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Articles 8791 - 8820 of 41157

Full-Text Articles in Engineering

Electrochemical Syntheses Of Nanomaterials And Small Molecules For Electrolytic Hydrogen Production, Jia-Qi Wei, Xiao-Dong Chen, Shu-Zhou Li Oct 2022

Electrochemical Syntheses Of Nanomaterials And Small Molecules For Electrolytic Hydrogen Production, Jia-Qi Wei, Xiao-Dong Chen, Shu-Zhou Li

Journal of Electrochemistry

Hydrogen is a clean, efficient, renewable energy resource and the most promising alternative to fossil fuels for future carbon-neutral energy supply. Therefore, sustainable hydrogen production is highly attractive and urgently demanded, especially via water electrolysis that has clean, abundant precursors and zero emission. However, current water electrolysis is hindered by the sluggish kinetics and low cost/energy efficiency of both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). In this regard, electrochemical synthesis offers prospects to raise the efficiency and benefit of water electrolysis by fabricating advanced electrocatalysts and providing more efficient/value-adding co-electrolysis alternatives. It is an eco-friendly and facile …

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Catalytic Effect Of Disordered Ru-O Configurations For Electrochemical Hydrogen Evolution, Xue Sun, Ya-Jie Song, Ren-Long Li, Jia-Jun Wang Oct 2022

Catalytic Effect Of Disordered Ru-O Configurations For Electrochemical Hydrogen Evolution, Xue Sun, Ya-Jie Song, Ren-Long Li, Jia-Jun Wang

Journal of Electrochemistry

Phase engineering is considered as an effective method for modulating the electronic structure and catalytic activity of catalysts. The disordered conformation of amorphous materials allows flexible reforming of the surface electronic structure, showing their attractiveness as catalysts for hydrogen evolution reaction (HER). Herein, we designed and developed an amorphous ruthenium dioxide (a-RuO2) catalyst with a disordered Ru-O configuration. The conformational relationship between Ru-O ordering and HER performance is established by combining advanced electron microscopic techniques with detailed electrochemical tests. Specifically, the disordered Ru-O coordination significantly enhanced the HER catalytic activity in both acidic and alkaline media, ultimately leading …

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Alkaline Water Electrolysis For Efficient Hydrogen Production, Wen-Fu Xie, Ming-Fei Shao Oct 2022

Alkaline Water Electrolysis For Efficient Hydrogen Production, Wen-Fu Xie, Ming-Fei Shao

Journal of Electrochemistry

Hydrogen production from water electrolysis is a sustainable and environmentally benign strategy in comparison with fossil fuel-based hydrogen. However, this promising technique suffers from the high energy consumption and unsatisfactory cost due to the sluggish kinetics of both half reaction and inferior stability of electrocatalysts. To address this challenge, herein, we present a timely and comprehensive review on advances in alkaline water electrolysis that is already commercialized for large scale hydrogen production. The design principles and strategies with aiming to promote the performance of hydrogen generation are discussed from the view of electrocatalyst, electrode, reaction and system. The challenges and …

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Alkaline Seawater Electrolysis At Industrial Level:Recent Progress And Perspective, Tao Zhang, Yi-Pu Liu, Qi-Tong Ye, Hong-Jin Fan Oct 2022

Alkaline Seawater Electrolysis At Industrial Level:Recent Progress And Perspective, Tao Zhang, Yi-Pu Liu, Qi-Tong Ye, Hong-Jin Fan

Journal of Electrochemistry

Industrial hydrogen generation through water splitting, powered by renewable energy such as solar, wind and marine, paves a potential way for energy and environment sustainability. However, state-of-the-art electrolysis using high purity water as hydrogen source at an industrial level would bring about crisis of freshwater resource. Seawater splitting provides a practical path to solve potable water shortage, but still faces great challenges for large-scale industrial operation. Here we summarize recent developments in seawater splitting, covering general mechanisms, design criteria for electrodes, and industrial electrolyzer for direct seawater splitting. Multi-objective optimization methods to address the key challenges of active sites, reaction …

