Earth Sciences Commons^™

R&D And Application Of An Experimental System For Coal Permeability Enhancement Through Resonance Under The Excitation Of Low-Frequency Vibration, Wen Zhihui, Guo Shuqian, Wei Jianping, Zhang Tiegang, Wang Jianwei, Zhang Libo, Ren Yongjie

Coal Geology & Exploration

Objective As an emerging green, efficient method for enhancing coal permeability, coal resonance under the excitation of vibration waves works by stimulating the development of pores and fractures in coals using the stress waves generated by low-frequency vibration. To investigate the impacts of excitation frequency, stress field, and resonance effect on permeability enhancement, as well as exploring the mechanisms behind coal permeability enhancement using the method, this study independently designed and developed an experimental system. Methods The system, consisting of a mainframe control unit, a coal-sample clamping unit, a vibrational excitation unit, and a coal vibration parameter monitoring unit, allows …

A Tin-Gtp Algorithm-Based Technique For 3d Geological Modeling Of Coal Mines, Wang Xiaohui, Liu Zaibin, Zhang Dongliang, Ma Liang, Chen Baohui, Lei Xiaorong, Bai Baojun, Yan Junsheng

Coal Geology & Exploration

Background A 3D geological model of a coal mine serves as an essential prerequisite to guiding the safe and efficient production of coal mines, holding great significance for precise coal mining and geological guarantee. Especially in complex geologic conditions, the failure of geological models to accurately describe the relationship between structures and strata will affect the mining area planning, mining processes, and production efficiency during the production of coal mines. Methods With the Qipanjing Coal Mine in the Zhuozishan Coalfield, Inner Mongolia, as an example, this study investigated the technology for high-accuracy 3D geological modeling of coal mines based on …

Accumulation Mechanisms And Resource Potential Of Helium In Coal Measures: A Case Study Of The Eastern Margin Of The Ordos Basin, Liu Xiangbai, Tao Shizhen, Yang Xiuchun, Zhao Qun, Chen Yanyan, Liu Ziyang, Pei Xiangbing, Wang Longfei, Yi Wei, Feng Jianqiu, Zhang Tan, Gao Jianrong, Tao Xiaowan, Liu Zhuangxiaoxue, Li Chaozheng, Yang Yiqing, Chen Yue

Coal Geology & Exploration

Background Helium, with advantages such as stable chemical properties and high thermal conductivity, has been extensively applied in high-tech sectors like national defense, military, aviation, and aerospace, playing an irreplaceable role. Presently, helium in China is primarily imported from other countries, manifesting a high degree of dependence on foreign trade, suggesting a prominent issue concerning helium resource security. Previous studies on helium principally focus on conventional natural gas, rendering helium in coal measures relatively under-studied. Objective and Methods To determine the distribution and potential of helium resources in coal measures, this study analyzed the coal-measure gas sampled from the eastern …

Coal Permeability Enhancement Via Cyclic Percussion Using Low-Temperature Liquid Co2 And High-Temperature Water Vapor And Simulations Of Resultant Gas Drainage Performance, Qin Lei, Wang Ping, School Of Civil And Resource Engineering, University Of Science And Technology Beijing, Beijing 100083, China Shugang, Wang Hui, Liu Pengfei, Li Jiawei, Lin Haifei

Coal Geology & Exploration

Objective In the application of the coal seam permeability enhancement technique based on liquid CO₂, pore water in coal seams freezes due to low temperatures, blocking pathways for gas migration. Hence, this study developed a technique for coal permeability enhancement through cyclic percussion using low-temperature liquid CO₂ and high-temperature water vapor (also referred to as the cyclic cold and hot percussion). Methods This study delved into the permeability evolutionary patterns of coals under cyclic cold and hot percussion using a low-field nuclear magnetic resonance (NMR) spectrometer, an automatic coal permeability tester, a contact angle tester, and 3D …

Deep Beam Theory-Based Mechanical Analysis Of Water-Resisting Key Strata Of Coal Seam Floors In A Deep Mining Environment, Wang Bingwen, Zha Wenhua, Lu Haifeng

Coal Geology & Exploration

Objective An increase in the mining depth of mines poses a more serious threat from highly confined karst water, resulting in water hazards like water inflow and inrushes on the mining faces of coal seams. The key content used to address this issue is to analyze the water pressure resistance of the water-resisting key stratum of the coal seam floor in a deep mining environment. Methods This study simplified a water-resisting key stratum into a rock beam model and then dealt with this model using the deep beam theory in the prediction of water inrushes in deep mining. Specifically, by …

