Calculation of particle dynamics in the nonradiative model of plasma

The work discusses the implicit difference scheme for the equations of particle motion accounting for peculiarities of the Darwin approximation of plasma. The aspects of its consistency, accuracy, and stability are investigated, and the adequacy of conveying major physical effects, related to the motion of charges in an electromagnetic field, is demonstrated. On the basis of the scheme, an optimal numerical algorithm is proposed and its efficiency is considered.     

Detailed comparison of the performance of flat-plate and vacuum tube solar collectors for domestic hot water heating

The performance of a DHW system fitted with flat-plate and vacuum collectors has been analysed. Simulations were carried out on the basis of equal aperture or gross areas of basis using TMY data for hour-by-hour dynamic simulation generated for 1036 sites located in different regions of the world. The performance indicators of solar fractions and number of days were determined for specific water mean temperatures in the storage tank of 37 °C, 45 °C and 55 °C. It has been shown that vacuum tube collectors provide slightly better DHW performance indicators than typical flat-plate collectors having the same aperture area. However, since the space that needs to be provided and directly or indirectly paid for is what matters to the user of solar heating systems, the analysis was also carried out on equal gross area basis; on this basis, the advantages of using vacuum collectors are not obvious.     

Vortex jet transport of ions from a source to mass spectrometer input at atmospheric pressure

A new system of transporting ions from distributed sources to the input hole of a mass spectrometer by a strongly swirled gas jet at atmospheric pressure is proposed. It is shown that the vortex jet transport provides for a more than hundredfold increase in the mass-spectrometric peak intensity, depending on the nature of ions. The effective input aperture for ions increases by three orders of magnitude, which ensures a more complete collection of ionized sample species from distributed ion sources of large volume.     

Production by various methods of composite materials based on a hard metal with cubic boron nitride

Conclusions During the production of the composite materials under consideration by orthodox sintering the cubic boron nitride and hard metal react with each other, with the formation of borides and appearance of porosity as a result of the evolution of gaseous reaction products, and the strength of the materials is therefore low. During hot pressing the reaction between the components of the CBN-containing materials is less intense because the sintering temperature is lower and the holding time shorter, but the strength of the resultant materials remains comparatively low. The most promising method of obtaining composite CBN-containing materials exhibiting high abrasive ability in the grinding of hard and brittle materials is shock sintering.Translated from Poroshkovaya Metallurgiya, No. 3(243), pp. 43–45, March, 1983.     

Features of skeletal composite compaction and sintering

Skeletal composites are prepared using highly porous cellular nickel as a volumetrically-bonded framework and features of their compaction and sintering are studied. The skeleton improves composite compactability and may slow down volumetric changes during low-temperature sintering, but it does not affect them during high-temperature sintering. In compacts of skeletal composites at skeleton-ceramic boundaries there is formation of pores that by growing during sintering form a volumetric network of microcracks. __________ Translated from Poroshkovaya Metallurgiya, Nos. 7–8(450), pp. 10–18, July–August, 2006.