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Articles 14461 - 14490 of 59520

Full-Text Articles in Earth Sciences

Machine Learning Applied To A Modern-Pleistocene Petrographic Data Set: The Global Prediction Of Sand Modal Composition (Gloprsm) Model, J. Isaac Johnson, Glenn R. Sharman, Eugene Szymanski, Xiao Huang Jun 2022

Machine Learning Applied To A Modern-Pleistocene Petrographic Data Set: The Global Prediction Of Sand Modal Composition (Gloprsm) Model, J. Isaac Johnson, Glenn R. Sharman, Eugene Szymanski, Xiao Huang

Geosciences Faculty Publications and Presentations

Petrography has long been used as a tool to decipher the sedimentary provenance of sand and sandstone based on relative proportions of detrital grain types. However, there is not yet a predictive framework that constrains the relationship between sand grain composition and the factors that influence it, including bedrock lithology, elevation, slope, basin area, precipitation, and temperature. We used a globally extensive modal point-count data set of 3,522 Pleistocene to modern sand samples to train an inline series of random forest meta-estimators to predict relative abundances of quartz (Q), feldspar (F), and lithic (L) grain types and eight subcompositions. The …

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Reactive Iron Mineral Coatings In Redox Transition Zones Of A Site With Historical Contamination: Abiotic Attenuation, Xin Yin May 2022

Reactive Iron Mineral Coatings In Redox Transition Zones Of A Site With Historical Contamination: Abiotic Attenuation, Xin Yin

Dissertations

Reactive iron mineral coatings are found throughout reduction-oxidation (redox) transition zones and play a significant role in contaminant transformation processes. In this study, an 18.3-meter core is collected, subsampled, and preserved under anoxic conditions to maintain its original redox state. Screening analyses are conducted at sampling increments of 5.08 cm in depth for the following: elemental concentrations with X-ray fluorescence (XRF), sediment pH, sediment oxidation-reduction potential (ORP), total volatile organic carbon (TVOC) in the sample headspace, and abundant bacteria (16S rRNA sequencing). Using the Fe and S gradients correlated with microbial data, five RTZs are delineated. To characterize iron mineral …

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Petrographic And Geochemical Records Of Climate Perturbation In Carbonates From A Perennially Ice-Covered Antarctic Lake, Jared Clance May 2022

Petrographic And Geochemical Records Of Climate Perturbation In Carbonates From A Perennially Ice-Covered Antarctic Lake, Jared Clance

Earth and Planetary Sciences ETDs

Carbonate precipitation in perennially ice-covered Lake Fryxell, McMurdo Dry Valleys, Antarctica produces a modern analog for Antarctic paleolake carbonates. Lake Fryxell contains a steep oxycline in the photic zone, where dissolved oxygen falls from supersaturation to zero. In the lake’s benthic microbial mats, oxygen concentrations are higher than in the water column due to microbial photosynthesis. These mats contain carbonate cements that precipitated in a discrete episode from mat pore waters. Precipitation continued through seasonal fluctuations in oxygenation, demonstrated by variable concentrations of oxidized and reduced manganese and iron within carbonates. Carbonates precipitated out of isotopic equilibrium with the lake …

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Correlations Between The Rotations And Magnetospheres Of The Terrestrial Planets And The Sun's Formation In Our Solar System, Fred J. Cadieu May 2022

Correlations Between The Rotations And Magnetospheres Of The Terrestrial Planets And The Sun's Formation In Our Solar System, Fred J. Cadieu

Publications and Research

Correlations between the rotations of the terrestrial planets in our solar system and the magnetic field of the Sun have been previously noted. These correlations account for the opposite rotation of Venus as a result of the magnetic field of the Sun being dragged across the conducting core of Venus. Currently the Sun’s magnetic field is not sufficiently strong to account for the proposed correlations. But recently meteorite paleomagnetism measurements have indicated that during the Sun’s formation the magnetic field of the Sun was of sufficient strength to have resulted in the observed correlations. As a part of these correlations …

