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Articles 1231 - 1260 of 6952

Full-Text Articles in Engineering

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, …


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 …


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, …


Exploring A Fly Ash-Based Grouting Material For Toughening Through In Situ Polymerization Of Acrylamide, Zhang Yuehong, Wang Xiaodong, Wang Hai, Wu Boqiang, Ji Zhongkui, Zhu Shibin, Han Le, Feng Longfei May 2024

Exploring A Fly Ash-Based Grouting Material For Toughening Through In Situ Polymerization Of Acrylamide, Zhang Yuehong, Wang Xiaodong, Wang Hai, Wu Boqiang, Ji Zhongkui, Zhu Shibin, Han Le, Feng Longfei

Coal Geology & Exploration

Efficiently controlling the water inflow (loss) of burnt rocks in the roof of coal mining faces requires grouting reinforcement materials with excellent compressive toughness. Silicate cement-based grouting materials, characterized by low costs, have been extensively applied to grouting reinforcement in coal mines. However, their hardened grout is susceptible to deformation, exhibiting poor toughness. By employing the in-situ polymerization of acrylamide (AM) for toughening, this study investigated the effects of AM, cross-linking agent, initiator, and water-cement ratio on the setting time, swelling capacity, compressive strength, and toughness index of the fly ash-based grouting materials. Furthermore, the microstructures of the hardened grout …


Some Reflections On The Application Of Machine Learning To Research Into The Theoretical System Of Mine Water Prevention And Control, Yao Hui, Yin Huichao, Liang Manyu, Yin Shangxian, Hou Enke, Lian Huiqing, Xia Xiangxue, Zhang Jinfu, Wu Chuanshi May 2024

Some Reflections On The Application Of Machine Learning To Research Into The Theoretical System Of Mine Water Prevention And Control, Yao Hui, Yin Huichao, Liang Manyu, Yin Shangxian, Hou Enke, Lian Huiqing, Xia Xiangxue, Zhang Jinfu, Wu Chuanshi

Coal Geology & Exploration

The theoretical system of mine water prevention and control encompasses three fundamental aspects: disaster-causing mechanisms, risk evaluation, and disaster prediction. This theoretical system, having undergone rapid development over the past 20 years, aims to gain insights into the behavior characteristics of mine water and predict its evolutionary trend, thus serving the prevention and control of water disasters in mining areas. Applying machine learning, a powerful tool for data analysis and mining in the era of big data, to research into the theoretical system has garnered considerable attention. This study focuses on the specific applications of machine learning to the three …


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 …


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 …


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, …


Advective And Diffusive Gas Phase Transport In Vadose Zones: Importance For Defining Vapour Risks And Natural Source Zone Depletion Of Petroleum Hydrocarbons, Kaveh Sookhak Lari, Greg B. Davis, John L. Rayner, Trevor P. Bastow May 2024

Advective And Diffusive Gas Phase Transport In Vadose Zones: Importance For Defining Vapour Risks And Natural Source Zone Depletion Of Petroleum Hydrocarbons, Kaveh Sookhak Lari, Greg B. Davis, John L. Rayner, Trevor P. Bastow

Research outputs 2022 to 2026

Quantifying the interlinked behaviour of the soil microbiome, fluid flow, multi-component transport and partitioning, and biodegradation is key to characterising vapour risks and natural source zone depletion (NSZD) of light non-aqueous phase liquid (LNAPL) petroleum hydrocarbons. Critical to vapour transport and NSZD is transport of gases through the vadose zone (oxygen from the atmosphere, volatile organic compounds (VOCs), methane and carbon dioxide from the zone of LNAPL biodegradation). Volatilisation of VOCs from LNAPL, aerobic biodegradation, methanogenesis and heat production all generate gas pressure changes that may lead to enhanced gas fluxes apart from diffusion. Despite the importance of the gaseous …


Investigating The Effects Of Suspended Algal Content, Dissolved Oxygen, And Temperature On A High-Frequency Acoustic Attenuation System In A Controlled Laboratory Environment, Noah Watson May 2024

Investigating The Effects Of Suspended Algal Content, Dissolved Oxygen, And Temperature On A High-Frequency Acoustic Attenuation System In A Controlled Laboratory Environment, Noah Watson

