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https://en.wikipedia.org/wiki/Blind%20wine%20tasting
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Blinded wine tasting is wine tasting undertaken in circumstances in which the tasters are kept unaware of the wines' identities. The blind approach is routine for wine professionals (wine tasters, sommeliers and others) who wish to ensure impartiality in the judgment of the quality of wine during wine competitions or in the evaluation of a sommelier for professional certification. More recently wine scientists (physiologists, psychologists, food chemists and others) have used blinded tastings to explore the objective parameters of the human olfactory system as they apply to the ability of wine drinkers (both wine professionals and ordinary consumers) to identify and characterize the extraordinary variety of compounds that contribute to a wine’s aroma. Similarly, economists testing hypotheses relating to the wine market have used the technique in their research. Some blinded trials among wine consumers have indicated that people can find nothing in a wine's aroma or taste to distinguish between ordinary and pricey brands. Academic research on blinded wine tastings have also cast doubt on the ability of professional tasters to judge wines consistently.
Technique
Blind tasting, at a minimum, involves denying taster(s) the ability to see the wine label or wine bottle shape. Informal tastings may simply conceal the bottles in a plain paper bag. More exacting competitions or evaluations utilize more stringent procedures, including safeguards against cheating. For example, the wine may be tasted from a black wine glass to mask the color .
Biases
A taster's judgment can be prejudiced by knowing details of a wine, such as geographic origin, price, reputation, color, or other considerations.
Scientific research has long demonstrated the power of suggestion in perception as well as the strong effects of expectancies. For example, people expect more expensive wine to have more desirable characteristics than less expensive wine. When given wine that they are falsely told is e
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https://en.wikipedia.org/wiki/P-Cymene
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p-Cymene is a naturally occurring aromatic organic compound. It is classified as an alkylbenzene related to monocyclic monoterpenes. Its structure consists of a benzene ring para-substituted with a methyl group and an isopropyl group. p-Cymene is insoluble in water, but miscible with organic solvents.
Isomers and production
In addition to p-cymene, two less common geometric isomers are o-cymene, in which the alkyl groups are ortho-substituted, and m-cymene, in which they are meta-substituted. p-Cymene is the only natural isomer, as expected from the terpene rule. All three isomers form the group of cymenes.
Cymene is also produced by alkylation of toluene with propene.
Related compounds
It is a constituent of a number of essential oils, most commonly the oil of cumin and thyme. Significant amounts are formed in sulfite pulping process from the wood terpenes.
p-Cymene is a common ligand for ruthenium. The parent compound is [(η6-cymene)RuCl2]2. This half-sandwich compound is prepared by the reaction of ruthenium trichloride with the terpene α-phellandrene. The osmium complex is also known.
Hydrogenation gives the saturated derivative p-menthane.
References
Flavors
Alkylbenzenes
C4-Benzenes
Monoterpenes
Isopropyl compounds
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https://en.wikipedia.org/wiki/Mechanical%20impedance
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Mechanical impedance is a measure of how much a structure resists motion when subjected to a harmonic force. It relates forces with velocities acting on a mechanical system. The mechanical impedance of a point on a structure is the ratio of the force applied at a point to the resulting velocity at that point.
Mechanical impedance is the inverse of mechanical admittance or mobility. The mechanical impedance is a function of the frequency of the applied force and can vary greatly over frequency. At resonance frequencies, the mechanical impedance will be lower, meaning less force is needed to cause a structure to move at a given velocity. A simple example of this is pushing a child on a swing. For the greatest swing amplitude, the frequency of the pushes must be near the resonant frequency of the system.
Where, is the force vector, is the velocity vector, is the impedance matrix and is the angular frequency.
Mechanical impedance is the ratio of a potential (e.g., force) to a flow (e.g., velocity) where the arguments of the real (or imaginary) parts of both increase linearly with time. Examples of potentials are: force, sound pressure, voltage, temperature. Examples of flows are: velocity, volume velocity, current, heat flow. Impedance is the reciprocal of mobility. If the potential and flow quantities are measured at the same point then impedance is referred as driving point impedance; otherwise, transfer impedance.
Resistance - the real part of an impedance.
Reactance - the imaginary part of an impedance.
See also
Acoustic impedance
Frequency response
Impedance analogy
Linear response function
References
Physical quantities
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https://en.wikipedia.org/wiki/Landscape%20of%20Geometry
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Landscape of Geometry was an educational television show that illustrated the principles and applications of geometry. The series was produced and broadcast by TVOntario in 1982–83 and was hosted by David Stringer. A videotape edition of the show was produced in 1992 by Films for the Humanities.
Episode list
Eight episodes were produced. They were:
"The Shape of Things"
"It's Rude to Point"
"Lines That Cross"
"Lines That Don't Cross"
"Up, Down, and Sideways"
"Trussworthy"
"Cracked Up"
"The Range of Change"
All episodes were 15 minutes in length.
References
TVO original programming
1980s Canadian children's television series
Mathematics education television series
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https://en.wikipedia.org/wiki/Barium%20titanate
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Barium titanate (BTO) is an inorganic compound with chemical formula BaTiO3. Barium titanate appears white as a powder and is transparent when prepared as large crystals. It is a ferroelectric, pyroelectric, and piezoelectric ceramic material that exhibits the photorefractive effect. It is used in capacitors, electromechanical transducers and nonlinear optics.
Structure
The solid exists in one of four polymorphs depending on temperature. From high to low temperature, these crystal symmetries of the four polymorphs are cubic, tetragonal, orthorhombic and rhombohedral crystal structure. All of these phases exhibit the ferroelectric effect apart from the cubic phase. The high temperature cubic phase is easiest to describe, as it consists of regular corner-sharing octahedral TiO6 units that define a cube with O vertices and Ti-O-Ti edges. In the cubic phase, Ba2+ is located at the center of the cube, with a nominal coordination number of 12. Lower symmetry phases are stabilized at lower temperatures and involve movement of the Ti4+ to off-center positions. The remarkable properties of this material arise from the cooperative behavior of the Ti4+ distortions.
Above the melting point, the liquid has a remarkably different local structure to the solid forms, with the majority of Ti4+ coordinated to four oxygen, in tetrahedral TiO4 units, which coexist with more highly coordinated units.
Production and handling properties
Barium titanate can be synthesized by the relatively simple sol–hydrothermal method.
Barium titanate can also be manufactured by heating barium carbonate and titanium dioxide. The reaction proceeds via liquid phase sintering. Single crystals can be grown at around 1100 °C from molten potassium fluoride. Other materials are often added as dopants, e.g., Sr to form solid solutions with strontium titanate. It reacts with nitrogen trichloride and produces a greenish or gray mixture; the ferroelectric properties of the mixture are still present i
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https://en.wikipedia.org/wiki/Symmetric%20derivative
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In mathematics, the symmetric derivative is an operation generalizing the ordinary derivative. It is defined as
The expression under the limit is sometimes called the symmetric difference quotient. A function is said to be symmetrically differentiable at a point x if its symmetric derivative exists at that point.
If a function is differentiable (in the usual sense) at a point, then it is also symmetrically differentiable, but the converse is not true. A well-known counterexample is the absolute value function , which is not differentiable at , but is symmetrically differentiable here with symmetric derivative 0. For differentiable functions, the symmetric difference quotient does provide a better numerical approximation of the derivative than the usual difference quotient.
The symmetric derivative at a given point equals the arithmetic mean of the left and right derivatives at that point, if the latter two both exist.
Neither Rolle's theorem nor the mean-value theorem hold for the symmetric derivative; some similar but weaker statements have been proved.
Examples
The absolute value function
For the absolute value function , using the notation for the symmetric derivative, we have at that
Hence the symmetric derivative of the absolute value function exists at and is equal to zero, even though its ordinary derivative does not exist at that point (due to a "sharp" turn in the curve at ).
Note that in this example both the left and right derivatives at 0 exist, but they are unequal (one is −1, while the other is +1); their average is 0, as expected.
The function x−2
For the function , at we have
Again, for this function the symmetric derivative exists at , while its ordinary derivative does not exist at due to discontinuity in the curve there. Furthermore, neither the left nor the right derivative is finite at 0, i.e. this is an essential discontinuity.
The Dirichlet function
The Dirichlet function, defined as
has a symmetric derivative at every ,
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https://en.wikipedia.org/wiki/Metabolic%20rift
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Metabolic rift is Karl Marx's key conception of ecological crisis tendencies under capitalism, or in Marx's own words, it is the "irreparable rift in the interdependent process of social metabolism". Marx theorized a rupture in the metabolic interaction between humanity and the rest of nature emanating from capitalist agricultural production and the growing division between town and country.
According to John Bellamy Foster, who coined the term, metabolic rift is the development of Marx's earlier work in the Economic and Philosophical Manuscripts on species-being and the relationship between humans and nature. Metabolism is Marx's "mature analysis of the alienation of nature" and presents "a more solid—and scientific—way in which to depict the complex, dynamic interchange between human beings and nature, resulting from human labor."
As opposed to those who have attributed to Marx a disregard for nature and responsibility for the environmental problems of the Soviet Union and other purportedly communist states, Foster sees in the theory of metabolic rift evidence of Marx's ecological perspective. The theory of metabolic rift "enable[ed] [Marx] to develop a critique of environmental degradation that anticipated much of present-day ecological thought", including questions of sustainability as well as the limits of agricultural production using concentrated animal feeding operations. Researchers building on the original Marxist concept have developed other similar terms like carbon rift.
Origins
Soil exhaustion and agricultural revolutions
Marx's writings on metabolism were developed during England's "second" agricultural revolution (1815–1880), a period which was characterized by the development of soil chemistry and the growth of the use of chemical fertilizer. The depletion of soil fertility, or "soil exhaustion", had become a key concern for capitalist society, and demand for fertilizer was such that Britain and other powers initiated explicit policies for the
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https://en.wikipedia.org/wiki/Hibernation%20%28computing%29
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Hibernation (also known as suspend to disk, or Safe Sleep on Macintosh computers) in computing is powering down a computer while retaining its state. When hibernation begins, the computer saves the contents of its random access memory (RAM) to a hard disk or other non-volatile storage. When the computer is turned on the RAM is restored and the computer is exactly as it was before entering hibernation. Hibernation was first implemented in 1992 and patented by Compaq Computer Corporation in Houston, Texas. Microsoft's Windows 10 employs a type of hibernation (fast startup) by default when shutting down.
Uses
After hibernating, the hardware is powered down like a regular shutdown. The system can have a total loss of power for an indefinite length of time and then resume to the original state. Hibernation is mostly used in laptops, which have limited battery power available. It can be set to happen automatically on a low battery alarm. Most desktops also support hibernation, mainly as a general energy saving measure and allows for replacement of a removable battery quickly. Google and Apple mobile hardware (Android, Chromebooks, iOS) do not support hibernation. Apple hardware using macOS calls hibernation Safe Sleep.
Comparison to sleep mode
Many systems support a low-power sleep mode in which the processing functions of the machine are lowered, using a trickle of power to preserve the contents of RAM and support waking up. Instantaneous resumption is one of the advantages of sleep mode over hibernation. A hibernated system must start up and read data from permanent storage and then transfer that back to RAM, which takes longer and depends on the speed of the permanent storage device, often much slower than RAM memory. A system in sleep mode only needs to power up the CPU and display, which is almost instantaneous. On the other hand, a system in sleep mode still consumes power to keep the data in the RAM. Detaching power from a system in sleep mode results in da
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https://en.wikipedia.org/wiki/Polyfuse%20%28PROM%29
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A polyfuse is a one-time-programmable memory component used in semiconductor circuits for storing unique data like chip identification numbers or memory repair data, but more usually small to medium volume production of read only memory devices or microcontroller chips. They were also used as to permit programming of Programmable Array Logic. The use of fuses allowed the device to be programmed electrically some time after it was manufactured and sealed into its packaging. Earlier fuses had to be blown using a laser at the time memory was manufactured. Polyfuses were developed to replace the earlier nickel-chromium (ni-chrome) fuses. Because ni-chrome contains nickel, the ni-chrome fuse, once blown had a tendency to grow back and render the memory unusable.
History
The first polyfuses consisted of a polysilicon line, which was programmed by applying a high (10V-15V) voltage across the device. The resultant current physically alters the device and increases its electrical resistance. This change in resistance can be detected and registered as a logical zero. An unprogrammed polyfuse would be registered as a logical one. These early devices had severe drawbacks like a high programming voltage and unreliability of the programmed devices.
Modern polyfuses
Modern polyfuses consist of a silicided polysilicon line, which is also programmed by applying a voltage across the device. Again, the resultant current permanently alters the resistance. The silicide layer covering the polysilicon line reduces its resistance (before programming), allowing the use of much lower programming voltages (1.8V–3.3V). Polyfuses have been shown to reliably store programmed data and can be programmed at high speed. Programming speeds of 100ns have been reported.
See also
Programmable read-only memory
References
References
Resistive components
Non-volatile memory
Computer memory
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https://en.wikipedia.org/wiki/Statistical%20literacy
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Statistical literacy is the ability to understand and reason with statistics and data. The abilities to understand and reason with data, or arguments that use data, are necessary for citizens to understand material presented in publications such as newspapers, television, and the Internet. However, scientists also need to develop statistical literacy so that they can both produce rigorous and reproducible research and consume it. Numeracy is an element of being statistically literate and in some models of statistical literacy, or for some populations (e.g., students in kindergarten through 12th grade/end of secondary school), it is a prerequisite skill. Being statistically literate is sometimes taken to include having the abilities to both critically evaluate statistical material and appreciate the relevance of statistically-based approaches to all aspects of life in general or to the evaluating, design, and/or production of scientific work.
Promoting statistical literacy
Each day people are inundated with statistical information from advertisements ("4 out of 5 dentists recommend"), news reports ("opinion poll show the incumbent leading by four points"), and even general conversation ("half the time I don't know what you're talking about"). Experts and advocates often use numerical claims to bolster their arguments, and statistical literacy is a necessary skill to help one decide what experts mean and which advocates to believe. This is important because statistics can be made to produce misrepresentations of data that may seem valid. The aim of statistical literacy proponents is to improve the public understanding of numbers and figures.
Health decisions are often manifest as statistical decision problems but few doctors or patients are well equipped to engage with these data.
Results of opinion polling are often cited by news organizations, but the quality of such polls varies considerably. Some understanding of the statistical technique of sampling is nec
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https://en.wikipedia.org/wiki/Toxicofera
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Toxicofera (Greek for "those who bear toxins") is a proposed clade of scaled reptiles (squamates) that includes the Serpentes (snakes), Anguimorpha (monitor lizards, gila monster, and alligator lizards) and Iguania (iguanas, agamas, and chameleons). Toxicofera contains about 4,600 species, (nearly 60%) of extant Squamata. It encompasses all venomous reptile species, as well as numerous related non-venomous species. There is little morphological evidence to support this grouping; however, it has been recovered by all molecular analyses as of 2012.
Cladistics
Toxicofera combines the following groups from traditional classification:
Suborder Serpentes (snakes)
Suborder Iguania (iguanas, agamid lizards, chameleons, etc.)
Suborder Anguimorpha, consisting of:
Family Varanidae (monitor lizards)
Family Lanthanotidae (earless monitor lizard)
Family Anguidae (alligator lizards, glass lizards, etc.)
Family Helodermatidae (Gila monster and Mexican beaded lizard)
Family Shinisauridae (Chinese crocodile lizard)
Family Xenosauridae (knob-scaled lizards)
The relationship between these extant groups and a couple of extinct taxa are shown in the following cladogram, which is based on Reeder et al. (2015; Fig. 1).
Venom
Venom in squamates has historically been considered a rarity; while it has been known in Serpentes since ancient times, the actual percentage of snake species considered venomous was relatively small (around 25%). Of the approximately 2,650 species of advanced snakes (Caenophidia), only the front-fanged species (~650) were considered venomous by the anthropocentric definition.
Following the classification of Helodermatidae in the 19th century, their venom was thought to have developed independently. In snakes, the venom gland is in the upper jaw, but in helodermatids, it is found in the lower jaw. The origin of venom in squamates was thus considered relatively recent in evolutionary terms and the result of convergent evolution among the seemingly-polyph
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https://en.wikipedia.org/wiki/Small%20Latin%20squares%20and%20quasigroups
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Latin squares and quasigroups are equivalent mathematical objects, although the former has a combinatorial nature while the latter is more algebraic. The listing below will consider the examples of some very small orders, which is the side length of the square, or the number of elements in the equivalent quasigroup.
The equivalence
Given a quasigroup with elements, its Cayley table (almost universally called its multiplication table) is an table that includes borders; a top row of column headers and a left column of row headers. Removing the borders leaves an array that is a Latin square. This process can be reversed, starting with a Latin square, introduce a bordering row and column to obtain the multiplication table of a quasigroup. While there is complete arbitrariness in how this bordering is done, the quasigroups obtained by different choices are sometimes equivalent in the sense given below.
Isotopy and isomorphism
Two Latin squares, 1 and 2 of size are isotopic if there are three bijections from the rows, columns and symbols of 1 onto the rows, columns and symbols of 2, respectively, that map 1 to 2. Isotopy is an equivalence relation and the equivalence classes are called isotopy classes.
A stronger form of equivalence exists. Two Latin squares, 1 and 2 of side with common symbol set that is also the index set for the rows and columns of each square, are isomorphic if there is a bijection such that for all , in . An alternate way to define isomorphic Latin squares is to say that a pair of isotopic Latin squares are isomorphic if the three bijections used to show that they are isotopic are, in fact, equal. Isomorphism is also an equivalence relation and its equivalence classes are called isomorphism classes.
An alternate representation of a Latin square is given by an orthogonal array. For a Latin square of order this is an 2 × 3 matrix with columns labeled , and and whose rows correspond to a single position of the Latin square, namely, the
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https://en.wikipedia.org/wiki/Symmetrically%20continuous%20function
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In mathematics, a function is symmetrically continuous at a point x if
The usual definition of continuity implies symmetric continuity, but the converse is not true. For example, the function is symmetrically continuous at , but not continuous.
Also, symmetric differentiability implies symmetric continuity, but the converse is not true just like usual continuity does not imply differentiability.
The set of the symmetrically continuous functions, with the usual scalar multiplication can be easily shown to have the structure of a vector space over , similarly to the usually continuous functions, which form a linear subspace within it.
References
Differential calculus
Theory of continuous functions
Types of functions
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https://en.wikipedia.org/wiki/Second%20derivative
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In calculus, the second derivative, or the second-order derivative, of a function is the derivative of the derivative of . Informally, the second derivative can be phrased as "the rate of change of the rate of change"; for example, the second derivative of the position of an object with respect to time is the instantaneous acceleration of the object, or the rate at which the velocity of the object is changing with respect to time. In Leibniz notation:
where is acceleration, is velocity, is time, is position, and d is the instantaneous "delta" or change. The last expression is the second derivative of position () with respect to time.