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Where To Invest Project Efforts For Greater Benefit: A Framework Formanagement Performance Mapping With Examples For Potato Seed Health, C. E. Buddenhagen, Y. Xing, J. L. Andrade-Piedra, G. A. Forbes, P. Kromann, I. Navarrete, S. Thomas-Sharma, Robin A. Choudhury, K. F. Andersen Onofre, E. Schulte-Geldermann May 2022

Where To Invest Project Efforts For Greater Benefit: A Framework Formanagement Performance Mapping With Examples For Potato Seed Health, C. E. Buddenhagen, Y. Xing, J. L. Andrade-Piedra, G. A. Forbes, P. Kromann, I. Navarrete, S. Thomas-Sharma, Robin A. Choudhury, K. F. Andersen Onofre, E. Schulte-Geldermann

School of Earth, Environmental, & Marine Sciences Faculty Publications

Policymakers and donors often need to identify the locations where technologies are most likely to have important effects, to increase the benefits from agricultural development or extension efforts. Higher-quality information may help to target the high-benefit locations, but often actions are needed with limited information. The value of information (VOI) in this context is formalized by evaluating the results of decision making guided by a set of specific information compared with the results of acting without considering that information. We present a framework for management performance mapping that includes evaluating the VOI for decision making about geographic priorities in regional …

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The Concept Of Tectonic Provenance: Case Study Of The Gigantic Markagunt Gravity Slide Basal Layer, Danika F. Mayback, Michael J. Braunagel, David H. Malone, W. Ashley Griffith, Mckenna E. Holliday, Tiffany A. Rivera, Robert F. Biek, David B. Hacker, Peter D. Rowley May 2022

The Concept Of Tectonic Provenance: Case Study Of The Gigantic Markagunt Gravity Slide Basal Layer, Danika F. Mayback, Michael J. Braunagel, David H. Malone, W. Ashley Griffith, Mckenna E. Holliday, Tiffany A. Rivera, Robert F. Biek, David B. Hacker, Peter D. Rowley

Faculty Publications - Geography, Geology, and the Environment

Formation and evolution of the basal layer in large landslides has important implications for processes that reduce frictional resistance to sliding. In this report, we show that zircon geochronology and tectonic provenance can be used to investigate the basal layer of the gigantic-scale Markagunt gravity slide of Utah, USA. Basal layer and clastic injectite samples have unique tectonic chronofacies that identify the rock units that were broken down during emplacement. Our results show that basal material from sites on the former land surface is statistically indistinguishable and formed primarily by the breakdown of upper plate lithologies during sliding. Decapitated injectites …

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Public Preferences For Renewable Energy Options: A Choice Experiment In Rwanda, Sydney Oluoch, Pankaj Lal, Andres Susaeta, Rodrigue Mugabo, Michel Masozera, Jackline Aridi May 2022

Public Preferences For Renewable Energy Options: A Choice Experiment In Rwanda, Sydney Oluoch, Pankaj Lal, Andres Susaeta, Rodrigue Mugabo, Michel Masozera, Jackline Aridi

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Rwanda has seen impressive economic growth in the past few years resulting from policy driven initiatives. However, one of the key challenges to economic development in Rwanda has been the provision of reliable and cost-effective energy. As a result, the country has planned to expand its renewable energy portfolio to meet its energy demand and mitigate greenhouse gas (GHG) emissions. Meeting these goals requires a robust policy framework that considers the perspective of the public. Moreso, for women who have been disproportionately affected by climate change especially in developing countries. Gender equality is a key for the Rwanda strategy as …

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Toxicological Responses To Sublethal Anticoagulant Rodenticide Exposure In Free‑Flying Hawks, Nimish B. Vyas, Barnett A. Rattner, J. Michael Lockhart, Craig S. Hulse, Clifford P. Rice, Frank Kuncir, Kevin Kritz May 2022

