Abstract. Aim. Despite the obvious expediency of their widespread implementation, gas turbine (GT) and combined cycle gas turbine (CCGT) plants were only used in limited quantities in the former USSR and CIS countries. Due to the exhaustion of possibilities to increase the fuel use efficiency and return on investment (ROI) in steam-turbine combined heat and power (CHP) plants, the development of GT and CCGT plants becomes an urgent problem. In current global practice, the primary fuel for gas turbines and combined cycle gas turbines is natural gas. However, until recently, there has been a lack of experience in the design, construction and operation of GT and CCGT plants in the CIS countries.

Method. Due to the ad hoc nature of research in this area, it was necessary to systematise the results of existing studies and assess the state of research at the world level taking regional characteristics into account.

Results. The article presents the main considerations and potential effectiveness of the use of gas turbines. Basic gas turbine construction schemes are investigated along with their techno-economic characteristics and an assessment of their comparative utility.

Conclusion. Considering the widespread availability of natural gas, it is recommended that gas turbine and combined-cycle plants be installed as part of the process of technical re-equipment in the fuel and energy complex, industry, agriculture and municipal energy sectors as part of the design and construction of new energy sources in the light of positive world experience and the current level of development of gas turbine technologies. Ubiquitous implementation of gas turbine units in the centres supplying heat and electric loads will reduce the regional economy’s need for energy fuel and ensure an increase in energy capacity without the need to construct new complex and uneconomic steam turbine power plants. 

Abstract. Aim. Due to the current priority given to energy conservation issues, a promising research avenue in the field of refrigeration consists in the developing of energy-saving systems based on heat-recovery absorption refrigerators. The aim of the work is to study the possibility of using a water-ammonia absorption refrigeration machine to increase the efficiency of food production facilities.

Method. Based on an analysis of the initial enterprise data, the possible operating modes of the refrigeration machine were determined considering the various types of heating and cooling sources proposed in the task specification. The identification of the characteristics of single-stage and twostage absorption schemes confirmed the possibility of increasing the enterprise's efficiency through the use of secondary energy resources.

Results. The choice of initial data for the design of a singlestage absorption water-ammonia refrigeration machine (AVXM) was justified on the basis of a preliminary analysis carried out to calculate the size of the degassing interval. The calculation was carried out using a ξ – i diagram for the ammonia water solution.

Conclusion. Two prior conditions for the design of a high-performance absorption water-ammonia refrigeration machine were determined on the basis of an analysis of four conditions set by the customer. For operating conditions with a low degassing interval value, a scheme for an absorption water-ammonia refrigeration machine employing two-stage absorption is proposed.

Abstract. Aim. The aim of the study is to analyse the problem of heat dissipation in high-power transistors and develop devices for their thermal stabilisation when used in electronic equipment.

Method. A method is proposed for testing power transistors using a device to to ensure thermal stabilisation in the stating volume by means of a two-position temperature controller along with a model for the use of these components in electronic devices. The proposed devices support high thermal stabilisation accuracy of power transistors in a radioelectronic device system allowing temperature to be maintained at a given level with high accuracy by means of a thermoelectric battery.

Results. Device designs were developed for increasing the accuracy of thermal stabilisation of power transistors with high efficiency, low energy consumption and small size.

Conclusion. Based on the results of experimental studies, optimal designs for devices for the thermostabilisation of radioelectronic device components that dissipate significant power during their operation are presented. The devices can be used to increase the accuracy of thermal stabilisation of the radioelectronic device element by means of a working substance whose melting point coincides with its thermal stabilisation temperature. The developed devices have the following functions: the thermoelectric battery sections of the thermoelectric battery will be sequentially disconnected depending on the electrical signals from the temperature sensors to which the solid phase of the working substance has moved. The battery of the thermoelectric module (TEM) removes excess heat from the heat-stabilising substance while maintaining the required temperature of the radioelectronic device element. Excess heat from the heat-generating junctions of the TEM battery is removed by the heat exchanger. During melting of the working substance, the temperature of the thin-walled metal container – and, accordingly, the temperature of the CEA element – can be maintained at a constant value equal to the melting temperature of the working substance. 

