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Impacts Of Multiple Coastal Stressors Across Life-History Stages In The Eastern Oyster, Amaelia Zyck Jan 2025

Impacts Of Multiple Coastal Stressors Across Life-History Stages In The Eastern Oyster, Amaelia Zyck

Open Access Dissertations

Urbanized estuaries are characterized as a complex of biotic and abiotic stressors, which currently challenge marine life and are expected to intensify and become increasingly unpredictable under the ongoing impacts of climate change. The persistence of coastal species that inhabit these stressful environments will ultimately depend on their ability to adapt. Many of these species have complex life cycles, featuring distinct morphological and physiological developmental stages that can exhibit unique responses to environmental pressures. However, since all stages share the same genome, selective pressures acting on one stage can have cascading effects throughout the life cycle. The larval stage, being …


Novel Methodology And Proof-Of-Concept For Proton Ct Using Spot Profile Rather Than Bragg Peak Location, Brett Albert Ruben Jan 2025

Novel Methodology And Proof-Of-Concept For Proton Ct Using Spot Profile Rather Than Bragg Peak Location, Brett Albert Ruben

Open Access Dissertations

Proton radiation therapy offers a highly precise method for cancer treatment, theoretically providing superior dose deposition characteristics compared to conventional X-ray radiation therapy. Its steep and finite dose fall-off region allows for superior tumor coverage while reducing, though not eliminating, dose to surrounding healthy tissue. However, its full potential is limited by range uncertainties, particularly those arising from the reliance on X-ray-based imaging methods called computed tomography (CT) for proton-based treatment. CT image Hounsfield Units (HU) must be converted to stopping power ratios (SPR) as these ratios are the clinically relevant value for accurately planning particle interactions during proton therapy. …


Confronting The Seaport Resilience Gap: Incentives, Frameworks, And Case Studies For Enhancing Resilience To Natural Hazards In Port Planning And Policy, Rosemarie Fusco Jan 2025

Confronting The Seaport Resilience Gap: Incentives, Frameworks, And Case Studies For Enhancing Resilience To Natural Hazards In Port Planning And Policy, Rosemarie Fusco

Open Access Dissertations

This dissertation investigates the critical issue of seaport resilience, focusing on the gaps in resilience planning and the role of incentives in motivating resilience investment. The research arc addresses the question: What incentivizes seaports to increase natural hazard resilience (NHR)? It is organized into three interconnected manuscripts, each examining distinct aspects of the problem.

The first manuscript critically examines the resilience planning approaches of Small Island Developing States (SIDS) as outlined in their National Adaptation Plans (NAPs), highlighting the limited consideration of seaports despite their critical role in economic and social connectivity. SIDS offer critical insight into seaport resilience due …


Textual Sediments: Genre And The Planetary Novel, William Bowden Jan 2025

Textual Sediments: Genre And The Planetary Novel, William Bowden

Open Access Dissertations

This dissertation investigates how twenty-first-century prose fiction navigates the ecological and temporal dimensions of planetary crisis. In response to accelerating pressures - climate change, ecological collapse, and the intensification of capitalist modernity - literary studies has turned increasingly to the planetary as a conceptual frame. Yet this shift has often outpaced the development of adequate critical vocabularies and narrative methodologies. By drawing on ecocriticism, narrative theory, phenomenology, and related fields, Textual Sediments proposes a new framework for reading what it terms the planetary novel: a sedimentary genre characterized by temporal layering, formal hybridity, and a recursive engagement with scale. Through …


Beyond The Phonon Gas Model (Pgm): Unraveling The Unique Mechanistic Processes Dictating Thermal Transport In Highly Anharmonic And Disordered Materials, Sandip Thakur Jan 2025

Beyond The Phonon Gas Model (Pgm): Unraveling The Unique Mechanistic Processes Dictating Thermal Transport In Highly Anharmonic And Disordered Materials, Sandip Thakur

Open Access Dissertations

Thermal transport in nonmetallic solids has traditionally been described by the phonon gas model (PGM), in which heat is carried by weakly interacting phonon quasiparticles in an ordered crystalline lattice. However, this model breaks down in materials characterized by strong anharmonicity, dynamic disorder, or structural complexity, features prevalent in many next-generation materials used in energy conversion, optoelectronics, and thermal management. This dissertation investigates thermal transport in such complex materials, including metal halide perovskites (MHPs), covalent organic frameworks (COFs), metal organic frameworks (MOFs), and 2D-3D heterostructures, through large-scale molecular dynamics (MD) simulations and frequency-resolved spectral analyses.

