Earth Sciences Commons^™

Laws Of Changes In The Energy Of Gas Hydrate-Bearing Coals Under Different Confining Pressures And Saturations, Zhu Wei, Gao Xia, Zhang Baoyong, Wu Qiang

Coal Geology & Exploration

Gas hydration for the solidification of coal seams susceptible to outbursts is a novel technology used to prevent coal and gas outbursts by reducing gas pressure and enhancing coal strength. However, an unclear understanding of the failure characteristics and the energy dissipation law of gas hydrate-bearing coals under different confining pressures and saturations leads to the lack of a theoretical basis for the prevention of dynamic disasters such as field coal and gas outbursts in deep mines. Based on the deviatoric stress-strain curves obtained using triaxial compression tests, this study calculated and analyzed the laws of changes in energy of …

Fracture Propagation Mechanism In Directional Perforation And Hydraulic Fracturing Of Coal Seam Horizontal Wells, Pang Tao, Jiang Zaibing, Hui Jiangtao, Jia Bingyi

Coal Geology & Exploration

Horizontal well perforation and fracturing in complex coal-bearing strata are key to increasing coal seam permeability and enhancing gas extraction efficiency, with the formation structure and perforation location determining fracture propagation. Considering the characteristics of formation structure and perforation locations, a fracturing geological model is established. Based on the finite element method, a numerical model is constructed to study the effects of perforation location, formation conditions, and the difference between vertical stress and horizontal stress on fracture perforation. Engineering verification is conducted, and construction suggestions are proposed. Key findings are as follows: There are three scenarios for the perforation locations: …

An Intelligent Water Source Discrimination Method For Water Inrushes From Coal Seam Roofs In The Inner Mongolia-Shaanxi Border Region, Wang Hao, Sun Junqing, Zeng Yifan, Shang Hongbo, Wang Tiantian, Qiao Wei

Coal Geology & Exploration

Water hazard on the coal seam proof induced by high-intensity coal mining are increasingly prominent in the Inner Mongolia-Shaanxi border region. The effective, accurate water-source discrimination of the water inrushes is the key to water hazard prevention. This study investigated three typical mines in the Inner Mongolia-Shaanxi border region. To this end, principal component analysis (PCA) was employed to extract principal components from 80 groups of groundwater samples. Then, with inorganic indicators K⁺+Na⁺, Ca²⁺, Mg²⁺, Cl⁻, SO₄ ²⁻, HCO₃ ⁻ and TDS and organic indicators UV_{254 …}

Sulphate Contamination In An Abandoned Coal Mine In Light Of Mining Effects, Qi Yueming, Zhou Pei, Zhou Lai, Jiang Dan, Yang Yuqing, Liu Yanzhuo

Coal Geology & Exploration

Abandoned high-sulfur coal mines will become deeply buried acid-producing contamination sites, posing hazards to adjacent aquifers and surrounding environments. Furthermore, mining effects and the complex spatial distribution of abandoned mines complicate the assessment of the contamination processes and degrees in adjacent aquifers. Focusing on a certain abandoned coal mine, this study examined the migration characteristics of SO₄ ²⁻ pollution in acid mine drainage using numerical simulations by taking sulfate (SO₄ ²⁻) as the characteristic contaminant and considering the effects of the fractures formed by the mining of multiple coal seams on the aquifer structure. Furthermore, it analyzed …

Three-Dimensional Forward Modeling Using The Transient Electromagnetic Method Under Complex Terrains And The Analysis Of Terrain Effects, Qu Shaobo, Zhu Jiao, Jiang Zhihai, Li Maofei, He Zhilong

Coal Geology & Exploration

The ground-based transient electromagnetic method (TEM), with unique advantages, has been extensively applied for hydrogeological exploration in coal mines. However, in field exploration, complex terrains tend to cause variations in geometric shapes of transmitting sources and deviations in signals received, reducing exploration accuracy. Hence, by integrating theoretical analysis and numerical simulations with the analysis of actual terrain data, this study systematically investigated the response characteristics of electrical- and magnetic-source TEM fields under complex terrains. Using the vector finite-element electromagnetic forward modeling technique based on second-order backward Euler discretization, this study delved into the laws of influence of peak and valley …

