Kryvyi Rih National University
Recent publications
This article presents the results of the research on real coal charges of different compositions intended for coking with loading into the chamber by the stamping method. The results of the study established that with an increase in the content of coal at a low stage of metamorphism and a decrease in the content of coal at a high stage of metamorphism in the charges, a decrease in the quality indicators of the coke obtained from them leads to a decrease in the yield of coke. At the same time, there is a gradual decrease in the compaction of the charges from 22.5 to 21.1 kPa; their expansion pressure decreases from 6.8 to 5.9 kPa; and the work of stamping decreases from 8966 to 6822 J. It was also discovered that with the increase in the degree of grinding of the charge, and, accordingly, with the decrease in the average diameter of its particles, the work of stamping coal charges decreases from 7407 to 6238 J. The results can be used in the manufacturing of blast furnace coke by stamping coal charges.
The paper is devoted to the key elements of forming a system of anti-crisis approaches in project analysis. The conceptual apparatus has been clarified, such as the project risk, the anti-crisis framework in the entry system, and the model of several activities (EERC). With respect to the importance of factors of insignificance and risk in project analysis, emphasis is placed on current institutional trends in the development of anti-crisis project management systems as part of the implementation of the «blue ocean” strategy. Among the risks in the implementation of the "blue ocean" strategy, the following are highlighted: (1) cognitive barriers: difficulties in changing established processes and company culture; (2) resource limitations: lack of funds for the development and promotion of innovations; (3) organizational inertia: resistance to changes within the company; market risks: uncertainty of demand for a new product or service; (4) competitive pressure: rapid copying of ideas by competitors. Project risk management processes are reduced to a number of consecutive stages: (1) risk management planning; (2) identification of risks; (3) qualitative and quantitative risk analysis; (4) planning preventive measures to respond to risks; (5) risk monitoring and management. Strategies that can be adopted within the framework of the system of anti-crisis measures: (1) own retention or acceptance of risks; (2) harmonized management; (3) risk transfer strategy. If the risk factor is implemented by the neutralization program, it is assumed that alternative management methods are used, among which should be mentioned: Wald (maximine) criterion, Savage's minimax risk criterion, Hurwitz's pessimism-optimism criterion, Laplace's criterion, Bayes' criterion. The probabilities of different states of the environment are not equal, and their values are determined by an expert. Attention is focused on the fact that the methods of modeling, forecasting and expertise are expediently used to identify inconsistencies in the given parameters of the project, as well as to assess the viability of the anti-crisis system.
This paper sets the task of researching ways to improve the management of financial resources of a business entity using the example of ArcelorMittal Kryvyi Rih. The paper identifies the main areas of optimization of financial decisions, strategic planning and risk management in conditions of market instability and resource scarcity. In the process of research, methods of scientific abstraction, structural-decompositional analysis and synthesis, logical generalization, cause-and-effect relationship, logical-prognostic, meaningful-comparative were used to meaningfully reveal the essence of the problem. The novelty of the paper consists in a systematic approach to the management of financial resources in the conditions of the economic crisis and the risks of the world steel market. In particular, the work examines the use of new financial instruments for diversification of financing sources, the use of hedging to reduce currency risks, and the implementation of environmentally oriented projects that increase the sustainability of the enterprise. The practical significance of the paper consists in the development of specific recommendations for optimizing the management of financial resources, which can be useful for managers of companies in the metallurgy industry. The proposed solutions help strengthen financial stability, improve liquidity and ensure efficient use of capital in conditions of limited access to resources and unstable prices for raw materials. The paper presents the practical results of optimizing the management of financial resources using the example of ArcelorMittal Kryvyi Rih. Key aspects of financial planning, liquidity and risk management are considered, as well as examples of attracting profitable financing for environmental projects are analyzed. The results of the paper show that strategic financial management enables the company to remain competitive even in crisis conditions. The problem of improving the management of financial resources is one of the key ones in the modern conditions of an unstable economy. It is related to scientific tasks, such as the development of new models of financial planning and risk analysis, as well as to practical tasks, such as ensuring financial stability, increasing profitability and reducing financial costs. Analyzing modern publications on the management of financial resources, one can note the growing interest in risk management issues, the use of financial instruments to reduce risks and optimize the capital structure. In particular, scientific works devoted to the metallurgical sphere emphasize the importance of diversification of funding sources and liquidity management in conditions of unstable markets.
