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https://en.wikipedia.org/wiki/Hugh%20Ross%20%28astrophysicist%29
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Hugh Norman Ross (born July 24, 1945) is a Canadian astrophysicist, Christian apologist, and old-Earth creationist.
Ross obtained his Ph.D. in astronomy from the University of Toronto and his B.Sc. degree in physics from the University of British Columbia. He established his own ministry in 1986, called Reasons to Believe.
Ross rejects both abiogenesis and evolution as explanations for the origin and history of life, contrary to the scientific consensus. Ross' position overlaps with that of intelligent design, but Ross argues that the evidence points to Jesus Christ as the designer, instead of an undefined intelligent designer.
Early life and education
Hugh Ross was born in Montreal, Quebec, and raised in Vancouver, British Columbia after moving there at the age of five. His parents were James Stewart Alexander Ross and Dorothy Isabel (Murray) Ross.He was interested in science from a young age, often reading science textbooks as a child.
As a teenager, Ross read works by philosophers such as Immanuel Kant and Rene Descartes, but felt their works contained inconsistencies and contradictions. Ross also read Eastern holy books from religions such as Hinduism, Buddhism, and Zoroastrianism. He began studying the Bible in secret due to his family's disapproval. He was inspired by the way the Bible described historical and scientific information, eventually becoming a Christian.
Ross described his upbringing as moral, but not religious. Ross became interested in astronomy at
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https://en.wikipedia.org/wiki/D%27Agapeyeff%20cipher
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The D'Agapeyeff cipher is an unsolved cipher that appears in the first edition of Codes and Ciphers, an elementary book on cryptography published by the Russian-born English cryptographer and cartographer Alexander D'Agapeyeff in 1939.
Offered as a "challenge cipher" at the end of the book, the ciphertext is:
It was not included in later editions, and D'Agapeyeff is said to have admitted later to having forgotten how he had encrypted it.
Use of nulls in ciphertext
It is possible that not all the ciphertext characters are used in decryption and that some characters are nulls. Evidence for this is given by the author on p. 111 of the text under the sub-section heading Military Codes and Ciphers:
"The cipher is of course easily made out, but if every third, fourth, or fifth letter, as may be previously arranged, is a dummy inserted after a message has been put into cipher, it is then extremely difficult to decipher unless you are in the secret."
While the index of coincidence for the D'Agapeyeff cipher is 1.812 when taken in pairs horizontally (e.g., '75' '62' '82'), the letter frequency distribution is too flat for a 196 character message written in English.
Additionally, D'Agapeyeff left two ciphers for the reader to solve. Each are approximately 100 characters in length and have an index of coincidence much higher than what is expected for English plaintext.
Use of Polybius square methods in Codes and Ciphers
The structure of the D'Agapeyeff Cipher has similarities
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https://en.wikipedia.org/wiki/Binoy%20Majumdar
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Binoy Majumdar () (17 September 1934 – 11 December 2006) was a Bengali poet that had received the Sahitya Akademi Award in 2005.
Biography
Binoy Majumdar was born in Myanmar (erstwhile Burma) on 17 September 1934. His family later moved to what is now Thakurnagar West Bengal in India. Binoy loved mathematics from his early youth. He completed 'Intermediate' (pre-University) from the Presidency College of the University of Calcutta. Although he graduated with a degree in mechanical engineering graduate from Bengal Engineering College, now renamed Indian Institute of Engineering Science & Technology, (IIT) Calcutta, in 1957, Binoy turned to poetry later in life. He translated a number of science texts from the Russian to Bengali. When Binoy took to writing, the scientific training of systematic observation and enquiry of objects found a place, quite naturally, in his poetry. His first book of verse was Nakshatrer Aloy (in the light of the stars). However, Binoy Majumdar's most famous piece of work to date is Phire Esho, Chaka (Come back, O Wheel, 1960), which was written in the format of a diary. The book is dedicated to Gayatri Chakravorty Spivak, a fellow-Calcuttan and contemporary of Majumdar. Professor Narayan Ch Ghosh has written number of articles on the writings of Binoy Majumder analysing mathematical aspects of Binoy's poems. According to Ghosh Phire Esho, Chaka(Come back, O Wheel) published during 1960 was reflection of Binoy's mind for recalling progress - wheel sy
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https://en.wikipedia.org/wiki/Rudolf%20Signer
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Rudolf Signer (17 March 1903, Herisau, Switzerland – 1 December 1990, Gümlingen, Switzerland) contributed to the discovery of the DNA double helix. He was a Professor for organic chemistry at the University of Bern from 1935 until 1972.
Education
Signer was the son of Jakob Signer, a chemical scientist working in the textile industry, and his wife Dorothea Agnes Scherrer. Rudolf Signer went to high school in St. Gallen and matriculated at the ETH Zurich in 1921 to study chemistry, initially in order to become a teacher. 1927 he graduated with his doctorate under the supervision of Hermann Staudinger. Already 1926 he had become Wissenschaftlicher Assistent at the University of Fribourg, where he qualified as a professor with a Habilitation.
Career
Signer spent 1932–1933 in Uppsala and Manchester on a Rockefeller-scholarship. He became a non-tenured professor for general and inorganic chemistry at the University of Bern in 1935 and was tenured in 1939. He went on to become director of the university's Institute of Chemistry and retired as emeritus in 1972.
Research
Signer focused on macromolecular chemistry, in particular with regards to natural products. In 1938 he measured and described the properties of DNA, discovering its thread-like structure. In 1950 Signer produced extraordinarily pure DNA from the thymus of calves, of which he took 15 grams of extraordinarily pure DNA to London. In England he gave it to various scientists, among them Maurice Wilkins, in order to p
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https://en.wikipedia.org/wiki/Cosmological%20horizon
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A cosmological horizon is a measure of the distance from which one could possibly retrieve information. This observable constraint is due to various properties of general relativity, the expanding universe, and the physics of Big Bang cosmology. Cosmological horizons set the size and scale of the observable universe. This article explains a number of these horizons.
Particle horizon
The particle horizon, also called the cosmological horizon, the comoving horizon, or the cosmic light horizon, is the maximum distance from which light from particles could have traveled to the observer in the age of the universe. It represents the boundary between the observable and the unobservable regions of the universe, so its distance at the present epoch defines the size of the observable universe. Due to the expansion of the universe, it is not simply the age of the universe times the speed of light, as in the Hubble horizon, but rather the speed of light multiplied by the conformal time. The existence, properties, and significance of a cosmological horizon depend on the particular cosmological model.
In terms of comoving distance, the particle horizon is equal to the conformal time that has passed since the Big Bang, times the speed of light. In general, the conformal time at a certain time is given in terms of the scale factor by,
or
The particle horizon is the boundary between two regions at a point at a given time: one region defined by events that have already been observed by an
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https://en.wikipedia.org/wiki/ZetaGrid
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ZetaGrid was at one time the largest distributed computing project, designed to explore the non-trivial roots of the Riemann zeta function, checking over one billion roots a day.
Roots of the zeta function are of particular interest in mathematics; a single root out of alignment would disprove the Riemann hypothesis, with far-reaching consequences for all of mathematics. , no counterexample to the Riemann hypothesis has been found.
The project ended in November 2005 due to instability of the hosting provider. The first more than 1013 zeroes were checked. The project administrator stated that after the results were analyzed, they would be posted on the American Mathematical Society website. The official status remains unclear, however, as it was never published nor independently verified. This is likely because there was no evidence that each zero was actually computed, as there was no process implemented to check each one as it was calculated.
References
External links
Home page (Web archive)
Grid computing
Zeta and L-functions
Hilbert's problems
Experimental mathematics
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https://en.wikipedia.org/wiki/Patrick%20Aebischer
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Patrick Aebischer (born 22 November 1954 in Fribourg, Switzerland) has been the president of the École polytechnique fédérale de Lausanne (EPFL) from 17 March 2000 to 31 December 2016. He is also a professor in neuroscience and head of the Neurodegenerative Disease Laboratory at the EPFL.
Education
Aebischer was trained as an MD (1980) and a neuroscientist (Dr. Med., 1983) at the University of Geneva and University of Fribourg in Switzerland.
Academic career
From 1984 to 1992, he worked at Brown University in Providence (Rhode Island, United States), as Research Scientist, Assistant and then associate professor of Medical Sciences. In 1991, he became the chairman of the Section of Artificial Organs, Biomaterials and Cellular Technology of the Division of Biology and Medicine of Brown University.
In autumn 1992, he returned to Switzerland as a professor and director of the Surgical Research Division and Gene Therapy Center at the University Hospital of Lausanne (CHUV) in Lausanne.
In 1999, Aebischer was nominated President of the École polytechnique fédérale de Lausanne (EPFL), one of the two Swiss Federal Institutes of Technology, by the Swiss Federal Council. He took office as president in March 2000 and was reelected to this position in 2004 and 2008. He has decided to leave this position at the end of 2016. Since 1 January 2017, the president of the EPFL is Martin Vetterli.
His current research focuses on the development of cell and gene transfer approaches for the t
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https://en.wikipedia.org/wiki/Unifying%20Theories%20of%20Programming
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Unifying Theories of Programming (UTP) in computer science deals with program semantics. It shows how denotational semantics, operational semantics and algebraic semantics can be combined in a unified framework for the formal specification, design and implementation of programs and computer systems.
The book of this title by C.A.R. Hoare and He Jifeng was published in the Prentice Hall International Series in Computer Science in 1998 and is now freely available on the web.
Theories
The semantic foundation of the UTP is the first-order predicate calculus, augmented with fixed point constructs from second-order logic. Following the tradition of Eric Hehner, programs are predicates in the UTP, and there is no distinction between programs and specifications at the semantic level. In the words of Hoare:
A computer program is identified with the strongest predicate describing every relevant observation that can be made of the behaviour of a computer executing that program.
In UTP parlance, a theory is a model of a particular programming paradigm. A UTP theory is composed of three ingredients:
an alphabet, which is a set of variable names denoting the attributes of the paradigm that can be observed by an external entity;
a signature, which is the set of programming language constructs intrinsic to the paradigm; and
a collection of healthiness conditions, which define the space of programs that fit within the paradigm. These healthiness conditions are typically expressed as m
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https://en.wikipedia.org/wiki/He%20Jifeng
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He Jifeng (, born August 1943) is a Chinese computer scientist.
He Jifeng graduated from the mathematics department of Fudan University in 1965. From 1965 to 1985, he was an instructor at East China Normal University. During 1980–81, he was a visiting scholar at Stanford University and the University of San Francisco in California, United States.
From 1984 to 1998, He Jifeng was a senior research fellow at the Programming Research Group in the Oxford University Computing Laboratory (now the Oxford University Department of Computer Science). He worked extensively on formal aspects of computing science. In particular, he worked with Prof. Sir Tony Hoare, latterly on Unifying Theories of Programming, resulting in a book of that name.
Since 1986, He Jifeng has been Professor of Computer Science at East China Normal University in Shanghai. In 1996, he also became Professor of Computer Science at Shanghai Jiao Tong University.
In 1998, he became a senior research fellow at the International Institute for Software Technology (UNU-IIST), United Nations University, based in Macau. He moved back to Shanghai in 2005.
He Jifeng's research interests include sound methods for the specification of computer systems, communications, applications, standards, and techniques for designing and implementing those specifications in software and/or hardware with high reliability.
In 2005, he was elected to the Chinese Academy of Sciences. In 2013, his 70th birthday was celebrated at East Chin
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https://en.wikipedia.org/wiki/Sessile%20drop%20technique
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In materials science, the sessile drop technique is a method used for the characterization of solid surface energies, and in some cases, aspects of liquid surface energies. The main premise of the method is that by placing a droplet of liquid with a known surface energy and contact angle, the surface energy of the solid substrate can be calculated. The liquid used for such experiments is referred to as the probe liquid, and the use of several different probe liquids is required.
Probe liquid
The surface energy is measured in units of joules per square meter, which is equivalent in the case of liquids to surface tension, measured in newtons per meter. The overall surface tension/energy of a liquid can be acquired through various methods using a tensiometer or using the pendant drop method and maximum bubble pressure method.
The interface tension at the interface of the probe liquid and the solid surface can additionally be viewed as being the result of different types of intermolecular forces. As such, surface energies can be subdivided according to the various interactions that cause them, such as the surface energy due to dispersive (e.g. van der Waals forces) and other interactions (e.g. hydrogen bonding, polar interactions, acid–base interactions, etc.). It is often useful for the sessile drop technique to use liquids that are known to be incapable of some of those interactions (see table 1). For example, the surface tension of all straight alkanes is said to be entirel
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https://en.wikipedia.org/wiki/Mario%20Bettinus
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Mario Bettinus (Italian name: Mario Bettini; 6 February 1582 – 7 November 1657) was an Italian Jesuit philosopher, mathematician and astronomer. The lunar crater Bettinus was named after him by Giovanni Riccioli in 1651.
Biography
Mario Bettinus studied mathematics under the Belgian Jean Verviers and Giuseppe Biancani at the Jesuit school in Parma. He was responsible for teaching military architecture in Parma during the period 1624–1630. Among the students attending his classes at the seminarium nobilium were the two sons of Duke Ranuccio, Ottavio and Odoardo. Besides being Ottavio's teacher of military mathematics, Bettinus also served as military consultant to the courts of Parma (1612–1613), Modena (1617–1618) and again Parma (1626–1627), and as a military architect at Novellara (1618–1619), seat of the novitiate of the Jesuit ‘Provincia Veneta’.
Besides being the mentor of Guarino Guarini (1624–1683), Bettinus was also a close friend of Prince Raimondo Montecuccoli (1609–1680)—the latter had even sent him a copy of his work on fortifications from Hohenneg on 15 July 1652.
Works
Bettinus privileged mathematics, intended as the only discipline abstract enough to allow intellect to approach theology. The Jesuit mathematician held the belief that, precisely because of their abstraction, mathematical theorems and demonstrations lead one away from the mundane and toward the divine. On the contrary, he considered a research based on sense as too bound to human limitations
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https://en.wikipedia.org/wiki/Hoist%20controller
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A hoist controller is the controller for a hoist. The term is used primarily in the context of electrically operated hoists, but it is apparent that the control systems of many 20th century steam hoists also incorporated controllers of significant complexity. Consider the control system of the Quincy Mine No. 2 Hoist. This control system included interlocks to close the throttle valve at the end of trip and to prevent opening the throttle again until the winding engine was reversed. The control system also incorporated a governor to control the speed of the hoist and indicator wheels to show the hoist operator the positions of the skips in the mine shaft.
The hoist controllers for modern electric mining hoists have long included such features as automatic starting of the hoist when the weight of coal or ore in the skip reaches a set point, automatic acceleration of the hoist to full speed and automatic deceleration at the end of travel.
