منابع مشابه
Evolution of uranium and thorium minerals
The origins and near-surface distributions of the ~250 known uranium and/or thorium minerals elucidate principles of mineral evolution. This history can be divided into four phases. The first, from ~4.5 to 3.5 Ga, involved successive concentrations of uranium and thorium from their initial uniform trace distribution into magmatic-related fluids from which the first U4+ and Th4+ minerals, uranin...
متن کاملTuning the Clock : Uranium and Thorium
We obtain age estimates for the progenitor(s) of the extremely metal-poor ([Fe/H = −2.9) halo star CS 31082-001, based on the recently reported first observation of a Uranium abundance in this (or any other) star. Age estimates are derived by application of the classical r-process model with updated nuclear physics inputs. The [U/Th] ratio yields an age of 13±4 Gyr or 8±4 Gyr, based on the use ...
متن کاملConfigurational analysis of uranium-doped thorium dioxide
While thorium dioxide is already used industrially in high temperature applications, more insight is needed about the behaviour of the material as part of a mixed-oxide (MOX) nuclear fuel, incorporating uranium. We have developed a new interatomic potential model, commensurate with a prominent existing UO2 potential, to conduct configurational analyses of uranium-doped ThO2 supercells. Using th...
متن کاملThorium divanadate dihydrate, Th(V2O7)(H2O)2
The title compound, Th(V(2)O(7))(H(2)O)(2), was synthesized by a hydro-thermal reaction. The crystal structure consists of ThO(7)(OH(2))(2) tricapped trigonal prisms that share edges, forming [ThO(5)(OH(2))(2)](n) chains along [010]. The edge-sharing ThO(7)(OH(2))(2) polyhedra share one edge and five vertices with the V(2)O(7) divanadate anions having a nearly ecliptic conformation parallel to ...
متن کاملBioaccessibility of U, Th and Pb in solid wastes and soils from an abandoned uranium mine.
Bioaccessible U, Th, Pb and the 238U decay products 214Pb and 210Pb have been determined, using a modified Unified BARGE Method (UBM), in waste solids and soils from an abandoned uranium mine in South West England, UK. Maximum aqua regia extractable concentrations for U, Th and Pb were 16,200, 3.8 and 4750 μg g-1, respectively. 238U had highest activity concentrations near the mine shaft, where...
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ژورنال
عنوان ژورنال: Journal of Phase Equilibria and Diffusion
سال: 2012
ISSN: 1547-7037,1863-7345
DOI: 10.1007/s11669-012-9991-5