In MHPs, the work reveals …


Quantifying Mixotrophy Potential As A Function Of Environmental And Biological Drivers In Coastal And Estuarine Plankton Communities, Erica Ewton Jan 2025

Quantifying Mixotrophy Potential As A Function Of Environmental And Biological Drivers In Coastal And Estuarine Plankton Communities, Erica Ewton

Open Access Dissertations

The discovery of mixotrophic plankton has bridged gaps in nutrient cycling budgets and altered the understanding of food webs and energy transfer. Mixotrophic plankton are capable of simultaneous or sequential photosynthesis and heterotrophy, providing multiple avenues of nutrition and thus reducing limitations that affect specialists. These energy dense cells provide increased biomass for higher trophic levels, which may increase organism sizes throughout the food web. Additionally, they may be physically denser, which alters biogeochemical cycling including carbon sequestration. The work presented here uses LysoTracker Green, an acidotropic stain that attaches to phagocytic vacuoles within potentially phagotrophic small (< 20 µm diameter) phytoplankton communities (‘mixoplankton’), to better understand their abundance, relative abundance, and growth rates in relation to the matrix of natural conditions they inhabit. Understanding the prevalence and drivers of mixoplankton is vital to better parameterize biogeochemical cycling and energy transfer in the ocean and for models that predict the fate of future oceans.In the first study, I compared the abundance of mixoplankton in the Northeast U.S. Shelf (NES) and Coastal California Current System (CCS) during two cruises in the NES in summer 2021 and one cruise in the CCS in summer 2022. These two contrasting coastal systems span the breadth of environmental conditions observed in temperate marine ecosystems and thus provided an opportunity to examine indicators of mixoplankton across temperate coastal regions. I discovered higher mixoplankton abundance in the NES than CCS yet similar population sizes of nanoeukaryotic photosynthesizers, resulting in higher relative abundance of mixoplankton in the NES than CCS. Across both systems, I found increased mixoplankton abundance associated with decreasing temperature and combined nitrate + nitrite concentrations (N+N), and increasing light intensity and Synechococcus abundance …


Investigating The Photophysical Dynamics Of Anthracene And Acridine Derivatives Using Time-Resolved Spectroscopy, Sophia Tiano Jan 2025

Investigating The Photophysical Dynamics Of Anthracene And Acridine Derivatives Using Time-Resolved Spectroscopy, Sophia Tiano

Open Access Dissertations

Anthracenes and acridines are among the simplest visible light absorbing heterocyclic and polycyclic aromatic hydrocarbons and as such are extensively used in a variety of applications including photosensitizers and fluorescent sensors. Although the photophysics of some derivatives have been studied in the past, there is still a lot of unknown fundamental information that is vital in order to optimize these molecules for particular applications. Transient absorption spectroscopy was used to study the photophysics of the 9-substituted methyl, hydroxymethyl and formyl derivatives of acridine and anthracene. The growth and decay of the triplet-triplet absorption peak were quantified for each dye in …


Stability And Global Dynamics Of Autonomous And Nonautonomous Discrete Population Models With Stocking, Harvesting, And Cooperation, Sam Habach Jan 2025

Stability And Global Dynamics Of Autonomous And Nonautonomous Discrete Population Models With Stocking, Harvesting, And Cooperation, Sam Habach

Open Access Dissertations

This dissertation investigates the local and global behavior of several classes of discrete population models involving stocking, harvesting, and cooperation. The study is divided into three major manuscripts, each offering new theoretical in sights, bifurcation results, and applications to real-world data.