Fracture Mechanical Criteria And Simulation Of Floors With Y-Shaped Branches Of Major Faults In Coal Mines, Li Ang, Sun Jingxin, Zhang Wenzhong, Zhang Zhuang, Yang Yuxuan, Wang Weidong, Lyu Wei, Fan Liuyi

Coal Geology & Exploration

Objective Despite wide distribution, the branches of major faults (also referred to as the fault branches) tend to be overlooked. However, they represent one of the primary causes of water inrush. Methods Under the engineering geological background of the Liuzhuang coal mine in Anhui Province, this study established a fracture mechanical disaster model for fault branches under the impacts of both seepage and stress based on the criteria for compression-shear fracture of rock masses considering the Mohr-Coulomb criterion. Using this model, this study obtained the critical water pressure and the minimum safe distance between the fault branch and the floor's …

Elastoplastic Stress Analysis Of Multi-Refrigerant Combined Heterogeneous Artificial Frozen Wall, Wang Bin, Liang Xiuling, Zhang Zihao, Cai Haibing, Rong Chuanxin

Coal Geology & Exploration

Objective Affected by the temperature difference of the refrigerant and the distance difference between the frozen formation and the freezing pipes, the heterogeneity of the multi-refrigerant combined double-row-pipe frozen wall is more significant. In order to evaluate the safety of such frozen wall reasonably, the elastic plastic stress analysis should be carried out for the artificial frozen wall with multi-refrigerant considering the heterogeneity. Methods The frozen wall at 1/4 pipe distance was selected as the characteristic section. Then, the temperature distribution curve on this section was equivalently converted to three linear functions, and the frozen wall was regarded as a …

Analytical Model For Reactive Solute Transport In A Channel-Matrix System, Wei Nana, Li Xu, Xu Guangquan, Zhang Haitao, Shao Zefan

Coal Geology & Exploration

Objective The accurate quantitative characterization of fractured media and the theoretical research on solute transport in fractured media have become the key to the prevention and control of groundwater contamination in fractured aquifers. Currently, fractured aquifers are generalized to horizontal fractures, ignoring the geometric characteristics of the open parts of fractures, called channels, and the impacts of matrix diffusion on solute transport. Methods A model for solute transport in a single channel-matrix system was established, obtaining the semi-analytical solutions using Laplace and numerical inverse transforms. The COMSOL Multiphysics software was employed to construct a numerical model for verification. Furthermore, the …

Landslide Sensitivity Assessment Of Coal Mining Subsidence Areas Based On Information Value - Machine Learning Coupling Models, Niu Chenhao, Jiao Runcheng, Han Jianfeng, Wang Shengyu, Guo Xuefei, Liu Chang, Han Yucheng, Song Guofeng

Coal Geology & Exploration

Objective Due to their special geological conditions and coal mining background, coal mining subsidence areas are prone to suffer from ground cracks and subsidence, which tend to further induce geological disasters such as landslides. This makes it extremely necessary to conduct landslide sensitivity assessment of these areas using appropriate influencing factors and training models. Methods This study investigated the Xishan coal mine area in Beijing as an example to conduct landslide sensitivity assessment of coal mining subsidence areas by coupling slope units with mathematical statistical and machine learning models. With 10 influencing factors, including topographic and geomorphic factors such as …

Research And Application Of The Seismic Exploration Technique Using Reflected In-Seam Waves In Identifying Folds And Faults In Coal Seams, Wu Guoqing

Coal Geology & Exploration

Background Accurately identifying subsurface anomalies is crucial to building a geological transparency system in the transformation to intelligent coal mines. The precise exploration of fold anomalies is a challenge of underground geophysical exploration technology, holding great significance for reducing excavation costs, mining difficulties, and safety risks. Objective and Methods Previous in-seam seismic explorations reveal that folds pose significant impacts on the propagation characteristics of in-seam waves. However, conventional inversion techniques of in-seam waves are difficult to distinguish folds from faults. This study constructed numerical models for faults and folds with similar geometric shapes and equal exploration distances. Specifically, the differences …

