Digital Commons Network^™

Revisiting The Chronology Of Loess In North America By Using Sar-Osl And Pirir Protocols, Anca Avram

FRONTIERS UNBOUND: Exploring Extreme Environments

No abstract provided.

Preliminary Analysis Of Quartz Using Scanning Electron Microscopy Techniques, Serban Constantin Grecu, Alida Timar-Gabor

FRONTIERS UNBOUND: Exploring Extreme Environments

No abstract provided.

The Ecosystem Of A Remarkable Glaciovolcanic Cave At Mount Meager, British Columbia, Canada, Christian Stenner, Kathleen Graham, Morgan Cable, Glyn Williams-Jones, Jared J. Clance, Jacob Shaffer, Jill Mikucki, Anna Szynkiewicz, Olivia Vinnes, Michael Paton, Jeremy Nash

FRONTIERS UNBOUND: Exploring Extreme Environments

No abstract provided.

Big Geospatiotemporal Data Approaches To Monitoring And Mitigating Environmental Impacts In Agriculture, Olatunde D. Akanbi, Vibha S. Mandayam, Erika I. Barcelos, Arafath Nihar, Yinghui Wu, Jeffrey Yarus, Roger H. French

Student Scholarship

This research explores the application of geospatial techniques for global agricultural monitoring, integrating satellite imagery and soil data to assess crop health and soil conditions. Our approach provides actionable insights to improve agricultural productivity and sustainability, addressing food security challenges through advanced machine learning models.

Supplementary Files For "Impact Of Snow Accumulation On Structural Integrity: Present And Future Perspectives", Kenneth Pomeyie, Brennan Bean

Browse all Datasets

Evaluating the impact of weight exerted by settled snow (i.e., snow load) on structures poses numerous statistical challenges, including missing data, biased distribution parameters, and the influence of climate change. This dissertation aims to address challenges related to the use both direct and indirect measurements of snow load (or equivalently, snow water equivalent), as well as the anticipated impact of climate change on future extreme snow loads. The first paper within this dissertation investigates short-term snow loads by comparing various techniques for estimating extreme values of short-term snow accumulations. Additionally, the first paper includes a comparative analysis of short-term and …

Scientific History, Sampling Approach, And Physical Characterization Of The Camp Century Subglacial Material, A Rare Archive From Beneath The Greenland Ice Sheet, Paul R. Bierman, Andrew J. Christ, Catherine M. Collins, Halley M. Mastro, Juliana Souza, Pierre Henri Blard, Stefanie Brachfeld, Zoe R. Courville, Tammy M. Rittenour, Elizabeth K. Thomas, Jean Louis Tison, François Fripiat

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Basal materials in ice cores hold information about paleoclimate conditions, glacial processes, and the timing of past ice-free intervals, all of which aid understanding of ice sheet stability and its contribution to sea level rise in a warming climate. Only a few cores have been drilled through ice sheets into the underlying sediment and bedrock, producing limited material for analysis. The last of three Camp Century ice cores, which the U.S. Army collected in northwestern Greenland from 1963-1966 CE, recovered about 3.5 m of subglacial material, including ice and sediment. Here, we document the scientific history of the Camp Century …

Nitrate Removal By Floating Treatment Wetlands Under Aerated And Unaerated Conditions: Field And Laboratory Results, Jenna Mccoy, Matt Chaffee, Aaron Mittelstet, Tiffany L. Messer, Steve Comfort

Earth and Environmental Sciences Faculty Publications

Urban and storm water retention ponds eventually become eutrophic after years of receiving runoff water. In 2020, a novel biological and chemical treatment was initiated to remove accumulated nutrients from an urban retention pond that had severe algae and weed growth. Our approach installed two 6.1 m × 6.1 m floating treatment wetlands (FTWs) and two airlift pumps that contained slow-release lanthanum composites, which facilitated phosphate precipitation. Four years of treatment (2020–2023) resulted in median nitrate-N concentrations decreasing from 23 μg L−1 in 2020 to 1.3 μg L−1 in 2023, while PO4-P decreased from 42 μg L−1 to 19 μg …

Open Groundwater Drains In Wa, Department Of Primary Industries And Regional Development, Western Australia

Natural resources factsheets

Open groundwater drains are excavated channels with sloping floors and sides and open levees, designed to intercept and drain surface (usually fresh) and groundwater (usually saline in WA) from agricultural land. These drains are most effective where the channel is dug below a water table in soils that allow good lateral drainage.

