Факультет дизайну машин та захисту довкілля (ДМетІ)

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ENG: Faculty of Machine Design and Environmental Protection (DMetI)
Dnipro Metallurgical Institute

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Active Thermoregulation in Lasius Fuliginosus Nests in Spring (Hymenoptera: Formicidae)
(Sapienza University of Rome, Rome, Italy, 2025) Stukalyuk, Stanislav; Radchenko, Yury M.; Balabukh, Vira
ENG: The aim of the study was to investigate characteristics of temperature conditions in Lasius fuliginosus nests in spring to possibly prove the spring warmup hypothesis. In spring (05.03 to 31.05.2024), 3 loggers, allowing measurements of temperature conditions were mounted on the outer walls of 3 L. fuliginosus nests in a deciduous forest near Kyiv (Ukraine). The temperature measurements were taken at 15-minute intervals. Simultaneously, the atmospheric air temperature was measured during the same period (at 3-hour intervals). Nests 1 and 2 were typical for this species: both in empty cores of oak trees (1 m diameter), while Nest 3 was auxiliary and located under a 0.05 m layer of oak bark. The physical data (air and nest wall temperatures) were used to construct a mathematical model of the thermal processes occurring in the core of a carton nest. The modelling showed that the anthills’ ability to maintain nest temperature in spring depends on their size and location inside the tree trunks exposed to environmental influence. The temperature inside a nest follows the average daily air temperature with a slight delay due to thermal inertia of the tree. The nest in tree #1 proved to be the most stable: even during cold spells as low as -5°C, the temperature in the core remained +25°C thanks to metabolic heat. Nest #2 also maintains the required temperature (+25°C) during temperature falls to +5°C. However, nest #3 does not provide conditions for offspring development during sudden cold snaps: the heat emitted is insufficient to compensate for losses at air temperatures below +20°C. This nest is not designed for active thermoregulation. It has been shown that L. fuliginosus are able to actively warm up their nest in spring, and the warmup rates (up to 25–26°C) are similar to the temperature conditions in the red forest ants’ anthills (Formica rufa group).
Adaptive Management Strategies for Decision-Making in Business in the Context of Armed Conflict
(Elite Scientific Forum, Pakistan, 2024) Varakin, Dmytro; Osipenko, Denys; Ishchenko, Vasyl; Hlevatska, Nataliia; Hordieieva, Inna O.
ENG: Studying adaptive management strategies for businesses is crucial in modern geopolitical realities and the increasing prevalence of conflicts. Armed conflicts present challenges such as instability, security risks, supply chain disruptions, and demand shifts. These lead to uncertainty, necessitating flexibility, rapid response, and adaptation to new conditions. This research aims to develop adaptive strategies for the effective functioning and resilience of businesses in conditions of armed conflict. Research methods include reviewing scientific publications, monographic, graphical, analytical, synthesis and analysis, observation, abstraction, and generalisation. A literature review of publications by scholars from various countries on the research problem has been conducted. An analysis of the business environment in the context of military conflict, using Ukraine as a case study based on personal observations, conversations with entrepreneurs, and the processing of statistical materials, has been carried out. Comparing the Economic Sentiment Indicator before and during the war periods made it possible to identify pessimistic attitudes in business across specific sectors. The regulatory and legal acts adopted by the Ukrainian government to regulate and stimulate business activity have been characterised. Key challenges and risks affecting Ukrainian businesses in the context of military conflict have been identified. Ukraine’s main measures for restoring exports during the war have been outlined. Adaptive risk management strategies in Ukrainian businesses under military conflict conditions have been developed, with specific measures identified, along with their primary objectives.
Advancement of Risk Analysis Methods during Prolonging the Service Life of Industrial Equipment
(Springer Nature Switzerland AG, 2023) Belodedenko, Sergii V.; Bilichenko, Galyna M.; Hanush, Vasyl I.; Izhevskyi, Y.
ENG: The aim of the work was to trace the relationship between the durability of the equipment and its maintenance strategy. This is done by examples of basic structures of industrial equipment. They have a long service life and during this time manage to accumulate certain damages that need to be diagnosed, after which decisions on its maintenance and repair must be made. Problems associated with the technique for extending the service life of industrial equipment are addressed. The authors have created a technique called the resource safety index (RSI), which uses this characteristic as a diagnostic metric. The usage of the risk function to control the technical state of base structures is shown in this study. It is demonstrated how the behavior of the risk function afects the choice of the inspection model. A risk function model for base structures is proposed, which is based on the concepts of stepwise assignment of the limit state and the corresponding useful life. An algorithm for determining the optimal period of restoration measures according to minimizing the cost intensity criterion, where the risk indicator is a parameter, has been developed. The proposed concepts were put into practice when deciding on the further operation of the housings of the 350 pipes rolling unit. The housings of the piercing mill and the automatic mill, which had been in operation for 80 years, were diagnosed. For the frst time, it was discovered that the housings risk function at the crack break through point stage can be represented by a linear dependence directly proportional to the accumulation of operating time. One of the signs of deterioration in the technical condition of rolling mill stands is a malfunction of the system of fxing and securing the housings.
Analysis of CFD Modelling Results of Designed Uniflow Vortex Tube Models
(Energetická konzultačná agentura n.o., Prešov, Slovak Republic, 2025) Muzychka, Ihor; Kizek, Jan; Menkov, Andriy; Karakash, Yevhen O.; Kulikov, Andrii
ENG: This study presents the results of CFD modelling of a uniflow Vortex tube based on the Ranque-Hilsch effect. The designed models are based on experimental measurements and calculations presented in [1], with the calculations derived from relationships published by Takahama [2] and Soni [3]. The tube geometry was designed according to these relationships for an inlet pressure of 0.5 MPa, which was also used in the CFD simulations. Two different inlet air geometries were tested. The analysis focused on velocity and temperature fields in the developed mathematical models. The results will serve as a basis for the design of experimental devices.
Analytical Method for Calculating Parameters of Destruction Diagrams of Cylindrical Rock Samples with Their Wedge Form of Destruction
(Wroclaw University of Technology, Wroclaw, Poland, 2025) Vasyliev, Leonid; Rizo, Zakhar; Vasyliev, Dmytro; Kress, Denys; Krasovskyi, Ihor; Katan, Volodymyr; Malich, Mykola H.
ENG: This study aims to develop an analytical method for calculating the parameters of destruction diagrams of cylindrical rock samples experiencing wedge-shaped fractures, facilitating the effective disintegration of rocks. The method employs analytical modeling to simulate the destruction process of cylindrical rock samples, leveraging experimental values of four key rock properties: shear resistance limit, internal friction coefficient, external friction coefficient, and elastic modulus. The proposed method accurately determines the limit and residual strength of the rock samples using these four indicators, which can be experimentally obtained through straightforward procedures in mining enterprises. This research marks the first instance of analytically modeling the destruction of cylindrical rock samples with wedge-shaped fractures while accounting for both internal and external friction. The practical application of this method allows for the rapid assessment of stress-strain parameters in rock samples, thereby enhancing the efficiency of rock disintegration processes in mining operations.
