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2026

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Detecting Poisoning Attacks In The Rag Systems Using Multi-Tier Anomaly Detection, Somtochukwu Orizu Jan 2026

Detecting Poisoning Attacks In The Rag Systems Using Multi-Tier Anomaly Detection, Somtochukwu Orizu

Electronic Theses and Dissertations

Retrieval-Augmented Generation (RAG) systems aim to enhance the capabilities of language models by retrieving external knowledge during inference. However, the process of retrieving knowledge introduces new security vulnerabilities to these models, specifically through the possibility of retrieval poisoning attacks in which adversarial documents are added to the system knowledge base to poison the language model’s responses. Although there have been a variety of defenses proposed for retrieval poisoning attacks, limited work has been done in the area of anomaly detection in embedding spaces as a general defense against multiple retrieval poisoning attack strategies. This thesis investigates two embedding-space anomaly detection …


Demographic Impact And Diagnostic Evaluation Of Mycoplasma Ovipneumoniae In Bighorn Sheep Of The Pine Ridge Badlands, Jeffrey Tillery Jan 2026

Demographic Impact And Diagnostic Evaluation Of Mycoplasma Ovipneumoniae In Bighorn Sheep Of The Pine Ridge Badlands, Jeffrey Tillery

Electronic Theses and Dissertations

Mycoplasma ovipneumoniae (M. ovi) decimates bighorn sheep (Ovis canadensis) populations through acute die-offs followed by years or decades of failed lamb recruitment. Test-and-remove management has emerged as the primary intervention to restore population growth, and this thesis quantifies the demographic costs of endemic M. ovi infection and evaluates the diagnostic tools upon which this strategy depends. I quantified vital rates across five bighorn sheep subherds (four infected, one uninfected) on the Pine Ridge Reservation (2023–2025), supplemented by pre-outbreak data (2017–2018) from the North Unit of Badlands National Park. Infected subherds declined (λ = 0.965, 95% CrI: 0.813–1.039) while the uninfected …


Securing Smart Agriculture With Communication-Efficient Federated Unlearning, Ujjwal Pudasaini Jan 2026

Securing Smart Agriculture With Communication-Efficient Federated Unlearning, Ujjwal Pudasaini

Electronic Theses and Dissertations

This thesis addresses the data poisoning attack in smart agricultural systems using federated unlearning, where the contribution of compromised field devices must be removed from the global model under communication constraints. We propose FedSCAN, a three-phase framework that identifies critical layers based on parameter sensitivity, classifies active neurons within these layers through relative weight change analysis, and performs unlearning via sparse low-rank adaptation to active neurons while freezing base model parameters. FedSCAN limits computational overhead to a compact parameter subset, enabling devices to participate in a communication-efficient manner. Experimental results on four datasets demonstrate that FedSCAN achieves up to 426.3× …


Production Of Fungal Biomass And Crude Chitin From Cheese Whey: Effects Of Whey Type And Lactose Hydrolysis On Aspergillus Niger And Trichoderma Reesei, Anye Catharine Nora Drum Jan 2026

Production Of Fungal Biomass And Crude Chitin From Cheese Whey: Effects Of Whey Type And Lactose Hydrolysis On Aspergillus Niger And Trichoderma Reesei, Anye Catharine Nora Drum

Electronic Theses and Dissertations

Chitin is a biodegradable and biocompatible biopolymer with broad applications in the food, biomedical, pharmaceutical, and packaging industries. Conventional chitin production from crustacean shells is associated with seasonal availability, intensive chemical processing, and environmental concerns, creating interest in more sustainable alternatives. Filamentous fungi represent a promising source of chitin because of their rapid growth and ability to utilize low cost agro-industrial residues. This study evaluated the feasibility of producing fungal biomass and crude chitin from cheese whey through submerged fermentation while investigating the effects of whey type and enzymatic lactose hydrolysis on fungal growth, substrate utilization, and wastewater remediation. Aspergillus …


Plant-Insect Interactions In Great Plains Restoration And Invasion Ecology, Joseph H. Cammarano Jan 2026

Plant-Insect Interactions In Great Plains Restoration And Invasion Ecology, Joseph H. Cammarano

Electronic Theses and Dissertations

Prairie ecosystem loss and invasive plant species are major ecological problems in the Great Plains. Plant-insect interactions have important consequences for both the restoration of prairie ecosystems and management of invasive plant species. Pollinating insects are vital to the sustainability of prairie ecosystems, and herbivorous insects can provide biological control of invasive plant species. Understanding how restoration strategies may influence potential pollinator communities can have important consequences for restoration sustainability and success and understanding how biological control strategies may help manage invasive plant populations can also help land managers reach restoration and conservation goals. In Ch. 2, I sought to …