In Manuscript 1, we study the Beverton-Holt population models with constant and proportional stocking and harvesting, as well as sigmoid Beverton-Holt models under constant stocking and harvesting, both in autonomous and non-autonomous settings. We analyze stability and explore global dynamics using established local and global dynamics theorems, bifurcation theory, and explicit solutions when available. Special attention is given to …


A Socio-Ecological Investigation Of Ulithian Spearfishing, Joshua Pi Jan 2025

A Socio-Ecological Investigation Of Ulithian Spearfishing, Joshua Pi

Open Access Dissertations

Coral reef socio-ecological systems (SESs) characterize the interconnected relationships between coral reef ecosystems and reef-dependent communities. One such SES exists in Ulithi Atoll, Federated States of Micronesia, where Ulithians fish, steward, and govern their reefs through customary marine tenure, traditional ecological knowledge, and cultural taboos. In recent decades, rapid modernization in Ulithi has introduced new fishing technologies, transformed fishing practices, and ultimately reshaped the functioning of Ulithi’s traditional SES. One significant change was the introduction of spearfishing during the mid-20th century, which is more selective and individualistic compared to other community-centric fishing methods that have existed for generations. This …


Coupled Numerical Modeling Of Wave-Current Interactions In Tropical Cyclones, Angelos Papandreou Jan 2025

Coupled Numerical Modeling Of Wave-Current Interactions In Tropical Cyclones, Angelos Papandreou

Open Access Dissertations

This Ph.D. dissertation presents a numerical modeling study of wave-current interactions in tropical cyclones. Chapter 1 focuses on wave-current interaction in shallow water during hurricane landfall, when strong winds often generate severe storm surges that dramatically raise water levels and cause significant damage to human lives and property. Large waves generated by these winds further amplify storm surges, making it necessary to couple storm surge models with wave prediction models. Currently, two-dimensional coupled storm surge-wave models incorporate the effect of waves on the storm surge through the forcing of radiation stress gradients. However, recent studies on wave-current interactions indicate that …


Ultra-Rapid Electrophilic Cysteine Arylation Using Pyridinium Salts, Bradley M. Lipka Jan 2025

Ultra-Rapid Electrophilic Cysteine Arylation Using Pyridinium Salts, Bradley M. Lipka

Open Access Dissertations

Small molecule-based bioconjugation enables in vitro and in vivo functionalization of proteins and peptides, significantly expanding the chemical space of biomacromolecules. Among these transformations, nucleophilic aromatic substitution (SNAr) of cysteine residues is a widely employed strategy for protein bioconjugation.

Although many reagents facilitate cysteine arylation, they are disadvantageous in two crucial aspects - limited synthetic modularity and undesired hydrophobicity. First, conventional cysteine arylating reagents are frequently activated by multiple electron-withdrawing groups (EWGs) on a single aromatic ring, leaving few synthetic handles to derivatize the reagents for advanced applications. Second, these labeling reagents are generally hydrophobic in nature and …


A Multispectral Analysis Of High Redshift Quasars And Their Energy Production Mechanisms, Erik Carlson Jan 2025

A Multispectral Analysis Of High Redshift Quasars And Their Energy Production Mechanisms, Erik Carlson

Open Access Dissertations

We present a complete sample of radio-loud (P3.0 GHz = 1027.26 W/Hz) high-redshift (z ≥ 2.5) quasars in the Northern Hemisphere (δ ≥ 0). Each source was imaged with a user-defined imaging protocol developed for the Very Large Array Sky Survey. Higher-resolution images were generated from archival observations and new Enhanced Very Large Array observations (Project Code: 24B-010).  We produced 407 images of galaxies, where we are likely the first humans to see them. Twenty of these sources were high-redshift jets which increased the number of known high-redshift jets by 69%. This sample represents one of the largest …


