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https://en.wikipedia.org/wiki/Robert%20S.%20Harris%20%28programmer%29
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Robert S. Harris, nicknamed RoSHa, is the designer and programmer of several 1980s home computer and console games, including War Room (ColecoVision, 1983) and Killer Bees! (Odyssey 2, 1983).
Early life
Harris was born in Boalsburg, Pennsylvania and graduated from Carnegie Mellon University with a Bachelor of Science in Mathematics in 1979.
Works
Killer Bees! (1983)
References
External links
Harris's web page
Video game designers
Video game programmers
Living people
Year of birth missing (living people)
Carnegie Mellon University alumni
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https://en.wikipedia.org/wiki/Gluing%20axiom
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In mathematics, the gluing axiom is introduced to define what a sheaf on a topological space must satisfy, given that it is a presheaf, which is by definition a contravariant functor
to a category which initially one takes to be the category of sets. Here is the partial order of open sets of ordered by inclusion maps; and considered as a category in the standard way, with a unique morphism
if is a subset of , and none otherwise.
As phrased in the sheaf article, there is a certain axiom that must satisfy, for any open cover of an open set of . For example, given open sets and with union and intersection , the required condition is that
is the subset of With equal image in
In less formal language, a section of over is equally well given by a pair of sections : on and respectively, which 'agree' in the sense that and have a common image in under the respective restriction maps
and
.
The first major hurdle in sheaf theory is to see that this gluing or patching axiom is a correct abstraction from the usual idea in geometric situations. For example, a vector field is a section of a tangent bundle on a smooth manifold; this says that a vector field on the union of two open sets is (no more and no less than) vector fields on the two sets that agree where they overlap.
Given this basic understanding, there are further issues in the theory, and some will be addressed here. A different direction is that of the Grothendieck topology, and yet another is the l
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https://en.wikipedia.org/wiki/Paul%20Motwani
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Paul Motwani (born 13 June 1962) is a Scottish chess grandmaster. He was the first Scottish player to become a grandmaster.
Chess career
Born in Glasgow and raised in Dundee, he became World Cadet (Under 17) Champion in 1978, and won the first of his seven Scottish Championship titles that year. He was a secondary school mathematics teacher at St Saviour's RC High School in Dundee for a number of years after studying mathematics and physics at the University of Dundee. In 1990, he took time out to pursue his final Grandmaster norm.
Motwani has been a regular member of the Scottish Olympiad, never having had a performance rating below 2500. He made his first two Grandmaster norms at the 1986 and 1988 Olympiads, then faced a race against time to achieve his third before the first one expired in 1991. (Although norms now last a lifetime, the FIDE rule in place at the time saw them expiring after five years.) He just failed to reach the required number of points in a hastily organised tournament in Dundee days before the deadline, ironically, FIDE changed the rules shortly after this, and reset the expiry time for norms at six years. He duly achieved his final norm in 1992, and starred in a Grampian Television documentary called "The Grandmasters of Dundee" along with Colin McNab, who had also achieved the title by then.
Motwani is a regular contributor to Scottish Chess (the magazine of Chess Scotland), The Scotsman (for whom he writes a weekly column) and has written for man
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https://en.wikipedia.org/wiki/Folk%20theorem
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Folk theorem may refer to:
Folk theorem (game theory), a general feasibility theorem
Ethnomathematics, the study of the relationship between mathematics and culture
Mathematical folklore, theorems that are widely known to mathematicians but cannot be traced back to an individual
Mathematics disambiguation pages
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https://en.wikipedia.org/wiki/VSR
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VSR may refer to:
VSR-10 rifles by Tokyo Marui
VSR V8 Trophy, a stock car racing series
V&S Railway, Kansas, USA, reporting mark
Voltage-sensitive relay in electronics
Variable shunt reactor, high voltage stabilizer
Very Special Relativity in physics
Very short patch repair in DNA
Victorian Scottish Regiment, Australia
Virtual Super Resolution on AMD graphics cards
Video Super Resolution on Nvidia graphics cards
Vibratory Stress Relief in mechanical engineering
Vincenzo Sospiri Racing, an Italian auto racing team
Video super-resolution, video upscaling technique
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https://en.wikipedia.org/wiki/Bj%C3%B8rn%20Grinde
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Bjørn Grinde (homepage grinde.one) is a Norwegian biologist working as a scientist in the fields of genetics and evolution, with particular interests in human evolution, happiness and consciousness.
Early life and education
He was born and grew up in Oslo, Norway, but spent a year as a high-school exchange student at Michigan, USA, in 1969.
He studied natural sciences as well as psychology, anthropology, and pedagogics at the University of Oslo, resulting in a Dr.scient (1981) and a Dr.philos (1984) in biology from the same university.
Work roles
Grinde has worked as a scientist and professor at leading universities in Norway, USA and Japan.
As of 2021, he works as a senior scientist at the Division of Mental and Physical Health, Norwegian Institute of Public Health.
Areas of interest and research
Molecular evolution
Some of his earlier projects focused on molecular evolution, using viruses as a model system.
Consciousness and happiness
For the later part of his career, the focus has been on understanding how evolution has shaped the human brain with particular reference to what consciousness is and why it serves us positive and negative experiences. The work is related to human behavioral biology (also referred to as evolutionary psychology). The idea us to find ways to improve mental health and quality of life. The approach is based on the idea that natural selection has shaped the human brain. Consequently, our evolutionary history has an impact on present behavio
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https://en.wikipedia.org/wiki/Regge%20theory
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In quantum physics, Regge theory () is the study of the analytic properties of scattering as a function of angular momentum, where the angular momentum is not restricted to be an integer multiple of ħ but is allowed to take any complex value. The nonrelativistic theory was developed by Tullio Regge in 1959.
Details
The simplest example of Regge poles is provided by the quantum mechanical treatment of the Coulomb potential or, phrased differently, by the quantum mechanical treatment of the binding or scattering of an electron of mass and electric charge off a proton of mass and charge . The energy of the binding of the electron to the proton is negative whereas for scattering the energy is positive. The formula for the binding energy is the expression
where , is the Planck constant, and is the permittivity of the vacuum. The principal quantum number is in quantum mechanics (by solution of the radial Schrödinger equation) found to be given by , where is the radial quantum number and the quantum number of the orbital angular momentum. Solving the above equation for , one obtains the equation
Considered as a complex function of this expression describes in the complex -plane a path which is called a Regge trajectory. Thus in this consideration the orbital
momentum can assume complex values.
Regge trajectories can be obtained for many other potentials, in particular also for the Yukawa potential.
Regge trajectories appear as poles of the scattering amplitude or
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https://en.wikipedia.org/wiki/Spherical%203-manifold
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In mathematics, a spherical 3-manifold M is a 3-manifold of the form
where is a finite subgroup of SO(4) acting freely by rotations on the 3-sphere . All such manifolds are prime, orientable, and closed. Spherical 3-manifolds are sometimes called elliptic 3-manifolds or Clifford-Klein manifolds.
Properties
A spherical 3-manifold has a finite fundamental group isomorphic to Γ itself. The elliptization conjecture, proved by Grigori Perelman, states that conversely all compact 3-manifolds with finite fundamental group are spherical manifolds.
The fundamental group is either cyclic, or is a central extension of a dihedral, tetrahedral, octahedral, or icosahedral group by a cyclic group of even order. This divides the set of such manifolds into 5 classes, described in the following sections.
The spherical manifolds are exactly the manifolds with spherical geometry, one of the 8 geometries of Thurston's geometrization conjecture.
Cyclic case (lens spaces)
The manifolds with Γ cyclic are precisely the 3-dimensional lens spaces. A lens space is not determined by its fundamental group (there are non-homeomorphic lens spaces with isomorphic fundamental groups); but any other spherical manifold is.
Three-dimensional lens spaces arise as quotients of by
the action of the group that is generated by elements of the form
where . Such a lens space has fundamental group for all , so spaces with different are not homotopy equivalent.
Moreover, classifications up to homeomor
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https://en.wikipedia.org/wiki/SVR
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SVR may refer to:
Biology and medicine
Systemic vascular resistance
Sustained viral response in hepatitis C treatment
Companies and organizations
, or in English the Foreign Intelligence Service (Russia)
Second Vermont Republic, a US secessionist group
Reykjavík bus company merged into Strætó bs
SV Ried, an Austrian soccer club
SVR Producciones, a Chilean record label
Sons of Veterans Reserve, of the Sons of Union Veterans of the Civil War
Finance
Scottish variable rate of income tax
Standard variable rate for mortgages
Media
WWE 2K, formerly WWE Smackdown VS. Raw.
WWE Smackdown! VS. Raw (2004 video game)
WWE SmackDown! vs. Raw 2006
WWE SmackDown vs. Raw 2007
WWE SmackDown vs. Raw 2008
WWE SmackDown vs. Raw 2009
WWE SmackDown vs. Raw 2010
WWE SmackDown vs. Raw 2011
Technology
Super Video Recording in Video Cassette Recording
UNIX System V Release
Subvocal recognition
Support vector regression
Transportation and vehicles
Automotive
Jaguar R and SVR models of cars
Not to be confused with: SVO (Special Vehicle Operations)
Railway
Severn Valley Railway, England
Spa Valley Railway, England
Aerospace
Savissivik Heliport, Greenland
Other uses
The SAME code for a severe thunderstorm warning
S. V. Ranga Rao, Indian cinema actor
See also
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https://en.wikipedia.org/wiki/Residual%20block%20termination
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In cryptography, residual block termination is a variation of cipher block chaining mode (CBC) that does not require any padding. It does this by effectively changing to cipher feedback mode for one block. The cost is the increased complexity.
Encryption procedure
If the plaintext length N is not a multiple of the block size L:
Encrypt the ⌊N/L⌋ full blocks of plaintext using the cipher block chaining mode;
Encrypt the last full encrypted block again;
XOR the remaining bits of the plaintext with leftmost bits of the re-encrypted block.
Decryption procedure
Decrypt the ⌊N/L⌋ full encrypted blocks using the Cipher Block Chaining mode;
Encrypt the last full encrypted block;
XOR the remaining bits of the ciphertext with leftmost bits of the re-encrypted block.
Short message
For messages shorter than one block, residual block termination can use an encrypted initialization vector instead of the previously encrypted block.
Cryptographic algorithms
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https://en.wikipedia.org/wiki/ChorusOS
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ChorusOS is a microkernel real-time operating system designed as a message passing computing model. ChorusOS began as the Chorus distributed real-time operating system research project at the French Institute for Research in Computer Science and Automation (INRIA) in 1979. During the 1980s, Chorus was one of two earliest microkernels (the other being Mach) and was developed commercially by startup company Chorus Systèmes SA. Over time, development effort shifted away from distribution aspects to real-time for embedded systems.
In 1997, Sun Microsystems acquired Chorus Systèmes for its microkernel technology, which went toward the new JavaOS. Sun (and henceforth Oracle) no longer supports ChorusOS. The founders of Chorus Systèmes started a new company called Jaluna in August 2002. Jaluna then became VirtualLogix, which was then acquired by Red Bend in September 2010. VirtualLogix designed embedded systems using Linux and ChorusOS (which they named VirtualLogix C5). C5 was described by them as a carrier grade operating system, and was actively maintained by them.
The latest source tree of ChorusOS, an evolution of version 5.0, was released as open-source software by Sun and is available at the Sun Download Center. The Jaluna project has completed these sources and published it online. Jaluna-1 is described there as a real-time Portable Operating System Interface (RT-POSIX) layer based on FreeBSD 4.1, and the CDE cross-platform software development environment. ChorusOS is sup
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https://en.wikipedia.org/wiki/Robert%20Drost
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Robert Drost is an American computer scientist. He was born in 1970 in New York City.
Life
Drost joined Sun Microsystems in 1993 after obtaining a B.S. and M.S. in Electrical Engineering from Stanford University. In 2001 he earned a Ph.D. in Electrical Engineering and a Ph.D. minor in Computer Science from Stanford. As of 2011 he is a holder of over 95 patents in microelectronics.
Until 2010, Drost was Distinguished Engineer and Senior Director of Advanced Hardware at Sun Microsystems, helping to pioneer wireless connections between computer chips called proximity communication.
Since 2010, Drost has had various roles, including CEO, COO, and CFO, at Pluribus Networks, Inc., a Palo Alto-based startup that he co-founded with Sunay Tripathi and Chih-Kong Ken Yang.
Distinctions
Awarded Best Paper at Supercomputing 2008, the International Conference for High Performance Computing, Networking, Storage, and Analysis.
Named to the MIT Technology Review TR100 as one of the top 100 innovators in the world under the age of 35.
Wall Street Journal Gold Medal for Innovation in Computing Systems.
Judge for the Wall Street Journal's Technology Innovation Awards since 2005.
References
External links
New York Times Article on Proximity Communication
VLSI Research group publications, Oracle (previously Sun Microsystems) Labs
American computer scientists
Living people
21st-century American businesspeople
Stanford University alumni
1970 births
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https://en.wikipedia.org/wiki/Mohs
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Mohs or MoHS can refer to:
Friedrich Mohs, a 19th-century German geologist who developed:
Mohs scale, a scale used in materials science to describe hardness
Frederic E. Mohs, an American doctor who developed:
Mohs surgery, a microscopically controlled surgery highly effective for common types of skin cancer
Erik Mohs, a German professional racing cyclist
Mohs Automobile, an automobile built by the American Mohs Seaplane Corporation
Moanalua High School, a public, co-educational college preparatory high school in Hawaiʻi
The Melancholy of Haruhi Suzumiya, a 2006 anime sci-fi television series
Mount Olive High School, a U.S. public high school in Flanders, New Jersey
Ministry of Health and Sports (Myanmar), a ministry of the government of Myanmar
See also
Mho, an alternative name for the Siemens (unit)
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https://en.wikipedia.org/wiki/Grete%20Hermann
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Grete Hermann (2 March 1901 – 15 April 1984) was a German mathematician and philosopher noted for her work in mathematics, physics, philosophy and education. She is noted for her early philosophical work on the foundations of quantum mechanics, and is now known most of all for an early, but long-ignored critique of a "no hidden-variables theorem" by John von Neumann. It has been suggested that, had her critique not remained nearly unknown for decades, the historical development of quantum mechanics might have been very different.
Mathematics
Hermann studied mathematics at Göttingen under Emmy Noether and Edmund Landau, where she achieved her PhD in 1926. Her doctoral thesis, "Die Frage der endlich vielen Schritte in der Theorie der Polynomideale" (in English "The Question of Finitely Many Steps in Polynomial Ideal Theory"), published in Mathematische Annalen, is the foundational paper for computer algebra. It first established the existence of algorithms (including complexity bounds) for many of the basic problems of abstract algebra, such as ideal membership for polynomial rings. Hermann's algorithm for primary decomposition is still in contemporary use.
Assistant to Leonard Nelson
From 1925 to 1927, Hermann worked as assistant for Leonard Nelson. Together with Minna Specht, she posthumously published Nelson's work System der philosophischen Ethik und Pädagogik, while continuing her own research.