Data-Driven Decision-Making Frameworks For Energy Procurement And Dynamic Pricing In Electric Vehicle Charging Networks, Pallavi Khanal Jan 2026

Data-Driven Decision-Making Frameworks For Energy Procurement And Dynamic Pricing In Electric Vehicle Charging Networks, Pallavi Khanal

Electronic Theses and Dissertations

The continued growth of electric vehicles (EVs) is increasing the demand for charging infrastructure and creating new operational challenges for charging network operators (CNOs). Uncertainty in charging demand, electricity market prices, and user charging behavior can significantly impact both the economic performance and reliability of charging network operations. To address these challenges, this thesis develops an integrated data-driven framework that combines charging demand modeling, risk-aware energy procurement, machine learning, and reinforcement learning for intelligent EV charging network operation. The research begins by developing queueing-based models to characterize EV charging demand under time-varying and stochastic arrival conditions. Time-varying Mt/M/1 and Mt/M/c …


Primary Avian Tracheal Cell Models For The Isolation Of Emerging Avian Metapneumovirus Strains, Tricia Serrao Jan 2026

Primary Avian Tracheal Cell Models For The Isolation Of Emerging Avian Metapneumovirus Strains, Tricia Serrao

Electronic Theses and Dissertations

The emergence of avian metapneumovirus (aMPV) subgroups A and B in the United States poultry industry has created an urgent need for standardized, host-specific diagnostic platforms. Historically, reliance on continuous, multi-species cell lines has limited the primary isolation of field strains and introduced potential adaptation artifacts. To address these challenges, this research first established and characterized a reproducible primary cell culture system derived from the tracheal tissues of 1-day-old turkey poults. This system was maintained in an optimized DMEM/F-12 formulation supplemented with 5% FBS, EGF, and ITS, with early-passage cultures achieving 90% confluence within 24 to 48 hours. Morphological and …


Competitive And Priority Effects Of Native Cool-Season Grasses On Invasive Bromus Species In The Northern Great Plains, Tyler Michael Geltmacher Jan 2026

Competitive And Priority Effects Of Native Cool-Season Grasses On Invasive Bromus Species In The Northern Great Plains, Tyler Michael Geltmacher

Electronic Theses and Dissertations

Native grasslands and restoration sites in the Northern Great Plains face pressure from invasive cool-season grass species, such as smooth brome (Bromus inermis) and cheatgrass (Bromus tectorum). Native cool-season grass species may compete in the same niche as the invaders and provide resistance to invasion of existing or restored grasslands. Green needlegrass (Nassella viridula) and junegrass (Koeleria macrantha) were evaluated in this study for competitive effect and priority effect against invasive bromes to inform management decisions. Greenhouse studies were conducted to evaluate competitive ability of the two native species as well as how priority influences competition. In my first chapter, …


Investigating The Cumulative Effect Of Nutrition Education And Nutrition Assistance On Measures Of Participant Health, Adity Chowdhury Kankon Jan 2026

Investigating The Cumulative Effect Of Nutrition Education And Nutrition Assistance On Measures Of Participant Health, Adity Chowdhury Kankon

Electronic Theses and Dissertations

This study examined the individual and combined associations of participation in the Expanded Food and Nutrition Education Program (EFNEP) and nutrition assistance programs with diet quality and biomarkers of chronic disease risk. Multistate longitudinal data were analyzed using triple difference-in-differences regression models for body mass index (BMI), systolic and diastolic blood pressure, hemoglobin A1c (HbA1c), and Diet Quality Index (DQI). EFNEP participation was associated with a reduction in BMI over time among participants not receiving nutrition assistance, but this association was attenuated among assistance participants. A similar differential pattern was observed for HbA1c. No significant differential changes were found for …


The Fate And Removal Of E. Coli Across Liquid And Sludge Treatment Stages In An Activated -Sludge Water Resource Recovery Facility, Shrawan Tandukar Jan 2026

The Fate And Removal Of E. Coli Across Liquid And Sludge Treatment Stages In An Activated -Sludge Water Resource Recovery Facility, Shrawan Tandukar

