Search

I. Тhematic index II. Name index

Тhematic Index.

A method has been developed to improve paper qualitative characteristics which is used for manufacturing of packaging. It has been determined that while adding sulfate cellulose obtained from low-grade short flax in paper composition qualitative characteristics of the final product have been improved.

The paper considers problems pertaining to methodology and structure for dissertation preparation. All the problems have been solved on the basis of the analysis of questionnaire complexes. The paper presents concrete examples taken from the dissertations that have passed expertise of the Highest Certifying Commission.

The paper investigates an influence of component quantity (lignin, cellulose and hemicellulose) on qualitative (physical and mechanical) indices of waste-paper in relation to its storage period and weather conditions. It has been established that while storing (in waste dumps) waste paper it is to be kept at a definite temperature and humidity in order to reduce impact of weather conditions.

Hydraulic investigations of the Dneeper water intake for Newsprint Paper Mill in Shklov under various water levels and discharge in the river have been carried out. Regimes of bed alluvium and sludge motions have been studied. The recommendations on intake channel scheme and its main dimensions are given.

The assessment of the suitability of cables of 6–110 kW with XLPE insulation in comparison with cables of the same voltage but possessing paper-oil insulation has been fulfilled on the basis of the method of multi-objective optimization that makes it possible to account not only the quantitative characteristics (of reduced costs), but also qualitative ones. As an indicator of the reliability of the cable line the maximum mean time to failure (the value inversely proportional to the parameter of succession of failures), which is an order more for cable lines with XLPE insulation than for cable lines with paper insulation, is adopted. A comprehensive assessment of the convenience of installation of cable lines revealed that the installation of cable with XLPE insulation features a 1.2–1.6 times easier installation as compared to three-wire (voltage 10 kW) and 1.4 times easier installation as compared to single-core oil-filled cables (voltage of 110 kW). The efficacy of the cables 6–110 kW with XLPE insulation is proved on the basis on the method of multi-objective optimization, that took into account as the costs for the construction and operation of cable lines and the reliability of its operation, ease of its installation and other quality indicators. If the goals taken into account are considered as equally important, the polyethylene-insulated cables for a voltage of 10–110 kW is more efficient as compared to three-wire (voltage 10 kW) and solid (110 kW) cables with paper insulation. Herewith, the cost of the cable with XLPE insulation may exceed the cost of cable with paper insulation up to two times. If the most important aim is to provide the minimum reduced costs for the construction and operation of the cable line, the use of cables with XLPE insulation for voltage of 10 kW is most advisable in individual cases.

The assessment of the suitability of cables of 6–110 kV with XLPE insulation in comparison with cables of the same voltage but possessing paper-oil insulation has been fulfilled on the basis of the criterion of reduced costs. Thus, the comparison was undertaken between cables of various design and material of insulation: three-core paper insulated ones vs. three-core XLPE insulated ones; three-core paper-insulated ones vs. solid wires with XLPE insulation; single-core oil-filled cables of 110 kV with paper insulation vs. solid wires of 110 kV with XLPE insulation. The increase in long-term permissible current loads for cables with XLPE insulation because of the larger permissible temperature of heating in comparison with cables with paper-oil insulation complies with as would increase in the cross-sectional area of cable cores (equal to 0.61 from the original) and therefore reduces the cost of the cable by reducing the cost of manufacture of conductors. The reduced costs of the construction and operation of cable lines with XLPE insulation (accounting the increase in the cost of a cable 1.2 and 2 times as compared with the cost of a cable with three-core insulation), despite the decline in the cost of manufacture of conductors and the reduced annual operating costs (9 % and 17 % respectively of cable lines of voltage of up to 35 kV and 110 kV), occurred to be more than the reduced costs of the construction and operation of cable lines with paper insulation. Currently the cost of one meter of cable with XLPE insulation is less than the cost of cables of AAB, CASB, AASv types of a voltage of 10 kV with aluminium cores, that ensures their undeniable efficacy.

The paper considers some informational resources of the BNTU Scientific Library.

The paper is devoted to the development of methodological foundations for the application of virtual reality technologies (VR-technologies) at various stages of car design and their promotion on the market, in particular, when performing design, prototyping, development of educational and advertising products. The paper analyzes the main areas of application of virtual reality technologies in industrial design in mechanical engineering. An overview of the parameters of the specialized software Unreal Engine 4 and the HTC Vive hardware set used to create and demonstrate virtual projects is performed. System requirements for computer software and hardware for creating virtual projects have been formed. A generalization of our own experience of using virtual reality technologies in the design of an electric vehicle with a frame-panel structure is carried out. The technique of using virtual reality tools in order to create virtual projects for demonstration of design solutions and functionality of mechanical engineering products is described. The issues of choosing software and hardware, their characteristics are considered, as well as a description of the stages of creating a virtual project is given. The process of developing a virtual project is divided into the stages of preparing and transforming a three-dimensional computer model of the demonstrated product into its virtual digital prototype, creating a virtual environment for it, assigning materials and textures with the necessary properties to the environment and the object, setting lighting, navigation parameters and animated actions, optimizing the display of shadows and finalizing the project. The main results of approbation of the developed methodology are presented on the example of creating virtual projects for demonstrating an electric vehicle: in an urban virtual environment and in a virtual pavilion.

Results of a study of an actual scientific and technical problem of determining the road safety level on road sections are presented in the paper. The aim of the study is to develop an express method for assessing road safety based on improving the method of the final accident rate by reducing the partial accident rate with the required accuracy of determining the safety level on public roads. The formalization of the relationship between the parameters of road traffic conditions has been carried out to study the level of safety on highways. Latent factors of the parameters of traffic conditions have been obtained on the basis of reduction of their aggregate by the method of principal components, taking into account the relationship of partial accident rates. This condition has allowed to develop analytical models for determining road safety for implementation in the practice of conducting a road safety audit. A method for identifying hazardous areas on highways has been proposed in the paper. It includes 11 parameters of road conditions out of 18 partial accident rates proposed in the prototype and regulatory documents of Ukraine. The adequacy of the model is determined by deviation values of the obtained data according to the prototype model from the values of the relative accident rate, which were 3.22 and 18.61, respectively. The proposed model reduces the deviation value by six times and affects the accuracy of determining the safety level. Experimental studies have been conducted on 79 km of highways (on 385 sectors with constant values of traffic conditions parameters). The results of a comparative analysis of the safety level for the prototype model and the developed model have been identical and shown a decrease in time and labor costs by 1.6 times without loss of accuracy. Thus, the developed methodology is recommended to be applied for determining the potential danger of road sections during an express analysis of the road safety or when conducting a safety audit at various stages of the road life cycle.

