bluuebunny/crossref_metadata_2025 huggingface dataset:
Completing the bootstrap program for

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-deformed massive integrable quantum field theories
Authors: Castro-Alvaredo Olalla A , Negro Stefano , Sailis Fabio
Published: June 2024

In recent years a considerable amount of attention has been devoted to the investigation of 2D quantum field theories perturbed by certain types of irrelevant operators. These are the composite field

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—constructed out of the components of the stress-energy tensor—and its generalisations—built from higher-spin conserved currents. The effect of such perturbations on the infrared and ultraviolet properties of the theory has been extensively investigated. In the context of integrable quantum field theories, a fruitful perspective is that of factorised scattering theory. In fact, the above perturbations were shown to preserve integrability. The resulting deformed scattering matrices—extensively analysed with the thermodynamic Bethe ansatz—provide the first step in the development of a bootstrap program. In this paper we present a systematic approach to computing matrix elements of operators in generalised

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-perturbed models, based on employing the standard form factor program. We show that for theories with diagonal scattering and certain types of fields the deformed form factors, factorise into the product of the undeformed ones and of a perturbation- and theory-dependent term. From these solutions, correlation functions can be obtained and their asymptotic properties studied.
The method for determining the safety factor of rock mass stability
Authors: Shchokin Vadym , Shchokina Olha , Aniskov Oleksandr
Published: June 2024

The article is devoted to determining the safety factor of rock mass stability by measuring the intensity of electromagnetic pulses in the rock mass that are derived from natural stresses within the massif as well as additional applied loads imposed on it. The rock mass stability is evaluated according to the parameters of the electromagnetic pulses. The distinctiveness of this lies method in the preliminary determination of a frequency range corresponding to a specified depth within the mining massif, facilitating the calculation of the stability reserve coefficient. Explosive events resulting from the detonation of geological formations serve as external influences for instrumental measurements of the mass. The approach entails the measurement of electromagnetic pulses and the time required for these impulses to decay from post-explosion levels to the background electromagnetic pulses level. The stability reserve coefficient of the mass is subsequently determined through an equation accounting for the internal friction angle of the geological formations, the maximum electromagnetic pulses amplitude induced by the explosion, and the duration of decay until the background electromagnetic pulses level is reached.
Controlling the dynamic characteristics of steel bunker containers for bulk materials
Authors: Bannikov Dmytro , Tiutkin Oleksii , Hezentsvei Yukhym , Muntian Antonina
Published: June 2024

The article presents the main results of research devoted to the definition and analysis of the dynamic characteristics of steel small-sized bunker containers for storing bulk materials. All studies were carried out using the finite element method with the use computer complex SCAD. The object of research was a bunker of a bypass track for feeding bulk materials with a total volume of up to 70 m3. The study analysed the natural partial frequency spectrum and the partial oscillation modes of individual load-bearing elements of the bunker. Based on the results of the data analysis, a rather high quantitative density of the natural frequency spectrum was determined. At the same time, its lower limit is about 25-30 Hz for an empty bunker capacity and decreases to 3-5 Hz when the bunker is fully loaded, which is dangerous from the point of view of the possibility of resonance phenomena. In order to qualitatively and quantitatively control the dynamic characteristics, it was proposed to change the steel strength of the structure, which made it possible to change the natural frequencies by about 15% for every 100 MPa change in steel strength for the bunker containers of the considered type.
Optimization of the technology of hoisting operations when drilling oil and gas wells
Authors: Khomenko Volodymyr , Pashchenko Oleksandr , Ratov Boranbay , Kirin Roman , Svitlychnyi Serhii , Moskalenko Alla
Published: June 2024

In the process of drilling deep wells, hoisting operations are, although unproductive, a necessary expenditure of working time and occupy 25-60% of the total time of well construction. In the case of major repair of wells, this share can be even higher. It is clear that the technical and economic indicators of drilling and capital repair of wells largely depend on the speed of execution of hoisting operations. Existing technologies and time standards for their implementation are outdated and do not take into account the current state of technology development. The article deals with the issue of optimization of the rationing of time for the execution of hoisting operations during drilling and capital repair of oil and gas wells. This problem is solved using the example of the TW-125 CA A6 well overhaul installation, which are used during overhaul of wells by branches of JSC “Ukrgazvydobuvannya”. With the help of the kinematic scheme of the installation, the rotation speeds of the winch shaft at each gear of the gearbox were determined, which made it possible to determine the optimal time for performing hoisting operations, and, as a result, to reduce the time spent on drilling, depending on the type of rock, in general.
Bench studies of the process of transporting an inverse gravel filter of block type along the well
Authors: Chudyk Ihor , Sudakova Diana , Pavlychenko Artem , Sudakov Andrii
Published: June 2024

