Estimates of the supremum of a class of stationary random processes

Under the conditions guaranteeing the uniform convergence of the spectral representations, we obtain estimates for the distribution of its supremum. We obtain estimates for the supremum of a real stationary process for which the corresponding spectral processes belong to the space Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 43, No.12, pp. 1628–1637, December, 1991.     

Manganese doping of In1−xGaxAsyP1-y films in liquid-phase epitaxy

The manganese doping of In_1–xGa_xAs_yP_1-y(0 y 1) films grown by liquid-phase epitaxy has been investigated. A study has been made of the influence of the solid-solution composition and of the method of introducing the manganese into the solution melt on the electrical properties of the films, and also on the surface morphology, the optical absorption edge, and the mismatch of the film and substrate lattice constants. It is shown that the hole density in the films decreases with decreasing y. The reasons for this are the decrease in the distribution coefficient of the acceptor manganese (from 0.3 to 0.001), the increase in the degree of compensation of the acceptors with donors (from 0.2 to 0.9), and the increase in the acceptor ionization energy. The composition of the InGaAsP:Mn film and the morphology of its surface depend on the method of preparation of the melt, this being explained by the strong interaction of the manganese atoms with the other components of the liquid phase.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 1, pp. 26–34, January, 1992.We thank T. G. Druzhinin, Ya. I. Otman, and V. B. Yabzhanov for helping with the experiments.     

Structure of the products of the reaction of 9,10-dimethylacridinium salts with aromatic o-hydroxy aldehydes

The reaction of 9,10-dimethylacridinium methosulfate with aromatic o-hydroxy aldehydes in alcohol in the presence of piperidine gives 10-methyl-4-(10-methyl-9-acridanylidenemethyl)-spiro[acridan-9,2-chromans]. The structure of the compounds obtained was established by means of the PMR, UV, and IR spectra.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 539–544, April, 1973.     

Pyrimidotetrathiafulvalenes. 3.* synthesis and properties of cation-radical salts,cation-radical betaines,and complexes of dimethyl[2,4-dioxo(1H,3H)pyrimido]tetrathiafulvalene and its N-alkyl substituted derivatives with iodine

The reaction of dimethyl[2,4-dioxo(1H,3H) pynmido]tetrathiafulvalene and its N-alkyl derivatives with iodine leads to the formation of complexes with various numbers of iodine atoms. Depending on the conditions, the betaine of the cation-radical of dimethyl[2, 4-dioxo(1 H, 3H)pyrimidojtetrathiafulvalene or a complex of the latter with dimethy1[2,4-dioxo(1H,3H)pyrimidoltetrathiafulvalene is formed by the oxidation of the pyrimidotetrathiafulvalene. The cation-radical perchlorates are formed on carrying out the oxidation of dimethyl[2,4-dioxo(1H,3H)pyrimidojtetrathiafulvalene and its N-methyl derivatives in the presence of perchloric acid. The preparation of the cation-radical salts is usually linked with the reaction of the cation-radical betaine with acids.For part 2 see [1].     

Stability of single-mode oscillations synchronized by an external signal in A multimode cyclotron-resonance maser monotron

Conclusions Premodulation of the electron beam by an external signal and appropriate choice of parameters for a synchronized CRM monotron increase the starting values of the parameters I_s proportional to the beam current and the Q's of competing modes. In maximum-efficiency regimes (for optimal beam current and externalsignal frequency), the stability of single-mode oscillations in a CRM monotron is ensured for any competing-mode Q's, regardless of the values of the parameters,, , X, or n.Scientific-Research Institute of Radio Physics. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 19, No. 3, pp. 453–459, March, 1976.     

Photostimulated kinetic effects in semiconductors

It is shown that the presence of intense laser radiation can result in the origination of spreading of kinetic effects even in a degenerate monopolar semiconductor with an isotropic energy spectrum, where the magnitude of such photostimulated effects can exceed the magnitude of corresponding effects in the absence of radiation, due to the thermal spread of current carriers in the energies or anisotropies of isoenergetic surfaces. Photostimulated Ettingshausen, Peltier, and transverse magnetoresistive effects are considered.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 2, pp. 121–129, February, 1976.     

Electromechanical effect in an antiferroelectric liquid crystal

Abstract

The electromechanical properties of a compound exhibiting an antiferroelectric phase were investigated. An electric field induced antiferroelectric-ferroelectric transition could be detected by vibration analysis. In the antiferroelectric state the vibrations almost vanish while in the ferroelectric state the electromechanical effect has the same magnitude as in the chiral smectic C* phase.     

Genotoxicity and Cytotoxicity of 4-Nonylphenol Ethoxylate on Lymphocytes as Assessed by the Comet Assay

Surfactants, which are prevalent at industrial sites and in the environment generally, are potential risk factors in human carcinogenesis. The widespread industrial use of surfactants such as 4-alkylphenol ethoxylates and their prevalence in many cleaning products have provoked studies about surfactant concentrations in water and their toxicity levels. Up to now, these substances have mainly been tested on aquatic organisms. Though tests on human cell lines are rare. The alkaline Comet assay was performed to evaluate the genotoxicity of 4-nonylphenol ethoxylate, a biodegradable product of 4-alkylphenol ethoxylate, in human lymphocytes. Concentrations tested ranged from 0.15 to 150 µg/mL. Test concentrations of 10 to 15 µg/mL caused an increase level of DNA migration in human cells, but without inducing excessive toxicity (viability > 80%). Though induced levels of DNA migration starting at concentrations of 30 µg/mL may have been due to excessive levels of cytotoxicity (viability < 70%). Based on these data, 4-nonylphenol ethoxylate can induce DNA damage in human lymphocytes but at higher concentrations than are normally found in river or drinking water. However, considering the prevalence of surfactants, the measured genotoxicity of these substances is of concern. Further investigations on human target cells are necessary to evaluate the carcinogenic impact of surfactants and reconsider their environmental acceptance.     

The impact of time on the heat resistance of self-compacting high-performance concrete incorporated with recycled martials

The influence of time on the mechanical behavior of concrete after exposure to elevated temperatures has been studied. Twenty-one self-compacting high-performance concrete mixtures with different incorporation amounts of coarse recycled concrete aggregate (RCA) and three unprocessed waste powder materials have been tested at age of 270 days for residual compressive and flexural strength after exposure to fire. The results have been compared to the results for the same concrete, which have been studied at age of 90 days. A new parameter has been introduced for comparing the responses of concrete to elevated temperatures at different ages; this parameter was the “heat resistance” which expresses the total area under the curve of the relative residual strength (compressive or flexural) after exposing to six temperature degrees (20, 150, 300, 500, 600, and 800 °C). The results showed that the age of concrete has an influence on the response of concrete to elevated temperatures. The heat resistance of compressive strength enhanced with age but the concrete behaved with a tendency different to that at the age of 90 days. The heat resistance of flexural strength has not been affected or slightly decreased but not with more than 10% to that at the age of 90 days. The used waste powder materials were unprocessed waste fly ash, waste cellular concrete powder and waste perlite powder; they proved that using any of them up to 15% as a replacement for cement with 0% or 25% of RCA enhanced the concrete resistance for the fire with time. The main two reasons for changing of residual strength with the time were the changing of water content and the proceeding of hydration of the binder. In general, long ages testing properties of concrete simulate the real behavior of concrete structures accurately.