The kinetic problem of vigorous mass transfer in a highly porous body with evaporation (condensation) of a substance in it and vapor efflux into vacuum is formulated and solved by the method of mean free path and by direct statistical modelling. A location of the condensation zone inside a porous body is determined in dependence on a temperature drop over an evaporation surface and a porous layer as well as on a condensation coefficient which is of principal importance for development of scientific fundamental principles underlying the power and chemical-technological facilities.
The turbulent mass transfer studies in stable stratified fluids and gases have revealed the existence of quasi-two-dimensional turbulence in air and a quasi-one-dimensional field in a fluid which has been confirmed numerically. A graphical interface is designed for computer-aided visualisation of eddy structures generated in a wall boundary layer.
A multizone system is created and advanced software is developed for diagnostics and investigation of thermal processes in biological objects that has permitted a study of a wide class of objects with a detailed examination of thermal fields and characteristics of the objects in experiment and through numerical simulation.
The influence of diffusive imbibition upon sensibility of penetrant testing has been theoretically investigated. and formulae for the calculation of sensibility threshold are derived. On the basis of thermodynamic analysis of liquid-liquid interaction a criterion of liquid selection for penetrant testing is obtained.
The physical model of the impact interaction of a rigid spherical indenter with elastoplastic material was suggested. On the basis of the model an algorithm of determination of dynamic hardness, modulus of elasticity and coefficient of deformation hardening was designed and realized. The assumed data for the calculation of mechanic characteristics are the momentary values of contact force and area of indentation, which were determined during impact over discrete time intervals.
The experimental dependencies of the electromagnetic transducer higher harmonics on the ferromagnetic material inside residual magnetization are received and applied for the quality control of the surface-strengthened articles in the machine-building.
A series of investigations on theoretical and experimental foundation of passive safe system has been carried out at a large scale plant for atomic power station of a new generation with pressurized water-moderated water-cooled reactor that provides the probability of emergency with radionuclides effluent into the environment at the level of modern world requirements.
For the purpose of early diagnosing of cancer diseases, an ecologically pure wasteless technology of a chemically pure radiopharmpreparation of Technetium-99m production in the form of pertechnetate sodium solution has been developed. The preparation was successfully put under the clinic tests.
A new instrumental method for the control of 241Am radionuclides content in soils and ground deposits based on the registration of the own g-radiation of 241Am has been developed.
Principles of module construction, algorithm of functioning and preliminary laws of control are developed for the microprocessor control system of power-generating set with mechanical gear-box. The modifications of the safety built-in base microprocessor module system of control, protection and monitoring with the elements of self-diagnostics are developed for perspective powerful mobile vehicles with mechanical and hydromechanical transmissions.
A method of analysis of casual multifrequency processes of loading is proposed and theoretically and experimentally substantiated. The most essential new features of the method are the means of schematization of semi-cycles of different loading frequency, transformation of the asymmetric cycles into the form of the symmetric ones, and determination of the parameters of distribution of casual stresses of different frequency.
A new method of investigations and calculation of fatigue resistance of the structures with equistressed surfaces and perimeters of the zones which are dangerous with regard to fatigue is proposed. The method includes the accelerated tests of local models of dangerous zones and the mathematical transition from the parameters of local models' fatigue resistance to those of equistressed dangerous zones' fatigue resistance with the help of tools of the distribution of extreme sample members.
The regularities of the effect of cooling intensity on the structure and properties of the cast materials have been theoretically and experimentally developed.
Some new special types of casting have been theoretically developed and realized -- the continuous casting by method of directed solidification, the continuous casting of the bands and panels on the rall moulds, the iron casting with adjustable thermal resistance on the cast surfaces in the metal mould. The high-efficiency equipment for realizing these processes in industry have been produced.
A study was made of the mechanism of interaction of high energy nucleons (E³1 GeV/nucl.) and light nuclei with light (A<16) and heavy (A>200) nuclei. A method was worked out and a computer code system was prepared for simulating dynamics of hadron-mesonic cascade formation in multicomponent media, containing light, middle and heavy nuclei under high-energy particle beam irradiation. The conditions of preferable realization of energy generation processes, fissile nuclide production and radioactive wastes transmutation on subcritical 'target-blanket' systems of different composition and geometry under 1 GeV deutron beam irradiation were determined.
On the basis of diagonalization of double-electron dipole operator the doubly excited electron states with the main quantum numbers of inner and outer electrons N and n have been investigated, and analytical wave functions and energy of lower states of (N,n)-complex, exact in the range of the high N, have been obtained. It was shown that by N>>1 these wave functions diagonalize the exact operator of interelectron repulsion. It allows to obtain the energy and angular distribution of doubly exited electrons in positive multicharged ions. The double Ridberg formula allowing to calculate non-relativistic bond energy values of two excited electrons both in double-electron ions and in neutral atoms have been proposed.
