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Mechanism And Application Of Cross-Interface Fracturing For Permeability Enhancement Through The Roof Blasting Of Tectonic Coal Seams, Gao Kui, Wang Youwei, Qiao Guodong, Tian Yu, Fu Shigui

Coal Geology & Exploration

Deep coal mining is challenging due to deteriorating geological conditions. After undergoing multiphase tectonic movements, primary coals have evolved into soft tectonic coal seams with low permeability and high gas content, complicating drilling in coal seams. In this case, the blasting-induced fractures are not well-developed and are prone to be re-compacted. So far, no fundamental breakthrough has been achieved in the key technology of fracturing for permeability enhancement technology through the roof blasting of tectonic coal seams. Given this, this study established test models for similar simulation tests and numerical analysis on the roof blasting of coal seams. By monitoring …

Research On Tar-Rich Coals: Progress And Prospects, Wang Shuangming, Bao Yuan, Hao Yonghui, Wang Shengquan, Shi Qingmin, Li Dan, Hu Yiliang

Coal Geology & Exploration

Tar-rich coals are a coal-based oil and gas resource that integrates the properties of coal, oil, and gas. Given China's energy endowment of abundant coal resources but limited oil and gas reserves, exploiting tar-rich coals plays a significant role in alleviating China's tight supply of oil and gas resources and achieving green development and low-carbon utilization of coals. Using tar-rich coals as the keyword, we searched the CNKI and Web of Science databases for academic articles and patents published from 1985 to the end of 2023. Based on the search results, we statistically analyzed the process and main aspects of …

Exploring The Pore Structure Of Reconstructed Soils And Its Effects On Water And Salt Transport Based On Ct Scanning, Li Huakun, Zheng Liugen, Chen Yongchun, Li Bing, Tao Pengfei, Li Hao

Coal Geology & Exploration

Coal gangue serves as a critical material for landfilling and reclamation in the subsidence areas of coal mines. However, due to its rough textures and poor water-holding capacity, soils reconstructed using coal gangue exhibit somewhat different pore structures and water-salt transport from undisturbed soils. To explore the changes in the pore structure of the reconstructed soils and their effects on water and salt transport, this study analyzed the differences in the pore structures between four samples from undisturbed soils, the overburden, mud-gangue mixtures, and gangue using CT scanning and image analysis. Furthermore, an indoor experimental device was designed to simulate …

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.

Response Mechanism Characteristics Of Mining-Induced Fault Activation, Sun Wenbin, Hao Jianbang, Dai Xianzheng, Kong Lingjun

Coal Geology & Exploration

In the process of coal mining, mining-induced stress perturbation is a key factor leading to fault activation, which is a primary challenge faced by safe coal mining. Fault activation is prone to induce geological disasters such as rock bursts and floor water inrushes of coal mines. Furthermore, it poses a serious threat to mining safety. Using the Flac^3D software for numerical simulations and similar material simulation experiments, this study established a model for faults’ stress-displacement responses under coal mining to analyze the mechanisms behind the evolution of fault structure zones in the process of coal mining. Key findings are …

Laws Of Changes In The Energy Of Gas Hydrate-Bearing Coals Under Different Confining Pressures And Saturations, Zhu Wei, Gao Xia, Zhang Baoyong, Wu Qiang

Coal Geology & Exploration

Gas hydration for the solidification of coal seams susceptible to outbursts is a novel technology used to prevent coal and gas outbursts by reducing gas pressure and enhancing coal strength. However, an unclear understanding of the failure characteristics and the energy dissipation law of gas hydrate-bearing coals under different confining pressures and saturations leads to the lack of a theoretical basis for the prevention of dynamic disasters such as field coal and gas outbursts in deep mines. Based on the deviatoric stress-strain curves obtained using triaxial compression tests, this study calculated and analyzed the laws of changes in energy of …

Fracture Propagation Mechanism In Directional Perforation And Hydraulic Fracturing Of Coal Seam Horizontal Wells, Pang Tao, Jiang Zaibing, Hui Jiangtao, Jia Bingyi

Coal Geology & Exploration

Horizontal well perforation and fracturing in complex coal-bearing strata are key to increasing coal seam permeability and enhancing gas extraction efficiency, with the formation structure and perforation location determining fracture propagation. Considering the characteristics of formation structure and perforation locations, a fracturing geological model is established. Based on the finite element method, a numerical model is constructed to study the effects of perforation location, formation conditions, and the difference between vertical stress and horizontal stress on fracture perforation. Engineering verification is conducted, and construction suggestions are proposed. Key findings are as follows: There are three scenarios for the perforation locations: …

