Development and introduction of a technology for making strip used for the support plates of copper-brass heat exchangers

The production of Kuprobreiz heat exchangers has been made more efficient by the introduction of a new technology at the Kirov Nonferrous Metals Plant for the production of 0.8–1.0 mm strip composed of new brass LN64-3.     

Two algorithms for approximate construction of the set of positional absorption in the game problem of pursuit

Consideration is given to the differential game on the finite period of time in which the first player has to guarantee that the phase point will entry the terminal set and the second one must ensure the evasion of the terminal set on this interval. Is proposed a method for approximate construction of the set of positional absorption, i.e, the set of all initial points for which the problem of pursuit posed for the first player is solvable. The method is based on unification constructions and structures close to them. Relations defining the system of sets that approximates the set of positional absorption are written out. The convergence of the approximating system to the set of positional absorption is proved.     

Chemical and Engineering Corrosion Protection for Equipment in the EDU–AVT Plant

The chlorides (both inorganic and organic) and sulfur compounds in crude oil entering a refinery corrode the equipment, primarily condensers and coolers, due to their hydrolysis and cracking during primary distillation of the crude oil. The process stability of the units decreases as a result, and this does not allow increasing the interrepair periods and increases the cost of repair work.     

Modification of quantum dots in Ge/Si nanostructures by pulsed laser irradiation

The goal of this study was the development of a method for the modification of a quantum dot (QD) structure in Ge/Si nanostructures by pulsed laser irradiation. The Ge_xSi_1?x QD structures were analyzed using data furnished by Raman spectroscopy. Frequency-dependent admittance measurements were used to study the energy spectrum of holes in the Ge/Si heterostructures with Ge_xSi_1?x QDs before and after the laser treatment. The obtained experimental data show that laser treatment makes it possible to reduce the sheet density of QDs, modify their composition, and increase the average size. The most important result is that the QD parameters become more uniform after the treatment with nanosecond laser pulses. In a sample with ODs of 8-nm average lateral size (six monolayers of Ge), the scatter of energy levels in the QD array is reduced by half after the treatment with 10 laser pulses.     

Method of determining the thermophysical properties of orthotropic materials from the solution of a two-dimensional inverse heat-conduction problem

An unsteady two-dimensional inverse coefficient problem of heat conduction is formulated mathematically and solved.Translated from Inzhenefno-Fizicheskii Zhurnal, Vol. 56, No. 3, pp. 483–491, March, 1989.     

Modeling trans- and supersonic viscid flow over a cone on a ballistic range

The possibilities of ballistic-range experimentation in determining the influence of compressibility and viscosity on the flow over cone-shaped parts of flying vehicles are considered. A nonmonotonic character of the dependence of the near wake flow over cone on the Reynolds number is revealed, which is an important factor under natural flight conditions. Tests have been performed for a right circular cone with a half-angle of 15°. The drag coefficients (C _x ) for acute and blunt cones with an aspect ratio of L/D = 1 at a zero attack angle have been determined. Near wake flow parameters (base pressure p _b and base density ρ _b ) have been experimentally studied in a range of Mach numbers M_∞ = 0.5?4 and at a fixed value of M_∞ = 2.3, but with Reynolds numbers Re_∞D varied from 6 × 10⁴ to 1.5 × 10⁶.