Analytical Method for Calculation of the Strength of Cylindrical Rock Specimens during Their Longitudinal Stress
(M.S. Poliakov Institute of Geotechnical Mechanics of the National Academy of Sciences of Ukraine, Dnipro, 2023) Vasyliev, L. M.; Vasyliev, D. L.; Malich, Mykola H.; Katan, V. A.; Rizo, Z. N.
ENG: The goal of this research is to develop a method for calculating the strength of cylindrical rock specimens under axial failure. This will allow for the management of the stress-strain state of rock masses, which is an important issue for many mining companies. To achieve this goal, analytical modeling of the process of failure of cylindrical rock specimens under axial failure was carried out. This was done using experimental values of four indicators of rock properties: shear strength, coefficients of internal and external friction, and elasticity modulus. The results of this research allow for the determination of the ultimate strength and residual strength of cylindrical rock specimens using the four property indicators. These indicators can be experimentally determined using simple methods in laboratory conditions of mining companies. The scientific novelty of this research lies in the fact that analytical modeling of the process of failure of cylindrical rock specimens under axial failure was conducted for the first time, taking into account internal and external friction. This allowed for new results to be obtained and provided a basis for the development of new methods for managing the state of rock masses. The practical significance of this research lies in the fact that the proposed method allows for the determination of the ultimate and residual strength of rock specimens using four property indicators. These indicators can be experimentally determined in mining company laboratories, making the calculation results applicable for the management of the state of rock masses and the efficient destruction of rocks during disintegration. Thus, this method has significant practical significance for the mining industry. A method for calculating the strength of cylindrical specimens under longitudinal failure mode has been developed. The average convergence of calculated strength values with fс = 0.5 to experimental data is 83.4%, which corresponds to a good level of reliability for rock materials. It has been shown that the self-organization of longitudinal failure mode in cylindrical rock specimens occurs in accordance with Coulomb's criterion of maximum effective shear stress, which has been improved to account for contact friction.
Application of Physical and Quantum-Chemical Characteristics of Epoxy-Containing Diluents for Wear-Resistant Epoxy Compositions
(MDPI, Basel, Switzerland, 2025) Kulikov, Andrii; Sukhyy, Kostyantyn M.; Yeromin, Oleksandr O.; Fedak, Marcel; Prokopenko, Olena M.; Sukha, Iryna V.; Poloz, Oleksii; Mikats, Oleh; Hrebik, Tomas; Kulikova, Olha; Lopusniak, Martin
ENG: Low-viscosity epoxy-containing diluents are used to reduce the initial viscosity of highly filled, wear-resistant epoxy systems and to improve filler wetting and dispersion. This study determined physical parameters by an atomic-increment approach and electronic descriptors using the Parametric Method 3 (PM3) semi-empirical method. Clear relationships were established between the effective molar cohesion energy and the solubility parameter with van der Waals volume. Linear dependencies were also obtained between the diluent surface tension and spreading coefficients on model high-hardness fillers, including silicon carbide, boron carbide, and normal corundum. The activity of epoxy diluents depends on the lowest unoccupied molecular orbital energy. These diluents influence processing and the final physical and mechanical properties of composites, making their selection critical for strength, hardness, and wear resistance. Computational analysis enables prediction of diluent behavior, reducing experimental time and cost. Integrating physical and quantum-chemical data into epoxy diluent design accelerates the search for optimal components and improves production of durable, high-performance epoxy composites.
Automated Testing of Web Applications: Development of a System for Improving Performance and Reliability
(Ukrainian State University of Science and Technologies, Dnipro, 2025) Shvachych, H. H.; Petrenko, Vitalii O.; Myronov, D. O.; Myronov, G. V.
ENG: The research focuses on the development of an automated testing system for web applications, created using the Java programming language and modern technologies. This system enables testing at both the API and UI levels. The implementation of this solution contributes to the optimization of the testing process, reduction of errors in the production environment, and overall improvement in the efficiency, performance, and reliability of software.
Bioactive Coatings on Ti–Zr–Nb Alloy: Synthesis, Characterization and Implantology Potential
(MDPI AG, Basel, Switzerland, 2026) Kovalenko, Kseniia; Sukhyi, Kostiantyn M.; Fedak, Marcel; Rimar, Miroslav; Kalinichenko, Oleh O.; Yeromin, Oleksandr O.; Shmychkova, Olesia B.; Kulikov, Andrii; Kovalyov, Stanislav V.; Sukhyi, Mykhailo
ENG: This research reports on the properties of oxide-ceramic coatings produced by plasma electrolytic oxidation in novel electrolyte solutions for implantology applications. A series of bioactive calcium-phosphate coatings was synthesized on medical-grade Ti-13Zr-13Nb alloy using the plasma electrolytic oxidation (PEO) method. Novel electrolytes enriched with calcium and phosphorus were developed, enabling the formation of coatings with tailored physicochemical and structural characteristics. A correlation was established between the electrolyte composition and the phase composition, thickness, morphology, porosity, and microhardness of the resulting coatings. The optimum coatings exhibited a Ca/P ratio close to that of natural human bone tissue, homogeneity, a well-developed porous surface topography, and controlled resorption behavior. For the first time, a mechanism of calcium-phosphate coating resorption in a biologically active environment has been proposed. It involves partial dissolution, the formation of apatite-like surface structures, and the subsequent controlled release of Ca and P ions. In vitro testing in simulated body fluid indicated the potential bioactivity of the synthesized coatings. The proposed calcium-phosphate coatings may be considered promising candidates for future implant surface modification. The results obtained are significant for the development of advanced orthopedic and dental implants, including those fabricated using additive manufacturing technologies.
Calculation of the Probability of Test Object Compliance with the Specified Requirements and Non-Binary Decision-Making Rules
(MM Publishing s.r.o., Praha, Czechia, 2024) Rimar, Miroslav; Fedak, Marcel; Kulikov, Andrii; Bilonozhko, M. V.; Rudko, K. V.; Martynova, V. V.; Yeromin, Oleksandr O.; Savvin, Oleksandr V.; Sukha, Iryna V.; Krenicky, Tibor
ENG: The probability of test object compliance with the specified requirements and non-binary decision is a measure of how likely the test object is to meet the criteria for acceptance or rejection based on multiple factors. It is necessary to calculate by using a valid mathematical model that takes into account the test object's characteristics, the test conditions, the test criteria, and the uncertainty of the measurements. The significance of the probability of test object compliance with the specified requirements and non-binary decision can help to evaluate the quality, reliability, and performance of the test object, as well as to support decision making in complex situations.
