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Full-Text Articles in Engineering

The Qualification Of Sealability And Creep Relaxation Of Additively Manufactured Zytel Gaskets For Pem Fuel Cells, Robert Lazarin Dec 2022

The Qualification Of Sealability And Creep Relaxation Of Additively Manufactured Zytel Gaskets For Pem Fuel Cells, Robert Lazarin

Open Access Theses & Dissertations

The purpose of this thesis is to study the feasibility of low-cost additive manufacturing of gaskets for proton exchange membrane fuel cells exposed to extreme temperature conditions ranging from -55°C to 100°C. With the growing popularity and decreasing costs of additive manufacturing technologies, specifically Material Extrusion (ME), research is being conducted to determine the feasibility of ME components. Thermally cycled PEMFCs may exhibit accelerated gasket deterioration, therefore, the mechanical stability of material extruded gaskets following a harsh thermal cycle must be assessed. The feasibility of the material extruded gaskets will be proven by manufacturing optimization and mechanical testing. The target …


A Case Study In Design, Construction, And Operation Of A Meromictic Solar Pond In Texas, Usa, Bianca Paola Meneses Brassea Dec 2022

A Case Study In Design, Construction, And Operation Of A Meromictic Solar Pond In Texas, Usa, Bianca Paola Meneses Brassea

Open Access Theses & Dissertations

Over the last four decades, meromictic solar ponds have been the subject of limnological studies and engineering research. A case of practical interest is the salinity gradient solar pond (SGSP). SGSP science and technologies have been systemically advanced in El Paso, Texas. This dissertation aims to share lessons learned in designing, constructing, and operating the El Paso Solar Pond, a NaCl-based solar pond that achieved high-temperature performance over two decades, commencing in 1984. Many of the practical lessons learned have not been published and are thus not readily available in archival journals, and this contribution provides a remedy. The value …


Fabrication And Characterization Of Iron-Based Catalysts For The Dehydrogenation Of Fossil Fuels, Victoria Isabel Reyes Dec 2022

Fabrication And Characterization Of Iron-Based Catalysts For The Dehydrogenation Of Fossil Fuels, Victoria Isabel Reyes

Open Access Theses & Dissertations

For a prosperous and sustainable future, hydrogen is an encouraging solution due to its simple transition for industrial decarbonization and synergy for economic development. Paradoxically, current hydrogen production pathways release substantial amount of greenhouse gases into the atmosphere contributing to climate change. To keep up with increasing demand, hydrogen could be produced through microwave-assisted thermocatalytic dehydrogenation of fossil fuels without emitting carbon dioxide. This requires specified catalysts to meet the requirements of hydrogen yield and selectivity. The objective of the present research is to fabricate, characterize, and compare iron-based alumina (FeAl_x O_y) catalysts produced via solution combustion synthesis and iron-based …


Identifying Particulate Matter Spatial Variation In The El Paso Del Norte Region Using Land-Use Regression Modeling And Data Obtained From A Network Of Low-Cost Sensors, Leonardo Demetrio Vazquez-Raygoza Dec 2022

Identifying Particulate Matter Spatial Variation In The El Paso Del Norte Region Using Land-Use Regression Modeling And Data Obtained From A Network Of Low-Cost Sensors, Leonardo Demetrio Vazquez-Raygoza

Open Access Theses & Dissertations

The emergence and rise in popularity of low-cost sensors for atmospheric observation aresetting a new precedent in identifying emission hotspots and providing high-resolution spatial and temporal data. Furthermore, low-cost sensors are becoming popular among institutions and the public, allowing community scientists to become more involved in air quality monitoring. However, concerns about the accuracy and precision of low-cost sensors have been questioned. Most recent research has focused on the utility of real-time monitoring and calibration requirements for these sensors. A low-cost monitoring project has deployed sensors in the El Paso del Norte region in low and high annual average daily …


Rainwater Catchment System Designed For California Polytechnic State University Building 34, Jonah S. Aere Dec 2022

