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https://en.wikipedia.org/wiki/Five%20Equations%20That%20Changed%20the%20World
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Five Equations That Changed the World: The Power and Poetry of Mathematics is a book by Michael Guillen, published in 1995.
It is divided into five chapters that talk about five different equations in physics and the people who have developed them.
The scientists and their equations are:
Isaac Newton (Universal Law of Gravity)
Daniel Bernoulli (Law of Hydrodynamic Pressure)
Michael Faraday (Law of Electromagnetic Induction)
Rudolf Clausius (Second Law of Thermodynamics)
Albert Einstein (Theory of Special Relativity)
The book is a light study in science and history, portraying the preludes to and times and settings of discoveries that have been the basis of further development, including space travel, flight and nuclear power. Each chapter of the book is divided into sections titled Veni, Vidi, Vici.
The reviews of the book have been mixed. Publishers Weekly called it "wholly accessible, beautifully written", Kirkus Reviews wrote that it is a "crowd-pleasing kind of book designed to make the science as palatable as possible", and Frank Mahnke wrote that Guillen "has a nice touch for the history of mathematics and physics and their impact on the world". However, in contrast, Charles Stephens panned "the superficiality of the author's treatment of scientific ideas", and the editors of The Capital Times called the book a "miserable failure" at its goal of helping the public appreciate the beauty of mathematics.
References
1995 non-fiction books
Popular physics books
Mat
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https://en.wikipedia.org/wiki/John%20Lawton%20%28biologist%29
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Sir John Hartley Lawton (born 24 September 1943) is a British ecologist, RSPB Vice President, President (former Chair) of the Yorkshire Wildlife Trust, President of The Institution of Environmental Sciences, Chairman of York Museums Trust and President of the York Ornithological Club.
He has previously been a trustee of WWF UK and head of Natural Environment Research Council (NERC) and was the last chair of the Royal Commission on Environmental Pollution. In October 2011, he was awarded the RSPB Medal.
Early life
A a child, Lawton was a member of the Young Ornithologists' Club, and later helped run the RSPB Members' Group in York. In his youth, he volunteered for the RSPB's Operation Osprey at Loch Garten.
Career
Lawton studied at the University of Durham, completing a Bachelor of Science in Zoology followed by a PhD in 1969. He belonged to University College. Lawton was Demonstrator in Ecology in the Department of Zoology at the University of Oxford from 1968, moving to the University of York in 1971. He was awarded a Personal Chair at York in 1985. He founded, and was the first Director of, the NERC Centre for Population Biology at Imperial College, Silwood Park.
In October 1999, he was appointed the Chief Executive of NERC, retaining an honorary professorship at Imperial College of Science, Technology and Medicine. Following his retirement from NERC in March 2005, he was appointed Chairman of the Royal Commission on Environment Pollution from 1 April 2005, and was r
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https://en.wikipedia.org/wiki/Necking%20%28engineering%29
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In engineering and materials science, necking is a mode of tensile deformation where relatively large amounts of strain localize disproportionately in a small region of the material. The resulting prominent decrease in local cross-sectional area provides the basis for the name "neck". Because the local strains in the neck are large, necking is often closely associated with yielding, a form of plastic deformation associated with ductile materials, often metals or polymers. Once necking has begun, the neck becomes the exclusive location of yielding in the material, as the reduced area gives the neck the largest local stress.
Formation
Necking results from an instability during tensile deformation when the cross-sectional area of the sample decreases by a greater proportion than the material strain hardens. Armand Considère published the basic criterion for necking in 1885, in the context of the stability of large scale structures such as bridges. Three concepts provide the framework for understanding neck formation.
Before deformation, all real materials have heterogeneities such as flaws or local variations in dimensions or composition that cause local fluctuations in stresses and strains. To determine the location of the incipient neck, these fluctuations need only be infinitesimal in magnitude.
During plastic tensile deformation the material decreases in cross-sectional area due to the incompressibility of plastic flow. (Not due to the Poisson effect, which is linked
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https://en.wikipedia.org/wiki/Antoine%20Baum%C3%A9
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Antoine Baumé (26 February 172815 October 1804) was a French chemist.
Life
He was born at Senlis. He was apprenticed to the chemist Claude Joseph Geoffroy, and in 1752 was admitted a member of the École de Pharmacie, where in the same year he was appointed professor of chemistry. The money he made in a business he carried on in Paris for dealing in chemical products enabled him to retire in 1780 in order to devote himself to applied chemistry, but, ruined in the Revolution, he was obliged to return to a commercial career.
He devised many improvements in technical processes, e.g. for bleaching silk, dyeing, gilding, purifying saltpetre, etc., but he is best known as the inventor of the Baumé scale hydrometer or "spindle" which provides scientific measurements for the density of liquids.
The scale remains associated with his name but is often improperly spelt "Beaumé".
Of the numerous books and papers he wrote the most important is his Éléments de pharmacie théorique et pratique (9 editions, 1762–1818). He became a member of the Academy of Sciences in 1772, and an associate of the Institute in 1796. He died in Paris on 15 October 1804.
Works
Eléments de Pharmacie théorique et pratique . Samson, Paris Nouvelle Ed. 1770 Digital edition / 3rd ed. 1773 Digital edition / 4th ed. 1777 Digital edition / 5th ed. 1784 Digital edition by the University and State Library Düsseldorf (9 editions, from 1762 to 1818)
Manuel de chymie ou exposé des opérations de la chymie et de le
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https://en.wikipedia.org/wiki/The%20Geometer%27s%20Sketchpad
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The Geometer's Sketchpad is a commercial interactive geometry software program for exploring Euclidean geometry, algebra, calculus, and other areas of mathematics. It was created as part of the NSF-funded Visual Geometry Project led by Eugene Klotz and Doris Schattschneider from 1986 to 1991 at Swarthmore College. Nicholas Jackiw, a student at the time, was the original designer and programmer of the software, and inventor of its trademarked "Dynamic Geometry" approach; he later moved to Key Curriculum Press, KCP Technologies, and McGraw-Hill Education to continue ongoing design and implementation of the software over multiple major releases and hardware platforms. Present versions run Microsoft Windows and MacOS Ventura. It also runs on Linux under Wine with a few bugs. There was also a version developed for the TI-89 and TI-92 series of Calculators. In June 2019, McGraw-Hill announced that it would no longer sell new licenses. Nonetheless, a license-free 64-bit version of Mac Sketchpad that is compatible with the latest Apple silicon chips is available. A license-free Windows version of the software is also available. The Sketchpad Repository contains over 200 videos, with Sketchpad and Web Sketchpad tutorials as well as an archive of Sketchpad webinars that were offered by Key Curriculum Press.
Features
The Geometer's Sketchpad includes the traditional Euclidean tools of classical geometric constructions. It also can perform transformations (translations, rotations, ref
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https://en.wikipedia.org/wiki/Mary%20Everest%20Boole
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Mary Everest Boole (11 March 1832 in Wickwar, Gloucestershire – 17 May 1916 in Middlesex, England) was a self-taught mathematician who is best known as an author of didactic works on mathematics, such as Philosophy and Fun of Algebra, and as the wife of fellow mathematician George Boole. Her progressive ideas on education, as expounded in The Preparation of the Child for Science, included encouraging children to explore mathematics through playful activities such as curve stitching. Her life is of interest to feminists as an example of how women made careers in an academic system that did not welcome them.
Life
She was born in England, the daughter of Reverend Thomas Roupell Everest, Rector of Wickwar, and Mary nee Ryall. Her uncle was George Everest, the surveyor and geographer after whom Mount Everest was named. She spent the first part of her life in France where she received an education in mathematics from a private tutor. On returning to England at the age of 11, she continued to pursue her interest in mathematics through self-instruction. Self-taught mathematician George Boole tutored her, and she visited him in Ireland where he held the position of professor of mathematics at Queen's College Cork. Upon the death of her father in 1855, they married and she moved to Cork. Mary greatly contributed as an editor to Boole's The Laws of Thought, a work on algebraic logic. She had five daughters with him.
She was widowed in 1864, at the age of 32, and returned to England, w
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https://en.wikipedia.org/wiki/Jerome%20Lettvin
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Jerome Ysroael Lettvin (February 23, 1920 – April 23, 2011), often known as Jerry Lettvin, was an American cognitive scientist, and Professor of Electrical and Bioengineering and Communications Physiology at the Massachusetts Institute of Technology (MIT). He is best known as the lead author of the paper, "What the Frog's Eye Tells the Frog's Brain" (1959), one of the most cited papers in the Science Citation Index. He wrote it along with Humberto Maturana, Warren McCulloch and Walter Pitts, and in the paper they gave special thanks and mention to Oliver Selfridge at MIT. Lettvin carried out neurophysiological studies in the spinal cord, made the first demonstration of "feature detectors" in the visual system, and studied information processing in the terminal branches of single axons. Around 1969, he originated the term "grandmother cell" to illustrate the logical inconsistency of the concept.
Lettvin was also the author of many published articles on subjects varying from neurology and physiology to philosophy and politics. Among his many activities at MIT, he served as one of the first directors of the Concourse Program, and, along with his wife Maggie, was a houseparent of the Bexley dorm.
Early life
Lettvin was born February 23, 1920, in Chicago, the eldest of four children (including the pianist Theodore Lettvin) of Solomon and Fanny Lettvin, Jewish immigrants from Ukraine. After training as a neurologist and psychiatrist at the University of Illinois (BS, MD 1943), h
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https://en.wikipedia.org/wiki/Temporal%20resolution
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Temporal resolution (TR) refers to the discrete resolution of a measurement with respect to time.
Physics
Often there is a trade-off between the temporal resolution of a measurement and its spatial resolution, due to Heisenberg's uncertainty principle. In some contexts, such as particle physics, this trade-off can be attributed to the finite speed of light and the fact that it takes a certain period of time for the photons carrying information to reach the observer. In this time, the system might have undergone changes itself. Thus, the longer the light has to travel, the lower the temporal resolution.
Technology
Computing
In another context, there is often a tradeoff between temporal resolution and computer storage. A transducer may be able to record data every millisecond, but available storage may not allow this, and in the case of 4D PET imaging the resolution may be limited to several minutes.
Electronic displays
In some applications, temporal resolution may instead be equated to the sampling period, or its inverse, the refresh rate, or update frequency in Hertz, of a TV, for example.
The temporal resolution is distinct from temporal uncertainty. This would be analogous to conflating image resolution with optical resolution. One is discrete, the other, continuous.
The temporal resolution is a resolution somewhat the 'time' dual to the 'space' resolution of an image. In a similar way, the sample rate is equivalent to the pixel pitch on a display screen, whereas t
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https://en.wikipedia.org/wiki/SFE
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SFE may refer to:
Sales force effectiveness
San Fernando Airport (Philippines) IATA code
Scottish Financial Enterprise, trade body for the financial services sector in Scotland
Scouts for Equality, advocates for scouts and leaders in the Boy Scouts of America
Secure function evaluation, in cryptography
Sigma Phi Epsilon
Shannon-Fano-Elias coding, a lossless data compression algorithm
Society of Fuse Engineers, designers of certain automotive fuses
Solar flare effect
SparkFun Electronics
Spec Files Extra, a way to build common packages for OpenSolaris or OpenIndiana
Stacking-fault energy
Supercritical fluid extraction
Supplier-furnished equipment
Surface free energy, often referred to as Surface energy
Sydney Futures Exchange, now merged with the Australian Stock Exchange to become the Australian Securities Exchange
The Encyclopedia of Science Fiction
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https://en.wikipedia.org/wiki/Paramutation
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In epigenetics, a paramutation is an interaction between two alleles at a single locus, whereby one allele induces a heritable change in the other allele. The change may be in the pattern of DNA methylation or histone modifications. The allele inducing the change is said to be paramutagenic, while the allele that has been epigenetically altered is termed paramutable. A paramutable allele may have altered levels of gene expression, which may continue in offspring which inherit that allele, even though the paramutagenic allele may no longer be present. Through proper breeding, paramutation can result in siblings that have the same genetic sequence, but with drastically different phenotypes.
Though studied primarily in maize, paramutation has been described in a number of other systems, including animal systems like Drosophila melanogaster and mice. Despite its broad distribution, examples of this phenomenon are scarce and its mechanism is not fully understood.
History
The first description of what would come to be called paramutation was given by William Bateson and Caroline Pellew in 1915, when they described "rogue" peas that always passed their "rogue" phenotype onto their progeny. However, the first formal description of paramutation was given by R.A. Brink at the University of Wisconsin–Madison in the 1950s, who did his work in maize (Zea mays). Brink noticed that specific weakly expressed alleles of the red1 (r1) locus in maize, which encodes a transcription factor tha
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https://en.wikipedia.org/wiki/Transvection%20%28genetics%29
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Transvection is an epigenetic phenomenon that results from an interaction between an allele on one chromosome and the corresponding allele on the homologous chromosome. Transvection can lead to either gene activation or repression. It can also occur between nonallelic regions of the genome as well as regions of the genome that are not transcribed.
The first observation of mitotic (i.e. non-meiotic) chromosome pairing was discovered via microscopy in 1908 by Nettie Stevens.
Edward B. Lewis at Caltech discovered transvection at the bithorax complex in Drosophila in the 1950s. Since then, transvection has been observed at a number of additional loci in Drosophila, including white, decapentaplegic, eyes absent, vestigial, and yellow.
As stated by Ed Lewis, "Operationally, transvection is occurring if the phenotype of a given genotype can be altered solely by disruption of somatic (or meiotic) pairing. Such disruption can generally be accomplished by introduction of a heterozygous rearrangement that disrupts pairing in the relevant region but has no position effect of its own on the phenotype" (cited by Ting Wu and Jim Morris 1999). Recently, pairing-mediated phenomena have been observed in species other than Drosophila, including mice, humans, plants, nematodes, insects, and fungi. In light of these findings, transvection may represent a potent and widespread form of gene regulation.
Transvection appears to be dependent upon chromosome pairing. In some cases, if one allele
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https://en.wikipedia.org/wiki/Artin%20L-function
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In mathematics, an Artin L-function is a type of Dirichlet series associated to a linear representation ρ of a Galois group G. These functions were introduced in 1923 by Emil Artin, in connection with his research into class field theory. Their fundamental properties, in particular the Artin conjecture described below, have turned out to be resistant to easy proof. One of the aims of proposed non-abelian class field theory is to incorporate the complex-analytic nature of Artin L-functions into a larger framework, such as is provided by automorphic forms and the Langlands program. So far, only a small part of such a theory has been put on a firm basis.
Definition
Given , a representation of on a finite-dimensional complex vector space , where is the Galois group of the finite extension of number fields, the Artin -function: is defined by an Euler product. For each prime ideal in 's ring of integers, there is an Euler factor, which is easiest to define in the case where is unramified in (true for almost all ). In that case, the Frobenius element is defined as a conjugacy class in . Therefore, the characteristic polynomial of is well-defined. The Euler factor for is a slight modification of the characteristic polynomial, equally well-defined,
as rational function in t, evaluated at , with a complex variable in the usual Riemann zeta function notation. (Here N is the field norm of an ideal.)