Quantum mechanics
As a philosopher, Hermann had a particular interest
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https://en.wikipedia.org/wiki/Primary%20decomposition
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In mathematics, the Lasker–Noether theorem states that every Noetherian ring is a Lasker ring, which means that every ideal can be decomposed as an intersection, called primary decomposition, of finitely many primary ideals (which are related to, but not quite the same as, powers of prime ideals). The theorem was first proven by for the special case of polynomial rings and convergent power series rings, and was proven in its full generality by .
The Lasker–Noether theorem is an extension of the fundamental theorem of arithmetic, and more generally the fundamental theorem of finitely generated abelian groups to all Noetherian rings. The theorem plays an important role in algebraic geometry, by asserting that every algebraic set may be uniquely decomposed into a finite union of irreducible components.
It has a straightforward extension to modules stating that every submodule of a finitely generated module over a Noetherian ring is a finite intersection of primary submodules. This contains the case for rings as a special case, considering the ring as a module over itself, so that ideals are submodules. This also generalizes the primary decomposition form of the structure theorem for finitely generated modules over a principal ideal domain, and for the special case of polynomial rings over a field, it generalizes the decomposition of an algebraic set into a finite union of (irreducible) varieties.
The first algorithm for computing primary decompositions for polynomial rings
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https://en.wikipedia.org/wiki/Three-body%20problem
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In physics and classical mechanics, the three-body problem is the problem of taking the initial positions and velocities (or momenta) of three point masses and solving for their subsequent motion according to Newton's laws of motion and Newton's law of universal gravitation. The three-body problem is a special case of the -body problem. Unlike two-body problems, no general closed-form solution exists, as the resulting dynamical system is chaotic for most initial conditions, and numerical methods are generally required.
Historically, the first specific three-body problem to receive extended study was the one involving the Moon, Earth, and the Sun. In an extended modern sense, a three-body problem is any problem in classical mechanics or quantum mechanics that models the motion of three particles.
Mathematical description
The mathematical statement of the three-body problem can be given in terms of the Newtonian equations of motion for vector positions of three gravitationally interacting bodies with masses :
where is the gravitational constant. This is a set of nine second-order differential equations. The problem can also be stated equivalently in the Hamiltonian formalism, in which case it is described by a set of 18 first-order differential equations, one for each component of the positions and momenta :
where is the Hamiltonian:
In this case is simply the total energy of the system, gravitational plus kinetic.
Restricted three-body problem
In the restricted th
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https://en.wikipedia.org/wiki/Proximate%20and%20ultimate%20causation
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A proximate cause is an event which is closest to, or immediately responsible for causing, some observed result. This exists in contrast to a higher-level ultimate cause (or distal cause) which is usually thought of as the "real" reason something occurred.
The concept is used in many fields of research and analysis, including data science and ethology.
Example: Why did the ship sink?
Proximate cause: Because it was holed beneath the waterline, water entered the hull and the ship became denser than the water which supported it, so it could not stay afloat.
Ultimate cause: Because the ship hit a rock which tore open the hole in the ship's hull.
In most situations, an ultimate cause may itself be a proximate cause in comparison to a further ultimate cause. Hence we can continue the above example as follows:
Example: Why did the ship hit the rock?
Proximate cause: Because the ship failed to change course to avoid it.
Ultimate cause: Because the ship was under autopilot and the autopilot's data was inaccurate.
(even stronger): Because the shipwrights made mistakes in the ship's construction.
(stronger yet): Because the scheduling of labor at the shipyard allows for very little rest.
(in absurdum): Because the shipyard's owners have very small profit margins in an ever-shrinking market.
In biology
Ultimate causation explains traits in terms of evolutionary forces acting on them.
Example: female animals often display preferences among male display traits, such as so
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https://en.wikipedia.org/wiki/Variational%20Bayesian%20methods
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Variational Bayesian methods are a family of techniques for approximating intractable integrals arising in Bayesian inference and machine learning. They are typically used in complex statistical models consisting of observed variables (usually termed "data") as well as unknown parameters and latent variables, with various sorts of relationships among the three types of random variables, as might be described by a graphical model. As typical in Bayesian inference, the parameters and latent variables are grouped together as "unobserved variables". Variational Bayesian methods are primarily used for two purposes:
To provide an analytical approximation to the posterior probability of the unobserved variables, in order to do statistical inference over these variables.
To derive a lower bound for the marginal likelihood (sometimes called the evidence) of the observed data (i.e. the marginal probability of the data given the model, with marginalization performed over unobserved variables). This is typically used for performing model selection, the general idea being that a higher marginal likelihood for a given model indicates a better fit of the data by that model and hence a greater probability that the model in question was the one that generated the data. (See also the Bayes factor article.)
In the former purpose (that of approximating a posterior probability), variational Bayes is an alternative to Monte Carlo sampling methods—particularly, Markov chain Monte Carlo methods
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https://en.wikipedia.org/wiki/Bicyclic%20semigroup
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In mathematics, the bicyclic semigroup is an algebraic object important for the structure theory of semigroups. Although it is in fact a monoid, it is usually referred to as simply a semigroup. It is perhaps most easily understood as the syntactic monoid describing the Dyck language of balanced pairs of parentheses. Thus, it finds common applications in combinatorics, such as describing binary trees and associative algebras.
History
The first published description of this object was given by Evgenii Lyapin in 1953. Alfred H. Clifford and Gordon Preston claim that one of them, working with David Rees, discovered it independently (without publication) at some point before 1943.
Construction
There are at least three standard ways of constructing the bicyclic semigroup, and various notations for referring to it. Lyapin called it P; Clifford and Preston used ; and most recent papers have tended to use B. This article will use the modern style throughout.
From a free semigroup
The bicyclic semigroup is the quotient of the free monoid on two generators p and q by the congruence generated by the relation p q = 1. Thus, each semigroup element is a string of those two letters, with the proviso that the subsequence "p q" does not appear.
The semigroup operation is concatenation of strings, which is clearly associative.
It can then be shown that all elements of B in fact have the form qa pb, for some natural numbers a and b. The composition operation simplifies to
(qa pb) (qc pd
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https://en.wikipedia.org/wiki/Ivanovo%20State%20University%20of%20Chemistry%20and%20Technology
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The Ivanovo State University of Chemistry and Technology () or ISUCT () is a public university located in Ivanovo, the administrative center of Ivanovo Oblast, Russia. Research priorities of the ISUCT are concentrated in chemical technology, chemistry and engineering.
The ISUCT takes the first place among universities in the Ivanovo region in the national ranking of universities.
History
It was founded in 1918 as Chemical Faculty of Ivanovo-Vosnesensk Polytechnic Institute. In 1930, Ivanovo-Vosnessensk Polytechnic Institute was split into four independent schools: Ivanovo Textile Institute, Ivanovo Power Institute, Civil Engineering Institute, and Ivanovo Institute of Chemistry and Technology (ICTI). The latter gained a new status in 1992 and was renamed to Ivanovo State Academy of Chemistry and Technology, and in 1998 it was renamed again, becoming Ivanovo State University of Chemistry and Technology.
Education
The ISUCT has a multi-level system of higher education: bachelor – 4 years, master – 2 years, post-graduate – 3–4 years, pre-university programs for foreign students – 1 year. ISUCT provides training in a range of engineering, technological, and natural sciences directions.
Today ISUCT is a team of academic and research staff, including honored workers of science, of education and culture, laureates of state and government awards, honorary doctors and professors from European universities, honorary workers of higher professional education of the Russian Federati
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https://en.wikipedia.org/wiki/Standard%20form
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Standard form may refer to a way of writing very large or very small numbers by comparing the powers of ten. It is also known as scientific notation. Numbers in standard form are written in this format: a×10n
Where a is a number 1 ≤ a < 10 and n is an integer.
ln mathematics and science
Canonical form
Standard form (Ax + By = C) – a common form of a linear equation
The more common term for normalised scientific notation in British English and Caribbean English
In government
Standard Form (SF) is the name of a set of forms used in the U.S. Federal Government for a wide variety of purposes, dozens of such forms are listed on the United States Office of Personnel Management website. For one example: Standard Form 50 (or SF-50), is a Notification of Personnel Action, maintained by the National Personnel Records Center of the National Archives and Records Administration (NARA).
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https://en.wikipedia.org/wiki/Martin-Andersen-Nex%C3%B6-Gymnasium%20Dresden
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The Martin-Andersen-Nexö-Gymnasium Dresden (MANOS) is a selective high school (gymnasium) in Dresden, Germany, with a special focus on mathematics and sciences. It was formerly the school for radio mechanics in the GDR. It is named after the Danish writer Martin Andersen Nexø.
The current head of school is Mr. Holm Wieczoreck.
History
1903 Creation of classes for secondary education at the Bürgerschule Blasewitz
1904 Planning for own school building
1907 Start of the construction
1908 Inauguration of the new school building as Realgymnasium Blasewitz on April 30, 1908
1938 Renaming to Schillerschule Blasewitz
1945 Anglo-American air raid on Dresden on February 13, 1945, damages the roof of the school building
1945 Resumption of classes on October 1, 1945 as the Oberschule Dresden-Ost, housed in various buildings, with separate classes for boys and girls
1947 First mixed classes on September 1, 1947
1949 Complete co-education
1954 Renaming to Martin-Andersen-Nexö-Oberschule
1963 School for radio mechanics
1964 School for electronics industry
1969 Inauguration of the Martin Andersen Nexö Memorial on June 26, 1969
1986 Selective school for mathematics and sciences
1992 Foundation of Gymnasium Dresden-Blasewitz in Seidnitz (in the former 94th Polytechnic Secondary School) with a branch campus for advanced mathematics and science courses in the Kretschmerstraße
1998 The building in the Kretschmerstraße becomes the main campus of the Gymnasium Dresden-Blasewitz
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https://en.wikipedia.org/wiki/Serhiy%20Komisarenko
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Serhiy Vasylʹovych Komisarenko (; , Sergey Vasilyovich Komissarenko), born July 9, 1943, in Ufa, Bashkortostan, USSR is a Ukrainian scientist, politician, and diplomat. He was a self-nominated candidate in the 2004 Ukrainian presidential election, and is chairman of the O. Palladin Institute of Biochemistry of the National Academy of Sciences of Ukraine.
Scientific career
Komisarenko received an M.D. degree in 1966 from the Kyiv Medical Institute and a Ph.D. in biochemistry from Kyiv University in 1970. He worked at the Palladin Institute of Biochemistry, Ukrainian Academy of Sciences from 1969 to 1992, becoming its director in 1992. He became an academician of the Ukrainian National Academy of Sciences in 1991, and of the Ukrainian Academy of Medical Sciences in 1993.
His main scientific interests are in immunochemical analysis of peptide and protein antigenic structure. He was the founder of molecular immunology studies in Ukraine; his team was the first in the former Soviet Union to implement immunoenzyme methods, monoclonal antibody technique, and flow cytofluorimetry in research.
He was the head of the Ukrainian Scientific Immunology Program; under his guidance it was found that low-dose radiation from Chernobyl fall-out decreased the number and activity of natural killer cells in humans. This immune suppression he named “Chernobyl AIDS”.
He is president of the Ukrainian Biochemistry Society, president and a founder of the Ukrainian International Institute of Peac
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https://en.wikipedia.org/wiki/Denjoy%20integral
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The Denjoy integral in mathematics can refer to two closely related integrals connected to the work of Arnaud Denjoy:
the narrow Denjoy integral, or just Denjoy integral, also known as Henstock–Kurzweil integral,
the (more general) wide Denjoy integral, or Khinchin integral.
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https://en.wikipedia.org/wiki/Rivett%2C%20Australian%20Capital%20Territory
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Rivett () (postcode: 2611) is a residential suburb of Canberra, Australian Capital Territory, Australia, established in the late 1960s. At the , Rivett had a population of 3,354. It is situated on the western edge of the Weston Creek district.
Rivett takes its name from Sir David Rivett, the professor of Chemistry at the University of Melbourne (1924–1927), deputy chairman and chief executive officer of the Council for Scientific and Industrial Research (CSIR, 1927–1946), chairman of the council of CSIRO (1946–1949), and president of Australian and New Zealand Association for the Advancement of Science (1937–1939).
Streets in Rivett are named after Australian flora.
Several homes in Rivett were burnt, and many residents evacuated during the 2003 Canberra bushfires.
Suburb amenities
Shops
The Rivett local shopping centre is located at Rivett Place (off Bangalay Crescent). The centre contains a supermarket, newsagency, hairdresser, a cafe, therapeutic masseuse and bakery.
Educational institutions
Rivett Preschool is located in Nealie Place off Bangalay Crescent. There are no non-government schools or colleges in Rivett.
Places of worship
The Reformed Church of Canberra of the Christian Reformed Churches of Australia is located behind the shopping centre off Rivett Place.
Health facilities
The Burrangiri Respite Services day care for elderly people near the shopping centre.
Transport
ACTION buses run regular services to Rivett. Route 64 services most of Rivett and links
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https://en.wikipedia.org/wiki/Abstract%20polytope
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In mathematics, an abstract polytope is an algebraic partially ordered set which captures the dyadic property of a traditional polytope without specifying purely geometric properties such as points and lines.
A geometric polytope is said to be a realization of an abstract polytope in some real N-dimensional space, typically Euclidean. This abstract definition allows more general combinatorial structures than traditional definitions of a polytope, thus allowing new objects that have no counterpart in traditional theory.
Introductory concepts
Traditional versus abstract polytopes
In Euclidean geometry, two shapes that are not similar can nonetheless share a common structure. For example, a square and a trapezoid both comprise an alternating chain of four vertices and four sides, which makes them quadrilaterals. They are said to be isomorphic or “structure preserving”.
This common structure may be represented in an underlying abstract polytope, a purely algebraic partially ordered set which captures the pattern of connections (or incidences) between the various structural elements. The measurable properties of traditional polytopes such as angles, edge-lengths, skewness, straightness and convexity have no meaning for an abstract polytope.
What is true for traditional polytopes (also called classical or geometric polytopes) may not be so for abstract ones, and vice versa. For example, a traditional polytope is regular if all its facets and vertex figures are regular, but t
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https://en.wikipedia.org/wiki/Idleness
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Idleness is a lack of motion or energy. In describing a person, idle suggests having no labor: "idly passing the day".
In physics, an idle machine exerts no transfer of energy. When a vehicle is not in motion, an idling engine does no useful thermodynamic work. In computing, an idle processor or network circuit is not being used by any program, application, or message.
Cultural norms
Typically, when one describes a machine as idle, it is an objective statement regarding its current state. However, when used to describe a person, idle typically carries a negative connotation, with the assumption that the person is wasting their time by doing nothing of value.
Such a view is reflected in the proverb "an idle mind is the devil's workshop". Also, the popular phrase "killing time" refers to idleness and can be defined as spending time doing nothing in particular in order that time seems to pass more quickly. These interpretations of idleness are not universal – they are more typically associated with Western cultures. Idleness was considered a disorderly offence in England punishable as a summary offense.