Toxicological Responses To Sublethal Anticoagulant Rodenticide Exposure In Free‑Flying Hawks, Nimish B. Vyas, Barnett A. Rattner, J. Michael Lockhart, Craig S. Hulse, Clifford P. Rice, Frank Kuncir, Kevin Kritz

United States Geological Survey: Staff Publications

An important component of assessing the hazards of anticoagulant rodenticides to non-target wildlife is observations in exposed free-ranging individuals. The objective of this study was to determine whether environmentally realistic, sublethal first-generation anticoagulant rodenticide (FGAR) exposures via prey can result in direct or indirect adverse effects to free-flying raptors. We offered black-tailed prairie dogs (Cynomys ludovicianus) that had fed on Rozol® Prairie Dog Bait (Rozol, 0.005% active ingredient chlorophacinone, CPN) to six wild-caught red-tailed hawks (RTHA, Buteo jamaicensis), and also offered black-tailed prairie dogs that were not exposed to Rozol to another two wild-caught RTHAs for 7 …

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Pronounced Changes In Thermal Signals Associated With The Madoi (China) M 7.3 Earthquake From Passive Microwave And Infrared Satellite Data, Feng Jing, Lu Zhang, Ramesh P. Singh May 2022

Pronounced Changes In Thermal Signals Associated With The Madoi (China) M 7.3 Earthquake From Passive Microwave And Infrared Satellite Data, Feng Jing, Lu Zhang, Ramesh P. Singh

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Thermal variations in surface and atmosphere observed from multiple satellites prior to strong earthquakes have been widely reported ever since seismic thermal anomalies were discovered three decades ago. These thermal changes are related to stress accumulation caused by the tectonic activities in the final stage of earthquake preparation. In the present paper, we focused on the thermal changes associated with the 2021 Madoi M 7.3 earthquake in China and analyzed the temporal and spatial evolution of the Index of Microwave Radiation Anomaly (IMRA) and the Index of Longwave Radiation Anomaly (ILRA) based on 8-year microwave brightness temperature (MWBT) and 14-year …

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Specific Properties And Combustion Characteristics Of Natural Coke From Adjacent Areas Of Jiangsu, Shandong, Henan And Anhui Provinces, Qin Yunhu, Wang Shuangmei, Zhu Shifei, Wu Guoqiang, Quan Jutao, Mao Lixin May 2022

Specific Properties And Combustion Characteristics Of Natural Coke From Adjacent Areas Of Jiangsu, Shandong, Henan And Anhui Provinces, Qin Yunhu, Wang Shuangmei, Zhu Shifei, Wu Guoqiang, Quan Jutao, Mao Lixin

Coal Geology & Exploration

It is particularly important to improve resource utilization efficiency against the background of carbon peak and carbon neutrality, but the natural coke has not been paid enough attention for a long time. The natural coke is abundant in China and is often found in the mining of coal mines in neighboring areas of Shandong, Henan and Anhui provinces. Due to the intrusion of magmatic rock, the original coal seam is baked and transformed into natural coke. In this study, samples of natural coke from various areas were collected to study its macroscopic and microscopic characteristics. The industrial analysis, geochemical parameters, …

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Nanopore Structure And Surface Roughness In Brittle Tectonically Deformed Coals Explored By Atomic Force Microscopy, Zhang Ningyuan, Yao Suping May 2022

Nanopore Structure And Surface Roughness In Brittle Tectonically Deformed Coals Explored By Atomic Force Microscopy, Zhang Ningyuan, Yao Suping