On the graph of a function, the second derivative corresponds to the curvature or concavity of the graph. The graph of a function with a positive second derivative is upwardly concave, while the graph of a function with a negative second derivative curves in the opposite way.
Second derivative power rule
The power rule for the first derivative, if applied twice, will produce the second derivative power rule as follows:
Notation
The second derivative of a function is usually denoted . That is:
When using Leibniz's notation for derivatives, the second derivative of a dependent variable with respect to an independent variable is written
This notation is derived from the following formula:
Example
Given the function
the derivative of is the function
The second derivative of is the derivative of , namely
Relation to the graph
Concavity
The second derivative of a function can be used to determine the concavity of the graph of . A function whose second derivative is positive will be concave up (also referred to as convex), meaning that the tangent line will lie below the graph of the function. Similarly, a function whose second derivative is negative will be concave down (also simply called concave), and its tangent lines will lie above the graph of the function.
Inflection points
If the second derivative of a
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https://en.wikipedia.org/wiki/Oscillatory%20integral
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In mathematical analysis an oscillatory integral is a type of distribution. Oscillatory integrals make rigorous many arguments that, on a naive level, appear to use divergent integrals. It is possible to represent approximate solution operators for many differential equations as oscillatory integrals.
Definition
An oscillatory integral is written formally as
where and are functions defined on with the following properties:
The function is real-valued, positive-homogeneous of degree 1, and infinitely differentiable away from . Also, we assume that does not have any critical points on the support of . Such a function, is usually called a phase function. In some contexts more general functions are considered and still referred to as phase functions.
The function belongs to one of the symbol classes for some . Intuitively, these symbol classes generalize the notion of positively homogeneous functions of degree . As with the phase function , in some cases the function is taken to be in more general, or just different, classes.
When , the formal integral defining converges for all , and there is no need for any further discussion of the definition of . However, when , the oscillatory integral is still defined as a distribution on , even though the integral may not converge. In this case the distribution is defined by using the fact that may be approximated by functions that have exponential decay in . One possible way to do this is by setting
where the limit is taken in the sense of tempered distributions. Using integration by parts, it is possible to show that this limit is well defined, and that there exists a differential operator such that the resulting distribution acting on any in the Schwartz space is given by
where this integral converges absolutely. The operator is not uniquely defined, but can be chosen in such a way that depends only on the phase function , the order of the symbol , and . In fact, given any integer , it is pos
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https://en.wikipedia.org/wiki/Photodegradation
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Photodegradation is the alteration of materials by light. Commonly, the term is used loosely to refer to the combined action of sunlight and air, which cause oxidation and hydrolysis. Often photodegradation is intentionally avoided, since it destroys paintings and other artifacts. It is, however, partly responsible for remineralization of biomass and is used intentionally in some disinfection technologies. Photodegradation does not apply to how materials may be aged or degraded via infrared light or heat, but does include degradation in all of the ultraviolet light wavebands.
Applications
Foodstuffs
The protection of food from photodegradation is very important. Some nutrients, for example, are affected by degradation when exposed to sunlight. In the case of beer, UV radiation causes a process that entails the degradation of hop bitter compounds to 3-methyl-2-buten-1-thiol and therefore changes the taste. As amber-colored glass has the ability to absorb UV radiation, beer bottles are often made from such glass to prevent this process.
Paints, inks, and dyes
Paints, inks, and dyes that are organic are more susceptible to photodegradation than those that are not. Ceramics are almost universally colored with non-organic origin materials so as to allow the material to resist photodegradation even under the most relentless conditions, maintaining its color.
Pesticides and herbicides
The photodegradation of pesticides is of great interest because of the scale of agriculture and the intensive use of chemicals. Pesticides are however selected in part not to photodegrade readily in sunlight in order to allow them to exert their biocidal activity. Thus, more modalities are implemented to enhance their photodegradation, including the use of photosensitizers, photocatalysts (e.g., titanium dioxide), and the addition of reagents such as hydrogen peroxide that would generate hydroxyl radicals that would attack the pesticides.
Pharmaceuticals
The photodegradation of pharma
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https://en.wikipedia.org/wiki/Computer%20network%20programming
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Computer network programming involves writing computer programs that enable processes to communicate with each other across a computer network.
Connection-oriented and connectionless communications
Very generally, most of communications can be divided into connection-oriented, and connectionless. Whether a communication is connection-oriented or connectionless, is defined by the communication protocol, and not by . Examples of the connection-oriented protocols include and , and examples of connectionless protocols include , "raw IP", and .
Clients and servers
For connection-oriented communications, communication parties usually have different roles. One party is usually waiting for incoming connections; this party is usually referred to as "server". Another party is the one which initiates connection; this party is usually referred to as "client".
For connectionless communications, one party ("server") is usually waiting for an incoming packet, and another party ("client") is usually understood as the one which sends an unsolicited packet to "server".
Popular protocols and APIs
Network programming traditionally covers different layers of OSI/ISO model (most of application-level programming belongs to L4 and up). The table below contains some examples of popular protocols belonging to different OSI/ISO layers, and popular APIs for them.
See also
Software-defined networking
Infrastructure as code
Site reliability engineering
DevOps
References
W. Richard Stevens: UNIX Network Programming, Volume 1, Second Edition: Networking APIs: Sockets and XTI, Prentice Hall, 1998,
Computer programming
Inter-process communication
Computer networks
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https://en.wikipedia.org/wiki/ECC%20patents
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Patent-related uncertainty around elliptic curve cryptography (ECC), or ECC patents, is one of the main factors limiting its wide acceptance. For example, the OpenSSL team accepted an ECC patch only in 2005 (in OpenSSL version 0.9.8), despite the fact that it was submitted in 2002.
According to Bruce Schneier as of May 31, 2007, "Certicom certainly can claim ownership of ECC. The algorithm was developed and patented by the company's founders, and the patents are well written and strong. I don't like it, but they can claim ownership." Additionally, NSA has licensed MQV and other ECC patents from Certicom in a US$25 million deal for NSA Suite B algorithms. (ECMQV is no longer part of Suite B.)
However, according to RSA Laboratories, "in all of these cases, it is the implementation technique that is patented, not the prime or representation, and there are alternative, compatible implementation techniques that are not covered by the patents." Additionally, Daniel J. Bernstein has stated that he is "not aware of" patents that cover the Curve25519 elliptic curve Diffie–Hellman algorithm or its implementation. , published in February 2011, documents ECC techniques, some of which were published so long ago that even if they were patented, any such patents for these previously published techniques would now be expired.
Known patents
Certicom holds a patent on efficient GF(2n) multiplication in normal basis representation; expired in 2016.
Certicom holds multiple patents which cover the MQV (Menezes, Qu, and Vanstone) key agreement technique:
expired in 2015
expired in 2015
expired in 2015
expired in 2015
expired in 2017
/EP0739105B1 expired in 2016
Certicom holds on validating the key exchange messages using ECC to prevent a man-in-the-middle attack, which expired in 2016. Related , , also expired in 2016 and expired in 2018.
Certicom holds and regarding digital signatures on a smartcard; these expired in 2017 and 2016 respectively.
Certicom holds
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https://en.wikipedia.org/wiki/Ceramic%20knife
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A ceramic knife is a knife with a ceramic blade typically made from zirconium dioxide (ZrO2; also known as zirconia), rather than the steel used for most knives. Ceramic knife blades are usually produced through the dry-pressing and firing of powdered zirconia using solid-state sintering. The blades typically score 8.5 on the Mohs scale of mineral hardness, compared to 4.5 for normal steel and 7.5 to 8 for hardened steel and 10 for diamond. The resultant blade has a hard edge that stays sharp for much longer than conventional steel blades. However, the blade is brittle, subject to chipping, and will break rather than flex if twisted. The ceramic blade is sharpened by grinding the edges with a diamond-dust-coated grinding wheel.
Zirconium oxide
Zirconium oxide is used due to the fact it exists in several different forms. Zirconium can be monoclinic, tetragonal or cubic in form. Cooling to the monoclinic phase after sintering causes a large volume change, which often causes stress fractures in pure zirconia. Additives such as magnesia, calcia and yttria are used in manufacturing the knife material to stabilize the high-temperature phases and minimize this volume change. The highest strength and toughness is produced by the addition of 3 mol% yttrium oxide yielding partially stabilized zirconia. This material consists of a mixture of tetragonal and cubic phases with a bending strength of nearly . Small cracks allow phase transformations to occur, which essentially close the cracks and prevent catastrophic failure, resulting in a relatively tough ceramic material, sometimes known as TTZ (transformation-toughened zirconia).
Properties
Ceramic knives are substantially harder than steel knives, will not corrode in harsh environments, are non-magnetic, and do not conduct electricity at room temperature. Because of their resistance to strong acid and caustic substances, and their ability to retain a cutting edge longer than steel knives, ceramic knives are suitable f
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https://en.wikipedia.org/wiki/Reflection%20principle
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In set theory, a branch of mathematics, a reflection principle says that it is possible to find sets that, with respect to any given property, resemble the class of all sets. There are several different forms of the reflection principle depending on exactly what is meant by "resemble". Weak forms of the reflection principle are theorems of ZF set theory due to , while stronger forms can be new and very powerful axioms for set theory.
The name "reflection principle" comes from the fact that properties of the universe of all sets are "reflected" down to a smaller set.
Motivation
A naive version of the reflection principle states that "for any property of the universe of all sets we can find a set with the same property". This leads to an immediate contradiction: the universe of all sets contains all sets, but there is no set with the property that it contains all sets. To get useful (and non-contradictory) reflection principles we need to be more careful about what we mean by "property" and what properties we allow.
Reflection principles are associated with attempts to formulate the idea that no one notion, idea, or statement can capture our whole view of the universe of sets. Kurt Gödel described it as follows:
Georg Cantor expressed similar views on Absolute Infinity: All cardinality properties are satisfied in this number, in which held by a smaller cardinal.
To find non-contradictory reflection principles we might argue informally as follows. Suppose that we have some collection A of methods for forming sets (for example, taking powersets, subsets, the axiom of replacement, and so on). We can imagine taking all sets obtained by repeatedly applying all these methods, and form these sets into a class X, which can be thought of as a model of some set theory. But in light of this view, V is not be exhaustible by a handful of operations, otherwise it would be easily describable from below, this principle is known as inexhaustibility (of V). As a result, V is large
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https://en.wikipedia.org/wiki/Caryophyllene
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Caryophyllene (), more formally (−)-β-caryophyllene, (BCP), is a natural bicyclic sesquiterpene that is a constituent of many essential oils, especially clove oil, the oil from the stems and flowers of Syzygium aromaticum (cloves), the essential oil of Cannabis sativa, copaiba, rosemary, and hops. It is usually found as a mixture with isocaryophyllene (the cis double bond isomer) and α-humulene (obsolete name: α-caryophyllene), a ring-opened isomer. Caryophyllene is notable for having a cyclobutane ring, as well as a trans-double bond in a 9-membered ring, both rarities in nature.
Caryophyllene is one of the chemical compounds that contributes to the aroma of black pepper.
Pharmacology
β-Caryophyllene acts as a full agonist of the Cannabinoid receptor type 2 (CB2 receptor) in rats. β-Caryophyllene has a binding affinity of Ki = 155nM at the CB2 receptors in mice. β-Caryophyllene has been shown to have anti-inflammatory action linked to its CB2 receptor activity in a study comparing the pain killing effects in mice with and without CB2 receptors with the group of mice without CB2 receptors seeing little benefit compared to the mice with functional CB2 receptors. β-Caryophyllene has the highest cannabinoid activity compared to the ring opened isomer α-caryophyllene Humulene which may modulate CB2 activity. To compare binding, Cannabinol (CBN) binds to the CB2 receptors as a partial agonist with an affinity of CB2 Ki = 126.4 nM while Delta-9-Tetrahydrocannabinol binds to the CB2 receptors as a partial agonist with an affinity of Ki = 36nM.
Caryophyllene helps to improve cold tolerance at low ambient temperatures. Wild giant pandas frequently roll in horse manure, which contains beta-caryophyllene/caryophyllene oxide, to inhibit transient receptor potential melastatin 8 (TRPM8), an archetypical cold-activated ion channel of mammals.
ß-caryophyllene could be efficiently used in the fight against cancer. For example, in an in vitro human colorectal adenocarcinoma s
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https://en.wikipedia.org/wiki/Management%20Data%20Input/Output
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Management Data Input/Output (MDIO), also known as Serial Management Interface (SMI) or Media Independent Interface Management (MIIM), is a serial bus defined for the Ethernet family of IEEE 802.3 standards for the Media Independent Interface, or MII. The MII connects media access control (MAC) devices with Ethernet physical layer (PHY) circuits. The MAC device controlling the MDIO is called the Station Management Entity (SME).
Relationship with MII
MII has two signal interfaces:
A Data interface to the Ethernet MAC, for sending and receiving Ethernet frame data.
A PHY management interface, MDIO, used to read and write the control and status registers of the PHY in order to configure each PHY before operation, and to monitor link status during operation.
Electrical specification
The MDIO interface is implemented by two signals:
MDIO Interface Clock (MDC): clock driven by the MAC device to the PHY.
MDIO data: bidirectional, the PHY drives it to provide register data at the end of a read operation.
The bus only supports a single MAC as the master, and can have up to 32 PHY slaves.
The MDC can be periodic, with a minimum period of 400 ns, which corresponds to a maximum frequency of 2.5 MHz. Newer chips, however, allow faster accesses. For example, the DP83640 supports a 25 MHz maximum clock rate for MDC.
The MDIO requires a specific pull-up resistor of 1.5 kΩ to 10 kΩ, taking into account the total worst-case leakage current of 32 PHYs and one MAC.
Bus timing (clause 22)
Before a register access, PHY devices generally require a preamble of 32 ones to be sent by the MAC on the MDIO line. The access consists of 16 control bits, followed by 16 data bits. The control bits consist of 2 start bits, 2 access type bits (read or write), the PHY address (5 bits), the register address (5 bits), and 2 "turnaround" bits.
During a write command, the MAC provides address and data. For a read command, the PHY takes over the MDIO line during the turnaround bit times, su
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https://en.wikipedia.org/wiki/Acutance
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In photography, acutance describes a subjective perception of sharpness that is related to the edge contrast of an image. Acutance is related to the amplitude of the derivative of brightness with respect to space. Due to the nature of the human visual system, an image with higher acutance appears sharper even though an increase in acutance does not increase real resolution.
Historically, acutance was enhanced chemically during development of a negative (high acutance developers), or by optical means in printing (unsharp masking). In digital photography, onboard camera software and image postprocessing tools such as Photoshop or GIMP offer various sharpening facilities, the most widely used of which is known as "unsharp mask" because the algorithm is derived from the eponymous analog processing method.
In the example image, two light gray lines were drawn on a gray background. As the transition is instantaneous, the line is as sharp as can be represented at this resolution. Acutance in the left line was artificially increased by adding a one-pixel-wide darker border on the outside of the line and a one-pixel-wide brighter border on the inside of the line. The actual sharpness of the image is unchanged, but the apparent sharpness is increased because of the greater acutance.
Artificially increased acutance has drawbacks. In this somewhat overdone example most viewers will also be able to see the borders separately from the line, which create two halos around the line, one dark and one shimmering bright.
Tools
Several image processing techniques, such as unsharp masking, can increase the acutance in real images.
Resampling
Low-pass filtering and resampling often cause overshoot, which increases acutance, but can also reduce absolute gradient, which reduces acutance. Filtering and resampling can also cause clipping and ringing artifacts. An example is bicubic interpolation, widely used in image processing for resizing images.
Definition
One definition of acu
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https://en.wikipedia.org/wiki/Serving%20area%20interface
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The serving area interface or service area interface (SAI) is an outdoor enclosure or metal box that allows access to telecommunications wiring.
Alternate names
Access point (AP)
Cabinet (cab)
B-box (breakout box)
Cross box
Cross-connect box
Jumper wire interface (JWI)
Outside plant interface (OPI)
Pedestal (ped)
Primary cross-connection point (PCP) (UK)
Secondary cross-connection point (SCP) (UK)
Telecom cabinet
Function
The SAI provides the termination of individual twisted pairs of a telephony local loop for onward connection back to the nearest telephone exchange (US: "central office" (CO)) or remote switch, or first to transmission equipment such as a subscriber loop carrier multiplexer and then to the exchange main distribution frame (MDF).
In the United Kingdom, the components from the PCP onwards to the customer are known as "D-side" (distribution side), and from the PCP back to the MDF as the "E-side" (exchange side). In the United States, the connection back to the MDF is known as the F2 (secondary distribution cable) and/or the F1 (main feeder cable) pairs.
SAIs are used in suburban and low-density urban areas, serving some of the same purposes that manholes do in high-density urban areas. Besides a cross connect point, they sometimes contain a DSLAM or more rarely a remote concentrator or both.
See also
Demarcation point
Enclosure (electrical)
Fiber to the telecom enclosure
Sub-loop unbundling
References
Local loop
Street furniture
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https://en.wikipedia.org/wiki/Optoelectric%20nuclear%20battery
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An optoelectric nuclear battery (also radiophotovoltaic device, radioluminescent nuclear battery or radioisotope photovoltaic generator) is a type of nuclear battery in which nuclear energy is converted into light, which is then used to generate electrical energy. This is accomplished by letting the ionizing radiation emitted by the radioactive isotopes hit a luminescent material (scintillator or phosphor), which in turn emits photons that generate electricity upon striking a photovoltaic cell.
The technology was developed by researchers of the Kurchatov Institute in Moscow.
Description
A beta emitter such as technetium-99 or strontium-90 is suspended in a gas or liquid containing luminescent gas molecules of the excimer type, constituting a "dust plasma". This permits a nearly lossless emission of beta electrons from the emitting dust particles. The electrons then excite the gases whose excimer line is selected for the conversion of the radioactivity into a surrounding photovoltaic layer such that a theoretical lightweight, low-pressure, high-efficiency battery can be realized. (In practice, existing designs are heavy and involve high pressure.) These nuclides are relatively low-cost radioactive waste from nuclear power reactors. The diameter of the dust particles is so small (a few micrometers) that the electrons from the beta decay leave the dust particles nearly without loss. The surrounding weakly ionized plasma consists of gases or gas mixtures (such as krypton, argon, and xenon) with excimer lines such that a considerable amount of the energy of the beta electrons is converted into this light. The surrounding walls contain photovoltaic layers with wide forbidden zones, such as diamond, which convert the optical energy generated from the radiation into electrical energy.
