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Articles 14311 - 14340 of 59516

Full-Text Articles in Earth Sciences

Evaluation Of Carbon Isotopic Chemostratigraphy Of The Cedar Mountain Formation Of Utah, Clayton Forster Aug 2022

Evaluation Of Carbon Isotopic Chemostratigraphy Of The Cedar Mountain Formation Of Utah, Clayton Forster

Graduate Theses and Dissertations

The Lower Cretaceous rocks of Utah preserve the origin of a multitude of dinosaur taxa, spread of angiosperms on the North American continent, and evolution of marsupial and eutherian mammals. However, the timing of deposition of these rocks is not well understood and must be determined to understand climatic controls on these biological events. Estimates of the age of the Cedar Mountain Formation and its constituent members range from Late Jurassic to early Late Cretaceous. Understanding the timing of deposition of the Cedar Mountain Formation is critical to dinosaurian and associated taxa studies as well as paleoclimate reconstructions from within …


Understanding Martian Salts And Their Implications For Liquid Water, Rachel Slank Aug 2022

Understanding Martian Salts And Their Implications For Liquid Water, Rachel Slank

Graduate Theses and Dissertations

Water is one of the key components for life as we know it. The existence of salts on Mars has been a large contributing factor to the possibility of habitability, due to their ability to allow liquid water to remain stable at colder temperatures. Salts, including perchlorates, chlorates, and chlorides, have been detected by multiple landers, rovers, and orbiters, and are now believed to be ubiquitous on Mars. One of the pathways to liquid brine solutions is through deliquescence. Deliquescence is the transition from a solid salt crystal into an aqueous solution when exposed to a humid atmosphere. This research …


A Cross-Scale Nexus: Microbial Functional Genes In Tandem With Molecular-Level Nitrogen Fluxes And Implications For Field-Scale Biogeochemical Processes, Srusti Maddala Aug 2022

A Cross-Scale Nexus: Microbial Functional Genes In Tandem With Molecular-Level Nitrogen Fluxes And Implications For Field-Scale Biogeochemical Processes, Srusti Maddala

Graduate Theses and Dissertations

Nitrogen (N) biogeochemical cycling entails close networking between soil nutrients, plant species and resulting microbial communities, and abiotic factors such as temperature, moisture, and pH. To better understand transformations of N in soil microsites, which are known to be rich in N-cycling behavior, the microdialysis technique was employed to generate in situ data on temporal alterations of N during wetting-drying conditions in both the field and laboratory. The objectives were to 1) determine the lifespan of the microdialysis technique in field conditions, 2) evaluate the ability of the method to yield N fluxes that would be differential between the two …


Evaluation Of Factors That Contribute To Injury To Quizalofop-Resistant Rice From Quizalofop Applied Postemergence, Navdeep Godara Aug 2022

Evaluation Of Factors That Contribute To Injury To Quizalofop-Resistant Rice From Quizalofop Applied Postemergence, Navdeep Godara

Graduate Theses and Dissertations

Quizalofop-resistant rice technology allows for over-the-top applications of quizalofop, an acetyl-coenzyme A carboxylase-inhibiting herbicide. However, quizalofop caused significant injury to quizalofop-resistant rice in some Arkansas fields during the first year of commercialization. Experiments evaluated the effect of early-season soil moisture and nitrogen availability; pre-exposure to low rates of glyphosate and imazethapyr; planting date; and environmental conditions including, soil moisture content, air temperature, and light intensity on quizalofop-resistant rice tolerance to quizalofop applications. All experiments assessed sequential quizalofop applications made to 2-leaf followed by 5-leaf stage of rice. Sequential quizalofop applications alone and with surface irrigation or nitrogen application at the …


Geoarchaeology Of The 1926 Seeberger Excavation - Jackson County, Iowa, Nicolas Duffy, Chad Heinzel Ph.D., Faith Luce, William Green Jul 2022

Geoarchaeology Of The 1926 Seeberger Excavation - Jackson County, Iowa, Nicolas Duffy, Chad Heinzel Ph.D., Faith Luce, William Green

