekeu, Joseph O.; Müller-Nedebock, Kristian K.
2018-04-01
We introduce a computational method in physics that goes ‘beyond linear use of equation superposition’ (BLUES). A BLUES function is defined as a solution of a nonlinear differential equation (DE) with a delta source that is at the same time a Green’s function for a related linear DE. For an arbitrary source, the BLUES function can be used to construct an exact solution to the nonlinear DE with a different, but related source. Alternatively, the BLUES function can be used to construct an approximate piecewise analytical solution to the nonlinear DE with an arbitrary source. For this alternative use the related linear DE need not be known. The method is illustrated in a few examples using analytical calculations and numerical computations. Areas for further applications are suggested.
5. Nanotubes based on monolayer blue phosphorus
KAUST Repository
Montes Muñ oz, Enrique; Schwingenschlö gl, Udo
2016-01-01
We demonstrate structural stability of monolayer zigzag and armchair blue phosphorus nanotubes by means of molecular dynamics simulations. The vibrational spectrum and electronic band structure are determined and analyzed as functions of the tube
6. What causes IOR? Attention or perception? - manipulating cue and target luminance in either blocked or mixed condition.
Science.gov (United States)
Zhao, Yuanyuan; Heinke, Dietmar
2014-12-01
Inhibition of return (IOR) refers to the performance disadvantage when detecting a target presented at a previously cued location. The current paper contributes to the long-standing debate whether IOR is caused by attentional processing or perceptual processing. We present a series of four experiments which varied the cue luminance in mixed and blocked conditions. We hypothesised that if inhibition was initialized by an attentional process the size of IOR should not vary in the blocked condition as participants should be able to adapt to the level of cue luminance. However, if a perceptual process triggers inhibition both experimental manipulations should lead to varying levels of IOR. Indeed, we found evidence for the latter hypothesis. In addition, we also varied the target luminance in blocked and mixed condition. Both manipulations, cue luminance and target luminance, affected IOR in an additive fashion suggesting that the two stimuli affect human behaviour on different processing stages. Copyright © 2014 Elsevier Ltd. All rights reserved.
7. Study on luminescence characteristics of blue OLED with phosphor-doped host-guest structure
Science.gov (United States)
Wang, Zhen; Liu, Fei; Zheng, Xin; Chen, Ai; Xie, Jia-feng; Zhang, Wen-xia
2018-05-01
In this study, we design and fabricate phosphor-doped host-guest structure organic light-emitting diodes (OLEDs), where the blue-ray iridium complex electrophosphorescent material FIrpic acts as object material. Properties of the device can be accommodated by changing the host materials, dopant concentration and thickness of the light-emitting layer. The study shows that the host material N,N'-dicarbazolyl-3,5-benzene (mCP) has a higher triplet excited state energy level, which can effectively prevent FIrpic triplet excited state energy backtracking to host material, thus the luminous efficiency is improved. When mCP is selected as the host material, the thickness of the light-emitting layer is 30 nm and the dopant concentration is 8 wt%, the excitons can be effectively confined in the light-emitting region. As a result, the maximum current efficiency and the maximum brightness of the blue device can reach 15.5 cd/A and 7 196.3 cd/m2, respectively.
8. [The spectrogram characteristics of organic blue-emissive light-emitting excitated YAG : Ce phosphor].
Science.gov (United States)
Xi, Jian-Fei; Zhang, Fang-Hui; Mu, Qiang; Zhang, Mai-Li
2011-09-01
It is demonstrated that the panchromatic luminescence devices with organic blue-emissive light-emitting was fabricated. This technique used down conversion, which was already popular in inorganic power LEDs to obtain white light emission. A blue OLED device with a configuration of ITO/2T-NATA (30 nm)/AND : TBPe (50 Wt%, 40 nm)/Alq3 (100 nm)/LiF(1 nm)/Al(100 nm) was prepared via vacuum deposition process, and then coated with YAG : Ce phosphor layers of different thicknesses to obtain a controllable and uniform shape while the CIE coordinates were fine tuned. This development not only decreased steps of technics and degree of difficulty, but also applied the mature technology of phosphor. The results showed that steady spectrogram was obtained in the devices with phosphor, with a best performance of a maximum luminance of 13 840 cd x m(-2) which was about 2 times of that of the devices without phosphor; a maximum current efficiency of 17.3 cd x A(-1) was increased more two times more than the devices without phosphor. The emission spectrum could be adjusted by varying the concentration and thickness of the phosphor layers. Absoulte spectrogram of devices was in direct proportion with different driving current corresponding.
9. Blue space geographies: Enabling health in place.
Science.gov (United States)
Foley, Ronan; Kistemann, Thomas
2015-09-01
Drawing from research on therapeutic landscapes and relationships between environment, health and wellbeing, we propose the idea of 'healthy blue space' as an important new development Complementing research on healthy green space, blue space is defined as; 'health-enabling places and spaces, where water is at the centre of a range of environments with identifiable potential for the promotion of human wellbeing'. Using theoretical ideas from emotional and relational geographies and critical understandings of salutogenesis, the value of blue space to health and wellbeing is recognised and evaluated. Six individual papers from five different countries consider how health can be enabled in mixed blue space settings. Four sub-themes; embodiment, inter-subjectivity, activity and meaning, document multiple experiences within a range of healthy blue spaces. Finally, we suggest a considerable research agenda - theoretical, methodological and applied - for future work within different forms of blue space. All are suggested as having public health policy relevance in social and public space. Copyright © 2015 Elsevier Ltd. All rights reserved.
10. Thematic Mapper Analysis of Blue Oak (Quercus douglasii) in Central California
Science.gov (United States)
Paul A. Lefebvre Jr.; Frank W. Davis; Mark Borchert
1991-01-01
Digital Thematic Mapper (TM) satellite data from September 1986 and December 1985 were analyzed to determine seasonal reflectance properties of blue oak rangeland in the La Panza mountains of San Luis Obispo County. Linear regression analysis was conducted to examine relationships between TM reflectance and oak canopy cover, basal area, and site topographic variables....
11. Effects of feeding on luminal pH and morphology of the gastroesophageal junction of snakes.
Science.gov (United States)
Bessler, Scott M; Secor, Stephen M
2012-10-01
At the gastroesophageal junction, most vertebrates possess a functional lower esophageal sphincter (LES) which may serve to regulate the passage of liquids and food into the stomach and prevent the reflux of gastric contents into the esophagus. Snakes seemingly lack an LES and consume meals large enough to extend anteriorly from the stomach into the esophagus thereby providing the opportunity for the reflux of gastric juices. To explore whether snakes experience or can prevent gastric reflux, we examined post-feeding changes of luminal pH of the distal esophagus and stomach, the fine scale luminal pH profile at the gastroesophageal junction, and the morphology of the gastroesophageal junction for the Burmese python (Python molurus), the African brown house snake (Lamprophis fuliginosus), and the diamondback water snake (Nerodia rhombifer). For each species fasted, there was no distension of the gastroesophageal junction and only modest changes in luminal pH from the distal esophagus into the stomach. Feeding resulted in marked distension and changes in tissue morphology of the gastroesophageal junction. Simultaneously, there was a significant decrease in luminal pH of the distal esophagus for pythons and house snakes, and for all three species a steep gradient in luminal pH decreasing across a 3-cm span from the distal edge of the esophagus into the proximal edge of the stomach. The moderate acidification of the distal most portion of the esophagus for pythons and house snakes suggests that there is some anterior movement of gastric juices across the gastroesophageal junction. Given that this modest reflux of gastric fluid is localized to the most distal region of the esophagus, snakes are apparently able to prevent and protect against acid reflux in the absence of a functional LES. Copyright © 2012 Elsevier GmbH. All rights reserved.
12. Different responses of spontaneous and stimulus-related alpha activity to ambient luminance changes.
Science.gov (United States)
Benedetto, Alessandro; Lozano-Soldevilla, Diego; VanRullen, Rufin
2017-12-04
Alpha oscillations are particularly important in determining our percepts and have been implicated in fundamental brain functions. Oscillatory activity can be spontaneous or stimulus-related. Furthermore, stimulus-related responses can be phase- or non-phase-locked to the stimulus. Non-phase-locked (induced) activity can be identified as the average amplitude changes in response to a stimulation, while phase-locked activity can be measured via reverse-correlation techniques (echo function). However, the mechanisms and the functional roles of these oscillations are far from clear. Here, we investigated the effect of ambient luminance changes, known to dramatically modulate neural oscillations, on spontaneous and stimulus-related alpha. We investigated the effect of ambient luminance on EEG alpha during spontaneous human brain activity at rest (experiment 1) and during visual stimulation (experiment 2). Results show that spontaneous alpha amplitude increased by decreasing ambient luminance, while alpha frequency remained unaffected. In the second experiment, we found that under low-luminance viewing, the stimulus-related alpha amplitude was lower, and its frequency was slightly faster. These effects were evident in the phase-locked part of the alpha response (echo function), but weaker or absent in the induced (non-phase-locked) alpha responses. Finally, we explored the possible behavioural correlates of these modulations in a monocular critical flicker frequency task (experiment 3), finding that dark adaptation in the left eye decreased the temporal threshold of the right eye. Overall, we found that ambient luminance changes impact differently on spontaneous and stimulus-related alpha expression. We suggest that stimulus-related alpha activity is crucial in determining human temporal segmentation abilities. © 2017 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.
13. A NEW CLASS OF LUMINOUS TRANSIENTS AND A FIRST CENSUS OF THEIR MASSIVE STELLAR PROGENITORS
International Nuclear Information System (INIS)
Thompson, Todd A.; Prieto, Jose L.; Stanek, K. Z.; Beacom, John F.; Kochanek, Christopher S.; Kistler, Matthew D.
2009-01-01
The progenitors of SN 2008S and the 2008 luminous transient in NGC 300 were deeply dust-enshrouded massive stars, with extremely red mid-infrared (MIR) colors and relatively low bolometric luminosities (∼5 x 10 4 L sun ). The transients were optically faint compared to normal core-collapse supernovae (ccSNe), with peak absolute visual magnitudes of -13 ∼> M V ∼> -15, and their spectra exhibit narrow Balmer and [Ca II] emission lines. These events are unique among transient-progenitor pairs and hence constitute a new class. Additional members of this class may include the M85 transient, SN 1999bw, 2002bu, and others. Whether they are true supernovae or bright massive-star eruptions, we argue that their rate is of order ∼20% of the ccSN rate in star-forming galaxies. This fact is remarkable in light of the observation that a very small fraction of all massive stars in any one galaxy, at any moment, have the infrared colors of the progenitors of SN 2008S and the NGC 300 transient. We show this by extracting MIR and optical luminosity, color, and variability properties of massive stars in M33 using archival imaging. We find that the fraction of massive stars with colors consistent with the progenitors of SN 2008S and the NGC 300 transient is ∼ -4 . In fact, only ∼ 4 yr before explosion, be it death or merely eruption. We discuss the implications of this finding for the evolution and census of 'low-mass' massive stars (i.e., ∼8-12 M sun ), and we connect it with theoretical discussions of electron-capture supernovae (ecSNe) near this mass range. Other potential mechanisms, including the explosive birth of massive white dwarfs and massive star outbursts, are also discussed. A systematic census with (warm) Spitzer of galaxies in the local universe (D ∼< 10 Mpc) for analogous progenitors would significantly improve our knowledge of this channel to massive stellar explosions, and potentially to others with obscured progenitors.
14. High-protein diet modifies colonic microbiota and luminal environment but not colonocyte metabolism in the rat model: the increased luminal bulk connection
OpenAIRE
LIU, Xinxin; BLOUIN, Jean-Marc; Santacruz, Arlette; Lan, Annaig; Andriamihaja, Mireille; Wilkanowicz, Sabina; Benetti, Pierre-Henri; Tomé, Daniel; Sanz, Yolanda; Blachier, Francois; Davila-Gay, Anne-Marie
2014-01-01
High-protein diets are used for body weight reduction, but consequences on the large intestine ecosystem are poorly known. Here, rats were fed for 15 days with either a normoproteic diet (NP, 14% protein) or a hyperproteic-hypoglucidic isocaloric diet (HP, 53% protein). Cecum and colon were recovered for analysis. Short- and branched-chain fatty acids, as well as lactate, succinate, formate, and ethanol contents, were markedly increased in the colonic luminal contents of HP rats (P < 0.05 or ...
15. Cinematography of weakly - luminous transient phenomena using image converters; Cinematographie de phenomenes transitoires faiblement lumineux a l'aide d'amplificateurs de luminance
Energy Technology Data Exchange (ETDEWEB)
Stevenin, P.; Jacquot, C. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires. Services de Physique Appliquee, Service d' Ionique Generale
1966-07-01
After a review on the physical of optical informations emitted by a light source of weak intensity and short duration, the authors describe a high gain device by associating two image converters. The present specifications are given in the domain of high speed cinematography and spectrometry. (authors) [French] Apres avoir rappele la limitation d'origine physique du nombre d'informations optiques en provenance d'une source lumineuse de faible intensite et de courte duree, on decrit un appareillage a haut gain associant deux amplificateurs de luminance. On donne les performances actuelles du dispositif dans le domaine de la cinematographie et de la spectrometrie ultra-rapides. (auteurs)
16. Photocatalytic Activity and Optical Properties of Blue Persistent Phosphors under UV and Solar Irradiation
Directory of Open Access Journals (Sweden)
C. R. García
2016-01-01
Full Text Available Blue phosphorescent strontium aluminosilicate powders were prepared by combustion synthesis route and a postannealing treatments at different temperatures. X-ray diffraction analysis showed that phosphors are composed of two main hexagonal phases: SrAl2O4 and Sr3Al32O51. The morphology of the phosphors changed from micrograins (1000°C to a mixture of bars and hexagons (1200°C and finally to only hexagons (1300°C as the annealing temperature is increased. Photoluminescence spectra showed a strong blue-green phosphorescent emission centered at λem=455 nm, which is associated with 4f65d1→4f6 (8S7/2 transition of the Eu2+. The sample annealed at 1200°C presents the highest luminance value (40 Cd/m2 with CIE coordinates (0.1589, 0.1972. Also, the photocatalytic degradation of methylene blue (MB under UV light (at 365 nm was monitored. Samples annealed at 1000°C and 1300°C presented the highest percentage of degradation (32% and 38.5%, resp. after 360 min. In the case of photocatalytic activity under solar irradiation, the samples annealed at 1000°C, 1150°C, and 1200°C produced total degradation of MB after only 300 min. Hence, the results obtained with solar photocatalysis suggest that our powders could be useful for water cleaning in water treatment plants.
17. High color rendering index white organic light-emitting diode using levofloxacin as blue emitter
Science.gov (United States)
Miao, Yan-Qin; Gao, Zhi-Xiang; Zhang, Ai-Qin; Li, Yuan-Hao; Wang, Hua; Jia, Hu-Sheng; Liu, Xu-Guang; Tsuboi, Taijuf
2015-05-01
Levofloxacin (LOFX), which is well-known as an antibiotic medicament, was shown to be useful as a 452-nm blue emitter for white organic light-emitting diodes (OLEDs). In this paper, the fabricated white OLED contains a 452-nm blue emitting layer (thickness of 30 nm) with 1 wt% LOFX doped in CBP (4,4’-bis(carbazol-9-yl)biphenyl) host and a 584-nm orange emitting layer (thickness of 10 nm) with 0.8 wt% DCJTB (4-(dicyanomethylene)-2-tert-butyl-6-(1,1,7,7-tetramethyljulolidin-4-yl-vinyl)-4H-pyran) doped in CBP, which are separated by a 20-nm-thick buffer layer of TPBi (2,2’,2”-(benzene-1,3,5-triyl)-tri(1-phenyl-1H-benzimidazole). A high color rendering index (CRI) of 84.5 and CIE chromaticity coordinates of (0.33, 0.32), which is close to ideal white emission CIE (0.333, 0.333), are obtained at a bias voltage of 14 V. Taking into account that LOFX is less expensive and the synthesis and purification technologies of LOFX are mature, these results indicate that blue fluorescence emitting LOFX is useful for applications to white OLEDs although the maximum current efficiency and luminance are not high. The present paper is expected to become a milestone to using medical drug materials for OLEDs. Project supported by the Program for New Century Excellent Talents in University of Ministry of Education of China (Grant No. NCET-13-0927), the International Science & Technology Cooperation Program of China (Grant No. 2012DFR50460), the National Natural Science Foundation of China (Grant Nos. 21101111 and 61274056), and the Shanxi Provincial Key Innovative Research Team in Science and Technology, China (Grant No. 2012041011).
18. "Blue-Collar Blues" uurib töösuhteid uutes oludes / Janar Ala
Index Scriptorium Estoniae
Ala, Janar, 1979-
2009-01-01
Tööproblemaatikat käsitlev näitus "Blue-Collar Blues" Tallinna Kunstihoones ja Tallinna Kunstihoone galeriis 31. jaanuarini 2010, kuraator Anders Härm. Lähemalt belgia-mehhiko kunstniku Francis Alys'e videost, austria kunstniku Oliver Ressleri ning venetsueela-saksa politoloogi Dario Azzelini videost "Viis tehast. Tööliste kontroll Venezuelas"
19. Candidate luminal B breast cancer genes identified by genome, gene expression and DNA methylation profiling.
Directory of Open Access Journals (Sweden)
Stéphanie Cornen
Full Text Available Breast cancers (BCs of the luminal B subtype are estrogen receptor-positive (ER+, highly proliferative, resistant to standard therapies and have a poor prognosis. To better understand this subtype we compared DNA copy number aberrations (CNAs, DNA promoter methylation, gene expression profiles, and somatic mutations in nine selected genes, in 32 luminal B tumors with those observed in 156 BCs of the other molecular subtypes. Frequent CNAs included 8p11-p12 and 11q13.1-q13.2 amplifications, 7q11.22-q34, 8q21.12-q24.23, 12p12.3-p13.1, 12q13.11-q24.11, 14q21.1-q23.1, 17q11.1-q25.1, 20q11.23-q13.33 gains and 6q14.1-q24.2, 9p21.3-p24,3, 9q21.2, 18p11.31-p11.32 losses. A total of 237 and 101 luminal B-specific candidate oncogenes and tumor suppressor genes (TSGs presented a deregulated expression in relation with their CNAs, including 11 genes previously reported associated with endocrine resistance. Interestingly, 88% of the potential TSGs are located within chromosome arm 6q, and seven candidate oncogenes are potential therapeutic targets. A total of 100 candidate oncogenes were validated in a public series of 5,765 BCs and the overexpression of 67 of these was associated with poor survival in luminal tumors. Twenty-four genes presented a deregulated expression in relation with a high DNA methylation level. FOXO3, PIK3CA and TP53 were the most frequent mutated genes among the nine tested. In a meta-analysis of next-generation sequencing data in 875 BCs, KCNB2 mutations were associated with luminal B cases while candidate TSGs MDN1 (6q15 and UTRN (6q24, were mutated in this subtype. In conclusion, we have reported luminal B candidate genes that may play a role in the development and/or hormone resistance of this aggressive subtype.
20. Assessment of atherosclerotic luminal narrowing of coronary arteries based on morphometrically generated visual guides.
Science.gov (United States)
Barth, Rolf F; Kellough, David A; Allenby, Patricia; Blower, Luke E; Hammond, Scott H; Allenby, Greg M; Buja, L Maximilian
Determination of the degree of stenosis of atherosclerotic coronary arteries is an important part of postmortem examination of the heart, but, unfortunately, estimation of the degree of luminal narrowing can be imprecise and tends to be approximations. Visual guides can be useful to assess this, but earlier attempts to develop such guides did not employ digital technology. Using this approach, we have developed two computer-generated morphometric guides to estimate the degree of luminal narrowing of atherosclerotic coronary arteries. The first is based on symmetric or eccentric circular or crescentic narrowing of the vessel lumen and the second on either slit-like or irregularly shaped narrowing of the vessel lumens. Using the Aperio ScanScope XT at a magnification of 20× we created digital whole-slide images of 20 representative microscopic cross sections of the left anterior descending (LAD) coronary artery, stained with either hematoxylin and eosin (H&E) or Movat's pentachrome stain. These cross sections illustrated a variety of luminal profiles and degrees of stenosis. Three representative types of images were selected and a visual guide was constructed with Adobe Photoshop CS5. Using the "Scale" and "Measurement" tools, we created a series of representations of stenosis with luminal cross sections depicting 20%, 40%, 60%, 70%, 80%, and 90% occlusion of the LAD branch. Four pathologists independently reviewed and scored the degree of atherosclerotic luminal narrowing based on our visual guides. In addition, digital technology was employed to determine the degree of narrowing by measuring the cross-sectional area of the 20 microscopic sections of the vessels, first assuming no narrowing and then comparing this to the percent of narrowing determined by precise measurement. Two of the observers were very experienced general autopsy pathologists, one was a first-year pathology resident on his first rotation on the autopsy service, and the fourth observer was a
1. Hard X-ray emission of the luminous infrared galaxy NGC 6240 as observed by NuSTAR
Science.gov (United States)
Puccetti, S.; Comastri, A.; Bauer, F. E.; Brandt, W. N.; Fiore, F.; Harrison, F. A.; Luo, B.; Stern, D.; Urry, C. M.; Alexander, D. M.; Annuar, A.; Arévalo, P.; Baloković, M.; Boggs, S. E.; Brightman, M.; Christensen, F. E.; Craig, W. W.; Gandhi, P.; Hailey, C. J.; Koss, M. J.; La Massa, S.; Marinucci, A.; Ricci, C.; Walton, D. J.; Zappacosta, L.; Zhang, W.
2016-01-01
We present a broadband (~0.3-70 keV) spectral and temporal analysis of NuSTAR observations of the luminous infrared galaxy NGC 6240 combined with archival Chandra, XMM-Newton, and BeppoSAX data. NGC 6240 is a galaxy in a relatively early merger state with two distinct nuclei separated by ~1.̋5. Previous Chandra observations resolved the two nuclei and showed that they are both active and obscured by Compton-thick material. Although they cannot be resolved by NuSTAR, we were able to clearly detect, for the first time, both the primary and the reflection continuum components thanks to the unprecedented quality of the NuSTAR data at energies >10 keV. The NuSTAR hard X-ray spectrum is dominated by the primary continuum piercing through an absorbing column density which is mildly optically thick to Compton scattering (τ ≃ 1.2, NH ~ 1.5 × 1024 cm-2). We detect moderately hard X-ray (>10 keV) flux variability up to 20% on short (15-20 ks) timescales. The amplitude of the variability is largest at ~30 keV and is likely to originate from the primary continuum of the southern nucleus. Nevertheless, the mean hard X-ray flux on longer timescales (years) is relatively constant. Moreover, the two nuclei remain Compton-thick, although we find evidence of variability in the material along the line of sight with column densities NH ≤ 2 × 1023 cm-2 over long (~3-15 yr) timescales. The observed X-ray emission in the NuSTAR energy range is fully consistent with the sum of the best-fit models of the spatially resolved Chandra spectra of the two nuclei.
2. The Structure of the Blue Whirl
Science.gov (United States)
Hariharan, Sriram Bharath; Hu, Yu; Xiao, Huahua; Gollner, Michael; Oran, Elaine
2017-11-01
Recent experiments have led to the discovery of the blue whirl, a small, stable regime of the fire whirl that burns typically sooty liquid hydrocarbons without producing soot. The physical structure consists of three regions - the blue cone, the vortex rim and the purple haze. The physical nature of the flame was further investigated through digital imaging techniques, which suggest that the transition (from the fire whirl to the blue whirl) and shape of the flame may be influenced by vortex breakdown. The flame was found to develop over a variety of surfaces, which indicates that the formation of the blue whirl is strongly influenced by the flow structure over the incoming boundary layer. The thermal structure was investigated using micro-thermocouples, thin-filament pyrometry and OH* spectroscopy. These revealed a peak temperature around 2000 K, and that most of the combustion occurs in the relatively small, visibly bright vortex rim. The results of these investigations provide a platform to develop a theory on the structure of the blue whirl, a deeper understanding of which may affirm potential for applications in the energy industry. This work was supported by an NSF EAGER award and Minta Martin Endowment Funds in the Department of Aerospace Engineering at the University of Maryland.
3. Dyes adsorption blue vegetable and blue watercolor by natural zeolites modified with surfactants
International Nuclear Information System (INIS)
Jardon S, C. C.; Olguin G, M. T.; Diaz N, M. C.
2009-01-01
In this work was carried out the dyes removal blue vegetable and blue watercolor of aqueous solutions, to 20 C, at different times and using a zeolite mineral of Parral (Chihuahua, Mexico) modified with hexadecyl trimethyl ammonium bromide or dodecyl trimethyl ammonium bromide. The zeolite was characterized before and after of its adaptation with NaCl and later with HDTMABr and DTMABr. For the materials characterization were used the scanning electron microscopy of high vacuum; elementary microanalysis by X-ray spectroscopy of dispersed energy and X-ray diffraction techniques. It was found that the surfactant type absorbed in the zeolite material influences on the adsorption process of the blue dye. Likewise, the chemical structure between the vegetable blue dye and the blue watercolor, determines the efficiency of the color removal of the water, by the zeolites modified with the surfactants. (Author)
4. Relation between acid back-diffusion and luminal surface hydrophobicity in canine gastric mucosa: Effects of salicylate and prostaglandin
International Nuclear Information System (INIS)
Goddard, P.J.
1989-01-01
The stomach is thought to be protected from luminal acid by a gastric mucosal barrier that restricts the diffusion of acid into tissue. This study tested the hypothesis that the hydrophobic luminal surface of canine gastric mucosa incubated in Ussing chambers, impedes the back-diffusion of luminal acid into the tissue. Isolated sheets of mucosa were treated with cimetidine to inhibit spontaneous acid secretion, and incubated under conditions that prevented significant secretion of luminal bicarbonate. By measuring acid loss from the luminal compartment using the pH-stat technique, acid back-diffusion was continuously monitored; potential difference (PD) was measured as an index of tissue viability. Tissue luminal surface hydrophobicity was estimated by contact angle analysis at the end of each experiment. Addition of 16,16-dimethyl prostaglandin E 2 to the nutrient compartment enhanced luminal surface hydrophobicity, but did not reduce acid back-diffusion in tissues that maintained a constant PD. 10 mM salicylate at pH 4.00 in the luminal compartment reduced surface hydrophobicity, but this decrease did not occur if 1 ug/ml prostaglandin was present in the nutrient solution. Despite possessing relatively hydrophilic and relatively hydrophobic surface properties, respectively, acid back-diffusion in the absence of salicylate was not significantly different between these two groups. Neither group maintained a PD after incubation with salicylate. Lastly, radiolabeled salicylate was used to calculate the free (non-salicylate associated) acid loss in tissues incubated with salicylate and/or prostaglandin. No significant correlation was found between free acid back-diffusion and luminal surface hydrophobicity. These data do not support the hypothesis that acid back-diffusion in impeded by the hydrophobic surface presented by isolated canine gastric mucosa
5. Immunohistochemical localisation of keratin and luminal epithelial antigen in myoepithelial and luminal epithelial cells of human mammary and salivary gland tumours.
Science.gov (United States)
Nathrath, W B; Wilson, P D; Trejdosiewicz, L K
1982-01-01
Rabbit antisera to human 40-63 000 MW epidermal keratin, one batch with restricted distribution of reactivity from an initial (aK1) and one with "broad spectrum" distribution of reactivity from a late bleeding (aK), and to "luminal epithelial antigen" (aLEA) were applied to formalin fixed paraffin embedded sections of human normal and neoplastic mammary and salivary glands using an indirect immunoperoxidase method. aK1 reacted with myoepithelial cells, aLEA with luminal epithelial cells and aK with both cell types in normal mammary and salivary gland. In breast carcinomas the majority of intraluminal and infiltrating carcinoma cells reacted with aLEA but not with aK1 which reacted only with surrounding myoepithelial cells. aK reacted with both myoepithelial cells and with intraluminal and infiltrating tumour cells. In the salivary gland adenomas the majority of cells reacted with aK, and those cells arranged in a tubular fashion reacted with aLEA.
6. Origin of colour stability in blue/orange/blue stacked phosphorescent white organic light-emitting diodes
International Nuclear Information System (INIS)
Kim, Sung Hyun; Jang, Jyongsik; Yook, Kyoung Soo; Lee, Jun Yeob
2009-01-01
The origin of colour stability in phosphorescent white organic light-emitting diodes (PHWOLEDs) with a blue/orange/blue stacked emitting structure was studied by monitoring the change in a recombination zone. A balanced recombination zone shift between the blue and the orange light-emitting layers was found to be responsible for the colour stability in the blue/orange/blue stacked PHWOLEDs.
7. The most luminous heavily obscured quasars have a high merger fraction: morphological study of wise -selected hot dust-obscured galaxies
Energy Technology Data Exchange (ETDEWEB)
Fan, Lulu; Gao, Ying; Zhang, Dandan; Jiang, Xiaoming; Wu, Qiaoqian; Yang, Jun; Li, Zhao [Shandong Provincial Key Lab of Optical Astronomy and Solar-Terrestrial Environment, Institute of Space Science, Shandong University, Weihai 264209 (China); Han, Yunkun [Yunnan Observatories, Chinese Academy of Sciences, Kunming 650011 (China); Fang, Guanwen, E-mail: llfan@sdu.edu.cn, E-mail: hanyk@ynao.ac.cn [Institute for Astronomy and History of Science and Technology, Dali University, Dali 671003 (China)
2016-05-10
Previous studies have shown that Wide-field Infrared Survey Explorer -selected hyperluminous, hot dust-obscured galaxies (Hot DOGs) are powered by highly dust-obscured, possibly Compton-thick active galactic nuclei (AGNs). High obscuration provides us a good chance to study the host morphology of the most luminous AGNs directly. We analyze the host morphology of 18 Hot DOGs at z ∼ 3 using Hubble Space Telescope /WFC3 imaging. We find that Hot DOGs have a high merger fraction (62 ± 14%). By fitting the surface brightness profiles, we find that the distribution of Sérsic indices in our Hot DOG sample peaks around 2, which suggests that most Hot DOGs have transforming morphologies. We also derive the AGN bolometric luminosity (∼10{sup 14} L {sub ⊙}) of our Hot DOG sample by using IR spectral energy distributions decomposition. The derived merger fraction and AGN bolometric luminosity relation is well consistent with the variability-based model prediction. Both the high merger fraction in an IR-luminous AGN sample and relatively low merger fraction in a UV/optical-selected, unobscured AGN sample can be expected in the merger-driven evolutionary model. Finally, we conclude that Hot DOGs are merger-driven and may represent a transit phase during the evolution of massive galaxies, transforming from the dusty starburst-dominated phase to the unobscured QSO phase.
8. Colour and luminance contrasts predict the human detection of natural stimuli in complex visual environments.
Science.gov (United States)
White, Thomas E; Rojas, Bibiana; Mappes, Johanna; Rautiala, Petri; Kemp, Darrell J
2017-09-01
Much of what we know about human colour perception has come from psychophysical studies conducted in tightly-controlled laboratory settings. An enduring challenge, however, lies in extrapolating this knowledge to the noisy conditions that characterize our actual visual experience. Here we combine statistical models of visual perception with empirical data to explore how chromatic (hue/saturation) and achromatic (luminant) information underpins the detection and classification of stimuli in a complex forest environment. The data best support a simple linear model of stimulus detection as an additive function of both luminance and saturation contrast. The strength of each predictor is modest yet consistent across gross variation in viewing conditions, which accords with expectation based upon general primate psychophysics. Our findings implicate simple visual cues in the guidance of perception amidst natural noise, and highlight the potential for informing human vision via a fusion between psychophysical modelling and real-world behaviour. © 2017 The Author(s).
9. Automatic Supervision of Temperature, Humidity, and Luminance with an Assistant Personal Robot
Directory of Open Access Journals (Sweden)
Jordi Palacín
2017-01-01
Full Text Available Smart environments and Ambient Intelligence (AmI technologies are defining the future society where energy optimization and intelligent management are essential for a sustainable advance. Mobile robotics is also making an important contribution to this advance with the integration of sensors and intelligent processing algorithms. This paper presents the application of an Assistant Personal Robot (APR as an autonomous agent for temperature, humidity, and luminance supervision in human-frequented areas. The robot multiagent capabilities allow gathering sensor information while exploring or performing specific tasks and then verifying human comfortability levels. The proposed methodology creates information maps with the distribution of temperature, humidity, and luminance and interprets such information in terms of comfort and warns about corrective actuations if required.
10. The Dichotomous Cosmology with a Static Material World and Expanding Luminous World
Directory of Open Access Journals (Sweden)
Heymann Y.
2014-07-01
Full Text Available The dichotomous cosmology is an alternative to the expanding Universe theory, and consists of a static matter Universe, where cosmological redshifts are explained by a tired-light model with an expanding luminous world. In this model the Hubble constant is also the photon energy decay rate, and the luminous world i s expanding at a constant rate as in de Sitter cosmology for an empty Universe. The present model explains both the luminosity distance versus redshift relationship of supernovae Ia, and ageing of spectra observed with the stretching of supernovae light curves. Furthermore, it is consistent with a radiation energy density factor (1 + z 4 inferred from the Cosmic Microwave Background Radiation.
11. Hot spots effect on infrared spectral luminance emitted by carbon under plasma particles impact
International Nuclear Information System (INIS)
Delchambre, E.; Reichle, R.; Mitteau, R.; Missirlian, M.; Gobin, R.
2004-01-01
During the last Tore Supra campaigns, an anomalous deformation in the near infrared spectrum of radiation has been observed on neutralizer underneath the Toroidal Pumped Limiter (TPL) on which we observed the growth of carbon layer. The consequence is the difficulty to asses the surface temperature of the components and the power loaded. Laboratory experiment has been performed, using an Electron Cyclotron Resonance (ECR) ions source, to reproduce, characterize and explain this phenomenon. The luminance emitted by Carbon Fibre Composite (CFC) and pyrolytic graphite, have been observed under 95 keV of H+ bombardments. The amplitude of the deformation was found to depend on the type of material used and the power density of the incident power loaded. This paper presents the possible hot spots explanation. The experimental luminance deformation is reproduced and these results are validated using a thermal model of dust in radiate equilibrium. (authors)
12. Luciferase genes cloned from the unculturable luminous bacteroid symbiont of the Caribbean flashlight fish, Kryptophanaron alfredi.
Science.gov (United States)
Haygood, M G; Cohn, D H
1986-01-01
Light organs of anomalopid (flashlight) fish contain luminous bacteroids that have never been cultured and, consequently, have been difficult to study. We have characterized the luciferase (lux) region of DNA extracted from light organs of the Caribbean flashlight fish Kryptophanaron alfredi by hybridization of cloned Vibrio harveyi lux genes to restriction-endonuclease-digested, light organ DNA. Comparison of the hybridization pattern of light organ DNA with that of DNA of a putative symbiotic isolate provides a method for identifying the authentic luminous symbiont regardless of its luminescence, and was used to reject one such isolate. Light organ DNA was further used to construct a cosmid clone bank and the luciferase genes were isolated. Unlike other bacterial luciferase genes, the genes were not expressed in Escherichia coli. When placed under the control of the E. coli trp promoter, the genes were transcribed but no luciferase was detected, suggesting a posttranscriptional block to expression.
13. Radioisotope treatment for benign strictures of non-vascular luminal organs
International Nuclear Information System (INIS)
Shin, Ji Hoon
2006-01-01
14. Observations of Intermediate-mass Black Holes and Ultra-Luminous X-ray sources
Science.gov (United States)
Colbert, E. J. M.
2003-12-01
I will review various observations that suggest that intermediate-mass black holes (IMBHs) with masses ˜102-104 M⊙ exist in our Universe. I will also discuss some of the limitations of these observations. HST Observations of excess dark mass in globular cluster cores suggest IMBHs may be responsible, and some mass estimates from lensing experiments are nearly in the IMBH range. The intriguing Ultra-Luminous X-ray sources (ULXs, or IXOs) are off-nuclear X-ray point sources with X-ray luminosities LX ≳ 1039 erg s-1. ULXs are typically rare (1 in every 5 galaxies), and the nature of their ultra-luminous emission is currently debated. I will discuss the evidence for IMBHs in some ULXs, and briefly outline some phenomenology. Finally, I will discuss future observations that can be made to search for IMBHs.
Science.gov (United States)
Hasse, C D; Zoutendam, G L; Gombas, O F
1978-05-01
Blue nevus of the oral mucosa is a distinctly uncommon clincial entity. Careful review of the literature yielded thirty-one previously reported cases. The present article reports the occurrence of a blue nevus of the hard palate in a 58-year-old man. It is of interest since it is the smallest (1 by 1 mm.) intraoral blue nevus to be reported. A clinicopathologic study of the previous thirty-one cases and of our case suggests that this lesion has no age or sex predilection. The most common site of occurrence was the hard palate. There appears to be no tendency toward recurrence. A brief review of the historical background, clinical features, theories of possible origin, and differential diagnosis is presented. Excisional biopsy of localized areas of oral pibmentation, together with histopathologic study, is indicated to rule out melanoma.
16. Lowering the driving voltage and improving the luminance of blue fluorescent organic light-emitting devices by thermal annealing a hole injection layer of pentacene
Science.gov (United States)
Gao, Jian; Yu, Qian-Qian; Zhang, Juan; Liu, Yang; Jia, Ruo-Fei; Han, Jun; Wu, Xiao-Ming; Hua, Yu-Lin; Yin, Shou-Gen
2017-08-01
Not Available Project supported by the National Natural Science Foundation of China (Grant No. 60906022), the Natural Science Foundation of Tianjin, China (Grant No. 10JCYBJC01100), the Key Science and Technology Support Program of Tianjin, China (Grant No. 14ZCZDGX00006), and the National High Technology Research and Development Program of China (Grant No. 2013AA014201).
17. Luminal flow amplifies stent-based drug deposition in arterial bifurcations.
Directory of Open Access Journals (Sweden)
Vijaya B Kolachalama
2009-12-01
Full Text Available Treatment of arterial bifurcation lesions using drug-eluting stents (DES is now common clinical practice and yet the mechanisms governing drug distribution in these complex morphologies are incompletely understood. It is still not evident how to efficiently determine the efficacy of local drug delivery and quantify zones of excessive drug that are harbingers of vascular toxicity and thrombosis, and areas of depletion that are associated with tissue overgrowth and luminal re-narrowing.We constructed two-phase computational models of stent-deployed arterial bifurcations simulating blood flow and drug transport to investigate the factors modulating drug distribution when the main-branch (MB was treated using a DES. Simulations predicted extensive flow-mediated drug delivery in bifurcated vascular beds where the drug distribution patterns are heterogeneous and sensitive to relative stent position and luminal flow. A single DES in the MB coupled with large retrograde luminal flow on the lateral wall of the side-branch (SB can provide drug deposition on the SB lumen-wall interface, except when the MB stent is downstream of the SB flow divider. In an even more dramatic fashion, the presence of the SB affects drug distribution in the stented MB. Here fluid mechanic effects play an even greater role than in the SB especially when the DES is across and downstream to the flow divider and in a manner dependent upon the Reynolds number.The flow effects on drug deposition and subsequent uptake from endovascular DES are amplified in bifurcation lesions. When only one branch is stented, a complex interplay occurs - drug deposition in the stented MB is altered by the flow divider imposed by the SB and in the SB by the presence of a DES in the MB. The use of DES in arterial bifurcations requires a complex calculus that balances vascular and stent geometry as well as luminal flow.
18. Intratumoral estrogen production and actions in luminal A type invasive lobular and ductal carcinomas.
Science.gov (United States)
Takagi, Mayu; Miki, Yasuhiro; Miyashita, Minoru; Hata, Shuko; Yoda, Tomomi; Hirakawa, Hisashi; Sagara, Yasuaki; Rai, Yoshiaki; Ohi, Yasuyo; Tamaki, Kentaro; Ishida, Takanori; Suzuki, Takashi; Ouchi, Noriaki; Sasano, Hironobu
2016-02-01
The great majority of invasive lobular carcinoma (ILC) is estrogen-dependent luminal A type carcinoma but the details of estrogen actions and its intratumoral metabolism have not been well studied compared to invasive ductal carcinoma (IDC). We first immunolocalized estrogen-related enzymes including estrogen sulfotransferase (EST), estrogen sulfatase (STS), 17β-hydroxysteroid dehydrogenase (HSD) 1/2, and aromatase. We then evaluated the tissue concentrations of estrogens in ILC and IDC and subsequently estrogen-responsive gene profiles in these tumors in order to explore the possible differences and/or similarity of intratumoral estrogen environment of these two breast cancer subtypes. The status of STS and 17βHSD1 was significantly lower in ILCs than IDCs (p = 0.022 and p < 0.0001), but that of EST and 17βHSD2 vice versa (p < 0.0001 and p = 0.0106). In ILCs, tissue concentrations of estrone and estradiol were lower than those in IDCs (p = 0.0709 and 0.069). In addition, the great majority of estrogen response genes tended to be lower in ILCs. Among those genes above, FOXP1 was significantly higher in ILCs than in IDCs (p = 0.002). FOXP1 expression was reported to be significantly higher in relapse-free IDC patients treated with tamoxifen. Therefore, tamoxifen may be considered an option of endocrine therapy for luminal A type ILC patients. This is the first study to demonstrate the detailed and comprehensive status of intratumoral production and metabolism of estrogens and the status of estrogen response genes in luminal A-like ILC with comparison to those in luminal A-like IDCs.
19. The uncultured luminous symbiont of Anomalops katoptron (Beryciformes: Anomalopidae) represents a new bacterial genus.
Science.gov (United States)
Hendry, Tory A; Dunlap, Paul V
2011-12-01
Flashlight fishes (Beryciformes: Anomalopidae) harbor luminous symbiotic bacteria in subocular light organs and use the bacterial light for predator avoidance, feeding, and communication. Despite many attempts anomalopid symbionts have not been brought into laboratory culture, which has restricted progress in understanding their phylogenetic relationships with other luminous bacteria, identification of the genes of their luminescence system, as well as the nature of their symbiotic interactions with their fish hosts. To begin addressing these issues, we used culture-independent analysis of the bacteria symbiotic with the anomalopid fish, Anomalops katoptron, to characterize the phylogeny of the bacteria and to identify the genes of their luminescence system including those involved in the regulation of luminescence. Analysis of the 16S rRNA, atpA, gapA, gyrB, pyrH, recA, rpoA, and topA genes resolved the A. katoptron symbionts as a clade nested within and deeply divergent from other members of Vibrionaceae. The bacterial luminescence (lux) genes were identified as a contiguous set (luxCDABEG), as found for the lux operons of other luminous bacteria. Phylogenetic analysis based on the lux genes confirmed the housekeeping gene phylogenetic placement. Furthermore, genes flanking the lux operon in the A. katoptron symbionts differed from those flanking lux operons of other genera of luminous bacteria. We therefore propose the candidate name Candidatus Photodesmus (Greek: photo = light, desmus = servant) katoptron for the species of bacteria symbiotic with A. katoptron. Results of a preliminary genomic analysis for genes regulating luminescence in other bacteria identified only a Vibrio harveyi-type luxR gene. These results suggest that expression of the luminescence system might be continuous in P. katoptron. Copyright © 2011 Elsevier Inc. All rights reserved.
20. Variability Bugs:
DEFF Research Database (Denmark)
Melo, Jean
. Although many researchers suggest that preprocessor-based variability amplifies maintenance problems, there is little to no hard evidence on how actually variability affects programs and programmers. Specifically, how does variability affect programmers during maintenance tasks (bug finding in particular......)? How much harder is it to debug a program as variability increases? How do developers debug programs with variability? In what ways does variability affect bugs? In this Ph.D. thesis, I set off to address such issues through different perspectives using empirical research (based on controlled...... experiments) in order to understand quantitatively and qualitatively the impact of variability on programmers at bug finding and on buggy programs. From the program (and bug) perspective, the results show that variability is ubiquitous. There appears to be no specific nature of variability bugs that could...
1. Winds in cataclysmic variable stars
International Nuclear Information System (INIS)
Cordova, F.A.; Ladd, E.F.; Mason, K.O.
1984-01-01
Ultraviolet spectrophotometry of two dwarf novae, CN Ori and RX And, at various phases of their outburst cycles confirms that the far uv flux increases dramatically about 1-2 days after the optical outburst begins. At this time the uv spectral line profiles indicate the presence of a high velocity wind. The detectability of the wind depends more on the steepness of the spectrum, and thus on the flux in the extreme ultraviolet, than on the absolute value of the far uv luminosity. The uv continuum during outburst consists of (at least) two components, the most luminous of which is located behind the wind and is completely absorbed by the wind at the line frequencies. Several pieces of evidence suggest that the uv emission lines that are observed in many cataclysmic variables during quiescence have a different location in the binary than the wind, and are affected very little by the outburst
2. Hybrid metal grid-polymer-carbon nanotube electrodes for high luminance organic light emitting diodes
International Nuclear Information System (INIS)
Sam, F Laurent M; Dabera, G Dinesha M R; Lai, Khue T; Mills, Christopher A; Rozanski, Lynn J; Silva, S Ravi P
2014-01-01
Organic light emitting diodes (OLEDs) incorporating grid transparent conducting electrodes (TCEs) with wide grid line spacing suffer from an inability to transfer charge carriers across the gaps in the grids to promote light emission in these areas. High luminance OLEDs fabricated using a hybrid TCE composed of poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS PH1000) or regioregular poly(3-hexylthiophene)-wrapped semiconducting single-walled carbon nanotubes (rrP3HT-SWCNT) in combination with a nanometre thin gold grid are reported here. OLEDs fabricated using the hybrid gold grid/PH1000 TCE have a luminance of 18 000 cd m −2 at 9 V; the same as the reference indium tin oxide (ITO) OLED. The gold grid/rrP3HT-SWCNT OLEDs have a lower luminance of 8260 cd m −2 at 9 V, which is likely due to a rougher rrP3HT-SWCNT surface. These results demonstrate that the hybrid gold grid/PH1000 TCE is a promising replacement for ITO in future plastic electronics applications including OLEDs and organic photovoltaics. For applications where surface roughness is not critical, e.g. electrochromic devices or discharge of static electricity, the gold grid/rrP3HT-SWCNT hybrid TCE can be employed. (paper)
3. Radiation properties of two types of luminous textile devices containing plastic optical fibers
Science.gov (United States)
Selm, Bärbel; Rothmaier, Markus
2007-05-01
Luminous textiles have the potential to satisfy a need for thin and flexible light diffusers for treatment of intraoral cancerous tissue. Plastic optical fibers (POF) with diameters of 250 microns and smaller are used to make the textiles luminous. Usually light is supplied to the optical fiber at both ends. On the textile surface light emission occurs in a woven structure via damaged straight POFs, whereas the embroidered structure radiates the light out of macroscopically bent POFs. We compared the optical properties of these two types of textile diffusers using red light laser for the embroidery and light emitting diode (LED) for the woven structure as light sources, and found efficiencies for the luminous areas of the two samples of 19 % (woven) and 32 % (embroidery), respectively. It was shown that the efficiency can be greatly improved using an aluminium backing. Additional scattering layers lower the fluence rate by around 30 %. To analyse the homogeneity we took a photo of the illuminated surface using a 3CCD camera and found, for both textiles, a slightly skewed distribution of the dark and bright pixels. The interquartile range of brightness distribution of the embroidery is more than double as the woven structure.
4. Effect of low-dose ionizing radiation on luminous marine bacteria: radiation hormesis and toxicity
International Nuclear Information System (INIS)
Kudryasheva, N.S.; Rozhko, T.V.
2015-01-01
5. Clustering Batik Images using Fuzzy C-Means Algorithm Based on Log-Average Luminance
Directory of Open Access Journals (Sweden)
2012-06-01
Full Text Available Batik is a fabric or clothes that are made with a special staining technique called wax-resist dyeing and is one of the cultural heritage which has high artistic value. In order to improve the efficiency and give better semantic to the image, some researchers apply clustering algorithm for managing images before they can be retrieved. Image clustering is a process of grouping images based on their similarity. In this paper we attempt to provide an alternative method of grouping batik image using fuzzy c-means (FCM algorithm based on log-average luminance of the batik. FCM clustering algorithm is an algorithm that works using fuzzy models that allow all data from all cluster members are formed with different degrees of membership between 0 and 1. Log-average luminance (LAL is the average value of the lighting in an image. We can compare different image lighting from one image to another using LAL. From the experiments that have been made, it can be concluded that fuzzy c-means algorithm can be used for batik image clustering based on log-average luminance of each image possessed.
6. An analytical model for backscattered luminance in fog: comparisons with Monte Carlo computations and experimental results
International Nuclear Information System (INIS)
Taillade, Frédéric; Dumont, Eric; Belin, Etienne
2008-01-01
We propose an analytical model for backscattered luminance in fog and derive an expression for the visibility signal-to-noise ratio as a function of meteorological visibility distance. The model uses single scattering processes. It is based on the Mie theory and the geometry of the optical device (emitter and receiver). In particular, we present an overlap function and take the phase function of fog into account. The results of the backscattered luminance obtained with our analytical model are compared to simulations made using the Monte Carlo method based on multiple scattering processes. An excellent agreement is found in that the discrepancy between the results is smaller than the Monte Carlo standard uncertainties. If we take no account of the geometry of the optical device, the results of the model-estimated backscattered luminance differ from the simulations by a factor 20. We also conclude that the signal-to-noise ratio computed with the Monte Carlo method and our analytical model is in good agreement with experimental results since the mean difference between the calculations and experimental measurements is smaller than the experimental uncertainty
7. A CANDIDATE FOR THE MOST LUMINOUS OB ASSOCIATION IN THE GALAXY
International Nuclear Information System (INIS)
Rahman, Mubdi; Matzner, Christopher; Moon, Dae-Sik
2011-01-01
The Milky Way harbors giant H II regions, which may be powered by star complexes more luminous than any known Galactic OB association. Being across the disk of the Galaxy, however, these brightest associations are severely extinguished and confused. We present a search for one such association toward the most luminous H II region in the recent catalog by Murray and Rahman, which, at ∼9.7 kpc, has a recombination rate of ∼7 x 10 51 s -1 . Prior searches have identified only small-scale clustering around the rim of this shell-like region, but the primary association has not previously been identified. We apply a near-infrared color selection and find an overdensity of point sources toward its southern central part. The colors and magnitudes of these excess sources are consistent with O- and early B-type stars at extinctions 0.96 K < 1.2, and they are sufficiently numerous (406 ± 102 after subtraction of field sources) to ionize the surrounding H II region, making this a candidate for the most luminous OB association in the Galaxy. We reject an alternate theory, in which the apparent excess is caused by localized extinction, as inconsistent with source demographics.
8. Luminal DMSO: Effects on Detrusor and Urothelial/Lamina Propria Function
Directory of Open Access Journals (Sweden)
Katrina J. Smith
2014-01-01
Full Text Available DMSO is used as a treatment for interstitial cystitis and this study examined the effects of luminal DMSO treatment on bladder function and histology. Porcine bladder was incubated without (controls or with DMSO (50% applied to the luminal surface and the release of ATP, acetylcholine, and LDH assessed during incubation and in tissues strips after DMSO incubation. Luminally applied DMSO caused ATP, Ach, and LDH release from the urothelial surface during treatment, with loss of urothelial layers also evident histologically. In strips of urothelium/lamina propria from DMSO pretreated bladders the release of both ATP and Ach was depressed, while contractile responses to carbachol were enhanced. Detrusor muscle contractile responses to carbachol were not affected by DMSO pretreatment, but neurogenic responses to electrical field stimulation were enhanced. The presence of an intact urothelium/lamina propria inhibited detrusor contraction to carbachol by 53% and this inhibition was significantly reduced in DMSO pretreated tissues. Detection of LDH in the treatment medium suggests that DMSO permeabilised urothelial membranes causing leakage of cytosolic contents including ATP and Ach rather than enhancing release of these mediators. The increase in contractile response and high levels of ATP are consistent with initial flare up in IC/PBS symptoms after DMSO treatment.
9. Epimorphin mediates mammary luminal morphogenesis through control of C/EBPbeta
International Nuclear Information System (INIS)
Hirai, Yohei; Radisky, Derek; Boudreau, Rosanne; Simian, Marina; Stevens, Mary E.; Oka, Yumiko; Takebe, Kyoko; Niwa, Shinichiro; Bissell, Mina J.
2002-01-01
We have previously shown that epimorphin, a protein expressed on the surface of myoepithelial and fibroblast cells of the mammary gland, acts as a multifunctional morphogen of mammary epithelial cells. Here, we present the molecular mechanism by which epimorphin mediates luminal morphogenesis. Treatment of cells with epimorphin to induce lumen formation greatly increases the overall expression of transcription factor CCAAT/enhancer binding protein beta (C/EBPbeta) and alters the relative expression of its two principal isoforms, LIP and LAP. These alterations were shown to be essential for the morphogenetic activities, as constitutive expression of LIP was sufficient to produce lumen formation, while constitutive expression of LAP blocked epimorphin-mediated luminal morphogenesis. Furthermore, in a transgenic mouse model in which epimorphin expression was expressed in an apolar fashion on the surface of mammary epithelial cells, we found increased expression of C/EBPbeta, increased relative expression of LIP to LAP, and enlarged ductal lumina. Together, our studies demonstrate a role for epimorphin in luminal morphogenesis through control of C/EBPbeta expression
10. Id-1 is not expressed in the luminal epithelial cells of mammary glands
International Nuclear Information System (INIS)
Uehara, Norihisa; Chou, Yu-Chien; Galvez, Jose J; Candia, Paola de; Cardiff, Robert D; Benezra, Robert; Shyamala, Gopalan
2003-01-01
The family of inhibitor of differentiation/DNA binding (Id) proteins is known to regulate development in several tissues. One member of this gene family, Id-1, has been implicated in mammary development and carcinogenesis. Mammary glands contain various cell types, among which the luminal epithelial cells are primarily targeted for proliferation, differentiation and carcinogenesis. Therefore, to assess the precise significance of Id-1 in mammary biology and carcinogenesis, we examined its cellular localization in vivo using immunohistochemistry. Extracts of whole mammary glands from wild type and Id-1 null mutant mice, and tissue sections from paraffin-embedded mouse mammary glands from various developmental stages and normal human breast were subjected to immunoblot and immunohistochemical analyses, respectively. In both these procedures, an anti-Id-1 rabbit polyclonal antibody was used for detection of Id-1. In immunoblot analyses, using whole mammary gland extracts, Id-1 was detected. In immunohistochemical analyses, however, Id-1 was not detected in the luminal epithelial cells of mammary glands during any stage of development, but it was detected in vascular endothelial cells. Id-1 is not expressed in the luminal epithelial cells of mammary glands
11. Luminal and basolateral uptake of insulin in isolated perfused, proximal tubules
International Nuclear Information System (INIS)
Nielsen, S.; Nielsen, J.T.; Christensen, E.I.
1987-01-01
The present study was performed to quantitate compare the luminal and the peritubular uptake of 125 I-insulin in isolated, perfused, proximal tubules from rabbit kidneys. 125 I-insulin was added in physiological concentrations to either the perfusate or the bath fluid for 30 min. The luminal uptake in 30 min averaged 0.76 pg/mm at physiological concentrations and 18.0 pg/mm at high insulin concentrations. About 15-41% of the absorbed insulin was digested and 125 I-insulin at physiological and high concentrations in the bath was 0.136 and 0.318 pg, respectively. The data indicates that insulin is bound/absorbed at the basolateral membranes both by a saturable specific mechanism and a nonspecific, nonsaturable mechanism. The basolateral absorption constituted 15.2 and 1.8% of the total tubular extraction of insulin at physiological and high insulin concentrations, respectively. Electron microscope autoradiography showed that, after luminal as well as basolateral endocytosis, insulin was exclusively accumulated in endocytic vacuoles and lysosomes
12. The spectrum of dermatoscopic patterns in blue nevi.
Science.gov (United States)
Di Cesare, Antonella; Sera, Francesco; Gulia, Andrea; Coletti, Gino; Micantonio, Tamara; Fargnoli, Maria Concetta; Peris, Ketty
2012-08-01
Blue nevi are congenital or acquired, dermal dendritic melanocytic proliferations that can simulate melanocytic and nonmelanocytic lesions including melanoma, cutaneous metastasis of melanoma, Spitz/Reed nevi, and basal cell carcinoma. We sought to investigate global and local dermatoscopic patterns of blue nevi compared with melanomas and basal cell carcinomas. We retrospectively analyzed global and local features in 95 dermatoscopic images of blue nevi and in 190 melanomas and basal cell carcinomas that were selected as control lesions on the basis of similar pigmentation. Lesion pigmentation was classified as monochromatic, dichromatic, or multichromatic. A global pattern characterized by homogeneous pigmentation was observed in all of 95 (100%) blue nevi. Eighty of 95 (84.2%) blue nevi presented a homogeneous pattern consisting of one color (blue, black, or brown) or two colors (blue-brown, blue-gray, or blue-black). Fifteen of 95 (15.8%) blue nevi had a multichromatic (blue, gray, black, brown, and/or red) pigmentation. In all, 47 of 95 (49.5%) blue nevi were characterized by pigmentation in the absence of pigment network or any other local dermatoscopic features. And 48 of 95 (50.5%) blue nevi showed local dermatoscopic patterns including whitish scarlike depigmentation, dots/globules, vascular pattern, streaks, and networklike pattern. The study was retrospective and involved only Caucasian people of Italian origin. The characteristic feature of blue nevi is a homogeneous pigmentation that is blue, blue-gray, blue-brown, or blue-black. We showed that a wide spectrum of local dermatoscopic features (whitish scarlike depigmentation, dots/globules, peripheral streaks or vessels) may also be present. In such cases, clinical and dermatoscopic distinction from melanoma or nonmelanocytic lesions may be difficult or impossible, and surgical excision is necessary. Copyright © 2011 American Academy of Dermatology, Inc. Published by Mosby, Inc. All rights reserved.
13. Direct sequencing of mitochondrial DNA detects highly divergent haplotypes in blue marlin (Makaira nigricans).
Science.gov (United States)
Finnerty, J R; Block, B A
1992-06-01
We were able to differentiate between species of billfish (Istiophoridae family) and to detect considerable intraspecific variation in the blue marlin (Makaira nigricans) by directly sequencing a polymerase chain reaction (PCR)-amplified, 612-bp fragment of the mitochondrial cytochrome b gene. Thirteen variable nucleotide sites separated blue marlin (n = 26) into 7 genotypes. On average, these genotypes differed by 5.7 base substitutions. A smaller sample of swordfish from an equally broad geographic distribution displayed relatively little intraspecific variation, with an average of 1.3 substitutions separating different genotypes. A cladistic analysis of blue marlin cytochrome b variants indicates two major divergent evolutionary lines within the species. The frequencies of these two major evolutionary lines differ significantly between Atlantic and Pacific ocean basins. This finding is important given that the Atlantic stocks of blue marlin are considered endangered. Migration from the Pacific can help replenish the numbers of blue marlin in the Atlantic, but the loss of certain mitochondrial DNA haplotypes in the Atlantic due to overfishing probably could not be remedied by an influx of Pacific fish because of their absence in the Pacific population. Fishery management strategies should attempt to preserve the genetic diversity within the species. The detection of DNA sequence polymorphism indicates the utility of PCR technology in pelagic fishery genetics.
14. An extremely luminous and variable ultraluminous x-ray source in the outskirts of circinus observed with NuSTAR
DEFF Research Database (Denmark)
Walton, D. J.; Fuerst, F.; Harrison, F.
2013-01-01
Following a serendipitous detection with the Nuclear Spectroscopic Telescope Array (NuSTAR), we present a multi-epoch spectral and temporal analysis of an extreme ultraluminous X-ray source (ULX) located in the outskirts of the Circinus galaxy, hereafter Circinus ULX5, including coordinated XMM-N...
15. High-Risk Premenopausal Luminal A Breast Cancer Patients Derive no Benefit from Adjuvant Cyclophosphamide-based Chemotherapy
DEFF Research Database (Denmark)
Nielsen, Torsten O; Jensen, Maj-Brit; Burugu, Samantha
2017-01-01
Purpose: Luminal A breast cancers have better prognosis than other molecular subtypes. Luminal A cancers may also be insensitive to adjuvant chemotherapy, although there is little high-level evidence to confirm this concept. The primary hypothesis in this formal prospective-retrospective analysis...... was to assess interaction between subtype (Luminal A vs. other) and treatment (chemotherapy vs. not) for the primary endpoint (10-year invasive disease-free survival) of a breast cancer trial randomizing women to adjuvant chemotherapy, analyzed in multivariate Cox proportional hazards models using the Wald...... interval (CI), 0.53-2.14; P = 0.86], whereas patients with non-luminal A subtypes did (HR, 0.50; 95% CI, 0.38-0.66; P breast cancers did not benefit from adjuvant...
16. The Research Search For The Least Beneficial Overcast Sky And Progress In Defining Its Luminance Gradation Function
Directory of Open Access Journals (Sweden)
Kittler R.
2014-09-01
Full Text Available Recently illuminance levels under ISO/CIE homogeneous standard sky types were characterised in their relative terms after ISO/CIE (2004, 2003 standardised as normalised by the luminance in the zenith. Sky luminance and horizontal illuminance based on the gradation and scattering indicatrix functions, including the extreme overcast cases frequently encountered in nature, were recently determined in absolute physical units of luminance in kilocandles per meter square and of illuminance in kilolux. The historical search to find energy and visibility critical sky luminance distributions shows a progression of steps in studying the worst or critical overcast situations. That progression has enabled the determination and evaluation of interior illuminance for comparison of the merits of dual daylighting and artificial lighting under established criteria for comfortable visibility.
17. Pectoral sound generation in the blue catfish Ictalurus furcatus.
Science.gov (United States)
Mohajer, Yasha; Ghahramani, Zachary; Fine, Michael L
2015-03-01
Catfishes produce pectoral stridulatory sounds by "jerk" movements that rub ridges on the dorsal process against the cleithrum. We recorded sound synchronized with high-speed video to investigate the hypothesis that blue catfish Ictalurus furcatus produce sounds by a slip-stick mechanism, previously described only in invertebrates. Blue catfish produce a variably paced series of sound pulses during abduction sweeps (pulsers) although some individuals (sliders) form longer duration sound units (slides) interspersed with pulses. Typical pulser sounds are evoked by short 1-2 ms movements with a rotation of 2°-3°. Jerks excite sounds that increase in amplitude after motion stops, suggesting constructive interference, which decays before the next jerk. Longer contact of the ridges produces a more steady-state sound in slides. Pulse pattern during stridulation is determined by pauses without movement: the spine moves during about 14 % of the abduction sweep in pulsers (~45 % in sliders) although movement appears continuous to the human eye. Spine rotation parameters do not predict pulse amplitude, but amplitude correlates with pause duration suggesting that force between the dorsal process and cleithrum increases with longer pauses. Sound production, stimulated by a series of rapid movements that set the pectoral girdle into resonance, is caused by a slip-stick mechanism.
18. Effects of luminal flow and nucleotides on [Ca(2+)](i) in rabbit cortical collecting duct.
Science.gov (United States)
Woda, Craig B; Leite, Maurilo; Rohatgi, Rajeev; Satlin, Lisa M
2002-09-01
Nucleotide binding to purinergic P2 receptors contributes to the regulation of a variety of physiological functions in renal epithelial cells. Whereas P2 receptors have been functionally identified at the basolateral membrane of the cortical collecting duct (CCD), a final regulatory site of urinary Na(+), K(+), and acid-base excretion, controversy exists as to whether apical purinoceptors exist in this segment. Nor has the distribution of receptor subtypes present on the unique cell populations that constitute Ca(2+) the CCD been established. To examine this, we measured nucleotide-induced changes in intracellular Ca(2+) concentration ([Ca(2+)](i)) in fura 2-loaded rabbit CCDs microperfused in vitro. Resting [Ca(2+)](i) did not differ between principal and intercalated cells, averaging approximately 120 nM. An acute increase in tubular fluid flow rate, associated with a 20% increase in tubular diameter, led to increases in [Ca(2+)](i) in both cell types. Luminal perfusion of 100 microM UTP or ATP-gamma-S, in the absence of change in flow rate, caused a rapid and transient approximately fourfold increase in [Ca(2+)](i) in both cell types (P < 0.05). Luminal suramin, a nonspecific P2 receptor antagonist, blocked the nucleotide- but not flow-induced [Ca(2+)](i) transients. Luminal perfusion with a P2X (alpha,beta-methylene-ATP), P2X(7) (benzoyl-benzoyl-ATP), P2Y(1) (2-methylthio-ATP), or P2Y(4)/P2Y(6) (UDP) receptor agonist had no effect on [Ca(2+)](i). The nucleotide-induced [Ca(2+)](i) transients were inhibited by the inositol-1,4,5-triphosphate receptor blocker 2-aminoethoxydiphenyl borate, thapsigargin, which depletes internal Ca(2+) stores, luminal perfusion with a Ca(2+)-free perfusate, or the L-type Ca(2+) channel blocker nifedipine. These results suggest that luminal nucleotides activate apical P2Y(2) receptors in the CCD via pathways that require both internal Ca(2+) mobilization and extracellular Ca(2+) entry. The flow-induced rise in [Ca(2+)](i) is
19. Contribution of a luminance-dependent S-cone mechanism to non-assimilative color spreading in the watercolor configuration.
Science.gov (United States)
Kimura, Eiji; Kuroki, Mikako
2014-01-01
20. Contribution of a luminance-dependent S-cone mechanism to non-assimilative color spreading in the watercolor configuration
Directory of Open Access Journals (Sweden)
Eiji eKimura
2014-12-01
1. A longitudinal study of perceptual grouping by proximity, luminance and shape in infants at two, four and six months
OpenAIRE
Farran, E. K.; Brown, J. H.; Cole, V. L.; Houston-Price, C.; Karmiloff-Smith, A.
2008-01-01
Grouping by luminance and shape similarity has previously been demonstrated in neonates and at 4 months, respectively. By contrast, grouping by proximity has hitherto not been investigated in infancy. This is also the first study to chart the developmental emergence of perceptual grouping longitudinally. Sixty-one infants were presented with a matrix of local stimuli grouped horizontally or vertically by luminance, shape or proximity at 2, 4, and 6 months. Infants were exposed to each set of ...
2. The effect of a charge control layer on the electroluminescent characteristic of blue and white organic light-emitting diodes.
Science.gov (United States)
Lee, Dong Hyung; Lee, Seok Jae; Koo, Ja-Ryong; Lee, Ho Won; Shin, Hyun Su; Lee, Song Eun; Kim, Woo Young; Lee, Kum Hee; Yoon, Seung Soo; Kim, Young Kwan
2014-08-01
We investigated blue fluorescent organic light-emitting diode (OLED) with a charge control layer (CCL) to produce high efficiency and improve the half-decay lifetime. Three types of devices (device A, B, and C) were fabricated following the number of CCLs within the emitting layer (EML), maintaining the thickness of whole EML. The CCL and host material, 2-methyl-9,10-di(2-naphthyl)anthracene, which has a bipolar property, was able to control the carrier movement with ease inside the EML. Device B demonstrated a maximum luminous efficiency (LE) and external quantum efficiency (EQE) of 9.19 cd/A and 5.78%, respectively. It also showed that the enhancement of the half-decay lifetime, measured at an initial luminance of 1,000 cd/m2, was 1.5 times longer than that of the conventional structure. A hybrid white OLED (WOLED) was also fabricated using a phosphorescent red emitter, bis(2-phenylquinoline)-acetylacetonate iridium III doped in 4,4'-N,N'-dicarbazolyl-biphenyl. The property of the hybrid WOLED with CCL showed a maximum LE and an EQE of 13.46 cd/A and 8.32%, respectively. It also showed white emission with Commission International de L'Éclairage coordinates of (x = 0.41, y = 0.33) at 10 V.
3. Coomassie Brilliant Blue G is a more potent antagonist of P2 purinergic responses than Reactive Blue 2 (Cibacron Blue 3GA) in rat parotid acinar cells
International Nuclear Information System (INIS)
Soltoff, S.P.; McMillian, M.K.; Talamo, B.R.
1989-01-01
The ability of Brilliant Blue G (Coomassie Brilliant Blue G) and Reactive Blue 2 (Cibacron Blue 3GA) to block the effects of extracellular ATP on rat parotid acinar cells was examined by evaluating their effects on ATP-stimulated 45Ca 2+ entry and the elevation of [Ca 2+ ]i (Fura 2 fluorescence). ATP (300 microM) increased the rate of Ca 2+ entry to more than 25-times the basal rate and elevated [Ca 2+ ]i to levels more than three times the basal value. Brilliant Blue G and Reactive Blue 2 greatly reduced the entry of 45 Ca 2+ into parotid cells, but the potency of Brilliant Blue G (IC50 approximately 0.4 microM) was about 100-times that of Reactive Blue 2. Fura 2 studies demonstrated that inhibitory concentrations of these compounds did not block the cholinergic response of these cells, thus demonstrating the selectivity of the dye compounds for purinergic receptors. Unlike Reactive Blue 2, effective concentrations of Brilliant Blue G did not substantially quench Fura 2 fluorescence. The greater potency of Brilliant Blue G suggests that it may be very useful in identifying P2-type purinergic receptors, especially in studies which utilize fluorescent probes
4. Spectra and ages of blue stragglers
International Nuclear Information System (INIS)
Abt, H.A.
1985-01-01
A mechanism similar to Wheeler's quasi-homogeneous evolution and Finzi and Wolf's proposal for blue stragglers is proposed as the origin of the blue stragglers in intermediate-age clusters. Blue stragglers are stars whose positions in color-magnitude diagrams of open and globular clusters are significantly above the turn-off points and in the region of the (former) main sequence; they seem to represent a conflict with the general conclusion that all stars in a cluster originated at about the same time. It is concluded that there are at least two kinds of blue stragglers: (1) those stars of types about B3-A2 are primarily Ap stars and slow rotators, occur in the intermediate age clusters and remain in the main sequence region probably through magnetic mixing; and (2) the stars of type O6-B2 frequently have emission lines, are rapid rotators, occur in the young cluster, and remain in the main sequence region probably by rotational mixing. 30 references
5. Prussian Blue Analogues of Reduced Dimensionality
NARCIS (Netherlands)
Gengler, Regis Y. N.; Toma, Luminita M.; Pardo, Emilio; Lloret, Francesc; Ke, Xiaoxing; Van Tendeloo, Gustaaf; Gournis, Dimitrios; Rudolf, Petra
2012-01-01
Mixed-valence polycyanides (Prussian Blue analogues) possess a rich palette of properties spanning from room-temperature ferromagnetism to zero thermal expansion, which can be tuned by chemical modifications or the application of external stimuli (temperature, pressure, light irradiation). While
6. Blue whales respond to anthropogenic noise.
Directory of Open Access Journals (Sweden)
Mariana L Melcón
Full Text Available Anthropogenic noise may significantly impact exposed marine mammals. This work studied the vocalization response of endangered blue whales to anthropogenic noise sources in the mid-frequency range using passive acoustic monitoring in the Southern California Bight. Blue whales were less likely to produce calls when mid-frequency active sonar was present. This reduction was more pronounced when the sonar source was closer to the animal, at higher sound levels. The animals were equally likely to stop calling at any time of day, showing no diel pattern in their sensitivity to sonar. Conversely, the likelihood of whales emitting calls increased when ship sounds were nearby. Whales did not show a differential response to ship noise as a function of the time of the day either. These results demonstrate that anthropogenic noise, even at frequencies well above the blue whales' sound production range, has a strong probability of eliciting changes in vocal behavior. The long-term implications of disruption in call production to blue whale foraging and other behaviors are currently not well understood.
7. African Retentions in Blues and Jazz.
Science.gov (United States)
1979-01-01
The perseverance of African musical characteristics among American Blacks is an historic reality. African retentions have been recorded in Black music of the antebellum period. Various African scales and rhythms permeate Black American music today as evidenced in the retentions found in blues and jazz. (RLV)
8. Nanotubes based on monolayer blue phosphorus
KAUST Repository
Montes Muñoz, Enrique
2016-07-08
We demonstrate structural stability of monolayer zigzag and armchair blue phosphorus nanotubes by means of molecular dynamics simulations. The vibrational spectrum and electronic band structure are determined and analyzed as functions of the tube diameter and axial strain. The nanotubes are found to be semiconductors with a sensitive indirect band gap that allows flexible tuning.
9. Improper, Blue-Shifting Hydrogen Bond
Czech Academy of Sciences Publication Activity Database
Hobza, Pavel; Havlas, Zdeněk
2002-01-01
Roč. 108, - (2002), s. 325-334 ISSN 1432-881X R&D Projects: GA MŠk LN00A032 Institutional research plan: CEZ:AV0Z4055905; CEZ:AV0Z4040901 Keywords : improper, blue-shifting hydrogen bond * properties * nature Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.421, year: 2002
10. Blue laser phase change recording system
International Nuclear Information System (INIS)
Hofmann, Holger; Dambach, S.Soeren; Richter, Hartmut
2002-01-01
The migration paths from DVD phase change recording with red laser to the next generation optical disk formats with blue laser and high NA optics are discussed with respect to optical aberration margins and disc capacities. A test system for the evaluation of phase change disks with more than 20 GB capacity is presented and first results of the recording performance are shown
11. Biodecolorization and biodegradation of Reactive Blue by ...
African Journals Online (AJOL)
SERVER
2007-06-18
Jun 18, 2007 ... Aspergillus sp. effectively decolorized Reactive Blue and other structurally different synthetic dyes. Agitation was found to be an important ... Few chemically different dyes such as Reactive Black (75%), Reactive Yellow (70%),. Reactive Red (33%) and ..... Degradation of azo dyes by the lignin degrading ...
12. T's and Blues. Specialized Information Service.
Science.gov (United States)
Do It Now Foundation, Phoenix, AZ.
This compilation of journal articles provides basic information on abuse of Talwin, a mild prescription painkiller (T's), and Pyribenzamine, a nonprescription antihistimine (Blues). These two drugs, taken in combination, produce an effect similar to that produced by heroin. Stories from "Drug Survival News,""Emergency…
13. [The dangers of blue light: True story!].
Science.gov (United States)
Renard, G; Leid, J
2016-05-01
The dangers of the blue light are the object of numerous publications, for both the scientific community and the general public. The new prolific development of light sources emitting potentially toxic blue light (415-455nm) ranges from LED (Light Emitting Diodes) lamps for interior lighting to television screens, computers, digital tablets and smartphones using OLED (Organic Light Emitting Diode) or AMOLED (Active-Matrix Organic Light Emitting Diode) technology. First we will review some technical terms and the main characteristics of light perceived by the human eye. Then we will discuss scientific proof of the toxicity of blue light to the eye, which may cause cataract or macular degeneration. Analysis of the light spectra of several light sources, from natural light to LED lamps, will allow us to specify even better the dangers related to each light source. LED lamps, whether used as components for interior lighting or screens, are of concern if they are used for extended viewing times and at short distance. While we can protect ourselves from natural blue light by wearing colored glasses which filter out, on both front and back surfaces, the toxic wavelengths, it is more difficult to protect oneself from LED lamps in internal lighting, the use of which should be restricted to "white warmth" lamps (2700K). As far as OLED or AMOLED screens are concerned, the only effective protection consists of using them occasionally and only for a short period of time. Copyright © 2016 Elsevier Masson SAS. All rights reserved.
14. Blue LED irradiation to hydration of skin
Science.gov (United States)
Menezes, Priscila F. C.; Requena, Michelle B.; Lizarelli, Rosane F., Z.; Bagnato, Vanderlei S.
2015-06-01
Blue LED system irradiation shows many important properties on skin as: bacterial decontamination, degradation of endogenous skin chromophores and biostimulation. In this clinical study we prove that the blue light improves the skin hydration. In the literature none authors reports this biological property on skin. Then this study aims to discuss the role of blue light in the skin hydration. Twenty patients were selected to this study with age between 25-35 years old and phototype I, II and III. A defined area from forearm was pre determined (A = 4.0 cm2). The study was randomized in two treatment groups using one blue light device (power of 5.3mW and irradiance of 10.8mW/cm2). The first treatment group was irradiated with 3J/cm2 (277seconds) and the second with 6J/cm2 (555 seconds). The skin hydration evaluations were done using a corneometer. The measurements were collected in 7, 14, 21 and 30 days, during the treatment. Statistical test of ANOVA, Tukey and T-Student were applied considering 5% of significance. In conclusion, both doses were able to improve the skin hydration; however, 6J/cm2 has kept this hydration for 30 days.
15. Biodecolorization and biodegradation of Reactive Blue by ...
African Journals Online (AJOL)
Aspergillus sp. effectively decolorized Reactive Blue and other structurally different synthetic dyes. Agitation was found to be an important parameter, while glucose (99%), sucrose (97%) and mannitol (98%) were the best carbon sources for the decolorization. Decolorization was effective in an acidic environment (pH 3).
16. Visual sensitivity for luminance and chromatic stimuli during the execution of smooth pursuit and saccadic eye movements.
Science.gov (United States)
Braun, Doris I; Schütz, Alexander C; Gegenfurtner, Karl R
2017-07-01
17. The lithium abundance of M67 blue stragglers - A constraint on the blue straggler phenomenon
International Nuclear Information System (INIS)
Pritchet, C.J.; Glaspey, J.W.
1991-01-01
Upper limits have been placed on the line strength of the 6707 A Li I resonance doublet in seven blue stragglers in M67. The corresponding upper limits on abundances range from log N(Li) less than about 1.3 to less than about 2.3. This result is significantly below the level of log N(Li) about 3.1 + or - 0.1 found in field main-sequence stars of comparable temperature. It is concluded that some form of mixing has affected the outer envelopes of blue stragglers. (Such mixing has been proposed as the mechanism needed to prolong the lifetimes of blue stragglers relative to normal main-sequence stars at the same luminosity). Virtually all mechanisms for the production of blue stragglers other than mixing, binary mass transfer, or binary coalescence appear to be ruled out by the present observations. 45 refs
18. Blue objects in the vicinity of M13. 1
International Nuclear Information System (INIS)
Oganesyan, Eh.Ya.
1978-01-01
Presented are photometric data in the UBV system for 225 objects in the region of 16 square degrees in size, adjacent to M13 cluster. ''Two-colour diagram'' and ''colour-luminosity'' diagram are built, and on their basis analysis of the data obtained is made. Half the objects investigated are subdwarfs. Among others there are white - blue dwarfs conventional stars of the main sequence stars, halo stars, stars of globular clusters and objects, which might be of extragalactic nature. On the basis of object distribution as to brightness and colour, and also according to their visible distribution several different groups can be singled out. Several variable stars are also found as a result of photometric investigation
19. The water use of Indian diets and socio-demographic factors related to dietary blue water footprint.
Science.gov (United States)
Harris, Francesca; Green, Rosemary F; Joy, Edward J M; Kayatz, Benjamin; Haines, Andy; Dangour, Alan D
2017-06-01
20. Blue-light emitting triazolopyridinium and triazoloquinolinium salts
KAUST Repository
Carboni, Valentina; Su, Xin; Qian, Hai; Aprahamian, Ivan; Credi, Alberto
2017-01-01
Compounds that emit blue light are of interest for applications that include optoelectronic devices and chemo/biosensing and imaging. The design and synthesis of small organic molecules that can act as high-efficiency deep-blue-light emitters
1. Eggshell spottiness reflects maternally transferred antibodies in blue tits.
Directory of Open Access Journals (Sweden)
Marie-Jeanne Holveck
Full Text Available Blue-green and brown-spotted eggshells in birds have been proposed as sexual signals of female physiological condition and egg quality, reflecting maternal investment in the egg. Testing this hypothesis requires linking eggshell coloration to egg content, which is lacking for brown protoporphyrin-based pigmentation. As protoporphyrins can induce oxidative stress, and a large amount in eggshells should indicate either high female and egg quality if it reflects the female's high oxidative tolerance, or conversely poor quality if it reflects female physiological stress. Different studies supported either predictions but are difficult to compare given the methodological differences in eggshell-spottiness measurements. Using the blue tit Cyanistes caeruleus as a model species, we aimed at disentangling both predictions in testing if brown-spotted eggshell could reflect the quality of maternal investment in antibodies and carotenoids in the egg, and at improving between-study comparisons in correlating several common measurements of eggshell coloration (spectral and digital measures, spotted surface, pigmentation indices. We found that these color variables were weakly correlated highlighting the need for comparable quantitative measurements between studies and for multivariate regressions incorporating several eggshell-color characteristics. When evaluating the potential signaling function of brown-spotted eggshells, we thus searched for the brown eggshell-color variables that best predicted the maternal transfer of antibodies and carotenoids to egg yolks. We also tested the effects of several parental traits and breeding parameters potentially affecting this transfer. While eggshell coloration did not relate to yolk carotenoids, the eggs with larger and less evenly-distributed spots had higher antibody concentrations, suggesting that both the quantity and distribution of brown pigments reflected the transfer of maternal immune compounds in egg yolks
2. Unraveling the Mystery of the Blue Fog: Structure, Properties, and Applications of Amorphous Blue Phase III.
Science.gov (United States)
Gandhi, Sahil Sandesh; Chien, Liang-Chy
2017-12-01
The amorphous blue phase III of cholesteric liquid crystals, also known as the "blue fog," are among the rising stars in materials science that can potentially be used to develop next-generation displays with the ability to compete toe-to-toe with disruptive technologies like organic light-emitting diodes. The structure and properties of the practically unobservable blue phase III have eluded scientists for more than a century since it was discovered. This progress report reviews the developments in this field from both fundamental and applied research perspectives. The first part of this progress report gives an overview of the 130-years-long scientific tour-de-force that very recently resulted in the revelation of the mysterious structure of blue phase III. The second part reviews progress made in the past decade in developing electrooptical, optical, and photonic devices based on blue phase III. The strong and weak aspects of the development of these devices are underlined and criticized, respectively. The third- and-final part proposes ideas for further improvement in blue phase III technology to make it feasible for commercialization and widespread use. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
3. The Blue Coma: The Role of Methylene Blue in Unexplained Coma After Cardiac Surgery.
Science.gov (United States)
Martino, Enrico Antonio; Winterton, Dario; Nardelli, Pasquale; Pasin, Laura; Calabrò, Maria Grazia; Bove, Tiziana; Fanelli, Giovanna; Zangrillo, Alberto; Landoni, Giovanni
2016-04-01
Methylene blue commonly is used as a dye or an antidote, but also can be used off label as a vasopressor. Serotonin toxicity is a potentially lethal and often misdiagnosed condition that can result from drug interaction. Mild serotonin toxicity previously was reported in settings in which methylene blue was used as a dye. The authors report 3 cases of life-threatening serotonin toxicity in patients undergoing chronic selective serotonin reuptake inhibitor (SSRI) therapy who also underwent cardiac surgery and received methylene blue to treat vasoplegic syndrome. An observational study. A cardiothoracic intensive care unit (ICU) in a teaching hospital. Three patients who received methylene blue after cardiac surgery, later discovered to be undergoing chronic SSRI therapy. None. All 3 patients received high doses of fentanyl during general anesthesia. They all developed vasoplegic syndrome and consequently were given methylene blue in the ICU. All 3 patients developed serotonin toxicity, including coma, after this administration and diagnostic tests were negative for acute intracranial pathology. Coma lasted between 1 and 5 days. Two patients were discharged from the ICU shortly after awakening, whereas the third patient experienced a complicated postoperative course for concomitant refractory low-cardiac-output syndrome. Patients undergoing chronic SSRI therapy should not be administered methylene blue to treat vasoplegic syndrome. Copyright © 2016 Elsevier Inc. All rights reserved.
4. Aspen biology, community classification, and management in the Blue Mountains
Science.gov (United States)
David K. Swanson; Craig L. Schmitt; Diane M. Shirley; Vicky Erickson; Kenneth J. Schuetz; Michael L. Tatum; David C. Powell
2010-01-01
Quaking aspen (Populus tremuloides Michx.) is a valuable species that is declining in the Blue Mountains of northeastern Oregon. This publication is a compilation of over 20 years of aspen management experience by USDA Forest Service workers in the Blue Mountains. It includes a summary of aspen biology and occurrence in the Blue Mountains, and a...
5. Alcian blue-stained particles in a eutrophic lake
DEFF Research Database (Denmark)
Worm, J.; Søndergaard, Morten
1998-01-01
We used a neutral solution of Alcian Blue to stain transparent particles in eutrophic Lake Frederiksborg Slotss0, Denmark. Alcian Blue-stained particles (ABSP) appeared to be similar to the so-called transparent exopolymer particles (TEP) identified with an acidic solution of Alcian Blue. Our...
6. Blue whales Balaenoptera musculus off Angola: recent sightings ...
African Journals Online (AJOL)
Further survey work is required to better clarify the status of blue whales in Angolan waters, particularly with regard to population structure and potential calving grounds. Keywords: Antarctic blue whale, calving, catch data, pygmy blue whale, South-East Atlantic, stomach contents. African Journal of Marine Science 2014, ...
7. Blue light phototherapy for Psoriasis from a systems biology perspective
NARCIS (Netherlands)
Félix Garza, Z.C.; Liebmann, J.; Hilbers, P.A.J.; Riel, van N.A.W.
2014-01-01
This work analyses the effect of UV-free blue light (BL) irradiation of the skin using mathematical modelling. Prior research has shown that blue light reduces the proliferation of keratinocytes by inducing their differentiation, and causes apoptosis of lymphocytes. The effects of blue light on
8. FIXED-BED COLUMN ADSORPTION OF METHYL BLUE USING ...
African Journals Online (AJOL)
userpc
Axle Wood Carbon (AWC) was used to study the removal of Methyl Blue (MB) from ... height, initial methyl blue (MB) concentration, .... colour from blue to dark purple- .... Environ. Earth Sci. 13; 1–13. Yagub, M. T., Sen, T. K., Afroze, S., and Ang,.
9. Pulsating variables
International Nuclear Information System (INIS)
1989-01-01
The study of stellar pulsations is a major route to the understanding of stellar structure and evolution. At the South African Astronomical Observatory (SAAO) the following stellar pulsation studies were undertaken: rapidly oscillating Ap stars; solar-like oscillations in stars; 8-Scuti type variability in a classical Am star; Beta Cephei variables; a pulsating white dwarf and its companion; RR Lyrae variables and galactic Cepheids. 4 figs
10. Poporodní blues – česká adaptace dotazníku „Maternity blues questionnaire“
Czech Academy of Sciences Publication Activity Database
Takács, L.; Smolík, Filip; Mlíková Seidlerová, J.; Čepický, P.; Hoskovcová, S.
2016-01-01
Roč. 81, č. 5 (2016), s. 355-368 ISSN 1210-7832 Institutional support: RVO:68081740 Keywords : EPDS postpartum mood * Maternity Blues Questionnaire * postnatal depression * postpartum blues * postpartum depression Subject RIV: AN - Psychology
11. Fabrication of nerve guidance conduit with luminal filler as scaffold for peripheral nerve repair
International Nuclear Information System (INIS)
Aranilla, Charito T.; Wach, Rodoslaw; Ulanski, Piotr
2015-01-01
Peripheral nerve injury is a serious health concern for society, affecting trauma patients, many of whom acquire life-long disability. The gold standard of treatment for peripheral nerve injury is the use of nerve grafts, wherein nerve autograft or allograft is used to bridge the gap in the damaged nerve. Nerve guidance conduits (NGCs) are an attractive alternative to nerve autografts for aiding in the regeneration of peripheral nerve tissue. NGCs are small cylinders or tubes composed of either natural or synthetic biomaterials that are used to axon regeneration. The ends of the damaged nerve are inserted into either end of the cylinder and the NGC acts both as a connecting bridge for the severed nerve ends as well as a protective shelter for the regenerating nerve. This study aims at fabricating nerve guidance conduits with luminal structure based on synthetic biodegradable and biocompatible polymers such as poly (trimethylene carbonate ) (PTMC), poly (lactic acid) (PLA) and poly (caprolactone) (PCL). Initial base materials for fabrication were PLA acid tubes compared to PCL tubes when prepared by spray and dip-coating methods. The morphology of the tubes where examined by SEM and results showed better porosity of PLA acid tubes compared to PCL tubes when prepared by spraying technique. Poly(lactic acid) was then blended with poly(trimethylene carbonate) at a ratio of 1:4 (5% total polymer content) for further fabrication. Electron beam radiation (25 and 50 kGy) was employed for sterilization and the changes in properties induced by irradiation in comprising polymers were evaluated. The wettability, mechanical thermal properties were not significantly changed by irradiation.In a separate experiment, synthesis of carboxymethyl chitosan hydrogel crosslinked by electron beam radiation was studied to create a luminal filler for PTMC-PLA tubes. Based on proper viscosity of solution before crosslinking, sufficient gel fraction and swelling, 10% w/v concentration of
12. Total molecular gas masses of Planck - Herschel selected strongly lensed hyper luminous infrared galaxies
Science.gov (United States)
Harrington, K. C.; Yun, M. S.; Magnelli, B.; Frayer, D. T.; Karim, A.; Weiß, A.; Riechers, D.; Jiménez-Andrade, E. F.; Berman, D.; Lowenthal, J.; Bertoldi, F.
2018-03-01
We report the detection of CO(1-0) line emission from seven Planck and Herschel selected hyper luminous ({L_{IR (8-1000{μ m})} > 10^{13} L_{⊙}) infrared galaxies with the Green Bank Telescope (GBT). CO(1-0) measurements are a vital tool to trace the bulk molecular gas mass across all redshifts. Our results place tight constraints on the total gas content of these most apparently luminous high-z star-forming galaxies (apparent IR luminosities of LIR > 1013 - 14 L⊙), while we confirm their predetermined redshifts measured using the Large Millimeter Telescope, LMT (zCO = 1.33-3.26). The CO(1-0) lines show similar profiles as compared to Jup = 2-4 transitions previously observed with the LMT. We report enhanced infrared to CO line luminosity ratios of = 110 ± 22 L_{⊙} (K km s^{-1} pc^{-2})^{-1} compared to normal star-forming galaxies, yet similar to those of well-studied IR-luminous galaxies at high-z. We find average brightness temperature ratios of 〈 r21〉 = 0.93 (2 sources), 〈 r31〉 = 0.34 (5 sources), and 〈 r41〉 = 0.18 (1 source). The r31 and r41 values are roughly half the average values for SMGs. We estimate the total gas mass content as {μ M_{H2} = (0.9-27.2) × 10^{11} (α _CO/0.8) M_{⊙}, where μ is the magnification factor and αCO is the CO line luminosity to molecular hydrogen gas mass conversion factor. The rapid gas depletion times, = 80} Myr, reveal vigorous starburst activity, and contrast the Gyr depletion time-scales observed in local, normal star-forming galaxies.
13. Luminance noise as a novel approach for measuring contrast sensitivity within the magnocellular and parvocellular pathways.
Science.gov (United States)
Hall, Cierra M; McAnany, J Jason
2017-07-01
This study evaluated the extent to which different types of luminance noise can be used to target selectively the inferred magnocellular (MC) and parvocellular (PC) visual pathways. Letter contrast sensitivity (CS) was measured for three visually normal subjects for letters of different size (0.8°-5.3°) under established paradigms intended to target the MC pathway (steady-pedestal paradigm) and PC pathway (pulsed-pedestal paradigm). Results obtained under these paradigms were compared to those obtained in asynchronous static noise (a field of unchanging luminance noise) and asynchronous dynamic noise (a field of randomly changing luminance noise). CS was measured for letters that were high- and low-pass filtered using a range of filter cutoffs to quantify the object frequency information (cycles per letter) mediating letter identification, which was used as an index of the pathway mediating CS. A follow-up experiment was performed to determine the range of letter duration over which MC and PC pathway CS can be targeted. Analysis of variance indicated that the object frequencies measured under the static noise and steady-pedestal paradigms did not differ significantly (p ≥ 0.065), but differed considerably from those measured under the dynamic noise (both p noise, and in dynamic noise. These data suggest that the spatiotemporal characteristics of noise can be manipulated to target the inferred MC (static noise) and PC (dynamic noise) pathways. The results also suggest that CS within these pathways can be measured at long stimulus durations, which has potential importance in the design of future clinical CS tests.
14. A plausible (overlooked) super-luminous supernova in the Sloan digital sky survey stripe 82 data
International Nuclear Information System (INIS)
Kostrzewa-Rutkowska, Zuzanna; Kozłowski, Szymon; Wyrzykowski, Łukasz; Djorgovski, S. George; Mahabal, Ashish A.; Glikman, Eilat; Koposov, Sergey
2013-01-01
We present the discovery of a plausible super-luminous supernova (SLSN), found in the archival data of Sloan Digital Sky Survey (SDSS) Stripe 82, called PSN 000123+000504. The supernova (SN) peaked at m g < 19.4 mag in the second half of 2005 September, but was missed by the real-time SN hunt. The observed part of the light curve (17 epochs) showed that the rise to the maximum took over 30 days, while the decline time lasted at least 70 days (observed frame), closely resembling other SLSNe of SN 2007bi type. The spectrum of the host galaxy reveals a redshift of z = 0.281 and the distance modulus of μ = 40.77 mag. Combining this information with the SDSS photometry, we found the host galaxy to be an LMC-like irregular dwarf galaxy with an absolute magnitude of M B = –18.2 ± 0.2 mag and an oxygen abundance of 12+log [O/H]=8.3±0.2; hence, the SN peaked at M g < –21.3 mag. Our SLSN follows the relation for the most energetic/super-luminous SNe exploding in low-metallicity environments, but we found no clear evidence for SLSNe to explode in low-luminosity (dwarf) galaxies only. The available information on the PSN 000123+000504 light curve suggests the magnetar-powered model as a likely scenario of this event. This SLSN is a new addition to a quickly growing family of super-luminous SNe.
15. The Role of the Most Luminous Obscured AGNs in Galaxy Assembly at z ∼ 2
Energy Technology Data Exchange (ETDEWEB)
Farrah, Duncan [Department of Physics, Virginia Tech, Blacksburg, VA 24061 (United States); Petty, Sara [Green Science Policy Institute, Berkeley, CA 94709 (United States); Connolly, Brian [Cincinnati Children’s Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, OH 45229 (United States); Blain, Andrew [Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH (United Kingdom); Efstathiou, Andreas [School of Sciences, European University Cyprus, Diogenes Street, Engomi, 1516 Nicosia (Cyprus); Lacy, Mark [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903 (United States); Stern, Daniel; Bridge, Carrie; Eisenhardt, Peter; Moustakas, Leonidas [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Lake, Sean; Tsai, Chao-Wei [Physics and Astronomy Department, University of California, Los Angeles, CA 90095 (United States); Jarrett, Tom [Department of Astronomy, University of Cape Town, 7700 Rondebosch, Capetown 7700 (South Africa); Benford, Dominic [Observational Cosmology Lab., Code 665, NASA at Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Jones, Suzy [Department of Space, Earth, and Environment, Chalmers University of Technology, Onsala Space Observatory, SE-43992 Onsala (Sweden); Assef, Roberto [Núcleo de Astronomía de la Facultad de Ingeniería, Universidad Diego Portales, Av. Ejército Libertador 441, Santiago (Chile); Wu, Jingwen [National Astronomical Observatories, Chinese Academy of Sciences, 20A Datun Road, Chaoyang District, Beijing, 100012 (China)
2017-08-01
We present Hubble Space Telescope WFC3 F160W imaging and infrared spectral energy distributions for 12 extremely luminous, obscured active galactic nuclei (AGNs) at 1.8 < z < 2.7 selected via “hot, dust-obscured” mid-infrared colors. Their infrared luminosities span (2–15) × 10{sup 13} L {sub ⊙}, making them among the most luminous objects in the universe at z ∼ 2. In all cases, the infrared emission is consistent with arising at least for the most part from AGN activity. The AGN fractional luminosities are higher than those in either submillimeter galaxies or AGNs selected via other mid-infrared criteria. Adopting the G , M {sub 20}, and A morphological parameters, together with traditional classification boundaries, infers that three-quarters of the sample are mergers. Our sample does not, however, show any correlation between the considered morphological parameters and either infrared luminosity or AGN fractional luminosity. Moreover, the asymmetries and effective radii of our sample are distributed identically to those of massive galaxies at z ∼ 2. We conclude that our sample is not preferentially associated with mergers, though a significant merger fraction is still plausible. Instead, we propose that our sample includes examples of the massive galaxy population at z ∼ 2 that harbor a briefly luminous, “flickering” AGN and in which the G and M {sub 20} values have been perturbed due to either the AGN and/or the earliest formation stages of a bulge in an inside-out manner. Furthermore, we find that the mass assembly of the central black holes in our sample leads the mass assembly of any bulge component. Finally, we speculate that our sample represents a small fraction of the immediate antecedents of compact star-forming galaxies at z ∼ 2.
16. Unusual broad-line Mg II emitters among luminous galaxies in the baryon oscillation spectroscopic survey
International Nuclear Information System (INIS)
Roig, Benjamin; Blanton, Michael R.; Ross, Nicholas P.
2014-01-01
Many classes of active galactic nuclei (AGNs) have been observed and recorded since the discovery of Seyfert galaxies. In this paper, we examine the sample of luminous galaxies in the Baryon Oscillation Spectroscopic Survey. We find a potentially new observational class of AGNs, one with strong and broad Mg II λ2799 line emission, but very weak emission in other normal indicators of AGN activity, such as the broad-line Hα, Hβ, and the near-ultraviolet AGN continuum, leading to an extreme ratio of broad Hα/Mg II flux relative to normal quasars. Meanwhile, these objects' narrow-line flux ratios reveal AGN narrow-line regions with levels of activity consistent with the Mg II fluxes and in agreement with that of normal quasars. These AGN may represent an extreme case of the Baldwin effect, with very low continuum and high equivalent width relative to typical quasars, but their ratio of broad Mg II to broad Balmer emission remains very unusual. They may also be representative of a class of AGN where the central engine is observed indirectly with scattered light. These galaxies represent a small fraction of the total population of luminous galaxies (≅ 0.1%), but are more likely (about 3.5 times) to have AGN-like nuclear line emission properties than other luminous galaxies. Because Mg II is usually inaccessible for the population of nearby galaxies, there may exist a related population of broad-line Mg II emitters in the local universe which is currently classified as narrow-line emitters (Seyfert 2 galaxies) or low ionization nuclear emission-line regions.
17. Coating with luminal gut-constituents alters adherence of nanoparticles to intestinal epithelial cells
Directory of Open Access Journals (Sweden)
Heike Sinnecker
2014-12-01
Full Text Available Background: Anthropogenic nanoparticles (NPs have found their way into many goods of everyday life. Inhalation, ingestion and skin contact are potential routes for NPs to enter the body. In particular the digestive tract with its huge absorptive surface area provides a prime gateway for NP uptake. Considering that NPs are covered by luminal gut-constituents en route through the gastrointestinal tract, we wanted to know if such modifications have an influence on the interaction between NPs and enterocytes.Results: We investigated the consequences of a treatment with various luminal gut-constituents on the adherence of nanoparticles to intestinal epithelial cells. Carboxylated polystyrene particles 20, 100 and 200 nm in size represented our anthropogenic NPs, and differentiated Caco-2 cells served as model for mature enterocytes of the small intestine. Pretreatment with the proteins BSA and casein consistently reduced the adherence of all NPs to the cultured enterocytes, while incubation of NPs with meat extract had no obvious effect on particle adherence. In contrast, contact with intestinal fluid appeared to increase the particle-cell interaction of 20 and 100 nm NPs.Conclusion: Luminal gut-constituents may both attenuate and augment the adherence of NPs to cell surfaces. These effects appear to be dependent on the particle size as well as on the type of interacting protein. While some proteins will rather passivate particles towards cell attachment, possibly by increasing colloid stability or camouflaging attachment sites, certain components of intestinal fluid are capable to modify particle surfaces in such a way that interactions with cellular surface structures result in an increased binding.
18. EXTENDED [C II] EMISSION IN LOCAL LUMINOUS INFRARED GALAXIES
International Nuclear Information System (INIS)
Díaz-Santos, T.; Armus, L.; Surace, J. A.; Charmandaris, V.; Stacey, G.; Murphy, E. J.; Haan, S.; Stierwalt, S.; Evans, A. S.; Malhotra, S.; Appleton, P.; Inami, H.; Magdis, G. E.; Elbaz, D.; Mazzarella, J. M.; Xu, C. K.; Lu, N.; Howell, J. H.; Van der Werf, P. P.; Meijerink, R.
2014-01-01
We present Herschel/PACS observations of extended [C II] 157.7 μm line emission detected on ∼1-10 kpc scales in 60 local luminous infrared galaxies (LIRGs) from the Great Observatories All-sky LIRG Survey. We find that most of the extra-nuclear emission show [C II]/FIR ratios ≥4 × 10 –3 , larger than the mean ratio seen in the nuclei, and similar to those found in the extended disks of normal star-forming galaxies and the diffuse interstellar medium of our Galaxy. The [C II] ''deficits'' found in the most luminous local LIRGs are therefore restricted to their nuclei. There is a trend for LIRGs with warmer nuclei to show larger differences between their nuclear and extra-nuclear [C II]/FIR ratios. We find an anti-correlation between [C II]/FIR and the luminosity surface density, Σ IR , for the extended emission in the spatially resolved galaxies. However, there is an offset between this trend and that found for the LIRG nuclei. We use this offset to derive a beam filling-factor for the star-forming regions within the LIRG disks of ∼6% relative to their nuclei. We confront the observed trend to photo-dissociation region models and find that the slope of the correlation is much shallower than the model predictions. Finally, we compare the correlation found between [C II]/FIR and Σ IR with measurements of high-redshift starbursting IR-luminous galaxies
19. Effect of luminance contrast on BOLD-fMRI response in deaf and normal occipital visual cortex
International Nuclear Information System (INIS)
Xue Yanping; Zhai Renyou; Jiang Tao; Cui Yong; Zhou Tiangang; Rao Hengyi; Zhuo Yan
2002-01-01
Objective: To examine the effect of luminance contrast stimulus by using blood oxygenation level dependent functional magnetic resonance imaging (BOLD-fMRI) within deaf occipital visual cortex, and to compare the distribution, extent, and intensity of activated areas between deaf subjects and normal hearing subjects. Methods: Twelve deaf subjects (average age 16.5) and 15 normal hearing subjects (average age 23.7) were stimulated by 4 kinds of luminance contrast (0.7, 2.2, 50.0, 180.0 lm). The fMRI data were collected on GE 1.5 T Signa Horizon LX MRI system and analyzed by AFNI to generate the activation map. Results: Responding to all 4 kinds of stimulus luminance contrast, all deaf and normal subjects showed significant activations in occipital visual cortex. For both deaf and normal subjects, the number of activated pixels increased significantly with increasing luminance contrast (F normal = 4.27, P deaf = 6.41, P 0.05). The local mean activation level for all activated pixels remained constant with increasing luminance contrast. However, there was an increase in the mean activation level for those activated pixels common to all trials as the stimulus luminance contrast was increased, but no significant difference was found within them (F normal = 0.79, P > 0.05; F deaf = 1.6, P > 0.05). Conclusion: The effect of luminance contrast on occipital visual cortex of deaf is similar to but somewhat higher than that of normal hearing subjects. In addition, it also proved that fMRI is a feasible method in the study of the deaf visual cortex
20. Dynamic regulation of gastric surface pH by luminal pH
OpenAIRE
Chu, Shaoyou; Tanaka, Shin; Kaunitz, Jonathan D.; Montrose, Marshall H.
1999-01-01
In vivo confocal imaging of the mucosal surface of rat stomach was used to measure pH noninvasively under the mucus gel layer while simultaneously imaging mucus gel thickness and tissue architecture. When tissue was superfused at pH 3, the 25 μm adjacent to the epithelial surface was relatively alkaline (pH 4.1 ± 0.1), and surface alkalinity was enhanced by topical dimethyl prostaglandin E2 (pH 4.8 ± 0.2). Luminal pH was changed from pH 3 to pH 5 to mimic the fasted-to-fed transition in intra...
1. Two extremely luminous WN stars in the Galactic center with circumstellar emission from dust and gas
OpenAIRE
Barniske, A.; Oskinova, L. M.; Hamann, W. -R.
2008-01-01
We study relatively isolated massive WN-type stars in the Galactic center. The K-band spectra of WR102ka and WR102c are exploited to infer the stellar parameters and to compute synthetic stellar spectra using the Potsdam Wolf-Rayet (PoWR) model atmosphere code. These models are combined with dust-shell models for analyzing the Spitzer IRS spectra of these objects. Archival IR images complement the interpretation. We report that WR102ka and WR102c are among the most luminous stars in the Milky...
2. Parameters of the luminous region surrounding deuterium pellets in the PLT tokamak
International Nuclear Information System (INIS)
McNeill, D.H.; Greene, G.J.; Schuresko, D.D.
1985-08-01
The luminous region of the plasma cloud surrounding deuterium pellets injected into a tokamak is studied spectroscopically. At the time of peak luminosity the average electron density is 2.4 x 10 17 cm -3 to within 30% and the temperature is at most 2.0 eV. The intensity ratio of the Balmer alpha and beta light from the pellets, the total number of emitted photons, and the apparent size of the radiating region are consistent with local thermodynamic equilibrium at this temperature and density
3. Study of luminous phenomena observed on contaminated metallic surfaces submitted to high RF fields
International Nuclear Information System (INIS)
Maissa, S.; Junquera, T.; Fouaidy, M.; Le Goff, A.; Bonin, B.; Luong, M.; Safa, H.; Tan, J.
1995-01-01
The RF field emission from a sample subjected to high RF fields in a copper cavity has been investigated. The study is focused on the luminous emissions occurring on the RF surface simultaneously with the electron emission. The optical apparatus attached to the cavity permits to observe the evolution of the emitters and the direct effects of the surface conditioning. Also, the parameters of the emitted radiation (intensity, glowing duration, spectral distribution) may provide additional informations on the field emission phenomena. Some results concerning samples intentionally contaminated with particles (metallic or dielectric) are presented. (K.A.)
4. Release of PYY from pig intestinal mucosa; luminal and neural regulation
DEFF Research Database (Denmark)
Sheikh, S P; Holst, J J; Orskov, C
1989-01-01
in release of PYY into the circulation. Stimulation of the splanchnic nerves did not affect the basal release of PYY. PYY-immunoreactivity extracted from ileal tissue or released to plasma or perfusate from the ileum was indistinguishable from synthetic porcine PYY by gel filtration and reverse phase HPLC...... of PYY was observed in isolated perfused pig ileum in response to luminal stimulation with glucose and vascular administration of the neuropeptide gastrin-releasing peptide (GRP). Electrical stimulation of the vagus nerve supply to the distal small intestine in intact anaesthetized pigs resulted...
5. Visual Performance on the Small Letter Contrast Test: Effects of Aging, Low Luminance and Refractive Error
Science.gov (United States)
2000-08-01
luminance performance and aviation, many aviators develop ametropias refractive error having comparable effects on during their careers. We were... statistically (0.04 logMAR, the non-aviator group. Separate investigators at p=0.01), but not clinically significant (ə/2 line different research facilities... statistically significant (0.11 ± 0.1 logCS, t=4.0, sensitivity on the SLCT decreased for the aviator pɘ.001), yet there is significant overlap group at a
6. Visual Perceptual Echo Reflects Learning of Regularities in Rapid Luminance Sequences.
Science.gov (United States)
Chang, Acer Y-C; Schwartzman, David J; VanRullen, Rufin; Kanai, Ryota; Seth, Anil K
2017-08-30
A novel neural signature of active visual processing has recently been described in the form of the "perceptual echo", in which the cross-correlation between a sequence of randomly fluctuating luminance values and occipital electrophysiological signals exhibits a long-lasting periodic (∼100 ms cycle) reverberation of the input stimulus (VanRullen and Macdonald, 2012). As yet, however, the mechanisms underlying the perceptual echo and its function remain unknown. Reasoning that natural visual signals often contain temporally predictable, though nonperiodic features, we hypothesized that the perceptual echo may reflect a periodic process associated with regularity learning. To test this hypothesis, we presented subjects with successive repetitions of a rapid nonperiodic luminance sequence, and examined the effects on the perceptual echo, finding that echo amplitude linearly increased with the number of presentations of a given luminance sequence. These data suggest that the perceptual echo reflects a neural signature of regularity learning.Furthermore, when a set of repeated sequences was followed by a sequence with inverted luminance polarities, the echo amplitude decreased to the same level evoked by a novel stimulus sequence. Crucially, when the original stimulus sequence was re-presented, the echo amplitude returned to a level consistent with the number of presentations of this sequence, indicating that the visual system retained sequence-specific information, for many seconds, even in the presence of intervening visual input. Altogether, our results reveal a previously undiscovered regularity learning mechanism within the human visual system, reflected by the perceptual echo. SIGNIFICANCE STATEMENT How the brain encodes and learns fast-changing but nonperiodic visual input remains unknown, even though such visual input characterizes natural scenes. We investigated whether the phenomenon of "perceptual echo" might index such learning. The perceptual echo is a
7. Higher Dimensional Spacetimes for Visualizing and Modeling Subluminal, Luminal and Superluminal Flight
International Nuclear Information System (INIS)
Froning, H. David; Meholic, Gregory V.
2010-01-01
This paper briefly explores higher dimensional spacetimes that extend Meholic's visualizable, fluidic views of: subluminal-luminal-superluminal flight; gravity, inertia, light quanta, and electromagnetism from 2-D to 3-D representations. Although 3-D representations have the potential to better model features of Meholic's most fundamental entities (Transluminal Energy Quantum) and of the zero-point quantum vacuum that pervades all space, the more complex 3-D representations loose some of the clarity of Meholic's 2-D representations of subluminal and superlumimal realms. So, much new work would be needed to replace Meholic's 2-D views of reality with 3-D ones.
8. Characteristics and conditions of production of transient luminous events observed over a maritime storm
DEFF Research Database (Denmark)
Soula, S.; van der Velde, O.; Palmiéri, J.
2010-01-01
On the night of 15/16 November 2007, cameras in southern France detected 30 transient luminous events (TLEs) over a storm located in the Corsican region (France). Among these TLEs, 19 were sprites, 6 were halos, and 5 were elves. For 26 of them, a positive “parent” cloud-to-ground lightning (P...... in a sequence had much lower peak currents. Several triangulated sprites were found to be shifted from their P+CG flashes by about 10 to 50 km and preferentially downstream. The observations suggest that the P+CG flashes can initiate both sprites and other CG flashes in a storm....
9. Distribution of the Luminous Bacterium Beneckea harveyi in a Semitropical Estuarine Environment
Science.gov (United States)
O'Brien, Catherine H.; Sizemore, Ronald K.
1979-01-01
Bioluminescent bacteria were found in the water column, sediment, shrimp, and gastrointestinal tract of marine fishes from the semitropical estuarine environment of the East Lagoon, Galveston Island, Tex. Populations in the water column decreased during cold weather while sedimentary populations persisted. The highest percentages of luminous organisms were isolated from the gastrointestinal tract of marine fishes, where they persisted during 5 days of starvation. The presence of chitin temporarily increased intestinal populations. All isolates were Beneckea harveyi, whose natural habitat appears to be the gut of fishes and whose free-living reservoir appears to be marine sediments. PMID:16345465
10. Blue green component and integrated urban design
Directory of Open Access Journals (Sweden)
Stanković Srđan M.
2016-01-01
Full Text Available This paper aims to demonstrate the hidden potential of blue green components, in a synergetic network, not as separate systems, like used in past. The innovative methodology of the project Blue Green Dream is presented through examples of good practice. A new approach in the project initiate thoughtful planning and remodeling of the settlement for the modern man. Professional and scientific public is looking for way to create more healthy and stimulating place for living. However, offered integrative solutions still remain out of urban and architectural practice. Tested technologies in current projects confirmed measurability of innovative approaches and lessons learned. Scientific and professional contributions are summarized in master's and doctoral theses that have been completed or are in process of writing.
11. BD+43° 3654 - a blue straggler?
Science.gov (United States)
Gvaramadze, V. V.; Bomans, D. J.
2008-07-01
The astrometric data on the runaway star BD+43° 3654 are consistent with the origin of this O4If star in the center of the Cyg OB2 association, while BD+43° 3654 is younger than the association. To reconcile this discrepancy, we suggest that BD+43° 3654 is a blue straggler formed via a close encounter between two tight massive binaries in the core of Cyg OB2. A possible implication of this suggestion is that the very massive (and therefore apparently very young) stars in Cyg OB2 could be blue stragglers as well. We also suggest that the binary-binary encounter producing BD+43° 3654 might be responsible for ejection of two high-velocity stars (the stripped helium cores of massive stars) - the progenitors of the pulsars B2020+28 and B2021+51.
12. Measuring Blue Space Visibility and 'Blue Recreation' in the Everyday Lives of Children in a Capital City.
Science.gov (United States)
Pearson, Amber L; Bottomley, Ross; Chambers, Tim; Thornton, Lukar; Stanley, James; Smith, Moira; Barr, Michelle; Signal, Louise
2017-05-26
Blue spaces (water bodies) may promote positive mental and physical health through opportunities for relaxation, recreation, and social connections. However, we know little about the nature and extent of everyday exposure to blue spaces, particularly in settings outside the home or among children, nor whether exposure varies by individual or household characteristics. Wearable cameras offer a novel, reliable method for blue space exposure measurement. In this study, we used images from cameras worn over two days by 166 children in Wellington, New Zealand, and conducted content and blue space quantification analysis on each image ( n = 749,389). Blue space was identified in 24,721 images (3.6%), with a total of 23 blue recreation events. Visual exposure and participation in blue recreation did not differ by ethnicity, weight status, household deprivation, or residential proximity to the coastline. Significant differences in both visual exposure to blue space and participation in blue recreation were observed, whereby children from the most deprived schools had significantly higher rates of blue space exposure than children from low deprivation schools. Schools may be important settings to promote equitable blue space exposures. Childhood exposures to blue space may not follow the expected income inequality trends observed among adults.
13. 76 FR 22923 - Wellpoint, Inc. D/B/A/Anthem Blue Cross & Blue Shield Enterprise Provider Data Management Team...
Science.gov (United States)
2011-04-25
.../B/A/Anthem Blue Cross & Blue Shield Enterprise Provider Data Management Team Including On-Site... & Blue Shield, Enterprise Provider Data Management Team, Including On-Site Leased Workers From Kelly... Of Kentucky, Enterprise Provider Data Management Team, Louisville, Kentucky TA-W-74,895B Wellpoint...
14. Radiolysis of methylene blue studied by ESR
International Nuclear Information System (INIS)
Contineau, M.; Iliescu, C.; Ciureanu, M.
1983-01-01
Electron spin resonance spectra have been used to gain information on the mechanism of radiolysis of aqueous solutions of methylene blue. The identity and behaviour of the semiquinone radicals formed as intermediate reduction products were discussed for strongly acid and for alcaline solutions. In order to obtain information on the radiolytic mechanism in strongly acidic media, irradiation was performed in the presence of various types of scavengers: sodium formate, glucose, succinic acid, hydroquinone and D,L-α alanine. (author)
15. Cognitive Variability
Science.gov (United States)
Siegler, Robert S.
2007-01-01
Children's thinking is highly variable at every level of analysis, from neural and associative levels to the level of strategies, theories, and other aspects of high-level cognition. This variability exists within people as well as between them; individual children often rely on different strategies or representations on closely related problems…
16. FROM CIRCULAR ECONOMY TO BLUE ECONOMY
Directory of Open Access Journals (Sweden)
Iustin-Emanuel, ALEXANDRU
2014-11-01
Full Text Available Addressing the subject of this essay is based on the background ideas generated by a new branch of science - Biomimicry. According to European Commissioner for the Environment, "Nature is the perfect model of circular economy". Therefore, by imitating nature, we are witnessing a process of cycle redesign: production-consumption-recycling. The authors present some reflections on the European Commission's decision to adopt after July 1, 2014 new measures concerning the development of more circular economies. Starting from the principles of Ecolonomy, which is based on the whole living paradigm, this paper argues for the development within each economy of entrepreneurial policies related to the Blue economy. In its turn, Blue economy is based on scientific analyses that identify the best solutions in a business. Thus, formation of social capital will lead to healthier and cheaper products, which will stimulate entrepreneurship. Blue economy is another way of thinking economic practice and is a new model of business design. It is a healthy, sustainable business, designed for people. In fact, it is the core of the whole living paradigm through which, towards 2020, circular economy will grow more and more.
17. 'Blue Whale Challenge': A Game or Crime?
Science.gov (United States)
Mukhra, Richa; Baryah, Neha; Krishan, Kewal; Kanchan, Tanuj
2017-11-11
A bewildering range of games are emerging every other day with newer elements of fun and entertainment to woo youngsters. Games are meant to reduce stress and enhance the cognitive development of children as well as adults. Teenagers are always curious to indulge in newer games; and e-gaming is one such platform providing an easy access and quicker means of entertainment. The particular game challenge which has taken the world by storm is the dangerous "Blue Whale Challenge" often involving vulnerable teenagers. The Blue Whale Challenge is neither an application nor internet based game but the users get a link through social media chat groups to enter this "deadly" challenge game. This probably is the only game where the participant has to end his/her life to complete the game. The innocent teenagers are being targeted based on their depressed psychology and are coercively isolated from their social milieux on the pretext of keeping the challenges confidential. To add to the woes, no option is offered to quit the challenge even if the contender is unable to complete the challenge. Blue Whale Challenge in its sheer form could be seen as an illegal, unethical and inhumane endeavor in our present society. The present communication discusses the severe effects of the game on teenagers, the ethical concerns involved and the preventive measures necessary to curb it.
18. Synchrotron powder diffraction on Aztec blue pigments
Energy Technology Data Exchange (ETDEWEB)
Sanchez del Rio, M. [European Synchrotron Radiation Facility, B.P. 220, Grenoble Cedex (France); Gutierrez-Leon, A.; Castro, G.R.; Rubio-Zuazo, J. [Spanish CRG Beamline at the European Synchrotron Radiation Facility, SpLine, B.P. 220, Grenoble Cedex (France); Solis, C. [Universidad Nacional Autonoma de Mexico, Instituto de Fisica, Mexico, D.F. (Mexico); Sanchez-Hernandez, R. [INAH Subdireccion de Laboratorios y Apoyo Academico, Mexico, D.F. (Mexico); Robles-Camacho, J. [INAH Centro Regional Michoacan, Morelia, Michoacan (Mexico); Rojas-Gaytan, J. [INAH Direccion de Salvamento Arqueologico, Naucalpan de Juarez (Mexico)
2008-01-15
Some samples of raw blue pigments coming from an archaeological rescue mission in downtown Mexico City have been characterized using different techniques. The samples, some recovered as a part of a ritual offering, could be assigned to the late Aztec period (XVth century). The striking characteristic of these samples is that they seem to be raw pigments prior to any use in artworks, and it was possible to collect a few {mu}g of pigment after manual grain selection under a microscopy monitoring. All pigments are made of indigo, an organic colorant locally known as anil or xiuhquilitl. The colorant is always found in combination with an inorganic matrix, studied by powder diffraction. In one case the mineral base is palygorskite, a rare clay mineral featuring micro-channels in its structure, well known as the main ingredient of the Maya blue pigment. However, other samples present the minerals sepiolite (a clay mineral of the palygorskite family) and calcite. Another sample contains barite, a mineral never reported in prehispanic paints. We present the results of characterization using high resolution powder diffraction recorded at the European Synchrotron Radiation Facility (BM25A, SpLine beamline) complemented with other techniques. All of them gave consistent results on the composition. A chemical test on resistance to acids was done, showing a high resistance for the palygorskite and eventually sepiolite compounds, in good agreement with the excellent resistance of the Maya blue. (orig.)
19. Synchrotron powder diffraction on Aztec blue pigments
Science.gov (United States)
Sánchez Del Río, M.; Gutiérrez-León, A.; Castro, G. R.; Rubio-Zuazo, J.; Solís, C.; Sánchez-Hernández, R.; Robles-Camacho, J.; Rojas-Gaytán, J.
2008-01-01
Some samples of raw blue pigments coming from an archaeological rescue mission in downtown Mexico City have been characterized using different techniques. The samples, some recovered as a part of a ritual offering, could be assigned to the late Aztec period (XVth century). The striking characteristic of these samples is that they seem to be raw pigments prior to any use in artworks, and it was possible to collect a few μg of pigment after manual grain selection under a microscopy monitoring. All pigments are made of indigo, an organic colorant locally known as añil or xiuhquilitl. The colorant is always found in combination with an inorganic matrix, studied by powder diffraction. In one case the mineral base is palygorskite, a rare clay mineral featuring micro-channels in its structure, well known as the main ingredient of the Maya blue pigment. However, other samples present the minerals sepiolite (a clay mineral of the palygorskite family) and calcite. Another sample contains barite, a mineral never reported in prehispanic paints. We present the results of characterization using high resolution powder diffraction recorded at the European Synchrotron Radiation Facility (BM25A, SpLine beamline) complemented with other techniques. All of them gave consistent results on the composition. A chemical test on resistance to acids was done, showing a high resistance for the palygorskite and eventually sepiolite compounds, in good agreement with the excellent resistance of the Maya blue.
20. GROWTH PERFORMANCE AND MEAT QUALITY OF DOMESTICATED BLUE SWIMMING CRAB (Portunus pelagicus)
OpenAIRE
Fujaya, Yushinta; Trijuno, Dody Dharmawan; Aslamyah, Siti; Alam, Nur
2015-01-01
Blue Swimming Crab (Portunus pelagicus) is one of the commercial crabs traded widely around the world. But, crab aquaculture has not made a significant contribution in meeting the increasing overseas market demand. Some constraints in crab cultivation were high mortality, low and variable growth rate, and low of meat quality. The aims of this research were to produce a superior broodstock through domestication and selective breeding. Superior broodstock was expected to produce a high qual... | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.6606060862541199, "perplexity": 8181.2983542454895}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 5, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-25/segments/1623487658814.62/warc/CC-MAIN-20210620054240-20210620084240-00447.warc.gz"} |
https://www.originlab.com/doc/Quick-Help/Two-Points-Slope | # 3.102 FAQ-633 How to draw a line between two points to find the slope and y-intercept values?
Last Update: 2/4/2015
This LabTalk script allows the user to graphically select two data points. Once these two points are chosen, a line will be drawn between them and the slope and y-intercept values will be displayed as a text label on the graph.
def EndToolbox {
%A=getpts.xdata$; %B=getpts.data$;
slope=(%B(%A[2])-%B(%A[1]))/(%A[2]-%A[1]);
yintercept=%B(%A[2])-slope*%A[2];
%Z="slope=$(slope) yintercept=$(yintercept)";
label -p 10 0 -s -sa -n Ltext %Z;
Ltext.background=1;
xb1=%A[1];xb2=%A[2];yb1=%B(%A[1]);yb2=%B(%A[2]);
draw -n Lline -l {xb1,yb1,xb2,yb2};
Lline.color=2; //set color to red
delete -v xb1;delete -v xb2;delete -v yb1;delete -v yb2;
delete -v slope;delete -v yintercept;
doc -uw; //window refresh
}
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Keywords:LabTalk, Linear Curve Fit | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.16156765818595886, "perplexity": 3503.525571571031}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-45/segments/1603107905965.68/warc/CC-MAIN-20201029214439-20201030004439-00461.warc.gz"} |
https://zbmath.org/?q=an:0305.65064 | ×
# zbMATH — the first resource for mathematics
Rate of convergence estimates for nonselfadjoint eigenvalue approximations. (English) Zbl 0305.65064
##### MSC:
65N15 Error bounds for boundary value problems involving PDEs 35P15 Estimates of eigenvalues in context of PDEs 65N25 Numerical methods for eigenvalue problems for boundary value problems involving PDEs 65N30 Finite element, Rayleigh-Ritz and Galerkin methods for boundary value problems involving PDEs
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https://swimswam.com/developers-propose-76-million-overhaul-to-swimming-hof/ | # Developers Propose $76 million overhaul to Swimming HOF Braden Keith ##### by Braden Keith 0 May 24th, 2010 The City of Ft. Lauterdale, Florida, home to the International Swimming Hall-Of-Fame, has sought out bids for a massive rebuild of one of its landmark facilities. The HOF, which has seen better days since it’s opening in 1964, is badly in need of a face-lift and is currently costing local tax-payers$1 million a year to keep it’s doors open.
President of the HOF Bruce Wigo envisions a HOF that rivals Sydney’s famed opera house in terms of iconic design and would provide entertainment opportunities for the general public, yet would still be one of the, if not the, premier competitive aquatics facilities in the world.
The lone proposal, made by Recreational Design & Construction, would feature a 3-story building housing a new Hall-of-Fame, restaurants, and shops, that would be part of a larger ocean-front revitalization plan.
The complexes aquatics facilities would include a full-competition diving tower, overlooking a 25-meter pool, and two full-sized 50-meter pools. The 25 meter pool would be designed with 1,500 seats and would be ideal for hosting diving, synchronised swimming, and water polo competitions. Under this proposal, the tower would have water-slides twisting around it in order to allow for a dual purpose as a water-park atmosphere. One of the 50-meter pools would feature a moving bottom, cabanas, and decorative landscaping so that it could be adjusted during the day for a resort-like atmosphere. The complex would also feature a band-shell for hosting concerts and other live performances.
Perhaps the coolest feature of the facility would be a multi-million dollar wave machine, that would be capable of producing artificial curling waves of up to 10 feet high, and water speeds of 30 miles per hour. This would be located in a padded pool and would give both novice and experienced surfers a chance to show off their skills.
Developers project that in it’s first year, this complex would bring $537,000 in revenue to the city in it’s first year of operation, based on an increase of 600,000 visitors to the center. Out of the$76 million, $19.9 million would be financed by the development company. This amount would account for the Wave House, and the private restaurants and shops. Another$9.9 million dollars for a 300-space parking garage would be financed through parking fees. The remaining \$46.2 million dollars would be financed by the Ft. Lauterdale area tax payers.
Aerial View of the International Swimming Hall of Fame in Ft. Lauterdale
Wigo was surprised that there was only one bid made for the project, however many developers bowed out because of the hyper-speciffic criteria for the project. Wigo’s comments also seem to indicate that he was underwhelmed by the architecture of the complex, and was seeking a plan that would put less of a load on the taxpayers. He described the proposal, while commendable for meeting many of the important criteria, as simply a modern update to the original design, rather than the internationally recognizable icon that he is hoping would put the facility on the map.
Many self-proclaimed “beach activists” were similarly upset by the amount of the bill that the taxpayer would have to foot, and were upset that they were not consulted in the design of a project that would have a major impact on what they see as their domain. Many other local citizens question the viability of such a huge project on a facility that has not proven to be anywhere near economic viability in it’s current state.
The piece of land that the ISHOF sits on has unique potential, as it has it’s own peninsula jutting into Florida’s Intracoastal water way. This redesign is expected to connect from the Intracoastal to the Atlantic Ocean over Seabreeze Boulevard. Hopefully, a plan can be completed that is both economically viable and visually spectacular to give this wonderful organization an even bigger footprint in the world of swimming.
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https://www.physicsforums.com/threads/problem-about-finding-the-work-done-by-friction-force.530870/ | # Problem about finding the work done by friction force
1. Sep 16, 2011
### sample5
1. The problem statement, all variables and given/known data
A block of mass M=3.4 kg is dragged over a horizontal surface by a force F=20.0 N. The block is displaced a distance d=17.0 m, the friction force Ff is 3.3 N. What is the work done by the friction force?
2. Relevant equations
Ff=μkFn
3. The attempt at a solution
I solved a problem before this one in finding the applied force but this one is very confusing to me. I have no idea where to even start. Thank you!
2. Sep 16, 2011
### himanshu07
Work done by friction is always negative. The work done by a constant force is always the dot product of the force multiplied the displacement whether or not the force is the cause of the displacement. So the work done would be -3.3*17 = -56.1 Joules.
3. Sep 16, 2011
### danielakkerma
Why don't we start with recalling how to calculate the work done by any Force?
$\Large W = \int \vec{F} \cdot d\vec{r}$
We can reduce this to simply:
$\vec{F}\cdot{\vec{x}}$
Now the rest is pretty straightforward in your case.
Hope that takes care of the confusion,
Daniel
4. Sep 16, 2011
### sample5
Thank you so much!!!
Similar Discussions: Problem about finding the work done by friction force | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9619987607002258, "perplexity": 478.92865913898714}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-39/segments/1505818689615.28/warc/CC-MAIN-20170923085617-20170923105617-00563.warc.gz"} |
https://index.mirasmart.com/ISMRM2019/PDFfiles/4778.html | ### 4778
Deep transform networks for scalable learning of MR reconstruction
Anatole Moreau1,2, Florent Gbelidji1,3, Boris Mailhe1, Simon Arberet1, Xiao Chen1, Marcel Dominik Nickel4, Berthold Kiefer4, and Mariappan Nadar1
1Digital Services, Digital Technology & Innovation, Siemens Medical Solutions, Princeton, NJ, United States, 2EPITA, Le Kremlin-Bicêtre, France, 3CentraleSupélec, Gif-sur-Yvette, France, 4Siemens Healthcare, Application Development, Erlangen, Germany
### Synopsis
In this work we introduce RadixNet, a fast, scalable, transform network architecture based on the Cooley-Tukey FFT, and use it in a fully-learnt iterative reconstruction with a residual dense U-Net image regularization. Results show that fast transform networks can be trained at 256x256 dimensions and outperform the FFT.
### Purpose
The goal of this research is to propose a low-complexity approach to fully-learnt MR reconstruction. Many methods proposed so far have been inspired by iterative reconstruction algorithms [1], [2]. These methods learn image regularizers and convergence parameters of the iterative algorithm, but data consistency is still enforced using hand-crafted forward and adjoint measurement operators. More recently, a direct fully learnt reconstruction method was proposed [3], but replacing the FFT with fully-connected layers has a significant impact on computational complexity. In this work we introduce RadixNet, a fast, scalable, transform network architecture based on the Cooley-Tukey FFT, and use it in a fully-learnt iterative reconstruction with a U-Net image regularization.
### Method
A reconstruction network was trained to reconstruct 2D MR images from under-sampled k-space data. The network structure was chosen to mimic 10 iterations of a proximal gradient algorithm. At each iteration, the network performs a gradient descent step followed by a regularization step, as described by the equation $X_n \leftarrow R_n (X_{n-1} +\alpha_n F_n^h(Y-\Pi F_n X_{n-1}))$ with $X_n$ the image reconstructed at nth iteration, $Y$ the under-sampled k-space measurements, $\Pi$ the fixed under-sampling operator, $F_n$ and $F_n^H$ the forward and adjoint measurement operators, $\alpha_n$ the trainable gradient step size and $R_n$ the regularizer. Regularizer networks were implemented using residual dense U-Nets with 2 scales, 8 channels in the hidden layers and depth 1 at each scale.
The operators $F_n$ and $F_n^h$ were also trained. In order to enable training while maintaining the low complexity of the FFT, a new network architecture named RadixNet is introduced (see Fig.1.) RadixNet is a recursive complex-valued transform network composed of 4 blocks reproducing the structure of the Cooley-Tukey FFT algorithm: a convolution to split the input into even and odd channels, recursive calls to another RadixNet on each decimated channel, a diagonal operator to apply twiddle factors and a final convolution to perform the butterfly. Each block can be made deeper and nonlinear. The overall complexity remains in $O(N \log N)$ as long as the split layer does not expand the total data size. RadixNet can be extended to multidimensional operators by splitting the input along all dimensions simultaneously (e.g. (2, 2) stride and 4 output channels in 2D).
Two networks were trained to reconstruct 2D axial T1w brain images from the Human Connectome Project [4]. 900 subjects were used with an 850 training / 50 validation split and 64 slices per subject for a total of 57600 images of fixed dimensions 256x256. A fixed variable density sampling pattern with 5x acceleration and front-to-back readout direction was used to generate the input k-space. One network was trained with 2D forward and adjoint FFTs as operators, the other with shallow linear 2D-RadixNets initialized with the Cooley-Tukey coefficients. The weights of the U-Net were initialized to i.i.d. Gaussian values with 0 mean and standard deviation 1e-3. Training used an $L_2$ loss and the Adam algorithm with mini-batch size 16 and learning rate 1e-4.
### Results
After training, the RadixNet based reconstruction network outperformed the FFT by 1.2 dB in validation PSNR (36.6dB vs 35.4dB). PSNR evolution during training is shown in Fig. 3. Fig. 2 shows a validation example with the ground truth, zero-filled image and network outputs.
### Discussion
These early empirical results show that fast transform networks can be trained at 256x256 dimensions and outperform the FFT. This could pave the way to future high-dimension applications. Deeper RadixNet could also enable the reconstruction to correct for forward imaging model imperfections such as trajectory errors or patient motion etc. Future works will include incorporating parallel imaging and scaling up to 3D.
### Disclaimer
The concepts and information presented in this paper are based on research results that are not commercially available.
### Acknowledgements
No acknowledgement found.
### References
[1] Hammernik, Kerstin, Teresa Klatzer, Erich Kobler, Michael P. Recht, Daniel K. Sodickson, Thomas Pock, and Florian Knoll. "Learning a variational network for reconstruction of accelerated MRI data." Magnetic resonance in medicine 79, no. 6 (2018): 3055-3071.
[2] Mardani, Morteza, Enhao Gong, Joseph Y. Cheng, Shreyas S. Vasanawala, Greg Zaharchuk, Lei Xing, and John M. Pauly. "Deep Generative Adversarial Neural Networks for Compressive Sensing (GANCS) MRI." IEEE transactions on medical imaging (2018).
[3] Zhu, Bo, Jeremiah Z. Liu, Stephen F. Cauley, Bruce R. Rosen, and Matthew S. Rosen. "Image reconstruction by domain-transform manifold learning." Nature 555, no. 7697 (2018): 487.
[4] Van Essen, David C., Stephen M. Smith, Deanna M. Barch, Timothy EJ Behrens, Essa Yacoub, Kamil Ugurbil, and Wu-Minn HCP Consortium. "The WU-Minn human connectome project: an overview." Neuroimage 80 (2013): 62-79. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.587368369102478, "perplexity": 3883.110788448819}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-21/segments/1652663016853.88/warc/CC-MAIN-20220528123744-20220528153744-00480.warc.gz"} |
https://www.physicsforums.com/threads/quick-question-about-eigenvectors.362188/ | 1. Dec 10, 2009
### sjeddie
Is at least one eigenvector guaranteed to exist given that we have found at least one eigenvalue? So, for example, given that we have found an eigenvalue of multiplicity 2 of a matrix, are we guaranteed to find at least 1 eigenvector of that matrix? Why or why not?
2. Dec 10, 2009
### rochfor1
3. Dec 11, 2009
### sjeddie
Thanks.
So it is possible to have less eigenvectors than eigenvalues (according to wiki's explanation on geometric multiplicity), so is it possible to have no eigenvectors at all for some eigenvalues?
4. Dec 11, 2009
### rochfor1
Not quite. Every eigenvalue will have at least one eigenvector. It is possible, however, for a repeated eigenvalue to have less linearly independent eigenvectors (its geometric multiplicity) than the number of repetitions of that eigenvalue (its algebraic multiplicity). There will always be at least one eigenvector though.
5. Dec 11, 2009
### sjeddie
thank you very much rochfor1!
6. Dec 12, 2009
### HallsofIvy
The definition of "eigenvalue" is "$\lambda$ is an eigenvalue for linear operator A if and only if there exist a non-zero vector, v, such that $Av= \lambda v$".
Such a vector is, of course, an eigenvector so, by definition, there exist at least one eigenvector corresponding to any eigenvalue. And, in fact, any multiple of an eigenvector or any linear combination of eigevectors corresponding to the same eigenvalue is also an eigenvector- there necessarily exist an infinite number of eigenvectors corresponding to any eigenvalue- they form a subspace.
Rochfor1 is specifically talking about the number of independent eigenvectors corresponding to each eigenvalue- the dimension of that subspace. That's the "geometric multiplicity" of that eigenvalue. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.984584629535675, "perplexity": 467.413106044965}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-04/segments/1547584328678.85/warc/CC-MAIN-20190123085337-20190123111337-00090.warc.gz"} |
http://www.ck12.org/book/Basic-Algebra/r1/section/11.3/ | <meta http-equiv="refresh" content="1; url=/nojavascript/"> Radical Equations | CK-12 Foundation
You are reading an older version of this FlexBook® textbook: CK-12 Algebra - Basic Go to the latest version.
Created by: CK-12
Solving radical equations is no different from solving linear or quadratic equations. Before you can begin to solve a radical equation, you must know how to cancel the radical. To do that, you must know its inverse.
Original Operation Inverse Operation
Cube Root Cubing (to the third power)
Square Root Squaring (to the second power)
Fourth Root Fourth power
$n$th” Root $n$th” power
To solve a radical equation, you apply the solving equation steps you learned in previous chapters, including the inverse operations for roots.
Example 1: Solve $\sqrt{2x-1}=5$.
Solution: The first operation that must be removed is the square root. Square both sides.
$\left ( \sqrt{2x-1} \right )^2&=5^2\\2x-1&=25\\2x&=26\\x&=13$
Remember to check your answer by substituting it into the original problem to see if it makes sense.
Example: Solve $\sqrt{x+15}=\sqrt{3x-3}$.
Solution: Begin by canceling the square roots by squaring both sides.
$\left ( \sqrt{x+15} \right )^2&=\left ( \sqrt{3x-3} \right )^2\\x+15&=3x-3\\\text{Isolate the} \ x-\text{variable}: \qquad \qquad 18 & = 2x\\x&=9$
Check the solution: $\sqrt{9+15}=\sqrt{3(9)-3} \rightarrow \sqrt{24}=\sqrt{24}$. The solution checks.
Extraneous Solutions
Not every solution of a radical equation will check in the original problem. This is called an extraneous solution. This means you can find a solution using algebra, but it will not work when checked. This is because of the rule in Lesson 11.2.
Even roots of negative numbers are undefined.
Example: Solve $\sqrt{x-3}-\sqrt{x}=1$.
Solution:
$\text{Isolate one of the radical expressions}. \qquad \ \sqrt{x-3}&=\sqrt{x}+1\\\text{Square both sides}. \quad \left ( \sqrt{x-3} \right )^2 & = \left ( \sqrt{x}+1 \right )^2\\\text{Remove parentheses}. \qquad \quad \ x-3&=\left ( \sqrt{x} \right )^2 + 2\sqrt{x}+1\\\text{Simplify}. \qquad \quad \ x-3&=x+2\sqrt{x}+1\\\text{Now isolate the remaining radical}. \qquad \qquad -4&=2\sqrt{x}\\\text{Divide all terms by} \ 2. \qquad \qquad -2 &= \sqrt{x}\\\text{Square both sides}. \qquad \qquad \quad \ x&=4$
Check: $\sqrt{4-3} - \sqrt{4} = \sqrt{1}-2=1-2=-1$. The solution does not check out. The equation has no real solutions. Therefore, $x=4$ is an extraneous solution.
Example: A sphere has a volume of $456 \ cm^3$. If the radius of the sphere is increased by 2 cm, what is the new volume of the sphere?
Solution:
1. Define variables. Let $R=$ the radius of the sphere.
2. Find an equation. The volume of a sphere is given by the formula: $V=\frac{4}{3}\pi r^3$.
By substituting 456 for the volume variable, the equation becomes $456=\frac{4}{3} \pi r^3$
$\text{Multiply by} \ 3. \qquad \quad 1368 &= 4\pi r^3\\\text{Divide by} \ 4\pi. \qquad 108.92&=r^3\\\text{Take the cube root of each side.} \qquad \qquad \ r&=\sqrt[3]{108.92} \Rightarrow r = 4.776 \ cm\\\text{The new radius is 2 centimeters more.} \qquad \qquad \ r &= 6.776 \ cm\\\text{The new volume is}: \qquad \qquad V &= \frac{4}{3}\pi (6.776)^3 = 1302.5 \ cm^3$
Check by substituting the values of the radii into the volume formula.
$V=\frac{4}{3}\pi r^3=\frac{4}{3}\pi (4.776)^3=456 \ cm^3$. The solution checks out.
Practice Set
Sample explanations for some of the practice exercises below are available by viewing the following videos. Note that there is not always a match between the number of the practice exercise in the videos and the number of the practice exercise listed in the following exercise set. However, the practice exercise is the same in both.
In 1-16, find the solution to each of the following radical equations. Identify extraneous solutions.
1. $\sqrt{x+2}-2=0$
2. $\sqrt{3x-1}=5$
3. $2\sqrt{4-3x}+3=0$
4. $\sqrt[3]{x-3}=1$
5. $\sqrt[4]{x^2-9}=2$
6. $\sqrt[3]{-2-5x}+3=0$
7. $\sqrt{x}=x-6$
8. $\sqrt{x^2-5x}-6=0$
9. $\sqrt{(x+1)(x-3)}=x$
10. $\sqrt{x+6}=x+4$
11. $\sqrt{x}=\sqrt{x-9}+1$
12. $\sqrt{3x+4}=-6$
13. $\sqrt{10-5x}+\sqrt{1-x}=7$
14. $\sqrt{2x-2}-2\sqrt{x}+2=0$
15. $\sqrt{2x+5}-3\sqrt{2x-3}=\sqrt{2-x}$
16. $3\sqrt{x}-9=\sqrt{2x-14}$
17. The area of a triangle is $24 \ in^2$ and the height of the triangle is twice as long and the base. What are the base and the height of the triangle?
18. The volume of a square pyramid is given by the formula $V=\frac{A(h)}{3}$, where $A=$ area of the base and $h=$ height of the pyramid. The volume of a square pyramid is 1,600 cubic meters. If its height is 10 meters, find the area of its base.
19. The volume of a cylinder is $245 \ cm^3$ and the height of the cylinder is one-third the diameter of the cylinder's base. The diameter of the cylinder is kept the same, but the height of the cylinder is increased by two centimeters. What is the volume of the new cylinder? $(\text{Volume} = \pi r^2 \cdot h)$
20. The height of a golf ball as it travels through the air is given by the equation $h=-16t^2+256$. Find the time when the ball is at a height of 120 feet.
Mixed Review
1. Joy sells two types of yarn: wool and synthetic. Wool is $12 per skein and synthetic is$9 per skein. If Joy sold 16 skeins of synthetic and collected a total of 432, how many skeins of wool did she sell?
2. Solve $16 \ge |x-4|$.
3. Graph the solution $\begin{cases}y \le 2x-4\\y>-\frac{1}{4} x+6\end{cases}$.
4. You randomly point to a day in the month of February 2011. What is the probability your finger lands on a Monday?
5. Carbon-14 has a half life of 5,730 years. Your dog dug a bone from your yard. It had 93% carbon-14 remaining. How old is the bone?
6. What is true about solutions to inconsistent systems?
8 , 9
Feb 22, 2012
Dec 11, 2014 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 42, "texerror": 0, "math_score": 0.8759975433349609, "perplexity": 522.8309488469489}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-52/segments/1418802770371.28/warc/CC-MAIN-20141217075250-00084-ip-10-231-17-201.ec2.internal.warc.gz"} |
https://www.physicsforums.com/threads/pd-across-the-terminals-of-two-cells.888245/ | # Homework Help: PD across the terminals of two cells
1. Oct 7, 2016
### moenste
1. The problem statement, all variables and given/known data
In the following circuit, cell A has an EMF of 10 V and an internal resistance of 2 Ω; cell B has an EMF of 3 V and an internal resistance of 3 Ω.
(a) Show that the currents through A and B are 65 / 71 amps and 14 / 71 amps respectively. What is the magnitude of the current through GF?
(b) Determine the power dissipated as heat in the resistor FE. If the circuit is switched on for 30 minutes, calculate the energy dissipated in FE in kilowatt-hours.
(c) What is the potential difference (i) across the terminals of cell A, (ii) across the terminals of cell B?
(d) Calculate the rate at which energy is being supplied (or absorbed) by cells A and B.
(e) If the contact F can be moved along the resistor GE, find the value of the resistance GF when no current is flowing through cell B.
(f) At what setting of F would cell B (i) be discharging at the maximum possible rate and (ii) be charging at the maximum possible rate?
Answers: (a) 0.718 A, (b) 4.19 W, 2.095 * 10-3 kWh, (c) 8.17 V, 3.59 V, (d) 9.15 W, 0.592 W, (e) 3.60 Ω.
2. The attempt at a solution
(a) 10 - 5 (I1 - I3) - 5 I1 - 2 I1 = 0 → I3 = 2.4 I1 - 2. Plug into: -3 -3 I3 + 5 I1 - 5 I3 = 0 → I1 = 0.9155 A (65 / 71), I3 = 0.197 A and I2 = 0.718 A.
(b) P = V I and V = R I = 5 * (65 / 71) = 4.6 V. Then P = 4.6 * (65 / 71) = 4.19 W.
W = V I t = 4.6 * (65 / 71) * (30 * 60) = 7543 J. 1 kWh = 3.6 * 106 J so 7543 / 3.6 * 106 = 2.095 * 10-3 kWh.
(c) This is where difficulties come. As I understand, I should calculate the voltage of the circuits. (i) V = I R = (65 / 71) * (5 + 2) = 6.4 V of the 5 Ω and 2 Ω resistors around A. (ii) We calculte the voltage of the 3 Ω resistor: V = (14 / 71) * 3 = 0.59 V plus 3 V is 3.59 V for the 5 Ω resistor since it is parallel.
I didn't continue since I am not sure on (c). What's wrong with it?
2. Oct 7, 2016
### cnh1995
You are asked to find the terminal voltages of the cells, given the current, emf and internal resistance of each cell. What is the formula for terminal voltage (p.d.) of the cell then?
3. Oct 7, 2016
### moenste
Hm, PD = EMF + r?
4. Oct 7, 2016
5. Oct 7, 2016
### moenste
@cnh1995
I get the correct answer for (c) (ii): 3 + 3 * (14 / 71) = 3.59 V.
But what's wrong with (c) (i): 10 + 2 * (65 / 71) = 11.8 V?
6. Oct 7, 2016
### cnh1995
Sorry I edited my previous post. Forgot to replace + sign with -.
7. Oct 7, 2016
### moenste
Hm, in that case I get a correct answer for (i) and a wrong one for (ii) .
I did a drawing for (a) and (b) and in my drawing a have current going from A to the left and then entering B from the left and then current enters A from the right. So in terms of B we have + 3 V - ... + 3 Ω - and so we have PD = EMF + I r. And in A we have + 10 V - ... - 2 Ω + and so we PD = EMF - I r.
I think this is the correct reason...
8. Oct 7, 2016
### cnh1995
You need to consider the directions of the currents. What is the direction of the current through B? Terminal voltage of B is greater than the emf.
9. Oct 7, 2016
### cnh1995
Yes. That's the reason. Good job!
10. Oct 7, 2016
### cnh1995
This is asking you the power supplied or absorbed by each cell.
What should be the condition for zero current through cell B?
11. Oct 7, 2016
### moenste
This one I solved: P = V I → PA = 10 * (65 / 71) = 9.15 W and PB = 3 * (14 / 76) = 0.59 W.
This one I'm struggling.
I tried to find the IA: -3 + 5 (IA - IB) = 0 so IA = 0.6 A. Then plug it in 10 - 0.6 R - 5 * 0.6 - 2 * 0.6 = 0 so R = 9.6 Ω.
I also tried just to do 10 - (65 / 71) R - 5 (65 / 61) - 2 (65 / 71) = 0 so R = 3.92 Ω.
Also tried 10 - 12 IA = 0 so IA = 0.83 A. So 10 - 0.83 R - 5 * 0.83 - 2 * 0.83 = 0 so R = 5.048 Ω.
What am I missing?
12. Oct 7, 2016
### cnh1995
The condition for zero current through cell B.
What should be the voltage across GF? Or in simple words, what should be the voltage across the internal resistance of cell B? Consider only the loop containing G-F resistance and cell B. Draw this loop and see.
Last edited: Oct 7, 2016
13. Oct 8, 2016
### moenste
If no current is flowing through cell B then all current is flowing through the GF resistor. And then we have R = V / I = 3.59 V / (65 / 71) = 3.92 Ω.
14. Oct 8, 2016
### Staff: Mentor
By moving the slider on the variable resistor (also known as a potentiometer), you're changing the circuit. So the old values of current and potential differences no longer hold. You need to re-evaluate the circuit for the new conditions.
Since you're looking for conditions where cell B has zero current flowing, start by imagining that the lower cell is not connected at F (open that connection temporarily). This will let you evaluate what will be going on in the upper loop under those conditions. What then is the current in the upper loop?
15. Oct 8, 2016
### moenste
I3 = 0 so 10 - 5 (I1 - I3) - 5 I1 - 2 I1 = 0 so I1 = 0.833 A.
And then 10 - 0.83 R - 5 * 0.83 - 2 * 0.83 = 0 so R = 5 Ω.
?
16. Oct 8, 2016
### Staff: Mentor
Okay, good.
Can you spell out what the above calculation is? What are each of the terms?
17. Oct 8, 2016
### moenste
This is the same circuit but with the unknown GF resistor of 5 Ω which we need to find (the AGEA area).
But in that case we'll get the same answer...
We can't go through GBFG though. I mean GBF is zero.
18. Oct 8, 2016
### Staff: Mentor
The resistor GFE has a total resistance (from G to E) of 10 Ω. When the slider F moves, it divides the resistor into two parts, the sum of which remains 10 Ω. So for example, if F is located exactly in the middle then the two parts will be 5 Ω each. But if it's moved away from the middle they might be 2 Ω and 8 Ω, or 7.3 Ω and 2.7 Ω, or any combination that sums to 10 Ω. What you need to do is determine what combination will yield the desired condition that when cell B is connected at their junction, no current flows in the lower loop.
Hint: you should recognize that GFE along with the 10 V battery forms a potential divider.
19. Oct 8, 2016
### moenste
10 = 0.83 R1 + 0.83 R2 + 0.83 * 2
R2 = 10.048 - R1
That's as far as I can go.
Update:
-3 - 3 * 0 + 0.83 R1 = 0
R1 = 3.6 Ω
It gets the corect answer. But how can we consider it, since the whole GBF line is zero?
20. Oct 8, 2016
### Staff: Mentor
Start with the required condition that prevents current from flowing in the bottom loop. What must the potential difference be between G and F?
21. Oct 8, 2016
### moenste
We can't find the PD between G and F. We need to know the resistance to find it. We can only say that V = I R = 0.83 * 2 = 1.66 V is the PD of the internal resistor and the GE line has 10 - 1.66 = 8.34 V.
And if we put 8.34 = 0.83 R1 + 0.83 R2 we'll get the same result as in post # 19.
22. Oct 8, 2016
### Staff: Mentor
That's not true. You can specify the potential difference first, then calculate the required resistance. What potential difference will prevent current from flowing in the bottom loop?
Consider the following example where you have a known battery of 3 V with some internal resistance, and some other (unknown) potential difference source:
What must $V_x$ be to prevent current from flowing in the loop?
23. Oct 8, 2016
### moenste
I think you are suggesting this (maybe you missed it, I updated the post later):
24. Oct 8, 2016
### Staff: Mentor
It works because if the bottom loop has no current flowing then the upper loop is effectively isolated and its current is fixed solely by the resistance in its path: the internal resistance of the 10 V battery and the 10 Ohms of the potentiometer. Then you simply need to find the potential difference across R1 that makes your equation true. R1 has the upper loop's current running through it all alone, since the lower loop is contributing no current.
The situation in the example in post #22 shows what potential difference is required to prevent current flow.
25. Oct 8, 2016
### moenste
VX - Ir - 3 = 0
VX = 3 V since I = 0.
And how do we approach this one:
? | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7642545700073242, "perplexity": 1085.5957240265618}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-30/segments/1531676592875.98/warc/CC-MAIN-20180722002753-20180722022753-00119.warc.gz"} |
https://begorov.me/trpl/old_trpl/if-let.html | # if let
if let allows you to combine if and let together to reduce the overhead of certain kinds of pattern matches.
For example, let’s say we have some sort of Option<T>. We want to call a function on it if it’s Some<T>, but do nothing if it’s None. That looks like this:
# let option = Some(5);
# fn foo(x: i32) { }
match option {
Some(x) => { foo(x) },
None => {},
}
We don’t have to use match here, for example, we could use if:
# let option = Some(5);
# fn foo(x: i32) { }
if option.is_some() {
let x = option.unwrap();
foo(x);
}
Neither of these options is particularly appealing. We can use if let to do the same thing in a nicer way:
# let option = Some(5);
# fn foo(x: i32) { }
if let Some(x) = option {
foo(x);
}
If a pattern matches successfully, it binds any appropriate parts of the value to the identifiers in the pattern, then evaluates the expression. If the pattern doesn’t match, nothing happens.
If you want to do something else when the pattern does not match, you can use else:
# let option = Some(5);
# fn foo(x: i32) { }
# fn bar() { }
if let Some(x) = option {
foo(x);
} else {
bar();
}
## while let
In a similar fashion, while let can be used when you want to conditionally loop as long as a value matches a certain pattern. It turns code like this:
let mut v = vec![1, 3, 5, 7, 11];
loop {
match v.pop() {
Some(x) => println!("{}", x),
None => break,
}
}
Into code like this:
let mut v = vec![1, 3, 5, 7, 11];
while let Some(x) = v.pop() {
println!("{}", x);
} | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8641911745071411, "perplexity": 5374.403790705105}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-09/segments/1550249434065.81/warc/CC-MAIN-20190223021219-20190223043219-00063.warc.gz"} |
http://cpr-grqc.blogspot.com/2013/07/13072969-ke-yang-et-al.html | ## Linear perturbations in Eddington-inspired Born-Infeld gravity [PDF]
Ke Yang, Xiao-Long Du, Yu-Xiao Liu
We study the full linear perturbations of a homogeneous and isotropic spacetime in the Eddington-inspired Born-Infeld gravity. The stability of the perturbations are analyzed in the Eddington regime. We find that the scalar and transverse vector modes are stable, and the transverse-traceless tensor mode is unstable for positive $\kappa$. However, these modes are unstable and hence cause the instabilities for negative $\kappa$.
View original: http://arxiv.org/abs/1307.2969 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9619489908218384, "perplexity": 3408.299583490803}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-43/segments/1508187824293.62/warc/CC-MAIN-20171020173404-20171020193404-00238.warc.gz"} |
https://www.varsitytutors.com/psat_math-help/how-to-find-the-solution-to-a-rational-equation-with-lcd | # PSAT Math : How to find the solution to a rational equation with LCD
## Example Questions
–1
1
2
–2
0
2
Explanation:
b/(m+ 1)
–b/(+ 1)
bm/(m+ 1)
–bm/(m+ 1)
b/(m– 1)
b/(m+ 1)
Explanation:
### Example Question #11 : Equations / Inequalities
In the equation below, , , and are non-zero numbers. What is the value of in terms of and ? | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8309931755065918, "perplexity": 3649.550310675448}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-13/segments/1521257650685.77/warc/CC-MAIN-20180324132337-20180324152337-00731.warc.gz"} |
https://embdev.net/topic/129581 | # Forum: ARM programming with GCC/GNU tools H-JTAG with WinARM
Rate this post
0 ▲ useful ▼ not useful
Hello colleagues,
I have been able to get my board to communicate with H-JTAG and loaded a
program to check the working.
I wish to use the de-bugging facility provided with this tool with the
WinARM toolchain.
Can anyone point me to some documentation(preferable cookbookish :)) I
can use to get started?
TIA
Thomas F
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0 ▲ useful ▼ not useful
Thomas Fernando wrote:
> I have been able to get my board to communicate with H-JTAG and loaded a
> program to check the working.
> I wish to use the de-bugging facility provided with this tool with the
> WinARM toolchain.
> Can anyone point me to some documentation(preferable cookbookish :)) I
> can use to get started?
At least the last time I looked at H-JTAG the only debugger-"API" was a
RDI-interface provided by a DLL. I'm not sure if the gdb included in the
WinARM packages can talk to a "RDI-dll" as in H-JTAG, but I don't think
so. You may try the Codesourcery G++ lite package. There is a binary
included in this package, I do not recall the exact filename but it
should be something like *-sprite.exe. IRC this can be configured to use
a RDI-dll and should provide a gdb-server. Sorry, not "cookbokish" but
hopefully a hint in the right direction - I have not tested this myself.
There is some documentation in the Codesourcery package.
As an alternative take a look at OpenOCD, it offers a gdb-server and can
"talk" to Wiggler-type JTAG-interfaces.
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0 ▲ useful ▼ not useful
Hi Martin,
I assumed that since H-JTAG was bundled in utils , someone had done the
needful.
Thanks for responding.
Regards
Thomas
Martin Thomas wrote:
> Thomas Fernando wrote:
>
>> I have been able to get my board to communicate with H-JTAG and loaded a
>> program to check the working.
>> I wish to use the de-bugging facility provided with this tool with the
>> WinARM toolchain.
>> Can anyone point me to some documentation(preferable cookbookish :)) I
>> can use to get started?
>
> At least the last time I looked at H-JTAG the only debugger-"API" was a
> RDI-interface provided by a DLL. I'm not sure if the gdb included in the
> WinARM packages can talk to a "RDI-dll" as in H-JTAG, but I don't think
> so. You may try the Codesourcery G++ lite package. There is a binary
> included in this package, I do not recall the exact filename but it
> should be something like *-sprite.exe. IRC this can be configured to use
> a RDI-dll and should provide a gdb-server. Sorry, not "cookbokish" but
> hopefully a hint in the right direction - I have not tested this myself.
> There is some documentation in the Codesourcery package.
>
> As an alternative take a look at OpenOCD, it offers a gdb-server and can
> "talk" to Wiggler-type JTAG-interfaces.
Rate this post
0 ▲ useful ▼ not useful
Thomas Fernando wrote:
> Hi Martin,
>
> I assumed that since H-JTAG was bundled in utils , someone had done the
> needful.
> Thanks for responding.
Well, just because a tool is included in the WinARM package it does not
mean that it is "fully integrated". The tools just reflect my personal
taste and I have included H-JTAG because of the flash-programming
support for a lot of targets.
• $formula (LaTeX syntax)$ | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.2399844229221344, "perplexity": 6247.7630669287}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-40/segments/1600401601278.97/warc/CC-MAIN-20200928135709-20200928165709-00363.warc.gz"} |
http://physics.stackexchange.com/questions/51631/could-one-argue-that-h-planck-constant-and-hbar-2-dirac-constant-are-in-f/51637 | # Could one argue that h (Planck constant) and $\hbar$/2 (Dirac constant) are in fact independant constants?
My question is very naive and could sound strange but it seems to me natural in so far as the Planck constant is related to the first quantization (of newtonian particle mechanics/galilean relativity) while the Dirac one shows up in the second quantization (of fields theory/special relativity)... Anyway I think the conceptual difference between the two constants is rarely emphasized.
-
"First quantization" and "second quantization" are widely used names for the same procedure applied to two different classical systems – classical mechanics and classical field theory. In both cases, the operation introduces Planck's constant and it's always the same constant. For example, the angular momentum $J_z$ is a multiple of $\hbar/2=h/4\pi$ both in non-relativistic quantum mechanics for a few particles as well as quantum field theory – this fact results both from "first quantization" as well as "second quantization". It is a universal fact of quantum mechanics. In the same way, Schrödinger's equation contains the factor of $\hbar$ and this equation holds for non-relativistic quantum mechanics as well as quantum field theory (with an appropriate Hamiltonian that encodes the total energy).
The reason why $\hbar$ is more often found in quantum field theory and $h$ is more often found in simpler discussions of quantum mechanics is that $h$ is associated with frequency $f$ which is the quantity chosen by physics beginners while the advanced physicists usually consider the angular frequency $\omega=2\pi f$ to be more natural, and that's why they also talk about $\hbar$. Note that the energy of a photon (or another quantum) is $E=hf=\hbar\omega$; the factors of $2\pi$ cancel.
The constant $\hbar$ is more fundamental because it naturally appears in the Heisenberg equations, Schrödinger's equations, Feynman's path integral, commutators of $x,p$, and so on. These are the fundamental equations and it would be a waste of time to write an extra $1/2\pi$ in all of them. A physics beginner doesn't really understand these fundamental equations well. He prefers to look at things like $E=hf$ which may be written in a simple way using $h$ as long as we express the frequency by $f$.
But $\hbar=h/2\pi$ always holds – they're not independent at all. They're just two constants associated with two conventions and the more one knows about quantum theories, the more likely he is to switch to $\hbar$.
Let me also mention that the Dirac constant is $\hbar$ and not $\hbar/2$.
-
Thank you Lubos! I understand the fundamental significance of angular frequency ω in advanced physics as you explain it and I know its relevance in dimensional analysis too : I have in mind the argument to obtain (modulo a constant factor close to one) the correct electromagnetic (2/3) or gravitational (32/5) power radiated under the assumption of a dipolar (ω^4) or quadrupolar ( ω^6) emission ! Now coming back to this half integer spin or Dirac operator that is some kind of a square root of the Laplacian I can't help thinking that there is more than one mystery in quantization ... – laboussoleestmonpays Feb 26 '13 at 20:38
Nah, they're the same. Even Planck's constant comes from fields; he was looking at the electromagnetic radiation (which is all field, all the time) getting kicked off by a warm black body.
Also, while most people use $h \nu$ for the energy of a photon, in grad school (physics) we often used $\hbar \omega$. Also, usually I've seen the Dirac constant defined as $\hbar$, rather than $\frac{\hbar}{2}$. We often use the term Planck's Constant for both interchangeably (Don't worry, Dirac gets his due in physics). The first time I learned the Schroedinger Equation, it was with $\hbar$ (I now have it tattooed across my back in the same form).
-
Cheat fail: when you're in an exam and you forget the Schr. eqn, all you can do is help the person sat behind you. – twistor59 Jan 19 '13 at 16:47
Ha ha ha, I am laughing aloud! This was completely unexpected. This is the weirdest answer I have seen here. Upvoted! (+1) – Eduardo Guerras Valera Jan 20 '13 at 7:11
Thank you for your answer "thatnerd"! I know that Dirac got his due in physics but since we owe him the "discovery" or unveiling of spinors in the real physical world I regret that the Dirac constant is ℏ and not ℏ/2 ... – laboussoleestmonpays Feb 26 '13 at 19:42
The factor $\frac{1}{2\pi}$ it is a matter of convenience. Dirac constant, or Planck's reduced constant can show up and indeed it does in quantum statistical mechanics. If the inverse of $2\pi$ is going to appear a lot of times,you should use $\hbar$ instead of $h$ but, as far as I know, it has nothing to do with your proposal.
-
The fact that $h$ appears in first quantization and $\hbar$ is purely a matter of convention. Since $$\hbar = \frac{h}{2 \pi}$$ we may as well write equations like $$E = h \nu$$ as $$E = \hbar \omega$$ and in fact that is a frequent form of that equation.
Multiplication and division by a constant doesn't make the two independent of each other. The physical content is still exactly the same.
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THE
ENCYCLOPAEDIA BRITANNICA
DICTION ART
7
OF
Arts. Sciences, and General Literature
. THE R. 8. PEALE REPRINT
WITI[ NEW MAPS AND ORIGINAL AMERICAN ARTICLES BY EMINENT WRITERS
By W. H. DePUY, U.D.. LL.D.,
Bringing Each Volume LTp to Date.
VOLUME i
CHICAGO
R. S. PEALE COMPANY
1892.
708GS5
5
\). 1
Bv K. S. Pealk Company.
Encyclopaedia Britannica.
Vol I. — A-(ANA).
Total Number of Articles, 966.
PRINCIPAL CONTENTS.
ABBEY AND ABBOT. Rev. Edmund Venables, Precentor and Cauou of Lincoln.
ABEL.iRD. G. Croom Robertson, M.A., Professor of Logic, University College, London.
ABERDEEN. Alex. Cruickshank, M.A.
ABRAHAM. Rev. Samuel Davidson, D.D., Author of "Introduction to the Old and New Testaments," &c.
ABY.SSINIA. David Kav, Fellow of the Royal Geographical Society.
ACADEMY. Francis Storr, M.A., Author of "Tables of Irregular Greek Verbs."
ACCENT. John M. Ross, LL.D., late Editor of the "Globe Encyclopsedia."
ACCLIMATISATION. Alfred R. Wallace, Author of "Theory of Natural Selection."
ACHILLES. A. Stuart Murray, British Museum, London.
ACHIN. Col. Henry Yule, C.B., F.E.G.S., Author of "Tbe Book of Marco Polo."
ACOUSTICS. David Tho.mpson. M.A., late Professor of Natural Philosophy, University of Aberdeen.
ACTS OF THE APOSTLES. Principal Donaldson, LL.D., Authorof "Early Christian Literature and Doctrine."
ACTINOZOA. T. H. Hu.XLEY, LL.D.. F.R.S., Professor in the Royal School of Mines, London.
ADDISON. William Spalding, LL.D., late Professor of Rhetoric and Belles Lettres, University of Edinburgh.
ADULTERATION. Dr. HENRY Letheby, Ph.D., formerly Medical Officer of Health to the City of London.
AERONAUTICS. James Glaishek, F.R.S., Superintendent of the Meteorological Section, Greenwich
Observatory.
jESCHYL^S. J.Stuart Blackie. late Professor of Greek. University of Edinburgh.
jESIR. Miss E. C. Otte, Translator of Humboldt's "Cosmos."
jESTHETICS. Ja.mes Sully. LL.D., Author of "Sensation and Intuition."
AFGHANISTAN. CoL Y^ULB, C.B.
AFRICA. Keith Johnston, Fellow of the Royal Geographical Society.
AG.VSSIZ. W.C. Williamson, LL.D., F.R.S., Professor of Natural History, Owens College, Manchester.
AGK.\RIAN LAWS. GEORGE Ferguson. LL.D., formerly Professor of Humanity, Uuiversity of Aberdeen.
AGRICULTURE. John Wilson, Member of Council, Highland and Agricultural Society, and W. T. Thornton,
Author of "A Plea for Peasant Proprietors."
ALCHEMY. Jules Andrieu.
ALEXANDER THE GREAT. Rev. Sir George W. Cox, Baronet, Author of "A History of Greece." &o.
ALEXANDER VI. Richard Garnett, British Museum, Author of " Idylls and Epigrams from Greek
Anthology."
ALFORD. DE.A.N. Charles Kent, .\uthor of "Charles Dickens as a Reader."
ALG.E. Dr. J. HuTTON Balfour, F.R.S.. late Professor of Botany in the University of Edinburgh.
ALGEBRA. Philip Kelland, F.R.S. , late Professor of Mathematics, University of Edinburgh.
ALGEr'ia. David Kay. F.R.G.S.
ALPH.\BET. John Peile, M.A. , Fellow and Tutor of Christ's College, Cambridge.
ALPS. John Ball, F.R.S., late President of the Alpine Club.
ALTAR. Rev. G. H. Forbes.
ALUM. James Dewar, F.R.S., Jacksonian Professor of Natural Experimental Philosophy, Cambridge.
AMAZON. A. Stuart Murray, British Museum.
AMBASSADOR. HENRY Reeve, CD., D.C.L., Registrar of H.M. Privy Council.
AMBULANCE. Thomas Long.more, C.B., Professor of Army Surgery, Netley.
AMERIC*. (North and South). Charles Maclaren, late Fellow of the Geological Society, and of the Royal
Society, Edinburgh.
AMERICAN LITER.\.TURE. John Nichol, LL.D., Professor of English Language, University of Glasgow.
AMMON. Samuel Birch, LL.D., D.C.L., Keeper of Department of Oriental Antiquities, British Museum.
AMMUNITION. Capt. C. Orde Browne, R.A.. Royal Laboratory. Woolwich.
AMOS. Rev. Canon T. K. Cheyne, Oriel Professor of Exegesis, University of Oxford.
AMPHIBIA. Prof. T. H. Huxley.
A.Ml'IIITHEATRE. Rev. G. H. FORBES.
ANALO(;y and analysis. Prof. Croom Robertson.
AN.ESTHESIA. Dr. James O. Affleck. Examiner, Royal College of Physicians. Edinburgh.
ANATOMY. Sir Wm. Turner. M.B.. F.R.S., Professor of Auatomy in the University of Edinburgh.
PREFATORY NOTICE.
' I "HE En'CYCLOP^DIA Britann'ICA has long deservedly held a foremost place amongst
-*- English Encyclopaedias. It secured this position by its plan and method of treat-
ment, the plan being more comprehensive, and the treatment a happier blending of
popular and scientific exposition than had previously been attempted in any under-
taking of the kind. The distinctive feature of the work was that it gave a connecttid
view of the more important subjects under a single heading, instead of breaking them
up into a number of shorter articles. This method of arrangement had a twofold
advantage. The space afforded for extended exposition helped to secure the services
of the more independent and productive minds who were engaged in advancing their
own departments of scientific inquiry. As a natural result, the work, while surveying
in outline the existing field of knowledge, was able at the same tiine to enlarge its
boundaries by embodying, in special articles, the fruits of original observation and re-
search. The Encyclopjedia Britannica thus became, to some extent at least, an instru-
ment as well as a register of scientific progress.
This characteristic feature of the work will be retained and made even more promi-
nent in the New Edition, as the list of contributors already published sufficiently
indicates. In some other respects, however, the plan will be modified, to meet the
multiplied requirements of advancing knowledge. In the first place, the rapid progress
of science during the last quarter of a century necessitates many changes, as well as a
considerable increase in the number of headings devoted to its exposition. In dealing
with vast wholes, such as Physics and Biology, it is always a difficult problem how
best to distribute the parts under an alphabetical arrangement, and perhaps impossible
to make such a distribution perfectly consistent and complete. The difficulty of dis-
tribution is increased by the complexity of divisions and multiplication of details, which
the progress of science involves, and which constitute indeed the most authentic note
of advancing knowledge. This sign of progress is reflected in extensive changes of
terminology and nomenclature, vague general headings once appropriate and sufficient,
such as Animalcule, being of necessity abandoned for more precise and significant
equivalents.
VI rREFATOR\' NOTICE.
But, since the publication of the last Edition, science, in each of its main divisions,
may be said to have changed as much in substance as in form. The new conceptions
introduced into the Biological Sciences have revolutionized their points of view, methods
of procedure, and systems of classification. In the light of larger and more illumi-
nating generalizations, sections of the subject, hitherto only partially explored, have
acquired new prominence and value, and are cultivated with the keenest interest. It is
enough to specify the researches into the ultimate structures, serial gradations, and pro-
gressive changes of organic forms, into the laws of their distribution in space and time,
and into the causes by which these phenomena have been brought about. The results
of persistent labor in these comparatively new fields of inquiry will largely determine
the classifications of the future. Meanwhile the whole system of grouping, and many
points of general doctrine, are in a transition state; and what is said and done in these
directions must be regarded, to a certain extent at least, as tentative and provisional.
In these circumstances, the really important thing is, that whatever may be said on
such unsettled questions should be said with the authority of the fullest knowledge and
insight, and every effort has been made to secure this advantage for the New Edition
of the Encyclopaedia.
The recent history of Physics is marked by changes both of conception and classi-
fication almost equally great. In advancing from the older dynamic to the newer
potential and kinetic conceptions of power, this branch of science may be said to have
entered on a fresh stage, in which, instead of regarding natural phenomena as the result
of forces acting between one bod\' and another, the energy of a material system is
looked upon as determined by its configuration and motion, and the ideas of configura-
tion, motion and force are generalized to the utmost extent warranted by their defini-
tions. This altered point of view, combined with the far-reaching doctrines of the
correlation of forces and the conservation of energy, has produced extensive changes in
the nomenclature and classification of the various sections of pliysics ; w hile the fuller
investigations into tiie ultimate constitution of matter, and into the phenomena and
laws of light, heat and electricity, have created virtually new sections, which must now
find a place in any adequate survey of scientific progress. The application of the
newer principles to the mechanical arts antl industries has rapidly advanced during the
same period, and will require extended illustration in many fresh directions. Mechanical
invention has, indeed, so kept pace \\ith the progress of science, that in almost every
department of physics improved machines and processes have to be described, as well
as fresh discoveries and altered points of view. In recent as in earlier times, invention
and discovery have acted and reacted on each other to a marked extent, the instru-
ments of finer measurement and analysis having directly contributed to the finding out
of physical properties and laws. The spectroscope is a signal instance of the extent to
which in our day scientific discovery is indebted to appropriate instruments of obser-
vation and analysis.
PREFATORY NOTICE. Vll
These extensive changes in Physics and Biology involve corresponding changes in
the method of their exposition. Much in what was written about each a generation
ago is now of comparatively little value. Not only therefore does the system of
grouping in these sciences require alteration and enlargement ; the articles themselves
must, in the majority of instances, be written afresh rather than simply revised. The
scientific department of the work will thus be to a great extent new. In attempting
to distribute the headings for the New Edition, so as fairly to cover the ground occu-
pied by modern science, I have been largely indebted to Professor Huxley and Professor
Clerk Maxwell, whose valuable help in the matter I am glad to have an opportunity
of acknowledging.
Passing from Natural and Physical Science to Literature, History and Philosophy,
it may be noted that many sections of knowledge connected with these departments
display fresh tendencies, and are working towards new results, which, if faithfully
reflected, will require a new style of treatment. Speaking generally, it may be said
that human nature and human life are the great objects of inquiry in these depart-
ments. Man, in his individual powers, complex relationships, associated activities and
collective progress, is dealt with alike in Literature, History and Philosophy. In this
wider aspect, the rudest and most fragmentary records of savage and barbarous races,
the earliest stories and traditions of every lettered people, no less than their developed
literatures, mythologies and religions, are found to have a meaning and value of their
own. As yet the rich materials thus supplied for throwing light on the central prob-
lems of human life and history have only been very partially turned to account. It
may be said, indeed, that their real significance is perceived and appreciated, almost for
the first time in our own day. But under the influence of the modern spirit, they are
now being dealt with in a strictly scientific manner. The available facts of human
history, collected over the widest areas, are carefully co-ordinated and grouped together,
in the hope of ultimately evolving the laws of progress, moral and material, which
underlie them, and which, when evolved, will help to connect and interpret the whole
onward movement of the race. Already the critical use of the comparative method
has produced very striking results in this new and stimulating field of research. Illus-
trations of this are seen in the rise and rapid development of the comparatively modern
science of Anthropology, and the successful cultivation of the assistant sciences, such as
Archaeology, Ethnography and Philology, which directly contribute materials for its use.
The activity of geographical research in both hemispheres, and the large additions
recently made to our knowledge of older and newer continents by the discoveries of
eminent travelers and explorers, afTord the anthropologist additional materials for his
work. Many branches of mental philosophy, again, such as Ethics, Psychology and
^Esthetics, while supplying important elements to the new science, arc at the same
time very largely interested in its results, and all may be regarded as subservient to
the wider problems raised by the philosophy of history. In the New Edition of the
Vlll PREFATORY NOTICE.
Encyclopaidia full justice will, it is hoped, be done to the progress made in these
various directions.
It may be well, perhaps, to state at the outset the position taken by the Ency-
clopaedia Britannica in relation to the active controversies of the time— Scientific, Re-
ligious and Philosophical. This is the more necessary, as the prolific activity of modern
science has naturally stimulated speculation, and given birth to a number of somewhat
crude conjectures and hypotheses. The air is full of novel and extreme opinions,
arising often from a hasty or one-sided interpretation of the newer aspects and results
of modern inquiry. The higher problems oi philosophy and religion, too, are being
investigated afresh from opposite sides in a thoroughly earnest spirit, as well as with a
directness and intellectual power, which is certainly one of the most striking signs of
the times. This fresh outbreak of the inevitable contest between the old and the new
is a fruitful source of exaggerated hopes and fears, and of excited denunciation and
appeal. In this conflict a work like the Encyclopaedia is not called upon to take any
direct part. It has to do with knowledge rather than opinion, and to deal with all
subjects from a critical and historical, rather than a dogmatic, point of view. It cannot
be the organ of any sect or party in Science, Religion or Philosophy. Its main duty
is to give an accurate account of the facts and an impartial summary of results in
every department of inquiry and research. This duty will, I hope, be faithfully
performed.
T. S. BAYNES.
ENCYCL0PJ1D.TA BEITANNICA.
A
THE Grst symbol of every Indo-European alphabet,
. denotes also tlio primary vowel sound. This coin-
cidence is probably only accidental The alphabets of
Europe, and perhaps of India also, were of Semitic origin,
and in all the Semitic alphabets except one, this same
symbol (in modified forms) holds the first place ; but it
represents a peculiar breathing, not the vowel a, — the
Tovpels in the Semitic languages occupying a subordinate
place, and having originally no special symbols. When
the Greeks, with whom the vowel sounds were much more
important, borrowed the alphabet of Phoenicia, they re-
quired symbols to express those vowels, and Esed for this
purpose the signs of breathings which were strange to
them, and therefore needed not to be preserved ; thus the
Phceuician equivalent of the Hebrew aieph became alpha;
it denoted, however, no more a guttural breathing, but the
purest vowel sound. Still, it would be too much to
assume that the Greeks of that day were so skilled in
phonetics that they assigned the first symbol of their bor-
rowed alphabet to the <7,-sound, bccaiue they knew that
sound to be the most essential voweL
This primary vowel-sound (the sound of a ia/aUier) is
produced by keeping the passage through which the air is
vocalised between the glottis and the lips in the most opeu
position possible. In sounding all other vowels, '.ho air-
channel is narrowed by the action either of the tongue or
the Ups. But hero neither the back of the tongue is
raised (as it is in sounding o and other vowels), so that a
free space is left between the tongue and the uvula, nor
ia the front of the tongue raised (as in aounding r), so that
the space ia clear between the tongue and the palate.
Again, no other vowel is pronounced with a wider opciuiig
of the lips ; whereas the aperture is sensibly reduced at
each side when we sound o, and still more when wo sound
u (that is, yoo). The whole channel, therefore, from
the glottis, where the breath first issues forth to be modi-
fied in the oral cavity, to the lips, where it finally escapes,
•a thoroughly open. Hence arises the great importance of
the sound, by reason of its thoroughly non-consonantal
character. Ail vowels may bo defmeJ a.i open positions
1—1
of the speech-organs, in which the breath escapes withotil
any stoppage, fricticin, or sibilatiou arising from the con-
t-act of those organs, whereas consonants are heard when
the organs open after such contact more or less complete.
Now, all vowels except a are pronounced with a certain
contraction of the organs ; thus, in sounding the t (the
English «-sound), the tongue is raised so as almost to
touch the palate, the passage left being so close, that if
the tongue were sufl'ercd for a second to rest on the palate,
there would be heard not i but y; and a similar relation
exists between u and w. This is commonly expressed by
calling ff and ic semi-vowels. Wo might more exactly caH
t and It consonantal- vowels; and as an historic fact, t docs
constantly pass into y, and ti into w, and vice versa. But
no consonant has this relation to the a-sound ; it has abso-
lutely no affinity to any consonant ; it is, as we have called
it, the one primary essential vowel.
The importance of this scihnd may be shown by histori-
cal as well as by physiological evidence. Wo find by
tracing the process of phonetic change in different lan-
guages, that when one vowel passes into another, it is the
pure a-sound which thus a-'usumes other forms, wherca-i
other vowels do not pass into tlie a-sound, though some-
times the new sound may have tliis symbol, KougUy
speaking, we might express the gene- ^
ml character of vowel change by draw-
ing two lines from a coiamon point,
at which a is placed. One of thcso
lines marks the progress of an original
a (aA-sound) through e (a-sound), till
it sinks finally to t («-sound) ; the oilier
o to « (oo-sound). This figure omits
many miuor modifications, and is sub-
ject to some exceptions in particular languages. Put it
represents fairly in the main the general jiroccss of vowel-
change. Now, we do not a-ssert that there ever was a
time when a was the only existing vowel, but we do main-
tain that in numberless cases au originjl a has pa.sstd into
other sounds, whereas the revcrso process is excessively
1. — I
A A R
rare. Consequently, the farther wo trace back the history
of language, the more instances of this vowel do we find ;
the more nearly, if not entirely, does it become the one
starting point from which all vowel-sound is derived.
It is principally to the effort required to keep this
sound pure that wo must attribute the great corruption of
it in all languages, and iu none more than our own. In-
deed, in English, the short a-sound is never heard pure ; it
is heard in Scotland, e.g., in man, which is quite difl'ercnt
from the same word on English lips. We have it, how-
ever, long m father, kc, though it is not common. It has
passed into a great many other sounds, all of which are
denoted in a most confusing way by the original symbol,
and some by other symbols as well. Thus a denotes — (1.)
The English vowel-sound in man, perhaps the most common
of all the .substitutes, dating from tho 17th century. (2.)
It appears in want; for tliis sound o is also employed, as in
on. (3.) A more open sound is heard in alt (also denoted
by au in auk, and aw in atd). (4.) Very commonly it re-
presents the continental e, as in ale (here also we have the
s}Tnbol ai in ail). (5.) It is found in dare and many
similar words, where the sound is really the e of den, pro-
longed in the utterance ; hero also ai is sometimes an
equivalent, as iu air. Then (6) there is a sound which is
not that of a either in mare or in father, but something
between the two. It is heard in such words as ask, pass,
grant, ic. All these may be, and often are, pronounced
with the sound either of man or oi father; still, we do often
lear in them a clearly tlistinguishable intennediate sound,
■which ought to have a special symbol. Lastly (7), there
is the dull*aound heard in fmal unaccentuated syllables, e.g.,
in the word final itself. It is that to which all unaccen;
tuated syllables tend ; but it is also often heard even in
monosyllables, where it is represented by every other vowel-
symbol in the language, e.g., in her, sir, son, suti. This
Protean sound is commonly called the neutral vowel ; it
occurs in all languages, but perhaps in none so frequently
as in English. This great variety of sounds, which are all
denoted among us by one sj-mbol, clearly shows the in-
iulEciency of our written alphabet.
As in English, so in Sanskrit, the short a/i-sound was
lost, and was replaced regularly by the neutral sound.
This was regarded by the grammarians as inherent in every
consonant, and therefore was only written at the beginning
of a word ; in fact, it is the smallest amount of vowel-
eound requisite to float a consonant. Long a, however,
kept its sound pure, aad does so stUl in the vernaculars of
India. In Latin the sound was probably pure, both short
and long, and it has been .preserved so in the Romance
lajiguagcs down to the present day. In Greek there was
considerable variation, proved in one case at least by a
variation of sjinbol ; in Jonic a commonly passed into
r], a sjrmbol which probably denoted the modern Italian
open e ; but possibly the close e, that is, the English a in
ale. On the other hand, it is probable that the Doric a
approximated to au o, being sounded as a in our word
loant; and it is likely that this variation was the TrXartiao--
^tos which the grammarians attribute to the Dorians. This
is commonly sap,posed to have been the retention of a where
the Ionic had rj ; but that was not peculiar to the Dorians,
being common to all tho Greeks except the lonians. In
the north of Europe we find a similar tendency to give to'
oiji o-sound,; thus in Norse, aa, is sounded as an open o. '
By' a further cxt'cnsion in the'north of England, at least in
such parts as have been gpeciiAIy exposed to Norwegian
inJ5uence,.ff«has the sound of o ; e.g., law is pronounced lo.
A is frequently usefl as a jjrefix^in Ucu of some- fuller
form in old English. Thus •It stands for tho preposition
an (O.E. 071) in an'ay, again, afoot, asleep; for o/f in odowif
(O.E. of-dune) ; and seems lo bo intonsive in athirst (O.E.
ofthirst). Sometimes, opcciu'Jy with verb*, it reprcsenta
the old English &, which in old liljjh German apjieari as
ur or er, and in modem German as er, which signilics the
completion of an action, as in ermachen, to v>hich awake
corresponds. Frequently no special force sccma to ba
added by tho prefix, as in abide, arise, Ac. Sometimes a
appears as the representative of tho prefix commonly used
in past participles, which has the form ge in German, and
ge and y in old English, e.g., in ago or qgone; compare
aware (O.E. gewaere), among (O.E. gemang), ic. A also
stood for the preposition an (on) in such expressions (now
obsolete) as a-doing, a-making, where doing and making are
verbal nouns. Lastly, it represents the prepositions on or
af in the phrases nowa-days, Jack-a-lantem, and others.
Tho place that A occupies ill the alphabet accounts for
its being much employed as a mark or eymboL It is used,
for instance, to name the sixth note of the gamut in music;
in some systems of notation it is a numeral (see Akith-
METic); and in Logic it denotes a universal affirmative
proposition (see Looic). In algebra, a and the first letters
of the alphabet are employed to represent known quanti-
ties. AI marks the best class of vessels in Lloyds Re-
gister of British and Foreign Shipping. In the old poets,
" Aper se" is found, meaning the highest degree of excel-
lence; as when Chaucer calls Creseide "the floure and A
per ee of Troyo and Grcce."
A was the first of the eight literoe nundinalet at Rome,
and on this analogy it stands as the first of the sev^ Domini-
cal letters.
It is often used as an abbreviation, as in A.D. for anno
domini, A.M. for ante meridiem, A.B. and A.M. for artivm
haccalaureus and artium magister. In commerce A stands
for accepted. (j. P.)
AA, the name of about forty small European rivers.
The word is derived from the old German aha, cognate
to the Latin aqua, water. The following are the more
important streams of this name : — a river of Holland, in
North Brabant, which joins the Dommcl at Bois-le-Duc ;
two rivers in the west of Russia, both falling into the
Gulf of Livonia, near Riga, which is situated between
them; a river in the north of France, falling into the sea
at Gravelines, and navigable as far as St Omer; and a
river of Switzerland, in the cantons of Lucerne and Aargau,
which carries the waters of Lakes Baldeker and Hallwyler
into the Aar.
AACIIEN. See Aix-la-Chapelle.
AALBORG, a city and seaport of Denmark, is situated on
the T'iimfiord, about 15 miles from its junction with the
Cattegat. It is the capital of the district of •Xhe same
name, one of the subdivisions of the province of Jiitland.
The city is a place of xonsiderable commercial importance,
and contains a cathedral and a school of navigation. Soap,
tobacco, and leather are manufactured ; there are several
distilleries ; and the herring fishery is extensively prosecuted.
Grain and herring are largely exported, as are also to a
smaller extent wool, cattle, skins, tallow, salt provisiong, and
spirits. The harbour, which is good and safe, though
difficult of access, is entered by about 800 vessels annually,
and there is direct steam communication with Copenliageu.
Tlie district is celebrated for its breed of horses. Popula
tion (1870), 11,953.
AALEN, a. walled town of Wurtemberg, pleasantly
' situated on the Kocher, at the foot of the Swabian Alps,
about 50 milea E! of Stuttgart. . Woollen and linen goods
are manufactured, and there are ribbon looms and tanneries
in the town, and large iron works in the neighbourhoodi
Aalen- was a free imperial city from 13G0 till 1802, when
it was annexed to Wurtemberg. Population (1871), 5552. ,
AAR, or Aake, the most considerable river in Swi^er-
hnd. after the Rhine and Rhon>^ It rises in the glaciers
A A R — A A R
of the Finster-oaj-uorufSchreekhoni, ana Qrimsel, in the
canton of Bern; and at the Handeck in the valley of Hash
forma a magnificent water-fall of above 150 feet in height.
It then falls successively into the lakes Brienz and Thun,
and, emerging from the latter, flews through the cantons of
Bern, Soleure, and Aargau, emptying itself into the Rhine,
opposite Waldshut, after a course of about 170 miles.
Its principal tributary streams are the Kander, Saane, and
Thiele on the left, and the Emmen, Surin, Aa, Reuss, and
Limiaat, on the right. On its banks are situated' Unterseen,
Thun, Bern, Soleure or Solothum, Aarburg, and Aarau.
The Aar is a beautiful silvery river, abounding Ln fish, and
is navigable from the Rhine as far as the Lake of Thun.
Several small rivers in Germany have the same name.
AARAU, the chief town of the canton of Aargau in
Switzerland, is situated at the foot of the Jura mountains,
on the right bank of the river Aar, 41 miles N.E. of Bern.
It is well built, and contains a town-hall, barracks, several
eqiall museums, and a library rich in histories of Switzer-
land. There is a cannon foundry at Aarau, and among the
principal manufacture^ are silk, cotton, and leather ; also
cutlery and mathematical instruments, which are held in
great repute. The slopes of the neighbouring mountains
are partially covered with vines, and the vicinity of the
town is attractive. About ten miles distant along the
right bank of the Aar are the famous baths of Schinznach.
PopiJation, 5449.
AARD-VARK (eartr,-pig), an animal very common in
South Africa, measuring upwards of three feet in length,
and having a general resemblance to a short-legged pig.
It feeds on ants, and is of nocturnal habits, and very timid
and harmless. Its flesh is used as food, and when suitably
preserved is considered a delicacy. The animal is the only
known species of its genus (Oryderopus), and belongs to
the order Edentata of the mammalia. The same prefix
Aard appears in the name of the Aaed-wolf (Proteles
Lalandii)^ a rare animal found in Cafi'raria, which is said
to partake of the characters of the dog and civet. See
MiMMAtlA
AARGAU (French, Aegovie), one of fhe cantons of
Switzerland, derives its name from the river which flows
through it, Aar-gau being the province or district of the
Aar. It is bounded on the north by the Rhine, which divides
it from the duchy of Baden, on the east by Zurich and Zug,
on the south by Lucerne, and on the west by Bern, Soleure
or Solothurn, and Basel. It has an area of 502 1 square miles.
By the census of 1870, the number of inhabitants was
19'i,873, showing an increase during the preceding ten years
of 4665. Aargau stands sixth among theSwiss cantons in
density of population, having 395 inhabitants to the square
mile. The statistics of 1870 show that of the inhabitants
107,703 were Protestants, 89,180 Catholics, and 1541 Jews.
German is the language almost universally spokei.
Aargau .is the least mountainous canton of Switzerland.
It forms part of a great table'land to the north of the Alps
and the cast of the Jura, having a general elevation of
from 1200 te 1500 feet. The hills do not rise to any
greater height-than 1800 feet above this, table-land,, or
3000 feet above the level' of the sea. The surface of the.
country 'is beautifully diversified, undulating tracts and
Vrell-wooded hills alternating with fertile valleys watered
by the Aar and its numerous tributaries, and by the rivu-
lets' which flow 'northward into the Rhine. Although
moist and variable, the climate is Inildcr than in most
parts of Switzerland.
The miiicrals of Aargau are unimportant, but remarkable
palEontological reinains are found in its rocks. The soil to
tho left of the Aar is a stifl' clay, but to the right it is light
and productive. Agriculture is in an advanced state, and
great attention is given to tho rearing of cattle. Thero
are many vineyards, and much fruit is grown. The can-
ton is distinguished by its industry and its generally
diffused prosperity. Many of the inhabitants are employed
in the fishings on the Aar, and in the navigation of the
river. In the villages and towns there are considerable
manufactures of cotton goods, silk, and linen. The chief
exports are cattle, hides, cheese, timber, raw cotton, yam,
cotton cloths, silk, machinery, and wooden wares ; and
the imports include wheat, wine, salt, leather, and iron.
The most important towns are Aarau, Baden, Zofingen, and
Laufenburg, and there are mineral springs at Baden, Schinz-
nach, Leerau, and NiederweiL The Swiss Junction
Railway crosses the Rhine near Waldshut, and runs south
through the canton to Turgi, whence one line proceeds S.E.
to Zurich, and another S.\V. to Aarau and Olben.
Untd 1798, Aargau formed part of the canton of Bern,
out when the Helvetic Republic was proclaimed, it was
erected into a separate canton. In 1803 it received a
considerable accession of territory, in virtue of the arrange-
ment under which tho French evacuated Switzerland.
According to the law whereby the cantons are represented
in the National Council by one member for every 20,000
inhabitants, Aargau returns ten representatives to that
assembly. The internal government is vested in a legis-
lative council elected by the body of the pecple, while a
smaller councO of seven members is chosen by the larger
body for the general administration of affairs. The re-
sources of Aargau are stated to am.iunt to about a million
sterling; its revenue in 1807 was nearly £82,000, and the
expenditure slightly greater. There is a pubUc debt of
about X40,000. The canton is divided into eleven districts,
and these again are subdivided into forty-eight circles. There
is a court of law for each district, and a superior court for
the whole canton, to which cases involving sums above 160
francs can be appealed. Education is compulsory; but in the
Roman Catholie districts the law is not strictly enforced. By
[improved schools and other .appUances great progress has
been made in education withfn the last thirfy or forty years.
AARHUUS, a city and seaport of Denmark, situated
on the Cattegat, in lat. 56° 9' K, long. 10° 12'.E. It is
the chief town of a fertile district of the same name, one
of the subtlivisions of Jutland. The cathedral of Aarhuus
is a Gothic structure, and the largest church in Denmark.
The town also contains a lyccum, museum, and library.
Aarhuus is a phice of extensive trade. It has a good and
safe harbour, has regular steam communication with
Copenhagen, and is connected by rail with Viborg and the
interior of the country. Agricultural produce, spirits,
l,eathor, and gloves are e.xported, arid there are sugar r'e-
fineries, and manufactures of jvool^ cottor^ - and tobacco.
Popidation (1870), 15,020.
AARON, the first high-priest of the ./ews, eldest Fon
of Amram and Jochebed, of the tribe of Levi, and brother
of Moses and Miriam. When Moses was comniissioned to
conduct the IsraeUtes from Egypt to Canaan, Aaron was
i^)pointed to assist him, principally, it would appeaf, on
account of his possessing,' in a high degree, persuasive
readiness of speech. On the occasion 'of Moses' .abstince
in Mount Binaii(to which he had gone up to rec?^e tho
tiibles of tho law), .the Israelites, regarding Aaron as their
leader,' chniorously demanded that he should provide them
with a 'visible sj-mbolic imago of 'ihcir .God for worship.
He weakly compUed with the derannd/ and put of the
ornaments of gold, contributed for tho purpose cast tho
figure of a calf, tlus form being •doubtless chosen in recol-
lection of Yhe idols of Egypt. In obedience to*ins(|(uctiona
given by'God to Moses, Aaron was appointed high-priest;
his sons and descendants, priests ; and his tribe wa« set
'a|)art as the saoerdoUd caste. The oftico of high-priest was
held by Aaron for-lieaxly forty years, tiM the time of his
A A 11 — A B A
death, which took i)lacc or, Mouut Hor, wLcu he was 123
years old.
AAKSSENS, Francis Van (1572-1641), one of the
greatest diplomatists of th? Uiitcd Provinces. He re-
presented the Statcs-Generol at the Court of France for
many years, and was also eng'aij'^l in embassies to Venice,
Germany, and England. hi.i I'/cat diplomatic ability
jppears from the memoirs ht VMoto of his negotiations
in 1024 with Hichehcu, who rauki i him among the three
greatest politicians of his time. A deep stain rests on the
memory of Aarssens from the shan ho had in the death of
Barneveldt, who was put to death by the States-General,
after the semblance of a trial, in I'lO.
ABABDE, an African tribe occ.ipj-ing tho country be-
tween the lied Sea and. the Nile, to the S. of Kosseir,
nearly as far as the latitude of D.rr. Many of the race
have settled on the eastern bank of the Nile, but the
greater part EtiU live like Bedouins. They arc a distinct
race from tho Arabs, and are treacherous and faithless in
their dealings. They have few horses ; when at war with
other tribes, they fight from camels, their breed of which
is famed. Tliey possess considerable property, and trade
in senna, and in charcoal made from acacia wood, which
they send as far as Cairo.
ABACA or AuAK-i, a name given to the Jfusa texlihs,
the plant that. produces the fibre called JIaiulla Hemp,
and also to the fibre itself.
ABACUS, an architectural term (from the G.-. a/3af, a
tray or flat board) apphed to the upper part of the capital
of a column, pier, ic. The early form of an abacus Ls
Forma of the AKicug,
simply a square fiat stone, probably derived from the
Tuscan order. In Saxon work it is frequently simply
chamfered, but srimetimes grooved, as in tho crj'pt at
Repton (fig. 1), ana in the arcade of the refectory at West-
minster. The abacus in Norman work is square where
the columns are small; but on larger piers it is sometmies
octagonal, as at Waltham Abbey. The square of the
abacus is often sculptured, as at the \VTiite Tower and
at Alton (fig. 2). In early English work the abacus is
generally circular, and in larger work a continuation of
circles (fig. 4), sometimes octagonal, and occasionally squaru.
The mouldings are
generally rounds,
which overhang
deep hollows. The
abacus in early
French work is
generally square, as
at Blois (fig. 3).
The term is ap-
pbed in its diminu-
tive form (Abacis-
cus) to the chequers
or squares of a tes-
seUated pavement.
Fig. 5. — Roman Abacus.
Ab-vcus also signifies an instrument employed by the
• ncients for arithmetical calculations; pebbles, bits of bone,
or coins,'being used as counters. The accompanying figure
(5) of a Eoman abacus is taken from an ancient monu-
ment. ■ It contains seven long and seven shorter rods or
hars, the former having fonr perforated beads running oti
thera, and the latter one. The b.ar marked I indicates
units, X tens, and so on up to millions. The beads ou the
shorter bars denote lives, — five units, five tens, <fec. The rod
O and correspond-
ing short rod are
for marking ounces;
and the short quar-
ter rods for fractions
of an ounce.
The Swan-Pan of
the Chinese (fig. 6)
closely resembles tho
Koman abacus in its i'S- 6.— Clunesi; Swan-Pan.
construction and usa Computations are made with it fcy
means of balls of bone or ivory running on slender bam-
boo rods similar to the simpler board, fitted up with beads
strung on vrircs, which is employed in teaching the rudi-
ments of arithmetic in elementary schools.
AB/E, a town of ancient Greece in the E. of Phocis
famous for a teniplo and oracle of Apollo. The temple ^yas
plundered and burned by tho Persians (B.C. 480), and again
by the Boeotians (B.C. 34C), and was re,stored on a smallei
scale by lladrian. Kemains of the temple and town may
still be traced on a peaked hill near Exarkho. See Leake's
NorthtTii Greece.
AB.VKANSK, a fortified town of Siberia, in the govern-
ment of Yeniseisk, on the river Abakan, near its coufluenca
with tho Yenisei. Lat 54° N.; long. 91° 14' E. This is
considered the mildest and most s.alubrious place in Siberia,
and is remark.ablo for the tumuli in its neighbourhood, and
for some statues of men from seven to nine feet high,
covered « ith hieroglyphics. Population about lOOO.
AE:\JNA and Puaepae, "rivers of Damascus" (2 Kings
V. 12), are now generally identified with the Barada and
the Awaj respectively. The former flows through the city
of Damascus ; the Awaj, a smaller stream, passes eight
miles to the south. Both run from west to east across the
plain of Damascus, which owes to them much of its fertility,
and lose themselves in marshes, or lakes, as they are called,
on the borders of the great Arabian desert Mr Macgrcgor,
who gives an interesting description of these rivers in his
I'^ob Hoy on, the Jordan, affirms that " as a work of
hydraulic engineering, the system and constraction of the
CiUials by which the Abana and Pharpar are used for
irrigation, may be still considered as the most complete
and extensive in the world."
ABANCAY, a tovra of Peru, in the department of
Cuzco, 65.miles W.S.W. of the town of Lh.at name. It Uea
on tho river Abancay, which is here spanned by one of the
finest bridges in Pom. Rich crops of sugar-cate are pro-
duced in the district, and the town has extensive sugar
refineries. Hemp is also cultivated, and silver is found io
the mountains. Population, 1200.
ABANDONMENT, in Marine Assurance, is the surren-
dering of the ship or goods insured to the insurers, in the
case of a constructive total loss of the thing insured.
There is an absolute total loss entitling tho assured to
recover the full amount of his insurance wherever the thing
insured has ceased to exist to any useful purpose, — and in
such a case abandonment is not required. Where the thing
assured continues to exist in specie, yet is so damaged that
there is no reasonable hope of repau-, c^r it is not worth the
expense of bringing it, or what remains of it, to its destiuiw-
tion, the insured may treat the case as one of a total loss
(in this case called constructive total loss), and demand
the full sum insured. But, as the contract of insurance is
one of indemnity, the insured must, in such a case, make
an express cession of all his right to the recovery of the
subject insured to the underwriter by abandonment. Tho
insured must intimate his intention to abandon, within «
-A. B A - A B A
5
tea3onatle tiiije after receiving correoi information as to
the loss; any unnecessary delay being held as an indica-
tion of his intention not to abandon. An abandonment
when once accepted is irreTocable; but in no circumstances
s the insured obliged to abandon. After abandonment,
the captain and crew are still bound to do all in their
power to save the property for the underwriter, without
prejudice to the right of abandonment; for which they are
entitled to wages and remuneration from the insurers, at
least so far as what is saved-wiU allow. See Aruould,
Marshall, aud Park, on the Law of Insurance, and the
judgment of Lord Abinger in Roux v. Salvador, 3 Bing.
N.C. 26_6, Tudor's Leadiny Cases, 139.
Abandonment has also a legal signification m the law
of railways. Under the Acts 13 and li Vict. c. 83, 14
and 15 Vict. c. 64, 30 and 31 Vict. c. 126, aud 32 and 33
Vict. c. 114, the Board of Trade may, on the application
of a railway company, made by the authority and with the
consent of the holders of three-fifths of its shares or stock,
and on certain conditions specified in the Acts, grant a war-
rant authorising the abandonment of the railway or a por-
tion of it. After duo publication of this warrant, the
company is released from all liability to make, maintain,
or work the" railway, or portion of the railway, authorised
to be abandoned, or to complete any contracts "elating to
it, subject to certain provisions and exceptions.
Abandoning a young child under two years of age, so
that its life shall be endangered, or its health permanently
injured, or likely to be so, is in England a misdemeanour,
punishable by penal servitude or imprisonment, 24 and 25
Vict. c. 100, § 273. In Scotland abandoning or exposing
an infant ia an offence at common law, although no evil
consequences should happen to the child.
A.BANO, a town of Northern Italy, 6 miles S.W. of
Padua. There are thennal springs in the neighbourhood,
which have been much resorted to by invalids for bathing,
both in ancient and modern times. They were called by
the Romans Aponi Foiis, and also Aauce Patavina:. Popu-
lation of Abano, 3000.
ABANO, PiETEO d', known also as Petnis de Apone or
Aponensis, a distinguished physician and philosopher, was
born at the Italian towji from which he takes his name in
• 1250, or, according to others, in 1246. After vi.siting the
east in order to acquire the Greek language, he went to
study at Pari.s, where he became a doctor of medicine and
philosophy. In Padua, to which he returned when his
studies were completed, he speedily gained a great reputa-
tion as a physician, and availed hinaself of it to gratify his
ivarice by refusing to visit patients except for an exorbitant
fee. Perhaps this as well as his meddling v/ith astrology
caused the charge to bo brought against him of practising
magic, the particular accusations being that he brought
back into his purse, by the aid of the devil, all the money
he paid away, and that he possessed the philosophei-'s stone.
He was twice brought to trial by the Inquisition ; on the
first occasion he was acquitted, aud he died (1316) before
the second trial was completed. He was found guilty,
however, and his body was ordered to be e.xlmmed and
burned; but a friend had secretly removed it, and the
Inquisition had, therefore, to content itself with the public
proclamation of its sentence and the burning of Abano in
effigy. In his writings he expounds and advocates the
medical and philosophical systems of Averrhoes and other
Arabian ^vTitcrs. His best known works are the Con-
ciliator diffcrcnliarvm qua; inter philosophos et medicos
versantur (Mantua, 1472, Venice, 1476), and De venenis
torumque remediis (1472), of which a French translation
was published at Lyons in 1593.
ABARIS, the Hyperborean, a celebrated sago of anti-
quity, whoi-isited Greece about 570 B.C., or, according to
others, a centuij or two earlier. The particulars of his
history are diiferently related by different authors, but all
accounts are more or less mj-thicaL He is said to have
travelled over sea and land, riding on an arrow given him
by Apollo, to have lived without food, to have deUvered
the whole earth from a plague, &c. Various works in prose
and verse are attributed to Abaris by Suidas and others,
but of these we have no certain information.
ABATEMENT, Abate, from the French abattre, abater,
to throw down, demolish. The original meaning of the
word is preserved in various legal phrases. The abatement
of a nuisance is the remedy allowed by law to a person
injured by a public nuisance of destroying or removing it
by his own act, provided he commit no breach of the peace
ill doing so. In the case of private nuisances abatement
is also allowed, provided there be no breach of the peace,
and no damage be occasioned bevond vhat the removal ol
the nuisance requires.
Abatement of freehold takes pjiace where, alter the aeath
of the person last seised, a stranger enters upon lands
before the entry of the heir or devisee, and keeps the latte*
out of possession. It differs from intrusion, which is a
similar entry by a stranger on the death of a tenant for
life, to the prejudice of the reversioner, or remainder man ;
and from disseisin, which is the forcible or fraudulent ex-
pulsion of a person seised of the freehold.
Abatement among legatees (de/alcatis) is a proportionate
deduction which their legacies suffer when the funds out
of which they are payable are not sufficient to Day them in
full.
Abatement in pleading is the defeating or quashing of a
particular action by some matter of fact, such as a defect
in form or personal incompetency of the parties suing,
pleaded by the defendant. Such a plea is called a plea in
aliatemeut; and as it does not involve the merits of the
cause, it leaves the right of action subsisting. Since 1852
it has been competent to obviate the effect of such pleas
by amendment, so as to allow the real question in contro-
versy between the parties t- be tried in the same suit.
In litigation an action is said to abate or cease on the
death of one of the parties.
Abatement, or Rebate, is a discount allowed for
prompt payment ; it also means a deduction sometimes
made at the custom-house from the fixed duties on certain
kinds of goods, on account of damage or loss sustained in
warehouses. The rate and conditions of such deductions
are regulated by Act 16 and 17 Vict. c. 107.
ABATI, or Dell'Aebato, Niccolo, a celebrated fresco-
painter of Modena, born in 1512. His best works are at
Wodena and Bologna, and have been highly praised by
Zanotti, Algarotti, and Lanzi. He accompanied Primaticcio
to France, and assisted in decorating the palace at Fontain-
bleau (1552-1571). His pictures exhibit a combination of
skill in drawiug, grace, aud natural colouring. Some of
his easel pieces in oil are in different collections ; one of the
finest, now in the Dresden Gallery, represents the martyr-
dom of St Peter and ,St PauL Abati died at Paris in
1571.
ABATTOIR, from abattre, primarily signifies a slaughter-
house jiroper, or place where animals are killed as distin-
guished from boucheries and itaux publics, places where
the dead meat is offered for sale. But the term is al.=o
employed to designate a complete meat market of which
the abattoir proper is merely part.
Perhaps fiio first indication of the existence of abattoirs
may be found in the system which prevailed under the
Emperors in ancient Rome. A corporation or guild of
butchers undoubtedly e.xisted there, which delegated to its
ollicei-s the duty of slaiigliterinf,' the l)fa.sts iwjiiired to
supply the city with meat. The establishments requisite
6
A B A,T T O I II
for this purpose wero at first scattered about tfie vanous
streets, but vrere eventually confined to one quarter, and
formed the public moat market. This market, in the .time
of Nero, was one of the most imposing structures in the
city, and some idea of its magnificence has been transmitted
to us by a delineation of it preserved on an ancient coin.
