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2020

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Methods To Analyze Likert-Type Data In Educational Technology Research, Li-Ting Chen, Leping Liu Dec 2020

Methods To Analyze Likert-Type Data In Educational Technology Research, Li-Ting Chen, Leping Liu

Journal of Educational Technology Development and Exchange (JETDE)

Likert-type items are commonly used in education and related fields to measure attitudes and opinions. Yet there is no consensus on how to analyze data collected from these items. In this paper, we first synthesized literature on strategies for analyzing Likert-type data and provided computing tools for these strategies. Secondly, to examine the use and analysis of Likert-type data in the field of educational technology, we reviewed 424 articles that were published in the journal Educational Technology Research and Development between 2016 and 2020. Our review showed that about 50% of the articles reported Likert-type data. A total of 139 …

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Experimental And Numerical Investigations On The Hydrodynamic Characteristics Of The Planar Motion Of An Open-Frame Remotely Operated Vehicle, Ying-Fei Zan, Rui-Nan Guo, Li-Hao Yuan, Shi-Peng Wang, Da-Zhong Zhang, Shi-Jing Xu, Zhao-Hui Wu Dec 2020

Experimental And Numerical Investigations On The Hydrodynamic Characteristics Of The Planar Motion Of An Open-Frame Remotely Operated Vehicle, Ying-Fei Zan, Rui-Nan Guo, Li-Hao Yuan, Shi-Peng Wang, Da-Zhong Zhang, Shi-Jing Xu, Zhao-Hui Wu

Journal of Marine Science and Technology–Taiwan

In this study, the longitudinal, sideways, vertical, and sideslip motions of an open-frame remotely operated vehicle (ROV) were experimentally and numerically investigated. The open-frame ROV was designed to be asymmetric in both the longitudinal and vertical directions to achieve special functionalities. A physical ROV model was tested in a towing tank with different velocities and sideslip angles in the horizontal and vertical planes. A numerical simulation was conducted with the same working conditions used in the scaled model tests by using a segregated flow solver based on Reynolds-averaged Navier–Stokes equations. This study investigated the effect of the hydrodynamic forces (moments) …

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An Enhanced Sliding Mode Control Method For Wave Compensation System Of Ship-Mounted Cranes With Roll Motions And Parametric Uncertainties, Hai-Yan Qiang, Si Xie, Zhi-Qiang Xu, You-Gang Sun Dec 2020

An Enhanced Sliding Mode Control Method For Wave Compensation System Of Ship-Mounted Cranes With Roll Motions And Parametric Uncertainties, Hai-Yan Qiang, Si Xie, Zhi-Qiang Xu, You-Gang Sun

Journal of Marine Science and Technology–Taiwan

Ship-mounted cranes are widely used in offshore constructions, resource exploitation and marine salvages, to transfer payloads. Due to serious sea conditions, unexpected motions of the ships caused by the wave will probably pose serious efficiency and security issues. Thus, the wave compensation system has become necessary equipment for the shipmounted crane. But wave-induced motions of the ship, parametric uncertainties and nonlinearities remain challenges for control of wave compensation systems, which needs to be solved urgently. In this paper, the mathematical model of the wave compensation system is established firstly. Then, a sliding mode controller is presented and the stability is …

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Study On Underwater Navigation For Underwater Track Vehicle, Dae-Hyeong Ji, Hyeung-Sik Choi, Sang-Ki Jeong, Hyun-Joon Cho, Ji-Hyeong Lee, Wen-Hsiang Hsieh Dec 2020

Study On Underwater Navigation For Underwater Track Vehicle, Dae-Hyeong Ji, Hyeung-Sik Choi, Sang-Ki Jeong, Hyun-Joon Cho, Ji-Hyeong Lee, Wen-Hsiang Hsieh

Journal of Marine Science and Technology–Taiwan

In this study, an underwater navigation algorithm was developed to apply a navigation system to an underwater track vehicle (UTV). Generally, a Doppler velocity log (DVL) is used to obtain the velocity information of underwater vehicles. However, a DVL cannot be used in a UTV owing to vehicle vibration and limited sensing distance. Hence, dead reckoning navigation is typically used, which results in severe errors in altitude and position values over long periods of operation. To address these problems, in this study, we developed a new underwater navigation system for a UTV using navigation sensors comprising an inertial navigation system, …