Cavitation Nozzles with Expansion Chamber
(MM Maschinenmarkt, Czech Republic, 2022) Panda, Anton; Anisimov, Volodymyr Mykolajovych; Anisimov, Volodymyr Volodymyrovych; Pandova, Iveta; Klymenko, Anton; Ermakov, Peter
ENG: An expansion chamber for narrow part of cavitation nozzles is developed. Designs of cavitation nozzles with expansion chamber based on cylindrical nozzle and Venturi nozzle are proposed. The results of calculations of the fluid flow in the presented nozzles show the areas in nozzle, where cavitation is generated, their number, form and power. The plot of volume fraction of vapor phase shows the causes of an increase in the intensity of cavitation in new nozzles with expansion chamber. The main of them is that due to introduction of the expansion chamber, a little area of cavitation generation in the narrow part of cavitation nozzle turns to large one, that causes significant increase in cavitation intensity. The results of comparative experimental studies, which confirm the superiority of cavitation nozzles with the expansion chamber over the basic ones, show that cavitation nozzle with expansion chamber can provide 3 times higher intensity of cavitation, than basic cylindrical nozzle. Also, cavitation nozzle with expansion chamber on the basis of Venturi nozzle can provide 1.5 times higher cavitation intensity, than basic Venturi nozzle.
Characteristics of Thermal Processes in Ant Nests Built Under Stones (Hymenoptera: Formicidae)
(“Charles Darwin” Sapienza University of Rome, Italy, 2022) Stukalyuk, Stanislav; Radchenko, Yury M.
ENG: Ants prefer to nest under stones. This is due to temperature regimes favorable to the development of ant broods. In this paper, we investigated the influence of stone and ambient parameters on ant nests and created a model of thermal processes in ant nests under stones. The simulation results were compared with temperature measurements. Temperature was measured under 20 stones under different illumination conditions (sun, penumbra and shade) for 3 ant species (Myrmica rubra, Formica cinerea, Lasius niger) in Ukraine from April to August 2021. Stones were categorized as hot, warm and cold. Each stone was checked once a week for the number of workers and brood. Under two stones, tem¬perature was measured using loggers. The number of workers under hot stones in spring increased three weeks earlier than under cold and warm ones. In May-June, the maximum number of workers was recorded under hot stones. In July, the number of ants was minimal under all categories of stones. Larvae appeared under hot stones two weeks earlier than under other categories of stones. In August, the number of pupae under cold and warm stones was greater than under hot ones. Number of larvae and pupae was positively influenced by the diameter of the stone, whereas stone height did not exert an important role. Ants preferred to inhabit nests under large flat stones, which are easily heated in spring and warm the soil under them. Another important characteristic was the location of the stones. The highest brood development was noted in nests under stones in open areas well lit by the sun in the daytime. In summer ants migrated from under hot stones, because soil under it dry and warmed. Stones and their position may be important factors in accelerating the development of brood in colonies of ant species that do not have active thermoregulation.
Coefficient of Local Loss of Mechanical Energy of the Flow for a Mixture of Charge Materials
(Dnipro University of Technology, 2021) Selegej, Andriy Mikolayovich; Ivaschenko, Valeriy; Golovko, Vjacheslav Iljich; Kiriya, R.; Kvasova, Luydmila Sergijvna
ENG: Purpose. To determine the dependence of the coefficient of local losses of mechanical energy of flow of a twocomponent mixture of charge material on its depth, content of components, and average equivalent diameter of particles in the case of their freedispersed motion. Methodology. The value of the coefficient of local losses of mechanical energy was determined by the value of the hydraulic resistance of the fluid during its movement in open channels and pipes. In this paper, methods were used of comparative analysis, mathematical modeling and forecasting of dynamic processes in the flow of granular material. findings. Based on the results of theoretical studies, a mathematical model was obtained, the use of which allows calculating the coefficient of local losses of mechanical energy for the flow of a twocomponent mixture of charge materials with agglomerate particle sizes from 15 to 50 mm, pellets from 6 to 12 mm, coke from 10 to 60 mm. The developed model with satisfactory accuracy makes it possible to evaluate the movement of the charge from the indicated materials along the paths of the charging devices of blast furnaces at a speed in the range from 1.5 to 20 m/s and to determine the trajectories of the mixture of charge materials on the top with an accuracy of 0.2 m. It is noted that the calculation of the above coefficient by the known techniques is not accurate enough, which is associated with the uncertainty in the choice of a single average equivalent diameter of the particles of the two component charge. Comparative analysis of the developed model with the known models and experimental data indicates that the accuracy of calculating the dynamic parameters of a twocomponent flow of charge materials using the developed model increases by 5–10 % in comparison with calculations using the previously known models. Originality. For the first time, regularities of changes in the coefficient of internal mechanical losses of a twocomponent flow of charge materials from its depth, content of components, average equivalent particle diameters when moving along the paths of charging devices of blast furnaces have been established. practical value. Mathematical dependencies have been developed and can be used to determine the technological parameters of the charge of a modern blast furnace with different characteristics of the granulometry of the charge and the ratios of its components. This will increase the accuracy of predicting the course of the process under consideration, the degree of automation of the control systems for the technological process of the charge supply of blast furnaces, will make it possible to use expensive charge materials more efficiently, reduce energy consumption and reduce the harmful impact on the environment.
Comparison of the Reliability of Strength Limit Calculation Methods for Prismatic Samples with Different Spreading of Normal Contact Stresses in Their Wedge Failure Shape
(IOP Publishing Ltd, 2024) Vasyliev, Leonid; Vasyliev, Dmytro; Malich, Mykola H.; Rizo, Zakhar; Kress, Denys
ENG: This article explores methods for calculating the strength limits of solid objects subjected to compression. Traditionally, two stress distribution patterns are used: the exponential pattern by E.P. Unksov and the linear pattern by L. Prandtl. The authors introduce an enhanced stress distribution method. They compare the accuracy of these methods in calculating strength limits and constructing "normal stress - longitudinal strain" diagrams for wedge-shaped failures in rock samples. Four properties are considered: shear strength, coefficients of internal and external friction, and elasticity modulus. The results show that, with an external friction coefficient up to 0.3, all methods yield similar accuracy in strength limit calculations and ultimate stress-strain curves. Some curves exhibit stress drops, explained by a transition from convex to concave slip lines during failure. Additionally, there are hardening curves in the ultimate curves without theoretical justification. The comparison of calculated strength limits with experimental data confirms the method's accuracy: 13.7% error for the exponential method, 11.4% for the linear method, and 8.1% for the enhanced distribution, especially for low contact friction values (up to fc=0.3).
Components of the Collective Agreement on Labor and Social Security of Employees of a Legal Entity
(Publishing Group "Scientific Perspectives", Kyiv, 2025) Makhova, Liliia; Vyprytskyi, Andrii O.