Hoist controllers need both velocity and absolute position references taken, typically taken from the winding drum of the hoist. Modern hoist controllers replace many of the mechanical analog mechanisms of earlier controllers with digital control systems.
See also
Hydraulic hooklift hoist
References
Mining equipment
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https://en.wikipedia.org/wiki/Riemannian%20submersion
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In differential geometry, a branch of mathematics, a Riemannian submersion is a submersion from one Riemannian manifold to another that respects the metrics, meaning that it is an orthogonal projection on tangent spaces.
Formal definition
Let (M, g) and (N, h) be two Riemannian manifolds and a (surjective) submersion, i.e., a fibered manifold. The horizontal distribution is a sub-bundle of the tangent bundle of which depends both on the projection and on the metric .
Then, f is called a Riemannian submersion if and only if, for all , the vector space isomorphism is isometric, i.e., length-preserving.
Examples
An example of a Riemannian submersion arises when a Lie group acts isometrically, freely and properly on a Riemannian manifold .
The projection to the quotient space equipped with the quotient metric is a Riemannian submersion.
For example, component-wise multiplication on by the group of unit complex numbers yields the Hopf fibration.
Properties
The sectional curvature of the target space of a Riemannian submersion can be calculated from the curvature of the total space by O'Neill's formula, named for Barrett O'Neill:
where are orthonormal vector fields on , their horizontal lifts to , is the Lie bracket of vector fields and is the projection of the vector field to the vertical distribution.
In particular the lower bound for the sectional curvature of is at least as big as the lower bound for the sectional curvature of .
Generalizations and varia
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https://en.wikipedia.org/wiki/Five-dimensional%20space
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A five-dimensional space is a space with five dimensions. In mathematics, a sequence of N numbers can represent a location in an N-dimensional space. If interpreted physically, that is one more than the usual three spatial dimensions and the fourth dimension of time used in relativistic physics. Whether or not the universe is five-dimensional is a topic of debate.
Physics
Much of the early work on five-dimensional space was in an attempt to develop a theory that unifies the four fundamental interactions in nature: strong and weak nuclear forces, gravity and electromagnetism. German mathematician Theodor Kaluza and Swedish physicist Oskar Klein independently developed the Kaluza–Klein theory in 1921, which used the fifth dimension to unify gravity with electromagnetic force. Although their approaches were later found to be at least partially inaccurate, the concept provided a basis for further research over the past century.
To explain why this dimension would not be directly observable, Klein suggested that the fifth dimension would be rolled up into a tiny, compact loop on the order of 10 centimeters. Under his reasoning, he envisioned light as a disturbance caused by rippling in the higher dimension just beyond human perception, similar to how fish in a pond can only see shadows of ripples across the surface of the water caused by raindrops. While not detectable, it would indirectly imply a connection between seemingly unrelated forces. The KaluzaKlein theory experienced
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https://en.wikipedia.org/wiki/Carl%20F.%20W.%20Borgward
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Carl Friedrich Wilhelm Borgward (10 November 1890 in Altona, Hamburg – 28 July 1963 in Bremen) was a German engineer and designer and the creator of the Borgward group, based in Bremen.
Biography
He was of modest origin, the son of coal retailer Wilhelm Borgward, and had twelve brothers and sisters. He undertook mechanical engineering studies, and obtained his engineering degree from Hannover Technical University in 1913.
He was wounded during World War I. In 1919 he became one of the partners of Bremer Reifenindustrie. The company was restructured and in 1920 became Bremer Kühlerfabrik Borgward & Co.
In 1924 and 1925 the company started to produce the small three-wheel trucks Blitzkarren and Goliath. With his partner Wilhelm Tecklenborg, in 1928 he created the company Goliath-Werke Borgward & Co. When the two associates took over Hansa-Lloyd-Werke in 1931, this became the Borgward Group.
On 23 September 1938 the Carl F. W. Borgward Automobil- und Motorenwerke factory was opened in Sebaldsbrück near Bremen. At that time the company had 22,000 employees. Until the end of the war the production of Borgward was primarily military vehicles.
When the factory was destroyed by bombing in 1944, half of the workers were prisoners of war and forced laborers. Carl Borgward was interned until 1948. One year after being freed, he was again a member of the Chamber of Commerce and Industry of Bremen.
In 1949, the first Lloyd LP 300 had been designed and produced. In Germany this car
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https://en.wikipedia.org/wiki/Whitney%20disk
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In mathematics, given two submanifolds A and B of a manifold X intersecting in two points p and q, a Whitney disc is a mapping from the two-dimensional disc D, with two marked points, to X, such that the two marked points go to p and q, one boundary arc of D goes to A and the other to B.
Their existence and embeddedness is crucial in proving the cobordism theorem, where it is used to cancel the intersection points; and its failure in low dimensions corresponds to not being able to embed a Whitney disc. Casson handles are an important technical tool for constructing the embedded Whitney disc relevant to many results on topological four-manifolds.
Pseudoholomorphic Whitney discs are counted by the differential in Lagrangian intersection Floer homology.
References
Geometric topology
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https://en.wikipedia.org/wiki/Tetraborate
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In chemistry, tetraborate or pyroborate is an anion (negative ion) with formula ; or a salt containing that anion, such as sodium tetraborate, . It is one of the boron oxoacids, that is, a borate.
The name is also applied to the hydrated ion as present in borax
The ion occurs in boric acid solutions at neutral pH, being formed by condensation of orthoborate and tetrahydroxyborate anions:
2 B(OH)3 + 2 ⇌ + 5 H2O
The tetraborate anion (tetramer) includes two tetrahedral and two trigonal boron atoms symmetrically assembled in a fused bicyclic structure. The two tetrahedral boron atoms are linked together by a common oxygen atom, and each also bears a negative net charge brought by the supplementary OH− groups laterally attached to them. This intricate molecular anion also exhibits three rings: two fused distorted hexagonal (boroxole) rings and one distorted octagonal ring. Each ring is made of a succession of alternate boron and oxygen atoms. Boroxole rings are a very common structural motif in polyborate ions.
The hydrated tetraborate anion occurs in the mineral borax (sodium tetraborate octahydrate) with the formula Na2[B4O5(OH)4]·8H2O. The borax chemical formula is also commonly written in a more compact notation as Na2B4O7·10H2O. Sodium borate can be obtained in high purity and so can be used to make a standard solution in titrimetric analysis.
References
Anions
Salts
Sodium
Borates
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https://en.wikipedia.org/wiki/Uranium%20metallurgy
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In materials science and materials engineering, uranium metallurgy is the study of the physical and chemical behavior of uranium and its alloys.
Commercial-grade uranium can be produced through the reduction of uranium halides with alkali or alkaline earth metals. Uranium metal can also be made through electrolysis of KUF5 or UF4, dissolved in a molten CaCl2 and NaCl. Very pure uranium can be produced through the thermal decomposition of uranium halides on a hot filament.
The uranium isotope 235U is used as the fuel for nuclear reactors and nuclear weapons. It is the only isotope existing in nature to any appreciable extent that is fissile, that is, fissionable by thermal neutrons. The isotope 238U is also important because it absorbs neutrons to produce a radioactive isotope that subsequently decays to the isotope 239Pu (plutonium), which also is fissile. Uranium in its natural state comprises just 0.71% 235U and 99.3% 238U, and the main focus of uranium metallurgy is the enrichment of uranium through isotope separation.
See also
Nuclear weapon design#Enriched materials
Uranium tile
References
Sources
Uranium
Enriched uranium
Nuclear weapon design
The technology of mining and metallurgy , retrieved 7 October 2005.
External links
The technology of mining and metallurgy
Building nuclear warheads: The process
List of Uranium Alloys
Uranium
Metallurgy
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https://en.wikipedia.org/wiki/WalkSAT
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In computer science, GSAT and WalkSAT are local search algorithms to solve Boolean satisfiability problems.
Both algorithms work on formulae in Boolean logic that are in, or have been converted into conjunctive normal form. They start by assigning a random value to each variable in the formula. If the assignment satisfies all clauses, the algorithm terminates, returning the assignment. Otherwise, a variable is flipped and the above is then repeated until all the clauses are satisfied. WalkSAT and GSAT differ in the methods used to select which variable to flip.
GSAT makes the change which minimizes the number of unsatisfied clauses in the new assignment, or with some probability picks a variable at random.
WalkSAT first picks a clause which is unsatisfied by the current assignment, then flips a variable within that clause. The clause is picked at random among unsatisfied clauses. The variable is picked that will result in the fewest previously satisfied clauses becoming unsatisfied, with some probability of picking one of the variables at random. When picking at random, WalkSAT is guaranteed at least a chance of one out of the number of variables in the clause of fixing a currently incorrect assignment. When picking a guessed-to-be-optimal variable, WalkSAT has to do less calculation than GSAT because it is considering fewer possibilities.
Both algorithms may restart with a new random assignment if no solution has been found for too long, as a way of getting out of local
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https://en.wikipedia.org/wiki/Svyatoslav%20Piskun
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Svyatoslav Mykhaylovych Piskun (, born 1 March 1959) was 3 times Prosecutor General of Ukraine. He served in this role in 2002–2003, 2005 and 2007 until President Viktor Yushchenko's dismissed Piskun on 24 May 2007. He worked as a prosecutor in several important cases, including murder of Georgiy Gongadze and investigation of United Energy Systems of Ukraine.
Political career
In March 2006 he was elected as a people's deputy of the Verkhovna Rada from Party of Regions list as No.96 – but he was not a party member. Piskun was elected in parliament for Party of Regions again in 2007. He became a full member of Party of Regions in October 2008. Piskun did not return to parliament after the 2012 Ukrainian parliamentary election after losing in single-member districts number 63 (first-past-the-post wins a parliament seat) located in Zhytomyr Oblast. In the 2014 Ukrainian parliamentary election Khoroshkovskyi tried to return to national politics this time from the party of Strong Ukraine (placing 16th on the parties election list). But in the election the party failed to clear the 5% election threshold (it got 3.11% of the votes) and thus Piskun was not elected into parliament. Piskun was only allowed to take part in the election after a court decision validated his entrance in the election, at first the Central Election Commission of Ukraine had refused to register him because in the last 5 years leading up to the election he had not lived in Ukraine.
Dismissals as Prosecutor Ge
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https://en.wikipedia.org/wiki/Leray%20cover
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In mathematics, a Leray cover(ing) is a cover of a topological space which allows for easy calculation of its cohomology. Such covers are named after Jean Leray.
Sheaf cohomology measures the extent to which a locally exact sequence on a fixed topological space, for instance the de Rham sequence, fails to be globally exact. Its definition, using derived functors, is reasonably natural, if technical. Moreover, important properties, such as the existence of a long exact sequence in cohomology corresponding to any short exact sequence of sheaves, follow directly from the definition. However, it is virtually impossible to calculate from the definition. On the other hand, Čech cohomology with respect to an open cover is well-suited to calculation, but of limited usefulness because it depends on the open cover chosen, not only on the sheaves and the space. By taking a direct limit of Čech cohomology over arbitrarily fine covers, we obtain a Čech cohomology theory that does not depend on the open cover chosen. In reasonable circumstances (for instance, if the topological space is paracompact), the derived-functor cohomology agrees with this Čech cohomology obtained by direct limits. However, like the derived functor cohomology, this cover-independent Čech cohomology is virtually impossible to calculate from the definition. The Leray condition on an open cover ensures that the cover in question is already "fine enough." The derived functor cohomology agrees with the Čech coh
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https://en.wikipedia.org/wiki/Ambient%20space%20%28mathematics%29
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In mathematics, especially in geometry and topology, an ambient space is the space surrounding a mathematical object along with the object itself. For example, a 1-dimensional line may be studied in isolation —in which case the ambient space of is , or it may be studied as an object embedded in 2-dimensional Euclidean space —in which case the ambient space of is , or as an object embedded in 2-dimensional hyperbolic space —in which case the ambient space of is . To see why this makes a difference, consider the statement "Parallel lines never intersect." This is true if the ambient space is , but false if the ambient space is , because the geometric properties of are different from the geometric properties of . All spaces are subsets of their ambient space.
See also
Configuration space
Geometric space
Manifold and ambient manifold
Submanifolds and Hypersurfaces
Riemannian manifolds
Ricci curvature
Differential form
References
Further reading
Geometry
Topology
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https://en.wikipedia.org/wiki/Multi-armed%20bandit
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In probability theory and machine learning, the multi-armed bandit problem (sometimes called the K- or N-armed bandit problem) is a problem in which a fixed limited set of resources must be allocated between competing (alternative) choices in a way that maximizes their expected gain, when each choice's properties are only partially known at the time of allocation, and may become better understood as time passes or by allocating resources to the choice. This is a classic reinforcement learning problem that exemplifies the exploration–exploitation tradeoff dilemma. The name comes from imagining a gambler at a row of slot machines (sometimes known as "one-armed bandits"), who has to decide which machines to play, how many times to play each machine and in which order to play them, and whether to continue with the current machine or try a different machine. The multi-armed bandit problem also falls into the broad category of stochastic scheduling.
In the problem, each machine provides a random reward from a probability distribution specific to that machine, that is not known a-priori. The objective of the gambler is to maximize the sum of rewards earned through a sequence of lever pulls. The crucial tradeoff the gambler faces at each trial is between "exploitation" of the machine that has the highest expected payoff and "exploration" to get more information about the expected payoffs of the other machines. The trade-off between exploration and exploitation is also faced in machi
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https://en.wikipedia.org/wiki/Craig%20Stanford
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Craig Stanford is Professor of Biological Sciences and Anthropology at the University of Southern California. He is also a Research Associate in the herpetology section of the Los Angeles County Natural History Museum. He is known for his field studies of the behavior, ecology and conservation biology of chimpanzees, mountain gorillas and other tropical animals, and has published more than 140 scientific papers and 17 books on animal behavior, human evolution and wildlife conservation. He is best known for his field study of the predator–prey ecology of chimpanzees and the animals they hunt in Gombe National Park, Tanzania, and for his long term study of the behavior and ecology of chimpanzees and mountain gorillas in Bwindi Impenetrable National Park, Uganda.
He is also a herpetologist and involved in research and conservation of tortoises and turtles. He is Chair of the IUCN SSC Tortoise and Freshwater Turtle Specialist Group, and is on the board of the Turtle Conservancy.