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A Study On The Analysis Of Minimum Speed Control Effect Using Queue Model Focused On Busan Port, Sangwon Park, Won-Sik Kang, Young-Soo Park Dec 2020

A Study On The Analysis Of Minimum Speed Control Effect Using Queue Model Focused On Busan Port, Sangwon Park, Won-Sik Kang, Young-Soo Park

Journal of Marine Science and Technology–Taiwan

VTS aims to increase the efficiency of maritime traffic in two ways. The first is a decrease in marine accidents, and the second is an increase in the utilization rate of infrastructure such as waterways and port facilities. This means that, if safety is guaranteed, efficiency must also be considered in the VTS. The purpose of this study is to quantitatively analyze the effects of speed regulation under safe conditions for an efficient use of waterways. A model was developed using a queue approach, and the effect of the waiting time according to the minimum speed proposal was analyzed through …

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More Than A Mask: Stay-At-Home Orders And Religious Freedom, Dorit Rubinstein Reiss, Madeline Thomas Dec 2020

More Than A Mask: Stay-At-Home Orders And Religious Freedom, Dorit Rubinstein Reiss, Madeline Thomas

San Diego Law Review

COVID-19 has changed our legal universe. Many states are responding by issuing stay-at-home orders, and as cases rise, may have to prohibit gatherings again. One issue states and courts have to grapple with is the relationship between stay-at-home orders and religion. Stay-at-home orders that require closing down churches may be challenged as violating the First Amendment’s guarantee of religious freedom. Under our current jurisprudence, these cases may be handled under a highly deferential standard or under strict scrutiny—depending on the specific order in question, as well as on whether the state has a Religious Freedom Restoration Act (RFRA). We recommend, …

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Does Gender Difference Matter In Job Satisfaction? A Case Of Academicians In Karnataka, Shreemathi S. Mayya, Maxie Martis, P. Sureshramana Mayya Dec 2020

Does Gender Difference Matter In Job Satisfaction? A Case Of Academicians In Karnataka, Shreemathi S. Mayya, Maxie Martis, P. Sureshramana Mayya

Open Access archive

Learning organizations are the hubs of knowledge generation and dissemination. Academicians need organizational support to accomplish these time-consuming tasks effectively. The academician, when satisfied with his or her own work, is committed to the organization and demonstrates higher work productivity and work quality. The present study, with a cross-sectional design, was aimed to assess the level of job satisfaction (gender-wise) and its determinants, among academicians, in the institutions of higher education in Karnataka. The study used a validated job satisfaction questionnaire developed by the researchers. The overall job satisfaction was satisfactory and did not differ between the male and female …

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Evolution Of Magnetic-Field-Induced Ordering In The Layered Structure Quantum Heisenberg Triangular-Lattice Antiferromagnet Ba3Cosb2O9, Nathanael Alexander Fortune, Q. Huang, T. Hong, J. Ma, E. S. Choi, S. T. Hannahs, Z. Y. Zhao, X. F. Sun, Y. Takano, H. D. Zhou Dec 2020

Evolution Of Magnetic-Field-Induced Ordering In The Layered Structure Quantum Heisenberg Triangular-Lattice Antiferromagnet Ba3Cosb2O9, Nathanael Alexander Fortune, Q. Huang, T. Hong, J. Ma, E. S. Choi, S. T. Hannahs, Z. Y. Zhao, X. F. Sun, Y. Takano, H. D. Zhou

Physics: Faculty Publications

Quantum fluctuations in the effective spin-1/2 layered structure triangular-lattice quantum Heisenberg antiferromagnet Ba3CoSb2O9 lift the classical degeneracy of the antiferromagnetic ground state in magnetic field, producing a series of novel spin structures for magnetic fields applied within the crystallographic ab plane, including a celebrated collinear ‘up-up-down’ spin ordering with magnetization equal to 1/3 of the saturation magnetization over an extended field range. Theoretically unresolved, however, are the effects of interlayer antferromagnetic coupling and transverse magnetic fields on the ground states of this system. Additional magnetic-field-induced phase transitions are theoretically expected and in some cases have …