Review Of 3d Data Acquisition For Bioarcheology, Forensic Anthropology, And Archeology, Alexander E. Curry Jan 2025

Review Of 3d Data Acquisition For Bioarcheology, Forensic Anthropology, And Archeology, Alexander E. Curry

Nebraska Anthropologist

3D Data Acquisition for Bioarcheology, Forensic Anthropology, and Archeology (2019) by Noriko Seguchi and Beatrix Dudzik is a first of its kind text that looks to educate the buddings 3D analyst on the popular methods and practices of data acquisition within contemporary 3D imaging software. While the text does assume a lot of the reader heading into it, especially so mathematically, the authors do a wonderful job explaining how 3D imaging works, and then how to accurately and precisely collect data from these images. Being sure to explain potential sources of error and how to present and interpret the data …


Data Injustice In Global Justice, Asaf Lubin, Cherry Tang Jan 2025

Data Injustice In Global Justice, Asaf Lubin, Cherry Tang

Articles by Maurer Faculty

In May 2020, the United Nations Secretary-General unveiled a sweeping “Data Strategy for Action by Everyone, Everywhere,” seeking to unlock the UN’s “full data potential.” The International Criminal Court’s Office of the Prosecutor followed suit, declaring in 2023 its intent to acquire advanced cyber forensic tools so as to hold the “widest range of digital evidence globally.” Across international institutions, data-driven governance has become the norm, with humanitarian agencies and tribunals transforming into “data hubs and information clearinghouses.” This Article critiques the unfettered datafication of global justice by international courts and organizations. These entities have aggressively expanded their data-driven operations …


Three Essays On The Interaction Between Macroeconomics, Money, And Government Bonds, Zejun Jiang Jan 2025

Three Essays On The Interaction Between Macroeconomics, Money, And Government Bonds, Zejun Jiang

Graduate Theses, Dissertations, and Problem Reports (ETD)

This dissertation, ''Essays on the Interaction between Macroeconomics, Money, and Government Bonds,” has three chapters that study how macroeconomics (e.g., inflation), government bonds, and money interact with each other. It provides insights into how households make optimal maturity choices in government bonds, how households own different types of government bond assets, and how money growth can help understand the cross-country inflation after COVID-19.

The first chapter develops an intertemporal portfolio choice model to investigate the optimal household portfolio choice for government bonds across maturities. The U.S. Treasury data displays a higher holding share of long-term government bonds. Adding uncertain labor …


Assessment Of Analytical Workflows Of Gunshot Residue Evidence And Strategies For Implementation Of Advanced Technology In Crime Laboratories., Leah D. Thomas Jan 2025

Assessment Of Analytical Workflows Of Gunshot Residue Evidence And Strategies For Implementation Of Advanced Technology In Crime Laboratories., Leah D. Thomas

Graduate Theses, Dissertations, and Problem Reports (ETD)

The rise in gun violence in the United States has increased the demand on forensic agencies to process evidence promptly and accurately. The exchange of imperceptible traces among objects, suspects, and victims can provide critical insights into the interactions and sequence of events during a crime. Gunshot residue (GSR) is a type of trace evidence that holds significant investigative value in shooting reconstructions. GSR can help identify potential shooters, intermediate targets, and bullet trajectories; however, its analysis is often expensive and time-consuming. Consequently, there is an urgent need for more effective solutions.

Methods for on-site screening can significantly streamline forensic …


Girl Gamers, Online Community, And Social Identity Theory: The Role Of Positive Distinction Strategies On Group Engagement On R/Girlgamers, Rachael Green Jan 2025

Girl Gamers, Online Community, And Social Identity Theory: The Role Of Positive Distinction Strategies On Group Engagement On R/Girlgamers, Rachael Green

Graduate Theses, Dissertations, and Problem Reports (ETD)

