The work objectives are to generalize the scalarization method of dynamic elastic fields in the transversely isotropic media to the tasks for the environments rotating with a constant angular velocity, and to develop the methodological apparatus for describing the effect of rotation on the parameters of surface acoustic waves. On the basis of this method, the scientific-methodical device for the construction of new acoustic-wave gyroscopes is proposed. Parameter determination ratios for surface-acoustic waves (SAW) propagating on the boundary of the rotating half-space of the transversely isotropic material with arbitrarily spaced axis of material symmetry are obtained and validated. An example of the numerical simulation for the isotropic rotating half-space case is given. The proposed methodological apparatus and numerical simulation examples can be used to develop new types of gyroscopes on acoustic-wave systems for navigation, guidance and control of various mobile objects in aviation, robotics, etc

The work objective is to study new application methods based on the resource-saving technologies for nanostructured coatings with different functionality. The main task of the work is investigating modern efficient methods to increase strength, corrosion resistance, and wearability. The subject of study is high-speed application methods for anti-corrosion and wear-resistant coatings that significantly improve the durability and reliability of products. Design, technological features, specifications, and a scope of applicability of various installation models for high-speed deposition methods, including a gas-plasma technique, are described. The analysis results of the basic physical, mechanical and performance properties of the coatings obtained with the compact high-performance process equipment are presented. As a result of this work, it is shown that coatings obtained by the high-speed methods, unlike the subsonic methods, are characterized by the high performance. The paper also presents perspectives for development of the processing methods of the multifunctional coating application, the improvement of equipment and materials. The data obtained can be used for designing processes of applying dense coatings of consistent quality on the complex products made from nearly all metals and alloys. The results obtained are applicable in the mechanical engineering, repair production, aviation, energy engineering, etc.

The work objective is to study the surface notch impact on the liability of the heat affected zone (HAZ) of welded joints of the heat-resistant high-alloy steels to brittle intergranular fracture. The theoretical justification is presented, and experiments that demonstrate the mechanism of this effect are described. The impact of the notch acuity of Charpy- and Mesnager-type on the welds life of 12H18N12T, 07H18N9 03H16N9M2 steel at high-temperature (T = 823K) low-frequency low-cycle loading simulating the conditions of a non-stationary operation mode of the equipment and pipelines of the nuclear power plants with fast-neutron reactors is investigated. It is found that the welds of the steels under study exhibit different notch sensitivity depending on the plastic properties and liability to the HAZ metal dispersion hardening. As a result of the work, the significance of the high ductility of the austenite grains free from the second-phase dispersed precipitates reinforcing matrix is shown by experiments. The high resistance of the metal of the HAZ of 03H16N9M2 low-carbon steel from the intergranular fracture is due to this factor. The findings lead to the following conclusion: “minor” surface notches - technological defects such as notch groove, lack of fusion, tear - are unacceptable when operating with welded joints of heat-resistant steels under the high-temperature low-frequency low-cycle loading.

The work objective is to determine the effect of the metallurgical properties of iron-rich pellets and of the method of their submission to the arc furnace bath on the intensification of the heating and melting of the iron metallized pellets (IMP) in the slag-metal melt unit. A method of supplying pellets through the electrode axial passages that allows, simultaneously with the pellets, feeding supplementary bulk materials (lime, coke fines, scale, etc.) to the IMP melting zone through the holes in the electrodes is offered. Thus, the conditions of the full immersion of the arcs into the formed foaming slag are provided. The effect of iron oxides of various phase and chemical compositions on the plastic properties of pellets is investigated. It is found that the microstructure invariance of fluxed pellets including the bonded phase composition is determined by the level of fluxing and the difference of the iron valent states. Improvement in the efficiency of IMP melting is achieved by feeding pellets with improved physicochemical and technological properties, as well as supplementary materials, into the slag-metal bath through the axial passages of the electrodes.

Methods for obtaining ultrafine copper powders from the etching waste of the printed circuit boards are described. Modes of obtaining copper powder in the anode-synthesized chloride-ammonium electrolyte using vibrocathode that allows intensifying the process as compared to the similar one at the stationary cathode by reducing diffusion layer are described. The productivity of copper powder obtaining in the offered terms is 0.25 g/(cm²·h), mean particle size is 3-4 microns. High efficiency of the process compared with the use of sulphate electrolytes, and a positive effect of the shape and size of the obtained copper powder on the processes of alloying Fe-based materials are reported. Properties of the antifriction materials doped with the obtained cathode copper powder in comparison with the materials alloyed with the PMS-1copper powder are considered. The effect of the working properties improvement of the samples doped with copper powder obtained from a copper-ammonium solution is observed.