The article discusses the theory and practice of development in the field of separation and extraction of metals at mining and metallurgical enterprises through the creation and implementation of mine and bunker vibrating feeders, vibrating screen feeders and new designs of screening surfaces for them, as well as devices for eliminating buildup in bunkers. New scientific and practical results of research on the substantiation of improved vibrating machines for auxiliary mining operations are presented, including: vibrating mining feeders of the PVG type; vibrating hopper feeders such as PVB and ZhVB; vibrating feeders-screens of the PGV and GPV types; sifting surfaces for them; devices for eliminating equilibrium arches and material adhesion in bunkers; complex for screening and feeding coke breeze into the crusher; vibration delivery and ballasting installations; sleeper tamping vibration installation, as well as a rock mass transfer point in the quarry. A new mathematical model of the tamping process and a method for improving the tamping mechanism are proposed, which will increase the productivity of the sleeper tamping vibration installation. New vibration complexes make it possible to reduce the energy intensity of crushing by 15% and reduce the wear of the working surfaces of the crusher. It is shown that the construction of transfer points is carried out without additional preparation of the entire working bench. The operational capacity of the warehouse is selected within the range of 15–25 thousand m3 of rock mass. when used for loading iron ore cars with EKG-8I excavators with a daily productivity of up to 5000 m3, the warehouse stock is 3-5 days. The minimum specific energy intensity of release and loading of one ton of rock mass at the maximum value of productivity is ensured at frequencies of forced oscillations of the system ω = 15.5–17.5 Hz. The efficiency of the feeder-screen operation with spatial oscillations of the working body created by two multidirectional driving forces applied at two points at a distance from each other equal to 0.5 was determined. the width of the working body increases by 15%. Developers of technical documentation – SE “UkrNIPIIpromtekhnologii” (Zhovti Vody, Ukraine); Manufacturers: Krivoy Rog Ore Repair Plant (Krivoy Rog, Ukraine); Mechanical repair plant of the State Enterprise "Vostok GOK" (Zhovti Vody, Ukraine); Mechanical repair workshops of quarries, mines and processing plants, etc. It has been established that the research results represent a step in the theoretical generalization of the problem of developing the theory of interaction of grinding media in the grinding chambers of mills and increasing the efficiency of equipment for fine grinding of rocks, which is important for mining and metallurgical enterprises.
Goal Evaluation of technologies and technical means for the use of the phenomenon of the aqueous solution of natural bischophyte (RPB) in various branches of the national economy, in particular, the mining and mineral industry, ecology and medicine. Their use will improve the economic efficiency and environmental safety of the processes of blasting rock mass in quarries and storing waste from enrichment of ore raw materials in tailings storage facilities, freezing and freezing of ore mass during its transportation to enrichment plants. Research methods During the study, systematization, and generalization of technologies and technical means of using RPB, the analysis of research and publications, the results of industrial and experimental research at landfills using standard and new methods with the participation of authors and leading specialists in the specified fields were used. Scientific novelty The main scientific, practical and social results of the assessment of technologies and technical means for the use of the phenomenon of water RPB in various sectors of the national economy, in particular, in the mining industry, ecology and medicine, are given. The functional dependence between the freezing temperature of the mining mass (t с , °С) and the content of the aqueous solution of natural bischofite in it (С b , %) was established. Practical significance The technology to prevent winter slippage on quarry roads using RPB has been developed and implemented. Recommendations are given for combating the release of dust during the transportation of rock mass by rail transport, during mass explosions in quarries, on quarry highways and on tailings piles of GZK, with the use of RPB and bitumen emulsion, which allow to effectively fix dust surfaces from blowing dust. To reduce dust emission into the atmosphere during mass blasts in quarries, it is proposed to wet the surface of drilling dust with RPB with a density of 1250 - 1270 kg / m ³ and a consumption of 4.5 - 5.0 l / m ² . The results When using RPB instead of water during blasting operations in quarries, BP costs are reduced by 1.4-1.5 times and emissions of harmful gases during blasting are reduced by 20-30%. In underground mining operations, when water is replaced with RPB for moistening BP granules, the release of gases during a mass explosion in the mine is reduced by 1.3-1.4 times. To prevent freezing or freezing of rock mass to the inner surface of open wagons during transportation in the cold, preventive treatment of the inner surface of RPB railway wagons is carried out. In order to prevent ice on highways in quarries, they are also pre-treated with RPB. The technology of preventing winter slippage and dusting of quarry roads with RPB reagents with the use of watering machines was developed and implemented in the conditions of PJSC "Southern GZK" (Kryvbas, Ukraine). Recommendations for fighting dust on highways, landfills and tailings storage facilities of GZK, using RPB and bitumen emulsion, which allow to effectively fix dusty surfaces from blowing dust, using specially developed equipment, are given. In particular, the cost of processing ragweed RPB with an average overgrowth density of 5.0 kg/m ² at the current cost of the solution of UAH 960/ton does not exceed UAH 40 per 100 m ² (acre). One of the promising areas of further research is the use of large volumes of man-made underground cavities, formed during the leaching of bischofite, for the storage of useful liquid substances or for the disposal of waste at a depth of more than 1500 m.
