Ректорат УДУНТ

Permanent URI for this collectionhttps://crust.ust.edu.ua/handle/123456789/19312

ENG: Rectorate of the USUST

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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.
Assessment of the Efficiency of Hot Helium Tank Pressurization Systems for Oxygen-Propelled Rocket Engines
(Publishing House “Akademperiodyka”, Kyiv, 2025) Sukhyi, Kostiantyn M.; Voit, S. M.; Mitikov, Yurii O.; Spirkin, S. V.; Sukha, Iryna V.
ENG: For the first time, a study of the design has been conducted, and a detailed weight summary of the hot helium pressurization system for an oxidizer tank of the first stage of a launch vehicle (LV) has been presented; the propulsion system of this LV uses boiling oxygen — RG-1 as propellants. The oxidizing generator gas was considered as the heat exchanger heat carrier. The weight of this system was also evaluated for an alternative common heat carrier — reduced generator gas. A good correlation was shown between the obtained results and known data from other pressurization systems. The efficiency of hot helium pressurization systems is demonstrated in the case of multiple reuses of the first stage of an LV. It is also reasonable to use it for the dual activation of the liquid rocket engine (LRE) of the second stage of an LV. In these cases, arising issues are solved using well-established, proven solutions. However, an analysis of technical literature shows that alternative solutions have not been thoroughly studied. In other cases, considering the high cost, structural complexity, actual low reliability, and lack of weight advantages, the use of hot helium pressurization systems (PS) is hardly justified. This primarily concerns LREs with afterburning of generator gas, where oxidizing gas is used as the coolant in the heat exchanger. It is also noted that it is necessary to provide helium reserves on board of the LV and to introduce a gas pressure regulation system in the tank. This is due to the large variations in pressurization path resistance and helium temperatures after the heat exchanger at the design stage. The result is an increase in the calculated gas pressure in the tank, leading to an additional weight increase of 5–8%. It is shown that helium reserves can be easily adjusted based on the results of the first flight tests, whereas reducing the thickness of the tank walls and the diameter of the hot pressurization pipelines with thermal compensators is extremely problematic.
Assessment of the Impact of Operating Conditions on the Reliability of Bar-Type Steel Structures
(Український державний університет науки і технологій, Дніпро, 2025) Ivanova, Hanna; Radkevych, Anatolii V.; Olishevska, Sofiia; Tianwei, Ma
ENG: Purpose. The study aims to develop a comprehensive approach to calculating the residual service life of spatial multi-element steel bar structures, taking into account both predictable and random factors that affect the structures or their individual elements throughout their service life. Methodology. The key causes of corrosion damage are examined, and models of corrosion wear are analyzed, including those that consider the effects of mechanical stresses and aggressive environments. The use of different types of survivability indicators – both deterministic and stochastic – allows for a more accurate assessment of structural reliability under real operating conditions. It is noted that current construction standards insufficiently account for the time-dependent development of defects, which complicates the assessment of the residual service life of structures. The need for a comprehensive approach to forecasting the reliability and durability of steel structures in actual service conditions is emphasized. Findings. It is demonstrated that traditional calculation methods do not adequately assess the durability and survivability of structures with evolving defects. An approach to evaluating the survivability of steel structures is proposed, based on the use of both deterministic and stochastic indicators. This allows for consideration of both systematic and random changes in the behavior of the structural system. The advantage of mathematical modeling over physical modeling is substantiated, particularly in its ability to account for multiple scenarios of corrosion development and the complex interaction of corrosion with mechanical influences. Parameters characterizing the condition of a structure under corrosion wear have been identified. Originality. A comprehensive approach to assessing the reliability and survivability of bar-type steel structures under corrosion wear has been developed, based on a combination of deterministic and stochastic indicators. Mathematical models of corrosion damage are considered, taking into account the influence of both stress–strain state and aggressive environments. Practical value. The obtained results can be used in the design, diagnostics, and forecasting of the technical condition of bar-type steel structures operating in aggressive environments and exposed to various types of loads.
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.