A Method For Reconstructing Consecutively Missing Seismic Data Based On Recurrent Feature Reasoning, Li Zijuan, Chang Guangyao, Jia Yongna

Coal Geology & Exploration

Objective Due to the constraints of natural environments like rapids, rifts, and high mountains, the acquired seismic data are often challenged by consecutive missing, affecting subsequent seismic data processing and geologic analysis. Hence, it is necessary to reconstruct the missing data through interpolation. Methods This study proposed a method for reconstructing consecutively missing seismic data based on recurrent feature reasoning. First, the missing seismic data undergo partial convolution operations, in which the weight of the convolution results is adaptively adjusted based on the proportion of valid feature map data in the receptive field, avoiding invalid convolution operations on consecutively missing …

A Neural Network-Based Method For Analyzing Diffracted Wave Velocity, Tao Junhong, Zhao Jingtao, Sheng Tongjie

Coal Geology & Exploration

Background In seismic imaging, accurate velocity models are crucial for characterizing subsurface structures in a fine-scale manner. Notably, in coal mining, small-scale geological structures like faults and collapse columns are closely associated with mining accidents. These structures typically occur as diffracted waves in seismograms.Objective and Methods To effectively image these small-scale geological bodies, fine-scale velocity modeling using diffracted wave information is particularly important. Hence, this study proposed a neural network-based method for analyzing diffracted-wave velocity. First, diffracted-wave velocity spectra were generated using the gathers of diffracted waves that were separated in the common virtual source domain. Second, a gamma-ray …

Key Technology And Practice Of Deep Borehole Pneumatic Directional Drilling In Broken-Soft Coal Seam In Yangquan Mining Area, Liu Fei, Li Quanxin, Fang Jun, Liu Jianlin, Yang Weifeng, Chu Zhiwei, Zhao Jianguo, Wang Siyi

Coal Geology & Exploration

Objective In response to the need for precise, proactive, and regional management of gas in the broken-soft coal seam of the Yangquan Mining Area, a technical scheme utilizing pneumatic directional drilling for pre-drainage boreholes was proposed. Methods Based on the analysis of the technical challenges in pneumatic directional drilling, a series of technologies suitable for the broken-soft coal seam in the Yangquan Mining Area were developed. These include stable operation technology for pneumatic downhole motors, precise control technology for drilling boreholes, efficient deep-hole slag discharge technology, and pneumatic milling and salvage technology. The pneumatic directional drilling equipment was optimized, and …

Emergency Response And Critical Technologies For Large-Diameter Boreholes In Mine Rescue Through Surface Drilling, Ma Tan, Zhuge Lei, Zhao Weidong

Coal Geology & Exploration

Objective Large-diameter lifesaving holes have been successfully applied multiple times in mine rescue through surface drilling. However, they show limitations in emergency response like quick dispatch and cross-regional rescue, and their technological adaptability is insufficient to cope with complex strata. Methods From the perspective of overall emergency rescue, with rescue timeliness as an indicator, this study summarized the critical technologies like response capability enhancement and borehole-forming technology for complex strata. It constructed an emergency handling process for mine rescue through surface drilling, specified the improvements in contingency plan activation, response actions, and response speeds, and established the hierarchical cross-regional rescue …

Accumulation Patterns And Exploitation And Utilization Targets Of Geothermal Resources In The Coal-Bearing Area In North China, Pang Zhonghe, Duan Zhongfeng

Coal Geology & Exploration

Objective China is a major producer and consumer of coal resources in the world. The urgent need for the transition of the coal industry necessitates the investigation of both the origin and distribution patterns of geothermal resources in the coal-bearing areas of the country. The coal-bearing area in North China, with geothermal reserves accounting for 74.7% of the whole country, stands out as one of the areas with the most abundant geothermal resources nationally. This area encompasses four major coal-bearing basins: the Bohai Bay, Ordos, Qinshui, and Southern North China, with the lithospheric thermal state gradually weakening from east to …

Convection - Heat Transfer Coupling Mechanism For Closed-Loop Heat Extraction From Hydrothermal Resources Using Horizontal Wells, Gu Feng, Li Youwu, Zhang Yue, Gao Ying, Yang Peng, Wang Anran, Cui Jingyun

