Digital Commons Network^™

Application Of Floating Wetlands To Improve Urban Stream Quality, Daniel Chukwunonso Chukwudi

Theses and Dissertations

Urban streams, impacted by urbanization, often exhibit degraded water quality due to elevated nutrient levels, a phenomenon known as urban stream syndrome. This study evaluates the effectiveness of a floating wetland (FW) system in reducing nitrate as nitrogen (NO₃-N) and phosphate (PO₄³⁻) concentrations in a side canal of the Chicago River’s North Branch, adjacent to Goose Island, Chicago, IL, from 2018 to 2023. Using a five-year dataset, including new sampling from May to December 2023, the research addresses two questions: (1) Do FWs lower NO₃-N and PO₄³⁻ concentrations in urban streams? and (2) Do FWs exhibit seasonal differences in nutrient …

Multi-Source Remote Sensing–Based Soil Moisture Prediction Using Machine Learning, Niraj Neupane

Electronic Theses and Dissertations

Soil moisture (SM) plays a central role in climatic and environmental processes, influencing shear strength of soil, agricultural productivity, land–atmosphere interactions, and hydrologic functioning. However, accurately estimating SM across diverse climatic regions remains challenging due to spatial heterogeneity, limited in situ measurements, and inconsistencies in sensor resolution. Machine learning (ML) and remote sensing offer promising avenues for improving SM prediction, yet many existing approaches struggle with generalization across climatic gradients and often fail to capture temporal variability. This study integrates multi-source satellite and climate datasets, including SMAP L4_SM, MODIS land surface temperature, Daymet meteorological variables, and in situ observations from …

Proximal Seismic Tracking Of Pyroclastic Density Currents At Volcán De Fuego, Guatemala, Jacob A. Krier

Dissertations, Master's Theses and Master's Reports

Pyroclastic Density Currents (PDCs) are deadly flows of ash, tephra, gas, and solidified magma which predominantly occur when an ash plume collapses during a volcanic eruption. PDCs are also able to form when large deposits of ash at the summit of a volcano are displaced during an eruption and flow downslope. This is typically the mechanism behind PDCs that occur at Volcán de Fuego such as one that occurred in 2018 killing at least 430 people. The purpose of this paper is to track the propagation of PDCs that occurred at Fuego seismologically in order to better understand how they …

Provenance Of The Uppermost Carboniferous–Lower Triassic Sandstones, Bogda Mountains, Nw China: Implications On The Late Paleozoic Tectonic History Of The Southern Central Asian Orogenic Belt, Sixuan Wu

Doctoral Dissertations

"The Permian-Triassic period represents a significant but insufficiently understood tectonic transition stage in the southern Central Asian Orogenic Belt (CAOB) between the Paleozoic continental amalgamation and Cenozoic orogenic reactivation. This study integrates fieldwork, petrographic, and detrital zircon geochronological data to document the trend of depositional environments, framework grain compositions, and dates of detrital zircon grains of the uppermost Carboniferous–Lower Triassic sandstones from three study areas in Bogda Mountains, the greater Turpan-Junggar basin, NW China, to decipher the spatial and temporal changes in the provenance lithology and area and reconstruct the unroofing history of the southern CAOB.

In the first part …

Evaluation Of Practical Methods To Determine If A Karst Creek Is Gaining Or Losing: Case Study Of Leith Creek, Elizabeth Jones

Graduate Theses/Dissertations

Karst landscapes are abundant in Missouri, with features such as caves, springs, and sinkholes that form through the dissolution of limestone. Leith Creek is a small stream in Polk County, Missouri fed by two springs and the shallow unconfined Springfield Plateau aquifer, a highly karstified aquifer which is made up of limestone and minor interbedded shale-mudstone units. To determine if Leith Creek is gaining or losing, stream flow, water chemistry and temperature sensors were monitored. Stream flow results required multiple visits to take measurements while temperature sensors required two visits, one to install the dataloggers and another to remove the …