DPIRD recommends leveed groundwater drains in most cases. These should form part of a whole farm and whole catchment integrated water and salinity management program. Information on this page is a guide only. It is highly recommended that landholders considering the construction of open drains seek expert advice …

Coastal Flood Risk In The Context Of Climate Change And Urbanization In Northeastern South Carolina, Hongyuan Zhang

Electronic Theses and Dissertations

Researchers and the public now widely recognize the seriousness of coastal flood risks. Various changes in natural processes, such as altered rainfall patterns, increased tropical cyclone intensities, and sea-level rise, are consequences of global warming induced by heightened greenhouse gas concentrations. To comprehensively understand coastal compound flooding, it is crucial to consider multiple processes and their interactions. Moreover, the growth of coastal cities and the concentration of people and assets in these areas make them increasingly vulnerable to flooding events. Accurately estimating the future flood risks faced by coastal communities necessitates addressing the compounding effects on coastal flood risk, taking …

Investigation Of Temperature, Solution Strength, And Applied Stress Effects On Cation Exchange Processes In Different Geosynthetic Clay Liner Products, Kendra Fuller

Master's Theses

An extensive laboratory test program was conducted to analyze and compare the cation exchange processes in three different varieties of sodium bentonite (Na-B) geosynthetic clay liners (GCLs) over increased conditioning durations up to 32 days and investigate the effects of temperature, solution strength, and applied stress. The goal of this test program was to establish whether the variables of temperature, solution strength, and applied stress improved or degraded the engineering properties of GCLs in laboratory testing and municipal solid waste (MSW) landfill applications. The GCLs were conditioned in liquids of increasing ionic strength, using deionized water and 2, 50, and …

Regiongrow3d: A Deterministic Analysis For Characterizing Discrete Three-Dimensional Landslide Source Areas On A Regional Scale, Nicolas W. Mathews, Ben A. Leshchinsky, Benjamin B. Mirus, Michael J. Olsen, Adam M. Booth

Geology Faculty Publications and Presentations

Regional-scale characterization of shallow landslide hazards is important for reducing their destructive impact on society. These hazards are commonly characterized by (a) their location and likelihood using susceptibility maps, (b) landslide size and frequency using geomorphic scaling laws, and (c) the magnitude of disturbance required to cause landslides using initiation thresholds. Typically, this is accomplished through the use of inventories documenting the locations and triggering conditions of previous landslides. In the absence of comprehensive landslide inventories, physics-based slope stability models can be used to estimate landslide initiation potential and provide plausible distributions of landslide characteristics for a range of environmental …

Enhancing Community Flood Resilience By Incorporating Landscape Hydrological Sensitivity And Connectivity, Wenlong Feng

Dissertations

Rapid urban expansion and dramatic climate change have significantly increased the intensity and frequency of floods worldwide. With rising flood risks, conventional flood defense strategies that rely on structural measures become ineffective. The present designations for flood-prone areas, such as FEMA's flood maps, are becoming unreliable. Flood risk management is shifting toward enhancing community flood resilience, highlighting the importance of non-structural approaches. Landscape resilience has become a foundation of community flood resilience. However, past urban development typically undermined natural hydro-ecological functions and landscape resilience because of poor recognition of landscapes' ecological role, hydrological sensitivity, and hydrological connections. This study aims …

Temporal Dynamics Of Coastal Sediment Characteristics: A Comparative Study On Pre- And Post-2004 Tsunami Event Along The Nagoor - Poompuhar Stretch, Tamil Nadu, Yamini S

Theses and Dissertations

Tsunamis represent some of the most devastating natural events for coastal regions, as exemplified by the 26th December 2004 Great Indonesian Earthquake triggered a massive tsunami across the Bay of Bengal and Indian Ocean, causing extensive destruction in various countries, including India. This study addresses a significant gap in the literature by focusing on the detailed sedimentological aspects of coastal dynamics. Specifically, it examines the pre-tsunami (December 2004), post-tsunami (January 2005), and recent (December 2022) sediment characteristics along a 35 km stretch of the Coromandel coast from Poompuhar to Nagoor.

Eight stations were selected for sampling: Poompuhar, Chinnankudi, Kuttyandiyur, Chandrapadi, …

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.