Carbon Materials for Electrically Conductive Concrete
(EDP Sciences - Web of Conferences, France, 2024) Savytskyi, Mykola V.; Sukhyy, Kostyantyn M.; Savytskyi, Oleksandr M.; Babenko, Maryna; Shevchenko, Tetyana
ENG: In recent decades, the direction of building materials science related to the creation of Smart Concretes has been rapidly developing. Smart Concretes, in addition to the functions of a structural material, also perform other functions that are related to their new properties. Among the large number of Smart Concretes, it is necessary to highlight Electrically Conductive Smart Concrete. This type of concrete is obtained by adding conductive fillers to the concrete mixture. Among them, carbon materials are the most promising in terms of their properties. Despite the large number of conducted studies of conductive fillers and conductive concrete, there is still no generalization and systematization of them. In addition, there are no standards for testing the conductive properties of both fillers and concretes. Therefore, the authors aimed to systematize data on Electrically Conductive Smart Concrete, as well as electrically conductive carbon fillers. A method for testing the electrical conductivity of Carbon Nanomaterials (CNMs) as fillers for Electrically Conductive Concrete is proposed. Approbation of the proposed method was carried out by determining the electrotechnical indicators of carbon fillers, such as coke breeze and carbon black.
The Concept of Anthropotechnics in the Social and Humanitarian Dimension
(Український державний університет науки і технологій, Дніпро, 2024) Bazhan, Serhii P. ; Chernova, Nataliia S.
ENG: Purpose. This research defines the conceptual foundations of anthropotechnics as a science that studies modern processes of interaction between humans and technologies in the socio-humanitarian dimension. Theoretical basis. The authors use the method of anthropological analysis, which allows generalizing the approaches of anthropotech-nics in the socio-cultural context in the "human-technology" system. Originality. Based on the results of the re-search, the understanding of the essence of anthropotechnics as a science that studies human interaction with tech-nologies and technical systems has been clarified. The idea of implementing anthropotechnical approaches to the management of the educational process gained further development, in particular in the context of practical training of applicants for education, distance learning, and dual education forms. The concept of professional activity and professional self-realization of the individual is taken into account, and promising directions in the development of anthropotechnics in the context of the application of artificial intelligence are determined. Conclusions. Considering anthropotechnics in a philosophical and sociocultural dimension is an important approach to understanding the in-teraction of technologies, people, and society as a whole, where technologies affect human perception of the world and interaction with it. The range of approaches chosen by the authors, the disclosure of their principles and catego-ries allows for considering the object of this research – anthropotechnics as a modern science – in a multifaceted and holistic way, to interpret the results of the research based on the use of the basic categories of approaches: a person, equipment, technology, activity, development, personality, system.
Coordinated Control of the Composition of 01yut Steel and Deformation Processing Modes to Achieve Specified Mechanical Properties
(National Metallurgical Academy of Ukraine, Ukrainian State University of Science and Technologies, Dnipro, 2024) Velychko, A. G.; Kamkin, V. Yu.; Proidak, Yurii S.
ENG: Purpose: to investigate the influence of the chemical composition of steel on the output from the chipboard and to establish rational parameters of deoxidation and deformation to ensure the specified values of mechanical properties. Methods: physicochemical modeling, thermodynamic calculations, experimental studies. Results: the carbon content and the degree of oxidation of the semi-finished product from the electric furnace for further vacuum treatment to obtain low-carbon steel were determined. With an increase in the oxygen flow rate supplied to the chipboard and exceeding the value required for the stoichiometry of fuel combustion reactions, the oxidation of the semi-finished product increases. To avoid the formation of calcium silicates, it is necessary to have an active oxygen content below 2.5 ppm, which is ensured by the residual content of dissolved aluminum in steel of 0.025-0.027%. Scientific novelty: The use of complex deoxidizers in steel production allows using the synergistic effect of the joint deoxidizing action of deoxidizing elements. The use of the methodology of physicochemical modeling made it possible to effectively solve the problem of predicting the properties of steel. To study the influence of modifier elements, as well as the main alloying components, a number of parameters characterizing the state of the alloy as a whole (Zу, d) were calculated. Based on information on the significant influence of the chemical composition of the steel on its properties, a database of 150 compositions was prepared to determine the optimal composition of ultra-low-carbon steels of the 01ЮТ, 01ЮТА type by the method of physicochemical modeling. Based on the calculations, the concentrations of elements for steels of the 01ЮТ and 01ЮТА grades were selected.
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.
