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Articles 541 - 570 of 38760

Full-Text Articles in Physical Sciences and Mathematics

Leveraging Transformer Models For Genre Classification, Andreea C. Craus, Ben Berger, Yves Hughes, Hayley Horn May 2024

Leveraging Transformer Models For Genre Classification, Andreea C. Craus, Ben Berger, Yves Hughes, Hayley Horn

SMU Data Science Review

As the digital music landscape continues to expand, the need for effective methods to understand and contextualize the diverse genres of lyrical content becomes increasingly critical. This research focuses on the application of transformer models in the domain of music analysis, specifically in the task of lyric genre classification. By leveraging the advanced capabilities of transformer architectures, this project aims to capture intricate linguistic nuances within song lyrics, thereby enhancing the accuracy and efficiency of genre classification. The relevance of this project lies in its potential to contribute to the development of automated systems for music recommendation and genre-based playlist …

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Crisis Management: Unveiling Information And Communication Technologies’ Revamped Role Through The Lens Of Sub-Saharan African Countries During Covid-19, Ruthbetha Kateule, Egidius Kamanyi, Mahadia Tunga May 2024

Crisis Management: Unveiling Information And Communication Technologies’ Revamped Role Through The Lens Of Sub-Saharan African Countries During Covid-19, Ruthbetha Kateule, Egidius Kamanyi, Mahadia Tunga

The African Journal of Information Systems

The management of COVID-19 pandemic has revealed inefficiencies in coordinating global response, particularly in African countries. Therefore, creating an urgent need to examine the literature on Information and Communication Technologies (ICT) in crisis management to appreciate its contextual role. Employing a systematic review, using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA), this paper critically assessed the extent of the use of ICT in crisis management in Africa’s response to COVID-19 to reconstruct its resilience against future crises. Findings indicate that while countries with limited ICT infrastructure faced considerable challenges in utilizing ICT solutions in COVID-19 management, countries …

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Nickel-Catalyzed Α-Arylation Of Α-Cyanoacetates Enabled By Electrochemistry, Zi-Meng Li, Zhang-Jian Li, Anat Milo, Ping Fang, Tian-Sheng Mei May 2024

Nickel-Catalyzed Α-Arylation Of Α-Cyanoacetates Enabled By Electrochemistry, Zi-Meng Li, Zhang-Jian Li, Anat Milo, Ping Fang, Tian-Sheng Mei

Journal of Electrochemistry

β-Amino acids have a wide range of applications in the field of pharmaceuticals. Utilizing a combination strategy of nickel catalysis and paired electrolysis, a catalytic α-arylation protocol of carbonyl compounds has been developed. This protocol affords various a-aryl-a-cyanoacetates, which can be reduced to high-value-added α-aryl-β-amino acids. The cross-coupling reaction of electron-deficient aryl bromides with a-cyanoacetates achieves the expected products with good yields and functional group compatibility under mild conditions. Excessive electron-richness in initial aryl bromides facilitates the self-coupling of desired products. DFT calculations confirm that the presence of electron-rich aryl substitutions decreases the …

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Linear Ode Systems Having A Fundamental Matrix Of The Form F(Mt), Kevin L. Shirley, Vicky W. Klima May 2024

Linear Ode Systems Having A Fundamental Matrix Of The Form F(Mt), Kevin L. Shirley, Vicky W. Klima

CODEE Journal

We interweave scaffolded problem statements with exposition and examples to support the reader as they explore specific linear systems of differential equations with variable coefficients, $\vec{x}'(t)=A(t)\vec{x}(t)$ and initial value $\vec{x}(0)$. We begin with a constant $n\times n$ matrix $M$ and a real or complex-valued function $f$, analytic at the eigenvalues of $M$ with $f(0) = 1$, and construct a linear system of differential equations with solutions $x(t)=f(Mt)\vec{x}(0)$, where $t$ is a parameter in some interval including zero. In general, the solutions to the resulting non-autonomous system are more difficult to analyze than solutions to the constant coefficient case. However, some …