Electronic Theses and Dissertations

This study evaluates the fate and removal efficiency of Escherichia coli (E. coli) across both liquid and sludge treatment processes at a full-scale activated sludge water resource recovery facility (WRRF) in Brookings, South Dakota. Understanding pathogen reduction within wastewater treatment systems is critical for protecting public health and ensuring regulatory compliance, particularly in facilities practicing water reuse and biosolids management. Liquid and sludge samples were collected from multiple treatment stages between January and July 2025 and analyzed using the IDEXX Colilert Quanti-Tray 2000 method. This study quantifies E. coli concentrations throughout the treatment train to assess removal performance and identify …


A Framework For Reliable Domain Ai: Knowledge-Grounded Data And Logic-Graph Reasoning, Yangxiao Bai Jan 2026

A Framework For Reliable Domain Ai: Knowledge-Grounded Data And Logic-Graph Reasoning, Yangxiao Bai

Electronic Theses and Dissertations

Large language models (LLMs) perform well on general tasks, yet their deployment in specialized, high-stakes domains such as public health remains unreliable. Models hallucinate facts, combine multi-step evidence incorrectly, and retrieve context that corrupts downstream reasoning. Three root causes underlie these failures: training data that underrepresents rare but critical domain themes, reasoning that is opaque and unverifiable, and evidence use that cannot be re-checked when the evidence changes. This dissertation addresses all three. First, we introduce HDBSCAN_SSA, a coarse-to-fine topic-modeling pipeline that couples density-based clustering with a novel Semantic Seed Aggregation algorithm. Using samples drawn from a larger corpus of …


Spatio-Temporal Demand Forecasting For Optimizing Electric Vehicle Charging Network Operations, Subhamyu Mani Nepal Jan 2026

Spatio-Temporal Demand Forecasting For Optimizing Electric Vehicle Charging Network Operations, Subhamyu Mani Nepal

Electronic Theses and Dissertations

The primary objective of this thesis is to create a framework for modeling, forecasting Electric Vehicle load demand and optimizing the EV charging network operation for Charging network operators. As EV’s popularity grows accurate forecasting of EV charging demand and its effect on the distribution network is critical for the efficient planning and operation of charging infrastructure, as well as for enabling Charging Network Operators to participate effectively in wholesale electricity markets. The first part of the work develops Mt /M/1 & Mt /M/c queuing models calibrated using real-world EV charging data to characterize station-level operations under time-varying arrival rates. …


Page Evidence Promotion For Open-Domain Multimodal Document Question Answering, Abdolhossein Erfanshekooh Jan 2026

Page Evidence Promotion For Open-Domain Multimodal Document Question Answering, Abdolhossein Erfanshekooh

Electronic Theses and Dissertations

Open-domain multimodal document question answering requires retrieving a small set of answer-bearing pages from a large document collection before a vision-language model can generate an answer. Although modern retrieval systems may return hundreds or thousands of candidate pages, the answer model typically receives only the highest-ranked few. Consequently, relevant evidence may already be present in the candidate pool yet remain unavailable to the answer model because it is ranked below the reader cutoff. This thesis identifies this retrieval-to-reader gap as a page evidence promotion problem and proposes a framework for diagnosing and addressing it. First, page-level pseudo-supervision is derived from …


Integration Of Ders Volt-Var Dynamic Constraint Into Time-Coupled Optimal Power Flow For System Stability, Shadrack T. Asiedu Jan 2026

Integration Of Ders Volt-Var Dynamic Constraint Into Time-Coupled Optimal Power Flow For System Stability, Shadrack T. Asiedu

Electronic Theses and Dissertations

The transition toward power systems with higher levels of inverter-based generation requires operating models that account for the dynamic support available from distribution-connected resources. Although inverter-based DERs can provide fast reactive-power support through functions such as Volt–VAR control, conventional optimal power flow models generally represent these resources as static power injections. In addition, transmission-level dispatch commonly represents the downstream distribution system as an aggregated load and does not explicitly consider the voltage at the point of common coupling. Consequently, an OPF solution may satisfy the transmission-bus voltage constraints while producing an operating point at which the downstream DERs do not …


The Influence Of Controlled Intake And Anabolic Implant Timing On Growth Performance And Carcass Traits In Feedlot Ruminants, Justin J. Delver Jan 2026

The Influence Of Controlled Intake And Anabolic Implant Timing On Growth Performance And Carcass Traits In Feedlot Ruminants, Justin J. Delver

