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Provision of machining accuracy is a relevant objective in technology of mechanical engineering and its solution allows to guarantee an operational accuracy of mechanisms and machines, their wear resistance, reliability and durability. In order to solve the given task a method has been proposed in the paper that permits to ensure the highest machining accuracy margin on the basis of multiple-factor optimization of parameters for technological process while using methods of artificial intelligence. To ensure the machining accuracy by point tools, an intellectual system has been developed and it is based on technologies of functional semantic networks. For revealing correctness of SEMANTIC intellectual system operation an experimental inspection of its working capacity has been carried out in the paper. The paper contains description of the methodology for In article the technique of experimental investigations and their purpose is to make a comparative analysis of actual errors in opening machining with the machining errors predicted by the SEMANTIC system on the basis of functional semantic network application. The investigations have made it possible to determine dependences of axial misalignment in the machined openings on tool advance and its rotation frequency while making openings by high-speed steel drills. The paper presents analysis results of limiting and probable values for components of a total machining error. It has been shown that while making assessment of machining accuracy it is necessary to consider probabilistic nature of occurrence of total error components that are setting upper boundary as it is realized in the described intellectual system. The semantic network permits to compare errors in arrangement of opening axes which are machined in accordance with admissible drill advance and rotation frequency and corresponding experimental values. The experimental investigations prove the possibility to use an approach for forecasting a total machining error which is based on application of functional semantic network technology.

The paper contains substantiated expediency in application of machine tools for manufacturing lenses with low stiffness which make it possible to process simultaneously both actuating surfaces of optical parts. While doing so there is a possibility not only to improve quality of parts due to exclusion of their deformation at the blocking stage but there is also a possibility to ensure significant increase in productivity of the process which pre-supposes shape-formation of high-precision non-process optical elements and also to decrease energy consumption per unit of production. A basic diagram of the machine tool for simultaneous processing of two-sided optical parts with spherical surfaces under conditions of free lapping is presented in the paper. The paper describes the essence of the free lapping method which is one of the most widely used methods in optical instrument-making while obtaining parts with precision actuating surfaces. Methodology for determination of technological equipment settings that ensure uniform stock removal along the whole surface to be machined and also its forced removal as in the central zone of a work-piece, so along its periphery and it is necessary in order to correct macro defects in the form of “hump” or “hole”. The paper proposes methodology for determination of sensitivity in stock removal intensity in respect of changes pertaining to machine tool settings and efficiency of these settings while making corrections of lens macro defects. It has been revealed that maximum sensitivity in stock removal occurs in the case when we change a tool diameter. As for efficiency of the technological equipment settings it has been established that in order to rectify macro defects in the form “hump” or “pit” it is more expedient to change rotation ratio of the tool and the part. Experimental tests on lens processing have been executed and they adequately correlate with the results of theoretical investigations.

Quality of surface cleaning against corrosion influences on efficiency in realization of a number of technological processes. While using bentonite clays in power fluid reverse-blast cleaning ensures formation of anticorrosion protective coating with light absorbing properties on the cleaned surface and prevents formation of the repeated corrosion. The paper presents results of the investigations pertaining to influence of reverse-blast cleaning parameters of steel sheets on quality of the cleaned surface prior to laser cutting. Processing conditions, applied compositions of power fluid and also properties of the protective film coatings on the cleaned surface have been given in the paper. The paper considers topography, morphology and chemical composition of the given coating while applying complex metal micrographic, X-ray diffraction and electronic and microscopic investigations. A complex of laser cutting (refer to gas lasers) with output continuous capacity of 2.5/4.0 kW has been applied for experimental works to evaluate influence of the formed surface quality on efficiency of laser cutting process. Specimens having dimension 120×120 mm, made of steel Ст3пс, with thickness from 3 to 10 mm have been prepared for the experiments. An analysis has shown that the application of reverse-blast cleaning ensures higher speed in laser cutting by a mean of 10–20 %. The investigations have made it possible to determine optimum cleaning modes: distance from a nozzle to the surface to be cleaned, jet velocity, pressure. It has been revealed that after drying of the specimens processed by power fluid based on water with concentrations of bentonite clay and calcined soda a protective film coating with thickness of some 5–7 µm has been formed on the whole cleaned specimen surfaces. Chemical base of the coating has been formed by the elements which are included in the composition of bentonite clay being the basic component of the power fluid.

Computational researches the effect of composition of fuel containing butanol on working process parameters of 4ЧН 11/12,5 diesel engine on the external speed characteristic have been conducted. Nominal power is 140 kW at engine speed 2300 min–1. The engine is equipped with gas turbine pressure charging with intercooling of charging air, accumulator-type fuel-handling system. Calculations of the working process have been made in accordance with the developed computer program and models. Investigations have been carried out in two stages: without any changes in regulation of fuel-handling system and with cyclic fuel delivery that ensure such value of excess air factor at various operational modes which corresponds to the operation with diesel fuel. All the obtained results have been analyzed in the paper. The paper shows changes in mean indicated pressure, specific indicated fuel consumption, indicated efficiency, specific nitrogen oxides emissions for various modes in question while using 5, 10, 15, 20, 25 and 30 % mixture of diesel fuel with butanol. Dependences of parameters pertaining to diesel operation have been determined according to external speed characteristic for various mixtures and the obtained data make it possible to justify parameters of the fuel-handling system. It has been recommended to use a diesel fuel-butanol mixture containing 15 % of butanol without any changes in regulating and design engine parameters. It has been revealed that in order to improve parameters of the engine operational process mixture composition must be changed while changing the operational mode. An injector nozzle with a compound needle for the fuel-handling system has been developed and it allows to change fuel composition according to engine operational mode.

A simplified method for calculation of standard coefficient for heat transfer in a residential building has been developed in the paper. Investigations have been carried out with the purpose to determine influence of building size, level of thermal insulation in external enclosures and share of heat regeneration in ventilation system on total heat losses. The paper considers buildings of a simple geometrical form (“matchbox”) with number of floors 1, 2, 4, 8, 16 and living area from 100 up to 25600 m2 at the level of thermal resistance of walls 1; 3 and 5 m2 ⋅°C/W and share of heat regeneration in ventilation air stream of 0; 0.5 and 0.66. The investigation results have shown that while increasing building size then there is a sudden transformation of dimensions and structure in external enclosures: share of overlapping area is reduced by 3-fold and share of wall area is increased by 2-fold. Surface area of building external envelope is reduced by 6-fold in comparison with its heated area. An average coefficient of building heat transfer assigned to heated area is decreased by 3-fold. It has been shown that the most efficient methods for further decrease of standard heat losses for residential buildings are the following: heat recovery in the ventilation system: it is deeper if heat protection rate is higher and climate of a building construction zone is colder; enlargement of building size through decrease of their number; limit-exceeding increase in heat protection of small apartment buildings and cottages; cubic form of 2–3-floor buildings for Far North.

The paper reports on peculiar features pertaining to execution of construction works during reconstruction of buildings. Practical experience on replacement of load-bearing structures has been analyzed for illustrative purposes. Attention has been concentrated on peculiarities in respect of organizational and technological solutions resulting from installation of temporary reinforcement structures. This is due to the fact that it is necessary to ensure spatial rigidity and stability of adjacent and existing construction structures of the building. In other words, when certain construction structures are replaced for some period of time the adjacent structures are without any support that ensure position stability for individual structural elements and building as a whole. Such a situation may lead to deformation of structures or their failure. In this regard, works must be performed in accordance with work zones that ensure stability in the adjacent structures. The paper presents examples of practical solutions concerning replacement of load-bearing floor structures and outer portion of a bearing wall in one of the buildings under constraint conditions. In this context when replacing intermediate floor works have been carried to strengthen temporarily reinforced concrete columns. Spacer steel beams providing column stability from plane have been used for this purpose. While making partial dismantling of the wall a variant presupposing installation of temporary vertical bearing structure in the form of a portal has been used in the paper. The given structure has been bearing loads from floor slab up to completion of re-bricking of bearing wall portion and arrangement of other structures in accordance with design solutions. The presented organizational and technological solutions will be useful for builders and designers while making development of design and technological documentation for reconstruction of buildings.