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Vision Based Target Recognition For Cage Aquaculture Detection, Chao-Xun Chen, Jih-Gau Juang Dec 2020

Vision Based Target Recognition For Cage Aquaculture Detection, Chao-Xun Chen, Jih-Gau Juang

Journal of Marine Science and Technology–Taiwan

This study applies Unmanned Aerial Vehicle (UAV) to netcage fish-farming. The UAV can fly thru cages along a predefined route. At each cage, the UAV can automatically drop sensors to collect the environment data around the cage. However, low cost commercial or assembled drone might not have precise Global Navigation Satellite System (GNSS). Also, there are many uncertain factors cause Global Positional System (GPS) instability, like weather, location…etc. The main idea of this study is using GPS to guide the drone to approximated location of each cage. Then, apply image recognition to obtain the net-cage and UAV relative position. After …

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Dynamic Behavior Of A Long-Span Cable-Stayed Bridge With Floating Towers After The Sudden Failure Of Tethers And Cables Under Irregular Waves, Minseo Jang, Yunwoo Lee, Seungjun Kim, Young-Jong Kang Dec 2020

Dynamic Behavior Of A Long-Span Cable-Stayed Bridge With Floating Towers After The Sudden Failure Of Tethers And Cables Under Irregular Waves, Minseo Jang, Yunwoo Lee, Seungjun Kim, Young-Jong Kang

Journal of Marine Science and Technology–Taiwan

Cable-supported bridges with floating towers do not require fixed piers at the seabed. Therefore, innovative conceptual models have been continuously developed to overcome the limitations of conventional bridges in deep waters. The main floating tower that supports superstructures using stay cables is balanced by the buoyancy of floaters moored by tethers. The applicability of floating bridges should be verified by evaluating the overall stability considering the tether design. Here, various cases of the sudden failure of tethers and stay cables under the environmental conditions of a 100-year return period are simulated in a time-domain. The floating cable-stayed bridges are subjected …

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Internal Force Evaluation Of A Submerged Floating Pipeline Under Irregular Waves, Deokhee Won, Jihye Seo, Jong Sup Park, Seungjun Kim Dec 2020

Internal Force Evaluation Of A Submerged Floating Pipeline Under Irregular Waves, Deokhee Won, Jihye Seo, Jong Sup Park, Seungjun Kim

Journal of Marine Science and Technology–Taiwan

Generally, submarine pipelines are laid on the seabed to transport water, oil, natural gas, and electricity to the land using submarine cables. However, they are not suitable for all seafloor conditions. There are environmental concerns such as deep seas, irregular seabed features, soft soils, transported materials and so on. To overcome these challenges, a submerged floating pipeline (SFP) concept was proposed. To stay in the middle of the water, the SFP has buoyant modules as floating devices. It is unrestricted under environments such as uneven seabeds, and deep waters, and is suspended to avoid interrupting passing vessels. This SFP model …

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High Rank Coal Structure And Log Interpretation Method Of Fracture Pressure In Shouyang Block, Li Songlin, Li Zhongcheng, Wang Lina, Duan Jing, Xiang Nian Dec 2020

High Rank Coal Structure And Log Interpretation Method Of Fracture Pressure In Shouyang Block, Li Songlin, Li Zhongcheng, Wang Lina, Duan Jing, Xiang Nian

Coal Geology & Exploration

In order to accurately describe the distribution of surface subsidence basin, and based on the power exponential function model and the subsidence features, the surface subsidence basin model of long-wall working face along strike with gently inclined coal seam was established concerned the combination of theoretical analysis and numerical simulation method. The influencing factors of model parameters and the changing patterns of parameters were analyzed, and the applicability and the predicting accuracy of the model were verified. The results showed that parameter n reflected the range of the bottom size of the sinking basin, which was mainly related to the …

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Biogas Production Of Lignite And Variation Characteristics Of Cations In Liquid Phase System, Zhao Han, He Huan, Wang Jiangze, Song Yanli, Niu Jianglu, Chen Linyong, Guo Xin, Liu Jian, Guan Jiadong, Yuan Xuefang Dec 2020

