Ректорат УДУНТ

Permanent URI for this collection

https://crust.ust.edu.ua/handle/123456789/19312

ENG: Rectorate of the USUST

Browse

Now showing 1 - 20 of 74

Didactic Aspects of Distance Learning in the Conditions of Pandemic and Martial Law
(Dnipropetrovsk State University of Internal Affairs, Dnipro, Ukraine, 2022) Galushko, Olena; Kovalenko-Marchenkova, Yevheniia; Chistyakov, Volodymyr G.
ENG: The article deals with the topical issues of improving the effectiveness of the educational process in higher educational institutions in the conditions of a pandemic and martial law. The evolution of distance learning is considered. Peculiarities of the remote form of education, which functions on the basis of modern psychological and pedagogical and information and communication technologies, have been studied. The peculiarities of the organization of the educational process in higher educational institutions in the context of the pandemic and martial law were analyzed, in particular didactic aspects of the educational process in conditions of danger and increased stress. Special attention is paid to the psychological state of students and ways of reducing stress and activating their attention on the educational process, taking into account the types of information perception (audio, visual, kinesthetic, digital). Ways to improve the distance learning process in the conditions of a pandemic and martial law are proposed.
Rheological Properties of Polymer-Polymer Mixtures on Corn Starch Base
(MM Publishing s.r.o., Praha, Czechia, 2022) Rimar, Miroslav; Tretyakoff, Artem; Sukhyy, Kostyantyn M.; Yeromin, Oleksandr O.; Kulikov, Andrii; Fedak, Marcel; Belyanovskaya, Elena; Shunkin, Ihnat; Gupalo, Olena V.; Krenicky, Tibor
ENG: The prospects for the use of polymer-polymer mixtures based on corn starch as alternative thermoplastic materials to polyolefins are considered. Rheological curves have been obtained, which confirm the possibility of processing such mixtures on standard equipment into products. It is shown that the starch content in polymer-polymer mixtures can reach 90 mass percent. Compared to existing biodegradable polymers, plasticized starch-based material is in no way inferior to them in terms of processability. Studies of the mechanical properties of polymer-polymer mixtures based on corn starch have been carried out. The data obtained indicate the possibility of using the developed composites as packaging materials, as well as alternative materials to known bioplastics and synthetic polymers.
Selection Criteria of Working Pairs Adsorbent – Adsorbate for Thermal Energy Transformers
(MM Science Journal, Czech Republic, 2022) Rimar, Miroslav; Sukhyy, Kostyantyn M.; Belyanovskaya, Elena; Yeromin, Oleksandr O.; Prokopenko, Elena M.; Kulikov, Andrii; Fedak, Marcel; Frolova, Lilia; Pustovoy, Grigoriy; Kulikova, Olha; Savko, Vitalii
ENG: In the manuscript the main factors that affect the thermal mass of open and closed types of heat storage devices are shown. Also, the main requirements for adsorption modules are given. The calculation procedure has been refined, which includes the determination of heat load, heat of adsorption, adsorbent mass, as well as integral, structural, and specific thermal mass. The specific thermal masses of adsorption heat-accumulating modules of open and closed types were evaluated. The main factors affecting their value are analysed. It is shown that the specific thermal mass of the adsorption heat storage module increases significantly due to the adsorption of water during the discharge of the device. It is shown that it reaches its maximum values at the end of the discharge stage, when the maximum values of adsorption in the cycle are reached. The influence of the design of the heat storage module on the value of the specific thermal mass has been confirmed. It is shown that the maximum values of these changes correspond to the composites containing 80% salt and 20% silica gel, due to the maximum values of the limiting adsorption and the heat of adsorption, which contributes to the lower values of the adsorbent mass, which is required to cover the thermal load. Specific thermal masses of adsorption modules based on "silica gel – sodium sulphate" and "silica gel - sodium acetate" composites are compared. The composition of the composite is 80% sodium sulphate and 20% silica gel, which corresponds to the minimum dimensions of the adsorption module, and therefore the maximum value of the specific thermal mass.
