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2019

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State V. Rask Appellant's Brief Dckt. 47185 Dec 2019

State V. Rask Appellant's Brief Dckt. 47185

Not Reported

No abstract provided.

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Cognitively Normal Women With Alzheimer’S Disease Proteinopathy Show Relative Preservation Of Memory But Not Of Hippocampal Volume, Jessica Z.K. Caldwell, Jeffrey L. Cummings, Sarah J. Banks, Sebastian Palmqvist, Oskar Hansson Dec 2019

Cognitively Normal Women With Alzheimer’S Disease Proteinopathy Show Relative Preservation Of Memory But Not Of Hippocampal Volume, Jessica Z.K. Caldwell, Jeffrey L. Cummings, Sarah J. Banks, Sebastian Palmqvist, Oskar Hansson

School of Medicine Faculty Research

Background: We examined interactive effects of sex, diagnosis, and cerebrospinal fluid (CSF) amyloid beta/phosphorylated tau ratio (Aβ/P-tau) on verbal memory and hippocampal volumes. Methods: We assessed 682 participants (350 women) from BioFINDER (250 cognitively normal [CN]; and 432 symptomatic: 186 subjective cognitive decline [SCD], 246 mild cognitive impairment [MCI]). General linear models evaluated effects of Alzheimer’s disease (AD) proteinopathy (CSF Aß/p-tau ratio), diagnosis, and sex on verbal memory (ADAS-cog 10-word recall), semantic fluency (animal naming fluency), visuospatial skills (cube copy), processing speed/attention functions (Symbol Digit Modalities Test and Trail Making Part A), and hippocampal volumes. Results: Amyloid-positive (Aβ/P-tau+) CN women …

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Sibylline Oracles 4–5, Olivia Stewart Lester Dec 2019

Sibylline Oracles 4–5, Olivia Stewart Lester

Theology: Faculty Publications and Other Works

The T&T Clark Encyclopedia of Second Temple Judaism provides a comprehensive reference resource of over 600 scholarly articles aimed at those studying Judaism in the Second Temple Period, and the numerous texts and artefacts related to it.

The work is split into four parts across two volumes.

Part One locates the discipline in relation to other relevant fields (for example the Hebrew Bible, Rabbinics, Christian Origins) and provides an orientation to the discipline's distinctive nomenclatures and debates. The history of research in the area is also presented in full.

Part Two presents an overview of respective contexts of the discipline …

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Perceptions Of Health And Safety Among Workers In The Automotive Repair Industry In Dubai (United Arab Emirates): A Cross-Sectional Exploratory Study, Mona El Kouatly Kambris, Sarah Khan, Shatha Nabil Al Falasi Dec 2019

Perceptions Of Health And Safety Among Workers In The Automotive Repair Industry In Dubai (United Arab Emirates): A Cross-Sectional Exploratory Study, Mona El Kouatly Kambris, Sarah Khan, Shatha Nabil Al Falasi

All Works

Background: Protection of workers against work-related injuries and illnesses is a growing public health concern. The increasing number of expatriate workers in Dubai has highlighted the need for greater emphasis on occupational health and safety, particularly since unintentional injuries were reported to be the second most common cause of death in the United Arab Emirates. Objectives: This cross-sectional study explores safety practices and health perceptions of workers in the automotive repair industry, in the light of the Health Belief Model. Materials and Methods: The study included 35 automotive repair industry workers, selected by convenience sampling from an automotive workshop in …

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Incidence Of Breast Cancer In Women With Breast Cyst, Ayad Yas Khudair Dec 2019

Incidence Of Breast Cancer In Women With Breast Cyst, Ayad Yas Khudair

Muthanna Medical Journal

This study was aimed to determine the incidence of breast cancer in women diagnosed with breast cyst by ultrasonography. A study was carried out on 124 women aged from 25–70 year suffering from breast cyst, presented between Feb 2016 and Oct 2019. Diagnosis was obtained by case history, clinical signs and physical examination of all women and established with ultrasonography with high-frequency (7.5-10-MHz frequency) to determine the breast carcinoma in breast cyst. Cysts were classified as simple cysts, complicated cysts or complex cyst. Highest percent of breast cyst was recorded in ages ranged from 35-50 year (84.6%). The size of …