Biogas Production Of Lignite And Variation Characteristics Of Cations In Liquid Phase System, Zhao Han, He Huan, Wang Jiangze, Song Yanli, Niu Jianglu, Chen Linyong, Guo Xin, Liu Jian, Guan Jiadong, Yuan Xuefang

Coal Geology & Exploration

Liupan Shan lies between the Tibetan plateau and Ordos block and has been under the remote effect of the northeastward extension of the Tibetan plateau. The former research about the uplift of Liupan Shan mainly focused on the petrology, structural deformation or tectonic evolution study from the Cretaceous to early period of Cenozoic. However, the Late Pleistocene geological study closely connected with the human activities was rarely mentioned. In this study, we carried out systematic sedimentary research in the Qingshuihe basin adjacent to the Liupan Shan tectonic belt, re-determine the sedimentary sequence at first, then reverse the uplift history of …

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Pattern And Effect Of The High Density 3d Seismic Exploration In Coal Mining Districts, Jin Xueliang, Wang Qi Dec 2020

Pattern And Effect Of The High Density 3d Seismic Exploration In Coal Mining Districts, Jin Xueliang, Wang Qi

Coal Geology & Exploration

Graphene is an emerging carbon nanomaterial in the 21st century, has excellent properties and shows great application potential in many fields. Coal is the most abundant and the cheapest carbon source with unique structure and material composition. The application of coal in the development and the application of new carbonaceous materials such as graphene and their composites is a work worthy of further exploration. The development of coal-based graphene can both promote the clean utilization of coal and enhance the added value of coal resources. In this paper, the research developments in coal structure, the mechanism of coal graphitization, as …

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Summary Of High Density 3d Seismic Exploration In The Mining Districts Of Coal Mines In Shanxi Province, Hou Zeming, Yang Deyi Dec 2020

Summary Of High Density 3d Seismic Exploration In The Mining Districts Of Coal Mines In Shanxi Province, Hou Zeming, Yang Deyi

Coal Geology & Exploration

Based on the analysis of geological characteristics of the study area, it is considered that the geological conditions of H2S occurrence are the capping effect of dense surrounding rock on the roof and floor, the water-conducting fractured zone is unable to guide the overlying aquifer, and the low degree of coal metamorphism is not conducive to H2S adsorption, resulting in maximum H2S concentration of about 0.001 4% in the main mined coal seam 4 during the construction of Yadian mine at the north of Binchang mining area. Through the analysis of sulfur distribution, sulfate …

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Analysis Of Channel Imaging Effect Of High Density And Conventional Observation System, Zhang Xianxu Dec 2020

Analysis Of Channel Imaging Effect Of High Density And Conventional Observation System, Zhang Xianxu

Coal Geology & Exploration

Aiming at the problems of uncontrollable trajectory, shallow borehole depth and poor gas extraction effect in gas treatment drilling of broken soft coal seam in Qinglong coal mine, the regional progressive gas extraction technology in broken soft coal seam based on compressed-air directional drilling was proposed, on the basis of analyzing the technical bottleneck of existing gas extraction borehole with rotary drilling. The principle and advantage of the technology was expounded, the technology of directional drilling by compressed-air, the technology of long distance in-seam drilling, and the technology of compound slag discharge by double power were integrated. The field test …

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High Density 3d Seismic Data-Driven Comprehensive Interpretation Method Of Magmatic Intrusion Zones In Coal Seams And Its Application, Shan Rui, Zhang Guangzhong, Wang Qianyao, Yang Guangming Dec 2020

High Density 3d Seismic Data-Driven Comprehensive Interpretation Method Of Magmatic Intrusion Zones In Coal Seams And Its Application, Shan Rui, Zhang Guangzhong, Wang Qianyao, Yang Guangming

Coal Geology & Exploration

Ordovician limestone karst water is the main threatening water source for mining activities in Baode coal mine, and it is one of the main water supply sources. Ordovician limestone karst water samples were systematically collected in Baode coal mine, and the methods of correlation analysis, ion proportional coefficient, saturation index inversion simulation and Chlor-Alkali index were chosen to analyze the hydrochemical characteristics and its formation mechanism. The results showed that the water quality types of Ordovician limestone water changed from runoff zone to stagnant zone in a trend of HCO3-Na(Na·Ca)→HCO3·Cl-Na·Ca(Ca·Mg)→Cl-Na(Na·Ca). The mass concentration of each ion …

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Information Needs And Use Of Non-Academic Staff In University Of Africa, Bayelsa State, Nigeria, Kolawole Ogunbodede, Smart E. Ambrose Mr. Dec 2020

Information Needs And Use Of Non-Academic Staff In University Of Africa, Bayelsa State, Nigeria, Kolawole Ogunbodede, Smart E. Ambrose Mr.