An Intelligent Water Source Discrimination Method For Water Inrushes From Coal Seam Roofs In The Inner Mongolia-Shaanxi Border Region, Wang Hao, Sun Junqing, Zeng Yifan, Shang Hongbo, Wang Tiantian, Qiao Wei

Coal Geology & Exploration

Water hazard on the coal seam proof induced by high-intensity coal mining are increasingly prominent in the Inner Mongolia-Shaanxi border region. The effective, accurate water-source discrimination of the water inrushes is the key to water hazard prevention. This study investigated three typical mines in the Inner Mongolia-Shaanxi border region. To this end, principal component analysis (PCA) was employed to extract principal components from 80 groups of groundwater samples. Then, with inorganic indicators K⁺+Na⁺, Ca²⁺, Mg²⁺, Cl⁻, SO₄ ²⁻, HCO₃ ⁻ and TDS and organic indicators UV_{254 …}

Sulphate Contamination In An Abandoned Coal Mine In Light Of Mining Effects, Qi Yueming, Zhou Pei, Zhou Lai, Jiang Dan, Yang Yuqing, Liu Yanzhuo

Coal Geology & Exploration

Abandoned high-sulfur coal mines will become deeply buried acid-producing contamination sites, posing hazards to adjacent aquifers and surrounding environments. Furthermore, mining effects and the complex spatial distribution of abandoned mines complicate the assessment of the contamination processes and degrees in adjacent aquifers. Focusing on a certain abandoned coal mine, this study examined the migration characteristics of SO₄ ²⁻ pollution in acid mine drainage using numerical simulations by taking sulfate (SO₄ ²⁻) as the characteristic contaminant and considering the effects of the fractures formed by the mining of multiple coal seams on the aquifer structure. Furthermore, it analyzed …

Three-Dimensional Forward Modeling Using The Transient Electromagnetic Method Under Complex Terrains And The Analysis Of Terrain Effects, Qu Shaobo, Zhu Jiao, Jiang Zhihai, Li Maofei, He Zhilong

Coal Geology & Exploration

The ground-based transient electromagnetic method (TEM), with unique advantages, has been extensively applied for hydrogeological exploration in coal mines. However, in field exploration, complex terrains tend to cause variations in geometric shapes of transmitting sources and deviations in signals received, reducing exploration accuracy. Hence, by integrating theoretical analysis and numerical simulations with the analysis of actual terrain data, this study systematically investigated the response characteristics of electrical- and magnetic-source TEM fields under complex terrains. Using the vector finite-element electromagnetic forward modeling technique based on second-order backward Euler discretization, this study delved into the laws of influence of peak and valley …

Exploring The Detection Performance Of Different Array Configurations For Multi-Electrode Resistivity Method Tomography Using A 2.5d Finite Element Method, Zhao Rongchun, Lyu Yuzeng, Zhang Zhi, Wei Liuye, Pan Hongxu

Coal Geology & Exploration

Multi-electrode resistivity method is equipped with various electrode array configurations. Due to their different electrode arrangements, various electrode array configurations tend to exhibit significantly varying detection effects under different survey environments. Hence, to achieve satisfactory detection effects using high-resolution electrical resistivity tomography, it is necessary to explore the strategy for choosing appropriate array configurations targeting different objects in practical work. Given the high applicability of the method, its forward and inversion calculations remain a critical task. Based on the differential equations to be satisfied by the point source potential in a three-dimensional structure, this study derived the variational problem to …

Research On Path Planning Methods For Underground Roadheader Robots, Zhang Xuhui, Zheng Xili, Yang Wenjuan, Li Yuyang, Ma Bing, Dong Zheng, Chen Xin

Coal Geology & Exploration

In order to solve the problems of difficulty and low efficiency in the movement of robotic roadheaders under conditions of non-full-section roadways in coal mines, the characteristics of unstructured environments in coal mines and the motion characteristics of robotic roadheaders were analyzed, and a path planning method for robotic roadheaders based on deep reinforcement learning was proposed. The tunnel environment was constructed in real time using depth cameras, a virtual model for detecting roadheader-tunnel collisions was established, collision detection was performed in a virtual environment using the hierarchical bounding box method, and an obstacle avoidance strategy under the restrictions of …

Intelligent Identification Method For Overburden Three Zones Of A Goaf, Li Jianwen, Zhao Wen, Wu Zhenkun, Xu Xiaobing, Wang Qingtao, Duan Longchen

