Earth Sciences Commons^™

Fracturing Evolution Mechanisms Of Eroded Coals Under The Temperature Effect Of The Co2-H2O System, Lin Baiquan, Shi Yu, Liu Ting, Shen Yang, Huang Tao

Coal Geology & Exploration

Background Injecting hot flue gas produced and discharged by gas-fired power plants into deep coal seams where gas is difficult to extract enjoys dual benefits: gas production growth and geologic CO₂ sequestration. However, there is an urgent need to determine the impact of the heat-carrying property of hot flue gas on the stability of coal reservoirs. To address this issue, the key is to clarify the fracturing evolution mechanisms of eroded coals under the temperature effect of the CO₂-H₂O system.Methods Using the independently built platform of CO₂-H₂O-coal interactions that consider …

Impacts Of Co2/Ch4/N2 Adsorption/Desorption On The Macromolecular Structure Of Anthracite: Insights From In Situ Raman Spectroscopy, Wang Tian, Pan Jienan, Li Meng, Wang Kai, Tang Zhuyun, Cheng Nannan, Hou Quanlin

Coal Geology & Exploration

Objective and Methods The adsorption/desorption of coalbed methane (CBM) not only induces the macroscopic deformations of coals but also significantly alters their macromolecular structures, with different gases exhibiting greatly varying mechanisms and influence degrees. Utilizing an independently developed in situ laser Raman spectroscopy system, this study revealed the differential structural responses and mechanisms of anthracite under CO₂, CH₄, and N₂ injection. Results and Conclusion Experimental results indicate that gas injection led to notable blue shifts in the D₄, D, D₃, and G peaks characterizing the microcrystalline structures of coals. In contrast, …

Advances In Research On Geological Evaluation Of Compressed Air Energy Storage In Underground Gas Storage Facilities, Jiang Wen, Huang Leqing, Zhang Songhang, Ma Huiying

Coal Geology & Exploration

Background Against the backdrop of achieving peak carbon dioxide emissions and carbon neutrality globally, renewable energy has developed rapidly and is gradually changing the world's energy mix. However, the intermittent and fluctuating nature of photovoltaic and wind power energy is prone to cause grid frequency fluctuations and reduced power supply reliability. Compressed air energy storage (CAES) technology has emerged as the key to the stable operation of the green power grid thanks to its large capacity and low cost.Methods Based on a systematic review of domestic and international literature in recent years, this study organizes the current theoretical and …

Log-Based Identification Of Sedimentary Facies In Coal Measures In The Southern Wuxiang Block, Shanxi Province, China, Jin Yi, Tian Yunqing, Song Huibo, Hu Bin, Yu Zhenfeng

Coal Geology & Exploration

Objective The Carboniferous and Permian coal-bearing strata in the southern Wuxiang block, Qinshui Basin, Shanxi Province, China contain abundant coalbed methane (CBM) resources. To develop intelligent discrimination technology for CBM exploration in this block, it is necessary to establish lithology discrimination criteria based on log data, reveal the response relationships between logging and sedimentary facies, and determine sedimentary patterns. Methods Using a comprehensive analysis of lithologies, sedimentary facies, and logging facies, this study systematically investigated the distributions of logging and sedimentary facies in the Shanxi and Taiyuan formations—the primary coal-bearing strata in the southern Wuxiang block. By comprehensively analyzing the …

Spatial Distribution Of Coalbed Methane Migration Pathways And Selection Of Optimal Target Areas For Coalbed Methane Extraction For Abandoned Mines, Liu Qinjie, Yang Youxing, Wu Benniu, Duan Minke, Deng Zhuoyue, Guo Chenye, Sun Qiang

Coal Geology & Exploration

Objective and Methods The spatial distribution and long-term evolution of effective migration pathways determine the migration pathways of residual coalbed methane (CBM) in abandoned mines. Furthermore, they provide an important basis for selecting the optimal target areas for CBM extraction drilling in abandoned mines and maximizing extraction efficiency. This study investigated the first mining area at the first horizontal elevation of the Songzao Coal Mine in Chongqing. Using a comprehensive approach that integrated theoretical analysis, numerical simulations, and physical simulation experiments using similar materials, this study systematically examined the distribution patterns of effective CBM migration pathways in abandoned mines under …

