Effects of silica and titania modification additions on the microstructure of sintered alumina

The way in which silica and titania modification additions are introduced into alumina is shown to have a strong effect on the microstructure of sintered Al₂O₃-SiO₂-TiO₂ materials. By combining molecular layering and mechanical mixing, materials with a controlled pore structure can be obtained.     

The regulation of splenocyte natural killer activity in C3HA mice in the early period after hepatoma 22a transplantation

A decrease of the natural killer activity (NKA) of C3HA splenocytes after transplantation of hepatoma 22a cells was connected to some extent with the suppressor action of macrophages and T-lymphocytes. Elimination of the macrophages from the splenocyte suspension led to the increase of NKA. Addition of the macrophages to the nonadherent cells resulted in the NKA inhibition to the level of nonfractionated splenocytes. T-cell elimination with anti-T-serum and a complement led to the increase of NKA as compared to NKA of the nonfractionated splenocytes.     

Temperature effect on polymorphic transformations in silica matrix–titania coating systems

This work examines polymorphic transformations in a silica matrix-titania coating system produced by molecular layering. The presence of surface rutile formed during the synthesis of the coating enables a reduction in the temperature of full anatase-to-rutile conversion by }~ 100°C in comparison with an anatase layer. Both the matrix and the oxide layer influence the polymorphic transformations in the SiO₂-TiO₂ system.     

On the theory of solidification with a two-phase concentration supercooling zone

The directional solidification of binary systems is theoretically studied in the presence of an extended phase-transition zone. A mathematical model is developed for this process, and its approximate analytical solution is constructed with allowance for a nonlinear liquidus line equation.     

Method of estimating the stochastic vibration stress level of the fan blading rings of aviation GTE under operating conditions based on data from development stand tests

Kuibyshev. Translated from Problemy Prochnosti, No. 4, pp. 91–95, April, 1989.     

Determination of gyrotron wave beam parameters

The output radiation of a gyrotron has the form close to the Gaussian beam. Knowing parameters of the wave beam along its way from a gyrotron to an object permits one to optimize the transmission losses. By this, the structure of the wave beam can be recorded with an infrared camera in several cross-sections of the beam. Real gyrotron wave beam is approximated with high precision by the Gaussian beam.     

A comparative study of the interaction of phosphoric acid dichlorovinyl esters with a neurotoxic esterase from the brain of hens and rats

In order to validate a rodent biochemical model of delayed neurotoxicity of organophosphates (OP) inhibition of rat and hen brain neurotoxic esterase (NTE) by some dichlorovinyl phosphates and phosphonates was studied in vitro and in vivo. It was shown that compounds investigated exhibited the similar inhibitory potency to NTE from both species in vitro, in addition rat and hen NTE showed the same sensitivity to variation of the structure of OP inhibitors. A good correlation was found between pI50 estimated with enzymes from rat and hen trains: r2 = 0.951, n = 18, p < or = 0.05. NTE activities were also measured in rat and hen brains after acute administration of various dosages of potent axonopathic compound dipropyldichlorovinyl phosphate. The results obtained indicate that difference in species susceptibility to neurotoxic action of OP, in particular the absence of ataxia in rats, is not caused by difference in target enzyme sensitivity to axonopathic organophosphates.