Critical Drilling And Completion Techniques For Deep Coalbed Methane In The Shenfu Block And Their Applications, Wang Peng, Li Bin, Wang Kunjian, Zhang Hongjie, Zhang Yingchun, Du Jia, Zhang Linqiang, Wang Xiaoqi, Su Haiyan, Chen Guanghui, Yang Ruiyue

Coal Geology & Exploration

Objective Deep coal seams exhibit high in-situ stress, moderate to high temperatures, ultra-low permeability, high compressibility, and significant heterogeneity, leading to the absence of mature technical systems for their exploitation presently. The complex geological characteristics of deep coal seams pose new technical challenges to their drilling and completion engineering, rendering it urgent to tackle theoretical and technical challenges in drilling and completion tailored to the geological characteristics of deep coal seam reservoirs. The purpose is to achieve the reserve growth and production addition of hydrocarbons in order to guarantee China’s strategic energy security. Methods Based on the pilot tests for …

Optimization Of Schemes For Multi-Reservoir Commingled Fracturing Of Coal Measures In The Linxing Block, Wang Bo, Zhang Bing, Mi Honggang, Du Jia, Duan Jiajia, Cui Shuhui, Zhang Haozhe, Fu Tianyu

Coal Geology & Exploration

Objective The coal-bearing strata in the Linxing block on the eastern margin of the Ordos Basin exhibit the alternating occurrence of multiple sequences and vertical thin layers (interlayers). Therefore, multi-reservoir commingled fracturing is essential for the cost-effective, efficient exploitation of coal-measure gas from these coal-bearing strata. The key to successful multi-reservoir commingled fracturing is the achievement of expected fracture heights. The current challenges include the unclear vertically extended distance and morphologies of fractures, along with great deviations between the predicted and actual fracture heights, significantly affecting the volume of reservoirs for production growth. Methods Based on the in-situ stresses on …

Fracturing Characteristics And Instability Modes Of Deep Primary Coal-Rock Combinations Under Triaxial Compression, Li Chunyuan

Coal Geology & Exploration

[Objective] Deep coal-bearing strata contain primary interfaces and layered composite structures. Under the mining disturbance, the fracturing and instability of the primary composite structures of layered coal-rock combinations prove to be a principal cause of disasters such as water inrushes. [Methods] This study aims to explore the impacts of the structures of deep primary coal-rock combinations on the stability of layered rock masses during coal mining. Using fracturing tests under triaxial compression and CT-based reconstruction conducted in the laboratory, this study determined the fracturing differences between deep primary coal-rock combinations and single coal or rock masses. Based on the analyses …

A Non-Uniform Interpolation Method For Seismic Data Based On A Diffusion Probabilistic Model, Chen Yao, Yu Siwei, Lin Rongzhi

Coal Geology & Exploration

Objective The non-uniform interpolation of seismic data is identified as a prolonged challenge in energy exploration. Since geophones cannot be precisely placed at positions corresponding to theoretical grid points, current uniform interpolation techniques frequently suffer deviations and detail distortion. Methods This study proposed a novel non-uniform interpolation method based on a diffusion probabilistic model, which is an emerging generative model in deep learning that involves the diffusion and generation processes. In the diffusion process, noise is added to the complete seismic data iteratively to train the denoising capability of the neural network. In the generation process, the neural network is …

A Petrophysical Modeling-Guided Method For Predicting Parameters Of Low-Permeability Reservoirs, Wang Rui, Li Fang, Liu Shiyou, Sun Wanyuan, Li Songling, Huang Sheng

Coal Geology & Exploration

Backgroud Accurately predicting reservoir parameters is significant for characterizing subsurface reservoirs, establishing gas accumulation patterns, releasing production capacity, and understanding fluid migration. The traditional approaches based on core measurement or mathematical-petrophysical modeling are limited by the strong multiplicity of solutions and low accuracy of elastic parameters inversion results, making it difficult to meet the demands of modern exploration.Objective and Methods To more effectively predict reservoir parameters, this study proposed a petrophysical modeling-guided method for predicting parameters of low-permeability reservoirs. With the convolutional neural network (CNN) as a deep learning framework, the proposed method can predict water saturation, clay content, …

Periodic Roof Deformation And Failure And Associated Water Inflow Characteristics During The Mining Of Typical Coal Seams In The Inner Mongolia-Shaanxi Contiguous Area, Zhou Zhenfang, Dong Shuning, Dong Yang, Luo Shenghu, Xue Jiankun, Wang Zhizhou, Wang Shuxuan, Shang Hongbo, Wang Tiantian, Wang Yutong, Wang Tong

