Calculated and Experimental Estimation of Absorbed Mechanical Work in Deformation of Synthetic Fibres

Methods are proposed for obtaining the elastic and absorbed components of deformation and mechanical work expended in the region of a nondestructive mechanical effect from the stress-strain diagrams or by calculated prediction. The closeness of the values of the absorbed and correspondingly the elastic components obtained with the measured or predicted stress-strain diagram totally confirm the satisfactory reliability of modeling the physicomechanical properties of a fibre in the form of an integral equation in which the nonlinear-hereditary kernel analytically reflects the activating character of the mechanical effect combined with the concept of the deformation-time analogy in normalized form [5].     

Composite material in the aluminum oxide-zirconium dioxide system

A dispersion-hardened material with average flexural strength 580 ± 40 MPa, which is a promising building material, has been fabricated by introducing a CaO-ZnO-Al₂O₃-SiO₂ eutectic additive and tetragonal zirconium dioxide into aluminum oxide synthesized by calcining the hydroxide. The sintering temperature of this ceramic is 1550°C. The properties of the eutectic of this system are analyzed, and the optimal liquid-phase composition which gives intense sintering of the aluminum oxide is determined. __________ Translated from Steklo i Keramika, No. 4, pp. 12–15, April, 2007.     

Operation of an experimental facility for fabrication of fuel elements and fuel assemblies of the bor-60 containing vibrocompacted fuel

Translated from Atomnaya Énergiya, Vol. 67, No. 5, pp. 320–323, November, 1989.     

Magnetic-Field-Controlled 1D Photonic Crystal Based on a Periodic Bigyrotropic Structure

A theoretical study is reported of the magnetic-field-controlled optical transmission through a stack of identical bilayers in which one layer is bigyrotropic and the other is nonmagnetic and isotropic. An analytical expression for the complex transmittance is derived. The transmittance–wavelength characteristic is examined for different magnetizations and for fixed materials parameters and total number of bilayers. The magnetization dependence of the position, height, and width of the center peak is investigated. The effect is calculated of magnetization on the ellipticity of transmitted light and the angle of optical rotation.     

Use of a mathematical model in predicting the density of glass for controlling a tank furnace

Translated from Steklo i Keramika, No. 1, pp. 11–12, January, 1992.     

Control over the parameters of InAs-GaAs quantum dot arrays in the Stranski-Krastanow growth mode

The effect of the growth temperature on the density, lateral size, and height of InAs-GaAs quantum dots (QD) has been studied by transmission electron microscopy. With the growth temperature increasing from 450 to 520°C, the density and height of QDs decrease, whereas their lateral size increases; i.e., the QDs are flattened. The blue shift of the photoluminescence line indicates decreasing QD volume. The observed behavior is in agreement with the thermodynamic model of QD formation. The effect of lowering the substrate temperature immediately after the formation of QDs on the QD parameters has been studied. On lowering the temperature, the lateral size of QDs decreases and their density increases; i.e., the parameters of QD arrays tend to acquire the equilibrium parameters corresponding at the temperature to which the cooling is done. The QD height rapidly increases with cooling and may exceed the equilibrium value for a finite time of cooling, which enables fabrication of QD arrays with a prescribed ratio between height and lateral size by choosing the time of cooling.     

Wide-band computer input module

A method and algorithm of adaptive frequency measurements, and the flow diagram of a wide band adaptive computer data input module with frequency range from 7.6 mHz to 64.54 MHz are described.Translated from Izmeritel'naya Tekhnika, No. 3, pp. 18–20, March, 1995.     

On the possibility of determining internal wave characteristics from the ray arrival time distribution in an underwater sound channel under conditions of Ray Chaos

We describe the simplest mechanism of cluster structure formation in the timefront of an acoustic signal propagating in a submerged channel under ray chaos conditions. It is shown that this cluster structure is related to the phase space structure. This relation allows, in principle, the characteristics of an inhomogeneous medium to be determined from the timefront shape parameters. As an example, the period of inhomogeneity is calculated for a periodic perturbation in the sound velocity caused by an internal wave propagation.     

Theoretical Estimate for the Parameters of Ultrasonic Impulses Excited in Geomaterials by Laser Emission

Using the transfer function method as a base, the analytical relations are obtained, as well as the main parameters are calculated for the ultrasonic impulses of longitudinal, transverse, and the Rayleigh waves excited in geomaterials by laser emission.