Exploring The Detection Performance Of Different Array Configurations For Multi-Electrode Resistivity Method Tomography Using A 2.5d Finite Element Method, Zhao Rongchun, Lyu Yuzeng, Zhang Zhi, Wei Liuye, Pan Hongxu

Coal Geology & Exploration

Multi-electrode resistivity method is equipped with various electrode array configurations. Due to their different electrode arrangements, various electrode array configurations tend to exhibit significantly varying detection effects under different survey environments. Hence, to achieve satisfactory detection effects using high-resolution electrical resistivity tomography, it is necessary to explore the strategy for choosing appropriate array configurations targeting different objects in practical work. Given the high applicability of the method, its forward and inversion calculations remain a critical task. Based on the differential equations to be satisfied by the point source potential in a three-dimensional structure, this study derived the variational problem to …

Research On Path Planning Methods For Underground Roadheader Robots, Zhang Xuhui, Zheng Xili, Yang Wenjuan, Li Yuyang, Ma Bing, Dong Zheng, Chen Xin

Coal Geology & Exploration

In order to solve the problems of difficulty and low efficiency in the movement of robotic roadheaders under conditions of non-full-section roadways in coal mines, the characteristics of unstructured environments in coal mines and the motion characteristics of robotic roadheaders were analyzed, and a path planning method for robotic roadheaders based on deep reinforcement learning was proposed. The tunnel environment was constructed in real time using depth cameras, a virtual model for detecting roadheader-tunnel collisions was established, collision detection was performed in a virtual environment using the hierarchical bounding box method, and an obstacle avoidance strategy under the restrictions of …

Intelligent Identification Method For Overburden Three Zones Of A Goaf, Li Jianwen, Zhao Wen, Wu Zhenkun, Xu Xiaobing, Wang Qingtao, Duan Longchen

Coal Geology & Exploration

In this paper, an intelligent identification method was proposed to ascertain overlying strata failure types and fracture development in the overlying strata of a goaf, and identify three zones (sagging zone, fractured zone and caving zone) quickly and accurately. This method is expected to be a basis in later development of goaf treatment plans. A coal mine goaf in Shandong Province was introduced for case study, where the Bayesian Online Changepoint Detection (BOCD) algorithm was employed to analyze the changes and response characteristics of the drilling fluid loss and drilling rate over the drilling process at the boundaries of three …

Edge Detection Of Low Illumination Image In Cutting Unit Of Shearer, Jia Pengtao, Jin Luwei, Wang Bin, Guo Fengjing, Li Na

Coal Geology & Exploration

In this paper, a fractional differentiation-based edge detection algorithm named Lif is proposed to address the edge detection problems of missing edge and fuzzy details in the cutting unit of shearers working in low-light underground environments. First, the initial fractional mask operator was built using a larger detection template according to the Grünwald-Letnikov definition of the fractional derivative. Then, the weight coefficients at various positions of the mask operator were determined according to the theory of Pascal’s triangle, and the mask operator was extended to four different directions. Finally, the mask operator was convolved with the image, and the local …

Exploring Dynamic Parameters And Tooth Structure Of Self-Propelled Borehole Repairing Drill Bits, Liu Yong, Li Yang, Wei Jianping, Yuan Yongwang, Dai Shuo, Li Linyu

Coal Geology & Exploration

Self-propelled borehole repairing drill bits provide an effective technique for repairing long boreholes that have failed. In order to further improve the borehole repair speed and gas drainage efficiency, based on the theory of jet recoil, the relationship between the jet recoil force and nozzle parameters was analyzed, and a theoretical model was established for rotational mechanics of self-propelled borehole repairing drill bits. Subsequently, the coal-breaking processes of drill bits with different tooth structures were simulated using LS-DYNA, the failure modes in coal mass broken by cutting teeth and the rules of variation in the volume of coal broken by …

An Assessment On The Influence Of Aridity And Vegetation Cover On Land Surface Temperatures: Case Of Dodoma Urban District, Tanzania, Carolyne Vincent Mbirika