Rainwater Catchment System Designed For California Polytechnic State University Building 34, Jonah S. Aere

Construction Management

California Polytechnic State University currently receives its water supply from either Whale Rock Reservoir, for distilled water, or pumped from six ground wells, for agricultural use. Although the university’s Agricultural College requires a certain amount of water to grow crops, these demands are often not met due to the lack of water within these underground wells. A rainwater capture system could be constructed to ease the water supply burden which is already depleting, reduce wasted drainage, and maintain a sustainable agricultural water source without being dependent on other locations. This would benefit the institution by reducing imported water thereby saving …


Life Cycle Assessment Of Novel Electrochemical Struvite Recovery In Municipal Wastewater Treatment At The Plant And U.S. Watershed Scales, Karla Morrissey Dec 2022

Life Cycle Assessment Of Novel Electrochemical Struvite Recovery In Municipal Wastewater Treatment At The Plant And U.S. Watershed Scales, Karla Morrissey

Graduate Theses and Dissertations

As the supply of phosphorus decreases, nutrient recovery in municipal wastewater treatment has become an important area of research. Recovery methods for phosphorus-containing fertilizers, such as struvite, and other products are currently being developed and assessed for their efficiency and economic feasibility. Potential environmental impacts from nutrient recovery are also being assessed as design for the environment is important, especially with regards to the eutrophying potential of phosphorus in phosphorus-limited freshwater aquatic systems. Life cycle assessment (LCA) is a tool that can be used to estimate potential environmental impacts of a product or service focusing on its entire life cycle. …


The Living Breakwaters Pdr Efforts Econcrete Resource Analysis, Guianina Ferrari, Shervon Stephens, Calvin O. Walters Jr. Dec 2022

The Living Breakwaters Pdr Efforts Econcrete Resource Analysis, Guianina Ferrari, Shervon Stephens, Calvin O. Walters Jr.

Publications and Research

On October 29, 2012, Superstorm Sandy impacted 443,000 people and caused nearly $19 billion (about $58 per person in the US) worth of damage within New York City. As part of the New York City infrastructure reparation plan, the Living Breakwaters project in Tottenville addressed coastal resilience, allocating $100M of public funds to a series of artificial breakwaters by the southwest coast of Staten Island. Each breakwater is constructed and designed to mitigate water flow in storm events. ECOncrete, a primary element of the breakwater, is a specialty cast cementitious product that is marine organism-friendly that encourages biocalcification and photosynthesis. …


2022 Fall Engr333 Seminar Presentation, Jordan Tuter, Aidan Bakker, Samuel Hoover, Jessica Camp Nov 2022

2022 Fall Engr333 Seminar Presentation, Jordan Tuter, Aidan Bakker, Samuel Hoover, Jessica Camp

ENGR 333

File for student presentation on Carbon Neutrality for Calvin University, given by students in the Fall 2022 class of ENGR333.


Theory And Experiment Of The Dual-Bit Torque Self-Balancing Drilling System For Rescue Drilling, Gao Ke, Zhang Cong, Zhao Yan, Li Xu, Wen Yumin, Lyu Xiaoshu, Xie Xiaobo Nov 2022

Theory And Experiment Of The Dual-Bit Torque Self-Balancing Drilling System For Rescue Drilling, Gao Ke, Zhang Cong, Zhao Yan, Li Xu, Wen Yumin, Lyu Xiaoshu, Xie Xiaobo

Coal Geology & Exploration

The rapid and safe construction of rescue channel is an effective method to save the trapped person underground after mine accidents. The conventional rescue hole drilling technologies mainly include the downhole hammer percussion drilling technology and the composite drilling technology, which have the disadvantages of large rig structure, complex drilling process, great disturbance to the formation and low target hit rate. In particular, it is easy to have secondary accidents in the fractured strata, and the rescue requirements could not be effectively met. In order to ensure the formation adaptability and wall stability of rescue boreholes, the dual-bit torque self-balancing …


