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Transport Of Multi-Phase Multi-Component Fluids In The Shallow Subsurface Influenced By Soil And Surface Boundary Conditions: Experimental And Numerical Study With Application To Natural Gas Leakage, Navodi Jayarathne

Civil and Environmental Engineering Theses and Dissertations

With the increased use of Natural Gas (NG) as a source of fuel, underground leak-related events are increasingly reported, and some are fatal. Subsurface migration and development up to flammable limits are highly dependent on leak characteristics, soil, atmospheric variables, and other surface and subsurface structural complexities. Although few studies have characterized the transient behavior of leaked NG in the shallow subsurface, the underlying mechanisms and their interactions are not well understood, which prevents prediction of the impact of environmental and operating conditions on gas migration. The study conducted a series of field scale-controlled release experiments and numerical simulations to …

Adhesive Force Of Minerals And Substrates, Cynthia Domergue

Posters - 2024

Traditional processing for the separation and concentration of minerals requires a large volume of water to process ores to produce metals and other mineral resources. Furthermore, most copper mines in the US are in the southwest, particularly Arizona and New Mexico, which both have arid climates (Fig. 1). Therefore, sustainable practices need to be developed to maintain the production of metals. Objectives:

• Examine the contact angle of mica and silica at varying surface treatment • Determine the average adhesive forces for each sample

• Compare the average adhesive forces for each sample based on the surface treatment and mineral …

Beavers, Hydrology, And Wapato: A Baseline For Monitoring Franz Lake National Wildlife Refuge, Justine Casebolt

Environmental Science and Management Professional Master's Project Reports

Located in the lower Columbia River floodplain, Franz Lake National Wildlife Refuge is a unique landscape with a complex land use history. For thousands of years, Indigenous tribes lived on this land. In the early 1990s, U.S. Fish and Wildlife Service acquired the land, after it was identified as a mitigation site following the construction of the Bonneville Lock and Dam. Franz Lake Refuge was once known for its prevalent Wapato (Sagittaria latifolia) population, an emergent plant with edible tubers and an important food source for Indigenous people. With specific growth requirements and hydrologic conditions for germination and …

Impacts Of Gas Flaring On Soil Quality In The Ecuadorian Amazon: Measuring Gas Flare Effects On Soils At Comparative Distances In Loma Del Tigre, Orellana, Francesca Lopresti

Independent Study Project (ISP) Collection

Gas flaring, the process of burning off the natural gas excreted during petroleum extraction, has recently been the source of public outcry, citing degraded public and environmental health caused by constant flaring near populated centers. While extensive research has been done on the environmental and health impacts of gas flaring, regionally specific research to the Ecuadorian Amazon is lacking. It is crucial that updated research in this region is produced to inform regulations that have the potential to minimize the physical, environmental, and economic impact of the petroleum industry on nearby, under-resourced, and marginalized communities. While air quality surrounding gas …

Automated Glacier Classification In High Mountain Asia Using Machine Learning And A Random Forest Classifier, Victoria Elizabeth Halvorson

Dartmouth College Master’s Theses

High Mountain Asia (HMA) is home to the largest mass of glaciers and ice outside the north and south polar regions. HMA glaciers are projected to experience accelerated mass loss from higher greenhouse gas emissions through the end of the century. Many studies of glacier mass balance and mass loss in HMA obtain glacier area from the Randolph Glacier Inventory (RGI). However, the RGI is designed to show glacier area across the world that is accurate to the year 2000 and, as a result, is not an accurate representation of the current state of glacier area in HMA. Additionally, glacier …

Impact Of Climate Change On Carbon And Nitrogen Balance In Zostera Marina L. (Eelgrass), Malee Jinuntuya

OES Theses and Dissertations

Seagrasses face vulnerability to both global stressors like Ocean Acidification (OA) and climate warming compounded by local stressors such as eutrophication that reduces light availability, leading to a complex dynamic of positive and negative effect on their growth and survival. Increased dissolved aqueous CO₂ (CO_2(aq)) benefits seagrasses by enhancing photosynthetic and growth rates, but it may increase nutrient demand, potentially depleting nutrient supply, especially in oligotrophic environments.

