The Use of Twins in Isotopic Analysis

Twin (from TW_ice IN_terval) is a set of two nested intervals. The first interval presents an internal estimation of the calculations result, the second one presents an external estimation. The most of chemical elements has two or more stable isotopes. A sample is characterized by the different ratio of stable isotopes, or the isotopic signature. This paper deals with an application of two types of twins for analysis of stable isotopic compositions. The first type of twins is the Nesterov twin, which semantically uses external estimates. With this type of twins we can say about the presence (existence) of the chemical element in the mixture. With another type of twins we can estimate the minimum and maximum contents of element that are possible in the sample. The suggested twin approach covers a very wide application set: the cosmology, global climatology, biology, Earth sciences, forensics sciences, etc.