Design of Proactive Management System for Residential Buildings by Using Smart Equipment
(TECHNOLOGY CENTER PC, Kharkiv, 2023) Savytskyi, Mykola V.; Shekhorkina, Svitlana; Bordun, Maryna; Babenko, Maryna; Tsyhankova, Svitlana; Spyrydonenkov, Vitalii; Savytskyi, Oleksandr M.; Rabenseifer, Roman
ENG: This study's object is an energy efficiency of residential sector. The work is aimed at solving the task to improve the energy efficiency of the housing sector by devising technical solutions for monitoring and managing energy consumption and microclimate parameters of buildings. The proposed proactive management system for residential buildings consists of multi-sensors measuring CO2, temperature and humidity, smart meters of heat and electricity consumption, and smart plugs. The equipment is combined into single system through an integration controller with remote user access through an interactive web interface. A feature of the technical solution is the ability to collect, process, visualize, and archive data on the consumption of energy, as well as on the key parameters of the microclimate of residential premises. The advantages of the system are its flexibility due to the possibility of integrating additional devices during operation, as well as the use of standard communication protocols, which enables the interchangeability of component elements. The implementation and testing were carried out under the conditions of a real pilot site. The use of the system in practice confirmed the efficiency and stability of the operation, making it possible to obtain data on the parameters of energy consumption and microclimate and devising recommendations for reducing energy consumption at the pilot site. It was established that the microclimate meets the requirements of the standards (air temperature is about 22 °С while relative humidity does not exceed 60 %). Decrease in energy consumption can be achieved by reducing the temperature of the heat carrier in the absence of residents, as well as by considering the influence of weather conditions. During periods of residents’ activity, an excess of the permissible level of CO2 was recorded, therefore, automatic ventilation systems should be provided in the apartments.
Вплив стеаринової кислоти на властивості деревинно-полімерних композитів
(ДВНЗ “Український державний хіміко-технологічний університет”, Дніпро, 2023) Криволапов, Д. С.; Сухий, Костянтин Михайлович; Баштаник, П. І.; Третьяков, А. О.; Безрукавий, В. О.
UKR: Досліджено вплив стеаринової кислоти на технологічні, фізико-механічні та експлуатаційні властивості композитів на основі вторинного поліетилену низького тиску, наповненого деревинним борошном. Показано, що введення до деревинно-полімерного композиту до 1,1 мас. % стеаринової кислоти покращує технологічні параметри екструзії: зменшується крутний момент головного приводу екструзійного обладнання і збільшується продуктивність. При вмісті стеаринової кислоти в композиті 0,8-1,25 мас. % спостерігається зростання фізико-механічних показників композиту: збільшується міцність при вигині на 20 % (до 51,3 МПа) та ударна в'язкість за Шарпі на зразках з надрізом на 37 % (до 11,9 кДж/м2), а також зменшуються коефіцієнт лінійного термічного розширення та водопоглинання.
Сучасне уявлення про перебіг процесів деструкції поліетилентерефталату
(Дніпровський національний університет імені Олеся Гончара, Дніпро, 2023) Черваков, Денис О.; Сухий, Костянтин Михайлович; Черваков, Олег В.; Свердліковська, Ольга С.
UKR: У даній роботі, наведена інформація щодо сучасних уявлень про перебіг процесів деструкції поліетилентерефталату. Представлено загальні уявлення про механізми гідролітичної, термічної, термоокислювальної, термомеханічної та фотодеструкції поліетилентерефталату. Аналізуючи достатньо широкий ряд джерел літератури, встановлено, що деструкція поліетилентерефталату під впливом вологи, температури та навантажень зсуву, відбувається за декількома механізмами та має автокаталітичний характер. В ході гідролітичної деструкції поліетилентерефталату утворюються його полімерні та/або олігомерні похідні з гідроксильними, карбоксильними та вінілестерними групами, етилен, ацетальдегіди і циклічні сполуки.
Щільноспічена карбідокремнієва кераміка на склокристалічній зв’язці кордієритового складу
(ДВНЗ “Український державний хіміко-технологічний університет”, Дніпро, 2023) Положай, С. Г.; Зайчук, Олександр Вікторович; Сухий, Костянтин Михайлович; Положай, А. Г.