When is ramified, and I is the inertia group which is a subgroup of G, a
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https://en.wikipedia.org/wiki/Quasinormal%20subgroup
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In mathematics, in the field of group theory, a quasinormal subgroup, or permutable subgroup, is a subgroup of a group that commutes (permutes) with every other subgroup with respect to the product of subgroups. The term quasinormal subgroup was introduced by Øystein Ore in 1937.
Two subgroups are said to permute (or commute) if any element from the first
subgroup, times an element of the second subgroup, can be written as an element of the second
subgroup, times an element of the first subgroup. That is, and
as subgroups of are said to commute if HK = KH, that is, any element of the form
with and can be written in the form
where and .
Every normal subgroup is quasinormal, because a normal subgroup commutes with every element of the group. The converse is not true. For instance, any extension of a cyclic -group by another cyclic -group for the same (odd) prime has the property that all its subgroups are quasinormal. However, not all of its subgroups need be normal.
Every quasinormal subgroup is a modular subgroup, that is, a modular element in the lattice of subgroups. This follows from the modular property of groups. If all subgroups are quasinormal, then the group is called an Iwasawa group—sometimes also called a modular group, although this latter term has other meanings.
In any group, every quasinormal subgroup is ascendant.
A conjugate permutable subgroup is one that commutes with all its conjugate subgroups. Every quasinormal subgroup is conjugate permutab
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https://en.wikipedia.org/wiki/Subnormal%20subgroup
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In mathematics, in the field of group theory, a subgroup H of a given group G is a subnormal subgroup of G if there is a finite chain of subgroups of the group, each one normal in the next, beginning at H and ending at G.
In notation, is -subnormal in if there are subgroups
of such that is normal in for each .
A subnormal subgroup is a subgroup that is -subnormal for some positive integer .
Some facts about subnormal subgroups:
A 1-subnormal subgroup is a proper normal subgroup (and vice versa).
A finitely generated group is nilpotent if and only if each of its subgroups is subnormal.
Every quasinormal subgroup, and, more generally, every conjugate-permutable subgroup, of a finite group is subnormal.
Every pronormal subgroup that is also subnormal, is normal. In particular, a Sylow subgroup is subnormal if and only if it is normal.
Every 2-subnormal subgroup is a conjugate-permutable subgroup.
The property of subnormality is transitive, that is, a subnormal subgroup of a subnormal
subgroup is subnormal. The relation of subnormality can be defined as the transitive closure of the relation of normality.
If every subnormal subgroup of G is normal in G, then G is called a T-group.
See also
Characteristic subgroup
Normal core
Normal closure
Ascendant subgroup
Descendant subgroup
Serial subgroup
References
Subgroup properties
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https://en.wikipedia.org/wiki/Degree%20of%20an%20algebraic%20variety
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In mathematics, the degree of an affine or projective variety of dimension is the number of intersection points of the variety
with hyperplanes in general position. For an algebraic set, the intersection points must be counted with their intersection multiplicity, because of the possibility of multiple components. For (irreducible) varieties, if one takes into account the multiplicities and, in the affine case, the points at infinity, the hypothesis of general position may be replaced by the much weaker condition that the intersection of the variety has the dimension zero (that is, consists of a finite number of points). This is a generalization of Bézout's theorem (For a proof, see ).
The degree is not an intrinsic property of the variety, as it depends on a specific embedding of the variety in an affine or projective space.
The degree of a hypersurface is equal to the total degree of its defining equation. A generalization of Bézout's theorem asserts that, if an intersection of projective hypersurfaces has codimension , then the degree of the intersection is the product of the degrees of the hypersurfaces.
The degree of a projective variety is the evaluation at of the numerator of the Hilbert series of its coordinate ring. It follows that, given the equations of the variety, the degree may be computed from a Gröbner basis of the ideal of these equations.
Definition
For V embedded in a projective space Pn and defined over some algebraically closed field K, the degr
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https://en.wikipedia.org/wiki/Quaternion%20algebra
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In mathematics, a quaternion algebra over a field F is a central simple algebra A over F that has dimension 4 over F. Every quaternion algebra becomes a matrix algebra by extending scalars (equivalently, tensoring with a field extension), i.e. for a suitable field extension K of F, is isomorphic to the 2 × 2 matrix algebra over K.
The notion of a quaternion algebra can be seen as a generalization of Hamilton's quaternions to an arbitrary base field. The Hamilton quaternions are a quaternion algebra (in the above sense) over , and indeed the only one over apart from the 2 × 2 real matrix algebra, up to isomorphism. When , then the biquaternions form the quaternion algebra over F.
Structure
Quaternion algebra here means something more general than the algebra of Hamilton's quaternions. When the coefficient field F does not have characteristic 2, every quaternion algebra over F can be described as a 4-dimensional F-vector space with basis , with the following multiplication rules:
where a and b are any given nonzero elements of F. From these rules we get:
The classical instances where are Hamilton's quaternions (a = b = −1) and split-quaternions (a = −1, b = +1). In split-quaternions, and , differing from Hamilton's equations.
The algebra defined in this way is denoted (a,b)F or simply (a,b). When F has characteristic 2, a different explicit description in terms of a basis of 4 elements is also possible, but in any event the definition of a quaternion algebra over F a
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https://en.wikipedia.org/wiki/Dense%20graph
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In mathematics, a dense graph is a graph in which the number of edges is close to the maximal number of edges (where every pair of vertices is connected by one edge). The opposite, a graph with only a few edges, is a sparse graph. The distinction of what constitutes a dense or sparse graph is ill-defined, and is often represented by 'roughly equal to' statements. Due to this, the way that density is defined often depends on the context of the problem.
The graph density of simple graphs is defined to be the ratio of the number of edges with respect to the maximum possible edges.
For undirected simple graphs, the graph density is:
For directed, simple graphs, the maximum possible edges is twice that of undirected graphs (as there are two directions to an edge) so the density is:
where is the number of edges and is the number of vertices in the graph. The maximum number of edges for an undirected graph is , so the maximal density is 1 (for complete graphs) and the minimal density is 0 .
For families of graphs of increasing size, one often calls them sparse if as . Sometimes, in computer science, a more restrictive definition of sparse is used like or even .
Upper density
Upper density is an extension of the concept of graph density defined above from finite graphs to infinite graphs. Intuitively, an infinite graph has arbitrarily large finite subgraphs with any density less than its upper density, and does not have arbitrarily large finite subgraphs with density great
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https://en.wikipedia.org/wiki/Extreme
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Extreme may refer to:
Science and mathematics
Mathematics
Extreme point, a point in a convex set which does not lie in any open line segment joining two points in the set
Maxima and minima, extremes on a mathematical function
Science
Extremophile, an organism which thrives in or requires "extreme"
Extremes on Earth
List of extrasolar planet extremes
Politics
Extremism, political ideologies or actions deemed outside the acceptable range
The Extreme (Italy) or Historical Far Left, a left-wing parliamentary group in Italy 1867–1904
Business
Extreme Networks, a California-based networking hardware company
Extreme Records, an Australia-based record label
Extreme Associates, a California-based adult film studio
Computer science
Xtreme Mod, a peer-to-peer file sharing client for Windows
Sports and entertainment
Sport
Extreme sport
Extreme Sports Channel A global sports and lifestyle brand dedicated to extreme sports and youth culture
Los Angeles Xtreme, a defunct XFL franchise
Buffalo eXtreme, an ABA franchise
Music
Extreme metal, an umbrella term for a group of related heavy metal subgenres
Extreme (band), an American band
Extreme (album), an album by Extreme
Xtreme (group), a bachata duo
Xtreme (album), an album by Xtreme
Extremes (album), an album by Collin Raye
X-Treme, a stage name of Italian singer and producer Agostino Carollo
Entertainment
Extreme Sports Channel, a global TV channel dedicated to extreme sports and youth culture
RTL CBS Extreme, a Southeast Asian
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https://en.wikipedia.org/wiki/Spin%20tensor
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In mathematics, mathematical physics, and theoretical physics, the spin tensor is a quantity used to describe the rotational motion of particles in spacetime. The spin tensor has application in
general relativity and special relativity, as well as quantum mechanics, relativistic quantum mechanics, and quantum field theory.
The special Euclidean group SE(d) of direct isometries is generated by translations and rotations. Its Lie algebra is written .
This article uses Cartesian coordinates and tensor index notation.
Background on Noether currents
The Noether current for translations in space is momentum, while the current for increments in time is energy. These two statements combine into one in spacetime: translations in spacetime, i.e. a displacement between two events, is generated by the four-momentum P. Conservation of four-momentum is given by the continuity equation:
where is the stress–energy tensor, and ∂ are partial derivatives that make up the four-gradient (in non-Cartesian coordinates this must be replaced by the covariant derivative). Integrating over space:
gives the four-momentum vector at time t.
The Noether current for a rotation about the point y is given by a tensor of 3rd order, denoted . Because of the Lie algebra relations
where the 0 subscript indicates the origin (unlike momentum, angular momentum depends on the origin), the integral:
gives the angular momentum tensor at time t.
Definition
The spin tensor is defined at a point x to be the
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https://en.wikipedia.org/wiki/Robert%20G.%20W.%20Anderson
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Robert Geoffrey William Anderson, (born 2 May 1944) is a British museum curator and historian of chemistry. He has wide-ranging interests in the history of chemistry, including the history of scientific instrumentation, the work of Joseph Black and Joseph Priestley, the history of museums, and the involvement of the working class in material culture. He has been Director of the Science Museum, London, the National Museums of Scotland, the British Museum, London, and president and CEO of the Chemical Heritage Foundation (now the Science History Institute) in Philadelphia.
Education
Anderson was born 2 May 1944 to Herbert Patrick Anderson and Kathleen Diana Burns. Anderson was educated at Woodhouse Grammar School, a former state grammar school in Finchley in North London, followed by St John's College at the University of Oxford. He completed his B.A. in chemistry in 1966, and his B.Sc., and his Doctor of Philosophy (D. Phil.) in 1970. He studied the electrical conduction in free radical solutions and inelastic scattering of neutrons from adsorbed molecules.
Life and career
Anderson joined the Royal Scottish Museum as an Assistant Keeper in 1970. In 1975, he moved to the chemistry department of the Science Museum, London. He became an Assistant Keeper of Chemistry. One of his challenges in 1976 was to incorporate materials from the history of medicine collection of the Wellcome Museum of the History of Medicine, which were acquired as a permanent loan. He organized a co
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https://en.wikipedia.org/wiki/Mario%20Garavaglia
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Mario Garavaglia (born 1937) is an Argentine physicist.
Biography
He was born in Junín (Buenos Aires Province, Argentina) in 1937.
In 1999 the International Commission for Optics awarded him the Galileo Galilei Award by unanimous vote for his work on lasers and their applications in industry, medicine and biology and for promoting optics in Latin America.
In 2004 he received the Houssay Career Award.
References
External links
1937 births
Living people
20th-century Argentine physicists
People from Junín, Buenos Aires
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https://en.wikipedia.org/wiki/Quintuple%20bond
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A quintuple bond in chemistry is an unusual type of chemical bond, first reported in 2005 for a dichromium compound. Single bonds, double bonds, and triple bonds are commonplace in chemistry. Quadruple bonds are rarer and are currently known only among the transition metals, especially for Cr, Mo, W, and Re, e.g. [Mo2Cl8]4− and [Re2Cl8]2−. In a quintuple bond, ten electrons participate in bonding between the two metal centers, allocated as σ2π4δ4.
In some cases of high-order bonds between metal atoms, the metal-metal bonding is facilitated by ligands that link the two metal centers and reduce the interatomic distance. By contrast, the chromium dimer with quintuple bonding is stabilized by a bulky terphenyl (2,6-[(2,6-diisopropyl)phenyl]phenyl) ligands. The species is stable up to 200 °C. The chromium–chromium quintuple bond has been analyzed with multireference ab initio and DFT methods, which were also used to elucidate the role of the terphenyl ligand, in which the flanking aryls were shown to interact very weakly with the chromium atoms, causing only a small weakening of the quintuple bond. A 2007 theoretical study identified two global minima for quintuple bonded RMMR compounds: a trans-bent molecular geometry and surprisingly another trans-bent geometry with the R substituent in a bridging position.
In 2005, a quintuple bond was postulated to exist in the hypothetical uranium molecule U2 based on computational chemistry. Diuranium compounds are rare, but do exist; for
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https://en.wikipedia.org/wiki/Antagonism
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Antagonism may refer to:
The characteristic of an antagonist
Antagonism (chemistry), where the involvement of multiple agents reduces their overall effect
Receptor antagonist or pharmacological antagonist, a substance that binds to the site an agonist would bind to, without causing activation
Antagonism (phytopathology), an effect that suppresses the activity of a plant pathogen
Reflexive antagonism of muscles
Intraspecific antagonism, disharmonious or antagonistic interaction between two individuals of the same species
See also
Antagonist (disambiguation)
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https://en.wikipedia.org/wiki/Facultad%20de%20Ciencias%20Exactas%2C%20Ingenier%C3%ADa%20y%20Agrimensura%20%28UNR%29
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The Faculty of Exact Sciences, Engineering and Surveying (Facultad de Ciencias Exactas, Ingeniería y Agrimensura) of the National University of Rosario (UNR) is an institution of higher learning in Rosario, Argentina.
Description
The faculty consists of the Institute of Mechanical systems, Institute of Geology, Institute of Mathematics and the Institute of Physics. The faculty shares its main campus, located on Pellegrini Avenue (Rosario), with the Instituto Politécnico Superior, a high school that is also affiliated with the UNR.
Courses
As of 2019, the Faculty offers 11 graduate degree programs: six are in Engineering, Civil engineering, Electrical engineering, Electronics engineering, Industrial engineering and Mechanical engineering.
Three offer Licenciate titles in Physics, Mathematics and Computer science, and there are a Professorship of Mathematics and a Professorship of Physics. It also provides post-graduate courses and long-distance education in Surveying (agrimensura).
Laboratories
There are numerous laboratories, namely for Metallurgy, Hydraulics, Acoustics, Infomatics, Thermodynamics, Physics, Microelectronics, Chemistry and Microbiology, Electric machines, Electric material and Meteorology.
the college's undated website listed the following 23 laboratory names:
Acoustics and Electro acoustics Laboratory,
Standards Testing Laboratory,
Laboratorio de ensayos, investigación y desarrollos eléctricos (LEIDE),
Structures Laboratory,
Extension Laboratory – S
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https://en.wikipedia.org/wiki/ABINIT
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ABINIT is an open-source suite of programs for materials science, distributed under the GNU General Public License. ABINIT implements density functional theory, using a plane wave basis set and pseudopotentials, to compute the electronic density and derived properties of materials ranging from molecules to surfaces to solids. It is developed collaboratively by researchers throughout the world.
