Digital Commons Network^™

Ecological Feedbacks In The Earth System, Eugene J. Murphy, Jessica J. Williams, Isla H. Myers-Smith, Vivienne P. Groner, David M. P. Jacoby, Lester Kwiatkowski, Jess Melbourne-Thomas, Emma Ransome, Cristina Banks-Leite, Laurent Bopp, Marion Gehlen, Eileen E. Hofmann, Babette Hoogakker, Nadine M. Johnston, Yadvinder Malhi, Emma L. Cavan

CCPO Publications

Ecological feedbacks are fundamental features of the Earth system, affecting physical processes and chemical cycles. Our understanding of the interactions underlying these feedbacks at different spatial and temporal scales and the extent to which feedbacks affect Earth system functioning remains limited. Climate change and other anthropogenic pressures are already negatively affecting ecological processes in marine, freshwater, and terrestrial ecosystems. These will most likely be amplified in the coming decades under our current warming and socioeconomic pathways. The knock-on impacts on ecological feedbacks have the potential to cause rapid perturbations to the Earth system, and may significantly impact the structure and …

Basal Melting Variability Of The Ross Ice Shelf From Mixing Ratios Of Simulated Water Masses (1993-2018) And Potential Climatic Drivers, Enrico Pochini, Andrea Bergamasco, Florence Colleoni, Manuel Bensi, Giorgio Budillon, Pasquale Castagno, Michael S. Dinniman, Pierpaolo Falco, Emanuele Forte, Vedrana Kovačević, Stefanie L. Mack

CCPO Publications

Several water masses circulate under the Ross Ice Shelf (RIS), the largest ice shelf in Antarctica, each causing basal melting with a specific spatio-temporal pattern. To investigate these patterns and their variability, we applied a mixing ratio analysis to simulated water masses from a new numerical ocean model of the Ross Sea. The simulation, which was run over 26 years (1993–2018) and which includes the RIS cavity, shows good agreement with seaborne and mooring observations. The total RIS basal melt rate is 90 Gt/yr on average, and is caused mostly by High Salinity Shelf Water (HSSW) (68%), which enters the …

Evaluation Of A Novel Re-Crosslinkable Preformed Particle Gel For Conformance Control In Ultra-High Temperature Reservoirs, Yanbo Liu, Tao Song, Caleb Kwasi Darko, Thomas P. Schuman, Mingzhen Wei, Baojun Bai

Chemistry Faculty Research & Creative Works

Preferential fluid flow remains a major challenge in subsurface energy production and gas storage operations, resulting in excessive water production in mature oil fields, reduced heat extraction in geothermal reservoirs, and low sweep and storage efficiency in CO₂-EOR projects. Polymer gels are widely used to mitigate high-permeability channels; however, conventional systems exhibit limited plugging efficiency and short lifetimes in ultra-high-temperature reservoirs due to poor thermal stability. This study presents a novel ultra-high-temperature-resistant preformed particle gel (UHT-PPG) developed for conformance control in reservoirs with temperatures of 150–275 °C and severe super-K or channeling problems. The material was evaluated in …

Nonstationary Spatial Correlation Of Earthquake Ground Motions In California, Pengfei Wang, Busra Bocekli, Junhui Yang, Scott J. Brandenberg, Jonathan P. Stewart

Civil & Environmental Engineering Faculty Publications

Assessing seismic risk to spatially distributed infrastructure systems requires realistic representations of spatially correlated ground motions. Existing models for the spatial correlations of ground motions rely on strong second-order stationarity assumptions, under which the correlation structure is assumed to be invariant across space, potentially masking regional variations. Because repeatable site and path effects can vary spatially, the resulting correlation structure is likely to be nonstationary. We propose a nonstationary spatial correlation method that captures geographically varying correlation decay behavior. We compute site-to-site Pearson correlations of within-event residuals using earthquakes recorded at both sites in each site pair and model the …

Multi-Isotope Tracing Reveals Nitrate And Sulfate Sources And Fate Across Contrasting Activity Zones In A Semi-Arid Basin Of Northern China, Chang Yue, Ruizhong Gao, Limin Duan, Tianke Su, Xixi Wang, Tingxi Liu, Guoqiang Wang