Summer Undergraduate Research Program (SURP) Symposium

In 1926, Paul Nesbitt discovered around 350 shards of clay pottery in Seeberger Cave, located 6 miles north of Maquoketa, Iowa. It is unknown if these artifacts were made in Iowa, or brought over from neighboring states. For this project, Dr. Heinzel, Faith Luce and I traveled to the area to collect samples of clay and stone. We got close to the cave, but didn’t have the equipment to cross the river at the time. The area we collected our samples from is about 600 meters away from the original site. The samples will be used to characterize the site, …


Geoenvironmental Implications On Food Sovereignty - Meskwaki Settlement, Tama County, Iowa, Lindsey Hubbell, Chad Heinzel Ph.D., Christina Blackcloud, Luke Kapayou, Avis Bear-Bass Jul 2022

Geoenvironmental Implications On Food Sovereignty - Meskwaki Settlement, Tama County, Iowa, Lindsey Hubbell, Chad Heinzel Ph.D., Christina Blackcloud, Luke Kapayou, Avis Bear-Bass

Summer Undergraduate Research Program (SURP) Symposium

Native American culture demonstrates a spiritual relationship to food, land, and Earth. As opposed to European traditions valuing private property and exploiting the Earth for profit, Native American tradition believes the Earth is owned by no one; food and nourishment from it are a gift for all to take only as needed. The Meskwaki Nation originated around the Great Lakes but was removed to Tama County, Iowa. It is derived from the words “Meskwa” meaning “red” and “aki” meaning “Earth”. This Red Earth nation has initiated a Food Sovereignty program to pass along traditional growing and food preparation practices to …


Using Remote And In Situ Observations From Torus To Investigate A Preexisting Airmass Boundary And Its Influence On A Tornadic Supercell On 28 May 2019, Kristen Axon Jul 2022

Using Remote And In Situ Observations From Torus To Investigate A Preexisting Airmass Boundary And Its Influence On A Tornadic Supercell On 28 May 2019, Kristen Axon

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

During the 2019 field phase of Targeted Observation by Radars and UAS of Supercells (TORUS), a preexisting airmass boundary was sampled on 28 May 2019 in north-central Kansas in close proximity to a tornadic supercell. This work hypothesized that the preexisting airmass boundary was associated with a mesoscale air mass with high theta-E (MAHTE) that favorably interacted with the tornadic supercell to increase the likelihood of tornadogenesis. Observations from TORUS including mobile mesonets, unoccupied aerial vehicles, soundings, and ground-based mobile radar were used along with GOES-16 visible satellite imagery, Kansas mesonet surface stations, and KUEX WSR-88D data to investigate this …


The Diatom Dark Ages: Identification Of Mid-Cretaceous Arctic Platform Diatoms From The Basal Transgression Of The Kanguk Formation, Devon Island, Nunavut, Canada, Megan Heins Jul 2022

The Diatom Dark Ages: Identification Of Mid-Cretaceous Arctic Platform Diatoms From The Basal Transgression Of The Kanguk Formation, Devon Island, Nunavut, Canada, Megan Heins

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

The lower part of the mid-Cretaceous Kanguk Formation (Lower Turonian interval) contains an important paleontological record crucial to the characterization of a poorly known interval of fossil marine diatoms history. Kanguk Formation mudstones are exposed in a ~200 m-thick section on Devon Island, Nunavut, Canadian High Arctic. Diatoms at this location are well-preserved due to shallow burial on this Arctic Platform site. The rock sequence was protected from glacial erosion that removed much of the Cretaceous record by being down-faulted in a linear graben. Study of these well-preserved fossil diatoms allows for a documentation of the assemblage, identification of potentially …


Coupling Dendrochronology And Remote Sensing Techniques To Assess The Biophysical Traits Of Juniperus Virginiana And Pinus Ponderosa Within Grassland Communities In The Semi-Arid Grasslands Of The Nebraska Sandhills, Reece Allen Jul 2022

Coupling Dendrochronology And Remote Sensing Techniques To Assess The Biophysical Traits Of Juniperus Virginiana And Pinus Ponderosa Within Grassland Communities In The Semi-Arid Grasslands Of The Nebraska Sandhills, Reece Allen