Involuntary enforced idleness is the punishment used for lazy or slacking workers in zero-hour contracts. Paid time off, which was introduced in the 20th century as a trade unionist reform, is now absent from an increasing number of job arrangements both as a money-saving mechanism and so that only work pays and thus reinforcing the stigma against idleness and enabling nat
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https://en.wikipedia.org/wiki/Least%20fixed%20point
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In order theory, a branch of mathematics, the least fixed point (lfp or LFP, sometimes also smallest fixed point) of a function from a partially ordered set to itself is the fixed point which is less than each other fixed point, according to the order of the poset. A function need not have a least fixed point, but if it does then the least fixed point is unique.
Examples
With the usual order on the real numbers, the least fixed point of the real function f(x) = x2 is x = 0 (since the only other fixed point is 1 and 0 < 1). In contrast, f(x) = x + 1 has no fixed points at all, so has no least one, and f(x) = x has infinitely many fixed points, but has no least one.
Let be a directed graph and be a vertex. The set of vertices accessible from can be defined as the least fixed-point of the function , defined as
The set of vertices which are co-accessible from is defined by a similar least fix-point. The strongly connected component of is the intersection of those two least fixed-points.
Let be a context-free grammar. The set of symbols which produces the empty string can be obtained as the least fixed-point of the function , defined as , where denotes the power set of .
Applications
Many fixed-point theorems yield algorithms for locating the least fixed point. Least fixed points often have desirable properties that arbitrary fixed points do not.
Denotational semantics
In computer science, the denotational semantics approach uses least fixed points to obtain from
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https://en.wikipedia.org/wiki/Diomidis%20Spinellis
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Diomidis D. Spinellis (; 2 February 1967, Athens) is a Greek computer science academic and author of the books Code Reading, Code Quality, Beautiful Architecture (co-author) and Effective Debugging.
Education
Spinellis holds a Master of Engineering degree in Software Engineering and a Ph.D. in Computer Science both from Imperial College London. His PhD was supervised by Susan Eisenbach and Sophia Drossopoulou.
Career and research
He is a professor at the Department of Management Science and Technology at the Athens University of Economics and Business, and a member of the IEEE Software editorial board, contributing the Tools of the Trade column. Since 2014, he is also editor-in-chief of IEEE Software. Spinellis is a four-time winner of the International Obfuscated C Code Contest in 1988, 1990, 1991 and 1995.
He is also a committer in the FreeBSD project, and author of a number of popular free or open-source systems: the UMLGraph declarative UML diagram generator, the bib2xhtml BibTeX to XHTML converter, the outwit Microsoft Windows data with command line programs integration tool suite, the CScout source code analyzer and refactoring browser, the socketpipe fast inter-process communication plumbing utility and directed graph shell the directed graph Unix shell for big data and stream processing pipelines.
In 2008, together with a collaborator, Spinellis claimed that "red links" (a Wikipedia slang for wikilinks that lead to non-existing pages) is what drives Wikipedia grow
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https://en.wikipedia.org/wiki/Syngnathidae
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The Syngnathidae is a family of fish which includes seahorses, pipefishes, and seadragons (Phycodurus and Phyllopteryx). The name is derived from (), meaning "together", and (), meaning "jaw". The fused jaw is one of the traits that the entire family have in common.
Description and biology
Syngnathids are found in temperate and tropical seas across the world. Most species inhabit shallow, coastal waters, but a few are known from the open ocean, especially in association with sargassum mats. They are characterised by their elongated snouts, fused jaws, the absence of pelvic fins, and by thick plates of bony armour covering their bodies. The armour gives them a rigid body, so they swim by rapidly fanning their fins. As a result, they are relatively slow compared with other fish but are able to control their movements with great precision, including hovering in place for extended periods.
Uniquely, after syngnathid females lay their eggs, the male then fertilizes and carries the eggs during incubation, using one of several methods. Male seahorses have a specialized ventral brood pouch to carry the embryos, male sea dragons attach the eggs to their tails, and male pipefish may do either, depending on their species. The most fundamental difference between the different lineages of the family Syngnathidae is the location of male brood pouch. The two locations are on the tail (Urophori) and on the abdomen (Gastrophori). There is also variation in Syngnathid pouch complexity with
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https://en.wikipedia.org/wiki/James%20Hartle
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James Burkett Hartle (August 17, 1939 – May 17, 2023) was an American theoretical physicist. He joined the faculty of the University of California, Santa Barbara in 1966, and was a member of the external faculty of the Santa Fe Institute. Hartle is known for his work in general relativity, astrophysics, and interpretation of quantum mechanics.
Early life
Hartle was born on August 17, 1939, in Baltimore to Anna Elizabeth Burkett and Charles James Hartle. He began as an engineering major upon entering Princeton, but switched to physics due to the influence of John Wheeler.
Hartle completed his AB at Princeton University in 1960 and his Ph.D. in particle physics under Murray Gell-Mann in 1964.
Work
In collaboration with Gell-Mann and others, Hartle developed an alternative to the standard Copenhagen interpretation, more general and appropriate to quantum cosmology, based on consistent histories.
With Dieter Brill in 1964, he discovered the Brill–Hartle geon, an approximate solution realizing Wheeler's suggestion of a hypothetical phenomenon in which a gravitational wave packet is confined to a compact region of spacetime by the gravitational attraction of its own field energy.
With Kip Thorne, Hartle derived from general relativity the laws of motion and precession of black holes and other relativistic bodies, including the influence of the coupling of their multipole moments to the spacetime curvature of nearby objects, as well as writing down the Hartle–Thorne metric, an
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https://en.wikipedia.org/wiki/Quantum%20cosmology
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Quantum cosmology is the attempt in theoretical physics to develop a quantum theory of the universe. This approach attempts to answer open questions of classical physical cosmology, particularly those related to the first phases of the universe.
Classical cosmology is based on Albert Einstein's general theory of relativity (GTR or simply GR) which describes the evolution of the universe very well, as long as you do not approach the Big Bang. It is the gravitational singularity and the Planck time where relativity theory fails to provide what must be demanded of a final theory of space and time. Therefore, a theory is needed that integrates relativity theory and quantum theory. Such an approach is attempted for instance with loop quantum cosmology, loop quantum gravity, string theory and causal set theory.
In quantum cosmology, the universe is treated as a wave function instead of classical spacetime.
See also
String cosmology
Brane cosmology
Loop quantum cosmology
Top-down cosmology
Non-standard cosmology
Loop quantum gravity
Canonical quantum gravity
Dark energy
Minisuperspace
Hamilton–Jacobi–Einstein equation
Theory of everything
References
Notes
External links
A Layman's Explanation of Quantum Cosmology
Lectures on Quantum Cosmology by J.J. Halliwell
Quantum gravity
Physical cosmology
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https://en.wikipedia.org/wiki/Roland%20Omn%C3%A8s
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Roland Omnès (born 18 February 1931) is the author of several books which aim to give non-scientists the information required to understand quantum mechanics from an everyday standpoint.
Biography
Omnès is currently Professor Emeritus of Theoretical Physics in the Faculté des Sciences at Orsay, at the Université Paris-Sud XI. He has been instrumental in developing consistent histories and quantum decoherence approaches in quantum mechanics. In 1959 he received the Paul-Langevin Prize.
Philosophical work
In his philosophical work (especially in Quantum Philosophy), Omnès argues that:
"Until modern times, intuitive, rational thought was sufficient to describe the world; mathematics remained an adjunct, simply helping to make our intuitive descriptions more precise."
"In the late 19th and early 20th centuries, we arrived at a Fracture between common sense and our best descriptions of reality. Our formal description became the truest picture (most consistent with how things are, experimentally) and common sense was left behind. Our best descriptions of reality are now incomprehensible to common sense alone, and our intuitions as to how things are, are often negated by experiment and theory."
"However it is, finally, possible to recover common sense from our formal, mathematical description of reality. We can now demonstrate that the laws of classical logic, classical probability and classical dynamics (of common sense, in fact) apply at the macroscopic level, even in a w
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https://en.wikipedia.org/wiki/Richard%20Schwartz%20%28mathematician%29
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Richard Evan Schwartz (born August 11, 1966) is an American mathematician notable for his contributions to geometric group theory and to an area of mathematics known as billiards. Geometric group theory is a relatively new area of mathematics beginning around the late 1980s which explores finitely generated groups, and seeks connections between their algebraic properties and the geometric spaces on which these groups act. He has worked on what mathematicians refer to as billiards, which are dynamical systems based on a convex shape in a plane. He has explored geometric iterations involving polygons, and he has been credited for developing the mathematical concept known as the pentagram map. In addition, he is a bestselling author of a mathematics picture book for young children. His published work usually appears under the name Richard Evan Schwartz. In 2018 he is a professor of mathematics at Brown University.
Career
Schwartz was born in Los Angeles on August 11, 1966. He attended John F. Kennedy High School in Los Angeles from 1981 to 1984, then earned a B. S. in mathematics from U.C.L.A. in 1987, and then a Ph. D. in mathematics from Princeton University in 1991 under the supervision of William Thurston. He taught at the University of Maryland. He is currently the Chancellor's Professor of Mathematics at Brown University. He lives with his wife and two daughters in Barrington, Rhode Island.
Schwartz is credited by other mathematicians for introducing the concept of the p
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https://en.wikipedia.org/wiki/Hagen%20Kleinert
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Hagen Kleinert (born 15 June 1941) is professor of theoretical physics at the Free University of Berlin, Germany (since 1968),
Honorary Doctor at the
West University of Timișoara, and
at the
Kyrgyz-Russian Slavic University
in Bishkek. He is also
Honorary Member of the
Russian Academy of Creative Endeavors. For his contributions to particle and solid-state physics he was awarded the Max Born Prize 2008 with Medal.
His contribution to the memorial volume celebrating the 100th birthday of Lev Davidovich Landau earned him the Majorana Prize 2008 with Medal. He is married to Dr. Annemarie Kleinert since 1974 with whom he has a son Michael Kleinert.
Publications
Kleinert has written ~420 papers on mathematical physics and the physics of elementary particles, nuclei, solid state systems, liquid crystals, biomembranes, microemulsions, polymers, and the theory of financial markets. He has written several books on theoretical physics, the most notable of which, Path Integrals in Quantum Mechanics, Statistics, Polymer Physics, and Financial Markets, has been published in five editions since 1990 and has received enthusiastic reviews.
Education
He studied physics at the Leibniz University Hannover between 1960 and 1963, and at several American universities including Georgia Institute of Technology, where he learned general relativity as a graduate student from George Gamow, one of the fathers of the Big Bang theory.
Kleinert earned his doctorate in 1967 at the University of Colorado,
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https://en.wikipedia.org/wiki/CPV
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CPV may refer to:
In mathematics, science and technology
Viruses
Canine parvovirus
Cricket paralysis virus
Cryptosporidium parvum virus, a dsRNA virus of the single-celled causative agent of Cryptosporidiosis
Other uses in mathematics, science and technology
Cauchy principal value, a method for assigning values to certain improper integrals in mathematics
Composite Pressure Vessel, often gas cylinders made of composite materials
Concentrator photovoltaics, a solar power technology
Continued process verification, ongoing monitoring of all aspects of the production cycle
CP-violation, a phenomenon in physics
Transport
Air Corporate (ICAO code CPV), an Italian airline
Compassvale LRT station (LRT station abbreviation CPV), a Light Rail Transit station in Sengkang, Singapore
Other uses
CPV-TV, a defunct UK media company
Cape Verde, ISO 3166-1 alpha-3 country code
Child-to-parent violence, parental abuse by children
Common Procurement Vocabulary, a European Union system of codes used by member states in public procurement procedures
Communist Party of Vietnam
Cost per view, in video online advertising
See also
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https://en.wikipedia.org/wiki/Paul%20Ernest
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Paul Ernest is a contributor to the social constructivist philosophy of mathematics.
Life
Paul Ernest is currently emeritus professor of the philosophy of mathematics education at Exeter University, UK. He is best known for his work on philosophical aspects of mathematics education and his contributions to developing a social constructivist philosophy of mathematics. He is currently working on questions about ethics in mathematics.
References
Ernest, Paul; Social Constructivism as a Philosophy of Mathematics; Albany, New York: State University of New York Press, (1998)
Ernest, Paul; The Philosophy of Mathematics Education; London: RoutledgeFalmer, (1991)
External links
Paul Ernest's page at Philosophy of Mathematics Education Journal, the journal that he edits at School of Education, University of Exeter-publications, CV etc.
Paul Ernest's page at Amazon.com
Living people
Scientists from New York City
English mathematicians
20th-century American mathematicians
21st-century American mathematicians
Philosophers of mathematics
Mathematicians from New York (state)
Year of birth missing (living people)
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https://en.wikipedia.org/wiki/Bohm
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Bohm may refer to:
Physics
David Bohm, 20th century theoretical physicist who lent his name to several concepts in physics:
Aharonov–Bohm effect of electromagnetic potential on a particle
Bohm sheath criterion for a Debye sheath plasma layer
Bohm diffusion of plasma in a magnetic field
Bohm interpretation of the configuration of particles
De Broglie–Bohm theory of quantum mechanics, also known as pilot wave theory
Other
Bohm (surname)
Bohm Dialogue, free-flowing group conversation
See also
Böhme (disambiguation)
Böhm
Boehm
Baum
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https://en.wikipedia.org/wiki/Seymour%20Benzer
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Seymour Benzer (October 15, 1921 – November 30, 2007) was an American physicist, molecular biologist and behavioral geneticist. His career began during the molecular biology revolution of the 1950s, and he eventually rose to prominence in the fields of molecular and behavioral genetics. He led a productive genetics research lab both at Purdue University and as the James G. Boswell Professor of Neuroscience, emeritus, at the California Institute of Technology.
Biography
Early life and education
Benzer was born in the South Bronx to Meir Benzer and Eva Naidorf, both Jews from Poland. He had two older sisters, and his parents favored him as the only boy. One of Benzer's earliest scientific experiences was dissecting frogs he had caught as a boy. In an interview at Caltech, Benzer also remembered receiving a microscope for his 13th birthday, “and that opened up the whole world.” The book Arrowsmith by Sinclair Lewis heavily influenced the young Benzer, and he even imitated the handwriting of Max Gottlieb, a scientist character in the novel. Benzer graduated from New Utrecht High School at 15 years old.
In 1938 he enrolled at Brooklyn College where he majored in physics. Benzer then moved on to Purdue University to earn his Ph.D. in solid state physics. While there he was recruited for a secret military project to develop improved radar. He performed research that led to the development of stable germanium rectifiers and discovered a germanium crystal able to be used at high vo
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https://en.wikipedia.org/wiki/Budker%20Institute%20of%20Nuclear%20Physics
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The Budker Institute of Nuclear Physics (BINP) is one of the major centres of advanced study of nuclear physics in Russia. It is located in the Siberian town Akademgorodok, on Academician Lavrentiev Avenue. The institute was founded by Gersh Budker in 1959. Following his death in 1977, the institute was renamed in honour of Budker.