The purpose of the study is to develop a technology for fresh water treatment in deep hydrogeological wells with productive horizons represented by medium-grained, fine-grained, and silty sands by equipping their intake part with block-type inverse gravel filters. Experimental studies were carried out using provisions of the general theory of scientific experiment and the theory of random processes. A theory concerning the possibility of equipping the water intake part of hydrogeological wells, being more than 200 m deep, with block-type inverse gravel filters using the proposed technology was further developed. For the first time, the dependence of the maximum depth of transporting block-type inverse gravel filters on the length of their section, the mass concentration of a binding agent, and the ambient temperature was established. A scope of the proposed technology was substantiated. A range of depths for equipping with block-type inverse gravel filters depending on the mass concentration of a binding agent in the polymer-gravel filter element and the length of its section was substantiated.
Network model optimization of existing mining enterprises to sustain production capacity
Authors: Brovko Dmytro , Kononenko Volodymyr , Khvorost Vasyl , Tyshchenko Vitalina
Published: June 2024

The paper is devoted to the sustainability of the production capacities of mining enterprises when extracting minerals. The timely capacity restoration is the main problem for scientists dealing with sustainable development in mining construction. The paper presents the use of network planning and optimization methods of dynamic programming to solve problems of sustaining the existing capacities of mining enterprises. The proposed methods allow for the integrated use of network planning and dynamic programming to optimize the parameters of mining operations. A network model of the technological scheme of mining operations with optimal parameters is proposed. The necessity of timely restoration of capacities of mining enterprises with the use of network planning and mathematical programming methods in solving these problems is highlighted.
The innovativeness of technologies of Industry 4.0 in the modern mining environment
Authors: Vnukova Nataliya , Tyshchenko Viktoriia , Ostapenko Viktoriia
Published: June 2024

The article presents the results of Industry 4.0 technologies in the modern mining environment. The study is aimed at identifying trends in interest in the topic of innovativeness of Industry 4.0 technologies in the modern global mining environment. To solve the problem of implementing innovations in the context of Industry 4.0 in the modern mining environment, particularly those related to mining science, two approaches were used: the Google Trends search service and the VOSviewer software. The first stage of the study identified the level of interest in mining science and Industry 4.0 in the world. According to the results of the second stage of the study, 8 strategic directions for the development of the mining industry within Industry 4.0 were identified in accordance with the qualitative composition of clusters by keywords in scientific publications, the Scopus scientometric database on the topic of innovativeness of Industry 4.0 technologies in the modern mining environment. It is proposed through amending the mining legislation in accordance with the development of Industry 4.0 technologies for the automation and digitalization of mining significantly increase interest in transformational changes.
Improvement of the device’s design for increasing the efficiency of geophysical research using the Earth’s natural pulsed electromagnetic field method
Authors: Chepurnyi Volodymyr , Liash Serhii , Hrytsai Olena , Dobrovolska Zoia
Published: June 2024

Long-term field studies have shown the high efficiency of the geophysical method of the earth’s natural pulsed electromagnetic field (NPEMFE). It is a modern and experimentally substantiated tool for studying geodynamic processes in the geological environment. Disadvantages of the known device are the low efficiency of recording the intensity level of the NPEMFE, low productivity and high costs of manual labor when performing complex registration. The application of the proposed improvements will make it possible to increase the efficiency of registration of the intensity level of the NPEMFE with an increase in productivity and a decrease in costs and the level of manual labor. The technical result is achieved due to the mobility of the structure and the provision of the possibility of simultaneous registration of the intensity level of the NPEMFE both in the frequency band and in its spatial position.
Development of the oil-contaminated wastewater treatment technology for trucking companies
Authors: Kovrov Oleksandr , Kulikova Daria
Published: June 2024

Industrial activity of trucking companies belongs to environmentally dangerous processes, which leads to the pollution of natural ecosystems, both in local and regional scale. Currently, there are strict requirements for the quality of wastewater discharged from trucking companies and car-wash sites into the outer sewer or the storm water network. This erases the urgency of the installation of local treatment facilities and implementing of the water circulating supply systems with maximum water consumption and minimum discharge of wastewater into natural water bodies. The improved technology of wastewater treatment for the trucking companies with preliminary stage of the multilayer oil-trap treatment is presented. The modeling of sedimentation process of wastewater contaminated with petroleum products allowed determine structural parameters of the proposed oil trap. The main technological parameters of wastewater treatment according to the proposed technological scheme have been determined. Implementation of the proposed technology at the trucking company allows reduce the content of petroleum products and suspended solids according to Ukrainian normative standards for water quality. This improvement minimizes the impact of contaminated wastewater on neighboring water bodies and extends capacity for water reuse in the technological process of trucking companies.
Functional materials based on high-purity zirconium compounds for applications in alternative energy
Authors: Mukhachev Anatolii , Yelatontsev Dmytro , Kharytonova Olena , Snizhnoi Hennadii
Published: June 2024