Contact problems for elastic stripes have been well studied and published in domestic scientific literature. This is partly due to the fact that normative documents on the foundation structure it is recommended to use this elastic foundation model for simulation of a “structure – foundation – soil foundation” system. Two variants of boundary conditions at the contact between a half-strip and a rigid non-deformable base are usually considered. The first boundary condition nullifies the vertical displacements and tangential stresses, the second one nullifies vertical and horizontal displacements. Contact problems for an elastic half-strip are much less investigated. The paper considers this contact problem when the first boundary condition for zeroing of vertical displacements and tangential stresses at the contact of a half-strip with a rigid, nondeformable base. When performing calculations in the traditional formulation without taking into account tangential stresses in the contact zone, the Zhemochkin method has been used, which reduces the solution of the contact problem of solid mechanics to the solution of a statically indeterminate problem by the mixed method of structural mechanics. Therefore, at first, we have found the displacements of the upper edge of the half-strip from the unit load uniformly distributed over the edge section. The resulting expression is used to compose a system of equations for the Zhemochkin method. The case of translational displacement of the die has been considered, and the graph of contact stress distribution under the die's sole has been given in the paper.

The paper presents studies on the optimization of the process of applying coatings from cermet powders with different solid phase contents by plasma spraying in air to restore and harden parts of machines and mechanisms operating under adverse conditions. Such conditions are usually created in heavily loaded tribojoints when the mechanisms operate at a low speed of relative movement of surfaces during friction. At the same time, the destruction of the working surfaces is mainly due to the process of microcontact setting and subsequent detachment of the formed particles at their contact points. The application of special protective coatings with the required properties is possible with the manufacture of high-quality starting powder materials and optimization of the technology for their application. Such powders and powder compositions can be obtained by the method of agglomeration of a fine powder mixture with its subsequent high-temperature sintering. To identify the hardening mechanism of composite coatings made of cermet by gas-thermal spraying, important stages are the optimization of the deposition process parameters and the study of the properties of plasma coatings obtained in this case. When optimizing the technological parameters of plasma spraying of coatings, the utilization rate of the sprayed powder material has been taken into account as the main indicator of the process efficiency, the structure of the obtained layers, and the morphology of individual particles deposited on the polished surface. The paper provides data on the structural elements of sprayed materials for wear-resistant coatings obtained by plasma spraying at optimal conditions. Taking into account the processes that occur during the wear of tribological conjugations, the data indicate the existing prerequisites for the wear resistance of the studied composite coatings made of metal ceramics. Special wear-resistant coatings made of materials with a soft matrix hardened by solid inclusions Al2O3–TiO2–Ni–Cr–Al–Y are widely used in various industries. Based on the detailed analysis of the features of cermet plasma coatings, it can be stated that such powder compositions (complex oxides-metal component) are often used as wear-resistant plasma coatings. The research results can be taken into account in cases of application of wear-resistant plasma coatings made of metal-ceramics and compositions based on them, containing solid phases in the form of oxides, as well as the manufacture of a whole range of parts operating under conditions of intense wear.

The paper presents a comparative theoretical analysis of the movements of the curved rods of various curvature forms, which can be applied as tools for ultrasonic treatment of holes in fragile materials. It has been shown that the traditional processing of holes by an ultrasonic method is based on the use of straight rods, in which the amplitudes of displacements on the working – free end corresponds to the value of displacements at the point of its attachment to the ultrasonic oscillation concentrator. Supplementing the configuration of a straight rod with a curvilinear shape in the form of a circular arc or a spiral twisted by one turn will allow obtaining additional displacements caused by the elastic properties of a section with a curved shape. The paper considers several calculated schemes of a curvilinear rod bounded by angles j equal to p/2, p and 2p, fferent direction of the external force action. The obtained results have shown that an increase in the circular arc angle leads to a corresponding increase in the elastic displacement index of the rod free end. In this case, the total displacements of the rod free end will be made from displacements caused by vibrations of the acoustic system and the displacements of a curved thin rod from an external force. Calculations have established that the magnitude of the elastic displacements of curved rods is influenced by the shape and magnitude of the angle, the direction of the external force, the radius of curvature, the rigidity of the cross section. The considered schemes of thin rods with curvilinear sections can find practical application in ultrasonic oscillatory systems for processing small-diameter holes in fragile materials. This increases the intensity of tool oscillations and improves the process performance.

The possibility of using local materials in the construction of structural layers of pavement is considered in the paper. The paper presents a method of technical and economic analysis, for which it is necessary to know the calculated deformation moduli of the materials being compared. Knowing the turnaround time for each of the options under consideration, it is possible, by comparing them with the payback periods, to more fully identify the technical and economic features of such options. The main criterion for the admissibility of the use of local material in the corresponding structural layer is the equal strength of pavement structures or individual structural layers made of local and imported materials. The criterion of economic feasibility of using local material can be written as an inequality. Using the principle of equivalence of systems, it is possible to replace individual structural layers of pavement, made of certain materials, with equivalent layers of stiffness from other materials, increasing or decreasing their thickness, depending on the strength characteristics of the materials themselves. The main condition for the technical feasibility of using local material has been determined on the basis of the condition of equal strength structures made from local and imported materials. A schedule for preliminary determination of the technical and economic feasibility of using local materials in the structural layers of road pavements has been built. The total value of the investment costs can be used as an additional criterion for the economic benefits of the compared options.

A methodological method based on the use of the theory of preferred numbers has been proposed in order to improve the most important parameters of the working bodies of noise mufflers. As a result of many years of scientific research, the authors have established a previously unknown theoretical relationship between the main series of preferred numbers, golden ratio and Fibonacci series numbers. A new direction in the development of number theory has been considered in the paper, its classification has been compiled, including the geometric theory of numbers, preferred numbers, containing a new basic series of preferred numbers using the Fibonacci sequence. New formulas have been obtained to determine the denominators of geometric progressions for the series of preferred numbers and the area of a circle. Determining the area of a circle using the new formula allows to get more accurate values. A new formula for determining the circumference of a circle has also been derived. The designs of perforated partitions have been developed, in which the laws of the new basic series of preferred numbers are used. Determining the area of a circle using the new formula allows you to get more accurate values. A new formula for determining the circumference of a circle is also obtained. The designs of perforated partitions have been developed, in which the regularities of the new basic series of preferred numbers have been used. A calculated substantiation of the main geometric and structural dimensions of noise mufflers is given using a mathematical model of a perforated golden partition and new basic series of preferred numbers, which allow to obtain a noise muffler design that has the lowest possible aerodynamic resistance with the maximum possible reduction in the noise level of exhaust gases from internal combustion engines. An innovative model of a noise muffler for reciprocating internal combustion engines with improved hydraulic and acoustic characteristics based on the theory of numbers is proposed in the paper. The theory of preferred numbers applies to any technical device.