ENG: This article is the first in a theoretical study of labor law and social security law, which examines the content of a collective agreement in the context of social security for employees of a legal entity. The scientific work explores the theoretical and practical problems of the collective agreement regarding the social security of workers and offers some recommendations for improving the current legislation of Ukraine. Increasingly, in Ukraine, there is a certain development of contractual regulation of legal relations of social security of employees, which is applied without specific measures of influence on employers. Labor law and social security law have a dualistic content of legal regulation. These branches of law contain public and private influence on the legal relations of employees, that is, individuals and legal entities - employers. Now we see that labor law and social security law provide an opportunity to emphasize such a method of legal regulation of these branches, which combines the state and contractual method of legal regulation of labor and social security relations. It would be appropriate to consider collective agreements in labor law and social security law as specific agreements and regulatory acts of the state. The article provides a definition of collective agreements in the regulation of social relations, in terms of additional social protection of employees or their family members, increasing the amount of one-time or permanent social payments provided for by law. It was found that to restore the proper level of social security for employees and their family members, it is necessary to introduce mandatory funded social security as an additional element of guarantees for overcoming social risks, with the aim of forming social savings.
Creative Methods as an Obligatory Component of the Technical Specialists Education in the Post-Industrial Era
(Faculty of Organization and Management at the Silesian University of Technology, Silesian Voivodeship, Poland, 2024) Molokanova, Valentyna M.; Petrenko, Vitaliy O.; Kuznetsov, Valeriy; Kuznetsov, Vitalii V.; Krol, Agnieszka; Kacprzak, Marzena; Wielewska, Izabela; Wyrzykowska, Barbara
ENG: Purpose: The article's objective is formalization of the model, the main stages and creative methods of training technical specialists, the definition of features and directions for further education development in the post-industrial era. The article is aimed at revealing the nature of creativity, highlighting the essence of the functions of methods of creative activity and their importance for students of technical specialties. Design/methodology/approach: The work uses critical analysis of scientific and methodological sources, system and convergent analysis methods, generalization and systematization of practical experience. The method of convergent generalization made it possible to identify key indicators of the model of creative competencies. The conceptual model of creative competence was developed based on the results of cooperation on the frame of master's programs for the project managers training. For the practical part of research, a qualitative method was used (participant observation, individual interview, tests). Findings: The need to train technical specialists in the methods of creative search using modern technologies, which allows to achieve the effects of the intellectual potential development for the individual, the state and society, is justified. An experiment on training project managers of two Ukrainian institutes in creative technologies proved the feasibility of implementing such training. Based on the calculation of the creative competencies’ development of the first- and second-year study technical specialists, the need to add a mandatory creative component to educational programs has been determined. Implications/Recommendations: To assess the quality of training, a methodology for assessing the level of competence has been applied. This made it possible to identify a low level of some competencies and, at the stage of improving the curriculum, plan the necessary corrective actions for the development of weak components of competencies. Since project-oriented learning is used, the model is similar to the model of the classical project life cycle and will be especially useful in the implementation of innovative projects in production. The article presents a framework for teaching students creative competence, which can be used by other educational institutions. Originality/value: The review of literary sources proved that so far very little attention has been paid to the development of creative competencies in students of technical specialties, although these competencies will be the competitive advantage of a person in the competition with artificial intelligence. The model of creative competencies for the technical specialists training is presented, which is divided into four areas, which in turn are divided into four components. These areas relate to the sampling and systematization of knowledge; adaptation to user requirements; awareness and dissemination of hidden knowledge; transition to the active use of knowledge.
Design of a Sample Cooler with Minimized Pressure Drop and High Cooling Efficiency
(MM Science Journal, Czech Republic, 2026) Rimar, Miroslav; Kizek, Jan; Oravec, Peter; Fedak, Marcel; Bialik, Wojciech; Gres, Leonid P.
ENG: This paper addresses the design and thermal–hydraulic analysis of a heat exchanger designed for cooling sampled process air from a fermenter prior to its transport to a mass spectrometric analyzer. Due to the high humidity of the sampled air, effective cooling is required to prevent unwanted condensation during transport over a distance of 200 m. A tube-in-tube counter-current heat exchanger was selected and analyzed with respect to heat transfer, condensate formation, cooling water demand, and pressure losses. The results show that the proposed design achieves the required outlet air temperature with a minimal heat transfer area and acceptable hydraulic losses. Although the amount of condensate is low, periodic purging of the air-side tube is recommended to prevent a reduction in heat transfer efficiency. The proposed solution provides a reliable and efficient method for conditioning humid process air in fermenter monitoring applications.
Determination of Operating Parameters of Accumulative Electric Heating Systems
(IOP Publishing Ltd, 2024) Kolienko, Anatoliy G.; Ahmednabiev, R. M.; Gupalo, Olena V.; Demchenko, O. V.; Hukasian, O. M.
ENG: The article presents the results of research aimed at determining the parameters and characteristics of storage heating systems, justifying the possibility of using heat accumulators to increase the efficient use of energy that is generated, including from renewable sources. The virtuality, frequency and significant dependence on natural conditions and climate of renewable energy sources, as well as the need to optimize their installed capacity, leads to the need to use energy storage installations. The presence of efficient energy batteries is a prerequisite for modern efficient energy and heat supply systems. The methodology of the work is based on our own theoretical and experimental studies, which provide practical recommendations for the arrangement of energy accumulators obtained using renewable heat sources. This is especially relevant for Ukraine during the period of active military operations on its territory, the destruction of traditional energy sources and a shortage of generating capacity. Recommendations have been developed for the design of heat accumulators for heating systems of residential and public buildings. Their effectiveness has been assessed under conditions of limited use of fossil fuels and the use of hybrid energy sources. Scientific and practical results of the work make it possible to carry out low-cost reconstruction of heating systems for the introduction of storage systems using electrical energy, the source of which is wind and solar energy. Such developments are becoming particularly relevant in Ukraine, taking into account the requirements for ensuring the stability and efficiency of infrastructure facilities in war conditions.
Determination of Particular Relative Reduction in Cold Rolling of Thin and Extra Thin Strips to Implement the Process with the Least Force
(National Academy of Sciences of Ukraine, Publishing House Akademperiodyka, 2022) Vasilev, Ya. D.; Samokish, D. N.; Bondarenko, Oksana A.; Mospan, N. V.
