bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modeling of phase change hysteresis during partial phase change with the “shift”-method
Authors: Gamisch Sebastian , Gschwander Stefan 
Published: June 2024

Abstract
For phase change materials (PCM) a difference between melting and crystallization temperature can occur, the so-called supercooling. For numerical modelling of this hysteresis effect, phenomenological approaches based on the experimentally determined enthalpy-temperature relations for melting and crystallization can be applied. It is challenging to model the behavior for partial phase transitions. The study presents a new phenomenological method, called the “shift”-method. It is derived especially but not only for PCMs with a multistage phase change during crystallization, like it can occur for microencapsulated PCMs. The method is verified by experimental results and compared to an existing approach called “curve-scale”-method. Partial melting and crystallization processes of a PCM composite are experimentally characterized with differential scanning calorimetry (DSC). Additionally, both methods are integrated in a Dymola Modelica model of a battery cooling system with the PCM composite and validated against experimental results. The normalized mean square error is used to determine the deviation between the experiments and the two methods. It is less than 1.7 % for both methods.
Assessing the impact of copper wools on a phase change material-based TES tank prototype
Authors: Ribezzo A , Morciano M , Zsembinszki G , Risco Amigo S , Mani Kala S , Borri E , Bergamasco L , Fasano M , Chiavazzo E , Cabeza L F 
Published: June 2024

Abstract
Phase Change Materials (PCMs) stand out as a promising solution within the current array of Thermal Energy Storage (TES) technologies, thanks to their superior energy storage capacities (compared to sensible solutions) and technological readiness. Nonetheless, the limited thermal conductivity of these materials may lead to incomplete phase transitions during use, resulting in a decrease in their effective energy storage capabilities. The major solutions to mitigate this issue that are present in literature either require a significant modification in the heat exchanger design (e.g. by fins) or are costly and still lack robustness and reliability (e.g. by additivities). In this study, the use of copper wools is proposed as fillers within a PCM-based heat exchanger prototype, and the assessment of its impact on the heat transfer behaviour of the material is evaluated by performing charging and discharging processes. This type of inclusion was chosen as it is relatively cheap, it can be implemented within an already existing heat exchanger, and it does not suffer from segregation. Two different wools were tested in two configurations, thus resulting in five test cases (four containing the wools and one containing solely PCM). The promising results, especially the remarkable decrease in the time needed for the complete solidification of the PCM within the tank (up to 67%), open the opportunity to additional numerical analyses regarding different configurations and/or materials, thus possibly targeting further optimizations in terms of the specific energy density and the specific power density.
Fractal dimension of the morphology on differently oriented surfaces of coal preparations
Authors: Bezruchko Kostiantyn , Pymonenko Liudmyla , Baranovskyi Volodymyr 
Published: June 2024

Abstract
Choosing the surface of a lump section was justified to determine the degree of metamorphism by the index of gray shade intensity. The main method is optical spectroscopy using a video-optical complex MBI-11, NB 200 with subsequent digital computer processing and calculation of the fractal dimension (Scope photo software) of microphoto images of coal matter preparations by lump sections. The values for the index of gray shade intensity of photographic images of surfaces (section, bedding, cut) for lump sections based on samples of coals of various grades were analyzed. It has been established that the average values of the degree of metamorphism indices for different surfaces of the preparation differ, which is confirmed by low correlation coefficients: 0.585 (section-bedding), 0.666 (section-cut), 0.462 (cut-bedding). It has been found that the fractal dimension, which characterizes the complexity of the morphology of the surfaces under study, reflects an increase in the amount and orderliness of hydrocarbons associated with a change in the degree of metamorphism. It was proven that its most natural decrease related to an increase in the degree of metamorphism, is observed on surfaces perpendicular to the bedding (section).
Protection of drilling equipment against vibrations during drilling
Authors: Pashchenko Oleksandr , Khomenko Volodymyr , Ishkov Valerii , Koroviaka Yevhenii , Kirin Roman , Shypunov Serhii 
Published: June 2024

Abstract
The article is devoted to the study of important problem of influence of vibrations on drilling and drilling equipment. Vibration can adversely affect the condition of equipment, reducing its durability and productivity, as well as creating the risk of breakdowns and accidents for workers. Various vibration protection methods and technologies are considered, such as use of shock absorbers, vibration dampers, active control and intelligent control systems. The main attention is paid to methods of measurement and analysis of vibration spectrum, which allow to understand the nature of vibrations and to determine their main parameters. This helps to establish criteria for evaluating the level of vibration for drilling equipment and to make necessary protection decisions. Application of modern technologies and innovative approaches, such as the use of intelligent control and management systems, allows to achieve better results and reduce the impact of vibrations on drilling and drilling equipment. In general, the implementation of vibration protection systems in drilling is an important step in improving the quality and safety of work, saving equipment and reducing maintenance costs. The use of modern technologies and innovative approaches helps to achieve optimal drilling productivity and efficiency, which is a key success factor in well drilling.
From the experience of the technical examination of hydro-technical tunnels
Authors: Krukovskyi Oleksandr , Skipochka Serhii , Serhiienko Viktor 
Published: June 2024

