Digital Commons Network^™

Experimental Characterisation Of Laser Cladding Of Crniw And Crnifealzr Powders On H13 Tool Steel And Optimisation Of Process Parameters, Martin Vinoth S

Theses and Dissertations

In this work, laser cladding on H13 steel substrate with two different powder compositions CrNiW and CrNiFeAlZr has been carried out. The laser power, powder feed rate, and scanning speed were varied and the clad dimensions, aspect ratio, and dilution percentage were measured. The microhardness found in the CrNiW clad is 834 ± 20 HV0.5, which is higher than that of the CrNiFeAlZr clad (780 ± 20 HV0.5) as well as the substrate (548 ± 20 HV0.5).

The X-ray Diffraction (XRD) patterns identified the common phase creation of Ni3C and Fe3C for CrNiFeAlZr and CrNiW coatings, while the oxide formation …

Diagnostic Accuracy Of Nonword Repetition Tasks For Dual Language Learners And Monolingual Students, Elizabeth Hunt

Theses and Dissertations

Assessments for diagnosing language disorders (LD) can be biased for dual language learners (DLLs). Nonword repetition (NWR) tasks show potential as a less-biased language assessment measure for DLLs. This study explored the diagnostic accuracy of NWR tasks for diagnosing LD. There were 291 participants included in this study in first through fifth grades. Thirty-nine of the participants had LD and 86 of the participants were DLLs. Sixteen of the participants were DLLs and had LD. Monolingual participants were administered an English NWR task, and DLLs were administered both English and Spanish NWR tasks. These tasks were scored by percent phonemes …

Advancing Wood Chip Moisture Content Prediction Using Advanced Generative Ai Techniques, Daniel Esteban Marulanda

Theses and Dissertations

In this study we propose a deep learning method to optimize the classification of wood chip moisture content levels using the Vision Transformer and then ultimately increase the classification performance by creating synthetic images using the diffusion transformer model. In the first chapter of our study, we complete a detailed explanation of how the moisture content levels of 10 different wood chips were gathered ranging from 2 to 50$\%$. This chapter serves as a foundation for subsequent sections, illustrating the challenges associated with the current data collection process, which is both time-consuming and inefficient. Accurately determining moisture content for wood …

“Sometimes The World Don’T Give You What You Need”: Black Motherhood And Kinship As Resistance To Necropolitics In Jesmyn Ward’S Bois Sauvage, Hailey N. Reeder

Theses and Dissertations

This thesis explores how Black motherhood and kinship serve as subversive forces within necropolitical landscapes in Jesmyn Ward’s Where the Line Bleeds, Salvage the Bones, and Sing, Unburied, Sing. Drawing on Achille Mbembe’s theory of necropolitics, this study examines how the economic and social constraints of these environments disrupt Black family structures, emphasizing the necessity of kinship for survival. In Where the Line Bleeds, Cille’s absence disrupts traditional family roles, yet kinship networks allow the family to endure. In Salvage the Bones, Esch’s journey redefines the “bad” Black teen mother stereotype, highlighting how kinship offers support amidst stigma. In Sing, …

Bucket-Based Priority Queues For A* And Related Bounded-Suboptimal And Anytime Search Algorithms: Theoretical And Practical Advancements, Garrett Michael Fereday

Theses and Dissertations

For shortest-path problems with a small number of integer transition costs, it is well-known that the performance of the classic A* algorithm can be improved by using bucketing to reduce priority queue overhead—in particular, by using a bucket queue data structure for the priority queue, instead of a binary heap. This dissertation describes several theoretical and practical extensions of this approach. First, the traditional two-level bucket queue data structure is modified in simple ways to improve the worst-case complexity of its operations, which leads to the first demonstration that the priority queue operations of a two-level bucket queue for A* …

The Influence Of Incorrectly Labelled Ai-Generated Images On Subjective Feelings Of Truth And Memory, Tanner Mckenzie Grubbs

Theses and Dissertations

Artificial intelligence (AI) photo generators generated more than 15 billion images in the past year alone (Valyaeva, 2023). To subdue concerns about misinformation, many online platforms have mandated that content generated with AI be labelled as such (Bond, 2023), but the efficacy of these warning labels is largely unknown. Previous research shows that the presence of an image affects how much we trust the information we are exposed to, so we would expect these AI-generated images to influence people’s beliefs. The purpose of the present research was to examine how AI-generated warning labels influence people’s trust in claims presented with …

Evaluating The Use Of Translucency Score As An Effective Parameter Of Eggshell Quality, Cassidy Autumn Morris

Theses and Dissertations

The objective of this thesis was to determine if an egg’s translucency score (TS) could be used as an effective predicting parameter to determine eggshell quality in both broiler breeders and commercial laying hens. In broiler breeders, it was determined that TS could be used as an effective predicting parameter for eggshell thickness (P< 0.001) and L* scores (P< 0.001). It was also found that the supplementation of organically sourced trace minerals could significantly decrease the TS of eggs, resulting in a better-quality eggshell (P< 0.001). In two different aged commercial laying hen experiments, there was no conclusive evidence for TS to be a predictive parameter of eggshell quality throughout the storage period. It was found, however, that the storage period did significantly increase the TS throughout storage in both experiments (P< 0.001).