A German patent provides a description of an optoelectric nuclear battery, which would consist of an excimer of argon, xenon, or krypton (or a mixture of two or three of them) in a pressu
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https://en.wikipedia.org/wiki/Common%20squirrel%20monkey
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Common squirrel monkey is the traditional common name for several small squirrel monkey species native to the tropical areas of South America. The term common squirrel monkey had been used as the common name for Saimiri sciureus before genetic research by Jessica Lynch Alfaro and others indicated S. scuireus covered at least 3 and possibly 4 species: the Guianan squirrel monkey (S. scuireus), Humboldt's squirrel monkey (S. cassiquiarensis) and Collins' squirrel monkey (S. collinsi). The Ecuadorian squirrel monkey (S. cassiquiarensis macrodon), generally regarded as a subspecies of Humboldt's squirrel monkey, had also been sometimes proposed as a separate species that had originally been included within the term "common squirrel monkey."
Range and introductions
Common squirrel monkeys are found primarily in the Amazon Basin. Before the taxon was split, it had been considered to be found within the countries of Brazil, Colombia, Ecuador, French Guiana, Guyana, Peru, Suriname and Venezuela; a small population has been introduced to Florida and many of the Caribbean Islands. However, taxonomic research in 2009 and 2015 determined that several populations that had been considered S. scuireus were actually separate species:
Guianan squirrel monkey, S. sciureus
Collins' squirrel monkey, S. collinsi
Humboldt's squirrel monkey, S. cassiquiarensis
The Ecuadorian squirrel monkey, S. cassiquiarensis macrodon, has also sometimes been regarded as a separate species.
As a result of these populations no longer being considered S. scuireus, the range of S. scuireus is now limited to Brazil and the Guianas.
A group of free-ranging individuals was spotted and photographed in 2009 at the Tijuca Forest in Rio de Janeiro – possibly the result of an illegal release or of an escape from the pet trade; by 2010, the squirrel monkey had begun to be considered as an invasive species in the Brazilian Atlantic rainforest, and concerns were expressed about its role as a predator of e
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https://en.wikipedia.org/wiki/3-Carene
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3-Carene is a bicyclic monoterpene consisting of fused cyclohexene and cyclopropane rings. It occurs as a constituent of turpentine, with a content as high as 42% depending on the source. Carene has a sweet and pungent odor, best described as a combination of fir needles, musky earth, and damp woodlands.
A colorless liquid, it is not soluble in water, but miscible with fats and oils. It is chiral, occurring naturally both as the racemate and enantio-enriched forms.
Reactions and uses
Treatment with peracetic acid gives 3,4-caranediol. Pyrolysis over ferric oxide induces rearrangement, giving p-cymene. Carene is used in the perfume industry and as a chemical intermediate.
Because carene can be found in cannabis naturally, it can also be found in cannabis distillates. Greater concentrations of carene in a distillate give it an earthier taste and smell. 3-Carene is also present in mango, giving the fruit a characteristic pine-like flavor and aroma.
References
Flavors
Cyclohexenes
Monoterpenes
Bicyclic compounds
Cyclopropanes
Sweet-smelling chemicals
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https://en.wikipedia.org/wiki/Medical%20illustration
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A medical illustration is a form of biological illustration that helps to record and disseminate medical, anatomical, and related knowledge.
History
Medical illustrations have been made possibly since the beginning of medicine in any case for hundreds (or thousands) of years. Many illuminated manuscripts and Arabic scholarly treatises of the medieval period contained illustrations representing various anatomical systems (circulatory, nervous, urogenital), pathologies, or treatment methodologies. Many of these illustrations can look odd to modern eyes, since they reflect early reliance on classical scholarship (especially Galen) rather than direct observation, and the representation of internal structures can be fanciful. An early high-water mark was the 1543 CE publication of Andreas Vesalius's De Humani Corporis Fabrica Libri Septum, which contained more than 600 exquisite woodcut illustrations based on careful observation of human dissection.
Since the time of the Leonardo da Vinci and his depictions of the human form, there have been great advancements in the art of representing the human body. The art has evolved over time from illustration to digital imaging using the technological advancements of the digital age. Berengario da Carpi was the first known anatomist to include medical illustration within his textbooks. Gray's Anatomy, originally published in 1858, is one well-known human anatomy textbook that showcases a variety of anatomy depiction techniques.
In 1895, Konrad Roentgen, a German physicist discovered the X-Ray. Internal imaging became a reality after the invention of the X-Ray. Since then internal imaging has progressed to include ultrasonic, CT, and MRI imaging.
As a profession, medical illustration has a more recent history. In the late 1890s, Max Brödel, a talented artist from Leipzig, was brought to The Johns Hopkins School of Medicine in Baltimore to illustrate for Harvey Cushing, William Halsted, Howard Kelly, and other notable clinicians
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https://en.wikipedia.org/wiki/Bone%20resorption
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Bone resorption is resorption of bone tissue, that is, the process by which osteoclasts break down the tissue in bones and release the minerals, resulting in a transfer of calcium from bone tissue to the blood.
The osteoclasts are multi-nucleated cells that contain numerous mitochondria and lysosomes. These are the cells responsible for the resorption of bone. Osteoblasts are generally present on the outer layer of bone, just beneath the periosteum. Attachment of the osteoclast to the osteon begins the process. The osteoclast then induces an infolding of its cell membrane and secretes collagenase and other enzymes important in the resorption process. High levels of calcium, magnesium, phosphate and products of collagen will be released into the extracellular fluid as the osteoclasts tunnel into the mineralized bone. Osteoclasts are prominent in the tissue destruction found in psoriatic arthritis and rheumatological disorders.
The human body is in a constant state of bone remodeling. Bone remodeling is a process which maintains bone strength and ion homeostasis by replacing discrete parts of old bone with newly synthesized packets of proteinaceous matrix. Bone is resorbed by osteoclasts, and is deposited by osteoblasts in a process called ossification. Osteocyte activity plays a key role in this process. Conditions that result in a decrease in bone mass can either be caused by an increase in resorption or by a decrease in ossification. During childhood, bone formation exceeds resorption. As the aging process occurs, resorption exceeds formation.
Bone resorption rates are much higher in post-menopausal older women due to estrogen deficiency related with menopause. Common treatments include drugs that increase bone mineral density. Bisphosphonates, RANKL inhibitors, SERMs—selective oestrogen receptor modulators, hormone replacement therapy and calcitonin are some of the common treatments. Light weight bearing exercise tends to eliminate the negative effects of bon
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https://en.wikipedia.org/wiki/Incongruent%20melting
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Incongruent melting occurs when a solid substance does not melt uniformly, so that the chemical composition of the resulting liquid is not the same as that of the original solid. During incongruent melting a new solid of different composition forms. For example, melting of orthoclase (KAlSi3O8) produces leucite (KAlSi2O6) in addition to a melt. The melt produced is richer in silica (SiO2). The proportions of leucite and melt created can be recombined to yield the bulk composition of the starting feldspar. Another mineral that can melt incongruently is enstatite (Mg2Si2O6), which produces forsterite (Mg2SiO4) in addition to a melt richer in SiO2 when melting at low pressure. Enstatite melts congruently at higher pressures between 2.5 and 5.5 kilobars.
See also
Congruent melting
Incongruent transition
Phase diagram
References
Incongruent melting from Eric Weisstein's World of Physics
Materials science
Phase transitions
Geochemistry
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https://en.wikipedia.org/wiki/Push%20email
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Push email is an email system that provides an always-on capability, in which when new email arrives at the mail delivery agent (MDA) (commonly called mail server), it is immediately, actively transferred (pushed) by the MDA to the mail user agent (MUA), also called the email client, so that the end-user can see incoming email immediately. This is in contrast with systems that check for new incoming mail every so often, on a schedule. Email clients include smartphones and, less strictly, IMAP personal computer mail applications.
Comparison with polling email
Outgoing mail is generally pushed from the sender to the final mail delivery agent (and possibly via intermediate mail servers) using Simple Mail Transfer Protocol. If the receiver uses a polling email delivery protocol, the final step from the last mail delivery agent to the client is done using a poll. Post Office Protocol (POP3) is an example of a polling email delivery protocol. At login and later at intervals, the mail user agent (client) polls the mail delivery agent (server) to see if there is new mail, and if so downloads it to a mailbox on the user's computer. Extending the "push" to the last delivery step is what distinguishes push email from polling email systems.
The reason that polling is often used for the last stage of mail delivery is that, although the server mail delivery agent would normally be permanently connected to the network, it does not necessarily know how to locate the client mail user agent, which may only be connected occasionally and also change network address quite often. For example, a user with a laptop on a Wi-Fi connection may be assigned different addresses from the network DHCP server periodically and have no persistent network name. When new mail arrives to the mail server, it does not know what address the client is currently assigned.
The Internet Message Access Protocol (IMAP) provides support for polling and notifications. When a client receives a notification from
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https://en.wikipedia.org/wiki/Pneumatic%20artificial%20muscles
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Pneumatic artificial muscles (PAMs) are contractile or extensional devices operated by pressurized air filling a pneumatic bladder. In an approximation of human muscles, PAMs are usually grouped in pairs: one agonist and one antagonist.
PAMs were first developed (under the name of McKibben Artificial Muscles) in the 1950s for use in artificial limbs. The Bridgestone rubber company (Japan) commercialized the idea in the 1980s under the name of Rubbertuators.
The retraction strength of the PAM is limited by the sum total strength of individual fibers in the woven shell. The exertion distance is limited by the tightness of the weave; a very loose weave allows greater bulging, which further twists individual fibers in the weave.
One example of a complex configuration of air muscles is the Shadow Dexterous Hand developed by the Shadow Robot Company, which also sells a range of muscles for integration into other projects/systems.
Advantages
PAMs are very lightweight because their main element is a thin membrane. This allows them to be directly connected to the structure they power, which is an advantage when considering the replacement of a defective muscle. If a defective muscle has to be substituted, its location will always be known and its substitution becomes easier. This is an important characteristic, since the membrane is connected to rigid endpoints, which introduces tension concentrations and therefore possible membrane ruptures.
Another advantage of PAMs is their inherent compliant behavior: when a force is exerted on the PAM, it "gives in", without increasing the force in the actuation. This is an important feature when the PAM is used as an actuator in a robot that interacts with a human, or when delicate operations have to be carried out.
In PAMs the force is not only dependent on pressure but also on their state of inflation. This is one of the major advantages; the mathematical model that supports the PAMs functionality is a non-linear system, which
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https://en.wikipedia.org/wiki/Hydraulic%20cylinder
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A hydraulic cylinder (also called a linear hydraulic motor) is a mechanical actuator that is used to give a unidirectional force through a unidirectional stroke. It has many applications, notably in construction equipment (engineering vehicles), manufacturing machinery, elevators, and civil engineering.
A hydraulic cylinder is a hydraulic actuator that provides linear motion when hydraulic energy is converted into mechanical movement. It can be likened to a muscle in that, when the hydraulic system of a machine is activated, the cylinder is responsible for providing the motion.
Operation
Hydraulic cylinders get their power from pressurized hydraulic fluid, which is incompressible. Typically oil is used as hydraulic fluid. The hydraulic cylinder consists of a cylinder barrel, in which a piston connected to a piston rod moves back and forth. The barrel is closed on one end by the cylinder bottom (also called the cap) and the other end by the cylinder head (also called the gland) where the piston rod comes out of the cylinder. The piston has sliding rings and seals. The piston divides the inside of the cylinder into two chambers, the bottom chamber (cap end) and the piston rod side chamber (rod end/head-end).
Flanges, trunnions, clevises, and lugs are common cylinder mounting options. The piston rod also has mounting attachments to connect the cylinder to the object or machine component that it is pushing or pulling.
A hydraulic cylinder is the actuator or "motor" side of this system. The "generator" side of the hydraulic system is the hydraulic pump which delivers a fixed or regulated flow of oil to the hydraulic cylinder, to move the piston. There are three types of pump widely used: hydraulic hand pump, hydraulic air pump, and hydraulic electric pump. The piston pushes the oil in the other chamber back to the reservoir. If we assume that the oil enters from the cap end, during extension stroke, and the oil pressure in the rod end/head end is approximately zero,
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https://en.wikipedia.org/wiki/List%20of%20exceptional%20set%20concepts
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This is a list of exceptional set concepts. In mathematics, and in particular in mathematical analysis, it is very useful to be able to characterise subsets of a given set X as 'small', in some definite sense, or 'large' if their complement in X is small. There are numerous concepts that have been introduced to study 'small' or 'exceptional' subsets. In the case of sets of natural numbers, it is possible to define more than one concept of 'density', for example. See also list of properties of sets of reals.
Almost all
Almost always
Almost everywhere
Almost never
Almost surely
Analytic capacity
Closed unbounded set
Cofinal (mathematics)
Cofinite
Dense set
IP set
2-large
Large set (Ramsey theory)
Meagre set
Measure zero
Natural density
Negligible set
Nowhere dense set
Null set, conull set
Partition regular
Piecewise syndetic set
Schnirelmann density
Small set (combinatorics)
Stationary set
Syndetic set
Thick set
Thin set (Serre)
Exceptional
Exceptional
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https://en.wikipedia.org/wiki/Citronellol
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Citronellol, or dihydrogeraniol, is a natural acyclic monoterpenoid. Both enantiomers occur in nature. (+)-Citronellol, which is found in citronella oils, including Cymbopogon nardus (50%), is the more common isomer. (−)-Citronellol is widespread, but particularly abundant in the oils of rose (18–55%) and Pelargonium geraniums.
Preparation
Several million kilograms of citronellol are produced annually. It is mainly obtained by hydrogenation of geraniol or nerol over copper chromite catalyst. Homogeneous catalysts are used for the production of enantiomers.
Uses
Citronellol is used in perfumes and as a fragrance in cleaning products. In many applications, one of the enantiomers is preferred. It is a component of citronella oil, an insect repellant.
Citronellol is used as a raw material for the production of rose oxide. It is also a precursor to many commercial and potential fragrances such as citronellol acetate, citronellyl oxyacetaldehyde, citronellyl methyl acetal, and ethyl citronellyl oxalate.
Health and safety
The United States FDA considers citronellol as generally recognized as safe (GRAS) for food use. Citronellol is subject to restrictions on its use in perfumery, as some people may become sensitised to it, but the degree to which citronellol can cause an allergic reaction in humans is disputed.
In terms of dermal safety, citronellol has been evaluated as an insect repellent.
See also
Citronellal
Geraniol
Rhodinol
Pelargonium graveolens
Perfume intolerance (allergy)
References
Perfume ingredients
Flavors
Monoterpenes
Alkenols
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https://en.wikipedia.org/wiki/Nerol
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Nerol is a monoterpenoid alcohol found in many essential oils such as lemongrass and hops. It was originally isolated from neroli oil, hence its name. This colourless liquid is used in perfumery. Like geraniol, nerol has a sweet rose odor but it is considered to be fresher. Esters and related derivatives of nerol are referred to as neryl, e.g., neryl acetate.
Isomeric with nerol is geraniol, which is trans- or E-isomer. Nerol readily loses water to form a set of C10 compounds called dipentene. Nerol can be synthesized by pyrolysis of beta-pinene, which also affords myrcene. Hydrochlorination of myrcene gives a series of isomeric chlorides.
See also
Citral
Citronellol
Geraniol
Linalool
Perfume allergy
References
Primary alcohols
Alkene derivatives
Perfume ingredients
Flavors
Monoterpenes
Sweet-smelling chemicals
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https://en.wikipedia.org/wiki/Phosphoinositide%20phospholipase%20C
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Phosphoinositide phospholipase C (PLC, EC 3.1.4.11, triphosphoinositide phosphodiesterase, phosphoinositidase C, 1-phosphatidylinositol-4,5-bisphosphate phosphodiesterase, monophosphatidylinositol phosphodiesterase, phosphatidylinositol phospholipase C, PI-PLC, 1-phosphatidyl-D-myo-inositol-4,5-bisphosphate inositoltrisphosphohydrolase; systematic name 1-phosphatidyl-1D-myo-inositol-4,5-bisphosphate inositoltrisphosphohydrolase) is a family of eukaryotic intracellular enzymes that play an important role in signal transduction processes. These enzymes belong to a larger superfamily of Phospholipase C. Other families of phospholipase C enzymes have been identified in bacteria and trypanosomes. Phospholipases C are phosphodiesterases.
Phospholipase Cs participate in phosphatidylinositol 4,5-bisphosphate (PIP2) metabolism and lipid signaling pathways in a calcium-dependent manner. At present, the family consists of six sub-families comprising a total of 13 separate isoforms that differ in their mode of activation, expression levels, catalytic regulation, cellular localization, membrane binding avidity and tissue distribution. All are capable of catalyzing the hydrolysis of PIP2 into two important second messenger molecules, which go on to alter cell responses such as proliferation, differentiation, apoptosis, cytoskeleton remodeling, vesicular trafficking, ion channel conductance, endocrine function and neurotransmission.
Reaction and catalytic mechanism
All family members are capable of catalyzing the hydrolysis of PIP2, a phosphatidylinositol at the inner leaflet of the plasma membrane into the two second messengers, inositol trisphosphate (IP3) and diacylglycerol (DAG).
The chemical reaction may be expressed as:
1-phosphatidyl-1D-myo-inositol 4,5-bisphosphate + H2O 1D-myo-inositol 1,4,5-trisphosphate + diacylglycerol
PLCs catalyze the reaction in two sequential steps. The first reaction is a phosphotransferase step that involves an intramolecular attack betw
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https://en.wikipedia.org/wiki/Voja%20Antoni%C4%87
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Vojislav "Voja" Antonić (, ʾ, 12 July 1952) is a Serbian inventor, journalist, and writer. He is known for creating a build-it-yourself home computer Galaksija and originating a related "Build your own computer Galaksija" initiative with Dejan Ristanović. This initiative encouraged and enlightened thousands of computer enthusiasts during the 1980s in the Socialist Federal Republic of Yugoslavia. Antonić has donated many of his personal creations to the public domain. He was also a magazine editor and contributed to a number of radio shows.
Biography
While in school, Voja Antonić found a passion for HAM radios. He obtained a licence and a callsign to broadcast his own waves. One day, the state police seized all CB Band units known to operate in the country, creating a new trend for HAM radio units which bored Voja Antonić who decided to move on towards new digital technologies.
His first creation with a microprocessor was Conway's Game of Life machine which shows its state using 16x16 matrix of red LEDs. Without a computer, Voja Antonić wrote the code on paper and operated the input in the system byte by byte using rotary switches. LEDs being expensive back then, it took him months to buy and install the last LEDs. A replica of his machine reportedly worked flawlessly almost continuously for 40 years.