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This Is My Neighborhood: An Exploration Of Culturally Relevant Agency To Support High School Latinx Students In An Urban Career Academy, Edward C. Fletcher Jr., Victor M. Hernandez-Gantes, Chrystal Smith Dec 2019

This Is My Neighborhood: An Exploration Of Culturally Relevant Agency To Support High School Latinx Students In An Urban Career Academy, Edward C. Fletcher Jr., Victor M. Hernandez-Gantes, Chrystal Smith

The Qualitative Report

The purpose of this study was to explore the perspectives and strategies internal and external stakeholders used to support students in a career academy serving a predominately Latinx community. Within this case study, the principal of the school was Latinx, grew up within the same community as the school, and therefore shared the same culture as his students. Thus, we wondered how effective the principal would be in overcoming the cultural, political, and social barriers of students in the predominately Latinx school. We found the school leaders had a heightened awareness of organizational, cultural, and political complexities because of their …

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An Analysis Of The Atmospheric Propagation Of Underground-Explosion-Generated Infrasonic Waves Based On The Equations Of Fluid Dynamics: Ground Recordings, Roberto Sabatini, Jonathan B. Snively, Michael P. Hickey, J. L. Garrison Dec 2019

An Analysis Of The Atmospheric Propagation Of Underground-Explosion-Generated Infrasonic Waves Based On The Equations Of Fluid Dynamics: Ground Recordings, Roberto Sabatini, Jonathan B. Snively, Michael P. Hickey, J. L. Garrison

Publications

An investigation on the propagation of underground-explosion-generated infrasonic waves is carried out via numerical simulations of the equations of fluid dynamics. More specifically, the continuity, momentum, and energy conservation equations are solved along with the Herzfeld-Rice equations in order to take into account the effects of vibrational relaxation phenomena. The radiation of acoustic energy by the ground motion caused by underground explosions is initiated by enforcing the equality, at ground level, between the component of the air velocity normal to the Earth's surface and the normal velocity of the ground layer. The velocity of the ground layer is defined semi-empirically …

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Benner's Model And Duchscher's Theory: Providing The Framework For Understanding New Graduate Nurses' Transition To Practice, Melanie Murray, Deborah Sundin, Vicki Cope Dec 2019

Benner's Model And Duchscher's Theory: Providing The Framework For Understanding New Graduate Nurses' Transition To Practice, Melanie Murray, Deborah Sundin, Vicki Cope

Research outputs 2014 to 2021

The transition to quality and safety in the new graduate registered nurses' practice remains problematic directly impacting patient outcomes. Effective mentoring during transition serves to enhance experiential learning, allowing the development and establishment of safe, quality nursing practice. Comprehensive understanding of the transition process, including the barriers and effective enablers to transition is the key to effective mentoring. A theoretical framework guided by Duchscher's Stages of Transition Theory and Transition Shock Model and Benner's From novice to expert model can facilitate such understanding. Nurse Theorists play an important part in shaping nurse education and practice and have provided nurse educators …

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Application Of Knowledge Management In Academic Libraries: A Swot Analysis, Roseline Bawack Dec 2019

Application Of Knowledge Management In Academic Libraries: A Swot Analysis, Roseline Bawack

Library Philosophy and Practice (e-journal)

Academic libraries do not operate in a vacuum, they coexist with changes, challenges and competition on all levels, therefore, strategies must be developed to ensure that academic libraries can face these challenges, become more efficient in their operations and be responsible to the needs and demands of their users. To do this requires among others an examination of both the internal library environment and the external environment (Broadhead 1991). Academic libraries must know their internal strengths, take advantage of opportunities, avoid all threats and address weaknesses. SWOT stands for Strengths, Weaknesses, Opportunities and Threats. A SWOT analysis of an academic …