A web-based easy-to-use graphical version, which includes access to a limited set of ABINIT's full functionality, is available for free use through the nanohub.
The latest version 9.10.3 was released on June 24, 2023.
Overview
ABINIT implements density functional theory by solving the Kohn–Sham equations describing the electrons in a material, expanded in a plane wave basis set and using a self-consistent conjugate gradient method to determine the energy minimum. Computational efficiency is achieved through the use of fast Fourier transforms, and pseudopotentials to describe core electrons. As an alternative to standard norm-conserving pseudopotentials, the projector augmented-wave method may be used. In addition to total energy, forces and stresses are also calculated so that geometry optimizations and ab initio molecular dynamics may be carried out. Materials that can be treated by ABINIT include insulators, metals, and magnetically ordered systems including Mott-Hubbard insulators.
Derived properties
In addition to computing the electronic ground state of materials, ABINIT impleme
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https://en.wikipedia.org/wiki/Arunas%20Rudvalis
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Arunas Rudvalis (born June 8, 1945) is an Emeritus Professor of Mathematics at the University of Massachusetts Amherst. He is best known for the Rudvalis group.
Rudvalis went to the Harvey Mudd College and received his Ph.D. degree in Dartmouth College under direction of Ernst Snapper.
External links
Arunas Rudvalis's Web Page
1945 births
20th-century American mathematicians
21st-century American mathematicians
Harvey Mudd College alumni
Dartmouth College alumni
University of Massachusetts Amherst faculty
Living people
Place of birth missing (living people)
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https://en.wikipedia.org/wiki/PPU
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PPU may refer to:
Education
Palestine Polytechnic University, Hebron, West Bank
Patliputra University, Patna, India
Point Park University, Pittsburgh, Pennsylvania, US
Science and technology
Physics processing unit, a microprocessor typically used for video games
Picture Processing Unit, the component which generates a video signal in the Nintendo Entertainment System
Power processing unit, a component responsible for regulating electrical power
Other uses
PPU (union), a defunct British pilots' union
Papun Airport, Papun, Myanmar (IATA airport code)
Peace Pledge Union, a British anti-war organisation
People's Protection Units, armed forces of the Kurdish Supreme Committee
Peoria and Pekin Union Railway, Illinois, US
Pirate Party of Ukraine, a political party
The Plastic People of the Universe, a Czech rock band
Price per unit
Prvi Partizan (Prvi Partizan zavod ad Užice), a Serbian ammunition manufacturer.
See also
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https://en.wikipedia.org/wiki/Ergodic%20flow
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In mathematics, ergodic flows occur in geometry, through the geodesic and horocycle flows of closed hyperbolic surfaces. Both of these examples have been understood in terms of the theory of unitary representations of locally compact groups: if Γ is the fundamental group of a closed surface, regarded as a discrete subgroup of the Möbius group G = PSL(2,R), then the geodesic and horocycle flow can be identified with the natural actions of the subgroups A of real positive diagonal matrices and N of lower unitriangular matrices on the unit tangent bundle G / Γ. The Ambrose-Kakutani theorem expresses every ergodic flow as the flow built from an invertible ergodic transformation on a measure space using a ceiling function. In the case of geodesic flow, the ergodic transformation can be understood in terms of symbolic dynamics; and in terms of the ergodic actions of Γ on the boundary S1 = G / AN and G / A = S1 × S1 \ diag S1. Ergodic flows also arise naturally as invariants in the classification of von Neumann algebras: the flow of weights for a factor of type III0 is an ergodic flow on a measure space.
Hedlund's theorem: ergodicity of geodesic and horocycle flows
The method using representation theory relies on the following two results:
If = acts unitarily on a Hilbert space and is a unit vector fixed by the subgroup of upper unitriangular matrices, then is fixed by .
If = acts unitarily on a Hilbert space and is a unit vector fixed by the subgroup of diagonal mat
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https://en.wikipedia.org/wiki/Rigidity%20theory
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Rigidity theory may refer to
Study of the concept of rigidity (mathematics)
Mathematical theory of structural rigidity
Rigidity theory (physics), or topological constraints theory, describes or predicts the mechanical properties of glass
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https://en.wikipedia.org/wiki/Mostow%20rigidity%20theorem
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In mathematics, Mostow's rigidity theorem, or strong rigidity theorem, or Mostow–Prasad rigidity theorem, essentially states that the geometry of a complete, finite-volume hyperbolic manifold of dimension greater than two is determined by the fundamental group and hence unique. The theorem was proven for closed manifolds by and extended to finite volume manifolds by in 3 dimensions, and by in all dimensions at least 3. gave an alternate proof using the Gromov norm. gave the simplest available proof.
While the theorem shows that the deformation space of (complete) hyperbolic structures on a finite volume hyperbolic -manifold (for ) is a point, for a hyperbolic surface of genus there is a moduli space of dimension that parameterizes all metrics of constant curvature (up to diffeomorphism), a fact essential for Teichmüller theory. There is also a rich theory of deformation spaces of hyperbolic structures on infinite volume manifolds in three dimensions.
The theorem
The theorem can be given in a geometric formulation (pertaining to finite-volume, complete manifolds), and in an algebraic formulation (pertaining to lattices in Lie groups).
Geometric form
Let be the -dimensional hyperbolic space. A complete hyperbolic manifold can be defined as a quotient of by a group of isometries acting freely and properly discontinuously (it is equivalent to define it as a Riemannian manifold with sectional curvature -1 which is complete). It is of finite volume if the integral o
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https://en.wikipedia.org/wiki/National%20Association%20of%20Biology%20Teachers
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The National Association of Biology Teachers (NABT) is an incorporated association of biology educators in the United States. It was initially founded in response to the poor understanding of biology and the decline in the teaching of the subject in the 1930s. It has grown to become a national representative organisation which promotes the teaching of biology, supports the learning of biology based on scientific principles and advocates for biology within American society. The National Conference and the journal, The American Biology Teacher, are two mechanisms used to achieve those goals.
The NABT has also been an advocate for the teaching of evolution in the debate about creation and evolution in public education in the United States, playing a role in a number of court cases and hearings throughout the country.
History
The NABT was formed in 1938 in New York City. The journal of the organisation (The American Biology Teacher) was created in the same year.
In 1944, Helen Trowbridge, the first female president, was elected. The Outstanding Teacher Awards were first presented in 1960 and the first independent National Convention was held in 1968.
The seventies marked an era of activism in the teaching of evolution with legal action against a state code amendment in Tennessee which required equal amounts of time to teach evolution and creationism.
In 1987 NABT helped develop the first National High School Biology test which established a list of nine core principles in the t
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https://en.wikipedia.org/wiki/Lefschetz%20pencil
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In mathematics, a Lefschetz pencil is a construction in algebraic geometry considered by Solomon Lefschetz, used to analyse the algebraic topology of an algebraic variety V.
Description
A pencil is a particular kind of linear system of divisors on V, namely a one-parameter family, parametrised by the projective line. This means that in the case of a complex algebraic variety V, a Lefschetz pencil is something like a fibration over the Riemann sphere; but with two qualifications about singularity.
The first point comes up if we assume that V is given as a projective variety, and the divisors on V are hyperplane sections. Suppose given hyperplanes H and H′, spanning the pencil — in other words, H is given by L = 0 and H′ by L′= 0 for linear forms L and L′, and the general hyperplane section is V intersected with
Then the intersection J of H with H′ has codimension two. There is a rational mapping
which is in fact well-defined only outside the points on the intersection of J with V. To make a well-defined mapping, some blowing up must be applied to V.
The second point is that the fibers may themselves 'degenerate' and acquire singular points (where Bertini's lemma applies, the general hyperplane section will be smooth). A Lefschetz pencil restricts the nature of the acquired singularities, so that the topology may be analysed by the vanishing cycle method. The fibres with singularities are required to have a unique quadratic singularity, only.
It has been shown that Lefs
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https://en.wikipedia.org/wiki/Rational%20mapping
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In mathematics, in particular the subfield of algebraic geometry, a rational map or rational mapping is a kind of partial function between algebraic varieties. This article uses the convention that varieties are irreducible.
Definition
Formal definition
Formally, a rational map between two varieties is an equivalence class of pairs in which is a morphism of varieties from a non-empty open set to , and two such pairs and are considered equivalent if and coincide on the intersection (this is, in particular, vacuously true if the intersection is empty, but since is assumed irreducible, this is impossible). The proof that this defines an equivalence relation relies on the following lemma:
If two morphisms of varieties are equal on some non-empty open set, then they are equal.
is said to be birational if there exists a rational map which is its inverse, where the composition is taken in the above sense.
The importance of rational maps to algebraic geometry is in the connection between such maps and maps between the function fields of and . Even a cursory examination of the definitions reveals a similarity between that of rational map and that of rational function; in fact, a rational function is just a rational map whose range is the projective line. Composition of functions then allows us to "pull back" rational functions along a rational map, so that a single rational map induces a homomorphism of fields . In particular, the following theorem is central: t
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https://en.wikipedia.org/wiki/HEPnet
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HEPnet or the High-Energy Physics Network is a telecommunications network for researchers in high-energy physics. It originated in the United States, but that has spread to most places involved in such research. Well-known sites include Argonne National Laboratory, Brookhaven National Laboratory and Lawrence Berkeley.
See also
Energy Sciences Network
External links
HEPnet site
Computational particle physics
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https://en.wikipedia.org/wiki/Complex%20dimension
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In mathematics, complex dimension usually refers to the dimension of a complex manifold or a complex algebraic variety. These are spaces in which the local neighborhoods of points (or of non-singular points in the case of a variety) are modeled on a Cartesian product of the form for some , and the complex dimension is the exponent in this product. Because can in turn be modeled by , a space with complex dimension will have real dimension . That is, a smooth manifold of complex dimension has real dimension ; and a complex algebraic variety of complex dimension , away from any singular point, will also be a smooth manifold of real dimension .
However, for a real algebraic variety (that is a variety defined by equations with real coefficients), its dimension refers commonly to its complex dimension, and its real dimension refers to the maximum of the dimensions of the manifolds contained in the set of its real points. The real dimension is not greater than the dimension, and equals it if the variety is irreducible and has real points that are nonsingular.
For example, the equation defines a variety of (complex) dimension 2 (a surface), but of real dimension 0 — it has only one real point, (0, 0, 0), which is singular.
The same considerations apply to codimension. For example a smooth complex hypersurface in complex projective space of dimension n will be a manifold of dimension 2(n − 1). A complex hyperplane does not separate a complex projective space into two compone
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https://en.wikipedia.org/wiki/Constant%20sheaf
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In mathematics, the constant sheaf on a topological space associated to a set is a sheaf of sets on whose stalks are all equal to . It is denoted by or . The constant presheaf with value is the presheaf that assigns to each open subset of the value , and all of whose restriction maps are the identity map . The constant sheaf associated to is the sheafification of the constant presheaf associated to . This sheaf identifies with the sheaf of locally constant -valued functions on .
In certain cases, the set may be replaced with an object in some category (e.g. when is the category of abelian groups, or commutative rings).
Constant sheaves of abelian groups appear in particular as coefficients in sheaf cohomology.
Basics
Let be a topological space, and a set. The sections of the constant sheaf over an open set may be interpreted as the continuous functions , where is given the discrete topology. If is connected, then these locally constant functions are constant. If is the unique map to the one-point space and is considered as a sheaf on , then the inverse image is the constant sheaf on . The sheaf space of is the projection map (where is given the discrete topology).
A detailed example
Let be the topological space consisting of two points and with the discrete topology. has four open sets: . The five non-trivial inclusions of the open sets of are shown in the chart.
A presheaf on chooses a set for each of the four open sets of and a restrict
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https://en.wikipedia.org/wiki/Kazimierz%20Marcinkiewicz
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Kazimierz Marcinkiewicz (; born 20 December 1959) is a Polish conservative politician who served as Prime Minister of Poland from 31 October 2005 to 14 July 2006. He was a member of the Law and Justice party (Prawo i Sprawiedliwość, PiS).
Early life
Born in Gorzów Wielkopolski, Marcinkiewicz graduated in 1984 from the Faculty of Mathematics, Physics and Chemistry (having studied physics) of the Wrocław University. He also completed post-graduate course in Administration at the Adam Mickiewicz University in Poznań. He worked as an elementary school teacher and a headmaster in his homecity of Gorzów Wielkopolski.
In the 1980s he was also a member of the Solidarity movement and editor of underground press materials. In 1992 he became a State Secretary (formal name for deputy minister) in the Ministry of National Education. From 1999 to 2000 he was the cabinet chief for Prime Minister Jerzy Buzek.
Prime Minister of Poland
Following the victory of the Law and Justice party in the September 2005 Polish parliamentary elections, its prime ministerial candidate, party leader Jarosław Kaczyński decided against becoming prime minister so as not to damage the chances of his twin brother, Lech Kaczyński in the then-upcoming October presidential election. Instead the little-known Marcinkiewicz became PM, leading a coalition formed by Jarosław, who remained in the background, but influential.
Before his prime ministerial appointment, Marcinkiewicz remained a political cipher, which r
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https://en.wikipedia.org/wiki/Escuela%20Superior%20Latinoamericana%20de%20Inform%C3%A1tica
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The Escuela Superior Latinoamericana de Informática (Spanish for "Latin American Superior School of Informatics", ESLAI) was an Argentine undergraduate school of computer science established in 1986. Classes were held in a former country house at the Pereyra Iraola Park in Buenos Aires Province, located approximately 40 km from Buenos Aires.
The school had Argentine mathematician Manuel Sadosky among its main founders. In spite of its short life, it had a considerable impact on informatics teaching and research in Argentina and South America. ESLAI courses were attended by students from several Spanish-speaking countries in South America such as Argentina, Uruguay, Paraguay, Bolivia, Peru, Ecuador, Colombia, and Venezuela. All students had a full scholarship and the admission process was passed by about 15% of applicants.
ESLAI established cooperation programs with a number of foreign universities in the Americas as well as in Europe. Those agreements sponsored important visitors to the school, such as Alberto O. Mendelzon, Jean-Raymond Abrial, Ugo Montanari, Carlo Ghezzi and Giorgio Ausiello, and enabled its students to attend graduate school at foreign universities.
The school had a significant European influence and was oriented towards theoretical aspects of computer science, such as typed lambda calculus, formal verification, and Martin-Löf's intuitionistic type theory.
Unfortunately, ESLAI was never able to develop a relationship with local companies, which in an em
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https://en.wikipedia.org/wiki/Poincar%C3%A9%E2%80%93Bendixson%20theorem
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In mathematics, the Poincaré–Bendixson theorem is a statement about the long-term behaviour of orbits of continuous dynamical systems on the plane, cylinder, or two-sphere.