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Comparison Of Ligands In Palladium-Catalyzed Electrochemical Allyl 4-Pyridinylation, Wei-Jie Ding, Chun-Hui Yang, Zhong-Tao Feng, Shi-Rong Lu, Xu Cheng May 2024

Comparison Of Ligands In Palladium-Catalyzed Electrochemical Allyl 4-Pyridinylation, Wei-Jie Ding, Chun-Hui Yang, Zhong-Tao Feng, Shi-Rong Lu, Xu Cheng

Journal of Electrochemistry

4-CN-pyridine is a widely applied 4-pyridinylation reagent for diverse transformations. Conventionally, the reaction proceeds via an open-shell radical cross-coupling pathway. Following our previous study, in this work, we report the Pd-catalyzed allyl 4-pyrinylation reaction under electrochemical conditions. The reaction proceeds via radical-polar crossover pathway in which the role of phosphine ligand in reactivity and selectivity was extensively investigated.

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Novel In Situ Synthesis Of Copper Oxide Nanoparticles In Epoxy Network: Kinetics, Composite Mechanical And Dielectric Properties, Elena Bobina, Maxim Danilaev, Safaa.M.R.H. Hussein, Sergey Karandashov, Vladimir Kuklin, Ivan Lounev, Konstantin Faizullin May 2024

Novel In Situ Synthesis Of Copper Oxide Nanoparticles In Epoxy Network: Kinetics, Composite Mechanical And Dielectric Properties, Elena Bobina, Maxim Danilaev, Safaa.M.R.H. Hussein, Sergey Karandashov, Vladimir Kuklin, Ivan Lounev, Konstantin Faizullin

Karbala International Journal of Modern Science

>Mechanical properties of polymer composites with dispersed nanoparticles (CDNP) depend on interaction between the nanoparticles and the polymer matrix. Strength of polymer composites significantly decreases when there is no interaction between dispersed nanoparticles and the polymer. This limits the application of functional polymer composites with dispersed nanoparticles. In this study, CDNP based on ED-20 epoxy resin with dispersed copper oxide nanoparticles was obtained.These nanoparticles were synthesized in epoxy resin before curing: the nanoparticles were obtained by decomposition of copper hydroxide by heating its solution in ED-20 resin.The kinetics of copper oxide nanoparticles formation in CDNP samples were studied using two …

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Elm And Lightgbm: A Hybrid Machine Learning Technique With Intelligent Iot To Predict The Cardiovascular Disease, Gorapalli Srinivasa Rao, G Muneeswari May 2024

Elm And Lightgbm: A Hybrid Machine Learning Technique With Intelligent Iot To Predict The Cardiovascular Disease, Gorapalli Srinivasa Rao, G Muneeswari

Karbala International Journal of Modern Science

Cardiologists can more accurately classify a patient's condition by performing an accurate diagnostic and prognosis of cardiovascular disease (CVD). The clinical diagnosis, and therapies processes within the medical field have been substantially accelerated by ML-based approaches enabled by IoT-based systems. This structure is based on IoT-based system with enabled ML approach. This study investigates an approach known as ensemble categorization, which enhances the precision of weak algorithms by integrating multiple classifiers. For effective CVD classification, we utilized Ensemble learning machine (ELM) and Light GBM. The appropriate traits are chosen to speed up the categorization process using the Gorilla Troops Optimizer …

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Numerical Simulations For A Non-Newtonian Power Law Fluids In Oscillating Lid-Driven Square Cavity, Nusrat Rehman, Rashid Mahmood, Sara Fatima May 2024

Numerical Simulations For A Non-Newtonian Power Law Fluids In Oscillating Lid-Driven Square Cavity, Nusrat Rehman, Rashid Mahmood, Sara Fatima