When personal computers arrived on the market, they were not accessible in Yugoslavia. Voja Antonić asked a friend in the USA to disassemble a TRS-80 Model I and send it to him and received it labelled as "technical junk". He received it, reassembled it, and started his new computer passion.
While studying at the Faculty of Dramatic Arts in the late 1970s, he started to build computer systems capable of rendering animations.
Prior to the Winter of 1981/1982, the Skiing Federation of Serbia timed the competitors using regular stopwatches and hand signaling. The upcoming Balkan competition required this to be improved and more precise. In 1981, Antonić created a sm
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https://en.wikipedia.org/wiki/Dejan%20Ristanovi%C4%87
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Dejan Ristanović (, Belgrade, 16 April 1963), is a well known Serbian writer and computer publicist.
In January 1981 he wrote the first article on personal computers for the popular science magazine Galaksija (Galaxy). During the following years he wrote many articles about programmable calculators and home computers.
In December 1983 he wrote a special edition of Galaksija called "Computers in Your Home" (Računari u vašoj kući), the first computer magazine in former Yugoslavia. This issue featured entire schematic diagrams guides on how to build computer Galaksija, created by Voja Antonić.
The series of special editions was eventually developed into computer magazine Računari (Computers). Ristanović was a contributor of Računari for 11 years. After that, in 1995 Ristanović founded the PC Press publishing company and magazine PC, the first privately owned computer magazine in Serbia. Ristanović has been the editor-in-chief of PC for more than 10 years.
In 1989 he co-founded Sezam BBS, which eventually become a major BBS system and evolved to Internet provider Sezam Pro, which in 2009 merged in Orion Telecom.
Dejan Ristanović is the author of about 20 books and more than 500 magazine articles about computers, written in the Serbian and English languages. He also operates the www.ti59.com nostalgia home page of TI-59 programmable calculators.
Dejan Ristanović is alumnus of Mathematical Gymnasium Belgrade, graduated in 1981 (search term in the list: "Ристановић Дејан").
References
External links
Dejan Ristanović's home page
Dejan Ristanovic's home page
List of publications
TI-59 page
Sezam Pro Internet provider
Orion Telecom
Mathematical Gymnasium Belgrade
Magazine founders
Serbian technology writers
Computer programmers
Serbian businesspeople
Serbian journalists
Galaksija (computer)
Living people
Year of birth missing (living people)
Serbian magazine editors
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https://en.wikipedia.org/wiki/Weather%20spotting
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Weather spotting is observing weather for the purpose of reporting to a larger group or organization. Examples include National Weather Service (NWS) co-op observers and Skywarn storm spotters.
Storm spotters
A storm spotter is a specific type of weather spotter. In the U.S., these volunteers are usually trained by the National Weather Service or local Skywarn group, and are given a phone number, internet outlet, or amateur radio frequency to report to if a severe weather event, such as a tornado, severe thunderstorm, or flash flood occurs where the spotter is located. They add ground truth information to remote sensing technology such as weather radar. Canwarn is the national storm spotting program of Canada, Skywarn Europe covers about a dozen countries (including the U.K., which is also covered by TORRO), and Australia also has a program organized by the Bureau of Meteorology.
National Weather Service Coop Observers
The National Weather Service Cooperative Observer Program (COOP) is a network of around 11,000 volunteers that record official weather observations across the United States. Data is taken from a multitude of geographic regions and topography, and sent to the National Weather Service and National Climatic Data Center (NCDC) for official records. In making these reports, observers use a specialized set of jargon and slang to describe their observations.
Cooperative weather observers often double as storm spotters. Some are also river and coastal watchers, typically reporting gauge readings.
Media weather spotters
Since New England experiences harsh winters, several regional television stations use weather spotters for up-to-date snowfall amounts and reports. WHDH-TV's network, launched by former meteorologist Todd Gross, is the largest in New England with close to 300 spotters. The former name of the group was "WHDHwx - The 7NEWS Weather Spotter Group." In December 2005, the group's name was switched to "NEWeather - Todd Gross' Weather Spotter N
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https://en.wikipedia.org/wiki/Saxon%20math
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Saxon math, developed by John Saxon (1923–1996), is a teaching method for incremental learning of mathematics created in the 1980s. It involves teaching a new mathematical concept every day and constantly reviewing old concepts. Early editions were deprecated for providing very few opportunities to practice the new material before plunging into a review of all previous material. Newer editions typically split the day's work evenly between practicing the new material and reviewing old material. It uses a steady review of all previous material, with a focus on students who struggle with retaining the math they previously learned. However, it has sometimes been criticized for its heavy emphasis on rote rather than conceptual learning.
The Saxon Math 1 to Algebra 1/2 (the equivalent of a Pre-Algebra book) curriculum is designed so that students complete assorted mental math problems, learn a new mathematical concept, practice problems relating to that lesson, and solve a variety of problems. Daily practice problems include relevant questions from the current day's lesson as well as cumulative problems. This daily cycle is interrupted for tests and additional topics. From Algebra 1/2 on, the higher level books remove the mental math problems and incorporate testing more frequently.
Saxon Publishers has also published a phonics and spelling curriculum. This curriculum, authored by Lorna Simmons and first published in 2005, follows the same incremental principles as the Saxon Math curriculum.
The Saxon math program has a specific set of products to support homeschoolers, including solution keys and ready-made tests, which makes it popular among some homeschool families. It has also been adopted as an alternative to reform mathematics programs in public and private schools. Saxon teaches memorization of algorithms, unlike many reform texts.
Relation to Common Core
In some reviews, such as ones performed by the nonprofit curriculum rating site EdReports.org, Saxon M
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https://en.wikipedia.org/wiki/TORQUE
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The Terascale Open-source Resource and Queue Manager (TORQUE) is a distributed resource manager providing control over batch jobs and distributed compute nodes. TORQUE can integrate with the non-commercial Maui Cluster Scheduler or the commercial Moab Workload Manager to improve overall utilization, scheduling and administration on a cluster.
The TORQUE community has extended the original Portable Batch System (PBS) to extend scalability, fault tolerance, and functionality. Contributors include NCSA, OSC, USC, the US DOE, Sandia, PNNL, UB, TeraGrid and other HPC organizations. As of June 2018, TORQUE is no longer open-source even though previously it was described by its developers as open-source software, using the OpenPBS version 2.3 license and as non-free software by the Debian Free Software Guidelines due to license issues.
Feature set
TORQUE provides enhancements over standard OpenPBS in the following areas:
Fault Tolerance
Additional failure conditions checked/handled.
Node health check script support.
Scheduling Interface
Extended query interface providing the scheduler with additional and more accurate information.
Extended control interface allowing the scheduler increased control over job behavior and attributes.
Allows the collection of statistics for completed jobs.
Scalability
Significantly improved server to worker nodes' Machine Oriented Mini-server (MOM) communication model.
Ability to handle larger clusters. (over 15 TF/2,500 processors)
Ability to handle larger jobs. (over 2000 processors)
Ability to support larger server messages.
Usability
Extensive logging additions.
More human readable logging. (i.e. no more "error 15038 on command 42")
See also
Beowulf cluster
HTCondor
Maui Cluster Scheduler
Open Source Cluster Application Resources (OSCAR)
Portable Batch System
Slurm Workload Manager
Univa Grid Engine
References
External links
TORQUE Resource Manager Documentation
OpenPBS home page
OpenPBS Open Source Projec
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https://en.wikipedia.org/wiki/Barrer
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Barrer is a non-SI unit of gas permeability (specifically, gas permeability) used in the membrane technology and contact lens industry. It is named after Richard Barrer.
Definition
Here the 'cm3STP' is standard cubic centimeter, which is a unit of amount of gas rather than a unit of volume. It represents the number of gas molecules or moles that would occupy one cubic centimeter at standard temperature and pressure, as calculated via the ideal gas law.
The cm corresponds in the permeability equations to the thickness of the material whose permeability is being evaluated, the cm3STPcm−2s−1 to the flux of gas through the material, and the cmHg to the pressure drop across the material. That is, it measures the rate of fluid flow passing through an area of material with a thickness driven by a given pressure. See Darcy's Law.
In SI unit Barrer can be expressed as:
To convert to CGS permeability unit, one must use the following:
Where M is the molecular weight of the penetrant gas (g/mol).
Another commonly expressed unit is Gas Permeance Unit (GPU). It is used in the measurement of gas permeance. Permeance can be expressed as the ratio of the permeability with the thickness of membrane.
Or in SI units:
References
Units of measurement
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https://en.wikipedia.org/wiki/Gavilan%20SC
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The Gavilan SC is a laptop computer that was the first ever to be marketed as a "laptop". The computer ran on an Intel 8088 microprocessor running at 5 MHz and sported a touchpad for a pointing device, one of the first computers to do so. The laptop was developed by Manuel "Manny" Fernandez and released by the Gavilan Computer Corporation, the company he founded and owned, in May 1983.
History
The brainchild of Gavilan Computer Corporation founder Manuel (Manny) Fernandez, the Gavilan was introduced in May 1983, at approximately the same time as the similar Sharp PC-5000. It came to market a year after the GRiD Compass, with which it shared several pioneering details, notably a clamshell design, in which the screen folds shut over the keyboard.
The Gavilan, however, was more affordable than the GRiD, at a list price of around US$4000. Unlike the GRiD, it was equipped with a floppy disk drive and used the MS-DOS operating system, although it was only partially IBM PC-compatible. Powered by a 5 MHz Intel 8088 processor, it was equipped with a basic graphical user interface, stored in its 48 KB of ROM. The operating system used a FORTH-like interpreter to generate very compact code. An internal 300-baud modem was standard. A compact printer that attached to the rear of the machine was an option.
The machine's included software was a terminal program, MS-DOS, and MBasic (a version of the BASIC programming language). An Office Pack of four applications—Sorcim SuperCalc and SuperWriter, and pfs:File and pfs:Report—was optional.
It was far smaller than competing IBM compatible portables, such as the Compaq Portable, which were the size of a portable sewing machine and weighed more than twice the Gavilan's 4 kg (9 lb), and unlike the Gavilan they could not run off batteries. Gavilan claimed the SC could run up to nine hours on its built-in nickel-cadmium batteries.
Jack Hall, an award-winning industrial designer, was chosen to work out the ergonomics, mechanics and ov
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https://en.wikipedia.org/wiki/Phu%20Phong%20Glass%20Joint%20Stock%20Company
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Phu Phong Glass Joint Stock Company (CTCP Sản xuất Thương mại Dịch vụ Phú Phong) is a company based in the outskirts of Ho Chi Minh City that makes architectural glass and float glass for use in furniture and construction materials. Phu Phong's main offices are in Ho Chi Minh City. Its stock is listed at the Hanoi Securities Trading Center, symbol is PPG.
See also
List of companies of Vietnam
References
External links
Phu Phong Glass official page
Phu Phong Glass' page at Importgenius
Phu Phong Glass' page at Alacrastore
Phu Phong Glass' page at Hanoi Securities Trading Center
Companies listed on the Hanoi Stock Exchange
Manufacturing companies based in Ho Chi Minh City
Glassmaking companies
Vietnamese brands
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https://en.wikipedia.org/wiki/Conjunctive%20grammar
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Conjunctive grammars are a class of formal grammars
studied in formal language theory.
They extend the basic type of grammars,
the context-free grammars,
with a conjunction operation.
Besides explicit conjunction,
conjunctive grammars allow implicit disjunction
represented by multiple rules for a single nonterminal symbol,
which is the only logical connective expressible in context-free grammars.
Conjunction can be used, in particular,
to specify intersection of languages.
A further extension of conjunctive grammars
known as Boolean grammars
additionally allows explicit negation.
The rules of a conjunctive grammar are of the form
where is a nonterminal and
, ...,
are strings formed of symbols in and (finite sets of terminal and nonterminal symbols respectively).
Informally, such a rule asserts that
every string over
that satisfies each of the syntactical conditions represented
by , ...,
therefore satisfies the condition defined by .
Formal definition
A conjunctive grammar is defined by the 4-tuple where
is a finite set; each element is called a nonterminal symbol or a variable. Each variable represents a different type of phrase or clause in the sentence. Variables are also sometimes called syntactic categories.
is a finite set of terminals, disjoint from , which make up the actual content of the sentence. The set of terminals is the alphabet of the language defined by the grammar .
is a finite set of productions, each of the form for some in and . The members of are called the rules or productions of the grammar.
is the start variable (or start symbol), used to represent the whole sentence (or program). It must be an element of .
It is common to list all right-hand sides for the same left-hand side on the same line, using | (the pipe symbol) to separate them. Rules and can hence be written as .
Two equivalent formal definitions
of the language specified by a conjunctive grammar exist.
One definition is based upon representing the gram
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https://en.wikipedia.org/wiki/Boolean%20grammar
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Boolean grammars, introduced by , are a class of formal grammars studied in formal language theory. They extend the basic type of grammars, the context-free grammars, with conjunction and negation operations. Besides these explicit operations, Boolean grammars allow implicit disjunction represented by multiple rules for a single nonterminal symbol, which is the only logical connective expressible in context-free grammars. Conjunction and negation can be used, in particular, to specify intersection and complement of languages. An intermediate class of grammars known as conjunctive grammars allows conjunction and disjunction, but not negation.
The rules of a Boolean grammar are of the form
where is a nonterminal, and , ..., , , ..., are strings formed of symbols in and . Informally, such a rule asserts that every string over that satisfies each of the syntactical conditions represented by , ..., and none of the syntactical conditions represented by , ..., therefore satisfies the condition defined by .
There exist several formal definitions of the language generated by a Boolean grammar. They have one thing in common: if the grammar is represented as a system of language equations with union, intersection, complementation and concatenation, the languages generated by the grammar must be the solution of this system. The semantics differ in details, some define the languages using language equations, some draw upon ideas from the field of logic programming. However, these nontrivial issues of formal definition are mostly irrelevant for practical considerations, and one can construct grammars according to the given informal semantics. The practical properties of the model are similar to those of conjunctive grammars, while the descriptional capabilities are further improved. In particular, some practically useful properties inherited from context-free grammars, such as efficient parsing algorithms, are retained, see .
References
Preprint available on
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https://en.wikipedia.org/wiki/Indian%20National%20Mathematical%20Olympiad
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The Indian National Mathematical Olympiad (INMO) is a high school mathematics competition held annually in India since 1989. It is the third tier in the Indian team selection procedure for the International Mathematical Olympiad and is conducted by the Homi Bhabha Centre for Science Education (HBCSE) under the aegis of the National Board of Higher Mathematics (NBHM).
The Mathematical Olympiad Program is a five stage process conducted under the aegis of National Board for Higher Mathematics (NBHM). The first stage PRMO is conducted by the Mathematics Teachers’ Association (India). All the remaining stages are organized by Homi Bhabha Centre for Science Education (HBCSE).
Eligibility and participant selection process
The INMO is conducted by the MO Cell which is held on the third Sunday of January at 30 centers across the country. Prospective candidates first need to write the Pre-Regional Mathematical Olympiad (known as PRMO or Pre-RMO) then the Regional Mathematical Olympiad of their respective state or region. Around thirty students are selected from each region, to write the INMO. The best-performing students from the RMO (approximately 900) qualify for the second stage INMO.
Structure of the examination
The Indian National Mathematics Olympiad is the national level Olympiad which is conducted to select students for the International Mathematical Olympiad Training Camp, which is further conducted to select the Indian team for the International Mathematical Olympiad. It is similar to the USAMO conducted in the USA. The exam structure various from year to year. From 2024 onwards, INMO will consist of 6 problems to be solved over a span of 4.5 hrs. The topics asked are generally what is taught at high school level, except calculus. The difficulty of the problems tends to be generally higher than what is done in schools, with strong focus on application of concepts. The topics generally covered are Number Theory, Geometry, Combinatorics and Algebra.
Further stag
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https://en.wikipedia.org/wiki/Distribution%20list
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A distribution list is an application of email client programs that allows a user to maintain a list of email addresses and send messages to all of them at once. This can be referred to as an electronic mailshot. Sending mail using a distribution list differs from an electronic mailing list or the email option found in an Internet forum as it is usually for one-way traffic and not for coordinating a discussion. A distribution list is an email equivalent of a postal mailing list. Can also be called "Distro".
References
Email
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https://en.wikipedia.org/wiki/Bianchi%20group
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In mathematics, a Bianchi group is a group of the form
where d is a positive square-free integer. Here, PSL denotes the projective special linear group and is the ring of integers of the imaginary quadratic field .
The groups were first studied by as a natural class of discrete subgroups of , now termed Kleinian groups.
As a subgroup of , a Bianchi group acts as orientation-preserving isometries of 3-dimensional hyperbolic space . The quotient space is a non-compact, hyperbolic 3-fold with finite volume, which is also called Bianchi orbifold. An exact formula for the volume, in terms of the Dedekind zeta function of the base field , was computed by Humbert as follows. Let be the discriminant of , and , the discontinuous action on , then
The set of cusps of is in bijection with the class group of . It is well known that every non-cocompact arithmetic Kleinian group is weakly commensurable with a Bianchi group.
References
External links
Allen Hatcher, Bianchi Orbifolds
Group theory
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https://en.wikipedia.org/wiki/Automatically%20switched%20optical%20network
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Automatically Switched Optical Network (ASON) is a concept for the evolution of transport networks which allows for dynamic policy-driven control of an optical or SDH network based on signaling between a user and components of the network. Its aim is to automate the resource and connection management within the network. The IETF defines ASON as an alternative/supplement to NMS based connection management.
The need for ASON
In an optical network without ASON, whenever a user requires more bandwidth, there is a request for a new connection from the user to the service provider. The service provider must then manually plan and configure the route in the network. This is not only time consuming, but also wastes bandwidth if the user sparingly uses the connection. Bandwidth is increasingly becoming a precious resource and expectations from future optical networks are that they should be able to efficiently handle resources as quickly as possible. ASON fulfills some of the requirements of optical networks such as:
Fast and automatic end-to-end provisioning
Fast and efficient re-routing
Support of different clients, but optimized for IP
Dynamic set up of connections
Support of optical virtual private networks (OVPNs)
Support of different levels of quality of service
(These requirements are not restricted to optical networks and can be applied to any transport network, including SDH Networks.)
Logical architecture of an ASON
The logical architecture of an ASON can be divided into three planes:
Transport plane
Control plane
Management plane
The Transport Plane contains a number of switches (optical or otherwise) responsible for transporting user data via connections. These switches are connected to each other via PI (Physical Interface).