In this study, the long-term impact of CO₂ on Zostera marina L. (eelgrass) were investigated across a gradient of CO_2(aq) concentrations (55 – 2200 µM CO_{2(aq)) …}

Dynamic Soil-Structure Response And Failure Of Wood Utility Poles Under Hurricane-Force Wind And Non-Linear Cable Loads, Ramani Ayakannu

Civil & Environmental Engineering Theses & Dissertations

This dissertation presents the outcome of a study of the dynamic soil-structure interaction response of tapered wood utility poles embedded in various foundation soils subject to quasi-static and dynamic wind loads. The study includes the effects of nonlinear soil behavior with varying quantities of moisture and nonlinear cable tension loads on a class H1 wood pole. The natural frequency response of the pole is determined using a finite element formulation. The dynamic response in the presence of wind-induced forcing function is studied using a SAP2000 finite element scheme with wind speeds up to 220 mph. The natural frequency of the …

Advancing Depth-Storage-Discharge Modeling In Regional Hydrology, Fahad Alshehri

USF Tampa Graduate Theses and Dissertations

This dissertation presents the development of an innovative approach to populating rating characteristics and supporting hydrologic modeling, designed to simplify complex real-world hydrological systems and accurately estimate their responses to rainfall, runoff, baseflow and evaporation stresses. The core of this research addresses the challenges inherent in characterizing hydrography elements in hydrologic modeling, particularly in regions lacking comprehensive stream reach survey data, flow and stage. This issue is pronounced in areas with extensive wetland hydrography, where traditional modeling requires intensive manual calibration, and course rating data that are often unavailable. To overcome these challenges, this study introduces a novel procedure that …

Bear Lake Session, Lawrence Culver, Ben Shaw, Wesley Matthis, Mario Harper

Spring Runoff Conference

No abstract provided.

Investigation Of Gas Dynamics In Water And Oil-Based Muds Using Das, Dts, And Dss Measurements, Temitayo S. Adeyemi

LSU Master's Theses

Reliable prediction of gas migration velocity, void fraction, and length of gas-affected region in water and oil-based muds is essential for effective planning, control, and optimization of drilling operations. However, there is a gap in our understanding of gas behavior and dynamics in water and oil-based muds. This is a consequence of the use of experimental systems that are not representative of field-scale conditions. This study seeks to bridge the gap via the well-scale deployment of distributed fiber-optic sensors for real-time monitoring of gas behavior and dynamics in water and oil-based mud. The aforementioned parameters were estimated in real-time using …

Enhancing Landslide Susceptibility Modelling Through A Novel Non-Landslide Sampling Method And Ensemble Learning Technique, Chao Zhou, Yue Wang, Ying Cao, Ramesh P. Singh, Bayes Ahmed, Mahdi Motagh, Yang Wang, Ling Chen, Guangchao Tan, Shanshan Li

Mathematics, Physics, and Computer Science Faculty Articles and Research

In recent years, several catastrophic landslide events have been observed throughout the globe, threatening to lives and infrastructures. To minimize the impact of landslides, the need of landslide susceptibility map is important. The study aims to extract high-quality non-landslide samples and improve the accuracy of landslide susceptibility modelling (LSM) outcomes by applying a coupled method of ensemble learning and Machine Learning (ML). The Zigui-Badong section of the Three Gorges Reservoir area (TGRA) in China was considered in the present study. Twelve influencing factors were selected as inputs for LSM, and the relationship between each causal factor and landslide spatial development …

A Micrometeor Impact - Lake Wilson, Kansas?, Kenneth R. Neuhauser

SACAD: Scholarly Activities

Much ado about ‘nothing’ was raised when a suspect ‘object’ hit near Lake Wilson, Kansas on August 10, 2006. After a field investigation, a magnetometer survey, thin section analysis, shotgun field tests, and neutron activation analyses (NAA), no 100% conclusive physical evidence exists as to what caused the impact. However, enough NAA chemical evidence was found to suggest a micro-meteor was what created an 18” wide and 12” deep ‘crater’ at the site.

The Impacts Of Nature-Based Sediment Restoration Practices On Coastal Wetland Soil Biogeochemistry, Jacob Z. Cheng

LSU Master's Theses

Coastal marshes provide many valuable ecosystem services. However, these wetlands are threatened worldwide, being subject to sea level rise, sediment starvation, subsidence, coastal edge erosion, etc. Many efforts are being made to counteract this wetland loss and preserve the ecosystem services. Two such methods are sediment diversion and the thin layer placement (TLP) of dredged sediment.