Civil & Environmental Engineering Faculty Publications

In semi-arid surface water-groundwater systems, nitrate (NO₃^–) and sulfate (SO₄²^–) are jointly influenced by natural processes and anthropogenic activities, yet how their sources, transformations, and export vary across contrasting activity zones remains insufficiently understood. Integrating hydrochemistry, multiple stable isotopes, a Bayesian isotope mixing model, and representative-section flux analysis, this study investigated the source compositions, transformation processes, and export differences of NO₃^– and SO₄²^– in the Dahei River Basin.   New hydrological insights for the region: Results showed greater SO₄²^– enrichment in high-activity zones, whereas NO₃^– exceedance was more prominent in low-activity zones. In …

A Tale Of Two Microbialities: Stromatolites And Microbially Induced Sedimentary Structures, Nora Noffke, Stanley M. Awramik

OES Faculty Publications

Microbialites are biosedimentary structures built by microbial mats. Five microbialite groups are distinguished: stromatolites, thrombolites, dendrolites, leiloites and microbially induced sedimentary structures (MISS). This contribution discusses the two most abundant microbialite groups in marine settings, stromatolites and MISS. Microbial interactions with clastic sediment are very similar in both stromatolite and MISS formation. However, in stromatolites, syngenetic carbonate production caused by photoautotrophic and heterotrophic metabolisms and by calcimicrobes also takes place. More so, carbonate may precipitate within the extracellular polymeric substances. Due to the various carbonate forming processes as well as recrystallisation, the microscopic mat fabrics within stromatolite laminae are rarely …

Recirculated Submarine Groundwater Discharge Dominates Nutrient Inputs And Enhances Eutrophication Risk In A Coastal Lagoon, Júlia Rodriguez-Puig, Clara Ruiz-González, Marc Diego-Feliu, Irene Alorda-Montiel, Aaron Alorda-Kleinglass, Daniel Romano-Gude, Andrea G. Bravo, Júlia Dordal-Soriano, Javier Gilabert, Sophia Bergeler, Celine Lavergne, Gemma Casas, Marisol Manzano, Jordi Garcia-Orellana, Valentí Rodellas

OES Faculty Publications

Submarine groundwater discharge (SGD) is a widely recognized pathway for nutrient transport to coastal systems. Prior studies overlook the unique biogeochemical signatures of different SGD pathways, neglecting their differences in biogeochemical transformations and spatiotemporal factors. Here, we present an integrated assessment of nutrient delivery through three SGD pathways (fresh SGD, long‐scale recirculated SGD, and short‐scale porewater exchange), alongside surface water inputs, to evaluate their seasonality and impact on nutrient dynamics in a coastal lagoon. We conducted five field surveys in March, July, and November 2021, July 2024, and March 2025 in the Mar Menor lagoon, an ecosystem facing severe ecological …

Workshop Outcomes Report: 2nd International Workshop On Seismic Resilience Of Arctic Infrastructure And Social Systems, Majid Ghayoomi, Daniela Morganti

Faculty Publications

The report provides an overview of the second international workshop on Seismic Resilience of Arctic Infrastructure and Social Systems. The report discusses agenda, workshop activities, interdisciplinary working groups, and results. It ends with several strategic questions and investigation plans that were developed as part of the workshop activities.

Cervical Ligament Systems In Sauropod Dinosaurs: What Support Is There?, Audrey Rose Williams

Masters Theses

"Sauropod dinosaurs, such as Diplodocus, have been the subject of numerous hypotheses about what ligamentous structures could have lifted and supported their long necks. Because the supportive tissues rarely fossilize, palaeontologists rely on osteological correlates on the bone to infer their nature. Options for supportive cervical ligaments in sauropods are mammal-style nuchal ligaments, avian-style interlaminar elastic ligaments, reptilian-style supraspinal ligaments, or some combination thereof. This study tested for the presence of a mammal-style nuchal ligament via histological and micro-computed tomography of posterior cervical hemispinous processes of Apatosaurus and Diplodocus, in addition to examining gross morphological features of the cervical vertebrae …

