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2022

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Articles 4171 - 4200 of 9379

Full-Text Articles in Engineering

Murals Super-Resolution Reconstruction With The Stable Enhanced Generative Adversarial Network, Jianfang Cao, Yiming Jia, Minmin Yan, Xiaodong Tian May 2022

Murals Super-Resolution Reconstruction With The Stable Enhanced Generative Adversarial Network, Jianfang Cao, Yiming Jia, Minmin Yan, Xiaodong Tian

Journal of System Simulation

Abstract: Aiming at the problems of low resolution and unclear texture details of ancient murals, which led to insufficient viewing of murals and low research value, a stable enhanced super-resolution generative adversarial networks (SESRGAN) reconstruction algorithm is proposed. Based on the generative adversarial network, the generative network uses dense residual blocks to extract mural features, and uses the visual geometry group (VGG) network as the basic framework of the discriminating network to determine the authenticity of the input mural, and introduces perception loss, content loss and penalty loss to jointly optimize the model. Experimental results show that, compared with other …

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Design Of Variable Stiffness Energy Storage Walking Assist Hip Exoskeleton And Simulation Of Assistance Effect, Bingshan Hu, Ke Cheng, Sheng Lu, Hongliu Yu May 2022

Design Of Variable Stiffness Energy Storage Walking Assist Hip Exoskeleton And Simulation Of Assistance Effect, Bingshan Hu, Ke Cheng, Sheng Lu, Hongliu Yu

Journal of System Simulation

Abstract: Passive energy storage walking assist exoskeleton makes full use of the human’s own energy, reducing energy consumption when walking. Aiming at the present passive energy storage walking assist exoskeleton adopts fixed stiffness joint, a passive variable stiffness energy storage walking assist hip exoskeleton is designed, on the base of joint energy flow characteristics in the process of people walking and the change of stiffness characteristics. The human-exoskeletons coupling model is established, and the optimal stiffness that minimizes the power consumption of the human body walking on a flat surface, as well as the total metabolism and the main thigh …

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Robot Path Planning Based On Bidirectional Aggregation Ant Colony Optimization, Xiangyang Deng, Limin Zhang, Wei Fang, Miao Tang May 2022

Robot Path Planning Based On Bidirectional Aggregation Ant Colony Optimization, Xiangyang Deng, Limin Zhang, Wei Fang, Miao Tang

Journal of System Simulation

Abstract: Path planning is a key theoretical issue of the autonomous mobile robot technology. This paper utilizes an improved grid method to establish environment model, which involves a new priori advantage azimuth structure that includes two parts of the primary dominant grid cell and the subprime grid cell. It improves the pheromone mark ant colony optimization algorithm by putting forward a novel pheromone update strategy based on secondary path cognitive method, which is called bidirectional guidance strategies. It repeats an alternation of the starting point and the target point in each new round of iteration. The experimental results show that …

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Research On Parametric Modeling And Deformation Method Of Human Muscle, Na Ni, Kunjin He, Xincheng Zhu, Zhengming Chen May 2022

Research On Parametric Modeling And Deformation Method Of Human Muscle, Na Ni, Kunjin He, Xincheng Zhu, Zhengming Chen

Journal of System Simulation

Abstract: Due to the volume preserving constraint of human muscle in the deformation process, and the lack of three-dimensional multi-angle representation of muscle motion, a parametric modeling and deformation method of human muscle is proposed. Based on MRI (magnetic resonance imaging) data, the external contour line is extracted from the slice image generated by MRI data to construct a three-dimensional muscle model; muscle features are defined hierarchically, and the mapping relationship between semantic parameters is established to realize the volume preserving deformation of muscle; by establishing a vector-valued dynamic fourth-order differential equation, the feature curve dynamically simulates the process …

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State Prediction Of Poverty Alleviation Objects Based On Hmm And Multidimensional Data, Jun He, Sunyan Hong, Yifang Zhou, Shikai Shen, Muquan Zou May 2022

State Prediction Of Poverty Alleviation Objects Based On Hmm And Multidimensional Data, Jun He, Sunyan Hong, Yifang Zhou, Shikai Shen, Muquan Zou

Journal of System Simulation

Abstract: In order to solve the problems of inaccurate prediction of poverty, poverty reduction and poverty returen, and the difficulty in identifying the key factors affecting the state transition, 8 key features and 22 observed states are extracted from the poverty reduction basic data and multi-industry data. The relationship between observed state and implied state is constructed, and the hidden markov model (HMM) of poverty alleviation is established. Data of a deep poverty county for three consecutive years are used as samples for parameter training, test experiment and result verification. The results show that the method has a strong …

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Simulation Of Navigation Process Based On Nonlinear Observer, Zhiwei Wang, Jizong Hu, Fengjie Wang, Jie Huang May 2022

Simulation Of Navigation Process Based On Nonlinear Observer, Zhiwei Wang, Jizong Hu, Fengjie Wang, Jie Huang