ENG: Introduction. It has been theoretically established and experimentally confirmed that the elastic deformations of rolls and strips in cold rolling have a significant and, in the case of thin rod rolling, a crucial effect on all process parameters. Problem Statement. The influence of the elastic-plastic interaction of a thin strip with rolls, the tension, the temperature and rate of deformation, and the strength of strip material shall be taken into account for developing a modern theory of longitudinal cold rolling. Purpose. Modeling and forecasting the parameters of cold rolling of thin and extra thin strips. Materials and Methods. To solve this problem, the conditions of rolling strips made of 08kp steel with different degrees of preliminary metal hardening, which reflected the features and regularities of hardening the strip material in the multicellular state line, have been modeled. The partial relative reductions vary within 0.02—0.35, with the initial data corresponding to the most characteristic conditions of cold rolling of thin and extra thin steel strips on operating mills taken. Results. The quantitative data on the influence of the strip thickness, at the entrance to the deformation zone, partial and preliminary relative reduction during cold rolling on the process conditions with the least force. For the first time, the conditions and range of partial relative reductions for the cold rolling process of thin and extra thin strips with the least force have been determined. It has been established that in the case of cold rolling of thin and extra thin strips made of unriveted and pre-hardened steel, varying partial relative reductions within the range from 0.1 to 0.30—0.35 provides the realization of process with the least force. Conclusions. The implementation of cold rolling process with the least force is advantageous in terms of energy saving and manufacturability, as it allows reducing the specific consumption of electricity and expanding the range of cold rolling mills for smaller thicknesses of rolling strips and indicates the need to determine conditions for such a process.
Determination of the Critical Cyclic Fracture Toughness for the Mode II in Mixed Fracture of Structural Steels
(Elsevier Ltd., Oxford, 2023) Belodedenko, Sergii V.; Hrechanyi, Oleksii M.; Vasilchenko, T.; Hrechana, A.; Izhevskyi, Y.
ENG: The developed method of processing experimental data from tests performed according to the four-point asymmetric bending scheme made it possible to establish the coefficient of proportionality between the modes of failure I and II, which for structural steels is in the range of 2,5÷3. The established longevity before the appearance of the critical speed according to the developed models is within the limits of the natural dispersion inherent in fatigue failure, which indicates the effectiveness of the developed algorithm and the correctness of the determined indicators of resistance to failure. The problem of the appearance of an oblique crack during tests on four-point asymmetric bending has been solved. It can be assumed that about 90% of the growth of an oblique crack is caused by the contribution of the mode of failure II.
Determining the Thermally-Stressed State of Motor-Driven Bowls for Transporting Liquid Slag
(РС ТЕСHNOLOGY СЕNTЕR, Kharkiv, 2024) Povorotnii, Viktor V.; Shcherbyna, Iryna V.; Zdanevych, Serhiі V.; Diachenko, Nina K.; Kimstach, Tetiana V.; Solonenko, Lyudmila I.; Usenko, Ruslan V.
ENG: Slag bowls were chosen as the object of research, as important components of blast furnace, steelmaking, and ferroalloy shops of metallurgical enterprises. The main problem of operation of any slag trucks is their limited durability and frequent destruction of slag bowls. The reason for these problems is changes in the shape of the bowls during operation, manifested in the formation of narrowing places in the area of the support ring – for rail-mounted bowls, destruction of supporting pins – for rail-mounted slag trucks, or cracks in the walls. Those defects appear as a result of cyclic thermal effects of liquid slag on the bowl. Based on the results of computer simulation, it was established that the main role in the destruction of the support pins of motor-driven slag bowls belongs to temperature changes. The temperature stresses arising in the bowl are localized in the area of the slag mirror (200–250 MPa for 25L steel, 280–350 MPa for 30HML steel). The results provide grounds for improving the presented slag bowl to reduce temperature stresses in its walls and structures of the supporting trunnions. The results reported here are explained by the fact that with uneven heating of elastic bodies, temperature stresses appear, which, under certain configurations of temperature loads, lead to the destruction of structures. The findings from these studies are recommended to be used at enterprises for the design and manufacture of slag bowls, as information on the localization of dangerous places of the structure. In addition, the data presented here could be useful for metallurgical enterprises for detailed technical diagnosis of bowls in their dangerous places.
Development of a Mathematical Model for the Energy Balance of the Laser Cladding Process of Metallic Powders with a Coaxial Nozzle
(MM Publishing s.r.o., Praha, Czechia, 2024) Karakash, Yevhen O.; Rimar, Miroslav; Karpovych, Olena; Zhumar, Denys; Kizek, Jan; Fedak, Marcel; Kulikov, Andrii
ENG: Modern technologies require innovative solutions for producing complex structures from various materials. Additive manufacturing (AM) or 3D printing presents such a challenge and has significantly impacted the environment across manufacturing sectors, regardless of size. Researchers and technicians have developed new design approaches by exploring fundamental components, materials, and manufacturing processes beyond traditional frameworks, addressing global complex material and design challenges. Laser cladding of metal powders with a coaxial nozzle is one such technology, offering highly productive processes for large-scale component production. Fiber lasers are optimal for providing laser radiation, ensuring required emission quality and stability. The authors seek to develop a mathematical model for the energy balance of coaxial laser cladding of metal powders, aiming to provide an overview of energy consumption levels and unit characteristics for powder delivery, inert gas, and laser radiation sources in direct metal powder coating setups.
Development of a Methodology for Mechanical Testing of Steel Samples for Predicting the Durability of Vehicle Wheel Rims
(Elsevier B.V., 2023) Belodedenko, Sergii V.; Hrechanyi, Oleksii M.; Vasilchenko, T.; Baiul, Kostiantyn V.; Hrechana, A.
ENG: The reliability and durability of parts of aggregates and mechanisms of motor vehicles depend on the efficiency of the basic and responsible load-bearing structures. The responsible elements of the motor vehicle are the wheel rims, whose reliability will increase the energy efficiency of the motor vehicle as a whole. One of the directions for increasing the reliability of wheel rims is the use of optimized low-pearlite steels with the increased impact strength of the 10HFTBch type. When determining the mechanical characteristics of steels with increased impact strength, it is worth considering a mixed form of failure; therefore, the scheme of four-point asymmetric bending is optimal for laboratory research. Conditions of mixed failure for an oblique crack lead to a 25–45% decrease in the value of ΔКІm* relatively to the stress intensity factor ΔКІ* obtained for the pure I mode. The same can be said about the II mode, when ΔКІІ* determined during the growth of an oblique crack is 10% smaller than the value of ΔКІІ*, which is calculated for the pure mode of failure, This indicates an increase in the fatigue crack growth rate for mixed failure compared to pure modes.
Development of Stabilization Measures Aimed at Removing Zinc with Smelting Products and Accumulating Titanium in the Hearth of a Blast Furnace
(John Wiley & Sons, Ltd., 2024) Semenov, Yurii; Horupakha, Viktor; Vashchenko, Serhii; Khudyakov, Oleksandr; Shumelchyk, Ievhen; Baiul, Kostiantyn V.
