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Insights From Automated Mineralogic Analysis Of Modern Sand, Quinten Jones
Insights From Automated Mineralogic Analysis Of Modern Sand, Quinten Jones
Graduate Theses and Dissertations
Methods for determining and categorizing the modal compositions of sand and sandstone have long been a subject of debate in the field of sedimentary geology. Point counting is the most commonly used technique for determining modal compositions from petrographic slides, which are then categorized based on relative proportions of quartz, feldspar, and rock (or lithic) fragments. However, this approach fails to adequately preserve relevant textural data, such as grain size and sorting, which play an important role in diagenesis and in influencing reservoir quality. Additionally, the categorical nature of point counting results in a lack of specificity and loss of …
Leveraging Machine Learning Models For Enhanced Landslide Prediction In Western North Carolina, Andrew Edmonds
Leveraging Machine Learning Models For Enhanced Landslide Prediction In Western North Carolina, Andrew Edmonds
Graduate Theses and Dissertations
Landslides pose significant hazards to human safety, infrastructure, and the environment, particularly in regions of high elevation that experience extended periods of heavy rainfall. This research focuses on preparing and evaluating landslide susceptibility maps (LSMs) for the Blue Ridge Mountains, a portion of the Appalachian Mountains in western North Carolina, utilizing three machine learning algorithms: Logistic Regression, Random Forest, and Gradient Boosting Regression. Sixteen landslide conditioning factors, reflecting topographic, geological, environmental, and anthropogenic influences, were identified for model input. The landslide inventory database, comprising 7,350 locations, was randomly divided into training (80%) and testing (20%) sets. The performance of each …
Optimized Filtrations For Stormwater Quality Improvement By Porous Media–Biochar Applications: Column Experiments And Inverse Modeling, Sumiaya Amin Preota, Chu-Lin Cheng, Myung Hwangbo, Jongsun Kim
Optimized Filtrations For Stormwater Quality Improvement By Porous Media–Biochar Applications: Column Experiments And Inverse Modeling, Sumiaya Amin Preota, Chu-Lin Cheng, Myung Hwangbo, Jongsun Kim
School of Earth, Environmental, & Marine Sciences Faculty Publications
Stormwater reuse plays a critical role under changing climates and increasing water demands. This study investigates the removal efficacy of lead (Pb2+) and ammonia (NH3) using sand and rice husk (RH) biochar for potential stormwater quality improvements and treatments. Column experiments combined with HYDRUS inverse modeling were conducted to optimize adsorption isotherms from breakthrough curves. Among linear and non-linear models, the Langmuir and Freundlich models performed better for sand and biochar, respectively. RH biochar showed much higher adsorption capacity of both Pb2+ (4.813 mg/g) and NH3 (6.188 mg/g). In contrast, sand showed a relatively limited adsorption capacity for Pb2+ (0.118 …
Older Groundwater Reservoirs In Nebraska, Marvin P. Carlson, Steven S. Sibray
Older Groundwater Reservoirs In Nebraska, Marvin P. Carlson, Steven S. Sibray
Conservation and Survey Division: Faculty and Staff Publications
Sedimentary rocks below Nebraska's regional water table are saturated down to the crystalline igneous and metamorphic rocks of Precambrian age. The total thickness of these sedimentary rocks ranges from about 600 feet to over 10,000 feet. Nearly all current wells in Nebraska produce water from the near-surface, unconsolidated or partly consolidated rocks. Most studies to date -- interpretive reports, test drilling, inventory of wells, monitoring water levels, and water quality determinations -- have concentrated on these near-surface sources of groundwater.