Coal Geology & Exploration

In this paper, an intelligent identification method was proposed to ascertain overlying strata failure types and fracture development in the overlying strata of a goaf, and identify three zones (sagging zone, fractured zone and caving zone) quickly and accurately. This method is expected to be a basis in later development of goaf treatment plans. A coal mine goaf in Shandong Province was introduced for case study, where the Bayesian Online Changepoint Detection (BOCD) algorithm was employed to analyze the changes and response characteristics of the drilling fluid loss and drilling rate over the drilling process at the boundaries of three …

Edge Detection Of Low Illumination Image In Cutting Unit Of Shearer, Jia Pengtao, Jin Luwei, Wang Bin, Guo Fengjing, Li Na

Coal Geology & Exploration

In this paper, a fractional differentiation-based edge detection algorithm named Lif is proposed to address the edge detection problems of missing edge and fuzzy details in the cutting unit of shearers working in low-light underground environments. First, the initial fractional mask operator was built using a larger detection template according to the Grünwald-Letnikov definition of the fractional derivative. Then, the weight coefficients at various positions of the mask operator were determined according to the theory of Pascal’s triangle, and the mask operator was extended to four different directions. Finally, the mask operator was convolved with the image, and the local …

Exploring Dynamic Parameters And Tooth Structure Of Self-Propelled Borehole Repairing Drill Bits, Liu Yong, Li Yang, Wei Jianping, Yuan Yongwang, Dai Shuo, Li Linyu

Coal Geology & Exploration

Self-propelled borehole repairing drill bits provide an effective technique for repairing long boreholes that have failed. In order to further improve the borehole repair speed and gas drainage efficiency, based on the theory of jet recoil, the relationship between the jet recoil force and nozzle parameters was analyzed, and a theoretical model was established for rotational mechanics of self-propelled borehole repairing drill bits. Subsequently, the coal-breaking processes of drill bits with different tooth structures were simulated using LS-DYNA, the failure modes in coal mass broken by cutting teeth and the rules of variation in the volume of coal broken by …

Experimental Impact Craters Into Sloped Targets, Ashley L. Miller, Mark Cintala, Christopher Cline

Research & Creative Achievement Day

Impact cratering is a process that shapes every planetary body in our solar system, including the Earth. On smaller planetary objects without atmospheres like the Moon and asteroids (e.g. Vesta and Ceres), impact cratering creates a rough surface with varying topography as opposed to a flat, horizontal surface. In general, impact cratering experiments are performed into flat targets to simplify the physics and model craters at larger planetary scales. However, the smallest craters that form on planetary surfaces are greatly affected by the local topography and cannot be understood by looking at experiments into flat targets. Dr. Anderson and her …

Development Of Novel Analytical Methods For The Investigation Of Mammalian Tissues And Cells, Grace A. Binder

USF Tampa Graduate Theses and Dissertations

This dissertation endeavors to advance the frontiers of analytical chemistry by addressing critical challenges across three distinct chapters. In the first chapter, the focus is on the evaluation of digestion methods for the analysis of trace metals in mammalian tissues and the Standard Reference Material NIST 1577c. The primary goal is to optimize methodologies, laying the groundwork for reliable trace metal analysis and furthering our understanding of their roles in biological systems.

Transitioning into the realm of immunomodulation, the second chapter elucidates immune response, disease and treatment through the optimization and discovery of STING modulators, utilizing the luciferase assay for …

New Vertebrate Microfossils Expand The Diversity Of The Chondrichthyan And Actinopterygian Fauna Of The Maastrichtian–Danian Hornerstown Formation In New Jersey, Zachary Boles, Paul V. Ullmann, Ian Putnam, Mariele Ford, Joseph T. Deckhut

School of Earth & Environment Departmental Research

The abundance of shark and actinopterygian fossils in the Cretaceous and Paleogene strata of the Atlantic Coastal Plain is well documented; but much remains unknown about the survivorship patterns of these major components of shallow marine faunas in the western Atlantic through the K/Pg mass extinction. To shed light on this subject, we describe an assemblage of new actinopterygian, chondrichthyan, and reptilian microfossils recently recovered from the Maastrichtian Navesink and Maastrichtian–Danian Hornerstown formations at the Jean and Ric Edelman Fossil Park at Rowan University in Mantua Township, New Jersey. The new microfossils clarify extinction patterns across the K/Pg, create temporal …

Potential Non-Carbonate Buffering In An Interdunal Wetland/Slack Along Lake Michigan, Faith Huff

23rd Annual A. Paul and Carol C. Schaap Celebration of Undergraduate Research and Creative Activity (2024)

