Abstract. Objective. To determine the most relevant way to improve the energy efficiency of the system for discharging liquefied natural gas (LNG) from large-capacity storage facilities.
Methods. The method of analysis of existing systems for LNG discharge from storage tanks was used to identify critical (emergency) elements of the system to be improved and possible options of improving structural elements.
Results. The operation of the system for discharging LNG from storage tanks was analysed and its main characteristics were described. Main problems associated with designing and building borehole pumps, as well as goals and tasks of designing new borehole pump structures were studied. The main types of LNG borehole pumps, their varieties, and types of drives were studied to choose the most optimal new option of improving pumps for systems for discharging LNG from storage tanks. Further, it will be necessary to calculate geometric parameters of the hydroturbine and operation modes of its wheel being in connection with the centrifugal pump wheel.
Conclusion. Experience of using storage facilities shows that LNG pumps are the most critical units significantly increasing production risks. Therefore, the LNG borehole pump design improvement was chosen as a method to increase the energy efficiency of the system for discharging LNG from large-capacity storage facilities. Based on the considered advantages and disadvantages of structural elements of the existing LNG borehole pump design, we chose the replacement of the electric pump drive with an alternative one as the most optimal improvement method.

Objective. The study is aimed at determining the dependence of the average error in calculating the epicenter coordinates of an earthquake on errors in measuring the velocities of seismic waves for various methods of seismic event localization. Error distribution investigation for the method for determining the earthquake hypocenter coordinates using the Cassinian oval.
Methods. The problem was solved using statistical methods: methods of frequency and regression analyzes, means comparison method, and uniform search method.
Results. A relationship between the accuracy of measuring the velocities of seismic waves when determining the coordinates of an earthquake epicenter were established for four different earthquake hypocenter coordinates calculation methods. A method for determining the earthquake hypocenter coordinates using the fourth-order figure of the Cassinian oval was proposed. The error distribution density of the Cassinian oval method was compared with the ones of other methods.
Conclusion. The results obtained make it possible to choose one or another method for calculating the hypocenter coordinates depending on the specific area in which a seismic event occurred and the locations of seismic sensors.

Objective. The purpose of the article is to analyse the existing methodology used to assess the efficiency of automated information security systems by studying open literature sources, international and industry standards of the Russian Federation on information security of automated systems, guidelines and orders of the Federal Service for Technical and Expert Control of Russia, as well as departmental orders, instructions and regulations on information security at informatization facilities of internal affairs bodies. The analysis results in identifying the advantages and disadvantages of the specified methodology, as well as the possibilities of its use when conducting a quantitative assessment of the efficiency of access control subsystems of information security systems at the informatization facilities of internal affairs bodies.
Methods. To achieve this goal, the method for system analysis of approaches used to assess the efficiency of information security tools and systems has been applied.
Results. The paper presents results of analysing the main approaches used to assess the efficiency of tools and systems for information security of automated systems. The paper determines the relationship between the efficiency indicator of access control subsystems of information security systems and the main disadvantage of their use in protected automated systems of internal affairs bodies. The paper substantiates main directions of improving the existing methodology, proposes methods and indicators for quantifying the efficiency of access control subsystems (including those modified on the basis of using new information and communication technologies) of information security systems in protected automated systems of internal affairs bodies.
Conclusion. The results obtained can be used to quantify the security level of existing automated systems and those being developed at informatization facilities of internal affairs bodies.

Objective. In recent decades, criteria for identifying potential areas have evolved hand in hand with technological tools such as geographic information systems (GIS). However, the criteria for the preservation of protected areas are often not taken into account, thus causing damage to environmental biodiversity that can become irreparable. This paper presents the way of optimizing the process of locating key terrain points by developing a hybrid algorithm for geospatial analysis in QGIS. The goal is to speed up computational time, which is a critical variable for the entire key point detection process, and to suggest potential areas that do not pose a threat to biodiversity.
Methods. The strategy used is based on two fundamental assumptions: identifying the tops of spatial objects (rivers) and analyzing the distances between spatial objects (rivers and adjacent territories). The tops extraction allows obtaining potential points, while the distance analysis allows selecting among them those points that are in the range acceptable for locating a dam, provided that the least possible damage to the biodiversity of the adjacent territory is caused. The algorithm was validated using the example of the hydrological network of Manicaragua, Cuba.
Results. The results were compared in terms of the calculation time used, the number of valid tops extracted, and the percentage reduction in the total number of areas. This comparison was made using one, two and three vector layers (.shp) with spatial objects representing strategic protected areas.
Conclusion. The results obtained show that the more representative the space data (.shp) used, the more effective the results obtained using the algorithm are in relation to environmental protection tasks. A reduction of up to 13% from originally detected key points has been achieved.