The paper presents the results of experiments on obtaining functional materials (piezoceramics, catalysts, heat-resistant coatings) based on zirconium oxide. It is shown that zirconium oxynitrate, obtained in the process of extraction separation of zirconium and hafnium, has a low content of impurities determining the quality of products based on zirconium oxide. The method of homogeneous deposition of stoichiometric zirconium compounds with alloying additives provided homogeneous salt systems for functional ceramics. The high homogeneity of the material and its physicochemical and mechanical properties allowed to obtain powders at much lower temperatures than solid-phase synthesis, providing high-quality products at low energy consumption.
Reducing operational risks during suspensions separation in rare metals technology
Authors: Yelatontsev Dmytro , Nefedov Volodymyr , Kharytonova Olena
Published: June 2024

The work presents the results of studies of the solid-liquid separation processes of different mineralogical and granulometric compositions, different viscosity and concentrations of uranium, zirconium, nitric acid, soda, sodium nitrate. It has been shown that the process of industrial filtration is impossible for finely dispersed phases due to the low separation rate. Requirements for the purity of technological solutions of uranium and zirconium for the extraction process are limited by the technological ability of the filter fabric to retain the smallest particles, including chemical compounds with a particle size of 1–5 μm. The control filtration process is only possible under pressure, for which a new disk press filter was created, which reduced the concentration of the solid phase in the filtrate to 0.06 g/L. For difficult-to-filter suspensions, a screw centrifuge was developed, which ensured minimum sediment moisture after separating the finely dispersed phase from a solution of soda and sodium silicate and created conditions for maximum extraction of zirconium and hafnium from the solid phase. The separation of water-soluble sodium silicate ensured the stability of the process of extraction separation of zirconium and hafnium and made it possible to isolate silicon oxide.
Utilization of drilling waste when drilling wells in the fields of the western oil and gas region of Ukraine
Authors: Mykhailovska Olena , Zotsenko Mykola
Published: June 2024

The article analyzes known technological solutions for storage and processing of well drilling waste. The advantage of the solution is the presence of a soil-cement coating. The authors propose to fill the waste repository with alternating layers of drilling mud and fly ash of the Darnytsia Thermal Power Plant. The authors advise to use sorbents for neutralization of petroleum products as needed. It is suggested to introduce the sorbent periodically into the mud storage barn. The thickness of the layers for disposal with the addition of ash was chosen in order to obtain optimal humidity. It is proposed to add ash removed from the Darnytsia Thermal Power Plant when arranging the walls and coating of the mud storage tank from soil cement. When adding 10% of ash by weight of cement, the compressive strength increases by 8.01% on average, and when adding 20% - by 12.57%. The results obtained show that the average compressive strength of soil cement samples increases with an increase in the percentage of fly ash content. The results were compared to samples without additives.
Details of mining beneficiation equipment made of medium manganese wear-resistant steel
Authors: Snizhnoi Hennadii , Sazhnev Volodymyr , Snizhnoi Valentyn , Mukhachev Anatoliy
Published: June 2024

For mining and beneficiation equipment, medium-manganese steel for the production of fast-wearing replaceable parts is proposed. The object of research was the effect of phosphorus on the physical and mechanical properties of austenitic manganese steels with a manganese concentration within the standard for steel 110G13L and below the regulated lower level. Phosphorus more significantly reduces impact toughness, relative elongation and relative narrowing in steels with a lower manganese content than in classic Hadfield steel. In steels with a reduced manganese content, phosphorus has a less effective influences on the tensile strength, and it has practically no effect on hardness. Reducing the phosphorus concentration to 0.025 % and below in 110G8L steel increases its main physical and mechanical properties to the level of 110G10L steel with high phosphorus (recommended for parts subject to abrasive wear). The use of 110G8LA steel with low phosphorus reduces to further reduce the costs of manganese ferroalloys in the production of fast-wearing replaceable parts of mining and beneficiation equipment. This also reduces the emission of manganese compounds with oxygen into the atmosphere, which is very harmful to the environment and the human body.
Numerical study of time-dependent stresses in the floor of the stope with powered support
Authors: Krukovskyi Oleksandr , Krukovska Viktoriia , Kostrytsia Andrii
Published: June 2024

