Using Amplitude Analysis of Acoustic Emission Signals under Cyclic and Static Loading of Steel Samples

Russian Journal of Nondestructive Testing - The results of amplitude analysis of discrete acoustic emission signals from developing sources such as fatigue cracks are presented. The studies were...     

A Study of Chromite Dunites

Results of a study of chromite dunites with different concentrations of chromite — from 10 to 20% Cr₂O₃ — are reported. Thermomechanical properties of control specimens are determined. Chromite dunites require precalcination for their use in the manufacture of forsterite-chromite components for thermal power units of ferrous and, especially, nonferrous metallurgy.     

On the free energy of liquid-metal plasma

The free energy of simple liquid metal in the approximation of the integral smallness of the electron–ion interaction has been found on the basis of the model of single-component plasma as the initial system. The result obtained holds at the equivalency of correlation functions determined within Gibbs canonical and large canonical distributions.     

On statistical theory of rarefied gas in the Coulomb model of matter. Particle identity and effective interaction potential of initial atoms

The free energy of a Coulomb system of interacting electrons and nuclei is studied in the adiabatic approximation for nuclei with allowance for particle identity effects. An explicit expression is found for the effective short-range interaction potential of “identical” initial atoms in the self-consistent Hartree–Fock approximation for the electron subsystem and the first-order perturbation theory in a small parameter defined via the ratio of the atomic size to the mean distance between initial atoms.     

Deformation and strength properties of a carbon–carbide composite with 2D reinforcement under plane stress state

Data of an experimental–theoretical investigation of the deformation and strength characteristics of a carbon–carbide composite with a 2D reinforcement scheme are given. The nonlinear deformation of the material is described using the relationships of nonlinear elasticity of an orthotropic solid. The strength characteristics are calculated by the maximum stress criterion. Calculated deformation diagrams and ultimate strengths are compared with the experimental data of the authors.     

Statistical analysis of electromagnetic compatibility at overvoltage in electric mains

Problems in analyzing the statistical modeling of electromagnetic compatibility (EC) in processes linked with a rise in overvoltage and its development and influence in electric mains are analyzed. Regularities in electric equipment damage and recommendations for electromagnetic compatibility analysis with the Monte Carlo method are presented.     

Energy intensity of a clean break

Institute of Mining, Siberian Branch, Academy of Sciences of the USSR, Novosibirsk. Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 1, pp. 114–118, January–February, 1989.     

Division of supporting-pressure zones

Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 4, pp. 3–11, July–August, 1995.     

Structural studies of a ferromagnetic GaMnSb layer

The crystalline structure and composition of a GaMnSb film is studied. The film is produced on a GaAs (100) substrate by deposition from laser plasma in a hydrogen flux at a temperature of 400°C. The formation of GaMn inclusions in the GaSb:Mn matrix is detected. The stoichiometry ratio of the inclusions corresponds to that of the Ga_162.5Mn_101.5 compound.     

Acoustic-emission testing of solebars with boxlike cross sections

The changes in the design of the 18–578 solebar with a boxlike cross section required the development of a new scheme of arrangement of acoustic-emission (AE) transducers and improvement of both technique and software. All sources that were detected during AE testing were divided according to their degree of hazard into passive and critically active ones. Location grids that specified the rejection levels were imposed on the tested zones under study. In the refined technique, linear location was used, which made it possible to preserve the reliability of the investigation results and reduce the labor intensiveness of the AE testing.