Integrated Coastal Science And Dune Management: A South Carolina Perspective, Michelle Harris
Integrated Coastal Science And Dune Management: A South Carolina Perspective, Michelle Harris
Theses and Dissertations
Historically, coastal dunes have been poorly understood from a societal perspective despite their protective role in attenuating incoming waves to reduce onshore flood risk. As developed coastlines promote strategies to design and maintain managed dune systems, it is necessary to ensure these strategies are optimized for dune health and resilience, particularly given the increasing threat of natural and anthropogenic stressors. This dissertation work aims to identify strategies that influence coastal dune management in South Carolina (SC), USA from an integrated approach, including a current use assessment, a mesoscale field-based study on strategy efficacy, and by incorporating a societal assessment and …
Extracting Metamorphic Histories Utilizing U-Pb Laser Ablation Zircon Geochronology From The Southern Appalachians Crystalline Rocks And Detrital Sediment, Meredith Kay Love Gawai
Extracting Metamorphic Histories Utilizing U-Pb Laser Ablation Zircon Geochronology From The Southern Appalachians Crystalline Rocks And Detrital Sediment, Meredith Kay Love Gawai
Theses and Dissertations
The southern Appalachian mountain belt is an accretionary orogen that formed in the southeastern United States through several phases of oceanic subduction and continental collision during the Paleozoic Era and culminated in the formation of the supercontinent Pangaea. Although many U-Pb zircon ages have been collected from the igneous, metaigneous and metasedimentary rocks in the crystalline core of the southern Appalachians, there remain opportunities to better reconstruct the metamorphic and magmatic history of the southern Appalachians through the lens of zircon geochronology. Such data are valuable in identifying genetic relationships between candidate terranes of the orogen. Herein, I present laser-ablation …
Method For Low-Cost In Situ Measurement Of Dissolved Total Volatile Organic Compound Concentrations In Surface Waters, Teagan A. Jones
Method For Low-Cost In Situ Measurement Of Dissolved Total Volatile Organic Compound Concentrations In Surface Waters, Teagan A. Jones
ATU Scholars Symposium
Increases in volatile organic compounds (VOC) in developing areas poses risks to aquatic health. Water quality changes in surface waters, if measured, are often only for field parameters of pH, specific conductance, water temperature, and major ions, e.g. Ca2+, Mg2+, Na, Cl. Elevated VOC concentrations can negatively impact aquatic ecosystems even at low concentrations, but do not cause changes in commonly measured parameters and may go undetected based on monitoring these common parameters. Traditional sampling and benchtop analysis for VOC can be both time and cost prohibitive. Here we demonstrate the use of a low-cost in situ dissolved total VOC …
The Effects Of Climate Change On The Advancement Of West Nile Virus, Mackenzie R. Epperson
The Effects Of Climate Change On The Advancement Of West Nile Virus, Mackenzie R. Epperson
ATU Scholars Symposium
The West Nile virus (WNV) first emerged in the United States in the year 1999 within the state of New York and has become endemic throughout the country over time. This virus is contracted from an avian species acting as the reservoir host, by the vector species which are mosquitoes. From this point, the mosquitoes transmit the virus to humans and other mammals, which are the dead end hosts. The WNV often presents itself as flu-like symptoms, but in serious cases can cause severe arboviral neurological disease. Since this is an arbovirus, it is important to have the ability to …
From The Ground Up: Community-Based Participatory Research Reclaiming The Science Of Lead, Juan Manuel Rubio, Bavisha Kaylan, Anthony Diaz, Patricia Flores, Maya Cheav, David C. Bañuelas, Ashley Green, Annika Hjelmstad, Ariane Jong-Levinger, Tim Schütz, Maya Carrasquillo, Alana M. W. Lebron, Jun Wu
From The Ground Up: Community-Based Participatory Research Reclaiming The Science Of Lead, Juan Manuel Rubio, Bavisha Kaylan, Anthony Diaz, Patricia Flores, Maya Cheav, David C. Bañuelas, Ashley Green, Annika Hjelmstad, Ariane Jong-Levinger, Tim Schütz, Maya Carrasquillo, Alana M. W. Lebron, Jun Wu
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