Abstract. Aim. Hydraulic rotary vane motors rely on the principle of torque maintained at a nominal pressure. In this case, the most important parameter of the torque is its nonuniformity. The problem of determining nonuniform torque in hydraulic motors having ten and twelve vanes is investigated with the aim of ensuring the maximum stability of this parameter.

Method. Braking torque occurs on the vanes of hydraulic rotary vane motors due to the pressure of the working fluid on the stator; the theoretical expression for torque does not take the braking effect of the vanes into account. Therefore, an expression is compiled for the braking torque of the vanes with a type of stator curve that provides constant acceleration of the vane relative to the rotor.

Results. Plots of changes in braking torques were constructed for 10- and 12-vane motors. Ratios of the minimum and maximum braking torques equal to 0.33 and 0.5 for motors with ten and twelve vanes, respectively, were obtained.

Conclusion. The torque nonuniformity coefficients for hydraulic motors for the given parameters of d =11,6% and d = 8,8% for motors having ten and twelve vanes, respectively, were obtained. The results of the analysis of the obtained parameters indicate a slight increase in the nonuniformity of torque in a ten-vane motor. In this case, a decrease in the number of vanes leads to an increase in the mechanical efficiency of the hydraulic machine.

Abstract. Aim. The article presents a thermoelectric heat exchanger / heat transfer intensifier design for ensuring the thermal regime of electronic equipment located in external installations.

Method. Methods for modelling heat exchange processes were applied.

Result. A thermoelectric system is proposed, consisting of a heat exchanger / heat transfer intensifier component located in an external installation. In structural terms, the external installation comprises a compartment disposing electronic heatgenerating components, in which are located channels for ventilating external air, while a second compartment contains elements that require to be sealed from external influences, in cluding contact with external cooling air. A mathematical model is provided for determining the temperature of air flows from the heatexchange surfaces of a thermoelectric system (TES), as well as the limiting length of a thermoelectric system to achieve equal output temperature at given supply currents of thermoelectric batteries.

Conclusion. On the basis of the conducted studies, it is concluded that a longer thermoelectric system for ensuring the intensification mode corresponds to an increased difference in the temperature of the coolant at the inlet. The temperature of the air flow at the outlet becomes lower with a further increase in length due to the thermoelectric heat exchanger entering the operating mode of the thermoelectric refrigeration unit.

Abstract. Aim Currently, the implementation of computational experiments to determine the probabilistic-temporal characteristics of protection functions for automated information systems is a complex and costly task. In order to study the dynamics of transitions between the states of this type of system, it is necessary to develop a mathematical model and an algorithm for computing the corresponding characteristics.

Method. To achieve this goal, a mathematical model of the information security system was developed in the MATLAB software environment. The main advantages of this software environment consist in a high level of visualisation, the ability to modify models to analyse other systems of this type and the availability of integration tools with other software products.

Results. The article presents a numerical and analytical model of a system for protecting information from unauthorised access. The functional dynamics of the system are described using a stochastic Petri net. In order to solve the integral equations and determine the probabilities of reaching the final state in a given time, the Laplace transform is used. The solution is carried out in an analytical mode to obtain an explicit form of the dependences of the probability-time characteristics of the system on the probabilities of transitions between states and the average times the system stays in each state. The paper presents the results of calculating the probability-time characteristics of the “Turning on the personal computer and user identification” subsystem of the “Guard NT” system for preventing unauthorised access to information.

Conclusion. The developed model, which can be used to study the dynamics of transitions between states of an information protection system against unauthorised access in an automated system, as well as to optimise the time it takes to complete functional tasks, can also be used to improve the operational efficiency of these systems.

Abstract. Aim Important contemporary trends in the theory and functional practice of secure automated systems at informatisation facilities of internal affairs bodies include an increase in the number of threats realised through remote unauthorised access (network attacks) on confidential in-formation resources, as well as the increasing complexity of implementing mechanisms aimed at providing protection from such attacks. In order to increase the effectiveness of existing and prospective automated security systems at the informatisation facilities of internal affairs bodies, it is necessary to identify and analyse typical network attacks aimed at components and software comprising these systems.

Method. The method for solving this problem consists in a comprehensive analysis of the process of implementing network attacks on automated systems when they are used in secure mode in the informatisation facilities of internal affairs bodies.