Occurrence Characteristics And Ecological Risk Assessment Of Heavy Metals In Fly Ash Of Ningdong Energy Chemical Industry Base, Zhang Zhiguo, Tan Yuning, Hu Youbiao, Zheng Yonghong, Chen Denghong, Cai Weiqing, Li Yating, Lu Jiangwei Nov 2022

Occurrence Characteristics And Ecological Risk Assessment Of Heavy Metals In Fly Ash Of Ningdong Energy Chemical Industry Base, Zhang Zhiguo, Tan Yuning, Hu Youbiao, Zheng Yonghong, Chen Denghong, Cai Weiqing, Li Yating, Lu Jiangwei

Coal Geology & Exploration

In order to expand the resource utilization of fly ash, research was conducted based on the fly ash of Yuanyang Lake Power Plant in the Ningdong Energy Chemical Industry Base. Specifically, the physical and chemical properties of fly ash were characterized and analyzed by means of scanning electron microscope, energy spectrum analysis and X-ray diffraction. Besides, the total amount, effective state and content in different forms of Pb, Cr, Ni, Cu, Cd and As in fly ash were determined through acid digestion, DTPA extraction and 5-step Tessier sequential extraction. In addition, the ecological risk of heavy metals in fly ash …


Quantitative Experimental Study On Time-Varying Characteristics Of Bleeding Of Cement-Based Grouting Materials, Zhang Runqi, Xu Bin, Yin Shangxian, Li Shuxia, Chang Yongwang, Lian Huiqing, Cao Min Nov 2022

Quantitative Experimental Study On Time-Varying Characteristics Of Bleeding Of Cement-Based Grouting Materials, Zhang Runqi, Xu Bin, Yin Shangxian, Li Shuxia, Chang Yongwang, Lian Huiqing, Cao Min

Coal Geology & Exploration

Cement-based cementitious materials are the most common grouting materials for grouting engineering. This type of material has obvious water separation effect, and obtaining the quantitative formula of water separation thickness will be helpful to improve the calculation accuracy of slurry diffusion radius. By observing the water separation process of three admixtures, namely pyrophyllite powder (0%-35%), polyvinyl alcohol (0%-8%) and fly ash (0%-90%) in cement-based slurry, the water separating rate, stone formation rate, final water separation time and water separation thickness of the three admixtures were obtained. It is found that the water separation thickness of the slurry varies regularly with …


Heat Conduction Performance And Transfer Mechanism Of Sand-Barite Powder Backfill Materials, Jia Hailiang, Zhu Zixian, Zhou Yang, Sun Qiang Nov 2022

Heat Conduction Performance And Transfer Mechanism Of Sand-Barite Powder Backfill Materials, Jia Hailiang, Zhu Zixian, Zhou Yang, Sun Qiang

Coal Geology & Exploration

The ground source heat pump of buried pipeline is a major form of shallow thermal energy utilization, and the thermophysical properties of backfill materials, especially the thermal conductivity, are the key factors affecting the heat transfer efficiency of the heat pump system. In this paper, the variation law of thermal conductivity of the sand-barite powder samples at different barite powder mixing ratio (volume fraction) and saturation was studied. The mechanism of improving the thermal conductivity of backfill materials with barite powder was revealed based on the macroscopic and microscopic experiments such as stereoscope and nuclear magnetic resonance analysis. In addition, …


Tomography Method For Adjacent Channel Frequency Shift Of Transmitted In-Seam Waves, Tian Han, Wu Rongxin, Hu Ze’An, Yang Qiaonan Nov 2022

Tomography Method For Adjacent Channel Frequency Shift Of Transmitted In-Seam Waves, Tian Han, Wu Rongxin, Hu Ze’An, Yang Qiaonan

Coal Geology & Exploration

In-Seam Seismic is one of the main detection methods for small geological structures in the coal mining working face. In this method, the energy attenuation feature of in-seam waves is mainly utilized. In case of any significant geological anomaly or receivers coupling difference in coal working face, the energy distribution of the in-seam wave at different frequency bands will be significantly affected, and the stability and accuracy of in-seam wave detection results will be decreased. Using the centroid frequency change features of the in-seam wave signals for inversion imaging is an innovative, effective method. However, for this method, there are …