Background
Stanford received his BA in anthropology and zoology at Drew University, his MA in anthropology at Rutgers University, and his PhD in anthropology at the University of California, Berkeley in 1990. He taught at the University of Michigan and joined the University of Southern California in 1992. He has received numerous grants from the National Science Foundation, National Geographic Society, Wenner Gren Foundation, Leakey Foundation, among others. He has also received several major teachi
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https://en.wikipedia.org/wiki/Nine-volt%20battery
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The nine-volt battery, or 9-volt battery, is an electric battery that supplies a nominal voltage of 9 volts. Actual voltage measures 7.2 to 9.6 volts, depending on battery chemistry. Batteries of various sizes and capacities are manufactured; a very common size is known as PP3, introduced for early transistor radios. The PP3 has a rectangular prism shape with rounded edges and two polarized snap connectors on the top. This type is commonly used for many applications including household uses such as smoke and gas detectors, clocks, and toys.
The nine-volt PP3-size battery is commonly available in primary zinc-carbon and alkaline chemistry, in primary lithium iron disulfide and lithium manganese dioxide (sometimes designated CRV9), and in rechargeable form in nickel-cadmium (Ni–Cd), nickel-metal hydride (Ni–MH) and lithium-ion. Mercury batteries of this format, once common, have been banned in many countries due to their toxicity. Designations for this format include NEDA 1604 and IEC 6F22 (for zinc-carbon) or MN1604 6LR61 (for alkaline). The size, regardless of chemistry, is commonly designated PP3—a designation originally reserved solely for carbon-zinc, or in some countries, E or E-block. A range of PP batteries was produced in the past, with voltages of 4.5, 6, and 9 volts and different capacities; the larger 9-volt PP6, PP7, and PP9 are still available. A few other 9-volt battery sizes are available: A10 and A29.
Most PP3-size alkaline batteries are constructed of six in
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https://en.wikipedia.org/wiki/Caleb%20Gattegno
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Caleb Gattegno (1911–1988) was an Egyptian educator, psychologist, and mathematician. He is considered one of the most influential and prolific mathematics educators of the twentieth century. He is best known for introducing new approaches to teaching and learning mathematics (Visible & Tangible Math), foreign languages (The Silent Way) and reading (Words in Color). Gattegno also developed pedagogical materials for each of these approaches, and was the author of more than 120 books and hundreds of articles largely on the topics of education and human development.
Background
Gattegno was born November 11, 1911, in Alexandria, Egypt. His parents, Menachem Gattegno, a Spanish merchant, and his wife, Bchora, had nine children. Because of poverty, Gattegno and his siblings had to work starting from a young age. The future mathematician had no formal education until he started to learn on his own at the age of 14. He took external examinations when he was 20 years old and obtained a teaching license in physics and chemistry from the University of Marseille in Cairo.
He moved to England, where he became involved in teacher education and helped establish the Association of Teachers of Mathematics and the International Commission for the Study and Improvement of Mathematics Teaching. He taught at several universities including the University of Liverpool and the University of London.
Pedagogical approach
Gattegno's pedagogical approach is characterised by propositions based on the
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https://en.wikipedia.org/wiki/IMSL%20Numerical%20Libraries
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IMSL (International Mathematics and Statistics Library) is a commercial collection of software libraries of numerical analysis functionality that are implemented in the computer programming languages C, Java, C#.NET, and Fortran. A Python interface is also available.
The IMSL Libraries were developed by Visual Numerics, which was acquired in 2009 by Rogue Wave Software, which was acquired in 2019 by Minneapolis, Minnesotabased application software developer Perforce.
Version history
The first IMSL Library for the Fortran language was released in 1970, followed by a C-language version originally called C/Base in 1991, a Java-language version in 2002 and the C#-language version in 2004.
Several recent product releases have involved making IMSL Library functions available from Python. These releases are Python wrappers to IMSL C Library functions (PyIMSL wrappers) and PyIMSL Studio, a prototyping and production application development environment based on Python and the IMSL C Library. The PyIMSL wrappers were first released in August 2008. PyIMSL Studio was introduced in February 2009. PyIMSL Studio is available for download at no charge for non-commercial use or for commercial evaluation.
Current versions:
IMSL C Library V 8.0 – November 2011
IMSL C# Library V 6.5.2 – November 2015 (end of life announced as end of 2020)
IMSL Fortran Library V 7.0 – October 2010
PyIMSL Studio V 1.5 – August 2009
PyIMSL wrappers V 1.5 – August 2009
JMSL Library V 6.1 – August 2010
Platf
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https://en.wikipedia.org/wiki/Thomas%20Parnell%20%28scientist%29
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Thomas Parnell (5 July 1881 – 1 September 1948) was the first Professor of Physics at the University of Queensland. He started the famous pitch drop experiment there.
Education
Thomas Parnell was born in West Haddon, Northamptonshire, England and died in Indooroopilly in Brisbane, Australia. He was educated at St John's College, Cambridge, after winning a scholarship and received his B.A. in 1903. He received his M.A. from Cambridge in 1908.
Career
Parnell took up a tutoring position at Trinity College, at the University of Melbourne, between 1904 and 1911, with the hope that it would enable him to have time to pursue research, and then apply for a Fellowship position at the Cambridge. However his teaching duties in physics, mathematics and chemistry were so numerous, that he never had the time to dedicate to research. He elected to move to Brisbane with friend and future wife, Hermiene Ulrich, also a lecturer at the newly established University of Queensland. He lectured in physics at the University of Queensland between 1911 and 1918, and was a professor between 1919 and 1948.
He enlisted in World War I as a private in the Australian Imperial Force in 1917, after having been in the Volunteers in England. He served as a gunner, often under the orders of his former students. He refunded his excess pay during the War, back to the University, to assist ex-servicemen planning on undertaking study. His wife, Hermiene returned to lecturing work during World War I, to assist t
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https://en.wikipedia.org/wiki/William%20Gehrlein
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William V. Gehrlein (born 1946) is a notable researcher in the areas of social choice theory, decision theory and graph theory. He received his B.S. in physics from Gannon College in Erie, Pennsylvania, in 1968, his M.S. in physics from Pennsylvania State University in 1972, and his Ph.D. in business administration from Pennsylvania State University in 1975. His teaching interests are operations management and operations research. He is currently professor of business administration at the University of Delaware.
Notes
1946 births
Living people
University of Delaware faculty
American operations researchers
Eberly College of Science alumni
Gannon University alumni
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https://en.wikipedia.org/wiki/Trimer
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Trimer may refer to:
Trimer (chemistry), a reaction product composed of three identical molecules
Protein trimer, a compound of three macromolecules non-covalently bound
Efimov trimer, a weakly bound quantum mechanical state of three identical particles
Trimer, Ille-et-Vilaine, a commune in France
See also
Trimery (botany), having three parts in a distinct whorl of a plant structure
Trimerus, Latin name of the Isole Tremiti, Italy
tri, a prefix
-mer, an affix
Trimmer (disambiguation)
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https://en.wikipedia.org/wiki/Let%27s%20Get%20Together%20Now
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Let's Get Together Now is the official local song of the 2002 FIFA World Cup held in South Korea and Japan. Performed by the Supergroup Voice of Korea/Japan (Lena Park and Brown Eyes from South Korea and Sowelu and Chemistry from Japan), it was released in three separate versions: a full Japanese version, a full Korean version (with some English at the end), and a merged version which combines the lyrics of the two versions. The last of the three was included in the official soundtrack album and was performed in the opening ceremonies in Seoul on May 31, 2002.
Composed by Daisuke Kawaguchi and Kim Hyung-Suk and written by Yoshimitsu Sawamoto, Kiyoshi Matsuo, Park, and Kim, the lyrics tell spirit of gathering and coming together as one, as with the theme of the two countries in co-hosting the said event. Although this is not the official theme song (which is Boom by Anastacia), this song proves to be popular.
The single was certified gold by the RIAJ in March 2002.
See also
List of FIFA World Cup songs and anthems
The Official Album of the 2002 FIFA World Cup
References
External links
Voice of Korea/Japan - "Let's Get Together Now" (2002 FIFA World Cup Opening Ceremony)
"Let's Get Together Now" Korean & Japanese Version
"Let's Get Together Now" Korean Version
"Let's Get Together Now" Japanese Version
South Korean songs
Japanese songs
2002 FIFA World Cup
FIFA World Cup official songs and anthems
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https://en.wikipedia.org/wiki/Harriet%20Creighton
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Harriet Baldwin Creighton (27 June 1909 – January 9, 2004) was an American botanist, geneticist and educator.
Background
Born in Delavan, Illinois, Creighton graduated from Wellesley College in 1929, and went on to complete her Ph.D. at Cornell University in 1933.
Career
During her time at Cornell she worked in the field of maize cytogenetics with Barbara McClintock, the pair published a very influential paper in 1931 in which they described chromosomal crossover for the first time. This paper, part of her Ph.D. research, provided key evidence that chromosomes carried and exchanged genetic information and hence that genes for physical traits are carried on chromosomes. Barbara McClintock guided her Ph.D. research.
After completing her Ph.D. she taught at Cornell University and Connecticut College, and then returned to Wellesley College where she taught until her retirement in 1974; taking time from her career to serve in the U.S. Navy during World War II.
Creighton was elected in 1940 a fellow of the American Association for the Advancement of Science. In 1956 she was elected president of the Botanical Society of America.
Key Publication
.
References
External links
Wellesley Wire: "Harriet Creighton, long-time professor of botany, dies" (January 29, 2004);
**Kass, Lee B. 2005c, Plant Science Bulletin: "Harriet B. Creighton: Proud botanist" 51(4): 118–125. Available online, December 2005:
Kass, Lee B. 2007a. "Women Pioneers in Plant Biology" - Barbara McClintock
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https://en.wikipedia.org/wiki/Q%20value%20%28nuclear%20science%29
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In nuclear physics and chemistry, the value for a reaction is the amount of energy absorbed or released during the nuclear reaction. The value relates to the enthalpy of a chemical reaction or the energy of radioactive decay products. It can be determined from the masses of reactants and products. values affect reaction rates. In general, the larger the positive value for the reaction, the faster the reaction proceeds, and the more likely the reaction is to "favor" the products.
where the masses are in atomic mass units. Also, both and are the sums of the reactant and product masses respectively.
Definition
The conservation of energy, between the initial and final energy of a nuclear process enables the general definition of based on the mass–energy equivalence. For any radioactive particle decay, the kinetic energy difference will be given by:
where denotes the kinetic energy of the mass .
A reaction with a positive value is exothermic, i.e. has a net release of energy, since the kinetic energy of the final state is greater than the kinetic energy of the initial state.
A reaction with a negative value is endothermic, i.e. requires a net energy input, since the kinetic energy of the final state is less than the kinetic energy of the initial state. Observe that a chemical reaction is exothermic when it has a negative enthalpy of reaction, in contrast a positive value in a nuclear reaction.
The value can also be expressed in terms of the Mass exces
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https://en.wikipedia.org/wiki/Louisa%20Gross%20Horwitz%20Prize
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The Louisa Gross Horwitz Prize for Biology or Biochemistry is an annual prize awarded by Columbia University to a researcher or group of researchers who have made an outstanding contribution in basic research in the fields of biology or biochemistry.
The prize was established at the bequest of S. Gross Horwitz and is named to honor his mother, Louisa Gross Horwitz, the daughter of trauma surgeon Samuel D. Gross. The prize was first awarded in 1967.
As of October 2018, 51 (50%) of the 101 prize recipients have subsequently been awarded the Nobel Prize in Physiology or Medicine (40) or Chemistry (11). It is regarded as one of the important precursors of a future Nobel Prize award.
Recipients
1967 Luis Leloir (1970 Chemistry)
1968 Har Gobind Khorana (1968 Physiology or Medicine), Marshall Warren Nirenberg (1968 Physiology or Medicine)
1969 Max Delbrück (1969 Physiology or Medicine), Salvador E. Luria (1969 Physiology or Medicine)
1970 Albert Claude (1974 Physiology or Medicine), George E. Palade (1974 Physiology or Medicine), Keith R. Porter
1971 Hugh E. Huxley
1972 Stephen W. Kuffler
1973 Renato Dulbecco (1975 Physiology or Medicine), Harry Eagle, Theodore T. Puck
1974 Boris Ephrussi
1975 K. Sune D. Bergstrom (1982 Physiology or Medicine), Bengt Samuelsson (1982 Physiology or Medicine)
1976 Seymour Benzer, Charles Yanofsky
1977 Michael Heidelberger, Elvin A. Kabat, Henry G. Kunkel
1978 David Hubel (1981 Physiology of Medicine), Vernon Mountcastle, Torsten Wiesel (1981 Physio
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https://en.wikipedia.org/wiki/George%20Placzek
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George Placzek (; September 26, 1905 – October 9, 1955) was a Moravian physicist.
Biography
Placzek was born into a wealthy Jewish family in Brünn, Moravia (now Brno, Czech Republic), the grandson of Chief Rabbi Baruch Placzek. He studied physics in Prague and Vienna.
In the 1930s, Placzek was known as an adventurous person with sharp sense of humor, a tireless generator of novel physics ideas which he generously shared with his colleagues. The scope of Placzek's pilgrimage around the world's physics centres in the 1930s was unique among his colleagues. He worked with Hans Bethe, Edward Teller, Rudolf Peierls, Werner Heisenberg, Victor Weisskopf, Enrico Fermi, Niels Bohr, Lev Landau, Edoardo Amaldi, Emilio Segrè, Otto Frisch, Leon van Hove, and many other prominent physicists of his time. His wife, Els Placzek () was an ex-wife of physicist Hans von Halban. He lost all his relatives to Holocaust, casting a tragic shadow on his life.
Placzek's major areas of scientific work involved a fundamental theory of Raman scattering, molecular spectroscopy in gases and liquids, neutron physics and mathematical physics. Together with Otto Frisch, he suggested a direct experimental proof of nuclear fission. Together with Niels Bohr and others, he was instrumental in clarifying the role of Uranium 235 for the possibility of nuclear chain reaction.
During his stay in Landau's circle in Kharkiv around 1937, Placzek witnessed the brutal reality of Joseph Stalin's regime. His first-hand e
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https://en.wikipedia.org/wiki/Randall%20Division%20of%20Cell%20and%20Molecular%20Biophysics
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The Randall Division of Cell and Molecular Biophysics (the Randall) is a research institute of King's College London located in London United Kingdom. It is a centre for study in allergy and asthma; muscle signalling and development; structural biology; muscle biophysics; cell motility and cytoskeleton, and cell imaging.
The Randall continues the tradition of Biophysics at King's established by Sir John Randall, which produced the studies of the structure of DNA by Rosalind Franklin and Maurice Wilkins. Much of this early work was supported by the Medical Research Council, who still provide the majority of research funding.
The Biophysics Unit expanded and in the 1960s moved to the site in Drury Lane that later became known as the Randall Institute, incorporating at various stages the King's Biophysics Department, MRC Cell Biophysics Unit, and MRC Muscle and Motility Unit. After King's merged with the Guy's and St Thomas’ Medical Schools in 1998, the Randall Institute research groups moved to new labs on the Guy's Campus at London Bridge, which became the present Randall Division of Cell and Molecular Biophysics.