Library Philosophy and Practice (e-journal)

The paper examined the information needs and use of non-academic staff in University of Africa, Bayelsa State, Nigeria. The researchers adopted descriptive survey design. The population of the study comprised of 100 non-academic staff out of which 57 were randomly selected. Four (4) research questions guided this study. Data was collected using the questionnaire. Data was analyzed with descriptive statistics such as frequency count and simple percentage. The findings revealed that non-academic staff had diverse information needs based on their work roles and they consult multiple information sources to meet their information needs. Regarding the purpose for using information, it …

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A Bibliometric Survey On Ultra Wideband Multiple Input Multiple Output Antenna With Improved Isolation, Laxmikant K. Shevada, Hema D. Raut, Rajeshwari R. Malekar, Amruta S. Dixit, Sumit Kumar Dec 2020

A Bibliometric Survey On Ultra Wideband Multiple Input Multiple Output Antenna With Improved Isolation, Laxmikant K. Shevada, Hema D. Raut, Rajeshwari R. Malekar, Amruta S. Dixit, Sumit Kumar

Library Philosophy and Practice (e-journal)

Ultra wideband (UWB) technology remains a viable choice for very high speed data communication in future applications involving large bandwidth. For boosting the data communication efficiency and to mitigate the multipath fading issue faced by UWB system with existing narrowband systems, Multiple Input Multiple Output (MIMO) antenna system is used along with UWB. Mutual coupling which must be smaller in value plays a vital role in deciding the efficiency of MIMO antenna and hence it becomes as important aspect. The mutual coupling reduction techniques of various UWB MIMO antennas are surveyed in this bibliometric paper. The bibliometric survey aims to …

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Application Of High-Precision 3d Seismic Exploration Technology In Huainan Mining Area, Liu Jun, Zhao Wei, Han Biwu Dec 2020

Application Of High-Precision 3d Seismic Exploration Technology In Huainan Mining Area, Liu Jun, Zhao Wei, Han Biwu

Coal Geology & Exploration

In order to deeply analyze the indication of oil shale development characteristics on paleoenvironments and provide theoretical guidance for oil shale resource evaluation, the organic geochemistry and elemental geochemistry characteristics of the Neogene Zhangcun Formation oil shale in the central part of the Qinshui basin were analyzed by Rock-Eval and TOC and the paleoclimate and paleogeographic environments of the depositional period were discussed as well. The results show that the oil shale of Zhangcun Formation has the low oil content which Tar=4.15%, higher hydrocarbon potential, kerogen is of sapropel type(I1), which has relatively shallow burial depth. The element …

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Discussion On Parameters Of High Density 3d Seismic Exploration Acquisition In Coal Mining Districts, Cheng Jianyuan, Wang Qianyao, Zhu Shujie Dec 2020

Discussion On Parameters Of High Density 3d Seismic Exploration Acquisition In Coal Mining Districts, Cheng Jianyuan, Wang Qianyao, Zhu Shujie

Coal Geology & Exploration

In order to improve the light tar and gas yield, the yield distribution and composition characteristics of pyrolysis products of bituminous coal from Shaanxi Hongliulin in the nitrogen atmosphere and weak oxygen atmosphere were studied in a fixed bed reactor. The results showed that the yield of char and tar were reduced under the weak oxygen atmosphere, and the yield of CO and CO2 increased significantly, leading to the increase of total gas yield. Due to the oxidation combustion reaction, the yield of H2, CH4 and C2-C3 gradually decreased with the increase of …

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X-Shaped Real Fracture Channels-Based Simulation Of Coal Seam Gas Seepage, Su Zhengrui, Wei Shanyang Dec 2020