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Microscopic Fabric Characteristics Of Typical Red Soft Rock In Badong Formation Under Uniaxial Compression Test, Xiao Zunqun, Wang Xin, Tang Dongsang, Dong Qiongying, Jiang Yinan, Yang Kai, Cao Tongtong, Deng Zhen Dec 2019

Microscopic Fabric Characteristics Of Typical Red Soft Rock In Badong Formation Under Uniaxial Compression Test, Xiao Zunqun, Wang Xin, Tang Dongsang, Dong Qiongying, Jiang Yinan, Yang Kai, Cao Tongtong, Deng Zhen

Coal Geology & Exploration

Red silty mudstone and argillaceous siltstone are the representatives of special rock and soil in Badong Formation, are easy to disintegrate when encountering water. According to the uniaxial compression test of rock samples, a numerical model of medium and soft rock uniaxial compression test was established based on PFC2D program. With the characteristics of stress-strain curve, subsection quantitative parameter calibration method was used to calibrate the microscopic parameters of soft rock samples. The adjustment method and the ratio of tangential bond strength(σc/τc) control specimen under uniaxial compression failure mode. The uniaxial compression test of silty …

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Analysis Of Suitable Development Technology Of Cbm(Gas) In Guizhou, Xu Xiaoqian, Meng Yingfang, Duan Zhengpeng, Li Guohong, Li Qingsong Dec 2019

Analysis Of Suitable Development Technology Of Cbm(Gas) In Guizhou, Xu Xiaoqian, Meng Yingfang, Duan Zhengpeng, Li Guohong, Li Qingsong

Coal Geology & Exploration

In recent years, technical bottlenecks have been encountered in the practice of CBM exploration and development in Guizhou Province, selecting suitable development technology is one of the key issues. Based on the background that CBM exists in thin coal seams and geological structures are complicated in Guizhou, combined with successful development and utilization of CBM, the CBM development and utilization technology suitable for complex geological conditions in Guizhou was put forward. Air drilling is recommended for drilling in Guizhou, according to different distance of thin seams, such as optical casing composite fracturing and salvageable bridge plug fracturing can be used. …

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Key Technology Of Drilling In-Seam Directional Borehole Of 3 000 M In Underground Coal Mine, Shi Zhijun, Dong Shuning, Yang Junzhe, Xu Chao, Hao Shijun, Li Quanxin, Chen Dianfu, Yao Ke, Liu Jianlin, Tian Dongzhuang Dec 2019

Key Technology Of Drilling In-Seam Directional Borehole Of 3 000 M In Underground Coal Mine, Shi Zhijun, Dong Shuning, Yang Junzhe, Xu Chao, Hao Shijun, Li Quanxin, Chen Dianfu, Yao Ke, Liu Jianlin, Tian Dongzhuang

Coal Geology & Exploration

The pre-mining gas governance mode in Baode coal mine requires that long directional borehole of more than 3 000 m can be drilled along coal seam. In view of the existing technology and equipment, there are technical problems in the construction of ultra-long directional borehole, such as the difficulty of sliding drilling, the large hydraulic pressure consumption in inlet waterway, the limited transmission distance of wireline MWD signal, and incapability of flushing liquid recycle. The technology of friction reduction in sliding drilling based on the hydraulic thrust of DHM and the torsion penetration of the ultra-long drilling tool, the technology …

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Extension Model Of Fracturing Cracks Of Translayer Horizontal Well In Roof Of Soft Coal Reservoir, Wang Zhirong, Hu Kai, Yang Jie, Chen Lingxia Dec 2019

Extension Model Of Fracturing Cracks Of Translayer Horizontal Well In Roof Of Soft Coal Reservoir, Wang Zhirong, Hu Kai, Yang Jie, Chen Lingxia