For decades, the dominant approach to lead poisoning has been to focus on homes affected by lead paint and to treat children who are already suffering from lead poisoning. This individualizing approach developed in the context of the defunding and deregulation of government agencies in the 1980s. In recent years, however, community–academic partnerships have reframed lead as an environmental issue produced by the development of the lead industry in the twentieth century and connected to overlapping histories of exploitation, discrimination, and inaction. These community-based projects have contributed to shifting research agendas (by emphasizing historical analysis and the study of the …
The Geologic History Of The Chehalis Forearc Basin, Washington State, Usa, Rud Lamb Moe
The Geologic History Of The Chehalis Forearc Basin, Washington State, Usa, Rud Lamb Moe
Dissertations and Theses
The Chehalis Basin, in southwest Washington, is one of a series of forearc basins between the Cascade Arc and the Coast Range in the Pacific Northwest. While the Seattle basin to the north, and the Portland-Tualatin basins to the south are both relatively well studied, the geologic evolution of basins in between is poorly constrained. The Chehalis basin is underlain by accreted Eocene oceanic basalt of the Crescent Formation. The basin fill consists of sedimentary rocks and volcanic rocks deposited throughout the Cenozoic. It has undergone N-S shortening driven by transpressional stress from oblique subduction of the Juan de Fuca …
Quantifying The Rates Of Coastal Change Along Smith Island, Maryland, Sarah Lacy, Ravi Sankar
Quantifying The Rates Of Coastal Change Along Smith Island, Maryland, Sarah Lacy, Ravi Sankar
Longwood Senior Thesis Proposal
As increased climate variability continues to alter the environment, coastal landscapes are becoming increasingly vulnerable to geomorphic change. Coastal erosion, driven by rising sea levels, land subsidence, more intense storm events and human-induced activities poses a serious threat to the sustainability and resilience of island environments like Smith Island, a small marsh island located in the Chesapeake Bay. This study investigates the impacts of recent shoreline change along selected alongshore segments of the island’s coast. Using a combination of aerial imagery, field surveying techniques, and novel geospatial analyses, the project aims to identify areas at highest risk of erosion and …
Estimated Amounts Of Terrestrial Carbon Mobilized And Sequestered By The 1980 Mount St. Helens Eruption, Washington State, Usa, Lizzet G. Reyes
Estimated Amounts Of Terrestrial Carbon Mobilized And Sequestered By The 1980 Mount St. Helens Eruption, Washington State, Usa, Lizzet G. Reyes
Dissertations and Theses
Volcanic eruptions significantly influence the geologic carbon cycle by emitting CO2 and mobilizing terrestrial carbon pools. The 1980 Mount St. Helens (MSH) eruption offers a unique case study, triggering a massive landslide that displaced 2.7 km3 of sediment, buried 600 km2 of forest, and disrupted regional carbon dynamics. Pre-eruption terrestrial carbon stocks, including aboveground biomass (AGB), dead biomass (D), and soil organic carbon (S), averaged 209.5 tC/ha. Post-eruption, total carbon density fell to 118.7 tC/ha, driven mainly by a 51% reduction in AGB, modest declines in D, and redistribution of S. Over 36 years, ecosystem recovery increased …
Table Of Contents, The Editors
Research On Underground Coal Gasification From 2023 To 2024: A Systematic Review, Qin Yong, Yi Tongsheng, Wang Lingxia
Research On Underground Coal Gasification From 2023 To 2024: A Systematic Review, Qin Yong, Yi Tongsheng, Wang Lingxia
Coal Geology & Exploration
Background The industrialization of underground coal gasification (UCG) technology presents a potential solution for securing the supply of clean energy. The latest wave of exploration into UCG is currently gaining momentum. Methods This review systematically organizes domestic and international literature, expatiates the advances in research on UCG from 2023 to 2024, analyzes the primary challenges in its development, and proposes key areas for future exploration. Advances Transformative technological advancements in the development and utilization of coal energy based on UCG have been proposed. The development of an integrated, synergistic UCG – coalbed methane – carbon capture, utilization, and storage (UCG–CBM–CCUS) …
Evolutionary Pattern And A Calculation Method Of In Situ Gas Pressure Based On Pressure-Retaining Coal Cores, Gao Mingzhong, Song Jie, Cui Pengfei, Li Yongcheng, Wang Zhipeng, Zhou Xuemin, Li Ju, Hao Zongxin, Hao Haichun