The Control Plane is responsible for the actual resource and connection management within an ASON network. It consists of a series of OCC (Optical Connection Controllers), interconnected via NNIs (Network to Network Interfa
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https://en.wikipedia.org/wiki/Microfabrication
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Microfabrication is the process of fabricating miniature structures of micrometre scales and smaller. Historically, the earliest microfabrication processes were used for integrated circuit fabrication, also known as "semiconductor manufacturing" or "semiconductor device fabrication". In the last two decades microelectromechanical systems (MEMS), microsystems (European usage), micromachines (Japanese terminology) and their subfields, microfluidics/lab-on-a-chip, optical MEMS (also called MOEMS), RF MEMS, PowerMEMS, BioMEMS and their extension into nanoscale (for example NEMS, for nano electro mechanical systems) have re-used, adapted or extended microfabrication methods. Flat-panel displays and solar cells are also using similar techniques.
Miniaturization of various devices presents challenges in many areas of science and engineering: physics, chemistry, materials science, computer science, ultra-precision engineering, fabrication processes, and equipment design. It is also giving rise to various kinds of interdisciplinary research. The major concepts and principles of microfabrication are microlithography, doping, thin films, etching, bonding, and polishing.
Fields of use
Microfabricated devices include:
integrated circuits (“microchips”) (see semiconductor manufacturing)
microelectromechanical systems (MEMS) and microoptoelectromechanical systems (MOEMS)
microfluidic devices (ink jet print heads)
solar cells
flat panel displays (see AMLCD and thin-film transistors)
sensors (microsensors) (biosensors, nanosensors)
power MEMS, fuel cells, energy harvesters/scavengers
Origins
Microfabrication technologies originate from the microelectronics industry, and the devices are usually made on silicon wafers even though glass, plastics and many other substrate are in use. Micromachining, semiconductor processing, microelectronic fabrication, semiconductor fabrication, MEMS fabrication and integrated circuit technology are terms used instead of microfabrication,
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https://en.wikipedia.org/wiki/Farnesol
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Farnesol is a natural 15-carbon organic compound which is an acyclic sesquiterpene alcohol. Under standard conditions, it is a colorless liquid. It is hydrophobic, and thus insoluble in water, but miscible with oils.
Farnesol is produced from 5-carbon isoprene compounds in both plants and animals. Phosphate-activated derivatives of farnesol are the building blocks of possibly all acyclic sesquiterpenoids. These compounds are doubled to form 30-carbon squalene, which is the precursor for steroids in plants, animals, and fungi. Farnesol and its derivatives are important starting compounds for natural and artificial organic synthesis.
Uses
Farnesol is present in many essential oils such as citronella, neroli, cyclamen, lemon grass, tuberose, rose, musk, balsam, and tolu. It is used in perfumery to emphasize the odors of sweet, floral perfumes. It enhances perfume scent by acting as a co-solvent that regulates the volatility of the odorants. It is especially used in lilac perfumes.
Farnesol is a natural pesticide for mites and is a pheromone for several other insects.
In a 1994 report released by five top cigarette companies, farnesol was listed as one of 599 additives to cigarettes. It is a flavoring ingredient.
Natural source and synthesis
Farnesol is produced from isoprene compounds in both plants and animals. When geranyl pyrophosphate reacts with isopentenyl pyrophosphate, the result is the 15-carbon farnesyl pyrophosphate, which is an intermediate in the biosynthesis of sesquiterpenes such as farnesene. Oxidation can then provide sesquiterpenoids such as farnesol.
In industry, farnesol could be synthesized from linalool
History of the name
Farnesol is found in a flower extract with a long history of use in perfumery. The pure substance farnesol was named (c. 1900–1905) after the Farnese acacia tree (Vachellia farnesiana), since the flowers from the tree were the commercial source of the floral essence in which the chemical was identified. This particular
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https://en.wikipedia.org/wiki/ARINC%20429
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ARINC 429, the "Mark 33 Digital Information Transfer System (DITS)," is the ARINC technical standard for the predominant avionics data bus used on most higher-end commercial and transport aircraft. It defines the physical and electrical interfaces of a two-wire data bus and a data protocol to support an aircraft's avionics local area network.
Technical description
Medium and signaling
ARINC 429 is a data transfer standard for aircraft avionics. It uses a self-clocking, self-synchronizing data bus protocol (Tx and Rx are on separate ports). The physical connection wires are twisted pairs carrying balanced differential signaling. Data words are 32 bits in length and most messages consist of a single data word. Messages are transmitted at either 12.5 or 100 kbit/s to other system elements that are monitoring the bus messages. The transmitter constantly transmits either 32-bit data words or the NULL state (0 Volts). A single wire pair is limited to one transmitter and no more than 20 receivers. The protocol allows for self-clocking at the receiver end, thus eliminating the need to transmit clocking data. ARINC 429 is an alternative to MIL-STD-1553.
Bit numbering, transmission order, and bit significance
The ARINC 429 unit of transmission is a fixed-length 32-bit frame, which the standard refers to as a 'word'. The bits within an ARINC 429 word are serially identified from Bit Number 1 to Bit Number 32 or simply Bit 1 to Bit 32. The fields and data structures of the ARINC 429 word are defined in terms of this numbering.
While it is common to illustrate serial protocol frames progressing in time from right to left, a reversed ordering is commonly practiced within the ARINC standard. Even though ARINC 429 word transmission begins with Bit 1 and ends with Bit 32, it is common to diagram and describe ARINC 429 words in the order from Bit 32 to Bit 1.
In simplest terms, while the transmission order of bits (from the first transmitted bit to the last transmitted bit
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https://en.wikipedia.org/wiki/Post-transcriptional%20modification
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Transcriptional modification or co-transcriptional modification is a set of biological processes common to most eukaryotic cells by which an RNA primary transcript is chemically altered following transcription from a gene to produce a mature, functional RNA molecule that can then leave the nucleus and perform any of a variety of different functions in the cell. There are many types of post-transcriptional modifications achieved through a diverse class of molecular mechanisms.
One example is the conversion of precursor messenger RNA transcripts into mature messenger RNA that is subsequently capable of being translated into protein. This process includes three major steps that significantly modify the chemical structure of the RNA molecule: the addition of a 5' cap, the addition of a 3' polyadenylated tail, and RNA splicing. Such processing is vital for the correct translation of eukaryotic genomes because the initial precursor mRNA produced by transcription often contains both exons (coding sequences) and introns (non-coding sequences); splicing removes the introns and links the exons directly, while the cap and tail facilitate the transport of the mRNA to a ribosome and protect it from molecular degradation.
Post-transcriptional modifications may also occur during the processing of other transcripts which ultimately become transfer RNA, ribosomal RNA, or any of the other types of RNA used by the cell.
mRNA processing
5' processing
Capping
Capping of the pre-mRNA involves the addition of 7-methylguanosine (m7G) to the 5' end. To achieve this, the terminal 5' phosphate requires removal, which is done with the aid of enzyme RNA triphosphatase. The enzyme guanosyl transferase then catalyses the reaction, which produces the diphosphate 5' end. The diphosphate 5' end then attacks the alpha phosphorus atom of a GTP molecule in order to add the guanine residue in a 5'5' triphosphate link. The enzyme (guanine-N7-)-methyltransferase ("cap MTase") transfers a methyl gr
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https://en.wikipedia.org/wiki/Ultramicrotomy
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Ultramicrotomy is a method for cutting specimens into extremely thin slices, called ultra-thin sections, that can be studied and documented at different magnifications in a transmission electron microscope (TEM). It is used mostly for biological specimens, but sections of plastics and soft metals can also be prepared. Sections must be very thin because the 50 to 125 kV electrons of the standard electron microscope cannot pass through biological material much thicker than 150 nm. For best resolutions, sections should be from 30 to 60 nm. This is roughly the equivalent to splitting a 0.1 mm-thick human hair into 2,000 slices along its diameter, or cutting a single red blood cell into 100 slices.
Ultramicrotomy process
Ultra-thin sections of specimens are cut using a specialized instrument called an "ultramicrotome". The ultramicrotome is fitted with either a diamond knife, for most biological ultra-thin sectioning, or a glass knife, often used for initial cuts. There are numerous other pieces of equipment involved in the ultramicrotomy process. Before selecting an area of the specimen block to be ultra-thin sectioned, the technician examines semithin or "thick" sections range from 0.5 to 2 μm. These thick sections are also known as survey sections and are viewed under a light microscope to determine whether the right area of the specimen is in a position for thin sectioning. "Ultra-thin" sections from 50 to 100 nm thick are able to be viewed in the TEM.
Tissue sections obtained by ultramicrotomy are compressed by the cutting force of the knife. In addition, interference microscopy of the cut surface of the blocks reveals that the sections are often not flat. With Epon or Vestopal as embedding medium the ridges and valleys usually do not exceed 0.5 μm in height, i.e., 5–10 times the thickness of ordinary sections (1).
A small sample is taken from the specimen to be investigated. Specimens may be from biological matter, like animal or plant tissue, or from inorgani
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https://en.wikipedia.org/wiki/John%20Robert%20Anderson%20%28psychologist%29
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John Robert Anderson (born August 27, 1947) is a Canadian-born American psychologist. He is currently professor of Psychology and Computer Science at Carnegie Mellon University.
Biography
Anderson obtained a B.A. from the University of British Columbia in 1968, and a Ph.D. in Psychology from Stanford in 1972. He became an assistant professor at Yale in 1972. He moved to the University of Michigan in 1973 as a Junior Fellow (and married Lynne Reder who was a graduate student there) and returned to Yale in 1976 with tenure. He was promoted to full professor at Yale in 1977 but moved to Carnegie Mellon University in 1978. From 1988 to 1989, he served as president of the Cognitive Science Society. He was elected to the American Academy of Arts and Sciences and the National Academy of Sciences and has received a series of awards:
1968: Governor General's Gold Medal: Graduated as top student in Arts and Sciences at University of British Columbia
1978: Early Career Award of the American Psychological Association
1989–1994: Research Scientist Award, NIMH
1994: American Psychological Association's Distinguished Scientific Career Award
1999: Elected to the National Academy of Sciences
1999: Fellow of American Academy of Arts and Sciences
2004: The David E. Rumelhart Prize, for Contributions to the Formal Analysis of Human Cognition
2005: Howard Crosby Warren Medal for outstanding achievement in Experimental Psychology in the United States and Canada, Society of Experimental Psychology
2006: Inaugural Dr. A.H. Heineken Prize for Cognitive Science awarded by the Royal Netherlands Academy of Arts and Sciences
2011: Benjamin Franklin Medal in Computer and Cognitive Science, Franklin Institute "for the development of the first large-scale computational theory of the process by which humans perceive, learn and reason, and its application to computer tutoring systems."
2016: Atkinson Prize from the National Academy of Sciences.
Research
In cognitive psychology, Joh
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https://en.wikipedia.org/wiki/Lumicera
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Lumicera is a transparent ceramic developed by Murata Manufacturing Co., Ltd.
Murata Manufacturing first developed transparent polycrystalline ceramics in February 2001. This polycrystalline ceramic is a type of dielectric resonator material commonly used in microwaves and millimeter waves. While offering superior electrical properties, high levels of transmissivity, and refractive index, it also has good optical characteristics without birefringence.
Normally, ceramics are opaque because pores are formed at triple points where grains intersect, causing scattering of incident light. Murata has optimized the entire development process of making dense and homogenous ceramics to improve their performance.
Under recommendations from Casio, the material itself has been refined for use in digital camera optical lenses by endowing it with improved transmission of short wavelength light and by reducing pores inside ceramics that reduce transparency.
Lumicera has the same light transmitting qualities as optical glass commonly used in today's conventional camera lenses, however it has a refractive index (nd = 2.08 at 587 nm) much greater than that of optical glass (nd = 1.5 – 1.85 ) and offers superior strength. The Lumicera Z variant is described as barium oxide based material, not containing any environmentally hazardous materials (e.g. lead).
Lumicera is transparent up to 10 micrometers, making it useful for instruments operating in the mid-infrared spectrum.
Lumicera is a trademark of Murata Manufacturing Co., Ltd.
Lumicera is used in some Casio Exilim cameras, where it allowed 20% reduction of the lens profile.
References
Optical materials
Ceramic materials
Ceramic engineering
Transparent materials
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https://en.wikipedia.org/wiki/Offset%20%28computer%20science%29
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In computer science, an offset within an array or other data structure object is an integer indicating the distance (displacement) between the beginning of the object and a given element or point, presumably within the same object. The concept of a distance is valid only if all elements of the object are of the same size (typically given in bytes or words).
For example, if A is an array of characters containing "abcdef", the fourth element containing the character 'd' has an offset of three from the start of A.
In assembly language
In computer engineering and low-level programming (such as assembly language), an offset usually denotes the number of address locations added to a base address in order to get to a specific absolute address. In this (original) meaning of offset, only the basic address unit, usually the 8-bit byte, is used to specify the offset's size. In this context an offset is sometimes called a relative address.
In IBM System/360 instructions, a 12-bit offset embedded within certain instructions provided a range of between 0 and 4096 bytes. For example, within an unconditional branch instruction (X'47F0Fxxx'), the xxx 12bit hexadecimal offset provided the byte offset from the base register (15) to branch to. An odd offset would cause a program check (unless the base register itself also contained an odd address)—since instructions had to be aligned on half-word boundaries to execute without a program or hardware interrupt.
The previous example describes an indirect way to address to a memory location in the format of segment:offset. For example, assume we want to refer to memory location 0xF867. One way this can be accomplished is by first defining a segment with beginning address 0xF000, and then defining an offset of 0x0867. Further, we are also allowed to shift the hexadecimal segment to reach the final absolute memory address. One thing to note here is that we can reach our final absolute address in many ways.
An offset is not always rela
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https://en.wikipedia.org/wiki/SINIX
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SINIX is a discontinued variant of the Unix operating system from Siemens Nixdorf Informationssysteme. SINIX supersedes SIRM OS and Pyramid Technology's DC/OSx. Following X/Open's acceptance that its requirements for the use of the UNIX trademark were met, version 5.44 and subsequent releases were published as Reliant UNIX by Fujitsu Siemens Computers.
Features
In some versions of SINIX (5.2x) the user could emulate the behaviour of a number of different versions of Unix (known as universes). These included System V.3, System III or BSD. Each universe had its own command set, libraries and header files.
Xenix-based SINIX
The original SINIX was a modified version of Xenix and ran on Intel 80186 processors. For some years Siemens used the NSC-32x32 (up to Sinix 5.2x) and Intel 80486 CPUs (Sinix 5.4x - non MIPS) in their MX-Series.
System V-based SINIX
Later versions of SINIX based on System V were designed for the:
SNI RM-200, RM-300, RM-400 and RM-600 servers running on the MIPS processor (SINIX-N, SINIX-O, SINIX-P, SINIX-Y)
SNI PC-MX2, MX300-05/-10/-15/-30, Siemens MX500-75/-85 running NS320xx (SINIX-H)
PC-MXi, MX300-45 on the Intel X86 processor (SINIX-L)
SNI WX-200 and other IBM-compatible i386 PCs on the Intel 80386 and newer processors (SINIX-Z)
The last release under the SINIX name was version 5.43 in 1995.
Reliant UNIX
The last Reliant UNIX versions were registered as UNIX 95 compliant (XPG4 hard branding).
The last release of Reliant UNIX was version 5.45.
See also
BS2000
VM2000
External links
Siemens Business Services - SINIX patches and support
The SINIX operating system
Sven Mascheck, SINIX V5.20 Universes
MIPS operating systems
UNIX System V
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https://en.wikipedia.org/wiki/Option%20symbol
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In finance, an option symbol is a code by which options are identified on an options exchange or a futures exchange.
History
Before 2010, the ticker (trading) symbols for US options typically looked like this: IBMAF.
This consisted of a root symbol ('IBM') + month code ('A') + strike price code ('F'). The root symbol is the symbol of the stock on the stock exchange. After this comes the month code, A-L mean January–December calls, M-X mean January–December puts. The strike price code is a letter corresponding with a certain strike price (which letter corresponds with which strike price depends on the stock).
On February 12, 2010, the five-character ticker format stopped being used in the US and Canada.
The new standard is now fully in place, as in the first few months after February 12 the LEAP roots and additional roots needed to handle large numbers of options for a given issuer were consolidated into a single root ticker for a given underlying symbol. Options Clearing Corporation's (OCC) Options Symbology Initiative (OSI) mandated an industry-wide change to a new option symbol structure, resulting in option symbols 21 characters in length. March 2010 - May 2010 was the symbol consolidation period in which all outgoing option roots will be replaced with the underlying stock symbol.
On March 18, 2013, CBOE Mini Options became available for trading on a select group of securities (AMZN, AAPL, GOOG, GLD, and SPY). These options represent a deliverable of 10 shares of an underlying security, whereas standard equity options represent a deliverable of 100 shares. CBOE appended a "7" to the end of the security symbol to represent the mini option contracts.
The OCC Option Symbol
The OCC option symbol consists of four parts:
Root symbol of the underlying stock or ETF, padded with spaces to 6 characters
Expiration date, 6 digits in the format yymmdd
Option type, either P or C, for put or call
Strike price, as the price x 1000, front padded with 0s to 8 digits
Ex
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https://en.wikipedia.org/wiki/Game%20testing
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Game testing, also called quality assurance (QA) testing within the video game industry, is a subset of game development that involves a software testing process for quality control of video games. The primary function of game testing is the discovery and documentation of software defects. Interactive entertainment software testing is a highly technical field requiring computing expertise, analytic competence, critical evaluation skills, and endurance. In recent years the field of game testing has come under fire for being extremely strenuous and unrewarding, both financially and emotionally.
History
In the early days of computer and video games, the developer was in charge of all the testing. No more than one or two testers were required due to the limited scope of the games. In some cases, the programmers could handle all the testing.
As games become more complex, a larger pool of QA resources, called "Quality Assessment" or "Quality Assurance" is necessary. Most publishers employ a large QA staff for testing various games from different developers. Despite the large QA infrastructure most publishers have, many developers retain a small group of testers to provide on-the-spot QA.
Now most game developers rely on their highly technical and game savvy testers to find glitches and 'bugs' in either the programming code or graphic layers. Game testers usually have a background playing a variety of different games on a multitude of platforms. They must be able to notate and reference any problems they find in detailed reports, meet deadlines with assignments and have the skill level to complete the game titles on their most difficult settings. Most of the time the position of game tester is a highly stressful and competitive position with little pay yet is highly sought after for it serves as a doorway into the industry. Game testers are observant individuals and can spot minor defects in the game build.