Research, Papers & Creative Work

This study examines the influence of aridity and vegetation cover on land surface temperature (LST) in Dodoma Urban District, Tanzania, a semi-arid environment experiencing rapid urban growth. Using Landsat 9 satellite imagery (30 m resolution) for October 2023, key environmental variables including the Normalized Difference Vegetation Index (NDVI), Normalized Difference Moisture Index (NDMI), and LST were derived and analyzed using ArcGIS Pro. The study applies remote sensing techniques and spatial analysis to examine the relationships between vegetation, moisture availability, and surface temperature patterns. The results reveal substantial spatial variation across the study area, with NDVI values ranging from -0.17 to …

Ai’S Carbon Shadow: An Exploration Of The Energy Dilemma And Earth’S Future, Olga Roussos

Student Publications and Presentations

As artificial intelligence continues to advance, more processing power and energy usage are required. This increase in energy consumption by AI leads to increased carbon emissions in the atmosphere as well as rapid resource depletion. The effects of AI’s growing energy consumption can have severe negative impacts on global climate, biodiversity, sustainability, and other aspects of the environment. This research aims to highlight the volume of energy that artificial intelligence uses, the expected environmental effects of artificial intelligence’s expansion, as well as the potential innovative solutions and sustainable practices that can be implemented to decrease energy usage and preserve the …

Arkansas Soil Erosion And Conservation Methods In Ornamental Landscapes, Abby J. Cutsinger

ATU Scholars Symposium

This study will attempt to identify the best soil erosion mitigation methods for Arkansas ornamental landscape settings by comparing the strengths and weaknesses of known techniques. Since soil is not a renewable resource, we must apply conservation practices wherever possible, not just in agricultural settings. To determine the most effective erosion prevention techniques, this study will review soil studies conducted by the NRCS and NASA, as well as articles on best practices observed in ornamental landscape and agricultural industries. These are analyzed by comparing and contrasting techniques against known problems with Arkansas soil to determine which methods are most effective. …

Phighting Phosphorus: The Effects Of Sedimentary Phosphorus On The Macatawa Watershed, Elizabeth Kelley, Rachel Fusik, Jake Lyon

23rd Annual A. Paul and Carol C. Schaap Celebration of Undergraduate Research and Creative Activity (2024)

Lake Macatawa experiences severe eutrophication and algal blooms that negatively impact the native species and recreational usage of the lake. There have been several previously completed studies on phosphorus pollution in the water by the Hope College Day1 Watershed Group. However, these measurements do not include lake sediments, which could also be a significant reservoir of phosphorus. Our research group decided to test the sediment at the same three lake locations tested by the Watershed Group, taking two core samples at each location. These samples were dried, combusted in a muffle oven, weighed, digested from solid to liquid, and then …

Potential Non-Carbonate Buffering In An Interdunal Wetland/Slack Along Lake Michigan, Faith Huff

23rd Annual A. Paul and Carol C. Schaap Celebration of Undergraduate Research and Creative Activity (2024)

Interdunal wetlands/slacks occur in Lake Michigan's coastal dunes where the wind scours the sand to the water table. Since May 2016 we have performed ecohydrological studies on the largest interdunal wetlands/slack, ~1.25 ha in size, lying within a deflated parabolic dune east of Lake Michigan at the Saugatuck Harbor Natural Area, Michigan. The slack’s hydrology is influenced by Lake Michigan-Huron, appearing and increasing in size and water depth with rising lake levels and decreasing in size to drying with low levels. Prior to 2014, the slack was completely dry and dominated by upland dune species due to low lake levels. …

Development Of A Liquid Chromatography Method For The Quantification Of Carbohydrates In Peat Soils, Christopher Klaver, Parker Diaz, Abigail Brewer, Gael Figueroa-Enriquez, Madison Smith

23rd Annual A. Paul and Carol C. Schaap Celebration of Undergraduate Research and Creative Activity (2024)

Peatlands are an important carbon sink. However, climate change threatens to cause the peatlands to release their stored-up carbon. This would result in lots of carbon dioxide and methane to be released into the atmosphere due to the increased peat decomposition. This would end up forming a positive feedback loop, and thus resulting in more and more carbon lost from the peat. The biochemical composition of the peat is an indicator of the degradation state of the peat as well as its ongoing vulnerability to decomposition. In this study, we developed an HPLC method for analyzing the carbohydrate composition of …