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A Self-Supported Ru-Cu3P Catalyst Toward Alkaline Hydrogen Evolution, Zi-Xuan Wan, Chao-Hui Wang, Xiong-Wu Kang Oct 2022

A Self-Supported Ru-Cu3P Catalyst Toward Alkaline Hydrogen Evolution, Zi-Xuan Wan, Chao-Hui Wang, Xiong-Wu Kang

Journal of Electrochemistry

Transition metal phosphide (TMP) is a kind of effective catalysts toward hydrogen evolution reaction (HER) in alkaline electrolytes. However, the performance of TMP catalysts is strongly limited by water splitting. In this work, we developed a method to prepare a copper foam (CF) supported Ru-doped Cu3P catalyst (Ru-Cu3P/CF) by a consecutive growth of Cu(OH)2 nanoarrays, soaking in RuCl3 solution and phosphorization. A large surface area was obtained by the self-supported catalysts with the appropriative Ru doping. As an excellent HER catalyst, it exhibited a low overpotential of 95.6 mV at a current density of …

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Uncertainty Analysis Of Operational Conditions In Selective Artificial Ground Freezing Applications, Ahmad Zueter, Saad Akhtar, Agus Sasmito Oct 2022

Uncertainty Analysis Of Operational Conditions In Selective Artificial Ground Freezing Applications, Ahmad Zueter, Saad Akhtar, Agus Sasmito

Journal of Sustainable Mining

Artificial ground freezing (AGF) systems are susceptible to uncertain parameters highly affecting their performance. Particularly, selective artificial ground freezing (S-AGF) systems involve several uncertain operational conditions. In this study, uncertainty analysis is conducted to investigate four operational parameters: 1) coolant inlet temperature, 2) coolant flow rate, 3) pipes emissivity, and 4) pipes eccentricity. A reduced-order model developed and validated in our previous work for field-scale applications is exploited to simulate a total of 5,000 cases. The uncertain operational parameters are set according to Monte Carlo analysis based on field observations of a field-scale freeze-pipe in the mining industry extending to …

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An Evaluation Framework For Digital Image Forensics Tools, Zainab Khalid, Sana Qadir Oct 2022

An Evaluation Framework For Digital Image Forensics Tools, Zainab Khalid, Sana Qadir

Journal of Digital Forensics, Security and Law

The boom of digital cameras, photography, and social media has drastically changed how humans live their day-to-day, but this normalization is accompanied by malicious agents finding new ways to forge and tamper with images for unlawful monetary (or other) gains. Disinformation in the photographic media realm is an urgent threat. The availability of a myriad of image editing tools renders it almost impossible to differentiate between photo-realistic and original images. The tools available for image forensics require a standard framework against which they can be evaluated. Such a standard framework can aid in evaluating the suitability of an image forensics …

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Carbonised Fluidised Fly Ash (Cffa); A New Product For Mining Engineering Purposes (Discussion Of Possible Applications), Marian Jacek Łączny, Przemysław Rompalski Oct 2022

Carbonised Fluidised Fly Ash (Cffa); A New Product For Mining Engineering Purposes (Discussion Of Possible Applications), Marian Jacek Łączny, Przemysław Rompalski

Journal of Sustainable Mining

The article presents and summarises the current state of research and laboratory results on the carbonation of fly ash with carbon dioxide in the context of its use in mining engineering. Based on previous publications and patent applications, the possibilities of using carbonated fly ash from fluidised bed boilers for the following applications were discussed: securing excavations particularly susceptible to fire hazards, shotcreting and securing longwalls and supports, constructing cases, securing decommissioned shafts, and others, which means wherever the use of cement is required. It was pointed out that the removal of excess free calcium oxide makes it possible to …

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Addressing Specific Safety And Occupational Health Challenges For The Canadian Mines Located In Remote Areas Where Extreme Weather Conditions Dominate, Rachid Halabi, Mustafa Kumral Oct 2022

Addressing Specific Safety And Occupational Health Challenges For The Canadian Mines Located In Remote Areas Where Extreme Weather Conditions Dominate, Rachid Halabi, Mustafa Kumral