As the policy .tnd customs of the Romans made themselves
felt ill Gaul, the Roman system of abattoirs, if it may bo
BO called, was introduced there in an imperfect form. A
clique of families in .Paris long exercised the special func-
tion of catering for the public wants in respect of meat
But as the city increased in magnitude and population, the
necessity of keeping slaughter-houses as much as possible
apart from dwelliug-houses became apparent. As early as
the time of Charles IX., the attention of the French author-
ities was directed to the subject, as is testified by a decree
passed on tht 25th of February 1567. But although the
importance of the question was frequently recognised, no
definite or decided step seems to have been taken to effect
the contemplated reform until the time of Napoleon L
The evil had then reached a terribly aggravated form.
Slaughter-houses abutted on many of the principal thorough-
fares ; the traffic was impeded by the constant arrival of
foot-sore beasts, whose piteous cries pained the ear; and
rivulets of blood were to be seen in the gutters of the public
streets. The constant accumulation of putrid offal tainted
the atmosphere, and the Seine was polluted by being used
as a common receptacle for slaughter-house refuse. This
condition of things could not be allowed to continue, and
on the 9th of February 1810, a decree was passed authoris-
ing the construction of abattoirs in the outskirts of Paris,
and appointing a Commission, to which was committed the
consideration of the entire question.
The result of the appointment of this Commission was
the construction of the five existing abattoirs, which were
formaUy opened for business on the 15 th of September
1818. The Montmartre abattoir occupies 8J English acres;
illHlllUMUlllVJll
rTTTTTTTm
I I I I iSl I 1 I I
rrm-Td n~n
■ ■■■'■*'''■'
I I i I I I.' ■ I
S^I-S
S?, ' &
I » 1 I 1,1 I I I I 1
I ■ ' ' "^ ■ ' ■ ' '
— 1 I —
:~
S4i
>5
— 1 •—
— J 1— .
■ ■
t —
t ^5? , r-M 1
' ' ■ ' ' ^ ' ■ ' '
1. MenilmoDtant Abattoir.
A. Residence of OfBcUls.
B. Sheep and Cattle Shedi
C. Slaujfttter-Hoasea.
D. Yards to do.
E. Stored.
F. Tallow-meUing Hotiaca.
G. Steam Enefne.
n. Stable witti Water TankJ.
above.
I. Dane Pits.
L. Priviea
M. Layers for Cattle!
M^nilmontant, lOJ acres; Crenelle, 7| ; Du Eoule, 5|;
md Villejuif, 5i. The first two contain each 64 slaughter-
houses and the same number of cattle-sheds ; the third, 48 ;
and each of the others 32. The dimensions of each of the
slaughter-houses is about 29i feet by 13. The general
arrangement of the abattoirs will be nnderstood fron. the
preceding plan of that of Mt^niknontant.
The component parts of a French abattoir are — 1
Echaudoirs, wnich is the name given by the Paris butcher
to the particular division allotted to him for the purpose of
knocking down his beasts ; 2. Bouveries et Bergeriti, the
places set apart for the animals waiting to be slaughtered,
where the animals, instead of being killed at once, after a
long and distressing journey, when their blood is heated and
their flesh inflamed, are allowed to cool and rest till the
body is restored to its normal healthy condition ; 3. Fan-
deurt, or boiling-down establishments ; and, 4. Triperits,
which are buildings set apart for the cleaning of the tripe
of bullocks, and the fat, heads, and tripe of sheep and
calves. Besides .these, a Paris abattoir contains Loyementt
des a gens, Magasina, Rhervoirs, Voiries, Lieux d'aisance,
Voules, RemUes et ecuries, Para aux Boeu/s, &c., and is
provided with an abundant supply of .water. All the abatr
toirs are under the control of the municipal authoriJies,
and frequent inspections are made by persons regularly
appointed for that purpose.
The abattoirs are situated within the barriers, each at a
distance of about a mile and tliree-quarters from the heart
of the city, in districts whereuuman habitations are still
comparatively few. There are two principal markets from
which the abattoirs at Paris are supplied, — the one at
Poissy, about 13 miles to the north-west, and the other at
Sceaux, about 5 miles and a quarter to the south of the
city. There are also two markets for cows and calves,
n.^mely, La Chapelle and Lcs Bemadins.
The Paris abattoirs were until recently the most perfect
specimens of their class ; and even now, although in some
of their details they have been surpassed by the new
Islington meat market, for their complete and compact
arrangement they remain unrivalled.
The example set by Paris in this matter has been fol-
lowed in a more or less modified form by most of the prin-
cipal Continental towns, and the system of abattqjrs has
become almost imiversal in France.
The condition of London in this important sanitary
respect was for a long period little more endurable than
that of Paris before the adoption of its reformed system.
Smithfield market, situated in a very populous neighbour-
hood, continued till 1852 to be an abomination to the town
and a standing reproach to its authorities. No fewer than
243,537 cattle and 1,455,249 sheep were sold there in
1852, to be afterwards slaughtered in the crowded courts
and thoroughfares of the metropolis. But public opinion
at length forced the Legislature to interfere, and the corpora-
tion was compelled to abandon Smithfield market and to
provide a substitute for it elsewhere.
The site selected was in the suburb of Islington, and the
designs for the work were prepared by Mr Bunning. The
first stone was laid March 24, 1854, and the market was
opened by Prince Albert, June 15, 1855. The Islington
market is imdoubtedly the most perfect of its kind. It occu-
pies a space of some 20 acres on the high land near the Pen-
tonrille prison, and is open to both native and forei;rn cattle,
excepting beasts from foreign countries under quarantine.
In connection with the Islington cattle market are a few
slaughter-houses, half of which were originally public, and
half rented to private individuals ; but at present they are
all practically private, and the majority of the cattle sold
are driven away and kUled at private slaughter-houses. In
this respect the London system differs from that of Paris ;
and it may be said for the former that the meat is less
liable to be spoded by being carted to a distance, and is
therefore probably delivered in better condition ; but the
latter secures that great desideratum, the practical eitino-
tion of isolated slaughter-houses.
ABA ABA
The Edmburgh abattoir, erected in 1851 by the corpora-
tion, from designs prepared by Mr David Coiisin, the city
irchitect, > is the best as regards both construction and
management in the United Kingdom. It occupies an area
of four acres and a quarter, surrfiunded by a screen-wall,
from which, 'along the greater part of its length, the build-
-.r-s are aeoarated by a considerable open space. Opposite
1
iiiiiiitii
X
2, Edinburgh Slaughter-Houses.
B. SlaoKhterIng Booiha.
C CaUle ShcdB.
li. Enclosed Yards.
B. WaU.
P. Steam-j:.nglll&
G Raised Water Tank.
H. Tripery.
I. Pig-slaughterint: House.
K. Court for Cattle.
L. Sheda.
U. Blood Bouse, now Albumen Factory.
the principal gateway is a double row of buildings, extend-
ing in a straight line to about 376 feet in length, with a
Central roadway (marked AA in the annexed plan), 25 feet
«ride. There are three separate blocks of building on each
side of the roadway, the central one being 140 feet in
length, and the others 100 feet each — cross-roads 18 feet'
Tride separating the blocks. These ranges of building, as
well as" two smaller blocks that are placed transversely
behind the eastern central block, are divided into compart-
ments, numbering 42 in all, and all arranged on the same
plan. Next the roadway is the slaughtering-booth (BB), 18
feet by 24, and 20 feet in height, and behind this is a shed
(CC) 18 feet by 22, where the cattle are kept before being
slaughtered. AU the cattle are driven into these sheds by
a back-entrance, through the small enclosed yards (DD).
The large doors of the booths are hung by balance weights,
and slide up and down, so as to present no obstruction
either within the booth or outside. By a series of large
ventilators along the roof, and by other contrivances, the
slaughtering-booths are thoroughly ventilated. Great pre-
cautions have been used to keep rats out of the buildings.
To effect this, the booths are laid with thick well-dressed
pavement, resting on a stratum of concrete 12 inches
thick, and the walla, to the height of 7 feet, are formed of
solid ashlar; the roadways, too, are laid with concrete,
and causewayed with dressed whinstone pavement; and the
drainage consists entirely of glazed earthenware tubes.
The ground on which the abattoir is built was previously
connected with a distillery, and contains a well 100 feet
deep (E), which, with the extensive system of tunnels
attached to it, provides the establishment with an abundant
supply of pure water. By means of a steam-engine (F),
introduced in 1872, the water is pumped up into a raised
tank (G), whence it is distributed to tho different booths
and sheds, as well as for scouring the roadways and drains.
The steam from the engine is utilised in heating water for
the numerous cast-iron tanks required in the operations of
cleansing and dressing the tripery (H) and pig slaugh-.
tering-nou.se (I). By an ingenious arrangement of
rotary brushes driven by the steam-engine, — the inven-
tion of Mr. Rutherford, the superintendent, — the tripe is
dressed in a superior manner, and at greatly less cort
; than by the tediour and troublesome method o^ ''-ZTii-
cleaning.
By the Edinburgh Slaughter-Houses 'Act of I'SSO, the
management) is vested in the city authorities. Booths
are let at a statutory rent of £8 each per anntmi, and, in
addition to this, gate-dues are payable for every beast
entering the establishment. !^ The present rates for tenants
of booths are l^A for an ox or cow, |d. for a calf or
pig, and :Jd. for a sheep. Common booths are provided
for butchers who are not tenants, on payment of double
gate-dues. The city claims the blood, gut, and manure.
■ The tripe and feet are dressedjfor the trade without extra
charge.
The blood was formerly collected in large casks, and dis-
posed of for manufacturing purposes. This necessitated
the storage of it for several days, causing in warm weather
a very offensive effluvium. It even happened at times,
when there was little demand for the commodity, that
the blood had to be sent down the drains. All nuisance
is now avoided, and the amount received annually for
the blood has risen from between £200 and £450 to
from £800 to £1200, by a contract into which Messrs
Smith and Forrest of ilanchester have entered with
the city authorities, to take over the whole blood at
a fixed price per beast. They have erected extensive
premises and apparattLS at their own cost, for extracting
from tho blood the albumen, for which there is great
demand in calico-nrinting, and for converting the clct into
manure.
In connection with the establishment is a boiling-house,
where all meat unfit for human food is boUed down and
destroyed, Tho number of carcases seized by the inspec-
tor, and sent to the boiling-house, during the 5^ years
ending with the clos.e of 1872, amounted to 1449, giving
a weight of upwards of 400,000 pounds.
Before the erection of these buildings, private slaughter-
houses were scattered all over the city, often in the most
populous districts, where, through want of drainage and
imperfect ventilation, they contaminated the whole neigh-
bourhood. Since the opening of the public abattoir, all
private slaughtering, in the city or within a mile of it, is
strictly prohibited.
Few of the provincial towns in Great Britain have as yet
followed the example of London and EdinburgL In some
instances improvements on the old system have been
adopted, but Great Britain is still not orily far behind her
foreign neighbours in respect of abattoirs, but has even
been excelled by some of her own dependencies. In
America abattoirs are numerous, and at Calcutta and other
towns in British India, the meat markets present a very
creditable appearance from their cleanliness and systematic
arrangement. (c. N. B.)
ABAUZIT, FlEMiN, a learned Frenchman, was born
of Protestant parents at Uzis, in Languedoc; in 1679.
His father, who was of Arabian descent, died when he
was but two years of age ; and when, on the revocation
of the Edict of Nantes in 1685, the authorities took steps
to have him educated in the Roman Catholic faith, hi«
mother contrived his escape. For two years his brother
and he lived as fugitives in the mountains of the Cevennoa,
but they at last reached Geneva, where their mother after-
wards joined them on escaping from the imprisonment in
which she was held from the time of their flight. Abauzlt'a
youth was spent in diligent sttidy, and at an early a;/c i:e
acquired great proficiency in languages, physics, and
theology. In 1698 he travelled into Holland, and there
became acquainted with" Bayle, Jurieu, and Basnage.
Proceeding to England, he was introduced to Sir J^^aao
Newton, who found in him one of the earliest defcvdera
of the great truths his discoveries disclcaed to (he -.vorld.
8
A B B — A B B
Sir Isaac corrected in the second edition of his Principia an
error pointed out by Abauzit. The high estimate Newton
entertained of his merits appears from the compliment
he paid to Abauzit, when, sending him the Commercium
EpUtolwum, ho said, " You are well worthy to judge
between Leibnitz and me." The reputation of Abauzit
induced William III. to request him to settle in England,
but ho did not accept the king's offer, preferring to return
to Geneva. There from 1715 he rendered valuable assistance
to a society that had been formed for translating the New
Testament into French. Ho declined the oiler of the
chair of philosophy in the University in 1723, but ac-
cepted, in 1727, the sinecure office of librarian to the city
Df his adoption. Hero he died at a good old ago, in 1707.
Abauzit was a man of great learning and of wonderful
versatility. The varied knowledge he possessed wan so
well digested and arranged in his retentive mind as to be
always within his reach for immediate use. Whatever
chanced to bo discussed, it used to bo said of Abauzit, as
of Professor WhewcU of our own times, that ho seemed to
have made it a subject of particular study. Eousseau,
who was jealously sparing of his praises, addressed to
him, in his NouvelU Ilelohe, a fine pancgjTic ; and when a
stranger flatteringly told Voltaire he had come to see a great
Little remains of the lalxmrs of this intellectual giant, his
heirs having, it is said, destroyed the papers that came into
their possession, because their religious opinions differed
from those of Abauzit. A few theological, archaeological,
and astronomical articles from his pen appeared in the
Journal Hdvetique and elsewhere, and he contributed
several papers to Rousseau's Dictionary of Music. A
work ho wrote throwing doubt on the canonical authority
of the Apocalypse was answered — conclusively, as Abauzit
himself allowed — by Dr Leonard Twells. He edited, and
collection of his wr'^ings was published at Geneva in
1770, and another at London in 1773. Some of them
(vere translated into English by Dr Harwood (1770, 1774).
Information regarding Abauzit will be found in Senebier's
Ilistoire Litteraire de Gaieve, Harwood's Miscellanies, and
Orme's JBibllotheca Biblica, 1834.
ABB, a town of Yemen in Arabia, situated on a moun-
tain in the midst of a very fertile covintry, 73 miles N.E.
of Mocha. Lat. 13° 58' N., long. 44° 15' E. It contains
about 800 houses, and is surrounded by a strong waU ;
the streets are veil paved ; and an aqueduct from a neigh-
bouring mountain supplies it with water, which is received
in a reservoir in front of the crincipal mosque. The
ABBADJE, JjVJIEs, an eminent Protestant divine,
was born- at Nay in Bern about 1657. His parents
were poor, but through the kindness of discerning friends,
he received an excellent education. He prosecuted his
studies with such success, that on completing his course
at Sedan, though only seventeen year." of age, he had con->
ferred on him the degree of doctor in theology. After
spending some years iu Berlin as minister of a French
Protestant church, ho accompanied Marshal Schomberg,
in 1683, to England, and became minister of the French
church in the Savoy, London. His strong attachment to
the cause of King Wdliam appears in his elaborate
defence of the Revolution, as well as in his history of
the conspiracy of 1696, the materials of which were
furnished,- it is said, by the s-.cretarics of state. The
king promoted him to the deanery of KUlaloe in Ireland.
He died in London in 1727. Abbaciie was a man of
great ability and an eloquent prcach'.r, but is best known
by his religious treatises, several of wuich were translated
from the original French into other languages, and had a
wide ciiculation all over Europe. The most important of
these are Traite de la Verite de la Jieligion Chrilienne ;
its continuation, Traite de la Diviniti de Jisus-Chriit ;
and L'Art de se connaitre Soyviime.
ABBAS I., surnamed Tat: Gheat, one of tht most
celebrated of the sovereigns of Persia, was the youngest
son of Shah Jlohammed Khodabendch. After heading a
successful rebellion against liis father, and causing one of
his brothers (or, as some say, both) to be aissassiiatcd, he
obiaiucd possession of the throne at the early ago of
eighteen (1580). Determined to raise the fallen fortunes
of hii counti-y, he first directed his efforts against the
predate y Uzbeks, who occupied and harassed Khorasan.
After a long and severe struggle, he defeated them in a
great battle near Herat (1597), and drove thcri out of his
dominions. In the wars he carried on with the Turks
during nearly the whole of his reign, hia successes were
numerous, and ho acquired or regained a large extent of
territory. By the victory he gained at Bassorah (1605),
he extended his empire beyond the Euphrates; A chimed L
was forced to code Shinvan and Kurdistan in 1611 ; the
united armies of the Turks and Tartars were completely
defeated near Sultanieh in 1C18, and Abbas made peace
on very favourable terms; and on theTurks renewing tliewar,
Baghdad fell into his hands after a year's siege (1623).
In the same year ho took the island of Ormuz from the
Portuguese, by the assistance of the BritisK When ho died
in 1C28, his dominions reached from the Tigris to the Indus.
Abbas distinguished himself, not only by his successes
in arms, and by the magnificence of his court, but also by
his reforms iu the administration of his kingdom. He
encouraged commerce, and, by constructing h'ghways and
building bridges, did much to facilitate it. To foreigners,
especially Christians, ho showed a spirit of tolerance ; two
Englishmen, Sir Anthony and Sir Robert Shirley, were
influence over him. His fame is tarnished, however, by
numerous deeds of tyranny and cruelty. His own famOy,
especially, suffered fromlliis fits of jealousy; his eldest son
was slain, and the eyes of his other children were put out,
by his orders.
ABBAS MIRZA (6. 1785, d. 183?), Prince of Persia,
third sen of the Shah Feth Ali, was destined by his father
to succeed him in the government, because of his mother's
connection with the royal tribe of the Khadjars. Ha led
various expeditions against the Russians, but generally
^-ithout success (1803, 1813, 1826). By a treaty made
between Russia and Persia in 1828, the right of Abbas
to the succession was recognised. When the Russian
deputies were murdered by the Persian populace in 1829,
Abbas was sent to St Petersburg, where he received a
hearty welcome from the Czar, and made himself a
favourite by his courtesy and literary taste. He formed a
design against Herat, but died shortly after the siege had
been opened by his son, who succeeded Feth Ali as the
Shah Mohammed Mirza. He was truthful^a rare quality
iu an Eastern — plain in di-ess and stylb of living, and fond
of literature.
ABBASSIDES, the caliphs of Baghdad, the most
famous flynasty of the sovereigns of the Mahometan or
Saracen empire. They derived their name and descent
from Abbas (b. 566, d. 652 a.d.), the uncle and adviser of
Maiomet, and succeeded the dynasty of the Ommiads, th«
caliphs of Damascus. Early in the 8th century the
famij/ of Abbas had acquired great influence from their
near relationship to the Prophet ; and Ibrahim, the fourth
in descent from Abbas, supported by the province of
Khorasan, obtained several successes over the Ommiad
armies, but was captured and put to death by the Caliph
Merwan (747). Ibrahim's brother, Abul-Abbn.s. whom ie
A B 13 — A B B
had named his heir, assumed the title of caliph, and, by a
decisive victory near the river Zab (750), effected the over-
throw of the Ommiad dynasty. Merwan fled to Egypt,
but was pursued and put to death, and the vanquished
family was treated with a severity which gained for Abul-
Abbas the surname of Al-Safiah, the Blood-ahedder.
From this time the house of Abbas was fully established
in the government, but the Spanish provinces were lost to
the empire by the erection of an independent caliphate of
Cordova, under Abderrahman.
On the death of Abul-Abbas, Almansur succeeded to
the throne, and founded Baghdad as the seat of empire.
He and his son llohdi waged war successfully against the
Turkomans and Greeks of Asia Minor; but from this time
the rule of the Abbassides is marked rather by the
development of the liberal arts than by extension of
territory. The strictness of 'the Mohammedan religion was
- relaxed, and the faithful yielded to the seductions of luxury.
The caliphs Harun Al-Rashid (786-809) and Al-Mamun
,(813-833) attained a worId--iride celebrity by their gorgeous
palaces, their vast treasures, and their brilliant and nume-
rous equipages, in all which their splendour contrasted
strikingly with the poverty of European sovereigns. The
former is known as one of the heroes of the Arabian
_ Nights ; the latter more worthily stiU as a liberal patron
of literature and science. It 15 a mistake, however, to
look in the rule of these caliphs for the lenity of modern
civilisation. " No Christian government," says HaUam,
" except perhaps that of Constantinople, exhibits such a
series of tyrants as the caliphs of Baghdad, if deeds of
blood, wrought through unbridled passion or jealous
policy, may challenge tJie name of tyranny."
The territory of the Abbassides soon suffered dismem-
berment, and their power began to decay. Eival sove-
reignties (Ashlabites, Edrisites, itc.) arose in Africa, and
an independent government was constituted in Khorasan
(820), under the Taherites. In the West, again, the Greeks
encroached upon the possessions of the Saracens in Asia
Minor. Ruin, however, came from a less civilised race. The
caliphs had continually been waging war with the Tartar
_ hordes of Turkestan, and many captives taken in these wars
•were- dispersed throughout the empire. Attrec'.ed by their
bravery and fearing rebeUion among his subjecJs, Motassera
(833-842), the founder of Samarah, and successful oppo-
nent of the Grecian forces under Theophilus, formed body-
guards of the Turkish prisoners, who became from that
time the real governors of the Saracen empire. Mota-
wakkel, son of Moto.s3em, was assassinated by them in the
palace (861) ; and succeeding caliphs became mere puppets
in their hands. Radhi (934-941) was compelled by the
disorganised condition of his kingdom to delegate to
Mohammed ben Rayek (936 a.d.), under the title of Emir-
al-Omara, commander of the commanders, the government
of the army and the other functions of the caliphate.
Province after province proclaimed itself independent ;
the caliph's, rule became narrowed to Baghdad and its
vicinity ; and the house of 'Abbas lost its power in the
East for ever, when Hulagu, prince of the Mongols, set
Baghdad on fire, and slew Motassem, the reigning caliph
(20th Feb. 1258). The Abbassides continued to hold a
semblance of power in the merely nominal caUphato of
Egypt, and feebly attempted to recover their ancient seat.
The last of them, ilotawakkel III., was taken by Sultan
Selim I., the conqueror of Egj-pt, to Constantinople, and
detained ther^ for some time as a prisoner. He afterwards
l-eturned to Egypt, and died at Cairo a pensionary of the
Ottoman government, in 1538.
ABBE is the French word corresponding to Abbot, but,
from .the middle of the sixteenth century to the time of
S,he French Ilcvolution, the term had a wider application.
xne assumption by a numerous class of the name and
style of abb6 appears to have originated in the right con-
ceded to the King of France, by a concordat between Pope
Leo X. and Francis I., to appoint ahbes commendatairei to
225 abbeys, that is, to most of the abbeys in France.
This kind of appointment, whereby the living was com-
mended to some one till a proper election could take
place, though ostensibly provisional, reaUy put the nomi-
nee in full and permanent possession of the benefice.
but had no share in its government, the charge of the
house being intrusted to a resident officer, the priea'
daustral. The ahhes commendalaires were not necessarily
priests ; the papal bull required indeed that they should
fake orders within a stated time after their appointment,
but there seems to have been no -.lifficulty in procuring
relief from that obligation. The , expectation of obtaining
these sinecures drew young men towards the Church in
considerable numbers, and the class of abb^s so formed —
abbes de cour they were sometimes called, and sometimes
(ironically) abbts de sainte esperance, abb^s of St Hope —
came to hold a recognised position, that perhaps proved as
great an attraction as the hope of preferment. The con-
nection many of them had with the Church was of the
slenderest kind, consisting mainly in adopting the name
of abb^, after a remarkably moderate course of theo-
logical study ; practising celibacy ; and wearing a distinc-
tive dress — a short dark -violet coat with narrow coUar.
Being men of presumed learning and undoubted leisure,
many of the class found admission to the houses of the
French nobility .is tutors or advisers. Nearly every great
family had its abbd. As might be imagined from the
objectless sort of life the class led, many of the abb& were
of indifferent character ; but there are not a few instaijices
of abb& attaining eminence, both in political life and in
the waits of literature and science. The Abbe Siey^s may
be taken as a prominent example of the latter type.
ABBEOKUTA, or .jIbeokuta, a town of West Africa
in the Yoruba Country, situated in N. lat. 7° 8', and
E. long, y 25', on the Ogun River, about 50 miles north
of Lagos, in a direct line, or 81 miles by water. It lies
in a beautiful and fertile country, the surface of which is
broken by masses of grey granite. Like most African
towns, Abbeokuta is spread over an extensive area, being
surrounded by mud walls, 13 miles in extent. The houses
are also of mud, and the streets mostly narrow and
filthy. There are numerous markets in which native pro-
ducts and articles of European manufacture are exposed
for sale. Palm-oil and sh'ea,-butter are the chief articles of
export, and it is expected that the cotton of the country
will become a valuable article of commerce. The slave
trade and human sacrifices have been abolished ; but not-
withstanding the efforts of English and American mission-
aries, the natives are stUl idle and degraded. The state
called Egbaland, of which Abbeokuta is the capital,
has an area of about 3000 square miles. Its progress has
been much hindered by frequent wars with the king of
Dahomey. Population of the town, about 150,000; of the
state or adjacent territory, 50,000. (See Burton's Abheo-
kuta and the Cameroon Mountains, 2 vols.)
ABBESS, the female superior of an abbey or convent
of nuns. The mode of election, position, rights, and
aiithority of an abbess, correspond generally with those
of an abbot. The office was elective, the choicfi being by
the secret votes of the sisters from their own body. The
abbess was solemnly admitted to her office by episcopal
benediction, together with the conferring of a staff and
pectoral, and held it for life, though liable to be deprived
for misconduct. The Council of Trent fixes the qualifyin|
age at forty, with eight years of profession." Abbesses had
I. a
10
A B B — A B B
a right to demand absolute obedience of their nuns, over
whom thoy exercised discipline, extending even to the
power of expulsion, subject, however, to the bishop. As
a female an abbess was incapable of performing the
spiritual functions of the priesthood belonging to an
abbot. She could not ordain, confer the veil, nor excom-
municate. In the eighth century abbesses were censured
for usurping priestly powers by presuming to give the
veil to virgins, and to confer benediction and imposition
of hands on men. In England they attended ecclesiastical
councils, e.g. that of Becanficld in C94, where they signed
before the presbyters.
By Celtic usage abbesses presided over joint-houses of
monks and nuns. This custom accompanied Celtic nioi;-
ostie missions to France and Spain, and even to Rome
itself. At a later period, a.d. 1115, Robert, the founder
of Fonto^Taud, committed the government of the whole
order, men as well as women, to a female superior.
Marteno asserts that abbesses formerly confessed nuns,
but that their undue inquisitiveness rendered it necessary
to forbid the practice.
The dress of an English abbess of the 12th century
consisted of a long white tunic with close sleeves, and a
black overcoat as long as the tunic, with largo and loose
sleeves, the hood covering the head completely. The
secular habits, and there was little to distinguish them
from their lay sisters. (e. v.)
ABBETILLE, a city of France, in the department of
the Somme, is situated on the Fiivcr Somme, 12 miles
from its mouth in the English Channel, and 25 miles
•N.W. of Amiens. It lies in a pleasant and fertile valley,
and is built partly on an island, and partly on both sides
of the river. The streets are narrow, and the houses are
mostly picturesque old structures, built of wood, with
many quaint decaying gables and dark archways. The
town is strongly fortified on Vauban's system. It ha? a
tribunal and chamber of commerce. The most remarkable
edifice is the Church of St Wolfran, which was erected in
the time of Louis XIL Although the original design was
not completed, enough was built to give a good idea of
the splendid structure it was intended to erect. The
facade is a magnificent specimen of the flamboyant Gothic
style, and is adorned by rich tracery, while the western
front is flanked by two Gothic towers. A cloth manufac-
tory wa.s established here by Van Robais, a Dutchman,
under the patronage of the minister Colbert, as early as
16C9 ; and since that time Abbeville has contin-ieJ to be
one of the most thriving manufacturing towns in France.
Besides black cloths of the best quality, there are produced
velvets, cottons, linens, serges, sackings, hosiery, pack-
thread, jewellery, eoap, and glass-wares. It has also
establishments for spinning wool, print-works, bleaching-
works, tanneries, a paper manufactory, die. ; and being
situated in the centre of a populous district, it has a con-
siderable trade with the surrounding country. .Vessels of
from 200 to 300 tons come up to the town at high-water.
Abbeville is a station on the Northern Railway, and is also
connected with Paris and Belgium by canals. Fossil
remains of gigantic mammalia now extinct, as well as the
rude flint weapons of pre-historic man, have been dis-
covered in the geological deposits of the neighbourhood.
A treaty was concluded here in 1259 between Henry
TTT of England and Louis IX. of France, by which the
prtjvince of Guienne was ceded to the English. PoDula-
tion, 20,058.
ABBEY, a monastery, or conventual establishment,
under the government of an abbot or an abbess. A
priory oidy differed from an abbey in that the superior
V)ure the name of prior instead of abbot. This was the
case m all the English conventual cathedrals, e.g., Cantflr-
buiy, Ely, Nor\vich, kc, where the archbishop or bishop
occupied the abbot's place, the superior of the moiia-stery
being termed prior. Other priories were originally off-
shoots from the larger abbeys, to the abbots of which they
continued subordinate ; but in later times the actual dis-
tinction between abbeys and priories was lost.
Reserving for the article iloNASTicisM the history of the
rise and progress of the monastic system, its objects, benefits,
evils, its decline and fall, we propose in this article to con-
fine ourselves to the structural plan and arrangement of
conventual establishments, and a description of the various
buildings of which these vast piles were composed.
The earliest Christian monastic communities ivith which Cell*
we are acquainted consisted of groups of cells or huts
collected about a common centre, which was usually tho
abode of some anchorite celebrated for superior holiness or
singular asceticism, but vi'ithout any attempt at orderly
arrangement. The formation of such communities in tho
East docs not date from the introduction of Christianity.
and' the Therapeutse in Egypt, who may be considered tho
prototypes of the industrial and meditative communities of
monks.
In the earliest age of Christian monasticism the a-sceties
were accustomed to live singly, independent of one another,
at no great distance from somo village, supporting them-
selves by the labour of their own hands, and distributing
the surplus after the supply of their own scantj- wants to
the poor. Increasing rehgious fervour, aided by persecu-
tion, di'ove them further and further away from the abodes
of men into mountain solitudes or lonely deserts. The
deserts of Egypt swarmed with the cells or huts of theso
anchorites. Antony, who had retired to the Egj-ptiau
Thebaid during the persecution of JIaximin, a.d. 312, was
the most celebrated among them for his austerities, his
sanctity, and his power as an exorcist. His iame collected
round him a host of followers, emulous of his sanctity.
The deeper he withdrew into tA wilderness, the more
numerous his di.sciplca became. They refused to be sepa-
rated from him, and built their cells round that of their
spiritual father. Thus arose the first monastic commnnjtYj
consisting of anchorites living eai.'h in his own little dwell-
ing, united together under one superior. Antony, as
Neander remarks (Church History, vuL iiL p. 31G, Clark's
Trans.), " without any onscious design of his own, had
become the founder of n new mode cf living in common,
CcSDobitisra." By degrees order was introduced in the
groups of huts. They were arranged in lines like the tents
in an encampment, or the house.i in a street. From this
arrangement these lines of single cells lame to be known
as Laurae, Aavpai, " street's" or '' lanes."
The real founder of coenobian monasteries in ti.e moflern Cdnobta
sense was Pachomius, an Egyptian of the beginning of the
4th century. The first community established bj him was
at Tabennie, an island of the. Nile in Upper Ej.'ypt. Eight
others were founded in his lifetime, numbering 1000 monks.
Within 50 years from his death his societies cculd reckob
50,000 members. These coenobia resembled villages, peopled
b'- a hard-working religious community, all of one sex.
The buildings were detached. sniaD, and of the humblest
character. Each cell or hut, according to Sozomen (H. E.
iii. 14), contained three monks. They took their chief
meal in a common refectory at 3 p.sf., up to which hour
they usually fasted. They ate in silence, with hoods ao
drawn over their faces that they could see nothing but what
was on the table before them. The monks spent aU thft
time, not devoted to religious services or study, in manual
labour. PaUadius, who -visited the Egyptian monasteries
about the close of the 4th century, foancf among tbc 300
ABBEY
11
Banta
Laiira,
members of the Ccenobimn of Panopolis, ^der the
Pachomian rule, 15 tailors, 7 smiths, 4 carpenters, 12
camel-drivers, and 15 tanners. Each separate coromunity
had its' own ceconomns, or steward, who was subject to
in chief ceconomus stationed at the head estabhshment. AU
the produce of the monks' labour was- committed to him,
and by him shipped to Alexandria. The money idised by
the sale was expended in the purchase of stores for the
support of the communities, and what was over was devoted
to charity. Twice in the year the superiors of the S2veral
coenobia met at the chief monastery, under the presidency
of an Archimandrite (" the chief of the fold," from /idvS-ia, a
fold), and at the last meeting gave in reports of their
The ccenobia of Syria belonged to tiie Pachomian institu-
tion. We learn many detaUs concerning those in the
,V;cinity of Antioch from Chrysostom's writings. The
monks lived in separate huts, KoAv/Sat, forming a religious
hamlet on the mountain side. They were subject to an
abbot, and observed a common rule. (They had no refec-
tory, but ate their common meal, of bread and water only,
when the day's labour was over, reclining on strewn grass,
Bometimes out of doors.) Four times in the day they
joined in prayers and psahns^
The necessity for defence from hostile attacks, economy
of space, and convenience of access from one part of the
community to another, by degrees dictated a more compact
and orderly arrangement of the buildings of a monastic
ooenobium. Large piles of • building were erected, with
strong outside waUs, capable of resisting the assaults of an
enemy, within which all the necessary edifices were ranged
Vound one or more open courts, usually surrounded with
cloisters. ; The usual Eastern arrangement is exemplified
i.n the plan 6t the convent of Santa Laura, Mt. Athos
(Laura, the designation of a monastery generally, being
- converted into a female saint).
K. Gatevray.
B. Chapela.
C. Gucst-liuirse.
D. Church.
E. Cloister.
F. Fountain.
G. Refectory
H. Kitchen.
L CeUs.
^. Storehouses.
L. Postern Gate.
U. Toner.
Monasteiy of ^anta Latira, Moui«t Athos (Lenoir).
^ITiis monastery, like the Oriental monasteries generally
<8 surrounded by a strong and lofty blank stone wall,
enclosing an area, of betv;een 3 and 4 acrea The longer
jide. extends to a length of about 500 feet. . There is only
one main entrance, tm the north side (A), defended by
three separate iron doors. Near the entrance is a large
tower (M), a constant feature in the monasteries of the
Levant. ■ ■ There is a small postern gate at (L.) The
enceinte comprises two large open courts, gniroundeS with
buildings connected with cloister galleries of wood or stone.
The outer court, which is much the larger, contains the
granaries and storehouses (K), and the kitchen (H), and
other offices connected with the refectory (G). Imme-
diately adjacent to the gateway is a two-storeyed guest-
hfluse, opening from a cloister (C). The inner court is
surrounded by a cloister (EE), from which open the monks'
cells (II). In the centre of this court stands the cathoUcon
or conventual church, a square building with an apse of
the cruciform domical Byzantine type, approached by a
domed narthex. In front of the church stands a marble
fountain (F), covered by a dome supported on columns.
Opening from the western side of the cloister, but actually
standing in the outer court, is the refectory (G), a large
cruciform building, about 100 feet each way, decorated
within with frescoes of saints. At the upper end is a semi-
circular recess, recalling the Triclinium of the Lateran
Palace at Kome, in which is placed the seat of the Iltgu-
menos or abbot. This apartment is chiefly used as a hall
of meeting, the Oriental monks usually taking their meals
in their separate cells. St Laura is exceeded in magnitude
by the Convent of Vatopede, also on Mount Athos. This '.'atopede
enormous establishment covers at least 4 acres' of ground,
and contains so many separate buildings within its massive
walls that it resembles a fortified town. It lodges above
300 monks, and the establishment of the Hegumenos is
described as resembling the cqurt of a petty sovereign
prince. The immense refectory, of the same cruciform
shape as that of St Laura. wiU accommodate 500 guests at
its 24 marble tables.
The annexed plan of a Coptic monastery, from Lenoir
shows us a church of three
aisles, with cellular apses, and
two ranges of cells on either
side of an oblong gallery.
Monasticism in the West
owes its extension and de-
velopment to Benedict of
Nursia (bom a.d. 480). His
rule was diffused with miracul-
ous rapidity from the parent
foundation on Monte Cassino
through the whole of Western
Europe, and every country wit-
nessed the erection of monas-
teries far exceeding anything
that had. yet been seen in spaci-'
ousnesa and splendour. Few
great towns in Italy were without their Benedictine convent, Bc-nedie^
and they quickly rose in all the great centres of population in tine.
England, France, and Spain. The number of these monas-'
teries founded between A.D. 620 and 700 is amazing.
Before the Councd of Constance, a.d. 1415, no fewer than
15,070 abbeys had been established of this order alone.
The Benedictine rule, spreading with the vigour of a young
and powerful Hfe, absorbed into itself the older monastic
foundations, whose discipline had too usually become dis-
gracefully relaxed. In the words of Milman {Latin
Christiani1y,-^o\. i p. 425, note x.), "The Benedictine
rule was universally received, even in the older monas-
teries of Gaul, Britain, Spain, and throughout the West,'
not as that of a rival order (all rivaliy 'was of later
date), but- IV a more full and perfect rule of the monas-
tic life." Not only, therefore, were ' new oionasterics
founded, but tho.se already existing wire pulled down,
and rebuilt to adapt them to the requirements of ths
pew rule.
The buildings of a Benedictine abbey were uniformly
arranged aftar ono plan, modified where necessary (as at.
Plan of Coptic Monastery,
A Karthex.
B. Church.
C. Corridor, with cello on each sido.
D. staircase.
12
ABBEY
[bkkedictine.
St Call,
Durham and Worcester, whore the monasteries stand close
to the steep bank of a river), to accommodate the arrange-
ment to local circumstances.
Wo have no existing examples of the earlier monasteries
of the Benedictine order. They have all yielded to the
ravages of time and the violence of man. But we have
fortunately preserved to us an elaborate plan of the great
Swiss monastery of St Gall, erected about A.D. 820, which
puts us in possession of the whole arrangements of a
monastery of the first class towards the early part of the
9th century. This curious and interesting plan has been
made the siibject of a memoir both by Keller (Zurich,
1844) and by Professor Willis (Arch. Journal, 1848, vol.
7. pp. 8G-117). To the latter we are indebted for the
_^uj:eplbei]
c-ELj
Lj...j
n r-|
T r
N
hf
• 1 i
"T^^/r ""I'l"
1 1
1 1
U _J ' 1
f -!7 r^'i?
1
Ground-plan o( St Gall,-
CirTRCa.
FlBll Altar.
A lir of Si r.TiL
Altar of St I'cfcr.
Nnve.
. Towers.
of
MoKasTic BciLDiNoa.
O. Cloister.
H. Calefactory, wUh Dormltor)- rxT.
L Necessary.
J. Abbot's house
K. Rcfeotor/.
U Kltcheo.
U. Bakelioiuo and Brcwliouse.
N. CelJai.
O. Parlour.
P, Scrtptot lum. witli Mbraiy over.
Pj. Sacristy and Vestry.
Q. House of Novices— 1. Cbapcl; 2.
Refectory; 3. Calcfactoiy; 4.
I'ormltory; 6. Waster's Room;
6. Ctiambcrs.
B. Inflrmary— 1-6 as. above in the
House of Novicca
8. Doctor's House.
T. Phyolc Garden.
U. Houae for blood-lettlnd.
\'. School.
W. Scfaoolinnster's Lodpinps.
-\i.\|. Guest-house for those
suf-erlor rank.
XgXj. Guc&t-housc I'cr the poor.
Y. Guest-chamber for stronge tnonka.
Mk-mal Dkpakiuext.
Z. Factory.
a. Thr€3h:nr-f.oor.
6. Workshops.
t. e. .Mills.
d. Kiln.
e. Stablffi
/*. Cowsheds.
?. Goatsbeds.
A. ?'.g-st!cs. t. Sheep.folda.
*, *, t. Servar.ts' an-j workiuen's
sleeping chaiubeM
/. Gardener'a hoitso.
m, m. Hen and DucJl house,
n. Poaltry-keeper'a bouse.
o. Garden.
/I. Cemetery.
r. Unnamed in Plan.
J. t. a. Eltchena
t, 1. 1. Batha
Rubstance of the following description, as well as for the
above woodcut, reduced from his elucidated transcript of
the original preserved in the archives of the convent
The general appearance of the convent is that of a town of
isolated houses with streets running between them. It is
evidently planned in compliance with the Benedictine rule,
which enjoined that, if possible, the monastery should contain
within itself every necessary of life, as well as the build-
ings more intimately connected with the religious and
social life of its inmates. It should compi'se a mill, a
bakehouse, stables and cow-houses, together with accom-
modation for carrying on all necessary mechanical art*
within the walls, so as to obviate the necessity of the
monks going outside its limits. The general distribution
of the buildings may be thua described : — The church,
with its cloister to the south, occupies the centre of a
ings, as in all great monasteries, are distributed into
groups. The church forms the nucleus, as the centre of
the religiou-s life of the community. In closest connec-
tion with the church is the group of buildings appropriated
to the monastic life and its daily requirements — the refec-
tory for eating, the dormitory for sleeping, the common
room for social intercourse, the chapter-house for religious
and disciplinary conference. These essential elements^ of
monastic life are ranged about a cloister court, surrounded
by a covered arcade, affording communication sheltered from
the eltjments, between the various buildings. The infirmary
for sick monks, ■with the physician's house and physic gar-
den, lies' to the east. In the same group with the infirmary
is the school for the novices. The outer school, with its
head-master's house against the opposite wall of the church,
stanils outside the convent enclosure, in close proximity
CO the abbot's house, that he might have a constant eyo
nver them. The buildings devoted to hospitahty are divided
into three groups, — one for the reception of distinguished
guests, another for monks ■visiting the monaster}-, a third
for poor travellers and pilgrims. The first and third are
placed to the right and left of the common entrance of the
monastery, — the hospitium for distinguished guests being
placed on the north side of the church, not far from the ab-
bot's house; that for the poor on the south side next to the
farm buildings. The monks are lodged in a guest-house
built against the north ■n'all of the church. The group of
buildings connected ■with the material wants of the esta-
blishment is placed to the south and west of the church,
and is distinctly separated from the monastic buildings.
The kitchen, buttery, and offices, are reached by a passage
from the west end of the refectory, and are connected 'with
the bakehouse and brewhouse, ■nhich are placed still fur-
ther away. The ■R-hole of the southern and western tides
is devoted to workshops, stables, and farm-buildings. The
btuJdinga, -with some exceptions, seem to have been of one
story only, and all but the church were probably erected
of wooii The whole includes thirty-three separate blocks.
The church (D) is cruciform, with a nave of nine bays, and
a semicircular apse at either extremity. That to the west
is surrounded by a semicircular colonnade, leaving an open
'■ Paradise" (E) between it and the wall of the church.
The ■whole area is divided by screens into various chapels.
The high altar (A) stands immediately to the east of the
transept, or ritual choir; the altar of St Paul (B) in the
eastern, and that of St Peter (C) in the western apse. A
cylindrical campanile stands detached from the church on
either side of the western apse (FF\
The " cloister court ' (G) on the south side of the nave
of the church has on its east side the " pisalis" or " calefac-
tory" (H),the common sitting-room of the brethren, tvarmed
by flues beneath the floor. On this side in later monas-
teries we invariably find the chapter-house, the absence of
which in this plan is somewhat surprising. It appears,
however from the inscriptions on the plan itself, .that the
BENKDICIINE.J
ABBEY
13
north wait of the cloisters served for the purposes ot a chap-
ter-house, and was fitted up with benches on the long sides.
Above the calefactory is the " donnitory" opening into the
seiith transept of the church, to enable the monks to attend
the nocturnal services with readiness. A passage at the
other end leads to the " necessarium " (I), a portion of the
monastic buil'dings always planned with extreme care. The
southern side is occupied by the "refectory" (K), from the
west end of which by a vestibule the kitchen (L) is reached.
This is separated from the main buildings of the monastery,
and is connected by a long passage with a building containing
the bakehouse and brewhouse (M), and tho sleeping-rooms of
the servants. The upper story of the refectory is the "ves-
tiarium," where the ordinary clothes of the brethren were
kept On the western side of the cloister i? another two
story building (N). The cellar is below, and the larder and
store-room above. Between this building and the church,
opening by one door into the cloisters, and by another to the
outer part of the monastery area, is the " parlour" for inter-
views with visitors from the external world (O). On the
eastern side of the north transept is tho "scriptorium"
or writing-room (PJ, with the hbrary ahore.
To the east of the church stands a group of buildings
comprising two miniature conventual establishments, each
complete in itself. Each has a covered cloister surrounded
by the usual buildings, i.e., refectory, dormitory, &a, and
a church or chapel on one side, placed back to back. A
detached building belonging to each contains a bath and a
kitchen. One of these diminutive convents is appropriated
to the " oblati" or novices (Q), the other to the sick monks
as an "infirmary" (R).
The "residence of the physicians" (S) stands contiguous
lo the infirmary, and the physic garden (T) at the north-east
comer of the monastery. Besides other rooms, it contains
a drug store, and a chamber for those who are dangerously
ill. The " house for blood-letting and purging" adjoins it
on the west (U).
The "outer school," to the north of the convent area, con-
tains a large school-room divided across the middle by a
screen or partition, and surrounded by fourteen Little rooms,
termed the dwellings of the scholars. The head-master's
house (W) is opposite, built against the side wall of the
church. The two " hospitia" or "guest-houses" for tho
entertainment of strangers of difi'erent degrees (Xj Xj)
comprise a large common chamber or refectory in the
centre, surrounded by sleeping apartments. Each is pro-
vided with its own brewhouse and bakehouse, and that for
travellers of a superior order has a kitchen and store-room,
with bed-rooms for their sen'ants, and stables for their
horses. There is also an " hospitium" for strange monks,
abutting on the north wall of the church (Y).
Beyond the cloister, at the extreme verge of the con-
vent area to the south, stands the " factoi-y" (Z), contain-
ing workshops for shoemakers, saddlers (or shoem.'ikers,
tellarii), cutlers and grinders, trencher-makers, tanners, cur-
riers, fullers, smiths, and goldsmiths, with their dwellings
in the rear. On this side we also find the fann-buddings,
the large granary and threshing-floor (a), mills (c), malt-
house (d). Facing tho west are the stables (f), oi-sheds
(/), goat-stables (y), piggeries (A), sheep-folds (t), together
with the servants' and labourers' quarters (i). At the .south-
east corner we find the hen and duck house, and poultry-
yard (m), and the dwelling of the keeper (n). Hard by is
the kitchen garden (o), the beds bearing the names of the
vegetables growing in them, onions, garlic, celery, lettuces,
poppy, carrots, cabbages, &c., eighteen in all. In the same
way the physic garden presents the names of.'the medicinal
herbs, and the cemetery fp) those of the trees, apple, pear,
plum, quincfe, &c., planted there.
It is evident, from this most curious and valuable docu-
ment, that by the 9th century monastic estabusmnenta
ance, and were occupying a leading place in education,
agriculture, and the industrial arts. Tho influence such an
institution would difl'use through a wide district would be
no less beneficial than powerfui
The curious bird's eye view of Canterbury Cathedral and Canter-
its annexed conventual buildings, taken about 1 1 65, pre- bury,
served in the Great Psalter in the hbrary of Trinity College,
Cambridge, as elucidated by Professor Willis with such
admirable skill and accurate acquaintance with the existing
remains,' exhibits the plan of a great Benedictine monas-
tery in the 12th century, and enables us to compare it with
that of the 9th, as seen at St Gall. We see in both the
Sams general principles of arrangement, which indeed be-
long to all Benedictine monasteries, enabUng us to deter-
mine with precision the disposition of the various build-
ings, when Httle more than fragments of tho wall.? exist.
From some local reasons, however, the cloister and mcuiistio
buildings are placed on the north, instead, as is far more
commonly the case, on the south of the church. There
is also a senarate ch<ipter-house, v/hich is wanting at
St G-alL
The bmldings at Canterbury, as at St GaU, form separate
groups. The church forms the nucleus. In immediate con-
tact with this, on the north side, lie the cloister and the
group of buildings devoted to the monastic;, life. Outside
of these, to the west and east, are the "halls and chambers
devoted to the exercise of hospitality, with which every
monastery was proWded, for the purpose of receiving aa
guests persons who visited it, whether clergy or laity, tra-
vellers, pilgrims, or paupers." To the north a largo open
court divides the monastic from the menial buildings, in-
tentionally placed as remote as possible from the conven-
tual buildings proper, the stables, granaries, barn, bake-
house, brewhouse, laundries, &c., inhabited by the lay ser-
vants of the establishment. At the greatest possible distance
from the church, beyond the precinct of the convent, is
the eleemosynarj' department. The almonry for the relief of
the poor, with a great hall annexed, forms tho pauper's
hospitium.
The most important group of buildings is naturally that
devoted to monastic Ufe. This includes two cloisters, the
great cloister surrounded by the buddings essentially con-
nected with the daily hfe of the monks. — the church to the
south, the refectory or frater-house here as always on the
side opposite to the church, and furthest removed from it,
that no sound or smell of eating might penetrate its sacred
precincts, to the east the dormitorj-, raised on a vaulted
undercroft, and the chapter-house adjacent, and the lodg-
ings of the cellarer to the west. To this officer was com-
mitted tho provision of the monks' daily food, as well as
that of the guests. He was, therefore, appropriately lodged
in the immediate vicinity of the refectoiy and kitchen, and
close to the guest-halL A passage under the dormitory
leads eastwards to the smaller or infirmary cloister, approi
priated to the sick and infirm monks. Eastward of this
cloister extend the hall and chapel of the infirmary, resem-
bUng in form and arrangement the nave and chancel of an
aisled church. Beneath the dormitory, looking out into
the green court or herbarium, lies the "pisahs" or "cale-
factory," the common room of tho monks. At its north-
east corner access was given from the dormitory to the
necessarium, a portentous edifice in the form of a Norman
hall, 1 45 feet long by 25 broad, containing fifty-five scats. It
was, in common with all such ofllces in ancient monasteries,
constructed with the most careful regard to cleanliness and
' Tht Archileciural Uiilnry of Vie Conveillual Buildingi of Ou
Mmasltry of Christ Church in Canlmbury. By the Rev. Robert
WiUis. Printed for the Kent Aichaeologicii Society, 18G8.
14
ABBEY
Wwt-
minuter.
Jork
iicalth, a sticim of water running thrcugli it from end to ■
end. A second smuLler dormitory nins from eaat to west
for the accommoilatioa of the cunTentual officers, who were
bound to sleep in the dormitory. Close to the rck-ctory,
but outside the cloisters, aro the domestic offices connected
with it; to the north, the kitchen, 47 feet square, sur-
mounted by a lofty pyramidal roof, and the kitchen court;
to the west, the butteries, pantries, &c. The infirmary had
a small Idtchen of its own. Opposite the refectory door in
the cloister are two lavatories, an invariable adjunct to a
monastic dining-halJ, at which the monks washed before and
after taking food.
The buildings devoted to hospitality were divided into
three groups. The prior's group " entered at the south-east
angle of the green court, placed near the most sacred part
of the cathedral, as befitting the distinguished ecclesiastics or
nobility who were assigned to him." The cellarer's buildings,
wore near the west end of the nave, in which ordinary
visitors of the iaiddle class were hospitably entertained.
The inferior pilgrims and paupers were relegated to the
north hall or almonry, just within the gate, as far as possible
from the other two.
Westminster Abbey is another example of a great Bene-
dictine abbey, identical in its general arrangements, so far as
they can be traced, with those described above. The clois-
ter and monastic buildings lie to the south side of the church.
Parallel to the nave, on the south side of the cloister, was
the refectory, with its lavatory at the door. On the eastern
side we find the remains of the dormitory, raised on a
vaulted substructure, and communicating with the south
transept. The chapter-house opens out of the same alley
of the cloister. The small cloister lies 'to the south-east of
the larger cloister, and still farther to the east we have the
remains of the infirmary, with the table hall, the refectory
of those who were able to leave their chambers; The
abbot's house formed a small court-yard at the west
entrance, close to the inner gateway. Considerable por-
tions of this remain, including the abbot's parlour, cele-
brated as " the Jerjisalem Chamber," his hall, now used
for the Westminster King's scholars, and tho kitchen
and butteries beyond.
St Mary's Abbey, York, of -whichi the ground-plan is
ftnneSed", exhibits the usual Benedictine arrangements. The
precincts are surrounded by a strong fortified wall on three
sides, the river Ouse being sufficient protection on the
fourth side. The entrance was by a strong gateway (U)
to the north. Close to the entrance was a chapel, where ii
now the church of St Olaf (W), in which the new comers<paid.
their devotions immediately on their arrival Near the
gate to the south was the guest's-hall or hospitium (T).
The buildings are completely ruined, but enough remains
to enable us to identify the grand cruciform church (A),
the cloister-court 'with the chapter-house (B), the refectory
(I),^ the kitchen-court with its ofiices (K, O, O), and the
other principal apartmenta. _^ Tlve inSrmaiy has perished
completely.
Some Benedictine houses display exceptional arrange-
ments, dependent upon local circumstances, e.g. , the dormi-
tory of Worcester runs from east to west, from the west
walk of the cloister, and that of Durham is built orer the
west, instead of as usual, over the east waUf; but, as a
general rule, the arrangements deduced from the examples
described may be regarded as invariable
The history of Monasticism is one of alM^ate periods
of decay and revival With growth in popular esteem
came increase in material wealth, leading to luxury and
worldliness. ■ The first religious , ardcor cooled, the strict-
ness of the rule was relaxed, until'by the JOth century the"
dS'ty of discipline was so complete in France that the
TOoslrj are said to have been frequently, unacguaicted with
[
BENEDICTIKE.
the rule of St Benedict, and even iguorunt that thoy were
bound by any rule at all (Robertson's Church HifUyry,
ii. p. 538.) These alternations arc reflected in the mouaatio
buildings and the arraDgementii of the establishment
i
T? OfiitdMtut
St Mary's Abo-:), Y ork (Beneuictiiie). — Chuiton s Monastic RuliTK
0. Offices
P. fcllsni.
Q. UDcert&iD
R. Pft&sARe to Abbot'e Hona*. *
S.* Pasaage to Commoo lluiu&
•T. Hoipltliim.
U. Great Owe.
V. P.>rt«r"B Lodge.
W, Church or St Olaf.
S. Tower.
Y. Emnuice from Boottiaa
A. Clitirch.
B. ChapIer-bOQSe.
C. Vestibule to dn.
E. Library or ScrltHorlam.
F. Calefactory.
G. Necessary.
H. Parlour.
L Refectory.
K. Great Eitchcri and Conr^
L. Cellarer's Office.
If. Cellars.
N.. Passage tt Cloister.
The reformation oi thSse prevalent abuses generally took
the .form of the establishment of new monastic orders, with
^ew and more stringent rules, fequiring a modification of
the ^rchiteetural arrangements. • One of the earliest of
these reformed orders was the Cluniac. This order took Claanfv
its name from 'the little village of Clugny, 12 miles N.W
of Macon, near which, about a.d. ^09, a reformed Ben&,
dictine abbey was founded by William, Duke of Auvergne
under Bemo, abbot of Beaume. He was succeeded by
Odo, ■rtho is often regarded as the founder of the order.
The fame of Clugny spread far and wide. Its rigid rule
was adopted by a vast number of the old Benedictine alK
beys, who placed themselves in affiliation to the mother
society, while new foundations sprang up in large nimi-
bers, all owing allegiance to the " archabbot," established
at Clugny. By the end of the 12th century the number
of monasteries affiliated to Clugny Li the various coun-
tries of Western Europe amounted to 2000. The monas-
tic establishment of Clugny ■jras on6 of the most ertenaiva;
and magnificent in France. We may form some idea o£
its enormous dimensions from the fact recorded, that when,
A.D. 12i5, Pope Innocent rV;, accompanied .by twelve
c]
ABBEY
15
cardinals, a patriarch, three archbishops, the two generals
of the Carthusians and Cistercians, the king (St Louis),
und three of his sons, the queen mother, Baldwin, Count
of Flanders and Emperor of Constantinople, the Duke of
Burgundy, and six lords, visited the abbey, the whole
party, with their attendants, were lodged within the
monastery without disarranging the monks, 400 in num-
ber. Nearly the whole of the abbey buildings, including
the magnificent church, were swept away at the close of the
last century. \Vhen the annexed ground-plan was taken,
shortly before its destruction, nearly all the monastery, with
the exception of the church, had been rebuilt. The church,
the ground-plan of which bears a remarkable resemblance
to that of Lincoln Cathedral, was of vast dimensions. It
was 656 feet by 130 feet wide. The nave was 102 feet,
and the aisles 60 feet high. jL The nave (O) had double
Ahtey of Clugny, from VioUet le Due.
A. Gateway.
B. Narthex.
O. Choir.
D. HiKh-A)tar.
E. Retro.Altar,
F. Tomb of St nagh.
G. Nave.
H. Cloister.
K; Abbot's nome.
I* Guesc-neuBC.
M. Bakchoiuse.
N. At>bey Buildings,
0. Garden.
P. Kelectory.
vavdted aisles on either side. Like Lincoln, it tad an
eastern as well as a western transept, each furnished with
apsidal chapels to the east. The western transept was 213
feet long, and the eastern 123 feet. The choir terminated
in a semicircular apse (F), surrounded by five chapels, also
semicircular. The western entrance was approached by an
ante-church, or narthex{Ji), itself an aisled church of no mean
dimensions, flanked by two towers, rising from a stately
flight of steps bearing a large stone cross. , To the south
of the church lay the cloister-court (H), of immense size,
placed much further to the west than is usually the case.
On the south side of the cloister stood the refectory (P), an
immense building, 100 feet long and 60 feet wide, accommo-
dating six longitudinal and three transverse rows sf tables.
It was adorned with the portraits of the chief benefactors
of the abbey, and with Scriptural subjects. , The en^ wall
displayed the Last Judgment. ' Wo ire unhappily unable to
identify anyotherof the principal buLlding3(N). The abbot's
residence (K), still \-ra.rt,\y standing, adjoined the entrancc-
t'lito. The -guesl-house (L) Teas close by. .The bakehouse
(M), also remaining, is a detached ouuding of immense
.size. The first English house of the Cluniac order was that English
of Lewes, founded by the Earl of Warren, cir. a.d. 1077. Clunuc.
Of this only a few fragments of the domestic buildings exist.
The best preserved Cluniac houses in England are Castle
Acre, Norfolk, and Wenlock, in Shropshire. Ground-plans
of both are given in Brittou's Architectural Antiquities.
They show several departures from the Benedictine arrange-
ment. In each the prior's house is remarkably perfect,
AU Cluniac houses in England were French colonies, go-
verned by priors of that nation. They did not secure their
independence nor become " abbeys " till the reign of Henry
VI. The Cluniac revival, with all its brilliancy, was but
short lived. The celebrity of this, as of other orders,
^¥orked its moral ruin. With their gro^rth in wealth and
dignity the Cluniac foundations became as worldly in life
and as relaxed in discipline as their predecessors, and a
fresh refortu was needed. The next great monastic re-
vival, the Cistercian, arising in the last years of the lltK
centUi-', had a wider diffusion, and a longer and more
honourable existence. Owing its real origin, as a distinct
•foundation of reformed Benedictines; in the year 1098,
to a countryman of our own, Stephen Harding (a native of
Dorsetshire, educated in the monastery of Sherborne), and
deriving its name from Citeaux (Cistercium), a desolate
and ahuost inaccessible forest solitude, on the borders of
Champagne and Burgundy, the rapid growth and wide
celebrity of th? order is undoubtedJy to be attributed to
the enthusiastic piety of St Bernard, abbot of the first of
the monastic colonies, subsequently sent forth in such quick
successi'on by the first Cistercian houses, the far-famed
abbey of Claii-vaux (de Clara VaUe), A.D, lllG.
The rigid self-abnegation, which was the rulihg principle Cisterciau.
of this reformed congregation of the Benedictine order,
.extended itself to the churches and other buildings erected
by them. The characteristic of the Cistercian abbeys was
the extremest simplicity and a studied plainness. Only one
tower — a central one— ^was permitted, and that was to be very
low. Unnecessary pinnacles and turrets were prohibited.'
The triforium was omitted. The windows were to be plain
and undivided, and it was forbidden to decorate them with
stained glass. All needless ornament was proscribed. The
crosses must, be of wood; the candlesticks erf iron. The
reirunciation of the world was to be evidenced in all that
met the eye., The same spirit manifested itself in the
choice of the sites of their monasteries. . The more dismal,
the more savage, the more hopeless a spot appe'ared, the
more did it please their rigid mood. 'But they came not
merely as ascetics, but as improvers. The Cisterciau
monasteries are, as a rule,' found placed in deep weU-
watered valleys. They always stand on the border of a
stream; not rarely, as at Fountains, the buildings extend
over it. These vaDeys, now so rich and productive, wore a
very different aspect when the brethren first chose them as
the place of their retirement. Wide swamps, deep mo-
rasses, tangled thickets, wild impassable forests, were their
prevailing features. The ".^Bright Valley," Clnra Vallis of
St Bernard, was known as the " Valley of Wormwood,"
infamous as a den of robbers. " It was a savage .dreary
solitude,. ■ so utterly barren that at first Bernard and hia
companions were reduced to live on beech leaves." — ^Mil-
man's Lett. Christ. voL iii. p. 335.)
All Cistercian monasteries, unless the circumstances (tf
the localitj- forbade it, were arranged according to one plan.
TJxe? general arrangement and distribution of th^ various
" buildings, which went to make up one of thtso vastv-esta-
blishmcnts, may bo gathered from that of St Bernard's
own Abbey of Clairvaux, which is liere giren. Obirviui
It will be obsented that tlie abbey prfftiucts are surrounded
by a strong wall, furnished at internals^ with watch-
16
ABBEY
CISTERCUX
OAiiraui. towers and other dcfcnsiTe works. The wall ls nearly
encircled by a stream of water, artificially diverted from the
small riviilets wliich flow through the precincts, furnishing
the establishment with an abundiint supply in every part,
for the irrigation of the gardens and orchards, the sanitary
requirements of the brotherhood, and for the use of the
ofKces and workshops. The precincts are diWded across
the centre by a wall, running from N. to S., into an
cuter and inner ward, — the former containing the menial,
tb9 litter the monastic building's. The precincts are
entered by a gateway (P), at the extreme western ex-
tremity, giving admi.^sion to the lower ward. Here the
bams, granaries, stables, shambles, workshops, and work-
men's lodgings were placed, without any regard to eym-
Oairvaux, No. 1 (Cistercir.n), General Plan,
A. Clolsteri.
B Ovena, and Corn and
Oll-mllla.
C. St Bemaid's CcD.
D. Clilef Entrance.
E. Tanks for FiAh.
F. Guest Mouse.
O Abbot'a Jiuuso.
II. .Stnbles.
I. Winc-prcaa uid Ilay-
cl'amber.
K. rar'.our.
L. WorkEhopaandworli-
mcn's Lodglcira.
M. Slftu^hter-hoiwe.
N. Bams oBd Stablee^
0. Public Preasa
1'. Gateway
R. Remains of Old
Monaatery.
S. Oratory.
V. Itlc-works.
X. Tile-kiln.
I Y. Water-coursea.
metry, convenience being the only consideration. Ad-
vancing eastwards, we have before us the wall separatihg
the outer and inner ward, and the gatehouse (D) affording
communication befveen the two. On passing through the
gateway, the outer court of the inner ward was entered,
with the western facade of the monastic church in front
Immediately on the right of entrance was the abbot's
house (G), in close proximity to the guest-house (F). On
the other side of the court were the stables, for the accommo-
dation of the horses of the guests and their attendants (H).
The church occupied a central position. To the south
were the gyeat cloister (A), surrounded by the chief monas-
tic buildings, and further to the east the smaller cloister,
opening out of which were the infirmary, novices' lodgings,
nnd quarters for the aged monks. Still further to the east,
divided from the monastic buildings by a wall, were the
veijetable gardens and orchards, and tank for fish. The
large fish-ponds, an indispensable adjunct to any ecclesia»-
tical foundation, on the formation of which the monkj
lavi.'ihed extreme earc and pains, and which often remaio
as almost the only visible traces of these vast establish-
menti, were placed outside the abbey walls.
The Plan No. 2 furnishes the ichnography of the dis-
tinctly monastic buildings on a larger scale. The usually
unvarying arrangement of the Cistercian houses allows us
to accept this as a type of the monasteries of this order.
The church (A) is the chief feature. It consists of a vast
nave of eleven bays, entered by a narthex, with a transept
and short apsidal choir. (Itmayberemarkedthat theeastern
limb in all unaltered Cistercian churches is remarkably
short, and usually square.) To the east of each limb'o<"
^^^m
Clauvau, Xo. 2 (Cistercian), Monastic Buildings.
A. Chnrch.
B. Cloister.
C. Chapier-HoBse.
D. Monks' Parlour
E. Calefactory.
V. Kitchen and Court
G. Refectory
11. Cemetery.
I. Little Cloister.
K. Infirmary.
U Loilclngs of NoTlce».
SI. Old Guc!t-Uou8e.
N. Old AbbcfsLodglnEa.
0, Cloister of Supemn-
mcran- MoLi^a.
r. Abto:e Hall,
Q. Cei: of Si Bercard.
IL Stables.
S. CeKara and St«r4H
hoosex
T. Watcr-cooTse.
U. Saw-mill and OD-mllL
V. Curricr'a Worksliopa.
X. SacrlBty.
V. Ll:tl« Library
Z. Undercroft of Dof-
mitory.
the transept are two square chapels, diWded according to
Cistercian rile by solid walls. Nine radiating chapels^
similarly divided, surround the apse. The stalls of the •
monks, forming the ritual choir, occupy the four eastern
bays of the nave. There was a second range of stalls in
the extrei e western bays of the nave for thefratres amversi,
or lay brothers. To the south of the church, so as to
secure as much sun as possible, the cloister was invariably
placed, except when local reasons forbade it. Roimd the
cloister (B) were ranged the buildings connected witli tho
monks' daily life. The chapter-house (C) always opened
out of the cast walk of the cloister iu a Unfi.Tvil'h fhg
CISTERCIAN.]
ABBEY
17
ClMiraui.
south transept In Cistercian houses this was quadran-
gular, and was divided by pillars and arches into two or
three aisles. Between it and the transept we find the
Bicristy (X), and a small book room (Y), armarinlum,
where the brothers deposited the volumes borrowed from
the Lbrary. On the other side of the chapter-house, to
the south, is a passage (D) conununicating with the courts
and buildings beyond. This was sometimes known as the
parlour, colloquii locus, the monks having the privilege of
conversation here. Here also, when discipline became
allowed to display their goods. Beyond this we often find
the calefactorium, or day-room — an apartment warmed
by flues beneath the pavement, where the brethren, half-
frozen during the night offices, betook themselves after the
conclusion of lauds, to gain a little warmth, grease their
aandals, and get themselves rcf»dy for the work of the day.
In the plan before us this apartment (E) opens froia the
Bouth cloister walk, adjoining" the refectory. The place
usually assigned to it is occupied by the vaulted substruc-
ture of the dormitory (Z). The dorr/iitory, as a rule, was
placed on the east side of the cloister, running over the
calefactory and chapter-house, and joined the south transept,
where a flight of steps admitted the brethren into the
church for jioctumal services. Opening out of the dor-
mitory was always the necessarium, pl;^rined with the
greatest regard to health and cleanliness, a water-course
Invariably running from end to end. The refectory opens
out of the south cloister at (G). The position of the refec-
tory is usually a marked point of difference between Bene-
dictine and Cistercian abbeys. In the former, as at Can-
terbur)', the refectory ran east and west parallel to the nave
of the church, on the side of the cloister furthest removed
from it. In the Cistercian monasteries, to keep the noise
and sound of dinner still further away from the sacred
building, the refectory was built north and south, at right
angles to the a.xis of the church. It was often divided,
sometimes into two, sometimes, as here, into three aisles.
Outside the refectory door, in the cloister, was the lavatory,
where the monks washed their hands at dinner time. The
buildings belonging to the material life of the monks lay
near the refectory, as far as possible from the church, to
the S.W. With a distinct entrance from the outer court
was the kitchen court (F), with its buttery, scullery, and
larder, and the importani, adjunct of a stream of running
water. Further to the west, projecting beyond the line of
the west front of the church, were vast vaulted apartments
(SS), serving as cellarsand storehouses, above which was the
dormitory of the conversi. Detached from tliese, and sepa-
rated entirely from- the monastic buildings, were various
vrorkshops, which convenience required to be banished to
the outer precincts, a saw-mill and oil-mill (UU) turned
by water, and a currier's shop (V), where the sandals and
leathern girdles of the monks were made and repaired.
Returning to the cloister, a vaulted passage admitted to
the small cloister (I), opening from the north side of which
were eight small cells, assigned to the scribes employed in
copying works for the library, which was placed in the
upper story, accessible by a turret staircase. To the
south of the small cloister a long hall will be noticed.
This was a lecture-hall, or rather a iall for the religious
disputations customary among the Cistercians. From this
cloister opened the infirmary (K), with its hall, chapel,
cells, blood-letting' house, and other dependencies. At the
eastern verge of the vast group of buildings we find the
Tiovices' lodgings (L), with a third cloister near the
novices' quarters aud the original gaest-house (M). De-
tached from the great mass of the monastic edifices was
the original abbot's house (N), with its diniiig-hall (P).
Closely adjoining to this, so that the eye of the father of
1—2
the whole establishment should be constantly over those
who stood the most in need of his watchful care, — those
who were training for the moUas>tic life, and those who had
worn themselves out in its duties, — was a fourth cloister
(0), with annexed bmldiugs, devoted to the aged and
infirm members of the establishment, llie cemetery, the
last resting-place of the brethren, lay to the north side of
the nave of the church (H).
It will be seen that the arrangement of a Cistercian
monastery was in accordance with a clearly-defined system,
The base court nearest to the outer wall contained the
buildings belonging to the functions of the body as agri-
culturalists and employers of labour. Advancing into the
inner court, the buildings devoted to hospitality are found
close to the entrance ; while those connected with the
supply of the material wants of the brethren, — the kitchen,
cellars, &e., — form a court of themselves outside the cloister,
and quite detached from the church. The church refec-
tory, dormitory, and other buildings belonging to the
professional Ufe of the brethren, surround the great
cloister. The small cloister beyond, with its scribes'
ceUs, library, hall for disputations, osc, is the centre of the
literary Ufe of the community, 'fhe requirements of sick-
ness aud old age are carefully pro'dded for in the infirmary
cloister, and that for the aged aud infirm members of the
establishment. The same group contains the qiiarters of
the novices.
This stereotyped arrangement is further illustrated by Citeau*
the accompanying bird's eye view of the mother establish-
^^f^^^^'MMS.^m^
A. CrosB.
b. Gatc-Houae,
C. Almonry.
D. ChftpcL
E. Inner G^'e-Uouae.
F. Stable.
G. Dormitory of Lft/
tircttirco.
meat of Citeaux.
Bird's eye View of Citcau.-^u
IL Abbo;'j House.
I. KltcliCD.
K. Kcfcctory.
L. Staircase tuDormitOl 7.
M. Donnitoi7.
N. Clmrch.
P. Library.
R. Innmifiry.
S. I>otir to (.lie Cliurcik
for the Lny Biv.li csft
T. Baw Coort.
V. GrcRt Cloister.
W. Small Clolnler.
X. Boundaiy W^X
A crues (A), planted ou the high rocdL
18
ABBEY
[eiSTERCIAH.
tit: •;x. directs travellers to the gate of the monastery, reached hy buttery. The arches of the lavatory ore to be seen near
aa avenue of trees. On one side of the gate-houso (B)
is a long builJirg (C), probably the almonry, with a
dormitory above for the lower class of guests. On the other
side is a chapel (D). As soon as the porter heard a stranger
knock at the gate, ho rose, saying, JJeo gratias, the oppor-
tunity for the exercise of hospitality being regarded as a
cause for thankfulness. On opening the door he welcomed
the now arrival with a blessing — JSenedicile Ho fell on
his knees before him, and then went to iiiform the abbot.
However important the abbot's occupations might be, he
He also throw himself at his guest's feet, and conducted
him to the chapel (D) purposely built close to the gate.
After a short prayer, the abbot committed the guest tu
the caro of tho brother hospitaller, whoso duty it was to
provide for his wants, and conduct tho beast on which he
might bo riding to the stable (F), built adjacent to the
inner gate-housa (E). This inner gato conducted into
the base court (T), round which were placed the barns,
stables, cow-sheda, &C. On tho eastern side stood the
dormitory of tho lay brothers, /raires conversi (G), detached
from tho cloister, with cellars and storehouses below. At
(H), also outside the mbnastic buildings proper, was the
abbot's house, and annexed to it the guest house. For
these buildings there was a separate door of entrance into
the church (S). The large cloister, with its surrounding
arcades, is seen at V. On the south end projects tho
refectory (K), with its kitchen at (I), accessible from the
base court. Tho long gabled building on the east side of
the cloister contained on the ground floor tho chapter-
house and calefactory, with tho monks' dormitory above
(M), commuuicatiiig with the south transept of the church.
At (L) was the staircase to the dormitory. The small
cloister is at (W), where were tho carols or cells of the scribes,
with tho bbrary (P) over, reached by a tunet staircase.
At (R) we see a portion of the infirmary. Tho whole pre-
cinct is siirrounded by a strong buttressed wall (XXX),
pierced with arches, through which streams of water are
introduced. It will be noticed that the choir of tho church
is short, and has a square end instead of the usual apse.
Tho tower, in accordance with the Cistercian rule, is very
low. The windows throughout accord with the studied
simplicity of the order.
The English Cistercian houses, of which there are such
extensive and beautiful remains at Fountains, Rievaulx,
ICiikstall, Tintern, Netley, ifec, wero mainly arranged after
tlie same plan, with sUght local variations. As an example,
v,e give the ground-plan of Kirkstall Abbey, which is one
of tho best preserved and least altered. The church here
|Ki7kstoH. is of , the Cistercian type, with a short chancel of two
squares, and transepts %rith three eastward chapels to each,
Jittded by solid walls (2 2 2). The whole is of the most
elTidied plainness. The ■windows are unornamented, and
the nave has no triforium. The cloister to the south (4)
occupies tho whole length of the nave. On the»east side
titauds the two-aisled chapter house (5), between which and
tile south transept is a small sacristy (3), and on the other
side;. two small apartments, ono of which was probably
tho^arlour (G). Beyond this stretches southward tho
calefactoiy or day-room of the monks (1-1). Above this
whole range of building runs the monks' dormitory, opening
by stairs into the south transept of the church. At the
other end were the necessaries. On the south side of the
cloister ',we have tho remains of the old refectory (11),
iruuning,' as in EenetUctiue houses, from east to west, and
iho new refectory (12), which, mth the increase of the
inmates of the house, superseded it, stretching, as is usual
in Cl-jtercian houseSj from north to south. Adjacent to
this apartjucut arc tho remains of the kitchen, pantry, and
SSDslanO.
tho refectory entrance. The western side of tho cloister
is, in usual, occupied by vaulted cellars, supporting on the
upper story the dormitory of tho lay brothers (8). Ex
tending from the south-east angle of the main group of
buildings are the walls and foundations of a secondary
group of considerable extent These have been identified
cither with tho hospitium or ■nith the abbot's Louse, but
they occupy the position in which the infirmary \s mora
usually found The hall was a very spacic^us apartment,
measuring 83 feet in length by 48 feet 'J inches in btcadtk
^i|py
KirkstAll Abbey, Yorkshire (Cistercian).
L Church.
2. Clmpell
S. Sncrtsty.
4. Clolatrr.
fi Chnpter-Houso.
C. P&rlour.
7. Pu'nialiment Cell (?)
8. Cellars, with DonnitoriM for cun-
Teral o%'er.
9. Gucat-Hoiue.
10. Commcn Room.
11. Old Refectory.
12. Now Refectory.
13 Kitchen Court,
11 Calefactory or nay-Hoom.
\i. Eltcheo and Offlcca,
16-19, UncertaiD; pcrliapa OfBcce coSh
nected with the Inflmiary,
20, Infirmary trr ^bt>ol'a Uouse.
and was divided by two rows of columns. The fish-ponda
lay between the monastery and the river to tho south. The
abbey mill was situated about 80 yards ta the north-west.
The mill-pool may be distinctly traced, together with the
gowt or mill stream.
Fountains Abbey, first founded A.D. 1132, deserves '
special notice, as one of the largest and best preserved
Cistercian houses in England. But the earUer buildings
period of the order, causing deviations from the strict
Cistercian tj-pe. The church stands a short distance to
the north of tho river Skell, the buildings of the abbey
stretching down to and even across the stream. We have
the cloister (H) to the south, -nith the three-aisled chapter-
house (I) and calefactory (L) opening from its eastern walk,
and the refectory (S), with tho kitchen (Q) sod buttery (T)
attached, at right angles to its southern walk. Parallel
with the western walk is an immense vaulted substructuro
(U), incorrectly styled the cloisters, serving as cellars and
store-rooms, and supporting the dormitory of the convern
above. This building extended across the nvor. At its
CISTEECIAN.j
S.W. corner were the necessaries (V), also built, as usual,
above tbe swiftly flowing stream. The monies' dormitory
was in its usual position above the chapter-house, to the
south of the transept. As peculiarities of arrangement
may be noticed the position of the kitchen (Q), between the
refectory and calefactory, and of the infirmary (W) (unless
ther.; is some error in its designation) above the river to
ABBEY
iVi
Groind Plan of Fountains Ablmy, Yorkshire.
A, Kive of the Charch.
N. CellRr.
Z. Gate-nonae.
it, TraiiSfpt.
0. Brew Houae.
Abbot's Houb
C. Ol.apela.
P. Prisons.
1. PasBa^e.
D. Tower.
Q. KltcheiL
3. Great HalL
E. Sacriaty.
R. Offices.
8. Refectory.
F. Chofr.
S. Refectory.
4. Buttery.
a. Chapel of Klae
T. Buttery
&. Storehojse.
/J tars.
U. Ccllarftaiid Store-
6. Chapel.
K. C'olflter.
liousaa.
7. Kltclieo.
L Chaptcr-Hoase.
V. NcccHaary.
8. AflhplL
K. Base Court.
W. Iiiflrmao (?)
0. Yard.
h. Calcftictory.
X. Gii-'st-liuusca
10. Kitchen Tank.
M. Water Course.
Y. MIU Biidgc
the west, adjoining the guest-houses (XX). We may also call
attention to the greatly lengthened choir, commenced by
Abbot John of York, 120^-1211, and carried on by his
suocoBsor, tormiEaiujg, like Dnr linm Cathedral, in an
eastern transept, the work of Abbot John of Kent, 1220-
1247, and to the tower (D), added not long before the dis-
solution by Abbot Huby, 1494-1526, in a very unusual
position at the northern end of the north transept. The
abbot's house, the largest and most remarkable example of
this class of bvdldings in the kingdom, stands south tn
the east of the church and cloister, from which it is divided
bythe kitchen court(K),3urrouu.dedbythe ordinary domestic
offices. A considerable portion of this house was erected
on arches pver the SkeU. The size and character of this
house, probably, at the time of its erection, the most
spacious house of a subject in the kingdom, not a castle,
bespeaks the wide departure of the Cistercian order from
the stern simplicity of the original foundation. The hall
(2) was one of the most spacious and magnificent apart-
ments in mediieval times, measuring 170 feet by 70 feet.
Like the haU in the castle at Winchester, and Westminster
Hall, as originally built, it was divided by 18 pillars and
arches, with 3 aisles. Among other apartments, for the
designation of which we must refer to the ground-plan,
was a domestic oratory or chapel, 46J feet by 23 feet, and •
a kitchen (7), 50 feet by 38 feet. The whole arrangements
and character of the building bespeak the rich and powerful
feudal lord, not the humble father of a body of hard-
working brethren, bound by vows to a life of poverty and
self-denying toiL In the words of Dean MUman, " the
superior, once a man bowed to the earth with humility,
care-worn, pale, emaciated, with a coarse habit bound
with a. cord, with naked feet, had become an abbot on his
curvetting palfrey, in rich attii-e, with his silver cross before
him, traveUing to take his place amid the lordliest of the
realm." — (Lai. Chriit., vol. ui p. 330.)
The buildings of the Austin Canons or Black Canons Bl.iok
(so called from the colour of their habit) present few Austin
distinctive -peculiarities. This order had its first seat in Cancn
England at Colchester, where a house for Austin Canons
widely. As an order of regular clergy, holding a middle
position between monks and secular canons, almost resem-
bling a community of parish priests living under rule,
they adopted naves of great length to accommodate large
congregations. The choir is usually long, and is some-
times, as at Llanthony and Christ Church (Twynham),
shut off from the aisles, or, as at Bolton, Kirkham, &c., is
destitute of aisles altogether. The nave in the northern
houses, not uufrequently, had only a north aisle, as at
Bolton, Brinkburn, and Lanercost. The arrangement of
the monastic buildings followed the ordinary type. The
prior's lodge was almost Invariably attached to the S.W.
angle of the nave. The annexed plan of the Abbey of
St Augustine's at Bristol, now the cathedral charch oi Brisi"'
JJ
Ji-5TU]:::::':::;C
^rr- ■•-■
i\ rj' ^f^i^i^T^^^f^
St Augustine's Abbey, Bristol (Bristol Cathedral).
A. Charch.
B. Oroat Clclster.
C Uttlb aolstor.
E. Calefactory.
F. Se'octory.
G. ruioiu.
n. Kitchen.
L Kitchen Court
K. Cellara.
L. Abbot 8 HalL
P. Abtmt'fl Gaton^ay.
&, Intlrmary.
.1, Fr!ar«' LxxSglnK
T. King's Wall
V. Oncst-Hrtuaa
'.V. Athcy Gatew'i-,
.\. Ba-Tii. subloa. .-
T. Ltv&toiJ,
20
ABBEY
[CAKTHUSIAN.
that city, siuiwn tlio arrangement of the buildings, which
departs very little from the ordinary Benedictine tyjje.
The Austin Canons' house at Tliornton, in Lincolnshire, js
remarkable for the size and magnificence of its gatehouse,
the upper floors of which formed the gue«t-house of the
establishment, and for possessing an octagonal chapter-
house of Decorated data
Pretfionfl. The Premonstraiensian regular canons, or White Canons,
lr«tensiaii. had as many as 35 houses in England, of which the most
perfect remaining are tlioso of Easby, Yorkshire, and
liayham, Sussex. The head house of the order in England
■was Welbeck. This order <\m3 a reformed branch of the
Austin canons, founded, k.n. 1119, by Norbert (born at
Xanten, on the Lower Rhine, c. 1080) at Pr^montrd, a
Bccluded marshy valley in the forest of Coucy, in the
diocese of Laon. The order spread Tt-idely. Even in the
founder's lifetime it possessed houses in S)Tia and Pales-
tine. It long maintained its rigid austerity, till in the
course of years wealth impaired its discipline, and its
members sank into indolence and luxurj'. The Premon-
. itrtitensians were brought to England shortly after A.D.
1140, and were first settled at.Nowhouse, in Lincolnshire,
tiear the Ilumber. The ground-plan of Easby Abbey,
)wing to its situation on the edge of the steeply-sloping
banks of a river, is singularly irregular. The cloister is
duly placed on the south side of the church, and the'
chief buildings occupy their "usual positions round it.
I?ut the cloister garth, as at Chichester, is not rectangu-
lar, and all the surrounding l:milding3 are thus made to
sprawl in a very awkward fashion. The church follows
the plan adopted by the Austin canons in their northern
Bbbe)-3, and has only one aisle to the nave — that to the
north ; while the choir is long, narrow, and aisleless.
Each transept has an aisle to the east, forming three
thapols.
The churcn at iiayuam was deftitute of aisle either to
nave or, choir. The latter terminated in a three-sided apse.
This church is remarkable for its exceeding narrowness in
proportion tp its length. Extending in longitudinal dimen-
sions 257 feet, it is not more than 25 feet broad. To
adopt the words of Mr Beresford Hope — " Stern Premon-
stratensian canons wanted no congregations, and cared
for no processions ; therefore they buUt their church like a
long room."
Carthusinn. fhe Cart/iusian order, on its establistiment by St Bruno,
about A.D. 1084, developed a greatly modified form and
arrangement of a monastic institution. The principle of
this order, which combined the coenobitic with the solitary
life, demanded the -erection of buildings on a novel plan.
This plan, which was first adopted by St Bruno and his
twelve companions at the original institution at Chartreux,
near Grenoble, was maintained iu aU the Carthusian
establishments throughout Europe, even after the ascetic
severity of the order had been to some extent relaxed, and
the prinjitive simplicity of their buOdings had been ex-
changed for the magnificence of decoration which charac-
terises such foundations as the Certosas of Pavia and
Florence. According to the rule of St Bruno, all the
members of a Carthusian brotherhood lived in the most
absolute solitude and silence. Each occupiel a small
detached cottage, standing by itself in a small garden
.surrounded by high walls and connected by a common
corridor or cloister.' In these cottages or cells a Carthusian
monk passed his time in the strictest asceticism, only
leaving his solitary dwelling to attend the services of the
Church, except on certain days when the brotherhood
assembled in the refectory.
The peculiarity of the arrangements of a Carthusian
monastery, or charter-house, as it was called in England,
from a- corniption of the French rhqrtreux, is exhibited in
the plan of that of Clermont, from Viollet le Due. The Clermoot,
whole cstablbhment is surrounded with a wall, furnished
at intervals with watch towers (R). The enclosure ia
divided into two courts, of which the eastern court, sur-
rounded by a. cloister, from which the cottages of the
monks (I) open, is much the larger. The two courts ar«
A. Cliurch.
Jl. Uonlu aiolr.
C. Trior's GnrdeiL
P. Great Cloister.
£. Chaptcr-HouM
P. PaMaiic.
0. Pr1oi-5 UkIj:-
lllKA.
n. Dovecot.
1. Cell!.
K. Chfipcl of rr«^
gibauil.
U SBcristy.
U. ChjipoL
K. Slililoa.
0. Gatevrajr-
r. Gucst-Cliara-
bent.
^. Bnrnft and
Granftilea
P.. Wfttcli Towert.
S. Urtle Cloister
T. Uukehouse.
V. Kitchen.
.\. Refectory.
v. Cemetery.
Z. Prison.
n.CcllofSnb-pilor
V. Garden nf d".
C.trtliusi.-iu Monastery of Clermont
divided by the main buildings of tne monastery, indiding
the church, the sanctuary (A), divided from (B), the monks',
choir, by a screen with two altars, the smaller cloister to
the south (S) surrounded by the chapter-house (E), the
refectory (X)— these buildings occupj-ing their normal
jjosition — and the chapel of Pontgibaud (K). The kitcheb
with its ofnces (V) llfes behind the refectory, accessible
from the outer court without entering the cloister. To
the north of the church, beyond the sacristy (L), and the
side chapels (M), we find the cell of the sub-prior (a), with
its garden. The lodgings of the- prior (G) occupy the
centre of the outer court, immediately in front of the west
door of the church, and face the gateway of the convent (O).
A small raised court with a fountain (C) is before it. This
outer court also contains tlie guest-chambers (P), the
stables, and lodgings of the lay brothers (N), the barns
and gianaries (Q), the dovecot (H), and the bakehouse (T).
At (Z) is the prison. (In this outer court, in all the earlier
foundations, as at Witham, there was a smaller church in
addition to the larger church of the monks.) The outer and
inner court are connected by a long passage (F), wide
cells of the brethren -with fuel. The number of cells sur-
rounding the great cloister is 18. They are all arranged
on a uniform plan. Each little dwelling contains three
rooms : a sitting-room (C), warmed with a stove iu winter;
a sleeping-room (D), furnished 'with a bed, a table, a bench,
and a bookcase; and a closet (E). Between the cell and
the cloister gallery (A) is a passage or corridor (B), cutting
ofif the inmafe of the cell from all sound or movement
which might internipt his meditations. '.■_ The superior had.
CARTHUSIAN. J
ABBEY
21
ClemoEt. free access to this corridor, and througli open mches was able
to inspect the garden without being seen. At (I) is the
hatch or tura-table, in which the daUy allowance of food was
deposited by a brother appointed for that purpose, aflford-
ing no Tiew either inwards or outwards. (H ) is the garden,
A. Oolstcr GaBery
B. Corridor.
C. Living Room.
D. Sleeping Rooni.
E. ClOKli
F. CoTcred Walk
G. yccc:snrf
n. Garden.
I. Hau;h.
K. Wood-houaa
Carthusian Cell, Clermont
cultivated by the occupant of the cell At (K) is the
wood-house. (F) is a covered walk, with the necessary at
the end. These arrangements are found with scarcely any
variation in all the charter-houses of Western Europe.
The Yorlcshire Charter-house of Mount Grace, founded by
Thomas Holland the young Duke of Surrey, nephew of
Richard II., and Marshal of England, during the revival
of the popularity of the order, about A.D. 1397, is the most
perfect and best preserved English example. It is charac-
terised by all the simplicity of the order. The church is a
modest building, lon^, narrow, and aisleless. Within the
wall of enclosure are two courts. The smaller of the two,
the south, presents the usual arrangement of church, refec-
tory, &c., opening out of a cloister. The buildings are
plain and solid. The northern court contains the ceils, 1 i
in number. It is surrounded by a double stone wall, the
two walls being about 30 feet or 40 feet apart. Between
these, each in its own garden, stand the cells ; low-built
two-storied cottages, of two or three rooms on the ground-
floor, lighted with a larger and a smaller window to tiie
side, and provided with a doorway to the court, and one at
the back, opposite to one in the outer wall, through which
the monk may have conveyed the sweepings of his cell and
the refuse of his garden to the " eremus " beyond. By the
side of the door to the court is a little hatch, through which
the daily pittance of food was supplied, so contrived by
turning at an angle in the wall that no one could either
look in or look out. A very perfect example of this hatch
— an arrangement belonging to all Carthusian houses —
exists at Miraflores, near Burgos, which remains nearly as
it wa.1 completed in 1480.
There were only nine Carthusian houses in England.
Witham. The earliest was that at Witham in Somersetshire, founded
by Henry 11., by whom the order was first brought into
England. The wealthiest and jnost magnificent was that
of Shene or Richmond in Surrey, founded by Henry V.
about A.D. 1414. The dimensions of the buildings at
Shenei are stated to have been remarkably large. The
great court measured 300 feet by 250 feet ; the cloisters
were a square of 500 feet ; the hall was 110 feet in length
by GO feet in breadth'. The most celebrated historically is
tlieCliarter-houseof London, founded by Sir Walter Manny
*.D. 1371, the narao of which is preserved by the famous
public scbool established on the site by Thomas Suttoa
A.D. IPll.
An article on monastic arrangements would be incom-
plete without some account of the convents of the Mendi- MendicanT
cant or Preaching Friars, including the Black Friara or Friara.
Dominicans, the Grey or Franciscans, the White or Carmel-
ites, the Eremite or Austin Friars. These orders arose at
the beginning of the 13th century, when the Benedictines,
together with their various reformed branches, had termi-
nated their active mission, and Christian Europe was ready
for a new religious revival. Planting themselves, as a rule,
in large towns, and by preference in the poorest and most
densely populated districts, the Preaching Friars were
obliged to adapt their buildings to the requirements of the
site. Regularity of arrangement, therefore, was not pos-
sible, even if they had studied it. Their churches, built
for the reception of large congregations of hearers rather
than worshippers, form a class by themselves, totally unlike
those of the elder orders in ground-plan and character.
They were usually long parallelograms unbroken by tran-
septs. The nave very usually consisted of two equal bodies,
one containing the stalls of the brotherhood, the other left
entirely free for the congregation. The constructional
choir is often wanting, the whole church forming one unin-
terrupted structure, with a continuous range of windows.
The east end was usually square, but the Friars Church at
Winohclsea had a-polygonal apse. We not unfrcquently
find a single transept, sometimes of great size, rivalling or
exceeding the nave. This arrangement is frequent in
Ireland, where the numerous small friaries afi'ord admirable
exemplifications of these peculiarities of ground-plan. The
friars churches were at first destitute of towers ; but in the
14th and 15th centuries, taU, slender towers w-?io com-
monly inserted between the nave and the choir. The Grey
Friars at Ly^n, where the tower is hexagon.il, is a good
example. The arrangement of the monastic buildings is
equally peculiar and characteristic. Wo miss entirely the
regularity of the buildings of the earlier orders. At the
Jacobins at Paris, a cloister lay to the north of the long
narrow church of two parallel aisles, while the refectory —
a room of immense length, quite deta,ched from the cloister
— stretched across the area before the west front of the
church. At Toulouse the nave also has two parallel aisles,
but the choir is apsidal, with radiating chapels. The refec-
tory stretches northwards at right anglestothecloister, which
lies to the north of the church, haiing the chapter-house
and sacristy on the east. As examples of English friaries
the Dominican house at Norrnch, and those of the Domini- Norwick
cans and Franciscans at Gloucester, may be mentioned. The GloucesteB
church of the Black Friars of Norwich departs from the
original type in the nave (now St Andrew's Hall), in having
regular aisles. In this it resembles the earUep-examples of
the Grey Friars at Reading. The choir is long and aisle-
less ; an hexagonal tower between the two, like that exist-
ing at Lynn, has perished. The cloister and monastic
buildings remain tolerably perfect to the north. The
Dominican convent at Gloucester stiU exhibits the cloister-
court, on the north side of which is the desecrated church.
The refectory is on the west side, and on the south the
dormitory of the 13th century. This is a remarkably good
example. There were 18 cells or cubicles on each side,
divided by partitions, the bases of which remain. On the
east side was the prior's house, a building of later date.
At the Grey or Franciscan Friars, the church followed the
ordinary type in having two equal bodies, each gabled,
with a continuous range of windows. There was a slender
tower between the nave and choir. Of the convents of the
Carmelite or White Friars we have a good example in the
Abbey of Hulme, near Alnwick, the first of the order in Hulmg
England, founded A.D. 1240. The church is a narrow
22
A B B - A B B
Mendicant oUong, destitute of aisles, 123 feet long by only 26 feet
Friara. wida The cloisters are to the south, with the chapter-
house, (fee, to the east, with the donnitory over. The
prior's lodge is placed to the west of the cloister. The
giiest-housea adjoin the entrance gateway, to which a chapel
was annexed on the south side of the conventual area.
The nave of the church of the Austin Friars or Eremites
in Loudon is still standing. It is of Decorated d&te, and
ima wide centre and side aisles, divided by a very light and
graceful arcade. Some fragments of the south walk of the
cloister of the Grey Friars exist among the buildings of
Christ's Hospital or the Blue-Coat School. Of the Black
Friars all has perished but the naco. Taken as a whole,
the remains of the establishments of the friars aflFord little
warrant for the bitter irirective of the Benedictine of St
Alban's, Matthew Paris : — " The friars who have- been
founded hardly 40 years have built residences as the
palaces of kings. These are they who, enlarging day by
day their sumptuous edifices, cncircUng them with lofty
walls, lay up in them their incalculable treasures, impru-
dently transgressing the bounds of poverty, and violating
the very fundamenta.1 rules of their profession." Allowance
must here be made for jealousy of a rival order just rising
in popularity.
Eveiy largo monastery had depending upon it one or
Cells. more smaller establishments known as cells. These cells
were monastic colonies, sent forth by the parent house, and
{>lanted on some outlying estate. As an example, we may
refer to the small religious house of St Mary Magdalene's,
a cell of the great Beneilictiuo house of St Mary's, York, in
the valley of the Witham, to the south-east of the city of
Lincoln. This consists of one long narrow range of build-
ing, of which the eastern part formed the chapel, and
the western contained the apartments of the handful of
monks of which it was the home. To the east may be
traced the site of the abbey mill, with its dam and mill-
lead. These cells, when belonging to a Cl^iniac house,
were called Obediential.
The plan given by Viollot le Duo of the Priory of St
Jean de» Bona Uommea, a Cluniac cell, situated between
the town of Avallon and the village of Savigny, shows that
these diminutive establishments comprised every essential
feature of a monastery, — chapel, cloister, chapter-room,
refectory, dormitory, all grouped aceording to the recog-
nised arrangement.
Those Cluniac obedientuje differed from the ordinary
Benedictine cells in being also places of punishment, to
which monks who had been guilty of any grave infringe-
ment of the rules were relegated as to a kuid of peniten-
tiary. Here they were placed under the authority of a
prior, and were condemned to severe manual labour, ful-
filling the duties usually executed by the lay brothers, who
acted as farm-servants.
The outlying fanning establishments belonging to the
monastic foundations were known as villte or granges.
They gave employment to a body of conversi and labourers
under the management of a monk, who bore the title of
Brother Hospital-lei the granges, Uke their parent in-
stitutions, affording shelter and hospitality to belated
travellers.
Authorities: — Dngdale, Monatticon; Fosbrooke, British
M<machism; Hclyot, Dictionnaire des Ordres Eeligieux;
Lenoir, Architecture Monastique; VioUet le Due, Diction-
naire Maiscnnee, de ■ U Architecturt Francaue ; Walcott,
Conventual Arrangement; Willis, Abbey of St Gall; Archseo-
logical Journal, voL t > Conventual Buildings of Canter-
bury ; CvlTzoq, Monasteries of the Levant. (e. v.)
ABBLATE QRASSO, a town in the north of Italy, near
the Ticino, 14 miles W.S.W. of MOan. It has silk manu-
factures, and contains about 5000 inhabitantii
ABBON OF FLErnY. or Asbo FLOEiACENsrs, a learned
Frenchman, bom near Orleans in 945. He distinguished
hinuelf in the schooU of Paris and Kheims, and was a profi-
cient in science, as known in his time. After spending two
years in England, assisting Archbishop Oswald of York in
restoring the monastic system, ho returned to France, and
was made Abbot of Fleury (970). He waa twice sent
to Rome by Robert the Wise (986, 996), and on each occa-
sion succeeded in warding off a threatened papal interdict
He was killed in 1004, in endeavouring to quell a monkish
revolt He wrote an epitome of the Lives of the Soman
Pontiffs, Jjesidcs controversial treatises, letters, &c
ABBOT, the head and chief governor of a community
of monks, called also in the East Archimandrita, from
mandra, " a fold," ot Uegumenos. The name ahhol is derived
from the Hebrew -*, Ah, or father, through the Syriac
Abba. It had its origin in the monasteries of Syria,
whence it spread through the East, and soon became
accepted generally in all languages as the designation of
the head of a monastery. At first it was employed as a
respectful title for any monk, as wo learn from St Jerome
(in Epist. ad GaL iv. 6, in Matt zxiiL 9), but it was soon
restricted to the Superior.
The name abbot, though general in the West, was not
universal Among the Dominicians, Carmelites, Angus-
tines, Ac, the superior was called Praepositus, " Provost,"
and Prior; among the Franciscans, Gustos, "Guardian;"
and by the monks of Camaldoli, Major.
Monks, as a rule, were -laymen, nor at the outset wm
the abbot any exception. All orders of clergy, therefore,
even the " doorkeeper," took precedence of him For
the reception of the sacraments, and for other religions
offices, the abbot and his monks were commanded to
attend the nearest church. — (Novellce, 1 33, c. iL) This rale
naturally proved inconvenient when a monastery was
situated in a desert, or at a distance from a city, and
necessity compelled the ordination of abbots. This innova-
tion was not introduced without a struggle, ecclesiastical
dignity being regarded as inconsistent with the higher
spiritual life, but, before the close of the 5th century, at least
in the East, abbots seem almost universally to have become
deacons, if not presbyters. The change spread more
slowly in the West, where the office of abbot was commonly
filled by laymen tQl the end of the 7th century, and
partially so up to the lltL Ecclesiastical Councils were,
however, attended by abbots. Thus, at that held at Con-
stantinople, A.D. 448, for the condemnation of Eutychcs,
23 archimandrites or abbots sign, with 30 bishops, and,
cir. A.D. 690, Archbishop Theodore promulgated a canon,
inhibiting bishops from compelling abbots to attend
councils. Examples are not uncommon in Spain and
in England in Saxon times. Abbots were permitted
by the Second Council of Nicaea, A.D. 787, to ordain
their monks to the inferior orders. This rule waa
adopted in the West, and the strong prejudice against
clerical monks having gradually broken down, eventually
monks, almost without exception, belonged to some grade
of the ministry.
Originally no abbot was penpitted to rule over more
than one monastic community, though, in Some exceptional
cases, Gregoiy the Great allowed the rule to be broken.
As time went on, violations of the rule became increasingly
frequent, as is proved by repeated enactments against it
The cases of Wilfrid of York, cir. a.d. 675, who held the
abb.acy of the monasteries he had founded at He7.ham and
Ripon, and of AJdhelm, who, at the same date, stood ii
the same double relation to those of Malmesbury, Frome,
and Bradford, arc only apparent transgressions of the rule.
We find more decided instances of plurality in Hugh of
, the T'^ynl Carlovinejian house, cir. 720, who was at the same
ABBOT
23
tims Bishop of Rouen, Paris, Bayeui, and Abbot of Fonte-
nelle and Jumi%es ; and Sidonius, Bishop cf Constance,
who, being already Abbot of Rcichenau, took the abbacy of
St Gall also. Hatto of llentz, cii: 912, annexed to his
Ece no less than 12 abbacies.
In Egypt, the first home of monasticism, we find abbots
in chief or arcMmandrites exercising jurisdiction over 'a
large number of communities, each of which had its own
abbot. Thus, Cassian speaks of an abbot in the Thebaid
who had 500 monks under him, a number exceeded in
other cases. In later times also, general jurisdiction was
exercised over the houses of their order by the abbots of
Monte Cassino, St Dalmatius, Cluguy, (tc. The abbot of
Cassino was styled Abbas Abbatum. The chiefs of other
orders had the titles uf Abbas Generalis, or Magister, or
Minister Generalis.
Abbots were originally subject to episcopal jurisdiction,
and continued generally so, in fact, in the West till the
11th century. The Codex of Jicstinian (lib. L tit. LiL do
Ep. leg. xl.), expressly subordinates the abbot to epis-
copal oversight. The first case recorded of the partial
exemption of an abbot from episcopal control b that of
Faustus, Abbot of Lerins, at the Council of Aries, a.d.
456 ; but the oppressive conduct, and exorbitant claims
and exactions of bishops, to which this repugnance to
episcopal control is to be traced, far more than to the
arrogance of abbots, rendered it increasingly frequent,
and, in the 6th ccntiuy, the practice of exempting religious
houses partly or altogether from episcopal control, and
making them responsible to the Pope alone, received an
impulse from Gregory the Great. These exceptions,
though introduced with a good object, had grown into a
wide-spread and crying evil by the 12th century, virtually
creating an imperium in imperio, and entirely depriving
the bishop of all authority over the chief centres of power
and influence in his diocese. In the 12th century the
abbots of Fulda claimed precedence of the Archbishop of
Cologne. Abbots more and more aped episcopal state,
and in defiance of the express prohibition of early councils,
and the protests of St Bernard and others, adopted the
episcopal insignia of mitre, ring, gloves, and sandals. A
mitre is said to have been granted to the Abbot of Bobbio
by Pope Theodorus I, A.D. 643, and to the Abbot of St
Savianus by Sylvester II., a.d. 1000. Ducange asserts
that pontifical insignia were first assigned to abbots by
John XVIIL, A.D. 1004-1009 ; but the first undoiibted
grant is said to be that to the Abbot of St Maximinian at
Treves, by Gregory VII. (Hildebrand), a.d. 1073-10S5.
The mitred abbots in England were those of Abingdon,
St Alban's, Bardney, Battle, Bury St Edmund's, St Augus-
tine's Canterbury, Colchester, Croyland, Evesham, Glas-
tonbury, Gloucester, St Benet's Hulme, Hyde, Malmes-
bury, Peterborough, Ramsey, Reading, Selby, Shrewsbury,
Tavistock, Thomey, Westminster, Winchcombe, St Mary's
York. Of these the precedence was originally yielded to
the Abbot of Glastonbury, until in A.D. 1154 Adrian IV.
(Nicholas Breakspear) granted it to the Abbot of St
Alban's, in which monastery he had been brought up.
Next after the Abbot of St Alban's ranked the Abbot of
Westminster.
To distinguish abbots from bishops, it was ordained that
their mitre should be made of less costly materials, and
ehould not be ornamented ■n-ith gold, a rule which was
Boon entirely disregarded, and that the crook of their
pastoral staflf should turn inwards instead of outwards,
indicating that their jurisdiction was limited to their own
bouse. The adoption of episcopal insignia by abbots
was followed by an encroachment on episcopal functions,
wiMch had to be specially but ineffectually gviarded against
by the Latcran Council, a.d. 1^23. In the East, abboU,
if in priests' orders, with the consent of the bishop, were,
as we have seen, permitted by the Second Nicene Council,
A.D. 787, to collier the tonsure and admit to the order of
we find them authorised by BeUarmine to be a.ssociatcd
with a single bishop in episcopal consecraliions, and per-
mitted by Innocent IV., a.d. 1489, to confer both the
subdiaconate and diaconate. Of course, they always and
and vesting them with the religious habit. In the first
instance, when a vacancy occurred, the bishop of the diocese
chose the abbot out of the monks of the convent, but
the right of election was transferred by jurisdiction to
the monks themselves, reserving to the bishop the con-
firmation of the election and the benediction of the new
abbot. In abbeys exempt from episcopal jurisdiction, the
confirmation and benediction had to be conferred by the
Pope in person, the house being taxed with the expenses
of the new abbot's journey to Rome. By the rule of St
Benedict, the consent of the laity was in some unde-
fined way required ; but this seems never to have been
practically enforced. It was necessary that an abbot
should be at least 25 years of age, of legitimate birth, a
monk of the house, unless it furnished no suitable can-
didate, when a liberty was allowed of electing from another
convent, well instructed him.self, and able to instruct others,
one also who had learned how to command by having prac-
tised obedience. In some exceptional cases an abbot was
allowed to name his own successor. Cassian speaks of an
abbot in Egypt doing this ; and in later times we have
another example in the case of St Bruno. Popfe and
sovereigns gradually encroached on the rights of the
monks, until in Italy the Pope had usurped the nomina-
tion of all abbots, and the king in France, with the ex-
ception of Clugny, Pr^montre, and other houses, chiefs of
their order. 'The election was for life, unless the .abbot
was canonicaUy deprived by the chiefs uf his order, or,
when he was directly subject to them, by the Pope or the
bishop.
The ceremony of the formal admission of a Benedictine
abbot in mediaeval times is thus prescribed by the consuetu-
dinary of Abingdon. The newly elected abbot was to
put off his shoes at the door of the church, and proceed
barefoot to meet the members cf the house advancing in
a procession. After proceeding up the nave, he was to
kneel and pray at the topmost step of the entrance of the
choir, into which he was to be introduced by the bishop
or his conunissary, and placed in his stall. The monks,
then kneeling, gave him the kiss of peace on the hand,
and rising, on the mouth, the abbot holding his staff of
office. He then put on his ahoes in the vestry, and a
chapter was held, and the bishop or his commissary
preached a suitable sermon.
The power of the abbot was paternal but absolute,
Umited, however, by the canons of the church, and, until
the general establishment of exemptions, by epi-scopal
control. As a rule, however, implicit obedience was en-
forced ; to act without his orders was culpable ; whUo it
was a sacred duty to execute his orders, however unrea-
sonable, until they were withdrawn. Examples among tha
Egyptian monks of this blind submission to the commands
of the superiors, exalted into a virtue by those who re-
garded the entire crushing of the individual will as the
highest excellence, are detailed by Cassian and others, — e.g.,
a monk watering a dry stick, day after day, for months, or
endeavouring to remove a huge rock immensely exceeding
his powers. St Jerome, indeed, lays doivu, as the principle
of the compact between the abbot and his monks, that they
should obey their superiors in all things, and perform what-
ever they commanded. — (Ep. 2, ad Eustoch. do ousted.
24
ABBOT
;Wrgin.) So despotic did the tyranny became in the West,
that in the time of Charlemagne it was necessary to re-
strain abbots by legal enactmenta from mutilating their
monks, and putting out their eyes; while the rule of St
Columba ordained 100 lashes as the punishment for very
•light offences. An ubbot also had the power of excom-
municating refractory mhis, which ho might use if desired
by their abbess.
The abbot was treated with the utmost submission and
reverence by the brethren of his house. When he appeared
either in church or chapter all present rose and bowed.
His letters were received kneeling, like those of the Pope
and the king. If he gave a command, the monk receiving
it was also to kneel. No monk might sit in his presence,
O"- leave it without his permission. The highest place v-as
naturally assigned to him, both in church and at table.
In the East he was commanded to eat with the other monks.
In the West the rule of St Benedict appointed him a sepa-
rate table, at which ho might entertain guests and strangers.
This permission opening the door to luxurious living, the
Council of Aix, a.d. 817, decreed that the abbot should
dine in the refectory, and be content with the ordinary
fare of the monks, unless he had to entertain a guest.
These ordinances proved, however, generally ineffectual to
secure strictness of diet, and contemporaneous literature
abounds with satirical remarks and complaints concerning
the inordinate oxtravaganee of the tables of the abbots.
When the abbot condescended to dine in the refectory, his
chaplains waited upon him with the dishes, a servant, if
necessary, assisting them. At St Alban's the abbot took
the lord's seat, in the centre of the high table, and was
served on silver plate, and sumptuously entertained noble-
men, ambassadors, and strangers of quality. When abbots
dined in their own private hall, the rule of St Benedict
charged them to invite their monks to their table, provided
there was room, on which occasions the guests were to ab-
stain from quarrels, slanderous talk, and idle gossipping.
The complaint, however, was sometimes made (as by Matt.
Paris of Wulsig, the third abbot of St Alban's), that they invited
ordinary attire of the abbot was according to rule to be the
same as that of the monks. But by the 10th century the
nile was commonly set aside, and wo find frequent com-
plaints of abbots dressing in silk, and adopting great
sumptuousness of attire. Nay, they sometimes laid aside
the monastic habit altogether, and assumed a secular dress.'
Thiswasanecessary consequenceof their following the chase,
iwhich was quite usual, and indeed at that time only naturaL
With the increase of wealth and power, abbots had lost
much of their special religious character, and become great
lords, chiefly distinguishgd from lay lords by celibacy.
Thus we hear of abbots going out to sport, with their men
carrying bows and arrows ; keeping horses, dogs, and
huntsmen ; and special mention is made of an abbot of
Leicester, dr. 1360, who was the most skilled of all the
nobility in hare-hunting. In magnificence of equipage and
retinue the abbots vied with the first nobles of the realm.
They rode on mules with gOded bridles, rich saddles and
housings, carrying hawks on their wrist, attended by an
immenaa train of attendants. The bells of the churches
were rung as they passed. They associated on equal terms
with laymen of the highest distinction, and shared all their
pleasures and pursuits. This rank and power was, how-
ever, often used most beneficially. For instance, we read
of Whiting, the last Abbot of Glastonbury, judicially mur-
dered by Henry VIII., that his house was a kind of well-
ordered court, where as many a.s 800 sons of noblemen and
' ^^ '^wortb, the fourth abbot of St Alban's, circa 930, U charged by
McKl.'.T Praia with adopting the attire at a epottsmao.
gentlemen, who had been sent to him for virtnoos educO'
tion, had been brought up, besides others of a meaner rank,
whom he fitted for the universities. His table, attendance,
and officers were an honour to the nation. He would
entertain as many as 500 persons of rank at one time,
besides relieving the poor of the vicinity twice a-wetk.
He had his country houses and fisheries, and when ho
travelled to attend Parliament his retinue amounted to
upwards of 100 persons. The abbots of Clugny and
Vendome were, by virtue of their office, cardinals of the
Romish Church.
In process of time the title abbot waa improperly tmns-,
ferred to clerics who had no connection with the monutio
system, as to the principal of a body of parochial
clergy; and under the Carlovingians to the chief chaplain
of the king. Albas Curia:, or military chaplain of the em^
peror. Abbot Castrensis. It even came to be adopted by,
purely secular officials. Thus the chief magistrate of. the
republic at Genoa was called Abbas PupuU. Ducange, id
his Glossary, also gives us Abbas CanqMiiilU, Clochetiii
Palatii, Scholaria, iic.
Lay abbots, so called, had their origin in the system of
commendation, in the 8th centiiry. By this, to meet any,
(,Teat necessity of the state, such as an inroad of the Saraj
cens, the revenues of monasteries were temporarily com-
mended, i.e., handed over to some layman, a noble, or even
the king himself, who for the time became titular abbot.'
Enough was reserved to maintain the monastic brother^
hood, and when the occasion passed away the revenues
were to be restored to their rightful owners. The estites,'
however, had a habit of lingering in lay hands, so that in
the 9th and 10th centuries most of the sovereigns and
nobles among the Franks and Burgundians were titular
abbots of some great monastery, the revenues of which
they applied to their own purposes. These lay-abbots
v!eTe stylcA Abbacomitea oi Abbates Milites. Hugh Capet,
before his elevation to the throne, as an Abbacomet held
the abbeys of St Denis and St Germain, in commendam.
Bishop Hatto, of Montz, a.d. 891-912, is said to have held
12 abbeys in commimdam at once. In England, as wo see
from the Acts of the Council of Cloveshoc, in the 8th
century, monasteries were often invaded and occupied by
laymen. This occurred sometimes from the monastery
having voluntarily placed itself under the protection of a
powerful layman, who, from its protector, became its op-
pressor. Sometimes there were two lines of abbots, one of
laymen enjoying the lion's share of the revenues, another
of clerics fulfilling the proper duties of an abbot on a small
fraction of the income. The gross abuse of lay commen-
dation which had sprung up during the corruption of
the monastic system passed away with its reformation in
the 10th century, either voluntarily or by compulsion..
The like abuse prevailed in the East at a later period.
John, Patriarch of Antioch, at the beginning of the 12th
century, informs us that in his time most monasteries had
been handed over to laj-men, leneficiarii, for life, or for
part of their lives, by the emperors.
In conventual cathedrals, where the bishop occupied
the place of the abbot, the ftmctions usually devolving on
the superior of the monastery were performed by a prior.
In other convents the prior was the second officer next to
the abbot, representing him in his absence, and fulfilling
his duties. The superiors of the cells, or small monastic
establishments dependent on the larger monasteries, were
also caDed priors. They were appointed by the abbots,
and held office at their pleasiu-e.
Authorities: — Bingham, Oi^V^jne*/ Ducangfe, Glossary;
■Herzog, Realwbrterbuch ; Eohertson, Ch. Hist. ; Marten e,
De Antiq. Monnst. Ritibxia , Montalcmbcrt, ilonlts of the
'•Vc^t , (1 V.)
ABBOT
25
ABBOT, Chaeles,. speaker of theHonse of Commons
/Vom 1802 to 1817, afterwards created Lord Colchester.
ied CoLCfiKSTEB.
ABBOT, Geoege, Arclibishop of Canterbury, -was bom
October 19, 1562, at Guildford in Surrey, where liis father
iras a cloth-worker. He studied at BaUiol CoUege, Oxford,
and was chosen Master of University College in 1597.
Pe was three times appointed to the office of Vice-Chan-
cellor of the University. When in 1604 the version of the
Bible now in use was ordered to be prepared, Dr Abbot's
name stood second on the Hat of the eight Oxford divines
to whom was intrusted the translation of the New Testa-
jinent, excepting the Epistles. In 1608 he went to Scotland
with the Earl of Dunbar to arrange for a union between
the Churches, of England and Scotland, and his conduct in
that negotiation laid the foundation of his preferment, by
attracting to him the notice and favour of the king. With-
out having held any parochial charge, he was appointed
Bishop of Lichfield and Coventry in 1609, was translated
to the see of London a month afterwards, and in less
than a year was made Archbishop of Canterbury. This
rapid preferment was due as much perhaps to his flat-
tering his royal master as to his legitimate merits. After
his elevation" he showed on several occasions, firmness
and courage in resisting the king. In the scandalous
divorce suit of the Lady Frances Howard against the Earl
of Essex, the archbishop persistently opposed the dissolu-
tion of the marriage, though the influence of the king and
court was strongly and successfully exerted in the opposite
the king, and ordered to be read in all the churches, per-
mitting sports and pastimes on the Sabbath, Abbot had
the courage to forbid its being read at Croydon, where he
happened to be at the time. As may be inferred from
the incident just mentioned. Abbot was of the Protestant or
Puritan' party in the Church. Ho was naturally, therefore,
a promoter of the match between the Elector Palatine and
the Princess Elizabeth, and a firm opponent of the projected
marriage of the Prince of Wales with the Infanta of Spain.
This policy brought upon him the hatred of Laud and the
court. The king, indeed, never forsook him ; but Buck-
ingham was his avowed enemy, and he was regarded with
dislike by the Prince of Wales, afterwards Charles I.
In 1622 a sad misfortune befell the archbishop while
hunting in Lord Zouch's park at Bramzill. A bolt from
his cross-brow aimed at a deer happened to strike one of
the keepers, who died within an hour, and Abbot was so
greatly distressed by the event that he fell into a state of
settled melancholy. His enemies maintained that the fatal
issue of this accident disqualified him for his office, and
argued that, though the homicide was involuntaiy, .the
sport of huntiug which had led to it was one in which no
•clerical person could lawfully indulge. - The king had to
refer the matter to a commission of ten, though he said
that " an angel might have miscarried after this sort." A
■decision was given in the archbishop's favour; but to pre-
vent disputes, it was recommended that the king Bhould
formally absolve him, and confer his office upon him afiew.
After this the archbishop seldom appeared at the council,
chiefly on account, of his infirmities. He attended the
king constantly, however, in his last illness, and performed
the ceremony of the coronation of Charles I. A pretext
■was soon found by his enemies for depriving him of all his
functions as primate, which were put in commission by
the king. This high-handed procedure was the result of
Abbot's refusal to license a sermon preached by Dr Sibthorp,
iu which the king's prerogative was stretched beyond con-
•Btitutional limits. 'The archbishop had his powers restored
to him shortly afterwards, however, whon the kii:g found
it absolutely sicccsaary to summon a Pai'liamcnt. His pre-
8en''.e being unwelcome at court, he lived from that time
in "retirement, leaving Laud and his party in undisputed
ascendency. He died, at Croydon on the 5th August 1633,
and was buried at Guildford, his native place, where he had
endowed an hospital with lands to the value of £300 a year.
Abbot wrote a large nimiber of works; but, with the excep-
tion of his Exposition on the Prophet Jonah (1600), which
was reprinted' in 1845, they are now little known. His
Geography, or a Brief Descriptimt, of the Whole World,
passed through numerous editions.
ABBOT, Geokgb, known as " The Puritan," has been
oddly and persistently mistaken for others. He has been
described as a clergyman, which he never was, and as son
of Sir Morris Abbot, and his wi-itings accordingly entered
in tLo bibliographical authorities as by the nephew of
the Arch'oishop of Canterbury. One of the sons of Sir
Morris Abbot was, indeed, named George, and he was
a man of mark, but the more famous George Abbot
was of a difi'erent family altogether. He was son or
grandson (it is not clear which) of Sir Thomas Abbot,
knight of Easington, East Yorkshire, having been bom
there in 1603-4, his mother (or grandmother) being
of the ancient house of Pickering. He married a
daughter of Colonel Purefoy of Caldecote, Warwickshire,
and as his -monument, which may still be seen in the
church there, tells, he teively held it against Prince
Rupert and Maurice during the civil war. He was a
member of the Long Parliament for Tamworth. Aa a
layman, and nevertheless a theologian and scholar of
rare ripeness and critical ability, he holds an almost
unique place in the literature of the period. His Whole
Boolce of Job Paraphrased; or made easy for any to tinder-
stand (1640, 4to), is in striking contrast, in its concinnity
and terseness, with the prolixity of too many of the Puritan
expositors and commentators. His ^ddic-ice Sablathi(l&il,
8vo) had a profound and lasting ^influence in the long
Sabbatic controversy. His Brief Notes vpon the Whole Book
of Psalms (1651, 4to), as its date shows, was posthumous.
He died February 2, 1648. (MS. collections at Abbey-
viUe for history of all of the name of Abbot, by J. 1".
Abbot, Esq.,F.S.A., Darlington; Dugdale's Antu/itities of
Warwickshire, 1656, p. 791; Wood's Athenae (Bliss), s. v.;
Cox's Literature of the Sabbath; Dr James Gilfillan on
The Sabbath; Lowndte, Bodleian, B, Museum Catal.
a. v.) (a. b. g.)
ABBOT, EoBEET. Noted as this Puritan divine was in
his own time, and representative in various ways, he has
hitherto been confounded with others, as Eobert Abbot,
Bishop of Salisbury, and his personality distributed over
a Robert Abbot of Cranbrook; another of Southwick,
Hants; a third of St Austin's, London ; while these succes-
sive places were only the successive livings of the one
Robert Abbot. He is also described as of the Archbishop's
or Guildford Abbots, whereas he was iu no way related,
albeit he acknowledges very gratefully, in the first of his
epistles-dedicatory of A Hand of Fellowship to Uelpe Keeps
ovt Sinne and Antichrist (1623, 4to), that it was from the
nance," as well as "best earthly countenance" and "fatherly
incouragements." The worldly maintenance was the pre-
sentation to the vicarage of Cranbrook in Kent, Of which
the archbishop was patron. This was in 1616. He had
received bis education at Cambridge, where ho proceeded
M.A., and was afterwards incorporated at Oxford. . In
1639,'in the ej)istle to the reader of his most noticeable
book historically, his Triall^of our Chutch-Forsakers,
he tells us, " I have lived noW, by God's gratious dis-
pensation, above fifty years, and in the place of my
allotment two and twenty fuU." The, former data
carries us back to 1088-89, or perhaps 1587-88 — the
I ~ A.
26
A B B — A U 13
" AnDftda"year — as his birth-«ime; the latter to lClG-17
Sut supra). In hia lite Thank/ull London and her Sislera
1G2C), he deacribeo himeeli as formerly "assistant to a
reverend divine .... now with God," and the name on
the margin is " Master Haiward of Wool Church." This
was doubtless previous to his going to Cranbrook. Very
remarkable and effective was Abbot's ministry at Cran-
brook, where the father of Phiueas and Giles Fletcher was
the first " Reformation" pastor, and which, relatively small
as it is, is transfigured by being the birth-place of the poet
of the " Locusta)" and "The Purple Island." His paribh-
ioners were as his own " sons and daughters" to him, and
by day and night he thought and felt, wept and prayed, for
them aud with them. He is a noble specimen of the rural
clergyman of his age. Puritan though ho was in his deepest
convictions, he was a thorough Churchman a.s toward Non-
conformists, e.g., the Brownists, with whom he waged stem
warfare. Ho remained until 1043 at Cranbrook, aud then
chose the very inferior living of Southwick, Hants, as be-
tween the one and the other, the Parliament deciding
against pluralities of ecclesiastical offices. Succeeding the
" e.xtruded " Udall of St Austine's, Abbot continued there
until a good old aga. In 1657, in the Warning-piece, he
is described as still " pastor of Austine's in London." He
disappears silently between 1657-8 and 16G2. Robert
Abbot's books are distinguished from many of the Puritans
by their terseness and variety. (Brook's Puritatm, iii
182, 3; Walker's Sufferings; Wood's J</tfntB (Bliss); Cata-
logus Impressorxim Librurum in Bibtiotlieca JBodleiana, a. v.;
Palmer's Nonconf. Hem., iL 218.) (.v B. G.)
ABBOTSFORD, the celebrated residence of Sir Walter
Scott, situated on the south bank of the river Tweed, about
three miles above Melrose. The nucleus of the property
was a small farm of 100 acres, with the " inliarmonious
designation" of Clarty Hole, acquired by Scott on the lapse
of his lease (1811) of the neighbouring house of A.shestiel.
It was gradually increased by various acfiuisitions, the last
and principal being that of Toftficld (afterwards named
Huntlyburn), purchased in 181 7. The present new house was
then commenced, and was completed in 1824. The general
ground-plan Is a parallelogram, ' with irregular outlines —
one side overlooking the Tweed, and the other facing a
courtyard ; aud the general stylo of the building is the
Scottish baronial. Scott had ouly enjoyed his new resi-
dence one year when (1825) he met with that reverse of
fortune (connected with the failure of Ballantyne and
Con.stable), which involved the estate in debt. In 1830,
the library' and museum \vere presented as a free gift by
the creditors; and after Scott's death, which took place at
Abbotsford in September 1832, a committee of friends
subscribed a further sum of about X8000 towards the same
object. The property was wholly disencumbered in 1847,
by Mr Cadell, the publisher, accepting the remaining
claims of the family over Sir Walter Scott's writings in
requital of liis obligation to obliterate the heritable bond on
the property. The result of this transaction was, that not
only was the estate redeemed by the fruit of Scott's brain,
but a handsome residue fell to the publisher. Scott's only
son Walter (Lieutenant-Colonel 15th Hussars) did not live
to enjoy the property, having died on hb way from India
in 1847. Its subsequent possessors have been Scott's
son-in-law, J. G. Lockhart, and the latter's son-in-law,
J. R Hope Scott, Q.C., whose daughter (Scott's great-
granddaughter) is the present proprietor. Mr Lockhart
died at Abbotsford in 1854. — See Li/e of Scott, by J. G.
Lockhart; Abbotsford and Newslead Abbey, by Washing-
ton-Irving; Abbotsford Nolanda in Gentleman's Mag.,
' TliB Catilotruo of the Library at Abbotsfoid forms vol. IxL of the
B&imatf a» Club publications. ^
April and May 1869; The Lands of SeoCt, by James F.
Hunnewell, cr. 8vo, 1871; iSeott Loan Exhibition Catci
luyue, 4to, 1871.
ABBOTSFORD CLUB, one of the principal printing
clubs, was founded in 1 834 by Mr W. B. D. D. Turnbull, and
named in honour of Sir Walter Scott. Taking a wider
range than its predecessors, the Bannatyne and Maitland
Clubs, it did not confine its printing (as remarked by Mr
Lockhart) to works connected with Scotland, but admitted
all materials that threw light on the ancient history of
literature of any country, anywhere described or discussed
by the Author of Wavcrloy. The club, now dissolved, con-
sisted of fifty members ; aud th» publications extend to 3 t
vols, quarto, Usucd during the years 1835-18C4.
ABBREVIATIOX, a letter or group of letters, takca
from a word or words, and employed to represent them for
the sake of brevity. Abbreviations, both of single words
and of phrases, having a meaning more or less fijccd and
recognised, are common in ancient writings and in3crij>
tions, and very many are in use at the jjresent time. A
distinction is to be observed between abbreviations and the
contractions that are frequently to be met with in old
manuscripts, aud oven in early printed books, whereby
letters are dropped out here and there, or particular collo-
cations of letters represented by somewhat arbitrary symbols.
The commonest form of abbreviation is thiJ substitution for
a word of its initial letter ; but, with a view to prevent
ambiguity, one or more of the other letters are frequently
added. Letters are often doubled to indicate a plural or a
superlative.
I. Classical Abbreviations. — The following lisl con-
tains a selection from the abbreviations that occur in the'
writings and inscriptions of the Romans : —
A.
A Absolve, .£dill9, M&, Ager, Ago. AJo, Amicoa, Annus,
Antiquo, Auctor, Auditor, Augustus, Aulus, Auruuv
Aut.
A. A. Mi alicDum, Ante audita, Apud agrom, Auium aig«utuio^
AA. Augiisti. AAA. Au^uisti tres.
A.A.A.F.F. Auro argcnto ajreuando foriundo.^
A. A. V. Alter ambove.
A.C. Acta causa. Alius civis.
A. D. Ante diem ; e.g., A. D. V. Ante diom •{Uialuni.'
.V. D. A. Ad dandos agros.
.ED. Jules, .£<iUis, .£dilita3.
i£M. and AIM. .^uiilius, .£mitia.
^.R. jErarium. jEH. P. £re publlcu,
AF. Actum fide, A\ili filius.
AG. Ager, Ago, Agr^>pa.
A O. Aniino grato, Aulus Gclliua.
A. L.'E. and A. L. £. Arbitrium litis cealiiuaj.dji
ANN. Ami&les, Anni, Amiona.
ANT. Ante, Ajitoniua.
A. O. Alii omncs, Amico optimo.
AP. Appius, Apud.
.V. P. Ad pedes, iEdilitia potestate.
AP.F. Auro {or argento) publico feriundo.
A. P.M. Amico posuit monumentum, Annoruin plus minus;
A. P. R.C. Addo post Romam conditam.
jVRG. Argentum.
Alt. V.V.D.D. Aram Totam volens dedicavit, Arma votivudouutfedjit-
AT. A tsrgo. Also A TE. and A TEB.
A.T. M. D. 0. Aio to mihi dare opertere.
AV. Augur, Augustus, Aurcliua.
A. V. Annos visit.
A. V.C. Ab urbo condita.
AVG. Augur, Augustus.
AVG3. AwgasXHgenerally of two). A'VGGG. Augast) tres.
AVT. Pfi.U. Auctoritas provincise Romanoi'um.
B.
B. Balbius, Balbus, Beatua, Bene, Beneficiarios, Beneficiuic,
Bonus, Brutus, Bustum.
B. /orV. B8ma,BiTU3, Butit
B.A. Bixit annos. Soma au^uriis. Bonus amabilis.
' Doscnbing the fonctioa of the iriunvin numUaUa.,
ABBREVIATION
27
HR. orB. B. Bene bene, i.e., optime, Optimus. '
B. D. BonsB dose, Honiim datum.
B. DD. Bonis deabua.
B. D.S. M. Bene de se merenti.
B. F. Bona femina, Bona fidcg, Bona fortuna, Bonnm factum.
(I.J. Bona femina, Bona filia.
H, H. Bona hereditaria, Bonomm heres.
B. i. Bonura judicium. B. 1. 1. Boni judicia judicium,
B. K. Beats memoriae, Bene merenti.
B. K. Bona nostra, Bonum nomen.
li N.H.I. Bona hie invenies.
B. P. liona patema, Bonomm potestas, Bonum publicum.
B.Q. Bene quiescat. Bona quiesita.
B.RP.N. Bono reipublicae-natua.
BUT. Britannicus.
B.T. Bonomm tutor, Brevi tempore,
B. V. Bene vale, Bene vixit, Bonus vir.
B. V. v. Balnea vina Venus.
BX. Bixit, for vixit.
C.
C Cfflaar, Caius, Caput, Causa, Censor, Civis, Cohors, Colonia,
ComitiaKs (dies), Condemno, Consul, Cum, Curo,
Custos.
p. Caia, Centuria, Cum, the prefix Con.
C. B. Civis bonus, Communo bonum, Conjugi benemerenti, Cui
bono.
C.C. Calumni.'e causa, Causa cognita, Conjugi carissimae, Con-
eilium cepit, Curiro consulto.
C. C. C. Calumniae cavendse causS.
C.C. F. Caisar {or Caius) curavit faciendum, Caius Caii filiui.
caw. Clarissimi viri.
CD. Caesaris decreto, Caius Decius, Coraitialfbus diebua,
CICS. Censor, Censores. CESS. Censorep
C.F. Causa fiducise, Conjugi fecit, Curavit faciendum.
C. H. Custos heredum, Custos hortonim.
C.I. Caius Julius, Consul jussit, Curavit judex.
CIj. Clarissimus, Claudius, Clodlus, Coloiii.k
CL. ^. Clarissimus rir, ClypeuTn vovit,
C» AL Caius filarius, Causa mortis.
CN. CnfcuB.
COH. Coherea, Cohors.
COL. CoUega, Collegium, Cgloma, Columua.
COLL. Collcga, Coloni, Colonrre.
COM. Comos, Comitium, Compnratum,
CON. Conjux, Consensus, Consiliarius, Cons\il, Consularis,
COR. Cornelia (tribus), Cornelius, Corona, Corpus.
COS. Consiliarius, Consul, Consulares. COSS. Consulcs.
C.P. Carissimus or Clarissimus puor, Civis publicus, Curavit
ponendum.
C. R. Caius Kufus, Civis Romanus, Curavit reficiendum.
C3, Caisar, Communis, Consul.
C.V. Clarissimus or consularis vir.
CVR. Cura, Curator, Curavit, Curia.
D.
D. Dat, Dedit, &c., De, Dccimus, D^cius, Decretum, Decurin,
Deus, Dicit, Jtc, Dies, Divus, Dominus, Domu.'*,
Donum.
DC. Decurio colonic, Diebus comitialibus, Divus Ctesar.
D. D Dea Dia, Decurionum decreto, Dedicavit, Deo dedit, Dont-
dedit.
D. D.D. Datum decreto decurionum, Dono dedit dedicavit.
I>. E.R, De earc.
b ES. Designatus.
D.I. Dedit iraperator, Diis immortallbus, Diis inferis.
D. I.M. Deo iuvicto ilithrx, Diis inferis llanibus.
D.M. Deo Magno, Dlgntis memoria, Diis Manibus, Dolo malo.
D. 0. >L Deo Optimo Maximo.
D. P.S. Dedit proprio sumptu, Deo pqrpetuo sacrum, De pccunia
sua.
E.
Ejus. Eques, Erexit, Ergo, Est, Et. Etiam, Ex.
iEgor, Egit, Egregius.
EgrogiiR racmorice, Ejosmodi, Erexit monumentura.
Equitum raagister,
Ea res agitor.
F.
Fubius, Facere, Fecit, fcc, Familia, FiiBtus (dies\ Felix.
Femina, Fi^es, Filius, Flamon, Foi-tuna, Frator, Fuji.
Functus.
Faciendum curavit, Fidei commi3<*um, Fiductte causa,
Fidera dedit, Flamcn Dialis, Fraude donavit.
Forro flamma fame, FoMior fortxma fato.
Filius, FlameH, Flaminius, Flavins.
Paveto Unguis, Fecit libcfis, Felix liber.
Foram, Fronte, Frumentorius.
Foruui Iluniauum.
E.
RO.
R. M.
EQ. M.
E. U. A.
F.C.
K.D.
F.F.F.
FL.
F.L
KR.
F.R.
G. Gains ( = Cains), Gallia, Gaudium, GeTlina, Gemina, Gena,
Gesta, Gratia.
G.F. Gemina fidelis {%pplkd to a legion). 5o G.P.F. Gemina
pia fidelis.
GL. Gloria.
GN. Genius, Gens, Genus, Gnaeus (^Cnaeofl),
G. P.R. Genio populi Romani.
H.
H. Habet, ITeres, Hie, Homo, Honor, Hora.
HER. Heres, Herennius. HER. and HERC. Hercules,
H.Ij. Hac lege, Hoc loco, Honesto loco.
H.M. Hoc monumentum, Honesta mulicr, Hora mala,
H.S.E. Hie Eepultus est, Hie situs est.
H.V. Hsec ui-bs, Hie vivit, Honeste vixit, Honestus vir.
I.
I. Immortalis, Imperator, In, Infra, Inter, Invictus, Ipae;.
Isis, Judex, Julius, Junius, Juniter, Justus.
IA_ Jam, Intra.
I.e. JuJius Cssar, Juris Consultum, Jus civile.
ID. Idem, Idus, Interdum.
I.D. Infens diis, Jovi dedicatum, Jus dicendum, Jussu DeL
I. D.M. Jovi dco magno.
I. F. In fovo, In Ironte.
I. H. Jacet hie, In honestatem, Justus homo.
IM. Imago, Immortalis, Immunis, Impensa.
IMP. Imperator, Imperium,
I. CM, Jovi Optimo maximo.
I. P. In publico. Intra provinciam Justa persona.
I.S.V. r. Impensa sua vivus posuit
K.
K. Kceso, Caia, Calumnia, Caput, Carus, Castra.
K., EAL.. arul KL. Kalends.
l:
L. Laelius, Legio, Lex, Libcns Liber, Libra, Locus, LoUiua,
Lucius, Ludus.
LB. Libens, Liberi, I^ibertus.
L.D.D.D. Locus datus decroto decurionum.
LEG. Legatus, Legio.
LIB. Liber, Liberalitas, Libertas, Libertus, LibrariuB.
LL. Leges, Libentissime, LibertL
L.M. Libens merito, LocuS monumrnti.
L.S. Laribus sacrum. Libens solvit. Locus saoer.
LVD. Ludus.
LY.P.F. Ludos publicoa fecit.
M. Magister, Maglsti-atus, Jlagnus, Manes, Marcus, Marina^
Marti, Mater, Mcmorin. Mcnsis, Miles, Monumentmn,.
Mortuus, Mucins, ilulier.
M*. Manius.
M. D. Jlagno Deo, Manibus diis, Matri deum, Merenti derbt
ME3. Mensis. MESS, iicnscs.
M. F. Mala fides, Ma-rci filius, Monumentum fecit,
M.I. Matri Idae.-e, Matri Isidi, ilaximo Joyi.
MNT. and MON. Moneta.
M. P. Male positus, Monumentum posuit.
M.S. Manibus sacrum, Memorire sacrum, ManUficriptum.
MVN. Municeps, or municipium ; so also MN., MV., and
MVNIC.
M.T.S. Marti ultori sacrum, Mciito votum solvit
N.
N. Katio, ^atus, Nefastus (dies), Ne^ws, Keptunus, Nero,
Komen, Non, IJonte, Nostcr, Kovu3, Nuraen, Numo-
rius, Numerus, Nummus.
N"EP. Kepos, Neptunus.
K.F.C. Nostra fidei commissum.
X.L. Kon licet, Non liquet, Non loDgO.
N.M.V. Nobilis mcmoriaa vir.
NN. Nostri. NN., NNO., ffjiiNKR. Nostronim.
NOB. Nobilis. NOB., NOIiK., a»rf NOV. Novembris.
N.P, Nefastus primo (i.e., priore parte dici), ]^on potest.
0.
0. Ob, OfTirium, Omnis, Oportot, Optimus, Opus. Oaso.
OR. Obiit, Obiter, Orbis.
O.C.S. Ob civcs scrvatos.
O.H. F. Omnibus honoribus functus
O.H.S.S. Ossa hie siti sunt.
OR. Hora, Ordo, Omaraentum.
O.T.B.O Oasa tua bene quitscnnt.
P.
P. Pots, Passus, Pater, Pr.tronus, Pax, Porpctuns, Pes. Pius,,
Plebs, Pondo, Populus, Post, l*osuit, Prases, Pra:tor,
Primus, Pro, Provincia, Publicus, Publius, Pucr.
P.C. Pactum conventum, Patrcs conscripti, Pecunia constitutor
Ponendum cuiarit, Postconsulatum, PotcstatecousoriA.
M.
28
A B B K E V I A T I O N
p.p. Pl» (idelis, Pius felix, Pnomissa fidos, Publii filius.
P. M. Pisd memoris. Plus minun, Pontifex maxirous.
P.P. Pater patmtua. Pater patriaj, Pccunia publica, P'^posihis,
Primipilus, Proprsetor.
PR, Pmwea, Prtetor, Pridie, Prjnoops.
P. R. Pormiaau roipublica, Populus Uomanus.
JMI.C. Post Jiomam couditam.
PR. PR. PiKfectus praetorii, Proprsetor.
P. 8. Pecunia sua, Plebiscitnm, Proprio snmptu, PnbliciB saluti.
P. V. Pia victrii, Prtcfeotua urbi, Pnnstantisdimua vij.
Q.
Q. Quaestor, Qaando, Quautufl, Que. Qui, Qoinquennnlis,
Quintus, Quiritos.
Q. I.S.3. Qum infra scripta sunt ; so Q. 8. 8. 8. Quie supra. 4c.
QQ. Quajcumiuo, Quinqueonalia, Quoque.
Q. U 'juai.itor rnipublic;^.
R.
R. Recto, Res. Respnblica, Betro, Roi, Rips, Boma, Ronmnna,
F.iJ'us, Rursua.
R. C. Eo-nana ci vitas, Uomanus civia.
Rii.SP. and RP. HcspuUioa.
KET. P. and RP. Retro nei'ea.
S.
8k Sacrum, Scriptus, Semis, Senatps, Scpultns, Serriua,
Sorvua, Soxtua Sibi, Sine, Situs, Solus, Solvit, .Sub,
Suus.
SAC. riacerdos, Sacrificium, Sacrum.
S.C. Scnatus consultiini.
8,0. Sacrum diia, Salutcm dicit, Senatna decrcto, Sentontiam
dcdit
S.D.jr. S'lcnim diis Manibus, Sine dolo mala
SKH. Rervius, Rervus.
9. E.T.L. Sit ei terra levia.
SN. Senatus, Sententia, Sine.
S. P. Sacerdos perpetua. Sine peconia, Sua pecnnia.
S. P.Q.R, Senatus populusque Romanus.
S.S. Sanctisaimus senatus. Supra acriptum.
S.V.B.E.E.Q.V. Si vales bone est, ego quidem valco.
T.
T. Terminus, Testamentum, Titus, Tribunua, Tu, Tnrma,
Tutor.
TB., Tl., and TIB. Tiberius.
TB., TR., and TRB. Tribunus.
T.F. Testamentum fecit, Titi filios, Titnlam fecit, Titus
Flavius.
TM. Terminus, Teatamentum, Thermse.
T. P. Torminum posuit, Tribunicia potestate, Tribnnns plebis.
TVL. Tullius, Tullua.-
V.
V. "Urbs, TTsas, Uxor, Tale, Vertia, Testalia, Tester, Tir,
Tivus, Tixit, Tolo, Totum,
7.A. Teterano assignatus, Vixit annoa,
T.C. Tale conjux, Vir clarissimua, Tir consularis.
V. E, Terum etiam, Tir egregius, Tisum est.
T.F. ITsHS fructus, Terba fecit, Tivus fecit
T. P. Urbis prasfectus, Vir perfectissimus, Tivus posuit.
V. R, Urbs Roma, Uti rogas, Totum reddidit
n. Medlbval Abbreviations, — Of the different kinds
of abbreviations in use in the middle age?, the following
are examples: —
A.Htf. Ave Maria,
B.P. Beatus Paulus, Beatna Petrus.
CC. Carissimua {also plur, Carissimi), Clarissimua, Circum.
D. Deus, Dominicus, Bux.
i). N. PP. Dominua noster Papa,
FF. Felicissimua, Fratres, Pandectffl (proi. for Or. n).
I.e. or I.X. Jesus Cbristua.
I.D.N. In Dei nomine.
KK. Karissimua (or -mi).
MM. Hagistri, Martyres, Matrimoniom, Meiitissimas.
O.S.B. Ordinis Sancti Benedicti.
PP. Papa, Patres, Piissimua.
R,F. Rex Francorum.
R. P. D. Reverendissimus Pater Dominos.
S. C. M. Sacra Ccesarea Majestaa.
S. M. E. Sancta Mater Ecclesia.
R.M.AL Sancta Mater Maria.
S.R.1. Sanctum Roman um Imperium.
8.T. Sanctitos Testra, Sancta Tirgo.
T. Tenerabilis, Tenerandua.
T.R.P. Testra Reverendissima Patemitaa.
• IIL Abbbeyiations now in use. — The import of these
will often be readily understood "from the connection in
which they occur. There ia no occasion to explain her«
the common abbreviations used for Chi-istian names, books
of Scripture, months of the year, points of the compass,
grammatical and mathematical terms, or familiar Titles,
Uko " Mr;" Ac
The ordinary abbreviations, now or recently in use, may
be conveniently classified under the folloising headings :— <
1. Abbreviated Titles and Designxtioks.
A. A- Associate of Arta.
A. B. Able-bodied scainan.
A. M. (ATiium Mngister), Master of Atrts.
A. R.A. Associate of tbo Royal Academy
A. U.S.A. Associate of the Royal Scottish Academy.
B. A. Bachclof of Arts.
li. C. L Bachelor of Civil La%
B. D. Bachelor of Divinity.
B. LiL. Bachelor of Laws.
B.Sc Bachelor of Sciencs.
C. Chairman.
C.A. Chartered Accountant
C. B. Companion of the Bath.
C. E. Civil Engineer.
C. M. {Chirurgix Mayistcr), Master in Surgery.
C. M.G. Companion of St Michael and St George,
C. S. I. Companion of the Star of IndijL
D.C.L. DoctorofCivil Law.
D.D. Doctor of Divinity.
D. Lit Doctor of Literature.
D. AL Doctor of Medicine [Oxford].
D.Sc Doctor of Science.
Ebor. (i.'6ora«Tur«), of York.*
F.C.S. Fellow of the Chemical Society.
F. D. {Fidn Defenaar), Defender of the Faith.
F. F. P. S. Fellow of the Faculty of Physicians k Surgeons [Chisgo*. ]
F. G. S. Fellow of the Geological Society.
F.K.Q.C.P.l. Fellow of King and Queen's College of Physicians
in Ireland.
F.L.S. Fellow of the Linnxan Society.
F. M. Field Marshal
K. P. 8. Fellow of the Philologies} Society.
F. R.A.S. Fellow of the Royal Astronomical Society.
F. K.C. P. Fellow of tho Royal College of Physicians.
F.R.C.P.E. Fellow of tho Royal College of Physicians of E>lin-,
burgh.
F.R.C.S. Fellow of the Rcyal College of Sareeons.
F. R.G.S. Fellow of the Royal Geographical Society.
F. R. S. FeUow of the Royal Society.
F.R.S.E. Fellow of the Royal Society of Edinburgh.
F. R.S.L. FcUow of the Royal Society Sf Literature.
F.S. A. Fellow of the Society of Antiquai'ies.
F. S. S. Fellow of the Statistical Society.
F. Z. S. Fellow of the Zoological Society.
G.C.B. Knight Grand' Cross of the Bath.
G.C.H. Knight Grand' Cross of Hanover.
G.C.M.G. Knight Grand Cross of St Michael and Pt George.
G. C.S.I. Knight Grand Commander of the Star of India.
H.RH. His (or Her) Royal Highness.
J. P. J'istice of the Peace.
J. U. D. (Juris utriusque Dodo/), Doctor of Civil and Canou I.»w.
K. C.S.I. Knight Commander of the Star of India.
K.C.B. Knight Commander of the Bath.
K. G. Knight of the GarUr.
K. P. Knight of St Patrick.
K.T. Knight of the Thistle.
L.A.n. Licentiate of the Apothecaries' HalL
L.C.J. Lord Chief Justice.
LL. B. (Z^gum Baccalawreus), Baclftlor of Laws.
LL. D. {Legum Doctor), Doctor of Laws.
LL. M. {Legum Magistcr), Master of Laws.
L. R. C. P. Licentiate of the Royal College of Physicians,
L. R. C. S. Licentiate of the Royal College of .Surgeons.
L. S. A. Licentiate of the Apothecaries Society.
W.A. Master of Arts.
M. B. {Medicince Baccaiaurcus), Bachelor of Medicine.
M. C. Member of Congress.
M.D. {Mcdicina Doctor), Doctor of Medicine.
M. P. Member of Parliament.
M. R. C. P. Member of the Royal College of Physicians.
.\I. R.I.A. Member of the Royal Irish Academy.
Mus. B. . Bachelor of Music.
* An archbishop or bishop, in writing his signature, substitutes Iv
his surname the name of his see ; thus the prelates of Canterbury, York,
tford, London, &c. , subscribe themselves A. 0. Cantuar.,, W. Eber.
J. F. Cion., J. London. i:c.
ABBKEVIATION'
29
bar.
bus.
c
acre.
barrel.
busheL
cent.
c. (or cub.) ft &c cubic foot,
&c.
htrndredweight.
{d€narizis), penny.
degree.
dra^bm or aram.
pennyweighi,
iranc.
florin.
foot.
furlong.
galloa
grain-
h. 01' hr. hour,
in. iucn.
kilo, kilometre.
cwl
d.
deg.
dr.
dwt
f.
fl.
ft.
fur.
gaL
miuim.
month.
nail-
ounce,
peck.
pole.
pint.
quarter.
quart,
ro. rood."
Rs. ' rupees.
&. or / {solidua), shilling.
3. or sec. second.
sc. or scr. scruple,
sq. f*- &c. square foot, &c,
St. stone,
yd- yard.
Mufl. D. Doctor of Musits.
N.P, Notary Public.
P.C. Vxivy Councillor.
Ph.D. {PhilosophicB Doctor), Doctor of Phiio3<^hy.
P.P. Parish Priest.
P.R.A. President of the Eoval Academy.
Q.CX Queen's Counsel.
R, {Hex, Regina), King, Queem
R.E. Royal Enginesra.
Reg. Prof. Regius Professor.
R.M. Royal Marines.
R.N. Royal Navy.
S. or St. Saint.
8.S.C. Solicitor before the Supreme Courts [of Scotland].
S.T.P. {Sacrosanci(K Theologice Professor)^ Profesror of Sacred
Theology.
V.C. Vice-Chancellor. " ictoria Cross.
V.G. Vicar-Generak
V.S. Veterinary Surgeon. |
W.S. Writer to the Signet fin Scotland]. Equivalent to Attortwy.
2. Abbreviations denoting Monies, Weights, and
Measuees : — ^
L. , * £,' or Z. {libra), pound
(money),
lb. or lb. ^libra), pound (weight),
m. o^ mi. mile ; minute.
m-
mo
na.
oz.
pk.
ro.
pi.
q>
qr.
qt.
3. Miscellaneous ABBEEviATiONa,
A. Accepted.
A.C. {Ante Christum), Before Christ.
Eicc., &/c., or acct. Account.
A. D. {Anno Domini), In the year of our Lord.
A. E.I.O.U. Austrise est imperare orbi universo.'w Alles Erdreh'h
1st Oesterreich Uuterthan.
SLi. or iEtat. {^tatia [anno]). In the year of his age.
A.H. {Anvj) Eegirce)^ In the year of the Hefnra (the Mohammedan
era).
A. M. (-471710 Mutidi), In the year of the world.
A.M. {Ante meridiem), Forenoon.
Anon. Anonymous.
A.U.C I Anno urbis condilft), m the year from the building of tlie
city (i.ff., Rome.)
B.C. Before Christ.
C. or Cap. {Caput), Chapter.
cent* {Ce)itum), A hundred, //-cf/tttrnf/j/ £100.
Ct {Confer), Compare.
Ch- or Chap. Chapter.
Co. Company, County,
Cr. Creditor,
ciu-t. Current, the present month.
D.G. {Dei gratia), By the grace of God-
Do. Ditto, the same.
D.O.M. {Deo Oj)tiTno Maximo), To God the Besi and Greatest
Dr. Debtor.
D. V. {Deo /oolnite)t God will in £^.
* Characters, not properly abbreviations, are used in the same way ;
e.g., ° ' " for "degrees, minutes, seconds," (circular meaaure); 5i 3' ^
for "ounces, drachms, scruples." ^ ^ probably to be traced to the
written form of the x in "oz."
' TlicKC forms (as well as $, the symbol for the American dollar) arc placed before their amounts. * It is fjiwn to Avstna to rule the whole earth. The device of Austria, first adopted by Frederick IIT. * " Per cent" is often u^^nifiod by 7oi a 'orm traceable to " 100." e. g. (Exempli gratia). For example. ect. cr &c. {£t ccttera), And the rest ; and bo forth. Ex, Example. F. or Fahr. Fahrenheit's Thermometet Fe^ {Fecit) f He- made {or did) it fl. Flourished- Fo. or FoL Folio. f.o.b. Free on board. G.P.O, General Post Office . H.M.S. Her Majesty's Ship. lb, or Ibid. {Ibidem), In the same Mlace, Id. {Id^n), The same. i, e. (Id est). That is. I. U.S. Ijesiis Hominum Salvator), Jogua the Saviour of mon, Inl {Infra), Below. inst Instant, the present month, I.O. U. I owe you. i.q. (Idem quod). The same as. K.T.x. (kk) vac XeiTtc), M ccElcra, and the rest, L. or Lib. {LiberS. Book Lat Latitude. Lc. {Loco citato). In the place cited. Lon. *r Long. Lon^^tude. L.S. {Locu^ sigilU), The piace of the seal. Mem. {McTTUiito), Remember, Memorandum, ■ MS. Manuscript. MSS. Manuscript;!. N.B. {N'ota bene). Mack well ; take notice. N.B. North Britain (i.c, Sc/-*-'""d^ N.D. No date. nem, con. {Kemiru^ corUradicente\ No one contradicting. No. {Nuviero), Number. N.S.' NewSiyle. N.T, New Testament ob. {OUit), Died, Ob3, Obsolete I). H.M.S. On Her Majesty's Service. O.S. Old Style. O.T. Old Testament P. Page. Pp. Pa^es. ^. {Per), For ; e.g., ^ lb.. For one pound- Pinx. iPinxit), He painted it. P.M. {Post meridiem), Afternoon. P.O. Post Office. P. 0.0. Post Office Older. P. P.C. {Pour prendre congi). To take leave. P.R. Pri2e-ring. pros. (Proximo [mense]), Next montli, P. S. Postscript Pt Part. p.t or pro. tern. {Pro tempore). For the time. P. T.O. Please turn over. Q., Qu., or Qy. Query ; Question. q.d. {Quasi dicat), Aa if he should say ; as much as to say. Q.E.D. {Quod erat demoTistrandiim), which was to bo denionstrateil, Q.£.F. (Quod erat faciendiim), which was to be done. q.s. or quant Buff. {Quantum sujicit), As much as is sufficient q.v. {Quod vide), 'Which see. R. or R. {Recipe), Take. v' (= r. for radix), the sign of the square root R.I.P. (Rcquiescat in pace I), May be rest in peace I 8C. {Scilicet), Namely ; that is to say. Sc. or Sculp. (Sculpsit), He engraved it. S.D. U.K. Society for the Diffusion of Useful Knowledge. "Seq. or sq., seqq. or sqq. {Sequens, sequcntia). The following. 8. p. {Sine prole). Without offspring. S.P.G. Society for the Propagation oi the Gosnol. Sup. {Supra), Above. S.V. {Sub voce). Under the word {or heading;, T.C.D. Trinity College, Dublin. nit {Ultimo [m^isc^ Last month. U.S. United States. V, ( Versus), Again^ ., V. or vid. ( Fide)^^ce. viz, { Videliccl)^ amoly, V. R, ( Victoria Regina), Victoria the Queen. Xmas. Christmas [TAw X is a Greek letter, corresponding (o Ch] (See Grocvius*8 TJiesanrus Antiquitatnm, 1694, eqq.; Nicolai's Tractatus dc Siglis Veterum ; Mominsen'a Corpus Inscriptionum Laiinarvm, 1863, sqq.; Natalis de Waillys Paleographie, Paris, 1838; Alph, Chassant's Faliopraphie, ,1£54, and Dictionnaire des Abrcmation^, 3d ed., 1866. A manual of the abbreviations in current use is a desideratum. ) ABBREVIATORS, a body of writers in the Papal Chancery, whose business is to sketch, out and prepare in due form the Pope's bulls, briefs, and conaistorial decreea 30 A B D — A B D 'I'hey are first mentioned in a bull of Benedict XIL, early iu the 14th century. Their number ia fixed at seventy- two, of whom twelve, distinguished as de parco mitjori, hold prelatic rank ; twenty-two, de parco minori, are clergymen of lower rank; and the remainder, <j;amtn<j<orM, may be laymen. ABDALLATIF, or Abd-ui^Latif, a celebrated physician and traveller, and one of the most voluminoas writers of the East, was born at Baghdad in 1162. An interesting memoir of Abdallatif, written by himself, has been pre- served \rith additions by Ibn-Abu-Osiiba, a contcmporar)'.' From that work wo learn that the higher education of the youth of Baghdad consisted principally in a minute and careful study of the rules and princijiles of grammar, and in their committing to memorj' the whole of the Koran, a treatise or two on philology and jurisprudence, and the choicest Arabian poetry. After attaining to great pro- ficiency in that kind of learning, Abdallatif applied him- oelf to natural philosophy and medicine. To enjoy the society of the learned, he went fii-st to Mosul (1189), and afterwards to Damascus, the great resort of the eminent men of that age. The chemical fooleries that engrossed the attention of some of these had no attraction for hiin, but he entered with eagerness into speculative discussions. With letters of recommendation from Saladin's vizier, he visited Egj-pt, where the wish ho had long cherished to •converse with Maimonides, " the Eagle of the Doctors," was gratified. He afterwards formed one of the circle of learned men whom Saladin gathered around him at Jeru- salem, and shared in the great sultan's favours. He taught medicine and philosophy at Cairo and at Damascus for a number of years, and afterwards, for a shorter period, at Aleppo. His love of travel led him in his old age to visit different parts of Armenia and Asia Jlinor, and he was sotting out on a pilgrimage to Mecca when he died at Baghdad in 1231. Abdallatif was undoubtedly a man of great knowledge and of an inquisitive and penetrating mind, but is said to have been somewhat vain of his attain- ments. Of the numerous works — most of them on medi- cine — which Osaiba ascribes to him, one only, the Acrount of E;iypt; appears to be known in Europe. The manuscript of this work, which was di.scovcrcd by Pococke the Orien- talist, Ls preserved in the Bodleian Library. It w.is trans- lated into Latin by Professor White of Oxford in 1800, and into French, with very valuable notes, by De Sacy in 1310 It consists of two parts : the first gives a general view of Egypt ; the second treats of the Nile, and contains a vivid description of a famine caused, during the author's residence in Eg)'pt, by the river failing to overflow its banks. The -work gives an authentic detailed account of the state of Egypt during the middle ages. AED-EL-KADER, celebrated for his brave resistance to the advance of the French in Algeria, was born near Mascara, in the early part of the year 1807. His father was a man of great influence among his countrymen from his high rank and learning, and Abd-el-Kader himself at an early age acquired a wide reputation for wisdom and piety, as well as for skill in horsemanship and other manly exercises. In 1831 he was chosen Emir of Mascara, and leader of the combined tribes in their attempt to check the growing power of the French in Africa. His efforts were at first successful, and in 1834 he concluded a treaty with the French general, which was very favourable to his cause. This treaty was broken in the succeeding year; but as the war that followed was mainly in favour of the Arabs, peace was renewed in 1837. War again broke out in 1839, and for more than a year was carried on in a very desultory manner. In 1841, however, Marshal Bugciud assumed the chief command of the French force, which numbered nearly 100,000 men. The -war was now ^earned on with great vigour, and Abd-el-Kader, after a most determined resistance, surrendered himself to the Due d'Aumale, on the 22d December 1847. The promise, that he would be allowed to retire to Alexandria or St Jean d'Acre, upon the faith of which Abd-el-Kader had given himself up, was broken by the French government He was taken to France, and was iniprisoncd fjst in the castle of Pan, and afterwards in th.it of Ainboi.se. In 1852 Louis Napoleon gave him his liberty on condition of hu not returning to Algeria. Since ther he resided successively at Broussa, Constantinople, and Damascus. He is reported to have died at Mecca in October 1873. See Algeria. ABDERA (1.), in Ancient Geography, a maritime town of Thrace, eastward from the mouth of the river Nestua. Mytholog)' a-ssigns the founding of the town to Hercules ; but Herodotus states that it was first colonised by Timesias of ClazomeniB, whom the Thracians in a short time expelled. Rather more than a century later (b.c. 541), the people of Seos recolonised Abdcra, The town soon became one of considerable importance, and in B.C. 408, when it was re- duced by Thrasybulus the Athenian, it is described as in a very flourishing condition. Its prosperity was greatly im- paired by its disastrous war with the Triballi (circa B.C 370), and very little b heard of it thereafter. The Abderitie, or Abderitani, were proverbial for their want of w it and judgment ; yet their city gave birth to several eminent persons, as Protagoras, Democritus, and Anaxarchus the philosophers, Hecataeus the historian, Nicsenetua the poet, and others. ABDERA (2.), a town in Hispania Saeiiea, founded by the Carthaginians, on the south coast, between ilalata and Prom. Charidemi. It is probably represented by the modem Adra. ABDICATION, the act whereby a person in office renounces and gives up the same before the expiry of the time for which it is held. The word is seldom used except in the sense of surrendering the supreme power in a state. Despotic sovereigns are at liberty to divest themselves pi their powers at any time, but it is otherwise with a limited monarchy. The throne of Great Britain cannot be lawfully abdicated unless with the consent of the two Houses of Par- liament. Wnen James IL, after throwing the Great Seal into the Thames, fled to France in 1688, he did not formally resign the crown, and the question was discussed in Parlia- ment whether be had forfeited the throne or had abdicated. The latter designation was agreed on, for in a full assembly of the Lords and Commons, met in convention, it was re- solved, in spite of James's protest, " that King James II. having endeavoured to subvert the constitution of the king- dom, by breaking the original contract between king and people, and, by the advice of Jesuits and other wicked persons, having violated the fundamental laws, and having with- drawn himself out of this kingdom, has abdicated the government, and that the throne is thereby vacant" The Scotch Parliament pronounced a decree of forfeiture and deposition. Among the most memorable abdications of antiquity may be mentioned that of Sulla the dictator, b.c. 79, and that of the Emperor Diocletian, a.d. 305. The follow- ing is a list of the more important abdications of lat<ir times ; — &r> Benedict IX.. Pope, ....... 1046 Stephen II. of Hungary , . . . 1131 Albert (the Bear) of Brandenburg, . . .1169 Ladislaus HI., Duke of Poland, . . . . 1207 John Balliol of Scotland. ..... 1295 John Cantacu^ene, Emperor of the E.ist, . . . 1355 John XXIII , Pope H15 E.nc VII. of Denmark and XIII. of Swivlen, . . . 143S> Amnrath II., Ottoman Emperor, . . U4landl44)^ Charles v.. Emperor,. ...... 155f. Christina of Sweden. ....... 165* John Casimir of Poland, . . ... ]66f> James II. of England. lC3h Frcd'^rick Acpistus of Pobrd 17Ci A B D — A B E 31 rhilip v. of Spain, . . 1724 Victor Amadeus II. of Sardinia, . , . . . 17^0 Aclitnet III., Ottomau Emperor, . . . i7ao <"'liarles of Naples (on accession to throne of Siiaini, 1759 Stanislaus 11. of Toland, 1795 Cljarles Emanuel IV. of Sardiii i I . . . June 4, 1S02 Charles IV. of Spain, Jlar. 19, 1S08 Joseph Bonaparte of Naples, June «> ISOS 'GusUTOs IV. of Sweden, Jlar. 29, 1S09 Ix>ui3 Bonaoarte of Holland, July 2, 1810 iXapoleon of France, . April 4, 13H, and June 22 1S15 Victor Emanuel of Sardinia, Jlar. is'. 1S21 Charles X. of Fi-ance Aug. 2 1330 Pedro of Brazil.' . , . April T 1331 Don Jliguel of Portugal, May 28^ 1834 v.- ...am I. of HoUand, Oct. 7, 1840 Louis Philippe of France, Feb. 24, 1843 lAfUis Charles of Bavaria, Jlar. 21, 1848 Ferdinand of Austria, . Dec 2 1S48 •- Charles Albert of Sardinia, Jlar. 23] 1849 .Leopold 11. of Tuscany, July 21, 1809 .Isabella 11. of Spain, June 25, 1870 . Amadeus I. of Spain, Feb. 11 1873 ABDOMEN, in Anatomy, the lower part of the trunk of ■■ the body, situated between the thorax and the peh-is. See Anatomy. ABDOMINALES, or Abdominal Fishls, a sub-division .of the ilalacopterj-gious Order, whose ventral fins are placid ■ behind the pectorals, under the abdomen. The typical .abdominals are carp, salmon, herring, silures, and pike. ABDUCTIOX, a law term denoting the forcible or fraudulent removal of a person, limited by custom to the £ase where a woman is the victim. In the case of men or .children, it has been usual to substitute the terra Kid- napping (q.v.) The old severe laws against abduction, generally contemplating its object as the possession of an heiress and her fortune, have been repealed by 24 and 25 Vict. c. 100, s. 53, which makes it felony for any one from motives of lucre to take away or detain against her will, ■ -with intent to many or carnally know her, <tc., any woman . of any .age who has any interest in any real or personal .estate, or is an heiress presumptive, or co-heiress, or pre- ;.smnptive next of kin to any one having such an interest ; or for any one to cause such a woman to %e married or . carnally known by any other person ; or for any one with :3uch intent to allure, take away, or detain any such woman nnder the age of twenty-one, out of the possession and against -.the will of her parents or guardians. By 3. 5 4, forcible taking away or detention against her will of any woman of any age ■with like intent is felony. Even without such intent, abduc- ■tion of any unmarried girl under the age of sixteen is a misdemeanour. In Scotland, where there is no statutory adju3tn;ent, abduction is similarly dealt with by practice. ABDUL MEDJID, Sultan of Turkey, the thirty-first sovereign of the house of Othman, was born April 23, 1823, and succeeded his father Mahmoud IL on the 2d • of July 1839. Mahmoud appears to have been unable to effect the reforms he desired in the mode of educating his children, so that his son received no better education than that given, according to use and wont, to Turkish princes in the harem. When Abdul Medjid succeeded to the throne, the affairs of Turkey were in an extremely . critical state. At the very time his father died, the news was on its way to Constantinople that the Turkish aiiuy ;Jiad been signally defeated at Nisib by that of the rebel Egyptian viceroy, Mehemet Ali; and the Turkish fleet was ;at the same time on its way to Egypt, to be surrendered perfidiously by its commander to the same enemy. But through the inter^'ention of the gfeat European powers, Mehemet Ali was obliged to come to terms, and the Otto- man empire was saved. In compliance with his father's Pedro had succeeded to the throne nf Portugal in 1826, but ; <eil U pt dDce \a lavour cf hia daughter. express mstructions, Abdul Medjid set at once about carry- ing out the extensive reforms to which Jlahmoud had so energetically devoted himself. In November 1839 was proclaimed an edict, known as the Hatti-sherif of Gulhanc, consolidating and enforcing these reforms, which was supplemented, at the close of the Crimean war, by a similar statute, issued in February 1S56. By these enact- ments it was provided that all classes of the sultan's sub- jects should have security for their lives and property ; that taxes should be fairly imposed and justice impartially administered ; and that all should have full rehgious liberty and equal civil rights. The scheme was regarded as so revolutionary by the aristocracy and the educated classes (the Ulema) that it met with keen opposition, and was in consequence but partially put in force,' especially in the remoter parts of the empire ; and more than one con- spiracy was formed against the sultan's life on account of it. Of the other measures of reform promoted by Abdul Medjid the more important were-^the reorganisation of the army (1843-4), the institution of a council of public in- struction (1846), the abolition of an odious and unfairly imposed capitation tax, the repression of slave trading, and various provisions for the better administration of the public service and for the advancement of commerce. The pubMc history of his times — the disturbances and insurrections in different parts of his dominions throughout his reign, and the great war successfully carried on against Russia by Turkey, and by England, France, and Sardinia, in the interest of Turkey (1853-56) — can be merely alluded to in this personal notice. When Kossuth and others sought refuge in Turkey, after the failure of the Hungarian rising in 1849, the sultan was called on by Austria and Russia to surrender them, but boldly and determinedly refused. It is to his credit, too, that he would not allow the con- spirators against his own life to be put to death. He bore the character of being a kind and honourable man. Against , this, however, must be set down his excessive extravagance, especially towards the end of his life. He died on the 25th of June 1861, and was succeeded, not by one of his sons, but by his brother, Abdul Aziz, the present sultan, as the oldest survivor of the family of Othman. A BECKET, Thomas, Archbishop of Canterbury and hancellor of England in the 12th century, was born in London on the 21st of December 1118. His father, Gilbert Becket, and his mother Koesa or Matilda, were both, there can be httle doubt, of Norman extraction, if indeed they themselves were not immigrants from Normandy to Englani Gilbert Becket, a merchant, and at one time Sheriff of London, a man of generous impulses and son:o- what lavish hospitality, provided for his only child Thomas all the attainable advantages of influential society and a good education. At ten years of age Thomas was placed under the tuition of the canons regular of Merton on the Wandle in Surrey. From Merton he proceeded to study m the London schools, then in high repute. At Pevensey Castle, the seat of his father's friend Richer de I'Aigle, one of the great barons of England, he subsequently became a proficient in all the feats and graces of chivalry. From Pevensey he betook himself to the study of theology in the Univeisity of ParLs. He never became a scholar, much less a theologian, like Wolsey, or even like some of the learned ecclesiastics of his own day ; but his intellect was vigorous and original, and his manners captivating to his associates and popular with the multitude. His father's failure in business recalled him to London, and for three years he acted as a clerk in a la\\-)er's office. But a man so variously accomplished could not fail to stumble on preferment sooner or later. Accordingly, about 1142, Archdeacon Baldwin, a learned civilian, a friend of tbo elder Becket. introduced hira to Theobald, Aichbiihop of 32 A B b: (' K E T Cauterbury, who ut onco appuinted liim to an oflice iu the Arcliiepiijcopal Court. His talents epocdily raised liiui to llio ardideacoiiry of the sea A Bcckot's tact in assistijig 10 thwart an attempt to interest the Pope in favour of the coronation of Stephen's son Eustace, paved the way to the archdeacon's elevation to the Chancellorship of England under Henry II., a diqnityto which he was raised in 1155. As he had served Theobald the archbishop, so he served Henry the king faithfully and well. It was his nature to be loyal Enthusiastic partisanship is, in fact, the key to much that is otller^vise inexplicable in his subsequent con- duct towards Henry. When at a later period A Beckot was raised to the primacy of England, a dignity not of his own seeking, he must needs quarrel with Henry in the interest of the Pope and " for the honour of God." As Chancellor of England ho appeared iu the war of Toulouse at the head of the chivalry of England, and " who can recount," says his attendant and panegyrist Grim, " the carnage, the desolation he made at the head of a strong body of soldiers 1 lie attacked castles, and razed towns nnd cities to the ground ; he burned down houses and farms, and never showed the slightest touch of pity to any ojo who rose in insurrection against his master. In single coinbal ho vanquished and made prisoner the valiant Knight Engelram de Trie. Xor did A Bccket the chancellor seek to quell Henry's secular foes alone. He was the able mouthpiece of the Crown in its contention with the Bishop of Chichester, who had alleged that the permission of the Pope was necessary to the con- tarring or taking away of ecclesiastical benefices ; and he rigorously exacted sculage, a military tax in lieu of personal service in the field, from the clergy, who accused him of " plunging a sword into the bosom of his mother the church." His pomp and .munificence as chancellor were beyond precedent In 1159 he undfertook, at Henry's request, an embassy to the French Court for the purpose of affiancing the king's eldest son to the daughter of the king of France. His progress through the country was like a triumphal procession. " How wonderful must be the king of England himself whose chancellor travels in such state I" was on every one's hps. In 11S2 he was elected Archbishop of Canterbury, Gilbert Foliot, Bishop of Herford, alone dissenting, and remarking sarcastically, at the termination of the ceremony, that " the king had worked a miracle in having that day turned a laj-mau into an archbishop and a soldier into a saint." Hitherto A Bccket had only been in deacon's orders, and had made no profession of sanctity of life. At the same time, there is nothing to show that his character was stained by the gross licentiousness of the times. Now, however, he devoted himself body and soul to the service of the churcL The fastidious courtier was at once transformed into the squahd penitent, who wore hair-cloth next his skin, fed on Toots, drank nauseous water, and daily washed the feet of thirteen beggars. Henry, who hod expected to see the archbishop completely sunk in .the chancellor, was amazed to receive the follonijig laconic message from A Becket: — " I desire that you will provide yourself with another chancellor, as I find myself hardly sufficient for the duties of one office, much less of two." From that moment there was strife between A Becket and Henry, A Bccket straining every nerve to extend the authority of the Pope, and Henry doing his utmost to subject the church to his own will Throughout the bitter struggle for supremacy which ensued between A Becket and the king, A Becket was backed by the sympathy of the Saxon populace, Henry by the support of the Norman barons and by the greater dignitaries of the church. At the outset A Becket was wotgted. He was constrained to take an oath, "with good faith and without fraud or reserve, to observe the Constitutions of Claren- don." which «ubjecteJ clerlis guilty of crime to the ordinary civil tribunals, put ecclesiastical dignities at ths royal dia posal, prevented all appeals to Rome, and made Henry ths virtual "head of the church." For lus guilty cojiplianco with these anti-pajial constitutions he received the special pardon and absolution of hia holiness, and {.rcKjecded to anathematise them with the energy of a genuine remorse. The king resolved on his ruin. He was summoned before a great council at Northampton, and in defiance of jnstic* was called on to account for the sum of 44,000 marka declared to have been misappropriated by him during hia chancellorship. " For what happened before my consecrar tion," Eaid A Becket, " I ought not to answer, nor will L Know, moreover, that ye are my children in God ; neither law nor reason allows you to judge your father. I refe^niy quarrel to the decision of the Pope. To him I appcJ, and shall now, under the protection of the Catholic Church and the Apostolic See, depart" He effected his escape to France, and took refuge in the Cistercian monastery of Pontigny, whence he repeatedly anathematised his enemies in England, and hesitated not to speak of Henry as a " mali- cious tyrant" Pope Alexander IIL, though at heart a warm supporter of Becket, was guarded in his conduct towards Henry, who had shown a disposition to support tha anti-pope Pascal III., and it was not tiU the Archbishop of York, in defiance of a pa'::'! cidl, had usurped the functions of the exiled primate by officiating at the coronation of Henry's son, that Alexander became really formidable. A Becket was now resolute for martyrdom or victory. Henry began to tremble, and an interview between him and Eockel was arranged to take place at Fereitville in 1170. It was agreed that A Becket should return to his see, and that tha king should discharge his debts and defray the expenses of his journey. A Becket proceeded to the coast, but the king, who had promised to meet him, broke his engagement ia every particular. A Becket, in retaliation, excoramumcated the Archbishop of York and the Bishops of London and Salisbury for officiating at the coronation of the king's son. The terrified prelates took refuge in Normandy with Henry, who, on hearing their tale, accompanied by an account of A Becket's splendid reception at Canterbury, exclaimed io ungovernable fury, " Of the cowards who eat my bread, ia there not one who will free me from this turbulent priest t " Four knights, Fitzurse, Tracy, Morville, and Brito, resolved to avenge their sovereign, who it appears was ignorant of their intention. They arrived in Canterbury, and finding the archbishop, threatened him with death if he would not absolve the excommunicated bishops. ■' In vain," replied A Becket, " you threaten me. If all the swords in England were brandishing over my head, your terrors could not move rae. Foot to foot you will find me fighting the battle of tha Lord. " He was barbarously murdered in tlie great cathedral, at the foot of the altar of St Benedict, on the 29th Decem- ber 1170. Two years thereafter he was canonised by the Pope ; and down to the Reformation innumerable pilgiim- ages were made to the shrine of St Thomas of Cauterbury by devotees from everj' comer of Christendom. So numerous were the miracles wrought at his tomb, that Gervase ol Canterbury tells us two large volumes kept in the cathedral were filled with accounts of them. Every fiftieth year ^ jubdeo was celebrated in his honour, which lasted fifteen days ; plenary indulgences were then granted to all who visited his tomb; and as many as 100,000 pilgrims were registered at a tima in Canterbury. The worship of St Thomas superseded the adoration of God, and even that of the Virgin. In one year there was offered at God's altar nothing; at that of the Virgin .£4, Is. 8d.; while St Thomas received for his share £954, 6s. 3d. — an enormous sum, if the purchasing power of money in those times be considered. Henry VIII., with a just if somewhat ludi- crous appreciation of the i;:$ue which A Ectifit liad raLcJ .
A B E — A L E
33
•with his royal predecessor Henry H, not only piliaged the
rich shrine dedicated to St Thomas, but caused the saint
hiaiself to be cited to appear in court, and to be tried and
condemned as a traitor, at the same time ordering his name
to be struck out of the calendar, and his bones to be burned
and the ashes thrown in the air. A Becket's character and
nimii have been the subject of the keenest ecclesiastical and
historic controversy doivn to the present time, but it is im-
possible to doubt the fundamental sincerity of the one or
the disinterestedness of the other, however inconsistent his
actions may sometimes appear. If the fruit of the Spirit
be " love, joy, peace, long-sulfering, gentleness, goodness,
"faith, meekness, and temperance," A Becket was assuredly
not a saint, for he indulged to the last in the bitterest
invectives against his foes ; but that he fought with
admirable courage and devotion the " battle of the Lord,"
according to the warlike ideas of an age with which he was
in intense sympathj', is bej-ond dispute. He was the
leading Ultramontane of his day, hesitating not to reprove
the Pope himself for lukewarmness in the cause of the
" church's Kberty." He was the last of the great ecclesiastics
of the type of Lanfranc and Anselm, who struggled for
supremacy with the civil power in England on almost equal
terms. In his day the secular stream was running very
strong, and he might as chancellor have noated down the
current pleasantly enough, governing England in Henry's
name. He nevertheless perished in a chivalrous effort tu
■stem the torrent. The tendency of his principles was
to supersede a civil by a spiritual despotism ; " but, in
point of fact," says Hook, in his valuable Life, "he was
a high-principled, high-spmted demagogue, who. taught
the people to struggle for their liberties," a struggle
soon to commence, and of which he was by no means
an impotent if an unconscious precursor. — See Dr Giles's
Vita et EpistolcB S. Hiomce Carduariensis ; Canon ^Morris's
Life of St Thomas Becket ; Canon Robertson's Life of
Becket ; Canon Stanley's Historical Memorials of Canter-
hury ; J. G. Nichoi's PityrtTnagfs of Walsincfkcm and
Canterbury ; Hook's Lives of the Archbishops of Canter-
bury; and Lord Campbell's Lives of the Chancellors of
England.
A'BECKETT, Gilbert Abbott, a successful cultivator
Ci light literature, was born in London in 1811, and educated
at Westminster School. He wrote burlesque dramas with
success from his boyhood, took an active share in the
establishment of ditferent comic periodicals, particularly
Figaro in London and Punch, and vias a constant contributor
. to the columns of the latter from its commencement till the
time of his death. His principal publications, all over-
flowing with kindly humour, and rich in quaint fancies,
are his parodies of li\'ing dramatists (himself included),
Annotations and Explanations (1845) ; The Quizziology of
the British Drama and The Comic Blachslone (1846); A
Comic History of England (1847) ; and A Comic History of
Home (1852). He contributed occasionally, too, to the
Times and other metropolitan papers. A'Beckett was
called to the bar in 1841, and from 1S49 discharged with
great efficiency the duties of a metropolitan police magis-
trate. He died at Boulogne on the 30th of August
1856.
ABEL C'^,^, breath, vanity, transitoriness), the second
eon of Adam, slain by Cain his elder brother (Gen. iv
1-16). The narrative in Genesis, which tells us that "the
Lord had respect unto Abel and to his offering, but unto
Cain and to his offering he had not respect," is supplemented
by the statement of the New Testament, that " by faith
Abel offered unto God a more excellent sacrifice than Cain,"
(Heb. XL 4), and that Cain slew Abel "because his orm
works vere evil and hia brother's righteous " (1 John ill. 1 2).
In patristic theology the striking contrast between the
brothers was mystically explained and typically applied in
various ways. Augustine, for example, regards Abel as
the representative of the regenerate or spiritual man, and
Cain as the representative of the -natural or corrupt man.
Augustine in his treatise De H<sresibus, c. 86, mentions a
sect of Abelitae or AbeUans, who seem to have lived in
North Africa, and chiefly in the neighbourhood of Hippo-
Regius. According to their tradition, Abel, though married,
lived in continence, and they followed his practice in this
respect, so as to avoid the guilt of bringing sinful creatui'es
into the world.
ABEL, Karl Feiedkich (1726-1787), a cele'orated Ger-
man musician. His adagio compositions have been highly
praised, but he attained greater distinction as a performer
than as a composer, his instrument being the Viola digamhu,
which from his time has given place to the violoncello.
He studied under Sebastian Bach, played for ten years
(1748-58) in the band formed at Dresden by the Elector
of Saxony, under Hasse, and then, proceeding to England,
became (I'TSQ) chamber-musician to the queen of George III.
His life was shortened by habits of intemperance.
ABEL, Niels HenkiIj, one of the ablest and acutest
mathematicians of" modern times, was born at Findoe in
Norway in 1802, and died near Arendal in 1829. Con-
sidering the shortness of his life, the extent and thorough-
ness of his mathematical investigations and analyses are
marvellous. His great powers of generalisation were dis-
played in a remarkable degree in his development of the
theory of elliptic functions. Legendre's eulogy of Abel,
" Quelle tete celle du jeune Nori-egien ! " is the more forcible,
that the French mathematician had occupied himself with
those functions for most of his Kfettme. Abel's works,
edited by M. Holmboe, the professor under whom he studied
in 1839.
ABEL, Thomas, a Roman Catholic diiine during the
reicn of Henry VIII., was an Englishman, but when or
where born does not appear. He was educated at Oxford,
where he passed B.A. on 4th Jidy 1513, M.A on 27th
June 1516, and proceeded D.D. On 23d June 1530 le
was presented by Queen Catherine to the reciory of Brad-
well in Essex, on the sea-coast. He had been introduced
to the court through the report of his learning in classical
and hving languages, and accomplishments in music ; and
he was appointed domestic chaplain to Queen Catherine.
_It speaks well both for the chaplain and his royal mistress,
that to the last he dafended the outraged queen against
"bluff King Hal." The Defence, " Invicta Veritas," was
printed at Luneberge in 1532. This pungent Mttle book
was replied to, but never answered, and remains the
defence on Queen Catherine's part. Abel was ensnared, as
greater men were, in the prophetic delusions and ratings of
Elizabeth Barton, called the " Holy Maid of Kent." As
belonging to the Church of Rome, he inevitably opposed
Henry VIII.'s assumption of supremacy in the church.
Ultimately he was tried and condemned for " misprision
of treason," and perished in the usual cruel and ignoble
way. The execution, as described, took place at Smith-
lleld on July 30, 1540. If we may not concede the vene-
rable and holy name of martyr to Abel — and John Fo.\c
is passionate in his refusal of it — yet we must hold that
he at least fell a victim to Ids unsparing defence of hia
qvieen and friend, the "misprision of treason" having
been a foregone conclusion. In stat. 25, Henry VIII., c.
12, he is described as having "caused to be printed
and set forth in this realme diverse books against the
divorce and separation." Neither the Tractatua nor the
"diverse books" are known. — Dodd, Church HL-ln-g,
Brussels, 1737, folio, voL L p. 208; Bourchier, Ui<i. JL'ccl.
i — S
34
A B E L A R D
de ilart'jr. Fratr. minor. (Ingolst. l.").S.".); Pitta, De
Uluilr. Angl. Scrip.; Tinner's BMiotheca IIibemico-Britan-
uica, p. i. ; Zurich, Oriijinal Ltltert relativf to the English
nfformation (Parker Society, pt. iL pp. 209-211 1816);
Foxes Acts and Monuments (Cattley'e, voL v. pp. 438-440);
Burnet, Soames, Biog. Brit.; Wood's Atli^iux (Bli.s«), s. v.;
Stow, Chron. p. 581. (a. a o.)
ABELARD, Peteb, born at Pallet (Palais), not far
from Nantes, lu 1079, was the eldest son of a noblo Breton
house. The name Ahcela>dm (also written Abailardus,
Abaielardm, and in many other ways) is said to lio a cor-
rujition of I/aMardus, substituted by himself for a nick-
uauie Bajolardus given to him when a student. As a
boy, he showed an extraordinary quickness of apprehen-
sion, and, choosing a learned life instead of the active
career natural to a youth of his birth, early became an
adept in the art of dialectic, under which name philosophy,
meaning at that time chiefly the logic of Aristotle trans-
mitted through Latin channels, was the great subject of
liberal stuc'y in the episcopal schools. Roscellin, the
famous canon of Compi^gne, is mentioned by himself as
his teacher ; but v/hether he heard this champion of
extreme Nominalism in early youth, when he wandered
about from school to school for instruction and eiercise,
for himself, remains uncertain. His wanderings finally
brought him to Paris, still under the age of twenty. There,
in the great cathedral school of Notre-Dame, he sat for a
while under the teaching of WUIiam of Champeaiix, the
disciple of St Ansohn and most advanced of Realists, but,
presently stepping forward, he overcame the master in
discussion, and thus began a long duel that issued in
the downfall of the philosophic theory of Realism, tUl then
dominant in the early Middle Age. First, in the teeth of
opposition from the metropolitan teacher, he proceeded to
set up a school of his own at Melun, whence, for more
direct competition, he removed to Corbeil, n,earer Paris.
Tlie success of his teaching was signal, though for a time
he had to quit the field, the strain proving too great for
his physical strength. On his return, after 1 108, he found
William lecturing no longer at Notre-Dame, but in a
monastic retreat outside th'e city, and there battle was
again joined between them. Forcing upon the Realist a
material change of doctrine, he was once more victorious,
and thenceforth he stood supreme. His discomfited rival
stiU had pov.er to keep him from lecturing in Paris, but
soon failed in this last effort also. From llelun, where he
had resumed teaching, Abelard passed to the cipital, and
set up his school on the heights of St Genevieve, looking
over Notre-Dame. When he had increased his distinc-
tion still further by winning reputation in the theological
school of Anselm of Laon, no other conquest remained for
him. He stepped into the chair at Notre-Dame, being also
nominated canon, about the year 1115.
Few teachers ever held such sway as Abelard new
did for a time. Distinguished in figure and manners, he
was seen surrounded by crowds — it is said thousands — of
students, drawn from all countries by the fame of his
teaching, in which acuteness of thought was relieved by
simplicity and grace of exposition. Enriched by the offer-
ings of his pupils, and feasted with universal admiration,
he came, as he says, to think himself the only philosopher
standing in the world. But a change in his fortunes
was at hand. In his devotion to science, he had hitherto
lived a very regular life, Yaried only by the excitement of
conflict: now, at the height of his fame, other passions
began to stir within him. There lived at that time,
within the precincts of Notre-Dame, under the care of her
uncle, the canon Fulbert, a young girl named Heloise, of
noble extraction and born about 1101. Fiir, but still
more remarkable f<5i her knowledge, which extended beyond
Latin, it is said, to Greek and Hebrew, she aw.^ka a feel-
ing of love in the breast of Abelard; and with intent tu
win her, he sought and gained a footing in FiUbert's house
as a regular inmate. Becoming also tutor to the maiden,
be used the unlimited power which he thus obtained over
her for the purpo.so of seduction, though not without
cherishing a real affection which she returned in unparallilc<l
devotion. Their relation interfering with his public work,
and being, moreover, ostentatiously sung by lumself, soon
became known to all the world except the too-confiding
FuIbcrt; and, when at last it could not escape even his
vision, they were separated only to meet in secret. There-
upon Heloise found herself pregnant, and was carried off
by her lover to Brittany, where she gave biilh to a »on.
To appease her furious uncle, Abelard now proposed a
marriage, under the condition that it should be kept
secret, in order not to mar his prospects of advancement in
the church; but of marriage, whether public or secret,
Heloise would hear nothing. She appealed to him not to
sacrifice for her the independence of his life, nor did she
finally yield to the arrangement without the darkest fore-
bodings, only too soon to be realised. The secret of the
man-lage was not kept by Fulbert; and when Heloise, true
to her singular purpose, boldly then denied it, life was
made so unsupportable to her that she sought refuge in the
convent of Argenteuih Immediately Fulbert, believing
that her husband, who aided in the flight, designed to be
rid of her, conceived a dire revenge. He and some others
broke into Abelard's chamber by night, and, taking him
defenceless, perpetrated on him the most brutal mutilation.
Thus cast down from his pinnacle of greatness into an
abyss of shame and misery, there was left to the brilliant
master only the life of a monk. Heloise, not yet twenty,
consummated her work of self-sacrifice at the call of his
jealous love, and took the veil.
It was in the Abbey of St Denis that Abelard, now
aged forty, sought to bury himself with his woes out of
sight. Finding, however, in the cloister neither calm nor
solitude, and having gradually turned again to study, ho
j-ielded after a year to urgent entreaties from without and
within, and went forth to reopen his school at the Priory
of Maisoncelle (1120). His lectures, now framed in a
devotional spirit, were heard again by crowds of students,
and all his old influence seemed to have returned ; but old
enmities were revived also, against which he was no longer
able as before to make head. No sooner had he put ill
writing his theological lectures (apparently the Introductio .
saries fell foul of Iiis rationalistic interpretation of the
Trinitarian dogma. Charging him with the heresy of
Sabellius in a provincial synod held at Soissons in 1121,
they procured hy irregular practices a condemnation of his
teaching, whereby he was made to throw his book into the
flames, and then was r.hut up in the convtnt of St lledaro.
•■Uter the other, it was the bitterest possible exper'ence
that could befall him, nor, in the state of mental dtsola-
tion into which it plunged him, could he find any coafort
from beiii^ soon again set' free. The life in his twn
monastery proving no more congenial than formerly, he
fled from it in secret, and only waited for permission to
live away from St Denis before he chose the one lot that
suited his present mood. In a desert phice near Nogent-
sur-Seine, he built himself a cabin of stubble and reeds,
and turned hermit. But there fortune came back to him
with a new surprise. His retreat becoming known, students
flocked from Paris, and covered the wilderness around him
with their tents and huts. A\"hen he began to teach agaia,
he found consolation, and in gratitude he consecrated the
new oratory they built lor him by the name of the Paraclet«
A B E — A B E
35
Upon tne return of new dangers, or at least of fears,
Abelard left the Paraclete to make trial of another refuge,
accepting an invitation to preside over the Abbey of St
Gildas-de-Rhuys, on the far-off shore of Lower Brittany.
It proved a wretched exchange. The region was inhospit-
able, the domain a prey to lawless exaction, the house itself
savage and disorderly. Yet for nearly ten years he con-
tinued to struggle with fate before he fled from his charge,
yielding in the end only under peril of violent death.^ The
misery of those years was not, however, unrelieved ; for he
had been able, on the breaking-up of Heloise's convent at
Argenteuil, to establish her as head of a new religious
house' at the deserted Pajaclcte, and in the capacity of
spiritual director he often was called to revisit th? spot
lived amid universal esteem for her knowledge and character,
uttering no word under the doom that had fallen upon her
youth ; but now, at last, the occasion came for expressing all
the pent-up emotions of her souL Living on for some time
in Brittany after his flight from St Gddas, Abelard wrote,
among other things,- his famous Historia Calamitcttum,
and thus moved her to pen her first Letter, which remains
an unsurpassed utterance of human passion and womanly
devotion ; the first being followed by the two other Letters, in
which she finally accepted the part of resignation which,
now as a brother to a sister, Abelard commended to her.
He not long after was seen once more npon the field of
his early triumphs, lecturing on Mount St Genevieve in
1136 (when he was heard by John of Salisbury), but it
was only for a brief space : no new triumph, but 'a last
great trial, awaited him in the few years to come of his
chequered life. As far back as the Paraclete days, he
had counted as chief among his foes Bernard of Claii-vaux,
in whom was incarnated the principle of fervent and
unhesitating faith, from which rational inquiry ■ like his
was sheer revolt, and now this uncompromising spirit was
moving, at the instance of others, to crush the growing evil
in the person of the boldest offender. After preliminary
negotiations, in which Bernard was roused by Abelard's
steadfastness to put forth all his strength, a council met
at Sens, before which Abelard, formally arraigned upon a
number of heretical charges, was prepared to plead his
cause. When, however, Bernard, not without foregone
terror in the prospect of meeting the redoubtable dialec-
tician, had opened the case, suddenly Abelard appealed
to Rome. The stroke availed him nothing; for Bernard,
who had power, notwithstanding, to get a condemnation
passed at the councO, did not rest a moment till a second
condemnation was procured at Rome in the following year.
Meanwhile, on his way thither to urge his plea in person,
Abelard had broken down at the Abbey of Cluni, and there,
an utterly iaDen man, with spirit of the humblest, and
only not bereft of his intellectual force, he lingered but a
few months before the approach of death. Removed by
friendly hands,' for the relief of his sufferings, to the
Priory of St 'Marcel, he died on the 21st, of April 1143.
First buried at St Marcel, his remains soon after .were
carried off in secrecy to the Paraclete, and given over to
the loving care of Heloise, who in time came herself to
rest beside them. The bones of the pair were shifted
more than once afterwards, but they were marvellously
preserved even through the vicissitudes of the French
Revolution, and now they lie united in' the well-known
tomb at PJ're-Lachaise.
Great as was the influcnco exerted by Abelard on the
minds of his contemporaries and the course of medifeval
thought, he has been little known in modern times but
for his connection with Heloise. Indeed, it was not till
the present century, when Couisin in 183G issued the
collection entitled Oum-ages vddits d'Ahdard, that his
philosophical performance coold be judged at fif4t hand:
of hi? strictly philosophical works only one, the ethical
treatise Scito te ipsum, having been published earlier,
namely, in 1721. Cousin's collection, besides giving ex-
tracts from the theological work Sic et Non (an assemblage
of opposite opinions on doctrinal points, culled from the
Fathers as a basis for discussion), includes the Lialeciica,
commentaries on logical works of Aristotle, Porphyry, and
Boethius, and a fragment. Lie Generihus et Speciebus. The
last-named wOrk, and also the psychological treatise De
Intellectib'os, published apart by Cousin (in Fraginnni
Philosophiques, vol. ii.), are now considered upon internal
evidence not to be by Abelard himself, but only to have
sprung out of his school. A genuine work, the Glossula
super Porphyrium, from which M. de Rimusat, in hi'j
classical monograph Abelard (1&45^, has given extracts.
remains in manuscript.
The general importanoo of Abelard lies in his having
fixed more decisively than any one before him the
scholastic manner of philosophising, with its object of
giving a formally rational expression to the received
ecclesiastical doctrine. However his own particular inter-
pretations may have been condemned, they were conceived
in essentially the same spirit as the general scheme of
thought afterwards elaborated in the 13th century with
approval from the heads of the church. Through him'
was prepared in the Middle Age the ascendency of the
philosophical authority of Aristotle, which became firfflly
established in the half-century after his death, when first
the completed Organon, and gradually a"ll the other works
of the Greek thinker, came to be known in the schools :
before his time it was rather upon the authority of Plato
that the prevailing Reali.sm sought to lean. As regards
the central question of Universals, without having sufii-
cient knowledge of Aristotle's views, Abelard yet, in
taking middle ground between the extra-t-agant Realism of
his master, William of Champeaux, or of St Anselm, and
the not less extravagant Nominalism (as we have it
reported)- of his other master, RosceUin, touched at more
than one point the Aristotelian position. Along v/ith
Aristotle, also with Nominalists generally, he ascribed f'lll
reality only to the particular concretes ; whUe, in^opposi-
tion to the " insana sententia " of Roscellin, he declared
the Universal to be no mere word (vox), but to consist, or
(perhaps we may say) emerge, in the fact of predication
{sermo). Lying in the middle between Realism and
(extreme) Nominalism, this doctrine has often been spoken
of as ConceptuaJism, but ignorantly so. Abelard, pre-
eminently a logician, did- not concern himself , with the
psychological question which the Conceptuahst aims at
deciding as to the mental subsistence of the Universal.
Outside of his dialectic, it was in ethics that Abelard
showed greatest activity of philosophical thought ; laying
very particular stress upon the subjective intention as
determining, if not the moral character, at least the moral
value, of human action. His thought in this directio:;,
wherein he anticipated something of modern speculatior,
is the more remarkable because his scholastic successsis
accomplished least in the field of morals, hardly venturing to
bring the principles and rcles of conduct under pure plSlo-
sophicat discussion, even after the great ethical inquries of
Aristotle became fully known to them. (o. c. E.)
ABENCERRAGES, a family or faction that is said i^
have held a prominent position in the Moorish kingdora
of Granada in the 15th century.' The name appears to hare
been derived from the Yussuf ben-Serragh, , the head of
the tribe in the time of Mahommed VII., who did, that
sovereign good service in his struggles to retain tho
crown of which he was three times aeprived. ^'•Nothing
ia known of the.family^with certainty; but. the* name ia
B6
A B E — A B E
familiar from the interesting romance of Qines Perez de
Hita, Guerrai cwilet de Oranada, which celebrates the
feuds of the Abencerrages and the rival family of the
ijegtis, and the cruel treatment to which the former were
Bubjected. Florian's Gontalm of Cordova, and Chateau-
briand's Last of the Ahmcerrages, are imitations of Perez
de Hita's work. The hall of the Aboncerragoa iu the
/Vlhambra takes its name from being the reputed scene of
the massacre of the family.
ABENEZRA, or Ibn Ezra, is the name ordinarily given
to AsnAliAM BEN Meik BEN EzRA (called also Abenare or
Svenare), one of the most eminent of the Jewish literati
of the Middle Ages. He was born at Toledo about 1090; left
Spain for Rome about 1140; resided afterwards at Mantua
(1145), at Lucca (1154), at Rhodes (1155 and 1166), and
in England (1159) ; and died probably in 1168. He was
distinguishcQ as a philosopher, astronomer, physician, and
poet, but especially as a grammarian and commentator.
The works by which ho is best known form a series of Com-
mentaries on the books of the Old Testament, which have
nearly all been printed in the great Rabbinic Biblca of
Bomberg (1525-6), Buxtorf (1618-9), and Frankfurter
(1724-7). Abenezra's commentaries are acknowledged to
be of very great value ; he was the first who raised biblical
exegesis to the rank of a science, interpreting the^text
•according to its literal sense, and Ulustrating it from cognate
languages. His style is elegant, but is so concise as to be
sometimes obscure ; and he occasionally indulges in epigram.
la addition to the commentaries, he wrote several treatises
on astronomy or astrology, and a number of grammatical
works.
ABENSBERQ, a smalltown of Bavaria, 18 miles S.W.
of Regensburg, containing 1300 inhabitants. Here Kapo-
leon gained an important victory over the ^^Austrians on
the 20th of April 1809. The town is the Abusina of the
Romans, end ancient ruins exist in its neighbourhood.
ABERAVON, a parliamentary and municipal borough
of Wales, in the county of Glamorgan, beautifully situated
on the Avon, near its mouth, 8 miles east of Swansea.
The town and adjacent villages have increased rapidly
in recent years, from the extension of the mines of coal and
iron in the vicinity, and the establishment of extensive
works for the smelting of tin, copper, and zinc. The
harbour, Port Talbot, has been much improved, and has
good docks ; and there is regular steam communication
with Bristol Ores for the smelting furnaces are imported
from Cornwall, and copper, tin, and coal are exported.
Aberavon unites with Swansea, Kenfigg, Loughor, and
Neath, in returning a member to Parliament. In 1871 the
population of the parish was 3396, of the parliamentary
borough, 11,006.
ABERC07WAY. See Conway.
ABERCROMBIE, John, an eminent physician of Edin-
burgh, was the son of the Rev. George Abercrombie of
Aberdeen, in which city ha was born in 1781. Aiter
cttanding the Grammar School and Marischal College,
Aberdeen, he commenced his medical studies at Edinburgh
in 1800, and obtained his degree of M.D. there in 1803.
Soon afterwards he went to London, and for about a year
gave dUigent attention to the medical practice and lectures
in St George's Hospital In 1804 he returned to Edin-
burgh, became a Fellow of the College of Surgeons, and
commenced as general practitioner in that city ; where, in
dispensary and private practice, he hvid the foundation of
that character for sagacity as an observer of disease, and
judgment in its treatment, that eventually elevated him to
the head of his profession. In 1823, be became a Licen-
tiate of the College of Physicians; in 1824, a Fellow of
that body; and from the death of Dr Gregory in 1822,
he was considered the first physician in Scotland. Aber-
crombie early began the laudable practice of preserving
accurate notes of the cases that fell under his care ; and at
a period when pathological anatomy was far too little
regarded by practitioners in this country, he had the
merit of sedulously pursuing it, and collecting a mass of
most important information regarding the changes pro-
duced by disease on different organs ; bo that, before the
year 1824, he had more extended experience, and more
correct views in this interesting field, than most of his
contemporaries engaged in extensive practic& From 181C
he occasionally enriched the pages of the Edinbui-yk
Medical and Surgical Journal with essays, that disphiy
originality and industry, particularly those " on the diseases
of the spinal cord and brain," and " on diseases of the
intestinal canal, of the pancreas, and spleen." The first
of these formed the basis of his great and very original
work. Pathological and Practical Jiesearchet on Diseases
of the Brain and Spinal Cord, which appeared at Edin-
burgh in 1828. In the same year he published also
another very valuable work, his Researches on the Liteaset
of the Intestinal Canal, Liver, and other Viscera of tlie
Abdomen. Though his professional practice was very
extensive and lucrative, he fonnd time for other specula-
tions and occupations. In 1830 he published his Inquiries
concerning the Intellectual Powers of Man and t/ie Investi-
gation of Truth, a woik which, though less original and
profound than his medical speculations, contains a popular
view of an interesting subject, expressed in simple language.
It was followed in 1833 by a sequel. The Philosophy of
the Moral Feelings, the object of which, as stated in the
preface, was " to divest the subject of all improbable
speculations," and to show " the important relation which
subsists between the science of mind and the doctrines of
revealed religion." Both works have been very extensively
read, reaching the 18th and, 14th editions respectively in
1869. Soon after the publication of Moral Peelings, the
University of Oxford conferred on the author the honorary
degree of Doctor of Medicine, and in 1835 he was elected
Lord Rector of Marischal College, Aberdeen. Dr Aber-
crombie was much beloved by his numerous friends for
the suavity and kindness of his manners, and was uni-
versally esteemed for his benevolence and unaffected piety.
He died on the 14th of November 1844 of a very uncom-
mon disease, the bursting (from softening of the musculai
substance) of the coronary vessels of the heart.
ABERCROMBY, Dattd, M.D. This Scottish physi-
cian was sufficiently noteworthy half a century after his
(probable) decease to have his ^^ova Medicines Praxis
reprinted at Paris in 1740; while during his lifetime his
Tuta ac efficax luis venerew scepe absque mercurio ac semper
absque salivatione mercuriali curando mcthodus (1684, 8vo)
was translated into German and published at Dresden in
1703 (8vo). In 1685 were published De Pulsus Varin-
tione (London; Paris, 1688, 12mo), and Ars explorandi
medicos facultates plantarum ex solo sap. (London). His
Opuscula were collected in 1687. These professional
writings gave him a place and memorial in Bailer's Biblio^
theca Medicinoe Pract. (4 vols. 8vo, 1779, torn, iii, p. 619);
but he claims passing remembrance rather aa a meta^
physician by his remarkable controversial books in theo"
bgy and philosophy. Formerly a Roman Catholic and
Jesuit, he abjured Popery, and published Protestancy
proved Safer than Popery (London, 1686). But by far
the most noticeable of his productions is A Discourse
of Wit (London, 1685). This treatise somehow has fallen
out of sight — much as old coined gold gets hidden away
— so that bibliographers do not seem to have met with
it, and assign it at hap-hazard to Patrick Abercromby,
M.D. ■ Notwithstanding, the most cursory examinatioq
of it proves that in this Discourse of Wit are contained
A B E — A B E
some of the most characteristic and most definitely-put
metaphysical opinions of the Scottish philosophy of com-
mon sense. Of this early metaphysician nothing biographi-
cally has come down save that he was a Scotchman
("Scotus") — bom at Seaton. He was living early in the
iSth century. (HaUer, as fupra; Lawrence Charteris's
M.S., s. V.) So recently as 1833 was printed A Short
Account of Scots Divines by him, edited by James Maidment,
Edinburgh. (a. b. g.)
ABERCROMBT, James, Lord Dunfermline, third son
of the celebrated Sir Ralph Aberpromby; was bom on the
7th Nov. 1776. Educated for the profession of the law,
he was called to the bar at Lincoln's Inn in 1801, but he
was prevented from engaging to any considerable extent in
general practice by accepting appointments, first as commis-
sioner in bankruptcy, and subsequently, ag steward of the
estates of the Duke of Devonshire. He commenced his
political career in 1807, when he was elected member of
Parliament for the borough of Midhurst. His sympathies
declared, and he at once attached himseU to the Whig
party, with which he consistently acted throughout life.
Li 1812 he waa returned for Calne, which he continued to
represent until his elevation to the Scotch bench in 1830.
During this lengthened period he rendered conspicuous and
valuable services to his party and the country. In Scotch
affairs he took, as was natural, a deep interest; and, by
introducing, on two separate occasions, a motion for the
redress of a special glaring abuse, he undoubtedly gave a
strong impulse to the growing desire for a general reform.
In 1824, and again in 1826, he presented a petition from
the inhabitants of Edinburgh, and followed it up by a
motion " for leave to bring in a Bill for the more etfectual
representation of the city of Edinburgh in the Commons
House of Parliament." The motion was twice rejected,
but by such narrow majorities as showed that the monopoly
of the self-elected Council of thirty -three was doomed. In
1827, on the accession of the Whigs to power under Mr
Canning, Abercromby received the appointment of Judge-
Advocate-General and Privy Counsellor. In 1830 he was
raised to the judicial bench as Chief Baron of the Exche-
quer in Scotland. The oflSce was abolished in 1832; and
almost contemporaneously, Edinburgh, newly enfranchised,
was called to return two members to the first reformed
Parliament. As the election marked the commencement
of a new political era, the honoiu' to be conferred possessed
a peculiar value, and the choice of the citizens fell most
appropriately on Francis Jeffrey and James Abercromby,
two of the foremost of those to whom they were indebted
for their hard- won privileges. In 1834 Mr Abercromby
obtained a seat in the cabinet of Lord Grey as Master of
the Mint. On the assembling of the new Parliament in
1835, the election of a speaker gave occasion for the first
trial of strength between the Refo.rm party and the followers
of Sir Robert Peel. After a memorable division, in which
more members voted than had ever before been known,
Abercromby was elected by 316 votes, to 310 recorded for
Manners-Sutton. The choice was amply justified, not only
by the urbanity, impartiality, and firmness with which
Abercromby discharged the public duties of the chair, but
also by the important reforms he introduced in regard to
the conduct of private business. In 1839 he resigned the
office, and received the customary honour of a peerage, with
the title of Lord Dunfermline. The evening of his life was
passed in retirement at Colinton, near Edinburgh, where he
died Ion the 17th April 1858. The courage and sagacity
which marked his entire conduct as a Liberal were never
more conspicuous than when, towards the close of his life,
he availed himself of an opportunity of practically asserting
his cherished doctrine of absolute religious equality. The
important part he took in, originating and supportmg the
United Industrial School in Edinburgh for ragged children,
irrespective of their religious belief, deserves to be grate-
fully acknowledged and remembered, even by those who
took the opposite side in the controversy which arose with
regard to it. *
ABERCROMBY, Patrick, M.D., was the third son of
Alexander Abercromby of Fetterneir in Aberdeenshire, and
brother of Francis Abercromby, who was treated by Jamea
II. Lord Glasford. He was born at Forfar in 1656. A3
throughout Scotland, he could have had there the benefits ot
a good parish school ; but it would seem from after events
that his family was Roman Catholic, and hence, in all pro-
bability, his education was private. This, and not the un-
proved charge of perversion from Protestantism in subser-
viency to James II., explains his Roman Catholicism and
adhesion to the fortunes of that king. But, intending to
become a doctor of medicine, he entered the University of
St Andrews, where he took his degree of M.D. in 1685.