ENG: This paper presents the results of the development of stabilization measures aimed at the removal of zinc with the products of melting and accumulation of titanium in the hearth of a blast furnace. The relevance of the development and use in practice of such measures is due to the unstable fuel and raw materials conditions for the production of cast iron, when their stabilization is a complex and difficult task, as well as the need to extend the campaign of blast furnaces during the overhaul period. The negative effect of zinc oxides on the condition of the blast furnace shaft lining, accompanied by slab formation, and the overconsumption of specific coke consumption, which occurs when zinc circulates in the volume of the blast furnace, require measures to remove zinc from the smelting products. The article proposes such measures, which consist of flushing according to the proposed schedule during the operation of the blast furnace at planned blowing parameters and with the provision of the necessary thermal reserve. In order to lengthen the campaign of a blast furnace, one of the most common methods for protecting the hearth lining is the periodic introduction of titanium-containing materials into the charge of blast furnaces. The entry of titanium oxides into the furnace, as a rule, is ensured by the use of concentrate or specially prepared ilmenite briquettes with a high titanium content as part of the sinter charge, which can be introduced directly into the composition of the blast furnace charge. The article analyzes the experience of using titanium-containing materials as part of a blast furnace charge and formulates measures to intensify skull formation in the hearth.
Effect of Urban Habitats on Colony Size of Ants (Hymenoptera, Formicidae). In Memory of Professor A. A. Zakharov (Russian Academy of Sciences, Moscow)
(Turkish Academic Network and Information Center, 2022) Stukalyuk, Stanislav; Akhmedov, Ascar; Gilev, Alexey; Reshetov, Alexander; Radchenko, Yuri M.; Kosiuk, Nataly
ENG: Urbanized ecosystems are suitable for the habitat of only a few species of ants, due to conditions caused by human activities. Invasive species of ants have adapted to urbanized ecosystems most successfully. The study of the ant colonies sizes started in Crimea in 2013–2014. In 2019–2021 it was carried out in Ukraine (the Carpathians, Kyiv city, and Kyiv region), in Russia (Rostov-on-Don city and region, and the Urals), and in Uzbekistan (Tashkent city, and tugai forests). The study covers natural (forest, meadow, steppe), suburban (alleys and tree planting) and urban habitats (tree planting along streets and roads, botanical gardens). Our study covers 21 species of ants with trails on forage areas. Nine species were sampled for interspecific comparison of colony sizes. They were collected in at least 2 habitat types within the same geographic region. According to the activity parameter on the trails, the number of foragers and the population of the colony were calculated (using the formula of A. Zakharov). According to our calculations, the maximum colony sizes are typical for invasive species (Crematogaster subdentata, Lasius neglectus, 100–7500 thousand workers) in the urban habitats. Some native species (Dolichoderus quadripunctatus, Formica cinerea) in the urban areas have colonies with 120–350 thousand workers. These values may exceed those for ant species inhabiting natural habitats (30–250 thousand workers). High rates of colony size in the urbanized habitats can be achieved due to availability of food, nesting resources, and the absence of competing ant species.
The Empirical Study of the Correlation between the Dominant Strategy of “Inflexible Hippos” and the Organizational Life Cycle
(Alfred Nobel University, Dnipro, 2024) Hordieieva, Inna O.; Nezghoda, Olga
ENG: The development of companies is characterised by the adoption of certain stages of business development, the availability of resources and outcomes. This developmental process is inherently cyclical, requiring companies to remain flexible and adaptive continuously. Each phase of the life cycle is characterised by unique challenges, perspectives and inherent features that require strategic modifications to maintain and enhance competitiveness. A holistic interpretation that integrates both life cycle phases and strategic approaches is necessary for a thorough understanding of a company’s success and market performance. The purpose of this paper is to explore the correlation between the dominant strategy employed by industry leaders, known as “inflexible hippos,” and the various stages of the organizational life cycle. The research objects are the dominant strategy “inflexible hippos” and the ten phases of the organizational life cycle: Courtship, Infant, Go-go, Adolescence, Prime, Maturity, Aristocracy, Early bureaucracy, Bureaucracy, and Death. The subject of the research is to verify the existence of a connection and its type between the research objects. The objective of the study is to ascertain the existence and nature of the connection between these research objects. The research methodology employed morphological, analytical, statistical assessment, and comparative analysis techniques. By comparing morphological statements formulated with expert input, evidence was found regarding the existence and significance of the correlation strength. The study revealed that the correlation between competitive strategy and the phases of the company’s life cycle is strongest in the “Maturity” and “Aristocracy” phases, which dictate the sequence of organizational development. The tightest connection with direct independent mutual influence is observed in the “Go-Go”, “Adolescence”, “Prime”, “Reconstruction”, and “Bureaucracy” phases. The context dependence of this correlation characterizes ongoing change processes: the company retains old features of organizational development while simultaneously acquiring new ones. Evaluating the timeliness and efficiency of managerial decision-making based on the alignment of competitive strategy with the company’s life cycle, influenced by both external and internal factors, is a critical stage in the company’s development process. This study can help companies to develop more effective competitive strategies that respond to their current needs. This can lead to improving companies’ competitiveness, selecting appropriate and effective project actions and their success in the market.
Energy and Technological Modelling of Metallurgical Processes from Out-of-Furnace Iron Processing to Continuous Casting
(Baltija Publishing, Riga, Latvia, 2023) Stoianov, Oleksandr M.; Petrenko, Vitalii O.; Niziaiev, Kostiantyn G.
ENG: Purpose. Conducted energy-technological modeling of steelmaking processes. It is shown that at different stages of steel production, the increase in energy intensity of steel differs significantly and depends on the chosen technology, equipment and materials used. It has been established that for modern methods of off-blast refining of cast iron, the least energy-consuming technology is the use of mixtures based on lime and magnesium. For the oxygen-converter process, liquid cast iron contributes the largest increase in energy consumption, and for conditions of non-furnace processing of steel, the consumption of electricity for heating the metal. An assessment of the impact of the speed of steel pouring on the MBLZ and the carbon content in the metal on the energy costs of the process is also given.
Engineering Safety in the Aspect of the Safety and Security Civilization
(Maximum Academic Press, 2025) Belodedenko, Sergii V.; Bilichenko, Galyna M.; Rassokhin, Dmytro
ENG: The present article is devoted to the methods of quantitative risk analysis used to ensure the engineering safety of industrial equipment. It aims to clarify the latter's place in the concept of the civilization of safety and security. The features that make engineering universal in engineering are its interdisciplinary nature and the presence of a safety culture. Interdisciplinarity is manifested when considering organizational and legal factors for risk assessment. This is demonstrated by the example of two blast furnace accident scenarios. The safety culture is implemented through initiative-taking maintenance strategies through risk-based maintenance. The theoretical foundations of this strategy are presented: risk and safety indicators, an algorithm for finding the optimal level of risk, and a method for diagnosing the technical condition of mechanical systems. Recommendations on using risk and safety indicators depending on the criticality of the element being diagnosed are given.