Evolutionary Pattern And A Calculation Method Of In Situ Gas Pressure Based On Pressure-Retaining Coal Cores, Gao Mingzhong, Song Jie, Cui Pengfei, Li Yongcheng, Wang Zhipeng, Zhou Xuemin, Li Ju, Hao Zongxin, Hao Haichun
Coal Geology & Exploration
Objective and Methods The in situ gas pressure of coal seams represents a crucial parameter for the safe production of coal mines and the assessment of coalbed methane (CBM) resources. To overcome current limitations in determining the in situ gas pressure, such as prolonged measurement cycles and the influence of multiple parameters on the measurement results, this study conducted isothermal adsorption and volumetric expansion desorption experiments on pressure-retaining coal cores with varying moisture contents using a self-constructed experimental system for gas pressure evolution in pressure-retaining coal cores. As a result, the evolutionary pattern of gas pressure in pressure-retaining coal cores …
Key Technologies For Surface Control Of Gas Dynamic Disasters In Coal Mines And Their Application, Wang Bo, Xu Fengyin, Liu Wenge, Shao Sihua, Wang Ning, Wen Jiandong, Cheng Guoxi, Qu Zhenghui, Xie Yadong, Han Jiaye, Li Zhi, Xu Bo, Yang Weihua, Zhang Yiteng, Li Changxing
Key Technologies For Surface Control Of Gas Dynamic Disasters In Coal Mines And Their Application, Wang Bo, Xu Fengyin, Liu Wenge, Shao Sihua, Wang Ning, Wen Jiandong, Cheng Guoxi, Qu Zhenghui, Xie Yadong, Han Jiaye, Li Zhi, Xu Bo, Yang Weihua, Zhang Yiteng, Li Changxing
Coal Geology & Exploration
Objective and Significance As the coal mining depth increases, coal mining faces increasingly prominent challenges including coal and gas outbursts, rock bursts, and compound dynamic disasters. Deepening the understanding of disaster-causing mechanisms and developing diversified prevention and control technologies are significant for the safe production of coal mines. Employing the key technologies for coalbed methane (CBM) production to control gas-related dynamic disasters is an inevitable course for the safe production of coal mines. However, large-scale, suitable technology systems are yet to be developed. Methods From the perspective of the application of key technologies for surface CBM production, this study systematically …
Microseismic Monitoring And Assessment Of Segmented Hydraulic Fracturing Of Horizontal Wells In Coal Seam Roofs, Li Quangui, Peng Shuyue, Liang Yunpei, Li Wenxi, Qian Yanan, Cheng Chunhui, Yu Changjun, Zhan Jinfei
Microseismic Monitoring And Assessment Of Segmented Hydraulic Fracturing Of Horizontal Wells In Coal Seam Roofs, Li Quangui, Peng Shuyue, Liang Yunpei, Li Wenxi, Qian Yanan, Cheng Chunhui, Yu Changjun, Zhan Jinfei
Coal Geology & Exploration
Background Microseismic monitoring, a non-destructive monitoring technique, has been extensively applied in the hydraulic fracturing performance assessment of coal seams. However, little attention is paid to the vertical wave velocity gradients in media in the same layer during the construction of layered wave velocity models. This leads to limited precision of travel time calculation and microseismic source localization, thus affecting the assessment accuracy of the hydraulic fracturing of coal seams. Objective and Methods Based on the coal seam segmented hydraulic fracturing project in a mine in Anhui, this study proposes an improved velocity model based on the Universal Kriging interpolation …
Reflections And Implementation Strategies For Constructing A Standard System For Deep Coalbed Methane Exploration And Exploitation, Chen Xinjun, Liu Zengqin, Shen Baojian, Zhao Shihu, Zhang Jiaqi, Ye Jincheng
Reflections And Implementation Strategies For Constructing A Standard System For Deep Coalbed Methane Exploration And Exploitation, Chen Xinjun, Liu Zengqin, Shen Baojian, Zhao Shihu, Zhang Jiaqi, Ye Jincheng
Coal Geology & Exploration
Objective Deep coalbed methane (CBM; burial depths: > 1500 m) in China holds considerable resource potential. As a strategic clean energy, deep CBM is exhibiting increasingly high value of exploitation and utilization. This is of great practical significance for China’s energy structure transformation and the achievement of peak carbon dioxide emissions and carbon neutrality in the country. In recent years, breakthroughs have been made in deep CBM exploration in basins such as Ordos, Sichuan, and Junggar, with a single-well daily gas production exceeding 100 000 m3, marking the initial achievement of large-scale deep CBM exploitation. However, the existing standard …
