Structure–phase state of the surface layers in rails subjected to differential hardening

A layer-by-layer analysis of the structures, the phase compositions, and the defect substructures of differentially hardened rails has been carried by optical and transmission electron microscopy. It is found that the material volume of the rail head fillet is cooled faster than the volume located along the central axis.     

On stochastic comparisons of finite mixtures for some semiparametric families of distributions

In this paper, we consider the classical finite mixture model, which is an effective tool for modeling lifetime distributions for random samples from heterogeneous populations. We discuss new results on stochastic comparison for two finite mixtures when each of them is drawn from one of the following semiparametric families, i.e., proportional hazards, accelerated lifetime and proportional reversed hazards.     

Progressive damage modelling of SMC composite materials

The present work deals with the modelling of damage behaviour for sheet moulding compound (SMC) composite materials using a finite element analysis package. Specifically, a comparison is made between the results obtained experimentally for a three-point bending test, and those obtained from numerical simulation using a material model already implemented. The simulation has been performed for the material models available within the PAM-CRASH software. The simulation results are compared and validated with respect to experimentation.     

High-voltage bridge for measuring spontaneous polarization,dielectric constants,and conductivity of ferroelectric crystals

Translated from Izmeritel'naya Tekhnika, No. 9, pp. 34–35, September, 1989.     

Void fraction and pressure drop in two-phase liquid metal flows in channels

Experimental results on void fraction and friction pressure drop in vapour-potassium flows in the high-vapour-quality region up to unity are presentéd. The experimental data obtained and the pertinent results of other authors are generalized, and empirical relationship are suggested to calculate void fraction and pressure drop in two-phase liquid metal flows for channels of various configurations and orientations. The relationships are valid within the range of vapour qualities from almost zero to unit. The experimental data prove the mass velocity to have no influence on the hydrodynamic characteristics within the range of the parameters investigated. It is found in the experiments with heat supply that friction pressure losses are smaller than those for adiabatic conditions. It is shown that this result is in good correspondence with the model of the effect of injection in a boundary layer on the value of shear stresses between cases.     

Vesicular transport of nutrients in the small intestine during natural feeding

Ultrastructural aspects of the absorption of nutrients by the rat small bowel under natural feeding and administration of a food mixture homogenate to a small bowel strip were studied. It is shown that as early as 25 min after the onset of feeding, nutrients get into the proximal part of the small bowel, run across the epithelial barrier and enter the stroma of the intestinal villi and the vascular bed. Active absorption of nutrients is also observed in situ under limited intracavitary hydrolysis. The identified nutrients penetrate the apical membrane of enterocytes by pinocytosis, are detectable but inside vesicular structures of the cell, and get into the intercellular space by exocytosis. The concept of the existence of the control systems preventing foreign substances from penetration in the body and eliminating the sequels of such a penetration has been worded.     

Degenerate four-wave mixing spectroscopy excited by ultrashort laser pulses

A new method is described for spectroscopic diagnostics of combustion and explosion products, which makes it possible to study processes occurring at short times in hot and dense molecular gases. Pis’ma Zh. Tekh. Fiz. 23, 16–19 (March 26, 1997)