Estimating the Residual Resource of Basic Structures Using a Model of Fatigue Durability under Complex Loading
(PC TECHNOLOGY CENTER, Kharkiv, 2022) Belodedenko, Sergey V.; Hrechanyi, Oleksii M.; Hanush, Vasyl I.; Vlasov, Andrii
ENG: This paper reports the construction of a durability model of basic structures, which takes into consideration the complex stressed state under the cyclic action of the complex load. The models that take into consideration this factor are categorized on the basis of equivalent for a certain indicator of the stressed-strained state. The equivalence models based on the tangent stresses and strains have been recognized as the most effective ones. However, they hold when the ratio of the limits of fatigue under tangent and normal stresses exceeds 0.5. In addition, determining the latter requires specific testing equipment. The concept of basic bearing structures for industrial equipment has been formulated. The issue related to the multi-axis fatigue of basic structures was considered from the standpoint of combining the reliability indicators of systems. The durability model has been derived from the rule of combining resource safety indices. The load is represented as a combination of individual subprocesses of simple types of deformation with their amplitudes and asymmetries. A model of durability with multi-axis fatigue has been built, which takes into consideration the parameters of the form of the strain cycle, and the type of process (synphase, disproportionate, unchanging static stress). The possibility of obtaining parameters for the multi-axis fatigue model during tests for three-point bending under conditions of varying the multiplicity of the span has been confirmed. According to this scheme, fatigue tests of prismatic samples of the steels 09G2 and 40H were carried out. For them, the parameters of fatigue resistance were found; additionally, the ratio of the fatigue limit for tangent stresses of displacement and fatigue limits for normal bending stresses, which is equal to 0.385, was established. A test procedure has been devised to determine the initial data for the multi-axle fatigue model, which is suitable for conventional test machines and simple-shape samples. The latter advantage is important precisely for basic structures, from fragments of which it is difficult to fabricate a sample of a complex shape.
Experimental and Analytical Ways of Finding the Function of the Maximum Accumulated Damage under Operating Modes with Overloads
(Elsevier B.V., Amsterdam, Netherlands, 2024) Belodedenko, Sergii V.; Hrechanyi, Oleksii M.; Hanush, Vasyl I.; Izhevskyi, Y.
ENG: The problem of overloading was characterized as a factor of load history in the modern resource assessment methodology. The signs by which a loading cycle can be considered an overload were defined. A correlation was obtained between the failure mechanics approach and the damage accumulation approach to survivability prediction. An experimental and analytical method of its adjustment has been developed based on the regularities of the impact of loads on the accumulated damage. Its use in obtaining models of damage accumulation in 40Cr and 35CrMnSi steels was shown. New experimental data were obtained on the behavior of the accumulated damage function in the stress localization zones during bending, and an explanation of its non-monotonicity under the influence of operational factors was found.
Experimental Verification of the Survivability Model under Mixed I+II Mode Fracture for Steels of Rolling Rolls
(Springer Cham, 2022) Belodedenko, Sergii V.; Hanush, Vasyl I.; Hrechanyi, Oleksii M.
ENG: The model of fatigue mixed fracture, which follows from the amalgamation rule of resource safety indices, has been experimentally confirmed. It does not require finding an effective SIF, but is based on the construction of survivability curves for pure modes. Survivability in a mixed process is defined as the result of combining individual fracture processes. Peculiarities of steels of rolling rolls fracture under conditions of cyclic deformation according to the scheme of four-point asymmetric bending are revealed. Although such a test scheme is designed to obtain the fracture of the II mode, in existing studies, this has not been achieved. The crack from the notch, practically, immediately went away at an angle ~45° toward the tensile zone, which indicates a mixed I+II fracture. With sufficient accuracy to predict survivability, the exponent of the Paris’s region of the fatigue crack growth diagram (FCG) can be taken as nI = 4 (I mode), nII = 3 (II mode). As a parameter of schematization, it is possible to use the value of SIF at an FCG rate of 10–7 m/cycle. Its value for steels of rolling rolls can be 60–70 MPa√m in mode I. For mode II, this index decreases by 2.5–3 times.
Explanatory Model for the Evaluation of Investment Projects
(Kharkiv National University of Radioelectronics, Kharkiv, 2023) Bushuiev, K. M.; Savchuk, Larysa M.; Fonarova, Tetiana A.
ENG: Theoretical and practical issues of constructing an explicative model for assessing investment resources in the process of supporting investment decision-making at modern enterprises, which are based on both classical economic and expert assessment methods using a neural network as a modern technology of artificial intelligence, have been studied.
Fatigue Behavior of Steels for Critical Members and Durability Models with Stress Ratio Growth
(Elsevier B.V., 2026) Belodedenko, Sergii V.; Hrechanyi, Oleksii M.; Scherbinin, M.
ENG: The use of high-strength steels allows you to reduce the weight of the object, increase reliability and safety. Authors offer a new interpretation of critical members based on risk analysis and the concept of safety. Their performance determines the level of losses during the operation of mechanical systems. Critical members made of high-strength steels can be subjected to cyclic loading with a high stress coefficient. Known disadvantage of high-strength steels is their vulnerability to most impact factors, including cyclic loading with high cycle asymmetry. Cylindrical samples of heat-treated steels 09Cr16Ni4Nb and 13Cr15Ni4NМо3 were tested for tensile fatigue. Test results were presented in the form of a durability equation. Smith charts in relative stresses were obtained by simple transformations from a durability equation. Obtained charts showed a somewhat anomalous concave shape instead of an expected convex. This indicates a loss of sensitivity to mean stresses at high cycle asymmetry. Authors explain this phenomenon from the point of view of combining the concepts of fatigue and fracture mechanics. Model of a durability equation is proposed based on the concept of combining fracture mechanics and fatigue methodology. Its application in practice is a priori and requires assigning only one parameter in the form of the slope of the S-N curve.
Fatigue Lifetime Model under a Complex Loading with Application of the Amalgamating Safety Indices Rule
(Elsevier B.V., 2022) Belodedenko, Sergii V.; Hanush, Vasyl I.; Hrechanyi, Oleksii M.
ENG: The problem of multiaxial fatigue is considered from the standpoint of amalgamating indicators of system reliability. The lifetime model is derived from the rule of amalgamating resource indices of safety. The load is represented as a combination of individual subprocesses of simple types of deformation with their amplitudes and stress ratio. A model of lifetime in multiaxial fatigue has been developed, which takes into account the parameters of the deformation cycle shape, the type of process (inphase, disproportionate, constant static stress). The possibility is confirmed for obtaining the parameters of the model of multiaxial fatigue when tested for three-point bending under conditions of variation of the multiplicity of span. According to this scheme, fatigue tests were performed for prismatic steel samples 09G2 and 40Н. The fatigue resistance parameters were found for them, and also there were found the ratio of the fatigue limit for tangential stresses and the fatigue limit for normal bending stresses, which is equal to 0.385.