Coal Geology & Exploration

The pore structure of coal is the key to coalbed methane (CBM) exploration and exploitation, and coal mining safety. Compared to primary coals, tectonically deformed coals (TDCs) have stronger heterogeneity and are of great importance in coal reservoir study. Here, the pore structure and surface roughness of brittle TDCs were obtained with atomic force microscopy (AFM) and NanoScope Analysis and Gwyddion software. The results show that tectonic deformation generally promotes the pore development in brittle TDCs, but the extent of tectonic impact varies greatly among different brittle TDCs. As a result, two stages in brittle TDCs were identified: weak brittle …

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Evaluation Method And Application Of Fracturing Effect Based On Dynamic Permeability Change Of Coal Reservoir Hydraulic Fracturing, Shan Tuo, Sun Changyan, Wang Qian, Xie Xiangjun, Fan Yigang May 2022

Evaluation Method And Application Of Fracturing Effect Based On Dynamic Permeability Change Of Coal Reservoir Hydraulic Fracturing, Shan Tuo, Sun Changyan, Wang Qian, Xie Xiangjun, Fan Yigang

Coal Geology & Exploration

The fracturing construction curve is considered to be an important basis for reflecting the fracturing effect, while the dynamic change of reservoir permeability in the fracturing stage can more intuitively reflect the effect of fracture formation. In this paper, a quantitative evaluation method for reservoir dynamic permeability in fracturing stage was established based on the principle of well testing. Then, the method was applied to evaluate the fracturing effect of two coalbed methane (CBM) wells in a block in southern Junggar Basin, and the dynamic permeability curve of reservoir during fracturing stage is obtained. Meanwhile, the G-function method was …

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Efficient Treatment Technology Of Incrementally Open Water Gushing Channel Under Dynamic Water Conditions, Pu Zhiguo, Ding Xiang, Li Zhe, Ji Zhuochen, Yan Xin, He Xiaolang, Ma Jianguo May 2022

Efficient Treatment Technology Of Incrementally Open Water Gushing Channel Under Dynamic Water Conditions, Pu Zhiguo, Ding Xiang, Li Zhe, Ji Zhuochen, Yan Xin, He Xiaolang, Ma Jianguo

Coal Geology & Exploration

In Yushen mining area of Shaanxi Province, a blasting expansion fissure on the eastern side of the Xiwan Open-pit Coal Mine communicates the water-bearing body of burnt rock outside the pit, and an incrementally open water gushing channel with a length greater than 65 m is formed. The water volume gushing from burnt rock stabilizes at about 400 m3/h and the flow velocity is as high as 0.36 m/s, resulting in a series of problems in ecology, environmental protection, economy and safety. To block the water gushing channel and solve the problem as soon as possible, a quick …

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Optimization Calculation Of The Width Of Waterproof Coal Pillars In Fault Zones Based On Spatial Relationship Between Coal Strata And Fault, Wu Bin, Xie Daolei, Han Jing, Chen Qiang, Zhang Huide May 2022

Optimization Calculation Of The Width Of Waterproof Coal Pillars In Fault Zones Based On Spatial Relationship Between Coal Strata And Fault, Wu Bin, Xie Daolei, Han Jing, Chen Qiang, Zhang Huide

Coal Geology & Exploration

The appropriate setting width of the waterproof coal pillars is an important measure to prevent water inrush hazard during near fault mining. The working face 123up01(south) of Jining No.3 Coal Mine in Shandong Province is adjacent to F8 fault in the west. The fall of F8 fault is large, which may be conducted with the Ordovician limestone aquifer at the bottom. To ensure the safe mining in the working face, it is necessary to calculate the size of waterproof coal pillars of fault F8. In view of the actual occurrence of coal strata, the spatial relationship between fault …

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Numerical Simulation Of Azimuth Electromagnetic Wave Response Of Complex Geological Model Of Horizontal Hole In Coal Mines, Zhang Yi, Kang Zhengming, Feng Hong, Han Xue, Chen Gang May 2022

Numerical Simulation Of Azimuth Electromagnetic Wave Response Of Complex Geological Model Of Horizontal Hole In Coal Mines, Zhang Yi, Kang Zhengming, Feng Hong, Han Xue, Chen Gang

