Hydraulic resistance and heat transfer in an annular channel with rotating flow

The results are given of an experimental study of the hydraulic resistance and heat transfer between the inner wall of an annulus and a rotating axial air flow through the annulus.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 21, No. 1 pp. 38–42, July, 1971.     

Sublimation of ice in coarsely dispersed rocks subject to quasiisothermal conditions

The results of a theoretical and experimental investigation into the sublimation of ice in coarsely dispersed rocks are presented.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 30, No. 4, pp. 640–645, April, 1976.     

Mathematical modeling of polymerization in the manufacturing of polymeric composite materials

The temperature distribution in an item of composite materials in the manufacturing process depends not only on the heating intensity, but on the intensity of heat released in the process of polymerization as well. The mathematical model of polymerization of composite materials on the basis of thermoreactive binding is described.     

Effect of alumina nanoparticles on the structure and physicochemical properties of chromium coatings

The results of research into the structure, chemical composition, and main functional properties of electrodeposited chromium-based nanocomposite coatings are described. The nanodispersed phase that provides an increase in the microhardness, wear resistance, and corrosion stability of the resulting coatings is determined. The percentage of the main chemical elements in the electrodeposited chromium-based nanocomposite coating are found.     

Methods of measuring activation and passivation potentials of Fe-Cr alloys

A novel experimental method of estimating the activation potentials of passive layers on metallic materials is developed taking into account the advantages and drawbacks of conventional methods (switching off the anodic polarization and reverse potentiodynamic activation-passivation). Theoretical principles of the proposed method of successive approximations are based on the thermodynamic possibility of forming a passive layer on the alloy surface. The method involves potentiostatic exposures in the potential range of presumable activation. The change in the current direction with time at a selected potential is considered to be an indicator of the surface state. The error of measurements is related solely to the accuracy of potentiostat and is independent of a particular mechanism of the passive layer formation. The method is supported by the example of Fe-Cr and Ni-Cr alloys, as well as 4541 steel X6CrNiTi18-10, AISI 321. The experimental data obtained are compared to the results of theoretical calculations of Flade potentials.     

The optimization of the production process for electrical insulation systems

Ways to optimize the production processes for slot and turn insulation are proposed.     

High-pressure methane accumulation in a carbon fibrous sorbent

Recent data on methane adsorption on C300 carbon-fibrous sorbent obtained in the pressure range of 1 to 55 MPa and temperature range of 303 to 333 K are reported. Methane adsorption isosteres in the same ranges of pressures and temperatures were calculated on the basis of experimental isotherms of methane adsorption. Differential molar isosteric adsorption heats were calculated as a function of the value of methane adsorption and temperature. Dependences of methane adsorption on the C300 adsorbent on pressure were calculated on the basis of the Dubinin theory of volume filling of micropores and compared with experimental data. The best agreement between the results of calculations and experimental data was found at the intermediate range of pore filling.     

Preprocessing of alphanumeric images to be recognized by autonomous computing systems

Methods and algorithms for digital image processing that increase the probability of correct recognition of alphanumeric data are considered. The computational costs of the control block of an autonomous image recognition system based on TMS320C5416 signal processor are analyzed. Natalia S. Novozhilova. Born 1955. Graduated from Moscow Institute of Electronic Engineering in 1978. Received her candidate’s degree (Mathematics and Physics) in 1984. At present, she is a senior researcher at Lukin Scientific Research Institute of Physical Problems. Scientific interests: pattern recognition and mathematical methods for processing the results of a physical experiment. Author of 22 publications. Aleksandr G. Safonov. Born 1952. Graduated from Moscow Power Engineering Institute in 1975. Received his candidate’s degree (Technical Sciences) in 1982. At present, he is a head of department at Lukin Scientific Research Institute of Physical Problems. Scientific interests: automated data processing complexes, pattern recognition, and microelectronics. Author of more than 50 publications.     

Ultrasonic defectoscopy of joints in sectional monolithic hydraulic structures

Conclusions These experiments make it possible to recommend the ultrasonic impulse technique in checking and defectoscopy of connecting joints in sectional monolithic hydraulic structures. This technique yields industrially reliable results without disturbing the continuity of the structures. Ultrasonic defectoscopy of joints was adopted as a principal mass-application checking method in construction of the Saratov Hydroelectric Station. Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 7, pp. 19–23, July, 1968.