Coal Geology & Exploration

In order to study the propagation rules of hydraulic fracturing crack formed by a horizontal well in roof to coal seam, taking the Permian-Carboniferous coal field in North China as an example, through the classical theory of fracture mechanics, damage mechanics and fluid mechanics, combined with field actual data, the modeling and verification of the space-time evolution law of the crack propagation distance and fracturing time were carried out. Firstly, considering the additional stress of perforation, the characteristics of primary fracture and the permeability characteristics of rock formation, the calculation formula of cracking pressure of vertical hydraulic fracture caused by …

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Technology Feasibility Of Gas Drainage With Comb-Shaped Long Borehole In Floor Instead Of Translayer Borehole, Li Hong, Liu Mingju, Hao Guangsheng, Deng Qigen, Dong Yanjun Dec 2019

Technology Feasibility Of Gas Drainage With Comb-Shaped Long Borehole In Floor Instead Of Translayer Borehole, Li Hong, Liu Mingju, Hao Guangsheng, Deng Qigen, Dong Yanjun

Coal Geology & Exploration

Drainage technology of translayer borehole in floor roadway and directional long hole are the most important gas control measures in high gas and outburst-prone mining face at present. The coal seam in Zhaozhuang mine has the characteristics of being soft and low gas permeability. It is difficult to drill and form holes in a coal seam. For gas control, the major method is to drill a translayer borehole to eliminate gas outburst, supplemented by in-seam gas drainage boreholes. However, there are shortcomings such as large engineering volume, long construction period and high cost of drilling in floor rock roadway. The …

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An Improved Method For Characterizing Coal Metamorphism By Xrd, Wang Chao, Zhao Younan, Wang Zhenwei, Lu Zhaolin Dec 2019

An Improved Method For Characterizing Coal Metamorphism By Xrd, Wang Chao, Zhao Younan, Wang Zhenwei, Lu Zhaolin

Coal Geology & Exploration

At present, the X-ray measurement method of coal metamorphism has the problem that the γ band is not well divided, the δ peak information is not used, and the background of the bottom is unreasonable. The X-ray diffraction pattern of coal with different metamorphosed degrees is compared and studied. It is proposed to correct the metamorphic coefficient formula by using the information of the slope of the 002 peak, the extended half-height width and the δ peak without deducting the so-called background information. The calculation of the XRD patterns of coal samples with different degrees of metamorphism is verified. The …

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Effect Of False Boundary Of Microscopic Image On Automatic Identification Of Maceral Group, Song Xiaozhong Dec 2019

Effect Of False Boundary Of Microscopic Image On Automatic Identification Of Maceral Group, Song Xiaozhong

Coal Geology & Exploration

In automatic detection of coal petrology by image analysis technology, it is found that the boundary of various components in the microscopic image of coal petrology demonstrates a "rim" of gray transition zone, and the pixel of this rim cannot reflect the true gray level of the components on both sides. In order to analyze its influence on the identification and detection of macerals, the characteristics and causes of the false boundary between various adjacent components were studied with analysis of microscopic images collected from a large number of coal samples in China. Generally, the false boundary is ring-shaped or …

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Effects Of Iron-Nickel Ion Combination On Methane Produced By Lignite Fermentation, Xia Daping, Huang Song, Zhang Huaiwen Dec 2019

Effects Of Iron-Nickel Ion Combination On Methane Produced By Lignite Fermentation, Xia Daping, Huang Song, Zhang Huaiwen

Coal Geology & Exploration

In order to study the mechanism of the influence of exogenous optimal iron-nickel ions combination on the gas production process of fermentation, taking Daliuta lignite as an example, experiments were carried out with different contents of iron-nickel ions and the optimal concentration of single ions was elected. The optimal combination concentration of iron-nickel ions were determined by combined design of quadratic regression and common rotation. The fermentation broth of experiment group and blank group(not to added any ions), the coal sample of before and after experiment were analyzed by gas chromatography, X-ray diffraction, Fourier transform infrared spectroscopy, etc. The results …