UKR: Висока щільність карбідокремнієвої кераміки є обов’язковою умовою для отримання матеріалів з високою міцністю. Перспективною технологією виготовлення таких матеріалів при порівняно невисоких температурах є використання склокристалічних зв'язок. В статті наведені результати досліджень керамічних матеріалів на основі карбіду кремнію з використанням як склозв'язки скла в псевдопотрійній системі MgO-Al2O3-SiO2. Склад скла відповідає потрійній евтектиці з температурою 1365 оС, яка знаходиться на стику полів первинної кристалізації, де однією з фаз є кордієрит. Визначено, що для одержання щільноспеченої кераміки необхідно проводити механоактивацію компонентів сировинної суміші. При цьому найбільш раціональне співвідношення між SiC наповнювачем і склозв’язкою, що забезпечує максимальний показник механічної міцності на стискскання (до 700 МПа), становить 60:40. Встановлено, що кристалізація склозв’язки має визначальне значення для визначення температури формування щільних карбідокремнієвих матеріалів. Ущільнення відбувається за рахунок руху під впливом теплових коливань дисперсних часток карбіду кремнію в розм'якшеному склорозплаві. Подальший процес дрібнодисперсної кристалізації склозв’язки при охолодженні під час випалу забезпечує зміцнення структури синтезованих матеріалів. Запропонований комплексний підхід до інтенсифікації процесу спікання є перспективним для одержання міцної карбідкремнієвої кераміки з низькими температурами синтезу (до 1600 оС). Достатньо високи показники міцності дослідної кераміки забезпечать її конкурентоспроможність щодо традиційних матеріалів, в тому числі тих, що застосовуються як зносо- та ударостійкі.
A Facile Two-Step PVP-Assisted Deposition of Co-Activated Nanosized Nickel Hydroxide Directly on a Substrate for Large-Scale Production of Supercapacitor Electrodes
(MDPI, 2023) Kotok, Valerii; Ondrejka, Peter; Mikolášek, Miroslav; Sojková, Michaela; Novák, Patrik; Gregor, Maroš; Kovalenko, Vadym; Sukhyy, Kostyantyn M.
ENG: The self-decomposition reaction of the nickel ammonia complex was used for the nickel hydroxide formation on the nickel foam with further modification in several ways. The addition of polyvinyl pyrrolidone (PVP) and the electrochemical or chemical activation with cobalt hydroxide was used to modify the formation method. In all cases, structures with Ni(OH)2 nanoflakes were formed. It was found that the flower-like particles of Co(OH)2 were precipitated during chemical activation among the nanoflakes. It was shown that the presence of PVP during the nickel ammonia complex decomposition suppressed the highly branched particles. The absence of the highly branched particles increased the capacitive properties of the formed electrode at high current densities. The highest capacitance in 1408 F/g at 1 A/g was shown for the sample precipitated with the PVP presence and the further chemical activation by cobalt.
Vibration Characteristics and Dynamic Control of Vacuum Treatment
(National Metallurgical Academy of Ukraine, Ukrainian State University of Science and Technologies, Dnipro, 2023) Velychko, A. G.; Sukhyi, Kostyantyn M.; Jiang, Zhouhua
ENG: Vibration characteristics of vacuum treatment at industrial steel vacuumisation units are studied. The amplitudefrequency spectrum and the main sources of vibration of vacuum treatment units are analysed. It is shown that the vibration spectrum is dominated by low and high frequency ranges. In the low-frequency range the vibration of vacuum treatment units is connected with bath oscillations and wave formation on the surface, as well as with decarburisation of metal during oxygen blowing and vacuum-carbon deoxidation and degassing processes. In the high-frequency region the sources of vibration are pulsations of vented gases. Correlation relations between vibration and technological parameters of vacuum treatment are established. Possibilities of vibration method for dynamic control of vacuum treatment are shown. The character of vibration signal level change at the frequency of 8 Hz reflects the dynamics of decarburisation during oxygen blowing of metal at reduced pressure. In the established frequency ranges the vibration characteristics allow to control the processes of vacuum-carbon deoxidation and degassing.
