Exposure subpopulations and peculiarities of individual dose distributions among inhabitants of the Semipalatinsk region

The results of integral dose estimations for inhabitants of four settlements near the former Semipalatinsk nuclear test site obtained by EPR dosimetry on tooth enamel in 2004-2005 years are discussed.It was found that the observed dose distributions have a nonstandard bimodal form with a mode at low doses in the range from 0.3-0.5 Gy, and a tail with higher doses, possibly suggesting two subpopulations. Possible reasons for such high doses are discussed. (c) 2007 Elsevier Ltd. All rights reserved

Phase equilibria in the Sn-As-Ge and Sn-As-P systems

T-x diagrams of polythermal GeAs-SnAs, GeAs-SnAs sections of the Sn-As-Ge system and SnP-Sn As section of the Sn-As-P system were constructed using the results of X-ray powder diffraction and differential thermal analyses. It was found that the section GeAs-SnAs is not quasi-binary due to realization of four-phase peritectic transformation L + SnAs →GeAs + SnAs at the temperature of 834 K. The quasi-binary section GeAs-SnAs represents a phase diagram of the eutectic type with the following coordinates of eutectic reaction: temperature of the eutectic point is 840 K, and composition is 20 mol% GeAs. In the Sn-As-P system, the existence of the solid-solution range indicated as (SnAs) (SnP) was defined. The polythermal section SnP-SnAs is not quasi-binary due to the fact that in the composition range with a high content of tin arsenide discussed section intersects the peritectic part of the three-phase volume (L + SnAs + α) of the ternary diagram