A method for selecting the location of the mine is formulated, which reveals a certain deposit taking into account the level of design, and depends on the mining and geological conditions of the mineral occurrence, the general plan for the location of mining and processing plants and the chosen type of quarry transport. At the same time, competitive options for opening an iron ore deposit along the lying or hanging side of the ore body are considered, less often by the contact of the lying or hanging sides or by its middle. To evaluate the options for laying overburden and group trenches, it is necessary to use the following criteria: the distance of ore transportation from the quarry to the processing plant, waste rocks to dumps, processing waste to sludge storage facilities; the duration of the construction period to the starting capacity of the quarry; the net present value of ore extraction from the quarry and obtaining commercial iron-containing products from it during the existence of the mining and processing plant. It is proved that the choice of the opening method in the design of deposit development and the use of the optimal horizon opening scheme during operation directly affect the cost of ore extraction and the efficiency of open-pit mining operations. The distance of transportation of rock mass depends on the scheme of opening by internal trenches, so it is proposed to use the route development coefficient as an evaluation criterion, the values of which, as a rule, are in the range from 1.05 to 1.5, but they can reach 1.8.
The article presents the results of a study on the content of the concept of "financial literacy" and the current state of the issue concerning the development of financial literacy as a key competency in the professional training of future primary school teachers. To identify the content component of future teachers' readiness to instill financial literacy in primary school students, methods of pedagogical observation during undergraduate and graduate student teaching practices, and content analysis of existing methodological materials for primary education were used to detect economic (financial) themes within the technological educational domain. The analysis of theoretical and methodological literature revealed that the concept of "financial literacy" as a key competency for citizens has the same content for both primary education recipients and future teachers, explained by the very idea of "literacy" as a foundational level of knowledge and competencies. Observations showed a low level of financial competence and interest in exploring financial-economic aspects among future teachers during their practical teaching sessions. It is anticipated that in the professional training of primary education teachers, financial literacy as a personally significant competency should be combined with readiness to develop financial literacy in students. Conditions for such training include the use of personalized, competency-based, and coaching approaches. Based on the content of the concept of "financial literacy," key principles for developing financial literacy in students have been formulated: transparency of information, volunteerism and charity, autonomy of the child's budget; gradual accumulation of financial experience; combination of financial awareness and critical thinking; experience formation through play;
When mining steep deposits of Kryvyi Rih iron ore basin (Ukraine), a significant part of the reserves is lost in the “triangle” of the footwall. Complete extraction of reserves requires increased costs for mining ore. At present, there are options for mining reserves from the “triangle” of the footwall. However, all the proposed options lead to an increase in the cost of mining or increased ore losses and the reduced iron content in the mined ore mass. To reduce the cost of mining, an option is proposed with concentrated charges to break ore located between the footwall and the caved massif. In order to improve indicators of reserve extraction from the “triangle” of the footwall in the massif, it is advisable to place inclined concentrated charges at an angle of 58 – 78 degrees. To reduce broken ore dilution with waste rocks on the boundary, it is advisable to create an overcompacted layer of the broken ore mass by reducing the calculated value of the line of least resistance by a factor of 0.5 – 0.75. Application of this method of mining reserves from the block increases the content of iron in the mined ore mass by 1.2%, reduces discounted costs for driving workings and for drilling and blasting. Thus, due to application of the bulk level caving system with improved ore breaking by the use of concentrated charges located in the “triangle” of the footwall, the expected economic effect of mining of 718.2 kt makes 5.20 k USD.