Having proven its effectiveness in finding the best options for energy supply and energy consumption the exergetic method of thermodynamic analysis of complex heat and power systems has been widely recognized in recent years. However, its application is hindered by the lack of appropriate scientific and methodological heat technology support, especially if their application involves not only transformation of energy, but also transformation of substances. Heat treatment of concrete and reinforced concrete products belongs to such technologies. This article presents new scientific results related to the development of exergetic balances of the processes of preparation of concrete mixture in a mixer and heat treatment of a concrete product in a heat-technological installation. For each of these cases, the analysis of exergetic flows was carried out, the structure of the exergy of the concrete mixture and the hardening concrete was determined. Based on the analysis of the literature data on the chemical composition of cement clinkers, cements, and hydration products, new dependences have been proposed for calculating the exergy of the concrete mixture flow and the exergy of concrete under its heat treatment, including all their components, viz. thermomechanical, reaction, and concentration constituents. Absolute energy indicators have been developed. The calculation of the mentioned values was performed on a specific example with the use of the developed scientific and methodological support. In the second part of this paper, the results of the study related to the determination of relative exergetic indicators that allow evaluating the energy efficiency of the processes of heat treatment of concrete products in heat technology installations will be published. The results obtained in this paper can be used for the selection of energy-saving modes of heat-technological equipment intended for industrial heat treatment of concrete products.

The paper describes a technique for assessing the thermally stressed state of a concrete massif of a foundation slab made of a self-compacting concrete mixture. The proposed method consists in a preliminary calculation of temperature fields in hardening concrete. The objects of research have been self-compacting concrete mix and structural concrete in the structure mass. The choice of materials for the preparation of a concrete mixture is given and substantiated. The composition of self-compacting concrete has been used to assess the thermally stressed state. A binder with a reduced exotherm has been used in order to reduce the self-heating of concrete. Studies have been carried out to assess the specific heat release of the recommended cement depending on the initial water-cement ratio. The effect of a chemical additive on the rate and magnitude of the specific heat release of cement has been studied. The paper presents the main theoretical provisions and an algorithm for calculating the thermal stress state of a concrete massif. The finite difference method has been used to calculate the expected temperatures and their distribution in the structure mass, and the temperature stresses in the sections of the concrete mass have been calculated to assess the thermally stressed state. The performed calculations of the temperature fields have made it possible to estimate the maximum possible temperatures and temperature differences over the sections of the concrete massif depending on the initial temperature of the concrete mixture and the average daily temperature of the outside air. Analysis of the temperature distribution has revealed the most dangerous sections of the concrete mass. An assessment of the thermal stress state of the concrete mass has been made on the basis of the results pertaining to calculation of temperature fields. The calculation of temperature stresses in the most dangerous sections of the concrete massif has been performed. It is shown that the calculated value of the temperature stress can serve as a characteristic of the thermally stressed state of the concrete mass. The formation of temperature cracks in a concrete mass is possible when the calculated value of the temperature stress exceeds the actual tensile strength of concrete. Comparison of the calculated and actual values of temperatures in the sections of the foundation slab has made it possible to conclude that the calculations of the temperature fields and, as a consequence, possible temperature deformations are correct.

A schematic and structural solution of regenerative-utilization heat use in centralized heat supply systems was previously proposed in order to increase the efficiency of operation of heating networks located in non-passable channels. The impossibility of creating a full-scale experimental setup covering the required range of factors and the area of their change, the complexity of a passive experiment on existing heating mains led to the need to develop a virtual model based on the ANSYS sofware package. A six-factor experiment has been carried out on this virtual model. Regression equations have been obtained to determine the pressure required to provide air purging of the channel, as well as heat exchange with pipelines of direct and return network water located in the channel, and heat exchange with soil around the channel. In addition, a regression relationship has been derived to find the integral heat flux from the listed washed surfaces to the air flow. The transition from dimensionless to natural factors has been made in the paper. The most significant factors are identified with the help of Pareto cards. The obtained dependencies have been verified in Part 1 of the paper. The adequacy of the obtained regression equations has been determined using standard statistical estimation methods based on the calculated values of the Fisher’s, Student’s and other criteria. The response surfaces are presented and analyzed using two dimensional sections for a number of factor values at fixed values of one and a change in two most characteristic, physically significant for a given response function. They have been validated on the basis of the analysis of regression dependencies. The obtained regression equations cover almost the entire range of possible diameters of heating mains, which makes it possible to use them in the development of energy-saving projects.

In recent years, intensive research on urban transport has been observed. The search is about finding such solutions that will enable, among others: increasing the importance of public transport, matching transport for the needs of people with reduced mobility, increasing capacity, reducing emissions, energy efficiency (technical and organizational dimension through the organization of transport on demand), increasing the vulnerability to recycling and remanufacturing. The paper presents the main concept and technical solutions of the innovative transport system – HMASSUT Prometheus (Hybrid Modular Autonomous System for Sustainable Urban Transport), which combines the concepts of personal rapid transport and an electric vehicle at the L4 autonomy level (according to the Society of Automotive Engineers classification). An assessment of the effectiveness of an innovative transport system using indicators used in road engineering is given in the paper. The concept of simulation and optimization of the transport network is presented together with the theory of cellular automata.

The mixed problem for the telegraph equation well-known in electrical engineering and electronics, provided that the line is free from distortions, is reduced to a similar problem for one-dimensional inhomogeneous wave equation. An effective way to solve this problem is based on the use of special functions – polylogarithms, which are complex power series with power coefficients, converging in the unit circle. The exact solution of the problem is expressed in integral form in terms of the imaginary part of the first-order polylogarithm on the unit circle, and the approximate one – in the form of a finite sum in terms of the real part of the dilogarithm and the imaginary part of the third-order polylogarithm. All the indicated parts of the polylogarithms are periodic functions that have polynomial expressions of the corresponding degrees on an interval of length in the period, which makes it possible to obtain a solution to the problem in elementary functions. In the paper, we study a mixed problem for the telegrapher’s equation which is well-known in applications. This problem of linear substitution of the desired function witha time-exponential coefficient is reduced to a similar problem for the Klein – Gordon equation. The solution of the latter can be found by dividing the variables in the form of a series of trigonometric functions of a line point with time-dependent coefficients. Such a solution is of little use for practical application, since it requires the calculation of a large number of coefficients-integrals and it is difficult to estimate the error of calculations. In the present paper, we propose another way to solve this problem, based on the use of special He-functions, which are complex power series of a certain type that converge in the unit circle. The exact solution of the problem is presented in integral form in terms of second-order He-functions on the unit circle. The approximate solution is expressed in the final form in terms of third-order He-functions. The paper also proposes a simple and effective estimate of the error of the approximate solution of the problem. It is linear in relation to the line splitting step with a time-exponential coefficient. An example of solving the problem for the Klein – Gordon equation in the way that has been developed is given, and the graphs of exact and approximate solutions are constructed.