Coal Geology & Exploration

[Objective] The disturbance of coal mine mining damages the aquifer/aquiclude structures of the overburden, causing concentrated water inflow and further affecting safe production in mines. [Methods] Using methods of the physical simulation of similar materials, numerical simulation, and on-site in situ monitoring, this study investigated the water inflow during the mining of the dominant 3-1 coal seam, typically influenced by water in sandstones on the coal seam roof, in the Inner Mongolia-Shaanxi contiguous area. By comparing the measured data of mines with similar geological and mining conditions in the surrounding area, this study delved into the periodic evolutionary patterns of …

Mechanical Characteristics And Fracture Propagation Mechanism Of Deep Coal Reservoirs In The Shenfu Block, Mi Honggang, Wu Jian, Peng Wenchun, Xu Lifu, Li Yong

Coal Geology & Exploration

[Objective] Clarifying the mechanical properties and in-situ stress distributions of coal seams, along with the mechanisms behind their control over the morphologies and propagation behavior of artificially induced fractures, is crucial to the fracturing design, well pattern deployment, and coalbed methane (CBM) production of deep coal seams. [Methods] This study investigated the Nos. 8 and 9 coal seams of the Taiyuan Formation in the Shenfu block in the northern portion of the eastern margin of the Ordos Basin. Using data from sonic logging, density logging, injection/falloff well tests, and production, this study systematically analyzed the mechanical …

Characteristics Of Gas Bursting And Application Of Layered Cutting Drilling In Outburst Coal Seam, Wang Yonglong, Zhao Aoqi, Yu Zaijiang, Wang Zhenfeng, Liu Xiao, Ma Denghui, Zhang Hui, Liu Chun

Coal Geology & Exploration

Objective The overlimit gas bursting in the drilling process of outburst coal seam is a safety hazard that threatens the efficient production of the mine. The layered cutting drilling method helps to weaken the burst gas pressure in the borehole, but the characteristics of gas release around the trapezoidal borehole formed by layered cutting are unknown, which limits the structural design and application effect of the layered cutting drilling tool. Methods Herein, study was conducted based on the layered cutting boreholes with different layer spacing and layer thickness difference. Specifically, a mathematical model was established to analyze the gas flow …

Enrichment Patterns And Exploration Countermeasures Of Deep Coalbed Methane In The Linxing-Shenfu Block On The Eastern Margin Of The Ordos Basin, Xu Changgui, Ji Hongquan, Wang Cunwu, Zhu Xueshen

Coal Geology & Exploration

Objective Some insights have been gained into the enrichment and accumulation patterns of deep coalbed methane (CBM) in high-rank coal seams on the eastern margin of the Ordos Basin, represented by the Daning-Jixian block. However, the exploration of deep CBM in medium-rank coal seams in the Linxing-Shenfu block, located in the northern segment of the basin's eastern margin remains in its initial stage, leading to an inaccurate and unclear understanding of the enrichment and accumulation patterns. This necessitates summarizing these patterns to effectively guide deep CBM exploration and exploitation. Methods Focusing on the Nos.8 and 9 coal seams of the …

Discovery Of A Large Gas Field Of Deep Coalbed Methane In The Shenfu Block And Its Implications, Zhu Guanghui, Ji Hongquan, Mi Honggang, Zhang Yingchun, Sun Qiang, Zhao Wei, Zhu Xueshen, Kang Lifang, Wang Yuchuan

Coal Geology & Exploration

Background After explorations of unconventional natural gas for nearly two decades in the Shenfu block on the eastern margin of the Ordos Basin, deep coalbed methane (CBM) with reserves of 100 billion m³ was discovered in this block in 2023. However, the preliminary exploration of deep CBM in this block faces challenges of insufficient understanding of geological laws, immature fracturing technologies, and a lack of production technologies and experience.Methods and Results Driven by both management and technological innovations, encouraging exploration results have been achieved. The management innovations include: (1) The implementation of a complementary and three-dimensional exploration model …

Predicting The “Sweet Spot” Of Deep Coalbed Methane Based On Resource Conditions And Fracability, Zhao Zhigang, Zhu Xueshen, Wang Cunwu, Zhu Yanhe, Lyu Yumin, Chen Silu, Qi Yu, Tian Yongjing