Journal of Sustainable Mining

The number of mining operations is increasing in the Canadian North, where extreme weather conditions govern. Currently, many mine development projects are also in progress in this region. These mines’ working atmosphere and employment circumstances are highly different from regular mines. One of the main differences is the special safety issues of the Canadian North. The primary sources of these special issues are: the difficulty of finding skilled employees; high employee turnover rate; insufficient training and certification requirements; delicate employment circumstances affecting the psychological well-being of employees; permafrost; mine inspection challenges; inventory and logistic hardship; and the legislative and regulative …

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Study On Mechanical Mechanism Of Roof Fracture Evolution In Deep Stope With Variable Face Length, Wang Xinfeng, Lu Mingyuan Oct 2022

Study On Mechanical Mechanism Of Roof Fracture Evolution In Deep Stope With Variable Face Length, Wang Xinfeng, Lu Mingyuan

Coal Geology & Exploration

Irregular coal seam mining is easy to cause the problems such as roof stress concentration and abnormal ground pressure behavior. In order to explore the roof fracture law and the structural evolution characteristics of stope with variable length, the roof structure models with four types of boundary conditions were established and analyzed using the small-deflection thin plate bending theory in view of the geometric characteristics and mechanical causes of the abrupt stope with the inclined length of working face changing from small to large in various mining stages. Meanwhile, the roof fracture law and macro-mechanical response were analyzed by MATLAB …

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Research On Permeability Model Of Coal Reservoir Along Producing Wellbores, Jia Lidan, Zhang Lin, Li Bobo, Wu Xuehai, Gao Zheng, Wang Zhonghui, Fu Jiale Oct 2022

Research On Permeability Model Of Coal Reservoir Along Producing Wellbores, Jia Lidan, Zhang Lin, Li Bobo, Wu Xuehai, Gao Zheng, Wang Zhonghui, Fu Jiale

Coal Geology & Exploration

Permeability is an important parameter to characterize gas flow. In order to ensure the safe and efficient gas drainage, it is necessary to explore the evolution characteristics of coal reservoir gas seepage at different positions from the producing wellbores. However, the effective stress, the gas adsorption/desorption capacity of coal matrix and the temperature of coal reservoir are constantly changing with the gas drainage, and even the drainage damage may occur, which makes the gas migration behavior in coal seam extremely complicated. In order to explore the seepage characteristics of coal reservoir gas during gas drainage, the space-time evolution function of …

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Research And Application Progress Of Energy Underground Structures, Wen Jiwei, Hou Junlong, Liu Xinghong, Zeng Xian’En, Xiang Tian Oct 2022

Research And Application Progress Of Energy Underground Structures, Wen Jiwei, Hou Junlong, Liu Xinghong, Zeng Xian’En, Xiang Tian

Coal Geology & Exploration

Energy geostructure refers to a type of structure equipped with heat exchange pipe in the building foundation element and the underground structure, which has the functions of load bearing and heat exchange. It not only effectively saves the valuable and irreversible underground space resources, but also makes full use of the non-carbon based continuous, stable, safe and clean geothermal energy resources, thus having more advantages than the traditional Ground Source Heat Pump (GSHP). Herein, the concept, advantages, research and application progress of energy geostructure at home and abroad were systematically summarized. Moreover, the current situation of four common energy geostructures, …

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Numerical Simulation Of The Influence Of Karst Structure On Heat Transfer Efficiency Of Buried Pipeline Group, Mu Xuan, Pei Peng, Zhou Xin, Tu Hongsheng Oct 2022

Numerical Simulation Of The Influence Of Karst Structure On Heat Transfer Efficiency Of Buried Pipeline Group, Mu Xuan, Pei Peng, Zhou Xin, Tu Hongsheng

Coal Geology & Exploration

The buried pipeline is the part where the rock mass heat pump system performs direct heat transfer with the ground. The water-bearing structure in the karst area is complex and diverse, which has a significant impact on the heat transfer and storage of the buried pipeline group. Herein, the heat transfer process of a group of 27 vertical buried pipelines in four geological structure types was simulated, including the non-karst structure, fractured karst structure, karst conduit structure and mixed karst structure. Meanwhile, comparison was made for the change of parameters, such as the temperature field in the rock mass, the …