X-Shaped Real Fracture Channels-Based Simulation Of Coal Seam Gas Seepage, Su Zhengrui, Wei Shanyang

Coal Geology & Exploration

The filling expansion mechanism and control measures of high concentration slurry in goaf is one of the difficult problems to be solved in the filling treatment of cavity goaf. Based on this, combined with the high concentration slurry transportation and rheological theory, a high concentration slurry filling process model was constructed to reveal its expansion mechanism, the dynamic and resistance calculation methods of filling expansion process were studied, the main influencing factors and control methods of filling accumulation body morphology were determined, and the theoretical results were verified by outdoor filling test.The results show that the the relative error between …

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The Application Of Ovt Domain Processing Technology In Deep Cbm Exploration In Qinshui Basin, Tian Zhongbin, Li Juan, Shen Youyi, Feng Ajian, Yang Xiaodong Dec 2020

The Application Of Ovt Domain Processing Technology In Deep Cbm Exploration In Qinshui Basin, Tian Zhongbin, Li Juan, Shen Youyi, Feng Ajian, Yang Xiaodong

Coal Geology & Exploration

The high concentration slurry is poured into the goaf to form filled piers. The bearing capacity of the piers to the superstructure are affected by the overlap size. In order to grasp the influence of the overlap size on the bearing capacity of the overlying rock layer, high concentration slurry was prepared which selected cement as the cementing material, standard sand as the aggregate. 3D printing technology was used to make the mold to produce the overlapped round table samples. The uniaxial compression test was carried out. Test results show that, when the top area and height of each single …

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Pulverized Coal-Controlling Method Based On Supermolecular Film In Cbm Well, Wu Ying, Li Xiaonan, Liu Zixiong, Liu Rumin Dec 2020

Pulverized Coal-Controlling Method Based On Supermolecular Film In Cbm Well, Wu Ying, Li Xiaonan, Liu Zixiong, Liu Rumin

Coal Geology & Exploration

Correctly understanding the micro-scale fracture characteristics of the Lower Cambrian shale and the evolution law of acoustic emission signals are of great reference value in the study of shale mechanical characteristics, fracture mechanism and shale gas development and utilization. In this paper, based on digital image processing technology, the non-uniform characterization of quartz-filled shale is carried out, and a numerical model is established using the real rock fracture analysis system RFPA2D-DIP to simulate the failure process of shale under different confining pressures. The test results show that under the micro-scale structure, the shale failure mode can be roughly …

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Analysis On The Cbm Extraction Effect Of The Horizontal Wells In The Coal Seam Roof In Luling Coal Mine In Huaibei, Fang Liangcai, Li Guihong, Li Dandan, Li Haozhe, Liu Jia Dec 2020

Analysis On The Cbm Extraction Effect Of The Horizontal Wells In The Coal Seam Roof In Luling Coal Mine In Huaibei, Fang Liangcai, Li Guihong, Li Dandan, Li Haozhe, Liu Jia

Coal Geology & Exploration

Aiming at the scientific evaluation of coaxial casing heat transfer of geothermal resources with medium burial depth(1 500-4 000 m), a rock-water coupled heat transfer model of a vertical single well was built based on the simulation platform of COMSOL Multiphysics software. Taking the stratigraphic and geothermal characteristics of Xi'an area as the simulation background, the heat transfer capacity of single well(3 500 m)casing under two different geothermal gradients(0.027℃/m and 0.030℃/m) and four flow velocities(0.25, 0.50, 0.75, 1.00 m/s) was calculated and analyzed. Meanwhile, the numerical models of group wells with five kinds of well spacing were established, and the …

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Mechanism Of Aggregate Start-Up Process And Coupling Of Two-Phase Flow In Hydrodynamic Roadway, Mou Lin Dec 2020

Mechanism Of Aggregate Start-Up Process And Coupling Of Two-Phase Flow In Hydrodynamic Roadway, Mou Lin

Coal Geology & Exploration

Adding heat-conducting filler to the cement of the geothermal well could significantly improve the thermal conductivity of the cement stone and enhance the heat extraction effect of the geothermal well. In this study, on the basis of summarizing the heat conduction path theory and concept of high packing density, the effects of different filler types, particle sizes and dosages on the thermal conductivity of cementing cement were investigated through experiments. The test results showed that graphite had the best effect on improving the thermal conductivity of cement stone compared to other types of filler; the larger the graphite particle size, …

