Een cilinder van klei uit 2800. Bleek een zeepachtige substantie te bevatten en ook werd een Babylonisch kleitablet van 2200. Gevonden waar een samenstelling op staat beschreven die mogelijk een zeepachtige substantie op zou leveren als er lang genoeg wordt gekookt. Ook de oude Egyptenaren gebruikten regelmatig zeep, waarbij de oliën van zowel dierlijke als plantaardige afkomst waren. Romeinse plattelandsvrouwen zouden de reinigende werking van zeep bij toeval ontdekt hebben. De klei van de oevers van de rivier de tiber bleek te helpen bij het schoonmaken van hun was, doordat het vermengd was met dierlijk vet. Dit zou afkomstig zijn van de tempel van de berg Sapo, een naam die in veel talen terugkomt in het woord voor zeep.

vetten wiki ongewenste eigenschap dat het een neerslag vormt in combinatie met calciumionen. Daardoor wordt de reinigende werking van zeep ernstig verminderd wanneer het gebruikt wordt in combinatie met hard water. Het voordeel van natriumdodecylsulfaat is dat het geen neerslag vormt in combinatie met calciumionen, waardoor schoonmaakmiddelen op basis van natriumdodecylsulfaat ook bij hard water hun reinigende werking behouden. Het eerste bewijs voor het gebruik van zeep is bijna vijfduizend jaar oud en stamt uit Babylon.

Inhoud, zeep kan vast of vloeibaar zijn en is een oppervlakte-actieve stof ; een stof die de oppervlaktespanning van een vloeistof kan verlagen. Door deze eigenschap dringen water en zeep makkelijker in het textiel. Chemisch gezien is zeep het zout van de vetzuren waaruit het ontstaat. Bij vele plantaardige vetzuren is de lengte van de koolstofketens vrij groot (14-26 koolstofatomen). De vetzuurrest is dus een lang molecuul met een polaire ionogene kop en een apolaire staart. Een dergelijk amfifiel molecuul heeft een bijzondere eigenschap: het kan zorgen dat water en olie een homogeen mengsel vormen. In een mengsel van water en olie zorgt zeep dat kleine druppeltjes olie blijven zweven in het water, doordat de apolaire staart van het molecuul in het vetdruppeltje binnendringt en de polaire kop in contact blijft met het water. Zo'n oliedruppeltje dat omgeven door zeep zweeft in water wordt een micel genoemd. Zo wordt dit vuil makkelijk verwijderd van textiel of huid. Zeep breekt echter ook de natuurlijke, vettige beschermlaag van de huid.

vetten wiki

Rachel Jewkes - wikipedia


Handgemaakte Franse zeep, schematische weergave van een micel van olie in water. Zeep ontstaat door de verzeping van een vet met loog. Ook is het mogelijk om zeep van een vetzuur met loog te maken. Het product wordt glutenvrije in combinatie met water gebruikt als schoonmaakmiddel. Toiletzeep beste van een normale, alledaagse kwaliteit wordt meestal gemaakt van rundvet, olijfolie, palmolie, palmpitolie of kokosolie. Voor de exclusievere soorten zeep wordt soms gebruikgemaakt van exotische oliën en vetten. Behalve zeep bevatten zeeptabletten in de meeste gevallen ook hulpstoffen zoals plantaardige of synthetische geurstoffen en kleurstoffen.

Blog — eva witsel


In 2012 he became a fellow of the American Mathematical Society. 26 In an informal poll at a 1990 cosmology conference, witten received the largest number of mentions as "the smartest living physicist". 27 Personal life edit witten has been married to Chiara nappi, a professor of physics at Princeton University, since 1979. 28 They have two daughters, Ilana, a neuroscientist at Princeton University, 29 and Daniela, a biostatistician at University of Washington, 30 and one son, rafael, and a granddaughter nava. Witten sits on the board of directors of Americans for peace now and is also on the advisory council of j street. 31 he supports the two-state solution and advocates a boycott of Israeli institutions and economic activity beyond its 1967 borders, though not of Israel itself. 32 Witten is also a keen tennis player.

vetten wiki

20 In another well known paper, they studied aspects of supersymmetric gauge theory. 21 The latter paper, combined with Witten's earlier work on topological quantum field theory, 9 led to developments in the topology of smooth 4-manifolds, in particular the notion of seibergWitten invariants. With Anton Kapustin, he has made deep mathematical connections between S-duality of gauge theories and engels the geometric Langlands correspondence. Partly in collaboration with seiberg, one of his recent interests include aspects of field theoretical description of topological phases in condensed matter and non-supersymmetric dualities in field theories that, among other things, are of high relevance in condensed matter theory. From a generalization of syk models from condensed matter and quantum chaos, he has also recently brought tensor models of Garau to the relevance of holographic and quantum gravity theories.

In general, witten has done influential and insightful works in many aspects of quantum field theories and mathematical physics, including the physics and mathematics of anomalies, integrability, dualities, localization, homologies and. Many of his results have deeply influenced many areas in theoretical physics (often well beyond the original context of his results including string theory, quantum gravity and topological condensed matter. Awards and honors edit witten has been dieet honored with numerous awards including a macArthur Grant (1982 the fields Medal (1990 the nemmers Prize in Mathematics (2000 the national Medal of Science 22 (2002 pythagoras Award 23 (2005 the henri poincaré Prize (2006 the Crafoord Prize. Since 1999, he has been a foreign Member of the royal Society (London and in March 2016 was elected an Honorary fellow of the royal Society of Edinburgh. 24 25 Pope benedict xvi appointed Witten as a member of the pontifical Academy of Sciences (2006). He also appeared in the list of time magazine's 100 most influential people of 2004.