Coal Geology & Exploration

The advance and accurate identification of the coal-rock interface is one of the key technologies to realize automatic tunneling and intellectualization of coal mines. Azimuth electromagnetic wave tool has a large detection range and can distinguish the lithologic interface and interface orientation. It has been successfully applied in oilfield logging, but there are few researches on the coal mine measurement environment. In order to study the detection performance of azimuth electromagnetic wave logging in the complex 3D model of coal mines, the finite element numerical simulation method is used to investigate the influence of the drilling fluid in the borehole …

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3d Forward Modeling Of Dc Resistivity Method Based On Finite Element With Mixed Grid, Wang Xinyu, Wang Cheng, Mao Yurong, Yan Liangjun, Zhou Lei, Gao Wenlong May 2022

3d Forward Modeling Of Dc Resistivity Method Based On Finite Element With Mixed Grid, Wang Xinyu, Wang Cheng, Mao Yurong, Yan Liangjun, Zhou Lei, Gao Wenlong

Coal Geology & Exploration

The DC resistivity method is widely used in the mineral resources exploration and geological survey industries because of its high efficiency and low cost, such as non-ferrous metals and coal fields. However, in the process of borehole–to–surface and surface–to–borehole resistivity method exploration, the influence of borehole factors (borehole fluid resistivity and borehole diameter) on the apparent resistivity response in different exploration modes is unclear, and whether it will affect the interpretation of apparent resistivity data is an issue worth exploring. Therefore, we proposed a mixed grid finite element method to realize the 3D forward modeling of DC resistivity. Then we …

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Preliminary Investigation Of Uranium Resource Evaluation Method Based On Natural Gamma Logging Data：A Case Study Of The Pengyang Uranium Deposit In Ordos Basin, Yu Reng’An, Sun Dapeng, Zhou Xiaoxi, Deng Fan, Si Qinghong, Hu Yongxing May 2022

Preliminary Investigation Of Uranium Resource Evaluation Method Based On Natural Gamma Logging Data：A Case Study Of The Pengyang Uranium Deposit In Ordos Basin, Yu Reng’An, Sun Dapeng, Zhou Xiaoxi, Deng Fan, Si Qinghong, Hu Yongxing

Coal Geology & Exploration

“Coal and uranium exploration” and “oil and uranium exploration” are current research hotspots. Using logging data of coal and oilfield drilling to further evaluate uranium resources remains a difficult problem. Taking the Pengyang uranium deposit in the Ordos Basin as an example, this article explores the method of evaluating uranium resources based on natural gamma logging data. According to the remarkable features of the natural gamma anomaly response in the sandstone-type uranium reservoirs in the study area, the natural gamma logging regression model of the quantitative gamma logging value of the uranium deposit in the Pengyang area was studied by …

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Study And Application On Multi Branch Point Sampling Drilling Technology Of Coal Seam Floor Borehole, Chu Zhiwei, Long Weicheng, Jia Bingyi, Liu Fei May 2022

Study And Application On Multi Branch Point Sampling Drilling Technology Of Coal Seam Floor Borehole, Chu Zhiwei, Long Weicheng, Jia Bingyi, Liu Fei

Coal Geology & Exploration

According to the technical requirements of long-distance gas parameter measurement, gas extraction borehole design guidance, and extraction evaluation for broken soft coal seam, the multi branch point sampling drilling method of coal seam floor borehole was proposedand its sampling drilling process was formulated on the basis of analyzing existing problems of sampling and drilling technology. Furthermore, the key drilling technologies such as accurate drilling trajectory control and “mechanical + hydraulic” efficient slag removal were developed. The equipment of drilling and sealed sampling were introduced. The application test was carried out in a coal mine in Suzhou, Anhui Province, in which …

