Kinetic isotope effect effects, while "k"/"k" ~ 1.15-1.3 are typical for β secondary kinetic isotope effect. For reactants containing several isotopically-substituted β-hydrogen atoms, the observed isotope effect is often the result of several H/D's at the β position acting in concert. In these cases, the effect of each isotopically-labeled atom is multiplicative, and cases where "k"/"k" > 2 are not uncommon. The following simple expressions relating deuterium and tritium kinetic isotope effects, which are also known as the Swain equation (or the Swain-Schaad-Stivers equations), can be derived from the general expression given above using some simplifications: i.e., In deriving these expressions, the reasonable
Atomic vapor laser isotope separation Atomic vapor laser isotope separation Atomic vapor laser isotope separation, or AVLIS, is a method by which specially tuned lasers are used to separate isotopes of uranium using selective ionization of hyperfine transitions. As compared to gas centrifuges the AVLIS process provides high energy efficiency, high separation factors, and a low volume of radioactive waste. A similar technology, using molecules instead of atoms, is molecular laser isotope separation (MLIS). The absorption lines of and U differ slightly due to hyperfine structure; for example, the U absorption peak of 502.74 nanometers shifts to 502.73 nm in U. AVLIS uses tunable dye