The purpose of this paper is a spectrum analysis of signals of various nature, construction of the signal scalogram using Morlet wavelet, modification of the scalogram to obtain a more informative graphic representation of the signal. Spectral analysis of the signal is constructed by means of the Fourier transform. A modification of the graphical representation of the result of the wavelet transform has been developed with the help of the Mathematica system. For this, a wavelet scalogram has been used as a two-dimensional representation of the original signal. A scale has been introduced on it for the value of the signal amplitude depending on the time and period of its constituent components. This graphical representation allows us to obtain additional information about the dynamic properties of the original signal. A modification of the representation of the original signal scalogram has been developed for a more complete spectrum analysis (determination of the period of the constituent components). The paper contains an example using a modified scalogram for the analysis of a signal containing two pulses, an audio signal and white noise. The basic wavelet in this case is the Morlet wavelet. A comparison of the scalogram, obtained using the built-in function, and the modified scalogram has been made in the paper. The disadvantage of the first scalogram is the impossibility of assessing the frequency of the signal; its advantage is the ability to assess the localization of the pulse. For a modified scalogram, the advantage is the estimation of the signal periodicity, and the disadvantage is the inaccuracy in determining the range of pulse localization. For spectrum analysis in Mathematica, it is recommended to use a combination of two approaches (using a standard built-in function to determine the localization of the pulse) and a modified scalogram (to determine the periods of the constituent components).

Waste generation in the life of people and enterprises is an inevitable process today. The level of utilization of municipal waste has increased on average to 23 % in Belarus. The paper provides an assessment of the existing systems for the collection and disposal of waste solid household items based on technological stages (preparation of waste for loading into a garbage collection vehicle; organization of temporary storage of waste in households, at enterprises; collection and removal of waste from the territories of households, organizations and enterprises; neutralization, processing and recycling of waste). The consequences of untimely collection of solid household and industrial waste are considered in the paper. The paper presents the factors that have a harmful effect on the human environment and the ecology of the territories of settlements and enterprises. An analysis of the effectiveness of the timely removal of such components in the systems of municipal services of cities and enterprises as an important component providing social, economic and environmental significance is given in the paper. At the present stage of the development of technology and available technologies, one of the most rational and economically justified ways of delivering waste to the areas for their sorting and processing is vacuum transportation using pipeline transport. Its application is justified for industrial zones and settlements with high and medium population density. Moreover, such a pipeline can be laid next to existing pipeline and other transport communications.

In the operation schemes of optical electronic devices (OED), such as digital autocollimators, direction finders, Shack-Hartmann sensors, as well as astro-orientation systems, projection measuring systems, geometric calibration schemes for OED, the photo-detector acts not only as a receiving device, but also as a measuring device. The tasks facing the OED photo-detectors. The solution to the problem is the use of several photo-detectors installed on one electronic board. Since OED photo-detectors act, inter alia, as measuring devices, it is necessary to perform their geometric calibration. Geometric calibration involves the measurement of interior orientation parameters used in the processing of OED images. Geometric calibration makes it possible to eliminate errors in mutual exposure of photo-detectors on one electronic board installed in the focal plane, as well as distortions introduced by the OED lens, primarily by distortion. The correctness of the interior orientation parameter determination is influenced by the relative position of the collimator, with the help of which the geometric calibration is performed, and the calibrated OED itself, i. e. the external orientation elements. The task is to separate the interior orientation parameters and the elements of external orientation. This is achieved using the method of mathematical processing of measured data in the forward and inverted positions of the collimator. This method of geometric calibration allows to use it for geometric calibration of OED with a large number of photo-detectors. The paper presents the results of the geometric calibration of the interior orientation parameters when the collimator projects a test object onto three photo-detectors of the OED layout. The factors influencing on the accuracy of the geometric calibration of the interior orientation elements for OED are determined in the paper. The developed method for geometric calibration of the interior orientation parameters for multi-matrix OED provides high measurement accuracy – not more than 0.1''–0.2''.

Metro Service has a huge impact on the development of urban transport infrastructure. The need to increase the efficiency of passenger transportation is caused by the rapid growth in passenger turnover as well as an increase in the distance from the outskirts of the city to the center. In connection with the need to develop a metro service network in Minsk city, which is confirmed by research in the area of passenger traffic in the main areas of the city, the CSM Bessac tunnel boring machine was purchased, which allows significantly to increase the speed of tunnel driving. The use of a mechanized tunnel boring machine in the traditional concept of the metro network construction, in which driving of tunnels is carried out after construction of stations, does not allow to use a shield with maximum economic efficiency due to the small extent of tunnels. There is also a need to build assembly-shield chambers and carry out works on disassembling and assembling the shield. The application of the new concept developed by Yu. S. Frolov and called “through driving” is actual in the conditions of the use of a mechanized tunnel boring machine. Its essence lies in the continuous driving of tunnels on the line section under construction and the consecutive construction of each station complex as the tunnel boring machine passes through it. To implement the concept of “through driving”, it is relevant to use a semi-closed construction method, in which the floor structure is constructed in an open way, and the other elements are closed. The available solutions of the metro stations constructed while using a semi-closed method of work have been analyzed in the paper. A detailed analysis has been carried out with due account of the adaptation to the construction conditions in Minsk, and the development of structural elements and assemblies of the platform area of the station, which is a two-cantilever vault with a developed transom part, resting on pile-columns of a circular cross section. Forces from the open ring of flexible tunnels lining are supported by a cantilever part of an arch and a bottom plate. The paper considers a design of a metro station, its main elements, their purpose and specificity of work, as well as optimization issues and the results of the design feasibility study.

Erosion is divided into two stages in accordance with the accepted design scheme for erosion of a soil dam during overflow. The paper deals with the first stage, when the downstream thrust prism is washed out. The key factor in calculating erosion deformations is the choice of the solid flow rate formula. Studies show that the mechanism of formation and transportation of solid runoff during erosion of dam models from sandy oils is very similar to that previously described by many authors for the condition of river channel erosion. The peculiarity of the process is that the erosion occurs at high speeds. Therefore, solid runoff almost immediately goes into a suspended state. To select the required formula, experiments have been carried out on models of dams made of sandy soils having various granulometric composition. It has been established that at high velocities under the considered conditions, the value of the solid waste flow rate depends solely on hydraulic characteristics of the flow. The influence of physical and mechanical properties of the eroded soil on the value of the flow rate of solid runoff is insignificant, and they may not be taken into account. Calculations have been carried out using formulas known from river hydraulics, which show that none of them gives sufficient convergence with experimental data. Based on the analysis of a large number of experimental data, a formula for the discharge of solid runoff for erosion conditions of dam models during overflow has been obtained in the paper. This has taken into account the fact that the dam erosion by the overflow has a high degree of stochasticity and is difficult to describe theoretically. This is especially evident in conditions of spatial erosion, when, simultaneously with the classical erosion of the bottom, the sides of the eroded hole periodically collapse, which is difficult to take into account in the calculations.