Theorem
Given a differentiable real dynamical system defined on an open subset of the plane, every non-empty compact ω-limit set of an orbit, which contains only finitely many fixed points, is either
a fixed point,
a periodic orbit, or
a connected set composed of a finite number of fixed points together with homoclinic and heteroclinic orbits connecting these.
Moreover, there is at most one orbit connecting different fixed points in the same direction. However, there could be countably many homoclinic orbits connecting one fixed point.
A weaker version of the theorem was originally conceived by , although he lacked a complete proof which was later given by .
Discussion
The condition that the dynamical system be on the plane is necessary to the theorem. On a torus, for example, it is possible to have a recurrent non-periodic orbit.
In particular, chaotic behaviour can only arise in continuous dynamical systems whose phase space has three or more dimensions. However the theorem does not apply to discrete dynamical systems, where chaotic behaviour can arise in two- or even one-dimensional systems.
Applications
One important implication is that a two-dimensional continuous dynamical system cannot give rise to a strange attractor. If a strange attractor C did exist in such a system, then it could be e
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https://en.wikipedia.org/wiki/Larmor%20precession
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In physics, Larmor precession (named after Joseph Larmor) is the precession of the magnetic moment of an object about an external magnetic field. The phenomenon is conceptually similar to the precession of a tilted classical gyroscope in an external torque-exerting gravitational field. Objects with a magnetic moment also have angular momentum and effective internal electric current proportional to their angular momentum; these include electrons, protons, other fermions, many atomic and nuclear systems, as well as classical macroscopic systems. The external magnetic field exerts a torque on the magnetic moment,
where is the torque, is the magnetic dipole moment, is the angular momentum vector, is the external magnetic field, symbolizes the cross product, and is the gyromagnetic ratio which gives the proportionality constant between the magnetic moment and the angular momentum.
The angular momentum vector precesses about the external field axis with an angular frequency known as the Larmor frequency,
,
where is the angular frequency, and
is the magnitude of the applied magnetic field.
is (for a particle of charge ) the gyromagnetic ratio, equal to , where is the mass of the precessing system, while is the g-factor of the system. The g-factor is the unit-less proportionality factor relating the system's angular momentum to the intrinsic magnetic moment; in classical physics it is just 1. The Larmor frequency is independent of the angle between and .
In nuclea
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https://en.wikipedia.org/wiki/Mixed%20boundary%20condition
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In mathematics, a mixed boundary condition for a partial differential equation defines a boundary value problem in which the solution of the given equation is required to satisfy different boundary conditions on disjoint parts of the boundary of the domain where the condition is stated. Precisely, in a mixed boundary value problem, the solution is required to satisfy a Dirichlet or a Neumann boundary condition in a mutually exclusive way on disjoint parts of the boundary.
For example, given a solution to a partial differential equation on a domain with boundary , it is said to satisfy a mixed boundary condition if, consisting of two disjoint parts, and , such that , verifies the following equations:
and
where and are given functions defined on those portions of the boundary.
The mixed boundary condition differs from the Robin boundary condition in that the latter requires a linear combination, possibly with pointwise variable coefficients, of the Dirichlet and the Neumann boundary value conditions to be satisfied on the whole boundary of a given domain.
Historical note
The first boundary value problem satisfying a mixed boundary condition was solved by Stanisław Zaremba for the Laplace equation: according to himself, it was Wilhelm Wirtinger who suggested him to study this problem.
See also
Dirichlet boundary condition
Neumann boundary condition
Cauchy boundary condition
Robin boundary condition
Notes
References
. In the paper "Existential analysis of the solu
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https://en.wikipedia.org/wiki/Martin%20Davies%20%28museum%20director%29
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Sir Martin Davies, CBE FBA FSA (22 March 1908 – 7 March 1975) was a British museum director and civil servant. He worked at the National Gallery in London from 1930 to 1973, and was Director from 1968.
Davies attended Rugby School, and thereafter read mathematics and modern languages at King's College, Cambridge. He first joined the staff of the National Gallery, the institution to which he was to devote his career, as an attaché in 1930. After being made Assistant Keeper in 1932 he called for improved research on the paintings in the collection, which would eventually come to fruition in the series of catalogues inaugurated by Davies and still being produced by the Gallery today. These set new standards for the catalogues of large collections, and have been widely imitated.
His scholarly work was interrupted from 1938 to 1941 by the need to find a safe home for the National Gallery's paintings at the onset of the Second World War, away from the aerial bombardment of London. After the artworks were safely transferred to Manod Quarry near Ffestiniog, North Wales, Davies was able to make his research in total seclusion. The catalogues for the Netherlandish, French, and British schools of painting were published from 1945 to 1946. The much larger Catalogue of the Earlier Italian Schools was published in 1961. Many of these paintings are now covered by published volumes of the new series of catalogues, but for example, only the 17th century French paintings are covered und
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https://en.wikipedia.org/wiki/Figure%208
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Figure 8 (figure of 8 in British English) may refer to:
8 (number), in Arabic numerals
Geography
Figure Eight Island, North Carolina, United States
Figure Eight Lake, Alberta, Canada
Figure-Eight Loops, feature of the Historic Columbia River Highway in Guy W. Talbot State Park
Mathematics and sciences
∞, symbol meaning infinity
Figure 8, a two-lobed Lissajous curve
Figure 8, in topology, the rose with two petals
Figure 8, shape described by an analemma, a curve in astronomy
Figure-eight knot (mathematics), in knot theory
Lemniscate, various types of mathematical curve that resembles a figure 8
Music
Albums and EPs
Figure 8 (album), a 2000 album by Elliott Smith
"Figure of Eight" (song), a 1989 song by Paul McCartney
Figure Eight EP, a 2008 EP by This Et Al
"Figure 8" (song), a 2012 song by Ellie Goulding from Halcyon
Songs
"Figure 8", a song by FKA Twigs from the EP M3LL155X
"Figure 8", a song by Paramore from the album This Is Why
"Figure Eight", a song and episode name from the children's educational series Schoolhouse Rock!
"Figure of Eight", song by Status Quo from In Search of the Fourth Chord
Ropes
Figure eight bend or Flemish bend, a knot
Figure-eight knot, typically used as a stopper knot
Figure-eight loop, figure of eight knot tied "on the bight"
Sport and leisure
Figure 8 racing, a category of auto racing related to the demolition derby
Figure 8 roller coaster, a track design
Figure 8, shape from which compulsory figures in ice
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https://en.wikipedia.org/wiki/Mass%20spectrometry%20data%20format
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Mass spectrometry is a scientific technique for measuring the mass-to-charge ratio of ions. It is often coupled to chromatographic techniques such as gas- or liquid chromatography and has found widespread adoption in the fields of analytical chemistry and biochemistry where it can be used to identify and characterize small molecules and proteins (proteomics). The large volume of data produced in a typical mass spectrometry experiment requires that computers be used for data storage and processing. Over the years, different manufacturers of mass spectrometers have developed various proprietary data formats for handling such data which makes it difficult for academic scientists to directly manipulate their data. To address this limitation, several open, XML-based data formats have recently been developed by the Trans-Proteomic Pipeline at the Institute for Systems Biology to facilitate data manipulation and innovation in the public sector. These data formats are described here.
Open formats
JCAMP-DX
This format was one of the earliest attempts to supply a standardized file format for data exchange in mass spectrometry. JCAMP-DX was initially developed for infrared spectrometry. JCAMP-DX is an ASCII based format and therefore not very compact even though it includes standards for file compression. JCAMP was officially released in 1988. Together with the American Society for Mass Spectrometry a JCAMP-DX format for mass spectrometry was developed with aim to preserve legacy data
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https://en.wikipedia.org/wiki/Dmitry%20Dubyago
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Dmitry Ivanovich Dubyago (Дмитрий Иванович Дубяго in Russian) (September 21 (N.S. October 3), 1849 – October 22, 1918) was a Russian astronomer and expert in theoretical astrophysics, astrometry, and gravimetry. A crater on the Moon is named after Dmitry Dubyago.
See also
Alexander Dubyago
crater Dubyago
References
Astronomers from the Russian Empire
1849 births
1918 deaths
Privy Councillor (Russian Empire)
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https://en.wikipedia.org/wiki/Stream%20processing
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In computer science, stream processing (also known as event stream processing, data stream processing, or distributed stream processing) is a programming paradigm which views streams, or sequences of events in time, as the central input and output objects of computation. Stream processing encompasses dataflow programming, reactive programming, and distributed data processing. Stream processing systems aim to expose parallel processing for data streams and rely on streaming algorithms for efficient implementation. The software stack for these systems includes components such as programming models and query languages, for expressing computation; stream management systems, for distribution and scheduling; and hardware components for acceleration including floating-point units, graphics processing units, and field-programmable gate arrays.
The stream processing paradigm simplifies parallel software and hardware by restricting the parallel computation that can be performed. Given a sequence of data (a stream), a series of operations (kernel functions) is applied to each element in the stream. Kernel functions are usually pipelined, and optimal local on-chip memory reuse is attempted, in order to minimize the loss in bandwidth, associated with external memory interaction. Uniform streaming, where one kernel function is applied to all elements in the stream, is typical. Since the kernel and stream abstractions expose data dependencies, compiler tools can fully automate and optimize
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https://en.wikipedia.org/wiki/Alexander%20Dubyago
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Alexander Dmitriyevich Dubyago (Александр Дмитриевич Дубяго in Russian) (December 5(18), 1903, Kazan - October 29, 1959, Kazan) was a Soviet astronomer and expert in theoretical astrophysics. The lunar crater Dubyago is named after him and his father, Dmitry Ivanovich Dubyago.
References
1903 births
1959 deaths
Scientists from Kazan
Soviet astronomers
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https://en.wikipedia.org/wiki/Schwartz%E2%80%93Zippel%20lemma
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In mathematics, the Schwartz–Zippel lemma (also called the DeMillo–Lipton–Schwartz–Zippel lemma) is a tool commonly used in probabilistic polynomial identity testing, i.e. in the problem of determining whether a given multivariate polynomial is the
0-polynomial (or identically equal to 0). It was discovered independently by Jack Schwartz, Richard Zippel, and Richard DeMillo and Richard J. Lipton, although DeMillo and Lipton's version was shown a year prior to Schwartz and Zippel's result. The finite field version of this bound was proved by Øystein Ore in 1922.
Statement and proof of the lemma
Theorem 1 (Schwartz, Zippel). Let
be a non-zero polynomial of total degree over an integral domain R. Let S be a finite subset of R and let be selected at random independently and uniformly from S. Then
Equivalently, the Lemma states that for any finite subset S of R, if Z(P) is the zero set of P, then
Proof. The proof is by mathematical induction on n. For , as was mentioned before, P can have at most d roots. This gives us the base case.
Now, assume that the theorem holds for all polynomials in variables. We can then consider P to be a polynomial in x1 by writing it as
Since is not identically 0, there is some such that is not identically 0. Take the largest such . Then , since the degree of is at most d.
Now we randomly pick from . By the induction hypothesis,
If , then is of degree (and thus not identically zero) so
If we denote the event by ,
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https://en.wikipedia.org/wiki/Multiphysics%20simulation
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In computational modelling, multiphysics simulation (often shortened to simply "multiphysics") is defined as the simultaneous simulation of different aspects of a physical system or systems and the interactions among them. For example, simultaneous simulation of the physical stress on an object, the temperature distribution of the object and the thermal expansion which leads to the variation of the stress and temperature distributions would be considered a multiphysics simulation. Multiphysics simulation is related to multiscale simulation, which is the simultaneous simulation of a single process on either multiple time or distance scales.
As an interdisciplinary field, multiphysics simulation can span many science and engineering disciplines. Simulation methods frequently include numerical analysis, partial differential equations and tensor analysis.
Multiphysics simulation process
The implementation of a multiphysics simulation follows a typical series of steps:
Identify the aspects of the system to be simulated, including physical processes, starting conditions, and the coupling or boundary conditions among these processes.
Create a discrete mathematical model of the system.
Numerically solve the model.
Process the resulting data.
Mathematical models
Mathematical models used in multiphysics simulations are generally a set of coupled equations. The equations can be divided into three categories according to the nature and intended role: governing equation, auxil
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https://en.wikipedia.org/wiki/Paul%20Sally
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Paul Joseph Sally, Jr. (January 29, 1933 – December 30, 2013) was a professor of mathematics at the University of Chicago, where he was the director of undergraduate studies for 30 years. His research areas were p-adic analysis and representation theory.
He created several programs to improve the preparation of school mathematics teachers, and was seen by many as "a legendary math professor at the University of Chicago."
Life and education
Sally was born in the Roslindale neighborhood of Boston, Massachusetts on January 29, 1933. He was a star basketball player at Boston College High School. He received his BS and MS degrees from Boston College in 1954 and 1956.
After a short career in Boston area high schools and at Boston College he entered the first class of mathematics graduate students at Brandeis in 1957 and earned his PhD in 1965. During his graduate career he married Judith D. Sally and had three children in three years. David, the oldest, is a Visiting Associate Professor of Business Administration at Tuck School of Business at Dartmouth College, Stephen is a partner at Ropes & Gray, and Paul, the youngest, is Superintendent at New Trier High School.
Sally was diagnosed with type 1 diabetes in 1948. The condition resulted in his use of an eye patch and two prosthetic legs, which caused him to be widely referred to as "Professor Pirate," and "The Math Pirate" around the University of Chicago campus. He was known to detest cell phones in class and has destroyed s
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https://en.wikipedia.org/wiki/Keum%20Na-na
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Keum Nana (금나나, born 19 August 1983) is the winner of Miss Korea 2002. She participated in the Miss Universe pageant in 2003. She attended but dropped out of Kyungpook National University School of Medicine in pursuit of undergraduate studies at Harvard University. She graduated from Harvard University in 2008, where she majored in Biochemistry. She then earned her master's degree in nutritional science at Columbia University while preparing her U.S. medical school applications. Nana Keum graduated from Harvard's TH Chan School of Public Health with a dual-doctorate in nutrition and epidemiology in 2015. She is currently a postdoctoral fellow at the TH Chan School of Public Health under the mentorship of Edward Giovannucci. She has published numerous peer-reviewed research papers and specializes in meta-analyses.
She is the author of "Everyone Can Do It" and "Study Diary of Nana" (both in Korean).
External links
Official website
1983 births
Columbia University alumni
Harvard T.H. Chan School of Public Health alumni
Kyungpook National University alumni
Living people
Miss Korea winners
Miss Universe 2003 contestants
Na-na
South Korean Buddhists
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https://en.wikipedia.org/wiki/George%20Lusztig
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George Lusztig (born Gheorghe Lusztig; May 20, 1946) is a Romanian-born American mathematician and Abdun Nur Professor at the Massachusetts Institute of Technology (MIT). He was a Norbert Wiener Professor in the Department of Mathematics from 1999 to 2009.