References
External links
The Randall Division of Cell and Molecular Biophysics
Biological research institutes in the United Kingdom
Biophysics organizations
Genetics in the United Kingdom
History of genetics
King's College London
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https://en.wikipedia.org/wiki/Squeezed
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Squeezed may refer to:
Squeezed (film), a 2007 Australian documentary
Squeezed (EP), an EP by What Is This?
Squeezed, an album by Orange Range
Compression (physical)
See also
Squeezed coherent state, in physics, a state of the quantum mechanical Hilbert space
Squeeze (disambiguation)
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https://en.wikipedia.org/wiki/Geometry%20%26%20Topology
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Geometry & Topology is a peer-refereed, international mathematics research journal devoted to geometry and topology, and their applications. It is currently based at the University of Warwick, United Kingdom, and published by Mathematical Sciences Publishers, a nonprofit academic publishing organisation.
It was founded in 1997 by a group of topologists who were dissatisfied with recent substantial rises in subscription prices of journals published by major publishing corporations. The aim was to set up a high-quality journal, capable of competing with existing journals, but with substantially lower subscription fees. The journal was open-access for its first ten years of existence and was available free to individual users, although institutions were required to pay modest subscription fees for both online access and for printed volumes. At present, an online subscription is required to view full-text PDF copies of articles in the most recent three volumes; articles older than that are open-access, at which point copies of the published articles are uploaded to the arXiv. A traditional printed version is also published, at present on an annual basis.
The journal has grown to be well respected in its field, and has in recent years published a number of important papers, in particular proofs of the Property P conjecture and the Birman conjecture.
References
Walter Neumann on the Success of Geometry & Topology, May 2010, Sciencewatch.com, Thomson Reuters
External link
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https://en.wikipedia.org/wiki/Coffman%20Memorial%20Union
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Coffman Memorial Union (commonly known as Coffman Union or simply Coffman) is a student union on the East Bank campus of the University of Minnesota in Minneapolis. Situated near the Mississippi River, Coffman anchors the south end of Northrop Mall, a grassy area at the center of campus that is bordered by the university's physics, mathematics, chemistry, and administration buildings, plus Walter Library. Northrop Auditorium sits at the north end of the mall, opposite Coffman across Washington Avenue.
History
Coffman Memorial Union was built between 1939 and 1940 as a new "center of social life" for the University of Minnesota campus, a role that had previously been filled by Shevlin Hall and Nicholson Hall in the Old Campus Historic District. Designed by architect Clarence H. Johnston Jr, the new building opened in September 1940 and was dedicated on October 25 of the same year. It was named in memory of Lotus D. Coffman, President of the University of Minnesota between 1920 and 1938.
Since opening, the building has undergone two significant renovations. The first major renovation, completed in 1976, was widely criticized for its adverse effect on the building's exterior. However, this was largely corrected between 1999 and 2003 during the second major renovation. The second renovation restored the exterior, thoroughly renovated the interior, and greatly expanded the basement floors to include the main University of Minnesota Bookstore, food vendors, offices, lounges, and
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https://en.wikipedia.org/wiki/Envelope%20%28motion%29
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In mechanical engineering, an envelope is a solid representing all positions which may be occupied by an object during its normal range of motion.
Another (jargon) word for this is a "flop".
Wheel envelope
In automobile design, a wheel envelope may be used to model all positions a wheel and tire combo may be expected to occupy during driving. This will take into account the maximum jounce and rebound allowed by the suspension system and the maximum turn and tilt allowed by the steering mechanism. Minimum and maximum tire inflation pressures and wear conditions may also be considered when generating the envelope.
This envelope is then compared with the wheel housing and other components in the area to perform an interference/collision analysis. The results of this analysis tell the engineers whether that wheel/tire combo will strike the housing and components under normal driving conditions. If so, either a redesign is in order, or that wheel/tire combo will not be recommended.
A different wheel envelope must be generated for each wheel/tire combo for which the vehicle is rated. Much of this analysis is done using CAD/CAE systems running on computers. Of course, high speed collisions, during an accident, are not considered "normal driving conditions", so the wheel and tire may very well contact other parts of the vehicle at that time.
Robot's working envelope
In robotics, the working envelope or work area is the volume of working or reaching space. Some factors of a
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https://en.wikipedia.org/wiki/Simon%20S.%20Lam
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Simon S. Lam is an American computer scientist. He retired in 2018 from The University of Texas at Austin as Professor Emeritus and Regents' Chair Emeritus in Computer Science #1. He made seminal and important contributions to transport layer security, packet network verification, as well as network protocol design, verification, and performance analysis.
Simon Lam pioneered security for Internet applications - for example, one result of his work that is visible to most users as the "s" in https, signifying a secure connection. He invented secure sockets in 1991. In 1993, he invented the Secure Network Programming (SNP) application programming interface (API) which explored the approach of having a secure transport layer API closely resembling Berkeley sockets, to facilitate retrofitting pre-existing network applications with security measures. This work was done when WWW was still in its infancy. SNP was published and presented on June 8, 1994 at the USENIX Summer Technical Conference. Subsequent secure sockets layers (SSL and TLS) re-implemented several years later using the architecture and key ideas first presented in SNP, enabled secure e-commerce on WWW (e.g., banking, shopping). TLS is also widely used to secure email and many other Internet applications.
For this contribution, Professor Lam and three graduate students in his research project won the 2004 ACM Software System Award. He was elected to the United States National Academy of Engineering in 2007. He was
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https://en.wikipedia.org/wiki/Preset
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Preset may refer to:
Default (computer science), a setting or value automatically assigned to a software application, computer program, etc.
Preset (electronics), a variable component on a device only accessible to manufacturing or maintenance personnel
Pre-programmed setting on various electronic products and musical instruments, including:
Combination action on pipe organ
Preset button (tuner) - station selectors on the tuner of radio receiver and television set
Preset key (Hammond organ) - inverse color keys on Hammond organs, to recall pre-programmed tonewheel settings
Preset rhythm - pre-programmed rhythm-pattern on drum machine
Synthesizer patch stored a pre-programmed tone
Mathematics
Pre-ordered set
Music
The Presets - a Sydney-based Australian duo, consisting of Julian Hamilton and Kim Moyes
Schools
Preset Pacesetters Institute, a private boarding Senior High school in Madina, Ghana
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https://en.wikipedia.org/wiki/Axolemma
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In neuroscience, the axolemma (, and 'axo-' from axon) is the cell membrane of an axon, the branch of a neuron through which signals (action potentials) are transmitted. The axolemma is a three-layered, bilipid membrane. Under standard electron microscope preparations, the structure is approximately 8 nanometers thick.
Composition
The skeletal framework of this structure is formed by a spectrum of hexagonal or pentagonal arrangement on the inside of the cell membrane, as well as actin connected to the transmembrane. The metric cellular matrix is bound by transmembrane proteins, including the β1-integrin, to the cytoskeleton via the membrane skeleton. The axolemma is a phospholipid bilayer membrane, and charged ions/particles cannot directly pass through it. Instead, transmembrane proteins, such as specialized energy dependent ion pumps (the sodium/potassium pump), and ion channels (ligand-gated channels, mechanically gated channels, voltage-gated channels, and leakage channels) that sit within the axolemma are required to assist these charged ions/particles across the membrane, and to generate transmembrane potentials that will generate an action potential.
Function
The primary responsibility of cell membranes, including those surrounding the axon, is to regulate what goes into the cell and what goes out of the cell. The axolemma plays an important role in the nervous system, specifically the sensation, integration, and response pathways within the nervous system. Communi
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https://en.wikipedia.org/wiki/Passive%20data%20structure
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In computer science and object-oriented programming, a passive data structure (PDS), also termed a plain old data structure or plain old data (POD), is a record, in contrast with objects. It is a data structure that is represented only as passive collections of field values (instance variables), without using object-oriented features.
Rationale
Passive data structures are appropriate when there is a part of a system where it should be clearly indicated that the detailed logic for data manipulation and integrity are elsewhere. PDSs are often found at the boundaries of a system, where information is being moved to and from other systems or persistent storage and the problem domain logic that is found in other parts of the system is irrelevant. For example, PDS would be convenient for representing the field values of objects that are being constructed from external data, in a part of the system where the semantic checks and interpretations needed for valid objects are not applied yet.
In C++
A PDS type in C++, or Plain Old C++ Object, is defined as either a scalar type or a PDS class. A PDS class has no user-defined copy assignment operator, no user-defined destructor, and no non-static data members that are not themselves PDS. Moreover, a PDS class must be an aggregate, meaning it has no user-declared constructors, no private nor protected non-static data, no virtual base classes and no virtual functions. The standard includes statements about how PDS must behave in C++. The
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https://en.wikipedia.org/wiki/Bleb
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Bleb may refer to:
Bleb (cell biology), an irregular bulge in the plasma membrane of a cell
Bleb (medicine), a large blister filled with serous fluid, or jargon for an outpouching of any kind, from a vessel (see Aneurysm), or an air pocket in the lungs (see Focal lung pneumatosis)
Bleb (mineralogy), a small bubble-like inclusion of one mineral within a larger mineral
Bleb, a book of poetry written by B-52's frontman Fred Schneider
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https://en.wikipedia.org/wiki/Christina%20Chambers
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Christina Chambers (born October 24, 1969) is an American actress and model.
Personal life
Chambers was born in Alexandria, Virginia, into a family of academics, both parents holding doctorates (her father's in physics and her mother's in mathematics). She is the next-to-youngest of four siblings. Chambers admits to being a tomboy at heart, and has never been very interested in her appearance. Her mother informed her at the age of six when she made her first acting debut that she looked petrified. However, Chambers says she always knew that she'd become an actress.
Career
She studied Shakespeare at The Catholic University of America in Washington, D.C., and spent a semester in Stratford on Avon studying with the Royal Shakespeare Company, where she played the character Goneril in King Lear. After joining the Shenandoah Shakespeare Express she went on tour and played Juliet in Romeo & Juliet.
After leaving the tour, while in New York City, that she took the big step away from Shakespeare. Chambers was spotted by a New York commercial agency who quickly signed her up, and by pure accident ended up signing with a New York modeling agent too. However, it was not until she met her acting agent Peter (who has agencies in New York and Los Angeles) during a New York showcase that her acting career started to accelerate.
Chambers became best known to soap fans as Maria Torres on the NBC soap opera Sunset Beach from 1998 to 1999.
In 2001 Chambers was cast on MTV's first and only s
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https://en.wikipedia.org/wiki/Majorization
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In mathematics, majorization is a preorder on vectors of real numbers. Let denote the -th largest element of the vector . Given , we say that weakly majorizes (or dominates) from below (or equivalently, we say that is weakly majorized (or dominated) by from below) denoted as if for all . If in addition , we say that majorizes (or dominates) , written as , or equivalently, we say that is majorized (or dominated) by . The order of the entries of the vectors or does not affect the majorization, e.g., the statement is simply equivalent to . As a consequence, majorization is not a partial order, since and do not imply , it only implies that the components of each vector are equal, but not necessarily in the same order.
The majorization partial order on finite dimensional vectors, described here, can be generalized to the Lorenz ordering, a partial order on distribution functions. For example, a wealth distribution is Lorenz-greater than another if its Lorenz curve lies below the other. As such, a Lorenz-greater wealth distribution has a higher Gini coefficient, and has more income disparity. Various other generalizations of majorization are discussed in chapters 14 and 15 of.
The majorization preorder can be naturally extended to density matrices in the context of quantum information. In particular, exactly when (where denotes the state's spectrum).
Examples
(Strong) majorization: . For vectors with components
(Weak) majorization: . For vectors with compon
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https://en.wikipedia.org/wiki/Bruce%20Allen%20%28physicist%29
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Bruce Allen (born May 11, 1959) is an American physicist and director of the Max Planck Institute for Gravitational Physics in Hannover Germany and leader of the Einstein@Home project for the LIGO Scientific Collaboration. He is also a physics professor at the University of Wisconsin–Milwaukee and the initiator / project leader of smartmontools hard disk utility.
He has done research work on models of the very early universe (inflationary cosmology, cosmic strings). Allen currently leads a research group working on the detection of gravitational waves. In this role, he was one of the first scientists to become aware of the initial detection of GW150914 at LIGO, in September 2015. Allen's research work has been funded by the US National Science Foundation since 1987.
Education and positions
1976 Graduated from Wayland High School, Wayland, Massachusetts, US (Allen belonged to the class of 1977, but graduated a year early with the class of 1976).
1980 BS in physics, Massachusetts Institute of Technology (advisor: Rainer Weiss)
1984 PhD in gravitation and cosmology, University of Cambridge, England (advisor: Stephen Hawking)
1983–1985 Postdoctoral fellow, University of California Santa Barbara (Physics Department, advisors James Hartle and Gary Horowitz)
1985–1986 Postdoctoral fellow, Tufts University (physics department, advisors Alex Vilenkin and Larry Ford)
1986–1987 Chercheur Associé, Observatoire de Paris – Meudon, France (advisors Brandon Carter and Thibault Damour)
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https://en.wikipedia.org/wiki/Stephen%20Shenker
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Stephen Hart Shenker (born 1953) is an American theoretical physicist who works on string theory. He is a professor at Stanford University and former director of the Stanford Institute for Theoretical Physics. His brother Scott Shenker is a computer scientist.
Work
Shenker's contributions to physics include:
Basic results on the phase structure of gauge theories (with Eduardo Fradkin)
Basic results on two dimensional conformal field theory and its relation to string theory (with Daniel Friedan, Emil Martinec, Zongan Qiu, and others)
The nonperturbative formulation of matrix models of low-dimensional string theory, the first nonperturbative definitions of string theory (with Michael R. Douglas)
The discovery of distinctively stringy nonperturbative effects in string theory, later understood to be caused by D-branes. These effects play a major role in string dynamics
The discovery of Matrix Theory, the first nonperturbative definition of String/M theory in a physical number of dimensions. Matrix Theory (see Matrix string theory) is an example of a gauge/gravity duality and is now understood to be a special case of the AdS/CFT correspondence (with Tom Banks, Willy Fischler and Leonard Susskind)
Basic results on the connection between quantum gravity and quantum chaos (with Douglas Stanford, Juan Maldacena and others)
Selected works
References
External links
home page of Stephen Shenker at Stanford
home page of Stanford Institute for Theoretical Physics
Living pe
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https://en.wikipedia.org/wiki/Willy%20Fischler
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Willy Fischler (born 1949 in Antwerp, Belgium) is a theoretical physicist. He is the Jane and Roland Blumberg Centennial Professor of Physics at the University of Texas at Austin, where he is affiliated with the Weinberg theory group. He is also a certified Flight Paramedic (FP-C) and was a Licensed Paramedic with Marble Falls Area EMS and a volunteer EMT with the Westlake Fire Department.