Despite its name, the centre was not involved either with military atomic science or nuclear reactors instead, its concentration was on high-energy physics (particularly plasma physics) and particle physics. In 1961 the institute began building VEP-1, the first particle accelerator in the Soviet Union which collided two beams of particles, just a few months after the ADA collider became operational at the Frascati National Laboratories in Italy in February 1961. The BINP employs over 3000 people, and hosts research groups and facilities.
Active facilities
VEPP-4 – e+e− collider for the energy range 2Ebeam up to 12 GeV
KEDR – detector for particle physics at VEPP-4
ROKK-1 – facility for experiments with high energy polarized gamma-ray beams at VEPP-4
VEPP-2000 – e+e− collider for the energy range 2Ebeam=0.4-2.0 GeV
SND - Spherical Neutral Detector for particle physics experiments at VEPP-2000
CMD-3 – Creogenic Magnetic Detector for particle physics experiments at VEPP-2000
Electron cooling experiments
Plasma physics experiments
GOL3 – long open plasma trap
GDL - gas-dynamic plasma trap
Siberian Synchrotron Radiation Centre
NovoFEL – Novosibirsk Fr
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https://en.wikipedia.org/wiki/%27t%20Hooft%E2%80%93Polyakov%20monopole
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In theoretical physics, the t Hooft–Polyakov monopole is a topological soliton similar to the Dirac monopole but without the Dirac string. It arises in the case of a Yang–Mills theory with a gauge group G, coupled to a Higgs field which spontaneously breaks it down to a smaller group H via the Higgs mechanism. It was first found independently by Gerard 't Hooft and Alexander Polyakov.
Unlike the Dirac monopole, the 't Hooft–Polyakov monopole is a smooth solution with a finite total energy. The solution is localized around . Very far from the origin, the gauge group G is broken to H, and the 't Hooft–Polyakov monopole reduces to the Dirac monopole.
However, at the origin itself, the G gauge symmetry is unbroken and the solution is non-singular also near the origin. The Higgs field
is proportional to
where the adjoint indices are identified with the three-dimensional spatial indices. The gauge field at infinity is such that the Higgs field's dependence on the angular directions is pure gauge. The precise configuration for the Higgs field and the gauge field near the origin is such that it satisfies the full Yang–Mills–Higgs equations of motion.
Mathematical details
Suppose the vacuum is the vacuum manifold Σ. Then, for finite energies, as we move along each direction towards spatial infinity, the state along the path approaches a point on the vacuum manifold Σ. Otherwise, we would not have a finite energy. In topologically trivial 3 + 1 dimensions, this means spatial i
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https://en.wikipedia.org/wiki/Nitride
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In chemistry, a nitride is an inorganic compound of nitrogen. The "nitride" anion, N3- ion, is very elusive but compounds of nitride are numerous, although rarely naturally occurring. Some nitrides have a found applications, such as wear-resistant coatings (e.g., titanium nitride, TiN), hard ceramic materials (e.g., silicon nitride, Si3N4), and semiconductors (e.g., gallium nitride, GaN). The development of GaN-based light emitting diodes was recognized by the 2014 Nobel Prize in Physics. Metal nitrido complexes are also common.
Synthesis of inorganic metal nitrides is challenging because nitrogen gas (N2) is not very reactive at low temperatures, but it becomes more reactive at higher temperatures. Therefore, a balance must be achieved between the low reactivity of nitrogen gas at low temperatures and the entropy driven formation of N2 at high temperatures. However, synthetic methods for nitrides are growing more sophisticated and the materials are of increasing technological relevance.
Uses of nitrides
Like carbides, nitrides are often refractory materials owing to their high lattice energy, which reflects the strong bonding of "N3−" to with metal cation(s). Thus, cubic boron nitride, titanium nitride, and silicon nitride are used as cutting materials and hard coatings. Hexagonal boron nitride, which adopts a layered structure, is a useful high-temperature lubricant akin to molybdenum disulfide. Nitride compounds often have large band gaps, thus nitrides are usually insu
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https://en.wikipedia.org/wiki/Electrophilic%20addition
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In organic chemistry, an electrophilic addition reaction is an addition reaction where a chemical compound containing a double or triple bond has a π bond broken, with the formation of two new σ bonds.
The driving force for this reaction is the formation of an electrophile X+ that forms a covalent bond with an electron-rich, unsaturated C=C bond. The positive charge on X is transferred to the carbon-carbon bond, forming a carbocation during the formation of the C-X bond.
In the second step of an electrophilic addition, the positively charge on the intermediate combines with an electron-rich species to form the second covalent bond. The second step is the same nucleophilic attack process found in an SN1 reaction. The exact nature of the electrophile and the nature of the positively charged intermediate are not always clear and depend on reactants and reaction conditions.
In all asymmetric addition reactions to carbon, regioselectivity is important and often determined by Markovnikov's rule. Organoborane compounds give anti-Markovnikov additions. Electrophilic attack to an aromatic system results in electrophilic aromatic substitution rather than an addition reaction.
Typical electrophilic additions
Typical electrophilic additions to alkenes with reagents are:
Halogen addition reactions: X2
Hydrohalogenations: HX
Hydration reactions: H2O
Hydrogenations: H2
Oxymercuration reactions: mercuric acetate, water
Hydroboration-oxidation reactions: diborane
the Prins reactio
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https://en.wikipedia.org/wiki/Wolff%E2%80%93Kishner%20reduction
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The Wolff–Kishner reduction is a reaction used in organic chemistry to convert carbonyl functionalities into methylene groups. In the context of complex molecule synthesis, it is most frequently employed to remove a carbonyl group after it has served its synthetic purpose of activating an intermediate in a preceding step. As such, there is no obvious retron for this reaction. The reaction was reported by Nikolai Kischner in 1911 and Ludwig Wolff in 1912.
In general, the reaction mechanism first involves the in situ generation of a hydrazone by condensation of hydrazine with the ketone or aldehyde substrate. Sometimes it is however advantageous to use a pre-formed hydrazone as substrate (see modifications). The rate determining step of the reaction is de-protonation of the hydrazone by an alkoxide base to form a diimide anion by a concerted, solvent mediated protonation/de-protonation step. Collapse of this alkyldiimide with loss of N2 leads to formation of an alkylanion which can be protonated by solvent to give the desired product.
Because the Wolff–Kishner reduction requires highly basic conditions, it is unsuitable for base-sensitive substrates. In some cases, formation of the required hydrazone will not occur at sterically hindered carbonyl groups, preventing the reaction. However, this method can be superior to the related Clemmensen reduction for compounds containing acid-sensitive functional groups such as pyrroles and for high-molecular weight compounds.
History
Th
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https://en.wikipedia.org/wiki/Pseudohalogen
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Pseudohalogens are polyatomic analogues of halogens, whose chemistry, resembling that of the true halogens, allows them to substitute for halogens in several classes of chemical compounds. Pseudohalogens occur in pseudohalogen molecules, inorganic molecules of the general forms Ps–Ps or Ps–X (where Ps is a pseudohalogen group), such as cyanogen; pseudohalide anions, such as cyanide ion; inorganic acids, such as hydrogen cyanide; as ligands in coordination complexes, such as ferricyanide; and as functional groups in organic molecules, such as the nitrile group. Well-known pseudohalogen functional groups include cyanide, cyanate, thiocyanate, and azide.
Common pseudohalogens and their nomenclature
Many pseudohalogens are known by specialized common names according to where they occur in a compound. Well-known ones include (the true halogen chlorine is listed for comparison):
is considered to be a pseudohalogen ion due to its disproportionation reaction with alkali and the ability to form covalent bonds with hydrogen.
Examples of pseudohalogen molecules
Examples of symmetrical pseudohalogen compounds (, where Ps is a pseudohalogen) include cyanogen , thiocyanogen and hydrogen peroxide . Another complex symmetrical pseudohalogen compound is dicobalt octacarbonyl, . This substance can be considered as a dimer of the hypothetical cobalt tetracarbonyl, .
Examples of non-symmetrical pseudohalogen compounds (pseudohalogen halides , where Ps is a pseudohalogen and X is a halogen
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https://en.wikipedia.org/wiki/Institute%20of%20Hydrobiology
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The Institute of Hydrobiology, Chinese Academy of Sciences () is a research institute located in Wuhan, Hubei, China. It was founded in 1950 and specializes in freshwater organisms. It is involved in the study of the finless porpoise and the now extinct baiji dolphin. China Zebrafish Resource Center is housed in the institute campus.
IHB is one of the oldest institutes for aquatic sciences in China, has made contributions to the advancement of aquatic sciences in China and globally.
The Gallery
References
External links
Research institutes of the Chinese Academy of Sciences
Education in Wuhan
1950 establishments in China
Aquaria in China
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https://en.wikipedia.org/wiki/Wiener%20filter
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In signal processing, the Wiener filter is a filter used to produce an estimate of a desired or target random process by linear time-invariant (LTI) filtering of an observed noisy process, assuming known stationary signal and noise spectra, and additive noise. The Wiener filter minimizes the mean square error between the estimated random process and the desired process.
Description
The goal of the Wiener filter is to compute a statistical estimate of an unknown signal using a related signal as an input and filtering that known signal to produce the estimate as an output. For example, the known signal might consist of an unknown signal of interest that has been corrupted by additive noise. The Wiener filter can be used to filter out the noise from the corrupted signal to provide an estimate of the underlying signal of interest. The Wiener filter is based on a statistical approach, and a more statistical account of the theory is given in the minimum mean square error (MMSE) estimator article.
Typical deterministic filters are designed for a desired frequency response. However, the design of the Wiener filter takes a different approach. One is assumed to have knowledge of the spectral properties of the original signal and the noise, and one seeks the linear time-invariant filter whose output would come as close to the original signal as possible. Wiener filters are characterized by the following:
Assumption: signal and (additive) noise are stationary linear stochastic
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https://en.wikipedia.org/wiki/Maximum%20entropy
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Maximum entropy may refer to:
Entropy, a scientific concept as well as a measurable physical property that is most commonly associated with a state of disorder, randomness, or uncertainty.
Physics
Maximum entropy thermodynamics
Maximum entropy spectral estimation
Mathematics and statistics
Principle of maximum entropy
Maximum entropy probability distribution
Maximum entropy classifier, in regression analysis
See also
Second law of thermodynamics, establishes the concept of entropy as a physical property of a thermodynamic system
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https://en.wikipedia.org/wiki/Discrete-time%20Fourier%20transform
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In mathematics, the discrete-time Fourier transform (DTFT), also called the finite Fourier transform, is a form of Fourier analysis that is applicable to a sequence of values.
The DTFT is often used to analyze samples of a continuous function. The term discrete-time refers to the fact that the transform operates on discrete data, often samples whose interval has units of time. From uniformly spaced samples it produces a function of frequency that is a periodic summation of the continuous Fourier transform of the original continuous function. Under certain theoretical conditions, described by the sampling theorem, the original continuous function can be recovered perfectly from the DTFT and thus from the original discrete samples. The DTFT itself is a continuous function of frequency, but discrete samples of it can be readily calculated via the discrete Fourier transform (DFT) (see ), which is by far the most common method of modern Fourier analysis.
Both transforms are invertible. The inverse DTFT is the original sampled data sequence. The inverse DFT is a periodic summation of the original sequence. The fast Fourier transform (FFT) is an algorithm for computing one cycle of the DFT, and its inverse produces one cycle of the inverse DFT.
Definition
The discrete-time Fourier transform of a discrete sequence of real or complex numbers , for all integers , is a Trigonometric series, which produces a periodic function of a frequency variable. When the frequency vari
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https://en.wikipedia.org/wiki/CERN%20Axion%20Solar%20Telescope
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The CERN Axion Solar Telescope (CAST) is an experiment in astroparticle physics to search for axions originating from the Sun. The experiment, sited at CERN in Switzerland, was commissioned in 1999 and came online in 2002 with the first data-taking run starting in May 2003. The successful detection of solar axions would constitute a major discovery in particle physics, and would also open up a brand new window on the astrophysics of the solar core.
CAST is currently the most sensitive axion helioscope.
Theory and operation
If the axions exist, they may be produced in the Sun's core when X-rays scatter off electrons and protons in the presence of strong electric fields. The experimental setup is built around a 9.26 m long decommissioned test magnet for the LHC capable of producing a field of up to . This strong magnetic field is expected to convert solar axions back into X-rays for subsequent detection by X-ray detectors. The telescope observes the Sun for about 1.5 hours at sunrise and another 1.5 hours at sunset each day. The remaining 21 hours, with the instrument pointing away from the Sun, are spent measuring background axion levels.
CAST began operation in 2003 searching for axions up to . In 2005, Helium-4 was added to the magnet, extending sensitivity to masses up to 0.39 eV, then Helium-3 was used during 2008–2011 for masses up to 1.15 eV. CAST then ran with vacuum again searching for axions below 0.02 eV.
As of 2014, CAST has not turned up definitive evidence for
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https://en.wikipedia.org/wiki/Rose%20Bowl%20%28stadium%29
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The Rose Bowl is an outdoor athletic stadium located in Pasadena, California. Opened in October 1922, the stadium is recognized as a National Historic Landmark and a California Historic Civil Engineering landmark. At a modern capacity of an all-seated configuration at 92,542, the Rose Bowl is the 16th-largest stadium in the world, the 11th-largest stadium in the United States, and the 10th-largest NCAA stadium. The stadium is 10 miles (16 km) northeast of downtown Los Angeles.
One of the most famous venues in sporting history, the Rose Bowl is best known as a college football venue, specifically as the host of the annual Rose Bowl Game for which it is named. Since 1982, it has served as the home stadium of the UCLA Bruins football team. Five Super Bowl games, third most of any venue, have been played in the stadium. The Rose Bowl is a noted soccer venue, having hosted the 1994 FIFA World Cup Final, 1999 FIFA Women's World Cup Final, and the 1984 Olympic Soccer Gold Medal Match, as well as numerous CONCACAF and United States Soccer Federation matches.
The stadium and adjacent Brookside Golf and Country Club are owned by the city of Pasadena and managed by the Rose Bowl Operating Company, a non-profit organization whose board is selected by council members of the city of Pasadena. UCLA and the Pasadena Tournament of Roses also have one member on the company board. The Chief Executive Officer and General Manager was Darryl Dunn from 1999 until he retired in June 2022.
History
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https://en.wikipedia.org/wiki/Carlos%20Bustamante%20%28biophysicist%29
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Carlos José Bustamante (born 1951 in Lima, Peru) is a Peruvian-American scientist. He is a member of the National Academy of Sciences.
Biography
Carlos Bustamante is a Howard Hughes Medical Institute (HHMI) investigator, professor of molecular and cell biology, physics, and chemistry at the University of California, Berkeley, and Biophysicist Faculty Scientist at the Lawrence Berkeley National Laboratory.
Bustamante studied medicine at National University of San Marcos before discovering his true interest in biochemistry. He received his BSc from Cayetano Heredia University in Lima, his MSc in biochemistry from National University of San Marcos in Lima, and his PhD in biophysics from UC Berkeley, where he studied with Ignacio Tinoco, Jr. As a postdoctoral fellow at the Lawrence Berkeley National Laboratory, Bustamante studied with Marcos Maestre. Before moving to Berkeley, he was an HHMI investigator at the University of Oregon.