Identity theorists have studied the complex relationship between gender and gaming for over two decades, but research on how women persist in gaming communities despite harassment remains underdeveloped. Grounded in Social Identity Theory, this dissertation examines the subreddit r/GirlGamers to evaluate the prevalence and impact of positive distinction strategies in countering identity threats. Based on a mixed-methods approach, the findings highlight three key strategies (group permeability, social creativity, and social competition) alongside themes of emotion, structural inequality, and interpersonal violence. Statistical tests indicate that posts employing at least one positive distinction strategy receive significantly more upvotes and comments than those …


Free Energy Approaches To Understanding The Mechanism Of Membrane-Active Peptides, Hannah R. Scott Jan 2025

Free Energy Approaches To Understanding The Mechanism Of Membrane-Active Peptides, Hannah R. Scott

Graduate Theses, Dissertations, and Problem Reports (ETD)

Cancer is a leading cause of death in the world today. Current methods of treatment fail to distinguish the difference between cancer cells and cells of healthy tissue, leading to off-target effects, often with terminal outcomes. A potential solution to this challenge is to target the cancer cells’ microenvironment. One universal characteristic across all cancer cells is the acidic extracellular environment. The pH-Low Insertion Peptide (pHLIP) is a membrane-active peptide with acid-sensitive function, undergoing folding and insertion into a transmembrane alpha-helix. pHLIP is a promising candidate to be used to deliver anti-cancer agents exclusively to cancer cells. Although the mechanism …


Neural And Computational Approach To Understanding Environmental Modulation Of Behavioral Identity In Zebrafish, John W. Hageter Jan 2025

Neural And Computational Approach To Understanding Environmental Modulation Of Behavioral Identity In Zebrafish, John W. Hageter

Graduate Theses, Dissertations, and Problem Reports (ETD)

Organisms rely on behavior for survival. Animals engage in behaviors that allow for feeding, mating, exploring and navigating their environment among others. Necessary for these behaviors to develop are the environmental factors and underlying circuitry which make behavior possible. Specifically, how the environment guides underlying neural circuitry to develop unique facets or phenotypes of a larger behavior are key to understanding why unique behaviors exist. In this thesis, I build foundational evidence for determining these mechanisms through the use of the zebrafish local search behavior. This is a behavior that zebrafish employ following the loss of environmental illumination where they …


A Paleobiological And Paleoecological Analysis Of Mississippian Trilobites With Segmentation Abnormalities, April Catherine Cerami Jan 2025

A Paleobiological And Paleoecological Analysis Of Mississippian Trilobites With Segmentation Abnormalities, April Catherine Cerami

Graduate Theses, Dissertations, and Problem Reports (ETD)

Trilobites are a well-preserved group of arthropods, with a fossil record extending from the Cambrian to the end of the Permian. Abnormalities, such as injuries or teratological defects, have been observed and described in multiple individuals, although investigating how these abnormalities occur in populations has been largely overlooked.

One possible cause of abnormalities in marine arthropods is heavy metal pollution. Such metals can leave individuals more susceptible to teratological deformities and injuries, interfering with the molting and healing process. Here, methods for analyzing elemental composition and preservation of the trilobite cuticle were refined, finding that 30 μm thin sections are …


Multi-Scale Dynamic Modeling, Validation, And Uncertainty Quantification Of Radial Flow Fixed Bed Contactors For Co2 Capture, Ana Flávia De Alencar Arraes Monteiro Jan 2025

Multi-Scale Dynamic Modeling, Validation, And Uncertainty Quantification Of Radial Flow Fixed Bed Contactors For Co2 Capture, Ana Flávia De Alencar Arraes Monteiro

Graduate Theses, Dissertations, and Problem Reports (ETD)

One of the key sources of carbon dioxide emissions to the environment is fossil fuel combustion for power generation. Post-combustion CO2 capture using amine-based solvents is currently the most matured process. However, amines are corrosive and lead to degradation products at even moderate temperatures generating environmental pollutants, and require high energy for regeneration. Solid sorbents are a promising alternative. They possess lower regeneration energy, thermal stability, and have highly tunable porous structures with large surface area that can help in achieving high loading and high adsorption rates. This work focuses on mathematical modeling of CO2 adsorption/desorption processes using solid sorbents. …