A common misconception is that all game testers enjoy alpha
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https://en.wikipedia.org/wiki/Wpa%20supplicant
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wpa_supplicant is a free software implementation of an IEEE 802.11i supplicant for Linux, FreeBSD, NetBSD, QNX, AROS, Microsoft Windows, Solaris, OS/2 (including ArcaOS and eComStation) and Haiku. In addition to being a WPA3 and WPA2 supplicant, it also implements WPA and older wireless LAN security protocols.
Features
Features include:
WPA-PSK and WPA2-PSK ("WPA-Personal", pre-shared key)
WPA3
WPA with EAP ("WPA-Enterprise", for example with RADIUS authentication server)
RSN: PMKSA caching, pre-authentication
IEEE 802.11r
IEEE 802.11w
Wi-Fi Protected Setup (WPS)
Included with the supplicant are a GUI and a command-line utility for interacting with the running supplicant. From either of these interfaces it is possible to review a list of currently visible networks, select one of them, provide any additional security information needed to authenticate with the network (for example, a passphrase, or username and password) and add it to the preference list to enable automatic reconnection in the future.
The graphical user interface is built on top of the Qt library.
wpa_supplicant can authenticate with any of the following EAP (Extensible Authentication Protocol) methods: EAP-TLS, EAP-PEAP (both PEAPv0 and PEAPv1), EAP-TTLS, EAP-SIM, EAP-AKA, EAP-AKA', EAP-pwd, EAP-EKE, EAP-PSK (experimental), EAP-FAST, EAP-PAX, EAP-SAKE, EAP-GPSK, EAP-IKEv2, EAP-MD5, EAP-MSCHAPv2, and LEAP (requires special functions in the driver).
Vulnerability to KRACK
wpa_supplicant was especially susceptible to KRACK, as it can be manipulated to install an all-zeros encryption key, effectively nullifying WPA2 protection in a man-in-the-middle attack. Version 2.7 fixed KRACK and several other vulnerabilities.
See also
NetworkManager
Supplicant
Wireless supplicant
Xsupplicant
References
External links
wpa_supplicant examples
Wi-Fi
Software that uses Qt
Articles with underscores in the title
Software using the BSD license
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https://en.wikipedia.org/wiki/Stieltjes%20moment%20problem
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In mathematics, the Stieltjes moment problem, named after Thomas Joannes Stieltjes, seeks necessary and sufficient conditions for a sequence (m0, m1, m2, ...) to be of the form
for some measure μ. If such a function μ exists, one asks whether it is unique.
The essential difference between this and other well-known moment problems is that this is on a half-line [0, ∞), whereas in the Hausdorff moment problem one considers a bounded interval [0, 1], and in the Hamburger moment problem one considers the whole line (−∞, ∞).
Existence
Let
and
Then { mn : n = 1, 2, 3, ... } is a moment sequence of some measure on with infinite support if and only if for all n, both
{ mn : n = 1, 2, 3, ... } is a moment sequence of some measure on with finite support of size m if and only if for all , both
and for all larger
Uniqueness
There are several sufficient conditions for uniqueness, for example, Carleman's condition, which states that the solution is unique if
References
Probability problems
Mathematical analysis
Moment (mathematics)
Mathematical problems
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https://en.wikipedia.org/wiki/Comb%20generator
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A comb generator is a signal generator that produces multiple harmonics of its input signal. The appearance of the output at the spectrum analyzer screen, resembling teeth of a comb, gave the device its name.
Comb generators find wide range of uses in microwave technology. E.g., synchronous signals in wide frequency bandwidth can be produced by a comb generator. The most common use is in broadband frequency synthesizers, where the high frequency signals act as stable references correlated to the lower energy references; the outputs can be used directly, or to synchronize phase-locked loop oscillators. It may be also used to generate a complete set of substitution channels for testing, each of which carries the same baseband audio and video signal.
Comb generators are also used in RFI testing of consumer electronics, where their output is used as a simulated RF emissions, as it is a stable broadband noise source with repeatable output. It is also used during compliance testing to various government requirements for products such as medical devices (FDA), military electronics (MIL-STD-461), commercial avionics (Federal Aviation Administration), digital electronics (Federal Communications Commission), in the USA.
An optical comb generator can be used as generators of terahertz radiation. Internally, it is a resonant electro-optic modulator, with the capability of generating hundreds of sidebands with total span of at least 3 terahertz (limited by the optical dispersion of the lithium niobate crystal) and frequency spacing of 17 GHz. Other construction can be based on erbium-doped fiber laser or Ti-sapphire laser often in combination with carrier envelope offset control.
See also
Comb filter
Frequency comb
References
External links
Yet another comb generator
Com-Power Corporation
Laboratory equipment
Electronic test equipment
Signal processing
Terahertz technology
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https://en.wikipedia.org/wiki/Windows%203.x
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Windows 3.x means either of, or all of the following versions of Microsoft Windows:
Windows 3.0
Windows 3.1x
Windows NT
Windows NT 3.x
3.x
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https://en.wikipedia.org/wiki/Camphene
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Camphene is a bicyclic organic compound. It is one of the most pervasive monoterpenes. As for other terpenes, it is insoluble in water, flammable, colorless, and has a pungent smell. It is a minor constituent of many essential oils such as turpentine, cypress oil, camphor oil, citronella oil, neroli, ginger oil, valerian, and mango. It is produced industrially by isomerization of the more common alpha-pinene using a solid acid catalyst such as titanium dioxide.
Camphene is used in the preparation of fragrances and as a food additive for flavoring. These include isobornyl acetate.
Biosynthesis
Camphene is biosynthesized from linalyl pyrophosphate via a sequence of carbocationic intermediates.
References
Vinylidene compounds
Perfume ingredients
Flavors
Monoterpenes
Bicyclic compounds
Cyclopentanes
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https://en.wikipedia.org/wiki/Forced%20convection
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Forced convection is a mechanism, or type of transport, in which fluid motion is generated by an external source (like a pump, fan, suction device, etc.). Alongside natural convection, thermal radiation, and thermal conduction it is one of the methods of heat transfer and allows significant amounts of heat energy to be transported very efficiently.
Applications
This mechanism is found very commonly in everyday life, including central heating, air conditioning, steam turbines, and in many other machines. Forced convection is often encountered by engineers designing or analyzing heat exchangers, pipe flow, and flow over a plate at a different temperature than the stream (the case of a shuttle wing during re-entry, for example).
Mixed convection
In any forced convection situation, some amount of natural convection is always present whenever there are gravitational forces present (i.e., unless the system is in an inertial frame or free-fall). When the natural convection is not negligible, such flows are typically referred to as mixed convection.
Mathematical analysis
When analyzing potentially mixed convection, a parameter called the Archimedes number (Ar) parametrizes the relative strength of free and forced convection. The Archimedes number is the ratio of Grashof number and the square of Reynolds number, which represents the ratio of buoyancy force and inertia force, and which stands in for the contribution of natural convection. When Ar ≫ 1, natural convection dominates and when Ar ≪ 1, forced convection dominates.
When natural convection isn't a significant factor, mathematical analysis with forced convection theories typically yields accurate results. The parameter of importance in forced convection is the Péclet number, which is the ratio of advection (movement by currents) and diffusion (movement from high to low concentrations) of heat.
When the Peclet number is much greater than unity (1), advection dominates diffusion. Similarly, much smaller ratios i
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https://en.wikipedia.org/wiki/Analytical%20ultracentrifugation
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Analytical ultracentrifugation is an analytical technique which combines an ultracentrifuge with optical monitoring systems.
In an analytical ultracentrifuge (commonly abbreviated as AUC), a sample’s sedimentation profile is monitored in real time by an optical detection system. The sample is detected via ultraviolet light absorption and/or interference optical refractive index sensitive system, monitored by light-sensitive diode array or by film in the older machines. The operator can thus observe the change of sample concentration versus the axis of the rotation profile with time as a result of the applied centrifugal field. With modern instrumentation, these observations are electronically digitized and stored for further mathematical analysis.
The information that can be obtained from an analytical ultracentrifuge includes the gross shape of macromolecules, conformational changes in macromolecules, and size distributions of macromolecules. With AUC it is possible to gain information on the number and subunit stoichiometry of non-covalent complexes and equilibrium constants of macromolecules such as proteins, DNA, nanoparticles or other assemblies from different molecule classes. The simplest measurement to be obtained is the sedimentation coefficient, which depends upon the size of the molecules being sedimented. This is the ratio of a particle's sedimentation velocity to the applied acceleration causing the sedimentation.
Analytical ultracentrifugation has recently seen a rise in use because of increased ease of analysis with modern computers and the development of software, including a National Institutes of Health supported software package, SedFit.
History
Instrumentation
An analytical ultracentrifuge has a light source and optical detectors. To allow the light to pass through the analyte during the ultracentrifuge run, specialized cells are required which have to meet high optical standards as well as to resist the centrifugal forces. Each cell consi
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https://en.wikipedia.org/wiki/Transmission%20%28BitTorrent%20client%29
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Transmission is a BitTorrent client which features a variety of user interfaces on top of a cross-platform back-end. Transmission is free software licensed under the terms of the GNU General Public License, with parts under the MIT License.
Features
Transmission allows users to quickly download files from multiple peers on the Internet and to upload their own files. By adding torrent files via the user interface, users can create a queue of files to be downloaded and uploaded. Within the file selection menus, users can customise their downloads at the level of individual files. Transmission also seeds, that is, it will automatically share downloaded content.
Transmission allows the assigning of priorities to torrents and to files within torrents, thus potentially influencing which files download first. It supports the Magnet URI scheme and encrypted connections. It allows torrent-file creation and peer exchange compatible with Vuze and μTorrent. It includes a built-in web server so that users can control Transmission remotely via the web. It also supports automatic port-mapping using UPnP/NAT-PMP, peer caching, blocklists for bad peers, bandwidth limits dependent on time-of-day, globally or per-torrent, and has partial support for IPv6. It allows the use of multiple trackers simultaneously, Local Peer Discovery, Micro Transport Protocol (μTP), and UDP tracker.
It does not support directly subscribing to RSS feeds containing torrent files for automatic download, but third-party add-ons can supply this functionality.
macOS-specific features include Dock and Growl notifications, automatic updates using Sparkle and Universal Binary (up until version 2.22).
Transmission 4.0.0, released in February 2023, added support for version 2 of the BitTorrent protocol while maintaining backward compatibility with the older v1 torrents.
Development
Transmission 1.60 and later removed support for Mac OS X v10.4. Currently, Transmission 1.54 is the last version that runs on Ma
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https://en.wikipedia.org/wiki/Hearing%20range
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Hearing range describes the range of frequencies that can be heard by humans or other animals, though it can also refer to the range of levels. The human range is commonly given as 20 to 20,000 Hz, although there is considerable variation between individuals, especially at high frequencies, and a gradual loss of sensitivity to higher frequencies with age is considered normal. Sensitivity also varies with frequency, as shown by equal-loudness contours. Routine investigation for hearing loss usually involves an audiogram which shows threshold levels relative to a normal.
Several animal species are able to hear frequencies well beyond the human hearing range. Some dolphins and bats, for example, can hear frequencies over 100 kHz. Elephants can hear sounds at 14–16 Hz, while some whales can hear infrasonic sounds as low as 7 Hz.
Measurement
A basic measure of hearing is afforded by an audiogram, a graph of the absolute threshold of hearing (minimum discernible sound level) at various frequencies throughout an organism's nominal hearing range.
Behavioural hearing tests or physiological tests can be used to find hearing thresholds of humans and other animals. For humans, the test involves tones being presented at specific frequencies (pitch) and intensities (loudness). When the subject hears the sound, they indicate this by raising a hand or pressing a button. The lowest intensity they can hear is recorded. The test varies for children; their response to the sound can be indicated by a turn of the head or using a toy. The child learns what to do upon hearing the sound, such as placing a toy man in a boat. A similar technique can be used when testing animals, where food is used as a reward for responding to the sound. The information on different mammals hearing was obtained primarily by behavioural hearing tests.
Physiological tests do not need the patient to consciously respond.
Humans
In humans, sound waves funnel into the ear via the external ear canal and reach
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https://en.wikipedia.org/wiki/8250%20UART
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The 8250 UART (universal asynchronous receiver-transmitter) is an integrated circuit designed for implementing the interface for serial communications. The part was originally manufactured by the National Semiconductor Corporation. It was commonly used in PCs and related equipment such as printers or modems. The 8250 included an on-chip programmable bit rate generator, allowing use for both common and special-purpose bit rates which could be accurately derived from an arbitrary crystal oscillator reference frequency.
The chip designations carry suffix letters for later versions of the same chip series. For example, the original 8250 was soon followed by the 8250A and 8250B versions that corrected some bugs. In particular, the original 8250 could repeat transmission of a character if the CTS line was asserted asynchronously during the first transmission attempt.
Due to the high demand, other manufacturers soon began offering compatible chips. Western Digital offered WD8250 chip under Async Communications Interface Adapter (ACIA) and Async Communications Element (ACE) names.
The 16450(A) UART, commonly used in IBM PC/AT-series computers, improved on the 8250 by permitting higher serial line speeds.
With the introduction of multitasking operating systems on PC hardware, such as OS/2, Windows NT or various flavours of UNIX, the short time available to serve character-by-character interrupt requests became a problem, therefore the IBM PS/2 serial ports introduced the 16550(A) UARTs that had a built-in 16 byte FIFO or buffer memory to collect incoming characters.
Later models added larger memories, supported higher speeds, combined multiple ports on one chip and finally became part of the now-common Super I/O circuits combining most input/output logic on a PC motherboard.
Blocks
The line interface consists of:
SOUT, SIN, /RTS, /DTR, DSR, /DCD, /CTS, /RI
Clock interface:
XIN, XOUT, /BAUDOUT, RCLK
Computer interface:
D0..D7, /RD, /WR, INTRPT, MR, A0, A1, A2
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https://en.wikipedia.org/wiki/Blog%20fiction
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Blog fiction is an online literary genre that tells a fictional story in the style of a weblog or blog. In the early years of weblogs, blog fictions were described as an exciting new genres creating new opportunities for emerging authors, but were also described as "notorious" in part because they often uneasily tread the line between fiction and hoax. Sometimes blog fictions are republished as print books, and in other cases conventional novels are written in the style of a blog without having been published as an online blog. Blog fiction is a genre of Electronic literature.
History
One of the first online stories to include blog-like elements is the online drama Online Caroline (2000). By 2004 blogging had become very popular, and blog fictions were the subject of several news articles that list a range of examples of the genre. Angela Thomas wrote a book chapter on blog fictions in 2006. A chapter of the book Blogging discusses fictional blogs in a chapter on blogs as narratives. In 2017, Emma Segar argued that "social and transmedia storytelling owe much to the narrative conventions established by the practice of blogging, but blog fiction itself has been a much overlooked form of digital literature".
Segar argues that a main feature of blog fiction is relationity between readers and fiction.
Blog fictions have been a particularly popular genre of electronic literature in Africa. The literary orality of blogs has also been analysed as a feature of African American blogs.
Fiction, truth or hoax
Blog fictions are often presented as though they are true, much as early novels were often presented as a "real" diary or letters that had been found by the author. The uncertainty can be part of their attraction to readers. For example, the first blog described in a 2004 article in The Guardian about fiction blogs is Belle de Jour, a blog that turned out not to be fiction but a real diary by Brooke Magnanti. The blog was adapted into a print book, The Intimate Adve
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https://en.wikipedia.org/wiki/405-line%20television%20system
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The 405-line monochrome analogue television broadcasting system was the first fully electronic television system to be used in regular broadcasting. The number of television lines influences the image resolution, or quality of the picture.
It was introduced with the BBC Television Service in 1936, suspended for the duration of World War II, and remained in operation in the UK until 1985. It was also used between 1961 and 1982 in Ireland, as well as from 1957 to 1973 for the Rediffusion Television cable service in Hong Kong. 405-line was approved as System A in the CCIR assignment of broadcast systems.
Sometimes called the Marconi-EMI system, it was developed in 1934 by the EMI Research Team led by Isaac Shoenberg. The figure of 405 lines had been chosen following discussions over Sunday lunch at the home of Alan Blumlein. The system used interlacing; EMI had been experimenting with a 243-line all-electronic interlaced system since 1933. In the 405 system the scanning lines were broadcast in two complementary fields, 50 times per second, creating 25 frames per second. The actual image was 376 lines high and interlaced, with additional unused lines making the frame up to 405 lines to give the slow circuitry time to prepare for the next frame; in modern terms it would be described as "376i".
At the time of its introduction the 405-line system was referred to as "high definition" – which it was, compared to earlier systems, although of lower definition than 625-line and later standards.
On the United States the FCC had briefly approved a 405-line color television standard in October 1950, which was developed by CBS. The CBS system was incompatible with existing black-and-white receivers. It used a rotating color wheel, reduced the number of scan lines from 525 to 405, and increased the field rate from 60 to 144, but had an effective frame rate of only 24 frames per second.
History
United Kingdom
Development
In 1934, the British government set up a committee (th
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https://en.wikipedia.org/wiki/List%20of%20forests%20in%20France
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Metropolitan France contains a total of of tree coverage, with considered to be forestry by the National Forest Inventory (IFN). Of those , consist of leafy forests while the remaining consist of evergreen forests.
The majority of forestry in French overseas departments is found in French Guiana, which contains of forests.
of forests in France are publicly owned, with the remaining being privately owned. Two-thirds of privately owned forests are larger than , and 48% are larger than .