Results. Based on the analysis of information held in the security threat database developed by the Russian Federal Service for Technical and Export Control (FSTEC), modern features and operations of secure automated systems on the informatisation facilities of bodies of internal affairs and the results of a survey of experts in the field of information protection of allocated in accordance with the classification typology, eight types of dan-gerous attacks on automated systems of the internal affairs bodies are described taking into account their sources, objects, effects and possible consequences of implementation.

Conclusion. The presented results are of use in further studies to conduct a quantitative assessment of the danger of typical attacks and for developing a private model of actual attacks for a specific automated system, taking into account their functional features in secure mode operations at the informatisation facility of the internal affairs body.

Abstract. Aim.When conducting engineering and geological surveys at the conceptual stage of the feasibility study, it is necessary to create an automated system that allows the designer to take all possible factors into account and choose the most optimal design solution for the shoring of excavations.

Method. The study is based on dynamic programming methods based on the principle of Bellman optimality. Logical convolution matrices are applied according to the dichotomy method.

Results. As a result of the logical convolution of the aggregated criteria of the environmental parameters K12 along with the parameters of the surrounding buildings K34, a comprehensive assessment of the design solution for a foundation shoring fence is obtained such as to ensure the technical characteristics and safety of the development zone. However, a considerable influence on the choice of the design solution for the building envelope is exerted by the cost of its construction. Therefore, the indicator of a comprehensive assessment of the shoring fence considering the economic efficiency of the KOE is obtained by combining the indicator of a comprehensive assessment of the foundation shoring fence KO with the criterion of economic efficiency of the design decision K5.

Conclusion. The analysis of methods for solving optimisation problems demonstrates that the method of complex estimates based on the theory of active systems is optimal for the task of evaluating design solutions for foundation shoring fences.

Abstract. Aim. The aim of the study is to develop algorithmic support based on a frame model for information retrieval and selection of a flexible manufacturing system (FMS), as well as its technical units and control system in accordance with a process flow diagram.

Method. An intelligent method based on a frame model is used in order to create a search and selection algorithm. The FRL programming language was used for programming the frame model.

Results. In accordance with the published guidelines for ensuring the management and operation of archival design work, a comparative analysis of information support algorithms was carried out to in order to select flexible production systems (FPS) comprising standard elements, production modules, layout schemes and a set of information about their parameters or the location of documents. The model for creating algorithmic support was based on the modelling frame for the effective search and selection of the FMS, while its production modules and active elements were implemented in accordance with the scope of production and the purposes of each technical unit.

Conclusion. To ensure the reliable functioning of the FMS automatic control system, an algorithm is proposed for searching sensors based on frame slots and achievable positioning errors of industrial robots and technological equipment. An algorithm for locating sensors and controlling the active elements of an FMS production module is presented.

Abstract. Aim. Accurate knowledge of the extent and local distribution of pollution plays a key role in many areas of life.

Method. Although there are many well-known and generally-accepted methods for obtaining the intended data, these methods do not give a satisfactory result in cases when it is necessary to determine the exact parameters of pollution quickly and in a relatively small area (e.g. an industrial zone of several square kilometers, a residential area, etc.) and to determine changes in these parameters as expressed numerically. Small UAVs (multicopter with fixed or rotating wing) were equipped with sensitive detectors for gamma rays and polluting gases, including the assignation of flight data coordinates to the measured data. Such informational groupings provide the opportunity to determine the distribution of radiation or air polluting gases. Using this method, it is possible to identify and localise illegally-stored or illegally-released gamma ray emitting materials, continuously monitor pollution caused by chemical disasters and determine the spatial distribution of pollution.

Results. The article presents systems based on practical experiments, which, in the case of using a gamma detector, allow the localisation of objects using low radiation doses along with a high-quality map of gamma radiation in a specific area; and, in the case of gas sensors, the visualisation of the spatial distribution of a polluting gas. The method is used primarily in the field to detect gamma emitters with low activity or to analyse the emission of industrial facilities with the emission of pollutants.