Development Of Rescue Truck-Mounted Drilling Rig In Ground Emergency, Fan Dong, Zou Zujie, Wang Ruize, Lu Feifei, Liu Qi, Wang Hejian Nov 2022

Development Of Rescue Truck-Mounted Drilling Rig In Ground Emergency, Fan Dong, Zou Zujie, Wang Ruize, Lu Feifei, Liu Qi, Wang Hejian

Coal Geology & Exploration

Ground drilling is an effective means to rescue the person trapped underground in case of accident in a mine. The rescue truck-mounted drilling rig is an ideal model for mine accident rescue due to its adaptability to a variety of drilling technologies and the advantages of wide formation adaptability, high mobility and strong accident handling capacity. In view of the shortcomings of domestic truck-mounted drilling rig in the construction of life support hole and large-diameter relief well, ZMK5550TZJF50/120 truck-mounted drilling rig was developed. Specifically, the large capacity power head adaptable to various technologies was developed, adopting the design of installation …


Adaptive Electro-Hydraulic System Of Zmk5550tzjf50/120 Truck-Mounted Drilling Rig With Wob Adaptive Control Function, Chang Jianghua, Zhao Liang, Lu Feifei, Wang Longpeng, Yang Jiangbo Nov 2022

Adaptive Electro-Hydraulic System Of Zmk5550tzjf50/120 Truck-Mounted Drilling Rig With Wob Adaptive Control Function, Chang Jianghua, Zhao Liang, Lu Feifei, Wang Longpeng, Yang Jiangbo

Coal Geology & Exploration

The truck-mounted drilling rig is an ideal model for rescue drilling construction due to its strong mobility and wide process adaptability. The traditional truck-mounted drilling rig adopting the mode of hydraulic control and hydraulic drive has the problems of non-intuitive displaying of control parameters and many pipelines, which is hard to achieve the closed-loop control. In case of drilling into the complex formations, the response speed of the driller is often difficult to adapt to changes in working conditions, which is not conducive to the drilling safety. In order to meet the requirements of safety and high automation of rescue …


Table Of Contents, The Editors Nov 2022

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.


Application Of Pneumatic Dth Hammer In Drilling Rescue Of Mine Accidents, Zhao Jiangpeng, Hao Shijun Nov 2022

Application Of Pneumatic Dth Hammer In Drilling Rescue Of Mine Accidents, Zhao Jiangpeng, Hao Shijun

Coal Geology & Exploration

As an efficient percussive rock breaking tool, pneumatic down-the-hole (DTH) hammer has played an important role in drilling rescue of mine accidents at home and abroad. Herein, the technical characteristics of pneumatic DTH hammer were described from the points of rock breaking mechanism, structure type, drilling method and specification, and the reverse circulation type and its characteristics of pneumatic DTH hammer were emphatically analyzed. Besides, the application of forward circulation drilling of pneumatic DTH hammer and the combined deviation correction drilling of pneumatic DTH hammer and mud screw in small diameter drilling, as well as the research progress of pneumatic …


Formation Mechanism Of Coalbed Methane In Dafosi Mine Field, Huanglong Coalfield, Liu Kaide, Yao Kaiwen, Chen Nengyuan, Fan Zhangqun, Li Shujia, Zheng Han, Yue Wenping, Li Xiaolong Nov 2022

Formation Mechanism Of Coalbed Methane In Dafosi Mine Field, Huanglong Coalfield, Liu Kaide, Yao Kaiwen, Chen Nengyuan, Fan Zhangqun, Li Shujia, Zheng Han, Yue Wenping, Li Xiaolong