His contributions to physics include:
Early computation of the force between heavy quarks.
The DFSZ (Dine–Fischler–Srednicki–Zhitnisky) model, as a solution to the strong CP problem.
The cosmological effects of the invisible axion (with Michael Dine) and its role as a candidate for dark matter.
Pioneering work (with Michael Dine and Mark Srednicki) on the use of supersymmetry to solve outstanding problems in the standard model of particle physics.
The first formulation of what became known as the "moduli problem in cosmology" (with G.D. Coughlan, Edward Kolb, Stuart Raby and Graham Ross).
The Fischler–Susskind mechanism in string theory (with Leonard Susskind).
The original formulation of the holographic entropy bound in the context of cosmology (with Leonard Susskind).
The discovery of M(atrix) theory, or BFSS Matrix Theory. M(atrix) theory is an example of a gauge/gravity duality (with Tom Banks, Steve Shenker and Leonard Susskind).
Black Hole production in colliders (with Tom Banks).
References
External links
Prof. Fischler's homepage
Medic
MFAEMS
Belgian physicists
String
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https://en.wikipedia.org/wiki/E-folding
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In science, e-folding is the time interval in which an exponentially growing quantity increases by a factor of e; it is the base-e analog of doubling time. This term is often used in many areas of science, such as in atmospheric chemistry, medicine and theoretical physics, especially when cosmic inflation is investigated. Physicists and chemists often talk about the e-folding time scale that is determined by the proper time in which the length of a patch of space or spacetime increases by the factor e mentioned above.
In finance, the logarithmic return or continuously compounded return, also known as force of interest, is the reciprocal of the e-folding time.
The term e-folding time is also sometimes used similarly in the case of exponential decay, to refer to the timescale for a quantity to decrease to 1/e of its previous value.
The process of evolving to equilibrium is often characterized by a time scale called the e-folding time, τ. This time is used for processes which evolve exponentially toward a final state (equilibrium). In other words, if we examine an observable, X, associated with a system, (temperature or density, for example) then after a time, τ, the initial difference between the initial value of the observable and the equilibrium value, ΔXi, will have decreased to ΔXi /e where the number e ≈ 2.71828.
Te e-folding time
N(t) amount at time t
N(0) initial amount
Td doubling time
ln(2) ≈ 0.693 natural logarithm of 2
r% growth rate in time t
Example of l
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https://en.wikipedia.org/wiki/Hydrazide
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Hydrazides in organic chemistry are a class of organic compounds with the formula where R is acyl (), sulfonyl (), phosphoryl (), phosphonyl () and similar groups (chalcogen analogs are included, for example sulfur analogs called thiohydrazides), and R' are any groups (tipically hydrogen or organyl). Unlike hydrazine and alkylhydrazines, hydrazides are nonbasic owing to the inductive influence of the acyl, sulfonyl, or phosphoryl substituent.
Sulfonyl hydrazides
A common sulfonyl hydrazide is p-toluenesulfonyl hydrazide, a white air-stable solid. They are also widely used as organic reagents.
Toluenesulfonyl hydrazide is used to generate toluenesulfonyl hydrazones. When derived from ketones, these hydrazones participate in the Shapiro reaction and the Eschenmoser–Tanabe fragmentation.
2,4,6-Triisopropylbenzenesulfonylhydrazide is a useful source of diimide.
Acyl hydrazides
Acylhydrazines are derivatives of carboxylic acids, although they are typically prepared by the reaction of esters with hydrazine:
Use
An applied example is a synthesis of sunitinib begins by mixing 5-fluoroisatin slowly into hydrazine hydrate. After 4 hours at 110 °C, the indole ring structure has been broken into (2-amino-5-fluoro-phenyl)-acetic acid hydrazide with reduction of the ketone at the 3-position. Subsequent annelation in strong acid creates the 1,3-dihydro-2-oxo indole structure required for the drug.
Uses
1.) Hydrazide analogs has biological activities like antidepressant, anticonvul
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https://en.wikipedia.org/wiki/Fermi%E2%80%93Pasta%E2%80%93Ulam%E2%80%93Tsingou%20problem
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In physics, the Fermi–Pasta–Ulam–Tsingou (FPUT) problem or formerly the Fermi–Pasta–Ulam problem was the apparent paradox in chaos theory that many complicated enough physical systems exhibited almost exactly periodic behavior – called Fermi–Pasta–Ulam–Tsingou recurrence (or Fermi–Pasta–Ulam recurrence) – instead of the expected ergodic behavior. This came as a surprise, as Enrico Fermi, certainly, expected the system to thermalize in a fairly short time. That is, it was expected for all vibrational modes to eventually appear with equal strength, as per the equipartition theorem, or, more generally, the ergodic hypothesis. Yet here was a system that appeared to evade the ergodic hypothesis. Although the recurrence is easily observed, it eventually became apparent that over much, much longer time periods, the system does eventually thermalize. Multiple competing theories have been proposed to explain the behavior of the system, and it remains a topic of active research.
The original intent was to find a physics problem worthy of numerical simulation on the then-new MANIAC computer. Fermi felt that thermalization would pose such a challenge. As such, it represents one of the earliest uses of digital computers in mathematical research; simultaneously, the unexpected results launched the study of nonlinear systems.
The FPUT experiment
In the summer of 1953 Enrico Fermi, John Pasta, Stanislaw Ulam, and Mary Tsingou conducted computer simulations of a vibrating string that inclu
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https://en.wikipedia.org/wiki/Schr%C3%B6dinger%20functional
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In mathematical physics, some approaches to quantum field theory are more popular than others. For historical reasons, the Schrödinger representation is less favored than Fock space methods. In the early days of quantum field theory, maintaining symmetries such as Lorentz invariance, displaying them manifestly, and proving renormalisation were of paramount importance. The Schrödinger representation is not manifestly Lorentz invariant and its renormalisability was only shown as recently as the 1980s by Kurt Symanzik (1981).
The Schrödinger functional is, in its most basic form, the time translation generator of state wavefunctionals. In layman's terms, it defines how a system of quantum particles evolves through time and what the subsequent systems look like.
Background
Quantum mechanics is defined over the spatial coordinates upon which the Galilean group acts, and the corresponding operators act on its state as . The state is characterized by a wave function obtained by projecting it onto the coordinate eigenstates defined by . These eigenstates are not stationary. Time evolution is generated by the Hamiltonian, yielding the Schrödinger equation .
However, in quantum field theory, the coordinate is the field operator , which acts on the state's wave functional as
where "" indicates an unbound spatial argument. This wave functional
is obtained by means of the field eigenstates
which are indexed by unapplied "classical field" configurations . These eigenstates,
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https://en.wikipedia.org/wiki/Hamiltonian%20lattice%20gauge%20theory
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In physics, Hamiltonian lattice gauge theory is a calculational approach to gauge theory and a special case of lattice gauge theory in which the space is discretized but time is not. The Hamiltonian is then re-expressed as a function of degrees of freedom defined on a d-dimensional lattice.
Following Wilson, the spatial components of the vector potential are replaced with Wilson lines over the edges, but the time component is associated with the vertices. However, the temporal gauge is often employed, setting the electric potential to zero. The eigenvalues of the Wilson line operators U(e) (where e is the (oriented) edge in question) take on values on the Lie group G. It is assumed that G is compact, otherwise we run into many problems. The conjugate operator to U(e) is the electric field E(e) whose eigenvalues take on values in the Lie algebra . The Hamiltonian receives contributions coming from the plaquettes (the magnetic contribution) and contributions coming from the edges (the electric contribution).
Hamiltonian lattice gauge theory is exactly dual to a theory of spin networks. This involves using the Peter–Weyl theorem. In the spin network basis, the spin network states are eigenstates of the operator .
References
Lattice field theory
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https://en.wikipedia.org/wiki/Fusion%20rules
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In mathematics and theoretical physics, fusion rules are rules that determine the exact decomposition of the tensor product of two representations of a group into a direct sum of irreducible representations. The term is often used in the context of two-dimensional conformal field theory where the relevant group is generated by the Virasoro algebra, the relevant representations are the conformal families associated with a primary field and the tensor product is realized by operator product expansions. The fusion rules contain the information about the kind of families that appear on the right hand side of these OPEs, including the multiplicities.
More generally, integrable models in 2 dimensions which aren't conformal field theories are also described by fusion rules for their charges.
References
Conformal field theory
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https://en.wikipedia.org/wiki/Conformal%20family
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In theoretical physics, a conformal family is an irreducible representation of the Virasoro algebra. In most cases, it is uniquely determined by its primary field or the highest weight vector. The family contains all of its descendant fields.
References
See also
Conformal field theory
Conformal field theory
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https://en.wikipedia.org/wiki/Phosphoenolpyruvic%20acid
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Phosphoenolpyruvate (2-phosphoenolpyruvate, PEP) is the ester derived from the enol of pyruvate and phosphate. It exists as an anion. PEP is an important intermediate in biochemistry. It has the highest-energy phosphate bond found (−61.9 kJ/mol) in organisms, and is involved in glycolysis and gluconeogenesis. In plants, it is also involved in the biosynthesis of various aromatic compounds, and in carbon fixation; in bacteria, it is also used as the source of energy for the phosphotransferase system.
In glycolysis
PEP is formed by the action of the enzyme enolase on 2-phosphoglyceric acid. Metabolism of PEP to pyruvic acid by pyruvate kinase (PK) generates adenosine triphosphate (ATP) via substrate-level phosphorylation. ATP is one of the major currencies of chemical energy within cells.
In gluconeogenesis
PEP is formed from the decarboxylation of oxaloacetate and hydrolysis of one guanosine triphosphate molecule. This reaction is catalyzed by the enzyme phosphoenolpyruvate carboxykinase (PEPCK). This reaction is a rate-limiting step in gluconeogenesis:
GTP + oxaloacetate → GDP + phosphoenolpyruvate + CO2
Interactive pathway map
In plants
PEP may be used for the synthesis of chorismate through the shikimate pathway. Chorismate may then be metabolized into the aromatic amino acids (phenylalanine, tryptophan and tyrosine) and other aromatic compounds. The first step is when Phosphoenolpyruvate and erythrose-4-phosphate react to form 3-deoxy-D-arabinoheptulosonate-7-
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https://en.wikipedia.org/wiki/List%20of%20unsolved%20problems%20in%20chemistry
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This is a list of unsolved problems in chemistry. Problems in chemistry are considered unsolved when an expert in the field considers it unsolved or when several experts in the field disagree about a solution to a problem.
Physical chemistry problems
Can the transition temperature of high-temperature superconductors be brought up to room temperature?
How do the spin–orbit coupling, other relativistic corrections, and inter-electron effects modify the chemistry of the trans-actinides?
Is a lithium–air battery possible?
Organic chemistry problems
What is the origin of homochirality in biomolecules?
Why are accelerated kinetics observed for some organic reactions at the water-organic interface?
Do replacement reactions of aryl diazonium salts (dediazotizations) predominantly undergo SN1 or a radical mechanism?
Can an electrochemical cell reliably perform organic redox reactions?
Which "classic organic chemistry" reactions admit chiral catalysts?
Is it possible to construct a quaternary carbon atom with arbitrary (distinguishable) substituents and stereochemistry?
Can artificial enzymes replace the need for protecting groups when modifying sensitive compounds?
Inorganic chemistry problems
Are there any molecules that certainly contain a phi bond?
Is there a less labor- or energy-intensive technique for titanium refinement than the Kroll process?
Does nitrogen admit metastable allotropes under standard conditions?
Can new solvents or other techniques make dir
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https://en.wikipedia.org/wiki/Lorentz%20Eichstadt
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Lorentz Eichstadt (10 August 1596 – 8 June 1660) was a German mathematician and astronomer. He was a doctor of medicine in Szczecin in Pomerania and taught medicine and mathematics in Danzig.
The lunar crater Eichstadt is named after him.
References
External links
Lunar Republic: Craters. Retrieved October 8, 2005.
1596 births
1660 deaths
17th-century German mathematicians
17th-century German astronomers
17th-century German physicians
Scientists from Gdańsk
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https://en.wikipedia.org/wiki/Equipotential
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In mathematics and physics, an equipotential or isopotential refers to a region in space where every point is at the same potential. This usually refers to a scalar potential (in that case it is a level set of the potential), although it can also be applied to vector potentials. An equipotential of a scalar potential function in -dimensional space is typically an ()-dimensional space. The del operator illustrates the relationship between a vector field and its associated scalar potential field. An equipotential region might be referred as being 'of equipotential' or simply be called 'an equipotential'.
An equipotential region of a scalar potential in three-dimensional space is often an equipotential surface (or potential isosurface), but it can also be a three-dimensional mathematical solid in space. The gradient of the scalar potential (and hence also its opposite, as in the case of a vector field with an associated potential field) is everywhere perpendicular to the equipotential surface, and zero inside a three-dimensional equipotential region.
Electrical conductors offer an intuitive example. If a and b are any two points within or at the surface of a given conductor, and given there is no flow of charge being exchanged between the two points, then the potential difference is zero between the two points. Thus, an equipotential would contain both points a and b as they have the same potential. Extending this definition, an isopotential is the locus of all points that ar
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https://en.wikipedia.org/wiki/Molecular%20Biology%20%28journal%29
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Molecular Biology is a scientific journal which covers a wide scope of problems related to molecular, cell, and computational biology including genomics, proteomics, bioinformatics, molecular virology and immunology, molecular development biology, and molecular evolution. Molecular Biology publishes reviews, mini-reviews, experimental, and theoretical works, short communications and hypotheses. In addition, the journal publishes book reviews and meeting reports. The journal also publishes special issues devoted to most rapidly developing branches of physical-chemical biology and to the most outstanding scientists on the occasion of their anniversary birthdays. The journal is published in English and Russian versions by Nauka.
External links
Molecular and cellular biology journals
Multilingual journals
Publications with year of establishment missing
Nauka academic journals
English-language journals
Russian-language journals
Springer Science+Business Media academic journals
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https://en.wikipedia.org/wiki/Intrinsically%20disordered%20proteins
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In molecular biology, an intrinsically disordered protein (IDP) is a protein that lacks a fixed or ordered three-dimensional structure, typically in the absence of its macromolecular interaction partners, such as other proteins or RNA. IDPs range from fully unstructured to partially structured and include random coil, molten globule-like aggregates, or flexible linkers in large multi-domain proteins. They are sometimes considered as a separate class of proteins along with globular, fibrous and membrane proteins.