Nowadays there are a lot of modern technologies in electronic lexicography: speech synthesis technology, cross-referencing between dictionary modules, spell-checking functions, etc. The increasing availability of online information has necessitated intensive research in the area of automatic text summarization within the Natural Language Processing community. Belarusian scientists are also interested in this sphere and new lexicographical approaches for creating a linguistic database are shown in the paper. The authors present English-Belarusian-Russian electronic dictionary TechLex. This is the project of the 2nd English Department and the Department of Software for Information Systems and Technologies of the Belarusian National Technical University. The linguistic database of the dictionary is compiled not by the traditional method of processing a large number of paper dictionaries and combining the received translations, but by sequential processing of scientific and technical English-language periodicals. While the designing the dictionary the authors have taken into account the analysis of modern electronic multilingual translation dictionaries and created a client-server application in the Java programming language. The client part of the system contains a mobile application for the Android operating system, which has been tested on tablets and smartphones with different screen diagonals. The interface of the TechLex dictionary is designed taking into account the possibility of adding new subject areas and filling them with appropriate lexical material. The main advantage of our dictionary is that it is the first technical multilingual electronic dictionary having a Belarusian version.

Studies on the influence of applying various technologies for combustion knock reduction have been presented in the paper. Among others, investigation concerning the following: over-expanded cycle, variable valve timing, internal and exhaust gas recirculation, leaning the combustible mixture and cooling the in-cylinder charge were of the interest. The research works were focused on impact of these technologies on both knock intensity reduction, and engine performance and toxic emissions. Results presented in the paper were coming from experimental investigation based on in-cylinder combustion pressure data acquisition. Additionally, knock intensity calculation methods were discussed. They are based on incylinder combustion pressure pulsations. Combustion knock intensity expressed by the maximum peak of the incylinder pressure pulsations shows a strong negative correlation with both the EGR ratio and relative equivalence ratio – lambda. With respect to a catalytic converter installed on the exhaust pipe line, applying EGR appears as better solution for knock reduction then leaning the combustible mixture because the catalytic converter needs stoichiometric mixture for effective NO x reduction. Furthermore, application of the over-expanded cycle to the hydrogen or coke gas fueled IC engine significantly reduces intensity of potential knock by 50 % in comparison to Otto cycle for all loads. Additionally, over-expanded cycle contributes to increase in engine thermal efficiency. Summing up, all the presented measures and technologies can be successfully implemented into practice in stationary engines as well as in traction engines, both of them working on either natural gas or gaseous renewable fuels.

An experimental assessment has been made of the influence of electro-erosive modification modes for worn working surface of an cutter on the restoration of its cutting ability. The paper provides basic information on dental cutters. The provisions of the experimental research methodology are described, including a description of a device for modifying the worn surface of a dental cutter and a device for determining its cutting ability. Experimental data are presented and analyzed that reflect an effect on restoration of a cutting ability of a worn surface of a dental cutter, voltage of a storage capacitor and number of holes applied to it during its modification. Rational modes of modifying a worn-out surface of a dental mill that provide the greatest recovery of its cutting ability have been determined in the paper. It has been shown that with increasing voltage, the energy of the electric discharge acting on the treated surface increases, which leads to the formation of a single hole of a larger size on it, including metal flows along its edge that extend beyond the initial contour of the worn cutter teeth. These metal flows on the modified surface of the cutter play the role of peculiar cutting and deforming elements. It has been revealed that in the process of modifying the worn surface of the cutter, it is necessary to ensure that there is no overlap of the holes formed on it, i.e. the distance between the centers of adjacent holes should be greater than or equal to the size of metal deposits at their edges. In this case, the metal flows retain their original shape and have the highest height at these pulse parameters, which ensures a higher cutting ability of the modified cutter surface than when the holes are overlapped.

The paper considers spatial organization of energy facilities with an emphasis on modern practice of the Republic of Belarus. The efficiency of enterprise operation in any industry including power industry is largely due to their architectural and planning organization. Knowledge of mechanisms and specific features of the changes taking place here makes it possible to justify a promising strategy for project activities, and therefore, it allows to manage development processes of the industry and thereby avoid many negative consequences. Energy facilities are a typological unit of industrial architecture, their formation has been started due to transition of industrial production to electric energy. Today the typology shows functional approach in architectural shaping, it includes a fairly large variety of constituent units and demonstrates a tendency towards diversification. In Belarus energy facilities in the architectural aspect of their classification are limited mostly to thermal power plants operating on different types of fuel. Currently the diversification is developing in the following areas: construction of hydropower facilities (small plants on reservoirs, medium power plants, low-pressure plants, run-of-the-river hydraulic power stations), alternative energy (wind power stations, photovoltaic power stations and biogas plants) and conventional energy (thermal power plant, mini-combined heat and power plant operating on renewable fuel). The results of Belarusian practice in construction of all types of facilities (hydropower, alternative and conventional energy), peculiarities of the architectural and planning organization of facilities at the current stage, correlation with global trends in the development of industrial architecture have been characterized in the paper. The paper has determined typological features of alternative energy facility architecture, opportunities and directions for implementation of architectural approaches, problems and prospects to develop scientific support for the project process.

Waste of combined heat and power plants represents a certain danger to the environment, and hence the economic problems. However such waste contains substances that are advisable to use for production of construction and finishing materials. Technogenic products of water treatment from the Yuzhnaya combined heat and power plant (sludges of chemical water treatment – code 8410500) are a calcite mixture containing more than 64 wt. % calcite. The mineralogical composition of inorganic waste has been determined while using X-ray and IR-spectral researches. Mechanical activation of calcite inorganic wastes leads to grinding of calcite and a decrease in the amount of adsorbed water, which affects the increase in the content of silica frame structures, the reactivity of which directly depends on their quantity. Changes in the structure of silicon dioxide during mechanical activation are established according to IR studies. The results of X-ray and IR studies of the Zapolie deposit clay used in ceramic brick production technology make it possible to attribute it to raw materials with high reactivity. An experimental batch of ceramic bricks has been produced at JSC “Obolsky Ceramic Plant” with addition of calcite inorganic waste from combined heat and power plants. An X-ray diffraction analysis of samples of the obtained bricks having standard composition and with addition of waste has been carried out. The influence of calcite inorganic waste content in the feedstock on the process of ceramic brick structure formation has been stu-died in the paper. Addition of chemical water treatment waste containing calcium carbonate up to 15 wt. % to the Zapolye clay mixture helps to reduce a firing temperature and an appearance of the melt. This leads to crystallization processes of solid minerals from the melt and an increase in the amount of glass phase which contributes to improvement of strength properties in ceramic bricks. The possibility of using inorganic waste (sludges of chemical water treatment – code 8410500) of combined heat and power plants as a component of emaciated additives in clay raw materials in the process of ceramic brick production has been established in the paper.