Electronic Theses and Dissertations

The objective of this dissertation was to evaluate how previous plane of nutrition and anabolic implant timing interact to influence growth performance, composition of growth, and the carcass characteristics in ruminants. Three experiments were conducted using cattle and sheep models to determine the metabolic adaptations driving compensatory growth. In experiment 1, yearling beef steers (n = 192) were fed ad libitum for 141 days (ADLIB) or restricted to 92% of ad libitum intake for 56 (RES56) or 86 (RES86) days followed by realimentation. Cumulative dry matter intake (DMI) was reduced in both restricted groups (P = 0.002) with no difference …


Effect Of Increasing Potency Of Steroidal Implants In Beef Steers At Weaning From Dry-Lot To Finish, Weston Joseph Peschel Jan 2026

Effect Of Increasing Potency Of Steroidal Implants In Beef Steers At Weaning From Dry-Lot To Finish, Weston Joseph Peschel

Electronic Theses and Dissertations

The receiving phase is a stressful transition period in beef production. Newly weaned cattle are offered low-energy, high-forage diets promoting lean tissue and bone development prior to the finishing phase. Steroidal implants containing trenbolone acetate (TBA) and estradiol benzoate (EB) enhance lean gain. Aggressive early implant exposure has been shown to negatively impact intramuscular fat deposition. This two-part study evaluated the initial and carryover effects of increasing doses of combined TBA and EB weaning implants on growth performance, serum metabolites, and carcass traits. In Exp. 1, newly weaned Charolais × Red Angus crossbred beef steers [n = 240 initially; body …


Modeling Heterogeneous Trajectories Of Chronic Kidney Disease Progression With Finite Mixture Models Using The All Of Us Dataset, Yahaya Mumuni Musah Jan 2026

Modeling Heterogeneous Trajectories Of Chronic Kidney Disease Progression With Finite Mixture Models Using The All Of Us Dataset, Yahaya Mumuni Musah

Electronic Theses and Dissertations

Background: Chronic kidney disease (CKD) does not progress uniformly across patients, and a single average trajectory often fails to capture this heterogeneity. Understanding variation in disease progression is important for improving risk stratification and clinical management. 
Objectives: This study aims to characterize the heterogeneity of chronic kidney disease (CKD) progression using longitudinal estimated glomerular filtration rate (eGFR) data and to identify factors associated with distinct progression trajectory patterns. 
Methods: A longitudinal cohort study was conducted using data from the All of Us} Research Program collected between April 23, 2002, and October 1, 2023. Adult participants with repeated eGFR measurements were …


Enzyme Susceptibility And Functionality Of High Protein Retentates And Reconstituted Ingredients, Khushi Dubey Jan 2026

Enzyme Susceptibility And Functionality Of High Protein Retentates And Reconstituted Ingredients, Khushi Dubey

Electronic Theses and Dissertations

This thesis explores the effects of processing history on the enzymatic susceptibility and functional properties of high-protein dairy ingredients, with a specific focus on ultrafiltered (UF) and microfiltered (MF) retentates and spray-dried powders. While retentates and powders are often used interchangeably in industrial applications, processing steps, such as drying, can induce structural and physicochemical changes that affect protein functionality and enzyme accessibility. Milk protein concentrates (MPC) and micellar casein concentrates (MCC) were standardized to 10% protein and subjected to enzymatic treatments, including proteolysis (Alcalase and rennet) and crosslinking (transglutaminase and laccase). Structural modifications were evaluated using capillary gel electrophoresis, non-protein …


Effect Of Female Employment On Household Expenditure In Bangladesh, Fatema Binte Sharif Jan 2026

Effect Of Female Employment On Household Expenditure In Bangladesh, Fatema Binte Sharif

Electronic Theses and Dissertations

Female labor force participation (FLFP) in Bangladesh has increased from 29.2% in 2005–06 to 42.8% in 2022, raising important questions about household resource allocation. This study examines the impact of female employment on household expenditure patterns and challenges the traditional unitary model of decision-making. It focuses on how income controlled by women influences spending across essential and non-essential categories. The analysis uses data from the Household Income and Expenditure Survey (HIES) conducted by the Bangladesh Bureau of Statistics. This research employs Seemingly Unrelated Regression (SURE) approach to estimate budget shares for food, housing, health, education, clothing, and transport. The study …


Detecting And Characterizing Latent Subpopulations Of Classes Via Mixture Models, Andrew Simpson Jan 2026

Detecting And Characterizing Latent Subpopulations Of Classes Via Mixture Models, Andrew Simpson