Peculiarities of High-Temperature Refining of Carbon Materials
(Ukrainian State University of Chemical Technology, Dnipro, 2023) Sybir, A. V.; Hubynskyi, Semen M.; Fedorov, Serhii S.; Sukhyy, Kostyantyn M.; Hubynskyi, M. V.; Vvedenska, T. Y.
ENG: The purpose of the study was to determine the influence of the main following factors on the efficiency of the process of high-temperature refining of natural and artificial graphite: processing temperature, distribution of metal oxides, and changes in the aggregate state of ash impurities. Thermal processing of natural graphite from Ukrainian deposits and anthracite from Donetsk coal basin was carried out in a chamber furnace at a holding time of 10–20 minutes in a temperature range of 1500–30000 Ñ. The quality of refining was carried out by ICP-OES and XRF analysis methods. It was established that the refining process may be divided into three following periods: 0–16000 Ñ (removal of moisture, volatiles, and decomposition of carbonates); 1600–26000 Ñ (evaporation of main ash-forming metals Fe, Si, Al, Ca, Mg in the form of oxides, silicides, and carbides); and 2600–30000 Ñ (evaporation of refractory compounds Ti, V, Mo, the content of which in the initial raw material determines the processing temperature and the quality of the final product). The distribution of metal oxides in the initial carbon material is not uniform, which complicates the use of equilibrium state models. The transition of ash into the liquid and then gaseous state has a significant impact on the result of heat treatment. This is what determines the choice of the process scheme. Intermittent process is the heating by an external heater in an inert gas environment. Continuous process is the heating of the material in moving containers or processing in an electrothermal fluidized bed.
Thermodynamic Analysis of the Reactions of Strontium Anorthite Formation during the Firing of Thermal Shock Resistance Ceramics Based on the Eutectic Glasses of the SrO–Al2O3–SiO2 Systems
(Ukrainian State University of Chemical Technology, Dnipro, 2023) Zaichuk, Oleksandr V.; Sukhyy, Kostyantyn M.; Amelina, O. A.; Hordeieiv, Y. S.; Filonenko, D. V.; Rudnieva, L. L.; Sukha, Iryna V. ; Halushka, S. A.
ENG: Thermal shock resistance ceramic materials must have a high degree of sintering to ensure the required mechanical strength, erosion resistance, and resistance to high-temperature oxidation. However, the search for effective ways to achieve a high degree of sintering of ceramic materials based on the SrO–Al2O3–SiO2 system at low temperatures requires a large amount of experimental research. The aim of this work is to analyze thermodynamically the reactions of strontium-anorthite phase formation at the points of triple eutectics of the SrO–Al2O3–SiO2 system under low-temperature firing conditions. The eutectic points were selected in the region of strontium anorthite crystallization and had a temperature not exceeding 14000C. It has been established that in the case of compliance with the stoichiometric ratio, the final product of the interaction of the components of eutectic glasses S-1 and S-2 with the charging components is the strontium anorthite phase. The most probable is the formation of strontium anorthite in the interaction of eutectic glass components with Al2O3∙2SiO2, which is a product of kaolinite dehydration (Al2O3∙2SiO2∙2H2O). It has been found that the compounds SrO∙SiO2 and 2SrO∙Al2O3∙SiO2 are most active in the interaction with the charging components in the direction of formation of the strontium anorthite phase than SiO2 tridymite. As a result, the sintering of strontium-anorthite compositions at a temperature of 9000C causes a significant increase in the content of the crystalline phase of strontium anorthite. The determined patterns allow making a reasonable choice of glass in the SrO–Al2O3–SiO2 system for the further manufacture of low-temperature strontium-anorthite ceramics.
Bifurcation State and Rational Design of Three-Layer Reinforced Compound Cone-Cylinder Shell Structure under Combined Loading
(Publishing House “Akademperiodyka”, Kyiv, 2023) Gristchak, V. Z.; Hryshchak, D. V.; Dyachenko, N. M.; Sanin, A. F.; Sukhyy, Kostyantyn M.
