نتایج جستجو برای: isotopes

تعداد نتایج: 24561  

2015
D. Porcelli M. Baskaran

Isotopes of many elements have been used in terrestrial, atmospheric, and aqueous environmental studies, providing powerful tracers and rate monitors. Short-lived nuclides that can be used to measure time are continuously produced from nuclear reactions involving cosmic rays, both within the atmosphere and exposed surfaces, and from decay of long-lived isotopes. Nuclear activities have produced...

2008
Thaísa Abreu de Souza José Marcus de O. Godoy Isabel Maria N. S. Moreira Zenildo L. de Carvalho Carlos E. de Rezende

Four isotopes of radium with different half-lives exist in nature. In aquatic systems, radium isotopes present distinct characteristics in salt water and fresh water environments. In fresh waters, radium appears adsorbed to particulate material while in sea water radium presents a conservative behavior, being the concentration of different isotopes of radium governed by the processes of dilutio...

2003
V. I. VYSOTSKII V. N. SHEVEL A. B. TASHIREV A. A. KORNILOVA

The problem of utilization of high-activity waste by effect of nuclear transmutation in growing associations of microbiological cultures was studied. For the first time we have observed utilization of several kinds of highly active isotopes in the volume of distilled water extracted from the first contour of water-water atomic reactor convert to non-radioactive nuclei. 1. The model and the foun...

2008

Terms such as isotopes and nuclear techniques often call to mind basic research of little or only minor practical importance for animal productivity and health. This is, however, not true. No other scientific tools have in our lifetime been of a significance equalling that of the isotopes in widening our insight into animal physiology and nutritional requirements. Last but not least, they have ...

2002
Frank Riget Rune Dietz Per Møller Marianne Glasius Per Palsbøll Keith Hobson Poul Johansen

The hypothesis that different populations of narwhals in the West Greenland area exist has been tested by different biomarkers (metal and organochlorine concentrations, stable isotopes and DNA). Samples of muscle, liver, kidney, blubber and skin tissues of narwhals from West Greenland have been analysed for heavy metals, organochlorines, stable isotopes and DNA. The obtained results of metal co...

2011
U. Dammalapati L. Willmann S. Knoop

We have calculated the s-wave scattering length of all the even isotopes of calcium (Ca) and barium (Ba) in order to investigate the prospect of Bose-Einstein condensation (BEC). For Ca we have used an accurate molecular potential based on detailed spectroscopic data. Our calculations show that Ca does not provide other isotopes alternative to the recently Bose condensed 40Ca that suffers stron...

Journal: :Journal of Industrial & Engineering Chemistry 1922

2007
A. Sapar

Atutov and Shalagin (1988) proposed light-induced drift (LID) as a physically well understandable mechanism to explain the formation of isotopic anomalies observed in CP stars. We generalized the theory of LID and applied it to diffusion of heavy elements and their isotopes in quiescent atmospheres of CP stars. Diffusional segregation of isotopes of chemical elements is described by the equatio...

Journal: :Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine 2005
Mark J Rivard Leo M Bobek Ralph A Butler Marc A Garland David J Hill Jeanne K Krieger James B Muckerheide Brad D Patton Edward B Silberstein

Since their introduction in the 1940s, peaceful use of stable isotopes and radioisotopes in the United States has expanded continuously. Today, new isotopes for diagnostic and therapeutic uses are not being developed, critical isotopes for national security are in short supply, and demand for isotopes critical to homeland security exceeds supply. While commercial suppliers, both domestic and fo...

The atomic nucleus is a complex many-body system that consists of two types of fermion (neutron and proton). They are in the strong interaction. The statistical properties of energy levels and influence of strong force between these fermions are well described by random matrix theory. Resonance of energy levels depends on the Hamiltonian symmetry placed in one of the GOE, GUE and GSE ensembles ...

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