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Origin And Geochemical Characteristics Of Coalbed Methane In Abandoned Coal Mines, Panzhuang Block, Southern Qinshui Basin, Liu Chao, Feng Guorui, Zeng Fangui Dec 2019

Origin And Geochemical Characteristics Of Coalbed Methane In Abandoned Coal Mines, Panzhuang Block, Southern Qinshui Basin, Liu Chao, Feng Guorui, Zeng Fangui

Coal Geology & Exploration

In order to analyze the carbon and oxygen composition and origin of the coal seam gas(CSG) in abandoned mines, Panzhuang block, south of Qinshui basin, in this paper, the coalbed methane and produced water samples were collected. The results show that the CSG of abandoned mines is dominated by CH4, the average is 91.99%, with minor amounts of N2(6.73%) and CO2(1.26%). The δ13C values of CH4 range from -31.36‰ to -33.53‰, with an average of -32.25‰, the hydrogen isotope(δD) value is between -182.76‰ and -193.20‰, and the average value …

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Mine Water Inrush Rescue Model Based On Optimized Spfa Algorithm, Cai Mingjie, Zhu Xi’An, Liu Demin, Wang Zhangang Dec 2019

Mine Water Inrush Rescue Model Based On Optimized Spfa Algorithm, Cai Mingjie, Zhu Xi’An, Liu Demin, Wang Zhangang

Coal Geology & Exploration

Due to the occurrence of coal mine water inrush accidents, it is easy to cause major personnel and property losses. In order to improve the emergency rescue capability of mine water inrush disasters and reduce the water inrush hazard, a mine water inrush rescue route model was proposed. The undirected map and the adjacency list were used to describe and store the mine roadway network. According to the calculation ratio of the height of the water level and the height of underground personnel in roadway, the safety coefficient of the roadway was calculated, and then the equivalent length of the …

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Optimization Study On Correlation Method Of Multiple Coal Seams, Shu Jiansheng, Ma Liang, Jia Lilong Dec 2019

Optimization Study On Correlation Method Of Multiple Coal Seams, Shu Jiansheng, Ma Liang, Jia Lilong

Coal Geology & Exploration

At present, the development trend of coal mining in China is transferring from the east to the western regions. The Yan'an Formation coal bearing measures middle Jurassic is the most widely distributed in the west, it is of the continental sedimentary environment, which has the characteristics of big change of lithofacies, multiple coal seams, unstable coal seams and less marker, there are difficulties in coal seam correlation, such as lack of basis and multi-solution phenomenon. Based on the wide application of high precision seismic exploration and digital logging technology, the fine correlation of terrestrial multi-coal seams was carried out by …

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Simulation Of Seepage Water Inrush Mechanism And Strength Controlling Factors Of Collapse Column, Huo Bingjie, Xie Zhenhua, Fan Zhanglei, Jing Xuedong Dec 2019

Simulation Of Seepage Water Inrush Mechanism And Strength Controlling Factors Of Collapse Column, Huo Bingjie, Xie Zhenhua, Fan Zhanglei, Jing Xuedong

Coal Geology & Exploration

In order to study the mechanism and main control factors of seepage water inrush in roadway affected by collapse columns, Darcy, Brinkman and N-S equations were used to describe the linkage system of flow field in aquifer, collapse column and water inrush roadway. Variables such as different parameters and different boundaries were selected to analyze the main factors influencing the seepage water inrush intensity of collapse columns. The results show that under the conditions of constant pressure and flow, the increase of aquifer permeability will lead to the increase of flow velocity in an area where the aquifer meets the …

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Particle Swarm Optimization-Based Bionic Principle For Solving Hydrodynamic Dispersion Coefficient In Jiang'an Campus, Mei Jie, Li Guangwei, Xia Chengcheng, Liu Yaping, Liu Wen, He Xinyue Dec 2019

Particle Swarm Optimization-Based Bionic Principle For Solving Hydrodynamic Dispersion Coefficient In Jiang'an Campus, Mei Jie, Li Guangwei, Xia Chengcheng, Liu Yaping, Liu Wen, He Xinyue