Sediment diversion involves reconnecting the main channel of a river body to disconnected wetlands, supplying much needed soil-building materials. However, this method affects the salinity of the waters, introducing large amounts of freshwater into the system. Salinity changes can affect marsh biogeochemistry. Most ecological …

Experimental Study On Acoustic Emission Evolution Characteristics And Response Mechanism Of Damaged Rocks, Zhang Kai, Zhang Dongxiao, Zhao Yongqiang, Yang Yingming, Guo Weiyao, Sun Peng, Xu Linpeng, Fu Guangsheng

Coal Geology & Exploration

The evolution of rock internal damage is one of the causes of geotechnical engineering disasters, and revealing the response characteristics of key parameters during the rock failure could provide a basis for the identification instability state after rock failure, which is of great importance for the early warning and prevention of rock engineering disasters. Herein, the siltstone specimens with different damage degrees were prepared by cyclic loading-unloading tests, and uniaxial loading tests were carried out with the damaged specimens. On this basis, the relationship between the damage degree of specimen and the wave velocity, as well as the acoustic emission …

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.

Exploring Geological Parameters Sensitive To Underground Coal Gasification, Zhou Ze, Yi Tongsheng, Qin Yong, Zhou Yongfeng, Wang Lingxia, Kong Weimin

Coal Geology & Exploration

Compared to ground coal chemical plants, underground coal gasification (UCG) requires gasifiers as geological bodies. Accurately understanding geological conditions is a critical prerequisite for UCG. To minimize the geological risks involved in UCG siting, this study systematically explored the geological parameters sensitive to UCG based on the intricate geological conditions of Guizhou Province, China. By collecting and organizing the exploration data of coal resources in Guizhou, this study established mathematical models for normalized, graded parameter value assignment, the algorithm of parameter weight vectors, and the algorithm of parameter weight product, with the purpose of obtaining the accurate quantitative data of …

Uranium And Thorium Enrichment Characteristics Of Bauxite In Coal Measure Strata And Their Natural Gamma-Ray Responses, Zhang Xiaohui, Zhang Shangqing, Liu Dongna, Zhao Fenghua, Zhao Jun, Zhong Zhuanghua, Hou Xuqin

Coal Geology & Exploration

Shanxi Province boasts abundant bauxite resources occurring in coal measure strata, with the deep bauxite resources in this province subjected to progressive assessment. This study aims to further determine the endowment of aluminum resources within coals in the province and explore efficient exploration methods. To this end, this study investigated the bauxite layers in Upper Carboniferous coal measure strata in the Xiaoyi area, Shanxi Province. It examined 37 samples from three boreholes using methods such as optical microscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray fluorescence spectrometry (XRF), and inductively coupled plasma mass spectrometry (ICP-MS). Based on the analysis …

Law Governing Variations In Water-Pressure Transmission Rate In Confined Aquifers, Wang Wenxue, Wang Bosen, Gao Yanwei, Wu Bing, Nie Tianyu

Coal Geology & Exploration

The water pressure in aquifers is transmitted as energy, with a transmission rate much higher than the migration rate of water particles. The water-pressure transmission rate holds great significance for the safe construction and disaster forecast and prediction of underground engineering under high-pressure water aquifers and bodies. Focusing on the confined aquifers bearing no cohesive soil, this study explored the law governing the changes in the water-pressure transmission rate through theoretical analysis, numerical simulations, field experiments, and laboratory physical model tests. Key findings are as follows: (1) The transmission of water-pressure changes in the aquifers exhibited noticeable hysteresis. The transmission …

Coal-Rock Interface Imaging Based On Acoustic Remote Reflection Logging Within Crossing Boreholes Using The Finite Element Method, Xu Hongyang, Zhai Cheng, Xia Jigen, Sun Yong, Dong Xingmeng, Lai Yongshuai, Yu Xu, Xu Jizhao, Cong Yuzhou

Coal Geology & Exploration

The presence of small geological structures is the main cause of coal and gas outbursts, making the precise detection of these structures an urgent need. High-precision detection of coal-rock interfaces is essential for identifying small structures and achieving transparent mining faces. The acoustic remote reflection logging technology, with a large detection range, a high resolution, and imaging capability, can accurately identify coal-rock interfaces. In this context, this study proposed a technique for coal-rock interface detection based on acoustic remote reflection logging within crossing boreholes. Specially, by placing acoustic detectors in crossing boreholes, the array waveforms generated by the coal-rock interfaces …