Coal Geology & Exploration

Dafosi mine field is a typical low-rank coalbed methane (CBM) field in Binchang mining area of Huanglong Jurassic. There are many coalbed methane wells in the field, but few researches are performed on the formation mechanism of coalbed methane. Thus, it is of great guiding significance to clarify the geochemical characteristics and formation mechanism of coalbed methane (CBM) in the mine field, which could provide important basis for the analysis on productivity difference of high- and low-yield CBM Wells. For this reason, the samples of drained gas at the wellhead of six CBM wells, 22 coal samples of No.4 coal …


Digital Twin Technology Of Geological Information In Mining And Excavation Working Face, Li Peng, Cheng Jianyuan Nov 2022

Digital Twin Technology Of Geological Information In Mining And Excavation Working Face, Li Peng, Cheng Jianyuan

Coal Geology & Exploration

The mine geology transparency is the basis for the intelligent coal mine construction. 3D geological modeling is an important measure for realizing the mine geology transparency. In the geological modeling of the previous working face, there are problems including the discrepancy between the interpolation algorithm and the geological law, the low fusion level of the multi-source heterogeneous geological data, and the seldom coupling between the coal mine production equipment and the geological information. The concept of the digital twin of the geological information about coal mine working face was proposed, the discrete smooth interpolation (DSI) algorithm was adopted, and the …


Key Technologies And Equipment Of Quickly And Safely Building Life Support And Rescue Channel In Mine Disaster, Tian Hongliang, Zou Zujie, Hao Shijun, Cao Ming, Zhou Guanghua, Huang Yong, Gu Hairong, Wang Lei Nov 2022

Key Technologies And Equipment Of Quickly And Safely Building Life Support And Rescue Channel In Mine Disaster, Tian Hongliang, Zou Zujie, Hao Shijun, Cao Ming, Zhou Guanghua, Huang Yong, Gu Hairong, Wang Lei

Coal Geology & Exploration

In case that persons are trapped underground as a result of shaft and roadway damage due to a major disaster accident in a mine, the most effective way of rescue is to construct the rescue channel in a safely and efficient manner. The rescue channel is divided into the underground and ground types. Building a large diameter rescue channel through the collapsed section is the most direct way if underground construction conditions are available. However, if no underground construction conditions are available or it is prone to secondary disasters, it is necessary to drill small diameter rescue holes on the …


Key Technologies Of Surface Efficient Life Support Hole Forming For Mine Rescue, Zhang Biao, Kang Yuguo, Huang Yong, Zhang Ming, Zhou Guang, Ren Yingju, Liu Jianlin, Gao Ke, Zhao Yan Nov 2022

Key Technologies Of Surface Efficient Life Support Hole Forming For Mine Rescue, Zhang Biao, Kang Yuguo, Huang Yong, Zhang Ming, Zhou Guang, Ren Yingju, Liu Jianlin, Gao Ke, Zhao Yan

Coal Geology & Exploration

The surface life support hole, as the support channel for the trapped people underground, is one of the important ground emergency rescue schemes for the situation with some people trapped underground due to mine accidents. Under the complex conditions of the rescue area, including easy collapse, easy leakage, large water inflow and inclined formation, the single hole forming process has the problems such as poor ground adaptability matching, low comprehensive drilling efficiency and difficult roadway penetration, which cannot meet the requirements of rescue. In order to form an efficient drilling technology system for life support holes and improve the response …


Research Progress Of Lifting Equipment For Large-Diameter Borehole Rescue, Gu Hairong, Shan Zenghai, Wang Longpeng, Shao Tao, Zou Zujie, Gao Ziyu Nov 2022

Research Progress Of Lifting Equipment For Large-Diameter Borehole Rescue, Gu Hairong, Shan Zenghai, Wang Longpeng, Shao Tao, Zou Zujie, Gao Ziyu

Coal Geology & Exploration

Rescue through large-diameter relief well is an efficient method of mine emergency rescue. The lifting equipment of large-diameter relief well is used to lift the trapped personnel safely and reliably to the surface through the large-diameter relief well. It is the key equipment in the rescue system of large-diameter relief well. With the rescue technology of large-diameter relief well gradually recognized in the industry, the lifting equipment of large-diameter relief well has developed considerably, forming the fixed and mobile types of lifting equipment and multiple technical routes. Besides, important progress has been made in the research on the lifting equipment …


