COMPARATIVE RESEARCHES OF FRACTURES OF HIGH-STRENGTH CAST IRON IN THE AS-CAST AND DEFORMED STATE by A. I. Pokrovsky, I. N. Khrol

Subjects: “…the results of comparative studies of fracture surfaces of high-strength cast iron in the as-cast state and after hot direct extrusion through an aperture of a conical die are presented. the shape change of graphite inclusions and components of the metal matrix is examined with increasing the reduction ratio from 0 (as-cast state) to 80%. for the fist time, using the electrochemical etching of the metal matrix of the cast iron, it is demonstrated experimentally that at plastic deformation the ductile flow of graphite inclusions occurs without fracturing of the latter. the surface morphology of a deformed graphite inclusion is revealed. it is shown that inside the inclusion the strain is distributed non-uniformly: the peripheral zones are deformed to a larger extent while the central part may retain its original radial structure. the fact that the most part of graphite inclusions on the fracture surface of the deformed cast iron appeared undamaged (very small amount of fractured inclusions was observed) testifies against the common opinion that graphite acts as a crack nucleation site. a hypothesis is put forward that the crack nucleates in the metal matrix, presumably at the pearlite/ferrite interface, and propagates from one graphite inclusion to another rounding but not damaging the latter.…”
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ROLE OF THE STRUCTURAL FACTOR IN THE DISTRIBUTION OF HIGH-RADON GROUNDWATER IN THE SOUTHWESTERN FLANK OF THE SOUTH BAIKAL RIFT BASIN by K. Zh. Seminsky, Yu. P. Burzunova, A. K. Seminsky, A. A. Bobrov

Subjects: “…this article discusses the distribution patterns of high-radon groundwater at the southwestern shore of lake baikal. this region is a flank of the south baikal rift basin, characterized by high geodynamic activity and complex fault patterns, without any special geochemical conditions with regard to the content of uranium in the rocks. based on our observations and measurements, we consolidated the first massive database on radon volume activity (q) in a variety of local water sources. in the kultuk–vydrino area, the q values vary from zero to 81.1 bq/l, according to the analysis of the water samples from 93 springs, lakes, small streams, wells, and drilled holes. the highest concentrations of radon are discovered in the groundwater samples. such values are unevenly scattered across the study area. the chain of the maximum q values trends northwestwards along the lake baikal shore. this distribution pattern of radon, as well as the locations of individual water sources with q>15 bq/l are predetermined by the structural factor. the paragenetic analysis of faults and joints in the kultuk–vydrino area shows that this factor includes both the structure and stages in the development of the regional largest main sayan fault zone (the southwestern flank of the south baikal basin is a segment of this zone). the water sources with increased concentrations of radon are located in zones with a high density of the 2nd order faults, especially on sites wherein the nw-striking faults cross the transverse faults that have experienced repeated activation. temperature t is an additional factor influencing the degree of radioactivity in water. a relationship between t and q is reverse. water sources with q>15 bq/l associated with the 2nd order fault zones may occur also due to a locally lower temperature of groundwater. our study gives evidence that the southwestern coast of lake baikal is promising for finding high-radon water sources. using such water in balneo¬logy can become a valuable contribution to the tourism and recreational potential of the region. this prospect is especially important for the town of baikalsk that is now developing without its township-forming enterprise: the notorious pulp-and-paper mill has been completely shut down.…”
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The content of some vasoactive humoral-metabolic factors in patients with cirrhosis and their participation in pathogenesis of comorbid syntropical damages of cardiovascular system by Abrahamovych M., Abrahamovych О., Farmaha M.

Subjects: “…the local vasoactive compounds are in such interactions with each other that result in hyperactivity of the renin-angiotensin-aldosterone system and endothelial dysfunction with a significant increase in both vasoconstrictor endothelin-1 and vasodilator NO…”
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