International Journal of Emerging Multidisciplinaries: Mathematics

Fluid flows in cavities has been one of the important benchmark problems in Computational Fluid Dynamics to test and validate open source and commercial codes. Fluid mixing plays a pivotal role in Chemical and Process engineering research. Cavities have emerged as valuable assets in facilitating mixing processes. Enhancement of mixing within cavities can be achieved through various means, including the installation of baffles within the domain, utilization of stirrers, and implementation of an oscillating lid. We focus on oscillating lid driven flows in cavities in this thesis including the non-Newtonian fluid (Power law model). Numerical simulations are performed for top …

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Deposition Of Organic And Inorganic Carbons On The Turkish Continental Margins (1984–1996), Vedat Edi̇ger, Di̇lek Edi̇ger May 2024

Deposition Of Organic And Inorganic Carbons On The Turkish Continental Margins (1984–1996), Vedat Edi̇ger, Di̇lek Edi̇ger

Turkish Journal of Earth Sciences

This study reevaluates the published total inorganic carbon (TIC) and total organic carbon (TOC) percentages of 695 seafloor sediment samples collected from the continental margins of the Black Sea, Sea of Marmara, Aegean Sea and Mediterranean Sea between 1984 and 1996. An inverse relationship is observed between the average TIC and TOC percentages in the four seas surrounding Türkiye. The explanation for this phenomenon is closely connected to the terrestrial, marine, climatic, and environmental factors of the continental margins from which the samples were collected.

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Derivation Of A 1-D Seismic Velocity Model For The Lake Van Region, Mehveş Feyza Akkoyunlu, Bülent Kaypak, Bülent Oruç, Doğan Kalafat May 2024

Derivation Of A 1-D Seismic Velocity Model For The Lake Van Region, Mehveş Feyza Akkoyunlu, Bülent Kaypak, Bülent Oruç, Doğan Kalafat

Turkish Journal of Earth Sciences

We present a detailed one-dimensional (1-D) velocity model of the Lake Van Basin and its surrounding region, alongside precise hypocenter locations, utilizing seismic data from the aftershocks of the 23 October 2011 Lake Van earthquake (Mw = 7.1). The 1-D minimum velocity model is computed by the VELEST program by analyzing body wave traveltimes and station corrections. Encompassing a geographical area of 180 × 90 km² centered around Lake Van, the study incorporated seismic data from 10 newly deployed stations, complementing the existing network of the Kandilli Earthquake Research Institute. A comprehensive manual analysis was conducted on a dataset comprising …

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Enhanced Dip Angle Map Using Kuwahara And Gaussian Filters: An Example From Burdur Region, Türkiye, Özkan Kafadar, Erdi̇nç Öksüm May 2024

Enhanced Dip Angle Map Using Kuwahara And Gaussian Filters: An Example From Burdur Region, Türkiye, Özkan Kafadar, Erdi̇nç Öksüm

Turkish Journal of Earth Sciences

Recently, many edge detection and enhancement techniques have been used to transform geophysical data into a more suitable form for interpretation. The dip angle, a surface-derived attribute that has been frequently used in the interpretation of seismic data, is one of these transforms, and recently, it has started to be utilized as an edge detector in the interpretation of potential field data. In this study, it is proposed to use the potential field data filtered using the Kuwahara and Gaussian filters to obtain clearer and more detailed edges from both the conventional dip angle and its rescaled version. Two synthetic …

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Geomagnetic Response To The Earthquake In Türkiye And Syria On February 6, 2023, Svetlana Riabova, Sergey Shalimov May 2024

Geomagnetic Response To The Earthquake In Türkiye And Syria On February 6, 2023, Svetlana Riabova, Sergey Shalimov