In this article, the authors consider the possibility of using a hybrid energy storage system to even out the load profile of the enterprise. Solving the problem of rational use of energy storage taking into account the initial variable load schedule will significantly reduce not only the cost of electricity consumption by the enterprise, but also the costs of its production. Detailed characteristics of batteries with various types of electrolytes and supercapacitors are given. A model of the active scheme of a hybrid electric energy storage system consisting of a lithium-ion battery and a supercapacitor unit with the corresponding characteristics is presented. The model was carried out by using the SimPowerSystems software in MatLab. During the simulation, the temperature and the aging effects and of the batteries were not taken into account. The selfdischarge parameter of the battery was also not presented. As a result of the simulation, discharge characteristics of supercapacitors and batteries were obtained based upon which the expediency of their combined use for leveling load profiles of various types was substantiated. The paper presents the results of the simulation of operating modes of a hybrid energy storage device, combining the advantages of two types of energy storage devices, as well as a diagram of delivered power to the network, corresponding to the specified parameters. The paper provides a mathematical description of the increasing power by hybrid storage system resulting from the combined use of supercapacitors and batteries. The paper presents the dependence of the power increase ratio on the frequency and the pulse current duty ratio, which proves that the maximum possible output power of the hybrid storage system can be several times greater than the power of a single battery having the same parameters.

The aim of the research is to develop theoretical and methodological foundations of stimulating the production of intensive renewal goods in the Republic of Belarus in the context of increasing the competitiveness of enterprises. To achieve this goal, the concepts of “enterprise competitiveness” and “stimulating the production of intensive renewal goods” have been clarified in the paper. The material for writing the paper comprises the work of domestic and foreign scientists and economists, the data of research reports carried out by the author, as well as industrial development programs and official statements by state managers. General scientific methods (analysis, synthesis, historical and logical unity), a systematic approach have been used in the framework of the study. The paper substantiates the inadmissibility of reducing the essence of an enterprise competitiveness to its competitiveness in individual markets for goods and services. Increasing the competitiveness of an enterprise is considered as a result of its subjective activity, as a reaction to economic incentive measures at various levels (both external and internal ones). This has made it possible to determine competitiveness of the enterprise as its adaptive, innovative, personnel, organizational, managerial, technical and technological, and reproductive characteristics that ensure the acquisition and preservation of comparative advantages determined by the results of interaction with other entities on the basis of a combination of available economic resources. Economiс incentives for production of intensive renewal goods have been consi-dered at various levels. The paper presents a broad interpretation of stimulation the production of intensive renewal goods as crea-ting economic, institutional and organizational-legal conditions that contribute to increasing the competitiveness of the domestic light industry and the fashion industry. As a result of the study, measures that stimulate the development of production of intensive renewal goods have been proposed, their role in increasing the competitiveness of enterprises has been substantiated.

The paper considers theoretical and methodological foundations for studying network mechanisms of innovative development in the Republic of Belarus and in order to reach the purpose it is necessary to specify the concept of a systematic approach in the context of the study of the indicated mechanisms and develop a methodology for conducting such investigations. Systematic and historical approaches, principles of synergetics have been used as research methods. The paper substantiates the necessity to study the network mechanisms of innovative development in the Republic of Belarus from the point of view of a systematic approach. In this case, the author has refused traditional contrast of stable, essential, regularly repeating connections and relationships in the system to random, chaotic processes, and he has proceeded from the need to consistently apply a law of hierarchical compensation, as well as taking into account such features of the development of the modern economy as the rapid evolution of network technologies, further development of the risk economy, emergence of new challenges for traditional (including old industrial) industries. This has made it possible to define a systematic approach as a se quential and comprehensive examination of an object not as isolated from external influences, but as half-closed, but with an approach to an open system in which the synergetic processes generated by evolution of network technologies, development of the risk economy, and emergence of new challenges for industrial production (including traditional ones). It has been established that a consistent and comprehensive review of the network mechanisms of innovative development in the Republic of Belarus requires not only to determine initial categories and concepts, to show general and special determining factors, genesis and development trends, but also to conduct constant monitoring aimed at identifying dynamics of needs and interests of political-economic and economic entities involved in this process, as well as material and social technologies for implementation of the needs and interests.

The papers considers the following six innovative models of marketing activity: event marketing, brand immersion, geolocation internet-marketing, lead generation internet-marketing, single commodity distribution and trade-service network, van selling. Even marketing is a systematic execution of events used as a platform for presentation of products while attracting attention of potential consumers and exerting emotional impact on them. The model is directed on four targeted objects: consu-mers, partners, market and own personnel. Brand immersion is the involvement of consumers in emotional perception and expe-rience of brand. Geolocation internet-marketing is data penetration (location) of a large circle of consumers via the Internet on a wide geographic site. Lead generation internet-marketing is attraction (generation) of potential consumers (leads) via the Internet. Single commodity distribution and trade-service network is an aggregate of firms or individuals which and who take over or help to transfer ownership of a particular product or service to someone else on their way from a manufacturer to a consumer as well as providing trade and service services. Links of the commodity distribution network are: manufacturers, distributors, wholesalers, dealers, brokers, agents, consignees, retailers, service and repair companies. Van selling is wholesale trade with prompt delivery of goods to consumers and placing orders on the spot (sale from wheels). The essence of each model has been revealed and their values and advantages in commercial activity have been considered in the paper. It has been shown that an introduction of innovations is hindered by various factors: stereotypes of thinking, organizational difficulties, additional material costs, possible lack of direct economic benefits for some participants in the trade. All this makes it difficult to create and implement innovations in trade practice including the use of computer technologies in trade, for example, in the field of public procurement. The paper proposes methods for eliminating these obstacles.

The paper is devoted to study of the modern innovative environment in the Republic of Belarus, its most important characteristics, problem areas. A conceptual apparatus has been given in the paper that determines an innovative environment, institutional conditions that contribute to its formation, priorities for development of research activities have been given and specified in the paper with due account of the requirements for modernization of the economy. The paper presents a definition of the innovation system which is given by distinguished western scientists and researchers who have been seriously engaged in its study. The aim of the research is qualitative, quantitative analysis of the innovation environment of the Republic of Belarus and also a comparative analysis of the innovation environment of the Republic of Belarus, its main components (legal, financial support, institutional specific features of function- ning) against the background of Russia and Kazakhstan. The paper contains SWOT-analysis which is used to find possible directions of innovative development of the economy of the Republic of Belarus on the basis of the existing national economic system and taking into account the peculiarities of the national mentality. Attention has been attracted to the fact that such factor of innovative development as “innovative behavior of employees” which is one of the key factors of competitive advantage in the world's leading companies is very important for evaluation and analysis of the innovation environment. The paper presents an own model of the national innovation system which consists of three subsystems: human capital, technological infrastructure and innovation support subsystem. Process of creating innovative products has been shown in the paper and these products make it possible to understand interrelation of the innovative ideas market and the market of innovative product. It is proposed to use a categorical apparatus of legal acts of the Republic of Belarus to describe and characterize the markets of innovative ideas and innovative products. The analysis has been performed while using legislative acts, resolutions of the Government of the Republic of Belarus, analytical articles, conference materials, electronic resources, official statistics of the National Statistical Committee of the Republic of Belarus.