ENG: An analytical-numerical approach to solving the problem of state bifurcation in terms of local and overall stability of a three-layer cone-cylinder shell structure discretely supported by intermediate rings, in particular of modern launch vehicles, under static combined loading by external pressure, axial forces, and torque is proposed in the paper taking into account the stiffness parameters of the intermediate rings in the plane of the initial curvature and for torsion. Corresponding solving equations for the problem are ordinary differential equations of the sixth order (for a cylindrical compartment with constant coefficients and for a conical one with variable coefficients along the axial coordinate). Differential relations that determine the conditions of conjugation through the intermediate ring are used. For the numerical solution, the finite difference method is used with central finite differences of the third and second order at the inner points of the shell determination segments and at its ends, respectively, and the second order differences with one step backward or forward at the conjugation points through the ring. The agreement of the calculation results with the known data for three-layer conical and cylindrical shells is shown, as well as in the limiting case, it is done when passing to a single-layer compound cone-cylinder structure. For the considered class of cone-cylinder shell structures, boundary surfaces are constructed that separate the stability region of the structure being under study, depending on the geometric and stiffness parameters of the compartments, reinforcing elements, and the external load condition. The external load effect on the parameter of the post-critical wave formation for the structure under investigation is studied, providing the visualization of the deformation behavior. The analysis of the calculation results has shown that this approach to solving the problem of bifurcation and equistability of the compound structure compartments in relation to the local and overall forms of protrusion allows choosing rational geometric and stiffness parameters of the shell components and force elements in terms of improving the weight characteristics of the structure.
Solid-Phase Polycondensation of Polyethylene Terephthalate with Technologies of Its Reactive Extrusion
(MM Publishing s.r.o., Praha, Czechia, 2023) Rimar, Miroslav; Chervakov, Denys O.; Fedak, Marcel; Kulikov, Andrii; Kulikova, Olha; Sukhyy, Kostyantyn M.; Chervakov, Oleh V.; Bentsionov, Igor; Sverdlikovska, Olga S.; Belyanovskaya, Elena; Yeromin, Oleksandr O.; Prokopenko, Olena M.
ENG: It has been experimentally confirmed that polyethylene terephthalate during its processing into products destruct without carrying out the process of solid-phase polycondensation. The conditions for both primary and secondary polyethylene terephthalate have been determined for carrying out the process of solid-phase polycondensation for its effective reaction extrusion with chain extenders. To confirm the effectiveness of the parameters of the solid-phase polycondensation process of polyethylene terephthalate, its reaction extrusion was carried out with commercially available chain extenders of the diepoxide class. The optimal content of chain extenders of the diepoxide class for changing the complex of physical, mechanical and rheological properties of polyethylene terephthalate modified by them was determined. It allows obtaining materials with an increased by 2.2 times characteristic viscosity.
The Influence of Solid-State Polycondensation of Polyethylene Terephthalate on Its Rheological Properties
(Ukrainian State University of Chemical Technology, Dnipro, 2024) Chervakov, Denys O.; Ved, V. V.; Fedan, V. V.; Sukhyy, Kostyantyn M.; Chervakov, Oleh V.
ENG: The influence of solid-state polycondensation conditions on the rheological properties of polyethylene terephthalate was determined. Mathematical models describing the dependence of the melt flow rate of both virgin and recycled polyethylene terephthalate on the time and temperature of the solid-state polycondensation process were developed. A correlation between the melt flow rate and the average molecular weight of polyethylene terephthalate was demonstrated. Experimental studies showed that conducting solid-state polycondensation of recycled polyethylene terephthalate at temperatures ranging from 130 оC to 160 оC for 3 hours produces polymeric materials with higher molecular weight and, consequently, improved performance properties.
Properties of Zr–Ti–Nb and Ti–Al–V Alloys
(Ukrainian State University of Chemical Technology, Dnipro, 2024) Kovalyov, S. V.; Ovchynnykov, O. V.; Sukhyy, Kostyantyn M.; Yefanov, V. S.; Kalinichenko, O. O.; Koval’ova, N. V.