Turkish Journal of Earth Sciences

The disturbances in the lower ionosphere during the strong earthquake in Türkiye and Syria and its strongest aftershock on February 6, 2023, are analyzed using data from ground-based magnetometers. The observation points are located at distances 700 to 1600 km from the epicenter of the seismic event. As a characteristic of the ionospheric response to these events, variations in the magnetic field have been analyzed at the İznik, Grocka, Panagjurishte, and Surlari magnetic observatories. Earthquake epicenter is known to be a source of both seismic Rayleigh waves and atmospheric acoustic-gravity waves. Using the difference in velocities, at which these waves …

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Stochastic 1-D Reactive Transport Simulations To Assess Silica And Carbonate Phases During The Co2 Reinjection Process In Metasediments, Selçuk Erol May 2024

Stochastic 1-D Reactive Transport Simulations To Assess Silica And Carbonate Phases During The Co2 Reinjection Process In Metasediments, Selçuk Erol

Turkish Journal of Earth Sciences

One proposed method to mitigate carbon emission is to mineralize the CO2 in deep geothermal reservoirs while mixing the coproduced CO2 with the effluent fluid for reinjection. The injection fluid temperature fluctuates due to the mixing process between CO2-charged water and the effluent fluid, and compressor interruptions change the thermodynamic conditions that influence the fluid-rock interaction in the reservoir. Mineral dissolution or precipitations are associated with changes in permeability and porosity that affect the flow and, eventually, the lifespan of the reservoir. A combined stochastic–reactive transport simulation approach is useful for inspection purposes. Moreover, the stochastic algorithm validates the deterministic …

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Carboniferous Graptolites (Hemichordata: Graptolithina) From The Dnipro-Donets Depression And Donets Basin, Ukraine, Vitaly Dernov May 2024

Carboniferous Graptolites (Hemichordata: Graptolithina) From The Dnipro-Donets Depression And Donets Basin, Ukraine, Vitaly Dernov

Turkish Journal of Earth Sciences

Remains of the Carboniferous graptolites ?Ptiograptus sp. and Dictyonema sp. are described from the Donets Basin and the border zone of the Dnipro-Donets Depression and Donets Basin (eastern Ukraine). These graptolites were found in the Mezhova (Visean, Mississippian) and Avilovka (Kasimovian, Pennsylvanian) formations. Dictyonema sp. from the Avilovka Formation is probably the youngest dendroid graptolite to date. The analysis of geological data allowed to make a reasonable assumption about the Late Devonian rather than the Carboniferous age of the graptolite fauna from the Englewood Formation of South Dakota (USA) and the Tournaisian rather than the Cisuralian age of graptolites from …

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Double Acting Liberation Of Ni And Co In The Pre-Treatment Process To Increase Recovery Of Nickel From Low-Grade Nickel Laterite, Eni Febriana, Muhamad Irham Mulyadi, Wahyu Mayangsari, Januar Irawan, Iwan Setiawan, Ahmad Maksum, Florentinus Firdiyono, Soesaptri Oediyani, Agus Budi Prasetyo, Johny W. Soedarsono May 2024

Double Acting Liberation Of Ni And Co In The Pre-Treatment Process To Increase Recovery Of Nickel From Low-Grade Nickel Laterite, Eni Febriana, Muhamad Irham Mulyadi, Wahyu Mayangsari, Januar Irawan, Iwan Setiawan, Ahmad Maksum, Florentinus Firdiyono, Soesaptri Oediyani, Agus Budi Prasetyo, Johny W. Soedarsono

Journal of Sustainable Mining

This study highlights the effectiveness of employing double-acting liberation to release Ni and Co from the complex phases of the low-grade nickel laterite. It includes the addition of concentrated sulphuric acid and NaF as well as the heat treatment prior to roasting and leaching processes to improve the destruction of the complex phases contained. The finding describes that dehydration of iron sulfate and decomposition of the lizardite at a lower temperature, 270°C, were occurred in the pre-treatment process, followed by hematite formation in the roasting process. It subsequently accelerated Ni and Co extraction in the pregnant solution and omitted Fe …