Honors Theses

The Single Frequency Acoustic Attenuation System (SFAAS) has been developed at the National Center for Physical Acoustics (NCPA). This system uses acoustic methods to monitor fine suspended sediment concentration in streams. Site-specific calibrations are necessary for this system, and previous research has indicated that algal concentration or dissolved oxygen concentration of water may affect collected data. Temperature, dissolved oxygen concentration, and fluorescence, used as a proxy for algal concentration, were monitored during this system’s use, and calibrations were derived to account for the effect of each of these variables on acoustic measurements. It has been shown that temperature has a …


Revitalizing Turtle Creek Park, Michael Hardyway, Ethan Harm, Abbey Jacoby, Casey Stephenson May 2024

Revitalizing Turtle Creek Park, Michael Hardyway, Ethan Harm, Abbey Jacoby, Casey Stephenson

Final Reports in ENST 411: Environmental Community Projects

We current ENST 411 students, Abbey Jacoby, Michael Hardyway, Ethan Harm, and Casey Stephenson have chosen to work with Jim Knight, East Buffalo Township, the Merrill Linn Land and Waterways Conservancy, and many others in an attempt to revitalize Turtle Creek Park for a plethora of reasons. Three of us are majoring in biology, and two are majoring in environmental science, which makes much of the information and techniques relevant in Turtle Creek applicable to our courses of study. This project included heavy hands on work which allowed us students to leave a memorable and impactful influence on the Lewisburg …


Bibliometric Review Of The Landscape And Thematic Structure Of Research On Sustainable Mining In Asean, 1942–2022, Nathatai Janjirawatna, Sirisuhk Rakthin, Philip Hallinger May 2024

Bibliometric Review Of The Landscape And Thematic Structure Of Research On Sustainable Mining In Asean, 1942–2022, Nathatai Janjirawatna, Sirisuhk Rakthin, Philip Hallinger

Journal of Sustainable Mining

This bibliometric review addressed the lack of consolidated information on the current state of sustainable mining in the ASEAN region. The review analyzed bibliographic data associated with 539 Scopus-indexed documents on sustainable mining in ASEAN nations published through the end of 2022. Descriptive statistics identified a great disparity in the scope of research on sustainable mining practices across the ASEAN countries. Surprisingly, a significant portion of the extant research on sustainable mining in the region has been authored by scholars from outside of ASEAN. Keyword analyses highlighted several emerging research topics including life cycle assessment, conservation of natural resources, climate …


Investigating The Impact Of Secondary Activation Time On The Adsorption Properties Of Activated Biochar For Arsenic Removal From Wastewater, Achyuth Bharadwaj Rayarao May 2024

Investigating The Impact Of Secondary Activation Time On The Adsorption Properties Of Activated Biochar For Arsenic Removal From Wastewater, Achyuth Bharadwaj Rayarao

Graduate Theses and Dissertations (2019 - present)

Biochar, a naturally occurring and renewable carbon material, becomes porous through activation. Activated biochar is an ideal candidate for use as an adsorbent. The objective of this study is to investigate whether activated biochar derived from Colorado soft pine serves as a better adsorbent and demonstrates enhanced adsorption capabilities after undergoing secondary physical activation at various activation times. The effect of secondary action time on physical adsorption properties drawn from the analysis of isotherm plots, surface areas and pore size patterns were examined by using a physisorption analyzer. Chemical structures were identified using both ultimate and proximate analyses, while porosity …


Machine Learning And Geostatistical Approaches For Discovery Of Weather And Climate Events Related To El Niño Phenomena, Sachi Perera May 2024

Machine Learning And Geostatistical Approaches For Discovery Of Weather And Climate Events Related To El Niño Phenomena, Sachi Perera

Computational and Data Sciences (PhD) Dissertations

El Nino and La Nina are worldwide environmental phenomena brought about by repetitive changes in the water temperature of the Pacific Ocean. Even though the El-Nino impact focuses on a smaller area in the Pacific Ocean near the Equator, these developments have global repercussions, where temperature and precipitation are influenced across the globe, causing droughts and floods simultaneously. In this dissertation, we first derived a drought vulnerability index for the Nile basin, identifying regions with high and low drought risk under ENSO conditions. Next, we evaluated the coherence and periodicity of the ENSO signal to detect its implications on MENA …


Free And Forced Vibrations Of Elastically Restrained Cantilever With Lumped Oscillator, Alireza Babaei, Johné Parker, Paria Moshaver May 2024

Free And Forced Vibrations Of Elastically Restrained Cantilever With Lumped Oscillator, Alireza Babaei, Johné Parker, Paria Moshaver