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Hydrogeological Characteristics And Danger-Solving Mining Of Jurassic Baotashan Sandstone—A Case Study In New Shanghai No.1 Coal Mine, Lyu Yuguang, Liu Baokai, Zhao Baofeng, Lyu Wenqing, Han Gang, Wang Yongbao Dec 2020

Hydrogeological Characteristics And Danger-Solving Mining Of Jurassic Baotashan Sandstone—A Case Study In New Shanghai No.1 Coal Mine, Lyu Yuguang, Liu Baokai, Zhao Baofeng, Lyu Wenqing, Han Gang, Wang Yongbao

Coal Geology & Exploration

In order to make up for the deficiency of the regional monitoring of the traditional gas drainage monitoring system, this paper proposes to build a borehole gas drainage monitoring system with borehole as the monitoring unit, which can dynamically grasp the drainage effect of each borehole in the process of gas drainage in real time, change the large area regional measurement into the measurement of each borehole in the region, and realize the fine monitoring of gas drainage. According to the requirements of borehole gas drainage monitoring system, combined with the characteristics of gas drainage parameters at the borehole orifice, …

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Construction And Transformation Technology Of Three-Dimensional Fine Model Of Mine Water Diversion Structure, Fan Juan, Hou Enke, Jin Dewu, Qiao Wei, Nan Shenghui Dec 2020

Construction And Transformation Technology Of Three-Dimensional Fine Model Of Mine Water Diversion Structure, Fan Juan, Hou Enke, Jin Dewu, Qiao Wei, Nan Shenghui

Coal Geology & Exploration

The development degree of natural fractures is the main factor affecting coalbed methane productivity. In order to accurately obtain the distribution position of the natural fractures in the a coalbed methane field in the southern Qinshui basin, 7 refracturing wells in the area were adopted by surface microseismic vector scanning to monitor the natural fractures. A certain amount of three-component geophones were deployed around the fracturing well to collect microseismic events in the surrounding reservoir during fracturing, and after Semblance superposition, the fracture energy slices at different times in the monitoring area were obtained to explain the natural fractures in …

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Spatial Relationship Between Temperature Field, Hydrothermal Alteration And Main Faults In Shiquan County, Ankang, Xu Li, Ma Runyong, Pan Aifang, Zhang Fan Dec 2020

Spatial Relationship Between Temperature Field, Hydrothermal Alteration And Main Faults In Shiquan County, Ankang, Xu Li, Ma Runyong, Pan Aifang, Zhang Fan

Coal Geology & Exploration

Wide-band, high-power and short-residual acoustic wave sources are the key technology for high-resolution detection of large-scale complex structures, in order to solve the contradiction between detection distance and resolution, a new acoustic wave detection instrument is developed by using the acoustic transmitter made of giant magnetostrictive material(GMM) as the source. The focal center frequency is 5 kHz, and the excitation voltage is 300-600 V, it has the characteristics of large radiated sound power, short residual vibration(3.5 cycles) and frequency band width(1-3 kHz), which solves the problem of the high resolution acoustic wave detection. Its greatest advantage is that the acoustic …

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Research On The Fracture Mechanics Model Of Deep Hole Pre-Splitting For Forced Caving, Li Jinhua, Chen Wenxiao, Su Peili, Duan Dong, Song Yongjun Dec 2020

Research On The Fracture Mechanics Model Of Deep Hole Pre-Splitting For Forced Caving, Li Jinhua, Chen Wenxiao, Su Peili, Duan Dong, Song Yongjun

Coal Geology & Exploration

Tight radius drilling technology based on high pressure water jet is an important technical means to realize low-cost and efficient development of oil and gas resources. According to the research and application of tight radius drilling technology based on high pressure water jet, the equipment buildup, drilling theory, technical process and application effect of three tight radius drilling technologies and equipments(i.e., forging milling and reaming hydraulic type, forging milling and reaming jet thrust type and casing window type) are summarized systematically, and the advantages, disadvantages and adaptability of different technologies are included. From the point of view of increasing production …

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