Re-Crosslinkable Hyper-Branched Polymer Gels Based On A Transamidation Reaction, Tao Song, Baojun Bai, Thomas P. Schuman

Patents

The present invention generally relates to the field of conformance control in oil fields, particularly to a re-crosslinkable preformed particle gel system, and composition thereof. The composition of the re-crosslinkable preformed particle gel system contains monomers, crosslinkers, a polymer matrix, and additives. Components in the composition for re-crosslinkable preformed particle gel in the present invention have excellent compatibility with each other, and the obtained gel has excellent long term high-temperature resistance property. Different from prior products, in the recrosslinkable preformed particle gel compositions according to embodiments of the present invention, the components that are used to re-crosslink the particle gels …

Modeling The Effects Of Subsurface Tile Drainage On Atrazine And Nitrate Transport In Till Soils Of Iowa, Madison Hobbs

West Chester University Graduate Theses, Dissertations, and Final Projects

Tile drainage design influences groundwater flow pathways, residence time, and agrochemical transport in agricultural soils. This study evaluates how differences in drainage design affect subsurface flow behavior and contaminant transport in glacial till soils. A groundwater model was developed to compare conventional and controlled drainage systems with a shallow drainage system, and particle tracking was used to examine flow paths and residence times.

The results show that tile drainage creates distinct shallow and deeper flow pathways. In the conventional and controlled model, 88% of particles were captured by drains, while 12% reached the general head boundary. The shallow system drains …

Evolution Of A Managed Flood-Tide Delta And Barrier-Beach System, Charlestown, Rhode Island, Zachary Justin Levitan

Open Access Master's Theses

Barrier-beach and estuarine areas are important ecologically and economically, and the inlets connecting them are critical for ocean exchange and greatly dynamic. Man-made jetties are often installed to maintain the connection between ocean and estuary for navigation and water quality benefits. With storms and sea-level rise, coastal systems are changing over days to decades, affecting communities in New England and around the globe. This study utilized remotely sensed data (i.e., aerial imagery, lidar, and sonar) to examine the dynamics of the Charlestown Breachway and its flood-tide delta in southern Rhode Island, USA over varying times scales. The specific research objectives …

Changepoint Analyses Confirms Global Tropical Cyclone Frequency Decline, Michael Wehner, Thomas Fisher, Norou Diawara, Robert Lund

Mathematics & Statistics Faculty Publications

Changes in tropical cyclone frequencies as the climate warms is a topic of significant current debate [1, 2]. There is no accepted theory of how tropical cyclogenesis might respond to a warmer ocean-atmosphere system as multiple controlling factors exist [3–7]. Anthropogenic warming of surface ocean temperatures due to increased greenhouse gas concentrations [8] increases the potential for tropical cyclogenesis [9–11]; however, realized cyclogenesis also requires an initial local disturbance [12–16] to develop. Most multi-decadal tropical cyclone permitting climate models (i.e. resolutions of 15-50km) exhibit frequency decreases in warmer climates, despite the increase in tropical cyclogenesis potential [17–25]. In this paper, …

Urban Trees In The Urban Hydrology Cycle, Jorge R. Vera

Theses, Dissertations and Capstones

In urban forestry, trees provide numerous economic, ecological, and aesthetic benefits to the surrounding community. One of their key roles is intercepting stormwater runoff, reducing flooding risk, and improving water quality. Chapter 1 of this thesis characterized the ecological and economic contributions of urban trees on the Marshall University campus and provides guidance on their management and conservation in the future. Chapter 2 examined how urban tree species modify the urban hydrology cycle by altering the volume and timing of precipitation delivery. In Chapter 1, we inventoried 114 acres of Marshall University's main campus in Huntington, WV, from June 28 …

Solubility And Dissolution Mechanism Of Novel Multi-Ester Headgroup Surfactants In Supercritical Co2, Ning Xu, Yan Ling Wang, Baojun Bai, Shi Zhang Cui, Yu Zhang, Wen Jing Shi, Zhao Nian Zhang, Wen Hui Ding, Pei Xu Ma, Zan Gao