Nowadays we observe rather rapid growth of energy accumulators market. There are prerequisites to their extensive application in Belarus. In spite of technology development problems pertaining to optimization of electric power and their operation under conditions of specific systems “generator – accumulator – consumer” (GAC) have not obtained proper consideration. At the same time tuning and optimization of the GAC system may provide competitive advantages to various accumulating systems because application of accumulator batteries in non-optimal charge – discharge conditions reduces its operating resource. Optimization of the GAC system may include utilization of hybrid accumulator systems together with heterogeneous chemical and mechanical accumulators, tuning of system controller parameters etc. Research papers present a great number of empirical and analytical methods for calculation of electric loads. These methods use the following parameters as initial data: time-averaged values of actual electric power consumption, averaged apartment electric loads, empirical and statistical form coefficients, coefficients of maximum electric load for a group of uniform consumers. However such models do not meet the requirements of detailed simulation of relatively small system operation when the simulation must correspond to non-stationary, non-averaged, stochastic load nature. The paper provides a simple approach to the detailed simulation of electric loads in regard to small projects such as multi-unit apartment building or small agricultural farm. The model is formulated both in physical and algorithmic terms that make it possible to be easily realized in any programming environment. The paper presents convergence of integral electric power consumption, which is set by the model, to statistically averaged parameters. Autocorrelation function has been calculated in the paper that shows two scales for autocorrelation of simulated load diagrams. The paper contains of an analysis on Fourier spectra for generated electric load diagrams. The model of electric load may be used separately or as a component of a general model in the GAC system. It may also be applied for tuning of automatic systems for control and accounting of power resources and various research purposes.

The paper considers reasons of internal air parameter mismatch in warm season of the year for public building premises having large area of translucent structures. The main reason of uncomfortable air environment is an underestimated value of air supply volume due to air exchange calculation according to multiplicity factor or air exchange rate per one person which are determinative values only for cold period and transient conditions. In other words multiplicity factor and air exchange rate do not take into account equipment abundance in modern offices and heat input of the office equipment is rather significant value. The paper contains an analysis and comparison of the existing air exchange rates for the Republic of Belarus, Russian Federation, European countries and USA. Calculation of heat input and air exchange for public building premises during warm season of the year for assimilation of evident heat excess has been made at various orientations of curtain walls. The paper provides structure of heat input into premises. The required rate of air supply volume per one person has been determined on the basis of air exchange and it has been compared with the existing air exchange rate. The required rate averagely exceeds the standard one by 12-fold. But this does not mean that there is necessity to increase the rate in such a way because it entails an increase in capital and operational costs. In this connection the paper reviews variants for improvement of micro-climate in the building premises with large area of translucent structures: automatic regulation of heat transfer in heating appliances during cold period of the year; usage of air conditioning and increase in temperature difference of input and output air during warm period.

This paper extends the recently introduced approach for modeling and solving the optimal control problem of fixedswitched mode DC-DC power converter. DCDC converters are a class of electric power circuits that used extensively in regulated DC power supplies, DC motor drives of different types, in Photovoltaic Station energy conversion and other applications due to its advantageous features in terms of size, weight and reliable performance. The main problem in controlling this type converters is in their hybrid nature as the switched circuit topology entails different modes of operation, each of it with its own associated linear continuous-time dynamics.This paper analyses the modeling and controller synthesis of the fixed-frequency buck DC-DC converter, in which the transistor switch is operated by a pulse sequence with constant frequency. In this case the regulation of the DC component of the output voltage is via the duty cycle. The optimization of the control system is based on the formation of the control signal at the output.It is proposed to solve the problem of optimal control of a hybrid system based on the formation of the control signal at the output of the controller, which minimizes a given functional integral quality, which is regarded as a linear quadratic Letov-Kalman functional. Search method of optimal control depends on the type of mathematical model of control object. In this case, we consider a linear deterministic model of the control system, which is common for the majority of hybrid electrical systems. For this formulation of the optimal control problem of search is a problem of analytical design of optimal controller, which has the analytical solution.As an example of the hybrid system is considered a step-down switching DC-DC converter, which is widely used in various electrical systems: as an uninterruptible power supply, battery charger for electric vehicles, the inverter in solar photovoltaic power plants.. A qualitative change in the projected illustration of the control signal, a sequence of control pulses and output management object (inverter).

The paper presents results pertaining to investigations of traffic conditions and intensity of traffic and pedestrian flows, calculations on loading level of objects located in the Makayonka Street, Minsk. The objects constitute transport regional development which presupposes reconstruction of regional arterial street with due account of infrastructure improvement, residential construction and construction of multi-purpose complex with shopping, entertainment, wellness and business centers. In addition to this it is planned to construct a two-level underground parking, a two-level interchange at intersection of the Filimonova Street and Nezavisimosty Avenue due to an increase of traffic load at adjacent neighboring street and road network. An analysis on the current traffic management and calculation for distribution of the existing and prospective traffic load levels after implementation of appropriate measures to improve quality as a whole and road safety as well has been carried out in the paper. Determination of loading levels for a street and road network has been carried out while taking into account an intensity of traffic flows in order to evaluate various options for road traffic organization. Variants for planning of road junctions, road traffic organization and traffic signalization (including coordinated passing of transport facilities) have been developed in the paper. All this will contribute to improvement of quality and road safety in the investigated street with due consideration of further development of the region and overbuilding of the existing housing system in the Makayonka Streets and increase of its transport importance in the Minsk street and road network.

The paper presents results of investigations on the process pertaining to interaction of a driving wheel with ground surface and describes methodology for optimization of backbone parameters. The mentioned process has some specific differences in comparison with the process of wheel rolling along hard surface. Ground surface is represented by mixture of sandy and clay particles with plant residues and it has a number of physical and mechanical properties. The main of these properties is resistance of soil against compression and displacement. Compression process determines a track depth and resistance to motion and displacement process determines wheel gripping property and its tangential traction force. While executing the investigations laws of compression and displacement proposed by Prof.V. V. Katsygin as the most adequate reflection of actual processes have been used in the paper. Motion of the driving wheel along ground surface is accompanied by its slipping. It has been determined that the maximum wheel traction force is formed not with 100% slipping as it was supposed until present but the value has been obtained at 45–60 % slipping according to soil category. The developed integral equations with due account of the aspect make it possible to calculate road hold characteristics of driving wheels of the designed wheel tractor and evaluate its traction, speed and economic characteristics. Methodology has been developed for optimization of backbone parameters of wheeled running gear in the designed tractor such as design mass and adhesion weight, width, diameter and air pressure in a tire. The proposed methodology has been introduced in designing practice of wheeled tractors at OJSC “Minsk Tractor Works”.

Literary analysis has shown that the majority of researchers are using classical efficiency criteria for construction of an optimization model for production process: profit maximization; cost minimization; maximization of commercial product output; minimization of back-log for product demand; minimization of total time consumption due to production change. The paper proposes to use an index of added value as an efficiency criterion because it combines economic and social interests of all main interested subjects of the business activity: national government, property owners, employees, investors. The following types of added value have been considered in the paper: joint-stock, market, monetary, economic, notional (gross), net, real. The paper makes suggestion to use an index of real value added as an efficiency criterion. Such approach permits to bring notional added value in comparable variant because added value can be increased not only due to efficiency improvement of enterprise activity but also due to environmental factors – excess in rate of export price increases over rate of import growth. An analysis of methods for calculation of real value added has been made on a country-by-country basis (extrapolation, simple and double deflation). A method of double deflation has been selected on the basis of the executed analysis and it is counted according to the Laspeyires, Paasche, Fischer indices. A conclusion has been made that the used expressions do not take into account fully economic peculiarities of the Republic of Belarus: they are considered as inappropriate in the case when product cost is differentiated according to marketing outlets; they do not take account of difference in rate of several currencies and such approach is reflected in export price of a released product and import price for raw material, supplies and component parts. Taking this into consideration expressions for calculation of real value added have been specified in the paper.

