The analytical studies of the dynamics of the weak, stratified with respect to a liquid density, homogenous turbulence have allowed the relations to be obtained that make it possible to explain the anomalous behaviour of the weak turbulence in a gravitational field and to realize a quasi-one-dimensional disturbed velocity field at high molecular Prandtl numbers.
Based on experimental and theoretical studies of heat and mass transfer involving phase changes and of the fluid dynamics of swirled flows, the velocity and temperature fields in different zones of an evaporative cooling tower are determined and the ways to improve its efficiency are proposed. The physical-mathematical model is proposed for the processes of substance deposition from a gaseous phase in a plasma-chemical reactor and melting of the obtained porous germanium (or silicon) layer.
The method is worked out to increase the combustion (gasification) efficiency of highly moist low-grade solid fuels and their wastes by intracyclic fuel drying in a fluidized bed of an intermediate heat carrier with an account of the revealed specific features of heat and mass transfer involving combustion both of separate particles and within the entire bed space.
The technique of superadiabatic oxidation of organic pollutants of exhaust gases of industrial plants is elaborated. The experimental setup designed on its basis has allowed the 99% decontamination with the energy consumption by 20 times less than in the case of direct reburning.
The mathematical model of the process of dynamic system (technological process) functioning in interaction with the process of emergency evolution is suggested. On the basis of the theory of sporadic structure systems a method of investigation of the model is worked out. The main control principles of dynamic system (technological process) that ensure minimum risk of emergency evolution are discovered. The algorithms for discovery of random failure of dynamic systems are worked out, and the methods of prediction of the emergency conditions are formulated.
A new digital method for the reconstruction of distribution diagrams of tested parameters over the depth (stress, hardness, carbon content, etc.) in a surface layer of hardened steel and iron articels is worked out. The method uses the diagrams of layer distribution of tested parameter for the series of standard hardened pieces as a basic a priori information for real time integral equation. The method extends the region of magnetic noise tomoscopy using for optional hardening mode (e.g. surface impregnation, thermal hardening, hardening by concentrate heat source and other).
A new method for modelling of adhesion joints from polymers with different strengthes based on using of fine dispersive powders from materials that are not wetted by polymers in liquid is worked out. The effect of change of image angle by scanning of plane boundary of jointed materials in the place of defect of adhesion joints is disclosed. The possibility of testing the defects of 'sticking together' type in the place of welding of polyethylene materials by analysis of shadow and echo-pulses at big angles of introducing the ultrasound pulses relative to the plane of sticking together is revealed.
On the basis of the earlier developed binary-regenerative gas-vapour cycle with intermediate superheating and overexpansion of a working body an original design of vapour-gas turbine plant was suggested. The mobile, economic (with total efficiency of 85%) and ecologically pure plant provides the reliable heat supply with the possibility of peak steam output increase up to 250--300% against the nominal one even at accidental shutdown of gas turbine engine and complete failure of energy supply.
A new method and a design of a combined system of accidental cooling of nuclear reactor have been developed. The system operates in the absence of all the types of energy supply and control and provides the increase of heat power of safety system by 350% and more that excludes the coolant effluent into the environment during all the stages of the emergency with full de-energizing of the station.
A new method for the control of the content and dynamics of a-emitted nuclides in soils has been developed. The method is based on a direct exposition of nitrocellulose solid detectors of domestic production with their further chemical treatment for detecting tracks of a-particles and their counting. The characteristics of nitrocellulose detectors of a-particles have been studied, the regimes of their chemical treatment have been chosen, and the automatically controlled spark couter for counting tracks on the detector has been created.
The influence of the cyclic deformation on the X-rays extinction in the typical Ni-Cr base age-hardenable alloy was revealed. The role of the crystalline structure defects and the elastic interphase deformations in the extinction weakening and amplification during cyclic tests was shown.
The distinctions of the processes of accumulation of damages in the steel specimens with hard alloy coatings from the classical theory of failure of structural materials were established. In particular, it is shown that during torsion the cracks appear from the pores by the directions which are perpendicular to the plane of the maximum tension stresses that is explained by the fragile micromechanism.
The principles of conceptional and methodological structure of the complex for estimation and ensuring of mobile vehicles reliability were formulated on the basis of experimental and statistical data analysis of the multilevel tests results and on the basis of calculation and analytical simulation of operational properties of machines.
A new production process and an equipment for continuous casting of the plate grids in the coil are developed.
A method for calculation of the nuclear power systems on the base of thorium molten salt fuel have elaborated. Such nuclear power system consists of proton accelerator breeder (300 MW power) and nuclear power plants (350 MW power). The analysis of cycle of such system have been carried out, and the optimum conditions for 233U production and 239Puburning up at self-supplies of the accelerator by power have been defined.
The physical model was developed allowing to describe adequately the processes of aerosol particles transfer, sedimentation and coagulation in the case of developed large-scale convection under the protective reactor containment. The model is based on the description of the gas and aerosol particles motion under the assumption of one-sided interaction. The application borders of the model developed were established.
