CONTENTS of journal "THNP" 4•2020

DESIGN, CONSTRUCTION AND OPERATION OF GAS AND OIL PIPELINES AND STORAGES

HIERARCHICAL MULTISTAGE APPROACH IN BRANCHED PIPELINE OIL PRODUCT PUMPING PROBLEM (P. 5-13)
Nekrasov¹ Ivan V., Zhagfarov² Ildar F., Kondratyev³ Andrey D.
¹ V.A. Trapeznikov Management Institute of the RAS, 117997, Moscow, Russia
ORCID: https://orcid.org/0000-0003-0520-7222, E-mail: Адрес электронной почты защищен от спам-ботов. Для просмотра адреса в вашем браузере должен быть включен Javascript.
² Industrial Analytics Center LLC, 108811, Moscow, Russia
ORCID: https://orcid.org/0000-0002-2606-6214, E-mail: Адрес электронной почты защищен от спам-ботов. Для просмотра адреса в вашем браузере должен быть включен Javascript.
³ Tsifra LLC, 119311, Moscow, Russia
ORCID: https://orcid.org/0000-0003-0192-5032, E-mail: Адрес электронной почты защищен от спам-ботов. Для просмотра адреса в вашем браузере должен быть включен Javascript.
ABSTRACT
This paper belongs to authors’ series of publications in sphere of “Informational Management of Large-Scale Technical Systems”. The control objects considered in this research are branched networks of gas, oil and oil products pipelines. Authors focus on the pumping process scheduling procedures that are processed by the top level informational control system. According to the general approach of hierarchical management the scheduling process is split into three consequent optimization procedures: top-level volumetric planning that gives feasible preliminary timeframes for each pipeline run (corresponds to each separate product batch); pipeline-level calendar scheduling that generates input pumping tasks for each pipeline section (each task contains product volume and pumping time); section-level operating scheduling that gives an exact timetable how the pumping tasks are carried out (timetable is an aggregation of time-marked instructions which regimes of the section to enable and when). All three optimization procedures are formulated either as the standard linear programming problem set up or as the simultaneous linear algebraic equations system. Utilizing these linear models makes it easy to run all the computations in an average IT-infrastructure available for any enterprise at present. Considered planning and scheduling models are adoptable for gas pumping networks with minor changes of physical problem setting.
KEYWORDS: oil and oil products pipeline, oil and oil products pumping, industrial enterprise management, production scheduling, pipeline timetable, hierarchical systems, linear programming, optimization.
For citation: Nekrasov I.V., Zhagfarov I.F., Kondratyev A.D. HIERARCHICAL MULTISTAGE APPROACH IN BRANCHED PIPELINE OIL PRODUCT PUMPING PROBLEM. Transport and Storage of Oil Products and Hydrocarbons. 2020, no. 4, pp. 5-13.
DOI:10.24411/0131-4270-2020-10401

DEVELOPMENT OF METHODIC FOR DETERMINATION OF SOIL CORROSIVITY LEVEL IN ZONE OF PIPELINE CONSTRUCTION (P. 14-17)
Nasirov Habib M.
National Aerocosmic Agency, AZ 1141, Baku, Azerbaijan Republic
ORCID: https://orcid.org/0000-0002-2548-1264, E-mail: Адрес электронной почты защищен от спам-ботов. Для просмотра адреса в вашем браузере должен быть включен Javascript.
ABSTRACT
The paper is devoted to development of new methodic for determination of soil corrosivity level. The questions concerning the pipeline corrosivity occurred by effect of temperature, ph, soil resistivity and duration of effect of these factors are researched. On the basis of results of theoretical and experimental researches the concrete formula for corrosivity calculation losses depending of above regime parameters is obtained. It is shown that in order to reach the minimum value of time averaged corrosivity losses the soil temperature should decrease inversely concerning current time.
KEYWORDS: pipeline; corrosion; soil conductance; optimization; Penners method.
For citation: Nasirov H.M. DEVELOPMENT OF METHODIC FOR DETERMINATION OF SOIL CORROSIVITY LEVEL IN ZONE OF PIPELINE CONSTRUCTION. Transport and Storage of Oil Products and Hydrocarbons. 2020, no. 4, pp. 14-17.
DOI:10.24411/0131-4270-2020-10402