Fluvial Geomorphic Resilience In Alluvial Mountain Rivers To Large Floods, Riley T. Henson

Graduate Student Theses, Dissertations, & Professional Papers

As hydroclimatic extremes intensify, large floods increasingly reshape river systems and threaten infrastructure. Fluvial geomorphic resilience, defined as a river’s resistance to, and recovery from, flood disturbance, offers a useful framework for understanding river response and guiding management. We assessed resilience at two scales: (1) a detailed geomorphic and hydraulic analysis of the June 2022 flood on East Rosebud Creek, Montana, which was part of broader flooding in the Greater Yellowstone Ecosystem, and (2) a broad-scale comparison of 12 flood-impacted alluvial mountain rivers across North America and Europe. We quantified resistance using active channel width ratios (W_R) and …

Impacts Of Fire-Driven Vegetation Changes On Evapotranspiration In North American Boreal Forests, Tyler Glen Albrethsen

Graduate Student Theses, Dissertations, & Professional Papers

A growing body of evidence suggests that land cover change could be impacting evapotranspiration (ET) trends more than the direct impacts of climate change (Dashti et al., 2022; Zhang et al., 2015). In boreal forests, one of the Earth’s most important carbon sinks (Kang et al., 2006), climate and disturbance-driven land cover change is progressing rapidly, threatening the resilience of conifer-dominated forests (Baltzer et al., 2021; Massey et al., 2023). The spread of deciduous trees and the changing structure of boreal forests likely have large implications for the magnitude and seasonality of ecosystem water fluxes (Young-Robertson et al., 2016). This …

Evaluation Of Soil Erosion In The Middle Yom River Basin, Passapong Paentong

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study aims to assess soil erosion in the Middle Yom River Basin and analyze the spatial relationships between erosion and its influencing factors using the Revised Universal Soil Loss Equation (RUSLE) in combination with Ordinary Least Squares (OLS) regression analysis. The analysis considers five principal RUSLE factors: rainfall erosivity (R), soil erodibility (K), topography (LS), cover management (C), and support practices (P), under both normal and heavy rainfall scenarios for the years 2010, 2015, and 2020. The results indicate that under normal rainfall conditions, most areas experienced low to moderate soil loss (0–5 tons/rai/year). Under heavy rainfall conditions, the …

A Hybrid Method For Source Direction Finding With Radio Frequency Interference And Gaussian White Noise, Yanming Zhang, Wenchao Xu, Antonios Argyriou, A. Long Jin, Tianquan Tang, Peifeng Ma, Lijun Jiang, Steven Gao

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents a hybrid data-driven method, termed moving average-Hankel-dynamic mode decomposition (MAHankDMD), for joint direction of arrival (DOA) and frequency estimation in environments affected by both radio frequency interference (RFI) and Gaussian white noise. The proposed approach integrates two key components: (1) a moving average-DMD filter that effectively mitigates Gaussian white noise and separates RFI from the source signal, and (2) a Hankel-DMD method that accurately estimates the DOA of the filtered signal and associates it with the corresponding frequency. The moving average-DMD stage first enhances the signal-to-noise ratio and improves the robustness of the estimation process through noise …

Evaluating The Causes Of Land Subsidence On The U.S. Mid-Atlantic Coast Measured With Insar, Jordan Leigh Diprima

Honors Theses and Capstones

Land subsidence is a frequently overlooked geologic hazard that is caused by natural processes and anthropogenic stressors. The goal of this study is to quantify vertical land motion (VLM) on Long Island, New York and Virginia’s Eastern Shore and evaluate the potential causes of subsidence. The causes considered in this work are glacial isostatic adjustment, groundwater extraction, infrastructure loading, and land cover. This study utilizes interferometric synthetic aperture radar (InSAR) satellite data from Sentinel-1 to calculate linear VLM trends from 2017 to 2023. Datasets for each hypothesis were qualitatively compared to VLM data. Subsidence rates in both regions were found …