Earth and Environmental Sciences Faculty Publications

The efficiency assessment of cantilever-based energy harvesters relies on vibrational analysis, which necessitates modi- fications aimed at enhancing efficiency. These modifications involve manipulating the fundamental frequency to lower values and encompassing a wider range of resonances within a specified bandwidth. Consequently, this paper introduces an original analytical-numerical exploration into the vibratory response of a cantilever with a novel boundary condi- tion involving an elastically restrained oscillator-spring arrangement. At the microbeam’s tip, an oscillator is elastically confined by a linear spring, resulting in a novel set of coupled governing equations and a distinct shearing boundary condition. Microbeam equations is derived from …


Maximization Of Brackish Water Productivity For The Sustainable Production Of Striped Catfish (Pangasianodon Hypophthalmus) And Grain Sorghum (Sorghum Bicolor (L.) Moench) Cultivated Under An Integrated Aquaculture–Agriculture System, Fahad Kimera, Muziri Mugwanya, Khaled Madkour, Mahmoud A.O. Dawood, Hani Sewilam May 2024

Maximization Of Brackish Water Productivity For The Sustainable Production Of Striped Catfish (Pangasianodon Hypophthalmus) And Grain Sorghum (Sorghum Bicolor (L.) Moench) Cultivated Under An Integrated Aquaculture–Agriculture System, Fahad Kimera, Muziri Mugwanya, Khaled Madkour, Mahmoud A.O. Dawood, Hani Sewilam

Faculty Journal Articles

Freshwater scarcity, salinity, and poor soil fertility are the major challenges affecting both food and feed productions in arid and semi-arid regions of the world. Utilization of brackish water in the production of saline-tolerant fish and valuable field crops under an integrated system is promising in the maximization of yield per crop. The aim of this study, therefore, was to (1) assess the effect of saline aquaculture wastewater on the growth, yield, forage quality, and nutritive composition of sorghum seeds and (2) assess the effect of different water qualities on the survival, growth performance, and health status of Pangasianodon hypophthalmus. …


Bidding Strategy For A Wind Power Producer In Us Energy And Reserve Markets, Anne Stratman May 2024

Bidding Strategy For A Wind Power Producer In Us Energy And Reserve Markets, Anne Stratman

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

Wind power is one of the world's fastest-growing renewable energy resources and has expanded quickly within the US electric grid. Currently, wind power producers (WPPs) may sell energy products in US markets but are not allowed to sell reserve products, due to the uncertain and intermittent nature of wind power. However, as wind’s share of the power supply grows, it may eventually be necessary for WPPs to contribute to system-wide reserves. This paper proposes a stochastic optimization model to determine the optimal offer strategy for a WPP that participates in the day-ahead and real-time energy and spinning reserve markets. The …


Innovative Rate Design As A Free Market Solution To Climate, Resiliency, And Economic Challenges, Brendan J. Moore May 2024

Innovative Rate Design As A Free Market Solution To Climate, Resiliency, And Economic Challenges, Brendan J. Moore

LSU New Orleans Theses and Dissertations

A century-old problem of electricity rate design is cost-shifting between ratepayers (Wellinghoff, J. & Tong, J., 2015). A much newer cost-shifting example of great and increasing importance happens whenever ratepayer generated “renewable energy” is sold to the grid—all too often, this is accused of being unfairly rewarded (Ritchie, 2016). ProRate resolves both these concerns and ProRate can actually be derived simply from the premise of avoiding “all” cost shifts between ratepayers (Katz, CLEPm Rewards to Arrest Demand Cost-Shifting, 2019; Katz, CLEP5 Rewards to Arrest Energy Cost-Shifting, 2019). Another major problem with the Old Utility Model is the lack of price …


Examining The Relationship Between Manning's Roughness Coefficient And Stage, Henry Holtkamp May 2024

Examining The Relationship Between Manning's Roughness Coefficient And Stage, Henry Holtkamp

Biological and Agricultural Engineering Undergraduate Honors Theses

This paper uses LOESS regression to predict Manning's roughness coefficient to calculate flows in natural stream channels. Manning's roughness coefficient can introduce variability into Manning's equation, potentially destabilizing results. Utilizing LOESS to find n based on backcalculated n from collected discharge vs. stage information is the best way to acquire accurate Manning's roughness coefficient values at a variety of flows. Book values tend to drastically overestimate which can have wide-ranging implications for water allocation, flood management, maintaining environmental flows, and maintaining water quality.