Most of the load experiencing parts operate in a complex state of stress (СSS). The article describes the device layout diagram for modeling a СSS in a ferromagnetic material and the development of monitoring methods. The principle of operation of the device is based on the joint action at a sample of longitudinal extension and lateral bending. The article describes the methods of creating a СSS and materials research using the method of the Barkhausen effect in static and dynamic loading conditions. The article presents the functioning of the algorithm and device operating principle. The article also shows the diagram for modeling a СSS in a steel sample. In this work, are the construction and operation of the device described in detail. This device differs from simple industrial test equipment by small weight, size and cost. The paper presents experimental examples of the influence of the simple forms of the state of stress (longitudinal stretching or lateral bending) and a CSS on the intensity of the magnetic noise in two samples of structural steel. The study established that the total value of the magnetic noise in complex stress state of the sample caused by the forces of simultaneously stretching and bending load, is approximately equal to the algebraic sum of magnetic noise values for each simple type of stress. The linearity of the intensity of the magnetic noise versus axial tensile stress is observed in a range of 0 to ≈ +300 MPa, flexural tensile stresses – of 0 to ≈ +500 MPa, the total stresses – to ≈ 100–110 MPa. The obtained results confirmed the efficiency and effectiveness of the device. The article shows that the magnetic noise is affected not only by the magnitude of the tensile stress of the axial force or tensile stresses in bending or full stresses, but also by the steel grade, the physical and mechanical properties of the material under test. The sensitivity of the magnetic noise to the combined action of the two types of state of stress was higher than for any separate type. The results may be useful in the evaluation of a CSS in ferromagnetic products and the various elements of steel structures. The paper presents the main technical characteristics of the device (weight 18 kg, dimensions 600 × 200 × 170 mm).

The paper presents results of research for influence of plasma jet parameters (current, spraying distance, plasmasupporting nitrogen gas consumption), fractional composition of an initial powder and cooling degree by compressed air on characteristics of anti-meteorite coatings, subsequent processing modes by pulsed plasma. Properties of the obtained coatings and results of ballistic tests have been given in the paper. The proposed methodology has been based on complex metallographic, X-ray diffraction and electron microscopic investigations of anti-meteorite aluminum oxide coating. Optimization of air plasma spraying parameters for NiAl and Al2O3 materials has been carried out in the paper. The spraying parameters optimization has been executed on the basis of obtaining maximum materials utilization factor. Surface treatment of model screen elements with a double-layer composite coating (adhesive metal NiAl layer and hard ceramic oxide Al2O3 layer) has been fulfilled while using compression plasma stream. Nitrogen has been used as working gas. Composite hard ceramic oxide Al2O3 coating is represented by porous structure consisting of 10–15 µm-size fused Al2O3 particles. Metallic inclusions formed due to erosion of plasmatron electrodes have been observed in the space between the particles. Surface of bilayer composite coatings has been processed by a compression plasma stream and due to nonsteady processes of melting and recrystallization high strength polycrystalline layer has been formed on their surface. In this context, those areas of the polycrystalline layer which had metal inclusions have appeared to be painted in various colors depending on chemical composition of the inclusions.

The paper considers new methodologies pertaining to on-board diagnosis of wear-out rate for friction linings of a clutch driven disk and friction discs of a hydraulic press clutch of transmission gear boxes which are based on physical process that uses friction work as an integrated indicator. A new methodology in determination of life-span rate for engine oil has been developed in the paper. The paper presents block schematic diagrams for on-board monitoring of technical state for power units of wheeled and tracked vehicles. Usage of friction work as an integrated indicator for determination of wear-out rate for friction linings of clutch driven disk and friction discs of a haydraulic press clutch makes it possible timely at any operational period of wheeled and tracked vehicles to determine their residual operation life and forecast their replacement.While taking volume of the used fuel for determination of engine oil life-span rate it permits quickly and effectively at any operational period of wheeled and tracked vehicles to determine residual useful life of the engine oil and also forecast its replacement.

The paper studies regularities and mechanisms of structure and phase formation in the surface layers of magnesium alloys when they are processed by method of micro-arc oxidation [MAO]. It has been determined that the same specific features of structure formation, namely: existence of a thin dense inner sublayer and a thicker outer sublayer with developed porosity are common for all types of coatings on the surface of magnesium and aluminum alloys. Such structural state of a protective coating can not be considered as a guaranteed protection against operational impacts, taking into account the fields of their primary application that is aviation construction, automotive construction, instrumentation, building construction, etc. The paper has analyzed the effect of alkaline electrolytes with varying chemical composition due to additions of sodium fluoride or potassium on the structure and properties of these alloys as well as on the level of basic performance characteristics of the layers formed in such electrolytes. On the basis of the analysis a conclusion has been made that it is possible to extend their life-span under operational conditions. It has been revealed that the existing techniques and methods for process control of MAO aluminum and magnesium alloys, particularly processing modes and technological equipment capacity determine a nature of structure formation and changes in a phase composition of the formed coatings.

The paper considers a current scientific and technical problem pertaining to creation of multi-bridge wheeled chassis for highly efficient modular sugar beet harvesters of large cargo capacity and, in particular, to selection of main parameters of chassis and wheeled drive. Such machines are designed for operation under complicated soil and climatic conditions during sugar beet harvesting. Methodological rules and regulations have been developed for solution of problems pertaining to scientifically sunstantiated selection of a manufactured or developed wheeled chassis model, building-block parameters of a working device and a chassis, rational control algorithm of the unit running system while using a specified (domestic or foreign) semi-mounted equipment for beet harvesting. While solving the problem theoretical provisions for wheeled vehicles regarding specific features of a wheeled chassis for modular sugar beet harvesters with extensive mechanical or hydrostatic wheel drive of a multi-bridge propulsion system have been developed in the paper. Calculated and theoretical expressions for determination of main parameters for a wheeled chassis have been obtained and they include physical quantities of operational conditions that explicitly determine its working process. Such approach has made it possible to realize the obtained expressions as a software application which is suitable for analysis of main parameters in respect of the investigated harvester chassis and rational parameters of a branch wheel drive and also for a complete set of tires in the case when a sugar beet harvester is designed on the basis of wheeled chassis according to the selected scheme. Investigations have theoretical significance and represent practical interest for development spesialists of new modular multi-bridge sugar beet harvesters.

The paper considers problems pertaining to higher durability and reliability of a cutting tool for cutting gastronomic products while using laser processing that leads to resistance increase of material operating surfaces against impact forces. Influence of laser fusion with additional doping on structure, microhardness, wear resistance for adhesive coatings of Fe–B–Cr–Si system has been studied in the paper. In order to solve a problem for selection of optimal qualitative and subsequently quantitative composition of a multi-component coating a mathematical modeling method using Scheffe’s simplex lattices has been used in the paper. Similar tendency for measuring micro-structure of all adhesive coatings fused by laser beams has been established in the paper. Increase in beam speed has caused the following microstructure changes: cast equilibrium, dendrite, supersaturated boride, carbide and boride. Response surface models have been found and they provide the possibility to assess influence quantity of laser processing parameters on microhardness of adhesive coatings obtained by laser doping and intensity of their wear under various conditions for all investigated compositions.It has been ascertained that there is no strict correlation between hardness and intensity of coating wear after laser doping used for adhesive coatings. This testifies to the fact that hardening has taken place not only due to an increase of carbide-boride phase, but also due to matrix hardening.In addition, a regression model for coating composition effect on tribological characteristics of the adhesive coatings has revealed that an optimal composition of a multicomponent coating ensuring maximum wear resistance of coatings constitutes B4C is 2/3 and 1/3 TaB. It has been determined that hardening of the adhesive coating after laser doping while using multicomponent coating occurs not only due to increase of carbide-boridnoy phase, but also due to matrix hardening.

Electric conductivity of vapor-gas envelope in electro-impulse polishing mode is closely connected with mechanisms of physical and chemical processes occurring on an anode surface and in pre-anode area of electrolyte, metal removing, smoothing-out of surface profile irregularities and technological regimes influencing on productivity and processing accuracy. The paper presents experimentally substantiated conceptual model of a mechanism for electric conductivity of vapor-gas envelope. According to the model an electric current passing in the envelope and having quasi-constant and high-frequency components is provided by ionic conductivity in electrolyte envelope-enclosing bridges and ionic conductivity in gas envelope phase. It has been shown that quasi-constant of the current component represents a composition of electric current consisting of overlapping time current impulses from electrolyte bridges that enclose the envelope with frequency of 0.01−0.90 kHz and current in a gas phase of the envelope. High-frequency current component is pre-conditioned by ionic conductivity in bridges that commutate the envelope with frequency of 2.5 MHz. The paper theoretically substantiates excessive electrical conductivity of electrolyte in the electrolyte bridges. It has been demonstrated that formation of vapor-gas envelope and its renovation are connected with thermal burst mechanism for destruction of electrolyte bridges. Envelope vibration and hydrodynamic flows within the electrolyte occur due to impulse wave impact on electrolyte layer which is on the border of the envelope. The waves are caused by burtsts of electrolyte bridges and cavitation bubble collapse in pre-anode electrolyte area.