Unfolding Cascading Impacts Of Changing South Asia Monsoon On A Hindu Kush Himalayas Basin, Surendra Maharjan, Wenzhao Li, Shahryar Fazli, Arshad Ansari, Suraj Tiwari, Roma Thakurathi, Rejoice Thomas, Hesham El-Askary

Mathematics, Physics, and Computer Science Faculty Articles and Research

Study region

Study focus

New hydrological insights for the region

Cropsync: Ai-Powered Sustainable Crop Management, Ziad Doughan, Ibrahim Mneimneh, Zouheir Nakouzi, Noor Al Khaib, Samer Damaj, Jamal Chaaban, Hamza Mrad, Sari Itani

BAU Journal - Science and Technology

CropSync is a smart agriculture system that uses AI and IoT technologies to enable sustain- able crop management and precision farming. The system aims to address the challenges faced by the agriculture sector, such as increasing food production to meet global population demands while minimizing environmental impact. CropSync integrates sensors, cameras, and cloud-based analytics to provide farmers with real-time insights and recommendations for optimizing crop cul- tivation. The system upholds engineering professional and ethical standards, considering broader social, environmental, and economic implications. From a social perspective, CropSync improves food security and enhances farmers’ livelihoods through increased productivity and efficient re- …

Coal Gasification Through Microbial Degradation In A Low-Pressure Co2 And H2 Environment: An Experimental Study, Jian Kuo, Fu Xuehai, Liu Mingjie, Liu Jian, Li Jin, Ru Zhongliang, Ji Xiaofeng, Wang Qiang

Coal Geology & Exploration

Objective and Methods This study aims to investigate the characteristics of CO₂ biomethanation and coal gasification through microbial degradation in a low-pressure environment. With low-rank bituminous coals (R_max = 0.67%) as fermentable substrates, this study conducted a 96-day gas production experiment through microbial fermentation in a low-pressure CO₂ and H₂ environment. Using techniques including gas chromatography, 16S rRNA gene sequencing, and low-temperature liquid nitrogen adsorption, this study delved into the intrinsic variation patterns of biogenic gas production, microbial communities, and coal structures. Results and Conclusions The results indicate that compared to conventional fermentation, the injection …

Predicted Water Yield Of Open-Pit Metal Mines Based On A Bi-Rnn And Gms Coupling Model, Zhao Yuxing, Li Xiangwen

Coal Geology & Exploration

Objective Accurately predicting water yield of mine before mining can provide directive guidance for preventing potential water hazards and ensuring safe production. Methods To enhance the prediction accuracy and stability of water yield of open-pit metal mines, for which atmospheric precipitation acts as the primary recharge source of water, this study developed a prediction model that coupled a bidirectional recurrent neural network (Bi-RNN) and the Groundwater Modeling System (GMS) software. Specifically, based on historical forecasted precipitation data provided by the Global Forecast System (GFS), the fluctuation pattern of differences between predicted forecasted and actual precipitation was analyzed. After being corrected …

An Experimental Study Of The Application Of The Spectral Acoustic Method To The Advance Detection Of Geologic Structures In Tunnelling Working Site, Zhang Jianguo, Feng Zhicheng, Wei Fengqing, Ma Ji, Zhao Kai, Wang Man, Guo Minggong, Шилов Владимир Иванович

Coal Geology & Exploration

Objective The practice of coal mine production has proved that the vast majority of coal and gas outbursts are controlled by geological structures, and mainly occur in tunnelling working site. Therefore, continuous advanced detection of geological structures is an important technical means to prevent and control coal and gas outbursts in tunnelling working site, and is of great significance to ensure safe production in mines. Methods Based on the research results of spectral acoustic method in Russia for many years, the resonance phenomenon generated at the weakened contact surface of the roof rock layer by the artificial acoustic signal excited …

