bluuebunny/crossref_metadata_2025 huggingface dataset:
Enhanced latent thermal energy battery with additive manufacturing
Authors: Morciano Matteo , Alberghini Matteo , Fasano Matteo , Almiento Mariella , Calignano Flaviana , Manfredi Diego , Asinari Pietro , Chiavazzo Eliodoro
Published: June 2024

The low thermal conductivity of Phase Change Materials (PCMs), such as paraffin waxes, hinders efficient latent heat storage, especially for rapid charging and discharging cycles. To address this issue, this study explores experimentally and numerically the use of metal additive manufacturing to create a latent heat storage system operating at medium temperatures (around 90°C). A 3D Cartesian metal lattice is manufactured through laser powder bed fusion to optimize heat conduction within the PCM. Experimental tests show impressive specific power densities (approximately 714 ± 17 W kg−1 during charging and 1310 ± 48 W kg−1 during discharging). Moreover, the device exhibits stability over multiple cycles. Finally, the validated finite-element model has the potential to provides a basis for general design guidelines to boost the system’s performance further. Potential applications of this technology are highlighted in the automotive industry, where such systems could efficiently manage thermal energy, for instance, by capturing excess heat from an engine’s cooling radiator to expedite the warm-up process during a cold start, which is a critical phase for reducing pollutant emissions.
Numerical study on hybrid battery thermal management system integrating water, phase change material, and fins, under New European Driving Cycle
Authors: Thakur Satyam Singh , Kumar Lalit
Published: June 2024

This study introduced a hybrid thermal management system for a 4×4 cylindrical lithium-ion battery module, simulating New European Driving Cycle (NEDC) conditions. The system integrated water, phase change material (PCM), and fins for enhanced heat dissipation. The batteries, attached to an aluminium shell, incorporated PCM and a central coolant path. Fins were introduced between the coolant channel and Al shell to enhance heat transfer between batteries, PCM, and water. Comparative analysis against passive (PCM only) and active (liquid) cooling systems revealed the hybrid system’s superior performance. With a water flow rate of 2×10−8 m3/s, the system consistently kept temperatures below 50°C during charge-discharge cycles. Compared to active cooling, it achieved a significant temperature reduction of 18.47% and 5.01% after the charge and discharge processes. An intermittent cooling strategy further demonstrated its effectiveness in preventing thermal runaway (> 60°C) compared to the active cooling system. The proposed hybrid system demonstrated efficient thermal performance with low pumping power, suggesting its potential for multiple charge/discharge cycles.
CFD simulation of solid/liquid phase change in commercial PCMs using the slPCMlib library
Authors: Buruzs Adam , Giordano Fabrizia , Schieder Manuel , Reichl Christoph , Goderis Maité , Beyne Wim , De Paepe Michel , Barz Tilman
Published: June 2024

Modelling the solidification and melting behavior of phase change materials (PCMs) can present several challenges, including non-isothermal phase change, multi-step transitions, complex enthalpy-temperature relations and convective heat transfer. To tackle these challenges, this study proposes a novel numerical method based on real experimental data for modelling complex phase change behavior of commercial PCMs in Ansys Fluent CFD software. The phase transition of PCMs is simulated with the apparent heat capacity (AHC) method, which is implemented as a User-Defined Function (UDF). Heat convection is simulated with the Boussinesq approximation. The method is validated by comparing to the Ansys Fluent built-in Solidification and Melting (S&M) model for the case of piecewise constant heat capacity. The results show that AHC method provides excellent agreement with S&M model for a piecewise constant heat capacity model. In addition, the AHC method solves convergence problems even for narrow phase change temperature ranges when a smooth heat capacity function is assumed. Finally, the AHC model is also tested on a set of commercial PCMs exhibiting complex phase change behavior. Temperature dependent specific heat capacities are determined from heat capacity data provided by PCM manufacturing companies and are imported as cubic Hermite spline functions from the solid-liquid phase change material library slPCMlib available at https://slpcmlib.ait.ac.at/. From the presented case study and tested PCMs it can be concluded that the AHC method is numerically robust when used with sufficiently smooth heat capacity functions, and it can be recommended for the analysis of heat transfer with PCMs showing a complex phase change behavior.
Numerical modelling of thermal hysteresis in melting and solidification of phase change materials
Authors: Goderis Maité , Buruzs Adam , Giordano Fabrizia , Barz Tilman , Beyne Wim , De Paepe Michel
Published: June 2024