Dynamic Gas Supply Mechanism And Theoretical Production Modes Of Free Gas-Rich Deep Coal Reservoirs, Chen Shida, Zhang Taiyuan, Tang Dazhen, Xu Hao, Tao Shu, Li Song, Tang Shuling
Dynamic Gas Supply Mechanism And Theoretical Production Modes Of Free Gas-Rich Deep Coal Reservoirs, Chen Shida, Zhang Taiyuan, Tang Dazhen, Xu Hao, Tao Shu, Li Song, Tang Shuling
Coal Geology & Exploration
Objective and Methods The production processes of adsorbed and free gases and the dynamic partitioning mechanism behind the production efficiency of both gas types are critical scientific issues to be addressed urgently in the exploration and production of deep coalbed methane (CBM). Based on the test and assay data of cores from exploration wells, this study systematically analyzed the theoretical production of deep CBM resources. By integrating the building of mathematical and numerical models, carbon isotope monitoring of methane, and the analysis of production curves, this study revealed the spatiotemporal evolutionary processes of production-induced pressure drop expansion, adsorbed gas desorption, …
An Experimental Study Of Ch4 Displacement By Co2 Under Varying Initial Reservoir Pressures, Xu Jiang, Jiang Shiyu, Peng Shoujian, Wang Zhonghui, Chen Jiaxuan, Niu Huiting
An Experimental Study Of Ch4 Displacement By Co2 Under Varying Initial Reservoir Pressures, Xu Jiang, Jiang Shiyu, Peng Shoujian, Wang Zhonghui, Chen Jiaxuan, Niu Huiting
Coal Geology & Exploration
Objective This study aims to reveal the evolutionary patterns of reservoir parameters during the CO2-enhanced coalbed methane (CO2-ECBM) recovery and the impact of initial reservoir pressure on CBM recovery by gas injection. Methods Based on the multi-field coupling-based physical simulation experiment system of gas injection into coal seams for production growth, this study conducted experiments of CH4 displacement by CO2 under a constant gas injection pressure of 2.0 MPa and initial reservoir pressures of 1.5 MPa, 1.0 MPa, and 0.5 MPa. Accordingly, this study explored the spatiotemporal evolutionary patterns of multiphysical field parameters such …
Parameter Optimization For Multistage Horizontal Well Fracturing Based On Multi-Cluster Perforation For Deep Coal Measure Gas: A Case Study Of The Jurassic Baijiahai Area In The Junggar Basin, Wang Bo, Jin Chenghong, Liu Jiang, Wang Zhiwei, Li Shenjian, Sheng Mao
Parameter Optimization For Multistage Horizontal Well Fracturing Based On Multi-Cluster Perforation For Deep Coal Measure Gas: A Case Study Of The Jurassic Baijiahai Area In The Junggar Basin, Wang Bo, Jin Chenghong, Liu Jiang, Wang Zhiwei, Li Shenjian, Sheng Mao
Coal Geology & Exploration
Objective The multistage horizontal well fracturing based on multi-cluster perforation has emerged as an effective approach for the efficient production of deep coal-measure gas (CMG). However, deep coals feature unique rock mechanical properties, fluid loss characteristics of reservoirs, and microfracture developmental characteristics, which differ significantly from those of unconventional shales, tight sandstones, and shallow coals. As a result, existing fracturing experience cannot be directly applied, highlighting the investigation of fracturing parameter optimization tailored for deep CMG production.Methods Focusing on deep CMG reservoirs in the Baijiahai area within the Junggar Basin, this study constructed a model of multistage horizontal well …
Measures And Effects Of Eco-Geological Restoration In Well No.4 In The Muli Mining Area, Qinghai Province, China, Zhao Xin, Wang Tong, Wang Weichao, Li Congcong, Li Fei, Jiang Zhikun, Li Jin
Measures And Effects Of Eco-Geological Restoration In Well No.4 In The Muli Mining Area, Qinghai Province, China, Zhao Xin, Wang Tong, Wang Weichao, Li Congcong, Li Fei, Jiang Zhikun, Li Jin
Coal Geology & Exploration
Objective The Muli mining area, located in the hinterland of the Qilian Mountains, Qinghai Province, serves as the source of the Datong River—a major tributary of the Yellow River. This area falls within the alpine permafrost region, exhibiting a sensitive, fragile ecosystem. In the early 21st century, disordered coal mining in this area has caused ecological damage. This has notably posed four challenges in the ecological restoration of well No.4 in this area: (1) high, steep, and unstable slopes of spoil heaps; (2) a large volume of water accumulating in mining pits; (3) permafrost excavation and destruction, and (4) land …