Abstract
A comprehensive methodology is proposed and the results of the technical examination of hydraulic tunnels are given. The technique takes into account the influence of water flow, the formation of cavities behind the shell, fixes defects, and reveals the prerequisites for their formation. It consists of visual inspection and non-destructive testing (ultrasonic, electromagnetic, vibro-acoustic). A unified presentation of the examination results is proposed. The optimal basis and operating frequency of the ultrasonic method are substantiated. The gradations of the processes of the formation of cracks in concrete are determined by the frequency of electromagnetic radiation. Examples of tunnel examination are given. Characteristic areas of the objects are identified. For main canals, this is a shell near the entrance and exit portals. Cavities behind the shell can be traced along the entire length of the tunnels. The main defect of the shells of pressure tunnels of power plants is cracks in the reinforced concrete lining. For structures of seasonal drainage, filtration in the bottom is characteristic. The examination results are used to develop projects for repair works. Some methodical regulations can be used for inspecting any underground structures.
Coal mining and water resources: impacts, challenges, and strategies for sustainable environmental management
Authors: Hasii Olena , Gasii Grygorii 
Published: June 2024

Abstract
The intricate relationship between coal mining and water resources is discussed, as well as coal mining affects the quality and availability of water is highlighted. Coal deposits play a major role in energy production, and at the same time, coal mining causes adverse environmental effects. For this reason, the article is devoted to the study consequences of coal mining on water contamination and soil conditions. The investigation results show that coal mining causes dangerous and harmful particles to reach the surface of the water, degrades the soil, and causes chemical exposure. Hydrology and water quality throughout the mining lifecycle are influenced by such consequences, which can be observed across mining regions and under different extraction methods. In this regard, there exists a need for effective strategies and implementing best practices for mining operations, adopting preventive measures for acid mine drainage, and advanced water management techniques. Also, the experience of effective environmental management is discussed. Mining reclamation plans, adherence to specific standards, and the role of rocks selection in reclamation success are discussed. Considering the above balancing energy needs with sustainable environmental practices is crucial to ensuring the coexistence of mining and global water resources.
Modeling of separated flow over tailings storage facility
Authors: Rusakova Tetiana , Rusakova Kateryna 
Published: June 2024

Abstract
Tailings storage facilities are an integral part of modern mining and beneficiation production and the most serious threat to environmental safety. Separated flow over surfaces, even in the case of constancy of their shape, is a very complex phenomenon. The occurrence of a separation with the rise of vortexes into the flow leads to a strong unsteadiness of the flow. To consider such flows, the most common in applied aerodynamics are vortex methods, which are based on replacing the surface and the wake formed behind it with some distribution of vorticity. Numerical calculation technique based on the method of discrete vortexes is used to model the separated non-stationary flow around the tailings storage facilities. This method makes possible to describe the structure of the vortex flow over the tailings storage facilities and behind it, to study the change of vortexes over time, to see the presence and absence of stagnant zones on the windward side of the tailings storage facilities. Prediction of the aerodynamic structure of the flow is a necessary component of the process of justifying decision-making regarding the use of means and methods for dust reduction.
Analysis of changes in global warming potential during enrichment and production of battery-grade graphite using electrothermal fluidized bed technology
Authors: Hubynskyi Semen , Sybir Artem , Fedorov Serhii , Usenko Andrii , Hubynskyi Mykhailo , Vvedenska Tetyana 
Published: June 2024

Abstract
The greenhouse gas emissions during the production of anode class graphite for the conditions of Ukraine have been calculated. Conventional technologies and technologies using electrothermal fluidized bed (EFB) for natural and synthetic graphite have been studied. Calculations are carried out with respect to the whole technological chain, starting from extraction and processing of raw materials and ending with finishing processing (coating). As a result, it is shown that the technology of using EFB for purification of natural graphite and graphitization of synthetic graphite is competitive in terms of global warming potential (GWP). In the production of natural graphite using thermal purification with EFB instead of chemical purification, emissions of greenhouse gases practically remain at the same level. At the same time, the use of acids is eliminated, and the environmental impact associated with them is reduced. Production of synthetic graphite of anodic quality in EFB furnaces allows to reduce greenhouse gases (GHG) emissions by 40-50% in comparison with traditional graphitization technologies in Acheson and Kastner furnaces. The effect is achieved by reducing energy and raw material consumption.
Monitoring and estimation of mining and geometric indicators of the deposit
Authors: Peremetchyk Andrii , Pysmennyi Serhii , Chukharev Serhii , Korniyenko Valerii , Fedorenko Serhii 
Published: June 2024