Education and career
Born in Timișoara to a Hungarian-Jewish family, he did his undergraduate studies at the University of Bucharest, graduating in 1968. Later that year he left Romania for the United Kingdom, where he spent several months at the University of Warwick and Oxford University. In 1969 he moved to the United States, where he went to work for two years with Michael Atiyah at the Institute for Advanced Study in Princeton, New Jersey. He received his PhD in mathematics in 1971 after completing a doctoral dissertation, titled "Novikov's higher signature and families of elliptic operators", under the supervision of William Browder and Michael Atiyah.
Lusztig worked for almost seven years at the University of Warwick. His involvement at the university encompassed a Research Fellowship, (1971–72); lecturer in Mathematics, (1972–74); and Professor of Mathematics, (1974–78). In 1978, he accepted a chair at MIT.
Contributions
He is known for his work on representation theory, in particular for the objects closely related to algebraic groups, such as finite reductive groups, Hecke algebras, -adic groups, quantum groups, and Weyl groups. He essentially paved the way for modern representation theory. This has included fu
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https://en.wikipedia.org/wiki/Lawrence%20C.%20Evans
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Lawrence Craig Evans (born November 1, 1949) is an American mathematician and Professor of Mathematics at the University of California, Berkeley.
His research is in the field of nonlinear partial differential equations, primarily elliptic equations. In 2004, he shared the Leroy P. Steele Prize for Seminal Contribution to Research with Nicolai V. Krylov for their proofs, found independently, that solutions of concave, fully nonlinear, uniformly elliptic equations are . Evans also made significant contributions to the development of the theory of viscosity solutions of nonlinear equations, to the understanding of the Hamilton–Jacobi–Bellman equation arising in stochastic optimal control theory, and to the theory of harmonic maps. He is also well known as the author of the textbook Partial Differential Equations, which is considered as a standard introduction to the theory at the graduate level. His textbook Measure theory and fine properties of functions (coauthored with Ronald Gariepy), an exposition on Hausdorff measure, capacity, Sobolev functions, and sets of finite perimeter, is also widely cited.
Evans is an ISI highly cited researcher.
Biography
Lawrence Evans was born November 1, 1949 in Atlanta, Georgia. He received a BA from Vanderbilt University in 1971 and a PhD, with thesis advisor Michael G. Crandall, from the University of California, Los Angeles in 1975. From 1975 to 1980, he worked at the University of Kentucky; from 1980 to 1989, at the University of Maryla
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https://en.wikipedia.org/wiki/Egg%20drop
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Egg drop may refer to:
Egg drop competition, an experiment usually performed by students
Egg drop soup, a Chinese soup dish
Eggdrop, a popular IRC bot
Egg Drop, an episode of the television series Modern Family
Egg drop syndrome or EDS, a bird disease caused by an avian adenovirus
Egg dropping puzzle, a popular problem in mathematics and computer science
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https://en.wikipedia.org/wiki/Alatau%2C%20Kazakhstan
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Alatau (, Alatau; from Turkic languages: "motley mountain") is a town in Almaty Region, in south-eastern Kazakhstan, 15 km away from Almaty.
The town is notable for its Institute of Nuclear Physics, Kazakhstan National Nuclear Center (formerly of the Kazakh SSR Academy of Sciences), which houses an experimental nuclear reactor and cyclotron.
External links
Tageo.com
Populated places in Almaty Region
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https://en.wikipedia.org/wiki/Mixing%20ratio
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In chemistry and physics, the dimensionless mixing ratio is the abundance of one component of a mixture relative to that of all other components. The term can refer either to mole ratio (see concentration) or mass ratio (see stoichiometry).
In atmospheric chemistry and meteorology
Mole ratio
In atmospheric chemistry, mixing ratio usually refers to the mole ratio ri, which is defined as the amount of a constituent ni divided by the total amount of all other constituents in a mixture:
The mole ratio is also called amount ratio.
If ni is much smaller than ntot (which is the case for atmospheric trace constituents), the mole ratio is almost identical to the mole fraction.
Mass ratio
In meteorology, mixing ratio usually refers to the mass ratio of water , which is defined as the mass of water divided by the mass of dry air () in a given air parcel:
The unit is typically given in . The definition is similar to that of specific humidity.
Mixing ratio of mixtures or solutions
Two binary solutions of different compositions or even two pure components can be mixed with various mixing ratios by masses, moles, or volumes.
The mass fraction of the resulting solution from mixing solutions with masses m1 and m2 and mass fractions w1 and w2 is given by:
where m1 can be simplified from numerator and denominator
and
is the mass mixing ratio of the two solutions.
By substituting the densities ρi(wi) and considering equal volumes of different concentrations one gets:
Considering a
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https://en.wikipedia.org/wiki/Lifeworld
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Lifeworld (or life-world) () may be conceived as a universe of what is self-evident or given, a world that subjects may experience together. The concept was popularized by Edmund Husserl, who emphasized its role as the ground of all knowledge in lived experience. It has its origin in biology and cultural Protestantism.
The lifeworld concept is used in philosophy and in some social sciences, particularly sociology and anthropology. The concept emphasizes a state of affairs in which the world is experienced, the world is lived (German erlebt). The lifeworld is a pre-epistemological stepping stone for phenomenological analysis in the Husserlian tradition.
Phenomenology
Edmund Husserl introduced the concept of the lifeworld in his The Crisis of European Sciences and Transcendental Phenomenology (1936):
This collective inter-subjective pool of perceiving, Husserl explains, is both universally present and, for humanity's purposes, capable of arriving at 'objective truth,' or at least as close to objectivity as possible. The 'lifeworld' is a grand theatre of objects variously arranged in space and time relative to perceiving subjects, is already-always there, and is the "ground" for all shared human experience. Husserl's formulation of the lifeworld was also influenced by Wilhelm Dilthey's "life-nexus" (German Lebenszusammenhang) and Martin Heidegger's Being-in-the-world (German In-der-Welt-Sein). The concept was further developed by students of Husserl such as Maurice Merleau-P
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https://en.wikipedia.org/wiki/Solar%20physics
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Solar physics is the branch of astrophysics that specializes in the study of the Sun. It deals with detailed measurements that are possible only for our closest star. It intersects with many disciplines of pure physics, astrophysics, and computer science, including fluid dynamics, plasma physics including magnetohydrodynamics, seismology, particle physics, atomic physics, nuclear physics, stellar evolution, space physics, spectroscopy, radiative transfer, applied optics, signal processing, computer vision, computational physics, stellar physics and solar astronomy.
Because the Sun is uniquely situated for close-range observing (other stars cannot be resolved with anything like the spatial or temporal resolution that the Sun can), there is a split between the related discipline of observational astrophysics (of distant stars) and observational solar physics.
The study of solar physics is also important as it provides a "physical laboratory" for the study of plasma physics.
History
Ancient times
Babylonians were keeping a record of solar eclipses, with the oldest record originating from the ancient city of Ugarit, in modern-day Syria. This record dates to about 1300 BC. Ancient Chinese astronomers were also observing solar phenomena (such as solar eclipses and visible sunspots) with the purpose of keeping track of calendars, which were based on lunar and solar cycles. Unfortunately, records kept before 720 BC are very vague and offer no useful information. However, after 7
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https://en.wikipedia.org/wiki/Madhava%20of%20Sangamagrama
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Mādhava of Sangamagrāma (Mādhavan) () was an Indian mathematician and astronomer who is considered as the founder of the Kerala school of astronomy and mathematics. One of the greatest mathematician-astronomers of the Late Middle Ages, Madhava made pioneering contributions to the study of infinite series, calculus, trigonometry, geometry, and algebra. He was the first to use infinite series approximations for a range of trigonometric functions, which has been called the "decisive step onward from the finite procedures of ancient mathematics to treat their limit-passage to infinity".
Biography
Little is known about Mādhava's life with certainty. However, from scattered references to Mādhava found in diverse manuscripts, historians of Kerala school have pieced together informations about the mathematician. In a manuscript preserved in the Oriental Institute, Baroda, Madhava has been referred to as Mādhavan vēṇvārōhādīnām karttā ... Mādhavan Ilaññippaḷḷi Emprān. It has been noted that the epithet 'Emprān' refers to the Emprāntiri community, to which Madhava might have belonged to.
The term "Ilaññippaḷḷi" has been identified as a reference to the residence of Mādhava. This is corroborated by Mādhava himself. In his short work on the moon's positions titled Veṇvāroha, Mādhava says that he was born in a house named bakuḷādhiṣṭhita . . . vihāra. This is clearly Sanskrit for Ilaññippaḷḷi. Ilaññi is the Malayalam name of the evergreen tree Mimusops elengi and the Sanskrit name for
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https://en.wikipedia.org/wiki/Jye%E1%B9%A3%E1%B9%ADhadeva
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Jyeṣṭhadeva (Malayalam: ജ്യേഷ്ഠദേവൻ) () was an astronomer-mathematician of the Kerala school of astronomy and mathematics founded by Madhava of Sangamagrama (). He is best known as the author of Yuktibhāṣā, a commentary in Malayalam of Tantrasamgraha by Nilakantha Somayaji (1444–1544). In Yuktibhāṣā, Jyeṣṭhadeva had given complete proofs and rationale of the statements in Tantrasamgraha. This was unusual for traditional Indian mathematicians of the time. The Yuktibhāṣā is now believed to contain the essential elements of the calculus like Taylor and infinity series.
Jyeṣṭhadeva also authored Drk-karana a treatise on astronomical observations.
According to K. V. Sarma, the name "Jyeṣṭhadeva" is most probably the Sanskritised form of his personal name in the local language Malayalam.
Life period of Jyeṣṭhadeva
There are a few references to Jyeṣṭhadeva scattered across several old manuscripts. From these manuscripts, one can deduce a few bare facts about the life of Jyeṣṭhadeva. He was a Nambudiri belonging to the Parangngottu family (Sanskrtised as Parakroda) born about the year 1500 CE. He was a pupil of Damodara and a younger contemporary of Nilakantha Somayaji. Achyuta Pisharati was a pupil of Jyeṣṭhadeva. In the concluding verse of his work titled Uparagakriyakrama, completed in 1592, Achyuta Pisharati has referred to Jyeṣṭhadeva as his aged benign teacher. From a few references in Drkkarana, a work believed to be of Jyeṣṭhadeva, one may conclude that Jyeṣṭhadeva lived
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https://en.wikipedia.org/wiki/Achyutha%20Pisharadi
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Achyuta Pisharodi (c. 1550 at Thrikkandiyur (aka Kundapura), Tirur, Kerala, India – 7 July 1621 in Kerala) was a Sanskrit grammarian, astrologer, astronomer and mathematician who studied under Jyeṣṭhadeva and was a member of Madhava of Sangamagrama's Kerala school of astronomy and mathematics. He is remembered mainly for his part in the composition of his student Melpathur Narayana Bhattathiri's devotional poem, Narayaneeyam.
Works
He discovered the techniques of 'the reduction of the ecliptic'. He authored Sphuta-nirnaya, Raasi-gola-sphuta-neeti (raasi meaning zodiac, gola meaning sphere and neeti roughly meaning rule), Karanottama (1593) and a four- chapter treatise Uparagakriyakrama on lunar and solar eclipses.
Praveśaka
An introduction to Sanskrit grammar.
Karaṇottama
Astronomical work dealing with the computation of the mean and true longitudes of the planets, with eclipses, and with the vyatūpātas of the sun and moon.
Uparāgakriyākrama (1593)
Treatise on lunar and solar eclipses.
Sphuṭanirṇaya
Astronomical text.
Chāyāṣṭaka
Astronomical text.
Uparāgaviṃśati
Manual on the computation of eclipses.
Rāśigolasphuṭānīti
Work concerned with the reduction of the moon’s true longitude in its own orbit to the ecliptic.
Veṇvārohavyākhyā
Malayalam commentary on the Veṇvāroha of Mādhava of Saṅgamagrāma (ca. 1340–1425) written at the request of the Azhvanchery Thambrakkal.
Horāsāroccaya
An adaptation of the Jātakapaddhati of Śrīpati.
Narayaneeyam
Pisharati is kno
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https://en.wikipedia.org/wiki/Melpathur%20Narayana%20Bhattathiri
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Melpathur Narayana Bhattathiri ( Mēlpattūr Nārāyaṇa Bhaṭṭatiri; 1560–1646/1666), third student of Achyuta Pisharati, was a member of Madhava of Sangamagrama's Kerala school of astronomy and mathematics. He was a mathematical linguist (vyakarana). His most important scholarly work, Prakriya-sarvasvam, sets forth an axiomatic system elaborating on the classical system of Panini. However, he is most famous for his masterpiece, Narayaneeyam, a devotional composition in praise of Guruvayurappan (Krishna) that is still sung at Guruvayur Temple.
Birth and education
Bhattathri was from a village named Melpathur at Kurumbathur in Athavanad Panchayat near Kadampuzha, very close to the Tirur River, as well as near to the holy town of Thirunavaya and Bharathappuzha, that was famed as the theatre of the Mamankam festival, in Malappuram district. He was born in 1560 in a pious Brahmin family, as the son of Mathrudattan Bhattathiri, a pandit himself. Bhattathiri studied from his father as a child. He learned the Rig Veda from Madhava, Tharka sastra (science of debate in Sanskrit) from Damodara and Vyakarana (Sanskrit grammar) from Achyuta Pisharati. He became a pandit by the age of 16. He married his guru Achuta Pisharati's niece and settled at Thrikkandiyur in Tirur.
He was one of the last mathematicians of the Sangamagrama school, which had been founded by Madhava in Kerala, South India and included among its members: Parameshvara, Neelakanta Somayaji, Jyeshtadeva, Achyuta Pisharati, M
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https://en.wikipedia.org/wiki/Sheldon%20Datz
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Sheldon Datz (July 21, 1927 – August 15, 2001) was an American chemist. Born in New York City as the son of Clara and Jacob Datz, he went to Stuyvesant High School and received a degree in chemistry from Columbia University and the University of Tennessee. Along with Dr. Ellison Taylor, Datz was an early contributor to the invention of the molecular beam technique, for which Dudley R. Herschbach, Yuan T. Lee and John Charles Polanyi later won the Nobel Prize in Chemistry. He shared the Fermi Award in 2000 with Sidney Drell and Herbert York.
Datz served in the U.S. Navy and moved to Oak Ridge, Tennessee upon the opening of federal nuclear facilities there after the Second World War. He married Roslyn Gordon Datz and fathered two children: William (Bill) Datz and Joan Ellen Datz Green. They divorced, and Sheldon later married Jonna Holm Datz of Denmark.