Investigation Of Protein-Ligand Binding Interactions Through The Computational Methods Of Molecular Dynamics And Graph Neural Networks, Alexander Benjamin Wroe Jan 2025

Investigation Of Protein-Ligand Binding Interactions Through The Computational Methods Of Molecular Dynamics And Graph Neural Networks, Alexander Benjamin Wroe

Graduate Theses, Dissertations, and Problem Reports (ETD)

Studies in protein ligand binding are a significant focus in the field of medicinal chemistry

and biochemistry, facilitating a greater understanding of the structure-function relationship

of the protein and controlling function via drug development. In this research, we identify

new binding sites for lipids on the microbial membrane protein, proteorhodopsin, and apply

machine learning approaches to accelerate the generation of binding affinity-like data for the

use in the identification of potential small molecule drugs. The platelet activating factor

receptor. Cardiolipin, a lipid in membranes, and proteorhodopsin, a microbial proton pump,

are both commonly found in microbial membranes, but little is …


International Students’ Perceptions And Experiences Of Institutional Diversity Initiatives And Self-Authorship Attainment: A Mixed Methods Study, Sandra Ayivor Jan 2025

International Students’ Perceptions And Experiences Of Institutional Diversity Initiatives And Self-Authorship Attainment: A Mixed Methods Study, Sandra Ayivor

Graduate Theses, Dissertations, and Problem Reports (ETD)

Higher education institutions in the United States have responded to years of discrimination through several diversity initiatives. Although research has indicated the merits of such initiatives on student development, the outcomes are not uniform across all student populations. Moreover, student development discourses have often excluded the experiences of international students. Employing a convergent mixed methods approach, this study investigated the perceptions and experiences of international students at a flagship land-grant higher education institution in the Appalachian region of the United States regarding institutional diversity initiatives and their self-authorship based on some demographic characteristics (i.e., gender, age, marital status, religion, continent, …


A Generalized Coherence Framework For Quantifying Input Contributions In Multi-Input Systems With Correlated Or Uncorrelated Inputs, Nolan H. Howes, Matthew S. Allen, Dario Farina, Steven Knight Charles Jan 2025

A Generalized Coherence Framework For Quantifying Input Contributions In Multi-Input Systems With Correlated Or Uncorrelated Inputs, Nolan H. Howes, Matthew S. Allen, Dario Farina, Steven Knight Charles

Faculty Publications

In multi-input systems, it is often necessary to quantify the contribution of each input to an output. Such contribution analysis is frequently performed using coherence. However, when correlation is present between inputs, existing coherence measures do not accurately quantify the contribution of individual inputs, except in special cases. Here we propose an expanded coherence framework that enables contribution analysis in any multi-input system, regardless of input correlation. We bridged the gap by defining three new coherence measures: component, excluded, and isolated coherence. Component coherence is an intermediate measure that decomposes measured output power into components attributable to inputs directly vs …


Flower Cluster Matching Utilizing The Unscented Transform For Robotic Pollination, Andy Chu Jan 2025

Flower Cluster Matching Utilizing The Unscented Transform For Robotic Pollination, Andy Chu

Graduate Theses, Dissertations, and Problem Reports (ETD)

The use of automated systems for agriculture is integral to keeping the food supply secure. Both industry and academia are exploring and applying methods to increase the yield of plants in environments ranging from outdoor fields to greenhouses. Specifically, many automated systems use continuous monitoring of plants to track plant health and yield. The use of computer vision is necessary when it comes to precision operations that use robotics. Today, robots are trained to weed, harvest, and pollinate. To accomplish these tasks autonomously, a lot of data is needed, which is where spatial-temporal observations of the plants are being recorded …


Design And Simulation Of An Ai-Powered Autonomous Quadrotor Framework For Search And Rescue Operations, James J. Shope Jan 2025

Design And Simulation Of An Ai-Powered Autonomous Quadrotor Framework For Search And Rescue Operations, James J. Shope