The paper contains an analysis of dimple geometric parameters obtained on wire surface during its in its electrical discharge machining. A photography and description of one of the dimples has been given in the paper. The paper has analyzed a cross-sectional shape of the obtained dimple with due account of the solidified metal flows formed along its edges. The flows in a first approximation can be considered as elements of a cutting wedge. According to cutting theory provisions the paper considers solidified metal flow shapes in a longitudinal section and indicates angles which have been formed by the flows, working planes and edges which can be involved in the cutting process. It has been shown that cutting elements on the dimple surface are arranged symmetrically that makes it possible to carry out cutting process while moving a tool in both directions of reciprocating motion. Parameters of cutting surface influencing on cutting process execution have been specified in the paper. It has been demonstrated that due to changes in energy of electric discharge through voltage or capacity of a power supply storage capacitor it is possible purposefully to influence on the shape and size of metal flows and, respectively, on values of cutting wedge parameters that characterize a tool cutting ability. A conclusion has been made about possibility to obtain the most advantageous values of these parameters while optimizing modes of wire electrical discharge machining.

Performance tuning improvement of modern diesel engines exerts an influence on technical and economic, ecological and resource indices of an internal combustion engine (ICE). In its turn, that requires a complex estimation and improvement of engine indices. As is known, working process and thermal intensity of combustion chamber parts are interconnected between themselves. Changes in design, operating and adjustment parameters of systems and structural elements of internal combustion engines that enable air-fuel mixing and combustions processes stressed state of combustion chamber parts. Joint estimation of operating cycle parameters and strength indices of ICE parts makes it possible to solve a number of problems originating in the process of designing new engine models and further development of the existing ones. The paper provides results of comparative estimation on heat-stressed state of a cylinder head for a high-speed diesel engine Д21A (2Ч10,5/12) while operating a rated power mode. In order to simulate and specify a heat-stressed state for description of boundary heat conductivity conditions the following adjoint “gas – wall” problems have been solved: the first one – for combustion chamber of a diesel engine (an internal problem) – simulation of a working cycle for a diesel engine; the second one – for cooling edges while blowing over them by air flow (an external problem). Calculations have been made in three-dimensional non-stationary presentation within the Cartesian coordinates. In order to simulate a working cycle of the diesel engine a computational grid describing combustion chamber configuration, inlet and outlet channels has been used in the paper. Solution of the external problem for cooling edge surface in case of blowing over them by air flow has permitted to specify temperatures and heat-transfer coefficient and later to improve an accuracy while estimating level of temperatures and stresses of the cylinder head.

Pollution of an atmosphere due to hazardous substances emissions deteriorates ecological environment in the world. Exhaust gases of diesel engines are considered as one of the main environmental pollutants. At the moment it is not possible to determine rate and limits of threshold level of air pollution which do not affect human health. The paper considers current issues pertaining to regulation and control over dispersed particles. The most convenient measuring methods for investigations are those which provide the opportunity to obtain immediate results. However, from the legislative point of view, a gravimetric investigation method is a legitimate one which requires compliance with certain procedures of adjustments and calculations. The method presupposes availability of complicated system for sample dilution and its adjustment must include temperature and kinetic parameters of the measured flow. In order to ensure measuring accuracy and results reproducibility filter loading should be in a regulated range and dilution parameters should be chosen according to not only engine type but also according to its emissions rate. Methods for evaluation of a hot exhaust gas sample is characterized by higher response and the results correlate with indices of combustion efficiency. However, such approach does not account for a number of processes that take place during gas cooling in the environment. Therefore, in this case, measuring results are to be evaluated within certain boundary conditions with respect to the object of investigations. Difficulty in achievement of modern ecologocal standards is substantiated by complicated fractional composition and multiple stage process in formation of hazardous components. The paper presents calculated dependences between particles and smokiness and contains a comparative analysis. Methods for measurement and investigations of dispersed particles have analyzed on the basis of the results obtainesd during engine tests at various values of fuel supply parameters (injection pressure and timing advance angle of fuel injection).

A large class of systems that have found application in various industries and households, electrified transportation facilities and energy sector has been classified as electrical engineering systems. Their characteristic feature is a combination of continuous and discontinuous modes of operation, which is reflected in the appearance of a relatively new term “hybrid systems”. A wide class of hybrid systems is pulsed DC converters operating in a pulse width modulation, which are non-linear systems with variable structure. Using various methods for linearization it is possible to obtain linear mathematical models that rather accurately simulate behavior of such systems. However, the presence in the mathematical models of exponential nonlinearities creates considerable difficulties in the implementation of digital hardware. The solution can be found while using an approximation of exponential functions by polynomials of the first order, that, however, violates the rigor accordance of the analytical model with characteristics of a real object. There are two practical approaches to synthesize algorithms for control of hybrid systems. The first approach is based on the representation of the whole system by a discrete model which is described by difference equations that makes it possible to synthesize discrete algorithms. The second approach is based on description of the system by differential equations. The equations describe synthesis of continuous algorithms and their further implementation in a digital computer included in the control loop system. The paper considers modeling of a hybrid electrical engineering system using differential equations. Neglecting the pulse duration, it has been proposed to describe behavior of vector components in phase coordinates of the hybrid system by stochastic differential equations containing generally non-linear differentiable random functions. A stochastic vector-matrix equation describing dynamics of the processes has been obtained in the paper. The equation contains both continuous and discrete components, which characterize an amplitude signal modulation. An equation for probability density of phase coordinate distribution in the system has been developed on the basis of a mathematical model for a hybrid system.

The paper is devoted to the class construction of the most non-linear Boolean bent-functions of any length N = 2k (k = 2, 4, 6…), on the basis of their spectral representation – Agievich bent squares. These perfect algebraic constructions are used as a basis to build many new cryptographic primitives, such as generators of pseudo-random key sequences, crypto graphic S-boxes, etc. Bent-functions also find their application in the construction of C-codes in the systems with code division multiple access (CDMA) to provide the lowest possible value of Peak-to-Average Power Ratio (PAPR) k = 1, as well as for the construction of error-correcting codes and systems of orthogonal biphasic signals. All the numerous applications of bent-functions relate to the theory of their synthesis. However, regular methods for complete class synthesis of bent-functions of any length N = 2k are currently unknown. The paper proposes a regular synthesis method for the basic Agievich bent squares of any order n, based on a regular operator of dyadic shift. Classification for a complete set of spectral vectors of lengths (l = 8, 16, …) based on a criterion of the maximum absolute value and set of absolute values of spectral components has been carried out in the paper. It has been shown that any spectral vector can be a basis for building bent squares. Results of the synthesis for the Agievich bent squares of order n = 8 have been generalized and it has been revealed that there are only 3 basic bent squares for this order, while the other 5 can be obtained with help the operation of step-cyclic shift. All the basic bent squares of order n = 16 have been synthesized that allows to construct the bent-functions of length N = 256. The obtained basic bent squares can be used either for direct synthesis of bent-functions and their practical application or for further research in order to synthesize new structures of bent squares of orders n = 16, 32, 64, …

The paper proposes to evaluate achievement of main results in operation of intellectual mechatronic systems with digital control by the obtained information effect. In this respect, common information requirements with intellectual components are considered as a basic information factor which influences on the process of mechatronic system designing. Therefore, some parameters have been accentuated and they can help to provide rather complete description of the processes used for obtaining and using systematic information within the volume of the intellectual mechatronic system. Conformity degree of control vector parameters synthesized by the system and identification results of its current states have been selected as an information criterion of the control efficiency. A set of expected probability values for location of each parameter of an control object and a mechatronic system within the required tolerances has been used for formation of possible states. The paper shows that when a complex information description of the system is used then it is expedient to use an expert assessment of selection probability for allowable control vectors which ensure a system transfer to favorable states. This approach has made it possible to pinpoint main information and technical specifications of the intellectual mechatronic system: structural construction (informational and technical compatibility and information matching of its components); control object (uncertainty of its state and information vector, information capacity of the mechatronic system); control actions (their hierarchy and entropic balance of control process, managerial resource of mechatronic system); functioning result (informational effect and control efficiency criterion, probabilistic selection of system states). In accordance with the fulfilled analysis it is possible to note the most effective directions for practical use of the proposed informational approach for creation of the intellectual mechatronic system: comparison of alternative design solutions based on the analysis of calculation assessments on unconditional entropy of the control object and the system; simulation with the aim to accept a final systematic option while constructing digital controlling block of the created system; complex application of experts’ knowledge, most comprehensive introduction of knowledge to the process of mechatronic system designing.