Research focus
Carlos Bustamante uses novel methods of single-molecule visualization, such as scanning force microscopy, to study the structure and function of nucleoprotein assemblies. His laboratory is developing methods of single-molecule manipulation, such as optical tweezers, to characterize the elasticity of DNA, to induce the mechanical unfolding of individual protein molecules, and to investigate the machine-like behavior of molecular motors.
Positions
Research assistant, UC Berkeley (1976–1981)
Postdoctoral fellow, Lawrence Berkeley Labo
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https://en.wikipedia.org/wiki/Zeki%20Sezer
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Mehmet Zeki Sezer (born 12 April 1957) is a Turkish politician and former chairman of the Democratic Left Party (Demokratik Sol Parti, DSP), he was elected in the 6th ordinary party congress in 2004 after the resignation of Bülent Ecevit.
Early years
Sezer was born in 1957 in Eskişehir. He graduated from M. Rüştü Uzel Chemistry Vocational High School and then from the School of Chemical Engineering at Gazi Üniversitesi in Ankara. He completed his 4-month short-term military service in 1983.
Early career
During his high school and university years, Sezer played volleyball for various clubs. He has a special interest in arts. Sezer began his career as a chemistry technician in 1975 in the public service and later worked as a chemical engineer. He worked also in the private sector in the same capacity.
Political career
His political career in the DSP started in 1988. Sezer served as an executive of Çankaya branch of DSP, as deputy-chairman of Ankara branch and became a board member in 1991. He also served twice as the party's secretary-general. Between 2001 and 2004 he was the deputy chairman of DSP. In 2004 party congress succeeded Ecevit. However, in 2009 he lost this post to Masum Türker. In 1999, Sezer was elected as deputy of Ankara to the Parliament and served as a minister of state in the 57th government under the Prime minister Bülent Ecevit
Family life
Sezer is married and has two children.
References
1957 births
Living people
People from Eskişehir
Democratic Lef
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https://en.wikipedia.org/wiki/Jim%20Telfer
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James Telfer (born 17 March 1940) is a Scottish former rugby union coach and player. As a player, he won 21 international caps in the amateur era, also having a career as a headmaster at Hawick High School and Galashiels Academy and Forrester High School as a chemistry teacher. With Sir Ian McGeechan he had success with both the Scotland national team and the British Lions.
Playing career
Telfer played for Melrose RFC and was still a student when he was first selected for international duties. He later worked as a chemistry teacher. His first cap came against France at Murrayfield on 4 January 1964. His last match for Scotland was on 28 February 1970 at Lansdowne Road against Ireland.
Telfer gained twenty one caps for Scotland, and, but for injury, might have gained more. Allan Massie wrote of him:
"Telfer is a man of innate authority. (There's a wealth of quiet reserve and self-knowledge, touched by that form of self-mockery which appears as under-statement, in the way he will describe himself as being a 'dominant personality')"
Telfer played back row for Scotland and for the British Lions in 1966 and 1968. He was impressed and heavily influenced by New Zealand rugby. After a cartilage operation he slowed up. He played 23 games for the British Lions on their 1966 tour to Australia and New Zealand and 11 games on their 1968 tour to South Africa.
Between 1963 and 1967, he played 8 times for the Barbarians, scoring six points.
George Crerar said of him "The great thing ab
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https://en.wikipedia.org/wiki/T.%20C.%20Hsu
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T.C. Hsu (; 17 April 1917 – 9 July 2003), was a Chinese American cell biologist. He was the 13th president of American Society for Cell Biology, and known as the Father of Mammalian Cytogenetics.
Life
Hsu was born Hsu Tao-Chiuh in Shaoxing, Zhejiang, China. He did his undergraduate and postgraduate studies in the College of Agricultural Sciences, Zhejiang University. 1948, he went to USA, and obtained PhD from the University of Texas at Austin in 1951. Hsu worked in the laboratory of Charles Pomerat at the University of Texas Medical Branch during the early 1950s.
Since the turn of the twentieth century, chromosomes prepared on microscope slides formed clumps that made it extremely difficult to distinguish them. Although the preparations made the identification of individual chromosomes difficult, by the 1920s, cytologists consistently reported a diploid number of 48 human chromosomes. In April 1952, Hsu discovered a technique—the hypotonic solution—that separated the clumped chromosomes, thereby allowing him to observe each one individually Even though he now could distinguish human chromosomes to a much greater degree than his predecessors, Hsu still reported a diploid number of 48 human chromosomes (see Figure 14 in his 1952 paper). The correct diploid chromosome number of 46 human chromosomes was first reported three years later by Joe Hin Tjio and Albert Levan
Bryan Sykes describes Hsu and the diploid chromosome number in his book, ADAM'S CURSE .
Hsu was president
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https://en.wikipedia.org/wiki/Criticality
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Criticality may refer to:
Physics terms
Critical phenomena, the collective name associated with the physics of critical points
Critical point (thermodynamics), the end point of a phase equilibrium curve
Quantum critical point, a special class of continuous phase transition that takes place at absolute zero
Nuclear-physics terms
Critical mass, referring to criticality in nuclear physics, when a nuclear reactor's fissionable material can sustain a chain reaction by itself
Criticality (status), a milestone in the commissioning of a nuclear power plant
Criticality accident, an uncontrolled nuclear chain reaction
Nuclear criticality safety, the prevention of nuclear and radiation accidents resulting from an inadvertent, self-sustaining nuclear chain reaction
Prompt critical, an assembly for each nuclear fission event
Other terms
Critical thinking, in education
Criticality index, in risk analysis
Criticality matrix, a representation (often graphical) of failure modes along with their probabilities and severities
Self-organized criticality, a property of (classes of) dynamical systems which have a critical point as an attractor
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https://en.wikipedia.org/wiki/Spallation
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Spallation is a process in which fragments of material (spall) are ejected from a body due to impact or stress. In the context of impact mechanics it describes ejection of material from a target during impact by a projectile. In planetary physics, spallation describes meteoritic impacts on a planetary surface and the effects of stellar winds and cosmic rays on planetary atmospheres and surfaces. In the context of mining or geology, spallation can refer to pieces of rock breaking off a rock face due to the internal stresses in the rock; it commonly occurs on mine shaft walls. In the context of anthropology, spallation is a process used to make stone tools such as arrowheads by knapping. In nuclear physics, spallation is the process in which a heavy nucleus emits numerous nucleons as a result of being hit by a high-energy particle, thus greatly reducing its atomic weight. In industrial processes and bioprocessing the loss of tubing material due to the repeated flexing of the tubing within a peristaltic pump is termed spallation.
In solid mechanics
Spallation can occur when a tensile stress wave propagates through a material and can be observed in flat plate impact tests. It is caused by an internal cavitation due to stresses, which are generated by the interaction of stress waves, exceeding the local tensile strength of materials. A fragment or multiple fragments will be created on the free end of the plate. This fragment known as "spall" acts as a secondary projectile with ve
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https://en.wikipedia.org/wiki/Hydroformylation
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In organic chemistry, hydroformylation, also known as oxo synthesis or oxo process, is an industrial process for the production of aldehydes () from alkenes (). This chemical reaction entails the net addition of a formyl group () and a hydrogen atom to a carbon-carbon double bond. This process has undergone continuous growth since its invention: production capacity reached 6.6 tons in 1995. It is important because aldehydes are easily converted into many secondary products. For example, the resultant aldehydes are hydrogenated to alcohols that are converted to detergents. Hydroformylation is also used in speciality chemicals, relevant to the organic synthesis of fragrances and pharmaceuticals. The development of hydroformylation is one of the premier achievements of 20th-century industrial chemistry.
The process entails treatment of an alkene typically with high pressures (between 10 and 100 atmospheres) of carbon monoxide and hydrogen at temperatures between 40 and 200 °C. In one variation, formaldehyde is used in place of synthesis gas. Transition metal catalysts are required. Invariably, the catalyst dissolves in the reaction medium, i.e. hydroformylation is an example of homogeneous catalysis.
History
The process was discovered by the German chemist Otto Roelen in 1938 in the course of investigations of the Fischer–Tropsch process. Aldehydes and diethylketone were obtained when ethylene was added to an F-T reactor. Through these studies, Roelen discovered the utility of
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https://en.wikipedia.org/wiki/Coulometry
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In analytical electrochemistry, coulometry determines the amount of matter transformed during an electrolysis reaction by measuring the amount of electricity (in coulombs) consumed or produced. It can be used for precision measurements of charge, and the amperes even used to have a coulometric definition. However, today coulometry is mainly used for analytical applications. It is named after Charles-Augustin de Coulomb.
There are two basic categories of coulometric techniques. Potentiostatic coulometry involves holding the electric potential constant during the reaction using a potentiostat. The other, called coulometric titration or amperostatic coulometry, keeps the current (measured in amperes) constant using an amperostat.
Potentiostatic coulometry
Potentiostatic coulometry is a technique most commonly referred to as "bulk electrolysis". The working electrode is kept at a constant potential and the current that flows through the circuit is measured. This constant potential is applied long enough to fully reduce or oxidize all of the electroactive species in a given solution. As the electroactive molecules are consumed, the current also decreases, approaching zero when the conversion is complete. The sample mass, molecular mass, number of electrons in the electrode reaction, and number of electrons passed during the experiment are all related by Faraday's laws. It follows that, if three of the values are known, then the fourth can be calculated.
Bulk electrolysi
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https://en.wikipedia.org/wiki/Supercritical
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Supercritical may refer to:
Physics and technology
Condensed matter physics
Critical temperature, TC, a temperature above which distinct liquid and gas phases do not exist for a given material
Supercritical drying, a process used to remove liquid in a precisely controlled way, similar to freeze drying
Supercritical fluid, a substance at a temperature and pressure above its thermodynamic critical point:
Supercritical carbon dioxide:
Supercritical fluid chromatography, a form of liquid chromatography using supercritical carbon dioxide as the mobile phase
Supercritical water:
Supercritical steam generator, a steam generator operating above the critical point of water, hence having no water–steam separation
Supercritical water oxidation or SCWO, a process that occurs in water at temperatures and pressures above a mixture's thermodynamic critical point
Supercritical water reactor (SCWR), a Generation IV nuclear reactor concept that uses supercritical water as the working fluid
Flows
Supercritical flow, where flow velocity is larger than wave velocity
Supercritical airfoil, an airfoil designed to delay the onset of wave drag in the transonic speed regime
Nuclear physics
Supercritical mass, an amount of fissile material that will undergo a sustained nuclear chain reaction at an increasing rate
Mathematics
Hopf bifurcation, in mathematics, a local bifurcation; when the first Lyapunov coefficient is negative, the bifurcation is called supercritical
Pitchfork bifurca
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https://en.wikipedia.org/wiki/Sturm%27s%20theorem
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In mathematics, the Sturm sequence of a univariate polynomial is a sequence of polynomials associated with and its derivative by a variant of Euclid's algorithm for polynomials. Sturm's theorem expresses the number of distinct real roots of located in an interval in terms of the number of changes of signs of the values of the Sturm sequence at the bounds of the interval. Applied to the interval of all the real numbers, it gives the total number of real roots of .
Whereas the fundamental theorem of algebra readily yields the overall number of complex roots, counted with multiplicity, it does not provide a procedure for calculating them. Sturm's theorem counts the number of distinct real roots and locates them in intervals. By subdividing the intervals containing some roots, it can isolate the roots into arbitrarily small intervals, each containing exactly one root. This yields the oldest real-root isolation algorithm, and arbitrary-precision root-finding algorithm for univariate polynomials.
For computing over the reals, Sturm's theorem is less efficient than other methods based on Descartes' rule of signs. However, it works on every real closed field, and, therefore, remains fundamental for the theoretical study of the computational complexity of decidability and quantifier elimination in the first order theory of real numbers.
The Sturm sequence and Sturm's theorem are named after Jacques Charles François Sturm, who discovered the theorem in 1829.
The theorem
The Stur
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https://en.wikipedia.org/wiki/Decompression
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Decompression has several meanings, some of which are covered by several articles:
Data decompression, the action of reversing data compression
Decompression (physics), the release of pressure and the opposition of physical compression
Decompression (altitude). the reduction of pressure and the related physiological effects due to increase in altitude or other equivalent reduction of ambient pressure below normal atmospheric pressure
Uncontrolled decompression, catastrophic reduction of pressure in accidents involving pressure vessels such as aircraft
Decompression (diving), the reduction in pressure and the process of allowing dissolved inert gases to be eliminated from the tissues during ascent from a dive
Decompression (comics), in comic book storytelling, is the stylistic choice to tell a story mainly by visuals, with few words.
Decompression (novel), a 2012 novel by Juli Zeh
Decompression (surgery), a procedure used to reduce pressure on a compressed structure, such as spinal decompression
Herniated disc decompression, a form of treatment for Spinal disc herniation, employed by chiropractors
"Decompression" (The Outer Limits), an episode of the American television fiction series The Outer Limits
Nerve decompression, a procedure to relieve direct pressure on a nerve
Decompression (novel), a 2012 novel by Juli Zeh
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https://en.wikipedia.org/wiki/Arthur%20Smith%20%28rugby%20union%29
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Arthur Robert Smith (23 January 1933 – 3 February 1975) was a Scotland international rugby union player. He played as a Wing.
Rugby Union career
Amateur career
Originally from Castle Douglas in Kirkcudbrightshire in Scotland, he graduated in mathematics at Glasgow University and then gained a PhD at Gonville and Caius College, Cambridge University. He represented Cambridge in four Varsity Matches from 1954 to 1957 inclusive. It was at Cambridge that he came to flourish as a player.
Smith played for a number of sides including Glasgow University, Cambridge University, London Scottish F C, Gosforth, Ebbw Vale, Edinburgh Wanderers and Barbarians FC (the latter on their famous 1957 Easter tour of Wales, when they beat Cardiff RFC 40–0). One of the clubs that Arthur played for was Ebbw Vale, in Wales, and it is rumoured that having been selected by the British Lions that he played a game for Ebbw Vale under another name because Lions were banned for playing after Easter.
International career
He captained both Scotland and the British Lions. He won 33 caps for Scotland and was never dropped until his retirement in 1962, although he did miss the odd match due to injury. He also became Scotland's captain, which is a rare honour for a winger.
His debut was in 1955, a Dark Age for Scottish rugby, as the national team had just lost seventeen tests in a row. Smith helped to break this losing streak by scoring a try in a 35–10 defeat of Wales at Inverleith, which was probably one o
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https://en.wikipedia.org/wiki/Qualitative%20inorganic%20analysis
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Classical qualitative inorganic analysis is a method of analytical chemistry which seeks to find the elemental composition of inorganic compounds. It is mainly focused on detecting ions in an aqueous solution, therefore materials in other forms may need to be brought to this state before using standard methods. The solution is then treated with various reagents to test for reactions characteristic of certain ions, which may cause color change, precipitation and other visible changes.