From a statement in one of his preface-epistles to his mag-
num opus, the Martial Achievements of the Scats N'ation,
he must have spent most of his youthful years abroad.
If has been stated that he attended the Univei-sity of
Paris. The Discourse of Wit (1G85), assigned to him,
belongs to Dr David Abercromby, a contemporary. On his
Edinburgh, where, besides his professional duties, he gavR
himself with characteristic zeal to the study of antiquities,
a study to which he owes it that his name still lives, for
he finds no place in either HaUer or Hutchison's Medical
Biographies. He was out-and-out a Scot of the old patriotic
type, and, living as he did during the agitations for the
union of England and Scotland, he took part in the war
of pamphlets inaugurated and sustained by prominent
men on both sides of the Border. He crossed swords
with no less redoubtable a foe than Daniel Defoe in his
Advantages of the Act of Security, compared with those of
the intended Union (Edinburgh, 1707), and A Vindication
of ttu Same against Mr De Foe {ibid.) The logic and
reason were with Defoe, but there was a sentiment in the
advocates of independence which was not suiBciently
allowed for in the clamour of debate ; and, besides, the
disadvantages of union were near, hard, and actual, the
advantages remote, and contingent on many things and
persons. Union wore the look to men like Abercromby
and Lord Belhaven of absorption, if not extinction. Aber-
cromby was appointed physician to James II., but the Re-
volution deprived him of the post. Crawford (in his Peer-
age, 1716) ascribes the title of Lord Glasford to an intended
recognition of ancestral loyalty; its bestowment in 1685
corresponding with the younger brother's graduation as
M.D., may perhaps explain his appointment A minor
literary work of Abercromby's was a translation of M.
Beague's partizan History (so called) of the War carried on
by the Popish Government of Cardinal Beaton, aided by the
French, against the English under the Protector Somerset,
which appeared in 1707. The work with which Aber-
cromby's name is permanently associated is his already
noticed Martial Achievements of tlie Scots Nation, issued in
two noble folios, vol. i. 1711, vol. il 1716. In the title-
page and preface to voL i he disclaims the ambition of
being an historian, but in vol. ii., in title-page and preface
alike, he is no longer a simple biographer, but an historian.
That Dr Abercromby did not usethe word "genuine history"
in his title-page without warrant is clear on every page of
his largo work. Granted that, read in tho light of after
researches, much of the first volume must necessarily be
relegated to the region of the mythical, none the less was
the historian a laborious and accomplished reader and inves-
tigator of all available authorities, as well manuscript aa
38
A B E — A B E
printed ; wkilc the roll of names of iLose tvIio aided liini
includes every :iuiu of note in Scotland at the time, from
Sir Thomas Craig and Sir George Mackenzie to Mr Alex-
ander Niabet and ilr 'fliomaa Kuddimau. The Martial
Achievemtntt has not been reprinted, though practically
the first example of Scottish typography in any way
noticeable, vol. ii. having been printed under the scholarly
supervision of Thomas Ruddiman. The date of his death
is uncertain. It has been variously assigned to 1V15,
1716, 1720, and 172G, and it is uAially added that he left
a widow in great poverty. That he was living in 1710 is
certain, as Crawford speaks of him (in his Peerage, 17 10)
13 "my worthy friend." Probably he died about 1710.
Mfmuirs o/ the Ahercromhi/s, commonly given to Lim, does
not appear to have been published. (Chambers's Eminent
Scolsiiifn, «. v.; Anderson's Scottish Nation, t. v.; Chalmers's
Diog. Diet., ». v.; Chalmers's Life of Rvddiman; Haller's
Bibliotheca Medicina: Pract., 4 vols. 4to, 1779; Hutchin-
son's Diog. Medical, 2 vols. 8vo, 1799; Lce'a Defoe, 3 vob.
8vo.) (a. b. g.)
ABERCROMBT, Sib Ralph, K.B., Lieutenant-General
in the British army, was the eldest son of George Aber-
cromby of Tullibody, Clackjnannanshire, and was born in
October 1734. After passing some time at an excellent
school at Alloa, he went to Rugby, and in 1752-53 he
attended classes in Edinburgh University. In 1754 he was
sent to Lcipsic to study civil law, with a view to his pro-
ceding to the Scotch bar, of which it is worthy of notice
that both his grandfather and his father lived to be the
oldest members. On returning from the Continent he
expressed a strong preference for the military profession,
and r\ cornet's commission was accordingly obtained for
Kim (March 175G) in the 3d Dragoon Guards. lie rose
through the intermediate gradations to the rank of lieu-
tenant-colonel of the regiment (1773), and in 1781 he
became colonel of the 103d infantry. When that regiment
was disbanded in 1783 he retired upon half-pay. That
up to this time ho had scarcely been engaged in active
service, was owing mainly to his disapproval of the policy
of the Government, and especially to his sympathies with
the American colonists in their struggles for independence ;
and his retirement is no doubt to be ascribed to similar
feelings. But on Franc* declaring war against England
in 1793, he hastened to resume his professional dutiesj
and, being esteemed one of the ablest and most intrepid
officers in the whole British forces, he was appointed to
the command of a brigade under the Duke of York, for
service in Holland. He commanded the advanced guard
in the action on the heights of Cateau, and was wounded
at Nimeguen. The duty fell to him of protecting the
British army in its disastrous retreat out of Holland, in
the wrinter of 1794-5. In 1795 he received the honour of
knighthood, the Order of the Bath being conferred on him
in acknowledgment of his services. The same year he
was appointed to succeed Sir Charles Grey, as commander-
in-chief of the British forces in the West Indies. In 1796,
Grenada was suddenly attacked and taken by a detach-
ment of the army under his orders. He afterwards
o'otained possession of the settlements of Demerara and
Essequibo, in Souih America, and of the islands of St
Lucia, St Vincent, and Trinidad. He returned in 1797
to Europe, and, in reward for his important services, was
appointed to the command of the regiment of Scots Greys,
intrusted with the govemnients of the Isle of Wight, Fort
George, and Fort Augustus, and raised to the rank of lieu-
tenant-general He held, in 1797-8, the chief command
of the forces in Ireland. There he laboured to maintain
the discipline of the army, to suppress the rising rebellion,
and to protect the people from military oppression, with a
care worthy alike of a gre.it general and an enlightened
and beneficent statesman. Wlien he was appointed to the
command in Ireland, an invasion of that country by the
French was confidently anticipated by the Engli^h
Government Ho used his utmost efforts to restore the
discipline of an army that was utterly disorganised; and.-
aa a firet step, he anxiously endeavoured to protect the
people, by re-establishing the supremacy of the ci^Hl power,
and not allowing the military to be called out, except when
it was indispensably necessary for the enforcement of the
hiw and the maintenance of order. Finding that he received
ment, and that all his efforts were opposed and thwarted
by those who presided in the councils of Ireland, he resigned
the command. Hia departure from Ireland was dieuly
lamented by the reflecting portion of the people, and was
sjwedily followed by tho.so disastrous results whicft he had
anticipated, and which he so ardently desired and had so
wisely endeavoured to prevent. After holding for a short
period the office of Commander-in-Chief in Scotland, Sir
l\alph, when the enterprise against Holland was resolved
upon in 1799, was again called to command under the
Duke of York. The difficulties of the ground, the incle-
mency of the season, unavoidable delays, the disorderly
movements of the Russians, and the timid duplicity of the
Dutch, defeated the objects of that expedition. But it
was confessed by the Dutch, the French, and the British
alike, that even victory the most decisive could not
have more conspicuously proved the talents of this distin-
guished officer. His country applauded the choice, when,
in 1801, he was sent with an army to dispossess the
French of Egypt. His experience in Holland and the
West Indies particularly fitted him for this new command,
as was proved by his carrj-ing his army in health, in spirits,
and with the requisite supplies, in spite of very great diflS-
culties, to the destined scene of action. The debarkation
of the troops at Aboukir, in the face of an opposing force,
is justly ranked among the most daring and brilliant
exploits of the English army. A battle in the neighbour-
hood of Alexandria (March 21, 1801) was the sequel of
this successful landing, and it was Sir R. Abercromby's
fate to faD in the moment of victory. He was struck by
a spent ball, which could not be extracted, and died seven
days after the battle. The Duke of York paid a just
tribute to the great soldier's memory in the general order
issued on the occasion of his death : — " His steady observ-
ance of discipline, his ever-watchful attention to the
health and wants of his troops, the persevering and un-
conquerable spirit which marked his military career, the
splendour of his actions in the field, and the heroism of
his death, are worthy the imitation of all who desire, like
him, a Hfe of heroism and a death of glory." By a vote
of the House of Commons, a monument was erected in
honour of Sir Ralph Abercromby in St Paul's CathedraL
His widow was created a peeress, and a pension of j£2000
a year was settled on her and her two successors in the
title. It may be mentioned that Abercromby was returned,
after a keen contest, as member of Parliament for his
native county of Clackmannanshire in 1773; but a |»rlia-
mentary life had no attractions, for him, and he did not
seek re-election. A memoir of the later years of his life
(1793-1801), by his son. Lord Dunfermline, was published
in 1861.
ABERDARE, a town of 'Wales, in the county of
Glamorgan, on the right bank of the river Cynon, four
miles S.W. of MerthjT-Tydvil llie district around is
rich in valuable mineral products, and coal and iron
mining are very extensively carried on in the neighbour-
hood. Important tin-worki?, too, have been recently
opened. Part of the coal is used at the iron-works, and
large quantities are sent to Cardiif for exportation. Aber-
ABERDEE"N
39
dare JS connected with the coast by canal and railway.
Owing to the great development of the coal and iron
trade, it has rauidiy increased from a mere village to a
large and flourishing town. Handsome churches, banks,
and hotels have been erected, a good supply of water has
been introduced, and a public park has been opened.
Two markets are held weekly. The whole parish falls
within the parliamentary borough of Merthyr-Tj;dvil.
The rapid growth of its population is seen by the fol-
lowing tigures : in 1841 the number of inhabitants was
6471 ; in 1851. 14,999 ; in 1861, 32,299; and in 1871,
37,774.
ABERDEEN, a royal burgh and city, the chief part .of a
parliamentary burgh, the capital bi the county of Aberdeen,
the chief seaport in the north of Scotland, and the fourth
Scottish town in population, industry, and wealth. It lies
in lat. 57° 9' N. and" long. 2° 6' W., on the German Ocean,
near the mouth of the river Dee, and is 542 miles north
of London, and 111 miles north of Edinburgh, by the
shortest railway routes.
ABERDEEN
ta^^^^^^SiSF-^ : ' "^ ^\S ^ A \ ■ ) "
Aberdeen, probably the Devana on the Diva of Ptolemy,
was an important place in the 1 2th century. "William the
Lion had a residence in the city, to which he gave a char-
ter in 1179, confirming the corporate rights granted by
David I. - The city received many subsequent royal
charters. It was burned by Edward III. in 1336,' but
it was soon rebuilt and extended, and called New Aber-
deen. The houses were of timber and thatched, and
many such existed till 1741. 'The burgh records are the
oldest of any Scottish burgh. They begin in 1398, and are
complete to the present time, with only a short break.
Extracts from them, extending from 1398 to i570, have
the city was subject to attacks by the barons of the sur-
rounding districts, and its avenues and sLx ports had to
be guarded. The ports had all been removed by 1770.
Several monasteries c^cistcd in Aberdeen before the Re-
furmation. "Most of the Scottish sovereigns jifiitcJ the
blockhouse was built at the harbour mouth as a protection
against the English. During the religious struggle in the
1 7th century between the Royalists and Covenanters the
city was plundered by both parties. In 1715 Earl
Marischal proclaimed the Pretender at Aberdeeru In 1745
the Duke of Cumberland resided a shoit time in the city.
In the middle of the 18th century boys were kidnapped
in Aberdeen, and sent as slaves to America. In 1817 the
city became insolvent, with a debt of £225,710, contracted
by public improvements, but the debt was soon paid off.
The motto on the city arms is Bon- Accord. It formed the
watchword of the Aberdonians while aiding King Robert
the Bruce in his battles with the English.
Of eminent men connected with Aberdeen, New and
Old, may be mentioned — John Barbour, Hector Boece or
Boethius, Bishop Elphinstone, the Earls Marischal ; George
Jamesone, the famous portrait painter ; Edward Raban, the
first printer fn Aberdeen, 1622 ; Rev. Andrew Cant,
the Covenantor ; David Anderson (Davie do a' thing), a
mechanic ; James Gregory, inventor of the reflecting
telescope ; Dr Thomas Reid, the metaphysician ; Dr George
Campbell, Principal of Marischal Qollege, author of several
important works, and 'best known by his Philosophy o/
Rhetoric; Dr James Beattie ; Lord ' Byron ; Sir James
Mackintosh; Robert HaU • Dr P- Hamilton,' who wrote on
the National Debt.
Till 1800 the city siood on a few eminences, and had
steep, narrow, and crooked streets, but,, since the Improve-
ment Act of that year, the whole aspect of the place has
been altered by the formation of two new spacious and
nearly level streets (Union Street and King Street, meet-
ing in Castle Street), and by the subsequent laj-ing out of
many others, besides squares, 'terraces, «fec., on nearly flat
ground.- The city is above eight miles in ciixuit, and is
built on sand, gravel, and boulder clay. The highest parts
are from 90 to 170 feet above the sea. The chief thorough-
fare is Union Street, nearly a mile long and 70 feet broad.
It runs "W.S.'W. from Castle Street, and crosses the Den-
b'urn, now the railway valley, by a noble granite arch 132
feet in span and 50 feet high, whichj^ost. .with a -hidden
arch'on each side, j£13,000.
Aberdeen is now a capaciou.ij'^elegant, and well-built 'Public
town, and fron^the material employed, consisting chiefly of .Buildtncsi
light grey native granite, is called . the " granite city.";
It contains many fine public buildings. The principal of
these is Marischal College or University Buddings, which
stands on the site of a pre-Reformation Franciscan Convent,
and was rebuilt, 1836-1841, at a cost of about £30,000.
It forms three sides of a court, which is 117 by 1 05 feet,
and has a back wing, and a tower 100^ feet high. Thf
accommodation consists of twenty-five large class-rooms ana
.laboratories, a hall, library, museums, &c.
The University of Aberdeen was formedby the' union
and incorporation, in 1860, by Act of Parliament, of the
University and King's College of Aberdeen, founded in Old
Aberdeen, in 1494, by William Elphinstone, Bishop of
Aberdeen, under the authoritj' of a Papal bull obtained by
James I'V., and of the Marischal College and University of
Aberdeen, founded in New Aberdeen, ia 1593, by George
Keith, Earl JIarischal, by a charter ratified by Act of Par-
liament. _ The officials consist of a chancellor, with rector
and principal; there. are 21 professors and 8 assistanta
Arts and divinity are taught in King's College, and medicine,
natural history, and law in Marischal College. The arts
session lasts from the end of October to the beginning
of April. The arts curriculum of four years, with gradua-
tion, costs £36, lis. There are 214 arts bursaries, 29
divinity, and 1 medical, of the aggregate annual value of
£3646, £650, and £26, respectively. About CO art»
40
ABERDEEN
bursaries, mostly from £10 to £35 in vaiue, are given
yearly by competition, or by presentation and examination.
Two-tliinla of the arts studcDts are bursars. Seventeen
annual scholarships and prizes of the yearly value of X758
are given at the end of the arts curriculum. The average
yearly number of arts students, in the thirteen years
since the union of the arts classes of the two colleges in
18G0, has been 3i2, while in the separate colleges together
for the nine years before the union, it was 431. In winter
session 1872-73 there were 623 matriculated students in
all the faculties. In 1872, 32 graduated in arta, 68 in
medicine, 5 in divinity, and 1 in law. The library has
above 80,000 volumes. The General Council in 1873 had
2075 registered members, who, with those of Glasgow Uni-
versity, return one member to Parliament.
The Free Church Divinity College was built in 1850,
at the cost of £2025, in the Tudor-Gothic style. It has a
Inrge hall, a library of 12,000 volumes, and 15 bursaries of
the yearly value of from £10 to £25.
At the east end of Union Street, and partly in Castie
Street, on the north side, are the now County and Muni-
cipal buildings, an imposing Vranco-Scottish Gothic pile,
225 feet long, 109 feet broad, and 64 feet high, of four
Btorics, built 1867-1873 at the cost of £80,000, including
£25,000 for the site. Its chief feature is a tower 200
feet high. It contains a great ball, 74 feet long, 35 feet
bro-id, and 50 feet high, with an open timber ceiling : a
Justiciary Court-House, 50 feet long, 37 feet broad, and
31 foot high; a Town Hall, 41 feet long, 25 feet broad,
and 15 feet high, and a main entrance corridor GO feet
long, 16 feet broad, and 24 feet high. A little to the west
is the Town and County Bank, a highly ornamented building
inside and outside, in the Italian style, costing about
£24,000.
A very complete closed public market of two floors was
built in 1842, at a cost of £28,000, by a company incor-
porated by Act of Parliament. The upper floor or great
hall is 315 feet long, lOo feet broad, and 45 feet high,
with galleries all round. The lower floor is not so high.
The floors contain numerous small shops for the sale of
meat, fowls, fish, &c., besides stalls and seats for the sale
of vegetables, butter, eggs, <fec. The galleries contain small
shops for the sale of drapery, hardware, fancy goods, and
books. On the upper floor is a fountain of polished Peter-
head granite, costing £200, with a basin 7J feet diameter,
cut out of one block of stone. Connected with this under-
taking was the laying out of Market Street from Union
Street to the quay. At the foot of this street is being built
in the Italian style the new post and telegraph office, at a
cost of £16,000, including £4000, the cost of the site.
It is to form a block of about 100 feet square and 40 feet
high.
Chiircliea Aberdeen has about 60 places of worship, with nearly
«°<i 48,000 sittings. There are 10 Established churches; 20
" Free, 6 Episcopalian, 6 United Presbyterian, 5 Congre-
gational, 2 Baptist, 2 Methodist, 2 Evangelical Union, 1
Unitarian, 1 of Roman Catholic, 1 of Friends, and 1 of Origi-
nal Seceders. There are also several mission chapels. In
1843 aU the Established ministers seceded, with 10,000 lay
members. The Established and Free Church denomina-
tions have each about 11,000 members in communion.
The Established West and East churches, in the centre of
the city, within St Nicholas churchyard, form a continuous
building 220 feet long, including an intervening aisle, over
which is a tower and spire 140 feet higL The West was
built in 1775 in the Italian style, and the East in 1834 in
the Gothic, each costing about £5000. They occupy the
site of the original cruciform church of St Nicholas, erected
in the I3th, 14th, and 15th centuries. One of the nice
(bells la the tower bears the date of 1352. and is 4 feet
diameter at the moiith, 3^ feet high, and very thick. Tie
Union Streiit front of the churchyard is occupied by a
very elegant granite facade, built in 1830, at the cost of
£1460. It is 147^feet long, with a central arched gateway
and entablature 32J feet high, with two attached Ionic
columns on each side. Each of the two wings ha;i sLit
Ionic columns (of single granite blocks, 15 feet 2 inches
long), with boaement and entablature, the Whole being 23J
feet high. The following are the style, cost, and date of
erection of the other principal Aberdeen churches — St An-
drew's, Episcopal, Gothic, £6000, 1817; North Church,
Established, Greek, £10,000, 1831; three churches in f.
cruciform group. Free, simple Lancet Gothic, with a fin.
brick spire 174 feet high, £5008, 1844; Roman Catholic
Gothic, £12,000, 1859; Free West, Gothic. £12.858, 1869.
with a spire 175 ftet high.
In 1873 there were in Aberdeen about 110 school*, ^i}
from 10,000 to 11,000 pupils in attendance. About 2501:
students attend the University, Mechanics' Institution, and
private schools for special branches.
Five miles south-west of Aberdeen, on the south side oi
the Dee, in Kincardineshire, is St Mary's Roman Catholic
College of Blairs, with a president and three professors.
The Aberdeen Grammar School, dating from about 1203,
is a preparatory school for the university. It haa a tectoi
and four regular masters, who teach classics, English,
arithmetic, and mathematics, for the annual fee of £4, lOs.
for each pupil. Writing, drawing, itc, are also taught.
Nearly 200 pupils attend, who enter about the ag? of
twelve. Like the Edinburgh High School, it has nj
elementary department. There are 30 bursaries. A new
granite building for the school was erected, 1861-1803,
in the Scotch baronial style, at the cost of £16,000, in-
cluding site. It is 215 feet lone and 60 feet high, and
has three towers.
The Mechanics' Institution, founded 1824, and re-
organised 1834, has a hall, class-rooms, and a library of
14,000 volumes, in a building erected in 1846, at a coist of
£3500. During the year 1872-73, there were at the School
of Science and Art 385 pupils ; and at other evening classes,
538.
Aberdeen has two native banks, besides branch banks, Ljuke. JL^
and a National Security Savings Bank ; three insurance
companies, four shipping companies, three railway com-
panies, and a good many miscellaneous companies. There
440,000 pledges in the year for £96,000, and with a
capital of £27,000. There are seven incorporated trades,
originating between 1398 and 1527, and having charitable
funds for decayed members, widows, and orphans. They
have a hall, built in 1847 for £8300, in the Tudor Gothic
style. The hall, 60 feet long, 29 wide, and 42 high, con-
tains curious old chairs, and curious inscriptions on the
shields of the crafts.
Among the charitable institutions is Gordon's Hospital, Cluritic*.
founded in 1729 by a miser, Robert Gordon, a Dantzic
merchant, of the Straloch family, and farther endowed
by Alexander Simpson of CoUyhill in 1816. It is
managed by the Town Council and four of the Established
ministers of Aberdeen, incorporated by royal charters of
1772 and 1792. The central part of the house was built
in 1739, and the wings in 1830-1834, the whole costing
£17,300, and being within a garden of above four acres.
It now (1873) maintains and educates (in English, writing,
arithmetic, physics, mathematics, drawing, music, French,
<Uc.) 180 boys of the age 9 to 15, the sons and grandiona
of decayed burgesses of guild and trade of the city; and
next those of decayed inhabitants (not paupers). Expendi-
ture for year to 31st October 1872, £4353 for 164 Ix.ys.
It has a head-master, three regular, and several visitiiig
ABERDEEN
41
masters. The Boys' and Girls' Hospital, lately built for
£10,000, maintains and educates 50 boys and 50 girls.
The Female Orphan Asylum, founded by Mrs Elmslie,
in 1840, and managed by trustees, maintains and educates,
chiefly as domestic servants, 46 girls between the ages of
4 and 16, at the yearly cost for each of about £23, 13s.
Thco admitted must be legitimate orphan daughters of
respectable parents, who have lived three years imme-
diately before death in Aberdeen or in the adjoining
parishes of Old Machar and Nigg. The Hospital for
Orphan and Female Destitute Children, endowed by John
Carnegie and the trustees of the Murtle Fund, maintains
and educates 50 girls, chiefly for domestic service. The
Asylum for the Blind, e3tabli.shed in 1843, on a foundation
by Miss Cruickshank, maintains and educates about 10
blind children, and gives industrial employment to blind
adults. There is a boys' and girls' school for 150 boys
and 150 girls on Dr BeU's foundation. The Industrial
Schools, began by Sheriff Watson in 1841, and the Re-
formatory S -hools, begun in 1857, having some 600 pupils
on the roU, have greatly diminished juvenile crime in the
district. The Murtle or John Gordon's Charitable Fund,
founded in 1815, has an annual revenue from land of about
£2400, applicable to all kinds of charity, in sums from
£5 to £300. The Midbeltie Fund, founded by a bequest
of £20,000, in 1348, by James Allan of Midbeltie, gives
yearly pensions ranging from £5 to £15 to respectable
decayed widows in the parishes of St Kicholas and Old
Machar.
The two pansnes in which Aberdeen is situated, viz.,
St Nicholas and Old Machar, have each a large poor-house.
The poor of both parishes cost about £20,000 a year.
The Royal Infirmary, instituted in 1740, was rebuilt
1833-1840, in the Grecian style, at the cost of £17,000.
It is a well-situated, large, commodious, and imposing
building. It has thi'ee stories, the front being 166 feet
long and 50 feet high, with a dome. A detached fever-
house was built in 1872 for about £2500. The managers
were incorporated by royal charter in 1773, and much
increased in number in 1852. The institution is sup-
ported by land rents, feu-duties, legacies, donations, sub-
scriptions, church collections, &c. Each bed has on an
average 1200 cubic feet of space. There are on the average
1 30 resident patients, costing each on the average a shilling
daily, and the number of patients treated may be stated at
1 700 annually, besides outdoor patients receiving advice and
medicine. The recent annual expenditure has been about
£4300. There is a staff of a dozen medical ofiicers.
The Royal Lunatic Asylum, opened in 1800, consists of
two separate houses, valued in 1870 at £40,000, in an
enclosure of 40 acres. It is under the same management
as the Infirmary. The recent daily average of patients has
been about 420, at an annual cost of £13,000. The annual
rate for each pauper is £25, lOs. The General Dispensary,
Vaccine, and Lying-in Institution, founded in 1823, has
had as many as 6781 cases in one year. The Hospital for
Incurables has a daily average of 26 patients, and the Oph-
thalmio and Auric Institution has had 671 cases in a year.
The Music Hall, built Li 1821 and 1859 at the cost
Muiiic of £16,500, has a front 90 feet long, with a portico of 6
H^li. Ionic pillars 30 feet high; large, highly-decorated lobbies
and zooms; and a hall 150 feet long, 63 broad, and 50
high, with a flat ceiling, and galleries. The hall holds 2000
pei-sons seated, and has a fine organ and an orchestra for
3C0. Hero H.R.H. Prince Albert opened the British
Association, as president, 14th September 1859. A new
Theatre and Opera House was built in 1872, in the mbcod
l'.i.'atro. Gothic style, for £8400, with the stage 52i feet by 29, and
the auditorium for 1700 to 1800 persons. The front wall
IS of bluish granite and red and yellow freestone, with
some polished Peterhead granite pillars, the rest being
built of concrete.
In Castle Street, the City PUce and Old Market Stance,
is the Market Cro.sa, a beautiful, open-arched, hexagonal
structure of freestone, 21 feet diameter, and 18 feet high.
It has Ionic columns and pilasters, and an entablature of
twelve panels. On ten of the panels are medallions,
cut in stone, in high relief, of the Scottish sovereigns fri,m
James I. to James VIL From the centre rises a com-
posite column 12^ feet high, with a Corinthian capital, on
which is the royal unicorn rampant. This cross was planned
and erected about 1C82 by John Montgomery, a native
architect, for £100 sterling. On the north side of the
same street, adjoining the municipal buildings, is thu
North of Scotland Bank, a Grecian building in granite,
with a portico of Corinthian columns, having most elabo-
rately carved capitals. On an eminence east of Castle
Street are the military barracks for 600 men, built in 1796
for £16,000.
The principal statues in the city are those of the last
Duke of Gordon — died 1836 — in grey granite, 10 feet high;
Queen Victoria, in white Sicilian marble, 8 J feet high;
Prince Albert, bronze, natural-size, sitting posture; and a
curious rough stone figure, of unknown date, supposed to
be Sir W illia m Wallace.
The Dee to the south of the city is crossed by three
bridges, the old bridge of Dee, an iron suspension bridge,
and the Caledonian Railway bridge. The first, till 1832
seven semicircular ribbed arches, is about 30 feet high,
and was built early in the 1 6th century by Bishops Elphic-
stone and Dunbar. It was nearly all rebuilt 1718-1723,
and from being 14J feet wide, it was in 1842 xnade 26
feet wide. From Castle Street, King Street leads in the
direction of the new bridge of Don (a little east of the old
" Brig o' Balgownie "), of five granite arches, each 75 feet
span, built for nearly £13,000 in 1827-1832.
A defective harbour, and a shallow sand and gravel bar at
its entrance, long retarded the trade of Aberdeen, but, under
various Acts since 1773, they have been greatly deepened.
The north pier, b'lilt partly by Smeaton, 1775-1781, and
partly by Telford, 1810-1815, extends 2000 feet into the
German Ocean. It is 30 feet broad, and, with the parapet,
rises 15 feet above high water. It consists of large granite
blocks. It has increased the depth of water on the bar
from a few feet to 22 or 24 feet at spring tides, and to 17
or 18 feet at neap. The wet dock, of 29 acres, and with
6000 feet of quay, was completed in 1848, and called
Victoria Dock, in honour of Her Majesty's visit to the
city in that year. These and other improvements of the
harbour and its entrance cost £325,000 down to 1848.
By the Harbour Act of 1868, the Dee near the harbour
has been diverted to the south, ac the cost of £80,000,
and 90 acres of new ground (in addition to 25 acres
the city or north side of the river; £80,000 has beeu
laid out in forming in the sea, at the south side of the
river, a new breakwater of concrete, 1050 feet long, against
south and south-east storms. The navigation channel is
being widened and deepened, and the old pier or break-
water on the north side of the river mouth is to ba
lengthened at least 500 feet seaward. A body of 31 com-
missioners manage the harbour affairs.
Aberdeen Bay affords safe anchorage with off-shore wind.s,
but not with those from the N.E., E., and S.E. On the
Girdlei ess, the south point of the bay, a lighthouse was
built iL 1833, in lat 57' 8' N., and long. 2° 3' W., with
tv/o &xed lights, one vertically below the other, and re-
spectively 115 and 185 feet above mean tide. There are
also fixed leading lights to direct shrps entering the harbour
L — 6
Market
Crosa
Bildgei".
Harbonr,
42
ABERDEEN
Water.
turcs, &c.
at night. In fogfl, a steam whi»tlo near tUo lighthouse is
sounded ten seconds every minute. Near the harbour
mouth are three batteries mounting nineteen guns.
The water supplied to the city contains only 3J grains
solid matter in a gallon, with a hardness of about 2 degrees.
It is brought by gravitation, in a close brick culvert,
from the Dec, 21 miles W.S.W. of the city, to a reservoir,
which supplies niie-tentha of the city. The other tenth,
or higher part of the city^is supplied by a separate leaer-
voir, to which part of the water from the culvert is forced
up by a hydi-aulio engine. Nearly 40 gallons water per
head of the population are consumed daily for all purposes.
The new water works cost XI 00,000, and were opened by
Her Majesty, IGth October 18GG.
The gas is made of cannel coal, and is sent tlirough 71
miles of main pipes, which extend 5 miles from the works.
The manufactures, arts, and trade of Aberdeen and
vicinity are 1 irge and flourishing. Woollens were made as
early as 170; , and knitting of stockings was a great industry
in the 18tb century. There are two large firms in the
woollen trade, with 1550 hands, at £1000 weekly 'wages,
and making above 1560 tons wool in the year into yams,
carpets, h.-'nd-knit hosiery, cloths, and tweeds. The linen
trade, much carried on since 1749, is now confined to one
firm, with 2G00 hand.s, at £1200 wages weekly, who spin,
weave, and bleach 50 tons flax and CO tons tow weekly,
and produce yarns, floorcloths, sheetings, dowlas, ducks,
towels, sail-canvas, &c. The cotton manufacture, introduced
in 1779, employs only one firm, with 550 hand.<i, at £220
weekly wages, who spin 5000 bales of cotton a-year into
mule yarn. The wincey trade, begun in 1839, employs
400 hands, at £200 weekly wjges, who make 2,100,000
yards cloth, 27 to oG inches broad, in the year. Paper,
first made here in 1G96, is now manufactured by three
firms in the vicinity. The largest has 2000 'hands, at
£1250 weekly wages, and mokes weekly 75 to 80 tons of
writing paper, and 6J millions of envelopes, besides much
cardboard and stamped paper; another firm makes weekly
77 tons coarse and card paper; and a third, 20 tons print-
ing and other paper. The comb works of Messrs Stewart
ife Co., begun in 1827, are the largest in the world, em-
ploying 900 hands, at £500 weekly wages, who yearly
convert 1100 tons horns, hoofs, india-rubber, and tortoise-
shells into 1 1 millions of combs, besides spoons, cups,
scoops, paper-knives, <fec. Seven iron foundries and
many engineering works employ lOOC men, at £925
weekly wages, and convert 6000 tons of iron a-year into
marine and land steam engines and boilers, corn mills,
wood-preparing machinery, machinery to grind and pre-
pare artificial manures, besides sugar mills and frames and
coffee machinery for the colonies.
The Sandilands Chemical Works, begun in 1848, cover
five acres, and employ over 100 men and boys, at £90 to
£100 weekly wages. Here are prepared naphtha, benzole,
creosote oil, pitch, asphalt, sulphate of ammonia, sulphuric
acid, and artificial manures. Paraffin wax and ozokerite
are refined. An Artesian weU within the works, 421 feet
deep, gives a constant supply of good water, always at
51 Fahr. Of several provision-curing works, the largest
employs 300 hands, chiefly females, in preserving meats,
soups, sauces, jams, jeU-es, pickles, &c., and has in con-
nection with it, near the city, above 230 acres of fruit, vege-
table, and farm ground, and a large piggery. The products
of the breweries and distilleries are mostly comsumed at
home. A large agricultural implement work employs 70
or 80 men and boys. Nearly 200 acres of ground, within
three miles of the city, are laid out in rearing shrub and
forest-tree seedlings. In 1872 about 145 acres of straw-
berries were reared within three miles of Aberdeen, and
(JU tuua of this fruit are said to have b«en exported.
< Fishing
Sliipbuild-
»ng.
Very uurjiblo grey grjiiito has been quarried near Abcr- CraniK.
decn for 300 years, ajd blocked and dre&sed pa^Hng, kerb,
and building granit* stones Lave long been exported from
the di.ftrict In 1764, Aberdeen granite pavement was first
used in London. .About the year 1 795, large granite blocks
were sent for the Portsmouth docks. The chief stouts of
the New Thames Embankment, Loudon, are from Kemn.iy
granite quarrie*, 10 miles northwest of the city. Aber-
deen is almost entirely built of granite, and Urge quantities
of the stone are exported to build bridges, wharfs, docks,
lighthouses, &c, elsewhere. Aberdeen is famed for \l»
polishing-workfl of grapite, especially grey and red. They
employ about 1500 hands in polishing vases, tables,
chimney-pieces, fountains, monuments, columns, ic., for
British and foreign demand. Mr Alexander Mjicdonald,
in 1818, was the first to begin the granite polishing trade,
and the works of the same firm, the only ones of the kind
till about 1850, are still the largest in the kingdom.
In 1820, 15 vessels from Aberdeen were engaged in tho
northern whale and seal fishing; in 18C0, one vessel, but
none since. The white fishing at Aberdeen employs some
40 boats, each with a crew of 5 men. Of the 900 tons
wet fish estimated to be brought to market yearly, above a
third are sent fresh by rail . to England. The salmoc
caught in the Dee, Don, and sea are nearly all sent to
London fresh in ice. The herring fishing has been pro-
secuted since 1836, and from 200 to 350 boats are
engaged in it.
Aberdeen has been famed for shipbuilding, especially
for its fast clippers. Since 1855 nearly a score of vessels
have been built of above 1000 tons each. The largest
vessel (a sailing one) ever built here was one in 1855, of 2400
tons.. In 1872 there were built 11 iron vessels of 9450
tons, and 6 wooden of 2980 tons, consuming 5900 tons
iron, and costing £252,700, including £70,700 for engines
and other machinery. '1400 hands were employed in
shipbuilding in that year, at the weekly wages of about
£1230.
In 1872, there belonged to the port of Aberdeen 236 Shipping
vessels, of 101,188 tons, twenty-four of the vessels, of 7483
tons, being steamers. They trade with most British and
Irish ports, the Baltic and Mediterranean ports, and many
more distant regions. In 1872, 434,108 tons shipping
arrived, ^t the port, and the custom duties were £112,414.
The export trade, exclusive of coasting, is insignificant.
The shore or harbour dues were £126 in 1765, and £1300
in 1800. In the year ending 30th September 1872, they
were £25,520; while the ordinary harbour rc\enue was
£37,765, expenditure £28,598, and debt £324,614. The
introduction of steamers in 1821 greatly promoted in-
dustry and traffic, and especially the cattle trade of
Aberdeenshire with London. These benefits have been
much increased by the extension of raOw ys. Commodious
steamers ply regularly between Abe.Ucen and Londoli,
Hull,' Newcastle, Leith, Wick^ Kii"kwall, and Lerwick.
The joint railway station for the Caledonian, Great
North of Scotland, and Deeside lines, was opened 1867,
and is a verj' handsome erection, costing about £26,000.
It is 500 feet long, and 102 feet broad, with the side walls
32 feet high. The arched roof of curved lattice-iron ribs,
covered with slate, zinc, and glass, is all in one span, rising
72 feet high, and is very light and airy.
The Medico-Chinirgical Society of Aberdeen was founded
in 1789. The haU was built in 1820 at a cost of £4000,
and is adorned with an Ionic portico of four granite columns,
27 feet high. It has 42 members, and a library of 6000
volumes. The legal practitioners of Aberdeen have been
in 1774, 1779, and 1862. They form a society, called
th.j Society of Advocates, of 127 members in 1873, with a
Itailway.
StatioD.
Societiet.'
ABERDEEN
4;^
fre^.
Public
Parks.
pality.
iall built in 187^ for £5075, a library of nearly 6000
volumes, and a fund to support decayed and indigent
members, and their nearest relatives. The revenue in
1872 wa3i2S80.
Aberdeen has on^ daily and three weekly newspapers.
The Aberdeen Journal, established in 1748, is the oldest
newspaper north of the Forth.
The places of out-door recreation and amusement are
chiefly the following: — The Links, a grassy, benty, and
Bandy tract, 2 miles long and J to J mile broad, along
the shore between the mouths of the Dee and the Don.
It is mostly only a few feet above the sea, but the Broad
llill rises to 94 feet. Cattle shows, reviews, kc, are held
on the Links. To the north-west of the town, a Public
Recreation Park of 13 acres was laid out in 1872, at the
co-st of £3000, with walks, grass, trees, shrubs, and flowers.
Climate Daily observations from 1857 to 1872 ehow the mean
temperal"ure of Aberdeen for the year to be 45°"8 Fahr.,
for the three summer months 56° Fahr., and for the three
winter months 37°"3. The average yearly rainfall is 30'57
inches. Aberdeen is the healthiest of the large Scottish
towns. East winds prevail in spring.
Since 1867 £50,000 has been spent in constructing
main sewers throughout the city. A few acres of farm
laud have been irrigated by part of the sewage.
The city is governed by a corporation, the magistrates
and town councO, consisting of twenty-iive councillors,
including a provost, six bailies, a dean of guild, a trea-
surer, kc. The corporation revenue in the year 1871-72
was £11,498. The police, water, and gas are managed by
the council. The municipal and police burgh has an area
of nearly three square miles, with 12,514 municipal electors,
and with assessable property valued at £230,000 in 1873.
The Parliamentary burgh has an area of nine square miles,
including Old Aberdeen and Woodside, with 14,253 Par-
liamentary electors, and real property to the value of
£309,328 in 1873. It returns one member to Parliament.
The populafiou of Aberdeen in 1396 was about 3000; in
1643, 8750'; in 1708, 5556; in 1801, 26,i)92; in 1841,
03,262; and in 1871, 88,125; with 6718 inhabited
houses, 292 uninhabited, and 77 building.
Ol'l Abeedeex, Old, is a small, quiet, ancient town, a
Aberdeen, hurgh of barony and regality, a mile north of Aberdeen,
and as far south-west of the mouth of the Don. It mostly
forms one long street, 45 to 80 feet above the sea. The
Don, to the north of the town, runs through a narrow,
wooded, rocky ravine, and is spanned by a single Gothic
arch, the " Brig 0' Balgownie" of Lord Byron. The bridge
rests on gneiss, and is 67 feet wide and 34i feet h'"' .bove
the surface of the river, which at ebb tide is hert ^» feet
Jeep. The bridge is the oldest in the north of Scotland,
and is said to have been built about 1305 The funds
belonging to the bridge amount to £24,000.
The town was formerly the see of a bishop, and had a
large cathedral dedicated to St ilachar. In 1137 David L
translated to Old Aberdeen the bishopric, founded at
Mortlach in Banffshire ia 1004 by Malcolm IL in memory
of his signal victory there over the Danes. In 1153
Malcolm IV. gave the bishop a new charter.
ratliedral. The cathedral of St Macliar, begun about 1357, occupied
nearly 170 years in building, and did not remain entire
fifty years. What is still left is the oldest part, viz., the
nave and side aisles, 120 feet long and 621 feet broad,
now used as the parish church. It is chiefly built of
ouilayer granite stones, and while the plainest Scottish
cathedral, is the only one of granite in the kingdom. On
the flat pannellod ceiling of the nave are 48 heraldic shields
•■f the princes, nobles, and bishops who aided in its erection.
It has been lately repaired, and some painted window.'*
inserted, at the cost of £4280.
The chief structure Lq Old Aberdeen is the stately fabric King's
of Kirig's College cear the middle of the town. It fornia College,
a quadrangle, with interior court 103 feet square, two
sides of which have been rebuilt, and a projecting wing for
a Kbrary added since i860. The oldest parts, the Crovm
Tower and Chapel, date from about 1500. The former
is 30 feet square and 60 feet high, and is surmounted
by a structure about 40 feet high, consisting of a six-sided
lantern and a royal crown, both sculptured, and resting on
the intersections of two arched ornamented slips rising froai
the four comers of the top of the tower. The chapel, 120
feet long, 28 feet broad, and 37 feet high, stiU retains in
the choir the original oak canopied stalls, miserere seat, and
-lofty open screen. These fittings are 300 years old, in
the French flamboyant stylo, and are unsurpassed, in taste-
ful design and delicate execution, by the oak carving cf
any other old church in Europe. This carved woodwork
owes its preseiwation to the Principal of Sefonnation
times, who armed his people, and protected it from the
fury of the barons of the Meams after they had robbed
the cathedral of its beUa and lead. The chapel is still used
for public worship during the University session.
Connected with Old Aberdeen is a brewery in the town,
and a brick and coarse pottery work in the vicinity. There
are also a Free church, two secondary schools, and two
primary schocSs. Old Aberdeen has its own municipal
ofiicers, consisting of a provost, 4 bailies, and 13 councillors.
The town is drained, lighted, supplied with water, and is
-.vithin thp ParUamentary boundary of New Aberdeen.
There are several charitable institutions. Population in
1871, 1857 ; inhabited houses, 233. (a. c.)
ABERDEENSHIRE, a maritime county in the north-
east of Scotland, between 56° 52' and 57° 42' N. lat. and
between 1° 49' and 3° 48' long. W. of Greenwich. It is
bounded on the north and east by the Germ.in Ocean ; on
the south by tLie counties of Kincardine, Forfar, and Perth ;
and on the west by those of Inverness and Banff. Its
greatest length is 102 miles, and breadth 50 miles. Its
circuit with sinuosities is about 300 miles, 60 being sea-
coast. It is the fifth of Scotch counties in size, and is one-
sixteenth of the extent of Scotland. Its area is 1970
square miles, or 1,260,625 acres, of which, in 1872, 36'6
per cent., or 585,299 acres, were cultivated, 93,339 in woods
(mostly Scotch fir and larch), and 6400 in lakes. It con-
tains 86 civil parishes and parts of 6 others, or 101 parishes,
including civil and quoad sacra. The county b generally
hilly, and mountainous in the south-west, whence, ne.tr the
centre of Scotland, the Grampians send out various branchc.-i,
mostly to the north-east, through the county. The run of
the rivers and the general slope of the county is to the
north-east and east. It is popularly divided into five
districts : — First, Mar, mostly between the Dee and Don, Distfid^^
and forming nearly the south half of the county. It is
mountainous, especially Braemar, its west and Highlana
part, which contains the greatest mass of elevated land in
the British Isles. Here the Dee rises amid the grandeur
and wildness of lofty mountains, much visited by tourists,
and composed chiefly of granite and gneiss, forming many
high precipices, and sho«-ing patches of snow throughout
every summer. Here rises Ben Muichdhui, the second highest
mountain in Scotland and in the British Isles, 4296 feet ;
Eraeriach, 4225; Cairntoul, 4245; Cairngorm (famed for
" Cairngorm stones," a peculiar kind of rock crystal), 4090 ;
Bcn-a-Buird, 3800; Ben Avon, 3826; and Byron's "dark
Lochnagar," 3786. The soil on the Dee is sandy, and
on the Don loamy. The city of Aberdeen is in Mar.
Second, Formartin, between the lower Don and Ythaii.
with a sandy coast, succeeded by a clayey, fertile, tdlod
tract, and then by low hills, moors, mosses, and tilled land
Third, Buchan, north of the Ythan, and next in size to
44
ABERDEENSHIRE
Mar, tntb parts of the coxst bold and rocky, and with the
interior bare, low, flat, undulating, and in parts, peaty. On
the coast, 6ii miles south of Peterhead, are the Boilers of
Bnchan, — a basin in which the aca, entering by a natural
arch, boils up violently in stormy weather. Buchan Ness
is the castmost point of Scotland. Fourth, Garicch, a
beautiful, undulating, loamy, fertile valley, formerly called
the granary of Aberdeen, withihe prominent hill Benachie,
167C feet, on the south. Fifth, Slralhbogie, mostly con-
sisting of hills (The Buck, 2211 feet; Noath, 1830 feet),
moors, and mosses. The county as a whole, except the low
grounds of Buchan, and the Highlands of Braemar, consists
mainly of nearly level or undulating tracts, often nalced
and infertile, but interspersed with many rich and highly
cultivated spots.
Rivers. The chief rivers are the Dee, 96 miles long; Don, 78;
Vthan, 37, with mussel beds at its mouth; Ugie, 20; and
Deveron, 58, partly on the'boundary of Banffslwre. The
pearl mussel occurs in the Ythan and Don. A valuable
pearl in the Scottish croivTi is said to be from the Ythan.
Loc. Muick, the largest of the few lakes in the county,
1310 feet above the sea, is only 2| miles long and J to J
mile broad. The rivers havp ilenty of salmon and trout.
There are noted chalybeate _ rings at Peterhead, Fraser-
burgh, and Pananich near Ballater.
Oimate. The climate of Aberdeenshire, except in the mountainous
districts, is comparatively mild, from the sea being on two
sides. The mean annual temperature at Braemar is 43°'6
Fahr., and at Aberdeen 45°-8. The mean yearly rainfall
varies from about 30 to 37 inches. The summer climate
of the Upper Dee and Don valleys is the driest and most
bncing in the British Isles, and grain is cultivated up to
1600 feet above the sea, or 400 to 500 feet higher than
elsewhere in Korth Britain. All the crops cultivated in
Scotland ripen, and the people often live to a great age.
Geology. The rocks are mostly granite, gneiss, with small tracts of
syenite, mica slate, quartz rock, clay slate, grauwacke,
primary limestone, old red sandstone, serpentine, and trap.
Lias, greensand, and chalk flints occur. The rocks are
much covered with boulder clay, gravel, sand, and allu-
vium. Brick clay occurs near the coast. The surface of
the granite under the boulder clay often presents ghcial
sraoothings, grooves, and roundings. Cairngorm stone,
beryl, and amethyst are found in the granite of Braemar.
Plants and The tops of the highest mountains have an arctic flora.
Aniniais. At Her Majesty's Lodge, Loch Muick, 1350 feet above the
sea, grow larches, vegetables, currants, laurels, roses, <tc.
Some ash trees, 4 or 5 feet in girth, are growing at 1300
feet above the sea. The mole occurs at 1800 feet above
the sea, and the squirrel at 1400. Trees, especially Scotch
fir and larch, grow well in the county, and Braemar abounds
in natural timber, said to surpass any in , the north of
Europe. Stumps of Scotch fir and oak found in peat in
the county are often far larger than any now growing.
Grouse, partridges, and hares abound in the couuty, and
rabbits are often too numerous. Red deer abound in
Braemar, the deer forest being there valued at £5000 a
year, and estimated at 500,000 acres, or one-fourth the
arc.i "jf deer forests in Scotland.
Apncul- Poor, gravelly, clayey, and peaty soils prevail much more
ture. in Aberdeenshire than good rich loams, but tile draining,
bones, and guano, and the best modes of modern -tillage,
have greatly increased the pro<luce. Farm-houses and
steadings have greatly improved, and the best agricultural
implements and machines are in general use. About two-
thirds of the population depend entirely on agriculture, and
oatmeal in various forms, with milk, is the chief food of
farm-servants. Farms are generally small, compared with
those in the south-east counties. The fields are separated
by dry-stone dykes, and also by woo<len and wire fences.
Leases of 19 or 21 years prevail, and the five, eix, or seven
shift rotation is in general use. In 1872 there were 1I,C42
occupiers of land, with an average of 50 acres each, an3
paying about £630,000 in rent Of the 585,299 acres of
the county in crop in 1872, 191,880 acres were in oats,
18,930 in barley and bcre, 1G33 in rye, 1357 in wheat,
95,091 in turnips (being one-fifth of the turnips grown in
Scotland), 8414 in potatoes, 232,178 in grasses and clover.
In 1872 the county had 23,117 horses, 157,900 cattle
(being above one-seventh of all the cattle in Scotland),
123,308 sheep, and 13,579 pigs. The county is unsur-
passed in breeding, and unrivalled in feeding cattle, aud
this is more attended to than the cultivation of grain-crops.
About 40,000 fat cattle are reared, and above £1,000,000
value of cattle and dead meat is sent from the county to
London j early. The capital invested in agriculture within
the county is estimated at about £5,133,000.
The great mineral wealth in Aberdeenshire is its long- Mincralai
famed durable granite, which is largely q>iarried for biiild-
ing, paving, causewaying, and polishing. An acre of land
on being reclaimed has yielded £40 to £50 worth of causo-
waying stonea Gneiss is also quarried, as also primary
limestone, old red sandstone, conglomerate millstone, grau-
wacke, clay slate, syenite, and hornblende rock. Iron ore,
manganese, and plumbago occur in the county.
A Lirge fishing population in villnges along the coast FUberies.
engage in the white and herring fishery. Haddocks are
salted and rock-dried (speldings), or smoked (finnans). The
rivers and coasts yield many salmon. Peterhead was long
the chief British port for the north whale and seal fishery,
but Dundee now vies with it in this industry.
The manufactures and arts of the county are mainly Huinfae-
prosecuted in or near the town of Aberdeen, but throughout turc:.
the rural districts there are much milling of com, brick and
tile making, stone-quarrying, smith-work, brewing and
distilling, cart and farm implement making, casting and
drj-ing of peat, timber feUing, especially on Decside and
Donside, for pit-props, railway sleepers, lath, barrel staves,
(tc. The chief imports into the county are, coals, lime. Trade,
timber, iron, slates, raw materials of textile manufac-
tures, wheat, cattle-feeding stuS's, bones, guano, sugar, ■
alcoholic liquors, fruits, &c The chief exports are granite
(rough, dressed, -end polished), flax, woollen, and cotton
goods, paper, combs, preserved provisions, oats, barley,
520 fairs in the year for cattle, horses, sheep, hiring ser-
vants, ic.
Aberdeenshire communicates with the south by the £«i]*aya.
the east Grampians, the highest rising 2200 feet above the
sea. About 188 miles of railway ^the Great North of
Scotland, Formartin and Buchan, and Deeside lines), and
2359 miles of public roads, ramify through the county.
Tolls over the county were abolished in 1865, and the
roads are kept up by assessment. The railway lines in the
county have cost on the average about £13,500 a mile.
land Railway form the main exits from the county to the
north-west.
The chief antiquities in Aberdeenshire are Picts" houses Anti-
or weem^ stone foundations of circular dwellings; mono- quilies.
liths, some being sculptured; the so-called Druid circles;
stone cists; stone and earthen enclosures; the vitrified
forts of Dunnideer and Noath ; cairns ; crannoges ; earthen
mounds, as the Bass; flint arrow-heads; clay fimeral urns;
stone celts and hammers. Remains of Roman camps occur
at Peterculter, Kintore, and Auchterless, respectively 107 J,
100, and 115 acres. Roman arms have been found. Ruina
of ancient edifices occur. On the top of a conical hill called
Dunnideer. in the Garioch district, are the remains of ^
ABERDEENSHIRE
45
Kmincnt
men.
castle, supposed to be 700 years old, and surrounded by a
vitrified wall, which must be still older. The foundations
of two buildings stiU remain, the one in Braemar, and . the
other in the Loch of Cannor (the latter with the remains
of a wooden bridge between it and the land), which are
supposed to have belonged to Malcolm Canmore, King of
Scotland. The most extensive ruins are the grand ones of
KUdrummy Castle, evidently once a princely seat, and stilt,
covering nearly an acre of ground. It belonged to David
Earl of Huntingdon in 1150, and was the seat of the Earls
of Marr attainted in 1716. 'The Abbey of Deer, now in
ruins, was begun by Cumyn Earl of Buchan about 12 19i
In Roman times, Aberdeenshii'e formed part of Ves-
pasiana in Caledonia, and was occupied by the TaLxali, a
warlike tribe. The local names are mostly Gaelic. St
Columba and his pupil Drostan visited Buchan in the Gth
century. In 1052 Macbeth fell near the Peel Bog in
Lui'iphanan, and a cairn which raarks the spot is stiU
shown. In 1309 Bruce defeated Comyn, Earl of Buchan,
rear Inverurie, and annihilated a powerful Norman family.
In 1411 the Earl of Marr defeated Donald of the Isles in
the battle of Harlaw, near Inverurie, when Sir Robert
Davidson, Provost of Aberdeen, was killed. In 1562
occurred the battle of Corrichie on the Hill of Fare, when
the Earl of Murray defeated the Marquis of Huntly. In
1715 the Earl of Marr proclaimed the Pretender in Braemar.
In 1746 the Duke of Cumberland with his army marched
through Aberdeenshire to Culloden. In 1817 a base line
of verification, 5 miles 100 feet long, was measured in'con-
nection with the Trigonometrical Survey of the British Isles,
on the Belhelvie Links 5 to 10 miles north of Aberdeen.
Among eminent men connected with Aberdeenshire are,
Robert Gordon of Stralooh, who in 1648 published the first
atlas of Scotland from actual sjirvey ; the Earls Marischal,
whose chief seat was Inverugie Castle ; Field-Marshal
Keith, born at Inverugie Castle, 1696 ; Dr Thomas Reid,
the metaphysician, minister of New Machar 1737 to 1752 ;
Lord Pitshgo, attainted 1745; Sir Archibald Grant of
Monymusk, who introduced turnips into the coiinty 1756,
and was the first to plant wood on a great sc;Je ; Peter
Garden, Auchterless, said to have died at the age of 132,
about 1780; Rev. John Skinner, author of some popular
Scottish songs ; Morrison the hygeist ; the Earl of Aberdeen,
Prime Miaister during the Crimean war.
The native Scotch population of Aberdeenshire are long-
headed, shrewd, careful, canny, active, persistent, but
reserved and blunt, and vrithout demonstrative enthusiasm.
Thoy have a physiognomy distinct from the rest of the
Scottish people, and have a quick, sharp, rather angry
accent. The local Scotch dialect is broad, and rich in
diminutives, and is noted for the use of e for o or u, f for
kTi, d for th, &c. In 1830 Gaelic was the fireside language
almost every family in Braemar, but now it is little used.'
Courts and Aberdeenshire has a Lord-Lieutenant and 3 Vice and 60
Deputy-Lieutenants. The Supreme Court of Justiciary sits
in Aberdeen twice a-year to tiy cases from the counties of
Aljerdcen, Banff, and Kincardine. The counties of Aberdeen
and Kincardine are under a Sheriff' and tv/o Sheriffs-Substi-
tute. The Sheriff Courts are held in Aberdeen and Peter-
head. Sheriff Small-Debt and Circuit Courts are held at
seven places in the county. There are Burgh or Bailie Courts
in Aberdeen and the other royal burghs in the county.
Justice of the Peace and Police Courts are held in Aberdeen,
&c. The Sheriff Courts take cognisance of Commissaiy
business. During 1871, 994 persons were confined in the
Aberdeenshire prisons. In the year 1870-71, 74 parishes
in the county were assessed £53,703 for 7702 poor on the
Tioll and 1847 casual poor.
Aberdeenshire contains 105 Established churches, 99
Free. 31 Episcopal, 15 LTQJtgd Presbyterian, 9 Roman
Native
features.
Polico.
Cburchet.
Cathohc, and 31 of other denominations. This includes
detached parts of the two adjacent counties.
By the census of 1871, 84-83 per cent, of the children Ecicition.
in the county, of the ages 5 to 1 3, were receiving education.
Those formerly called the parochial schcolniasters of
Aberdeenshire participate in the Dick and Milne Bequests,
which contributed more salary to the schoolmasters in some
cdses than did the heritors. Most of the schoolmasters are
Masters of Arts, and many are preachers. Of 114 parochial
schools in the county befoi-e the operation of the new
Education Act, 89 received the Milne Bequest of £20 a
year, and 91 the Dick Bequest, averaging £30 a year, and
a schoolmaster with both bequests would have a yearly
income of £145 to £150, and in a few cases £250. The
higher branches of education have been more taught ia the
schools of the shires of Aoerdeen and Banff than in the
other Scotch counties, and pupils have been long in the
habit of going direct from the schools of these two counties
to the University.
The value of property, or real rental of the lands and Property,
heritages in the county (including the burghs, except that
of Aberdeen), for the year 1872-73, was £769,191. The
railway and the water works in the city and county were
for the same year valued at £11,133. For general county
purposes for the year ending 15th May 1872, there was
assessed £14,803 to maintain police, prisons, militia, county
and municipal buildings, <tc., and £19,320 to maintain
2359 miles of pubUc county roads.
The chief seats on the proprietary estates are — Balmoral Proprietora
Castle, the Queen ; Mar Lodge and Skene House, Earl
of Fife ; Aboyne Castle, Marquis of Huntly ; Dunecht
House, Earl of Crawford and Balcarres ; Keith Hall, Earl
of Kintore ; Slains Castle, Earl of Errol ; Haddo House,
Earl of Aberdeen ; Castle Forbes, Lord Forbes ; Philorth
House, Lord Saltoun ; Huntly Lodge, the Duke of Rich-
mond. Other noted seats are — Drum, Irvine ; Invercauld,
Farquharson ; Newe Castle, Forbes ; Castle Eraser, Eraser ;
Cluny Castle, Gordon ; Moldrum House, Urquhart ; Craiga-
ton Castle, Urquhart ; Pitfour, Ferguson ; Ellon Castle,
Gordon ; F3rvie Castle, Gordon. Ten baronets and knights
have residences in the county. Of the proprietors many
hvo permanently on their estates. Their prevailing names
are Gordon, Forbes, Grant, Eraser, Duff, and Farquharson.
Aberdeenshire has one city, Aberdeen, a royal parha- Burghs,
mentaiy .burgh ; three other royal parliamentary burghs,
Inverurie, Eontore, and Peterhead ; and seven burghs of
barony. Old Aberdeen, Charleston of Aboyne, Fraserburgh,
Huntly, Old Meldrum, Rosehearty, and Turriff.
The county sends two members to Parliament — one for
East Aberdeenshire, with 4341 electors, and the other for '
West Aberdeenshire, with 3942 electors. The county has '
also four parliamentary burghs, which, with their respective
populations in 1871, are — Aberdeen, 88,125; Peterhead,
8535; Inverurie, 2856; and Kintore, 659. The first
sends one member to Parliament, and the other three unite
with Elgin, Cullen, and Banff, in sending another.
By the census 1801 the county had 121,065 inhabitaiits,
and by that of 1871, 244,603, with 53,576 families. 111
females to 100 males, 34,589 inhabited houses, 1052 unin-
habited houses, and 256 building. In 1871 there were in
eight towns (Aberdeen, Peterhead, Fraserburgh, Huntly,
Inverurie, Old Meldrum, Turriff, and Now Pitsli2<^)i
111,978 inhabitants; in 32 villages, 19,561; and in nuol
districts, 113,064.
(New Statistical Account of Scotland, vol. xiL ; the charters
of the burgh; extracts from the Council Register down to
1625, and selections from the letters, guildry, and trca-
surcr'e accounts, forming 3 volumes of tho Spalding Club;
Collections for a History of the Shires of A. and Banff,
edited by Joseph Robertson,. Esq.,. 4to, Spalding Club;
Paillanien-
■ tary Tepro.
santation.
Population.
46
A B E — A B E
/leytftrum Epifeopntus Alcrdonensii, vols. L fiud ii., by
I'rof. Cosiao Innes, 4to, Spalding Club ; Tfie Jlistoryof A.,
by Walter Tliom, 2 vols. 1 2mo, 1811; Buchan, by the Rev.
John B. Pratt, 12ino, 1859; Historical Account and Delineo
lion of A., by Robert Wilson, 1822; First Report of Royal
Com. on Hist. MSS., 18G9; The Annals of A., by William
Kennedy, 1813; Orem's Description of the Chanonry, Cathe-
dral, and Kiwfs College of Old A., 1724-25, 1830; The
Castellated Architecture of A., by Sir Andrew Leith Hay
of Rannes, imp. 4to ; Specimens of Old Castellated Houses
of A., with drawings by GUcs, folio, 1838 ; Lipes of Eminent
,1/ctj of a., by Jan\c3 Bnice, 12mo, 1841). (a. c.)
ABERDEEN, Gkorgk Hamilton Gordon, Fouetu
Earl of, was bora at Edinburgh on the 28th January
178-1:. He was educated at Harrow School, and at St
John's College, Cambridge, where he gi'aduated in 1804.
ile succeeded hb) grandfather in the earldom in 1801, and
in the same year he made an extended tour through
.Europe, visiting France, Italy, and Greece. On his
return he founded the Athenian Club, the membership
of which was confined to those who had travelled in
Greece. This explains Lord Byi'ou's reference in the
English Bards aiul Scotch Reviewsrs to "the travelled
Thane, Athenian Aberdeen." Soon after his return he
contributed a very able article to the Edinburgh Review
(v.)l vi.), on Cell's Topography of Troy. Another
literary result of his tour was the publication in 1822 of
An Inquiry itito the Principles of BeaxUy in, Grecian Archie
lecture, the substance of which had appeared some years
before in the form of an introduction to a translation of
Vitruvius' Civil Architecture. In 180G, having been
elected one of the representative peers for Scotland, he
took his seat in the House of Lords on the Tory side.
raembora of the then predominant party, and in particular
■with Pitt, through the influence of his relative, the cele-
brated Duchess of Gordon. In 1813 he was intrusted
with a delicate and difficidt special mission to Vienna, the
object being to induce the Emperor of Austria to join the
alliance against his son-in-law Napoleon. His diplomacy
was comjJetely successful; the desired alliance was secured
by the treaty of TopUtz, which the Earl sign«d as repre-
sentative of Great Britain in September 1813. On his
return at the conclusion of the war, he was raised to a
British peerage, with the title of Viscount Gordon. Lord
Aberdeen was a member of the Cabinet formed by the Duke
of Wellington in 1S2S, for a short time as Chancellor of the
Duchy of Lancaster, and then as Foreign Secretary. He
was Colonial Secretary in the Tory Cabinet of 1834-5, and
a fain received the seals of the Foreign Office under Sir
Robert Peel's administration of 1841. The policy of non-
intervention, to which he stedfastly adhered in his conduct
of foreign affairs, was at once his strength and Ids we.ikness.
According to the popular idea, he failed to see the limita-
tions and exceptions to a line of policy v/hich ne;irly all
admitted to bo as a general rule both wise and just. On
the whole, his administration was perhaps more esteemed
abroad than at home. It has been questioned whether
uny English minister ever was on terms of greater
intimacy with foreign courts, but there is no substantial
warrant for tie charge of want of patriotism which was
sometimes brought against him. On the two chief ques-
tions of home politics which were finallj^ settled during
his tenure of office, ho was in advance of most of his
party. While the other members of the Government
yielded" Catholic Emancipation and the repeal of the Corn
Laws as unavoidable concessions, Lord Aberdeen spoke
and voted for both measures from conviction of iheir
justice. On the 13th June' 1843, he moved the second
reading of hia bill "to remove doubts re.-ipecti:iy the
admisjiion of ministers to benefices in Scolliind,'' and it
was passed into law in that session, though a eimilar
measure had been rejected in 1840. Ab the first proposal
did not prevent, so the passing of the Act had no effect m
healing, the breach m 'he Established Church of ScotLind
which occurred in 184o. On the defeat of Lord Derby's
government in 1852, the state of parties waa Buch as to
necessitate a coalition government, of which Lord Aber-
deen, in consequence of the moderation of hia views, was
the Peel party from the time of Sir Robert's death, but
his views on the two great questions of home policy above
mentioned rendered him more acceptable to the Liberals,
and a more suitable leader of a coalition goverrmient than
any other member of that party could have been. His
administration wiU chiefly bo remembered in connection
with the Crimean war, which, it is now generally believed,
might have been altogether prevented by a more vigorous
policy. The incompetence of various departments at
homo, and the gross mismanagement of the commissariat
in the terrible winter of 1854, caused a growing dissatis-
faction with the government, which at length found
emphatic expression in the House of Cominons, when a
motion submitted by Mr Roebuck, calling for inquiry, was
carried by an overwhelming majority. Lord Aberdeen
regarded the vote as one of no-confidence, and at once
resigned. From this period Lord Aberdeen took little part
in public business. In recognition of his services he
received, soon after his resignation, the decoration of the
Order of the Garter. He died December 13, 1860. Lord
Aberdeen was twice married, — first in 1805, to E daughter
of the first Marquis of Abercorn, who' died in 1812, and
then to the widow of Viscount Hamilton. He was suc-
ceeded in the title and estates by Lord Haddo, his son
by the second marriage
ABERDOUR, a village in the county of Fife, in Scot-
land, pleasantly situated on the north shore of the Firth
of Forth, and much resorted to for sea-bathing. It is 10
nules N.'W. of Edinburgh, with which there is a frequent
conjmunication by steamer.
ABERFELDY, a village in Perthshire, celebrated in
Scottish song for its " birks " and for the neighbouring
falls of Monuss. It is the terminus of a branch of the
Highland Railway.
ABERGAVENNY, a market town in Monmouthshire,
14 miles west of Monmouth, situated at the junction
of a small stream called the Gavenny, with the river Usk.
It is supposed to have been the Gohannium of the Romans,
so named from Gobannio, the Gavenny. The town wai
formerly walled, and has the remains of a castle built
soon after the Conquest, and also of a Benedictine monas
tery. The river Usk is hero spanned by a noble stone
bridge of fifteen arches. Two markets are held weekly,
and elegant market buildings have recently been erected.
There is a free grammar school, with a fellowship and
exhibitions at Jesus College, Oxford. No extensive
manufacture is carried on except that of shoes ; the town
owes its prosperity mainly to the large coal and iron
works in the neighbourhood. Abergavenny ia a poUiag
place for the county. Population of parish (1871), 631S.
ABERNETHY, a town in Perthshire, situated in the
parish of the same name, on the right bank of the Tay,
7 miles below Perth. The earliest of the Culdee houses
was founded there, and it is said to have been the capital of
the Pictish kings. It was long the chief seat of the Epis-
copacy in the country, till, in the 9th century, the bishopric
was transferred to St Andrews. There still remains at Aber-
nethy a curious circular tower, 74 feet high and 48 feet
in circumference, consisting of sixty-four courses of hewn
stone. A number of similar towers, though not so weD
A B E — A B E
47
built, are to be met witli in Irel.iiid, but there is only one
Dther m Scotland, viz., that at Brechin. Petria argues, iu
bis Round Towers of Ireland, that these structures have
been used as belfries, and also as keeps.
ABERNETHY, John,— a Protestant dissenting divine of
Ireland, was born at Coleraine, county Londonderry, Ulster,
where his father was minister (Nonconformist), on the
lyth October 1680. In his thirteenth year he entered a
student at the University of Glasgow. On concluding his
course at Glasgow he went to Edinburgh University,
thought-born, not verbal merely — struck the most eminent
of his contemporaries and even his professors. Returning,
home, he received licence to preach from his Presbytery
before ho was twenty-one. In 1701 he was urgently
invited to accept the ministerial charge of an important
congregation in Antrim ; and after an interval of two
years, he was ordained there on 8th Augast 1703. His
admiring biographer tells of an amount and kind of
work done there, such as only a man of fecund brain, of
large heart, of healthful frame, and of resolute will, could
have achieved. In 1717 he was invited to the congrega-
tion of Ushei'a Quay, Dublin, as colleague with Rev. Mr
Arbuckle, and contemporaneously, to what was called the
Old Congregation of Belfast. The Synod assigned him to
Dublin. He refused to accede, and remained at Antrim.
This refusal was regarded then as ecclesiastical high-
tre:ison; and a cont'-oversy of the most intense and dis-
proportionate character followed. The controversy and
quorrel bears the name of the two camps in the con-
flict, the "Subscribers" and the "Non-subscribers." Out-
and-out evangelical as John Abernethy was, there can ba
no question that he and his associates sowed the seeds of
that after-struggle in which, under the leadership of Dr
Henry Cooke, the Arian and Socinian elements of the Irish
Presbyterian Church were thrown out. Much of what he
contended for, and which the " Subscribers " opposed bitterly,
has been sDently granted in the lapse of time. In 1726 the
" Non-subscribers," spite of an almost wofuUy pathetic
pleading against separation by Abernethy, were cut off, with
due ban and solemnity, from the Irish Presbyterian Church.
In 1 730, spite of being a " JSTon-subscriber," he was called
by his early friends of Wood Street, Dublin, whither he
removed. In 1731 came on the greatest controversy in
which Abernethy engaged, viz., in relation to the Test Act
nominally, but practically on the entire question of tests
and disabilities. His stand was "against all laws that, upon
account of mere differences of religious opinions and forms
of worsTiip, excluded men of integrity and ability from
sen-ing their country." He was nearly a century in
denied that a Roman Catholic or Dissenter could be a
" man of integrity and ability." His Tracts — afterwards
collected — did fresh service, generations later. And so
John Abernethy through life waa over foremost where un-
popular truth and right were to be maintained; nor did he,
for sake of an ignoble expediency, spare to smite the highest-
seated wrongdoers any more than the hoariest errors (as he
believed). He died in 1740, having been tmco married.
(Kippis' Biog. Brit., s. v.; Dr Duchal's Life, prefixed to
Sermons; Diary in MS., 6 vols. 4to; History of Irish Pres-
bi/terian Church). (k. B. o.) ;
ABERNETHY, John, grandson of ihe preceding, an
eminent surgeon, was bom in London on the 3d of April
1764. His father was a London merchant Educated
at Wolverhampton Grammar School, ho was apprenticed
in 1779 to Sir Charles Blicke, a surgeon in extensive
practice in the metropolis. He attended Sir William
Blizzard's anatomical lectures at the London Hospital,
and was early employed to assist Sir William " de-
monstrator ;" he also attended Pott's surgical lectures at
St Bartholomew's Hospital, as well as the lectures of the
celebrated John Hunter. On Pott's resignation of the
oflice of surgeon of St Bartholomew's, Sir Charles Blicke,
who was assistant-surgeon, succeeded him, and Abernethy
was elected assistant-surgeon in 1787. In this capacity
ho began to give lectures in Bartholomew Close, which
were so well attended that the governors of the hospital
built a regular theatre (1790-91), and Abernethy thus
became the founder of tha distinguished School of St
Bartholomew's. He hold the office of assistant-surgeon of
the hospital for the long period of twenty-eight years, till, in
1815, ho was elected principal surgeon. He had before that
time been appointed surgeon of Christ's Hospital (1813),
and Professor of Anatomy and Surgery to the Royal
CoUege of Surgeons (1814). Abernethy had great fame
both as a practitioner and as a lectujer, his reputation iu
both respects resting on the efforts he made to promote
the practical improvement of surgery. His Surgical Ob-
servations on tlie Constitutional Origin and Treatment OJ
Local Diseases (1809) — known as "My Book," from the
great frequency with which ha referred his patients to it,
and to page 72 of it in particular, under that name — wad
one of the earliest popular works on medical science.
The views he expounds in it are based on physiological
considerations, and are the more important that the con-
nection of surgery with physiology had scarcely been
recognised before the time he wrote. The leading prin-
ciples on which he insists in " My Book " are chiotly these
two : — \st, That topical diseases are often mere symptoms
of constitutional maladies, and then can only be removed
by general remedies ; and Id, That the disordered state of
the constitution very often originates in, or is closely
allied to deranged states of the stomach and bowels, and
can only be remedied by means that beneficially affect the
functions of those organs. His profession owed him
much for his able advocacy of the extension in this way
of the province of surgery. He had gi'eat success as a
teacher from tha thorough knowledge he had of his
science, and the persuasiveness with which he enunciated
his \'iews. It has been said, however, that the influence
he exerted on those who attended his lectures was not
beneficial in this respect, that his opinions were delivered
so dogmatically, and all who differed from him were dis-
paraged and denounced so contemptuously, as to repress
instead of stimulating inquiry. It ought to be mentioned,
that he was the first to suggest and to perform the daring
operation of securing by ligature the carotid and the exter-
nal Uiac arteries. The celebrity Abernethy attained in
liis practice was duo not only to his great professional
skill, but also in part to the singularity of his manners.
He used great plainness of speech in his intercourse with
his patients, treating them often brusquely, and sometimes
even rudely. In the circle of his family and friends ha
was courteous and affectionate ; and in all his dealings he
was strictly just and honourable. He resigned his surgery
at St Bartholomew's Hospital in 1827, and his professor-
ship at the CoUege of Surgeons two years later, on account
of failing health, and died at his residence at Enfield
on the 20th of April 1831. A collected edition of his
works in five volumes was published in 1830. A bio-
graphy. Memoirs of John Abernethy, by George Macilwain,
F.R.C.S., appeared in 1853, and though anything but
satisfactory, passed through several editions.
ABERRATION, or (more correctly) the Aberration
op Light, is a remarkable phenomenon, by which stars
appear to deviate a little, in the course of a year, from
their true places in thiheavcns. It results from the eye
of the observer being carried onwards by the motion of the
earth nu its orbit, during the time that light takes to
48
A B E — A B 1
travel from the star to the earth. The effect of this com-
bination of motions may be best explained by a familiar illus-
tration. . Suppose a rain-drop falling vertically is received
in K tube that has a lateral
motion. In order that the
drop may fall freely do\ni
the axis of the tube, the
latter must be inclined at
such an angle as to move
from the position AD to BE,
and again to CF, in the
tiujcs the drop moves from
D to G, and from G to C.
The drop in this case, since
it moves down the axis all
the way, must strike the
bottom of the tube at C
in the direction FC. The
light proceeding from a star is not seen in its true direc-
tion, but strikes the eye obliquely, for a precisely similar
reason. If lines bo taken to represent the motions, so that
the eye is carried from A to C during the time that light
moves from D to C, the light will appear to the eye at C
to come, not from D, but from F. The angle DCF, con-
tained by the true and apparent dii-ections of the star, is
the aberration. It is greatest when the two motions are
at right angles to each other, i.e., when the star's longitude
is 90° in advance of, or behind, the heliocentric longitude
of the earth, or (which amounts to the same thing) 90°
behind, or in advance of, the geocentric longitude of the
sun. (See Astronomy.) Now, in the right-angled triangle
ACD, tan ADC {i.e., DCF) = j^ ; whence it appears that
the tangent of the angle of aberration (or, since the angle
is very small, the aberration itself) is equal to the ratio,
velocity of e.irth in orbit _, , , ., .>, ■•
i—^, — fT^-TT . The rate of the earth s motion
velocity 01 liglit
being to the velocity of light in the proportion of 1 to
10,000 nearly, the maximum aberration is small, amount-
ing to about 20--1 seconds of arc, — a quantity, hov.'cver,
which is very appreciable in astronomic^al obsci'vations.
Aberration always takes place in the direction of the
earth's motion; that is, it causes the stars to appear nearer
than they really are to the point towards whioh the earth
is at the moment moving. That point is necessarily on
the ecliptic, and 90° in advance of the earth in longitude.
The efl'ect is to make a star at the pole of the ecliptic
appear to move in a plane parallel to the ecliptic, so as to
form a small ellipse, similar to the earth's orbit, but having
its major axis parallel to the minor axis of that orbit, and
vice versd. As we proceed from the pole, the apparent
orbits the stars describe become more and more elliptical,
tin in the plane of the ecliptic the apparent motion is in
a straight line. The length of this line, as well as of the
major axes of the different ellipses, amounts, in angular
measure, to about 40" 'S. The stars thus ajjpear to oscil-
late, in the course of the year, 20"'4 on each side of their
true position, in a direction parallel to the plane of the
ecliptic, and the quantity 20" -4 is therefore called the
constant of aberration.
For the discovery of the aberration of light, one of the
finest in modern astronomy, we are indebted to the dis-
tinguished astronomer Dr Bradley. He was led to it, in
1727, by the result of observations he made with the view
of determining the annual parallax of some of the stars ;
that is, the angle subtended at these stars by the diameter
of the earth's orbit. He observed certain changes in the
positions of the stars that he could not account for. The
deviations were not in the direction of the apparent motion
that parallax would (nve rise to; and he bad no better
success in attempting -to explain the phenomenon by tho
nutation of the earth's axis, radiation, errors of obserw
tion, ic. At last the true solution of the difficulty occurred
t him, suggested, it is said, by the movements of a vane
on the top of a boat's mast. Roemer had discovered, a
quarter of a century before, that light has a velocity which
earth's motion, having a perceptible relation to that of
light, must affect the direction of the visual rays, and with
this the apparent positions of the stars. He calculated the
aberration from the known relative velocities of the earth
and of light, and the results agreed entirely with his
observations.
The observed effects of aberration are of importance as
supplying an independent method of measuring the velocity
of hght, but more particularly as presenting one of the few
direct proofs that can be given of the earth's motion round
the sun. It is indeed the most satisfactory proof of this
that astronomy furnishes, the phenomenon being quite in-
explicable on any other hypothesis.
ABEKYSTWITH, a municipal and parliamentary bo-
rough, market town, and seaport of Wales, in the county
of Cardigan, is situated at the western end of the Vale
of Ehcidol, near the confluence of the rivers Ystwilh
and Rheidol, and about the centre of Cardigan Bay. It
is the terminal station of the Cambrian Railway, and a
line to the south affords direct communication with South
Wales, Bristol, &c. The borough unites with Cardigan,
Lampeter, itc., in electing a member of Parliament. Coal,
timber, and lime are imported, and the exports are lead,
oak bark, flannel, and corn. The harbour has of hite been
much improved; and the pier, completed in ISCS, forms
an excellent promenade. There are many elegant build-
ings, and it has been proposed to establish here a Uni-
versity College of Wales. On a promontory to the S.W.
of the town are the ruins of its ancient castle, erected in
1277, by Edward I., on the site of a fortress of great
strength, built by Gilbert de Strongbow, and destroyed by
Owen Gwynedd. From its picturesque situation and
hertlthy climate, and the suitableness of the beach for
bathing, Aberystwith has risen into great repute as a
w.itering-place, and attracts many visitors. Much of the
finest scenery in Wales, such as the Devil's Bridge, &c.,
lies within easy reach. Population (1871), 6898.
ABETTOR, a law term implying one who instigates,
encourages, or assists another to perform some criminal
action. See Accessory.
ABEYANCE, a law term denoting the expectancy of an
estate. Thus, if hnds be leased to one person for life, with
reversion to another for years, the remainder for years ij
in abeyance till the death of the lessee.
ABGAR, the name or title of a line of kings of Edess.T
in Mesopotamia, One of them is known from a corre-
spondence he is said to have had with Jesus Christ. The
letter of Abgar, entreating Jesus to visit him and heal him
of a disease, and offering Him an asylum from the wrath
of the Jews, and the answer of Jesus promising to send a
disciple to heal Abgar after His ascension, are given by
Eusebius, who believed the documents to be genuine. The
same belief has been held by a few moderns, but there can
be no doubt whatever that the letter of Jesus at least is
apocryphal. It has also been alleged that Abgar possessed
a picture of Jesus, which the credulous may see either at
Rome or at Genoa. Some make him the possessor of the
handkerchief a woman gave Jesus, as He bore the cross,
to wipe the sweat from His face with, on which, it is
fabled, His features remained miraculously imprinted.
ABIAD, Bahr-el-, a name given to the western branch
of the Nile, above Khartoum. It is better known as the
AVhite Nile. See Nile.
A B I — A B I
49
ABIEfi. See Fm.
ABILA, a city of ancient Syria, the capital of the
tetrarchy of Abilene, a territory whose limits and extent it
is impossible not* to define. The site of Abila is indi-
cated by some ruins and inscriptions on the banks of the
miles from the latter city. Though the names Abel and
Abila differ in derivation and in meaning, their similarity
has given rise to the tradition that this was the scene of
Abel's death.
ABILDGAARD, Nikolaj, called "the Father of Danish
Painting," was bom in 1744. He formed his style on
that of Claude and of Nicolas Pousstn, and was a cold
theorist, inspired ndi by nature but by art. As a technical
painter he attained remarkable success, his tone being
very harmonious and even, but the effect, to a foreigner's
eye, is rarely interesting. His works are scarcely known
out of Copenhagen, where he won an immense fame in his
own generation, and where he died in 1809. He was the
founder of the Danish school of painting, and the master
of Thorwaldsen and Eckersberg.
ABIMELECH ('l^?"'?-'!. father of the king, or rather
perhaps hing-father), occurs first in the Bible as the name
of certain kings of the Philistines at Gerar (Gen. xx. 2,
xxi, 22, xxvi 1). From the fact that the name is applied
in the inscription of the thirty-fourth psahu to Achish, it
has been inferred with considerable probability that it was
used as the official designation of. the Philistinian kings.
The name was also borne by a son of Gideon, judge of
Israel, by his Shechemite concubine (Judges viLi. 31).
On the death of Gideon, who had refused the title of king
both for himself and his children, Abimelech set himself
to obtain the sovereignty through the influence of his
mother's relatives. In pursuance of his plan he slew
seventy of his brethren " upon one stone " at Ophrah,
Jothara, the youngest of'them, alone contriving to escape.
This is one of the earliest recorded instances of a practice
exceedingly common on the accession of Oriental despots.
Abimelech was eventually made king, although his election
was opposed by Jotham, who boldly appeared on Mount
Gerimn and told the assembled Shechemites the fable of
the trees desiring a king. At th« end of the third year
of his reign the Shechemites revolted, and under the
off the authority of Abimelech. In Judges is. there is
an account of this insurrection, which is specially interest-
ing oiving to the full details it gives of the nature of the
military operations. After totally destroying Shechem,
Abimelech proceeded against Thebez, which had also re-
volted. Here, while storming the citadel, he was struck on
the head by the fragment of a millstone thrown from the
wall by a woman. To avoid the disgrace of perishing by
Q woman's hand, he requested his armour-bearer to run
him through the body. Though the immediate cause of
his death was thus a sword-thrust, his memory was not
saved from the ignominy he dreaded (2 Sam. xi. 21). It
has been usual to regard Abimelech's reign as the first
ettempt to establish a monarchy in Israel. Tl;^ facts,
however, seem rather to support the theory of Ewald
(Gesch. ii. 444), that Shechem had asserted its independ-
ence of Israel, when it chose Abimelech as its king.
ABINGDON, a parliamentary and municipal borough
and market town of England, in Berkshire, on a branch
of the Thames, 7 miles south of Oxford, and 51 miles
jW.N.W. of London. It is a place of great antiquity, and
jwas an important town in the time of the Heptarchy. Its
i)ame is derived from an ancient abbey. The streets. whii:b
are well paved, converge to a spacious area, in v^hich the
market is held. In the centre of this area stands tho
jmarket-Jiouse. supported on lofty pillars, with a large hall
above, appropriated to the sTumner assizes for the county,
and the transaction of other pubhc business. The town
contains two churches, which are saiS to have been erected
by the abbots of Abingdon, one dedicated to St Nicholas
and the other to St Helena ; several charitable institutions,
and a free grammar school, with scholarships at Pembroke
CoUege, Oxford. In 1864 a memorial of Prince Albert
was erected at Abingdon, a richly ornamented structure,
surmounted by a statue of the Prince. Abingdon was
incorporated by Queen Mary. It sends one member to
Parliament, and is governed by a mayor, four aldermen,
and twelve councillors. In the beginning of the century
it manufactured much sail-cloth and sacking; but its chief
trade now is in corn and malt, cai-pets, and coarse linen.
It is a station on a branch of the Great 'V\'"estern Railway
Population (1871), 6571.
ABIOGENESIS, as a name for tne production of living
by not-living matter, has of late been superseding the less
accurate phrase " Spontaneous Generation." Professor
Huxley, who made use of the word in his presidential
address to the British Association in 1870, distinguished
Abiogenesis from " Xenogenesis " or " Heterogenesis,"
which occurs, or is supposed to occur, not when dead
matter produces living matter, but when a living parent
gives rise to offspring which passes through a totally
different series of states from those exhibited by the
parent, and does not return into the parent's cycle of
changes. When a " living parent gives rise to offspring
which passes through the same cycle of changes as itself,'
there occurs "Somogenesis." "Biogenesis" includes both
of these. Other names for Abiogenesis are Generatia
^quivoca, Generatio Primaria, Archigenesis (Urzeugung),
Archebiosis, &c. The question of Abiogenesis — whether
under certain conditions living matter is produced by not-
hying matter — as it is one of the most fundamental, is per-
haps also the oldest in Biology; but within recent years — •
partly because the means of accurate experimentation have
been increased and the microscope improved, and partly
because the question has been recognised in its impor-
tant bearings on evolution, the correlation of forces, and
the theory of infectious diseases — naturalists have been
led to bestow more attention upon it than at any previous
period. While, therefore, the doctrine of Abiogenesis
cannot be said to be either finally established or refuted,
it is at least reasonable to believe that we are gradually
advancing to a solution. Among the older observers
of phenomena bearing on the question may be named
Aristotle, who, with the ancients generally, favoured
Abiogenesis ; Eedi, the founder of the opposite view ;
Vallisnieri ; Buffon; Needham ; and SpaDanzani ; among
later observers, Schwann and Schulze, Schrceder and
Dusch, Pasteur, Pouchet, Haeckel, Huxley, Bastian, and
many others. The experiments and observations made by
these naturalists, and their results — the ingenious' ex-
pedients employed to prevent inaccuracy^ — the interesting
and often marvellous transformations which microscopista
declare they have witnessed — will be discussed in tho
article Histology ; here it will be enough to note the
general nature of the reasoniogs with which the opponents
and defenders of Abiogenesis support their views. The
opponents maintain that all trustworthy observationa
have hitherto shown living matter to have sprung from
pre-existing living matter ; and that the further we search
and examine, the smaller becomes the . number of those
organisms which we cannot demonstrate to have arisen from
living parents. They hold that seeming instances -^
spontaneous generation pre usually to be explained by the
germ-theory — the prefic nee of invisible germs in the air ;
and they call to their aid-sue^ high authorities as Pasteur
and TynddL The defenders of Abiogenesis, on tho othen
T. — 7
50
A B 1 — A li C
hand, v/liile interpreting the results of past obacrvabon
and experimeot in their own favour, are yet leas disposed
to rest on these, rather preferring to ar^ae from those
wide analogies of evolution and correlalaon which seem to
support their doctrine. Thus Hacckel expressly embraces
Abiogcnesis as a necessary and integral part of the theory
of universal evolution ; and Huxley, in the same spirit,
though from the opposite camp, confesses that if it were
given him to look beyond the abyss of geologically
recorded time to the still more remote period when the
earth was passing through physical and chemical con-
ditions, he should ejrpect to be a witness of the evolution
of living protoplasm from not-living matter. (Critiqves
and Addresses, p. 239.) From this point of view, of
course, any microscopic obiervatious that have been made
soera verj' limited and comparatively unimportant. The
Abiogenists, indeed, are not without arguments to oppose
the results of past observation that seem unfavourable to
their vieAvs ; they argue that, as yet, all the forms
observed and shown to be produced by Biogenesis are
forms possessing a certain degree of organi-sation, which
in their case makes Abiogeuesis unlikely, from the first ;
whereas it has not been shown that the simplest struc-
tures — the Monera — do not arise by Abiogenesis. But
it is not so much on grounds of fact and experiment the
defenders of the Abiogenesis theory are convinced of
its truth, as because it seems to gain confirmation from
reasonings of much ^vidcr scope; because Abiogenesis aids
the theory of evolution by tracing the organic into the
inorganic ; because it fosters the increasing unpopularity
of the hypothesis of a special " vital force;" and because,
if this theory of the " perpetual origination of low forms
of life, now, as in all past epochs," were established, it
would agree well with the principle of uniformity, and by
disclosing the existence of unknown worlds of material for
development, would relieve natural selection with its ay-sist-
ing causes from what many consider the too Herculean
labour of evolving aU species from one or a very few
primary forms. The fullest discussion of the subject of
Abiogenesis, from the Abiogonist's point of view, is to be
found in Dr Bastiau's Beginninya of Life. Professor
ing historical survey, as well as a masterly summary of
facts and arguments in favour of Biogenesis. For many
interesting experiments, see Nature, 1870-73.
ABIPDNES, a tribe of South American Indians, inhabit-
ing the territory lying between Santa F^ and St lago.
They originally occupied the Chaco district of Paraguay,
but were driven thence by the hostihty of the Spaniards.
According to M. Cobrizhoffer, who, towards the end of
last century, hved among them for a period of seven years,
they have many singular customs and characteristics.
They seldom marry before the age of thirty, are chaste
and otherwise virtuous in their lives, though they practise
infanticide, and are without the idea of God. "With the
Abipones," says Darwin, " when a man chooses a wife, he
bargains with the parents about the price. • But it fre-
quently happens that the girl rescinds what has been
agreed upon between the parents and bridegroom, obsti-
nately rejecting the very mention of marriage; She often
runs away and hides herself, and thus eludes the bride-
groom." The Abiponian women suckle those infants that
are spared for the space of two years, — an onerous habit,
which is believed to have led to infanticide as a means of
escape. The men are brave in war, and pre-eminently
experi in swimming and horsemanship. NumericaDy the
tribe is insignificant. M. Dobrizhoffer's account of the
Abiponians was translated into English by Sara Coleridge,
aX tlie suggestion of Mr Southey, in 1822.
ABJUILITTOX. See Ajllegiancb, Oath os.
ABKHASIA, or Abasia, a tract of Asiatic liosaia, on
the border of the Black Sea, comprehending between kt.
42° 30' and 41° 45' N. and between long. 37' 3' and 40° 36'
E. The high mountains of the Caucasus on the N. and
N.E. divide it from Circassia; on the S.K it is bounded
by Mingrelia ; and on the S. W. by the Black Sea. Though
the country is generally mountainous, there are some deep
well- watered valleys, and the clin.ato is mild. The soil
is fertile, producing grain, grapes, and other fruits.
Some of the inhabitants devote themselves to agriculture,
some to the rearing of cattle and horses, and not a few
support themselves by piracy and robbery. Honey is
largely produced, and is exported to Turkey; and excellent
arms are made. Both in ancient and in modem times
there has been considerable trafiic; in slaves. This country
was early known to the ancients, and was subdued by the
Emperor Justinian, who introduced civilisation and Chris-
tianity. Afterwards thi Persians, then the Georgians, and
more recently the Tvuks, ruled over the land. Under
the Turks Christianity gradually disappeared, and Moham-
medanism was intrvluced in its stead. By the treaties of
Akerman and AAvianople, Russia obtained possevsion of
the fortresses of this territory; but till the insurrection of
186G, the chiefs had almost unlimited power. The prin-
cipal town is Sukumkaleh. The population of Abkhasia
is variously stated at from 50,000 to 2r)0,000. See Pal-
grave's £ssays on Eastern Questions, 1872.
ABLUTION, a ceremonial purification, practised in
nearly every age and nation. It consisted in washing the
body in whole or part, so as to cleanse it symbolically
from defilement, and to prepare it for religious obsen'auces.
Among the Jews we find no trace of the ceremony in patri-
archal times, but it was repeatedly enjoined and strictly
enforced under the Mosaic economy. It denoted either —
(1.) Cleansing from the taint of an inferior and less pure
condition, and initiation into a higher and purer state, ao
in the case of Aaron and his sons on their being set apart
to the priesthood; or (2.) Cleansing from the soil of
common life, in preparation for special acts of worship, as
in the case of the priests who were commanded, upon pain
of death, to wash their hands and feet before approaching
the altar; or (3.) Cleansing from the pollution occasioned
by particular acts and circumstances, as in the case of the
eleven species of uncleanness mentioned in the Mosaic
law; or (4.) The absolving or purifying one's self from the
guilt of some particular criminal act, as in the case of
Pilate at the trial of the Saviour. The sanitary reasons
which, in a warm climate and with a dry sandy soil, ren-
dered frequent ablution an imperative necessity, must not
bo allowed to empty the act of its symbolic meaning. In
the Hebrew different words are used for the washing of
the hands before meals, which was done for the sake of
cleanliness and comfort, and for the washing or plunging
enjoined by the ceremonial law. At the same time it is
impossible to doubt that the considerations which made
the law so suitable in a physical point of view were present
to the mind of the Lawgiver when the rite was. enjoined.
Traces of the practice are to be found in the history of
nearly every nation. The customs of the Mohammedans,
in this as in other matters, are clcsely analogous to those
of the Jews. ^Yith them ablution must in every case pre-
c-ede the exercise of prayer, and their law provides that in
Vhe desert, where water is not to be found, .the Arabs may
perform the rite wi'th sand. Various forms of ablution
practised by different nations are mentioned in the sixth
book of the iEueid, and we are told that iEneas washed
his ensanguined hands after the battle before touching his
Penates. Symbolic ablution finds a pLice under the New
Testament dispensation in the rite of baptism, which is
observed, though with some variety of form and circum-
A B N — A B O
51
stances, throughout the whole Christian Church. By
Romau Catholics and Bitualists, the tenn ablution is
appUed to the cleansing of the chaHce and the fingers of
the celebrating priest after the administration of the Lord's
Supper.
ARN'F.R (^52?, father of light), first cousin of Saul
(1 Sam. xiv. 50) and commander-in-chief of his army.
The chief references to him during the lifetime of Saul are
found in 1 Sam, xvii. 55, and xxvi. 5. It was only after
that monarch's death, however, that Abner was brought
into a position of the first political importance. David,
who had some time before been designated to the throne,
was accepted '\.- king by Judah alone, and was crowned at
Hebron. T' - other tribes were actuated by a feeling
hostile to Judah, and, as soon as they had thrown off the
Philistinian yoke, were induced by Abner to recognise
Ishbosheth, the surviving son of Saul, as their king. One
engagement between the rival factions under Joab and
Abner respectively (2 Sam. ii 12) is noteworthy, inasmuch
as it was preceded by an encounter between twelve chosen
men from each side, in which the 'vhole twenty-four seem
to have perished. In the general engagement which fol-
lowed, Abner was defeated and put to flight. He was
closely pursued by Asahel, brother of Joab, who is said to
have been " light of foot as a wild roe." As Asahel would
not desist from the pursuit, though warned, Abner was
compelled to slay him in self-defence. This originated a
Joab, as next of kin to Asahel, was by the law and custom
of the country the avenger of his blood. For some time
afterwards the war wps carried on, the advantage being
invariably on the aide of David. At length Ishbosheth
lost the main prop of his tottering cause by remonstrating
with Abner for marrying Rizpah, one of Saul's concubines,
an alliance which, according to Oriental notions, implied
pretensions to the throne. Abner was indignant at the
rebuke, and unmediately transferred his allegiance to
David, who not only welcomed him, but promised to give
him the command of the combined armies on the re-union
of the kingdoms. Almost immediately after, however,
Abner was slain by Joab and his brother Abishai at the
gate of Hebron. The ostensible motive for the assassina-
tion was a desire to avenge Asahel, and this would be a
sufficient justification for the deed according to the moral
standard of the time. There can be little doubt, however,
that Joab was actuated in great part by jealousy of a new
and formidable rival, who seemed not unlikely to usurp
his place in the king's favour. The conduct of David
after the event was such as to show that he had no com-
plicity in the act, though he could not venture to punish
its perpetrators. The dirge which he repeated over the
grave of Abner (2 Sam. ui 33-4) has been thus trans-
lated : —
Should Abner die as a villain dies ? —
Thy hards — not boimd.
Thy feet — not brought into fetters :
As one falla before the sons of wickedness, fcllest thou.
AEO, a city and seaport, and chief town of the district
of the same name in* the Russian province of Finland, is
eituated in N. bt. 60° 26', E. long. 22° 19', on the Aura-
joki, about 3 miles from where it falls into the Gulf of
Bothnia. It was a place of importance when Finland
formed part of the kingdom of Sweden, and the inhabi-
tants of the city and district are mostly of Swedish descent.
By the treaty of peace concluded here between Russia and
Sweden on 17tli August 1743, a gieat part of Finland was
ceded to the former. Abo continued to be the' capital of
FinLind tUl 1819. In November 1827, nearly the whole
city was burnt down, the university and its valuable library
being entirely destioy e<t" " Before this calamity Abo coa.
tained 1100 houses, and 13,00C 'jihabitants ; and its
university had 40 professors, more th.in 500 students, and
a library of upwards of 30,000 volumes, together with a
botanical garden, an observatory, and a chemical laboratory.
The university has since been removed to Helsingfors.
Abo is the seat of an archbishop, and of the supreme court
of justice for South Finland; and it has ar cathedral, a
town-haU, and a custom-house. Sail-cloth, linen, leather,
and tobacco are manufactured; shipbuilding is carried on,
and there are ertensive saw-mills. There is also a large
trade in timber, pitch, and tar. Vessels drawing 9 or 10
feet come up to the town, but ships of greater draught are
laden and discharged at the mouth of the river, which
forms an excellent harbour and is protected. Population
in 1867, : 3,109.
ABOLITIONIST. See Slavery.
ABOMASUM, caillette, the fourth or rennet stomach of
Ruminantia. From the omasum the food is finally depo-
sited in the abomasum, a cavity considerably larger than
either the second or third stomach, although less than the
first. The base of the abomasum is turned to the omasum.
It is of an irregular conical form. It is that part of the
digestive apparatus which is analogous to the single stomach
of other Mammalia, as the food there undergoes the process
of chymification, after being macerated and ground down
in the thi'ee first stomachs.
ABOMET, the capital of Dahomey, in West Africa, is
situated in N. lat. 7°, E. long. 2° 4', about 60 miles
N. of Whydah, the port of the kingdom. It is a clay-
buUt town, surrounded by a moat and mud walls, and
occupies a large area, part of which is cultivated. The
houses stand apart; theie are no regular streets; and the
place is very dirty. It has four larger market-places, and
trade is carried on in palm-oil, ivory, and gold, Moham-
medan traders from the interior resorting to its markets.
The town contams the principal palace of the king of
Dahomey. It is the scene of frequent human sacrifices,
a " custom" being held annually, at which many criminals
and captives are slain; while on the death of a king a
" grand custom" is held, at which sometimes as many as
2000 victims have perished. The slave-trade is also pro-
secuted, and the efforts of the British Government to induca
the king to abolish it and the " customs" have proved un-
ABORIGINES, originally a proper name given to an
Italian people who inhabited the ancient Latium, or
country now called Campagna di Roma. Various deriva-
tions of this name have been suggested; but there can be
scarcely any doubt that th.^ usual derivation {ah origins) is
correct, and that the word simply indicated a settled tribe,
whose origm and earlier history were unknown. It is thus
the equivalent of the Greek autochthones. It is therefore,
strictly speaking, not a proper name at all, although, from
being applied to one tribe (or group of tribes), it came to
be regarded as such. Who the Aborigines werf, or whence
they came, is tmcertain; but various traditions that are
recorded seem to indicate that they were an Oscan oj
Opican tribe that descended from the Apennines int<
Latium, and united with some Pelasgic tribe to form the
Latins. The stories about .iEneas's landing in Itnly repr&
sent the Aborigines as at firet opposing and then coalescing
with the Trojans, and state that the united people thea
assumed the name of Latins, from their king Zatinus,
These traditions clearly point to the fact that the Latins
were a mixed race, a circumstance which is proved by the
structure of their language, in which we find numerous
words closely connected with the Greek, and also numerous
words that are of an entirely different origin. These non-
Greek words are mostly related to the dialect.? of the
52
A B O — A B R
Opican tribes. In modern tiirics tho tenn Abori'jinea has
been extended in eigniilcution, and is uiicd to indicate
the inhabitauta found in a country at ita first discovery, in
contradistinction to colonies or new races, the time of whose
introduction into the country is known.
ABORTION, in Midioi/ery (from aborior, I perish),
the premature separation and expulsion of the contents of
the pregnant uterus. When occurring before the eighth
lunar month of gestation, abortion ia the term ordinarily
employed, but subsequent to this period it is designated
premature labour. The present notice includes both these
terms. As an accident of pregnancy, abortion is far from
uncommon, although its relative frequency, as compared
with that of completed gestation, has been very differently
estimated by accoucheurs. It is more liable to occur in
the earlier than in the later months of pregnancy, and it
would also appear to occur more readily at tho periods
corresponding to those of the menstrual discharge. Abor-
tion may be induced by numerous causes, both of a local
and general nature. Malformations of tho pelvis, acci-
dental injuries, and the diseases and displacements to
which tho uterus is liable, on the one hand ; and, on the
other, various morbid conditions of the ovum or placenta
leading to the death of tho foetus, are among the direct
local caiises of abortion The general causes embrace
certain states of the system which are apt to exercise a
more or less direct influence upon the progress of utero-
gestation. A deteriorated condition of health, whether
hereditary or as the result of habits of Ufe, certainly pre-
disposes to the occurrence of abortion. SyphUis is known
to be a frequent cause of the death of the foetus. Many
diseases arising in the course of pregnancy act as direct
exciting causes of abortion, more particularly the eruptive
fevers and acute inflammatory affections. Prolonged
irritation in other organs may, by reflex action, excite
the uterus to expel its contents. Strong impressions
made upon the nervous system, as by sudden shocks and
mental emotions, occasionally have a similar effect Further,
certain medicinal substances, particularly ergot of rye,
borax, savin, tansy, and cantharides, are commonly be-
lieved to be capable of exciting uterine action, but the
effects, as regards at least early pregnancy, are very un-
certain, while the strong purgative medicines sometimes
employed with the view of procuring abortion have no
effect whatever upon the uterus, and can only act remotely
and indirectly, if they act at all, by irritating the alimen-
tary canaL In cases of poisoning with carbonic acid,
abortion has been observed to take place, and the experi-
ments of Dr Brown Sequard show that anything inter-
fering with the normal oxygenation of the blood may
cause the uterus to contract and expel its contents. Many
cases of abortion occur vrithout apparent cause, but in
such instances the probability is that some morbid condition
of the interior of the uterus exists, and the same may be
said of many of those cases where the disposition to abort
has become habitual. The tendency, however, to the
recurrence of abortion in persons who have previously
miscarried is well known, and should ever be borne in
mind with the view of avoiding any cause likely to lead
to a repetition of the accident. Abortion resembles ordi-
nary labour in its general phenomena, excepting that in
the former hemorrhage often to a large extent forms one
of the leading symptoms. The treatment of abortion
embraces the meams to be used by rest, astringents, and
sedatives, to prevent the occurrence when it merely
threatens ; or when, on the contrary, it is inevitable, to
accomplish as speedily as possible the complete removal
of the entire contents of the uterus. The artificial induc-
tion of premature labour is occasionally resorted to by
aoooucheuTB jmder certain conditions involving the safety
of tlic mother or the fiEtus. For Criminal Abortion, fct
Medicax Jueibpeudence.
ABOUKIIl, a small village on the coast of Egypt, 1 3
miles N.E. of Alexandria, containing a ciistle which wai
used as a state prison by Mehemet Ali. Near the village,
and connected with the shore by a chain of rocks, is a
small island romaikable for remains of ancient buildings.
Stretching to tho eastward as far as tho Rosetta mouth of
the Nile is the spacious bay of Aboukir, where Nelson
fought " the Battle of the Nile," defeating and almost
destroying the French fleet that had conveyed Napoleon
to Egypt. It was near Aboukii that tho expedition to
Egypt, under Sir Kalph Abercromby, in 1801, effected a
landing in the face of an opposing force.
ABRABANEL, Isaac (called also Abravanel, Abarbanel,
Barbanella, and Ravanella), a celebrated Jewish statesman,
philosopher, theologian, and commentator, was bom at
Lisbon in 1437. He belonged to an ancient family that
claimed descent from the royal house of David, and his
parents gave him an education becqming so renowned a
lineage. He held a high place in the favour of King
Alphonso v., who intrusted him with the management of
important state affairs. On the death of Alphonso in
1481, his counsellors and favourites were harshly. treated
by his successor John ; and Abrabauel was, in consequence,
compelled to flee to Spain, where he held for eight years
(1484-1492), the post of a minister of state under Ferdi-
nand and Isabella. When the Jews were banished from
Spain in 1492, no exception was made in Abrabanel's
favour. Ho afterwards resided at Naples, Corfu, and
Monopoli, and in 1503 removed to Venice, where he held
office as a minister of state till his death in 1508. Abra-
banel was one of the most learned of the rabbis. HLs
writings are chiefly exegetical and polemical ; he displaj's
in them an intense antipathy to Christianity, though he
lived on terms of friendship with Christians. He wrote
commentaries on the greater part of the Old Testament,
in a clear but somewhat diffuse style, anticipating much
that has been advanced as new by modern theologians.
ABRACADABRA, a meaningless word once supposed
to have a magical efficacy as an antidote against agues and
other fevers. Ridiculously minute directions for the
proper use of the charm are given in, the Praicepta de
Medicina of Serenus Sammonicus. The paper on which
the word was written had to be folded in the form of
a cross, suspended from the neck by a strip of linen so as
to rest on the pit of the stomach, worn in this way for
nine days, and then, before sunrise, cast behind the wearer
into a stream running to the east. The letters of this word
were usually arranged to form a tiiangle in one or other of
the following ways : —
ABEACUJABE
CAn
ABEACA
A
ABEAO
ABEA
ABB
'
ABRAHAM or ABRAJf, father of the Israelite race,
was the first-born son of Terah, a Shemite, who left Ur
of the Chaldees, in the north-east of Mesopotamia, along
with Abram, Sarai, and Lot, and turned westwards in the
direction of Canaan. Abram had married his haJf-sistei
Sarai, who was ten years younger than himself ; and
though such relationship was afterwards forbidden by the
law. it was common in ancient times, both among othei
A B R A K A M
63
peoples, and among the Hebrews tliemselTea at leasi; oefora
Mosea. The cause of Terah's removing from his native
country ia not given. Having come to Haran, ho abode
there till his death, at the age of 205. According to
Genesis xii., Abram left Haran when he was 75 years of
age, that is, before the death of his father, in consequence
of a divine command, to which was annexed a gracious
promise, " And I wiU make of thee a great nation, and I
will bless thee, and make thy name great ; and thou shalt
be a blessing. And I will bless them that bless thee, and
Gurso him that curseth thee ; and in thee shall all families
of the earth be blessed " (xii. 2, 3). Another tradition
makes him leave Haran only after Terah's decease (Acta
vii. 4). The later account is that Abram's departure was
the result of religious considerations, because he had
already become emancipated from surrounding idolatry.
Perhaps the desire of a nomadic life, the love of migration
natural to an Oriental, had more to do with his pilgrimage
than a spiritual impulse from within ; but it is likely that
his culture advanced in the course of his sojournings, and
that he gradually attained to purer conceptions of duty
and life. Traditions subsequent to the Jehovistic represent
him as driven forth by the idolatrous Chaldeans (Judith
V. 6, &c.) on account of his monotheistic doctrines, and
then dwelling in Damascus as its king (Josephus's Anti-
quities, i. 7). The true cause of departure may be sug-
gested by Nicolaus of Damascus saying that he came out
of Chaldea with an army. The leader of a horde, worsted
ia some encounter or insurrection, he emigrated at the
word redeemed, in Isaiah xxix. 22, out of which Ewald
conjectures so much, as if Abram had been rescued from
great bodily dangers and battles, does not help the portrait,
because it means no more than the patriarch's migration
from heathen Mesopotamia into the Holy Land. Journey-
ing south-west to Canaan with his wife and nephew, he
arrived at Sichem, at the oak of the seer or prophet, where
Jehovah appeared to him, assuring him for the first time
that his seed should possess the land he had come to.
He travelled thence southward, pitching his tent east of
Bethel. Still proceeding in the same direction, ho arrived
at the Negeb, or most southern district of Palestine,
whence a famine forced him down to Kgypt. His plea
that Sarai was his sister did not save her from Pharaoh ;
for she was taken into the royal harem, but restored to
her husband in consequence of divine chastisments inflicted
upon the lawless possessor of her person, leading to the
discovery of her true relationship. The king was glad to
send the patriarch away under the escort and protection
of his men. A similar thing is said to have subsequently
hiippened to Sarai at Gerar with the Philistine king
Abimelech (Genesis sx.), as also to Rebekah, Isaac's wife
(xxvi.) The three narratives describe one and the same
event in different shapes. But the more original (the
junior Elohistic)' is that of the 20th chapter, so that Gerar
was the scene, and Abimelech the offender; while the later
Jehovistic narrative (xii.) deviates still more from veri-
similitude. Though this occun'ence, however, belongs to
the southern borders of Palestine, wo need not doubt the
fact of Abram's sojourn in Egypt, especially aa ho had an
Egyptian slave (Genesis xvi.) How long the patriarch
remained there is not related ; nor are the influenoes which
the religion, science, and learning of that civilised land
had upon him alluded to. That they acted beneQcially
apon his mind, enlightening and enlarging it, can scarcely
be doubted. His religious conceptions were transformed.
' Three documents at least ftre traconble in tlio Pent.iteuch; the
Elohistir, the junior Elohistic, and the Jehovistic. These were put
together by a redactor. Nearly tho whole of the fifth book w:ia
«lduU by the DouteroDomi^t.
The manifold wisdom of Egypt impressed him. Inter-
course with men far advanced in civilisation taught him
much. Later tradition speaks of his communicating U>
the Egyptians the sciences of arithmetic and astronomy
(Josephus i. 7) ; but this is founded upon the motion
entertained at the time of the civilised Chaldeans of
Babylon, whereas Ur of the Chaldees was a district
remote from the subsequent centre of recondite knowledge.
Abram received more than he imparted, for the Egyptians
were doubtless his superiors in science. He found the
rite of circumcision in use. There, too, he acquired great
substance — flocks and herds, male and female slaves.
After returning to Canaan, to his former locality, Abram
and Lot separated, because of disputes between their
herdsmen, there not being sufficient room for all their
cattle in common. After this separation the possession of
Canaan was again assured to Abram and t6 his seed, who
should be exceedingly numerous. This is the third
theocratic promise he received. He is also commanded
by Jehovah to walk through it in its length and breadth
as a token of inheritance, — a later Jehovistic tradition that
must be judged according to its inherent verisimilitude.
Abram settled again at the oak of Mamre near Hebron.
prisoner ia the expedition of the kings of Shinar, Ellasar,
Elam, and Goyim, against the old inhabitants of Basan,
Ammonitis, Ivloabitis, Edomitis, and others besides, Abram
gave chase to the enemy, accompanied by his 318 slaves
and friendly neighbours, rescuing his nephew at Hobah,
near Damascus. On his return, the royal priest Melchizedek
of SalMn came forth to meet him with refreshments, blessed
the patriarch, and received from him the tithe of the spoUa.
The king acted generously towards the victor, and was still
more generously treated in return.
Jehovah again promised to Abram a numerous ofi"spring,
with the possession of Canaan. He also concluded a
covenant vrith him in a solemn form, and revealed the
fortunes of his posterity in Egypt, with their deliverance
from bondage. Ia consequence of the barrenness of
Sarai, she gave her handmaid Hagar to Abram, who,
becoming pregnant- by him, was haughtily treated by her
mistress, and fled towards Egypt. But an angel met
her in the desert and sent her back, telling of a numerous
race that should spring from her. Having returned, she
gave birth to Ishmael, ia the 8Gth year of Abram's age.
Again did Jehovah appear to the patriarch, promising as
before a multitudinous seed, and changing his name in
conformity with such promise. He assured him and bis
posterity of the possession of Canaan, and concluded a
covenant with him for aU time. At the institution of
circumcision on this occasion, Sarai's name was also changed,
because she was to be the maternal progenitor of the
covenant people through Isaac her son. Abram, and all
the males belonging to him, were then circumcised. He
had become acquainted vdlh the rite in Egyjjt, and trans-
ferred it to his household, making it a badge of distinction
between the worshippers of tho true God and the idolatrous
Canaanites — the symbol of the flesh's subjection to the
spirit. Jts introduction into the worship of the colony at
Mamre indicated a decided advance in Abram's religious
conceptions. He had got beyond the cruel practice of human
sacrifice. The gro.ss worship of the Canaanites was left
behind; and the small remnant of it which he retained com-
ported with a faith approaching monotheism. Amid pre-
vailing idolatry this institution was a protection to his
family and servants — a magic circle drawn around them.
But, though powerful and respected wherever his name
was known, he confined tlio rito to his own domestics,
without attempting to force it on the inhabitants of
tho land where he sojourned. The punishment of dcatJi
54
ABRAHAM
for neglecting it, because the uncircumciaea person -was
thought to bo a breaker of the covenant and a despLser
of its Author, seems a. harsh measure on the part of
Abram; yet it can hardly bo counted an arbitrary trans-
ference of tho later Levitical severities to the progenitor of
the race, since it is in the Elohist.
Accompanied by two angeb, Jehovah appeared again to
Abram at tho oak of Mamre, accepted his proposed hospv-
tality, and promLsed him a eon by Sarai within a year.
Though she laughed incredulously, the promise *as definitely
repeated. When the angels left, Jehovah communicated
to Abram the divine purpose of destroying the dwellets
in Siddim because of their wickedness, but acceded to the
patriarch's intercession, that the cities of the plain should
bo spared if ten righteous men could bo found in them.
I'he two angels, who had gone before, arrived at Sodom in the
evening, and were entertained by Lot, but threatened with
shameful treatment by tho depraved inhabitants. Seeing
that the vengeance of Heaven was deserved, they proceeded
to execute it, saving Lot with his wife and two daughters,
and sparing Zoar as a place of refuge for them. Jehovah
rained down fire and brimstone from heaven, turning all
the Jordan district to desolation, so that when Abram
looked next morning from tho spot where Jehovah and
himself had parted, he saw a thick smoke ascend from the
ruins.
Abram then journeyed from Hebron to tho Ncgob, settled
between Kadesh and Shur in Gerar, where Sarai is said to
have been treated as a prior account makes her to have been
in Egypt. At the patriarch's prayer the plague inflicted on
the king and his wives was removed. This is a duplicate of
the other story. Whatever historical truth the present nar-
rative has belongs to an earlier period of Abram's life. His
second removal to Gerar originated in the former journeying
through it into Egypt. He must have remained in the neigh-
bourhood of Hebron, his first settlement, where Isaac was
born according to the Elohistic account. After the birth of
the legitimate heir, succeeding events were the expulsion of
Hagar and Ishmael from the paternal home, and the making
of a covenant between Abimelech and Abram at Beersheba.
Hero Abram " called on the name of the Lord," and is
said to have planted a noted tamarisk in commemoration
of the event.
Abram was now commanded by God to offer up Isaac in
the laud of Moriah. Proceeding to obey, he was prevented
by an angel just as he was about to slay his son, and
sacrificed a ram that presented itself at the time. In
reward oi his obedience he received the promise of a numer-
ous seed and abundant prosoerity. Thence he returned to
Beersheba.
Sarai died and was buried in the cave of Macnpelah near
Hebron, which Abram purchased, with the adjoining field,
from Ephron the Hittite. . The measures taken by the
patriarch for the marriage of Isaac are circumstantially
described. , His steward Eliezer was sent to the country
and kindred of Abram to find a suitable bride, which he
did in Haran, whither he was divinely conducted. Eebekah
appeared as the intended one; she parted from Bethuel
and her. family with their fuU approbation, was brought
to Isaac, and became a maternal ancestor of the chosen
people.
It is curious that, after Sarah's aeath, Abram should
have contracted a second marriage with Keturah, and
liegotten six sons. The Chronicles," however, make her
his concubine (1 Chron. L 32), so that these children may
have been born earlier. Probably the narrative intends
to account for the diffusion of Abram's posterity in Arabia.
Keturah's sons were sent away with gifts from their home
into Arabia, and aU the father's substance was given
to Isnac. The patriarch died at the age of 175 years,
and woA buried by I^aac and Ishmael beeido Sarai is
^fachpelah. I'he book of Genesis gives two lists of Arab
tribes, descended partly from Abram and Eeturah, partly
from him and Hagar or IshmaeL These dwelt in Arabia
Deserta and Petrxa, as also in the northern "half of Arabia
Welii.
1. We cannot adopt the opinion of Von Bohlen and Dozy
tliat Abram is a mythical person. Ho must be regarded as a
historical character, though the accounts of his life have
mythical elements intermingled with much that is tradi-
tional or legendary. The difficulty of separating the historic
from the merely traditional, hinders the presentation of a
natural portrait Later legends have invested him with ex-
traordinary excellence. They have made him a Worshipper '
of Jehovah, a prophet, the friend of God, favoured with
visible manifestations' of His presence, and receiving
repeated promises of the most far-reaching character. He
is the typical ancestor of tho chosen race, living under the
constant guidance of God, prospering in worldly goods,
delivered from imminent perils. A superhuman halo
surrounds him. It is the Jehovist in particular who
invests him with the marvellous and improbable, con-
necting him with altars and sacrifices — a cultus posterior
to both his time and mental development — making him
the subject of theoplianies, talking familiarly to Jehovah
himself, and feeding angels with flesh. The Elohist's
descriptions are simpler. Hiq patriarchs are usually colour-
less men, upright and plain. Th^y hav^ neither char-
acteristic features nor distinct outline. Abram stands
out an honest, peaceable, generous, high-minded patriarch;
a prince, rich, powerful, and honoured, fitted for rule,
and exercising it with prudence. Wo need not expect
a full history of the man from writers long posterior, the
representatives of popular traditions. Only fragments
of the life are given, designed to . show his greatness.
Legend assigned ideal lineaments to the progenitor whom
a remote antiquity shrouded with its hoary mantle, and
thus he became a model worthy of imitation.
2. The biblical sources of his biography are three at
least; and sometimes all appear in a single chapter, a£ in
Gen. xxii., which describes the severest trial of faith. The
oldest or Elohim-document h seen in verses 20-24, which
link on to chap. xxi. 2-5, from the same. The rest of the
chapter belongs to the junior Elohist, except verses 14^18,
added by the Jehovist to connect Abram's sacrifice ^-ith
Jerusalem These different documents, out of which the
general narrative was finally put together by a redactor,
create diversities and contradictions. Thus the Elohist
makes Abram laugh at the announcement of a son by Sarai
(xviL 17); the Jehovist, jealous for the patriarch's honour,
assigns the laughter to the woman as a sign of incredulity
(xviii. 12).
3. The account of the change of names given to Abram
and Sarai when circumcision was instituted, cannot be
regarded as historical The Elohist says that Abram became
Abraham, the latter meaning /a<A«r of tnuch people. But
the Hebrew tongue has no word rahdm, and no root with
the three letters cm. Hence the Jews found the etymo-
logy a puzzle.* The old reading was undoubtedly Abram
and Sarai, though the later Jews expressly forbade Abram
either in speaking or writing. The difference is one of
mere orthography. The forms om and on are cognate
ones, as are m:? and nTi7. The ctjonologising propensity
of the Elohist is well known. The names signifv/a/A<r <j/
heif//U and pnncess respectively.
4. The religion of Abram was not pure Jehovism. Ac-
cording to Exodus vi 3, the name Jehovah was unknown
before Moses. Pure Jehovism was a growth not reached
2 See Beer'a Ltbcn AhraJiaiAs, pp. 150, 161.
A B E — A B E
55
before the prophets. It was a late development, the creed
of the most spiritual teachers, not of the people generally.
Abram was a. distinguished Orieutal sheikh, who laid aside
the grossness of idolatry, and rose by degrses, through ooa-
tact with many peoples and his own reflection, to the con-
ception of a Being higher than the visible world, the Gcd
of the light and the sun. He was a civilised nomad,
having wider and more spiritual aspirations than the
peoples with whom' he livedo As a worshipper of God,
his faith was magnified by later ages throwing back
their more advanced ideas into his time, because ho was
the founder of a favoured race, the type of Isiael as
they were or shoxild be.
5. The leading idea forming the essence of the story re-
Bpecting Abram's sacrifice of Isaac, presents some difficulty
of explanation. The chapter did not proceed from the
earliest writer, but from one acquainted with the institu-
tion of animal sacrifices. That the patriarch was familiar
with human sacrifices among the peoples round about is
beyond a doubt. Was he tempted from within to comply,
on one occasion, with the prevailing custom; or did the
disafi'ected Canaanites call upon him to give such proof
of devotion to his God 1 Perhaps there was a struggle in
his mind between the better ideas which led to the habitual
renunciation of the barbarous rite, and scruples of the uni-
versal impropriety attaching to it. The persuasion that it
could never be allowed may have been shaken at times.
The general purport of the narrative is to place in a strong
light the faith of one prepared to make the most costly
sacrifice in obedience to the divine command, as well as
God's aversion to human offerings.
6. It is impossible to get chronological exactness in
Abram's biography, because it is composed of difi'erent tra-
ditions incorporated with one another, the product of dif-
ferent times, and all passing through the hands of a later
redactor for whom the true succession of events was not
of primary importance. The writers themselves did not
know the accurate chronology, having to do with legends
as well as facts impregnated with the legendary, which the
redactor afterwards altered or adapted. The Elohist is
much more chronological than the other writers. It is
even impossible to teU the time when Abram lived. Ac-
cording to Lepsius, he entered Palestine 1700-1730 B.C. ;
according toBunsen, 2886 ; while Schenkel gives 2 130-2 140
B.C. In Beer's Leben Abraham's his birth is given 1948
A.M., i.e., 2040 B.C.
7. The Midrashim contain a good deal about Abram
which is either foumded on biblical accounts or spun out
of the fancy. Nimrod was king of Babylon at the time.
The patriarch's early announcement of the doctrine of one
God, his zeal in destroying idols, including those worshipped
by his father, his miraculous escape from Nimrcd's wrath,
his persuading Terah to leave the king's service and go
with him to Canaan, are minutely told. During his life
he had no fewer than ten temptations. Satan tried to ruin
him, after the fiend had appeared at the great feast given
when Isaac was weaned, in the form of a poor bent old man,
who had been neglected We can only refer to one speci-
men of rabbinic dialogire-making. God appeared to
Abram by night, saying to him, " "Take thy son" — (Abram
interrupting), " Which 1 I have two of them." The voice
of God — " Him who is esteemed by you as your only .son."
Abram — " Each of them is the only son of his mother."
God's voice — " Him whom thou lovest." Abram — " I love
both." God's voice — " Him whom thou especially lovest."
Abram — " I cherish nry children with like love." God's
voice — " Now, then, take Isaac." Abram — " And what
shall I begin with in himf God's voice — " Go to the lund
where at my call mountains will rise up out of valleys
...... to Moriih. and oficr thy son Isaac as a holocaust."
Abram — "Is it a sacrifice I .shall offer. Lord? Where is the
priest to prepare it V " Be thou invested vrith that dig-
nity as Shem was formerly." Abram — " But that land
counts Beveral' mountains, which shall I ascend 1" "The
top of the mountain where thou shalt see my glory veiled
in the clouds," &c (Beer, pp. 59, 60.)
The Arabic legends about Ibrahim are mostly taken from
the Jewish fountain, very few being independent and pre-
Islamito. Mohammed collected all that were current, and
presented them in forms best suited to his purpose. His
sources were the biblical accounts and later Jewish legends.
Those about the patriarch building the Kaaba along with
Ishmael, his giving this son the house and aD the country
in which it was, his going as a pilgrim to Mecca every
year, seeing Ishmael, and then retm-ning to his own land,
Syria, his foot-print on the black stone of the temple,
and similar stories, are of genuine Arabic origin. The
rest are Jewish, with certain alterations. The collected
narratives of the Arabic historians are given by Tabari,
constituting a confused mass of legends drawn from the
Old Testament, the Koran, and the Babbina. (See
Ewald's Geschichie des Yolkes Israel, vol L pp. 440-484,
third edition ; Bertheau's Zur Geschichie der Israelites,
p. 206, et seq.; Tuch's Kommentar ueber die Genesia,
1838: Knobel's Die Genesis, 1852; Doz/s Die Israeliten
m Mekka, p. 16, et seq.; B. Beer's Leben Abraham's
nach Auffassung der jiidijschen Sage, 1859 ; Chrrniique
iAbou Djafar Mohammed Tahari, par L. Dubeux, tome
premier, chapters 47-60; Chwolson's Ssabier vrid der
Ssabismus, vol. ii.) (s. D.)
ABRAHAM-A-SANCTA-CLARA, was horn at Krahen-
heimstetten, a village in Snabia, on the 4th of June 1642.
His family name was Ulrich Megerle. In 1662 ho joined
the order of Barefooted Augustinians, and assumed the
name by which alone he is now known. In this order he
rose step by step until he became prior provincialis and
definitor of his province. Having parly gained a gxeat
reputation for pulpit eloquence., he was appointed court
preacher at Vienna in 1669. There the people flocked in
crowds to hear him, attracted by the force and homeliness
of his language, the grotesqueness of his humour, and the
impartial severity with which he lashed the folUes of all
classes of society. The vices of courtiers and court-life
in particular were exposed with an admirable intrepidity.
In general he spoke as a man of the people in the lan-
guage of the people, the predominating quality of his
style,, which was altogether unique, being an overflowing
and often coarse wit. There are, however, many passages
in his sermons in which he rises to loftier thought, and
uses more refined and dignified language. He died at
Vienna on the 1st December 1709. In his published
writings Abraham-a-Sancta-CSara displayed much the same
qualities as in the pulpit. Perhaps the most favourable
specimen of his style is furnished in Judas der Enschclm.
His works have been several times reproduced in whole
or part, though with many spurious interpolations, within
the last thirty years, and have been very extensively read
by both Protestants and Catholics. A'selection was issued
at Heilbronn in 1845, and a complete edition in 21 vols,
appeared at Passau and Lindau, in 1835-54.
ABRANTES, a town of Portugal, Estrcmadura province,
on the Tagus, about 70 miles N.E. of Lisbon, delightfully
situated on the brow of a hiU, of which the slopes are
covered with olive trees, gardens, and vineyards. It has
considerable trade with Lisbon, particularly in fruit,
com, and oU. The town is strongly fortified, and is
an important military position. At the convention of
Cintra it was surrendered to the British. Junot derived
froin it his title of Duko of Abrantea. Population about
6000.
56
A B R — A B iS
ABRAXT ES, Duke and Ddchzss op. See Jijnot.
AI3KAXA.S, or Aukasajc, a word engraved on certain
fiutique stones, wbich were called on that account Abraxas
stones, and wore used as amulets or charms. The Basili-
dians, a Gnostic sect, attaclied importance to the word, if,
indeed, they did not bring it into use. The letters o£
iPpaidt, in the Greek notation, make up the number 305,
and the liasilidians gave the name to the 3G5 orders of
spirits, which, as they conceived, emanated in succession
from the Supreme Being. These orders were sujipoiied to
occupy as many heavens, each fashioned like, but inferior
to that above it; and the lowest of the heavens was
thought to bo the abode of the spirits who formed the
earth and its inhabitants, and to whom wiis committed
the administration of its affairs. The Abraxas stones,
which are frequently to be met with in the tabincts
of the curious, are of very little value. In addition to
the Tvord Abraxas and other mystical characters, they
Lave often engraved on them cabalistic figures. The com-
monest of these have the head of a fowl, and the arms
and bust of a man, and terminate in the body and tail of
a serpent.
ABRUZZO, originally one of the four provinces of the
continental part of the kingdom of the two Sicilies, after-
ward subdivided into Abruzzo Ulteriore I., Abruzzo Ulte-
riorell., and Abruzzo Citeriorc, which were so named from
their position relative to Naples, and now form three of
the provinces of the kingdom of Italy. The district,
which was the most northerly part of the kingdom of the
two Sicilies, is bounded by the Adriatic on the E, and
by the provinces of Ascoli Piceno on the N., Umbria and
Rome on the W., and Terra di Lavoro, MoUse, and Capi-
tanata on the S. The Abruzzi provinces have an area of
nearly 4900 English square miles, and extend from N. lat.
41°40'to 42°55'. Though presenting to the Adiiatic a coast
of about 80 miles in length, they bave not a single good
port^ This territory is mostly rugged, mountainous, and
covered with extensive forests, but contains also many
fertile and well-watered valleys. The Apennines traverse
its whole extent, running generally from N.W. to S.E., and
here attaining their greatest elevation. Near Aquila is
Monte Corno, the loftiest peak of that chain, called // gran
jSasso d'ltalla, or the great rock of Italy, which rises to the
height of 0S13 feet. Monte Majella and Monte Velino
attain the height of 9500 and 8792 feet respectively.
From the main range of the Apennines a number of smaller
branches run off towards the west. The country is
watered by numerous small rivers, most of which fall into
the Adriatic. They are often suddenly swollen by the
rdns, especially in the spring, and thus cause considerable
damage to the lands through which they pass. The
principal rivers are the Tronto, Treutino, Pescara, and
Sangio. In Abrn2zo Ulteriore II. is lake Celano or Lago
di Fucino, the Lacus Fucinus of the Romons, now reduced
to about one-third of its former extent. The climate varies
with the elevation, but, generally speaking, is temperate
and healthy. Agriculture is but little understood or
attended to, although in many of the lower parts of the
country the land is fertile. The rivers are not e: abanked,
nor is irrigation practised; so that the best of tie land is
frequently flooded during the rainy season, and pirched in
the heat of summer. The principal productions are com,
hemp, flax, almonds, olives, figs, grapes, and chestnuts.
In the neighbourhood of Aquila saffron is extensively
cultivated, although not to such an extent as formerly.
The rearing and tending of sheep is the chief oixupation
of the inhabitants of the highlands; and the wool, which
is of a superior quality, is an important article of com-
merce, while the skins are sent in large quantities to the
Le\-ant. Bears, wolves, and wUd boars inhabit the moun-
tain fastnesses; and in the extensive oak forests nnmerons
herds of swine are fed, the hams of which are in liii;li
ri-pnte. 'i'lie manufactures are very inconsideiaM,, '.:.^'.:;j:
chiefly woollen, Linen, and. silk stuffs, and earthen and
wood wares. Abruzzo 'was of great importance to the
kingdom of Naples, being its chief defence to the north,
and presenting almost insurmountable difliculties to the
ad^Tince of an -enemy. The country is now free of the
daring brigands by whom it was long infested. The
inhabitants are a stout, well-built, brave, and industrious
race. Their houses are generally miserable huts; their
food principally maize, and their drink bad wine. The
railway from Ancona to Brindisi passes through Abruzzo
Ulteriore I. and Abruzzo Citcriore, skirting the coast; and
a line has been projected from Pescara, by Popoli, the Lago
di Fucino, and the valley of the Liris, to join the railway
from Rome to Naples, and thu.s open up the interior of the
country. The line ia open for traffic between Pescara
and Popoli.
Abruzzo Ultebiore I. is the most northerly of the
three provinces, and has an area of 1283 square miles, with
a population in 1871 of 245,684. The western part of .the
province is very mountainous, the highest crest of the Apen-
nines dividing it from Abruzzo Ulteriore II. The valleys
possess a rich soil, well watered by rivulets and brooks in
the winter and spring, but these are generally dried up in
the summer months. Tho streams run mostly into the
Pescara, which botinds the province towards Abruzzo
Citcriore, or into the Tronto, which is the northern
boundary. The city of Teramo is the capital of the
province.
AuKUZZo Ulteeioee n. is an inland district, nearly
covered with mountains of various heights, one of which
is the Gran Sasso. There are no plains ; but among the
mountains are some beautiful and fruitful vallej-s, watered
by the various streams that run through them. None of
the rivers are navigable. The province has an area of 2510
square miles, and in 1871 contained 332,782 inhabitants.
Its chief town is Aquila.
Abruzzo Citeriore lies to the south and east of the
other two pro%'inCes. It is the least hilly of the three, but
the Apennines extend through the south-west part. They,
however, gradually decline in height, and stretch away into
plains of sand and pebbles. The rivers all run to the
Adriatic, and are very low during the summer months.
The soil is not very productive, and agricidture is in a
very backward state ; the inhabitants prefer the chase
and fishing. The province contains 1104 square miies,
with a population of 340.299 in 1871. Its chief town is
ChietL
ABSALOM (o'''=??, father of peace), the third son of
David, king of Israel He was deemed the handsomest
man in the kingdom. His sister Tamar having been
violated by Amnon, David's eldest son, Absalom caused
his scr\'ant3 to murder Amnon at a feast, to which he had
invited all the king's sons. After this deed he fled to the
kingdom of his maternal grandfather, where he remained
three years ; and it was not till two years after his return
that he was fully reinstated in his father's favour. Absalom
seems to have been by this time the eldest surviving son
of David, but he was not the destined heir of his father's
throne. The suspicion of this excited the impulsive
Absalom to rebellion. For a time the tide of public
opinion ran so strong in his favour, that David found it ex-
ing the prompt measures which his sagacious counsellor
Ahithophel advised, Absalom loitered at Jerusalem tQl a
large force was raised against him, and when he took the
field his army was comfiletely routed. The battle was
fought in the forest of Ephraim ; and Absalom, caught in
A B S — A B S
57
Ihe toughs of a tree by the superb hair in which he gloried,
■was run through the body by J oab. The king's grief for
iis wortMess son vented itself in the touching lamentation
— " my son Absalom, my son, my son Absalom 1 woald
God I had died for thee, O Absalom, my son, my son;"
ABSALOJi', Archbishop of Lund, in Denmark, was born
in 1128, near Soroe in Zealand, his family name being
Axel. In 11 -iS he went to study at Paris, where a coUcge
for Danes had been established. He afterwards travelled
extensively in diifercnt countries; and returning to Den-
mark in 1157, was the year after chosen Bishop of Roes-
kilde or Kothschild. Eloquent, learned, endowed with
uncommon physical strength, and possessing the confidence
pf the king, ^V'aldcma^ I., known as the Great, Absalon
held a position of great influence both in the church and
state. In that age V/arlike pursuits were not deemed in-
consistent with the clerical office, and Absalon was a
renowned warrior by sea and land, as well as a zealous
ecclesiastic, his avowed principle being that " both swords,
the spiritual and the temporal, were entrusted to the
clergy." To his exertions as statesman and soldier Wal-
demar was largely indebted for the independence and con-
solidation of his kingdom. In 1177 he was chosen by the
chapter Archbishop of Lund and Primate of the church,
but he declared himself unwUhng to accepi;. the appoint-
ment; and when an attempt was made to install him by
force, he resisted, and appealed to Rome. The Pope de-
cided that the choice of the chapter must be respected,
and commanded Absalon to accept the Primacy on pain of
excommunication. He was consecrated accordingly by the
papal legate Galandius in 1178. He set the Cistercian
monks of Soroe the task of preparing a history of the
country, the most valuable result being the Danish
Chronicle of Saxo Grammaticus, who was secretary to
Absalon and his companion in an expedition against the
iWendish pirates. A tower or castle which the archbishop
caused to be buUt as a defence against these pirates, was
the commencement of the present capital, Copenhagen,
,which from this circumstance is sometimes known in his-
tory as Axelstadt. The archbishop died in 1201, in the
monastery at Soroe, and was buried in the parish church,
where his grave may still be seen.
ABSCESS, in Surgery (from ahscedo, to separate), a
iCoIlection of pus among the tissues of the body, the result
of inflarajnation. Abscesses are divided into acute and
chronic. See Sukqery.
ABSINTHE, a liqueur or aromatised spirit, prepared oy
pounding the leaves and flowering tops of various species
of wormwood, chiefly Artemisia Absinthium, along with
angelica root {Arcliangelica officinalis), sweet flag root
(Acorus Calamus), the leaves of- dittany of Crete (OnV/are«TO
\Dictamnus), star-anise fruit (Illicium anisaium), and other
aroraatics, and macerating these in alcohol. After soaking
for about eight days the compound is distilled, yielding an
emerald-coloured, liquor, to which a proportion of an
essential-oil, usually that of anise, is added. The liqueur
thus prepared constitutes the genuine Exlrait d' Absinthe
of the French ; but much of an inferior quality is made
iWith other herbs and essential oils, while the adulterations
practised in the manufacture of absinthe are very numerous
and deleterious. In the adulterated liqueur the green
'colour is usually produced by turmeric and indigo, but the
.presence of even cupric sulphate (blue vitriol) as a colour-
ing ingi-edient has been frequently detected. ■ In com-
merce two varieties of absinthe are recognised — common
and Swiss absintlie — the latter of which is prepared with
higlily concentrated spirit; and when really of Swiss manu-
facture, is of most trustworthy quality as regards the herbs
used in its preparation, h The chief seat or tho manufa.>
tuio is in the canton of NeufcLatcI ia Switzerland, although.
absinthe distilleries are scattered generally throughout
Switzerland and France. The liqueur is chiefly consumed
in France, but there is also a considerable esport trade to
the United States of America. In addition to the quan-
tity distilled for home consumption in France, the amount
imported from Switzerland in recent years has not been
less than 2,000,000 gallons yearly. The introduction of
this beverage into general use in France is curious. Dur-
ing the Algerian war (1844-47) the soldiers were advised
to mix absinthe with their wine as a febrifuge. On their
return they brought with them the habit of drinking it,
which is ;iow so widely disseminated in French society,
and with such disastrous consequences, that the custom is
justly esteemed a grave national evil. A French physician,
M. Legrand, who has studied the physiological efl'ects of
absinthe drinking, distinguishes two trains of results accord-
ing as the victim indulges in violent excesses of drinking
or only in continuous steady tippUng. In the case of
excessive drinkers there is first the feeUng of exaltation
peculiar to a state of intoxication. The increasing dose
necessary to produce this state quickly deranges the diges-
tive organs, and destroys the appetite. An unappeasable
thirst takes possession of the victim, with giddiness, tingling
in tho oars, and hallucinations of sight and hearing, followed
by a constant mental oppression and anxiety, loss of brain
power, and, eventually, idiocy. The symptoms in the
case of the tippler commence with muscular quiverings and
decrease of physical strength; the hair begins to drop off, the
face assumes a melancholy aspect, and he becomes ema-
ciated, wrinkled, and sallow. Lesion of the brain follows,
horrible dreams and delusions haunt the victim, and gradu-
ally paralysis overtakes him and lands him in his grave.
It has been denied by a French authority, M. Moreau, that
these symptoms are due to wormwood or any of the essen-
tial oils contained in absinthe, and he maintains that the
strong spirit and such adulterations as salts of copper are
suflicient to account for the effects of the liqueur. There
is, however, no doubt that proportionately the consumptioa
of absinthe is much more deleterious to the human frame
than the drinking of brandy or other strong spirits. The
use of absinthe has been prohibited in both the army and
navy of France.
ABSOLUTE (from the Latin absolvere), having the
general meaning of loosened from, or unrestricted, in which
sense it is popularly used to qualify such words as " mon-
archy" or " power," has been variously employed in philo-
sophy. Logicians use it to mark certain classes of njimes.
Thus a term has been called absolute in opposition to attri-
butive, when it signifies something that has or is viewed as
having independent existence ; most commonly, however,
the opposition conveyed is to relative. A relative rams
being taken as one which, over and above the object
which it denotes, implies in its signification the existence
of another object, also deriv^g a denomination from the
same fact, which is the ground of the first name (MUl),
as, e.g., father and son, the non-relative or absolute name
is one that has its meaning for and in itself, as man.
This distinction is a convenient one, although, as has been
observed, it can hardly in perfect strictness be maintained.
Tho so-called r.bsolute name, if used with a meaning, does
always stand in some relation, however variable or in-
definite, and tho meaning varies with tho relation. Thus
man, which is a word of very difl'erciit meanings, as, e.g.,
not woman, not boy, not master, not brute, and so forth,
may be said to have them according to the different
relations in which it admits of being viewed, or, as it has
been otherwise expressed, according to the different notions
whoso '■ universe " it composes, along with its different
correlatives. .. From this point of view there is always one
relaiiQa.ifl_wliich a real thing must Btand, namely, the
L — 8,
58
A B 6 — A B S
relation to its contradictory (03 not man) intbin the
auiverso of being ; tUo correlatives, under less general
notions, being then generally eipreascd positively as con-
traries (woiuan, boy, ni^-ster, brute, and bo forth, for man).
If there is thus no nana or notion that can strictly bo
called absolute, all knowledge may be said to bo relative,
or of the relative. But the knowledge of an absolute has
also been held impossible, on the ground that knowing is
itself a relation between a subject and an object ; what is
known only in relation to a mind cannot be known as
absolute. This doctrine, now commonly spoken of under
the name of the Relativity of Knowledge, may, indeed, be
brought under the former view, in which subject-object
marks the relation of highest philosophical significacce
within the whole universe of things. Keeping, however,
the two views «part, we may say with double force that
of the absolute there is no knowledge, — (1), because, to be
known, a thing must be consciously discriminated from
other things; and (2), because it cau bo known only in
relation with a knowing mind. Notwithstanding, there
have been thinkers from the earliest times, who, in dif-
ferent ways, and more or less explicitly, aUow of no such
restriction upon knowledge, or at least consciousness, but,
on the contrary, starting from a notion, by the latter
among them called the absolute, which includes within it
the opposition of subject and object, pass therefrom to
the explanation of al] the phenomena of natuie and of
mind. In earlier days the Eleatics, Plato, and Plotinus,
in modern times Spinoza, Leibnitz, Fichte, Schelling,
Hegel, and Cousic, all have joined, under whatever dif-
ferent forms, in maintaining this view. Kant, while
denying the absolute or unconditioned as art object of
knowledge, leaves it conceivable, as an idea regulative of
the mind's intellectual .experience. It is against any such
absolute, whether as real or conceivable, that Hamilton
and Mausel have taken gi-ound, the former in his famous
review of Cousin's ])liilosophy, reprinted in his Discussions,
the latter in his Bampton Lectures on 2'he Limits of.
lltligious Thoiujhi, basing their arguments indifferently on
the positions as to the Relativity of Knowledge indicated
above. For absolute in its more strictly metaphysical use,
see Metapuysics. (o. c r.)
ABSOLUTION, a term used in civil and ecclesiastical
law, denotes the act of setting free or acquitting. In a
criminal process it signifies the acquittal of an accused
person on the ground that the evidence has either dis-
])roved or faDed to prove the charge brought against him.
It is now little used except in Scotch law, in the forms
assoilzie and absolvitor. The ecclesiastical usage of the
vord is essenli.ally different from the civil It refers to
sm actually committed, and denotes the setting of a person
free from its guilt, or from its penal consequences, or from
both. It is invariably connected with penitence, and some
form of confession, the Scripture authority, to which the
Uoman Catholics, the Greek Church, and Protestants
equally appeal, being found in John xx. 23, James v. 1 6,
»tc. In the primitive church the injunction of James was
literally obeyed, and confession was made before the
whole congregation, whose presence and concurrence were
reckoned necessary to the validity of the absolution pro-
nounced by the presbjrter. In the 4th century the bishops
began to exercise the power of absolution in their own
right, without recognising the congregations. In conse-
quence of this the practice of private confession (con/essio
iiuncularis) was established, and became more and more
common, unti it was rendered imperative once a year by
a decree of the fourth Lateran Council (1215). A dis-
tinction, indeed, was made for a time between peccata
venudta, which might bo confessed to a layman, and
pcccdtc nwrtaHa. which could only be confessed to a, pnes'c;
but this was ultimately abolished, and the r>oman CanoQ
Law now etands, JS'ec vmdalia nee morlalia poesumus
cnnfiteri taoavifntaliier, nisi tactrdoti. A change in the
form of absolution was almost a logical sequence of tha
change in the nature of the confession. At first the priest
acted ministerially as an intercessory, using the formula
abaoluti^Tiit precativa or cUprecaliia, which consisted of the
words : Dominua absolvat te — iliserealur tut omnipotena
Dcuf et dimittal tibi omnia peccata tva. This is still the
only form in the Greek Church, and it finds a place in the
Roman Catholic service, though it is no longer used in
the act of absolution. The Romish form was altered in
the 13Lh century, and the Council of Trent decreed the
tise of the formula abtolutionis indicativa, where the priest
acts judicially, as himself possessed of the power of bind-
ing and loosing, and says. Ego absolvo te. Where a form
of absolution is used in Protestant Churches, it is simply
declarative, the state being only indicated, and in no sense
or degree assumed to be caused by the declaration.
ABSOIIPTION, in the animal economy, the function
possessed by the absorbent system of vessels of taking up
nutritive and other fluids. See Physiology.
AJBSTEMII, a name formerly given to such persons as
could not partake of the cup of the eucharist on account
of their natural aversion to wine. Calvinists allowed these
to communicate in the species of bread only, touching
the cup with their lip; which was by the Lutherans
deemed a profanation. Among several Protestant sects,
both in Great Britain and America, abstemii on a some-
what different principle have recently appeared. These
are total abstainers, who maintain that the use of stimu-
lants Ls essentially sinful, and allege that the wine used
by Christ and his disciples at the supper was unfermented.
They accordingly communicate in the unfermented "juice
of the grape." The difference of opinion on this point
has led to a good deal of controversy in many congrega-
tions, the solution generally arrived at being to allow both
wine and the pure juice of the grape to be served'al the
communion table.
ABSTRACTION, in Psychology and Tyogic, is a word
used in several distinguishable but closely allied senses.
First, in a comprehensive sense, it is often applied to that
process by which we fix the attention upon one part of
what is present to the mind, to the exclusion of another
part ; abstraction thus conceived being merely the nega-
tive of Attention a( J. v.) In this sense we are able in
thought to abstract one object from another, or an attribute
from an object, or an attribute perceived by one sense
from those perceived by other senses. Even in cases
when thoughts or images have become inseparably
associated, we posssss something of this power of abstract-
ing or turning the attention upon one rather than another.
Secondly, the word is used, with a more special significa-
tion, to describe that concentration of attention upon the
resemblances of a number of objects, which constitutes
classification. And thirdly, not to mention other less
important changes of meaning, the whole process of
generalisation, by which the mind forms the notions
expressed by common terms, is frequently, throagh a
curious transposition , of names, spoken of as abstraction.
Especially when understood in its less comprehensive
connection, the process of abstraction possesses a peculiar
interest. To the psychologist it is interesting, because
there is nothing he is more desirous to understand than
the mode of formation and true nature of what are called
general notions. And fortunately, with regard to the
abstractive process by which these are formed, at least in
its initial stages, there is little disagreement ; since every
one describes it as a procees of comparison, by which the
mind is enabled to consider the objects confusedly pre-
A B S — A B U
59
sented to it in intuition, to recognise and attena exclusiTely
to their points of agreement, and so to classify them in
accordance with their perceived resemblances. Further,
tiiis process is admitted without much dispute to belong
to the discursive or elaborative action of the intellect ;
although, perhaps — should the view of some modern
psychologists be correct, that all intelligence proceeds by
the establishment of relations of likeness and unlikeness
— abstraction will be better conceived as thus related to
intelligence in general and typical of all its processes, than
as the action merely of a special and somewhat indefinite
faculty. No such harmony, however, exists regarding the
nature of the product of abstraction; for that is the subject-
matter of Nominalism and Kealism, which has produced
more controversy, and stimulated to more subtlety of
thought, than any other subject ever debated in philo-
Bophy. The concept or abstract idea has been represented
in a multitude of ways : sometimes as an idea possessing
an objective existence independent of particulars, even
more real and permanent than theirs ; sometimes as an
idea composed of all the-cii-cumstances in which the par-
ticulars agree, and of no others ; again, as the idea of an
individual, retaining its individualising qualities, but with
the accompanying knowledge that these are not the pro-
perties of the class ; and yet again, as the idea of a
miscellaneous assemblage of individuals belonging to a
class. It is still impossible to say that the many-sided
controversy is at an end. The only conclusion generally
admitted seems to be, that there exists between the con-
cept and the particular objects of intuition some very
intimate relation of thought, so that it is necessary, for all
purposes of reasoning, that the general and particular go
hand in hand, that the idea of the class — if such exists
— be capable of being applied, in every completed act of
thought, to the objects comprised within the class.
To the student of ontology, also, abstraction is of
special interest, since, according to many distinguished
thinkers, the recognition of abstraction as a powerful and
universal mental process is to explain all ontology away,
and give the ontologist his eternal quietus. The thorough-
going notain'vlist professes to discover in the mind an
inveterate tendency to abstraction, and a proneness to
ascribe separate existence to abstractions, amply sufficient
to account for all those forms of independent reality which
metaphysics defend, and to exhibit them all in their true
colours as fictitious assumptions. In reply, the ontologist,
strengthened by the instinct of self-preservation, commonly
contends that the analogy between general notions and
metaphysical principles does not hold good, and that the
latter are always more than simple abstraciions or mere
names. Only after abstraction is understood can the
question be settled.
In like manner to logic, whether regarded as tne science
of the form.al laws of thought, or, more widely, as the science
of scientific methods, a true understanding of abstraction
is of the greatest importance. It is important in pure
logic, because, as we have seen, every act of judgment and
reasoning postulates a concept or concepts, and so pre-
supposes abstraction. Abstraction, detenniniflg the possi-
bility alike of reason and speech, creates those notions
that bear common names ; it is indispen.sable to the
formation of classes, great or small; and just according as
it ascends, increasing the extension and diminishing the
intension of classes, the horizon visible to reason and to
)o<nc gradually recedes and widens. And to logic as the
science of the sciences a true doctrine of abstraction is not
less necessai-y ; because the process of extending know-
ledge is, in all its developments, essentially th.; same as
the first rudimentary effort to form a concept and think of
particulars as members of a class ; i " natural law," at
least m its subjective aspect, is invariably an abstraction
made by comparing phenomena — an abstraction under
which phenomena are classed in order to the extension of
knowledge just as under a concept are grouped the par-
ticulars presented in intuition. As proof of this identity
it is found that the 'same diS'erences exist regarding the
objective or subjective nature of the " natural law " as
regarding that of the concept. Some affirm that the law
the facts ; others, that it is never in any sense more than
a mere mental conception, got by observing the facts ;
while there are yet others who maintain it to be sucli a sub-
jective conception, but one corresponding at the same time
to an external relation which is real though unknowable.
ABSURDUM, Eeductio ad, a mode of demonstrating
the truth of a proposition, by showing that its contra-
dictory leads to an absurdity. It is much employed by
EucUd.
VBU, a celebrated mountain oi western India, between
oOOO and 6000 feet in height, situated in 2i° 40' N. lat.,
and 72° 48' E. long., within the RAjputdn4 State of Sirohf.
It is celebrated as the site of the most ancient Jain temples
in India, and attracts pilgrims from all parts of the country.
The Jaius are the modern Indian representatives of the
Buddhists, and profess the ancient theistic doctrines of that
sect, modified by saint worship and incarnations. The
elevations and platforms of the mountain are covered with
elaborately sculptured shrines, temples, and tombs. On
the top of the hill is a smaU round platform containing a
cavern, with a block of granite, bearing the impression of
the feet of Ddta-Bhrigu, an incarnation of Vishnu. This
is the chief great place of pilgrimage for the Jains, Shrawaks,
and Banians. The two principal temples are situated at
Deulwar4, about the middle of the mountain, and five miles
south-west of Guru Sikrd, the highest summit. They are
built of white marble, and are pre-eminent alike for their
beauty and is typical specimens of Jain architecture in
India. The following description is condensed from Mr
Fergusson's History of Architecture, vol. ii. pp. 623 to
625 : — The more modern of the two was built by two
brothers, rich merchants, between the years 1197 and
1247, and for delicacy of carving and minute beauty of
detail stands almost unrivalled, even in this land of patient
and lavish labour. The other was buUt by another
merchant prince, Bimala Shdh, apparently about 1032 a.d.,
and although simpler and bolder in style, is as elaborate as
good taste would allow in a purely architectural object.
It is one of the oldest as well as one of the most complete
examples of Jain architecture known. The principal object
within the temnle is a cell lighted onjj from the door, con-
taining a cross-legged a(3«f:cd figure TSi'thegod ParesnAth.
The portico is composed of forty-'^ight pUlars, the whole
enclosed in an oblong court-yard about 140 feet by 90
feet, surrounded by a double colonnade of smaller pDIars,
forming porticos to a range of fifty-five cells, which enclose
it on all sides, exactly as they do in a Buddhist monastery
(vikdra). In this temple, however, each cell, instead of
being tlie residence of a monk, is occupied by an im.age of
Paresnith, and over the door, or on the jambs of each, are
sculptured scenes from the life of the deity. The whole
interior is magnificently oruameirted. The Emperor Akbar,
by a farmin dated in the mouth of Eabi-ul-Aul, in the
37th year of his reign, corresponding with 1C93, made a.
grant of the hill and temples of Abu, as well as of the
other lulls and places of Jain pilgrimage in the empire, to
Ilarbijai Sur, a celebrated preceptor of the Setimbari sect
of the Jain religion. He also prohibited the slaughter of
animals at these places. The farmdn of this enlightened
monarch declared th.at "it is the rule of the worshipper-
of God to preserve all religions."
GO
A B U — A B U
ABCJ-BEKR {father nf the virgin), v/as originally called
Abd-el-Caaba (servant of t>t^ temple), and received the name
by which ho is known histxjrically in consequonco of the
marriage of his virgin daughter Ayesha to Mohaiumcd. . He
■naa born at Mecca in the year 073 A.D., a Koreishito of
the tribe of Bcun-Taim. Possessed of immense wealth,
■which he liad himself acquired in commerce, and held in
hi"h esteem as a judge, an interpreter of dreams, and a
depositary of the traditions of his race, his early accession
to Islamism was a fact of great importance:^ On his con-
version he assumed the name of Abd-Alk (servant of God).
His own belief in Mohammed and his doctrines was so
thorough as to procure for him the title El Siddik (the
faithful), and his success in gaining converts was corre-
spondingly great. In his personal relationship to the
prophet ho showed the deepest veneration and most un-
swerving devotion. When Mohammed fled from Mecca,
Abu-Bekr was his sole companion, and shared both his
hardships and his triumphs, remaining constantly with
him until the day of his death. During his last illness
the prophet indicated Abu-Bekr as his successor, by desir-
ing him to offer up f)rayer for the people. The choice
was ratified by the chiefs of the army, and ultimately con-
firmed, though All, Mohammed's son-in-law, disputed it,
asserting his own title to the dignity. After a time Ali
submitted, but the difference of opinion as to his claims
gave rise to a controversy which still divides the followers
of the prophet into the rival factions of Sunnites and
Shiites. Abu-Bekr had scarcely assumed his new position
under the title Khalifet-Resul-Allah (successor of the prophet
of God), when he was called to suppress the revolt of the
tribes Hedjaz and Nedjd, of which the fonner rejected
Islamism, and the latter refused to pay tribute. He en-
countered formidable opposition from different quarters,
but in every case he was successful, the severest struggle
bein" that with the impostor Mosailima, who was finally
defeated by Khaled at the battle of Akraba. Abu-Bekr's
zeal for the spread of the new faith was as conspicuous as
that of its founder had been. When the internal disorders
had been repressed and Arabia completely subdued, he
directed his generals to foreign conquest The Irak of
Persia was overcome by Khaled in a single campaign, and
there was also a successful expedition into Syria. After
the hard-won victory over Mosailima, Omar, fearing that
the sayings of the prophet would be entirely forgotten
moved by death, induced Abu-Bekr to see to their preserva-
tion in a written form. The record, when completed, was
deposited with Hafsu, daughter of Omar, and one of the
wives of Mohammed. It was held in great reverence by all
Moslems, though it did not possess canonical authority,
and furnished most of the materials out of which the
Koran, as it now exists, was prepared. When the authori-
tative version was completed, all copies of Hafsu's record
were destroyed, in order to prevent possible disputes and
divisions. Abu-Bekr died on the 23d of August 634,
having reigned as Khalif fully two years. Shortly before
his death, which one tradition ascribes to poison, another
to natural causes, he indicated Omar as his successor, after
the manner Mohammed had observed in his own case.
ABULFAKAGIUS, Geegob Abulfakaj (called also
BaehebEjEUS, from his Jewish parentage), was born at
Malatia, in Armenia, in 1226. His father Aaron was a
physician, and Abulfaragius, after studying under him,
also practised medicine witn great success. His command
of the Arabic, Syriac, and Greek languages, and his know-
ledge of philosophy and theology, gained for him a very
liigh reputation. In 1244 he removed to Antioeh, and
shortly after to Tripoli, where he was consecrated Bishop
of Cuba, when only twenty years of age. He was subse-
quently transferred to the Boe of Aleppo, and was elected
in 1266 Maphrian or Primate of the eastern Ecction of
the Jacobite Uhristians. This dignity he held till his
death, which occurred at Maragha, in Azcrbijan, in 1286.
Abulfaragias wrote a large nimiber of works en various
subjects, but his fame as an author rests chiefly on hia
Hittorji of the World, from the creation to his owii
day. It was written first in Syriac, and then, after a
considerable interval, an abridged version in Arabic
The latter is divided into ten sections, each of which con-
tained the account of a separate dynasty. The historic
value of tne ■won lies entirely in the portions that treat of
eastern nations, especially in those relatujg to the Saracens,
the Tartar Mongols, and the conquests of Genghis Khan.
The other sections are full of mistakes, arising partly no
doubt from the author's comparative ignorance of chissical
languages. A Latin translation of the Arabic abridgement
tion of the original text, with Latin translation, edited, by
no means carefully or accurately, by Bruns and F. W.
Kirsch, appeared at Leipsic in 1788.
ABULFAZL, vizier and historiographer of the great
Mongol emperor, Akbar, was born about the middle of
the 16th century, the precise date being uncertain. His
career as a minister of state, brilliant though it was, would
probably have been by this time forgotten but for the
record he himself has left of it in his celebrated history.
The Akhar Nameh, or Book of Akbar, as Abulfazl's chief
literary work is called, consists of two parts, — the first being
a complete history of Akbar's reign, and the second,
entitled Ayin-i-Akbari, or Institutes of Akbar, being an
account of the religious and political constitution and
administration of the empire. The style is singularly
elegant, and the contents of the second part possess a
unique and lasting interest. An excellent translation of
that part by Mr Francis Gladwin was published in Cal-
cutta, 1783-6. It was reprinted in London very in-
accurately, and copies of the original edition are now
exceedingly rare and correspondingly valuable. Abulfazl
died by the hand of an assassin, while returning from a
mission to the Deccan in 1 002. Some writers say that the
murderer was instigated by the heir-apparent, who had
become jealous of the minister's influence.
ABULFEDA, Ismaf.l ben-Axi, Emad-eddijj, tne. cele-
brated Arabian historian and geographer, bom at Damascus
in the year 672 of the Hegira (1273 a.d.), was directly
descended from Ayub, the father of th() emperor Saladin.
In his boyhood he devoted himself to the study of the
Koran and the sciences, but from his twelfth year he was
almost constantly engaged in military expeditions, chiefly
against the crusaders. In 1285 he was present at the
assault of a stronghold of the Knights of St John, and he
took part in the sieges of Tripoli, Acre, and Roum. In
1298 the princedom of Hamah and other honours, origin-
ally conferred by Saladin upon Omar, passed by inherit-
ance to Abvilfeda; but the succession was violently dis-
puted by his two brothers, and the Court availed itself of
the opportunity to supersede all the three, and to abolish
the principahty. The siiltan Melik-el-Nassir ultimately
(1310) restored the dignity to Abulfeda, with additional
honours, as an acknowledgment of his military services
against the Tartars and Bibars, the sultan's rival He
received an independent sovereignty, with the right of
(victorious prince) conferred upon him. For twenty years,
tiU his death in October 1331, he reigned in tranquillity
and splendour, devoting himself to the duties of govern-
ment and to the composition of the works to which he is
chiefly indebted for his fame. He was a munificent patroa
A B U — A B Y
61
of men of letters, wlio repaired in large numbers to his
court. Abulfeda's chieiE historical work is An Abi-idgane;it
of the History of ihe Human Race, in the form of annals,
extending from the creation of the world to the year 1328.
A. great part of it is compiled from the works of previous
srriters, and it is diflScult to determine accurately what is
the author's and what is not. Up to the time of the birth
of Mohammed, the narrative is very succinct; it becomes
more full and valuable the nearer the historian approaches
his own day. It is the only source of information on
many facts connected w^th the Saracen empire, and alto-
gether is by far the most important Arabi.an history we
now possess. Various translations of parts of it exist,
the earUest being a Latin rendering of the section relating
to the Arabian conquests in Sicily, by Dobelius, Arabic
professor at Palermo, in 1610. This is preserved in
Muratori's Reritm llallcarum Scriptores, vol. i. The his-
tory from the time of Mohammed was published with a
Lr.tin translation by Reiske, under the title A nnalex Mos-
lemici (5 vols., Copenhagen, 1789-94), and a similar
Leipsio in 1831, under the title Ahulfedoe Hisloria Ante-
Islamitica. His Geography is chieily valuable in the his-
torical and descriptive parts relating to the Moslem empire.
From his necessarily imperfect acquaintance with astro-
nomy, his notation of latitude and longitude, though fuller
than that of any geographer who preceded him, can in no
case be depended on, and many of the places whose posi-
tion he gives with the utmost apparent precision cannot
MM. Reinaud and De Slane at Paris in 1840; and Eeinaud
published a French translation, with notes and illustrations,
in 1848. MSS. of both Abulfeda's great works are pre-
served in the Bodleian Library and in the National
Library of France.
Khiva, of the race of Genghis-Khan, who, after abdicating
in favour of his son, employed his leisure in writing a
history of the Mongols and Tartars. He produced a
valuable work, which has been translated into German,
French, and Russian.
ABUNA, the title given to the archbishop or metropoli-
tan of Abyssinia.
ABUSHEHR. See Bushiee.
ABU-SIMBEL, or Ipsambul, the ancient Ahoccis or
Abuncis, a place in Nubia, on the left bank of the Nile,
about DO miles S.W. of Dorr, remarkable for its ancient
Egyptian temples and colossal figures hewn out of the
solid rock. For a description of these see NuDiA.
ABU-TEMAN, one of the most highly esteemed of
Arabian poets, was born at Djacem in the year 1 90 of the
Hegira (806 a.d.) In the little that is told of his life is
is difficult to distinguish between truth and fable. He
seems to have lived in Egypt in his youth, and to have
been engaged in servile employment, but his rare poetic
talent speedOy raised him to a distinguished position at
the court of the caliphs of Bagdad. Arabian historians
assert that a single poem frequently gained for him many
thousand pieces of gold, and the rate at which his con-
temporaries estimated his genius may be understood from
the saying, that " no one could ever die whose name had
been praised in the verses of Abu-Teman." Besides
writing original poetry, he made three collections of select
pieces from the poetry of the East, of the most important
of which, called Hamasa, Sir William Jones speaks highly.
Professor Caa'lyle quoted this collection largely in his Speci-
mens of Arabic Poetry (1796). An edition of the text,
Bonn (1828-51), and a meritorious translation in German
verse by Riickert appeared in 1846. Abu-Teman died
845 A.D.
ABYDOS (1.), in Ancient Geography, a city of Mysia
in Asia Minor, situated on the Hellespont, which is hert
scarcely a mile broad. It probably was originally a
Thracian town, but was afterwards colonised by Milesians.
Nearly opposite, on the European side of the Hellespont,
stood Sestos; and it was here that Xerxes crossed the
strait on his celebrated bridge of boats when he invaded
Greece. Abydos was celebrated for the vigorous resistance
it made when besieged by Philip 11. of Macedon; and is
famed in story for the loves of Hero and Lcander. The
old castle of the Daidanelles, built by the Turks, lies a
little southward of Sestos and Abydos.
ABYDOS (2.), in Ancient Geography, a town of Upper
Egypt, a little to the west of the Nile, between Ptolemais
and DiospoUs Parva, famous for the palace of Memnon and
the temple of Osiris. Remains of these two edifices are
still in existence. In the temple of Osiris Mr Bankeg
discovered in 1818 the tablet of Abydos, contaiiung a
double series of twenty-six shields of the predecessors of
Barneses the Great. This tablet is now deposited in the
British Museum,
ABYSSINIA
ABYSSINIA is an extensive country of Eastern Africa,
the limits of which are not well defined, and authorities
are by no means agreed respecting them. It may, however,
be regarded as lying between 7° 30 and 15° 40' N. lat., and
35° and 40° 30' E. long., having, N. and N.W., Nubia ;E.,
the territory of the Danakils ; S. , the country of the Gallas^
md W., the regions of the Upper Nile.' It has an area of
* It is usual to include in Abyssinia tlie flat country wliicli lies betTv-cen
it and the Red Sea, and to regard the latter as forming its boundary on
the east. This, however, is not stiictl/ correct. Ahysoinia proper com-
prises only the mouritainous portion of this territorj', the low lying por-
tion being inhabited by distinct and hostile tribes, and claimed by the
Viceroy of Egypt as part of his dominions. The low country is very
unhealthy, the soil dry and arid, and with few exceptions uncultivated,
whereas the hi;jhlands are generally salubrious, well v/atered, and in
many parta very fertile. This arid track of country is only a few miles
broad at Massowah, in the north, but widens out to 200 or 300 miles at
Tajurrah, in the south. It is, in a groat mea-suro, ov/inf; to Aby^^sinia
being thus cut off from intorcourso with the civilised world by this in-
bospitable region, which has for three centuries bcou in the hnnda of
enemies, that it is at present so .for sunk in iguorunce and barbarism.
about 200,000 square miles, and a population of frc'in
3,000,000 to 4,000,000.
The name Abyssinia, or more properly Habessinia, is
derived from the Arabic word Habesch, which signifies
mixture or confusion, and was applied to this countiy by
the Arabs on account of the mixed character of the people.
This was subsequently Latinised by the Portuguese intc
Abojssia and Abassinos, and hence the present name. The
Abyssinians call themselves Iliopyavan, and their country
Iliopia, or Manghesta Itiopia, the kingdom of Ethiopia.
The country of Abyssinia rises rather abruptly from the
low arid' district on the borders of the Bed Sea in lofty
ranges of mountains, and slopes away more gradually to
the westward, where the tributaries of the Nile have formed
numerous deep valleys. It consists for the most part of
extensive and elevated table-land.s, with mountain ranges
e.xtcnding in dififerent directions, and intersected by numerous
valleys. The table-lands are generr.lly from 6000 to POOO
feet above the level of the sea, but in the sou^i there ar»
S2
ABYSSINIA
some of considerable extent, which attain a height of more
than 10,000 feet. The mountains in various parts of the
country rise to 12.000 and 13,000 feet above the sea, and
some of the peaks of Samen are said to reach to 15,000
feet, and to bo always covered with snow. The average
height of the range which divides the streams flowing to
th2 east from tjosa that flow westward is about 8000 feet,
rising to 10,00o or 11,000 in the south, and sinking in the
north. The whole country presents the appearance of
having been broken np and tossed about in a remarkable
manner, the mountains assuming wild and fantastic forms,
•with sides frequently abrupt and precipitous, and only
accessible by very difficult pas-ses. The Samen range of
mountains are the highest in Abyssinia, and together with
the Lamalmon and Lasta mountains form a long but not
continuous chain, running from north to south.
Sketch Chart of Abyssinia.
The principal rivers of Abyssinia are tributaries of the
Nile. The western portion of the country may be divided
into three regions, drained respectively by the Mareb, the
Atbara, and the AbaL The most northern of these rivers
ia the Mareb, which rises in the mountains of Taranta,
flows first south, then west, and afterwards turns to the
north, where it is at length, after a course of upwards of
500 milo!, lost in the sand, but in the rainy season it falls
into the Atbara. The Atbara, or Takazza, rises in the
mountains of Lasta, and flowing first north, then west, and
again turning to the north, at length falls into tho Nile,
after a coui'se of about 800 miles. The Abai, Bahr-el-Azrek
or Blue River, the eastern branch of the Nile, and considered
by Bruce to bo tho main stream of that river, rises from
two mountains near Geesh, in lat 10° 59' 25' N., long.
36° 55' 30" E., about 10,000 feet above the level of the
sea. It flows first north to the Lake of Dembea or Tzana,
then takes a long semicircular sweep round the province of
Godjam, and afterwards flows northward to about the 10th
degree of N. lat., where it unites with the Bahr-el-Abiad,
which has now been ascertained to be the true Nil^i The
Hawash, the principal river of eastern Abyssinia, rises about
lat. 9° 30' N., long. 38° E.and, flowing in a north-easterly
direction towards the Red Sea, is lost in Lake Aussa, laJj
ir25'N.,long. 'tr40'E. The principal hke of Abyssinia
is the Dembea, which lies between 11° 30' and 12° SC N.
lat., and 37° and 37° 35' E. long., being about 60 miles in
length by 40 in width, and containing a number of small
islands. It is fed by numerous smaU streams. The lake
of Ashangi, in kt. 12° 35' N., long. 39° 40' R, is about 4
miles long by 3 broad, and upwards of 8000 feet above tho
sea.
The fundamental rocks of Tigr£, and probably of all
Abyssinia, are metamorphic. They compose the mass of
the table-land, and while they occupy no inconsiderable
portion of its surface, they are exposed, in Tigr6 at least, in
every deep valley. The metamorphics vary greatly in
mineral character, "every intermediate grade being found
between the most coarsely crystallino granite and a slaty
rock so littlo altered that tho lines of the original bedding
are still apparent Perhaps the most prevalent form of
rock is a rather finely crystalline gnsies. Hornblende-schist
and mica-schist are met with, but neither of tho minerals
from which thoy are named appears to be so abundant as
in some metamorphic tracts. On the other hand, a compact
felspathic rock, approaching febite in composition, is pre-
valent in places, as in the Suru defile, between Komayli
and Senaf6." There are a few exceptions, but as a general
nilo it may bo asserted that in tho neighbourhood of the
route followed by the British army, so much of the country
as is more than 8000 feet above the sea consists of bedded
traps, and this is probably the case in general over Abys-
sinia. " Between the traps and tho metamorphica a
series of sandstones and limestones intervene, one group of
the former underlying the latter. The limestone aione is
fossiHferous, and is of Jurassic age." " On the route to
Magdala volcanic rocks were first met with at Senaf^ where
several liilla consist of trachyte, passing into claystone and
basalt Trap hills, chiefly of trachyte, are dotted over the
country to the southward as far as Fokada, a distance of
nearly 30 miles. Here a great range of bedded traps com-
mences, and extends for about 25 miles to the south, pass-
ing to the west of Adigerat" At Meshek, two marches
south of Antalo, " the route entered high 'ranges entirely
composed of trap, and thence no other rocks were seen as
far as Magdala." " The trappean rocks belong to two dis-
tinct and unconformable groups. The lower of these is
much inclined, while the higher rests on its upturned and
denuded edges." Denudation has evidently been going on
to a great extent in this country. One of its most striking
features are the deep ravines which have been worked out
by the action of the streams, sometimes to the depth of
3000 or 4000 feet " How ranch of the Abyssinian high-
lands has been removed by these great torrents, and spread
as an alluvial deposit over the basin of the Nile 1" "Probably
over the whole of northern Abyssinia there existed at least
4000 feet of bedded traps, of which now only a few vestiges
remain." — W. T. Blanford,
Abyssinia is said to enjoy "probably as saiuorious a
climate as any country on the face of the globe." —
Parh/ru. The heat is by no means oppressive, a fine
light air counteracting the power of the sun ; and during
the rainy season, the sky being cloudy, the weather is
always agreeable and cool, while the rain itself is not very
severe. In certain of the low valleys, however, malarious
influences prevail before and after the rainy season, and
bring on dangerous fevers. On the higher parts the cold
is sometimes intense, partictilarly at night The natural
division of the seasons is into a cold, a hot, and a rainy
season. The cold season may be said to extend from
October to February, the hot from the beginning of March
to the middle of June, and the wet or monsoon period from
this time to the end of September. The rainy season is of
importance, not only in equalising the temperature, increasing
ABYSSIFIA
63
tne fertility, and keeping up fhe water supply ol the country,
but, as Sir S. Baker lias shown, it plays a most important
part in the annuo! overflow of the Nile.
On the aumraits and slopes of the highest mountains
the vegetation is of a thoroughly temperate and even
English character ; the plateaux have a flora of the same
character; while on the lower slopes ^f the hills and in the
ravines occur many trees and shrubs of wanner climes.
"The general appearance of the plateaux and plains is that
of a comparatively bare country, with trees and bushes
t'ninly scattered over it, and clumps and groves only occur-
ring round villages and churches. But the glens and ravines
in the plateau sides, each with its little bright spring, are
often thickly wooded, and offer a delicious contrast to the
open country." — Mark/uxm.. This refers more particularly
to the northern portion oi the country, that drained by the
Mareb ; the central and southern parts are much more fertile
and productive. Here the fertihty is so great that in some
parts three crops are raised annually. Agricultui'e receives
considerable attention, and large quantities of maize, wheat,
barley, peas, beans, &c., are grown. Very ey+ensively
cultivated is tef {Poa ahyssinica), a herbaceous plant with
grains not larger than the head of a pin, of which is made
the bread in general use throughout the country. The low
grounds produce also a kind of com called tocussa, of
the lower classes. CoQ'ee grows wild on the western
mountains, and the vine and sugar-cane are cultivated in
favourable localities. Cotton is also grown to a consider-
able extent. Among the fruit-trees are the date, orange,
lemon, pomegranate, and banana. Myrrh, balsam, and
various kinds of valuable medicinal plants are common.
Most of the domestic animals of Europe are fouud here.
The cattle are in general small, and the oxen belong to the
humped race. The famous Galla oxen have horns some-
times four feet long. The sheep belong to the short and
fat-tailed race, and are covered with wooL Goats are very
common, and have sometimes honis two feet in lengtli.
IMie horses are strong and active. Of wild animals the
t-.potted hy^na is among the most numerous, as well as the
fiercest and most destructive, not only roaming in immense
numbers over the country, but fi-equently entering the
towns, and oven the houses of the inhabitants. The
elephant and rhinoceros are numerous in the low grounds.
The Abyssinian rhinoceros has two horns ; its skin, which
has no folds, is used for shields, and for lining diinking
vessels, being regarded as an antidote to poison. Crocodiles
and hippopotami are plentiful in the rivers ; lions, panthers,
and leopards are seen occasionally, and buffaloes frequently.
Among other animals may be mentioned as common various
species of antelopes, wild swine, monkeys, hare" oiuirrels,
several species of hyrax, jackals, <5ic.
The birds of Abyssinia are very numerous, ana many of
them remarkable for the beauty of their plrmage. Great
numbers of eagles, vultures, hawks, and other birds of prey
are met with; and partridges, snipes, pigeon's, parrots,
thrushes, and swallows are very plentiful Among insects
the most numerous and useful is the bee, honey eveiywher^
constituting an important part of the food of the inhabi-
tants, and several of the provinces paying a large proportion
of theii- tribute in this article. Of an opposite class is the
locust, the ravages of which here, as in other parts of
Northern Africa, are terrible. Serpents are not numerous,
but several species are poisonous.
The inhabitants of Abyssinia form a number of different
tribes, and evidently belong to several distinct races. The
majority are of the Caucasian race, and are in general well-
formed and handsome, with straight and regular features,
lively eyes, hair long and straight or somewhat curled, and
colour dark olive, approaching to Uack. Ruppoll regards
thera as identical in teatures with the Bedouin Arabs. The
tribes inhabiting Tigre, Amhara, Agow, kc, belong to this
raca^: The Galla race, who came originally from the south,
have now overrun the greater part of the country, consti-
tuting a large portion of the soldiery, and, indeed, there are
few of the chiefs who have not an intermixture of Galla
blood in their veins. They ate fierce and turbulent ijj
character, and addicted jx) cruelty. Many of them are stOl
idolaters, but most of them have now adopted the Moham-
medan faith, and not a few of them the Christianity of the
Abyssinians. They are genei-ally largo and well-built, of a
brown complexion; with regular features, small deeply-sunk
but very bright eyes, and long black hru'r. A race of Jews,
kn'own by the name of Falashas, inhabit the district of
Samen. They affirm that their forefathers came into the
country in the days of Rehoboam, but it seems more
probable that they ai-rivcd about the time of the destruction
of Jerusalem. From the 10th century they enjoyed theii
own constitutional rights, and were subject to their own
kings, who, they pretend, were descended from King David,
until the year 1800, when the royal race became extinct,
and they then became subject to Tigri.
The prevailing religion of Abyssinia is a very corrupted
form of Chi-istianity. This is professed by the majority of
the people, as well as by the reigning princes of the different
states. There are also scattered over the country many
Mohammedans, and some Falashas or Jews. Christianity
was introduced into this country about the year S.'JO, but
since that time it has been so corrupted by errors of various
kinds as to have become Uttle more than a dead formahty
mixed up with much superstition and Judaism. Feasts
and fast-days are very frequent, and baptism and the Lord's
supper are dispensed after the manner of the Greek Church.
The children are circumcised, and the Mosaic command-
ments with respect to food and purification are observed.
The eating of animals which do not chew the cud and which
have not cloven hoofs is prohibited. The ecclesiastical body
is very numerous, consisting of priests, of various kinds,
with monks and nuns, and is looked upon with great awe
and reverence. If a priest be married previous to his
ordination, he is allowed to remain so; but no one can
marry after having entered the priesthood. The primate
or chief bishop is called Abuna {i.e., our father), and is
nominated by the patriarch of Cairo, whom they acknow-
ledge as their spiritual father. The churches are rude
edifices, chiefly of a circular form, with thatched roofs, the
interior being divided into three compartments, — an outei
one for the laity, one within for the priests, and in the
centre the Holy of Holies, exactly after the manner of a
Jewish temple. The worship consists merely in reading
passages of Scripture and dispensing the Lord's supper,
without any preaching. Like the Greek Church, they have
no images of any kind in their places of worship, but paint-
ings of the saints are very common — their faces always in
full, whatever may be the position of their bodies. They
have iimumerable saints, but above aU is the Virgin, whom
they regard as queen of heaven and earth, and the great
intercessor for the sins of mankind. Their reverence for a
saint is often greater than for the Almighty, and a man
who would not hesitate to invoke the name of his Maker in
witness to a falsehood may decline so to use the nam.e of
St Michael or St George. Legends of saints and works of
religious controversy form almost their entire hterature.
" At present," says Bishop Gobat, " the Christians of
Abyssinia are divided into three parties, so inimicaJ to each
other that they curse one another, and will no longer par-
take of the sacrament together. It is one single point of
theology that disunites them — the imceasing dispute con-
cerning the unction of Jesus Christ."
In manners the Abyi>siuians are rude and barbaroU^
t)4
ABYSSINIA
Engaged as thcj are in coii'inual wars, ana accustomed
to bloodshed, human life is little regarded among them.
Muraera and executions are fi-equent, and yet cruelty is
said not to be a marked feature of their character ; -and in
war they seldom kill their prisoners. When one is con-
victed of murder, he is handed over to the relatives of the
deceased, who may either pit him to death or accept a
ransom. When the murdered person has no relatives, the
priests take upon themselves the office of avengers. The
Abyssinians are irritable, but easily appeased ; and are a
gay people, fond of festive indulgences. On every festive
occasion, as a saint's day, birth, marriage, ic., it is
customary for a rich man to collect his friends and neigh-
bours, and kill a cow and one or two sheep. The principal
parts of the cow are eaten raw while yet warm and quiver-
ing, the remainder being cut into smaU pieces, and cooked
with the favourite sauce of butter and red peppdr paste.
The raw meat in this way is considered to be very superior
in taste and much tenderer than when cold. "I can
readily believe," says Mr Parkyns," that raw meat would be
preferred to cooked meat by a man who from childhood
had been accustomed to it." The statement by Bruce
respecting the cutting of steaks from a hve cow has fre-
quently been called in question, but there can be no doubt
that Bruce actually saw what he narrates, though it would
appear to have been a very exceptional case. Mr Parkyns
was told by a soldier, " that, such a practice v/as not un-
common among the Gallas, and even occasionally occurred
among themselves, when, as in the case Bruce relates, a cow
had been stolen or taken in foray." The principal drinks
are mese, a kind of mead, and bousa, a soit of beer made
from fermented cakes. Their dre?s consists of a large
folding mantle and clcse-fitting drawers ; and their houses
are very rude structures of a conical form, covered with
thatch. Marriage is a very .slight connection among them,
dissolvable at any time by either of the parties ; and poly-
gamy is by no means imcommon. Hence there is httle
family affection, and what exists is only among childreu of
the same father and mother. Children of the .'■,ame father,
but of different mothers, are said to be " alwavs enemies to
each other." — Gohat.
Abyssinia is one of the most ancient monaroiucs in tne
world, and has been governed from time immemorial by an
emperor. For many years, however, until the accession of
the late Emperor Theodore, he had been a mere puppet in
the hands of orte or other of his chiefs. Each chief is
entire master of all soiu:ces of revenue xvithin his territory,
and has practically full power of life and death. His sub-
jection consists in an obhgaticn to, send from time to time
presents to his superior, and to follow him to war with as
large a force as he can muster. For several generations
the emperor had been little better than a prisoner in his
palace at Gondar, his sole revenue consisting of a small
stipend and the tolls of the weekly markets of that city,
the Teal power being in the hands of the ras or vizier of
the empire, who was always the most powerful chief for the
time. If at any time a chief " has found himself strong
enough to march upon the capital, he has done so, placed
upon the throne another puppet emperor, and been by him
appointed ras or vizier, till a rival stronger than himself
could turn him out and take Ms place." — Dr Belce.
The three principal provinces of Abyssinia ar£ Tigr^ in
the north, Amhara (in which Gondar the capital is situated)
in the centre, and Shoa in the south. The governors of
these have all at different times assumed the title of Kas.
Three other provinces of some importance are Lasta and
Waag, whose capital is Sokota; Godjam, to the south of
Lake Dembea ; and Kivara, to the west of that lake, the
birth-place of tha Emperor Theodore The two provinces
of Tigre and Shoa have generally beeu m a state of rebellion
from or acknowledged independence of the central power at
Gondar. The geographical position of Tigr^ enhances ita
political importance, as it lies between Gondar and the seai
at Massowah, and thus holds as it were the gate of the
capital The province of Shoa is almost separated from
that of Amhara.by the Wolla Gallaa, a Mohammedan tribe,
and for a long time the former had been virtually indepen-
dent, and governed by a hereditary line of princes, to one
of whom the Indian government sent a SDCcial embassy
under Major Harris in 1841
The principal towns arc Gondar in Amhara, the lormer
capital of the kingdom, and containing about 7000 inhabit-
ants, and Debra Tabor in Amhara, formerly a email village,
but which rose to be a place of considwable ei^e in conse-
quence of the Emperor Theodore having fixed upon it as
his residence, and near it was Gaflat, v^-here the European
workmen resided. It was burned by the oinperor v.hen be
set out on his fatal march to Magdala. Adowa is the
capital of Tigre, and the second city in the empire, having
about 6000 inhabitants. Antalo \s also one of the principal
towns of Tigr4, and the capital of Enderta. Near Antalo
is CheUcut. Sokota, the capital of Lasta Waag, is a town
of con.siderable size. The capital of Shoa is Ankobar, and
near it is Angolala, also a place of considerable size. The
The language of the religion and literature of the country
is the Geez, which belongs to the Ethiopic class of languages,
and is the ancient language of Tigr6; of this the modem
Tigr(\$ is a dialect. The Amharic, the language of Amhara,
is that of the court, the army, and the merchants, and is
that too which travellers who penetrate beyond Tigr6 have
ordinarily occasion to usa But the Agow in its various
dialects is the language of the people in some provinces
almost exclusively, and in others, where it has been super-
seded by the language of the dominant race, it still exists
among the lowest classes. This last is behoved to be the
original language of. the people; and from the afEnity of the
Geez, Amharic, ~ and cognate dialects, to the Arabic, it
seems probable that they were introduced by conquerors ot
settlers from the opposite shores of the Red Sea. The
Gallas, who have overrun a great part of Abyssinia, have
introduced their own language into various parts of the
country, but in many cases they have adopted the language
of the people among whom they have come. The Uterature
of Abyssinia is very poor, and contains nothing of much
value. During the late war the hbraries in connection
■\rith the religious communities were found to contain only
modern works of little interest On the capture of Magdala,
a large number of MSS. were found there, which had bee u
brought by Theodore from Gondar and other parts. Of
thess 359 were brought home for examination, and are
now deposited in the British Museum. The oldest among
them belong to the 15th and 16th centuries, but the great
bulk of them are of the 17th and 18th, and some are of
the present century. They are mostly copies of the Holy
Scriptures, canonical and apocryphal, including the Book.of
Enoch, praj'er and hymn books, missals, hvea of saints, and
translations of various of the Greek fathers.
The trade and manufactures of Abyssinia are insignificant,
the people being chiefly engaged in agriculture and pastoral
pursuits. Cotton cloths, the universal dress of the country,
aie made in large quantities. The preparation of leather
and parchment is also carried on to some extent, and manu-
factures of iron and brass. "The Abyssinians are, I
think," says Mr Markham, " capable of civihsation. Their
agriculture is good, their manufactures are not to be
despised ; but the combined effects of- isolation, Galla
inroads, and internal anarchy, have thrown them back for
centuries." The foreign trade of Abyssinia is carried on
entirely through Massowah. Its principal imports are lead.
ABYSSIi^lA
65
tin, copper, silk, gunpowder, glass wares, Persian carpcU,
and coloured cloths. The chief exports are gold, ivory,
ilaves, coifee, butter, honey, and wax.
Abpsinia, or at least the northern portion of it, was
included in the ancient kingdom of Ethiopia. The connec-
tion between Egypt and Ethiopia was in early times very
intimate, and occasionally the two countries were under
the same ruler, so that the arts and civilisation of the one
naturally found their way into the other. In early times,
too, the Hebrews had commercial intercourse with the
Ethiopians ; and according to the Abyssinians, the Queen
of Sheba^ who visited Solomon, was a monarch of their
countrj-, and from her son MenOek the kings of Abyssinia
are descended. Diuing the -captivity many of the Jews
settled here, and brought with them a knowledge of the
Jewish religion. Under the Ptolemies, the arts as weU as
the enterprise of the Greeks entered Ethiopia, and led to
the establishment of Greek colonies. A Greek inscription
at Adulis, no longer extant, but copied by Cosmos, and
preserved in his Topographia Chj-utiana, records that
Ptolemy Euergetes, the third of the Greek dynasty in Egypt,
invaded the countries on both sides of the Red Sea, and,
having reduced most of the provinces of Tigr4 to subjection,
returned to the port of Adulis, and there offered sacrifices
to Jupiter, Mars, and Neptune. Another inscription, not
80 ancient, found at Axum, and copied by Salt and others,
states that Aeizanas, king of the Axomites, the Home-
rites, ic, conquered the nation of the Bogos, and returned
thanks to his father, the god Mars, for his victory. The
ancient kingdom of Auxume flourished in the first or
second century of our era, and was at one time nearly
coextensive with the modem Abyssinia. The capital
Auxume and the seaport Adulis were then the chief
centres of the trade with the interior of Africa in gold ^ust,
ivory, leather, aromatlcs, &c. At Axum, the site of the
ancient capital, many vestiges of its former greatness still
exist ; and the ruins of Adulis, which was once a seaport
on the Bay of Anncsley, are now about 4 miles from the
shore. Chriitianity was introduced into the country by
Frumentius, who was consecrated first bishop of Abyssinia
by St Athanasius of Alexandria about A.D. 330. Subse-
quently the monastic system was introduced, and between
470 and 480 a great company of monks appear to have
entered and established themselves in the country. Since
that time Monachiism has been a power among the people,
and not without its infiuence on the course of events. In
522 the king of the Homerites, en the opposite coast of
the Bed Sea, having persecuted the Christians, the Emperor
Justinian requested the king of Abyssinia, Caleb or
Elesbaan, to avenge their cause. He accordingly collected
an army, crossed over into Arabia, and conquered Yemen,
which remained subject to Abyssinia for 67 years. This was
the most flourishing period in the annals of the countiy. The
Ethiopians possessed tie richest part of Arabia, carried on a
large trade, which extended as far as India and Ceylon, and
were in constant communication with the Greek empire.
Their expulsion from Arabia, followed by the conquest of
Egypt by the Mohammedans in the middle of the 7th
century, changed this state of afi'airs, and the continued ad-
vances of the followers of the Prophet at length cut them
off from almost eveiy meauB of communication with the
civihsed world ; so that, as Gibbon says, " encompassed by
the enemies of their religion, the Ethiopians slept for near a
thousand years, forgetful of the world by whom they were
forgotten." About A-d. 9G0, a Jewish princess, Judith,
conceived the bloody design of murdering all the members
of the royal family, and of establishing herself in their stead.
During the execution of this project, the infant king was
carried off by some faithful adherents, and conveyed to Shoa,
where his authority was acknowledged, while Judith reigned
for 40 years over the rest of the kingdom, and transmitted
the crown to her descendants. In 1268 the kingdom waa
restored to the royal house in the person of Icon Imlac.
Towards the close of the 15lh century the Portugueso
missions into Abyssinia commenced. A belief had long
prevailed in Europe of the existence of a Christian kingdom
in the far oast, whoso monarch was known as Prester John,
and various expeditions had been sent in quest of it.
Among others who had engaged in this search was Pedrd
de Covilham, who arrived in Abyssinia in 1490, and,
believing that he had at length reached the far-famed king-
dom, presented to the Negus, or emperor of the country, a
letter from his master the king of Portugal, addressed to
Prester John. Covilham remained in the country, but in
1507 an Armenian named Matthew was sent by the Negus
to the king of Portugal to request his aid against the Turks.
In 1520 a Portuguese fleet, with Matthew on board, entered
the Red Sea in compliance with this request, and an
embassy from the fleet visited the country of the Negus,
and remained there for about sis years. One of this
embassy was Father Alvarez, from whom we have tho
earliest and not the least interesting account of the country.
Between 1528 and 1540 armies of Mohammedans, under the
renowned general Mohammed Gragn, entered Abyssinia from
the low country, and overran the kingdom, obliging the
emperor to take refuge in the mountain fastnesses. In this
extremity recourse was again had to the Portuguese, and
Bermudei, who had remained in the country after the
departure of the embassy, was ordained successor to the
Abuna, and sent on this niission. In consequence a
Portuguese fleet, under the command of Stephen de Gama,
was sent from India and arrived at Massowah. A force
of 450 musqueteers, under the command of Christopher
de Gama, younger brother of the admiral, niarclied into
the interior, and being joined by native troops were at first
successful against the Turks, but were subsequently defeated,
and their commander taken prisoner and put to death.
Soon afterwards, however, Mohammed Gragn was shot in
an engagement, and his forces totally routed. After this,
quarrels arose between the Negus and the Catholic primate
Bermudez, who wished the former publicly to profess liim-
self a convert to Rome. This the Negus refused to do,
and at length Bermudez was obliged to make his way out of
the countiy. The Jesuits who had accompanied or followed
Bermudez into Abyssinia, and fixed their head-quarters
at Fremona, were oppressed and neglected, but not actually
expelled. In the beginning of the following century Father
Paez arrived at Fremona, a man of great tact and judgment,
who soon rose into high favour at court, and gained over
the emperor to his faith. He directed the erection of
churches, palaces, and bridges in different parts of the
country, and carried out many useful works. His successor
Mendez was a man of much less conciliatory manners, and the
feelings of the people became more strongly excited against
the intruders, till at length, on the death of the Negus, and
the accession of his son Facilidas in 1633, they were all
sent out of the country, after having had a footing there
for nearly a centuiy and a half. The French physician
Poncet, who went there in 1698, was the only European
that afterwards visited the country before Bruce in 1769.
It was about the middle of the 16th centui-y that the
Oalla tribes first entered Abyssinia from tho south; and
notwithstanding frequent efforts to dislodge them, they
gradually extended and strengthened their positions till
they had overrun the greater part of the cu jntry. The power
of the emperor was thus weakened, independent chiefs set
themselves up in different parts, until at length he became
little better than a puppet in the hands of the most power-
ful of his chiefs. In 1805 the country was visited bv
Lord Valentia and Mr Salt, and again by Salt in I81Q. In
I o
06
ABYSSINIA
1 620 >Ie.=sro Gobat and Kuglcr were sent oul as missionanes
by the Church Missionary Society, and were well received
by tbo Raa of Tigri. ilr Kuglcr died soon afte- his
arrival, and his place was subsequently supplied by Mr
licnberg, who was followed by Messrs Ulumhardt and Krapf.
In 1830 Mr Gobat proceeded to Gondar, where he also
met with a favourable reception. In 1833 he returned to
Europe, and published a journal of his residence here. In
I ho following year ho went back to TigrC', but in 1836 ho
was compelled to le^ve from ill health. In 1838 other
missionaries were obliged to leave the country, owing to
the opposition of the native priests. Messrs Isenbcrg and
Krapf went south, and established themselves at SLoa.
The former soon after returned to Engjand, and Mr Krapf
remained in Shoa tiU March 1812. Dr Riippcl,tho German
naturalist, Tisitod the country in 1831, and remained
nearly two years. MJI. Combes and Tamiaier arrived at
Massowah iu 1835, and visited districts- which had not been
traversed by Europeans since the time of the Portuguese.
In 1839 the French Government sent out a scientific com-
mission under M. Lefebvre. Its labours extended over five
•/ears, and have thrown great light on the condition and
productions of the country. In 1841 a political mission
was sent by the Governor-General of India to Shoa, under
the direction of Major Harris, who subsequently published
an account cf hia travels. One who has done much to ex-
tend our geographical knowledge of this country is Dr Beke,
who was there from 1840 to 1843. Mr Mansfield Parkyus
was there from 1843 to 1840, and has written the most
interesting boolc on the counti-y since the time of Bruce.
Bishop Gobat having conceived the idea of sending lay
mi-ssionaries into the country, who would engage in secular
occupations as well as carrj' on missionary work, Dr Krapf
and Mr Flad arrived in 1855 as pioneers of that mission.
Six came out at first, and they were subsequently joined by
others Their work, however, was moie valuable to Theodore
than their preaching, so that he employed them as work-
men to himself, and established them at Gaffat, near his
capital. Mi- Stern arrived in Abyssinia in 1860, 'but re-
turned to Europe, and came back in 1863, accompanied by
Mr and Mrs Rosenthal
Lij Kassa, v/ho came subsequently to be known as the
Emperor Theodore, was born in Kuara, a western province
bf Abyssinia, about the year 1818. His father was of noble
family, and hi3 uncle was governor of the provinces of
Dcmbca, Kuara, and Chelga. He w.as educated in a con-
vent, but, preferring a wandering life, he became leader of
t, band of malcontents. On the death of his uncle he was
made governor of Kuara, but, not satisfied with this, he
seized upon Dembea, and having defeated several generals
sent against him, peace w.is restored on his receiving
Tavavitch, daughter of Ras Ali, in marriage. This lady is
Slid to have been his good genius and counsellor, and during
her life his conduct was most exemplar}-. He next turned
his arms against the Turks, but was defeated ; and the mother
of R.13 Ali having insulted him in his fallen condition, he
proclaimed his independence. The troops sent against hira
were successively defeated, and eventually the whole of the
possessions of Ras Ali fell into his hands He next de-
feated the chief of Godjam, and then turned his arms
against the governor of Tigrc, whom he totally defeated in
Februarj- 18.55. In March of the same year he took the
title of Theodore III., and caused himself to be crowned
king of Ethiopia by the Abuna. Theodore was now in the
zenith of his career. He is described, as being generous
to excess, free from cupidity, merciful to his vanquished
enemies, and strictly continent, but subject to violent bursts
oi anger, and possessed of unyielding pride and fanatical
religious zeal, i He was also a man of education and inteUi-
i^cnce, superior to those aniong whom he lived, with natural
talenta for governing, and gaining the esteem of others.
He had further a noble bearing and majestic walk, a frame
capable of enduring any amount of fa'igue, and is said to
have been " the best shot, the best spearman, the best
runner, and the best horseman in Abyssinia." Had he
contented himself with what he now possessed, the sove-
reignty of Amhara and Tigr^, he might have maintained hia
position ; but he was led to exhaust his strength against
the Gallas, which was probably one of the chief causes of
his ruin. He obtained several victories over that people,
ravaged Jheir country, took possession of Magdcla, which
he afterwards made his principal stronghold, and en'Utcd
many of the chiefs and their followers in his own ranks..
He shortly afterwards reduced the kingdom of Shoa,
and took Ankobar, the capital ; but in the meantime his
own people were groaning under bis heavy exactions,
rebellions were brcalang out in various parts of his pro-
vinces, and his good queen was now dead. He lavished
vast sums of money upon his army, which at one time
amounted to 100,000 or 150,000 fighting men; and in
order to meet this expenditure, he was forced to exact
exorbitant tributes from his people. The British consul,
Plowden, who was strongly attached to Theodore, having
Massowah, was attacked on his way by a rebel nnmed
Garred, mortally wounded, and taken prisoner. Theodore
attacked the rebels, and in the action the murderer of Mr
Plowden was slain by his friend pnd companion Jlr Bell,
but the latter lost his life in preserving that of Theodore.
The deaths of the two Englishmen were terribly avenged by
the slaughter or mutilation of nearly 2000 rebels. Theodore
soon after married his second wife Tcrunish, the proud
daughter of the late governor of Tigr6, who felt neither
affection nor respect for the upstart who had dethroned her
father, and the union was by no means a happy one. In
1862 he made a second expedition against the Gallas, which
was stained with atrocious cruelties. Theodore had now
given himself up to intoxication and lust. When the
news of Mr Plowden's death reached England, Capl.-iin
Cameron was appointed to succeed him as consul, and
arrived at ilassowah in February 1862. He proceeded to
the camp of the king, to whom he presented a rifle, a pair
cf pistols, and a letter in the Queen S nama In October
Captain Cameron was dismissed by Theodore, vriih a letter
to the Queen of England which reached the Foreign Olfice
on the 12th of February 1863. For some reason or other
this letter was put aside and no answer returned, and to
this in no small degree is to be attributed the diiEci;lties
that subsequently arose with that country. After forward-
ing the letter. Captain Cameron, hearing that the Christians
of Bogos had been attacked by the Shangallis and other
tribes under Egyptian rule, proceeded to that district, and
afterwards went to Kassala, the seat of the Egyptian ad-
ministration in that quarter. Thence he t< cut to Metemch,
where he was taken ill, and in order to recruit his health
he returned to Abyssinia, and reached Jenda in August
1803. In November despatches were received from
England, but no answer to the emperor's letter, and this,
together with the consul's visit to Kaisala, greatly
offended him, and in January 1804 Captain Cameron and
his suite, with Messrs Stem and Roscnihal, were cast into
prison. WTien the news of this reached England, the
Government resolved, when too late, to send an answer to
the emperor's letter, and selected Mr Honniizd Rassam to
be its bearer. He arrived at Massowah in July 1804, and
immediately despatched a messenger requesting permission
to present himself before the emperor. Neither to this nor
a subsequent application was any answer returned till
August 1865, when a curt note was received, stating that
Consul Cameron had been released, and if Mr Kassam stilt
ABYSSINIA
67
desired to visit the kiiig, Le was to proceed by the route of
Metemeh. They reached Metemeh on 21at November, and
five weeks more v?ere lost before they heard from the
emperor, whose reply was now courteous, informing them
that the governors of all the districts through which they
every necessary. They left Metemeh on the 28th December,
and on 25th January foDowing arrived at Theodore's camp
in Damot. They were received with all honour, and were
afterwards sent to Kuarata, on Lake Dembea, there to await
the arrival of the captives. The latter reached this on 1 2t'h
March, and everything appeared to proceed very favourably.
A month later they started for the coast, but had not pro-
ceeded far when they were all brought back and put into
confinement. Theodore then wrote a letter to the Queen,
requesting European workmen and machinery to be sent to
him, and despatched it by Mr Flad. The Europeans,
although detained as prisoners, were not at first unkindly
treated ; but in the end of June they were sent to Magdala,
where they were soon afterwards put in chains. They
suffered hunger, cold, and misery, and were in constant
fear of death, tiU the spring of 1868, when they were
relieved by the British troops. In the meantime the power
of Theodore in the country was rapidly waning. In order
to support his vast standing army, the country was drained
of its resources : the peasantry abandoned the fertile plains,
and took refuge in the fastnesses, and large fertile tracts
remained uncultivated. Rebellions broke out in various
parts of the country, and desertions took place among his
troops, till his army became little more than a shadow of
what it once was. Shoa had already shaken ofif his yoke ;
Godjam was virtually independent ; Walkeit and Samen
were under a rebel chief ; and Lasta Waag and the
Gobaze, who had also overrun Tigrc5, and appointed Dejach
Kassai his governor. The latter, however, in 18C7 rebelled
against his master, and assumed the supreme power of that
province. This was the state of matters when the English
troops made their appearance in the country. With a view
if possible to effect the release of the prisoners by con-
ciliatory measures, Mr Flad was sent back, with some
artisans and machinery, and a letter from the Queen,
stating that these would be handed over to his Majesty on
This, however, failed to influence the emperor, and the
, English Governmtnt at length saw that they must have
recourse to arms. In July 1867, therefore, it was resolved
to send an army into Abyssinia to enforce the release of
the captives, and Sir Robert Napier was appointed com-
mander-in-chief. . A reconnoitring party was despatched
beforehand, under Colonel Merewether, to select the landing-
place and anchorage, and explore the passes leading into
the interior. They also entered into friendly relations
with the different chiefs in order to secure their co-operation.
The landing-place selected was Mulkutto, on Annesley Bay,
the point of the coast nearest to the site of the ancient
Adulis, and we are told that " the pioneers of the English
expedition followed to some extent in the footsteps of the
f.dventurous soldiers of Ptolemy, and met with a few faint
traces of this old world enterprise." — C. R. Markliam..
The force amounted to upwards of 16,000 men, besides
12,640 belonging to the transport service, and followers,
making in all upwards of 32,000 men. The task to be
accomplished was to march over 400 miles of a mountainous
and little-known country, inhabited by savage tribes, to
the camp or fortress of Theodore, and compel him to deliver
up his captives. The commander-irk-chief landed on 7th
January 1868, and soon after the troops began to move
forward through the pass of Senaf^, and southward through
Iho districts of AgauKi, Tera, Kndaila, Wojcrat, Lasta, and
great straits. Hia army was rapidly deserting him, and he
could hardly obtain food for his followers. He resolved to
quit his capital Debra Tabor, which he burned, and set
out with the remains of hia army for Magdala. During
this march he displayed an amount of engineering skiU in
the construction of roads, of military talent, and fertility
of resource, that excited the admiration and astonishment
of his enemies. On the afternoon of the 10th of April a
force of about 3000 men suddenly poured down upon the
English in the plain of Arogi^, a few miles from Magdala.
They advanced again and again to the charge, but were
each time driven back, and finally retired in good order.
Early next morning Theodore sent Lieut. Prideaux, one of
the captives, and Mr Flad, accompanied by a native thief,
to the English camp to sue for peace. Answer was returned,
that if he would deliver up aU the Europeans in his hands,
and submit to the Queen of England, he would receive
honourable treatment. The captives were liberated and
sent away, and along with a letter to the English general
was a present of 1000 cows and 500 sheep, the acceptance
of which would, according to Eastern custom, imply that
peace was granted. Through some misunderstanding, word
was sent to Theodore that the present would be accepted,
and he felt that he was now safe ; but in the evening he
seized him. Eai;ly next morning he attempted to escape
with a few of his followers, but subsequently returned.
The same day (13th April) Magdala was stormed and
taken, and within they found the dead body of the
emperor, who had fallen by his own hand. .The inhabitants
and troops were subsequently sent away, the fortifications
destroyed, and the town burned. The queen Terunish
having expressed her wish to go back to her own country,
accompanied the British army^ but died during the march,
and her son Alam-ayahu, the only legitimate son of the
emperor, was brought to England, as this was the desire
of his father. The success of the expedition was in no
small degree owing to the aid afforded by the several native
'chiefs through whose country it passed, and ijo one did
more in this way than Prince Kassai of Tigre. In acknow-
ledgment of this several pieces of ordnance, small arms,
and ammunition, with much of the surplus stores, were
handed over to him, and the English troops left the country
in May 1868. Soon after this Prince Kassai declared his
independence; and in a war which broke out between him
and Wagsham Gobaze, the latter was defeated, and his
territory taken possession of by the conqueror. In 1872
Kassai was cro%vned king of Abyssinia with great ceremony
at Axam, under the title of King Johannes. In that year the
governor of Massowah, Munzinger Bey, a Swiss, by com-
mand of the Viceroy of Egypt, marched an armed force
against the Bogos countr)-. The king solicited the aid of
England, Germany, and Russia .against the Egyptians, whoso
troops, however, were after a time withdrawn. Sir Bartle
Frere, in the blue-book published respecting his mission to
Zanzibar, is of the opinion thot England, having regard to
the passage to India by the Red Sea, should not have wholly
abandoned Abyssinia. (d. k.)
(See Travels of Bn-ce, 1768-73; Lord Valentia, Salt,
1809-10; Combes et Tamieier, 1835-37 ; Ferret et Galinier,
1839-43; RuppeU, 1831-33; MM. Th. Lefebvre, A. Petit, et
Quartin-Dillon, 1839-43; Major Harris; Gobat; Dr C.
Ecke; Isenberg and Krapf, 1839-42; Mansfield Parkyns;
Von Heuglin, 1861-62; H. A. Stern, 1860 and 1863;
DrBknc, 1863; A. Rassam, 1869; C. R. Markham, 1869;
W. T. P.lanford, 1870; liemrdo/lho ExpeditiontoAhyssinia,
compiled -by order of the Secretary of State for War, by
Major T. J. Holland and Captain H. Hozier, 2 vols. 4to,
and plates, 1870; various Parliamentary Papers. 18C7--C8.)
<!8
A C A — A C A
ACACIA, a genuB of shrubs and trees belonging to
the natural family Lcguminosae and thn Bcction Mimosesb.