ENG: This article is devoted to studying the properties of the new Zr–Ti–Nb alloy and comparing it with the well-known Ti–Al–V alloy (ÂÒ-6, Grade 5 analog). The properties were analyzed through chemical composition determination and corrosion resistance assessment. The Zr–Ti–Nb alloy does not contain the toxic impurities present in the Ti–Al–V alloy, specifically aluminum and vanadium. Structural studies were conducted to identify the phases (X-ray diffraction analysis) and their composition using scanning electron microscopy. The microstructure and phase composition of the Zr–Ti–Nb alloy indicated a uniform distribution of elements throughout the alloy. The wetting angle of the Zr–Ti–Nb alloy with an oxide layer is significantly smaller than that of the Ti–Al–V alloy, suggesting greater hydrophilicity. Physical research methods included determining density, reflectivity, and electrical conductivity. Mechanical properties were examined by determining the elastic modulus, strength limit, yield strength, longitudinal elongation, transverse contraction, and microhardness. Notably, the elastic modulus of the Zr–Ti–Nb alloy is 26.4 GPa, similar to that of cortical bone, in contrast to the Ti–Al–V alloy, which has an elastic modulus of 110–140 GPa. The obtained data indicate that the superior chemical and mechanical properties of the Zr–Ti–Nb alloy make it suitable for medical applications.
Determining the Energy Efficiency Indicators of the Diesel Train DPKr-2 and the Rail Bus 620M Based on Traction Calculations Using the Numerical Method of Solving the Equation of Train Movement
(MATEC Web of Conferences, 2024) Kapica, Mihajlo; Bobyr, Dmytro V.; Hryshchenko, Mykola A.; Kyslyi, Dmytro M.; Desiak, Andrii Y.
ENG: The purpose of the article is to compare the technical and energy parameters of the diesel train DPKr-2 and the railbus 620M based on traction calculations using mathematical modeling when solving the train movement equation. The mathematical model of the train is adapted to determine the movement parameters of the specified rolling stock units according to different variable phase coordinates for different movement modes. To achieve this purpose, the authors used methods of system analysis, nonlinear programming, and numerical methods for solving differential equations. The accuracy of the calculations was verified using simulation modeling methods and compared with experimental data. To analyze the results, the obtained indicators of traction calculations – technical speed and specific consumption of diesel fuel – were compared. As a result of the comparison, the specific fuel consumption per ton-kilometer meter, a significant saving of energy resources is observed. Comparative specific fuel consumption per passenger-kilometer meter, on the contrary, indicates an increase in the consumption of energy resources. The mathematical model of the train is adapted to determine the movement parameters of diesel trains and rail buses according to different variable phase coordinates for different drive modes. The practical significance lies in determining the efficiency indicators of the use of different types of rolling stock on the railways of Ukraine, taking into account economic, social and migration factors.
Modernization of the Power Supply System Applying Solar Cells and Batteries
(MATEC Web of Conferences, 2024) Serdiuk, Tetiana M.; Serchenko, Maksym; Radkevych, Anatolii V.; Serdiuk, Svitlana; Skalko, Viktor
ENG: In this paper, an assessment was made of the installation of solar panels as a backup power source for the Post of electric centralization. The advantages of using this system and an example of calculations for the Post of electric centralization were given. The norms of electricity consumption were analyzed.