Abstract
The article presents the results of mining and geometric modeling of indicators of mineral deposits. In order to estimate and monitor them, a wide range of geoinformation systems-based methods and techniques of geometrization is applied. The sequence and stages of mining and geometric estimation of deposits are described considering specific mining and geological conditions. The built models are used at Ukraine’s mining enterprises that develop solid minerals. Much attention is paid to processing initial mining and geological data, providing the basis for mining and geometric modeling. Geostatistical methods give high results when processing and assessing reliability of the input modeling data and processing and presenting modeling results. Different types of deposits require different approaches to geometrization. Deposits with high variability of indicators require accounting, data grouping and zoning. For this purpose, a heuristic algorithm is developed, which is an efficient independent method of modeling and enables considering the high level of heterogeneity of the spatial distribution of mining and geological indicators of the deposit. The results of the modeling can be used for deposit estimation and monitoring, reserves calculation, and mining operations planning.
Theoretical foundations of developing a software-hardware complex for monitoring and managing the geophysical state of regions in Ukraine
Authors: Romanenko Andrii 
Published: June 2024

Abstract
This article explores the essence and important aspects of the software and hardware complex for monitoring and managing the geophysical condition of a region. Various structural schemes of the complex are analyzed in the article, including linear sequential, modular, hierarchical, matrix, and integrated. The choice of an optimal scheme determines the efficiency of the monitoring system. Next, the importance of the database structure for effective collection and analysis of geophysical data is discussed. Based on the collected information, a hierarchical structure for monitoring and managing large territories, such as Ukraine, is proposed, providing centralized management, regional subsystems, and local monitoring. Conclusions and recommendations for creating a state program, including the development of a strategic plan, definition of technical requirements, fundraising, and collaboration with partners, are provided. Through these steps, it is possible to create a comprehensive and well-organized system for monitoring and managing the geophysical condition of the region, ensuring the safety, stability, and prosperity of citizens. The presented aspects take into account important requirements and needs for the implementation of similar projects for better management of natural risks and events.
Optimization of mine water discharge with the river hydrograph. Case study Samara River in Western Donbas
Authors: Rudakov Dmytro , Sun Yajun , Inkin Oleksandr 
Published: June 2024

Abstract
The paper deals with modeling salt transport in surface watercourses affected by mine water discharge taking into account the river hydrograph, hydrogeological, and climatic data. The developed model enables optimizing the discharge parameters; thus, minimizing the mineralization of river water throughout the year. As the case study, we considered the section of the Samara River in the Western Donbas where mine water is discharged from three storage ponds located in the ravines of Kosminna, Taranova, and Svidovok. Taking into account the pond capacities, it is proposed to discharge at least 60% of mine water from all ponds in December-April, with more than 88% of the most mineralized waters from the pond in the Svidovok ravine. The increase of the river water mineralization at the exit from the coal mining area does not exceed 0.22 g/dm3 on average per year, with a maximum of 0.36 g/dm3 during the low water season. The model novelty is coupling natural and man-made factors forming the water and salt balance in the surface watercourse throughout the year with the optimization methods. The proposed technique can be used to optimize the mode of mine water discharge.
Methodology for determining the scope of reclamation works when forming recreational zone in the quarry residual space
Authors: Lozhnikov Oleksii , Adamova Viktoriia 
Published: June 2024

Abstract
The article is devoted to the development of methodological recommendations aimed at increasing the recreation territory during reclamation, taking into account the flooding of the quarry residual space. Calculations of the reclamation works volume during the forming of a recreation area on the quarry slope were made. The influence of the embankment section width of the soil in the flooded quarry space on the embankment geometric shape was established. Calculating method of the reclamation works volumes are proposed, taking into account the indicators of the slope inclination angle and the height of the embankment being formed. A scheme for the safe recreation area location within the quarry residual space has been developed, which allows determining the necessary parameters of the mining elements that affect on the volume of embankments construction. A method of determining the volume of works for the formation of a recreation area in the quarry is proposed, taking into account the embankment width and height, the resulting slope angle, the safe angle of mining rocks inclination at the dumping into flooded quarry. It has been established that the volume of reclamation depends on the embankment parameters when the quarry watered area is changed.
Prospects for systematization of lignite deposits to provide Ukraine with raw materials in the postwar period
Authors: Shustov Oleksandr , Pavlychenko Artem , Bielov Oleksandr , Adamchuk Andrii , Eluzakh Mukhtar 
Published: June 2024

