On the possibility of observing the aharonov-bohm effect under nonstationary potential conditions

Based on a theoretical analysis of the nonstationary excitation of a solenoid, it is demonstrated for the first time that vector potentials exist in the space outside the solenoid which can, in the general case, provide conditions for observation of the Aharonov-Bohm effect.     

On non-newtonian fluid flows under conditions of an inhomogeneous temperature distribution

Variational principles for an incompressible viscous medium determining the velocity field in steady nonisothermal motion are formulated. The flow of a polyethylene melt is investigated under conditions of an inhomogeneous temperature distribution.Translated from Inzhen-erno-Fizicheskii Zhurnal, Vol. 18, No. 5, pp. 802–809, May, 1970.     

Errors in determining the heart multipole equivalent generator parameters from the electrical potential distribution under conditions of spatial discretization of the measurements

Translated from Izmeritel'naya Tekhnika, No. 2, pp. 51–53, February, 1991.     

On the assessment of the mechanical characteristics of rail steels under operating conditions

The analysis of the mechanical state of the materials of a new rail and a rail after long-term operation are performed on the basis of the obtained data on the distributions of hardness over the cross sections of rails and the spread of the characteristics of hardness.     

On the possibility of growth quantum dot arrays in InAs/GaAs system by droplet epitaxy under MOVPE conditions

We have experimentally studied the possibility of obtaining InAs quantum dot arrays on GaAs(100) substrates by droplet-island growth under low-temperature (160–360°C) metalorganic vapor phase epitaxy (MOVPE) conditions. It is established that trimethylindium (In source) exhibits decomposition even at the lower boundary of the indicated temperature interval. The height of In drops formed on the substrate surface was 3–12 nm with a density of ∼(0.4−1.4) × 109 cm⁻² depending on the H-MOVPE conditions. In order to retain the dimensions of InAs nanocrystals formed at the subsequent stage, the process should be carried out at an increased rate of arsine supply.     

On determining the size distribution of macropores in capillary-porous materials

It is shown by experiment that the trend of the size distribution of macropores in quartz sand or in porous ceramics does not depend on the surface tension in the wetting liquid and on the specimen thickness.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 23, No. 2, pp. 294–297, August, 1972.     

Properties of a gas discharge in the field of an intense sound wave

The influence of a sound wave on the parameters of a gas discharge is investigated. The behavior of the electric field, the gas temperature in the discharge, and the electron temperature and density in the field of a sound wave is clarified. Modulation of the discharge current and electron density and temperature by a sound wave and the phase shift between oscillations of different plasma components are investigated, as well as modulation of the discharge current by a sound wave in a nitrogen discharge. The influence of sound on the contraction of a nitrogen discharge is also revealed.Institute of Applied Problems of Physics, Academy of Sciences of the Republic of Armenia, Erevan. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 62, No. 5, pp. 723–725, May, 1992.     

Problem of determining internal boundary conditions in measuring the heat of gas-turbine blades undergoing cooling

This article examines features of the numerical solution of a two-dimensional non-linear inverse problem of heat conduction in a two-layer region with a movable external boundary.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 51, No. 3, pp. 403–409, September, 1986.     

The development of an accurate time system under conditions of intense electromagnetic fields from high-voltage electrical equipment

The effect of a breakdown in the synchronization of system time in territorially remote measuring devices on the error in determining the quality and quantity of electric power is investigated. The problems involved in choosing a synchronization system and ensuring that it operates when there are intense electromagnetic fields from high-voltage electrical equipment are considered. The development of such a system using global satellite navigation systems is proposed.     

On possibility of high-power terahertz emission from target under the action of powerful laser pulses

The possibility of terahertz (THz) emission from a target irradiated by short (∼0.1 ns) high-intensity (I ∼ 10¹⁸–10¹⁹ W/cm²) laser pulses has been studied by numerical simulations using a relativistic electromagnetic PIC code. The laser pulse action on the target generates plasma and the runaway electrons form a virtual cathode, which oscillates in the intrinsic field of electrons and the field of plasma ions. These oscillations account for the emission of radiation in a THz range. The generation efficiency is about three times as high as that in the absence of ions (according to the conventional reditron mechanism). Explanation of the observed phenomena is proposed.     