Suzanne gerber - giving Taste a bad Name since


Witten's work gave a physical proof of a classical result, the morse inequalities, by interpreting the theory in terms of supersymmetric quantum mechanics. M-theory edit by the mid 1990s, physicists working on string theory had developed five different consistent versions of the theory. These versions are known as type i, type iia, type iib, and the two flavors of heterotic string theory ( SO(32) and E8E8 ). The thinking was that out of these five candidate theories, only one was the actual correct theory of everything, and that theory was the one whose low-energy limit matched the physics observed in our world today. Speaking at the string theory conference at University of southern California in 1995, witten made the surprising suggestion that these five string theories were in fact not distinct theories, but different limits of a single theory which he called M-theory.

16 17 Witten's proposal was based on the observation that the five string theories can be mapped to one another by certain rules called dualities and are identified by these dualities. Witten's announcement led to a flurry of work now known as the second superstring revolution. Other work edit Another of his contributions to physics was to the result of gauge/gravity duality. In 1997, juan Maldacena formulated a result known as the AdS/cft correspondence, which establishes a relationship between certain quantum field theories and theories of quantum gravity. 18 Maldacena's discovery has dominated high energy theoretical physics for the past 15 years because of its applications to theoretical problems in quantum gravity and quantum field theory. Witten's foundational work following Maldacena's result has shed light on this relationship. 19 In collaboration with Nathan seiberg, witten established several powerful results in quantum field theories. In their paper on string theory and noncommutative geometry, seiberg and Witten studied certain noncommutative quantum field theories that arise as limits of string theory.

Je ldl cholesterol verlagen - wikihow

As an example of Witten's work in pure mathematics, Atiyah cites his application of techniques from quantum field theory onderbuik to the mathematical subject of low-dimensional topology. In the late 1980s, witten coined the term topological quantum field theory for a certain type of physical theory in which the expectation values of observable quantities encode information about the topology of spacetime. 9 In particular, witten realized that a physical theory now called ChernSimons theory could provide a framework for understanding the mathematical theory of knots and 3-manifolds. 10 Although Witten's work was based on the mathematically ill-defined notion of a feynman path integral and was therefore not mathematically rigorous, mathematicians were able to systematically develop Witten's ideas, leading to the theory of Reshetikhin turaev invariants. 11 Another result for which Witten was awarded the fields Medal was his proof in 1981 of the positive energy theorem sterk in general relativity. 12 This theorem asserts that (under appropriate assumptions) the total energy of a gravitating system is always positive and can be zero only if the geometry of spacetime is that of flat Minkowski space. It establishes Minkowski space as a stable ground state of the gravitational field. While the original proof of this result due to richard Schoen and Shing-Tung yau used variational methods, 13 14 Witten's proof used ideas from supergravity theory to simplify the argument. A third area mentioned in Atiyah's address is Witten's work relating supersymmetry and Morse theory, 15 a branch of mathematics that studies the topology of manifolds using the concept of a differentiable function.

vetten wiki

10x glutenvrije bakrecepten - laura's bakery

2 he returned to academia, enrolling in applied mathematics at Princeton University in 1973, then shifting departments and receiving. In physics in 1976 under david Gross, obel laureate in Physics. He held a fellowship at Harvard University (197677 visited Oxford University (197778 3 8 was a junior fellow in the harvard Society of Fellows (197780 and held a macArthur foundation fellowship (1982). Research edit fields medal work edit witten was awarded the fields Medal by the International Mathematical Union in 1990, becoming the first physicist to win the prize. In a written address to the icm, michael Atiyah said of Witten, 4 Although he is definitely a physicist (as his list of publications clearly shows) his command of mathematics is rivaled by few mathematicians, and his ability to interpret physical ideas in mathematical form. Time and again he has surprised the mathematical community by a brilliant application of physical insight leading to new and deep mathematical theorems. He has made a profound impact on contemporary mathematics. In his hands physics is once again providing a rich source of inspiration and insight in mathematics. Edward afvallen Witten (left) with mathematician Shigefumi mori, probably at the icm in 1990 where they received the fields Medal.

Fields Medal by the, international Mathematical Union, awarded for his 1981 proof of the positive energy theorem in general relativity. 5, contents, early life and education edit, witten was born in, baltimore, maryland,. 6, he is the son of Lorraine (Wollach) Witten horloge and. Louis Witten, a theoretical physicist specializing in gravitation and general relativity. 7, witten attended the, park School of Baltimore (class of '68 and received his Bachelor of Arts with a major in history and minor in linguistics from Brandeis University in 1971. He published articles in The new Republic and The nation. He worked briefly for george Mcgovern's presidential campaign. Witten attended the University of WisconsinMadison for one semester as an economics graduate student before dropping out.

51 afvallen tips in een beknopt overzicht!

Nrw, witten - hohenstein laufwasserkraftwerk. — doi :.3367/UFNr.0136.198203c.0435. michael Atiyah: On the work of Edward Witten, proceedings of the International Congress of Mathematicians, kyoto, 1990 I (tokyo, 1991. Edward Witten ( /wɪtən/ ; born August 26, 1951) is an American theoretical physicist and professor of mathematical physics at the, institute for Advanced Study in, princeton, new Jersey. Witten is a researcher in string theory, quantum gravity, supersymmetric quantum field theories, and other areas of mathematical physics. In addition to his contributions to physics, witten's work has significantly impacted pure mathematics. 4, in 1990, he became the first and so far the only physicist to be awarded.

Vetten wiki
Rated 4/5 based on 453 reviews