Conclusion. The combination of spatial coordinates with remote sensing data comprises an effective meas-urement method. The developed system is generally applicable for mobile platforms equipped with sensors. The systems are designed to provide fast, efficient and reliable measurements that can be used for both detection and control. The type of pollutants to be measured depends on the sensors used. The experiments also indicate that, when replacing the used sensors, it may be necessary to change the processing of the measured data in accordance with the characteristics of the particular sensor; however, in general, data processing and visualisation of the results can be carried out in practice.

Abstract. Aim. Modelling and calculations were were carried out to justify the tactical capabilities of gas and smoke protection units of the fire and rescue units as primary units carrying out fire reconnaissance and rescue of victim s of fires. A methodology for assessing actions of personnel of fire departments when rescuing victims was analysed.

Method. An experimental justification is given for the need to adjust the calculation methods for determining the working parameters of gas and smoke protection units when organising mass rescue of victims of a fire. A model is proposed for considering the actions of the fireteam of a gas and smoke protection service based on graph theory. Various approaches to forecasting operational parameters of gas and smoke protection units in fire services are considered.

Results. Factors determining the limiting parameters of the gas and smoke protection units are presented along with examples for calculating operational parameters during mass rescue of victims of a fire.

Conclusion. A conclusion is formulated regarding complicating factors of the work of the personnel of the gas and smoke protection service in the coefficient, considering the necessary air supply for the return trip, unforeseen circumstances and average air flow.

Abstract. Aim. The aim of the study is to develop an environmental passport based on the structure of integrated environmental safety for construction projects. With each year that passes, environmental problems are coming increasingly to the fore. As part of mitigation efforts, an environmental passport is required to assess and control the environmental safety of construction areas and building sites.

Method. The study is based on the development of a sound model of integrated environmental safety in construction projects and a methodology for calculating its indicators, in particular, the indicator of “degree of concentration”. The methodology of ranking the factors by importance is applied.

Results. The structure of a building site's environmental passport is presented, taking the entire spectrum of its direct impact and environmental pollution into account, as well as the indirect impact, energy efficiency and autonomy of the site. The scope of the environmental passport comprises the entire building lifecycle, from design to operation and liquidation. An environmental passport en-ables the identification of problematic impacts on the geophraphical area from an environmental point of view, as well as giving recommendations for resolving problems. The threshold of environ-mental safety is set for each geographical area under assessment (i.e., for each building project and geographical area, it is determined by the composition of relevant factors) and the existing level of environmental pollution is determined along with the ecological reserve of the area and its steady state range, i.e., the acceptable level of deviation of environmental safety indicators, which depends on temporary factors and the objective reality of the functioning of the infrastructure of the evaluated territory. For the design and construction of building projects, indicators of environmental reserve and technogenic pressure of the facility are of fundamental importance when making decisions.

Conclusion. The article presents a rational assessment of the main indicators of the environmental pass-port, providing the structure of a comprehensive assessment of environmental safety. The research results are presented and the scope of the environmental passport proposed in the assessment of geo-graphical areas and evaluation of facilities and design.

Abstract. Aim. The purpose of the study is to determine the optimal location of supports used in the floor slab of an industrial building.

Method. In order to determine the optimal arrangement of the columns, a Monte Carlo algorithm was used in combination with the finite element method. The calculation was carried out on the basis of the theory of elastic thin plates.

Results. The article presents a solution to the problem of determining the optimal location of a given number of point-supports of a floor slab n from the condition of minimum objective function. For the objective function, the maximum deflection of the slab, the potential energy of deformation and the flow rate of reinforcement were selected as variables. The selection of reinforcement was carried out in accordance with current generally-accepted standards for the design of reinforced concrete structures. The calcu-lations were performed using a program developed by the authors in the MATLAB computing environment. The results are given for n = 3,4,5. The algorithm, which has been modified for a large num-ber of supports n, is presented alongside a comparison of the basic and modified algorithm with n = 25. The possibility of a significant reduction in plate deformations with an irregular arrangement of supports compared to a regular distribution is shown.