COMPARATIVE ANALYSIS OF THE EFFECTIVENESS OF ANTI-TURBULENCE ADDITIVES IN LABORATORY CONDITIONS (P. 18-23)
Muratova¹ Vera I., Valeev¹ Anvar R., Yang² Chen, JiaQiang² Jing, Ismakov¹ Rustem A.
¹ Ufa State Petroleum Technological University, 450062, Ufa, Russia
ORCID: https://orcid.org/0000-0001-9243-9878, E-mail: Адрес электронной почты защищен от спам-ботов. Для просмотра адреса в вашем браузере должен быть включен Javascript.
ORCID: https://orcid.org/0000-0001-7197-605X, E-mail: Адрес электронной почты защищен от спам-ботов. Для просмотра адреса в вашем браузере должен быть включен Javascript.
ORCID: https://orcid.org/0000-0002-7544-922X, E-mail: Адрес электронной почты защищен от спам-ботов. Для просмотра адреса в вашем браузере должен быть включен Javascript.
² Southwest Petroleum University, 610500, Chengdu, China
ORCID: https://orcid.org/0000-0001-9566-3488, E-mail: Адрес электронной почты защищен от спам-ботов. Для просмотра адреса в вашем браузере должен быть включен Javascript.
ORCID: https://orcid.org/0000-0003-4219-0829, E-mail: Адрес электронной почты защищен от спам-ботов. Для просмотра адреса в вашем браузере должен быть включен Javascript.
ABSTRACT
The paper proposes methodology for providing the experiments and processing of obtained results for determining the efficiency of Necadd-447, MFLOWTREAT, FLO XL, FLO MXA additives via disk turborheometer in case of their application in oil and oil product pipelines. Positive value of hydraulic efficiency is obtained in the range of Reynolds number of 140-240 thousand for all the studied additives. With an increase in the Reynolds number hydraulic efficiency also increases and reaches the maximum values at 600-700 thousand. With an increase in the additive concentration to 20 – 40 ppm there is an increase in hydraulic efficiency. A further increase in the concentration, on the contrary, leads to a certain decrease in the effectiveness.
KEYWORDS: additives, disk turborheometer, hydraulic efficiency, laboratory tests, diesel fuel.
For citation: Muratova V.I., Valeev A.R., Chen Yang, Jing JiaQiang, Ismakov R.A. COMPARATIVE ANALYSIS OF THE EFFECTIVENESS OF ANTI-TURBULENCE ADDITIVES IN LABORATORY CONDITIONS. Transport and Storage of Oil Products and Hydrocarbons. 2020, no. 4, pp. 18-23.
DOI:10.24411/0131-4270-2020-10403
Acknowledgments: The reported study was funded by RFBR and NSFC according to the research project № 19-58-53009.

IMPLEMENTATION OF DIGITAL TECHNOLOGIES IN THE OIL AND GAS INDUSTRY OF RUSSIA (P. 24-28)
Khasanov¹ Ilnur I., Rakhmatullina¹ Yuliya A., Shakirov² Ruslan A.,
¹ Ufa State Petroleum Technological University,
450062, Ufa, Russia
² Branch of PJSC ANK Bashneft Bashneft-Novoil
450037, Ufa, Russia
ABSTRACT
The research work presents the rationale for the implementation of new technological solutions connected with digitalization for the oil and gas industry. Key actions for the digitalization of certain industries such as exploration and production, refining and transportation of oil - are indicated. The main examples of innovative digital technologies in the field of oil transportation and storage are considered.
KEYWORDS: digital technologies, innovation, oil, fuel and energy complex, modernization.
For citation: Khasanov I.I., Rakhmatullina YU.A., Shakirov R.A. IMPLEMENTATION OF DIGITAL TECHNOLOGIES IN THE OIL AND GAS INDUSTRY OF RUSSIA. Transport and Storage of Oil Products and Hydrocarbons. 2020, no. 4, pp. 24-28.
DOI:10.24411/0131-4270-2020-10404