This research focuses on exploring the impact of thermal hysteresis effects on the performance of Phase Change Materials (PCMs) used in thermal storage or buffering applications. Computational Fluid Dynamics modeling in ANSYS Fluent is employed to investigate thermal hysteresis phenomena during solid-liquid phase change. The traditional enthalpy-porosity method is extended by introducing an alternative relationship between the liquid fraction and PCM temperature, implemented in Fluent through User Defined Functions. The study demonstrates the developed model by simulating a rectangular PCM enclosure with a heated wall featuring a time-dependent temperature boundary condition. Considering convective heat transfer, a comparison is made between the newly developed hysteresis model and the default solidification-melting model of ANSYS Fluent. The new model facilitates numerical analysis of thermal hysteresis during partial and complete melting and solidification processes, enabling the study of hysteresis effects on the part-load operation of PCM systems.
Characterization of hydration levels of salt hydrate using X-ray computed tomography
Authors: Fenk Benjamin , Stamatiou Anastasia , Guarda Dario , Martinez-Garcia Jorge , Schütz Philipp , Gwerder Damian , O’Neill Poppy , Ravotti Rebecca , Mancin Simone , Fischer Ludger , Worlitschek Jörg
Published: June 2024

Salt hydrates are promising phase change materials (PCMs) for energy storage due to their high enthalpy of fusion and cost-effectiveness. However, they face challenges like segregation. X-ray computed tomography (XCT) is suggested for non-destructive analysis to assess the formation of segregation. But first, the feasibility of using XCT to distinguish between different hydration levels of salt hydrates needs to be investigated. This study compares XCT gray values of anhydrous and salt hydrate samples, particularly sodium acetate (SA) hydrates, to understand the influence of hydration level on XCT images, aiming to assess XCT’s suitability for salt hydrate investigation.
Modeling of phase change hysteresis during partial phase change with the “shift”-method
Authors: Gamisch Sebastian , Gschwander Stefan
Published: June 2024

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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.
Assessing the stability of underground workings in urban infrastructure
Authors: Shapoval Volodymyr , Shashenko Oleksandr , Morklianyk Bohdan , Skobenko Oleksandr , Barsukova Sofiia
Published: June 2024

This article presents the analytical formulas necessary for making optimal design and technological decisions when laying shallow underground mine workings. They make it possible to determine the following critical parameters of mine workings: the critical height of the lift of the arch of natural equilibrium is the surface above which the rock is in an undestroyed state; stability coefficient of the arch of natural equilibrium (it shows in what state the rock above the excavation is); critical rock pressure is the pressure that, if exceeded, causes the rock to collapse above the working without support; critical depth of the mine working; critical pressure in the pore fluid is the pressure above which the rock collapse above the working without support; design maximum rock pressure with a given safety factor; design maximum depth of the working with a given safety factor; rock pressure on the support.
Physical and chemical characteristics of the composite material Zeolite-Alginate-Fe(OH)3
Authors: Frolova Liliia , Pasenko Oleksandr , Tiapkin Oleh , Kashkalda Natalia
Published: June 2024

The article examines the physical and chemical properties of Zeolite-Alginate-Fe(OH)3 granules, which were synthesized by applying iron hydroxide to alginate-zeolite granules. In the work, the process of synthesis and granulation of Alginate-Zeolite-Fe(OH)3 adsorbent was investigated. The process of application of the active magnetic phase of the adsorbent was studied. The dependence of the static strength of the granules on the content of the solid phase (43 - 51 kPa) was established. Adsorption of lead cations from aqueous solutions was investigated. For the Zeolite-Alginate-Fe(OH)3 adsorbent, the specific adsorption capacity was 13.195 mg/g. It was established that the addition of trilon B in the synthesis process leads to an increase in adsorption capacity by 40%.
Rationalizing the selection of cleaning solution type through quantum chemical calculations
Authors: Nechytailo Mykola , Nahorna Olena , Nesterova Olena
Published: June 2024