Geochemical Characteristics And Genesis Of Element Enrichment Of Niobium-Rich-Rare Earth Metal Layer In Longtan Formation Of Zhina Coalfield, Ding Yunlong, Wang Fangfa, Li Bi, Tang Lifang, Yang Yi, Li Shangyuan, Wang Xiaofang, Zou Yinhong, Wang Yang

Coal Geology & Exploration

Background With the increasing demand for strategic metals and the gradual depletion of traditional metal deposit resources, coal and coal-bearing rock series are considered to be potential sources of rare metals, and coal series associated has become one of the main directions of current mineral exploration. A set of coal measure strata rich in niobium (Nb) and rare earth elements (REE) has been found in Zhina coalfield, western Guizhou and the contents of Nb and REE are as high as 334.89 μg/g and 1014.51 μg/g, respectively. This discovery is of great significance to the theoretical study of coal measure metal …

Macroscopic Failure Characteristics And Seepage Pattern Of Damaged Goaf-Side Coal Pillars Under Confined Water Accumulation, Liu Weitao, Chen Dongqi, Liu Yuben, Du Yanhui, Zhao Jiyuan

Coal Geology & Exploration

Background The method of supporting roadways using small coal pillars has been widely applied in China. As a result, the stability of goaf-side coal pillars affects mining safety. Resulting from multiple disturbance effects, coal pillars tend to contain various types of damage fractures. The confined water environment in goaves with water accumulation might cause the instability failure of damaged goaf-side coal pillars. Methods To investigate the impacts of the damage fracture structure on coal stability, this study introduced the concept of relatively stable initial damage fractures. Based on the theory of damage mechanics, this study constructed hydro-mechanical-damage (HMD) coupling models …

3d Advanced Geological Prediction Based On Reflected Seismic Waves And Its Application Effects, Cai Sheng

Coal Geology & Exploration

Objective For the advance geological prediction of tunnels based on reflected seismic waves, the traditional 2D observation method tends to cause spatial positioning deviations of anomalies. To overcome this limitation, this study developed a 3D seismic wave-based advance geological prediction method according to the actual geometries of tunnels. Methods Using the technical path consisting of theoretical analysis, numerical simulation, and engineering verification, this study solved key technical challenges including 3D wavefield reconstruction, spatial modeling, and migration imaging in the 3D detection system. Based on the principle of geometric seismology, this study demonstrated the enhancement effects of 3D observation on the …

A Time Series Forecasting Model Integrating Spatial Features For Inter-Borehole Resistivity And Its Application, Wang Jianghong, Liu Shuo, Wang Gang, Xue Wuqiang, Li Bofan

Coal Geology & Exploration

Background Mine resistivity prediction serves as a core technique for water hazards monitoring in coal mines. However, due to sparse monitoring points and insufficient spatial resolution, conventional prediction approaches fail to capture dynamic resistivity variations under complex geological conditions.Objective and Methods To address this challenge, this study developed a deep learning-based time series forecasting model integrating spatial features for inter-borehole resistivity. Using a prediction framework constructed based on long short-term memory (LSTM) and critical spatial monitoring points selected through Pearson correlation analysis, this model (also referred to as the LSTM model) enabled high-precision prediction of resistivity in unknown areas. …

Hybrid Differentiator-Based Method For Estimating The Drilling Speed Of A Vehicle-Mounted Drilling Rig During Surface Drilling For Mine Rescue, Wang Yunfei, Zhao Jiyun, Hu Yongjie, Zhang Zongyang, Pan Xiaochen

Coal Geology & Exploration

Background Vehicle-mounted drilling rigs (VMDRs), key devices in surface drilling for mine rescue, directly connect the ground and underground disaster-hit areas through vertical drilling, thereby creating rescue channels for trapped people. In this case, the drilling speed of VMDRs serves as an important indicator for evaluating surface drilling operations. However, directly determining the drilling speed is challenging due to the limitations of position sensors. Methods This study developed an estimation method based on a new hybrid differentiator (NHD), allowing the drilling speed to be calculated using measurable displacement signals. First, a continuous switching function was devised, and its convergence characteristics …