No "Butts" About It: The Heavy Metal Impact Of Cigarette Litter, Faith Huff, Connor Monson, Spencer Whittington

23rd Annual A. Paul and Carol C. Schaap Celebration of Undergraduate Research and Creative Activity (2024)

Cigarettes are the most common litter globally. Following smoking, the filter is left with carcinogenic compounds, tar and metals. All of which are highly toxic for wildlife, affecting reproduction, behavior and mortality rate in animals. The heavy metals that are left within the filter also have potential to leach from the cigarettes and enter the groundwater system. As these heavy metals enter the system, it leads to adverse effects on the environment and can cause detrimental health effects in humans, such as cell damage, induced carcinogenic processes and loss of cellular functions. Much research that exists currently only focuses on …

Temperature Sensitivity Of Nitrogen Mineralization In Peat From Bogs Across A Michigan Transect, Madison Smith, Hannah Sturgeon, Abigail Brewer, Gael Figueroa-Enriquez, Christopher Klaver

23rd Annual A. Paul and Carol C. Schaap Celebration of Undergraduate Research and Creative Activity (2024)

In this study, seven peat bogs across a latitudinal transect of Michigan were used to analyze inorganic nitrogen (nitrate and ammonium) release from peat to predict the impact that climate warming has on peatland nitrogen cycle. More nitrogen release is expected in samples kept at warmer temperatures (simulated climate warming) and also from samples from lower latitudes in the transect. 1-m peat core samples were taken at each site. 20 g of acid washed sand was added to upper chambers of microlysimeters (two-chambered filter towers). 50 g of peat was added onto the sand and was left to equilibrate for …

Stream-Borne Floating Mismanaged Waste In Holland, Michigan: Focus On Foam, Sam J. Haakenson, Reina A. Duron

23rd Annual A. Paul and Carol C. Schaap Celebration of Undergraduate Research and Creative Activity (2024)

Streams and storm drain systems link terrestrial roadside litter to rivers and lakes, which eventually supply floating debris to the global ocean. To better understand this linkage, we evaluated the kinds and quantity of floating mismanaged solid waste being transported in five streams within the Lake Macatawa watershed in the environs of Holland, Michigan. We deployed floating litter booms in the four smallest streams. These consisted of a rip-stop nylon sleeve encasing pool noodle floats strung on a wire rope. These were placed diagonally across the stream and anchored to fence posts set into the stream banks. In the largest …

Climatology Of Tornadoes In Kansas, John P. Wasinger, Todd Moore

SACAD: Scholarly Activities

Recent studies report changes to the climatology of tornadoes in the United States (US). Changes with the most supporting evidence include an increase in the intra- and inter-annual variability, increased concentration of tornadoes in bigger outbreaks, and a geographic shift of the densest tornado activity away from Tornado Alley in the Great Plains and toward the Great Lakes and Southeast regions of the US. Broad, national-level changes are valuable, but they can mask changes occurring at the state and sub-state levels where mitigation efforts are most effective. Kansas is of interest due to its reputation as a hotbed of tornado …

Dispersion Of Artificial Tracers In Ventilated Caves, Claudio Pastore, Eric Weber, Frédéric Doumenc, Pierre-Yves Jeannin, Marc Lütscher

International Journal of Speleology

Artificial CO₂ was used as a tracer along ventilated karst conduits to infer airflow and investigate tracer dispersion. In the karst vadose zone, cave ventilation is an efficient mode of transport for heat, gases and aerosols and thus drives the spatial distribution of airborne particles. Modelling this airborne transport requires geometrical and physical parameters of the conduit system, including the cross-sectional areas, the airflow and average air speed, as well as the longitudinal dispersion coefficient which describes the spreading of a solute. Four gauging tests were carried out in one mine (artificial conduit) and two ventilated caves (natural conduits). …

Assessing The Spatial Variability Of Soil Physical Properties Under A Corn Field In Kentucky, Usa, Sai Neela Kesumala