Determining Technological Parameters for the Additive Electron-Beam Surfacing of Blanks for Medical Implants Made of ZR-TI-NB Alloy
(ПП «Технологічний Центр», Харків, Україна, 2025) Matviichuk, Vladyslav; Nesterenkov, Vladimir; Efanov, Volodymyr; Zavgorodny, Olexandr; Bilyi, Roman
ENG: The object of this study is the alloys of the Zr-Ti-Nb system, which better than titanium alloys meet the criterion for mechano-biocompatibility of the material for dental implants. The choice of this material is due to the fact that zirconium alloys are free of toxic elements and have a low modulus of elasticity. Under modern conditions of active implementation of additive technologies for the manufacture of metal products, the use of zirconium alloys for 3D printing is a promising area. Such technologies include electron-beam growing of products. The task solved in this work relates to the lack of technological modes for electron beam technology, specifically for zirconium alloy. A rational regime has been determined, under which samples were grown from the alloy of the Zr-Ti-Nb system with a smooth surface, uniform structure, and no internal defects. It should be especially noted that the modulus of elasticity of the material of the manufactured samples was 59.8 GPa, which is two times lower than that of the titanium alloy Ti-6Al-4VELI (113.8 GPa) and is closer to the modulus of elasticity of human bone (30 GPa). The results are explained from the point of view of physical-mechanical processes occurring in the metal during layer-by-layer surfacing under different conditions. These conditions were created by different values of technological parameters. Special feature of the results is that the formed requirements for the structure and properties of zirconium blanks were based on known dependences for titanium alloys. The findings showed that electron beam growing could become an alternative technology for manufacturing implant blanks from low-modulus zirconium alloy. The scope and conditions of practical use of the results extend to materials for implants in dentistry and, in the future, in orthopedics.
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.
Development of Rare Earth Metal-Modified Heat-Resistant Coatings for Gas Turbine Blades
(Ukrainian State University of Chemical Technology, Dnipro, 2024) Yefanov, V. S.; Gnatenko, M. O.; Laptieva, H. M.; Basov, Y. F.; Sukhyy, Kostyantyn M.; Kovalyov, S. V.; Popov, S. M.
ENG: This paper presents an investigation into the influence of Y-La and Y-Hf-La modifiers on the structure and properties of Ni-Cr-Al consumable cathodes used for heat-resistant coatings on turbine blades via the arc-ion plating method. The study shows that the introduction of these modifiers positively affects the structure formation process of the consumable cathodes. The modifiers contribute to a higher degree of microstructural homogeneity in the cathodes, achieved through the formation of nanosized stabilizing phases between the alloying elements and the rare earth metal groups. This study experimentally confirms that Ni-Cr-Al coatings produced with the Y-La and Y-Hf-La modified cathodes outperform traditional Y-only modified coatings in oxidation tests. Structural analysis of the coatings reveals that samples with Y-Hf-La exhibit greater homogeneity and fewer defects, which is particularly important when depositing coatings with large thicknesses (over 40 µm). It was found that the introduction of the Y-Hf-La complex enables the application of coatings up to 90 µm thick by forming a less defective structure. Additionally, it has been established that Y-Hf-La modification enhances the adhesion of the coating to the substrate and allows for maximum uniformity in the distribution of alloying elements throughout the entire thickness of the applied coating.
Development of Test Methods in the Process of Electrically Conductive Concrete Production
(IOP Publishing Ltd, 2024) Savytskyi, Mykola V.; Pang, Weixiang; Sun, Lijun; Savytskyi, Oleksandr M.; Bordun, Maryna; Li, Yang; Xia, Yanfang; Wang, Haojie
ENG: Prevention of climate change, implementation of sustainable development principles in building industry, creation of Green buildings, Three-zero buildings (zero energy, zero emissions, zero waste), energy independent buildings maybe on the base of Smart Concrete. Electrically Conductive Concrete as type of Smart Concrete have the possibilities to create multifunctional hybrid structures for various purposes. The production of electrically conductive concrete is usually based on the introduction of carbon materials and carbon nanomaterials (CNMs) as electrically conductive fillers into its concrete composition. The theory of conductive percolation is used for design of electrically conductive concrete. To select electrically conductive carbon filler, it is necessary to summarize their electrically conductive characteristics. Today, there is no standard for determining the electrical conductivity of carbon fillers, nor is there a method for designing the composition of electrically conductive concrete; the development of both is imperative. Features of the preparation of electrically conductive concrete with hydrophobic carbon nanoparticles prone to aggregation are indicated. To obtain high quality electrically conductive products an operating system for quality control at the stages of the technological process of manufacturing must be proposed. Homogenization of the electrically conductive filler is very important. It is necessary to propose a method for assessing the stability of an aqueous suspension of a hydrophobic carbon material used for homogeneous distribution of a filler. Due to the lack of a standard, a method for determining the electrical conductivity of concrete is also needed.
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.
Digital technologies as modern infrastructure for information support of education and scientific communication: the experience of USUST
(Український державний університет науки і технологій, Дніпро, 2025) Radkevych, Anatolii V.; Kolesnykova, Tetiana O.; Soroka, Maksym L.; Rybalka, Roman V.