The flowers oro email,
arranged in rounded or
elongated clusters. The
leaves ore compound
pinnate in genonvL In
some instances, how-
ever, more especially iii
the Australian species,
the leaf-stalks become
flattenetl, and 8er\'e the
purjjoso of leaves; the
plants are hence call-
ed leafless Acacias, and
as the leaf-stalks are
often placed with their
edges towards the sky
and earth, they do not
intercept light so fully
as ordinary trees. There are about 420 species of
Acacias widely scattered over the wanner regions of the
globe. They abound in Australia and Africa. Various
species, such as Acacia vera, arabica, Ehrenbergii, and
tortilis, yield gum arabic ; while Acada Vereic, Seyal, and
Adansonii furnish a siiidlar gum, called gum Senegal These
species are for the most part natives of Arabia, the north-
eastern part of Africa, and the East Indies. The wattles
Leaf of Acacia keUrophylUL
of Australia are species of Acacia with astringent harkt.
Acana dcalbata is used for tanning. An astringent
medicine, called catechu or cutch, is procured from sevend
species, but more especially from Acacia Catechu, by boiling
down the wood and evaporating the solution so as to get
an extract. The bark of Acacia arabica, under the
name of Babul or Babool, is used in Scinde for tanning.
Acacia formosa supplies the valuable Cuba tijnber ca'leti
sabicu. Aco^ria Scyal is the phint which is supposed to be
the shitt-vh tree of the Dible, which supplied sliittim-wood.
The pods of Acaciix nilotica, under the name of neb-neb, are
used by tanners. The seeds of Acacia Niopo are roR.'ited
and used as snuff in South America. The seeds of all the
varieties of Acacia in South Au.stralia to the west, called
Nundo, are used as food after being roasted. Acacia
melaiMxylon, black wood of Australia, sometimes called
light wood, attains a great sue ; its wood is used for
fumituie, and receives a high polish. Acacia homalopkylla,
myall wood, yields a fragrant timber, used for ornamental
purposes. A kind of Acacia is called in Australia Bricklow.
.In common language the term Acacia is often applied to
species of the genus Robiuii, which belongs also to the
Leguminous family, b\it is placpd in a different section.
Jiobiiiia Pseudo-acacia, or false Acacia, is cultivated in
the milder parts of Britain, and forms a large tree, with
beautiful pink pea-like blossoms. The tree is sometimes
called the Locust tree.
ACADEMY, u/.aSiJ;itia,' a subufb of Athens to the north,
forming part of the Ceramicus, about a mile beyond
the gate named Dypihim. It was said to have belonged
to the hero Academus, but the derivation of the word is
unknown. It v/as surrounded with a wall by Hipparchus,
and adorned with walks, groves, and fountains by Cimon,
the son of MUtiades, who at his death bequeathed it as a'
public pleasure-ground to his feUow-citizens. The Academy
was the resort of Plato, who possessed a small estate in the
neighbourhood. Here he taught for nearly fifty years, till
his death in 318 B.o. ; and from those "groves of the
Academy wliere Plato taught the truth," ^ his school, as
distinguished from the Peripatetics, received the name of
The same name (Academia) was in after times given by
Cicero to his viUa or country-house near Puteoli. There
was composed his famous dialogue, TIu Acader.iic Ques-
tions.
Of the academic school of philosophy, in so far as it
diverged from the doctrines of its groat master (see Plato\
we must treat very briefly, referring the reader for parti-
culars to the founders of the various schools, whose names
we shall have occasion to mention.
The Academy lasted from the daj's of Plato to those of
Cicero. As to the number of successive schools, the critics
are not agreed. Cicero himself aud Varro recognised only
two, the old and the new; Sextus Empiricus adds a third,
the middle; others a fourth, that of Philo and Charmidas ;
and some even a fifth, the Academy of Antiochus.
pus, Plato's sister's son, and his immediate successor;
Xenocrates of Chalcedon, who ^vith Speusippus accompanied
Plato in his journey to Sicily; Polemo, a dissolute young
' The bye-fori.i iKxin/iia, which occurs in Diogenes Laertius, is pro-
bably a ralionalistic attempt to interpret the word, such as we com-
monly meet with in the writing? of Piato.
* Horace, £p. ii. 2, ii.
Athenian, who cjime to laugh at Xenocrates, and remained
to listen (Horace, Sat., ii. 3, 253); Crates, and Crantor, the
latter of whom wrote a treatise, Tcpl irci'Oov^, praised by
Cicero. Speusippus, like the Pythagoreans, with whom
Aristotle compares him, denied that the Platonic Good
could be the first principle of things, for (he said) the
Good is not like the germ which gives birth to plants and
animals, but is only to be found in already existing things.
He therefore derived the universe from a primev.^l indeter-
minate unit, distinct from the Good; from this unit he
deduced three principles — one for numbers, one for magni-
tude, and one for the souL The Deity he conceived ta
that living force which rules all and resides everywhere.
Xenocrates, though like Speusippus infected with Pj-th&-
goreauism, was the most faithful of Phto's successors. He
distinguished three essences: the sensible, the intelligible,
and a third, compounded of the other two. The sphere of
the first is all below the heavens, of the second all beyond
the heavens, of the third heaven itself. To each of these
three spheres one of our faculties corresponds. To the sen-
sible, sense; to the intelligible, intellect or reason; to the
mixed sphere, opinion (Sofa). So far he closely follows
the psychology and cosmogeny of his master; but Cicero
notes as the characteristic of both Speusippus and Xeno-
crates, the abandonment of the Socratio principle of
hesitancy.
Of the remaining three, the same writer (who is our prin-
cipal authority for the history of the Academic school) tells
us fliat they preserved the Platonic doctrine, but emphasised
the moral part. On the old Academy he pronounces the
following eulogium (Ve Fin. v. 3); "Their writings and
method contain aU liberal learning, all history, all polite
discourse ; and besides, they embrace such a variety of
arts, that no one can undertake any noble career without
their aid. .... In a word, the Academy is, as it were, the
workshop of every artist." Modem criticism has not en-
dorsed this high estimate. They presened, it is true, and
69
elaborated many details of the Platonic teaching, which wb
could iU have spared; but of Plato's originality and specu-
latire power, of his poetry and enthusiasm, they inherited
nothing ; " nor amid all the learning which has been pro-
fusely lavished upon iuTestigating their tenets, is there a
single deduction calculated to elucidate distinctly the
character of their progress or regression." ^ There is a
saying of Polemo's, which will illustrate their viitual
abandonment of philosophy proper : " We should eiorcise
ourselves in business, not in dialectical speculation."
ArcesUaus, the successor of Crates, the disciple of Theo-
phrastus and Polemo, was the founder of the second or
middle Academy. He professed himself the strict fol-
lower of Plato, and seems to hare been sincerely of opinion
that his was nothing but a legitimate development of the
true Platonic system. He foUowed the Socratic method
of teaching in dialogues; and, like Socrates, left no writ-
ings, — at least the ancients were not acquainted with any.
But we have no evidence that he maintained the ideal
theory of Plato, and from the general tendency of lus
teaching it is probable that he overlooked it. He affirmed
that neither our senses nor our mind can attain to any
certainty; in all we must suspend our judgment; proba-
bility is the guide of life. Cicero tells us that he was
more occupied in disputing the opinions of others than in
advancing any of his own. ArcesUaus is, in fact, the
founder of that academic scepticism which was developed
and systematised by Cameades, the founder of the third
or new Academy. He was the chief opponent of the
Stoics and their doctrine of certitude. This is attested by
a well-known saying of his : "If there had been no Chry-
sippus, there would have been no Cameades." To the
Stoical theory of perception, the <JMvraa-La KaTaXryimKri, by
which they expressed a conviction of certainty arising
from impressions so strong as to amount to science, he
opposed the doctrine of aKaTaXrjipta, which denied any
necessaiy correspondence between perceptions and the
objects perceived. But whUe denying the possibility of
any knowledge of things in themselves, he saved himself
from absolute scepticism by the doctrine of probability or
verisimilitude, which jnay serve as a practical guide in hfe.
Thus he announced as his criterion of truth an imagination
or impression (<f>avTaa-ia.) at once credible, irrefragable, and
attested by comparison with other impressions. The wise
man might be pennitfed to hold an opinion, though he
allowed that that opinion might be false. In ethics, how-
ever, he appeared as the pure sceptic. On his visit to
Rome as an ambassador from Athens, he alternately main-
tained and denied in his public disputations the existence
of justice, to the great scandal of Cato and aU honest
citizens.
On the fourth and fifth Academies, we need not dwell
long. Philo and Antiochus both taught Cicero, and with-
out doubt communicated to him that mild scepticism, that
eclecticism compounded of almost equal sympathy with
Plato and Zeno, which is the characteristic of his philo-
sophical writings. The Academy exactly corresponded to
the( moral and political wants of Eomo. With no genius
for speculation, the better Eomans of that day were con-
tent to embrace a system which, though resting on no
philosophical basis, and compounded of heterogeneous
dogmas, offered notwithstanding a secure retreat from
religious scepticism and political troubles. " My words,"
says Cicero, speaking as a tru.6 Academician, "do not
proclaim the truth, like a Pythian priestess; but I conjec-
ture what is probable, Hke a plain man; and where, I ask,
am I to search for anything more than verisimilitude t"
And again: " The characteristic of the Academy is never to
' Archor Butler, LaC. on Anc. PhiL ii. 8)6
interpose one's judgment, to approve what seems most pro-
bable, to compare together different opinions, to see what
may be advanced on either side, and to leave one's listeners
free to judge without pretending to dogmatise."
AcADEliY, in its modem acceptation, signifies a society
or corporate body of learned men, established for the ad-
vancement of science, literature, or the arts.
The first institution of this sort we read of in history
was that founded at Alexandria by Ptolemy Soter, which
he named the Museum, ji.ovaiiov. After completing his
conquest of Egypt, he turned his attention to the cultiva-
tion of letters and science, and gathered about him a large
body of literary ' men, whom he employed in collecting
books and treasures of art. This was the origin of the
library of Alsxandria, the most famous of the ancient world.
Passing .by the academies which were founded by the
Moors at Grenada, Corduba, and as far east as Samarcand,
the next instance of an academy is that founded by Charle-
magne at the instigation of the celebrated Alcuin, foi
promoting the study of grammar, orthography, rhetoric,
poetry, history, and mathematics. In order to equalise all
ranks, each member took the pseudonym of some ancient
author or celebrated person of antiquity. For instance,
Charlemagne himself was David, Alcuin became Flaccua
Albinus. Though none of the labours of -this academy
have come down to us, it undoubtedly exerted considerable
influence in modelling the lan^age and reducing it to rules.
In the following century Alfred founded an academy at
Oxford. This was rather a grammar school than a society
of learned men, and from it the University of Oxford
originated.
But the academy which may be more justly considered
as the mother of modern European academies is that of
Floral Games, founded at Toulouse in the year 1325, by
Clemens Isaurus. Its object was to distribute prizes and
rewards to the troubadours. The prizes consisted of
flowers of gold and silver. It was first recognised by the
state in 1694, and confinned by letters-patent from the
king, and its numbers limited to thirty-six. It has, except
during a few years of the republic, continued to the present
day, and distributes annually the following prizes : — An
amaranth of gold for the best ode, a silver violet for a
poem of sixty to one bundled Alexandrine lines, a silver
eglantine for the best prose composition, a silver marigold
for an elegy, and a silver lily presented in the last century
by M. de Malpoyre for a hymn to the Virgin.
It was the Pienaissance which was par excelle^ice the era
of academies, and as the Italians may be said to have dis-
covered anew the buried world of literature, so it was in
Italy that the first and 'by far the most numerous academies
arose. The earliest of these was the Platonic Academy,
founded at Florence by Cosmo de Medici for the study of
the works of Plato, though subsequently they added the
explanation of Dante and other Italian authors.
Marsilius Ficinus, its principal ornament, in hxsTiieologica
Platonica, developed a system, chiefly borrowed from the
later Platonists of the Alexandrian school, which, as it
seemed to coincide with some of the leading doctrines ol
Christianity, was allowed by the church. His Latin trans-
lation of Plato is at once literal, perspicuous, and coirect
several places enabled us to recover the original reading.
After the expulsion of the Medici from Florence, tht
In giving some account of the principal acadelnies o<
shall, as far as possible, arrange them under difl'erent heads,
according to — \st, The object which they were designed
to promote; id. The countries to which they belong.
Tliis classification, though, perhaps, the best available, is
70
necessarily imperfect, inasmuch as several of those we shall
mention were at onco literary and scientific, and many
associations for similar objects were known by some other
naino. Thus, with the doubtful exception of the Royal
senao of the word. For those institutions in England which
the article Society.
L SciENTiKio Academies. — Italy. — The first society
for the prosecution of physical science was that established
at Naples, 1560, under the presidency of Baptisla Porta.
It Was called Academia Secretorum Naturae or de Secreti.
It arose from a meeting of some scientific friends, who
issembled at Porta's house, and called themselves the Otiosi.
discovery in medicine or natural philosophy. The name
suggested to an ignorant public the prosecution of magic
&nd the black arts. Porta wont to Rome to justify himself
before Paul III. He was acquitted by the Pope, but tho
academy was dissolved, and ho was ordered to abstain for
the future from the practice of all illicit arts.
founded by Federigo Ccsi, tho Marcese di Monticelli. The
device of the Lincei was a lynx with its eyes turned towards
heaven tearing a Cerberus with its clav,-s, intimating that
they were prepared to do bat1,le vdth. error and falsehood.
Their motto was the verse of Lucretius describing rain
dropping from a cloud — " Redit agmine dulcL" Besides
Porta, Galileo and Colonna were enrolled among its mem-
bers. The society devoted itself exclusively to physical
science. Porta, aiidor its auspices, published his great work,
Mar/i(B Naturalii lihri xx., 1589, in foL; his Fhytor/no-
manica, or, tho occult virtue of plants; his De JIumanaPby-
tiognomia, from which Lavater largely borrowed ; also various
works on optics and pneumatics, in which he approached
the true theory of vision. He is even said by some to
have anticipated QalUeo in the invention of the telescope.
But the principal monument still remaining of the zeal
and industry of Cesi and his academy is the Phytobasanos,
a corapendiuni of the natural history of Me.\ico, written by
a Spaniard, Ilernendez. During fifty ye.ars the MS. had
been neglected, when Cesi discovered it, and employed
Terentio, Fabro, and Colonna, all Lynceans, to edit it and
enrich it with notes and emendations. Cesi's own great
work, Tlieatrum Natures, was never published. The MS.
still exists m the Albani Library at Rome. After Cesi's
death, 1630, the academy languished for some years under
the patronage of Urban VIIL An fxiademy of the same
name was inaugurated at Rome 17'&4, and still flourishes.
It numbers among its members some of our English philo-
sophers. But the fame of the Lincei was far outstripped
by that of the Accadcmia del Cimento, established in
Florence 1657, under the patronage of the Grand Duke
Ferdinand II., at tho instigation of his brother Leopold,
acting under the advice of Viviani, one of the greatest
geometers of Europe. The object of this academy was
(as the name implies) to make experiments and relate them,
abjuring all preconceived notions. Unfortunately for
science, it flourished for only ten years. Leopold in 16G7
was made a cardinal, and tho society languished without
ils head. It has, however, left a record of its labours in
k volume containing an account of the experiments, pub-
lished by the secretary in 1667. It is in the form cf a
beautifully printed folio, with numerous full print pages of
illustrations. It contains, among others, those on the
supposed incompressibility of water, on the pressure of the
air, and on the universal gravity of bodies. Torricelli, the
inventor cf the barometer, was one of its members.
Passing by numerous other Italian Academics of Science,
We come to those ot modern timea.
Tho Royal Academy of Sciences at Turin originated in
1757 as a private society; in 1759 it published a volume
of Miscellanea Philoaophtco-MalJtematica Societatu privala
3'aurinettsis ; shortly after it was constituted a Royal
Society by Charlss Emanuel IIL, and in 1783 Victor
consists of 40 membars, residents of Turin, 20 non-
resident, and 20 lorei^ members. It publishes each
year a quario volume of proceedings, and has crowned
and awarded prizes to many learned works.
France, — Tho Old Academy of Sciences originated in much
the same way as the French Academy. A private society
of scientific men had for some thirty years been accustomed
to meet first at the house of Montmort, tho militre de«
requetes, afterwards at that of Thevenot, a great traveller
and man of universal genius, in order to converse on their
studies, and comhiunicate their discoveries. To this
society belonged, among others, Descartes, Gassendi,
Blaise Pascal, and his father. Hobbes, the philosopher
of Malmcsbury, was presented to it during his visit .to
Paris in 1640. Colbert, just as Richelieu in the case
of the French Academy, conceived the idea of giving an
official status to this body of learned men. Seven eminent
mathematicians, among whom were Huyghens and De
Bessy, the author of a famous treatbe on magic squares,
were chosen to form the nucleus of the new society. A
certain number of chemists, physicians, and anatomists
were subsequently added. Pensions were granted by
Loub XIV. to each of tho members, and a fund for
instruments and experimentations placed at their disposal.
They commented their session the 22d December 1666
in tho Royal Library. They met twice a week — the
mathematicians on tho Wednesdays, the physicists (as the
naturalists and physiologists were then called) on the
S.aturdays. Duhamel was appointed secretary by the
king. This post ho owed more to his polished Latinity
than to his scientific attainments, all the proceedings
of the society being recorded in Latin. A treasurer
was also nominated, who, notwithstanding his pretentious
title, was nothing more than conservator of the scientific
instruments, &c. At first the academy was rather a
laboratory and observatory than an academy proper.
Experiments were undertaken in common and results
discussed. Several foreign savap-ts, in particular the
Danish astionomer Rocmer, joined the society, attracted
by the liberality of the Grand Monarque; and the German
physician and geometer Tschimhausen and Sir Isaac
Newton were made foreign a-ssociates. The death of
Colbert, who was succeeded by Louvois, exercised a disas-
trous effect on tho fortunes of the academy. The labours
of the academicians were diverted from the pursuit of
pure science to such works as the construction of fountains
and cascades at Versailles, and tho mathematicians were
employed to calculate the odds of the games of lansquenet
and bassett. In 1699 the academy was reconstituted
by M. do Pontchartrain, under whose department as
secretary of state the academies came. By its new con-
stitution it consisted of ten honorary members, men of
high rank, who interested themselves in science, fifteen
pensionaries, who were the working members, viz., three
geometricians, and the same number of astronomers,
mechanicians, anatomists, and chemists. Each section of
three had two associates attached to it, and besides, each
pensionary had the power of naming a pupil There were
eight foreign and four free associates. The officers were,
a president and a vice-president, named by tho king from
among the honorary members, and a secretary and treaisurer
chosen from tho pensionaries, who held their offices for
life. Fontenelle, a man of wit, and rather a populariser of
sciences than an original investigator, succeeded Duhamel as
7j
secretary. Tte constitution, as is evident, was purely aristo-
cratical, and unlike that of the French Academy, in which
the principle of equality among the members was never
violated. Science was not yet strong enough to dispense
with the patronage of the great. The two leading spirits
of the academy at this period were Clairaut and Reaumur.
Clairaut was the first to explain capillary attraction, and
predicted within a f^w days of the correct time the return
of HaUey's comet. His theory on the figure of the earth
was only superseded by Laplace's Mecanique Celeste.
R&,umur was principally distinguished by his practical
discoveries, and a thermometer in common use at the
present day bears his name.
To trace the subsequent fortunes of this academy would
far exceed our limits, being equivalent to writing the history
of the rise and progress of science in France. It has
reckoned among its members Laplace, BufFon, Lagrange,
D'Alembert, Lavoisier, and Jussieu, the father of modern
botany. Those of our readers who wish for further informa-
tion we would refer to M. Alfred Maury's excellent history.
On 21st December 1792, the old Academy of Sciences
met for the last time. Many of the members fell by the
guillotine, many were imprisoned, more reduced to indi-
gence. The aristocracy of talent was almost aa much
detested and persecuted by the Revolution as that of rank.
In 1795 the Convention decided on founding an Insti-
tute, which was to replace all the academies. The first
class of the Institute corresponded closely to the old
In 1816 the Academy was reconstituted as a branch of
the Institute. The new academy has reckoned among its
members, besides many other brilliant names, Camot the
engineer, the physicians Fresnel, Ampere, Arago, Biot, the
chemists Gay-Lussao and Thtoard, the zoologists G. Cuvier
and the two Geoffroy Saint-Hilaires.
their large towns. Montpellier, for example, had a Royal
Academy of Sciences, founded in 1706 by Louis XIV., on
nearly the same footing as that at Paris, of which, indeed,
it was in some measure tho counterpart. It was recon-
stituted in 1847, and organised under three sections —
medicine, science, and letters. It has continued to publish
annual reports of considerable value. Toulouse also had
an academy under the denomination of Lanternists; and
there were analogoiis institutions at Nlmes, Aries, Lyons,
Dijon, Bordeaux, and other places. Of these several, we
believe, are stUl in existence, if not in activity.
Before passing on to German academies, we may here
notice a private scientific and philosophical society, the
precursor of the French Academy of Sciences. It does not
appear to have had any distinguishing name ; but the pro-
moter of it was Euscbius Renaudot, Counsellor and Phy-
sician in Ordinary to the King of France, and Doctor
Regent of the Faculty of PlrjBjic at Paris, by whom a full
account of its conferences was published, translated into
English by G. Havers, 1664. In the preface it is said to
be " a production of an' assembly of the choicest wits of
France.'' We will quote a few of the subjects of these
discussions in order to show the character of the society : —
"Why the loadstone draws iron;" "Whether the soul's
immortality is demonstrable by natural reason ;" " Of the
little hairy girl lately seen in this city." . On subjects of
popular superstition their views were far in advance of the
time. Of judicial astrology it is said, "Why should we
seek in heaven the causes of accidents which befall us if
we can find them on earth!" Of the philosopher's stone —
" This most extravagant conceit, that it is the panacea,
joined to the othw absurdities of that chimerical art, makes
us believe that it is good for nothing but to serve for
'maginary consolation to tho miserablo."
Germany. — The ■ Collegium Curiosum was a scientific
society, founded by J. C. Sturm, professor of mathematics
and natural philosophy in the University of Altorfi', in
Franconia, in 1672, on the plan of the Accademia del
Cimento. It originally consisted of 20 members, and con-
tinued to flourish long after the death of its founder. The
early labours of the society were devoted to the repetition
(under varied conditions) of the most notable experiments
of the day, or to the discussion of the results. Two volumes
respectively. The Programma Invitatwium is dated June
3, 1672; and Sturm therein urges that, as the day of dis-
putatious philosophy had given way to that of experi-
mental philosophy, and as, moreover, scientific societies had
been founded at Florence, London, and Rome, it would
therefore seem desirable to found one in Germany, fof the
attainment of which end he requests the co-operation of
the learned.
The work of 1676, entitled Collegium Experimentode sive
Curiosum, commences with an account of the diving-bell,
" a new invention ; " next follow chapters on the camera
obscura, the Torricellian experiment, the air-pump, micro-
scope, telescope, &c. The two works have been pronounced
by a competent authority ' to constitute a nearer approach
to a text-book of the physics of the period than any pre-
ceding work.
The Royal Academy of Sciences at Birlin was founded
in 1700 by Frederic I. after Leibnitz' ccsiprehensive plan,
but was not opened tiU 1711. Leibnitz was the first presi-
dent. Undfer Maapertuis, who succeeded him, it did good
service. Its present constitution dates from January 24,
1812. It is divided into four sections — physical, mathe-
matical, philosophical, and historical Each section is imder
a paid secretary elected for life ; each secretary presides in
turn for a quarter of a year. The members are — \st. Re-
gular members who are paid; these hold general meetings
every Thursday, and sectional meetings every Monday. 2rf,
Foreign members, not to exceed 24 in number. ?>d, Hon-
orary members and correspondents. Since 1811 it has
published yearly, Meinoires de I'Academie Eoyale des Scienceg,
et Belles Leltres d Berlin. For its scientific and philoso-
phical attainments the names of W. and A. v. Humboldt,
Ideles, Savigny, Schleiermacher, Bopp, and Eanke, will
sufiiciently vouch.
The Academy of Sciences at Mannheim was established
by Charles Theodore, Elector Palatine, in the year 1755.
The plan of this institution was furnished by Sch^pflin,
according to which it was divided into two classes, the his-
torical and physical In 1780 a sub-division of the latter
took place into the physical, properly so-called, and the
meteorologicaL The meteorological observations are pub-
lished separately, under the title of l^hemerides Societatis
Meteorologies PalatincB. The historical and physical me-
moirs are published under the title of Acta Academim
Theodoro-Palatince.
The Electoral Bavarian Academy of Scie/ices at Munich
was established iu 1759, and publishes its memoirs under
the title of Abhandlungen der Baierisc/)en Akademie. Soon
after the Elector of Bavaria was raised to the rank of king,
tho Bavarian government, by his orders, directed its atten-
tion to a new organisation of the Academy of Sciences of
MunicL The design of the king was, to render its labours
more extensive than those of any similar institution in
Europe, by giving. to it, under the direction of the minis try,
the immediate superintendence over all the establishments
for public instruction in the kingdom of Bavaria. The Privy-
Councillor Jacobi, a man of most excellent character, and of
considerable scientific attainments, was appointed president
^ Mi O. F. BodwtO. In tbo Chanical Neun,.JiiM 21, 1867.
Tlic Electoral Academy at Erfurt was establitiliecl by llie
Elector of Meutz, in tho year 1754. It consists of a pro-
tector, president, director, assessors, adjuncts, and asso-
ciiatcs. Its object is to promote the useful Bcicnccs. Tho
memoirs were originally published in Latin, but afterwards
in German. Tho Ilessiin Academy of Sciences at Oie&sen
publish their transactions under the title of Acta Philo-
lu the Nethe-lands there are scientific acaduinies at Flush-
ing and Brussels, both of which have published their
transactions.
litissia.—'Yha Imperial Academy of Sciences at St
Petersburg was projected by tho Czar Peter the Great.
Having in tho course of his travels observed tho advan-
tage of public societies for tho encouragement and promo-
tion of literature, ho formed the design of founding an
of Wollf and Loibnitz, whom ho consulted on this occasion,
the society was accordingly regulated, and several learned
foreigners were invited to become members. Peter him-
self drew the plan, and signed it on the lOlh of .February
1721; blithe wms jirevented, by the suddenness of his
death, from carrying it into execution, llis decease, how-
ever, did not prevent its completion; for on the 2l6t of
December 1725, Catharine L established it occording to
Peter's plan, and on the 27th of the same month the society
assembled for the first time. On the Ist of August 1726,
Catharine honourfed the meeting with her presence, when
Professor Bulf-nger, a German naturijist of great eminence,
theory of magnetic variations, and also on the progress of
research in so far lis regarded tho discovery of the longi-
tude. A short tiuio afterwards the empress settled a fund
of i4982 per annum for the support of the academy; and
15 members, all eminent for their learning and talents,
were admitted and pensioned, under tho title of professors
in the vaiious branches of science and literature. Tho most
distinguished of these professors were Nicholas and Daniel
BeniouilU, the tv o Do Lislcs, Bulfinger, and Wolff.
During the short reign of I'etcr IL the salaries of the
members wcro discontinued, and the academy utterly
neglected by the Court; but it was again patrouiscd by the
Kmpress Anne, who even added a seminary for tho educa-
tion of youth under the superintendence of the professors.
Both institutions flourished for some time under the
direction of Baron Korf ; but upon his death, towards the
end of Anne's reign, an ignorant person being appointed
president, many of the moot able members quitted Kussia.
At the accession of Elizabeth, however, new life and vigour
were infused into the academy. Tho original plan was
enlarged and improved ; some of the most learned foreigners
■were again drawn to St Petersburg ; and, what was considered
as a good omen for the Hterature of Russia, two natives,
Lamonosof and Bumovsky, men of genius and abilities,
Avho had prosecuted their studies in foreign universities,
were enrolled among its members. Lastly, the annual
income was increased to X10,G59, and sundry other advan-
tages were conferred upon the institution.
The Empress Catharine II., with her usual zeal for
promoting the diffusion of knowledge, took this useful
society under her immediate protection. She altered tho
court of directors greatly to the advantage of tho whole
body, corrected many of its abuses, and infused a new
vigour and spirit into their researches. By Catharine's
particular recommendation the most ingenious professors
visited the various provinces of her vast dominions ; and as
tho funds of the academy were not sufficient to defray the
whole expense of these expeditions, tho empress supplied
the deficiency by a grant of £2000, which was renewed as
occasion required.
Tlio jiurpose and object of these travels will appear from
tho instructions givon by the academy to the several per-
sons who engaged in them. They were ordered to iustituto
inquiries respecting tho dilferent sorts of earths and waters;
tho best methods of cultivating barren and desert spots;
tho local disorders incident to men and animals, together
with tho most efficacious means of reIie\Tng them; tho
breeding of cattle, particularly of sheep; the rearing of bees
and silk-worms; the different places and objects for fishing
and hunting; minerals of all kinds; the arts and trades;
and tho formation of a Flora Kussica, or collection of mdi-
genoua plants They were particularly instnicted to rectify
the longitude and latitude of the principal towns; to make
astronomical, geographical, and meteorological obscrva
tions; to trace tho courses of rivers; to construct the most
exact charts; and to bo very distinct and accurate in re
marking and describing tho manners and customs of the
different races of people, their dresses, languages, anli-
(piitics, traditions, history, religion ; in a word, to gain
every information which might tend to illustrate the real
state of tho whole liussian empire. Jloro ample instruc-
tions cannot well bo conceived; and they appear to have
been very zealously and faithfully executed. The conse-
quence was that, at that lime, no country could boast,
within tho space of so few years, such a number of excellent
publications on its internal state, its natural productions,
its topography, geography, and history, and on the manners,
customs, and languages of the different tribes who inhabit
it, as issued from the press of this academy. In its researches
in Asiatic languages, and general knowledge of Oriental
customs and religions, it proved itself the worthy rival of
our own Boyal Asiatic Society.
The first transactions of this society were published in
1728, and entitled Commentarii Academiw Scientiarum
Imperial is Petropolitance ad annum 1726, with a dedica-
tion to Peter II The publication was continued under
this form until tho year 1747, when the transactions wero
called A'^oi'i Cummentarii Academiae, ilc;.and in 1777, the
tiarum Imperialis I'etropoliiance, and likewise made some
alteration in the arrangements and plan of tho work. The
papers, which had been hitherto published in the Latin
language only, were now written indiflcrently either in
that language or in French, and a preface added, entitled
Partie Hislorique, which contains an account of its pro-
ceedings, meetings, the admission of new members, and
other remarkable occurrences. Of tho Commentaries, H
volumes were published: the first of the Kew Commen-
taries made its appeaiancc in 1750, and the twentieth in
1776. Under the new title of Acta Academice, a number of
volumes have been given to the public; and two are printed
every year. These transactions abound with ingenious and
elaborate disquisitions upon various parts of science and
natural history; and it may not be an exaggeration to assert,
that no society in Europe has more distinguished itself for
the excellence of its publications, particularly in the more
abstruse parts of pure and mixed mathematics.
The academy is stiU composed, as at first, cf 15 pro-
fessors, besides the president and director. Each of these
prof essors has a house and an annual stipend of from £200
to £G00. Besides the professors, there are four adjuncts,
with pensions, who are present at the sittings of the society,
and succeed to the first vacancies. The direction of the
academy is generally entrusted to a perion of distinction.
The buildings and apparatus of this academy are on a
vast scale. There is a fine library, consisting of 36,000
curious books and manuscripts ; together with an extensive
museum, in which the various branches of natural hietory,
(tc, are distributed in different apartments. The latter is
extremely rich iJi native productions, havine been cousi-
73
dorably augmented by the collections made by Pallas,
Gmeliu, Guldenstaedt, and other professors, during their
expeditions, tbrough the various parts of the Russian em-
pire. The stuffed animals and birds occupy one apartment.
The chamber of rarities, the cabinet of coins, ic, contain
innumerable articles of the highest curiosity and value.
The motto of the society is exceedingly modest; it consists
of only one word, J'aulaiim.
Sweden. — The Academy of Sciences at Stockholm, or the
RoyaX Swedish Academy, owes its institution to sis persons
of distinguished learning, among whom was the celebrated
Linn.T.us. They originally met on the 2d of June 1739,
when they formed a private society, in which some dis-
sertations were read ; and in the end of the same year
their first publication made its appearance. As the meet-
ings continued and the members increased, the society
attracted the notipe of the king; and, accordingly, on the
31st of March l741, it was incorporated under th« name
of the Koyal Swedish Academy. Not receiving any pen-
sion from the crown, it is merely under the protection of
the king, being <lirected, like our Royal Society, by its own
members. It has now, however, a large fund, which has
chiefly arisen from legacies and other donations ; but a pro-
fessor of experimental philosophy, and two secretaries, are
still the only persons' who receive any salaries. Each of
the members resident at Stockholm becomes president by
rotation, and continues in office during three months.
There are two kinds of members, native and foreign ; the
election of the former take places in April, that of the latter
in July; and no money is paid at the time of admission.
The dissertations read at each meeting are collected and
pubUshed four times in the year : they are written ia the
Swedish language, and printed in octavo, and the annual
publications make a volume. The first 40 volumes, which
were completed in 1779, are caUed the Old Transactions.
Denmark. — The Royal Academy of Sciences at Copen-
Tiagen owes its institution to the zeal of tis: individuals,
whom Christian -VX, in 1742, ordered to r.rrange his cabinet
of medals. These persons were John Gram, Joachim Fre-
deric Ramus, Christian Louis Scheid, Mark Woldickey,
Eris Pontopidan, and Bernard Moeknan, whe, occasionally
meeting for this purpose, extended their designs; associated
with them others who were eminent in several branches of
science ; and f erming a kind of literary society, employed
themselves in searching into, and explaining the history and
ailtiquities of their countr)'. The Count of Holstein, the
first president, warmly patronised this society, and recom-
mended it so strongly to Christian VI. that, in 1743, his
Danish majesty took it imder his protection, called it the
Royal Academy of Sciences, "endowed it with a fund, and
ordered the members to join to their former pursuits
natural history, physics, and mathematics. In consequence
of the royal favour the members engaged with fresh zeal
in their pursuits ; and the academy has. published 15
volumes in the Danish language, some of which have been
translated into L^tin,
Utigland. — In 161G a scheme for founding a Royal
Academy was started by Edmund Bolton, an eminent
scholar and antiquary. Bolton, in his petition to King
Jamee, which was supported by George Villiers, Marquis of
Buckingham, proposed that the title of the academy should
be " K i n g Jame."!, his Academe or College of honour."
In the list of members occurs the name of Sir Kenelm
Digby, one of the original membora of the Royal Society.
The death of the king proved fatal to the undertaking.
nudfff the patronage of Charles I., with the title of
" Minerva's Musaeum," for the instruction of young noble-
men in the liberal arts and sciences, but the project was
30on dropped. About 1645 seme of the more ardent followers
1—4*
of Bacon used to meet, some in London, some at Oxford,
for the discussion of subjects connected with expeiimental
science. This was the origin of the Royal Society, vrhich
received its charter in 1662. See RoTAi SociEry.
Ireland. — The Royal Irish Academy arose out of a
society established at Dublin about the year 1782, and
; Sonsisting of a number of gentlemen, most of whom
belonged to the university. They held Weekly meetings,
and read es.-ays in turn on various subjects. The members
of this society afterwards formed a more extensive plan,
their new institution, became the founders of the Royal
of science with the history^ of mankind and polite literature.
The first volume of their transactions (for 1787) appeared
in 1788, and seven volumes were afterwards published.
A society was formed in Dublin, similar to the Royal
Society in London, as early as the year 1683 ; but the
distracted state of the country proved unpropitious to the
cultivation of philosophy and literature.
Holland. — The Royal Academy of Sciences at Amsterdam,
erected by a royal ordinance 1852, succeeded the Royal
Institute of the Low Countries, founded by Louis Napoleon,
King of Holland, 1808. In 1855 it had pubHshed 192
volumes of proceedings, and received an annual subsidy of
14,000 florins from the state.
1774, after the model of the French Academy.
Portugal. — The Academy of Sciences at Lisbon is divided
into three classes — natural history, mathematics, and ■
national literature. It consists of 24 ordinary and 33
extraordinary members. Since 1779 it has published
Mejxorias de Letteratura Poirlvgueza ; Memorias Rcmiomicas :
CoHec^ao de Livros ineditos di Historia Portvgueza.
II. Academies op BeIxLes Lettees. — Italy. — Italy in the
16th century was remarkable for the number of its literary
academies. Tiraboschi, in his History of Italian Literature,
has given a list of 171 ; and Jarkius, in his Specimen^
700. Many of these, with a sort of Socratic irony, gave
themselves lames expressive of ignorance or simply ludi-
crous. Such were the Lunatici of Naples, the listravaganti,
the Pulminales, the Trapsssati, the Drcrxsy, the Sleepers,
the Ajixiovs, the Confused, the Unstable, the Fantastic,
the Transformed, the ditherial. " The first academics of
Italy chiefly directed their attention to classical literature ;
they compared manuscripts; they suggested new readings, or
new interpretations; they deciphered inscriptions or coins;
they sat in judgment' on a Latin ode, or debated the pro-
priety of a phrase. Their own poetry had; perhaps, neves
been neglected ; but it was not tiU the writings of Bembo
furnished a new code ef criticism in the Italian language,
that they began to study, it with the same minuteness as
modem Latin." " They were encouragera of a numis-
matic and lapidary erudition, elegant in itself, and thi-ow-
ing for ever Uttle specks of light on the still ocean of the
past, but not very favourable to comprehensive observation,
and tending to bestow on an unprofitable p£d.".ntry the
honours of real learning."- The Italian nobility, excluded
as they mostly were from politics, and living in cities,
found in literature a consolation and a career. Sucb
academies were oligarchical in their constitution ; they
encouraged culture, but tended to hamper genius and
extingui.sh originality. Of their academies, by far the
most celebrated was the Accademia delta Crusca or Fiir-
f-aratorum ; that is, of Bran, or of the Sifted.^ The title
was borrowed from a p.revious society at Perugia, the
Accademia flegli Scosti, of the Well-shaken. Its device
' Qallam'a [nt. to Lit. qf Euro^, vol.
65 1. ai.<1 v.il. U. 60?.
L — lO
74
A C A D E 2il r
was a sieve ; its motto, " 11 pit bel fior ne coglie," it
collects the fiaest flour of it ; its principal object the puri-
6catioa of the language. Its great work was the Vocahu-
lario delta Crusca, the first edition of which was published
1613. It was composed avowedly oq Tuscan principles,
iind regarded the Hth century as tTie Augustan period of
the language. Beni assailed it in his ArUi-Cruaca, and
this exclusive Tuscan spirit has disappeared in subsequent
editions. The Accademia della Crusca is now incorporated
with two older societies — the Accademia degli Apatici
(the Impartials) and the Accademia Fiorentina.
Among the numerous other literary academies of Italy
mo by Alfonso, the king; the Academy of Florence,{o\iuded
1540, to illustrate and perfect the Tuscan tongue, especially
by a close study of Petrarch ; the IrUronati of Siena, 1525;
the IiifiamTnati of Padua, 1634 ; the Jiossi of Siena, sup-
pressed by Cosmo, 1568.
Rome in the marriage of Lorenzo Marcini, a Roman gentle-
man, at wliich several persons of rank were guests. It
was carnival time, and so to give the ladies some diversion,
they betook themselves to the reciting of verses, sonnets,
Bpteches, first extempore, and afterwards pre^ieditately,
which gave them the denomination of Belti Uumori.
After some experience, and coming more and more into
the taste of these exercises, they resolved to form an
academy of belles lettres, and changed the title of Belli
Uumori for that of II umoristi.
established at Rome, for the purpose of reviving the study
of poetry. The founder Crescimbeni is the author of a
well-known history of Italian poetry. It numbered among
its members many princes, cardinals, and other ecclesias-
tics; and, to avoid disputes about pre-eminence, aU appeared
massed after the manner of Arcadian shepherds. Within
ten years from its first establishment the number of
The Royal Academy of Savoy dates from 1719, and was
emblem is a gold orange tree fuU of flowers and fruit; its
motto " Flores fructusque perennes," being the same as
those of the famous Ftorimentane Academy, founded at
Annecy by St Francis de Sales. It has published valuable
memoirs on the history and antiquities of Savoy.
Germany. — Of the German literary academies, the
most celebrated was Die Fruchtbrinyende Gesellschaft, the
Fruitful Society, established at Weimar 1617. Five
princes enrolled their names among the original members.
The object was to purify the mother tongue. The German
academies copied those of Italy in their quaint titles and
petty ceremonials, and exercised little permanent influence
on the language or literature of the country.
France. — The French Academy was established by order
of the king in the year 1635, but in its original form it came
into existence some four or five years earlier. About the
year 1629 certain literary friends in Paris ag?eed to meet
weekly at the house of one of their number. These meet-
ings were quite informal, but the conversation turned mostly
on literary topics; and when, as was often the case, one of
rest, and they gave their opinions upon it. The place of
meeting was the house of M. Conrard, which was chosen
as being .the most central. The fame of these meetings,
though the members were bound over to secrecy, reached at
length the ears of Cardinal Richelieu, who conceived so
high an opinion of them, that he at once promised them
his protection, and ofl'ercd to incorporate them by letters
patent. Nearly all the members would have preferred the
charms of privacy, b'lt, considering the risk they would run in
incurring the cardinal's displcaaure, and that by tbo letter
of the law all meetings of any sort or kind were prohibited,
they expressed their gratitude for the high honour the
cardinal thought fit to confer on them. They proceeded
at once to organise their body, settle their laws and constitu-
tion, appoint officers, and choose their name. Their oflBcera
consisted of a director and a chancellor, both chosen by
lot, and a permanent secretary, chosen by votes. They
elected besides a publisher, not a member of the body.
The director presided at the meetings, being considered
iis primus inter pares, and performing much the same part
as the speaker in the English House of Commons. The
chancellor kept the eeab, and sealed all the oflicial docu-
ments of the academy. The office of the secretary explaim
itself. The cardinal was ex oficio protector. The meet-
ings were weekly as before.
The letters patent were at once granted by the king, but
it was otdy after violent opposition and long 'delay that the
president, who was jealous of the cardinal's authority, con-
sented to grant the verification required by the old con-
stitution of France.
The object for which the academy was founded, as set forth
in its statutes, was the purification of the French language.
" The principal function of the academy shall be to labour
with all care and diligence to give certain niles to our
language, and to render it pure, eloquent, and capable of
treating the arts and sciences" (Art 24). They proposed
" to cleanse the language from the impurities it has con-
tracted in the mouths of the common people, from the
jargon of the lawyers, from the misusages of ignorant
courtiers, and the abuses of the pulpit" — Letter of Academy
to Cardinal Richelitu.
Their numbers were fixed at forty. The original members
who formed the nucleus of the body were eight, and it was
not till 1639 that the fuU number was completed. Their
first undertaking consisted of essays written by all the
members in rotation. To judge Iiy the titles and speci-
mens which have come down to us, these possessed no
special originality or merit, but resembled the «ri8«'^is of
the Greek rhetoricians. They next, at the instance of
Cardinal Richelieu, undertook a criticism of CorneUle's
Cid, the most popular work of the day. It was a rule of
the academy that no work could be criticised exccjit at the
author's request. It was only the fear of incurring the
cardinal's displeasure which wrung from Comeille an tin-
willing consent. The critique of the academy was re-
written several times before it met with the cardinal's
approbation. After six months of elaboration, it was pub-
lished imder.tho title. Sentiments de t Academic Fran^oise
sur le Cid. This judgment did not satisfy Comeille, as a
saying attributed to him on the occasion shows. " Ilora-
tius," he said, referring to his last play, " was condemned
by the Duumviri, but ho was absolved by the people."
But the crowning labour of the academy, commenced in
1639, was a dictionary of the French language. By the
twenty-sixth article of their statutes, they were pledged to
compose a dictionary, a grammar, a treatise on rhetoric,
and one on poetry. lu. Chapelain, one of the original
that the dictionary would naturally be the first of these
works to be undertaken, and drew tip a plan of the work,
which was to a great extent carried out A catalogue was
to be made of all the most approved authors, prose and verse :
these were to be distributed among the members, and aU
words and phrases of which they approved to be marked
by them in order to be incorporated in the dictionary.
For this they resolved themselves into two committees,
wliich sat on other than the regular days. M. de Vaugelas'
' A ion mot of bis is w^rth recording. Wbeu returning thrnks foi
A C A D E M if
76
frus appointed editor in chief. To remunerate Mm for his
labours, he received from the cardi^ai a peii"ion of 2000
francs. The first edition of thi." dictionary appeared in
1691, the last Complement in 185-1.
which, like its two younger sisters, the Academy of
Sciences and the Academy of Inscriptions, was suppressed
in 1793, and reconstituted in 1795, as a class of the Insti-
tute, — a history which it would be impossible to treat
adequately in the limit of an article, we will attempt
briefly to estimate its influence on French literature and
language, and point out its principal merits and defects.
To begin with its merits, it may justly boast that there is
h.ardly a single name of the first rank among French
litterateui-s that it has not enrolled among ita members.
Moliire, it is true, was rejected as a player; but we can
hardly blame the academy for a social prejudice which it
shared with the age; and it is well known that it has, ao
far as was in its power, made the amende honorable. In
the Salle 'cles Seances is placed the bust of the greatest
of modern comedians, with the inscription, " Rien ne
manque \ si gloire ; il manquait Ji la notre." Descartes
was excluded from the fact of his residing in Holland.
Scarron was confined by paralysis to his own house.
Pascal is the only remaining exception, and Pascal was
better known to his contemporaries as a mathematician
than a writer. His Lettres Provinciales were published
anonymously; and just when his fame was rising he
retired to Port-Koyal, where he lived the life of a recluse.
On the other hand, it cannot be denied that the fauteuils
have often been occupied by men of no mark in literature.
Nor is the academy wholly exonerated by M. Livet's in-
genious defence, that there are but eight marshals in the
French army, and yet the number has never appeared too
restricted ; for its most ardent admirers vnR not assert that
it has, as a rule, chosen the forty most distinguished living
authors. Court intrigue, rank, and finesse have too often
prevailed over real merit and honesty. Though his facts
are incorrect, there is much truth in Courier's caustic
satire : — " Dans une compagnie do gens faisant profession
d'esprit ou de savoir, nul ne veut pris de soi un plus habile
quo soi, mais bien un plus noble, un plus riche : un duo
et pair honore I'Acadimie Fran(;aise, qui ne veut point de
Boileau,^ refuse la Bruyfere, fait atteudre Voltaire, mais
reyoit tout d'abord Chapelain et Conrart."
We have next to consider the influence of the French
Academy on the language and literature, a subject on which
the most opposite opinions have been advanced. On the
one hand, it has been asserted that it has corrected the
judgment, purified the taste, and formed the language of
French writers, and that to it we owe the most striking
characteristics of French literature, its purity, delicacy, and
flexibility. Thus Mr Matthew Arnold, in his well-known
Essay on the Literary Influence of Academies, has pro-
nounced a glowing panegyric on the French Academy as a
high court of letters, and rallying point for educated opinion,
as asserting the authority of a master in matters of tone
and taste. To it ho attributes in a great measure that
thoroughness, that openness of mind, that absence of
vulgarity which he finds everywhere in French literature ;
and to the want of a similar institution in England he
traces that eccentricity, that provincial spirit, that coarse-
ness, which, as he thinks, is barely compensated by English
genius. JTlius, too, M. Kendn, one of its most distinguished
living members, says that it is owing to the academy "qu'on
Lia Tension, the cirtlinal rem&rked, " Well, Monsieur, you will not
forgot the vfor^ pension in your dictionary.*' "No, Mouscignour,"
l*oplied Vaugelas, "and atill Icaa tho word gratitude."
^ Boiloau was eloctud to the French Academy 1G84, La Bruy^ro
iniaes.
peut tout dire Bans appareil scholastiqne avec la langue
des gens du monde." " Ah ne dites," he exclaims, " qu'Us
n'ont rien fait, ces obscures beaux esprits dont la vie se
passe h, instruire le proces des mots, ^'peser les syllables,
lis ont fait un chef-d'ceuvre — la langue franyaise." On the
other hand, its inherent defects have been so well ..ummed
up by M. Lanfrey, that we cannot do better than quote
from his recent History of Napoleon. " This institution,"
shown itself the enemy of despotism. Founded by the
monarchy and for the monarchy, eminently favourable to
the spirit of intrigue and favouritism, incapable of any
sustained or combined labour, a stranger to those great
works pursued in common which legitimise and glorify
the existence of scientific bodies, occupied exclusively with
learned trifles, fatal to emulation, which it pretends to
stimulate, by the compromises and calculations to which it
subjecto it, directed in everything by petty considerations,
and wasting all its energy in childish tournamentB, in
which tho flatteries that it showers on others are only tho
foretaste of the compliments it expects in return for itself,
founders the special mission to transform genius into be/
es]mt, and it would be hard to produce a man of talent
whom it has not demoralised. Drawn in spite of itself
towards politics, it alternately pursues and avoids them ;
but it is specially attracted by the gossip of politics, and
whenever it has so far emancipated itself as to go into
opposition, it does so as the champion of ancient prejudices,
li we examine its infiuenee ou the national genius, we
shaU see that it has given it a flexibility, a brilliancy, a
polish, which it never possessed before,; but it has dono
so at the expense of il-3 masculine qualities, its originality,
its spontaneity, its vigour, its natural grace. It has dis-
ciplined it, but it has emasculated, impoverished, and
rigidified it. It sees ia taste, not a sense of the beautiful,
but a certain type of correctness, an elegant form of medio-
crity. It has substituted pomp for grandeur, school
routine for individual inspiration, elaborateness for sim-
plicity, fadeur and the monotony of literary orthodoxy for
variety, the source and spring of intellectual life; and in
the works produced under its auspices we discover tho
rhetorician and the writer, never the man. By all its
ment of a monarchical society. Richelieu conceived and
created it as a sort of superior centralisation applied to
intellect, as a high literary court to maintain intellectual
unity, and protest against innovation. Bonaparte, aware of
all this, had thought of re-establishing its ancient privileges;
but it had in his eyes one fatal defect — esprit. Kings of
France could condone a witticism even against themselves,
a, parvenu could not."
In conclusion, we would briefly state our own opinion.
The influence of the French Academy has been conservative
rather than creative. While it has raised tho general
standard of willing, it has tended to hamper and crush
originality. It has done much by its example for stylo,
but its attempts to impose its laws ou language have, from
the nature of tho case, failed. For, however perfectly a
dictionary or a grammar may represent the existing lan-
guage of a nation, an original genius is certain to arise — a
Victor Hugo, or an Alfred de Musset, who will set at do-
fiance all dictionaries and academic rules.
its first meeting in July 171.3, in the palace of its founder,
the Duke d'Escalona. It consisted at first of 8 academicians,
including the duke; to which number H others were
afterwards added, the founder being chosen president or
director. In 1714 the king granted them the royal con-
firmation and protection. Their device is a crucible in
76
the middle of the fire, with this motto, Limpia, flxa, y
da esplmdo) — " It purifies, fixes, and gives brightness."
The number of its members tvas limited to 24; the Duke
d'Escalona was chosen director for life, but bis successors
were elected yearly, and the secretary for life. 'l^hcir
object, as marked out by the royal declaration, was to
cultivate and improve the national language. They were
to begin with choosing carefully such words and phrases
as have been used by the best Spanish writers ; noting
the low, barbarous, or obsolete ones ; and composing a
dictionary wherein these might be distinguished from the
former.
Sweden. — The Eoycd Swedith Academy was founded in
the year 1786, for the purpose of purifying and perfecting
the Swedish language. A medal is struck by its direction
every year in honour of some illustrious Swede. This
academy docs not publish its transactions.
Belgium. — Belgium has ahvays been famovui for its
literary societies. The little town of Dicst boa-sts that it
pcssessed a society of poets in 1 302( and the Catherimsts
of AJost date from 1107. Whether or hot there is any
foundation for these claims, it is certain that numerous
Chamhers of liheioric (so academics were then called)
existed in the first years of the rule of the house of Bur-
gundy.
The present Royal Academy of Belgium, was founded by
the. Count of Coblenzl at Briissels, 1769. Count Stahreu-
berg obtained for it in 1772 letters patent from Maria
Theresa, who also granted pensions to all the members,
and a fund for printing their works. All academicians
were ipso facto ennobled. It was reorganised, and a class
of fine arts added in' 1845 through the agency of M. Van
de Weyer, the learned Belgian ambassador at London. It
has devoted itself principally to national history and anti-
quities.
III. Academies of Aiich.sology and History. —
Italy. — Under this class the Academy of Hercnlaneum pro-
perly ranks. It was established at Naples about 1755, at
which period a museum was formed of the antiquities
fo",u!d at Herculaneum, Pompeii, and other places, by the
Marquis Tanucci, who was then minister of state. Its ob-
ject was to explain the paintings, &c., which were discovered
at those places; and for this purpose the members met
every fortnight, and at each meeting three paintings were
on them at their next sitting. The first volume of their
labours appeared in 1775, and they have been continued
under the title of Antichita di Ercolano. They contain
engravings of the principal paintings, statues, bronzes,
marble figures, medals, utensils, ic, with explanations.
In the year 1807, an Academy of History and Antiquities,
on a new plan, was established at Naples by Joseph Bona-
parte. The number of members was lunitecl to forty;
twenty of whom were to be appointed by the king, and
these twenty were to present to him, for his choice, thi'ee
names for each of those wanted to complete the fiiU num-
ber. Eight thousand ducats were to be annually allotted
for the current expenses, and two thousand for prices to
the authors of four works which should be deemed by the
aiademy most deserving of such a reward. A grand meet-
ing was to be held every year, when the prizes were to be
distributed, and analyses of the works read. The first
meeting took place on the 25th of April 1807; but the
subsequent changes in the political stats of Naples pre-
vented the full and permanent establishment of this insti-
tution. In the same year an academy was established at
Florence for the illustration of Tuscan antiquities, which
published some volumes of memoirs.
I'rancc. — The old Academy of Inscriptions and Belles
Lettret was an off-shoot from the Franch' Academy, which
then at least contained the UiU of French learrung. Loms
XIV. was of all French kings the one moat .occupied with
his own aggrandiijement. Literature, and even science, be
only encouraged so far as they redounded to hia own glbry.
Nor were literary men inclined to assert their independence.
Boileau well represented the spirit of the age when, in
dedicating hiii tragedy of Berenice to Colbert, he wrote —
" The least things become important if in any degree
they can seivo the glory and pleasure of the king." Thu«
it was that the Academy of Inscriptions arose. At the
suggestion of Colbert, a company (a committee we should
now call it) had been ap)X)iuted by the king, chosen from
the French 'Academy, charged with the o£Bce of fumishing
inscriptions, devices, aiid legends for medals. It consisted
of four academicians : Chapelain, then considered the poet
laureate of France, one of the authors of the critique on
the Cid (see above); I'abbd do Bourzais; Franfois Car-
pentier, an antiquary of high repute among his contom-
l/oraries ; and I'abbi de Capagnes, who owed his appoint-
ment more to the fulsome fiatterj' of his odes than his
reiUy learned translations of Cicero and Sallnst. This
company used to meet in Colbert's library in the winter,
at his country-house at Sceaux in the summer, generally
on Wednesdays, to serve the convenieiice of the minister,
who was constantly present. ITieir meetings were princi-
pally occupied with discussing the inscriptions, statues,
and pictures intended for the decoration of Versailles; but
M. Colbert, a really learned man and an enthusiastic col-
lector of manuscripts, was often pleased to converse with
them on matters of art, history, and antiquities. Their
first published work was a collection of engravings, accom-
panied by descriptions, designed for some of the tapestries
at Versailles. Louvois, who succeeded Colbert as a super-
intendent' of buildings, revived the company, which had
begun to relax its labours. F^libien, the learned architect,
and the two great poets Racine and Boileau, were added
to their number. A series of medals was commenced,
entitled Medailles de la Grande Bistoire, or, in other word^
the histoiy of le Grand Monarque.
But it was to M. de Portchartrain, comptroller-general
of finance and secretary of state, that the academy owed
its institution. He added to the company Kenaudot and
TourreO, both men of vast learning, the latter tutor to hia
son, and put at its head his nephew, I'abbe Bignon, librarian
to the king. By a new regulation, dated the 16th July
1701, the Eoyal Academy of InscriptioTis and MedaU
was instituted, "being composed of ten honorary members,
ten pensioners, ten associates, And ten pupUs. On ita
constitution We need not dwell, as it was an almost exact
copy of that of the Academy of Science. ■ Among the
regulations wo find the following, which indicates clearly
the transition from a staff' of learned officials to a learned
body : — " The academy shall concern itself with all that can
contribute to the perfection of inscriptions and legends, of
designs for such monuments and decorations as may ba
submitted to its judgment; also Avith the description of all
artistic works, present and future, and the historical ex-
planation of the subject of such works; and as the know-
ledge of Gr>eet and Latin antiquities, arid of these two
languages, is the best guarantee for success in labours of
this class, the academicians shall apply themselves to all
that this division of learning includes, as one of the .most
worthy objects of their pursuit."
Among the first honorary members we find the indefa-
tigable MabiUou (excluded from the pensioners by reason
of his orders), Piro La Chaise, the king^s confessor, and
Cardinal Rohan-; among the associates Fontenelle, and
Rollin, whose Ancient History was submitted to the
academy for revision. In 1 7 1 1 tnty completed L'Uistoirc
Metalli^ve du Hoi, of which Saint-Siinon was asked- to
T'J'
■writo the preface. In 1716 the regent changed its title
to that of the Academij of Inscriptions and Belles Leitres,
a title which better suited its new character.
In the great battle between the Ancients and the Modems
which divided the learned world in the first half of the
18th century, the Academy of Inscriptions naturally
espoused the cause of the Ancients, as the Academy of
Sciences did that of the Moderns. During the earlier
years of the French Revolution the academy continued
its labours uninterruptedly; and on the 22d of January
1793, the day after the death of Louis XVI., we find in
the Fi'oceedings that M. Brequigny read a paper on the
projects of -marriage between Queen Elizabeth and the
Dukes of Anjou and Alen9on. in the same year were
published the 45th and 46th vols, of the Memoires de
I' Acadimie. On the 2d of August of the same year the
last seance of the old academy was held. More fortunate
than its sister Academy of Sciences, it lost only three of its
members by the guillotine. One of these was the astro-
nomer Sylvain Bailly. Three others sat as members of
the Convention ; but for the honour of the academy, we
must add that all three were distinguished by their mode-
ration.
In the first araught of the new Institute, October 25,
1795, no class corresponded exactly to the old Academy
of Inscriptions ; but most of the members who survived
found themselves re-elected either in the 2d class of moral
and political science, under which history and geography
were included as sections, or more generally under the 3d
class of literature and fine arts, which embraced ancient
languages, antiquities, and monuments.
The Proceedings of the Society embijaco a vast field, and
are of very various merits. Perhaps the subject.; on which
it has shown most originality are comparative mythology,
the history of science among the ancients, and the geo-
graphy and antiquitijes of France. The old academy has
reckoned among its menvbers De Sacy the Orientalist,
Dansse de VUloison the philologist, Du Perron the traveller,
Saintc-Croix and Du Theil the antiquarians, and Le Beau,
who has been named the last of the Romans. The new
names of Chanqiolliou, A. Remusat, Raynouard, Burnouf,
and Augustin Thierry.
Celtic Academy. — In consequence of tire attention of
several literary men in Paris having been directed to Celtic
antiquities, a Celtic Academy was established in that city in
the year 1 800. Its objects were, first, the (jlucidation of the
history, customs, antiquities, manners, and monuments of
the Celts, particularly in France; secondly, ihe etymology
of all the European languages, by the aid of the Celto-
British, Welsh, and Erse ; and, thirdly, reL^earches relating to
Druidism. The attention of the members was also parti-
cularly called to the history and settlements of the Galata;
in Asia. Lenoir, the keeper of the museum of French
monuments, was appointed president. The academy still
exists as La SociSle Jioyale des Antiqnaires dc France.
IV. Academies op Medicine and Suegeky.- — Germany.
— The Academy of Naturae Curiosi, called also the Leo-
poldine Academy, was founded in 1062, by J. L. Bausch,
a physician of Leipsic, who, imitating the example of the
English, published a general invitation to medical men to
communicate all extraordinary cases that occlirred in the
course of their practice. The works of the Naturae Curiosi
were at first published separately ; but this being attended
with considerable inconvenience, a new arrangement was
formed, in 1770, for publishing a volume of observations
annually. From some cause, however, the first volume
did not make its aiipearance until 1784, when it came
'orth under the title of Ephemeridcs. In 1 687, the Emperor
Leopold took tne society under his protection, and estab'
lished it at Vierma; hence the title of Leopoldine which i'
ia consequence assumed. But though it thus acquired ;
name, it had no fixed place of meeting, and no regular
assemblies ; instead of which there was a kind of bureau
or office, first established at Breslau, and afterwards re-
moved to Nuremberg, where communications from corre-
spondents were received, and persons properly qualified
admitted as members. By its constitution the Leopoldine
and colleagues or members, without any limitation as tc
numbers. At their admission the last come under a two
fold obligation — first, to choose some subject for discussion
out of the animal, vegetable, or mineral kingdom, provided
it has not been previously treated of by any colleague of
the academy; and, secondly, to apply themselves to furnish
materials for the annual Epliemerides. Each member also
ing of a gold ring, whereon is represented a book open^
with an eye on one side, and on the other the academical
motto of Nunquam, otiosus.
The Academy of Surgery at Vienna was instituted by
the present emperor, under the direction of the celebrated
Brambella. In it there were at first only two professors ;
and to their charge the instruction of a hundred and thirty
young men was committed, thirty of whom had formerly
been surgeons in the army. But latterly the number both
of teachers and pupils was considerably increased. Gab-
rielli was appointed to teach pathology and practice ;
Boecking, anatomy, physiology, and physics; Streit, medica}
and pharmaceutical surgery; Hunczowsky, surgical ope-
rations, midwifery, and chirurgia forensis ; and Plenk,
chemistry and botany. To these was also added Beindel,
as prosecutor and extraordinary professor of surgery and
anatomy. Besides this, the emperor provided a large and
splendid edifice in Vienna, which affords accommodation
both for the teachers, the students, pregnant women,
patients for clinical lectures, and servants. For the use
of this academy the emperor also purchased a medical
libraiy, which is open every day ; a complete set of chirur-
gical instruments; an apparatus for experiments in natural
philosophy; a collection of natural history; a number of
anatomical and pathological preparations ; a collection of
preparations in wax, brought from Florence ; and a variety
of other useful articles. Adjoining the building there
is also a good botanical garden. With a view to encourage
emulation among the students of this institution, three
prize medals, each of the value of 40 florins, are annually
bestowed on those who return the best answers to questions
proposed the year before. These prizes, however, are not
entirely founded by the emperor, but are iik part owing to
the bbei-ality of Brendellius, formerly protochimrgus at
Vienna.
France. — lioyal Academij of Medicine. — Jledicino is a
science which has always engaged the atteution of the
kings of France. Charlemagne established a school of
medicine in the Louvre, and various societies have been
founded, and privileges granted to the faculty by his suc-
cessors. The Royal Academy of Medicine succeeded to the
old Pioyal Society of Medicine and the Academy of Sur-
gery. It was erected by a royal ordinance, dated December
20, 1820. It was divided into three sections — medicine,
surgery, and pharmacy. lu its constitution it closely
resembled the Academy of Sciences {vid. sup.) Its function
was to preserve or propagate vaccine matter, and answer
inquiries addressed to it by the Government on the subject
of epidemics, sanitary reform, and public health generally.
It has maintained an enormous correspondence, in all
quarters of the globe, and published extensive minutes.
V. Academies of the Fin? Akts. — Rua.a.- — Tltf
A C A D E :\1 Y
academy at St Petersburg was established by the Empress
Elizabeth, at the suggestion of Count Shuvaloff, and
annexed to the Academy of Sciences. The fund for its
support was X4000 per annum, and the foundation
admitted forty scholars. Catharine II. formed it into a
sep.imto institution, augmented the annual revenue to
£12,000, and increased the number of scholars to three
hundred ; she also constructed, for the use and accommo-
dation of the members, a large circular building, which
fronts the Neva. The scholars are admitted at the age of
•^ix, and continue until they have attained that of eighteen.
They are clothed, fed, and lodged at the expense of the
crown ; and arc all instructed in reading and writing,
arithmetic, the French and German languages, and draw-
ing. At the age of fourteen they are at liberty to choose
any of the following arts, di^nded into four classes, viz.,
first, painting in all its branches of history portraits, war-
pieces, and landscapes, architecture, mosaic, enamelling,
&c. ; secondly, engraving on copperplates, seal-cutting, &c. ;
thirdly, carving on wood, ivorj', and amber; io\irthly, watch-
making, turning, instrument making, casting statues in
bronze and other metals, imitating gems and medals in
paste and other compositions, gildirig, and varnishing.
Prizes are annually distributed to those who excel nn any
particular art ; and, from those who have obtained four
prizes, twelve are selected^ who are sent abroad at the
charge of the crown. A certain sum is paid to defray
their travelling e-Tpenses ; and when they are settled in
any town, they receive an annual salary of .£60, which is
continued during four years. There is a small assortmeut
of paintings for the use of the scholars ; and those who
have made great progress are permitted to copy the pictures
iu the imperial collection. For the purpose of design,
there are models in plaster, all done at Rome, of the best
antique statues in Italy, and of the same size with the
originals, which the artists of the academy were employed
to cast in bronze.
France. — The Academy of Painting and Sculpture at
Parii was founded by Louis XIV. in 1 G48, under the title of
Academic Royale des Beaux Arts, to which was afterwards
united the Academy of Architecture, erected 1671. The
academy is composed of painters, sculptors, architects,
engravers, and musical composers. From among the
members of the society, who are painters, is chosen the
director of the French Academic des Beaux Arts at Berne,
also instituted by Louis XIV. in 1677. The director's pro-
vince is to superintend the studies of the painters, sculptors,
i-c, who, having been chosen by competition, are sent to
Italy at the expense of the Government, to complete their
studies in that country. Jlost of the celebrated French
painters have begun their career in this way.
The Hoyal Academy of Music is the name which, by a
strange perversion of language, is given iu France to the
grand opera. In 1571 the poet Baif established in his
house an academy or school of music, at which ballets and
masquerades were given. In 1645 Mazarin brought from
Italy a troupe of actors, and established them in the Rue
du Petit Bourbon, where they executed Jules Strozzi's
" AchiUe in Scire," the first opera performed in France.
After Jloliire's death in 1673, his theatre in the Palais
P.oyal was given to Stdli, and there were performed all
Gluck's great operas ; there Vcstris d.inced, and there was
produced Jean Jacques Rousseau's " lievin du Village."
Italy. — In 177& an Academy of Painting and SciJp-
ture was established at Turin. The meetings were held
in the palace of the king, who distributed prizes among
the most successful members. In Milan an Academy of
Architecture was established so early as the year 13S0, by
Galeas ViscontL A'oout the middle of t'ne last century an
Academy of the Arts was established there, after the
example of those at Paris and Itome. Tho pupils were
furnished with originals and models, and prizes were dis-
tributed annually. The prize for painting was a gold
medal, and no prize was bestowed till all tho competing
pieces had been subjected to the examination and criticism
of competent judges. Before the effects of the French
Revolution reached Italy this was one of the best establish-
ments of the kind in that kingdom. In the hall of the
as several ancient paintings and statues of great merit, —
particularly a small bust of Vitellias, and a statue of
Agrippina, of most exquisite beauty, though it wants the
been long estabUshed at Florence, fell into decay, but was
restored in the end of last centur}-. In it there are halls
for nude and plaster figures, for the use of the sctJptor and
tho painter. The hall for plaster figures had modeb of all
the finest statues in Italy, arranged in two lines; but thf
treasures of this and the other institutions for the fine art*
were greatly diminished during the occupancy of Italy by
the Frenclu In the saloon of the Academy of the Arts at
Modena there are many casts of antique statues ; but after
being plundered by the French it dwindled into a petty
school for drawings from living models ; it contains the
skull of Correggio. There is also an Academy of the Fine
Arts in Mantua, and another at Venice.
ture, and Architecture, was founded by Philip V. Tho
minister for foreign affairs is president. Prizes are dis-
tributed every three j-ears. In Cadiz a few students
are supplied by Government with the means of drawing
and modelling from figures ; and such as are not able
to purchase the reqi^^ite instruments are provided with
them.
Sweden. — An Academy of the Fine Arts was founded at
Stockholm in the year 1733 by Count Tessin. In its hall
are the ancient figures of plaster presented by Lotiis XIV.
to Charles XI. The works of the students are publicly
exhibited, and prizes are distributed annually. Such of
them as display distinguished ability obtain pensions from
Government, to enable them to reside in Italy for some
years, for the purposes of investigation and improvement.
In tliis academy there are nine professors, and generally
about four hundred students. In the year 1705 an
Academy of Painting, Sculpture, and Architecture was
established at Vienna, with tho vie* of encouraging and
promoting the fine arts.
England. — The Jloyal Academy of ArU in London was
instituted for the encouragement of designing, painting,
sculpture, &c., in the year 1768, with Sir J. Re>-nolds
for its president. This academy is under the immediate
patronage of the queen, and under the direction of forty
artists of the first rank in their several professions. It
furnishes, in winter, living models of different characters
to draw after ; and in summer, models of the same kind
to paint after. Nine of the ablest academicians are
annually elected out of the forty, whose business it is to
attend by rotation, to set the figures, to examine the
performance of the students, and to give them necessary
instructions. There are like\\ise professors of painting,
sculpture, architecture, anatomy, and chemistry, who
annually read public lectures en the subjects of theii
several departments ; besides a president, a council, and
all students properly qualified to reap advantage from the
studies cultivated in it ; and there is an annual exhibition
at Burlington House of paintings, sculptures, and designs,
open to aU artists of distinguished merit.
The Academy of Ancient Music was established in Lon-
don in 1710, by several persons of distinction, and other
A C A — A C G
79
amateurs, in conjimction with the most eminent masters of
the time, with the view of promoting the study and practice'
of Tocal and instrumental harmony. This institution,
celebrated compositions, both foreign and domestic, in
manuscript and in print, and which was aided by the per-
formances of the gentlemen of the chapel royal, and the
choir of St Paul's, with the boys belonging to each, con-
tinued to flourish for many years. In 1731a charge of
plagiarism brought against Bononcini, a member of the
his own, threatened the existence of the institution. Dr
demy, took part with Bononcini, and withdrew from the
society, taking with him the boys of St Paul's. In 1734
Mr Gates, another member of the society, and master of
the children of the royal chapel, also retired in disgust;
so that the institution was thus deprived of the assistance
which the boys afforded it in singing the soprano parts.
From this time the academy became a seminary for the
instruction of youth in the principles of music and the
laws of harmony. Dr Pepusch, who was one of its foun-
ders, was active in accomplishing this measure; and by
the expedient. of educating boys for their purpose, and
admitting auditor members, the subsistence of the aca-
demy was continued. The Royal Academy of Music
was formed by tha principal nobility and gentry of the
kingdom, for iho performance of operas, composed by
Handel, and conducted by him at the theatre in tiie Hay-
market. The subscription amounted to X50,000, and the
king, besides subscribing XIOOO, allowed the society to
assume the title of li'jyal Academy. It consisted of a
governor, deputy-governor, and twenty directors. A con-
tost .between Handel and Senesino, one of the performers,
in which the directors took the part of the latter, occa-
with reputation for more than nine years. The present
Royal Academy of Music dates from 1822, and was incor-
porated in 1830 under the patronage of the queen. It
instructs pupOa of both sexes in music, charging 33 guineas
per annum; but many receive instruction free. It also
gives public concerts. In this institution the leading"
instrumentalists and vocalists of England have received
Rudall, Carte, and Co.)
Academy is a term also applied to those royal coUegiat •
seminaries in which young men are educated for the navj
and army. In our country there are three colleges of
this description — the Royal Naval CoDege at Portsmouth,
the Royal Military Academy at Woolwich, and the Royal
Military College, Sandhurst.
while it remained a French settlement.
ACALEPHvE (from o.KaXrj'fiv, a nettle), a name given to
the animals commonly known as jcily-fish, sea-Uubber,
Medusce, sea-nettles, &c.
ACANTHOCEPHALA (from ^KavBa, a thorn, and
Ke4>a\q, the head), a group of-parasitic worms, having the
heads armed with spines or hooks.
ACANTHOPTERYGII (from aKavBa, a thorn, and
Trripv^, a wing), an order of fishes, having bony skeletons
witl^ prickly spinous processes in the dorsal fins.
ACANTHUS, a genus of plants belonging to the natural
order Acanthaceae. The species are natives of the southern
parts of Europe. The most common species is the Acan-
thus mollis or Branhursine. It has large, deeply-cut, hairy,
shining leaves, which are supposed to have suggested the
decoration of the Corinthian column. Another species.
Acanthus spinosus, is so called from its spiny leaves.
ACAPULCO, a town and port in Mexico, on a bay of
the Pacific Ocean, about 190 miles S.S.W. of Mexico, in
N. kt. 16° 50', W. long. 99° 46'. The harbour, which is
the best on the Pacific coast, is almost completely land-
locked. It is easy of access, and the anchorage is so
secure that heavily-laden ships can lie close to the rocks
which surround it. The town lies N.W. of the harbour,
and is defended by the castle of San Diego, which stands
on an eminence. During a part of the dry season the air
is infected with the putrid cfHuvia of a morass eastward of
the town. This, together with the heat of the climate,
aggravated by the reflection of the sun's rays from the
granite rocks that environ the to^v^l, renders it very un-
healthy, especially to Europeans, though a passage cut
through the rocks, to let in the sea breeze, has tended to
improve its salubrity. Acapulco was in former times the
great depot of the trade of Spain with the East Indies.
A 'galleon sailed from this port to Manilla in the Philippine
Islands, and another returned once a year laden with the
treasures and luxuries of the East. On the arrival of this
galleon a great fair was held, to which merchants resorted
from all parts of lleiico. The tca.de between Acapulco
and Mamlla was annihilated when Mexico became inde-
pendent; and, from this cause, and also on account of tha
frequent earthquakes by which the town has been visited,
it had sunk to comparative insignificance, when the dis-
covery of gold in California gave its trade a fresh impetus.
It 13 now the most important seaport in Mexico, and is
regularly touched at by the Pacific mail steamers. Besides
having a large transit trade, it exports wool, skins, cocoa,
cochineal, and indigo; and the imports include cottons,
silks, and hardware. Population about 5000.
ACARNANIA, a province of ancient Greece, now called
Carnia. It was bounded on the N. by the Ambracian
gulf, on the N.E. by Amphilochia, on the W. and S.AV.
by the Ionian Sea, and on the E. by .(Etolia. It was
a hiUy country, with numerous lakes and tracts of rich
pasture, and its hiUs are to the present day crowned with
thick wood. It was celebrated for its" excellent breed of
horses. The Acarnanians, according to Mr Grote, though
admitted as Greeks to the Pan-Hellenic games, were more
akin in character and manners to their barbarian neighbours
of Epirus. Up to the time of the Peloponnesian war, they
are mentioned only as a race of rude shepherds, divided
into numerous petty tribes, and engaged in continual strife
and rapine. They were, however, favourably distinguished
from their jEtolian neighbours by the fidelity and stead-
fastness of their character. They were good soldiers, and
excelled as slingers. At the date above mentioned they
begin, as the allies of the Athenians, to make a more pro-
:mnent figure in the history of Greece. The chief toivn
was Stratos, and subsequently Leucas.
ACARUS (from iKopt, a mite), a genus of Arachnides,
represented by the cheese mite and other foims.
ACCELERATION is a term employed to denote gene-
rally the rate at which the velocity of a body, whoso
motion is not uniform, either incroascs or decreases. As
the velocity is continually changing, and cannot therefore
be estimated, aj in uniform motion, by the space actually
passed over in a certain time, its value at any instant haa
to be measured by the space the body would describe in
the unit of time, supposing that at aiul frora the instant ia
80
A C C — A C C
question tho motion became and continued uniform. If
tlio motion is such that the velocity, thus nifcasurcd, in-
creases or decreases by equal amounts in equal iuter»als of
time, it is said to bo uniformly accelerated or retarded.
In that Ciiso, if/ denote tho amount of increase or decrease
of velocity corresponding to tho unit of time, tho whole of
such increase or decrease in t units of time will evidently
bo ft, and therefore if « bo the initial and v tho final
velocity for that interval, ti — u ^fl, — the upper sign apply-
ing to accelerated, the lower to retarded, motion. To find
the distance or space, i, gone over in i units of time, let i
bo divided into n eaual intervals. Tho velocities at the
^ 2/
end of the succossive intervals will be u ± / - , « ■<=/ — ,
m
u ••■/ — , iKo. Let it now be supposed that during each
of those small intervals the body has moved uniformly
with its velocity at tho end of the interval, then (since a
body moving uniformly for x seconds with a velocity of y
feet per second will move through tsy feet) the epaces
describod in tho successive intervals would be the product
of tho velocities given above by - , and tho whole spaoo in
the time t would bo the sum of these spaces; i,s.,
« = j(-(l + 1 .... repeated n times) */• -j(l -I- 2 -H 3 +n)
II''
^ii ="->(..!).
It is evident, however, tuat as tho increase or decrease of
velocity takes place continuously, this sum will be too
large; but the greater n is taken, or (which is the same
thing) tho smaller the intervals are during which the
velocity is Bupposed to be uniform, tho nearer will tho
result be to the trutL Hence making n as largo as pos-
sible, or - as small as possible, i.e., — 0, we obtain as the
correct expression s = ut ± - /t'.
In the case of motion
0, and the above formulae become «=_/?,
from rest,
"We have a familiar instance of uniformly accelerated
and uniformly retarded motion in the case of bodies fall-
ing and rising vertically near the earth's surface, where, if
the resistance of tho air be neglected, the velocity of the
body is increased or diminished, in consequence of the
earth's attraction, by a uniform amount in each second of
time. To this amount is given the name of the accelera-
tion of gravity (usually denoted by the letter <?), the value
of which, in our latitudes and at the surface of the sea, is
very nearly 32J feet per second. Hence the space a body
falls from rest in any number of seconds is readily found
by multiplying IG-,', feet by the square of th« number of
seaonds. For a fuller account of accelerating force, — tx-
preased in the notation of the Differential Calculus by
/=■ ^ J- or/= !t —J, — the reader is referred to the article
Dynamics.
ACCENT, ill reading or spedking, is the stress or
pressure of tho voice upon a s^iaUe of a word. The deriva-
tion of the term (Lat. accerUus, quasi adcantus) clearly shows
that it was employed by the classical grammarians to
express the production of a musical effect. Its origin is
therefore to be sought in the natural desire of man to
graiify the ear by modulated sound, and probably no
lang;«ige exists in which it does not play a more or less
important part. " Only a machine," says Professor Blackie
( Place and Poioer of Accent in Language, in the Transac-
tions of the Roi/al Society of Edinbun/h, iS71), "could
produce a continnoos series of sounds in andistinguifihcd
monotonous repetitions like tlie tUm, tUm, turn, of a drum;
a rational being using words for a rational purpose tck
manifest his .thoughts and feelings, necessarily accents both
words and sentences in some way or other." That tha
accentuation of some languages is more distinct, various,
and effective than that of others is beyond question, but
there are none, so far as wo know, in wliich its power ia
not felt The statement sometimes made, that the French
have no accent in their words, can only mean that their
accent is less emphatic or less variously so than that
of certain other nations. If it means more, it is not
merely an error, but an absurdity. From this conception
of the subject, it is obvious that accent must be funda-
mentally the same thing in all languages, and must aim
more or less successfully at the same results, however
diverse the rules by which it is governed. But there are,
nevertheless, important differences between the conditions
under which accent operated in the cbssical, and those in
which it operates in modem tongues. It did not wholly
determine the rhythm, nor in tho least affect the metre of
classical verse ; it did not fix the quantity or length of
classical syllables. It was a mu.sical clement superadded
to the measured structure of prose and verse.
Passing over the consideration of the accentual system of
the Hebrews with the single remark, that it exhibits, thuugh
with more elaborate and complicated expression, most of
the characteristics both of Greek and English accent, we
find that the Greeks employed three gi-ammatical accents,
viz., the acute accent ('), which shows when the tone of the
voice is to be raised ; the grave accent ("), when it is to be
depressed ; and the circumflex accent {^), composed of both
the acute and the grave, and pointing out a kind of undula-
tion of the voice. Tho Latins have made the same use as the
Greeks of these three accents, and various modem nations,
French, English, ic., have also adopted them. As to the
Greek accents, now seen bott in manuscripts and printed
books, there has been great dispute about their antiquity
and use. But the following things seem to be undoubtedly
taught by the ancient grammarians and rhetoricians: — (1.)
That by accent (Trpoow&ia, toi'os) the Greeks understood^e
elevation or falling of the voice on a particular syllable
of a word, either absolutely, or in rektion to its position
in a sentence, accompanied with an intension or remisnon
of the vocal utterance on that syllable (cTriTao-t?, ay«rtt),
occasioning a marked predominance of that syllable over
the other syllables of the word. The predominance thus
given, however, had no effect whatever on the quantity
— long or short — of the accented syllable. The accented
syllable in Greek as in English, might be long or it might
be short ; elevation and emphasis of utterance being one
thing, and prolongation of tho vocal sound quite another
thiug, as any one acquainted with the first elements of
music will at once perceive. The difficulty wliich many
modern schokrs have experienced in conceiving how a
syllable could be accented and not lengthened, has arisen
partly from a complete want of distinct ideas on the nature
of the elements of which human speech is composed, and
partly also from a vicious practice which has long pre-
vailed in the English schoob, of reading Greek, not accord-
ing to the laws of its own accentuation, but according to
the accent of Latin handed down to us through the Roman
Catholic Church. For the rules of Latin accentuation are,
as Quinlilian and Cicero and the grammariiins expressly
mention, very different from the Greek; and the long syllable
of a word has the accent in Latin in a hundred cases, where
the musical habit of the Greek car placed it upon the short.
There is, besides, a vast number of words in Greek accented
on tho last sylhble (like volunteer, amhusca'de, in EngUsh),
of which not a single instance occurs in the Latin lau>
ACCENT
81
gtiage.. Partly, however, from ignorance, partly from care-
lessness, and partly perhaps fi;om stupidity, our scholars
tianaferre^i the pronunciation of the more popular learned
language to that which waa lesa known; and with the
help of time and constant usage, bo habituated themselves
to identify the accented with the long syllable, according
to the analogy of the Latio, that they began seriously
!io doubt the possibility of pronouncing otherwise. Eng-
lish scholars have long ceased to recognise its existence,
and persist in reading Greek as if the accentual marks
meant nothing at alL Even those who allow (liko Mr
W. G. Clark and Professor Munro) that ancient Greek
accent denoted an elevation of voice or tone, are still of
opinion that it is impossible to reproduce it in modern
times. " Here and there," says the former (Cambridge
Jaunud of Philology, vol. L 1868), "a person may be
found with such an exquisite ear, and such plastic organs
li speech, as to be able to reproduce the ancient distinction
between the length and tone of syllables accented and
unaccented, and many not so gifted may fancy that they
reproduce it when they do nothing of the kind. For the
mass of boys and men, pupils as well as teachers, the dis-
tinction is practically ioapossible." But, in spite of such
pessimist views, it may, on the whole, be safely asserted
that since the appearance of a more pldlosophicad spirit in
philology, under the guidance of Hermaim, Boeckh, and
other master-minds among the Germans, the best gram-
marians have come to recognise the importance of this
element of ancient Hellenic enunciation, while not & kvf
carry out their principles into a consistent practice. The
only circumstance, indeed, that prevents oiu' English
scholars from practically recognising the element of accent
in classical teaching, is the apprehension that this Would
interfere seriously with the practical inculcation of quantity ;
an apprehension in which they are certainly justiiied by
the practice of ohe modem Greeks, who have given such a
predominance to accent, as altogether to subordinate, and
in many cases completely overwhelm quantity; and who
also, in public token of this departure from the classical
habit of pronunciation, regularly compose their versos with
a reference to the spoken accent only, leaving the quantity
— as in modern language generally — altogether to the dis-
cretion of the poet. But, as experiment wiU teach any
one that there is no neoes.^ity whatever in the nature of
the human voice for this confusion of two essentially
different elements, it is not unlikely that English scholars
Greek prose at least systematically according to the Taws
of classical speech, as handed down to us by the gram-
marians of Alexandria and Byzantium. In the recitation
of classical verse, of course, as it was not constructed on
accentual principles, the skilful reader will naturally allow
the musical accent, or the emphasis of the rhythm to over-
bear, to a great extent, or altogether to overwhelm, the
accent of the individual word; though with regard to the
recitation of verse, it will always remain a problem how far
the ancients themselves did not achieve an " accentwum
eum quantitaie apta conciliatio," such as that which Her-
mann (De aneiulanda, ratione, dtc.) describes as the per-
fection of a polished classical enunciation. A historic
survey of the course of learned opinion on the subject of
accent, from the age of Erasmus down to the present day,
forms an interesting and important part of Professor
Blackie's essay quoted above. See Permington's work on
Greek Pronunciation, Cambridge, 1844; the German work
on Greek Accent by Qdttling (English), London, 1,831 ; and
Blackie's essay on the Place and Power of Accent, in the
^Transactions of the lioyal Society of Edinburgh, 1870-71.
If there is any perplexity regarcUng the nature or influ-
ence of classical accent, there Is none about English. /{
does not conflict e r combine with the modulations of quan-
tity. It is the sole determining element in our metrical
system. Almost the very earliest of our authors, the
Venerable Bede, notices^ this. In defining rhythm he
says — "It is a modulated composition of words, net
according to the laws of .metre, but adapted in the number
of its syllables to the judgment of the ear, as are tlie vers'
of omr vulvar poets" {Bede, Op, voL i. p. 57, ed. 1553}
We have, of course, long vowels and short, like the Greeks
and the Romans, but we do not regulate our verse by
them; and our mode of accentuation is sufficiently despotic
to occasionally almost change their character, so that a
long vowel shall seem short, and vice versa. In reality
this is not so. The long vowel remains long, but then ita
length gives it no privilege of place in a verse. It may
modify the enunciation, it may increase the roU of sound,
but a short vowel could take its place without a violation
of mstre. Take the word far, fov example; there the
vowel a ia long, yet in the line
" Moon, far-spooming Ocean Dowa to thep
it is not necessary that the a in far should be long; a
short vowel would do as well for metrical purposes, and
would even bring out more distinctlv the accentuation of
the syllable spoom.
Originally English accent was upon the root, and not
upon inflectional syllables. Qottling finds the same prin-
ciple operating in Greek, but in that language it certainly
never exercised the \iniversal sway it does in the earlier
forms of English. In the following passage from Beowulf,
the oldest monument of English literature, belonging, in its
first form, to a period even anterior to the invasion of
Britain by the Angles and Saxons, we shall put the
accented or emphatic syllables in italics: —
Strdet waes sid/n-fah . . The street was of variegated stoof^
stig wisode the path directed
gumam aet-gaedexe . . the men together ;
yiid-'hyiue scan .... the war-coiselet shon
heard, hand-looen . . . hard, hand-locked ;
hring-iien scir .... the ring-iron bright
s<mg m sea/rvfum . . . sang in their trappings,
p4 hie ti5 »«Ze fuidura . when they to the half forward
m hyra gr^rt-geatwum . in their terrible armour
gaTtgaji. owomon . , . came to go.
It will be observed that in these verses the accent (not to
be confounded with the mark which is used in Anglo-Saxon
to show that the vowel over which it is placed is long) is
invariably on a monosyllable, or on the root part of a
word of more than one syllable. The passage is also a
good illustration of what has previously been stated, that
the metre or rhythm in English is determined not by the
vowel-quantity of a syllable, but by the stress of the voice
on particular syllables, whether the vowels are long or
short. In the older forms of English verse the accent It.
somewhat irregular; or, to put it more accurately, the
number of syllables intervening between the recurrent
accents is not definitely fixed. Sometimes two or more'
intervene, sometimes none at all. Take, for example, the
opening lines of Langland's poem, entitled the Vision of
Piers the Ploiimian: —
" In a 5omer scson
Whan Boft was the Sonne,
I sAflpe me in shroudca.
As I a sJupe were, *
In habit as an Aeremite
UnAoly of workea.
Went unde in this world
lyonias to here.
Ac on a May vwrnyn^c
On Malaeme huUes,
Me by/rf a/crly,
Of /airy, mo thoaghtc ;
I W.-1S wery {orwandni,
And wcxt me to rjste
Under a brode hanke
By a homes aide.
And as I luy (tnd Iffnci^
And lokei in the waters,
I sfonibrcd in a slepyng,
It sacyuei so meija."
But no matter how irregular the time elapsing between the
T. — II
82
ACCENT
recurrence of the accents they are always on the root-
syllables.
Tbu Norman Conquest, however, introduced a different
Bysteci, which gradually modified the rigid uniformity of
the native English accentuation. The change 19 visible as
early as the end of the 12th century. By the middle of
the 14 th, that is to say, in tlio age of Chaucer, it h in full
operation. Its origin is thus explained by Mr Marsh, in
his Origin and Uislory of the £n{/lis/i Language (Lond.,
18G2) : — " The vocabularj- of the French language is de-
rived, to a great extent, from Latin words deprived of their
terminal inflections. The French adjectives mortal and
fatal are formed from the Latin mortalis and faialu, by
dropping tlie inflected syllable; the French nouns nation
and condition from the Latin accusatives nationem, condi-
iioncm, by rejecting the em final In most cases, the last
syllable retained in the French derivatives was prosodically
long in the Latin original ; and either because it was also
accented, or because the slight accent which is perceivable
in the French articulation represents temporal length, the
stress of the voice was laid on the final syllable of all these
words. 'When we borrowed such words froffi the French
we took them with their native accentuation ; and as ac-
cent is much stronger in English than in French, the final
syllable was doubtless more forcibly enunciated in the
former thau in the latter language." The new mode of ac-
centuation soon began to affect even words of pure English
origin — e.g., in Robert of Gloucester we find falsA«fe instead
of u'iiliche, begynny«(/ instead of bcgj/nnyng, endyng in-
stead of eht/yng. In the Proverbs of Hendyng we have no-
thyng for no(/ang, habitvj for Aatben, fomon for/omon ; in
Jiobert of Bninne, haiydom for halydom, c\othyng for clot/t-
ing, gietand for gretand. Chaucer furnishes numerous in-
stances of the same foreign influence revolutionising the
native accent ; hedom forfredora, hethenewe for hethenesse,
worthiness for wo/-(/i inesse, lowly for lowly, vrynnynge for
U'yn7iyBge, weddynge for weddynge, comynge for comynge ;
and it is traceable even in Spenser. On the other hand,
a contrary tendency must not be overlooked. We see an
effort, probably unconscious, to compel words of French
origin to submit to the rule of English accentuation. It is
noticeable in the century before Chaucer : in Chaucer him-
self it begins to work strongly ; mortal becomes mortal ;
\^mpest, tempest; snhstante, suistance ; amyable, amyMe ;
morsel, morsel; service, servise ; duchfjsf, diichesae ; cosyn,-
cosyn, <fcc. ; while a multitude of words oscillate between
the rival modes of accentuation, now following the French
and now the English. Before and during the Elizabethan
period, the latter began to prove the stronger, and for the
last 300 years it may be said to have, for the most part.
Anglicised the accent and the nature of the foreign additions
to our vocabulary. Nevertheless, many French words stiU
retain their own accent. Morris {Historical Outlines of
English Accidence, p. 75) thus classifies these : —
*' (1.) Nouns in -ade, -icr {-«r), -e', -«e, or -oon, -ine, {-in), as cas-
kc. {in conformity with these we say harpooneer^, mountaineer',) ;
le'jatee', payec^, &c. ; balloon', cartoon', &c ; chagrin', violin', ic. ;
routing, marine', &c.
"Also the follow-in^ words :—iw<fe(', bruneltc^, gaseUtf, cravat",
canal', control', gazelle ,. amateur', fatigued, antique', police', &c
bust, ke^; (6) in -ose, as morose^, verbose', kc ; (c) -esqiu, as bur-
lesjue , grotesque', ic
"(3.) Some verbs, as laptiz/f, cajoW, cares^, carouse, chastise',
escape', esteem', &c"
To these may be added the Greek and Latin words
which have been introduced into English for scientific and
other learned purposes, and which, not having been altered
in form, retain their original accentuation — as auro'ra,
coro'na, colot'svt, idea, hypoth'eiis, eauu'ra, dice'resit, diag-
no'tit, diluvium, diplo'ma, effluvium, ilyt'ium, <L'c. ; besides
the still larger number that have suffered a slight modifi-
cation of form, but no change cf accent, as dialectic, diag-
nos'tic, ejjlores'cent, elliptic, emer'sion, emol'lient, kc. The
Italian contributions to our tongue retain their original
accent when the form is untouched, as mulatto, tona'ta, vol-
ca'no, but lose it when the form is shortened, as Lan'dii
(It. handi'to).
A change in the position of the accent serves a variety
of purposes in EnglisL It distinguishes (1.) a noun from
a verb, as ac'ceut, accent'; augment, augment'; torment,
torment'; com'ment, comment'; con'sort, consort'; con'tcst,
contest'; con'trast, contrast'; di'gest, digest'; dis'count, dis-
count'; in'sult, insult', &c. ; (2.) an adjective iTom. n verb,
as ab'sent, absent'; fre'quent, frequent'; pre'sent, present';
com'pound, compound', &c ; (3.) an adjective from a noun,
as cx'pert, expert'; com'pact, compact'. It also denotes a
difference of meaning, e.g., con 'jure, conjure'; in'cense,
incense'; au'gust, august'; su'pine, supine'.
Accent has exercised a powerful influence in changing
the/orTHj of words. The unaccented syllables in tho
course of time frequently dropped off. This process was
necessarily more rapid and thorough in English than in
many other languages which were not subjected to equal
strain. The Norman Conquest made havoc of the English
tongue for a time. It was expelled from the court, the
schools, the church, and the tribunals of justice ; it ceased
to be spoken by priests, la^v)•er3, and nobles ; its only
guardians were churls, ignorant, illiterate, indifferent to
grammar, and careless of diction. VTho can wonder if,
in circumstances like these, it suffered disastrous eclipse 1
The latter part of the Anglo-Saxon Chronicle furnishes
melancholy evidence of the chaos into which it had fallen,
jet out of this chaos it rose again into newness of life,
reforming and re-accenting its half-mined vocabulary, and
drawing from the very agent of its destruction the elements
of a richer and more plastic expression. For it cannot bo
doubted that the irregularities now existing in English
accent, though perplexing to a foreigner, copiously vary
the modulation, and so increase the flexibility and power
of the language. The older forms of EngUsh, those in use
before the Conquest, and down to the period of Chaucer,
are stiff, monotonous, and unmusical A hard strength is
in the verse, but no liquid sweetness or nimble grace.
Now, it is possible, in spite of our. deficiency in vowel
endings, to produce the noblest melody in accent words
known to the modern world. Almost every kind of metre,
swift or slow, airy or majestic, has been successfully
attempted since the age of the Canterbury Tales. AVhen
we compare the drone of Caedmon with the aerial melody
of the Skylark, the Cloud, and the Areihusa of Shelley,
we see what an infinite progress has been made by
the development of accent in the rhythm of our native
tongue.
See Lectures on the English Language, by G. P. Marsh
(Lond. 1861); the Origin and History of the English
language, ic, by G. P. Marsh (Lond. 1862) ; Hi.'^torisclit
Grammatik der Englische Sprache, von. C. Friedrich Koch
a863-69); The English Language, by R. G. Latham
(1855); Philological Essays, hy the Rev. Richard Gamett
(Lond. 1853); On Early English Pronunciation, uith
especial reference to Shaispere and Chaucer, by A. J. Ellis
(Lond. 1SG7-71) ; Historical Outlines of English Accidence,
by Dr R. Morris (Lond. 1872). (j. M. E.)
ACCEPTANCE is the act by which a person binds
himself to comply with the request contained in a bill of
exchange addressed to him by the drawer. IiJ all cases it
is understood to be a promise to pay the bill in money, the
law not recognising an acceptance in which the promise is
A C — A C C
83
to pay in some otJ»er way, as, for example, partly in money
and partly by another biU. Acceptance may be absolute,
conditional, or partial Absolute acceptance is an engage-
ment to pay the bill strictly according to its tenor, and is
made by the drawee subscribing his name, with or without
the word " accepted," at the bottom of the bUl, or across
the face of it Conditional acceptance is a promise to pay
on a contingency occurring, as, for example, on the sale of
■jertain goods consigned by the drawer to the acceptor. No
contingency is allowed to be mentioned in the body of the
bUl, but a contingent acceptance is ciuite legal, and equally
binding with an absolute acceptance upon the acceptor
when the contingency has occurred. Partial acceptance is
where the promise is to pay only part of the sum mentioned
in the bUl, or to pay at a different time or place from
those specified. In all cases acceptance involves the
signature of the acceptor either by himself or by some
person duly authorised on his behalf. A biU can be
accepted in the first instance only by the person or persons
to whom it is addressed ; bpt if he or they faU to do so, it
may, after being protested for non-acceptance, be accepted
by another " supra protest," for the sake of the honour of
one or more of the parties concerned in it
ACCESSION is applied, in a historical or constitutional
sense, to the coming to the throne of a dynasty or line of
sovereigns, as the accession of the House of Hanover. The
corresponding term, when a single sovereign is spoken of,
is " succession." In law, accession is a method of acquiring
property, by which, in things that have a close connection with
or dependence on one another, the property of the principal
draws after it the property of the accessory, according to the
principle, accessio cedet principali, or accessorlum sequitur
principale. Thus, the owner of a cow becomes likewise the
owner of the calf, and a landowner becomes proprietor of
what is added to his estate by alluvion. Accession produced
by the art or industry of man has been called industrial
accession, and- may be by specification, as when wine is made
cut of grapes, or by confusion or commixture. Accession
sometimes likewise signifies consent or acquiescence. ' Thus,
in the bankrupt law of Scotland, when there is a settlement
by a trust-deed, it is accepted on the part of each creditor
by a deed of accession.
ACCKSSORY, a person guilty of a felonious offence,
not as principal, but by participation ; as by advice, command,
aid, or concealment. In treason, accessories are excluded,
every individual concerned being considered as a principal
In crimes under the degree of felony, also, all persons
concerned, if guilty at all, are regarded as principals. (See
24 and 25 Vict. c. 94. s. 8.) There are two kinds of
accessories — before the fact, and after it. The first is he
who commands or procures another to commit felony, and
is not present himself ; for if he be present, he is a principal
The second is he who receives, assists, or comforts any
man that has done murder or felony, whereof he has
knowledge. An accessory before the fact is liable to th "
same punishment as the principal ; and there is now indeed
no practical difference between such an accessory and a
principal in regard either to indictment, trial, or punishment
{24 and 25 Vict. c. 94). Accessories after the fact are in
general punishable with imprisonment for a period not
exceeding two years {ih. s. 4) The law of (Scotland makes
no distinction between the accessory to any crime (called
art and part) and the principal Except in the case of
treason, accession after the fact is not noticed by the
law of Scotland, unless as an element of evidence to prove
previous accession.
ACCL4 JUOLI, DoNATO, was born at Florence in 1428.
He was famous for his learning, especially in Greek and
mathematics, and for his scriices to his native state.
Having previously been intrusted with several important
embassies, he became Gonfalonier of Florence in 1473. He
died at Milan in 1478, when on his way to Paris to ask the
aid of Louis XI. on behalf of the Florentines against Pope
Sixtus IV. His body was taken back to Florence, and
buried in the church of the Carthusians at the public
expense, and his daughters were portioned by his fellow-
citizens, the fortune he left being, owing to his probity and
disinterestedness, very small He wrote a Latin translar
tion of some of Plutarch's Lives (Florence, 1478); Com-
mentaries on Aristotle's Ethics and Politico ; and the livea
of Hannibal, Scipio, and Charlemagne. In the work on
Aristotle he had the co-operation of his master Argyropylus.
ACCIDENT. An attribute. of a thing or class of things,
which neither belongs to, nor is in any way deducible from,
the essence of that thing or class, is termed its accident.
An accident may be either inseparable or separable : the
former, when we can conceive it to be absent from that
with which it is found, although it is always, as far as we
know, present, i.e., when it is not necessarily but is uni-
versally present ; the latter, when it is neither necessarily
nor universaDy present. It is often difficult to determine
whether a particular attribute is essential or accidental to the
object we are investigating, subsequent research frequently
proving that what we have described as accidental ought to
be classed as essential, and vice versa Practically, and
for the time being, an attribute, which neither directly nor
indirectly forms part of the signification of the term~ used
to designate the object, may be considered an accident ;
and many philosophers look upon this as the only intelligible
ground for the distinction. Propositions expressing the
relation between a thing or class and an accident, and also
between a thing or class and its property (i.e., something
deducible from, but not strictly forming part of, its essence),
are variously styled "accidental," "synthetical," "real,"
"ampUative," in contradistinction to "essential," "analy-
tical," "verbal," and "explicative" propositions. The
former give us information that we could not have dis-
covered from an analysis of the subject notion — e.y., "man
is found in New Zealand ;" the latter merely state what we
already know, if we understand the meaning of the language
employed, e.g., "man is rational."
ACCIUS, a poet of the 16th century, to whom is
attributed A Paraphrase of .^sop's Fables, of which Julius
Scaliger speaks with great praise.
ACCIUS (or Attius), Lucius, a Latin tragic poet, was
the son of a freedman, born, according to St Jerome, in
the year of Rome 583, though this appears somewhat
uncertain. He made himself known before the death of
Pacuvius by a dramatic piece, which he exhibited the same
year that Pacuvius brought one on the stage, the latter being
then eighty years of age, and Accius only thirty. We do
not know the name of this piece of Accius's, but the titles
of several of his tragedies are mentioned by various authors.
He wrote on the most celebrated stories which had been
represented on the Athenian stage ; but he did not always
take his subject from Grecian story ; for he composed at
least one dramatic piece wholly Roman, entitled £ridus,
and referring to the expulsion of the Tarquins. Only
fragments of his tragedies remain. He did not confine
himself to dramatic writing, having left other productions,
particularly his Annals, mentioned by Macrobius, Priscian,
Festus, and Nonnius Marcellus. H« ha.s been censured
for the harshness of his stylo, but in other 'icspccts he has
been esteemed a gi'eat poet. He died at an advanced age ;
and Cicero, who evidently attaches considerable weight to
his opinions, speaks of having conversed with Lim in his
youtL
ACCLAMATION, the exi'ression of the opinion, favour-
able or unfavourable, of any assembly by means of the
voice. Applause denotes strictly a similar e.\'pression by
84
A C C — A C C
clapping of hands, hut this diatincHon in tlio usage of tho
'words is by no means uniformly maintained. Among tho
Romans acclamation was varied both in form and purpose.
At marriages it was usual for tho spectators to shoat lo
Jlymen, Hymencee, or Talassio ; a Wctorious army or general
was greeted with lo tnumpke ; ii the theatre acclamation
was called for at the close of the play by the last actor,
who said, J'laudiie ; in the senate opinions were expressed
and votes pa.ssed by acclamation in such forms as Omnea,
omnes, ^guum est, Justum est, ifec ; and the praises cf tho
emperor were celebrated in certi'in pre-arranged sentences,
which seem to havo been chanted by tho whole body of
senators. The acclamations wliich authors and poets who
recited their works in public received were at first spon-
taneous and genuine, but in time became very largely
mercenary, it being customary for men of fortune who
affected literary tastes to keep applauders in their service
and lend them to their friends. When Nero performed in
the theatre his praUes were chanted, at a given signal, by
five thousand soldiers, who were called Aiu/uslals. The
wholo was conducted by a music-master, mesochonu or
the recollection of the French poet Dorat, may be said to
have originated the well-known Paris claque. Buying up
a number of the tickets for a performance of one of his
plays, he distributed them gratuitou.sly to those who pro-
mised to express approbation. From that time the claque,
or organised body of professional applauders, has been a
recognised institution in connection with the theatres of
Paris. In the early ages of the Christian church it was by
no means uncommon for an audience to express their appro-
l)alion cf a favourite preacher during the course of his
Bermon. Chrysostom especially was very frequently inter-
rupted both by applause and by acclamations. In eccle-
siastical councils vote by acclamation is very common, the
question being usually put in the form, placet or non placet.
This differs from the acclamation with which in other
aiiscmblies a motion is said to be carried, when, no amend-
ment being proposed, approval is expressed by shouting
Kuch words as ./(ye or Agreed.
ACGLISIATISATION is the process of adaptation by
wliich animals and plants are gradually rendered capable
of .surviving and flourishing in countries remote from their
original habitats, or under meteorological conditions dif-
ferent from those which they have usually to endure, and
which are at first injurious to them.
Tho subject of acclimatisation is very little understood,
and some writers have even denied that it can ever take
place. It is often confoimded with domestication or with
naturalisation ; but these are both very different pheno-
mena. A domesticated animal or a cultivated plant need not
liecessarily be acclimatised ; that is, it need not be capable
of enduring the severity of the seasons without protection.
The canary bird is domesticated but not acclimatised, and
many of our most extensively cultivated plants are in the
same category. A naturalised animal or plant, on tho
other hand, must be able to withstand all the vicissitudes
cf the seasons in its new home, and it may therefore be
thought that it must have become acclimatised. But in
many, perhaps most cases of naturalisation, there is no
were at first injurious, and this is essential to the idea of
acclimatisation. On the contrary, many species, in a new
country and under somewhat different climatic coi.ditions,
seem to find a more congenial abode than in their native land,
and at once flourish and increase in it to such an extent as
oftentoexterminatethe indigenous inhabitants. ThusAgassiz
(in his work on Lake Supenor) tells us that the road-side
weeds oi.the north-eastern United States, to the number of
130 species, are all European, the native weeds having dis-
appeared westwards; wbik- in New Zealand there are,
according to Mr T. Kirk ( Tratuactiont of the /fete Zealand
/nsliiute, ToL iL p. 131), no less than 250 species of
naturalised plants, more than 100 of which spread widely
over tho country, and often displace tho nativo vegetation.
Among animah, the European rat, goat, and pig, are
naturalised in New Zealand, where they multiply to such
an extent as to injure and probably exterminate many
native productions. In neither of these cases is there
any indication that acclimatitation was necessary or ever
took place.
On the other hand, the fact that an animal or plant
cannot be naturalised is no proof that it is not acclimatised.
It has been sho^vn by Mr Darwin that, in the case of m6st
animals and plants in a state of nature, the competition of
other organisms is a far more efficient agency in limiting
their distribution than the mere influence of climate. We
havo a proof of this in the fact that so few, comparatively,
of our perfectly hardy garden plants ever run wild; and
even the most persevering attempts to naturalise them
usually fail. Alphonse de CandoUe (Geographic liotaniqut,
p. 798) informs us that several botanists of Paris, Geneva,
and especially of Montpellier, have sown the seeds of many
hundreds of species of exotic hardy plants, in what appeared
to be the most favourable situations, but that in hardly
a single case has any one of them become naturalised.
Attempts have also been made to naturalise continental
insects in this country, in places where the proper food-
plants abound and the conditions seem generally favour-
able, but in no case do they seem to have succeeded
Even a plant like the potato, so largely cultivated and so
perfectly hardy, has not established itself in a wild state
in any part of Europe.
Different Degrees of Climatal Adaptation in Animali and
Plants. — Plants differ greatly from animals in the closeness
of their adaptation to meteorological conditions. Not only
will most tropical plants refuse to live in a temperate
climate, but many species are seriously injured by removal
a few degrees of latitude beyond their natural limits. This
is probably due to the fact, established by the experiments
of M. Becquerel, that plants pcssess no proper temperature,
but are wholly dependent on that of the surrounding
medium.
Animals, especially the higher forms, are much less
sensitive to change of temperature, as shown by the exten-
sive range from north to south of many specie.'. Thus,
the tiger ranges from the equator to northern Asia as far
as the river Amour, and to the isothermal of 32° Fahr. The
mountaia sparrow [Passer montana) is abundant in Java
and Singapore in a uniform equatorial climate, and abo
inhabits this country and a considerable portion of northern
Europe. It is true that most terrestrial animals are
restricted to countries not possessing a great range of
temperature or very diversified climates, but there is reason
to believe that this is due to quite a different set of causes,
such as the presence of enemies or deficiency of appropriate
food. When supplied with food and partially protected
from enemies, they often show a wonderful capacity of
enduring climates very different from that in which they
originally flourished. Thus, the horse and the domestic
fowl, both natives of very warm countries, flourish without
special protection in almost every inhabited portion of the-
globe. The parrot tribe form one of the most pre-eminently
tropical groups of birds, only a few species extending into
the warmer temperate regions ; yet even tho most exclu-
sively tropical genera are by no means delicate birds as
regards climate. In the Annals and Magazine of Natural
History iox 18G8 (p. 381) is a most interesting accotmt, by
Mr Charles Buxton, M.P., of the naturalisation af parrots
at Northreps Hall, Norfolk. A considerable number oL
A C C L I ]\i A T 1 S A T 1 O N
85
4.frican and Amazonian parrots, Bengal parroquets, four
ipecies of vihiie and rose crested cockatoos, and two speciKS
of crimson lories, have been at large for many years.
Several of these birds have bred, and they almost all live
in the woods the whole year through, refusing to take
shelter in a house constructed for tlieir use. Even when
the thermometer fell 6° below zero, all appeared in good
S-pirits and vigorous health. Some of these, birds have
lived thu.s exposed for nearly twenty, years, enduring our
cola easterly winds, rain, hail, and snow, all through the
winter, — a marvellous contrast to the equable equatorial
temperature (hardly ever less than 70'') which many of them
had been accustomed to for the first year or vears of their
?xisteiice.
Mr Jenner Weir records somewhat similar facts in the
Zoolojist for 1865 (p. 9411). He keeps many small birds
in an open aviary in his garden at Blackheath, and among
these are the Java rice bird {Padda oryzivora), two West
Airican weaver birds (tlyplumtoniis textor and Uuplectes
mnguinirostris), and the blue bird of the southern United
States (Spiui cyanea). These denizens of the tropics prove
quite as hardy as our native birds, having hved during
the severest winters yithout the slightest protection
against the cold, even when their drinking wat^r had to be
repeatedly melted.
Hardly any group of Mammalia ia more exclusively
tropical than the Quadrnmana, yet there is reason to believe
that, if other conditions are favourable, some of them can
withstand a considerable degree of cold. Ihe Semnopithecus
seJiistaceus was found by Captain Hutton at an elevation of
11,000 feet in the Himalayas, leaping actively among fir-
trees whose branches were laden vnXh. snow-T\Teaths. In
Abyssinia a troop of dog-faced baboons were observed by
Mr Blandford at 9000 feet above the sea. We may there-
fore conclude that the restriction of the monkey tribe to
(vam latitudes is probably determined by other causes than
tempi'iature alone.
Similar indications are given by the fact of closely allied
species inhabiting very extreme climates. The recently
extinct Siberian mammoth and woolly rhinoceros were
closely allied to species now inhabiting tropical regions
exclusively. Wolves and foxes are found alike in the
coldest and hottest parts of the earth, as are closely allied
species of falcons, owls, sparrows, and numerous genera of
A consideration of these and many analogous facts might
induce us to suppose that, among the higher animals at
least, there is little constitutional adaptation to climate,
and that in their case acclimatisation is not required. But
there are numerous examples of domestic animals which
sh'jw that such adaptation docs exist in other cases. The
yak of Thibet cannot long survive in the plains of India,
or even on the hills below a certain altitude ; and that this
is due to climate, and not to the increased density of the
atmosphere, is shown by the fact that the same animal
appears to thrive well in Europe, and even breeds there
readily. The Newfoundland dog ■wOl not live in India, and
the Spanish breed of fowls in this country suifer more
from frost than most others. When we get lower in the
r'ale the adaptation is often more marked. Snakes, which
are so abundant in waPtn countries, dinainish rapidly as
we go north, and wholly cease at lat. G2°. Most insects are
also very susceptible to cold, and seem to be adapted to
very narrow limits of temperature.
From the foregoing facts and observations we may con-
clude, firstly, that some plants and many animals are not
constitutionally adapted to the climate of their native
country only, but are capable of endurmg and flourishing
under a more or less extensive range of temperature and
other climatic conditions ; and, secondly, that most plants
and flome animals are, more or less closely, adapted to
climates similar to those of ihcu- native habitats. In order
to domesticate or naturalise the former class ia countries
not extremely differing from that from ^vhich the species
was brought, it will not bo necessary to acclimatise, in
the strict sense of the word. In the case of the latter
olass, however, acclimatisation is a necessary preliminary
to naturalisation, and in many cases to useful domestica-
tion, and we have therefore to inquije whether it is
possible.
Acclimatisation hy Individual Adajjiaiion. — It is evi-
dent that acclimatisation may occur (if it occurs at all) in
two ways, either/ by modifying the constitution • of tha
individual subnij?ted to the new conditions, or by the
production of offspring which may be better adapted to
those conditions than their parents. The alteration of the
constitution of individuals in this direction is not easy to
detect, and its possibility has been denied by many writers.
Mr Darwin believes, however, that there are indications
that it occasionally occurs in plants, where it can be best
observed, owing to the circumstance that so many plants
are propagated by cuttings or buds, which really continue
the existence of the same individual almost indefinitely.
He .adduces the example of vines taken to the West Indies
from Madeira, which have been found to succeed better
than those taken directly from France. But in most cases
habit, however prolonged, appears to have little effect on
the constitution of the individual, and the fact has no
doubt led to the opinion that acchmatisation is impossible.'
There is indeed little or no evidence to show that anj
animal to which a new cUmate is at first prejudicial can
be so acclimatised by habit that, after subjection to it for .i
few or many seasons, it may live as healthily and with as
little care as in its native country ; yet we may, on general
principles, believe that urider proper conditions such accli^
matisatiou would take place. In his Principles of Biologj^
(chap, v.), Mr Herbert Spencer his shown that every organ
and every function of living beings undergoes modificatioa
to a limited extent under the stimulus of any new con-
ditions, and that the modification is almost always such as
to produce an adaptation to those conditions. We may feel
pretty sure, therefore, that if robust and healthy individuals
are chosen for the experiment, and if the change they are
subjected to is not too great, a real individual adaptation
to the new conditions — that is, a more or less complete
acclimatisation — niU be brought about If now animals
thus modified are bred from, we know that their descendants
will inherit the modification. They ■naU thus start more
favourably, and being subject to the influence of the same
or a slightly more extreme climate during their whole hves,
the acclimatisation wiU be carried a step further; and
there seems no reason to doubt that, by this process alone,
if cautiously and patiently carried out, most animals whrch
breed freely in confinement could in time be acclimatised
in alihost any inhabited country. There is, however, a
much more potent agent, which renders the process of
Acclimatisation hy Variation. — A mass oicHdence exists
showing that variations of every conceivable kind occur
among the offspring of all plants and animals, and that, in
particular, constitutional variations are by no means un-
common. Among cultivated plants, for example, hardier
and more tender varieties often arise. The following cases
are given by Mr Darwin : — Among the numerous fniit-trees
raised in North America, some are well adapted to the
climate of the Northern States and Canada, whilo others
only succeed well in the Southern States. Adaptation oi
this kind is sometimes very close, so that, for e.xample, few
English varieties of wheat will thrive, in Scotland. Seed-
wheat from India produced a miserable crop when planted
86
ACCLIjMATISATION
by tho Ror. M. J. Berkeley on land which would have
produced a good crop of English wheat. Conversely,
French wheat taVon to the West Indies produced only
barren spikes, wliile native wheat by its side jielded an
enormous harvest. Tobacco in Sweden, raised from home-
grown seed, ripens its seeds a month earlier than plants
grown from foreign seed. In Italy, as long as orange
trees were propagated by grafts, they were tender; but
after many of the trees were destroyed by tlic severe frosts
of 1709 and I7G3, plants were raised from seed, and these
were found to be hardier and more productive than the
former kinds. Where plants are raised from seed in largo
quantities, varieties always occur diifering in constitution,
a-i well as others ditl'erijig in form or colour; but the former
cannot bo perceived by us unless marked out by their
behaviour under exceptional conditions, as in the foUomng
cases. After tho aevere winter of 1860-61, it was observed
that in a largo bed of araucarias some plants stood quite
unhurt among numbers killed around them. In Mr Darwin's
garden two rows of scarlet ranners were entirely killed by
frost, e-ijcept three plants, which had not even tho tips of
their leaves browned. A very excellent example is to be
found in Chinese Iiistory, according to M. Hue, who, in
his L'Empire Chinois (torn. iL p. 359), gives the following
extract from the Mtmoirs of the Emperor Kluxng : — "On
the 1st day of the 6lh moon I was walking in some fields
where rice had been so%vn to be ready for the harvest in
the 9 th moon. I observed by chance a stalk of rice
which was already in ear. It was higher than all the rest,
and was ripe enough to bo gathered. I ordered it to be
brought to me. The grain was very fine and well grown,
which gave mo the idea to keep it for a trial, and see if the
following year it would preserve its precocity. It did so.
All the stalks which came from it showed ear before
the usual time, and were ripe in the 6th moon. Each year
has multiplied the produce of the preceding, and for thirty
years it is this rice which has been served at my table. The
grain is elongate, and of a reddish colour, but it has a sweet
smell and very pleasant taste. It is called Yu-mi, Imperial
rice, because it was first cultivated in my gardens. It is
the only sort which can ripen north of the great wall,
where the winter ends late and begins very early ; but in
the southern provinces, where the climate is milder and the
land more fertile, two harvests a year may be easily ob-
tained, and it is for me a sweet reflection to have procured
that this kind of rice flourishes in Mandtchuria, where uo
other will grow. We have here, therefore, a perfect
example of acclimatisation by means of a spontaneous con-
stitutional variation.
That this kind of adaptation may be carried on step by
step to more and more extreme climates is illustrated by
the following examples. Sweet^peas raised in Calcutta
from seed imported from England rarely blossom, and never
yield seed ; plants from French seed flower better, but are
stiU sterile ; but those raised from Darjeeling seed (originally
imported from England) both flower and seed profusely. The
peach is belioijed to have been tender, and to have ripened
its fruit mth difficulty, when first introduced into Greece; so
that (as Darwin observes) in travelling northward during
two thousand years it must have become much hardier.
Dr Hooker ascertained the average vertical range of
flowering plants in the Himalayas to be 4000 feet, while in
some cases it extended to SOOO feet. The same species can
thus endure a great difference of temperature ; but the
important fact is, that the individuals have become accli-
matised to the altitude at which they grow, so that seeds
gathered near the upper limit of the range of a species will
be more hardy than those gathered near the lower limit.
This was proved by Dr Hooker to be the case with
Himalayaa conifers and rhododendrons, raised ia thie
country from seed gathered at diilcrcnt altitudes.
Among animals exactly analogous facts occur. II. Roulin
states that when geese were first introduced into Bogota
they laid few eggs at long intervals, and few of the young
survived. By degrees the fecundity improved, and iu
about twenty years became equal to what it is in Europe.
The game author tells us that, according to Garcilaso,
when fowls were first introduced into Peru they were not
fertile, whereas now they are as much bo as in Europe.
Mr Darwin adduces tho following examples. Jlerino sheep
bred at the Cape of Good Hope have Vjcen found far better
adapted for India than those imported from England ; and
while the Chinese variety of the Ailanthus silk-moth is
quite hardy, the variety iound in Bengal will only flourish
in warm latitudes. Sir Darwin also calls attention to the
circumstance that writers of agricultural works generally
recomniend that animals should be removed from one
district to another as little as possible. This advice occurs
even in classical and Chinese agricultural books as well
as in those of our own day, and proves that tho close
adaptation of each variety or breed to the country in which
it originated has always been recognised.
Conslilutional Adaptation often accompanied hy External
Modificatwn. — ; Although in some cases no perceptible altera-
tion of form or structure occurs when constitutional adapta-
tion to climate has taken place, in others it is very marked.
Mr Darwin has collected a large number of cases in his .-f n tmaU
and Plants under Domestication (vol ii. p. 277), of which the
following are a few of the most remarkable. Dr Falconer
observed that several trees, natives of cooler chmates,
assumed a pyramidal or fastigiatc form when grown in the
plains of India ; cabbages rarely produce heads in hot
climates ; the quality of the wood, the medicinal products,
the odour and colour of tho flowers, all change in many
cases when plants of one country are gro'ivn iu another.
One of the most curious observations is that of Mr Sleehan,
who " compared twenty-nine kinds of American tree;
belonging to various orders, with their nearest European
allies, all grown in close proximity in the same garden, and
under as nearly as possible the same conditions. In the
American species Mr Meehan finds, with the rarest excep-
tions, that the leaves fall earlier in the season, and assume
before falling a brighter tint; that they are less deeply
toothed or serrated ; that the buds are smaller ; that the
trees are more diflfuse in growth, and have fewer branchleu;
and, lastly, that the seeds are smaller ; — all in comparison
with the European species." Mr Darwin concludes that
there is no way of accounting for these uniform difi"erencc!
in the two series of trees than by the long-continued action
of the different climates of the two continents.
In animals equally remarkable changes occur. In
Angora, not only goats, but shepherd-dogs and cats, have
fine fleecy hair ; the wool of sheep changes its character in
the West Indies in three generations ; M. Costa states
that young oysters, taken from the coast of England,
and placed in the Mediterranean, at once altered their
uanner of growth and formed prominent diverging rays,
like those on the shells of the proper Mediterranean
oyster.
In his Contributions to tlte Theory of N'alural Selection
(p. 167), Mr Wallace has recorded cases of simultaneous
Tdriation among insects, apparently due to climate or other
strictly local causes. He fijids that the butterflies of the
family PapHionid<e, and some others, become sunilarly
modified in different islands and groups of islands. Thus,
the species inhabiting Sumatra, Java, and Borneo, are
almost always much smaller than the closely allied species
of Celebes and the Moluccas ; the species or varieties of
the «mnll island of Amboyna are larger than the same
ACCLIMATISATION
87
species or closely allied forms inhabiting tne eurrounding
ialands; the species found in Celebes possess a peculiar
form of wing, qni^p distinct from that of the same or
closely allied species of adjacent islands; and, lastly,
nnmerous species which have tailed wings in India and the
western islands of the Archipelago, gradually lose the tail
as we proceed eastward to New Guinea Mid the Pacific.
Many of these curious modifications mas', it is true, be
due to other causes than cUinate only, but they serve to
show how powerfully and ipysteriously local conditions
affect the form and structure of boVh plants and anipials ;
and they render it probable that changes of constitution
are also continually produced, although we have, iu the
majority of cases, no means of detecting them. It is also
impossible to- determine how. far the effects described are
produced by spontaneoiis favourable variations or by the
direct action of local conditions; but it is probable that in
every case both causes are concerned, e'though in constantly
a varying proportions.
The Infiuence of Heredity. — ^Adaptation by variation
would, however, be a slo'iv and uncertain process, and might
for considerable periods of time cease to act, did not heredity
come into play. This is the tendency of every organism to
produce its like, or more exactly, to produce a set of newforms
varying slightly from it in many directions — a group of which
the parent form is the centre. If now one of the most ex-
treme of these variations is taken, it is found to become the
centre of a new set of variations ; and by continually taking
the extreme in the same direction, an increasing variation in
that direction can be effected, until checked by becoming
so great that it interferes with the healthy action of the
organism, or is in any other way prejudicial It is also
found that acquired constitutional pecuharities are equally
hereditary; so that by a combination of those two modes of
variation any desired adaptation may be effected with
greater rapidity. The manner in which the form or
constitution of an organism can be made to change con-
tinuously in one direction, by means of variations which
are indefirJte and in ail directions, is often misunderstood.
It may perhaps be illustrated by showing how a tree or
grove of trees might, by natural causes, be caused to travel
during successive generations in a definite course. The
tree has branches radiating out from its stem to perhaps
twenty feet • on every side. Seeds are produced on the
extremities of all these branches, drop to the ground, and
produce seedlings, which, if untouched, would form a ring
of young trees around the parent. But cattle crop off
every seedling as soon as it rises above the ground, and
none can ever airive at maturity. If, however, one side is
protected from the cattle, young trees will grow up on that
side only. This protection may exist in the case of a grove
of trees which we may suppose to occupy the whole space
between two deep ravines, the cattle existing, on the lower
side of the wood only. In this case young trees would
reach maturity on the upper side of the wood, while on the
lower side the trees would successively die, f&U, and rot
away, no young ones taking their place. If this state of
things continued unchanged for some centuries, the wood
might march regularly up the side of the mountain tdl it
occupied a position many miles away from where it once
stood ; and this would have taken place, not because more
seed was produced on one side than the other (there might
even be very much less), nor because soil or climate were
better on the upper side (they might be worse), nor because
any intelligent being chose which trees should be allowed
to live and which should be destroyed; — but simply because,
for a series of generations, tine conditions permitted the
existence of young tress on one side, and wholly prevented
it on the other. Just in an analogous way animals or
plants arc caused to varj in definite directions, either by
the influence of natural agencies, which render existence
impossible for those that vary in any other direction, or
by the action of the judicious breeder, who carefully selects
favourable variations to be the parents of his future stock ;
and in either case the rejected variations.may far outnumber
those which are preserved.
Evidence has been adduced by Mr Darwin to show that
the tendency to vary is itself hereditary; so that, so far
from variations coming to an end, as some persons imagine,
the more extensively variation has occurred in any specie."}
in the' past, the more likely it is to occur in the future.
There is also reason to believe that individuals which have
varied largely from their parents in a special direction will
have a greater tendency to produce offspring varying in
that direction than in any other ; so that the facUities for
adaptation, that is, for the production and increase of
favourable variations in certain definite directions, are fur
greater than the facilities for locomotion in one direction in
the hypothetical illustration just given.
Selection and Survival of the Fittest as Agents in UTaiura-
lisaiion. — We may now take it as an established fact, that
varieties of animals and plants occur, bothin domesticity and
m a state of nature, which are better or worse adapted to
special climates. There is no positive evidence that the
influence of new climatal conditions on the parents has any
tendency to produce variations in the offspring better adapted
to, such conditions, although some of the facts mentioned
in the preceding sections render it probable that such may
be the case. Neither does it appear that this cla.ss of
variations are very frequent. It is, however, certain that
whenever any animal or plant is largely propagated con-
stitutional variations will arise, and some of these wiU be
better adapted than others to the climatal and other
conditions of the looahty. In a state of nature, every
recurring severe winter or otherwise unfavourable season,
weeds out those individuals of tender constitution or
imperfect structure which may have got on very well during
favourable years, and it is thus that the adaptation of the
species to the climate in which it has to exist is kept up.
Under domestication the same thing occurs by what Mr
Darwin has termed "unconscious selection." Each culti-
vator seeks out the kinds of plants best suited to his soil
and climate, and rejects those which are tender or otherwise
unsuitable. The farmer breeds from such of his stock as
he finds to thrive best with him, and gets rid of those
which suffer from cold, damp, or disease. A more or less
and breeds or races are produced which are sometimes
liable to deterioration on removal even to a short distance
in the same country, as in numerous cases quoted by Mr
Darwin {Animah and Plants under Domestication^ voL ii.
p. 273).
The Method of Acclimatisation. — Taking into considera-
tion the foregoing facts and illustrations, it may be con-
sidered as proved — \st, That habit has little (though it
appears to have some) definite effect in adapting the
constitution of animals to a new cKmate ; but that it has a
decided, though stUl slight, influence in plants when, by
the process of propagation by buds, shoots, or grafts, the
individual can be kept under its influence for long periods ;
2c?, That the offspring of both plants and animals vary
in their constitutional adaptation to climate, and that
this adaptation may be kept up and increased by means
of heredity; and, Zd, That great and sudden changes
of climate often check reproduction even when the health
of the individuals does not appear to suffer. In order,
therefore, to have the best chance of acclimatising any
animal or plant in a cUmate very dissimilar from that uf
its native country, and in which it has been proved thit
the g)ecicR in question cannot live and maintain itsdl
88
ACCLIMATISATION
vrithout acclimatisation, wo must adopt somo such plan
as the following : —
1. AVe must transport as largo a numoer as possible of
adult healthy individuals to some intermediato station,
and increase them as much as possible for some years.
Favourable variations of constitution will soon show thom-
Bclves, and these should be carefully selected to breed from,
the tender and unhealthy individuals being rigidly elimi-
nated.
2. As soon as the stock has been kept a sufficient time
to pass through all the ordinary extremes of climate, a
number of the hardiest may bo removed to the moro remot*
station, and the same process gone through, gi^^ng protection
if necessary while the stock is being increased, but as soon
as a largo number of healthy individuals are produced, sub-
jecting them to all the vicissitudes of the climate.
It can hardly be doubted that in most cases this plan would
succeed It has been recommended by Mr Darwin, and at
one of the early meetings of the Socidt^ Zoologique d' Acclim-
atisation, at Paris, M. Geoffroy St Hilaire insisted that it was
the only method by which acclimatisation was possible.
But in looking through the long series of volumes of Repprts
attempt at -icclimatisation has even once been made. A
number of foreign animals have been introduced, and more or
loss domesticated, and some useful exotics have been culti-
vated for the purpose of testing their applicability to French
agriculture or horticidture ; but neither in the case of
animals nor of plants has there been any systematic effort
to modify the constitution of the species, hy breeding lai-gdy
and selecting the favourable variatiojis t/uxt appeared.
Take the case of the Eucalyptiu globulus as an example.
This is a Tasmanian gum-tree of very rapid growth and
great beauty, which will thrive in the extreme south of
France. In the Bulletin of the Society a large number of
attempts to introduce this tree into general cultivation in
other parts of France are recorded in detail, w-ith the failure
of almost all of them. But no precautions such as those
above indicated appear to have been taken in any of these
experiments ; and we have no intimation that either the
Society or any of its members are making systematic
efforts to acclimatise the tree. The first step would be, to
obtain seed from healthy trees growing in the coldest
climate and at the greatest altitude in its native country,
sowing these very largely, and in a variety of soils and
situations, in a part of France where the cUmate is some-
what but not much more extreme. It is almost a certainty
that a number of trees would be found to be quite hardy.
A3 soon as these produced seed, it should be sown in
the same district and farther north in a climate a little
more severe. After an exceptionally cold season, se^d
should be collected from the trees that suffered least, and
should be sown in various districts all over France. By
such a process there can bo hardly any doubt that the tree
would be thoroughly acclimatised in any part of France,
and in many other countries of central Europe ; and more
good Tvould be effected by one well-directed effort of this
kind than by hundreds of experiments with individual
animals and plants, which only serve to show us which are
the species that do not require to be acclimatised.
Acclimatisaiion of Man. — On this subject we have, un-
fortunately, very little direct or accurate information. The
general laws of heredity and variation have been proved to
apply to man as well as to animals and plants ; and nume-
rous facts in the distribution of races show that man mus^, in
remote ages at least, have been capable of constitutional
adaptation to climate, if the human race constitutes a single
species, then the mere fact that man now inhabits every
region, and is in each case constitutionally adapted to the
climate, proves that acclimatisation has occurred. But we
have the same phenomenon in single 7arieties of man, such at
the American, which inhabits alike the frozen wastes of
Hudson's Bay and Terra del Fuego, aq^ the hottest regions
of the tropics, — the low equatorial valleys and the lofty
plateaui of the Andes. No doubt a sudden transference
to an extremo climate is often prejudicial to man, as it it
to most animaU and plants ; but there is every reason to
believe that, if the migration occurs step by step, man can
bo acclimatised to almost any part of the earth's surface
in comparatively few generations. Some eminent writers
have .denied this. Sir Ranald ilartin, from a consideration
of the effects of the climate of India on Europeans and
their offspring, believes that there is no such thing aa
acclimatisation. Dr Hunt, in a report to the British
Association in 1861, argues that "time is no agent," and
— " if there is no sign of acclimatisation in one generation,
there is no such process." But he entirely ignores th«
effect of favourable variations, as well as the direct in-
fluence of climatto acting on the organisation from infancy. ,
Professor Waitz, in his Introduction to Anthropology,
adduces many examples of the comparatively rapid con-
stitutional adaptation of man to new clijuatic conditions.
Negroes, for example, who have been for three or four
generations acclimatised in North .Ajuerica, on returning to
Africa become subject to the same local diseases as other
unaccUmatised individuals. He well remarks, that the
debility and sickening of Europeans in many tropical
countries are wrongly ascribed to the climate, but are
rather the consequences of indolence, sensual gratification,
and an irregular mode of life. Thus the English, who
cannot give up animal food and spirituous liquors, are leaf
able to sustain the heat of the tropics than the more sobei
Spaniards and Portuguese. The excessive mortality of
European troops in India, and the delicacy of the children
of European parents, do not affect the real question of
acclimatisation under proper conditions. They only show
that acclimatisation is in most cases necessary, not that it
cannot take place. The best examples of partial or com-
plete acclimatisation are to be found where European races
have permanently settled in the tropics, and have maintained
themselves for several generations. There are, however,
two sources of inaccuracy to be guarded against, and these
are made the most of by the writers above referred to, and
are supposed altogether to invalidate results which ara
otherwise opposed to their views. In the first place, we
have the possibility of a mixture of native blood having
occurred ; in the second, there have almost always been a
succession of immigiants from the parent country, who
continually intermingle with the families of the early
settlers. It is maintained that one or other of tliese
mixtures is absolutely necessary to enable Europeans i»
continue long to flourish in the tropics.
There are, however, certain cases in which the sources
of error above mentioned are reduced to a minimum, and
cannot seriously affect the results ; such as those of the
Jews, the Dutch at the Cape of Good Hope and in the
Moluccas, and the Spaniards in South America.
The Jews are a good example qf acclimatisation, because
they have been established for many centuries in climates
very different from that of their native land ; they keep
themselves almost wholly free from intermixture with the
people around them ; and they are often so populous in a
countr}- that tho intermixture with Jewish immigrants from
other lauds cannot seriously affect the local purity of the
race. They have, for instance, attained a population of near
two millions in such severe climates as Poland and Russia ;
and according to Mr Brace {Haces of the Old World, p. 1S5),
" their increase in Sweden is said to be greater than that
of the Christian population'/ in the towns of Algeria they
are the only race able to maintain its numben; and in
i^ C G L 1 1\I A T I S A T I N
89
•Cocliin Cliina and AJeu tlifty succeed in rearing children
and forming permanent communities."
In some of the hottest parts of South America Europeans
arc perfectly acclimatised, and where the race is kept pure
it seems to be even improved. Some very valuable notes
on tliis subject have been furnished to the present writer
by tho well-known botanist Dr Richard Spruce, who resided
many years in South America, but who has hitherto been
prevented by ill health from giving to the world the results
of his researches. . Aa a careful, judicious, and accurate
observer, both of man and nature, he has few superiors.
Ce saySf—
^.5 The white inhabitants of Guayaquil (lat. 2° 13' S.) are
kept pure by careful selection. The slightest tincture of
red or black blood bars entry into any of the old families
who are descendants of Spaniards from tho Provincias
Vascongadas, or those bordering the Bay of Biscay, where
the morals are perhaps the purest (as regards the intercourse
of the sexes) of any in Europe, and where for a girl, even
of the poorest class, to have a child before marriage is the
rarest thing possible. Tho . consequence of this careful
breeding is, that the women' of Guayaquil are considered
(and justly) the finest along the whole Pacific coast. They
are often taU, sometimes very handsome, decidedly healthy,
iJthough pale, and assuredly prolific enough. Their sons
are big, stout men, but when they lead inactive lives are
apt to become fat and sluggish. Those of them, however,
who have farms in the savannahs, and are accustomed to
take long rides in aU weathers, and those whose trade
obb'ges them to take frequent journeys in the mountainous
interior, or even to Europe and North America, are often as
active and as little burdened with superfluous flesh aa a
Scotch farmer
" The oldest Christian town in Peni is Piura (lat. 5° S.),
which was founded by Pizarro himself. The climata is
very hot, especially in the three or four months following
the southern solstice. In March 1813 the temperature
only once fell as low as 83", during the whole month, the
usual lowest night temperature being 85°. Yet people of
all colours find it very healthy, and the whites are . veiy
prolific. I resided in tho town itself nine months, and in
tho neighbourhood seven months more. The population
(in 18G3-4) was about 10,000, of which not only a
considerable proportion was white, but was mostly descended
torn the filrst emigrants after the conquest. Purity of
descent was not, however, quite so strictly maintained as
at Guayaquil. The military adventurers, who have often
risen to high or even supreme rank in Peru, have not seldom
been of milled race, and fear or favour has often availed to
procure thorn an aUiauco with tho oldest and purest-blooded
families."
These instances, so well stated by Dr Spnice, seem to
demonstrate the complete acclimatisation of Spaniards in
some of the hottest parts of South America. Although
wo have here nothing to do with mixed races, yet the want
of fertility in these has been often tc.ken to be a fact
inlierent in the mongrel race, and has been also sometimes
held to prove that neither the European nor his half-bred
oQ'spring can maintain themselves in the tropics. Tho
following observation is therefore of interest : —
" At Guayaquil for a lady of good family — married or
tmmarricd — to be of loose morals is so uncommon, thst
when it does happen it is felt as'a calamity by tho whole
community. , But here, and perhaps in most other towns
in South America, a poor girl of mixed race — -especially if
good-looldng — rarely thinks of marrying 'one of her own
cla.s3 until she has — as the Brazilians say — ' approveitada
presents froih gmtUmen. If she thus bring a good dowTy
to.bjjr husband,. he does not care to inquire, or is not
sensitive, about the mode in wliich it was acquiied. The
consequences of this indiscriminate sexual intercourse, espe-
cially if much prolonged, is to diminish, in some cases to
paralyse, the fertility of tho female. And as among people
of mixed race it is almost universal, the population of
these must fall off both in numbers and quality."
The following example of divergent acclimatisation of
the same race to hot and rold zones is very interesting,'
and will conclude our extracts from Dr. Spruce's valuable
notes :^.
"One oi the most singular cases _ connected with this
subject that have fallen under my own observation, is the
difficulty, or apparent impossibility, of acclimatising the
Red Indian in a certain zone of the Andes. Any person
who has compared the physical characters of the native
races of South America must be convinced that these have
aU originated in a common stirps. Many local differences
exist, but none capable of invalidating this conclusion.
The warmth yet shade-loving Indian of the Amazon ; tho
Indian of the hot, dry, and treeless coasts of Fern and
Guayaquil, who exposes his bare head to the sun with aa
much zest as an African negro ; the Indian of the Andes,
for whom no cold seems too great, who goes constantlj
bare-legged and often bare-headed, through whose rude
straw hut the piercing wind of the ■ paramos sweeps, and
chills the white man to the very bones ; — all these, in the
colour and texture of tho skin, the hair, and other important
features, are plainly of one apd the same race
"Now there is a zone of the equatorial Andes, ranging
between about 4000 and COOO feet altitude, where the vcjy
best flavoured coffeo is grown^ where cane is less luxuriant
but more saccharine than in the plains, and which is
therefore very desirable to cidtivate, but whore the red
man sickens and dies. Indians taken down from the sierra
get ague and dysentery. Those . of the plains find the
temperature chilly, and are stricken' down with influenza
and pains in the Umbs.'. I -have seen the difficulty
experienced in getting fands cultivated in this zone, on
both sides of the CordiUcra. The permanent residents are
generally limited to the major domo and his family ; and
in the diy season labourers are hired, of any colour that
can bo obtained — some from the low country, others from
tho highlands — for three, four, or five months, who gathei
in and grind the cane, and plant for the harvest of the
following year; but a staff of resident Indian labourers,
such as exists in the farms of the sierra, cannot be kept up
in the Yungas, as these half-warm valleys are caUei
\Miite men, who take proper precautions, and are not
chronically soaked with ca'ae-spirit, stand the climate
perfe(;tly, but tho Creole whites are still too much cahalleros
to devote themselves to agricultural work. .
"In what is now tho :opublic of Ecuador, tho onlj
peopled portions are the central valley, between tho two
ridges of the Andes— height 7000 to 12,000 feet— and tjio
hot plain at their western base ; nor do the wooded slopes
appear to have been inhabited, except by scattered savage
hordes, even in the time of the Incas The Indians of tho
highlands are the des^^cndants of others who have inhabited
that region exclusively for untold ages ; and a similar
affirmation may be made of the Indiajis of the plain. Now,
there is little doubt that the progenitors of both these
sections came from a temperate region (in North America) ;
so that here we?have one moiety acclimatised to endure ex-
treme heat, and the other extreme cold ; and at this day
exposure of either to the opposite extreme (or even, as wo
have seen, to the climate of an intermediate zone) is always
pernicious and often JataL ^'Bitt if this great difl'erence has
been brought about in the red man, might not the same
have happened to the white man 1 Plainly it might, time
being given ; for one cannot doubt that tho inherent adapts
I. — 12
90
A C C— A C C
bility is the- same in both, or (if not) that the white man
possesses it in a higher degree."
The observations of Dr Spruce are of tnemselves aunost
couclusive as to the possibility of Europeans becoming ac-
climatised in the tropica ; and if it is objected that this
eWdence applies only to the darli-haired southern races, we
are fortunately able to point to facts, ohnost equally well
authenticated and conclusive, in the case of one of the typi-
cal Germanic races. At the Cape of Good Hope the Dutch
have been settled and nearly isolated for about 200 years,
and have kept themselves almost or quite free from native
intermixture. They are described as being still perfectly
fair in complexion, while physically they are the finest body
of men in the co'ony, being very tall and strong. They
marry young, and have large families The population,
according to a census taken in 1798, was under 22,000.
In 1865 it was near 182,000, the majority being (according
to the Slates7naii's Year Book ioi 1873) of "Dutch, German,
or French origin, mostly descendants of original settlers."
We have here a population which has doubled itself every
twenty-two years ; and the greater part of this rapid in-
crease must certainly be due to the old European immi-
grants. In the Moluccas, where the Dutch have had settle-
ments for nearly 250 years, some of the inhabitants trace
their descent to early immigrants; and the^(;, as well as
most of the people of Dutch descent in the East, are quite
as fair as their European ancestors, enjoy excellent health,
and are very prolific. But the Dutch accommodate them-
selves admirably to a tropical climate, doing much of their
work early in the morning, dressing very lightly, and living
a quiet, temperate, and cheerful life They also pay great
attention to drainage and general cleanliness. In addition
to these examples, it may be maintained that the rapid in-
crease of English-speaking populations in the United States
and in Australia, only a comparatively small portion of
which can be due to direct imnugration, is far from support-
ing the view of Dr Knox, that Europeans cannot per-
manently maintain themselves in those coimtries. Mr
Brace expressly denies that the American physique has
degenerated from the English type. He asserts that manu-
facturers and others find that " for labours requiring the
utmost physical endurance and muscular power, such as
iron-puddling and lumbering in the forests and on the
streams, and pioneer work, foreigners are never so suitable
as native Americans. The reports of the examining sur-
geons for volunteers — such as that of Dr W. H.' Thomson
to the Surgeon-General in 1862, who examined 9000 men
— show a far higher average of physique in the Americans
examined than in the English, Germans, or Irish. It is a
fact wcU known to our life insurance companies, that the
average length of life here is greater than that of the
English tables."— rAe Races of tlt€ Old World, p. 375.
Although the comparisons here instituted may not be quite
fair or contlusive, they furnish good arguments against those
who maintain that the Americans are physicaUv deteriorat-
ing.
On the whole, we seem justified in concluding that, under
favourable conditions, and with a proper adaptation of means
to the end in view, man may become acclimatised with at
least as much certainty and rapidity (counting by generations
rather than by years) as any of the lower animals. ( a. R. w.)
ACCOLADE (from collum, the neck), a ceremony an-
ciently used in conferring knighthood ; but whether it was
an embrace (according to the use of the modern French word,
accolade), or a slight blow on the neck or cheek, is not
agreed. Both these customs appear to be of great antiquity.
Gregory of Tours \4Tites that the early kings of France, in
conferring the gilt shoulder-l;elt, kisoeu the knights on the
left cheek ; and Wiliiam the Conqueror is said to have
made use of the blow in conferiiug the honour of knight-
hood on his son Henry. At first it was given iN^th the
naked fist, a veritable box on the ear, but for this was
substituted a gentle stroke on the shoulder with the flat of
the sword. A custom of a similar kind is still fallowed in
•icstowing the honour of knighthood.
ACCOLTI, Benedict, was born in 1415 at Arczzo, in
Tuscany, of a noble family, several members of which were
distinguished like himself for their attainments in law.
He vss for some time professor of jurisprudence in the
University of Florence, and on the death of the celebrated
Poggio in 1459 became chancellor of the Florentine re-
pubha He died in 1466. In conjunction ^nth his brother
Leonard, he wrote in Latin a history of the first crusade,
entitled De Bella a ChrUliania contra Barbaros, pro Chriati
Sepulchre et Judafa recuprrandis, libri trei, which, though
itself of little interest, furnished Tasso with the hLstoric
basis for his Jerusalem Delivered. This work appeared at
Venice in 1432, and was translated into Italian in 1543,
and into French in 1620. Another work of Accolti's — De
Prccstantia, Virorum sui jEvi — vras published at I'arma in
1GS9.
ACCOLTI, Beenaed (1465-1535), son of tno preced-
ing, known in his own day as I'Unico Aretino, acquired great
fame as a reciter of impromptu verse. He was listened to by
large crowds, composed of the most learned men and the most
distinguished prelates of the age. Among others. Cardinal
Eembo h.as left on record a testimony to his extraordinary
talent. His high reputation v\-ith his contemporaries seems
scarcely justified by the poems he published, though they
give evidence of brilliant fancy. It is probable that he
succeeded better in his extemporary productions than in
those which were the fruit of deliberation. His works,
under the title Virginia, Comedia, Capitoli e Stramhotli di
Messer Bernai/lo Accolti Aretino, were published at Florence
in 1513, and have been several times reprinted.
ACCOLTI, PiETRO, brother of the preceding, was bom
at Florence in 1455, and died there in 1549 He was
abbreviator under Leo X., and in that capacity drew up
in 1520 the famous bull against Luther. In 1527 ho was
as his secre'iary.
ACCOMilODATION, a term used in Biblical interpre-
tation to denote the presentation of a truth not absolutely
as it is in itself, but relatively or under some modification,
with the view^ of suiting it either to some other truth or to
the persons addressed. It is generally distinguished into
formal and material, — the accommodation in the one case
being confined to the method uf teaching, and in the other
being extended to the matter taught To the former head
may be referred teaching by symbols or parables, by pro-
gressive stages graduated according to the capacity of the
learner, by the application of prophecy to secondary fulfil-
ments, ic. To the latter head are to be referred the alle-
gations of the anti-supranaturalistic school, that Christ and
the writers of Scripture modified or perverted the truth
itself in order to secure wider acceptance and speedier
success, by speaking in accordance with contemndrary ideas
rather th.in with absolute and eternal truth.
ACCOMMODATION, in commerce, denotes generally
temporary pecuniary aid given by one trader to another, oi
by a banker to his customers, but it is used more par-
ticularly to describe that class of bills of exchange which
represents no actual exchange of real Value between the
parties.
ACCOEAMBONI, Vittoria, an Italian lady remarK-
able for her extraordinary beauty and her tragic history.
Her contemporaries regarded her as the most captivating
woman that had ever been seen in Italy. She was sought
in marriage by Paolo Giordano Orsini, Duke of Bracciano,
who, it was generally telieve<l. had murdered his wife,
A C C — A C C
91
Isabella- de Medici, with his own hand; but her father
gave her in preference to Francesco Peretti, nephew of
Cardinal Montalto. Peretti was assassinated (1581), and
a few days afterwaMs Vittoria fled from the house of the
Cardinal, where she had resided, to that of the Duke of
Bracciano. The opposition of Pope Gregory XIII., who
even went so far as to confine Vittoria to Fort St Angelo
for nearly a year, did not prevent her marriage with the
duke. On the accession of Montalto to the papal throne
as Sixtus V. (1585), the duke thought it prudent to take
refuge with his wife in the territory of the Venetian
republic. After a few months' residence at Salo, on the
Lake of Garda, he died, bequeathing nearly the whole of
his large fortune to his widow. This excited the anger of
Ludovico Orsini, a relative, who caused Vittoria to be
murdered in her residence at Padau (Dec. 22, 1585). The
history of this beautiful and accomplished but unfortunate
woman has been written by Adry (1800), and recently by
Count Gnoli, and forms the basis of Webster's tragedy. The
While Devil, and of Tieck's romance, Vittoria Accoramboni.
ACCORDION' (from the French accord), a small musical
instrument in the shape of a bellows, which produces sounds
by the action of wind on metallic reeds of various sizes.
It is played by being held in both hands and puUed back-
wards and forwards, the fingers being left free to touch
the keys, which are ranged along each side. The instru-
ment is akin to the concertina, but differs from it in having
the chords fixed by a mechanical arrangement. It is manu-
factured chiefly in Paris.
ACCORSO (in Latin Accursim), Fkancis, an eminent
lawyer, born at Florence about 1182. After practising
for some time in his native city, he was appointed professor
at Bologna, where he had great success as a teacher. He
undertook the great work of arranging into one body the
almost innumerable comments and remarks upon the Code,
the Institutes, and Digests, the confused dispersion of which
among the works of different writers caused much obscurity
and contradiction. 'When he was employed in this work,
it is said that, hearing of a similar one proposed and begun
by Odofred, another lawyer of Bologna, he feigned indis-
position, interrupted his public lecture's, and shut himself
up, till he had, with the utmost expedition, accomplished
his design. His work has the vague title of the Great Gloss,
and, though written in barbarous Latin, has more method
than that of any preceding writer on the subject. The
best edition of it is that of Godefroi, published at Lyons in
1589, in C vols. foUo. Accursius was greatly extolled by
the lawyers of his own and the immediately succeeding age,
and he was even called the Idol of Jurisconsults, but those
of later times formed a much lower estimate of his merits.
There can be no doubt that he has disentangled with
much skill the sense of many laws ; but it is equally un-
deniable that his ignorance of history and antiquities has
often led him into absurdities, and been the cause of many
defects in his explanations and Commentaries. He died at
Bologna in 1260. His eldest son Francis, who filled the
chair of law at Bologna with great reputation, was invited
to Oxford by King Edward L, and in 1275 or 1270 read
lectures on law in that university. In 1280 he returned to
Bologna, where ho died in 129.3.
ACCORSO (or Acoursios), Maeiangelo, a learned and
ingenious critic, was born at Aquila, in the kingdom of
Naples, about 1490. He was a great favourite with
Charles V., at v.-hose court he resided for thirty-three years,
and by wliom he was employed on various foreign mi.ssions.
To a perfect knowledge of Greek and Latin he added an
intimate acquaintance with several modern languages. Tn
discovering and collating ancient manuscripts, for which his
travels abroad gave him special opportunities, he displayed
nncomraon diligence. Hia work entitled Dialribac in
Avwmwm, Solin.um, ei Oindium, pnnted at Rome, in folio,
in 1524, is a singular monument of erudition and critical
skiU. He bestowed, it is said, unusual pains on Claudian,
and made, from different manuscripts, above seven hundred
corrections on the works of that poet. Unfortunately thtese
criticisms were never published. He was the first editor
of the Letters of CcLssiodorus, with his Treatise on the Soul;
and his edition of Ammianus Marcellinus (1533) contains
five books more than any former one. The affected use of
antiquated terms, introduced by some of the Latin writers
of that age, is humorously ridicided by him, in a dialogue
published in 1531 (republished, with his name, in 1574),
entitled Osco, ■ Volsco, Romaiw.que Eloquentia Interlocu-
toribus, Dialogtis I/udia Romania actus. Accorso was
accused of plagiarism in his notes on Ausonius ; and the
determined maimer in which he repelled, by a most solemn
oath, this charge of literary theft, presents us with a singular
instance of anxiety and care to preserve a literary reputa-
tion unstained.
ACCOUNT, a Stock Exchange term : e.gr., " To Buy or
Sell for the Account," &c. The word has different, though
kindred, significations, all derived from the making up and
settling of accounts on particular days, in which stricter
sense the word " Settlement " is more specially used.
The financial importance of the Account may be gathered
from the Clearing House returns. Confining ourselves to
the six years, from the 30th of April 1867 to the 30th of
April 1873, we have the following figures, furnished by
the Clearing House to Sir John Lubbock, and communi-
cated by him to the Times: —
On fourths On Stock Excli&nge On Consols
April April of the Month. Account Oavs. Settling Days.
1867 to 1868 £147,113,000 £444,443,000 £132,293,000
1868 to 1869 161,861,000 550,622,000 142,270,000
1869 to 1870 168,523,000 594,763,000 148,822,000
1870 to 1871 186,517,000 635,946,000 169,141,000
1871 to 1872 229,629,000 942,446,000 233,843,000
1372 to 1873 265,965,000 1,032,474,000 243,561,000
During the year ending April 30, 1873, the total amount of bills,
checks, &c., paid at the Clearing House showed an increase of
£643,613,000 during the same period ending April 1872, and of
£2, 745,924, 000 over 1868. The amounts passing through on the
iths of the month amounted to £265,965,000, showing an increase
of £36,336,000 over 1872. The payments on Stock ExchaT^ge
Account Days formed a sum of £1,032,474,600, being an increase
of £00,028,000 over 1872. The payments on Consols Account Days
for the same period amounted to £243,561,000, giving an iccrfease
of £9,718,000 over 1872.
In English and Indian- Government Securities, the settle-
ments are monthly, and for foreign, railway, and other
securities, generally speaking, they are tortnightly. It
follows therefore that in 1867-1868, an ordinary Stock
Exchange Account Day involved payments, on Stock
Exchange accounts only, averaging about X10,000,000
sterling, and ia 1872-3 something like £25,000,000 ster-
ling; and these sums again, enormous aa they are, repre-
sent for the most part only the balance of much larger
transactions. The London Account is, in fact, probably
the greatest and most important periodical event in the
financial world. The great European centres have their
own Account Days and methods of settlement, but the
amounts dealt in are very much less than on the London
market. The leading cities in the United Kingdom have
also their Stock Exchanges, but their practice follows more
or less that of London, where the bulk of their business is
transacted by means of post and telegraph.
The Account in Consols or other English Government
Securities, or in the securities of the Government of India,
or in Bank of England Stock, or other Stocks transferable
at the Bank of England, extends over a month, the settle-
ments being monthly, and in them the committee of the
Stock Exchange does not take cognisance of any bargain
for a future account, if it shall have been effected mon
y2
A C C - A C E
than eight days previously to tho close of tlio existing
account.
The Account in Securities to Bearer, ana, with the above
exceptions, in Registered Senirities also, extends over a
period of from tw^ve to nineteen days. Tliis period is in
each case terminated by the "settlement," which occurs
twice in each mouth (generally about the middle and end),
on days fi.\ed by tho committee for general pui-posee of the
Stock E.xcliange in tho preceding month.
This "settlement" occupies three continnous days, which
are all termed Account days, but the third day is the true
Account, Settling, or Pay Day.
Continuation or Carrj-ing-over is tlio operation by which tho
sottlement of a liargain Iransactod for money, or for a given account,
may for a consideration (called either a "Contango" or a "back-
wardation") bo deferred for "the period of another account. Such
a continuation is equiTnlent to a sale "for the day," and a repur-
cha.'io for the suocaeding account, or to a purchase " for the day,"
ud a re-sale for tho succeediug account. The price at which such
transactions are adjusted is tho "Making-Up" price of the day.
CotUango is a technical term which expresses the rate of in-
terest charged for the loan of money upon the security of stock
transferred for the period of an account or otherwise, or the rate of
interest paid by the buyer to the seller to be idlowed to defer paying
for the stock purchased, until the next settlement day.
Bacbtvardation, or, aa it is more often called, Back (for brevity),
in contradistinction to contango, is the amount charged for the
loan of stock from one account to tho other, and it is paid to the
purcliaser by the seller in order to allow the seller to defer tho deli-
very of the stock.
A Bull AccoujU is one in which either the ptirchasea have pre-
dominated over the sales, or the disposition to purchase hafl ))cen
more marked than the disposition to sell.
A Bear Account is one in which either the sales have preponderated
over the purcha.ses, or in which the disposiition to sell has been
more strongly displayed than the disposition to buy.
Sometimes the Bull or tho Bear disposition extends to the great
majority of securities, as when there are general falls or general
rises. Sometimes a Bull Account in one set of securities is con-
temporaneous with a Bear Account in another. — Vide Cracroft's
Stock Exchanijc ilaniuil,
ACCOUNTANT, earlier form Accomptant, in the
most general sense, is a person skilled in accounts. It k
appHed to the person who has tho charge of the accounts
in a pubUo office or in the counting-house of a large private
bu.sine3.s. It is also tho designation of a distinct profession,
ivhich deals in any required way with mercantile accounts.
ACCOUNTANT-GENERAL, an officer in the English
Court of Chancery, who receives all monies lodged in court,
and by whom they are deposited in bank and disbursed.
ACCRA or Acr.^, a town, or rather a collection of
forts, in a territory of tho same name, on the Gold Coast of
Africa, about 75 miles east of Cape Coast Castle. Of the
forts. Fort St James is a British settlement, Crivecoeur
was established by the Dutch, and Christianborg by the
Danes ; but the two last have since been ceded to Britain —
Christianborg in 1850, and Crfevecceur in 1871. Accra
is considered to be one of the healthiest stations on the west
coast of Africa, and has some trade in the productions of
the interior, — ivory, gold dust, and pabn-oil ; while cotton
goods, tobacco, rum, and beads are imported in exchange.
It is the residence of a British civil commandant.
ACCRINQTON, an important manufacturing town of
England, in Lancashire, lies on the banks of a stream caUed
the Hindbnm, in a deep valley, 19 miles N. from Man-
chester and 5 miles E. of Blackburn. It has increased rapidly
in recent years, and is the centre of the Manchester cotton-
printing trade. There are large cotton factories and prints
works, besides bleach-fields, Ac, employing many hands.
Coal is extensively wrought in the neighbourhood. The
town has a good appearance, and amongthe more handsome
buildings are a fine church, in the Gothic style, erected in
• 1838, and the Peel In^itution, an Italian structure, contain-
ing an assembly room, a lecture room, &c., The sanitary
arrangements generally are good, and a reservoir capabb
of containing 140,000,000 gallons has been constructed for
tho water supply of the town. Accrington is a station on
tho Lancasliiro and Yorkshire Railway. The population of
the two townships of Old and New Accrington was in 18C1,
17,688 ;. and in 1S71, 21,788.
ACCUM, Fkkdeeick, chemist; bom at BiickeDurg in
1709, came to London in 1793, and was appointed teacher
of ohemij-'try and mineralogy at the Surrey Institution in
1801. While occupying this position he published several
scientific manuals {VlteviUtry, 1803; Mineralogy, 1808;
Crystodlography, 1813), but his name will be chiefly re-
membered in connection with gas-lighting, the introduction
of which was mainly due to him and to the enterprising
printseller, Ackennann. His excellent Practical Treatise
on Gaslight appeared in 1815; and he rendered another
valuable service to society by his Treatise on Adulterations
of Food and Culinary Poisons (1820), which, attracted
much notice at the time it appeared. Both works, as well
as a number of his smaller pubUcations, were translated
into German. In consequence of charges affecting his
honesty, Accum left London for Germany, and in 1822
was appointed professor in the Industrial Institute and
Academy of Architecture at BerUn. He died there in 1838.
ACCUMULATOR, a term applied frequently to a
powerful electrical machine, which generates or accumu-
lates, by means of friction, electric currents of high ten-
sion, — manifested by sparks of considerable length.
Accumulators have been employed in many places for
exploding torpedoes and mines, for blasting, &c An
exceedingly powerful apparatus of this kind was employed
by tho Confederate authorities during the civil war in
America for discharging subinarine and river torpedoes.
Whatever the nature of the materials employed in the con-
struction of the accumulator, or the form which it may
assume mechanically, it is simply a modification of, or an
improvement upon, the ordinary cylindrical or the plate-
glass frictional electrical machine, — the fundamental
scientific principles being the same in nearly every easa The
exciting body consists generally of a large disc or circular
plate of vulcanite, — more frequently termed by electricians
" ebonite," in consequence of its resemblance, in point of
hardness and of polish, to polished ebony,^the vulcanite
disc taking the ulace of the ordinary circular plate •(
thick glas?.
ACE, the received name for the single poiat on cards or
dice — the unit. Mr Fox Talbot has a speculation (English
Etymologies, p. 262) that the Latins invented, if not the
game of dice, at least the name for the smgle point, which
they called unus. The Greeks corruptc-d this into wos,
and at length the Germanic races, learning the game from
the Greeks, translated the word into ass, which has now
become ace The fact, however, is, that the root of the
word lies in the Latin as, the monetary unit, which is to
be identified with the Greek cts; Doric, ats or &
ACEPHALA, a name sometimes given to a section of
thei molluscous animals, which are diidded into encephala
and acephala, according as they have or want a distinctly
differentiated head. The Acephala, or Lamellibranchiata,
as they are also called, are commonly known as bivalve
shell-fish.
ACEPHALI (from d privative, and kci^oXtJ, a head), a
and in particular to a sect that separated itself, in the end
of the 5th century, from the rule of the patriarchs of Alex-
andria, and remained without king or bishop for more than
300 years {Gibbon, c. xlviL)
AcEPHAii was also the name given to the levellers in
the reign of Henry L, who are said to have been so poor
as to have no tenements, in virtue of which they might
acknowledge a superior lord.
A C E — A C H
93
AcEPHALi, or Aceptialous Persons, fabulous monsters,
described by some ancient natiiralists and geoOTanliers as
ACER. See Maple.
■ACERBI, Giuseppe (Joseph;, an Italian traveller, bprn
at Castel-Goffredo, near Mantua, on the 3d May 1773,
studied at Mantua, and devoted himself specially to i»atural
science. In 1798 he undertook a journey through Den-
mark, Sweden, Finlari and Lapland; and in the follow-
ing year he reached the North Cape, which no Italian had
previously visited- He was accompanied in the latter part
of the journey by the Swedish colonel Skioldebrand, an
e.tcellent landscape-painter. On his return Acerbi stayed
for some time in England, and published his Travels
through Sweden, &c. (London, 1802), which was translated
into German (Weimar, 1803), and, under the author's per-
sonal superintendence, into French (Paris, 1804). The
French translation received numerous corrections, but even
in this amended form the work contains' many mistakes.
Acerbi rendered a great service to Italian literature by
starting the Bihlioteca Italiana (1816), in which he
opposed the pretensions of the Academy della Crusca.
Being appointed Austrian consul-general to Egypt in
1826, he entrusted the management of the Bihlioteca to
Gironi, contributing to it afterwards a series of valuable
articles on Egypt. While in the East he obtained for the
museums of Vienna, Padua, MUan, and Pavia many
objects of interest. He returned from Egypt in 1836,
and took up his residence in his native place, where he
occupied himself with his favourite study till his death in
August 1846.
ACEKNUS, the Latinised name oy -wmcn oebastian
Fabian Klonowicz, a celebrated Polish poet, is generally
known, was born at Sulmierzyce in 1551, and died at
Lublin in 1608. He was for some time burgomaster and
president of the Jews' civil tribunal in the latter town,
where he had taken up his residence after studying at
Cracow. Though himself of an amiable disposition, his
domestic life was very unhappy, the extravagance and
misconduct of his wife driving him at last to the pubUc
hospital of Lublin, where he ended his days. He wrote
both Latin and PoUsh poems, and the genius they dis-
played won for him the name of the Sarmatian Ovid.
Tlie titles of fourteen of his works are known; but a
number of these were totally destroyed by the Jesuits and
a section of the Polish nobility, and copies of the others
are for the same reason exceedingly rare. The Victoria
Deonim, ubi continetur Veri Eerois Educatio, a poem in forty-
four cantos, cost the poet ten years' labour.
ACERRA, in Antiquity, a little box or pot, wherein were
put tha incense and perfumes to be burned on the altars of
the gods, and before the dead. It appears to have been
the same with what was otherwise called ihmihulum and
pyxis. The censers of the Jews were acerras ; and the
Romanists still retain the use of acerra: under the name
of incense pots.
The name acerra was aiao applied to an altar erected
among the Romans, near the bed of a person recently de-
ceased, on which his friends offered incense daily till his
burial. The real intention probably was to fumigate the
apartment The Chinese have still a somewhat similar
custom.
ACERRA, a town ot italy, in tne province of Terra
di Lavoro, situated on the river Agno, 7 miles N.E. of
Naples, with which it is connected by raiL It is the an-
cient Acerrae, the inhabitants of which were admitted to
the privileges ot Roman citizenship so early as 332 B.C.,
and which was plundered and burnt by Hannibal during
the second Punic war. A few inscriptions are the only
traces time haa left of the ancient city. _ Tho town stands
in a fertile distcict, but is rendered veiy unhealthy by the
malaria rising from the artificial water-courses of the sur-
rounding Campagna. It is the seat of a bishop, and haa a
cathedral and seminary. Flax is grown in the neighbour-
hood. Population, 11,717.
ACETIC ACID, one of the mosL important organic acids.
It occurs naturally in the juice of many plants, and in cer-
tain animal secretions ; but is generally obtained, on the
large scale, from the oxidation of spoiled wines, or from the
destructive distillation of wood. In the former process it
.is obtained in the form of a dilute aqueous solution, in which
also the colouring matters of the wine, salts, &c., are dis-
solved ; and this impure acetic acid is what we ordinarily
term vinegar. The strongest vinegar sold in commerce
contains 5 per cent, of real acetic acid. It is used as a
mordant in calico-printing, as a local irritant in medicine,
as a condiment, and in the preparation of various acetates,
varnishes, &c Pure acetic acid is got from the distillation
of wood, by neutralising with lime, separating tho tarry
matters from the solution of acetate of lime, evaporating
off the water, and treating the dry residue with sulphuric
acid. On appljring heat, pure acetic acid distills over as
a clear liquid, which, after a short time, if the weather
is cold, becomes a crystalline mass known by the name of
Glacial Acetic Acid. For synthesis, properties, &c., see
Chemibtey.
ACH-'\.I.4, in Ancient Geograpny, a name differently
appUed at diit'erent periods. In the earliest times the name
was borne by a small district in the south of Thessaly, and
was the first residence of the Achasans. At a later period
Achaia Propria was a narrow tract of country in the north
of the Peloponnesus, running 65 miles along the Gulf of
Corinth, and bounded by the Ionian Sea on the W., by
EUs and Arcadia on the S., and by Sicyonia on the E.
On the south it is separated from Arcadia by lofty moun-
tains, but the plains between the mountains and the sea are
very fertile. Its chief town was Patra?. The name of
Achaia was afterwards employed to denote collectively the
states that joined the Achcean League. When Greece was
subdued by the Romans, jfcAata was the name given to the
most southerly ot the provinces into which they divided the
country, and included the Peloponnesus, the greater part of
Greece Proper, and the islands.
Achceans and the AckcEan League. — The early inhabitants
of Achaia were called Achceam. The name was given also
in those times to some of the tribes occupying the eastern
portions of the Peloponnesus, particularly Argos and Sparta.
Afterwards the inhabitants of Achaia Propria appropriated
the name. This republic was not considerable, in early times,
as regards either the number of its troops, its wealth, or
the extent of its territory, but was famed for its heroic
virtues. The Crotonians and Sybarites, to re-establish
order in their towns, adopted tho laws and customs of
the Achseans. After the famous battle of Leuctra, a dif-
ference arose betwixt the Lacedaemonians and Thebant,
who held the virtue of this people in such veneration, thai
they terminated the dispute by their decision. The govern-
ment of the Achajans was democratical. ITiey preserved
their liberty till the time of Philip and Alexander; but in
tho reign of these princes, and afterwards, they wcro either
masters of Greece, or oppressed by domestic tyrants. The
Achaean commonwealth consisted of twelve inconsiderable
towns in Peloponnesus. About 280 years before Christ the
republic of the Achaeans recovered its old institutions and
unanimity. This was the renewal of tho ancieiit confede-
ration, which subsequently became so famous under the
name of the Acn.EAN League — having for its object, not
as formerly a common worship, but a substantial political
union. Though dating from the yea-r B.C. 280, its import-
94
A C H — A C H
ance maybe referred to its connection with Aratiw of Sicycn,
about 30 years later, as it was further augmented by the
splendid abilities of PhUopoemen. Thus did ihis people, so
celebrated in the hcroid age, once more emerge from com-
parative obscurity, and become the greatest among the states
of Greece in the last days of its national independence. The
inhabitants of Patrse and of DjTne were the first assertors of
ancient liberty. The tyrants were banished, and the towns
again made one commonwealth. A public council was then
held, in which affairs of importance were discussed and deter-
mined ; and a register was provided for recording the trans-
actions of the counciL This assembly had two presidents,
who were nominated alternately by the different towns.
But instead of two presidents, they soon elected but one.
Many neighbouring towns, which admired the constitution
of this republic, founded on equality, liberty, the love of
justice, and of the public good, were incorporated with the
Achieans, and admitted to the full enjoyment of their
laws and privileges. The Achaean League afl'ords the most
perfect example in antiquity of the federal form of govern-
ment; and, allowing for difference of time and place, its
resemblance to that of the United States government is
very remarkable. (See Arts. AMrniCTYONY and Fedkkal
GovEitNMENT; also Freeman's Federal Government, 2 vols.
8vo. 1863, and Comparative Politics, 8vo. 1873; Droysen,
Getchichte dcs Hellenismus, 2 vols. ; Helwing, Geschichte
del Ar.hauchen. Bundes.)
ACHAN, the son of Carmi, of the tribe of Judah, at
the taking of Jericho concealed two hundred shekels of
silver, a Babylonish garment, and a wedge of gold, con-
trary to the express command of God. This sin proved
fatal to the Israelites, who were repulsed at the siege of
Ai. In this emergency Joshua prostrated himself before
the Lord, and begged that he would have mercy upon his
people. Achan was discovered by .casting lots, and he
and his children were stoned to deatL This expiation
being made, Ai was taken by stratagem. (Josh. vii. viii.)
ACHARD, Franz Cam,, a Prussian chemist, bom at
Berlin on the 28th April 1753, was the first to turn
Marggraff's discovery of the presence of sugar in beet-root
to commercial account. He erected a factory on an estate
in Silesia, granted to him about 1800 by the king of Prussia,
_ and produced there large quantities of sugar to meet
the scarcity occasioned by the closing of the West Indian
ports to continental traders. In 1812 a similar establish-
ment was erected by Napoleon at Rambouillet, although
the Institute of France in 1800, while honouring Achard
for his researches, had declared his process to have little
practical value. At the close of the war the manufacture
of beet-root sugar was protected by duties on other sugars
that were almost prohibitive, so that the real worth of
Achard's discoveries could not be tested. Achard was a
frequent contributor to the Memoirs of tlie Academy of Berlin,
and published in 1780 Ckymisch-Physiscke Schriften, con-
taining descriptions and results of his very numerous and
carefully conducted experiments on the adhesion of bodies.
He died in 1821.
ACHAMUSj Erik, a Swedish physician and botanist,
born at Gefle in 1757. The son of a comptroller of
customs, he studied first in his native town, and then in
1773 at the University of Upsal, where Linnaus was one
of his teachers. In 1782 he took the degree of M.D. at
the University of Lund, and practised thereafter in various
districts of Sweden. But the direction of his studies had
been determined by his contact with Linnaeus, and he
found his appropriate sphere when he vras appointed
Academy at Stockholm. He devoted himself to the study
of the cryptogamic orders of plants, and especially of the
family of lichens. All his publications were connected
with this subject, the Lichmographia Univrrtalis (Gc't-
tingen, 1804) being the most important Acharius died
of apoplexy in 1819. His name has been given by
botanists to more than one species of plants.
ACHATES, the faithful friend and companion of JJncns,
celebrated in Virgil's jEneid as Adus Achates.
ACHEEN. See Ach{n.
ACHELOUS, the largest river in Greece, rises in Mount
Pindus, and dividing .^tolia from Acamania, falls into
the Ionian Sea,. In the lower part of its course the river
winds in an extraordinary manner through very fertile but
jnarshy plains. Its water descends from the mountains,
heavily charged with fine mud, which is deposited along
its banks and in the sea at its mouth, where a number of
small islands have gradually been formed. It was formerly
called Thoas, from its impetuosity in its upper portion, and
Homer gave it the name of king of rivers. It has a course
of 130 miles. The epithet Acheloius is used for aqveus
(Virgil), the ancients calling all water Achelous, according
to Ephorus. The river is now called Aspro Potamo.
ACHENWALL, Goitfhied, a German writer, cele-
brated as ha^^ing formulated and developed the science
( Wissenechaft der Staaten), to which he was the first to
apply the name scientia statistica, or statistics. Born at
Elbing, in East Prussia, in October 1719, he studied at
Jena, Halle, and Leipsic, and took a degree at the last-
named university. He removed to Marburg in 1746,
where for two years he read lectures on history, and on the
law of nature and of nations. Here, too, he commenced
those inquiries in statistics by which his name became
known. In 1748, having been invited by Munchhausen,
the Hanoverian minister, to occupy a chair at the univer-
sity, he removed to Gcittingen, where he resided till his
death in 1772. His chief works were connected with
statistics. The Statitsverfassunffen der europdischen Reiclte
appeared first in 1752, and revised editions — corrected
from information which he . travelled through England,
France, and other countries to collect^were published in
17G2 and 1768. He was married in 1752 to a lady
named Walther, who obtained some celebrity by a volume
of poems published in 1750, and by other writings.
ACHERON, in Classical MyOiology, the son of Ceres,
who, for supplying the Titans with drink when they were
in contest with Jupiter, was turned into a river of Hades,
over which departed souls were ferried on their way to
Elj'sium. The name eventually was used to designate the
whole of the lower world.
ACHILL, or " Eagle" Island, off the west coast of Ire-
land, forms part of the count}- of Mayo. It is of triangular
shape, and extends 15 miles from east to west, and 12
from north to south, its total area being 51,521 acres.
The island is very mountainous; its extreme western point,
Achill Head, is a bold and rugged promontory rising to a
height of 2222 feet above the sea. Large bogs, incapable
of cultivation, alternate with the hills of this desolate isle,
of whose extensive surface not more than 500 acres have
been reclaimed. The inhabitants earn a scanty subsistence
by fishing and tillage ; their dwellings are miserable
hovels. There is a mission-station on the island, and
remains of ancient churches are stiQ extant
ACHILLES ('AxtUa;s). When first taken up by the
legendary history of Greece, the ancestors of Achilles were
settled in Phthia and in jEgina. That their original seat,
however, was in the neighbourhood of Dodona and the
Achelous is made out from a combination of the following
facts: That in the Iliad (xvi 233) Achilles prays to Zeus
of Dodona; that this district was the first to bear the
name of Hellas ; that the followers of Achilles at Troy were
the only persons named Hellenes in the time of Homer
A G H — A C H
95
(ThucyiL i .3 ; of. Iliad, ii 684, where tte more usual name
of Myrmidones also occurs) ; that in jEgina Zeus was styled
"Hellanios;" and that the name of SeDoi, applied to the
priesthood at Dodona, is apparently identical with the name
Hellenes. \\Tiether from this local connection the derivation
of the name of Achilles from the same root as 'A;^e,Vu)os
should be preferred to the other derivations, such as
'A^t-kcvi = 'Ex^lXacK, " ruler," or 'A^-iXii^, — " the bane of
the rUans," remains undecided. But this is gained, that we
see in what manner the legend of Achilles had its root in
the earlier Pelasgic religion, his adherence to which in the
prayer just cited would otherwise appear very strange on
the part of a hero who, through the influence of Homer and
his successors, is completely identified with the Olympian
system of gods. According to the genealogy, J^acus had
two sons, Peleus and Telamon, of whom the former became
the father of AchiUes — the latter, of Ajas ; but of this
the Iliad. - Peleus ruled in Phthia ; and the gods remark-
ing his piety, rewarded him with, among other presents, a
wife in the person of the beautiful nereid Thetis. After
her son was born, Thetis appears to have returned to her
life in the sea. The boy was placed under his father's
friend, the centaur Cheiron. '^Tien six years old he slew
lions and boars, and could run down a stag. When nine,
he was removed from his instructor to the island of Scyrus,
where, dressed as a girl, he was to be brought up among
the daughters of Lycomedes, his mother preferring for
him a long inglorious life to a brief but splendid career.
The same desire for his safety is apparent in other legends,
which describe her as trying to make him invulnerable
when a child by placing him in boUing water or in a fire,
and then salving him with ambrosia ; or again, in later
story, by dipping him in the river Stj's, from which he
came out, all but the heel which she held, proof against
wounds. When the aid of Achilles was found indispensable
to the expedition against Troy, Odysseus set out for Scyrus
as a pedlar, spread his wares, including a shield and spear,
before thg king's daughters, among whom was Achilles
in disguise. Then he caused an alarm of danger to be
Bounded, upon which, while the girls fled, Achilles seized
the arms, and thus revealed himself. Provided with a
contingent of 50 ships, and accompanied by the aged
Phoenix and Patroclus, he joined the expedition, which
after occupying nine years in raids upon the towns in the
neighbourhood of Troy and in Mysia, as detailed in the
epic poem entitled the Cypria, culminated in the regular
siege of Troy, as described in the Iliad, the grand object
of which is the glorification of our hero. Estranged from
from him, Achilles remained inexorable in his tent, while
defeat attended the Greeks. At length, at their greatest
need, he yielded so far as to allow Patroclus to ta.ke his
chariot and to assume his armour Patroclus fell, and
the news of his death roused Achilles, who, now equipped
with new armour fashioned by Hephaestus, drove back the
Trojans, slew Hector, and after dragging his body thrice
round the Trojan walls, restored it to Priam. With the
funeral rite? of Patroclus the Iliad concludes, and the story
is taken up by the ^ihiopis, a poem by Arctinus of Miletus,,
in which is described the combat of AchiUes first with the
amazon Penthesilca, and next with Memnon. When the
latter fell, Achilles drove back the Trojans, and, impelled
by fate, himself advanced to the Scaean gate, where an
arrow from the bow of Paris struck his vulnerable heel,
and he fell, bewailed through the whole camp. (a. 3. M.)
ACHILLES TATIUS, a Greek writer, born at Alexan-
dria. The precise time when he flourished is uncertain, but
it cannot have been earlier than the 5th century, as in his
principal work he evidently imitates Heliodorus. Suidas,
who caUs him AchiUes Statins, says that he was converted
from heathenism and became a Christian bishop, but this
is doubtful, the more so that Suidas also attributes to him
a tv-ork on the sphere (irtpi <r</)ai'pas) which is referred to
by Firmicus (330-50), and must, therefore, have been
written by another person. The erotic romance of AchiUes
Tatius, entitled The Loves of ClitophoR and Leucippe, is
almost certainly the work of a heathen WTiter. The style
of the work is ornate and rhetorical, while the story is
often unnatural, and sometimes coarse, and the develop-
ment of the plot irregular and frequently interruptei Its
popularity at the time it appeared is proved by the maiq;
manuscripts of it which stiU. exist, and the value attached
to it by modern scholars and critics is seen in the frequency
with which it has been reprinted and translated. A Latin
translation by Annibal Crucceius was published, first in
part at' Leyden in 1544, and then complete at Basel in
155-4. The Greek text was first printed by Commelin, at
Heidelberg, in 1 601. Other editions by Salmasius (Leyden,
16401, MitscherUch (Biponti, 1792), and Jacobs (Leipsic,
1821), have been superseded by the editions of Hirschig
(Paris, 1856), and Hercher (Leipsic, 1857).. An EngUsh
translation by A. H. (Anthony Hodges) appeared at
Oxford in 1638.
ACHILLINI, Alexanbee (1463-1512), a naiive of
Bologna, was celebrated as a lecturer both in medicine and
in philosophy, and was styled the second Aristotle. He and
Mundinus were the first at Bologna to avail themselves of
the permission given by Frederick EL to dissect dead
bodies. His phUosophical works were printed in one
volume foUo, at Venice, in 1508, and reprinted with con-
siderable additions in 1545, 1551, and 1568. He also
wrote several medical works, chiefly on anatomy.
ACHIN (pronounced Atcheen), a town and also a state of
Northern Sumatra; the one state of that island which has
been powerful at any time since the discovery of the Cape
route to the East, and the only one that stiU remains indepen-
dentof the Dutch, though that independence is nowmenaced.
De Barros names Achln among the twenty-nine states
that divided the sea-board of Sumatra when the Portuguese
took Malacca. Northern Sumatra had been visited by
several European traveUers in the Middle Ages, such as
Marco Polo, Friar Odorico, and Nicolo ContL Some of
these as weU as Asiatic writers mention Lambri, a state
which must have nearly occupied the position of Achfn.
But the first voyager to visit Achln, by that, name, was
Alvaro TeUez, a captain of Tristan d'Acunha's fleet, in
-1506. It was then a mere dependency of the adjoining
state of Pedir; and the latter, with Pasei, formed the only
states 'on the coast whose chiefs claimed the title of Sultan.
gained independence, but had swaUowed up aU other states
of Northern Sumatra. It attained its climax of power in
the time of Sultan Iskandar Muda (1607-1636), under
whom the subject coast extended from Am opposite
Malacca round by the north to Padang on the west coast,
a sea-board of not less than 1100 mUes ; and besides this,
the king's supremacy was owned by the large island of
Nyds, and by the continental Malay states of Johor,
Pihing, Quedah, and Perdk.
The present limits of Achfn lupremacy in isumatra are
retkoced tcf be, on the east coast the River Tamiang, in
about 4° 25' N. lat., which forms the frontier of territories
tributary to Sidk; and on the west coast a line in about
2° 48' N., the frontier of Trumon, a smaU modern state
lying between Achln and the Dutch government of Padang.
Even within these limits the actual power of Achln is p.re-
carious, and the interior boundary can be laid down only
from conjecture. This interior couutrj' is totaUy unex-
plored. It is believed to be inhabited by tribes kindred
ye
A C H I N
to the Battas, that remarltablo race of anthropophagi who
adjoin on the soutli. The whole area of Acliin territorj-,
defined to the best of our ability, will contain about 10,400
English square milesi. A rate of 20 per square mile, per-
haps somewhat too largo an average, gives a probable
population of 328,000.
The production of rice and pepper forms the chief
industry of the Achin territory. From Pcdir and other
ports on the north coast largo quantities of betel-nut are
exported to continental India, to Burmah, and to Penang
for China. Some pepper is got from Pedir, but the chief
export is from a number of small ports and anchorages on
the west coast, where vessels go from port to port making
up a cargo. Achin ponies are of good repute, and are
exported. Slinor articles of export are sulphur, iron,
sappan-wood, gutta-percha, damnier, rattans, bamboos,
benzoin, and camphor from the interior forests. The
camphor is that from the Dryahalanops camphora, for
which so high a price is paid in China, and the whole goes
thither, the bulk of that whole being, however, extremely
small Very little silk is now produced, but in the 16th
century the quantity seems to have been considerable.
\Vhat is now wanted for the local textures, which are in
some esteem, is imported from China.
The chief attraction to the considerable trade that existed
at Achin two centuries ago must have been gold. No
place in the East, unless Japan, was so abundantly sup-
pUed with gold. AVe can form no estimate of the annual
export, for it is impossible to accept Valentyn's statement
that it sometimes reached 80 bahars (512,000 ounces !).
Crawford (1820), who always reckoned low, calculated the
whole export of Sumatra at 35,530 ounces, and that of
Achin at 10,450; whilst Anderson (1S26), who tends to
put figures too high, reckoned the whole Achfn export
alone at 32,000 ounces. The chief imports to Achin are
opium (largely consumed), rice (the indigenous supply
being imidequato), salt, iron ware, piece-goods, arms and
ammunition, vessels of copper and pottery, China goods of
sorts, and a certain kind of dried fish.
The great repute of Achin at one time as a place of
trade is shown by the fact, that to this port the first Dutch
(1599) and first English (1602) commercial ventures to
the Indies were du-ected. Lancaster, the English com-
modore, carried letters from Queen Elizabeth to the king
of Achfn, and was well received by the prince then reign-
ing, AlAuddin ShJih. Another exchange of letters took
place between King James I. and Iskandar Mudain 1613.
But native caprice and natural jealousy at the growing
force of the European nations in those seas, the reckless
rivalries of the latter and their fierce desire for monopoly,
were alike destructive of sound trade; and the English
factory, though several times set up, was never long main-
tained. The French made one great effort under Beaulieu
(1621) to establish relations with Achfn, but nothing
came of it.
Still the foreign trade of Achfn, though subject to spas-
modic inten-uptions, was important. Dampier and others
speak of the number of foreign merchants settled there, —
English, Dutch, Danes, Portuguese^ Chinese, Banyans
from Guzcrat, &c. Dampier says the roads were rarely
without ten or fifteen sail of different nations, bringing
vast quantities of rice, as well as silks, chintzes, muslins,
and opium. Besides the Chinese merchants settled at
Achfn, others used to come annually with the junks, ten
or twelve in number, which arrived in June. A regular
fair was then established, which lasted two months, and
was known as the China camp, — a lively scene, and great
resort of foreigners.
The A.chluese are not identical with the Malays proper
either in aspect or language. Thpy are said to be taller.
handsomer, and darker, aa if with a mixture of blood from
India proper. Their language is little known; but though
it baa now absorbed much Malay, the original part of it ia
said to have characteristics connecting it both with the
Eatta and with the Indo-Chinese tongues. The Achfn
literature, however, is entirely ilalay; it embraces poetry,
a good deal of theology, and several chronicles.
The namo of the state Ls properly AduK This the
Portuguese made into Acfiem; whilst we, with the Dutch,
learned to call it Achin. The la.'jt appears to have been a
Persian or Indian form, suggested by jingling analogy with
MAcUn (China).
The town itself lies very near the north-west extremity
of Sumatra, known in charts as Achin Head. Hero s
girdle'of ten or twelve small islands afforoa protection to
the anchorage. This faib in N.W. winds, but it is said
that vessels may find safe riding at all seasons by shifting
their berths. The town lies between two and three miles
from the sea, chiefly on the left bank of o river of no great
size. This forms a sv/ampy delta, and discharges by threo
mouths. The central and chief mouth is about 100 yards
wide, and has a depth of 20 to 30 feet within the bar.
But the latter has barely 4 feet at low tide; at high tida
it admits native ci'aft of 20 or 30 tons, and larger craft in
the rainy season. The town, like most Malay towns, con-
sists of detached houses of timber and thatch, clustered in
enclosed groups called kamjKmga, and buried in a forest of
fi-uit-trees. The chief feature is the palace of -the Sultan,
.which communicates with the river by a canal, and ia
enclosed, at least partially, by a wall of cut stone.
The valley or alluvial plain in which Achfn lies is low,
and subject to partial inundation; but it is shut in at a
short distance from the to^vn, on the three landward sides,
by hills. It is highly cultivated, and abounds in small
villages and kampongs, ■with white mosques interspersed.
The hills to the eastward are the spurs of a great volcanic
mountain, upwards of 6000 feet in height, called by natives
Yamuria, by mariners " the Golden Mountain." ^ Of the
town population we find no modem estimate.
The real original territory of the Achfnese, called by
them Great Achfn (in the sense of Achfn proper), consists
of threo districts immediately round the city, distinguished
respectively as the 26, the 25, and the 22 miikima' (or
hundreds, to use the nearest English term).
Each of these three districts has two heads, called pomg-
limas; and these, according to some modem accounts,
constitute the council of state, who are the chief adminis-
trators, and in whose hands it lies to depose the sovercigu
or to sanction his choice of a successor. Late notices
speak of a chief minister, apparently distinct from these;
and another important member of fhe government is the
Shdbandar, who is over all matters of customs, shippirg,
and commerce.
The court of Achfn, in tne 17th century, maintained a
good deal of pomp; and, according to Beaulieu, the king
had always 900 elephants. These animals, though found
throughout Sumatra, are now no longer tamed or kept.
Hostilities with the Portuguese began from the time of
the first independent king of Achfn; and they had little
remission tUl the power of Portugal fell with the loss of
Malacca (1641). Not less than ten times before that
event were armaments despatched from Achin to reduce
Malacca, and more than once its garrison was very hard
pressed. One of these armadas, equipped by Iskandar
Muda in 1615, gives an idea of the king's resources. It
consisted of 500 sail, of which 250 were galleys, and
* Several other great Tolcanic cones eii^t in the AcMn territory, axul
two visible from seaward rise to a height of 11,000 feet or more in ths
unexplored interior.
' A miikini is said prooc-rlv xo emoroca 44 household
A C H — A C I
97
among these a hundred were greater than any tnen used in
Europe. 60,000 men were embarked, with the king and
his women.
On the death of Iskandar's successor in 1641, the widow
was placed on the throne; and as a female reign favoured
the oligarchical tendencies of the Malay chiefs, three more
queens were allowed to reign successively. Though this
series of female sovereigns lasted only fifty-eight years alto-
gether, so dense is apt to be the ignorance of recent history,
that long before the end of that period it had become an
accepted beUef among foreign residents at Achfn that there
never had been any sovereigns in Achin except females;
and hence, by an easy inference, that the Queen of Sheba
had been Queen of Achin !
In loy9 the Arab or fanatical party suppressed female
government, and put a chief of Arab blood on the throne.
The remaining history of Achin is one of lapid decay.
Thirty sovereigns in all have reigned from the beginning
of the 16th century to the present day.
After the restoration of Java to the Netherlands in 1816,
a good deal of weight was attached by the neighbouring
English colonies to the maintenance of our influence in
Achin; and in 1819 a treaty cf friendship was concluded
with the Calcutta Government, which excluded other
European nationalities from fixed residence in Achfn.
When the home Government, in 1824, made a treaty with
the Netherlands, surrendering our remaining settlements
in Sumatra in exchange for certain possessions on the con-
tinent of Asia, no reference was made in the articles to the
Indian treaty of 1819; but an understanding was exchanged
that it should be modified by us, whilst no proceedings
hostile to Achin should be attempted by the Dutch.
This reservation was formally abandoned by our Qovern-
ment in a convention signed at the Hague, November 2,
1871; and little more than a year elapsed before the
government of Batavia declared war upon Achfn. Doubt-
less there was provocation, as there always will be between
such neighbours; but the necessity for war has been
greatly doubted, even in Holland. A Dutch force landed
at Achfn in April 1873, and attacked the palace. It was
defeated with considerable loss, including that of the
general (Kbhler). The approach of the south-west mon-
soon was considered to preclude the immediate renewal of
the attempt ; but hostilities were resumed, and Achin fell
in January 1874. ,
(De Barros; Faria y Souza; Valentyn, vol. v.; Beaulieu
(in Th^venot's Collection); Dampier; Marsden; Crawfurd's
Hist, and Decl. of the Ind. Archip.; J. of Ind. Archip.;
Dulaurier in J. Asiatique, 3d s. vol viii.; Anderson's Acheen,
1840; Veth, Atchtn, &.c. Leyden, 1873, &c.) (h. y.)
ACHMET, or Ahmed, the name of three emperors or
sultans of Turkey, the first of the name reigning from 1603
to" Ml 7, the second from 1691 to 1695. Achmet III.
succeeded his brother Mustapha II., whom the Janissaries
deposed in 1703. After the battle of Pultowa in 1709,
Charles XII. of Sweden took refuge with him, and incited
him to war with Peter the Great, Czar of Russia. Achmet
recovered the Morea from the Venetians (1715); but his
expedition into Hungary -was less fortunate, his army being
defeated at Peterwardein by Prince Eugene in 1716, and
again near Belgrade the year after. The empire was dis-
tracted during his reign by political disturbances, which
were occasioned, in part at least, by his misgovemment ;
and the discontent of his feoldiers at last (1730) drove him
from the throne. He died in pri.son in 1736.
ACHRAY, a small picturesque lake in Perthshire, near
Loch Katrine, 20 miles W. of Stirling, which has obtained
notoriety from Scott's allusion to it in the Lady of the Lake.
ACHROMATIC GLASSES are so named from being
Bi>ecially constructed with a view to prevent the confusion
1—5
of colours and distortion of images that result from the
use of lenses in optical instruments. Wben white light
passes through a lens, the different-coloured rays that con-
stitute it are refracted or bent aside at different angles, and
so converge at different foci, producing a blurred and
coloured image. To remedy this compound lenses havo
been devised, which present a well-defined image, unsur-
rounded by coloured bands of light. To instruments fitted
with lenses of this kind has been given the name achromatic,
from d privative, and )(pit)^a, colour. The celebrated opti-
cian, John Dollond, was the first to surmount this practical
difficulty, about the year 1757, by the use of a combination
of crown and flint glass. See Optics, Microscope, &c.
ACI KEALE, a city and seaport of SicUy, in the
Italian province of Catania, near the base of Mount Etna.
It stands on solidified lava, which has here been deposited
by different streams to a depth of 560 feet. The town,
which has been almost entirely re-erected since the earth-
quake of 1693, is built of lava, contains many handsome
edifices, and is defended by a fortress. Linen, silks, and
cutlery are manufactured, and the trade in cotton, flax,
grain, and wines is considerable. The place is celebrated
for its cold sulphurous mineral waters. Near Aci Eeale
is the reputed scene of the mythical adventures of Acis and
Galatea; and on this account several small towns in the
neighbourhood also bear the name of Aci, such as Aci
CasteUo, Aci Terra, &c. Aci Reale has a population of
24,151.
ACID, a general term in chemistry, applied to a
group of compound substances, possessing certain very
distinctive characteristics. All acids have one essential
property, viz., that of combining chemically with an alkali
or base, forming a new compound that has neither acid
nor alkaline characters. The new bodies formed in this
way are termed salts. Every acid is therefore capable of
producing as many salts as there are basic substances to be
neutralised; and this salt-forming power is the best de-
finition of an acid substance. •
The majority of acids possess tne following contingent
propenies : —
1. When applied to the tongue, they excite that sensation
■which is called sour or acid.
2. They change the blue colours of vegetables to a red.
The vegetable blues employed for this purpose are generally
tincture of htmus and syrup of violets or of radishes, which
have obtained the name of re-agents or tests. If these
colours have been previously converted to a, green by alkalies,
the acids restore them.
All these secondary properties are variable; and if we
attempted to base a definition on any one of them, many
important acids would be excluded. Take the case of a
body like silica, so widely difl'used in nature. Is pure
silicious sand or flint an acid or a neutral substance 1 When
it is examined, it is found to be insoluble in water, to be
devoid of taste, and to possess no action on vegetable colour-
ing matters; yet this substance is a true acid, because when
it is heated along with soda or lime, it forms the new body
commoiJy called glass, which is chemically a salt of silicic
acid. Many other acids resemble silica in properties, and
would be mistaken for neutral bodies if the salt-forming
power was overlooked.
Another method of regarding an acid, which is found of
great importance in discussing chemical reactions, is to say
an acid is a salt whose base is water. This definition is
very apparent if we regard what takes place in separating
the acid from a salt. In this decomposition the acid would
appear to be left without having any substitute for tha
removed alkalL This is not however the case, as water is
found to enter into union instead of the base. Thus every
true acid most contain hydrogen; and if this is 'displaced
I- — 13
t)8
A C I — A C O
by a metal, salts are formed directly. An acid is there:
fore a salt, whoso metal is hydrogen. The full importance
of the definition of an acid will be learned under the head-
ing Chemistry.
ACIDALIUS, Valens, a very distinguished scholar
end critic, born in 1567 at Witt.stock, in Brandenburg.'
After studying at Rostock and Ilelmataedt, and residing
about three years in Italy, ho took up his residence at
Breslau, where he professed the Roman Catholic religion.
His excessive application to study was supposed to have
caused his untimely death, which occurred in 1095, when
he had just completed his twenty-eighth year. He wrote
notes on Tacitus and Curtius, a commentary on Plautus,
and a number of poems, which are inserted in the Dclicics
of the Gorman poets. BaiUct gave him a place among his
Enfarui Celebrea, and tells that he wrote the commentary
on Plautus and several of the Latin poems when he was
only seventeen or eighteen years of ago.
ACINACE.S, an ancient Persian sword, short and
straight, and worn, contrary to the Roman fashion, on the
right side, or sometimes in front of the body, as shown in
the bas-reliefs found at Persepolis. Among the Persian
nobility they were frequently made of gold,- being worn aa
a badge of distinction. The acinaces was an object of
religious worsliip with the Scythians and others {Herod.
iv. 62).
ACIS, in ilylhology, the son of Faunus and the nymph
Symiethis, was a beautiful shepherd of Sicily, who being
beloved by Galatea, Polyphemus the giant was so enraged
that he crushed his rival with a rock, and his blood gush-
ing forth from under the rock, was metamorphosed into
the river bearing his name (Ovid, Met. xiii. 750; Sil. Ital.
xiv. 221). This river, now .^'jMme di Jaci,OTAeque Grandi,
rises under a bed of lava on the' eastern base of Etna, and
passing Aci Reale, after a rapid course of one mile, falls
into the sea. The waters of the stream, once celebrated
for their purity, are ifow sulphureous.
ACKERJlANN, John Christian Gottlieb, a learned
physician and professor of medicine, bom at Zeulenroda,
in Upper Saxony, in 1756. At the early age of fifteen he
became a student of medicine at Jena, where he soon
attracted the favourable notice of Baldinger, who undertook
the direction of his studies. When Baldinger was trans-
ferred to Gdttingen in 1773, Ackermann went with him,
and afterwards studied for two years at Halle. A few
years' practice at Stendal (1778-99), where there were
numerous factories, enabled him to add many valuable
original observations to his translation of Ramazzini's
Treatise of t/te Diseases of Artificers (1780-83). In 1786
ha became professor of medicine at the university of
Altorf, in Franconia, occupyiiig first the chair of chemistry,
and then, from 179-1 till his death in 1801, that of patho-
logy and therapeutics. Dr Ackermann's knowledge of the
history of medicine may be estimated by his valuable con-
tributions to Harless's edition of Fabricius' BiUiotheca
Groeca. He wrote numerous origijjal works, besides trans-
lations.
ACCEMET^E (dKoi/iT/ros, sleepless), an order of monks
instituted by Alexander, a Syrian, about the middle of
the 6th century. Founding on the precept, Pray without
ceasing, they celebrated divine service uninterruptedly night
and day, for which purpose they divided themselves into
three . sections, that relieved each other in turn. The
chief seat of the Acoemetse was the cloister Studium at
Constantinople, whence they were sometimes called Studites.
Having adopted the monophysite heresy, they were put
under the Papal ban about the year 536.
ACOLYTE (from cutoAovflos, an attendant, one of a
minor order of clergy in the ancient church, ranking
next to the sub-doacon. We leam from the canons of the
fourth Council of Carthage that the archdeacon, at their
ordination, put into their hands a candlestick with a taper
and an empty pitcher, to imply that they were appointed
to light the candles of the church and to furnish win*
for the eucharist. Their dress was the cassock and sur-
plice. The name and office still exist in the church.
ACONCAGUA, a province of Chile, South America, is
about 100 miles long by 40 miles wide, and lies between
Sr 30' and 33° 20' S. lat, and 70° and 71° 30' W. long.,
between the provinces of Valparaiso and Santiago on the N.
and Coquhnbo on the S. A large part of the province
is mountainous, but it contains several rich and fertile
valleys, which yield wheat, maize, sugar-cane, fruits, and
garden produce in abundance. In the agricultural dis-
tricts there are raised from 50 to 60 fanegas of wheat for
The province has also mineral resources, but not to such
extent as Coquimbo or Atacama. Its chief town is San
Felipe. The mountain Aconcagua, one of the loftiest
peaks of the Andes, rises to the height of 23,910 feet
above the sea on the frontier between this province and
Mendoza, a department of the Argentine Republic A
river of the same name rises on the south side of the
mountain, and after a course of 230 miles falls into the
Pacific 12 miles N. of Valparaiso. Pooulation Q870),
134,178.
ACONITE, AcONiTOM, a genus of planta commonly
known as Aconite, Monkshood, Friar's Cap, or Helmet
flower, and embracing about 18 species, chiefly natives of
the mountainous parts of the northern hemisphcra They
are distinguished by having one of the five blue or yellow
coloured sepals in the form of a helmet ; hence the English
name. Two of the petals placed under the hood of the
calyx are supported on long stalks, and have a hollow
spur at their apex. The genus belongs to the natural
order Ranunculaceae, or the Buttercup family. Aconitum
Napellus, common monkshood, is a doubtful native of
Britain. It is an energetic irritant and narcotic poison.
It causes death by a depressing effect on the nervous system,
by producing palsyof the muscles concerned in breathing, and
by fainting. A tincture prepared by the action of spirit
on the roots is used medicinally to allay pain, especially
in cases of tic. Its roots have occasionally been mistaken
for horse-radish. The Aconite has a short underground
stem, from which dark-coloured tapering roots descend. The
crown or upper portion of the root gives rise to new plants.
When put to the lip, the juice, o/ the Aconite root pro-
duces a feeling of numbness and tingling. The horse-
radish root, which belongs to the natural order Cnici-
ferse, is much longer than that of the Aconite, and it i»
not tapering ; its colour is yellowish, and the top of the
root has the remains of the leaves on it. It has a pun-
gent taste. Many species of Aconite are cultivated in
gardens, some having blue and others yellow flowers.
Aconitum Lycoctonum, Wolfsbane, is a yellow-flowered
species common on the Alps of Switzerland. One species,
Aconitum heterophyllum, found in the East Indies, and
called Butees, has tonic properties in its roots. The roots
of Aconitum ferox supply the famous Indian (Nipal)
poison called Bikh, Bish, or Nabee. This species is con-
sidered by Hooker and Thomson as a variety of Aconitum
Napellus. Aconitum palmatum yields another of the
celebrated Bikh poisons. Aconitum luridum, of the Hima-
layas, also furnishes a poison.
ACONTIUS, the Latinised form of the name of GlAqpno
AcoNCiO, a philosopher, jurisconsult, engineer, and theolo-
gian, bom at Trent on the 7th September 1492. He em-
braced the reformed religion; and after having taken refuge
for a time in Switzerland and Strasburg, he came to Eng-
A C O — A O
99
Queen Elizabeth, at whoso court, it is saia, taougli on
doubtful authority, that he resided for a considerable period.
With the sanction of Parliament, he carried on for several
years extensive works for the embankment of the Thames,
and so reclaimed a large quantity of waste land, part of
which was bestowed upon him by way of recompense. His
gratitude to Queen Elizabeth was expressed in the dedica-
tion to her of his celebrated Collection of the Stratagems of
Satan, which has been often translated, and has passed
through many editions. Various opinions have been given
of this work, which advocated toleration to an extent that
many considered indifference. The nature of its doctrine
may perhaps be best gathered from the fact that it gained
for the author the praise of Arminius, and the strong con-
demnation of the Calvinists. Acontius also wrote a treatise,
De Mcthodo, which was published at Basel in 1558. He
died in London about the yeai 15G6.
ACOPiUS, a genus of monocotyledonous plants belonging
to the natural order Aroideie, and the sub-order Orontiacete.
Acorns Calamus, sweet-sedge or sweet-flag, is a native of
Britain. It has an agreeable odour and has been used as
a strengthening remedy, as well as to aUay spasms. The
starchy matter contained in its running stem or rhizome
is associated with a fragrant oil, and it is used as hair-
powder. Confectioners form a candy from the rhizomes
of the plant, and it is also used by perfumers in preparing
aromatic vinegar.
ACOSTA, Cheistoval d', a Portuguese naturahst, born
at Jlozambique in the early part of the IGth century. On
a voyage to Asia he was taken captive by pii'ates, who
exacted from him a very large ransom. After spending
some years in India, chiefly at Goa, a Portuguese colony,
he returned home, and settled as a surgeon at Burgos.
Here he published his Tratado de las drogas y medecinas
de las Indias orientcles (1578). This work was translated
into Latin, Italian, and French, became well known through-
out Europe, and is stiU consulted as .an authority. Acosta
also wrote an account of his travels, a book in praise of
women, and other works. He died in 1580.
ACOSTA, Joseph d', a celebrated Spanish author, was
born at Medina del Campo about the year 1539. In 1571
he went to Peru as a provincial of the Jesuits ; and, after
remaining there for seventeen years, he returned to his
native country, where he became in succession visitor for
his order of Aragon and Andalusia, superior of VaUadolid,
and rector of the university of Salamanca, in which city he
died in February 1 600. About ten years before his death
he published at Seville his valuable Historia Natural y
Moral de las Indias, part of which had previously appeared
in Latin; with the title De Natttra Novi Orhis, libri duo.
This work, which has been translated into all the principal
languages of Europe, gives exceedingly valuable informa-
tion regarding the condition of South America at the time.
On the subject of climite Acosta was the first to propound
the theory, afterwards advocated by Bufl'on, which attri-
buted the different degrees of heat in the old and new con-
tinents to the agency of the winds. He also contradicted,
from his own experience, the statement of Aristotle, that
the middle zone of the earth was so scorched by the sun as
to be destitute of moisture, and totally uninhabitable. Even
after the discovery of America this AristoteUan dogma was
an article of faith, and its denial was one ground of the
charge of scepticism and atheism brought against Sir Walter
Raleigh. Acosta, however, boldly declared that what he
he could not but " laugh at Aristotle's meteors and his
philosophy." In speaking of the conduct of his country-
men, and the means they employed for the propagatioit- of
their faith, Acosta is in no resjicct superior to the other
prejudiced writers of his country and age. Though he
acKnowledges that the career of Spanish conquest was
marked by the most savage cruelty and oppression, he yet
represents this people as chosen by God to spread the gospel
among the nations of America, and recouuts a variety of
miracles as a proof of the constant interposition of Heaven
in favour of the merciless and rapacious invaders. Besides
his History, Acosta wrote the following works : — 1. De Fro-
mulgatione £vangelii apud Barbaras ; 2. De Chris'to Heve-
lato; 3. De Temporibus Novissimis, lib. vi; 4. Concionum
tomi Hi.
ACOSTA, Ukiel d', a Portuguese of noble familj', waa
born at Oporto towards the close of the ICth century.
His father being a Jewish convert to Christianity, he was
brought up in the Roman Catholic faith, and strictly ob-
served the rites of the church tiU the course of his inquiries
led him, after much painful doubt, to abandon the religion
of his youth for Judaism. Passing over to Amsterdam, ho
was received into the sjTiagogue, having his name changed
from Gabriel to Uriel. He soon discovered, however, that
those who sat in Moses' seat were shameful perverters of
the law ; and his bold protests served only to exasperate
the rabbis, who finally punished his contumacy with the
greater excommunication. Persecution seemed only to
stimulate his temerity, and he soon after pubUshed a de-
fence, Examen, das iradicocns Phariseas, iii., in which he
not merely exposed the departures of the Jewish teachers
from the law, but combated the doctrine of a future life,
holding himself supported in this position by the silence of
the Mosaic Books. For this he was imprisoned and fined,
besides incurring public odium as a blasphemer and atheist.