Application Of Microseismic Monitoring In The Optimization Of Control Strategy For Roofs Composed Of Composite Hard Sandstone Masses, Zhang Yin, Li Jiajun, Zhao Qian, Yang Chenchen, Liu Jiaqi, Zhou Yu

Coal Geology & Exploration

Objective With a gradual increase in the coal mining depth in China, the movement of overlying thick and hard rock layers exerts increasingly complex impacts on the mine pressure. Methods In the Ordos area, the overburden of the mining face of most mines hosts composite hard sandstone masses, serving as key layers characterized by considerable thicknesses, high hardness, and close proximity. Results and Conclusions As a result, the risks of mine earthquakes and dynamic manifestation co-exist in the mining face. With the roof of mining face11-3106 in a coal mine within the Ordos mining area as the engineering background, this …

A Dc-Unet-Based Image Processing Method For Detecting Fractures Along Roadway Sections Of Coal Mines, Dong Zheng, Zhang Xuhui, Yang Wenjuan, Kang Le, Tang Duwei, Tian Chenhui

Coal Geology & Exploration

Objective Detecting fractures along roadway sections of coal mines allows for the characterization of the geologic conditions of roadways, thus providing guidance for roadway tunneling and support engineering. However, conventional image processing methods for fractures along roadway sections are susceptible to complex environments in underground coal mines, exhibiting a low fracture detection efficiency. Methods This study proposed a novel image processing method for detecting fractures along roadway sections based on a DC-UNet model. This method can be deployed on a mobile terminal and an embedded device, thereby allowing for real-time and effective detection of fractures along roadway sections and enhancing …

Development Of A Power Recovery-Based Dynamic Loading System For Full-Size Drill Rods In Coal Mines, Zhang Jing, Wang Jie

Coal Geology & Exploration

Objective This study aims to simulate the actual forces applied to drill rods during the borehole drilling for gas drainage from underground coal mines to satisfy the requirements of drill rods’ fatigue tests. Methods This study designed a dynamic loading system for full-size drill rods in coal mines. This system consists of a drill rod loading platform, a hydraulic pump unit with power recovery, and a measurement and control system, allowing for the composite loading of dynamic torque, axial force, and radial displacement on drill rods of different specifications. In this system, torque is loaded to drill rods using the …

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.

Failure Depths Of Stope Floors Under Dynamic Loading Induced By Roof Breaking, Huang Qisong, Xu Bo, Feng Junjun, Lin Xiaofei, Cheng Jiulong, Peng Jun

Coal Geology & Exploration

Objective Accurately assessing the failure depths of stope floors is crucial for assessing floor water inrush risks. Conventional theoretical models for calculating the failure depths generally merely consider static loads from the support pressure and confined water's pressure in stopes, leading to large deviations between calculation results and actual situations. Therefore, constructing a more practical computational model that comprehensively considers the coupled effects of multiple force sources on the failure of deep floors can provide a scientific basis for the effective prevention and control of water hazards in deep coal seam floors. Methods Based on the dynamic elasticity theory and …

Construction And Correction Of A 3d Digital Twin For A Complex Gangue-Bearing Coal Seam, Zhang Meichen, Zhao Lijuan, Wang Yadong, Zhang Kai

Coal Geology & Exploration

Objective 3D digital twin for complex gangue-bearing coal seams are designed to achieve an information-based description of physical coal seams and faithfully map their virtual forms. digital twin is identified as a prerequisite for exploring the efficient cutting of intelligent shearers while providing an effective data guarantee for achieving unmanned mining. Methods Using data on samples from the mining face of coal seam 17 in the Yankuang Energy Group Co., Ltd. Shandong Province, this study proposed a methodology that integrates more information about the geological structural conditions of coal seams. Specifically, digital twining of iron sulfide nodules was performed using …

Influence Mechanisms Of Dynamic Metamorphism On The Evolution Of Micro/Nano Pore Structures In Tectonically Deformed Coals, Liu Hewu, Lyu Xiaoxue, Hou Chenliang, Xiong Zuopeng