ENG: This paper examines the experience of the Ukrainian State University of Science and Technologies in employing digital technologies as a contemporary infrastructure for supporting educational and scholarly communication. It presents a concise overview of the Erasmus+ project “Open science supporting vulnerable communities: empowering university libraries in crisis response” (CAELUM), in which the authors are participants and which materials underpin this study. Within the framework of the CAELUM project, the authors investigated the experiences and expectations of users interacting with the scientific libraries of Ukrainian universities during crises. Anonymised data were collected from 72 respondents aged 18 and above, representing diverse roles within the academic community, through online interviews and questionnaires. Responses to five closed-ended questions were analysed using cluster analysis, resulting in the identification of four distinct respondent clusters. Subsequently, a semantic analysis was conducted on responses to four open-ended questions. The findings enabled the identification of four target user groups of university library services in the context of crisis response. This provides a basis for university libraries to organise their activities more effectively by accounting for the needs and interests of these groups.
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.
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.
Green Technologies in the Design of Single-Storey Frameworks
(Dnipro University of Technology, Dnipro, 2025) Radkevych, Anatolii V.; Bannikov, Dmytro O.; Wu, H.; Lv, R.; Klochko, Leonid I.
ENG: Purpose. Analysis of the effectiveness of long-span structural systems based on glued laminated timber for a single-storey frame of a public building. Methodology. The study used a set of research methods, including scientific analysis and synthesis of available technical information on the use of modern wood products for the design of load-bearing frames of buildings with large spans. Computer modelling methods based on the numerical method of structural mechanics – the finite element method – were also used. The analysis of the structural options was performed using the finite element method using the SCAD (Ukraine) design and computing complex. A separate area of work involved design development, which included methods of engineering assessment of the accuracy and reliability of the results obtained, as well as the execution of design documentation. Findings. For the considered structural variants of the equipment compartment frame covering, stress-strain state patterns, as well as natural frequency spectra and vibration modes, were obtained. The structural variant of the frame recommended for practical implementation is based on the set of technical and economic indicators involves the use of an arched covering system. It is also shown that the use of biocomposite glued beams opens up reserves for reducing the material consumption of the structure by preliminary estimates up to 25 %. Originality. The conducted research studies allowed estimating in complex the static and dynamic load-bearing capacity of a large-span frame using glued laminated timber. The high efficiency of the combined frame system, especially in the case of biocomposite timber, has been proven. The obtained frequency spectrum is discrete and lies in the lower frequency range of 1.5‒5.0 Hz. Practical value. The use of glued and biocomposite timber beams for load-bearing elements of single-storey frames opens up a direction of green technologies for specialized buildings, such as a Fire Station. In combination with modern finishing materials such as fire-resistant wood wool, this allows increasing the operational qualities of wooden structures.
How Much Is Needed? Discussion on Benchmarks for Primary Energy Input and Global Warming Potential Caused by Building Construction
(MDPI, Basel, Switzerland, 2025) Rabenseifer, Roman; Kalivodová, Martina; Kononets, Yevhen; Mahas, Nataliia; Minarovičová, Katarína; Provazník, Robert; Bordun, Maryna; Shekhorkina, Svitlana; Savytskyi, Mykola V.; Savytskyi, Oleksandr M.; Semko, Volodymyr
ENG: The operational energy efficiency of new buildings in the EU should be at the level of ultra-low or near-zero energy buildings. It is therefore relatively difficult to achieve further energy savings. However, the pre-operational phase—raw material sourcing, manufacturing, transportation, and construction—offers significant energy savings and greenhouse gas reduction opportunities, referred to as embodied energy and equivalent CO2 emissions. Unlike operational energy, no standard or legislative criteria have yet been established for embodied energy. Setting maximum embodied energy values converted to the unit of heated building area, accounting for building shape factor, and differentiating between high-mass and lightweight constructions are proposed. This study illustrates assessing environmental indicators based on building shape, highlighting the necessity of relative assessments over absolute values to favour energy efficiency. It also emphasizes that precise criteria should derive from authentic data collected during the energy certification and building permitting processes. Integrating assessments of embodied energy and operational energy demand facilitates a comprehensive evaluation of buildings’ environmental performance.
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.
Innovative Technological Concept for the Production of High-Density Cathodes for Lithium Reserve Power Sources with Increased Specific Energy
(Ukrainian State University of Chemical Technology, Dnipro, 2024) Markevych, O. V.; Polishchuk, Y. V.; Zinin, V. V.; Vavilon, K. I.; Sukhyy, Kostyantyn M.