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Numerical Simulation On Azimuth Gamma Ray Detection Of Coal And Rock Interface, Chen Gang, Chen Long, Li Quanxin, Liu Zhiyi Oct 2022

Numerical Simulation On Azimuth Gamma Ray Detection Of Coal And Rock Interface, Chen Gang, Chen Long, Li Quanxin, Liu Zhiyi

Coal Geology & Exploration

In order to meet the requirements of geosteering drilling with LWD azimuth gamma, the response value of gamma ray intensity under different surrounding rock thicknesses and absorption coefficients was studied by numerical simulation. Meanwhile, the variation of special and physical characteristics reflected by API value measured by gamma detector under the radioactive formation conditions was simulated and analyzed. On this basis, the geological model of the three layers of coal, mudstone and limestone of 8-sectors azimuth gamma ray drilling was established to simulate the identification process of roof and floor of coal bed drilled. The simulation results show that the …

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Status And Prospect Of Harmless Disposal And Resource Comprehensive Utilization Of Solid Waste Of Coal Gangue, Wang Yutao Oct 2022

Status And Prospect Of Harmless Disposal And Resource Comprehensive Utilization Of Solid Waste Of Coal Gangue, Wang Yutao

Coal Geology & Exploration

A large amount of coal gangue generated during coal production and processing is piled up on the surface, which not only causes land occupation and soil erosion, but also causes geological disasters such as landslides and debris flows. So it has a serious impact on the ecological environment of the mining area. The cumulative stockpile of coal gangue in China has exceeded 6 billion tons, accounting for 13000 hectares of land. In 2020, the output of coal gangue in China is 729 million tons, the comprehensive utilization is 526 million tons, and the comprehensive utilization rate is 72.2%. At present, …

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Accelerating Multiparametric Mri For Adaptive Radiotherapy, Shraddha Pandey Oct 2022

Accelerating Multiparametric Mri For Adaptive Radiotherapy, Shraddha Pandey

USF Tampa Graduate Theses and Dissertations

MR guided Radiotherapy (MRgRT) marks an important paradigm shift in the field of radiotherapy. Superior tissue contrast of MRI offers better visualization of the abnormal lesions, as a result precise radiation dose delivery is possible. In case of online treatment planning, MRgRT offers better control of intratumoral motion and quick adaptation to changes in the gross tumor volume. Nonetheless, the MRgRT process flow does suffer from some challenges that limit its clinical usability. The primary aspects of MRgRT workflow are MRI acquisition, tumor delineation, dose map prediction and administering treatment. It is estimated that the acquisition of MRI takes around …

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Synthetic Pseudo-Spin-Hall Effect In Acoustic Metamaterials, Matthew Weiner, Xiang Ni, Andrea Alù, Alexander B. Khanikaev Oct 2022

Synthetic Pseudo-Spin-Hall Effect In Acoustic Metamaterials, Matthew Weiner, Xiang Ni, Andrea Alù, Alexander B. Khanikaev

Advanced Science Research Center

While vector fields naturally offer additional degrees of freedom for emulating spin, acoustic pressure field is scalar in nature, and it requires engineering of synthetic degrees of freedom by material design. Here we experimentally demonstrate the control of sound waves by using two types of engineered acoustic systems, where synthetic pseudo-spin emerges either as a consequence of the evanescent nature of the field or due to lattice symmetry. First, we show that evanescent sound waves in perforated films possess transverse angular momentum locked to their propagation direction which enables their directional excitation. Second, we demonstrate that lattice symmetries of an …

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Research And Application Of Integrated Fracturing Fluid System For Unconventional Natural Gas In Coal Measures, Xu Dong, Wang Yubin, Bai Kunsen, Zhu Weiping, Liu Chuanqing, Li Bing, He Pengbo Oct 2022

