Autocompensation of an ion beam in an accelerator with an anode sheath

Experiments to study the autocompensation of an ion beam are described. It is shown that in accelerators with an anode sheath and isolated collector, autocompensation occurs as a result of the excitation of an auxiliary non-self-sustained gas discharge. Pis’ma Zh. Tekh. Fiz. 23, 69–73 (May 26, 1997)     

Study of an electrical model of an ecological system

An analysis is made of an electrical model of an ecological system. The model is a physical object which can be tested and which has a finite number of external pole points. The methods, characteristics, and possibilities of modeling informative parameters on pollution are examined. Translated from Izmeritel'naya Tekhnika, No. 5, pp. 20–25, May, 1999.     

Kinking of an interface crack in an orthotropic bimaterial

We investigated the asymptotic problem of a kinked interface crack in an orthotropic bimaterial under in‐plane loading conditions. The stress intensity factors at the tip of the kinked interface crack are described in terms of the stress intensity factors of the interface crack prior to the kink combined with a dimensionless matrix function. Using a modified Stroh formalism and an orthotropy rescaling technique, the matrix function was obtained from the solutions of the corresponding problem in transformed bimaterial. The effects of orthotropic and bimaterial parameters on the matrix function were examined. A reduction in the number of dependent material parameters on the matrix function was made using the modified Stroh formalism. Moreover, the explicit dependence of one orthotropic parameter on the matrix function was determined using an orthotropic rescaling technique. The effects of the other material parameters on the matrix function were numerically examined. The energy release rate was obtained for a kinked interface crack in an orthotropic bimaterial.     

Velocity of an electric arc in an annular gap

We investigate the influence of the current, magnetic-field induction, air flow, and interelectrode gap on the arc velocity in an annular gap between concentric electrodes. Generalized equations in critical (dimensionless) form are presented for the experimental data.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 19, No. 6, pp. 1046–1051, December, 1970.     

Design of an access control module for an instrumentation gateway

This paper describes some of the preliminary work performed on a resource access control module for an instrumentation gateway. The access control module employs a variation of the popular role-based access control (RBAC) scheme described by various authors. The gateway has very little security; hence, any user able to log onto the system is able to control any resource. This module aims to implement a pluggable module whereby users are granted access to various parts of the system depending on their user rights, while giving the administrator a very powerful method of restricting access without sacrificing ease of administration.     

使用光纤放大器的频分复用光纤传输系统

报道了一个使用光纤放大器的两路非相干频分复用光纤传输实验系统。系统采用国产ＤＦＢ激光器作光源，用意大利生产的光纤放大器作在线放大器，用自制的光学谐振腔作光学滤波器和解复用器，采用ＦＳＫ调制制式，将１４０Ｍｂ／ｓ非归零伪随机码传输了５０公里，得到了很好的眼图。在频道间距为１０ＧＨｚ情况下，未观测到邻道干扰和光纤放大器的非线性现象。     

Thermal protection of an area from an incident gas jet

Results are offered from an experimental study of the decrease in thermal effect of a jet upon a normally oriented surface produced by introduction of cold air or water into the central portion of the jet.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 62, No. 4, pp. 555–558, April, 1992.     

Modal vibrations of an infinite cylinder in an acoustic halfspace

Acoustic radiation from an infinite cylindrical surface vibrating with an arbitrary, time-harmonic surface velocity distribution while positioned near the rigid/compliant boundary of a semi-infinite ideal compressible fluid medium is determined in an exact fashion using the classical method of separation of variables. The formulation utilizes the appropriate wave-field expansions and the method of images along with the pertinent translational addition theorem to develop a closed-form solution in form of infinite series. The analytical results are illustrated with numerical examples in which the cylindrical source, vibrating in the monopole and dipole-like modes, is positioned near the rigid/compliant boundary of a water-filled acoustic halfspace. Subsequently, the basic acoustic field quantities such as the modal acoustic radiation impedance load, radiated far-field pressure and the radiation intensity distribution are evaluated for representative values of the parameters characterizing the system.     

Correctness of an analytical solution of an inverse problem of heat conduction

We discuss the analytical solution of an inverse Cauchy boundary-value problem of heat conduction and analyze its correctness.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 49, No. 6, pp. 1015–1018, December, 1985.     

Experimental realization of an imaging system with an extended depth of field

We describe the experimental realization of an all-optical imaging system with an extended depth of field (DOF). The core of the system is a phase mask consisting of 16 Fresnel lenses (FLs) that are spatially multiplexed and mutually exclusive. Because each FL, in tandem with the primary lens, is designed to produce a sharp image for a specific object plane location, jointly the FLs achieve a wide DOF. However, the resultant image exhibits reduced resolution. The acquired image, onto which we did not apply any postprocessing, clearly is sharper than that acquired with a clear-aperture imaging system with the same pupil size.     

Spreading of a drop of an electrorheological suspension in an external field

We analyze the effect of a constant electric field on the dynamics of the spreading of an electrorheological suspension drop. We discovered a strong effect of the electric field intensity on the speed of spreading and shape of the drop. An empirical relationship is established between the contact spot radius and droplet height and the magnitude of the voltage supplied to the electrodes. Academic Scientific Complex “A. V. Luikov Heat and Mass Transfer Institute of the Academy of Sciences of Belarus,” Minsk, Belarus. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 70, No. 5, pp. 766–770, September-October, 1977.     

Investigation of the instability of an arc descharge in an air flow

Using an automated complex of spectral apparatuses that allow one to determine local profiles of averaged temperature and its oscillations in a dc arc-discharge column, we investigated the temperature instability of the arc plasma in a laminar air flow. We show that the character of oscillations corresponds to the model of thermal destabilization of discharge. Academic Scientific Complex “A. V. Luikov Heat and Mass Transfer Institute of the Academy of Sciences of Belarus,” Minsk, Institute of Molecular and Atomic Physics of the Academy of Sciences of Belarus, Minsk. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 69, No. 5, pp. 800–804, September–October, 1996.     

Numerical simulation of an optically active medium of an OD-CO2 laser

A quasi-one-dimensional model of an optically active medium of a chemical OD-CO₂ laser with thermal initiation is proposed. Results of calculations are. in good agreement with the experiment. The maximal specific power of generation is 66 J/g.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 61, No. 6, pp. 885–894, December, 1991.