ENG: This paper presents an innovative technological concept that significantly enhances the specific energy (both gravimetric and volumetric) of primary lithium power sources. A composition and laboratory-scale process for manufacturing composite cathodes with minimal electrochemically inactive («ballast») components have been developed. The proposed approach enables the production of high-density cathodes without significantly reducing their porosity. The composite cathodes were tested in disc-shaped primary power sources with dimensions of 2325 (23 mm in diameter and 2.5 mm in height). The effect of graphene content in the cathode mass on the discharge voltage of the cells was investigated. It was demonstrated that a graphene content of 3 % by weight of MnO2 in the cathode mass increases the average discharge voltage of the cells from 2.1 V to 2.5 V at a discharge current of 1 mA. Testing at a discharge current of 1 mA revealed that the capacity of the developed cells exceeds that of the best commercial counterparts by at least 40 %.
Investigation of Phase Equilibria in the MnO–Al2O3 System by Differential Scanning Calorimetry Method
(Ukrainian State University of Science and Technologies, Dnipro, 2025) Proidak, Yurii S.; Gladkykh, Volodymyr A.; Ruban, Artem V.; Riabtsev, O. O.
ENG: All slag from the production of manganese ferroalloys can be conditionally attributed to the system MnO–CaO–SiO2–Al2O3, since the sum of these oxides reaches 95–98% with MnO content from 18% to 48%. On the practical side, it is crucial to know the peculiarities of the behavior of silicate systems over a wide temperature range and in the presence of various additives. Differential scanning calorimetry was employed to study concentration–temperature transformations in melts corresponding to manganese aluminate, the low-temperature eutectic E1, and a manganese-rich region with 10% Al2O3 content. The conducted research indicates a congruently melting nature of manganese spinel MnAl2O4. The preservation of short-range order during the melting of MnAl2O4 affects the thermodynamic stability parameters of the compound and the temperature at the onset of manganese recovery during carbothermic reduction. The congruent melting of manganese spinel implies the presence of a second eutectic E2, positioned between MnAl2O4 and Al2O3. According to experimental data, the melting temperature of eutectic E2 is lower, approximately 1720 Celsius degrees.
Methodology of Comprehensive Diagnostics of Technical Educational and Scientific Cluster Management Risks
(Dnipro University of Technology, Dnipro, 2025) Bazhan, Serhii P.; Harmider, L. D.; Korotka, Larysa I.; Kryvoruchko, A. I.
ENG: Purpose. Substantiation of the methodological approach to assessing the indispensable dangers of managing a technical educational and scientific cluster based on utilizing a fuzzy rationale instrument in order to distinguish issues within the educational cluster and give suitable suggestions for their solution. Methodology. The methodological premise of the research is the classical provisions and fundamental works by foreign and domestic scientists, statistical data, and the results of unique investigation on the issues of surveying the dangers of cluster improvement. The research utilized the method of fuzzy set theory, comparative analysis, method of abstractions, generalization of the results of advanced theoretical research, a systematic and comprehensive approach. Findings. A methodological approach to surveying the dangers of managing a technical educational and scientific cluster was proposed, various tests were carried out based on the official statistics. The analysis of the results of evaluating the main components that impact the performance of the technical educational and scientific cluster made it possible to distinguish issues within the functioning of the cluster and to identify ways to solve them. Originality. The methodological approach to the evaluation of integral dangers based on the device of fuzzy rationale has been progressed, which, unlike the existing ones, permits you to coordinate strategies of the theory of fuzzy sets and fuzzy rationale and permits you to achieve more exact and important outcomes compared to the conventional strategies. The proposed approach can be utilized in different areas where processing of expansive volumes of fuzzy data is required. Practical value. The practical significance of the study arises from the possibility of applying the developed fuzzy model for making managerial decisions in a technical educational and scientific cluster under conditions of uncertainty.
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.
Oleochemical Products in Synthesis Technologies of Eco-Friendly Polymers
(Oles Honchar Dnipro National University, Dnipro, 2024) Chervakov, Oleh V.; Chervakov, Denys O.; Sukhyy, Kostyantyn M.; Kuzminskyi, Vitalii Yu.; Varlan, Kostiantyn Ye.; Belyanovskaya, Elena A.; Levchenko, Yevhenii P.; Yurchik, Mykhailo S.
