Investigation of heat exchange in the water-spray cooling of high-temperature metal surfaces

A method is described and certain results presented of an experimental study of local heat exchange in the forced cooling of metal surfaces heated to high temperatures.Notation l distance from nozzle to heated surface - x, y horizontal and vertical coordinates in the field of the jet, read from the geometric center of the jet - V volumetric flow rate of water through the nozzle - p excess pressure of the water in front of the jet - F₀ area of sprayed surface of specimen - F_c area of unsprayed surface of working part of specimen - t temperature of sprayed surface of specimen - t_w temperature of the water entering the nozzle - N, N_c power required to heat the working part of the specimen to a given temperature with and without the spraying of water onto the surface, respectively - g local spraying density - local heat-transfer coefficient Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 39, No. 2, pp. 315–322, August, 1980.     

Optimization and control in some ecologo-economic models

An approach to the optimal control problems was described by way of example of some ecologo-economic models. A three-level system of models for prediction of the regional ecologo-economic processes was presented. The problem of optimal control was formulated for the biological resource models of the second and third levels. The results of computer experiments were cited.     

Determination of the temperature field of a metal barrier in collision with an erodent particle

A numerical model that allows the study of the nonstationary temperature field of a metal barrier in the vicinity of a crater formed due to inelastic impact of a solid spherical particle is considered.     

Two-step syntheses of rare-earth diborides

A two-step process has been proposed for the preparation of refractory rare-earth diborides: high-temperature high-pressure elemental synthesis followed by argon annealing. Using this process, we have synthesized terbium, erbium, thulium, and lutetium diborides containing no more than 3 wt % impurity phases.     

Primary measuring transducer for determining magnetic dipole moment

The features of a new primary transducer, designed to measure two components of the magnetic dipole moment vector, are considered. The transducer has an extremely simple construction. Using it, one can eliminate relative errors of the displacement of this vector, which reach 10–20%. The measurement equations and an original formula for calculating the magnetic flux are obtained. Translated from Izmeritel'naya Tekhnika, No. 2, pp. 44–48, February, 1998.     

Characterization of B4C-SiC ceramic composites prepared by ultra-high pressure sintering

Additive-free boron carbide (B₄C) – silicon carbide (SiC) ceramic composites with different B₄C and β-SiC powders ratio were densified using the high-pressure “anvil-type with hollows” apparatus at 1500 °C under a pressure of 4 GPa for 60 s in air. The effect of starting powders ratio on the composites sintering behavior, relative density, microstructural development, and thermomechanical properties was studied. The sintered samples hardness was found to be in the range from 24 to 31 GPa. The thermal conductivity measurements, conducted in the temperature range from room temperature to 1000 °C, showed that the thermal diffusivity of sintered samples was between 6 and 9.5 mm²/s whereas the thermal conductivity was in the range from 16 to 28 W/(m K). The results of this study show that the high-pressure sintering can be a very effective low-temperature densification method for the obtainment of additive-free B₄C - β-SiC ceramic composites.     

Methods of improving the quality of desulfurized conversion pig iron

Institute of Ferrous Metallurgy. Translated from Metallurg, No. 6, p. 26, June, 1989.     

A structural analysis of the BRS1 repeat from the genomic DNA of barley (Hordeum vulgare L.)

The paper presents the results of analysis of the primary sequence of repetitive barley DNA called BRS1 (index number in Genbank BRS-1 U72261). The sequence encodes the open reading frame for 337 amino acids which has homology to retrotransposon-like element of Arabidopsis. There is a block consisting of 11 direct and 7 inverted repeats outside the open reading frame, the sequence ATACTAATGGCGCACC being the base of the repeats.