The work explores technologies for transitioning from open pit to underground mining of minerals, focusing on stress-strain analysis of the rock mass during this process. It enhances methods for studying these stress-strain states, particularly in the context of combined technologies for iron ore extraction. The study proposes environmentally safe techniques for extracting magnetite quartzite, involving the use of internal dumps in open pits to dispose of mining waste. It develops and suggests efficient design schemes for managing stress-strain states during the transition and proposes using protective barrier pillars formed from artificial consolidating backfill for subsequent underground mining. Strains in these barrier pillars and the rock mass are calculated for various scenarios of waste filling. The study, exemplified by the Kryvyi Rih iron ore basin, demonstrates the environmental benefits of using abandoned open pits for waste disposal and underscores the economic advantage of these technologies. This innovative approach plays a crucial role in preserving the valuable Ukrainian agricultural chernozem. By implementing this method, there is a significant reduction in the amount of land required for agricultural use and minimizing environmental impact.
The Copenhagen criteria define the requirements for Ukraine’s membership of the European Union: democracy guaranteed by stable institutions, a functioning market economy and the ability to implement the union’s economic, political and monetary objectives. Despite progress made in important areas, Ukraine must take further steps on reforms related to abuse of power, lack of transparency and labour migration. Joining the European Union will pose a challenge for Ukraine to reform bad practices and implement European legislation into national law. The Association Agreement and Deep and Comprehensive Free Trade, which contain economic, judicial and financial principles, should be used as a model for a gradual approach to EU policies and legislation. Ukraine’s future success depends on the reforms implemented, the ability to eradicate corruption, keep people in the country, attract foreign investment and rebuild the country, while maintaining ongoing military support to defend the integrity of Ukrainian territory.
The article deals with the problem of organising the monitoring of saline soils using the example of farms in the Hungry Steppe and the Khorezm region of Uzbekistan. Due to the variability of salinity levels, continuous monitoring is required, which is difficult to organise using existing methods. The authors propose the use of a bioindication of soil salinity based on the condition of cotton plants. The aim of the study was to test the possibility of using cotton plants as bioindicators of soil salinity and to search for measurable indicators for the practical implementation of bioindication. As a result of the field studies, possible bioindicators such as leaf thickness, leaf area and the pattern of change in planting density were investigated. It was found that as soil salinity increases, cotton planting density changes according to Poisson's law. In order to minimise the time and work involved in organising the monitoring, it was proposed to use the thickness of the cotton leaf blade, measured with a digital micrometer, as a bioindicator parameter. For the practical implementation of salinity assessment by leaf thickness, the relationship "soil salinity - leaf thickness" was established in the form of a regression equation. The results obtained are similar to those of previous studies on a decrease in plant density, as well as a decrease in the area of the leaf plate and an increase in its thickness with increasing soil salinity. At the same time, the problem of the bioindication of soil salinity by the state of the cotton plant has not been considered so far.
We present a logic which deals with connexive exclusion. Exclusion (also called “co-implication”) is considered to be a propositional connective dual to the connective of implication. Similarly to implication, exclusion turns out to be non-connexive in both classical and intuitionistic logics, in the sense that it does not satisfy certain principles that express such connexivity. We formulate these principles for connexive exclusion, which are in some sense dual to the well-known Aristotle’s and Boethius’ theses for connexive implication. A logical system in a language containing exclusion and negation can be called a logic of connexive exclusion if and only if it obeys these principles, and, in addition, the connective of exclusion in it is asymmetric, thus being different from a simple mutual incompatibility of propositions. We will develop a certain approach to such a logic of connexive exclusion based on a semantic justification of the connective in question. Our paradigm logic of connexive implication will be the connexive logic CC{\textsf{C}}, and exactly like this logic the logic of connexive exclusion turns out to be contradictory though not trivial.