Definition of reliability for dams of slime storage embankment is given on the basis of reliability theory and characteristics of reliability and their analysis are presented in the paper. The paper specifies qualitative indices for earth dams which are subdivided in two groups: applicability factors and structural reliability factors. A short analysis of all possible causes for accident initiation at earth dams has been made and the analysis has permitted to pinpoint eleven main objects for diagnosis for slime storage dams. In order to assess risk degree of accident initiation at JSC “Belaruskali” slime storages all possible causes of emergency cases and their probability of occurrence have been analyzed in the paper. The paper acknowledges the fact that dam malfunction is possible, as a rule, due to violation of operational rules and regulations. Main parameters of slime storage state which are to be controlled regularly in the process of its operation have been noted in the paper. Observation results over slime storages, calculations of dam slope stability for normal operation (a principal calculation case) and operating irregularities in water seals (a special calculation case). As a stability margin factor is close to 1.0 for a special calculation case, an extreme position of depression curve has been determined for all design sections. It has been recommended to carry out a constant control over its position, and in the case when it reaches its peak value it is necessary to undertake appropriate measures in order to reduce its value. Final expert estimations on probability of accident initiation at the investigated slime storage dams of the 4th Mining Administration, JSC “Belaruskali” have been prepared on the basis of the analysis comprising all the required factors. A conclusion has been made about low risk degree of their destruction.

The paper analyzes advantages and disadvantages of composite reinforcement while reinforcing concrete structures. Results of experimental investigations on adhesion strength of fiberglass reinforcement manufactured in the Republic of Belarus with concrete have been given in the paper. The paper contains an analysis pertaining to the influence of concrete contact diameter and length of fiberglass reinforcing bars on strength and deformability of adhesion with concrete. Failure behavior of prototypes and maximum loading that does cause breakage in adhesion of fiberglass reinforcement with the concrete have been controlled in order to study the influence of diameter and length of fiberglass reinforcing bar contact with the concrete on strength and deformability of concrete adhesion for composite reinforcement produced by various manufacturers. Displacement of non-loaded (free) and loaded ends of the reinforcing bars with regard to concrete exposed face on both specimen ends has been also controlled. The experiments have shown that destruction of the prototypes occurred due to initiation of one of the following three reasons: reinforcement sliding in reference to concrete, cleaving of a protective concrete layer or breakage of composite reinforcement. Start-up moments for reinforcing bar slip in relation to the concrete have been determined with the help of two methods. The paper provides proposals for calculation assessment of anchorage in the concrete for fiberglass reinforcement manufactured by the following enterprises and companies “Stroykompozit” (Gomel, Republic of Belarus), Research and Production Company (RPC) “Biznes-Kontinent” (Brest, Republic of Belarus) and Private Eenterprise (PE) “Minplast” (Minsk, Republic of Belarus).

The paper explores conditions and possibilities for innovation activity in the field of architecture of Syrian hotels. A concept of “innovation” applied to architectural activity has been analyzed in the paper. Hitherto there is no unequivocal interpretation of effects due to innovation activity not only in respect of hotel architecture but also in respect of architecture as a whole and it concerns urban planning, climatic and socioeconomic conditions of Syria. Factors determining innovative development represent natural, industrial, scientific and technical, technological and other resources. An effort to avoid outof-date design solutions, requirements in development and growth of economic and social living standards can be considered as a driving force for qualitative development of hotel architecture in the resort areas of Syria. Prior to outbreak hostilities in the country the economic and social living standards have been achieved commonly due to high tourist activity. Naturalclimatic and historical potential of Syria contribute to an increase of tourist flows and quantitative composition of hotels. So the purpose of the paper is to reveal the possibilities for qualitative development of new architecture in respect of resort hotels, as the most required hotels by tourists in Syria. It is an obvious fact that architecture of hotels should not only reflect traditions and culture of the region, but it must be also technically modern in order to satisfy a global principle of sustainable development.

The paper presents results of investigations on influence of domestic complex chemical additive containing structured carbon nanomaterial and characterized by combined (curing acceleration and plasticizing) effect on concrete curing kinetics in non warm-up version of monolithic concreting technology. Standardized and original methods have revealed experimentally regularities in increase of strength for heavy cement concrete under the influence of specific accelerating UKD-1 additive component and the additive itself according to its dosage (within the range of 0.5–2.0 % of cement mass). Growth rate dependences for the concrete with UKD-1 additive on basic technological factors: cement quality, water-cement ratio value, concrete composition and concrete mixture consistency, curing environment temperature and heat-insulating characteristics of shuttering blocks have been evaluated in the paper. Such approach has made it possible to substantiate rational modes and parameters of conditions for concrete curing with the UKD-1 additive in order to ensure strength (under compression) in the 50–100 % range of the required value at the project age of 28 days without energy consumption for acceleration of its curing.

Having a great number of concrete structure classifications it is recommended to specify the following three principal types: microstructure – cement stone structure; mesostructure – structure of cement-sand mortar in concrete; macrostucture – two-component system that consists of mortar and coarse aggregate. Every mentioned-above structure has its own specific features which are related to the conditions of their formation. Thus, microstructure of cement stone can be characterized by such structural components as crystal intergrowth, tobermorite gel, incompletely hydrated cement grains and porous space. The most important technological factors that influence on formation of cement stone microstructure are chemical and mineralogical cement composition, its grinding fineness, water-cement ratio and curing condition. Specific cement stone microstructure is formed due to interrelation of these factors. Cement stone is a capillary-porous body that consists of various solid phases represented predominantly by sub-microcrystals of colloidal dispersion. The sub-microcrystals are able adsorptively, osmotically and structurally to withhold (to bind) some amount of moisture. Protection of road concrete as a capillary-porous body is considered as one of the topical issues. The problem is solved with the help of primary and secondary protection methods. Methods of primary protection are used at the stage of designing, preparation and placing of concrete. Methods of secondary protection are applied at the operational stage of road concrete pavement. The paper considers structures of concrete solid phase and characteristics of its porous space. Causes of pore initiation, their shapes, dimensions and arrangement in the concrete are presented in the paper. The highest hazard for road concrete lies in penetration of aggressive liquid in it and moisture transfer in the cured concrete. Water permeability of concrete characterizes its filtration factor which depends on curing time and conditions and operational conditions as well.

In the paper a method of automatical counting the number of cell nuclei in histological images is studied. This operation is commonly used in the diagnostics of various diseases and morphological analysis of cells. In this connection, the procedure of automatical count the number of cell nuclei is a key step in the systems of medical imaging microscopic analysis of histological preparations. The main aim of our work was to develop an efficient scheme of automatic counting cell nuclei based on advanced image processing methods: directional filtering, adaptive image binarization and mathematical morphology. Unlike prior research, the presented approach does not provide segmentation of cell nuclei in the image, but only requires to detect them and count their number. This avoids complex algorithmic calculations and provides good accuracy of counting cell nuclei.The paper describes a series of experiments conducted to assess the effectiveness of the proposed method using the available online database of medical test histological images. Critical parameters defined algorithms, configurable at each stage of image analysis. For each parameter we have defined value ranges, and then realized a selection of optimal values for every parameter and a mutual combination of them. It is based on generally accepted quantitative measures of precision and recall. The results were compared with the state-of-art investigations in this field and demonstrated an acceptable level of accuracy of the proposed method. The software prototype developed during the study can be regarded as an automatic tool for analysis of cell nuclei. The presented approach can be adapted to various problems of analysis of cell nuclei of various organs.