When sections of the powered support are clamped in the stope, one of the ways to move them is to explode the rock under them. In the case when there is outburst-prone sandstone in the seam floor, blasting operations becomes dangerous and it is necessary to study the stress field in the host rocks. In this work, a numerical study of the time-dependent stress field in the floor of the stope with powered support is performed. Distributions of values of geomechanical parameters characterizing the stress field and zones of inelastic deformations at different time steps are given. Graphs of changes in these parameters in the floor of the stope are plotted. The minimum time for unloading sandstone at the place of drilling the hole for explosive charge is calculated. It is shown that in front of the mine face plane, the sandstone in the seam floor is in a uniform compressed state; all components of the stress field are close to unity. However, they start to decrease already 2.5 m before the mine face plane. At the hole drilling site, the maximum stress is 0.77γH, the minimum stress is 0.35γH at a depth of 1 m for given conditions.
Comparison of the reliability of strength limit calculation methods for prismatic samples with different spreading of normal contact stresses in their wedge failure shape
Authors: Vasyliev Leonid , Vasyliev Dmytro , Malich Mykola , Rizo Zakhar , Kress Denys
Published: June 2024

This article explores methods for calculating the strength limits of solid objects subjected to compression. Traditionally, two stress distribution patterns are used: the exponential pattern by E.P. Unksov and the linear pattern by L. Prandtl. The authors introduce an enhanced stress distribution method. They compare the accuracy of these methods in calculating strength limits and constructing “normal stress - longitudinal strain” diagrams for wedge-shaped failures in rock samples. Four properties are considered: shear strength, coefficients of internal and external friction, and elasticity modulus. The results show that, with an external friction coefficient up to 0.3, all methods yield similar accuracy in strength limit calculations and ultimate stress-strain curves. Some curves exhibit stress drops, explained by a transition from convex to concave slip lines during failure. Additionally, there are hardening curves in the ultimate curves without theoretical justification. The comparison of calculated strength limits with experimental data confirms the method’s accuracy: 13.7% error for the exponential method, 11.4% for the linear method, and 8.1% for the enhanced distribution, especially for low contact friction values (up to f
c=0.3).
Prompt determination of predictive parameters for mining-technogenic landscape objects
Authors: Petlovanyi Mykhailo , Ruskykh Vladyslav , Sai Kateryna , Malashkevych Dmytro
Published: June 2024

The presented research is aimed at developing tools for quickly determining the geometric parameters of mining-technogenic landscape objects to solve various geotechnical and engineering problems, such as reclamation of lands disturbed by mining operations, as well as accumulated industrial waste utilization. The task of quickly determining the geometric parameters of the mining-technogenic landscape forms is proposed to be performed using the Blender software product for 3D-modeling and the Blender GIS Addon. The 3D models for mining-technogenic landscape objects have been constructed. In addition, the volumes of mined-out space at the granite quarry, the earth’s surface failure zone at the iron-ore mine and the mine waste rock dump have been determined. As a result, the values obtained were compared with actual data. It has been found that with the correct display of mining-technogenic landscape objects in the Google geospatial system, the proposed tools based on the Blender GIS Addon achieve high accuracy in determining parameters. The proposed method is predictive and cannot be independent, and it must be used in synthesis with surveying measurements of the parameters for mining-technogenic landscape objects and is a kind of a certain addition. However, it allows solving large-scale strategic problems in geoengineering.
Ways to reduce the risk of emergencies on belt conveyors operating in mining enterprises
Authors: Kiriia Ruslan , Smirnov Andrii , Mostovyi Borys , Mishchenko Tamara , Novikov Leonid
Published: June 2024

Since the majority of emergencies on belt conveyors of mining enterprises are associated with the conveyor framework, the article considers the failures of its elements - roller supports. The process of functioning of the framework is presented as a Markovian process of death and reproduction for a system of n parallel connected elements (roller supports) with intensity of failure and recovery λ
r and μ
r, respectively. The maximum permissible number of non-working roller supports, as well as the required number of roller supports replacement per shift to prevent an emergency on the conveyor, are determined. The value of the risk of conveyor framework failure K was also determined. Thus, for the given operating conditions, load flow characteristics and conveyor parameters, it is possible to calculate the maintenance intensity at which the risk of an emergency is minimal. This allows for efficient planning of belt inspections and repairs. To eliminate the risk of emergencies a patent-pending method for monitoring the technical condition of a belt conveyor framework by automatically monitoring the number of idle rollers on the framework has been developed. This prevents accidents caused by belt breakage and fire, as well as loss of traction of the conveyor drive.
Improving the efficiency of gear grinding technology for mine conveyor drives
Authors: Novikov Fedir , Polyanskyy Volodymyr , Yermolenko Oleksiy , Ivashura Andrii , Yermolenko Oksana
Published: June 2024