School of Natural Resources: Dissertations, Theses, and Student Research

Woody species encroachment is occurring within the sandhills region in Nebraska, primarily driven by Juniperus virginiana and Pinus ponderosa, altering ecosystems and the services they provide. Effective, low cost, and cross-scale monitoring of woody species growth and performance is necessary for integrated grassland and forest management in the face of climate variability and change. In this study, we sought to establish a relationship between remote sensing-derived vegetation indices (VIs) and dendrochronological (raw and standardized tree ring width) measurements to assess the performance of encroaching woody J. virginiana and P. ponderosa located within the Nebraska National Forest in the sandhills. …


Spatial Stream Modeling Of Louisiana Waterthrush (Parkesia Motacilla) Foraging Substrate And Aquatic Prey In A Watershed Undergoing Shale Gas Development, Mack W. Frantz, Petra B. Wood, Steven C. Latta Jul 2022

Spatial Stream Modeling Of Louisiana Waterthrush (Parkesia Motacilla) Foraging Substrate And Aquatic Prey In A Watershed Undergoing Shale Gas Development, Mack W. Frantz, Petra B. Wood, Steven C. Latta

United States Geological Survey: Staff Publications

We demonstrate the use of spatial stream network models (SSNMs) to explore relationships between a semiaquatic bioindicator songbird, Louisiana Waterthrush (Parkesia motacilla), and stream monitoring and benthic macroinvertebrate data in an area undergoing shale gas development. SSNMs allowed us to account for spatial autocorrelation inherent to these environmental data types and stream properties that traditional modeling approaches cannot capture to elucidate factors that affect waterthrush foraging locations. We monitored waterthrush along 58.1 km of 1st- and 2nd-order headwater stream tributaries (n = 14) in northwestern West Virginia over a two year period (2013–2014), sampled benthic macroinvertebrates in waterthrush …


Research On Three-Component Responses Characteristics Of Axial Anisotropy Tunnel-Hole Transient Electromagnetic, Guo Jianlei, Gao Xiaowei, Hou Yanwei Jul 2022

Research On Three-Component Responses Characteristics Of Axial Anisotropy Tunnel-Hole Transient Electromagnetic, Guo Jianlei, Gao Xiaowei, Hou Yanwei

Coal Geology & Exploration

Large interpretation errors may exist in exploration areas with obvious conductivity anisotropy when applying tunnel-hole transient electromagnetic method. In this paper, the control equation is built by introducing the conductivity anisotropy tensor, which allows the current density of the rectangular loop source to be added into the Maxwell equation Ampere loop theorem based on the finite difference time domain (FDTD) algorithm in order to realize the loading of any current source. The control equation is discretized by the difference instead of the differential to realize the forward calculation of the tunnel-hole transient electromagnetic 3D model. Forward modeling is carried out …


Imaging Method Of Borehole Transient Electromagnetic Anomaly Response Boundary In Coal Mines Based On Clustering, Fan Tao, Li Ping, Zhang Youzhen, Zhao Rui, Fang Zhe, Fan Yilin, Liu Lei, Wang Cheng, Li Yuteng Jul 2022

Imaging Method Of Borehole Transient Electromagnetic Anomaly Response Boundary In Coal Mines Based On Clustering, Fan Tao, Li Ping, Zhang Youzhen, Zhao Rui, Fang Zhe, Fan Yilin, Liu Lei, Wang Cheng, Li Yuteng

Coal Geology & Exploration

In order to improve the ability to recognize and interpret the abnormal response boundary in the transient electromagnetic inversion imaging results of boreholes in coal mines, and to complete geophysical interpretation such as an accurate description of hidden water disasters in front of the heading face and a fine analysis of hidden disaster-causing factors, this paper proposes the application of apply clustering method of unsupervised machine learning to analyze the borehole transient electromagnetic processing results. According to the numerical distribution characteristics of resistivity and the characteristics of the two clustering methods, the K-Means clustering algorithm is selected to aggregate and …


Application Of Borehole Transient Electromagnetic Method In Detection Of Floor Failure Depth In Fully Mechanized Top Coal Caving Face, Wang Cheng, An Youxin, Zhu Hongjun, Guo Jianlei Jul 2022

Application Of Borehole Transient Electromagnetic Method In Detection Of Floor Failure Depth In Fully Mechanized Top Coal Caving Face, Wang Cheng, An Youxin, Zhu Hongjun, Guo Jianlei