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Simplified Internal Variable Gradient Model For Zonal Disintegration Of Rocks In Circular Underground Tunnels, He Ziguang, Zhao Fasuo, Chen Haoxiang, Wu Bo, Zhou Jingjing May 2022

Simplified Internal Variable Gradient Model For Zonal Disintegration Of Rocks In Circular Underground Tunnels, He Ziguang, Zhao Fasuo, Chen Haoxiang, Wu Bo, Zhou Jingjing

Coal Geology & Exploration

As one of the typical nonlinear phenomena of deep level surrounding rock masses, zonal disintegration has captured many attentions of geotechnical engineers in the past years. On the basis of the internal variable theory, the closed-form analytical solutions to stress, strain and displacement fields near circular tunnels are obtained. The gradient-dependent solutions are compared with the results of the classical elasticity theory, and the effects of microstructures on the stresses and deformation fields are investigated as well. It is noted that the stress and deformation fields derived from the gradient model show remarkable quasi-periodicity and fluctuation, which is consistent with …

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Powder Discharge Characteristics Of Pneumatic Double Pipe Directional Drilling In Broken Soft Coal Seams And Its Application, Nie Chao, Wang Yi, Yao Yafeng, Hong Jianjun May 2022

Powder Discharge Characteristics Of Pneumatic Double Pipe Directional Drilling In Broken Soft Coal Seams And Its Application, Nie Chao, Wang Yi, Yao Yafeng, Hong Jianjun

Coal Geology & Exploration

To study the influence of casing, casing bit size and casing rotational speed on pulverized coal discharge in double pipe directional drilling technology, three kinds of casing and casing bits in different sizes are designed respectively against the background of pneumatic double pipe directional drilling in the broken soft coal seam, the changes of the discharge rate and outlet velocity of pulverized coal under different combinations are analyzed, and the influence law of different casing rotational speeds on the suspension rate and conveying trajectory of pulverized coal are obtained. The numerical simulation results show that the ø120/96 mm casing with …

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The Mitogenome Relationships And Phylogeography Of Barn Swallows (Hirundo Rustica), Gianluca Lombardo, Nicola Rambaldi Migliore, Giulia Colombo, Marco Rosario Capodiferro, Giulio Formenti, Manuela Caprioli, Elisabetta Moroni, Leonardo Caporali, Hovirag Lancioni, Simona Secomandi, Cristina Cereda, Valerio Carelli, Lauren Gillespie, Yang Liu, Yosef Kiat, Alfonso Marzal, Cosme López-Calderón, Javier Balbontín, Timothy Mousseau, Piotr Matyjasiak, Anders Pape Møller, Et. Al. May 2022

The Mitogenome Relationships And Phylogeography Of Barn Swallows (Hirundo Rustica), Gianluca Lombardo, Nicola Rambaldi Migliore, Giulia Colombo, Marco Rosario Capodiferro, Giulio Formenti, Manuela Caprioli, Elisabetta Moroni, Leonardo Caporali, Hovirag Lancioni, Simona Secomandi, Cristina Cereda, Valerio Carelli, Lauren Gillespie, Yang Liu, Yosef Kiat, Alfonso Marzal, Cosme López-Calderón, Javier Balbontín, Timothy Mousseau, Piotr Matyjasiak, Anders Pape Møller, Et. Al.

Faculty Publications

The barn swallow (Hirundo rustica) poses a number of fascinating scientific questions, including the taxonomic status of postulated subspecies. Here, we obtained and assessed the sequence variation of 411 complete mitogenomes, mainly from the European H. r. rustica, but other subspecies as well. In almost every case, we observed subspecies-specific haplogroups, which we employed together with estimated radiation times to postulate a model for the geographical and temporal worldwide spread of the species. The female barn swallow carrying the Hirundo rustica ancestral mitogenome left Africa (or its vicinity) around 280 thousand years ago (kya), and her descendants …