Qualitative inorganic analysis is that branch or method of analytical chemistry which seeks to establish the elemental composition of inorganic compounds through various reagents.
Physical appearance of inorganic salts
Detecting cations
According to their properties, cations are usually classified into six groups. Each group has a common reagent which can be used to separate them from the solution. To obtain meaningful results, the separation must be done in the sequence specified below, as some ions of an earlier group may also react with the reagent of a later group, causing ambiguity as to which ions are present. This happens because cationic analysis is based on the solubility products of the ions. As the cation gains its optimum concentration needed for precipitation it precipitates and hence allowing us to detect it. The division and precise details of separating into groups vary slightly from one source to another; given below is one of the commonly used schemes.
1st analytical grou
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https://en.wikipedia.org/wiki/Dublin%20Institute%20for%20Advanced%20Studies
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The Dublin Institute for Advanced Studies (DIAS) () is a statutory independent research institute in Ireland. It was established in 1940 on the initiative of the Taoiseach, Éamon de Valera, in Dublin.
The institute consists of three schools: the School of Theoretical Physics, the School of Cosmic Physics and the School of Celtic Studies. The directors of these schools are, as of 2022, Professor Denjoe O'Connor, Professor Tom Ray and Professor Ruairí Ó hUiginn. The institute, under its governing act, is empowered to "train students in methods of advanced research" but does not itself award degrees; graduate students working under the supervision of Institute researchers can, with the agreement of the governing board of the appropriate school, be registered for a higher degree in any university worldwide.
Following a comprehensive review of the higher education sector and its institutions, conducted by the Higher Education Authority for the Minister for Education and Skills in 2013, DIAS was approved to remain an independent institute carrying out fundamental research. It appointed a new CEO, Dr Eucharia Meehan, formerly director of the Irish Research Council, in the summer of 2017.
History
Context
After becoming Taoiseach in 1937, Éamon de Valera investigated the possibility of setting up an institute of higher learning. De Valera was aware of the decline of the Dunsink Observatory, where Sir William Rowan Hamilton and others had held the position of Royal Astronomer of Ir
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https://en.wikipedia.org/wiki/Free-radical%20halogenation
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In organic chemistry, free-radical halogenation is a type of halogenation. This chemical reaction is typical of alkanes and alkyl-substituted aromatics under application of UV light. The reaction is used for the industrial synthesis of chloroform (CHCl3), dichloromethane (CH2Cl2), and hexachlorobutadiene. It proceeds by a free-radical chain mechanism.
General mechanism
The chain mechanism is as follows, using the chlorination of methane as a usual example:
1. Initiation: Splitting or homolysis of a chlorine molecule to form two chlorine atoms, initiated by ultraviolet radiation . A chlorine atom has an unpaired electron and acts as a free radical.
2. Chain propagation (two steps): a hydrogen atom is pulled off from methane leaving a primary methyl radical. The methyl radical then pulls a Cl• from Cl2.
This results in the desired product plus another chlorine radical. This radical will then go on to take part in another propagation reaction causing a chain reaction. If there is sufficient chlorine, other products such as CH2Cl2 may be formed.
3. Chain termination: recombination of two free radicals:
The last possibility in the termination step will result in an impurity in the final mixture; notably this results in an organic molecule with a longer carbon chain than the reactants.
The net reaction is:
The rate law for this process is k[CH4][Cl2]. This can be shown using the steady-state approximation.
In the case of methane or ethane, all the hydrogen atoms are equival
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https://en.wikipedia.org/wiki/M-325
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In the history of cryptography, M-325, also known as SIGFOY, was an American rotor machine designed by William F. Friedman and built in 1944. Between 1944 and 1946, more than 1,100 machines were deployed within the United States Foreign Service. Its use was discontinued in 1946 because of faults in operation. Friedman applied for a patent on the M-325 on 11 August 1944; it was and was granted on 17 March 1959 (US patent #2,877,565).
Like the Enigma, the M-325 contains three intermediate rotors and a reflecting rotor.
See also
Hebern rotor machine
SIGABA
References
Further reading
Louis Kruh, Converter M-325(T), Cryptologia 1, 1977, pp143–149.
External links
Operating and Keying Instructions for Converter M-325(T) Headquarters, Army Security Agency, July 1948, scanned and transcribed by Bob Lord.
Friedman M-325 — information and photographs.
Rotor machines
Cryptographic hardware
World War II American electronics
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https://en.wikipedia.org/wiki/National%20Institute%20of%20Engineering
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The National Institute of Engineering (NIE) is a private engineering college located in Mysore, Karnataka, India. It was established in 1946 and granted autonomy in 2007 from Visvesvaraya Technological University.
History
NIE was started in 1946 with diploma programs in Civil Engineering in a room under a thatched roof in Lakshmipuram under leadership of kushagra. The first batch consisted of 86 students. Later, the classes were held in a shed in the nearby Sharada Vilas High School campus, in Mysore. S. Ramaswamy, D. V. Narasimha Rao and T. Ramarao ("Tunnel" Ramarao), the founders, established NIE by 1950 with its own class rooms and workshops on a campus.
NIE started AMIE courses in Civil Engineering for intermediate-passed students in 1948. The students were permitted to change over to the regular degree course leading to B.E. degree in Civil Engineering of the University of Mysore. Thus, NIE became the second engineering college in the state of Karnataka and the first in Mysore. The first batch of students in Civil Engineering graduated in 1953.
In 1956, NIE was recognised for development during the second and subsequent five-year plans by the state and the Union governments. In 1958-59, NIE got private-aided institution status under grant-in-aid code of the Karnataka government.
A Golden Jubilee Complex was completed in 1996 on a plot opposite the main building in part of the golden jubilee celebrations. In 2004, the college received World Bank aid under the TEQIP p
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https://en.wikipedia.org/wiki/Fhourstones
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In computer science, Fhourstones is an integer benchmark that efficiently solves positions in the game of Connect-4. It was written by John Tromp in 1996-2008, and is incorporated into the Phoronix Test Suite. The measurements are reported as the number of game positions searched per second.
Available in both ANSI-C and Java, it is quite portable and compact (under 500 lines of source), and uses 50Mb of memory.
The benchmark involves (after warming up on three easier positions) solving the entire game, which takes about ten minutes on contemporary PCs, scoring between 1000 and 12,000 kpos/sec. It has been described as more realistic than some other benchmarks.
Fhourstones was named as a pun on Dhrystone (itself a pun on Whetstone), as "dhry" sounds the same as "drei", German for "three": fhourstones is an increment on dhrystones.
References
External links
Fhourstones homepage
Benchmarks (computing)
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https://en.wikipedia.org/wiki/Sheaf
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Sheaf may refer to:
Sheaf (agriculture), a bundle of harvested cereal stems
Sheaf (mathematics), a mathematical tool
Sheaf toss, a Scottish sport
River Sheaf, a tributary of River Don in England
The Sheaf, a student-run newspaper serving the University of Saskatchewan
Aluma, a settlement in Israel whose name translates as Sheaf
See also
Sceafa, a king of English legend
Sheath (disambiguation)
Sheave, a wheel or roller with a groove along its edge for holding a belt, rope or cable
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https://en.wikipedia.org/wiki/Triflate
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In organic chemistry, triflate (systematic name: trifluoromethanesulfonate), is a functional group with the formula and structure . The triflate group is often represented by , as opposed to −Tf, which is the triflyl group, . For example, n-butyl triflate can be written as .
The corresponding triflate anion, , is an extremely stable polyatomic ion; this comes from the fact that triflic acid () is a superacid; i.e. it is more acidic than pure sulfuric acid, already one of the strongest acids known.
Applications
A triflate group is an excellent leaving group used in certain organic reactions such as nucleophilic substitution, Suzuki couplings and Heck reactions. Since alkyl triflates are extremely reactive in SN2 reactions, they must be stored in conditions free of nucleophiles (such as water). The anion owes its stability to resonance stabilization which causes the negative charge to be spread symmetrically over the three oxygen atoms. An additional stabilization is achieved by the trifluoromethyl group, which acts as a strong electron-withdrawing group using the sulfur atom as a bridge.
Triflates have also been applied as ligands for group 11 and 13 metals along with lanthanides.
Lithium triflates are used in some lithium ion batteries as a component of the electrolyte.
A mild triflating reagent is phenyl triflimide or N,N-bis(trifluoromethanesulfonyl)aniline, where the by-product is [CF3SO2N−Ph]−.
Triflate salts
Triflate salts are thermally very stable with melting p
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https://en.wikipedia.org/wiki/Heck%20reaction
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The Heck reaction (also called the Mizoroki–Heck reaction) is the chemical reaction of an unsaturated halide (or triflate) with an alkene in the presence of a base and a palladium catalyst to form a substituted alkene. It is named after Tsutomu Mizoroki and Richard F. Heck. Heck was awarded the 2010 Nobel Prize in Chemistry, which he shared with Ei-ichi Negishi and Akira Suzuki, for the discovery and development of this reaction. This reaction was the first example of a carbon-carbon bond-forming reaction that followed a Pd(0)/Pd(II) catalytic cycle, the same catalytic cycle that is seen in other Pd(0)-catalyzed cross-coupling reactions. The Heck reaction is a way to substitute alkenes.
History
The original reaction by Tsutomu Mizoroki (1971) describes the coupling between iodobenzene and styrene in methanol to form stilbene at 120 °C (autoclave) with potassium acetate base and palladium chloride catalysis. This work was an extension of earlier work by Fujiwara (1967) on the Pd(II)-mediated coupling of arenes (Ar–H) and alkenes and earlier work by Heck (1969) on the coupling of arylmercuric halides (ArHgCl) with alkenes using a stoichiometric amount of a palladium(II) species.
In 1972 Heck acknowledged the Mizoroki publication and detailed independently discovered work. Heck's reaction conditions differ in terms of the catalyst (palladium acetate), catalyst loading (0.01 eq.), base (hindered amine), and absence of solvent.
In 1974 Heck showed that phosphine ligands facili
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https://en.wikipedia.org/wiki/Suzuki%20reaction
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The Suzuki reaction is an organic reaction, classified as a cross-coupling reaction, where the coupling partners are a boronic acid and an organohalide and the catalyst is a palladium(0) complex. It was first published in 1979 by Akira Suzuki, and he shared the 2010 Nobel Prize in Chemistry with Richard F. Heck and Ei-ichi Negishi for their contribution to the discovery and development of palladium-catalyzed cross-couplings in organic synthesis. This reaction is also known as the Suzuki–Miyaura reaction or simply as the Suzuki coupling. It is widely used to synthesize polyolefins, styrenes, and substituted biphenyls. Several reviews have been published describing advancements and the development of the Suzuki reaction. The general scheme for the Suzuki reaction is shown below, where a carbon-carbon single bond is formed by coupling a halide (R1-X) with an organoboron species (R2-BY2) using a palladium catalyst and a base. The organoboron species is usually synthesized by hydroboration or carboboration, allowing for rapid generation of molecular complexity.
Reaction mechanism
The mechanism of the Suzuki reaction is best viewed from the perspective of the palladium catalyst. The catalytic cycle is initiated by the formation of an active Pd0 catalytic species, A. This participates in the oxidative addition of palladium to the halide reagent 1 to form the organopalladium intermediate B. Reaction (metathesis) with base gives intermediate C, which via transmetalation with the bor
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https://en.wikipedia.org/wiki/Archer%20Martin
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Archer John Porter Martin (1 March 1910 – 28 July 2002) was a British chemist who shared the 1952 Nobel Prize in Chemistry for the invention of partition chromatography with Richard Synge.
Early life
Martin's father was a GP. Martin was educated at Bedford School, and Peterhouse, Cambridge.
Career
Working first in the Physical Chemistry Laboratory, he moved to the Dunn Nutritional Laboratory, and in 1938 moved to Wool Industries Research Institution in Leeds. He was head of the biochemistry division of Boots Pure Drug Company from 1946 to 1948, when he joined the Medical Research Council. There, he was appointed head of the physical chemistry division of the National Institute for Medical Research in 1952, and was chemical consultant from 1956 to 1959.
He specialised in biochemistry, in some aspects of vitamins E and B2, and in techniques that laid the foundation for several new types of chromatography. He developed partition chromatography whilst working on the separation of amino acids, and later developed gas-liquid chromatography. Amongst many honours, he received his Nobel Prize in 1952.
After his retirement from the University of Sussex, he was visiting professor at both the University of Houston in Texas and the EPFL (École Polytechnique Fédérale de Lausanne) in Switzerland.
He published far fewer papers than the typical Nobel winners—only 70 in all—but his ninth paper contained the work that would eventually win him the Nobel Prize. The University of Houston dr
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https://en.wikipedia.org/wiki/Hull%E2%80%93White%20model
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In financial mathematics, the Hull–White model is a model of future interest rates. In its most generic formulation, it belongs to the class of no-arbitrage models that are able to fit today's term structure of interest rates. It is relatively straightforward to translate the mathematical description of the evolution of future interest rates onto a tree or lattice and so interest rate derivatives such as bermudan swaptions can be valued in the model.
The first Hull–White model was described by John C. Hull and Alan White in 1990. The model is still popular in the market today.
The model
One-factor model
The model is a short-rate model. In general, it has the following dynamics:
There is a degree of ambiguity among practitioners about exactly which parameters in the model are time-dependent or what name to apply to the model in each case. The most commonly accepted naming convention is the following:
has t (time) dependence — the Hull–White model.
and are both time-dependent — the extended Vasicek model.
Two-factor model
The two-factor Hull–White model contains an additional disturbance term whose mean reverts to zero, and is of the form:
where is a deterministic function, typically the identity function (extension of the one-factor version, analytically tractable, and with potentially negative rates), the natural logarithm (extension of Black–Karasinksi, not analytically tractable, and with positive interest rates), or combinations (proportional to the natural log
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https://en.wikipedia.org/wiki/Dennis%20Schmitt
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Dennis Schmitt (born May 23, 1946) is a veteran explorer, adventurer and composer.
Early life
Schmitt grew up in Berkeley, California, the son of mixed German and American parentage. His father was a plumber. Displaying early aptitude with languages, music and mathematics, Schmitt graduated from Berkeley High School in 1963, and went on to study linguistics at UC Berkeley with Noam Chomsky in his late teens. Chomsky recruited Schmitt, aged 19, to travel to Alaska's Brooks Range and attempt to learn the Nunamiut dialect.
Career
Schmitt lived for four years at an Alaskan Eskimo village named Anaktuvuk Pass before leading expeditions, including the Sierra Club. In 2003, Schmitt discovered one of the candidates of being the northernmost land in the world. Deciding that Greenland should name its own islands, he simply called it "83-42", a name that has remained.
Two years later, in 2005, Schmitt discovered a new island formed by the retreat of an ice shelf in East Greenland. Uunartoq Qeqertaq, Inuit for "The Warming Island", lies 400 miles north of the Arctic Circle. The Sierra Club reported on a Schmitt quote to The New York Times:
"We felt the exhilaration of discovery. We were exploring something new. But of course, there was also something scary about what we did there. We were looking in the face of these changes, and all of us were thinking of the dire consequences."