Coal Geology & Exploration

The carboniferous-Permian No. 6 coal seam in the eastern Jungar Coalfield of Ordos Basin is an extra-thick coal seam, and the coal floor is particularly threatened by the Ordovician limestone aquifer. The mining effect will lead to the formation of the bottom mining damage zone, and new water-conducting channels may be formed, which in turn will cause sudden water disasters. Aiming at the testing problem of floor mining failure zone, the method of transient electromagnetic method in hole with moving source and receiving is proposed to obtain resistivity characteristic data of strata from floor drilling before and after mining. Firstly, …


Mechanical Properties And Impact Energy Index Of Coal Affected By Gas Pressure And Evolutionary Mechanism, Ding Xin, Xiao Xiaochun, Pan Yishan Jul 2022

Mechanical Properties And Impact Energy Index Of Coal Affected By Gas Pressure And Evolutionary Mechanism, Ding Xin, Xiao Xiaochun, Pan Yishan

Coal Geology & Exploration

The frequent occurrence of gas emission and outburst accidents caused by rock bursts in deep coal seams poses a great threat to safe underground production. Therefore, clarifying the evolution law of the mechanical properties and burst potential of gas on coal and rock is the basis for establishing effective prevention and control measures. Using the self-developed visual coal fluid-solid coupling test system, we carried out the physical experiment to study the gas adsorption, mechanical properties and fragment distribution of coal affected by gas pressure, and analyzed the evolution characteristics and mechanism of the bursting energy index. The results show that …


Landscape Planning Model Design And Layout Of Loess Hills In Coal Mining Area Of Northern Shaanxi:A Study Of The Subsidence Area Of Ningtiaota Coal Mine, Shang Jianxuan, Gao Yakun, Yang Fan, Bi Yinli, Quan Wenzhi, Ma Shaopeng, Zhang Yanxu Jul 2022

Landscape Planning Model Design And Layout Of Loess Hills In Coal Mining Area Of Northern Shaanxi:A Study Of The Subsidence Area Of Ningtiaota Coal Mine, Shang Jianxuan, Gao Yakun, Yang Fan, Bi Yinli, Quan Wenzhi, Ma Shaopeng, Zhang Yanxu

Coal Geology & Exploration

The coal mining area of northern Shaanxi is an important coal base of China, and the large amount of coal mining will cause surface subsidence and landscape disturbance. Taking the subsidence area of Ningtiaota Mine in northern Shaanxi as an example, this paper comprehensively analyzes the landscape problems in loess hilly landform through the combination of indoor statistical analysis, field investigation, qualitative-quantitative methods. The landscape pattern planning, design and layout are carried out, which provides reference for the landscape planning of underground mine area in this landform types. It is found that there are four problems in the above ground …


Structure Optimization And Drilling Capacity Analysis Of A Self-Propelled Straight-Swirling Mixed Jet Bits, Du Peng, Zhang Wending Jul 2022

Structure Optimization And Drilling Capacity Analysis Of A Self-Propelled Straight-Swirling Mixed Jet Bits, Du Peng, Zhang Wending

Coal Geology & Exploration

As the core part of hydro-jet radial drilling technology for coal-measure gas extraction, the self-propelled jet drill bit has a decisive impact on drilling efficiency. In order to obtain the optimal parameters of the direct rotating mixed jet, the velocity characteristics of the three-dimensional flow field with different bit structure parameters are analyzed by the combination of Fluent numerical simulation and specific experiments, and the optimization criteria are given. The optimal parameters of the drill bit are obtained in the drilling test: the central hole of diameter 1.2 mm, the impeller groove of width 0.7 mm, the impeller of thickness …


Table Of Contents, The Editors Jul 2022

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.