Research On Key Technology Of Pipe Jacking Drilling Equipment For Large-Diameter Rescue Borehole Of Coal Mine, Wang Lei, Zhu Yuqin, Zhang Weina, Liu Hao, Zhao Wenbo, Yang Chuang, Wang Guanxiong Nov 2022

Research On Key Technology Of Pipe Jacking Drilling Equipment For Large-Diameter Rescue Borehole Of Coal Mine, Wang Lei, Zhu Yuqin, Zhang Weina, Liu Hao, Zhao Wenbo, Yang Chuang, Wang Guanxiong

Coal Geology & Exploration

In order to solve the rescue problem of collapsed roadways in coal mines and improve the drilling speed of large-diameter rescue boreholes, the construction method of large-diameter borehole with pipe jacking technology was proposed. Specifically, the collapsed rock mass was crushed and the slag was removed by pushing the connectable pipe joints and cutter heads with the main jacking equipment arranged in the chamber, so as to form a rescue channel composed of jacked pipes at last. A composite cutter head with large opening under the condition of collapsed rock mass was developed, which is composed of 10 cutters, 10 …


Research And Application Of Synchronous Self-Balancing Feed System For Rescue Truck-Mounted Drilling Rig, Zou Zujie, Tian Hongliang, Liu Qingxiu, Chang Jianghua, Liu Qi, Zhu Guodong Nov 2022

Research And Application Of Synchronous Self-Balancing Feed System For Rescue Truck-Mounted Drilling Rig, Zou Zujie, Tian Hongliang, Liu Qingxiu, Chang Jianghua, Liu Qi, Zhu Guodong

Coal Geology & Exploration

Truck-mounted drilling rig is the core equipment of ground drilling rescue in mine accidents, and it has played an important role in all the successful rescues at home and abroad. However, the feed system, as the main actuator of the truck-mounted drilling rig, exposes the problems of restricted passability of the whole machine due to the long working stroke, difficult maintenance of the positioning wheel train, poor movement synchronization of the double cylinder, guide rail wearing caused by the partial load of power head, and the delay of pulling force displayed by the hydraulic gauge during its service. ZMK5550TZJF50/120 rescue …


Research And Application Of Multi-Source Information Detection Technology For Drilling Rescue Of Mine, Zheng Xuezhao, Sun Ziyu, Guo Jun, Zhang Duo, Chen Gang, He Qinjian Nov 2022

Research And Application Of Multi-Source Information Detection Technology For Drilling Rescue Of Mine, Zheng Xuezhao, Sun Ziyu, Guo Jun, Zhang Duo, Chen Gang, He Qinjian

Coal Geology & Exploration

Drilling rescue of mine is a new type of rescue technology. In order to quickly and accurately obtain the information on drilling channel, the location distance of the trapped person and the characteristics of the gas environment in the disaster area during rescue, as well as to realize the two-way video and audio communication between the trapped person underground and the rescue commander on the ground, theoretical research and technical development were conducted with the technical methods such as multi-source information fusion, dual-stream network video service, edge computing, intrinsically-safe circuit control, and ultra-wideband radar. Meanwhile, two key technologies were proposed: …


Distribution Characteristics Of Trace Elements In Different Density Fractions Of High-Germanium Coal From Wulantuga, Inner Mongolia, China, Duan Piaopiao, Wang Wenfeng, Ma Mengya Nov 2022

Distribution Characteristics Of Trace Elements In Different Density Fractions Of High-Germanium Coal From Wulantuga, Inner Mongolia, China, Duan Piaopiao, Wang Wenfeng, Ma Mengya

Coal Geology & Exploration

The exploitation and utilization of critical metals in coal measures is of great significance to alleviate the shortage of strategic mineral resources in China. In addition to the critical metal germanium (Ge), the low-rank coal from Wulantuga Coal Mine of Shengli Coalfield in Inner Mongolia, China is enriched with the toxic elements Be, F, As, Hg, Sb and W. Considering the extraction and utilization of key metals and environmental protection, the coal in the study area must be washed. As shown in the previous study, flotation is relatively good for the removal of As, Sb and W inWulantuga coal, but …