The contact potential difference probes distinguished by great variety and produced mostly in the laboratory for specific experimental applications. As a rule, they consist of commercially available instrumentation, and have a number of disadvantages: large dimensions, complexity and high cost, small sensitivity, operating speed, noiseproof, etc. The purpose of this paper is to describe the basic approaches to design of the small dimension, complete contact potential difference probes, providing high sensitivity, operating speed, and noise immunity. In this paper the contact potential difference probe, which is a electrometer with dynamic capacitor plate at about 0.1–5 mm2 . These probes are could be used in scanning systems, such as a Scanning Kelvin Probe, as well as for controlling system of manufacturing processes, e.g. under friction. The design of such contact potential difference probes conducted using modern electronic components, unique circuitry and design solutions described in detail at paper. The electromechanical modulator applied for mechanical vibrations of the reference sample. To provide a high amplitude and phase stability the upgraded generator with Wien bridge was used instead traditional oscillation sensor. The preamplifier made on the base of modern operational amplifiers with femtoampere current input. The power of the preamplifier designed with «floating ground». It allows keeping the relation constant potential to the probe components when changing over a wide range the compensation voltage. The phase detector-integrator based on the electronic antiphase switches with the modulation frequency of the contact potential difference and the integrator. Fullwave phase detection would greatly increase the sensitivity of the probe. In addition, the application of the phase detection allows suppressing noise and crosstalk at frequencies different from the modulation frequency. The preamplifier and the reference sample mounted on a flexible printed circuit board and the edge mechanically connected with a vibrator. Modulator, phase detector-integrator, and other electronic components placed on a separate board. This design contributes to reduce the influence of electromagnetic interference and noise as well as removing microphonic effects, etc.

The document categorization problem in the case of a large business document flow is considered. Textual and visual embeddings were employed for classification. Textual embeddings were extracted via OCR Tesseract. The Viola and Jones method was applied to generate visual embeddings. This paper describes the performance optimization technology for the implemented classification algorithm. Servers with Intel CPUs were used for the algorithm execution. For single-threaded implementation, high-level and low-level optimizations were performed. High-level optimization was based on the parametrization of the recognition algorithms and the employment of intermediate data. Low-level optimization was carried out via compiler tools allowing for an extended set of SIMD instructions. The implementation of parallelization with several multithreaded applications on multiple servers was also described. The proposed solution was tested using own test data sets of business documents. The proposed method can be applied in modern information systems to analyze the content of a large flow of digital document images.

The paper considers the application of an algorithm based on a morphological projector for determining structural differences for comparing dermoscopic images. This will allow to identify changes that have occurred in skin lesions over time, for a more accurate diagnosis of their malignancy. The proposed algorithm makes it possible to detect differences in images even if there is a significant difference in the brightness and color levels of the compared images, and also ignores small insignificant details, such as noise, dermatoscope optics marks, hair, etc. A method for correcting the desynchronization of images using the structural similarity index as a similarity metric, and the sinecosine algorithm as an optimization algorithm is proposed. The proposed algorithms were tested on dermatoscopic images and the possibility of their application was demonstrated.

Finding shortest paths in a weighted graph is one of the key problems in computer-science, which has numerous practical applications in multiple domains. This paper analyzes the parallel blocked all-pairs shortest path algorithm at the aim of evaluating the influence of the multi-core system and its hierarchical cache memory on the parameters of algorithm implementation depending on the size of the graph and the size of distance matrix’s block. It proposes a technique of tuning the block-size to the given multi-core system. The technique involves profiling tools in the tuning process and allows the increase of the parallel algorithm throughput. Computational experiments carried out on a rack server equipped with two Intel Xeon E5-2620 v4 processors of 8 cores and 16 hardware threads each have convincingly shown for various graph sizes that the behavior and parameters of the hierarchical cache memory operation don’t depend on the graph size and are determined only by the distance matrix’s block size. To tune the algorithm to the target multi-core system, the preferable block size can be found once for the graph size whose in-memory matrix representation is larger than the size of cache shared among all processor’s cores. Then this blocksize can be reused on graphs of bigger size for efficient solving the all-pairs shortest path problem

The paper contains a theoretical underpinning on creation of ultrasonic vibration concentrators based on annular elastic elements with non-circular (ellipse-like) eccentric shape of internal contour. Shape of internal contour in polar coordinates is described by Fourier series relative to angular coordinate that consists of a constant term and first and second harmonics. An effect of geometric parameters of the concentrator on amplification factor and natural vibration frequencies has been investigated with the help of a finite element method. The paper reveals the possibility to control an amplification factor of annular concentrators while varying eccentricity of internal contour and mean value of cross-section thickness. The amplification factor satisfies a condition K < N, where N is thickness ratio of amplifier input and output sections, and it is decreasing with increase of vibration mode order. The similar condition has been satisfied for conical bar concentrator with the difference that in the case of bar concentrators an amplification is ensured due to variation of diameter and N will represent ratio of diameters. It has been proved that modification of internal contour shape makes it possible to carry out a wide-band tuning of natural frequencies of concentrator vibrations without alteration of its overall dimensions and substantial change of amplification factor, which is important for frequency matching of the concentrator and ultrasonic vibratory system. Advantages of the proposed concentrators include simplicity of design and manufacturing, small overall dimensions, possibility for natural frequency tuning by means of static load variation. The developed concentrators can find their application in ultrasonic devices and instruments for technological and medical purposes.

The paper investigates a stress-strain state in a polycrystalline grain due to presence in its body of a single micro- twin in case of various grain boundary forms. A methodology for calculation of displacement and stress fields for the specified stress-strain state of a polygon-shaped grain has been developed in the paper. Nodal points in a polycrystalline grain that have a maximum stresses contributing to initiation of destruction have been revealed in the paper. The aim of this work has been to study the stress-strain state due to a single micro-twin in the polycrystalline grain and form of grain boundaries. The paper describes polycrystalline grains having a regular polygon shape and containing a single wedge twin in their body. Polycrystalline grain boundaries are presented as walls with complete dislocation. The investigated grains are located far from the surface of twinning material. The developed methodology for calculation of displacement and stresses created by wedge twin is based on the principle of superposition. Calculations on stress tensor components have been carried out for iron (Fe). The presented results of calculations for stress fields have indicated to validity of the used dislocation model. Twin and grain boundaries being stress concentrators are clearly visible on the obtained distributions of stress fields. Maximum normal stresses are observed on the twin boundaries; σxy maximum shear stresses are located at nodal points of the twin; σzy and σxz shear stresses are maximum on the grain boundaries. The conducted investigations have resulted in study of the stress-strain state due to a single wedge-shaped micro-twin in the polycrystalline grain and form of the grain boundaries. Zones of stress concentration in the polycrystalline grain have been identified in the presence of residual mechanical wedge twin. A method for evaluation of the given state has been developed in the paper.

Introduction of new efficient braking systems for energy-packed tractors is of great importance for agricultural production. Foreign tractor manufacturing companies are implementing brake systems and in addition to their main function they fulfil function for holding of the given driving direction. The paper considers achievements in the field of electronic systems for tractor road-holding ability. A diagram on proportion of high-power tractors in total export volume of tractors and machinery manufactured in Belarus in the period of 2007–2010 has been drawn in the paper. The paper also proposes a comparative diagram on tractor speeds of international manufacturers which can serve as indicators of speed and road-holding ability of tractors with special electronic systems and without them. The paper contains an analysis of various braking mechanisms of planetary gears and detailed description of their design. A scheme of a laboratory facility for investigation of planetary gear usage as a breaking mechanism while changing conditions of jamming has been presented in the paper. The paper provides description on graph dependencies of current strength and voltage on as a function of the braking torque which is applied to a planetary gear. Nowadays energy-packed “Belarus”-tractors of Class 5 do not have a separate braking for each of four wheels. Therefore, it is proposed to use planetary gearbox of the rear-axle drive being available in every wheel as the basis of a service brake with the purpose to implement the described design. Using such scheme it is possible to execute an introduction of electronic systems for road-holding ability. A generalized scheme of an electronic system for tractor road-holding ability which can ensure separate breaking of all tractor wheels has been drawn out on the basis of the existing automotive electronic systems.