Fast Quantitative Interpretation Of Surface-Borehole Tem Using Transient Impulse Peak Time, Zhi Qingquan, Wu Junjie, Wang Xingchun, Yang Yi, Zhang Jie, Deng Xiaohong Jul 2022

Fast Quantitative Interpretation Of Surface-Borehole Tem Using Transient Impulse Peak Time, Zhi Qingquan, Wu Junjie, Wang Xingchun, Yang Yi, Zhang Jie, Deng Xiaohong

Coal Geology & Exploration

Due to the complex response law of the surface-borehole Transient Electromagnetic Method (TEM), qualitative analysis and semi-quantitative interpretation are the most widely used interpretation methods. However, the methods cannot obtain the resistivity parameter of the earth directly. To solve this problem, a fast quantitative interpretation method based on transient impulse peak time is proposed. Firstly, the expression of uniform half-space surface-borehole transient electromagnetic response is given, and the impulse time characteristics of surface-borehole transient electromagnetic response are analyzed. The results show that the deeper the receiving point is buried and the higher the earth conductivity is, the later the transient …


Application And Effect Evaluation Of Water Cutoff Curtain Technology In Yuanbaoshan Open-Pit Coal Mine, Gao Sheng, Li Guozhi, Guo Yingjie, Tian Zenglin, Shao Dongmei, Zhu Hongjun Jul 2022

Application And Effect Evaluation Of Water Cutoff Curtain Technology In Yuanbaoshan Open-Pit Coal Mine, Gao Sheng, Li Guozhi, Guo Yingjie, Tian Zenglin, Shao Dongmei, Zhu Hongjun

Coal Geology & Exploration

Yuanbaoshan open-pit coal mine of Inner Mongolia is a rare extra large water rich open-pit coal mine at home and abroad. In order to resolve the problems of high production cost and high environmental risk caused by drainage for many years, it is plan to adopt water cutoff curtain technology to closure the seepage supply channel. By analyzing the hydrogeological and engineering geological conditions of the mine, the groundwater water control method of combining arc semi-closed curtain with group wells drainage hydraulic curtain was proposed. The curtain test study was carried out in the mine 452 m flat plate by …


Water Level Evolution Pattern Of Loose Layers Under Water Cutoff Curtain In Ecologically Fragile Open-Pit Mines, Wang Hai, Wang Yonggang, Zhang Yan, Sun Hao, Miao Hechao Jul 2022

Water Level Evolution Pattern Of Loose Layers Under Water Cutoff Curtain In Ecologically Fragile Open-Pit Mines, Wang Hai, Wang Yonggang, Zhang Yan, Sun Hao, Miao Hechao

Coal Geology & Exploration

Eastern Inner Mongolia of China is characterized by a fragile ecological environment and scarce water resources. High-intensity mining in open-pit coal mines has caused drastic changes in the recharge, runoff and discharge of the groundwater system, resulting in a significant drop in the water level of the loose layer, depletion of surface stream flow and destruction of the ecological environment. To reveal the evolution of water level in the loose layer under the water cutoff curtain in ecologically fragile open-pit mines, analyze the characteristics of groundwater distribution in and the influence of mining on the water level of loose layers, …


Ecological Restoration Strategies For Coal Mines In China Based On Vegetation Zones And Ecological Sensitivity, Zhou Hongxuan, Wang Zhaoqing, Pu Hongtong, Tao Guixin, Sun Jing Jul 2022

Ecological Restoration Strategies For Coal Mines In China Based On Vegetation Zones And Ecological Sensitivity, Zhou Hongxuan, Wang Zhaoqing, Pu Hongtong, Tao Guixin, Sun Jing

Coal Geology & Exploration

Coal is the main source of energy in China and the most important driver of our development for a long time. It is predicted that coal is going to be the main energy source for our social and economic development in the future. However, the long-term coal mining activities in China have caused serious damage to the ecological environment and comprehensive ecological restoration is urgently needed. At present, most coal mine ecological restoration is limited within a small scale in China, such as one or several mine areas, lacking of ecological restoration planning at the national spatial level, and corresponding …


Key Technical Progress Of Water Cutoff Curtain Technology In Open-Pit Coal Mines In China, Huang Xuanming, Zhang Yan, Wang Mingxing, Teng Qingshan, Li Guozhi Jul 2022

Key Technical Progress Of Water Cutoff Curtain Technology In Open-Pit Coal Mines In China, Huang Xuanming, Zhang Yan, Wang Mingxing, Teng Qingshan, Li Guozhi

Coal Geology & Exploration

The method of pumping and discharging groundwater is widely used in open-pit coal mines for groundwater control in China to meet the requirements of safe coal mining, which causes great damage to water resources and seriously affects the ecological environment around coal mines. In recent years, with the all-round development of the economy, China has put forward higher requirements for ecological environment protection and ecological civilization construction. How to optimize and change the groundwater control mode and reduce the volume of pit drainage is a new subject generally in water prevention and control of open-pit coal mines. The use of …