The aim of this work is to develop a mathematical model of the gear grinding process using the method of high-performance profile copying and determine the optimal parameters of grinding modes according to the temperature criterion. It is shown that in order to ensure defect-free machining of gears under deep grinding conditions, it is necessary to significantly reduce the rate of the feed speed of the grinding wheel along the tooth of the gear wheel. For a grinding depth of 0.4 mm, it should be equal to 2.27 m/min. In this case, the machining productivity can be increased up to 5 times with the simultaneous elimination of the formation of sticking, microcracks and other temperature defects on the machined gear surfaces. This processing effect is achieved by using a modern HOFLER RAPID 1250 gear grinding machine and highly porous abrasive wheels, which are characterized by high cutting capacity. Thanks to the improved quality of gear processing, the quality and performance of manufactured mine conveyor drives (planetary gearboxes with a power of more than 200 kW) have been improved, and the number of repairs required in harsh mine conditions has been significantly reduced.
Increasing the underground coal gasification efficiency using preliminary electromagnetic coal mass heating
Authors: Lozynskyi Vasyl , Falshtynskyi Volodymyr , Kozhantov Arystan , Kieush Lina , Saik Pavlo
Published: June 2024

The purpose of this research is to explore the possibilities of using a high-frequency electromagnetic field for heating coal seams in the context of underground coal gasification. The research is based on mathematical models that take into account the physical parameters of the electromagnetic field. The methodology includes the calculation of thermal powers, exposure duration, temperature profiles and reaction rates. The research results indicate significant potential for using high-frequency electromagnetic field for coal seam pre-heating. Possibilities of using a high-frequency electromagnetic field for heating the mass in the context of underground coal gasification have been explored. The mathematical models developed and calculations performed broaden the understanding of heating processes in such systems. It has been determined that field parameters, such as frequency and power, influence the heating efficiency and temperature distribution. The obtained scientific results present new opportunities to increase the efficiency of underground coal gasification as an alternative energy source and will contribute to achieving a more efficient and sustainable future energy supply. The use of a high-frequency electromagnetic field can be useful when gasifying low-grade or low-thickness coal seams, when there is a need to intensify the gasification process.
The performance analysis of deep learning algorithms for modelling and forecasting the particulate matter (PM10) in the eastern part of Turkey
Authors: Batur Maryna , Babii Kateryna
Published: June 2024

The main purpose of this study is to select the most reliable nonlinear computational model to predict the particulate matter (PM10) concentrations. Time series data of three years PM10 concentrations were used as input variable. For the prediction, three different types of dynamic nonlinear autoregressive models were built and compared. These models are the Levenberg-Marquardt algorithm, the Bayesian Regulization algorithm, and the Scaled Conjugate Gradient algorithm. For each of these algorythms, various settings were adopted with the subsequent statistical analysis. To analyse the model performance, we used mean prediction error, root mean square error, and correlation coefficient. The lowest root mean square errors were found for the Levenberg-Marquardt algorithm with 15 neurons, for the Bayesian Regularization and for the Scaled Conjugate Gradient algorithm with 20 neurons in hidden layer. In our study, we focused on the long-term forecast of stationary dynamic time series data and on the large amount of data, which is presented as a scientific novelty. Additionally, we determined the main model parameters that most improve quality in terms of training and network capacity. Therefore, the derived forecasting model can be used as a priori for air quality management and regulations aimed on the reducing of pollutant level.
Interchangeability of various combustible gases and adaptation of gas-using equipment for their efficient combustion
Authors: Kolienko Anatolii , Ahmednabiev Rasul , Demchenko Oksana , Hukasian Olha , Semko Volodymyr
Published: June 2024

The article presents the results of studies, the purpose of which is to substantiate the possibility of using a wide class of different combustible gases in one gas-using equipment and to develop recommendations for changing the design and operational parameters of such gas-using equipment in the event of a transition from one type of non-interchangeable combustible gases to another. The methodology of the work is based on a critical analysis of the available data on the issue of interchangeability of combustible gases, as well as our own theoretical and experimental studies. Dependencies have been obtained that permit to determine the possibility of switching gas-using equipment from one type of gas to another. Recommendations have been developed on the permissible content of hydrogen in a mixture with natural gas, ensuring the efficient, safe and environmentally friendly use of such fuel in household and industrial heating devices. Scientific and practical results of the work permit to carry out a low-cost reconstruction of gas-using equipment from one gas to another, including the transition to combustible gas containing hydrogen.
Utilization of phosphogypsum from industrial dumps as an element of environmentally safe energy- and resource-conserving technologies
Authors: Pikarenia Dmytro , Orlinska Olha , Hapich Hennadii , Rudakov Leonid , Chushkina Iryna , Mazurenko Roman
Published: June 2024