The paper presents modern approaches to processing of images obtained with the help of industrial equipment. Usage of pixel modification in small neighborhoods, application of uniform image processing while changing brightness level, possibilities for combination of several images, threshold image processing have been described in the paper. While processing a number of images on a metal structure containing micro-cracks and being under strain difference between two such images have been determined in the paper. The metal structure represents a contour specifying the difference in images. An analysis of the contour makes it possible to determine initial direction of crack propagation in the metal. A threshold binarization value has been determined while processing the image having a field of medium intensity which are disappearing in the process of simple binarization and merging with the background due to rather small drop between the edges. In this regard an algorithm of a balanced threshold histogram clipping has been selected and it is based on the following approach: two different histogram fractions are “weighed” and if one of the fractions “outweighs” then last column of the histogram fraction is removed and the procedure is repeated again. When there is rather high threshold value a contour break (disappearance of informative pixels) may occur, and when there is a low threshold value – a noise (non-informative pixels) may appear. The paper shows implementation of an algorithm for location of contact pads on image of semiconductor crystal. Algorithms for morphological processing of production prototype images have been obtained in the paper and these algorithms permit to detect defects on the surface of semiconductors, to carry out filtration, threshold binarization that presupposes application of an algorithm of a balanced threshold histogram clipping. The developed approaches can be used to highlight contours on the surface images of mechanical engineering products and prepare them as production prototype images in accordance with enterprise documentation. Such approach makes it possible to remove noise on radiographs without introduction of additional distortions in the processed image; highlight defects of welded joints on the images.

A technology for formation of thermal barrier coatings (TBC) based on zirconium dioxide has been developed in the paper. The paper investigates structures of phase composition and thermal stability of such developed coatings. Investigation results pertaining to formation of an oxide system ZrO2 – Y2O3, while using plasma spraying and subsequent high-energy processing, which allows to increase resistance of a thermal barrier coating to thermal cycling heat resistance of the coating at temperature of 1100 °C. This leads to longer protection of bottom layer against high-temperature exposure. The methodology is based on complex metallographic, X-ray diffraction and electron microscopy investigations of structural elements in composite plasma coatings of the ZrO2 – Y2O system. Resistance of plasma coatings (Мe – Cr – Al – Y/ZrO2 – Y2O3-type), used as TBC to protect gas turbine engine blades under conditions of frequent thermal cyclings is limited by cleavage of an outer ceramic layer. Structural and electron microprobe investigations have shown that as a result of thermal cycling an outer atmosphere due to porous structure of the ceramic coating layer, migrates to the surface of lower metal coating, causing its oxidation. As a result, the metal-ceramic Al2O3 layer is formed at a metal-ceramic interface and it changes a stress state of the coating that causes a reduction of protective properties. Thus, a high heat resistance of thermal barrier coatings depends on processes occurring at the interface between metal and ceramic coating layers. A laser impact on samples with TBC leads to changes in the structure of the oxide layer of ZrO2 – Y2O3. In this case its initial surface characterized by considerable relief is significantly flattened due to processing and the coating is fractured and it is separated in fragments. As the oxide coating has low thermal conductivity, and the time of laser exposure is about 10–3 sec, a heat flux does not have time to spread to a greater depth. As a result, the coating surface takes the form of solidified melt. The coating obtained from the powder of ZrO2 – 7 % Y2O3 in accordance with the developed technology can withstand heating – cooling cycles by 1.5-fold more than similar coatings being made previously. Thus the proposed method allows to increase the coating resistance to thermal cycling at temperatures of 1100 °C.

Virtual testing of portal machine tool has been carried out with the help of finite elements method (FEM). Static, modal and harmonic analyses have been made for a heavy planer. The paper reveals influence of concrete filler on machine tool dynamic flexibility. A peculiar feature of the simulation is concrete filling of a high-level transverse beam. Such approach oes look a typical one for machine-tool industry. Concrete has been considered as generalized material in two variants. It has been established that concrete application provides approximately 3-fold increase in machine tool rigidity per each coordinate. In this regard it is necessary to arrange closure of rigidity contour by filling all the cavities inside of the portal. Modal FEA makes it possible to determine that concrete increases comparatively weakly (1.3–1.4-fold) frequencies of resonance modes. Frequency of the lowest mode rises only from 30.25 to 42.86 Hz. The following most active whole-machine eigenmodes have been revealed in the paper: “Portal pecking”, “Parallelogram” and “Traverse pecking”. In order to restrain the last mode it is necessary to carry out concrete filling of the traverse, in particular. Frequency-response characteristics and curves of dynamic rigidity for a spindle have been plotted for 0–150 Hz interval while using harmonic FEM. It has been determined that concrete increases dynamic machine tool rigidity by 2.5–3.5-fold. The effect is obtained even in the case when weakly damping concrete (2 %) is used. This is due to distribution of vibrational energy flow along concrete and along cast iron as well. Thus energy density and vibration amplitudes must decrease. The paper shows acceptability for internal reinforcement of high-level machine tool parts (for example, portal traverses) and fillers are applied for this purpose. Traverse weighting is compensated by additional torsional, shear and bending rigidity. The machine tool obtains the possibility for rough intermittent cutting even at resonance frequencies. Complete concrete filling of portal cavities is definitely a positive action for static and dynamic properties of the machine tool.

The paper considers modern approaches to usage of hydrocarbon-containing waste as energy resources and presents description of investigations, statistic materials, analysis results on formation of hydrocarbon-containing waste in the Republic of Belarus. Main problems pertaining to usage of waste as a fuel and technologies for their application have been given in the paper. The paper describes main results of the investigations and a method for efficient application of viscous hydrocarbon-containing waste as an energy-packed component and a binding material while producing a solid fuel. A technological scheme, a prototype industrial unit which are necessary to realize a method for obtaining multi-component solid fuel are represented in the paper. A paper also provides a model of technological process with efficient sequence of technological operations and parameters of optimum component composition. Main factors exerting significant structure-formation influence in creation of structural composition of multi-component solid fuel have been presented in the paper. The paper gives a graphical representation of the principle for selection of mixture particles of various coarseness to form a solid fuel while using a briquetting method and comprising viscous hydrocarbon-containing waste. A dependence of dimensionless concentration g of emissions into atmosphere during burning of two-component solid fuel has been described in the paper. The paper analyzes an influence of the developed methodology for emission calculation of multi-component solid fuels and reveals a possibility to optimize the component composition in accordance with ecological function and individual peculiar features of fuel-burning equipment. Special features concerning storage and transportation, advantages and disadvantages, comparative characteristics, practical applicability of the developed multi-component solid fuel have been considered and presented in the paper. The paper cites practical results pertaining to usage of hydrocarboncontaining waste for the equipment applied for production of multi-component solid fuel. Data on economic expediency for usage of the multi-component solid fuel with high thermo-technical characteristics in the boiler-houses operating on local solid fuel have been analyzed in the paper. The paper shows a perspective evaluation, applicability and practical significance of the solution of the problem on efficient usage of hydrocarbon-containing waste while producing the multi-component solid fuel.

The paper shows how to determine dimensions of stationary horizontal (canopies) and vertical (ribs) shading devices in order to prevent penetration of normal beam solar radiation into the buildings during warm season of the year. While analyzing formulae for insolation rate equations for determination of dimensions of canopies and ribs which are perpendicular and inclined to the plane of intensively irradiated fenestrations orientated to the South, South-East, South-West, East and West have been obtained in the paper. Sloping canopies have the smallest dimensions. What is more, an angle of slope with regard to opening plane must correspond to elevation of sun station at an hour when there is a maximum specific heat flow rate of normal beam solar radiation. The paper considers an influence of canopies and ribs on transmission of diffuse solar radiation which along with normal beam solar radiation serves for creation of natural illumination. As follows from the analysis of formulae it is possible to make a conclusion about an inefficiency of vertical shading elements due to large rib dimensions and decrease in transmission of diffuse solar radiation. Minimum distances from fenestration reveal to the canopy have been determined for various orientations proceeding from the position that the opening must be maximally illuminated by normal beam solar radiation during the cold season of a year in order to reduce heat inputs for building heating. On the basis of dependence analysis we have come to a conclusion that it is appropriate to design stationary shading devices for fenestrations orientated only to the South and they must be sloping canopies. It is necessary to select glazing with a small index of solar factor for openings orientated to other corners of the Earth and reduction of solar radiation heat inputs.