Nothing deterred, he pursued his speculations, which ended
in his repudiating the divine authority of the law of Moses.
Wearied, however, by his melancholy isolation, and longing
for the benefits of society, he was drivea, in the inconsis-
communion. Having recanted his heresies, he was re-
admitted after an excommunication of fifteen years, but
was soon excommunicated a second time. After seven
years of miserable exclusion, he once more sought admis-
sion, and, qn passing through a humiliating penance, was
again received. These notices of his singular and unhappy
life are taken from his autobiography, Exemplar Uumamx
Yitce, published, with a " refutation," by Limborch, and
republished in 1847. It has. been said that he died by
his own hand, but this is, to say the least, doubtful. His
eventful history forms the subject of a talc and of a tragedy
by Gutzkow.
lACOTYLEDONES, the name given to one of tne Classes
of the Natural System of Botany, embracing flowerless
plants, such as ferns, lycopods, horse-tails, mosses, Kverworts,
lichens, sea-weeds, and mushrooms. The name is derived
from the character of the embryo, which has no cotyledon.
Flowering plants have usually one or two cotyledons, that
is, seed-leaves or seed-lobes connected with their embrj'o ;
while in flowerless plants the body representing the embryo
consists of a cell, called a spore, without any leaves. The
plants have no flowers, and their organs of reproduction arc
inconspicuous, hence they are called by Linnaeus crypto-
gamous. Some flowering plants, such as dodders, have no
cotyledons ; and some have the cotyledons divided into
more than two, as in conifers. Some acotyledonous spores,
when sprouting, produce a leaf-like expansion called a pro-
thallus, on which the organs of reproduction, consisting
of antheridia and archegonia, are produced. This is well
seen in the case of ferns. In the interior of the antheri
dian cells, moving filamentous bodies, called spermatozoids,
have been observed These fertilise the archegonial cells,
whence new plants are produced. In the article Botany
these plants will be noticed under Class III. of the NaturaJ
System.
100
ACOUSTICS
DelniUon.
1. 1. \ COUSTICB (from iKovia, to hear) is that branch of
XJL. Natural Phtlosophy which treats of the nature of
Bound, and the laws of its production and propagation, in so
far as tlieso depend on phyaical principles. The description
of the mechanism of the organ of voice and of the ear, and
the difficult (questions connected with the processes by
■which, when sound reaches the drum of the car, it is trans-
mitted to the brain, must be dealt with in separate articles
of this work. It is to the physical part of the science of
acoustics that the present article is restricted.
Pakt L
»
General notions as to Vibrations, Waves, <tc.
Souml la 2. We may easily satisfy ourselves that, in every in-
line lo Btince in which the sensation of sound is excited, the body,
vibrations, whence the sound proceeds, mtist have been thrown, by a
blow or other means, into a state of agitation or tremor,
implying the existence of a vibratory motion, or motion to
and fro, of the particles of which it consists.
Thus, if a common glass-jar be struck so as to yield an
audible sound, the existence of a motion of this kind may
be felt by the finger lightly applied to the edge of the
glass ; and, on increasing the pressure so as to destroy this
motion, the sound forthwith ceases. Small pieces of cork
put in the jar will be found to dance about during the con-
tinuance of the sound ; water or spirits of wine poured into
the glass will, under the same circumstances, exhibit a
ruffled surface. The experiment is usually performed, in a
more striking manner, with a beU-jar and a number of
small light wooden balls suspeftded by silk strings to a
fixed frame above the jir, so as to be just in contact, with
the widest part of the glass. On drawing a violin bow
across the edge, the pendulums are thrown off to a con-
siderable distance, and falling back are again repelled,
It is also in many cases possible to follow with the eye
the motions of the particles of the sounding body, as, for
instance, in the case of a violin string or any string fixed
at both ends, when the string will appear, by a law of
optics, to occupy at once aU the positions which it suc-
cessively assumes during its vibratory motion.
Sound is 3. It is, moreover, essential, in order that the ear may
propagated be affected by a sounding body, that there be interposed
to Oio ear between it and the ear one ot more intermefliate bodies
by VI >ra- („i^j,'(j), themselves capable of molecular vibration, which
v„ ' shall receive such motion from the source of sound, and
transmit it to the external parts of the car, and especially
to the memlrana tympani or drum of the ear. This state-
ment is confirmed by the well-known effect of stopping the
car with soft cotton, or other substance possessing little
elasticity.
The air around us forms the most important medium of
communication of sound to our organs of hearing ; in fact,
were air devoid of this property, we should practically be
without the sense of hearing. In illustration of the part
€hu3 assigned to the atmosphere in acoustics, an apparatus
has been constructed, consisting of a glass receiver, in which
is a bell and a hammer cxannected with clock-work, by
which it can be made to strike the bell when required.
The receiver is closed air-tight by a metal plate, through
which passes, also air-tight, into the interior, a brass rod.
By jjroperly moving this rod with the hand, a detent is
released, which checks the motion of the wheel-work, and
the hammer strilvcs the bell continuously, till the detent is
pushed into its original position. As long as the air in
Ac
the receiver is of the usual atmospheric density, the sound
is perfectly audible. But on rarcfj-ing the air by means'
of an air-pujjip (the clock-work apparatus having been
separated from the plate of the pump by means of a pad-
ding of soft cotton), the sound grows gradually fainter,
and at last becomes inaudible when the rarefaction of iba
air has reached a very low point. If, however, at this
stage of the experiment, the metal rod be brought into
contact with the bell, the sound will again be heard
clearly, because now there is the necessary communication
with the ear. On readmitting the air, the sound recovers
its original intensity. This experiment was first performed
by Uawksbee in 1705.
4. Inasmuch, then, as sound necessarily implies the L»w« of
existence in the sounding body, in the air, Ac, and (we libratoiy
may add) in the ear itself, of Wbratory motion of the par- """tion.
tides of the various media concerned in the phenomenon,
a general reference to the laws of such motion is essential
to a right understanding of the principles of acoustics.
The most familiar instance of this kind of motion is
afforded by the pendulum, a small heavy ball, for instance,
attached to a fine string, which is fixed at its other end.
There is but one position in which the ball will remain at
rest, viz., when the string is vertical, there being then
equilibrium between the two forces acting on the body,
the tension of the string and the earth's attractive force or
gravity. Thus, in the adjoining fig., if C is the point of
suspension, and CA the vertical through that point of
length I, equal to the string, A is the equilibrium position
of the particle.
Let now the ball be removea from A to P, the string being
kept tight, so that P describes
the arc AP of a circle of radius
equal to I, and let the ball be
there dropped. The tension of
the string not being now directly
opposite in direction to gravity
(g), motion will ensue, and the
body will retrace the arc PA
In doing so, it will continually
increase its velocity until it
reaches the point A, where its
velocity will be a maximum, and
will consequently pass to the
other side of A towards Q. But now gravity tends to
draw it back towards A, and heuce the motion becomes
a retarded one ; the velocity continually diminishes, and
is ultimately destroyed at some point Q, which wotdd be,
at a distance from A equal to that of P, but for the
existence of friction, resistance of the air, ic, which make
that distance less. From Q it will next move down with
accelerated motion towards A, where it will have its greatest
velocity in the direction from left to right, and whence it
will pass onwards towards P, and so on. Thus the body
wiU vibrate to and fro on either side of A, its amplitude of
vibration or distance between its extreme positions gradually
diminishing in consequence of the resistances before men-
tioned, and at last being sensibly reduced to nothing, the
body then resuming its equilibrium-position A.
If the amplitude of vibration is restricted withiii incon-
siderable limits, it is easy to prove that the motion takes
place just as if the string were removed, the ball deprived
altogether of weight and urged by a force directed to the
point A, and proportional to the distance from tiat point.
For then, if m be any position of the baU, the cbcrd mA.
may be regarded as coincident with the tangent to the
Fig. 1.
ACOUSTICS
101
circle at m, and therefore as being perpendicular to Um.
Hence g, acting parallel to CA, being resolved along Cm
and m&., the former component is counteracted by the
tension of the string, and there remains as the ordy effec-
tive acceleration, the tangential component along mA,
■wticii, by the triangle of forces, is equal io g^^;— or v- Am,
and is therefore proportional to Am.
On this supposition of indefinitely small vibrations, the
pendulum is isochronous; that is, the time occupied in
passingfrom one extreme position to the other is the same,
for a given length I of the pendulum, whatever the extent
of vibration.
A\'e conclude from this that, whatever may be the nattire
of the forces by which a particle is urged, if the resultant
of those forces is directed towards a fixed point, and is
proportional to the distance from that point, the particle
will oscillate to and fro about that point in times which
are independent of the amplitudes of the vibrations, pro-
vided these are very small
5. The particle, whose vibratory motion we have been
Acoustic considering, is a solitary particle acted on by external
viljratious. forces. But, in acoustics, we have to do with the motion
of particles forming a connected system or medium, in
which the forces to be considered arise from the mutual
actions of the particles. These forces are in equilibrium
with each other when the particles occupy certain relative
positions. But, if any new or disturbing force act for a
short time on any one or more of the particles, so as to
cause a mutual approach or a mutual recession, on the
removal of the disturbing force, the disturbed particles
will, if the body be elastic, forthwith move towards their
respective positions of equilibrium. Hence arises a vibra-
tory motion to and fro of each about a given point,
analogous to that of a pendulum, the velocity at that point
being always a maximupi, alternately in opposite directions.
Thus, for example, if to one extremity of a pipe contain-
ing air were applied a piston, of section equal to th*t of
the pipe, by pushing in the piston slightly and then remov-
ing it, we should cause particles of air, forming a thin
section at the extremity of the pipe, to vibrate in directions
parallel to its axis.
In order that a medium may be capable of molecular
vibrations, it must, as we have mentioned, possess elasticity,
tion when slightly disturbed out of it.
6. We now proceed to show how the disturbance where-
Transmis- ^7 certain particles of an elastic medium are displaced from
Sinn of theii- equilibrium-positions, is successively transmitted to
vib.-iiions. the remaining particles of the medium, so as to cause these
also to vibrate to and fro.
Let us consider a line of sucn particies y, x, a, b, itc.
y X a^aa^b c d e f g h i h I m n p
equidistant from each other, as above; and suppose one of
them, say a, to be displaced, by any means, to a,. As we
have seen, this particle will swing from a, to a„ and back
again, occupying a certain time T, to complete its double
vibration. But it is obvious that, the distance between a
and the next particle h to the right being diminished by
the displacement of the former to a^, a tendency is gene-
rated in b to move towards a,, the mutual forces being
no longer in equilibrium, but having a resultant in the
direction ba^. The particle b will therefore also suffer
displacement, and bo compelled to swing to and fro about
the point b. For similar reasons the particles c, d . . .
will all likemse bo thrown into vibration. Thus it is, then,
that the disturbance propagates itself in the direction under
consideration. There is evidently also, in the case sup-
posed, a transmission from a to x, y, Sec, i.e., in the opposite
direction.
Confining our attention to propagation in the direction
abc . . ., we have next to remark that each particle in that
line will be affected by the disturbance always later than
the particle immediately preceding it, so as to be found in
the same stage of vibration a certain interval of time, after
the preceding particle.
7. Two particles which' are in the same stage of vibra- tuase
tion, that is, are equally displaced from their equDibrium-
positions, and are moving in the same direction and with
equal velocities,- are said to be in the same phase. Hence
we may express the prfeceding statement more briefly thus :
Two particles of a disturbed medium at different distances
from the centre of disturbance,- are in the same phase at
different times, the one whose distance from that centre is
the greater being later than the other.
8. Let us in the meantime assume that, the intervals
ah, be, cd . . . . being equal, the intervals of time which
elapse between the like phases of b and a, of c and b . . . ,
are also equal to each other, and let us consider what at
any given instant are the appearances presented by the
different particles in the row.
T being the time of a complete vibration of each particle,
let — be the interval of time requisite for any phase of a
to pass on to b. If then at a certain instant a is displaced
to its greatest extent to the right, b will be somewhat short
of, but moving towards, its corresponding position, c still
further short, and so on. Proceeding in this way, we shall
come at length to a particle p, for which the distance
ap=p. ab, which therefore lags in its vibrarions behind a
T
by a time = ;d x — = T, and is consequently precisely in
the same phase as a. And between these two particles
a, p, we shall evidently have particles in all the possible
phases of the vibratory motion. At h, which is at distance
from a'=iap, the difl'erence of phase, compared with a,
■n-ill be AT, that is, h will, at the given instant, be dis-
placed to the greatest extent on the opposite side of its
equilibrium-position from that in which a is displaced; in
other words, A is in the exactly opposite phase to a.
9. In the case we have just been considering, the vibra- Longitu
tions of the particles have been supposed to take place in '•'"»' ""•'
a direction coincident with that in which the disturbance''"' '
passes from one particle to another. The vibrations are
then termed longitudinal.
But it need scarcely be observed that the vibrations may
take place in any direction whatever, and may even be
curvilinear. If they take place in directions at right
angles to the lino of progress of the disturbance ^ they are
said to be transversal.
10. Now the reasoning employed in the preceding case Wave of
will evidently admit of general application, and wil), in <ransTera»l
particidar, hold for transversal vibrations. Hence if we I'f})!^'^''
mark (as is done in fig. 2) the positions Oj 6, c, . . ., occupied
by the various particles, when swinging transversely, at the
instant at -which a has its maximum displacement above its
equilibrium-position, and trace a continuous line running
through the points so found, that line will by its ordinates
indicate to the eye the state of motion at the given 'nstauti
VCTS.!)
vibr.atiouk.
ments.
5-^--*
Fig. 2.
Thus a and p are in the same phase, as are also h and
y, c and r, itc. a and h are in opposite phases, as are also
aud i, c and k, ikc.
102
ACOUSTICS
Distances ap, bq, &c., separating particles in the same
phase, and each of which, as we have seen, is passed over
by the disturbance in the time T of a complete vibra-
tion, include within them all the possible phases of the
motion.
Beyond this distance, the curve repeats itself exactly,
that is, the phases recur in the same order as before.
Now the figure so traced offtrs an obvious resemblance
to the undulating surface of a lake or other body of water,
after it has been disturbed by wind, exiiibiting a wave
with its trough A/i,B, and its c^est Bpfi. Hence have
been introduced into Acoustics, as also into Optics, the
terms wave and undulation. The distance ap, or bq . . .
or A-C, which separates two particles in same phase,
or which includes both a wave-crest and a wave-trough,
is termed the lenr/lh of the tvave, and is usually denoted
byX.
As the curve repeats itself at intervals each ■= X, it
follows that particles are in the same phase at any given
niomcut, when the distances between them in the direction
of transmission of the disturbance = A, 2X, 3A . . . and gena-
ully = n\, where n is any whole number.
Particles such as a and A, 6 and i, ic, which are at
distances = -\ , being in opposite phases, so will also be
1 3
particles separated by distance, -X-fX= -X, or, in general,
by -X -I- »nX = (2m -f 1 ); , that is, by any odd multiple of - .
Wave oi 11. Alike construction to the one just adopted for the
velocities, displacements of the particles at any given instant, may be
also applied for exhibiting graphically their velocities at
the same instant. Erect at the various points a, 6, c, ic,
perpendiculars to the line joining them, of lengths pro-
portional to and in the direction of their velocities, and
draw a line through the extreme points of these perpendi-
culars; this line will answer the pi(rpose required. It is
indicated by dots in the previous figure, and manifestly
forms a wave of the same length as the wave of displace-
ments, but the highest and lowest points of the one wave
correspond to the points in which the other wave crosses
the line of equilibrium.
VtoTc» ibr 12. In order to a graphic representation of the displace-
longitu- menta and velocities of particles vibrating longitudinally,
dinal vilira- j{ jj convenient to draw the lines which represent those
°^^' quantities, not in the actual direction in which the motion
takes place and which coincides with the line ab c . . ., but
at right angles to it, ordinates drawn upwards indicating
displacements or velocities to the right (i.e., in the direc-
tion of transmission of the disturbance), and ordinates
drawn downwards indicating displacements or velocities in
the opposite direction. ^Vhen this is done, waves of dis-
placement and Telocity are figured identically with those
for transversal vibrations, and are therefore subject to the
same resulting laws,
fropaga- 13. But not only will the above waves enable us to see
tion of at a glance the circumstances of the vibratory motion at
wavci. jjjQ instant of time for which it has been constructed, but
also for any subsequent moment. Thus, if we desire to
T
consider what is going on after an interval — , we have
simply to conceive the whole wave (whether of displace-
ment or velocity) to be moved to the right through a dis-
tance = a 6. Then the state of motion in which a was
before will have been transferred to b, that of b will have
been transferred to c, and bo on. At the end of another
such interval, the state of the particles will in like manner
be represented by the wave, if pushed onward through
another equal space. In short, the whole circumstances
Jiiiy be pictured to the eye by two waves (of displacement
and of velocity) advancing continuously in the line a he . ..
with a velocity V which t^tH take it over the distance ab in
the time --,V being therefore = ^ = ^^ -= -^ or V = ^ .
This is termed the velocity of propagation of the wave,
and, as we see, is equal to the length of the wave divided
by the time of a complete vibration of each particle.
If, as is usually more convenient, wo express T in terms
of the number » of complete vibrations performed in u
given time, say in the unit of time, we shall have tr =< n ,
and hence
V = /a.
1-t. There is one very important distinction between the V»riatit>n»
two cases of longitudinal and of transversal vibrations which °' <1«"'V
now claims our attention, viz., that whereas vibrations of •'iuji'nj''
the latter kind, when propagated from particle to particle vibr»tio«».
in an clastic medium, do not alter the relative distances of
the particles, or, in other words,, cause no change of density
throughout the medium; longitudinal vibrations, on the
other hand, by bringing the particles nearer to or further
from one another than they are when undisturbed, are
necessarily accompanied by alternate condensations and.
rarefactions.
Thus, in fig. 2, wo see that at the instant to which that
fig. refers, the displacements of the particles immediately
adjoining a are equal and in the same direction ; hence at
that moment the density of the medium at a is-equal to
that of the undisturbed medium. The same applies to the
points h, p, (tc, in which the displacements are at their
ma.xima and the velocities of ■s'ibration = 0.
At any point, such as c, bet^veen a and A, the displace-
ments of the two adjoining particles on either side are both
to the right, but that of the preceding particle is now the
greater of the two, and hence the density of the medium
throughout aX exceeds the undisturbed density. So at
any point, such as/, between A and A, the same result holds
good, because now«the displacements are to the left, but
are in excess on the right side of the point /. From a
to k, therefore, the medium is condensed.
From A to B, as at k, the displacements of the two
particles on either side are both to the left, that of the pre-
ceding particle being, however, the greater. The medium,
therefore, is here in a state of rarefaction. And in like ,
manner it may be shown that there is rarefaction from B
to ^;' so that the medium is rarefied from A to p.
At A the condensation is a maximum, because the dis-
placements on the two sides of that point are equal and
both directed towards A. At B, on the other hand, it is
the rarefaction which is a maximum, the displacements on
the right and left of that point being again equal, but
directed outwards from B.
It clearly follows from all this that, if we trace a curve
of which any ordinate shall be proportional to the differ-
ence betweeu the. density of the corresponding poir.* of the
disturbed medium and the density of the untb'dturbed
medium — ordinates drawn upwards indicating condensation,
and ordinates drawn downwards rarefaction — that curve
will cross the line of rest of the particles abc. . . in the
same points as does the curve of velocities, and will there-
•fore be of the same length X, and will abo rise above that
line and dip below it at the same parts. But th" connec-
tion between the wave of condensation and rarefaction and
the wave of velocity, is still more intimate, when the
extent to which the particles are displaced is very small, .j
is always the case in acoustics. For it may be shown t'nat
then the degree of condensation or rarefaction at any point
of the medium is proportional to the velocity of vibr atioi
at that point . The same ordinates, therefore, will repro
ACOUSTICS
IOC
^eut th'e clogreo3 of condensation, whicli represent the
I elocitiea, or, in other words, the waTe of condensation and
rarefaction may be regarded as coincident with the velocity
wave.
Past IL
Vdocily of proparjatian of waves of longitudiiiat, disturbance
thronr/h any elastic medium.
15. Sir Isaac Newton was tlie first who attempted to de-
termine, on theoretical grounds, the velocity of sound in
air and other fluids. The formula obtained by him gives,
however, a numerical value, as regards air, falling far short
of the result derived from actual experiment ; and it was
not till long afterwards, when Laplace took up the ques-
tion, that complete coincidence was arrived at between
theory and observation. We are indebted to the late Pro-
fessor Rankine, of Glasgow {Phil. Trans. 1870, p. 277)i,
for a very simple and elegant investigation of the question,
which we will here reproduce in an abridged form.
Let us conceive the longitudinal disturbance to be pro-
])agated through a medium contained in a straight tube
having a trensverse section equal to unity, but of indefinite
length.
Let two transverse planes A, A, (fig. 3) be conceived
as moving along the in- ,
terior of the tube in the
same direction, and with
the same velocity V as the
disturbance-wave itself.
fJzTji.
Fig. 3.
Let M; «. be the velocities of displacement of the particles
of the medium at A, A. respectively, at any given instant,
estimated in the same direction as V; and p^p^ the corre-
sponding densities of the medium.
The disturbances under consideration, being such as
preserve a permanent type throughout their propagation,
it follows that the quantity of matter between A, and A,
remains constant during the motion of these planes, or that
as much must pass into the intervening space through one
of them as issues from it through the other. Now at \^
the velocity of the particles relatively to A, itself is V - u^
inwards, and consequently there flows into the space A, Aj
through A, a mass (V - a,)p, in the unit of time.
Forming a similar expression as regards A^, putting m for
the invariable mass through which the disturbance is pro-
pagated in the unit of time, and considering that if p de-
note the density of the undisturbed medium, m is evidently
equal to Vp, we have —
V-«.)p, = (V-«>, = Vp = m. . (I.)
Now, PiPj being the pressures at A,, A, respectively,
and therefore p,-p^ the force generating the acceleration
«, — «|, in unit of time, on the mass m of the medium, by the
second law of motion,
p,-p, = m{u,-u,) . . . (2.)
Eliminating «„ u^ from these equations, and putting for
— , — , - the symbols s^, s^, a (which therefore denote the
volumes of the unit of mass of the disturbed medium at
A,, A„ and of the undisturbed medium), we get :
m^ = ^Z!l andV^..= ?i^ '
Now, if (as is generally tne case in sound) the changes
of pressure and volume occurring during the disturbance of
the medium are very small, we may assume that these
changes are proportional one to the other. Hence, denot-
ing the ratio which any increase of pressure bears to the
diminution of the unit of volume of the substance, and
or V =
which is termed the elasticity of the substance, by f, we
shall obtain for the velocity of a wave of longitudinal dis-
placements, supposed small, the equation:
yil "■',
16. In applying this formula to the determination of
the velocity of sound in any particular medium, it is
requisite, as was shown by Laplace, to take into account
the thermic efi'ects produced by the condensations and-
rarefactions which, as we have seen, take place in the sub-
stance. The heat generated during the sudden compres-
sion, not being conveyed away, raises the value of the
elasticity above that which otherwise ii -^jould have, and
which was assigned to it by Sir Isaac Newton,
Thus, in a perfect gas, it is demonstrable by the priii
ciples of Thermodynamics, that the elasticity e, which, in
the undisturbed state of the medium, would be simply
equal to the pressure p, is to be made equal to yp, where
y is a number exceeding unity and represents the ratio of
the specific heat of the gas under constant pressure to its
specific heat at constant volume.
Hence, as air and most other gases may be practically
regarded as perfect gases, we have for them :
V= ^s= f^ . . . (II.)
17. From this the following inference may be drawn: —
Xhe velocity of sound in a given gas is unafi'ected by
chaiige of pressure if unattended by change of temperature.
P .
For, by Boyle's law, the ratio - is constant at a given
temperature. The accuracy of this inference has been con-
firmed by recent experiments of Regnault.
18. To ascertain the influence of change of temperature
on the velocity of sound in a gas, we remark that, by Gay
Lussac's law, the pressure of a gas at different tempera-
tures varies proportionally both to its density p and to
I +at, where t is the number of degrees of temperature
above freezing point of water (32° Fahr.), and a is the expan-
sion of unit of volume of the gas for every degree above
32°.
If, therefore, p, p„, p, p„ denote the pressures and densities
corresponding to temperatures Z2° + t° and 32°, we have:
^ = -1 (1 + aO
Po Pa
and hence, denoting the corresponding velocities of sound
by V, V„ we get
^= 7(1 +"0
whence, o being always a very small fraction, is obtained
very nearly:
V
1
Laplace's
correction.
Velocity of
sOUQtl ill
.lir is inde-
pendent
of the
prebsure.
EfTect of
change of
tenipera-
:nre.
v„
-i--«andV-V,= 2.<.V,
The velocity increases, therefore, by - V„ for every de-
gree of rise of temperature above 32°.
19. The general expression for V given in (II.) may be
put in a difi'erent form : if we introduce a height H of the
gas, regarded as having the same density p throughout and
exerting the pressure p, then p=ffpTl, where g is the
acceleration of gravity, and there results :
V
Another
expressioiv
for V.
Now JiU. or ^2?.
7^
2
(in.'i
is the velocity U which would
bo acquired by a body falling in vacuo from a height —
Hence V = U Jy.
J 04
ACOUSTICS
JJnmcricul
fraluo of V
' »ir.
.1-110 ft.
<>
in ■lifTv.
it (jases
[Rx|»rl-
nienta for
'determiii-
(iiig V in
sir.
V ileppiicis
onintensity
of aouuil.
y depends
en the
pitch of
Bound.
If y were equal to 1, V ■= U, which is the result obtained
fcy Newton, nii'i would indicate that the velocity of sound
in a gas equals the velocity of a body falling from a height
equal to half of that of a homogeneous atniosphero of the
gas.
20. In common dry air at 32° Fahr., g being 32-2 ft., and
the mercurial barometer 30 ins. or 25 ft., the density of
air is to that of mercury as 1 : 10,485 '6 ; hence H =
10,458-6 x2-d ft. = 26,214 ft.
Also y= 1-408
Hence V,- ^1,408 x 32,2 x 26,214 = 1 090 ft.
and, by § 18, the increase of velocity for each degree of rise
/ , . IN. 1090 545
of temperature [a being — j 's — or -^
•crj' n(Jlfrly.
21. If the value of y were the same for different gases,
it is obvious from formula V= /y ? that, at a given
temperature, the velocities of sound in those gases would be to
each other inversely as the square roots of their den.sities.
Eegiiault has foiuid that this is so for common air, carbonic
acid, nitrous oxide, hydrogen and ammoniacal gas (though
less so as regards the two la.st).
22. The experimental determination of the velocity of
sound in air has been carried out by ascertaining accurately
the time intervening between the flash and report of a gnn
as oljserved at a given distance, and dividing the distance
by the time. A discussion of the many experiments con-
ducted on this principle in various countries and at various
periods, by Van Der Kolk (Land, and Edin. /'hi!. May.,
July 1865), assigns to the velocity of sound in dry air at
32° Fahr., 1091 ft. 8 in. per second, with a probable error
of ±3-7 ft; and .still more recently (in 1871) Mr Stone,
the Astronomer Royal at the Cape of Good Hope, has
found 1090-6 as the result of careful experiments by him-
self there. The coincidence of these numbers with that
we have already obtained theoretically suificiently estab-
lishes the general accuracy of the theory.
23. Still it cannot be overlooked that the formula for
V is founded on assumptions which, though approximately,
are not strictly correct. Thus, the air is not a perfect gas,
nor is the variation of elastic force, caused by the passage
through it of a wave of disturbance always very small in
comparison with the elastic force of the undisturbed air.
Eamshaw (1858) first drew attention to these points, and
came to the conclusion that the velocity of sound increases
with its loudness, that is, with the violence of the disturb-
ance. In confirmation of this statement, he appeals to a
singular fact, viz., that, during experiments made by
Captain Parry, in the North Polar Regions, for determin-
ing the velocity of sound, it was invariably found that the
report of the discharge of cannon was heard, at a distance
of 2J miles, perceptibly earlier than the sound of the word
fire, which, of course, preceded the discharge.
As, in the course of propagation in unlimited air, there
is a gradual decay in the intensity of sound, it would fol.
low that the velocity must also gradually decrease as the
sound proceeds onwards. This curious inference has been
verified experimentally by Regnault, who found the velocity
of sound to have decreased by 2 2 ft. per second in passing
from a distance of 4000 to one of 7500 feet.
24. Among other interesting results, derived by the
accurate methods adopted by Regnault, but which want of
space forbids us to describe, may be mentioned the de-
pendence of the velocity of sound on its pitch, lower notes
being, ccet. par., transmitted at a more rapid rate than higher
ones. Thus, the fundamental note of a trumpet travels
faster than ita harmonies.
25. The velocity of sound in liquids and BoKds (the di»- V inli(tni4«
placements being longitudinal), may be obtained by formula »"<* eolida
(I.), neglecting the thermic effects of the compresr.ions and
expansions as being comjjaratively inconsiderable, and may
be put in other forms:
Thus, if wp denote by • the change in length of one foot
of a column of the substance produced by its own weight
w, then e being = - or — , -we have - - - and hence:
• I - I
v^y?. . . . (IV.)
or, replacing - (which is the length in feet of a column
that would be increased 1 foot by the weight of 1 cubio
foot) by /,
V- ^/ir . . (V.)
which shows that the velocity la that due to a fall through
2 •
Or, again, in the case of a liquid, if ij denote the change
of volume, which would be i^roduced by an increase of
pressure equal to one atmosphere, or to that of a column
H of the liquid, since i is the change of volume due to
11 H 1
weight of a column 1 of the liquid, and .-. - = — end -
H
, we get
V =
,!?H
Ex. 1. For water.
(VL
2u,000 very nearly; H = 34 ft. V in water.
and hence V = 4680 feet.
This number coincides very closely with the value ob-
tained, whether by direct experiment, as by CoUadon and
Sturm on the Lake of Geneva in 1826, who found 4708,
or by indirect means which assign to the velocity in the
water of the Eiver Seine at 59° Fahr. a velocity of 4714 ft.
(Wertheim).
Ex. 2. For iron. Let the weight necessary to double V in iron.
the length of an iron bar be 4260 millions of lbs. on the
square foot. Then a length I will bo extended to / -1- 1 by
, 4260 millions lbs. , , rm • , ,
a force of on the sq. ft. ihis, therefore,
by our definition of I, must be the weight of a cubic foot
of the iron. Assuming the density of iron to be 7-8, and ,
62-32 lbs. as the weight of a cubic foot of water, we get
7-8 X 62-32 or 486 lbs. as the weight of an equal bulk of
iron. Hence
4260 millions
which gives V = ^gl
. 486 and I = —-r- miUions,
i ■.,,.
millions
-/
ir5? X 1000 = 1000 V284'
15
or V = 17,000 feet per second nearly.
As in the case of water and iron, so, in general, it may
be stated that sound travels faster in liquids than in air,
and stiU faster in solids, tlie ratio - being least in gases
f
and greatest in solids.
26. Biot, about 50 years ago, availed himself of the Eiperi-
great difference in the velocity of the propagation of sound Tnental de-
through metals and through air, to determine the ratio of termina-
the one velocity to the other. A bell placed near one ex- ''^■'' "' ^
tremity of a train of iron pipes forming a joint length of
upwards of 3000 feet, being struck at the same instant as
the same extremity of the pipe, a person placed at the
other extremity heard first Ae sound of the blow on the
pipe, conveyed through the iron, and then, after an interval
ACOUSTICS
105
of time, -which was noted as accurately as possible, the
sound of the bell transmitted through the air. The
result was a velocity for the iron of 10'5 times that in air.
Simil&r experiments on iron telegraph wire, made more
recently near Paris by Wertheim and Brequet, have led to
an almost identical number. Unfortunately, owing to
the metal in those experiments not forming a continuous
whole, and to other causes, the results obtained, which fall
short of those otherwise-found, cannot be accepted as correct.
Other means therefore, of an indirect character, to which
we will refer hereafter, have been resorted to for deter-
mining the velocity of sound in solids. Thus Wertheim,
from the pitch of the lowest notes produced by longitudinal
friction of wires or rods, has been led to assign to that
velocity values ranging, in different metals, from 16,822
feet for iron, to 4030 for lead, at temperature 68° Fahr.,
and which agree most remarkably with those calculated by
means of the formula V = / - . He points out. however,
tiat these values refer only to solids whose cross dimensions
are small in comparison with their length, and that in order
to obtain the velocity of sound in an unlimited solid mass,
it is requisite to multiply the value as above found by
J i OT ^ nearly. For while, in a solid bar, the extensions
and contractions due to any disturbance take place laterally
as well as longitudinally ; in an extended solid, they can
only occur in the latter direction, thus increasing the
vtiue of e.
27. To conyplete the discussion of tho velocity of the
propagation of sound, we have still to consider the case of
transversal vibrations, such as are executed by the points
of a stretched wire or cord when drawn out of its position
of rest bv a blow, or by the friction of a violin-bow.
Fig. i.
Velocity of Lgj q^ (gg 4) ^^ ^fjg position of the string when nndis-
tion of ' turbed, mnp when displaced. We wiU suppose the amount
ttensversal "^f displacement to be very small, so that we may regard
vibrations, the distance between any two given points of it as remain-
ing the same, and also that the tension P of tho string
is not changed in its amount, but only in its direction.
which is that of the string.
Take any origin in ox, and ab = hc = Ix (a very small
quantity), then the perpendiculars am, In, cp, are the dis-
placements of abc. Let k, I be the middle points of mn,
np; then U (which = ot7i or ah very nearly) may be re-
garded as a very small part of the string acted on by two
forces each = P, and acting at n in the directions np, nm.
These give a component parallel to ac, which on our sup-
position is negligible, and another F along nb, such that
F = P^8in9-sin(9'1 = P. ("ll-^^^V.
\mn nqj
nq-pr
nqJ Jx
Now if c = a length of string of weight equal to P, and
the string be suppo.-ed of uniform thickness and density,
P P
the weight of ld = - .U = -. Ix, and the mass to of W =
P.
Ix.
Hence the acceleration / in direction nb \
J-
If we denote ma by y, oa by x, and the time by t, via
ehaU readily see that this equa'ion becomes ultimately,
(Py cpy
■which is satisfied by putting
y = (a; -f Jge. t) + ili (x- Jgc. t)
where ^ and \p indicate any functions.
Now we know that if for a given value of t, x be in-
creased by the length A of the wave', the value of y remains
unchanged; hence,
4> {^+ Jff':- t) + iiC.^-*^(x + \+ Jfc. f) &c.
But this condition is equally satisfied for a given value of
... '^
X, by increasing J gc. t. by X, i.e., increasing t by ~y=^ .
This therefore must — T ''the time of a complete vibration
of any point of the string j. But V = =;. Hence,
V = V^ (VIL)
is the expression for the velocity or sound when due to
very small transversal vibrations of a thin wire or chord,
which velocity is consequently the same as would be
acquired by a body falling through a height equal to one
half of a length of the chord such as to have a weight
equal to the tension.
The above may also be put in the form —
9P
where P is the tension, and w the weight of the unit of
length of the chord.
28. It appears then that while sound is propagated by
longitudinal vibrations through a given substance with the
same velocity under all circumstances, the rate of its trans-
mission by transversal vibrations through the saiae sub-
stance depends on the tension and on the thickness. Tte
former velocity bears to the latter the ratio of J~l: J~c,
(where / is the length of the substance, which would be
lengthened one foot by the weight of one foot, if we take
the foot as our unit) or of /- : 1, that is, of the square
root of the length which would be extended one foot by
the weight of c feet, or by the tension, to 1. This, for
ordinary tensions, results in the velocity for longitudinal
vibrations being verv much in excess of that for transversal
vibrations.
29. It is a well known fact that, in all but very excep-
tional cases, the loudness of any sound is less as the dis-
tance increases between the source of sound and the ear.
The law according to which this decay takes place is the
same as obtains in other natural phenomena, viz., that in
an unlimited and uniform medium the loudness or intensity
of the sound proceeding from a very small sounding body
(strictly speaking, a point) varies inversely as the square
of the distance. This follows from considering that the
ear AC receives only the conical portion OAC of the whole
volume of sound emanating from O, and that in order that
an ear BD, placed at a
greater distance from O,
quantity, its area must be
to that of AC : as OB^ :
0A2. But if A' = AC
be situated at same dis- ^ig- 6-
tance as BD, the amount of sound received by it and by
BD (and therefore by AC) will be as th<> area of A' or
Compari-"
son of V
for trans- '
versal and
for loDgi- •
tudinal
vibrations.
Law ot >
decay of '
intensity 0^
sounds
with in-
creased dia^
tance.
AC to that of BD.
Hence, the intensities of the sound
L — 14
106
ACOUSTICS
heard by the same ear at the difitanucs OA and OB are to
each other as OB- to OA''.
Iiifluenceot 30. In order to verify the above law when the atmo-
iliminished Bptere forms the intervening medium, it would be necessary
density of jg fggj jj. ^j ^ considerable elevation above the earth's
inU!n8ity"of surface, the car and the source of sound being separated
sound. 'by air of constant density. As the density of the air
diminishes, we should then find that the loudness of the
sound at a given distance would decrease, as is the case in
the air-pump experiment previously described. Thia arises
from the decrease of the quantity of matter impinging on
the ear, and the consequent diminution of its vis-viva.
The decay of sound due to this cause is (fbServable in the
rarefied air of high mountainous regions. De Saussure, the
celebrated Alpine traveller, mentions that the report of a
pistol at a great elevation appeared no louder than would
a small cracker at a lower level.
But it is to be remarked that, according to Poisson,
when air-strata of different densities are interposed between
the source of sound and the ear placed at a given distance,
the intensity depends only on the density of the air at the
source itself; whence it follows that sounds proceeding
from the surface of the earth may be heard at equal dis-
tances as distinctly by a person in a floating balloon as by
one situated on the surface itself; whereas any noise origi-
nating in the balloon would be heard at the surface as
faintly as if the ear were placed in the rarefied air on a
level with the balloon. This was exemplified during a
balloon ascent by Glaiaher and Coxwell, who, when at an
elevation of 20,000 Itet, heard with great distinctness the
whistle of a locomotivo jissing beneath them.
Tart m.
Reflexion and Refraction of Sound.
31. When a wave of sound travelling through one
medium meets a second medium of a different kind, the
vibrations of its own particles are communicated to the
particles of the new medium, so that a wave is excited in
the latter, and is propagated through it with a velocity de-
pendent on the density and elasticity of the second medium,
and therefore differing in general from the previous velocity.
The direction, too, in which the new wave travels is dif-
ferent from the previous one. This change of direction is
termed refraction, and takes place according to the same
laws as does the refraction of light, viz., (1.) The new
direction or refracted ray lies always in the plane of
incidence, or plane which contains the incident ray (i.e.,
the direction of the wave in the first medium), and the
normal to the suriace separating the two media, at the
point in which the incident ray meets it; (2.) The sine of
the angle between the normal and the incident ray bears to
the sine of the angle between the normal and the refracted
ray, a ratio which is constant for the same pair of media.
For a theoretical demonstration of these laws, we must
refer to the art. Optics, where it will be shown that the
ratio involved in the second law is always equal to the
ratio of the velocity of the wave in the first medium to the
velocity in the second ; in other words, the sines of the
angles in question are directly proportional to the velocities.
32. Hence sonorous rays, in passing from one medium
into another, are bent in towards the
normal, or the reverse, according as the
velocity of propagation in the former
exceeds or falls short of that in the latter.
Thus, for instance, sound is refracted
towards the perpendicular when passing
into air from water, or into carbonic acid
gas from air; the converse is the case when
the passage takes place the opposite way.
Laws ot
refraction.
Refraction
is to or
Irom the
norraal ac-
cording to
relative
values of
tlie velo-
cities.
Limiting
angle and
toUl ra
fiejdon.
Fig. 6.
33. It further follows, as in the analogous case of light,
that there is a certain angle termed the limiting anffle,
whose time is found by dividing the less by the greater
velocity, such that all rays of sound meeting the surface
separating two different bodies will not pass onwar<l,
but suffer total reflexion back into the first Ixxly, if
the velocity in that body is less than that in the other
body, and if the angle of incidence exceeds the limiting
angle.
The velocities in air and water oeing respectively 1090
and 4700 feet, the limiting angle for these media may bo
easily shown to be slightly above 15J°. Hence, rays of
sound proceeding from a distant source, and therefore
nearly parallel to each other, and to PO (fig. 6), the angle
POM being greater than 15 J", will not pass into the water
at all, but suffer total reflexion. Under such circumstances,
the report of a gun, however powerftil, would be inaudible
by an ear placed in the water.
34. As light is concentrated into a focus by a convex Aconstio
glass lens (for which the velocity of light is less than for •'-'"'"■
the air), so sound ought to be made to converge by passing
through a convex lens formed of carbonic acid gas. On
the other hand, to produce convergence with water or
hydrogen gas, in both which the velocity of sound exceeds
its rate in air, the lens ought to be coTieave, These results
have been confirmed expcriiiientally by Sondhaus and
Hajech, who also succeeded in verifj-ing the law of the
equality of the index of refraction to the ratio of the
velocities of sound.
35. When a wave of sound falls on a surface separating Laws of
two media, in addition to the refracted wave transmitted 'flesion-
into the new medium, which we have ju.st been consider-
ing, there is also a fresh wave formed in the new medium,
and travelling in it in a different direction, but, of course,
with the same velocity. This reflected wave is subject to
the same laws as regulate the reflexion of light, viz., (1.)
the coincidence of the planes of incidence and of reflexion,
and (2.) the equality of the angles of incidence and
reflexion, that is, of the angles made by the incident and
reflected rays with the normal.
36. As in an ellipse (fig. 7), the normal PG at any point Refleiun
bisects the angle SPH (S, H by - sphe-
being the foci), rays of sound — '""'-
diverging from S, and falling on
the spheroidal surface formed by
the revolution of tlie ellipse about
the longest diameter AB, will be
reflected to H. Also, since SP
+ PH is always = AB, the times in which the different rays
will reach H will all be equal to each other, and hence a
crash at S wiU be heard as a crash at H.
37. At any point P of a parabola (fig. 8) of which S is Kelleiioii
the focus, and AX the axis, the normal. PQ bisects the ^.P^
angle SPX, PX being
drawn parallel to AX.
Hence rays of sound
diverging from S, and
falling on the paraboloid
formed by the revolution
axis, wiU all be reflected
in directions parallel to
the axis. And vice versa
rays of sound XP, XQ,
bolic np
faces.
Fig. 8.
A-c, from a very distant source, and parallel to the axis of
a paraboloid, will be reflected into the focus. Con
sequently, if two reflecting paraboloids be placed at a
considerable distance from and opposite to each other,
with their axis coincident in direction (fig. 9), the tick of
a watch placed at the focus S of one will be heard di»
tinctly by an ear at S'. the focus of the other.
ACOUSTICS
107
Echoes.
Fig. 9.
38. As a Imninous object may give a succession of
images ■when placed between two or more reflecting sur-
faces, so also in like circum-
jStances may a aound suffer
[repetition.
To these principles are
easily traceable all the pecu-
liarities of echoes. A wall
or steep cliff may thus send
back, somewhat reduced in
intensity, a shout, the report
of a pistol, ifcc. The time
which elapses between the sound and its echo may be
easily deduced from the known velocity of sound in air,
if the distance of the wall be given. Thus, for a distance
of 37 yards, the interval will be found by dividing the
ilouble of that or 74 yards by 370 yards, the velocity of
Eound at 50° Fahr., to amount to ^ of a second. Hence, if
we assume that the rate at which syllables can be distinctly
uttered is five per second, the wall must be at a distance
iD-xceeding 37 yards to allow of the echo of a word of one
syllable reaching the ear after the word has been uttered,
74 yards for a word of two syllables, and so on.
If the reflecting surface consists of one or more walls,
cliffs, itc, forming together a near approach in shape to
that of a prolate spheroid or of a double parabolic surface,
then two points may be found, at one of which if a source
cf sound be placed, there will be produced, by conver-
gence, a distinct echo at the other. As examples of this
may be mentioned the whispering gallery in St Paul's,
I..ondon, and the stOl more remarkable case of the
Cathedral of Girgenti i;? Sicily mentioned by Sir John.
Herschel.
Sonnrl con. 39. On similar principles of repeated reflexion may be
»ej-ed over explained tie well-known fact that sounds may be con-
water, &.C. veyed to great distances with remarkably slight loss of
intensity, on a level piece of ground or smooth sheet of
water or ice, and still more so in pipes, chimneys, tunnels,
itc Thus, in one of Captain Parry's Polar expedi-
tions, a conversation was on one occasion carried on,
at a distance of IJ nule, between two individuals sepa-
rated by a frozen sheet of water. M. Biot heard distinctly
from jne end of the train of pipes f cf a mile long,
previously referred to, a low whisper proceeding from
the opposite end.
Practical illustrations are afforded by the system of
communication by means of tubing now so extensively
adopted in public and private buildings, and by the speak-
ing trumpet and the far trumpet
40. The prolonged roll of thunder, with its manifold
varieties, is partly to be ascribed to reflexion by moun-
tains, clouds, (tc. ; but is mainly accounted for on a diffe-
rent acoustic principle, viz., the comparatively low rate of
transmission of sound through air, as was first shown
by Dr Hooke at the close of the 17th century. The ex-
planation will be more easily understood by adverting
to the case of a voUey fired by a long line of troops. A
person situated at a point in that line produced, will first
it is evident hear the report of the nearest musket, fol-
lowed by that of the one follo-vring, and so down to the
last one in the line, which will close the prolonged roU
thus reaching his ear j and as each single report will appear
to him less intense according as it proceeds from a greater
distance, the roll of musketry thus heard will be ore of
gradaally decreasing loudr.ess. But if he were to place
himself at a relatively great distance right opposite to
the centre of the line, the separate reports from each of
the two wings would reach him nearly at the same moment,
and .hence the sound of the volley would now approach
more nearly to that of a single loud crash. If the line of
Thimiler.
Boldiers formea an arc of a circle having Its centre in his
position, then the distances gone over by the separate
reports being equal, they would reach his ear at the same
absolute instant of time, and with exactly equal intensi-
ties; and the effect produced would be strictly the same
as that of a single explosion, equal in violence to the sum
of all the separate discharges, occurring at the same dis-
tance. It is easy to see that, by varying the form of the
line of troops and the position of the observer, the sonorous
effect win be diversified to any extent desired. If then
we keep in view the great diversity of form exhibited by
bghtning-flashes, which may be regarded as being Hies, at
the points of which are generated explosioms at the same
instant of time, and the variety of distance and relative
position at which the observer may be placed, we shall
feel no difficulty in accounting for all those acoustic pheno-
mena of thunder to which Hooke's theory is applicable.
Pam IV.
The Principles of Musical SarTnpny.
41. A few words on the subject of musical Tiurmon^
must be introduced here for the immediate purposes of
article on that subject.
Sounds in general exhibit three different qualified, so
far as their ett'ect on the ear is concerned, viz., loudness,
pitch, and timbre.
Loudness depends, ccet. par., on the violence with which
the vibrating portions of the ear are excited; and there-
fore on the extent or amplitude of the Wbrations of the
body whence the sound proceeds. Hence, after a bell has
been struck, its effect on the ear gradually diminishes as
its vibration becomes less and less extensive. By the
theory of vibrations, loudness or intensity is measured by
the vis-viva of the vibrating particles, and is consequently
proportional to the square of their maximum velocity or
to the square of their maximum displacement. Helm-
holtz, however, in his remarkable work on the perception
of tone, observes that notes differing in pitch differ also in
loudness, where their vis viva is the same, the higher note
always exhibiting the greater intensity.
42. Difference of pitch is that which finds expression in
the common terms applied to notes : Acute, shrill, high,
sharp, grave, deep, low, fiat. We will point out presently in
what manner it is established that this quality of sound de-
pends on the rapidity of vibration of the particles of air in
contact with the external parts of the ear. The pitch of
a note is higher in proportion to the number x>l vibrations
of the air corresponding to it, in a given time, such as one
V
second. If n denote this number, then, by § 13, n =—,
and hence, V being constant, the pitch is higher the less
the length X of the wave.
43. Timbre, or, as it is termed by German authors,
Maruf-farbe, rendered by TyndaU into clang-colour or clang-
lint,\>VL\. forwhich we wouldsubstitute the expression acojisiw;
colour, denotes that peculiarity of impression produced on
the ear by sounds otherwise, in pitch, loudness, ic, alike,
whereby they are recognisable as different from each other.
Thus human voices are readily interdistioguishable ; so
are notes of the same pitch and intensity, produced by
different instruments. The question whence arises this dis-
tinction must be deferred for the present.
44. Besides the three qualities above mentioned, there
exists another point in which sounds may be distinguished
among each other, and which, though perhaps reducible to
difference of timbre, requires some special remarks, viz.,
that by which sounds are characterised, either as noises or
as muMcal notes. A musical note is the result of reeular.
Loudness
depends on
e-vteut of
vibration.'
Pitch de-
pends cir
rapidity of
vibration.
Timbre.
DistincttoD
between
noises and
musical
notes.
108
ACOUSTICS
Laws of
musical
Iiarmony.
Patios of
vibrutions.
Unison.
Octave.
Tivel!'tl>
aijj Fillli
periodic vibrations of the air-particles acting on the car,
and therefore also of the body whence they proceed, each
]inrticIo pa.ising through the same phase at stated intervals
ijf time. On the other hand, the motion to which noise is
due is irregular and flitting, alternately fast and slow,
and creating in the mind a bewildering and confusing
effect of a more or less unpleasant character. Noise may
also bo produced by combining in an arbitrary manner
several musical notes, as when one leans with the forearm
against the keys of a piano. In fact, the composition of
regular periodic motions, thus effected, is equivalent to an
irregular motion.
'45. We now proceed to state the laws of musical har-
mony, and to desonbe certain instrnments by means of
which they admit of being experimentally established.
The chief of these laws are as follow : —
(1.) The notes employed in music alwiiya TOrrespond
to certain deGnite and invariable ratios between the num-
bers of vibrations performed in a given time by the air
\vhen conveying these notes to the ear, and these ratios
are of a very simple kind, being restricted to the various
permutations of tho first four prime numbers 1, 2, 3, 5,
and their powers.
(2.) Two notes are in unison whose corresponding vibra-
tioift are executed exactly at the same rate, or for which
{denoting by n, n, the numbers per second) -» — 1. This
ratio or interval (as it is termed) is the simplest possible.
2, and is
termed the octave.
(4.) The interval -1 — 3 is termed the twelfth, and if
we reduce the higher note of the pair by an 8", i.e., divide
its number of vibrations by 2, we obtain the interval
-^ = -, designated as the interval of the f/th.
Major
third.
Major
sixth.
Minor
third.
Foolth.
Second.
jeventb.
Diatonic*
cale.
(3.) The next interval is that in which — ■
n
(5.) The interval
5 has no particular name at-
tached to it, but if we lower the higher note by two
8™ or divide n, by 4, we get the interval --^ - -, or the
interval of the mqjor third.
(6.) The interval -^ - - is termed the myor sixth,
n 3
The interval -^ - — — =- - is termed the minor
n 5
(7.
third.
(S.) The interval ^
2x2
3
- is termed the fourth
another fifth, which
9 . 3 3
(9.) The interval - which, being — r x -, may be r&-
~2~
garded as formed by taking in the first place a note one-
fifth higher than the key-note or fundajuental, i.e., higher
3
than the latter by the interval -, thence ascending by
3 3
gives us - X - and lowering this by
g
an octave, which results in - , which is called the second
8
(10.) The interval -r or t x - may be regarded as the
o 2 4
major tliird' (- j of the fifth (- j,and is called the interval
of the seventh.
46. If the key-note or fundamental be denoted by C,
and the notes, whose intervals above C are those just
enumerated, by D, E, F, G, A, B, C, we form what is
known in music aa tho natural or diatonic: scale, in which
therefore the intervals reckoned from C are successively
9 S 4 3 8 IS
8' 4' 3' 2' 3' 8' "
and therefore, tho intervals between each Lote and the
ono following are
9
10
16
9
10
9
18
8'
8"
16'
8"
9'
8'.
i's
Of these last intervals the first, fourth, and eirtA are
g
each — -, which is termed a mcy'or tone. The second and
8'
ilojortone.
ilLDOr t0t;*j
10
jifih are each - — , which is a ratio slightly less than
tho former, and hence is called a miner tone. The third
and seventh ore each — — , to which is given the name uf
semi-tone.
By interjxising an additional note between each pair of
notes whoso intcr\'al is a major or a minor tone, the result-
ing series of notes may bo made to exhibit a nearer ap-
proach to equality in the intervals successively separating
them, which will be very nearly semi-tonet. This sequence
of twelve notes forms the cl.tomcUic scale. Tho note inter-
posed between C and D is either C sharp (Cf) or D flat
(Db), according as it is formed by raisivj C a eeniitone or
lowering D by the same amount.
47. Various kinds of apparatus have been contrived with
a view of confirciing expenmentaUy tho truth of the laws
of musical harmony as above stated.
Savart's toothed wheel apparatus consists of a brass
wheel, whose edge is divided into a number of equal pro-
jecting teeth distributed uniformly over the circumference,
and which is capable of rapid rotation about an axis per-
pendicular to its plane and passing through its centre, by
means of a series of multiplying wheels, the last of which
is turned round by the hand. Tho toothed wheel being
set in motion, the edge of a card or of a funnel-shaped
piece of common note paper is held against the teeth,
when a note will bo heard arising from the rapidly suo-
ceeding displacements of the air in its vicinity. The pitch
of this note will, agreeably to the theory, rise as the rat»
of rotation increases, and becomes steady when that rota-
tion is maintained uniform. It may thus be brought into
unison with any sound of which it may be required to
determine the corresponding number of vibrations per
second, as for instance the note Aj, three 8"* higher than
the A which is indicated musically by a small circle placed
between the second and third lines of the G clef, which
A is the note of the tuning-fork usually employed for
regtJating concert-pitch. A; may be given by a piano.
Now, suppose that the note produced with Savart's appa-
ratus is in unison with Aj, when the experimenter turns
round the first wheel at the rate of 60 turns per minute or
one per second, and that the circumferences of the various
multiplying wheels are such that the rate of revolution of
the toothed wheel is thereby increased 44 times, then the
latter wheel will perform 44 revolutions in a second, and
hence, if the number of its teeth be 80, the number of
taps imparted to the card every second will amount to
44 X 80 or 3520. This, therefore, is the number of vibra-
tions corresponding to the note A3. If we divido this by
2^ or 8, we obtain 440 as the number of vibrations answer-
ing to the note A. This, however, tacitly assumes that
the bands by which motion is transmitted from wheel to
wheel do not slip during the experiment. If, as is always
more or less the case, slipping occurs, a different mode for
determining the rate at which the toothed wheel revolves,
such as is employed ia the syren of De la Tour {vide below),
Scmlton*.
OiroraaW"
»ca]e.
Sarart'i
toothed
'Jrheel ftp.
parator
COUSTICS
109
If, for the single toothed wheel, be substituted a set
of four with a common axis, in which the teeth are in
the ratios 4:5:6:8, and if the card be rapidly passed
along their edges, we shall hear distinctly produced the
fundamental chord C, E,G, C\ and shall thus satisfy our-
selves that the intervals C, E : C, G, and C C, are (as they
5 3
ought to be) -, -, and 2 respectively.
48. The st/ren of Seebeck is the simplest form of appa-
ratus thus designated, and consists of a large circular disc
of pasteboard mounted on a central axis, about which it
may be made to revolve with moderate rapidity. This disc
13 perforated with smaU round holes arranged in circles
tibout the centre of the disc. , In the first series of circles,
rsckoning from the centre, the openings are so made as to
divide the respective circumferences, on which they are
found, in aliquot parts bearing to each other the ratios of
the numbers 2, 4, 5, 6, 8, 10, 12, 16, 20, 24, 32, 40, 48,
64. The second series consists of circles each of which is
formed of two sets of perforations, in the first circle arranged
as 4 : 5, in the next as 3 : 4, then as 2 : 3, 3 : 5, 4 : 7.
In the outer series is a circle divided by perforations into
four sets, the numbers of aliquot parts being as 3 : 4 : 5 : 6,
followed by others which we need not further refer to.
The disc being started, then by means of a tube held at
cue end between the lips, and applied near to the disc at
the other, or more easily with a common bellows, a blast
of air is made to fall on the part of the disc which con-
tains any one of the above circles. The current being
alternately transmitted and shut off, as a hole passes on
and off the aperture of the tube or bellows, causes a vibra-
tory motion of the air, whose rapidity depends on the
number of times per second that a perforation passes the
mouth of the tube. Hence the note produced with any
given circle of holes rises in pitch as the disc revolves
more rapidly; and if, the revolution of the disc being kept
as steady as possible, the tube be passed rapidly across the
circles of the first series, the notes heard are found to pro-
duce on the ear, as required by theory, the exact impres-
sion corresponding to the ratios 2:4: &c., i.e., of a series
of notes, which, if the lowest be denoted by C, form the
sequence C C, Ej G, C, &c., &;. In Hke manner, the first
circle in which we have two sets of holes dividing the circum-
ference, the one into say 8 parts, and the other into 10, or
in ratio 4 : 5, the note produced is a compound one, such
as would be obtained by striking on the piano two notes
separated bv th« iutecyal of a major third ( - ]. Similar
results, aU agreeing with the theory, are obtainable by
means of the remaining perforations.
A still simpler form of syren may be constituted with a
good spinning top, a perforated card disc, and a tube for
blowing with.
49. The syren of Cagnard de la Tour is founded on the
same principle as the preceding. It consists of a cylindrical
chest of brass, the base of which is pierced at its centre
with an opening in which is fixed a brass tube projecting
outwards, and intended for supplying the cavity of the
cylinder with compressed air or other gas, or even liquid.
The top of the cylinder is formed of a plate perforated near
its edge by ioles distributed uniformly in a circle concen-
tric with the plate, and which are cut obliquely through
the thickness of the plate. Immediately above this fixed
plate, and almost in contact with it, is
another of the same dimensions, and
furnished with the same number, n, of
openings similarly placed, but passing
obliquely through in an opposite direction
frum those in the fixed plate, the one set
being inclined to the loft, the other to the right.
\'
Fie. 10.
This second plate is capable of rotation about a steel
axis perpendicular to its plane and passing through its
centre. Now, let the movable plate be at any time in a
position such that its holes are immediately above those in
the fixed plate, and let the bellows by which air is forced
into the cylinder (air, for simplicity. Being supposed to be
the fiuid employed) be put in action ; then the air in ita
passage will strike the side of each opening in the mov-
able plate in an oblique direction (as shown in fig. 10), and
Wl therefore urge the latter to rotation round its centra.
After -th of a revolution, the two sets of perforations wiH
again coincide, the lateral impuliTe of the air repeated, and
hence the rapidity of rotation increased. This will go on
continually as long as air is suppUed to the cylinder, and
the velocity of rotation of the upper plate will be accelerated
u^ to a certain maximum, at which it may be maintained
by keeping the force of the current constant.
Now, it is evident that each coincidence of the perforar
tions in the two plates is followed by a non-coincidence,
during which the air-current is shut off, and that con-
sequently, during each revolution of the upper plate, there
occur n alternate passages and interceptions of the current.
Hence arises the same number of successive impulses of
the external air immediately in contact with the movable
plate, which is thus thrown into a state of vibration at the
rate of n for every revolution of the plate. The result is
a note whose pitch rises as the velocity of rotation increases,
and becomes steady when that velocity reaches its constant
value. If, then, we can determine the number m of revolu-
tions performed by the plate in every second, we shall at
once have the number of vibrations per second correspond-
ing to the audible note by multiplj-ing m by re.
For this purpose the steel axis is furnished at its upper
part with a screw working into a toothed wheel, and driv-
ing it round, during each revolution of the plate, through
a. space equal to the interval between two teeth. An
index resembling the hand of a watch partakes of this
motion, and points successively to the divisions of a
graduated dial. On the completion of each revolution of
this toothed wheel (which, if the number of its teeth be
100, will comprise 100 revolutions of the movable plate),'
a projecting pin fixed to it catches a tooth of another
toothed wheel and turns it round, and with it a correspond-
ing index which thus records the number of turns of the
first toothed wheel. As an example of the application of
this syren, suppose that the number of revolutions of the
plate, as shown by the indices, amounts to 5400 in a
minute of time, that is, to 90 per second, then the number
of vibrations per second of the note heard amounts to
90n, or (if number of holes in each plate = 8) to 720.
50. Dove, of Berlin, has produced a modification of the ^°''^ '
syren by which the relations of different musical notes "^"^^^
may be more readily ascertained. In it the fixed and
movable plates are each furnished with four concentric
series of perforations, dividing the circumferences into
different aliquot parts, asp. ex., 8, 10, 12, 16. Beneath-
the lower or fixed plate are four metallic rings furni.shed
with holes corresponding to those in the plates, and which
may be pushed round by projecting pins, so as to admit
the air-current through any one or more of the series of
perforations in the fixed plate. Thus, may be obtained,
either separately or in various combinations, the four notes
whose vibrations are in the ratios of the above numbers,
and which therefore form the fundamental chord (GEO Cj).
The invenior has given to this instrument the name of the
many-voiced syren.
61. Heknholtz has further adapted the syren for more |,j,jj^j
extensive use, by the addition to Dove's instrument ofdoui,!^
another chest containiuB its own fixed and movable per-svrea..
ilO
ACOUSTICS
ViHo-,
graphs
The Plion
fiato<
forated plates and perforated rings, both the moveable plates
being driven by the same current and revolving about a com-
mon axis. Annexed is a figure of this instrument (fig. 1 1).
02. The relation between the pitch of a note and the
frequency of the correspond-
ing Wbrations has also been
studied by yraphic methods.
Thus, if an ela.stic metal slip
or a pig's bristle be attached
to one prong of a tuning-
fork, and if the fork, while
in Wbration, is moved rapidly
over a glass plate coated with
lamp black, the attiched slip
touching the plate lightly, a
vavy lino wUl be traced on
vibrations to and fro of the
;ork. The same result will
be obtained with a stationary
fork and a movable glass
plate; and, if the time oc-
cupied by the plate in moving
through a given distance can " •
be ascertained, and the number of complete undulations ex-
hibited on the plate for that distance, which is evidently
the number of vibrations of the fork in that time, is
reckoned, we sliaU have determined the numerical vibra-
tion-value of the note yielded by the fork. Or, if the same
plate be moved in contact with two tuning-forks, we shall,
by comparing the number of sinuosities in the one trace
with that in the other, be enabled to assign the ratio of
the corresponding numbers of vibrations per second. Thu.',
if the one note be an octave higher than the other, it will
give double the number of waves in the same distance. The
motion of the plate may be simply produced by dropping
it between two vertical grooves, the tuning-forks being
properly fixed to a frame above.
53. Greater accuracy may be attained with the so-called
Yibrograph or I'honautogrciph (Duhamel's or Ktenig's),
consisting of a glass cylinder coated with lamp-black, or,
better still, a mutallio cylinder round which a blackened
sheet of paper is wrapped. The cylinder is mounted on a
Vorizontal axis and turned round, while the pointer attached
to the vibrating body is in light contact with it, and traces
therefore a wavy circle, which, on taking off the paper and
flattening it, becomes a wavy straight line. The superiority
of this arrangement arises from the comparative facility
with which the number of revolutions of the cylinder in a
given time may be ascertained. In Koenig's phonauto-
graph, the axis of the cylinder is fashioned as a screw,
which works in fixed nuts at *he ends, causing a sliding as
well as a rotatory motion of the cyKnder. The lines traced
ont by the vibrating pointer are thus prevented from over-
lapping when more than one turn is given to the cylinder.
Any sound whatever may be made to record its trace on
the paper by means of a large parabolic cavity resembling
a speaking-trumpet, which is freely open at the wider ex-
tremity, but is closed at the other end by a thin stretched
membrane. To the centre of this membrane is attached a
small feather-fibre, which, when the reflector is suitably
placed, touches lightly thfi surface of the revolving cylinder.
Any sound (such as that of the human voice) transmitting
its rays into the reflector, and communicating vibratory
motion to the membrane, will cau.«e the feather to trace a
sinuous Une on the paper. If, at the same time, a tuning-
fork of known number of vibrations per second be made to
trace its own line close to the other, a comparison of the
two Unes gives the number corresponding to the sound
nnder consideration.
Paet V.
Stationary Wavet.
54. We hcve hitherto, in treating of the propagation of Stationtry
waves of sound, assumed that the. medium through which «avM pro-
it took place was unlimited in all directions, and th^t the ''"'^'" "^
source of sound was single. In order, however, to under- Msiu pro-
stand the principles of the production of sound by musical gieseivo
instruments, we must now direct our attention to the case wave*,
of two waves from different sources travelling through the
same medium in opposite directions. Any particle of the
medium being then affected by two different vibrations at
the same instant will necessarily exhibit a different state
of motion from that due to either wave acting sepai'ately
from the other, and we have to inquire what is the result of
this mutual interference (as it is termed) of the two given
waves. Supposing, as sufficient for our purpose, that the
given waves are of equal lengths and of equal amplitudes,
in other words, tha*. the corresponding notes are of the
same pitch and equally loud; and supposing, further, that
they are ad\'ancing in exactly opposite directions, we shall
now show that the result of the mutual interference of two
such waves is the production of a stationary wave, that
is, taking any line of particles of the medium along
the direction of motion of
the component waves, cer- i S > •; '
tain of them, such as a, c,
e ... at intervals each F'J- ^-■
= -, will remain constantly in their usual undisturbed posi-
tions. All the particles situated between a and c will
Wbrate (transversely or longitudinally, as the case may
be) to and fro in the same direction as they would if
affected by only one of the interfering waves, but with
different amplitudes of vibration, ranging from zero at a to
a ma.ximum <vt b and thence to zero at c. Those between c
and e will vibrato in like manner, but always in an opposite
direction to the similarly placed jiaiticles in ac, and so on
alternately.
The annexed figures will represent to the eye the states of
motion at intervals of time =- ^ of the time T of a complete
vibration of the particles. In fig. 13, 1, the particles in
ac are at their greatest distances from their undisturbed
positions (above or to the right, according as the motion is
transversal or longitudinal) In fig. 13, 2, they are all in
their undisturbed positions. In fig. 1 3, 3, the dis; lace
ments are all reversed relatively to fig. 13, 1. In fig. 13,
4, the particles are again passing through their equilibrium
positions, resuming the positions indicated Ln fig. 13. 1,
after the time T.
The points ace, &c., which remain stationary are termed Nwlwawl
nodes, and the vibrating Mrts between them ventral n:nlril
segments. «:gmcnt8..
54a. Proof. In fig. 14, 1, the fiill curved line represents Pioot
the two interfering waves at an instant of time such that
ACOUSTICS
111
in their progress towards eacn other, they are then coinci-
dent. It is obvious that the particles of the medium will
at the moment in question' be displaced to double the ex-
tent of the displacement producible by either wave alone,
80 that the resultant wave may be represented by the dotted
curve. In fig. 14, 2, the two interfering waves, repre-
sented by the full and dotted curves respectively, have each
Fir. H.
passed over a distance = \\, the one to the right, the other
to the left, and it is manifest that any disturbance of the
medium, producible by the one wave, is completely neutra-
lised by the equal and opposite action of the other. Hence,
the particles of the medium are now in their undisturbed
positions, .^n fig. 14, 3, a furth'er advance of the two
waves, each in its own direction, over a space = \\ has
again brought them into coincidence, and the result is the
wave represented by the dotted line, which, it will be re-
marked, has its crests, where, in fig. 1, are found troughs.
In fig. 14, 4, after a further advance = J A, we have a repeti-
tion of the case of fig. 14, 2, the particles are now again un-
affected by the waves. A stiU further advance of \ \, or
of \ reckoned from the commencement, brings us back to
the same state of things as subsisted in fig. 14, 1. An^in-
spection and inter-comparison of the dotted lines in these
figures are now sufficient to establish the accuracy of tb"
laws, before mentioned, of stationary waves.
Part VL
Musical Strings.
65. Wo have in musical string.? an instance of tlv
occurrence of stationary waves.
Let AB (fig. 15) be a wire or
Btring, supposed meanwhile to
be fixed only at one extremity B,
and let the wire be, at any part,
excited (whether by passing a
violin bow across or by friction
along it), so that a wave (whether of tranaversml or longi-
tudinal vibrations) is propagated thence towards B. On
reaching this point, which is fixed, refit tion will occur,
in consequence of which the particles there will sufTer a
complete reversal of velocity, just as when a perfectly
elastic ball strikes aj;ainst a smooth surface perpendi-
cularly, it rebounds with a velocity equal and opposite to
Oat it previously had. TTence, the displacement duo to
Fig. 16.
the incident wave being BlI, the displacement after re-
flcxiou wiU be BN equal and opposite to BM. and a
reflected wave will result) represented by the faint lino
in the fig., which will travels with the same velocity, but
in the opposite direction to the incident wave fully lined in
the fig. The interference of these two oppositely pro-
gressing waves will consequently give rise to a stationary
wave (fig. IG), and if we
take on the wire distances ""^ £ jj"
BC, CD, DE, &c. = i X, Fig-1«-
the points B, C, D, E, . . . wiU be nodes, each of which
separate portions of the wire vibrating in opposite direc-
tions, i.e., ventral segments.
5G. Now, it is obvious that, inasmuch as a node is a poini
which remains always at rest while other parts of tho
medium to which it belongs are vibrating, such point may
be absolutely fixed without thereby interfering with tho
oscillatory motion of the medium. If, therefore, a length
AB of wire be taken equal to any multiple oi-, A may bo
fixed as well as B, the motion remaining the same as
before, and thus we shall have the usual case of a musical
string. The two extremities being now both fixed, there
wiU be repeated reflexions at both, and a consequent
persistence of two progressive waves advancing in opposite
directions and producing together the stationary wave
above figured.
57. We learn from this that a musical string is suscep- Funda- .
tible of an infinite variety of modes of vibration corro-™^^^^_
vionding to different numbers of subdivision into ventral
segments.
"Thus, it may have'but one ventral segment (fig. 17), or
but two nodes formed by its
fixed extremities. In this carse, — -""^ "
the note emitted by it is the ^
lowest which can possibly be Fig. 17.
obtained from it, or, as it is called, its fundamental note.
If / denote the length of the wire, by what has been already
proved, i- -, and therefore the length of the wave \ =
21. " Hence, V being the velocity of propagation of the ware
through the wire, the number », of vibrations performed
in the unit of time with the fundamental note is — .
The next possible sub-division of tho wire is into tu-c
ventral segments, the three
nodes being the two fixed ^^ ~~^^c
ends A, B, and the middle ■*
point C (fig. 18). Hence, ? = A, Fig. 18.
and the number of vibrations n.
= — or double of those of the fundamental
The note,
therefore, now is an 8" higher.
Reasoning in a like manner for the cases of three, four,
&c., ventral segments, we obtain the foUowing general
law, which is applicable alike to tranMcrsely and to longi-
tudinally vibrating ■svires :
A wire or string fixed at both ends is capable of yielding, ir.
addition to its fundammtal note, any one of a scries of notet
corresponding to 2, 3, 4 times, etc., the number of vibrationi
per second of the fundamental, viz., he octave, twelfth, doublt
octave, &c.
These higher notes are termed the harmonics or (by the
Germans) the overtones of the string.
It is to be remarked that the overtones are in general
fainter the higher they are in the series, because, as the
number of ventral segments or independently ■i-ibrating
parts of the string increases, the extent or amplitude of j,[^y i,g
tho vibrations diminishes. liesrd to-
68. Not only may tho fundamental and its narmouio gether.
112
ACOUSTICS
Hannonics,
bow best
obtaiued.
Compari-
son of fun-
damentals
of strings
vibrating
transverse-
ly and Ion-
TransverRe-
ly vibrat-
ing string
1
nx -J
bo obtained independently of each other, but they are also
to bo heard Bimultaneously, particularly, for the reason
just given, those that are lower in the scale. A practised
ear easily discerns the coexistence of these various tones
when a pianoforte or violin string is thrown into Tibration.
It is evident that, in such case, the string, while vibrating
as a whole betweeh its fixed
extremities, is at the same
time executing subsidiary oscil-
its pointa of trisection, &c., as ^'^- ^^■
shown in fig. 19, for the fundamental and the first har-
monic.
TiO. The easiest means for oringing out the harmonics of
a string consists in drawing a violin-bow across it near to
ono end, while the feathered end of a quill or a hair-pencil
is held lightly against the string at the point which it is
intended shall furina node, and is removed just after the bow
is withdrawn. Thus, if a node is made in this way, at J
of AB from A, the note heard will be the twelfth. If
light paper rings be strung on the cord, they will be
driven by the vibrations to tlio nodes or points of rest,
which will thus bo clearly indicated to the eye.
CO. The formula "i - ^ shows that the pitch of the funda-
mental nolo of a wire of given length rises with the velocity
of propagation of sound through it. Now we have learned
(§ 28) that this velocity, in ordinarj- circumstances, is
enormously greater for a wire vibrating longitudinally than
for the same -mre vibrating transversely. The fundamental
note, therefore, is far higher in piitch in the former than in
the latter case. ,
As, however, the quantity V depends, for longitudinal
vibrations, solely on the nature of the medium, the pitch of
the fundamental not« of a wire rubbed along its length
depends — the material being the same, brass for instance —
on its length, not at all on its thickness, &c
But as regards strings vibrating transversely, such as
are mct^ with in our instrumental music, V, as we have
Been (§ 27), depends not only on the nature of the sub-
stance used, but also on its thickness and tension, and hence
the pitch of the fundamental, even with the same length
of string, will depend on all those various circumstances.
61. If we put for V its equivalent expressions before
given, we have for the fundamental note of transversely
vibrating strings :
21
.1 A
21 \/
^
whence the following inferences may be easily drawn:
If a string, its tension being kept invariable, have its
length altered, the fundamental note wiU rise in pitch in
exact proportion with its diminished length, that is, »
varies then inversely as /
Hence, on the violin, by placing a finger successively on
"4323 8 1
any one of the strings at -
5' 4' 3' 5' 15' 2' '^^
shall ob-
tain notes corresponding to numbers of vibrations bearing
to the fundameatal the ratios to unity of the following,
. 9543 15-,., , ,,
''^^> o> 7' Z> 7,1 "S"! ^) IV Inch notes form, therefore, with
o 4 o J o
the fundamental, the complete scale.
ni 62. By tightening a musical string, ita length remaining
v'Teoaion. unchanged, its fundamental is rendered higher. In fact,
then, n is proportional to the square root of the tension.
Thus, hj quadrupling the tension, the note is raised an
octave. Hence, the use of keys in tuning the violin, the
ngt pianoforte, (fee.
1 63. Equal lengths of strings of the same density and
thic'meM. equally stretched, but of different thicknesses, give funda-
mentals which are higher in pitch in proportion to dimi-
nution of thickness {i.e., n varies inversely as the thickness^
Thus, of two strings of same kind of gut, same length anti
same tension, if one be twice as thick aa the other, ita
fundamental will be an octave lower. Hence, three of tb«
strings of the violin, though all nf gut, have differen
fundamentals, because unequally thick.
64. Equally long and equally stretched strings or wires "*
of different thickness and different material, have funda- }
mentals higher in pitch the less the weights of the strings; ^*"«''*^'
n hero varies inversely as the square root of the weight a ^^i,
of a given length of the string.
65. If, in last case, the thicknesses of the strings mr
which are to be compared together are equal, then n vpries ^
inversely as the square root of the density. VJenaily.
Hence, in the violin and in the pianoforte, the lower
notes are obtained from wires formed of denser material.
Thus, the fourth string of the violin is formed of gut
covered with silver wire.
66. A highlj ingenious and instructive method 'for MeliS'aei-
illustrating the above laws of musical strings, has been perimcntal
recently contrived by M. Melde, and consists simply in '""'''™"
attaching to the ventral segment of a vibrating body,
such as a tuning-fork or a beU-gla."iS, a silk or cotton thread,
the other extremity being either fixed or passing over a
pulley and supporting weights by which the thread may be
stretched to any degree required. The vibrations of the
larger mass are communicated to tho thread which, by
proper adjustment of its- length and tension, vibrates in
unison and divides itself into one or more ventral segments
easily discernible by a spectator. H the length of the
thread be kept invariable, a certain tension will give but
one ventral segment; the fundamental note of the thread
is then of same pitch as the note of the body to which it
is attached. By reducing the tension to J of its previous
amount, the number of ventral segments will be seen to be
increased to two, indicating that the first harmonic of the
thread is now in unison with the solid, and consequently
that its fundamental is 'an octave lower than it was with
the former tension; thus confirming the law that n varies
as ;^/P. In like manner, on further lowering the tension
to J, three ventral segments will be formed, and so on.
The law that, aet. par., n varies inversely as the thick-
ness may be tested by forming a string of four lengths of
the single thread used before, and consequently of double
the thickness of the latter, when, for the same length and '
tension, the compound thread will exhibit double the nuxa-
ber of ventral segments presented by the eingle thread.
The other laws admit of similar illustration.
Paet ^^L
Slif Rods, Plates, <tc
67. If, instead of a string or thin wire, we make use of Kod, fiied
a rod or narrow plate, sufficiently stiff to resist flexure, we °' °"' ""*•
may cause it to vibrate
transversely when fixed
at one end only. In this
case the number of vi-
brations corresponding to
the fundamental note
varies as the thickness
directly, and as the square
of the length inversely.
The annexed figures re-
present the modes of vi-
bration corresponding to
the fundamental and the
first two overtones, the
rod passing to and fro
between the positions AGKC and AHLD.
In all cases .\
ACOUSTICS
113
Tuning-
fork.
Thinplates
figurea.
Square
plates
being fixed ia necessarily a node, and B being free is the
middle of a ventral segment. We have thus a succession
of cases in which the rod contains I, % », Ac. ventral seg-
ments. The numbers of vibrations per second are as the
squares of these, or, as 1 : 9 : 25 : &c. Tha reason of this
is, that (taking the case of fig. 20, 3) the part FB, which
may be regarded as an- independent rod fixed at the end
F, is evidently j of the length of A3, and consequently,
since n<x -, has a proper note of 5^ or 25 times the
rapidity of vibration in fig. 20, 1.
By attaching, with a Utile bees' wax, stiff hog's bristles
to one prong of a tuning-fork, or to the edge of a bell-
glass, or even a common jar, and clipping them on trial to
suitable lengths, we shall find that, on drawing a note in
the usual way from the tuning-fork or glass, the bristles
will divide into one or more separately vibrating segments,
as in the above figs.
68. The tvninrj-fork itself may be re-
garded as belonging to the class of stiff
rods. When emitting its fundamental
note, it vibrates, as in fig. 21, with nodes
at b and d and extreme positions ahcde
and fbgdh.
69. The transversal vibrations of thin
square, circular, and other plates of metal
or glass, are interesting, because, if these are
kept in a horizontal position, light dry sand
or powder sifted over the upper surface, will be thrown off
the ventral segments to the nodal lines, which will thus be
rendered manifest to the eye, forming what are termed
Chladni' I figures. As in the case of a musical string, so
here we find that the pitch of the npte is higher for a given
plate the greater the number of ventral segments into
which it is divided ; but the converse of this does not hold
good, two different notes being obtainable with the same
number of such segments, the position of the nodal lines
being, however, different.
70. The upper line of annexed figures shows how
the sand arranges itself in three cases, when the plates
are square. The lower line gives the same in a sort of
i
i 1
~^(
a
Fig. 22.
idealised form, and as usually to be found in acoustical
work.9. Fig. 22, 1 corresponds to the lowest possible note
of the particular plate used; Fig. 22, 2 to the fifth
higher; Fig. 22, 3 to the tenth or octave of the third,
the numbers of vib'^tion in the same time being as 2
to 3 to 0.
If the plate be small, it is sufficient, in order to bring
out the simpler sand-figures, to hold the plate firmly
between two fingers of the same hand placed at any point
where at lea.st two nodal lines meet, for instance the centre
in (1) and (2), and to draw a vioUn bow downwards across
the edge near the middle of a ventral segment. But with
larger plates, which alone will furnish the more complicated
figiu'cs, a dump-screw must be used fur fixing the plate, and.
Fig. 23.
at the same time, one or more other nodal points ought
to be touched with the fingers while the bow is being
ajiplied. In this way, any of the possible configurations
may be easily produced.
1\. By similar methods, a circular plate may be made Circular
to exhibit nodal lines dividing the surface by diametral P'*'*'.
lines into four or a greater, but always even, number of
sectors, an odd number being incompatible with the general
law of stationaay waves that the parts of a body adjoining
a nodal line on either side must always vibrate oppositely
to each other.
Another class of figures consists of
circular nodal lines along with dia-
metral (fig. 23).
Circular nodal lines unaccompanied
by intersecting lines cannot be pro-
duced in the manner described ; but may be got either
by drilling a small hole through the centre, and draw-
ing a horse-hair along its edge to bring out the note, or
by attaching a long thin elastic rod to the centre of the
plate, at right angles to it, holding the rod by the middle
and rubbing it lengthwise with a bit of cloth powdered
with resin, till the rod gives a distinct note ; the vibra-
tions are communicated to the plate, which consequently
vibrates transversely, and causes the sand to heap itself
into one or more concentric rings.
72. The theory of the vibrations of plates has not yet Theory
been put on a quite satisfactoiy basis. The following law ofCbladni
may, however, be regarded as confirmed by experiment, S'"'°'-
viz., that when two different plates of the same substance
present, the same nodal configuration, the numbers of
vibrations are to each other directly as the thicknesses, and
inversely as the superficial areas.
73. Paper, parchment, or any other thin membrane Vibrations
stretched over a square, circular, Ac, Irame, when in the "^ m^ni-
vicinity of a suflSciently powerful vibrating body, will,
through the medium of the air, be itself made to vibrate
in unison, and, by using sand, a" in previous instances,
the nodal lines will be depicted to the eye, and seen to
vary in form, number, and position with the tension of the
plate and the pitch of the originating sound. The mem-
brana tympani or drum of the ear has, in like manner and
on the same principles, the property of repeating the
vibrations of the external air which it co&municates to the
internal parts of the ear. •
74. Rods vibrating longitudinally are, as we have already Loig'tii-
remarked, subject to the laws of stationary waves. If, for J^.'°^' "'"'*
instance, a wooden rod fixed at one end, be rubbed near ^^^
the top betiveen the finger and thumb previously coated
with powdered resin, it will yield a fundamental note when
it so vibrates as to have only one node (at the fixed
extremity) and half a ventral segment reaching from that
extremity to the other, that is, when the length / of the
V
rod is ^ \, or \ = il, and therefore n = -j. But it may
also give overtones corresponding to 2, 3, <kc. nodes, the
free end being always the middle of a ventral segment,
and for which therefore the lengths of waves are -— , -r,
<tc. (as will be easily seen by referring to figs, in § 67,
which may equally represent transversal and longitudinal
displacements). Hence, the fundamental and harmonics
of a rod such as wo are now considering, have vibrations
whose rates arc as the succesiiive odd numbers.
A series of like rod.^, earli fixed at one end into a block
of wood, and of lengths bcnrijig to each other, the mtios
I : f : 'A'c. (as in § 61), will give the common scale when
rubbed in the manner already mentioned. This follows
V I
from the fundamental hann; « = ";, and therefore nx -z,
L - ■»
114
ACOUSTICS
Air it! the
essential
Bourcfl of
eotind in
pipes.
Principles
of Bcr-
nouilii's
theory.
Glas3 rods or tubes may also be made to vibr.ite longi-
tudinally by moans of a moist piece of cloth ; but it is
edvisable to clamp them firmly at the centre, when each
half will vibrate according to the eamo laws as the wooden
rods above. The existence of a motion of the particles of
glass to and fro in the direction of its length may be well
exhibited, by allowing a small ball of stone or metal
suspended by a string to rest against one extremity of the
rod, when, as soon as the latter is made to sing by friction,
the ball will be thrown 'off with considerable violence.
Past YIU.
Theory of Pipes.
75. The longitudinal vibrations of air enclosed in pipes
are of greater practical importance than those of other
bodies, because made available to a very great extent for
musical purposes. In the flute, horn, tnunpet, and other
wind instruments, it is the contained air that forms
the essential medium for the production of sound, the wood
or metal enclosing it having no other effect but to modify
the timbre or acoustic colour of the note.
7G. In dealing with the theory of pipes, we must treat
the air precisely in the same manner as we have dealt with
elastic rods vibrating lengthwise, a pipe stopped at both
ends being regarded as equivalent to a rod fixed at both
ends, a pipe open at both ends to a rod free at both ends,
and a pipe stopped at one end and open at the other to a
rod fixed at one end and free at the other. When there-
fore the air within the pipe is anywhere displaced along
the length of the pipe, two waves travel thence in opposite
directions, and being reflected at the extremities of the
pipe, there results a stationary wave with one or more
fixed nodal sections, on one side of which the air is at any
moment being displaced in one direction, while on the
other side it is displaced in the opposite. Hence, when
the air on both sides of the node _
is moving in towards it, there is
condensation going on' at the
node, followed by rarefaction on
the reversal of the motion of the
air. The full lines in annexed
figs, are curves of displacements,
the dotted lines curves of velocity
and density [vid. § 10 and 14).
As a stopped end prevents any
motion of the air, a nodal section
is always found there. And as.
Pipe
stopped at
both ends.
Fig. 24.
Oven pipe.
pipe
stopped at
ODo eod
only.
at the open end, we may coneaive the internal air to be
maintained at the same density as the external air, we may
assume that such end coincides with the middle of a ven-
tral segment.
From these assumptions, which form the basis of
Bemouilli's Theory of Pipes, we infer :
77. That in a pipe stopped at both ends, as in a rod
fixed at both ends, the fundamental ^^_ _^
note (fig. 25, 1), corresponds to X = 2/,
V
and therefore to n = ^ , V denoting
the velocity of sound in air, and the
overtones to numbers of vibrations
= 2n, Zn, and so on. Fig. 25, 2,
represents the octave.
78. That in a pipe open at both ends thcsame holds
good as in the previous case. For (fig. 26, 1) AC = J A
. •. X = 4 AC = 2^, and in fig. 26, 2, AD = ^ X, and also
= \ I .'. X = ;, or ^ its value for the fundamental' and
similarly for the other harmonics.
79. That in a pipe open at one end and stopped at
A 2J. B
the other (or, as it is usually termed, a flopped pipe, case S
77, being purely imaginary),
the fundamental note has n "
V
—, and the overtones corres-
pond to 3n, 5n. . . .
For, in fig. 27, 1, AB or
i - i X, and in fig. 27, 3, CB
or I X is evidently = \ AB or
\ I, whence X = \l, which being
\ of value of X in previous
case, shows that the number
of vibrations is three times greater,
other overtones.
80. It follows from the above, that
(whether open or stopped) may
to or in combina'.ion with its
fundamental, a series of over-
tones, which, in an open pipe,
and hence aie the octave,
twelfth, (kc, but, in a stopped
so as to want the octave and
other notes represented by the
even numbers. The succession of
practically obtained by properly regulating
Fig. 26
Similarly for the
a given pipe
Harraonici
in pipes-
Fig. 27.
overtones may
be
the force
the blast of air by which the air-column is put into
vibration.
81. If the fundamental notes of two pipes of equal
lengths, but of which one is open, the other stopped, be
compared together, they will be found to differ in pitch by
an octave, the stopped being the lower. This fact is in
keeping with the theory, for the numbers of vibrations
V V .
being respectively — and — , are in the ratio of 2 to 1.
82. Ey altering the length of the same pipe, we can
vary the pitch of the fundamental at pleasure, since n
varies inversely as I. This is effected in the flute and
some other wind instruments by means of openings along
part of the pipe, which, being closed or opened by means
of keys and of the fingers, increase or diminish the length
of the vibrating air-column. In this manner the successive
notes of the scale are usually obtained within the range of
an octave. The scale is further extended by bringing into
play the Jiigher harmonics.
V V
83. Since in an open pipe n = —, and therefore ' = 5"i
if for V we put 1090 ft., and for n 264, which is the
number of vibrations per second usually assigned to the
note C, we get i = 2 ft. very nearly. This, accordingly, is
the length of the so-called C open pipe. The C stopped
pipe must, by what has been stated above, be 4 feet in
length.
84. Conversely it is obvious that the velocity V of sound
in air, and generally in any gas, may be deduced from the
equation V = 2nl, and that if two pipes of equal length
contain respectively air and any other gas, the velocities
in the two media being, to each other directly as the
number of vibrations of the notes they respectively emit,
we may, from the well-ascertained value of the velocity in
air, determine in this way the velocities in other gases,
and thence the values of their coeflicients y (vid. § 21).
85. AMiile the inferences drawn by means of Bemouilli's
theory agree, to a certain extent, v.ith actual- observation,
there are discrepancies between the two which point to
the existence of some flaw in one or both of the hypotheses
on which the theory rests. In truth, the conditions
assumed by Bernouilli are such as do not fully occur in
Notes o.
open anc
stopped
p\\KS of
equal
lengths.
Length o»
C pipe.
Velocity la
any gaa
derived
from pipes.
Defects of
Bernooilli'ft
theory.
A^COUSTICS
115
practice. The stopped extremity of a pipe is aiways to
Bome extent of a yielding nature, and does not therefore
exactly coincide with a nodal surface; nor can the internal
air immediately adjoining the open end be perfectly free
from variation of density during the ■vibrations of the
whole mass,' particularly so at the embotichure, where the
blast is introduced by which the tone is originated. It
would appear from recent experiments that the pitch of a
pipe is somewhat lower than the above theory would
indicate.
Heed pipes. 86. The reed-pipe differs in many respects from the
simple pipe which we have been considering. A small
elastic strip of metal, fixed at one extremity (the reed),
lies over a slit of the same shape, and is set in transverse
vibration by a current of air acting underneath. If, as is
the case in the accordion and harmonium, the reed is un-
provided with a pipe, the pitch of its note is regulated
altogether by the dimensions of the reed, in conformity
with the law of tranversely vibrating plates ; although, it
is to be remarked, the note is reaUy due to the vibrations
of the air which alternately escapes through the slit of the
reed, and is prevented doing so exactly as often as the
reed executes a movement to and fro. The proper note of
the reed itself is very poor and faint.
Inflaenceof 87. In the reed-pipe there is added above the reed a pipe
pipe on tiie air in which partakes of the vibratory motion, and im-
" ■ proves the quality of the sound. The pitch is, however,
not affected by this pipe, unless it exceed a certain length
I, when the pitch begins to fall, and continues to do so as
I is, increased, tUl, when the length of pipe is 21, the note
is again restored to its original pitch, &c.
Weber's 88. 5J. Weber, to whom we are indebted for these and
theory of other curious facts respecting reed pipes, has explained
'"^P'l* them thus:— If the reed be exactly at that part of the
vibrating air-column where the air-displacements are at
their maximum, and where consequently the air suffers no
variation of density during the vibratory motion of the
column, the oscillations of the reed are not. at aU affected
by the air-vibrations, and consequently the pitch of the
reed-pipe is the same as that of the reed itself. But if the
reed be situated at any other part of the air-column, and
especially at a nodal section, where the air is undergoing
alternate -condensation and rarefaction, then, when the air-
blast from the wind chest pushes in the reed, the air in
the pipe is in the act of rarefaction, and consequently tends
to accelerate the reed inwards, whereas the elasticity of
the reed tends in an opposite direction. When, again, the
reed is passing to the other extreme of its vibration, the
air in the pipe is in the act of condensation, and tends to
accelerate the reed outwards or in the opposite direction to
the elasticity of the reed. Hence the reed is affected just
as if its elasticity, and therefore the rapidity of its vibra-
tions, were dimiijished, and thus the pitch is lowered.
Paet IX.
Singing Flames.
Om har- 69. The chemical or gas harm/>nicon, which consists of
monicoD. ^ small flame of hydrogen or of coal gas, burning at the
lower part of the interior of a glass tube, and giving out a
very distinct not«, exhibits considerable analogy with the
reed-pipe. For, as Sondhaus seems to have established,
the primary cause of the note lies in the oscillations of the
gas within the burner and the feeding-pipe, which there-
fore play exactly the same part as does the roed portion of
the reed-pipe. The air in the glass tube being heated by
the flame ascends, and the pressure above the flame being
thence diminished, the flame is forced upwards by the gas
beneath, until an influx of atmospheric air at the top of
ihe tube forces the flame back. Thus a periodic agitation
of the flame ensues, accompanied by a corresponding di£-
turbance of the air-column in the glass tube. The size of
the flame and its position within the tube must be so
regulated as to bring out the best possible note, which will
then be found to be the same as the air in the tuV'C would
itself emit, according to the laws of pipes, allowance being
made for the high temperature of the air. A „8ries
of tubes may thus be arranged of suitable lengths to give
the ■ common scale. It sometimes happens, particularly
with short tubes, that the note will not come out spontanu- •
ously, all that is required, then, is either by blowing gently
at the top of the tube, or by singing in unison with the
expected note, to give to the air the requisite initial move-
ment
The flame, which burns steadily with a yellowish light
before the tube sounds, will, as soon as the note is heard,
be seen to flicker up and down, changing rapidly from
yellow to blue and blue to yellow, its intensity also chang-
ing periodically. These fluctuations are best seen by view-
ing the image of the flame reflected by a small plane mirror,
held in the hand and moved to and fro. Before the note
is heard, the image of the then quiescent flame, being im-
pressed on different points of the retina, appears as a con-
tinuous luminous strip ; but, when the harmonicon speaks,
the various images become quite detached from one another,
showing that the portion of the retina over which the
reflected light passes is sensibly affected only at certain
points of it, which evidently correspond to the instants of
time at which the flame, in its periodical fluctuations, is at
its brightest.
90. Naked flames, that is, flames unaccompanied by tubes. Naked
may also give out musical notJS, and many singular in- flames,
stances are mentioned by Tyndall and others of their
sensitiveness to external sounds.
91. Koenig of Paris has constructed an apparatus in- Flame
tended to indicate the modes of vibration of the different manom^tefl
parts of vibrating bodies, such as columns of air, &c., by
means of flames,, and to which he has given the name of
the Flame Manometer. We will here describe its applica-
tion to the case of organ-pipes. An open pipe has three
apertures along one side, one at the middle, o (fig. 28), i.e.,
at a node of the fundamental tone, and the two others, a, b,
half way between o and the extremities of the , ,
pipe, and coinciding therefore with the nodes of
the first overtone or octave. These openings, are
closed by thin flexible membranes forming the
ends of small boxes or capsules, the spaces within
which communicate by caoutchouc tubes with a
coal-gas reservoir, and also by separate tubes with
small gas burners arranged on a vertical stand.
The gas being introduced, and the three flames
of an inch; if the pipe be made now to utter its first over-
tone, the flame connected with o will remain stationary
and of the same brightness as before, but those communi-
cating with a and t will become longer and thinner, and
assume a bluish and faint luminosity. But, if the funda-
mental be brought out of the pipe, then it is o's flame
that is violently affected, while those of a and b are scarcely
affected at all. If the flames be originally made les^ in
height (say J inch), those of a and b in the former case, and
of in the latter, will be extinguished. These results are
due to the condensations and rarefactions of the air in the
pipe which arc at their maximum at a node, causing tha
membrane placed there to vibrato outwards and inwards,
and hence to force more or less of the gas into the burner.
In order to compare together the notes of different pipes,
four plane reflecting surfaces are connected together in tha
form of a cube, which is mounted on a vertical axis about
i which it is capable of being turned round. Kach pipe 15
Fig. 23.
116
ACOUSTICS
furnished wilii oue opening, a mcmoraue, iS:c. (as above),
at ita middle. As pointed out (§ 87), if any of the pipes
be made to sound, the reflector being at the same time put
in motion, a series of separate , images will be seen. On
Bounding another pipe, \t'hose fuiidamcutal ia an octave
higher, we shall have a second line of images separated
from each other by half the interval of those in the former
series. This is best observed when the two flames are placed
in the same vertical lino. If the note of the second pipe
is a fifth higher than the first, and consequently its vibra-
tions to those of the fir^t as 3 to 2, then the same space
which contains two images of the lower note will contain
tliroe of the higher, and so on, for other combinations.
AVhen more complicated ratios are to be tested, it is pre-
ferable to connect both capsules with the same burner,
either with or without the reflector.
Paet X.
Communication of Vibrationt.
Coramuni- 92. The cominujucation of sonorous vibrations from one
cation be- body to another plays so essential a part in acoustics that
tween j^ f^^ words must here be given to the subject. It appears
2oUdi and '" ^^ ^*'^ established that while the vibrations of e solid
liooiilk. '"'o in general most readily communicated to other solids
in contact with it, they are not so to liquids, and still less
80 to air and other aeriform fluids. Thus, a tuning-fork
is inaudible at any moderate distance unless applied to a
table, by whose extended surface the air can be more
intensely affected. So likewise a musical string sounds
Tery poorly unless connected with a re.sonant cavity or
•wooden chest, to the wood of which it first imparts its
vibratorj' motion, which then produces stationarj- waves in
the continued air.
Kunilt'sex- 93. A few years ago M. Kundt made known a method
pcriments. Jounded on the communicability of vibration, by which
the velocities of sound in different media may be compared
together with great facility. Take a glass tube 3 feet or up-
wards in length, drop into it a small quantity of the fine
powder of the club-moss or lycopodium, and turn the tube
round so as to spread the powder over the internal surface
of the tube. Stop both ends of the tube with corks, clamp
it at its centre, and rub one of its halves lengthwise with
a moist cloth, so as to cause the glass to sound a note. It
Avill then be found that, the air within the tube taking up
the motion, and a stationary wave being formed in it, the
]>owder is driven off from the ventral segments and forms
little heaps at the nodes. The dust-heaps are, by the laws
of stationaiy waves, separated therefore from each other
by intervals each equal to half the length of an air-wave, or
- . If. then, the number of heaps = m, and the length
21
of the tube = / : A = — .
m
But, by the laws of longitudinal vibrations of rods, the
lengtn X' of the glasS-wave =4(-j = 2;. Hence — = m,
that is, the number of dust-heaps is equal to the ratio of
the lengths of a wave of sound in glass and in air, and
consequently to the ratio of the velocities of sound in those
media. (For the vibrations being in unison, their number
in a given time must be the same for the glass and the
. . V V
air, t.«., -^ = ^ ; V, V being the velocitiesl
Kundt found 16 to be the number of heaps; prior
experiments of a different kind had, as we have before
mentioned, given this as the number of times that the
velocity of sound in glass exceeds its velocity in air.
Instead of producing the air-vibrations by friction of the
tube containing the air, it ia preferable to make use of a
smaller tube or rod, furnished with a cork at one end, which
tits like a ]jiston into the tube, and projecting at its ontei
end through an opening in the cork which closes the air-
tube. The rod thus inserted is the one which is rubbed
longitudinally and communicates its vibrations to the air
in the enclosing tube. By means of an apparatus of this
kind, Kundt determined the ratio to the velocity of sound
iji air of its velocity in various solids, and also (replacing
the air in the tube bv different gases) of its velocity in
these gases.
Pabt XL
InUrferenee of Sound.
94. When two or more sonorous waves travel through Meaning of
the same medium, each particle of the air being simultane- interfe^
ously affected by the disturbances due to the different '"*''•
waves, moves in a difl'erent manner than it would if only
acted on by each wave singly. The waves are said mutually
to interfere. We shall exemplify this subject by consider-
ing the case of two waves travelling in the same direction
through the air. We shall then obviously be led to the
following results : —
95. If the two waves are of equal length X, and are in Two wavM
the same phase (that is, each producing at any given of equal
moment the same state of motion in the air-particles), their '""gtlu.
combined effect is equivalent to that of a wave of the same
length X, but by which the excursions of the particles are
increased, being the
sum of those due
to the two com-
ponent waves re-
spectively.
If the two inter-
fering waves, being
still of same length
X, be in opposite
phases, or so that ^* ^'•
one is in advance of the other by -, and consequently one
produces in the air the opposite state of motion to the
other, then the resultant wave is one of the same length
X, but by which the excursions of the particles are de-
creased, being the difference between those duo to the
component waves. If the amplitudes of vibration which
thus mutually interfere are moreover equal, the effect is
the total mutual destruction of the vibratory motion.
Thus we learn that two musical notes, of the same pitch,
conveyed to the ear through the air, will produce the effect
of a single note of the same pitch, but of increased loudness,
if they arc in the same phase, but affect the ear very
slightly, if at all, when in opposite phases. If the differ-
ence of phase be varied gradually from zero to -X, the result-
ing' sound will gradually decrease from a maTunnni to •
minimum.
96. Among the many experimental confirmations which Eiperi-
may be adduced of these proportions,
we will mention the foDowing: —
Take a circular plate, such as is
available for the production of Chladni's
figures (§ 71), and cut out of a sheet
of pasteboard a piece of the shape
ABOCD (fig. 30), consisting of two
circular quadrants of the same diameter
as the plate. Let, now, the plate be
made in the usual manner to vibrate so as to exhibit two
nodal lines coinciding with two rectangular diameters. If
the ear be placed right above the centre of the plate, the
sound will be scarcely audible. But, if the pasteboard be
interposed so as to intercept the vibrating segments AOB,
DOC, the note becomes much more distinct. The reason
mental il-
lustrations.
Vibrating
plat«.
'Fig. »0.
ACOUSTICS
117
Hopkins's
experi-
ment.
TuDiDg
fork.
Double
BjTen.
Fhme
tn.iDometer.
Interfer*
enco of two
Beta ot
vibrations
for wliich
n m
of this is, that the segments of tie i:.late AOD, BOC
always vibrate in the same direction, but oppositely to
the segments AOB, DOC. Heijce, when the pasteboard
is in its place, there are two waves of same phase starting
from the two former segments, and reaching the ear after
equal distances of transmission through the air, are again
in the same phase, and produce on the car a conjunct im-
pression. But when the pasteboard is removed, then there
is at the ear opposition of phase between the first and the
second pair of waves, and consequently a minimum of sound,
97. A tubular piece of wood shaped as in fig. 31, and
having a piece of thin membrane stretched over
the opening at the top C, some dry sand being f\
strewn over the membrane, is so placed over a (i\\
circular or rectangular vibrating plate, that the v ^
ends A, B lie over the segments of the plate,
such as AOD, COB in the previous fig., which ^'*- ^^'
axe in the same state of moticm. The sand at C will
be set in violent movement. But if the same ends
A, B, be placed over oppositely vibrating segments (such as
AOD, COD), the sand will be scarcely, if at all, affected.
93. If a tuning-fork in vibration bo turned round before
the ear, four positions will be found in which it will be
inaudible, owing to the mutual interference of the oppo-
sitely vibrating prongs of the fork. On interposing the
hand between the ear and either prong of the fork when
in one of those positions, the sound becomes audible, be-
cause then one of the two interfering waves is cut off from
the ear. This experiment may be varied by holding the
fork over a glass jar into which water is poured to such a
depth that the air-column within reinforces the note of
the fork when suitably placed and then turning the fork
round.
99. Helmholtz's double syi-en (§ 51) is well calculated
for the investigation of the laws of interference of sound.
For this purpose a simple mechanism is found in the in-
strument, by means of which the fixed upper plate can be
turned round and placed in any position relatively to the
lower one. If, now, the apparatus be so set that the notes
from the upper and lower chest are in unison, the upper
fixed plate may be placed in four positions, such as to
cause the air-current to be cut off in the one chest at the
exact instant when it is freely passing through the other,
and vice versa. The two waves, therefore, being in opposite
phases, neutralise one another, and the result is a faint
Bound. On turning round the upper che.->t into any inter-
mediate position, the intensity of the sound will increase
lip to a maximum, wliich occurs when the air in both chests
is being admitted and cut off contemporaneously.
100. If two pipes, in exact unison, and furnished with
flame manometers, are in communication with the same
wind-cliest, and the two flames be placed in the same
vertical line, on introducing the current from the bellows,
we shall find that the two lines of reflected images will be
BO related that each image in one lies between two images
in the other. This shows that the air-vibrations in one
pipe are always in an opposite phase to the other, or that
condensation is taking place in the one when rarefaction
occurs in the other. This arises from the current from the
bellows passing alternately into the one and the other pipe.
There v/ill also be a remarkable collapse of the sound
when both pipes communicate with the wind-chest com-
pared with that produced from one pipe alone.
101. If the two interfering waves are such as produce
vibrations whose numbers per second are n, n respectively,
these being to each other in the ratio of two integers m, m
when expressed in its lowest terms, then the lengths of the
waves X, \' being inversely as n to Ji', will be to each
other as 7n' -.m, and consequently mX^m'V. Particles
thercfoie of the air separated by this distance from each
other will be in the same phase, that is, the length of tha
resvltant wave wUl be m A or m \', and if N denote the
corresponding number of vibrations N = — or — .
Thus, for the fundamental and its octave -7 =
n
therefore N = re or •— ; that is, the note of interfereuca
is of the same pitch as the fundamental.
For the fundamental and its major third, — = -. Hence
mental ar-*
N
or -— , that is, the resulting sound is two octaves
Tonda-
Tiiental and
majortbir'
lower than the fundametaL
For the fundamental and its maior sixth, — = -; n
mental anct
therefore
and the resultinj
niajor
sound is a twelfth ^ixth.
below the lower of the two interfering notes.
if m and hi' differ by 1 , then N = » - ?j' ; for m - m
or X = — - .-7- . Hence, if the ratio of the vibrations ^^^ °^,
N N m-m-
of two interfering sounds is expressible in its lowest tei'ms
by numbers whose difl'erence is unity, the resulting note
has a number of vibrations simply coual to the difference
of those of the interfering notes.
The results stated irrthis section may be tested on a har-
monium. Thus, if the notes B, C, at the extreme right of
the instrument be struck' together, there will be heard an
interference note four octaves lower in pitch than the
above C, because the interval in question being 'a semi-
tone, is -{-f , and, consequently, by last case, the interferencu
note is lower than the C by interval -j'j
Other notes may be heard resulting from the mutual
interference of the overtones.
102. When two notes are not quite in tune, the resultingBeats^
sound is found to alternate between a maximum and mini-
mum of loudness recurring periodically. To these periodic^^l
alternations has been given the name of Beats. Their
origin is easily explicable. Suppose the two notes to cor-
respond to 200 and 203 vibrations per second; at some
instant of time, the air-particles, through which the waves
are passing, will be similarly displaced by both, and coa-
sequently the joint effect will be a sound of some intensity.
But, after this, the first or less rapidly vibrating note will
fall behind the other, and cause a diminution in the joint
displacements of the particles, till, after the lapse of ^ of)
a second, it will have fallen behind the other by A a vibnt.
tion. At this moment, therefore, opposite displacements
will be produced of the air-particles by the two notes, and
the sound due to them will be at a minimtun. This will
be followed by an increase of intensity until the lapse of
another sixth of a second, when the less rapidly vibrating
note will have lost another half-ribration relatively to the
other, or one vibration reckoning from the original period
of thne, and the two component vibrations wUl again con-
spire and reproduce a maximum effect. Thus, an inter-
val of ^ of a second elapses between two successive maxima
or beats, and there are produced three beats per second.
By similar reasoning it may be shown that the number of
beats per second is always equal to the difference between
the numbers of vibrations in the same time corrcspondiiiij
to the two interfering notes. The more, therefore, these
are out of tune, the more rapidly'will the beats follow each
other.
Beats are also heard, though less distinctly, when other
concorfls such as thirds, Ji/l/is, i-c, are not perfectly in tune j
thus, 200 vibrations and 303 vibrations j'cr second, which
form, in combination, an imperfect fifth, produce h°sti
occurring at the rate of three oer secnn j
118
ACOUSTICS
Examples
of beatA.
Tuning by
beats.
Irri tiling
fffect of
rapid beats
103. The phenomena of boats may be coajy observed
with two organ-pipes put slightly out of tune by placing
the hand near the open end of one of them, with two
musical strings on a resonant chest, or with two tuning-
forks of same pitch held over a resonant cavity (such as a
glass jar, vid. § 97), one of the forks being put out of tune by
last instance, if the forks are fixed on one solid i)iece of wood
which can be grasped with the hand, the beats will be
actually felt by the hand. If one prong of each fork be
furnished with a small plain mirror, and a beam of light
from a luminous point bo reflected successively by the two
mirrors, so as to form an image on a distant screen, when
orie fork alone is put in vibration, the image will move on
the screen and bo seen as a line of a certain length. If
both forks are in vibration, and are perfectly in tune, this
line may either bo increased or diminished permanently in
.length, according to the difference of phase between the
two sets of vibrations. But if the forks be not quite in
tune, then the length of the imago will be found to fluc-
tuate between a maximum and a minimum, thus making the
beats sensible to the eye. The vibrograph (§ 52, 53) is
also well suited for the same purpose, and so in an especial
manner is Helmholtz' double syren (§ 51), in which, by
continually turning round the upper box, a note is pro-
duced by it more or less out of tune with the note formed
by the lower chest, according as the handle is moved more
or less rapidly, and most audible beats ensue. The gas
harmonica and the flame manometer also afford excellent
illustrations of the lav.-s of beats.
101. Advantage has been taken of these laws for tht
pnrpose of determining the absolute number of vibrations
per second corresponding to any given nolo in music,
whence may be derived the number for all the other notes
(§ 45). The human ear may be regarded as most correctly
appreciating two notes differing by an octave. Two tuning-
forks then are taken, giving respectively the note A and
its lower octave, and a number of other forks are prepared
intermediate in pitch to these, say 54, and by means of
bees' -wax these are so tuned, that the first gives four beats
with the A fork, the second four beats with the fourth, and
so on up to the last, which also gives four beats with the
A_, fork. Now, if n = the unknown number of vibrations
for the note A, n- i; n-8 ... n - 55 x 4, will be the
numbers for all the successive forks down to the A_j fork,
which being an octave below A, we have — ■ = Jand
consequently n = 440.
105. Beats also afford an excellent practical guide in the
tuning of instruments, but more so for the higher notes of
the register, inasmuch aj the same number of beats, that
is, the same difference between the numbers of vibrations,
for two notes of high pitch, indicates greater deviation
from perfect unison, than it does for two notes of low
pitch. Thus, two low notes of 32 and 30 vibrations
32 16
respectively, whose interval is therefore — or — i.e., a semi-
tone, give two beats per second, while the same number of
beats are given by notes of 32 x 16 (four octaves higher
than the first of the preceding) or 512 and 514 vibrations,
which are only slightly out of tune.
1C6. As the interval between two notes, and con-
sequently the number of beats increases, the effect on thn ear
becomes more and more unpleasant, and degenerates at last
into an irritating rattle. With the middle notes of the musical
register, this result occurs when the niunber of beats comes
np to 20 or 30 per second, the musical interval between
the two interfering notes being then between half and
a whole tone. Helmholtz attributes the disagreeable im-
pression of beats on the ear, to the same physiological cause
to which is due the painful effect on the eye of a faint
flickering light, a.s, for instance, the Ught streaming through
a wooden paling with intervening openings when the
individual affected ia passing alongside. In this case, the
retina, which, when continuously receiving the same amount
of light, thereby loses its sensitiveness in a great degree, ia
unable to do so.
It is, however, remarked by the above-mentioned author
that the same number of beats, which has so irritating an
effect when due to two notes in the middle of the register,
is not attended by the same result when duo to notes of
much lower pitch. Thus, the notes C, D forming k tone
give together 33 beats per second, while a note two octavea
lower than C also gives 33 beats v^ith its fifth; yet the
former combination forms a discord, the hitter a most
pleasing concord.
107. When the number of beats reaches to 132 or Differenw.
upwards per Bocond, the result is a continuous and not lone*,
unpleasing impression on the ear, and it was formerly heia
tliat the effect .was always equivalent to that of a note
having that number of vibrations. Helmholtz has shown
that this opinion is inaccurate, except when the interfering
tones are very loud, and consequently accompanied by
Very considerable displacements of the particles of the
vibrating medium. These resultant tones being, as to
their vibration-number, equal to the difference between the
numbers corresponding to the two primaries, are termed
differcTice-tones, and may be best ob6er^"ed with the double
syren. The same author was led also, on theoretical
grounds, to surmise the formation of tummalion-tonet by Surama-
the iirtcrference of two loud primaries, the number of tion-tooes.
resultant vibrations being then equal to the sum of the
numbers for the two components, and appealed for experi-
mental proof to his syren. But, at the last meeting of the
British Association (1872), Koenig, the celebrated Parisian
acoustician, maintained that the notes of the syren, thus
held to be summation-tone.s, were in reality the diftrence-
tones of the harmonics.
108. By reference to the laws of the interference of Helm-
vibrations, Helmholtz has been enabled to offer a highly holtz't ei.
satisfactory explanation of the cause whence arises dii- Pj^'tion
ference of quality or timbre or acoustic colour between ^\^^
different sounds. He has shown conclusively that there
are but few sounds which are of a perfectly simple character,
that is, in which the fundamental is not accompanied by
one or more overtones. Now, when a note is Bimple, there
can be no jarring on the ear, because there is on room for
interference of sound. Hence, the softness of the tuning-
fork when its fundamental is reinforced by a resonant
cavity, and also of the flute. The same character of soft-
ness belongs also to those instruments in which the powerful
harmonics are limited to the vibration ratios 2, 3 ... G
(§ 57, 80); because the mutual interference of the funda-
mental and their harmonics give rise to concords only.
The piano, the open organ pipe, the violin, and the softer
tones of the human voice, are of this class. But if the odd
harmonics alone are present, as in the narrow stopped
organ pipe, and in the clarionet, then the sound is poor,
and even nasal; and if the higher harmonics beyond the
sixth or seventh are very marked, the result is very
harsh (as in reed-pipes).
109. The human voice {iot a description of the organ in Voice,
which it originates, we refer to Art. Phytiology — Voice and
Speech)ia regarded by the best authorities as being analogous
to a reed-pipe, the vocal chords forming the reed, and the
cavity of the mouth the pipe, and, like the reed, is rich in
harmonics, as many as sixteen having been detected in a basa
voice. But their number and relative intensities differ much
in different individuals, or even in the same person at dif-
ferent times; and it is on this variety that, agroeablv to Helm-
ACOUSTICS
119
Vowel
jounds.
holtz's theory of timbre, the peculiarities depend by which
any cue voice may be unmistakably distinguished from
every other. Voices in which overtones abound are sharp,
aud even rough ; those in which they are few or faint, are
soft aud sweet. In every voice, -however, the number and
relative intensity of the overtones depend on the form
assumed by the cavity of the mouth, which acts relatively
to the vocal chords precisely as a resonator does to a
tuning-fork, or a pipe to a reed. This may be easily tested
by holding a tuning-fork before the open mouth, when,
by giving to the cavity a suitable form, the fundamental
or some overtone of the ,fork may be heard distinctly
reverberated from the interior of the mouth. Each vowel
sound, as Helmlioltz hfis shown, is simply the result of
the reinforcements by the air in the csmty of the mouth,
and its prolongation towards the larynx, of one or in some
cases two overtones of determinate pitch, contained in the
sound which proceeds from the vocal chords. Koenig
assigns the following notes as characteristic of the _^
eimpler vowel sounds (adopting the foreign pro- ^ ^
nunciation) : — To U, the note Bb below the line Jji
ia the G clef, corresponding to 225 vibrations
t-o-
per second; to O, the next higher octave, consequently of
double the number of vibrations, and thence ascending
by octaves for A, E, and I, the last of which is therefore
characterised by r* iiote of 3600 vibrations per second.
The above the.'iry cf vowel sounds may be satisfactorily
confirmed by me'ins of tuning-forks, vibrating in front of
resonant cavities, which can, by suitabU combination, be
made to utter any vowel sound.
Works on Acoustics.
Herschel, Sir John, Encycl. Metrop., art. " ^ound." Lon-
don, 1830.
TyiidaU, Lectures on Sound, 2d edit. London, 1869
Helmholtz, Die Lehre von der Tomempfindumjen, 3d edit
Braunschweig, 18V0, of which there is a Frenck trans-
lation, and an EnjjUsh one is promised.
Besides the above, SDme account of the subject is to be
found in such general works on Physics as Ganot's, 14th
Longmans,- London ; Deschanel's Natural Philosophy,
translated by Prof. Evirett, London, 1873; Jamin, Co^rt
ds Physique, 3d edit., Paris, 1871; Wiilner Physik, 2d
edit., Leipzig, 1870. d. t.'*
An-, essential for hearing,
8
velocity of sound in,
17, 18, 22
A i^iplitude of vibrations,
i
Beats, how produced; .
102
examples of.
103
application to finding n fo
any note,
IM
cuning by.
105
rapid effect of, on ear,
IDS
Bell in vacuo,
3
Cbemical harmonicon, .
87
69 to 71
Communication of Tibrationg,
92, 93
De la Tour's syren.
49
Density, variations in, by longitu
dinal vibrations,
1,4
Diatonic scale,
46
Difference tones, .
106
Dove's syren,
50
Echoes
38
■Elasticity
15
Flames, singing, .
89, 90
Flame manometer.
91, 103
Fundamental note,
67
Gas harn!ionica, .
87. 103
Gases, velocity of sound in, .
21,84,93
Harmonics in strings, .
57 to 60
rods.
67
pipes.
77 to 80
Harmony, laws o?,
45, 46
Helmholtz, his double syren.
61, 99
on resultant tones.
107
on timbre.
108
Intensity of sound—
at different distances,
29
in air of different densities,
30
promoted by sheet of water, &c.
depends on amplitude of vibra
89
tions, ....
41
Interference of sound —
laws of, . . . .
94, 95
examples of, .
Intervals, musical,
98 to 100
45
Kosnig's phonautograph,
name manometer, .
53
91, 100
denial of summation-tone
>, 107
Kundt's experiments, .
93
Laplace's corrected velocity o
f
sound in air, .
16
Lenseff, acoustic, .
34
Liquids, velocity of sound in,
25
Longitudinal vibrations.
9,28
ALPHABETICAL INFEX.
The numerals refer lo the sections.
Loudness {vid. intensity).
Strings, musical, comparison of fun-
Melde's experiments on vibrating
damental notes
strings, .....
66
due to trans-
Membranes, vibrations of, .
72
versal and -lon-
Musical sounds and noises, .
44
gitudinal vib-
notes, vibration-ratios of.
45
rations, .
60
Nevrton's investigation of velocity
influence on pitch
in air,
16
of length, ten
Nodes
54
sion, &c.,
61
Noises and musical sounds, .
44
Melde's experi-
mental illus-
Overtones (vid. harmonics).
ParaboUc reflectors, . •
37
trations.
66
Phase
7
Spheroidal reflectors. .
38
Phonautograph, ....
50
Summation tones,
106
Pipes, BernouiUi's theory of, .
75
Syren of Seebeck,
48
stopped (at both enda) .
77
of De la Tour, .
49
open, ....
78
of Dove, . . . .
50
stopped, ....
79
■of Helmholtz, .
61
harmonics in, .
80
Thunder, roll of, .
40
open and stopped, of equd
Timbre,
43, 108
lengths, ....
81
Tones, major, minor, and semi, .
46
infl'aence of length of, on pitch.
82
Transversal vibrations.
9, 28
length of C pipe.
83
Tuning by beats
105
defects of theory.
85
Tuning-forks, mode of vibration, .
68
illustrations by manometer.
91
interference in
97
Pitch, depends on «, .
42
beats in.
103
Plates, square, vibrations of.
69
70
"V entral segments, , , ,
64
circular, do.
71
Vibrations, sound due to, .
2
interference in.
96
97
laws of, .
4, 6
Rankine's investigation of velocity
of pendulum, .
4
of sound
16
transmission of.
6
Reeds and reed-pipes, .
86 to 88
longitudinal and trans-
Reflexion, la«s of, . . .
3S-
39
versal, .
9
total
33
relation between fre-
Refraction, laws of, . . .
31 to 34
quency of, and length
RodB, transversal vibrations of, .
67
of wave.
13
longitudinal vibrations of, .
74
communication of,
92, 98
Savart's toothed wheel apparatus,
47
number of, for any note
Scales, diatonic and chromatic.
46
determined by beats.
104
Seebeck's syren, ....
48
Vibrograph
62
Solids, velocity of sound in (longi-
Voice, its seat in vocal chords.
109
tudinal),
<s6
26
Vowel sounds, how accounted for.
109
Solids, velocity of sound in (trans-
versal), .....
Water, velocity of sound in.
30
27
28
"Waves of displacement,
10, 12
Solids, velocity of sound in, Kundt'i
of velocity,
11, 12
method
92
of condensation and rare
Stationary waves, . . •
.64
faction.
14
Strings, musical, laws of.
55 to 66
lengths of,
10
fundamental and
relation of, to n.
13
overtones of, .
57
68
propagation of, .
18
overtones how
Weber's theory of reed-pipes,
88
obtained from.
59
120
A C Q — A C K
ACQUI, 8 town of Northern Italy, in the province of
AJessaudria, 18 miles S.S.W. of the city of that name, on
the left bank of the Bormida. It is a jihco of ^cat
antiquity; and its hot sulphur baths, which are still much
frequented, were known to the Romans, who gave the place
the name of Aquw Statiellw. There are still to be found
numerous ancient inscriptions, and the remains of a Roman
aqueduct. The tovra is the seat of a bishop, and has a fine
cathedral, several convents, and a royal college. Good
wine is produced in the ■i-ineyards of the district, and great
attention is given to the rearing of silk-worms. There are
also considerable silk manufactures. Population, 8600.
ACRE, a measure of surface, being the principal deno^
mination of land-measure used in Great Britain. The
word (akin to the Sa.\on acer, the German acl-rr, and the
Latin ager, a field) did not originally signify a determinate
quantity of land, but any open ground. The English
standard or imperial acre contains 4840 square yards, or
10 square chains, and is also divided into roods, of which
it contains 4, the rood again being divided in 40 perches.
The imperial acre has, by the Act 5 Geo. IV. c. 74, super-
seded the acres, of very different extent, that were in use
in different parts of the country. ' The old Scottish acre
was equal to 1'26118345 imperial acres. The Irish acre
contains 7840 square yards The acre is equivalent to
•40467, i.e., about f ths, of the French hectare (now the basis
of superficial measurement in Germany, Italy, and Spain,
as well as in France), "7 of the Austrian joch, '37 of the
Russian desdiine, and 162 ancient Roman jugera. The
hectare correspond.? to 2 acres 1 rood 35 'SS perches.
ACRE, Akka, or St Jeam D'Acbe, a town and seaport
of Syria, and in ancient times a celebrated city. No town
has experienced greater changes from political revolutions
and the calamities of war. According to some this was the
Accho of the Scriptures ; and its great antiquity is proved
by fragm(?nt3 of houses that have been found, consisting of
that highly sun-burnt brick, with a mixture of cement and
sand, which was only used in erections of the remotest
^ges. It was known among the ancients by the name of
Ace, but it is only from the period when it was taken posses-
sion of by Ptolemy Soter, king of Egypt, and received
from him the name of Ptolemais, that history gives any
certain account of it. When the empire of the Romans
began to extend over Asia, Ptolemais came into their pos-
session. It is mentioned by Strabo as a city of great
importance; and fine granite and marble pillars, monu-
ments of its ancient grandeur, are still to be seen. During
the Middle Ages Ptolemais passed into the hands of the
Saracens. They were expelled from it in 1110 by the
it until 1187, when it was recovered by Saladin. In 1191
it was retaken by Richard L of England and Philip of
France, who purchased this conquest by the sacrifice of
100,000 troops. They gave the town to the knighta of St
John of Jei-usalem, from whom it received the name of St
Jean P'Acre. In their possession it remained for a century,
though subject to continual assaults from the Saracens.
It was at this time a large and extensive city, populous and
wealthy, and contained numerous churches, convents, and
hospitals, of which no traces now remain. Acre was finally
lost to the Crusaders in 1291, when it was taken by the
Saracens after a bloody siege, during which it suifered
severely. From this time its prosperity rapidly decUned.
In 1517 it fell into the hands of the Turkish sultan, Selim
I.; and in the beginning of the 18th century, with the
exception of the residences of the French factors, a mosque,
and a few poor cottages, it presented a vast scene of ruin.
Towards the end of that century Acre was much strength-
ened and improved by the Turks, particularly by Djezzar
PacJia, and again rose to some importance. It is memor-
able in modem history for tne gaiiantry with which it was
defended in 1799 by the Turks, as.sisted by Sir Sydney
Smith, against Bonaparte, who, after spending sixty-one
days before it, was obliged to retreat. It continued to
enjoy an increasing degree of prosf>erity till 1832. Though
fettered by imf>osts and monopolies, it carried on a con-
of the great states of Europe. On the revolt of Mehemet Ali,
the pacha of Egj-pt, Acre was besieged by his son, Ibrahim
Pacha, in the winter of 1831-32. The siege lasted five
months and twcnty-ono days, and, before the city was
taken, its public and private buildings were mostly destroyed.
Its fortifications were subsequently repaired and improved
■ by the Egyptians, in whose hands it remained until 3d Nov.
1840, when the town was reduced to ruins by a three hours'
bombardment from the British fleet, acting as the aUies of
the sultan. The Turks were again put in possession of it
in 1641.
Acre is situated on a low promontory, at the northern
extremity of the Bay of Acre. The bay affords no shelter
in bad weather; and the port is scarcely capable of contain-
ing a dozen boats. Vessels coming to this coast, therefore,
generally frequent the anchorage of Caiffa, on the south
side of the bay. Acre is 80 r.iilcs N.N.W. of Jerusalem,
and 27 S. of Tyre. Population, 10,000.
ACROBAT (from uKpo/SaTt'w, to walk on tiptoe), a rope-
dancer. Evidence exists that there were very skilful per-
formers on the tight-rope (/unamhvli) among the ancient
Romans. Modern acrobats generally use a long pole,
loaded at the ends, and by shifting this are enabled to
maintain, or readily to recover, their equilibrium. By an
extension of the meaning of the term, acrobatic feats now
include trapeze leaping and similar performances.
AC'PkOCERAUNIA, in Ancient Geography, a promon-
torj' in the N.W. of Epirus, which terminates the Montes
C'eraunii, a range that nins S.E. from the promontory
along the coast for a number of miles, and is supposed to
have derived its name from being often struck withlight-
niug. The cape (now called Glossa by the Greeks, and Ziii-
guetta by the Italians) is in lat. 40° 25' N.
ACROGEN^E is the name applied to a division of acoty
ledonous or crypt ogamous plants, in which leaves are pre-
sent along with va.scular tissue. In the higher divisions of
Acrogens, as ferns and lycopods, the tissue consists of scalari-
form vessels, while in the lower divisions spiral cells are
observed, which take the place of vessels. The term Aero-
gen means summit-grower, that is, a plant in which the
stem increases specially by the summit. This is not. how-
ever, strictly accurate.
ACROLITH (a.Kp6\i6oi), statues of a transition penod
in the history of plastic art, in which the trunk of the
figure was of wood, and the head, hands, and feet of
marble. The wood was concealed either by gilding or,
more commonly, by drapery, and the marble parts alone
were exposed. Acroliths are frequently mentioned by
Pausanias, the best known specimen beine the Minerva
Areia of the Platseans.
ACRCJN, a celebrated physician, bom at Agngentum
in SicUy, who was contemporary with Empedocles, and
musti therefore have lived in the 5th century before Christ
The successful measure of lighting large fires, and purify-
ing the air with perfumes, to put a stop to the pestilence
that raged in Athens (430 ac), is said to have originated
with him; but this has been questioned on chronological
grounds. Pliny is mistaken in saying that Acron was the
founder of the sect of the Empiric!, which did not exist
until the 3d century before Christ. The error probably
arose from a desire on the part of the sect to establish for
itself a greater antiquity than that of the Dogmatici.
Suidas gives the titles of several works written by Acroa
A C R — A G T
121
on medical subject3, m the Doric dialect, but none of
these now exist
ACROPOLIS (^ AicpoVoXts), a -n-ora signifying tne upper
town, or chief place of a city, a citadel, usually on the
Bummit of a rock or hiU. Such buildings were common in
Greek cities; and they are also found elsewhere, as in the
case of the Capitol at Rome, and the Antonia at Jerusalem;
but the most celebrated was that at Athens, the remains of
which stOl delight and astonish travellers. It was enclosed
by walls, portions of which show traces of extreme antiquity.
It had nine gates; the principal one was a splendid struc-
ture of PenteUcan marble, in noble Doric architecture,
which bore the name of Propylaia. Besides other beauti-
ful edifices, it contains the TlapBevuiv, or temple of the
virgii goddess Athens, the most glorious monument cf
a&cient Grecian architecture.
Ground plan of tho Acropolis ci Athens.
a, PedSfltBl of Rome and Augustus.
b, c, oC, Sites cf tciuples of ^liDerra,
Di&na, and Venus,
t. Erecthcium.
/, Dlonysiac theatre,
ff, Odeon of Herodca.
h and 0, Grottoes.
i, Ruined mosque.
t, ?, Gate and portico,
m, Clioragic monument of Thrasyclet,
now cliurcli of our iady of the grotto,
n, n, Remains of Pelasgic wall,
y, t[. WaUs of outworjte, Ac.
«, Gate to Propylsea.
?, r, i. Forts.
tt, o, Ancient vralla.
ACROSTIC (from axpos and otlxk, meaning literally
the extremity of a verse), is a species of poetical composi-
tion, so constructed that the initial letters of the lines,
taten consecutively, form certain names or other particular
words. This fancy is of considerable antiquity, one of the
most remarkable examples of it being the verses cited by
Lactantius and Eusebius in the 4th century, and attri-
buted to the Erythr33an sibyl, the initial letters of which
form the words 'Irjcrov? Xptcrrog &€ov vto5 o-tim^p : *' Jesus
Christ, the Son of God, the Saviour," with- the addition,
according to some, of (pra-upoi, "the cross." The initials
of the shorter form of this again make up the word ix^u's,
to which a mystical meaning has been attached (Augustine,
De Civitate Dei, 18, 23), thus constituting another kind
of acrostic. Tho arguments of ita comedies of Plautus,
with acrostics on the names of the respective plays, are
probably of still earlier dato. Sir John Daviea (1070-
1G26) wrote twenty-six elegant Hymns to Aslracc, each an
acrostic ou " Elizabetha Regina;" and Mistress Mary Fage,
in Fame's Houle, 1637, commemorated 420 celebritii.'S ot
her time in acrostic verses. The same form of .composition
Ls often to bo met with in Ae writings of more recent
versifiers. Sometimes, the lines are so combined that the
final letters as well as the initials are significant. Edgar
Allan Poe, with characteristic ingenuity, worked two
names — one of them that of Frances Sargent Osgood — into
verses in such a way that the letters of the names corre-
sponded to the first letter of the first line, the second letter
of the second, tho third letter of the third, and so ou.
Generally speaking, acrostic verse is not of much value,
and is held in slight estimation. Dr Samuel Butler says,
in his " Character of a Small Poet," " He uses to lay the
outsides of. his verses even, like a bricklayer, by a liie of
rhyme and acrostic, and fill the middle with rubbish."
Addison (Spectator, No. 60) found it impossible to decide
whether the inventor of the anagram or the acrostic were
the greater blockhead; and, in describing the latter, says,
' ' I have seen some of them where the verses have not only
been edged by a name at each extremity, but have had the
same name running down Like a seam through the middle
of the poem." And Dryden, in Mac Flecknoe, scornfully
'' Some peaceful province in acrostic land."
The name acrostic is also applied to alphabetical or
" abecedarian" verses. Of these wo have instances in some
of the Hebrew psalms {e.ff., Ps. xxv. and xxxiv.), the
successive verses of which begin with th2 letters of the
alphabet in their order. The structure of Ps. cxix. is still
more elaborate, each of the verses of each of the twenty-
two parts commencing with the letter which stands at the
head of the part in our English translation. Alphabetical
verses have been constructed with every word of the suc-
cessive lines beginning with the successive letters of the
alphabet.
By an extenaed use of the term acrostic, it is applied
10 the formation of words from the initial letters of other
words. 'Ix^"''i referred to above, is an illustration of this.
So also is the word " Cabal," which, though it was in use
before, with a similar meaning, has, from the time of
Charles II., been associated with a particular ministry,
from the accident of its being composed of CUiford, Ashley,
Buckingham, Arlington, and Lauderdale. Akin to this
are the names by which the Jews designated Uieir
Rabbis ; thus Rabbi Moses ben Maimon (better known
as Maimonides), was styled " Rambam," from the initials
R. M. B. M.; Rabbi David Kimchi (R, D. K,), " Radak," <fec.
A species of puzzle, scarcely known twenty years ago,
but very common now (see English Catalogue, 1863-71, s. v.
Acrostics), is a combination of enigma and double acrostic,
in which words are to be guessed whose initial and final
letters form other words that are also to be guessed. Thus
Sleep and Dream may have to be discovered from the first
and last letters of Sound, Lover, Europe, Elia, and Palm.,
aU expressed enigmatically.
ACT, in Dramatic Literature, signifies one of those
parts into which a play is divided to mark the change of
of time or place, and to give a respite to the actors and to
the audience. In Greek plays there are no separate acts,
the unities b-eing strictly observed, and the action being
continuous from beginning to end. If the principal actors
left the stage the chorus took up the argument, and con-
tributed an integral part of the play, though chietiy in the
form of comment upon the action. When necessary,
another drama, which is etymologically the same as an act,
carried o^ the history to a later time or in a different place,
and thus we have the Greek trilogies or groups of three
dramas, in which the same characters reappear. The
Roman poets first adopted the division into acts, and sus-
pended the stage business in the intervals between them.
Their number was usually five, and the pile was at last
laid down by Horace in the Ars J'oetica —
*' l^evo minor, neu eit quinto productior acta
FuL^Jo, quiB posci vult, et epectata repom."
" I;' you would have your play deserve succeaa,
Qivo it five acta complete, Dor more nor less. "
— 'J'YancU.
On tho seviya] of letteis this rule was almost nniversally
observed by dramatists and that there is an inherent coa
I. — i6
122
A C T — A C T
veiiience and fitncs's ia tho number fivo is evident irom the
fact that Shakespeare, who refused to be trammelled by
merely arbitrary rules, adopts it in all his plays. Some
critics hu fe laid down rules as to tho part each act should
Bustain iu the development of tho plot, but theso are not
essential, and are by no means universally recognised. In
comedy tho rule as to the number of acts has not been so
strictly adhered to as iu tragedy, a division into two acts
or three acts being quite usual since the time of Molicrc,
•who first introduced it.
It may bo well to mention hero Milton's Samson Aganutea
as a specimen in English literature of a dramatic work
founded on a purely Greek model, in which, consequently,
there is no division into acts.
ACT, in Law, is an instrument in writing for declaring
or justifying tho truth of anything; in which sense records,
decrees, sentences, reports, certificates, kc, are called acU.
The origin of the legal use of the word Act Ls in the acla
of the Roman magistrates or people, of their courts of law,
or of the senate, meaning (1) what was done before thn
magistrates, the people, or the senate; (2) the records of
such public proceedings.
ACT OF PARLLUIENT. An Act of ParUament may
bo regarded as a declaration of the Legislature, enforcing
certain rules of conduct, or defining rights and conferring
them upon or withholding them from certain persons or
classes of persons. The collective body of such declara-
tions constitutes tho statutes of the realm or written law
of the nation, in tho widest sense, from Anglo-Sa.xon times
to the present day. It is not, however, till Magna Charta
that, in a more limited constitutional sense, the statute-
took is generally held to open, and the Parliamentary
records only begin to assume distinct outlines late in the
reign of Edward I. The maladministration of the common
law by the royal judges hr.d gradually taught the people
the uecessity of obtaining written declarations of their
rights — often acknowledged, still oftener violated. Insen-
sibly almost, tho Commons, whose chief function it origin-
ally was to vote supplies to the crown, began to couple
their grants with petitions for tlie redress of grievances.
The substance of these petitions and of the royal responses
was in time made the groundwork of Acta which, as framed
by court redactors, and appearing annexed to proclamation-
writs after the dissolution of Parliament, were frequently
found seriously to misrepresent its will. To check this
evil an Act was passed (8 Henry IV.), authorising the
Commons to be represented at the engrossing of the Par-
liament roll; but even this surveillance was not enough,
for in the beginning of the reign of Henry V. it was enacted,
at the instance of the Commons, that in regard, to their
petitions the royal prerogative should in future be limited
to granting or refusing them simpliciter. In this way it
became a fixed constitutional principle that an Act of Par-
liament, to be valid, must express concurrently the will of
the entire Legislaiure. It was not, however, tQI the reign
of Hjnry VI. that it became customary, as now, to intro-
duce bills into Parliament in the form of finishec" Acts ; and
the enacting clause, regarded by constitutionalists as the
first perfect assertion, in words, of popular right, came into
general use as late as the reign of Charles IX It is thus
e.xpreGsed: — "Be it enacted by the King's most excellent
Majesty, by and with the advice and consent of the Lords
Sjiiritual and Temporal and Commons in this present Par-
liament assembled, and by the authority of the same."
The use of the preamble with which Acts are usually pre-
faced, is thus quaintly set forth by Lord Coke, — " The
rehearsal or preamble of the statute is a good meane to
find out the meaning of the statute, and, as it were, a key
to ojicn the understanding thereof." Originally, the col-
lective Acts of each session formed but one statute, to
which a general title was attached, and for this reason an
Act of Parliament is always cited as the chapter of a par-
ticular statutc^.y., 24 and 25 Vict. c. 101. Titles were,
however, prefixed to indiridual Acts as early as 1488.
Since 33 Geo. III. c. 13, an Act of Parliament is com-
plete whenever it receives the royal assent, and takes effect
from that date, unless the Act itself fix some other. British
Acts require no formal promulgation, for it is presumed that
every subject of the realm is cognisant of the resolutions
of Parliament, either by himself or his representativo
therein.
Modem Acts of ParUament are — 1. Public. These are binding on
all citizens, and are ex ojlcio cognisable by the judges. Since 1850
every Act is held to be public unless the contrary be expreaaly declared.
2. Private Acts. Theso relate to particular classes, persons, or places.
Private Acts ore (1.) Personal, viz., those which relate to name,
naturalisation, estate, kc, of particular persons. (2.) Ix>cal, affect-
ing bridges, canals, docks, turnpikes, railways, kc To j^revent such
Acti from being unduly passed, the promoters of private bills arj
required to comply with tho standing orders of the two Houses, by
which private bill procedure is regulated. Acta cf Parliament, fur
convenience of reference, ore cla.«ified as Public General Acts, Local
and Personal Acts declared Public, Private Acts printed, and Privala
Acts hot printed. Public General Acts (if no exception be expressed),
extend to Great Britain and Ireland, exclusively only of tho Channel
Islands and tho Isle of Man.
The firot complete edition of English Acts of Parliament published
by state authority appeared between the years 1810 and 1824. it
includes the eaily charters, and ends with the reign of Queen Anne.
Many private editions* of tho statutes had appeared previous to that
of the Record Commissioners. The practice of printing Acts of Par-
li.iment commenced in the reign of Richard III. The charters and
Acts \^re vnitten in Latin till the Slaintum de Scaccario, 51 Henry
III. (1266), which is in French. The Acts of Edward I. are indis-
criminately in Latm or French ; but from the fourth year of Henry
VII. Acts are exclusively in English.
Scotch Acts. — The earliest attempts at a written record of the pro-
ceedings of the ParUament of Scotland consisted of detached instru-
ments or indentures, and the next step was the entering of these
detached instruments on a roU for more permanent preservation.
Xo such record, however, is preserved before the disputed succes-
sion, which commenced in 1269. The earliest roU of placita in
parliainento is dated 1292 ; but the Blak Buik, containing a seriea
of proceedings in Parliament from 1357 to 1402, is the most im-
portant of th£ earliest records of ParUament. The original books of
ParUament of the reigus of James I. and James 11. are not preserved,
but from the year 1466 down to the Union a voluminous, but not
unbroken, series has been preserved. Down to the reign of Jamea
v., scarcely any Act in the original registers is distinguished by a.
title or rubric ; and even after that period the practice has not ia
this respect been uniform. In like manner there ia no numeration
of the Acts of ParUament during this period. The language of the
earliest Scotch records is in Latin ; but as early as 1398 some of tha
proceedings of ParUament or the Council-General were written in
Scots,- and subsequently to 1 424 always in that language. Unlike tho
English Acts, French was never used in Scotch lepslation. In 1541
a selection of the Acts of James V\ was printed. The lirst edition of
the Acts was published in 1566, the second in 1597, the third ia
1681 ; and the great national work, the complete record of Parlia-
ment, has just been completed, with a general index to the whold
.\ct3 from 1124 to 1707, which forms the great rei>ertory of the
legal, constitutional, and poUtical history of Scotland. In 1540 an
Act was passed requiring all the Acts of Parliament to be pronounced
in presence of the king and the estates, — the assent of the king
being indicated by his touching them with the sceptre ; and in 1641 it
was ordained that the Acts passed in 1640 be publi-shcd in the king's
name, and with the consent of the estates. But during the civil
war thi Acts of ParUament were passed in name of the estates alone.
These Acts, however, were rescinded after the restoration of Charles
H. by Act 1661, c. 126, because "the power of making laws is an
essential privilege of the royal prerogative." In 1457 an Act was
passed for procLiuning the Acts of Parliament in tha shires and
burghs, that none be ignorant; and in 1581 it was ordained that
Ai;ts need not be proclaimed at the market-cross of the head burgh
of each shire, but at the market-cross of Edinburgh only, the lieges
obeying them forty days thereafter. The clerk of register was
ahvay3''bound to give extracts of Acts to the Ueges in their parti-
cular affairs. In 1425 a committer consisting of an equal number
of each estate, was appointed to amend I.Ko books of law: and in
1567 a commission was issued to codify the laws, ci\-il and muni-
cipal, dividing them into heads like the Roman law,— the beads ai
they are ready to be brought to Parliament to be confirmed. Lord
Bacon recommended the Scotch .A.ct3 for their "exceLent brevity,'.'"
His loidihiiJ's praise appUes very properly to the Acts down to the
A C T -r- A C T
123
reign of Queen Mary and the early part of the reign of James Vi. ;
but the logomachy of Bubsequent legislation is intolerable to the
consxilter.
Irish Acts may be said to commence A.D. 1310, in the reign of
Edward II., and to close with the union with the British Parlia-
ment in 1801. From the former d3.te, however, there is a break
tUl 1429. In 1495 Foyning's Law provided that no bill should
he introduced into the Iriah Parliament which has not pre-
viously received tho royal assent in England ; and till 1782 the
Parliament of Ireland remained in tut*;lage to that of England.
Since 1801 it has been incorporated with the Parliament of Great
Britain.
ACT OF SEDERUNT, in Scotch Law, an ordinance for
regulating the forms of procedure before the Court of
Session, passed by the judges in virtue of a power con-
ferred by an Act of the Scotch Parliaiiient, 1540, q. 93. In
former times this power was in several instances clearly
exceeded, and such Acts of Sederunt required to be rati-
fied by the Scotch Parliament; but for more than a century
and a half Acts of Sederunt have been almost exclusively
confined to matters relating to the regiilation of judicial
procedure. Many recent statutes contain a clause empower-
ing the court to make the necessary Acts of Sederunt. A
quorum of nine judges is required to pass an Act of
Sederunt.
ACTS OF THE APOSTLES, the fifth among the
canonical books of the New Testament. What has to be
said on this book will naturally fall under the following
heads: The state of the text; the authorship; tho object
of the work ; the date and the place of its composition.
The State of the Text. — The Acts is found in two MSS.
generally assigned to the 4th century, the Codex Sinai-
ticus, in St Petersburg, and the Codex Vaticanus, in Rome ;
in one MS. assigned to the 5th century, the Codex Alex-
andrinus, in the British Museum ; in two MSS. belonging
to the 6th century, the Codex Bezce, in Cambridge, and
the Codex Laudiamu, in Oxford ; and in one of the 9 th
century, the Codex Palimpsest us Porfirianus, in St Peters-
burg, with the <exception of chapter first and eight verses
of chapter second Large fragments are contained in a
MS. of the 5th century, the Codex Ephroemi, in Paris.'
Fragments are contained in five other MSS., none of which
is later than the 9th century. These are all the uncial
MSS. containing the Acts or portions of it.
The MSS. in Oxford and Cambridge differ widely from
the others. This is especially the case with the Cambridge
MS., the Codex Bezoe, which is said to contain no less
than six hundred interpolations. Scrivener, who has edited
this MS. with great care, says, " WMe the general course
of the history and the spirit of the work remain the same
as in our commonly received text, we perpetually encounter
long passages in Codex Bezoe which resemble that text
only as a loose and explanatory paraphrase recalls the
original form from which it sprung; save that there is no
difi'erence in the language in this instance, it is hardly an
exaggeration of the facts to assert that Codex D [i.e.,
Codex jB«ob] reproduces the textus receptus of the Acts
much in the same way that one of the best Chaldeo
Targums does the Hebrew of the Old Testament, so wide
are the variations in the diction, so constant and inveterate
the practice of expanding the narrative by means of inter-
polations." Scrivener here assumes that the additions of
the Codex Bezoe are interpolations, and this is the opinion
of nearly all critics. There is one, however, Bornemann,
who thinks that the Codex Bezos contains the original
text, and that tho others are mutilated. But even sup-
posing that we were quite euro that tho additions were
interpolations, the Codex Bezoe makes it more difficult to
determine what the real text was. Scrivener, with good
reason, supposes that the Codex Bezce is derived from an
original which would most likely belong to the third cen-
tury at the latest
Authorship of the Work. — In treating this subject we
begin with the external e\idence.
The first mention of the authorship of the Acts in a well-
authenticated book occurs in the treatise of Iren;eus against
heresies, written between the years 182 and 188 a.d.
Irenseua names St Luke as the author, as if the fact were well
known and undoubted. He attributes the third Gospel to
him, and calls him " a follower and disciple of apostles " (II.
iiL 10, 1). He states that "he was inseparable from Paul,
and was his fellow- worker in the gospel " {M. iii. 14, 1 ).
The next mention occurs in the Siromata of Clemens
Alexandrinus, written about 195 A.D., where part of St
Paul's speech to the Athenians is quoted with the words,
" Even as Luke also, in the Acts of the Apostles, records
Paul as saying" {Strom, v. xii. 82, p. 696, Pott). The
Acts of the Apostles is quoted by TertuUian as Scripture,
and assigned to St Luke {Adv. Mar. v. 2 and 3). Origen
speaks of " Luke who wrote the Gospel and the Acts "
(Eus. H. E. vi. 25); and Eu.sebius includes the Acts of
the Apostles in his summary of the books of the New
Testament {Hist. Eccl. iii. 25). The Muratorian canon,
generally assigned to the end of the second or beginning of
the third century, includes the Acts of the Apostles, assigns
it to St Luke, and says that he was an eye-witness of the
facts recorded. There is thus unanimous, testimony up to
the time of Eusebius that St Luke was the author of the
Acts. This unanimity is not disturbed by the circum-
stance that some heretics rejected the work, for they did
not deny the authorship of the book, but refused to
acknowledge it as a source of dogmatic truth.
After the time of Eusebius we find statements to the
effect that the Acts was little knowiL " The existence
of this book," Chrysostom says, " is not known to many,
nor the person who wrote and composed it." And Photius,
in the ninth century, says, " Some maintain that it was
Clement of Rome that was the writer of the Acts, others
that it was Barnabas, and others that it was Luke tho
Evangelist."
Irenaeus makes such copious quotations from the Acts
that we can feel sure that he had before him substantially
our Acts. We cannot go further back than Irenaeus with
certainty. If, as we shall see, the writer of the Acts was
also the writer of the third Gospel, we have Justin Martyr's
testimony (about 150 a.d.) for the existence of the third
Gospel in his day, and therefore a likelihood that the Acts
existed also. But -we have no satisfactory evidence that
Justin used the Acts, and there is nothing in the Apostolic
Fathers, nor in any work anterior to the Letter of tni
Churches of Vienne and Lyons, written probably soon after
177 A.D., to prove the existence of the Acts.
The weight of external evidence therefore goes entirely
for St Luke as the author of the Acts. But it has to bo
noticed, that the earliest testimony is more than a hundred
years later than the events described in the Acts. We
have also to take into account that Ireneeus was not
criticaL We find him calling tho Pastor of Bermas Scrip-
ture; Clemens Alexandrinus also calls the Pastor inspired;
and Origen not merely attributes inspiration to the work,
but makes tho author of it tho Hennas mentioned in the
Epistle to the Romans. All scholars reject the testimony
of Ireneeus, Clemens Alexandrinus, and Origen in this
matter. The question arises. How far are we to trust
them in others of a similar nature 1
We turn to the internal evidence. And in the very
commencement we find the author giving himself out as
tho person who wrote the third Gospel. This claim has
been almost universally acknowledged. There is a remark-
able similarity of stylo in both. The same peculiar modes
of expression continually occur in both; and throughout
i both there exist continual references backward and for-
124
ACTS OF THE APOSTLES
■ward, wliich imply the same authorship. There are some
difficulties in the way of this conclusion. Two of these
deserve special notice. If wo turn to the last chapter of
the Gospel, wo find it staled there (ver. 13) that two dis-
ciples met Jesus on the d-iy of the resurrection, as they
were going to Emmaus. Towards nightfall (ver. 29) he
entered the village with them; and as ho reclined with
them, he became known to them, and disappeared.
Whereupon "at that very hour" (ver. 33) they rose up and
returned to Jerusalem. They found the eleven assembled,
and told them what had happened to them. " AVliile they
■were saying these things, he himself stood in the midst of
them" (ver. 36). The apostles gave him a piece of fish,
and he ate it. "But he said to them" (ver. 44), so the
narrative goes on, and it then relates his speech; and at
ver. 50 it says, " He led thorn out to Bethany," and then
disappeared from tliem. This disappearance was final;
and ii the words used in tjie Gospel make us hesitate in
determining it to bo his ascension, such hesitation is
removed by the opening words of the Acts. According
to the Gospel, therefore, all tho events now related took
place, or seem to havo taken place, on the day of the
resurrection, or they may possibly have extended into the
next morning, but certainly not later. • The Acts, on the
contrary, states that Jesus was seen by tho disciples for
forty days, and makes him deliver the speech addressed to
kis disciples and ascend into heaven forty days after the
resurrection. The other instance is perhaps still more sin-
gular, lu the Acts we have three accounts of the conversion
of St Paul — the first by the writer himself, the other two by
St Paul in his speeches. The writer states that (ix. 4, 7)
when the light shone round Paul, he fell to the ground,
" but the men who were journepng with him stood dumb."
St Paul himself says (xxvi. 14) that they aU fell to the
ground. The writer says (ix. .7) that St Paul's com-
panions heard the voice, but saw no one. St Paul himself
says (xxii. 9) that his companions saw the light, but did
not hear tho voice of him who spake to him. And finally,
all these accounts diller in their report of what was said
on the occasion. Notwithstanding these difl'erences, even
these very accounts contain evidence in them that they were
written by the same writer, and they do not destroj' the force
of the rest of the evidence. The case would be quite different
if Baur, Schwegler, and Wittichen were right in supposing
that the Gospel of Luke contained documents of opposite
tendencies. It would then be necessaiy to assume different
authors for the different parts of the Gospel, and stiU- an
other for the Acts. But this theory falls to tho ground if
tlie Tubingen theory of tendencies is rejected.
The Acts itself claims to be ■written by a companion of
St Paul. In chap. xvi. 10, the writer, without any previous
warning, passes from the third person to the first. St Paul
him to go to Macedonia. " But when he saw the ■vision,
straightway we sought to go out into JIacedonia." The
use of the " we" continues until Paul leaves PhilippL In
chap. XX. Paul returns to PhUippi, and the "we" is
resumed, and is kept up till the end cf the work. Irenceus
{H. iii. 14, 1) quotes these passages as proof that Luke,
the author, was a companion of the apostle. The minute
character of the narrative, the accurate description of the
various journeyings, tho unimportance of some of the
details, and the impossibility of contriving aU the inci-
dents of the shipwreck without experiencing them, are
strong reasons for believing that we have the narrative of
an eye-witness. And if wa allow this much, we can
scarcely help coming to the conclusion that this eye-\\'itnes3
Ava-i the author of the work; for tho style of this eye-witness
is exactly the style of the writer who composed the prei-ious
portions. Suiae have supposed that we have here the per-
gonal narrative of Timothy or of Silas; but this supposition
would compel us to believe that the writer of the Acts was
so careless as to tack documents together without remem-
bering to alter their form. Such a procedure on the part
of the skilful writer of the Acts is unlikely in the highest
degree. The "we" is introduced intentionally, and can
bo accounted for only in two ways : either by supposing
that the writer was an eye-witness, or that he wished to
be thought an eye witness, and borrowed the narrative of
an eye-witness to facilitate the deception. Zeller has
adopted this latter alternative; and this latter alternative
is the only possible one for those who assign a very late
date to the Acts.
We may test the writer's claim to be regarded as a com-
panion of St Paul by comparing his statements with those
of the other books of tho New Testament. As might be
expected, tho great facts recorded in the Gospels are repro-
duced accurately in the Acts. There is only one marked
diUerence. St Matthew says (xxvii. 5, 7) that Judas cast
the traitor's money into the temple, and the priests bought
with it a field for the burial of strangers. St Peter in Acts
(i. 18) says, that Judas himself purchased a field with the
reward of his iniquity. St Matthew says that he went and
hanged himself, St Peter that he fell headlong and burst in
the middle. St Matthew says, or rather seems to say, that
the field was called the field of blood, because it was pur-
chased with blood-money; St Peter seems to attribute the
name to the circumstance that Judas died in it.
The Acts is divided into two distinct parts. The first
deals ■nith the church in Jerusalem, and especially narrates
the actions of St Peter. We have no external means of
testing this portion of the narrative. The Acts is the only
work from which information is got in regard to these
events. Tho second part pursues the history of the apostle
Paul; and here we can compare the statements made in the
Aces with those made in the Epistles. Now here again we
have a general harmony. St Paul travels in the regions
where his Eputles show that he founded churches. The
friends of St Paul mentioned in the Acts are also the
friends acknowledged in the Epistles. And there are
many minute coincidences. At the same time, we learn
from this comparison that St Luke is not anxious to give
minute details. Timet) v probably visited Athens wliile
St Paul was there. Th. we learn from 1 Thess. iii 1 , but
no mention is made of this visit iu the Acts. Again, we
gather from the Epistles to the Corinthians that St Paul
paid a visit to Corinth, which is not recorded in the Acts.
Moreover, no mention is made of Titus in the Acts. These,
however, are slight matters; and it must be allowed that
there is a general agreement. But attention has been
drawn to two remarkable exceptions. These are the ac-
count given by St I'aul of hb visits to Jerusalem in the
Epistle to the Galatians and that given by St Luke; and
the character and mission of the apostle Paul, as they
appear in his letters and as they appear in the Acts.
In regard to the first point, St Paul himself says in the
Epistle to the Galatians, that after his conversion straight-
way he held no counsel with flesh and blood, nor did he
go up to Jerusalem to the apostles who were before him;
but he went away to Arabia and returned to Damascus; that
then after three years he went up to Jerusalem to seek for
Cephas, and he remained with him fourteen days. He at
that time saw only two apostles, — Peter, and James the
brother of the Lord. He then went away to S)Tia and
Cilicia, and was unknown by face to the churches of Judea.
He says that fourteen years after this he went up to Jeru-
salem with Barnabas, taking Titus with him. On this
occasion he went up by revelation. St Paul introduces
these facta for a purpose, and this purpose is that he
might prove his inde])eiidcuce as an apostle.^ H e had acted
ACTS OF THE APOSTLES
125
solely on the revelation given to himself. He had neither
required nor obtained sanction from the other apostles,-
He was an apostle, not sent forth from men nor through
men, but through Jesus and God. When we turn to. the
Acts, we find that no mention is made of the journey to
Arabia. He stays some days at Damascus, and then
begins to preach the gospel. He continues at this work a
considerable time; and then, in consequence of the plots
of the Jews, he secretly withdraws from Damascus and
proceeds to Jerusalem. The brethren there are suspicious
in regard to him, and their fears are not quieted until
Barnabas takes him to the apostles; and after this intro-
duction he goes in and out amongst them, and holds dis-
cussions with the Hellenists. Finally, when the Hellenists
attempt to kill him, the brethren send him to Tarsus. In the
Epistle to the Galatiaus St Paul does everything for him-
self, instigated by his inward feeUngs. In the Acts he is
forced out of Antioch, and sent by the brethren to Tarsus. In
the GalatianS St Paul stays only a fortnight, and' sees only
St Peter and St James of the apostles, and "was imknown by
face to the churches of Judea. In the Acts Barnabas takes
him to the apostles, and he continues evidently for a period
much longer than a fortnight, going in and out amongst
them. Then in chap. xi. 30, he goes up a second time to
Jerusalem, — a visit which seems inconsistent with the narra-
tive in the Epistje to the Galatians. And finally, when he
goes up to Jerusalem, the Acts does not represent bim
going up by an independent revelation, but as being sent
up; ^nd it says nothing of his taking an independent part,
but represents hin. ag submitting to the apostles.
This, however, leads us to the treatment of the character
of St Paul by the writer of the Acts. Soma of the
Tubingen critics assert that the writer shows ill-wiU to St
Paul, but they are evidently wrong. Oil the contrary, the
character of the apostle as given in the Acts is fuU of gi-and
and noble traits. Yet still there are some singular pheno-
mena in the Acts. St Paul claimed to be an apostle by the
will of God. He had as good a right to be an apostle as
Bt Peter or St James. Yet the writer of the Acts never
calls him an apostle in the strict sense of the term. He
is twice called an apostle, namely, in Acts liv. 4 and
14. On both occasions his fellow-apostle is Barnabas;
but' Barnabas was not one of the twelve, and not an
apostle in the strict sense- of the term. And even in
these verses the reading is doubtful The Codex Beice
omits the word apostle in the 14th verse, and makes
the 4th liable to suspicion by inserting an addition to it.
St Luke also brings prominently forward as the proper mark
of an apostle, that he should have companied with the Lord
from his baptism to his ascension, and describes the filling
up of the number of the twelve by the election of Matthias.
And if St Luke's narrative of St Paul's conversion be
minutely examined, it will be perceived that not only does he
not mention that St Paul saw Jesus, but the circumstances
13 related scarcely permitted St Paul to see Jesus. He
was at once dazzled by the light, and fell to the ground.
[n this prostrate condition, with his eyes shut, he heard the
voice; but at first he did not know whose it was. And
when he opened his eyes, he found that he was bUnd. The
words of Ananias imply that St Paul really did see Jesus,
but 6t Luke abstains from any such statement. And St
Paul is not treated by the Jewish Christians in the Acts as
an independent apostle. He is evidently under submission
to the apostles at Jerusalem.
Furthennoro, the point on which St Paul specially insists
in the Epistle to the Qalatians is, that ho was appointed the
apostle to the Gentiles as St Peter was to the circumcision,
and that circumcision and the observance of the Jewish law
were of no importance to the Christian. St Paul's words on
this point in all his letters are strong and decided. But in
the Acts it is St Peter that opens up the way for the Gentiles.
In St Peter's mouth occurs the strongest language in regard
to the intolerable nature of the law. Not a word is said of
the quarrel between St Peter and St Paul. The brethren in
Antioch send St Paul and Barnabas up to Jerusalem to ask
the opinion of the apostles and elders. St Paul awaits the
decision of the apostles, and St Paul and Barnabas, cany
back the decision to Antioch. And throughout the whole
of the Acts St Paid never stands forth as the champiou
of the Gentiles. He seems continually anxious to reconcile
the Jewish Christians to himself, by observing the law of
Moses. He circumcises Timothy, and he performs his
vows in the temple. And he is particularly careful in his
speeches to show how deep his respect for the law of
Moses is. In this regard the letters of St Paul are very
different from his speeches as given in the Acts. In the
Epistle to the Galatians he claims perfect freedom for him-
self and the Gen tiles from the observance of the law; and
neither in it nor in the Epistle to the Corinthians does
he take any notice of the decision to which the apostles
are said to have come in their meeting at Jerusalem. And
yet the narrative of St Luke implies a different state of
affairs from that which it actually states in words ; for why
should the Jews hate St Paul so much more than the other
apostles if there was. nothing special in his attitude to-
wards them ?
We may add to this, that while St Luke gives a rather
minute acconnt of the sufferings of St Peter and the church
in Jerusalem, he has not brought prominently forward the
perils of St Paul. St Paul enumerates some of hia suffer-
ings in the second Epistle to the Corinthians (chap. xL
23-28). St Luke has omitted a great- number of thesei.
Thus, for instance, St Paul mentions that he was thrice
shipwrecked. St Luke does not notice one of these ship-
wrecks, that recorded in the Acts having taken place after
the Epistles to the Corinthians were written. Some also
t h in k that St Luke detaila several occurrences which are
scarcely ha harmony with the character of St Paul. They
say that the dismissal of John Mark, as recorded in the
Acts, is a harsh act. St Paul's remark, " I wist not that
he is the high priest" (xxiii. 5), they regard as doubtful in
point of honesty. And the way by which ho gained the
Pharisees to his side, in opposition to the Sadducees, they
describe as an expedient imworthy the character of this
fearless apostle (xxui 6).
St Luke occasionally alludes, in the Acts, to events which
took place outside of the churcL We can test hia accu-
racy in recording these events by comparing his narrative
with the narratives of historians who treat of the same
period. These historians are Josephus, Tacitus, and
Suetonius. Now, here again we find that the accounts in
the Acts generaDy agree. Indeed, Holtzmann has noticed
that all the external events mentioned in the Acts are also
to be found in Josephus. We may therefore omit Tacitus
and Suetonius, and confine ourselves to Josephus. Three
narratives deserve minute examination. The first is the
death of Herod Agrippa. Josephus says {Ant. xix. 8, 2)
that Herod was at Caesarea celebrating a festival in honour
of the Caesar. On the second day of the spectacle, the
king put on a robe made entirely of silver, "and entered the
theatre early in the day. The sun's rays fell upon the
silver, and a strong impression was produced on the people,
so that his flatterers called out that ho was a god. Ha
did not check their impiety, but soon, on looking up he
saw an owl perched above his head on a rope. Ho at
once recognised in the bird the harbinger of oviL Imme-
diately he was attacked by violent pains in the bowels, and
after five days' illness died. The Acts says that Herod
was addressing a deputation of Tyrians and Sidonbns in
Cissarea, seated on the tribunal and arrayed in a roTal
126
ACTS OF THE APOSTLES
robe. The pooplu called out, " The voice of a god, and uot
of a man." " Immediately an angel of the Lord 6tnick hiin
because he gave not God the glory, and becomiug worm-
eaten, he died"'(iiL 21-23). Both accounts agree in
representing Herod as suddenly struck with disease be-
cause he did not check the impiety of his flatterers, but
they agree in almost nothing else; and it is difficult to
conceive that the one writer knew the account of the other.
Which account is most to be trusted, depends upon the
answer given to the question which is the more credible his-
torian.
The second case relates to the Egyptian mentioned in
the question of the tribune to St Paul, in Acts xxi. 38,
" You are not then the Egyptian who, ooino time ago, made
a di.sturbanco, and led into the wilderness the four thousand
of the .sicariii" Joscphus mentions this Egj-ptian, both in
his Anliquitiea (xx. 8, 6) and in the Jewish War (iL 13, 5).
In the Jewish War (ii. 13, 3), Josephus describes the sicarii,
and then passes on, after a snort section, to the Egyptian.
He states that he collected thirty thousand people, led them
out of the wilderness " to the mount called the Mount of
Olives, which," ho 8ays.(jdw<. xx. 8, 6) in words similar to
these in Acts L 12," lies opposite to the city five furlongs
distant." On this Felix attacked him, killed some, cap-
tured others, and ' scattered the band. The Egyptian,
however, escaped with some followers. Hence the question
in the Acts. There are some striking resemblances between
the words used by both writers. The numbers differ; but
St Luke gives the numbers of the sicarii, Josephus the
num1)ers of the entire multitude led astray.
The third cr.so is the one which has attracted most
attention. In the'speech which Gamaliel delivers, in Acts
V. 35-39, it is s-.dd, " Some time before this, Theudas rose
up, saying that he was some one, to whom a number of
about four hundred men atLiched themselves, who was cut
off, and all who followed him were broken up and came to
nought. After him rose up Judas the Galilean, in the days
of the registration, and he took away people after him.;
and he also perished, and aU that followed him were scat-
tered." On turning to Josephus we fijid that both Theudas
and Judas the Galilean are mentioned. The circumstances
related of both aro the same as in the Acts, but the
dates are different. According to Josephus, Theudas
gave himself out as a prophet, in the reign of Claudius,
more than ten years after the speech of Gamaliel had been
delivered, while Judas appeared at the period of the
registration, and therefore a considerable time before
• Theudas. To explain this difficulty, some have supposed
that there may have been another Theudas not men-
tioned by Josephus, or that Josephus is wrong in his
chronology. Others suppose that St Luke made a mis-
take in regard to Theudas, and is right in regard to
Judas. Keim maintains that" St Luke has made the mis-
take, and suggests that possibly it may be based upon the
passage of Josephus; and Holtzmann has gone more
minutely into this argument. Holtzmann draws attention
to the nature of the sections of Josephus which contain the
references to Theudas and Judas {Ant. xs. 5, 1, 2). He
says that nearly all the principal statements made in these
short sections emerge somewhere in the Acts : the census
of Quirinus, the great famine, Alexander as a member of a
noble Jewish family, and Ananias as high priest. More-
over, St Luke has preserved the order of Joseph.us in men-
tioning Theudas and Judas; but Josephus says " the sons
of Judas," whereas St Luke says "Judas." "Is it not
likely," Holtzmann argues, " that St Luke had before his
mind this passage of Josephus, but forgot that it v.-as the
sons of Judas that were after Theudas, and not the father?"
He adds also, that in the short passage in the Acts there
are five peculiar expressions, identical or nearly identical
with the cxjjressions used by Josephus, and comes to th«
conclusion that St Luke knew the works of Josepnus. He
finds further traces of this knowledge in the circumstance
that, in Acts xiiL 20-21, St Luke agrees in his statements
with Josephus where both differ from the Old Testament.
He also adduces certain Greek words which he supposes
St Luke derived from his reading of Josephus. Max
Krenkel, in making an addition to this argument, tries to
show, from a comparison of passages, that St Luke had
Joscphus before his mind in the narrative of the childhood
of Christ; and ho supposes that the expedient attributed
to the apostle Paul, -of setting the Pharisees against the
Sadducees (Acts xxiiL 6), is based upon a similar narrative
given in Josephus (Sell. Jud. iL 21, 3, and Vita, 26 ff.).
The importance of this investigation is great; for if Holtz-
mann and Krenkel were to prove their point, a likelihood
would bo established that the Acta of the Apostles, or at
least a portion of it, was written after 93 A.D., the year
in which the Antiquities of Josephus was published, accord-
ing to a passage occurring in the work itself. Meanwhile,
the fact that important portions of the narrative must have
been written by an eye-witness of the events recorded,
combined with the unity of style and purpose in the book,
are cogent arguments on the other side.
The speeches in the Acts deserve special notice. The
by all historians of his age, or is he a singular exception?
The historians of his age claimed the liberty of working
up, in their own language, the speeches recorded by them.
They did not dream of verbal accuracy ; even when they
had the exact words of the speakers before them, they
preferred to mould the thoughts of the speakers into their
o\m methods of presentation. Besides this, historians do
not hesitate to give to the characters of their historj' speeches
which they never uttered. The method of direct speech is
useful in producing a vivid idea of what was supposed to
pass through the mind of the speaker, and therefore is
used continually to make the narrative lively. Now it is
generally believed that St Luke has followed the practice
of his contemporaries. There are some of his speeches
that are esddently the summaries of thoughts that passed
through the minds of individuals or of multitudes. Others
unquestionably claim to be reports of speeches really
delivered. But all these speeches have, to a large extent,
the same style as that of the narrative. They have passed
to a large extent through the writer's mind, and are given
in his words. They are, moreover, all of them the merest
abstracts. The speech of St Paul at Athens, 'as given by
St Luke, would not occupy more than a minute and a half
in deliver)-. The longest speech in the Acts, that of the
martyr Stephen, would not take more than ten miJtutes to
deliver. It is not likely that either speech lasted so short
a time. But this circumstance, while destroj-igg tLcir
verbal accuracy, does not destroy their authenticity; and
it must stiike all that, in most of the speeches, there is a
singular appropriateness, there is an exact fitting-in of
the thoughts to the character, and there are occasionally
allusions of an obscure nature, which point very clearly to
their authenticity. The one strong objection urged against
this inference, is that the speeches of St Peter and St
Paul show no doctrinal differences, such as are said to
appear in the Epistles; but the argument has no fojrce,
unless it be proved that St Paul's doctrine of justification
is different from the creed of St Peter or St James.
Not the least important of the questions which influence
critics in determining the authorship of the Acts is that of
miracles Most of those who think that miracles are im-
possible, come to the conclusion that the narratives con-
taining them are legendary, and accordingly they maintain
that the first portion of the^Acts, relating to the early
ACTS OF THE APOSTLES
iZl
churct in Jerasalem and to St Peter, is in tlie mglicst
degree untrustworthy. The writer, it is maintained, had
no personal knowledge of those early days, and received
the stories after they had gone through a long process of
transmutation. They appeal, for instance, to the account
of the Pentecost, where the miracle of ■speaking with tongues
is described. They say that it is plain, on a comparison of
the Epistle to the Corinthians with the Acts, that St Paul
meant one thing by the gift of tongues, and the writer of
the Acts another. And the inference is at hand that, if
the writer had known St Paul, he would have known what
the gift of tongues was; and the possibility of such a
mistake, it is said, implies a considerable distance from the
time of the apostles and the primitive church. They
point also to the curious parallelism between the miracles
of St Peter and those of St Paul St Peter begins his
series of miracles by healing a lame man (iii. 2); so does St
Paul (xiv. 8). St Peter exorcises evil spirits (v. 16; viii. 7);
so does St Paul (xix. 15; xvi. 18). If St Peter deals with
■the magician Simon, St Paul encounters Elymas. If St
Pet«r punishes with death (v. Iff.), St Paul punishes with
blindness (xiii. CfT.). If St Peter works miracles by his
shadow (v. 15), not less powerful are the aprons and nap-
Idns of St Paul (xix.. 12). And, finally, if St Peter can
raise Tabitlia from the dead (ix. 36), St Paul is ec^ually
successful in the case of Eutychus (xx. 9). It is easy to
see, also, that since there is no contemporary history with
■which to compare the statements in the Acts, and since
many of the statements are of a summary nature, and very
few dates are given, a critic who believes the narratives
legendary will have no difficulty in finding many elements
in the narratives confirmatory of his belief. But to those
who believe in miracles the rest of the narrative seems
plain and unvarnished. The parallelism between the
miracles of St Peter and St Paul is accounted for by the
fact that they acted in similar circumstances, and that
actual events were at hand on which to base the paral-
lelism. At the same time, some who believe in the possi-
bility of miracles think that the Acts presents peculiar
dilliculties in this matter. They say that the healing by
means of shadows and aprons is of a magical nature; that
the death of Ananias and Sapphira, and vhe other destruc-
tive miracles, are out of harmony w-ith the rest of the
miracles of the New Testament; and that the earthquakes
that release St Peter and St Paul seem purposeless. The
difficulties on this head, thoujjh real, are not however of
great importance, nor do they tell very seriously against
the received opinion that St Luke is the author of the work.
We have thus given a general summary of the questions
which come up in investigating the authorship of the Acts,
and of the arguments used in settling this point. The
conclusions based upon this evidence are very different.
Some join the traditional opinion of the church to the
modern idea of inspiration, and maintain that St Luke
was the author of the work, that every discrepancy is
merely apparent, and that every speech contains the real
and genuine words of the speaker. Others maintain that
St Luke is the writer, and that the book is justly placed
in the canon; that the narrative is, on the whole, thoroughly
trustworthy, and that neither its canonicity nor credibility
is affected by the existence of real discrepancies in the
narrative. Others hold that St Luke is the author, but
that we have got in the book an ordinary narrative, with
Jiortions credible and portions incredible; that for the
early portions of the work he had to trust mainly to his
memory, duUed by distance from the scene of action and
by lapse of time, and that he has given what he know
with the uncritical indilTerence to minute accuracy in time,
circumstance, and word, which characterises all his con-
temporaries. Others maintain that St Luke is the author,
but that, being a crcdiuous and unscientific Christian, le
recorded indeed in honesty all that he knew, but that ho
was deluded in his belief of miracles, and is often inacr\i-
rate in his statement of facts. Others think that St Ltiko
was not the author of the work. He may have been the
original author of the diary of the Apostlo Paul's travels
in which the "we" occurs; but the author of the Acts
did ngt write the diary, but inserted it into his narraUve
after altering it for a special purpose, and the narrative
was written long after St Paul and St Luke were dead.
Others think that in the Acts we have the work of Timothy
or of Sdas, or of some one else. A considerable nmubcr
imagine that St Luke had difi'erent written documents
before him while composing, and a very few think that tuo
work is the work of more than one writer. Lut as we
have intimated, tlio weight of testimony is in favour of St
Luke's authorship.
Purpose. — AVe have seen that the Acts of the Apostles
is the work of one author possessed of no inconsiderable
skill This author evidently omits many things tliat he
knew; he gives a short account of others of which he
could have supplied accurate details, and, as in tie case of
St Paul, he has brought forward one side of the character
prominently, and thrown the other into the shade. What
motive could have led him to act thus ! AVliat object had
he in inserting what ie has inserted, and omitting what ho
has omitted 1 Most of the aViswers given to these questions
have no important bearing on the question of the author-
ship of the Acts. Cut the case is different vdth the answer
of the Tubingen school. The Tubingen school maintains
that St Paul taught that the law was of uo avail to Jew
and Gentile, and that, therefore, the observance of it was
unpecessaiy ; that St Peter and the other apostles taught
that the observance of the law was necessary, and that
they separated from St Paul on this point ; and that the
early Christians were divided into two great classes — those
who held with St Paul, or the Gentile Christians, and
those who held with St Peter, or the Jewish Christians.
They further maintain that there prevailed a violent con-
troversy between these two parties in the church, until 'a
fusion took place towards the middle of the second half of
the second century, and the Catholic Church arose. At what
stage of this controversy was the Acts written 1 is the ques-
tion they put. St Peter, we have seen, is represented in
the Acts as opening the church to the Gentiles. St Peter
and the rest of the apostles at Jerusalem admit the
Gentiles on certain gentle conditions of refraining from
things offered to idols, from animals suffocated, from blood,
and from fornication. What could be the object of ^snch
statements but to convince the Jewish Christians that
they were wrong in pertinaciously adhering to their entii'e
exclusion of the Gentiles, or insisting on their observance
of the entire law 1 But St Paul is represented as observ-
ing the law, as sent forth by St Peter and the other
apostles, as going continually to the Jews first, and as
appearing in the temple and ccming up with collections
for the Jerusalem church. Was not this .also intended to
reconcile the Jewish Christians to St Paul! Then the
great doctrines of St Paul all but vanish — free grace, justi-
fication by faith alone, redemption through the blood of
Christ, — all thatischaracteristicof St Paul disappears, except
his universalism, and that is modified by the decree of the
apostles, the circumcision of Timothy, and St Paul's observ-
ance of the law. The object of all this, they affirm, must be
to reconcile the Jewish jiarty by concessions. But there is
said to be also another object, of minor importance judeed,
but still quite evident and falling in with the other.
Throughout the Acts St Paul is often accused of turning
the world upside down and causing disturbances. The
Jewish Christians may Lave thought that St Paul was to
128
A C T — A C T
blame in this matter, and tliat St Paul's opinions were
peculiarly calculated to stir up persecution against the
Cliristians. The stories in the Acts were devised to con-
vince them that they were mistaken in this supposition.
On every occasion in which St I'aid is accused before
magistrates, and especially Roman magistrates, he is ac-
quitted. Gallio, the town-clerk of Ephesus, Lysias, Felix,
and Fcstus, all declare that St Paul has done nothing con-
trary to the law. And while the Romans thus free him
from all blame, it is the Jews who are always accusing him.
We have here reproduced the argument of Zeller, who
has given the most thorough exposition of an opinion held
also by Baur, Schwegler, and others. The argument fads
to have effect if the assumption that Rt Paul and St Peter
differed radically is rejected. It also suffers from the cir-
cumstance, that there is no historical authentication of the
church bein^ in such a state in the first half of the second
century, that this attempt at reconcUiation could take
place within it. Moreover, the writing of a fictitious
production seems an extraordinary means for any one to
employ in order to effect reconciliation, especially if, as
Zeller imagines, the church in Rome was specially con-
templated. The church in Rome and the other Christian
churches had St Paul's Epistles to the Romans, Corinthians,
and Galatians before them. They could bo in no doubt as
to what were his sentiments. They must also have had
some history of his career ; artd no object coiUd be effected
by attempting to palm upon them a decree of apostles
which never e.\isted, or a hisloiy of St Peter and St Paid
contradicted by what they knew of both.
Overbeck, finding this solution of Zeller unsatisfactory,
thinks that the object of the Acts is to help the GentUe-
rhristian Church of the first half of the second century, now
I ' removed from Paulinism and strongly influenced by
J uilaism, to form a clear idea of its own past, especially of
its own origiu and of its founder St Paul. It is thus, he
maintains, an historical novel, somewhat like the Clemen-
tines, devised to realise the state of the church at an earlier
period.
It would be tedious to enumerate all the other objects
which have been set forth as the special aim of the Acts.
Some think that it was a work written for the private use of
Theophilus, and aimed, therefore, at giving huu the special
information which he required. Others think that it is
intended to describe the spread of the gospel from
Jerusalem to Rome. Others believe that the writer wished
to defend the character of the Apostle Paul Some of the
more recent members of the Tiibingen school think that
it was intended to distort the charccter of St Paul, and
that the image of him given in the Acts is an intermediate
stage between the real Paul and the caricature supposed
by them to be made of him under the name of Simon in
tlio Clementines.
Date. — There are no sure data for determining the date.
Appeal used to bo made to Acts viiL 2C, " Unto the way
which goeth down from Jerusalem to Gaza, which is
desert." But most probably it is the way which is here
said to be desert or lonely. But even if the word " desert "
or " lonely " be applied to Gaza, we get nothing out of it.
Accordingly, in the absence of data very various dates
have been assigned. Some think that it was written at
the time mentioned in the last chapter of Acts, when St
Paul had been two years in Rome. Some t hin I.- that it
must have been written after the fall of Jerusalem, as they
believe that the gospel was written after that event,
lren:eu3 thought that it was written after the death of St
Peter and St Paul (H. iiL 1). Others think that St Luke
must have written it at a late period of his life, about the
year 80 a.d. The Tubingen school thiidc that it was writ-
ten..some time in the second century, most of them agree-
125 A.D. They argue that a late date is proved by the
nature of the purpose which occasioned the work, by the
representation which it gives of the relation of the Christiana
to the Roman state, and by the traces of Gnosticism (xx.
29), and of a hierarchical constitution of the church
(i. 17, 20; viiL U, ff. ; xv. 28; xx. 17, 28) to be found
in the Acts,
, Plaee. — There is no satisfactory evidence by which to
settle the place of composition. Later fathers of the
church and the subscriptions of late MSS, mention Achaia,
Attica, Alexandria, Macedonia, and Rome. And these
places have all had their supporters in modem times.
Some have also tried to show that it was written in Asia
Jlinor, probably at Ephesus. The most likely supposition
is that it was written at Rome ; Zeller has argued with
great plausibility for this conclusion.
but the most important treatises are those of Schwanbeck,
Schneckenburger, Lekebusch, Zeller, Trip, KJostermaun,
and CErteL Zeller's work deserves special praise for ita
thoroughness. Various other writers have discussed the sub-
ject in works dealing \vith this among others; as Baur in his
Paulus; Schwegler in his NachaposlolUches Zeilalter ; Ewald
in Ids History of Israel ; Renan in his Apostles; Hausrath
in his New Testament Ilisloiy; and, in a more conservative
manner, Neander, Baumgarten, Lechler, Thiersch, and
Lange. Of commentaries, the best on the Tiibingen side
is that of De Wette, remodelled by Overbeck, and that of
the more conservative Meyer is especially good. In English
we have an able treatment of the subject in Dr Davidson's
Introduction to tite Study of the New Testament; we have com-
mentaries by Biscoe, Humphry, Hackett, Cook, Words-
worth, Alford, and.Gloag; and dissertations by Paley,
Lirks, Lewin, Conybeare, and Howson,
There are various other treatises claiming to be Acts
of Apostles. One or two of these must have existed at an
early date, though, no doubt, they have since received
large interpolations. But most of them belong to a late
period, and all of them are acknowledged to be apocryphal
They are edited by Tischendorf in his Acta Apostolorum
Apocrypha (Lipsia;, 1851), and have been translated, ■with
an introduction giving information as to their origin and
dates, by Mr Walker, in voL xvi. of tjie Anle-Nicent
Lib-rary. (j, r. )
ACTA COXSISTORII, the edicts of the consistory or
council of state of the Roman emperors. These edicts were
generally expressed in such terms as these: "The august
emperors, Di^letian and Maximian, in council declare, That
the children of decurions shall not be exposed to wild beasts
in the amphitheatre." — The senate and soldiers often swore,
either through flattery or on compulsion, upon the edicts
of the emperor. The name of a senator was erased by
Nero out of the register, because he refused to swear upon
the edicts of Augustus.
ACTA DIURXA, called &\so Acta Populi, Acta PuUica,
and simply Acta or Diuma, was a sort of Roman gizettc,
containing an authorised narrative of the transactions worthy
of notice which happened at Rome — as assemblies, edicts
of the magistrates, triiils, executions, buildings, births,
marriages, deaths, accidents, prodigies, ic. Petronius has
given us an imitation specimen of the Acta Diuma, one or
two extracts from which may be made to show their style
and contents. The book-keeper of Trimalchio pretends to
read from the Ada Vrhis: — " On the 30th of July, on the
Cuman farm, belonging to Trimalchio, were bom 30 boys
and 40 girls ; there were brought into the bam from
the threshing-floor 125,000 bushels of wheat; 500 oxen
were broken in, — On the same day the slave Mithridates
was crucified for having slandered the tutelar deity of onr
A C T — A C T
129
fi'ioiul Gaius. — On the same day 100,000 sesterces, that
could not be invested, were put into the money-box. — On
the sanio day a tire broke out in the gardens of Pompey,
which arose in the steward's house," ifcc. The Acta drflered
from the Annals (which were discontinued ia B.C. 133) in
this respect, among others, that only the greater and more
important matters were given in the latter, while in the
former things of less note also v,-ere recorded. The origin of
the Acta is attributed to Julius Caesar, who first ordered the
keeping and publishing of the acts of the people by public
officers. Some trace them back as far as Servius Tullius,
who it was believed ordered that the next of kin, on occa-
sion of a birth, should register the event in the temple of
Venus, and on occasion of a death, should register it in
the temple of Libitina. The Acta were drawn up from day
to day, and exposed in a public place to be read or copied
by all who chose to do so. After remaining there for a
reasonable time they were taken down and preserved with
other public documents.
ACTA SENATUS, among the Romans, were minutes
of the discussions and decisions of the senate. These were
also called Commentarii Senattis, and, by a Greek name,
vjTo/inj/iaTa. Before the consulship of Julius Caesar,
minutes of the proceedings of the senate were written and
occasionally published, but unofficially. Cjesar first
ordered the minutes to be recorded and published autho-
ritatively. The keeping of them was continued by
Augustus, but the publication was forbidden. Some pro-
minent senator was usually chosan to draw up these Acta.
ACTION, in Fabulous History, son of Aristaeus and
Autonoe, a famous hunter. He was torn to pieces by his
own dogs. Various accounts are given of this occurrence;
but the best known story is that told by Ovid, who re-
presents him as accidentally seeing Diana as she was
bathing, when she changed him into a stag, and he was
pursued and killed by his dogs.
ACTIAN GAMES, in Roman Antiquity, solemn games
instituted by Augustus, in memory of his victory over
Antony at Actium. See Actium.
ACTINIA, a genus of ccelenterate animals, of which the
sea-anemone is the type. See Actinozoa.
ACTINISM (from dxn's, a ray), that property of the
solar rays whereby they produce chemical effects, as in
photography. The actinic force is greatest in the blue and
violet rays of the spectrum.
ACTINOMETER (measurer of solar rays), a thermo-
meter with a large bulb, filled with a dark-blue fluid, and
enclosed in a box, the sides of which are blackened, arid
the whole covered with a thick plate of glass. It was the
invention of the late Sir John Herschel, and .was first
described in the Edinhurnh Journal of Science for 1825.
It is used for measuring the heating power of the sun's
rays, the amount of which is ascertained by exposing the
bulb for equal intervals of time in sunshine and shade
alternately.
ACTINOZOA, a group of animals, of which the most
familiar examples are the sea-anemones and " coral insects"
of the older ^vriter8. The term was first employed by
de BlainvUle, to denote a division of the Animal Kingdom
having somewhat different limits from that to which its
application is restricted in the present article : in which it
is applied to one of the two great divisions of the C(ELEN-
TERATA, the other being the Ilydrozoa.
The Actinozoa agree ^vith the Hydrozoa in the primitive
and fundamental constitution of the body of two membranes,
an ectoderm and an endoderm, — between which a middle
layer or mesoderm may subsequently arise. — in the absence
of a completely differentiated alimentary canal, and in
possessing thread cells, or nematocysts; but they present a
Bomewhat greater complexity of structure.
1—6
This is manifest, in the first place, m their visceral tuba,
or " stomach," as it is often called, which i» continued from
the margins of the mouth, for a certain distance, into the
interior cavity of the body, but which is always open at its
fundus into that cavity. And, secondly, in the position of
the reproductive elements, which, in the Bydrozna, are
always developed in parts of the body wall which are in
immediate relation with the e-xternal surface, and generally
form outward projections; while, in the yldi'aozoa, they are
as constantly situated in the Literal walls of the chambers
into which the body cavity is divided. In consequence of
this arrangement, the ova, or sexually generated erabrj-os,
of the Actinozoa are detached into the interior of the body,
and usually escape from it by the oral aperture; while those
of the Uydrozoa are at once set free on the exterior surface
of that part of the body in which they are formed.
The Actinozoa comprise two groups, which are very
dif5'erent in general appearance and habit, though really
similar in fundamental structure. These are —
1. The Coralligena or sea-anemones, coral animals, and
sea-pens; and 2. The Clenoiphora.
(1.) The Coralligena. — A common sea-anemone presents
a subcylindrical body, ' terminated at each end by a disk.
The one of these discoidal ends serves to attach, the
ordinarily sedentary animal ; the other exhibits in the
centre a mouth, which is usually elongated in one direction,
and, at each end, presents folds extending down into the
gastric cavity. This circumstance greatly diminishes the
otherwise generally radial symmetry of the disk, and of the
series of flexible conicfJ tentacles which start from it;
and, taken together with some other circumstances, raises
a doubt whether even these animals are not rather bilater-
ally, than radially, symmetrical Each tentacle ia hoUow,
and its base communicates with one of the chambers
into which the cavity of the body is divided, by thin
membranous lamellae, the so-called mesenteries, which
radiate from the oral di.sk and the lateral walls of the
body to the parietes of the visceral tube. The inferior
edges of the mesenteries are free, and arcuated in such
a manner as to leave a central common chamber, into
the circumference of which all the intermesenteric spaces
open, while above, it communicates v/ith the visceral
tube. The tentacles may be perforated at their extremi-
ties, and, in some cases, the body wall itself exhibits aper-
tures leading into the intermesenteric spaces. The free edges
of the mesenteries present thickenings, like the hem of a
piece of linen, each of which is much longer than the distance
between the gastric and the parietal attachment of the
mesentery, and hence is much folded on itself. It is lull
of thread cells. The mesoderm, or middle layer of th i
body, which lies between the ectoderm and the endoderm,
consists of a fibrdlated connective tissue, containing fusi-
form or stellate nucleated cells, and po.ssesses longitudinal and
circular muscular fibres. The.^c are prolonged into the mesen-
teries, and attain a great development in the disk of attach-
ment, which serves as a sort of foot like that of a limpet.
The question whether the Coralligena possess a nervous
system and organs of sense, hardly admits of a definite
answer at present. It is only in the Aclinidco that the
existence of such organs has been asserted ; and the nervous
circlet of Actinia, described by Spix, has been seen by no
later investigator, and may be safely assumed to bo non-
existent. But Professor P. M. Duncan, F.R.S., in a paper
" On the Nervous Sysjtem of Actinia," recently communi-
cated to the Royal Society, has aflirmcd the existence of a
nervous apparatus, consisting of fusiform ganglionic cells,
united by nerve fibres, which resemble the sympathctio
nerve fibiils of the Verlclraia, and for'in a plexus, which
appears to extend throughout the pcd.-il disk, and very
probably into other parts of the body. In soino of
I. — I-
130
ACTINOZOA
llio Adinidce (e.y,, Actinia mfsemhryanthemum), brigbtlj
coloured bead-liko bodies arc situated on tho oral diik out-
side the tentacles. Tho structure of these " ehromato-
])lioro3," or " boursos calicinalos," has been carotully investi-
gated by Schneider and Kottckem, and by Professor
Duncan, They are diverticula of the body ■nail, tho sur-
face of •which is composed of close-sot "bacilli," beneath
which lies a layer of strongly-refracting spherules, followed
by onother layer of no less strongly refracting cones. Sub-
jacent to theso Professor Duncan finds ganglicra cells and
nerve plesusos. It would Bcom, therefore, that these bodies
are rudimentary eyes.
At tho breeding scasoa tho ova or Bpennatozoa are
evolved in tho thickness of tho raesontc-ries, and are dis-
charged into tho intennosouteric spaces, the ova undergo-
ing their development within the body of the parent. Tho
yolk, usually, if not always, enclosed in a vitelline membrane,
undergoes complete division, and tho outer wall of tho
ciliated blastodermic mass which results becomes invagi-
natcd, tho embryo being thereby converted into a double
wailed sac — the external aperture of which is the future
mouth, while the contained cavity represents the bodycavity.
In this stage the larval Actinia represents the Gaetrula con-
dition of sponges and Ilgdrozoa. Tho edges of the oral
aperture grow inwards, giving rise tp a circular fold, which
is the rudiment of tho visceral tube. This is at first con-
nected with thuJiody wall by only two mesenteries, wliich are
seated at opposite ends of one of tho transverse diameters of
the body. As the mesenteries increase in number, the ten-
tacles grow out as diverticula of the intermesenteric spaces.
In all the Coralligsna, the development of which has
been observed, the embryo is converted into a simple
actinozoon in a similar manner; but from tliis point they
diverge in two directions. In one great group, the mesen-
teries, and the tentacles which arise from tho intermesen-
teric chambers, increase in number to sis; and then, in the
great majority of cases, the iiitermcsenteric spaces undergo
subdivision by the development of new mesenteries, accord-
ing to curious and somewhat cpmplicat'ed numerical laws,
nntU their number is increased to some multiple of five
or six. In these Hexacoralla (as they have been termed
by Haeckel) the tentacles also usually remain rounded and
conicaL In the other group, the Octocoralla, the mesen-
teries and the tentacles increase to eight, but do not sur-
pass that number; and the tentacles become flattened and
seprated at the edges, or take on a more or less pennatifid
character.
There are no Octocoralla which retain the simple indivi-
duality of the young actinozoon throughout Ufe ; but all in-
creas") by gemmation, and give rise to compound organisms,
■which may be arborescent, and fixed by the root end of the
(/ommon, stem, as in the Alcyonidce and Gorgonidce-; or may
possess a central stem which is not fixed, and gives ofi'
lateral branches which undergo comparatively little sub-
division, as in the Pennatulidce.
Tho body cavities of the zoSids of these compound
Octocoralla are in free commimication ■with a set of canals
which ramify through the ccencsarc, or common fabric of
the stem and branches by which they are borne, and which
play the part of a vascular system.
Except in the case of Tubipora, the zooids and the super-
ficial coiuosarc give rise to no continuous skeleton ; but the
deep or inner substance of the coenosarc may be converted
into a splid rod-like or branching stem.
In the Hexacoralla, on the other hanrd, one large
group, that of the Actinidce, consists entirely of simple
organisms,— jorganisms that is, in which the primitive
actinozoon attains its adult condition without budding or
fissioa; or if it bud or divide, the products of the operation
•ej)arate from one another. No true skeleton is formed-
all are to some extent locomotive, and some (J/inyos) float
freely by the I.eli of thjir contractile pedal region. The
most remarkable form of this group is the genus Cereanthut,
which has two circlets, each composed of numerous tentacles,
one immediately around the oral aperture, the other at
tho margin of tho disL Tho foot is elongated, subconical,
and generally presents a pore at its apex. Of the diametral
folds of the oral aperture, one pair is much longer than the
other, and is produced as far as the pedal poro. The larva
18 curiously Cko a voung hydrozoon with free tentacles,
and at first possesses four mesenteries, ■nheoce it may be
doubted whether CereatUkut docs not rather belong to the
Octocoralla.
Tho ZoanlhidoB differ from tho Actinidm in little more
than thoir multiplication by buds, ■which remain adherent,
either by a common connecting mass or coenosarc or by
stolons; and in tho possession of a rudimentary, Bpicuki
skeleton. .
On tho other hand, the proper stone-corals (aa contra-
distinguished from tho red coral) are essentially ActinicB,
which become converted into compound organisms by
gemmation or fission, and develope a continuous skeleton.
Tho skelfetal parts' of the Aclinozoa, to which reference
has been made, consist^ either of a substance of a homy
character; or of an organic basis impregnated with earthy
salts (chiefly of lime and magnesia), but which can be
isolated by the action of dUuto acids; or finally, of cal-
careous salts in an almost crystalline state, forming rods
or corpuscles, which, when treated with acids, leave only
an inapprecL'ible and structureless film of organic matter.
The hard parts of all the Aporosa, Perforata, and Tabu-
lata of Milne Edwards are in the last-mentioned condition;
while, in the Octocoralla (except Tubipora) the Antipalhida,
and Zoantkidd, the skeleton is either homy, or consists, at
any rate, to begin with, of definitely formed spicula, wliich
contain an organic basis, and frequently present a laminated
structure. In the organ coral (Tubipora), however, the
skeleton has the character of that of the ordinary stono-
corals, except that it is perforated by numerous minute
canals.
The skeleton appears, in all cases, to be deposited within
the mesoderm, and in the intercellular substance of that
layer of the body. Even the definitely shaped spicula of
the Octocoralla are not the result of the metamoi^osis
of cells. In the simple aporose .corals the calcification
of the base and side'walls of the body gives rise to
the cup or theca; from this the calcification radiates in-
wards, in correspondence with the mesenteries, and gives
rise to as many vertical septa, the spaces between which
are termed IccuH; while, in the centre, either by union of
tho septa or independently, a pillar, the columella, grows
up. From the sides of adjacent septa scattered processes
of calcified substance, or synapticulce, may grow out
toward one another, as in the Funffidw; or the Loterrup-
tion of the cavities of the loculi may be more complete by
the formation of shelves stretching from septum to
septum, but lying at difi'erent heights in adjacent locuh.
These are interseptal disrepiments. Finally, in the Tabutata,
horizontal plates, which stretch completely across the cavity
of the theca, are formed one above the other and constitute
tabular diiaepimentt.
In the Aporosa the theca and eepta are almost invariably
imperforate ; but in the Perforata they present apertures,
and in some madrepores the whole skeleton is reduced
to a mere network of dense calcareous substance. When
the Hexacoralla multiply by gemmation or fission, and
thus give rise to compound massive or dborescent aggre-
gations, each newly-formed coral polvpe developes a skeleton
* See Eiflliker's /conu Bulotcgiar, 186S.
ACTINOZOA
131
of it3 own, which ia either confluent with that of the
others, or ia united with them by calcification of the con-
necting substance of the common body. Thia intermediate
skeletal layer is then termed ccenenchyma.
The Octocoralla (excepting Tubipm-a) give rise to no tkecce
and their dependencies, the skeleton of each polype, 'and
of the superficial portion of the polyparium, being always
composed of loose and independent spicula. But in many,
aa the Gorgonidoe, Pennatulidw (and in the AntipathidcB
among the Uexacordlla), the central part of the common
stem of the compound organism becomes hardened, either
by conversion into a mere horny axis (which may be more
or less impregnated with calcareous salts) without spicula;
or the cornification may be accompanied by a massive
development of spicula, either continuously or at intervals ;
or the mam feature of the skeleton may, from the first, be
the development of spicula, which become soldered together
by a subcrystaUine intermediate deposit, as in the fed
coral of commerce {Corallium rubrum).
Tt has seemed advisable to say thus much concerning the
nard parts of the Aciiiiozoa in this place, but the details
of the structure and development of the skeleton of the
Coralligena will be discussed under CoEixs and Cokai.
Reefs.
The Tabula^a, or MiUepores, and the Ritgom, an extinct
and almost exclusively Palaeozoic group of stone-coral form-
ing animals, are usually referred to the Coralligena. Judg-
ing by the figures given by Agassiz^ of living MiUepores, the
polypes which cover its surface are undoubtedly mnch more
similar to coryinform Hydrozoa than they are to any
Actincioon. But it is to be observed, firstly, that we have
no sufficient knowledge of the intimate structure- of the
polypes thus figured; and, secondly, that the figures show
not the least indication of the external reproductive organs
which are so conspicuous in the Hydrozoa, and which
surely must have been present in some one or other of the
MiUepores examined, were they really Hydrozoa. As re-
gards the Rugooa, the presence of septa is a strong
argument against their belonging to any group but the
Actinozoa, though it is not to be forgotten that a tendency
to the development of septiform prominence is visible in
the walls of the gastric passages of certain calcareous
sponges.
Phenomena analogous to the "alternation of generations,'*
which is 80 common -among the Hydrozoa, are. unknown
among the great majority of the Actinozoa. But Semper-
has resently described a process of sexual multiplication
in two species of Fungiae, which he ranks under this head.
The Fungice bud out from a branched stem, and then
become detached and free, as is the habit of the genus;
To make the parallel with the production of a Medusa
from a Soyphistojyia complete, however, the stem should bo
nourished by an asexual polype of a different character from
the fornw of Fungice which are produced bj gemmation.
And this does not appear to be the case.
Dimorphism has been observed by KoUiker to occur
extensively among the Pennatulidce. Each polypary pre-
sents at least two different sets of zoiiids, some being
fully developed, and provided with sexual organs, while
the others have neither tentacles nor generative organs, and
exhibit' some other peculiarities.' These abortive zoiiids
are either scattered . irregularly among the others {e.g.,
Sarcophyton, Verelilluni), or may occupy a definite position
'e.^. , Virgularia).
(2.) The Ctenophora. — These are all freely swimming,
' CoTiiribtitlons to the Natural History of the United States. Vol.
iii. Pl.ito XV.
' Ueber Oentrntions-XVechsel hei SteinkoratUn. teipiig, 1872.
• Abhandlunfjen der SeT^henbergischen .Vutitr/orschfnJen Oaelt-
tr.\<t/tj bd. viL vUi. .- | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5096462368965149, "perplexity": 14798.817639496901}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-30/segments/1500549424721.74/warc/CC-MAIN-20170724042246-20170724062246-00046.warc.gz"} |
https://developer.softbankrobotics.com/nao6/naoqi-developer-guide/choregraphe-suite/main-objects/box-inputs/outputs | # Box - Inputs/outputs ¶
## Input of a box ¶
They are several natures of inputs. Some are only accessible from the inside of the box (from its diagram or its Timeline ), some only from outside (from the parent diagram) and some from both.
To activate those which are available from the outside of the box, you have to connect them to either the main input of the diagram, or the output of a box.
The others are automatically activated when a special event is raised.
The picture displayed on an input depends on its nature :
Nature of the inputs
On the box
Within the
box diagram
Nature Description
onStart When this input is stimulated, the box is started .
onStop
When this input is stimulated, the box is stopped .
This input is only visible outside the box (not within the diagram of the box) as it automatically stops everything within the diagram.
onEvent
This input has no specific effect on the box, it does not start nor stop it. When it is stimulated:
1. The onInput_<input_name> function of the box script is called.
2. The signal received on the input is transmitted to the diagram of the box. Note though that the signal will only be transmitted to the diagram if this diagram is already loaded .
ALMemory Input
This special type of input is only visible within the diagram. So you cannot stimulate it from the outside of the box.
It is stimulated every time the value of the data stored in ALMemory corresponding to this input is updated and an event is raised to tell that it has been updated. Note that these inputs are only active when the diagram is loaded .
To have an example of use of this type of input, see the tutorial Creating a box to retrieve right bumper value using ALMemory .
This type of input is only visible within the diagram and when the box is a Timeline.
So you cannot stimulate it from the outside of the box. It is only stimulated when the box diagram has been loaded .
Note
All these special natures of inputs have no special effect on a script box as it has no flow diagram nor Timeline . For those accessible from the outside of the box, the onInput_<input_name> function of the box script is just called.
## Output of a box ¶
They are several natures of outputs.
You can stimulate them either from the diagram or the Timeline or the script of the box.
To stimulate it from the diagram or the Timeline of the box, you need to connect it to a sub-box output.
To stimulate it from the script of the box, you need to call its corresponding method. For more information about this corresponding method, see the section: Built-in functions in the script of a box .
The picture displayed on an output depends on its nature :
Nature of the outputs
On the box
Within the
box diagram
Nature Description
onStopped
• Diagram or Timeline box: When this output is stimulated from the diagram, the box is stopped .
• Dialog box: When this output is stimulated from the diagram or the QiChat script, the dialog topic is deactivated.
• Python box: This output has no specific effect, it does not stop the box.
punctual
This output has no specific effect on the box, it does not start nor stop it.
When it is stimulated, the signal received on the output is transmitted to the parent diagram .
## Type of I/O (input/output) ¶
The communication between boxes is event based , so a simple event signal can be sent from one box to another. But the signal can also carry information (such as a string, a number, an array...).
Then an important thing you need to know about I/O is that the color of an I/O depends on the type of the data it carries.
Here is a table gathering all types of I/O with their corresponding color:
Type of I/O
Input Output Type Description
Bang Represents a simple event . This type of I/O does not carry any data with it, only the information that it is stimulated.
Number Represents an event carrying a data . This data is either a number (float or int) or an array of numbers.
String Represents an event carrying a data . This data is either a string or an array of strings.
Dynamic Represents either a simple event (as the Bang type) or an event carrying a data . This data (if any) is either a number (float or int), a string or an array of numbers, strings and arrays.
Depending on their type, it is not always possible to connect two I/O : the information the output sends has to be understandable by the input.
Note
You can connect any type of I/O to a Bang input. The data sent will then be lost and will only be understood as a simple event .
## Input, and output edition widgets ¶
When you create or edit an box input , the following widget is displayed:
You can here set:
• the name of the input.
• the brief description of what is done when this input is stimulated in the field Tooltip .
Note
This description will appear in a tooltip displayed by passing above the input in the flow diagram.
• the type of data expected by this input in the field Type : Dynamic, “Bang”, Number or String. For further details about these types, see the section: Type of I/O (input/output) .
You can also choose the nature of the input: onEvent, onStart, onStop or ALMemory Input. For more information about these natures, see the section: Input of a box .
If the input is an ALMemory input, you will be able to choose which value from ALMemory the input will be connected to.
Note
You need to be connected to a robot if you want to browse the list of available values.
When you create or edit an box output , you get a very similar widget:
But you have no field ALMemory Value name and the available nature of outputs are different: onStopped or punctual. For more information about these natures, see the section: Output of a box . | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.3345964848995209, "perplexity": 1280.4121690650566}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-40/segments/1600400189264.5/warc/CC-MAIN-20200918221856-20200919011856-00700.warc.gz"} |
https://www.edaboard.com/threads/cst-macro-vba-for-transform-a-brick.385448/ | # CST macro VBA for transform a brick
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Hello every body.
I have a problem in CST macro VBA.
I have 10 component in CST studio with name : component1, component2, component3,.....component10, and in each one of this ten component, I have 10 brick with name: c_1 , c_2 , c_3,........c_10.
Now i want to transform(rotate) each brick by a simple function, i write it in macro vba, similar to the one below and i cant do it, can you help me, where is my mistake?
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Sub Main
Dim m, l As Integer
For m=0 To 9
For l=0 To 9
With Transform
.Reset
.Name(c_& l)
.component(Component & m)
.Origin "Free"
.Center "0.5+m", "0.5+l", "0"
.Angle "0", "0", "20*l"
.MultipleObjects "False"
.GroupObjects "False"
.Repetitions "1"
.MultipleSelection "False"
.Transform "Shape", "Rotate"
End With
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11K | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9394547939300537, "perplexity": 19583.305377414556}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-29/segments/1593655896905.46/warc/CC-MAIN-20200708062424-20200708092424-00320.warc.gz"} |
https://gamedev.stackexchange.com/questions/96453/moving-obb-vs-triangle-intersection-test | Moving OBB vs. triangle intersection test
Requirements: to write a test function that, given a moving OBB (oriented bounding box) and a triangle, returns true whenever the OBB hits the triangle.
The OBB is described by its half extents (h1, h2, h3), principal axes (a1, a2, a3) and center point C(cx,cy,cz). The triangle is described by its three vertices (U1, U2, U3). The OBB moves with the velocity V over a period of time of 1 second (hence V is also the displacement the OBB undergoes).
Question: I have already read Dave Eberly's mini-paper on the matter and made an attempt at an implementation. Also related to this paper, I have a question regarding the w projection of the W velocity: - is w equal to dot(W, L), where L is one of the 13 possible separating axes he considered in that paper?
An oriented bounding box is delimited by six planes (one for each face). A triangle is also delimited by three lines (one for each sides). A naive implementation (which often a good idea to start with) is thus to compute the intersection of any triangle edge with any plane and to check whether at least one intersection occur within an edge of a triangle and within a face of the OOB.
for each edge E of the triangle,
let L be the line of direction obtained by extending E
for each face F of the OOB,
let P be the plane obtained by extending F.
let q be the intersection of L and P.
if q exists and q is within E and q is within F, then
An intersection occurred.
It's probably easier to use a local reference frame so the OBB becomes an AABB. Then you can start to optimize.