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

To address the limited solubility and applicability of conventional hydrocarbon surfactants in supercritical CO₂, a series of multi-ester headgroup surfactants were designed and synthesized by leveraging the CO₂-philic properties of ester groups. The molecular structures were characterized using Fourier transform infrared (FT-IR) spectroscopy and ¹H NMR. A custom-designed laser-based apparatus was developed to quantify surfactant solubility and systematically investigate phase behavior in CO2. Molecular dynamics (MD) simulations were employed to elucidate structure–solubility relationships across multiple scales, including solubility parameters, interaction energies, radial distribution functions (RDFs), and free volume fractions. Results indicate that, at 323.15 K, …

Early Successional Response To Stream Daylighting In Redwood National And State Parks, Orick, California, Rylee Rawson

Cal Poly Humboldt theses and projects

In-channel stream restoration projects can act as both disturbance and recovery mechanisms, disrupting existing conditions to reestablish the hydrologic and ecological processes that sustain stream ecosystems. These interventions initiate successional trajectories in which channel form and biological communities reorganize over time. In Redwood National and State Parks (California, USA), the Redwoods Rising initiative restores buried headwater channels by recontouring legacy logging roads and daylighting streams buried by Humboldt crossings. Using the National Park Service Klamath Network wadable stream monitoring protocol, I evaluated nine restored reaches spanning one to five years post-restoration, alongside old-growth reference reaches and available pre-treatment data. I …

Application Of Organic Geochemistry To The Characterization Of Hydrochar And Biochar: Insights Into Composition And Optimization, Michael A. Kruge, Teresa A. Centeno, Alvaro Amado-Fierro, José Manuel González-Lafuente, Rubén Forján, José Luis Gallego

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Hydrothermal carbonization has garnered significant attention in recent studies due to potential applications of the hydrochar produced, which overlap with those of torrefied biochar, including soil improvement, carbon sequestration, and energy production. However, unlike the relatively uniform properties of biochar, hydrochar characteristics can vary greatly depending on the feedstock used. Advanced characterization techniques are essential to better understand these materials and enhance their practical applications. Research on hydrochar requires a multi-faceted approach, including molecular-level studies, to optimize production processes and identify specific applications.

In this regard, analytical methods commonly used in organic geochemistry could play a crucial role in deepening …

Temporal Patterns Of Storm Surges: Event-Identification, Clustering, And Count Modeling, Ariadna Martin Oliva

Graduate Studies Theses and Dissertations 2026

Coastal regions face compounding risks when extreme events strike in rapid succession, yet most statistical frameworks treat such events as independent, a simplification that can critically underestimate hazard. This thesis addresses that gap through three interconnected contributions focused on the temporal clustering of storm surges at the global scale. A new automated method is developed to extract independent storm surge events from continuous tide gauge records. By leveraging event correlations and a soft-margin approach that accounts for local variability, the method identifies characteristic event durations across 1,485 global tide gauge stations, revealing the influence of both local site conditions and …

Innovative Methods In Intact Rock Deformation Detection, Ali Abdullah M Alzahrani

Doctoral Dissertations

"An accurate assessment of intact rock deformation is imperative in engineering activities carried out either in or above rock masses. However, instruments used for post-peak deformation are easily debonded and cannot record the whole process of post-peak deformation required in the failure modeling of rocks. This dissertation focuses on the investigation of the performance of two non-contact measuring systems (Laser Displacement Sensor (LDS) and Inductive Proximity Sensor (IPS)) compared to the contact type instrument (conventional Strain Gauge System (SGS)) in monitoring intact rock deformations. Subsequently, an IPS was installed in a high-pressure triaxial testing system before investigating its performance in …

Computational Regolith Mechanics And Instrumentation Development For Lunar Exploration And Resource Utilization, Jared M. Long-Fox