Water Control Principle Of Lateral Water Cutoff Curtain And Numerical Analysis Of Its Water Interception Effect In Yuanbaoshan Open-Pit Coal Mine——Taking Yuanbaoshan Open-Pit Coal Mine As An Example, Zhao Chunhu, Wang Mingxing, Cao Haidong, Qu Guowen, Wang Yong, Guo Yingjie Jul 2022

Water Control Principle Of Lateral Water Cutoff Curtain And Numerical Analysis Of Its Water Interception Effect In Yuanbaoshan Open-Pit Coal Mine——Taking Yuanbaoshan Open-Pit Coal Mine As An Example, Zhao Chunhu, Wang Mingxing, Cao Haidong, Qu Guowen, Wang Yong, Guo Yingjie

Coal Geology & Exploration

In the process of open-pit coal mining, drainage is an important aspect causing the loss of groundwater resources. Taking Yuanbaoshan open-pit coal mine in Chifeng City, Inner Mongolia as the research object, this paper analyzes the control principle of the curtain wall construction driven by open-pit mining on the groundwater system according to the hydrogeology of the study area and the characteristics of open-pit coal mine development. It comes to the conclusion that the weaker the permeability of the curtain wall, the greater the thickness, and shortening the distance from the recharge water body is the basic idea of reducing …


Application Of Surface And Borehole Tem Joint Exploration In 2 000 M Deep Mineral Exploration, Wu Junjie, Liu Bin, Zhi Qingquan, Deng Xiaohong, Wang Xingchun, Yang Yi, Liu Dongming, Qiu Jinzhu Jul 2022

Application Of Surface And Borehole Tem Joint Exploration In 2 000 M Deep Mineral Exploration, Wu Junjie, Liu Bin, Zhi Qingquan, Deng Xiaohong, Wang Xingchun, Yang Yi, Liu Dongming, Qiu Jinzhu

Coal Geology & Exploration

Deep mineral exploration is a challenge. The borehole Transient Electromagnetic Method (TEM) goes deep underground through the sensor along the borehole, and gets closer to the deep target, so as to improve the ore discovery rate and prospecting effect. TEM is widely used in deep prospecting and exploration in foreign countries, and has achieved many important results. However, in China, due to the slow development of instruments, theoretical research and interpretation technology, it is less used in practical deep prospecting. This paper introduces a typical case about the 2 000 m deep prospecting in Baiyun Gold Deposit in Qingchengzi, Liaoning …


Present Study Situation Review Of Borehole Transient Electromagnetic Method, Sun Huaifeng, Zhang Yingying, Zhao Youchao, Liu Yuchao, Zhao Hualiang Jul 2022

Present Study Situation Review Of Borehole Transient Electromagnetic Method, Sun Huaifeng, Zhang Yingying, Zhao Youchao, Liu Yuchao, Zhao Hualiang

Coal Geology & Exploration

In the borehole transient electromagnetic method (TEM), the receiving probe is placed in the borehole, which is different from either aerial or ground TEM. In such methods, as the probe will be closer to the detection target and far away from surface, not only stronger response signals can be observed, but also the interference of various electromagnetic signals outside the borehole can be attenuated effectively. It can meet the demand of meticulous detection with large burial, especially the detection demand of deep blind ore and water hazard. The present situation of using various methods in the study in forward modeling, …


Construction And Application Of Feasibility Evaluation Model For Gas Extraction In Goafs Of Abandoned Coal Mines, Yang Ming, Zhu Lin, Quan Xingyuan, Xu Jing, Liu Maomao, Zhang Tao Jul 2022

Construction And Application Of Feasibility Evaluation Model For Gas Extraction In Goafs Of Abandoned Coal Mines, Yang Ming, Zhu Lin, Quan Xingyuan, Xu Jing, Liu Maomao, Zhang Tao