• I appreciate your description of a potential solution. However, I am considering a slightly more complicated situation where the OBB is moving (a so-called shape-cast) and the triangle is stationary. What I would like point out is that the plane-triangle intersection leads to too many false positives, besides working only for stationary objects. – teodron Mar 11 '15 at 16:38
• If your bounding box is used for pruning, you need simple computation, or else you defeat the purpose of pruning. An easy solution is to expand/find an OOB so that they enclose both the box at the beginning and the end of the time slice. (I usually use AABB and it's even easier). – Lærne Mar 13 '15 at 0:26
• If you want exact mathematical solutions, you can also use a reference frame following the box position and orientation. That way, you transform the problem with a stationary OBB which is a AABB and a moving triangle. The sweep of the moving triangle makes a prism, with possible bending and torsion if you OBB has an non-nul torque. The difficult part here is to describe the three twisted and bended "vertical edges" of the prism. Then you can do the intersection of the curves and the axis-aligned planes of the AABB. For the efficiency, I suggest to start from a working solution first. – Lærne Mar 13 '15 at 2:23
• these are quite promising suggestions.Again, there's a "however" involved: it is not at all sufficient to do the intersection of the prism's "curvy" edges with the OBB/AABB. Simply imagine a translation of a triangle that intersects the box by first hitting a corner. Or if the triangle is simply larger than the box. I do have a somewhat working solution involving Dave Eberly's suggestion, but with totally different separating axes. BTW, thanks a lot for your comments and answer, I appreciate them a lot! – teodron Mar 13 '15 at 7:11
Although not 100% accurate, in the sense that it may report intersections even when the objects do not actually collide (but for that a more complex solution like GJK could be easily used), here's the solution I came up with after reading Dave Eberly's original paper on OBB vs moving triangle intersection test.
In that paper, the intersection test is performed between a triangle, described by vertices (U0, U1, U2) and edges E0 = U1 - U0, E1 = U2 - U0, E2 = E1 - E0, and an OBB, given through its center, C, principal axes, A0, A1, A2 and half extents, ha0, ha1, ha2.
The triangle is assumed to be displaced along a direction W. The W axis, in this case, is not assumed to be normalized, but has a magnitude equal to the total displacement the triangle is subjected to.
The problem is not to find an actual intersection point, but to decide whether the OBB and triangle might overlap. For this, Eberly conceived a series of 13 separating axis tests. In summary, the separating axis test works by starting with a candidate axis, L, and checks whether the projections of the boundaries of the OBB and of the swept triangle volume (in this case, an oblique triangular prism) overlap as intervals. The origin of the L axis is assumed to be at the center C of the OBB. Refer to the picture below for a better understanding
After implementing the test in the article, I found it to perform very poorly for the case where the triangle was actually moving. In 50% of the cases, no separating axis candidate was able to separate the objects, although they were clearly not going to collide. Thus, I replaced those candidates with the following set of 7 axes, which worked reliably as an early out test in 93% of the cases:
• L = W.cross(Ei), i = 0:2
• L = W.cross(Ai), i = 0:2
• L = W
The first six cases are actually less numerically demanding due to the fact that L is by definition perpendicular to W (it helps with avoiding to compute some dot products since they're 0). In the last case, things are a bit more complicated, but that's why I left it as a last resort test before deciding the objects might indeed overlap. Although not represented in this figure, D = U0 - C is one of the vectors involved in computing the projection of the triangle onto the L axis.
To efficiently compute the amounts (cross and dot products) needed for this test, I wrote a small python script to generate the first 6 cases:
def symCross(i, j):
k = {0, 1, 2}.difference({i, j})
k = next(iter(k))
if (i == 0 and j == 1) or (i == 1 and j == 2) or (i == 2 and j == 0):
return k
else:
return -k
WcrossAi = set()
WcrossEi = set()
WcrossEidotAj = set()
WdotAi = set()
print "Real p0, p1, p2, R; \n";
# L = WxAi
for i in range(0,3):
print "// L = WcrossA%d" % (i);
L = "WcrossA" + i
if L not in WcrossAi:
print " Vector4 WcrossA"+i + "; WcrossA"+i +".setCross(W,a"+i+");"
if "WcrossE0" not in WcrossEi:
print " Vector4 WcrossE0; WcrossE0.setCross(W, E0);"
if "WcrossE1" not in WcrossEi:
print " Vector4 WcrossE1; WcrossE1.setCross(W, E1);"
if "WcrossE0dotA{0}".format(i) not in WcrossEidotAj:
WcrossEidotAj.add("WcrossE0dotA"+i);
print " Real WcrossE0dotA"+i+ " = WcrossE0.dot3(a"+i+");"
if "WcrossE1dotA{0}".format(i) not in WcrossEidotAj:
WcrossEidotAj.add("WcrossE1dotA"+i);
print " Real WcrossE1dotA"+i+ " = WcrossE1.dot3(a"+i+");"
print " p0 = WcrossA{0}.dot3(D);".format(i)
print " p1 = p0 - WcrossE0dotA{0};".format(i)
print " p2 = p0 - WcrossE1dotA{0};".format(i)
# R
R = " R = "
for k in range(0,3):
if i != k:
l = {0, 1, 2}.difference({i, k})
l = next(iter(l))
if "WdotA"+l not in WdotAi:
WdotAi.add("WdotA"+l)
print " Real WdotA"+l+" = W.dot3(a"+l+");"
R += "+ha"+k+"*fabs(WdotA"+l+") "
R += ";"
print R
#heredoc test
print '''
if (ProjectedDistanceOveralp(p0, p1, p2, R) == false)
{
return false; // no intersection
}
'''
# L = WxEi
for i in range(0,3):
print "// L = WcrossE"+i
if "WcrossE"+i not in WcrossEi:
WcrossEi.add("WcrossE"+i)
print " Vector4 WcrossE{0}; WcrossE{0}.setCross(W,E{0});".format(i)
print " p0 = WcrossE{0}.dot3(D);".format(i)
p1 = " p1 = p0"
p2 = " p2 = p0"
if i == 0:
p1 += ";"
p2 += " + WdotN;";
elif i == 1:
p1 += " - WdotN;"
p2 += ";"
else:
p1 += " - WdotN;"
p2 += " - WdotN;"
print p1
print p2
R = " R = ";
for k in range(0,3):
if "WcrossE{0}dotA{1}".format(i,k) not in WcrossEidotAj:
WcrossEidotAj.add("WcrossE{0}dotA{1}".format(i,k))
print " Real WcrossE{0}dotA{1} = WcrossE{0}.dot3(a{1});".format(i, k)
R += " + ha{1} * fabs( WcrossE{0}dotA{1} ) ".format(i,k)
R += ";"
print R
#heredoc test
print '''
if (ProjectedDistanceOveralp(p0, p1, p2, R) == false)
{
return false; // no intersection
}
'''
For testing whether the projected bodies overlap, I've written two SIMD friendly functions in c++:
bool ProjectedDistanceOveralp(Real p0, Real p1, Real p2, Real R)
{
Vector4 p012; p012.set(p0, p1, p2);
Vector4 Rplus; Rplus.setAll(R);
Vector4 Rminus; Rminus.setAll(-R);
}
bool ProjectedDistanceOveralpWithW(Real p0, Real p1, Real p2, Real R, Real w)
{
Vector4 p012; p012.set(p0, p1, p2);
Vector4 Rplus; Rplus.setAll(R);
Vector4 Rminus; Rminus.setAll(-R - w);
}
Finally, the L=W axis test can be written as:
// L = W
Real WdotW = W.dot3(W).getReal();
p0 = W.dot3(D).getReal();
p1 = p0 + W.dot3(E0).getReal();
p2 = p0 + W.dot3(E1).getReal();
R = ha0 * fabs(WdotA0) + ha1 * fabs(WdotA1) + ha2 * fabs(WdotA2);
if (ProjectedDistanceOveralpWithW(p0, p1, p2, R, WdotW) == false)
{
return false; // no intersection
} | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5783510804176331, "perplexity": 2720.0369770203156}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-10/segments/1581875145676.44/warc/CC-MAIN-20200222115524-20200222145524-00188.warc.gz"} |
http://math.stackexchange.com/questions/168023/am-i-allowed-to-realize-one-object-twice-within-one-set-theory | # Am I allowed to realize one object twice within one set-theory?
Say I consider a set theory with the Axioms of Extensionality and the Axiom of Pairing.
As I understand it, stating the axiom allows me to make a definition like
$$(a,b):=\{\{a\},\{a,b\}\}$$
and work with that $(a,b)$ in the context of my theory. Pairing says "it exists" (I can write it down with my language) and Extensionality says the abstract idea of it is unique as a set.
Is that way of thinking correct? Is that the purpose?
Because (if I know $a$ and $b$ exists and since I know what set brackets are) in a way I feel the set $\{\{a\},\{a,b\}\}$ existed already before the existence of a pair was guaranteed by the axiom - the possibility of nesting of sets as for the definition seems to be apriori to me, I asked a related question here.
Secondly, since there are more set-constructions of the ordered pair, like say
$$(a,b)':=\{b,\{a,b\}\}$$
as an alternative, I wonder:
Am I allowed to realize the ordered pair twice in one theory?
Then I could for example put ordered pairs as elements of ordered pairs of the second type and so on.
Is there really only one realization of the ordered pair in say ZFC or are there in fact all thinkable versions in the theory and we just choose one if we prove stuff about the abstract thing (which implies that the statements are true for all models)?
Or another idea: Should I view the whole thing in a way that I only define the thing using a concrete relization so that I can prove stuff about the "actual" abstract object, which is really only implicitly postulated to exist in the axiom. If that point of view ist true then I don't really see what the real difference of two realizations can be.
-
You can have many different definitions that achieve the same end, namely, an "object" that distinguishes between the "first component" and the "second component". You should not use the same notation to denote two different constructions, and most of the time you don't care what the construction actually is: you want to use its "universal property" rather than its actual construction in the proofs. Then, it doesn't matter if you and I are using the exact same definition of the object, we just care that we are using the universal property of the object. – Arturo Magidin Jul 7 '12 at 22:39
J.H. Conway complained at the end of On Numbers and Games that mathematicians were too concerned with the specific implementation of objects such as ordered pairs. I wrote some slightly more detailed comments about this, which are too long to reproduce here. – MJD Jul 8 '12 at 0:39
I think I wrote this as an answer to one of your previous questions and then I deleted it (I think Henning wrote another answer incorporating the point I was making).
We hardly make actual use of the properties of an ordered pair beyond the fact that it is actually a collection of two elements which may not be distinct and the order does matter.
Much like the proofs in real analysis do not depend on how you interpret the real numbers within a model of ZFC, but rather on the properties of the structure, a similar thing can be said here.
What we write when we write a proof is more of a schema for a proof. We consider abstract (non-pure set) objects and we say "plug the definition here, and insert the definition there". Ordered pairs make an excellent example as they appear almost everywhere. However there are only a few places where you actually care for the contents of the interpretation of the ordered pair.
Most of the time you care about the fact that an ordered pair allows you to distinguish between the two elements, even if they are the same (e.g. $\langle a,a\rangle$). As long as you have a way of telling which is the left coordinate and which is the right there is no real danger in replacing the definition.
However you should remember, again, that every time you are using an instance of the replacement axiom schema in contexts of ordered pairs then the axiom you are using may be different; but the logic behind the proof remains the same.
-
I refer to this question in my first sentence. 10k users can also read my deleted answer and the comments ensued. – Asaf Karagila Jul 7 '12 at 22:36
Okay, so if I read this correctly, you imply that one could in principle also just not make a definition like $(a,b):=\{\{a\},\{a,b\}\}$ but work everything out purely in terms of chains of already given logic language symbols. And then the axioms are only the additional inference rules I need to get from $A$ to $B$ in that derivation. – NikolajK Jul 7 '12 at 22:39
@Nick: Consider the proof with a variable, $\varphi(a,b,x)$ which says that $x$ is an ordered pair $\langle a,b\rangle$. We almost always use the properties of the ordered pair, not its realization, so we can simply write formulae that when given $\langle a,b\rangle$ return $a$ or $b$ as objects (e.g. $\varphi(u,v)$ says that $u$ is an ordered pair and $v$ is the element in the left coordinate), then the actual interpretation doesn't matter, what matters is that we have a formula defining the "model of an ordered pair" up to isomorphism. – Asaf Karagila Jul 7 '12 at 22:44
I guess that means yes? – NikolajK Jul 7 '12 at 22:56
@Nick: In a way, yes. I just wanted to make my point perhaps clearer, but I can get unclear when writing relatively long answers. – Asaf Karagila Jul 7 '12 at 22:58
You can realize ordered pair as many ways as you want, but what's the point? What matters is not how you implement the ordered pair but the fundamental property that an ordered pair ought to satisfy, namely that $(a, b) = (a', b')$ if and only if $a = a'$ and $b = b'$.
-
If you want to prove the claim $1\in\langle 0,1\rangle$ then you do care about the interpretation. – Asaf Karagila Jul 7 '12 at 22:31
Okay, but why would you ever want to do that? – Qiaochu Yuan Jul 7 '12 at 22:31
I am really bored, or I want to post on MathOverflow that ZFC is bad because it proves that $1\in\langle 0,1\rangle$ and get a lot of upvotes... :-) – Asaf Karagila Jul 7 '12 at 22:32
@Nick: The standard interpretation (or if you wish to think about von Neumann ordinals) has $1=\{\varnothing\}$ and the Kuratowski definition of $\langle 0,1\rangle$ is $\{\{0\},\{1\}\}=\{\{\varnothing\},\{\{\varnothing\}\}\}$. Note that this implies that $1=\{0\}$ and therefore $1\in\langle 0,x\rangle$ for all $x$. In fact $\{1\}=\langle 0,0\rangle$! – Asaf Karagila Jul 7 '12 at 22:48
@AsafKaragila: That's really awesome! (Doesn't the Kuratowski definition contain a set with two elements, i.e. is there a $0$ missing next to the $1$ in the $\{\{0\},\{1\}\}$-expression?) – NikolajK Jul 7 '12 at 22:54 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9051325917243958, "perplexity": 240.43513380759225}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-18/segments/1430459200931.63/warc/CC-MAIN-20150501054640-00069-ip-10-235-10-82.ec2.internal.warc.gz"} |
http://mslc.ctf.su/wp/hack-lu-2010-ctf-challenge-10-writeup/ | Oct
30
## Hack.lu 2010 CTF Challenge #10 Writeup
#10 – Chip Forensic
To solve this task we have something like this (original image is lost)
and hex string:
0B 12 0F 0F 1C 4A 4C 0D 4D 15 12 0A 08 15.
What we see on image? Some USB device. Those who have seen them on ebay or on other sites knows that it is USB-keylogger. If you see them for first time use image search(e.x. tineye.com) or just guess.
Well, now we know it is keylogger. So hex string might be a log of USB-keyboard protocol. But organizators have simplified this task(. They put in hex string only scan-codes without synchronization signals. So just use table of USB-keyboard scan-codes.
0B 12 0F 0F 1C 4A 4C 0D 4D 15 12 0A 08 15 H O L L Y Home Delete J End R O G E R
So “JOLLYROGER” was typed. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8625147342681885, "perplexity": 5505.516930144819}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-50/segments/1606141195745.90/warc/CC-MAIN-20201128184858-20201128214858-00539.warc.gz"} |
https://www.physicsforums.com/threads/differential-forms-and-wedge-products-are-giving-me-trouble.636443/ | # Differential forms and wedge products are giving me trouble.
• Thread starter jdinatale
• Start date
• #1
155
0
I'm having problems in my differential geometry class. Does anyone know of a good tutorial or set of notes? The 1-form, 2-form, 3-form stuff is confusing and so is the wedge product.
Anyways, here's the problem. After some algebra I arrived at my answer, but I'm unsure of how to incorporate the vectors v, w, x. Ideas?
## Answers and Replies
• #2
MathematicalPhysicist
Gold Member
4,602
313
I am a bit rusty with this subject, but if I am not mistake you should have:
$$v=(f_1,f_2,f_3) \ w=(g_1,g_2,g_3) \ x=(h_1,h_2,h_3)$$
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961 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7928220629692078, "perplexity": 3020.3540366415045}, "config": {"markdown_headings": true, "markdown_code": false, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": false}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-05/segments/1642320303845.33/warc/CC-MAIN-20220122103819-20220122133819-00389.warc.gz"} |
https://www.groundai.com/project/timing-properties-of-shocked-accretion-flows-around-neutron-stars-in-presence-of-cooling/ | Timing Properties of Shocked Accretion Flows around Neutron Stars in Presence of Cooling
# Timing Properties of Shocked Accretion Flows around Neutron Stars in Presence of Cooling
[ [
July 26, 2018February 10, 2019February 13, 2019
July 26, 2018February 10, 2019February 13, 2019
July 26, 2018February 10, 2019February 13, 2019
###### Abstract
We carry out the first robust numerical simulation of accretion flows on a weakly magnetized neutron star using Smoothed Particle Hydrodynamics (SPH). We follow the Two-Component Advective Flow (TCAF) paradigm for black holes, and focus only on the advective component for the case of a neutron star. This low viscosity sub-Keplerian flow will create a normal boundary layer (or, NBOL) right on the star surface in addition to the centrifugal pressure supported boundary layer (or, CENBOL) present in a black hole accretion. These density jumps could give rise to standing or oscillating shock fronts. During a hard spectral state, the incoming flow has a negligible viscosity causing more sub-Keplerian component as compared to the Keplerian disc component. We show that our simulation of flows with a cooling and a negligible viscosity produces precisely two shocks and strong supersonic winds from these boundary layers. We find that the specific angular momentum of matter dictates the locations and the nature of oscillations of these shocks. For low angular momentum flows, the radial oscillation appears to be preferred. For flows with higher angular momentum, the vertical oscillation appears to become dominant. In all the cases, asymmetries w.r.t. the Z=0 plane are seen and instabilities set in due to the interaction of inflow and outgoing strong winds. Our results capture both the low and high-frequency quasi-periodic oscillations without invoking magnetic fields or any precession mechanism. Most importantly, these solutions directly corroborate observed features of wind dominated high-mass X-ray binaries, such as Cir X-1.
X-Rays:binaries - stars:neutron - accretion, accretion disks - shock waves - radiation:dynamics - scattering
Corresponding author: Ayan Bhattacharjee
0000-0002-2878-4025]Ayan Bhattacharjee, \move@AU\move@AF\@affiliationS. N. Bose National Centre for Basic Sciences, Salt Lake, Kolkata 700106, India 0000-0002-0193-1136]Sandip K. Chakrabarti \move@AU\move@AF\@affiliationS. N. Bose National Centre for Basic Sciences, Salt Lake, Kolkata 700106, India \move@AU\move@AF\@affiliationIndian Center for Space Physics, 43 Chalantika, Garia St. Road, Kolkata 700084, India
## 1 Introduction
Modelling of accretion process around neutron stars is largely prompted by significant observational findings ever since they were discovered. Although many of the models are of great phenomenological importance, a unified solution is still not present that describes both the spectral and temporal behavior self-consistently. For black holes, a self-consistent solution that addresses timing and spectral properties simultaneously, exists in the form of Two-Component Advective Flow (hereafter TCAF; Chakrabarti, 1995, 1997, see also, Chakrabarti & Titarchuk 1995 for some spectra of TCAF) where both the Keplerian and sub-Keplerian (low angular momentum) matter accrete together. With a goal to study the applicability TCAF paradigm for neutron stars, we conduct a 2D hydrodynamic simulation of inviscid sub-Keplerian accreting flow around a non-magnetic neutron star. We argue that when the accretion rate is low and viscosity parameter is negligible, our simulations show shocks. When the viscosity is higher, a two-component advective flow (TCAF) would disaggregate out of a single sub-Keplerian component flow, as happened, for example in black hole accretion (Chakrabarti, 1990; Chakrabarti, 1996, Giri & Chakrabarti, 2013).
The temporal variations of both magnetic and weakly-magnetic, accreting NSs are reflected in the Power Density Spectra (PDS) of the lightcurves at different energies. The presence and evolution of QPOs reveal significant details about both the hydrodynamic and radiative transfer processes. We have used the definitions from Wang (2016) for the different classes of Quasi-Periodic Oscillations (QPOs) and the corresponding abbreviations have been used throughout this paper.
• Low-Frequency QPOs (LFQPO): Low-frequency QPOs, with Quality Factor , and amplitudes of , are observed in the range of 5 - 60 Hz. The Flaring-, Normal-, and Horizontal Branch Oscillations all lie in this domain and are respectively abbreviated as FBO, NBO and HBO.
• hecto-Hz QPOs (hHz QPO): A peaked noise usually shows up as the hecto-hertz (hHz) QPO. If the peak is coherent enough to have a quality factor , it is classified as a QPO. The frequency is seen in the range of Hz. It has rms amplitude between and .
• Kilo Hz QPOs (kHz QPO): These are, usually, defined as the QPOs in the range .
We take the following approach to address the validity of our solution: we point to the observational evidences that either supported the TCAF paradigm, or refuted an alternate theory in light of new results. We have touched upon the relevant models in the literature and compared them in terms of predictions of observational results, as an introduction to the studies reported here by us. A more detailed version of this, which is summarized here, can be found in Bhattacharjee (2018).
Elsner & Lamb (1977) carried out the first detailed study of almost radial accretion onto a magnetic neutron star where discussed important properties of the magnetosphere. The spin-up and spin-down mechanism of the star due to this was studied by Ghosh, Lamb & Pethick (1977). The structures of the transition region and the changing of period of the pulsating stars were studied by Ghosh & Lamb (1979a, 1979b). The study of the power density spectra of the source GX 5-1 by Van der Klis et al. (1985) revealed showed intensity dependence of the centroid frequency, width and power of the observed QPOs (20 Hz and 40 Hz) and low-frequency noises (). The interaction of a clumpy disc and a weak magnetosphere was proposed as the cause of the modulation in accretion rate and oscillations in X-ray flux of the source Sco X-1 which reflected as QPOs in 5-50 Hz range. A bimodal behavior in the response of QPO frequency with intensity was found for Sco X-1 by Priedhorsky et al. (1986), where they showed that the 6 Hz QPO, in quiescent state, was anti-correlated with intensity, whereas in the active state the 10-20 Hz QPOs were correlated with intensity. An unsteady flow with low viscosity was proposed to be the cause of the luminosity variations of the boundary by Paczynski (1987). Correlation between the spectral shape, fast variability, temperature and burst duration with accretion rate as well as lack thereof with persistent intensity for 4U 1636-53 lead Van der Klis et al. (1990) to suggest that the accretion rate , which might not be well measured by intensity, determines the source state. Strohmayer et al. (1996) used magnetospheric beat frequency model to explain the constant separation of 363 Hz, which was equal to the burst pulsations, between the twin kHz QPOs that varied between 650-1100 Hz, for the LMXB 4U 1728-34. For Sco X-1, Van der Klis et al. (1997) found: 1) the twin kHz QPO frequency separation, rather than being constant, varied from 310 to 230 Hz and concluded that these peaks are not likely to be explained by any photon bubble model or beat frequency model; 2) both the HBOs, near 45 Hz and 90 Hz, increased with accretion rate. The energy dependent study of twin kHz QPOs and band limited noise by Méndez et al. (1997) suggested that the kHz QPOs were due to oscillations of the boundary layer, very close to the surface and the broad noise was generated from near the inner edge of a disc and these frequencies tracked better than the count rate. Simultaneous HBOs and kHz QPOs for GX 17+2, found by Wijnands et al. (1997), suggested that the phenomena could not be simultaneously explained by the magnetospheric beat frequency model. The rms and FWHM of the lower kHz QPO remained constant with changes in frequency, but that of upper kHz QPO varied. The Z-source Cyg X-2 also discovered to exhibit simultaneous kHz QPOs and HBOs by Wijnands et al. (1998). For the Z-source GX 340+0, Jonker et al. (1998) showed that the twin kHz QPO frequencies moved to higher values with the increase of accretion rate. The rms and FWHM of the upper kHz QPO decreased, whereas the ones corresponding to the lower QPO remained generally constant. Simultaneous HBO was also detected along with its second harmonic between 20 to 50 Hz and 38 Hz and 69 Hz. They also concluded that something other than determined the timing properties, from the study of FWHM of HBOs with states. Wijnands et al. (1998) observed simultaneous kHz QPOs and HBOs for the object GX 5-1 and found similar results.
In Titarchuk et al. (1998, hereafter TLM98) a super-Keplerian transition layer (TL) was invoked to explain the kHz QPOs. Méndez et al. (1998) showed a varying separation between the centroid frequencies of twin kHz QPOs of LMXB 4U 1608-522 and ruled out any simple beat-frequency model. Simultaneous existence of burst oscillation and twin KHz QPOs for 4U 1728-34 was found by Méndez & van der Klis (1999). For the same object, the TL model was used by Titarchuk & Osherovich (1999) where they attributed radial oscillation in viscous time-scale and radial diffusion time-scale as the possible determining factors behind low-Lorentzian frequency and the break frequency, respectively. A correlation between 1)the NS: kHz QPOs and HBOs, 2)BH: QPOs and noises, of same type but varying 3 orders of magnitude in frequency and coherence was found by Psaltis et al. (1999) which suggested that the variations are systematic and related by similar processes in the two types of compact objects. Different modes of QPOs observed for 4U 1728-34, were explained by adding the effects of Coriolis forces and interaction of magnetosphere by Titarchuk et al. (1999). The study of Sco X-1 by Dieters et al. (2000) revealed that the position on the Z-track or the spectral state was not the only parameter that governs the behavior of the source. A new broad component in the PDS of GX 340+0 between 9 Hz to 14 Hz was discovered by Jonker et al. (2000). For the source Sco X-1, Yu et al. (2001) the ratio of lower to upper kHz QPO amplitude and the upper kHz QPO frequency were anti-correlated with the count rate that varied in the NBO timescale (6-8 Hz) and suggested some of the NBO flux was generated from inside the inner disc radius and the radiative stress modulated the NBO frequency. A long term study of a total of 13 Z and atoll sources by Muno et al. (2002) showed that similar three branched color-color patterns are traced out by both, which was previously not recorded because of incomplete sampling, suggested a similarity between the two types of sources.
The decomposition of PDS into 4 primary Lorentzians for both BHs and NSs by Belloni et al. in 2002 revealed that the physical processes of HFQPOs might be the same for both types of compact object, and possibly independent of the stellar surface. In the same year, Mauche extended the QPO correlation between BH, NS to the case of White Dwarfs, over 5 orders of magnitudes, further suggesting a common mechanism of oscillations in these systems. From their studies of multiple accreting NSs, Wijnands et al. (2003) suggested that the QPOs can be understood in terms of resonances at specific radii in an accretion disc. Barret et al. (2005) ruled out the possibility of any model involving clumps and disc/shock oscillations were suggested to be the more likely mechanism of generating QPOs in LMXB 4U 1608-52. Belloni et al. (2005) showed that a biased sampling leads to the finding of ratio of upper and lower kHz QPO frequencies around 3/2, which indicated that a simple resonance model of a Keplerian disc is unlikely to address the kHz QPOs. From the one-to-one correspondence between the LFQPOs in BHs and NSs, Cassella et al. (2006) inferred that the physical mechanisms that determine these oscillations, are in favor of a disc origin of oscillation and rules out models involving interaction with the magnetosphere or the surface. Méndez (2006) suggested that one possible mechanism of generation of kHz QPOs would be that the mass accretion rate sets the size of the inner radius of the disc which determines the QPO frequency as well as the relative contribution of the high-energy part of the spectrum to the total luminosity. To explain the lower value of kHz QPOs in Cir X-1, Boutloukos et al. (2006) pointed that a high radially accreting flow is more likely than a Keplerian disc for the source. The study of NBOs for Sco X-1 by Wang et al. 2012 also suggested a radial oscillation as the centroid frequency varied non-monotonically with energy.
## 2 TCAF around an NS
In Bhattacharjee and Chakrabarti (2017), we discussed at length how the spectral signature of TCAF are present in observations of accretion flows around neutron stars. Here, we include more of those features which pertain to the timing properties of such flows and how there is a connection between the TCAF scenario and the observed results. A detailed version of this comparative study is reported in Bhattacharjee (2018), which we summarize here. The spectral and timing properties of accreting matter around a black hole could not be explained by a standard Keplerian disc (Sunyaev & Truemper, 1979, Haardt and Maraschi 1993, Zdziarski et al. 2003; Chakrabarti 1995; CT95; Chakrabarti, 1997). The two main components of the spectrum are: 1. a thermal component which resembles a multi-colour blackbody radiation (Shakura & Sunyaev 1973), 2. a power-law-like component generated by inverse Comptonization of the thermal or non-thermal electrons (Sunyaev & Titarchuk, 1980, 1985). Although many models deal with the production of a Compton cloud that generates the power-law, many such possible scenarios required excessive fine-tuning of accreting matter and are self-consistent or not physical (for a review, see Chakrabarti 2017). TCAF, which is based on the transonic flow solution, is a unique self-consistent solution (Chakrabarti, 1995, 1996, 1997), equally applicable for BHs and NSs when proper inner boundary condition is chosen. All the aspects of spectral and temporal properties are addressed at the same time by the TCAF paradigm. In this scenario, the low viscosity advection component produces a centrifugal barrier supported boundary layer or CENBOL very close to a compact object. A shock transition defines the boundary of CENBOL. This shock surface may be stationary, oscillating or propagatory (Chakrabarti 2017 and references therein). The post-shock region behaves as a natural reservoir of hot electrons. The highly viscous component of the flow near the equatorial plane becomes a Keplerian disc (Giri & Chakrabarti 2013). This disc emits a multi-colour blackbody radiation which are intercepted and re-radiated by the CENBOL to create the power-law-like component (Chakrabarti, 1997; Garain et al. 2014, hereafter GGC14). The power-law component usually has an exponential cut-off where recoil becomes important.
The shock formed in the transonic flows around BHs and NSs can oscillate due to resonance (Molteni et al. 1996, hereafter MSC96) or non-satisfaction of Rankine-Hugoniot condition (Ryu et al. 1997). The variation in the size of the CENBOL results in modulation of intensity of the hard X-ray, manifesting as the LFQPOs. The CENBOL also acts as the source of outflows and jets. When excessive soft photons cool the CENBOL down, the jet disappears as well. There are clear observational evidence of two-component advective flows in several black hole candidates (Smith et al. 2001; Smith et al. 2002; Debnath et al. 2013; Mondal et al. 2014; Dutta & Chakrabarti, 2016; Bhattacharjee et al. 2017; Ghosh and Chakrabarti, 2018).
A natural explanation of the phenomenological Compton clouds for the black hole accretion can be found in the TCAF paradigm. Apart from the region near the innermost boundary, the flow accreting from the outer edge of the disc has little knowledge about the nature of the compact object. Therefore, we anticipate, especially when the magnetic field is weak ( Gauss), even an NS accretion would have a CENBOL which forms away from the surface of the NS. The advective matter almost freely falls under gravity till it reaches the surface of the NS. Thus, in a neutron star accretion, two shocked layers woould be simultaneously present: One is similar to the normal boundary layer (NBOL), and the other is similar to the CENBOL in a black hole accretion (Chakrabarti 1995). Only CENBOL is present in a black hole accretion. In the following segment, we point to some of the key similarities between the TCAF scenario and the flow configuration demanded by observations. The conclusions of Chakrabarti (1996) and Chakrabarti & Sahu (1997) that the boundary condition of the gravitating object (BH or NS) modifies the solutions of the transonic flows only in the last few Schwarzschild radii, are strengthened by these points.
The following observed features can be reproduced when the accretion flow on a neutron star is TCAF:
• The Low-Frequency QPOs () shows a bimodal behaviour (Priedhorsky et al. 1986): The intensity is controlled by two separate accretion rates. One increases the oscillation radius, another reduces it.
• BHs, NSs and WDs show correlated QPOs (Psaltis et al. 1999, Belloni et al. 2002, Mauche 2002): A stellar surface or magnetosphere should not be required by the generalized model.
• Sources of varying intensity having similar kHz QPO frequency () (Méndez et al. 1998): More than one accretion rates control the QPOs.
• Long coherence time of kHz QPOs (Barret and Olive 2005): Vertical and radial oscillations would be preferred. It is unlikely that clumpy disc models with azimuthal asymmetry would generate QPOs in Keplerian orbital time-scale.
• A ‘mass’ accretion rate which controls the relative contribution to high energy part of the spectrum also decides the inner edge of the disc that generates kHz QPOs (Méndez 2006).
• The Compton cloud acts as the base of the jet (Paizis. et al. 2006).
• The state transition was controlled by more than just a single accretion rate (Barret 2001; Barret and Olive 2002).
• Some NSs (For Cir X-1, Boutloukos et al. 2006) show low : An advective flow (radial accretion) is preferred over a Keplerian disc.
We divide our study of accretion flow into two broad classes: 1. The flow is inviscid, advective and has a low efficiency of radiation. It also comprises of winds from the companion star. 2. The flow has a significant viscosity to create two-component advective flow and has a blackbody radiation emitting disc.
The main focus of the present work is to concentrate on Class 1 flows, namely, the effects of angular momentum of a sub-Keplerian flow in absence of significant dynamic viscosity. In such a scenario, which can occur when the accretion rate is relatively low as compared to the Eddington limit, we assume the bremsstrahlung cooling to be the dominant process. These classes are not that well explored in the literature as in the case of black hole accretion using hydrodynamic simulations, and thus we focus on this domain of solutions first. However, when the viscosity is high enough to produce a Keplerian disc on the equatorial plane, the blackbody emission from the disc as well as the non-local cooling processes such as Comptonization would become significant. Those aspects of Class 2 flows are not within the scope of this paper and will be discussed in a subsequent paper (Bhattacharjee and Chakrabarti, in preparation). TLM98 and subsequent works have tried to explore this domain, although with the assumption that the entire disc is Keplerian to begin with. In Bhattacharjee & Chakrabarti (2017, hereafter BC17), we have shown similarities and differences between the TLM98 scenario and TCAF paradigm in spectral analysis and will carry out timing study in a subsequent paper.
## 3 Method
The Smoothed Particle Hydrodynamics (SPH) method was introduced by Monaghan (1992). It has since been used in many astrophysical systems, including simulation of accreting matter around black holes to simulate accretion in 1D (Chakrabarti & Molteni 1993, hereafter CM93); 2D flows (Molteni, Lanzafame & Chakrabarti 1994, hereafter MLC94); viscous Keplerian discs (Chakrabarti & Molteni 1995, hereafter CM95); resonance oscillation of shocks due to cooling in 2D (MSC96); comparative study of shocked advective flows using SPH and TVD schemes (Molteni, Ryu & Chakrabarti 1996, hereafter MRC96); thick accretion discs (Lanzafame, Molteni & Chakrabarti 1998, hereafter LMC98); bending instability of an accretion disc (Molteni et al. 2001a, hereafter M01a; Molteni et al. 2001b, hereafter M01b); interaction of accretion shocks with winds (Acharyya, Chakrabarti & Molteni 2002, hereafter ACM02); and effect of cooling on the time dependent behavior of accretion flows (Chakrabarti, Acharyya & Molteni 2004, hereafter CAM04).
We base our studies of accretion onto neutron star mostly on MSC96, though we modify the SPH algorithm to suit our need to handle both hot and cold particles in the neutron star environment.
### 3.1 Model Equations
We consider a rotating, axisymmetric, inviscid flow around a neutron star. We consider the magnetic field to be negligible and ignore its effects completely. The gravitational force due to the compact object was modelled using the pseudo-Newtonian potential of Paczynski and Wiita (1980). The matter density (), isotropic pressure () and the internal energy () of the flow are related to each other through . The adiabatic index , is kept constant throughout our simulations. We used a single-temperature model for the electrons and protons. The specific angular momentum is varied from case to case but it is constant everywhere in a simulation setup, as the flow is purely inviscid. Furthermore, the SPH code uses toroidal particles and thus it strictly preserves . The hydrodynamic code uses dimensionless quantities for computation. However, the cooling mechanisms require physical units (cgs is used here). For that purpose, all the relevant quantities are non-dimensionalized using their corresponding reference values. We use density of injected particles of the flow at the outer edge , the speed of light , and the Schwarzschild radius of the neutron star mass , as the reference density, velocity, and distance, respectively. From that we can derive the units of time , specific angular momentum , mass , and mass accretion rate .
We provide the Lagrangian formulae for the two-dimensional fluid dynamics equations for Smoothed Particle Hydrodynamics (SPH) in cylindrical coordinates, below.
The conservation of mass is given as (LMC98)
DρDt=−ρ→∇⋅→v (1)
(here, is the comoving derivative).
The conservation of momentum is given by (LMC98, dropping the viscous terms from Eq. 2)
D→vDt=−1ρ→∇P+→g+λ2r3^r (2)
where, is the radial direction vector and
→g=−1−C2(R−1)2→RR, (3)
gr=−1−C2(R−1)2rR, (4)
gz=−1−C2(R−1)2zR. (5)
Here, , , and is the radiative pressure term arising out of the blackbody emission from the surface of the star. We have assumed the term to be isotropic for our simulations.
To achieve a better accuracy, we use a form of energy conservation where the sum of kinetic and thermal energies are used instead of only thermal energy (Monaghan 1985). Then, the energy conservation can be written as (following Eq. 9c of MSC96 and Eq. 11 of LMC98)
DDt(e+12→v2)=−Pρ→∇⋅→v+→v⋅(D→vDt)−ζ1/2ρeα (6)
Here, is the non-dimensional bremsstrahlung loss coefficient, as defined in MSC96,
ζ1/2=jρrefxrefT1/2refc3m2p (7)
and
Tref=c2mpμ(γ−1)k (8)
where and cgs unit for ionized hydrogen (Allen 1973), is the mass of the proton, and is the Boltzmann constant. The subscript 1/2 to signifies the use of a cooling law with a constant which is identical to the bremsstrahlung case ().
### 3.2 SPH: Implementation of the cooling law
We use the method described in detail by MSC96, while making changes to match the notations used so far. We have assumed the flow to be axisymmetric and thus, all the equations are written for cylindrical geometry. The interpolating kernel which is a function of cylindrical radial coordinate and th particle of mass as (MSC96)
mk=2πρkrkΔ→Rk. (9)
Any smooth function at position can be defined as (MSC96),
≈∑kmk2πρkrkA(→Rk)W(→Rk−→Ri;h), (10)
where is the particle size. This simplifies the expression of the conservation laws and quantities that can be computed easily. As an example, the density at position can be simplified as,
ρ(→Ri)≈∑kmkrkW(→Rk−→Ri;h), (11)
which satisfies the continuity equation in cylindrical coordinates (MSC96).
The equations of motion to be solved using SPH reduces to three separate ones. The radial component of momentum equation,
(DvrDt)i=∑kmkrk(Piρ2i+Pkρ2k+Πik)∂Wik∂ri+λ2r3i−1−C2(Ri−1)2riRi, (12)
the vertical component of the momentum equation,
(DvzDt)i=∑kmkrk(Piρ2i+Pkρ2k+Πik)∂Wik∂zi−1−C2(Ri−1)2ziRi, (13)
and the specific energy equation which can be written as,
(D(e+→v2/2)Dt)i=∑kmkrk(Piρ2i+Pkρ2k+Πik)−Λiρi+→vi⋅(D→vDt)i. (14)
where, is the cooling term.
The kinematic dissipation is mimicked using artificial viscosities (MSC96),
,
,
, .
where, and are the artificial viscosity coefficients.
The equations (12-14) have been adopted from MSC96 and LMC98, with the introduction of the term . It is to be noted that the kinematic viscosity modifies the energy significantly but does not modify the angular momentum beyond of the initial value. Thus, our simulations effectively reproduces the flow with constant angular momentum. The abbreviations for density and sound speed are taken from Monaghan (1992):
, .
### 3.3 Conservation of angular momentum
We have used the following equation (LMC98 and MSC96) for the conservation of angular momentum,
(DvϕDt)i=−(vϕvrr)i+1ρi[1r2∂∂r(r3μij∂∂r(vϕr))]i, (15)
where, is the kinematic viscosity. The terms and control the amount of necessary to reduce oscillations in shock transitions. However, the on the right hand side and made no significant contribution. We determined the value of for the particle and use in Eqn. 12. It was observed that for all the cases we have tried, the determined angular momentum was almost constant and equal to the injected values up to an error of . The average value over all particles deviated even less from the injected value, e.g. for C1 , matching the injected value up to 5 decimal places. This little numerical error is due to the fluctuation of the values of and . Thus the obtained values of are effectively equal to the of the injected particles, which is obtained as a natural consequence of the conservation of angular momentum throughout the flow. As the flow is always sub-Keplerian, it can continue to the inner boundary which is the surface of the star. A part of the flow is absorbed into the star beyond where the rotational velocity matches with that of the star and the surplus rotational kinetic energy is released through (see Boundary Conditions). As an example, the rate of transport of angular momentum onto the star for C1, i.e., the spin-up torque was such that the spin-up rate was roughly around , where, the moment of inertia . Thus any change of the spin of the star due to this feedback effect can be safely ignored for the purpose of calculations for the runtimes we have chosen.
### 3.4 Boundary Conditions
For our simulations, the pseudo-particles (or, just ‘particles’ used in the text) are injected from with the same specific energy and specific angular momentum. The flow is assumed to be in vertical equilibrium when injected. The particles are tracked as long as they are within and , where, . The choice of was made so to minimize the computational time taken to track isolated particles moving far away from the inflow region. We have also carried out our simulations for a rectangular simulation box, but no significant changes were observed. For , injection velocity at equatorial plane with and sound speed was done which are appropriate for the transonic branch. Similarly, for cases to , to ensure injection with same total energy and Mach number, we had to choose and . In order to implement a reflection boundary condition at the inner boundary of we used a reflecting condition for the velocity component . For the component, a sliding or slipping boundary condition is used, where the flow maintains its value at the surface. The choice of boundary condition for component was based on both physical and numerical factors. We have tried multiple scenarios involving the presence and absence of absorption condition and the effect of no-slip and slip conditions with zero and non-zero viscosity. What we found was that, inviscid sub-Keplerian flows reaching the surface of the star would undergo the following processes: piling up at the boundary forming a highly dense layer a local increase in viscosity redistribution of the angular momentum to match the of the layer with that of the star being absorbed, effectively. Numerically, the most efficient scheme for inviscid flows turned out to be the one with no-slip and absorption, after reaching the surface, which implicitly takes care of the mentioned steps. The explicit study of viscous flows, with different inner boundary conditions and the transition mentioned above, are beyond the scope of the present work and are to be reported in a separate paper as stated earlier. Thus, for the cases reported here, a no-slip condition is used for the azimuthal component where the of the flow is matched with the angular velocity of the star () at the surface. For our calculations, . Along with the cooling criteria, these conditions allow matter to settle down on the surface of the star and also allows meridional motion from the equatorial region towards the poles (and vice-versa). However, if the flow reaches the , it is immediately absorbed and all the thermal and kinetic energy of the particle is assumed to be released as blackbody radiation. In the present simulations we did not study the emission due to Comptonization of seed photons originating from bremsstrahlung or blackbody radiation. We, however, included the effects of radiation pressure on the flow through the quantity . We report the cases where the temperature is self-consistently modified by taking into account the additional flux arising out of energy of the accreted particles. The initial surface temperature of the neutron star was kept constant for all cases ( to ) at . The term is controlled by the total energy deposited by the particles at the surface of the star () and it given by,
C(t)=T4NS(t)σbbR2NSmpcσT, (16)
where . Here, is the Stefan-Boltzmann constant, is the mass of proton, is the Thompson scattering cross section.
### 3.5 Coalescence of Particles
One of the major problems with the previous version of the code was that it did not dynamically evolve when the particles came very close to each other () and the resulting hydrodynamical timescale became very small. This problem is even more accute in our case as particles tend to aggregate on the surface of the star. In the original code, within time steps the value of and effectively stopped the evolution. A simple absorption condition at the boundary did not solve the problem as the aggregates grew beyond the surface’s immediate vicinity. To circumvent this, we implemented a 2-particle coalescing scheme (adopted from Vacondio et al. 2013) when the inter-particle distance .
After each time step, we check for neighbours using a algorithm. The neighbour list of a particle is then searched for all such neighbours , for which . The minimum of such values and the corresponding pair is selected. If such pairs are found, a list of such pairs is made and the following scheme is applied to coalesce particle-pairs .
To conserve the total mass:
mk=mi+mj,k=min(i,j). (17)
We preserve the total momentum, by using:
→vk=mi→vi+mj→vjmi+mj. (18)
We also preserve the total thermal energy, by using:
ek=miei+mjejmi+mj. (19)
The new location of the particle is determined by,
→Rk=mi→Ri+mj→Rjmi+mj. (20)
After going through the list of all such pairs, a standard re-indexing is done for all the particles still left in the system. As a result, the average number of particles present in the simulation stayed between and for and between and for .
### 3.6 Timing Analysis
We computed the total emitted energy due to bremsstrahlung by integrating the emission per unit mass () over the particles existing in the simulation ,
E(t)=i=n∑i=1Λimi/ρi. (21)
As a consequence, the densest and hottest regions contributed more to the time variation of the bremsstrahlung loss. In order to probe the hydrodynamic characteristics of CENBOL and NBOL, the emitted energy was plotted against time to generate the lightcurve. To extract periodic features, we used NASA’s ftools package to create the fast Fourier transformed Power Density Spectra (PDS) from the lightcurves. Data was gathered after every to generate the lightcurve. We used powspec command, with a rebinning factor of -1.05 for all the cases to generate the PDS. Any oscillatory signature (such as a Quasi Periodic Oscillation or a peaked noise) is reflected as a peak in the PDS. We report only those 5 cases (see, Table 1.) where significant variations of QPOs are observed. To avoid the effects of the transient phase, we only used data collected from to . A Lorentzian profile is used to fit a QPO in the PDS. We determined the centroid frequencies, full-width half maxima and rms power up to confidence level. While fitting the QPOs with Lorentzians, we only fitted the fundamental frequency of a type of QPO, when the harmonic is overlapping with another fundamental frequency. In case of such an overlap we take the best statistical fit (one peak or a mean position as the case demanded). When no such overlap occurs, and the harmonic feature is significant, the corresponding Lorentzian is fitted and mentioned in the text (Table 1).
## 4 Results
We studied multiple cases (see, Table 1) by varying specific angular momentum (), radius of the star (), accretion rate (, alternatively used as the halo accretion rate ), cooling index (), one at a time, to study the effects in accretion and outflow.
We first discuss a typical scenario in detail to highlight the hydrodynamical aspects of the flow.
Case C1: In order to demonstrate hydrodynamic properties, we first focus on case . The initial simulation parameters are mentioned in the Table 1. The simulation was run for time steps (), which is equivalent to dynamical time steps at . The cooling process was switched on after (). The system settled into a steadily oscillating state after a brief transient phase (up to ). Indeed, the temperature of NBOL was found to fluctuate around keV even though initially its value was chosen to be keV. Figure 1(a) shows variation of NBOL temperature during our simulation. This would induce fluctuations of the NBOL height as well. Details of the behaviour of NBOL is beyond the scope of the current paper and would be published elsewhere. In this case, we studied PDS of the mass outflown through the upper quadrant. The hHz frequency corresponding to vertical oscillation was found at , with a harmonic at . For black holes, Molteni et al. 2001 found such oscillations due to bending instabilities in the flow. When scaled for the mass of the neutron star (here, assumed to be for computational purposes), the frequency range comes out as 20-300 Hz. Thus, we can clearly identify the oscillations in the lightcurve as well as the mass outflow due to such instabilities, which is also reflected in Fig. 2(c-d).
In Fig. 1(b), the velocity in plane is plotted for all the particles. The Mach Number values are shown in the colour gradient. Multiple turbulent cells are seen to be formed due to the interaction of wind and accreting matter. The formation of outflow, in both upper and lower quadrants, from the post-shock region of CENBOL is also captured. In the lower quadrant, a portion of the outflow falls back on to the inflow as a feedback.
In Fig. 1(c), the variation of the rate of transfer of angular momentum (N, see sect. 3.3) with time is plotted for accretion (black) and outflows (red). Given that the specific angular momentum of the flow remains constant, the variation of the transfer rate with time depends on the mass flow rate in accretion and outflow, respectively. As the flow is always sub-Keplerian, the solution allows the matter to fall onto the star and transfer the angular momentum on the surface of the star. However, the spin-up torque plotted in the Figure was such that it corresponded to a spin-up rate of . The value agrees well with observational results and predictions from other models (Bildsten 1998; Revnivtsev & Mereghetti, 2015; Sanna et al. 2017; Bhattacharyya & Chakrabarty, 2017; Gügercinoǧlu & Alpar, 2017; Ertan 2018). The rest of the angular momentum is carried out by the outflows in both quadrants.
In Fig. 2(a), we show the density contours []. The temperature contours (logarithmic scale) are plotted in Fig. 2(b). The contours of constant Mach number for accreting matter, at time , is shown in Fig. 2(c). The panel 2(d) shows the Mach number contours for the same case C1, at time . The flow puffs up after the centrifugal pressure supported shock (CENBOL) and acts as the base of the outflowing matter. Matter nearest to the star is observed to be hottest and densest. A dense and hot outflow is seen to emerge from within the CENBOL region. The Mach number contours show that the flow has time-dependent asymmetric distribution about plane. For C1, the high angular momentum creates the outer shock at around on the equatorial plane. The subsonic flow beyond the shock surface slowly becomes supersonic near the inner boundary of the star and finally settles on the surface through a strong shock. Notice that the Mach number contours near the edge of the star show supersonic behaviour of the flow and no contours of subsonic Mach number are plotted. This is due to the fact that in the plotted case, the shock surface was very close to the boundary and the subsonic pseudo-particles were absorbed at the surface, before being written out, within the code.
Case C2: When is reduced from to , it reduces the asymmetry around plane (Fig. 3a). The shock near the star becomes more prominent and the outflow profile changes. For , most of the outflow is generated from the immediate vicinity of the post-shock region of the CENBOL. We plot the ratio of the mass outflow to the mass accreted onto the star in unit time (denoted by ) for both and in Fig. 3(c). Apart from the initial higher values for , the ratio is comparable. However, the particle coalescing scheme merges the particles in higher density region, which reduces the number of particles in the simulation. The inset panel of Fig. 3(c) shows the same comparison in terms of the ratio of number of particles outflown to the number of accreted particles in unit time (denoted by ). The lower value for further affirms the fact that bulk of the outflow is generated near the NBOL for . The outflow in Fig. 3(a) also undergoes a shock transition before becoming transonic again. In Fig. 4 (c), we plot the PDS of bremsstrahlung loss for the case C3. As was decreased from to , the centrifugal pressure dominated force is decreased. However, the flow was injected with same total energy as that of case C1 which resulted in a higher radial velocity. This increases the ram pressure of the fluid flow and prompts the resonance oscillation to take place at a smaller radius. The resulting oscillations are also seen to be dominated by the radial motion as compared to the vertical motion. The CENBOL moves closer to the star surface. The hecto-Hz QPO is still present and observed at . We also observe the twin kHz QPOs between and . The centroid frequencies of the lower and upper kHz QPOs are at and , respectively.
Case C3: In Fig. 4 (d), we plot the PDS of bremsstrahlung loss for C3. As was increased from to , the effective radiative cooling due to the bremsstrahlung process is also increased (higher ). The decrease in cooling timescale, prompts the resonance oscillation to take place at a smaller radius. This brings the NBOL closer to the surface. The hecto-Hz QPO is also observed at . Both the lower and upper kHz QPOs show an increase in centroid frequency (compared to C2) at and , respectively.
Case C4: As was increased from to , the effective radiative cooling due to the bremsstrahlung process decreased (lower ). The increase in cooling timescale, prompts the resonance oscillation to take place at a larger radius. This pushes the NBOL away from the surface. The PDS of bremsstrahlung loss for the case C4 is shown in Fig. 4(e). The low-frequency QPOs are observed at and at . The hecto-Hz QPO is also observed at . Both the lower and upper kHz QPOs are also observed at and , respectively.
Case C5: In this case, as was increased from to , the effective radiative pressure due to the blackbody emission from the surface of the star decreased (lower ). This aided the gravitational force in bringing both the shocks closer to the surface. The reduction of the outer edge of CENBOL increased the centroid frequency, above , corresponding to the low-frequency QPO and its harmonic , making them detectable (Fig. 4(f)). The hecto-Hz QPO is also observed at . Both the lower and upper kHz QPOs are also observed at and , respectively.
## 5 Conclusions
In this paper, we have made an effort to understand the dynamics of an inviscid, rotating, geometrically thick and optically thin flow around a weakly magnetic neutron star using smoothed particle hydrodynamics. We add modified bremsstrahlung cooling so as to particularly study the timing properties of the centrifugally driven shocks (CENBOL) as well as the density jump (normal boundary layer or NBOL) formed on the star surface due to sudden arrest of infalling matter. Such simulations were done for black holes earlier (MLC94, MSC96, MRC96, M01a, M01b, ACM02, CAM04, GC13, GGC14, Deb et al. 2017) and oscillations of the CENBOL were found in radial and vertical directions. These oscillations were then identified with the low frequency QPOs observed in black hole candidates.
In presence of a hard boundary on the neutron star surface, we expect another oscillation of higher frequency as well as others due to non-linear interactions of the flows. Our present simulations indeed show complex timing properties of the radiation as well as the flow dynamics. For this, we chose the flow to have an accretion rate () below the Eddington limit for all the cases we studied. The exponent in the cooling rate was varied from (bremsstrahlung) to to observe the effects of the strength of cooling on the oscillation of shocks. The specific angular momentum was chosen based on the recent study by Deb et al. (2017) where an onset of vertical oscillation was seen between the two values chosen here. The variation of the radius of the neutron star had a more complex effect as it controlled the effects of radiation pressure on the hydrodynamics through the parameter when a self-consistent variation is chosen. It is also to be noted that for the timescales of simulations C1 to C5, the mass and momentum deposited on the star were negligible as compared to the star’s mass and spin. This accumulation of mass and momentum would become significant for timescales of the order of years or more, which is outside the purview of the current paper. However, the energy release at the surface was found to be significant, resulting in a measurable change of .
We show, among other things, that the simulations produce both low and high-frequency QPOs and the oscillations last during the whole simulation period (more than 200 dynamical timescales measured at the injected flow radius, i.e., ). This suggests that the QPOs are formed due to a part of the flow dynamics and not a transient effect as inferred by others (e.g., Barret and Olive, 2005). We measure the QPO frequencies and find that both the centroid frequencies and Q factors match well with observed results of neutron stars such as GX17+2, 4U 1728-34 and Cir X-1. We believe that the advective flow suggested in the literature while explaining the behavior of the source Cir X-1 (Boutloukos et al. 2006), may be the same as the dynamic transonic flow solution we discuss here. We showed that the presence of angular momentum itself can generate multiple modes of oscillation in CENBOL and NBOL, manifesting as QPOs in the PDS, in presence of cooling. In Fig. 1(b), 2(c-d), 3(a), we see different types of shocks are being formed. The outer shock was found to be vertical near the equatorial plane and oblique away from the plane, very similar to what was seen for simulations around black holes (MLC94). The bending instabilities reported in M01a, are also found here and correspond to the hecto-Hz oscillations found in the PDS.
So far, in the literature, a model which appears to be capable of phenomenologically addressing both timing and spectral properties is the transition layer (TL) model of TLM98 who assumed the disc to be Keplerian to begin with. The viscosity was also assumed to be high enough to maintain a Keplerian distribution. The QPOs are then explained as the oscillation of the TL at different orbital frequencies. An extended TL was used in the COMPTT and COMPTB models for the analysis of spectra of accreting NSs. Many LMXBs have been studied using the COMPTB framework, such as 4U 1728-34 (Seifina et al. 2011), GX 3+1 (Seifina and Titarchuk 2012), GX 339+0 (Seifina et al. 2013), 4U 1820-30 (Titarchuk et al. 2013), Scorpius X-1 (Titarchuk et al. 2014), 4U 1705-44 (Seifina et al. 2015) etc. The HMXB 4U 1700-37 has also been examined using the same model (Seifina et al. 2016). Two COMPTB components were needed in general for spectral fitting. The one corresponding to a cloud closer to the star had a relatively lower temperature and the one closer to the Keplerian disc typically had higher temperature (cited works above). The one corresponding to Comptonization of NS surface photons, showed a saturation in COMPTB model’s spectral index (Farinelli and Titarchuk, 2011). This index is different from the spectral index found by fitting the power-law component of the spectrum. The latter can have a continuous range of values depending on the two accretion rates as shown in BC17. However, since the source of high viscosity required to sustain a complete Keplerian distribution remains elusive and physical processes to create two Compton clouds out of a Keplerian disc is also not demonstrated, we preferred to start with a sub-Keplerian inviscid advective flow onto a neutron star which is a general configuration. In presence of higher turbulent viscosities, this flow will become a Keplerian disc easily as in the case of black hole accretion by simply redistributing angular momentum (Chakrabarti, 1990, 1996, Chakrabarti 2017), and thus in softer states, the flow could resemble a configuration similar to the TLM98 model. In general, the flow should have both the sub-Keplerian and Keplerian components (Chakrabarti, 1995; 1997, 2017, CT95). The infall timescales from Chakrabarti 1995 (see also, Chakrabarti 1997) have the similar dependence with the radial distance . The absolute value only differs from Keplerian orbital time scale by a factor of , being the shock compression ratio. This, in principle, suggests that the same numerical values of frequencies for all such sources could be produced by the TCAF scenario, even when the flow is not-Keplerian to begin with and the viscosity is too low to form any TL. The pre-shock and post-shock regions of NBOL are orders of magnitude denser than those of CENBOL and contribute to higher frequency oscillations as well. In the TCAF scenario, the physical NS boundary aids in the formation of inner shock (NBOL) apart from the the CENBOL surface, which is formed even in BH accretion.
We found that the ratio varied from to and the ratio varied from to in our simulations. The Q factors of lower kHz QPOs were always found to be greater than the Q factor of the upper one. This agrees well with observational results (Barret et al. 2005). In our cases, the separation between and increased with accretion rate, which is similar to results of Cir X-1 (Boutloukos et al. 2006). In fact, the values of Table 1, when scaled with the mass of Cir X-1, lies in the same ball park figure as that found in observation.
In passing, we may mention that our simulation clearly demonstrated that the advective flows onto a non-magnetic neutron star create a stable configuration. The flow with a sub-Keplerian specific angular momentum has at least two density jumps in accretion and shocks were also found in the outflows. In presence of cooling, the shocks underwent oscillations in both radial and vertical directions and were manifested as QPOs in the PDS of bremsstrahlung loss from the system. We also find that the shock location, and hence the QPO frequencies depend on many parameters of the flow, viz., the specific angular momentum , the accretion rate , the radius of the star and the strength of cooling , which we studied here.
The most general flow configuration should depend on the spin, mass and radius of the star and the viscosity of the flow. In this paper, we kept the spin frequency to be constant at 142 Hz, the mass was kept to be constant at 1.0 and viscous effects were ignored. In a future paper we will vary these crucial parameters and general a spectrum of steady and oscillating solutions. Non-local cooling processes as well as electron energy distribution due to shock acceleration are yet to be incorporated in the simulation. From the results of BC17, it is clear that when accretion rates are high for a hot accretion flow, Compton cooling has a significant effect on the temperature of the flow. In future, we wish to couple Monte Carlo simulation with this hydrodynamic code to get time-dependant spectral variation. The results would be presented elsewhere.
## Acknowledgement
AB would like to acknowledge Prof. D. Molteni and Dr. G. Lanzafame for their 2D SPH simulation source code, written by them with SKC, which was modified for case of neutron star with cooling and particle coalescing schemes to produce the results used in this paper.
## References
• 1 Acharya, K., Chakrabarti, S. K., & Molteni, D., 2002, Journal of Astrophysics and Astronomy, 23, 155
• 2 Barret, D., 2001, Advances in Space Research, 28, 307
• 3 Barret, D., & Olive, J.-F., 2002, ApJ, 576, 391
• 4 Barret, D., Kluźniak, W., Olive, J. F., Paltani, S., & Skinner, G. K., 2005, MNRAS, 357, 1288
• 5 Barret, D., Olive, J.-F., & Miller, M. C., 2005, MNRAS, 361, 855
• 6 Bhattacharjee, A., 2018, in Exploring the Universe: From Near Space to Extra-galactic Mukhopadhyay, B & Sasmal, S. (Eds.), ASSP, 53, 93, Springer (Heidelberg)
• 7 Bhattacharjee, A., Banerjee, I., Banerjee, A., Debnath, D., & Chakrabarti, S. K., 2017, MNRAS, 466, 1372
• 8 Bhattacharjee, A., & Chakrabarti, S. K., 2017, MNRAS, 472, 1361
• 9 Bhattacharjee, A., & Chakrabarti, S. K. 2019 (in preparation)
• Bhattacharyya & Chakrabarty(2017) Bhattacharyya, S., & Chakrabarty, D. 2017, ApJ, 835, 4
• 10 Belloni, T., Méndez, M., & Homan, J., 2005, AAP, 437, 209
• 11 Belloni, T., Psaltis, D., & van der Klis, M., 2002, ApJ, 572, 392
• Bildsten(1998) Bildsten, L. 1998, American Institute of Physics Conference Series, 431, 299
• 12 Boutloukos, S., van der Klis, M., Altamirano, D., et al., 2006, ApJ, 653, 1435
• 13 Chakrabarti, S. K., 1985, ApJ, 288, 1
• 14 Chakrabarti, S. K., 1989, MNRAS, 240, 7
• 15 Chakrabarti, S. K., 1990, MNRAS, 243, 610
• chakrabarti(1995) Chakrabarti, 1995, in Ann. NY Acad. Sci., 759, Seventeenth Texas Symposium on Relativistic Astrophysics and Cosmology, ed. H. Bohringer, G.E. Morfil & J. Truemper, 546
• 16 Chakrabarti, S. K., 1996, ApJ, 464, 664
• 17 Chakrabarti, S. K., 1997, ApJ, 484, 313
• 18 Chakrabarti, S. K., 2017, Proceedings of 14th Marcel Grossman meeting on General relativity, M. Bianchi, R. Ruffini, R.Jantzen (Eds.), 369-384 (World Scientific:Singapore), (arXiv:1604.05955)
• 19 Chakrabarti, S. K., Acharyya, K., & Molteni, D., 2004, AAP, 421, 1
• 20 Chakrabarti, S. K., & Molteni, D., 1995, MNRAS, 272, 80
• 21 Chakrabarti, S. K., & Sahu, S. A., 1997, AAP, 323, 382
• 22 Chakrabarti, S., & Titarchuk, L. G., 1995, ApJ, 455, 623
• 23 Debnath, D., Chakrabarti, S. K., & Nandi, A., 2013, Advances in Space Research, 52, 2143
• 24 Dutta, B. G., & Chakrabarti, S. K., 2016, ApJ, 828, 101
• 25 Elsner, R. F., & Lamb, F. K., 1977, ApJ, 215, 897
• Ertan(2018) Ertan, Ü. 2018, MNRAS, 479, L12
• 26 Farinelli, R., & Titarchuk, L., 2011, AAP, 525, A102
• 27 Garain, S. K., Ghosh, H., & Chakrabarti, S. K., 2014, MNRAS, 437, 1329
• Ghosh & Chakrabarti(2018) Ghosh, A., & Chakrabarti, S. K. 2018, MNRAS, 479, 1210
• 28 Ghosh, P., & Lamb, F. K., 1979, ApJ, 232, 259
• 29 Ghosh, P., & Lamb, F. K., 1979, ApJ, 234, 296
• 30 Ghosh, P., Lamb, F. K., & Pethick, C. J., 1977, ApJ, 217, 578
• 31 Giri, K., & Chakrabarti, S. K., 2013, MNRAS, 430, 2836
• Gügercinoǧlu & Alpar(2017) Gügercinoǧlu, E., & Alpar, M. A. 2017, MNRAS, 471, 4827
• 32 Haardt, F., & Maraschi, L., 1993, ApJ, 413, 507
• 33 Jonker, P. G., van der Klis, M., Wijnands, R., et al., 2000, ApJ, 537, 374
• 34 Jonker, P. G., Wijnands, R., van der Klis, M., et al., 1998, ApJl, 499, L191
• 35 Lamb, F. K., Shibazaki, N., Alpar, M. A., & Shaham, J., 1985, NAT, 317, 681
• 36 Lanzafame, G., Molteni, D., & Chakrabarti, S. K., 1998, MNRAS, 299, 799
• 37 Mauche, C. W., 2002, ApJ, 580, 423
• 38 Méndez, M., 2006, MNRAS, 371, 1925
• 39 Méndez, M., & van der Klis, M., 1999, ApJl, 517, L51
• 40 Méndez, M., van der Klis, M., van Paradijs, J., et al., 1997, ApJl, 485, L37
• 41 Méndez, M., van der Klis, M., Wijnands, R., et al., 1998, ApJl, 505, L23
• 42 Molteni, D., Acharya, K., Kuznetsov, O., Bisikalo, D., & Chakrabarti, S. K., 2001, ApJl, 563, L57
• 43 Molteni, D., Fauci, F., Gerardi, G., et al., 2001, Journal of Korean Astronomical Society, 34, 247
• 44 Molteni, D., Lanzafame, G., & Chakrabarti, S. K., 1994, ApJ, 425, 161
• 45 Molteni, D., Ryu, D., & Chakrabarti, S. K., 1996, ApJ, 470, 460
• 46 Molteni, D., Sponholz, H., & Chakrabarti, S. K., 1996, ApJ, 457, 805
• 47 Monaghan, J. J., 1985, Computer Physics Reports, 3, 71
• 48 Monaghan, J. J., 1992, ARAA, 30, 543
• 49 Mondal, S., Debnath, D., & Chakrabarti, S. K., 2014, ApJ, 786, 4
• 50 Muno, M. P., Remillard, R. A., & Chakrabarty, D., 2002, ApJl, 568, L35
• 51 Paczynski, B., 1987, NAT, 327, 303
• 52 Paczyńsky, B., & Wiita, P. J., 1980, AAP, 88, 23
• 53 Paizis, A., Farinelli, R., Titarchuk, L., et al., 2006, AAP, 459, 187
• 54 Priedhorsky, W., Hasinger, G., Lewin, W. H. G., et al., 1986, ApJl, 306, L91
• 55 Psaltis, D., Belloni, T., & van der Klis, M., 1999, ApJ, 520, 262
• Revnivtsev & Mereghetti(2015) Revnivtsev, M., & Mereghetti, S. 2015, SSRv, 191, 293
• 56 Ryu, D., Chakrabarti, S. K., & Molteni, D., 1997, ApJ, 474, 378
• Sanna et al.(2017) Sanna, A., Riggio, A., Burderi, L., et al. 2017, MNRAS, 469, 2
• 57 Seifina, E., & Titarchuk, L., 2011, ApJ, 738, 128
• 58 Seifina, E., & Titarchuk, L., 2012, ApJ, 747, 99
• 59 Seifina, E., Titarchuk, L., & Frontera, F., 2013, ApJ, 766, 63
• 60 Seifina, E., Titarchuk, L., & Shaposhnikov, N., 2016, ApJ, 821, 23
• 61 Seifina, E., Titarchuk, L., Shrader, C., & Shaposhnikov, N., 2015, ApJ, 808, 142
• 62 Shakura, N. I., & Sunyaev, R. A., 1973, AAP, 24, 337
• 63 Smith, D. M., Heindl, W. A., Markwardt, C. B., & Swank, J. H., 2001, ApJl, 554, L41
• 64 Smith, D. M., Heindl, W. A., & Swank, J. H., 2002, ApJ, 569, 362
• 65 Strohmayer, T. E., Zhang, W., Swank, J. H., et al., 1996, ApJl, 469, L9
• 66 Sunyaev, R. A., & Titarchuk, L. G., 1980, AAP, 86, 121
• 67 Sunyaev, R. A., & Titarchuk, L. G., 1985, AAP, 143, 374
• 68 Sunyaev, R. A., & Truemper, J., 1979, NAT, 279, 506
• 69 Titarchuk, L., Lapidus, I., & Muslimov, A., 1998, ApJ, 499, 315
• 70 Titarchuk, L., & Osherovich, V., 1999, ApJl, 518, L95
• 71 Titarchuk, L., Osherovich, V., & Kuznetsov, S., 1999, ApJl, 525, L129
• 72 Titarchuk, L., Seifina, E., & Frontera, F., 2013, ApJ, 767, 160
• 73 Titarchuk, L., Seifina, E., & Shrader, C., 2014, ApJ, 789, 98
• 74 Vacondio, R., Rogers, B. D., Stansby, P. K., Mignosa, P., & Feldman, J., 2013, Computer Methods in Applied Mechanics and Engineering, 256, 132
• 75 van der Klis, M., Hasinger, G., Damen, E., et al., 1990, ApJl, 360, L19
• 76 van der Klis, M., Jansen, F., van Paradijs, J., et al., 1985, NAT, 316, 225
• 77 van der Klis, M., Wijnands, R. A. D., Horne, K., & Chen, W., 1997, ApJl, 481, L97
• 78 Wang, J., 2016, International Journal of Astronomy and Astrophysics, 6, 82
• 79 Wang, J., Chang, H.-K., & Liu, C.-Y., 2012, AAP, 547, A74
• 80 Wijnands, R., Homan, J., van der Klis, M., et al., 1997, ApJl, 490, L157
• 81 Wijnands, R., Homan, J., van der Klis, M., et al., 1998, ApJl, 493, L87
• 82 Wijnands, R., Méndez, M., van der Klis, M., et al., 1998, ApJl, 504, L35
• 83 Wijnands, R., van der Klis, M., Homan, J., et al., 2003, NAT, 424, 44
• 84 Yu, W., van der Klis, M., & Jonker, P. G., 2001, ApJl, 559, L29
• 85 Zdziarski, A. A., Lubiński, P., Gilfanov, M., & Revnivtsev, M., 2003, MNRAS, 342, 355
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https://www.lesswrong.com/posts/duAkuSqJhGDcfMaTA/reflection-in-probabilistic-logic | # 67
Paul Christiano has devised a new fundamental approach to the "Löb Problem" wherein Löb's Theorem seems to pose an obstacle to AIs building successor AIs, or adopting successor versions of their own code, that trust the same amount of mathematics as the original. (I am currently writing up a more thorough description of the question this preliminary technical report is working on answering. For now the main online description is in a quick Summit talk I gave. See also Benja Fallenstein's description of the problem in the course of presenting a different angle of attack. Roughly the problem is that mathematical systems can only prove the soundness of, aka 'trust', weaker mathematical systems. If you try to write out an exact description of how AIs would build their successors or successor versions of their code in the most obvious way, it looks like the mathematical strength of the proof system would tend to be stepped down each time, which is undesirable.)
Paul Christiano's approach is inspired by the idea that whereof one cannot prove or disprove, thereof one must assign probabilities: and that although no mathematical system can contain its own truth predicate, a mathematical system might be able to contain a reflectively consistent probability predicate. In particular, it looks like we can have:
∀a, b: (a < P(φ) < b) ⇒ P(a < P('φ') < b) = 1
∀a, b: P(a ≤ P('φ') ≤ b) > 0 ⇒ a ≤ P(φ) ≤ b
Suppose I present you with the human and probabilistic version of a Gödel sentence, the Whitely sentence "You assign this statement a probability less than 30%." If you disbelieve this statement, it is true. If you believe it, it is false. If you assign 30% probability to it, it is false. If you assign 29% probability to it, it is true.
Paul's approach resolves this problem by restricting your belief about your own probability assignment to within epsilon of 30% for any epsilon. So Paul's approach replies, "Well, I assign almost exactly 30% probability to that statement - maybe a little more, maybe a little less - in fact I think there's about a 30% chance that I'm a tiny bit under 0.3 probability and a 70% chance that I'm a tiny bit over 0.3 probability." A standard fixed-point theorem then implies that a consistent assignment like this should exist. If asked if the probability is over 0.2999 or under 0.30001 you will reply with a definite yes.
We haven't yet worked out a walkthrough showing if/how this solves the Löb obstacle to self-modification, and the probabilistic theory itself is nonconstructive (we've shown that something like this should exist, but not how to compute it). Even so, a possible fundamental triumph over Tarski's theorem on the undefinability of truth and a number of standard Gödelian limitations is important news as math qua math, though work here is still in very preliminary stages. There are even whispers of unrestricted comprehension in a probabilistic version of set theory with ∀φ: ∃S: P(x ∈ S) = P(φ(x)), though this part is not in the preliminary report and is at even earlier stages and could easily not work out at all.
It seems important to remark on how this result was developed: Paul Christiano showed up with the idea (of consistent probabilistic reflection via a fixed-point theorem) to a week-long "math squad" (aka MIRI Workshop) with Marcello Herreshoff, Mihaly Barasz, and myself; then we all spent the next week proving that version after version of Paul's idea couldn't work or wouldn't yield self-modifying AI; until finally, a day after the workshop was supposed to end, it produced something that looked like it might work. If we hadn't been trying to solve this problem (with hope stemming from how it seemed like the sort of thing a reflective rational agent ought to be able to do somehow), this would be just another batch of impossibility results in the math literature. I remark on this because it may help demonstrate that Friendly AI is a productive approach to math qua math, which may aid some mathematician in becoming interested.
I further note that this does not mean the Löbian obstacle is resolved and no further work is required. Before we can conclude that we need a computably specified version of the theory plus a walkthrough for a self-modifying agent using it. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8270903825759888, "perplexity": 1375.9432638928042}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-51/segments/1575541307813.73/warc/CC-MAIN-20191215094447-20191215122447-00275.warc.gz"} |
http://math.stackexchange.com/questions/149763/reals-edit-moreover-irrationals-s-r-that-do-not-satisfy-exists-q-p-in-m | # Reals (edit: moreover irrationals) $s,r$ that do not satisfy $\exists q,p \in \mathbb{Q}$ such that $s = qr + p$
I'm trying to understand the equivalence relation given in this question about quasi-interactive proof on real numbers. My guess is that the asker already knows that $\forall s,r \in \mathbb{R}, \exists q,p \in \mathbb{Q}$ such that $s = qr + p$ is not true. Is that the right interpretation? If so, how do you prove that?
-
Note that if the statement were true, then by fixing an $r$, we could conclude that the set of reals is countable. – David Mitra May 25 '12 at 18:58
That isn't what the asker is claiming--rather, that the given stepwise procedure will not (in finitely-many steps) show that the given $r,s$ are non-equivalent reals. Of course, if it were always true that for any such $r,s$ there existed such $p,q$, then the asker's claim would be completely false! Thus, that there exist $r,s$ with $r\neq_Q s$ is a necessary condition for the asker's claim.
You probably understand that "$s=_Q r$ iff $\exists p,q\in\mathbb{Q}$, $q\neq 0$ such that $s=qr+p$" defines a reflexive, symmetric, transitive relation on the reals. Thus, the reals are split into equivalency classes, modulo $=_Q$. It is trivial to note that if $s,r$ are rational, then $s=_Qr$. The answers given by Marvis and Jackson Walters demonstrate that there are multiple different equivalency classes.
-
Awesome, thanks! – idonutunderstand May 25 '12 at 20:13
If you are looking for irrational numbers $s$ and $r$, then $s=\sqrt{3}$ and $r= \sqrt{2}$ would do the job. You can check this by squaring both sides to get a contradiction that $\sqrt{2}$ is rational.
In general, if you are looking for irrational numbers $s$ and $r$, then
$$s=\sqrt{m} \text{ and }r = \sqrt{n} \text{ where } m,n \in \mathbb{Z}^+ \backslash{\{\text{ Square integers}\}} \text{ and } \sqrt{\dfrac{m}{n}} \notin \mathbb{Q}$$
The above is just one class of such pairs. You can construct infinite such classes.
-
@CameronBuie Yes:) ofcourse. Have changed it. – user17762 May 25 '12 at 18:53
what does $\mathbb{Z} \backslash{\{\text{ Square numbers}\}}$ mean? – idonutunderstand May 25 '12 at 19:28
@AbstractionOfMe I wanted to mean positive integers that are not squares i.e. the set $\{2,3,5,6,7,8,10,11,12,13,14,15,17,18,19,20, \ldots\}$. This is to ensure that $\sqrt{m}$ and $\sqrt{n}$ are irrational numbers. – user17762 May 25 '12 at 19:31
$s=\pi$ and $r=1$. Then $\pi$ would be a sum of two rationals which is rational.
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Hint $\rm\: s\in r\:\mathbb Q + \mathbb Q \subset\mathbb Q(r)\:$ is false if $\rm\:r\:$ is algebraic and $\rm\:s\:$ is transcendental over $\mathbb Q,\:$ or if they are quadratic numbers from different quadratic fields (i.e. different discriminants), etc.
- | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8319017291069031, "perplexity": 257.84433879149606}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-48/segments/1448398461132.22/warc/CC-MAIN-20151124205421-00285-ip-10-71-132-137.ec2.internal.warc.gz"} |
https://www.jiskha.com/questions/1446092/Let-A-2-3-be-a-fixed-point-A-point-P-moves-such-that-PA-is-equal-to-the-distance | # Math
Let A(2,3) be a fixed point. A point P moves such that PA is equal to the distance of P from the y-axis. Find the equation of the locus of P
PA2 = (x-x1)^2 + (y-y1)^2 +???
= (x-2)^2 + (y-3)^2 +???
I tried solving it using the distance formula but I'm still confused because I am given only one point A (2,3) coordinate. I searched all blogs on google but couldn't find a solved problem similar to this. Please help!
1. Ths distance of (x,y) from the y-axis is just x. So,
√((x-2)^2 + (y-3)^2) = x
(x-2)^2 + (y-3)^2 = x^2
x^2-4x+4 + (y-3)^2 = x^2
(y-3)^2 = 4x-4
(y-3)^2 = 4(x-1)
as I showed using the properties of parabolas
posted by Steve
## Similar Questions
1. ### Math
Let A(2,3) be a fixed point. A point P moves such that PA is equal to the distance of P from the y-axis. Find the equation of the locus of P PA2 = (x-x1)2 + (y-y1)2 +??? = (x-2)2 + (y-3)2 +??? I tried solving it using the distance
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A point Y moves such that its distance from point B (1,2) is constant. Given that x=k is the tangent of the locus of Y , express the equation of the locus in terms of k.
6. ### Analytic Geometry
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A point moves such that its distance from point A(1,0) is twice its distance from B(-2,0).Find the equation of the locus of the point.
8. ### math
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9. ### math
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More Similar Questions | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8531595468521118, "perplexity": 601.7786105442237}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 5, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-34/segments/1534221213691.59/warc/CC-MAIN-20180818154147-20180818174147-00235.warc.gz"} |
https://vsoch.github.io/2008/simplify-life-by-not-thinking-about-things-the-value-of-social-ignorance/ | I have a good friend that I often share the finest details of my analysis of people, behavior, and the social world. I throw a huge, ugly spittooee of thinking at him, reach the limits of my analysis and then the fatal moment when I’ve analyzed everything, have a huge amount of information, no idea what to do with it, and then wait for him to wipe my cognizant sneeze off of his eyes, and then I ask, “well what should I do?” And he’s told me this many times before, it’s what I come to expect, but until recently I didn’t realize what good advice it was.
“V, stop thinking”
”!@$##@#$##!! (insert squirmy-ness here) that’s like telling me to stop breathing! it’s not possible!” But when I thought about it (haha) I realized what good advice this is when you think about relationships. I think that it is more appropriate for romantic and friendship type relationships and less so family, but here is my idea.
A lot of college kids are frustrated by the absence of a deep relationships, whether that be friendship or romance, I’m sure it could be one or the other, both, or even vary by the day. In this frustration they (we) ask questions like “what is wrong with me, what is wrong with this environment so i don’t have what I think it is that I want, or deserve, and what do I have to do to get it?” Then we stumble back and forth between vows of pro-active behavior, bouts of self pity, and blaming. In the best times, I realize, I’m just distracted from thinking about it at all. Wait, in the best times I’m not thinking about it at all? So in whatever I am doing, I see a pattern of being most content when I’m not aware of my social-ness or lack of i it?? Rewind!
So how do we evaluate our relationships, how do we know where to put energy, where to hold back, and how do we evaluate ourselves as members of a social network? The answer is so much simpler than I thought possible – just relax and stop thinking about it. I know, it’s not the most satisfactory answer, but hear me out.
There are many ways you might be attracted to a person, and when I say attraction I am referring to those things that make someone else interesting, and ultimately compel us to engage them. When I think of an ideal friend, partner, running buddy, I’m pretty sure that my ideals aren’t founded on anything deeper than “well we share these interests, he’s a nice looking guy, he is similar to me,” etc. Those are really products of the retrospectoscope – us attempting to put a label on something after the fact that we probably don’t understand at all. I’m not even sure that I am capable of telling you what lets conversation flow comfortably and naturally between me and another person, or makes me want to spend time with them, and seek them out. What it comes down to is the idea that “good” relationships cannot be looked for, grown, forced, or predicted. We are going to put energy and time into people that we like to be around, that make us feel good, that we have a good dynamic with, really without thinking much about it. And if you stumble upon a two way street, you’ve probably hit gold. But in the most enduring (best?) relationships, no matter what the type, we get something out of interacting with the other person, and that positive something that we get lasts over time. And given that dynamics and people change, this something can also be lost, and that can lead to distress or despair, and confusion. But there isn’t much benefit of analyzing the black box that is this dynamic, trying to label incentives, track them, and do what I do way too much, over-think many of my relationships that aren’t the way I want them to be, and ask why.
Because you largely can’t answer that question, and more importantly, you don’t need to. The beautiful thing about this idea is the realization that it’s OK to not have yet found the other person, or other people, either friend or lover or confidant or running buddy, that might complement, complete, or fulfill you. Don’t jump to concussions, it doesn’t mean anything about you. But complete is a dangerous word, because with people, two incomplete people do not constitute a whole person. And this is exactly why it is best to focus on seeking personal fulfillment, whatever that means for you. And in pursuing what makes you happy, you will most certainly experience many types of relationships, learn from them, and hopefully find some rare sapphires.
So I started this thought by saying “just stop thinking,” but I think it’s important to still be aware- be aware of yourself, be aware of people that are directing energy toward you that you don’t know much about at all, aware of keeping in checks with dynamics that you do value, and be aware of the bases that found your relationships. This is another beautiful metaphor – the idea that friendships can be looked at like structures. Built on the wrong base, perhaps just for social purposes and lacking compassion and a connection with one another, is like trying to build a tower in a sand pit. Adding floors to that tower will be very challenging, as well as finding structural stability. This is an interesting conversation I had with another friend, actually about the dynamics of conversation. Look at trends in conversation over time, and ask if one person is simply filling in gaps with an occasional “cool, yeah, lol” when it is appropriate, and essentially adding nothing to the other person’s monologue, or does that person feel fed by what the other person has to say, and want to add something, respond, or challenge? It’s easier to evaluate yourself as a responder, listener, and contributor, than the other person, I think. So it’s interesting to think about what differentiates a rich conversation from one person telling things to another, and thinking that person is paying attention because he/she is responding at the appropriate time.
So it seems like there is a huge component of personal awareness, learning to abolish expectations, and as a result, find patience through your passions.
Time to listen to my own advice, mostly because it’s been a long week, and I haven’t done any work that I’m “supposed” to do | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.23648247122764587, "perplexity": 777.5346365400433}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-05/segments/1642320303729.69/warc/CC-MAIN-20220122012907-20220122042907-00073.warc.gz"} |
http://wiki.stat.ucla.edu/socr/index.php?title=SOCR_EduMaterials_Activities_ApplicationsActivities_BlackScholesOptionPricing&diff=prev&oldid=7935 | # SOCR EduMaterials Activities ApplicationsActivities BlackScholesOptionPricing
(Difference between revisions)
Revision as of 15:52, 3 August 2008 (view source)Nchristo (Talk | contribs)← Older edit Revision as of 15:52, 3 August 2008 (view source)Nchristo (Talk | contribs) Newer edit → Line 29: Line 29: the number of periods $n$ is large. In the example below we value the call option using the binomial formula for different values of $n$ and also using the Black-Scholes formula. We then plot the value of the call (from binomial) against the number of periods $n$. The value of the the number of periods $n$ is large. In the example below we value the call option using the binomial formula for different values of $n$ and also using the Black-Scholes formula. We then plot the value of the call (from binomial) against the number of periods $n$. The value of the call using Black-Scholes remains the same regardless of $n$. The data used for this example are: call using Black-Scholes remains the same regardless of $n$. The data used for this example are: - $S_0=\30$, $E=\29$, $R_f=0.05$, $sigma=0.30$, + $S_0=\30$, $E=\29$, $R_f=0.05$, $\sigma=0.30$, $\mbox{Days to expiration}=40$.
$\mbox{Days to expiration}=40$.
* For the binomial option pricing calculations we divided the 40 days into intervals from 1 to 100 (by 1). * For the binomial option pricing calculations we divided the 40 days into intervals from 1 to 100 (by 1). * The snapshot below from the SOCR Black Scholes Option Pricing model applet shows the path of the stock. * The snapshot below from the SOCR Black Scholes Option Pricing model applet shows the path of the stock.
## Black-Scholes option pricing model - Convergence of binomial
• Black-Scholes option pricing formula:
The value C < math > ofaEuropeancalloptionattime < math > t = 0 is: $C=S_0 \Phi (d_1) - \frac{E}{e^{rt}} \Phi(d_2)$
$d_1=\frac{ln(\frac{S_0}{E})+(r+\frac{1}{2} \sigma^2)t} {\sigma \sqrt{t}}$
$d_2=\frac{ln(\frac{S_0}{E})+(r-\frac{1}{2} \sigma^2)t} {\sigma \sqrt{t}}=d_1-\sigma \sqrt{t}$
Where,
S0 Price of the stock at time t = 0
E Exercise price at expiration
r Continuously compounded risk-free interest
σ Annual standard deviation of the returns of the stock
t Time to expiration in years
Φ(di) Cumulative probability at di of the standard normal distribution N(0,1)
• Binomial convergence to Black-Scholes option pricing formula:
The binomial formula converges to the Black-Scholes formula when the number of periods n is large. In the example below we value the call option using the binomial formula for different values of n and also using the Black-Scholes formula. We then plot the value of the call (from binomial) against the number of periods n. The value of the call using Black-Scholes remains the same regardless of n. The data used for this example are: $S_0=\30$, $E=\29$, Rf = 0.05, σ = 0.30, Days to expiration = 40.
• For the binomial option pricing calculations we divided the 40 days into intervals from 1 to 100 (by 1).
• The snapshot below from the SOCR Black Scholes Option Pricing model applet shows the path of the stock. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 5, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8722288012504578, "perplexity": 1149.0535102801975}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-40/segments/1600400189928.2/warc/CC-MAIN-20200919013135-20200919043135-00538.warc.gz"} |
https://fr.mathworks.com/help/autoblks/ref/automatedmanualtransmission.html | Documentation
Automated Manual Transmission
Ideal automated manual transmission
• Library:
• Powertrain Blockset / Transmission / Transmission Systems
Description
The Automated Manual Transmission block implements an ideal automated transmission (AMT). An AMT is a manual transmission with additional actuators and an electronic control unit (ECU) to regulate clutch and gear selection based on commands from a controller. The number of gears is specified via an integer vector with corresponding gear ratios, inertias, viscous damping, and efficiency factors. The clutch and synchronization engagement rates are linear and adjustable.
Use the block for:
• Power and torque capacity sizing
• Determining gear ratio impact on fuel economy and performance
To determine the rotational drive shaft speed and reaction torque, the Automated Manual Transmission block calculates:
• Clutch lock-up and clutch friction
• Locked rotational dynamics
• Unlocked rotational dynamics
To specify the block efficiency calculation, for Efficiency factors, select either of these options.
SettingBlock Implementation
`Gear only`
Efficiency determined from a 1D lookup table that is a function of the gear.
`Gear, input torque, input speed, and temperature`
Efficiency determined from a 4D lookup table that is a function of:
• Gear
• Input torque
• Input speed
• Oil temperature
Clutch Control
The AMT delivers drive shaft torque continuously by controlling the pressure signals from the clutch. If you select Control type parameter `Ideal integrated controller`, the block generates idealized clutch pressure signals. To use your own clutch control signals, select Control type parameter ```External control```.
Clutch Lock-Up and Clutch Friction
Based on the clutch lock-up condition, the block implements one of these friction models.
IfClutch ConditionFriction Model
$\begin{array}{l}{\omega }_{i}\ne N{\omega }_{d}\\ \text{or}\\ {T}_{S}<|{T}_{f}-N{w}_{i}{b}_{i}|\end{array}$Unlocked$\begin{array}{l}{T}_{f}={T}_{k}\\ \text{where,}\\ {T}_{k}={F}_{c}{R}_{eff}{\mu }_{k}\mathrm{tanh}\left[4\left(\frac{{w}_{i}}{N}-{w}_{d}\right)\right]\\ {T}_{s}={F}_{c}{R}_{eff}{\mu }_{s}\\ {R}_{eff}=\frac{2\left({R}_{o}{}^{3}-{R}_{i}{}^{3}\right)}{3\left({R}_{o}{}^{2}-{R}_{i}{}^{2}\right)}\end{array}$
$\begin{array}{l}{\omega }_{i}=N{\omega }_{t}\\ \text{and}\\ {T}_{S}\ge |{T}_{f}-N{b}_{i}{\omega }_{i}|\end{array}$Locked
Tf = Ts
The equations use these variables.
ωt Output drive shaft speed ωi Input drive shaft speed ωd Drive shaft speed ${b}_{i}$ Viscous damping Fc Applied clutch force N Engaged gear ${T}_{f}$ Frictional torque ${T}_{k}$ Kinetic frictional torque ${T}_{s}$ Static frictional torque ${R}_{eff}$ Effective clutch radius ${R}_{o}$ Annular disk outer radius ${R}_{i}$ Annular disk inner radius μs Coefficient of static friction μk Coefficient of kinetic friction
Locked Rotational Dynamics
To model the rotational dynamics when the clutch is locked, the block implements these equations.
`$\begin{array}{l}{\stackrel{˙}{\omega }}_{d}{J}_{N}={\eta }_{N}{T}_{d}-\frac{{\omega }_{i}}{N}{b}_{N}+N{T}_{i}\\ {\omega }_{i}=N{\omega }_{d}\end{array}$`
The block determines the input torque, Ti, through differentiation.
The equations use these variables.
ωi Input drive shaft speed ωd Drive shaft speed N Engaged gear bN Engaged gear viscous damping JN Engaged gear inertia ηN Engaged gear efficiency Td Drive shaft torque Ti Applied input torque
Unlocked Rotational Dynamics
To model the rotational dynamics when the clutch is unlocked, the block implements this equation.
`${\stackrel{˙}{\omega }}_{d}{J}_{N}=N{T}_{f}-{\omega }_{d}{b}_{N}+{T}_{d}$`
where:
ωd Drive shaft speed N Engaged gear bN Engaged gear viscous damping JN Engaged gear inertia Td Drive shaft torque Ti Applied input torque
Power Accounting
For the power accounting, the block implements these equations.
Bus Signal DescriptionVariableEquations
`PwrInfo`
`PwrTrnsfrd` — Power transferred between blocks
• Positive signals indicate flow into block
• Negative signals indicate flow out of block
`PwrEng`
Engine power
Peng
${\omega }_{i}{T}_{i}$
`PwrDiffrntl`
Differential power
Pdiff
${\omega }_{d}{T}_{d}$
`PwrNotTrnsfrd` — Power crossing the block boundary, but not transferred
• Positive signals indicate an input
• Negative signals indicate a loss
`PwrEffLoss`
Mechanical power loss
Peffloss
${\omega }_{d}{T}_{d}\left({\eta }_{N}-1\right)$
`PwrDampLoss`
Mechanical damping loss
Pdamploss
`PwrCltchLoss`
Clutch power loss
Pmech
When locked: $0$
When unlocked: $-{T}_{k}\left({\omega }_{i}-N{\omega }_{d}\right)$
`PwrStored` — Stored energy rate of change
• Positive signals indicate an increase
• Negative signals indicate a decrease
`PwrStoredTrans`
Rate change in rotational kinetic energy
Pstr
When locked: ${\stackrel{˙}{\omega }}_{i}{\omega }_{i}\left({J}_{in}+\frac{{J}_{N}}{{N}^{2}}\right)$
When unlocked: ${J}_{in}{\stackrel{˙}{\omega }}_{i}{\omega }_{i}+{J}_{N}{\stackrel{˙}{\omega }}_{d}{\omega }_{d}$
The equations use these variables.
bN Engaged gear viscous damping JN Engaged gear rotational inertia Jin Flywheel rotational inertia ηN Engaged gear efficiency N Engaged gear ratio Ti Applied input torque, typically from the engine crankshaft or dual mass flywheel damper Td Applied load torque, typically from the differential or drive shaft ωd Initial input drive shaft rotational velocity ωi, ώi Applied drive shaft angular speed and acceleration
Ports
Input
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Integer value of gear number to engage.
Clutch pressure command.
Dependencies
To create this port, select Control type parameter `External control`.
Applied input torque, Ti, typically from the engine crankshaft or dual mass flywheel damper, in N·m.
Applied load torque, Td, typically from the differential or driveshaft, in N·m.
Oil temperature, in K. To determine the efficiency, the block uses a 4D lookup table that is a function of:
• Gear
• Input torque
• Input speed
• Oil temperature
Dependencies
To create this port, set Efficiency factors to ```Gear, input torque, input speed, and temperature```.
Output
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Bus signal contains these block calculations.
SignalDescriptionVariableUnits
`Eng`
`EngTrq`
Input applied torque
Ti
N·m
`EngSpd`
Input drive shaft speed
ωi
`Diff`
`DiffTrq`
Output drive shaft torque
Tt
N·m
`DiffSpd`
Output drive shaft speed
ωt
`Cltch`
`CltchForce`
Applied clutch force
Fc
N
`CltchLocked`
Clutch lock status, Boolean:
• Locked — `0`
• Unlocked — `1`
N/A
N/A
`Trans`
`TransSpdRatio`
Speed ratio at time t
$\varphi \left(t\right)$
N/A
`TransEta`
Ratio of output power to input power
$\eta$
N/A
`TransGearCmd`
Commanded gear
Ncmd
N/A
`TransGear`
Engaged gear
N
N/A
`PwrInfo``PwrTrnsfrd`
`PwrEng`
Engine power
Peng
W
`PwrDiffrntl`
Differential power
Pdiff
W
`PwrNotTrnsfrd``PwrEffLoss`
Mechanical power loss
Peffloss
W
`PwrDampLoss`
Mechanical damping loss
Pdamploss
W
`PwrCltchLoss`
Clutch power loss
Pmech
W
`PwrStored``PwrStoredTrans`
Rate change in rotational kinetic energy
Pstr
W
Applied drive shaft angular speed input, ωi, in rad/s.
Drive shaft angular speed output, ωd, in rad/s.
Parameters
expand all
The AMT delivers drive shaft torque continuously by controlling the pressure signals from the clutch. If you select Control type parameter `Ideal integrated controller`, the block generates idealized clutch pressure signals. To use your own clutch control signals, select Control type parameter ```External control```.
Dependencies
This table summarizes the port configurations.
Control ModeCreates Ports
```External control```
`CltchCmd`
To specify the block efficiency calculation, for Efficiency factors, select either of these options.
SettingBlock Implementation
`Gear only`
Efficiency determined from a 1D lookup table that is a function of the gear.
`Gear, input torque, input speed, and temperature`
Efficiency determined from a 4D lookup table that is a function of:
• Gear
• Input torque
• Input speed
• Oil temperature
Dependencies
Setting Parameter ToEnables
`Gear only`
Efficiency vector, eta
```Gear, input torque, input speed, and temperature```
Efficiency torque breakpoints, Trq_bpts
Efficiency speed breakpoints, omega_bpts
Efficiency temperature breakpoints, Temp_bpts
Efficiency lookup table, eta_tbl
Transmission
Input shaft inertia, in kg·m^2.
Vector of integer gear commands used to specify the number of transmission speeds. Neutral gear is `0`. For example, you can set these parameter values.
To SpecifySet Gear number, G To
Four transmission speeds, including neutral`[0,1,2,3,4]`
Three transmission speeds, including neutral and reverse`[-1,0,1,2,3]`
Five transmission speeds, including neutral and reverse`[-1,0,1,2,3,4,5]`
Vector dimensions for the Gear number vector, Gear ratio vector, Transmission inertia vector, Transmission damping vector, and Efficiency vector parameters must be equal.
Torque breakpoints for efficiency table, in N·m.
Dependencies
To enable this parameter, set Efficiency factors to ```Gear, input torque, input speed, and temperature```.
Speed breakpoints for efficiency table, rad/s.
Dependencies
To enable this parameter, set Efficiency factors to ```Gear, input torque, input speed, and temperature```.
Temperature breakpoints for efficiency table, in K.
Dependencies
To enable this parameter, set Efficiency factors to ```Gear, input torque, input speed, and temperature```.
Vector of gear ratios (that is, input speed to output speed) with indices corresponding to the ratios specified in Gear number, G. For neutral, set the gear ratio to `1`. For example, you can set these parameter values.
To Specify Gear Ratios ForSet Gear number, G ToSet Gear ratio, N To
Four transmission speeds, including neutral`[0,1,2,3,4]``[1,4.47,2.47,1.47,1]`
Five transmission speeds, including neutral and reverse`[-1,0,1,2,3,4,5]``[-4.47,1,4.47,2.47,1.47,1,0.8]`
Vector dimensions for the Gear number vector, Gear ratio vector, Transmission inertia vector, Transmission damping vector, and Efficiency vector parameters must be equal.
Vector of gear rotational inertias, with indices corresponding to the inertias specified in Gear number, G, in kg·m^2. For example, you can set these parameter values.
To Specify Inertia ForSet Gear number, G ToSet Inertia, J To
Four gears, including neutral`[0,1,2,3,4]``[0.01,2.28,2.04,0.32,0.028]`
Inertia for five gears, including reverse and neutral`[-1,0,1,2,3,4,5]``[2.28,0.01,2.28,2.04,0.32,0.028,0.01]`
Vector dimensions for the Gear number vector, Gear ratio vector, Transmission inertia vector, Transmission damping vector, and Efficiency vector parameters must be equal.
Vector of gear viscous damping coefficients, with indices corresponding to the coefficients specified in Gear number, G, in N·m·s/rad. For example, you can set these parameter values.
To Specify Damping ForSet Gear number, G ToSet Damping, b To
Four gears, including neutral`[0,1,2,3,4]````[0.001,0.003,0.0025, 0.002,0.001]```
Five gears, including reverse and neutral`[-1,0,1,2,3,4,5]````[0.003,0.001,0.003, 0.0025,0.002,0.001,0.001]```
Vector dimensions for the Gear number vector, Gear ratio vector, Transmission inertia vector, Transmission damping vector, and Efficiency vector parameters must be equal.
Vector of gear mechanical efficiency, with indices corresponding to the efficiencies specified in Gear number, G. For example, you can set these parameter values.
To Specify Efficiency ForSet Gear number, G ToSet Efficiency, eta To
Four gears, including neutral`[0,1,2,3,4]``[0.9,0.9,0.9,0.9,0.95]`
Five gears, including reverse and neutral`[-1,0,1,2,3,4,5]````[0.9,0.9,0.9, 0.9,0.9,0.95,0.95]```
Vector dimensions for the Gear number vector, Gear ratio vector, Transmission inertia vector, Transmission damping vector, and Efficiency vector parameters must be equal.
Dependencies
To enable this parameter, set Efficiency factors to `Gear only`.
Table of gear mechanical efficiency, ηN as a function of gear, input torque, input speed, and temperature.
Dependencies
To enable this parameter, set Efficiency factors to ```Gear, input torque, input speed, and temperature```.
Transmission initial output rotational velocity, ωto, in rad/s. If you select Clutch initially locked, the block ignores the Initial output velocity, omega_o parameter value.
Initial gear to engage, Go.
Clutch and Synchronizer
Pressure input filter time constant, τc, in s.
Time required for gear selection and synchronization, ts, in s.
Time required to engage and disengage the clutch during shift events, tc, in s.
Dependencies
To create this parameter, select Control type parameter `Ideal integrated controller`.
The effective radius, ${R}_{eff}$, used with the applied clutch friction force to determine the friction force, in m. The effective radius is defined as:
`${R}_{eff}=\frac{2\left({R}_{o}{}^{3}-{R}_{i}{}^{3}\right)}{3\left({R}_{o}{}^{2}-{R}_{i}{}^{2}\right)}$`
The equation uses these variables.
${R}_{o}$ Annular disk outer radius ${R}_{i}$ Annular disk inner radius
Open loop lock-up clutch gain, Kc, in N.
Dimensionless clutch disc coefficient of static friction, μs.
Dimensionless clutch disc coefficient of kinetic friction, μk.
Select to lock clutch initially.
Dependencies
To create this parameter, select Control type parameter `Ideal integrated controller`.
Select to initially lock synchronizer.
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http://skinsvideos21.blogspot.com/ | ## martes, 21 de abril de 2015
### Sustainable Protein Sources
Cows are expensive.
Cow meat, in particular, is resource-intensive.
That’s what worries people who look at population growth trends. Meat needs a lot of resources to grow, specially cows and such. And global demand for beef will continue to increase as people climb out of poverty and seek more efficient sources of nutrition.
Someone on Quora asked about the cost of growing crickets compared to the cost of growing cows for beef, and this particular answer had some numbers.
Alex Drysdale, CEO of Changing What We Eat writes the following:
Crickets are approximate 20x more efficient overall as a food source compared to beef.
They grow 13 x faster (6wks vs 18m) than cattle,
on 2000 x less land (0.0125 acres vs 25 acres),
with 2000 x less water and 13 x less feed.
I wanted to find the equivalent amounts of each animal to produce the same protein, so I calculated a few things.
## How many crickets would it take to grow a cow’s beef worth of protein?
Disclaimer: I have not added sources to this, I just did quick Google searches for numbers that seemed reasonable and rounded extremely variable ones. I might add better sources in the future.
### How much protein does an average cow have?
Let’s take a big cow that reaches an adult weight of 680 kilos.
43% of the cow’s weight is meat for consumers. That is 292.4 kgs of beef.
1 kilogram of beef has an average of 154 grams of protein. (depending on the cut)
292.4 kgs of beef therefore contains 45 kilograms of protein.
This is, roughly, an estimate of what an average cow that weight would have.
### How many crickets does one need to produce 45 kgs (1 cow’s worth) of protein?
1 kilogram of crickets contains about 129 grams of protein.
Dividing that by 2.86, we know that there are 45 grams of protein in 349.6 grams of crickets.
45 - 349 600
4.5 - 34 960
0.45 - 3 496
0.045 - 349.6
Multiplying (4.5 x 10^-2) and 10^3, we get 45 kilos, and the corresponding amount of crickets needed to produce that is 349 kilos. That is a third of a tonne!
If an average 6-week old cricket (adult) weighs give or take 385 grams, it means that we need about 910 crickets to match the protein content of a cow’s worth of beef.
### How much water is needed to grow that cow versus all the crickets?
A cow, on a normal day might need about 26.5 litres of water, depending on temperature. On hot days it might need twice as much!
Over 77 weeks, which is the 18 months a cow takes to grow full-sized, this consumption amounts to 14 283.5 litres of water.
A cricket consumes about 2000 times less water than a cow, according to Drysdale above. This is about 0.0135 litres daily, or 13.5 mililitres (grams).
910 crickets, drinking 13.5 grams of dat H20 stuff amounts to 12 litres a day.
Over the course of 6 weeks, the time it takes for them to grow from pinheads to adult-sized crickets, this adds to 504 litres.
If we take Drysdale’s figure of a two-thousandth the water intake of a cow, but adjust for equivalent protein output, the more accurate number is a 1/28 the water input.
Let that sink in.
This means that in 7% it takes to raise a cow, and with 3.5% of the water used.
Our dependence on meats from vertebrates is a heavy burden on ecosystems and takes up a lot of energy, which drives currently a lot of emissions into the atmosphere. It contributes to droughts (I am looking at you, California), and it means land is cleared.
It also serves as a distraction. Who gives two monkeys’ if the beef is organic? Or freerange? Those points are on very shaky ground here. Seriously.
## sábado, 19 de julio de 2014
### A Critique of Vandana Shiva
Recently I came across this article, which has been getting a lot of attention on social media. I would like to bring to light its inconsistencies and faults.
# We Are the Soilby Vandana Shiva
'Creative work in being stewards of the land and co-creators of living soil is not an “input” into a food system, but the most important output of good farming,' writes Shiva. (Public domain)
We are made up of the same five elements — earth, water, fire, air and space — that constitute the Universe. [We’re already off to a bad start. Why bring up a medieval cosmology here? Isn’t matter and energy in spacetime good enough?] We are the soil. We are the earth. What we do to the soil, we do to ourselves. [This is the basic premise of the article and its title. The way we treat soil is linked to our health.] And it is no accident that the words “humus” and “humans” have the same roots. [This is interesting! The word “humus” comes from Latin, for earth or soil, from Indo European *dhghem—“earth”. Human, comes from Latin humanus, relating to human things, and seems to relate to the word homo, which interestingly might come from the same root, but with the sense of earthling; from earth.]
"The claim that the Green Revolution or genetic engineering feeds the world is false. [And again, another strawman argument. The idea that one single technology is the cure to all problems in the world is obviously impractical. Is organic the only solution? Not likely, for the same reasons. Like most intelligent approaches to complex issues, the answer relies on more than one solution.] Intrinsic to these technologies are monocultures based on chemical inputs, a recipe for killing the life of the soil." [Again with the death of the soil! Soil is hard to kill. First Vandana says that thinking that the assumption that soil is dead is false, then states that monoculture kills soil. Is it dead or not then? The author could look for more accurate ways of describing the effects of these chemicals too. On the other hand, it is true that monoculture systems have flaws. As other systems do too. The problem lies in picking the perfect context for a particular method of agriculture.]
History, however, is witness to the fact that the fate of societies and civilisations is intimately connected to how we treat the soil [For this very reason, we can hope that the collective knowledge of disasters and successes can further improve our current techniques, organic or not. Side question: was the Irish Potato Famine caused by chemicals, or just monoculture?] — do we relate to the soil through the Law of Return or through the Law of Exploitation and Extraction. [I admit that Vandana brings a fair ethical point about our relationship to the environment, where humanity must find a way of recycling its products back into the food chain and reduce the environmental impact. It is true that a lot of practices are not long-term sustainable, but
1: this is an area of constant research and development worthy of looking to, and
2: switching to preindustrial techniques (which might be what Vandana advocates), is not a serious solution either considering the number of people on Earth that need food and current land constraints.]
The Law of Return — of giving back — has ensured that societies create and maintain fertile soil and can be supported by living soil over thousands of years. [In terms of simple thermodynamics, the law of return is an equal input of energy into a system as the amount taken from it. In terms of soil, it means that the necessary nutrients that plants take from the soil be replenished for the next crop, which is what we do anyway. What we might be missing, which Vandana has so far not mentioned at all is the petrochemical industry.] The Law of Exploitation — of taking without giving back — has led to the collapse of civilisations. [Yes. And so have climate change, drought, war, pests, bad economics. Sometimes nature takes back regardless of whether you use chemicals in the soil or not.]
Contemporary societies across the world stand on the verge of collapse as soils are eroded, degraded, poisoned, buried under concrete and deprived of life. [If societies worldwide are about to collapse, it wouldn’t be because we are covering soil under concrete. Cities are high-density areas of human settlement, meaning that while in a spread-out fashion we might cover much more soil under concrete and roads, we can save more land for good use by moving in close to each other. And yes, yes, yes, industrial agriculture at its worst has detrimental effects on the environment, but not all of these effects are part of the industry she talks about. Some, for instance, are related to soon-to-be-obsolete industries such as coal-based energy and the automotive industry.] Industrial agriculture, based on a mechanistic paradigm and use of fossil fuels has created ignorance and blindness to the living processes that create a living soil. [This ignorance, apparently, is shared by certain activists who write that we are the soil and we are killing it. It shows poor understanding of the biology of the soil. Yes, schools should inculcate children on the composition of soil and all the microorganisms living in it, it is important. And again, YES, fossil fuel dependency is an issue. It would be great to commercialise renewable alternatives. This should not be a critique of a “mechanistic paradigm” but rather energy resources. Turning mechanism into a dirty word betrays ignorance: there is a large number of people on Earth. We want to feed them all. Mechanisms are designed to reduce waste and increase productivity. Avoiding these “paradigms” is like saying that we should not strive to be efficient. Why would one not want to be efficient? Should we be even more wasteful?] Instead of focusing on the Soil Food Web, it has been obsessed with external inputs of chemical fertilisers — what Sir Albert Howard called the NPK mentality. Biology and life have been replaced with chemistry. [Another misleading statement. A good biologist, and particularly botanologists worth their salt will assert that plants require more than just Nitrogen, Potassium and Phosphorous; that certain plants need certain minerals, and that NPK is outdated. Biology has not been replaced by chemistry, what is this nonsense? Proper understanding of both is needed. And of course certain plants grow on only certain soils.]
External inputs and mechanisation are imperative for monocultures. [Scary word mechanisation is scary. Unlike abused immigrant farmers picking strawberries by hand and breaking their backs, that is familiar and nice.] By exposing the soil to wind, sun and rain, monocultures expose the soil to erosion by wind and water. [Again, another strawman argument. Agriculture is a science that learns from past mistakes. No-tilling is actually practiced in response to soil runoff. Vandana implies that a whole science and a whole community of people do not adapt to changing circumstances to suit environmental and production needs. She also implies that other methods of agriculture are completely blame-free from exposing soil to erosion, therefore presenting the best of one side and the absolute worst from the other.]
Soils with low organic matter are also most easily eroded, since organic matter creates, aggregates and binds the soil. [Yes. And this is why one replenishes soils. Or grows plants in it. Or chooses not to till it.]
Soil is being lost at 10 to 40 times the rate at which it can be replenished naturally. This implies 30 per cent less food over the next 20-50 years. [This is a serious issue worth looking at more in the future. I would like sources for this claim. Is this globally? Incidentally, is this only in agricultural areas, or in general, as in through droughts and climate change? Does moving away from mechanistic agriculture to other methods necessarily imply that soil loss will decrease? Does mechanistic agriculture present workarounds to preserve soil integrity?] Soil erosion washes away soil nutrients. A tonne of top soil averages 1-6 kg of nitrogen, 1-3 kg of phosphorous, 2-30 kg of potassium, whereas soil in eroded land has only 0.1-0.5 per cent nitrogen. [Vandana just compared kg of substances per tonne of soil, with percentages in soil. These numbers mean nothing by themselves. If it means less, then how much less?] The cost of these nutrient losses are \$20 billion annually. [What does this number mean, compared to loss by other causes?]
"Soil, not oil, holds the future for humanity. [And the soil’s future relies on the sun, carbon, nitrogen, phosphorous, potassium, other minerals, water, and a plethora of biological processes.] The oil-based, fossil fuel intensive, chemical intensive, industrial agriculture has unleashed three processes which are killing the soil, and hence impacting our future." [This again.]
Fertile soils contain 100 tonnes of organic matter per ha. [I don’t understand this number, because an hectare is a unit of area, and does not tell me the volume of soil in that area.] Reduction of soil organic matter by 1.4-0.9 per cent lowers yield potential by 50 per cent. [Organic fertilisers exists for a reason.] Chemical monocultures also make soils more vulnerable to drought and further contribute to food insecurity. [This is a restatement of the previous paragraph. Is monoculture or polyculture really the one thing to blame? It is the tilling of land, which many have abandoned. It is climate change, which changes weather patterns. It is soil mismanagement. (Remember you said we must not control soil? Let it dry then and lose organic matter!)]
Further, eroded soils and soils without organic matter absorb 10 to 300 mm less water per ha per year from rainfall. This represents 7 to 44 per cent decrease in water availability for food production, contributing to a decline in biological productivity from 10-25 per cent. [Answer: put organic matter into it.]
No technology can claim to feed the world while it destroys the life in the soil by failing to feed it on the basis of the Law of Return. [Misleading. If we have designated a plot of land to grow food, our concern should be that it grows that food, and that the soil does not run off. And that we do not prevent future growth by putting toxins in it, which I infer is what Vandana implies, even if considerable research goes into finding eco-friendlier ways of managing soil.] This is why the claim that the Green Revolution or genetic engineering feeds the world is false. [A false claim, that one technology is the silver bullet to all problems, is false because while it actually helps feed people because Vandana feels that it somehow is not being replenished before we grow more. Or something like that? This straw man argument is dragging on... More meaningful would be to advocate for renewable alternatives to such industrial methods, right?Intrinsic to these technologies are monocultures based on chemical inputs, a recipe for killing the life of the soil and accelerating soil erosion and degradation. [I think I read this same sentence twice before already.Degraded and dead soils, soils without organic matter, soils without soil organisms, soils with no water holding capacity, create famines and a food crisis, they do not create food security. [Soil degradation is serious. It must be avoided, for it is wasteful and hard to fix. And any technology that can hopefully reverse this must be looked at seriously. Vandana: please!]
This is especially true in times of climate change. [Except when it isn’t true, such as previously unusable soils becoming fertile for food growth. Northern Canada and Siberia. Not that I think this is good, but it means that not all climate change “kills soils”.Not only is industrial agriculture responsible for 40 per cent of the Green House gases contributing to climate change, it is also more vulnerable to it. [YES!!!! Thank you for this important point. This is a pressing issue. And so is the percentage of carbon emissions due to concrete production, coal and petrol, and all sorts of other processes. Would Vandana support me if I went about installing solar panels and batteries on all the machinery used to grow crops, even the tractors and tillers? And solar panels on the factories creating the chemicals used to sustain high growth in soil?]
Soils with organic matter are more resilient to drought and climate extremes. [This is another repeated sentence. My attention span is not that short.And increasing organic matter production through biodiversity intensive systems, which are in effect photosynthesis intensive systems is the most effective way to get the carbon dioxide out of the atmosphere, into the plants, and then into the soil through the Law of Return. [Wait wait hold up! Biodiverse or not, photosynthesis still will happen where there are plants. Do you want to know what part of the planet might possibly best represent the Law of Return? The Midwest. NASA used fluorescent light from satellite imagery to create a detailed map of world photosynthetic levels and discovered that while tropical rainforests are the most productive year-round, the bloody Midwest, during the north’s harvesting season, is the brightest spot on earth, everything else paling in comparison.]
Soil, not oil, holds the future for humanity. [Repeat this mantra with me, again. Yes, oil is a primitive energy source, and if aliens saw us, they’d say we are very primitive, burning dead plants as a source of fuel. Come on already, Vandana, let’s keep the best of both worlds: mechanisation and efficiency, with sustainable resources!The oil-based, fossil fuel intensive, chemical intensive, industrial agriculture has unleashed three processes which are killing the soil, and hence impacting our future. [This sentence was lifted verbatim from a couple paragraphs above. Notice how she only lists two things below.]
Firstly, industrial agriculture destroys living soils through monocultures and chemicals. [Looking at this closely with the previous paragraph, it reads like: We are killing the soil in three ways. The first way is by killing it (with monoculture and chemicals). Circular argument. Second, an oil-based paradigm intensifies fossil fuel inputs and creates a false measure of productivity which presents an unproductive system as productive. [Let’s follow the logic here, statement by statement.
A: Fossil fuels are used.
B: Fossil fuel emissions go up.
So far this is logical.
C: This system creates a lot of food because of the energy we get out of nonrenewables allows us to.
D: High food production means systems are productive.
E: This system is not actually productive, because... it is not?
Merriam Webster says that unproductive means “producing inferior or only a small amount”, or “producing no results”.
So, these are possibilities:
1—Producing a lot of food, but undercounting it and thus perceiving inefficiency? I would argue this based on the (unrelated to this article) habit that people waste a lot of food.
2—We are actually producing very little food considering the amount of fossil fuels that go into making it. This is interesting, because as much as I’d love to see no more fossil fuels used, we could say that as long as we are using them, we might as well be as efficient and unwasteful as possible. So in effect, we are indeed presenting an “unproductive” system as productive.
3—Vandana is making a logical fallacy and I am trying my best to make sense of it and put it into a wider context.]
The trick lies in reducing creative productive work to “labour “ as a commodity, counting people as labour as an “input”, and not counting fossil fuels as an input. [Hard work in agriculture should be respected and paid its due. If this is commodifying it, then let it be. A lot of immigrants in the United States take up farming and it pays extremely low. I don’t know what point Vandana is trying to make. Fossil fuels are indeed counted as inputs. Where did she get the idea that they are not? For further info on fossil fuels in agri-industry, click here. This is worthy of examining.] Intensive fossil fuel use translates into more the 300 “energy slaves” that work invisibly behind each worker on fossil fuel intensive industrial farms. [What are these quote-unquote energy slaves? Since this article was about chemicals in the soil and I perceive this part to stray from Vandana’s central argument, let’s take the example of the chemical industry, from which farmers buy products. Where do these chemical industries get their products from, and who is a slave in the process? Very important question to look into, if it’s true; unfortunately it’s one sentence in what could have been a meaningful paragraph.]
People as an input means the less people on the land, the more “productive” agriculture becomes. [The less people working on anything, the more people can pursue bigger ideas and help others. What is your point, Vandana?] Farmers are destroyed, rural economies are destroyed, the land is emptied of people and filled with toxics. [This might be a bit luddite and hints at the idea that the farmers should remain confined to the land, that there must be more people working on preindustrial farmlands all day long. Toxics is not really a word in any case and by confusing all chemicals with toxic substances, the author shows weak understanding.] The creative work of farmers as custodians and renewers of soil and biodiversity is replaced by deadly chemicals. [I do not understand why there seems to be no middle ground, where farmers can use the latest knowledge, technology and experience from a worldwide pool of people to be the guardians of soil and biodiversity they want to be. This is a fallacy of the excluded middle.]
Creative work in being stewards of the land and co-creators of living soil is not an “input” into a food system, but the most important output of good farming. [The most important output of good farming is good food. Followed very closely by an intelligent and careful relationship with the environment. This talk of input and output hardly makes any sense. While it would be great that people bought a product such as a farmer intelligently managing the soil (business idea anyone?? A bit like Eco-Insurance or something?), what does it mean that it is not an input? What is then?] It cannot be reduced to “labour” as a commodity. [What is it then? If people want to pay for food, how is it not labour? What if a farmer decides to just grow food at his whim and without regards to what people around him/her need? “Nah man, I don’t work as a commodity. I don’t feel like making food today.” People need food, and the market will make sure it comes from somewhere, regardless of meaningless platitudes like “we cannot reduce it to a commodity”] Land, too, is not a commodity. [I agree that owning a piece of planet Earth is iffy and strange, but this is a philosophical point, and most human beings indeed treat land as a commodity. Saying it is not is like saying that people don’t treat it like so.] Creating, conserving, rejuvenating, fertile and living soil is the most important objective of civilisation. It is a regenerative output. [Civilisation 101: Learn the laws of thermodynamics.]
Third, displaced farmers flood cities. [And displaced factory workers flooded suburbs once.] This is not a natural or inevitable phenomenon. [Yes, and cities need better ways of integrating incoming people. It is a serious problem.] It is part of the design of industrial agriculture. The explosion of cities buries fertile soil under concrete. [Cities are some of the most dense settlements on Earth. What would a person who obviously wants the least amount of concrete burying good soil want? Cities.] The equivalent of 30 football fields are consumed by cement and concrete every minute. [I just realised that this is maybe an American problem. In other countries, cities are planned so that most important things are at reach. In the United States though, people have been living in sparse settlements so long that they assume it’s normal to build and build in the middle of nowhere.]
The Save our Soils (SOS) movement, of which I am a patron, has been started by many organisations including FAO, IFOAM, Nature and More, to wake humanity to the soil emergency, which is also a human emergency. [That is commendable. The author, however, should assume the role of responsibility if she really is patron of SOS. She should know what she is talking about, these are no light matters and the way she made her case in this article is iffy.]
We need to measure human progress not on the basis of how much cement buried the soil [Human progress is not measured that way, firstly. Roads and indoor floors are places where cement goes, but on the field? With crops? How is this even related to your point, Vandana?], but how much soil was reclaimed and liberated. [This is a good start, but no, not the soil liberation, but soil detoxification, and our ability to prevent soil runoff. And our ability to use technology wisely to keep feeding what will become 10 billion people. Not this stupid idea that concrete should be removed, maybe from inner city parts, to grow food in. That urban soil needs cleaning up beforehand anyway, with all the lead in it. THAT’S SERIOUS STUFF. This article misses great opportunities to make points like that.] This is what “saugandh mujhe is mitti ki” should mean. Living seeds and living soils are the foundation of living and lasting societies. [I just feel like I read a bunch of nothing, with fallacies used as icing. There is so much important stuff to talk about, and this article does little to address these issues.]
Dr. Vandana Shiva is a philosopher, environmental activist and eco feminist. She is the founder/director of Navdanya Research Foundation for Science, Technology, and Ecology. She is author of numerous books including, Soil Not Oil: Environmental Justice in an Age of Climate CrisisStolen Harvest: The Hijacking of the Global Food SupplyEarth Democracy: Justice, Sustainability, and Peace; and Staying Alive: Women, Ecology, and Development. Shiva has also served as an adviser to governments in India and abroad as well as NGOs, including the International Forum on Globalization, the Women’s Environment and Development Organization and the Third World Network. She has received numerous awards, including 1993 Right Livelihood Award (Alternative Nobel Prize) and the 2010 Sydney Peace Prize.
## viernes, 2 de noviembre de 2012
### The Light-Year Long Plank
A while back I stumbled across the following video, and the conundrum in it resurfaced in my thoughts later and I presented it to a few friends. It provided an interesting hour or two at the college cafeteria for discussion, and tons of disagreements.
One person in particular suggested the following:
The speed of the information traveling through the plank would approach the speed of light (c) as the bonds joining the atoms in the plank become 'stiffer', and if you had a completely rigid atomic structure, the plank's other end would move nearly instantaneously as the information traveled faster than light. The whole structure would move in unison if we reached complete stiffness, as there is no room for contraction waves and every particle moved at the same time.
The first part of this is correct as described in the following formula for the speed of sound:
$c = \sqrt{\frac{E}{\rho}}\,$E is a coefficient of stiffness, the bulk modulus (or the modulus of bulk elasticity for gases),
$\rho$ is the density(from Wikipedia)
The speed of sound decreases with density p and increases with bulk modulus (stiffness), which in solids is Y, Young's modulus.. The question then is, what is the highest that E can be?
The transfer of this movement through the plank is a pressure wave that moves the atoms within. When an atom is pushed, its electrons create a force against the electrons of the neighbouring atom, moving it and causing eventually the whole system to be displaced when the movement reaches the end of the plank. Diamond, the hardest bulk material known to man, has a speed of propagation of 1200 m/s, as opposed to air's speed of about 340. Diamond is not very elastic at all and it has the density of carbon. However, dealing with a theoretical material with total stiffness, we run into a problem.
### Faster than light or near instant?
Can infinitely high bulk modulus allow sound to surpass c, the speed of light? Is this property possible? Firstly, atoms have a limit on their bonds' rigidity; and there are reasons why infinite bulk modulus does not make sense.
A completely rigid system would mean that the initial atom would not be able to move in relation to the one next to it, with no relative change in distance between them, and no push exerted. This means all the energy would be absorbed and none would be transferred onto the next atom. Clearly this is a problem. It might seem counter-intuitive but the idea of completely stiff atomic bonds does not make sense since atoms need at least some degree of movement in order to act on nearby atoms.
$\sqrt{\infty /p} = undefined$The idea is a lazy one because it doesn't explain how atoms could transfer energy to each other. Infinite stiffness does not make sense and could allow one to decide its outcome as anything because it is undefined. Dividing infinity by a finite number and taking its square root will give you an undefined answer.
This model ignores the restrictions of our current model of the universe, and therefore the current model of the universe cannot tell us anything useful about it. Ok, so if instant movement does not make sense by definition, we need to consider the next issue issue: the possibility of information traveling faster than c, the speed of light. Tachyons are the only exception to this rule and as far as science has seen, yet they do not exist. Furthermore, other areas of astronomy can shed some light on this, as this passage I quote from here, about the largest theoretical size of neutron stars before they collapse into black holes:
Since the conditions in a neutron star are very difficult to duplicate on Earth, nobody is exactly sure just how big a neutron star can be. One indirect argument is based on the fact that as a neutron star becomes more massive, it must become stiffer to maintain itself, and the speed of sound through the star increases accordingly. Above six solar masses, the speed of sound exceeds that of light, which is ruled out by Einstein's theory of relativity.
Six solar masses is only an upper bound on the size of a neutron star. More practical calculations estimate the upper limit as three solar masses. No objects confirmed as neutron stars are known that are larger than two solar masses; the mass is typically about 1.35 solar masses.
### At the speed of light, or below?
Once we discard the possibility of faster-than-light sound-waves, one begins to wonder; what is the speed of a force? This might sound strange, but firstly, the energy is transferred from one end of the plank to the other through electromagnetic force that, as mentioned before, keeps atomic and subatomic particles apart. According to the standard model and the theory of relativity, forces travel at the speed of light, so the weak and strong nuclear forces, gravity and electromagnetism are not instantaneous as may be perceived in the small scales in which we might perceive them.
What is the maximum speed of sound? Theoretical and observed?
In the link above, the following possibilities are explored by some people:
• Plasma: matter in this state goes by slightly different mechanics, and bulk modulus would be the energy associated with electron degeneracy, and the guesstimated speed would reach about
500,000 m/s. (100 times slower than light).
• Neutron stars: electron degeneracy is followed by neutron degeneracy which makes matter collapse onto itself. This causes the bulk modulus to rise exponentially (as predicted by my friend). To quote the result:
"At that point, information from the center of the star can barely reach the edge, whether it's light or sound, so the local speed of sound at a neutron star just about to become a black hole would probably be just about light speed.
References: I used no references and I also don't know what I am talking about. Please do not substitute this answer for medical advice."
The distance the electromagnetic forces communicate movement through is not the space between the atoms (atoms are mostly empty space); it's the space between the electromagnetic fields of the electrons that interact with each other. That space is VERY CLOSE to a light year long in our experiment. The whole process of movement includes this space plus the distance particles (which can't be completely rigid) must travel to influence one another. In theory, as long as the formula used to calculate it does not provide undefined answers, none of the parameters stray off the current model of the universe we understand and the answer reaches c but isn't equal to it, there would be little reason to dismiss claims of the possibility that some materials may be able to transmit at almost such speeds. The best example I could find was in this following paper that concludes that evaluating equations at different densities for neutron stars all yield values for the speed of sound inferior to c.
Wait a minute! What about black holes?
Most of the theory before this deals with matter before it collapses into black holes. Most mathematical models explaining spacetime and force break down when they deal with black holes since they consist of matter that has collapsed further than a neutron star would have and has become so compressed it ceases to have actual volume. Despite my research I could not find much on the topic and the little I did points to the idea that a non-rotating black hole is completely stiff (has no adiabatic compressibility rate) while a rotating one has properties closer to neutron stars (see more: Compressibility of a Black Hole). While this tells us the possible properties of the matter in a black hole we have little idea (as far as I know) of how waves of sound would behave as they enter its event horizon or travel along its surface. A couple threads on StraightDope briefly touch this but it seems that sound doesn't travel at all because an infinitely compressible medium does not allow it to (as touched before when E becomes infinite in the speed of sound equation) or also because there is no space to travel the idea does not make sense.
Also, how would a plank-black hole structure be like?
Why is the elastic modulus relatively insensitive to changes in chemistry/heat treatment(...)
The Nature of Sound - The Physics Hyperbook
The Superluminal Scissors (similar Gedankenexperiment)
## sábado, 14 de enero de 2012
### New album for 2012
What perfect time to clear some cobwebs on this old blog than by announcing a new album?
What?!? That's right! I've been working on this one for a while, and now present you with:
Mainly a crossbreed of drum & bass, dubstep and breabeat with bits of rock, jazz, metal and other things showing up now and then.
Get your bass speakers on max!
With the exclusive performance of MC T-Tym.
## domingo, 25 de septiembre de 2011
There's probably no surprise to the idea that people who sell stuff on the streets of the Latin America are something common. I personally find it interesting how hawkers, peddlers, or however you want to call 'em are big parts of Latino culture, and so, it is interesting hearing songs about them in popular styles of music from several countries. So far I found songs from Mexico, Chile, Venezuela, and Paraguay, but I'm sure that if I dug a bit deeper I'd be able to find references to them in songs of just about every Hispanophone country. So, without further ado:
Oscar Padilla - El Tamalero (from Mexico)
Pedrito Altamiranda - El Buhonero (Panama)
Banda MS - Cacahuates Pistaches (Mexico)
Juana Fé - Callejero (Chile)
(this last one reminds me of Saturday Night Live with its air of parody).
## martes, 18 de enero de 2011
### 2010 Music Competition!
Towards the end of last year, I signed up to Boyinaband, some sort of magical place where you can find resources and tutorials and stuff on electronic music, and jokes. It just happened that there was a competition going on, courtesy of this guy here, so I decided to give it my best shot (although I only had 5 days left), so I began working on a track and although I didn't think it would win, it was all done with having fun in mind. Anyway, this was my entry:
Perhaps I shouldn't have gone wild with the entry and experimental but I was just having so much fun putting a dembow here, a 2-step drum & bass beat here, some chopped-up royalty-free funk samples there and a goddamn wobble bass smack in the middle and again after. And a hip hop interlude too. People who read this might be aware that I'm interested in merging d&b with more Latino rhythms (something that will show up in a future track too).
Anyway, I didn't win and it's okay. It was fun. I think the winners totally deserved their places and mentions, so here are the rest of the contestants (last three are the winners, leaving the best tracks for last (not saying the first ones are the worst though)).
(whoops, Sirena by Medik has dissapeared D:)
There are a few entries that received honourable mentions, like the gosh darn funky
Timothy Law Snider - Uncle Wiggly (there's a small playlist there but no way to embed the song)
and..
and also...
CHNK - Trance Chug (I couldn't find it anywhere... oh well)
Now, the finalists:
In third place, is this clever guy here who won't let me embed his :(
JKR ft. Bettina Reuterberg - Revolve
In second place, we have...
And the winner of the BoyinaBand competition is...
A banger I say!
It seems that the winners will get their tracks on a release by Housefly Records, that will be nice. Also, there's this double release with dubstep and drum & bass that was linked in BiaB, but I'm not sure why. It looks good though.
## miércoles, 29 de diciembre de 2010
### A Couple Reviews for my Album & Advice for Beginning Musicians
A problem with releasing my online CD, I found, was that getting feedback on it wasn't always easy until you specifically asked. Recently, I just went straight to the point on a post on DeviantArt and, hooray, a couple people gave me some wonderful, hilarious, silly or smart, very helpful or not comments. All of them brutally honest, as I asked them to. Down below I have selected some of the things that have been said, and, to be honest, I totally agree with the criticism I've been given. Reading these has helped me focus on what areas I need to improve and which are my strong points, so when I begin working on the next CD, I will know how to take my music as far as I can (well, at least a bit more, thank you all for commenting!)
So.. oh yeah, comments and reviews (by people I know and by total strangers):
this has to be one of the weirdest things I have heard all year. Congrats, you managed to combine annoying and boring in a completely new way.
– Morthax
very tight songwriting
it should sell
but I’m afraid its not poppy and simple enough
- ttwoo
Oh man, I think I'm sold. I'm not even halfway through the first track, either. Very nice!
– napalmpotato
First off, this music really isn't my thing, with that said, I enjoyed it for a bit...it was very creative.
The mix on your first track seems to be overdriven a bit, were you going for that? It was distracting.
I liked the MJ samples in Bricktop, I didn't like Itchy Bitchy Spider at all, but the mix was decent on those two songs.
I didn't bother listening to the rest because I had lost interest at the 3:30 mark of IBS after the solo (which was appetizing). Good work though
– Arkayem
love the first song, LOVE the drum quality
Lets a goin down remix is SOOO good
cept for the videogame metal
all amazing
videogame metal was a fail in my opinion
like how u mixed both michael jackson and old 40's jazz
[this] music is good study music
u sound like goofy in the daniel song
what the fuck were u thinking about when u wrote the lyrics?
love the break downs of the song song
Jamón Serrano is sooo good
I think I’m addicted [to it]
I just realized
Ur voice sounds like Sean Paul
Mixed with the singer of Rammstein”
I love the vocals for Crazy With the Hues
eni-mini-miny-mo, catch michael jackson by the toe??
– D. T.
from my point of view ur music is very complex and extended. i rlly like it that way. its enjoyable when i wander off and get into the music.
– B. T. (no, not the DJ)
Just checked out the first song - so far, it sounds nice. I would have mixed the drum/percussion samples a bit further back myself, might just be a matter of preference though (I'm a drummer, the beats got me air drumming :D I like snares in those nonstandard places)...
The beginning of the second song reminded me a bit of Autechre, always good as far as I'm concerned... I'll have a corn muffin or three or four and get to it and the others on a fuller stomach...
I'm on Any Day Today, which would, should, and absolutely wants to be a great song, maybe somewhere between Pink Floyd and Modest Mouse vibewise, tarnished greatly by too many effects on the vocals... your voice is solid, don't be afraid of your voice! Don't get in the way of the listener connecting with the most human and accessible part of the music! Some compressors on the vocals to control dynamics should be plenty...
The first two songs and the last three songs (especially Bricktop Breakbeat and Any Day Today) are solid, the album bogs down in the middle for lots of reasons - sometimes stuff repeated more than it had to (The Big Blue Eye), sometimes the distorted guitars were in serious need of mids and volume (Itchy Bitchy Spider), some songs just weren't up to par with the others at all (tracks 3 through 7)... the odd beats and folky Spanish-y (is a lot of that style from being in Chile? If so, awesome! :D if not, still awesome!) guitar style are your really strong points, and your voice sounds good with no effects (I wouldn't mind more vocals, actually)... while your at it, get or make an abstract painting and make that the new album art, the best of what you made deserves a better cover.
– woofwoofl
Get someone to mix that better.
- pyro-tom
Not sure what else to say. They're damn good songs.
- anonymous
Seriously, your music is probably the best stuff i've heard posted in these threads.
- anonymous
So, with all that said, I realise the follwing key points:
• While the music may be really different and original, the ordinary listener gets bored, specially because it repeats more than it should sometimes, or it's complicated.
• When I made the music, I was sorta reluctant to include vocals because... I'm shy 'bout it. I know that by masking the vocals under tons of effects and crap I was probably losing my chance to connect with the listener (The human voice is the most versatile of instruments, and yet, I don't exactly feel comfortable using it... I'll practice more!)
• The mixing, in general, is crap. I'm sure that if I did it now, it would be a lot better, but hey, I'm surprised that what sounded okay-to-acceptable back in October sounds grating on my ears now at the end of December. I guess I got my game on after working on it...
• Now, am I making something so that it becomes a pop hit, or am I making 'extended' music that delves into progressive grounds, for me to explore? I think I'll take the arduous path, discovering 'experimental party/pop/ music'. Hmmm, how might that work?
I recommend all starting musician to do this... I'm not exactly a beginner but I'm not an expert or a very experienced musician either, so this kinda stuff helps me understand better how other people might hear what I make and what they think and feel about it. My problem sometimes (as might be with a lot of beginners and well, lots of people), is that I tend to criticise my own work and always think it's not good at all or stuff like that. So, I'll keep improving and on the way I'll ask for feedback. And that's one way to grow. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 2, "codecogs_latex": 1, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.37905436754226685, "perplexity": 1967.4030722417417}, "config": {"markdown_headings": true, "markdown_code": false, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-18/segments/1429246659449.65/warc/CC-MAIN-20150417045739-00155-ip-10-235-10-82.ec2.internal.warc.gz"} |
https://tug.org/pipermail/texhax/2013-March/020204.html | # [texhax] Font problem.
Rolf Turner r.turner at auckland.ac.nz
Thu Mar 21 00:46:39 CET 2013
A while back I sent an inquiry to this list in respect of how to produce
a solid "heartsuit" symbol. A couple of list participants supplied me with
The simplest answer, it seemed to me, was:
> \font\heartfont=favmr7y at 10pt % set your own size here
> \newbox\heartbox \setbox\heartbox=\hbox{\heartfont\char"56}
> \def\varheart{\leavevmode\copy\heartbox}
That worked fine --- on the laptop that I was then using, which was
running Ubuntu Linux.
I have since acquired a new laptop, and as a result have had to
(for reasons too complicated to explain) switch to Fedora Linux
(version 17).
Just now I tried using the forgoing "varheart" construction and
got an error basically saying that kpathsea could not find font favmr7y.
The complete error output was lengthy, so I am not supplying it here.
If it is relevant I can easily supply it.
I tried doing "sudo yum update texlive" (followed by "sudo texhash")
to see if that would help --- it didn't.
Can anyone advise me what I need to do to make this font available?
I have no idea what extra information I need to provide to assist the
experts
in diagnosing my problem. Please tell me what you need to know and I will
do my best to supply the information.
Note that I am a fairly enlightened user of LaTeX and of Linux in some
respects,
but am a total ignoramus in others --- so please be patient with me!
Thanks.
cheers,
Rolf Turner | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5873169302940369, "perplexity": 4376.497312890176}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-25/segments/1623488504969.64/warc/CC-MAIN-20210622002655-20210622032655-00600.warc.gz"} |
http://bootmath.com/how-is-l_2-minkowski-norm-different-from-l2-norm.html | # How is $L_{2}$ Minkowski norm different from $L^{2}$ norm?
I am reading the book Multidimensional Particle Swarm Optimization for Machine Learning and Pattern Recognition.
They use $L_{2}$ Minkowski norm (Euclidean) as the distance metric in the feature space for Long-Term ECG Classification.
I am myself using just $L^{2}$ seminorm.
I did not find reason why they use Minkowski norm.
Little info here what is Minkowski space.
The book Riemann-Finsley Geometry 2005 says that
The book The Geometry and Spacetime – An Introduction to Special and General Relavity 2000 says that
The Minkowski geometry of spacetime as the invariant theory of Lorentz
transformations, making constant comparisons with the familiar
Euclidean geometry of ordinary space as the invariant theory of
rotations.
The Minkowski space has been used in the inverse problem for nonlinear hyperbolic equations.
What are the advantages of Minkowski norm to $L^{2}$ seminorm when considering ECG classification?
#### Solutions Collecting From Web of "How is $L_{2}$ Minkowski norm different from $L^{2}$ norm?"
The authors of *Multidimensional Particle Swarm” use the ordinary Euclidean metric. They just give it a strange name “$L^2$ Minkowski norm”, in my opinion unnecessarily. But it may be common within the subject area.
The book Riemann-Finsler Geometry gives the definition of a related concept, but it’s not the definition the authors of the first book use. Notice that this is a book from a rather different area of mathematics.
The book Geometry and Spacetime is talking about yet different concept.
Minkowskian distance between two vectors $\mathbf{x}_i$ and $\mathbf{x}_j$ forms the general equation for $L^m$, which is defined as
d(\mathbf{x}_i,\mathbf{x}_j)=\biggl( \sum_{k=1}^p (x_{ik}-x_{jk})^m \biggr)^{1/m},
where $p$ is the number of features.
The Euclidean and Manhattan distance are simply special cases of the $L^1$ and $L^2$ distance, respectively.
Quite basically, you can use almost any distance metric you want for the fitness function. For example, the dot product: $\mathbf{x}_i^T\mathbf{x}_j$, polynomial kernels such as $K(\mathbf{x}_i,\mathbf{x}_j)=(1+\mathbf{x}_i^T\mathbf{x}_j)^d$, or radial basis kernels:
$K(\mathbf{x}_i,\mathbf{x}_j)=\exp[-d(\mathbf{x}_i,\mathbf{x}_j)]$.
Minkowski is merely a general family of distances, and when working with metaheuristics such as PSO it is better to evaluate different distance metrics for their informativeness in class prediction (classification). | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8392846584320068, "perplexity": 925.1792993484283}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-30/segments/1531676589757.30/warc/CC-MAIN-20180717164437-20180717184437-00404.warc.gz"} |
http://wikimedia.7.x6.nabble.com/LaTeX-question-td615346.html | LaTeX question
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Hi, in a formula I write $\frac{\sum_{i=1}^n ...}{...}$. The sum sign appears always in \textmode. I tried to use $\frac{\displaystyle \sum_{i=1}^n ...}{...}$, but during rendering an error occured: unknown function \displaystyle. What can I do to force \displaystyle ? Thanks in advance Sigbert Klinke _______________________________________________ MediaWiki-l mailing list [hidden email] http://mail.wikipedia.org/mailman/listinfo/mediawiki-l
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Re: LaTeX question
> Date: Tue, 28 Feb 2006 13:34:58 +0100 > From: Sigbert Klinke <[hidden email]> > Subject: [Mediawiki-l] LaTeX question > To: [hidden email] > Message-ID: <[hidden email]> > Content-Type: text/plain; charset=ISO-8859-1; format=flowed > > Hi, > > in a formula I write $\frac{\sum_{i=1}^n ...}{...}$. The > sum > sign appears always in \textmode. I tried to use > $\frac{\displaystyle \sum_{i=1}^n ...}{...}$, but during > rendering an error occured: unknown function \displaystyle. What can I > do to force \displaystyle ? > > Thanks in advance > > Sigbert Klinke On en.wikipedia, the texvc program has been updated fairly recently to include support for both \displaystyle and \textstyle. If you're talking about your own wiki, you might consider upgrading your texvc to the latest one available. If that's not possible, I don't think there is any way to force displaystyle. You *can* force textstyle with a nasty hack involving \begin{matrix} ... \end{matrix}, but no such luck with displaystyle. (Maybe someone else can prove me wrong.) David Harvey _______________________________________________ MediaWiki-l mailing list [hidden email] http://mail.wikipedia.org/mailman/listinfo/mediawiki-l | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9433274865150452, "perplexity": 18247.038441301636}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 5, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-30/segments/1563195526888.75/warc/CC-MAIN-20190721040545-20190721062545-00148.warc.gz"} |
https://en.m.wikibooks.org/wiki/Clipper_Tutorial:_a_Guide_to_Open_Source_Clipper(s) | Clipper Tutorial: a Guide to Open Source Clipper(s)
Quite a lot of people were interested in the previous versions of this page, when it was the most visited page in my old website and so, in addition to my personal interest that keeps me delving into the subject, I wish to complete it. The interest in this topic is confirmed by the fact that another Wikibook was created on a very similar theme: Application_Development_with_Harbour, started on September 15, 2010 by the user Raumi75 - on his page he states laconically this intention: «I like the Harbour programming language and hope we can create the missing manual». Unfortunately, the project didn't take off.
This page disappeared when GeoCities was closed (in fact it still contains some broken links to GeoCities pages), and it has been reloaded thanks to some requests I got, for example on Facebook. There you can find the "Harbour MiniGUI" group and many others.
As a newbie to Wikibooks, I did not yet properly format the few sources on this page (Wikibooks has syntax highlighting for Clipper, but it is a bit buggy). If you check it, you will see misplaced links and so... this page definitely needs proofreading!
I'd like to see this tutorial grow! If someone from newsgroups like comp.lang.clipper or mailing lists like HarbourUsers (http://lists.harbour-project.org/mailman/listinfo/harbourusers) or Facebook groups like Harbour Project would give me help or clues, or contribute, it would be great. To apologize for its incompleteness, I can only say that this page contains everything I know about Clipper and xBase programming (in a given moment... I always try to learn new things...). I let digressions sneak in here and there, and also my sense of humor. This book not written in the serious style of all the other Wikibooks I've seen.
I tried to adhere to the classical tutorials' bottom-up approach of showing all the basic functions via very simple examples. The plan to include some bigger examples, with the top-down approach (how do I deal with this problem?) is suggested, but not yet pursued...
At the moment this guide deals mostly with (x)Harbour under Windows, although I plan to describe other environments.
I have decided to name this tutorial "a Guide to Open Source Clipper(s)" and not "a Guide to Open Source xBase" because I like the name Clipper, and as you can see by watching at the open source compilers I discuss (Clip and (x)Harbour) the influence of the name Clipper is great: only the old X2c and now this new thing called X# don't recall the name Clipper. I now consider the name inadequate. Maybe something like Programming With Harbour and Other Free xBase Languages?
Modern xBase open source/free dialects/implementations are:
1. Harbour (https://harbour.github.io/)
2. xHarbour (http://www.xharbour.org/)
which are the most active and mature projects. The second is a fork of the first.
3. Clip, which apparently exists in two versions on SourceForge: https://sourceforge.net/projects/x-clip/ (v 1.2.1.6, Last Update: 2017-06-04) and https://sourceforge.net/projects/clip-itk/
4. X#, which is an implementation for .NET (https://www.xsharp.info/, https://github.com/X-Sharp/XSharpPublic). It looks interesting but the runtime is missing. The documentation is at https://www.xsharp.info/help/index.html.
5. DBFree (http://www.dbfree.org) is used to create web applications and is open source, even if it contains components, such the fundamental component - the xBase interpreter MaxScript (http://maxscript.org/, http://www.maxsis.it) is not: it's just freeware.
X2c (http://web.archive.org/web/20090416070816/http://x2c.dtop.com/, http://freshmeat.sourceforge.net/projects/x2c) is very old - what use can it have for a modern programmer if the download links don't work and the only freely available C compiler can be found at the website Embarcadero Antique Software, namely https://cc.embarcadero.com/item/25636? However, I like some of its examples and I'll mention them.
This Guide was born as a set of notes when I followed a small project (I was asked about the possibility of porting an old Summer 87 program to Windows - and I did it by simply recompiling the source code to check Harbour's compatibility with Clipper, and creating a small Windows program, which showed a simple splash screen and an interface where the menu entries pointed to stubs). The experience was encouraging, although the Windows version of that application was never actually realized. Its by-product, my notes, evolved. Their first objective was to redo the examples of a "PC GUIDE", the first of eight booklets of a self-instruction course in the Clipper language bought on an Italian newsstand in 1993.
I noticed also that there were no good tutorials and that the books about dBase/Clipper/xBase/Visual Objects and so on couldn't be found in any bookstore (and only with great difficulty in libraries!).
Some old versions of these notes can be found on GeoCities mirrors - (I'd like to thank W. Birula for letting me know, not to mention his suggestion of uploading my set of notes on Wikibook, and also for the flowchart he kindly provided). Thanks to bpd2000 for the interesting link he provided.
When (and if) finished, it will prove a complete guide to Open Source Clipper programming. However, this page is still very incomplete.
The current plan consists of two introductory chapters, then the first part of the tutorial will cover the basic of the language, up to the procedural programming facilities and the native database-DBF file support. Part 3 will explain OOP and other programming topics, and the last part will be about programming a user interface and web applications. This could even make up for a nice introduction to computer science!
Michele Povigna
1. Part 1: Introduction
2. Part 2: The Common Ground
3. Part 3: Additions to the Language
• Chapter 5: Object Oriented Programming
• Chapter 6: Other Features
4. Part 4: Real Applications
Getting Started
In practice, (x)Harbour permits a great versatility, as it (they) can be used in four different ways:
1. by running hbrun or xbscript and executing instructions interactively (much like a BASIC direct mode or immediate mode, although it is more similar to the dBase dot prompt). The main limit of this approach is that it cannot run expressions longer than a single line (but it is possible to enter more instructions on a line separating them with semicolons). However, much of my tutorial is thought to be entered, tested and understood one line at a time.
2. by calling hbrun or xbscript specifying a .prg file as a line argument to execute it (which is again like specifying a file to run when invoking a BASIC interpreter)
3. by compiling the file to a bytecode using the /gh option of the Harbour compiler and then running the resulting .hrb bytecode file with hbrun (this is similar to Java's workflow when you call the compiler javac and then the Java interpreter on the bytecode file)
4. by using the Harbour compiler, C compiler and linker to get an executable file (utilities are given to get all the steps done in a single command)
5. by using the compiler through an IDE
There are also commercial RADs, like Xailer (https://www.xailer.com/) or xHarbour Builder (https://www.xharbour.com/).
Antonino Perricone wrote an extension for Visual Studio Code, which is well documented at https://github.com/APerricone/harbourCodeExtension/wiki, https://medium.com/harbour-magazine/visual-studio-code-for-harbour-e148f9c1861a, https://harbour.wiki/index.asp?page=PublicArticles&mode=show&id=190401174818&sig=6893630672. The main problem with the precompiled version of Visual Studio Code is that it's not under the MIT license.
Packages providing syntax highlighting for various editors are available: for Sublime Text (https://www.sublimetext.com/) is available at https://github.com/asistex/Sublime-Text-harbour-Package, for SynWrite (http://www.uvviewsoft.com/synwrite/) at https://github.com/rafathefull/synwrite, for Atom Editor (https://atom.io/) at https://github.com/AtomLinter/linter-harbour, UltraEdit at http://forums.ultraedit.com/syntax-highlighting-wordfile-for-harbour-fivewin-t17880.html. I myself like Scintilla (https://www.scintilla.org/), a lightweight open source editor that supports the xBase syntax highlighting under the name Flagship - which is an implementation different from the open source ones we are considering but that does not make much difference and it's anyway highly configurable.
Using Harbour From a Windows Command Prompt
Simply open a command prompt and move to the directory where you store your sources. Issue a PATH command pointing to the bin directory of your Harbour system (this is to avoid problems if you've got different compilers in your system). I also add the path of a text editor to use from the prompt, like this:
D:\harbourcode>PATH c:\hb32\bin;D:\wscite
Getting Started With hbIDE
1. To create a new project, select File > New > New Project Wizard (Prototype Only). We will name this project hbidetest, enter the path C:/hb32/projects/hbidetest.hbp and click Save and Close.
2. Select File > Open Project in the menu bar.
3. Right click the project hbidetest in the projects dock on the right and "Set as Current" project.
4. Select File > New > Source and create a file hbidetest.prg with the following content:
function MAIN
* This is an example
clear
?"Hello, the weather is fine today"
?"(this is a test of HbIDE)"
wait && will show "Press any key to continue..." and prevent the console window to close immediately
return
5. Double click hbidetest in the projects dock so that the and click the Select Sources button near the Project Output text box, then select Save and close. It is a button not very well indicated - I think a button clearly stating "Add source file" would have been better.
6. Now after selecting Build > Build and Launch our program will show up.
Working with Databases
Different kinds of database applications exist as well. If you did store your friend's phone numbers and addresses into a word processor, you would have what someone calls a Free-Form Database (however, a similar expression is an oxymoron in computer science) - myBase®, askSam®, Personal Knowbase®, MyInfo®, Info Select®, and GeneralKB® are a bunch of specialized free-form database application, which actually means PIM (Personal information manager). Now, a word processor lets us search the information, but other operations, such as sorting them in alphabetical or numerical order, cannot be done automatically by a word processor.
What about attempting to store it into a spreadsheet? We may use one column for the name, one for the surname, one for the telephone number, one for the city. This quick database, stored in a spreadsheet, may be searched and sorted: for example, we can sort it by city and person's name in alphabetical order. This is a flat database, http://www2.research.att.com/~gsf/man/man1/cql.html: a flat database is a sequence of newline terminated records of delimiter separated fields, and a spreadsheet shows its limits in data entry and reporting (if you did want to use the data in your table to print out addresses on envelopes a spreadsheet is not a good tool). An example is MyDatabase (http://www.pcmag.com/article2/0,2817,760833,00.asp).
Spreadsheets are much better to do accounting: how much harder a book-keeper's work would be if his data were stored in a wordprocessing program? The purpose here is to have our data structured in a certain way: all the costs in a place, all earnings in another.
Before 1970 complex databases were managed using Hierarchical Databases (very little information is needed about them - see for example http://www.extropia.com/tutorials/sql/hierarchical_databases.html and http://people.cs.pitt.edu/~chang/156/14hier.html). An example of a hierarchical database is IBM IMS (Information Management System, which was developed during the mid-1960s for applications in the aerospace industry). Their implementation is based on trees, a hierarchical data structure. Hierarchical Databases and Network Databases together form what today are referred to as Legacy Database Systems. Network databases were born as an extension to the programming language COBOL by the Conference on Data Systems Languages (CODASYL). The hierarchical data model is based on data structures called graphs.
Today's standard is the Relational Database (RDBMS), which is "a database with relationships between more than one table of records based on common fields". We will speak of them in some detail, but we will briefly mention the fourth approach: Object Oriented Databases. These databases store objects (in the same sense the word is used in the expression object-oriented programming). They're not much used, mostly because objects are more complex than the simple fields a relational database stores in its tables. More information on the topic at http://www.odbms.org/odmg-standard/.
The Wikipedia entry about DBase reads: «dBase is application development language and integrated navigational database management system which Ashton-Tate labeled as "relational" but it did not meet the criteria defined by Dr. Edgar F. Codd's relational model». Codd's criteria (the so-called 12 rules, which really are 13 because the rule numbered '0' actually exists) are so strict that in practice a true relational database system does not even exist, but the point is that dBase accessed databases in another way, so that it's considered a Navigational Database (which works in a way that simulates relational databases).
DBF Files in Other Languages
Because of the great success of dBase and its, the DBF file format became an industry standard. Many other database programs have used them to store data, like Lotus Approach. We also have many little utilities to view and convert to other formats these files. Here is a bunch of URLs: https://dbfview.com/, http://www.alexnolan.net/software/dbf.htm, https://dbfviewer.com/en/, https://www.dbf2002.com/, http://www.whitetown.com/dbf2sql/ («DBF to SQL Converter allows you to convert your dbf files to SQL script. Personal license $29.95», but compare https://www.vlsoftware.net/exportizer/). And is so widely used that interfaces for working with it are available for various languages, for example: Well, now we will see how to work with DBF files the way it was intended. Making a first database and recording some data A verbose way && it was done this way at the Dot Prompt && we can type this interactively in hbrun CREATE TMPNAMES USE TMPNAMES APPEND BLANK REPLACE FIELD_NAME WITH "NAME" REPLACE FIELD_TYPE WITH "C" REPLACE FIELD_LEN WITH 15 APPEND BLANK REPLACE FIELD_NAME WITH "ADDRESS" REPLACE FIELD_TYPE WITH "C" REPLACE FIELD_LEN WITH 30 CLOSE CREATE NAMES FROM TMPNAMES && https://www.itlnet.net/programming/program/Reference/c53g01c/ngc785e.html ERASE TMPNAMES.DBF && we get rid of the temporary file The code above created a DBF file, names.dbf, to be used by the following code. It will add a record to the DBF file. It is equivalent to the "First Sample Program" of my old PC GUIDE, which missed a line that is necessary in modern xBase. CLEAR ? "First Sample Program" SELECT 1 USE NAMES APPEND BLANK REPLACE NAME WITH "MIKE BROWN" REPLACE ADDRESS WITH "ROME STREET, 56" CLOSE && this line is missing in my PC GUIDE but is needed in a compiled Harbour program QUIT The CLOSE command is equivalent to the dbCloseArea() function, which closes a work area: Pending updates are written, pending locks are released. A more concise way The short code below does the same work of the two pieces of code of the previous section (it only produces a different file name, namesdb.dbf instead of names.dbf). local aStruct := { { "NAME", "C", 15, 0 }, ; { "ADDRESS", "C", 30, 0 }} REQUEST DBFCDX dbCreate( "namesdb", aStruct, "DBFCDX", .t., "NAMESDB" ) && http://www.fivetechsoft.com/harbour-docs/api.html USE NAMESDB NAMESDB->(DbAppend()) NAMESDB->NAME := "MIKE BROWN" NAMESDB->ADDRESS := "ROME STREET, 56" This example uses the alias operator, ->. http://www.ousob.com/ng/clguide/ngcf412.php The alias->field_name notation is used to allow access to fields of databases that are loaded but not active. The alias can be specified with the work area number (e.g. 2->std_id), with the work area alias (e.g. B->std_id), or with the database name (e.g. STUDENTS->std_id). The result of this code is a file named namesdb.dbf. Informations about how DBF files are can be find at DBF File structure, http://www.dbf2002.com/dbf-file-format.html, where we find this list of Field type: • C – Character • Y – Currency • N – Numeric • F – Float • D – Date • T – DateTime • B – Double • I – Integer • L – Logical • M – Memo • G – General • C – Character (binary) • M – Memo (binary) • P – Picture • + – Autoincrement (dBase Level 7) • O – Double (dBase Level 7) • @ – Timestamp (dBase Level 7) My PC GUIDE showed how a .dbf file is made with the DataBase Utility DBU. Clones of this utility are FiveDBU (with source code) at https://code.google.com/archive/p/fivewin-contributions/downloads, DBF Viewer Plus at http://www.alexnolan.net/software/dbf.htm, CLUT at http://www.scovetta.com/archives/simtelnet/msdos/clipper. Harbour includes its own HbDBU (the source is in \hb32\addons\hbdbu) and a component IdeDBU of HbIDE (the other two components are IdeEDITOR and IdeREPORTS). From https://code.google.com/archive/p/fivewin-contributions/downloads we can get fivedbu_20130930.zip (New FiveDBU version with enhancements on ADO fields editing). It supports ADO, 3 RDD (DBFNTX, CBFCDX and RDDADS) and 6 languages - select "Bases de datos -> Preferencias -> Lenguaje: Inglés" to have it in English. Let us see what is in our little file so far. USE NAMES LIST DATE(), TIME(), NAME, ADDRESS Database Design Issue: the First Normal Form (1NF) The work done in the previous section was intended to exactly reproduce the database presented in my PC GUIDE. There are, however, drawbacks: having only one NAME field, this database cannot sort its data on the last name. Also, a careless user might insert the data of some people with the last name first, and some other data with the first name last. When designing a database precautions should be taken of these possibilities. The first normal form (http://www.1keydata.com/database-normalization/first-normal-form-1nf.php, http://www.sqa.org.uk/e-learning/SoftDevRDS02CD/page_14.htm) requires you to define fields whose information cannot be divided into smaller parts. So, instead of a NAME field, we should have a FIRST_NAME and LAST_NAME fields. Complying to the first normal form, our little database would be on the on the right track to being a normalized database. Designing the database is an essential part of the work and it is not always obvious how it should be done. See https://www.ntu.edu.sg/home/ehchua/programming/sql/relational_database_design.html. A graphical device used to help is database design are the Entity-Relationship Diagrams: https://www.lucidchart.com/pages/er-diagrams, https://www.guru99.com/er-diagram-tutorial-dbms.html. Complicating our simple database Harbour contains a file named test.dbf. Launch hbrun in its directory and type in use test browse() At this point, we see that it is a 500 record table. Move around with the cursor keys and, when you're finished, punch the Esc key to quit this interactive table browser and editor. To get the record number of a person called Ted issue: locate for first="Ted" ? recno() Here is the testdbf.prg source from \hb30\tests. It should be discussed in detail. It is a GPL piece of code poorly commented. /* *$Id: testdbf.prg 1792 1999-11-10 10:17:19Z bcantero $*/ function main() local nI, aStruct := { { "CHARACTER", "C", 25, 0 }, ; { "NUMERIC", "N", 8, 0 }, ; { "DOUBLE", "N", 8, 2 }, ; { "DATE", "D", 8, 0 }, ; { "LOGICAL", "L", 1, 0 }, ; { "MEMO1", "M", 10, 0 }, ; { "MEMO2", "M", 10, 0 } } REQUEST DBFCDX dbCreate( "testdbf", aStruct, "DBFCDX", .t., "MYALIAS" ) ? "[" + MYALIAS->MEMO1 + "]" ? "[" + MYALIAS->MEMO2 + "]" ? "-" MYALIAS->( dbAppend() ) MYALIAS->MEMO1 := "Hello world!" MYALIAS->MEMO2 := "Harbour power" ? "[" + MYALIAS->MEMO1 + "]" ? "[" + MYALIAS->MEMO2 + "]" MYALIAS->( dbAppend() ) MYALIAS->MEMO1 := "This is a test for field MEMO1." MYALIAS->MEMO2 := "This is a test for field MEMO2." ? "[" + MYALIAS->MEMO1 + "]" ? "[" + MYALIAS->MEMO2 + "]" MYALIAS->NUMERIC := 90 MYALIAS->DOUBLE := 120.138 ? "[" + Str( MYALIAS->DOUBLE ) + "]" ? "[" + Str( MYALIAS->NUMERIC ) + "]" ? "" ? "Press any key..." InKey( 0 ) ? "" ? "Append 50 records with memos..." for nI := 1 to 50 MYALIAS->( dbAppend() ) MYALIAS->MEMO1 := "This is a very long string. " + ; "This may seem silly however strings like this are still " + ; "used. Not by good programmers though, but I've seen " + ; "stuff like this used for Copyright messages and other " + ; "long text. What is the point to all of this you'd say. " + ; "Well I am coming to the point right now, the constant " + ; "string is limited to 256 characters and this string is " + ; "a lot bigger. Do you get my drift ? If there is somebody " + ; "who has read this line upto the very end: Esto es un " + ; "sombrero grande rid¡culo." + Chr( 13 ) + Chr( 10 ) + ; "/" + Chr( 13 ) + Chr( 10 ) + "[;-)" + Chr( 13 ) + Chr( 10 )+ ; "\" next MYALIAS->( dbCommit() ) ? "Records before ZAP:", MYALIAS->( LastRec() ) ? "Size of files (data and memo):", Directory( "testdbf.dbf" )[1][2], ; Directory( "testdbf.fpt" )[1][2] MYALIAS->( __dbZap() ) MYALIAS->( dbCommit() ) ? "Records after ZAP:", MYALIAS->( LastRec() ) ? "Size of files (data and memo):", Directory( "testdbf.dbf" )[1][2], ; Directory( "testdbf.fpt" )[1][2] ? "Value of fields MEMO1, MEMO2, DOUBLE and NUMERIC:" ? "[" + MYALIAS->MEMO1 + "]" ? "[" + MYALIAS->MEMO2 + "]" ? "[" + Str( MYALIAS->DOUBLE ) + "]" ? "[" + Str( MYALIAS->NUMERIC ) + "]" ? "Press any key..." InKey( 0 ) dbCloseAll() dbCreate( "testdbf", aStruct,, .t., "MYALIAS" ) for nI := 1 to 10 MYALIAS->( dbAppend() ) MYALIAS->NUMERIC := nI ? "Adding a record", nI if nI == 3 .or. nI == 7 MYALIAS->( dbDelete() ) ? "Deleting record", nI endif next MYALIAS->( dbCommit() ) ? "" ? "With SET DELETED OFF" ? "Press any key..." InKey( 0 ) MYALIAS->( dbGoTop() ) do while !MYALIAS->( Eof() ) ? MYALIAS->NUMERIC MYALIAS->( dbSkip() ) enddo SET DELETED ON ? "" ? "With SET DELETED ON" ? "Press any key..." InKey( 0 ) MYALIAS->( dbGoTop() ) do while !MYALIAS->( Eof() ) ? MYALIAS->NUMERIC MYALIAS->( dbSkip() ) enddo ? "" ? "With SET DELETED ON" ? "and SET FILTER TO MYALIAS->NUMERIC > 2 .AND. MYALIAS->NUMERIC < 8" ? "Press any key..." InKey( 0 ) MYALIAS->( dbSetFilter( { || MYALIAS->NUMERIC > 2 .AND. MYALIAS->NUMERIC < 8 }, ; "MYALIAS->NUMERIC > 2 .AND. MYALIAS->NUMERIC < 8" ) ) MYALIAS->( dbGoTop() ) do while !MYALIAS->( Eof() ) ? MYALIAS->NUMERIC MYALIAS->( dbSkip() ) enddo SET DELETED OFF ? "" ? "With SET DELETED OFF" ? "and SET FILTER TO MYALIAS->NUMERIC > 2 .AND. MYALIAS->NUMERIC < 8" ? "Press any key..." InKey( 0 ) MYALIAS->( dbSetFilter( { || MYALIAS->NUMERIC > 2 .AND. MYALIAS->NUMERIC < 8 }, ; "MYALIAS->NUMERIC > 2 .AND. MYALIAS->NUMERIC < 8" ) ) MYALIAS->( dbGoTop() ) do while !MYALIAS->( Eof() ) ? MYALIAS->NUMERIC MYALIAS->( dbSkip() ) enddo ? "dbFilter() => " + dbFilter() ? "" ? "Testing __dbPack()" ? "Records before PACK:", MYALIAS->( LastRec() ) ? "Size of files (data and memo):", Directory( "testdbf.dbf" )[1][2], ; Directory( "testdbf.dbt" )[1][2] SET FILTER TO MYALIAS->( __dbPack() ) MYALIAS->( dbCommit() ) ? "Records after PACK:", MYALIAS->( LastRec() ) ? "Size of files (data and memo):", Directory( "testdbf.dbf" )[1][2], ; Directory( "testdbf.dbt" )[1][2] ? "Press any key..." InKey( 0 ) ? "Value of fields:" MYALIAS->( dbGoTop() ) do while !MYALIAS->( Eof() ) ? MYALIAS->NUMERIC MYALIAS->( dbSkip() ) enddo ? "" ? "Open test.dbf and LOCATE FOR TESTDBF->SALARY > 145000" ? "Press any key..." InKey( 0 ) dbUseArea( ,, "test", "TESTDBF" ) locate for TESTDBF->SALARY > 145000 do while TESTDBF->( Found() ) ? TESTDBF->FIRST, TESTDBF->LAST, TESTDBF->SALARY continue enddo ? "" ? "LOCATE FOR TESTDBF->MARRIED .AND. TESTDBF->FIRST > 'S'" ? "Press any key..." InKey( 0 ) dbUseArea( ,, "test", "TESTDBF" ) locate for TESTDBF->MARRIED .AND. TESTDBF->FIRST > 'S' do while TESTDBF->( Found() ) ? TESTDBF->FIRST, TESTDBF->LAST, TESTDBF->MARRIED continue enddo return nil Input Mask A simple data base input mask (from the Wikipedia Clipper entry): USE Customer SHARED NEW clear @ 1, 0 SAY "CustNum" GET Customer->CustNum PICT "999999" VALID Customer->CustNum > 0 @ 3, 0 SAY "Contact" GET Customer->Contact VALID !empty(Customer->Contact) @ 4, 0 SAY "Address" GET Customer->Address READ RDDs: What Functions Are Available? ADO RDD: Much Ado About Nothing Case Study: Checkbook Balancing Deleting records ? LASTREC() DELETE RECORD 4 PACK ? LASTREC() In this piece of code, the command DELETE marks the fourth record for deletion. But the file is not altered, not even by a CLOSE command. The PACK command actually removes the records marked for deletion (and also makes some additional work). The RECALL command removes the deleted flags. The function DELETED() returns .T. if the current record is marked for deletion, .F. if not. The PACK command, which does the actual deletion of data from the table, PACK requires that the current database be USEd EXCLUSIVEly. If this condition is not met when the PACK command is invoked, CA-Clipper generates a runtime error. Additional work that PACK does is to update indexes on the table it alters (if any). The commands DELETE ALL and PACK are executed by a single command called ZAP. && This example demonstrates a typical ZAP operation in a network && environment: USE Sales EXCLUSIVE NEW IF !NETERR() SET INDEX TO Sales, Branch, Salesman ZAP CLOSE Sales ELSE ? "Zap operation failed" BREAK ENDIF An Indexed Example USE Clients NEW INDEX ON Name TO Clients UNIQUE Suppose a table containing these data: FSTNAME LSTNAME John Doe John Doe John Doe Jane Doe We can create a little index file with this piece of code: SELECT 1 USE ind ? FILE("ind.ntx") INDEX ON FstName TO ind ? FILE("ind.ntx") // we verify that a NTX file has been created Set Relation - Working with more than one table Other programming topics Hash Arrays (Associative Arrays, Also Known as "Hash Tables") In an associative array the elements are accessed using a string and not a number as in the "normal" array. There are online "Calorie checkers" (which are also a nice idea for a web application for the last part) and I think it will be fun to make us a very small one (BEWARE: the information obtained from this program should not replace a varied, balanced diet and a healthy lifestyle). hFood := { => } hFood["Cornflakes"] := "370" hFood["Spaghetti"] := "101" hFood["Beef"] := "280" hFood["Ham"] := "240" hFood["Broccoli"] := "32" hFood["Grapefruit"] := "32" hFood["Spinach"] := "8" hFood["Chocolate"] := "500" ACCEPT "Enter a food: " TO cFood IF hb_HHasKey( hFood, cFood ) ? "&cFood is " + hFood[cFood] + " calories per 100 grams" ELSE ? "&cFood: information not available" ENDIF Now we will redo the example of the array of months, showing an alternative syntax for loading data into an hash array: LOCAL month hMonths := { "January" => 31, "February" => 28, "March" => 30, "April" => 30, "May" => 31, "June" => 30, "July" => 31, "August" => 31, "September" => 30, "October" => 31, "November" => 30, "December" => 31 } FOR EACH month in hMonths ? month:__ENUMKEY() ?? month:__ENUMVALUE() NEXT hb_HEval() is the AEval() equivalent for hash arrays. Morse Code Morse code was invented around 1840 by Samuel Finley Breese Morse and Alfred Vail to transmit messages across wires using devices called "telegraphs" they invented as well, revolutionizing long-distance communication. Initially the signals sent from one telegraph operated an electromagnet on the receiver's telegraph embossing the message on a strip of paper, later the receiver could also produce a sound. The first message transmitted was a citation of the book of Numbers from the King James Version: What hath God wrought! Let us try to convert a text to Morse code: to begin we load the chart of Morse code in an associative array and define a code block which uses the function TONE() to sound a speaker tone for a dot or a dash - employing the IF() function - which is essentially the same function we encounter in spreadsheets - to select the right duration tone. Then we prompts the user for a message and if none is supplied it uses the pangram "The quick brown fox jumps over a lazy dog" (a pangram is a sentence that contains all of the letters of the alphabet). We show what message we will translate and starts two a for each loop: the first will scan the message showing which letter it will translate, one at a line (and will also use TONE() with zero frequency and appropriate lengths to make the pauses between letters and words) and then a nested for each loop will show whether it is about to sound a dot or a dash, running the code block to have the right sound. LOCAL letter, ditdah hMorseCode := { => } hMorseCode[ "a" ] := ".-" hMorseCode[ "b" ] := "-..." hMorseCode[ "c" ] := "-.-." hMorseCode[ "d" ] := "-.." hMorseCode[ "e" ] := "." hMorseCode[ "f" ] := "..-." hMorseCode[ "g" ] := "--." hMorseCode[ "h" ] := "...." hMorseCode[ "i" ] := ".." hMorseCode[ "j" ] := ".---" hMorseCode[ "k" ] := "-.-" hMorseCode[ "l" ] := ".-.." hMorseCode[ "m" ] := "--" hMorseCode[ "n" ] := "-." hMorseCode[ "o" ] := "---" hMorseCode[ "p" ] := ".--." hMorseCode[ "q" ] := "--.-" hMorseCode[ "r" ] := ".-." hMorseCode[ "s" ] := "..." hMorseCode[ "t" ] := "-" hMorseCode[ "u" ] := "..-" hMorseCode[ "v" ] := "...-" hMorseCode[ "w" ] := ".--" hMorseCode[ "x" ] := "-..-" hMorseCode[ "y" ] := "-.--" hMorseCode[ "z" ] := "--.." hMorseCode[ "0" ] := "-----" hMorseCode[ "1" ] := ".----" hMorseCode[ "2" ] := "..---" hMorseCode[ "3" ] := "...--" hMorseCode[ "4" ] := "....-" hMorseCode[ "5" ] := "....." hMorseCode[ "6" ] := "-...." hMorseCode[ "7" ] := "--..." hMorseCode[ "8" ] := "---.." hMorseCode[ "9" ] := "----." nDotDuration := 4 && The dot duration is the basic unit of time measurement in Morse code transmission and we set it to 4/18 seconds bPlayMorse := {| cCurrent| if ( cCurrent = ".", Tone( 480, nDotDuration ), Tone( 480, nDotDuration * 3 ) ) } ACCEPT "Enter message: " TO message IF message == "" && if no message we use a default one message := "The quick brown fox jumps over a lazy dog" && an English-language pangram — a sentence that contains all of the letters of the alphabet ENDIF ? "Converting '"+Upper( message )+"' in Morse..." FOR EACH letter in Lower( message ) ? Upper(letter)+" " IF letter==" " Tone( 0, nDotDuration * 7 ) && a long pause between words... ELSE FOR EACH ditdah in hMorseCode[ letter ] ?? ditdah Eval( bPlayMorse, ditdah ) NEXT ENDIF Tone( 0, nDotDuration * 3 ) && ... and a short pause between letters NEXT Regular Expressions Regular expressions can be considered an extension of wildcards. In a DOS or Windows prompt, for example, we could list all dbf files in the current directory with the command dir *.dbf where the asterisk, as they say, matches one or more characters. The other wildcard, the question mark, will match any character, but exactly one: the commands dir ?.dbf dir ??.dbf will show, respectively, every dbf file in the current directory whose name is exactly one or two characters long. Regular expressions are much more flexible. They were invented by the mathematician Stephen Cole Kleene (the asterisk wildcard derives from an operator he defined and which is called Kleene star). Their flexibility allows us to write an expression that can match dbf filenames one or two characters long in a single expression which looks like this: .{1,2}\.dbf There are different types of regular expressions: basic, extended, PCRE (Perl-compatible regular expressions, http://www.pcre.org/), and many other different implementations. As far as we are concerned we can limit ourselves to PCRE and refer to the documentation at these URLs: https://github.com/Petewg/harbour-core/wiki/Regular-Expressions and https://github.com/zgamero/sandbox/wiki/X_RegularExpressions, https://www.pcre.org/original/doc/html/pcrepattern.html, https://www.debuggex.com/cheatsheet/regex/pcre. There are large books entirely devoted about regular expressions, such as "Mastering Regular Expressions" by Jeffrey E.F. Friedl, just to say there's so much to explore about this topic. Here https://www.rexegg.com/regex-cookbook.html is a cookbook to see examples; and here https://www.regexpal.com/ and here https://regexr.com/ there are interactive tools to try online (and interactively) expressions. Regular expressions are not a panacea that solves all data validation problems: for example, it is not possible to use them to validate dates, as the number of days allowed for each month depends on the month (and in the case of February also on the year). As a first example, we will redo the program that receives a letter from the keyboard and reports if it is a vowel or not. LOCAL cRegEx := "[aeiou]" WAIT "Key in a letter: " TO char ? char + " is" + iif( hb_regexLike( cRegEx, char, .F. ), "", " not" ) + " a vowel." The synopsis of hb_RegExLike is this: hb_RegExLike(<hRegEx>|<cRegEx>, <cText> [, <lCaseSensitive>] [, <lMultiLine>]). The next example is again the program to average of an array which grows until we insert numbers as input. This time we use a regular expression to validate the numbers we enter. PROCEDURE MAIN LOCAL n, sum := 0, average && let's initialize the variables LOCAL reNumber := "-?[0-9]+(\.?[0-9]+)?" && and a regular expression that matches numbers (optionally with a decimal point and a sign) aNumbers := {} && and an empty array ? "enter a list of integer numbers, and a non-number when you are finished" WHILE .T. && we begin an endless loop ACCEPT "next element: " TO item IF hb_RegExLike ( reNumber, item ) && we replace IsDec() with hb_RegExLike() AAdd ( aNumbers, val(item) ) && if we did, then we add the number as a new element to the array sum := sum + val(item) && (and we update the sum of the elements in our array)... ELSE EXIT && ...if we did not, we quit this loop ENDIF ENDDO average := sum / Len( aNumbers ) && we compute the average of the values in the array ? ? "to average the array you must correct each element by adding to it the corresponding value below" ? FOR n := 1 to LEN ( aNumbers ) ?? AVERAGE - aNumbers[n] NEXT RETURN Error Handling With “Try-Catch-Finally” Block This construct is analogous to those found in Java, JavaScript and C# (and similar to the C++'s one). They are actually translated into the BEGIN SEQUENCE structure and therefore perhaps they are useful only for those who are accustomed to those languages. PROCEDURE MAIN LOCAL n, sum := 0, average && let's initialize the variables aNumbers := {} && and an array without elements ? "enter a list of integer numbers, and a non-number when you are finished" WHILE .T. && we begin an endless loop ACCEPT "next element: " TO item TRY AAdd ( aNumbers, &item ) && if we did, then we add the number as a new element to the array sum := sum + &item && (and we update the sum of the elements in our array)... CATCH EXIT && ...if we did not, we quit this loop END ENDDO average := sum / Len( aNumbers ) && we compute the average of the values in the array ? ? "to average the array you must correct each element by adding to it the corresponding value below" ? FOR n := 1 to LEN ( aNumbers ) ?? AVERAGE - aNumbers[n] NEXT RETURN Multithreading see samples in \hb30\tests\mt INET PDF hbhpdf: Libharu http://libharu.org/ bindings. Documentation: https://github.com/libharu/libharu/wiki/API%3A-Document How to create a DLL Debugging You may have heard or read the legend that the term bug appeared when an actual bug was found in the Harvard's Mark II computer. According to one of my books from the high school, it was a little butterfly found in the ENIAC! Text books less prone to folklore call this a story without foundation, for example https://www.computerworld.com/article/2515435/moth-in-the-machine--debugging-the-origins-of--bug-.html states that Thomas Edison used the word already in 1878. The same goes with the Wikipedia entry →Software bug which even includes a picture of the moth actually found in the Harvard Mark II and describes the whole history. A page from the →Harvard Mark II electromechanical computer's log, featuring a dead moth that was removed from the device. Object Oriented Programming Clipper had very limited support for OO programming. His successor CA-Visual Objects was much more advanced in this respect. However Visual Objects never had a great success, and third-party producers provided OOP libraries for Clipper, among which the most famous were Class(y), TopClass, Fivewin and Clip4Win. Looking at Object-Oriented Programming from a Safety Distance Let us suppose we're dealing with the distance function given the Cartesian coordinates of the points (http://mathinsight.org/cartesian_coordinates). The formulas we'll apply are: ${\displaystyle D_{1}={\sqrt {(x_{2}-x_{1})^{2}}}}$ ${\displaystyle D_{2}={\sqrt {(x_{2}-x_{1})^{2}+(y_{2}-y_{1})^{2}}}}$ ${\displaystyle D_{3}={\sqrt {(x_{2}-x_{1})^{2}+(y_{2}-y_{1})^{2}+(z_{2}-z_{1})^{2}}}}$ for (Euclidean) distance on a real line, Euclidean plane and Euclidean space respectively. In procedural programming our functions would look like this: ? distance1d(4,-3) ? distance2d(2,-3,-1,-2) ? distance3d(1,1,1,4,4,4) FUNCTION distance1d( x1, x2 ) RETURN sqrt((x2-x1)^2) FUNCTION distance2d( x1,y1,x2,y2 ) RETURN sqrt((x2-x1)^2+(y2-y1)^2) FUNCTION distance3d( x1,y1,z1,x2,y2,z2 ) RETURN sqrt((x1-x2)^2+(y1-y2)^2+(z1-z2)^2) We defined three functions, with different names, which take as arguments the coordinates. But doing so we need to pass six arguments for the distance in a three-dimensional space. If we're doing it with object oriented programming we may get something like this: #include "hbclass.ch" CREATE CLASS Point1D VAR Abscissa // the abscissa of our point METHOD New( Abscissa ) // Constructor METHOD Distance( Point ) ENDCLASS CREATE CLASS Point2D INHERIT Point1D VAR Ordinate // the ordinate of our point METHOD New( Abscissa, Ordinate ) // Constructor METHOD Distance( Point ) ENDCLASS CREATE CLASS Point3D INHERIT Point2D VAR Zcoord // the Z-coordinate of our point METHOD New( Zcoord ) // Constructor METHOD Distance( Point ) ENDCLASS && Constructors Zone METHOD New( Abscissa ) CLASS Point1D ::Abscissa := Abscissa RETURN Self METHOD New( Abscissa, Ordinate ) CLASS Point2D ::Abscissa := Abscissa ::Ordinate := Ordinate RETURN Self METHOD New( Abscissa, Ordinate, Zcoord ) CLASS Point3D ::Abscissa := Abscissa ::Ordinate := Ordinate ::Zcoord := Zcoord RETURN Self &&Distances Methods METHOD Distance( Point ) CLASS Point1D RETURN Sqrt( ( Self:Abscissa - Point:Abscissa ) ^ 2 ) METHOD Distance( Point ) CLASS Point2D RETURN Sqrt( ( Self:Abscissa - Point:Abscissa ) ^ 2 + ( Self:Ordinate - Point:Ordinate ) ^ 2 ) METHOD Distance( Point ) CLASS Point3D RETURN Sqrt( ( Self:Abscissa - Point:Abscissa ) ^ 2 + ( Self:Ordinate - Point:Ordinate ) ^ 2 + ( Self:Zcoord - Point:Zcoord ) ^ 2 ) PROCEDURE Main() FirstPoint := Point1D():New( 3 ) SecondPoint := Point1D():New( - 3 ) ? FirstPoint:Abscissa ? FirstPoint:Distance( SecondPoint ) ThirdPoint := Point2D():New( 2, - 3 ) FourthPoint := Point2D():New( - 1, - 2 ) ? ThirdPoint:Distance( FourthPoint ) FifthPoint := Point3D():New( 1, 1, 1 ) SixthPoint := Point3D():New( 4, 4, 4 ) ? FifthPoint:Distance( SixthPoint ) RETURN Here we've defined three classes, their constructors, and a distance method for each of them, and showed how to use them. It is also a simple example of how inheritance works. Other concepts are encapsulation (information hiding or data hiding), abstraction, polymorphism, overloading and overriding of methods. Inheritance plays a central role in a key concept: reuse. A class can be reused in a software project if it is exactly what was needed; or if it is not exactly what was needed it can be extended by defining a subclass. Much like the design of a database, the design of object oriented class is an art with its principles, see for example http://www.oodesign.com/, http://www.codeproject.com/articles/567768/object-oriented-design-principles and pages about UML like http://www.uml-diagrams.org/uml-object-oriented-concepts.html. The first thing to note is that we start by including the clipper header file hbclass.ch, the header file for Class commands. Access to variables and methods of an object is done via the colon operator. A prepended double colon refers to variables with a larger scope (such as those passed to a method). In the code above we defined three classes, each one implementing a Point. Point2D for example was defined as a class extending Point1D, that is a generalization of the concept. A method Distance was given for each of the classes. A line such as ? FifthPoint:Distance( SixthPoint ) contain the output command ?, the reference to an object (FifthPoint in this case), an invocation of the Distance method :Distance, to which another point was passed ( SixthPoint ). It is also possible to write a Distance function which takes two arguments of a Point class, that may look like this: FUNCTION Distance ( Point1, Point2 ) RETURN Sqrt( ( Point1:Abscissa - Point2:Abscissa ) ^ 2 + ( Point1:Ordinate - Point2:Ordinate ) ^ 2 + ( Point1:Zcoord - Point2:Zcoord ) ^ 2 ) ? Distance( FifthPoint, SixthPoint ) This is, however, not object-oriented programming, as we could have written the same function with a not object-oriented language such as Pascal or C, passing it two structs, or records as Pascal calls them, named Point1 and Point2. It is important the fact that some data internal to the object (set by the real programmer of the thing) can't be changed by the object user. As a real life example, we can consider a car engine. The provider of the object set a number of cylinders, and we have not many chances of changing that: we've got to regard it as a constant. There is naturally a number of interesting formulas about engines that engineers use (some to be seen at http://www.thecartech.com/subjects/engine/engine_formulas.htm). For example, the one for computing the Engine Volumetric Efficiency given the volume of air taken into a cylinder and the cylinder swept volume. Here comes the importance of data hiding: nobody needs to know those informations to get his car going. Also, when someone designes an engine they probably don't expect the user to change the volumetric efficiency by operating on the engine. The same thing is obtained in object oriented programming using visibility modifiers, or access modifiers. [CREATE] CLASS <cClassName> [ FROM | INHERIT <cSuperClass1> [, ... ,<cSuperClassN>] ] [ MODULE FRIENDLY ] [ STATIC ] [ FUNCTION <cFuncName> ] [HIDDEN:] [ CLASSDATA | CLASSVAR | CLASS VAR <DataName1>] [ DATA | VAR <DataName1> [,<DataNameN>] [ AS <type> ] [ INIT <uValue> ] [[EXPORTED | VISIBLE] | [PROTECTED] | [HIDDEN]] [READONLY | RO] ] ... [ METHOD <MethodName>( [<params,...>] ) [CONSTRUCTOR] ] [ METHOD <MethodName>( [<params,...>] ) INLINE <Code,...> ] [ METHOD <MethodName>( [<params,...>] ) BLOCK <CodeBlock> ] [ METHOD <MethodName>( [<params,...>] ) EXTERN <funcName>([<args,...>]) ] [ METHOD <MethodName>( [<params,...>] ) SETGET ] [ METHOD <MethodName>( [<params,...>] ) VIRTUAL ] [ METHOD <MethodName>( [<params,...>] ) OPERATOR <op> ] [ ERROR HANDLER <MethodName>( [<params,...>] ) ] [ ON ERROR <MethodName>( [<params,...>] ) ] ... [PROTECTED:] ... [VISIBLE:] [EXPORTED:] ... [FRIEND CLASS <ClassName,...>] [FRIEND FUNCTION <FuncName,...>] [SYNC METHOD <cSyncMethod>] ENDCLASS [ LOCK | LOCKED ] Another example Copied verbatim from w:Harbour (software) #include "hbclass.ch" PROCEDURE Main() LOCAL oPerson CLS oPerson := Person():New( "Dave" ) oPerson:Eyes := "Invalid" oPerson:Eyes := "Blue" Alert( oPerson:Describe() ) RETURN CREATE CLASS Person VAR Name INIT "" METHOD New( cName ) METHOD Describe() ACCESS Eyes INLINE ::pvtEyes ASSIGN Eyes( x ) INLINE iif( HB_ISSTRING( x ) .AND. x$ "Blue,Brown,Green", ::pvtEyes := x, Alert( "Invalid value" ) )
PROTECTED:
VAR pvtEyes
ENDCLASS
// Sample of normal Method definition
METHOD New( cName ) CLASS Person
::Name := cName
RETURN Self
METHOD Describe() CLASS Person
LOCAL cDescription
IF Empty( ::Name )
cDescription := "I have no name yet."
ELSE
cDescription := "My name is: " + ::Name + ";"
ENDIF
IF ! Empty( ::Eyes )
cDescription += "my eyes' color is: " + ::Eyes
ENDIF
RETURN cDescription | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 3, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.26112860441207886, "perplexity": 3134.288169270816}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-24/segments/1590347392141.7/warc/CC-MAIN-20200527044512-20200527074512-00316.warc.gz"} |
https://www.particlebites.com/?tag=semiconductors | ## The lighter side of Dark Matter
Article title: “Absorption of light dark matter in semiconductors”
Authors: Yonit Hochberg, Tongyan Lin, and Kathryn M. Zurek
Reference: arXiv:1608.01994
Direct detection strategies for dark matter (DM) have grown significantly from the dominant narrative of looking for scattering of these ghostly particles off of large and heavy nuclei. Such experiments involve searches for the Weakly-Interacting Massive Particles (WIMPs) in the many GeV (gigaelectronvolt) mass range. Such candidates for DM are predicted by many beyond Standard Model (SM) theories, one of the most popular involving a very special and unique extension called supersymmetry. Once dubbed the “WIMP Miracle”, these types of particles were found to possess just the right properties to be suitable as dark matter. However, as these experiments become more and more sensitive, the null results put a lot of stress on their feasibility.
Typical detectors like that of LUX, XENON, PandaX and ZEPLIN, detect flashes of light (scintillation) from the result of particle collisions in noble liquids like argon or xenon. Other cryogenic-type detectors, used in experiments like CDMS, cool semiconductor arrays down to very low temperatures to search for ionization and phonon (quantized lattice vibration) production in crystals. Already incredibly successful at deriving direct detection limits for heavy dark matter, new ideas are emerging to look into the lighter side.
Recently, DM below the GeV range have become the new target of a huge range of detection methods, utilizing new techniques and functional materials – semiconductors, superconductors and even superfluid helium. In such a situation, recoils from the much lighter electrons in fact become much more sensitive than those of such large and heavy nuclear targets.
There are several ways that one can consider light dark matter interacting with electrons. One popular consideration is to introduce a new gauge boson that has a very small ‘kinetic’ mixing with the ordinary photon of the Standard Model. If massive, these ‘dark photons’ could also be potentially dark matter candidates themselves and an interesting avenue for new physics. The specifics of their interaction with the electron are then determined by the mass of the dark photon and the strength of its mixing with the SM photon.
Typically the gap between the valence and conduction bands in semiconductors like silicon and germanium is around an electronvolt (eV). When the energy of the dark matter particle exceeds the band gap, electron excitations in the material can usually be detected through a complicated secondary cascade of electron-hole pair generation. Below the band gap however, there is not enough energy to excite the electron to the conduction band, and so detection proceeds through low-energy multi-phonon excitations, with the dominant being the emission of two back-to-back phonons.
In both these regimes, the absorption rate of dark matter in the material is directly related to the properties of the material, namely its optical properties. In particular, the absorption rate for ordinary SM photons is determined by the polarization tensor in the medium, and in turn the complex conductivity, $\hat{\sigma}(\omega)=\sigma_{1}+i \sigma_{2}$ , through what is known as the optical theorem. Ultimately this describes the response of the material to an electromagnetic field, which has been measured in several energy ranges. This ties together the astrophysical properties of how the dark matter moves through space and the fundamental description of DM-electron interactions at the particle level.
In a more technical sense, the rate of DM absorption, in events per unit time per unit target mass, is given by the following equation:
$R=\frac{1}{\rho} \frac{\rho_{D M}}{m_{A^{\prime}}} \kappa_{e f f}^{2} \sigma_{1}$
• $\rho$ – mass density of the target material
• $\rho_{DM}$ – local dark matter mass density (0.3 GeV/cm3) in the galactic halo
• $m_{A'}$ – mass of the dark photon particle
• $\kappa_{eff}$ – kinetic mixing parameter (in-medium)
• $\sigma_1$ – absorption rate of ordinary SM photons
Shown in Figure 1, the projected sensitivity at 90% confidence limit (C.L.) for a 1 kg-year exposure of semiconductor target to dark photon detection can be almost an order of magnitude greater than existing nuclear recoil experiments. Dependence is shown on the kinetic mixing parameter and the mass of the dark photon. Limits are also shown for existing semiconductor experiments, known as DAMIC and CDMSLite with 0.6 and 70 kg-day exposure, respectively.
Furthermore, in the millielectronvolt-kiloelectronvolt range, these could provide much stronger constraints than any of those that currently exist from sources in astrophysics, even at this exposure. These materials also provide a novel way of detecting DM in a single experiment, so long as improvements are made in phonon detection.
These possibilities, amongst a plethora of other detection materials and strategies, can open up a significant area of parameter space for finally closing in on the identity of the ever-elusive dark matter!
References and further reading: | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 7, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8654367327690125, "perplexity": 1083.4682124849885}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": false}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-29/segments/1593655879532.0/warc/CC-MAIN-20200702142549-20200702172549-00102.warc.gz"} |
http://math.stackexchange.com/questions/159745/mathrmaut-mathbb-p-is-isomorphic-to-mathrm-aut-kt | # $\mathrm{Aut}(\mathbb P)$ is isomorphic to $\mathrm{ Aut} (k(t) )$
$\def\Aut{\mathrm{Aut}}$I want to prove that the automorphism group of $\mathbb P^1$ it's isomorphic with the Moebius transformation with coefficients over the obvious field. I proved that the automorphism of $k(t)$ are of this form, If I prove that: $$\Aut(\mathbb P)\text{ is isomorphic to }\Aut (k(t) )$$ I'll be done. How can I do it, only using basic facts?
-
What's your definition of $\mathbb{P}^1$ and what's your definition of a morphism between projective varieties? – Qiaochu Yuan Jun 18 '12 at 2:40
If $f:\mathbb P^1\to \mathbb P^1$ is your automorphism and if $f({\infty})=b\neq \infty$, consider $g(z)=\frac {1}{z-b}$.
Then $g\circ f$ sends $\infty$ to $\infty$. Thus you may assume (replacing $f$ by $g\circ f$ if necessary) that $f({\infty})={\infty}$.
You are then reduced to showing that the restricted automorphism $f\mid \mathbb A^1: \mathbb A^1 \to \mathbb A^1$ is given by $z\mapsto az+b$, which result you can probably handle. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.996009349822998, "perplexity": 162.83763103499945}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-10/segments/1394011190529/warc/CC-MAIN-20140305091950-00069-ip-10-183-142-35.ec2.internal.warc.gz"} |
https://3dprinting.stackexchange.com/questions/7943/how-does-a-3d-printer-software-firmware-work | # How does a 3D printer software/firmware work
I have been working on a printer project that basically is a 2D printer (dot matrix type). We are using solenoids as actuators to make impressions on the paper. We are now in the process of designing custom software. But a problem that we have encountered is that we have no idea how to design software as we are a bunch of beginners in this field.
An idea we are working on is based on position-acknowledge technique. In this technique the computer sends G-code to the controller. The controller after reaching the position defined in code sends an acknowledgement and the computer then sends the next signal. This is the model we are currently working on.
• Can anyone suggest any other ideas to make this work?
• Is Our approach right?
• Do 3D printers work using same technique?
• Jan 11 '19 at 10:14
You appear to be asking about rate-limiting the stream of G-code provided by the computer, but some more context in your question will help if this is not the case.
Printers tend to work in two ways.
1. Read G-code from local storage as a text file. Here, the parser/control engine is in full control.
2. Stream G-code over a serial port using an 'ack' handshake.
The reference for G-code used in 3D printing is the RepRap Wiki. Here you will find responses such as ok resend and fatal, these indicate when a previous command is processed and something else can be sent, if the previous message was identified as corrupt, or if recovery is impossible.
The basic rule for this style of handshake is that after every host to slave transaction, the host must wait for some response before sending another transaction. The slave could send either ACK responses, or other asynchronous transactions if you can design the system to avoid or not care about overrun in the slave to host direction.
When designing a handshake like this, you can consider all possible ways for something to go wrong (assume the interface is imperfect). How can you handle a request being missed and no ACK ever? When there is a timeout, can you make a 'benign' request to see if the printer is still connected, etc.
• Nicely answered! It is exactly the responses of the machine which can bug up other software, see e.g. this answer.
– 0scar
Jan 11 '19 at 10:47
3D printer firmware use gcode that is derived from CNC and no acknowledgment. They send movement commands to the stepper motors like G1 X10 Y10 to move the printhead 10 mm along the X and Y.
You could use a ready 3D printer firmware like Marlin on a 3d printer board and use the X-axis or extruder output to couple to your solenoid, sending a G1 Z0.1 or G1 E0.1, which will actuate it for a short time. You might even use E and Z on different solenoids.
Are you interested in receiving the instructions correctly, or interested in how the instructions are executed by the hardware? This answer doesn't go into the software communication between controller board and software that sends the instruction from another software/hardware platform (see this answer), this answer addresses the positioning/movement.
Most of current 3D printers do not track the position of the print head. The software instructs the head to go somewhere, but it never checks if it actually arrives at that exact position. Problems like missing steps of the stepper or skipping notches on the belt are not detected and the printer will continue thinking it has reached the position.
Skipping of belts is a mechanical issue and should not occur (nor can be detected unless there are stepper steps missed), but skipping of steps is something that can be detected by certain type of stepper drivers (trinamic). Steppers do not use a feedback loop to check the final position. Servos, opposed to steppers, use a feedback loop, and as such are able to reach the position as instructed, but this comes a an increased cost, servo's are more expensive and hence not found in most of the "cheaper" 3D printing machines.
It is up to the designer of a 3D machine to choose the motors for the positioning system, if it is not highly loaded, you go for steppers without a feedback loop, or in higher loaded machines for servo's (basically steppers with some positioning electronics for the feedback). In case of a stepper you hope that it reaches the destination you tell it to go to, for a servo, you known that it reaches that exact position.
• Note: detecting belt skipping can be detected equally: you just need a feedback sensor which include the belt in the loop. However I agree that poor quality 3D printer who usually use belts will not have this feedback. Considering ball-screw mechanisms, they just cannot skip, and also provide more rigidity. Apr 29 '20 at 7:28
The CNC system, and simplifying intentionally, is divided into several steps:
1. Acquisition of the g-code: This depends on the platform, whether is a file from an USB flash-memory, network or direct input from the operator. G-code operations needs to be buffered in a quantity enough to allow some "look-ahead" in the program.
2. Parsing of the g-code: Parsing of any formal language is based on "formal grammars" theory https://en.wikipedia.org/wiki/Formal_grammar. Fortunately, g-code is one of the simplest grammar of the Chomsky hierarchy. Language parsing is a full topic in itself, and it follows lexical, syntactical and semantical analysis.
3. Driving: It exists several different strategies:
• Open-loop vs closed loop: In closed-loop CNC, sensors provide a feedback from the movement, allowing the driver to fix deviations (e.g. no step lots). Those systems are more expensive and usually not available in cheap 3D printers. In open-loop CNC, the driver send signals and "hope" the machine will follow, this is the case of most cheap 3D-printers, where if you block the head, it will lose steps.
• Synchronous vs asynchronous (not sure about this naming): In synchronous systems, the driver send a single step for each axis each loop (one step forward, no step, or one step backward for each of the x, y, z, a... axis). In each iteration, the driver establish which steps need to be activated and send it; the speed of the movement depends on how fast this loop is performed. In Asynchronous driving, the loop run at a specific speed and apply steps as needed to correct the distance between the previous/detected position and the expected position.
Acquisition and parsing of g-code can be performed in soft real-time, however the driving needs hard real-time, which precision determine the maximum speed that your CNC can manage.
The servos/steppers usually cannot manage infinite acceleration, this is why the system needs to read g-code instructions ahead to anticipate closed angles or changes in direction. It should then reduce the indicated speed down to something which allows the next instruction.
I hope this give a quick introduction to the topic, obviously, each aspect needs further reading. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.4153657853603363, "perplexity": 1724.455627456135}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-43/segments/1634323585183.47/warc/CC-MAIN-20211017210244-20211018000244-00620.warc.gz"} |
https://doc.cgal.org/5.0/Stream_support/group__PkgStreamSupportRef.html | CGAL 5.0 - IO Streams
IO Streams Reference
Andreas Fabri, Geert-Jan Giezeman, and Lutz Kettner
All classes in the CGAL kernel provide input and output operators for IO streams. The basic task of such an operator is to produce a representation of an object that can be written as a sequence of characters on devices as a console, a file, or a pipe. In CGAL we distinguish between a raw ascii, a raw binary and a pretty printing format.
Introduced in: CGAL 1.0
BibTeX: cgal:fgk-ios-12-19b
All classes in the CGAL kernel provide input and output operators for IO streams. CGAL provides three different printing mode, defined in the enum IO::Mode, as well as different functions to set and get the printing mode.
## Enum
• CGAL::IO::Mode
## Functions
• CGAL::get_mode()
• CGAL::is_ascii()
• CGAL::is_binary()
• CGAL::is_pretty()
• CGAL::set_mode()
• CGAL::set_ascii_mode()
• CGAL::set_binary_mode()
• CGAL::set_pretty_mode()
• CGAL::operator>>()
• CGAL::operator<<()
• CGAL::iformat()
• CGAL::oformat()
## WKT I/O Functions
• CGAL::read_point_WKT()
• GCAL::read_multi_point_WKT()
• GCAL::read_linestring_WKT()
• GCAL::read_multi_linestring_WKT()
• GCAL::read_polygon_WKT()
• GCAL::read_multi_polygon_WKT()
• GCAL::read_WKT()
• CGAL::write_point_WKT()
• CGAL::write_polygon_WKT()
• CGAL::write_linestring_WKT()
• CGAL::write_multi_point_WKT()
• CGAL::write_multi_polygon_WKT()
• CGAL::write_multi_linestring_WKT()
## Classes
• CGAL::Color
• CGAL::Istream_iterator<T,Stream>
• CGAL::Ostream_iterator<T,Stream>
• CGAL::Verbose_ostream
• CGAL::Input_rep<T,F>
• CGAL::Output_rep<T,F>
## Modules
Stream Operators
## Classes
class CGAL::Input_rep< T, F >
The definition of Input_rep is completely symmetric to Output_rep. More...
class CGAL::Output_rep< T, F >
The purpose of Output_rep is to provide a way to control output formatting that works independently of the object's stream output operator. More...
class CGAL::Istream_iterator< T, Stream >
The class Istream_iterator is an input iterator adaptor for the input stream class Stream and value type T. More...
class CGAL::Ostream_iterator< T, Stream >
The class Ostream_iterator is an output iterator adaptor for the output stream class Stream and value type T. More...
class CGAL::Verbose_ostream
The class Verbose_ostream can be used as an output stream. More...
class CGAL::Color
An object of the class Color is a color available for drawing operations in many CGAL output streams. More...
## Enumerations
enum CGAL::IO::Mode
All classes in the CGAL Kernel provide input and output operators for IOStreams. More...
## Functions
IO::Mode CGAL::get_mode (std::ios &s)
returns the printing mode of the IO stream s. More...
IO::Mode CGAL::set_ascii_mode (std::ios &s)
sets the mode of the IO stream s to be the IO::ASCII mode. More...
IO::Mode CGAL::set_binary_mode (std::ios &s)
IO::Mode CGAL::set_mode (std::ios &s, IO::Mode m)
sets the printing mode of the IO stream s. More...
IO::Mode CGAL::set_pretty_mode (std::ios &s)
sets the mode of the IO stream s to be the IO::PRETTY mode. More...
bool CGAL::is_ascii (std::ios &s)
checks if the IO stream s is in IO::ASCII mode. More...
bool CGAL::is_binary (std::ios &s)
checks if the IO stream s is in IO::BINARY mode. More...
bool CGAL::is_pretty (std::ios &s)
checks if the IO stream s is in IO::PRETTY mode. More...
template<class T >
Output_rep< T > CGAL::oformat (const T &t)
Convenience function to construct an output representation (Output_rep) for type T. More...
template<class T >
Input_rep< T > CGAL::iformat (const T &t)
The definition of this function is completely symmetric to oformat().
template<class T , typename F >
Output_rep< T, F > CGAL::oformat (const T &t, F)
Convenience function to construct an output representation (Output_rep) for type T. More...
template<typename Point >
std::istream & CGAL::read_point_WKT (std::istream &in, Point &point)
read_point_WKT() fills a Point from a WKT stream. More...
template<typename MultiPoint >
std::istream & CGAL::read_multi_point_WKT (std::istream &in, MultiPoint &mp)
read_multi_point_WKT() overwrites the content of a MultiPoint with the first line starting with MULTIPOINT in the stream. More...
template<typename LineString >
std::istream & CGAL::read_linestring_WKT (std::istream &in, LineString &polyline)
read_linestring_WKT() fills a Linestring from a WKT stream. More...
template<typename MultiLineString >
std::istream & CGAL::read_multi_linestring_WKT (std::istream &in, MultiLineString &mls)
read_multi_linestring_WKT() overwrites the content of a MultiLineString with the first line starting with MULTILINESTRING in the stream. More...
template<typename Polygon >
std::istream & CGAL::read_polygon_WKT (std::istream &in, Polygon &polygon)
read_polygon_WKT() fills polygon from a WKT stream. More...
template<typename MultiPolygon >
std::istream & CGAL::read_multi_polygon_WKT (std::istream &in, MultiPolygon &polygons)
read_multi_polygon_WKT() overwrites the content of a MultiPolygon with the first line starting with MULTIPOLYGON in the stream. More...
template<typename Point >
std::ostream & CGAL::write_point_WKT (std::ostream &out, const Point &point)
write_point_WKT() writes point into a WKT stream. More...
template<typename Polygon >
std::ostream & CGAL::write_polygon_WKT (std::ostream &out, const Polygon &poly)
write_polygon_WKT() writes poly into a WKT stream. More...
template<typename LineString >
std::ostream & CGAL::write_linestring_WKT (std::ostream &out, LineString ls)
write_linestring_WKT() writes the content of ls into a WKT stream. More...
template<typename MultiPoint >
std::ostream & CGAL::write_multi_point_WKT (std::ostream &out, MultiPoint &mp)
write_multi_point_WKT() writes the content of mp into a WKT stream. More...
template<typename MultiPolygon >
std::ostream & CGAL::write_multi_polygon_WKT (std::ostream &out, MultiPolygon &polygons)
write_multi_polygon_WKT() writes the content of polygons into a WKT stream. More...
template<typename MultiLineString >
std::ostream & CGAL::write_multi_linestring_WKT (std::ostream &out, MultiLineString &mls)
write_multi_linestring_WKT() writes the content of mls into a WKT stream. More...
template<typename MultiPoint , typename MultiLineString , typename MultiPolygon >
std::istream & CGAL::read_WKT (std::istream &input, MultiPoint &points, MultiLineString &polylines, MultiPolygon &polygons)
reads the content of a WKT stream and fills points, polylines and polygons with all the POINT, MULTIPOINT, LINESTRING, MULTILINESTRING, POLYGON and MULTIPOLYGON it finds in input. More...
## ◆ Mode
enum CGAL::IO::Mode
#include <CGAL/IO/io.h>
All classes in the CGAL Kernel provide input and output operators for IOStreams.
The basic task of such an operator is to produce a representation of an object that can be written as a sequence of characters on devices as a console, a file, or a pipe. The enum Mode distinguish between three different printing formats.
In ASCII mode, numbers e.g. the coordinates of a point or the coefficients of a line, are written in a machine independent format. In BINARY mode, data are written in a binary format, e.g. a double is represented as a sequence of four byte. The format depends on the machine. The mode PRETTY serves mainly for debugging as the type of the geometric object is written, as well as the data defining the object. For example for a point at the origin with Cartesian double coordinates, the output would be PointC2(0.0, 0.0). At the moment CGAL does not provide input operations for pretty printed data. By default a stream is in Ascii mode.
CGAL::set_mode()
CGAL::set_ascii_mode()
CGAL::set_binary_mode()
CGAL::set_pretty_mode()
CGAL::get_mode()
CGAL::is_ascii()
CGAL::is_binary()
CGAL::is_pretty()
## ◆ get_mode()
IO::Mode CGAL::get_mode ( std::ios & s )
#include <CGAL/IO/io.h>
returns the printing mode of the IO stream s.
CGAL::IO::Mode
CGAL::set_mode()
CGAL::set_ascii_mode()
CGAL::set_binary_mode()
CGAL::set_pretty_mode()
CGAL::is_ascii()
CGAL::is_binary()
CGAL::is_pretty()
## ◆ is_ascii()
bool CGAL::is_ascii ( std::ios & s )
#include <CGAL/IO/io.h>
checks if the IO stream s is in IO::ASCII mode.
CGAL::IO::Mode
CGAL::set_mode()
CGAL::set_ascii_mode()
CGAL::set_binary_mode()
CGAL::set_pretty_mode()
CGAL::get_mode()
CGAL::is_binary()
CGAL::is_pretty()
## ◆ is_binary()
bool CGAL::is_binary ( std::ios & s )
#include <CGAL/IO/io.h>
checks if the IO stream s is in IO::BINARY mode.
CGAL::IO::Mode
CGAL::set_mode()
CGAL::set_ascii_mode()
CGAL::set_binary_mode()
CGAL::set_pretty_mode()
CGAL::get_mode()
CGAL::is_ascii()
CGAL::is_pretty()
## ◆ is_pretty()
bool CGAL::is_pretty ( std::ios & s )
#include <CGAL/IO/io.h>
checks if the IO stream s is in IO::PRETTY mode.