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Geochemical Characteristics And Influencing Factors Of Deep Coalbed Methane In The Linxing-Shenfu Block, Wu Peng, Hu Weiqiang, Li Yangbing, Ma Litao, Li Yong, Zhao Fei, Niu Yanwei, Chen Jianqi, Li Panpan, Liu Zaizhen, Li Chenchen, Cao Di, Liu Cheng May 2024

Geochemical Characteristics And Influencing Factors Of Deep Coalbed Methane In The Linxing-Shenfu Block, Wu Peng, Hu Weiqiang, Li Yangbing, Ma Litao, Li Yong, Zhao Fei, Niu Yanwei, Chen Jianqi, Li Panpan, Liu Zaizhen, Li Chenchen, Cao Di, Liu Cheng

Coal Geology & Exploration

Identifying the origin and geochemical characteristics of deep coalbed methane (CBM) is critical for its exploration and production. This study examined the desorbed gas from deep-CBM parameter wells in the Linxing-Shenfu block on the eastern margin of the Ordos Basin. It systematically tested the composition, content, and carbon isotopes of CBM in coal seams Nos. 8 and 9. In combination with the degree of thermal evolution, gas-bearing properties, coal seam burial depths, geological structures, and hydrogeologic conditions, it delved into the geochemical characteristics and influencing factors of deep CBM. The results show that the deep CBM in the study area …

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A Simulation Study Of Mechanisms Behind Water Inrush From Fault-Bearing Floors Of Ultra-Thick Coal Seams Under Loading And Unloading At Significantly Variable Amplitude, Li Hao, Zhu Kaipeng, Guo Guoqiang, Zhou Yang, Kang Zhiqin May 2024

A Simulation Study Of Mechanisms Behind Water Inrush From Fault-Bearing Floors Of Ultra-Thick Coal Seams Under Loading And Unloading At Significantly Variable Amplitude, Li Hao, Zhu Kaipeng, Guo Guoqiang, Zhou Yang, Kang Zhiqin

Coal Geology & Exploration

Ultra-thick coal seams feature large stope spaces and extensive disturbance ranges. Significantly variable amplitude loading and unloading are prone to cause the fault rupture of floors of ultra-thick coal seams, inducing water disasters. Numerical simulation serves as a critical method for revealing the fault reactivation and water inrush mechanisms at the floors of ultra-thick coal seams. The key of this method is to accurately inflect the coupling characteristics of rock mass rupture and fissure water under significantly variable amplitude loading and unloading. This study determined the correlations of the damage variable with plastic strain and stress, deriving the equations for …

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Weight And Resistance Reduction Mechanism Of Drilling Rods For Drilling In Soft Coal Seam And Its Application, Wang Yonglong, Guo Jiakuan, Yu Zaijiang, Du Kang, Sun Yuning May 2024

Weight And Resistance Reduction Mechanism Of Drilling Rods For Drilling In Soft Coal Seam And Its Application, Wang Yonglong, Guo Jiakuan, Yu Zaijiang, Du Kang, Sun Yuning

Coal Geology & Exploration

Gas drainage boreholes during construction is a necessary means to control gas hazards. In response to the issues such as high drilling resistance, low drilling efficiency, and high labor intensity caused by the significant self-weight of the drilling rod in drilling into the soft coal seams, a research approach of reducing the self-weight and lowering the drilling resistance by optimizing the drilling rod structure was proposed. Thus, a four-winged concave grooved drilling rod was designed to address both of its advancing resistance and rotating torque losses. Meanwhile, a drilling resistance model for the drilling rod was established. On this basis, …

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Botdr-Based Horizontal Deformation Monitoring Of Section Coal Pillars, Chai Jing, Hao Hongru, Yang Jianfeng, Gao Dengyan, Gao Kuiying, Chen Jianhua, Yang Lei, Liu Zeyu May 2024

Botdr-Based Horizontal Deformation Monitoring Of Section Coal Pillars, Chai Jing, Hao Hongru, Yang Jianfeng, Gao Dengyan, Gao Kuiying, Chen Jianhua, Yang Lei, Liu Zeyu

