Monte Carlo Simulation of Hydrogen Absorption in Palladium and Palladium-Silver Alloy

Russian Physics Journal - The paper presents Monte Carlo simulation of the hydrogen absorption in palladium and palladium-silver alloy of the composition PdxAg1–x (x = 0.7–0.9) at...     

Deep microrelief measurement and stereo photography in scanning electron microscopy

Fundamental differences between standard photography and micro-object imaging in a scanning electron microscope are analyzed. Basic ways of taking stereograms with a scanning electron microscope by the object rotation method and the observing technique are described. It is shown that stereo photography correctly estimates the spatial arrangement of features in objects with an intricate microrelief and makes it possible to very accurately calculate the depth of this relief (which sometimes exceeds the field of vision at large magnifications) in wide limits (from 0.5 to 100.0 μm). Using the developed surface of Li₄Ti₅O1₂ oxide and GaAs whiskers as examples, a stereographic computational method based on linear measurements of the same area on the object before and after rotation is demonstrated.     

Hubble Law: Measure and Interpretation

We have had the chance to live through a fascinating revolution in measuring the fundamental empirical cosmological Hubble law. The key progress is analysed: (1) improvement of observational means (ground-based radio and optical observations, space missions); (2) understanding of the biases that affect both distant and local determinations of the Hubble constant; (3) new theoretical and observational results. These circumstances encourage us to take a critical look at some facts and ideas related to the cosmological red-shift. This is important because we are probably on the eve of a new understanding of our Universe, heralded by the need to interpret some cosmological key observations in terms of unknown processes and substances.     

Electrophysiological Activity and Survival Rate of Rats Nervous Tissue Cells Depends on D/H Isotopic Composition of Medium

The deuterium content modification in an organism has a neuroprotective effect during the hypoxia model, affecting anxiety, memory and stress resistance. The aim of this work was to elucidate the possible mechanisms of the medium D/H composition modification on nerve cells. We studied the effect of an incubation medium with a 50 ppm deuterium content compared to a medium with 150 ppm on: (1) the activity of Wistar rats’ hippocampus CA1 field neurons, (2) the level of cultured cerebellar neuron death during glucose deprivation and temperature stress, (3) mitochondrial membrane potential (MMP) and the generation of reactive oxygen species in cultures of cerebellar neurons. The results of the analysis showed that the incubation of hippocampal sections in a medium with a 50 ppm deuterium reduced the amplitude of the pop-spike. The restoration of neuron activity was observed when sections were returned to the incubation medium with a 150 ppm deuterium content. An environment with a 50 ppm deuterium did not significantly affect the level of reactive oxygen species in neuron cultures, while MMP decreased by 16–20%. In experiments with glucose deprivation and temperature stress, the medium with 50 ppm increased the death of neurons. Thus, a short exposure of nerve cells in the medium with 50 ppm deuterium acts as an additional stressful factor, which is possibly associated with the violation of the cell energy balance. The decrease in the mitochondrial membrane potential, which is known to be associated with ATP synthesis, indicates that this effect may be associated with the cell energy imbalance. The decrease in the activity of the CA1 field hippocampal neurons may reflect reversible adaptive changes in the operation of fast-reacting ion channels.     

Justification of an integro-functional method for diffraction problems in the presence of a half-space

In the present paper, we consider the discrete sources method as applied to the analysis of a scalar problem of the diffraction of a plane wave on a particle partly immersed in an absorbing half-space. The convergence of the method is proved with the use of a system of surface integral equations. We prove the Fredholm property of the obtained system and its unique solvability.     

On the mechanism of current instability in organic semiconductors

A mechanism responsible for current instability effects at the metal — organic film — aqueous solution of organic semiconductor interface is developed and discussed. __________ Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 11, pp. 3–5, November, 2005.     

Experimental investigation of the resistance laws for gas flow in a low-porosity medium at high Reynolds numbers

The interphase interaction force at low porosity was studied experimentally. Two methods are proposed for calculating the specific surface area of pores and for obtaining approximation relations for the resistance force and the Cozeni-Carman constant which are valid in a wide range of values of the parameters of the flow and porous layer.Scientific-Research Institute of Applied Mathematics and Mechanics at Tomsk State University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 4, pp. 101–109, April, 1993.