Graduate Theses, Dissertations, and Problem Reports (ETD)

Unmanned aerial vehicles (UAVs), particularly quadrotor platforms, have proven to be indispensable tools for search and rescue (SAR) teams due to their maneuverability, rapid deployment, and affordable operation. The current SAR use cases of quadrotors span from aerial surveillance to mission planning and strategic deliveries. However, most SAR applications remain passive or semi-autonomous, such that they rely on human-operated control or data assessment. Advancements in autonomous control strategies bring about a future where a single SAR operator can program and deploy several UAVs. This thesis details the development and simulation of a fully autonomous, AI-powered quadrotor framework capable of detecting …


Development And Application Of Computational Tools For Data-Driven Materials Science., Logan L. Lang Jan 2025

Development And Application Of Computational Tools For Data-Driven Materials Science., Logan L. Lang

Graduate Theses, Dissertations, and Problem Reports (ETD)

Modern materials science generates vast amounts of data from computational simulations and experiments, creating significant challenges for data processing and analysis. This thesis addresses these challenges through the development and application of computational tools within the framework of Material Data Science (MDS). Contributions span the four pillars of MDS: Material/Molecular Data, Algorithms, Databases, and High-Throughput Processes—with a primary focus on the Algorithm, Data, Database pillars.

For the Algorithm pillar, two Python libraries were developed to streamline common analysis tasks. PyProcar simplifies the post-processing and visualization of electronic structure data (band structures, density of states, Fermi surfaces) obtained from various Density …


Enhancing Pillar Stability Assessment In Underground Limestone Mines Using Lamodel: Integrating Empirical Strength Equations For Improved Ground Control, Alim Elibol Jan 2025

Enhancing Pillar Stability Assessment In Underground Limestone Mines Using Lamodel: Integrating Empirical Strength Equations For Improved Ground Control, Alim Elibol

Graduate Theses, Dissertations, and Problem Reports (ETD)

Underground stone mining accounts for approximately 21% of all underground mining operations in the United States, with more than 2,000 workers employed in this sector as of 2019. Ground control failures, particularly those involving massive pillar collapses and roof falls, pose significant safety hazards, contributing to 40% of fatalities and 15% of lost workdays since 2006. Several massive pillar collapses have occurred in active limestone mines from 2015 to 2021, and a fatal incident was reported in January 2022 in a mine operating within the Loyalhanna formation. Given these risks, accurate stability assessment tools are essential for improving mine safety. …


Mathematical Contributions To The Study Of Chemotaxis And Cell Signaling, Hajr Zam Jan 2025

Mathematical Contributions To The Study Of Chemotaxis And Cell Signaling, Hajr Zam

Graduate Theses, Dissertations, and Problem Reports (ETD)

This dissertation presents results from two mathematical projects concerned with the biology of cells. Chapter 1 provides biological background and places the two mathematical problems in the context of cell signaling. The larger project, with Prof. H. Hattori on a chemotaxis model is presented in Chapters 3 and 4. Work with Prof. \'{A}. Hal\'{a}sz on a chemical reaction network system with linear multimers and two types of labels is presented in Chapter 2. The chemotaxis system describes the one-dimensional dynamics of a species of cells with two chemical species, a chemo-attractant and chemo-repellent. The goal is to analyze the behavior …


Three Essays On Education And Health Economics, Kalvin Mudrow Jan 2025

Three Essays On Education And Health Economics, Kalvin Mudrow

Graduate Theses, Dissertations, and Problem Reports (ETD)

The first chapter explores the impact of online education on student outcomes by comparing students pre-2020 school closures to students post-2020 school closures. Using student-level panel data from a large U.S. school district spanning 2017-2023 and two outcome variables, reading tests and end-of-level exams, I estimate the effects on different demographic groups, the dynamics of these effects over time, and how these effects differ across students ages. I find a significant decline in student performance after the move to online learning, with additional adverse effects on students who are classified as low-income, female, special education, or ELL. Mechanisms contributing to …