The paper discusses the problem of disposal and processing of phosphogypsum dumps as an element of environmentally safe energy- and resource-conserving technologies. The process of impact and possibility of phosphogypsum pre-treatment with weak electric fields to improve its physical and mechanical properties was studied. Two samples of different origin phosphogypsum, which are located in dumps on the territory of the Kamianske City (Ukraine), were used as research material. The research was conducted on samples of the following fractions: 1.0–2.0, 0.4–1.0, 0.1–0.4 mm. Further, balls were formed from the treated phosphogypsum and raw materials to study their compressive strength. The experiment was performed on a pellet strength meter, which operates in the range of 0–2.5 kgf/grain. Phosphogypsum balls, treated with electric current, did not collapse with the maximum values of the device. According to the research results, it was established that preliminary treatment with a low electric current leads to a decrease in the dehydration temperature of phosphogypsum, and the subsequent hydration allows to obtain a material with higher compressive strength properties. This substantiates the potential possibility of involving research results to obtain a cheaper product and will allow to liquidate multi-ton deposits of phosphogypsum.
The durability increasing of high-wear cast parts of mining and processing equipment
Authors: Shalomeev Vadim , Brykov Mykhailo , Sheiko Serhii , Matiukhin Anton , Yepishkin Oleksandr , Kulabnieva Olena , Tytov Oleksandr
Published: June 2024

The analysis of the operation of rapidly wearing parts of the ore-grinding equipment was carried out. It has been established that unloading grates and ladles are fast-wearing parts of layered fracture mills and determine their downtime between repairs. The possibility of improving the mechanical properties of medium-carbon steel 40HL due to the reduction of harmful impurities is shown. The effects of modification with aluminum, vanadium, calcium, and rare earth metals on structural formation, mechanical, and operational properties of steel are investigated. It was established that the complex modification of cast steel 40HL (0.04…0.1% vanadium, 0.15% silicon calcium and 0.15% rare earth metals) allows to significantly increase its mechanical properties and wear resistance. The separate and joint influence of aluminum, vanadium, calcium and rare metals on the austenite grain size and hardening of steel was studied. The proposed modification technology makes it possible to obtain a fine grain, through-hardening of castings and ensure reliable and long-lasting operation of ball mills.
A new method of oil and water well completion involving the implosion effect
Authors: Chudyk Ihor , Biletskiy Marian , Ratov Boranbay , Sudakov Andrii , Borash Ardak
Published: June 2024

Features of colmatation zones of a productive formation in terms of rotary drilling by drilling muds are considered. A brief analysis of the most popular decolmatation methods is performed. Special attention is paid to the decolmatation method involving implosion effect. An example of one of the existing installations is represented with following consideration of its application features. A new principally different installation, free from the disadvantages found in the available one, is considered; a patent for the installation is obtained in Kazakhstan. It does not involve tubing with its packer and wellhead sealing. It also does not require a compressor and its manifold. Characteristic features of the newly developed installation for creating implosion effect are represented; its operation at producing both single and any number of repeated implosion acts is examined. A mathematical analysis is performed to calculate the empty space limits required for the implosion effect by a criterion to prevent casing string collapse by hydrostatic pressure of the drilling mud remained in the annular space. An example of dependency of the maximum permitted length of empty space in the casing string on its mechanical strength and its wall thickness, calculated by means of a computer program, is represented.
Methods of finding and developing underground water resources
Authors: Zmiievska Kristina , Zmiievskyi Artur
Published: June 2024

The paper presents the methods of finding for underground water resources using the observation method of the natural impulsive electromagnetic field of the Earth and substantiates the technology of drilling water wells using the down-the-hole drilling method. The most promising sources for extracting of high-quality drinking water, namely fractured water, are considered. It is shown that these methods can be applied in mining areas with an open type of mineral development in the crystalline rocks of the Ukrainian Shield, given the strength of the rocks in geological fault zones, which exceeds f=10 on Professor Protodyakonov’s scale. Previously, water resources in such collector formations were not considered promising due to the difficulty of drilling. The flow rate for water is directly proportional to the final diameter of the drilling wells, that is, the larger the final diameter of the well, the larger the diameter of the filtration column that can be installed, and the greater the discharge that can be obtained. Therefore, equipment with diameters of 200 mm and larger is used for water wells construction.
The use of secondary heat resources during the accumulation of compressed air in closed mining workings
Authors: Kirsanov Mykhailo , Slobodiannykova Inna , Gupalo Olena , Podoliak Kostiantyn
Published: June 2024

The article considers the possibility of energy accumulation in mining workings in order to reduce the consumption of fossil organic fuel by the mining enterprise itself. For this purpose, the authors propose to accumulate compressed air in closed mine workings using secondary heat resources to generate additional electricity. The energy management of mining enterprises can be equipped with freon steam turbines which implement the Rankine thermodynamic cycle to obtain additional electricity from secondary heat. To measure the efficiency of the process, the air mast be compressed isothermally. The compression must be carried out in several stages, and the air must be cooled after each stage. Taking into account the development of energy storage technologies in the form of compressed air in specially prepared closed mining workings, the required air pressure can be from 70 to 90 at. The article assesses the possibility of using a secondary heat resource during air compression at mining enterprises. It is shown that the use of freon steam turbines during the accumulation of compressed air in underground pressure accumulators increases the subsequent production of electricity during the operation of the air turbine by 7.6% during the day.
Signs of dynamic nonlinearity of the coal dielectrics depolarization upon excitation in electric and magnetic field
Authors: Balalaiev Oleksandr , Burchak Oleksandr , Sierikov Yurii , Baranovskyi Volodymyr
Published: June 2024