The paper reveals one of possible methods for higher productivity and reliability of building self-propelled pneumopunchers which are intended for making holes in soil while using trenchless method and constructing various engineering communications under car, tram and rail lines, airport runways. A new design of building pneumopuncher with increased productivity due to higher speed for hole formation in soil and its reliability has been presented in the paper. A formula for determination of displacement increment for a new pneumopuncher in comparison with the conventional one has been obtained in the paper. The paper describes a design and operation principal of the building self-propelled pneumopuncher which is equipped with a locking mechanism with the purpose to neutralize action of soil elastic forces and reactive repulsive force. The locking mechanism keeps the pneumopuncher in the hole. The pneumopuncher consists of a body with anvil, movable hammer, a manifold which is set in axial deepening of the hammer, a nut and a locking mechanism. Improvement of operational pneumopuncher reliability is attained due to the fact that the locking mechanism is made in the form of two coaxially positioned inner and outer cups having a common basis. A piston is installed in the middle of the inner cup, a spring is fixed over the piston and a rod with a breaking shoe is positioned at the end. Height of the inner cup is less the outer cup height and there is an annular cavity between them which is connected with a chamber. The chamber is formed by the piston, the inner cup and the manifold. The annular cavity through an opening in the inner cup wall, two sylphons, a channel in the nut end and an opening in the vertical wall of the manifold are connected with a chamber of operating stroke. The sylphons are placed between the outer cup and the nut, between the nut and the manifold. Differential equations for movement of pneumopuncher in soil have been compiled. While solving the equations a formula for determination of increase in displacement of the pneumopuncher with the locking mechanism and without it has been obtained in the paper.

The paper analyzes main reasons that have led to closure of a number of industrial enterprises on the territory of the Republic of Belarus and in the majority of former Soviet Union countries. An analysis of constructive decisions and range of bearing and enclosing structures for non-operational industrial buildings and facilities has been carried out in the paper. The analysis has made it possible to draw a conclusion that the overwhelming majority of the buildings and facilities were constructed using prefabricated and cast-in-situ reinforced concrete structures. Taking into account the facts that substantially all non-operational industrial buildings and facilities are located in industrial zones being rather far from residential housing area and having developed infrastructure (highways, railway lines, communication network etc.) and expenses on infrastructure development usually exceed the cost of newly built industrial buildings and facilities some findings have been given on expediency pertaining to usage of existing industrial zones. The main problem has been defined in the paper and its solution will permit to use again existing industrial zones with non-operational industrial facilities which are located there. With due account for the executed analysis of standard operating procedures on liquidation of industrial buildings an expediency has been revealed that presupposes demolition of facilities with the help of mechanical breakdown. An economic efficiency on application of mechanical demolition method for industrial buildings constructed using prefabricated and cast-in-situ structures has been illustrated in Work Execution Plan on liquidation of industrial buildings in the workshop which has been involved in lime production at JSC “Berezovsky Industrial Complex of Silicate Products”. The proposed technology for mechanical demolition of reinforced concrete structures is based on application of a caterpillar excavating machine of Doosan S340LC-VSDM model. Its application permits to ensure complete safety conditions while executing works.

It is necessary to mention specially so-called thermal shock among various impacts on highway surface. Ice layer is formed on a concrete surface during the winter period of pavement surfacing operation. Sodium chloride which lowers temperature of water-ice transition temperature and causes ice thawing at negative temperature is usually used to remove ice from the pavement surface. Consequently, temperature in the concrete laying immediately under a thawing ice layer is coming down with a run that leads to significant stresses. Such phenomenon is known as a thermal shock with a meaning of local significant change in temperature. This process is under investigation, it has practical importance for an estimation of strength and longevity of a cement-concrete pavement surfacing and consequently it is considered as rather topical issue. The purpose of investigations is to develop a mathematical model and determination of shock blow permissible gradients for a cementconcrete road covering. Finite difference method has been used in order to determine stressed and deformed condition of the cement-concrete pavement surfacing of highways. A computer program has been compiled and it permits to carry out calculation of a road covering at various laws of temperature distribution in its depth. Regularities in distribution of deformation and stresses in the cement-concrete pavement surfacing of highways at thermal shock have been obtained in the paper. A permissible parameter of temperature distribution in pavement surfacing thickness has been determined in the paper. A strength criterion based on the process of micro-crack formation and development in concrete has been used for making calculations. It has been established that the thermal shock causes significant temperature gradients on the cement-concrete surfacing that lead to rather large normal stresses in the concrete surface layer. The possibility of micro-crack formation in a road covering is determined with the help of such characteristics as material strength, conditions of plate anchoring and a temperature gradient.

Regulation of a river flow makes it possible to meet contradictive requirements of various participants of water resources systems. In recent years the main participants of water resources systems pay a lot of attention to flood prevention in Vietnam and water floods are rather typical for river basins in the South-West of Belarus. Due to such circumstances it looks rather reasonable to create water storage reservoirs. However, degree of flow regulation that is value of the reservoir useful capacity must have a techno-economic justification with due account of river basin specific features. The paper considers particularities of small rivers in pre-mountainous regions of Vietnam. It is expected that the main water use occurs during irrigation processes. For this reason the requirements of other water resources systems participants (especially requirements on flood protection) have come into account in a minimum way. The paper proposes a criterion for optimization of water resources systems parameters and in this case the main participants are irrigation and flood prevention. The criterion reflects minimum regulated volume of river flow per unit of irrigated area while observing restrictions pertaining to flood control, water supply, pond fish farms, water power engineering and environmental protection. Application of mathematical models on the basis of economic criteria for optimization of the water resources systems parameters is possible rather rare due to absence, shortage or poor accuracy in initial data.

The paper considers an application of entropy characteristics as criteria to coordinate traffic conditions at neighboring road sections. It has been proved that the entropy characteristics are widely used in the methods that take into account information influence of the environment on drivers and in the mechanisms that create such traffic conditions which ensure preservation of the optimal level of driver’s emotional tension during the drive. Solution of such problem is considered in the aspect of coordination of traffic conditions at neighboring road sections that, in its turn, is directed on exclusion of any driver’s transitional processes. Methodology for coordination of traffic conditions at neighboring road sections is based on the E. V. Gavrilov’s concept on coordination of some parameters of road sections which can be expressed in the entropy characteristics. The paper proposes to execute selection of coordination criteria according to accident rates because while moving along neighboring road sections traffic conditions change drastically that can result in creation of an accident situation. Relative organization of a driver’s perception field and driver’s interaction with the traffic environment has been selected as entropy characteristics. Therefore, the given characteristics are made conditional to the road accidents rate. The investigation results have revealed a strong correlation between the relative organization of the driver’s perception field and the relative organization of the driver’s interaction with the traffic environment and the accident rate. Results of the executed experiment have proved an influence of the accident rate on the investigated entropy characteristics.

Semi-natural tests for active pneumatic suspension of a 18-tonne tourist bus with the system of automatic body stabilization of the mobile machine and feed-back coupling according to kinematics parameter. The test have been executed in the cases when the bus is stocked with an automatic hydro-mechanical transmission in the process of speed picking up, gear-changing or road braking which is assigned by accidental road humps. A computer simulation of dynamic structures in combination with virtual devices and real objects (HIL – Hardware-in-the-Loop Simulation) has been carried in the paper. Personal computers, software, programmed logic controller, frequency generator, solenoid-operated valve have been used for the investigation process. The paper proposes an unconventional method for improvement operational characteristics which is based on integrated control of a suspension and automatic hydro-mechanical transmission. A mathematical model includes systems of automatic transmission, suspension and module for generation of accidental road humps. The model has been considered as a basis for semi-natural laboratory bench with industrially-manufactured controller, other components of automatic systems and standard control organs. The most efficient method for body stabilization is control of the suspension according to the parameter of angular rate during vertical turn of an automobile’s center line with a turning point in the center of mass. The developed algorithm and stabilization system according to angular rate of body’s center line turning have made it possible to improve dynamics of the bus while making gear-changing and to reduce fuel consumption during starting-up and speed picking-up processes. During the braking process such system simultaneously decreases oscillation amplitude of some parameters more than two-fold.