Objective. Development of automated balance flow-sheets in commodity and feedstock depots.
Methods. Methods for modelling balance flow-sheets of commodity and feedstock depots, taking into account petroleum products movement and shipping plans, were applied.
Results. Examples of automated balance flow-sheets of commodity and feedstock depots specific to refineries are given with the description of technological processes or oil product shipment processes. Rail, road, water, and pipelines shipment automation processes are shown. Operational and daily summaries of balance objects, such as a tank or a group of tanks (commodity group), are graphically shown. An example of an automated dispatch sheet formed on the basis of corresponding automated balance flow-sheets is given.
Conclusion. The implementation of automated flow-sheets for all significant production facilities at a refinery, in particular for commodity and feedstock depots, will ensure the visibility and transparency of information on balance objects, which is subsequently used to close a balance sheet for the enterprise as a whole.

Objective. The removal of asphaltene deposits at oil and gas facilities is one of the urgent and important problems and requires significant material and labor costs. It is possible to reduce costs by creating and implementing effective technical means, which requires an in-depth study of the processes of organic matter deposition at oil and gas facilities and their use as a secondary raw material.
Methods. This paper discusses modern views on the state of the problem of asphaltene deposits in oil shipping and storage equipment and possible ways to solve it. The paper provides an overview of various ways to clean shipping and storage objects from asphaltene deposits: chemical (adding additives, solvents), thermal (heating by special devices or injection of superheated steam during exploitation), mechanical (using scrapers and pistons), and refers, among other things, to scientific works on the use of ultrasound to accelerate the removal of deposits.
Results. The paper considers methods for removing deposits, as well as using the positive effect of the removed layer as a secondary energy source. A procedure for model calculation of the use of ultrasonic equipment to remove deposits has been developed. As a result, the deposit melting front velocity was determined depending on the duration of exposure.
Conclusion. Taking into account the positive world experience, the level of development of the ultrasonic method for removing asphaltene deposits in the oil and gas industry and the use of asphaltene deposits as a secondary raw material, this area needs further development. The widespread implementation of equipment and, from the standpoint of rational use of natural resources, the use of deposits as a secondary raw material will increase cost efficiency and equipment efficiency, and reduce environmental impact.

Objective. The goal of the study is to identify ways to improve energy efficiency by conducting a comprehensive analysis of engineering systems of a house, taking into account the existing model of energy supply and by monitoring the indicators of influence on the efficiency of engineering and technical equipment.
Methods. The main method is based on a survey of the level of energy efficiency of heating and hot water supply systems.
Results. The article discusses the concept of energy efficiency of a building, energy efficiency class, main utility systems of a residential building, indicators of influence on the state of systems, engineering component and ways to improve it. The article addresses issues related to a full analysis of existing systems in order to assess the implementation of necessary energy-saving measures, as well as their risks and benefits. The possibilities of controlling energy consumption and efficiency of works carried out due to the reconstruction of utility systems of the building have been determined. The results of the analysis of energy-efficient measures, and the feasibility of implementing each of them have been determined in order to identify optimal solutions.
Conclusion. Increasing the energy efficiency of building utility systems is one of the priority tasks for creating comfortable living conditions. The energy efficiency class of building utility systems is established according to the state of a system, takes into account all quality indicators for energy consumption, and the energy certificate fully shows the level of energy efficiency.

