Mechanics of sintering materials with bimodal pore distribution. III. Kinetics of sintering combined with various forms of loading and adhesion conditions

A study has been made on the effects of loading scheme and conditions restricting macroscopic strain on the work-hardening kinetics and strain accumulation in the solid state in sintering materials with bimodal pore size distributions. Active loading intensifies the reduction in the small pores. The greatest effect comes from combining sintering with hydrostatic compression. At the same time, kinematic constraints (partial or complete adhesion in surfaces) substantially retards the shrinkage of large pores, which means that the porous structure can be controlled. __________ Translated from Poroshkovaya Metallurgiya, Nos. 5–6(449), pp. 10–15, May–June, 2006.     

Evidence for Remote Effects of Dreissenid Mussels on the Amphipod Diporeia: Analysis of Lake Ontario Benthic Surveys, 1972–2003

The status of invasive dreissenid mussels (Dreissena polymorpha and D. bugensis) and native amphipods (Diporeia spp.) in Lake Ontario was assessed in 2003 and compared with historical data. D. polymorpha (zebra mussels) were rarely observed in 2003, having been displaced by D. bugensis (quagga mussels). D. bugensis expanded its depth range from 38 m depth in 1995 to 174 m in 2003 and this dreissenid reached densities averaging 8,000/m² at all sites < 90 m. During the same time period, Diporeia populations almost completely disappeared from 0–90 m depth, continuing a declining trend from 1994–1997 reported in previous studies. The average density of Diporeia in the 30–90 m depth interval decreased from 1,380/m² to 63/m² between 1997 and 2003. Prior to 2003, areas deeper than 90 m represented a refuge for Diporeia, but even these deep populations decreased, with densities declining from 2,181/m2 in 1999 to 545/m2 in 2003. Two common hypotheses for the decline of Diporeia in the Great Lakes are food limitation and a toxin/pathogen associated with dreissenid pseudofeces. The Diporeia decline in deep waters preceded the expansion of D. bugensis to these depths, and suggests that shallow dreissenid populations remotely influence profundal habitats. This pattern of decline is consistent with mechanisms that act from some distance including nearshore dreissenid grazing and downslope transport of pseudofeces.     

Effect of nickel sulfide inclusions on the spontaneous failure of toughened glasses

Studies have shown that when smaller NiS inclusions are present the “heat-soak” method of rejecting toughened glasses does not completely guarantee that these glasses cannot fail spontaneously while in use. It is posited that the reason why glasses fail spontaneously is not so much the polymorphism of NiS as high stresses around NiS inclusions and, in consequence, a limitation on the “life” time of glass in accordance with the kinetic theory of long-term strength. __________ Translated from Steklo i Keramika, No. 5, pp. 3–6, May, 2007.     

Automated design system for an axial fan

Translated from Khimicheskoe i Neftyanoe Mashinostroenie, No. 3, pp. 8–9, March, 1992.     

Intracerebral oxytocin is important for the onset of maternal behavior in inexperienced ewes delivered under peridural anesthesia.

Measurement of cerebrospinal concentrations of oxytocin (OT) in intact and peridural-anesthetized ewes showed that central release of OT during parturition is inhibited by this anesthesia. Also, observations of maternal behavior and attraction to amniotic fluid (AF) in inexperienced peridural-anesthetized parturient ewes after intracerebroventricular injections of either OT (2?×?10 μg) or saline showed that OT infusions increased the proportion of maternal females (2/17 vs 10/20; p?=?.01) and attraction to AF. This study confirms that in sheep vaginocervical stimulation activates the oxytocinergic system, which induces the onset of maternal behavior, and that this action is not limited to maternally experienced females. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Analysis of the response of piezopolymer pressure gauges to a plane shock wave

We consider a phenomenological model for piezopolymer pressure gauges designed for registration of plane shock-wave pulses. We analyze the response of the gauges taking into account the physical phenomena observed in polarized polymer films upon action of high-intensity shock waves, the thermodynamic state of the material comprising the sensitive element, and the measurement circuit parameters. We compare the numerical calculations with experimental data for gauges made from polyvinylidene fluoride in the dynamic pressure range up to 16 GPa. We show that at such pressures, the electrical response is mainly determined by the change in the residual polarization of the piezofilm as a result of its compression.Institute of Chemical Physics at Chernogolovka. 142432 Chernogolovka. Translated from Fizika Goreniya i Vzryva, Vol. 30, No. 3, pp. 130–135, May–June 1994.     

Experience in developing ultrahigh capacity compressor stages

Translated from Khimicheskoe i Neftyanoe Mashinostroenie, No. 2, pp. 4–7, February, 1992.