Free-piston circumfluent-flow gauge and the selection of its parameters

Conclusions The schematic of a circumfluent-flow gauge with a free-piston manometric system has been examined, a method for computing the parameters of this system has been suggested, and an empirical formula for calculating the resistance factor of a body in a flow has been derived. Experimental investigations of a flowmeter model are cited, thus confirming the working efficiency of the instrument made according to the suggested schematic and based on the relationships obtained above.Translated from Izmeritel'naya Tekhnika, No. 10, pp. 35–36, October, 1971.     

Properties of chemically resistant carbon-reinforced plastics

Conclusions The thermal behavior and character of swelling of three carbon-reinforced plastics based on various grades of phenolic resins have been studied in the original state and after service in aggressive media.It has been shown that the molecular weight of the binder exerts an effect on the temperature range and thermal effect of chemical reactions and degradation processes in these materials.The thermal analysis method permits one to determine the difference in properties of carbon-reinforced plastics on change in technological conditions for their preparation, and also to follow the development of degradation processes in carbon-reinforced plastics after service in aggressive media.Translated from Khimicheskie Volokna, No. 1, pp. 13–15, January–February, 1989.     

Laboratory Design of Studying the Coextrusion Process of Profile Blanks from Rubber Compounds

Chemical and Petroleum Engineering - The article considers the design and operation principle of a laboratory unit for studying the coextrusion process of profile blanks from rubber compounds....     

Hydrophobic diamond films

The peculiarities of wettability of diamond that was obtained in a nanostructured form as ultrananocrystalline diamond (UNCD) films by deposition from a gas phase are considered. Surface hydrogenation leads to hydrophobicity: advancing contact angle θ for UNCD films reaches 106 ± 1° (for diamond single crystals θ = 93°). Even higher values of θ equal to 124 ± 3° were detected for nanoporous samples of UNCD, in which a graphite-like component was removed by etching. High hydrophobicity is achieved owing to the specific surface morphology of the nanostructured diamond (anisotropic, with high content of nanopores) and chemical modification, which on the whole provides for very low values of free surface energy of the films. It was shown that laser-drilled microholes in polycrystalline diamond also can enhance the hydrophobicity. The wetting behavior of the nanostructured surfaces agrees well with the Cassie-Baxter equation for heterophase porous surfaces. The oxidation and hydrogenation of UNCD films allows controlling of θ in considerably wider ranges compared to single crystal diamond.     

Asymmetric forced nonlinear precession of magnetization under the conditions for the orientational transition

The forced nonlinear precession of the magnetization vector in the normally magnetized magnetic plate is analyzed under the conditions for the orientational transition in the presence of the asymmetric static field. The excitation conditions for the precession of the equilibrium position of the magnetization vector are determined. It is demonstrated that the precession pattern of oscillations represents a large circular ring filled with small rings with the nonuniform densening whose position depends on the field asymmetry. The precession of the equilibrium position substantially depends on the degree of asymmetry. When the field exceeds a certain threshold level, the precession of equilibrium is changed by the conventional circular precession with a relatively large amplitude. The domains of existence with respect to dc and ac fields are analyzed for the precession of the equilibrium position. The dependence of the precession period on the degree of asymmetry of the dc field is studied. The main features of the above effects are qualitatively interpreted using complementary (energy and vector) models.     

Reclamation of coal preparation dumps

Experiments are conducted to improve the coal preperatiom dumps at PAO Avdeevskii Koksokhimicheskii Zavod and to recultivate and utilize the wastes rock by means of humic preparations from lignite and other wastes rock. Reclamation and utilization of blends of industrial wastes rock proves possible, especially at use of humic preparations.     

Acoustostimulated changes in the density of surface states and their energy spectrum in <Emphasis Type="Italic">p</Emphasis>-type silicon single crystals

The effect of ultrasonic treatment at various powers on the density N _SS of surface states and their energy spectrum in p-type silicon single crystals has been studied. It is established that, depending on the regime of ultrasonic treatment, N _SS can either increase or decrease compared to that in the initial single crystals. This is accompanied by a redistribution of the total charge of the surface states over the silicon bandgap width. This phenomenon is related to the fact that an acoustic wave, being an energy carrier, modifies a defect subsystem of the crystal by redistributing the impurity atoms and by generating new defects.