Expeditions
Schmitt is also credited with the July 2007 discovery of another of the candidates to the "
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https://en.wikipedia.org/wiki/Michael%20A.%20Arbib
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Michael Anthony Arbib (born May 28, 1940) is an American computational neuroscientist. He is an Adjunct Professor of Psychology at the University of California at San Diego and professor emeritus at the University of Southern California; before his 2016 retirement he was the Fletcher Jones Professor of computer science, as well as a professor of biological sciences, biomedical engineering, electrical engineering, neuroscience and psychology.
Early life and education
Arbib was born in England on May 28, 1940, the oldest of four children. His parents moved to New Zealand when he was about 7, and on to Australia when he was about 9.
Arbib was educated in New Zealand and at The Scots College in Sydney, Australia. In 1960 he took a BSc (Hons) at the University of Sydney, with the University Medal in Pure Mathematics.
Arbib received his PhD in Mathematics from the Massachusetts Institute of Technology in 1963. He was advised by Norbert Wiener, the founder of cybernetics, and Henry McKean. As a student, he also worked with Warren McCulloch, the co-inventor of the artificial neural network and finite-state machine.
Career
Following his PhD, Arbib moved to Stanford for a postdoc with Rudolf E. Kálmán. Arbib spent five years at Stanford, before moving to become becoming the founding chairman of the Department of Computer and Information Science at the University of Massachusetts Amherst in 1970. He remained in the Department until 1986, when he joined the University of Souther
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https://en.wikipedia.org/wiki/Catenane
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In macromolecular chemistry, a catenane () is a mechanically interlocked molecular architecture consisting of two or more interlocked macrocycles, i.e. a molecule containing two or more intertwined rings. The interlocked rings cannot be separated without breaking the covalent bonds of the macrocycles. They are conceptually related to other mechanically interlocked molecular architectures, such as rotaxanes, molecular knots or molecular Borromean rings. Recently the terminology "mechanical bond" has been coined that describes the connection between the macrocycles of a catenane. Catenanes have been synthesised in two different ways: statistical synthesis and template-directed synthesis.
Synthesis
There are two primary approaches to the organic synthesis of catenanes. The first is to simply perform a ring-closing reaction with the hope that some of the rings will form around other rings giving the desired catenane product. This so-called "statistical approach" led to the first synthesis of a catenane; however, the method is highly inefficient, requiring high dilution of the "closing" ring and a large excess of the pre-formed ring, and is rarely used.
The second approach relies on supramolecular preorganization of the macrocyclic precursors utilizing hydrogen bonding, metal coordination, hydrophobic effect, or coulombic interactions. These non-covalent interactions offset some of the entropic cost of association and help position the components to form the desired catenane
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https://en.wikipedia.org/wiki/Principal%20part
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In mathematics, the principal part has several independent meanings, but usually refers to the negative-power portion of the Laurent series of a function.
Laurent series definition
The principal part at of a function
is the portion of the Laurent series consisting of terms with negative degree. That is,
is the principal part of at .
If the Laurent series has an inner radius of convergence of 0 , then has an essential singularity at , if and only if the principal part is an infinite sum. If the inner radius of convergence is not 0, then may be regular at despite the Laurent series having an infinite principal part.
Other definitions
Calculus
Consider the difference between the function differential and the actual increment:
The differential dy is sometimes called the principal (linear) part of the function increment Δy.
Distribution theory
The term principal part is also used for certain kinds of distributions having a singular support at a single point.
See also
Mittag-Leffler's theorem
Cauchy principal value
References
External links
Cauchy Principal Part at PlanetMath
Complex analysis
Generalized functions
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https://en.wikipedia.org/wiki/Programming%20Language%20Design%20and%20Implementation%20%28conference%29
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Programming Language Design and Implementation (PLDI) is an academic conference in computer science, in particular in the study of programming languages and compilers. PLDI is organized by the Association for Computing Machinery under the SIGPLAN interest group.
History
The precursor of PLDI was the Symposium on Compiler Optimization, held July 27–28, 1970 at the University of Illinois at Urbana-Champaign and chaired by Robert S. Northcote. That conference included papers by Frances E. Allen, John Cocke, Alfred V. Aho, Ravi Sethi, and Jeffrey D. Ullman. The first conference in the current PLDI series took place in 1979 under the name SIGPLAN Symposium on Compiler Construction in Denver, Colorado. The next Compiler Construction conference took place in 1982 in Boston, Massachusetts. The Compiler Construction conferences then alternated with SIGPLAN Conferences on Language Issues until 1988, when the conference was renamed to PLDI. From 1982 until 2001, the conference acronym was SIGPLAN 'xx. Starting in 2002, the initialism became PLDI 'xx, and in 2006 PLDI xxxx.
Conference locations and organizers
PLDI 2023 - SIGPLAN Conference on Programming Language Design and Implementation: Orlando, FL, United States
General Chair: Steve Blackburn
Program Chair: Nate Foster
PLDI 2022 - SIGPLAN Conference on Programming Language Design and Implementation: San Diego, CA, United States
General Chair: Ranjit Jhala
Program Chair: Isil Dillig
PLDI 2021 - SIGPLAN Conference on Progra
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https://en.wikipedia.org/wiki/Adams%20operation
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In mathematics, an Adams operation, denoted ψk for natural numbers k, is a cohomology operation in topological K-theory, or any allied operation in algebraic K-theory or other types of algebraic construction, defined on a pattern introduced by Frank Adams. The basic idea is to implement some fundamental identities in symmetric function theory, at the level of vector bundles or other representing object in more abstract theories.
Adams operations can be defined more generally in any λ-ring.
Adams operations in K-theory
Adams operations ψk on K theory (algebraic or topological) are characterized by the following properties.
ψk are ring homomorphisms.
ψk(l)= lk if l is the class of a line bundle.
ψk are functorial.
The fundamental idea is that for a vector bundle V on a topological space X, there is an analogy between Adams operators and exterior powers, in which
ψk(V) is to Λk(V)
as
the power sum Σ αk is to the k-th elementary symmetric function σk
of the roots α of a polynomial P(t). (Cf. Newton's identities.) Here Λk denotes the k-th exterior power. From classical algebra it is known that the power sums are certain integral polynomials Qk in the σk. The idea is to apply the same polynomials to the Λk(V), taking the place of σk. This calculation can be defined in a K-group, in which vector bundles may be formally combined by addition, subtraction and multiplication (tensor product). The polynomials here are called Newton polynomials (not, however, the Newton polynom
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https://en.wikipedia.org/wiki/Cohomology%20operation
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In mathematics, the cohomology operation concept became central to algebraic topology, particularly homotopy theory, from the 1950s onwards, in the shape of the simple definition that if F is a functor defining a cohomology theory, then a cohomology operation should be a natural transformation from F to itself. Throughout there have been two basic points:
the operations can be studied by combinatorial means; and
the effect of the operations is to yield an interesting bicommutant theory.
The origin of these studies was the work of Pontryagin, Postnikov, and Norman Steenrod, who first defined the Pontryagin square, Postnikov square, and Steenrod square operations for singular cohomology, in the case of mod 2 coefficients. The combinatorial aspect there arises as a formulation of the failure of a natural diagonal map, at cochain level. The general theory of the Steenrod algebra of operations has been brought into close relation with that of the symmetric group.
In the Adams spectral sequence the bicommutant aspect is implicit in the use of Ext functors, the derived functors of Hom-functors; if there is a bicommutant aspect, taken over the Steenrod algebra acting, it is only at a derived level. The convergence is to groups in stable homotopy theory, about which information is hard to come by. This connection established the deep interest of the cohomology operations for homotopy theory, and has been a research topic ever since. An extraordinary cohomology theory has its own co
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https://en.wikipedia.org/wiki/Pertactin
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In molecular biology, pertactin (PRN) is a highly immunogenic virulence factor of Bordetella pertussis, the bacterium that causes pertussis. Specifically, it is an outer membrane protein that promotes adhesion to tracheal epithelial cells. PRN is purified from Bordetella pertussis and is used for the vaccine production as one of the important components of acellular pertussis vaccine.
A large part of the N-terminus of the pertactin protein is composed of beta helix repeats. This region of the pertactin protein is secreted through the C-terminal autotransporter. The N-terminal signal sequences promotes the secretion of PRN into the periplasm through the bacterial secretion system (Sec) and consequently, the translocation into the outer membrane where it is proteolytically cleaved. The loops in the right handed β-helix of the N-terminus that protrudes out of cell surface (region R1) contains sequence repeats Gly-Gly-Xaa-Xaa-Pro and the RGD domain Arg-Gly-Asp. This RGD domain allows PRN to function as an adhesin and invasin, binding to integrins on the outer membrane of the cell. Another loop of the extending β-helix is region 2 (R2) which contains Pro-Gln-Pro (PQP) repeats towards the C-terminus. This protein’s contribution to immunity is still premature. Reports suggest that R1 and R2 are immunogenic regions, however, recent studies regarding genetic variation of those regions prove otherwise.
In B.bronchiseptica
Pertactin adheres to only ciliated epithelial cells of B. br
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https://en.wikipedia.org/wiki/Benzyl%20group
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In organic chemistry, benzyl is the substituent or molecular fragment possessing the structure . Benzyl features a benzene ring () attached to a methylene group () group.
Nomenclature
In IUPAC nomenclature, the prefix benzyl refers to a substituent, for example benzyl chloride or benzyl benzoate. Benzyl is not to be confused with phenyl with the formula .
The term benzylic is used to describe the position of the first carbon bonded to a benzene or other aromatic ring. For example, is referred to as a "benzylic" carbocation. The benzyl free radical has the formula . The benzyl cation or phenylcarbenium ion is the carbocation with formula ; the benzyl anion or phenylmethanide ion is the carbanion with the formula . None of these species can be formed in significant amounts in the solution phase under normal conditions, but they are useful referents for discussion of reaction mechanisms and may exist as reactive intermediates.
Abbreviations
Benzyl is most commonly abbreviated Bn. For example, benzyl alcohol can be represented as BnOH. Less common abbreviations are Bzl and Bz, the latter of which is ambiguous as it is also the standard abbreviation for the benzoyl group . Likewise, benzyl should not be confused with the phenyl group , abbreviated Ph.
Reactivity of benzylic centers
The enhanced reactivity of benzylic positions is attributed to the low bond dissociation energy for benzylic C−H bonds. Specifically, the bond is about 10–15% weaker than other kinds of C−H bonds
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https://en.wikipedia.org/wiki/Odd%20Hassel
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Odd Hassel (17 May 1897 – 11 May 1981) was a Norwegian physical chemist and Nobel Laureate.
Biography
Hassel was born in Kristiania (now Oslo), Norway. His parents were Ernst Hassel (1848–1905), a gynaecologist, and Mathilde Klaveness (1860–1955). In 1915, he entered the University of Oslo where he studied mathematics, physics and chemistry, and graduated in 1920. Victor Goldschmidt was Hassel's tutor when he began studies in Oslo, while Heinrich Jacob Goldschmidt, Victor's father, was Hassel's thesis advisor. Father and son were important figures in Hassel's life and they remained friends. After taking a year off from studying, he went to Munich, Germany to work in the laboratory of Professor Kasimir Fajans.
His work there led to the detection of absorption indicators. After moving to Berlin, he worked at the Kaiser Wilhelm Institute, where he began to do research on X-ray crystallography. He furthered his research with a Rockefeller Fellowship, obtained with the help of Fritz Haber. In 1924, he obtained his PhD from Humboldt University of Berlin, before moving to his alma mater, the University of Oslo, where he worked from 1925 through 1964. He became a professor in 1934.
His work was interrupted in October, 1943 when he and other university staff members were arrested by the Nasjonal Samling and handed over to the occupation authorities. He spent time in several detention camps, until he was released in November, 1944.
Work
Hassel originally focused on inorganic chemi
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https://en.wikipedia.org/wiki/Probabilistic%20argument
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Probabilistic argument may refer to:
Probabilistic argument, any argument involving probability theory
Probabilistic method, a method of non-constructive existence proof in mathematics
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https://en.wikipedia.org/wiki/T-square%20%28fractal%29
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In mathematics, the T-square is a two-dimensional fractal. It has a boundary of infinite length bounding a finite area. Its name comes from the drawing instrument known as a T-square.
Algorithmic description
It can be generated from using this algorithm:
Image 1:
Start with a square. (The black square in the image)
Image 2:
At each convex corner of the previous image, place another square, centered at that corner, with half the side length of the square from the previous image.
Take the union of the previous image with the collection of smaller squares placed in this way.
Images 3–6:
Repeat step 2.
The method of creation is rather similar to the ones used to create a Koch snowflake or a Sierpinski triangle, "both based on recursively drawing equilateral triangles and the Sierpinski carpet."
Properties
The T-square fractal has a fractal dimension of ln(4)/ln(2) = 2. The black surface extent is almost everywhere in the bigger square, for once a point has been darkened, it remains black for every other iteration; however some points remain white.
The fractal dimension of the boundary equals .
Using mathematical induction one can prove that for each n ≥ 2 the number of new squares that are added at stage n equals .
The T-Square and the chaos game
The T-square fractal can also be generated by an adaptation of the chaos game, in which a point jumps repeatedly half-way towards the randomly chosen vertices of a square. The T-square appears when the jumping point is un
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https://en.wikipedia.org/wiki/Manifold%20decomposition
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In topology, a branch of mathematics, a manifold M may be decomposed or split by writing M as a combination of smaller pieces. When doing so, one must specify both what those pieces are and how they are put together to form M.
Manifold decomposition works in two directions: one can start with the smaller pieces and build up a manifold, or start with a large manifold and decompose it. The latter has proven a very useful way to study manifolds: without tools like decomposition, it is sometimes very hard to understand a manifold. In particular, it has been useful in attempts to classify 3-manifolds and also in proving the higher-dimensional Poincaré conjecture.
The table below is a summary of the various manifold-decomposition techniques. The column labeled "M" indicates what kind of manifold can be decomposed; the column labeled "How it is decomposed" indicates how, starting with a manifold, one can decompose it into smaller pieces; the column labeled "The pieces" indicates what the pieces can be; and the column labeled "How they are combined" indicates how the smaller pieces are combined to make the large manifold.
See also
Surgery theory
Geometric topology
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https://en.wikipedia.org/wiki/Decomposition%20%28disambiguation%29
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Biology and ecology
Decomposition is the process through which organic matter is broken down into simpler molecules.