Electronic Theses and Dissertations

A class of problems in statistical pattern recognition exists in which there is high-dimensional data with few realizations per class, commonly referred to as few-shot learning. Data that arises in forensic source identification, which deals with providing a probabilistic value of evidence with regard to the source of some object, falls into this class of problems. Namely, the data is sampled from a hierarchical sampling process, lives in a high-dimensional space, the number of sources (or classes) tends towards infinity, and there are few observations per source. This can be thought of as a few-shot learning problem. Because of these …


Evaluating The Potential Of Genomic Selection For Grain Yield And Yield Component Traits In South Dakota Winter Wheat, Dante Koupal Jan 2026

Evaluating The Potential Of Genomic Selection For Grain Yield And Yield Component Traits In South Dakota Winter Wheat, Dante Koupal

Electronic Theses and Dissertations

Wheat (Triticum aestivum L.) is a major cereal crop worldwide, but recent gains in grain yield (GY) have not kept pace with projected demand. GY is a highly quantitative trait with low heritability that requires multi-year, multi-location phenotyping, limiting selection efficiency. Targeting higher heritability yield component traits, such as kernel size and weight, and incorporating them into the genomic selection (GS) pipeline has the potential to accelerate genetic gain for GY. The objectives of this study were to (i) understand the relationship between GY and the kernel-size traits, including thousand kernel weight (TKW), kernel length (KL), kernel width (KW), and …


Integrating Uav-Based High-Throughput Phenotyping, Genomics, And Deep Learning To Improve Prediction Of Complex Traits In Winter Wheat, Swas Kaushal Jan 2026

Integrating Uav-Based High-Throughput Phenotyping, Genomics, And Deep Learning To Improve Prediction Of Complex Traits In Winter Wheat, Swas Kaushal

Electronic Theses and Dissertations

Accurate prediction of complex agronomic traits such as grain yield and yield components remains a central challenge in winter wheat breeding because these traits are controlled by many genes and are strongly influenced by environmental variation. The integration of high-throughput phenotyping (HTP), genomics, and advanced machine learning approaches offers new opportunities to improve predictive accuracy and accelerate genetic gain in plant breeding. This study evaluates the use of an unmanned aerial vehicle (UAV)-based multispectral phenomics combined with genomic information, and deep learning approaches to enhance the prediction of grain yield (GY), test weight (TW), grain protein content (GPC), and tiller …


Butting Heads With Respiratory Disease: Post-Epizootic Demography And Movement-Driven Spillover Risk In A Badland’S Bighorn Sheep (Ovis Canadensis) Meta-Population, Sean P. Ryder Jan 2026

Butting Heads With Respiratory Disease: Post-Epizootic Demography And Movement-Driven Spillover Risk In A Badland’S Bighorn Sheep (Ovis Canadensis) Meta-Population, Sean P. Ryder

Electronic Theses and Dissertations

Respiratory disease caused by Mycoplasma ovipneumoniae is among the most significant threats to bighorn sheep (Ovis canadensis) conservation in North America. In July 2021, contact between bighorn sheep rams and domestic sheep north of Badlands National Park (BADL), South Dakota, USA introduced M. ovipneumoniae into the Badlands bighorn sheep meta-population, triggering an epizootic that reduced the population by approximately 80%. I evaluated the post-outbreak status of this population through two complementary studies conducted from 2023 to 2025. In Chapter 1, I quantified disease prevalence, adult survival, lamb recruitment, and population growth rate (λ) using serial quantitative polymerase chain reaction (qPCR) …


Computational Fluid Dynamics Simulation Of In-Situ Plasma- Assisted Cold Spray, Lucas Degen Jan 2026

Computational Fluid Dynamics Simulation Of In-Situ Plasma- Assisted Cold Spray, Lucas Degen

Electronic Theses and Dissertations

Cold spray is a solid-state form of additive manufacturing with high versatility and widespread applicability, especially in relation to metal coatings. Many applications exist within the fields of aerospace, defense and energy systems to obtain sustainable, temperature and corrosion resistant, robust coatings. High-strength alloys and refractory metals generally encounter challenges with regards to cold spray coating adhesion and overall deposition efficiency. Heat induced methods of post-processing or in-situ treatment have been explored to encourage particle softening in the cold spray plume, as well as coating recrystallization to enhance material properties. These approaches have primarily been limited to an experimental approach, …


Transcriptomic And Epigenetic Analysis Of Dormant Grape Buds During Chilling Fulfillment, Imasha Thilakarathna Jan 2026

Transcriptomic And Epigenetic Analysis Of Dormant Grape Buds During Chilling Fulfillment, Imasha Thilakarathna

Electronic Theses and Dissertations

No abstract provided.