Awards
1998 Davisson-Germer Prize in Atomic or Surface Physics
2000 Enrico Fermi Award
References
External links
AIPS obituary (Subscription required)
1927 births
2001 deaths
American physical chemists
Enrico Fermi Award recipients
Stuyvesant High School alumni
Oak Ridge National Laboratory people
United States Navy sailors
Scientists from New York (state)
Fellows of the American Physical Society
20th-century American chemists
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https://en.wikipedia.org/wiki/Circle%20bundle
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In mathematics, a circle bundle is a fiber bundle where the fiber is the circle .
Oriented circle bundles are also known as principal U(1)-bundles, or equivalently, as principal SO(2)-bundles. In physics, circle bundles are the natural geometric setting for electromagnetism. A circle bundle is a special case of a sphere bundle.
As 3-manifolds
Circle bundles over surfaces are an important example of 3-manifolds. A more general class of 3-manifolds is Seifert fiber spaces, which may be viewed as a kind of "singular" circle bundle, or as a circle bundle over a two-dimensional orbifold.
Relationship to electrodynamics
The Maxwell equations correspond to an electromagnetic field represented by a 2-form F, with being cohomologous to zero, i.e. exact. In particular, there always exists a 1-form A, the electromagnetic four-potential, (equivalently, the affine connection) such that
Given a circle bundle P over M and its projection
one has the homomorphism
where is the pullback. Each homomorphism corresponds to a Dirac monopole; the integer cohomology groups correspond to the quantization of the electric charge. The Aharonov–Bohm effect can be understood as the holonomy of the connection on the associated line bundle describing the electron wave-function. In essence, the Aharonov–Bohm effect is not a quantum-mechanical effect (contrary to popular belief), as no quantization is involved or required in the construction of the fiber bundles or connections.
Examples
The Hopf fi
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https://en.wikipedia.org/wiki/Parham%20Aarabi
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Parham Aarabi (, born August 25, 1976) is a professor and entrepreneur from Toronto, Canada.
Career
Aarabi is a professor at University of Toronto and Canada Research Chair in Internet Video, Audio, and Image Search. He has a Ph.D. in Electrical Engineering from Stanford University. He is the inventor of numerous patents and author of over 80 publications most of which focus on audio, image and video processing. His recent work has focused on new image processing techniques that detect faces and facial features, as well as new video search technologies for online video-sharing websites. He is the founder and CEO of ModiFace, a leading provider of Augmented Reality technology which was acquired in 2018 by L'Oreal. Aarabi has won several teaching and lecturing awards, including an international award from the IEEE. In 2005, he was named to the MIT Technology Review TR35 as one of the top 35 innovators in the world under the age of 35. He also received the 2007 Premier's Catalyst Award for Innovation (a $200,000 Ontario Government prize for young innovators). His work has appeared in the New York Times, the Discovery Channel, and Scientific American.
Bibliography
The art of lecturing: a practical guide to successful university lectures and business presentations, Cambridge University Press (2007)
Phase-based speech processing, (with three other authors) World Scientific (2006)
References
1976 births
Living people
Canadian people of Iranian descent
Academic staff of the Univ
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https://en.wikipedia.org/wiki/Y-homeomorphism
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In mathematics, the y-homeomorphism, or crosscap slide, is a special type of auto-homeomorphism in non-orientable surfaces.
It can be constructed by sliding a Möbius band included on the surface
around an essential 1-sided closed curve until the original position; thus it is necessary that the surfaces have genus greater than one. The projective plane has no y-homeomorphism.
See also
Lickorish-Wallace theorem
References
J. S. Birman, D. R. J. Chillingworth, On the homeotopy group of a non-orientable surface, Trans. Amer. Math. Soc. 247 (1979), 87-124.
D. R. J. Chillingworth, A finite set of generators for the homeotopy group of a non-orientable surface, Proc. Camb. Phil. Soc. 65 (1969), 409–430.
M. Korkmaz, Mapping class group of non-orientable surface, Geometriae Dedicata 89 (2002), 109–133.
W. B. R. Lickorish, Homeomorphisms of non-orientable two-manifolds, Math. Proc. Camb. Phil. Soc. 59 (1963), 307–317.
Geometric topology
Homeomorphisms
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https://en.wikipedia.org/wiki/Andr%C3%A9%20Hunebelle
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André Hunebelle (1 September 1896 – 27 November 1985) was a French maître verrier (master glassmaker) and film director.
Master Glass Artist
After attending polytechnic school for mathematics, he became a decorator, a designer, and then a master glass maker in the mid-1920s (first recorded exhibition PARIS 1927 included piece "Fruit & Foliage"). His work is known for its clean lines, which are elegant and singularly strong. He exhibited his own glass in a luxurious store located at 2 Avenue Victor-Emmanuel III, at the roundabout of the Champs Èlysées in Paris. Etienne Franckhauser, who also made molds for Lalique and Sabino, made the molds for Hunebelle's glass which was fabricated by the crystal factory in Choisy-le-Roi, France. Hunebelle's store ceased all activity in 1938 prior to World War II.
Hunebelle pieces are marked in several ways. The most common is A.HUNEBELLE-FRANCE in molded capitals either within the glass design or on the base. Other pieces are marked simply A.HUNEBELLE. There was also a paper label with A and H superimposed in a stylized manner. Since paper labels are frequently lost, many pieces may appear completely unmarked. In the author's collection there are pieces marked A.HUNEBELLE both with and without the word FRANCE, and a bowl marked MADE IN FRANCE that is identical to one shown in a Hunebelle catalogue. Hunebelle also used a more elaborate maker's mark imprinted on some glass pieces which had the word FRANCE encircled by the words MADE IN FRAN
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https://en.wikipedia.org/wiki/Chemists%20Without%20Borders
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Chemists Without Borders is a non-governmental organization involved in international development work designed to solve humanitarian problems through chemistry and related activities. As a public benefit, non-profit organization, the primary goals of Chemists Without Borders include:
providing affordable medicines and vaccines to those who need them most
providing clean water through water purification technologies
supporting sustainable energy technologies
encouraging open access to scholarly chemistry research articles throughout the world
advocating a better understanding of chemistry through education
Chemists Without Borders was founded in 2004 by Bego Gerber and Steve Chambreau as a result of a letter that Gerber sent to the editor of Chemical and Engineering News in September 2004.
See also
Appropriate technology
External links
Scientific organizations established in 2004
International scientific organizations
Chemistry organizations
International organizations based in the United States
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https://en.wikipedia.org/wiki/Gerard%20J.%20Holzmann
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Gerard J. Holzmann (born 1951) is a Dutch-American computer scientist and researcher at Bell Labs and NASA, best known as the developer of the SPIN model checker.
Biography
Holzmann was born in Amsterdam, Netherlands and received an Engineer's degree in electrical engineering from the Delft University of Technology in 1976. He subsequently also received his PhD degree from Delft University in 1979 under Willem van der Poel and J.L. de Kroes with a thesis entitled Coordination problems in multiprocessing systems. After receiving a Fulbright Scholarship he was a post-graduate student at the University of Southern California for another year, where he worked with Per Brinch Hansen.
In 1980 he started at Bell Labs in Murray Hill for a year. Back in the Netherlands he was assistant professor at the Delft University of Technology for two years. In 1983 he returned to Bell Labs where he worked in the Computing Science Research Center (the former Unix research group). In 2003 he joined NASA, where he leads the NASA JPL Laboratory for Reliable Software in Pasadena, California and is a JPL fellow.
In 1981 Holzmann was awarded the Prof. Bahler Prize by the Royal Dutch Institute of Engineers, the Software System Award (for SPIN) in 2001 by the Association for Computing Machinery (ACM), the Paris Kanellakis Theory and Practice Award in 2005, and the NASA Exceptional Engineering Achievement Medal in October 2012. Holzmann was elected a member of the US National Academy of Engineering
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https://en.wikipedia.org/wiki/ChemComm
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ChemComm (or Chemical Communications), formerly known as Journal of the Chemical Society D: Chemical Communications (1969–1971), Journal of the Chemical Society, Chemical Communications (1972–1995), is a peer-reviewed scientific journal published by the Royal Society of Chemistry. It covers all aspects of chemistry. In January 2012, the journal moved to publishing 100 issues per year. The current chair of the editorial board is Douglas Stephan (University of Toronto, Canada), while the executive editor is Richard Kelly.
Abstracting and indexing
The journal is abstracted and indexed in:
Chemical Abstracts
Science Citation Index
Current Contents/Physical, Chemical & Earth Sciences
Scopus
Index Medicus/MEDLINE/PubMed
According to the Journal Citation Reports, the journal has a 2022 impact factor of 4.9.
See also
New Journal of Chemistry
Chemical Society Reviews
Chemical Science
RSC Advances
References
External links
Chemistry journals
Journals more frequent than weekly
Royal Society of Chemistry academic journals
English-language journals
Academic journals established in 1965
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https://en.wikipedia.org/wiki/Introduction%20to%20quantum%20mechanics
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Quantum mechanics is the study of matter and its interactions with energy on the scale of atomic and subatomic particles. By contrast, classical physics explains matter and energy only on a scale familiar to human experience, including the behavior of astronomical bodies such as the moon. Classical physics is still used in much of modern science and technology. However, towards the end of the 19th century, scientists discovered phenomena in both the large (macro) and the small (micro) worlds that classical physics could not explain. The desire to resolve inconsistencies between observed phenomena and classical theory led to a revolution in physics, a shift in the original scientific paradigm: the development of quantum mechanics.
Many aspects of quantum mechanics are counterintuitive and can seem paradoxical because they describe behavior quite different from that seen at larger scales. In the words of quantum physicist Richard Feynman, quantum mechanics deals with "nature as She is—absurd".
One example of this is the uncertainty principle applied to particles, which implies that the more closely one pins down one measurement on a particle (such as the position of an electron), the less accurate another complementary measurement pertaining to the same particle (such as its speed) must become. The position and speed of a particle cannot both be measured with arbitrary precision, regardless of the quality of the measuring instruments.
Another example is entanglement. In cert
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https://en.wikipedia.org/wiki/COMSOL%20Multiphysics
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COMSOL Multiphysics is a finite element analysis, solver, and simulation software package for various physics and engineering applications, especially coupled phenomena and multiphysics. The software facilitates conventional physics-based user interfaces and coupled systems of partial differential equations (PDEs). COMSOL provides an IDE and unified workflow for electrical, mechanical, fluid, acoustics, and chemical applications.
Beside the classical problems that can be addressed with application modules, the core Multiphysics package can be used to solve PDEs in weak form. An API for Java and LiveLink for MATLAB and LiveLink products for major CAD software can be used to control the software externally. An Application Builder can be used to develop independent custom domain-specific simulation apps. Users may use drag-and-drop tools (Form Editor) or programming (Method Editor). COMSOL Server is a distinct software for the management of COMSOL simulation applications in companies. Several modules are available for COMSOL, categorized according to the applications areas of Electrical, Mechanical, Fluid, Acoustic, Chemical, Multipurpose, and Interfacing.
See also
Finite element method
Multiphysics
List of computer simulation software
References
External links
Finite element software
Finite element software for Linux
Computer-aided engineering software
Physics software
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https://en.wikipedia.org/wiki/Ferricyanide
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Ferricyanide is the anion [Fe(CN)6]3−. It is also called hexacyanoferrate(III) and in rare, but systematic nomenclature, hexacyanidoferrate(III). The most common salt of this anion is potassium ferricyanide, a red crystalline material that is used as an oxidant in organic chemistry.
Properties
[Fe(CN)6]3− consists of a Fe3+ center bound in octahedral geometry to six cyanide ligands. The complex has Oh symmetry. The iron is low spin and easily reduced to the related ferrocyanide ion [Fe(CN)6]4−, which is a ferrous (Fe2+) derivative. This redox couple is reversible and entails no making or breaking of Fe–C bonds:
[Fe(CN)6]3− + e− ⇌ [Fe(CN)6]4−
This redox couple is a standard in electrochemistry.
Compared to main group cyanides like potassium cyanide, ferricyanides are much less toxic because of the strong bond between the cyanide ion (CN− ) and the Fe3+. They do react with mineral acids, however, to release highly toxic hydrogen cyanide gas.
Uses
Treatment of ferricyanide with iron(II) salts affords the brilliant, long-lasting pigment Prussian blue, the traditional color of blueprints.
See also
Potassium ferricyanide
Ferrocyanide
References
Anions
Iron complexes
Cyanometallates
Iron(III) compounds
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https://en.wikipedia.org/wiki/Greg%20Lindsay
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Gregory John Lindsay AO (b. 1949) was until 2018 the Executive Director of the Australian think tank the Centre for Independent Studies (CIS), which he founded in 1976 when a young mathematics teacher in the western suburbs of Sydney. CIS has become influential in Australia and New Zealand.
Biography
Lindsay initially studied agricultural science at the University of Sydney, but found that this was not his real interest and instead obtained secondary teaching qualifications in mathematics at Sydney Teachers' College. A short four-year stint at Richmond High School coincided with further study at Macquarie University in philosophy culminating in graduating with a BA majoring in philosophy in 1977. The CIS's first public events were also held at Macquarie in October 1976 and in April 1977.
He was made an Officer of the Order of Australia (AO) in 2003 for his contribution to education and public debate.
In 2006 he was elected President of the Mont Pelerin Society for a two-year term at its general meeting in Guatemala. He was elected to the Council of Macquarie University for a term from 1 January 2008.
References
Officers of the Order of Australia
Living people
Year of birth missing (living people)
Australian libertarians
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https://en.wikipedia.org/wiki/Bromine%20number
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In chemistry, the bromine number is the amount of bromine () in grams absorbed by 100 g of a sample. The bromine number was once used as a measure of aliphatic unsaturation in gasoline and related petroleum samples, but this assay has fallen into disuse with the introduction of spectroscopic and chromatographic analyses.
Concept
It is based on the following reaction:
Bromine is deeply colored but is not. Thus, the consumption of bromine can often be gauged visually. Alternatively and more quantitatively, the bromine consumed by a sample can be determined by iodometry.
The bromine number indicates the degree of unsaturation of a sample. The technique can be subject to a variety of problems, whereby the sample consumes more or less bromine than predicted by the equation above. For example, some alkenes dimerize in the presence of bromine. Allylic bromination is another problem.
The bromine number is similar to the iodine number, which is a similar technique used in evaluating the unsaturation of fats and fatty acids. Iodine is less reactive toward the tri- and tetra-substituted double bonds, found in petroleum-derived samples. The C=C double bonds in fats and fatty acids are exclusively disubstituted.
The bromine number is usually determined by electrochemical titration, where bromine is generated in situ with the redox process of potassium bromide and bromate in an acidic solution, using a mercury catalyst to ensure the complete bromination of all olefins.
Related test
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https://en.wikipedia.org/wiki/Bernard%20Picinbono
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Bernard Picinbono is a French scientist born in 1933 in Algiers. His scientific work focuses on statistics and its applications in optics, electronics, signal processing and automation.