The largest forests in France by region are as follows:
Alsace
Forêt de la Hardt (or de la Harth) (130 km²)
Forêt du Donon
Forêt de Haguenau (137 km²)
Forêt d'Obernai
Forêt de Sélesta-Illwald (15 km²)
Aquitaine
Forêt d'Iraty (173 km²)
Forêt des Landes (10,000 km²)
Forêt de Lège et Garonne
Auvergne
Forêt de Gros-Bois
Forêt de Marigny
Forêt de Messarges
Forêt des Prieurés Maladier
Forêt de Tronçais (106 km²)
Brittany
Forêt de Brocéliande
Forêt de Carnoët
Forêt de Coëtquen
Forêt du Cranou
Forêt de Fougères (16 km²)
Forêt de Fréau
Forêt de Huelgoat (6 km²)
Forêt de Hunaudaye
Forêt de La Guerche
Forêt de Liffré
Forêt de Mesnil
Forêt de Paimpont (80 km²)
Forêt de Rennes in Liffré
Forêt de Saint-Aubin-du-Cormier
Forêt de Lanouée (32 km², private)
Burgundy
Forêt d'Arcy
Forêt de la Bertrange (76 km²)
Forêt de Borne
Forêt de Champornot
Forêt de Châtillon (88 km²)
Forêt Chenue
Forêt domaniale de Cîteaux (35 km²)
Forêt des Courgeonneries, Forêt des Dames
Forêt de Donzy
Forêt de Flavigny
Forêt de Fontenay
Forêt des Minimes
Forêt de Saulieu
Forêt de Vauluisant, also known as the Forêt de Lancy
Centre
Forêt d'Amboise
Forêt de Bercé (55 km²)
Forêt de Blois
Forêt de Boulogne (40 km²)
Forêt de Bruadan
Parc de Chambord
Forêt de Chaumont
Forêt de Cheverny
Forêt de Chinon
Forêt du Choussy
Forêt de Gâtine
Forêt d'Ivoy
Forêt de Loches
Forêt de Moléans
Forêt de Montargis
Forêt de Montrichard
Forêt d'Orléans (340 km²)
Forêt de P
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https://en.wikipedia.org/wiki/Polarizing%20filter%20%28photography%29
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A polarizing filter or polarising filter (see spelling differences) is often placed in front of the camera lens in photography in order to darken skies, manage reflections, or suppress glare from the surface of lakes or the sea. Since reflections (and sky-light) tend to be at least partially linearly-polarized, a linear polarizer can be used to change the balance of the light in the photograph. The rotational orientation of the filter is adjusted for the preferred artistic effect. For modern cameras, a circular polarizer (CPL) is typically used; this comprises firstly a linear polarizer which performs the artistic function just described, followed by a quarter-wave plate which further transforms the now-linearly polarized light into circularly-polarized light before entering the camera. This additional step avoids problems with autofocus and light-metering sensors within some cameras, which otherwise may not function reliably with a simple linear polarizer.
Use
Light reflected from a non-metallic surface becomes polarized; this effect is maximum at Brewster's angle, about 56° from the vertical for common glass. A polarizer rotated to pass only light polarized in the direction perpendicular to the reflected light will absorb much of it. This absorption allows glare reflected from, for example, a body of water or a road to be reduced. Reflections from shiny surfaces (e.g. vegetation, sweaty skin, water surfaces, glass) are also reduced. This allows the natural color and detail of what is beneath to come through. Reflections from a window into a dark interior can be much reduced, allowing it to be seen through. (The same effects are available for vision by using polarizing sunglasses.)
Some of the light coming from the sky is polarized (bees use this phenomenon for navigation).
The electrons in the air molecules cause a scattering of sunlight in all directions. This explains why the sky is not dark during the day. But when looked at from the sides, the light emitt
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https://en.wikipedia.org/wiki/Copy%20number%20variation
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Copy number variation (CNV) is a phenomenon in which sections of the genome are repeated and the number of repeats in the genome varies between individuals. Copy number variation is a type of structural variation: specifically, it is a type of duplication or deletion event that affects a considerable number of base pairs. Approximately two-thirds of the entire human genome may be composed of repeats and 4.8–9.5% of the human genome can be classified as copy number variations. In mammals, copy number variations play an important role in generating necessary variation in the population as well as disease phenotype.
Copy number variations can be generally categorized into two main groups: short repeats and long repeats. However, there are no clear boundaries between the two groups and the classification depends on the nature of the loci of interest. Short repeats include mainly dinucleotide repeats (two repeating nucleotides e.g. A-C-A-C-A-C...) and trinucleotide repeats. Long repeats include repeats of entire genes. This classification based on size of the repeat is the most obvious type of classification as size is an important factor in examining the types of mechanisms that most likely gave rise to the repeats, hence the likely effects of these repeats on phenotype.
Types and chromosomal rearrangements
One of the most well known examples of a short copy number variation is the trinucleotide repeat of the CAG base pairs in the huntingtin gene responsible for the neurological disorder Huntington's disease. For this particular case, once the CAG trinucleotide repeats more than 36 times in a trinucleotide repeat expansion, Huntington's disease will likely develop in the individual and it will likely be inherited by his or her offspring. The number of repeats of the CAG trinucleotide is inversely correlated with the age of onset of Huntington's disease. These types of short repeats are often thought to be due to errors in polymerase activity during replication includi
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https://en.wikipedia.org/wiki/Meristics
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Meristics is an area of zoology and botany which relates to counting quantitative features of animals and plants, such as the number of fins or scales in fish. A meristic (countable trait) can be used to describe a particular species, or used to identify an unknown species. Meristic traits are often described in a shorthand notation called a meristic formula.
Meristic characters are the countable structures occurring in series (e.g. myomeres, vertebrae, fin rays). These characters are among the characters most commonly used for differentiation of species and populations. In the salmonids, scale counts have been most widely used for the differentiation of populations within species. In rainbow and steelhead trout the most notable differences among populations occur in counts of scales. Meristic comparison is used in phenetic and cladistic analysis.
Meristic analysis
A meristic study is often a difficult task. For example, counting the features of a fish is not as easy as it may appear. Many meristic analyses are performed on dead fish that have been preserved in alcohol. Meristic traits are less easily observed on living fish, though it is possible. On very small fish, a microscope may be required.
Ichthyologists follow a basic set of rules when performing a meristic analysis, to remove as much ambiguity as possible. The specific practice, however, may vary depending on the type of fish. The methodology for counting meristic traits should be described by the specialist who performs the analysis.
Meristic formula
A meristic formula is a shorthand method of describing the way the bones (rays) of a bony fish's fins are arranged. It is comparable to the floral formula for flowers.
Spine counts are given in Roman numerals, e.g. XI-XIV. Ray counts are given in Arabic numerals, e.g. 11–14.
The meristic formula of the dusky spinefoot (Siganus luridus) is: D, XIV+10; A, VII+8-9; P, 16–17; V, I+3+I; GR, 18-22
This means the fish has 14 spiny rays (bones) in the first p
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https://en.wikipedia.org/wiki/Monitor%20mode
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Monitor mode, or RFMON (Radio Frequency MONitor) mode, allows a computer with a wireless network interface controller (WNIC) to monitor all traffic received on a wireless channel. Unlike promiscuous mode, which is also used for packet sniffing, monitor mode allows packets to be captured without having to associate with an access point or ad hoc network first. Monitor mode only applies to wireless networks, while promiscuous mode can be used on both wired and wireless networks. Monitor mode is one of the eight modes that 802.11 wireless adapter can operate in: Master (acting as an access point), Managed (client, also known as station), Ad hoc, Repeater, Mesh, Wi-Fi Direct, TDLS and Monitor mode.
Uses
Uses for monitor mode include: geographical packet analysis, observing of widespread traffic and acquiring knowledge of Wi-Fi technology through hands-on experience. It is especially useful for auditing unsecure channels (such as those protected with WEP). Monitor mode can also be used to help design Wi-Fi networks. For a given area and channel, the number of Wi-Fi devices currently being used can be discovered. This helps to create a better Wi-Fi network that reduces interference with other Wi-Fi devices by choosing the least used Wi-Fi channels.
Software such as KisMAC or Kismet, in combination with packet analyzers that can read pcap files, provide a user interface for passive wireless network monitoring.
Limitations
Usually the wireless adapter is unable to transmit in monitor mode and is restricted to a single wireless channel, though this is dependent on the wireless adapter's driver, its firmware, and features of its chipset. Also, in monitor mode the adapter does not check to see if the cyclic redundancy check (CRC) values are correct for packets captured, so some captured packets may be corrupted.
Operating system support
The Microsoft Windows Network Driver Interface Specification (NDIS) API has supported extensions for monitor mode since NDIS version
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https://en.wikipedia.org/wiki/Firefly%20%28key%20exchange%20protocol%29
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Firefly is a U.S. National Security Agency public-key key exchange protocol, used in EKMS, the STU-III secure telephone, and several other U.S. cryptographic systems.
References
Communications Security Custodian Guide, USAREUR Pamphlet 380-40
TACLANE-Micro Inline Network Encryptor Interface & Operator’s Guide
Cryptographic protocols
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https://en.wikipedia.org/wiki/Precompiled%20header
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In computer programming, a precompiled header (PCH) is a (C or C++) header file that is compiled into an intermediate form that is faster to process for the compiler. Usage of precompiled headers may significantly reduce compilation time, especially when applied to large header files, header files that include many other header files, or header files that are included in many translation units.
Rationale
In the C and C++ programming languages, a header file is a file whose text may be automatically included in another source file by the C preprocessor by the use of a preprocessor directive in the source file.
Header files can sometimes contain very large amounts of source code (for instance, the header files windows.h and Cocoa/Cocoa.h on Microsoft Windows and OS X, respectively). This is especially true with the advent of large "header" libraries that make extensive use of templates, like the Eigen math library and Boost C++ libraries. They are written almost entirely as header files that the user #includes, rather than being linked at runtime. Thus, each time the user compiles their program, the user is essentially recompiling numerous header libraries as well. (These would be precompiled into shared objects or dynamic link libraries in non "header" libraries.)
To reduce compilation times, some compilers allow header files to be compiled into a form that is faster for the compiler to process. This intermediate form is known as a precompiled header, and is commonly held in a file named with the extension .pch or similar, such as .gch under the GNU Compiler Collection.
Usage
For example, given a C++ file source.cpp that includes header.hpp:
//header.hpp
...
//source.cpp
#include "header.hpp"
...
When compiling source.cpp for the first time with the precompiled header feature turned on, the compiler will generate a precompiled header, header.pch. The next time, if the timestamp of this header did not change, the compiler can skip the compilation phase relat
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https://en.wikipedia.org/wiki/Sunsite
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SunSITE (Sun Software, Information & Technology Exchange) is a network of Internet servers providing archives of information, software and other publicly available resources. The project, started in the early 1990s, is run by a number of universities worldwide and was initially co-sponsored by Sun Microsystems.
The more notable SunSITEs include:
SunSITE Canada, operated by University of British Columbia = Found Without Content - 2022.04.28
SunSITE Central Europe, operated by RWTH Aachen, Germany
Sun SITE Central Europe Workshop Proceedings (CEUR-WS.org) Free Open-Access
SunSITE Poland, operated by ICM, University of Warsaw
Some former SunSITEs:
SunSITE Chile
SunSITE Czech Republic, operated by School of Computer Science, Charles University, Prague = Server Not Found - 2022.04.28
SunSITE Denmark, now running as dotsrc.org Open Source Hosting
SunSITE Mexico = Blank Page - 2022.04.28
SunSITE North Carolina, operated by University of North Carolina at Chapel Hill, now running as Ibiblio
SunSITE RedIris (Spain), operated by Spanish National Research Network = Server Not Found - 2022.04.28
SunSITE Singapore, operated by National University of Singapore = Blank Page - 2022.04.28
SunSITE Switzerland, operated by SWITCH Information Technology Services, now running as SWITCHmirror
SunSITE Tennessee operated by University of Tennessee, Knoxville = Server Not Found - 2022.04.28
SunSITE Thailand operated by Assumption University, Bangkok = Server Not Found - 2022.04.28
University of Alberta SunSITE, now running as the University of Alberta Digital Object Repository (UADORe)
No longer in operation:
SunSITE Austria , operated by University of Vienna
SunSITE Argentina, operated by Universidad de Buenos Aires.
Berkeley Digital Library SunSITE, University of California, Berkeley Libraries
SunSITE Hungary, run by Institute of Mathematics, University of Debrecen
SunSITE Indonesia, operated by Faculty of Computer Science, University of Indonesia, Jakarta
SunSIT
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https://en.wikipedia.org/wiki/Middlebox
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A middlebox is a computer networking device that transforms, inspects, filters, and manipulates traffic for purposes other than packet forwarding. Examples of middleboxes include firewalls, network address translators (NATs), load balancers, and deep packet inspection (DPI) devices.
UCLA computer science professor Lixia Zhang coined the term middlebox in 1999.
Usage
Middleboxes are widely deployed across both private and public networks. Dedicated middlebox hardware is widely deployed in enterprise networks to improve network security and performance, however, even home network routers often have integrated firewall, NAT, or other middlebox functionality. One 2017 study counting more than 1,000 deployments in autonomous systems, in both directions of traffic flows, and across a wide range networks, including mobile operators and data center networks.
Examples
The following are examples of commonly deployed middleboxes:
Firewalls filter traffic based on a set of predefined security rules defined by a network administrator. IP firewalls reject packets "based purely on fields in the IP and transport headers (e.g., disallow incoming traffic to certain port numbers, disallow any traffic to certain subnets etc.)" Other types of firewalls may use more complex rulesets, including those that inspect traffic at the session or application layer.
Intrusion detection systems (IDSs) monitor traffic and collect data for offline analysis for security anomalies. Unlike firewalls, IDSs do not filter packets in real time, as they are capable of more complex inspection and must decide whether to accept or reject each packet as it arrives.
Network address translators (NATs) replace the source and/or destination IP addresses of packets that traverse them. Typically, NATs are deployed to allow multiple end hosts to share a single IP address: hosts "behind" the NAT are assigned a private IP address and their packets destined to the public Internet traverse a NAT, which replaces th
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https://en.wikipedia.org/wiki/Advanced%20Programmable%20Interrupt%20Controller
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In computing, Intel's Advanced Programmable Interrupt Controller (APIC) is a family of interrupt controllers. As its name suggests, the APIC is more advanced than Intel's 8259 Programmable Interrupt Controller (PIC), particularly enabling the construction of multiprocessor systems. It is one of several architectural designs intended to solve interrupt routing efficiency issues in multiprocessor computer systems.
The APIC is a split architecture design, with a local component (LAPIC) usually integrated into the processor itself, and an optional I/O APIC on a system bus. The first APIC was the 82489DX it was a discrete chip that functioned both as local and I/O APIC. The 82489DX enabled construction of symmetric multiprocessor (SMP) systems with the Intel 486 and early Pentium processors; for example, the reference two-way 486 SMP system used three 82489DX chips, two as local APICs and one as I/O APIC. Starting with the P54C processor, the local APIC functionality was integrated into the Intel processors' silicon. The first dedicated I/O APIC was the Intel 82093AA, which was intended for PIIX3-based systems.
Overview
There are two components in the Intel APIC system, the local APIC (LAPIC) and the I/O APIC. There is one LAPIC in each CPU in the system. In the very first implementation (82489DX), the LAPIC was a discrete circuit, as opposed to its later implementation in Intel processors' silicon. There is typically one I/O APIC for each peripheral bus in the system. In original system designs, LAPICs and I/O APICs were connected by a dedicated APIC bus. Newer systems use the system bus for communication between all APIC components.
Each APIC, whether a discrete chip or integrated in a CPU, has a version register containing a four-bit version number for its specific APIC implementation. For example, the 82489DX has an APIC version number of 0, while version 1 was assigned to the first generation of local APICs integrated in the Pentium 90 and 100 processors.
In s
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https://en.wikipedia.org/wiki/IEEE%20854-1987
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The IEEE Standard for Radix-Independent Floating-Point Arithmetic (IEEE 854), was the first Institute of Electrical and Electronics Engineers (IEEE) international standard for floating-point arithmetic with radices other than 2, including radix 10. IEEE 854 did not specify any data formats, whereas IEEE 754-1985 did specify formats for binary (radix 2) floating point. IEEE 754-1985 and IEEE 854-1987 were both superseded in 2008 by IEEE 754-2008, which specifies floating-point arithmetic for both radix 2 (binary) and radix 10 (decimal), and specifies two alternative formats for radix 10 floating-point values, and even more so with IEEE 754-2019. IEEE 754-2008 also had many other updates to the IEEE floating-point standardisation.
IEEE 854 arithmetic was first commercially implemented in the HP-71B handheld computer, which used decimal floating point with 12 digits of significand, and an exponent range of ±499, with a 15 digit significand used for intermediate results.
References
External links
IEEE 854-1987 – History and minutes
Computer arithmetic
IEEE standards
Floating point
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https://en.wikipedia.org/wiki/Energy%20quality
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Energy quality is a measure of the ease with which a form of energy can be converted to useful work or to another form of energy: i.e. its content of thermodynamic free energy. A high quality form of energy has a high content of thermodynamic free energy, and therefore a high proportion of it can be converted to work; whereas with low quality forms of energy, only a small proportion can be converted to work, and the remainder is dissipated as heat. The concept of energy quality is also used in ecology, where it is used to track the flow of energy between different trophic levels in a food chain and in thermoeconomics, where it is used as a measure of economic output per unit of energy. Methods of evaluating energy quality often involve developing a ranking of energy qualities in hierarchical order.
Examples: Industrialization, Biology
The consideration of energy quality was a fundamental driver of industrialization from the 18th through 20th centuries. Consider for example the industrialization of New England in the 18th century. This refers to the construction of textile mills containing power looms for weaving cloth. The simplest, most economical and straightforward source of energy was provided by water wheels, extracting energy from a millpond behind a dam on a local creek. If another nearby landowner also decided to build a mill on the same creek, the construction of their dam would lower the overall hydraulic head to power the existing waterwheel, thus hurting power generation and efficiency. This eventually became an issue endemic to the entire region, reducing the overall profitability of older mills as newer ones were built. The search for higher quality energy was a major impetus throughout the 19th and 20th centuries. For example, burning coal to make steam to generate mechanical energy would not have been imaginable in the 18th century; by the end of the 19th century, the use of water wheels was long outmoded. Similarly, the quality of energy from elec
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https://en.wikipedia.org/wiki/Nerolidol
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Nerolidol, also known as peruviol and penetrol , is a naturally occurring sesquiterpene alcohol. A colorless liquid, it is found in the essential oils of many types of plants and flowers. There are four isomers of nerolidol', which differ in the geometry about the central double bond and configuration of the hydroxyl-bearing carbon, but most applications use such a mixture. The aroma of nerolidol is woody and reminiscent of fresh bark. It is used as a flavoring agent and in perfumery as well as in non-cosmetic products such as detergents and cleansers. Nerolidyl derivatives include nerolidyl diphosphate and the fragrance nerolidyl acetate.
Synthesis and occurrence
Nerolidol is produced commercially from geranylacetone by the addition of vinyl Grignard reagent. It is used as a source of farnesol, vitamin E, and vitamin K1.
Significant sources of natural nerolidol is Cabreuva oil and the oil of Dalbergia parviflora. It is also present in neroli, ginger, jasmine, lavender, tea tree, Cannabis sativa, and lemon grass, and is a dominant scent compound in Brassavola nodosa.
Further reading
See also
Linalool
Farnesol
References
Tertiary alcohols
Perfume ingredients
Flavors
Sesquiterpenes
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https://en.wikipedia.org/wiki/Scala%20%28programming%20language%29
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Scala ( ) is a strong statically typed high-level general-purpose programming language that is supporting both object-oriented programming and functional programming. Designed to be concise, many of Scala's design decisions are aimed to address criticisms of Java.