The physical-chemical model of radiolysis of the multicomponent gas mixture on the basis of air affected by accelerated electrons was worked out. A mathematical program was created and the calculations in wide region of temperature changes, doses and dose rate were carried out. On this basis the optimum parameters for the most effective cleaning of flue gases of thermoelectric power stations from pollutants (SO2, NO) by using of accelerated electron beams were determined.
The dynamics of change of the total activity in the Republic of Belarus, amounting to 106 Ci in 1993, has been determined. The change of the composition of radionuclides which determine the radiological situation has been evaluated. It is found that 137Cs, 34Cs, 90Sr, 125Sb, 106Ru, 144Ce, 239Pu and 240Pu have been the main contributors to radiological situation in 1993. The increase of americium activity is also forecasted.
The investigation was made of a charge carriers motion in a thin semiconductor layer of a metal-dielectric-semiconductor microstructure with periodic field electrodes which occurs during a superposition of crossing non-uniform high-frequency electric and uniform magnetic fields. It has been established that under the certain conditions a quasi-zero-dimensional object appears in this structure. It is known as 'a quantum dot' and characterized by a specific property which lies in the fact that an energy spectrum of charge carrier is completely defined by external electric and magnetic fields. Such structure can serve a basis for the development of micro- and nano-electron devices of a novel type.
The vacuum ion-plasma coating on the base of titanium refractory compounds which are formed in heterophase reactive media were investigated with regards to their protective and decorative properties. It has been found that according to the Movchan-Demchishin-Tornton classification the coatings of this class have a columnar structure in the form of crystallites grown together and characterized by a closed porosity which ensures their increased protective ability in aggressive media.
The theoretical foundations of a dispersion process of metallic material structures which occurs during an intensive shearing and rapid heating have elaborated. The suggestion was made of the basic models for accumulation of dislocation and disclination defects. The models of accommodation rearrangements proceeding under the effect of deformation and heat were designed using the tools of structure micromechanics. As compared to power-consumable methods of powder metallurgy this provides new possibilities for producing compact materials with preset controlled properties.
The optical-electronic scanning technique was first used to study temperature distribution across the surface of real contact spots. It is shown that the temperature gradient on a spot can reach 104 -- 105degree/mm, thus leading to high temperature stresses in its vicinity. The theory of steady distributions was attracted to develop a statistical model of temperature flashes, capable of evaluating the condition of rough frictional contacts with regard for the influence exerted by surface heat sources. It has been verified experimentally that local volumes of one of the mated materials turn to molten state, a correlation exists between maximum temperatures on the spots and their size, the sliding velocity affects the coordinates of local temperature maximum.
An algorithm and basic programs for modeling contacts of solids were elaborated by using scanning probe microscopy observations. Submicroreliefs on metal surfaces (steel, aluminum, silver) subjected to mechanical processing, friction and damage were evaluated qualitatively and quantitatively. The surface topography transformations on micro- and submicroscales are shown to be associated with variations in the grain and subgrain structures of metals.
The polymer fibrous filter materials containing magnetohard disperse fillers (barium or strontium ferrite) were designed. It was shown for these materials that the efficiency of cleaning liquids from ferromagnetic and non-magnetic impurities is higher if compared with non-magnetic materials. This is explained by the fact that under effect of local magnetic fields, impurity particles found in the fluid to be filtered get coagulated. A mathematical model of ferrite-filled fibrous filters was designed and implemented via software.
The investigations of the thin nonconductive silver films structure, sputtered on a glass, the influence of a chemical composition of the Ni-B films on surface roughness and relief structure of the different areas of the integrated circuits have been performed with atomic force microscope (AFM). The method of the structure of thin fibres investigations using AFM has been developed. The obtained pictures analysis makes possible to determine the fibre curvature radii in two orthogonal directions, the cylindrical form declinations and the fibre surface roughness.
The industrial polycaproamide fibers were modified by 15 different species of bacteria and by 6 species of fungi. The treated fibers have been investigated by the methods of scanning electron microscopy, atomic force microscopy, X-ray structure analyses, electron paramagnetic resonance, and infrared spectroscopy. The physical and mechanical properties and adhesion to the polyethylene and rubber were measured. It was found that some species of the microorganisms can increase the fiber strength by 15-20%, improve the adhesion to the polyethylene by 50% and lower nonreversible thermal expansion by 50%. The data obtained made it possible to select the most active for polycaproamide fibers microorganism species and to propose the way of the study of microorganisms interaction with the surface fiber.
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The experimental investigations were done with the aim to determine the influence of condensation surface quantum activation during HTSC films deposition on phase composition, structure and electrophysical qualities of the films. There was found out the effect of synthesis temperature decrease by 200 C of 1:2:3 phase for Y-Ba-Cu-O films under the substrate surface and growing film surface activation by laser emission with wave length 0.337 m under power density of W/cm.
Source: "Main Results of Fundamental Research.1992--1993". Eds. A.M.Goncharenko and N.N.Kostyukovich. Academy of Sciences of Belarus, Minsk, 1994
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