Research And Application Of Integrated Fracturing Fluid System For Unconventional Natural Gas In Coal Measures, Xu Dong, Wang Yubin, Bai Kunsen, Zhu Weiping, Liu Chuanqing, Li Bing, He Pengbo

Coal Geology & Exploration

To solve the problems of poor application flexibility and non-adjustable performance of the current fracturing fluid system in unconventional natural gas of coal measures, an integrated fracturing fluid system is researched. In this study, the experimental evaluation was performed for the viscosity increase, drag reduction, sand suspension, temperature and shear resistance, gel breaking, additive compatibility, anti-swelling and surface tension of the integrated fracturing fluid system based on three kinds of integrated thickeners in combination with the field clay stabilizer, cleanup additive and gel breaker. Meanwhile, the field application effect of integrated fracturing fluid was analyzed. The results show that: the …

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Svm-Based Sensitivity Zoning Of Subsidence Disaster Development In The Underground Coal Mining Areas, Xue Yong’An, Zou Youfeng, Zhang Wenzhi, Zhang Mingmei, Liu Guangchun Oct 2022

Svm-Based Sensitivity Zoning Of Subsidence Disaster Development In The Underground Coal Mining Areas, Xue Yong’An, Zou Youfeng, Zhang Wenzhi, Zhang Mingmei, Liu Guangchun

Coal Geology & Exploration

At present, there is no fixed way to predict the sensitive zones of subsidence disaster development in underground coal mining areas, and the prediction result of sensitive zones has a great uncertainty. Herein, the subsidence disaster in Xishan area of Taiyuan City, Shanxi Province was taken as the research object. Totally 4 types of kernel SVM based prediction model for sensitivity zoning of subsidence disaster were constructed with the methods of GIS spatial analysis, statistical analysis and Support Vector Machine (SVM) in combination, taking the subsidence disaster data checked and recorded in 2012 and 2014 as the modeling and verification …

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Table Of Contents, The Editors Oct 2022

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.

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Occurrence Law Of Coal Seam Gas Under Influence Of Normal Fault Zone In Coal Measures, Xiao Peng, Wu Mingchuan, Shuang Haiqing, Han Kai, Gao Zhen, Cheng Yueying Oct 2022

Occurrence Law Of Coal Seam Gas Under Influence Of Normal Fault Zone In Coal Measures, Xiao Peng, Wu Mingchuan, Shuang Haiqing, Han Kai, Gao Zhen, Cheng Yueying

Coal Geology & Exploration

The coal measure fault zone generated by the superimposition of the polytropic movement and multiple structure has important effects on the coal seam gas occurrence. The method of combining the geologic analysis, COMSOL Multiphysics numerical simulation and field data monitoring was adopted to analyze the interaction relations between the stress distribution characteristics and faults of the normal fault zone in the coal measure, study the coal seam permeability variation characteristics influenced by the normal fault zone in the coal measure, and simulate the gas migration status and concentration distribution condition after the formation of the normal fault zone. The coal …

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Occurrence Modes And Stepwise Chemical Extraction Experiment Of Lithium In No.20 Coal Seam In Pu’An Mining Area, Guizhou Province, Cheng Chen, Song Yang, Zang Jingkun, Cheng Wei Oct 2022

Occurrence Modes And Stepwise Chemical Extraction Experiment Of Lithium In No.20 Coal Seam In Pu’An Mining Area, Guizhou Province, Cheng Chen, Song Yang, Zang Jingkun, Cheng Wei

Coal Geology & Exploration

Lithium (Li) is an important energy metal, and the global demand for Li has grown rapidly in recent years. The discovery of coal-associated Li deposits in China proves that coal mines may serve as a potential alternative of Li resources. No.20 coal seam in Pu’an mining area in Guizhou province of China was selected as the study object. The basic properties, mineral composition, elemental composition, and occurrence modes of Li of the raw coal and six density-graded samples (obtained through a float-sink test) were determined by using coal proximate analysis, optical microscope, X-Ray fluorescence spectroscopy (XRF), inductively coupled plasma mass …