Hybrid electric powertrains in automotive applications aim to improve emissions and fuel economy with respect to conventional internal combustion engine vehicles. Variety of design scenarios need to be addressed in designing a hybrid electric vehicle to achieve desired design objectives such as fuel consumption and exhaust gas emissions. The work in this paper presents an analysis of the design objectives for an automobile powertrain with respect to different design scenarios, i. e. target drive cycle and degree of hybridization. Toward these ends, four powertrain configuration models (i. e. internal combustion engine, series, parallel and complex hybrid powertrain configurations) of a small vehicle (motorized three wheeler) are developed using Model Advisor software and simulated with varied drive cycles and degrees of hybridization. Firstly, the impact of vehicle power control strategy and operational characteristics of the different powertrain configurations are investigated with respect to exhaust gas emissions and fuel consumption. Secondly, the drive cycles are scaled according to kinetic intensity and the relationship between fuel consumption and drive cycles is assessed. Thirdly, three fuel consumption models are developed so that fuel consumption values for a real-world drive cycle may be predicted in regard to each powertrain configuration. The results show that when compared with a conventional powertrain fuel consumption is lower in hybrid vehicles. This work led to the surprisingly result showing higher CO emission levels with hybrid vehicles. Furthermore, fuel consumption of all four powertrains showed a strong correlation with kinetic intensity values of selected drive cycles. It was found that with varied drive cycles the average fuel advantage for each was: series 23 %, parallel 21 %, and complex hybrids 33 %, compared to an IC engine powertrain. The study reveals that performance of hybrid configurations vary significantly with drive cycle and degree of hybridization. The paper also suggests future areas of study.

The lifetime of traction battery systems is an essential feature of the economy of battery electric urban bus fleets. This paper presents a model for the analysis and prediction of the lifetime of urban electric bus batteries. The parameterization of the model is based on laboratory measurements. The empirical ageing model is an integral part of a three-stage battery model, which in turn is an important component of the methodology for the overall system design, evaluation and optimisation of battery electric urban bus fleets. In an equidistant closed simulation loop, the electrical and thermal loads of the traction battery are determined, which are then used in the ageing model to calculate the SOH (state of health) of the battery. The closed simulation loop also considers the effects of a constantly changing SOH on the driving dynamics of the vehicles. The model for lifetime analysis and prognosis is presented in the paper, placed in the context of the overall system design and demonstrated by means of a practice-oriented example. The results show that the optimal system design depends, among other things, on whether an ageing simulation was used. Taking battery aging into account, system costs in the example presented can be reduced by up to 17 %.

Investigations have been carried out in respect of structural steel and titanium alloy fatigue at various cyclic loading frequencies and these investigations have made it possible to reveal regularities in changes of parameters pertaining to fatigue resistance and stability behaviour of the tested materials. A change in cyclic loading frequency affects duration of a single (during one cycle) stay of the material in the loaded state and it has an impact on its durability. In addition, with an increase in frequency of load cycles, deformation rate becomes higher, and stress build-up time is decreasing, while distortion of a crystal lattice is increasing due to reduction of time for development of a weakening process. This process is accompanied by an increase in intensity of grain crushing into fragments and blocks, and their disorientation. Tests on cyclic strength of the studied material samples have been carried out at various frequencies and at a room temperature according to the following loading schemes: cantilever cyclic transverse bending of a flat sample; cantilever bending with rotation of a cylindrical sample; axial tension on a pulsating cycle. Quantitative estimates of a fatigue resistance index in the form of slope tangent in a left branch of the fatigue curve to a cycle axis have been used in order to analyze and evaluate performance and stability of the tested materials. Methods for mathematical statistics have been applied to process the obtained results. Graphic dependences of fatigue curves have been plotted in logarithmic coordinates that allowed to obtain straightening of approximating lines for experimental data. The investigations have revealed that loading frequency has an ambiguous effect on fatigue resistance due to some differences in materials in respect of their reaction to changes in a load spectrum within different areas of the fatigue process, but at the same time it has been found that an increase in fatigue strength leads to a slope decrease in the fatigue curve regardless of a decrease or an increase in a load frequency. The paper proposes a new approach to assess a cyclic strength and durability of materials, and it comprises a system of parameters including a relative coefficient of limited endurance, a correlation coefficient and a slope tangent of the fatigue curve. Behavior dynamics for real machine parts and structures made of these alloys under operating conditions has been indicated in the paper.

The paper has substantiated an expediency to fix lenses with a thin center (biconcave, flat concave and negative meniscus) to a non-operational cylindrical surface. This avoids their temperature distortion at the blocking stage which is a reason for occurrence of irremovable micro and macro errors on executive surfaces of a component after its unblocking and it causes astigmatism in an image which is formed by an optical-electronic device. The paper considers a method for attachment of a lens to its side surface and it contains a design description of the device for mechanical attachment of the studied lenses during their simultaneous double-sided abrasive processing under free-grinding conditions. The paper presents a methodology for determination of a stressed state in lenses, which is based on a mathematical model of a uniform elastic isotropic deformation of a solid body. This approach takes into account a finite element method which consists in an approximation of a body under study with the help of a model presenting a set of elements with a finite number of freedom degrees which are interrelated at node points. The investigations have been executed with the purpose to study a nature of deformation distribution in a lens which made it possible to establish a directly proportional dependence of displacements in the center of the part on the magnitude of clamping forces. The paper reveals an insignificant influence of a clamping force magnitude and elastic characteristics of a lens on an optimum position of an application plane of its clamping forces. A non-contact method for monitoring errors on a polished lens surface using an interferometer with a reference front surface has been proposed in the paper.

A great attention has been recently paid to development of ultrasound technologies for treatment of blood vessels throughout the world. Authors of the paper have developed a new effective treatment method and ultrasound equipment that allow to carry out destruction of intravascular formations with simultaneous increase in elasticity of a vascular wall together with cardiologists from Belarusian Medical Academy of Postgraduate Education and Republican Scientific and Practical Center “Cardiology”. Advantages of the method are absence of necessity in surgical intervention, low probability of complications, low cost of treatment. The main component of the developed ultrasonic equipment is a tube-type stepped concentrator-waveguide having a spherical tip at a distal end with a single axial hole of 0.5 mm-diameter and three radial holes of 0.3 mmdiameter located at an angle of 120° relative to each other. The main effect for application of the concentratorwaveguide is achieved by ultrasonic vibromechanical action of a spherical tip on intravascular formation with subsequent removal of destruction products by their aspiration from a vascular bed. An additional effect is provided due to cavitation action on vascular formation and vessel walls by flow of fluid supplied via an internal cavity of the stepped concentratorwaveguide through the holes in the spherical tip. This contributes to a significant improvement in elastic properties of a vascular wall in atherosclerosis and diabetes. It is necessary to ensure high accuracy and quality of surfaces for the formed microholes in order to achieve maximum efficiency of the cavitation jet impact on intravascular formations and on the vascular wall. According to the analysis results on specific features of existing methods for small-diameter hole shaping, an electrochemical hole cutting method has been proposed which allows to obtain accurate micro-holes with a diameter of 0.3 mm and high surface quality in parts of small cross section and rigidity. The paper presents results of study on effect of electrochemical holes cutting parameters (voltage, concentration and consumption of electrolyte) on size and shape of the formed microholes. Main modes of electrochemical holes cutting process have been developed which allow to form micro-holes in a spherical tip of a tubular concentrator-waveguide with required accuracy, dimensions and shape.