Coal Geology & Exploration

Objective Micro/nano pore structures in coals act as a significant space for gas occurrence. Exploring the evolutionary mechanisms of micro/nano pore structures in tectonically deformed coals (TDCs) under the influence of dynamic metamorphism assists in gaining a deep understanding of the mechanisms underlying coal and gas outbursts. Methods Using CO₂ adsorption experiments, Fourier transform infrared (FTIR) spectroscopy, and molecular dynamics simulations, this study investigated the evolutionary characteristics and mechanisms of micro/nano pore structures in different TDCs occurring within the No.72 coal seam of the Qi’nan Coal Mine in Suzhou Province. Results and Conclusions The results indicate that with enhanced …

Mechanisms And Influential Factors Of Rock Bursts In Tunneling Roadways Of Extra-Thick Coal Seams, Peng Yujie, Wang Qiang, Cao Anye, Xue Chengchun, Lyu Guowei, Hao Qi, Liu Yaoqi, Bai Xianxi, Li Dong

Coal Geology & Exploration

Objective Rock bursts occur frequently in tunneling roadways of extra-thick coal seams, significantly constraining safe coal mining. Investigating their mechanisms and influential factors is crucial to preventing and controlling such disasters in tunneling roadways of extra-thick coal seams. Methods Focusing on the tunneling roadway of mining face 250107-1 for an extra-thick coal seam within a coal mine in Gansu Province, this study established the discriminant indices for rock burst-induced roadway instability. By simulating the energy distribution patterns of surrounding rocks in the tunneling roadway using the FLAC^3D software, this study revealed the zonal energy characteristics of the surrounding rocks …

A Calculational Model For 3d Fault Complexity Based On Curvature Analysis And Fractal Dimensions, Yan Junsheng, Liu Zaibin, Fan Tao, Yang Hui, Liu Wenming, Du Wengang, An Lin, Liu Chenguang, Wang Xiaohui

Coal Geology & Exploration

Objective and Methods Faults are identified as one of the most threatening geological structural factors among hidden disaster-causing factors in coal mines. However, the 3D quantitative assessment of them remains challenging. Considering that existing quantitative indicators fail to fully reflect fault morphologies and there is a lack of 3D methods, this study proposed a calculational model for 3D fault complexity based on curvature analysis and fractal dimensions. This model improved the morphologies of traditional measurement volumes of fractal dimensions by employing the Delaunay tetrahedralization algorithm, thus effectively reducing the invalid values in calculating the 3D fractal dimensions of faults. Moreover, …

Exploration Of The Impacts Of Cement Sheath On Casing Stress Based On The Arching Effects Of Formations, An Fengchen, Miao Zhibo, Meng Siwei, Wei Ziying, Zhang Xiao, Zeng Jiaming, Wang Xiaohua

Coal Geology & Exploration

Objective With the growth in the demand for natural oil and gas and the technological progress of their production, the oil and gas well depths have been constantly setting new records. The increase in the depth corresponds to sharply increasing in-situ stress, leading to increasingly severe damage to the casing of ultradeep oil and gas wells. To enhance the bearing capacity of the casing under high in-situ stress, high-strength casing with a large wall thickness is typically employed, a measure which has been proved, however, less effective. Methods This study established a finite element model of the casing-cement sheath-formation system …

Commingling Production Of Deep Coal-Measure Gas Through Hydraulic Fracturing: Propagation Patterns Of Induced Fractures And Their Determinants, Chen Hao, Li Guozhang, Qin Yong, Wang Jianguo, Shen Jian, Sun Yuqi, Yuan Erjun, Li Dian