The authors conducted a series of experiments on samples treated immediately before measurements with a constant magnetic field of a neodymium magnet and/or an alternating electric field. The experiment has shown complex dynamics of electric potential with alternating polarity relative to the base exponential depolarization curve. The variety of responses to different types of excitation, and the irregular and unpredictable nature of fluctuations suggest that these are varieties of the same phenomenon – the nonlinear dynamics of ferroelectric domains. The applied methods of statistical processing of the cumulative data array suggest that the invariance of the relaxation dynamics of the accumulated electric potential after excitation can be characterized by three related nonlinear differential equations of the first order. The impact of an alternating electric field may consist in bringing the dipoles of ferroelectric domains in the molecular coal structure into a state of unstable equilibrium with their slow return to their original position. The impact of a constant magnetic field is determined by the interaction of the external magnetic field with the magnetization induced due to time-varying electric polarization. In any case, the observed fluctuations are due to changes in the domain structure topology of the condenser with coal matter.
Amplification effects of ground motion due to the local geology of the building site in the cities of Kyiv, Kryvyi Rih, Odesa
Authors: Pigulevskiy Petro , Semenova Yuliia , Lisovyi Yurii , Kendzera Oleksandr , Kravets Serhii
Published: June 2024

The results of the research presented in the article elucidate the importance of taking into account the amplitude-frequency characteristics of soil stratum models in the context of seismic safety of construction objects on the territory of Ukraine, in different regions. The presented results of the analysis of the calculated amplitude-frequency characteristics of models of soil environments for different regions of Ukraine reveal that the amplification of vibrations by soils has a complex nature that depends on many factors and can differ significantly for different construction sites. We have shown that during the earthquake-resistant design of buildings and structures, it is necessary to properly take into account the properties of soil complexes under the research site, which can significantly increase oscillations at “resonant” frequencies. The article examines in detail the features of amplitude-frequency characteristic models of soil strata for different geological conditions in Kyiv, Kryvyi Rih and Odesa. The purpose of this study is to compare these characteristics and develop recommendations for reducing risks associated with seismic hazards.
Tunable atomic spontaneous radiation in cylindrical waveguide
Authors: Liu Yu-Wei , Zhao Li-Ming , Zhou Yun-Song
Published: June 2024

The chiral interaction between light and matter has brought chiral quantum optics into a flourishing stage. Here, we explore the perfect chiral interaction between the atoms with elliptically polarized dipoles and waveguide modes, and find that ideal unidirectional radiation can be obtained by adjusting the position and polarization of atoms. When there are two waveguide modes in the system, by controlling the polarization of the dipoles, the dipoles can radiate not only the unidirectional single waveguide mode, but also two seperated waveguide modes.
Projected changes in heat, extreme precipitation, and their spatially compound events over China’s coastal lands and seas through a high-resolution climate models ensemble
Authors: Zhang Runkai , Zhu Jinxin , Wang Dagang , Wei Chunzhu , Dong Cong
Published: June 2024

China’s coastal lands and seas are highly susceptible to the changing environment due to their dense population and frequent economic activities. These areas experience more significant impacts from climate change-induced extreme events than elsewhere. The most noticeable effects of climate change are extreme high temperatures and extreme precipitation. We employ an ensemble of RCMs (Regional Climate Models) to investigate and project changes in temperature, precipitation, and Compound Heat-Precipitation Extreme events (CHPEs) over selected China’s coastal lands and seas for both historical (1985–2004) and future periods (2080–2099). The multi-model ensemble projects that daily temperature extremes will increase by 2.9 °C to 5.4 °C across China’s coastal lands and seas, with land areas showing a higher temperature increase than marine areas. Extreme precipitation shows a high geographical heterogeneity with a 2.8–3.9 mm d−1 reduction over the 15–25°N marine areas while a 2.2–5.4 mm d−1 increment over the 25°N-35°N land areas. We use the Clausius–Clapeyron relationship to reveal that the peak of daily extreme precipitation will increase by 2–7 mm d−1 and the temperature at which extreme precipitation peaks will increase by 2 °C to 6 °C by warming. The land area of 25–30°N has the highest peak precipitation increase of 9.87 mm d−1 and a peak temperature increase of 6 °C. As precipitation extremes intensify with daily temperature extremes increase, CHPEs are projected to occur more frequently over both land and marine areas. Compared with the historical period, the frequency of CHPEs will increase by 40.9%-161.2% over marine areas, and by 36.2%-163.6% over land areas in the future. The 15–20°N area has the highest frequency increase of CHPE events, and the 25–30°N area has the largest difference in frequency increase under two different scenarios. It indicated that the 25–30°N area will be more easily affected by climate change.
Divergent structural leaf trait spectra in succulent versus non-succulent plant taxa
Authors: Mozzi Giacomo , Crivellaro Alan , Blasini Davis E , Vásquez-Cruz Marilyn , Hernández-Hernández Tania , Hultine Kevin R
Published: June 2024