In situ-generated nanofibrillar polymer–polymer composites are excellent candidates for the production of polymer materials, with high mechanical and SME properties. Their special feature is the high degree of dispersion of the in situ-generated nanofibers and the ability to form entangled nanofiber structures with high aspect ratios through an end-to-end coalescence process, which makes it possible to effectively reinforce the polymer matrix and, in many cases, increase its ductility. The substantial interfacial area, created by the in situ formed fiber/matrix morphology, significantly strengthens the interfacial interactions, which are crucial for shape fixation and shape recovery. Using the polylactide/bio-polyimide (PLA/PA) system as an example, it is shown that in situ PA fibrillation improves the mechanical and shape-memory properties of PLA. The modulus of elasticity increases by a factor of 1.4, the elongation at break increases by a factor of 30, and the shape-strain/fixity ratio and shape recovery increase from 80.2 to 97.4% and from 15.5 to 94.0%, respectively. The morphology of the minor PA phase is crucial. The best result is achieved when a physically entangled nanofibrous network is formed.
The development of advanced shape memory polymers (SMPs) requires the creation of approaches that offer the possibility of forming different temporal shapes as well as changing the corresponding shape memory transition temperatures. A distinctive feature of ultrahigh plastic deformation methods is the possibility of producing polymer blends with a maximum content of interface to form a single broad thermal transition. This can be an attractive way to produce multi‐SMPs based on a simple processing technique. Two polymer pairs—glycol‐modified polyethylene terephthalate/polylactide (PETG/PLA), glycol‐modified polyethylene terephthalate/polybutylene terephthalate (PETG/PBT)—are used to form an immiscible symmetrical blend (50 wt%/50 wt%). Ultrahigh plastic deformation is achieved by high pressure torsion (HPT). HPT leads to intimate mixing of the chains of the respective polymer pairs. Thermomechanical programming successfully enables a triple shape memory effect with fine shape memory parameters.
This paper addresses the crucial task of devising comprehensive criteria and indicators for evaluating the effectiveness of pedagogical research conducted by academic and research staff in higher education institutions (HEIs). Four major assessment criteria are identified: publication and dissemination, utilization, impact on the academic community, and representation-scientific. Each criterion is further broken down into specific indicators, including involvement in project competitions, scientific publications in reputable journals and conference proceedings, indices and citations in various databases, altmetric indicators such as electronic repositories and social media engagement, expert involvement in academic and research activities, and attainment of academic titles and honors. The classification of these criteria provides a systematic framework for assessing the multifaceted aspects of pedagogical research effectiveness. Further research prospects involve assigning weight coe fficients to these criteria and developing a methodology that integrates digital technologies to streamline the assessment process.
The main scientific and practical results of the study and assessment of ventilation control in coal mines using the decomposition method based on data from the analysis of aerodynamic parameters of air distribution are presented. This will lead to increased safety and reduced accident rates in mining operations at coal mines. Methods of decomposition, statistical dynamics, set theory, fundamental laws of mining aerodynamics, and discrete mathematics are described. The studies were carried out based on the experimental data of the authors using various mathematical and statistical methods. A universal technique is proposed that can be used in mine workings for analysis, assessment of ventilation processes and associated aerodynamic factors, as well as optimization of the air distribution control system under various operating modes. A methodology and application software developed on its basis have been compiled. Automated geographic information systems such as GIS K-MINE® (Krivoy Rog, Ukraine) and VENTSIM are recommended. This system has been approved by regulatory authorities in Ukraine and is utilized by specialists from industry institutes, State Mining Supervision authorities, mines, and others. They are adapted for coal mines, ensuring increased safety and efficiency of work. This will ensure increased safety, labor protection, and reduced accident rates in coal mining operations.
Using histological cross-sections, chondrocranium anatomy was reconstructed for two developmental stages of Hermann´s tortoise (Testudo hermanni). The morphology differs from the chondrocrania of most other turtles by a process above the ectochoanal cartilage with Pelodiscus sinensis being the only other known species with such a structure. The anterior and posterior processes of the tectum synoticum are better developed than in most other turtles and an ascending process of the palatoquadrate is missing, which is otherwise only the case in pleurodiran turtles. The nasal region gets proportionally larger during development. We interpret the enlargement of the nasal capsules as an adaption to increase the surface area of the olfactory epithelium for better perception of volant odors. Elongation of the nasal capsules in trionychids, in contrast, is unlikely to be related to olfaction, while it is ambiguous in the case of Sternotherus odoratus. However, we have to conclude that research on chondrocranium anatomy is still at its beginning and more comprehensive detailed descriptions in relation to other parts of the anatomy are needed before providing broad-scale ecological and phylogenetic interpretations.