Optimality Criteria for the Process of Technical Operation of Locomotives
(MATEC Web of Conferences, 2024) Kapica, Mihajlo; Bobyr, Dmytro V.; Kyslyi, Dmytro M.; Desiak, Andrii Y.; Bohomolov, Andrii
ENG: The efficiency of a locomotive fleet as a complex system depends significantly on the mode and conditions of its operation, which, in many cases, are determined both by its own condition and by the state of the maintenance system. In reality, changes in the state of the system, and its further behaviour in most cases can be described by the Markov process. It should be noted the excessive rigidity of the hypothesis about the Markov character of the behaviour in the process of technical operation of the locomotive fleet that makes the resulting model insufficiently adequate. The article proposes a methodology to assess the efficiency in the functioning of the locomotive fleet as a semi-Markov system. Relationships for calculating the main statistical characteristics of the efficiency indicators in the process of technical operation of locomotives have been obtained. The choice of optimality criteria for the process is justified. A procedure for constructing an ordered sequence of enhancing maintenance and repair strategies, considering the condition of a particular locomotive has been offered. Determining the optimality criteria for the technical operation process of the locomotive fleet based on the research of stochastic estimates in the efficiency of the semi-Markov model. Obtaining a sequence of maintenance and repair strategies. The efficiency of locomotive fleet operation significantly depends on the quality of service. The quality of service is determined by the effectiveness of diagnostic tools for technical conditions. The process of operating a locomotive fleet is described by a semi-Markov model. The semi-Markov model used makes it possible to more fully take into account, in the general case, the diagnostic support of the locomotive and the restoration process. The unit cost function the average unit cost, the average unit loss coefficient the coefficient of average, and operating factor was selected as target functions. A procedure has been proposed for constructing an ordered sequence of improving maintenance and repair strategies, considering the condition of a particular locomotive.
The Application of Fuzzy Sets Theory in the Methodological Approach to Assessing Personnel Risks of an Enterprise
(Alfred Nobel University, Dnipro, 2024) Harmider, L.; Korotka, Larysa I.; Bazhan, Serhii P.; Aniskevich, D.
ENG: The main idea of this paper is the substantiation of the methodological approach to the assessment of personnel risks of enterprises based on the application of the fuzzy logic apparatus in order to identify the problems of personnel risk management and provide appropriate recommendations for their solution. The methodological basis of the study is the classic provisions and fundamental works of foreign and domestic scientists, statistical data, the results of our research into the problems of assessing personnel risks of enterprises. The methods of fuzzy set theory, comparative analysis, scientific abstraction, generalization of scientific experience of modern theoretical research, system-complex approach were used. The study proposed a methodological approach to assessing the level of personnel risks of an enterprise; numerical experiments were conducted on the basis of a group of construction equipment manufacturers. Analysis of the results of assessing the level of personnel risks of enterprises made it possible to identify the problems of managing personnel risks at enterprises. The proposed methodological approach to assessing the level of personnel risks of enterprises based on the apparatus of fuzzy logic allows, in contrast to existing ones, to integrate the consideration of both qualitative and quantitative indicators when assessing the level of personnel risks and personnel movement indicators and to significantly increase the efficiency of decision-making under conditions of uncertainty and reduce costs in the event of adverse situations. Using in practice a methodological approach to assessing the level of personnel risks of enterprises based on the apparatus of fuzzy logic allows us to analyze the level of personnel risk as a multi-element object that is closely related to the structured functioning of the enterprise and its capabilities; and expands the original basis for conclusions, which provides a more accurate assessment of the level of personnel risk and making a reasoned decision to reduce its level.
Features of the Swelling Kinetics of Polymer Materials in Blended Diesel Fuel
(Lviv Polytechnic National University, Lviv, 2024) Shevchenko, Olena; Popytailenko, Daryna; Ebich, Yurii; Zamikula, Kostiantyn; Sukhyi, Kostiantyn M.; Vytrykush, Nataliya
ENG: The work is devoted to determining the features of the swelling kinetic patterns of polymer materials in contact with blended fuel containing fatty acid esters. Kinetic equations for predicting the behavior of polymer materials in contact with blended fuel at different temperatures were obtained. Peculiarities of the swelling kinetics of polymer materials with different chemical structures in blended diesel fuel were studied. It was found that the process proceeds in two stages for any temperature conditions. The effect of fatty acid esters in the composition of blended diesel fuel on the stability of polymer materials depending on their structure and temperature factor was determined. An approach to the selection of polymer materials resistant to the effects of fatty acid esters is proposed. The patterns of changes in the swelling resistance of polymer materials upon contact with blended diesel fuel, depending on their structure, were determined.

Browse

Browsing Ректорат УДУНТ by Issue Date

Results Per Page

Sort Options