FRONT AND TAIL OF THE WAVE FROM THE LEAK IN AN OIL PIPELINE (P. 29-33)
Alperovich Ilya V.
Wavecontrol LLC, 119454, Moscow, Russia
ORCID: https://orcid.org/0000-0002-6380-2727, E-mail: Адрес электронной почты защищен от спам-ботов. Для просмотра адреса в вашем браузере должен быть включен Javascript.
ABSTRACT
Among the main methods of detecting leaks from oil pipelines is the analysis of the pressure drop waves resulting from the leak. The wave of pressure drop is characterized by its front and tail (part of the pressure trend behind the front).Comparing the waves from real leaks with the waves calculated according to the classical mathematical model, one can notice certain differences. In particular, the height of the front and the slope of the tail with the mileage of the real wave can decrease faster than in the model. In addition, the tilt of a real tail can be fickle, as opposed to the tilt of a theoretical tail. Improving the coincidence of the theory with the fact is proposed by means formally adjusting the dependence of the disturbance of the friction force on the speed of the flow. Successful example of this approach has been given.
KEYWORDS: oil pipeline, leak, mathematical model, pressure drop wave, front of wave, tail of wave.
For citation: Alperovich I.V. FRONT AND TAIL OF THE WAVE FROM THE LEAK IN AN OIL PIPELINE. Transport and Storage of Oil Products and Hydrocarbons. 2020, no.5, pp. 29-33.
DOI:10.24411/0131-4270-2020-10405

ON THE FRACTAL PROPERTIES OF BALLAST DEPOSITION DURING OIL BLENDING (P. 34-36)
Adygezalova Mekhpara B.
Azerbaijan State Oil and Industry University, AZ 1010, Baku, Azerbaidjan Republic
ORCID: https://orcid.org/0000-0002-0966-2946, E-mail: Адрес электронной почты защищен от спам-ботов. Для просмотра адреса в вашем браузере должен быть включен Javascript.
ABSTRACT
The article is devoted to the study of ballast deposition processes in oil mixtures using the example of mixing two different crude oils of Azerbaijan. It was found that in various ratios of the mixed oils non-additive properties of the main indicators of the mixture are manifested. Using the two crude oils of Azerbaijan as an example, it was shown that the bulk of ballasts (resins, asphaltenes, paraffins, water and solids) is precipitated within 7-8 hours, after which the deposition process will slow down and almost complete. The results of processing the kinetics of the deposition of ballasts according to Hausdorff showed that the deposition process during the mixing of oils has a pronounced fractal character.
KEYWORDS: miscible oils, transport, ballasts, deposition, physicochemical properties, pipeline transport, precipitation, non-additivity, model, asphaltene, resin, paraffin.
For citation: Adygezalova M.B. ON THE FRACTAL PROPERTIES OF BALLAST DEPOSITION DURING OIL BLENDING. Transport and Storage of Oil Products and Hydrocarbons. 2020, no. 4, pp. 34-36.
DOI:10.24411/0131-4270-2020-10406

STUDY OF THIXOTROPIC PROPERTY OF MODEL HIGH-PARAFFINIC OIL IN LABORATORY CONDITIONS (P. 37-41)
Pashaeva Saida M.
Azerbaijan State  Oil and Industry University, AZ 1010, Baku, Azerbaidjan Republic
ORCID: https://orcid.org/0000-0003-0138-8134, E-mail: Адрес электронной почты защищен от спам-ботов. Для просмотра адреса в вашем браузере должен быть включен Javascript.
ABSTRACT
For the first time, the thixotropic property of a model high-paraffinic oil at different temperatures on a rotary viscometer of the brand "Reotest-2" in laboratory conditions was investigated. During the experiments, both unadditioned model oil samples and samples with the addition of a depressor additive "Difron-4201" with different concentrations (300. 500, 700, 900, 1100 g/t) were used. It was found that at low temperatures in high-paraffin oil, first with a gradual increase and then a decrease in the velocity gradient, the obtained flow curves do not coincide and form a hysteresis loop. In oil samples with added depressant additives, hysteresis loop area decreases, and the best effect is observed at a concentration of 900 g/t. Using a graph of the dependence of shear stress on temperature for samples of model high-paraffin oil without additives, as well as with added additives, the nonequilibrium coefficients were calculated. The results show that with an increase in shear rate, the nonequilibrium coefficient decreases. Calculation of the nonequilibrium coefficient for samples of model high-paraffin oil with the addition of the “Difron-4201”depressant additive with different concentrations made it possible to determine the optimal consumption rate of 900 g/t.
KEYWORDS: model high-paraffin oil, thixotropy property, “Difron-4201”, non-equilibrium coefficient, hysteresis loop, optimal concentration.
For citation: Pashaeva S.M. STUDY OF THIXOTROPIC PROPERTY OF MODEL HIGH-PARAFFINIC OIL IN LABORATORY CONDITIONS. Transport and Storage of Oil Products and Hydrocarbons. 2020, no. 4, pp. 37-41.
DOI:10.24411/0131-4270-2020-10407

