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2021

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Full-Text Articles in Engineering

Improvement And Test Of Radar Imaging Logging Tool For Oil And Gas Wells, Zhao Yonggang Oct 2021

Improvement And Test Of Radar Imaging Logging Tool For Oil And Gas Wells, Zhao Yonggang

Coal Geology & Exploration

The detection depth of traditional logging tools is basically less than 3 m, and without azimuth resolution, the formation structure in larger area around wells cannot be imaged. Therefore the problems arising in the detection of subtle structure and oil and gas reservoirs can not be solved. In response to such problems, radar imaging logging tool is developed by applying ground penetrating radar imaging technology to logging. In order to improve the detection depth, azimuth resolution and downhole depth of the tool, a nanosecond pulse source and directional receiving antennae are used to detect and image the formation around the …


Research And Application Of Horizontal Wire-Line Directional Deviation Correction While Drilling, Wu Jinsheng, Huang Xiaolin, Jiang Bing, Zhang Chi, Wu Wanjiong Oct 2021

Research And Application Of Horizontal Wire-Line Directional Deviation Correction While Drilling, Wu Jinsheng, Huang Xiaolin, Jiang Bing, Zhang Chi, Wu Wanjiong

Coal Geology & Exploration

In wire-line core drilling of horizontal holes, the rotation axis of the drilling tool is not in a straight line with its own gravity direction; with the ground hole pressurized, the drilling trajectory will be deviated due to the soft and hard formation or the occurrence of the rock formation. At present, there is no effective way to achieve directional deviation correction while drilling. This paper studies the pushing, fixing and fishing technologies of small-diameter horizontal wire-line directional instruments while drilling. A set of horizontal rope directional drilling tools and directional technology are developed and applied in directional deviation correction …


Design And Application Of Pdc Bit For Large Diameter Directional Drilling Of Coal Seam Roof With Double Stage And Double Speed, Gao Xiaoliang, Ju Pei, Zhao Jianguo Oct 2021

Design And Application Of Pdc Bit For Large Diameter Directional Drilling Of Coal Seam Roof With Double Stage And Double Speed, Gao Xiaoliang, Ju Pei, Zhao Jianguo

Coal Geology & Exploration

The development of large diameter directional drilling technology has provided technical support for the extraction of gas in the upper corner of the goaf by "replacing roadway with borehole". At present, conventional large-diameter drilling mainly adopts the step-by-step hole-forming method, which solves the problem of insufficient power of large-diameter drilling equipment in underground coal mines. However, step-by-step reaming requires multiple times of lifting and lowering, long auxiliary time and intensive labor of the workers. In order to improve the drilling efficiency of large-diameter holes in the coal roof, a double stage drilling process with two speeds was developed. The process …


Application And Development Of Advanced Drilling Technology For Coal Mine Roadway Heading, Zhang Youzhen, Fan Tao, Kan Zhitao, Wei Hongchao, Chen Hongyan Oct 2021

Application And Development Of Advanced Drilling Technology For Coal Mine Roadway Heading, Zhang Youzhen, Fan Tao, Kan Zhitao, Wei Hongchao, Chen Hongyan

Coal Geology & Exploration

With the development of intelligent and fast roadway heading in coal mines, the demand for advanced and fine exploration of heading face is becoming increasingly urgent. Considering the technical characteristics of roadway heading and tunnel drilling, this paper firstly analyzes the technical characteristics and technical requirements of roadway heading advanced drilling under the background of intelligent green mining of coal mines and describes the innovative practice of technology and equipment, such as the integration of excavation and exploration, dual-arm advanced drilling and comprehensive exploration based on directional drilling to effectively solve the contradiction of exploration and excavation and improve the …


Remediation Techniques For Cadmium-Contaminated Dredged River Sediments After Land Disposal, Zhang Changsong Oct 2021

Remediation Techniques For Cadmium-Contaminated Dredged River Sediments After Land Disposal, Zhang Changsong

Coal Geology & Exploration

The remediation of heavy metal Cd contamination in municipal waste is one of the urgent environmental problems in China. To determine the best Cd pollution remediation technology, this paper investigates the applicability of various cadmium(Cd) remediation techniques in river treatment. These remediation methods are compared and analyzed based on the dredged river sediments after land disposal in a city in East China. Three remediation techniques of stabilization, soil leaching, and phytoremediation, are compared by analyzing the performance of the techniques for Cd-contaminated soil remediation. The experimental results show that the stabilization technique reduced the leaching rate of soil Cd from …