Parameter Characteristics And Rock-Breaking Mechanisms Of Horizontal Drilling Of Underground Collapsed Bodies In Coal Mines, Yao Ningping, Dou Xuqian, Han Zhaoyang, Zhang Guohua, Sun Yuchen, Li Hao, Wang Li

Coal Geology & Exploration

Objective With continuously increasing coal mining depth, the risks of hazards such as roof collapse and personnel entrapment caused by high in situ stress and mining-induced pressure have significantly intensified. Drilling emerges as a key means of rapidly establishing rescue passageways. However, the drilling process tends to face multiple challenges, including complex geological structures, unstable collapsed bodies, and low drilling efficiency. Methods This study aims to reveal the rock-breaking mechanisms during the drilling of collapsed bodies, optimize drilling parameters to ensure reliable borehole formation, and achieve efficient drilling of collapsed bodies. To this end, this study developed a large-scale experimental …

Does Bubble Nucleation Occur Heterogeneously In Magmas Feeding Explosive Rhyolite Eruptions? Insights From The Rock Magnetic Properties Of Pumice, Kelly N. Mccartney, Julia E. Hammer, Thomas Shea, Stefanie Brachfeld, Thomas Giacheetti, Bruce F. Houghton

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Nanometer-scale titanomagnetite crystals have been detected in nominally aphyric rhyolite pumice, but whether they are numerous enough to impact bubble nucleation in explosive silicic volcanism was unresolved. This study examines sub-micron crystals using rock magnetic techniques, Rhyolite-MELTS modeling, and physical characterization. We analyzed pumice from four eruptions spanning wide ranges in intensity, storage depth, and bubble number density (1016 to 1013 m−3 liquid): 1060 CE Glass Mountain, 1912 CE Novarupta, 232 CE Taupo, and 0.45 Ma Pudahuel. Calculations assuming monospecific assemblages of 10 and 1,000 nm cubic particles yield titanomagnetite number densities of 1021 to 1013 m−3 dense rock equivalent, …

New Precipitation Is Scarce In Deep Soils: Findings From 47 Forest Plots Spanning Switzerland, Emily I. Burt, Scott T. Allen, Sabine Braun, Simon Tresch, James W. Kirchner, Gregory R. Goldsmith

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

As precipitation infiltrates into soils, it can recharge them, displace previously stored waters, or bypass already-filled pores. Using 3,697 δ2H and δ18O measurements of water collected nearly monthly over >3 years in 47 forest plots across Switzerland, we present a systematic investigation of the controls on mobile soil water transport. We quantified the lags and damping of water as it percolates downward using young water fraction analysis (Fyw), and the fractions of soil water composed by precipitation that fell within the previous month (new water fractions, Fnew). The Fnew of water sampled in surface soils ranged …

The Future Intensification Of Hydrological Extremes And Whiplashes In The Contiguous United States Increase Community Vulnerability, Surendra Maharjan, Wenzhao Li, John D. Bolten, Hesham El-Askary

Mathematics, Physics, and Computer Science Faculty Articles and Research

Hydroclimatic whiplash rapid shifts between drought and flood poses growing risks to U.S. communities. Here, we assess historical extremes and future projections using a normalized streamflow metric: the annual mean flow’s deviation from the 1981–2020 average, expressed as a fraction of that average. This metric is applied to United States Geological Survey records and Localized Constructed Analogs downscaled projections under Representative Concentration Pathways 4.5 and 8.5. Results reveal sharp regional disparities, with drought deficits exceeding 300% of normal flow during multi-year droughts. By linking hydrologic outcomes with the Federal Emergency Management Agency’s National Risk Index, we find that counties facing …

From Coastal Retreat To Seaward Growth: Emergent Behaviors From Paired Community Beach Nourishment Choices, Jorge Lorenzo-Trueba, Arye Janoff, Oshane Thomas, Di Jin, Porter Hoagland, Andrew Ashton