Scholars Week

Analyzing soil physical properties is crucial for advancing sustainable and precision agricultural practices in today's world. Sustainable agriculture emphasizes responsible resource utilization and preservation. Precision agriculture utilizes technology, data, and targeted decision-making to optimize resource usage and minimize environmental impacts. Assessing soil property variability aids in efficient input application, irrigation adjustment, nutrient runoff reduction, and fertilizer management. This approach prioritizes soil conservation, boosts sustainability, and supports long-term agricultural productivity. This study aimed to evaluate the spatial distribution of specific soil physical properties across the four border rows, central corn field area, and sod area. Seventy-two soil samples were collected from …

Applied Depositional Geosystems Of The Coos Bay Basin, Oregon: Organic Geochemistry, Maturation, Paleoenvironmental Reconstruction And Biostratigraphy Of The Coaledo Delta During The Middle Eocene Climatic Optimum (Meco), Allison K. Barbato

LSU Doctoral Dissertations

The Coos Bay Basin on the southwestern coast of Oregon is a forearc basin that contains exceptionally preserved Eocene to Miocene, tidal to wave-dominated, shallow deltaic to deep marine sediments of the Coaledo Delta. Coastal depositional environments are known to host source, reservoir, and seal rocks. Climate, topographic relief, and geographical position all play an important role in regional vegetation development and oceanic setting. This study assesses 84 outcrop and 12 core samples from Coos Bay for their organic geochemical characteristics and microfossil assemblage to provide source rock characterization information, organofacies descriptions, environmental reconstructions, and age control.

Results indicate the …

Quantification Of Belowground Biomass And Sediment Accretion In Mangroves Of Different Coastal Environmental Settings Of The Costa Rican Pacific Coast, Denise M. Poveda

LSU Master's Theses

The adaptation of intertidal ecosystems such as mangroves to anticipated accelerated relative sea level rise is dependent on net increase of sediment surface elevations and forest migration inland. Ecosystem models developed to simulate trajectories of ecosystem adaptations have determined that rates of soil formation are most sensitive to surface sediment (organic and inorganic) deposition and subsurface organic production by mangrove roots. Mangrove belowground biomass contributes to soil organic matter accumulation, while mangrove litter has minor contribution due to export and annual decay. In addition to belowground biomass production, inorganic sediment loading is also key contribution to soil formation and accretion. …

Estimation Of Useful-Stage Energy Returns On Investment For Fossil Fuels And Implications For Renewable Energy Systems, Emmanuel Aramendia, Paul E. Brockway, Peter G. Taylor, Jonathan B. Norman, Matthew Kuperus Heun, Zeke Marshall

University Faculty Publications and Creative Works

The net energy implications of the energy transition have so far been analysed at best at the final energy stage. Here we argue that expanding the analysis to the useful stage is crucial. We estimate fossil fuelsʼ useful-stage energy returns on investment (EROIs) over the period 1971–2020, globally and nationally, and disaggregate EROIs by end use. We find that fossil fuelsʼ useful-stage EROIs (~3.5:1) are considerably lower than at the final stage (~8.5:1), due to low final-to-useful efficiencies. Further, we estimate the final-stage EROI for which electricity-yielding renewable energy would deliver the same net useful energy as fossil fuels (EROI …

Festival Of Research Abstracts, Spring 2024, College Of Science And Mathematics, Wright State University

Festival of Research

The collection of abstracts accepted for the Spring 2024 Festival of Research hosted by the Wright State University College of Science and Mathematics.

Paradox Lost: Wide Gape In The Ordovician Brachiopod Rafinesquina Explains How Unattached Filter-Feeding Strophomenoids Thrived On Muddy Substrates, Benjamin F. Dattilo, Rebecca L. Freeman, Kyle Hartshorn, David Peterman, Aaron Morse, David L. Meyer, Lindsay G. Dougan, James W. Hagadorn

