Kinetic isotope effect Kinetic isotope effect (KIE) refers to the change in the rate of a chemical reaction upon substitution of an atom in the reactants with one of its isotopes. Formally, it is defined as the ratio of rate constants for the reactions involving the light (kL) and the heavy (kH) isotopocially substituted reactants: For example, in the following nucleophilic substitution reaction of methyl bromide with cyanide, the kinetic isotope effect of the methyl carbon, in this case defined as k12/k13, was found to be 1.082 ± 0.008.
Muons take kinetic isotope effects to extremes
In advanced topics of quantum mechanics, some of these behaviors are macroscopic (see macroscopic quantum phenomena) and emerge at only extreme (i.e., very low or very high) energies or temperatures (such as in the use of superconducting magnets). For example, the angular momentum of an electron bound to an atom or molecule is quantized. In contrast, the angular momentum of an unbound electron is not quantized. In the context of quantum mechanics, the wave–particle duality of energy and matter and the uncertainty principle provide a unified view of the behavior of photons, electrons, and other atomic-scale objects. The mathematical formulations of quantum mechanics are abstract.
In particle physics, the Dirac equation is a relativistic wave equation derived by British physicist Paul Dirac in 1928. In its free form, or including electromagnetic interactions, it describes all spin-½ particles, such as electrons and quarks, and is consistent with both the principles of quantum mechanics and the theory of special relativity, and was the first theory to account fully for special relativity in the context of quantum mechanics. Although Dirac did not at first fully appreciate at the time the importance of his results, the entailed explanation of spin as a consequence of the union of quantum mechanics and relativity—and the eventual discovery of the positron—represent one of the great triumphs of theoretical physics. Dirac equation
Researchers have uncovered a fundamental link between the two defining properties of quantum physics. Stephanie Wehner of Singapore's Centre for Quantum Technologies and the National University of Singapore and Jonathan Oppenheim of the United Kingdom's University of Cambridge published their work today in the latest edition of the journal Science. The result is being heralded as a dramatic breakthrough in our basic understanding of quantum mechanics and provides new clues to researchers seeking to understand the foundations of quantum theory. The result addresses the question of why quantum behaviour is as weird as it is—but no weirder. The strange behaviour of quantum particles, such as atoms, electrons and the photons that make up light, has perplexed scientists for nearly a century. Heisenberg Uncertainty Principle sets limits on Einstein's 'spooky action at a distance,' new research finds
[1004.2507] The uncertainty principle determines the non-locality of quantum mechanics
Some Frequently Asked Questions About Virtual Particles [Physics FAQ] - [Copyright] Original by Matt McIrvin 1994. Contents: What are virtual particles? How can they be responsible for attractive forces? Do they violate energy conservation? Do they go faster than light?
fuels and thrusters
Electromagnetic Propulsion Ships, Submarines: patents & articles
Biefeld–Brown effect During 1964, Major Alexander Procofieff de Seversky published much of his related work in U.S. Patent 3,130,945, and with the aim to forestall any possible misunderstanding about these devices, termed these flying machines as ionocraft. In the following years, many promising concepts were abandoned due to technological limitations.
Patent Pending PCT/IB2010/052975 1. Presentation The Electrodynamic Space Thruster is a propulsion system designed by Moacir L. Ferreira Jr. in order to produce propulsive force in the outer space, using a sequenced pattern of phase-shifted electric oscillations, similarly to a linear AC motor, running much faster, creating sideway electrodynamic drag, consequently, producing an astonishing acceleration without infringing the classical laws of physics (action-reaction, action-at-a-distance). Electrodynamic Space Thruster
The Fischer–Tropsch process is a collection of chemical reactions that converts a mixture of carbon monoxide and hydrogen into liquid hydrocarbons. It was first developed by Franz Fischer and Hans Tropsch at the "Kaiser-Wilhelm-Institut für Kohlenforschung" in Mülheim an der Ruhr, Germany in 1925. The process, a key component of gas to liquids technology, produces a synthetic lubrication oil and synthetic fuel, typically from coal, natural gas, or biomass. The Fischer–Tropsch process has received intermittent attention as a source of low-sulfur diesel fuel and to address the supply or cost of petroleum-derived hydrocarbons.  The Fischer–Tropsch process involves a series of chemical reactions that produce a variety of hydrocarbons, ideally with to the formula (CnH(2n+2)). The more useful reactions produce alkanes as follows: Fischer–Tropsch process
Faced with global warming and potential oil shortages, the US navy is experimenting with making jet fuel from seawater. Navy chemists have processed seawater into unsaturated short-chain hydrocarbons that with further refining could be made into kerosene-based jet fuel. But they will have to find a clean energy source to power the reactions if the end product is to be carbon neutral. How to turn seawater into jet fuel - tech - 18 August 2009
Fischer Tropsch Synthesis In general, there are two approaches to the production of substitutes for crude petroleum. In one of these, the organic material is heated at high temperatures under a high pressure of hydrogen. In the other approach, the organic material is converted to a mixture of hydrogen and carbon monoxide (syngas) and this syngas is converted to hydrocarbons by conversion over suitable catalysts. The papers included in the present volume are concerned with the indirect liquefaction approach.
(PhysOrg.com) -- A fleet of 17 buses near Shanghai has been running on ultracapacitors for the past three years, and today that technology is coming to the Washington, DC, for a one-day demonstration. Chinese company Shanghai Aowei Technology Development Company, along with its US partner Sinautec Automobile Technologies, predict that this approach will provide an inexpensive and energy efficient way to power city buses in the near future. The biggest advantage of ultracapacitors is that they can fully recharge in less than a minute, unlike lithium-ion batteries which can take several hours. The downside of ultracapacitors is that they currently have a very short range, providing a distance of only a few miles, due to the fact that ultracapacitors can store only about 5% of the energy that lithium-ion batteries can hold. Ultracapacitors Make City Buses Cheaper, Greener
ravinto ja vaikutus
Mitä maito on? Maito on biologinen raaka-aine, jonka ominaisuuksia ei voida selittää pelkästään sen kemiallisen koostumuksen perusteella. Maidon fysikaalinen rakenne ja maidon sisältämien aineosien keskinäinen vuorovaikutus säätelevät maidon käyttäytymistä eri olosuhteissa. Maidon parissa työskentelevän on tärkeä tuntea käsittelemänsä raaka-aineen ominaisuudet ja prosessoinnin vaikutukset maitoon riippumatta siitä, missä tehtävissä maidon jalostusketjussa työskentelee. Maidon mikrobiologian ja kemian opiskelu muodostavat keskeisen osan meijerialan ammattilaisten opinnoista. Esimakua tulevista opinnoista saat tästä tutustumalla maidon mikrobiologiaan , kemiaan ja fysikaalisiin ominaisuuksiin.