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Coastal communities often address shoreline erosion through beach nourishment, adding externally sourced sand to widen beaches for recreation and property protection. While nourishment enhances beachfront property values, the need for periodic maintenance creates interdependencies where the actions of neighboring communities affect local shoreline dynamics. Using a coupled model of two neighboring communities, we examine the interplay between community nourishment decisions and the redistribution of nourishment sand. We find that the value a community places on wider beaches not only influences their propensity to nourish, but also their and their neighbors' nourishment efficiency and net benefits. Communities that nourish more frequently …

Ocean And Coastal Acidification Monitoring Priorities For The Northeast Us And Eastern Canada, Christopher Hunt, Austin Pugh, Jake Kritzer, Samantha Siedlecki, Kumiko Azetsu-Scott, Parker Gassett, Diane Lavoie, Adam Pimenta, Amy Trice, Elizabeth Turner

Faculty Publications

The Interagency Working Group on Ocean Acidification Monitoring Prioritization Plan 2024 calls for Coastal Acidification Networks to identify the ocean and coastal acidification (OCA) monitoring needs most important for their regions. The Northeast Coastal Acidification Network (NECAN) organized a webinar series to study regional needs, which culminated with a workshop in November 2023. This workshop led to the identification of six priority new Monitoring Needs in addition to the maintenance of current monitoring efforts:

• Improve spatial and temporal scale of monitoring co-located OCA variables and biological measurements to better resolve variability of acidification dynamics in concert with biological processes …

Performance Mapping And Weighting For The Evapotranspiration Models Of The Openet Ensemble, M. Reitz, J. M. Volk, T. Ott, M. Anderson, G. B. Senay, F. Melton, A. Kilic, R. Allen, Joshua B. Fisher, A. Ruhoff, A. J. Purdy, J. Huntington

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Evapotranspiration (ET) accounts for the majority of water available from precipitation in the terrestrial water cycle, and improvements to the accuracy, resolution, and coverage of ET data can enhance hydrologic models and assessments. The OpenET collaboration of six remotely sensed ET modeling teams has demonstrated that an ensemble approach to ET estimation generally provides improved accuracy relative to individual ensemble members. The performance of individual models has been shown to vary by land cover type and climate zone, but a thorough study of the variables that influence model performance differences has not yet been conducted. In this paper, we model …

Assessing Greenhouse Gas Emissions From Michigan’S Drowned River Mouths Using In Situ And Remote Sensing Methods, Jillian A. Greene

Masters Theses

Freshwater estuaries are natural contributors to the carbon cycle including production and emission of methane (CH4) and carbon dioxide (CO2), potent greenhouse gases (GHGs); however, estimates of their contribution to regional and global GHG emissions is largely unconstrained. Few studies have examined the quantification and drivers of lake CH4 and CO2 production in the Great Lakes region and how it may differ in response to anthropogenic development. In this study, CH4 and CO2 emissions were measured from three drowned river mouth estuaries (DRMs) along the eastern shore of Lake Michigan in 2024. The DRMs exist along a latitudinal gradient ranging …

Efficacy Of Lactobacillus Rhamnosus And Its Metabolites To Mitigate The Risk Of Foodborne Pathogens In Hydroponic Nutrient Solution, Esther Oginni, Robin A. Choudhury, Veerachandra Yemmireddy

School of Earth, Environmental, & Marine Sciences Faculty Publications

Hydroponic nutrient solution (HNS) has been established as an ideal conduit for pathogen contamination and proliferation. This study evaluated the efficacy of lactic acid bacteria and their metabolites in mitigating the risk of foodborne pathogens in HNS when compared to conventional chemical treatments. Hoagland’s HNS were prepared according to the manufacturer’s instructions and inoculated with Salmonella Typhimurium, Escherichia coli 0157:H7, and Listeria innocua at 105 CFU/mL cell concentration. These nutrient solutions were subjected to treatment with various concentrations of Lactobacillus rhamnosus live cells, a cell-free extract (CFE) of L. rhamnosus metabolites, sodium hypochlorite and peroxyacetic acid at 22 ± 1 …

Activation Or Deactivation? Rethinking Ferrate(Vi) Reactivity Within A Broader Modulation Framework, Zepei Tang, Yang Deng

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

No abstract provided.