The work objective is to develop a method of the dynamic link libraries mechanism application with aprior unknown number and type of the exported functions parameters of DLL on the example of the information system “Channel”. The system “Channel” allows simulating the noise-immune digital communication channels and solving the problem of matching the communication channel and the algebraic method of the jamproof protection of this channel. The main feature of the system is that it can be used not only by the researchers who do not have programming skills, but also by experts in the computing aids programming. The first-mentioned group can use the existing system software, and experts can further develop and connect their own libraries to expand the capabilities of the information system. Problems that arise when expanding the information system functional by the third-party developers through the DLL technique are described. The main difficulty is the prior uncertainty in the names, parameters, and parameter types of the DLL external functions. The problem-solving technique for the of third-party libraries connection developers is the master program abstraction from the data used by the plugins, the unification of requirements to the external libraries, the supply of each library with a special description file, and the creation of the input parameter editing procedure for each library. The result is a quality operation of the information system “Channel” with the external libraries under observing a number of agreements by the DLL developers. The conclusion is made that the resulting solution can be used in other systems as well. Ключевые слова: информационная система, ИС «Канал», динамически подключаемые библиотеки, помехоустойчивый канал связи, расширение системы, внешние функции, сторонние разработчики, DLL. Keywords: information system, “Channel” IS, dynamic link libraries, noiseless communication channel, system expansion, external function, third-party developers, DLL.

An algorithm for constructing test materials and the test results evaluation techniques that allow combining high estimate rate and test objectivity are developed. The test system in this case can be considered as an assessment tool for the knowledge level under investigating the appropriate modules. The decomposition of knowledge into lots of sections is conducted for the knowledge systematization. At that, each section is associated to a set of sub-sections which, in turn, consists of a subset of questions, the answers to which reveal the level of knowledge of each section. The test assignment is formulated in such a way that upon answer, a set of responses revealing the knowledge level of a certain subsection is to be given. Since the test development process is considered as a construction of multivariable dependence, it is proposed to approach the problem from the perspective of planning multifactor experiments. In this case, a set of answers is presented as a set of factors taking on certain values. With their varying on two levels, the problem is reduced to the construction of the experiment that implements all possible combinations of factors, i.e. to a complete factorial experiment. The technique of applying the technology of two-level multifactor experiment planning that allows formalizing the evaluation of partially incomplete knowledge, and implementing the formation of the multifactor tests of different kinds of complexity is offered. To illustrate this technique, the examples of the construction of tests for the discipline “Automatic control theory” assessing the degree of the knowledge level formation are considered. The statistical analysis of the test results has shown the knowledge level of the testees, as well as the credibility of this knowledge.

Feasibility of genetic search algorithms application for implementation of the cryptanalysis of block cipher methods is considered. A distinctive feature of the bioinspired cryptanalysis methods application (in particular, genetic methods) is the possibility of using the encryption (or decryption) algorithm as an objective function for the suitability evaluation of the key defined by genetic operations. Consequently, when using the bioinspired cryptanalysis methods, the S key definition (for example, when using type 2 cryptanalysis) depends not so much on the complexity of the ciphering transformations, as on the bioinspired method which is to provide a sufficient variety of key generation that shows the significance of the research task of the bioinspired algorithms feasibility (in particular, genetic search methods) for the block cryptosystem cryptanalysis. It is noted also that as the distinctive feature of both block cipher methods, and the genetic algorithms is their internal parallelism, then the task of developing a cryptanalysis algorithm based on the parallel implementation of the constituent stages is relevant. An algorithm of the block methods cryptanalysis on the example of the DES standard on the basis of its parallel version is offered; the experiment results of the quasioptimal key determination obtained at the parallel algorithm implementation on the 8-letter text blocks are given. It is noted that time costs of the algorithm realization do not exceed the time of the known cryptanalysis implementation.

