نتایج جستجو برای: environmental isotopes
تعداد نتایج: 393385 فیلتر نتایج به سال:
The ground-state properties of Zr and Sn isotopes are studied within the relativistic mean field theory. Zr and Sn isotopes have received tremendous attentions due to various reasons, including the predicted giant halos in neutron-rich Zr isotopes, the unique feature of being robust spherical in the region of 100 Sn ∼ 132 Sn and the particular interest of Sn isotopes to nuclear astrophysics. Fu...
Half lives alpha decay is the one of the most important parameters used for describing nuclear structure in nuclear dynamics; over the years, many studies have been done in this area. In this study, by using semi-empirical methods such as Viola-Seaborg (VSS), Royer, Parkhomenko and Sobiczewski (PSM), Brown, New Geiger-Nuttall (NGN), Poenaru et al. (UNIV) and Universal Decay Law (UDL), the half ...
The shape of the gamma-ray line from radioactive 26Al, at 1808.7 keV energy in the frame of the decaying isotope, is determined by its kinematics when it decays, typically 106 y after its ejection into the interstellar medium from its nucleosynthesis source. Three measurements of the line width exist: HEAO-C’s 1982 value of (0 + 3) keV FWHM, the GRIS 1996 value of (5.4± 1.3) keV FWHM, and the r...
It is very important to investigate antimony geochemical behavior in order to identify its source, or reveal contamination processes, since antimony and its compounds are considered to be pollutants of high priority by the Environmental Protection Agency of the United States (USEPA). However, the concentration of antimony in most geological samples is very low, and its stable isotope mass diffe...
For more than half a century isotopes have been employed as a powerful tool in studying various aspects of water resources in a largenumber of countries. However, in developing countries like Iran the application of such techniques is in its infancy. The first research inIran was carried out in 1975 to identify the source of saline groundwaters in south Iran, and the first national conference o...
99mTc-Macroaggregated Albumin (99mTc-MAA) has been used as a perfusion agent. This study described development of the 68Ga-MAA via commercially available kits from Pars-Isotopes Company as a 99mTc-MAA kit. 68Ge/68Ga generator was eluted with suprapure HCl (0.6 M, 6 mL) in 0.5 mL fractions. The two fractions with the highest 68GaCl3 activity were generally used for labeling purposes. After label...
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...
Detailed correlations of ancient glacial deposits, based on temporal records of carbon and strontium isotopes in seawater, indicate four (and perhaps five) discrete ice ages in the terminal Proterozoic Eon. The close and repeated stratigraphic relationship between C-isotopic excursions and glaciogenic rocks suggests that unusually high rates of organic carbon burial facilitated glaciation by re...
Stable Strontium. Elemental strontium (atomic number 38) occurs naturally in the earth's mantle as a mixture of four stable isotopes, Sr, Sr, Sr, and Sr, and is present everywhere in very dilute concentrations. It is very similar to calcium in its environmental and physiological behavior. Strontium is generally found in molecular compounds with other elements. Commercially important strontium m...
Numerous publications and reports have expressed health and safety concerns about the production and use of nanoparticles, especially in areas of exposure monitoring, personal use, and environmental fate and transport. We suggest that stable isotopic tracers, which have been used widely in the earth sciences and in metabolic and other health-related studies for several decades, could be used to...
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