Мета. Прогнозування часового ряду як стохастичного щодо вартості залізорудної сировини за засадах методу Бокса-Дженкінса Методи. У процесі дослідження використано такі методи та прийоми пізнання: те-оретичне узагальнення і порівняння для вибору методу прогнозування, аналіз і синтез з метою системності дослідження, узагальнення та систематизаці задля отримання відповідних висновків, статистичні методи аналізу часових рядів з метою отримання прогнозу. Результати. У статті представлено етапи проведення статистичного аналізу часового ряду вартості залізорудної сировини. Встановлено, що сучасні економічні дослідження потребцуть більш ретельного аналізу залежності вартості залізорудної сировини від часу. Обгрунтовано, що необхідно розрізняти імовірнісну (стохастичну) модель і спостережуваний часовий ряд; для оптимального прогнозування вартості певного товару доцільно побудувати стохастичну модель. Побудовано математичні моделі стохастичних часових рядів, що відображають динаміку вартості залізнорудної сировину. Синтезовані стохастичні моделі враховують, що послідовні значення в часових рядах мають певну залежність, тому доцільно розглядати їх як породжені послідовністю незалежних імпульсів. На основі дослідження реальної залежності вартості товару від часу побудовано математичні моделі стохастичних часових рядів, що були застосовані для побудови прогнозу. Для безпосередньої реалізації прогнозу вартості товару побудовано відповідний стохастичний часовий ряд; сформовано економіко-математичну модель на основі динамічного ряду з метою прогнозування. Обгрунтовано, що якість прогнозу визначається не тільки похибкою прогнозу, а й кількістю параметрів, що входять до моделі функції прогнозування. Подальші дослідження спрямовані на проведення порівняльного аналізу методів прогнозування з метою виявлення відповідних помилок.
The aim of the work is the theoretical substantiation of the mechanism of water structuring using the effect of hydrophobic hydration on the example of the use of carbohydrate as a nanomodifier. To achieve the goal, the following tasks were set: to perform experimental and theoretical studies of the mechanism of influence of colloidal hydrophobic surfactants on the structure of water. The paper presents the results of theoretical studies of the influence of colloidal hydrophobic surfactants on the structure of water and the hydration mechanism of slag Portland cement. It is shown that the introduction of these surface-active substances into water in very low concentrations leads to the effect of hydrophobic hydration, that is, changes in the interaction between water molecules. Hydrophobic hydration contributes to the formation of the pore structure. It was established that hydrophobic hydration is characterized by the fact that part of the dissolved substance inhibits the translational movement of water molecules and is due to the fact that part of the solution space, corresponding to the own volume of the particles of the dissolved substance, is inaccessible to water molecules. Hydrophilic and hydrophobic hydration have different mechanisms. Large hydrophobic ions cause ordering of the water structure. Having a more ordered structure than pure water, solutions of these salts require less work for dissolution, as a result of which the solubility of the latter increases. The conducted experiments allow us to draw an unequivocal conclusion that polar groups are unable to prevent hydrophobic hydration. The introduction of hydrophobic surfactant molecules into water in the form of dimers is the structuring of water, that is, the formation of a continuous fractal network of water molecules. Keywords: fine-grained concrete, slag Portland cement, hydration, modification, surfactants, water activation
Institution pages aggregate content on ResearchGate related to an institution. The members listed on this page have self-identified as being affiliated with this institution. Publications listed on this page were identified by our algorithms as relating to this institution. This page was not created or approved by the institution. If you represent an institution and have questions about these pages or wish to report inaccurate content, you can contact us here.
191 members
Andrey Kupin
  • Faculty of IT
Vitaliy Tron
  • Computer Science, Automation and Control Systems Department
Andrii Striuk
  • Information technologies
A.A. Berezovsky
  • Faculty of Geology and Ecology
Information
Address
Kryvyi Rih, Ukraine