The passage of the high current electron beam (HEB) through ultrasonic wave in a gas was calculated for the first time. It was shown that frequency of stimulated electromagnetic radiation depends on the sound frequency, the beam energy and its intensity, and the radiation frequency being smoothly changed. Leaving to the submillimeter frequency range is possible already at the sound frequency of dozens of kHz. The interaction of HEB with the acoustic wave may open new possibilities for the plasma physics investigation.
On the basis of modelling the accident at the Unit-4 of the Chernobyl NPP and the balance of materials and radionuclides, the amount and the dynamics of the emergency discharge have been determined. Following the nuclear accident, the isotopes of krypton and xenon have been released into the atmosphere with total activity more than 8 ·108 Ci, and the activity of iodine isotopes is the same order of magnitude. It is shown that the amount of the real discharges of activity significantly exceeds the officially announced 5·107 Ci in 1986.
The criteria for valuing the ecological and socio-economic effectiveness of conducting decontamination and remediation of contaminated with radionuclides territories with allowance for recommendations of ICRP have been developed in order to make Belarus the ecologically safe system. The optimal levels of decontamination of territories contaminated with radionuclides have been determined, and the estimation of natural economic effectiveness of decontamination have been conducted.
The method of scales was used for investigating a flat melt-crystal interface stability during a rapid solidification. The characteristic numbers (of Phekle, Reynolds and Maranthony) and the rate of a melt sliding across an interphase were determined for a disturbed front within the diameter range of self-arranging cells. The conclusion was made that the effect of a concentration-capillary convection is stronger during a rapid solidification than that of a thermocapillary convection.
The phase and structure transformations in ceramic and cermet materials under high-energy exposures were investigated. It was established that a multiple laser irradiation of samples made from high-temperature superconducting yttrium ceramics resulted in the formation of surface periodic structures. The laser beam thermochemical effect which consisted in increasing the ceramics oxygen content was found.
The program medium for designing and realization of cell-automatic models of physical and physical-chemical processes was developed. A considerable number of numerical experiments, which were conducted using a stochastic model of one- and two-stage reactions for a burning without a gas formation (self-propagating high-temperature synthesis), allowed us for the first time with a numerical model to observe a generation of instabilities of a burning front and analyze the types of unstable regimes as well as a transition between them depending on the model parameters. The principles of developing a universal system for statistical modelling by the Monte-Carlo method were formulated.
For the first time the numerical and asymptotic methods for solving the contact problems for anisotropic composite coatings with account for friction have been developed. The methods are based on plane anisotropy theory of elasticity and permit to investigate the contact parameters (pressure, contact area dimensions, depth of indentation, shear coefficient of contact area center) versus anisotropy of mechanical characteristics, base rigidity, coating thickness, visco-elasticity and friction.
The effect of dispersivity and packing density of polymer binder particles on the process of interaction with fiber filler surface has been studied. It has been found out that interphase surface formation is a stepwise process and the change of dispersivity and packing density of polymer particles leads to a shear of temporary boundaries between the stages. The decrease of binder particles size and their packing density increase results in the monolithization acceleration. At the same time it hampers the growth of the contact interaction zone on the interface with fiber filler.
The regularities of changes in physical-mechanical, dielectric, decorative properties and structure of composite polymer materials (coatings, films, blocks) under the effect of high and low temperatures, liquid media and environment have been established. An algorithm of information-prediction system for atmosphere-resistant composites has been developed. The system makes it possible to classify the composites according to their use and conditions of application, to analyze the test results, to compare the achieved results with the accumulated database and give an advice on choice of the materials with the required performances for different climates and within the national and international standards.
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It was found that under pulsed laser deposition of high-temperature superconducting (HTSC) films Y--Ba--Cu--O on substrates Si/ZrO2 the irradiation of condensation surface by additional laser emission with wave length 0.337 mm and power density 10-2 W/cm2 leads to the lowering of temperature and time necessary for film synthesis. The films received by this method have more perfect structure and higher critical parameters in comparison with films received without additional irradiation.
It is established that for topological structures formation in HTSC films the most preferable methods are the 'dry' lithography methods which are based on vacuum processes, namely the vacuum spraying deposition of organic resist film on the substrate with a successive direct formation of a necessary pattern on the film by laser vacuum lithography method (mask formation) and the ion etching of HTSC film through the mask and the mask removal in oxygen-containing plasma. Such methods of HTSC film processing influence in the smallest degree their critical parameters. Besides, the methods give an opportunity to form in HTSC films the bridge structures with sizes smaller than one micrometer.
The three-layer films on the base of vacuum resistors with intermediate metal layer (Al, Mo and TiW) were worked out to increase the masking ability of the masks on keeping high permission. The laboratory process of their receiving was developed. The tests showed that the films having intermediate layer from TiW have the best masking qualities. In such films by laser vacuum projectional lithography method, plasmo-chemical and reactive ion etching the masks with minimal element sizes 0.3-0.4 mm were received.
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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