Understanding Transantiago Users’ Motivations For Paying Or Evading Payment Of Bus Fares, Carolina Busco, Felipe González, Yamil Jaqueih, Felipe Jiménez, Borja Alonso Oct 2021

Understanding Transantiago Users’ Motivations For Paying Or Evading Payment Of Bus Fares, Carolina Busco, Felipe González, Yamil Jaqueih, Felipe Jiménez, Borja Alonso

Journal of Public Transportation

Transantiago, the public transport system implemented in Santiago, Chile, remains a controversial subject of public debate due to constantly increasing fare evasion rates throughout its decade-long existence. The

Transantiago, the public transport system implemented in Santiago, Chile, remains a controversial subject of public debate due to constantly increasing fare evasion rates throughout its decade-long existence. The research question under consideration in this paper is as follows: What motivates individuals to evade or pay bus fares? To answer this question, we developed a multidisciplinary study that combined relevant engineering expertise with a sociological perspective and combined quantitative analyses with qualitative methodologies …


Development Characteristics And Controlling Factors Of Coal-Measure Source Rocks In The Global Tethys Region, Qu Tong, Huang Zhilong, Wang Rui, Tan Sizhe, Li Zhiyuan, Guo Xiaobo, Zhao Jing, Pan Yongshuai Oct 2021

Development Characteristics And Controlling Factors Of Coal-Measure Source Rocks In The Global Tethys Region, Qu Tong, Huang Zhilong, Wang Rui, Tan Sizhe, Li Zhiyuan, Guo Xiaobo, Zhao Jing, Pan Yongshuai

Coal Geology & Exploration

Under the control of tectonic activity in the Tethys region, a series of basins with coal measure source rocks developed, and the Tertiary coal in the circum Pacific belt is characterized by "hydrogen-rich" and has great hydrocarbon generation potential.This type of coal measure strata is an important source rock in petroliferous basins along the southeast coast of China.Therefore, it is particularly important to systematically analyze the development characteristics and controlling factors of coal measure source rocks under the Tethys background. Based on the systematic analysis of the development age, environments, geochemical characteristics and biomarker characteristics of the coal measure source …


Application Of Surface Nuclear Magnetic Resonance Technology In Detecting Water Abundance In Concealed Burnt Zone, Hou Enke, Fan Jiangwei, Gao Lijun, Wang Jianwen, Chen Dehai, Chi Baosuo, Wang Hongke Oct 2021

Application Of Surface Nuclear Magnetic Resonance Technology In Detecting Water Abundance In Concealed Burnt Zone, Hou Enke, Fan Jiangwei, Gao Lijun, Wang Jianwen, Chen Dehai, Chi Baosuo, Wang Hongke

Coal Geology & Exploration

The overlying bedrock composite aquifer(including weathered bedrock and burnt rock aquifer) in the concealed burnt zone of coal seams is one of the main threats to coal mining. It is of great significance to clarify the water enrichment of the concealed burnt zone for the prevention and control of coal mine water hazards. Ningtiaota Coal Mine, which has experienced a large water inrush accident, was used as the research object, and the Surface Nuclear Magnetic Resonance(SNMR) was used to detect the water enrichment of the aquifer in the concealed burnt area. The results show that there are two aquifers in …


Analyzing The Effect Of Delta Airlines' Fleet Upgrade On Operations At Atlanta-Hartsfield Jackson International Airport, Carlos Alberto Castro, Shlok Misra Oct 2021

Analyzing The Effect Of Delta Airlines' Fleet Upgrade On Operations At Atlanta-Hartsfield Jackson International Airport, Carlos Alberto Castro, Shlok Misra

Publications

Commercial aviation has seen a growth in terms of passengers traveled and flights operated in the past decade (BTS, 2020). To cope up with this growth, airlines adopt various strategies such as network expansion and fleet upgrades. Airlines adopt fleet upgrade strategies to modernize their fleet, reduce costs, expand network coverage, and improve customer loyalty and experience. Research suggests that change in wake turbulence categorization and aircraft performance can directly impact the movements and delays at an airport. For this study, Delta Airline's fleet upgrade program and its effect on operating parameters at Atlanta-Hartsfield Jackson International Airport were analyzed. The …