Coal Geology & Exploration

Hydrodynamic dispersion coefficient is an important parameter in the study of solute transport in groundwater. In order to understand the transport law of pollutants in groundwater, the particle swarm optimization(PSO) algorithm based on bionic principle is used to solve the hydrodynamic dispersion coefficient of phreatic aquifer under natural flow field in the dispersion test site of Jiang'an Campus of Sichuan University. Compared with the least-square method and the standard curve comparison method, the results show that the results of the standard curve method are subject to subjective influence, and the errors are relatively large. The results of least square method …

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Surface Subsidence Law Caused By Fully Mechanized Caving Mining Under Railway, Deng Niandong, Yao Ting, Shang Hui, Liu Donghai Dec 2019

Surface Subsidence Law Caused By Fully Mechanized Caving Mining Under Railway, Deng Niandong, Yao Ting, Shang Hui, Liu Donghai

Coal Geology & Exploration

In order to ensure the safe running of the special railway for Guozhuang coal mine, the law of surface movement and deformation in goaf of the coal mine was studied on the basis of the analysis of the actual observation data, the monitoring scheme and control measures of railway under dynamic coal mining conditions were put forward in accordance with that. The results show that the surface movement and deformation are intense, the subsidence value is large, but the subsidence velocity is relatively small on account of fully mechanized caving; Surface subsidence coefficient, the main impact tangent tanβ, …

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Nishihara Acceleration Model-Based Experiment Of Creep Characteristics Of Coal, Qu Lina, Li Bo Dec 2019

Nishihara Acceleration Model-Based Experiment Of Creep Characteristics Of Coal, Qu Lina, Li Bo

Coal Geology & Exploration

For conquering limitation that the traditional Nishihara model cannot describe the accelerated creep characteristics of coal body, according to the visco-elastic-plastic flow characteristics of coal in the accelerated creep stage, a nonlinear visco-elastic-plastic model was used to replace the ideal viscoelastic-plastic body in Nishihara model to establish the improved Nishihara acceleration model. And creep equation of the improved model under equal confining pressure triaxial condition was also deduced. Afterwards, the improved accelerated creep model was analyzed by the creep test data of coal specimens in the triaxial creep tests using the method of model identification. The results show that the …

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Shear Strength Characteristics Of Slope Soil In Dumping Site In High-Cold Mining Area, Zhou Linhu, Yang Youqing, Hu Xiasong, Li Xilai, Wang Tao, Liu Changyi Dec 2019

Shear Strength Characteristics Of Slope Soil In Dumping Site In High-Cold Mining Area, Zhou Linhu, Yang Youqing, Hu Xiasong, Li Xilai, Wang Tao, Liu Changyi

Coal Geology & Exploration

The paper aims to study the shear strength characteristics and the influencing factors of the root-soil composite systems of herbs in the dump slope of the high-cold mining area. The dumping site of Jiangcang mining area of Muli Coalfield, located in the northeastern Qinghai-Tibet Plateau, was selected as the study area. For the dump slope which was planted with Elymusnutans Griseb., combined with Poacrymophilakeng, density, moisture content and root content of different depths of root-soil composite systems below the surface of slope were tested; the cohesion and the internal friction angle of soil without roots and root-soil composite systems …

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Optimization Of Surface Contact-Based Thermal Conductivity Model Of Cemented Particles, Chen Yuanjiang, Jiang Zhiqiang, Tan Zhiren Dec 2019

Optimization Of Surface Contact-Based Thermal Conductivity Model Of Cemented Particles, Chen Yuanjiang, Jiang Zhiqiang, Tan Zhiren

Coal Geology & Exploration

In order to explore better the variation law of thermal conductivity of geomaterials, and reduce the thermal damage caused by the problem, according to the structural characteristics of the cemented particles, combined with the effective medium thermal conductivity model and the surface contact thermal conductivity model, the effective thermal conductivity calculation model suitable for the geotechnical cemented particulate material was constructed, and the state of the particulate matter and the cementitious matrix were considered. The transient hot wire method was applied to test the thermal conductivity of the experimental test block, and the predicted values were compared with the measured …