CGAL::IO::Mode
CGAL::set_mode()
CGAL::set_ascii_mode()
CGAL::set_binary_mode()
CGAL::set_pretty_mode()
CGAL::get_mode()
CGAL::is_ascii()
CGAL::is_binary()
## ◆ oformat() [1/2]
template<class T >
Output_rep CGAL::oformat ( const T & t )
#include <CGAL/IO/io.h>
Convenience function to construct an output representation (Output_rep) for type T.
Generic IO for type T.
## ◆ oformat() [2/2]
template<class T , typename F >
Output_rep CGAL::oformat ( const T & t, F )
#include <CGAL/IO/io.h>
Convenience function to construct an output representation (Output_rep) for type T.
Generic IO for type T with formatting tag.
template<typename LineString >
std::istream& CGAL::read_linestring_WKT ( std::istream & in, LineString & polyline )
#include <CGAL/IO/WKT.h>
read_linestring_WKT() fills a Linestring from a WKT stream.
The first line starting with LINESTRING in the stream will be used.
Template Parameters
Linestring must be a model of RandomAccessRange of CGAL::Point_2, and have: a function push_back() that takes a CGAL::Point_2. a function clear(), a function resize() that takes an size_type an operator[]() that takes a size_type.
Attention
Only Cartesian Kernels with double or float as FT are supported.
This function is only available with boost versions starting at 1.56.
CGAL::Point_2
Examples:
Stream_support/Linestring_WKT.cpp.
template<typename MultiLineString >
std::istream& CGAL::read_multi_linestring_WKT ( std::istream & in, MultiLineString & mls )
#include <CGAL/IO/WKT.h>
read_multi_linestring_WKT() overwrites the content of a MultiLineString with the first line starting with MULTILINESTRING in the stream.
Template Parameters
MultiLineString must be a model of RandomAccessRange of Linestring, and have: a function push_back() that takes a Linestring, a function clear(), a function resize() that takes an size_type an operator[]() that takes a size_type.
Attention
Only Cartesian Kernels with double or float as FT are supported.
This function is only available with boost versions starting at 1.56.
CGAL::Point_2
Examples:
Stream_support/Linestring_WKT.cpp.
template<typename MultiPoint >
std::istream& CGAL::read_multi_point_WKT ( std::istream & in, MultiPoint & mp )
#include <CGAL/IO/WKT.h>
read_multi_point_WKT() overwrites the content of a MultiPoint with the first line starting with MULTIPOINT in the stream.
Template Parameters
MultiPoint must be a model of RandomAccessRange of CGAL::Point_2 or CGAL::Point_3, and have: a function push_back() that takes the same point type, a function clear(), a function resize() that takes an size_type an operator[]() that takes a size_type.
Attention
Only Cartesian Kernels with double or float as FT are supported.
This function is only available with boost versions starting at 1.56.
CGAL::Point_2
CGAL::Point_3
Examples:
Stream_support/Point_WKT.cpp.
template<typename MultiPolygon >
std::istream& CGAL::read_multi_polygon_WKT ( std::istream & in, MultiPolygon & polygons )
#include <CGAL/IO/WKT.h>
read_multi_polygon_WKT() overwrites the content of a MultiPolygon with the first line starting with MULTIPOLYGON in the stream.
Template Parameters
MultiPolygon must be a model of RandomAccessRange of CGAL::General_polygon_with_holes_2, and have: a function push_back() that takes a CGAL::General_polygon_with_holes_2, a function clear(), a function resize() that takes an size_type an operator[]() that takes a size_type.
Attention
Only Cartesian Kernels with double or float as FT are supported.
This function is only available with boost versions starting at 1.56.
CGAL::General_polygon_with_holes_2
Examples:
Stream_support/Polygon_WKT.cpp.
template<typename Point >
std::istream& CGAL::read_point_WKT ( std::istream & in, Point & point )
#include <CGAL/IO/WKT.h>
read_point_WKT() fills a Point from a WKT stream.
The first line starting with POINT in the stream will be used.
Template Parameters
Point can be a CGAL::Point_2 or CGAL::Point_3.
Attention
Only Cartesian Kernels with double or float as FT are supported.
This function is only available with boost versions starting at 1.56.
CGAL::Point_2
CGAL::Point_3
template<typename Polygon >
std::istream& CGAL::read_polygon_WKT ( std::istream & in, Polygon & polygon )
#include <CGAL/IO/WKT.h>
read_polygon_WKT() fills polygon from a WKT stream.
The first line starting with POLYGON in the stream will be used.
Template Parameters
Polygon is a CGAL::General_polygon_with_holes_2.
Attention
Only Cartesian Kernels with double or float as FT are supported.
This function is only available with boost versions starting at 1.56.
CGAL::General_polygon_with_holes_2
Examples:
Stream_support/Polygon_WKT.cpp.
template<typename MultiPoint , typename MultiLineString , typename MultiPolygon >
std::istream& CGAL::read_WKT ( std::istream & input, MultiPoint & points, MultiLineString & polylines, MultiPolygon & polygons )
#include <CGAL/IO/WKT.h>
reads the content of a WKT stream and fills points, polylines and polygons with all the POINT, MULTIPOINT, LINESTRING, MULTILINESTRING, POLYGON and MULTIPOLYGON it finds in input.
Template Parameters
MultiPoint must be a model of RandomAccessRange of CGAL::Point_2 or CGAL::Point_3. MultiLineString must be a RandomAccessRange of Linestring. MultiPolygon must be a model of RandomAccessRange of CGAL::General_polygon_with_holes_2.
Attention
Only Cartesian Kernels with double or float as FT are supported.
This function is only available with boost versions starting at 1.56.
CGAL::read_linestring_WKT()
## ◆ set_ascii_mode()
IO::Mode CGAL::set_ascii_mode ( std::ios & s )
#include <CGAL/IO/io.h>
sets the mode of the IO stream s to be the IO::ASCII mode.
Returns the previous mode of s.
CGAL::IO::Mode
CGAL::set_mode()
CGAL::set_binary_mode()
CGAL::set_pretty_mode()
CGAL::get_mode()
CGAL::is_ascii()
CGAL::is_binary()
CGAL::is_pretty()
## ◆ set_binary_mode()
IO::Mode CGAL::set_binary_mode ( std::ios & s )
#include <CGAL/IO/io.h>
CGAL::IO::Mode
CGAL::set_mode()
CGAL::set_ascii_mode()
CGAL::set_pretty_mode()
CGAL::get_mode()
CGAL::is_ascii()
CGAL::is_binary()
CGAL::is_pretty()
sets the mode of the IO stream s to be the IO::BINARY mode. Returns the previous mode of s.
## ◆ set_mode()
IO::Mode CGAL::set_mode ( std::ios & s, IO::Mode m )
#include <CGAL/IO/io.h>
sets the printing mode of the IO stream s.
CGAL::IO::Mode
CGAL::set_ascii_mode()
CGAL::set_binary_mode()
CGAL::set_pretty_mode()
CGAL::get_mode()
CGAL::is_ascii()
CGAL::is_binary()
CGAL::is_pretty()
## ◆ set_pretty_mode()
IO::Mode CGAL::set_pretty_mode ( std::ios & s )
#include <CGAL/IO/io.h>
sets the mode of the IO stream s to be the IO::PRETTY mode.
Returns the previous mode of s.
CGAL::IO::Mode
CGAL::set_mode()
CGAL::set_ascii_mode()
CGAL::set_binary_mode()
CGAL::get_mode()
CGAL::is_ascii()
CGAL::is_binary()
CGAL::is_pretty()
## ◆ write_linestring_WKT()
template<typename LineString >
std::ostream& CGAL::write_linestring_WKT ( std::ostream & out, LineString ls )
#include <CGAL/IO/WKT.h>
write_linestring_WKT() writes the content of ls into a WKT stream.
Template Parameters
LineString must be a RandomAccessRange of CGAL::Point_2.
Attention
Only Cartesian Kernels with double or float as FT are supported.
This function is only available with boost versions starting at 1.56.
CGAL::Point_2
## ◆ write_multi_linestring_WKT()
template<typename MultiLineString >
std::ostream& CGAL::write_multi_linestring_WKT ( std::ostream & out, MultiLineString & mls )
#include <CGAL/IO/WKT.h>
write_multi_linestring_WKT() writes the content of mls into a WKT stream.
Template Parameters
MultiLineString must be a RandomAccessRange of LineString.
Attention
Only Cartesian Kernels with double or float as FT are supported.
This function is only available with boost versions starting at 1.56.
CGAL::write_linestring_WKT()
## ◆ write_multi_point_WKT()
template<typename MultiPoint >
std::ostream& CGAL::write_multi_point_WKT ( std::ostream & out, MultiPoint & mp )
#include <CGAL/IO/WKT.h>
write_multi_point_WKT() writes the content of mp into a WKT stream.
Template Parameters
MultiPoint must be a RandomAccessRange of CGAL::Point_2.
Attention
Only Cartesian Kernels with double or float as FT are supported.
This function is only available with boost versions starting at 1.56.
CGAL::Point_2
## ◆ write_multi_polygon_WKT()
template<typename MultiPolygon >
std::ostream& CGAL::write_multi_polygon_WKT ( std::ostream & out, MultiPolygon & polygons )
#include <CGAL/IO/WKT.h>
write_multi_polygon_WKT() writes the content of polygons into a WKT stream.
Template Parameters
MultiPolygon must be a RandomAccessRange of CGAL::General_polygon_with_holes_2.
Attention
Only Cartesian Kernels with double or float as FT are supported.
This function is only available with boost versions starting at 1.56.
CGAL::General_polygon_with_holes_2
## ◆ write_point_WKT()
template<typename Point >
std::ostream& CGAL::write_point_WKT ( std::ostream & out, const Point & point )
#include <CGAL/IO/WKT.h>
write_point_WKT() writes point into a WKT stream.
Template Parameters
Point is a CGAL::Point_2
Attention
Only Cartesian Kernels with double or float as FT are supported.
This function is only available with boost versions starting at 1.56.
CGAL::Point_2
## ◆ write_polygon_WKT()
template<typename Polygon >
std::ostream& CGAL::write_polygon_WKT ( std::ostream & out, const Polygon & poly )
#include <CGAL/IO/WKT.h>
write_polygon_WKT() writes poly into a WKT stream.
Template Parameters
Polygon must be a CGAL::General_polygon_with_holes_2
Attention
Only Cartesian Kernels with double or float as FT are supported.
This function is only available with boost versions starting at 1.56.
CGAL::General_polygon_with_holes_2 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.2471940666437149, "perplexity": 21770.627458069055}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-39/segments/1631780056297.61/warc/CC-MAIN-20210918032926-20210918062926-00533.warc.gz"} |
https://chemistry.stackexchange.com/questions/47053/how-to-calculate-an-enthalpy-change-for-this-reaction | # How to calculate an enthalpy change for this reaction
I've got an assignment to solve problem number 4 in this worksheet, that is to calculate change in enthalpy for reaction: $$\ce{CHCl3 + O -> COCl2 + HCl}$$
How do I solve it? Why is oxygen $\ce{O}$, and not $\ce{O2}$?
I figured out that, it is not a combustion reaction, as combustion of any hydrocarbon will lead to formation of $\ce{CO2}$ and $\ce{H2O}$, as per this page.
Well, what I have at the beginning is not exactly a hydrocarbon, but rather, a halogenated hydrocarbon. Yet, no water and no carbon dioxide is produced. So as I mentioned above, I consider it is not a combustion. Any thoughts on this? Could it still be a combustion? Why or why not?
When I calculate $\Delta H$ of this reaction, the total outcome depends on using reaction as it is shown in the worksheet, or correcting $\ce{O}$ to $\ce{O2}$ and balancing it. Which option, do you think, is preferable, and why?
• Also, for general reference on $\LaTeX$, check this meta post: meta.math.stackexchange.com/q/5020 – user5764 Feb 27 '16 at 20:24
• Why should be O$_2$ ? Combustion reactions are vaguely defined, but many times refers to reactions with $O_2$, I would not call this a combustion reaction but as definition is not accurate I can give strong arguments. It could be called combustion if it a fast and very exergonic reaction (I don't know this case) but it is no common to call this way reaction with radicals. I can not view the worksheet. – user1420303 Mar 3 '16 at 23:12
To preface, the reason that this is not a combustion reaction is because this is a redox reaction that occurs at room temperature. In fact, chloroform is noncombustible.
Though at first glance, this may simply appear to be an unbalanced equation that could be rewritten: $$\ce{CHCl3 + 1/2O2 -> COCl2 + HCl}$$
It is better to take it for what the question presents it as, an oxygen atom, so I would therefore recommend you to leave the equation as:
$$\ce{CHCl3 + O -> COCl2 + HCl}$$
Though $\ce{O2}$ is a pure element, and its $\Delta H^0_\mathrm f=0\:\mathrm{kJ\:mol^{-1}}$, for the atom $\ce{O}$, $\Delta H^0_\mathrm f=58.99\:\mathrm{kJ\:mol^{-1}}^{[1]}$ (provided thanks to user1420303).
To calculate $\Delta H$, the equation is: $$\Delta H=\Delta H^0_\mathrm f(\ce{COCl2}) + \Delta H^0_\mathrm f(\ce{HCl})-\Delta H^0_\mathrm f(\ce{CHCl3})-\Delta H^0_\mathrm f(\ce{O})$$
Though enthalpy is a state function, this question is asking you to calculate $\Delta H$ from a specific set of reactants, and their individual energies must be considered. There is more than just one way to calculate $\Delta H$, and an analysis of the $\Delta H^0_\mathrm f$ (the enthalpy of formation of a compound from its constituent elements) for each compound accounts for which bonds are being broken and formed, and will yield (about) the same results as a bond by bond analysis. I find this method to be preferable because it bond by bond analyses are based on average bond enthalpies, while $\Delta H^0_\mathrm f$ is often painstakingly measured for each compound, and will yield the most accurate $\Delta H$ calculation.
[1] Curtiss, L. A.; Raghavachari, K.; Redfern, P. C.; Pople, J. A. Assessment Of Gaussian-2 and Density Functional Theories for the Computation of Enthalpies of Formation. The Journal of Chemical Physics J. Chem. Phys. 1997, 106, 1063.
• delta H of formation and bond energy are two different things. One still needs to invest energy to break double bond between two oxygen atoms and this energy is not equal to zero. – Sleepy Hollow Feb 29 '16 at 17:19
• Delta H of reaction = sum of bonds energy for bonds broken - sum of bonds energy for bonds made. There is no delat H of formation in this equation. – Sleepy Hollow Feb 29 '16 at 17:23
• Regardless of what bonds are broken in a specific reaction, enthalpy is a state function. An analysis of the $\Delta H^0_f$ for each compound (which tells you the enthalpy of formation from the constituent elements of each molecule) will yield the same results as calculating which specific bonds are being broken and formed. There is more than just one way to calculate $\Delta H$. – ringo Feb 29 '16 at 17:25
• This answer is not correct in that $O$ is not the same that $(1/2)O_2$ – user1420303 Mar 3 '16 at 23:04
• @user1420303 Are you trying to say half of a diatomic molecule isn't a single atom? If so I don't know what to tell you. Either way, it's only a stoichiometric concept. In the mechanism for this reaction, the $\pi$-bond in diatomic oxygen is homolytically split, and then reacts via a chain radical mechanism. Never in this reaction does there exist a true oxygen atom. – ringo Mar 3 '16 at 23:47
Let it remain as $\ce{O}$. Using $\ce{O}$, the bonds that are formed are:
1. 1 $\ce{C=O}$ bond
2. 1 $\ce{H-Cl}$ bond
The bonds that are broken are,
1. 1 $\ce{C-H}$ bond
2. 1 $\ce{C-Cl}$ bond
Using the above information and the formula given in your assignment,
$$\Delta_\mathrm{R} H=[\text{energy used for breaking bonds}]-[\text{energy used for forming bonds}]$$
you can find the enthalpy change.
Yes. The reaction given is not a combustion reaction. However, it is not necessary that the products are carbon dioxide and water vapour.
One interesting thing that you can note is that, chloroform stored in presence of oxygen will slowly convert to phosgene and this can take place at room temperature.
Anyways, the main intention of the question is simple and only asks you to calculate the enthalpy change.
• I don't think $\ce{C=O} \approx 2(\ce{C-O})$. – SendersReagent Feb 29 '16 at 16:44
• Eh... They're not too far off. – SendersReagent Feb 29 '16 at 16:48
• @DGS my mistake. I thought $\ce{C = O}$ bond energy was not given. So I thought I could make an approximation :) – Aditya Dev Feb 29 '16 at 16:58
How do I solve it? Why is oxygen O, and not O2?
Because $\ce{O2}$ does not react.$\ce{O2}$ gets dissociated into $\ce{2O}$ and then this oxygen atoms reacts.Remember about bond dissociation enthalpy?
Diatomic molecule is one that only contains two atoms. They could be the same (for example, Cl2) or different (for example, HCl). The bond dissociation enthalpy is the energy needed to break one mole of the bond to give separated atoms - everything being in the gas state.
• That is exactly my point. If I use O2, I have to consider energy I have to use for bond breaking in O2, Outcome (in terms of endothermic or exothermic) is different, if I use it with O, and if I use it with O2, and then balance equation. – Sleepy Hollow Feb 29 '16 at 17:25 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.6951180100440979, "perplexity": 747.9417466235878}, "config": {"markdown_headings": true, "markdown_code": false, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-43/segments/1570986726836.64/warc/CC-MAIN-20191020210506-20191020234006-00046.warc.gz"} |
https://math.stackexchange.com/questions/384450/what-does-the-notation-twoheadrightarrow-mean | # What does the notation $\twoheadrightarrow$ mean?
I don't know what this double-arrow $\twoheadrightarrow$ means!
• sometimes it means surjective – Mud May 7 '13 at 13:24
• It largely depends on the context and the author. I've seen it used for several things, but most often to denote a surjective mapping. – Zéychin May 7 '13 at 14:23
A surjective function is a function whose image is equal to its codomain. Equivalently, a function f with domain $X$ and codomain $Y$ is surjective if for every $y$ in $Y$ there exists at least one $x$ in $X$ with $f(x)=y$. Surjections are sometimes denoted by a two-headed rightwards arrow, as in $f : X \twoheadrightarrow Y,\;$ [Boldface mine.] | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9476209282875061, "perplexity": 220.5761598555961}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-05/segments/1579250606226.29/warc/CC-MAIN-20200121222429-20200122011429-00007.warc.gz"} |
http://mathhelpforum.com/business-math/274611-please-help-i-m-new-microeconomics-can-t-get-past-problem.html | Consider the following data for the nation of inflatuenza
2001 Working Afe Population 18.10 Million
2001 Consumer Price Index (1996=100) 137.4
2001 Employed 10.06 Million
2000 Consumer Price Index (1996=100) 121.8
2001 Participation Rate 60.27%
a. Compute the 2001 Labour Force for Inflatuenza
b. Compute the 2001 Unemployment Rate for Inflatuenza
c. Compute the 2001 Inflation Rate for Inflatuenza
I'm tearing my hair out trying to figure this out, anybody can help? I'm very new to macroeconomics
Attached Thumbnails
Hint - Try coming up with a definition mathematically before answering this.
The labour force usually has the number of people employed [but depending on the definition it may include more or less].
In other words, if you want help you had better include definitions for "Labour Force", "Unemployment Rate", and "Inflation Rate".
This is, after all, a mathematics help forum and those are not mathematical tems! | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8207119107246399, "perplexity": 4280.157843757854}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-34/segments/1534221219242.93/warc/CC-MAIN-20180822010128-20180822030128-00358.warc.gz"} |
https://netz-werker.blogspot.com/2016/06/trilemma-of-complex-network-analysis.html | ## Saturday, June 4, 2016
### Note 1: Trilemma of Complex Network Analysis
I started my doctoral studies over 13 years ago - and it seemed that complex network analysis is the framework to use whenever you can define a meaningful relationship between a set of entities: proteins interacting with each other, airports connected by scheduled flights, people connected by pressing a 'retweet' button in their browser to express their opinion on someone else's tweet.
The main hypothesis and first Note in my upcoming book "Network Analysis Literacy" (Zweig2016) condenses my findings of these more than a dozen years:
Note 1. "To interpret the values of a distance-based measure, the way of calculating the distance must be matched to the process of interest. To interpret any walk-based measure, the set of walks used by the measure needs to be closely adapted to the process. (K.A. Zweig: Network Analysis Literacy, (c) by Springer Verlag, Heidelberg, to be published)
It refers to the so-called trilemma of complex network analysis, a term Isadory Dorn, Andreas Lindenblatt, and I developed in 2012 (Dorn2012). It summarizes the interdependencies between raw data, relationship of interest, network process of interest, research question, and methods used to analyze the latter. The research question determines a network process that uses a (set of) relationships to exert indirect effects on entities connected to each other by this relationship. By representing this relationship as a complex network, all classic network analytic methods can be applied---in principle.
Stephen P. Borgatti was the first to show that centrality indices, one of the most classic and widely used set of methods, have an inbuilt model of a network process they are associated with (Borgatti2005): they secretely determine the paths on which indirect effects are induced! Take your beloved betweenness centrality, defined as follows:
where $\delta_v(s,t)$ refers to the number of shortest paths between s and t, containing v, and $\delta(s,t)$ refers to the number of all shortest paths between s and t. There will be another dedicated blog entry to the implicit assumptions the betweenness centrality makes, but here it suffices to say that it assumes the following: all entities want to interact with each other in the same intensity (all pairs of s and t are treated equally) and all of them interact on shortest paths.
If your network process of interest does not follow these two assumptions, the betweenness centrality might not be the best centrality index to answer your research question.
This is just the first example of how network analysis literacy, e.g., knowing the implicit models behind your favourite network analytic measure or the relationship between research question, network process, and relationship, may help you to make well-grounded choices,
References:
(Borgatti2005) Borgatti, S. P.: "Centrality and Network Flow", Social Networks, 2005, 27, 55-71
(Dorn2012) Dorn, I.; Lindenblatt, A. & Zweig, K. A.: "The Trilemma of Network Analysis", Proceedings of the 2012 IEEE/ACM international conference on Advances in Social Network Analysis and Mining, Istanbul, 2012
(Zweig2016) Katharina A. Zweig: Network Analysis Literacy, ISBN 978-3-7091-0740-9, Springer Vienna, publication expected Dec 2016 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.65810626745224, "perplexity": 1675.869552710772}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-43/segments/1539583511365.50/warc/CC-MAIN-20181018001031-20181018022531-00048.warc.gz"} |
https://stevenallen.dev/posts/chestertons_fence/ | ## The “why” of code
A while back, some (way smarter than me) guy named G. K. Chesterton wrote this:
In the matter of reforming things, as distinct from deforming them, there is one plain and simple principle; a principle which will probably be called a paradox. There exists in such a case a certain institution or law; let us say, for the sake of simplicity, a fence or gate erected across a road. The more modern type of reformer goes gaily up to it and says, “I don’t see the use of this; let us clear it away.” To which the more intelligent type of reformer will do well to answer: “If you don’t see the use of it, I certainly won’t let you clear it away. Go away and think. Then, when you can come back and tell me that you do see the use of it, I may allow you to destroy it.”
Now, Chesterton was originally speaking of the Catholic Church. He may not have been so quick to jump to their defence if he had the chance to read the Boston Globe’s excellent journalism on the topic, but his point still stands. In order to effectively remove or change something, you first need to understand why it’s there.
### Somnambular development methodology
of, relating to, or characterized by actions conducted during sleep
First step in understanding the “why” beind a piece of code is acknowledging that the people who wrote it were not practicing the somnambular development methodology (ie: literally coding in their sleep). It did not spring from the aether fully-formed, in some divine computational intervention. The original developers did not write it just to make your life miserable. They had reasons. Those reasons might no longer be valid, or relevant. Or they might have been wrong and irrelevant from the beginning. But there was a reason. You owe it to your colleagues, the original developers, and to yourself to find out what it was.
Every other developer who worked on this was a moron
###### - Somebody taking aim at their foot with a shotgun
I’ve been guilty of tearing down fences and insulting the fence builders without stopping to think about the “why”. This is dangerous levels of arrogance. Yes, sometimes I was simply a better developer (though not as often as I’d like to believe). And yes, sometimes there simply was no good reason why a piece of code existed in the codebase – “I copied and pasted it from stackoverflow” is distressingly common. But more often than not, there were actual reasons why a piece of code existed when it seemed to serve no rational purpose.
### A cautionary tale
One time, I was working on a piece of code I had inherited from a developer who had moved onto greener pastures before I arrived. The codebase was a mess. I chuckled and reveled in my superiority, secure in the knowledge that had I been the solo dev working on this, it would have been much better.
Then I came across a particularly gnarly piece of code that did… well, I still have no idea WTF it did. It didn’t seem to be referenced anywhere, so I deleted it.
All hell broke loose.
Turns out it was responsible for something. The site no longer loaded. No assets, no database connection, no response other than generic 500 errors. Even robots.txt would refuse to load.
Feeling “superior” won’t keep production from going down, and won’t make the post-mortem meeting with the CEO any easier.
### This is why comments exist
This is what code comments are actually for. Forget the “good code is self-commenting”. That’s simply not true. The “what” of good code can be self-explanatory. The “why”, however, is often impossible to discerne. Yes, I can see that this piece of regex is looking for occurances of the word “dicksissel”, but why does the code care? Help any damn, arrogant fool who might wander by later and be tempted to remove or change what you’ve built by explaining in the code why you wrote it in the first place.
You never know - a year from now, you might looking at some piece of nonsense and cursing the absolute stupidity of whatever moron who wrote this indecipherable… oh shit, is that my name on the git blame?
Steven Allen is a software developer with over ten years of experience.
He's seen many companies fail. Don't be one of them. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.2399425506591797, "perplexity": 1618.1280278358552}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-10/segments/1581875141396.22/warc/CC-MAIN-20200216182139-20200216212139-00308.warc.gz"} |
https://www.physicsforums.com/threads/dimensional-analysis-energy-transfer.915695/ | Dimensional analysis: Energy Transfer
Tags:
1. May 25, 2017
HAYAO
1. The problem statement, all variables and given/known data
There is a paper in 1973:
T. Kushida, "Energy Transfer and Cooperative Optical Transitions in Rare-Earth Doped Inorganic Materials I. Transition Probability Calculation", J. Phys. Soc. Jpn. 1973, 34, 1318-1326. DOI: http://dx.doi.org/10.1143/JPSJ.34.1318
that explains the multipole-multipole energy transfer probability.
I need help with dimensional analysis of the following equation in this paper that looks EXACTLY like this:
$\bar{P}_{AB}^{(dd)} = \frac{1}{(2J_{a}+1)(2J_{b}+1)}\left ( \frac{2}{3} \right )\left ( \frac{2\pi }{\hbar} \right )\left ( \frac{e^{2}}{R^{3}} \right )^{2}\left [ \sum_{\lambda }^{ } \Omega _{A\lambda }\left \langle J_{a}\left \| U^{(\lambda )} \right \| J_{a}' \right \rangle^{2}\right ]\left [ \sum_{\lambda }^{ } \Omega _{B\lambda }\left \langle J_{b}\left \| U^{(\lambda )} \right \| J_{b}' \right \rangle^{2}\right ]S$
here,
$\bar{P}_{AB}^{(dd)}$: Dipole-dipole energy transfer probability. Unit: $[s^{-1}]$
$J_{a}$: Total angular momentum quantum number at state a of specie A. No unit.
$J_{b}$: Total angular momentum quantum number at state b of specie B. No unit.
$\hbar$: Reduced Planck constant. Unit: $[J s]$
$e$: Elementary charge. Unit: $[C]$
$R$: Distance between specie A and B. Unit: $[m]$
$\Omega _{A\lambda }$: Scaling parameter for specie A. $\lambda$ denotes tensor rank. Unit: $[m^{2}]$
$\left \langle J_{a}\left \| U^{(\lambda )} \right \| J_{a}' \right \rangle$: Reduced matrix element of $J_{a}\rightarrow J_{a}'$ transition of specie A. $\lambda$ denotes tensor rank. Unit: $[-]$
$\Omega _{B\lambda }$: Scaling parameter for specie B. $\lambda$ denotes tensor rank. Unit: $[m^{2}]$
$\left \langle J_{b}\left \| U^{(\lambda )} \right \| J_{b}' \right \rangle$: Reduced matrix element of $J_{b}\rightarrow J_{b}'$ transition of specie B. $\lambda$ denotes tensor rank. Unit: $[-]$
$S$: Spectral overlap integral of A and B. Unit: $[m]$
After dimensional analysis of the right side of the equation, it did not match with the unit on the left side of the equation.
2. Relevant equations
Dimensional analysis:
$\frac{1}{J\cdot s} \cdot \left ( \frac{C^{2}}{m^{3}} \right )^{2}\cdot m^{2}\cdot m^{2}\cdot m$
3. The attempt at a solution
$\frac{1}{J\cdot s} \cdot \left ( \frac{C^{2}}{m^{3}} \right )^{2}\cdot m^{2}\cdot m^{2}\cdot m$
$= \frac{C^{4}}{J\cdot s\cdot m}$
$= \frac{A^{4}\cdot s^{4}}{kg\cdot m^{2}\cdot s^{-2}\cdot s\cdot m}$
$= \frac{A^{4}\cdot s^{5}}{kg\cdot m^{3}}$
I broke them all down into SI units, but I have no idea how this is going to be $s^{-1}$. I think I am making a careless or fundamental mistake here, but I just can't figure it out. What do you guys think?
Thank you
2. May 25, 2017
I think the units could be cgs so that $e^2/r$ has units of energy. Meanwhile, it looks a lot like an application of Fermi's golden rule which needs a factor $\rho_f$, which is the density of final states per unit energy interval. Suggestion would be to look at Fermi's Golden Rule (google it) and see that it is dimensionally correct=then try to compare it to what this author has computed. $\\$ Editing: Also might his $P_{AB}$ refer to energy/unit time?
Last edited: May 25, 2017
3. May 25, 2017
HAYAO
Thank you Charles.
I actually already tried cgs just in case, but this was what I got:
$\frac{1}{J\cdot s} \cdot \left ( \frac{\left (cm^{\frac{3}{2}}\cdot g^{\frac{1}{2}}\cdot s^{-1} \right )^{2}}{m^{3}} \right )^{2}\cdot m^{2}\cdot m^{2}\cdot m$
$= \frac{\left ( cm^{3}\cdot g\cdot s^{-2} \right )^{2}}{J\cdot s\cdot m}$
$= \frac{cm^{6}\cdot g^{2}\cdot s^{-4}}{kg\cdot m^{2}\cdot s^{-2}\cdot s\cdot m}$
$= \frac{10^{-12}\cdot m^{6}\cdot 10^{-6}\cdot kg^{2}\cdot s^{-3}}{kg\cdot m^{3}}$
$= 10^{-18}\cdot m^{3}\cdot kg\cdot s^{-3}$
It didn't work.
Yes, the equation is derived from Fermi's golden rule. However, the $\rho_f$ is included as the spectral overlap integral $S$, so I do not believe we have to worry about that.
The rate is supposed to be events/unit time. The author implicitly says so, and so does other papers (O.L. Malta, J. Non-Cryst. Solids 2008, 354, 4770-4776).
Last edited: May 25, 2017
4. May 25, 2017
haruspex
Ithink it fairly clear there's an ε0 missing. Are you saying that the cgs units are so arranged that this takes the value 1? If so, you may be right, I am not familiar with it.
Either way, you do get to turn $e^2/r$ into dimensions of energy. Working that through, I get, for the whole expression, energy x distance / time. So even interpreting PAB as energy/time there is a spare length dimension.
I tried looking up spectral overlap integral, but cannot find anything online which makes it clear what dimension that should have. I found an integral with λ4.dλ in it, and nothing obvious to cancel all those extra length dimensions, so I gave up.
5. May 25, 2017
I tried to look up the O.L. Malta paper you cited, but unfortunately they are wanting \$35.95 for the pdf.
6. May 25, 2017
HAYAO
Yes, which is also what I got above. I don't understand...
Well the integral part in the above equation comes from the final density of states in the Fermi's Golden Rule. The unit for that is number of states/unit energy. Unit energy can be expressed in wavenumber [cm-1], so that makes the density of state with an unit of [cm]. The spectral overlap you presented there comes from FRET, but there are a lot of things going on before that equation is derived. I am not sure if it is the same spectral overlap defined in the paper above. In the paper above, the spectral overlap is explicitly in form of inverse energy in wavenumbers so [cm] as well.
7. May 25, 2017
haruspex
Sure, but that's the sort of thing that breaks dimensional analysis. The connection is via the factor hc, which has dimension.
If we introduce the missing ε0 and stick with states/unit energy instead of converting to states*wavenumber I think you will find the dimensionality of the expression reduces to just 1/time, as you originally expected.
8. May 26, 2017
HAYAO
Okay guys, I've had some help from Charles and tried solving it all in CSG unit system. I think I've got it. Here it is (I've abbreviated scaling such as 102 in changing from m to cm):
$\frac{1}{cm^{2}\cdot g\cdot s^{-2}\cdot s}\cdot \left ( \frac{\left ( cm^{\frac{3}{2}}\cdot g^{\frac{1}{2}}\cdot s^{-1} \right )^{2}}{cm^{3}} \right )^{2}\cdot cm^{2}\cdot cm^{2}\cdot \frac{1}{cm^{2}\cdot g\cdot s^{-2}}$
$= \frac{1}{cm^{2}\cdot g\cdot s^{-2}\cdot s}\cdot \left ( \frac{ cm^{3}\cdot g\cdot s^{-2}}{cm} \right )^{2}\cdot \frac{1}{cm^{4}}\cdot cm^{2}\cdot cm^{2}\cdot \frac{1}{cm^{2}\cdot g\cdot s^{-2}}$
$= \frac{1}{cm^{2}\cdot g\cdot s^{-2}\cdot s}\cdot \left ( cm^{2}\cdot g\cdot s^{-2}\right )^{2}\cdot \frac{1}{cm^{2}\cdot g\cdot s^{-2}}$
$= \frac{\left ( cm^{2}\cdot g\cdot s^{-2}\right )^{2}}{\left ( cm^{2}\cdot g\cdot s^{-2}\right )^{2} s}$
$= s^{-1}$
Looks like it works! Thank you guys!
Last edited: May 26, 2017
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Similar Discussions: Dimensional analysis: Energy Transfer | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 2, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9622612595558167, "perplexity": 965.144921064933}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-34/segments/1502886108709.89/warc/CC-MAIN-20170821133645-20170821153645-00695.warc.gz"} |
https://socratic.org/questions/562cf481581e2a5240784aec | Chemistry
Topics
# Where does the maximum electron density occur for 2s and 2p orbitals in hydrogen atom?
Dec 28, 2015
For hydrogen, we have to use spherical harmonics, so our dimensions are written as $\left(r , \theta , \phi\right)$. The wave function is defined as follows, via separation of variables:
$\textcolor{g r e e n}{{\psi}_{n l {m}_{l}} \left(r , \theta , \phi\right) = {R}_{n l} \left(r\right) {Y}_{l}^{{m}_{l}} \left(\theta , \phi\right)}$
${R}_{n l} \left(r\right)$ is the radial component of the wave function ${\psi}_{n l {m}_{l}} \left(r , \theta , \phi\right)$, ${Y}_{l}^{{m}_{l}} \left(\theta , \phi\right)$ is the angular component, $n$ is the principal quantum number, $l$ is the angular momentum quantum number, and ${m}_{l}$ is the projection of the angular momentum quantum number (i.e. $0 , \pm l$). The wave function represents an orbital.
If you don't understand all of that, that's fine; it was just for context.
To get the maximum electron density, you have to look at probability density curves.
If we plot $4 \pi {r}^{2} {R}_{n l} {\left(r\right)}^{2}$ against $r$, we get the probability density curves for an atomic orbital.
The $2 s$ orbital's plot looks like this:
From this, you can tell that the maximum electron density occurs near $5 {a}_{0}$ (with ${a}_{0} \approx 5.29177 \times {10}^{- 11} \text{m}$, the Bohr radius) from the center of the atom, and $4 \pi {r}^{2} {R}_{20} {\left(r\right)}^{2}$ is about $2.45$ or so.
From this similar diagram, we can compare the $2 s$ with the $2 p$ orbital:
Here, you should see that the $2 p$ orbital has a maximum electron density near about $4 {a}_{0}$ from the center of the atom, and the value of $4 \pi {r}^{2} {R}_{21} {\left(r\right)}^{2}$ is perhaps around $2.5$.
This should make more sense once you realize what the probability density plots of the $2 s$ and $2 p$ orbitals look like:
2s
2p
"The density of the [dark spots] is proportional to the probability of finding the electron in that region" (McQuarrie, Ch. 6-6). | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 24, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9825673699378967, "perplexity": 227.56469533003332}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-43/segments/1570987787444.85/warc/CC-MAIN-20191021194506-20191021222006-00487.warc.gz"} |
https://www.bradford-delong.com/2011/01/page/2/ | ## Short Answers to Simple Questions: Affordable Care Act Edition
Me: So Chief Medicare Actuary Richard Foster's position is that repealing the Affordable Care Act will not increase the deficit because if the Republicans don't repeal it now some other congress will repeal the deficit-reducing parts of it later?
Respected Real Health Care Expert: Yes.
## Paul Van de Water on Budget Arithmetic:
PVdW:
Testimony: Paul Van de Water: The Medicare actuary has raised questions about the sustainability of one particular category of Medicare savings in health reform — the reductions in payment updates for most providers to reflect economy-wide gains in productivity. Although these concerns deserve a serious hearing, other experts see more room to extract efficiencies and improve productivity in the health care sector. Notably, the Medicare Payment Advisory Commission (MedPAC), Congress’s expert advisory body on Medicare payment policies, generally expects that Medicare should benefit from productivity gains in the economy at large. MedPAC finds that hospitals with low Medicare profit margins often have inadequate cost controls, not inadequate Medicare payments.
Because the productivity adjustments are now law, Congress would have to pass a new law to stop them from taking effect. Under the statutory pay-as-you-go rules, that future legislation would have to be paid for, so that it didn’t increase the deficit....
[B]oth CBO and the Medicare actuary have always assumed [in the past] in their projections that the laws of the land will be implemented, rather than hazard guesses about how future Congresses might change those laws.... Gail Wilensky, who ran Medicare under President George H.W. Bush, has expressed it this way: “It would be very hard to know what you would use if you didn’t use current law — whose view you would use.”...
Bringing deficits under control will require making difficult trade-offs and tough political decisions on both taxes and spending, especially for health care. If we can’t count any provision that is controversial and might later be changed, we would have to conclude that neither the Bowles-Simpson proposals, the Rivlin-Domenici plan, nor Congressman Ryan’s Roadmap would really reduce the deficit. In fact, if we can’t count any provision that a later Congress might reverse, we can’t [ever] do serious deficit reduction...
## Department of "Huh?": Republicans Are Making a Big Fuss About How Medicare Actuary Rick Foster's View of the Affordable Care Act Differs from that of Doug Elmendorf
But I don't see it. I really don't see it.
Here is the CBO score of the Affordable Care Act:
Here is Medicare actuary Richard Foster's score of the Affordable Care Act:
These look like very much the same numbers--except that Foster's table is missing the "other provisions [of the ACA] affecting revenues" line.
Foster is marginally less optimistic about the Affordable Care Act than Doug Elmendorf and other economists like me are. Actuaries like Foster tend to assume that people do not change their behavior in response to incentives, hence we economists view their estimates with enormous skepticism.
Foster's big complaint with ACA is not that the policies won't reduce costs but rather that Congress will repeal the policies that save costs: that they are not "sustainable":
Compared to prior law, the level of total national health expenditures is estimated to be higher through 2019 under the Affordable Care Act, but two particular provisions of the legislation would help reduce NHE growth rates after 2016. Specifically, the productivity adjustments to most Medicare payment updates... the excise tax on high-cost employer health plans....
Although these growth rate differentials are not large, over time they would have a noticeable downward effect on the level of national health expenditures. Such an outcome, however, would depend critically on the sustainability of both provisions. As discussed previously, the Medicare productivity adjustments could become unsustainable even within the next 10 years, and over time the reductions in the scope of employer-sponsored health insurance could also become an issue. For these reasons, the estimated reductions in NHE growth rates after 2016 may not be fully achievable."
To say that the Affordable Care Act will in the end not reduce costs because doctors will successfully lobby Congress to repeal some of its provisions in order to make their incomes from Medicare grow more rapidly than the ACA permits might welk be true.
But I don't think that is an actuarial judgment.
And if it were one would have expected doctors to lobby Congress not to pass the ACA in the first place.
## Aaron Carroll on Being a Doctor
Aaron:
Health care from the heart – my response: When I think about being a doctor, I almost always go back to residency.... I... know those who remember fondly their days as residents, being in the trenches and completely immersed in clinical care. I was not one of those people.... I didn’t hate residency because of the hours, although they were terrible. I didn’t hate the pay. I didn’t hate being overworked or underappreciated. I didn’t hate patients or the people I worked with. I hated the system. More specifically, I hated being a doctor in the system.
I just finished Atul Gawande’s latest masterpiece. I am rarely so jealous of anyone as I am of him and his skill right now. He brought it all back for me. I can tell you many horror stories of those three years in Seattle. But ask me to rank the top few, and this one inevitably comes to the top:
I was on a rotation in the Neonatal Intensive Care Unit (NICU), where babies who are born prematurely or really sick are cared for. A couple came in with a midwife after a way-too-long and rather botched attempt at a home delivery. As soon as they arrived, we knew things were not going to go well. The baby was born in extreme distress. It appeared to be septic, or massively infected. Initial vital signs looked really bad. And then things got worse. One by one, the baby’s systems seemed to shut down. He couldn’t breathe on his own, so we put in a breathing tube. Then his heart started to fail, so we put lines into his umbilical cord to pump in medications. His lungs collapsed, so we put in tubes into his chest to help them reinflate. While another doctor and I struggled to keep all this going, I listened as, right behind me, the doctors in charge sounded downright optimistic to the parents, who were, understandably, a mess. They could not imagine how things had gone wrong so fast. They wanted to hear good news. No one seemed to be able to tell them the truth. They were given messages of hope, and they told us to do everything. That’s what we do in medicine. That’s especially what we do in the NICU. They left to go home and get clothes and supplies. Everyone dispersed.
So I was alone with this baby. It was small and blueish and had an ungodly number of devices and tubes coming out of it. I was 26, depressed, and I started to cry. The baby never moved. His heart would slow down, and I’d up his meds. His heart rate would come back up until it didn’t, and then it would drop again. So I upped the meds some more. I don’t know how long this went on. I didn’t eat, I didn’t go to the bathroom, I didn’t talk to anyone. I just stood and watched. Eventually, the ventilator stopped getting the job done, so we had to put the baby on an oscillator. Basically, instead of giving normal breaths, this machine shoves tiny amounts of air in and out really fast. It sometimes works when other things fail. It was loud, noisy, and made the baby shake. I don’t think he noticed. Things slowly got worse. Nothing was working, and every vital sign was heading downwards. As instructed, I just kept adding stuff to keep him alive. But deep down inside, I started to think that what I was doing was wrong. Not incorrect — wrong. I wondered if I was hurting the baby. I just wanted him to be at peace. And, for a moment, I wanted the baby to die.
I don’t like to think about it. I try not to. Ever. But it happened.
Not long after, nothing I was doing was working. I called in the doctors in charge, and they agreed. They asked where the parents were. It suddenly dawned on me that they hadn’t yet returned. We called them, and they were shocked to hear how bad things were. After all, those same doctors had told them things were going to be OK.
They rushed back as fast as they could. They didn’t make it in time.
I thought I would post a piece of Gawande’s article and talk about how we completely screw up end-of-life care. I thought I would make a comment about how we spend too much money or waste resources. I thought I would talk about tradeoffs and better choices. But I can’t. Partly because I can’t do his work justice, and partly because this is an issue where deep down inside I think we are doing a ton of harm. Full stop.
I went home that night and bawled uncontrollably. This kind of thing happened all too often. I toyed with the idea of getting out. I even prepared some resumes to send off to companies outside of medicine.
But, some time later, I found myself back in the NICU. A similar situation was occurring. This time, though, the doctor in charge handled everything differently. She spoke to the patients honestly and in a completely different tone. She asked the parents what they wanted out of the short time they might have with their baby.
They cried at first, but then they stopped. They cleaned the baby up and dressed him in clothes his grandparents had bought. And they took him out.
They were gone for a few hours, and then they came back. They allowed us to give the baby drugs to comfort him. They held him, as a family, as he quietly passed.
I remember quite clearly his sister was in the room. She was about six. I asked her how they had spent the day. She told me how they had taken the baby to the park to see the water. They had brought him to family members so everyone could hold him. They showed him the sun and let him lay in the grass and let a dog lick his face. Her mother was listening in at the end, and somehow smiling.
Some months later, I ran into the mother in a different part of the hospital. She remembered me, and thanked me for all I had done. I remarked that I hadn’t done much; they had cared for the baby.
“No,” she replied. “Without all of you, he never would have known what chocolate ice cream tastes like.”
I spent four years in medical school learning how the body works, how it can break down, and how to repair it. I spent three more learning how to give the right drugs and do the right procedures to fight illness. And in all the time I’ve been a doctor, I honestly don’t know if I’ve ever done any more good than helping to stop the system so that baby, and that family, could share some ice cream...
## Sigh
All statistics around Christmastide are shaky because of the unreliability of the seasonal adjustment factors. But this is not good news:
Calculated Risk: Weekly Initial Unemployment Claims increase sharply to 454,000: The DOL reports on weekly unemployment insurance claims:
In the week ending Jan. 22, the advance figure for seasonally adjusted initial claims was 454,000, an increase of 51,000 from the previous week's revised figure of 403,000. The 4-week moving average was 428,750, an increase of 15,750 from the previous week's revised average of 413,000. Click on graph for larger image in new window.
This graph shows the 4-week moving average of weekly claims for the last 10 years. The dashed line on the graph is the current 4-week average. The four-week average of weekly unemployment claims increased this week by 15,750 to 428,750...
## California School Fundraisers Are Not What They Used to Be...
In the inbox:
LPIE Crap Feed is SOLD OUT! Thank you for the overwhelming response...
## David Axelrod Is Not Making Sense
And Matthew Yglesias is unhappy:
The Eternal Mystery: I just got out of a meeting in the West Wing between David Axelrod and a few progressive writers and . . . well . . . I don’t have a ton to report.
An awful lot of progressive dialogue with the administration just keeps coming around to the same one point. According to the Obama administration the nation’s fiscal problem is in the long term. According to the Obama administration the nation’s fiscal problem is mostly due to entitlements. And according to the Obama administration in the short-term there’s a large output gap. So why a short-term discretionary spending freeze? Well on the merits there’s just no good reason you can give. The logic is clearly political. So, fine, politics is part of governing. But the White House’s belief that a strategy of unilateral preemptive concessions is a smart approach to legislative negotiations is as deeply held as it is difficult to understand. When has this worked? What has it helped achieve?...
I guess the thing to say is that as best I can tell the people working in the Obama administration are smart people who understand the fiscal policy situation perfectly well. That's a huge step forward relative to a lot of other people in Washington. But understanding is only as useful as your tactical approach lets it be, and I'm very skeptical on this front.
## Dear Gmail:
Messages from Twitter saying that so-and-so is now following me are not important messages.
Thank you.
## Ulysses S. Grant on the Secession of Texas
Via T-Nehisi Coates, U.S. Grant:
U.S. Grant: Doubtless the founders of our government, the majority of them at least, regarded the confederation of the colonies as an experiment. Each colony considered itself a separate government; that the confederation was for mutual protection against a foreign foe, and the prevention of strife and war among themselves. If there had been a desire on the part of any single State to withdraw from the compact at any time while the number of States was limited to the original thirteen, I do not suppose there would have been any to contest the right, no matter how much the determination might have been regretted. The problem changed on the ratification of the Constitution by all the colonies; it changed still more when amendments were added; and if the right of any one State to withdraw continued to exist at all after the ratification of the Constitution, it certainly ceased on the formation of new States, at least so far as the new States themselves were concerned. It was never possessed at all by Florida or the States west of the Mississippi, all of which were purchased by the treasury of the entire nation. Texas and the territory brought into the Union in consequence of annexation, were purchased with both blood and treasure; and Texas, with a domain greater than that of any European state except Russia, was permitted to retain as state property all the public lands within its borders.
It would have been ingratitude and injustice of the most flagrant sort for this State to withdraw from the Union after all that had been spent and done to introduce her; yet, if separation had actually occurred, Texas must necessarily have gone with the South, both on account of her institutions and her geographical position. Secession was illogical as well as impracticable; it was revolution. Now, the right of revolution is an inherent one. When people are oppressed by their government, it is a natural right they enjoy to relieve themselves of the oppression, if they are strong enough, either by withdrawal from it, or by overthrowing it and substituting a government more acceptable. But any people or part of a people who resort to this remedy, stake their lives, their property, and every claim for protection given by citizenship--on the issue. Victory, or the conditions imposed by the conqueror--must be the result.
## Dawn Patrol...
No, we cannot see the sun rise this morning:
## Paul Krugman Is Depressed by How Very Little Republican Politicians Know
It really does seem that to actually know something about the world leads you to say things that disqualify you from a position of authority in the Republican Party.
Paul Krugman:
Shiny Lazy People: A few further thoughts about the Ryan response to the SOTU... [I]f your whole public act is based on your supposed knowledge of the importance of fiscal responsibility, wouldn’t you long ago have made sure that you actually know something about the fiscal crises now taking place in Europe? But no. I suspect that Ryan is honestly unaware that Ireland, far from being a spendthrift, was seen as a fiscal role model before the crisis. And that’s not hyperbole: in 2006 George Osborne, now Britain’s Chancellor of the Exchequer, declared that
Ireland stands as a shining example of the art of the possible in long-term economic policymaking, and that is why I am in Dublin: to listen and to learn.
And I also suspect that Ryan is honestly unaware that the UK has not, in fact, experienced a debt crisis.
How can he be unaware of these things? The only explanation I have is intellectual laziness — why check the facts when you already believe that you have The Truth?...
Ryan warns that if we don’t deal with our fiscal problems, we’ll have to raise taxes and cut benefits for seniors. So what can we do to reduce the deficit? Well, government spending is dominated by the big 5: Social Security, Medicare, Medicaid, defense, and interest payments; you can’t make a significant dent in the deficit without either raising taxes or cutting those big 5. Defense is untouchable, says the GOP; so that leaves the entitlement programs. And 2.7 of the three entitlement programs are benefits to seniors (70 percent of Medicaid spending goes on seniors). So let’s see: to avoid cuts in benefits to seniors, we must … cut benefits to seniors.
I’m reasonably sure that Ryan hasn’t thought any of this through.
## Macro Advisers Becomes Increasingly Confident
They think we will have a real recovery:
The unanticipated strength in new home sales in December raised our forecast for growth of brokers' commission in the first quarter. To the nearest tenth, this left our tracking estimate of GDP growth in the first quarter unchanged at 4.0%...
## Reality-Based Economists' Letter on the Affordable Care Act
David Cutler, Harold Pollack, and Karen Davenport put this letter http://www.americanprogressaction.org/issues/2011/01/pdf/budgetcommitteefinal.pdf together and assembled the signatures in 48 hours...
Harold Pollack emails:
We have at last count 272 labor, public finance, and health economists, several on this list. Had we included health services researchers and other social scientists (a tiny number of non-economists ended up on there for various random reasons), we could have doubled that number with people who have credible specific expertise. A pdf should be posted soon.
What's striking is the reach across the profession--not so much the dignitaries such as Arrow or Kahneman, but former CBO, Treasury, CEA people, serious people in research and government.... For what it's worth in a post-truth environment, we can honestly say that economic and clinical claims made on behalf of the repeal effort are generally viewed as non-substantive within the health policy community, and that ACA commands broad support from researchers who have researched the subject.
January 26, 2011
Honorable Dave Camp, Chairman
Honorable Sander Levin, Ranking Member
U.S. House of Representatives
Committee on Ways and Means
Washington, DC 20515
Dear Chairman Camp and Representative Levin:
This week, Congress is holding hearings on the economic impact of health care reform. We write to convey our strong conclusion that leaving in place the Patient Protection and Affordable Care Act of 2010 (ACA) will significantly strengthen the economy and promote economic recovery. Repealing the Affordable Care Act would cause needless economic harm, and would set back efforts to create a more disciplined and more effective health care system.
Our conclusion is based on two economic principles. First, high medical spending harms employment and economic growth. Many studies demonstrate that employers respond to rising health insurance costs by reducing wages, hiring fewer workers, or some combination of the two. Lack of universal coverage impairs job mobility as well; workers pass up opportunities for self-employment or for positions working for small firms because they fear losing their health insurance or facing higher premiums. Second, the ACA contains essentially every cost-containment provision policy analysts have considered effective in reducing the rate of medical spending. These provisions include:
• Payment innovations including greater reimbursement for patient-centered primary care; bundled payments for hospital, physician, and other services provided for a single episode of care; shared savings approaches or capitation payments that reward accountable provider groups that assume responsibility for the continuum of a patient’s care; and pay-for-performance incentives for Medicare providers.
• An Independent Payment Advisory Board with authority to make recommendations to reduce cost growth and improve quality within both Medicare and the health system as a whole
• A new Innovation Center within the Centers for Medicare and Medicaid Services, or CMS, charged with streamlining the testing of demonstration and pilot projects in Medicare and rapidly expanding successful models across the program
• Measures to inform patients and payers about the quality of medical care providers, which provide relatively low-quality, high-cost providers financial incentives to improve their care
• Increased funding for comparative effectiveness research
• Increased emphasis on wellness and prevention
Taken together, these provisions are likely to reduce employer spending on health insurance. Estimates suggest spending reductions ranging from tens of billions of dollars to hundreds of billions of dollars. Because repealing reform would eliminate the above provisions, it would increase business spending on health insurance, and hence reduce employment. One study concludes that repealing ACA would produce job reductions of 250,000 to 400,000 annually over the next decade. Worker mobility would be impaired as well, as people remain locked into less productive jobs just to get health insurance.
## Why Obama's Poll Ratings Are Rising
Our politics has been badly broken by the Republican Party. I think that Greg Sargent nails it:
Why Americans think Obama is too liberal: What McConnell was really saying here is that if any Republicans signed on to Obama's proposals, it risked suggesting to the American people that Obama's governing approach was moderate or even somewhat centrist -- something that could command some agreement. By contrast, when no Republicans signed on to Obama's proposals it made it far easier for them to paint Obama's agenda as ideologically off the rails to the left, which is exactly what they did.
If no Republicans were willing to sign on to Obama's proposals, that had to indicate that something was seriously amiss and that there was cause for real alarm about the overreaching nature of his agenda, right? And judging by the outcome of the midterms, this strategy worked....
[I]t's no accident that in the wake of Obama's successful passage of legislation with bipartisan support -- the tax deal, the New START treaty, the repeal of don't ask don't tell -- the new NBC/WSJ poll finds that the number who think Obama is "moderate" has suddenly jumped to the highest ever of his presidency. As McConnell recognized, denying Obama bipartisan support during his first two years made it far easier to paint him as an out-of-control old-style big government liberal....
What McConnell shrewdly recognized is that the public would read the absence of bipartisan cooperation with Obama as a sign of liberal extremism, and would perceive any bipartisan support for his agenda as a sign of moderation, regardless of the policy details. This is exactly what happened....
[Obama's] fundamental approach -- combine center-left and Republican solutions -- has been more or less the same throughout. He offered deals on health reform, just like on taxes. But they were rejected. The main difference is that Republicans signed on to the post-election initiatives, making them look "moderate" in comparison to the previous ones.
## Hoisted from Comments: Are You Still Rich If You Spend Your Money Living in a Nice Place?
Bloix:
Are You Still Rich If You Spend Your Money Living in a Nice Place?: Re: "A family with two $75k earners is middle-class in the Bay Area, but is living high on the hog in Austin, Texas." A family with two earners who can make$75k each in the Bay Area can't possibly make $75k each in Austin, Texas. "more people would rather live in San Francisco than in Austin: that is why living in San Francisco is so expensive." I strongly suspect that if you went down to the Embarcadero and made an announcement to all the legal assistants and IT personnel and secretaries and office managers and all the other support positions for the law firms and banks and brokers, "You can all move to Austin and get an equivalent job at your current salary," the support infrastructure of those office buildings would empty out in half an hour. The reason the people who make$75k are in the Bay Area is that the people who make ten times that want to be in the Bay Area, and the $75k-ers need to be where the$750k-ers want to be.
Well, if they want to be $75Kers, they do. And why do the$750Kers want to be in San Francisco? They clearly think the tradeoff is worth it, and the stuff rich people usually buy--very large homes with large grounds--is the stuff for which the price gradient is the steepest of all.
## What More Is There to Be Said?
The kicker is that Jean-Baptiste Say did not believe in "Say's Law" as a short-run phenomenon. Even in 1803 he acknowledged the possibility of an excess demand for money--although he did dismiss it as a very transitory something that would be easily remedied:
Jean-Baptiste Say (1803), A Treatise on Political Economy Book I, Chapter XV: Sales cannot be said to be dull because money is scarce, but because other products are so. There is always money enough to conduct the circulation and mutual interchange of other values, when those values really exist. Should the increase of traffic require more money to facilitate it, the want is easily supplied, and is a strong indication of prosperity—a proof that a great abundance of values has been created, which it is wished to exchange for other values. In such cases, merchants know well enough how to find substitutes for the product serving as the medium of exchange or money...
By 1829, however, Say's analysis of an excess demand for money in a financial panic and its consequences for production and employment is--well, it sounds Keynesian:
Jean-Baptiste Say (1829), Cours Complet d'Economie Politique Pratique: The Bank [of England]... to limit its losses... forced the return of its banknotes and ceased to put new notes into circulation. It was then obliged to cease to discount commercial bills. Provincial banks were in consequence obliged to follow the same course, and commerce found itself deprived at a stroke of the advances on which it had counted, be it to create new businesses, or to give a lease of life to the old.
As the bills that businessmen had discounted came to maturity, they were obliged to meet them, and finding no more advances from the bankers, each was forced to use up all the resources at his disposal. They sold goods for half what they had cost. Business assets could not be sold at any price. As every type of merchandise had sunk below its costs of production, a multitude of workers were without work. Many bankruptcies were declared among merchants and among bankers, who having placed more bills in circulation than their personal wealth could cover, could no longer find guarantees to cover their issues beyond the undertakings of individuals, many of whom had themselves become bankrupt...
It has, after all, been known since at least 1829 that planned expenditure can fall short of planned production if people in aggregate plan to hold more liquid cash money, more savings vehicles, or more safe assets than financial markets have to supply--and that the consequence of planned spending falling short of planned production is depression and unemployment.
If Jean-Baptiste Say himself expressly argued that a financial crisis can produce a shortage o demand and a depression, what more is there to be said?
Paul Krugman:
The War on Demand: Something really strange has happened to the debate over economic policy in the face of the Great Recession and its aftermath — or maybe the real point is that events have revealed the true nature of the debate, stripping away some of the illusions. It’s a bigger story than any one point of dispute — say, over the size of the multiplier, or the effects of quantitative easing — might suggest. Basically, in the face of what I would have said is obviously a massive shortfall of aggregate demand, we’re seeing on all-out attack on the very notion that the demand side matters.
This isn’t entirely new, of course. Real business cycle theory has been a powerful force within academic economics for three decades. But... RBC guys had very little impact on public or policy discussion....
Now, however... it’s becoming clear that many people don’t so much disagree with the idea that demand matters as find it abhorrent, incomprehensible, or both. I fairly often get comments to the effect that I can’t possibly believe what I’m saying about monetary or fiscal policy, that no sensible person could believe that printing money or engaging in deficit spending will increase output and employment — never mind that all I’m saying is what Econ 101 textbooks have been saying for the last 62 years.
So what’s going on here?
First, Keynes was right: Say’s Law — the notion that income must be spent, and hence that supply creates its own demand — really is at the heart of the issue. Many, many people just can’t see how it’s possible for there to be an overall shortfall of demand. The reason I’ve always loved the baby-sitting coop story is that it’s a human-scale example of how demand shortfalls are possible. But my experience is that if you try telling that story to someone convinced that demand can’t ever be a problem, it just bounces off: the minute you finish, they’re back to saying that income must be spent on something, so a shortage of demand can never happen, and any rise in one person’s spending must lead to an equal fall in someone else’s spending.
Second... many people find the notion of inadequate demand abhorrent... [from] notions of morality.... [A] substantial number of writers on economics find the whole idea that the economy can suffer because people are too thrifty, insufficiently willing to spend, deeply repugnant.... The world shouldn’t be like that — and therefore it isn’t.
Third, monetarists — old-style Friedman-type monetarists who focus on monetary aggregates, or the new style which says that the Fed can and should target nominal GDP — are... part of the axis of monetary evil as far as the demand-deniers are concerned.... [F]rom the point of view of those who can’t see how demand can possibly matter they’re... Keynesians....
It’s kind of shocking if you think about it. Here we have a huge, hard-won intellectual achievement, one that accounts very well for the world we actually see, and yet it’s being thrown away because it doesn’t go along with ideological preconceptions. Once that sort of thing starts, where does it stop? The next thing you know, the theory of evolution will get the same treatment. Oh, wait.
Seriously, though, this is truly sad — and dangerous. Demand-side understanding, in my view, played a big role in helping us avoid a full replay of the Great Depression; if enough people had shared that understanding, we might have avoided even the minor-league Depression we’re going through. But willful ignorance is on the march — and the odds are that we’ll handle the next crisis very badly.
## Liveblogging World War II: January 24, 1941
Harold Hinton:
LINDBERGH URGES NEGOTIATED PEACE: URGES NEUTRALITY; Aviator Testifies He Wants Neither Side to Win Conflict 'MISTAKE' TO AID BRITAIN This Prolongs War, He Says: Any negotiated peace to end the European war as soon as possible, whether or not such a peace would be considered just by the American people, would be preferable, in the interest of the United States, to prolonging the present conflict, Colonel Charles A. Lindbergh told the House Foreign Affairs Committee at its public hearing today.
## Why Oh Why Can't We Have a Better Press Corps?
Has anybody ever seen a more diabetic coma-inducing beat sweetener than this, from Peter Baker of the New York Times?
Peter Baker:
The selection of [Gene] Sperling, who held the same job under Clinton [as Larry Summers's replacement], was telling. A onetime boy wonder who, despite his graying hair, still has the same whirling-dervish, work-till-midnight energy, Sperling... passed over for other prominent jobs... bided his time as a counselor to Geithner, and eventually won over Obama with his doggedness. As a champion of the payroll tax holiday, he proved critical to shaping Obama’s tax deal with Republicans and so many other issues that White House officials refer to him as B.O.G., the Bureau of Gene. Where Summers was a master macroeconomic thinker, Sperling is known for his mastery of getting things done, or at least waging the fight, in the place where policy, politics and media meet...
If anyone knows of any more fulsome, cloying, and extravagant praise by a reporter of a hoped-for future source, I'd love to see it in the comments...
## Hoisted from Comments: More Thoughts on the Repeal-and-Replace the Affordable Care Act Crowd...
James Wimberly
The Remarkable Spectacle of the Repeal-and-Replace the Affordable Care Act Crowd...: Look at the amicus brief of a far more reputable gaggle of economists in the Florida individual mandate case:
It really is no contest on the quality of argumentation.
BTW, the case for ACA as near to the best feasible reform was abundantly made at the time. Standing laws don't need continuous fresh defences. It's up to the repeal-and-a-pony crowd to make their case, and there isn't one.
Indeed:
## Invisible Campaign
Josh Marshall:
Invisible Campaign: I saw the news on Friday that former House Speaker Newt Gingrich will base his presidential campaign in Georgia. Isn't this like my telling you that my imaginary friend is quitting the venture capital business and becoming a folk singer? Interesting news but somehow the premise is more telling than the news itself.
Can Gingrich still raise any money?
## Holy Fracking Climate Frack!!
Now that's a positive temperature anomaly!
Bob Henson:
Cold comfort: Canada's record-smashing mildness: Some fascinating weather has unfolded across the Northern Hemisphere over the last month... heavy snow that battered the mid-Atlantic and New England states in late December... the United Kingdom’s coldest December in at least the last century. Meanwhile, the sparsely populated Canadian Arctic basked in near-unprecedented mildness.
It’s the second chapter of a tale that began a year ago, when Canada as a whole saw the warmest and driest winter in its history. Much of the blame went to El Niño, which typically produces warmer-than-average weather across Canada. So far, so good—but similar things are happening this winter, even with a La Niña now at the helm.
Just how mild has it been? The map at right shows departures from average surface temperatures for the period from 17 December 2010 to 15 January 2011, as calculated by NOAA’s Earth Systems Research Laboratory. The blue blip along the southeast U.S. coast indicates readings between 3°C and 6°C (5.4–10.8°F) below average for the 30-day period as a whole. That’s noteworthy—and in fact, it was the coldest December in more than a century of record-keeping across south Florida.... Blue also shows up across the UK, where December averaged 5.2°C (9.4°F) below normal.
What really jumps out, though, is a blob of green, yellow, orange, and red covering a major swath of northern and eastern Canada. The largest anomalies here exceed 21°C (37.8°F) above average, which are very large values to be sustained for an entire month.
To put this picture into even sharper focus, let’s take a look at Coral Harbour, located at the northwest corner of Hudson Bay in the province of Nunavut. On a typical mid-January day, the town drops to a low of –34°C (–29.2°F) and reaches a high of just -26°C (–14.8°F). Compare that to what Coral Harbour actually experienced in the first twelve days of January 2011.... After New Year’s Day, the town went 11 days without getting down to its average daily high. On the 6th of the month, the low temperature was –3.7°C (25.3°F). That’s a remarkable 30°C (54°F) above average. On both the 5th and 6th, Coral Harbor inched above the freezing mark. Before this year, temperatures above 0°C (32°F) had never been recorded in the entire three months of January, February, and March....
In mid-December, a vast bubble of high pressure formed in the vicinity of Greenland. At the center of this high, the 500-mb surface rose to more than 5.8 kilometers, a sign of remarkably mild air below. Stu Ostro (The Weather Channel) found that this was the most extreme 500-mb anomaly anywhere on the planet in weather analyses dating back to 1948.... Farther west, a separate monster high developed over Alaska last week....
Why so freakishly mild? One factor that both feeds and is fed by the warmth is the highly unusual amount of open water across seas that are normally frozen by late November. On the winter solstice (December 21), Hudson Bay was little more than half frozen... the Baffin/Newfoundland Sea fell weeks behind schedule in freezing up. As evident in the charts at bottom, these bodies of water remain in catch-up mode....
The extraordinary Arctic warmth and the midlatitude chill and snow bear the fingerprints of a negative North Atlantic Oscillation (NAO), the pattern that prevailed for much of last winter as well. As opposed to a positive NAO, where the jet stream whisks mild air across the Atlantic, a negative NAO—which has predominated since October—features a blocked-up jet stream that allows cold air to plunge more easily southward and mild air to take hold in the Arctic. It seems plausible that the open water between Greenland and Canada has played a role in the record warmth observed at the surface and aloft and the associated negative NAO. However, the NAO’s causes remain mysterious, and its future is impossible to predict...
## Brian Beutler on the Intellectual and Moral Collapse of the Republican Party...
We are unlikely to ever get a health-care system with rational financing until everybody's care is paid for by some mechanism--rather than being paid for under the heading of somebody else's insurance via cost shifting. We are unlikely to have a society we can be proud of until everyone can get easy access to preventive, acute, and chronic medical care. For both intellectual and moral reasons a health care system that does not provide universal coverage is likely to be a lousy one.
The Republican Party agreed with this up until mid 2009. Now it doesn't.
Brian Beutler watches the train wreck:
How The Health Care Repeal Push Marks The End Of The Universal Health Care Consensus: Here's one case for the individual mandate in the health care law boiled down to two sentences -- both fairly elegant considering they were spoken extemporaneously.
There isn't anything wrong with it, except some people look at it as an infringement upon individual freedom. But when it comes to states requiring it for automobile insurance, the principle then ought to lie the same way for health insurance, because everybody has some health insurance costs, and if you aren't insured, there's no free lunch. Somebody else is paying for it." -- June 14, 2009....
[T]he individual mandate actually marries two distinctly American priorities -- an obsession with private markets, and the core belief that nobody should go without health care.
Considering just how cacophonous the health care debate has become, it might surprise you to learn that the mystery reformer quoted above is Sen. Chuck Grassley (R-IA), the Republicans' health care point man in the Senate who, during the same interview, with great authority, claimed "I believe that there is a bipartisan consensus to have individual mandates."
Two months later he threw in his lot with Sarah Palin (R-AK) and the Death Panelers. Now he claims -- along with about half the attorneys general in the country -- that the individual mandate is unconstitutional and, like the rest of the GOP, uses it as the foundation for a far-reaching political assault on the health care law....
Grassley's violent lurch to the right wasn't idiosyncratic. It was the consequence of a deliberate Republican political strategy.... What was once a popular, if not consensus, policy framework on the right -- authored by personal-responsibility conservatives and popularized by John Chafee, Bob Dole, and Mitt Romney -- rapidly became kryptonite for Republican politicians. As a result, for the first time in more than a half century, there is one political party in the country that has zero high-profile advocates for a forgotten goal: that somehow, some way, every citizen deserves proper health care.
And yet they can't quite bring themselves to say that....
Now that Republicans control the House of Representatives, their fusillade against the health care law has actual legislative ammunition. But the question of what they'd replace it with is still open. "We'll let the committees do their work on how we should replace this, and what the common sense reforms will be. They'll have hearings. It'll be a bipartisan process," said House Speaker John Boehner (R-OH). We'll see what they come back with."
What they came up with last time around -- their alternative to the Affordable Care Act -- was a grab bag of industry-friendly and anti-federalist ideas: malpractice reform, allowing people to buy insurance across state lines. The outcome, according to congressional actuaries, would be roughly no decrease in the number of uninsured people, when you adjust for population growth. "By 2019, CBO and JCT estimate, the number of nonelderly people without health insurance would be reduced by about 3 million relative to current law, leaving about 52 million nonelderly residents uninsured. The share of legal nonelderly residents with insurance coverage in 2019 would be about 83 percent, roughly in line with the current share"...
## Mark Thoma Has a Forecst of Obama's State of the Union Address
Mark Thoma:
Economist's View: SOTU: Obama's Focus on Jobs: This is a year too late, more than that actually, but President Obama's intent to focus on jobs in the State of the Union address is welcome. The abandonment of the recommendations of the bipartisan majority on the debt-reduction commission -- for now anyway -- is also good news. This committee appeared to have Social Security in its sights mostly for ideological reasons rather than as something that would make a meaningful dent in the budget problem...
What puzzles me is what a "focus on jobs" means. At one level, it means neoliberal Democratic business as usual: most of our policies are, after all, aimed at raising the productivity of and the demand for labor. But "focus on jobs" implies policies that the executive branch can do on its own or persuade congress to pass that will have a large bang, and it is not clear to me what the White House thinks those are.
## Matthew Yglesias Watches Douglas Holtz-Eakin Continue to Set His Own Credibility on Fire
Matthew Yglesias:
Yglesias » Is Repealing the Affordable Care Act Secretly About Replacing It With a Different Secret Law?: In a word: No. But don’t tell wonk-turned-hack Douglas Holtz-Eakin who explains:
Replacing PPACA with real health-care reform that delivers quality care at lower costs. That is what the repeal vote is really about.
I always forget if I’m allowed to use the word “bullshit” on an official CAPAF website (that was a mention—thanks Professor Goldfarb!), but I think this is best analogized to the solid waste of a male bovine. This just isn’t how public policy works. We change (or “replace”) laws all the time, and it doesn’t happen by first repealing predecessor laws tout court and then gesturing vaguely at a replacement. My guess is that Holtz-Eakin has a bunch of ideas about ways to improve health care policy in the United States relative to the post-ACA status quo. My guess is that I even agree with some of those ideas. The way to get those ideas enacted is to start explaining them to the press and the public and start talking to members of congress about turning them into bills.
At this point I’m not actually sure what the repeal vote is “really” about, but it’s definitely not about starting concrete conversations about further changes to the American health care system...
I was much more impressed by the Republican economists who did not sign than by those who did.
## Liveblogging World War II: January 23, 1941
Operation Compass: General O'Conner's command captures Tobruk in Libya:
Brits and Australians take Tobruk: the British 7th Royal Tank Regiment drove westward from Bardia, which it had just taken from the Italians, with the intention of isolating Tobruk until the 6th Australian Division could aid in an assault. The attack on the coastal fortress of Tobruk was finally launched on the 21st and it fell the next day, yielding 30,000 Italian prisoners, 236 guns, and 87 tanks.
## The Remarkable Spectacle of the Repeal-and-Replace the Affordable Care Act Crowd...
Andrew Sabl:
Two hundred economists (and nothin’ on): A few days ago, Politico Pulse (can’t find a permalink, but here’s where The Weekly Standard’s blog reprinted the story) published an item saying:
House Republicans open the health reform repeal debate today with an ace up their sleeves: a letter making the economic case for repealing the law, signed by 168 tenured economics professors and academic institution-affiliated scholars, two former CBO directors and four Federal Reserve economists, including a Nobel Laureate, among others.
"We believe the Patient Protection and Affordable Care Act is a threat to U.S. businesses and will place a crushing debt burden on future generations of Americans," the 200 economists write, in a letter organized by the American Action Forum and obtained by PULSE. They charge that the law is a barrier to job growth and a "massive spending increase" adding $1 trillion in government spending over the next decade. Here's the (rather overheated) letter. Conveniently, it was followed a couple of days later by a crowd-sourced rating of top economics departments.... Of the 200 or so economists signing the letter, the number who teach at the top ten departments is four: Michael Boskin from Stanford... Robert Lucas from Chicago... and two from Columbia. We'll add the Nobel Laureate.... That makes five out of two hundred from top ten departments or the equivalent. On the other hand, Hillsdale College is well represented (four signers), as are conservative think tanks.... A letter like this is a political exercise, and the currency of politics is reputation. Whoever circulated the letter knew full well that the more famous economists from prestigious departments who signed it, the more impact it would have among people who actually care what experts think. And this is the best they could do... Indeed. They also couldn't get even 200 to sign on for "repeal"--all they would sign on to is "repeal-and-replace." And they couldn't get 200 to sign on to any specific replacement: just a vague fuzzy generic "replace." And they couldn't get 200 to say a single word about why they think the CBO score of the bill is wrong--I mean, if it levies big taxes it is likely to reduce the deficit, right? The argument that it (a) levies big taxes and (b) increases the deficit is rather incoherent. And they couldn't get more than two former Republican CEA members to sign on either... ## Are You Still Rich If You Spend Your Money Living in a Nice Place? Hoisted from Comments: Noah writes: No, This Is Not Surprising...: I wish they would adjust these things for cost of living (or at least housing prices). A family with two$75k earners is middle-class in the Bay Area, but is living high on the hog in Austin, Texas.
But (unless you really like JEN-U-INE Mex-Tex food, and love to go to the Salt Lick and sit outside on those July evenings when the temperature is still 110F at 9 PM) more people would rather live in San Francisco than in Austin: that is why living in San Francisco is so expensive.
Living in a nice place that is expensive because it is nice is one way to spend the money you have when you are relatively rich--it does not keep you from being relatively rich.
## Why Oh Why Can't We Have a Better Press Corps? (Peter Baker/New York Times Edition)
Robert Waldmann is annoyed at the New York Times's failure to fact-check Peter Baker and Peter Baker's inability to fact check himself.
Here's Peter Baker:
Obama’s Jobs Search: ACROSS LAFAYETTE SQUARE from the White House is the headquarters of the United States Chamber of Commerce. Last spring, four massive banners were hung on its building spelling out “J-O-B-S,” a message presumably visible from the third floor of the White House, where the president wakes up. By fall, the chamber and Obama were at war during a midterm campaign that ended with repudiation of the president’s party.
“The basic issue here,” Thomas Donohue, the chamber president, told me last month, “is uncertainty — uncertainty on what health care is actually going to cost, uncertainty on hundreds of rule-makings in the Dodd-Frank bill, uncertainty about what’s going to come out of the E.P.A. putting through what they couldn’t get legislatively, uncertainty about taxes.”
The health care program and the financial-regulation law sponsored by Senator Chris Dodd and Representative Barney Frank were bad enough, as far as the chamber was concerned. But Obama’s periodic forays into populism made it personal. He couldn’t seem to decide whether he was going to take Wall Street to task for its irresponsible behavior or cajole it into freeing up money to get the economy moving. One day he derided “fat-cat bankers” who caused the recession; another day, he soothed them by saying that he and the American people “don’t begrudge” multimillion-dollar bonuses...
Robert Waldmann:
Robert's Stochastic thoughts: [Baker's] claim "he soothed them by saying that he and the American people 'don’t begrudge' multimillion-dollar bonuses." is false.... I quote the context of the two words TWO Words ! which Baker ripped out of context.
Q Let's talk bonuses for a minute: Lloyd Blankfein, $9 million; Jamie Dimon,$17 million. Now, granted, those were in stock and less than what some had expected. But are those numbers okay?
THE PRESIDENT: Well, look, first of all, I know both those guys. They're very savvy businessmen. And I, like most of the American people, don't begrudge people success or wealth. That's part of the free market system. I do think that the compensation packages that we've seen over the last decade at least have not matched up always to performance. I think that shareholders oftentimes have not had any significant say in the pay structures for CEOs...
Obama said that the US people don't begrudge success or wealth as such, however, wealth based on Wall Street compenstation packages have no justification. Just to make it absolutely clear that Baker libeled Obama, I will also report the follow up question and answer:
Q Seventeen million dollars is a lot for Main Street to stomach.
THE PRESIDENT: Listen, 17 million is an extraordinary amount of money. Of course, there are some baseball players who are making more than that who don't get to the World Series either. So I'm shocked by that as well. I guess the main principle we want to promote is a simple principle of "say on pay," that shareholders have a chance to actually scrutinize what CEOs are getting paid. And I think that serves as a restraint and helps align performance with pay. The other thing we do think is the more that pay comes in the form of stock that requires proven performance over a certain period of time as opposed to quarterly earnings is a fairer way of measuring CEOs' success and ultimately will make the performance of American businesses better... Baker falsely asserts [this interview] shows Obama soothing Wall Street executives, [but instead] he advocated regulation of compensation... ## Thomas Jefferson Believed the Federal Government Could Regulate "Inactivity" Rick Ungar: Thomas Jefferson Also Supported Government Run Health Care: In response to my earlier piece on “An Act for the Relief of Sick and Disabled Seamen”, the 1798 law revealing that a number of our founders were more supportive of the notion of mandated health coverage and a government run hospital system than some may have imagined, many have noted that it is not surprising that such legislation would have been signed into law by President John Adams, a noted Federalist.... Greg Sargent, today reports that it wasn’t only John Adams who supported the notion of government run health care. According to Georgetown University history professor and noted historian of America’s early days, Adam Rothman, Thomas Jefferson –the iconic hero of the Tea Party – also supported the legislation. Sargent reprints the following email he received from Prof. Rothan on the subject – Alexander Hamilton supported the establishment of Marine Hospitals in a 1792 Report, and it was a Federalist congress that passed the law in 1798. But Jefferson (Hamilton’s strict constructionist nemesis) also supported federal marine hospitals, and along with his own Treasury Secretary, Albert Gallatin, took steps to improve them during his presidency. So I guess you could say it had bipartisan support. Ezra Klein adds to the debate pointing out that: ...it was a payroll tax that all sailors on private merchant ships had to pay, and in return, they were basically given access to a small public health-care system. But it was, in essence, a regulation against a form of inactivity: You were not allowed to not do something, in this case, pay for sailor’s health insurance. There are those who will continue to argue that these indications of how the founders viewed these issues in their own time do not necessarily resolve the issue as to how we may, Constitutionally speaking, proceed with reforming the health care system of today. They may well be right. But, at the least, can we not agree that the mounting evidence as to how men like Jefferson and Adams perceived the issue should bar the attempt to pin the objections to health care reform on the backs of the nation’s founders?... ## No, This Is Not Surprising... S.D. of the Economist asks a question: S.D.: The rich in America: Who's rich?: [A]nother thing that I, at least, was struck by when I looked at the Saez-Piketty data was the thresholds for being in the top 10% and 5% of the American population.... To get into the top 5%, you need to earn less than150,000. To me, it's something of a wake-up-call to realise that a couple who make $75,000 each are in the top 5% of American households. I'm curious whether this is surprising to others, too? Would you, like me, have guessed the thresholds were higher? Does this change what you think about who is "rich" in America today? It is not surprising, that is, if you keep your eyes open and criss-cross either urban or rural America. It is not surprising if you channel-surf cable TV and think about the advertisements that you watch and understand that advertisements are aimed at attracting disposable income dollars... ## Why We Don't Believe that the Fact that We Had too Many People Working in Construction in 2007 Has Much to Do with Our Current 10% Unemployment The arithmetic simply does not add up. We had a construction cycle, but a simple shift of demand from construction to other sectors and the shifting of labor out of construction and the process of retraining construction workers for other occupations does not produce the more than six million fall in payroll employment from mid-2008 to mid-2009. It simply does not. ## Why Oh Why Can't We Have a Better Press Corps? Joshua Green writes: Bad Climate for Global Warming: Last week, the National Oceanic and Atmospheric Administration and NASA's Goddard Institute for Space Studies announced that 2010 had registered as the hottest year on record. Nothing new here: nine of the last 10 years have been among the warmest ever. The news highlighted one of Washington's biggest failures over the last two years: its inability to advance climate legislation... Now let's stop right now. The inability to advance climate legislation wasn't "Washington's" failure: it was a failure of Republican legislators, their tame hacks and propagandists, the carbon-energy lobby, and coal-state Democratic legislators. Joshua Green knows who the culprits are as well as I do. But for some reason he does not believe he can say so in his lead. Why not, Joshua? Why not? Why oh why can't we have a better press corps? Here is the full piece: Bad Climate for Global Warming - Joshua Green - Politics - The Atlantic: Last week, the National Oceanic and Atmospheric Administration and NASA's Goddard Institute for Space Studies announced that 2010 had registered as the hottest year on record. Nothing new here: nine of the last 10 years have been among the warmest ever. The news highlighted one of Washington's biggest failures over the last two years: its inability to advance climate legislation. It was also a grim reminder that things could get worse. Some crucial policy areas have always been neglected and some initiatives stalled. But rarely has a first-order concern like the nation's climate and energy policy actually regressed -- and so dramatically as we've seen since the last presidential election. Not long ago, it appeared likely that the United States would take meaningful action to mitigate climate change. In the 2008 presidential campaign, both Barack Obama and John McCain touted plans to limit carbon emissions under a cap-and-trade scheme. Even Sarah Palin supported the idea. Much of the business community did, too. Adding momentum was the recent Supreme Court ruling, in Massachusetts vs. Environmental Protection Agency, that required the EPA, under the Clean Air Act, to regulate harmful greenhouse gas emissions. Lawmakers, it was presumed, would take the matter into their own hands rather than cede that authority. Of course, this didn't happen. Over the strenuous objections of Republicans and coal-state Democrats, the House of Representatives passed a cap-and trade bill in 2009 that met an ignominious death in the Senate. Along the way, cap-and-trade -- originally a conservative idea -- came to be vilified as "cap and tax'' and regarded by a substantial part of the conservative base as a form of fascist oppression. Today, fewer Americans believe in the reality of global warming than did so two years ago, and many took out their wrath last November on Democrats who'd supported a climate bill. But this doesn't capture the full scale of the setback. Since that debacle, momentum in Congress has shifted strongly against climate-change legislation. If you want to frighten one of the remaining Democrats, suggest that he or she take another shot at passing cap-and-trade. There's still the EPA. When both parties favored cap-and-trade, this option was viewed as the less desirable one. The agency could limit greenhouse gas emissions, but not through a system as flexible and efficient as cap-and-trade, which included simple improvements like building-efficiency standards that lay beyond the agency's remit. EPA regulations would thus be less effective. The cap-and-trade bill that passed the House aimed to reduce emissions 17 percent by 2020 from their 2005 levels. A World Resources Institute study found that the most aggressive implementation of EPA regulations would only reduce emissions by 12 percent in that time frame. Scientists say reductions of 36-48 percent would be necessary to halt global warming. "Having EPA set carbon-pollution reductions was everyone's second choice for slowing global warming,'' said Daniel J. Weiss, director of climate strategy at the Center for American Progress Action Fund. "It was like 'In Case of Congressional Gridlock Break Glass.' '' Now, the backup plan is the only plan, and "aggressive'' regulations are off the table. Last year, the EPA issued a "tailoring rule'' signaling how it intended to proceed. The results in no way resembled the fears expressed by many detractors that a burdensome new system of regulations would be imposed on small businesses. Instead, the EPA will confine its attentions strictly to the largest polluters, such as power plants, oil refineries, and chemical manufacturers. These modest steps won't do nearly as much to slow global warming as the other, broader plans. But because the battle has shifted from the legislative to the regulatory front, the EPA nonetheless finds itself under attack from the newly empowered Republicans. One of the first things they will do is try to block EPA from establishing pollution standards, possibly by denying funds or refusing to raise the debt ceiling unless the process is slowed or halted. It's not clear whether they'll succeed. But given the heightened importance of stronger restrictions, environmentalists can't feel good about recent developments. Earlier this week, the Obama administration said it would focus on eliminating regulations, rather than strengthening them. That's probably an accurate reading of the political climate. But for the planet's climate, it's yet another blow. ## Comments on Doug Irwin: Peddling Protectionism: Smoot-Hawley and the Great Depression. PUP: "An astute and well-told account of a law more often invoked than understood, Irwin's examination of the Smoot-Hawley Act explains how--for good or ill--Congress lost its credibility as a maker of trade law. A valuable book for anyone who wants to understand the Great Depression and whether it could come back." --Eric Rauchway, author of Blessed Among Nations and The Great Depression and the New Deal: A Very Short Introduction "Douglas Irwin's elegant and sophisticated account of the Smoot-Hawley Tariff clears up some powerful and persistent myths. As Irwin shows, the tariff didn't begin with congressional logrolling (though that contributed substantially to the eventual outcome), it didn't cause the stock market panic of October 1929, and it didn't cause the Great Depression (but neither did it counteract deflation from abroad as some Keynesians and monetarists have claimed). And many of the book's details are fascinating and even bizarrely amusing." --Harold James, Princeton University "Economists and economic historians have closely examined the Smoot-Hawley Tariff over the past few decades, but no one before Douglas Irwin has pulled together such a wide-ranging body of evidence to give us a solid and detailed understanding of the passage and impact of the bill. Understanding the Great Depression has become even more important since the global financial crisis, and that makes this book very timely. Brief, accessible, and clear, Peddling Protectionism should appeal to a wide range of readers." --Robert Whaples, Wake Forest University "It would not surprise me if this became the definitive economic history of the Smoot-Hawley Tariff. Synthesizing and fleshing out the best research and nicely connecting economics and politics, Peddling Protectionism provides a fuller accounting of, and a deeper perspective on, what is arguably the best-known U.S. tariff of the twentieth century." --Kris Mitchener, Leavey School of Business, Santa Clara University Damned if I can think of who the "Keynesians and monetarists" are who claimed that Smoot-Hawley was stimulative by "counteract[ing] deflation from abroad." I was always taught by Keynesians and monetarists that Smoot-Hawley and retaliative moves by other countries together administered a contractionary supply shock to the world economy--although not one big enough to make the Great Depression great... ## Perhaps I Should Give More Tests... Jeffrey D. Karpicke and Janell R. Blunt: Retrieval Practice Produces More Learning than Elaborative Studying with Concept Mapping: Educators rely heavily on learning activities that encourage elaborative studying, while activities that require students to practice retrieving and reconstructing knowledge are used less frequently. Here, we show that practicing retrieval produces greater gains in meaningful learning than elaborative studying with concept mapping. The advantage of retrieval practice generalized across texts identical to those commonly found in science education. The advantage of retrieval practice was observed with test questions that assessed comprehension and required students to make inferences. The advantage of retrieval practice occurred even when the criterial test involved creating concept maps. Our findings support the theory that retrieval practice enhances learning by retrieval-specific mechanisms rather than by elaborative study processes. Retrieval practice is an effective tool to promote conceptual learning about science. ## Why Oh Why Can't We Have a Better Press Corps? In my email inbox this morning, apropos of the New Yorker: All the little details are off. Cloudberry gelato isn't a thing. (Cloudberry sorbet maybe). The stuff about yuppie women doing workouts that emphasize the upper body... surely he could have read the wikipedia entries for pilates or spinning. Sometimes I wonder if [David Brooks] knows any actual people, or just bases his writing on cliches he picks up on the internet... So I went and checked: David Brooks: What the science of human nature can teach us: High-status women, on the other hand, pay ferocious attention to their torsos, biceps, and forearms so they can wear sleeveless dresses all summer and crush rocks with their bare hands.... Occasionally, you meet a young, rising member of this class at the gelato store, as he hovers indecisively over the cloudberry and ginger-pomegranate selections, and you notice that his superhuman equilibrium is marred by an anxiety... Indeed yes: "cloudberry gelato" produces only six hits on google. "cloudberry sorbet" produces about "about 1,000". ## Liveblogging World War II: January 22, 1941 From On War: Wednesday, January 22, 1941: In North Africa... The remainder of the garrison of Tobruk surrenders after demolishing some of the harbor facilities. There are 27,000 prisoners. Much equipment is also captured and in fact it will prove possible to put the port into service fairly quickly. The Allied casualties have been less than 500 men. ## McSweeney's Internet Tendency: TED Talks Throughout History. John Cafiero: Have We Been Worshiping the Wrong Sacred Tree? The Wheel Will Change the Way We Live Forever, Once We Turn It on Its Side and Attach It to Something, But What? Global Initiatives for Making God Less Angry How "Coins" Are Revolutionizing Bartering Dragon Lairs, Leprechaun Hoards, and Other Promising Sources of Wealth in the New Economy We Already Have the Technology to Turn Lead into Gold. Why Aren't We Doing It? Not Your Father's Execution: How the Guillotine is Changing the Way We Think about Beheading Reinventing the Factory: How the Use of Children In Manufacturing Benefits Us All Are Peasants People? ## Why Republicans Should Be Embarrassed to Advocate Repealing the ACA Aaron Carroll: More mandate-relevant evidence | The Incidental Economist: Yesterday I described a new paper that provided evidence that the individual mandate in Massachusetts has done the job it was designed to do, namely to cause the individual insurance market risk pool to become more favorable (include more relatively healthy individuals than it otherwise would). >Today there is more evidence that a means of motivating healthy individuals to enroll (like a mandate) is a necessary part of insurance market reforms. Anthony Lo Sasso shows that community rating and guaranteed issue in the absence of a mandate (or some other incentive for the healthy to enroll) cause the risk pool to become more adverse (include more relatively sick individuals).... Lo Sasso explains: T[C]ommunity rating was associated with a worsening of the non-group risk pool as younger and healthier individuals left the individual market while older and sicker individuals joined or remained in themarket. To test the robustness of this conclusion, we used data from the National Health Interview Survey (NHIS) to compare changes in detailed measures of health status and utilization for people with non-group coverage in several community rating and non-community rating states. We found that those maintaining non-group coverage after the adoption of community rating were significantly more likely to have days when they were restricted to bed or when their activities were otherwise restricted because of health problems as well as more doctor visits and hospital stays. In other words, community rating in the non-group insurance market led to a pool of enrollees in poorer health. [...] Our results provide a compelling portrait of the distortions that can result from community rating and guaranteed issue regulations in the non-group market when there are no provisions in place to keep people enrolled in coverage. The deterioration of the risk pool is consistent with predictions from economic theory and potentially lays the foundation for an adverse selection death spiral... Aaron Carroll again: Let’s be clear about what all this means. There are sound theoretical reasons and substantial empirical support for the idea that guaranteed issue and community rating without a mandate (or similar inducement) cause problematic levels of adverse selection. Adverse selection leads to higher premiums and can destabilize the insurance market. These are as close to facts as one gets in social science. Consequently, if one is in favor of a well-functioning insurance market in which everyone can obtain affordable insurance, one cannot advocate guaranteed issue and community rating and nothing else. One needs some way to keep adverse selection under control. To be blunt, one can’t just take the favorable parts of the ACA and reject the unfavorable part (the mandate), at least not with suggesting a replacement that will do the same job... ## Steven Hyder Thinks He Has a Constitutional Right to Be a Freeloader (No Libertarians in the Emergency Room Watch) Jonathan Cohn goes to interview him: Repealing Health Care Reform: How It Could Happen And What It Would Mean: Steven Hyder, 40, runs his own legal practice out of a shared office in downtown Monroe, Michigan, a blue-collar town south of Detroit. Mostly he handles relatively routine, low-profile work: bankruptcies, personal injury claims, that sort of thing. But recently, he became part of a much bigger case. He’s a named plaintiff in a lawsuit challenging the constitutionality of the Patient Protection and Affordable Care Act. The focus of Hyder’s suit, which was organized and written by a conservative legal organization, is the “individual mandate”—the requirement that everybody obtain health insurance or pay a fee to the government. The case is one of several moving through the federal judiciary. Sometime in the next few years, at least one of them is likely to end up before the Supreme Court. A few weeks ago, I spoke with Hyder at his office, in order to learn more about why he had brought this case. He said his motive was straightforward. He’s opted not to carry health insurance because he doesn’t think the benefits justify the price, and he doesn’t want the government forcing him to do otherwise. Okay, I asked, but what if he gets sick and needs hospitalization? How will he afford those bills? It was a distinct possibility, he agreed, patting his waist and noting that he was a little overweight. But those potential bills would be problems for him and his hospital, he suggested, not society as a whole. When I told him that I disagreed—that his decision to forgo health insurance meant other people would be paying his bills, via higher taxes and insurance premiums—he politely and respectfully took issue with my analysis. The discussion went back and forth for a while, but soon it became apparent that our differences went beyond the finer points of health care policy, to our most basic understanding of the rights and obligations of citizenship. “It’s a complete intrusion into my business and into my private life,” he told me. “I think it’s one big step towards a socialist society and I’m purely capitalist. I believe in supply-side economics and freedom”... Note that Hyder doesn't say that if he can't pay his hospital bills cash he should die in the gutter in front of the hospital. ## Donald Marron Says Greg Mankiw Gets It Wrong Donald Marron is correct. Donald Marron: What is Health Care Reform?: The policy community and commentariat often equate health care reform with the legislation (actually two pieces of legislation) that President Obama signed into law last year. As everyone knows, the Congressional Budget Office estimated that those two laws would, if fully implemented, reduce the federal budget deficit by$143 billion from 2010-2019. That’s the basis for the claim that “health care reform would reduce the deficit over the next ten years.” (CBO also discussed what would happen in later years, where the law, if allowed to execute fully, would have a bigger effect, but let’s leave that to the side right now.) The complication... is that the health care reform legislation included many provisions. Greg [Mankiw] notes, for example, that some expanded health insurance, while others raised taxes. In his view, only the first part constitutes health care reform....
In fact, it’s more complicated than that. By my count, the two pieces of health care reform legislation combined seven different sets of provisions:
1. Expanding health insurance coverage (e.g., by creating exchanges and subsidies and expanding Medicaid)
2. Expanding federal payments for and provision of health care services (e.g., reducing the “doughnut hole” in the Medicare drug benefit)
3. Cuts to federal payments for and provision of health care services (e.g., cuts to Medicare Advantage and some Medicare payment rates)
4. Tax increases related to insurance coverage (e.g., the excise tax on “Cadillac” health plans)
5. Tax increases not related to insurance coverage (e.g., the new tax on investment income)
6. The CLASS Act, which created an insurance program for long-term care
7. Reform of federal subsidies for student loans....
Greg’s point, I think, is that... [t]o say “the health care reform law reduces the deficit over the next ten years according to CBO” is absolutely true. But it often gets elided to “health care reform reduces the deficit over the next ten years” which isn’t true if, like Greg, you think the revenue raisers, student loan changes, and CLASS Act aren’t really health care reform.....
Greg’s analogy has a flaw: it presumes that none of the tax increases count as health reform. I disagree. Our current tax system provides enormous (\$200 billion per year) subsidies for employer-provided health insurance. They should be viewed as part of the government’s existing intervention in the health marketplace. And rolling back those subsidies strikes me as essential to future health care reform.... [The] tax on “Cadillac” health plans... will clearly affect health insurance markets, and it offset a portion of existing tax subsidies... [is] as part of health care reform.
The key thing is not the difference between spending and revenues, but between provisions that fundamentally change the health care system and those that do not...
By my count, more than half of the tax increases in the Affordable Care Act over the next two decades are provisions that fundamentally affect the health care system--and the share of tax increases that are clearly health related grows over time,
## Congressional Representative Jeb Hensarling (R-TX) Calls for the Repeal of the Affordable Care Act and Its Replacement by Medicare-for-All
Very good to see a Republican joining the single-payer caucus:
Henserling: The American people don’t want [the Affordable Care Act]. It’s personal. Here’s my story, two days ago, I was in San Antonio, Texas, and my mother had a large tumor removed from her head. They wheeled her away at 7:20 in the morning, and by noon, I was talking to her along with the rest of our family. It proved benign, thanks to a lot of prayers and good doctors at the Methodist hospital in San Antonio. My mother’s fine. I’m not sure that would be the outcome in Canada, the U.K., or anywhere in Europe. No disrespect to our President, but when it comes to the health of my mother, I don’t want this President or any President or his bureaucrat or commissions making decisions for my loved ones. Let’s repeal [the Affordable Care Act] today, replace it tomorrow.
Hensarling is 53 years old, so his mother is, of course, eligible for Medicare. And it’s true that Medicare, for all its flaws, is an excellent system of coverage. It’s also a system of universal taxpayer-financed government-provided health insurance... [like] Canada’s system of universal health care, which is probably why the Canadian program is also called “Medicare.” The biggest difference is that in Canada you get Medicare whether you’re 8, 18, 38, 68, or 88 whereas in the United States Medicare is only available to senior citizens. But seniors like Medicare! And so do their kids!
## High and Rising Unequality Does Not Mean that Unemployment Is "Structural"
David Leonhardt has a good response, pointing to the increasing college-high school wage premium as evidence that I am wrong and that the unemployment generated by the current downturn is structural:
Debating the Causes of Joblessness: The data that the Bureau of Labor Statistics released on Thursday gives me a chance to explain why I disagree [with Brad]. In short, the relative performance of more educated and less educated workers over the last few years has not been the typical pattern for a recession. Less educated workers, by many measures, are faring worse than they ever have.
The ratio of the typical four-year college graduate’s pay to a typical high-school graduate’s pay hit a record in 2010 — 1.56. Since 2007, the inflation-adjusted median weekly pay of college graduates has risen 1.6 percent. The inflation-adjusted pay of every other educational group — high school dropouts, high school graduates and people who attended college but did not get a four-year degree — has fallen since 2007. The same is true over the last decade; amazingly, only college graduates have received a raise.
It’s pretty surprising that college graduates’ real pay has risen during a three-year period when the economy was in miserable shape. It seems like a clear indication that our economy has an undersupply of skilled, educated workers. To put it another way, if there were more of these workers than they are, more of them would have jobs today...
I think that less-educated workers are faring worse in relative terms than they have since the end of the Gilded Age. I think that the economy is definitely short of well-educated workers--that that is why the college-high school wage premium is so high and continues to rise.
But I also think that these are issues that are almost completely separate from those of whether current unemployment is "structural"--by which I mean that an increase in aggregate demand would not produce higher employment but rather higher inflation.
After all, a rising college-high school wage premium was perfectly consistent with sub-five percent unemployment in 1999. Why should it require anything close to ten percent unemployment today? | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.16693824529647827, "perplexity": 3797.471210009213}, "config": {"markdown_headings": true, "markdown_code": false, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-30/segments/1563195530385.82/warc/CC-MAIN-20190724041048-20190724063048-00457.warc.gz"} |
http://www.msri.org/seminars/23705 | # Mathematical Sciences Research Institute
Home » Special Seminar: Simultaneous Binary Collisions and the Mysterious 8/3
# Seminar
Special Seminar: Simultaneous Binary Collisions and the Mysterious 8/3 September 13, 2018 (02:00 PM PDT - 03:00 PM PDT)
Parent Program: Hamiltonian systems, from topology to applications through analysis MSRI: Baker Board Room
Speaker(s) Nathan Duignan (University of Sydney)
Description No Description
Video
Abstract/Media
Of central importance in the N-body problem is the fact that isolated binary collisions can be regularized : that a singular change of space and time variables (first written down by Levi-Civita) allows trajectories to pass analytically through binary collisions unscathed. The resulting flow is smooth with respect to initial conditions. Curiously, we are not so lucky with simultaneous binary collisions. In a landmark paper, Martinez and Simo gave strong evidence that the best one can hope is 8/3 differentiability of the flow in a neighborhood of simultaneous binary collisions in the 4 body problem. In this talk we follow Easton by linking regularizability to the behaviour of the flow in Conley isolating blocks around the collisions. We show the 8/3 is produced from the first resonant monomial with nonzero coefficient near a degenerate singularity formed when the two binaries are separately Levi-Civita regularized. To show this, we blow-up the singularity and study the flow near the resulting two, 3:1 resonant, normally hyperbolic manifolds connected by heteroclinics. A lengthy normal form computation confirms the conjecture. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9786379933357239, "perplexity": 2228.7440992603256}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 5, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-04/segments/1547583660070.15/warc/CC-MAIN-20190118110804-20190118132804-00450.warc.gz"} |
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# Every day a certain bank calculates its average daily
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Every day a certain bank calculates its average daily [#permalink] 18 Jul 2010, 09:32
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Every day a certain bank calculates its average daily deposit for that calendar month up to and including that day. If on a randomly chosen day in June the sum of all deposits up to and including that day is a prime integer greater than 100, what is the probability that the average daily deposit up to and including that day contains fewer than 5 decimal places?
(A) 1/10
(B) 2/15
(C) 4/15
(D) 3/10
(E) 11/30
[Reveal] Spoiler: OA
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Re: MGMAT Challenge: Decimals on Deposit [#permalink] 18 Jul 2010, 10:42
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bmillan01 wrote:
Every day a certain bank calculates its average daily deposit for that calendar month up to and including that day. If on a randomly chosen day in June the sum of all deposits up to and including that day is a prime integer greater than 100, what is the probability that the average daily deposit up to and including that day contains fewer than 5 decimal places?
(A) 1/10
(B) 2/15
(C) 4/15
(D) 3/10
(E) 11/30
Theory:
Reduced fraction $$\frac{a}{b}$$ (meaning that fraction is already reduced to its lowest term) can be expressed as terminating decimal if and only $$b$$ (denominator) is of the form $$2^n5^m$$, where $$m$$ and $$n$$ are non-negative integers. For example: $$\frac{7}{250}$$ is a terminating decimal $$0.028$$, as $$250$$ (denominator) equals to $$2*5^3$$. Fraction $$\frac{3}{30}$$ is also a terminating decimal, as $$\frac{3}{30}=\frac{1}{10}$$ and denominator $$10=2*5$$.
Note that if denominator already has only 2-s and/or 5-s then it doesn't matter whether the fraction is reduced or not.
For example $$\frac{x}{2^n5^m}$$, (where x, n and m are integers) will always be terminating decimal.
(We need reducing in case when we have the prime in denominator other then 2 or 5 to see whether it could be reduced. For example fraction $$\frac{6}{15}$$ has 3 as prime in denominator and we need to know if it can be reduced.)
BACK TOT THE ORIGINAL QUESTION:
Question: does $$average=\frac{p}{d}$$ has less than 5 decimal places? Where $$p=prime>100$$ and $$d$$ is the chosen day.
If the chosen day, $$d$$, is NOT of a type $$2^n5^m$$ (where $$n$$ and $$m$$ are nonnegative integers) then $$average=\frac{p}{d}$$ will not be a terminating decimal and thus will have more than 5 decimal places.
How many such days are there of a type $$2^n5^m$$: 1, 2, 4, 5, 8, 10, 16, 20, 25 ($$1=2^0*5^0$$, $$2=2^2$$, $$4=2^2$$, $$5$$, $$8=2^3$$, $$10=2*5$$, $$16=2^4$$, $$20=2^2*5$$, $$25=5^2$$), total of 9 such days (1st of June, 4th of June, ...).
Now, does $$p$$ divided by any of these $$d's$$ have fewer than 5 decimal places? Yes, as $$\frac{p}{d}*10,000=integer$$ for any such $$d$$ (10,000 is divisible by all these numbers: 1, 2, 4, 5, 8, 10, 16, 20, 25).
So, there are 9 such days out of 30 in June: $$P=\frac{9}{30}=\frac{3}{10}$$ .
Answer: D.
Hope it's clear.
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Re: MGMAT Challenge: Decimals on Deposit [#permalink] 19 Jul 2010, 23:37
Bunuel wrote:
bmillan01 wrote:
Every day a certain bank calculates its average daily deposit for that calendar month up to and including that day. If on a randomly chosen day in June the sum of all deposits up to and including that day is a prime integer greater than 100, what is the probability that the average daily deposit up to and including that day contains fewer than 5 decimal places?
(A) 1/10
(B) 2/15
(C) 4/15
(D) 3/10
(E) 11/30
Theory:
Reduced fraction $$\frac{a}{b}$$ (meaning that fraction is already reduced to its lowest term) can be expressed as terminating decimal if and only $$b$$ (denominator) is of the form $$2^n5^m$$, where $$m$$ and $$n$$ are non-negative integers. For example: $$\frac{7}{250}$$ is a terminating decimal $$0.028$$, as $$250$$ (denominator) equals to $$2*5^2$$. Fraction $$\frac{3}{30}$$ is also a terminating decimal, as $$\frac{3}{30}=\frac{1}{10}$$ and denominator $$10=2*5$$.
Note that if denominator already has only 2-s and/or 5-s then it doesn't matter whether the fraction is reduced or not.
For example $$\frac{x}{2^n5^m}$$, (where x, n and m are integers) will always be terminating decimal.
(We need reducing in case when we have the prime in denominator other then 2 or 5 to see whether it could be reduced. For example fraction $$\frac{6}{15}$$ has 3 as prime in denominator and we need to know if it can be reduced.)
BACK TOT THE ORIGINAL QUESTION:
Question: does $$average=\frac{p}{d}$$ has less than 5 decimal places? Where $$p=prime>100$$ and $$d$$ is the chosen day.
If the chosen day, $$d$$, is NOT of a type $$2^n5^m$$ (where $$n$$ and $$m$$ are nonnegative integers) then $$average=\frac{p}{d}$$ will not be a terminating decimal and thus will have more than 5 decimal places.
How many such days are there of a type $$2^n5^m$$: 1, 2, 4, 5, 8, 10, 16, 20, 25 ($$1=2^0*5^0$$, $$2=2^2$$, $$4=2^2$$, $$5$$, $$8=2^3$$, $$10=2*5$$, $$16=2^4$$, $$20=2^2*5$$, $$25=5^2$$), total of 9 such days (1st of June, 4th of June, ...).
Now, does $$p$$ divided by any of these $$d's$$ have fewer than 5 decimal places? Yes, as $$\frac{p}{d}*10,000=integer$$ for any such $$d$$ (10,000 is divisible by all these numbers: 1, 2, 4, 5, 8, 10, 16, 20, 25).
So, there are 9 such days out of 30 in June: $$P=\frac{9}{30}=\frac{3}{10}$$ .
Answer: D.
Hope it's clear.
Great explanation!!! I learn a lot from this
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Re: MGMAT Challenge: Decimals on Deposit [#permalink] 21 Jul 2010, 10:56
bunuel... this is great. thanks...
the way you piece it together is sometimes scary... just curious - what was your gmat score
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Re: MGMAT Challenge: Decimals on Deposit [#permalink] 21 Jul 2010, 11:21
Actually wanted to seek 1 clarification to better understand this:
p/d *10,000=integer
p is a prime integer greater than 100
d can be one of the 9 numbers
To test the tendency to leave a certain desired number of decimal places, upon division of p by d why is it ok to multiply p by a common multiple (10k here) of the 9 numbers in the denominator?
very crude general example (which I am hoping is an analogy):
37 divided by 7 leaves R of 2 and certain decimal places; 37 * 14 divided by 7 leaves no remainder ---> how can the later scenario be used to test whether a certain desired number of decimal places are left by the first scenario...
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Re: MGMAT Challenge: Decimals on Deposit [#permalink] 21 Jul 2010, 12:13
Expert's post
gmat1011 wrote:
Actually wanted to seek 1 clarification to better understand this:
p/d *10,000=integer
p is a prime integer greater than 100
d can be one of the 9 numbers
To test the tendency to leave a certain desired number of decimal places, upon division of p by d why is it ok to multiply p by a common multiple (10k here) of the 9 numbers in the denominator?
very crude general example (which I am hoping is an analogy):
37 divided by 7 leaves R of 2 and certain decimal places; 37 * 14 divided by 7 leaves no remainder ---> how can the later scenario be used to test whether a certain desired number of decimal places are left by the first scenario...
Your example is not good as $$\frac{37}{7}$$ will be recurring decimal (will have infinite number of decimal places).
How many decimal places will terminating decimal $$\frac{p}{2^n*5^m}$$ have? (p is prime number)
Consider following examples:
$$0.2$$ has 1 decimal place --> 1.2*10=12=integer (multiplying by 10 with 1 zero);
$$0.25$$ has 2 decimal places --> 1.25*10^2=125=integer (multiplying by 100 with 2 zeros);
$$0.257$$ has 3 decimal places --> 1.257*10^3=1257=integer (multiplying by 100 with 3 zeros);
$$0.2571$$ has 4 decimal places --> 1.2571*10^4=12571=integer (multiplying by 100 with 4 zeros);
...
So, terminating decimal, $$\frac{p}{2^n*5^m}$$ (where p is prime number), will have $$k$$ decimal places, where $$k$$ is the least value in $$10^k$$ for which $$\frac{p}{2^n*5^m}*10^k=integer$$.
In our original question least value of $$k$$ for which $$\frac{p}{d}*10^k=integer$$, for all 9 d's, is 4 or when $$10^k=10,000$$ (k=4 is needed when d=16).
Hope it's clear.
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Re: MGMAT Challenge: Decimals on Deposit [#permalink] 22 Jul 2010, 03:22
Great - many thanks.
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Re: MGMAT Challenge: Decimals on Deposit [#permalink] 23 Jul 2010, 04:03
awesome explanation!
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Re: MGMAT Challenge: Decimals on Deposit [#permalink] 23 Jul 2010, 05:36
Brilliant explanation. Never knew that dividing by (2^m)(5^n) gives a terminating decimal .. Thanks for the info
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Re: MGMAT Challenge: Decimals on Deposit [#permalink] 23 Jul 2010, 08:09
Thanks for the explanation Bunuel
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Re: MGMAT Challenge: Decimals on Deposit [#permalink] 23 Jul 2010, 19:54
Thanks for the explanation....
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Re: MGMAT Challenge: Decimals on Deposit [#permalink] 19 Sep 2010, 04:40
This is definitely a 800+ question
Good explanation and thnx for the theory, very useful!
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Re: MGMAT Challenge: Decimals on Deposit [#permalink] 06 Oct 2010, 16:18
One question about this problem. The problem doesn't ask if the decimal will be terminating, but rather if the decimal will have less than 5 places. Your solution checks for termination, but how do you check for the number of decimal places? Couldn't some of the possibilities result in termination with more than 5 decimal places?
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Re: MGMAT Challenge: Decimals on Deposit [#permalink] 07 Oct 2010, 01:10
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TehJay wrote:
One question about this problem. The problem doesn't ask if the decimal will be terminating, but rather if the decimal will have less than 5 places. Your solution checks for termination, but how do you check for the number of decimal places? Couldn't some of the possibilities result in termination with more than 5 decimal places?
You should read the last part:
"Now, does $$p$$ divided by any of these $$d's$$ have fewer than 5 decimal places? Yes, as $$\frac{p}{d}*10,000=integer$$ for any such $$d$$ (10,000 is divisible by all these numbers: 1, 2, 4, 5, 8, 10, 16, 20, 25).
So, there are 9 such days out of 30 in June: $$P=\frac{9}{30}=\frac{3}{10}$$ .
Answer: D."
This issue is also discussed in the posts following the one with solution.
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Re: MGMAT Challenge: Decimals on Deposit [#permalink] 08 Oct 2010, 14:39
Bunuel, is it important to know that the numerator in this problem is greater than 100?
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Re: MGMAT Challenge: Decimals on Deposit [#permalink] 28 Jan 2011, 07:29
Bunuel wrote:
bmillan01 wrote:
Every day a certain bank calculates its average daily deposit for that calendar month up to and including that day. If on a randomly chosen day in June the sum of all deposits up to and including that day is a prime integer greater than 100, what is the probability that the average daily deposit up to and including that day contains fewer than 5 decimal places?
(A) 1/10
(B) 2/15
(C) 4/15
(D) 3/10
(E) 11/30
Theory:
Reduced fraction $$\frac{a}{b}$$ (meaning that fraction is already reduced to its lowest term) can be expressed as terminating decimal if and only $$b$$ (denominator) is of the form $$2^n5^m$$, where $$m$$ and $$n$$ are non-negative integers. For example: $$\frac{7}{250}$$ is a terminating decimal $$0.028$$, as $$250$$ (denominator) equals to $$2*5^2$$. Fraction $$\frac{3}{30}$$ is also a terminating decimal, as $$\frac{3}{30}=\frac{1}{10}$$ and denominator $$10=2*5$$.
Note that if denominator already has only 2-s and/or 5-s then it doesn't matter whether the fraction is reduced or not.
For example $$\frac{x}{2^n5^m}$$, (where x, n and m are integers) will always be terminating decimal.
(We need reducing in case when we have the prime in denominator other then 2 or 5 to see whether it could be reduced. For example fraction $$\frac{6}{15}$$ has 3 as prime in denominator and we need to know if it can be reduced.)
BACK TOT THE ORIGINAL QUESTION:
Question: does $$average=\frac{p}{d}$$ has less than 5 decimal places? Where $$p=prime>100$$ and $$d$$ is the chosen day.
If the chosen day, $$d$$, is NOT of a type $$2^n5^m$$ (where $$n$$ and $$m$$ are nonnegative integers) then $$average=\frac{p}{d}$$ will not be a terminating decimal and thus will have more than 5 decimal places.
How many such days are there of a type $$2^n5^m$$: 1, 2, 4, 5, 8, 10, 16, 20, 25 ($$1=2^0*5^0$$, $$2=2^2$$, $$4=2^2$$, $$5$$, $$8=2^3$$, $$10=2*5$$, $$16=2^4$$, $$20=2^2*5$$, $$25=5^2$$), total of 9 such days (1st of June, 4th of June, ...).
Now, does $$p$$ divided by any of these $$d's$$ have fewer than 5 decimal places? Yes, as $$\frac{p}{d}*10,000=integer$$ for any such $$d$$ (10,000 is divisible by all these numbers: 1, 2, 4, 5, 8, 10, 16, 20, 25).
So, there are 9 such days out of 30 in June: $$P=\frac{9}{30}=\frac{3}{10}$$ .
Answer: D.
Hope it's clear.
So you're saying that by controlling the terminating decimal using d=2^m*5^n and, and you can make it an integer by multiplying it by 10000 (if the number must be five decimal places to the left.
Therefore, you can choose of days 1, 2, 4, 5, 8, 10, 16, 20, or 25. (making that 9 days). - But they're not prime??? What am I missing here... I'm the slow one of the lot please help me out
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Re: MGMAT Challenge: Decimals on Deposit [#permalink] 28 Jan 2011, 07:44
Expert's post
mariyea wrote:
Bunuel wrote:
bmillan01 wrote:
Every day a certain bank calculates its average daily deposit for that calendar month up to and including that day. If on a randomly chosen day in June the sum of all deposits up to and including that day is a prime integer greater than 100, what is the probability that the average daily deposit up to and including that day contains fewer than 5 decimal places?
(A) 1/10
(B) 2/15
(C) 4/15
(D) 3/10
(E) 11/30
Theory:
Reduced fraction $$\frac{a}{b}$$ (meaning that fraction is already reduced to its lowest term) can be expressed as terminating decimal if and only $$b$$ (denominator) is of the form $$2^n5^m$$, where $$m$$ and $$n$$ are non-negative integers. For example: $$\frac{7}{250}$$ is a terminating decimal $$0.028$$, as $$250$$ (denominator) equals to $$2*5^2$$. Fraction $$\frac{3}{30}$$ is also a terminating decimal, as $$\frac{3}{30}=\frac{1}{10}$$ and denominator $$10=2*5$$.
Note that if denominator already has only 2-s and/or 5-s then it doesn't matter whether the fraction is reduced or not.
For example $$\frac{x}{2^n5^m}$$, (where x, n and m are integers) will always be terminating decimal.
(We need reducing in case when we have the prime in denominator other then 2 or 5 to see whether it could be reduced. For example fraction $$\frac{6}{15}$$ has 3 as prime in denominator and we need to know if it can be reduced.)
BACK TOT THE ORIGINAL QUESTION:
Question: does $$average=\frac{p}{d}$$ has less than 5 decimal places? Where $$p=prime>100$$ and $$d$$ is the chosen day.
If the chosen day, $$d$$, is NOT of a type $$2^n5^m$$ (where $$n$$ and $$m$$ are nonnegative integers) then $$average=\frac{p}{d}$$ will not be a terminating decimal and thus will have more than 5 decimal places.
How many such days are there of a type $$2^n5^m$$: 1, 2, 4, 5, 8, 10, 16, 20, 25 ($$1=2^0*5^0$$, $$2=2^2$$, $$4=2^2$$, $$5$$, $$8=2^3$$, $$10=2*5$$, $$16=2^4$$, $$20=2^2*5$$, $$25=5^2$$), total of 9 such days (1st of June, 4th of June, ...).
Now, does $$p$$ divided by any of these $$d's$$ have fewer than 5 decimal places? Yes, as $$\frac{p}{d}*10,000=integer$$ for any such $$d$$ (10,000 is divisible by all these numbers: 1, 2, 4, 5, 8, 10, 16, 20, 25).
So, there are 9 such days out of 30 in June: $$P=\frac{9}{30}=\frac{3}{10}$$ .
Answer: D.
Hope it's clear.
So you're saying that by controlling the terminating decimal using d=2^m*5^n and, and you can make it an integer by multiplying it by 10000 (if the number must be five decimal places to the left.
Therefore, you can choose of days 1, 2, 4, 5, 8, 10, 16, 20, or 25. (making that 9 days). - But they're not prime??? What am I missing here... I'm the slow one of the lot please help me out
Nominator is a prime number>100 (on a randomly chosen day in June the sum of all deposits up to and including that day is a prime integer greater than 100) and denominator is that day: {the average daily deposit}={sum of deposits up to and including that day}/{# of days}=p/d (so denominator d must not be a prime it should be of a type d=2^m*5^n. It's nominator p which is given to be a prime>100).
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Re: MGMAT Challenge: Decimals on Deposit [#permalink] 28 Jan 2011, 07:54
Bunuel wrote:
Nominator is a prime number>100 (on a randomly chosen day in June the sum of all deposits up to and including that day is a prime integer greater than 100) and denominator is that day: {the average daily deposit}={sum of deposits up to and including that day}/{# of days}=p/d.
Oh so since we are limited to having five decimal places we were able to control that by choosing a using a denominator that gives us a terminating decimal and we multiply that by 10000 to make that number greater than 100. And the denominator is the 30 days out of which we can choose the 9 days.
But if the Nominator is supposed to be a prime number then we are either supposed to choose from 2 and 5 and nothingelse. Please have patience with me. I just need to understand.
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Re: MGMAT Challenge: Decimals on Deposit [#permalink] 28 Jan 2011, 08:11
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mariyea wrote:
Bunuel wrote:
Nominator is a prime number>100 (on a randomly chosen day in June the sum of all deposits up to and including that day is a prime integer greater than 100) and denominator is that day: {the average daily deposit}={sum of deposits up to and including that day}/{# of days}=p/d.
Oh so since we are limited to having five decimal places we were able to control that by choosing a using a denominator that gives us a terminating decimal and we multiply that by 10000 to make that number greater than 100. And the denominator is the 30 days out of which we can choose the 9 days.
But if the Nominator is supposed to be a prime number then we are either supposed to choose from 2 and 5 and nothingelse. Please have patience with me. I just need to understand.
I'm not sure understood your question.
Anyway: $$average=\frac{prime}{day}$$. In order this value (p/d) to be terminating decimal $$d$$ must be of a type $$2^n5^m$$. Because if the chosen day, $$d$$, is NOT of a type $$2^n5^m$$ then $$average=\frac{p}{d}$$ will not be a terminating decimal and thus will have more than 5 decimal places.
There are 9 such days: 1, 2, 4, 5, 8, 10, 16, 20, 25. For example $$average=\frac{prime}{1}$$ or $$average=\frac{prime}{2}$$ or $$average=\frac{prime}{4}$$, ..., $$average=\frac{prime}{25}$$ all will be terminating decimals (and for ALL other values of d: 3, 6, 7, ... p/d will be recurring decimal thus will have infinite number of decimal places so more than 5). Also for all these 9 values of d average=p/d not only be terminating decimal but also will have fewer than 5 decimal places ($$average=\frac{prime}{16}$$ will have max # of decimal places which is 4).
Hope it's clear.
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Re: MGMAT Challenge: Decimals on Deposit [#permalink] 28 Jan 2011, 11:38
Bunuel wrote:
mariyea wrote:
Bunuel wrote:
Nominator is a prime number>100 (on a randomly chosen day in June the sum of all deposits up to and including that day is a prime integer greater than 100) and denominator is that day: {the average daily deposit}={sum of deposits up to and including that day}/{# of days}=p/d.
Oh so since we are limited to having five decimal places we were able to control that by choosing a using a denominator that gives us a terminating decimal and we multiply that by 10000 to make that number greater than 100. And the denominator is the 30 days out of which we can choose the 9 days.
But if the Nominator is supposed to be a prime number then we are either supposed to choose from 2 and 5 and nothingelse. Please have patience with me. I just need to understand.
I'm not sure understood your question.
Anyway: $$average=\frac{prime}{day}$$. In order this value (p/d) to be terminating decimal $$d$$ must be of a type $$2^n5^m$$. Because if the chosen day, $$d$$, is NOT of a type $$2^n5^m$$ then $$average=\frac{p}{d}$$ will not be a terminating decimal and thus will have more than 5 decimal places.
There are 9 such days: 1, 2, 4, 5, 8, 10, 16, 20, 25. For example $$average=\frac{prime}{1}$$ or $$average=\frac{prime}{2}$$ or $$average=\frac{prime}{4}$$, ..., $$average=\frac{prime}{25}$$ all will be terminating decimals (and for ALL other values of d: 3, 6, 7, ... p/d will be recurring decimal thus will have infinite number of decimal places so more than 5). Also for all these 9 values of d average=p/d not only be terminating decimal but also will have fewer than 5 decimal places ($$average=\frac{prime}{16}$$ will have max # of decimal places which is 4).
Hope it's clear.
I understand now Thank you so much!
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Re: MGMAT Challenge: Decimals on Deposit [#permalink] 28 Jan 2011, 11:38
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https://www.mtosmt.org/issues/mto.11.17.3/mto.11.17.3.spicer.html | (Per)Form in(g) Rock: A Response *
Mark Spicer
Volume 17, Number 3, October 2011
[1] Theodor Adorno is no doubt rolling in his grave at the very thought of a Society for Music Theory special session—and now a special issue of Music Theory Online—devoted to the subject of form in rock music, yet these seven articles go a long way towards demonstrating that the form of a pop or rock song need not be trite nor simplistic, nor—dare I say it—formulaic. As the invited respondent, it is part of my job to take issue with any ideas in these essays that seem suspect to me, yet the arguments and analyses offered by these authors are, for the most part, so well thought out that I have little to say in the way of additional criticism. Instead, I have chosen to frame my response around some analyses of my own that were sparked by certain ideas raised among the four papers from the original SMT session (Doll, Koozin, Osborn, and Summach). I will offer my initial reaction to the other three papers (Attas, Endrinal, and Nobile) by way of a short postscript.
Example 1. Talk Talk, “It’s My Life” (1984)
(click to enlarge)
Audio Example 1. Talk Talk, “It’s My Life” (1984)
[2] I love the Eighties, so I will begin by considering the harmonic and formal design of one of my favorite tracks from that decade, Talk Talk’s 1984 hit “It’s My Life,” an abbreviated transcription of which is provided in Example 1.(1) I used this example once before in a talk I gave a few years back on the subject of what makes a great chorus in a pop and rock song (Spicer 2005); it is a good thing I never published that paper, since I must admit that I made a few errors in transcribing the pitch content of “It’s My Life,” which I have now corrected for this updated analysis.
[3] As with many 1980s synthpop songs, little to no guitar is to be found on this track. The drum kit is relentless, rarely deviating from a standard rock pattern. Driving the groove is Paul Webb’s trademark fretless electric bass, and above this we are bathed in a wash of synthesizer chords, which I have simplified in my transcription of the verse vamp in Example 1a in order to show its essential voice leading. The harmonic progression here is quite eclectic: basically we have an E Mixolydian I–VII–ii (with the second and third chords in first inversion), but none of the chords is a pure triad since the third is missing from the tonic chord and scale degree 5 is held as an inverted pedal throughout. Not shown in the example, a jabbing two-note syncopated synth riff—working rhythmically in tandem with the bass, accenting the “and” of beats three and four—is sounded during only the first bar of each four-bar cycle. After two times through the vamp, Mark Hollis’s characteristically maudlin lead vocal enters rather unobtrusively on scale degree 3 (hence supplying the missing third of the tonic chord). Audio Example 1 contains the first minute-and-a-half of “It’s My Life,” representing the first pass through the intro, verse, prechorus, and chorus.
[4] Christopher Doll’s article explores the powerful effect of expressive modulations at important formal junctures in pop and rock songs, especially at the onsets of choruses. Example 1b illustrates what happens as the verse moves into the prechorus in “It’s My Life.” I have probably listened to this track hundreds of times over the years, and yet this particular expressive modulation still gives me goose bumps (indeed, Doll would likely describe this as a “breakout prechorus”). As the example shows, the pitches F and C of the ii chord slip down by semitone to E and B, while A is retained as a common tone and enharmonically recast as the leading tone G as part of the V chord in the tritone-related key of A minor. The modulation into the prechorus is thus achieved by what David Lewin famously dubbed the “SLIDE” transformation, in which two opposite-mode triads whose roots are a semitone apart invert around a common third. David Kopp in his book Chromatic Transformations in Nineteenth-Century Music has described the SLIDE as “the consummate common-tone relation, whose harmonic strength...is defined almost wholly by the common tone itself. The relation it represents is more distant than in any other common-tone relation...” (Kopp 2006, 175). I can think of no other pop or rock song that employs such a SLIDE modulation, certainly not as a means of moving into the prechorus.(2) To add to the mounting excitement, from this point on the song’s harmonic rhythm speeds up dramatically, culminating in the driving two-chords-per-bar descending fifths sequence of the chorus proper.
[5] Yet there is another reason why I like this modulation so much, and this has to do with the fact that in the move to A minor we are presented with a series of big, fat synthesizer chords involving only the white keys, and I am immediately reminded of a host of other pop hits from the 1980s that similarly feature big synth chords in C major or A minor. Tim Koozin’s article has demonstrated convincingly how the sheer topography of the guitar fretboard has profound ramifications for the types of riffs and harmonic moves that composers of guitar-based rock are drawn to. While I am no guitarist and therefore cannot relate intimately as Koozin does to the very physicality of these guitar riffs and progressions and how they feel when played, his paper got me thinking about the related notion of keyboard topography and the physical nature of executing certain characteristic keyboard riffs and chord progressions in rock. It should come as no surprise that there are myriad keyboard-based pop and rock songs featuring riffs and progressions involving only the white keys, since, let’s face it, such riffs are much easier to perform without any of those pesky black keys getting in the way.
Example 2. Some other signature “white-key” synth riffs
(click to enlarge)
Audio Example 2. New Order, “The Perfect Kiss” (1985)
Example 3. Some opening “black-key” keyboard riffs from Stevie Wonder songs
(click to enlarge)
[6] Example 2 shows three representative examples of signature “white-key” synth riffs from the 1980s.(3) The first of these is the repeating two-bar syncopated reggae “skank” pattern that sounds throughout the intro and verses of the Police’s “Spirits in the Material World” from the group’s 1981 album Ghost in the Machine (Example 2a). This album marked something of a departure from the Police’s previous three LPs in that keyboards were now added to most of the arrangements; this development, as I have argued elsewhere (Spicer 2010), was a direct response on the Police’s part to the recent demise of punk and the rise of synthpop in the U.K in 1981.(4) The second example is the famous opening Oberheim synthesizer riff from Van Halen’s 1984 hit “Jump,” the song on which Eddie Van Halen gleefully put his guitar aside momentarily to make his keyboard debut with the group (Example 2b). Needless to say, while Eddie remains one of rock’s greatest guitar virtuosi, he was a novice keyboard player at the time of the 1984 album on which “Jump” appeared. The third example is the big white-key synth riff from the chorus of New Order’s 1985 dance hit “The Perfect Kiss” (Example 2c). Audio Example 2 illustrates this riff in the context of how it is first introduced in the track itself, where we are made to wait almost a minute-and-a-half for the big synthesizer chords to make their triumphant entry as the climax of the song’s accumulative beginning.(5)
[7] Still on the subject of keyboard topography, what might be viewed as the direct opposite of this all white-key phenomenon are those keyboard riffs that feature all or almost all black keys. I recall a conversation I had with Tim Hughes several years ago in relation to his excellent dissertation on the music of Stevie Wonder (Hughes 2003). It turns out that many of Wonder’s songs begin with a riff or chord that features all or mostly black keys, which I speculated might have something to do with the notion that a blind person can feel the raised black keys more easily as a point of orientation and would therefore be drawn to those particular chord shapes. Example 3 shows three representative examples of opening riffs from Stevie Wonder songs that are oriented around the black keys, which I invite the reader to play at the keyboard in order to feel how these riffs lie under the hands. The first of these (Example 3a) is the repeating Fender Rhodes electric piano riff from Wonder’s 1973 hit “Living for the City” (#8 U.S., #15 U.K.), in which the major-pentatonic anacrusis figure and opening F major tonic chord involve only black keys.(6) The second is the signature bass riff (Example 3b), doubled by the left hand of the electric piano, which underpins the majority of the groove from Wonder’s 1976 hit “I Wish” (#1 U.S., #5 U.K.); this repeating, circular riff is built around an oscillating E Dorian i–IV progression and features all black keys for its first five notes.(7) The third example shows a transcription of the opening bars of the piano introduction to Wonder’s gorgeous 1982 ballad “Ribbon in the Sky” (Example 3c), where the initial left hand harmony is an all-black-key E minor seventh chord.(8) I could have shown many other examples of “black-key” keyboard riffs from Wonder’s songs—the multiple interlocking clavinet parts to “Superstition” and “Higher Ground” (both 1973), for example, in which the main groove of each song revolves around the pitches of an E minor pentatonic scale—but I shall leave these provocative implications open for further investigation.(9)
[8] Brad Osborn has provided in his article a convincing and comprehensive typology of experimental through-composed forms in post-millennial rock. As he rightly points out, however, with the exception of Radiohead none of the artists he discusses have made much of a dent in the mainstream pop charts. Adorno’s negative criticism of popular music as trite and formulaic notwithstanding, pop and rock hits have long relied on recapitulatory hooks and choruses for their mass appeal, and, as I am sure Osborn would agree, this situation is unlikely to change anytime soon. Which brings us back to 1980s synthpop. Although synthpop as a style largely receded in the 1990s in favor of other styles (most notably grunge and rap), during the first decade of the new millennium the style has enjoyed a resurgence in popularity. This is represented by the work of artists such as Daft Punk, Ke$ha, Ladytron, LCD Soundsystem, and Owl City, to name a few, and also by the fact that a number of R&B and rap artists in recent years have reached back into the canon of classic 1980s synthpop hits as a source of inspiration, one example being Flo Rida’s 2009 #1 smash “Right Round” (featuring Ke$ha), which overtly borrows the chorus to Dead or Alive’s 1985 hit “You Spin Me Round (Like a Record).”(10) None of these post-millennial synthpop acts, however, can match the phenomenal chart success of Lady Gaga over the past couple of years. For my final analysis, I wish to consider the formal design of “Bad Romance,” Gaga’s third single and follow-up to her late-2008 breakthrough hit and 2010 Grammy-winning song “Poker Face.” It just so happens that “Bad Romance” is in A minor and therefore features many big white-key synthesizer chords, further marking the song’s sonic allegiance to its 1980s forebears. “Bad Romance” is cast essentially in a contrasting verse-chorus form (see Covach 2005), with a prechorus and also an extended bridge section towards the end of the song that paves the way for the explosive final chorus. But in addition to all of this, Lady Gaga exploits in this song a rather unusual structural feature, one that could be described as a postchorus.
[9] In his magisterial analytical survey of songs composed during rock’s formative period (through 1969), The Foundations of Rock, Walter Everett claims that “a very common way of joining separate verse and chorus is through the prechorus, a form seemingly invented in 1964 and remaining extremely popular through the remainder of the decade” (Everett 2009, 146). Jay Summach has also done a remarkable job in his article of mining the pop charts of the 1950s and ’60s for forensic evidence that points towards the prechorus having emerged as a full-fledged structural device a few years earlier than Everett suggests—specifically, in 1961 with Del Shannon’s “Runaway.” While I cannot claim to have made a similarly exhaustive investigation of the structural origins of the postchorus, I have managed to locate a handful of candidates for songs with postchoruses reaching back as early as 1970 with two examples from that year: the Jackson 5’s #1 pop hit “ABC” and Stephen Stills’s solo hit “Love the One You’re With.”(11) In both of these songs, the chorus proper is followed by a brief, self-contained passage that can be heard as a departure from the chorus and yet does not serve merely as a transition to the next verse (in the case of “Love the One You’re With,” for example, the postchorus that follows the song’s second and third choruses provides us with one of the song’s most memorable hooks in the form of the wordless “doo-doo doo-doo doo-doo-doo-doo...”).(12)
[10] Rather than saying anything further, I will conclude the main part of this response—with a bang, I hope, the same way I did at the SMT special session—by presenting a streaming, annotated formal diagram of “Bad Romance” that I made using the nifty software program Variations Audio Timeliner,(13) developed by Music Theory Online’s managing editor Brent Yorgason and his former colleagues at Indiana University.(14) So, please pump up the volume, get ready for some big, fat white-key synth chords, and follow along with my formal annotations as they “pop up” onscreen (see Example 4).
(click to enlarge and watch the video)
[11] The three additional articles that have been brought into this special issue on form in rock are all very interesting in their own right, and I shall now comment briefly on each of them in turn. Drew Nobile’s article attempts to do for 1960s pop music what Schmalfeldt 1991 did for classical music by reconciling Schenkerian concepts with traditional and recent theories of form, and in so doing demonstrates how a careful consideration of harmony and voice leading is crucial to our better understanding the formal paradigms that shape this music. Nobile’s study is limited to early (pre-1965) songs by the Beatles cast in good old-fashioned AABA form, but I have no doubt that his analytical approach has the potential also to discover important links among harmony, voice leading, and form in post-1960s pop and rock music, and I look forward to his future work in this regard.
[12] Robin Attas’s article on Sarah McLachlan takes on the prickly subject of what defines a phrase in pop and rock music, highlighting in particular the problems inherent in finding “goal-directedness” in songs built around those repeating, circular harmonic progressions that are so ubiquitous in rock, such as the repeating four-bar vi–IV–I–V (or is it i–VI–III–VII?) chord pattern of “Building a Mystery.” By considering other musical parameters—such as text, rhythm, and melodic contour—that work in conjunction with harmony in creating a sense of goal-directed motion, Attas achieves a more comprehensive definition of phrase for pop and rock than what has previously been offered by other authors.
Endrinal’s Example 5. Reduction of “Mysterious Ways” (1:43-3:16)
(click to enlarge)
Endrinal’s Example 6. Reduction of “Elevation” (1:36-2:52)
(click to enlarge)
[13] Lastly, Christopher Endrinal’s article on U2, as Nicole Biamonte puts it in her introduction, seeks to “problematize” the concept of a “bridge” in a pop or rock song, even going so far as to suggest that we jettison the term entirely and replace it with his new term “interverse.” This surely will incite some controversy among the readers of this journal, and, while I agree with Endrinal that we need to find better ways of explaining those internal sections in complex, multipart rock songs which are clearly not verses nor choruses yet seem self-contained and non-transitional in nature (such as my suggested “postchorus”), his article has not convinced me to burn my bridges just yet. We must remember that what defines a bridge is not only the harmonic contrast it provides from the surrounding verses and choruses but also its retransitional function. In other words, a bridge necessarily begins with some kind of harmonic swerve away from the preceding material and typically culminates in a big V chord (or, less often, another dominant-functioning harmony, such as VII) that sets up a dramatic, fresh reentrance of a verse or chorus, usually on the tonic.(15) Following these criteria, I would not hesitate to call the “independent continuous interverse” in “Mysterious Ways” (Endrinal’s Example 5) a bridge. Complicating the issue of a bridge’s retransitional function, however, are those situations in which the ensuing verse or chorus begins off-tonic, such as in “Elevation” (Endrinal’s Example 6), where the bridge—what Endrinal calls an “independent sectional interverse”—ends on I and the chorus begins on V. If James Brown ever decides to update the lyrics to his 1970 funk classic “Sex Machine” to ask “Should I take ’em to the interverse?” then I might reconsider my allegiance to the term bridge, but for now I shall leave it up to the readers of MTO to decide for themselves.
Mark Spicer
Department of Music
Hunter College and the Graduate Center
City University of New York
mark.spicer@hunter.cuny.edu
Works Cited
Brungard, Rachael C. 2010. “‘From the Top of the Pole, I Watch Her Go Down’: The Appropriation, Heterosexualization, and Masculinization of Dead or Alive’s ‘You Spin Me Round (Like a Record).’” Paper presented at the conference “Popular Music: Then and Now,” American Musicological Society, Greater New York Chapter.
Brungard, Rachael C. 2010. “‘From the Top of the Pole, I Watch Her Go Down’: The Appropriation, Heterosexualization, and Masculinization of Dead or Alive’s ‘You Spin Me Round (Like a Record).’” Paper presented at the conference “Popular Music: Then and Now,” American Musicological Society, Greater New York Chapter.
Covach, John. 2005. “Form in Rock Music: A Primer.” In Engaging Music: Essays in Music Analysis, ed. Deborah Stein, 65–76. New York: Oxford University Press.
Covach, John. 2005. “Form in Rock Music: A Primer.” In Engaging Music: Essays in Music Analysis, ed. Deborah Stein, 65–76. New York: Oxford University Press.
Everett, Walter. 2009. The Foundations of Rock: From “Blue Suede Shoes” to “Suite: Judy Blue Eyes.” New York: Oxford University Press.
Everett, Walter. 2009. The Foundations of Rock: From “Blue Suede Shoes” to “Suite: Judy Blue Eyes.” New York: Oxford University Press.
Holm-Hudson, Kevin. 2010. “A Study of Maximally Smooth Voice Leading in the Mid-1970s Music of Genesis.” In Sounding Out Pop: Analytical Essays in Popular Music, ed. Mark Spicer and John Covach, 99–123. Ann Arbor: University of Michigan Press.
Holm-Hudson, Kevin. 2010. “A Study of Maximally Smooth Voice Leading in the Mid-1970s Music of Genesis.” In Sounding Out Pop: Analytical Essays in Popular Music, ed. Mark Spicer and John Covach, 99–123. Ann Arbor: University of Michigan Press.
Hughes, Tim. 2003. “Groove and Flow: Six Analytical Essays on the Music of Stevie Wonder.” PhD diss., University of Washington.
Hughes, Tim. 2003. “Groove and Flow: Six Analytical Essays on the Music of Stevie Wonder.” PhD diss., University of Washington.
Hughes, Tim. 2008. “Trapped within the Wheels: Flow and Repetition, Modernism and Tradition in Stevie Wonder’s ‘Living for the City.’” In Expression in Pop-Rock Music: Critical and Analytical Essays, 2nd ed., ed. Walter Everett, 239–65. New York: Routledge.
—————. 2008. “Trapped within the Wheels: Flow and Repetition, Modernism and Tradition in Stevie Wonder’s ‘Living for the City.’” In Expression in Pop-Rock Music: Critical and Analytical Essays, 2nd ed., ed. Walter Everett, 239–65. New York: Routledge.
Kopp, David. 2006. Chromatic Transformations in Nineteenth-Century Music. Cambridge: Cambridge University Press.
Kopp, David. 2006. Chromatic Transformations in Nineteenth-Century Music. Cambridge: Cambridge University Press.
Molenda, Michael. 2007. “Harmo-Melodic Spaceman: How Andy Summers Employed Chord Fragments and an Echoplex to Change the Sound of Rock Guitar.” Guitar Player (June): 86–97, 152.
Molenda, Michael. 2007. “Harmo-Melodic Spaceman: How Andy Summers Employed Chord Fragments and an Echoplex to Change the Sound of Rock Guitar.” Guitar Player (June): 86–97, 152.
Schmalfeldt, Janet. 1991. “Towards a Reconciliation of Schenkerian Concepts with Traditional and Recent Theories of Form.” Music Analysis 10, no. 3: 233–87.
Schmalfeldt, Janet. 1991. “Towards a Reconciliation of Schenkerian Concepts with Traditional and Recent Theories of Form.” Music Analysis 10, no. 3: 233–87.
Spicer, Mark. 2004. “(Ac)cumulative Form in Pop-Rock Music.” twentieth-century music 1, no. 1: 29–64.
Spicer, Mark. 2004. “(Ac)cumulative Form in Pop-Rock Music.” twentieth-century music 1, no. 1: 29–64.
Spicer, Mark. 2005. “What Makes a Great Chorus?” Paper presented at the Fourth Biennial International Conference on Music Since 1900, University of Sussex; earlier versions presented at the annual conference of the International Association for the Study of Popular Music (U.S.), University of Virginia, October 2004, and as the keynote address for the City University of New York Graduate Students in Music Symposium, April 2004.
—————. 2005. “What Makes a Great Chorus?” Paper presented at the Fourth Biennial International Conference on Music Since 1900, University of Sussex; earlier versions presented at the annual conference of the International Association for the Study of Popular Music (U.S.), University of Virginia, October 2004, and as the keynote address for the City University of New York Graduate Students in Music Symposium, April 2004.
Spicer, Mark. 2009. “Absent Tonics in Pop and Rock Songs.” Paper presented at the annual meeting of the Society for Music Theory, Montréal.
—————. 2009. “Absent Tonics in Pop and Rock Songs.” Paper presented at the annual meeting of the Society for Music Theory, Montréal.
Spicer, Mark. 2010. “‘Reggatta de Blanc’: Analyzing Style in the Music of the Police.” In Sounding Out Pop: Analytical Essays in Popular Music, ed. Mark Spicer and John Covach, 124–53. Ann Arbor: University of Michigan Press.
—————. 2010. “‘Reggatta de Blanc’: Analyzing Style in the Music of the Police.” In Sounding Out Pop: Analytical Essays in Popular Music, ed. Mark Spicer and John Covach, 124–53. Ann Arbor: University of Michigan Press.
Footnotes
* I wish to thank Christopher Segall for his expert assistance in setting all of the musical examples for this article.
I wish to thank Christopher Segall for his expert assistance in setting all of the musical examples for this article.
1. Emerging on the U.K. music scene in 1982, Talk Talk was quickly placed by the critics alongside the several other “New Romantic” groups that were dominating the British charts that year (Talk Talk shared the same producer and idea of a double-barreled band name as their EMI label mates Duran Duran). The group went on to reinvent themselves in the later 1980s with what might be described as a fusion of progressive rock and synthpop, incorporating influences from jazz and twentieth-century art music into their sound to wide critical acclaim. In the U.S., however, “It’s My Life” was Talk Talk’s only hit, fueled by constant exposure on MTV at the height of the so-called second British Invasion. As an homage to 1980s U.K. synthpop, the California group No Doubt released their cover version of “It’s My Life” as a single in 2003, which rose as high as #10 on Billboard’s Hot 100 (#17 U.K.).
2. SLIDE progressions are rare within the relatively simple harmonic language characteristic of most 1980s synthpop, yet such progressions are quite common in other keyboard-dominated pop and rock styles, especially 1970s progressive rock. Genesis’s keyboardist Tony Banks, for example, was markedly influenced by the nineteenth-century piano music he had learned as a teenager, and was particularly fond of using the SLIDE and other “maximally smooth” oddball chord progressions in his own compositions; see Holm-Hudson 2010.
3. I performed the first two of these riffs (along with the Stevie Wonder riffs in Example 3) live during the SMT special session, but one can easily find online streaming audio versions of all the tracks discussed in this article at YouTube.com and elsewhere.
4. It was Sting’s idea to fatten the arrangements on Ghost in the Machine with all the synthesizers, but guitarist Andy Summers did not see this as a step forward: “All those layers were there because it was a group head trip we went through that wasn’t exactly welcomed by me. I would say, ‘F**k the keyboard part—I can play it all on guitar.’ But these things happened anyway. I’d just try to blend with the synths and keep the guitar part strong” (Molenda 2007, 91).
5. The 1985 music video for “The Perfect Kiss,” directed by Jonathan Demme, presents an intimate view of New Order performing the song live at their Factory Records studio in Manchester. One can watch the accumulative beginning to the song unfold as the camera zooms in on the band members one after another, introducing their respective parts one by one. For a close analysis of the similar accumulative beginning from New Order’s 1983 hit “Blue Monday” (a song which, cast exclusively in D Dorian, also features lots of white-key synth riffs), see Spicer 2004, 39–42.
6. For a thought-provoking analysis of “Living for the City,” see Hughes 2008. Hughes chooses to notate the electric piano riff with a key signature of three sharps (suggesting F minor), but I prefer to show the riff primarily in F major, with the As and Es as “blue” notes ($\stackrel{̂}{3}$ and $\stackrel{ˆ}{7}$) borrowed from the minor pentatonic.
7. The bass guitar in “I Wish” jumps back and forth between its upper and lower octaves for the second through fifth notes of the riff (GABA), but the left hand of the electric piano always plays the riff within a single octave as notated here, which requires no change of hand position.
8. The initial E minor seventh chord in “Ribbon in the Sky” is actually not the tonic chord (it functions as ii7, hence the key signature of five flats). We must wait over a minute and a half for the D major tonic finally to emerge as the goal of the refrain following the song’s second verse. For a detailed harmonic analysis of “Ribbon in the Sky” and other pop and rock songs with “emergent” or “absent” tonics, see Spicer 2009.
9. In making this distinction between “white-key” and “black-key” riffs, my intention is to highlight the physical differences in feeling out and performing these riffs at the keyboard (with the raised black keys possibly being more accessible to a blind person) and really has nothing to do with race, yet one of the anonymous MTO reviewers assumed by “provocative implications” that I was hinting at the fact that all of my white-key riffs in Example 2 are from songs by white artists while Stevie Wonder, of course, is a black artist. Echoing Wonder’s own hit duet with Paul McCartney, “Ebony and Ivory” (1982), it is perhaps tempting to make an analogy between the adjacent black and white keys on the piano and the notion of blacks and whites “liv[ing] together in perfect harmony,” but a thorough exploration of these implications lies beyond the scope of the present article. Taking the bait and this idea a little further, however, I can think of a number of keyboard-driven R&B hits from the 1980s by black artists that feature predominantly black-key synth riffs; two of my favorites, both in E minor, are Rufus and Chaka Khan’s “Ain’t Nobody” (1983) and Jocelyn Brown’s “Somebody Else’s Guy” (1984).
10. For a probing analysis of this bawdy Flo Rida song (and video) and its appropriation of the earlier Dead or Alive song, see Brungard 2010.
11. I thank Jay Summach and Nicole Biamonte respectively for suggesting to me “ABC” and “Love the One You’re With” as early examples of songs with postchoruses. I can think of no such examples prior to these two hits from 1970, which may explain why Everett 2009 (which traces the foundations of rock through 1969) makes no mention of the postchorus as a structural device. I must also thank Christopher White for alerting me within just a few days of the song’s release in late 2009 to the possibility of a postchorus in “Bad Romance.” A short list of other representative examples of songs with postchoruses would include Thin Lizzy’s 1976 hit “The Boys are Back in Town” (in which the postchorus is purely instrumental), Wham’s 1984 transatlantic #1 hit “Wake Me Up Before You Go Go,” and Lady Gaga’s own “Poker Face.”
12. Some might argue against the term “postchorus” in favor of describing such a section instead as a chorus-ending refrain. I prefer the description postchorus if a song’s chorus is followed by what sounds like a new section (or “module,” as Summach would say) that is essentially self-contained, even if this amounts to just a couple of repeated lines (as in “Poker Face”). This subtle distinction can be illustrated by comparing the postchoruses in the Jackson 5’s “ABC” to the chorus-ending refrains in their precursor #1 hit “I Want You Back” (released December 1969).
14. I am not the only musician to admire Lady Gaga for her skill in crafting irresistibly catchy pop songs overloaded with hooks. For its December 9, 2010 issue, Rolling Stone asked fifty current artists to provide a playlist of ten of their favorite tracks, and “Bad Romance” appeared as #10 on Elton John’s list of “New Pop Classics”; as John puts it, “Lady Gaga is a massive talent. ... When I did the Rainforest benefit with Bruce Springsteen, he said, ‘“Bad Romance” is such a great song.’ And I can hear him singing that. Musicians who write songs think she’s pretty damn good” (Rolling Stone 1119: 44). My analysis of “Bad Romance” is based on the original single version (heard also on her 2009 album The Fame Monster), which, as I have noted in my annotated formal diagram, opens with a truncated statement of the chorus (“Oh-oh-oh-oh ... caught in a bad romance”) followed by the postchorus (“rah-rah ah-ah-ah-ah ... ”). In live performances of “Bad Romance” (such as her performance of the song at the 2010 Grammy Awards), however, Gaga will often begin with the postchorus—which, of course, complicates the very issue of its formal designation.
15. Indeed, “old school” bridges culminating in big retransitional dominants remain alive and well on today’s pop charts; take a listen, for example, to Cee Lo Green’s recent (2010) top-ten smash “F**k [Forget] You,” the bridge of which is really two bridges in one, comprising two back-to-back eight-bar modules (a “middle sixteen,” if you will).
Emerging on the U.K. music scene in 1982, Talk Talk was quickly placed by the critics alongside the several other “New Romantic” groups that were dominating the British charts that year (Talk Talk shared the same producer and idea of a double-barreled band name as their EMI label mates Duran Duran). The group went on to reinvent themselves in the later 1980s with what might be described as a fusion of progressive rock and synthpop, incorporating influences from jazz and twentieth-century art music into their sound to wide critical acclaim. In the U.S., however, “It’s My Life” was Talk Talk’s only hit, fueled by constant exposure on MTV at the height of the so-called second British Invasion. As an homage to 1980s U.K. synthpop, the California group No Doubt released their cover version of “It’s My Life” as a single in 2003, which rose as high as #10 on Billboard’s Hot 100 (#17 U.K.).
SLIDE progressions are rare within the relatively simple harmonic language characteristic of most 1980s synthpop, yet such progressions are quite common in other keyboard-dominated pop and rock styles, especially 1970s progressive rock. Genesis’s keyboardist Tony Banks, for example, was markedly influenced by the nineteenth-century piano music he had learned as a teenager, and was particularly fond of using the SLIDE and other “maximally smooth” oddball chord progressions in his own compositions; see Holm-Hudson 2010.
I performed the first two of these riffs (along with the Stevie Wonder riffs in Example 3) live during the SMT special session, but one can easily find online streaming audio versions of all the tracks discussed in this article at YouTube.com and elsewhere.
It was Sting’s idea to fatten the arrangements on Ghost in the Machine with all the synthesizers, but guitarist Andy Summers did not see this as a step forward: “All those layers were there because it was a group head trip we went through that wasn’t exactly welcomed by me. I would say, ‘F**k the keyboard part—I can play it all on guitar.’ But these things happened anyway. I’d just try to blend with the synths and keep the guitar part strong” (Molenda 2007, 91).
The 1985 music video for “The Perfect Kiss,” directed by Jonathan Demme, presents an intimate view of New Order performing the song live at their Factory Records studio in Manchester. One can watch the accumulative beginning to the song unfold as the camera zooms in on the band members one after another, introducing their respective parts one by one. For a close analysis of the similar accumulative beginning from New Order’s 1983 hit “Blue Monday” (a song which, cast exclusively in D Dorian, also features lots of white-key synth riffs), see Spicer 2004, 39–42.
For a thought-provoking analysis of “Living for the City,” see Hughes 2008. Hughes chooses to notate the electric piano riff with a key signature of three sharps (suggesting F minor), but I prefer to show the riff primarily in F major, with the As and Es as “blue” notes ($\stackrel{̂}{3}$ and $\stackrel{ˆ}{7}$) borrowed from the minor pentatonic.
The bass guitar in “I Wish” jumps back and forth between its upper and lower octaves for the second through fifth notes of the riff (GABA), but the left hand of the electric piano always plays the riff within a single octave as notated here, which requires no change of hand position.
The initial E minor seventh chord in “Ribbon in the Sky” is actually not the tonic chord (it functions as ii7, hence the key signature of five flats). We must wait over a minute and a half for the D major tonic finally to emerge as the goal of the refrain following the song’s second verse. For a detailed harmonic analysis of “Ribbon in the Sky” and other pop and rock songs with “emergent” or “absent” tonics, see Spicer 2009.
In making this distinction between “white-key” and “black-key” riffs, my intention is to highlight the physical differences in feeling out and performing these riffs at the keyboard (with the raised black keys possibly being more accessible to a blind person) and really has nothing to do with race, yet one of the anonymous MTO reviewers assumed by “provocative implications” that I was hinting at the fact that all of my white-key riffs in Example 2 are from songs by white artists while Stevie Wonder, of course, is a black artist. Echoing Wonder’s own hit duet with Paul McCartney, “Ebony and Ivory” (1982), it is perhaps tempting to make an analogy between the adjacent black and white keys on the piano and the notion of blacks and whites “liv[ing] together in perfect harmony,” but a thorough exploration of these implications lies beyond the scope of the present article. Taking the bait and this idea a little further, however, I can think of a number of keyboard-driven R&B hits from the 1980s by black artists that feature predominantly black-key synth riffs; two of my favorites, both in E minor, are Rufus and Chaka Khan’s “Ain’t Nobody” (1983) and Jocelyn Brown’s “Somebody Else’s Guy” (1984).
For a probing analysis of this bawdy Flo Rida song (and video) and its appropriation of the earlier Dead or Alive song, see Brungard 2010.
I thank Jay Summach and Nicole Biamonte respectively for suggesting to me “ABC” and “Love the One You’re With” as early examples of songs with postchoruses. I can think of no such examples prior to these two hits from 1970, which may explain why Everett 2009 (which traces the foundations of rock through 1969) makes no mention of the postchorus as a structural device. I must also thank Christopher White for alerting me within just a few days of the song’s release in late 2009 to the possibility of a postchorus in “Bad Romance.” A short list of other representative examples of songs with postchoruses would include Thin Lizzy’s 1976 hit “The Boys are Back in Town” (in which the postchorus is purely instrumental), Wham’s 1984 transatlantic #1 hit “Wake Me Up Before You Go Go,” and Lady Gaga’s own “Poker Face.”
Some might argue against the term “postchorus” in favor of describing such a section instead as a chorus-ending refrain. I prefer the description postchorus if a song’s chorus is followed by what sounds like a new section (or “module,” as Summach would say) that is essentially self-contained, even if this amounts to just a couple of repeated lines (as in “Poker Face”). This subtle distinction can be illustrated by comparing the postchoruses in the Jackson 5’s “ABC” to the chorus-ending refrains in their precursor #1 hit “I Want You Back” (released December 1969).
I am not the only musician to admire Lady Gaga for her skill in crafting irresistibly catchy pop songs overloaded with hooks. For its December 9, 2010 issue, Rolling Stone asked fifty current artists to provide a playlist of ten of their favorite tracks, and “Bad Romance” appeared as #10 on Elton John’s list of “New Pop Classics”; as John puts it, “Lady Gaga is a massive talent. ... When I did the Rainforest benefit with Bruce Springsteen, he said, ‘“Bad Romance” is such a great song.’ And I can hear him singing that. Musicians who write songs think she’s pretty damn good” (Rolling Stone 1119: 44). My analysis of “Bad Romance” is based on the original single version (heard also on her 2009 album The Fame Monster), which, as I have noted in my annotated formal diagram, opens with a truncated statement of the chorus (“Oh-oh-oh-oh ... caught in a bad romance”) followed by the postchorus (“rah-rah ah-ah-ah-ah ... ”). In live performances of “Bad Romance” (such as her performance of the song at the 2010 Grammy Awards), however, Gaga will often begin with the postchorus—which, of course, complicates the very issue of its formal designation.
Indeed, “old school” bridges culminating in big retransitional dominants remain alive and well on today’s pop charts; take a listen, for example, to Cee Lo Green’s recent (2010) top-ten smash “F**k [Forget] You,” the bridge of which is really two bridges in one, comprising two back-to-back eight-bar modules (a “middle sixteen,” if you will).
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Number of visits: | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 4, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.29492560029029846, "perplexity": 5439.301026331508}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-21/segments/1620243991641.5/warc/CC-MAIN-20210511025739-20210511055739-00041.warc.gz"} |
https://www.physicsforums.com/threads/acceleration-of-a-brick-involving-integrals.640469/ | Homework Help: Acceleration of a brick, involving integrals
1. Oct 1, 2012
majormaaz
1. The problem statement, all variables and given/known data
A 15 kg brick moves along an x axis. Its acceleration as a function of its position is shown in Fig. 7-32. What is the net work performed on the brick by the force causing the acceleration as the brick moves from x = 0 to x = 8.0 m?
2. Relevant equations
W = FΔx = max
3. The attempt at a solution
I haven't taken calculus prior to the class(am taking it now), and I was just introduced to integrals today by a friend. He showed me how to integrate another Work problem, where F = -6x. I understood that it would integrate into -3x2 + C, and I found C. My question is how would I go about this one?
Would I start as ∫F dx = ∫ (15 kg)a dx
W = ∫ 15a dx
W = 15ax
W = 15ΔaΔx ... I'm guessing this is what I should do...
W = 15(24)(80) = 2400 J
But apparently that's wrong.
I would be soooooo thankful for anyone to help me with the integration process from here.
***************************************************************
And just in case anybody tells me to ask my teacher for help, I asked both my Physics C teacher AND my calc teacher, but both refused.
2. Oct 1, 2012
Saitama
There is no picture in your post.
3. Oct 2, 2012
4. Oct 2, 2012
nasu
You don't need to know integration techniques. It is enough to understand that the value of the (definite) integral of a function represents the area under the graph of the function.
Here is a lot more straightforward to calculate the area (as all the segments are straight lines).
5. Oct 2, 2012
majormaaz
oh, wow. I'm an idiot.
I made a typo in typing the url of the picture
here's the correct one:
http://www.webassign.net/hrw/07_34.gif
perhaps I should start using Ctrl C more often...
6. Oct 2, 2012
majormaaz
I mean, it seems rudimentary that the net work is the area under the curve times mass, since
the area under the curve is aΔx, and multiplying by m gives you maΔx, which equals work.
And yet, that was wrong.
7. Oct 2, 2012
nasu
So did you get the right answer with the new figure or not? I don't understand.
8. Oct 2, 2012
majormaaz
ahh.... I just viewed the answer key. It has 1200 J, while I kept getting 2400 J.
I think I just forgot to throw the 1/2 in there. Damn. A point lost.
But thanks for helping anyways! | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8822183609008789, "perplexity": 1121.689465091603}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-30/segments/1531676589757.30/warc/CC-MAIN-20180717164437-20180717184437-00127.warc.gz"} |
https://eepower.com/news/department-of-energy-launches-84-million-geothermal-program/ | News
# Department of Energy Launches $84 Million Geothermal Program April 20, 2022 by Ian Hahn ## The DOE issued a request for information (RFI) from relevant geothermal stakeholders, seeking guidance in its future selection of four enhanced geothermal system pilot projects. Geothermal energy has stalled in the United States. Though the country remains as of 2019 the world’s top producer of geothermal power, growth in new deployment has been stagnant for a decade. In 2012, geothermal plants produced 15,562 gigawatt hours (GWh) of electricity. That’s just four percent lower than the total in 2021, which at 16,238 GWh constituted less than half of one percent of the U.S. energy mix. ##### Geothermal power has stalled in the U.S. Image used courtesy of the DOE For the DOE, that’s a problem — the agency is targeting 60 new GW of geothermal deployment by 2050, which it says could provide non-stop power to 129 million homes and businesses. And to get there, it’s banking on serious development in enhanced geothermal system technology. ### What Are Enhanced Geothermal Systems? The DOE is planning to support four enhanced geothermal systems (EGS) pilot projects with the$84 million earmarked for geothermal development in the Bipartisan Infrastructure Law (BIL).
EGS is, in theory, the answer to the capped potential of traditional geothermal systems, which utilize reservoirs of dry steam or hot water and are severely limited by geography. The Geysers steam field in northern California, for instance, is the only viable dry steam resource in the country. Hot water reservoirs are more common, though they are far from ubiquitous, with active plants operating in just a handful of states.
But at depth in the earth’s crust, what is ubiquitous is hot rock. And an EGS is man-made.
Using a drill, developers bore into hot rock to create an injection well. Cold water is then shot down the well at sufficient pressure, fracturing the rock into a network of small fissures, which despite its lack of standing water is also referred to as a reservoir. There, the rocks’ in situ heat warms the water as it flows to a drilled production well, which then pumps it to the surface for steam production.
##### An EGS. Image [modified] used courtesy of the DOE
That is, in theory.
### Tremendous Promise, Limited Development
According to a 2006 panel report prepared for the DOE by the Idaho National Laboratory, with just modest investment EGS could provide 100 GW or more of generating capacity by 2050. That constitutes 9% of the installed capacity in the U.S. as of 2021, and 8% of projected capacity per the DOE’s release.
“The U.S. has incredible, untapped geothermal potential beneath our very feet, which can be harnessed to meet our energy demands with a round-the-clock, clean renewable resource available across the country,” said Jennifer M. Granholm, the U.S. Secretary of Energy.
But that assumes the systems are viable at scale. And after nearly 50 years of research and development across four continents, they have yet to be proven so.
Per an April 2021 report published by the Lawrence Berkeley National Lab and prepared for the DOE’s Office of Energy Efficiency and Renewable Energy (EERE), pilot projects in North America, Europe, Asia, and Australia have successfully generated electricity with EGS. But none have produced power at commercial levels, either due to insufficient circulation rates or premature thermal decline.
### Hundreds of Millions in Federal Funding for R&D
Though the DOE is under no obligation to issue, through the EERE, a funding opportunity announcement (FOA) following its RFI, the BIL’s $84 million allocation runs only through 2025. Assuming the program proceeds with grant awards before that deadline, the four pilot projects will join an expansive portfolio of federally-funded initiatives targeting EGS development. Last February, the DOE announced that its Frontier Observatory for Research in Geothermal Energy (FORGE) initiative, based at the University of Utah, had selected 17 proposals to receive up to$46 million in funding to develop new EGS projects. In 2018, the DOE awarded the University itself $140 million to establish its underground EGS laboratory in Beaver County, the first of its kind. ##### The FORGE site in Beaver County. Image used courtesy of the University of Utah Other projects from the DOE include the$27 million EGS Collab, a $20 million investment to reduce the cost of geothermal drilling, and a$3.5 million funding opportunity for projects developing machine learning to enhance EGS exploration and production.
Still, until these and the announced pilot projects prove viable at the commercial level, EGS will remain untapped.
To participate in this latest RFI, stakeholders looking to realize the technology must submit responses via email no later than 5 p.m. ET on May 13. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.4138154089450836, "perplexity": 4601.189556958623}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-21/segments/1652663039492.94/warc/CC-MAIN-20220529041832-20220529071832-00471.warc.gz"} |
http://mathhelpforum.com/calculus/198759-physics-problem-done-strictly-calculus.html | Thread: Physics Problem Done Strictly With Calculus
1. Physics Problem Done Strictly With Calculus
The problem is, "A stone is thrown upward with an initial velocity of 128 ft/s from the roof of a building 320 ft high. Express its height above the ground as a function of time. Find the following: a) The maximum height that the stone reaches b) The time it takes for the stone to reach the ground c) The velocity and speed of the stone when it hits the ground."
I am currently having trouble with problem b. My position equation I found to be $s(t) = -16t^2 + 128t + 320$.
From there, I set the position equal to zero, and then had to use the quadratic equation. The answer to b is 10 s, but I got 5 s and, I believe, -1.15 s. What did I do wrong?
2. Re: Physics Problem Done Strictly With Calculus
You don't show your working so it's not possible to say what you did wrong. I solved the quadratic and got t = 10, (and -2).
3. Re: Physics Problem Done Strictly With Calculus
I figured it out, thanks. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 1, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9333314299583435, "perplexity": 395.21504492152474}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-09/segments/1518891813187.88/warc/CC-MAIN-20180221004620-20180221024620-00669.warc.gz"} |
https://dealii.org/developer/doxygen/deal.II/code_gallery_Distributed_LDG_Method.html | Reference documentation for deal.II version Git 6dcd437 2017-07-22 22:48:07 +0200
The 'Distributed LDG Method' code gallery program
This program was contributed by Michael Harmon <mdh266@gmail.com>.
It comes without any warranty or support by its authors or the authors of deal.II.
This program is part of the deal.II code gallery and consists of the following files (click to inspect):
# Distributed Local Discontinuous Galerkin Methods
## Introduction
This code is designed to numerically solve the Poisson equation
\begin{align} - \nabla \cdot \left(\ \nabla u \ \right)&= f(\textbf{x}) && \mbox{in} \ \Omega,\nonumber \\ -\nabla u \cdot \textbf{n} &= g_{N}(\textbf{x}) && \mbox{on} \ \partial \Omega_{N} \nonumber\\ u &= g_{D}(\textbf{x}) && \mbox{on} \ \partial \Omega_{D}. \nonumber \end{align}
in 2D and 3D using the local discontinuous Galerkin (LDG) method from scratch. The tutorial codes step-12 and step-39 use the MeshWorker interface to build discontinuous Galerkin (DG) methods. While this is very convenient, I could not use this framework for solving my research problem and I needed write the LDG method from scratch. I thought it would be helpful for others to have access to this example that goes through writing a discontinuous Galerkin method from scatch and also shows how to do it in a distributed setting using the Trilinos library. This example may also be of interest to users that wish to use the LDG method, as the method is distinctly different from the Interior Penalty Discontinuous Galerkin (IPDG) methods and was not covered in other tutorials on DG methods. The LDG method is very useful when one is working with a differential equation and desires both approximations to the scalar unknown function as well as its flux. The application of a mixed method offers a mechanism whereby one can obtain both the scalar unknown function as well as its flux, however, the LDG method has less degrees of freedom compared to the mixed method with the Raviart-Thomas element. It also approximates the scalar unknown function and its flux using discontinuous polynomial basis functions and are much more suitable when one wishes to use local refinement.
## Compiling and Running
To generate a makefile for this code using CMake, type the following command into the terminal from the main directory:
cmake . -DDEAL_II_DIR=/path/to/deal.II
To compile the code in debug mode use:
make
To compile the code in release mode use:
make release
Either of these commands will create the executable, main, however the release mode will make a faster executable.
To run the code on N processors type the following command into the terminal from the main directory,
mpirun -np N ./main
The output of the code will be in .vtu and .pvtu format and be written to disk in parallel. The results can be viewed using ParaView.
## Local Discontinuous Galerkin Method
In this section we discuss the LDG method and first introduce some notation. Let $$\mathcal{T}_{h} = \mathcal{T}_{h}(\Omega) \, = \, \left\{ \, \Omega_{e} \, \right\}_{e=1}^{N}$$ be the general triangulation of a domain $$\Omega \; \subset \; \mathbb{R}^{d}, \; d \, = \, 1, 2, 3$$, into $$N$$ non-overlapping elements $$\Omega_{e}$$ of diameter $$h_{e}$$. The maximum size of the diameters of all elements is $$h = \max( \, h_{e}\, )$$. We define $$\mathcal{E}_{h}$$ to be the set of all element faces and $$\mathcal{E}_{h}^{i}$$ to be the set of all interior faces of elements which do not intersect the total boundary $$(\partial \Omega)$$. We define $$\mathcal{E}_{D}$$ and $$\mathcal{E}_{N}$$ to be the sets of all element faces and on the Dirichlet and Neumann boundaries respectively. Let $$\partial \Omega_{e} \in \mathcal{E}_{h}^{i}$$ be a interior boundary face element, we define the unit normal vector to be,
\begin{align} \textbf{n} \; = \; \text{unit normal vector to } \partial \Omega_{e} \text{ pointing from } \Omega_{e}^{-} \, \rightarrow \, \Omega_{e}^{+}. \end{align}
We take the following definition on limits of functions on element faces,
\begin{align} w^{-} (\textbf{x} ) \, \vert_{\partial \Omega_{e} } \; = \; \lim_{s \rightarrow 0^{-}} \, w(\textbf{x} + s \textbf{n}), && w^{+} (\textbf{x} ) \, \vert_{\partial \Omega_{e} } \; = \; \lim_{s \rightarrow 0^{+}} \, w(\textbf{x} + s \textbf{n}). \end{align}
We define the average and jump of a function across an element face as,
\begin{align} \{f\} \; = \; \frac{1}{2}(f^-+f^+), \qquad \mbox{and} \qquad \left[ f \right] \; = \; f^+ \textbf{n}^+ + f^- \textbf{n}^-, \end{align}
and,
\begin{align} \{\textbf{f} \} \; = \; \frac{1}{2}(\textbf{f}^- + \textbf{f}^+), \qquad \mbox{and}\qquad \left[ \textbf{f} \right] \; = \;\textbf{f}^+ \cdot \textbf{n}^+ + \textbf{f}^- \cdot \textbf{n}^- , \end{align}
where $$f$$ is a scalar function and $$\textbf{f}$$ is vector-valued function. We note that for faces that are on the boundary of the domain we have,
\begin{align} \left[ f \right] \; = \; f \, \textbf{n} \qquad \mbox{and}\qquad \left[ \textbf{f} \right] \; = \; \textbf{f} \cdot \textbf{n}. \end{align}
We denote the volume integrals and surface integrals using the $$L^{2}(\Omega)$$ inner products by $$( \, \cdot \, , \, \cdot \, )_{\Omega}$$ and $$\langle \, \cdot \, , \, \cdot \, \rangle_{\partial \Omega}$$ respectively.
As with the mixed finite element method with the Raviart-Thomas element, the LDG discretization requires the Poisson equations be written as a first-order system. We do this by introducing an auxiliary variable which we call the current flux variable $$\textbf{q}$$:
\begin{align} \nabla \cdot \textbf{q} \; &= \; f(\textbf{x}) && \text{in} \ \Omega, \label{eq:Primary} \\ \textbf{q} \; &= \; -\nabla u && \text{in} \ \Omega, \label{eq:Auxillary} \\ \textbf{q} \cdot \textbf{n} \; &= \; g_{N}(\textbf{x}) && \text{on} \ \partial \Omega_{N},\\ u &= g_{D}(\textbf{x}) && \mbox{on}\ \partial \Omega_{D}. \end{align}
In our numerical methods we will use approximations to scalar valued functions that reside in the finite-dimensional broken Sobolev spaces,
\begin{align} W_{h,k} \, &= \, \left\{ w \in L^{2}(\Omega) \, : \; w \vert_{\Omega_{e}} \in \mathcal{Q}_{k,k}(\Omega_{e}), \quad \forall \, \Omega_{e} \in \mathcal{T}_{h} \right\}, \end{align}
where $$\mathcal{Q}_{k,k}(\Omega_{e})$$ denotes the tensor product of discontinuous polynomials of order $$k$$ on the element $$\Omega_{e}$$. We use approximations of vector valued functions that are in,
\begin{align} \textbf{W}_{h,k} \, &= \, \left\{ \textbf{w} \in \left(L^{2}(\Omega)\right)^{d} \, : \; \textbf{w} \vert_{\Omega_{e}} \in \left( \mathcal{Q}_{k,k}(\Omega_{e}) \right)^{d}, \quad \forall \, \Omega_{e} \in \mathcal{T}_{h} \right\} \end{align}
We seek approximations for densities $$u_{h} \in W_{h,k}$$ and gradients $$\textbf{q}_{h}\in \textbf{W}_{h,k}$$. Multiplying (6) by $$w \in W_{h,k}$$ and (7) by $$\textbf{w} \in \textbf{W}_{h,k}$$ and integrating the divergence terms by parts over an element $$\Omega_{e} \in \mathcal{T}_{h}$$ we obtain,
\begin{align} - \left( \nabla w \, , \, \textbf{q}_{h} \right)_{\Omega_{e}} + \langle w \, , \, \textbf{q}_{h} \rangle_{\partial \Omega_{e}} \ &= \ \left( w , \, f \right)_{\Omega_{e}} , \\ \left( \textbf{w} \, , \, \textbf{q}_{h} \right)_{\Omega_{e}} - \left( \nabla \cdot \textbf{w} \, , \, u_{h} \right)_{\Omega_{e}} + \langle \textbf{w} \, , \, u_{h} \rangle_{\partial \Omega_{e}} \ &= \ 0 \end{align}
Summing over all the elements leads to the weak formulation:
Find $$u_{h} \in W_{h,k}$$ and $$\textbf{q}_{h} \in \textbf{W}_{h,k}$$ such that,
\begin{align} - \sum_{e} \left( \nabla w, \, \textbf{q}_{h} \right)_{\Omega_{e}} + \langle \left[ \, w \, \right] \, , \, \widehat{\textbf{q}_{h} } \rangle_{\mathcal{E}_{h}^{i} } + \langle \left[ \, w \, \right] \, , \, \widehat{\textbf{q}_{h} } \rangle_{\mathcal{E}_{D} \cup \mathcal{E}_{N}} \ &= \ \sum_{e} \left( w , \, f \right)_{\Omega_{e}} \\ \sum_{e} \left( \textbf{w} \, , \, \textbf{q}_{h} \right)_{\Omega_{e}} - \sum_{e} \left( \nabla \cdot \textbf{w} , \, u_{h} \right)_{\Omega_{e}} + \langle \, \left[ \, \textbf{w} \, \right] \, , \, \widehat{u_{h}} \rangle_{\mathcal{E}_{h}^{i}} + \langle \left[ \, \textbf{w} \, \right] \, , \, \widehat{u_{h}} \rangle_{\mathcal{E}_{D} \cup \mathcal{E}_{N}} \ &= \ 0 \end{align}
for all $$(w,\textbf{w}) \in W_{h,k} \times \textbf{W}_{h,k}$$.
The terms $$\widehat{\textbf{q}_{h}}$$ and $$\widehat{u_{h}}$$ are the numerical fluxes. The numerical fluxes are introduced to ensure consistency, stability, and enforce the boundary conditions weakly, for more info see the book: Nodal Discontinuous Galerkin Methods. The flux $$\widehat{u_{h}}$$ is,
\begin{align} \widehat{u_{h}} \; = \; \left\{ \begin{array}{cl} \left\{ u_{h} \right\} \ + \ \boldsymbol \beta \cdot [ u_{h} ] \, & \ \text{in} \ \mathcal{E}_{h}^{i} \\ u_{h} & \ \text{in} \ \mathcal{E}_{N}\\ g_{D}(\textbf{x}) & \ \text{in} \ \mathcal{E}_{D} \\ \end{array} \right. \end{align}
The flux $$\widehat{\textbf{q}_{h}}$$ is,
\begin{align} \widehat{\textbf{q}_{h}} \; = \; \left\{ \begin{array}{cl} \left\{ \textbf{q}_{h} \right\} \ - \ \left[ \textbf{q}_{h} \right] \, \boldsymbol \beta \ + \ \sigma \, \left[ \, u_{h} \, \right] & \ \text{in} \ \mathcal{E}_{h}^{i} \\ g_{N}(\textbf{x}) \, \textbf{n} \, & \ \text{in} \ \mathcal{E}_{N}\\ \textbf{q}_{h} \ + \ \sigma \, \left(u_{h} - g_{D}(\textbf{x}) \right) \, \textbf{n} & \ \text{in} \ \mathcal{E}_{D} \\ \end{array} \right. \end{align}
The term $$\boldsymbol \beta$$ is a constant unit vector which does not lie parallel to any element face in $$\mathcal{E}_{h}^{i}$$. For $$\boldsymbol \beta = 0$$, $$\widehat{\textbf{q}_{h}}$$ and $$\widehat{u_{h}}$$ are called the central or Brezzi et. al. fluxes. For $$\boldsymbol \beta \neq 0$$, $$\widehat{\textbf{q}_{h}}$$ and $$\widehat{u_{h}}$$ are called the LDG/alternating fluxes, see here and here.
The term $$\sigma$$ is the penalty parameter that is defined as,
\begin{align} \sigma \; = \; \left\{ \begin{array}{cc} \tilde{\sigma} \, \min \left( h^{-1}_{e_{1}}, h^{-1}_{e_{2}} \right) & \textbf{x} \in \langle \Omega_{e_{1}}, \Omega_{e_{2}} \rangle \\ \tilde{\sigma} \, h^{-1}_{e} & \textbf{x} \in \partial \Omega_{e} \cap \in \mathcal{E}_{D} \end{array} \right. \label{eq:Penalty} \end{align}
with $$\tilde{\sigma}$$ being a positive constant. There are other choices of penalty values $$\sigma$$, but the one above produces in appoximations to solutions that are the most accurate, see this reference for more info.
We can now substitute (16) and (17) into (14) and (15) to obtain the solution pair $$(u_{h}, \textbf{q}_{h})$$ to the LDG approximation to the Poisson equation given by:
Find $$u_{h} \in W_{h,k}$$ and $$\textbf{q}_{h} \in \textbf{W}_{h,k}$$ such that,
\begin{align} a(\textbf{w}, \textbf{q}_{h}) \ + \ b^{T}(\textbf{w}, u_{h}) \ &= \ G(\textbf{w}) \nonumber \\ b(w, \textbf{q}_{h}) \ + \ c(w, u_{h}) \ &= \ F(w) \label{eq:LDG_bilinear} \end{align}
for all $$(w, \textbf{w}) \in W_{h,k} \times \textbf{W}_{h,k}$$. This leads to the linear system,
\begin{align} \left[ \begin{matrix} A & -B^{T} \\ B & C \end{matrix} \right] \left[ \begin{matrix} \textbf{Q}\\ \textbf{U} \end{matrix} \right] \ = \ \left[ \begin{matrix} \textbf{G}\\ \textbf{F} \end{matrix} \right] \end{align}
Where $$\textbf{U}$$ and $$\textbf{Q}$$ are the degrees of freedom vectors for $$u_{h}$$ and $$\textbf{q}_{h}$$ respectively. The terms $$\textbf{G}$$ and $$\textbf{F}$$ are the corresponding vectors to $$G(\textbf{w})$$ and $$F(w)$$ respectively. The matrix in for the LDG system is non-singular for any $$\sigma > 0$$.
The bilinear forms in (19) and right hand functions are defined as,
\begin{align} b(w, \textbf{q}_{h}) \, &= \, - \sum_{e} \left(\nabla w, \textbf{q}_{h} \right)_{\Omega_{e}} + \langle \left[ w \right], \left\{\textbf{q}_{h} \right\} - \left[ \textbf{q}_{h} \right] \boldsymbol \beta \rangle_{\mathcal{E}_{h}^{i}} + \langle w, \textbf{n} \cdot \textbf{q}_{h} \rangle_{\mathcal{E}_{D}}\\ a(\textbf{w},\textbf{q}_{h}) \, &= \, \sum_{e} \left(\textbf{w}, \textbf{q}_{h} \right)_{\Omega_{e}} \\ -b^{T}(w, \textbf{q}_{h}) \, &= \, - \sum_{e} \left(\nabla \cdot \textbf{w}, u_{h} \right)_{\Omega_{e}} + \langle \left[ \textbf{w} \right], \left\{u_{h} \right\} + \boldsymbol \beta \cdot \left[ u_{h} \right] \rangle_{\mathcal{E}_h^{i} } + \langle w, u_{h} \rangle_{\mathcal{E}_{N} } \\ c(w,u_{h}) \, &= \, \langle \left[ w \right], \sigma \left[ u_{h} \right] \rangle_{\mathcal{E}_{h}^{i}} + \langle w, \sigma u_{h} \rangle_{\mathcal{E}_{D}} \\ G(\textbf{w}) \ & = \ - \langle \textbf{w}, g_{D} \rangle_{\mathcal{E}_{D}}\\ F(w) \ & = \ \sum_{e} (w,f)_{\Omega_{e}} - \langle w, g_{N} \rangle_{\mathcal{E}_{N}} + \langle w, \sigma g_{D} \rangle_{\mathcal{E}_{D}} \end{align}
As discussed in step-20, we won't be assembling the bilinear terms explicitly, instead we will assemble all the solid integrals and fluxes at once. We note that in order to actually build the flux terms in our local flux matrices we will substitute in the definitions in the bilinear terms above.
## Useful References
These are some useful references on the LDG and DG methods:
# Annotated version of Functions.cc
### Functions.cc
In this file we keep right hand side function, Dirichlet boundary conditions and solution to our Poisson equation problem. Since these classes and functions have been discussed extensively in the deal.ii tutorials we won't discuss them any further.
#include <deal.II/base/function.h>
#include <deal.II/base/tensor_function.h>
#include <deal.II/lac/vector.h>
#include <cmath>
using namespace dealii;
template <int dim>
class RightHandSide : public Function<dim>
{
public:
RightHandSide() : Function<dim>(1)
{}
virtual double value(const Point<dim> &p,
const unsigned int component = 0 ) const;
};
template <int dim>
class DirichletBoundaryValues : public Function<dim>
{
public:
DirichletBoundaryValues() : Function<dim>(1)
{}
virtual double value(const Point<dim> &p,
const unsigned int component = 0 ) const;
};
template<int dim>
class TrueSolution : public Function<dim>
{
public:
TrueSolution() : Function<dim>(dim+1)
{}
virtual void vector_value(const Point<dim> & p,
Vector<double> &valuess) const;
};
template <int dim>
double
RightHandSide<dim>::
value(const Point<dim> &p,
const unsigned int ) const
{
const double x = p[0];
const double y = p[1];
return 4*M_PI*M_PI*(cos(2*M_PI*y) - sin(2*M_PI*x));
}
template <int dim>
double
DirichletBoundaryValues<dim>::
value(const Point<dim> &p,
const unsigned int ) const
{
const double x = p[0];
const double y = p[1];
return cos(2*M_PI*y) -sin(2*M_PI*x) - x;
}
template <int dim>
void
TrueSolution<dim>::
vector_value(const Point<dim> &p,
Vector<double> &values) const
{
Assert(values.size() == dim+1,
ExcDimensionMismatch(values.size(), dim+1) );
double x = p[0];
double y = p[1];
values(0) = 1 + 2*M_PI*cos(2*M_PI*x);
values(1) = 2*M_PI*sin(2*M_PI*y);
values(2) = cos(2*M_PI*y) - sin(2*M_PI*x) - x;
}
# Annotated version of LDGPoisson.cc
### LDGPoisson.cc
The code begins as per usual with a long list of the the included files from the deal.ii library.
#include <deal.II/base/logstream.h>
#include <deal.II/base/function.h>
#include <deal.II/base/timer.h>
#include <deal.II/lac/full_matrix.h>
#include <deal.II/lac/sparse_matrix.h>
#include <deal.II/grid/tria.h>
#include <deal.II/grid/grid_generator.h>
#include <deal.II/grid/grid_tools.h>
#include <deal.II/grid/tria_accessor.h>
#include <deal.II/grid/tria_iterator.h>
#include <deal.II/dofs/dof_handler.h>
#include <deal.II/dofs/dof_renumbering.h>
#include <deal.II/dofs/dof_accessor.h>
#include <deal.II/dofs/dof_tools.h>
#include <fstream>
#include <iostream>
Here's where the classes for the DG methods begin. We can use either the Lagrange polynomials,
#include <deal.II/fe/fe_dgq.h>
or the Legendre polynomials
#include <deal.II/fe/fe_dgp.h>
as basis functions. I'll be using the Lagrange polynomials.
#include <deal.II/fe/fe_system.h>
#include <deal.II/fe/fe_values.h>
#include <deal.II/numerics/vector_tools.h>
#include <deal.II/numerics/matrix_tools.h>
#include <deal.II/numerics/data_out.h>
Now we have to load in the deal.ii files that will allow us to use a distributed computing framework.
#include <deal.II/base/utilities.h>
#include <deal.II/base/index_set.h>
#include <deal.II/base/conditional_ostream.h>
#include <deal.II/lac/sparsity_tools.h>
#include <deal.II/distributed/tria.h>
Additionally we load the files that will allow us to interact with the Trilinos library.
#include <deal.II/lac/trilinos_sparse_matrix.h>
#include <deal.II/lac/trilinos_vector.h>
#include <deal.II/lac/trilinos_solver.h>
The functions class contains all the defintions of the functions we will use, i.e. the right hand side function, the boundary conditions and the test functions.
#include "Functions.cc"
using namespace dealii;
Here is the main class for the Local Discontinuous Galerkin method applied to Poisson's equation, we won't explain much of the the class and method declarations, but dive deeper into describing the functions when they are defined. The only thing I will menion about the class declaration is that this is where I labeled the different types of boundaries using enums.
template <int dim>
class LDGPoissonProblem
{
public:
LDGPoissonProblem(const unsigned int degree,
const unsigned int n_refine);
~LDGPoissonProblem();
void run();
private:
void make_grid();
void make_dofs();
void assemble_system();
void assemble_cell_terms(const FEValues<dim> &cell_fe,
FullMatrix<double> &cell_matrix,
Vector<double> &cell_vector);
void assemble_Neumann_boundary_terms(const FEFaceValues<dim> &face_fe,
FullMatrix<double> &local_matrix,
Vector<double> &local_vector);
void assemble_Dirichlet_boundary_terms(const FEFaceValues<dim> &face_fe,
FullMatrix<double> &local_matrix,
Vector<double> &local_vector,
const double & h);
void assemble_flux_terms(const FEFaceValuesBase<dim> &fe_face_values,
const FEFaceValuesBase<dim> &fe_neighbor_face_values,
FullMatrix<double> &vi_ui_matrix,
FullMatrix<double> &vi_ue_matrix,
FullMatrix<double> &ve_ui_matrix,
FullMatrix<double> &ve_ue_matrix,
const double & h);
void distribute_local_flux_to_global(
const FullMatrix<double> & vi_ui_matrix,
const FullMatrix<double> & vi_ue_matrix,
const FullMatrix<double> & ve_ui_matrix,
const FullMatrix<double> & ve_ue_matrix,
const std::vector<types::global_dof_index> & local_dof_indices,
const std::vector<types::global_dof_index> & local_neighbor_dof_indices);
void solve();
void output_results() const;
const unsigned int degree;
const unsigned int n_refine;
double penalty;
double h_max;
double h_min;
enum
{
Dirichlet,
Neumann
};
DoFHandler<dim> dof_handler;
ConstraintMatrix constraints;
SparsityPattern sparsity_pattern;
TrilinosWrappers::SparseMatrix system_matrix;
TrilinosWrappers::MPI::Vector locally_relevant_solution;
TimerOutput computing_timer;
SolverControl solver_control;
const RightHandSide<dim> rhs_function;
const DirichletBoundaryValues<dim> Dirichlet_bc_function;
const TrueSolution<dim> true_solution;
};
#### Class constructor and destructor
The constructor and destructor for this class is very much like the like those for step-40. The difference being that we'll be passing in an integer, degree, which tells us the maxiumum order of the polynomial to use as well as n_refine which is the global number of times we refine our mesh. The other main differences are that we use a FESystem object for our choice of basis functions. This is reminiscent of the mixed finite element method in step-20, however, in our case we use a FESystem of the form,
fe( FESystem<dim>(FE_DGQ<dim>(degree), dim), 1, FE_DGQ<dim>(degree), 1)
which tells us that the basis functions contain discontinous polynomials of order degree in each of the dim dimensions for the vector field. For the scalar unknown we use a discontinuous polynomial of the order degree. The LDG method for Poisson equations solves for both the primary variable as well as its gradient, just like the mixed finite element method. However, unlike the mixed method, the LDG method uses discontinuous polynomials to approximate both variables. The other difference bewteen our constructor and that of step-40 is that we all instantiate our linear solver in the constructor definition.
template <int dim>
LDGPoissonProblem<dim>::
LDGPoissonProblem(const unsigned int degree,
const unsigned int n_refine)
:
degree(degree),
n_refine(n_refine),
triangulation(MPI_COMM_WORLD,
typename Triangulation<dim>::MeshSmoothing
(Triangulation<dim>::smoothing_on_refinement |
Triangulation<dim>::smoothing_on_coarsening)),
fe( FESystem<dim>(FE_DGQ<dim>(degree), dim), 1,
FE_DGQ<dim>(degree), 1),
dof_handler(triangulation),
pcout(std::cout,
Utilities::MPI::this_mpi_process(MPI_COMM_WORLD) == 0),
computing_timer(MPI_COMM_WORLD,
pcout,
TimerOutput::summary,
TimerOutput::wall_times),
solver_control(1),
solver(solver_control),
rhs_function(),
Dirichlet_bc_function()
{
}
template <int dim>
LDGPoissonProblem<dim>::
~LDGPoissonProblem()
{
dof_handler.clear();
}
#### Make_grid
This function shows how to make a grid using local refinement and also shows how to label the boundaries using the defined enum.
template <int dim>
void
LDGPoissonProblem<dim>::
make_grid()
{
GridGenerator::hyper_cube(triangulation, 0, 1);
triangulation.refine_global(n_refine);
unsigned int local_refine = 2;
for(unsigned int i =0; i <local_refine; i++)
{
cell = triangulation.begin_active(),
endc = triangulation.end();
We loop over all the cells in the mesh and mark the appropriate cells for refinement. In this example we only choose cells which are near $$x=0$$ and $$x=1$$ in the the domain. This was just to show that the LDG method is working with local refinement and discussions on building more realistic refinement stategies are discussed elsewhere in the deal.ii documentation.
for(; cell != endc; cell++)
{
if((cell->center()[1]) > 0.9 )
{
if((cell->center()[0] > 0.9) || (cell->center()[0] < 0.1))
cell->set_refine_flag();
}
}
Now that we have marked all the cells that we want to refine locally we can go ahead and refine them.
To label the boundary faces of the mesh with their type, i.e. Dirichlet or Neumann, we loop over all the cells in the mesh and then over all the faces of each cell. We then have to figure out which faces are on the bounadry and set all faces on the boundary to have boundary_id to be Dirichlet. We remark that one could easily set more complicated conditions where there are both Dirichlet or Neumann boundaries.
cell = triangulation.begin(),
endc = triangulation.end();
for(; cell != endc; cell++)
{
for(unsigned int face_no=0;
face_no < GeometryInfo<dim>::faces_per_cell;
face_no++)
{
if(cell->face(face_no)->at_boundary() )
cell->face(face_no)->set_boundary_id(Dirichlet);
}
}
}
### make_dofs
This function is responsible for distributing the degrees of freedom (dofs) to the processors and allocating memory for the global system matrix, system_matrix, and global right hand side vector, system_rhs . The dofs are the unknown coefficients for the polynomial approximation of our solution to Poisson's equation in the scalar variable and its gradient.
template <int dim>
void
LDGPoissonProblem<dim>::
make_dofs()
{
TimerOutput::Scope t(computing_timer, "setup");
The first step to setting up our linear system is to distribute the degrees of freedom (dofs) across the processors, this is done with the distribute_dofs() method of the DoFHandler. We remark the same exact function call that occurs when using deal.ii on a single machine, the DoFHandler automatically knows that we are distributed setting because it was instantiated with a distributed triangulation!
dof_handler.distribute_dofs(fe);
We now renumber the dofs so that the vector of unkonwn dofs that we are solving for, locally_relevant_solution, corresponds to a vector of the form,
$$\left[\begin{matrix} \textbf{Q} \\ \textbf{U} \end{matrix}\right]$$
Now we get the locally owned dofs, that is the dofs that our local to this processor. These dofs corresponding entries in the matrix and vectors that we will write to.
IndexSet locally_owned_dofs = dof_handler.locally_owned_dofs();
In additon to the locally owned dofs, we also need the the locally relevant dofs. These are the dofs that have read access to and we need in order to do computations on our processor, but, that we do not have the ability to write to.
IndexSet locally_relevant_dofs;
locally_relevant_dofs);
std::vector<types::global_dof_index> dofs_per_component(dim+1);
DoFTools::count_dofs_per_component(dof_handler, dofs_per_component);
Discontinuous Galerkin methods are fantanistic methods in part because many of the limitations of traditional finite element methods no longer exist. Specifically, the need to use constraint matrices in order handle hanging nodes is no longer necessary. However, we will continue to use the constraint matrices inorder to efficiently distribute local computations to the global system, i.e. to the system_matrix and system_rhs. Therefore, we just instantiate the constraints matrix object, clear and close it.
constraints.clear();
constraints.close();
Just like step-40 we create a dynamic sparsity pattern and distribute it to the processors. Notice how we do not have to explictly mention that we are using a FESystem for system of variables instead of a FE_DGQ for a scalar variable or that we are using a discributed DoFHandler. All these specifics are taken care of under the hood by the deal.ii library. In order to build the sparsity pattern we use the DoFTools::make_flux_sparsity_pattern function since we using a DG method and need to take into account the DG fluxes in the sparsity pattern.
DynamicSparsityPattern dsp(dof_handler.n_dofs());
dsp);
MPI_COMM_WORLD,
locally_relevant_dofs);
Here is one area that I had to learn the hard way. The local discontinuous Galerkin method like the mixed method with the Raviart-Thomas element is written in mixed form and will lead to a block-structured matrix. In step-20 we see that we that we initialize the system_martrix such that we explicitly declare it to be block-structured. It turns out there are reasons to do this when you are going to be using a Schur complement method to solve the system of equations. While the LDG method will lead to a block-structured matrix, we do not have to explicitly declare our matrix to be one. I found that most of the distributed linear solvers did not accept block structured matrices and since I was using a distributed direct solver it was unnecessary to explicitly use a block structured matrix.
system_matrix.reinit(locally_owned_dofs,
locally_owned_dofs,
dsp,
MPI_COMM_WORLD);
The final note that I will make in that this subroutine is that we initialize this processors solution and the right hand side vector the exact same was as we did in step-40. We should note that the locally_relevant_solution solution vector includes dofs that are locally relevant to our computations while the system_rhs right hand side vector will only include dofs that are locally owned by this processor.
locally_relevant_solution.reinit(locally_relevant_dofs,
MPI_COMM_WORLD);
system_rhs.reinit(locally_owned_dofs,
locally_relevant_dofs,
MPI_COMM_WORLD,
true);
const unsigned int n_vector_field = dim * dofs_per_component[0];
const unsigned int n_potential = dofs_per_component[dim];
pcout << "Number of active cells : "
<< triangulation.n_global_active_cells()
<< std::endl
<< "Number of degrees of freedom: "
<< dof_handler.n_dofs()
<< " (" << n_vector_field << " + " << n_potential << ")"
<< std::endl;
}
#### assemble_system
This is the function that will assemble the global system matrix and global right hand side vector for the LDG method. It starts out like many of the deal.ii tutorial codes: declaring quadrature formulas and UpdateFlags objects, as well as vectors that will hold the dof indices for the cells we are working on in the global system.
template <int dim>
void
LDGPoissonProblem<dim>::
assemble_system()
{
TimerOutput::Scope t(computing_timer, "assembly");
const UpdateFlags update_flags = update_values
const UpdateFlags face_update_flags = update_values
const unsigned int dofs_per_cell = fe.dofs_per_cell;
std::vector<types::global_dof_index> local_dof_indices(dofs_per_cell);
std::vector<types::global_dof_index>
local_neighbor_dof_indices(dofs_per_cell);
We first remark that we have the FEValues objects for the values of our cell basis functions as was done in most other examples. Now because we are using discontinuous Galerkin methods we also introduce a FEFaceValues object, fe_face_values, for evaluating the basis functions on one side of an element face as well as another FEFaceValues object, fe_neighbor_face_values, for evaluating the basis functions on the opposite side of the face, i.e. on the neighoring element's face. In addition, we also introduce a FESubfaceValues object, fe_subface_values, that will be used for dealing with faces that have multiple refinement levels, i.e. hanging nodes. When we have to evaluate the fluxes across a face that multiple refinement levels, we need to evaluate the fluxes across all its childrens' faces; we'll explain this more when the time comes.
face_update_flags);
FEFaceValues<dim> fe_neighbor_face_values(fe,
face_update_flags);
face_update_flags);
Here are the local (dense) matrix and right hand side vector for the solid integrals as well as the integrals on the boundaries in the local discontinuous Galerkin method. These terms will be built for each local element in the mesh and then distributed to the global system matrix and right hand side vector.
FullMatrix<double> local_matrix(dofs_per_cell,dofs_per_cell);
Vector<double> local_vector(dofs_per_cell);
The next four matrices are used to incorporate the flux integrals across interior faces of the mesh:
FullMatrix<double> vi_ui_matrix(dofs_per_cell, dofs_per_cell);
FullMatrix<double> vi_ue_matrix(dofs_per_cell, dofs_per_cell);
FullMatrix<double> ve_ui_matrix(dofs_per_cell, dofs_per_cell);
FullMatrix<double> ve_ue_matrix(dofs_per_cell, dofs_per_cell);
As explained in the section on the LDG method we take our test function to be v and multiply it on the left side of our differential equation that is on u and peform integration by parts as explained in the introduction. Using this notation for test and solution function, the matrices below will then stand for:
vi_ui - Taking the value of the test function from interior of this cell's face and the solution function from the interior of this cell.
vi_ue - Taking the value of the test function from interior of this cell's face and the solution function from the exterior of this cell.
ve_ui - Taking the value of the test function from exterior of this cell's face and the solution function from the interior of this cell.
ve_ue - Taking the value of the test function from exterior of this cell's face and the solution function from the exterior of this cell.
Now that we have gotten preliminary orders out of the way, we loop over all the cells and assemble the local system matrix and local right hand side vector using the DoFHandler::active_cell_iterator,
cell = dof_handler.begin_active(),
endc = dof_handler.end();
for(; cell!=endc; cell++)
{
Now, since we are working in a distributed setting, we can only work on cells and write to dofs in the system_matrix and rhs_vector that corresponds to cells that are locally owned by this processor. We note that while we can only write to locally owned dofs, we will still use information from cells that are locally relevant. This is very much the same as in step-40.
if(cell->is_locally_owned())
{
We now assemble the local contributions to the system matrix that includes the solid integrals in the LDG method as well as the right hand side vector. This involves resetting the local matrix and vector to contain all zeros, reinitializing the FEValues object for this cell and then building the local_matrix and local_rhs vector.
local_matrix = 0;
local_vector = 0;
fe_values.reinit(cell);
assemble_cell_terms(fe_values,
local_matrix,
local_vector);
We remark that we need to get the local indices for the dofs to to this cell before we begin to compute the contributions from the numerical fluxes, i.e. the boundary conditions and interior fluxes.
cell->get_dof_indices(local_dof_indices);
Now is where we start to loop over all the faces of the cell and construct the local contribtuions from the numerical fluxes. The numerical fluxes will be due to 3 contributions: the interior faces, the faces on the Neumann boundary and the faces on the Dirichlet boundary. We instantiate a face_iterator to loop over all the faces of this cell and first see if the face is on the boundary. Notice how we do not reinitiaize the fe_face_values object for the face until we know that we are actually on face that lies on the boundary of the domain. The reason for doing this is for computational efficiency; reinitializing the FEFaceValues for each face is expensive and we do not want to do it unless we are actually going use it to do computations. After this, we test if the face is on the a Dirichlet or a Neumann segment of the boundary and call the appropriate subroutine to assemble the contributions for that boundary. Note that this assembles the flux contribution in the local_matrix as well as the boundary condition that ends up in the local_vector.
for(unsigned int face_no=0;
face_no< GeometryInfo<dim>::faces_per_cell;
face_no++)
{
cell->face(face_no);
if(face->at_boundary() )
{
fe_face_values.reinit(cell, face_no);
if(face->boundary_id() == Dirichlet)
{
Here notice that in order to assemble the flux due to the penalty term for the the Dirichlet boundary condition we need the local cell diameter size and we can get that value for this specific cell with the following,
double h = cell->diameter();
assemble_Dirichlet_boundary_terms(fe_face_values,
local_matrix,
local_vector,
h);
}
else if(face->boundary_id() == Neumann)
{
assemble_Neumann_boundary_terms(fe_face_values,
local_matrix,
local_vector);
}
else
}
else
{
At this point we know that the face we are on is an interior face. We can begin to assemble the interior flux matrices, but first we want to make sure that the neighbor cell to this face is a valid cell. Once we know that the neighbor is a valid cell then we also want to get the meighbor cell that shares this cell's face.
Assert(cell->neighbor(face_no).state() ==
typename DoFHandler<dim>::cell_iterator neighbor =
cell->neighbor(face_no);
Now that we have the two cells whose face we want to compute the numerical flux across, we need to know if the face has been refined, i.e. if it has children faces. This occurs when one of the cells has a different level of refinement than the other cell. If this is the case, then this face has a different level of refinement than the other faces of the cell, i.e. on this face there is a hanging node. Hanging nodes are not a problem in DG methods, the only time we have to watch out for them is at this step and as you will see the changes we have to our make are minor.
if(face->has_children())
{
We now need to find the face of our neighbor cell such that neighbor(neigh_face_no) = cell(face_no).
const unsigned int neighbor_face_no =
cell->neighbor_of_neighbor(face_no);
Once we do this we then have to loop over all the subfaces (children faces) of our cell's face and compute the interior fluxes across the children faces and the neighbor's face.
for(unsigned int subface_no=0;
subface_no < face->number_of_children();
++subface_no)
{
We then get the neighbor cell's subface that matches our cell face's subface and the specific subface number. We assert that the parent face cannot be more than one level of refinement above the child's face. This is because the deal.ii library does not allow neighboring cells to have refinement levels that are more than one level in difference.
typename DoFHandler<dim>::cell_iterator neighbor_child =
cell->neighbor_child_on_subface(face_no,
subface_no);
Assert(!neighbor_child->has_children(),
Now that we are ready to build the local flux matrices for this face we reset them e zero and reinitialize this fe_values to this cell's subface and neighbor_child's FEFaceValues and the FESubfaceValues objects on the appropriate faces.
vi_ui_matrix = 0;
vi_ue_matrix = 0;
ve_ui_matrix = 0;
ve_ue_matrix = 0;
fe_subface_values.reinit(cell, face_no, subface_no);
fe_neighbor_face_values.reinit(neighbor_child,
neighbor_face_no);
In addition, we get the minimum of diameters of the two cells to include in the penalty term
double h = std::min(cell->diameter(),
neighbor_child->diameter());
We now finally assemble the interior fluxes for the case of a face which has been refined using exactly the same subroutine as we do when both cells have the same refinement level.
assemble_flux_terms(fe_subface_values,
fe_neighbor_face_values,
vi_ui_matrix,
vi_ue_matrix,
ve_ui_matrix,
ve_ue_matrix,
h);
Now all that is left to be done before distribuing the local flux matrices to the global system is get the neighbor child faces dof indices.
neighbor_child->get_dof_indices(local_neighbor_dof_indices);
Once we have this cells dof indices and the neighboring cell's dof indices we can use the ConstraintMatrix to distribute the local flux matrices to the global system matrix. This is done through the class function distribute_local_flux_to_global().
distribute_local_flux_to_global(
vi_ui_matrix,
vi_ue_matrix,
ve_ui_matrix,
ve_ue_matrix,
local_dof_indices,
local_neighbor_dof_indices);
}
}
else
{
At this point we know that this cell and the neighbor of this cell are on the same refinement level and the work to assemble the interior flux matrices is very much the same as before. Infact it is much simpler since we do not have to loop through the subfaces. However, we have to check that we do not compute the same contribution twice. This would happen because we are looping over all the faces of all the cells in the mesh and assembling the interior flux matrices for each face. To avoid doing assembling the interior flux matrices twice we only compute the interior fluxes once for each face by restricting that the following computation only occur on the on the cell face with the lower CellId.
if(neighbor->level() == cell->level() &&
cell->id() < neighbor->id())
{
Here we find the neighbor face such that neighbor(neigh_face_no) = cell(face_no). In addition we, reinitialize the FEFaceValues and neighbor cell's FEFaceValues on their respective cells' faces, as well as get the minimum diameter of this cell and the neighbor cell and assign it to h.
const unsigned int neighbor_face_no =
cell->neighbor_of_neighbor(face_no);
vi_ui_matrix = 0;
vi_ue_matrix = 0;
ve_ui_matrix = 0;
ve_ue_matrix = 0;
fe_face_values.reinit(cell, face_no);
fe_neighbor_face_values.reinit(neighbor,
neighbor_face_no);
double h = std::min(cell->diameter(),
neighbor->diameter());
Just as before we assemble the interior fluxes using the assemble_flux_terms subroutine, get the neighbor cell's face dof indices and use the constraint matrix to distribute the local flux matrices to the global system_matrix using the class function distribute_local_flux_to_global()
assemble_flux_terms(fe_face_values,
fe_neighbor_face_values,
vi_ui_matrix,
vi_ue_matrix,
ve_ui_matrix,
ve_ue_matrix,
h);
neighbor->get_dof_indices(local_neighbor_dof_indices);
distribute_local_flux_to_global(
vi_ui_matrix,
vi_ue_matrix,
ve_ui_matrix,
ve_ue_matrix,
local_dof_indices,
local_neighbor_dof_indices);
}
}
}
}
Now that have looped over all the faces for this cell and computed as well as disributed the local flux matrices to the system_matrix, we can finally distribute the cell's local_matrix and local_vector contribution to the global system matrix and global right hand side vector. We remark that we have to wait until this point to distribute the local_matrix and system_rhs to the global system. The reason being that in looping over the faces the faces on the boundary of the domain contribute to the local_matrix and system_rhs. We could distribute the local contributions for each component seperately, but writing to the distributed sparse matrix and vector is expensive and want to to minimize the number of times we do so.
constraints.distribute_local_to_global(local_matrix,
local_dof_indices,
system_matrix);
constraints.distribute_local_to_global(local_vector,
local_dof_indices,
system_rhs);
}
}
We need to synchronize assembly of our global system matrix and global right hand side vector with all the other processors and use the compress() function to do this. This was discussed in detail in step-40.
