Simulation of a Terahertz Laser in the Bloch Oscillation Mode

Technical Physics Letters - Possible designs of a terahertz laser that use the effect of Bloch oscillations in SiC natural superlattices have been considered. It has been proposed to use as a...     

The activation of oil-insoluble antifriction additives

Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 3, pp. 17–19, March 1991.     

On electromagnetic phenomena arising during the cavitational motion of a liquid in a coaxial dielectric channel

This paper presents the results of the experimental and theoretical studies of the flows of a weakly conducting liquid in a narrow coaxial channel with dielectric walls, in which the liquid is glowing. It is experimentally shown that in addition to visible light radiation, there is also electromagnetic radiation in the radio range and X-ray radiation. Various physical mechanisms that can cause these phenomena are discussed. It is assumed that the main cause of the observed phenomena is associated with the electrization of the liquid during its flow in a channel of a complex shape. The results of the calculations of electrization in the electro-hydrodynamic two-ion model of the medium are given, taking into account the electrochemical processes at the interfaces and convective charge transfer with the formation of strong electric induced fields near the walls.     

An experimental study of the effect of humidity on the distribution of charged particles in a glow-discharge plasma

The charged-particle distribution in a glow-discharge plasma in air with differing moisture concentration was studied using a double electric probe. An important difference is found in the distribution of charged particles in the discharge, depending on the humidity of the air. The amount of water vapor with a relative concentration of 2% does not affect the distribution of charged particles in the plasma, and, with an increase in moisture content up to 15%, a twofold increase in the ion concentration along the discharge axis is observed.     

Effect of Anti-Filtration Measures on Water Tables

Problems involving dewatering during construction of projects in dense urban settings, and also various aspects of the formation of the water table as a function of type of trench enclosure are discussed.     

Structural, optical and electrical properties of reactively sputtered Ag2Cu2O3 films

Ag₂Cu₂O₃ thin films were deposited on glass substrates by RF magnetron sputtering of an equiatomic silver-copper target (Ag_0.5Cu_0.5) in reactive Ar-O₂ mixtures. The reactive sputtering was done at varying power, oxygen flow rate and deposition temperature to study the influence of these parameters on the deposition of Ag₂Cu₂O₃ films. The film structure was determined by X-ray diffraction, while the optical properties were examined by spectrophotometry (UV-vis-NIR) and photoluminescence. Furthermore, the film thickness and resistivity were measured by tactile profilometry and 4-point probe, respectively. Additional mobility, resistivity and charge carrier density Hall effect measurements were done on a few selected samples. The best films in terms of stoichiometry and crystallography were achieved with a sputtering power of 100 W, oxygen and argon flow rates of 20 sccm (giving a deposition pressure of 1.21 Pa) and a deposition temperature of 250 °C. The optical transmittance and photoluminescence spectra of films deposited with these parameters indicate several band gaps, most prominently, a direct one of around 2.2 eV. Electrical characterization reveals charge carrier concentrations and mobilities in the range of 10²¹-10²² cm^− 3 and 0.01-0.1 cm²/Vs, respectively.     

Chromosomal damage in peripheral blood lymphocytes of rats in nitrosomethylurea-induced carcinogenesis

Chromosomal damages and their dynamics in blood lymphocytes of mongrel white L10 rats treated (once) intravenously with nitrosomethyl urea (NMU) at a dose of 50 mg/kg have been analyzed. A direct correlation is revealed between carcinogenesis, chromosome aberration level in somatic cells, polyploid and hyperaneuploid cell frequency 24 hs after the NMU treatment and in the precancerous period. An increase of hyperaneuploid and polyploid cells in the organism can serve as a prognostic factor of carcinogenesis.     

Mid-infrared ring laser

The first mid-infrared ring laser diode based on InAs and operating in the mid-infrared spectral region near 3 /spl mu/m and with a maximum operating temperature of 125 K is reported. The source is based on a symmetrical double heterostructure with large band offsets.