Kinetic isotope effect approximation that reduced masses are approximately equal to the masses of the hydrogen, deuterium, or tritium was used. In addition, the vibrational motion was assumed to be approximated by a harmonic oscillator, so that formula_19 (X = H, D, or T). The subscript ""s"" refers to these "semi-classical" kinetic isotope effects, which disregard quantum tunneling. Tunneling contributions must be treated separately as a correction factor. For isotope effects involving elements other than hydrogen, many of these simplifications are not valid, and the magnitude of the isotope effect may depend strongly on some or all of the neglected factors. Thus, kinetic
Tritium radioluminescence vials so that the flashlight can be easily located in the dark. Tritium is used to illuminate the iron sights of some small arms. The reticle on the SA80's optical SUSAT sight as well as the LPS 4x6° TIP2 telescopic sight of a PSL rifle, contains a small amount of tritium for the same effect as an example of tritium use on a rifle sight. The electrons emitted by the radioactive decay of the tritium cause phosphor to glow, thus providing a long-lasting (several years) and non-battery-powered firearms sight that is visible in dim lighting conditions. The tritium glow is