Advances In Research On Lithium In Coal-Bearing Strata And Its Isotopes, Zhang Yun, Wei Yingchun, Cao Daiyong, Li Xin, Jin Liangliang, Dong Bo, Wang Xin
Advances In Research On Lithium In Coal-Bearing Strata And Its Isotopes, Zhang Yun, Wei Yingchun, Cao Daiyong, Li Xin, Jin Liangliang, Dong Bo, Wang Xin
Coal Geology & Exploration
Significance Lithium serves as a significant strategic metal in emerging industries, and lithium isotopes have become crucial geochemical tracers due to their pronounced mass-dependent fractionation effects. Therefore, lithium minerals in coal-bearing strata have emerged as a priority in recent exploration of strategic metallic mineral resources. Investigating the isotopic composition and variation of lithium in coal-bearing strata helps reveal the sources, migration, and enrichment process of lithium while also providing a theoretical basis for lithium exploration and exploitation in coal-bearing strata. Advances This study offers a summary of advances in research on lithium in coal-bearing strata and its isotopes from three …
Multi-Field Information Fusion-Based Analysis Of The Macroscopic And Mesoscopic Damage Evolution And Location Identification Of Caving And Water-Conducting Fracture Zones For Mining Overburden, Wei Jiangbo, Wang Shuangming, Liu Lang, Wei Baoning, Chong Deyu, Liu Zhizhen, Li Dongkui, Zhuang Dengdeng, Zhou Jing
Multi-Field Information Fusion-Based Analysis Of The Macroscopic And Mesoscopic Damage Evolution And Location Identification Of Caving And Water-Conducting Fracture Zones For Mining Overburden, Wei Jiangbo, Wang Shuangming, Liu Lang, Wei Baoning, Chong Deyu, Liu Zhizhen, Li Dongkui, Zhuang Dengdeng, Zhou Jing
Coal Geology & Exploration
Objective For the coal mining areas in the middle reaches of the Yellow River, there is an urgent need to determine the failure characteristics of the mining overburden and the spatial structural evolution of caving and water-conducting fracture zones in the overburden, which is recognized as the major challenge in coal mining through gangue grouting filling in goaves. Methods To accurately identify the locations of the caving and water-conducting fracture zones in the mining overburden, this study investigated mining face 42205 in the Liangshuijing Coal Mine in northern Shaanxi Province. Using drilling data, this study constructed a numerical model of …
Intelligent Identification Of The Acoustic Emission Characteristics And Crack Propagation States During Of Coal Failure Based On The Nrbo-Xgboost Model, Zhang Tianjun, Cao Xinshuang, Song Shuang, He Suinan, Xue Yilun, Liu Guoying, Chen Juntao
Intelligent Identification Of The Acoustic Emission Characteristics And Crack Propagation States During Of Coal Failure Based On The Nrbo-Xgboost Model, Zhang Tianjun, Cao Xinshuang, Song Shuang, He Suinan, Xue Yilun, Liu Guoying, Chen Juntao
Coal Geology & Exploration
Objective The dynamic hazards of coals are intimately associated with the complexity and uncertainty of coal failure, while accurately identifying the propagation states of coal cracks serves as a critical approach to investigating the instability failure of coals. However, the current identification methods based on the physical quantities of acoustic emission suffer from slow speeds and low efficiency, failing to meet the demand for safe, efficient, and intelligent mining of coal mines. Methods To achieve the intelligent identification of the crack propagation states of coals, this study constructed an optimization model based on the Newton-Raphson-based optimizer (NRBO) and the eXtreme …
Effects Of Coal Seam Dip Angle On Asymmetric Load Transfer Paths In The Overburden Of Inclined Stopes, Zhu Kaipeng, Luo Shenghu, Xie Panshi, Li Zhilin, Fan Juan, Tian Chengyang, Yi Leilei, Xu Hui
Effects Of Coal Seam Dip Angle On Asymmetric Load Transfer Paths In The Overburden Of Inclined Stopes, Zhu Kaipeng, Luo Shenghu, Xie Panshi, Li Zhilin, Fan Juan, Tian Chengyang, Yi Leilei, Xu Hui
Coal Geology & Exploration
Objectives The coal seam dip angle is recognized as the root cause of far more complex load transfer paths in the overburden of inclined stopes compared to those of common coal seams. A clear understanding of the effects of the coal seam dip angle on the load transfer paths holds great significance for the stability control of surrounding rocks in inclined coal seams. Methods Based on the engineering background of a certain coal mine in Xinjiang, this study investigated the asymmetric deformations and failure of the overburden in inclined stopes using physical similar material simulation experiments, finite element numerical simulations, …