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Numerical Simulation On Evolution Law Of Overburden Fractures And Surface Cracks In Crossing Ditch Mining Of Shallow Coal Seam, Wei Jiangbo, Wang Shuangming, Song Shijie, Sun Qiang Oct 2022

Numerical Simulation On Evolution Law Of Overburden Fractures And Surface Cracks In Crossing Ditch Mining Of Shallow Coal Seam, Wei Jiangbo, Wang Shuangming, Song Shijie, Sun Qiang

Coal Geology & Exploration

Crossing ditch mining of shallow coal seam is common in northern Shaanxi mining area, which seriously threatens the safe production and the sound ecological development. The mining-induced overburden fractures and surface cracks are developed as a result of the extension and expansion of microcracks in rock mass. In order to more systematically study the evolution law of overburden microcracks in crossing ditch mining of shallow coal seam, a numerical model of particle flow in coal mining was established with the Particle Flow Code (PFC) numerical simulation platform according to the field ditch profile and borehole data under the background of …

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Experimental Study On Stress Relaxation Characteristics Of Soft Dredger Fill Under Uu Triaxial Shear, Yang Aiwu, Yang Shaopeng, Qi Jiejie Oct 2022

Experimental Study On Stress Relaxation Characteristics Of Soft Dredger Fill Under Uu Triaxial Shear, Yang Aiwu, Yang Shaopeng, Qi Jiejie

Coal Geology & Exploration

Stress relaxation often occurs in the saturated soft clay with poor water permeability under the actual working condition at fast construction speed (fast loading rate), which brings huge hidden dangers to the safe operation of engineering practice. Herein, the unconsolidated undrained triaxial shear test was performed based on the soft dredger fill in Tianjin Binhai using the WF stress path triaxial instrument, and the influence law of such factors as the different initial strain, confining pressure, shear rate, sampling depth and structural properties of the soft dredger fill on its stress relaxation characteristics was analyzed accordingly. According to the test …

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Spatial Variation Characteristics Of Soil Heavy Metal Speciation And Bioavailability In Coal Gangue Accumulation Area—Taking Fengfeng Mining Area As An Example, Sun Tao, Song Shijie, Chang Qing, Wang Chenchen, Zhang Yanjie, Peng Ruisi, Wang Yi Oct 2022

Spatial Variation Characteristics Of Soil Heavy Metal Speciation And Bioavailability In Coal Gangue Accumulation Area—Taking Fengfeng Mining Area As An Example, Sun Tao, Song Shijie, Chang Qing, Wang Chenchen, Zhang Yanjie, Peng Ruisi, Wang Yi

Coal Geology & Exploration

The surface accumulation of coal gangue is a typical form of ecological environment destruction in the eastern coal mining area of China, and the prevention and control of heavy metal pollution in the soil in the accumulation area has become a hot spot in the current research. Taking the shallow soil (with a vertical depth of 40 cm and below) around a coal gangue mountain (within a radius of 300 m) in use in the Fengfeng mining area of Hebei as the research object, the active state, iron manganese oxidation state, organic state and residue state of four kinds of …

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Effect Of Initial Adhesion On Shear Strength And Deformation Characteristics Of Interfaces In Heterogeneous Soils, Zhu Yanbo, Yang Fanfan, Miao Shuaisheng, Li Futong, Zhang Yuxuan Oct 2022

Effect Of Initial Adhesion On Shear Strength And Deformation Characteristics Of Interfaces In Heterogeneous Soils, Zhu Yanbo, Yang Fanfan, Miao Shuaisheng, Li Futong, Zhang Yuxuan

Coal Geology & Exploration

In the Loess Plateau of China, the interface between the Loess and Hipparion Red Clay is widely distributed. The initial adhesion between this interfaces plays an important role in its shear strength. To investigate the effect of initial adhesion on shear strength and deformation characteristics of the interfaces, we firstly performed a series of direct shear experiments. Then, we discussed the effects of initial adhesion on failure mode, shear deformation and shear strength of interfaces. The results indicate that the failure modes of interfaces with initial adhesion and interfaces without initial adhesion are different. The initial adhesion improves the sliding …