Student Engagement In Aviation Massive Open Online Courses (Moocs), Jennifer M. Edwards, Haydee M. Cuevas, Felix Brito, Mark Friend, Maryjo O. Smith Oct 2021

Student Engagement In Aviation Massive Open Online Courses (Moocs), Jennifer M. Edwards, Haydee M. Cuevas, Felix Brito, Mark Friend, Maryjo O. Smith

Publications

As online training in the aviation industry continues to expand, understanding how learners engage in open online courses may help inform course design. Currently little is known about student engagement in aviation Massive Open Online Courses (MOOCs) and more information is needed about those who utilize, but do not complete them. Datasets from two aviation MOOCs were cluster-analyzed to determine subpopulations based on activity (discussions, videos, quizzes). Differences were examined for days of activity and completion. Survey data revealed differences in demographics and learning goals. Three significantly different subgroups were found for each MOOC. Engagement patterns were similar between corresponding …


Table Of Contents, The Editors Oct 2021

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.


Coupling Simulation Of Groundwater Dynamics And Solute Transfer In The Process Of Deep Reinjection Of Mine Water, Zhao Chunhu, Yang Jian, Wang Shidong, Zhou Jianjun, Xu Feng, Liu Ji Oct 2021

Coupling Simulation Of Groundwater Dynamics And Solute Transfer In The Process Of Deep Reinjection Of Mine Water, Zhao Chunhu, Yang Jian, Wang Shidong, Zhou Jianjun, Xu Feng, Liu Ji

Coal Geology & Exploration

The deep well reinjection of mine water is a main form of "transfer storage" treatment of mine water. According to the geological and mine water characteristics of the coal mine area in Ordos Basin, the paper puts forward the basis for selecting the target layer of mine water reinjection from the perspective of good matching between groundwater and mine water in the target layer of reinjection, the water isolation of upper and lower strata, permeability and sealing of the reinjection layer. Based on Darcy's law of groundwater and Dupuit's theory, a mathematical model of steady flow of water injection well …


Heavy Metal Pollution Characteristics And Source Analysis Of Water Drainage From A Mine In Inner Mongolia, Wang Tiantian, Jin Dewu, Yang Jian Oct 2021

Heavy Metal Pollution Characteristics And Source Analysis Of Water Drainage From A Mine In Inner Mongolia, Wang Tiantian, Jin Dewu, Yang Jian

Coal Geology & Exploration

Heavy metal pollution evaluation and its source analysis are essential to mine water reuse and protection of ecological environment in mining areas. The objective of this paper is to study heavy metal pollution characteristics and source of heavy metal in mine water. A coal mine from Inner Mongolia Province was chosen as the study area and 49 water samples including surface water, quaternary groundwater, confined groundwater and mine water were collected. Primarily, we detected the concentrations of Zn, Pb, Fe, Mn, As, Cu, Cd, Cr, Hg and Se of water samples to explore heavy metal pollution characteristics and excessive situation. …


Confirmation Of Carbon Emissions In Coal Mining Areas And Research On Low-Carbon Green Development Path, Wang Meng, Ma Ruying, Dai Xuguang, Shan Yadi Oct 2021

Confirmation Of Carbon Emissions In Coal Mining Areas And Research On Low-Carbon Green Development Path, Wang Meng, Ma Ruying, Dai Xuguang, Shan Yadi

Coal Geology & Exploration

Analysis was carried out on the issues such as unclear boundaries of carbon emission sources in coal mining areas, lack of accounting models, and development directions in the context of carbon neutrality. Based on the previous researches and through literature review, data collection and other methods, the boundaries of carbon emission sources in coal mining areas have been clarified and accounting model has been established, clarifying the low-carbon and green development direction of coal mining areas. The sources of carbon emissions(CH4 and CO2) in coal mining areas are divided into two major categories: natural emission and anthropogenic …


Slippage Effect And The Seepage Mechanism Considering The Compaction And Embedding Action Of Proppant, Cheng Qiaoyun, Li Bobo, Li Jianhua, Gao Zheng, Wang Bin Oct 2021