Main Influencing Factors For Regional Pre-Grouting Technology Of Water Hazard Treatment In Coal Seam Floor And Efficient Hole Arrangement, Hu Weiyue, Zhao Chunhu, Lyu Hanjiang Nov 2022

Main Influencing Factors For Regional Pre-Grouting Technology Of Water Hazard Treatment In Coal Seam Floor And Efficient Hole Arrangement, Hu Weiyue, Zhao Chunhu, Lyu Hanjiang

Coal Geology & Exploration

Regional advance grouting transformation and reinforcement of water conducting formation and aquifer is the main technical means to prevent and control the karst water hazards in the coal seam floor of North China type coalfields. Herein, analysis was conducted for the general application mode of the regional advance grouting transformation and reinforcement for water hazard treatment in the thin and thick limestone layers in the coal seam floor based on the basic mine hydrogeological principle of the application of regional advance grouting transformation technology. In the analysis, consideration was given to the hydrogeological structure of the coal seam floor, the …


Key Pretreatment Technologies For Coalbed Gas Bioengineering And Review On Their Mechanism Of Action, Bao Yuan, Chang Jianing, Liu Xiangrong, Xia Daping, Wang Yaya Nov 2022

Key Pretreatment Technologies For Coalbed Gas Bioengineering And Review On Their Mechanism Of Action, Bao Yuan, Chang Jianing, Liu Xiangrong, Xia Daping, Wang Yaya

Coal Geology & Exploration

Coalbed gas bioengineering (CGB) is a new technology for the purpose of realizing the clean utilization of coal resources and the enhanced recovery of coalbed gas. To explore the key characteristics of the pretreatment technologies of CGB, hydrocarbon generation potential and its mechanism of action, conclusion and summary was made for various pretreatment technologies herein. Meanwhile, the pretreatment technologies were divided into three types according to the action mode of coal (organic matter) and bacteria (microorganism): microflora optimization and improvement, coal dissolution and oxidation, and biological stimulation and synergy. By comparing the capability of coal to generate methane through microbial …


Subgrade Subsurface Anomalous Body Full-Waveform Inversion Based On Ground-Penetrating Radar, Hu Leilei, Chen Kang, Huang Dejun, Yang Rong Nov 2022

Subgrade Subsurface Anomalous Body Full-Waveform Inversion Based On Ground-Penetrating Radar, Hu Leilei, Chen Kang, Huang Dejun, Yang Rong

Coal Geology & Exploration

The hidden dangers of road collapse and underground voids are usually difficult to notice and easy to occur in sudden. They have caused huge losses in people's lives and properties. Therefore, the detection and analysis of road collapse and underground voids are crucial. The ground-penetrating radar (GPR) is the main method for detecting the hidden dangers of urban road collapse currently by virtue of its high accuracy, high efficiency, continuous non-destructiveness and real-time imaging. A convolution type objective function FWI algorithm was proposed to solve the problem of the lower inversion accuracy and practicability caused by the inaccurate estimation of …


Data-Driven State Estimation For Improved Wide Area Situational Awareness In Smart Grids, Md Jakir Hossain Nov 2022

Data-Driven State Estimation For Improved Wide Area Situational Awareness In Smart Grids, Md Jakir Hossain

USF Tampa Graduate Theses and Dissertations

Wide area situational awareness (WASA) in smart grids includes automatic monitoring, perception and detection of anomalies in these systems. The goal of WASA is to make smart grids aware of their physical and operational state for more effective operational decisions and control. As such, tracking the system's state or state estimation is one of the key objectives of WASA. The extensive integration of cyber elements into smart grids, such as large deployment of various monitoring and measurement devices, provides new opportunities to improve WASA. However, the tight coupling of power grids with cyber components introduces vulnerabilities to cyber and physical …