Biography
He did his secondary and higher education in Algiers and then in Paris where he obtained the agrégation de sciences physiques.
He was associate professor of physical sciences at the Algiers high school from 1956 to 1960 and then, after obtaining a doctorate in science, lecturer at the Faculty of Science in Algiers from 1960 to 1965. He was then appointed professor at the Orsay Faculty of Sciences. He was President of the University of Paris XI (now Paris-Saclay University) from 1970 to 1975, President of SupOptique (Institute of Theoretical and Applied Optics) from 1980 to 1990, and Director General of Supélec from 1990 to 1995. In the early 1980s, he was director of the master (DEA) in Automation and Signal Processing at the University of Paris XI and lectures at Supélec's signals and systems laboratory.
He is Professor Emeritus at the Paris-Saclay University and at CentraleSupélec.
Bernard Picinbono was President of Cimade from 1970 to 1983 and again from 1997 to 2002.
Awards
Member of the French Academy of sciences, elected correspondant in 1983.
Member of the French Academy of technologies.
Recipient in 1970 of the Blondel Medal awarded by the Electricity, Electronics and Information and Communication Technologies Society
Fellow of the IEEE for contributions to signal
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https://en.wikipedia.org/wiki/Ralph%20Johnson%20%28computer%20scientist%29
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Ralph E. Johnson is a Research Associate Professor in the Department of Computer Science at the University of Illinois at Urbana-Champaign. He is a co-author of the influential computer science textbook Design Patterns: Elements of Reusable Object-Oriented Software, for which he won the 2010 ACM SIGSOFT Outstanding Research Award. In 2006 he was awarded the Dahl–Nygaard Prize for his contributions to the state of the art embodied in that book as well.
Johnson was an early pioneer in the Smalltalk community and is a continued supporter of the language. He has held several executive roles at the ACM Object-Oriented Programming, Systems, Languages and Applications conference OOPSLA. He initiated the popular OOPSLA Design Fest workshop.
References
External links
Ralph Johnson's blog
Ralph E. Johnson at UIUC
Interview with Ralph Johnson from OOPSLA 2009, discussing Parallel Programming Patterns
Presentation on a Pattern Language for Parallel Programming from QCon London 2010
American computer scientists
Living people
Scientists from Illinois
University of Illinois Urbana-Champaign faculty
Dahl–Nygaard Prize
Year of birth missing (living people)
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https://en.wikipedia.org/wiki/Louis%20Bertrand%20Castel
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Louis Bertrand Castel (5 November 1688 – 11 January 1757) was a French mathematician born in Montpellier, who entered the order of the Jesuits in 1703. Having studied literature, he afterwards devoted himself entirely to mathematics and natural philosophy. After moving from Toulouse to Paris in 1720, at the behest of Bernard de Fontenelle, Castel acted as the science editor of the Jesuit Journal de Trévoux.
He wrote several scientific works, that which attracted most attention at the time being his Optique des couleurs (1740), or treatise on the melody of colours. He also wrote Traité de physique sur la pesanteur universelle des corps (1724), Mathématique universelle (1728), and a critical account of the system of Sir Isaac Newton in 1743.
Philosophical approach
Castel wrote on areas as wide-ranging as physics, mathematics, morals, aesthetics, theology and history. His philosophical approach attempted to reconcile fields and viewpoints. Castel based much of his work on analogical thinking, seeking to understand the physical and moral worlds through the discovery of analogies.
Castel's first major published work was his Traité de physique de la pesanteur universelle des corps (1724). He first attempted to systematise physical phenomena, through the mechanical action of universal gravity. He then considered a mechanistic world-view's shortcomings, from a theological and metaphysical perspective. He held humanity as central to natural philosophy, in that humans are embodied s
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https://en.wikipedia.org/wiki/Universal%20Design%20for%20Learning
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Universal Design for Learning (UDL) is an educational framework based on research in the learning sciences, including cognitive neuroscience, that guides the development of flexible learning environments and learning spaces that can accommodate individual learning differences.
Universal Design for learning is a set of principles that provide teachers with a structure to develop instructions to meet the diverse needs of all learners.
The UDL framework, first defined by David H. Rose, Ed.D. of the Harvard Graduate School of Education and the Center for Applied Special Technology (CAST) in the 1990s, calls for creating a curriculum from the outset that provides:
Multiple means of representation give learners various ways of acquiring information and knowledge,
Multiple means of expression to provide learners alternatives for demonstrating what they know, and
Multiple means of engagement to tap into learners' interests, challenge them appropriately, and motivate them to learn.
Curriculum, as defined in the UDL literature, has four parts: instructional goals, methods, materials, and assessments. UDL is intended to increase access to learning by reducing physical, cognitive, intellectual, and organizational barriers to learning, as well as other obstacles. UDL principles also lend themselves to implementing inclusionary practices in the classroom.
Universal Design for Learning is referred to by name in American legislation, such as the Higher Education Opportunity Act (HEOA
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https://en.wikipedia.org/wiki/Evolutionary%20grade
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A grade is a taxon united by a level of morphological or physiological complexity. The term was coined by British biologist Julian Huxley, to contrast with clade, a strictly phylogenetic unit.
Phylogenetics
In order to fully understand evolutionary grades, one must first get a better understanding of phylogenetics: the study of the evolutionary history and relationships among or within groups of organisms. These relationships are determined by phylogenetic inference methods that focus on observed heritable traits, such as DNA sequences, protein amino acid sequences, or morphology. The result of such an analysis is a phylogenetic tree—a diagram containing a hypothesis of relationships that reflects the evolutionary history of a group of organisms.
Definition of an evolutionary grade
An evolutionary grade is a group of species united by morphological or physiological traits, that has given rise to another group that has major differences from the ancestral group's condition, and is thus not considered part of the ancestral group, while still having enough similarities that we can group them under the same clade. The ancestral group will not be phylogenetically complete (i.e. is not a clade), and so will represent a paraphyletic taxon.
The most commonly cited example is that of reptiles. In the early 19th century, the French naturalist Latreille was the first to divide tetrapods into the four familiar classes of amphibians, reptiles, birds, and mammals. In this system, reptil
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https://en.wikipedia.org/wiki/Handle%20decompositions%20of%203-manifolds
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In mathematics, a handle decomposition of a 3-manifold allows simplification of the original 3-manifold into pieces which are easier to study.
Heegaard splittings
An important method used to decompose into handlebodies is the Heegaard splitting, which gives us a decomposition in two handlebodies of equal genus.
Examples
As an example: lens spaces are orientable 3-spaces and allow decomposition into two solid tori, which are genus-one-handlebodies. The genus one non-orientable space is a space which is the union of two solid Klein bottles and corresponds to the twisted product of the 2-sphere and the 1-sphere: .
Orientability
Each orientable 3-manifold is the union of exactly two orientable handlebodies; meanwhile, each non-orientable one needs three orientable handlebodies.
Heegaard genus
The minimal genus of the glueing boundary determines what is known as the Heegaard genus. For non-orientable spaces an interesting invariant is the tri-genus.
References
J.C. Gómez Larrañaga, W. Heil, V.M. Núñez. Stiefel-Whitney surfaces and decompositions of 3-manifolds into handlebodies, Topology Appl. 60 (1994), 267-280.
J.C. Gómez Larrañaga, W. Heil, V.M. Núñez. Stiefel-Whitney surfaces and the trigenus of non-orientable 3-manifolds, Manuscripta Math. 100 (1999), 405-422.
3-manifolds
Topology
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https://en.wikipedia.org/wiki/Proof%20complexity
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In logic and theoretical computer science, and specifically proof theory and computational complexity theory, proof complexity is the field aiming to understand and analyse the computational resources that are required to prove or refute statements. Research in proof complexity is predominantly concerned with proving proof-length lower and upper bounds in various propositional proof systems. For example, among the major challenges of proof complexity is showing that the Frege system, the usual propositional calculus, does not admit polynomial-size proofs of all tautologies. Here the size of the proof is simply the number of symbols in it, and a proof is said to be of polynomial size if it is polynomial in the size of the tautology it proves.
Systematic study of proof complexity began with the work of Stephen Cook and Robert Reckhow (1979) who provided the basic definition of a propositional proof system from the perspective of computational complexity. Specifically Cook and Reckhow observed that proving proof size lower bounds on stronger and stronger propositional proof systems can be viewed as a step towards separating NP from coNP (and thus P from NP), since the existence of a propositional proof system that admits polynomial size proofs for all tautologies is equivalent to NP=coNP.
Contemporary proof complexity research draws ideas and methods from many areas in computational complexity, algorithms and mathematics. Since many important algorithms and algorithmic techniq
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https://en.wikipedia.org/wiki/Rich%20Galichon
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Richie Alan (born Richard Alan Galichon; 1968 in NY) is an independent studio drummer. He grew up in Valley Stream, New York and attended Valley Stream Central High School. He earned a Bachelor of Arts in Computer Science from Queens College, City University of New York and pursued a Master of Business Administration degree specializing in Information Systems Management at The George Washington University School of Business. He later founded a successful Information Technology Consulting Services corporation.
During his earlier years, Richie Alan took weekly lessons at the Downs School of Music for 4 years. While studying there, Richie Alan emerged as a three-time gold medalist and one-time silver medalist in the Long Island Drum Teachers Association. Years later, he expanded his studies with legendary jazz drummer Joe Morello (Dave Brubeck Quartet) and classic-rock drummer Simon Kirke (Bad Company).
Mostly known in the underground New York music scene, Richie Alan's drumming achieved a modest following, garnering praise from well-established drummers including Tommy Aldridge (Ozzy Osbourne, Whitesnake), Bill Bruford (Yes, King Crimson), and Jonathan Mover (Fuel, Everlast, Alice Cooper)
Legendary guitarist Les Paul presented Richie Alan with an autographed custom Gibson Les Paul guitar at a Beacons in Jazz award gala in 2003.
Richie Alan performed on drums and percussion with John Ford of the Strawbs and is on Ford's 2014 "No Talkin'" album. Richie Alan has also perfor
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https://en.wikipedia.org/wiki/Dynamic%20covalent%20chemistry
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Dynamic covalent chemistry (DCvC) is a synthetic strategy employed by chemists to make complex molecular and supramolecular assemblies from discrete molecular building blocks. DCvC has allowed access to complex assemblies such as covalent organic frameworks, molecular knots, polymers, and novel macrocycles. Not to be confused with dynamic combinatorial chemistry, DCvC concerns only covalent bonding interactions. As such, it only encompasses a subset of supramolecular chemistries.
The underlying idea is that rapid equilibration allows the coexistence of a variety of different species among which molecules can be selected with desired chemical, pharmaceutical and biological properties. For instance, the addition of a proper template will shift the equilibrium toward the component that forms the complex of higher stability (thermodynamic template effect). After the new equilibrium is established, the reaction conditions are modified to stop equilibration. The optimal binder for the template is then extracted from the reactional mixture by the usual laboratory procedures. The property of self-assembly and error-correcting that allow DCvC to be useful in supramolecular chemistry rely on the dynamic property.
Dynamic systems
Dynamic systems are collections of discrete molecular components that can reversibly assemble and disassemble. Systems may include multiple interacting species leading to competing reactions.
Thermodynamic control
In dynamic reaction mixtures, multiple p
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https://en.wikipedia.org/wiki/MWI
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MWI is the country code for Malawi in several country code systems.
MWI may also refer to:
Science and technology
Many-worlds interpretation, in quantum mechanics
Message-waiting indicator, in telephony
Mobile Web Initiative, in Mobile Web
Maths Week Ireland, an all-island (Republic of Ireland and Northern Ireland) mathematics outreach initiative
Other uses
Ministry of Water and Irrigation, in Water supply and sanitation in Jordan
Warsaw Modlin Airport (IATA: WMI)
Mountain Warfare Instructor, in Mountain Warfare Training Center
See also
MW-1
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https://en.wikipedia.org/wiki/MLT
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MLT may refer to:
People
MLT (hacktivist)
Computing and technology
Mean Length Turn in wound electrical components
Mechanized loop testing, in the Loop maintenance operations system
Media Lovin' Toolkit, TV software
Metropolis light transport, a computational algorithm
Modulated lapped transform in mathematics
Multi-level transmit as in MLT-3 encoding
Multi-link trunking in networking
Transportation
Malton railway station, England, station code
Millinocket Municipal Airport, IATA code
Other uses
Master of Laws in Taxation, a college degree
Medical laboratory technician, US
MALT1 or MLT, a protein
Milton Corporation, Australia, trading code
Mobile Language Team, University of Adelaide
Modern Literal Taiwanese, an orthography
Mountlake Terrace, a suburb of Seattle, Washington
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https://en.wikipedia.org/wiki/NIG
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NIG or Nig may refer to:
NIG (insurance company)
Nig (nickname), various people
Nig, Iran
Nig, a canton in Ayrarat, Armenia
Naigaon railway station (station code: NIG)
National Institute of Genetics
Ngalakgan language (ISO 639:nig)
Niger, IOC country code
Nigeria, ITU country code
Nigger (Nig or Nig-nog), a racial slur
Nik, South Khorasan, romanized as Nig
Nikunau Airport (IATA: NIG)
Normal-inverse Gaussian distribution
See also
Nigg (disambiguation)
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https://en.wikipedia.org/wiki/Unbalanced%20line
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In telecommunications and electrical engineering in general, an unbalanced line is a pair of conductors intended to carry electrical signals, which have unequal impedances along their lengths and to ground and other circuits. Examples of unbalanced lines are coaxial cable or the historic earth return system invented for the telegraph, but rarely used today. Unbalanced lines are to be contrasted with balanced lines, such as twin-lead or twisted pair which use two identical conductors to maintain impedance balance throughout the line. Balanced and unbalanced lines can be interfaced using a device called a balun.
The chief advantage of the unbalanced line format is cost efficiency. Multiple unbalanced lines can be provided in the same cable with one conductor per line plus a single common return conductor, typically the cable shielding. Likewise, multiple microstrip circuits can all use the same ground plane for the return path. This compares well with balanced cabling which requires two conductors for each line, nearly twice as many. Another benefit of unbalanced lines is that they do not require more expensive, balanced driver and receiver circuits to operate correctly.
Unbalanced lines are sometimes confused with single-ended signalling, but these are entirely separate concepts. The former is a cabling scheme while the latter is a signalling scheme. However, single-ended signalling is commonly sent over unbalanced lines. Unbalanced lines are not to be confused with sin
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https://en.wikipedia.org/wiki/Michael%20E.%20O%27Hanlon
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Michael Edward O'Hanlon (born May 16, 1961) is the director of research and senior fellow of the foreign policy program at The Brookings Institution. He began his career as a budget analyst in the defense field.