The surface water sources for water supply are contaminated with substances that cause water discoloration. These substances include soluble humic and fulvic acids, which are retained on the surface during ultrafiltration membrane treatment, forming a fouling layer that deteriorates membrane performance and reduces membrane productivity. These substances also form a mixed fouling layer with water-soluble metals and coagulants. This work proposes a theoretical justification for cleaning solutions capable of restoring the properties of ultrafiltration membranes. Quantum-chemical calculations and modeling were chosen as the method for prediction and justification. EDTA-Na, SDS, and sodium tripolyphosphate can wash away the fouling layer, but it is impossible to justify the use of mixtures of these substances theoretically. As the quantum-chemical analysis showed, each of these substances has a tendency to wash away the fouling layer. However, it is impossible to justify the use of mixtures of these substances from a theoretical point of view. The pollutants in surface waters have a complex organomineral composition. Considering this, optimal components and concentration ratios of reagents for ultrafiltration membrane cleaning cannot be determined using quantum-chemical prediction methods, so experimental studies of cleaning processes are necessary.
Regularities of subsidence progress in terms of the repeated earth’s surface undermining in the context of Lviv-Volyn coal basin
Authors: Bubnova Olena
Published: June 2024

Study of deformation manifestation within the undermined rock formation and at the earth’s surface is among the key problems during underground mineral mining. The paper has analyzed the available methods identifying the earth’s surface subsidence in the process of its undermining through underground excavation. The analysis has shown branching as well as different approaches and numerous factors. The researchers believe they influence the results. Hence, the purpose is to substantiate regularities of the earth’s surface subsidence while its undermining by means of longwalls varying in their length. The study was carried out using materials of the actual observations on the subsidence in 31 profile lines under the conditions of SE Lvivvuhillia mines. To identify the functional regularities, the factors were assumed which researchers consider as the most influential ones. The performed correlation and regression analysis demonstrated clear relation only for longwall length and moderate relation between subsidence deviation and longwall length-mining depth ratio. A graphical-analytical technique was applied to define distribution of subsidence deviation points depending upon a longwall length-mining depth ratio; moreover, a coefficient was determined to be used while calculating design subsidence values if the longwall length-mining depth ratio is 0.1-0.7.
Mining and geological conditions for the occurrence of sudden gas-dynamic phenomena in the coal mines of the Donets Basin
Authors: Bezruchko Kostiantyn , Vergelska Nataliia , Dedelyanova Kremena , Pymonenko Liudmyla , Vergelska Viktoriia , Sira Nataliia
Published: June 2024

Over a long period in the development of coal deposits in the Donets Basin, a technogenic multi-level system of workings has been created. The increase in the number and power of gas-dynamic phenomena in coal mines occurred in connection with the increase in the working depth and the expansion of coal workings towards the technical limit of the mine field. The characteristics of the hydrocarbon component in the gas mixture of coal fields are constantly changing, and their content increases significantly in tectonically disturbed zones of coal rock massifs. Qualitative and quantitative parameters of gas mixture indicators are controlled by the tectonic structure of coal rock massifs. While studying the mining and geological conditions in the coal mines of the Donets basin, it has been established that the main factors provoking sudden gas-dynamic phenomena include tectonic discontinuous faults (as well as small-amplitude faults or their zones), abnormally high bed pressures, stress state and gas content of the massif. The results of the conducted research will become the foundation for predicting mining and geological conditions favorable for gas-dynamic phenomena in coal workings, which will make it possible to develop a concept for preventing potential dynamic phenomena in mines.
Simulation modelling of residual resource for hoisting mechanisms in the mining industry
Authors: Kruzhnova Svitlana , Fursina Anna , Ilin Sergey , Adorska Larysa , Ilina Inna
Published: June 2024