Interdunal wetlands/slacks occur in Lake Michigan's coastal dunes where the wind scours the sand to the water table. Since May 2016 we have performed ecohydrological studies on the largest interdunal wetlands/slack, ~1.25 ha in size, lying within a deflated parabolic dune east of Lake Michigan at the Saugatuck Harbor Natural Area, Michigan. The slack’s hydrology is influenced by Lake Michigan-Huron, appearing and increasing in size and water depth with rising lake levels and decreasing in size to drying with low levels. Prior to 2014, the slack was completely dry and dominated by upland dune species due to low lake levels. …

Competitive Interactions Between Palatable And Unpalatable Grasses: Effects Of Selective Defoliations Of The Palatable Grasses, R A. Distel, A S. Moretto

IGC Proceedings (1977-2023)

Selective herbivory of the palatable species appears to be a dominant mechanisms contributing to species competitive replacement in grasslands. Selective herbivory of the palatable species allows unpalatable species to realize a competitive advantage within the community. To test this hypothesis we compare the competitive ability of the unpalatable grasses Stipa trichotoma or S. gyneriodes in the presence of nondefoliated and defoliated plants of the palatable grass S. clarazii. The three species are native to a temperate semiarid grassland of Argentina. The response variables estimated in S.trichotoma and S.gynerioides, at both plant and tiller levels, were higher (P < 0.05) in the presence of defoliated than in the presence of undefoliated plants of S.clarazii. These results support the hypothesis that selective herbivory of the palatable species confers unpalatable species a competitive advantages, contributing to species competitive replacement within the community.

Arsenic Contamination Needs Serious Attention: An Opinion And Global Scenario, Abhijnan Bhat School Of Food Science And Environmental Health, Kamna Ravi Health, Engineering & Materials Sciences (Hems) Hub, Furong Tian Nanolab Research Centre, Baljit Singh Micra Biodiagnostics Technology Gateway

Articles

Arsenic (As) contamination is a serious global concern, polluting our natural resources, including water and soil, and posing a danger to the environment and public health. Arsenic is present in the groundwater of several countries and this contaminated water is used for irrigation, drinking, and food preparation, which poses the greatest threat to public health. Nearly 106 countries are affected by groundwater arsenic contamination and an estimated 230 million individuals worldwide are exposed to its adverse health effects, including increased cancer risks, associated cardiovascular disease and diabetes, skin lesions, neurological effects, kidney damage, and foetal or cognitive development-related complications. Arsenic …

Dispersion Of Artificial Tracers In Ventilated Caves, Claudio Pastore, Eric Weber, Frédéric Doumenc, Pierre-Yves Jeannin, Marc Lütscher

International Journal of Speleology

Artificial CO₂ was used as a tracer along ventilated karst conduits to infer airflow and investigate tracer dispersion. In the karst vadose zone, cave ventilation is an efficient mode of transport for heat, gases and aerosols and thus drives the spatial distribution of airborne particles. Modelling this airborne transport requires geometrical and physical parameters of the conduit system, including the cross-sectional areas, the airflow and average air speed, as well as the longitudinal dispersion coefficient which describes the spreading of a solute. Four gauging tests were carried out in one mine (artificial conduit) and two ventilated caves (natural conduits). …

Beach Processes Controlling Erosional Hotspots And Their Influences On Beach Nourishment Performances: A Case Study Along West-Central Florida Barrier Island Beaches, Sophia Gutierrez

USF Tampa Graduate Theses and Dissertations

This study examines the long-term performance of repeated beach nourishment over an approximately 35-year period at two barrier islands, Sand Key and Treasure Island along the west-central Florida coast, USA. Five cycles of beach nourishment on Sand Key and six on Treasure Island were conducted during the study period. Three erosional hotspots were identified along a combined 14-km stretch of the nourished beach. The processes that cause the erosional hotspot were examined through numerical modeling of nearshore wave and current fields.

The most recent three nourishments since 2006 were monitored systematically by this study. Beach profiles were surveyed bimonthly to …

Quantification Of Belowground Biomass And Sediment Accretion In Mangroves Of Different Coastal Environmental Settings Of The Costa Rican Pacific Coast, Denise M. Poveda

LSU Master's Theses

The adaptation of intertidal ecosystems such as mangroves to anticipated accelerated relative sea level rise is dependent on net increase of sediment surface elevations and forest migration inland. Ecosystem models developed to simulate trajectories of ecosystem adaptations have determined that rates of soil formation are most sensitive to surface sediment (organic and inorganic) deposition and subsurface organic production by mangrove roots. Mangrove belowground biomass contributes to soil organic matter accumulation, while mangrove litter has minor contribution due to export and annual decay. In addition to belowground biomass production, inorganic sediment loading is also key contribution to soil formation and accretion. …