CONSTRUCTION AND REPAIR OF GAS AND OIL PIPELINES AND GAS AND OIL STORAGE FACILITIES
 
INFLUENCE OF FROST BOIL ON THE LINEAR PART OF MAIN PIPELINES (P. 42-48)
Gulin Denis A., Fayzullina Elvira V., Sharipova Elvina I.
Ufa State Petroleum Technological University,
450062, Ufa, Russia
ORCID: https://orcid.org/0000-0002-3145-748X, E-mail: Адрес электронной почты защищен от спам-ботов. Для просмотра адреса в вашем браузере должен быть включен Javascript.
ORCID: https://orcid.org/0000-0002-9756-7403, E-mail: Адрес электронной почты защищен от спам-ботов. Для просмотра адреса в вашем браузере должен быть включен Javascript.
ORCID: https://orcid.org/0000-0002-5796-6514, E-mail: Адрес электронной почты защищен от спам-ботов. Для просмотра адреса в вашем браузере должен быть включен Javascript.
ABSTRACT
The authors analyzed the existing calculation methods for determining the stress-strain state of a pipeline laid on heaving soils; studied the dependences of determining the normal forces of frost heaving; based on the research, identified the shortcomings of existing ones and identified areas for their improvement.
KEYWORDS: permafrost soils, the swelling soil, normal forces of frost heaving, underground pipeline.
For citation: Gulin D.A., Fayzullina E.V., Sharipova E.I. INFLUENCE OF FROST BOIL ON THE LINEAR PART OF MAIN PIPELINES. Transport and Storage of Oil Products and Hydrocarbons. 2020, no. 4, pp. 42-48.
DOI:10.24411/0131-4270-2020-10408

METHOD FOR PREDICTING TRACTION FORCES IN THE CONSTRUCTION OF PIPELINE CROSSINGS BY HORIZONTAL DIRECTIONAL DRILLING (P. 49-56)
Ovchinnikov Roman D., Khasanov Rustyam R.
Ufa State Petroleum Technological University, 450062, Ufa, Russia
ORCID: https://orcid.org/0000-0002-4737-7185,  E-mail: Адрес электронной почты защищен от спам-ботов. Для просмотра адреса в вашем браузере должен быть включен Javascript.
ORCID: https://orcid.org/0000-0002-6244-7532,  E-mail: Адрес электронной почты защищен от спам-ботов. Для просмотра адреса в вашем браузере должен быть включен Javascript.
ABSTRACT
The aim of the work is to improve the methodology for determining the pulling force in the design of pipeline crossings. The authors performed an analysis of the three existing methods for calculating the pulling force of a pipeline during the construction of crossings by tilt directional drilling: the method of Giprotruboprovod JSC, the methodology of the Canadian University of Waterloo, the methodology according to SP 42-101-2003. As a result of comparing the results of calculations by existing methods with the actual values of pulling efforts, the advantages and disadvantages of the methods that affect the final result of the calculation were identified. The authors proposed their own methodology for calculating the pulling force of the pipeline. When comparing the calculation results with the actual values of the efforts of already constructed transitions, the average calculation error by the proposed method turned out to be the most accurate among existing methods and amounted to 16%.
KEYWORDS: horizontal directional drilling, tilt directional drilling, pipeline, pulling force, modeling.
For citation: Ovchinnikov R.D., Khasanov R.R. METHOD FOR PREDICTING TRACTION FORCES IN THE CONSTRUCTION OF PIPELINE CROSSINGS BY HORIZONTAL DIRECTIONAL DRILLING. Transport and Storage of Oil Products and Hydrocarbons. 2020, no. 4, pp. 49-56.
DOI:10.24411/0131-4270-2020-10409