Biography
Education and early career
O'Hanlon earned an A.B. in 1982 (in physics), M.S.E. in 1987, M.A. in 1988, and a Ph.D. in 1991 all from Princeton University, and is now a visiting lecturer there. He served as a Peace Corps volunteer in Kinshasa, Congo in the 1980s. O'Hanlon is reasonably fluent in French, having taught physics in French in the Peace Corps for two years in the Democratic Republic of Congo in the 1980s.
Personal life
O'Hanlon married Cathryn Ann Garland in 1994. They have two daughters. In addition to his work in the U.S. foreign policy field, he is an activist for people with special needs.
The Iraq War
Support and caution
Along with Brookings scholar Philip Gordon, O'Hanlon wrote in The Washington Post in late 2001 that any invasion of Iraq would be difficult and demanding and require large numbers of troops. This article led to Kenneth Adelman's famous prediction of a 'cakewalk' in a subsequent rebuttal in that same newspaper, but Gordon and O'Hanlon's argument was validated by subsequent events on the ground. He argued at a major forum on Iraq at the American Enterprise Institute (AEI) in the fall of 2002 that an invasion of Iraq could lead to 150,000 U.S. troops remaining in that country for 5 years, while expressing his view that a war
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https://en.wikipedia.org/wiki/Roberto%20Peccei
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Roberto Daniele Peccei (; January 6, 1942 – June 1, 2020) was a theoretical particle physicist whose principal interests lay in the area of electroweak interactions and in the interface between particle physics and physical cosmology. He was most known for formulating the Peccei–Quinn theory (with Helen Quinn), which attempts to resolve the strong CP problem in particle physics.
Peccei was a vice chancellor for research at the University of California, Los Angeles between 2000 and 2010.
Early life and education
The son of Aurelio Peccei (founder of the Club of Rome), Roberto Peccei was born in 1942 in Torino, Italy. He completed his secondary school in Argentina, and came to the United States in 1958 to pursue his university studies in physics. He obtained a B.S. from MIT in 1962, and M.S. from New York University (NYU) in 1964 and a Ph.D. from the MIT Center for Theoretical Physics in 1969.
Career
After a brief period of postdoctoral work at the University of Washington, he joined the faculty of Stanford University in 1971, where (with Helen Quinn) he originated Peccei–Quinn theory, still the most famous proposed solution to the strong CP problem. In 1978, he returned to Europe as a staff member of the Max Planck Institute in Munich, Germany. He joined the Deutsches Elektronen-Synchrotron (DESY) Laboratory in Hamburg, Germany, as the head of the Theoretical Group in 1984. He returned to the United States in 1989, joining the faculty of the Department of Physics at UCLA. S
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https://en.wikipedia.org/wiki/Nathaniel%20Borenstein
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Nathaniel S. Borenstein (born September 23, 1957) is an American computer scientist.
He is one of the original designers of the MIME protocol for formatting multimedia Internet electronic mail and sent the first e-mail attachment.
Biography
Borenstein received a B.A. in mathematics and religious studies from Grinnell College in 1980, and a Ph.D. in computer science from Carnegie Mellon University in 1985. Previously he attended Ohio State University (1974–75), Deep Springs College, California (1975–76), and the Hebrew University of Jerusalem, Israel (1978–79). While at CMU, he co-developed the email component of the Andrew Project. The Andrew Message System was the first multi-media electronic mail system to become used outside of a laboratory. In 1989 he became a member of technical staff at Bellcore (Bell Communications Research). There he developed a series of standards so the various electronic mail systems could exchange multimedia messages in a common way. He is responsible for sending the first MIME email attachment on March 11, 1992.
Borenstein was founder of First Virtual Holdings in 1994, called "the first cyberbank" by the Smithsonian Institution, and NetPOS.com in 2000. He worked at IBM as distinguished engineer starting in 2002 at Cambridge, Massachusetts. He then became chief scientist at email management company Mimecast in June 2010.
He is author of Programming As If People Mattered: Friendly Programs, Software Engineering, and Other Noble Delusions (Prin
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https://en.wikipedia.org/wiki/Albrecht%20F%C3%B6lsing
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Albrecht Fölsing (1940 in Bad Salzungen – 8 April 2018 in Hamburg) was a trained physicist turned into a scientific journalist. Having studied physics in Berlin, Philadelphia, and Hamburg, he worked as an academic research assistant for the German electron synchrotron named DESY. In the years 1973–2001, Fölsing was head of the Nature and Science Department of the North German Radio and Television. He has written several biographies of well-known physicists and studies of the "cheating factor" in science. His most widely known book is perhaps Albert Einstein: A Biography, which also gathers many quotations by Einstein.
Bibliography
References
1940 births
2018 deaths
People from Bad Salzungen
20th-century German physicists
German male writers
University of Hamburg alumni
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https://en.wikipedia.org/wiki/Thomas%20Poulter
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Thomas Charles Poulter (March 3, 1897 – June 4, 1978) was an American scientist and antarctic explorer who worked at the Armour Institute of Technology and SRI International, where he was an associate director.
Early career
Poulter taught physics while attending high school (1914-1918), joined the U.S. Navy in 1918 and returned to school in 1921. Poulter received his B.S. from Iowa Wesleyan College (IWC) in 1923; took a position as head of the chemistry division at IWC (1925); and served as head of the math, physics and astronomy divisions with "great creativity and much success" while attending graduate school at the University of Chicago (Ph. D., 1933).
While he was a physics professor at IWS he recognized James Van Allen as a student and put him to work, at 35 cents an hour, preparing seismic and magnetic equipment for the Antarctic Expedition.
He was second in command on the Second Byrd Antarctic Mission to the South Pole with Richard E. Byrd. The Poulter Glacier was named after him by Admiral Byrd. Byrd credited him with saving his life as the expedition leader approached death from carbon monoxide poisoning.
After his first expedition he became the scientific director of the Armour Research Foundation at the Armour Institute of Technology (later Illinois Institute of Technology) where he developed the Antarctic Snow Cruiser (a.k.a. "Penguin 1"). This device was built for and taken along on his second expedition with Admiral Byrd in 1939.
Later career
In 1948 he jo
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https://en.wikipedia.org/wiki/Lepidosaphes%20ulmi
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Lepidosaphes ulmi also known as apple mussel scale or oystershell scale is a widely invasive scale insect that is a pest of trees and woody plants. The small insects attach themselves to bark and cause injury by sucking the tree's sap; this metabolic drain on the plant may kill a branch or the entire tree.
Biology
The adult female oystershell scale is up to four millimetres long, elongated, tapering to a point at the posterior end and often slightly curved, somewhat resembling a mussel shell. The upper side is a banded, brown, waxy scale and the underside is cream coloured. There are no eyes or legs and the short antennae have only a single segment. The mandibles are lengthened into a stylet adapted for sucking sap. The female lays about one hundred oval white eggs, retaining them under her body, and then dies. Her scale darkens in colour and stays in place, protecting the eggs over the winter. They can survive temperatures as low as -32 °C. They hatch in the spring at about the time the host plant's buds are bursting. The crawlers are tiny and disperse on the host, each one looking for a suitable protected site with thin bark in which to settle, remaining in that place permanently after sinking the stylet into the host plant's vascular tissues. The crawler moults twice before becoming an adult female, forming a protective scale from larval exuviae and secretions. Some crawlers may develop into males. These undergo four moults and the adult males have eyes, three pairs of le
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https://en.wikipedia.org/wiki/Eysenck%20Personality%20Questionnaire
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In psychology, the Eysenck Personality Questionnaire (EPQ) is a questionnaire to assess the personality traits of a person. It was devised by psychologists Hans Jürgen Eysenck and Sybil B. G. Eysenck.
Hans Eysenck's theory is based primarily on physiology and genetics. Although he was a behaviorist who considered learned habits of great importance, he believed that personality differences are determined by genetic inheritance. He is, therefore, primarily interested in temperament. In devising a temperament-based theory, Eysenck did not exclude the possibility that some aspects of personality are learned, but left the consideration of these to other researchers.
Dimensions
Eysenck initially conceptualized personality as two biologically based independent dimensions of temperament, E and N, measured on a continuum, but then extending this to include a third, P.
E – Extraversion/Introversion: Extraversion is characterized by being outgoing, talkative, high on positive affect (feeling good), and in need of external stimulation. According to Eysenck's arousal theory of extraversion, there is an optimal level of cortical arousal, and performance deteriorates as one becomes more or less aroused than this optimal level. Arousal can be measured by skin conductance, brain waves or sweating. At very low and very high levels of arousal, performance is low, but at a better mid-level of arousal, performance is maximized. Extraverts, according to Eysenck's theory, are chronically under-
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https://en.wikipedia.org/wiki/Generic%20name
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Generic name may refer to:
Generic name (biology), the name of a biological genus
Placeholder name, words that can refer to objects or people whose names are temporarily forgotten, irrelevant, or unknown
Business and law
Generic brand, consumer products identified by product characteristics rather than brand name
Generic term, a common name used for a range or class of similar things not protected by trademark
Generic trademark, a brand name that has become the generic name for a product or service
Generic name, a brand name designed not to be used as a trademark; see Drug nomenclature#Nonproprietary (generic) names
Several official nonproprietary or generic naming systems for pharmaceutical substances:
International Nonproprietary Name (INN)
United States Adopted Name (USAN)
Japanese Accepted Name (JAN)
British Approved Name (BAN)
See also
Generic drug, a drug marketed under its chemical name without advertising
Colloquial name, a name or term commonly used to identify something in informal language
Generic (disambiguation)
Common name (disambiguation)
Names
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https://en.wikipedia.org/wiki/Oscar%20Hertwig
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Oscar Hertwig (21 April 1849 in Friedberg – 25 October 1922 in Berlin) was a German embryologist and zoologist known for his research in developmental biology and evolution. Hertwig is credited as the first man to observe sexual reproduction by looking at the cells of sea urchins under the microscope.
Biography
Hertwig was the elder brother of zoologist-professor Richard Hertwig (1850–1937). The Hertwig brothers were the most eminent scholars of Ernst Haeckel (and Carl Gegenbaur) from the University of Jena. They were independent of Haeckel's philosophical speculations but took his ideas in a positive way to widen their concepts in zoology. Initially, between 1879 and 1883, they performed embryological studies, especially on the theory of the coelom (1881), the fluid-filled body cavity. These problems were based on the phylogenetic theorems of Haeckel, i.e. the biogenic theory (German = biogenetisches Grundgesetz), and the "gastraea theory".
Within 10 years, the two brothers moved apart to the north and south of Germany.
Oscar Hertwig later became a professor of anatomy in 1888 in Berlin; however, Richard Hertwig had moved 3 years prior, becoming a professor of zoology in Munich from 1885 to 1925, at Ludwig Maximilian University, where he served the last 40 years of his 50-year career as a professor at 4 universities.
Hertwig was a leader in the field of comparative and causal animal-developmental history. He also wrote a leading textbook. By studying sea urchins he prove
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https://en.wikipedia.org/wiki/Yves%20Cochet
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Yves Cochet (; born 15 February 1946) is a French politician, member of Europe Écologie–The Greens. He was minister in the government of Lionel Jospin. On 6 December 2011, he was elected member of the European Parliament (MEP).
He studied Mathematics and became researcher-lecturer at Institut National des Sciences Appliquées of Rennes in 1969. In June 1971, teaming with Maurice Nivat, he obtained a PhD for his research on « Sur l'algébricité des classes de certaines congruences définies sur le monoïde libre ».
References
Publications
Yves Cochet et Maurice Nivat, « Une généralisation des ensembles de Dyck », Israel Journal of Mathematics, vol. 9, nº3, septembre 1971, .
Sauver la Terre (avec Agnès Sinaï), éd. Fayard, Paris, 2003 .
Pétrole apocalypse, éd. Fayard, Paris, 2005 .
Antimanuel d'écologie, éd. Bréal, Rosny-sous-Bois, 2009 .
External links
Homepage (archived)
1946 births
Living people
Europe Ecology – The Greens politicians
Europe Ecology – The Greens MEPs
MEPs for France 1989–1994
MEPs for France 2009–2014
Government ministers of France
French Ministers of the Environment
Deputies of the 12th National Assembly of the French Fifth Republic
Deputies of the 13th National Assembly of the French Fifth Republic
Degrowth advocates
Politicians from Rennes
University of Rennes alumni
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https://en.wikipedia.org/wiki/Bert%20Schroer
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Bert Schroer (born 10 November 1933 in Gelsenkirchen, Germany) is a German mathematical physicist, now a visiting professor in Rio de Janeiro and an emeritus professor in Berlin, who is known for his work on algebraic quantum field theory, braid groups, infraparticles, and other issues related to quantum field theory.
He studied physics at the University of Hamburg from 1953 to 1958 and received his PhD there in 1963 on the topic of "Theory of Infraparticles". From 1959 to 1961 he was a research associate at the University of Illinois and 1963–74 at the Institute for Advances Studies, Princeton. He was then associate professor at the University of Pittsburgh (1964-1970) and Full Professor at the Free University of Berlin (1970-1999). He held visiting positions at USP, São Paulo, Brazil (1971/72), at CERN, Geneva, Switzerland (1976/77), and at the Pontifical Catholic University (PUC) in Rio de Janeiro, Brazil (1979/80). Furthermore, he was a visiting professor at CERN (1985/1986) and at the Math. Dept. of UC Berkeley (1992). Since 1999 he is emeritus professor at the Institute for Theoretical Physics at the Freie Universität Berlin and visiting professor at the Centro Brasileiro de Pesquisas Físicas (CBPF), Rio de Janeiro, Brazil.
External links
Free University Berlin's Bio sketch of Dr. Schroer
1933 births
Living people
20th-century German physicists
People from Gelsenkirchen
Academic staff of the Free University of Berlin
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https://en.wikipedia.org/wiki/Sylvester%20James%20Gates
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Sylvester James Gates Jr. (born December 15, 1950), known as S. James Gates Jr. or Jim Gates, is an American theoretical physicist who works on supersymmetry, supergravity, and superstring theory. He currently holds the Clark Leadership Chair in Science with the physics department at the University of Maryland College of Computer, Mathematical, and Natural Sciences. He is also affiliated with the University Maryland's School of Public Policy. He served on former President Barack Obama's Council of Advisors on Science and Technology.
Biography
Gates, the oldest of four siblings, was born in Tampa, Florida, the son of Sylvester James Gates Sr. a career U.S. Army man, and Charlie Engels Gates. His mother died at age 42 of breast cancer when he was 11. Gates, Sr. raised his children while serving full time in the U.S. Army and retired as a sergeant major after 27 years of service — one of the first African Americans to earn this position. Gates, Sr., later worked in public education and as a union organizer.
When his father remarried, his stepmother, a teacher, brought books into the home and emphasized the importance of education. The family moved many times while Gates was growing up, but, as he was entering 11th grade, settled in Orlando, Florida, where James attended Jones High School—his first experience in a segregated African-American school. Comparing his own school's quality to neighboring white schools, "I understood pretty quickly that the cards were really stacked
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Subsets and Splits
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