Slippage Effect And The Seepage Mechanism Considering The Compaction And Embedding Action Of Proppant, Cheng Qiaoyun, Li Bobo, Li Jianhua, Gao Zheng, Wang Bin

Coal Geology & Exploration

Hydraulic fracturing technology is an effective method to improve the efficiency of coalbed methane drainage, but the universal embedding of proppant under stress will change the width of the fractures, which will affect the gas slippage effect and the permeability mechanism. In order to explore the gas slippage effect and coal seepage law under the background of hydraulic fracturing, the Hertzian contact theory is used to quantify the embedding depth of proppant, and the gas slippage coefficient calculation equation and permeability model of the combined effect of proppant and effective stress are constructed. The results show that under different gas …


Study On P-Wave Velocity And Mechanical Response Characteristic Of Rock In Coal Seam Roof With Supercritical Co2 Injection, Chen Chen, He Xingyi, Niu Qinghe, Yu Hongxu, Xie Xiangyu Oct 2021

Study On P-Wave Velocity And Mechanical Response Characteristic Of Rock In Coal Seam Roof With Supercritical Co2 Injection, Chen Chen, He Xingyi, Niu Qinghe, Yu Hongxu, Xie Xiangyu

Coal Geology & Exploration

Deep coal seam CO2 geological sequestration and enhanced CH4 recovery(CO2-ECBM) can both increase CBM recovery and achieve carbon emission reduction, possessing dual benefits of energy and environment. The geochemical reactions between supercritical CO2(ScCO2), water and coal seam roof can change its physical-mechanical properties and increase the risk of CO2 leakage. In this paper, taking the roof rock of No.3 coal seam in Hudi Mine from Qinshui Basin as the research area, the ScCO2-water-rock geochemical reaction simulation experiment was carried out to explore the geochemical reaction process of ScCO2 …


Adsorption Phase Density Characteristics Of Supercritical Methane Of Granular Coal, Zhang Mingjie, Liu Hao, Jia Tianrang, Gong Ze, Yang Mingxin Oct 2021

Adsorption Phase Density Characteristics Of Supercritical Methane Of Granular Coal, Zhang Mingjie, Liu Hao, Jia Tianrang, Gong Ze, Yang Mingxin

Coal Geology & Exploration

Finding out the characteristics of supercritical methane adsorption phase density of granular coal is the basis of studying the influence of temperature and pressure on methane adsorption amount of coal sample. Granular coal samples collected from Hebi No.6 Mine and Longshan Mine in Anyang-Hebi Coalfield were used to measure the isothermal adsorption lines at temperatures of 308 K, 313 K and 318 K, and pressures of 1-24 MPa by magnetic suspension balance isotherm adsorption device. The intercept method, Langmuir ternary model fitting method and liquid phase density method were used to calculate the adsorbed phase density at adsorption saturation and …


Mine Water Inflow Modes And Scientific Design Of Drainage Boreholes In Roof Confined Aquifer Of Coal Seam, Hu Weiyue, Ji Yadong, Huang Huan Oct 2021

Mine Water Inflow Modes And Scientific Design Of Drainage Boreholes In Roof Confined Aquifer Of Coal Seam, Hu Weiyue, Ji Yadong, Huang Huan

Coal Geology & Exploration

Aiming at the uncertainty of mine water inflow mode, this paper analyzes the spatiotemporal variation characteristics of mine water inflow at first, and get a conclusion that the mine water is composed of static storage and dynamic recharge. And the static storage is mainly affected by weighting interval, the aquifer thickness of caving and fracture zone height and specific yield; the dynamic recharge is mainly affected by caving and fracture zone height and specific yield, hydraulic gradient in permeable flow field and discharge section area. According to the spatial relationships between water conducted fissure and roof aquifer of coal seam, …


Optimization Of Regional Advanced Coal Floor Water Hazard Prevention And Control Technology And Its Application, Zheng Shitian, Ma Hewen, Ji Yadong Oct 2021

Optimization Of Regional Advanced Coal Floor Water Hazard Prevention And Control Technology And Its Application, Zheng Shitian, Ma Hewen, Ji Yadong