}
#### assemble_cell_terms
This function deals with constructing the local matrix due to the solid integrals over each element and is very similar to the the other examples in the deal.ii tutorials.
template<int dim>
void
LDGPoissonProblem<dim>::
assemble_cell_terms(
const FEValues<dim> &cell_fe,
FullMatrix<double> &cell_matrix,
Vector<double> &cell_vector)
{
const unsigned int dofs_per_cell = cell_fe.dofs_per_cell;
const unsigned int n_q_points = cell_fe.n_quadrature_points;
const FEValuesExtractors::Vector VectorField(0);
const FEValuesExtractors::Scalar Potential(dim);
std::vector<double> rhs_values(n_q_points);
We first get the value of the right hand side function evaluated at the quadrature points in the cell.
rhs_values);
Now, we loop over the quadrature points in the cell and then loop over the degrees of freedom and perform quadrature to approximate the integrals.
for(unsigned int q=0; q<n_q_points; q++)
{
for(unsigned int i=0; i<dofs_per_cell; i++)
{
const Tensor<1, dim> psi_i_field = cell_fe[VectorField].value(i,q);
const double div_psi_i_field = cell_fe[VectorField].divergence(i,q);
const double psi_i_potential = cell_fe[Potential].value(i,q);
for(unsigned int j=0; j<dofs_per_cell; j++)
{
const Tensor<1, dim> psi_j_field = cell_fe[VectorField].value(j,q);
const double psi_j_potential = cell_fe[Potential].value(j,q);
This computation corresponds to assembling the local system matrix for the integral over an element,
$$\int_{\Omega_{e}} \left(\textbf{w} \cdot \textbf{q} - \nabla \cdot \textbf{w} u - \nabla w \cdot \textbf{q} \right) dx$$
cell_matrix(i,j) += ( (psi_i_field * psi_j_field)
-
(div_psi_i_field * psi_j_potential)
-
) * cell_fe.JxW(q);
}
And this local right hand vector corresponds to the integral over the element cell,
$$\int_{\Omega_{e}} w \, f(\textbf{x}) \, dx$$
cell_vector(i) += psi_i_potential *
rhs_values[q] *
cell_fe.JxW(q);
}
}
}
#### assemble_Dirichlet_boundary_terms
Here we have the function that builds the local_matrix contribution and local right hand side vector, local_vector for the Dirichlet boundary condtions.
template<int dim>
void
LDGPoissonProblem<dim>::
assemble_Dirichlet_boundary_terms(
const FEFaceValues<dim> &face_fe,
FullMatrix<double> &local_matrix,
Vector<double> &local_vector,
const double & h)
{
const unsigned int dofs_per_cell = face_fe.dofs_per_cell;
const unsigned int n_q_points = face_fe.n_quadrature_points;
const FEValuesExtractors::Vector VectorField(0);
const FEValuesExtractors::Scalar Potential(dim);
std::vector<double> Dirichlet_bc_values(n_q_points);
In order to evaluate the flux on the Dirichlet boundary face we first get the value of the Dirichlet boundary function on the quadrature points of the face. Then we loop over all the quadrature points and degrees of freedom and approximate the integrals on the Dirichlet boundary element faces.
Dirichlet_bc_values);
for(unsigned int q=0; q<n_q_points; q++)
{
for(unsigned int i=0; i<dofs_per_cell; i++)
{
const Tensor<1, dim> psi_i_field = face_fe[VectorField].value(i,q);
const double psi_i_potential = face_fe[Potential].value(i,q);
for(unsigned int j=0; j<dofs_per_cell; j++)
{
const Tensor<1, dim> psi_j_field = face_fe[VectorField].value(j,q);
const double psi_j_potential = face_fe[Potential].value(j,q);
We compute contribution for the flux $$\widehat{q}$$ on the Dirichlet boundary which enters our system matrix as,
$$\int_{\text{face}} w \, ( \textbf{n} \cdot \textbf{q} + \sigma u) ds$$
local_matrix(i,j) += psi_i_potential * (
face_fe.normal_vector(q) *
psi_j_field
+
(penalty/h) *
psi_j_potential) *
face_fe.JxW(q);
}
We also compute the contribution for the flux for $$\widehat{u}$$ on the Dirichlet boundary which is the Dirichlet boundary condition function and enters the right hand side vector as
$$\int_{\text{face}} (-\textbf{w} \cdot \textbf{n} + \sigma w) \, u_{D} ds$$
local_vector(i) += (-1.0 * psi_i_field *
face_fe.normal_vector(q)
+
(penalty/h) *
psi_i_potential) *
Dirichlet_bc_values[q] *
face_fe.JxW(q);
}
}
}
#### assemble_Neumann_boundary_terms
Here we have the function that builds the local_matrix and local_vector for the Neumann boundary condtions.
template<int dim>
void
LDGPoissonProblem<dim>::
assemble_Neumann_boundary_terms(
const FEFaceValues<dim> &face_fe,
FullMatrix<double> &local_matrix,
Vector<double> &local_vector)
{
const unsigned int dofs_per_cell = face_fe.dofs_per_cell;
const unsigned int n_q_points = face_fe.n_quadrature_points;
const FEValuesExtractors::Vector VectorField(0);
const FEValuesExtractors::Scalar Potential(dim);
In order to get evaluate the flux on the Neumann boundary face we first get the value of the Neumann boundary function on the quadrature points of the face. Then we loop over all the quadrature points and degrees of freedom and approximate the integrals on the Neumann boundary element faces.
std::vector<double > Neumann_bc_values(n_q_points);
for(unsigned int q=0; q<n_q_points; q++)
{
for(unsigned int i=0; i<dofs_per_cell; i++)
{
const Tensor<1, dim> psi_i_field = face_fe[VectorField].value(i,q);
const double psi_i_potential = face_fe[Potential].value(i,q);
for(unsigned int j=0; j<dofs_per_cell; j++)
{
const double psi_j_potential = face_fe[Potential].value(j,q);
We compute contribution for the flux $$\widehat{u}$$ on the Neumann boundary which enters our system matrix as,
$$\int_{\text{face}} \textbf{w} \cdot \textbf{n} \, u \, ds$$
local_matrix(i,j) += psi_i_field *
face_fe.normal_vector(q) *
psi_j_potential *
face_fe.JxW(q);
}
We also compute the contribution for the flux for $$\widehat{q}$$ on the Neumann bounary which is the Neumann boundary condition and enters the right hand side vector as
$$\int_{\text{face}} -w \, g_{N} \, ds$$
local_vector(i) += -psi_i_potential *
Neumann_bc_values[q] *
face_fe.JxW(q);
}
}
}
#### assemble_flux_terms
Now we finally get to the function which builds the interior fluxes. This is a rather long function and we will describe what is going on in detail.
template<int dim>
void
LDGPoissonProblem<dim>::
assemble_flux_terms(
const FEFaceValuesBase<dim> &fe_face_values,
const FEFaceValuesBase<dim> &fe_neighbor_face_values,
FullMatrix<double> &vi_ui_matrix,
FullMatrix<double> &vi_ue_matrix,
FullMatrix<double> &ve_ui_matrix,
FullMatrix<double> &ve_ue_matrix,
const double & h)
{
const unsigned int n_face_points = fe_face_values.n_quadrature_points;
const unsigned int dofs_this_cell = fe_face_values.dofs_per_cell;
const unsigned int dofs_neighbor_cell = fe_neighbor_face_values.dofs_per_cell;
const FEValuesExtractors::Vector VectorField(0);
const FEValuesExtractors::Scalar Potential(dim);
The first thing we do is after the boilerplate is define the unit vector $$\boldsymbol \beta$$ that is used in defining the LDG/ALternating fluxes.
for(int i=0; i<dim; i++)
beta(i) = 1.0;
beta /= sqrt(beta.square() );
Now we loop over all the quadrature points on the element face and loop over all the degrees of freedom and approximate the following flux integrals.
for(unsigned int q=0; q<n_face_points; q++)
{
for(unsigned int i=0; i<dofs_this_cell; i++)
{
const Tensor<1,dim> psi_i_field_minus =
fe_face_values[VectorField].value(i,q);
const double psi_i_potential_minus =
fe_face_values[Potential].value(i,q);
for(unsigned int j=0; j<dofs_this_cell; j++)
{
const Tensor<1,dim> psi_j_field_minus =
fe_face_values[VectorField].value(j,q);
const double psi_j_potential_minus =
fe_face_values[Potential].value(j,q);
We compute the flux matrix where the test function's as well as the solution function's values are taken from the interior as,
$$\int_{\text{face}} \left( \frac{1}{2} \, \textbf{n}^{-} \cdot ( \textbf{w}^{-} u^{-} + w^{-} \textbf{q}^{-}) + \boldsymbol \beta \cdot \textbf{w}^{-} u^{-} - w^{-} \boldsymbol \beta \cdot \textbf{q}^{-} + \sigma w^{-} \, u^{-} \right) ds$$
vi_ui_matrix(i,j) += (0.5 * (
psi_i_field_minus *
fe_face_values.normal_vector(q) *
psi_j_potential_minus
+
psi_i_potential_minus *
fe_face_values.normal_vector(q) *
psi_j_field_minus )
+
beta *
psi_i_field_minus *
psi_j_potential_minus
-
beta *
psi_i_potential_minus *
psi_j_field_minus
+
(penalty/h) *
psi_i_potential_minus *
psi_j_potential_minus
) *
fe_face_values.JxW(q);
}
for(unsigned int j=0; j<dofs_neighbor_cell; j++)
{
const Tensor<1,dim> psi_j_field_plus =
fe_neighbor_face_values[VectorField].value(j,q);
const double psi_j_potential_plus =
fe_neighbor_face_values[Potential].value(j,q);
We compute the flux matrix where the test function is from the interior of this elements face and solution function is taken from the exterior. This corresponds to the computation,
$$\int_{\text{face}} \left( \frac{1}{2} \, \textbf{n}^{-} \cdot ( \textbf{w}^{-} u^{+} + w^{-} \textbf{q}^{+}) - \boldsymbol \beta \cdot \textbf{w}^{-} u^{+} + w^{-} \boldsymbol \beta \cdot \textbf{q}^{+} - \sigma w^{-} \, u^{+} \right) ds$$
vi_ue_matrix(i,j) += ( 0.5 * (
psi_i_field_minus *
fe_face_values.normal_vector(q) *
psi_j_potential_plus
+
psi_i_potential_minus *
fe_face_values.normal_vector(q) *
psi_j_field_plus )
-
beta *
psi_i_field_minus *
psi_j_potential_plus
+
beta *
psi_i_potential_minus *
psi_j_field_plus
-
(penalty/h) *
psi_i_potential_minus *
psi_j_potential_plus
) *
fe_face_values.JxW(q);
}
}
for(unsigned int i=0; i<dofs_neighbor_cell; i++)
{
const Tensor<1,dim> psi_i_field_plus =
fe_neighbor_face_values[VectorField].value(i,q);
const double psi_i_potential_plus =
fe_neighbor_face_values[Potential].value(i,q);
for(unsigned int j=0; j<dofs_this_cell; j++)
{
const Tensor<1,dim> psi_j_field_minus =
fe_face_values[VectorField].value(j,q);
const double psi_j_potential_minus =
fe_face_values[Potential].value(j,q);
We compute the flux matrix where the test function is from the exterior of this elements face and solution function is taken from the interior. This corresponds to the computation,
$$\int_{\text{face}} \left( -\frac{1}{2}\, \textbf{n}^{-} \cdot (\textbf{w}^{+} u^{-} + w^{+} \textbf{q}^{-} ) - \boldsymbol \beta \cdot \textbf{w}^{+} u^{-} + w^{+} \boldsymbol \beta \cdot \textbf{q}^{-} - \sigma w^{+} u^{-} \right) ds$$
ve_ui_matrix(i,j) += (-0.5 * (
psi_i_field_plus *
fe_face_values.normal_vector(q) *
psi_j_potential_minus
+
psi_i_potential_plus *
fe_face_values.normal_vector(q) *
psi_j_field_minus)
-
beta *
psi_i_field_plus *
psi_j_potential_minus
+
beta *
psi_i_potential_plus *
psi_j_field_minus
-
(penalty/h) *
psi_i_potential_plus *
psi_j_potential_minus
) *
fe_face_values.JxW(q);
}
for(unsigned int j=0; j<dofs_neighbor_cell; j++)
{
const Tensor<1,dim> psi_j_field_plus =
fe_neighbor_face_values[VectorField].value(j,q);
const double psi_j_potential_plus =
fe_neighbor_face_values[Potential].value(j,q);
And lastly we compute the flux matrix where the test function and solution function are taken from the exterior cell to this face. This corresponds to the computation,
$$\int_{\text{face}} \left( -\frac{1}{2}\, \textbf{n}^{-} \cdot ( \textbf{w}^{+} u^{+} + w^{+} \textbf{q}^{+} ) + \boldsymbol \beta \cdot \textbf{w}^{+} u^{+} - w^{+} \boldsymbol \beta \cdot \textbf{q}^{+} + \sigma w^{+} u^{+} \right) ds$$
ve_ue_matrix(i,j) += (-0.5 * (
psi_i_field_plus *
fe_face_values.normal_vector(q) *
psi_j_potential_plus
+
psi_i_potential_plus *
fe_face_values.normal_vector(q) *
psi_j_field_plus )
+
beta *
psi_i_field_plus *
psi_j_potential_plus
-
beta *
psi_i_potential_plus *
psi_j_field_plus
+
(penalty/h) *
psi_i_potential_plus *
psi_j_potential_plus
) *
fe_face_values.JxW(q);
}
}
}
}
#### distribute_local_flux_to_global
In this function we use the ConstraintMatrix to distribute the local flux matrices to the global system matrix. Since I have to do this twice in assembling the system matrix, I made function to do it rather than have repeated code. We remark that the reader take special note of the which matrices we are distributing and the order in which we pass the dof indices vectors. In distributing the first matrix, i.e. vi_ui_matrix, we are taking the test function and solution function values from the interior of this cell and therefore only need the local_dof_indices since it contains the dof indices to this cell. When we distribute the second matrix, vi_ue_matrix, the test function is taken form the inteior of this cell while the solution function is taken from the exterior, i.e. the neighbor cell. Notice that the order degrees of freedom index vectors matrch this pattern: first the local_dof_indices which is local to this cell and then the local_neighbor_dof_indices which is local to the neighbor's cell. The order in which we pass the dof indices for the matrices is paramount to constructing our global system matrix properly. The ordering of the last two matrices follow the same logic as the first two we discussed.
template<int dim>
void
LDGPoissonProblem<dim>::
distribute_local_flux_to_global(
const FullMatrix<double> & vi_ui_matrix,
const FullMatrix<double> & vi_ue_matrix,
const FullMatrix<double> & ve_ui_matrix,
const FullMatrix<double> & ve_ue_matrix,
const std::vector<types::global_dof_index> & local_dof_indices,
const std::vector<types::global_dof_index> & local_neighbor_dof_indices)
{
constraints.distribute_local_to_global(vi_ui_matrix,
local_dof_indices,
system_matrix);
constraints.distribute_local_to_global(vi_ue_matrix,
local_dof_indices,
local_neighbor_dof_indices,
system_matrix);
constraints.distribute_local_to_global(ve_ui_matrix,
local_neighbor_dof_indices,
local_dof_indices,
system_matrix);
constraints.distribute_local_to_global(ve_ue_matrix,
local_neighbor_dof_indices,
system_matrix);
}
#### solve
As mentioned earlier I used a direct solver to solve the linear system of equations resulting from the LDG method applied to the Poisson equation. One could also use a iterative sovler, however, we then need to use a preconditoner and that was something I did not wanted to get into. For information on preconditioners for the LDG Method see this paper. The uses of a direct sovler here is somewhat of a limitation. The built-in distributed direct solver in Trilinos reduces everything to one processor, solves the system and then distributes everything back out to the other processors. However, by linking to more advanced direct sovlers through Trilinos one can accomplish fully distributed computations and not much about the following function calls will change.
template<int dim>
void
LDGPoissonProblem<dim>::
solve()
{
TimerOutput::Scope t(computing_timer, "solve");
As in step-40 in order to perform a linear solve we need solution vector where there is no overlap across the processors and we create this by instantiating completely_distributed_solution solution vector using the copy constructor on the global system right hand side vector which itself is completely distributed vector.
completely_distributed_solution(system_rhs);
Now we can preform the solve on the completeley distributed right hand side vector, system matrix and the completely distributed solution.
solver.solve(system_matrix,
completely_distributed_solution,
system_rhs);
We now distribute the constraints of our system onto the completely solution vector, but in our case with the LDG method there are none.
constraints.distribute(completely_distributed_solution);
Lastly we copy the completely distributed solution vector, completely_distributed_solution, to solution vector which has some overlap between processors, locally_relevant_solution. We need the overlapped portions of our solution in order to be able to do computations using the solution later in the code or in post processing.
locally_relevant_solution = completely_distributed_solution;
}
#### output_results
This function deals with the writing of the reuslts in parallel to disk. It is almost exactly the same as in step-40 and we wont go into it. It is noteworthy that in step-40 the output is only the scalar solution, while in our situation, we are outputing both the scalar solution as well as the vector field solution. The only difference between this function and the one in step-40 is in the solution_names vector where we have to add the gradient dimensions. Everything else is taken care of by the deal.ii library!
template<int dim>
void
LDGPoissonProblem<dim>::
output_results() const
{
std::vector<std::string> solution_names;
switch(dim)
{
case 1:
solution_names.push_back("u");
solution_names.push_back("du/dx");
break;
case 2:
solution_names.push_back("u");
break;
case 3:
solution_names.push_back("u");
break;
default:
}
DataOut<dim> data_out;
data_out.attach_dof_handler(dof_handler);
solution_names);
Vector<float> subdomain(triangulation.n_active_cells());
for(unsigned int i=0; i<subdomain.size(); i++)
subdomain(i) = triangulation.locally_owned_subdomain();
data_out.build_patches();
const std::string filename = ("solution." +
triangulation.locally_owned_subdomain(),4));
std::ofstream output((filename + ".vtu").c_str());
data_out.write_vtu(output);
if(Utilities::MPI::this_mpi_process(MPI_COMM_WORLD) == 0 )
{
std::vector<std::string> filenames;
for(unsigned int i=0;
i < Utilities::MPI::n_mpi_processes(MPI_COMM_WORLD);
i++)
{
filenames.push_back("solution." +
".vtu");
}
std::ofstream master_output("solution.pvtu");
data_out.write_pvtu_record(master_output, filenames);
}
}
#### run
The only public function of this class is pretty much exactly the same as all the other deal.ii examples except I setting the constant in the DG penalty ( $$\tilde{\sigma}$$) to be 1.
template<int dim>
void
LDGPoissonProblem<dim>::
run()
{
penalty = 1.0;
make_grid();
make_dofs();
assemble_system();
solve();
output_results();
}
### main
Here it the main class of our program, since it is nearly exactly the same as step-40 and many of the other examples I won't elaborate on it.
int main(int argc, char *argv[])
{
try {
using namespace dealii;
deallog.depth_console(0);
Utilities::MPI::MPI_InitFinalize mpi_initialization(argc, argv,
unsigned int degree = 1;
unsigned int n_refine = 6;
LDGPoissonProblem<2> Poisson(degree, n_refine);
Poisson.run();
}
catch (std::exception &exc)
{
std::cerr << std::endl << std::endl
<< "----------------------------------------------------"
<< std::endl;
std::cerr << "Exception on processing: " << std::endl
<< exc.what() << std::endl
<< "Aborting!" << std::endl
<< "----------------------------------------------------"
<< std::endl;
return 1;
}
catch (...)
{
std::cerr << std::endl << std::endl
<< "----------------------------------------------------"
<< std::endl;
std::cerr << "Unknown exception!" << std::endl
<< "Aborting!" << std::endl
<< "----------------------------------------------------"
<< std::endl;
return 1;
}
return 0;
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https://tsaco.bmj.com/content/5/1/e000460 | Article Text
Efficacy of high-flow nasal prong therapy in trauma patients with rib fractures and high-risk features for respiratory deterioration: a randomized controlled trial
1. Jeremy Ming Hsu1,
2. Peter Telford Clark2,
3. Laura Elizabeth Connell3,
4. Matthew Welfare1
1. Correspondence to Mr Matthew Welfare; Matthew.Welfare{at}health.nsw.gov.au
## Abstract
Background Patients with rib fractures require analgesia, oxygen supplementation and physiotherapy. This combination has been shown to reduce morbidity and mortality due to rib fractures. There has been movement towards the use of high-flow nasal prong (HFNP) oxygen. However there are no studies demonstrating the effectiveness of HFNP in this population. The aim of this study was to compare HFNP to venturi mask (VM) in rib fracture patients.
Methods Randomized controlled trial. Patient population included patients with rib fractures and high-risk features (three or more rib fractures, flail segment, bilateral rib fractures, smoker or chronic obstructive pulmonary disease). Exclusion criteria included initial mechanical ventilation and contraindications to HFNP. Patients were randomized to HFNP or VM. Primary outcome was deterioration requiring mechanical invasive/non‐invasive ventilation, or unplanned admission to intensive care unit. Secondary outcomes included mortality, length of stay, high dependency length of stay, comfort levels, breathing exertion levels (as measured by Borg Scale), oxygen saturation, respiratory rate, heart rate, chest X-ray and arterial blood gas parameters.
Results 220 patients (average age 60 years and average of four rib fractures each) were randomized to HFNP (n=113) and VM (n=107). There was no statistically significant difference in the primary outcome comparing HFNP and VM (6.2% vs. 6.5%, p=1.0). There were also no statistically significant differences in the secondary outcomes except for PaCO2 (43.6 vs. 45.5, p=0.039)
Conclusion HFNP oxygen supplementation does not appear to be more effective than VM oxygen supplementation in patients with rib fractures.
• oxygen inhalation therapy
• rib fractures
This is an open access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited, appropriate credit is given, any changes made indicated, and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/.
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## Introduction
Rib fractures occur commonly as a result of blunt chest trauma and are associated with significant morbidity and mortality due to respiratory failure and pneumonia.1–3 These complications affect up to 25% of patients with rib fractures, and resulting in escalation of care, admission to intensive care units (ICU) and increased length of hospital stays.4 5 Rib fractures are frequently associated with intrathoracic injuries including pulmonary contusions, hemothorax, pneumothorax and aortic injury. Factors that increase the risk of complications from rib fractures include increasing age, number of rib fractures and pre-existing respiratory disease.3 6–8
The two main goals of therapy are pain management and pulmonary care and support. There is strong evidence for providing good analgesia to facilitate volume expansion treatment and chest physiotherapy, aiming for deep breathing and effective cough to reduce secretions and prevent atelectasis.2 8–10 Oxygen supplementation is often included as supportive therapy added to bundles of care for patients with rib fractures.10–12
High-flow nasal prong (HFNP) oxygen (O2) was first developed for neonates and has gained increasing use in adult patients for prevention and treatment of respiratory failure.13 High-flow humidified oxygen with flow rates from 30 to 100 L/min with high fraction of inspired oxygen (FiO2) is able to be delivered.14 There have been proposed benefits of using HFNP O2 including increased comfort, tolerance and increased mucociliary clearance.15–17 Positive end-expiratory pressure can be generated, preventing alveoli collapse. The washout of carbon dioxide (CO2) and replacement with enriched O2 purportedly decreases work of breathing and increases breathing effectiveness.13 14 17–19
There is a significant cost associated with HFNP O2, including the humidifier and the disposable delivery system as well as staff training and labor cost for the management of device.
Although there are studies examining the use of non-invasive ventilation (NIV) for blunt chest trauma,20 there are no studies examining the optimal method of oxygen supplementation in preventing complications related to rib fractures.
The aim of this study was to compare high-flow oxygen therapy to venturi oxygen supplementation in preventing respiratory complications related to rib fractures and also assess patient’s tolerance and comfort with the use of the devices.
## Methods
### Study design
The study was a single-center, prospective randomized controlled trial aimed to assess the efficacy of HFNP therapy in trauma patients with risk factors for respiratory deterioration. Patients were allocated to receive HFNP therapy or oxygen via a venturi mask (VM) according to a computer-generated randomization program. Permuted block randomization was used.
### Setting and participants
All trauma patients presenting to a level 1 trauma center in Sydney, New South Wales, Australia, were assessed for eligibility. The inclusion criteria were patients with rib fractures confirmed with CT imaging and one or more risk factors for respiratory deterioration: age greater than 55 years, three or more rib fractures, bilateral rib fractures, flail segment, smoker or known underlying respiratory disease. Exclusion criteria include: intubation prehospital or in emergency department, contraindication to HFNP (base of skull fracture, unstable facial fractures) and inability to consent (confusion, non-English speaking background).
### Intervention
Patients were randomly allocated using a computer-generated sequence in a 1:1 ratio to either receive HFNP therapy or oxygen via a VM. VM was selected instead of nasal prongs so FiO2 could be accurately delivered.21 All patients were admitted to a high dependency surgical or trauma unit. FiO2 was initiated at 0.4. For patients allocated to HFNP, flow rate was initiated at 60 L/min. All other treatment was as per standard hospital protocol including continuous monitoring in a high dependency unit (HDU), daily chest physiotherapy, analgesia including: paracetamol, non-steroidal anti-inflammatory drugs if not contraindicated, opioids via patient-controlled analgesia device and regional anesthesia as determined by the acute pain service. Patients underwent surgical stabilization of their rib fractures as determined by the attending trauma surgeon. FiO2 for both HFNP and VM was titrated to maintain oxygen saturation (SpO2) ≥95. Patients with advanced chronic obstructive pulmonary disease were given supplementary O2 for SaO2 88% to 92%. For the HFNP cohort, the flow rate was maintained at 60 L/min for at least 24 hours and then until SpO2 was maintained on FiO2 of 0.21.
### Outcomes
The primary outcome was a composite endpoint of unplanned transfer to ICU due to respiratory deterioration, escalation of ventilation support, including NIV and intubation for mechanical ventilation. These patients were ICU medically reviewed and then accepted for admission to ICU due to their increasing respiratory distress and failure.
Secondary outcomes included mortality, hospital length of stay (LOS), HDU LOS and development of pneumonia. Daily measurements were recorded for arterial pH, partial pressure of oxygen in arterial blood (PaO2), partial pressure of carbon dioxide in arterial blood (PaCO2), peak flow and O2 saturations. Comfort levels with the different modes of oxygen delivery were measured with the Likert scale.21 22 The perceived effort of breathing was measured with the modified Borg Scale.23 24 Results for the daily measurements were averaged during the first 3 days after hospital admission.
### Statistical analysis
All statistical analyses were performed using Statistical Package for Social Sciences (SPSS) Predictive Analytics Software (PASW) V.24.0 (SPSS). Continuous data are presented as means and SD or medians and IQR (range from the 25th to the 75th percentile). χ2 test or Fisher’s exact test was used to compare proportions and to test for trends. The Student’s t-test and Mann-Whitney U test were used to compare unpaired groups of continuous data. Univariate analysis identified any significant differences. For all analyses, actual p values were reported and where possible, 95% CIs presented. All tests were two tailed. Differences were considered to be statistically significant at a p<0.05 level.
The sample size was calculated to detect a 15% difference in the primary outcome with α=0.05 and power 80%.
## Results
During the study period 290 patients were screened for inclusion to the study (figure 1). Seventy patients were excluded in total. Thirty-six were excluded due to not meeting study inclusion criteria; 24 patients were unable to be consented; 10 patients refused or were not compliant with HFNP or VM after recruitment and were excluded from the study. On post hoc analysis, none of these exclusions achieved the primary outcome, that is, unplanned admission to ICU/escalation of O2 therapy to invasive ventilation or NIV. Secondary outcome measures were unobtainable due to the patient refusing the required investigations. Therefore, the total number of study participants was 113 in HFNP group and 107 in VM group.
Table 1 demonstrates the demographics and clinical characteristics of included patients.
Table 1
Figure 1
Randomization screening and exclusion flow diagram. HFNP, high-flow nasal prong.
Table 2 shows there was no difference in the rates of unplanned transfer to ICU and/or escalation of ventilatory support between the HFNP group (6.2%) and VM group (6.5%), p=1.0.
Table 2
There was no difference in mortality, high dependency LOS or total hospital LOS, between the two groups. There was no difference in the Likert comfort scale or the modified Borg Scale of perceived breathlessness between the two groups. Respiratory rates and oxygen saturations were no different between the two groups.
Arterial blood gas results showed no difference in pH or PaO2. PaCO2 for HFNP group was lower (43.6 mm Hg, SD=5.6) compared with the VM group (45.5 mm Hg, SD=6.5). This was a statistically significant difference (p=0.032). Peak flow measurement for both groups was not significantly different.
## Discussion
This randomized controlled trial failed to demonstrate a difference in the primary outcome. HFNP did not show a decrease in respiratory complications when compared with oxygen delivery via a VM in trauma patients with rib fractures.
Of the secondary outcomes there was only found to be a slight decrease in PaCO2 level in patients receiving HFNP, with a difference of 2 mm Hg between the averages of the groups. The clinical relevance of this is likely to be minimal.
Overall, a low rate of respiratory complications was observed in both groups (6.2% in the HFNP and 6.4% in the VM group). The effective management of rib fractures requires a bundle of care involving appropriate analgesia from acute pain care team and aggressive early interventions of physiotherapy and pulmonary toilet targeting enhancement of the patient’s functional capacity.4 25
There are no existing studies examining the optimal method of oxygen supplementation for patients with rib fractures. A previous systemic review analyzing nine studies concluded that in appropriately chosen patients early use of NIV in patients with blunt chest trauma might decrease respiratory complications and prevent intubation.26 27 HFNP O2 failed to show benefit in the prevention of respiratory complications over conventional O2 therapy in high-risk respiratory patients with abdominal surgery.27 28
There may be a theoretical benefit with the use of HFNP O2, with increased positive pressure, and humidified oxygen promoting expectoration of secretions. The results of our study suggest that these theoretical benefits may not translate to a clinically significant effect.
It was also hypothesized that the HFNP system would be more comfortable for patients, as only nasal cannulae were required as compared with a mask. However, again, our results would suggest that patients tolerate both systems equally well.
In the setting of modern healthcare, fiscal discipline is required to counter the ever-increasing introduction of technological advancements. Although a formal cost-benefit analysis was not performed, there is a cost difference between the HFNP O2 system and the VM system ($A92.25 vs.$A1.90; approximate at time of writing). The extra costs associated to HFNP are attributed with the disposable items of tubing, humidification system, water for irrigation and the HFNPs of the HFNP devices. VMs are cheaply manufactured and sold.
## Limitations
Power calculations were based on a higher incidence of respiratory deterioration. There was an unexpectedly lower incidence of respiratory deterioration in this study than the incidence used for power calculation.
The study was not blinded to either patients or the treatment team, which may have introduced bias with the decision to escalate therapy. However, the secondary outcomes do not support any significant differences between the groups. This study was also performed in an urban tertiary trauma hospital, hence might not be applicable to smaller centers.
## Conclusion
Oxygen supplementation with HFNP O2 compared with VM oxygen was not shown to be more effective for oxygen supplementation to decrease respiratory complications in trauma patients with rib fractures and high-risk features for respiratory deterioration. There should be consideration for further research to determine if there are any particular groups which may benefit from particular oxygen supplementation systems.
## Acknowledgments
Thanks to all the doctors and nurses at the Westmead Trauma Service and Westmead Hospital HDUs who helped obtain the data and gave advice regarding running of this randomized controlled trial.
View Abstract
## Footnotes
• Contributors All authors contributed to the research project and article writing. JMH: conception of project, submission of ethics and governance approval, data analysis, article writing, review of submission. PTC: conception of project, submission of ethics and governance approval, article writing, review of article. LEC: concept of research project, submission of ethics and governance approval, review of data, article writing, review of article. MW: conception of research project, submission of ethics and governance approval, data collection, article writing, submission of research project for publishing.
• Funding Funding for publication was provided by the Westmead Trauma Research Trust Fund.
• Competing interests None declared.
• Patient consent for publication Not required.
• Ethics approval The study was approved by the Western Sydney Human Research Ethics Committee (AU RED HREC/15/WMEAD/509).
• Provenance and peer review Not commissioned; externally peer reviewed.
• Data availability statement Data are available upon reasonable request. Database securely stored and is available on request.
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http://aimsciences.org/article/doi/10.3934/dcds.2017239 | # American Institue of Mathematical Sciences
2017, 37(11): 5503-5520. doi: 10.3934/dcds.2017239
## Eulerian dynamics with a commutator forcing II: Flocking
1 Department of Mathematics, Statistics, and Computer Science, M/C 249, University of Illinois, Chicago, IL 60607, USA 2 Center for Scientific Computation and Mathematical Modeling (CSCAMM), Department of Mathematics, Institute for Physical Sciences and Technology, University of Maryland, College Park, MD 20742-4015, USA, Current address: Institute for Theoretical Studies (ITS), ETH-Zurich, Clausiusstrasse 47, CH-8092 Zurich, Switzerland
Received January 2017 Revised June 2017 Published July 2017
Fund Project: Research was supported in part by NSF grant DMS 1515705 (RS) and by NSF grants DMS16-13911, RNMS11-07444 (KI-Net) and ONR grant N00014-1512094 (ET)
We continue our study of one-dimensional class of Euler equations, introduced in [11], driven by a forcing with a commutator structure of the form $[{\mathcal L}_φ, u](ρ)$, where $u$ is the velocity field and ${\mathcal L}_φ$ belongs to a rather general class of convolution operators depending on interaction kernels $φ$.
In this paper we quantify the large-time behavior of such systems in terms of fast flocking, for two prototypical sub-classes of kernels: bounded positive $φ$'s, and singular $φ(r) = r^{-(1+α)}$ of order $α∈ [1, 2)$ associated with the action of the fractional Laplacian ${\mathcal L}_φ=-(-\partial_{xx})^{α/2}$. Specifically, we prove fast velocity alignment as the velocity $u(·, t)$ approaches a constant state, $u \to \bar{u}$, with exponentially decaying slope and curvature bounds $|{u_x}( \cdot ,t){|_\infty } + |{u_{xx}}( \cdot ,t){|_\infty }\lesssim{e^{ - \delta t}}$. The alignment is accompanied by exponentially fast flocking of the density towards a fixed traveling state $ρ(·, t) -{ρ_{∞}}(x -\bar{u} t) \to 0$.
Citation: Roman Shvydkoy, Eitan Tadmor. Eulerian dynamics with a commutator forcing II: Flocking. Discrete & Continuous Dynamical Systems - A, 2017, 37 (11) : 5503-5520. doi: 10.3934/dcds.2017239
##### References:
[1] J.A. Carrillo, Y.-P. Choi, E. Tadmor, C. Tan, Critical thresholds in 1D Euler equations with non-local forces, Math. Models Methods Appl. Sci., 26 (2016), 185-206. doi: 10.1142/S0218202516500068. [2] J. Carrillo, Y.-P. Choi, S. Perez, A review on attractive-repulsive hydrodynamics for consensus in collective behavior, Active Particles, Part of the Modeling and Simulation in Science, Engineering and Technology book series (MSSET), (2017), 259-298. doi: 10.1007/978-3-319-49996-3_7. [3] P. Constantin, V. Vicol, Nonlinear maximum principles for dissipative linear nonlocal operators and applications, Geom. Funct. Anal., 22 (2012), 1289-1321. doi: 10.1007/s00039-012-0172-9. [4] T. Do, A. Kiselev, L. Ryzhik and C. Tan, Global regularity for the fractional Euler alignment system, arXiv: 1701. 05155. [5] S.-Y. Ha, E. Tadmor, From particle to kinetic and hydrodynamic descriptions of flocking, Kinetic and Related Models, (2008), 415-435. doi: 10.3934/krm.2008.1.415. [6] C. Imbert, R. Shvydkoy, F. Vigneron, Global well-posedness of a non-local Burgers equation: The periodic case, Annales mathématiques de Toulouse, 25 (2016), 723-758. doi: 10.5802/afst.1509. [7] A. Kiselev, F. Nazarov, A. Volberg, Global well-posedness for the critical 2{D} dissipative quasi-geostrophic equation, Invent. Math., 167 (2007), 445-453. doi: 10.1007/s00222-006-0020-3. [8] S. Motsch, E. Tadmor, A new model for self-organized dynamics and its flocking behavior, J. Stat. Physics, 144 (2011), 923-947. doi: 10.1007/s10955-011-0285-9. [9] S. Motsch, E. Tadmor, Heterophilious dynamics enhances consensus, SIAM Review, 56 (2014), 577-621. doi: 10.1137/120901866. [10] R.W. Schwab, L. Silvestre, Regularity for parabolic integro-differential equations with very irregular kernels, Anal. PDE, 9 (2016), 727-772. doi: 10.2140/apde.2016.9.727. [11] R. Shvydkoy, E. Tadmor, Eulerian dynamics with a commutator forcing, Trans. Math. and Appl., (2017), 1-26. doi: 10.1093/imatrm/tnx001. [12] R. Shvydkoy and E. Tadmor, Eulerian dynamics with a commutator forcing Ⅲ: Fractional diffusion of order 0 < α < 1, arXiv: 1706. 08246}. [13] E. Tadmor and C. Tan, Critical thresholds in flocking hydrodynamics with non-local alignment Philos. Trans. R. Soc. Lond. Ser. A Math. Phys. Eng. Sci. , 372 (2014), 20130401, 22pp.
show all references
##### References:
[1] J.A. Carrillo, Y.-P. Choi, E. Tadmor, C. Tan, Critical thresholds in 1D Euler equations with non-local forces, Math. Models Methods Appl. Sci., 26 (2016), 185-206. doi: 10.1142/S0218202516500068. [2] J. Carrillo, Y.-P. Choi, S. Perez, A review on attractive-repulsive hydrodynamics for consensus in collective behavior, Active Particles, Part of the Modeling and Simulation in Science, Engineering and Technology book series (MSSET), (2017), 259-298. doi: 10.1007/978-3-319-49996-3_7. [3] P. Constantin, V. Vicol, Nonlinear maximum principles for dissipative linear nonlocal operators and applications, Geom. Funct. Anal., 22 (2012), 1289-1321. doi: 10.1007/s00039-012-0172-9. [4] T. Do, A. Kiselev, L. Ryzhik and C. Tan, Global regularity for the fractional Euler alignment system, arXiv: 1701. 05155. [5] S.-Y. Ha, E. Tadmor, From particle to kinetic and hydrodynamic descriptions of flocking, Kinetic and Related Models, (2008), 415-435. doi: 10.3934/krm.2008.1.415. [6] C. Imbert, R. Shvydkoy, F. Vigneron, Global well-posedness of a non-local Burgers equation: The periodic case, Annales mathématiques de Toulouse, 25 (2016), 723-758. doi: 10.5802/afst.1509. [7] A. Kiselev, F. Nazarov, A. Volberg, Global well-posedness for the critical 2{D} dissipative quasi-geostrophic equation, Invent. Math., 167 (2007), 445-453. doi: 10.1007/s00222-006-0020-3. [8] S. Motsch, E. Tadmor, A new model for self-organized dynamics and its flocking behavior, J. Stat. Physics, 144 (2011), 923-947. doi: 10.1007/s10955-011-0285-9. [9] S. Motsch, E. Tadmor, Heterophilious dynamics enhances consensus, SIAM Review, 56 (2014), 577-621. doi: 10.1137/120901866. [10] R.W. Schwab, L. Silvestre, Regularity for parabolic integro-differential equations with very irregular kernels, Anal. PDE, 9 (2016), 727-772. doi: 10.2140/apde.2016.9.727. [11] R. Shvydkoy, E. Tadmor, Eulerian dynamics with a commutator forcing, Trans. Math. and Appl., (2017), 1-26. doi: 10.1093/imatrm/tnx001. [12] R. Shvydkoy and E. Tadmor, Eulerian dynamics with a commutator forcing Ⅲ: Fractional diffusion of order 0 < α < 1, arXiv: 1706. 08246}. [13] E. Tadmor and C. Tan, Critical thresholds in flocking hydrodynamics with non-local alignment Philos. Trans. R. Soc. Lond. Ser. A Math. Phys. Eng. Sci. , 372 (2014), 20130401, 22pp.
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2016 Impact Factor: 1.099 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5877781510353088, "perplexity": 6138.232301092686}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-05/segments/1516084889617.56/warc/CC-MAIN-20180120122736-20180120142736-00589.warc.gz"} |
https://themadphysicist.com/evaluate-integral-using-m/ | # Introduction
For a while, while learning about Numerical Methods for integral, solutions of differential equation, and some other mathematical object, I've come across the Monte Carlo methods. It seemed like some distant method by which we could magically solve a problem. Of course, I knew better, but I avoided it, until I read the book "Partial Differential Equations for Scientists and Engineers" by Stanley J. Farlow.
He explained that Monte Carlo Methods, basically, are methods by which we numerically solve a deterministic problem using probabilistic means. For example, if we try to calculate the integral $\int_0^1 x^2 dx$. We can easily calculate it. $$\int_0^1 x^2 dx=\frac{x^3}{3}\bigg|_0^1=\frac{1}{3}$$
It can also be calculated by Monte Carlo Methods. If we plot the function $x^2$
We know that the integral of the function is the area that is under the curve of the function. So, if we guess in a uniform manner the x and y coordinates on the plot between $0\le x\le 1$ and $0\le y \le 1$, where the y interval coordinates are based on the max and the min of the function in that interval, then, with sufficient guesses, we know that the $\frac{1}{3}$ of the guesses are going to be under the curve of the function.
# Why?
The significance of this is the ability to numerically calculate integrals which are more difficult to calculate, such as the integral $\int_0^1 e^{x^2}$ which doesn't have an obvious analytical solution which doesn't use a special function such as the Error function, which is defined by $erf(x)=\frac{1}{\sqrt{\pi}} \int_{-x}^{x} e^{-t^2} dt$. We can however calculate the integral easily numerically using the Monte Carlo Method.
Monte Carlo Methods are used in various areas of engineering and physicical sciences such as microelectronic engineering, geostatistics molecular dynamics, fluid dynamics, and even marketing analytics. (link1, link2)
# Code
I will be using Octave 4.4.1 which is a free alternative to matlab lacking some of the functionality, but for our uses it will work fine. Download link.
Let's first declare the $f(x)$ function as an anonymous function.
fun = @(x) exp(x.^2);
Set the number of guesses to 1000
% Number of guesses
n = 1000;
We need to set the range for the function on both axes. The x-axis is easy, it's the the interval for the integral; The y-axis in the other hand depends on the function. For this function, we know that the max is at the large end of the interval at $f(1)$.
% x axis
xlow = 0;
xhigh = 1;
% y axis
ylow = 0;
yhigh = fun(xhigh);
The variable to be used to count the number of guesses that are under the is
% Count of guesses under curve
j = 0;
Finally, the loop which will generate the $x$ and $y$ guess, as well as pass the $x$ guess throught the function $f(x)$. Lastly, guessed and actual values are compared so, if the guess is under the curve then $j$ is incremented by 1.
for i = 1:n
% generate random number x
x = xlow + (xhigh - xlow) * rand();
% generate random guess y
gy = ylow + (yhigh - ylow) * rand();
% find real y
fx = fun(x);
% Compare
if (gy < fx)
j = j + 1;
endif
endfor
Calculate the fraction under the curve and multiply it by the area where we were guessing.
% Calculate fraction
frac = j / n;
% Calculate Area
area = (xhigh - xlow) * (yhigh - ylow);
value = frac * area
Running the code I obtained $1.452$ as an answer compared to the actual $1.462$.
# $\pi$
Another cool application is in the calculation of $pi$. We know that the equation for a circle is $x^2+y^2=r^2$, and set $r$, the radius, to $10$. By simplifying and solving for $y$, $y = \sqrt{100-x^2}$. Another given is the area of a circle $A=\pi r^2=100\pi$. If we use this monte carlo method to find the area under the function where $0\le x \le 10$ and $0\le x \le 10$ we can find the area of a quarter of a circle; I will call it $I$ for integral and $I=\frac{A}{4}$. So, $$\pi=\frac{I}{25}$$ where, in this case, $$f(x)=\sqrt{100-x^2}$$
## Code
Let's modify out last code. We will first place the new $f(x)$
fun = @(x) sqrt(100 - x.^2);
The new ranges
xlow = 0;
xhigh 10;
ylow = 0;
yhigh = 10;
After calculating the value for the integral let's divide that by 25
% /\ The rest of the code /\
value = frac * area
value / 25
I obtained the value of $3.1440$ compared to the real value of $3.14159...$
Source Code | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8855159282684326, "perplexity": 570.9940054846716}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-40/segments/1600401585213.82/warc/CC-MAIN-20200928041630-20200928071630-00005.warc.gz"} |
https://www.physicsforums.com/threads/partial-half-life.835306/ | # Partial half-life
Tags:
1. Sep 30, 2015
### jije1112
1. The problem statement, all variables and given/known data
What are the partial half of 22Na for decay by
a)Ec
b) β+ emission
2. Relevant equations
λ=ln2/T1/2
3. The attempt at a solution
this what I do
T1/2 =2.602 Yr
λ=ln2/2.602
λ=0.266 yr-1
what is the difference between
a)Ec
b) β+ emission
there is no Percentage of each decay type.!
2. Sep 30, 2015
### Orodruin
Staff Emeritus
Of course there is. You can look it up in any table of decays or find it online by doing a quick Google search!
Draft saved Draft deleted
Similar Discussions: Partial half-life | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9478431940078735, "perplexity": 11075.608364543836}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-51/segments/1512948596051.82/warc/CC-MAIN-20171217132751-20171217154751-00444.warc.gz"} |
http://science.sciencemag.org/content/153/3731/54 | Reports
# Chondrules: Suggestion Concerning the Origin
See allHide authors and affiliations
Science 01 Jul 1966:
Vol. 153, Issue 3731, pp. 54-56
DOI: 10.1126/science.153.3731.54
## Abstract
The millimeter-sized, sometimes glassy spheroids called chondrules that occur abundantly in stony meteorites may have been produced by lightning in the primitive Laplaciantype nebula while earthy materials were condensing and collecting to form the asteroids and the terrestrial planets. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9067727327346802, "perplexity": 25997.2247852355}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-43/segments/1508187825700.38/warc/CC-MAIN-20171023054654-20171023074654-00855.warc.gz"} |
https://brilliant.org/problems/what-an-amusing-nested-radical/ | # What an Amusing Nested Radical!
Calculus Level 3
$\Large \sqrt{2\sqrt[3]{2\sqrt[4]{2\sqrt[5]{2\cdots}}}}$
Let the value of the above expression be denoted by $I$. Find $\lfloor1000I\rfloor$.
Details and Assumptions:
You may use a scientific calculator to evaluate the final result.
× | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 3, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8068901300430298, "perplexity": 2001.1517437982188}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-05/segments/1579251681412.74/warc/CC-MAIN-20200125191854-20200125221854-00278.warc.gz"} |
https://itectec.com/superuser/networking-how-to-shutdown-a-computer-on-the-network/ | # Networking – How to shutdown a computer on the network
batchnetworkingshutdown
I want to shutdown a computer on my network at home. When I try the usual 'shutdown' command, I get the 'Access denied (5)' message. In what way must my computer be connected with the other computer in order for me to take control? | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8756076693534851, "perplexity": 2642.224170075132}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-49/segments/1637964363290.59/warc/CC-MAIN-20211206072825-20211206102825-00308.warc.gz"} |
https://chem.libretexts.org/Bookshelves/Organic_Chemistry/Book%3A_Polymer_Chemistry_(Schaller)/03%3A_Kinetics_and_Thermodynamics_of_Polymerization/3.04%3A_Kinetics_of_Catalytic_Polymerization | # 3.4: Kinetics of Catalytic Polymerization
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KP4. Kinetics of Catalytic Polymerization
The Ziegler-Natta polymerization of alkenes is conducted under catalytic conditions. In most cases, the process involves heterogeneous catalysis, in which the reaction takes place on the surface of a solid. The kinetics of catalyzed reactions have some features that are different from other reactions and that are worth exploring.
The fact that the reaction is taking place on the surface of a solid is a key feature that must be stressed in the kinetics of heterogeneous catalysis. The treatment of rates therefore uses an approach developed by Irving Langmuir, a long-time scientist at General Electric who was awarded the Nobel Prize for the study of surfaces. One of the things that makes metal catalysts so useful is their ability to adsorb molecules on their surfaces (think of the precious metals used in catalytic hydrogenation, adsorbing alkenes and hydrogen; or the iron in the Haber-Bosch synthesis of ammonia, adsorbing dinitrogen and hydrogen, to cite two important examples). "Adsorption" refers to the adhesion of molecules to a surface. Langmuir thought of this adsorption process as a dynamic one, with molecules landing on and sticking to open spots on a surface even as other molecules lifted off to create vacancies.
Desorption, on the other hand, refers to the process of molecules leaving the surface.
In terms of kinetics, the rate of desorption of a molecule would depend on some rate constant, kd, and the fraction of the surface covered by these molecules, θ (that's the Greek letter, theta). The greater the surface fraction covered by molecules, the greater the chance that you will encounter one desorbing.
Rated = kd θ
On the other hand, the rate os adsorption of a molecule onto a surface will depend on some rate constant ka, the concentration of the molecule to be adsorbed, and the fraction of the surface still available. That last part is 1 - θ, because the fraction covered plus the fraction uncovered would equal the whole. Note that Langmuir was interested in gas phase molecules adsorbing onto a surface, and so he expressed things in terms of pressure rather than concentration.
Ratea = ka (1 - θ) [M]
At equilibrium, these two rates will equal each other:
kd θ = ka [M] - ka θ [M]
θ (kd + ka [M]) = ka [M]
θ = ka [M] / (kd + ka [M])
Now we have an expression for the fraction of the surface covered by the substrate. This term is called the "Langmuir isotherm" and it shows up in various surface and catalytic phenomena. It is usually expressed slightly differently, in terms of an equilibrium constant for adsorption:
The rate of a reaction catalyzed on that surface will depend on the catalyst concentration as well as a rate constant for enchainment, kprop or simply kp, and the amount of surface covered by monomer (unbound monomer will not undergo propagation). An additional factor, x*, takes into account the fact that only a fraction of the catalyst is active.
Superficially, the form of the rate law has something in common with the Michaelis-Menten equation, with which you may already be familiar. The Michaelis-Menten equation relates the rate of an enzyme-catalyzed reaction to enzyme concentration, the rate constant for the catalytic reaction, and rate constants for reversible substrate binding with the enzyme.
Maybe that resemblance shouldn't be too surprising. After all, both equations describe catalytic processes, in which either the surface or the binding site must accomodate the substrate so as to carry out a subsequent series of reactions. Both equations take the form of a saturation curve, indicating that the rate of reaction will level out if the surface or binding site becomes fully occupied.
Problem KP4.1.
One way to evaluate multi-term relationships is to consider what happens under different conditions. What happens to the rate law for catalytic polymerization if monomer concentration is very low, so that 1 >> Keq[M]?
Problem KP4.2.
What happens to the rate law for catalytic polymerization if monomer concentration is very high, so that Keq[M] >> 1?
3.4: Kinetics of Catalytic Polymerization is shared under a CC BY-NC 4.0 license and was authored, remixed, and/or curated by LibreTexts. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8900195956230164, "perplexity": 1287.494540717286}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-21/segments/1652662540268.46/warc/CC-MAIN-20220521174536-20220521204536-00066.warc.gz"} |
https://www.cvxpy.org/examples/applications/robust_kalman.html | # Robust Kalman filtering for vehicle tracking¶
We will try to pinpoint the location of a moving vehicle with high accuracy from noisy sensor data. We’ll do this by modeling the vehicle state as a discrete-time linear dynamical system. Standard Kalman filtering can be used to approach this problem when the sensor noise is assumed to be Gaussian. We’ll use robust Kalman filtering to get a more accurate estimate of the vehicle state for a non-Gaussian case with outliers.
# Problem statement¶
A discrete-time linear dynamical system consists of a sequence of state vectors $$x_t \in \mathbf{R}^n$$, indexed by time $$t \in \lbrace 0, \ldots, N-1 \rbrace$$ and dynamics equations
\begin{split}\begin{align} x_{t+1} &= Ax_t + Bw_t\\ y_t &=Cx_t + v_t, \end{align}\end{split}
where $$w_t \in \mathbf{R}^m$$ is an input to the dynamical system (say, a drive force on the vehicle), $$y_t \in \mathbf{R}^r$$ is a state measurement, $$v_t \in \mathbf{R}^r$$ is noise, $$A$$ is the drift matrix, $$B$$ is the input matrix, and $$C$$ is the observation matrix.
Given $$A$$, $$B$$, $$C$$, and $$y_t$$ for $$t = 0, \ldots, N-1$$, the goal is to estimate $$x_t$$ for $$t = 0, \ldots, N-1$$.
# Kalman filtering¶
A Kalman filter estimates $$x_t$$ by solving the optimization problem
$\begin{split}\begin{array}{ll} \mbox{minimize} & \sum_{t=0}^{N-1} \left( \|w_t\|_2^2 + \tau \|v_t\|_2^2\right)\\ \mbox{subject to} & x_{t+1} = Ax_t + Bw_t,\quad t=0,\ldots, N-1\\ & y_t = Cx_t+v_t,\quad t = 0, \ldots, N-1, \end{array}\end{split}$
where $$\tau$$ is a tuning parameter. This problem is actually a least squares problem, and can be solved via linear algebra, without the need for more general convex optimization. Note that since we have no observation $$y_{N}$$, $$x_N$$ is only constrained via $$x_{N} = Ax_{N-1} + Bw_{N-1}$$, which is trivially resolved when $$w_{N-1} = 0$$ and $$x_{N} = Ax_{N-1}$$. We maintain this vestigial constraint only because it offers a concise problem statement.
This model performs well when $$w_t$$ and $$v_t$$ are Gaussian. However, the quadratic objective can be influenced by large outliers, which degrades the accuracy of the recovery. To improve estimation in the presence of outliers, we can use robust Kalman filtering.
# Robust Kalman filtering¶
To handle outliers in $$v_t$$, robust Kalman filtering replaces the quadratic cost with a Huber cost, which results in the convex optimization problem
$\begin{split}\begin{array}{ll} \mbox{minimize} & \sum_{t=0}^{N-1} \left( \|w_t\|^2_2 + \tau \phi_\rho(v_t) \right)\\ \mbox{subject to} & x_{t+1} = Ax_t + Bw_t,\quad t=0,\ldots, N-1\\ & y_t = Cx_t+v_t,\quad t=0,\ldots, N-1, \end{array}\end{split}$
where $$\phi_\rho$$ is the Huber function
$\begin{split}\phi_\rho(a)= \left\{ \begin{array}{ll} \|a\|_2^2 & \|a\|_2\leq \rho\\ 2\rho \|a\|_2-\rho^2 & \|a\|_2>\rho. \end{array}\right.\end{split}$
The Huber penalty function penalizes estimation error linearly outside of a ball of radius $$\rho$$, whereas in standard Kalman filtering, all errors are penalized quadratically. Thus, large errors are penalized less harshly, making this model more robust to outliers.
# Vehicle tracking example¶
We’ll apply standard and robust Kalman filtering to a vehicle tracking problem with state $$x_t \in \mathbf{R}^4$$, where $$(x_{t,0}, x_{t,1})$$ is the position of the vehicle in two dimensions, and $$(x_{t,2}, x_{t,3})$$ is the vehicle velocity. The vehicle has unknown drive force $$w_t$$, and we observe noisy measurements of the vehicle’s position, $$y_t \in \mathbf{R}^2$$.
The matrices for the dynamics are
$\begin{split}A = \begin{bmatrix} 1 & 0 & \left(1-\frac{\gamma}{2}\Delta t\right) \Delta t & 0 \\ 0 & 1 & 0 & \left(1-\frac{\gamma}{2} \Delta t\right) \Delta t\\ 0 & 0 & 1-\gamma \Delta t & 0 \\ 0 & 0 & 0 & 1-\gamma \Delta t \end{bmatrix},\end{split}$
$\begin{split}B = \begin{bmatrix} \frac{1}{2}\Delta t^2 & 0 \\ 0 & \frac{1}{2}\Delta t^2 \\ \Delta t & 0 \\ 0 & \Delta t \\ \end{bmatrix},\end{split}$
$\begin{split}C = \begin{bmatrix} 1 & 0 & 0 & 0 \\ 0 & 1 & 0 & 0 \end{bmatrix},\end{split}$
where $$\gamma$$ is a velocity damping parameter.
# 1D Model¶
The recurrence is derived from the following relations in a single dimension. For this subsection, let $$x_t, v_t, w_t$$ be the vehicle position, velocity, and input drive force. The resulting acceleration of the vehicle is $$w_t - \gamma v_t$$, with $$- \gamma v_t$$ is a damping term depending on velocity with parameter $$\gamma$$.
The discretized dynamics are obtained from numerically integrating:
\begin{split}\begin{align} x_{t+1} &= x_t + \left(1-\frac{\gamma \Delta t}{2}\right)v_t \Delta t + \frac{1}{2}w_{t} \Delta t^2\\ v_{t+1} &= \left(1-\gamma\right)v_t + w_t \Delta t. \end{align}\end{split}
Extending these relations to two dimensions gives us the dynamics matrices $$A$$ and $$B$$.
## Helper Functions¶
import matplotlib
import matplotlib.pyplot as plt
import numpy as np
def plot_state(t,actual, estimated=None):
'''
plot position, speed, and acceleration in the x and y coordinates for
the actual data, and optionally for the estimated data
'''
trajectories = [actual]
if estimated is not None:
trajectories.append(estimated)
fig, ax = plt.subplots(3, 2, sharex='col', sharey='row', figsize=(8,8))
for x, w in trajectories:
ax[0,0].plot(t,x[0,:-1])
ax[0,1].plot(t,x[1,:-1])
ax[1,0].plot(t,x[2,:-1])
ax[1,1].plot(t,x[3,:-1])
ax[2,0].plot(t,w[0,:])
ax[2,1].plot(t,w[1,:])
ax[0,0].set_ylabel('x position')
ax[1,0].set_ylabel('x velocity')
ax[2,0].set_ylabel('x input')
ax[0,1].set_ylabel('y position')
ax[1,1].set_ylabel('y velocity')
ax[2,1].set_ylabel('y input')
ax[0,1].yaxis.tick_right()
ax[1,1].yaxis.tick_right()
ax[2,1].yaxis.tick_right()
ax[0,1].yaxis.set_label_position("right")
ax[1,1].yaxis.set_label_position("right")
ax[2,1].yaxis.set_label_position("right")
ax[2,0].set_xlabel('time')
ax[2,1].set_xlabel('time')
def plot_positions(traj, labels, axis=None,filename=None):
'''
show point clouds for true, observed, and recovered positions
'''
matplotlib.rcParams.update({'font.size': 14})
n = len(traj)
fig, ax = plt.subplots(1, n, sharex=True, sharey=True,figsize=(12, 5))
if n == 1:
ax = [ax]
for i,x in enumerate(traj):
ax[i].plot(x[0,:], x[1,:], 'ro', alpha=.1)
ax[i].set_title(labels[i])
if axis:
ax[i].axis(axis)
if filename:
fig.savefig(filename, bbox_inches='tight')
## Problem Data¶
We generate the data for the vehicle tracking problem. We’ll have $$N=1000$$, $$w_t$$ a standard Gaussian, and $$v_t$$ a standard Gaussian, except $$20\%$$ of the points will be outliers with $$\sigma = 20$$.
Below, we set the problem parameters and define the matrices $$A$$, $$B$$, and $$C$$.
n = 1000 # number of timesteps
T = 50 # time will vary from 0 to T with step delt
ts, delt = np.linspace(0,T,n,endpoint=True, retstep=True)
gamma = .05 # damping, 0 is no damping
A = np.zeros((4,4))
B = np.zeros((4,2))
C = np.zeros((2,4))
A[0,0] = 1
A[1,1] = 1
A[0,2] = (1-gamma*delt/2)*delt
A[1,3] = (1-gamma*delt/2)*delt
A[2,2] = 1 - gamma*delt
A[3,3] = 1 - gamma*delt
B[0,0] = delt**2/2
B[1,1] = delt**2/2
B[2,0] = delt
B[3,1] = delt
C[0,0] = 1
C[1,1] = 1
# Simulation¶
We seed $$x_0 = 0$$ (starting at the origin with zero velocity) and simulate the system forward in time. The results are the true vehicle positions x_true (which we will use to judge our recovery) and the observed positions y.
We plot the position, velocity, and system input $$w$$ in both dimensions as a function of time. We also plot the sets of true and observed vehicle positions.
sigma = 20
p = .20
np.random.seed(6)
x = np.zeros((4,n+1))
x[:,0] = [0,0,0,0]
y = np.zeros((2,n))
# generate random input and noise vectors
w = np.random.randn(2,n)
v = np.random.randn(2,n)
np.random.seed(0)
inds = np.random.rand(n) <= p
v[:,inds] = sigma*np.random.randn(2,n)[:,inds]
# simulate the system forward in time
for t in range(n):
y[:,t] = C.dot(x[:,t]) + v[:,t]
x[:,t+1] = A.dot(x[:,t]) + B.dot(w[:,t])
x_true = x.copy()
w_true = w.copy()
plot_state(ts,(x_true,w_true))
plot_positions([x_true,y], ['True', 'Observed'],[-4,14,-5,20],'rkf1.pdf')
# Kalman filtering recovery¶
The code below solves the standard Kalman filtering problem using CVXPY. We plot and compare the true and recovered vehicle states. Note that the recovery is distorted by outliers in the measurements.
%%time
import cvxpy as cp
x = cp.Variable(shape=(4, n+1))
w = cp.Variable(shape=(2, n))
v = cp.Variable(shape=(2, n))
tau = .08
obj = cp.sum_squares(w) + tau*cp.sum_squares(v)
obj = cp.Minimize(obj)
constr = []
for t in range(n):
constr += [ x[:,t+1] == A*x[:,t] + B*w[:,t] ,
y[:,t] == C*x[:,t] + v[:,t] ]
cp.Problem(obj, constr).solve(verbose=True)
x = np.array(x.value)
w = np.array(w.value)
plot_state(ts,(x_true,w_true),(x,w))
plot_positions([x_true,y], ['True', 'Noisy'], [-4,14,-5,20])
plot_positions([x_true,x], ['True', 'KF recovery'], [-4,14,-5,20], 'rkf2.pdf')
print("optimal objective value: {}".format(obj.value))
-----------------------------------------------------------------
OSQP v0.4.1 - Operator Splitting QP Solver
(c) Bartolomeo Stellato, Goran Banjac
University of Oxford - Stanford University 2018
-----------------------------------------------------------------
problem: variables n = 8004, constraints m = 6000
nnz(P) + nnz(A) = 22000
settings: linear system solver = qdldl,
eps_abs = 1.0e-03, eps_rel = 1.0e-03,
eps_prim_inf = 1.0e-04, eps_dual_inf = 1.0e-04,
sigma = 1.00e-06, alpha = 1.60, max_iter = 4000
check_termination: on (interval 25),
scaling: on, scaled_termination: off
warm start: on, polish: on
iter objective pri res dua res rho time
1 0.0000e+00 6.14e+01 6.14e+03 1.00e-01 1.28e-02s
50 1.1057e+04 3.57e-07 8.27e-08 1.00e-01 3.01e-02s
plsh 1.1057e+04 7.11e-15 1.24e-14 -------- 3.78e-02s
status: solved
solution polish: successful
number of iterations: 50
optimal objective: 11057.3550
run time: 3.78e-02s
optimal rho estimate: 7.70e-02
optimal objective value: 11057.354957764113
CPU times: user 13 s, sys: 598 ms, total: 13.6 s
Wall time: 13.8 s
# Robust Kalman filtering recovery¶
Here we implement robust Kalman filtering with CVXPY. We get a better recovery than the standard Kalman filtering, which can be seen in the plots below.
%%time
import cvxpy as cp
x = cp.Variable(shape=(4, n+1))
w = cp.Variable(shape=(2, n))
v = cp.Variable(shape=(2, n))
tau = 2
rho = 2
obj = cp.sum_squares(w)
obj += cp.sum([tau*cp.huber(cp.norm(v[:,t]),rho) for t in range(n)])
obj = cp.Minimize(obj)
constr = []
for t in range(n):
constr += [ x[:,t+1] == A*x[:,t] + B*w[:,t] ,
y[:,t] == C*x[:,t] + v[:,t] ]
cp.Problem(obj, constr).solve(verbose=True)
x = np.array(x.value)
w = np.array(w.value)
plot_state(ts,(x_true,w_true),(x,w))
plot_positions([x_true,y], ['True', 'Noisy'], [-4,14,-5,20])
plot_positions([x_true,x], ['True', 'Robust KF recovery'], [-4,14,-5,20],'rkf3.pdf')
print("optimal objective value: {}".format(obj.value))
ECOS 2.0.4 - (C) embotech GmbH, Zurich Switzerland, 2012-15. Web: www.embotech.com/ECOS
It pcost dcost gap pres dres k/t mu step sigma IR | BT
0 +0.000e+00 -2.923e+02 +7e+05 3e-01 3e-02 1e+00 2e+02 --- --- 1 1 - | - -
1 +5.090e+02 +4.360e+02 +2e+05 4e-01 1e-02 3e+01 6e+01 0.8051 2e-01 2 1 1 | 0 0
2 +4.188e+03 +4.134e+03 +2e+05 3e-01 9e-03 3e+01 5e+01 0.4259 6e-01 1 1 1 | 0 0
3 +9.956e+03 +9.923e+03 +1e+05 3e-01 8e-03 4e+01 4e+01 0.5830 5e-01 1 1 2 | 0 0
4 +1.881e+04 +1.880e+04 +7e+04 3e-01 5e-03 3e+01 2e+01 0.7189 3e-01 1 1 1 | 0 0
5 +2.572e+04 +2.572e+04 +4e+04 2e-01 3e-03 2e+01 1e+01 0.5464 3e-01 1 1 1 | 0 0
6 +2.986e+04 +2.985e+04 +3e+04 2e-01 2e-03 1e+01 6e+00 0.5716 3e-01 2 2 1 | 0 0
7 +3.262e+04 +3.262e+04 +1e+04 9e-02 1e-03 7e+00 3e+00 0.6007 2e-01 2 2 2 | 0 0
8 +3.425e+04 +3.425e+04 +8e+03 5e-02 7e-04 5e+00 2e+00 0.5871 3e-01 2 2 2 | 0 0
9 +3.601e+04 +3.601e+04 +4e+03 3e-02 3e-04 2e+00 9e-01 0.6383 2e-01 2 2 2 | 0 0
10 +3.728e+04 +3.727e+04 +2e+03 1e-02 2e-04 1e+00 5e-01 0.7925 4e-01 2 2 2 | 0 0
11 +3.759e+04 +3.759e+04 +1e+03 1e-02 1e-04 1e+00 3e-01 0.5191 5e-01 2 2 2 | 0 0
12 +3.824e+04 +3.824e+04 +6e+02 6e-03 5e-05 5e-01 2e-01 0.9890 4e-01 2 2 2 | 0 0
13 +3.860e+04 +3.860e+04 +3e+02 3e-03 2e-05 3e-01 7e-02 0.6740 2e-01 2 2 2 | 0 0
14 +3.864e+04 +3.864e+04 +3e+02 3e-03 2e-05 3e-01 7e-02 0.2982 7e-01 2 2 3 | 0 0
15 +3.876e+04 +3.876e+04 +2e+02 2e-03 1e-05 2e-01 4e-02 0.9890 6e-01 2 2 2 | 0 0
16 +3.889e+04 +3.889e+04 +8e+01 1e-03 4e-06 1e-01 2e-02 0.7740 4e-01 3 3 3 | 0 0
17 +3.899e+04 +3.899e+04 +2e+01 4e-04 1e-06 3e-02 6e-03 0.9702 3e-01 3 3 3 | 0 0
18 +3.901e+04 +3.901e+04 +1e+01 4e-04 6e-07 3e-02 4e-03 0.6771 5e-01 4 3 3 | 0 0
19 +3.903e+04 +3.903e+04 +7e+00 2e-04 3e-07 2e-02 2e-03 0.9383 5e-01 3 2 3 | 0 0
20 +3.905e+04 +3.905e+04 +2e+00 1e-04 1e-07 1e-02 6e-04 0.8982 3e-01 4 4 4 | 0 0
21 +3.906e+04 +3.906e+04 +9e-01 5e-05 5e-08 5e-03 2e-04 0.9342 3e-01 3 2 3 | 0 0
22 +3.907e+04 +3.907e+04 +3e-01 4e-05 3e-08 4e-03 8e-05 0.8457 3e-01 5 4 4 | 0 0
23 +3.908e+04 +3.908e+04 +8e-02 1e-05 8e-09 1e-03 2e-05 0.9890 3e-01 3 3 3 | 0 0
24 +3.908e+04 +3.908e+04 +1e-02 2e-06 2e-09 2e-04 3e-06 0.9013 5e-02 3 3 3 | 0 0
25 +3.908e+04 +3.908e+04 +2e-03 4e-07 4e-10 4e-05 5e-07 0.9207 8e-02 3 2 2 | 0 0
26 +3.908e+04 +3.908e+04 +7e-04 2e-07 2e-10 2e-05 2e-07 0.9890 4e-01 2 2 2 | 0 0
27 +3.908e+04 +3.908e+04 +8e-05 3e-08 5e-11 2e-06 2e-08 0.9009 2e-02 2 2 2 | 0 0
28 +3.908e+04 +3.908e+04 +2e-05 1e-08 2e-11 4e-07 5e-09 0.9890 2e-01 2 2 2 | 0 0
29 +3.908e+04 +3.908e+04 +2e-06 3e-09 5e-12 5e-08 5e-10 0.9058 2e-02 2 1 1 | 0 0
OPTIMAL (within feastol=3.1e-09, reltol=5.3e-11, abstol=2.1e-06).
Runtime: 1.129066 seconds.
optimal objective value: 39077.76954636933
CPU times: user 3min 37s, sys: 3.44 s, total: 3min 41s
Wall time: 3min 55s | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 2, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8214197754859924, "perplexity": 2469.56000382737}, "config": {"markdown_headings": true, "markdown_code": false, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-31/segments/1627046154408.7/warc/CC-MAIN-20210802234539-20210803024539-00639.warc.gz"} |
https://www.math.ucdavis.edu/research/seminars/?talk_id=1060 | # Mathematics Colloquia and Seminars
Associated with an $n \times m$ matrix $A=(a_{ij})$ is the $n$-homogeneous polynomial in $m$ variables: P_A=\Prod_{i=1}^n ( \sum_{j=1}^m a_{ij}X_j). An assignment vector X=(x_1,\dots,x_m) clearly satisfies $P_A(X)$ non-zero if and only if the vector $AX$ admits no zero entry. The above provides an algebraic platform for some fundamental questions in Combinatorics to be restated. For example, if A is the incidence matrix of edges and vertices of a graph $G=(V={v_1,dots,v_n},E), then$P_A$is the graph polynomial$P_G\$, a proper coloring of G is a vector C of color for which P_G(C) is not zero. The vast body of knowledge about zeros of polynomials, located at the very core of algebra, is hence a potential contributor to the study of graph coloring and related problems in graph theory and Matroid theory. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.6752527952194214, "perplexity": 375.62758984854315}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-30/segments/1531676589726.60/warc/CC-MAIN-20180717125344-20180717145344-00093.warc.gz"} |
https://repository.uantwerpen.be/link/irua/81520 | Title Investigation of colour reconnection in WW events with the DELPHI detector at LEP-2 Author Abdallah, J. Van Remortel, N. et al. Faculty/Department Faculty of Sciences. Physics Publication type article Publication 2007 Berlin , 2007 Subject Physics Source (journal) European physical journal : C : particles and fields. - Berlin Volume/pages 51(2007) :2 , p. 249-269 ISSN 1434-6044 ISI 000248261900001 Carrier E Target language English (eng) Full text (Publishers DOI) Abstract In the reaction e+e-→WW→(q1q̄2)(q3q̄4) the usual hadronization models treat the colour singlets q1q̄2 and q3q̄4 coming from two W bosons independently. However, since the final state partons may coexist in space and time, cross-talk between the two evolving hadronic systems may be possible during fragmentation through soft gluon exchange. This effect is known as colour reconnection. In this article the results of the investigation of colour reconnection effects in fully hadronic decays of W pairs in DELPHI at LEP are presented. Two complementary analyses were performed, studying the particle flow between jets and W mass estimators, with negligible correlation between them, and the results were combined and compared to models. In the framework of the SK-I model, the value for its κ parameter most compatible with the data was found to be: κSK-I=2.2+2.5 -1.3 corresponding to the probability of reconnection $\mathcal{P}_{\text{reco}}$ to be in the range $0.31 <\mathcal{P}_{{\text{reco}}} < 0.68$ at 68% confidence level with its best value at 0.52. E-info http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000248261900001&DestLinkType=RelatedRecords&DestApp=ALL_WOS&UsrCustomerID=ef845e08c439e550330acc77c7d2d848 http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000248261900001&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=ef845e08c439e550330acc77c7d2d848 http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000248261900001&DestLinkType=CitingArticles&DestApp=ALL_WOS&UsrCustomerID=ef845e08c439e550330acc77c7d2d848 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7706224322319031, "perplexity": 4689.579432770682}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-13/segments/1490218188717.24/warc/CC-MAIN-20170322212948-00340-ip-10-233-31-227.ec2.internal.warc.gz"} |
https://nilesjohnson.net/Aof2/ | # Visualization of $$\mathcal{A}(2)$$
Robert Bruner and Niles Johnson, 2013
The diagram below displays the Steenrod subalgebra $$\mathcal{A}(2)$$ by its decomposition into eight left cosets of $$\mathcal{A}(1)$$. The left action of $$Sq^1$$, $$Sq^2$$, and $$Sq^4$$ is displayed upon clicking dots.
The "Basis type" options determine whether elements are displayed in the Adem (admissible) basis, Milnor basis, or not displayed. The "Generator" menu selects a subset of the generators to act on the selected dot by left multiplication. Multiplications which result in a sum are shown by highlighting all summands, and multiplications which result in zero are shown in the upper left corner.
### New
Click the zebra icon to highlight the nice type-2 spectrum $$\mathcal{Z}$$ constructed by Prasit Bhattacharya and Philip Egger. (The remaining copies of of $$\mathcal{A}(1)$$ form another copy of $$\mathcal{Z}$$ suspended 7 times.)
•
• Basis type
• Generator
## Explanation of the display
It is (just barely) possible to represent $$\mathcal{A}(2)$$ by drawing dots representing a basis for it, together with lines representing the left action of $$Sq^1$$, $$Sq^2$$, and $$Sq^4$$ (see drawings of Andre Henriques and Bert Guillou).
The representation here does not show all the multiplicative structure simultaneously. We break $$\mathcal{A}(2)$$ into the 8 left cosets of $$\mathcal{A}(1)$$ and give an interactive display of left multiplication by the generators. This has several useful features:
• It is 'even-handed', giving 8 subsets of size 8.
• It is well related to $$ko$$-theory.
• It has a simple form, since $$\mathcal{A}(2)/\!/\mathcal{A}(1) = \mathcal{A}(2)/\mathcal{A}(2)(Sq^1,Sq^2)$$ is concentrated in dimensions 0, 4, 6, 7, 10, 11, 13 and 17.
These cosets are represented by the following elements, which appear along the top of the diagram:
\begin{align} 1 & \\ Sq^4 & \\ Sq^2 Sq^4 & = Sq^6 + Sq^5 Sq^1 \\ Sq^1 Sq^2 Sq^4 = Sq^3 Sq^4 & = Sq^7 \\ Sq^4 Sq^2 Sq^4 & = Sq^{10} + Sq^9 Sq^1 + Sq^8 Sq^2 + Sq^7 Sq^2 Sq^1 \\ Sq^4 Sq^3 Sq^4 = Sq^5 Sq^2 Sq^4 & = Sq^{11} + Sq^9 Sq^2 \\ Sq^2 Sq^4 Sq^3 Sq^4 & = Sq^{13} + Sq^{12} Sq^1 + Sq^{10} Sq^3 \\ Sq^4 Sq^2 Sq^4 Sq^3 Sq^4 & = Sq^{17} + Sq^{16} Sq^1 + Sq^{15} Sq^2 + Sq^{14} Sq^2 Sq^1 + Sq^{12} Sq^5 + Sq^{12} Sq^4 Sq^1 \end{align}
When $$x$$ is one of these 8 representatives, the copy of $$\mathcal{A}(1)$$ 'hanging' from $$x$$ contains all the elements in $$x\mathcal{A}(1)$$.
This gives a description of each element in terms of the generators $$Sq^1$$, $$Sq^2$$, and $$Sq^4$$ in the form $$xy$$, where $$x$$ is one of the 8 coset representatives above and $$y$$ is an element of $$\mathcal{A}(1)$$. For example, the third element from the top in the third group from the left has the representation $$(Sq^2 Sq^4)(Sq^2)$$. In the admissable basis, this is $$Sq^6 Sq^2$$, which is shown when this dot is selected and the "Adem" menu option is on.
Thus, the cosets are given by left multiplications, while the elements within each coset are given by right multiplications. In this form, the left action of $$\mathcal{A}(2)$$ on itself is not completely clear. Some information is visible in the lines connecting cosets of $$\mathcal{A}(1)$$, and the rest is displayed by the left action of $$Sq^1$$, $$Sq^2$$, and $$Sq^4$$.
$$1$$
$$1$$
$$Sq^1$$
$$Sq(1)$$
$$Sq^2$$
$$Sq(2)$$
$$Sq^3$$
$$Sq(3)$$
$$Sq^2 Sq^1$$
$$Sq(3) + Sq(0,1)$$
$$Sq^3 Sq^1$$
$$Sq(1,1)$$
$$Sq^5 + Sq^4 Sq^1$$
$$Sq(2,1)$$
$$Sq^5 Sq^1$$
$$Sq(3,1)$$
$$Sq^4$$
$$Sq(4)$$
$$Sq^4 Sq^1$$
$$Sq(5) + Sq(2,1)$$
$$Sq^4 Sq^2$$
$$Sq(6) + Sq(3,1)$$
$$+\ Sq(0,2)$$
$$Sq^5 Sq^2$$
$$Sq(7) + Sq(1,2)$$
$$Sq^4 Sq^2 Sq^1$$
$$Sq(7) + Sq(4,1)$$
$$+\ Sq(1,2) + Sq(0,0,1)$$
$$Sq^5 Sq^2 Sq^1$$
$$Sq(5,1) + Sq(1,0,1)$$
$$Sq^9 + Sq^8 Sq^1 + Sq^7 Sq^2$$
$$+\ Sq^6 Sq^2 Sq^1$$
$$Sq(6,1) + Sq(2,0,1)$$
$$+\ Sq(0,3)$$
$$Sq^9 Sq^1 + Sq^7 Sq^2 Sq^1$$
$$Sq(7,1) + Sq(3,0,1)$$
$$+\ Sq(1,3)$$
$$Sq^6 + Sq^5 Sq^1$$
$$Sq(6) + Sq(3,1)$$
$$Sq^6 Sq^1$$
$$Sq(7) + Sq(4,1)$$
$$Sq^6 Sq^2$$
$$Sq(5,1) + Sq(2,2)$$
$$Sq^6 Sq^3$$
$$Sq(6,1) + Sq(3,2)$$
$$+\ Sq(0,3)$$
$$Sq^6 Sq^2 Sq^1$$
$$Sq(3,2) + Sq(2,0,1) + Sq(0,3)$$
$$Sq^6 Sq^3 Sq^1$$
$$Sq(7,1) + Sq(3,0,1)$$
$$+\ Sq(0,1,1)$$
$$Sq^9 Sq^2 + Sq^8 Sq^3$$
$$+\ Sq^7 Sq^3 Sq^1$$
$$Sq(2,3) + Sq(1,1,1)$$
$$Sq^9 Sq^2 Sq^1 + Sq^8 Sq^3 Sq^1$$
$$Sq(3,3) + Sq(2,1,1)$$
$$Sq^7$$
$$Sq(7)$$
$$Sq^7 Sq^1$$
$$Sq(5,1)$$
$$Sq^7 Sq^2$$
$$Sq(3,2)$$
$$Sq^7 Sq^3$$
$$Sq(7,1) + Sq(1,3)$$
$$Sq^7 Sq^2 Sq^1$$
$$Sq(3,0,1) + Sq(1,3)$$
$$Sq^7 Sq^3 Sq^1$$
$$Sq(1,1,1)$$
$$Sq^9 Sq^3$$
$$Sq(3,3)$$
$$Sq^9 Sq^3 Sq^1$$
$$Sq(3,1,1)$$
$$Sq^{10} + Sq^9 Sq^1$$
$$+\ Sq^8 Sq^2 + Sq^7 Sq^2 Sq^1$$
$$Sq(4,2) + Sq(3,0,1)$$
$$+\ Sq(1,3)$$
$$Sq^{10} Sq^1 + Sq^8 Sq^2 Sq^1$$
$$Sq(5,2) + Sq(4,0,1)$$
$$+\ Sq(2,3)$$
$$Sq^{10} Sq^2 + Sq^8 Sq^3 Sq^1$$
$$Sq(6,2) + Sq(5,0,1)$$
$$+\ Sq(2,1,1)$$
$$Sq^{10} Sq^3 + Sq^9 Sq^4$$
$$+\ Sq^8 Sq^4 Sq^1$$
$$Sq(7,2) + Sq(6,0,1)$$
$$+\ Sq(3,1,1) + Sq(0,2,1)$$
$$Sq^{10} Sq^2 Sq^1$$
$$Sq(7,2) + Sq(6,0,1) + Sq(4,3)$$
$$Sq^{10} Sq^3 Sq^1 + Sq^9 Sq^4 Sq^1$$
$$Sq(5,3) + Sq(4,1,1)$$
$$+\ Sq(1,2,1)$$
$$Sq^{10} Sq^5 + Sq^{10} Sq^4 Sq^1$$
$$Sq(6,3) + Sq(5,1,1)$$
$$+\ Sq(2,2,1)$$
$$Sq^{10} Sq^5 Sq^1$$
$$Sq(7,3) + Sq(6,1,1)$$
$$+\ Sq(3,2,1) + Sq(0,3,1)$$
$$Sq^{11} + Sq^9 Sq^2$$
$$Sq(5,2)$$
$$Sq^{11} Sq^1 + Sq^9 Sq^2 Sq^1$$
$$Sq(5,0,1) + Sq(3,3)$$
$$Sq^{11} Sq^2 + Sq^9 Sq^3 Sq^1$$
$$Sq(7,2) + Sq(3,1,1)$$
$$Sq^{11} Sq^3 + Sq^9 Sq^4 Sq^1$$
$$Sq(7,0,1) + Sq(1,2,1)$$
$$Sq^{11} Sq^2 Sq^1$$
$$Sq(7,0,1) + Sq(5,3)$$
$$Sq^{11} Sq^3 Sq^1$$
$$Sq(5,1,1)$$
$$Sq^{11} Sq^5 + Sq^{11} Sq^4 Sq^1$$
$$Sq(7,3) + Sq(3,2,1)$$
$$Sq^{11} Sq^5 Sq^1$$
$$Sq(7,1,1) + Sq(1,3,1)$$
$$Sq^{13} + Sq^{12} Sq^1$$
$$+\ Sq^{10} Sq^3$$
$$Sq(7,2) + Sq(4,3)$$
$$Sq^{13} Sq^1 + Sq^{10} Sq^3 Sq^1$$
$$Sq(7,0,1) + Sq(4,1,1)$$
$$Sq^{13} Sq^2 + Sq^{12} Sq^3$$
$$Sq(6,3)$$
$$Sq^{13} Sq^3 + Sq^{10} Sq^5 Sq^1$$
$$Sq(6,1,1) + Sq(3,2,1)$$
$$+\ Sq(0,3,1)$$
$$Sq^{13} Sq^2 Sq^1 + Sq^{12} Sq^3 Sq^1$$
$$Sq(7,3) + Sq(6,1,1)$$
$$Sq^{13} Sq^3 Sq^1$$
$$Sq(7,1,1)$$
$$Sq^{13} Sq^5 + Sq^{13} Sq^4 Sq^1$$
$$+\ Sq^{12} Sq^5 Sq^1$$
$$Sq(2,3,1)$$
$$Sq^{13} Sq^5 Sq^1$$
$$Sq(3,3,1)$$
$$Sq^{17} +\ Sq^{16} Sq^1$$
$$+\ Sq^{15} Sq^2 +\ Sq^{14} Sq^2 Sq^1$$
$$+\ Sq^{12} Sq^5 +\ Sq^{12} Sq^4 Sq^1$$
$$Sq(7,1,1) +\ Sq(4,2,1)$$
$$Sq^{17} Sq^1 +\ Sq^{15} Sq^2 Sq^1$$
$$+\ Sq^{12} Sq^5 Sq^1$$
$$Sq(5,2,1) +\ Sq(2,3,1)$$
$$Sq^{17} Sq^2 +\ Sq^{16} Sq^3$$
$$+\ Sq^{15} Sq^3 Sq^1 +\ Sq^{14} Sq^5$$
$$+\ Sq^{14} Sq^4 Sq^1$$
$$Sq(6,2,1)$$
$$Sq^{17} Sq^3 +\ Sq^{15} Sq^5$$
$$+\ Sq^{15} Sq^4 Sq^1$$
$$Sq(7,2,1)$$
$$Sq^{17} Sq^2 Sq^1 +\ Sq^{16} Sq^3 Sq^1$$
$$+\ Sq^{14} Sq^5 Sq^1$$
$$Sq(7,2,1) +\ Sq(4,3,1)$$
$$Sq^{17} Sq^3 Sq^1 +\ Sq^{15} Sq^5 Sq^1$$
$$Sq(5,3,1)$$
$$Sq^{17} Sq^5 +\ Sq^{17} Sq^4 Sq^1$$
$$+\ Sq^{16} Sq^5 Sq^1$$
$$Sq(6,3,1)$$
$$Sq^{17} Sq^5 Sq^1$$
$$Sq(7,3,1)$$ | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 1, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.998094916343689, "perplexity": 682.1291696582695}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-21/segments/1652662587158.57/warc/CC-MAIN-20220525120449-20220525150449-00621.warc.gz"} |
https://habr.com/en/hub/refactoring/all/ | • ## The Anatomy of LuaJIT Tables and What’s Special About Them
I don't know about you, but I really like to get inside all sorts of systems. In this article, I’m going to tell you about the internals of Lua tables and special considerations for their use. Lua is my primary professional programming language, and if one wants to write good code, one needs at least to peek behind the curtain. If you are curious, follow me.
• ## Let's help QueryProvider deal with interpolated strings
• Translation
### Specifics of QueryProvider
QueryProvider can’t deal with this:
var result = _context.Humans
.Select(x => \$"Name: {x.Name} Age: {x.Age}")
.Where(x => x != "")
.ToList();
It can’t deal with any sentence using an interpolated string, but it’ll easily deal with this:
var result = _context.Humans
.Select(x => "Name " + x.Name + " Age " + x.Age)
.Where(x => x != "")
.ToList();
The most painful thing is to fix bugs after turning on ClientEvaluation (exception for client-side calculation), since all Automapper profiles should be strictly analyzed for interpolation. Let’s find out what’s what and propose our solution to the problem. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.15467128157615662, "perplexity": 3714.836143700807}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-29/segments/1593655887046.62/warc/CC-MAIN-20200705055259-20200705085259-00386.warc.gz"} |
https://fr.arxiv.org/list/astro-ph.SR/1009 | # Solar and Stellar Astrophysics
## Authors and titles for astro-ph.SR in Sep 2010
[ total of 381 entries: 1-25 | 26-50 | 51-75 | 76-100 | ... | 376-381 ]
[ showing 25 entries per page: fewer | more | all ]
[1]
Title: Detailed Numerical Simulations on the Formation of Pillars around HII-regions
Comments: 15 pages, 12 figures, accepted for publication in ApJ
Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Astrophysics of Galaxies (astro-ph.GA)
[2]
Title: Nitrogen Enrichment in Atmospheres of A- and F- Type Supergiants
Subjects: Solar and Stellar Astrophysics (astro-ph.SR)
[3]
Title: Side-entrainment in a jet embedded in a sidewind
Comments: 8 pages, 12 figures, 1 table, accepted for publication in ApJ
Subjects: Solar and Stellar Astrophysics (astro-ph.SR)
[4]
Title: Cluster mass dependent truncation of the upper IMF: evidence from observations and simulations
Authors: C. Clarke, Th. Maschberger (Institute of Astronomy, Cambridge)
Comments: 8 pages, 4 figures; To appear in "UP: Have Observations Revealed a Variable Upper End of the Initial Mass Function?", Astronomical Society of the Pacific Conference Series
Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
[5]
Title: Observations of Faint Eclipsing Cataclysmic Variables
Journal-ref: New Astronomy,, Volume 15, Issue 5, p. 476-482 (2010)
Subjects: Solar and Stellar Astrophysics (astro-ph.SR)
[6]
Title: On the interpretation of echelle diagrams for solar-like oscillations. Effect of centrifugal distortion
Comments: 10 pages,5 figures, accepted for publication in ApJ; this http URL
Journal-ref: ApJ 721 537 (2010)
Subjects: Solar and Stellar Astrophysics (astro-ph.SR)
[7]
Title: Derivation of the Lattice Boltzmann Model for Relativistic Hydrodynamics
Journal-ref: Phys.Rev.D82:105008,2010
Subjects: Solar and Stellar Astrophysics (astro-ph.SR); High Energy Physics - Phenomenology (hep-ph)
[8]
Title: Optical spectroscopy of DPVs and the case of LP Ara
Comments: To be published in the proceedings book of the IAUS 272, Cambridge University Press. Editors C. Neiner, G. Wade, G. Meynet and G. Peters
Subjects: Solar and Stellar Astrophysics (astro-ph.SR)
[9]
Title: A Common Envelope Binary Star Origin of Long Gamma-ray Bursts
Comments: 6 pages, no figures, accepted by MNRAS
Subjects: Solar and Stellar Astrophysics (astro-ph.SR)
[10]
Title: Radiative emission of solar features in the Ca II K line: comparison of measurements and models
Comments: 14 pages, 18 figures, accepted by A&A
Subjects: Solar and Stellar Astrophysics (astro-ph.SR)
[11]
Title: Forming the first planetary systems: debris around Galactic thick disc stars
Comments: accepted by MNRAS Letters; 5 pages, 4 figures
Subjects: Solar and Stellar Astrophysics (astro-ph.SR)
[12]
Title: Collisional formation of very massive stars in dense clusters
Comments: 8 pages, accepted to MNRAS
Subjects: Solar and Stellar Astrophysics (astro-ph.SR)
[13]
Title: Pulsar current revisited
Subjects: Solar and Stellar Astrophysics (astro-ph.SR)
[14]
Title: Properties, evolution and morpho-kinematical modelling of the very fast nova V2672 Oph (Nova Oph 2009), a clone of U Sco
Subjects: Solar and Stellar Astrophysics (astro-ph.SR)
[15]
Title: Correlations Between Planetary Microlensing Parameters
Comments: 14 pages, 4 figures, 1 table; 2010 ApJ published
Subjects: Solar and Stellar Astrophysics (astro-ph.SR)
[16]
Title: OGLE-2009-BLG-092/MOA-2009-BLG-137: A Dramatic Repeating Event With the Second Perturbation Predicted by Real-Time Analysis
Comments: 18 pages, 5 figures, 1 table
Subjects: Solar and Stellar Astrophysics (astro-ph.SR)
[17]
Title: OGLE-2005-BLG-153: Microlensing Discovery and Characterization of A Very Low Mass Binary
Comments: 6 pages, 3 figures, 1 table
Subjects: Solar and Stellar Astrophysics (astro-ph.SR)
[18]
Title: OB-stars as extreme condition test beds
Comments: To be published in the proceedings book of the IAUS 272, Cambridge University Press. Editors C. Neiner, G. Wade, G. Meynet and G. Peters
Subjects: Solar and Stellar Astrophysics (astro-ph.SR)
[19]
Title: Effect of NLTE model atmospheres on photometric amplitudes and phases of early B-type pulsating stars
Comments: 13 pages, 2 tables, 17 figues submitted to A&A
Subjects: Solar and Stellar Astrophysics (astro-ph.SR)
[20]
Title: The Formation of a Magnetic Channel by the Emergence of Current-carrying Magnetic Fields
Comments: 11 figures, accepted for Astrophysical journal
Subjects: Solar and Stellar Astrophysics (astro-ph.SR)
[21]
Title: Pre-Main Sequence stars in the star forming complex Sh 2-284
Comments: accepted for publication in MNRAS
Subjects: Solar and Stellar Astrophysics (astro-ph.SR)
[22]
Title: Outflows and mass accretion in collapsing dense cores with misaligned rotation axis and magnetic field
Comments: Accepted for publication in MNRAS letters, 6 pages 4 figures
Subjects: Solar and Stellar Astrophysics (astro-ph.SR)
[23]
Title: An Analytic Technique for Constraining the Dynamical Origins of Multiple Star Systems Containing Merger Products
Comments: 17 pages, 3 figures, accepted for publication in MNRAS; Corrected typos, updated references and added a reference to the Discussion Section
Subjects: Solar and Stellar Astrophysics (astro-ph.SR)
[24]
Title: The Optical Gravitational Lensing Experiment. The OGLE-III Catalog of Variable Stars. IX. RR Lyrae Stars in the Small Magellanic Cloud | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8482798337936401, "perplexity": 13529.856790157131}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-43/segments/1634323585653.49/warc/CC-MAIN-20211023064718-20211023094718-00106.warc.gz"} |
http://fprimex.com/coding/xppaut.html | XPPAUT¶
Download
This program is a port of XPPAUT by Dr. Bard Ermentrout. I worked on it from the summer of 2003 to the spring of 2005 as a part of my masters thesis. Note that compilation requires wxWidgets 2.6.3. More information is contained in the README.txt and INSTALL.txt. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.46860405802726746, "perplexity": 1944.947863991705}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-05/segments/1579250595282.35/warc/CC-MAIN-20200119205448-20200119233448-00426.warc.gz"} |
http://www.gradesaver.com/textbooks/math/algebra/intermediate-algebra-6th-edition/chapter-7-section-7-2-rational-exponents-exercise-set-page-424/24 | ## Intermediate Algebra (6th Edition)
$2(\sqrt[5] (x)^{3})$
We know that $a^{\frac{m}{n}}=\sqrt[n] (a^{m})$ (where m and n are positive integers greater than 1 with $\frac{m}{n}$ in simplest form and $\sqrt[n] a$ is a real number). Therefore, $2x^{\frac{3}{5}}=2(\sqrt[5] (x)^{3})$. Because the 2 and the x are not in parentheses, we only apply the exponent to the x. In this case, we are multiplying $\sqrt[5] (x)^{3}$ by 2. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.6981003284454346, "perplexity": 127.69153393945095}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-13/segments/1490218189771.94/warc/CC-MAIN-20170322212949-00368-ip-10-233-31-227.ec2.internal.warc.gz"} |
https://nukephysik101.wordpress.com/tag/coordinate/ | ## Laplacian in spherical coordinate
the Momentum operator in spherical coordinate
$\nabla^2 = \frac {1}{r^2}\frac {\partial } { \partial r} \left ( r^2 \frac {\partial} {\partial r} \right ) - \frac {1}{r^2} L^2$
where L is the Reduced angular momentum operator. the minus sign is very important for giving a correct sign. the original angular momentum operator J is related by:
$J=\hbar^2 L$
by compare the Laplacian in spherical coordinate, the L is
$L^2 = - \frac {1}{sin(\theta)} \frac {\partial}{\partial \theta} \left( sin(\theta) \frac {\partial}{\partial \theta} \right ) - \frac {1}{sin(\theta)} \frac{\partial^2} {\partial \phi ^2}$
But this complicated form is rather useless, expect you are mathematic madman.
we can start from classical mechanic
$\vec{L} = \vec {r} \times \vec{p}$
$L_x = y \frac {\partial} {\partial z} - z \frac {\partial}{\partial y }$
$L_y = z \frac {\partial} {\partial x} - x \frac {\partial}{\partial z }$
$L_z = x \frac {\partial} {\partial y} - y \frac {\partial}{\partial x }$
with the change of coordinate
$\begin {pmatrix} x \\ y \\ z \end{pmatrix} = \begin {pmatrix} r sin(\theta) cos(\phi) \\ r sin(\theta) sin(\phi) \\ r cos(\theta) \end{pmatrix}$
and the Jacobian Matrix $M_J$, which is used for related the derivatives.
since
$\frac {\partial}{\partial x} = \frac {\partial r}{\partial x} \frac {\partial} {\partial r} +\frac {\partial \theta}{\partial x} \frac {\partial} {\partial \theta}+\frac {\partial \phi}{\partial x} \frac {\partial} {\partial \phi}$
$\frac {\partial}{\partial y} = \frac {\partial r}{\partial y} \frac {\partial} {\partial r} +\frac {\partial \theta}{\partial y} \frac {\partial} {\partial \theta}+\frac {\partial \phi}{\partial y} \frac {\partial} {\partial \phi}$
$\frac {\partial}{\partial z} = \frac {\partial r}{\partial z} \frac {\partial} {\partial r} +\frac {\partial \theta}{\partial z} \frac {\partial} {\partial \theta}+\frac {\partial \phi}{\partial z} \frac {\partial} {\partial \phi}$
which can be simplify
$\nabla_{(x,y,z)} = M_J^T \nabla_{(r, \theta, \phi )}$
$M_J = \frac {\partial ( r, \theta, \phi) }{\partial (x,y,z)}$
$M_J^{\mu\nu} = \frac {\partial \mu}{\partial \nu}$
then, we have
$L_x = i sin(\phi) \frac {\partial }{\partial \theta} +i cot(\theta) cos(\phi) \frac { \partial }{\partial \phi}$
$L_y =-i cos(\phi) \frac {\partial }{\partial \theta} + i cot(\theta) sin(\phi) \frac { \partial }{\partial \phi}$
$L_z = - i \frac {\partial }{\partial \phi}$
However, even we have the functional form, it is still not good. we need the ladder operator
$L_+ = L_x + i L_y = Exp(i \phi) \left( \frac {\partial }{\partial \theta} + i cot(\theta) \frac { \partial }{\partial \phi} \right)$
$L_- = L_x - i L_y = Exp(-i \phi) \left( \frac {\partial }{\partial \theta} - i cot(\theta) \frac { \partial }{\partial \phi} \right)$
notice that
$L_+^\dagger = L_-$
so, just replacing $i \rightarrow -i$.
when we looking for the Maximum state of the spherical Harmonic $Y_{max}(\theta, \phi)$
$L_+ Y_{max}(\theta,\phi) = 0 *)$
use the separable variable assumption.
$Y_{max}(\theta, \phi) = \Theta \Phi$
$L_+ \Theta \Phi = 0 = - Exp(i \phi) \left( \frac {d\Theta}{d \theta} \Phi + i cot(\theta) \frac { d\Phi}{d\phi} \right) \Theta$
$\frac {tan(\theta)}{\Theta} \frac { d \Theta} {d \Theta } = - \frac {i}{\Phi} \frac {d \Phi} {d \phi} = m$
the solution is
$Y_{max}(\theta,\phi) = sin^m(\theta) Exp(i m \phi )$
$L^2 Y_{max}(\theta, \phi) = m(m+1) Y_{max}(\theta,\phi)$
an application on Hydrogen wave function is here.
## Hydrogen Atom (Bohr Model)
OK, here is a little off track. But that is what i were learning and learned. like to share in here. and understand the concept of hydrogen is very helpful to understand the nuclear, because many ideas in nuclear physics are borrow from it, like “shell”.
The interesting thing is about the energy level of Hydrogen atom. the most simple atomic system. it only contains a proton at the center, um.. almost center, and an electron moving around. well, this is the “picture”. the fact is, there is no “trajectory” or locus for the electron, so technically, it is hard to say it is moving!
why i suddenly do that is because, many text books said it is easy to calculate the energy level and spectrum for it. Moreover, many famous physicists said it is easy. like Feynman, Dirac, Landau, Pauli, etc… OK, lets check how easy it is.
anyway, we follow the usual say in every text book. we put the Coulomb potential in the Schrödinger equation, change the coordinate to spherical. that is better and easy for calculation because the coulomb potential is spherical symmetric. by that mean, the momentum operator (any one don’t know what is OPERATOR, the simplest explanation is : it is a function of function.) automatically separated into 2 parts : radial and angular part. The angular part can be so simple that it is the Spherical harmonic.
Thus the solution of the “wave function” of the electron, which is also the probability distribution of the electron location, contains 2 parts as well. the radial part is not so trivial, but the angular part is so easy. and it is just $Y(l,m)$.
if we denote the angular momentum as L, and the z component of it is Lz, thus we have,
$L^2 Y(l,m) = l(l+1) \hbar^2 Y(l,m)$
$L_z Y(l,m) = m \hbar Y(l,m)$
as every quadratic operator, there are “ladder” operator for “up” and “down”.
$L_\pm Y(l,m) =\hbar \sqrt{l(l+1) - m(m\pm 1)} Y(l,m \pm 1)$
which means, the UP operator is increase the z-component by 1, the constant there does not brother us.
it is truly easy to find out the exact form of the $Y(l,m)$ by using the ladder operator. as we know, The z component of the a VECTOR must have some maximum. so, there exist an $Y(l,m)$ such that
$L_+ Y(l,m) =0$
since there is no more higher z-component.
by solve this equation, we can find out the exact form of $Y(l,m)$ and sub this in to L2, we can know$Max(m) = l$. and apply the DOWN operator, we can fins out all $Y(l,m)$, and the normalization constant is easy to find by the normalization condition in spherical coordinate, the normalization factor is $sin(\theta)$, instead of 1 in rectangular coordinate.
$\int_0^\pi \int_0^{2 \pi} Y^*(l',m') Y(l,m) sin(\theta) d\theta d \psi = \delta_{l' l} \delta_{m' m}$
more on here | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 41, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9812853932380676, "perplexity": 597.7386412302321}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-17/segments/1492917123270.78/warc/CC-MAIN-20170423031203-00229-ip-10-145-167-34.ec2.internal.warc.gz"} |
https://www.springerprofessional.de/foundations-for-innovative-application-of-airborne-radars/19033084 | main-content
Über dieses Buch
This book discusses methods for measuring the water surface backscattering signature and estimating the near-surface wind vector over water using airborne radars, in addition to their standard application. Airborne FMCW demonstrator system, Doppler navigation system, airborne weather radar, airborne radar altimeter, and airborne precipitation radar are analyzed in order to be used for that purpose. The radars functionality is enhanced for their operation in a scatterometer mode. A circle flight and/or a rectilinear flight of an aircraft over the water surface is considered depending on the radar design features to perform measurements of the azimuth normalized radar cross section curve of the water surface and/or the near-surface wind speed and direction. Flight recommendations to perform measurements along with algorithms for measuring the water surface backscattering signature and for retrieval of the wind speed and direction over water are presented.
Inhaltsverzeichnis
Chapter 1. Introduction
Abstract
Satellite remote sensing has demonstrated its potential to provide measurements of weather conditions on a global scale as well as airborne remote sensing on a local scale. Near-surface wind measurements over the sea are very important for operational oceanography, as well as for meteorology and navigation. Wind and wave measurements by those remote sensing instruments are based on features of microwave backscattering from the water surface. To study the microwave backscattering signature of the water surface from aircraft, an airborne scatterometer is used. The measurements are typically performed at either a circle track flight using a fixed fan-beam antenna or a rectilinear track flight using a rotating antenna. For such an airborne measurement of winds, antennas with comparatively narrow beams are commonly used. Unfortunately, a microwave narrow-beam antenna has considerable size at Ku-, X-, and C-bands that makes its placing on an aircraft difficult, especially on a seaplane or an amphibious aircraft. Therefore, a better way needs to be found. At least two options can be proposed. The first option is to apply airborne scatterometers with wide-beam antennas as it can lead to reduction of the antenna size. The second option is to use modified conventional navigation instruments of the aircraft in a scatterometer mode, which seems more preferable.
Alexey Nekrasov
Chapter 2. Water-Surface Backscattering and Wind Retrieval
Abstract
Research on microwave backscatter by the water surface has shown that the use of a scatterometer also allows an estimation of the near-surface wind vector because the Normalized radar cross section (NRCS) of water surface depends on wind speed and direction. Based on experimental data and scattering theory, a significant number of empirical and theoretical backscatter models and algorithms for estimation of near-surface wind vector over water from satellite and airplane have been developed. To retrieve the wind vector from NRCS measurements, a relationship between NRCS and near-surface wind, called the “geophysical model function” is used. A scatterometer having an antenna with an inclined beam allows measuring NRCS azimuth curve of a water surface and provides retrieval of both wind speed and wind direction over water. A scatterometer equipped with a nadir-looking antenna allows measuring nadir NRCS and estimating sea surface wind speed but provides no information on the wind direction.
Alexey Nekrasov
Chapter 3. FM-CW Demonstrator System as an Instrument for Measuring Sea-Surface Backscattering Signature and Wind
Abstract
In the field of airborne earth observation, there is growing interest in small, cost-effective radar systems. Such radar systems should consume little power and be small enough to be mounted on light, possibly even unmanned, aircraft. FM-CW radar systems are generally compact, relatively cheap, and they consume little power. Consequently, FM-CW radar technology seems to be of interest to civil airborne earth observation, particularly in combination with high resolution SAR techniques.
Alexey Nekrasov
Chapter 4. Doppler Navigation System Application for Measuring Backscattering Signature and Wind Over Water
Abstract
DNS is a self-contained radar system that uses the Doppler effect (Doppler radar) for measuring ground speed and drift angle of aircraft and performs its dead-reckoning navigation (Sosnovskiy and Khaymovich 1987).
Alexey Nekrasov
Chapter 5. Measuring Water-Surface Backscattering Signature and Wind by Means of Airborne Weather Radar
Abstract
Measuring Water Surface Backscattering Signature and Wind by Means of Airborne Weather Radar: Airborne weather radar (AWR) is the type of radar equipment mounted on an aircraft for purposes of weather observation and avoidance, aircraft position finding relative to landmarks, and drift angle measurement. AWRs or multimode radars with a weather mode are usually nose mounted. The AWR antenna, in the ground-mapping mode, has a large cosecant-squared elevation beam where the horizontal dimension is narrow while the other is relatively broad, and it sweeps in an azimuth sector of up to ± 100°. Therefore, those features can be used for AWR enhancement to measure the water-surface backscattering signature and wind vector over water when it operates in a scatterometer mode. The analysis of AWR has shown that the radar employed in the ground-mapping mode as a scatterometer can be used for remote measuring of the sea surface backscattering signature at a circular flight along with recovering the wind speed and direction over the water surface from NRCS azimuth curves obtained as well as for measuring wind vector during a rectilinear flight in addition to its typical meteorological and navigation application.
Alexey Nekrasov
Chapter 6. Water-Surface Wind Retrieval Using Airborne Radar Altimeter
Abstract
Radar altimeters are frequently used by aircraft. The primary function of the Airborne radar altimeter (ARA) is to provide terrain clearance or altitude with respect to the ground level directly beneath the airplane or helicopter. The ARA may also provide a vertical rate of climb or descent and selectable low altitude warning. Typical scatterometer wind measurements are commonly performed using antennas with comparatively narrow beams. As the ARA has a wide-beam antenna, the beam sharpening technologies should be used to apply the ARA for wind vector measurement. For that prepuce, Doppler discrimination along with range discrimination have been employed. The wind retrieval algorithms for several particular beam geometries are presented. The study has shown that wind vector over sea can be measured by means of the ARA employed as a nadir-looking wide-beam short-pulse scatterometer in conjunction with Doppler filtering. The measuring instrument should be equipped with two additional Doppler filters (a fore-Doppler filter and an aft-Doppler filter) to provide for spatial selection under the wind measurements.
Alexey Nekrasov
Abstract
APR-2 is an airborne, dual-frequency (Ku- and Ka-band), dual-polarization Doppler rain profiling radar. Its antenna scans in the ±25° cross-track elevation range allowing the radar to measure atmospheric precipitation and sea surface NRCS. The wind measuring algorithm has been proposed and investigated with the help of simulations. The study has shown that airborne radar instrument for measurement geometry similar to the APR-2 geometry and operating in a scatterometer mode can be applied to remote measurement of sea surface wind speed and direction at near-nadir incidence angles based on the measuring algorithm developed in case of precipitation absence. As azimuth water surface slope variance has been assumed to be elliptical, wind direction can be estimated, unfortunately, only with an ambiguity of 180°. It means that in principle the APR-2 also can be applied to wind retrieval over water surface during a rectilinear flight in addition to its typical meteorological application.
Alexey Nekrasov
Backmatter
Weitere Informationen | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8392343521118164, "perplexity": 3330.9702078934}, "config": {"markdown_headings": false, "markdown_code": false, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 5, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-17/segments/1618038469494.59/warc/CC-MAIN-20210418073623-20210418103623-00261.warc.gz"} |
http://programminghistorian.org/lessons/linux-installation | 2012-07-17
Setting up an Integrated Development Environment for Python (Linux)
Reviewed by Jim Clifford, Amanda Morton, and Miriam Posner
Thanks to John Fink for providing the basis of this section. These instructions are for Ubuntu 12.04 LTS, but should work for any apt based system such as Debian, or Linux Mint, provided you have sudo installed.
It is always important to make sure you have regular and recent backups of your computer. This is just good advice for life, and is not limited to times when you are engaged in programming.
Install Python v. 2
1. Open a terminal (Dash Home, then type Terminal, then click on the Terminal icon).
2. Now type: sudo apt-get install python2.7
3. Enter your password, and then type Y to finish the install. Note that you probably have Python 2.7 installed already, so don’t be alarmed if Ubuntu tells you that.
Create a directory
You will keep your Python programs in this directory. It can be anywhere you like, but it is probably best to put it in your home folder. Something like this in your open terminal window should do the trick:
cd ~
mkdir programming-historian
Install Komodo Edit
Komodo Edit is a free and open source code editor, but you have many other text editing options if you prefer. You can download Komodo Edit at the Komoto Edit Website. Once you’ve downloaded it, open it with Ubuntu’s package manager, extract it to your home directory, and follow the installation instructions. If you are following along with these instructions and have installed Komodo Edit, open the home folder, go to the Komodo-Edit-7/bin directory, and click on komodo. You can also right click on the Komodo icon in your launcher and click “Lock to Launcher” to have Komodo saved permanently to your launcher bar.
Make a “Run Python” Command in Komodo Edit
1. In Komodo Edit, click the gear icon under Toolbox and select New Command.
2. In the top field type “Run Python File
3. In the Command field, type: %(python) %F Then hit the OK button at the bottom of the Add Command window.
Step 2 – “Hello World” in Python
It is traditional to begin programming in a new language by trying to create a program that says “hello world” and terminates.
Python is a good programming language for beginners because it is very high-level. It is possible, in other words, to write short programs that accomplish a lot. The shorter the program, the more likely it is for the whole thing to fit on one screen, and the easier it is to keep track of all of it in your mind.
Python is an ‘interpreted’ programming language. This means that there is a special computer program (known as an interpreter) that knows how to follow instructions written in that language. One way to use the interpreter is to store all of your instructions in a file, and then run the interpreter on the file. A file that contains programming language instructions is known as a program. The interpreter will execute each of the instructions that you gave it in your program and then stop. Let’s try this.
In your text editor, create a new file, enter the following two-line program and save it to your programming-historian directory as hello-world.py
# hello-world.py
print('hello world')
Your chosen text editor should have a “Run” button that will allow you to execute your program. If all went well, it should look something like this (Example as seen in Komodo Edit.)
Interacting with a Python shell
Another way to interact with an interpreter is to use what is known as a shell. You can type in a statement and press the Enter key, and the shell will respond to your command. Using a shell is a great way to test statements to make sure that they do what you think they should.
You can run a Python shell by launching the “terminal”. For Linux, go to Applications-> Accessories -> Terminaland do the same. At the Python shell prompt, type
python
This will open up the Python prompt, meaning that you can now use Python commands in the shell. Now type
print('hello world')
and press Enter. The computer will respond with
hello world
When we want to represent an interaction with the shell, we will use -> to indicate the shell’s response to your command, as shown below:
print('hello world')
-> hello world
On your screen, it will look more like this:
Now that you and your computer are up and running, we can move onto some more interesting tasks. If you are working through the Python lessons in order, we suggest you next try ‘Understanding Web Pages and HTML | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.17859475314617157, "perplexity": 1817.0209117309907}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-13/segments/1490218186895.51/warc/CC-MAIN-20170322212946-00033-ip-10-233-31-227.ec2.internal.warc.gz"} |
https://repository.lboro.ac.uk/articles/Ising_model_an_analysis_from_opinions_to_neuronal_states/9411113 | ## Ising model – an analysis, from opinions to neuronal states
2017-03-29T14:04:15Z (GMT) by
Here we have developed a mathematical model of a random neuron network with two types of neurons: inhibitory and excitatory. Every neuron was modelled as a functional cell with three states, parallel to hyperpolarised, neutral and depolarised states in vivo. These either induce a signal or not into their postsynaptic partners. First a system including just one network was simulated numerically using the software developed in Python. Our simulations show that under physiological initial conditions, the neurons in the network all switch off, irrespective of the initial distribution of states. However, with increased inhibitory connections beyond 85%, spontaneous oscillations arise in the system. This raises the question whether there exist pathologies where the increased amount of inhibitory connections leads to uncontrolled neural activity. There has been preliminary evidence elsewhere that this may be the case in autism and down syndrome [1-4]. At the next stage we numerically studied two mutually coupled networks through mean field interactions. We find that via a small range of coupling constants between the networks, pulses of activity in one network are transferred to the other. However, for high enough coupling there appears a very sudden change in behaviour. This leads to both networks oscillating independent of the pulses applied. These uncontrolled oscillations may also be applied to neural pathologies, where unconnected neuronal systems in the brain may interact via their electromagnetic fields. Any mutations or diseases that increase how brain regions interact can induce this pathological activity resonance. Our simulations provided some interesting insight into neuronal behaviour, in particular factors that lead to emergent phenomena in dynamics of neural networks. This can be tied to pathologies, such as autism, Down's syndrome, the synchronisation seen in parkinson's and the desynchronisation seen in epilepsy. The model is very general and also can be applied to describe social network and social pathologies. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.903657078742981, "perplexity": 1432.1715525568866}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-10/segments/1581875146643.49/warc/CC-MAIN-20200227002351-20200227032351-00280.warc.gz"} |
https://rd.springer.com/chapter/10.1007%2F978-3-662-49630-5_14 | # Quantifier Alternation for Infinite Words
• Théo Pierron
• Thomas Place
• Marc Zeitoun
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 9634)
## Abstract
We investigate the expressive power of the quantifier alternation hierarchy of first-order logic over words. This hierarchy includes the classes $$\varSigma _{{i}}$$ (sentences having at most i blocks of quantifiers starting with an $$\exists$$) and $$\mathcal {B}\varSigma _{{i}}$$ (Boolean combinations of $$\varSigma _{{i}}$$ sentences). So far, this expressive power has been effectively characterized for the lower levels only. Recently, a breakthrough was made over finite words, and decidable characterizations were obtained for $$\mathcal {B}\varSigma _{2}$$ and $$\varSigma _{3}$$, by relying on a decision problem called separation, and solving it for $$\varSigma _{2}$$.
The contribution of this paper is a generalization of these results to the setting of infinite words: we solve separation for $$\varSigma _{2}$$ and $$\varSigma _{3}$$, and obtain decidable characterizations of $$\mathcal {B}\varSigma _{2}$$ and $$\varSigma _{3}$$ as consequences.
Regular word languages form a robust class, as they can be defined either by operational, algebraic, or logical means: they are exactly those that can be defined equivalently by finite state machines (operational view), morphisms into finite algebras (algebraic view) and monadic second order (“MSO”) sentences [4, 5, 8, 27] (logical view). To understand the structure of this class in depth, it is natural to classify its languages according to their descriptive complexity. The problem is to determine how complicated a sentence has to be to describe a given input language. This is a decision problem parametrized by a fragment of MSO: given an input language, can it be expressed in the fragment? This problem is called membership (is the language a member of the class defined by the fragment?).
The seminal result in this field is the membership algorithm for first-order logic ($$\text {FO}$$) over finite words, which is arguably the most prominent fragment of MSO. This algorithm was obtained in two steps. McNaughton and Papert [10] observed that the languages definable in $$\text {FO}$$ are exactly the star-free languages: those that may be expressed by a regular expression in which complement is allowed while the Kleene star is disallowed. Furthermore, an earlier result of Schützenberger [23] shows that star-free languages are exactly the ones whose syntactic monoid is aperiodic. The syntactic monoid is a finite algebra that can be computed from any input regular language, and aperiodicity can be formulated as an equation that has to be satisfied by all elements of this algebra. Therefore, Schützenberger’s result makes it possible to decide whether a regular language is star-free (and therefore definable in $$\text {FO}$$ by McNaughton-Papert’s result).
Following this first result, the attention turned to a deeper question: given an $$\text {FO}$$-definable language, find the “simplest” $$\text {FO}$$-sentences that define it. The standard complexity measure for $$\text {FO}$$ sentences is their quantifier alternation, which counts the number of switches between blocks of $$\exists$$ and $$\forall$$ quantifiers. This measure is justified not only because it is intuitively difficult to understand a sentence with many alternations, but also because the nonelementary complexity of standard problems for $$\text {FO}$$ [25] (e.g, satisfiability) is tied to quantifier alternation. In summary, we classify $$\text {FO}$$ definable languages by counting the number of quantifier alternations needed to define them and we want to be able to decide the level of a given language (which amounts to solving membership for each level).
This leads to define the following fragments of $$\text {FO}$$: an $$\text {FO}$$ sentence is $$\varSigma _{{i}}$$ if its prenex normal form has at most i blocks of $$\exists$$ or $$\forall$$ quantifiers and starts with a block of existential ones. Note that $$\varSigma _{{i}}$$ is not closed under complement (the negation of a $$\varSigma _{{i}}$$ sentence is called a $$\varPi _{{i}}$$ sentence). A sentence is $$\mathcal {B}\varSigma _{{i}}$$ if it is a Boolean combination of $$\varSigma _{{i}}$$ sentences (cf. figure). Clearly, we have $$\varSigma _{{i}} \subseteq \mathcal {B}\varSigma _{{i}} \subseteq \varSigma _{i+1}$$, and these inclusions are known to be strict [3, 26]: $$\varSigma _{{i}} \subsetneq \mathcal {B}\varSigma _{{i}} \subsetneq \varSigma _{i+1}$$.
Solving membership for levels of this hierarchy is a longstanding open problem. Following Schützenberger’s approach, it was first investigated for languages of finite words. However, the question also makes sense for more complex structures, in particular for the most natural extension: infinite words. Schützenberger’s result was first generalized to infinite words by Perrin [11], and a suitable algebraic framework for languages of infinite words was set up by Wilke [28]. Since a regular language of infinite words is determined by regular languages of finite words, finding a membership algorithm for languages of infinite words does not usually require to start over. Instead these algorithms are obtained by building on top of the algorithms for finite words, adding new arguments, specific to infinite words.
Regarding the hierarchy, membership is easily seen to be decidable for $$\varSigma _{1}$$. For $$\mathcal {B}\varSigma _{1}$$, the classical result of Simon [24] was generalized from finite to infinite words by Perrin and Pin [12]. For finite words, membership to $$\varSigma _{2}$$ is known to be decidable [1, 15], a result lifted to infinite words in [2, 7]. Following these results, the understanding of the hierarchy remained stuck for years until the framework was extended to new and more general problems than membership.
Rather than asking whether a language is definable in a fragment $$\mathcal {F}$$, these problems ask what is the best $$\mathcal {F}$$-definable “approximation” of this language (with respect to specific criteria). The simplest example is $$\mathcal {F}$$-separation, which takes two regular languages as input and asks whether there exists a third language definable in$$\mathcal {F}$$ that contains the first language and is disjoint from the second. Separation is more general than membership: asking whether a regular language is definable in $$\mathcal {F}$$ is the same as asking whether it can be $$\mathcal {F}$$-separated from its (also regular) complement. A consequence is that deciding these more general problems is usually more challenging than deciding membership. However, their investigation in the setting of finite words has also been very rewarding. A good illustration is the transfer result of [18], which states that for all i, decidability of separation for $$\varSigma _{{i}}$$ entails decidability of membership for $$\varSigma _{i+1}$$. Combined with an algorithm for $$\varSigma _{2}$$-separation [18], this proved that $$\varSigma _{3}$$ has decidable membership. This result was strengthened in [16], which shows that $$\varSigma _{3}$$-separation is decidable as well, thus obtaining decidability of membership for $$\varSigma _{4}$$. Finally, in [18], it was shown that $$\mathcal {B}\varSigma _{2}$$ has decidable membership by using a generalization of separation for $$\varSigma _{2}$$ and analyzing an algorithm solving this generalization.
It remained open to know whether it was possible to generalize with the same success this new approach to the setting of infinite words. This is the investigation that we carry out in the paper. More precisely, we rely on the crucial notion of $$\varSigma _{{i}}$$-chains, designed in [18] for presenting and proving membership and separation algorithms for finite words. We generalize this concept to infinite words and successfully use it to prove that the following problems are decidable: $$\varSigma _{2}$$-separation, $$\varSigma _{3}$$-separation, and $$\mathcal {B}\varSigma _{2}$$ membership. This demonstrates that $$\varSigma _{{i}}$$-chains remain a suitable framework for presenting arguments in the setting of infinite words. On the other hand, new issues specific to infinite words arise, for example, we were not able to generalize the transfer result from $$\varSigma _{{i}}$$-separation to $$\varSigma _{i+1}$$-membership (as a consequence, membership for $$\varSigma _{4}$$ remains open). Note also that, for each problem, we pre-compute some information by using the corresponding algorithm designed in [16, 18] for finite words. This means that the involved algorithms from [16, 18] are used as subroutines of our algorithms.
It is worth noting that the decidability of the membership problem for $$\mathcal {B}\varSigma _{2}$$ over infinite words has been obtained independently in [9]. While the algorithm is essentially the same as our own, its proof is completely different.
We now present the problems in depth in Sect. 1, and we solve them in the rest of the paper. A detailed outline is provided at the end of Sect. 1. Due to lack of space, some proofs are postponed to the full version of this paper, see [13].
## 1 Presentation of the Problem
In this section, we first define the quantifier alternation hierarchy of first-order logic. Then, we present the membership problem and the separation problem.
### 1.1 The Quantifier Alternation Hierarchy of First-Order Logic
We fix a finite alphabet A. We denote by $$A^+$$ the set of all finite nonempty words, and by $$A^\infty$$ the set of all infinite words over A. We use the term “word” for “finite word”. We call language (resp. language of infinite words) a subset of $$A^+$$ (resp. of $$A^\infty$$). If u is a word and v is a word (resp. an infinite word), we denote by uv the word (resp. the infinite word) obtained by concatenating u to the left of v. If u is a word, we denote by $$u^\infty$$ the infinite word $$uuuu\cdots$$ obtained as the infinite concatenation of u with itself. If u is a word or an infinite word, we denote by $$\textsf {alph}(u)$$ the alphabet of u, i.e., the set of letters of u.
First-Order Logic. Any word or infinite word can be viewed as a logical structure made of a linearly ordered sequence of positions (finite for words and infinite for infinite words) labeled over alphabet A. In first-order logic “FO”, one can quantify over these positions and use the following predicates.
• for each $$a \in A$$, a unary predicate $$P_a$$ selecting all positions labeled with an a.
• a binary predicate’$$<$$’ interpreted as the (strict) linear order over the positions.
Since any $$\text {FO}$$ sentence may be interpreted both on words and infinite words, each sentence $$\varphi$$ defines two objects: a language $$L_+ = \{w \in A^+ \mid w \models \varphi \}$$ and a language of infinite words $$L_\infty = \{w \in A^\infty \mid w \models \varphi \}$$. For example, the sentence $$\exists x \exists y\ (x < y \wedge P_a(y))$$ defines the language $$A^+a\cup A^+aA^+$$ and the language of infinite words $$A^+aA^\infty$$. Thus, we may associate two classes of objects with $$\text {FO}$$: a class of languages (we speak of $$\text {FO}$$ over words) and a class of languages of infinite words (we speak of $$\text {FO}$$ over infinite words).
Quantifier Alternation. It is usual to classify $$\text {FO}$$ sentences by counting the quantifier alternations inside their prenex normal form. Let $$i \in \mathbb {N}$$, a sentence is said to be $$\varSigma _{i}$$ (resp. $$\varPi _{i}$$) if its prenex normal form has either:
• exactly$$i -1$$ quantifier alternations (i.e., exactly i quantifier blocks) starting with an $$\exists$$ (resp. $$\forall$$), or
• strictly less than $$i -1$$ quantifier alternations (i.e., strictly less than i blocks).
For example, the sentence $$\exists x_1 \forall x_2 \forall x_3 \exists x_4 \ \varphi$$, with $$\varphi$$ quantifier-free, is $$\varSigma _{3}$$. Note that in general, the negation of a $$\varSigma _{{i}}$$ sentence is not a $$\varSigma _{{i}}$$ sentence – it is called a $$\varPi _{{i}}$$ sentence. Hence, it is also usual to define $$\mathcal {B}\varSigma _{{i}}$$ sentences as those that are Boolean combinations of $$\varSigma _{{i}}$$ and $$\varPi _{{i}}$$ sentences.
As for full first-order logic, each level $$\varSigma _{{i}}$$, $$\varPi _{{i}}$$ or $$\mathcal {B}\varSigma _{{i}}$$ defines two classes of objects: a class of languages and a class of languages of infinite words. Therefore, we obtain two hierarchies: a hierarchy of classes of languages and a hierarchy of classes of languages of infinite words, both of which are known to be strict [3, 26].
### 1.2 Decision Problems
Our objective is to investigate the quantifier alternation hierarchy of first-order logic over infinite words. We rely on two decision problems in order to carry out this investigation: the membership problem and the separation problem. The input of these problems are regular languages of finite and infinite words. They are those languages that can be equivalently defined by monadic second-order logic, finite Büchi automata or finite Wilke algebras. We will use Wilke algebras, whose definition is recalled in Sect. 2. Both problems are parametrized by a level in the hierarchy and come therefore in two versions: a ‘language’ one and a ‘language of infinite words ’ one. Let $$\mathcal {F}$$ be a level in the hierarchy.
Membership. The membership problem for level $$\mathcal {F}$$ is as follows:
Separation. The separation problem is more general. Given three languages or three languages of infinite words $$K,L_1,L_2$$, we say that Kseparates$$L_1$$ from $$L_2$$ if $$L_1 \subseteq K \text { and } L_2 \cap K = \emptyset$$. For $$\mathcal {F}$$ a level in the hierarchy, $$L_1$$ is said $$\mathcal {F}$$-separable from $$L_2$$ if there exists an $$\mathcal {F}$$-definable language or language of infinite words that separates $$L_1$$ from $$L_2$$. Note that when $$\mathcal {F}$$ is not closed under complement (e.g., for $$\mathcal {F} = \varSigma _{{i}}$$), the definition is not symmetrical: $$L_1$$ may be $$\mathcal {F}$$-separable from $$L_2$$ while $$L_2$$ is not $$\mathcal {F}$$-separable from $$L_1$$. The separation problem for $$\mathcal {F}$$ is as follows:
An important remark is that membership reduces to separation. A regular language of words or infinite words is definable in $$\mathcal {F}$$ iff it is $$\mathcal {F}$$-separable from its (also regular) complement: separation is a more general problem than membership.
Both problems have been extensively studied in the literature. Indeed, it has been observed that obtaining an algorithm for the membership or separation problem associated to a particular level $$\mathcal {F}$$ usually yields a deep insight on $$\mathcal {F}$$. This is well illustrated by the most famous result of this kind, Schützenberger’s Theorem [10, 23], which yields a membership algorithm for $$\text {FO}$$ over words. The result was later generalized to $$\text {FO}$$ over infinite words by Perrin [11]. These results and the techniques used to obtain them provide not only a way to decide whether a regular language of finite or infinite words is $$\text {FO}$$-definable, but also a generic method for constructing a defining $$\text {FO}$$ sentence, when possible. Since these first results, many efforts have been devoted for obtaining membership and separation algorithms for each level in the hierarchy. An overview of the results is presented in the following table (omitted levels are open in all cases).
Our objective is to bridge the gap between the knownledge for languages and that for languages of infinite words. More precisely, we want to extend the results of [16, 18] to the setting of infinite words, i.e., to obtain membership algorithms for $$\mathcal {B}\varSigma _{2}$$, $$\varSigma _{3}$$ and $$\varSigma _{4}$$ as well as separation algorithms for $$\varSigma _{2}$$ and $$\varSigma _{3}$$. We were able to obtain these algorithms for $$\varSigma _{2}$$, $$\varSigma _{3}$$ and $$\mathcal {B}\varSigma _{2}$$ as stated in the next theorem. Note that the $$\varSigma _{3}$$-membership algorithm follows from its separation algorithm. We leave open the case of $$\varSigma _{4}$$-membership for languages of infinite words.
### Theorem 1
The following properties hold:
1. (a)
the separation problem is decidable for $$\varSigma _{2}$$ over infinite words.
2. (b)
the membership problem is decidable for $$\mathcal {B}\varSigma _{2}$$ over infinite words.
3. (c)
the separation problem is decidable for $$\varSigma _{3}$$ over infinite words.
Our proof of Theorem 1 consists in three algorithms, one for each item in the theorem. An important remark is that each of these three algorithms depends upon an algorithm of [18] or [16] solving the corresponding problem for finite words:
• We present all algorithms in a specific framework which is adapted from the one used in [18]. In particular, we reuse the key notion of “$$\varSigma _{{i}}$$-chain ” (generalized to infinite words in a straightforward way).
• We actually reuse the algorithms for finite words of [16, 18] as subprocedures in our algorithms for languages of infinite words.
The remainder of the paper is devoted to proving Theorem 1. In Sect. 2, we recall classical notions required for our definitions and proofs: the algebraic definition of regular languages of infinite words and logical preorders. In Sect. 3, we present the general framework that we use. In particular, we introduce a notion that will be at the core of all our algorithms: “$$\varSigma _{{i}}$$-chains ” (which are adapted and reused from [18]). We then devote a section to each algorithm: Sect. 4 to $$\varSigma _{2}$$-separation, Sect. 5 to $$\mathcal {B}\varSigma _{2}$$-membership and Sect. 6 to $$\varSigma _{3}$$-separation.
## 2 Preliminaries
We recall some classical notions that we will need. First, we present the definition of regular languages of infinite words in terms of Wilke algebras. Then, we define the logical preorders that one may associate to each level $$\varSigma _{{i}}$$ in the hierarchy.
### 2.1 Semigroups and Wilke Algebras
We briefly recall the definition of regular languages and languages of infinite words in terms of semigroups and Wilke algebras. For details, see [12].
Semigroups. A semigroup is a set S equipped with an associative operation $$s \cdot t$$ (often written st). In particular, $$A^+$$ equipped with concatenation is a semigroup. Given a finite semigroup S, it is easy to see that there is an integer $$\omega (S)$$ (denoted by $$\omega$$ when S is understood) such that for all s of S, $$s^\omega$$ is idempotent: $$s^\omega = s^\omega s^\omega$$.
Given a language L and a morphism $$\alpha : A^+ \rightarrow S$$, we say that L is recognized by $$\alpha$$ if there exists $$F \subseteq S$$ such that $$L = \alpha ^{-1}(F)$$. It is well-known that a language is regular if and only if it may be recognized by a finite semigroup.
Wilke Algebras. A Wilke algebra is a pair $$(S_+,S_\infty )$$, where $$S_+$$ is a semigroup and $$S_\infty$$ is a set. Moreover, $$(S_+,S_\infty )$$ is equipped with two additional products: a mixed product$$S_+ \times S_\infty \rightarrow S_\infty$$ mapping $$s,t \in S_+,S_\infty$$ to an element st of $$S_\infty$$, and an infinite product$$(S_+)^\infty \rightarrow S_\infty$$ mapping an infinite sequence $$s_1,s_2,\dots \in (S_+)^\infty$$ to an element $$s_1s_2\cdots$$ of $$S_\infty$$. We require these products to satisfy all possible forms of associativity. For $$s\in S_+$$, we let $$s^\infty$$ be the infinite product $$sss\cdots \in S_\infty$$. Note that $$(A^+,A^\infty )$$ is a Wilke algebra. See [12] for further details (we use a distinct notation from [12], where what we write $$s^\omega ,s^\infty$$ is noted $$s^\pi ,s^\omega$$, respectively).
We say that $$(S_+,S_\infty )$$ is finite if both $$S_+$$ and $$S_\infty$$ are. Note that even if a Wilke algebra is finite, it is not clear how to represent the infinite product, since the set of infinite sequences of $$S_+$$ is uncountable. However, it has been shown by Wilke [28] that the infinite product is fully determined by the mapping $$s \mapsto s^\infty$$. This makes it possible to finitely represent any finite Wilke algebra.
Morphisms of Wilke algebras are defined in the natural way. In particular, observe that any morphism of Wilke algebra $$\alpha : (A^+,A^\infty ) \rightarrow (S_+,S_\infty )$$ defines two maps: a semigroup morphism $$\alpha _+: A^+ \rightarrow S_+$$ and a map $$\alpha _\infty : A^\infty \rightarrow S_\infty$$ (when there is no ambiguity, we shall write $$\alpha (w)$$ to mean $$\alpha _+(w)$$ if $$w\in A^+$$ or $$\alpha _\infty (w)$$ if $$w\in A^\infty$$). Therefore, a morphism recognizes both languages (the languages $$\alpha _+^{-1}(F_+)$$ for $$F_+ \subseteq S_+$$) and languages of infinite words (the languages of infinite words $$\alpha _\infty ^{-1}(F_\infty )$$ for $$F_\infty \subseteq S_\infty$$). A language of infinite words is regular iff it may be recognized by a morphism into a finite Wilke algebra.
Syntactic Morphisms. It is known that given any regular language (resp. language of infinite words) L, there exists a canonical morphism $$\alpha _L: A^+ \rightarrow S$$ (resp. $$\alpha _L: (A^+,A^\infty ) \rightarrow (S_+,S_\infty )$$) recognizing L. This object is called the syntactic morphism of L. We refer the reader to [12] for the detailed definition of this object. In the paper we only use two properties of the syntactic morphism. The first is that given any regular language of infinite words L, one can compute its syntactic morphism from any representation of L. We state the second one below.
### Fact 2
Let $$i \geqslant 1$$ and let L be a regular language of infinite words. Then L is definable in $$\mathcal {B}\varSigma _{{i}}$$ iff so are all languages of words and infinite words recognized by its syntactic morphism.
The proof of Fact 2 may be found in [12] (in fact, this holds for any class of languages of infinite words which forms a “variety” of languages of infinite words, not just for $$\mathcal {B}\varSigma _{{i}}$$). In view of this, the syntactic morphism is central for membership questions: deciding if a language is definable in $$\mathcal {B}\varSigma _{{i}}$$ amounts to deciding a property of its syntactic morphism. This is the approach used in our membership algorithm for $$\mathcal {B}\varSigma _{2}$$ (see Sect. 5).
Morphisms and Separation. When working on separation, we are given two input languages or languages of infinite words. It is convenient to consider a single recognizing object for both inputs rather than two separate objects. This is not restrictive: given two languages (resp. two languages of infinite words) and two associated recognizing morphisms, one can define and compute a single morphism that recognizes them both. For example, if $$L_0 \subseteq A^\infty$$ is recognized by $$\alpha _0: (A^+,A^\infty ) \rightarrow (S_+,S_\infty )$$ and $$L_1 \subseteq A^\infty$$ by $$\alpha _1: (A^+,A^\infty ) \rightarrow (T_+,T_\infty )$$, then $$L_0$$ and $$L_1$$ are both recognized by $$\alpha : (A^+,A^\infty ) \rightarrow (S_+\times T_+,S_\infty \times T_\infty )$$ with $$\alpha (w) =(\alpha _0(w),\alpha _1(w))$$.
Alphabet Compatible Morphisms. It will be convenient to work with morphisms that satisfy an additional property. A morphism $$\alpha : (A^+,A^\infty ) \rightarrow (S_+,S_\infty )$$ is said to be alphabet compatible if for all $$u,v \in A^+ \cup A^\infty$$, $$\alpha (u) = \alpha (v)$$ implies $$\textsf {alph}(u) = \textsf {alph}(v)$$. Note that when $$\alpha$$ is alphabet compatible, for all $$s \in S_+ \cup S_\infty$$, $$\textsf {alph}(s)$$ is well defined as the unique $$B \subseteq A$$ such that for all $$u \in \alpha ^{-1}(s)$$, we have $$\textsf {alph}(u) = B$$ (if s has no preimage then we simply set $$\textsf {alph}(s) = \emptyset$$).
To any morphism $$\alpha : (A^+,A^\infty ) \rightarrow (S_+,S_\infty )$$, we associate a morphism $$\beta$$, called the alphabet completion of $$\alpha$$. The morphism $$\beta$$ recognizes all languages of infinite words recognized by $$\alpha$$ and is alphabet compatible. If $$\alpha$$ is already alphabet compatible, then $$\beta = \alpha$$. Otherwise, observe that $$2^A$$ is a semigroup with union as the multiplication and $$(2^A,2^A)$$ is therefore a Wilke algebra. Hence, we let $$\beta$$ be the morphism: $$\beta : (A^+,A^\infty ) \rightarrow (S_+ \times 2^A,S_\infty \times 2^A)$$ with $$\beta (w) = (\alpha (w),\textsf {alph}(w))$$.
### 2.2 Logical Preorders
To each level $$\varSigma _{{i}}$$ in the hierarchy, one may associate preorders on the sets of words and infinite words. The definition is based on the notion of quantifier rank. The quantifier rank of a first-order formula is the length of the longest sequence of nested quantifiers inside the formula. For example, the following sentence,
$$\exists x\ P_b(x) \wedge \lnot (\exists y\ (y < x \wedge P_c(y)) \wedge (\forall y\exists z\ x < y < z \wedge P_b(y)))$$
has quantifier rank 3. It is well-known (and easy to show) that for a fixed k, there is a finite number of non-equivalent first-order sentences of rank less than k.
We now define the preorders. Note that while we define two preorders for each level $$\varSigma _{{i}}$$ (one on $$A^+$$, one on $$A^\infty$$), we actually use the same notation for both. Let $$i \geqslant 1$$ be a level in the hierarchy and $$k \geqslant 1$$ as a quantifier rank. Given two words $$w,w' \in A^+$$ (resp two infinite words $$w,w' \in A^\infty$$), we write $$w \lesssim ^{k}_{i} w'$$ if and only if any$$\varSigma _{{i}}$$ sentence of rank at most k satisfied by w is satisfied by $$w'$$ as well. By contrapositive, since the negation of a $$\varSigma _{{i}}$$ sentence is in $$\varPi _{{i}}$$, we have $$w \lesssim ^{k}_{i} w'$$ iff any $$\varPi _{{i}}$$ sentence of rank at most k satisfied by $$w'$$ is also satisfied by w.
One may verify that $$\lesssim ^{k}_{i}$$ is preorder. Moreover, it is immediate that the preorders get refined when k or i increase: $$w \lesssim ^{k+1}_{i} w'$$ or $$w \lesssim ^{k}_{i+1} w'$$ imply $$w \lesssim ^{k}_{i} w'$$. Since a $$\varPi _{i+1}$$ sentence is in $$\varSigma _{{i}}$$, $$w \lesssim ^{k}_{i+1} w'$$ also implies $$w'\lesssim ^{k}_{i} w$$.
Denote by $$\cong ^{k}_{i}$$ the equivalence generated by $$\lesssim ^{k}_{i}$$: $$w \cong ^{k}_{i} w'$$ when $$w \lesssim ^{k}_{i} w'$$ and $$w' \lesssim ^{k}_{i} w$$. That is, $$w \cong ^{k}_{i} w'$$ if and only if $$w,w'$$ satisfy the same $$\varSigma _{{i}}$$ sentences (or equivalently the same $$\mathcal {B}\varSigma _{{i}}$$ sentences, which are nothing but Boolean combinations of $$\varSigma _{{i}}$$ sentences). The following fact sums up what we just observed.
### Fact 3
Let $$k,i \geqslant 1$$ and let uv be two words or two infinite words, then
$$(1)\ u \lesssim ^{k+1}_{i} v \Rightarrow u \lesssim ^{k}_{i} v, \qquad (2)\ u \cong ^{k+1}_{i} v \Rightarrow u \cong ^{k}_{i} v \qquad (3)\ u \lesssim ^{k}_{i+1} v \Rightarrow u \cong ^{k}_{i} v.$$
We finish the section with a few properties about the preorders $$\lesssim ^{k}_{i}$$. The proofs are easy and omitted (they are obtained with standard Ehrenfeucht-Fraïssé arguments). We start with decomposition and composition lemmas.
### Lemma 4
(Decomposition Lemma). Let $$i,k \geqslant 1$$ and let uv be two words or two infinite words such that $$u \lesssim ^{k}_{i} v$$. Then for any decomposition $$u=u_1u_2$$ of u, there exist $$v_1,v_2$$ such that $$v=v_1v_2$$, $$u_1\lesssim ^{k-1}_{i} v_1$$ and $$u_2 \lesssim ^{k-1}_{i} v_2$$ .
### Lemma 5
(Composition Lemma). Let $$i,k \geqslant 1$$, let $$u_1,v_1$$ be two words such that $$u_1\lesssim ^{k}_{i} v_1$$, and $$u_2,v_2$$ be either two words or two infinite words such that $$u_2 \lesssim ^{k}_{i} v_2$$. Then $$u_1u_2\lesssim ^{k}_{i} v_1v_2$$ and $$u_1^\infty \lesssim ^{k}_{i} v_1^\infty$$.
The last composition that we state is specific to infinite words.
### Lemma 6
Let $$i,k \geqslant 1$$, $$u \in A^+$$ be a word and $$v \in A^\infty$$ be an infinite word such that $$v \lesssim ^{k}_{i} u^\infty$$. Then for any $$\ell \geqslant 2^k$$, we have $$u^\infty \lesssim ^{k}_{i+1} u^\ell v$$.
In particular we will use the special case of Lemma 6 in which $$i=1$$. In this case, one can verify that given $$u \in A^+$$ and $$v \in A^\infty$$, when $$\textsf {alph}(u) = \textsf {alph}(v)$$, we have $$v \lesssim ^{k}_{1} u^\infty$$ for any $$k \geqslant 1$$. Hence we have the following corollary of Lemma 6.
### Corollary 7
Let $$k \geqslant 1$$, $$u \in A^+$$ be a word and let $$v \in A^\infty$$ be an infinite word such that $$\textsf {alph}(u) = \textsf {alph}(v)$$. Then for any $$\ell \geqslant 2^k$$, we have $$u^\infty \lesssim ^{k}_{2} u^\ell v$$.
## 3 $$\varSigma _{{i}}$$-Chains for Language of Infinite Words
All algorithms for infinite words of this paper are strongly related to the finite words algorithms of [16, 18]. In particular, we adapt and reuse the key notion of “$$\varSigma _{{i}}$$-chain ” which was introduced in [18]. The section is devoted to the presentation of this notion. First, we define $$\varSigma _{{i}}$$-chains. We then detail the link between $$\varSigma _{{i}}$$-chains and our decision problems, first for $$\varSigma _{{i}}$$, then for $$\mathcal {B}\varSigma _{{i}}$$.
$$\varSigma _{{i}}$$-Chains were initially introduced in [18] as a tool designed to investigate the separation problem over finite words for the logics $$\varSigma _{{i}}$$ and $$\mathcal {B}\varSigma _{{i}}$$. A set of $$\varSigma _{{i}}$$-chains can be associated to any morphism $$\alpha : A^+ \rightarrow S$$ into a finite semigroup S. Intuitively, this set captures information about what $$\varSigma _{{i}}$$ and $$\mathcal {B}\varSigma _{{i}}$$ can express about the languages recognized by $$\alpha$$ (including which ones are separable with $$\varSigma _{{i}}$$ and $$\mathcal {B}\varSigma _{{i}}$$). The definition is based on the following classical lemma.
### Lemma 8
Let $$i,k \geqslant 1$$ and $$L_1,L_2$$ be two languages or two languages of infinite words. Then $$L_1$$ is not$$\varSigma _{{i}}$$-separable (resp. not$$\mathcal {B}\varSigma _{{i}}$$-separable) from $$L_2$$ iff for all $$k \geqslant 1$$, there exist $$w_1 \in L_1$$ and $$w_2 \in L_2$$ such that $$w_1 \lesssim ^{k}_{i} w_2$$ (resp. $$w_1 \cong ^{k}_{i} w_2$$).
Lemma 8 states simple criteria equivalent to $$\varSigma _{{i}}$$- and $$\mathcal {B}\varSigma _{{i}}$$-separability. However, both criteria involve a quantification over all natural numbers. Therefore, it is not immediate that they can be decided. Indeed, since both $$A^+$$ and $$A^\infty$$ are infinite sets, $$\lesssim ^{k}_{i}$$ and $$\cong ^{k}_{i}$$ are endlessly refined as k gets larger.
$$\varSigma _{{i}}$$-Chains are designed to deal with this issue. The separation problem takes two regular languages or languages of infinite words as input. Therefore, we have a single morphism that recognizes them both. For example, in the case of infinite words, we have $$\alpha : (A^+,A^\infty ) \rightarrow (S_+,S_\infty )$$, with $$(S_+,S_\infty )$$ a finite Wilke algebra, that recognizes both inputs. Intuitively, $$S_+$$ and $$S_\infty$$ are finite abstractions of $$A^+$$ and $$A^\infty$$. Consequently, we may abstract the preorders $$\lesssim ^{k}_{i}$$ on these two finite sets: this is what $$\varSigma _{{i}}$$-chains are. For example, we say that $$(s,t) \in (S_\infty )^2$$ is a $$\varSigma _{{i}}$$-chain (of length 2) for $$\alpha$$ if for all k, there exist $$u,v \in A^\infty$$ such that $$\alpha (u) = s$$, $$\alpha (v) = t$$ and $$u \lesssim ^{k}_{i} v$$. For languages of infinite words recognized by $$\alpha$$, it is then easy to adapt the two criteria of Lemma 8 to work directly with the $$\varSigma _{{i}}$$-chains associated to $$\alpha$$. In other words, we reduce separation to the (still difficult) problem of computing the set of $$\varSigma _{{i}}$$-chains associated to a given input morphism.
Chains. Let us now define chains. Given a finite set S, a chain over S is simply a finite word over S (i.e., an element of $$S^+$$). We shall only consider chains over $$S_+$$ and over $$S_\infty$$, where $$S_+$$ and $$S_\infty$$ are the two components of some Wilke algebra $$(S_+,S_\infty )$$. A remark about notation is in order: a word is usually denoted as the concatenation of its letters. However, since $$S_+$$ is a semigroup, this would be ambiguous: when $$st \in (S_+)^+$$, st could either mean a word with 2 letters s and t, or the product of s and t in $$S_+$$. To avoid confusion, we will write $$(s_1,\dots ,s_n)$$ for a chain of length n. We denote chains by $$\bar{s},\bar{t},\dots$$ and sets of chains by $$\mathcal {S},\mathcal {T},$$...
If $$(S_+,S_\infty )$$ is a Wilke algebra, then for all $$n \in \mathbb {N}$$, $$(S_+)^n$$ is a semigroup when equipped with the componentwise multiplication $$(s_1,\dots ,s_n)(t_1,\dots ,t_n)=(s_1t_1,\dots ,s_nt_n)$$. Moreover, the pair $$((S_+)^n,(S_\infty )^n)$$ is a Wilke algebra (in which the mixed and infinite products are defined componentwise as well).
$$\varSigma _{{i}}$$-Chains. Fix $$i \geqslant 1$$ and $$x \in \{+,\infty \}$$. We associate a set of $$\varSigma _{{i}}$$-chains to any map $$\beta : A^x \rightarrow S$$ where S is a finite set. The set $$\mathcal {C} _i[\beta ] \subseteq S^+$$ of $$\varSigma _{{i}}$$-chains for $$\beta$$ is defined as follows. Let $$\bar{s} = (s_1,\dots ,s_n) \in S^+$$ be a chain. We have $$\bar{s} \in \mathcal {C} _i[\beta ]$$ if and only if for all $$k \in \mathbb {N}$$, there exist $$w_1,\dots ,w_n \in A^x$$ such that:
$$w_1 \lesssim ^{k}_{i} w_2 \lesssim ^{k}_{i} \cdots \lesssim ^{k}_{i} w_n \text { and for all } j,\ \beta (w_j) = s_j.$$
We let $$\mathcal {C} _{i,n}[\beta ]$$ be the restriction of this set to chains of length n: $$\mathcal {C} _{i,n}[\beta ] = \mathcal {C} _{i}[\beta ] \cap S^n$$.
$$\varSigma _{{i}}$$-Chains Associated to a Morphism. It follows from the definition of $$\varSigma _{{i}}$$-chains that one may associate a set $$\mathcal {C} _i[\alpha ]$$ to any semigroup morphism $$\alpha : A^+ \rightarrow S$$. This set is exactly the set of $$\varSigma _{{i}}$$-chains associated to $$\alpha$$ as defined in [18].
Moreover, given a morphism $$\alpha : (A^+,A^\infty ) \rightarrow (S_+,S_\infty )$$ into a finite Wilke algebra $$(S_+,S_\infty )$$, one may associate two sets of $$\varSigma _{{i}}$$-chains to $$\alpha$$: one to the morphism $$\alpha _+: A^+ \rightarrow S_+$$ ($$\mathcal {C} _{i}[\alpha _+] \subseteq (S_+)^+$$) and one to the map $$\alpha _\infty : A^\infty \rightarrow S_\infty$$ ($$\mathcal {C} _{i}[\alpha _\infty ] \subseteq (S_\infty )^+$$). We may now link $$\varSigma _{{i}}$$-chains to the separation problem.
### 3.1 $$\varSigma _{{i}}$$-Chains and Separation for $$\varSigma _{{i}}$$
We now connect $$\varSigma _{{i}}$$-chains to the separation problem. We begin with the simplest connection, which is between $$\varSigma _{{i}}$$-chains of length 2 and separation for $$\varSigma _{{i}}$$.
### Theorem 9
Let $$i \geqslant 1$$, $$x \in \{+,\infty \}$$ and $$\beta : A^x \rightarrow S$$ a map into a finite set S. Given $$F_1,F_2 \subseteq S$$, $$L_1 = \beta ^{-1}(F_1)$$ and $$L_2 = \beta ^{-1}(F_2)$$, the following are equivalent
1. 1.
$$L_1$$ is not$$\varSigma _{{i}}$$-separable from $$L_2$$.
2. 2.
there exist $$s_1 \in F_1$$ and $$s_2 \in F_2$$ such that $$(s_1,s_2) \in \mathcal {C} _{i,2}[\beta ]$$.
Theorem 9 is a straightforward consequence of the statement for $$\varSigma _{{i}}$$ in Lemma 8. In view of the theorem, our approach for the $$\varSigma _{{i}}$$-separation problem is as follows:
• for languages, we look for an algorithm computing $$\mathcal {C} _{i,2}[\alpha ]$$ from an input morphism $$\alpha : A^+ \rightarrow S$$ into a finite semigroup S.
• for languages of infinite words, we look for an algorithm computing $$\mathcal {C} _{i,2}[\alpha _\infty ]$$ from an input morphism $$\alpha : (A^+,A^\infty ) \rightarrow (S_+,S_\infty )$$ into a finite Wilke algebra $$(S_+,S_\infty )$$. Typically, this algorithm involves computing $$\mathcal {C} _{i,2}[\alpha _+]$$ first, which can be achieved by reusing the first item, i.e., the algorithm for word languages.
This approach is exactly the one used in [16, 18] to solve separation for $$\varSigma _{2}$$ and $$\varSigma _{3}$$ over finite words: the following theorems are proven in these papers.
### Theorem 10
(see [18]). Given as input a morphism $$\alpha : A^+ \rightarrow S$$ into a finite semigroup S, one can compute the set $$\mathcal {C} _{2,2}[\alpha ]$$ of $$\varSigma _{2}$$-chains of length 2 for $$\alpha$$.
### Theorem 11
(see [16]). Given as input a morphism $$\alpha : A^+ \rightarrow S$$ into a finite semigroup S, one can compute the set $$\mathcal {C} _{3,2}[\alpha ]$$ of $$\varSigma _{3}$$-chains of length 2 for $$\alpha$$.
We generalize these two theorems in Sect. 4 (for $$\varSigma _{2}$$) and Sect. 6 (for $$\varSigma _{3}$$) for infinite words by presenting two new algorithms. These algorithms both take a morphism $$\alpha : (A^+,A^\infty ) \rightarrow (S_+,S_\infty )$$ as input and compute the sets $$\mathcal {C} _{2,2}[\alpha _\infty ]$$ and $$\mathcal {C} _{3,2}[\alpha _\infty ]$$ respectively. The algorithms of Theorems 10 and 11 are reused as sub-procedures in these new algorithms for languages of infinite words: computing $$\mathcal {C} _{2,2}[\alpha _\infty ]$$ and $$\mathcal {C} _{3,2}[\alpha _\infty ]$$ requires to first compute $$\mathcal {C} _{2,2}[\alpha _+]$$ and $$\mathcal {C} _{3,2}[\alpha _+]$$.
### Remark 12
The algorithms of Theorems 10 and 11 both work with objects that are actually more general than $$\varSigma _{{i}}$$-chains: the $$\varSigma _{2}$$ algorithm works with “$$\varSigma _{2}$$-junctures ” and the $$\varSigma _{3}$$ algorithm with an even more general notion: “$$\Sigma _{2,3}$$-trees”. We do not present these more general notions because we do not need them outside of the algorithms of Theorems 10 and 11, which we use as black boxes.
### 3.2 $$\varSigma _{{i}}$$-Chains and Separation for $$\mathcal {B}\varSigma _{{i}}$$
We finish by presenting the connection between the separation problem for $$\mathcal {B}\varSigma _{{i}}$$ and $$\varSigma _{{i}}$$-chains. This time, the connection depends on the whole set of $$\varSigma _{{i}}$$-chains. More precisely, it depends on yet another notion called alternation.
Let $$x \in \{+,\infty \}$$ and $$\beta : A^x \rightarrow S$$ be a map into a finite set S. We say that a pair $$(s,t) \in S^2$$ is $$\varSigma _{{i}}$$-alternating for $$\beta$$ iff for all $$n \geqslant 1$$, we have $$(s,t)^n \in \mathcal {C} _i[\beta ]$$ (where by $$(s,t)^n$$, we mean the chain $$(s,t,s,t,\dots ,s,t)$$ of length 2n).
### Theorem 13
Let $$i \geqslant 1$$, $$x \in \{+,\infty \}$$ and $$\beta : A^x \rightarrow S$$ a map into a finite set S. Given $$F_1,F_2 \subseteq S$$, $$L_1 = \beta ^{-1}(F_1)$$ and $$L_2 = \beta ^{-1}(F_2)$$, the following are equivalent:
1. 1.
$$L_1$$ is not$$\mathcal {B}\varSigma _{{i}}$$-separable from $$L_2$$.
2. 2.
there exist $$s_1 \in F_1$$ and $$s_2 \in F_2$$ such that $$(s_1,s_2)$$ is $$\varSigma _{{i}}$$-alternating.
The proof of Theorem 13 is based on the second part of Lemma 8. In view of the theorem, the separation problem for $$\mathcal {B}\varSigma _{{i}}$$ reduces to the computation of the $$\varSigma _{{i}}$$-alternating pairs, which is unfortunately open for $$i \geqslant 2$$, even on finite words.
Regarding membership however, Theorem 13 yields an immediate corollary. For $$x \in \{+,\infty \}$$ and $$\beta : A^x \rightarrow S$$ a map into a finite set S, we say that $$\beta$$ has bounded$$\varSigma _{{i}}$$-alternation iff every $$\varSigma _{{i}}$$-alternating pair $$(s,t) \in S^2$$ for $$\beta$$ satisfies $$s = t$$.
### Corollary 14
Let $$i \geqslant 1$$, $$x \in \{+,\infty \}$$ and $$\beta : A^x \rightarrow S$$ be a map into a finite set S. Then all sets $$\beta ^{-1}(F)$$ for $$F \subseteq S$$ are $$\mathcal {B}\varSigma _{{i}}$$-definable if and only if $$\beta$$ has bounded $$\varSigma _{{i}}$$-alternation.
Combining Corollary 14 with Fact 2 yields a criterion for $$\mathcal {B}\varSigma _{{i}}$$-membership: a regular language of finite or infinite words is definable in $$\mathcal {B}\varSigma _{{i}}$$ iff its syntactic morphism has bounded $$\varSigma _{{i}}$$-alternation. This is used in [18] to obtain a (language) membership algorithm for $$\mathcal {B}\varSigma _{2}$$. More precisely, the following result is proved.
### Theorem 15
(see [18]). Given as input a morphism $$\alpha : A^+ \rightarrow S$$ into a finite semigroup S, one can decide whether $$\alpha$$ has bounded $$\varSigma _{2}$$-alternation or not.
In Sect. 5 we obtain our algorithm for $$\mathcal {B}\varSigma _{2}$$-membership over infinite words by proving that given a morphism $$\alpha : (A^+,A^\infty ) \rightarrow (S_+,S_\infty )$$ as input, one can decide whether $$\alpha _\infty$$ has bounded $$\varSigma _{2}$$-alternation or not. More precisely, we prove that $$\alpha _\infty$$ having bounded $$\varSigma _{2}$$-alternation is equivalent to two decidable properties of $$\alpha$$. The first is that $$\alpha _+$$ has bounded $$\varSigma _{2}$$-alternation (which we can decide by Theorem 15). The second is a simple equation that $$(S_+,S_\infty )$$ needs to satisfy.
## 4 A Separation Algorithm for $$\varSigma _{2}$$
In this section, we present an algorithm for the separation problem associated to $$\varSigma _{2}$$ over infinite words. As expected, this algorithm is based on the computation of $$\varSigma _{2}$$-chains of length 2 (see Theorem 9): we prove that given a morphism $$\alpha$$ into a finite Wilke algebra, one can compute $$\mathcal {C} _{2,2}[\alpha _\infty ]$$.
For an alphabet compatible morphism $$\alpha : (A^+,A^\infty ) \rightarrow (S_+,S_\infty )$$ into a finite Wilke algebra, we denote by $$\mathord {\mathrm {Calc}}_{\varSigma _{2}}(\alpha )$$ the set of all pairs:
$$(r_1(s_1)^\infty ,\;r_2(s_2)^\omega t_2) \in S_\infty \times S_\infty$$
with $$(r_1,r_2) \in \mathcal {C} _{2,2}[\alpha _+]$$, $$(s_1,s_2) \in \mathcal {C} _{2,2}[\alpha _+]$$, $$t_2 \in \alpha (A^\infty )$$ and $$\textsf {alph}(s_1) = \textsf {alph}(t_2)$$. Note that this last condition is well defined since $$\alpha$$ is alphabet compatible. Recall that $$s_1^\infty$$ is the infinite product $$s_1s_1\ldots$$, and $$s_2^\omega$$ the idempotent power of $$s_2$$ in $$S_+$$.
### Proposition 16
Let $$\alpha : (A^+,A^\infty ) \rightarrow (S_+,S_\infty )$$ be an alphabet compatible morphism into a finite Wilke algebra $$(S_+,S_\infty )$$. Then, $$\mathcal {C} _{2,2}[\alpha _\infty ] = \mathord {\mathrm {Calc}}_{\varSigma _{2}}(\alpha )$$.
A consequence of Proposition 16 is that the separation problem is decidable for $$\varSigma _{2}$$ over infinite words. Indeed, recall that for any two regular languages of infinite words, one may compute a single alphabet compatible Wilke algebra morphism that recognizes them both. Therefore, it follows from Theorem 9 that deciding $$\varSigma _{2}$$-separation amounts to having an algorithm that computes $$\mathcal {C} _{2,2}[\alpha _\infty ]$$ from $$\alpha$$.
We obtain this algorithm from Proposition 16 since $$\mathord {\mathrm {Calc}}_{\varSigma _{2}}(\alpha )$$ may be computed, given $$\alpha$$ as input. Indeed, by Theorem 10, we already know that the set $$\mathcal {C} _{2,2}[\alpha _+]$$ can be computed from $$\alpha$$. Hence, we obtain the desired corollary.
### Corollary 17
Over infinite words, the separation problem is decidable for $$\varSigma _{2}$$.
An important remark is that we use Theorem 10 as a black box: we do not reprove that $$\mathcal {C} _{2,2}[\alpha _+]$$ may be computed from $$\alpha _+$$. This is not an immediate result. In fact, the proof of [18] requires to use a framework that is more general than $$\varSigma _{2}$$-chains (that of “$$\varSigma _{2}$$-junctures ”) as well as arguments that are independent from those that we are going to use to prove Proposition 16.
It remains to prove Proposition 16. We illustrate the algorithm by proving the easier inclusion: $$\mathcal {C} _{2,2}[\alpha _\infty ] \supseteq \mathord {\mathrm {Calc}}_{\varSigma _{2}}(\alpha )$$ (this proves correctness: all computed chains are indeed $$\varSigma _{2}$$-chains). The converse inclusion (corresponding to completeness: all $$\varSigma _{2}$$-chains are computed) is available in the long version of the paper.
Correctness Proof:$$\varvec{\mathcal {C} _{2,2}[\alpha _\infty ] \supseteq \mathord {\mathrm {Calc}}_{\varSigma _{2}}(\alpha )}$$. Let $$(r_1,r_2) \in \mathcal {C} _{2,2}[\alpha _+]$$, $$(s_1,s_2) \in \mathcal {C} _{2,2}[\alpha _+]$$ and $$t_2 \in \alpha (A^\infty )$$ such that $$\textsf {alph}(s_1) = \textsf {alph}(t_2)$$. Our objective is to prove that $$(r_1(s_1)^\infty ,r_2(s_2)^\omega t_2) \in \mathcal {C} _{2,2}[\alpha _\infty ]$$. Let $$k \geqslant 1$$. By definition, we need to find two infinite words $$w_1 \lesssim ^{k}_{2} w_2$$ such that $$\alpha (w_1) = r_1(s_1)^\infty$$ and $$\alpha (w_2) = r_2(s_2)^\omega t_2$$.
By hypothesis, we have four words $$x_1,x_2,y_1,y_2 \in A^+$$ such that $$x_1 \lesssim ^{k}_{2} x_2$$, $$y_1 \lesssim ^{k}_{2} y_2$$, $$\alpha (x_1) = r_1$$, $$\alpha (x_2) = r_2$$, $$\alpha (y_1) = s_1$$ and $$\alpha (y_2) = s_2$$. Moreover, we have an infinite word $$z \in A^\infty$$ such $$\alpha (z) = t_2$$ and $$\textsf {alph}(y_1) = \textsf {alph}(z)$$. Let $$w_1 = x_1(y_1)^\infty$$ and $$w_2 = x_2(y_2)^{2^k\omega }z$$. Observe that by definition, we have $$\alpha (w_1) = r_1(s_1)^\infty$$ and $$\alpha (w_2) = r_2(s_2)^\omega t_2$$. Therefore, it remains to prove that $$w_1 \lesssim ^{k}_{2} w_2$$.
By Corollary 7, we obtain that $$(y_1)^\infty \lesssim ^{k}_{2} (y_1)^{2^k\omega }z$$. Moreover, using $$y_1 \lesssim ^{k}_{2} y_2$$ and $$z \lesssim ^{k}_{2} z$$ together with Lemma 5, we obtain $$(y_1)^{2^k\omega }z \lesssim ^{k}_{2} (y_2)^{2^k\omega }z$$. Therefore, by transitivity $$(y_1)^\infty \lesssim ^{k}_{2} (y_2)^{2^k\omega }z$$. Finally, we use the fact that $$x_1 \lesssim ^{k}_{2} x_2$$ and Lemma 5 to conclude that $$x_1(y_1)^\infty \lesssim ^{k}_{2} x_2(y_2)^{2^k\omega }z$$, i.e., that $$w_1 \lesssim ^{k}_{2} w_2$$. $$\square$$
## 5 A Membership Algorithm for $$\mathcal {B}\varSigma _{2}$$
We now present our membership algorithm for $$\mathcal {B}\varSigma _{2}$$ over infinite words. The algorithm is stated as a decidable characterization of $$\mathcal {B}\varSigma _{2}$$ over infinite words.
### Theorem 18
Let $$L\subseteq A^\infty$$ be regular and let $$\alpha :(A^+,A^\infty ) \rightarrow (S_+,S_\infty )$$ be the alphabet completion of its syntactic morphism. The following are equivalent:
1. 1.
L is definable in $$\mathcal {B}\varSigma _{2}$$.
2. 2.
$$\alpha _\infty$$ has bounded $$\varSigma _{2}$$-alternation.
3. 3.
$$\alpha _+$$ has bounded $$\varSigma _{2}$$-alternation and $$\alpha$$ satisfies the following equation:
\begin{aligned} (st^\omega )^\infty = (st^\omega )^\omega st^\infty \text { for all } s,t \in \alpha (A^+) \text { such that } \textsf {alph}(s) = \textsf {alph}(t) \end{aligned}
(1)
We know that Item 3 in Theorem 18 is decidable. Indeed, Theorem 15 states that whether $$\alpha _+$$ has bounded $$\varSigma _{2}$$-alternation is decidable (note however that this is a difficult result of [18] whose proof is independent from that of Theorem 18). Moreover, verifying that (1) is satisfied may be achieved by checking all possible combinations. Therefore, we obtain the following corollary of Theorem 18.
### Corollary 19
The membership problem over infinite words is decidable for $$\mathcal {B}\varSigma _{2}$$.
It now remains to prove Theorem 18. That $$2) \Rightarrow 1)$$ is immediate from Corollary 14. The most difficult (and interesting) direction is $$3) \Rightarrow 2)$$. Due to lack of space, it is proved in the long version of this paper. As we did in the previous section, we illustrate the theorem by proving the easier $$1) \Rightarrow 3)$$ direction.
Proof of$$1) \Rightarrow 3)$$. Let L be $$\mathcal {B}\varSigma _{2}$$-definable. In particular, this means that every language of finite or infinite words recognized by $$\alpha$$ is definable in $$\mathcal {B}\varSigma _{2}$$ (we know from Fact 2 that it is true for the syntactic morphism of L, so this is true as well for its alphabet completion $$\alpha$$, as one can test the alphabet of a word in $$\mathcal {B}\varSigma _{2}$$).
Since every language recognized by $$\alpha$$ is definable in $$\mathcal {B}\varSigma _{2}$$, Corollary 14 entails that $$\alpha _+$$ has bounded $$\varSigma _{2}$$-alternation. It remains to establish Eq. (1). For $$s,t \in \alpha (A^+)$$ such that $$\textsf {alph}(s) = \textsf {alph}(t)$$, let us show that $$(st^\omega )^\infty = (st^\omega )^\omega st^\infty$$.
Let k such that for any $$r \in S_\infty$$, $$\alpha ^{-1}(r)$$ may be defined by a $$\mathcal {B}\varSigma _{2}$$ sentence of quantifier rank less than k (k exists since all these languages of infinite words are definable in $$\mathcal {B}\varSigma _{2}$$). By choice of k, for any two infinite words $$u,v \in A^\infty$$, we have $$u \cong ^{k}_{2} v \Rightarrow \alpha (u) = \alpha (v)$$. Therefore, in order to conclude, it suffices to find two infinite words uv of images $$(st^\omega )^\infty$$ and $$(st^\omega )^\omega st^\infty$$ and such that $$u \cong ^{k}_{2} v$$.
By definition of st, we have words $$x,y \in A^+$$ such that $$\alpha (x) = s$$, $$\alpha (y) = t$$ and $$\textsf {alph}(x) = \textsf {alph}(y)$$. Let $$u = (xy^{2^k\omega })^\infty$$ and $$v = (xy^{2^k\omega })^{2^k\omega } xy^\infty$$. It is imediate that u and v have images $$(st^\omega )^\infty$$ and $$(st^\omega )^\omega st^\infty$$. It remains to prove that $$u \cong ^{k}_{2} v$$.
We prove that $$u \lesssim ^{k}_{2} v$$ and $$v \lesssim ^{k}_{2} u$$. Observe that $$\textsf {alph}(xy^{2^k\omega }) = \textsf {alph}(xy^\infty )$$. Hence, we get $$u \lesssim ^{k}_{2} v$$ from Corollary 7. Conversely, we know that $$\textsf {alph}((xy^{2^k\omega })^\infty ) = \textsf {alph}(y)$$. Therefore, we may use Corollary 7 again to obtain $$y^\infty \lesssim ^{k}_{2} y^{2^k\omega }(xy^{2^k\omega })^\infty$$. That $$v \lesssim ^{k}_{2} u$$ is then immediate from this inequality by Lemma 5.
## 6 A Separation Algorithm for $$\varSigma _{3}$$
We present our algorithm for the separation problem associated to $$\varSigma _{3}$$ over infinite words. As for $$\varSigma _{2}$$, this algorithm is based on Theorem 9: we give a procedure computing $$\mathcal {C} _{3,2}[\alpha _\infty ]$$ from an input morphism $$\alpha : (A^+,A^\infty ) \rightarrow (S_+,S_\infty )$$.
However, in this case, this computation requires a new ingredient. This new ingredient is a generalization of $$\varSigma _{{i}}$$-chains that we call mixed chains.
Mixed Chains. Let $$x \in \{+,\infty \}$$ and $$\beta : A^x \rightarrow S$$ as a map into some finite set S. We define a set $$\mathcal {M} [\beta ] \subseteq S^3$$. Let $$\bar{s} = (s_1,s_2,s_3) \in S^3$$ be a chain over S. We have $$\bar{s} \in \mathcal {M} [\beta ]$$ if and only if for all $$k \in \mathbb {N}$$, there exist $$w_1,w_2,w_3 \in A^x$$ such that,
$$\beta (w_1) = s_1, \ \beta (w_2) = s_2, \ \beta (w_3) = s_3 \quad \text {and}\quad w_1 \lesssim ^{k}_{2} w_2 \lesssim ^{k}_{3} w_3$$
Note the definition involves both the preorder “$$\lesssim ^{k}_{2}$$” associated to $$\varSigma _{2}$$ and the preorder “$$\lesssim ^{k}_{3}$$” associated to $$\varSigma _{3}$$ (hence the name “mixed chains”). An important remark is that we will not present any algorithm for computing mixed chains. On the other hand, our algorithm for computing $$\mathcal {C} _{3,2}[\alpha _\infty ]$$ from a morphism $$\alpha$$ is parametrized by the set of mixed chains $$\mathcal {M} [\alpha _+]$$. That $$\mathcal {M} [\alpha _+]$$ may be computed from $$\alpha _+$$ is a very difficult result of [16], stated below.
### Theorem 20
(see [16]). Given as input a morphism $$\alpha : A^+ \rightarrow S$$ into a finite semigroup S, one can compute the set $$\mathcal {M} [\alpha ]$$ of mixed chains for $$\alpha$$.
### Remark 21
The presentation of Theorem 20 is different in [16]. It is proved that one can compute the set of “$$\Sigma _{2,3}$$-trees” associated to $$\alpha$$. Essentially $$\Sigma _{2,3}$$-trees are trees of depth 3 whose nodes are labeled by elements of a finite set S and mixed chains are the special case when there is only a single branch in the tree.
We may now present our separation algorithm for $$\varSigma _{3}$$ over infinite words. Let $$\alpha : (A^+,A^\infty ) \rightarrow (S_+,S_\infty )$$ be an alphabet compatible morphism into a finite Wilke algebra $$(S_+,S_\infty )$$. We define $$\mathord {\mathrm {Calc}}_{\varSigma _{3}}(\alpha ) \subseteq (S_\infty )^2$$ as the set of all pairs
$$\big (r_2(s_2(t_2)^\omega )^\infty ,\ r_3(s_3(t_3)^\omega )^\omega s_1(t_1)^\infty \big )$$
with $$(r_2,r_3) \in \mathcal {C} _{3,2}[\alpha _+]$$, $$(s_1,s_2,s_3) \in \mathcal {M} [\alpha _+]$$, $$(t_1,t_2,t_3) \in \mathcal {M} [\alpha _+]$$ and $$\textsf {alph}(s_1) = \textsf {alph}(t_1)$$. Since we know from Theorem 20 that one may compute $$\mathcal {M} [\alpha _+]$$ from $$\alpha$$, it is immediate from the definition that one may compute $$\mathord {\mathrm {Calc}}_{\varSigma _{3}}(\alpha )$$ from $$\alpha$$.
### Proposition 22
Let $$\alpha : (A^+,A^\infty ) \rightarrow (S_+,S_\infty )$$ be an alphabet compatible morphism into a finite Wilke algebra $$(S_+,S_\infty )$$. Then, $$\mathcal {C} _{3,2}[\alpha _\infty ] = \mathord {\mathrm {Calc}}_{\varSigma _{3}}(\alpha )$$.
As for $$\varSigma _{2}$$, Proposition 22 immediately yields an algorithm for $$\varSigma _{3}$$-separation over infinite words. Indeed, it provides an algorithm computing $$\mathcal {C} _{3,2}[\alpha _\infty ]$$ from any alphabet compatible morphism $$\alpha$$, which suffices to decide $$\varSigma _{3}$$-separation.
### Corollary 23
The separation problem over infinite words is decidable for $$\varSigma _{3}$$.
It remains to prove Proposition 22. We proceed as for $$\varSigma _{2}$$. Again, we only prove the easier inclusion and postpone the other to the long version of this paper.
Proof of$$\varvec{\mathcal {C} _{3,2}[\alpha _\infty ] \supseteq \mathord {\mathrm {Calc}}_{\varSigma _{3}}(\alpha )}$$. Let $$(r_2,r_3) \in \mathcal {C} _{3,2}[\alpha _+]$$, $$(s_1,s_2,s_3) \in \mathcal {M} [\alpha _+]$$ and $$(t_1,t_2,t_3) \in \mathcal {M} [\alpha _+]$$ be chains such that $$\textsf {alph}(s_1) = \textsf {alph}(t_1)$$. We have to prove that $$(r_2(s_2(t_2)^\omega )^\infty ,r_3(s_3(t_3)^\omega )^\omega s_1(t_1)^\infty ) \in \mathcal {C} _{3,2}[\alpha _\infty ]$$. Let $$k \geqslant 1$$, we need to find two infinite words $$w_2 \lesssim ^{k}_{3} w_3$$ such that $$\alpha (w_2) = r_2(s_2(t_2)^\omega )^\infty$$ and $$\alpha (w_3) = r_3(s_3(t_3)^\omega )^\omega s_1(t_1)^\infty$$. The definition gives words $$x_2,x_3,y_1,y_2,y_3,z_1,z_2,z_3$$ with:
• $$\alpha (x_j)=r_j$$, $$\alpha (y_j)=s_j$$, $$\alpha (z_j)=t_j$$
• $$x_2\lesssim ^{k}_{3} x_3$$, $$y_1\lesssim ^{k}_{2} y_2\lesssim ^{k}_{3} y_3$$ and $$z_1\lesssim ^{k}_{2} z_2 \lesssim ^{k}_{3} z_3$$.
Moreover, as $$\textsf {alph}(s_1)=\textsf {alph}(t_1)$$, we have $$\textsf {alph}(y_1) = \textsf {alph}(z_1)$$. We define $$w_2 = x_2(y_2(z_2)^{2^k\omega })^\infty$$ and $$w_3 = x_3(y_3(z_3)^{2^k\omega })^{2^k\omega } y_1z_1^\infty$$. It is immediate from this definition that $$\alpha (w_2) = r_2(s_2(t_2)^\omega )^\infty$$ and that $$\alpha (w_3) = r_3(s_3(t_3)^\omega )^\omega s_1(t_1)^\infty$$. It remains to prove that $$w_2 \lesssim ^{k}_{3} w_3$$.
We first prove $$y_1z_1^\infty \lesssim ^{k}_{2} (y_2(z_2)^{2^k\omega })^\infty$$. Since $$\textsf {alph}(y_1) = \textsf {alph}(z_1)$$, we may use Corollary 7 to obtain $$z_1^\infty \lesssim ^{k}_{2} (z_1)^{2^k\omega } (y_1(z_1)^{2^k\omega })^\infty$$. By Lemma 5 and transitivity,
\begin{aligned} y_1z_1^\infty \lesssim ^{k}_{2} (y_1(z_1)^{2^k\omega })^\infty \lesssim ^{k}_{2} (y_2(z_2)^{2^k\omega })^\infty \end{aligned}
(2)
We may now use (2) together with Lemma 6 to obtain that $$(y_2(z_2)^{2^k\omega })^\infty \lesssim ^{k}_{3} (y_2(z_2)^{2^k\omega })^{2^k\omega } y_1z_1^\infty$$. Using Lemma 5 and transitivity again, we obtain that
$$x_2(y_2(z_2)^{2^k\omega })^\infty \lesssim ^{k}_{3} x_3(y_3(z_3)^{2^k\omega })^{2^k\omega } y_1z_1^\infty$$
This exactly says that $$w_2 \lesssim ^{k}_{3} w_3$$ which concludes the proof. $$\square$$
## 7 Conclusion
We proved that for languages of infinite words, the separation problem is decidable for $$\varSigma _{2}$$ and $$\varSigma _{3}$$ and that the membership problem is decidable for $$\mathcal {B}\varSigma _{2}$$. Note that using a theorem of [21], these results may be lifted to the variants of these logics whose signature has been enriched with a predicate “$$+1$$”, that is interpreted as the successor relation. This means that over infinite words, separation is decidable for $$\Sigma _{2}(<,+1)$$ and $$\Sigma _{3}(<,+1)$$ and membership is decidable for $$\mathcal {B}\Sigma _{2}(<,+1)$$.
A gap remains between languages and languages of infinite words: we leave open the case of $$\varSigma _{4}$$-membership for languages of infinite words while it is known to be decidable for languages [16]. The language algorithm was based on two ingredients: (1) the decidability of $$\varSigma _{3}$$-separation [16] and (2) an effective reduction of $$\varSigma _{i+1}$$-membership to $$\varSigma _{{i}}$$-separation [18] (which is generic for all $$i \geqslant 1$$). In the setting of languages of infinite words, we are missing the second result and it is not clear whether a similar reduction exists.
## Notes
### Acknowledgements
This study has been carried out with financial support from the French State, managed by the French National Research Agency (ANR) in the frame of the “Investments for the future" Programme IdEx Bordeaux -CPU (ANR-10-IDEX-03-02).
## References
1. 1.
Arfi, M.: Polynomial operations on rational languages. In: Brandenburg, F.J., Vidal-Naquet, G., Wirsing, M. (eds.) STACS’87. LNCS, vol. 247, pp. 198–206. Springer, Heidelberg (1987)Google Scholar
2. 2.
Bojańczyk, M.: The common fragment of ACTL and LTL. In: Amadio, R.M. (ed.) FOSSACS 2008. LNCS, vol. 4962, pp. 172–185. Springer, Heidelberg (2008)
3. 3.
Brzozowski, J.A., Knast, R.: The dot-depth hierarchy of star-free languages is infinite. J. Comput. Syst. Sci. 16(1), 37–55 (1978)
4. 4.
Büchi, J.R.: Weak second-order arithmetic and finite automata. Math. Logic Q. 6(1–6), 66–92 (1960)
5. 5.
Büchi, J.R.: On a decision method in restricted second order arithmetic. In: Logic, Methodology and Philosophy of Science (Proc. 1960 Internat. Congr.), pp. 1–11. Stanford Univ. Press, Stanford (1962)Google Scholar
6. 6.
Czerwiński, W., Martens, W., Masopust, T.: Efficient separability of regular languages by subsequences and suffixes. In: Fomin, F.V., Freivalds, R., Kwiatkowska, M., Peleg, D. (eds.) ICALP 2013, Part II. LNCS, vol. 7966, pp. 150–161. Springer, Heidelberg (2013)Google Scholar
7. 7.
Diekert, V., Kufleitner, M.: Fragments of first-order logic over infinite words. Theory Comput. Syst. 48(3), 486–516 (2011)
8. 8.
Elgot, C.C.: Decision problems of finite automata design and related arithmetics. Trans. Am. Math. Soc. 98(1), 21–51 (1961)
9. 9.
Kufleitner, M., Walter, T.: Level two of the quantifier alternation hierarchy over infinite words. CoRR, abs/1509.06207 (2015)Google Scholar
10. 10.
McNaughton, R., Papert, S.A.: Counter-Free Automata. MIT Press, Cambridge (1971)
11. 11.
Perrin, D.: Recent results on automata and infinite words. In: Chytil, M.P., Koubek, V. (eds.) MFCS 1984. LNCS, vol. 176, pp. 134–148. Springer, Heidelberg (1984)
12. 12.
Perrin, D., Pin, J.É.: Infinite Words. Elsevier, Amsterdam (2004)
13. 13.
Pierron, T., Place, T., Zeitoun, M.: Quantifier alternation for infinite words. CoRR, abs/1511.09011 (2015)Google Scholar
14. 14.
Pin, J.É.: Positive varieties and infinite words. In: Lucchesi, C.L., Moura, A.V. (eds.) LATIN 1998. LNCS, vol. 1380, pp. 76–87. Springer, Heidelberg (1998)
15. 15.
Pin, J.É., Weil, P.: Polynomial closure and unambiguous product. Theory Comput.Syst. 30(4), 383–422 (1997)
16. 16.
Place, T.: Separating regular languages with two quantifier alternations. In: Proceedings of the 30th Annual ACM/IEEE Symposium on Logic in Computer Science (LICS 2015), pp. 202–213. IEEE (2015)Google Scholar
17. 17.
Place, T., van Rooijen, L., Zeitoun, M.: Separating regular languages by piecewise testable and unambiguous languages. In: Chatterjee, K., Sgall, J. (eds.) MFCS 2013. LNCS, vol. 8087, pp. 729–740. Springer, Heidelberg (2013)
18. 18.
Place, T., Zeitoun, M.: Going higher in the first-order quantifier alternation hierarchy on words. In: Esparza, J., Fraigniaud, P., Husfeldt, T., Koutsoupias, E. (eds.) ICALP 2014, Part II. LNCS, vol. 8573, pp. 342–353. Springer, Heidelberg (2014)Google Scholar
19. 19.
Place, T., Zeitoun, M.: Separating regular languages with first-order logic. In: 2014 Proceedings of the Joint Meeting of the 23rd EACSL Annual Conference on Computer Science Logic (CSL 2014), 29th Annual ACM/IEEE Symposium on Logic in Computer Science (LICS 2014), pp. 75:1–75:10. ACM, New York (2011)Google Scholar
20. 20.
Place, T., Zeitoun, M.: Separating $$\omega$$-languages without quantifier alternation (2015) (Unpublished)Google Scholar
21. 21.
Place, T., Zeitoun, M.: Separation and the successor relation. In preparation, long version of [22] (2015)Google Scholar
22. 22.
Place, T., Zeitoun, M.: Separation and the successor relation. In: Mayr, E.W., Ollinger, N. (eds.) 32nd International Symposium on Theoretical Aspects of Computer Science (STACS 2015). Leibniz International Proceedings in Informatics (LIPIcs), vol. 30, pp. 662–675. Schloss Dagstuhl-Leibniz-Zentrum fuer Informatik, Dagstuhl (2015)Google Scholar
23. 23.
Schützenberger, M.P.: On finite monoids having only trivial subgroups. Inf. Control 8(2), 190–194 (1965)
24. 24.
Simon, I.: Piecewise testable events. In: Brakhage, H. (ed.) Automata Theory and Formal Languages. LNCS, vol. 33, pp. 214–222. Springer, Heidelberg (1975)Google Scholar
25. 25.
Stockmeyer, L.J., Meyer, A.R.: Word problems requiring exponential time (preliminary report). In: Proceedings of the Fifth Annual ACM Symposium on Theory of Computing, STOC 1973, pp. 1–9. ACM, New York (1973)Google Scholar
26. 26.
Thomas, W.: A concatenation game and the dot-depth hierarchy. In: Börger, E. (ed.) Computation Theory and Logic. LNCS, vol. 270, pp. 415–426. Springer, Heidelberg (1987)
27. 27.
Trakhtenbrot, B.A.: Finite automata and logic of monadic predicates. Dokl. Akad. Nauk SSSR 149, 326–329 (1961). In RussianGoogle Scholar
28. 28.
Wilke, T.: An Eilenberg theorem for $$\infty$$-languages. In: Leach Albert, J., Monien, B., Rodríguez Artalejo, M. (eds.) ICALP 1991. LNCS, vol. 510, pp. 588–599. Springer, Heidelberg (1991) | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 2, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9768933057785034, "perplexity": 418.08856765821366}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-16/segments/1585370507738.45/warc/CC-MAIN-20200402173940-20200402203940-00384.warc.gz"} |
http://tex.stackexchange.com/questions/24398/making-footmisc-work-with-manyfoot-or-bigfoot?answertab=votes | # Making footmisc work with manyfoot or bigfoot
How is it possible to get the side option of footmisc to work with the manyfoot or bigfoot packages?
The following displays the footnotes in the bottom of the page. The footnotes show on the sides when bigfoot is not used.
\documentclass[twocolumn=true]{scrartcl}
\usepackage{lipsum}
\usepackage{bigfoot}
\DeclareNewFootnote{default}
\DeclareNewFootnote{B}[alph]
\MakeSortedPerPage{footnoteB}
\usepackage[side]{footmisc}
\begin{document}
Hello\footnote{This is some text in the margin that should break and everything.}
World\footnoteB{And some more text that should go to the margin as well and behave like
the other footnote.}.
\lipsum[1-3]
Hello\footnote{This is some text in the margin that should break and everything.}
World\footnoteB{And some more text that should go to the margin as well and behave like
the other footnote.}.
\lipsum[4-6]
\end{document}
Edit:
\documentclass[twocolumn=true]{scrartcl}
\usepackage{lipsum}
\usepackage{bigfoot}
\DeclareNewFootnote{A}[arabic]
\DeclareNewFootnote{B}[alph]
\MakeSortedPerPage{footnoteB}
\newcommand\sidefootnoteA[1]{%
\footnotemarkA
\newcommand\sidefootnoteB[1]{%
\footnotemarkB
\begin{document}
Hello\sidefootnoteA{This is some text in the margin that should break and everything.}
World\sidefootnoteB{And some more text that should go to the margin as well and behave like
the other footnote.}.
\lipsum[1-3]
Hello\sidefootnoteA{This is some text in the margin that should break and everything.}
World\sidefootnoteB{And some more text that should go to the margin as well and behave like
the other footnote.}.
\lipsum[4-6]
\end{document}
It fixes does put the notes in the margin, and it does a good job with counter A, which is numeric, but counter B doesn't get decremented, so I end up with d for the last note.
Edit 2:
The problem comes from \MakeSortedPerPage{footnoteB}. Commenting it fixes the issue.
-
Thanks for fixing the typo @egreg. – ℝaphink Jul 29 '11 at 11:19
I don't think that you can do it. I would do something like this:
\documentclass[twocolumn=true]{scrartcl}
\usepackage{lipsum}
\newcommand\sidefootnote[1]{%
\footnotemark
\begin{document}
Hello\sidefootnote{This is some text in the margin that should break and everything.}
World\sidefootnote{And some more text that should go to the margin as well and behave like
the other footnote.}.
\lipsum[1-3]
\end{document}
-
That's a nice solution to re-implement the side option of footmisc, but it doesn't solve the multi footnote levels problem which bigfoot addresses. – ℝaphink Jul 29 '11 at 13:20
Also, the -1 trick works with numeric counters, but not with letters. – ℝaphink Jul 29 '11 at 13:36
I don't see how you want to place multi footnote levels in the margin. If you only want another numbering: define a \sidefootnoteB: \newcommand\sidefootnoteB[1]{\footnotemarkB{}\marginpar{\addtocounter{footnoteB}{-1}\footnotemarkB{}\raggedright#1}} – Ulrike Fischer Jul 29 '11 at 13:38
footnote is a counter. You can always add -1 to a counter, regardless how you actually print the value. – Ulrike Fischer Jul 29 '11 at 13:39
Hm. Thinking about it I think the second \footnotemark and the \addtocounter is a bit hackish. Better use \textsuperscript{\thefootnoteB} – Ulrike Fischer Jul 29 '11 at 14:31 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.798366367816925, "perplexity": 2290.8139213068916}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-11/segments/1424936462099.15/warc/CC-MAIN-20150226074102-00070-ip-10-28-5-156.ec2.internal.warc.gz"} |
https://www.physicsforums.com/threads/norms-question-parallelogram-law.471205/ | # Norms question (parallelogram law)
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## Homework Statement
Consider the vector space C[a,b] of all continuous complex-valued functions f(x), x$$\in$$ [a,b]. Define a norm ||f|| = max{|f(x)|, x$$\in$$ [a,b]]
a) show that this is a norm
b) Show that this norm does not satisfy the parallelogram law, thereby showing that its not an inner-product norm.
## Homework Equations
Parallelogram law: ||x-y||$$^{2}$$ + ||x+y||$$^{2}$$ = 2||x||$$^{2}$$ + 2||y||$$^{2}$$
## The Attempt at a Solution
I'm mostly having trouble defining the norm. I'm a little unclear on what the concept of a norm is; we only went over inner-product norms in class. I draw the vector going from the origin to the maximum on [a,b] and to define the norm I wrote ||f|| = $$\sqrt{(([vcos])^2 + ([vsin])^2}$$ since that would make it always positive. When I used the parallelogram law, I used x = vcos(theta) and y = vsin(theta). However, I clearly defined the dorm wrong since I got that the two sides of the equation equaled each other.
Is there another way to define a norm? Am I choosing x and y in the parallelogram law wrong?
Last edited:
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tiny-tim
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hi norm!
i don't understand what you're doing
if eg f(x) = x, g(x) = -x, then ||f+g|| = 0, but ||f|| = ||g|| = b
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## zepdrix Linear Algebra - Linear Transformations one year ago one year ago Edit Question Delete Cancel Submit
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The table shows the amount (in g) of protein, carbohydrate, and fat supplied by one unit (100g) of three different foods.
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|dw:1363858488420:dw|
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Betty would like to prepare a meal using some combination of these three foods. She would like the meal to contain 15g of protein, 25g of carbohydrate, and 3g of fat. How many units of each food should she use so that the meal will contain the desired amounts of protein, carbohydrate, and fat?
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I can't seem to remember how to approach this. I think it has something to do with linear transformation. hmm
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you could probably do this on a graphing calc.
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or you could treat each one food as x,y,and z and solve for each.
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Yah I might have to resort to that. These matrices are really confusing me. Maybe I'll just rewrite it as a system of equations and figure it out that way. :p
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much easier that way i think.
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$\large 15x_1+35x_2+25x_3=15$$\large 45x_1+30x_2+50x_3=25$$\large 6x_1+4x_2+x^3=3$ Oh ok I think I'm understanding.. Maybe I'm just suppose to treat this as an augmented matrix, and then I can throw it into my calculator. $\large \left(\begin{array}{ccc|c}15&35&25&15\\45&30&50&25\\6&4&1&3\end{array}\right)$
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Hmm yah it's giving me one of the multiple choices, cool. :o
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https://xianblog.wordpress.com/tag/convergence-rate/ | ## control functionals for Monte Carlo integration
Posted in Books, Statistics, University life with tags , , , , , , , , , , , , , on June 28, 2016 by xi'an
A paper on control variates by Chris Oates, Mark Girolami (Warwick) and Nicolas Chopin (CREST) appeared in a recent issue of Series B. I had read and discussed the paper with them previously and the following is a set of comments I wrote at some stage, to be taken with enough gains of salt since Chris, Mark and Nicolas answered them either orally or in the paper. Note also that I already discussed an earlier version, with comments that are not necessarily coherent with the following ones! [Thanks to the busy softshop this week, I resorted to publish some older drafts, so mileage can vary in the coming days.]
First, it took me quite a while to get over the paper, mostly because I have never worked with reproducible kernel Hilbert spaces (RKHS) before. I looked at some proofs in the appendix and at the whole paper but could not spot anything amiss. It is obviously a major step to uncover a manageable method with a rate that is lower than √n. When I set my PhD student Anne Philippe on the approach via Riemann sums, we were quickly hindered by the dimension issue and could not find a way out. In the first versions of the nested sampling approach, John Skilling had also thought he could get higher convergence rates before realising the Monte Carlo error had not disappeared and hence was keeping the rate at the same √n speed.
The core proof in the paper leading to the 7/12 convergence rate relies on a mathematical result of Sun and Wu (2009) that a certain rate of regularisation of the function of interest leads to an average variance of order 1/6. I have no reason to mistrust the result (and anyway did not check the original paper), but I am still puzzled by the fact that it almost immediately leads to the control variate estimator having a smaller order variance (or at least variability). On average or in probability. (I am also uncertain on the possibility to interpret the boxplot figures as establishing super-√n speed.)
Another thing I cannot truly grasp is how the control functional estimator of (7) can be both a mere linear recombination of individual unbiased estimators of the target expectation and an improvement in the variance rate. I acknowledge that the coefficients of the matrices are functions of the sample simulated from the target density but still…
Another source of inner puzzlement is the choice of the kernel in the paper, which seems too simple to be able to cover all problems despite being used in every illustration there. I see the kernel as centred at zero, which means a central location must be know, decreasing to zero away from this centre, so possibly missing aspects of the integrand that are too far away, and isotonic in the reference norm, which also seems to preclude some settings where the integrand is not that compatible with the geometry.
I am equally nonplussed by the existence of a deterministic bound on the error, although it is not completely deterministic, depending on the values of the reproducible kernel at the points of the sample. Does it imply anything restrictive on the function to be integrated?
A side remark about the use of intractable in the paper is that, given the development of a whole new branch of computational statistics handling likelihoods that cannot be computed at all, intractable should possibly be reserved for such higher complexity models.
## likelihood-free Bayesian inference on the minimum clinically important difference
Posted in Books, Statistics, University life with tags , , , , , on January 20, 2015 by xi'an
Last week, Likelihood-free Bayesian inference on the minimum clinically important difference was arXived by Nick Syring and Ryan Martin and I read it over the weekend, slowly coming to the realisation that their [meaning of] “likelihood free” was not my [meaning of] “likelihood free”, namely that it has nothing to do with ABC! The idea therein is to create a likelihood out of a loss function, in the spirit of Bassiri, Holmes and Walker, the loss being inspired here by a clinical trial concept, the minimum clinically important difference, defined as
$\theta^* = \min_\theta\mathbb{P}(Y\ne\text{sign}(X-\theta))$
which defines a loss function per se when considering the empirical version. In clinical trials, Y is a binary outcome and X a vector of explanatory variables. This model-free concept avoids setting a joint distribution on the pair (X,Y), since creating a distribution on a large vector of covariates is always an issue. As a marginalia, the authors actually mention our MCMC book in connection with a logistic regression (Example 7.11) and for a while I thought we had mentioned MCID therein, realising later it was a standard description of MCMC for logistic models.
The central and interesting part of the paper is obviously defining the likelihood-free posterior as
$\pi_n(\theta) \propto \exp\{-n L_n(\theta) \}\pi(\theta)$
The authors manage to obtain the rate necessary for the estimation to be asymptotically consistent, which seems [to me] to mean that a better representation of the likelihood-free posterior should be
$\pi_n(\theta) \propto \exp\{-n^{-2/5} L_n(\theta) \}\pi(\theta)$
(even though this rescaling does not appear verbatim in the paper). This is quite an interesting application of the concept developed by Bissiri, Holmes and Walker, even though it also illustrates the difficulty of defining a specific prior, given that the minimised target above can be transformed by an arbitrary increasing function. And the mathematical difficulty in finding a rate.
## control functionals for Monte Carlo integration
Posted in Books, Statistics, University life with tags , , , , , on October 21, 2014 by xi'an
This new arXival by Chris Oates, Mark Girolami, and Nicolas Chopin (warning: they all are colleagues & friends of mine!, at least until they read those comments…) is a variation on control variates, but with a surprising twist namely that the inclusion of a control variate functional may produce a sub-root-n (i.e., faster than √n) convergence rate in the resulting estimator. Surprising as I did not know one could get to sub-root-n rates..! Now I had forgotten that Anne Philippe and I used the score in an earlier paper of ours, as a control variate for Riemann sum approximations, with faster convergence rates, but this is indeed a new twist, in particular because it produces an unbiased estimator.
The control variate writes
$\psi_\phi (x) = \nabla_x \cdot \phi(x) + \phi(x)\cdot \nabla \pi(x)$
where π is the target density and φ is a free function to be optimised. (Under the constraint that πφ is integrable. Then the expectation of ψφ is indeed zero.) The “explanation” for the sub-root-n behaviour is that ψφ is chosen as an L2 regression. When looking at the sub-root-n convergence proof, the explanation is more of a Rao-Blackwellisation type, assuming a first level convergent (or presistent) approximation to the integrand [of the above form ψφ can be found. The optimal φ is the solution of a differential equation that needs estimating and the paper concentrates on approximating strategies. This connects with Antonietta Mira’s zero variance control variates, but in a non-parametric manner, adopting a Gaussian process as the prior on the unknown φ. And this is where the huge innovation in the paper resides, I think, i.e. in assuming a Gaussian process prior on the control functional and in managing to preserve unbiasedness. As in many of its implementations, modelling by Gaussian processes offers nice features, like ψφ being itself a Gaussian process. Except that it cannot be shown to lead to presistency on a theoretical basis. Even though it appears to hold in the examples of the paper. Apart from this theoretical difficulty, the potential hardship with the method seems to be in the implementation, as there are several parameters and functionals to be calibrated, hence calling for cross-validation which may often be time-consuming. The gains are humongous, so the method should be adopted whenever the added cost in implementing it is reasonable, cost which evaluation is not clearly provided by the paper. In the toy Gaussian example where everything can be computed, I am surprised at the relatively poor performance of a Riemann sum approximation to the integral, wondering at the level of quadrature involved therein. The paper also interestingly connects with O’Hagan’s (1991) Bayes-Hermite [polynomials] quadrature and quasi-Monte Carlo [obviously!].
## rate of convergence for ABC
Posted in Statistics, University life with tags , , , , on November 19, 2013 by xi'an
Barber, Voss, and Webster recently posted and arXived a paper entitled The Rate of Convergence for Approximate Bayesian Computation. The paper is essentially theoretical and establishes the optimal rate of convergence of the MSE—for approximating a posterior moment—at a rate of 2/(q+4), where q is the dimension of the summary statistic, associated with an optimal tolerance in n-1/4. I was first surprised at the role of the dimension of the summary statistic, but rationalised it as being the dimension where the non-parametric estimation takes place. I may have read the paper too quickly as I did not spot any link with earlier convergence results found in the literature: for instance, Blum (2010, JASA) links ABC with standard kernel density non-parametric estimation and find a tolerance (bandwidth) of order n-1/q+4 and an MSE of order 2/(q+4) as well. Similarly, Biau et al. (2013, Annales de l’IHP) obtain precise convergence rates for ABC interpreted as a k-nearest-neighbour estimator. And, as already discussed at length on this blog, Fearnhead and Prangle (2012, JRSS Series B) derive rates similar to Blum’s with a tolerance of order n-1/q+4 for the regular ABC and of order n-1/q+2 for the noisy ABC | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 4, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9052944183349609, "perplexity": 774.7288719926448}, "config": {"markdown_headings": true, "markdown_code": false, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2023-06/segments/1674764499888.62/warc/CC-MAIN-20230131154832-20230131184832-00093.warc.gz"} |
https://blog.csdn.net/hewei0241/article/details/7733067 | # Earth mover's distance
In computer science, the earth mover's distance (EMD) is a measure of the distance between two probability distributions over a region D. In mathematics, this is known as the Wasserstein metric. Informally, if the distributions are interpreted as two different ways of piling up a certain amount of dirt over the region D, the EMD is the minimum cost of turning one pile into the other; where the cost is assumed to be amount of dirt moved times the distance by which it is moved [1].
The above definition is valid only if the two distributions have the same integral (informally, if the two piles have the same amount of dirt), as in normalized histograms orprobability density functions. In that case, the EMD is equivalent to the 1st Mallows distance or 1st Wasserstein distance between the two distributions [2] [3].
## Extensions
Some applications may require the comparison of distributions with different total masses. One approach is to allow for a partial match, where dirt from the most massive distribution is rearranged to make the least massive, and any leftover "dirt" is discarded at no cost. Under this approach, the EMD is no longer a true distance between distributions. Another approach is to allow for mass to be created or destroyed, on a global and/or local level, as an alternative to transportation, but with a cost penalty. In that case one must specify a real parameter σ, the ratio between the cost of creating or destroying one unit of "dirt", and the cost of transporting it by a unit distance. This is equivalent to minimizing the sum of the earth moving cost plus σ times the L1 distance between the rearranged pile and the second distribution.
## Computing the EMD
If the domain D is discrete, the EMD can be computed by solving an instance transportation problem, which can be solved by the so-called Hungarian algorithm. In particular, ifD is a one-dimensional array of "bins" the EMD can be efficiently computed by scanning the array and keeping track of how much dirt needs to be transported between consecutive bins.
References
2. ^ Elizaveta Levina; Peter Bickel (2001). "The EarthMover’s Distance is the Mallows Distance: Some Insights from Statistics". Proceedings of ICCV 2001 (Vancouver, Canada): 251–256.
3. ^ C. L. Mallows (1972). "A note on asymptotic joint normality". Annals of Mathematical Statistics 43 (2): 508–515. doi:10.1214/aoms/1177692631.
4. a b S. Peleg; M. Werman, and H. Rom (1989). "A unified approach to the change of resolution: Space and gray-level". IEEE Transactions on Pattern Analysis and Machine Intelligence 11: 739–742.doi:10.1109/34.192468.
5. ^ "Mémoire sur la théorie des déblais et des remblais". Histoire de l’Académie Royale des Science, Année 1781, avec les Mémoires de Mathématique et de Physique. 1781.
6. ^ J. Stolfi, personal communication to L. J. Guibas, 1994
7. ^ Yossi Rubner; Carlo Tomasi, Leonidas J. Guibas (1998). "A Metric for Distributions with Applications to Image Databases". Proceedings ICCV 1998: 59–66.
————罗方炜译
http://en.wikipedia.org/wiki/Transportation_problem
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http://elib.mi.sanu.ac.rs/pages/browse_issue.php?db=flmt&rbr=71&start=10 | eLibrary of Mathematical Instituteof the Serbian Academy of Sciences and Arts
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FilomatPublisher: Faculty of Sciences and Mathematics, NišISSN: 0354-5180Issue: 29_7Date: 2015Journal Homepage
Improved Chen Inequality of Sasakian Space Forms With the Tanaka--Webster Connection 1525 - 1533 Chul Woo Lee, Jae Won Lee and Dae Won Yoon
AbstractKeywords: Tanaka-Webster connection; pseudo-mean curvature; pseudo-sectional curvature; pseudo-Ricci curvatureMSC: 53C25; 53C40; 53C40DOI: 10.2298/FIL1507525L
Estimates of $(1+x)^{1/x}$ Involved in Carleman's Inequality and Keller's Limit 1535 - 1539 Cristinel Mortici and X.-J. Jang
AbstractKeywords: constant e; Carleman's inequality; Keller's limit; approximationsMSC: 26A09 33B10; 26D99DOI: 10.2298/FIL1507535M
On Strong Limit Theorems for Negatively Superadditive Dependent Random Variables 1541 - 1547 Yongjun Zhang
AbstractKeywords: negatively superadditive dependent; strong law of large numbers; Jamision weighted sums; strong convergence propertyMSC: 60F15; 60E15DOI: 10.2298/FIL1507541Z
A Generalization of ĆIrić Fixed Point Theorems 1549 - 1556 Poom Kumam, Nguyen Van Dung and Kanokwan Sitthithakerngkiet
AbstractKeywords: Ćirić fixed point; metric spaceMSC: 47H10; 54H25 54D99; 54E99DOI: 10.2298/FIL1507549K
Hessenberg Matrices and the Generalized Fibonacci--Narayana Sequence 1557 - 1563 José L. Ramírez
AbstractKeywords: generalized Fibonacci-Narayana sequence; Hessenberg matrix; permanentMSC: 15A15 11B39DOI: 10.2298/FIL1507557R
On the Fractional Hermite--Hadamard Type Inequalities for $(\alpha,m)$-Logarithmically Convex Functions 1565 - 1580 Jinrong Wang, Yumei Liao and Jianhua Deng
AbstractKeywords: fractional Hermite-Hadamard inequalities; Riemann-Liouville fractional integrals; $(\alpha;m)$-logarithmically convex functionsMSC: 26A33; 26A51; 26D15DOI: 10.2298/FIL1507565W
On the Univalence of Two General Integral Operators 1581 - 1586 Erhan Deniz
AbstractKeywords: analytic functions; open unit disk; univalent functions; univalence conditions; integral operatorsMSC: 30C45 30C80DOI: 10.2298/FIL1507581D
Some Equivalent Characterizations of Inner Product Spaces and Their Consequences 1587 - 1599 Dan Ştefan Marinescu, Mihai Monea, Mihai Opincariu and Marian Stroe
AbstractKeywords: normed spaces; inner product spacesMSC: 46C15DOI: 10.2298/FIL1507587M
Coefficient Estimates for Three Generalized Classes of Meromorphic and Bi-Univalent Functions 1601 - 1612 Hai-Gen Xiao and Qing-Hua Xu
AbstractKeywords: meromorphic functions; bi-univalent functions; $\beta$-spirallike functions of order $\alpha$; Bazilevič functions of type $\beta$ and order $\alpha$; $\lambda$-convex functions of order $\alpha$MSC: 30C45 30C50DOI: 10.2298/FIL1507601X
Fixed Points of Integral Type Contractions in Uniform Spaces 1613 - 1621 Aris Aghanians and Kourosh Nourouzi
AbstractKeywords: separated uniform space; integral type p-G-contraction; fixed pointMSC: 47H10 05C40DOI: 10.2298/FIL1507613A
Article page: <<123>>
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https://www.soihub.org/resources/journal-papers/estimation-of-entropy-rate-and-renyi-entropy-rate-for-markov-chains/ | • ### Estimation of entropy rate and Renyi entropy rate for Markov chains
• Peer Reviewed Conference Papers reported 2016
S. Kamath and S. Verdu. "Estimation of entropy rate and Renyi entropy rate for Markov chains", Proc. 2016 IEEE Int. Symposium on Information Theory, pp. 685?689. Barcelona, Spain, July 11-15, 2016 (PDF)
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