ENG: Promising directions of synthesis from renewable vegetable oil raw materials of monomeric and oligomeric oleochemical products are considered: modified triglycerides as ingredients of special-purpose polymer compositions; fatty alcohols, esters and amides of fatty acids as surfactants in detergents, cosmetics, paints, pharmaceuticals, as ecological fuel; polyols and hydroxyl-containing oligomers for the synthesis of polyurethane, polyesteramide, polyurethaneamide binders and coatings with anti-corrosion and antimicrobial properties. The synthesis routes of fatty acid amides, in particular hydroxyl-containing ones with a functionality of 2 or more, as starting compounds for promising polyesteramides are considered in detail. The strategy of synthesis from vegetable oils of saturated polyols with primary hydroxyl groups as promising components for environmentally friendly paint and varnish compositions is considered. Data on the synthesis and properties of polyurethaneamides, polyesteramides and metal-containing derivatives based on them are presented. For each product type an analysis was made of the state of development of a particular technology, as well as future prospects and existing barriers to their development. The possibility of using metal-containing polymers to create biodegradable materials and coatings with hydrophobic properties and antimicrobial activity was shown.
On the 100th Anniversary of the Department of Electrometallurgy
(Ukrainian State University of Science and Technologies, Dnipro, 2025) Sykhoy, K. M.; Proidak, Yurii S.
ENG: The article reflects the origin and development of the electrometallurgical industry in Ukraine. The emphasis is placed on the role of the Department of Electrometallurgy at the Dnipro Metallurgical Institute in this process. The Department of Electrometallurgy was established in 1925. This was facilitated by the leading role of scientists, professors, doctors of technical sciences Telnyi S. I., Khytryk S. I., Hasyk M. I., who made a significant contribution to the development of the electrometallurgical industry in Ukraine and the training of highly qualified specialists. In the article, the key stages of formation and development of electrometallurgy have been outlined, and the crucial role of scientists and teachers of the Department has been stated.
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.
Parameters and Resource Potential of the Territory of Populated Places in the Zone of Influence of Stopping Points
(EDP Sciences - Web of Conferences, France, 2024) Kulichenko, Nataliia; Savytskyi, Mykola V.; Tovbych, Valery
ENG: The authors did not set a goal to make a comprehensive analysis of all aspects of the formation and functioning of the settlement territories in the zone of stopping points influence. The article is a review and a problem. It provides an overview and analysis of research directly or indirectly related to the problem under consideration. The results of multivariate calculations using the regulatory documents of Ukraine are presented: parameters of the zones of transport lines and stopping points influence (width of the zones of influence, total area of construction and area of residential construction in the zone of influence of one stopping point), resource potential (housing stock, population) for the largest, large, large and small settlements and their zones (central, middle, peripheral). The performed calculations show that the territories of settlements in the zone of influence of stopping points occupy an important place in the planning structure and vital activities of settlements due to their significant resource potential − territory, population, housing stock, as well as the close relationship of their structural parameters with the parameters of the transport infrastructure. which indicates the need to consider them as a whole.
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.
Peculiarities of Organizational and Technological Approaches to the Post-War Restoration of Infrastructural Objects in Ukraine
(E3S Web of Conferences, 2024) Savytskyi, Mykola V.; Radkevych, Anatolyi V.; Savytskyi, Oleksandr M.; Babenko, Maryna; Shevchenko, Tetyana
ENG: As a result of russia's insidious war against Ukraine, thousands of infrastructure facilities and nergetical objects were destroyed or damaged. We are sure, Ukraine will win this war. Already today, the territories of the country freed from the occupiers with the destruction of residential and civilian buildings, infrastructure facilities need restoration. In Ukraine, the Government Plan for the Recovery of Ukraine has been developed. Ukraine's Recovery Plan is aimed at ccelerating sustainable economic growth. But this Program outlines general approaches and directions for he recovery and development of Ukraine. Therefore, it is necessary to develop detailed local rograms that contain organizational and technological approaches to the implementation of restoration works. The programs must to help local authorities, territorial communities in which housing and social infrastructure objects were damaged or destroyed as a result of russian armed aggression, to make decisions regarding the planning and implementation of restoration works and the development of territories. Purpose of the study: to develop detailed Local Program which specifies the National Programs of the Recovery Plan of Ukraine and contain organizational and technological approaches to the implementation of restoration works.
Performance of Heat Pump Based on Composite Adsorbent ‘Silica Gel – Crystalline Hydrate’
(Odesa National University of Technology, Odesa, 2025) Belyanovskaya, Elena A.; Sukhyy, Kostyantyn M.; Serhiienko, Yana O.; Sukhyy, Mikhaylo K.; Sukha, Irina V.