Groundwater-Dependent Ecosystems In Southeastern Utah: An Integrated Analysis Of Hydrology, Ecology, And Landscape Change, Colten Lay

All Graduate Reports and Creative Projects, Fall 2023 to Present

In Southeastern Utah, springs play a critical role in sustaining groundwater-dependent ecosystems (GDEs) in a semi-arid environment. However, they remain understudied and face growing threats from climate change, land use modifications, and hydrologic alterations. This study addresses knowledge gaps in spring occurrence, hydrologic function, and ecological condition by integrating field surveys, remote sensing, and geospatial analysis across multiple spatial scales. It provides a comprehensive assessment of spring hydrology, water quality, and ecological conditions using field surveys, remote sensing, and GIS analysis to establish a foundational baseline of GDE resources in the region. I applied a multi-scale monitoring approach across the …

Dream Pilot Project: Analysis Of Groundwater Development At Six Villages In Ethiopia, Lindsay K. Gordon

All Graduate Reports and Creative Projects, Fall 2023 to Present

This study presents a hydrogeologic assessment of the Distributed Renewable Energy Agriculture Modalities (DREAM) pilot project, an ongoing groundwater development initiative in rural Ethiopia. This project integrates solar-powered groundwater infrastructure across six villages to improve water access, agricultural productivity, and economic stability.

Fourteen production wells were installed at Murche, four at Dalle, and additional test wells at Murche, Dalle, Chefe Kora, and Huluku. Transmissivity values and the number of wells at Murche suggest that local water needs are currently being met. In contrast, fewer wells were drilled at Dalle. This reflects the high cost of well construction relative to yield, …

Tree Rings And The Broader Ocean-Atmospheric Circulation In The Highland Himalayas, Sanjaya Bhandari

All-Inclusive List of Electronic Theses and Dissertations

Climate change has altered tree-growth patterns and resulted in higher sea-surface temperatures across the planet. The Himalayan biome is one of the most vulnerable areas in the world to climate change because it has caused changes in forests’ growth and glaciers’ retreat. Dendrochronology has been used to understand the impact of climate change on tree growth and for climate reconstruction. In this dissertation, I discuss the growth of trees in the highlands of the eastern, central, and western Himalayas for the last 500 years and relate these patterns to the present global warming scenario and broad-scale climate modes. I reconstructed …

Multiscale Drivers Of Water Level Fluctuations And Nutrient Availability In Small Intermittent Reservoirs In The Us Midwest, Uchechukwu Vitus Chinatu Ogbenna

School of Natural Resources: Dissertations, Theses, and Student Research

Reservoir dynamics are often captured by fluctuations in water surface elevation, which reflect a complex interplay of hydrologic inputs, climatic conditions, land use influences, and management operations. While water level fluctuations (WLFs) in large regulated systems have been widely studied, the drivers and implications of WLFs in small reservoirs, particularly those fed by intermittent streams, remain poorly understood. Here, we examined the temporal dynamics of WLFs and their relationship with nutrient availability in nine small reservoirs in the U.S. Midwest using daily records from 1985 to 2022. We used water level classification from modified Zscore and transition matrices to assess …

Insights From Swot Data On Transboundary Upstream-Downstream Impacts In The Nile Basin, Hesham Morgan, Wenzhao Li, Ali Elgendy, Surendra Maharjan, Rejoice Thomas, Hesham El-Askary

Mathematics, Physics, and Computer Science Faculty Articles and Research

This study utilizes high-resolution data from NASA's Surface Water and Ocean Topography (SWOT) mission to investigate water dynamics and upstream-downstream impacts across key reservoirs in the Nile Basin. Focusing on the Grand Ethiopian Renaissance Dam (GERD), Rosaries Dam, Merowe Dam, and the Aswan High Dam, the analysis spans 15 months (August 2023 to October 2024). By systematically selecting 30 points across each reservoir, monthly boxplots of surface water elevation were generated, revealing significant temporal and spatial variability. The results show that GERD’s filling phase led to a steady increase in water levels (peaking at ~615 meters from June to October …

