KINETICS OF HYDROGEN-INDUCED REVERSE PHASE TRANSFORMATION IN Y2FE17 ALLOY ON THE BASIS OF KOLMOGOROV’S MODEL

Kinetics of the hydrogen induced reverse phase transformation in Y2Fe17 hard magnetic alloy has been analyzed in framework of Kolmogorov’s kinetic model. On the basis of Kolmogorov’s kinetic theory of the phase transformations has been obtained kinetic equation that well described the isothermal kinetic curves of reverse phase transformation in Y2Fe17 alloy in dependence on transformation temperature.Кинетика индуцированного водородом обратного фазового превращения в магнитотвердом сплаве Y2Fe17 проанализирована в рамках кинетической модели Колмогорова. На основе кинетической теории фазовых превращений Колмогорова получено кинетическое уравнение, хорошо описывающее изотермические кинетические кривые обратного фазового превращения в сплаве Y2Fe17 в зависимости от температуры превращения

Анализ смертности ликвидаторов аварии на Чернобыльской АЭС, проживающих на территории Томской области

The dearth-rate is a common reference point for the population health state. Mortality coefficient in the second decade after the accident at Chernobyl APP increased at the average by 50%.Общепринятым ориентиром состояния здоровья населения является показатель смертности. Коэффициент смертности во втором десятилетии после аварии на Чернобыльской АЭС среди ликвидаторов ее последствий в среднем увеличился на 50%

Mechanisms of seawater acclimation in a primitive, anadromous fish, the green sturgeon

Relatively little is known about salinity acclimation in the primitive groups of fishes. To test whether physiological preparative changes occur and to investigate the mechanisms of salinity acclimation, anadromous green sturgeon, Acipenser medirostris (Chondrostei) of three different ages (100, 170, and 533 dph) were acclimated for 7 weeks to three different salinities (<3, 10, and 33 ppt). Gill, kidney, pyloric caeca, and spiral intestine tissues were assayed for Na+, K+-ATPase activity; and gills were analyzed for mitochondria-rich cell (MRC) size, abundance, localization and Na+, K+-ATPase content. Kidneys were analyzed for Na+, K+-ATPase localization and the gastro-intestinal tract (GIT) was assessed for changes in ion and base content. Na+, K+-ATPase activities increased in the gills and decreased in the kidneys with increasing salinity. Gill MRCs increased in size and decreased in relative abundance with fish size/age. Gill MRC Na+, K+-ATPase content (e.g., ion-pumping capacity) was proportional to MRC size, indicating greater abilities to regulate ions with size/age. Developmental/ontogenetic changes were seen in the rapid increases in gill MRC size and lamellar length between 100 and 170 dph. Na+, K+-ATPase activities increased fourfold in the pyloric caeca in 33 ppt, presumably due to increased salt and water absorption as indicated by GIT fluids, solids, and ion concentrations. In contrast to teleosts, a greater proportion of base (HCO3− and 2CO32−) was found in intestinal precipitates than fluids. Green sturgeon osmo- and ionoregulate with similar mechanisms to more-derived teleosts, indicating the importance of these mechanisms during the evolution of fishes, although salinity acclimation may be more dependent on body size

Changes in sodium, calcium and magnesium ion concentrations in sturgeon (Huso huso) urine and in kidney morphology.

During adaptation to brackish water the young great sturgeon Huso huso is able to regulate its serum osmolarity and ion concentrations. After transfer from fresh water to brackish water the ion concentrations in the urine increase and the urine becomes isoosmotic to the blood serum after 24h. The Na+ and K+ concentrations in the urine increase during the first 12 h by 4.4 and 7.7 times, respectively, later decreasing again. The Mg2+ and Ca2+ concentrations in the urine increase by 3.4 and 14 times during the first 72h in brackish water and remain high thereafter. These results suggest that the kidneys play an important part in the regulation of serum osmolarity and in the removal of Ca2+; however, in contrast to teleosts, Mg2+ must be removed extrarenally. During adaptation to a hyperosmotic medium the diameters of the Malpighian bodies, the glomeruli and the diameter of the tubules initially all decrease, but the distal tubules become morphologically differentiated into two regions and the diameter of the distal section later increases again. It is suggested that this is the site of Ca2+ secretion into the urine