Application Of The Horizontal Seismic Profiling-Based Advance Detection Technology To The Excavation Of Rock Roadways In Coal Mines Using Tunnel Boring Machines, Zhang Sheng, Chen Zhao, Lu Song, Yang Zhanbiao, Ji Panjun, He Fei, Lu Yiqiang, Liu Jiawei

Coal Geology & Exploration

With the gradual application of full-face tunnel boring machines (TBMs) to the excavation of rock roadways in coal mines, there is an increasingly urgent need for the accurate and rapid advance prediction of unfavorable geological structures. This study analyzed the characteristics of active-source seismic wave-based advance detection methods and the applicability of the advance detection technology based on TBM seismic while drilling (TSWD) with TBM rock-breaking vibration as a seismic source. Then, by combining the geological and production conditions of coal mine roadways, this study proposed a horizontal seismic profiling (HSP)-based advance detection method applicable to the excavation of roadways …

Early Warning And Prediction Of Kicks And Lost Circulation Accident During Rescue Drilling Of Mine, Chen Weiming, Wang Jiawen, Fan Dong, Hao Shijun, Zhao Jiangpeng, Qiu Yu

Coal Geology & Exploration

In order to solve the problems such as the difficulty in early warning and prediction of kicks and lost circulation accidents during emergency rescue drilling of mine, a machine learning-based early for warning and prediction model of drilling process was established. Firstly, the accident characterization parameters of the drilling parameters in the early stage of kicks and lost circulation accidents were analyzed. Secondly, the accident characterization parameters were cleaned and processed. On this basis, XGBoost and early warning model was used to carry out the early diagnosis and identification of kicks and lost circulation accidents. Then, the PSO-LSTM accident development …

Analysis On Working Characteristics Of Cam-Roller Impact Mechanism Of Rotary Percussion Drilling Tool, Sun Yangqing, Yi Xianzhong, Wan Jifang, Ma Jianqi, Wu Jiwei, Yi Jun, Yin Guangpin

Coal Geology & Exploration

Rotary percussion drilling tools can effectively improve their rock breaking efficiency in the deep and hard strata, thus having broad application prospects. The cam-roller is the key mechanism to realize the impact action, but the complex and changeable downhole environment leads to serious damage to the mechanism, which in turn affects the efficiency of rock breaking. Based on the test drilling data of rotary impact drilling tools in several wells, the cam-roller dynamics model was established, the working characteristics under different strokes, speeds and drilling pressures were analyzed by Autodyn (explicit dynamics), and the deformation characteristics of the mechanism were …

Development And Application Of An Automatic Online Testing Instrument For The Funnel Viscosity And Density Of Drilling Fluids, Xie Hui, Zheng Liqun, Liu Fulin, Liang Mengjia, Liu Xuan, Cai Jihua, Yang Xianyu, Hou Jiwu

Coal Geology & Exploration

In recent years, the research on the automatic performance testing technology for drilling fluids has achieved significant progress both domestically and internationally. However, automatic drilling fluid testing instruments face challenges, such as high costs, complicated structures, and restricted working environments. Given these challenges, this study developed an automatic online testing instrument for the funnel viscosity and density of drilling fluids. The testing instrument consists of mud pumping, testing, cleaning, and control modules, which are built using a programmable logic controller (PLC), an Internet of things (IoT) module, a pressure sensor, an ultrasonic sensor, a peristaltic mud pump, an electric ball …

Deformation And Collapse Patterns Of Gas Drainage Boreholes And A Precise Monitoring Technology, Xiao Peng, Huang Xiaosheng, Liu Xiaoxiao, Li Bingkun, Chen Liping, Chen Zixi, Zhang Chao, Cheng Renhui, Zhao Yajie

Coal Geology & Exploration

This study aims to promote the precise and intelligent monitoring of gas drainage boreholes. In the engineering background of a coal mine in Shanxi Province, this study conducted simulation experiments on the plugging of gas extraction boreholes under varying particle size ratios of simulated coal samples using distributed optical fiber monitoring and the Brillouin Optical Time-Domain Analysis (BOTDA). Then, this study established a mathematical model for calculating the borehole plugging rate of the test mine, revealing the deformation and collapse patterns of gas drainage boreholes. Furthermore, this study proposed a precise in-situ monitoring technology for the gas drainage boreholes in …

An Experimental Study Of Factors Influencing Gas Seepage In Confined Broken Anthracite, Li Zhen, Yu Yirui, Wang Hongwei, Feng Guorui, He Fulian, Wang Dezhang, Zhou Jinhui, Liu Luyan, Han Xinlei