Estimation Of Useful-Stage Energy Returns On Investment For Fossil Fuels And Implications For Renewable Energy Systems, Emmanuel Aramendia, Paul E. Brockway, Peter G. Taylor, Jonathan B. Norman, Matthew Kuperus Heun, Zeke Marshall

University Faculty Publications and Creative Works

The net energy implications of the energy transition have so far been analysed at best at the final energy stage. Here we argue that expanding the analysis to the useful stage is crucial. We estimate fossil fuelsʼ useful-stage energy returns on investment (EROIs) over the period 1971–2020, globally and nationally, and disaggregate EROIs by end use. We find that fossil fuelsʼ useful-stage EROIs (~3.5:1) are considerably lower than at the final stage (~8.5:1), due to low final-to-useful efficiencies. Further, we estimate the final-stage EROI for which electricity-yielding renewable energy would deliver the same net useful energy as fossil fuels (EROI …

Festival Of Research Abstracts, Spring 2024, College Of Science And Mathematics, Wright State University

Festival of Research

The collection of abstracts accepted for the Spring 2024 Festival of Research hosted by the Wright State University College of Science and Mathematics.

Paradox Lost: Wide Gape In The Ordovician Brachiopod Rafinesquina Explains How Unattached Filter-Feeding Strophomenoids Thrived On Muddy Substrates, Benjamin F. Dattilo, Rebecca L. Freeman, Kyle Hartshorn, David Peterman, Aaron Morse, David L. Meyer, Lindsay G. Dougan, James W. Hagadorn

Earth and Environmental Sciences Faculty Publications

Strophomenoid brachiopods had thin, concavo-convex shells, were ubiquitous colonizers of Palaeozoic muddy seafloors, and are hypothesized to have filter-fed in a concave-upward orientation. This orientation would elevate their line of commissure out of potentially lethal lophophore-clogging mud. The paradox is that epi- biont distributions on strophomenoids support a convex-upward life position, as do studies of strophome- noid stability and trace fossils formed by strophomenoid sediment-clearing. A premise of the concave-upward orientation hypothesis is a narrow gape, which causes narrow, high velocity inhalant currents, leaving strophomenoids vul- nerable to sediment entrainment. Herein we investigate the gape angle of Rafinesquina using serial …

Joint Environmental And Social Benefits From Diversified Agriculture, Laura Vang Rasmussen, Ingo Grass

Earth and Environmental Sciences Faculty Publications

Agricultural simplification continues to expand at the expense of more diverse forms of agriculture. This simplification, for example, in the form of intensively managed monocultures, poses a risk to keeping the world within safe and just Earth system boundaries. Here, we estimated how agricultural diversification simultaneously affects social and environmental outcomes. Drawing from 24 studies in 11 countries across 2655 farms, we show how five diversification strategies focusing on livestock, crops, soils, noncrop plantings, and water conservation benefit social (e.g., human well-being, yields, and food security) and environmental (e.g., biodiversity, ecosystem services, and reduced environmental externalities) outcomes. We found that …

The Role Of Geomorphological Context In Vegetative Succession Within The Breiðamerkurjökull Glacial Foreland, Lucas Nerbonne

Independent Study Project (ISP) Collection

As glaciers retreat worldwide at an accelerating pace, understanding primary succession in these newly exposed landscapes becomes increasingly critical. This study examines the initial vegetative colonization patterns in glacial forelands, focusing on the influence of geomorphological formations of resulting plant communities. By analyzing vegetative communities in glaciofluvial and push moraine deposits, this study highlights how the more varied, channelized morphologies of fluvial deposits create potential microclimates better conducive to heterogenous plant colonization than the homogenous terrain of the nearby push moraine. Vegetative coverage, sediment size, and species abundance was collected at 480 sites across 6 different historical glacial extents across …

Beneath The Surface: Exploring The Power Of Aquatic Rewilding In Europe, Jose Cornejo

Posters - 2024

This relatively new concept has been used mainly in various European projects that in words of the European Rewilding project, the leading organization in rewilding, is helping preserve Europe biodiversity richness and enhance benefits that nature provides to humans (Rewilding Europe, n.d.). This rewilding method is also applied in the aquatic ecosystem, which is often called marine rewilding or freshwater rewilding, and it can be applied to any freshwater, brackish, or saltwater. Therefore, for the purpose of uniting them we will call it aquatic rewilding.

There are many aquatic restoration projects and research compared to aquatic rewilding projects and organizations …