Coal Geology & Exploration

Objective Closed-loop heat extraction technology, which extracts geothermal energy without draining geothermal water, has emerged as a research focus in geothermal energy exploitation. However, there is a lack of studies on the impacts of convection in reservoirs on heat transfer. Methods To improve single-well heat extraction, this study proposed a technology of closed-loop heat extraction from hydrothermal reservoirs using horizontal wells. This technology aims to increase the contact area between wellbores and reservoirs while fully leveraging the convection in reservoirs. A flow and heat transfer model characterized by the coupling of horizontal wells, circulating water and reservoirs was established to …

A Call For Better Understanding Household Complexity In Environmental Social Science, Rebecca Nixon, Brooke Mcwherter, Anna Erwin, Jonathan Bauchet, Zhao Ma

School of Earth, Environmental, & Marine Sciences Faculty Publications

No abstract provided.

An Automated Machine Learning Approach To The Retrieval Of Daily Soil Moisture In South Korea Using Satellite Images, Meteorological Data, And Digital Elevation Model, Nari Kim, Soo-Jin Lee, Eunha Sohn, Mija Kim, Seonkyeong Seong, Seung Hee Kim, Yangwon Lee

Institute for ECHO Articles and Research

Soil moisture is a critical parameter that significantly impacts the global energy balance, including the hydrologic cycle, land–atmosphere interactions, soil evaporation, and plant growth. Currently, soil moisture is typically measured by installing sensors in the ground or through satellite remote sensing, with data retrieval facilitated by reanalysis models such as the European Centre for Medium-Range Weather Forecasts (ECMWF) Reanalysis 5 (ERA5) and the Global Land Data Assimilation System (GLDAS). However, the suitability of these methods for capturing local-scale variabilities is insufficiently validated, particularly in regions like South Korea, where land surfaces are highly complex and heterogeneous. In contrast, artificial intelligence …

Carbon Isotope Budget Indicates Biological Disequilibrium Dominated Ocean Carbon Storage At The Last Glacial Maximum, Anne Willem Omta

Faculty Scholarship

Understanding the causes of the ~90 ppmv atmospheric CO2 swings between glacial and interglacial climates is an important open challenge in paleoclimate research. Although the regularity of the glacial-interglacial cycles hints at a single driving mechanism, Earth System models require many independent physical and biological processes to explain the full observed CO2 signal. Here we show that biologically sequestered carbon in the ocean can explain an atmospheric CO2 change of 75 ± 40 ppmv, based on a mass balance calculation using published carbon isotopic measurements. An analysis of the carbon isotopic signatures of different water masses indicates similar regenerated carbon …

Revisiting The Chronology Of Loess In North America By Using Sar-Osl And Pirir Protocols, Anca Avram

FRONTIERS UNBOUND: Exploring Extreme Environments

No abstract provided.

Preliminary Analysis Of Quartz Using Scanning Electron Microscopy Techniques, Serban Constantin Grecu, Alida Timar-Gabor

FRONTIERS UNBOUND: Exploring Extreme Environments

No abstract provided.

Hadean Recipes, Stephen Mojzsis

FRONTIERS UNBOUND: Exploring Extreme Environments

No abstract provided.

Editorial: Critical Praxis And The Social Imaginary For Sustainable Food Systems, Max Stephenson Jr., Kim Niewolny, Laura Zanotti, Anna Erwin

School of Earth, Environmental, & Marine Sciences Faculty Publications

No abstract provided.

Scientific History, Sampling Approach, And Physical Characterization Of The Camp Century Subglacial Material, A Rare Archive From Beneath The Greenland Ice Sheet, Paul R. Bierman, Andrew J. Christ, Catherine M. Collins, Halley M. Mastro, Juliana Souza, Pierre Henri Blard, Stefanie Brachfeld, Zoe R. Courville, Tammy M. Rittenour, Elizabeth K. Thomas, Jean Louis Tison, François Fripiat

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Basal materials in ice cores hold information about paleoclimate conditions, glacial processes, and the timing of past ice-free intervals, all of which aid understanding of ice sheet stability and its contribution to sea level rise in a warming climate. Only a few cores have been drilled through ice sheets into the underlying sediment and bedrock, producing limited material for analysis. The last of three Camp Century ice cores, which the U.S. Army collected in northwestern Greenland from 1963-1966 CE, recovered about 3.5 m of subglacial material, including ice and sediment. Here, we document the scientific history of the Camp Century …

Root Lesion And Burrowing Nematodes And Their Management, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Nematodes are common soil pests that feed on the roots of a wide range of crops in all agricultural areas of Western Australia, resulting in significant crop yield loss. Root lesion nematode can be managed but not eradicated.