Heat Storage Using High Temperature Borehole Heat Exchangers, Jack Horvath

All Theses

The use of renewable energy sources such as wind and solar power is growing, and with it comes an increased need to store excess energy when it is generated and release it on demand. Moderate temperature thermal energy storage in the subsurface is widely used to heat buildings, but high temperatures, greater than 120℃, are required to power generators that convert stored heat to electricity. High temperature heat can be generated from solar collectors or other means and then transferred to the subsurface using borehole heat exchangers (BHE). A BHE consists of a closed-loop pipe system used to circulate a …

Development And Evaluation Of Supported Ionic Liquid Membrane And Porphyrin Frameworks For Carbon Capture Separation, Sarang Ismail

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

The global urgency to mitigate anthropogenic CO₂ emissions has intensified the pursuit of energy-efficient separation technologies. Supported Ionic Liquid Membranes (SILMs) have emerged as promising candidates for CO₂ capture due to their tunable solubility-selectivity and low energy requirements. However, challenges such as mechanical instability, limited scalability, and trade-offs in transport performance have impeded their widespread adoption.

This thesis explores a systematic approach to designing and optimizing SILMs for enhanced CO₂ separation by tailoring polymer–ionic liquid interactions, processing conditions, and material architectures. A comprehensive set of studies were conducted using poly(vinylidene fluoride) (PVDF) with varying molecular weights, different grades of PEBAX®, …

Ocean-Ice Sheet Interactions During Super-Interglacial Mis 31: Comparison Of Rock Magnetic Records From The Scotia Sea (59.1°S) And Fram Strait (76.5°N), Olga Libman-Roshal

Theses, Dissertations and Culminating Projects

The mid-Pleistocene transition (MPT) was a period spanning ~1.2-0.7 Ma when glacial-interglacial cyclicity changed from 41 kyr obliquity paced to 100 kyr eccentricity paced cycles with increased glacial-interglacial contrast post-MPT. Marine Isotope Stage (MIS) 31 was a “super-interglacial” within the MPT and occurred in the recent geological past (1.08-1.06 Ma). During MIS 31, the tectonic configuration resembled the present day, but Earth’s orbital parameters were marked by maximum values of eccentricity and obliquity while atmospheric CO2 remained at pre-industrial levels (below 280 ppm). MIS 31 therefore offers a valuable baseline for testing the impacts of modern anthropogenic CO2 levels combined …

Decoding Teleconnection Impacts On Hydrological Switches In The Conus Using Wavelet Analysis, Surendra Maharjan, Wenzhao Li, Shahryar Fazli, Hesham Morgan, Hesham El-Askary

Mathematics, Physics, and Computer Science Faculty Articles and Research

Hydrometeorological teleconnections are key drivers of hydrological processes, representing the influence of large-scale atmospheric circulation patterns on regional climates. Understanding these teleconnections provides crucial insights into the mechanisms underlying hydrometeorological phenomena, particularly hydrological switches—rapid transitions between extreme events such as droughts and floods. These switches have become increasingly prevalent across the contiguous United States (CONUS), fueled by climate variability and evolving atmospheric patterns. This study utilizes cross-wavelet transform analysis to examine the spatial and temporal dynamics of hydrological switches and their correlations with major teleconnection indices, including NAO, ONI, WP, PDO, PNA, and QBO. The findings indicate significant coherence between …

Assessing Meteorological Impacts On Hydrological Switches In The Conus, Surendra Maharjan, Wenzhao Li, Sujan Shrestha, Hesham El-Askary

Mathematics, Physics, and Computer Science Faculty Articles and Research

Hydrological switches, defined as rapid transitions between extreme meteorological events such as droughts and floods, are becoming increasingly frequent across the contiguous United States (CONUS) due to climate variability. This study analyzes the spatial and temporal patterns of these hydrological switches and their correlation with large-scale meteorological indices, such as the Standardized Precipitation Index (SPI) and Standardized Precipitation Evapotranspiration Index (SPEI). Streamflow data from the US Geological Survey (USGS) is analyzed to investigate the impact of meteorological drivers on hydrological variability. Results indicate that regions dependent on snowmelt exhibit delayed hydrological responses to climatic conditions, while areas in the Eastern …