Journal of System Simulation

Abstract: In order to solve the problem that the scope of using thetraditional observers is limited by assumptions, in the process of establishing the observer, a parameter projection relationship is designed and added to the observer to keep it under the condition of not being constrained by the assumptions. It is semi-globally stable, and the estimation process is more direct, which makes the parameter estimation process under nonlinear conditions converge faster. The simulation results show that the computational complexity of the nonlinear observer is reduced by nearly 80% compared with the multiplicative extended Kalman filter. The experimental results show that …

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A Visual Analytics Of Urban Traffic Events Using Social Media Data, Xiangping Wu, Lijun Ping, Dongshi Xu May 2022

A Visual Analytics Of Urban Traffic Events Using Social Media Data, Xiangping Wu, Lijun Ping, Dongshi Xu

Journal of System Simulation

Abstract: Traffic text data in social media can supplement traffic flow information, for which a visual analysis method for traffic events is proposed. A text processing model is designed to process the social media data and extract the description information of traffic event. The vector representation of road node attributes is learned based on graph embedding algorithm, and a road similarity model is estbalished. A prediction model of the traffic event is built based on the road similarity and the kernel density model. An interactive visual analysis system is designed to carry out visual analysis. Though traffic …

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Research On Visual Inspection Algorithm Of Crimping Appearance Defects For Wiring Harness Terminals, Bingan Yuan, Mingen Zhong, Jingxin Ni May 2022

Research On Visual Inspection Algorithm Of Crimping Appearance Defects For Wiring Harness Terminals, Bingan Yuan, Mingen Zhong, Jingxin Ni

Journal of System Simulation

Abstract: Aiming at the low efficiency and high missing rate of wiring harness terminals, an image detection method based on machine vision is proposed. The characteristic parameters of five typical defects in three main parts of wiring harness terminals are analyzed and defined. Tthe algorithms of extracting positioning datum, segmenting inspected-parts adaptively, extracting the defect features and calculating the characteristic parameters are designed respectively, and the defects criterions are given. The experimental results show that the algorithms are suitable for single defect and multi-class defects, both the miss detection rate and the false positiveness rate are low. The accuracy and …

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Phased Array Radar Doa Estimation Simulation System Designed With Interactive Control, Fan Yu, Dongqi Luo, Binqiang Si, Jihong Zhu May 2022

Phased Array Radar Doa Estimation Simulation System Designed With Interactive Control, Fan Yu, Dongqi Luo, Binqiang Si, Jihong Zhu

Journal of System Simulation

Abstract: For the problem of simulation, evaluation and verification of phased array radar the direction of arrival (DOA) estimation of phased array radar, the modeling and evaluation of phased array radar DOA estimation is discussed. A real-time simulation system based on interactive control is designed. The simulation system can be used to model and simulate the interactive target & environment, phased array and target detection efficiency evaluation model. The signal generation, free space propagation, echo signal acquisition, signal processing and other processes can be simulated during the detection of real-time flying target, and the effect of DOA estimation can be …

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Research On Immersive Virtual Reality Interactive System For Flow Visualization, Shijian Xu, Dan Zhao, Chengyu Su, Fupan Wang, Xiaorong Zhang, Fang Wang, Yadong Wu May 2022

Research On Immersive Virtual Reality Interactive System For Flow Visualization, Shijian Xu, Dan Zhao, Chengyu Su, Fupan Wang, Xiaorong Zhang, Fang Wang, Yadong Wu

Journal of System Simulation

Abstract: Aiming at the problem of low interaction efficiency due to the lack of depth information in the current desktop flow visualization application based on the two-dimensional display interaction environment, virtual reality technology is introduced to design and implement an immersive flow visualization system with diversified interaction methods. Based on the gaze and gesture interaction technology, the system designs and implements gesture-based navigation methods and three-dimensional interactive widgets based on user requirements, as well as immersive interactive panels based on user gaze and gestures. We designed and implemented an immersive interactive management method based on visual scenes and a visual …

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Feral Horses And Bison At Theodore Roosevelt National Park (North Dakota, United States) Exhibit Shifts In Behaviors During Drone Flights, Javier Lenzi, Christopher J. Felege, Robert Newman, Blake Mccann, Susan N. Ellis-Felege May 2022

Feral Horses And Bison At Theodore Roosevelt National Park (North Dakota, United States) Exhibit Shifts In Behaviors During Drone Flights, Javier Lenzi, Christopher J. Felege, Robert Newman, Blake Mccann, Susan N. Ellis-Felege

Biology Faculty Publications

Drone use has been rapidly increasing in protected areas in North America, and potential impacts on terrestrial megafauna have been largely unstudied. We evaluated behavioral responses to drones on two terrestrial charismatic species, feral horse (Equus caballus) and bison (Bison bison), at Theodore Roosevelt National Park (North Dakota, United States) in 2018. Using a Trimble UX5 fixed-wing drone, we performed two flights at 120 m above ground level (AGL), one for each species, and recorded video footage of their behaviors prior to, during, and after the flight. Video footage was analyzed in periods of 10 s intervals, and the occurrence …