Graduate Studies Theses and Dissertations 2026

Sustained exploration of the Moon requires quantitative understanding of lunar regolith properties to support scientific investigation, in situ resource utilization, excavation, and infrastructure development. This dissertation examines the mechanical interaction between robotic excavation systems and lunar regolith, emphasizing how regolith behavior both enables and constrains exploration-focused and exploration-enabled science. Computational excavation models were compared to laboratory data to evaluate prediction of excavation forces and to develop metrics of excavation efficiency. Laboratory experiments using high-fidelity lunar regolith simulants were conducted to characterize pressure-sinkage behavior, shear strength, and angle of repose across a range of material states. Common analytical excavation and terramechanics …

Milankovitch Paleoclimatic Signals In Upper Permian–Lower Triassic Fluvial-Lacustrine Records, Bogda Mountains, Greater Turpan-Junggar Intracontinental Rift Basin, Nw China, Wentao Zhang

Doctoral Dissertations

"The objective of this study is to understand whether Milankovitch climatic and/or tectonic processes influenced the sedimentation of the upper Permian–Lower Triassic fluvial-lacustrine cyclic deposits in Bogda Mountains, greater Turpan-Junggar intracontinental rift basin, Xinjiang Uygur Autonomous Region, NW China. This study carried out gamma analysis, gamma and astronomical tuning, and spectral analysis on the Wutonggou, Jiucaiyuan, and Shaofanggou low-order cycles of the South and Central Taodonggou, South and North Tarlong, Dalongkou, and Zhaobishan sections. Stable and positive gamma values support the assumption of facies-dependent sedimentation rates for non-marine facies. The sedimentation rates range from 0.04 to 2.43 m/kyr, and 0.21 …

Assessing Dissolved Organic Matter Sources And Dynamics In Urban Stormwater: Implications For Greenhouse Gases, Harper W. Schmalz

Theses and Dissertations (Comprehensive)

Stormwater management ponds (SWMPs) are important aspects of land-use planning and increasingly recognized as active sites of biogeochemical processing that influence carbon cycling; however, little research has investigated the controls on dissolved organic and dissolved inorganic carbon (DOC and DIC) within these systems. This thesis examined the processing and transformations of dissolved carbon between three compartments to support the development of a greenhouse gas (GHG) box-model for urban stormwater ponds, including SWMP sediment, surface water, and vegetation. The objective of this thesis was to assess the biogeochemical processes that govern the rate and transformation of DOC and DIC between these …

Applied Machine Learning In Mineral Prospectivity Mapping In The South Pass-Granite Mountains Of Wyoming, Carl D. York

Graduate Theses/Dissertations

The South Pass-Granite Mountains, comprised of Archean to Tertiary rocks embedded with an Archean greenstone belt in Central Wyoming, have historically been mined for gold, iron, steel, and silver. Rare earth elements have been of increasing interest in the region and thus, several datasets have become available. Knowledge driven and data driven models are used in mineral prospectivity mapping with input data including geological mapping, geochemical data, geophysical (USGS Critical Mineral magnetic and gravity data), radiometric (U, Th, K) data and multispectral remote sensing data. Mineral prospectivity has seen a rapid improvement in recent years using advancements in machine learning …

Flow Regime Shifts And Channel Morphological Adjustments In Response To Changing Climate Patterns: Examples From Gasconade River, Missouri, Usa, Katherine E. Brand

Graduate Theses/Dissertations

Recent changes in climate patterns due to anthropogenic inputs (i.e. greenhouse gases/CO₂) have caused alterations to precipitation events leading to altered flow regimes. Changes in the magnitude and frequency of flood events results in physical adjustments to river morphology, including changes in width and depth. As rivers experience more frequent and larger flood events, they accommodate by changing their morphological characteristics. The Gasconade River, a tributary of the Missouri River located in southcentral Missouri, USA, has exhibited recent patterns of acute bank erosion with limited understanding of its causes and effects on the river. This study aims to understand how …

Short-Term Response Mechanisms Of Water Quantity And Quality Of Daihai Lake Under Temperature-Driven Changes, Hao Zhang, Xiaohong Shi, Xianhua Li, Junping Lu, Ruizhong Gao, Xixi Wang, Shuhao Zhang, Longmei Xie, Yu Liu