Allowance for the thermal boundary layer and diffraction effects in determining the transit time of sound in ultrasonic flowmeters

The transit time of sound in ultrasonic flowmeters is investigated with allowance for the thermal boundary layer and diffraction effects.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 35, No. 3, pp. 437–444, September, 1978.     

On the possibility of the visualization of the velocity distribution in biological samples using SAM

The effect of velocity changes in a biological sample on its image, obtained by using a reflection acoustic microscope, is discussed in the case of a distance between the sample and the lens smaller than the focal length. The effect of the shift of the V(z) curve, caused by a velocity change in the material of the sample, is assumed as the main source of changes in brightness in such images. The value of the shift of V(z) curve is determined theoretically and verified experimentally for layers of glycerol and aqueous glycerol solution. The possibility of interpreting acoustic images as the images of the velocity distribution in the sample is also discussed.     

On formulas for the Rayleigh wave velocity in pre-strained elastic materials subject to an isotropic internal constraint

In the present paper, formulas for the velocity of Rayleigh waves propagating along principal directions of prestrain of an elastic half-space subject to a pure homogeneous prestrain, and an isotropic internal constraint have been derived using the theory of cubic equation. They have simple algebraic form, and hold for any strain-energy function and any isotropic constraint. In undeformed state, these formulas recover the exact value of the Rayleigh wave speed in incompressible isotropic elastic materials. Some specific cases of strain-energy function and isotropic constraint are considered, and the corresponding formulas become totally explicit in terms of the parameters characterizing the material and the prestrains. The necessary and sufficient conditions for existence of Rayleigh wave are examined in detail. The use of obtained formulas for nondestructive evaluation of prestrains and prestresses is discussed.     

Limitations on the use of an electric current when determining the thermal conductivity of graphite under steady thermal conditions

It is shown experimentally that the thermal conductivity of DE-24 graphite under steady thermal conditions when using an electric current as the heat source cannot be determined at a temperature higher than 3300 K. It is established that this temperature limit is due to spontaneous breakdown of the steady thermal operating conditions, which is expressed as an increase with time of the internal surface temperature and the mean value of the electric power assigned to the high-temperature isothermal part of the hollow cylindrical sample.     

Improvement of the methods of reproducing and transferring the dimensions of the unit of sound pressure in an aqueous medium under free-field conditions

Methods of reducing the predominant components of uncertainty in standards of sound pressure in an aqueous medium in a free field, and also methods of increasing the accuracy when the dimensions of the unit of a physical quantity are transferred by the means employed in natural measurements are reviewed. __________ Translated from Izmeritel’naya Tekhnika, No. 8, pp. 59–63, August, 2007.     

Effect of pressure on heat exchange in nitrogen boiling under conditions of free motion in an annular channel

Heat transfer and the boiling crisis are studied in nitrogen in annular channels with various gap sizes at pressures from 1.25·10⁴ to 9·10⁵ Pa.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 49, No. 3, September, 1985.     

On the full set of elastic T-stress terms of internal circular cracks under mixed-mode loading conditions

Analytical expressions for all non-singular stress terms of the asymptotic crack tip field, the so-called T-stresses of internal mixed mode circular (penny shaped) cracks in infinite homogeneous and isotropic elastic solids are addressed. To solve the problem the mixed mode crack problem is divided into sub-problems using the superposition method, and each sub-problem is then solved for the asymptotic stress field. Considering the expansion of the local stress field at the crack front, the elastic T-stress terms are derived for each sub-problem. The results are superimposed to give the analytical expressions of the so far missing elastic T-stresses of internal mixed mode penny shaped cracks.The effect of the T-stresses on the size and shape of the plastic zone at the crack tip is discussed, and analytical results are compared to the ones from finite element analyses, both for the T-stress components and the size of the plastic zone. For an accurate prediction of the plastic zone all the singular terms and the constant terms (T-stresses) in the stress expansion formulae should be considered. It is observed that negative T-stresses increase the size of the plastic zone, while positive ones reduce it.     

Effect of orientation of an annular channel on heat exchange in the boiling of nitrogen under conditions of free motion

Heat transfer and the boiling crisis of nitrogen are studied in an annular channel given different orientations; the effect of the gap size on heat-transfer characteristics is explained.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 48, No. 2, pp. 181–186, February, 1985.