The work objective is to study the fundamental parametric solutions to create the equipment for the oxygen enrichment of water in the closed water systems in recycling. It is assumed to achieve the effect of disinfection excluding the addition of oxygen into water from special containers. For a variety of advantages, velocity-layer devices (VLD) are chosen as a target of research. In the known development of these devices there are some questions on the fundamental solutions; besides, the effectiveness of factors for the oxygen enrichment of water is not determined. The logical analysis of the existing data on the processes taking place in the VLD, analytical methods of problem-solution, screening studies on the impact of some factors by applying a known control equipment, and statistical data processing, are used as research techniques. As a result of the work performed, the most significant factors operating in the velocity-layer devices are identified. The searching and screening experiments have shown that the cavitation and occurrence of free air in the treatment chamber have the greatest impact on the oxygen enrichment of water and the water disinfection for aquaculture. Besides, to reduce energy losses, the gaps between the magnetic conductors should be reduced as much as possible. The results of these experiments allow offering the design that provides the prevalence of the mentioned factors in the treatment of the wastewater for aquaculture.

The work objective is to create a new seeder designed to work in heavy soils. The main purpose of the modified design is the elimination of difficulties occurring at seeding, especially when there are crop remains in the soil, and former cultivated crop residues on its surface. Experiments were carried out under the following variable factors: seeder speed, operating depth, tillage tool design, seed slot height and distance between seed slots, angle of dropping grain, distance between tool hulls, and distance between the sowing slot and the tine. The research results suggest that the application of the modified seed drill allows improving the uniformity of the grain distribution in the soil. In this case, the yield is increased by almost 14% and reaches the level of 86.7%. The optimal parameters of the modified design include the following: the distance between the tillage tool body and the slot seed opening is 50 cm; the angle of dropping the seed material from the slots on the soil is 60⁰; the height of the grain fall from the slots is 50 cm; the distance between the slot seed openings is 17 cm; the seeder speed is 8 km/h. It is found that tillage tools fitted with rigid props with vane shovels make the greatest effect.

The work objectives are the simulation of the water distribution in the symmetric multilevel capillary systems with curvilinear capillaries, and the calculation of water rise in the curvilinear capillaries by the angle of inclination to the horizontal tangent to the water meniscus in the capillary. For a complete description of the water advance in the curvilinear branches of different levels, the coordinates of the water menisci in those levels about the axes y and x related respectively to the vertical capillary axis and the water surface are determined. Ceteris paribus, the value of water movement in the curvilinear capillaries is always greater than in the straight ones. The results obtained are useful in studying the conductivity of xylem vessels and the promotion of soil moisture in the plant structures which is directly related to the rising and distribution of water in the xylem. It is shown that with increase of the number of levels, the tangent angle to the water menisci in the curvilinear branches is reduced in comparison with the first curvilinear branch. The reduction of this angle indicates that the water in the curvilinear branches is moving the less, the higher the level number is.

The aim of this work is to find the methods of reducing noise and vibration in the belt drive of the electromechanical drive of the selected technological equipment. Thus, we are having more comfortable working conditions in the workplace in compliance with the sanitary standards of noise and vibration. The noise abatement techniques and the simulation of the vibration of the grinding woodworker flexible gearing are considered. Modeling was performed with the introduction of Euler variables. The simulated dependences allow by calculation determine noise levels and load characteristics of the selected equipment. The comparison between the expected noise levels and the sanitary standards allow determining the exceedance and the sources of its generation. All this is the basis for selecting the engineering solutions to observe the noise code.

The work objective is to estimate the electromagnetic environment on the roof where a mobile system base station aerial is installed. The problem arises during maintenance, repair, and assembly operations for antenna-feeder devices. The evaluation problem for ecological assessment of the electromagnetic environment at a standard height of two meters above the roof is solved with the computational prediction method. Two strict models are used for electrodynamic simulation of energy flux density, i.e. a two ray model which describes the plane electromagnetic wave diffraction on the flat perfectly conducting roof surface, and finite models of the roof are described with the canonical problem on a wedge of infinite extent. The difference between the developed model and the known ones lies within the research possibility not only in the computational points but within a whole computational plane. In the simulation process, antenna emission characteristics can be set in a number of ways including those obtained from the radiation object specifications, as it is proposed in a well-known technique. The simulation results for energy flux density distribution in a horizontal plane within the roof space are given. Computational points are placed at the square grid nodes with the period of a quarter wavelength of the transmitter. A physical interpretation of the obtained results is given. A safety conclusion on the human presence on the roof with operating directional cel lular antenna of GSM standard is formulated.