Abstract
The contribution of the mining industry to the economy of Ukraine and the current state of coal mining are analyzed on the basis of statistical data on balance sheet reserves of black coal by grade. The indicators of balance reserves and quality characteristics of lignite and associated minerals (coal clays) of the Dnipro Basin are specified. Prospects for the resumption of production are presented and a preliminary economic assessment of the attractiveness of the lignite application is made. The lignite reserves are partially recalculated taking into account the extraction of coal clays to increase the capacity of the country’s fuel and energy sector. The prospects for compiling a catalog of lignite raw materials are determined, taking into account the mining and geological conditions of occurrence and the quality characteristics of the mineral. The scientific novelty of the research is to catalog the deposits of the Dnipro Basin and rank them with a preliminary technical and economic assessment of lignite production. The practical significance is to create a ready catalog of lignite raw materials that will allow a potential investor to implement his or her economically viable project for the development of the deposit.
Changes in the physical and mechanical properties and structure of rocks depending on the depth of mining operations in iron ore quarries
Authors: Antonik Valeriy , Chepurnyi Volodymyr , Baranov Ihor 
Published: June 2024

Abstract
The trend of the activity of open-quarry mining enterprises of iron ore raw materials is an increase in depth quarries. It is investigated in the work, changes in physical and mechanical properties and rock structure depending on the depth of mining operations in quarries. Natural geophysical and laboratory methods of research were applied. It was established that the angle of internal friction, Poisson’s ratio and rock density practically do not depend on depth of mining operations. But with an increase in the depth of iron ore quarries, there is an increase in the compressive and tensile strength of rocks. Indicator of specific adhesion has significant dynamics of fluctuations depending on the mineral composition of rocks and can either increase or decrease in deep horizons, which must be taken into account in each specific calculation. For example, by determining marginal angles of slopes of sides and ledges. According to the data of geophysical studies, it is established a characteristic increase in the intensity of creep shear processes and surface deformations rocks when the quarry depth increases. The results of research are recommended to be taken into account when organizing the mining and technological process in deep iron ore quarries.
Analytical researches of a vibrating mill with vibroimpact excitation of a crushing chamber
Authors: Shevchenko Heorhii , Shevchenko Volodymyr 
Published: June 2024

Abstract
The scheme of a vibrating mill with a drive from inertial debalanced vibrators and with vibroimpact excitation of a grinding chamber with a technological medium has been developed. Analytical researches of the vibration mill were performed according to the universal mathematical model of vibroimpact systems. It was established that vibrating mills with vibroimpact excitation of the grinding chamber, in comparison with typical vibrating mills, which are made according to a single-mass dynamic scheme, provide: an increase in the vibration parameters of the grinding chamber with an increase in the mass of the technological medium, which to some extent levels out the decrease in the vibration parameters of the technological medium and, accordingly, increases mill productivity; the possibility of realizing significant accelerations of the grinding chamber with the technological medium at relatively insignificant accelerations of the mill frame with vibration exciters, which increases the reliability and durability of the mill’s operation; transfer of insignificant dynamic loads to the base, which do not exceed the static reactions from the force of gravity, which makes it possible to install the mill on a fixed base without its fixation and the need to arrange a massive foundation under its supporting surface.
Stefan flow-inclusive mass transfer in a narrow cylindrical channel with a two-layer medium
Authors: Yelisieiev Volodymyr , Lutsenko Vasyl , Ruzova Tetiana , Haddadi Bahram , Harasek Michael 
Published: June 2024

Abstract
The exploration and extraction of oil, coal, and gas reserves are closely tied to mass transfer phenomena within porous and fractured rock formations. Frequently, these processes involve the adsorption or desorption, dissolution, or evaporation of certain components on the surface of the pore channels. In these cases, Stefan hydrodynamic flows arise, and although they may be individually small, they can have a noticeable impact on mass transfer and flow structure considering particular length of the channel. The authors explore the issue of inert component diffusion from the surface of a capillary into a suspension flow. The analysis involves a two-layer flow, including a central two-phase (liquid and particles) component and a near-wall flow of the fluid carrier. A certain component from the channel’s surface permeates deep into the flow without interacting with the solid phase. In this research the authors solve a diffusion problem with boundary conditions that consider the presence of Stefan hydrodynamic flows. The calculations reveal that, depending on the magnitude of the Stefan flows and the length of the affected area, the porosity, and consequently, the viscosity of the two-phase flow zone can undergo significant variations.