INCREASING THE CARRYING ABILITY OF INSULATION COATINGS OF UNDERGROUND PIPELINES (P. 57-60)
Nikiforov Dmitriy A., Abdullin Nail V.
Ufa State Petroleum Technological University, 450062, Ufa, Russia
ORCID: https://orcid.org/0000-0002-1721-3622, E-mail: Адрес электронной почты защищен от спам-ботов. Для просмотра адреса в вашем браузере должен быть включен Javascript.
ORCID: https://orcid.org/0000-0002-1721-3622, E-mail: Адрес электронной почты защищен от спам-ботов. Для просмотра адреса в вашем браузере должен быть включен Javascript.
ABSTRACT
The carrying ability of insulating coatings is reduced due to the occurrence of tangential and normal stresses, as well as internal thermoelastic stresses due to differences in pumping pressure and the temperature of the transported medium. The objectives of the work: to study the causes and the process of occurrence of mechanical stresses in insulating coatings of trunk pipelines; to analyze the regulatory and technical documentation and scientific papers on this topic; to work out options to reduce the effect of mechanical stresses on the insulation coating.
KEYWORDS: main pipeline, insulation coatings, mechanical stresses, tangential stresses, thermoelastic stresses.
For citation: Nikiforov D.A., Abdullin N.V. INCREASING THE CARRYING ABILITY OF INSULATION COATINGS OF UNDERGROUND PIPELINES. Transport and Storage of Oil Products and Hydrocarbons. 2020, no. 4, pp. 57-60.
DOI:10.24411/0131-4270-2020-10410

TESTING PROCEDURE FOR STEEL SPRING BEARINGS SAFETY VALVES WITHOUT DISMANTLING (P. 61-64)
Abdullin Nail V., Varfolomeev Roman O.
Ufa State Petroleum Technological University, 450062, Ufa, Russia
ORCID: https://orcid.org/0000-0002-1721-3622, E-mail: Адрес электронной почты защищен от спам-ботов. Для просмотра адреса в вашем браузере должен быть включен Javascript.
ORCID: https://orcid.org/0000-0002-1721-3622,  E-mail: Адрес электронной почты защищен от спам-ботов. Для просмотра адреса в вашем браузере должен быть включен Javascript.
ABSTRACT
Today, there are common methods for testing steel spring safety valves, but with the development of pipeline transport, there is a need to optimize technological processes, which can also be achieved by reducing labor costs and time for testing safety equipment. The article presents the results of theoretical research on the application of the method of testing steel spring safety valves(SPPC) without dismantling the equipment. The essence of this test method and its advantages are given.
KEYWORDS: safety equipment of the oil pumping station, steel spring valves, SPPC.
For citation: Abdullin N.V., Varfolomeev R.O.. TESTING PROCEDURE FOR STEEL SPRING BEARINGS SAFETY VALVES WITHOUT DISMANTLING. Transport and Storage of Oil Products and Hydrocarbons. 2020, no. 4, pp. 61-64.
DOI:10.24411/0131-4270-2020-10411

FIELD PIPELINE SYSTEMS

EFFECTIVENESS OF APPLYING PIPELINE LEAKS AND CUTAWAYS DETECTION METHODS ANALYSIS (P. 65-68)
Gurnitskaya¹ Elena YU., Zubairov¹,² Timur A.
¹ Ufa State Petroleum Technological University, 450062, Ufa, Russia
ORCID: https://orcid.org/0000-0002-2026-2150, E-mail: Адрес электронной почты защищен от спам-ботов. Для просмотра адреса в вашем браузере должен быть включен Javascript.
ORCID: https://orcid.org/0000-0002-1059-7061, E-mail: Адрес электронной почты защищен от спам-ботов. Для просмотра адреса в вашем браузере должен быть включен Javascript.
² RN-BashNIPIneft LLC
ORCID: https://orcid.org/0000-0002-1059-7061, E-mail: Адрес электронной почты защищен от спам-ботов. Для просмотра адреса в вашем браузере должен быть включен Javascript.
ABSTRACT
The analysis and grouping of the main methods, mechanisms and approaches used to detect and localize leaks and tie-ins in the pipeline have been conducted. A comparison analysis for leaks and cutaways detection methods and approaches has been given, their advantages and disadvantages have been highlighted. The application of each proposed method has been evaluated in terms of their unique features and further promising direction of development.
KEYWORDS: leaks, insets, effectiveness of applying methods analysis, detection methods, applicability limits.
For citation: Gurnitskaya E.YU., Zubairov T.A. EFFECTIVENESS OF APPLYING PIPELINE LEAKS AND CUTAWAYS DETECTION METHODS ANALYSIS. Transport and Storage of Oil Products and Hydrocarbons. 2020, no. 4, pp. 65-68.
DOI:10.24411/0131-4270-2020-10412