The rationale for prolonging the operational life of the crane is rooted in the economic viability of conserving metal and energy, leading to ecological benefits. Cranes, being structures with a high metal content, contribute to pollution reduction by eliminating the necessity for additional manufacturing processes in mining, metallurgical, machinery plants, and energy supply facilities. To assess the remaining service life, statistical simulation modelling is employed. The objective is to showcase the feasibility of determining the residual resource within the time interval using the Monte Carlo method in simulation modelling. In this analysis, multiple random parameter values are generated, and calculations are performed to form a statistical distribution of the results. The reliability theory utilizes the Weibull distribution. Once the distribution parameters are established, the residual resource of the metal structure operating in the interval can be ascertained. A crane with a service life of more than twenty years is considered, and the quantity is modelled randomly within the range from zero to one. From twenty experiments, the results indicate an average resource with a confidence interval of few years.
Diffraction, spectroscopic and microscopic studies of the sand from the amber deposit
Authors: Kuzmanenko Halyna , Okholina Tetiana , Sofińska-Chmel Weronika , Maciołek Urszula , Drewniak Marek , Goliszek Marta , Wąż Barbara , Fursovych Ivan
Published: June 2024

QUARTZ sand plays a crucial role in the production of float glass, as it is the main source of silicon dioxide, which is necessary for the production of glass. The research was conducted on two samples of QUARTZ sand from the Oleksiivka amber deposit. The aim of this study was to investigate the morphology and chemical composition of QUARTZ sand samples. The identification methods such as infrared spectroscopy, X-ray diffraction, and electron microscopy with the Energy Dispersive X-ray Spectrometer detector were presented. Applied methods allowed to identify crystalline phases and non-crystalline components of the tested samples.
Prospects for using screens with double vibration-impact excitation for size separation and dewatering of wet mineral raw materials that are difficult to classify
Authors: Lapshyn Yevhen , Shevchenko Oleksandr
Published: June 2024

One of the most labor-intensive and energy-consuming processes is the process of particle size separation and removal of moisture from products of wide particle size classes with a high content of small classes less than 0.2 mm in size. Such raw materials are dehydrated by traditional methods to 18-22% and are practically not classified. A review of methods for intensifying these processes showed the promise of vibration impact, which can be applied to both the sieving surface and the processed raw materials. The designs of screens with double vibration-impact excitation for particle size separation and dewatering of wet mineral raw materials are considered. The influence of operating parameters and screening time on the technological performance of these processes was experimentally studied. It was established that the use of a disintegrator simultaneously with an activator and disintegrating elements made it possible, without the use of additional power, to reduce the moisture content of the over-grid product to 4-5% while extracting the -0.1+0 mm class into the under-grid product to 83-85%. The results obtained confirmed the prospects of using screens with double vibration-impact excitation for size separation and dehydration of wet mineral raw materials that are difficult to classify.
Fundamental principles and results of deep well lining
Authors: Stavychnyi Yevhen , Koroviaka Yevhenii , Ihnatov Andrii , Matyash Oleksandr , Rastsvietaiev Valerii
Published: June 2024

The review of the theory and practice of the special technological fluids application is analyzed. On the example of a specific borehole, with an actual vertical depth of 3287 m, intended for opening horizons B-17v, B-17n and project B-21, measures to clarify the filtration and capacity properties of reservoir rocks, increase production volumes are considered of hydrocarbons and accelerating the rate of selection of mining reserves. Testing in the interval 3364 - 3337.6 m of the B-21 horizon by using a set of test tools KVI-95, objectively proved that the specified object is characterized as penetrating, gas-saturated, the activity of which is reduced by contamination of the near-outbreak zone of the seam. As a method of determining clogging, a cut of the working end of the core with a length of 1 mm was applied. According to the results of the interpretation of the materials of the geophysical research of the specified borehole, it was established that the seam fluid comes from the interval 3339 - 3344 m. The paper determined that a promising way to solve the issue of high-quality cementing is the application of composite tamponage systems in combination with advanced preparation methods of borehole shaft.
The scientific landmarks for the development and evaluation of the effectiveness of vibration and noise absorbing materials
Authors: Belikov Anatoly , Tairova Tamara , Bykovskyi Anatoly
Published: June 2024