IDPs are a very large and functionally important class of proteins and their discovery has disproved the idea that three-dimensional structures of proteins must be fixed to accomplish their biological functions. For example, IDPs have been identified to participate in weak multivalent interactions that are highly cooperative and dynamic, lending them importance in DNA regulation and in cell signaling. Many IDPs can also adopt a fixed three-dimensional structure after binding to other macromolecules. Overall, IDPs are different from structured proteins in many ways and tend to have distinctive function, structure, sequence, interactions, evolution and regulation.
History
In the 1930s-1950s, the first protein structures were solved by protein crystallography. These early structures suggested that a fixed three-dimensional structure might be generally required to mediate biological functions of proteins. These publications solidified the central dogma of molecular bi
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https://en.wikipedia.org/wiki/SRH
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SRH may refer to:
Scottish Radio Holdings
Sexual and reproductive health
Shockley-Read-Hall recombination in solid-state physics
Socialist Republic of Croatia
Storm relative helicity in meteorology
Streatham Hill railway station, London, National Rail station code SRH
Sunrisers Hyderabad, an Indian cricket team
SRH Presents: Supporting Radical Habits, a 2005 compilation album
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https://en.wikipedia.org/wiki/Morse%20homology
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In mathematics, specifically in the field of differential topology, Morse homology is a homology theory defined for any smooth manifold. It is constructed using the smooth structure and an auxiliary metric on the manifold, but turns out to be topologically invariant, and is in fact isomorphic to singular homology. Morse homology also serves as a model for the various infinite-dimensional generalizations known as Floer homology theories.
Formal definition
Given any (compact) smooth manifold, let f be a Morse function and g a Riemannian metric on the manifold. (These are auxiliary; in the end, the Morse homology depends on neither.) The pair gives us a gradient vector field. We say that is Morse–Smale if the stable and unstable manifolds associated to all of the critical points of f intersect each other transversely.
For any such pair , it can be shown that the difference in index between any two critical points is equal to the dimension of the moduli space of gradient flows between those points. Thus there is a one-dimensional moduli space of flows between a critical point of index i and one of index . Each flow can be reparametrized by a one-dimensional translation in the domain. After modding out by these reparametrizations, the quotient space is zero-dimensional — that is, a collection of oriented points representing unparametrized flow lines.
A chain complex may then be defined as follows. The set of chains is the Z-module generated by the critical points. The di
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https://en.wikipedia.org/wiki/Anatoliy%20Skorokhod
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Anatoliy Volodymyrovych Skorokhod (; September 10, 1930January 3, 2011) was a Soviet and Ukrainian mathematician.
Skorokhod is well-known for a comprehensive treatise on the theory of stochastic processes, co-authored with Gikhman.
Career
Skorokhod worked at Kyiv University from 1956 to 1964. He was subsequently at the Institute of Mathematics of the National Academy of Sciences of Ukraine from 1964 until 2002. Since 1993, he had been a professor at Michigan State University in the US, and a member of the American Academy of Arts and Sciences.
He was an academician of the National Academy of Sciences of Ukraine from 1985 to his death in 2011.
His scientific works are on the theory of:
stochastic differential equations,
limit theorems of random processes,
distributions in infinite-dimensional spaces,
statistics of random processes and Markov processes.
Skorokhod authored over 450 scientific works, including more than 40 monographs and books.
Many terms and concepts have his name, including:
Skorokhod's embedding theorem
Skorokhod integral
Skorokhod's representation theorem
Skorokhod space
Skorokhod problem
Selected works
with I. I. Gikhman: Introduction to the theory of random processes, W. B. Saunders 1969, Dover 1996
with I. I. Gikhman: Stochastic Differential Equations, Springer Verlag 1972
with I. I. Gikhman: Controlled stochastic processes, Springer Verlag 1979
with I. I. Gikhman: The Theory of Stochastic Processes, Springer Verlag, 3 vols., 2004–2007
Ran
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https://en.wikipedia.org/wiki/Headwall
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In physical geography and geology, the headwall of a glacial cirque is its highest cliff. The term has been more broadly used to describe similar geomorphic features of non-glacial origin consisting of a concave depression with convergent slopes typically of 65 percent or greater forming the upper end of a drainage valley.
In civil engineering, a headwall is a small retaining wall placed at the inlet or outlet of a stormwater pipe or culvert.
In medicine, a headwall is the wall at the head end of a hospital bedspace. The bed abuts this headwall perpendicularly, which is furnished with equipment such as regulators for supplemental oxygen, regulators for suction, suction canisters, connections for the call bell system, lighting, electrical outlets, and often a vital signs monitor.
References
Glaciology
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https://en.wikipedia.org/wiki/American%20National%20Standards%20Institute%20Nanotechnology%20Panel
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The American National Standards Institute–Nanotechnology Standards Panel (ANSI-NSP) enables stakeholders in nanotechnology to work together to coordinate the development of voluntary standards. Such standards include terminology and materials properties and measurement procedures to facilitate commercialization of applications and uses of nanotechnology. ANSI established the panel in August 2004, and membership is open to all parties interested in nanotechnology standards.
Objectives
Objectives of the ANSI-NSP include:
Providing a forum to define needs, determine work plans and establish priorities for updating standards or creating new standards.
Soliciting participation from sectors that have not traditionally participated in the voluntary standards system.
Facilitating the development and adoption of standards in the area of nanotechnology in general and nomenclature/terminology specifically.
Making available the results of the panel's work.
External links
Nanotechnology institutions
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https://en.wikipedia.org/wiki/Smithsonian%20Conservation%20Biology%20Institute
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The Smithsonian Conservation Biology Institute (SCBI) is a unit of the Smithsonian Institution located on a campus located just outside the town of Front Royal, Virginia. An extension of the National Zoo in Washington, D.C., the SCBI has played a leading role in the fields of veterinary medicine, reproductive physiology and conservation biology since its founding in 1974.
Previously named the Conservation and Research Center, the CRC became known as the Smithsonian Conservation Biology Institute in 2010 as a symbol of its growing independence from the captive animals associated with the traditional images of zoos.
History
The land on which the SCBI lies has a history dating back to 1909, when the United States Army leased some 42 area farms. In the years predating World War I, the land served as a series of U.S. Army Remount Service depots, supplying horses and mules to the military. The federal government ultimately purchased the land in 1911 and began construction on the Ayleshire Quartermaster Remount Depot. Completed in 1916, the Depot consisted of eleven barn and stable facilities, hundreds of miles of split-rail fencing, many miles of access roads, and a rail yard facility for the import and export of animals. The Ayleshire Quartermaster Remount Depot remained in operation throughout both world wars, and was eventually expanded to include a canine training facility and detention barracks for 600 German and Italian prisoners of war.
In 1948 Congress passed legislat
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https://en.wikipedia.org/wiki/Chiral%20auxiliary
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In stereochemistry, a chiral auxiliary is a stereogenic group or unit that is temporarily incorporated into an organic compound in order to control the stereochemical outcome of the synthesis. The chirality present in the auxiliary can bias the stereoselectivity of one or more subsequent reactions. The auxiliary can then be typically recovered for future use.
Most biological molecules and pharmaceutical targets exist as one of two possible enantiomers; consequently, chemical syntheses of natural products and pharmaceutical agents are frequently designed to obtain the target in enantiomerically pure form. Chiral auxiliaries are one of many strategies available to synthetic chemists to selectively produce the desired stereoisomer of a given compound.
Chiral auxiliaries were introduced by Elias James Corey in 1975 with chiral 8-phenylmenthol and by Barry Trost in 1980 with chiral mandelic acid. The menthol compound is difficult to prepare and as an alternative trans-2-phenyl-1-cyclohexanol was introduced by J. K. Whitesell in 1985.
Asymmetric synthesis
Chiral auxiliaries are incorporated into synthetic routes to control the absolute configuration of stereogenic centers. David A. Evans' synthesis of the macrolide cytovaricin, considered a classic, utilizes oxazolidinone chiral auxiliaries for one asymmetric alkylation reaction and four asymmetric aldol reactions, setting the absolute stereochemistry of nine stereocenters.
A typical auxiliary-guided stereoselective transformat
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https://en.wikipedia.org/wiki/Trans-2-Phenyl-1-cyclohexanol
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trans-2-Phenyl-1-cyclohexanol is an organic compound. The two enantiomers of this compound are used in organic chemistry as chiral auxiliaries.
Preparation
The enantioselective synthesis was accomplished by J. K. Whitesell by adding Pseudomonas fluorescens lipase to racemic trans-2-phenylcyclohexyl chloroacetate. This enzyme is able to hydrolyze the ester bond of the (−)-enantiomer but not the (+)-enantiomer. The (−)-cyclohexanol and the (+)-ester are separated by fractional crystallization and the isolated (+)-ester hydrolyzed to the (+)-cyclohexanol in a separate step.
The enantiomers have also been prepared by the Sharpless asymmetric dihydroxylation of 1-phenylcyclohexene to the diol followed by the selective reduction of the 1-hydroxyl group by Raney nickel.
References
Secondary alcohols
Phenyl compounds
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https://en.wikipedia.org/wiki/Cocycle
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In mathematics a cocycle is a closed cochain. Cocycles are used in algebraic topology to express obstructions (for example, to integrating a differential equation on a closed manifold). They are likewise used in group cohomology. In autonomous dynamical systems, cocycles are used to describe particular kinds of map, as in the Oseledets theorem.
Definition
Algebraic Topology
Let X be a CW complex and be the singular cochains with coboundary map . Then elements of are cocycles. Elements of are coboundaries. If is a cocycle, then , which means cocycles vanish on boundaries.
See also
Čech cohomology
Cocycle condition
References
Algebraic topology
Cohomology theories
Dynamical systems
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https://en.wikipedia.org/wiki/Robert%20Harper%20%28computer%20scientist%29
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Robert William "Bob" Harper, Jr. (born ) is a computer science professor at Carnegie Mellon University who works in programming language research. Prior to his position at Carnegie Mellon, Harper was a research fellow at the University of Edinburgh.
Career
Harper made major contributions to the design of the Standard ML programming language and the LF logical framework.
Harper was named an ACM Fellow in 2005 for his contributions to type systems for programming languages. In 2021, he received the ACM SIGPLAN Programming Languages Achievement Award for his "foundational contributions to our understanding of type theory and its use in the design, specification, implementation, and verification of modern programming languages".
Books
Robin Milner, Mads Tofte, Robert Harper, and David MacQueen. The Definition of Standard ML (Revised). MIT Press, 1997.
Robert Harper (editor). Types in Compilation. Springer-Verlag Lecture Notes in Computer Science, volume 2071, 2001.
Robert Harper. Type Systems for Programming Languages. Draft, 2000.
Robert Harper. Programming in Standard ML. Working Draft, 2013.
Robert Harper. Practical Foundations for Programming Languages, 2007 draft. 2nd edition: , 2016.
Personal life
In 2003–2008, Harper hosted the progressive talk show Left Out on WRCT-FM with fellow host and Carnegie Mellon University School of Computer Science faculty member Danny Sleator.
References
Bibliography
Robert Harper's Homepage
Existential Type, Robert Harper's blog
P
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https://en.wikipedia.org/wiki/Pohlmeyer%20charge
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In theoretical physics Pohlmeyer charge, named for Klaus Pohlmeyer, is a conserved charge invariant under the Virasoro algebra or its generalization. It can be obtained by expanding the holonomies (generating functions)
with respect to the constant matrices T. The gauge field is defined as a combination of and its conjugate.
According to the logic of loop quantum gravity and algebraic quantum field theory, these charges are the right physical quantities that should be used for quantization. This logic is however incompatible with the standard and well-established methods of quantum field theory based on Fock space and perturbation theory.
Theoretical physics
Quantum field theory
Conformal field theory
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https://en.wikipedia.org/wiki/Civic%20Biology
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A Civic Biology: Presented in Problems (usually referred to as just Civic Biology) was a biology textbook written by George William Hunter, published in 1914. It is the book which the state of Tennessee required high school teachers to use in 1925 and is best known for its section about evolution that was ruled by a local court to be in violation of the state Butler Act. It was for teaching from this textbook that John T. Scopes was brought to trial in Dayton, Tennessee in the Scopes "Monkey" Trial. The views espoused in the book about evolution, race, and eugenics were common to American Progressives (especially in the work of Charles Benedict Davenport, one of the most prominent American biologists of the early 20th century, whom Hunter cites in the book).
Excerpts
Excerpts from the book give its general tone and approach to controversial topics regarding mankind:
Development and publication
Hunter was born in Mamaroneck, New York, and was educated at Williams College, the University of Chicago, and New York University, where he obtained his doctorate. He later became chairman of the biology department at his alma mater, De Witt Clinton High School, a public secondary school for boys in Manhattan. During his time at Clinton, he wrote or co-authored 30 textbooks for college and high school biology courses, including Civic Biology in 1905. By working with educators at Columbia University's Teachers College and the geneticist Thomas Hunt Morgan, Hunter developed Civic Biolo
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https://en.wikipedia.org/wiki/Lottery%20mathematics
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Lottery mathematics is used to calculate probabilities of winning or losing a lottery game. It is based primarily on combinatorics, particularly the twelvefold way and combinations without replacement.
Choosing 6 from 49
In a typical 6/49 game, each player chooses six distinct numbers from a range of 1-49. If the six numbers on a ticket match the numbers drawn by the lottery, the ticket holder is a jackpot winner—regardless of the order of the numbers. The probability of this happening is 1 in 13,983,816.
The chance of winning can be demonstrated as follows: The first number drawn has a 1 in 49 chance of matching. When the draw comes to the second number, there are now only 48 balls left in the bag, because the balls are drawn without replacement. So there is now a 1 in 48 chance of predicting this number.
Thus for each of the 49 ways of choosing the first number there are 48 different ways of choosing the second. This means that the probability of correctly predicting 2 numbers drawn from 49 in the correct order is calculated as 1 in 49 × 48. On drawing the third number there are only 47 ways of choosing the number; but we could have arrived at this point in any of 49 × 48 ways, so the chances of correctly predicting 3 numbers drawn from 49, again in the correct order, is 1 in 49 × 48 × 47. This continues until the sixth number has been drawn, giving the final calculation, 49 × 48 × 47 × 46 × 45 × 44, which can also be written as or 49 factorial divided by 43 factorial
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https://en.wikipedia.org/wiki/St%20George%27s%20University%20Hospitals%20NHS%20Foundation%20Trust
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St George's University Hospitals NHS Foundation Trust, formerly called St George's Healthcare NHS Trust, is based in Tooting in the London Borough of Wandsworth, and serves a population of 1.3 million across southwest London. A large number of services, such as cardiothoracic medicine and surgery, neurosciences and renal transplantation, also cover significant populations from Surrey and Sussex, totalling about 3.5 million people.