Coal Geology & Exploration

The void structure evolution of broken coals in a caving zone directly affects the gas seepage characteristics of the zone, further influencing the gas migration and enrichment patterns in abandoned coal mine goaves. With the second generation of compaction-seepage-CT scanning experimental system for broken coals independently designed and developed, this study performed 162 sets of permeability experiments on broken anthracite samples with five particle size ranges under varying gas pressures, axial stresses, and void fractions. Key findings are as follows: (1) When gas migrated in broken anthracite, its pressure and flow rate kept dynamically changing until the adsorption equilibrium was …

Positioning Error Compensation Of Drilling Robot Arm For Coal Mine, Liang Chunmiao, Yao Ningping, Yao Yafeng, Peng Tao

Coal Geology & Exploration

At present, the pose of drilling robots is mostly adjusted by manual remote control and manual retest in combination. Full automatic adjustment has not been achieved. Besides, due to the low precision of open-loop control and inadequate automation capability, the accurate hole positioning and automatic construction of hole groups cannot be realized by drilling robots with water exploration and discharge, outburst prevention and punching prevention in coal mines. Herein, the kinematic model of drilling arm was established by analyzing the structure and action of the drilling robot’s drilling arm. Meanwhile, the dip angle factors such as machining error, body deformation …

Operation Process Identification For Intelligent Drill Rig Base On Analytic Hierarchy Process, Zhu Qianxiang, Luo Pengping, Wang Longpeng, Xing Wang, Wang Tianlong

Coal Geology & Exploration

It is very difficult to automatically identify the current process during the intelligent construction of coal mine drill rigs. In response to this, an operation process identification method was proposed, which includes hierarchical modeling of drill rig operation and probability inference of process execution. Firstly, the coupling process among the components of different granularity during the operation of drill rig is described and modeled based on the hierarchical analysis method, which reveals the interactive characteristics between equipment, function and system during the execution of each process. Secondly, Bayesian probabilistic reasoning method is introduced based on the above research to establish …

A Method For Coal Seam Pressure Relief Based On Steel Cone Impact, Ren Zhimin, Lyu Mengjiao, Wang Fei, Wang Yu, Zhang Guangtai

Coal Geology & Exploration

This study aims to solve the mining safety problems caused by rock bursts in coal mines. With the geological mining conditions of the No.3 coal seam in the Wulihou coal mine in Zuoquan County, Jinzhong City, Shanxi Province as the engineering background, this study proposed a method for coal seam pressure relief based on steel cone impact. Specifically, based on the electromagnetic repulsion generated between energized coils, this study derived the functions of impact force produced when a magnetically driven coil-wound steel cone impacted the coal seam. Combining the theory on elastic mechanics, this study analyzed the stress field distribution, …

Two-Phase Flow Chokeling Results And Control In High-Pressure Gas Wells Producing Water, Liu Xinfu, Liu Chunhua, Li Qingping, Yao Haiyuan, Hao Zhongxian, Liu Yongfei

Coal Geology & Exploration

Prediction and control of two-phase flow chokeling in tight gas wellbores are essential for the normal operation and hydrate control of high-pressure gas wells producing water. The thermodynamic differential equations of energy, kinetic energy and temperature and models of chokeling field for two-phase energy, system heat, mass balance and flow were developed under the conditions of isentropic adiabatic, isobaric heat capacity, constant volume heat capacity, and chokeling energy. A methodology on predicting characteristics and control of two-phase flow before and after chokeling was proposed for gas-water two phase flow. It provided a theoretical basis for optimizing the structural parameters of …

High-Accuracy Reconstruction Of Missing Ground-Penetrating Radar Signals Based On Projection Onto Convex Sets In The Curvelet Domain, Wu Qiming, Wang Honghua, Xi Yuhe, Wang Yucheng

Coal Geology & Exploration

Influence by the acquisition environments and instrument performance, missing signals and destructed channels are inevitable in measured ground-penetrating radar (GPR) profiles. They can cause event discontinuity of reflected and diffracted waves generated by targets, severely impairing the accuracy and resolution of subsequent processing and imaging. Hence, by combining the projection onto convex sets (POCS) algorithm extensively used in image processing with the curvelet transform exhibiting high sparsity, this study proposed a high-accuracy reconstruction method for missing GPR signals based on curvelet-domain POCS. Building on the compressive sensing theory, the objective function for missing signal reconstruction based on discrete curvelet transform …