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Time-To-Depth Conversion Accuracy Analysis And Improvement Method For Inclined Coal Bed, Wang Huifeng, Fu Chao, Li Guo, Chen Tongjun Oct 2022

Time-To-Depth Conversion Accuracy Analysis And Improvement Method For Inclined Coal Bed, Wang Huifeng, Fu Chao, Li Guo, Chen Tongjun

Coal Geology & Exploration

The average-velocity method is the most commonly-used time-to-depth conversion technology for the seismic survey of coalbed. But for the steeply-inclined coalbed, the average velocity changes rapidly laterally, and the interpretation accuracy varies greatly, so that the intelligent coal mining could not be assured effectively. Herein, the accuracy of various average-velocity-interpolation methods was discussed by analyzing a steeply-inclined coalbed model and a practical 3D seismic mining area and appropriate improvement methods were proposed accordingly. The calculation results of a forward model show that the bottom elevation accuracy of coalbed is greatly affected by the locations of interpolation points in the case …

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Design And Application Of Pump-Free Double Channel Mechanical Hole Enlarging Bit For Gas Penetration In Middle Hard Coal Seam, Gao Xiaoliang, Shao Guojie, Yang Huwei Oct 2022

Design And Application Of Pump-Free Double Channel Mechanical Hole Enlarging Bit For Gas Penetration In Middle Hard Coal Seam, Gao Xiaoliang, Shao Guojie, Yang Huwei

Coal Geology & Exploration

In borehole enlarge drilling, it is necessary to adjust the flow of mud pump to switch drilling and borehole enlarging state, and the control effect is not ideal. To improve the precision of the borehole enlarging technology while drilling machinery control, a pump-free double channel mechanical borehole enlarging drill bit was developed, which equiped with dual channel to form a complete set of double channel drill pipe and double channel water device. Two sets of individual waterways were designed, annulus water way for cooling bit and carry out rock powder, and center water way is used to control the opening …

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Air-Driven Directional Drilling Technology And Equipment In Soft Coal Seam Of Huainan Mining Area, Tian Hongliang, Chen Jian, Zhang Jie, Cheng Heyu, Dong Ruigang, Du Limeng, Liu Degui, Guan Qiangsheng Oct 2022

Air-Driven Directional Drilling Technology And Equipment In Soft Coal Seam Of Huainan Mining Area, Tian Hongliang, Chen Jian, Zhang Jie, Cheng Heyu, Dong Ruigang, Du Limeng, Liu Degui, Guan Qiangsheng

Coal Geology & Exploration

Aiming at Huainan mining area using bedding directional drilling to eliminate gas outburst in strip coal seams of working face and adjacent roadways, we put forward a technical idea of using pneumatic long directional drilling hole to eliminate gas outburst by one hole. On the basis of the previous pneumatic screw directional drilling technology test, we developed a narrow-body full-section remote directional drilling rig with a width of only 1.1 m, the spindle angle can be stepless adjusted from −90° to 90°, and maximum remote distance of 50 m. The ø73/82 mm screw pneumatic screw drill was optimized, with maximum …

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Influencing Factors Of Increasing The Signal Strength Of The Em-Mwd By Applying Insulation Coating Outside The Casing, Shao Chun, Hu Chuang, Xu Lin, Chen Minghua, Long Xiaoping Oct 2022

Influencing Factors Of Increasing The Signal Strength Of The Em-Mwd By Applying Insulation Coating Outside The Casing, Shao Chun, Hu Chuang, Xu Lin, Chen Minghua, Long Xiaoping

Coal Geology & Exploration

Applying insulation coating outside the casing can reduce the attenuation of Electromagnetic measurement-while-drilling (EM-MWD) signals in low resistivity formations and increase the transmission depth of EM-MWD signals. For the purpose of obtaining the resistivity range of the formation applicable to the insulation coating and the influence of the coating characteristics on the received signal strength, a simulation model is established based on the finite element method, and simulation experiments are carried out on the application effect of the insulation coating applied to the casings of different resistivity formations and the influence regularity of the coating resistivity, thickness and length on …

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