Civil & Environmental Engineering Faculty Publications

Temperature-driven mechanisms involving complex feedback and lag that affect the evolution of hydrological processes and ecological functions in cold- and arid-region lakes represent a core scientific issue in current hydrology and lake ecology research. In this study, based on month-scale temperature and environmental factor data from Daihai Lake in Inner Mongolia from January to December 2023, statistical methods (redundancy analysis, Tukey's test analysis, correlation analysis, structural equation modeling), time series analysis methods (dynamic time warping), and machine learning methods (random forest) were combined. A hierarchical and phased response framework was constructed that encompassed driver identification, path tracing, lag characterization, and …

Experiences Of Bukidnon Farmers On The Use Of Carbonized Rice Hulls (Crh) Waste From Biomass Boilers As A Soil Conditioner, Dash Constantine S. Chamen, Queen Loraine D. Ban, Michael Justin O. Eluna, Pole Honson B. Gabitano, Ian Jay P. Saldo, Jhovel Roy D. Calo

Sinaya: A Philippine Journal for Senior High School Teachers and Students

The long-term use of agricultural products that adversely affect soil is a significant issue for farmers. This study explored the potential of carbonized rice hulls (CRH) waste from biomass boilers as a sustainable soil conditioner. The research investigated the specific soil conditioning properties of CRH and explored the lived experiences of nine (9) Bukidnon farmers to correlate their observations with the material’s chemical profile. The composition analysis identified a high silica content and essential micronutrients, such as calcium and magnesium, which act as nutrient restorers and pH regulators. The thematic analysis of semi-structured interviews, four themes emerged to summarize the …

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.

A Method For Advance Detection Of Underground Concealed Water Hazards In Coal Mines Based On Borehole Transient Electromagnetic Method And Vector Synthesis, Fan Tao, Hao Yue, Li Ping, Zhao Rui, Liu Zaibin, Ma Liang, Li Peng, Yan Junsheng

Coal Geology & Exploration

Background The advance detection of underground concealed water hazards in coal mines is crucial to ensuring the safe and efficient roadway tunneling. The borehole transient electromagnetic (TEM) method allows for long-distance advance detection. However, due to the limitation of the spatial structure of boreholes, currently available techniques can only effectively identify low-resistivity anomalies (e.g., water-bearing structures) in the radial direction, leaving blind areas in the primary tunneling direction (i.e., the axial direction of boreholes). Objective and Method To address this challenge, this study proposed a method for the advance detection of concealed water hazards in the axial direction of boreholes …

Fructure Mechanisms And Fracture Distribution Patterns Of Main Roofs In Goaves Within Abandoned Mines, Tao Xuefeng, Shi Biming, Hua Xinzhu, Lin Baiquan, Yue Jiwei, Liang Yuehui, Zhang Chengcheng, Qin Hao, Yang Yong, Xue Yonglin

Coal Geology & Exploration

Objective In abandoned mines, the storage zones of free gas are closely associated with overburden fractures in goaves. To accurately estimate free gas resources in abandoned mines, it is necessary to thoroughly investigate the rupture mechanisms of blocks in main roofs in goaves, as well as the overburden fractures and rupture trace morphologies in goaves. Methods Based on the masonry beam theory, this study established a mechanical model for the primary cantilever beam of a main roof. The analytical solutions of the stress components in the primary cantilever beam were analyzed using the stress inverse method, and the mathematical expression …

Macro-Mesoscopic Developmental Patterns Of Cracks In Surrounding Rocks Of Rectangular Roadways Under True Triaxial Stresses, Shi Wenbao, Xu Qingzhao, Chang Jucai, Li Chuanming, Qiao Longquan, Miao Zhuang, Yan Aoyun

Coal Geology & Exploration

Objective and Method This study aims to investigate the relationship between the stress environment and the deformation and failure responses of surrounding rocks, thereby unraveling the inherent mechanisms underlying the deformation and failure. With cement, river sands, and gypsum as raw materials, rectangular roadway model specimens measuring 200 mm × 200 mm × 200 mm were prepared. Using a large-scale true triaxial seepage coupling testing machine, this study conducted triaxial loading tests on the rectangular roadway specimens under different lateral pressure coefficients. Using microcameras and an acoustic emission system, it monitored the whole process of the macroscopic deformation and failure, …