Coal Geology & Exploration

To address potential safety hazards like microcrack initiation, deformation, and failure inside coal pillars, this study monitored the horizontal deformations of coal pillars using the Brillouin optical time-domain reflectometry (BOTDR)—a distributed optical fiber sensing technology. Firstly, this study established a method for converting the axial strain of optical fibers into horizontal deformations based on a theoretical analysis of the failure and bulking characteristics of coal pillars. Secondly, it determined the axial tensile response of metal-based cord-shaped sensing optical fibers by conducting laboratory tests. Then, it corrected the strain coefficient based on the deformation and failure patterns of coal pillars. Finally, …

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Construction And Analysis Of A Method For Grading Long-Term Vegetation Carbon Sink In Waste Dumps Of An Open-Pit Coal Mine, Yang Fei, Cui Kuankuan, Zhang Chengye, Li Jun, Wang Jinyang, Du Tianmeng, Zhang Haoran May 2024

Construction And Analysis Of A Method For Grading Long-Term Vegetation Carbon Sink In Waste Dumps Of An Open-Pit Coal Mine, Yang Fei, Cui Kuankuan, Zhang Chengye, Li Jun, Wang Jinyang, Du Tianmeng, Zhang Haoran

Coal Geology & Exploration

Vegetation carbon sink serves as a crucial indicator for the ecological assessment of an open-pit coal mine. The accurate inversion and grading of vegetation carbon sink play a significant role in exploring the ecological restoration of coal mines. This study proposed a method for grading vegetation carbon sink of an open-pit coal mine based on the particle swarm optimization (PSO) algorithm. Specifically, using a light use efficiency (LUE) model, this study first determined the spatio-temporal distributions of the 2005‒2020 vegetation carbon sink in the waste dumps of the Shengli No.1 open-pit coal mine through inversion based on Landsat images and …

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Table Of Contents, The Editors May 2024

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.

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A Preliminary Study Of Coalbed Methane Adsorption At Fractal Interfaces, Jin Yi, Li Yani, Song Huibo, Zhao Mengyu, Yang Yunhang, Chen Zenan May 2024

A Preliminary Study Of Coalbed Methane Adsorption At Fractal Interfaces, Jin Yi, Li Yani, Song Huibo, Zhao Mengyu, Yang Yunhang, Chen Zenan

Coal Geology & Exploration

The adsorption and desorption mechanisms of coalbed methane (CBM) are foundational for revealing CBM accumulation mechanisms and achieving efficient CBM exploitation. Studies have indicated that coal reservoirs exhibit complex pore structures with fractal features, significantly influencing CBM adsorption at pore-solid interfaces. Based on a comparative analysis of several common adsorption models for gas-solid interfaces and a summary of their characteristics and applicable conditions, this study suggests that all these adsorption models still rely on the stationary assumption of adsorption selectivity for the description and application of CBM adsorption behavior at fractal interfaces while overlooking the scale invariance of the adsorption …

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Carbon Microspheres In Natural Coke: Optical Microscopic Characteristics And Their Origin And Implications, An Yanfei, Chen Kaixin, Wang Yaqiao, Cheng Shuo, Huang Jian, He Shuyang, Wang Shengjian May 2024

Carbon Microspheres In Natural Coke: Optical Microscopic Characteristics And Their Origin And Implications, An Yanfei, Chen Kaixin, Wang Yaqiao, Cheng Shuo, Huang Jian, He Shuyang, Wang Shengjian

Coal Geology & Exploration

Carbon microspheres (CMs) in natural coke are formed when coal seams undergo magma-induced rapid thermal metamorphism. Analyzing the origin of the optical microscopic characteristics of CMs assists in gaining deep insights into the rapid thermal carbonization and metamorphism of coals. This study examined the natural coke samples rich in CMs from Shitai Coal Mine in Huaibei, Anhui Province. Using experiments like high-resolution reflected polarized light microscopy and scanning electron microscopy (SEM), this study characterized the particle sizes, distribution, optical microscopic characteristics, and ultramicrofabrics of CMs in natural coke, revealing the origin and thermal evolution implications of their optical anisotropy. The …