Coal Geology & Exploration

Objective The commingling production of coal-measure gas represents a pivotal approach to enhancing the single-well production of unconventional gas in China. However, coal-measure gas reservoirs exhibit distinctly different material compositions and physical properties, leading to uncertainty of the propagation modes and developmental degrees of fractures in different reservoirs during the hydraulic fracturing of coal-measure gas reservoirs subjected to commingling production. Therefore, effectively coordinating the stimulation of multiple reservoirs for multi-gas commingling production is crucial for minimizing production costs and maximizing production capacity. Methods This study investigated the Linxing block along the northeastern margin of the Ordos Basin as an example …

Application Of D-Insar In Monitoring The Impacts Of Shaft Grouting On Surface And Building Deformations, Liu Hui, Lu Rumeng, Su Lijuan, Cheng Shiguang, Zhang Pengfei, Cheng Hua

Coal Geology & Exploration

Objective In coal mining engineering, damaged well walls pose a threat to the safety of production facilities and mines. Comprehensively monitoring the impacts of shaft grouting on the deformations of mine surface plants and surface buildings is critical for ensuring the safe production of mines. Methods This study investigated a coal mine in the mining area within northern Anhui Province. Using the 15 scenes of Sentinel-1A image data covering the coal mine and the differential interferometric synthetic aperture radar (D-InSAR) technology, this study comprehensively monitored the subsidence of mine surface plants and surface buildings before and after shaft grouting, obtaining …

Fracture Structure Of The Overburden In The Layered Mining Of Extremely Thick Coal Seams: Developmental Patterns Of Caving Zones And Hydraulically Conductive Fracture Zones And Fracture Characteristics, Zhang Xin, Chen Youkuo, Meng Hailun, Qin Qifa, Cheng Xianggang, Huang Rongjie, Dong Hairui, Sun Wenbin, Qiao Wei

Coal Geology & Exploration

Objective The Zhunnan Coalfield, a coalfield on the southern margin of the Junggar Basin in Xinjiang, boasts abundant coal resources. However, water hazards in mines severely constrain the safe and efficient coal production in the coalfield. Since hydraulically conductive fractures in roofs serve as primary hydraulically conductive channels formed in the mining of the mining face, it is particularly crucial to investigate the developmental patterns of these fractures during the layered mining of extremely thick coal seams. Methods This study explored the (9-15)08 mining face of the Liuhuanggou Coal Mine in Xinjiang. Using ground exploration holes and borehole televiewers, this …

Hydrochemical Characteristics And Component Sources Of Water In Underground Reservoirs In The Daliuta Coal Mine, Zhang Haitao, Jiang Binbin, Zhang Haiqin, Li Peng, Wu Min, Hao Jingwei, Hu Yutian

Coal Geology & Exploration

Objective Underground reservoirs in coal mines are capable of storing and purifying mine water. A deep understanding of the hydrochemical characteristics and formation mechanisms of water in underground reservoirs is identified as an important prerequisite for large-scale development of technologies for mine water treatment. Methods This study investigated the underground reservoirs in the Daliuta Coal Mine within the Shendong area by testing and analyzing their influent and effluent water samples. Using methods such as the ion ratio method, multivariate statistical analyses (e.g., correlation analysis and principal component analysis (PCA)), and the positive matrix factorization (PMF) model, this study delved into …

Microscopic Fracture Characterization And Permeability Evolutionary Patterns Of Granites Under Cyclic Thermal Shock, He Jiangfu, Ren Chengcheng, He Kun, Yu Qihang, Li Xinru, Deng Xu

Coal Geology & Exploration

Objective This study aims to reveal the microscopic damage characteristics and permeability evolutionary patterns of high-temperature granite reservoirs fractured under cyclic thermal shock produced by low-temperature fluids like drilling fluids and circulating heat recovery media in the exploitation process of the enhanced geothermal systems (EGSs). Methods Using experiments on the fracturing characteristics of high-temperature granites under the conditions of varying cooling methods, numbers of thermal shock cycles, and cooling temperatures, this study determined microstructural characteristic parameters such as compressional wave (P-wave) velocity, pore volumetric fraction, and fractal dimension of granites across a temperature range of 25 to 700 ℃ under …