This factsheet summarises the biology of the root lesion nematode (RLN, Pratylenchus spp.) and burrowing nematode (Radopholus spp.) species that damage Western Australian (WA) crops, and their diagnosis and management.

Roly Poly And Its Management, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Roly poly, also known as prickly saltwort or tumbleweed (Salsola australis), is a native species found throughout Australia. The dead plants can break off at ground level, forming the ‘tumbleweeds’ seen in movies.

Like most summer weeds, roly poly uses soil moisture and nutrients that would otherwise be available to the following crop. The time taken to clear uncontrolled plants can delay seeding.

Livestock will graze the young plants; however, they will not eat the mature plants and are injured by the prickly leaves.

Nitrate Removal By Floating Treatment Wetlands Under Aerated And Unaerated Conditions: Field And Laboratory Results, Jenna Mccoy, Matt Chaffee, Aaron Mittelstet, Tiffany L. Messer, Steve Comfort

Earth and Environmental Sciences Faculty Publications

Urban and storm water retention ponds eventually become eutrophic after years of receiving runoff water. In 2020, a novel biological and chemical treatment was initiated to remove accumulated nutrients from an urban retention pond that had severe algae and weed growth. Our approach installed two 6.1 m × 6.1 m floating treatment wetlands (FTWs) and two airlift pumps that contained slow-release lanthanum composites, which facilitated phosphate precipitation. Four years of treatment (2020–2023) resulted in median nitrate-N concentrations decreasing from 23 μg L−1 in 2020 to 1.3 μg L−1 in 2023, while PO4-P decreased from 42 μg L−1 to 19 μg …

Planetary Health Learning Objectives: Foundational Knowledge For Global Health Education In An Era Of Climate Change, Kathryn H. Jacobsen, Caryl E. Waggett, Pamela Berenbaum, Brett R. Bayles, Gail L. Carlson, René English, Carlos A Faerron Guzmán, Meredith L. Gartin, Liz Grant, Thomas L. Henshaw, Lora L. Iannotti, Philip J. Landrigan, Nina Lansbury, Hao Li, Maureen Y. Lichtveld, Ketrell Mcwhorter, Jessica E. Rettig, Cecilia J. Sorensen, Eric J. Wetzel, Dawn Michele Whitehead, Peter J. Winch, Keith Martin

Earth and Environmental Sciences Faculty Publications

Planetary health is an emerging field that emphasises that humans depend on a healthy Earth for survival and, conversely, that the sustainability of Earth systems is dependent on human behaviours. In response to member demands for resources to support teaching and learning related to planetary health, the Consortium of Universities for Global Health (CUGH) convened a working group to develop a set of planetary health learning objectives (PHLOs) that would complement the existing ten CUGH global health learning objectives. The eight PHLOs feature Earth system changes, planetary boundaries, and climate change science; ecological systems and One Health; human health outcomes; …

Open Groundwater Drains In Wa, Department Of Primary Industries And Regional Development, Western Australia

Natural resources factsheets

Open groundwater drains are excavated channels with sloping floors and sides and open levees, designed to intercept and drain surface (usually fresh) and groundwater (usually saline in WA) from agricultural land. These drains are most effective where the channel is dug below a water table in soils that allow good lateral drainage.

DPIRD recommends leveed groundwater drains in most cases. These should form part of a whole farm and whole catchment integrated water and salinity management program. Information on this page is a guide only. It is highly recommended that landholders considering the construction of open drains seek expert advice …

Investigation Of Temperature, Solution Strength, And Applied Stress Effects On Cation Exchange Processes In Different Geosynthetic Clay Liner Products, Kendra Fuller

Master's Theses

An extensive laboratory test program was conducted to analyze and compare the cation exchange processes in three different varieties of sodium bentonite (Na-B) geosynthetic clay liners (GCLs) over increased conditioning durations up to 32 days and investigate the effects of temperature, solution strength, and applied stress. The goal of this test program was to establish whether the variables of temperature, solution strength, and applied stress improved or degraded the engineering properties of GCLs in laboratory testing and municipal solid waste (MSW) landfill applications. The GCLs were conditioned in liquids of increasing ionic strength, using deionized water and 2, 50, and …