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Evolutionary Mechanisms And Models Of Strain, Porosity, And Permeability Of Compacted Broken Coals, Li Lei, Lu Shouqing, Chu Tingxiang, Zhong Xiaoxing, Liu Chongyang, Ren Ting May 2024

Evolutionary Mechanisms And Models Of Strain, Porosity, And Permeability Of Compacted Broken Coals, Li Lei, Lu Shouqing, Chu Tingxiang, Zhong Xiaoxing, Liu Chongyang, Ren Ting

Coal Geology & Exploration

Residual coal areas in caving zones of goaves in coal mines serve as primary sites for low-temperature reactions between coal and oxygen. Hence, exploring the evolutionary models of the strain, porosity, and permeability of coals in these areas holds great significance for gaining a deep understanding of the spontaneous combustion process and regularity of coals. Based on the self-developed experimental device for gas seepage in compacted broken coals, this study explored the evolutionary patterns of the strain, porosity, and permeability of compacted coals with single/mixed particle sizes during gas seepage. Furthermore, this study analyzed the variations in the strain, porosity, …

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Intelligent Identification Method Of Drilling Fluid Rheological Parameters Based On Machine Learning, Liu Changye, Yang Xianyu, Cai Jihua, Wang Ren, Wang Jianlong, Dai Fanfei, Guo Wanyang, Jiang Guoshe, Feng Yang May 2024

Intelligent Identification Method Of Drilling Fluid Rheological Parameters Based On Machine Learning, Liu Changye, Yang Xianyu, Cai Jihua, Wang Ren, Wang Jianlong, Dai Fanfei, Guo Wanyang, Jiang Guoshe, Feng Yang

Coal Geology & Exploration

The rheology of drilling fluid, which characterizes its flow and deformation, is vital for transporting and suspending rock cuttings as well as for enhancing the drilling rate. Precise control of drilling fluid rheological parameters is essential to ensure borehole cleanliness and efficient drilling. This paper proposes an intelligent identification method for drilling fluid rheological parameters based on Convolutional Neural Networks (CNNs). The method employs magnetic stirring to generate stable images of drilling fluid flow, uses various data augmentation methods to increase the number of images and create a database, thereby enhancing the model’s robustness and generalization capabilities. The AlexNet CNN …

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Dynamic Simulations And Applicability Evaluation Of Novel Perforation Techniques, Bi Gang, Yuan Peijie, Han Fei, Fu Shuaishuai, Wu Jiemin, Ma Ying May 2024

Dynamic Simulations And Applicability Evaluation Of Novel Perforation Techniques, Bi Gang, Yuan Peijie, Han Fei, Fu Shuaishuai, Wu Jiemin, Ma Ying

Coal Geology & Exploration

The development and improvement of perforated completion techniques hold great practical significance and value for efficient testing and exploitation of oil and gas fields. However, conventional shaped-charge perforation for well completion of low-permeability reservoirs (e.g., low-permeability coal seams) suffered high seepage resistance and reduced productivity due to the presence of compaction damage zones. To achieve enhanced exploitation efficiency of low-permeability reservoirs, novel perforation techniques, including self-cleaning and after-effect perforation, have been proposed. However, their perforation performance and applicability remain ambiguous. Based on the explicit time integration algorithm and fluid-structure interaction mechanism of LS-DYNA, this study proposed a method for finite …

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Water Inrush Mechanism And Water-Conducting Fractured Zone’ Developmental Patterns Of A Typical Ultra-Thick Coal Seam In The Huanglong Coalfield During Fully Mechanized Mining, Yan Heping, Li Wenping, Duan Zhonghui, Yang Yugui May 2024