The task of controlling multi-link robots with manipulators for implementation of high-tech processes in industry has been considered in the paper. The paper presents sequential steps of using computer technology in construction of robotic-manipulators, including mathematical, algorithmic, and hardware and software tools for creating a multi-drive mechatronic system controlled by OMRON industrial microcontroller. A kinematic scheme of a robot manipulator has been described in the paper and it performs the following two types of movements – rotation around the z axis and rectilinear movement of a working element along a turning radius with precise positioning at a given point in the working space. Electromechanical design of the manipulator allows to ensure transportation of production objects in accordance with a given technological process. For designing the technological process of transporting production objects, a software module has been developed that makes it possible to automate description of basic operations for movement of the robot manipulator working body with subsequent automatic generation of a command sequence for a control program ensuring operation of electric drives in manipulator links in real time. To speed up the process of designing trajectory of the working body, a spatial simulation model of a robot-manipulator in the MatLab-Simulink environment has been developed. The paper considers a generalized diagram of a mechatronic control system for a robot-manipulator based on the OMRON programmable logic controller operating under control of a program developed in the programming environment Sysmac Studio Automation. A program for a programmable terminal with interface elements and animation elements has been developed for industrial use of the mechatronic system during adjustment and operation period. The paper provides an appearance of a robot-manipulator prototype. The developed mechatronic system of the robot-manipulator can be technologically oriented towards solving other problems of industrial production.

The paper considers principal features and specific character of architectural design for health care institutions. Main designing stages, missions and complexities for every successive designing step have been revealed in the paper. The paper presents specific features, main stages and design approaches to designing of modern health care facilities, comfortable architectural environment of health institutions, which have been formed on the basis of the analysis of advanced international experience in the field of designing healthcare facilities. The proposed approaches are based on modern experience in designing medical buildings over the past decade in the developed countries. A special attention has been paid to obsolete methods for architecture-planning organization of healthcare facilities and modern approaches to arrangement of engineering and other systems which significantly influence on economical efficiency, quality, comfort and effectiveness of architectural environment in healthcare institutions. Every healthcare facility, every separate department are considered as unique in their essence, for this reason it is not so easy to reflect modern technological solutions and architectural tendencies. The paper contains an attempt to attract attention of architects to the complexity in designing of a building to be constructed, to find ways which will help to reach its step-by-step solution. It has been noted as well that there is a necessity to arrange interaction between an architect and a medical technologist. Modern medical departments and hospitals have been recently designed and built in the Ukraine, but they are in increasingly short number. These facilities have been constructed due to decision makers who, in spite of diverse difficulties, lack of information and specialists, lack of proper funding, etc., are trying to do their best in order to reach the modern level of desingning and construction of hospitals. So-called “typical” medical projects of 70-ies and 80-ies continue to be implemented up to now. This is certainly due to inadequate funding, but such economy has at the end rather high cost.

The paper presents a complex of laboratory and theoretical studies of physical and mechanical properties in centrifuged concrete while using samples of sectoral cross-section which are cut in layers from a finished product. A post made of concrete having B40 grade for compression strength and manufactured while using centrifugation with the help of РТЦ-5 machine. Assessment of heterogeneity across section thickness has been carried out by visual determination of composition changes in cross section, determination of strength, density of the obtained concrete samples, and water content over cross section of concrete mix. According to the results of a visual study on composition of a concrete structure it has been revealed that 1/8 part of the structure (from an inner surface) does not have a large aggregate. Later, as it moves to periphery, there is an increase in coarse aggregate and a decrease in size and number of cells between grains of gravel. An analysis of experimental data has shown that properties of the centrifuged concrete in samples being sawn in layers change significantly: density of concrete in samples of an inner layer is lower by 8 % than in samples of an outer layer, and compressive strength of concrete – by 34 %, water content of concrete mixture of samples of the inner layer has turned out to be by 43 % higher than in samples of the outer layer. Approximating curves showing regularities of changes in density, concrete strength, water content of concrete mixture over thickness have been constructed in the paper. Linear and exponential equations have been obtained that describe changes in physical and mechanical properties of centrifuged concrete over section depending on structure properties as a whole, which, taking into account the obtained correction factors k1 and k2, can be used with an acceptable level of confidence in practical calculations of centrifuged concrete structures. Relationship between strength of centrifuged concrete varying over cross section and action of a centrifugal force of inertia has been revealed in the paper. An equation has been obtained that relates the strength of centrifuged concrete to its density. Analysis of the research results makes it possible to assert that the main source of loading perception in centrifuged concrete structures is outer layers.

However, the ECP in its classical form has a number of significant drawbacks. One of them is a dependence of treatment modes and electrolyte compositions on the processed material. In addition, aggressive expensive electrolytes that require special technologies for disposal are used for ECP. Electrolytes in ECP often require heating to a temperature of 60–90 °C. Processing at such temperatures causes significant harm to the environment and production personnel. To eliminate the existing disadvantages of the ECP and expand its technological capabilities, a processing method with application of pulsed unipolar and bipolar modes has been proposed. As a result, fundamentally new processes of pulse ECP with a pulse duration of 0.05–20.00 ms have been developed. They provide a reduction of energy costs for the process and high efficiency of polishing in comparison with traditional DC polishing. The rate of smoothing micro-roughness of the treated surface related to the total metal removal is significantly increased. The use of pulse modes in comparison with traditional ECP allows processing in universal electrolytes of simple compositions based on sulfuric and orthophosphoric acids without addition of chromium anhydride. Application of the developed pulse modes, which will provide at low metal removal a significant change in surface roughness, is the most appropriate for the ECP of precise parts, products or parts of small cross-section and rigidity, such as medical devices for minimally invasive surgery, precision engineering parts, etc. The paper presents results of a study for influence of pulsed unipolar and bipolar ECP modes on the surface quality of stainless steel specimens, as well as a comparative analysis of the efficiency of using pulsed ECP modes instead of DC polishing. The technological parameters of ECP using pulsed modes, providing the highest quality surface polishing with high efficiency of micro-roughness smoothing and low energy consumption have been established in the paper.