Decomposition, decompose may also refer to:
Chemistry
Chemical decomposition or analysis, in chemistry, is the fragmentation of a chemical compound into elements or smaller compounds
Thermal decomposition, a chemical decomposition caused by heat
Mathematics
Doob decomposition of an integrable, discrete-time stochastic process
Doob–Meyer decomposition of a continuous-time sub- or supermartingale
Hahn decomposition of a measure space
Hahn–Jordan decomposition of a signed measure
Helmholtz decomposition, decomposition of a vector field
Indecomposability (disambiguation)
Indecomposable continuum
Lebesgue's decomposition theorem, decomposition of a measure
Lie group decomposition, used to analyse the structure of Lie groups and associated objects
Manifold decomposition, decomposition of manifolds
JSJ decomposition, or toral decomposition, a decomposition of 3-manifolds
Matrix decomposition, decomposition of matrices
Primary decomposition, decomposition of ideals into primary ideals
Vector decomposition, decomposition of vectors
Permutation decomposition, decomposition of a permutation into disjoint cycles
Physics
Spinodal decomposition, phase separation mechanism
Other uses
Decomposition (computer science), or factoring; the process of breaking a complex problem down into easily understood and achievable parts
Semantic decomposition, used in natural language
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https://en.wikipedia.org/wiki/Forensic%20toxicology
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Forensic toxicology is the use of toxicology and disciplines such as analytical chemistry, pharmacology and clinical chemistry to aid medical or legal investigation of death, poisoning, and drug use. The primary concern for forensic toxicology is not the legal outcome of the toxicological investigation or the technology utilized, but rather the obtention and interpretation of results.
A toxicological analysis can be done to various kinds of samples.
A forensic toxicologist must consider the context of an investigation, in particular any physical symptoms recorded, and any evidence collected at a crime scene that may narrow the search, such as pill bottles, powders, trace residue, and any available chemicals. Provided with this information and samples with which to work, the forensic toxicologist must determine which toxic substances are present, in what concentrations, and the probable effect of those chemicals on the person.
In the United States, forensic toxicology can be separated into 3 disciplines: Postmortem toxicology, human performance toxicology, and forensic drug testing (FDT). Postmortem toxicology includes the analysis of biological specimens taken from an autopsy to identify the effect of drugs, alcohol, and poisons. A wide range of biological specimens may be analyzed including blood, urine, gastric contents, oral fluids, hair, tissues, and more. The forensic toxicologist works with pathologists, medical examiners, and coroners to help determine the cause and
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https://en.wikipedia.org/wiki/Zaitsev%27s%20rule
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In organic chemistry, Zaitsev's rule (or Saytzeff's rule, Saytzev's rule) is an empirical rule for predicting the favored alkene product(s) in elimination reactions. While at the University of Kazan, Russian chemist Alexander Zaitsev studied a variety of different elimination reactions and observed a general trend in the resulting alkenes. Based on this trend, Zaitsev proposed that the alkene formed in greatest amount is that which corresponded to removal of the hydrogen from the alpha-carbon having the fewest hydrogen substituents. For example, when 2-iodobutane is treated with alcoholic potassium hydroxide (KOH), but-2-ene is the major product and but-1-ene is the minor product.
More generally, Zaitsev's rule predicts that in an elimination reaction the most substituted product will be the most stable, and therefore the most favored. The rule makes no generalizations about the stereochemistry of the newly formed alkene, but only the regiochemistry of the elimination reaction. While effective at predicting the favored product for many elimination reactions, Zaitsev's rule is subject to many exceptions.
Many of them include exceptions under Hofmann product (analogous to Zaitsev product). These include compounds having quaternary nitrogen and leaving groups like NR3+, SO3H, etc. In these eliminations the Hofmann product is preferred. In case the leaving group is halogens, except fluorine; others give the Zaitsev product.
History
Alexander Zaitsev first published his observat
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https://en.wikipedia.org/wiki/David%20Gale
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David Gale (December 13, 1921 – March 7, 2008) was an American mathematician and economist. He was a professor emeritus at the University of California, Berkeley, affiliated with the departments of mathematics, economics, and industrial engineering and operations research. He has contributed to the fields of mathematical economics, game theory, and convex analysis.
Gale earned his B.A. from Swarthmore College, obtained an M.A. from the University of Michigan in 1947, and earned his Ph.D. in Mathematics at Princeton University in 1949. He taught at Brown University from 1950 to 1965 and then joined the faculty at the University of California, Berkeley.
Gale lived in Berkeley, California, and Paris, France with his partner Sandra Gilbert, feminist literary scholar and poet. He has three daughters and two grandsons.
Contribution
Gale's contributions to mathematical economics include an early proof of the existence of competitive equilibrium, his solution of the n-dimensional Ramsey problem, in the theory of optimal economic growth.
Gale and F. M. Stewart initiated the study of infinite games with perfect information. This work led to fundamental contributions to mathematical logic.
Gale is the inventor of the game of Bridg-It (also known as "Game of Gale") and Chomp.
Gale played a fundamental role in the development of the theory of linear programming and linear inequalities. His classic 1960 book The Theory of Linear Economic Models continues to be a standard reference
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https://en.wikipedia.org/wiki/Pierre%20Victor%20Auger
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Pierre Victor Auger (; 14 May 1899 – 24 December 1993) was a French physicist, born in Paris. He worked in the fields of atomic physics, nuclear physics, and cosmic ray physics. He is famous for being one of the discoverers of the Auger effect, named after him.
Early life
Pierre's father was chemistry professor Victor Auger. Pierre Auger was a student at the École normale supérieure in Paris from 1919 to 1922, the year when he passed the agrégation of physics. He then joined the physical chemistry laboratory of the faculté des sciences of the University of Paris under the direction of Jean Perrin to work there on the photoelectric effect.
Career
In 1926 he obtained his doctorate in physics from the University of Paris. In 1927, he was named assistant to the faculté des sciences of Paris and, at the same time, adjoint chief of service to l'Institut de biologie physico-chimique. Chief of work to faculty in 1934 and general secretary of the annual tables of the constants in 1936, he was named university lecturer in physics to the faculty on the first of November 1937. He was charged with, until 1940, the course on the experimental bases of the quantum theory within the chair of theoretical physics and astrophysics. He was also adjoint director of the laboratory of physical chemistry. He then occupied the chair of quantum physics and relativity of the faculté des sciences of Paris.
At the end of World War II, he was named director of higher education from 1945 to 1948, which p
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https://en.wikipedia.org/wiki/Light-gas%20gun
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The light-gas gun is an apparatus for physics experiments. It is a highly specialized gun designed to generate extremely high velocities. It is usually used to study high-speed impact phenomena (hypervelocity research), such as the formation of impact craters by meteorites or the erosion of materials by micrometeoroids. Some basic material research relies on projectile impact to create high pressure; such systems are capable of forcing liquid hydrogen into a metallic state.
Operation
A light-gas gun works on the same principle as a spring piston airgun. A large-diameter piston is used to force a gaseous working fluid through a smaller-diameter barrel containing the projectile to be accelerated. This reduction in diameter acts as a lever, increasing the speed while decreasing the pressure. In an airgun, the large piston is powered by a spring or compressed air, and the working fluid is atmospheric air.
In a light-gas gun, the piston is powered by a chemical reaction (usually gunpowder), and the working fluid is a lighter gas, such as helium or hydrogen (though helium is much safer to work with, hydrogen offers the best performance [as explained below] and causes less launch-tube erosion). One addition that a light-gas gun adds to the airgun is a rupture disk, which is a disk (usually metal) of carefully calibrated thickness designed to act as a valve. When the pressure builds up to the desired level behind the disk, the disk tears open, allowing the high-pressure, light gas
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https://en.wikipedia.org/wiki/Gyromagnetic%20ratio
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In physics, the gyromagnetic ratio (also sometimes known as the magnetogyric ratio in other disciplines) of a particle or system is the ratio of its magnetic moment to its angular momentum, and it is often denoted by the symbol , gamma. Its SI unit is the radian per second per tesla (rad⋅s−1⋅T−1) or, equivalently, the coulomb per kilogram (C⋅kg−1).
The term "gyromagnetic ratio" is often used as a synonym for a different but closely related quantity, the -factor. The -factor only differs from the gyromagnetic ratio in being dimensionless.
For a classical rotating body
Consider a nonconductive charged body rotating about an axis of symmetry. According to the laws of classical physics, it has both a magnetic dipole moment due to the movement of charge and an angular momentum due to the movement of mass arising from its rotation. It can be shown that as long as its charge and mass density and flow are distributed identically and rotationally symmetric, its gyromagnetic ratio is
where is its charge and is its mass.
The derivation of this relation is as follows. It suffices to demonstrate this for an infinitesimally narrow circular ring within the body, as the general result then follows from an integration. Suppose the ring has radius , area , mass , charge , and angular momentum . Then the magnitude of the magnetic dipole moment is
For an isolated electron
An isolated electron has an angular momentum and a magnetic moment resulting from its spin. While an electron's spi
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https://en.wikipedia.org/wiki/Asymmetric%20relation
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In mathematics, an asymmetric relation is a binary relation on a set where for all if is related to then is not related to
Formal definition
A binary relation on is any subset of Given write if and only if which means that is shorthand for The expression is read as " is related to by " The binary relation is called if for all if is true then is false; that is, if then
This can be written in the notation of first-order logic as
A logically equivalent definition is:
for all at least one of and is ,
which in first-order logic can be written as:
An example of an asymmetric relation is the "less than" relation between real numbers: if then necessarily is not less than The "less than or equal" relation on the other hand, is not asymmetric, because reversing for example, produces and both are true.
Asymmetry is not the same thing as "not symmetric": the less-than-or-equal relation is an example of a relation that is neither symmetric nor asymmetric. The empty relation is the only relation that is (vacuously) both symmetric and asymmetric.
Properties
A relation is asymmetric if and only if it is both antisymmetric and irreflexive.
Restrictions and converses of asymmetric relations are also asymmetric. For example, the restriction of from the reals to the integers is still asymmetric, and the inverse of is also asymmetric.
A transitive relation is asymmetric if and only if it is irreflexive: if and transitivity gives contradicting i
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https://en.wikipedia.org/wiki/Mildred%20Dresselhaus
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Mildred Dresselhaus ( Spiewak; November 11, 1930 – February 20, 2017), known as the "Queen of Carbon Science", was an American physicist, materials scientist, and nanotechnologist. She was an institute professor and professor of both physics and electrical engineering at the Massachusetts Institute of Technology. She also served as the president of the American Physical Society, the chair of the American Association for the Advancement of Science, as well as the director of science in the US Department of Energy under the Bill Clinton Government. Dresselhaus won numerous awards including the Presidential Medal of Freedom, the National Medal of Science, the Enrico Fermi Award, the Kavli Prize and the Vannevar Bush Award.
Early life and education
Dresselhaus was born on November 11, 1930, in Brooklyn, New York City, the daughter of Ethel (Teichtheil) and Meyer Spiewak, who were Polish Jewish immigrants. Her family was heavily affected by the Great Depression so from a young age Dresselhaus helped provide income for the family by doing piecework assembly tasks at home and by working in a zipper factory during the summer. As a grade school student, Dresselhaus' first 'teaching job' was tutoring a special-needs student for fifty cents a week, and she learned how to be a good teacher.
Dresselhaus credited New York's free museums, including the American Museum of Natural History and the Metropolitan Museum of Art, with sparking her interest in science. She and her brother, Irving
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https://en.wikipedia.org/wiki/Cyril%20Norman%20Hinshelwood
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Sir Cyril Norman Hinshelwood (19 June 1897 – 9 October 1967) was a British physical chemist and expert in chemical kinetics. His work in reaction mechanisms earned the 1956 Nobel Prize in chemistry.
Education
Born in London, his parents were Norman Macmillan Hinshelwood, a chartered accountant, and Ethel Frances née Smith. He was educated first in Canada, returning in 1905 on the death of his father to a small flat in Chelsea where he lived for the rest of his life. He then studied at Westminster City School and Balliol College, Oxford.
Career
During the First World War, Hinshelwood was a chemist in an explosives factory. He was a tutor at Trinity College, Oxford, from 1921 to 1937 and was Dr Lee's Professor of Chemistry at the University of Oxford from 1937. He served on several advisory councils on scientific matters to the British Government.
His early studies of molecular kinetics led to the publication of Thermodynamics for Students of Chemistry and The Kinetics of Chemical Change in 1926. With Harold Warris Thompson he studied the explosive reaction of hydrogen and oxygen and described the phenomenon of chain reaction. His subsequent work on chemical changes in the bacterial cell proved to be of great importance in later research work on antibiotics and therapeutic agents, and his book, The Chemical Kinetics of the Bacterial Cell was published in 1946, followed by Growth, Function and Regulation in Bacterial Cells in 1966. In 1951 he published The Structure of Physi
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https://en.wikipedia.org/wiki/The%20Nolans
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The Nolans were an Anglo-Irish girl group who formed in Blackpool in 1974 as the Nolan Sisters, before changing their name in 1980. From 1979 to 1982, the group had a run of hits, including "I'm in the Mood for Dancing", "Gotta Pull Myself Together", "Who's Gonna Rock You", "Attention to Me" and "Chemistry". They are one of the world's biggest selling girl groups. They were particularly successful in Japan, becoming the first European act to win the Tokyo Music Festival with "Sexy Music" in 1981, and won a Japanese Grammy (Tokubetsu Kikaku Shō) in 1992.
History
1962–1974: Early career
Tommy (26 September 1925–1998) and Maureen Nolan (15 December 1926 – 30 December 2007) met at Clerys Ballroom in Dublin and raised their family in Raheny, Dublin. Tommy had a radio show on RTÉ. Due to the lack of work the young family moved from Dublin to Blackpool in 1962, and launched a family singing group, the Singing Nolans, in 1963. The original line-up comprised the parents, and seven of their eight children: sons Tommy (born 20 July 1949) and Brian (born 19 June 1955), and daughters Anne (born 12 November 1950), Denise (born 6 April 1952), Maureen (born 14 June 1954), Linda (born 23 February 1959), and Bernadette ('Bernie', 17 October 1960 – 4 July 2013). The youngest member, Coleen, (born 12 March 1965), did not formally join the group until 1980 as she was too young to perform with her sisters.
The family performed even as the five girls went to school at Blackpool's St Mary's Catho
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https://en.wikipedia.org/wiki/Gavin%20Schmidt
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Gavin A. Schmidt is a British climatologist, climate modeler and Director of the NASA Goddard Institute for Space Studies (GISS) in New York, and co-founder of the award-winning climate science blog RealClimate.
Work
He was educated at The Corsham School, earned a BA (Hons) in mathematics at Jesus College, Oxford, and a PhD in applied mathematics at University College London. Schmidt worked on the variability of the ocean circulation and climate, using general circulation models (GCMs). He has also worked on ways to reconcile paleo-data with models. He helped develop the GISS ocean and coupled GCMs to improve the representation of the present day climate, while investigating their response to climate forcing.
NASA named Schmidt to head GISS in June 2014. He stepped into the position left vacant after the retirement of long-time director James E. Hansen, becoming the third person to hold the post.
In an interview with Science News, Schmidt said that he wanted to continue the institute's work on climate modeling and to expand its work on climate impacts and astrobiology.
Research
His main research interest is climate variability, both its internal and the response to climate forcing, investigated via ocean-atmosphere general circulation models. He also uses these to study palaeoclimate by working on methods to compare palaeo-data with model output. Schmidt helps to develop the GISS ocean and coupled GCMs (ModelE). This model has been "isotopically enabled" to carry oxygen-18
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