Water Inrush Mechanism And Water-Conducting Fractured Zone’ Developmental Patterns Of A Typical Ultra-Thick Coal Seam In The Huanglong Coalfield During Fully Mechanized Mining, Yan Heping, Li Wenping, Duan Zhonghui, Yang Yugui

Coal Geology & Exploration

The mining of thick coal seams in the Huanglong Jurassic coalfield has led to the formation of high water-conducting fractured zones, which are prone to connect the extremely thick sandstone aquifers of the overlying Cretaceous Luohe Formation. Qinggangping Coal Mine in the coalfield exhibits the typical characteristics of pulsed water inrushes during coal mining, posing a severe threat to safe mining. This study investigated the fully mechanized mining face 42105 in Qinggangping Coal Mine. Using 3DEC discrete element simulation, flushing fluid leakage in boreholes, integrated geophysical exploration, and borehole TV, this study examined the developmental patterns of the water-conducting fractured …

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Dynamic Mechanisms Of Coal And Gas Outbursts Based On A Multi-Zone Combined Coal Model, Li Feng, Wang Chenchen, Wang Bo, Jing Yadong, Yan Zhengxu, Zhang Minbo May 2024

Dynamic Mechanisms Of Coal And Gas Outbursts Based On A Multi-Zone Combined Coal Model, Li Feng, Wang Chenchen, Wang Bo, Jing Yadong, Yan Zhengxu, Zhang Minbo

Coal Geology & Exploration

Coal and gas outbursts (hereafter referred to as outbursts) severely affect coal mining safety. However, many scientific problems underlying the outbursts remain unsolved. To minimize the influence of anisotropy in the mechanical properties of coals on research into outbursts, this study constructed a multi-zone combined coal model. Based on the stress distribution of overlying strata and the stress wave propagation mechanisms, this study located the weak zone of coals, shrinking the research object from the outburst center to the weak zone. Given that outbursts are triggered by the disturbance of external dynamic load, this study examined the propagation patterns of …

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Anti-Channeling Methods For Coalbed Methane Production Using L-Type Horizontal Wells, Liu Zhan, Zhang Qunxia, Geng Yuxin, Luo Dan, Wang Minggang May 2024

Anti-Channeling Methods For Coalbed Methane Production Using L-Type Horizontal Wells, Liu Zhan, Zhang Qunxia, Geng Yuxin, Luo Dan, Wang Minggang

Coal Geology & Exploration

Coalbed methane (CBM) production using L-type horizontal wells can yield stable single-well production of up to above 8 000 m3/d. However, due to the lack of sand settling pockets, L-type horizontal wells fail to achieve gas-water separation under the action of gravity. Consequently, gas channeling from tubing is prone to occur, significantly decreasing pumping efficiency and restricting further drainage and pressure reduction. By optimizing the lifting process for production in the early stage, the gas channeling from tubing has been somewhat alleviated. However, the anti-channeling effects remain unsatisfactory in low-fluid-pressure and high-yield gas wells. This study examined L-type …

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Technologies For Water Hazard Prevention And Control In Burnt Rock Aquifers Within Concealed Burnt Areas, Wang Hai May 2024

Technologies For Water Hazard Prevention And Control In Burnt Rock Aquifers Within Concealed Burnt Areas, Wang Hai

Coal Geology & Exploration

Burnt rocks are extensively distributed in northwestern China, featuring well-developed pores and fractures and abundant water, emerging as primary aquifers in this region. The burnt rocks in concealed burnt areas in this region show inconspicuous surface remains, complicating their identification. Penetrating burnt rock aquifers in coal mining will lead to water hazard and destroy water resources in these aquifers. To prevent and control water hazard in burnt rocks within concealed burnt areas and preserve water resources in burnt rock aquifers, this study analyzed the distributions of burnt rocks in China and the effects of water in them on coal mining. …

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