Coal Geology & Exploration

Against the background of carbon neutrality and carbon peaking policy, the development of gas resources in abandoned coal mines can generate high resource, economic and environmental benefits. The evaluation index system is established through field research and literature review from technical feasibility and economic rationality aspects. The game theory-fuzzy comprehensive evaluation model is established by combining the weighting method of game theory with the fuzzy comprehensive evaluation method. The abandoned Gushuyuan Mine is used as an example to verify the rationality of the evaluation model. The weights of gas resource conditions and gas preservation conditions in the first-level indicators are …


Distribution Characteristics And Formation Mechanism Of High Salinity Groundwater In Northeast Ningdong Coalfield, Jin Dewu, Wang Tiantian, Zhao Baofeng, Li Debin, Zhou Zhenfang, Shang Hongbo Jul 2022

Distribution Characteristics And Formation Mechanism Of High Salinity Groundwater In Northeast Ningdong Coalfield, Jin Dewu, Wang Tiantian, Zhao Baofeng, Li Debin, Zhou Zhenfang, Shang Hongbo

Coal Geology & Exploration

High salinity groundwater is widely and unevenly distributed in northeast Ningdong Coalfield of Ningxia Hui Autonomous Region, and it varies greatly throughout the coalfield. This paper studies the distribution characteristics and formation mechanism of high salinity groundwater. Firstly, spatial distribution characteristics of high salinity groundwater was researched, and then, Piper trilinear graph, Gibbs graph and ion proportionality coefficient were used to investigate the formation mechanism of high salinity groundwater. The results show that groundwater salinity value varies from 0.30 g/L to 23.56 g/L, and the average value is 5.84 g/L. The proportions of fresh water, brackish water, salt water and …


Influence Of Coal Mining On Shallow Groundwater Environment Response To Coal Mining And Mine Water Ecological Utilization Analysis, Chai Jianlu Jul 2022

Influence Of Coal Mining On Shallow Groundwater Environment Response To Coal Mining And Mine Water Ecological Utilization Analysis, Chai Jianlu

Coal Geology & Exploration

The contradiction between coal and water is prominent in the upper and middle reaches of the Yellow River Basin, and coal mining activities has caused certain damage to groundwater environment in those areas. So the quantity and quality characteristics of mine water for the Yushenfu mining area in Yulin City of northern Shaanxi Province were analyzed to reveal the influence of coal mining on the groundwater environment, and the ecological utilization study of mine water was also carried out based on field investigation, data analysis and laboratory tests. The results show that the mine water content coefficient in the study …


Evaluation Of Resources And Environment Carrying Capacity Of Xilinhot Mining Area Based On Multi-Source Data, Sun Jundong, Song Renzhong, Li Feiyue, She Changchao, Guo Tianyu, Li Jun, Zhang Chengye Jul 2022

Evaluation Of Resources And Environment Carrying Capacity Of Xilinhot Mining Area Based On Multi-Source Data, Sun Jundong, Song Renzhong, Li Feiyue, She Changchao, Guo Tianyu, Li Jun, Zhang Chengye

Coal Geology & Exploration

The mining and depletion of coal resources have a certain degree of impact on the environment and population of the coal mining area. Confronted with the resources and environment problems, China strongly advocates the construction of green mines, requiring that mine exploitation must be within resources and environment carrying capacity. With the support of multi-source data (Landsat 8, GF-2, etc.) and socio-economic statistics data, Analytic Hierarchy Process was used to construct an index system for evaluating resources and environment carrying capacity of the mining area in Xilinhot, Inner Mongolia from two aspects of the carrying background and the carrying statu. …


Techniques Of Double-Pipe And Double-Acting Directional Drilling With Air In Broken And Soft Coal Seams In Underground Coal Mines, Wang Li Jul 2022

Techniques Of Double-Pipe And Double-Acting Directional Drilling With Air In Broken And Soft Coal Seams In Underground Coal Mines, Wang Li

Coal Geology & Exploration

In the broken and soft coal seam drilling, the outburst and collapse of the hole occur easily, resulting in shallow drilling depth and low rate of hole forming, which seriously restrict the efficient gas control in the broken and soft coal seam. With the rise of gas control models, such as replacing roadway with holes and progressive drainage of the broken and soft coal seam, higher requests have been put forward to the gas drainage hole. The further improvement of the drilling depth, drilling accuracy and hole forming rate of the broken and soft coal seam can meet the needs …