ENG: Performance of an adsorptive heat pump has been studied. The factors affecting the efficiency of its work have been analyzed. Operating parameters and efficiency of adsorptive heat pumps and adsorptive heat storage devices have been compared. An algorithm of calculating the basic operating characteristics of an adsorption heat pump in heat supply systems has been proposed. It involves calculating the mass transfer coefficient, final absolute humidity of the air flow passed though adsorbent layer, the water uptake or adsorption and the useful heat of adsorption and heat of condensation, determination of heat inputs for the operation of the device such as heating the adsorbent, case of the device, hydraulic circuit, the water in the tank and adsorbed water, heat of desorption and heat of evaporation, estimation the coefficient of energy performance. The evaluation criteria of the efficiency of adsorptive heat pumps and heat storage devices have been compared. It is shown that the operating parameters of the adsorptive heat pump and the adsorptive thermal energy storage device based on composite adsorbents ‘silica gel – sodium sulfate’ and ‘silica gel – sodium acetate’ are the same, i.e. airflow rate 0.08 - 0.1 m3/s and initial absolute humidity of airflow 0.03 – 0.04 kg/m3, which are corresponded with maximal efficiency of the device. The temperature of the humid air flow directed to the adsorbent layer is suggested to be set at 20 – 40 °C. The measures to increase the efficiency of the adsorptive heat pump are proposed. It is shown that ultrasonic air humidification allows to increase the coefficient of energy performance by almost 2 times compared to steam humidification. The obtained results can be used for developing energy-efficient heating systems of residential premises.
Prediction of the Properties of High-Energy Polymer Materials Based on Oleochemical Products
(Ukrainian State University of Science and Technologies, Dnipro, 2025) Varlan, K. Ye.; Chervakov, Oleh V.; Sukhyy, Kostyantyn M.; Belyanovskaya, Elena A.
ENG: A series of oleochemical products, namely amide derivatives of fatty acids from vegetable oils based on diethanolamine, diethylenetriamine, piperazine, and morpholine, was synthesized. The synthesized products are considered as potential components of mixed solid missile fuels: plasticizers, surfactants, and combustion regulators. To evaluate their applicability, the predicted energy characteristics of mixed compositions containing the synthesized oleochemical products were calculated, including the composition of transformation products, heat of combustion, combustion temperature, and specific volume of combustion products. The method of calculation is presented. The obtained characteristics of the compositions based on oleochemical products are comparable to the calculated values for a known composition based on liquid rubber and dioctyl adipate plasticizer: heat of combustion of 5860 kJ/kg, combustion temperature of 3450 K, and specific volume of combustion products of 0.818 m3/kg.
Properties of Railway Wheels Made of Metal with Increased Copper Content
(Printing House “Technologija”, Kaunas, Lithuania, 2024) Proidak, Yurii S.; Chornoivanenko, Kateryna O.; Pikil, O.
ENG: The content of non-ferrous metals and, in particular, copper is limited by numerous standards regulating the chemical composition of steels. Thus, for instance, according to the Ukrainian standard for wheel steel, the residual content of nickel, chromium, and copper should not exceed 0.25% each. According to the international UIC standard, this content should not exceed 0.30% each. The residual copper content according to the Japanese standard is allowed to be not more than 0.35%. Many steelmakers are concerned about the presence of copper due to its red shortness. However, the beneficial effect of Cu on hardenability and transformation kinetics is well-known, enabling the formation of a structure with a high density of dislocations at cooling rates feasible in industrial conditions, thus imparting high initial strength to the matrix. Experimental smelting was conducted in the open-hearth furnaces to obtain 0.15-0.60% of copper in the metal. It was found out that the resistance of slag truck wheels made of metal with increased copper content against the formation of ridge notches, which are the main reason for repairs of these wheels during operation, is significantly higher than that of serial ones.
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.
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.
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.
Static Continuous Bulk Material Model for Inclined Bunker Section
(Dnipro University of Technology, 2025) Radkevytch, Anatolii V.; Bannikov, Dmytro O.; Wu, H.; Cheng, X.
