On Temperature Effects in the Correlation Functions of a Degenerate Electron Plasma

It is shown based on explicit expressions for structural factors and longitudinal and transverse permittivities of degenerate electron plasma within the ideal-gas approximation that temperature effects should be taken into account in these functions to correctly describe the region of small values of wave vectors and frequencies.     

Thermoluminescent dating of archaeological pottery

This paper describes a thermoluminescent technique for dating archaeological pottery without isolating quartz from objects of dating. The technique employs TLD-K soil-equivalent thermoluminescent SiO₂-based detectors for measuring the test dose of artificial irradiation and the background dose rate on the dig site.     

Enhancement of the acoustic-emission method use for diagnostics of rolling stock cast parts

The techniques for acoustic-emission (AE) testing of cast parts (side frames and bogie bolsters) of a freight-car truck, which improve the reliability of evaluating their engineering state at different stages of the working cycle and decrease their repeated rejection, are considered. It is proposed to determine the degree of damage and the service life of cast parts on the basis of the analysis of AE-signal sources, which have the highest integral characteristics.     

Modeling the instability of the boundary of a dielectric liquid with a free surface charge

We have numerically modeled the development of instability of the boundary of a nonviscous dielectric liquid with a free surface charge occurring in an external electric field and compared the behavior of this system in the two limiting cases, whereby the surface charge produces complete screening of the field above and below the surface. Although the linearized equations of motion in the two cases coincide, the scenarios of instability development are substantially different, which is indicative of the determining role of nonlinearity in this process.     

Investigation of deep methane oxidation with the use of the improved flowing circulation method

The most correct method for studying the peculiarities of stationary kinetics of heterogeneous reactions is the flowing circulation method which has been substantially improved in recent years. The core of the introduced improvement lies in the direct determination of reaction velocity (catalytic activeness) at the given compound of the contact reaction mixture. The improved flowing circulation method was applied for the first time to study the deep oxidation of methane by molecular oxygen in order to obtain one-parameter dependences of catalytic reactivity on the temperature and concentration of reaction medium components and the solution of the inverse kinetic problem. Catalyst IK 12–72 compound, wt %: 16 ± 2 Cr₂O₃, 4 ± 0.6 MgO and the remaining Al₂O₃ has been studied. In the kinetic area, the apparent energy of reaction activation (110 kJ/mol) has been determined. On the basis of experiments and ideas on the mechanism of the Langmuir-Hinshelwood reaction of competitive absorption type, the equation well describing experimental data in the overall studied range of concentrations (average relative deviation 8%) was selected. The simplicity of the improved flowing circulation method allows for it to be recommended for the selection of the most active catalysts and analysis of dependences of stationary velocities of heterogeneous catalytic reactions on various process parameters.     

Nondestructive test methods in making and using vessels and plant

Diagnostic features are considered for the following: an ordinary vessel made of mild steel; a vessel with a jacket; a vessel made of corrosion-resistant steel; a vessel made from a bimetallic material; and enameled apparatus. The ultrasonic reflection coefficient is related to the thickness of the intermediate layer at various frequencies and various ratios of the scale thickness (oxide film) to the wavelength, and a study is also made of the dependence of the reflection coefficient for longitudinal waves on the layer thickness for lead, zirconium, and copper.     

Effect of tempering temperature on the mechanical properties of high-strength tool steel

Conclusions Steel D7KhFNSh is suitable for manufacturing parts operating under conditions of compression. The best combination of mechanical properties in compression is obtained by oil quenching from 840° and tempering at 170–200°.I. M. Gubkin Moscow Institute of the Petrochemical and Gas Industry. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 6, pp. 48–49, June, 1978.