As of 2018, the trust employs 9,309 staff.
On 1 October 2010 St George's Healthcare integrated with Community Services Wandsworth, formerly the provider arm of NHS Wandsworth. This integration saw Community Services Wandsworth become the Community Services Wandsworth division of St George's Healthcare NHS Trust, with the 1,200 members of staff becoming employees of St George's Healthcare under TUPE.
St George's Healthcare incorporates St George's Hospital in Tooting and a full range of community services provided at Queen Mary's Hospital, Roehampton, St John's Therapy Centre in Battersea, HMP Wandsworth, health centres and clinics, GP surgeries, schools and in people's homes throughout Wandsworth.
St George's Hospital
St George's Hospital is one of the UK's largest teaching hospitals. It shares its main hospital site in Tooting, England with the renowned St George's, University of London which trains NHS staff and carries out advanced medical research.
The hospital has around 1,000 beds and provides all the usual care you would expect from a l
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https://en.wikipedia.org/wiki/Interleave%20sequence
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In mathematics, an interleave sequence is obtained by merging two sequences via an in shuffle.
Let be a set, and let and , be two sequences in The interleave sequence is defined to be the sequence . Formally, it is the sequence given by
Properties
The interleave sequence is convergent if and only if the sequences and are convergent and have the same limit.
Consider two real numbers a and b greater than zero and smaller than 1. One can interleave the sequences of digits of a and b, which will determine a third number c, also greater than zero and smaller than 1. In this way one obtains an injection from the square to the interval (0, 1). Different radixes give rise to different injections; the one for the binary numbers is called the Z-order curve or Morton code.
References
Real analysis
Sequences and series
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https://en.wikipedia.org/wiki/Stolz%E2%80%93Ces%C3%A0ro%20theorem
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In mathematics, the Stolz–Cesàro theorem is a criterion for proving the convergence of a sequence. The theorem is named after mathematicians Otto Stolz and Ernesto Cesàro, who stated and proved it for the first time.
The Stolz–Cesàro theorem can be viewed as a generalization of the Cesàro mean, but also as a l'Hôpital's rule for sequences.
Statement of the theorem for the case
Let and be two sequences of real numbers. Assume that is a strictly monotone and divergent sequence (i.e. strictly increasing and approaching , or strictly decreasing and approaching ) and the following limit exists:
Then, the limit
Statement of the theorem for the case
Let and be two sequences of real numbers. Assume now that and while is strictly decreasing. If
then
Proofs
Proof of the theorem for the case
Case 1: suppose strictly increasing and divergent to , and . By hypothesis, we have that for all there exists such that
which is to say
Since is strictly increasing, , and the following holds
.
Next we notice that
thus, by applying the above inequality to each of the terms in the square brackets, we obtain
Now, since as , there is an such that for all , and we can divide the two inequalities by for all
The two sequences (which are only defined for as there could be an such that )
are infinitesimal since and the numerator is a constant number, hence for all there exists , such that
therefore
which concludes the proof. The case with strictly decreasi
|
https://en.wikipedia.org/wiki/Square%20lattice
|
In mathematics, the square lattice is a type of lattice in a two-dimensional Euclidean space. It is the two-dimensional version of the integer lattice, denoted as . It is one of the five types of two-dimensional lattices as classified by their symmetry groups; its symmetry group in IUC notation as , Coxeter notation as , and orbifold notation as .
Two orientations of an image of the lattice are by far the most common. They can conveniently be referred to as the upright square lattice and diagonal square lattice; the latter is also called the centered square lattice. They differ by an angle of 45°. This is related to the fact that a square lattice can be partitioned into two square sub-lattices, as is evident in the colouring of a checkerboard.
Symmetry
The square lattice's symmetry category is wallpaper group . A pattern with this lattice of translational symmetry cannot have more, but may have less symmetry than the lattice itself.
An upright square lattice can be viewed as a diagonal square lattice with a mesh size that is √2 times as large, with the centers of the squares added. Correspondingly, after adding the centers of the squares of an upright square lattice one obtains a diagonal square lattice with a mesh size that is √2 times as small as that of the original lattice.
A pattern with 4-fold rotational symmetry has a square lattice of 4-fold rotocenters that is a factor √2 finer and diagonally oriented relative to the lattice of translational symmetry.
With respect
|
https://en.wikipedia.org/wiki/Scirus
|
Scirus was a comprehensive science-specific search engine, first launched in 2001. Like CiteSeerX and Google Scholar, it was focused on scientific information. Unlike CiteSeerX, Scirus was not only for computer sciences and IT and not all of the results included full text. It also sent its scientific search results to Scopus, an abstract and citation database covering scientific research output globally. Scirus was owned and operated by Elsevier.
In 2013 an announcement appeared, on the Scirus homepage, announcing the site's retirement in 2014:
"We are sad to say goodbye. Scirus is set to retire in early 2014. An official retirement date will be posted here as soon as it is determined. To ensure a smooth transition, we are informing you now so that you have sufficient time to find an alternative search solution for science-specific content. Thank you for being a devoted user of Scirus. We have enjoyed serving you."
By February 2014, the Scirus homepage indicated that the service was no longer running.
See also
Academic databases and search engines
Author-level metrics
CiteSeerX
Impact factor
References
External links
Scirus homepage
Scirus, Péter's Digital Reference Shelf, Gale Reference Reviews
Bibliographic databases and indexes
Elsevier
Scholarly search services
|
https://en.wikipedia.org/wiki/Vidya%20Vardhaka%20College%20of%20Engineering
|
Vidyavardhaka College of Engineering (VVCE) is a premier autonomous institute under VTU situated in Gokulam, Mysuru, Karnataka, India. As an autonomous institution, it follows the guidelines set by Visvesvaraya Technological University. It offers courses on Computer science, Information science, Artificial Intelligence & Machine Learning, Electronics and Communication, Electrical and Electronics, Civil engineering, Mechanical engineering.
Description
Vidyavardhaka College of Engineering is recognized by the Government of Karnataka and the All India Council for Technical Education. Programs of study offered include bachelor's degrees in mechanical, electronics, computer science, information sciences, Artificial Intelligence & Machine Learning and electrical engineering. Six programs, IS&E, E&EE, CS&E, E&CE, ME and CV of VVCE have been accredited by National Board of Accreditation for three years i.e. academic years 2020-2021 to 2022-2023 of date up to 30 June 2023. The college is also accredited with 'A' Grade by National Assessment and Accreditation Council (NAAC) for five Years from the year 2018. The college was founded by the Vidyavrdhaka Sangha in 1997.
The college is located in Gokulam, a residential suburb, north of the central bus station and from the Mysuru railway station.
Academic programs
Courses offered:
Undergraduate programs
Artificial Intelligence & Machine Learning
Civil Engineering
Computer Science & Engineering
Electrical & Electronics Engine
|
https://en.wikipedia.org/wiki/Energy%E2%80%93momentum%20relation
|
In physics, the energy–momentum relation, or relativistic dispersion relation, is the relativistic equation relating total energy (which is also called relativistic energy) to invariant mass (which is also called rest mass) and momentum. It is the extension of mass–energy equivalence for bodies or systems with non-zero momentum. It can be written as the following equation:
This equation holds for a body or system, such as one or more particles, with total energy , invariant mass , and momentum of magnitude ; the constant is the speed of light. It assumes the special relativity case of flat spacetime and that the particles are free. Total energy is the sum of rest energy and kinetic energy, while invariant mass is mass measured in a center-of-momentum frame.
For bodies or systems with zero momentum, it simplifies to the mass–energy equation , where total energy in this case is equal to rest energy (also written as ).
The Dirac sea model, which was used to predict the existence of antimatter, is closely related to the energy–momentum relation.
Connection to
The energy–momentum relation is consistent with the familiar mass–energy relation in both its interpretations: relates total energy to the (total) relativistic mass (alternatively denoted or ), while relates rest energy to (invariant) rest mass .
Unlike either of those equations, the energy–momentum equation () relates the total energy to the rest mass . All three equations hold true simultaneously.
Speci
|
https://en.wikipedia.org/wiki/Les%20Kershaw
|
Les Kershaw is the former chief scout and Academy Director for Manchester United.
Kershaw studied at Manchester Metropolitan University before being recruited by United manager Alex Ferguson. He had previously acted as a part-time scout for Arsenal.
He received an award from the Royal Society of Chemistry in September 2005.
Kershaw retired at the end of the 2005–06 season and was replaced as Director of the Academy by Brian McClair. However, he continued to work for United part-time, and was credited with discovering Rafael and Fábio da Silva.
See also
Manchester United F.C. Reserves and Academy
References
Living people
Manchester United F.C. non-playing staff
Year of birth missing (living people)
Association football scouts
Arsenal F.C. non-playing staff
|
https://en.wikipedia.org/wiki/Anneila%20Sargent
|
Professor Anneila Isabel Sargent FRSE DSc (born Anneila Cassells, 1942) is a Scottish–American astronomer who specializes in star formation.
Biography
Sargent was brought up in Burntisland, Fife, and schooled at Burntisland Primary School and Kirkcaldy High School. She completed a BSc Honours degree in Physics at the University of Edinburgh in 1963, and then immigrated to the United States, first studying at the University of California, Berkeley, and then from 1967 the California Institute of Technology, where she was awarded her Ph.D in 1977. She is currently the Ira S. Bowen Professor of Astronomy, Emeritus at Caltech and has served as director of the Owens Valley Radio Observatory and Combined Array for Research in Millimeter-wave Astronomy. She served as president of the American Astronomical Society from 2000 to 2002, continuing to serve on the council since. Sargent was the Vice President for Student Affairs at Caltech from 1 December 2007 until 2016.
Sargent was nominated in 2011 by President Obama to serve a six-year term on the National Science Board. She has served on committees such as the NRC Committee for Astronomy and Astrophysics, the NSF Mathematical and Physical Sciences Advisory Committee, and in 1995/6 chaired the Visiting Committee to the National Radio Astronomy Observatory. She has been Chair of NASA's Space Science Advisory Committee since 1994. She is also Director of the Combined Array for Research in Millimeterwave Astronomy (CARMA).
Honours and
|
https://en.wikipedia.org/wiki/Rickmansworth%20School
|
Rickmansworth School in Croxley Green, Hertfordshire, is a coeducational secondary school and a sixth form with academy status for 1,400 pupils.
Rickmansworth is a secondary school for boys and girls aged 11 to 18 of all academic abilities, although 25% of the 11+ intake are selected using tests in mathematics and verbal reasoning, with a further 10% selected for aptitude in music. Most children are admitted at 11 and there is an additional intake at 16 into the Sixth Form.
Rickmansworth is a self-governing academy school and the governing body are responsible for the employment of staff, the admission of pupils, and all aspects of the organisation and running of the School. Previously the school was a 'grant maintained school' in the 1990s, with much the same powers.
Location
The school stands in twenty-six acres of Metropolitan Green Belt woodland situated in a residential area well served by road and rail, on the south side of the A412 road. The M25 motorway is five minutes distance by car, and Croxley and Rickmansworth Metropolitan line stations are ten- and fifteen-minute walks respectively. Watford Junction station (National Rail to London Euston) is fifteen to twenty minutes by car.
History
Grammar school (1953–1969)
Rickmansworth Grammar School was the fifth grammar school to be built after the war.
The school was built on the site of a house called Briery Close, which had been the residence of the vicar of Rickmansworth but had fallen vacant before the war.
Be
|
https://en.wikipedia.org/wiki/Stuart%20Parkin
|
Stuart Stephen Papworth Parkin (born 9 December 1955) is an experimental physicist, director at the Max Planck Institute of Microstructure Physics in Halle and an Alexander von Humboldt Professor at the Institute of Physics of the Martin-Luther-University Halle-Wittenberg.
He is a pioneer in the science and application of spintronic materials, and has made discoveries into the behaviour of thin-film magnetic structures that were critical in enabling recent increases in the data density and capacity of computer hard-disk drives. For these discoveries, he was awarded the 2014 Millennium Technology Prize.
Before his current position, Parkin was an IBM Fellow and manager of the magnetoelectronics group at the IBM Almaden Research Center in San Jose, California. He was also a consulting professor in the department of applied physics at Stanford University and director of the IBM-Stanford Spintronic Science and Applications Center, which was formed in 2004.
Education and early life
A native of Watford, England, Parkin received his B.A. (1977) and was elected a research fellow (1979) at Trinity College, Cambridge, England, and was awarded his PhD (1980) at the Cavendish Laboratory, also in Cambridge. He joined IBM in 1982 as a World Trade Post-doctoral Fellow, becoming a permanent member of the staff the following year. In 1999 he was named an IBM Fellow, IBM's highest technical honour.
Research and career
In 2007 Parkin was named a distinguished visiting professor at the Nation
|
https://en.wikipedia.org/wiki/Francisco%20Javier%20Salazar%20S%C3%A1enz
|
Francisco Javier Salazar Sáenz is a Mexican politician affiliated with the National Action Party . He was the Secretary of Labor from 2005 to 2006.
Education
Salazar Sáenz studied chemistry at the National Autonomous University of Mexico (UNAM) and at the Universidad Iberoamericana. He received a master's degree in administration from the Universidad Autónoma de San Luis Potosí and a doctorate in social sciences from the University of La Salle in Mexico city.
Public career
During the 1980s Salazar Sáenz was an active labor leader in San Luis Potosí state. He was general secretary of the Unión de Asociaciones de Personal Académico de la Universidad Autonoma de San Luis Potosí (1979 to 1985), general secretary of the Asociación Nacional de Asociaciones de Personal Académico Universitario (1984 to 1988) and general secretary of the Confederación Nacional de Trabajadores Universitarios (1985 to 1989).
Salazar Sáenz served in the Chamber of Deputies during the 60th legislative session and in the Mexican Senate during the 61st and 62nd sessions.
In 2005 Mexican President Vicente Fox appointed Salazar as Secretary of Labor.
References
1958 births
Mexican trade unionists
Members of the Chamber of Deputies (Mexico)
Members of the Senate of the Republic (Mexico)
Mexican people of Basque descent
National Action Party (Mexico) politicians
Mexican Secretaries of Labor
Living people
21st-century Mexican politicians
|
https://en.wikipedia.org/wiki/Tkdiff
|
tkdiff is a graphical diff viewer based on the Tk framework. It is capable of inter-operating with source-control systems like CVS and Subversion to show the differences between the local copy and the repository version. Such a line-by-line comparison is often considered to be good software engineering practice before committing code changes.
Tkdiff highlight specific differences within a line shared by both files, rather than simply indicating that the whole line differs.