Coal Geology & Exploration

In order to optimize the grouting process, improve the effect of the technology, and promote its application, this paper presents an investigation on the application of the regional advanced coal floor water hazard prevention and control technology in Huaibei mining area. The investigation shows that the pressure control in low pressure diffusion and medium pressure strengthening stages plays a major role in controlling the total grouting volume, which directly affects the limestone aquifer reformation. The prediction formula for grouting volume for strata with different karst fractures can provide guidance to the grouting engineering design. In addition, the horizontal layout method …


Performance Deterioration Law Of Retarded Cement Slurry And Its Mixed Slurry In Freezing Borehole Mud Replacement, Li Qiang, Wang Yansen, Wang Chunlin, Xu Shengji, Fan Zhiqiang Oct 2021

Performance Deterioration Law Of Retarded Cement Slurry And Its Mixed Slurry In Freezing Borehole Mud Replacement, Li Qiang, Wang Yansen, Wang Chunlin, Xu Shengji, Fan Zhiqiang

Coal Geology & Exploration

The mud replacement of freezing hole has become a necessary part of freezing shaft sinking in rock strata, but in the lowering process, the freezing pipe is prone to excessive slurry viscosity resistance, and even be locked, leading to borehole failure. In order to deeply understand the performance deterioration law of cement slurry and its mixture in deep hole environment, the laboratory tests of retarded cement slurry and mixed slurry are carried out respectively, taking the apparent viscosity as the measurement index and considering the factors such as curing time, temperature, water loss state and volume ratio of mixed slurry. …


Friction Law Of Compound Drilling Along The Coal Seam With Super-Long Directional Drilling, Xu Chao, Jiang Lei, Wang Xian, Fang Jun, Chen Pan, Liu Zhi Oct 2021

Friction Law Of Compound Drilling Along The Coal Seam With Super-Long Directional Drilling, Xu Chao, Jiang Lei, Wang Xian, Fang Jun, Chen Pan, Liu Zhi

Coal Geology & Exploration

The internal friction is the main factor affecting the drilling rate and drilling efficiency in super-long directional drilling in coal mines. In order to meet the objective demand of gas drainage mode in big panels, the friction and its influence law in drilling process are studied. To provide a basis for the selection of friction reduction process parameters of compound drilling along coal seam with super-long directional drilling, the drill string motion characteristics and stress state under the condition of near-horizontal compound drilling in the coal mine are analyzed. With certain conditional assumptions, the mechanical models of axial frictional resistance …


Application Of Air Foam Composite Directional Drilling Technology In Broken Soft Coal Seams, Liu Jianlin, Fang Jun, Chu Zhiwei, Yang Weifeng Oct 2021

Application Of Air Foam Composite Directional Drilling Technology In Broken Soft Coal Seams, Liu Jianlin, Fang Jun, Chu Zhiwei, Yang Weifeng

Coal Geology & Exploration

In order to meet the requirements of air screw motor cooling and lubrication, coal dust removal treatment at the orifice and water outlet disposal in the air directional drilling, an air foam composite directional drilling technology for broken soft coal seams has been developed based on the analysis of drilling slag migration characteristics of air directional drilling. The key technologies such as stable and efficient foaming, "mechanical + foam" composite slag discharge and "air + foam" composite drilling were integrated. The technology was also equipped with directional drillrig, foam generation perfusion system, air screw motor, special-shaped drill pipe and measurement …


Prevalence Of Pretransition Disordering In The Rutile-To-Cacl2 Phase Transition Of Geo2, G. Alexander Smith, Daniel Schacher, Jasmine K. Hinton, Daniel Sneed, Changyong Park, Sylvain Petitgirard, Keith V. Lawler, Ashkan Salamat Oct 2021

Prevalence Of Pretransition Disordering In The Rutile-To-Cacl2 Phase Transition Of Geo2, G. Alexander Smith, Daniel Schacher, Jasmine K. Hinton, Daniel Sneed, Changyong Park, Sylvain Petitgirard, Keith V. Lawler, Ashkan Salamat