The Features of Fatigue Resistance of Critical Members Steels under High Stress Ratio
(Elsevier B.V., 2026) Belodedenko, Sergii V.; Bilichenko, Galyna M.; Hanush, Vasyl I.; Hrechanyi, Oleksii M.
ENG: From the standpoint of risk analysis and the concept of safety, the authors propose a new interpretation of critical members. Their performance determines the level of losses during the operation of mechanical systems. Therefore, it is advantageous to make critical members from high-strength steels that are sensitive to most influencing factors. Elements made of high-strength steels suffer from cyclic load with high stress ratio. In this aspect, cylindrical samples of heat-treated 09Cr16Ni4Nb and 13Cr15Ni4Мо3 steels were tested for tensile fatigue. The test results were presented in the form of a lifetime equation. Smith diagrams in coordinates were obtained by simple transformations from lifetime equation. These graphs showed a slightly anomalous concave shape instead of the expected convex shape. This indicates a loss of sensitivity to mean stress at high stress ratio. The authors explain this phenomenon from the standpoint of the merging of fatigue and fracture mechanics concept. Interestingly, a similar form was obtained for the graph of the dependence of the critical cyclical SIF on stress ratio. That is, the sensitivity of cyclic toughness to the value of the stress ratio decreases as it increases.
Features of Legal Regulation of Artificial Intelligence Using the Example of the European Union
(Ukrainian State University of Science and Technologies, Dnipro, 2026) Vyprytskyi, Andrii O.
ENG: The article examines the prerequisites for the emergence of legal regulation, provides examples of the emergence of the first ethical standards for regulating artificial intelligence, and demonstrates how these standards were implemented in the recently adopted Artificial Intelligence Act. It also examines the prospects for legal regulation of artificial intelligence systems.
Forecasting the Properties of Linear Block-Copoliurethanes Based on Oligoesters of Regular Structure
(Ukrainian State University of Chemical Technology, Dnipro, 2021) Anisimov, Volodymyr Mykolajovych; Anisimov, Volodymyr Volodymyrovych
ENG: We showed that the development of recommendations for a reasonable choice of linear block copolyurethanes that would be optimal for given operating conditions is still intuitive and does not consider the features of the molecular structure and the nature of initial components. We suggested a new scientifically grounded approach to the creation of linear block-copolyurethanes with increased wear resistance in relation to strength, deformation, thermophysical and tribotechnical characteristics. To simplify analysis of the properties of the studied materials, a mathematical model was developed, which describes the relationship between all considered properties of materials and their structure. We proposed to assess the relationship between structure and properties of the investigated materials by using quality indexes. Maximum values of quality indexes, depending on the operating conditions, correspond to different contents of hard blocks (Pc), and, consequently, to different molecular structure of the studied polyurethanes. Thus, it is reasonable to use block-copolyurethanes based on OBGA500 with a maximum content of hard blocks (Ðñ>60%) for operating conditions where it is necessary to provide high strength characteristics. Polyurethanes synthesized with the formation of clusters of hard blocks in the range of 45–55% are recommended for the use as wear-resistant materials.
Formation of an Optimal Portfolio of Venture Projects
(Dnipro University of Technology, 2021) Korhina, Inna A.; Petrenko, Vitaliy O.; Khomenko, Volodymyr L.; Kulyk, Volodymyr O.
ENG: Purpose. Development of a method for forming an optimal portfolio of venture projects taking into account risks, uncertainty in initial data and limited financial resources. Methodology. To calculate the accuracy of forecasting prices, which are necessary for calculating the parameters of the stochastic optimization model for the formation of a portfolio of projects, we used the theory of random variables and regression analysis. The problem of choosing the optimal portfolio of venture projects was solved using stochastic mathematical programming. Findings. A model for creating an optimal portfolio of venture projects has been developed. It is a stochastic mathematical programming model that can be used to solve problems of investing in venture projects in the extractive industry. This model takes into account the risks associated with obtaining the expected income from the implementation of each venture project, the uncertainty in the initial data for calculating the income from the projects selected in the portfolio, as well as the limited funds required to finance the project portfolio. Originality. The stochastic optimization model for the formation of an optimal portfolio of projects, taking into account the peculiarities of venture projects, in particular, their high riskiness, has been significantly improved and adapted. Practical value. The proposed model for the formation of an optimal portfolio of venture projects can be used at mining enterprises, whose development strategy involves the implementation of innovative, high-risk projects. The use of this model in strategic planning will allow an enterprise to receive the maximum income from venture projects in the face of a lack of financial resources, as well as instability of the innovation market.
Formation of Investment Attractiveness of Intellectual Capital of Engineering Companies in the Context of Improvement of Innovation Activities Management
(European University Press, ISMA University of Applied Sciences, Riga, Latvia, 2024) Bushuiev, M.; Fonarova, Tetiana A.; Petrenko, Vitalii O.
ENG: The study examines the formation of investment attractiveness of intellectual capital of engineering companies in the context of improving their innovative activities. Market conditions and problems of the engineering services segment are studied, the need for domestic engineering enterprises to comply with the international regulatory framework is emphasized. The need to build modern marketing information systems as an element of increasing the intellectual capital of the company and the marketing activity of engineering companies in increasing the commercial potential of innovative technologies is substantiated. It is proposed to use modern technologies for managing innovation activities, such as design thinking, organizational laws adapted to the specifics of engineering using the capabilities of project management, and the latest methods of personnel training. The directions of forming the intellectual capital of engineering companies are studied. Directions for investing in the intellectual capital of an enterprise providing engineering services are developed. The organizational capital of engineering companies, conditions and factors for its increase are studied.
Forming the Investment Attractiveness of Innovative Investment Projects on the Basis of Increasing Their Commercial Potential in the Field of Engineering Services
(European University Press, ISMA University of Applied Sciences, Riga, Latvia, 2023) Fonarova, Tetiana A.; Bushuiev, M.; Petrenko, Vitalii O.; Bushuiev, K. M.
ENG: The study deals with the formation of the investment attractiveness of innovative projects in the activities of Ukrainian enterprises with the involvement of engineering companies. The necessity of coordinating the goals of the enterprise and the motives of investors is substantiated. It is noted that the basis for cooperation and pooling of efforts can be the determination of an integral indicator of investment attractiveness – the commercial potential of an innovation-investment project. Modern approaches, the essence and components of the formation of commercial potential are considered. The role and importance of engineering companies in increasing the commercial potential of innovative and investment projects is shown on the example of the innovative technology «Simatic System Audit» of Siemens Corporation. The marketing component in increasing the commercial potential of an innovation-investment project has been studied. The role and importance of engineering companies in promoting this technology to the Ukrainian market of industrial enterprises is emphasized.