Measurement of the Hardness of Thin Films

A method for evaluating the hardness of coatings with nanosize thickness is suggested. The method includes the determination of the hardness of the “coating-substrate” composition by indenting the coating and subsequent computation of the hardness with the use of the additivity rule. This requires determination of the thickness of the coating, of the hardness of the substrate, and of the indentation depth.     

Electromechanical Conversions in Composite Dielectric Materials During Complex Thermomechanical Excitation

It is shown that the degree of the stress-strain state created by temperature field can be estimated by using the electromechanical conversion phenomenon. It is established that the electromagnetic response to impact excitation of composite materials is a structure-sensitive characteristic.     

Nonlinear dynamics of a plasma torch generated by a laser pulse of large width

Experimental data on the nonlinear dynamics of a plasma torch generated by a laser pulse of large width acting upon a graphite target are presented and discussed. The mushroom shape of the luminous region and the duration of emission observed in experiment are explained by the development of the Richtmyer-Meshkov instability at the carbon plasma-air interface and by the formation of nanoparticles in the plasma expanding into the buffer gas.     

Optical properties of a nonequilibrium vibrationally excited gas

Conclusion The study of the optical properties of vibrationally excited gas is part of the general problem of studying the physicochemical properties of a nonequilibrium gas. A nonequilibrium gas is a new state of a substance with extraordinary properties. Since stationary nonequilibrium is maintained by external pumping, then by changing the external conditions the properties of a nonequilibrium gas can be altered within quite broad limits. The presence of an excess reserve of internal (vibrational) energy transforms the medium into a nonlinear one. The characteristics of the medium start to depend on factors disturbing the nonequilibrium. On the other hand the disturbing factors themselves, say, the optical or gasdynamic disturbance, the charged particle fluxes, etc., will depend in turn on the nonequilibrium that they produce. Such self-consistency makes solution of the problem difficult but then it results in new phenomena such as self-focusing.Notation N_Av Avogadro number - density - n refractive index - N density of the number of molecules - their mean polarizability - Q_j set of normal coordinates - W₀ energy of a molecule without a field - gv _j statistical weight of the vibrational statev _j with normal coordinate Q_j - m_j reduced mass - _j frequency of the j-th mode - x_e anharmony constant of the molecule - probing radiation wavelength - shift of the interference fringe - d length of the interferometer arm - r₀ initial light beam radius Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 56, No. 5, pp. 824–838, May, 1989.     

Temperature jump across a plane interface for a phase transition in a pure liquid

We develop a theoretical model of the development of a temperature jump across the boundary between phases during a phase transition in pure liquids.Notation G₁ mass flux of molecules of the liquid into the liquid - G₂ mass flux of molecules of the liquid into the vapor - G_v mass flux of vapor molecules - T₁ vapor temperature near the liquid surface - T₂ temperature of the liquid - T_v vapor temperature - R universal gas constant - c_p, c_v specific heats - r heat of vaporization - q heat flux density - K ratio c_p/c_v - parameter of the phase transition - F₀ area of the interface - P₁ pressure of the liquid - P₂ phase transition pressure - P_v vapor pressure Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 54, No. 5, pp. 793–797, May, 1988.     

A motion control for a spherical robot with pendulum drive

Problems of controlling a spherical robot with pendulum drive are considered. A mathematical model of the dynamics of this robot is constructed and control laws in the form of state feedback that provide robot motion along a given trajectory are synthesized. Results of computer simulation that demonstrate efficiency of the proposed control laws are presented.     

A method for calculating the tangent on the basis of the Hough transform

A method for calculating the tangent direction for a digital curve on the basis of the Hough transform is proposed. The initial data for the Hough transform are taken from tables of angular intervals obtained from a catalog of digital curves. Such a catalog is constructed for a chosen size of the local window on the basis of a specially developed indexation of curves. When determining the intervals of tangent directions for the catalog of curves, several methods of parameterization are used: straight line, elliptic or sinusoidal arc, and superposition of harmonics. The curve selection criterion is the maximum curvature of the corresponding smooth parametric curves. This makes it possible to adapt the method to a class of initial curves. Comparison with earlier-developed methods has demonstrated a significant increase in accuracy, especially with an increase in the curvature.     

Estimating the Ratio of Composite Ingredients by the Two-Energy Transmission Method

The possibility of measuring the ratio of composite ingredients using the two-energy transmission method has been studied. This technique differs from the known methods by its independence from the specific weight of the tested object. An equation of a measuring instrument with correction for the methodological error is derived. The formulas relating the error in concentration estimates to the errors in the calibration coefficients are presented.__________Translated from Defektoskopiya, Vol. 41, No. 4, 2005, pp. 70–75.Original Russian Text Copyright © 2005 by Zabrodskii, Nedavnii, Osipov.