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Failure Analysis Of Deep Coal Seam Floor Considering Strain Softening Of Surrounding Rock And Formation Contact In Goaf, Yin Shangxian, Meng Haopeng, Qian Shuangbin May 2022

Failure Analysis Of Deep Coal Seam Floor Considering Strain Softening Of Surrounding Rock And Formation Contact In Goaf, Yin Shangxian, Meng Haopeng, Qian Shuangbin

Coal Geology & Exploration

In order to study the failure mode of the floor in deep coal seam mining, we proposed a FLAC3D finite difference numerical method considering the strain softening of surrounding rock and the contact of goafs .Through the qualitative analysis of Rankine’s earth pressure theory, the failure of the deep coal seam floor is studied based on the measured water conducting fracture zone of the floor in working face 2023 of Linxi Mine. The results show that the mechanical state of surrounding rock after plastic failure can be described more accurately by using the strain-softening constitutive relationship instead of the …

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Temperature Field Analysis Of New Pipe Curtain Freezing Method In River Embankment Anti Seepage Reinforcement, Zhou Yuxuan, Hu Jun, Xiong Hui, Ren Junhao, Zhan Jianjian, Wang Zhixin May 2022

Temperature Field Analysis Of New Pipe Curtain Freezing Method In River Embankment Anti Seepage Reinforcement, Zhou Yuxuan, Hu Jun, Xiong Hui, Ren Junhao, Zhan Jianjian, Wang Zhixin

Coal Geology & Exploration

In order to explore whether the new pipe curtain freezing method can effectively strengthen the river embankment, this paper uses the finite element software to study the application of the new pipe curtain freezing method in anti-seepage and embankment reinforcement based on the temperature field, and sets up four analysis paths to deeply analyze the basic situation of the frozen soil curtain and the freezing effect characteristics of each path. The results show that the frozen soil curtain spreads around after it is formed at the freezing pipe. From the 8th day, the development of the frozen soil curtain on …

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Identification Of Burning Temperature Of Burnt Rocks In Northern Shaanxi Based On Thermoacoustic Emission Technology, Sun Qiang, Wang Shaofei, Ge Zhenlong, Wei Shaoni, Ding Xiaoying May 2022

Identification Of Burning Temperature Of Burnt Rocks In Northern Shaanxi Based On Thermoacoustic Emission Technology, Sun Qiang, Wang Shaofei, Ge Zhenlong, Wei Shaoni, Ding Xiaoying

Coal Geology & Exploration

The identification of the burning temperature of burnt rocks has important guiding significance for the formation and evolution of burnt rocks. Based on the thermal Kaiser effect, the threshold temperature of burnt rock in Zhangjiamao, Shenmu, Northern Shaanxi Province is predicted through the acoustic emission (AE) acumulated energy and the changes of parameters RA (rise time/amplitude) and AF (average frequency) during heat treatment. The results show that the thermoacoustic emission characteristics of burnt rocks can effectively identify the burning temperature of burnt rocks, and it is basically consistent with the petrographic analysis of the temperature experienced by the burnt rocks. …

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Table Of Contents, The Editors May 2022

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.

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A Review：Geological Feasibility And Technological Applicability Of Underground Coal Gasification, Jiang Xiuming, Wu Caifang May 2022

A Review：Geological Feasibility And Technological Applicability Of Underground Coal Gasification, Jiang Xiuming, Wu Caifang

Coal Geology & Exploration

Underground coal gasification (UCG) is a potential new method of coal utilization, which is of great significance for alleviating China’s energy crisis, ensuring national energy security, and achieving carbon peaking and carbon neutrality goals. It has always been valued by countries all over the world. On the suitability of UCG resource conditions, the feasibility of process and technology, and the controllability of environmental impact, this paper summarizes the development status of UCG technology, and clarifies the coal resource reserves suitable for UCG technology, different standards of geological area selection and location selection technology, the development history and applicable conditions of …