Objective. The article addresses the process of heat and mass transfer in outer envelope structure with internal heat insulation. To prevent condensate formation, it is proposed to use a ventilated air duct inside the wall structure.
Methods. The study was carried out using numerical simulation methods. Air movement in the duct was described by solving the Navier-Stokes equation in k-ε approximation. Condensate formation was analysed via joint resolution of heat conduction and diffusion equations. The problem of heat and mass transfer was addressed for a structure with internal heat insulation, behind the layer of which an air duct was located with air movement occurring due to natural or forced convection.
Results. As part of the work, it was shown that the use of an air duct significantly reduces the thermal resistance of the structure, and an increase in the airflow rate leads to a decrease in thermal resistance and the likelihood of condensate formation. A decrease in thermal resistance with an increase in air flow rate into interlayers occurs faster than an increase in the amount of air-entrained moisture.
Conclusion. Results of the work have shown that the use of an air duct throughout the entire period of operation of a building is not effective, but it is proposed to use this duct periodically in winter to dry the condensate.

Objective. One of the most effective ways to assess thermal protection of construction facilities of various applications is thermal control.
Methods. According to the national standard “Method for thermal imaging quality control of thermal insulation of enclosing structures” in force on the Russian Federation territory, the results of thermal imaging monitoring of capital and completed construction facilities are divided into qualitative and quantitative depending on set goals and objectives. Qualitative assessment involves computer processing and visual interpretation of thermograms using specialized software. Quantitative analysis of thermograms involves determining and numerically comparing parameters of reference areas and characteristics of defects detected in an object being under thermal control.
Results. The paper describes particular characteristics and results of qualitative and quantitative analysis of thermograms (thermal images) obtained via thermography of fragments of external enclosing structures of a completed construction facility—an apartment building. The paper analyses existing methods of a quantitative assessment of thermograms described in regulatory documents and methodological recommendations, and presents specific examples of their application.
Conclusion. Thermal imaging diagnostics makes it possible to qualitatively and quantitatively assess the level of thermal protection of the outer shell of an object under control by “decoding” thermograms and comparing calculated parameters with standard indicators.

Objective. The paper is aimed at clarifying the mechanism and kinetics of the processes leading to cement caking.
Methods. To determine phase composition, the following modern physical and chemical methods were used: XRF, derivatography and electron microscopy.
Results. The data obtained show that the “aging” of cements during their forced storage in humid air through the adsorption of water vapor, and then CO2, is associated with the processes of hydrolysis, hydration in surface layers of particles, is primarily relevant for the most reactive minerals of Portland cement clinker. The deepening of these processes also depends on the state of the corroded surface of minerals.
Conclusion. The work carried out makes it is possible to preliminarily outline storage conditions for freshly ground Portland cements (according to the kinetics of sorption – the storage duration, according to isotherms – the permissible relative humidity), at which the LOI value of commercial cement remains stable for the required minimum time.

Objective. In the case of a coupled supply of heat in a heat supply system, engineering structures act as a heat accumulator. Therefore, when calculating the premises cooling time in case of accidents in a heating network, it is necessary to take into account not only weather conditions, but also a decrease in the flow of heat from the heat supply system, since at low outside temperatures the heat loss in premises is greater than the heat supply, which will lead to the accumulation of moisture in materials of the structures.
Methods. To build a model of internal conditions in premises when the heat supply system operates in emergency mode, the humidity potential theory was applied, which allows calculating the humidity mode of engineering structures under various non-periodic exposures.
Results. A method for calculating moisture accumulation in outer walls of residential premises using the moisture potential theory is proposed.
Conclusion. The impact of moisture accumulation on heat accumulation in outer walls and the dynamics of internal air temperature in premises under emergency conditions of the heat supply system operation has been determined.

Objective. In most cases, when determining the stress-deformed state of three-layer structures, it is assumed that bearing layers obey the Kirchhoff-Love hypothesis, while a filler obey the Neit (vanderNeit), or “broken line”, hypothesis. But in many cases, the results of our research show that this is not always accurate.
Methods. It is proposed to solve the three-dimensional problem of determining the stress-deformed state of a three-layer structure using cubic functions of the law of aggregate deformation distribution along the normal line, obtained on the basis of the law of deformation compatibility at “filler – bearing layer” boundaries and the construction of boundary conditions in joint zones.
Results. Equilibrium equations of a three-layer beam obtained on the basis of this hypothesis are shown in Table 1. The given partial differential equations are of the 12th order and we transformed them into homogeneous equations of the 1st order to simplify the solution. This solution is implemented using the mathematical modelling software package Mаple 5.4.
Conclusion. The work of the filler in the direction of OX axis has a certain value, which affects the overall stress state of the three-layer structure (in existing hypotheses, it is zero).