DRILLING AND DEVELOPMENT TECHNOLOGIES

INVESTIGATION OF THE INFLUENCE OF OXIDIZED HUMATES ON THE PARAMETERS OF DRILLING FLUIDS (P. 69-72)
Likhacheva Natalya A., Zakharova Elena A.
Branch of the Ufa State Petroleum Technical University in Salavat, 453200, Salavat, Russia
ORCID: https://orcid.org/0000-0001-6328-1215, E-mail: Адрес электронной почты защищен от спам-ботов. Для просмотра адреса в вашем браузере должен быть включен Javascript.
ORCID: https://orcid.org/0000-0001-9305-3061, E-mail: Адрес электронной почты защищен от спам-ботов. Для просмотра адреса в вашем браузере должен быть включен Javascript.
ABSTRACT
The success of creating a long-term facility for extracting oil from the earth's interior depends largely on the drilling fluids used in the construction of wells. The composition and properties of the drilling mud should ensure the prevention of most of the possible complications in these conditions, while the reservoir properties of productive formations should remain unchanged. Minimizing the environmental impact of the drilling process is also a very important part of drilling operations in order to comply with environmental regulations that have become stricter worldwide. This article presents the results of experimental studies on the ability of oxidized humic substances of brown coals to influence the structural and mechanical properties of clay drilling fluids. Studies have shown that oxidized humates are promising reagents that reduce the viscosity of clay washing liquids, surpassing native brown-coal humic substances in this indicator.
KEYWORDS: clay drilling mud, brown coal, humic substances, viscosity, static shear stress, filtration index, rheological properties, oxidation, viscosity reducing agent.
For citation: Likhacheva N.A., Zakharova E.A. INVESTIGATION OF THE INFLUENCE OF OXIDIZED HUMATES ON THE PARAMETERS OF DRILLING FLUIDS. Transport and Storage of Oil Products and Hydrocarbons. 2020, no. 4, pp. 69-72.
DOI:10.24411/0131-4270-2020-10413

LABOUR ECONOMICS

FRAMEWORK OF LABOR STANDARDS OF INTERPRISE: OUTLINES FOR DEVELOPMENT (P. 73-80)
Bakhtizina Aliya R., Vorontsov Sergey А., Kesaev Soslan A., Malinin Sergey V.
Transneft R&D, LLC, 117186, Moscow, Russia
ORCID: https://orcid.org/0000-0002-2081-4090, E-mail: Адрес электронной почты защищен от спам-ботов. Для просмотра адреса в вашем браузере должен быть включен Javascript.
ORCID: https://orcid.org/0000-0003-1535-3020, E-mail: Адрес электронной почты защищен от спам-ботов. Для просмотра адреса в вашем браузере должен быть включен Javascript.
ORCID: https://orcid.org/0000-0001-5693-4599, E-mail: Адрес электронной почты защищен от спам-ботов. Для просмотра адреса в вашем браузере должен быть включен Javascript.
ORCID: https://orcid.org/0000-0002-1887-780Х, E-mail: Адрес электронной почты защищен от спам-ботов. Для просмотра адреса в вашем браузере должен быть включен Javascript.
ABSTRACT
The article deals with one of the urgent problems in the framework of labor standards, which is providing enterprises with updated regulations, analyses the causes and consequences of obsolescence of the framework of labor standards. The authors study best practice in developing in-house policies and procedures, examine the list of requirements for regulations, a number of requirements and methodological approaches to the organization and conduct of normative and research work at the enterprise. Proposals are made to address the issue of forming updated in-house policies and procedures concerning employment relationship.
KEYWORDS: performance standards system, normative and research work, framework of labor standards, organizational and technical conditions.
For citation: Bakhtizina A.R., Vorontsov S.А., Kesaev S.A., Malinin S.V. FRAMEWORK OF LABOR STANDARDS OF INTERPRISE: OUTLINES FOR DEVELOPMENT. Transport and Storage of Oil Products and Hydrocarbons. 2020, no. 4, pp. 73-80.
DOI:10.24411/0131-4270-2020-10414