Improving Human Dimensions Of Conservation Planning: Challenges And Opportunities For Sustainable Conservation Outcomes, Vivian Hulugh Jan 2026

Improving Human Dimensions Of Conservation Planning: Challenges And Opportunities For Sustainable Conservation Outcomes, Vivian Hulugh

Electronic Theses and Dissertations

Conservation planning is important to ensure both ecological and social benefits of natural resources, including the maintenance of functional ecosystems and stable wildlife populations as well as the provision of resources that communities rely on. Yet, the integration of the human dimensions of conservation planning remains limited in practice. This thesis examines conservation planning in South Dakota and within Joint Venture (JV) partnerships, using qualitative methods to identify challenges and opportunities for more effective and coordinated planning. In chapter one, I examine how collaboration, public participation, and the use of climate information are integrated conservation planning in South Dakota and …


Fast And Sustainable Video Anomaly Detection With Continual Learning, Preethi Amasa Jan 2026

Fast And Sustainable Video Anomaly Detection With Continual Learning, Preethi Amasa

Electronic Theses and Dissertations

Real-time video anomaly detection systems deployed in surveillance, healthcare, and industrial environments face continuous distribution shifts in lighting, viewpoint, and activity patterns. Existing models often experience performance degradation under these conditions and may suffer catastrophic forgetting when adapting to new environments. This thesis proposes RegiGrow, a parameter-efficient continual adaptation framework built on the Flashback retrieval pipeline. RegiGrow integrates Mixture-of-Experts Low-Rank Adaptation into a frozen ImageBind encoder, enabling sequential domain adaptation without modifying the pretrained backbone. A lightweight router maps visual regime features to a distribution over LoRA experts, each specializing in a distinct normal operating regime. The central contribution is …


Investigation Of Perennial Clover Living Mulch And Reduced Tillage Effects On Weed Suppression, Crop Metrics, And Yield Of Organic Cabbage And Sweet Corn In The Northern Great Plains, Kristina Harms Jan 2026

Investigation Of Perennial Clover Living Mulch And Reduced Tillage Effects On Weed Suppression, Crop Metrics, And Yield Of Organic Cabbage And Sweet Corn In The Northern Great Plains, Kristina Harms

Electronic Theses and Dissertations

Vegetable farmers often face weed management and soil health challenges, such as nitrate leaching, soil compaction, and top-soil loss. Sustainable agriculture is a forefront of innovation compared to conventional agriculture. Living mulches, non-cash crops grown alongside cash crops, have demonstrated weed suppression and impact on the promotion of sustainable agriculture. Yet studies have not evaluated established living mulch systems on cash crop quality and yield. This study conducted in 2023, 2024, and 2025 at SDSU Southeast Research Farm, Beresford, SD, USA evaluates the impact of established ‘Dynamite’ red clover (Trifolium pratense), ‘Domino’ white clover (T. repens), and ‘Aberlasting’ white × …


The Spacetime Finite Element Method For Investigations Into Physics Ghost Systems And Time Parallel Preconditioning, Jax Wysong Jan 2026

The Spacetime Finite Element Method For Investigations Into Physics Ghost Systems And Time Parallel Preconditioning, Jax Wysong

Electronic Theses and Dissertations

This work operates on two fronts, focusing on interesting physical phenomena before turning our attention to an interesting numerical math problem. First, using the spacetime finite element method (FEM), we investigate a PDE system consisting of two Klein Gordon equations, which are coupled nonlinearly through the potential energy. The system contains a ghost (negative kinetic energy term). Systems such as these are generally deemed physically unstable, resulting in infinite energy in finite time. However, recent work has shown that this is not always the case. We investigate multiple scenarios arising from different initial conditions to characterize if/when a ghost system …


Feasibility Study For Lithium Mining In South Dakota, Neha Karna Jan 2026

Feasibility Study For Lithium Mining In South Dakota, Neha Karna

Electronic Theses and Dissertations

The increasing demand for lithium in the battery manufacturing industry, boosted by the growth of electric vehicles and smartphones, has led to concern over its sustainable supply chain in the United States. Historically, South Dakota has played a significant role in U.S. lithium production. The recent surge of interest in lithium exploration in South Dakota, specifically Black Hills, underscores the importance of evaluating the feasibility of lithium mining in Black Hills. This research aims to study the economic feasibility of a lithium mining operation in Black Hills, South Dakota. Our specific objective is to estimate cut-off grade using Lane’s model …