Conclusion. A method is proposed for finding the rational locations of point supports for a floor slab for a given quantity from the condition of min-imum deflection, potential strain energy and consumption of reinforcement materials based on the Monte Carlo method. This technique is suitable for arbitrary slab configurations and arbitrary loads. A modification of the algorithm is presented that is suitable for a large number of supports. The test example shows that the maximum deflection can be reduced by 42% when using an irregular support configuration compared to regular column spacing. In the considered examples, the position of all the supports was previously considered unknown, but the developed algorithm easily allows for stationary supports, whose position does not change.

Abstract. Aim. An integral part of an energy audit of buildings and structures consists in thermal imaging diagnostics. This permits an evaluation of the heat-shielding properties of the enclosing structures of buildings in order to control the functional and operational status of engineering systems, as well as to identify implicit (invisible) and explicit (visible) defects in them. The aim of the work is to analyse some features and results of thermal control of an opaque hinged ventilated facade system and translucent enclosing structures in the form of window systems of a capital construction project.

Method. Thermal imaging was used as a control for resolving issues of energy and resource conservation. The special importance of thermal control of translucent facade systems and non-translucent hinged ventilated facades of capital construction projects having various functional and operational purposes is highlighted.

Results. A detailed algorithm is presented for supporting a comprehensive diagnosis of the heat engineering state of building envelopes for various construction projects by analysing thermograms, using thermal monitoring methods, to take into consideration engineering systems, building materials and finished products, along with technologies of full-scale thermal imaging inspection of translucent building envelopes. The obtained thermograms are presented and analysed.

Conclusion. Current problems in the fields of energy efficiency and energy saving in the construction and energy industries are considered in the light of the latest technological developments. The proposed graph-analytical algorithm supporting a diagnosis of the heat engineering state of building envelopes based on the analysis of thermograms is the most comprehensive among known analogues and prototypes

Abstract. Aim. The possibility of obtaining the regressive part of the elastic (regressiveprogressive) characteristic under axial loading in the initial period is studied by applying an elastic rod having an initial curvature under vertical compressive load. The objective of the study is to determine the static characteristics of such a rod without taking the resistance forces into account.

Method. To solve the problem, the elliptic parameters method was used to make a comparison with a solution obtained using the finite element method in the ANSYS engineering simulation software.

Results. A technique was developed for assessing the strain state and displacements of a flexible rod with initial curvature in order to study the regression-progressive characteristic of various elastic systems having initial curvature for their effective use in determining oscillations.

Conclusion. The obtained technique can be used to determine the deformed state of an elastic flexible rod having initial curvature and displacement of the point of application of force. At the same time, by setting various initial parameters of the flexible rod in order to obtain a regressive-progressive characteristic, significant displacements can be obtained in the subcritical region when the axial load does not exceed the Euler force for this flexible rod

Abstract. Aim. An important direction in contemporary concrete science is aimed at the development of multicomponent systems using mineral powder fillers in a finely dispersed state to create strong and durable building composites. One of the most significant factors affecting the properties of multicomponent systems is the compatibility of its components. Efforts on the part of leading scientific institutes are aimed at replacing expensive and energy-intensive Portland cement with composite concrete products produced using mixed binders. In this context, the development of modern effective composites based on clinkerless alkaline binders becomes an urgent problem.

Methods. Studies into the compatibility of multicomponent cementing systems are based on a contemporary technological approach that contributes to the production of strong and durable cement stone, without the use of traditional Portland cement.

Results. Electron probe studies and X-ray phase analysis of concrete produced using a clinker-free alkaline activation binder showed that the studied multicomponent system contains a hydro-aluminosilicate zeolite phase of variable composition, as well as indicating the presence of calcite, quartz, albite feldspar, mica, zeolites and potassium feldspar.

Conclusion. The results of the studies confirm the compatibility of all components of the multicomponent system comprised of mineral powder, alkaline coater and surfactant. The proposed technological method can be used to produce strong and durable building composites with clinker-free technology avoiding the use of expensive and energy-intensive Portland cement. Acknowledgments. The work was performed as part of research on the implementation of scientific project No. 05.607.21.0320. “Development of technology for new building composites on clinker-free alkaline binders using substandard natural and secondary raw materials” which received support from the federal target program “Research and Development in Priority Directions for the Development of the Russian Science and Technology Complex for 2014-2020.” Unique identifier for the agreement RFMTFI60719X0320.