Scala source code can be compiled to Java bytecode and run on a Java virtual machine (JVM). Scala can also be compiled to JavaScript to run in a browser, or directly to a native executable. On the JVM Scala provides language interoperability with Java so that libraries written in either language may be referenced directly in Scala or Java code. Like Java, Scala is object-oriented, and uses a syntax termed curly-brace which is similar to the language C. Since Scala 3, there is also an option to use the off-side rule (indenting) to structure blocks, and its use is advised. Martin Odersky has said that this turned out to be the most productive change introduced in Scala 3.
Unlike Java, Scala has many features of functional programming languages (like Scheme, Standard ML, and Haskell), including currying, immutability, lazy evaluation, and pattern matching. It also has an advanced type system supporting algebraic data types, covariance and contravariance, higher-order types (but not higher-rank types), anonymous types, operator overloading, optional parameters, named parameters, raw strings, and an experimental exception-only version of algebraic effects that can be seen as a more powerful version of Java's checked exceptions.
The name Scala is a portmanteau of scalable and language, signifying that it is designed to grow with the demands of its users.
History
The design of Scala started in 2001 at the École Polytechnique Fédérale de Lausanne (EPFL) (in Lausanne, Switzerland) by Martin Odersky. It followed on from work on Funnel, a programming language combining ideas from functional programming and Petri nets. Odersky formerly worked on Generic Java, and javac, Sun's Java compiler.
After an internal rel
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https://en.wikipedia.org/wiki/Irma%20board
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Irma board, originally spelled IRMA board, refers to a brand of coaxial interface cards for PCs and Macintosh computers used to enable 3270 emulator programs to connect to IBM mainframe computers. IRMA boards were used to connect PCs and Macs to IBM 3274 terminal controllers.
IRMA boards supported both Control Unit Terminal (CUT) and Distributed Function Terminal (DFT) mode, although the later required additional software–DFT mode supported multiple simultaneous mainframe sessions.
IRMA boards were invented by Technical Analysis Corp. (TAC), acquired by Digital Communications Associates, Inc. (DCA) who manufactured and marketed the Irma products from 1982 on. DCA of Alpharetta, Georgia, was acquired in 1994 by Attachmate of Bellevue, Washington.
A board with all the capabilities of that which would eventually be called IRMA was originally developed in-house by Amdahl Corp in 1977, but it was not actively marketed by Amdahl.
See also
IBM 3270 PC
Avatar Technologies, Inc. (née 3R Computers), makers of the Mac Mainframe line of products allowing IBM 3270 emulation on the Macintosh SE and II
Terminal emulator
References
Mainframe computers
Computer-related introductions in 1982
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https://en.wikipedia.org/wiki/Obstack
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In the C programming language, Obstack is a memory-management GNU extension to the C standard library. An "obstack" is a "stack" of "objects" (data items) which is dynamically managed. It implements a region-based memory management scheme.
Obstack code typically provides C macros which take care of memory allocation and management for the user. Basically, obstacks are used as a form of memory management which can be more efficient and less difficult to implement than malloc/free in several situations. For example, say one needs to set up a stack for handling data items whose number grows for a while and then reach a final form; such a stack could be defined in obstack.h.
Freeing allocated objects
Once the object is allocated a new chunk of memory in obstack it must be freed after its use.
Functions and macros
The interfaces for using obstacks may be defined either as functions or as macros, depending on the compiler. The obstack facility works with all C compilers.
In an old-fashioned non-ISO C compiler, all the obstack functions are actually defined only as macros. You can call these macros like functions, but you cannot use them in any other way. For example, you cannot take their address.
Calling the macros requires a special precaution: namely, the first operand (the obstack pointer) should not contain any side effects, because it may be computed more than once.
In ISO C, each obstack function has both a macro definition and a function definition. The function definition is used if the macro substitution fails. An ordinary call uses the macro definition by default, but you can request the function definition instead by writing the function name in parentheses, as shown here:
char *x;
void *(*funcp)();
x = obstack_alloc(obptr, size); /* Use the macro. */
x = (obstack_alloc) (obptr, size); /* Call the function. */
funcp = obstack_alloc; /* Take the address of the function. */
This is the same situation that exists in ISO C for the standard library functio
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https://en.wikipedia.org/wiki/Papanicolaou%20stain
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Papanicolaou stain (also Papanicolaou's stain and Pap stain) is a multichromatic (multicolored) cytological staining technique developed by George Papanicolaou in 1942. The Papanicolaou stain is one of the most widely used stains in cytology, where it is used to aid pathologists in making a diagnosis. Although most notable for its use in the detection of cervical cancer in the Pap test or Pap smear, it is also used to stain non-gynecological specimen preparations from a variety of bodily secretions and from small needle biopsies of organs and tissues. Papanicolaou published three formulations of this stain in 1942, 1954, and 1960.
Usage
Pap staining is used to differentiate cells in smear preparations (in which samples are spread or smeared onto a glass microscope slide) from various bodily secretions and needle biopsies; the specimens may include gynecological smears (Pap smears), sputum, brushings, washings, urine, cerebrospinal fluid, abdominal fluid, pleural fluid, synovial fluid, seminal fluid, fine needle aspirations, tumor touch samples, or other materials containing loose cells.
The pap stain is not fully standardized and comes in several formulations, differing in the exact dyes used, their ratios, and timing of the process. Pap staining is usually associated with cytopathology in which loose cells are examined, but the stain has also been modified and used on tissue slices.
Pap test
Pap staining is used in the Pap smear (or Pap test) and is a reliable technique in cervical cancer screening in gynecology.
Generalized staining method
The classic form of the Papanicolaou stain involves five stains in three solutions.
The first staining solution contains haematoxylin which stains cell nuclei. Papanicolaou used Harris's hematoxylin in all three formulations of the stain he published.
The second staining solution (designated OG-6), contains Orange G in 95% ethyl alcohol with a small amount of phosphotungstic acid. In the OG-6, the OG signifies Orange
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https://en.wikipedia.org/wiki/Tony%20Tebby
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Tony Tebby is a computer programmer and the designer of Qdos, the computer operating system used in the Sinclair QL personal computer, while working as an engineer at Sinclair Research in the early 1980s.
He left Sinclair Research in 1984 in protest at the premature launch of the QL, and formed QJUMP Ltd., a software house specializing in system software and utilities for the QL, based in Rampton, Cambridgeshire, England.
Prior to this, he worked at the Philips Research Laboratories in Redhill, Surrey where he worked on realtime image processing, using electronic hardware rather than software. At that time, software would have been either a batch program on the PRL mainframe computer or, within the departmental laboratory, the Commodore PET.
Among the software developed by QJUMP was SuperToolkit II, a collection of extensions to Qdos and SuperBASIC; a Qdos floppy disk driver which became the de facto standard for the various third-party floppy disk interfaces sold for the QL; and the QJUMP Pointer Environment, which extended the primitive display windowing facility of Qdos into something approaching a full GUI. Tebby also received a commission to write a Qdos-like operating system for the Atari ST; this was called SMS2.
Tebby later moved to Le Grand-Pressigny, France, but continued his involvement in the QL user community. In the early 1990s, he developed SMSQ, a new Qdos-compatible OS, based on SMS2, for the Miracle Systems QXL, a QL emulator card for PCs. An enhanced version of SMSQ was ported to the Atari ST and various other QL emulators, being renamed SMSQ/E. He has also worked on Stella, an embedded operating system for 68000-series and ColdFire processors.
References
Computer programmers
Sinclair Research
Living people
Year of birth missing (living people)
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https://en.wikipedia.org/wiki/Colegio%20de%20Bi%C3%B3logos%20del%20Per%C3%BA
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Colegio de Biólogos del Perú or College of Biologists of Peru is a professional association in Peru. This college accepts only graduates in biology that have opted to be licensed through a special inter-university procedure called Licenciatura. It was founded in 1972 and its creation was sanctioned by Law.
According to Peruvian law, in order to work as a professional biologist one must be registered and be a dues-paying active member of the Colegio de Biólogos del Perú. It is governed by a National Dean or President, who is elected every two years by general elections, and presided over a National Council. The National Council is constituted by 18 Regional Councils. As of 2007 it had over 7,000 registered members nationwide; who must be active dues-paying members to exercise their right to vote. Regional Councils are headed by regional deans elected ( by popular vote in their respective circumscriptions) by biologists registered in those regions.
In 2006, Peruvian Congress passed Law 28847 that regulates the work of biologists and requires them to be duly registered in the Colegio de Biólogos del Perú in order to work for government, academia or the private world.
Past National Deans are Isabel Martos, Soledad Osorio, Sandro Chavez, Magdalena Pavlich, and Damisela Coz. The present National Dean is Ernesto Bustamante elected in April 2007 to serve the term 2007 - 2009.
See also
Education in Peru
References
External links
Website
Biology organizations
Professional associations based in Peru
1972 establishments in Peru
Science and technology in Peru
Scientific organisations based in Peru
Organizations established in 1972
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https://en.wikipedia.org/wiki/Gain%E2%80%93bandwidth%20product
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The gain–bandwidth product (designated as GBWP, GBW, GBP, or GB) for an amplifier is the product of the amplifier's bandwidth and the gain at which the bandwidth is measured.
For devices such as operational amplifiers that are designed to have a simple one-pole frequency response, the gain–bandwidth product is nearly independent of the gain at which it is measured; in such devices the gain–bandwidth product will also be equal to the unity-gain bandwidth of the amplifier (the bandwidth within which the amplifier gain is at least 1).
For an amplifier in which negative feedback reduces the gain to below the open-loop gain, the gain–bandwidth product of the closed-loop amplifier will be approximately equal to that of the open-loop amplifier.
According to S. Srinivasan, "The parameter characterizing the frequency dependence of the operational amplifier gain is the finite gain–bandwidth product (GB)."
Relevance to design
This quantity is commonly specified for operational amplifiers, and allows circuit designers to determine the maximum gain that can be extracted from the device for a given frequency (or bandwidth) and vice versa.
When adding LC circuits to the input and output of an amplifier the gain rises and the bandwidth decreases, but the product is generally bounded by the gain–bandwidth product.
Examples
If the GBWP of an operational amplifier is 1 MHz, it means that the gain of the device falls to unity at 1 MHz. Hence, when the device is wired for unity gain, it will work up to 1 MHz (GBWP = gain × bandwidth, therefore if BW = 1 MHz, then gain = 1) without excessively distorting the signal. The same device when wired for a gain of 10 will work only up to 100 kHz, in accordance with the GBW product formula. Further, if the maximum frequency of operation is 1 Hz, then the maximum gain that can be extracted from the device is 1.
We can also analytically show that for frequencies GBWP is constant.
Let be a first-order transfer function given by:
We will
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https://en.wikipedia.org/wiki/H%26E%20stain
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Hematoxylin and eosin stain (or haematoxylin and eosin stain or hematoxylin-eosin stain; often abbreviated as H&E stain or HE stain) is one of the principal tissue stains used in histology. It is the most widely used stain in medical diagnosis and is often the gold standard. For example, when a pathologist looks at a biopsy of a suspected cancer, the histological section is likely to be stained with H&E.
H&E is the combination of two histological stains: hematoxylin and eosin. The hematoxylin stains cell nuclei a purplish blue, and eosin stains the extracellular matrix and cytoplasm pink, with other structures taking on different shades, hues, and combinations of these colors. Hence a pathologist can easily differentiate between the nuclear and cytoplasmic parts of a cell, and additionally, the overall patterns of coloration from the stain show the general layout and distribution of cells and provides a general overview of a tissue sample's structure. Thus, pattern recognition, both by expert humans themselves and by software that aids those experts (in digital pathology), provides histologic information.
This stain combination was introduced in 1877 by chemist N. Wissozky at the Kasan Imperial University in Russia.
Uses
The H&E staining procedure is the principal stain in histology in part because it can be done quickly, is not expensive, and stains tissues in such a way that a considerable amount of microscopic anatomy is revealed, and can be used to diagnose a wide range of histopathologic conditions. The results from H&E staining are not overly dependent on the chemical used to fix the tissue or slight inconsistencies in laboratory protocol, and these factors contribute to its routine use in histology.
H&E staining does not always provide enough contrast to differentiate all tissues, cellular structures, or the distribution of chemical substances, and in these cases more specific stains and methods are used.
Method of application
There are many ways to pr
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https://en.wikipedia.org/wiki/High-speed%20multimedia%20radio
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High-speed multimedia radio (HSMM) is the implementation of high-speed wireless TCP/IP data networks over amateur radio frequency allocations using commercial off-the-shelf (COTS) hardware such as 802.11 Wi-Fi access points. This is possible because the 802.11 unlicensed frequency bands partially overlap with amateur radio bands and ISM bands in many countries. Only licensed amateur radio operators may legally use amplifiers and high-gain antennas within amateur radio frequencies to increase the power and coverage of an 802.11 signal.
Basics
The idea behind this implementation is to modify commercial 802.11 equipment for use on licensed Amateur Radio frequencies. The main frequency bands being used for these networks are: 900 MHz (33 cm), 2.4 GHz (13 cm), 3.4 GHz (9 cm), and 5.8 GHz (5 cm). Since the unlicensed 802.11 or Wi-Fi frequency bands overlap with amateur frequencies, only custom firmware is needed to access these licensed frequencies.
Such networks can be used for emergency communications for disaster relief operations as well as in everyday amateur radio communications (hobby/social).
Capabilities
HSMM can support most of the traffic that the Internet currently does, including video chat, voice, instant messaging, email, the Web (HTTP), file transfer (FTP), and forums. The only differences being that with HSMM, such services are community instead of commercially implemented and it is mostly wireless. HSMM can even be connected to the Internet and used for web surfing, although because of the FCC regulations on permitted content, this is done only when directly used for ham radio activities (under Part 97). Using high gain directional antennas and amplifiers, reliable long-distance wireless links over many miles are possible and only limited by propagation and the radio horizon.
Bandwidths and Speeds
HSMM networks most-often use professional hardware with narrower channel bandwidths such as 5 or 10 MHz to help increase range. It is common for network
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https://en.wikipedia.org/wiki/Double%20descent
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In statistics and machine learning, double descent is the phenomenon where a statistical model with a small number of parameters and a model with an extremely large number of parameters have a small error, but a model whose number of parameters is about the same as the number of data points used to train the model will have a large error. It was discovered around 2018 when researchers were trying to reconcile the bias-variance tradeoff in classical statistics, which states that having too many parameters will yield an extremely large error, with the 2010s empirical observation of machine learning practitioners that the larger models are, the better they work. The scaling behavior of double descent has been found to follow a broken neural scaling law functional form.
References
Further reading
External links
Model selection
Machine learning
Statistical classification
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https://en.wikipedia.org/wiki/VIATRA
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VIATRA
is an open-source model transformation framework based on the Eclipse Modeling Framework (EMF) and hosted by the Eclipse Foundation.
VIATRA supports the development of model transformations with specific focus on event-driven,
reactive transformations, i.e., rule-based scenarios where transformations occur as reactions to
certain external changes in the model.
Building upon an incremental query support for locating patterns
and changes in the model,
VIATRA offers a language (the VIATRA Query Language, VQL) to define transformations and a reactive transformation
engine to execute certain transformations upon changes in the underlying model.
Application domains
VIATRA, as an open-source framework offering, serves as a central
integration point and enabler engine in various applications, both in an industrial and in an academic context. Earlier versions of the framework have been intensively used for providing tool support for developing and verifying critical embedded systems in numerous European research projects such as DECOS, MOGENTES, INDEXYS and SecureChange.
As a major industrial application of VIATRA, it is utilized as the underlying model querying and transformation engine of the IncQuery Suite. Thus, VIATRA is a key technical component in several industrial collaborations around model-based systems engineering (MBSE), fostering innovative systems engineering practices in domains like aerospace, manufacturing, industrial automation and automotive. Furthermore, via the applications of the IncQuery Suite, VIATRA serves as the foundation for model-based endeavors of ongoing, large-scale European industrial digitalization endeavors, such as the Arrowhead Tools and the Embrace projects.
VIATRA is well integrated with Eclipse Modeling tools. However, VIATRA works outside the Eclipse environment as well, as demonstrated by the IncA project using the JetBrains MPS platform.
Functionality
VIATRA provides the following main services:
An increme
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https://en.wikipedia.org/wiki/NetApp%20FAS
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A NetApp FAS is a computer storage product by NetApp running the ONTAP operating system; the terms ONTAP, AFF, ASA, FAS are often used as synonyms. "Filer" is also used as a synonym although this is not an official name. There are three types of FAS systems: Hybrid, All-Flash, and All SAN Array:
NetApp proprietary custom-build hardware appliances with HDD or SSD drives called hybrid Fabric-Attached Storage (or simply FAS)
NetApp proprietary custom-build hardware appliances with only SSD drives and optimized ONTAP for low latency called ALL-Flash FAS (or simply AFF)
All SAN Array build on top of AFF platform, and provide only SAN-based data protocol connectivity.
ONTAP can serve storage over a network using file-based protocols such as NFS and SMB, also block-based protocols, such as the SCSI over the Fibre Channel Protocol on a Fibre Channel network, Fibre Channel over Ethernet (FCoE), iSCSI, and FC-NVMe transport layer. ONTAP-based systems that can serve both SAN and NAS protocols called Unified ONTAP, AFF systems with ASA identity called All-SAN.
NetApp storage systems running ONTAP implement their physical storage in large disk arrays.
While most large-storage systems are implemented with commodity computers with an operating system such as Microsoft Windows Server, VxWorks or tuned Linux, ONTAP-based hardware appliances use highly customized hardware and the proprietary Data ONTAP operating system with WAFL file system, all originally designed by NetApp founders David Hitz and James Lau specifically for storage-serving purposes. ONTAP is NetApp's internal operating system, specially optimized for storage functions at high and low levels. It boots from FreeBSD as a stand-alone kernel-space module and uses some functions of FreeBSD (command interpreter and drivers stack, for example).
All NetApp ONTAP-based hardware appliances have battery-backed non-volatile random access memory or NVDIMM, referred to as NVRAM or NVDIMM, which allows them to commit writes
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https://en.wikipedia.org/wiki/Ethyl%20maltol
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Ethyl maltol is an organic compound that is a common flavourant in some confectioneries. It is related to the more common flavorant maltol by replacement of the methyl group by an ethyl group. It is a white solid with a sweet smell that can be described as caramelized sugar or as caramelized fruit.
The conjugate base derived from ethylmaltol, again like maltol, has a high affinity for iron, forming a red coordination complex. In such compounds, the heterocycle is a bidentate ligand.
Original patent:
References
Flavors
Flavor enhancers
Perfume ingredients
4-Pyrones
Enols
Sweet-smelling chemicals
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