Background and Scope

Plant functional traits are the result of natural selection to optimize carbon gain, leading to a broad spectrum of traits across environmental gradients. Among plant traits, leaf water storage capacity is paramount for plant drought resistance. We explored whether leaf-succulent taxa follow trait correlations similar to those of non-leaf-succulent taxa to evaluate whether both are similarly constrained by relationships between leaf water storage and climate.

Methods

We tested the relationships among three leaf traits related to water storage capacity and resource use strategies in 132 species comprising three primary leaf types: succulent, sclerophyllous, and leaves with rapid returns on water investment, referred to as fast return. Correlation coefficients among specific leaf area (SLA), water mass per unit of area (WMA), and saturated water content (SWC) were tested, along with relationships between leaf trait spectra and aridity determined from species occurrence records.

Results

Both SWC and WMA at a given SLA were ~10-fold higher in succulent leaves than in non-succulent leaves. While SWC actually increased with SLA in non-succulent leaves, no relationship was detected between SWC and SLA in succulent leaves, although WMA decreased with SLA in all leaf types. A principal component analysis (PCA) revealed that succulent taxa occupied a widely different mean trait space than either fast-return (P < 0.0001) or sclerophyllous (P < 0.0001) taxa along the first PCA axis, which explained 63 % of mean trait expression among species. However, aridity only explained 12 % of the variation in PCA1 values. This study is among the first to establish a structural leaf trait spectrum in succulent leaf taxa and quantify contrasts in leaf water storage among leaf types relative to specific leaf area.

Conclusions

Trait coordination in succulent leaf taxa may not follow patterns similar to those of widely studied non-succulent taxa.
It’s an Imagined Fuṣḥatopia: Teacher Language Ideologies and Multilingual Practices in Arabic Heritage Learning in the United States
Authors: Abourehab Yousra
Published: June 2024

This article examines teacher ideologies and multilingual practices in teaching Arabic as a heritage language in the USA. Using indexicality and its nexus to language ideologies, it identifies the key index values assigned to Standard Arabic (SA) and how these shape teacher positioning for teaching Arabic heritage. The article also analyzes the extent to which these ideologies are congruent or incongruent with their classroom practices. The findings of in-depth semi-structured interviews showed teachers’ veneration of SA with representations that index ‘perfection’, ‘majesty’, ‘purism’, and ‘generosity’. Although teachers seemed tolerant of using Arabic dialects strategically, their overall positioning supported teaching SA and minimized teaching dialects. Drawing on data from a larger corpus of around 25 hr of classroom video recordings, teachers showed ubiquitous multilingual and multidialectal practices in classroom discourse. With its dual focus on language ideologies and practices, this article enriches the discussion about the idealization of SA (fuṣḥatopia) as restricting the potential of Arabic dialects as important resources for learning SA. It also disrupts the linguistic hierarchy between SA and the dialects.
Outcomes in Subfascial Versus Subglandular Planes in Breast Augmentation: A Systematic Review and Meta-analysis
Authors: Yuan Morgan , Kim Patrick , Gallo Lucas , Austin Ryan E , Lista Frank , Ahmad Jamil
Published: June 2024

Breast augmentation is the most commonly performed aesthetic surgery procedure in women worldwide. The use of the subfascial plane has been suggested to decrease the incidence of capsular contracture compared with the subglandular plane, while simultaneously avoiding the complication of animation deformity in the subpectoral plane. The aim of this systematic review and meta-analysis was to compare the adverse outcomes of subfascial vs subglandular planes in breast augmentation. This review was registered a priori on OSF (https://osf.io/pm92e/). A search from inception to June 2023 was performed on MEDLINE, Embase, and CENTRAL. A hand search was also performed. All randomized and comparative cohort studies that assessed the use of the subfascial plane for breast augmentation were included. Outcomes evaluated included the incidences of seroma, hematoma, infection, rippling, capsular contracture, and revision surgery. Ten studies were included in this systematic review. Three randomized controlled trials and 7 comparative cohort studies were used for quantitative synthesis. There was a significant difference favoring subfascial compared with subglandular planes in the incidence of hematoma, rippling, and capsular contracture. All included studies had a high risk of bias. The current evidence suggests that the subfascial plane for breast augmentation decreases the risk of capsular contracture, hematoma, and rippling compared with the subglandular plane. Further randomized evidence with high methodological rigor is still required to validate these findings.

Level of Evidence: 3