Coal Geology & Exploration

Objective China has made breakthroughs in the exploration of large-scale deep coalbed methane (CBM) reservoirs along the eastern margin of the Ordos Basin. However, effectively converting the reserves of these reservoirs into production and achieving their efficient exploitation remain unclear. Methods Based on the geological, tests, fracturing, and production performance data, this study conducted research into the assessment of geological-engineering dual “sweet spots” of deep CBM in the southern Shenfu block by focusing on the resource conditions and fracability of deep CBM reservoirs. [Results and Conclusions] Key findings are as follows: (1) The study area hosts suitable coal-forming facies zones …

Processing Of Impulse Noise In Magnetotelluric Data Based On Bidirectional Recurrent Imputation, Yang Kai, Liu Cheng, Li Han, He Jinglong

Coal Geology & Exploration

Objective Magnetotelluric sounding is an exploration method to obtain the underground electrical structure by observing the natural electromagnetic field, which is easily disturbed by noise. Impulse noise, frequently occurring in magnetotelluric sounding, generally exhibits high amplitude and wide frequency bands, producing significant impacts on the data quality. Methods To suppress such noise, this study proposed a method based on a bidirectional recurrent imputation for time series (BRITS) model. First, the data segments with noise interference were deleted. Second, for the magnetotelluric time series with missing data to be imputed, training sets were constructed for imputation training of the BRITS model. …

Structure Optimization Of Foam Generator For Soft Coal Seam And Foaming Effect Simulation, Jin Xin

Coal Geology & Exploration

Objective The application of air screw drilling technology in gas drainage borehole within soft coal seam presents challenges, including severe dust pollution, low drill bit lifespan, and great difficulty in borehole purification. The use of air screw foam drilling technology is an effective way to solve the problem. A foam generator with good foaming performance is one of the keys to implementing the foam drilling technology. However, most current foam generators could not meet the requirements. Methods In response to this issue, a small-sized foam generator was designed based on the spiral foam generator, with an air kinetic energy conversion …

Artificial Intelligence Logging: Fundamental, Principle, Technique, And Application, Cheng Xi, Ren Zhanli

Coal Geology & Exploration

Background Intelligent hydrocarbon exploration and exploitation have become a trend and hot research topic in the oil and gas industry. Artificial intelligence logging (AIL) exhibits considerable potential to address challenges in the explore-exploit of unconventional hydrocarbon resources, as well as resources in complex environments in the deep earth and deep ocean. However, the driving mode, fundamental, implementation principle, structure, and application scenarios of AIL remain understudied. Objective and Methods To build a comprehensive ecology of the AIL system and thoroughly explore and reveal the potential and value of AIL, this study employed methods like literature analysis, theoretical research, technical analysis, …

Seismic Data Denoising Based On The Convolutional Neural Network With An Attention Mechanism In The Curvelet Domain, Bao Qianzong, Zhou Mei, Qiu Yi

Coal Geology & Exploration

[Objective] Noise in seismic data significantly affects the accurate interpretation of subsurface stratigraphic information. Given that effective signals with pronounced lateral correlations in seismic data are distributed in specific coefficients but random noise typically spreads uniformly over all coefficients in the curvelet domain, more effective separation of signals can be achieved. [Methods] The convolutional neural network based on the attention mechanism can adaptively extract key information by focusing on important features of images. Hence, this study proposed a noise attenuation method for seismic data using a convolutional neural network based on the curvelet transform and attention mechanism (Curvelet-AU-Net). First, the …

Characteristics And Transformations Of Mineral Phases In Burnt Rocks, Yalikun Rexiti, Huang Lei, Yang Fan, Xue Xiaoyuan, Song Shijun, Hu Jian, Zhang Zeyu, Ji Zhongkui

Coal Geology & Exploration

Objective Burnt rocks are special rocks formed by the surrounding rocks that are baked due to the spontaneous combustion of coal seams. They are extensively distributed in the Yan’an Formation on the northeastern margin of the Ordos Basin. However, the characteristics and formation mechanisms of burning-associated mineral phases in these rocks remain unclear. Methods This study conducted analytical tests and high-temperature heating simulations of protolith to analyze the mineral phases of underground burnt rocks in the Zhangjiamao Coal Mine, Shaanxi Province. Results and Conclusions The results indicate that the underground burnt rocks exhibit enrichment in mafic components, abnormal migration of …