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Numerical Calculation Of Heat Transfer In Single Medium-Deep Geothermal Well, Shang Hongbo, Zhao Chunhu, Jin Dewu, Xu Shuanhai, Wang Xiaodong, Zhang Weidong, Han Yongliang Dec 2019

Numerical Calculation Of Heat Transfer In Single Medium-Deep Geothermal Well, Shang Hongbo, Zhao Chunhu, Jin Dewu, Xu Shuanhai, Wang Xiaodong, Zhang Weidong, Han Yongliang

Coal Geology & Exploration

Medium-deep geothermal single well heat transfer is a technology of developing geothermal energy to "obtain heat without extracting groundwater". This technology has the advantages of not damaging the groundwater environment and taking more heat. However, there are few studies on the numerical calculation of single well heat transfer above 3000m depth. In this paper, based on the geothermal geological conditions in Xi'an, the numerical method was used to calculate the heat transfer of a medium-deep geothermal single well with different well structures (L-shaped directional wells and cluster directional wells) under the scenario of continuous operation of a heating season. The …

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Fluid Factor Of Fracture And Seismic Velocity Response In Anisotropic Coal Beds, Li Qin, Ma Suibo, Zhao Bin Dec 2019

Fluid Factor Of Fracture And Seismic Velocity Response In Anisotropic Coal Beds, Li Qin, Ma Suibo, Zhao Bin

Coal Geology & Exploration

The storage and transport of gas and water in coal seam are related to the density, strike and filler of cracks. Research on the identification and prediction of coal seam cracks will be helpful to prevent and control disastrous accidents in coal mines, such as water inrush and gas outburst. It plays an important role in the safety evaluation of coal mining. Based on the theory of fracture equivalent model, the variation characteristics of fluid factor in coal seam crevices with different fillings and fracture weaknesses parameters(fracture density, aspect ratio, volume modulus, shear modulus, Lamé parameters) are analyzed by combining …

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Influencing Factors Of Azimuth Electromagnetic Wave Roof And Floor Detection While Drilling Along Coal Seam, Chen Gang, Fan Yiren, Li Quanxin Dec 2019

Influencing Factors Of Azimuth Electromagnetic Wave Roof And Floor Detection While Drilling Along Coal Seam, Chen Gang, Fan Yiren, Li Quanxin

Coal Geology & Exploration

Aiming at the problems of poor detection accuracy and low efficiency of roof and floor interface in horizontal well drilling in coal mine, the design idea of explosion-proof azimuth electromagnetic wave logging tool while drilling in coal mine is put forward. In order to suit the working environment of underground coal seam, the influence of instrument parameters such as source distance, transmitting frequency and coil installation angle on signal response was obtained by forward simulation. The results show that the received signal strength of the azimuth electromagnetic wave instrument while drilling increases with the increase of transmitting frequency, coil distance …

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Csamt Phase Correction And Its Application In Detection Of Water-Accumulating Area Of Goaf In Coal Mine, Su Chao, Hou Yanwei, Wang Cheng, Li Dan Dec 2019

Csamt Phase Correction And Its Application In Detection Of Water-Accumulating Area Of Goaf In Coal Mine, Su Chao, Hou Yanwei, Wang Cheng, Li Dan

Coal Geology & Exploration

Magnetic field data of controlled source audio magnetotelluric method(CSAMT) is vulnerable to electromagnetic interference, and will lead to serious degradation of phase data quality. The affected phase data are corrected by referring to the high quality phase data of adjacent measuring points and combining the least squares fitting and interpolation method. Through forward simulation analysis, it is found that cubic polynomial interpolation is effective, not only can restore the variation characteristics of phase curve more accurately, but also involve the corrected phase data in the inversion calculation, so that the inversion results are more accurate and reliable. The method is …

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