Operation Strategy Simulation Of The Heating System For Moderately Deep Geothermal Resources, Zhao Yongzhe, Zhao Baofeng, Hu Zhenyang, Gou Li, Du Dingshan, Liu Chenglu
Operation Strategy Simulation Of The Heating System For Moderately Deep Geothermal Resources, Zhao Yongzhe, Zhao Baofeng, Hu Zhenyang, Gou Li, Du Dingshan, Liu Chenglu
Coal Geology & Exploration
Background The active utilization of moderately deep geothermal resources for heating serves as a critical measure to achieve the goals of peak carbon dioxide emissions and carbon neutrality. Meanwhile, the effectiveness of the operation strategies of the heating system using these resources directly influences heating performance and significantly affects the energy consumption of the heating system. It is necessary to prevent resource waste while utilizing geothermal energy. Methods Based on a heating project using moderately deep geothermal resources in the Guanzhong Basin, Shaanxi Province, this study established a dynamic simulation model using the TRNSYS transient simulation software. Then, this study …
Fracture Activation In The Overburden And Aquiclude Stability Under The Mining Of Close-Distance Coal Seams, Cao Jian, Su Haitao, Wang Chao, Li Jianwei, Li Liang, Mao Xuwei
Fracture Activation In The Overburden And Aquiclude Stability Under The Mining Of Close-Distance Coal Seams, Cao Jian, Su Haitao, Wang Chao, Li Jianwei, Li Liang, Mao Xuwei
Coal Geology & Exploration
Background In the Jurassic coalfield of northern Shaanxi Province, the repeated mining of close-distance coal seams exacerbates the activation of fractures in the overburden. This is prone to cause aquiclude instability, leading to groundwater loss. Methods This study aims to reveal the characteristics of fractures in the overburden and the aquiclude stability in the mining of close-distance coal seams. Using a method combining measurement statistics, physical simulations using similar materials, and theoretical analysis, this study proposed categorizing primary coal-rock combinations based on the water-preserved mining of close-distance coal seams in the Jurassic coalfield of northern Shaanxi. Additionally, this study analyzed …
Inversion Of Electric Field Component EX In The Sotem Method Based On The Improved Particle Swarm Optimization Algorithm, Zhang Jifeng, Chen Changjian, Li Yuteng, You Xiran, Ma Ziben
Inversion Of Electric Field Component EX In The Sotem Method Based On The Improved Particle Swarm Optimization Algorithm, Zhang Jifeng, Chen Changjian, Li Yuteng, You Xiran, Ma Ziben
Coal Geology & Exploration
Objective The inversion of the horizontal electric field component in the grounded-source short offset transient electromagnetic (SOTEM) method using traditional algorithms is prone to fall into local extrema. To address this challenge, this study proposed an improved particle swarm optimization (PSO) algorithm that integrates the center of gravity reverse learning strategy. Methods Based on the center of gravity reverse learning strategy, the improved PSO algorithm can dynamically adjust learning factors and the value of the adaptive inertia weight, thus improving the global search capability and convergence efficiency effectively. The performance of the improved PSO algorithm was verified using the typical …
Characteristics Of Dynamic Mode Ⅱ Fracture Of Frozen Saturated Sandstones Under Varying Low Temperatures And Loading Rates, Zhao Tao, Cui Zhao, Jia Hailiang, Yang Guangyu
Characteristics Of Dynamic Mode Ⅱ Fracture Of Frozen Saturated Sandstones Under Varying Low Temperatures And Loading Rates, Zhao Tao, Cui Zhao, Jia Hailiang, Yang Guangyu
Coal Geology & Exploration
Background Investigating the mode Ⅱ fracture of frozen saturated sandstones under dynamic disturbances, including changes in their critical stress intensity factor (SIF; i.e., fracture toughness) and energy dissipation mechanisms, is crucial for the safe excavation of frozen wellbores through drilling and blasting in coal mines. Methods Using a split Hopkinson pressure bar (SHPB), this study conducted experiments on the dynamic mode Ⅱ fracture of a sandstone specimen using the short core in compression (SCC) method (also referred to as dynamic SCC experiments) under varying temperatures and loading rates. Accordingly, this study analyzed the SIF versus time curves of the frozen …