ENG: Purpose. Obtaining an analytical pattern of pressure distribution of bulk material based on the classical Jansen’s model for an inclined outlet part of a hopper with an arbitrary cross-sectional shape. Methodology. The work used a set of research methods, including scientific analysis and synthesis of available technical information regarding the current regulatory and professional approaches to determining the pressure from bulk material in container structures. Computer modeling methods based on the numerical method of structural mechanics ‒ the finite element method ‒ were also used. Analysis of the performance of structural options was carried out using the SCAD design and computing complex (Ukraine). A separate direction in the work was design developments, which included methods for engineering assessment of the accuracy and reliability of the results obtained. Findings. An analytical expression for determining the vertical pressure of bulk material is obtained, which reflects in a closed form the regularities of its distribution for the case of a straight inclined rigid wall of the outlet part of the hopper container with an arbitrary cross-sectional shape. The pressure value of the bulk material according to this expression quantitatively exceeds the pressure value according to known analytical models. This gives grounds to believe that when loading the hopper structures, a change in the structure of the bulk material occurs, which is described in the literature as its loosening. Originality. The conducted researches allowed for the first time to establish the regularities of the pressure distribution of bulk material during static operation of a hopper structure with straight inclined walls. The obtained expression is structurally the product of two power functions, in which the exponent is the expressions that reproduce the geometry of the outlet part of the hopper structure and the material of its side walls. Practical value. The obtained expression allows to calculate the vertical and, if necessary, normal pressure of bulk material for straight inclined walls of hopper structures. It is proved that the pressure increases significantly with increasing its depth, which in the case of unloading the container should lead to the destruction of the static form of laying of bulk material. The developed model is the basis for a more detailed consideration of the characteristics of bulk material, such as the density of laying or the angle of laying.
Study of the Impact of Epoxidized Soybean Oil on the Characteristics of Wood-Polymer Composites
(MDPI, 2025) Kulikov, Andrii; Kryvolapov, Dmytro; Sukhyy, Kostyantyn M.; Yeromin, Oleksandr O.; Fedak, Marcel; Prokopenko, Olena M.; Sukha, Iryna V.; Musaio, Angelo; Hrebik, Tomas
ENG: The effect of epoxidized soybean oil on the operational, technological, and physical and mechanical properties of composites based on high-density recycled polyethylene filled with wood floor was investigated. It has been shown that the introduction of epoxidized soybean oil in the amount of 0.5 wt.% into the wood-polymer composite (WPC) improves the physical, mechanical, and operational properties of the material: the Charpy impact strength (on notched samples) increases from 7.5 kJ/m2 to 20.0 kJ/m2, the bending strength increases from 31.6 MPa to 50.8 MPa, and the coefficient of linear thermal expansion decreases by 15%. With a further increase in the content of epoxidized soybean oil in the composite, its water absorption and technological shrinkage decrease, but its physical and mechanical properties deteriorate.
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.
Аналіз системи управління технічним освітньо-науковим кластером
(Видавничий дім «Гельветика», 2024) Бажан, Сергій Петрович
UKR: Стаття присвячена комплексному аналізу системи управління технічним освітньо-науковим кластером (надалі – ТОНК), утвореного на базі університету. Наведена характеристика системи управління ТОНК, яка включає в себе ключові аспекти управління: стратегічне управління (формування місії, візії, цілей, розробка стратегії розвитку), організаційне управління (структура, процеси, персоналу), фінансове управління (бюджетування, фінансування проектів, облік) та інноваційне управління (стимулювання наукових досліджень, комерціалізація результатів, захист інтелектуальної власності), що є основою для подальшого розроблення моделі ефективного управління кластером, яка враховуватиме специфіку його діяльності та зовнішнього середовища. Проведене дослідження дозволило проаналізувати особливості управління ТОНК та виявити ключові взаємозв’язки між стратегічним плануванням, організаційною структурою та інноваційною діяльністю. Ми встановили, що ефективність ТОНК безпосередньо залежить від чіткого визначення стратегічних цілей, гнучкої організаційної структури, здатності адаптуватися до змін та стимулювання інновацій. Отримані результати свідчать про те, що саме поєднання цих факторів забезпечує сталий розвиток кластера та його конкурентоспроможність. Однак, незважаючи на наявність усіх необхідних компонентів управління, кластер стикається з низкою проблем, таких як недостатнє фінансування інноваційних проектів, відсутність ефективних механізмів координації між учасниками та низький рівень комерціалізації наукових розробок. Саме тому розробка ефективної моделі управління ТОНК є нагальною потребою в контекстів реформи системи освіти України, де ефективне управління є запорукою його успішного розвитку кластера. На основі проведеного аналізу сформульовано пропозиції щодо вдосконалення системи управління кластером. Наше дослідження може бути використане для розробки ефективних стратегій управління ТОНК в різних секторах економіки та сприяти розвитку інноваційної екосистеми в Україні. Мета статті: виявити та здійснити аналіз ключових факторів, що впливають на ефективність управління ТОНК.