Error of measurement of coolant temperature in VVÉR-440 reactor

Translated from Atomnaya Énergiya, Vol. 67, No. 5, pp. 358–359, November, 1989.     

Complex design of electromagnetic drives with prescribed dynamic performances

The design principals of fast-operating electromagnetic drives with prescribed dynamic performances are examined. The represented procedure permits the command parameters to be to determined with the guaranteed prescribed parameters of the drive.     

A laser deformometer applied to seismic detector metrological characteristics

A set of standard equipments is considered for reproducing seismic oscillation parameters that have been developed at the Mendeleev All-Union Metrology Research Institute.Translated from Izmeritel'naya Tekhnika, No. 8, pp. 36–38, August, 1993.     

Separation of mixtures and distribution of a liquid on a structured packing in a large-scale model of a distillation column

A large-scale experimental setup is designed to study the hydrodynamic parameters and the mass-transfer efficiency in a countercurrent flow of mixtures of Freon R21 and Freon R114 on structured packings in a column 0.9 m in diameter. The study deals with the local and integral parameters of separation of the mixture, the degrees of nonuniformity of the flow rates and concentration distributions of the liquid and vapor phases over a cross section and on the column wall, and the pressure difference while varying the number of packing layers and their rotation angle. The mass-transfer processes while independently varying the liquid and vapor flow rates over wide ranges are also investigated. Experimental data are presented to illustrate the effect of the operating parameters on the height of an equivalent theoretical plate, the relative pressure difference, and the distributions of the local parameters of the flows.     

Heat transfer in a melt flowing in a short sleeve

An engineering method for calculation of heat transfer in a melt flowing in a short pouring sleeve is proposed. It is demonstrated how the temperature of the sleeve wall varies depending on the velocity of the air flow around the sleeve. The application of a heat-insulating layer of a material with a low thermal conductivity (kaolin wool) makes it possible to decrease substantially the formation of skull.Translated from Ogneupory, No. 3, pp. 20–23, March, 1994.     

MBE of InGaN/GaN heterostructures using ammonia as a source of nitrogen

Technical Physics Letters - InGaN/GaN heterostructures have been grown by molecular beam epitaxy (MBE) using ammonia as a source of nitrogen. The influence of the growth temperature and rate on the...     

Structure and dielectric characteristics of PbFe<Subscript>0.5</Subscript>Nb<Subscript>0.5</Subscript>O<Subscript>3</Subscript> single crystals grown under different conditions

The structure and dielectric and magnetic characteristics of plumbum ferroniobate crystals grown from a solution–melt containing potassium fluoride have been investigated. The obtained crystals have a cubic shape, 4-mm edges, and a rhombohedral structure at room temperature. Iron ions in the samples have the valence state of Fe³⁺. A change in the Mössbauer spectra with a change in temperature has been registered; this is indicative of strong diffusion of the magnetic phase transition in the range from–130 to–230°C, which is enhanced due to incorporation of fluorine atoms into the structure of the basic compound accompanying the synthesis process and clusterization of this structure. The latter phenomena also lead to a decrease in the temperature of transition from the ferro- to paraelectric phase.