Earth and Environmental Sciences Faculty Publications

Strophomenoid brachiopods had thin, concavo-convex shells, were ubiquitous colonizers of Palaeozoic muddy seafloors, and are hypothesized to have filter-fed in a concave-upward orientation. This orientation would elevate their line of commissure out of potentially lethal lophophore-clogging mud. The paradox is that epi- biont distributions on strophomenoids support a convex-upward life position, as do studies of strophome- noid stability and trace fossils formed by strophomenoid sediment-clearing. A premise of the concave-upward orientation hypothesis is a narrow gape, which causes narrow, high velocity inhalant currents, leaving strophomenoids vul- nerable to sediment entrainment. Herein we investigate the gape angle of Rafinesquina using serial …

Consumer Preferences For Wood-Pellet-Based Green Pricing Programs In The Eastern United States, Sydney Oluoch, Pankaj Lal, Andres Susaeta, Meghann Smith, Bernabas Wolde

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Co-firing wood pellets with coal is an attractive alternative energy generation method with economic, social, and environmental benefits for the US energy generation sector. One way to sustainably use wood pellets for co-firing is to create consumer-supported green pricing programs (GPPs). Our study surveyed residents of five states (Alabama, New Jersey, New York, Pennsylvania, and Virginia) to investigate preferences for the attributes of a hypothetical GPP. The study applied the Best Worst Choice method, which employs the Best Worst Scaling (BWS) and binary choice (BC) task. The BWS analysis showed that residents of all five states most value the flexibility …

Evaluating The Role Of Titanomagnetite In Bubble Nucleation: Rock Magnetic Detection And Characterization Of Nanolites And Ultra-Nanolites In Rhyolite Pumice And Obsidian From Glass Mountain, California, Stefanie Brachfeld, Kelly N. Mccartney, Julia E. Hammer, Thomas Shea, Thomas Giachetti

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

We document the presence, composition, and number density (TND) of titanomagnetite nanolites and ultra-nanolites in aphyric rhyolitic pumice, obsidian, and vesicular obsidian from the 1060 CE Glass Mountain volcanic eruption of Medicine Lake Volcano, California, using magnetic methods. Curie temperatures indicate compositions of Fe2.40Ti0.60O4 to Fe3O4. Rock-magnetic parameters sensitive to domain state, which is dependent on grain volume, indicate a range of particle sizes spanning superparamagnetic (< 50–80 nm) to multidomain (>10 μm) particles. Cylindrical cores drilled from the centers of individual pumice clasts display anisotropy of magnetic susceptibility with prolate fabrics, with the highest degree of anisotropy coinciding with the highest vesicularity. Fabrics …

Evaluating The Role Of Titanomagnetite In Bubble Nucleation: Novel Applications Of Low Temperature Magnetic Analysis And Textural Characterization Of Rhyolite Pumice And Obsidian From Glass Mountain, California, Kelly N. Mccartney, Julia E. Hammer, Thomas Shea, Stefanie Brachfeld, Thomas Giachetti

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Nucleation of H2O vapor bubbles in magma requires surpassing a chemical supersaturation threshold via decompression. The threshold is minimized in the presence of a nucleation substrate (heterogeneous nucleation, < 50 MPa), and maximized when no nucleation substrate is present (homogeneous nucleation, >100 MPa). The existence of explosively erupted aphyric rhyolite magma staged from shallow (< 100 MPa) depths represents an apparent paradox that hints at the presence of a cryptic nucleation substrate. In a pair of studies focusing on Glass Mountain eruptive units from Medicine Lake, California, we characterize titanomagnetite nanolites and ultrananolites in pumice, obsidian, and vesicular obsidian (Brachfeld et al., 2024, https://doi.org/10.1029/2023GC011336), calculate titanomagnetite crystal number densities, and compare titanomagnetite abundance with the physical properties of pumice to evaluate hypotheses on the timing of titanomagnetite crystallization. Titanomagnetite crystals with grain sizes of approximately 3–33 nm are identified in pumice samples from the thermal unblocking of low-temperature thermoremanent magnetization. The titanomagnetite number densities for pumice are 10¹⁸ to 10²⁰ m⁻³, comparable to number densities in pumice and obsidian obtained from room temperature methods (Brachfeld et al., 2024, https://doi.org/10.1029/2023GC011336). This range exceeds reported bubble number densities (BND) within the pumice from the same eruptive units (average BND ∼4 × 10¹⁴ m⁻³). The similar abundances of nm-scale titanomagnetite crystals in …