Bay Water Level Influences On Inundation And Morphological Changes Of A Semi-Connected Barrier Island During A Hurricane, Sydney D. Goodman May 2024

Bay Water Level Influences On Inundation And Morphological Changes Of A Semi-Connected Barrier Island During A Hurricane, Sydney D. Goodman

Graduate Theses and Dissertations (2019 - present)

This research aims to identify flooding and erosion changes along a semi-connected barrier island system due to varying bay water levels during storm conditions. The numerical model XBeach is used to simulate Hurricane Michael conditions and the resulting inundation and morphological change near Tyndall Air Force Base (Tyndall AFB). The installation is located 12 miles southeast of Panama City Beach along the panhandle of Florida and is vulnerable to flooding due to its proximity to the Gulf of Mexico (GoM), Saint Andrew Sound and Saint Andrew Bay. A land bridge connects the barrier island to the mainland of Tyndall AFB …


Boron-Doped Diamond As A Resilient Electrode Material In Molten Salts, Hannah Katherine Patenaude May 2024

Boron-Doped Diamond As A Resilient Electrode Material In Molten Salts, Hannah Katherine Patenaude

UNLV Theses, Dissertations, Professional Papers, and Capstones

Molten salt chemistry has a range of applications within nuclear technology, including for the Molten Salt Reactors (MSRs) and pyroprocessing to recover valuable actinides for energy and national security needs. However, the high-temperature, corrosive nature of molten salts makes them particularly challenging to deploy on an industrial scale and study in benchtop measurements. Material accountability and corrosion monitoring of MSR fuels are essential components to the successful deployment of MSRs, and electroanalytical techniques like cyclic voltammetry (CV) and spectroelectrochemistry (SEC) can provide a wealth of information to describe salt systems in situ. To perform such measurements, it is imperative to …


Designed For Life: Unearthing Just And Sustainable Urban Design Through The Daylighting Of Phalen Creek, Corgan R. Archuleta Apr 2024

Designed For Life: Unearthing Just And Sustainable Urban Design Through The Daylighting Of Phalen Creek, Corgan R. Archuleta

Geography Honors Projects

This thesis conceptualizes a relational approach to urban design. Often separated from justice, I argue urban design can shape spaces to enable respectful and reciprocal human and more-than- human relationships. Focusing on Phalen Creek in Saint Paul, Minnesota, I illuminate just and sustainable possibilities between ecologically sustainable and socially inclusive design. Phalen Creek was a natural waterway buried in a pipe during 20th century urbanization to be partially reconstructed through daylighting. The Indigenous and Immigrant stories driving restoration expand urban design’s liberatory potential. Combining just sustainabilities with infrastructure theory and Indigenous Knowledges, I contend urban design offers a relational approach …


Table Of Contents, The Editors Apr 2024

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.


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 Apr 2024

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 …


Prediction Of Mine Water Inflow Along Mining Faces Using The Ssa-Cg-Attention Multifactor Model, Ding Yingying, Yin Shangxian, Lian Huiqing, Liu Wei, Li Qixing, Qi Rongrong, Bu Changsen, Xia Xiangxue, Li Shuqian Apr 2024

Prediction Of Mine Water Inflow Along Mining Faces Using The Ssa-Cg-Attention Multifactor Model, Ding Yingying, Yin Shangxian, Lian Huiqing, Liu Wei, Li Qixing, Qi Rongrong, Bu Changsen, Xia Xiangxue, Li Shuqian

Coal Geology & Exploration

Predicting mine water inflow plays an important role in ensuring mine safety, optimizing resource allocation, and improving work efficiency. This study aims to improve the accuracy and stability of the predicted mine water inflow. Given their strong correlations with water inflow, borehole water level and microseismic energy were chosen as multifactor characteristic variables. Using these variables, this study developed the SSA-CG-Attention multifactor prediction model for mine water inflow along mining faces. The new model extracted effective nonlinear local features of data utilizing a new network structure, which was formed by integrating a convolutional neural network (CNN) based on the time …


Intelligent Identification Method For Overburden Three Zones Of A Goaf, Li Jianwen, Zhao Wen, Wu Zhenkun, Xu Xiaobing, Wang Qingtao, Duan Longchen Apr 2024

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 …


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 Apr 2024

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 Apr 2024

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 …


Sulphate Contamination In An Abandoned Coal Mine In Light Of Mining Effects, Qi Yueming, Zhou Pei, Zhou Lai, Jiang Dan, Yang Yuqing, Liu Yanzhuo Apr 2024

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 …


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 Apr 2024

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 …