The mastic compositions with vibration and noise absorbing properties have been developed to reduce the level of noise and vibration in the low- and high-frequency range of the spectrum. Evaluation of the effectiveness of the developed vibration and noise absorbing mastic compositions “Vibroshtil” and “Vibroshtilmaxi” was carried out on an experimental installation by the method of free damping of plate vibrations with the determination of the decrement of vibrations. Mastic compositions are characterized by a high value of the sound absorption coefficient and the coefficient of mechanical losses in the range of operating speeds. The introduction of developed vibration and noise absorbing materials with an extended spectrum of action at the workplaces of workers will reduce the level of vibration and noise in the low- and high-frequency range of the spectrum by 7–15 dB and create safe working conditions. The main characteristic of the vibration and noise absorbing composite is the sound absorption coefficient, the value of which is in the range from 0 to 1. The main advantage of these compositions over the existing ones is the ease of manufacture, the ability to apply them to any surface by spraying or puttying.
Analytical modelling and design of linear controlled dynamic systems
Authors: Kravets Viktor , Kolosov Dmytro , Kravets Volodymyr , Dolgov Olexandr , Onyshchenko Serhii
Published: June 2024

A generalized canonical mathematical model of multidimensional controlled mining transportation complexes and other technical systems in form by A.M. Letov is considered. A principle of symmetry and an algebraic concept are in the basis of the developed analytical methods of design. A principle of symmetry is realized on a set of indexes of roots of a characteristic equation of the system and on a set of indexes of phase coordinates of the mathematical model. The problem of quality of dynamic processes in time is reduced to an algebraic problem of distribution of roots of a corresponding characteristic equation in a complex plane. An analogy in a procedure of transformation of a characteristic determinant into a polynomial and a structure of elementary symmetrical polynomials of roots is established. A new formulation of an analytical representation of change of phase coordinates in time in a form of ordered determinants with respect to indexes of roots and indexes of phase coordinates is obtained based on residue theorem. An illustration of the developed analytical method of design is performed on a special case of a well-known controlled technical system of the fourth order.
Prediction of fuel consumption and carbon dioxide emission when replacing gaseous fuels with renewable hydrogen or their mixture
Authors: Gupalo Olena , Yeromin Oleksandr , Kabakova Liudmyla , Kolienko Anatoliy , Kirsanov Mykhailo , Kulikov Andrii
Published: June 2024

The paper is devoted to predicting changes in fuel consumption and carbon dioxide emissions when industrial equipment is converted to heating with renewable hydrogen or a mixture of it with other gaseous fuels, such as natural gas. The authors developed a simplified methodology that is appropriate for assessing changes in the energy consumption of equipment and the environmental impact of fuel replacement at the stage preceding the equipment reconstruction. The peculiarity of the methodology is that it allows the calculation of fuel consumption and carbon dioxide emissions when fuel replacement is accompanied by the implementation of measures aimed at improving the energy efficiency of equipment. The methodology can be used for heating and thermal furnaces in metallurgy and mechanical engineering, units for heat treatment of raw materials in the mining and processing industries, heating devices in the food industry, and water and steam boilers. In the example of replacing natural gas with its mixture with renewable hydrogen of different compositions, it is shown that the calculation error using the proposed methodology in comparison with the results obtained by mathematical modeling of fuel combustion, gas flow and heat transfer in this furnace does not exceed 1.5%.
Numerical modeling of the thermal characteristics of a fan spray cooling tower
Authors: Zhevzhyk Oleksandr , Potapchuk Iryna , Pertsevyi Vitalii , Bosyi Dmytro , Biriukov Dmytro , Shevchenko Serhii
Published: June 2024

The work constructs a mathematical model of the heat and mass transfer process in a spray cooling tower. The mathematical model consists of the equations of motion and heat and mass transfer of water droplets and the equations of thermal and material balance of moist air, considers the polydispersity of the droplet flow and allows to calculate the cooling capacity of the cooling tower depending on the parameters of the droplet flow. The mathematical model is confirmed by the results of industrial tests of irrigation-free cooling towers. The simulation results show that the cooling capacity of a spray fan cooling tower significantly depends on the atomization dispersion and the height of the water cutting nozzles. Reducing the average diameter of the droplet flow to less than 2 mm and increasing the height of the nozzles H > 4…5 m make it possible to achieve the cooling performance of known cooling towers with nozzle. The mathematical model allows to calculate the cooling capacity of the cooling tower and determine the necessary individual parameters of the droplet flow for each type of equipment and consumers for which the specific energy costs for cooling is minimal.