Example usage
tkdiff <file1> <file2> — to compare the two files <file1> and <file2>
tkdiff <file> — to compare the local version of the given file to the most recent version in the CVS/Subversion repository
tkdiff can also compare two older revisions of a file, etc.
References
Free file comparison tools
|
https://en.wikipedia.org/wiki/Icosahedral%20symmetry
|
In mathematics, and especially in geometry, an object has icosahedral symmetry if it has the same symmetries as a regular icosahedron. Examples of other polyhedra with icosahedral symmetry include the regular dodecahedron (the dual of the icosahedron) and the rhombic triacontahedron.
Every polyhedron with icosahedral symmetry has 60 rotational (or orientation-preserving) symmetries and 60 orientation-reversing symmetries (that combine a rotation and a reflection), for a total symmetry order of 120. The full symmetry group is the Coxeter group of type . It may be represented by Coxeter notation and Coxeter diagram . The set of rotational symmetries forms a subgroup that is isomorphic to the alternating group on 5 letters.
Description
Icosahedral symmetry is a mathematical property of objects indicating that an object has the same symmetries as a regular icosahedron.
As point group
Apart from the two infinite series of prismatic and antiprismatic symmetry, rotational icosahedral symmetry or chiral icosahedral symmetry of chiral objects and full icosahedral symmetry or achiral icosahedral symmetry are the discrete point symmetries (or equivalently, symmetries on the sphere) with the largest symmetry groups.
Icosahedral symmetry is not compatible with translational symmetry, so there are no associated crystallographic point groups or space groups.
Presentations corresponding to the above are:
These correspond to the icosahedral groups (rotational and full) being the
|
https://en.wikipedia.org/wiki/Developable%20surface
|
In mathematics, a developable surface (or torse: archaic) is a smooth surface with zero Gaussian curvature. That is, it is a surface that can be flattened onto a plane without distortion (i.e. it can be bent without stretching or compression). Conversely, it is a surface which can be made by transforming a plane (i.e. "folding", "bending", "rolling", "cutting" and/or "gluing"). In three dimensions all developable surfaces are ruled surfaces (but not vice versa). There are developable surfaces in four-dimensional space which are not ruled.
The envelope of a single parameter family of planes is called a developable surface.
Particulars
The developable surfaces which can be realized in three-dimensional space include:
Cylinders and, more generally, the "generalized" cylinder; its cross-section may be any smooth curve
Cones and, more generally, conical surfaces; away from the apex
The oloid and the sphericon are members of a special family of solids that develop their entire surface when rolling down a flat plane.
Planes (trivially); which may be viewed as a cylinder whose cross-section is a line
Tangent developable surfaces; which are constructed by extending the tangent lines of a spatial curve.
The torus has a metric under which it is developable, which can be embedded into three-dimensional space by the Nash embedding theorem and has a simple representation in four dimensions as the Cartesian product of two circles: see Clifford torus.
Formally, in mathematics, a d
|
https://en.wikipedia.org/wiki/N-Methylmorpholine%20N-oxide
|
N-Methylmorpholine N-oxide (more correctly 4-methylmorpholine 4-oxide), NMO or NMMO is an organic compound. This heterocyclic amine oxide and morpholine derivative is used in organic chemistry as a co-oxidant and sacrificial catalyst in oxidation reactions for instance in osmium tetroxide oxidations and the Sharpless asymmetric dihydroxylation or oxidations with TPAP. NMO is commercially supplied both as a monohydrate C5H11NO2·H2O and as the anhydrous compound. The monohydrate is used as a solvent for cellulose in the lyocell process to produce cellulose fibers.
Uses
Solvent of cellulose
NMMO monohydrate is used as a solvent in the lyocell process to produce lyocell fiber. It dissolves cellulose to form a solution called dope, and the cellulose is reprecipitated in a water bath to produce a fiber. The process is similar but not analogous to the viscose process. In the viscose process, cellulose is made soluble by conversion to its xanthate derivatives. With NMMO, cellulose is not derivatized but dissolves to give a homogeneous polymer solution. The resulting fiber is similar to viscose; this was observed, for example, for Valonia cellulose microfibrils. Dilution with water causes the cellulose to reprecipitate, i.e. the solvation of cellulose with NMMO is a water sensitive process.
Cellulose remains insoluble in most solvents because it has a strong and highly structured intermolecular hydrogen bonding network, which resists common solvents. NMMO breaks the hydrogen bondin
|
https://en.wikipedia.org/wiki/Rel
|
Rel or REL may mean:
Science and technology
REL, a human gene
the rel descriptor of stereochemistry, see Relative configuration
REL (Rassemblement Européen pour la Liberté), European Rally for Liberty, a defunct French far-right party active in the 1960s
Category of relations or Rel, a mathematical category of sets and relations
Rel (DBMS), a database management system
Rel attribute, an HTML attribute for indicating a semantic link
Recommended Exposure Limit, a recommended limit for occupational exposures published by the National Institute for Occupational Safety and Health
Rights Expression Language, a machine-processable language used for digital rights management
People
Rel Dowdell, American screenwriter, film director, film producer, and English/screenwriting educator
Nickname of Arielle Gold, American world champion and Olympic bronze medalist snowboarder
Rel Hunt (born 1974), Australian actor
Nickname of Ariel Schulman (born 1981), American actor, film director, and producer
Robert E. Lee Confederate leader.
Other uses
Rel (TV series), a 2018 American television sitcom
Rel (time), a fictional Dalek unit of time measurement roughly equal to one second
Magic: The Gathering Organized Play Rules Enforcement Level
Reaction Engines Limited, a British aerospace company
Religare Enterprises Limited, an Indian holding company
Almirante Marcos A. Zar Airport IATA code
Rendille language ISO 639-3 language code, spoken in Kenya
See also
Ex rel, abbreviatio
|
https://en.wikipedia.org/wiki/Helsinki%20Institute%20of%20Physics
|
The Helsinki Institute of Physics (HIP, , ) is a physics research institute operated jointly by University of Helsinki, Aalto University, University of Jyväskylä, Lappeenranta University of Technology and Tampere University of Technology. The operations of the institute began on September 1, 1996. The foundation of the institute was provided by the three previous Helsinki-based institutes: SEFT, TFT (University of Helsinki) and HTI (Helsinki University of Technology), which were merged into the new organization. The current director of the institute since 2017 has been prof. Katri Huitu. The institute is responsible for the Finnish research collaboration with CERN and Facility for Antiproton and Ion Research in Europe GmbH (FAIR).
The research is currently focused on following fields:
Theory Programme
Nuclear Structure for Weak and Astrophysical Processes
QCD and Strongly Interacting Gauge Theory
Domain Wall Dynamics
Cosmology of the Early and Late Universe
High Energy Phenomenology in the LHC Era
CMS Programme
CMS Experiment
CMS Upgrade
Tier-2 Operations
TOTEM
Technology Programme
Accelerator Technology
Green Big Data Project
Biomedical Imaging
Novel Instrumentation for Nuclear Safety, Security and Safeguards
Finnish Business Incubation Center of CERN Technologies
Nuclear Matter Programme
ALICE
ISOLDE
FAIR
References
External links
HIP website
Research institutes in Finland
Buildings and structures in Helsinki
University of Helsinki
Physics res
|
https://en.wikipedia.org/wiki/Finnish%20Institute%20for%20Verification%20of%20the%20Chemical%20Weapons%20Convention
|
The Finnish Institute for Verification of the Chemical Weapons Convention (VERIFIN) is a Finnish institute carrying out several roles in support of chemical weapons disarmament.
Established in 1994 as a continuation of a research project started in 1973, it is located within the Chemistry Department of the Kumpula Campus of the University of Helsinki.
Funded by the Finnish Ministry for Foreign Affairs, its main task is to develop improved methods of verification of chemical weapons disarmament. The particular approach adopted is to refine analytical chemical techniques for identifying traces of chemical weapons, their precursors and their degradation products.
The institute is the National Authority for Finland under the Chemical Weapons Convention, carrying out many of the tasks required by the treaty such as preparing the Finnish Government declarations to the OPCW of inventories of controlled substances and escorting OPCW inspections of Finnish chemical production facilities. It is also one of the 18 OPCW designated laboratories worldwide for performing chemical weapons verification tests, a role it has performed since 1998.
The institute also runs several courses on chemical weapons verification for chemists from developing countries.
In 2014 VERIFIN was awarded The OPCW-The Hague Award in recognition of its outstanding leadership in the development of advanced verification methods for use in the detection and identification of chemical weapons and their components.
|
https://en.wikipedia.org/wiki/Judy%20A.%20Holdener
|
Judy Holdener (née Newhauser) is an American mathematician and educator. She is a professor of mathematics at Kenyon College. She was born in 1965. Holdener's primary interest is in number theory. She discovered a simpler proof of the theorem of Touchard, which states that every perfect number is of the form 2k, 12k+1, or 36k+9.
Holdener earned her B.S. in mathematics at Kent State University and her M.S. and Ph.D. in mathematics at the University of Illinois at Urbana-Champaign. Holdener joined the faculty of Kenyon College in 1997, where she is currently the John B. McCoy Distinguished Teaching Chair.
The poem Euler's Daughter by award-winning South African poet Athol Williams is dedicated to Holdener in celebration of her love of mathematics and life.
References
.
.
External links
Biography Page at Kenyon College
Number theorists
20th-century American mathematicians
21st-century American mathematicians
American women mathematicians
Kent State University alumni
University of Illinois alumni
Kenyon College faculty
Living people
1965 births
20th-century women mathematicians
21st-century women mathematicians
20th-century American women
21st-century American women
|
https://en.wikipedia.org/wiki/William%20J.%20Ruane
|
William J. Ruane (October 24, 1925 – October 4, 2005) was an American businessman, investor, and philanthropist.
Ruane graduated from the University of Minnesota in 1945 with a degree in electrical engineering and from Harvard Business School in 1949. He enlisted in the U.S. Navy and was on his way to Japan when World War II ended. He met Warren Buffett at an investment seminar with value investing guru Benjamin Graham and he and Buffett became lifelong friends. When Buffett closed his investment group in 1969, he advised associates to consider investing with Ruane as they both employed Graham's value investing techniques.
Ruane founded his own investment firm, Ruane Cunniff, with partner Rick Cunniff in 1970, and the same year they launched their flagship Sequoia Fund. Ruane's firm was renamed Ruane, Cunniff, and Goldfarb in 2004, when Robert Goldfarb became president. In 2008, the Sequoia Fund announced it would open its fund to new investors for the first time since 1982.
In 1992 he adopted a block in the Harlem neighborhood of New York City, committed to make it a better place, renovating buildings and establishing clinics and community service programs. Ruane gave every child on the block a scholarship to a Catholic school. He also funded programs at public schools and schools on Indian reservations, and contributed to mental health causes.
Death
He died at Memorial Sloan-Kettering Cancer Center in Manhattan, aged 79 (several weeks before his 80th birthday) of lung c
|
https://en.wikipedia.org/wiki/Claude%20Cr%C3%A9peau
|
Claude Crépeau is a professor in the School of Computer Science at McGill University. Ηe was born in Montreal, Quebec, Canada, in 1962. He received a master's degree from the Université de Montréal in 1986, and obtained his Ph.D. in Computer Science from MIT in 1990, working in the field of cryptography with Silvio Micali as his Ph.D. advisor and Gilles Brassard as his M.Sc advisor. He spent two years as a Postdoctoral
Fellow at Université d'Orsay, and was a CNRS researcher at École Normale Supérieure from 1992 to 1995. He was appointed associate professor at Université de Montréal in 1995,
and has been a faculty member at McGill University since 1998. He was a member of the Canadian Institute for Advanced Research
program on Quantum Information Processing from 2002 to 2012.
Crépeau is best known for his fundamental work in zero-knowledge proof, multi-party computing, quantum cryptography, and quantum teleportation.
In 1993, together with Charles H. Bennett, Gilles Brassard, Richard Jozsa, Asher Peres, and William Wootters, Crépeau invented quantum teleportation.
Publications
References
1962 births
20th-century Canadian scientists
21st-century Canadian scientists
Living people
Canadian computer scientists
Modern cryptographers
Scientists from Montreal
Academic staff of McGill University
Université de Montréal alumni
French National Centre for Scientific Research scientists
|
https://en.wikipedia.org/wiki/Journal%20of%20Molecular%20Biology
|
The Journal of Molecular Biology is a biweekly peer-reviewed scientific journal covering all aspects of molecular biology. It was established in 1959 and is published by Elsevier. The editor-in-chief is Peter Wright (The Scripps Research Institute).
Abstracting and indexing
The journal is abstracted and indexed in:
According to the Journal Citation Reports, the journal has a 2020 impact factor of 5.469.
Notable articles
Some of the most highly cited articles that have appeared in the journal are:
, in which Jacques Monod, Jeffries Wyman, and Jean-Pierre Changeux presented the MWC model, that explained the cooperativity exhibited by allosteric proteins, such as hemoglobin.
, in which Edwin Southern presented the first description of nucleic acid blotting, a technique that revolutionized the field of molecular biology.
, in which the Smith–Waterman algorithm for determining the degree of homology of DNA, RNA, or protein sequences was first described.
, in which the nucleic acid and protein homology search algorithm known as BLAST was originally described.
References
External links
Elsevier academic journals
Academic journals established in 1959
Biochemistry journals
Hybrid open access journals
Biweekly journals
English-language journals
|
https://en.wikipedia.org/wiki/Beverly%20Clock
|
The Beverly Clock is a clock in the 3rd-floor lift foyer of the Department of Physics at the University of Otago, Dunedin, New Zealand. The clock is still running despite never having been manually wound since its construction in 1864 by Arthur Beverly.
Operation
The clock's mechanism is driven by variations in daily temperature and, to a lesser extent, in atmospheric pressure. Either causes the air in a airtight box to expand or contract, which pushes on a diaphragm. A temperature variation of over the course of each day creates approximately enough pressure to raise a one-pound weight by one inch (equivalent to ), which drives the clock mechanism.
A similar mechanism in a commercially available clock that operates on the same principle is the Atmos clock, manufactured by the Swiss watchmaker Jaeger-LeCoultre.
While the clock has not been wound since it was made, it has stopped on a number of occasions, such as when its mechanism needed cleaning or there was a mechanical failure, and when the Physics Department moved to new quarters. Also, on occasions when the ambient temperature does not fluctuate sufficiently to supply the requisite amount of energy, the clock will not function. However, after environmental parameters readjust, the clock begins operating again.
See also
Long-term experiment
Oxford Electric Bell (1840)
Pitch drop experiment (1927)
Cox's timepiece
Clock of the Long Now
Atmos clock, a commercially available clock working on a similar principle
Temper
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