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Spatial Distribution Of Harmful Trace Elements In Chinese Coals, Cao Qingyi, Ren Wenying, Liang Chaoming, Zhang Yufei, Yang Liu May 2022

Spatial Distribution Of Harmful Trace Elements In Chinese Coals, Cao Qingyi, Ren Wenying, Liang Chaoming, Zhang Yufei, Yang Liu

Coal Geology & Exploration

The potential impact of harmful trace elements in coal on the ecological environment and human health is one of the hot topics in the fields of geochemistry and energy environment. Geochemical mapping plays an important role in the deep understanding of geochemical processes and their changing laws. However, previous studies have not provided the national geochemical maps of harmful trace elements in Chinese coals. In this study, the content data of 1 167 Be, 1 315 Co, 1 406 Cu, 1 191 Mo, 1 247 Th, and 1 390 Zn in Chinese coal samples are analyzed, and their average contents …

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Accumulation Mode Of Middle-Low Rank Coalbed Methane In Houxia Basin，Xinjiang, Tu Zhimin, Che Yanqian, Li Peng, Lin Wenji May 2022

Accumulation Mode Of Middle-Low Rank Coalbed Methane In Houxia Basin，Xinjiang, Tu Zhimin, Che Yanqian, Li Peng, Lin Wenji

Coal Geology & Exploration

There are successful cases of large-scale CBM development of low-rank coal abroad. Though China is rich in low-rank CBM resources, their exploration and development progress is slow. Considering the low exploration degree and for the purpose of further understanding the accumulation conditions of medium-low rank CBM and guiding exploration practice in Houxia Basin, seismic and geological analysis, as well as coal petrography analysis and drainage production data of drilled wells are carried out in the study area. The results show that the coal seams are characterized by complex structure, large thickness (4.1-24.3 m), stable development, large difference in gas content …

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Eefficient Fracturing Technology And Fine Drainage System Of Ultra-Deep Coalbed Methane In Southeast Chongqing：A Case Study Of Ny1 Well, Fang Dazhi, Cheng Zehu, Li Jiaxin May 2022

Eefficient Fracturing Technology And Fine Drainage System Of Ultra-Deep Coalbed Methane In Southeast Chongqing：A Case Study Of Ny1 Well, Fang Dazhi, Cheng Zehu, Li Jiaxin

Coal Geology & Exploration

According to the results of China’s new round of coalbed methane (CBM) resource evaluation, the CBM development mainly focuses on medium and shallow coal seams, and the geological conditions of deep-ultra deep coal reservoirs are more complicated. Thus, the reservoir fracturing technology and drainage management technology are two major factors in the development of CBM wells for deep coal reservoirs. In the area of southeast Chongqing, the coal seam of Longtan Formation is as deep as nearly 2 000 m, and there is no experience in ultra-deep CBM well development in this area. The NYI well is taken as an …

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Ground Development Technology And Engineering Application Of Cbm In Coal Mine Goafs： A Case Study Of Jincheng Mining Area In Qinshui Basin, Zhou Xianjun, Li Guofu, Li Chao, Wang Zheng, Li Jiangbiao May 2022

Ground Development Technology And Engineering Application Of Cbm In Coal Mine Goafs： A Case Study Of Jincheng Mining Area In Qinshui Basin, Zhou Xianjun, Li Guofu, Li Chao, Wang Zheng, Li Jiangbiao

Coal Geology & Exploration

There are still rich CBM resources in goafs after coal mining, and the resource evaluation, development and utilization have dual significance of environmental protection and resources. In recent years, ground drilling has been actively explored in Jincheng, Xishan and Yangquan mining areas in Shanxi Province to extract CBM in the goafs. However, in the process of ground development of CBM, due to water accumulation in the goafs, confined water gushing from overlying strata and other reasons, there is no gas production or low gas extraction from ground drilling. Taking Yuecheng Coal Mine in Jincheng, Shanxi as an example, this paper …

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