Physics & Astronomy Faculty Research

The ability to tailor a material's electronic properties using density driven disordering has emerged as a powerful route to materials design. The observation of anomalous structural and electronic behavior in the rutile to CaCl2 phase transition in SnO2 led to the prediction that such behavior is inherent to all oxides experiencing such a phase transition sequence [Smith et al., J. Phys. Chem. Lett. 10, 5351 (2019)1948-718510.1021/acs.jpclett.9b01633]. Here, the ultrawide band gap semiconductor GeO2 is confirmed to exhibit anomalous behavior during the rutile to CaCl2 phase transition. A phase pure rutile GeO2 sample synthesized under high-pressure, high-temperature conditions is probed using …


Computer Simulation For Continuous Centrifugation Of High-Density Cell Cultures, Hironori Tomizawa Oct 2021

Computer Simulation For Continuous Centrifugation Of High-Density Cell Cultures, Hironori Tomizawa

USF Tampa Graduate Theses and Dissertations

Perfusion bioreactors are used for cell production for cell therapies. The system uses cell separation devices such as centrifuge to facilitate cell growth by separating cells and spent media and allows constant media replacement. However, current cell separation technologies can increase shear stress, are generally not continuous processes, and are not as efficient as desired. These limit the amount of media replaced per unit time. Therefore, there is a need for a new system or a method that operates continuously to minimize cell damage, yield high cell concentration, and exchange media effectively. A set of research questions was formulated: (1) …


An Application Of An Unequal-Area Facilities Layout Problem With Fixed-Shape Facilities, Alan Mckendall, Artak Hakobyan Oct 2021

An Application Of An Unequal-Area Facilities Layout Problem With Fixed-Shape Facilities, Alan Mckendall, Artak Hakobyan

Faculty & Staff Scholarship

The unequal-area facility layout problem (UA-FLP) is the problem of locating rectangular facilities on a rectangular floor space such that facilities do not overlap while optimizing some objective. The objective considered in this paper is minimizing the total distance materials travel between facilities. The UA-FLP considered in this paper considers facilities with fixed dimension and was motivated by the investigation of layout options for a production area at the Toyota Motor Manufacturing West Virginia (TMMWV) plant in Buffalo, WV, USA. This paper presents a mathematical model and a genetic algorithm for locating facilities on a continuous plant floor. More specifically, …


The Secret Life Of Stalls, Nihad E. Daidzic Oct 2021

The Secret Life Of Stalls, Nihad E. Daidzic

Aviation Department Publications

FAA Safety Webinar (GL15107982) held online at 9:00 CST on Saturday, October 23, 2021.


Soft Elastomeric Capacitor For Angular Rotation Sensing In Steel Components, Han Liu, Simon Laflamme, Jian Li, Caroline Bennett, William N. Collins, Austin Downey, Paul Ziehl, Hongki Jo Oct 2021

Soft Elastomeric Capacitor For Angular Rotation Sensing In Steel Components, Han Liu, Simon Laflamme, Jian Li, Caroline Bennett, William N. Collins, Austin Downey, Paul Ziehl, Hongki Jo

Faculty Publications

The authors have previously proposed corrugated soft elastomeric capacitors (cSEC) to create ultra compliant scalable strain gauges. The cSEC technology has been successfully demonstrated in engineering and biomechanical applications for in-plane strain measurements. This study extends work on the cSEC to evaluate its performance at measuring angular rotation when installed folded at the junction of two plates. The objective is to characterize the sensor’s electromechanical behavior anticipating applications to the monitoring of welded connections in steel components. To do so, an electromechanical model that maps the cSEC signal to bending strain induced by angular rotation is derived and adjusted using …


Profile Of Zhang Yan, Mary Frost Oct 2021

Profile Of Zhang Yan, Mary Frost

Online Journal of Space Communication

Profile of and interview with Zhang Yan, Gen. Manager, CITICSat and Chief Rep., Asiasat


Profile Of Dianne J. Vanbeber, Mary Frost Oct 2021

Profile Of Dianne J. Vanbeber, Mary Frost

Online Journal of Space Communication

Profile of and interview with Dianne J. VanBeber, V.P., Investor Relations, Corporate & Marketing Communications, Intelsat


Profile Of Barbara Warren, Mary Frost Oct 2021

Profile Of Barbara Warren, Mary Frost

Online Journal of Space Communication

Profile of and interview with Barbara Warren, Systems Analyst, International Telecommunication Union