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

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

Coal Geology & Exploration

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

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

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

Coal Geology & Exploration

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

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

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

Coal Geology & Exploration

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

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

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

Coal Geology & Exploration

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

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

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

Coal Geology & Exploration

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

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

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

Coal Geology & Exploration

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

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

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

Coal Geology & Exploration

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

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

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

Coal Geology & Exploration

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

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

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

Coal Geology & Exploration

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

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

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

Coal Geology & Exploration

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

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

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

Coal Geology & Exploration

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

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Geological Structure Detection With Tunnel Transient Electromagnetic Kirchhoff 2d Migration Imaging, Qi Zhipeng, Guo Jianlei, Sun Naiquan, Li Xiu, Fan Yanan May 2022

Geological Structure Detection With Tunnel Transient Electromagnetic Kirchhoff 2d Migration Imaging, Qi Zhipeng, Guo Jianlei, Sun Naiquan, Li Xiu, Fan Yanan

Coal Geology & Exploration

The green construction of tunnel requires not only predicting disaster anomalies such as water inrush and mud inrush in front of tunnel face, but also identifying geological structure to support disaster warning and prevention. The traditional transient electromagnetic interpretation method can only provide resistivity information, which not meet the requirements of tunnel geological disaster management. Therefore, virtual wavefield imaging technology is introduced into the tunnel detection to achieve comprehensive interpretation of the electrical information and structures of disaster anomalies. Firstly, transient electromagnetic data is transformed into virtual wave field. Then, the resistivity imaging method was used to calculate the resistivity …

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Degradation Mechanisms Of Zinc-Air Batteries Used In Hearing Aid, Kelly Hunt, Mallorty Bates, Gerard Klint Simon, Tarun Goswami May 2022

Degradation Mechanisms Of Zinc-Air Batteries Used In Hearing Aid, Kelly Hunt, Mallorty Bates, Gerard Klint Simon, Tarun Goswami

Biomedical, Industrial & Human Factors Engineering Faculty Publications

Hearing aid devices are powered by the oxidation of zinc that occurs within zinc-air batteries. Zinc-air batteries have an average discharge time of 7 days. Therefore, hearing-aid devices need frequent battery replacement. In this paper, degradation mechanisms of zinc-air batteries investigated where a competition mechanism between zinc passivation and dendritic formation dictates the battery life. This research included exposure time from none to 9 days and to document dendritic growth with time. Scanning electron microscope images were taken to quantify the damage growth as well energy dispersive X-ray tests were conducted to comment on the composition changes. The results confirmed …

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

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

Coal Geology & Exploration

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

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

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

Coal Geology & Exploration

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

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

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

Coal Geology & Exploration

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

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Novel Compact Mimo Antenna Array Structures For 5g, Wi-Fi 6 And Vehicular Applications, Sulaiman Tariq May 2022

Novel Compact Mimo Antenna Array Structures For 5g, Wi-Fi 6 And Vehicular Applications, Sulaiman Tariq

Theses and Dissertations

Due to the fast development of wireless communication applications, the study of Multiple Input Multiple Output (MIMO) communication systems has lately gained comprehensive research interests since it can significantly increase the channel capacity and link reliability without sacrificing bandwidth and/or power transmitted. However, the user equipment is constantly shrinking in size to support more applications and satisfy aesthetic needs, which increases the need for more compact, high-performance antenna array designs. Many techniques are being constantly developed to combat the effects of mutual coupling that arise with the miniaturization of MIMO arrays. This dissertation focuses on designing, testing, and evaluating new …

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Virucidal N95 Respirator Face Masks Via Ultrathin Surface-Grafted Quaternary Ammonium Polymer Coatings, Mirco Sorci, Tanner D. Fink, Vaishali Sharma, Sneha Singh, Ruiwen Chen, Brigitte L. Arduini, Katharine Dovidenko, Caryn L. Heldt, Edmund F. Palermo, R Helen Zha May 2022

Virucidal N95 Respirator Face Masks Via Ultrathin Surface-Grafted Quaternary Ammonium Polymer Coatings, Mirco Sorci, Tanner D. Fink, Vaishali Sharma, Sneha Singh, Ruiwen Chen, Brigitte L. Arduini, Katharine Dovidenko, Caryn L. Heldt, Edmund F. Palermo, R Helen Zha

Michigan Tech Publications, Part 1

N95 respirator face masks serve as effective physical barriers against airborne virus transmission, especially in a hospital setting. However, conventional filtration materials, such as nonwoven polypropylene fibers, have no inherent virucidal activity, and thus, the risk of surface contamination increases with wear time. The ability of face masks to protect against infection can be likely improved by incorporating components that deactivate viruses on contact. We present a facile method for covalently attaching antiviral quaternary ammonium polymers to the fiber surfaces of nonwoven polypropylene fabrics that are commonly used as filtration materials in N95 respirators via ultraviolet (UV)-initiated grafting of biocidal …

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

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

Coal Geology & Exploration

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

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