Investigations Into Fluorescence Of Fluorene Dimers: Linker Impacts And Tuning Potential Through Substituent Addition, Abigail R. Ressler

Theses and Dissertations

Fluorene-based fluorescing conjugated polymers are being used to develop sensors that show great sensitivity and selectivity, however, important questions about the photophysics of these systems remain unanswered. For example, a fluorescence intensity difference was observed between fluorene dimers linked with either an acetylene (diFA) or phenyl (diFP). The polymers diFA and diFP have similar structures and extinction coefficients, yet diFA yielded a five times higher fluorescence intensity than diFP. In project one, Density Functional Theory (DFT) and Time-Dependent DFT (TD-DFT) were used to calculate the ground and excited states of diFA and diFP. A python code was developed to solve …

Lateral Control Of Autonomous Vehicle Using Deep Cnn And Ampc, Iffat Ara Ebu

Theses and Dissertations

Autonomous functionalities are pivotal for the advancement of Advanced Driver Assistance Systems (ADAS), driving towards collision-free and environmentally sustainable transportation. This thesis presents two distinct studies addressing critical aspects of autonomous vehicle control: lane centering via deep learning and lateral vehicle control using model predictive control. The first study explores end-to-end learning f or autonomous s teering command generation, focusing on lane centering. A convolutional neural network (CNN) model, inspired by NVIDIA’s PilotNet, is employed to directly map raw camera pixel inputs to steering commands, eliminating the need for intermediate feature engineering. The model is trained and validated using datasets …

Empowering Patients With Health Insights: Development And Utilization Of Knowledge Graphs For Comprehensive Patient Medical Journey Mapping And Analytics, Hassan Saadeddine Al Khatib

Theses and Dissertations

Healthcare advancements require advanced solutions to process and understand complex patient data. This dissertation outlines a detailed framework for mapping patient journeys with knowledge graphs (KGs), which begins by analyzing existing Patient-Centric Knowledge Graphs (PCKGs) literature to identify current research gaps in the representation and analysis of patient journeys. Our research proposes solutions to these gaps through three main contributions. First, we introduce the Patient Journey Ontology (PJO), which enables systematic encoding of patient encounters, diagnoses, treatments, and outcomes into a semantic knowledge structure designed for interoperability. The construction of patient journey knowledge graphs (PJKGs) is based on this foundational …

Promoting Collaboration And Multi-Directional Reliance By Sharing Mental Model Information For Effective Multi-Agent Teaming, Audrey L. Aldridge

Theses and Dissertations

Successful human-agent teaming requires teammates to form and maintain a shared or common understanding of several attributes regarding taskwork and teamwork. With enhanced information sharing, mental model development, and team functionality, teammates (human, autonomous) can learn to anticipate each others' behaviors, preferences, and needs as well as understand their capabilities and limitations. In designing a framework to support this type of cooperative teaming, there is a need to determine how sharing knowledge, mental models, and common understandings impacts teaming dynamics and performance. By incorporating each individual's understanding into a human-agent interface, this research enables better team coordination and performance through …

The Effect Of Ultrasound Transducer Type On Diagnosing Medial Meniscal Injury In Dogs With Cranial Cruciate Ligament Injury, Thomas Campbell

Theses and Dissertations

Ultrasonography is reported to be accurate in diagnosing meniscus injuries in dogs but the effect of transducer type has not been studied. The aim was to determine the effect of ultrasound transducer type on utility of meniscal ultrasound. We hypothesized that ultrasonography will provide good diagnostic utility for meniscal injury and that linear transducers will perform best. In this prospective study, the ultrasonographic findings of the medial meniscus using three transducers were compared to arthrotomy findings. Thirty-nine stifles were included with an injury prevalence of 23/39 (59%). The standard linear transducer provided the highest negative predictive value (60%). The small …

The Role Of Institutional Image In First-Generation Student Choice To Attend A Rural Southern Community College, Megan Caves Clark

Theses and Dissertations

As higher education continues to become more competitive with each passing year, research indicates that a favorable image perception of an institution can be achieved through strategic social media presence. With previous literature primarily discussing the impacts of institutional image at a university level, this dissertation explores the role of institutional image in first-generation student choice to attend a rural Southern community college. Using photo elicitation, this qualitative study sought to understand how a rural community college’s social media influences rural, first-generation student’s perception of the college. Results indicated that institutional image perception through social media may play a role …

Adaptive Multi-Sensor Fusion For Robust Autonomous Perception In Unstructured Environments, Samantha S. Carley

Theses and Dissertations

Autonomous vehicles commonly employ multiple sensors to perceive their surroundings. Coupling these sensors would ideally improve perception compared to using a single sensor. An autonomous system can be equipped with object localization and classification, often performed using a visual camera to understand a scene intelligently. Object detection and classification can also be applied to LiDAR and infrared (IR) sensors to further enhance scene awareness of the autonomous system. Herein, sensor-level, decision-level, and feature-level fusion are explored to assess their impact on perception and mitigate sensor disagreements. Specifically, the fusing of RGB, LiDAR, and IR sensor data to improve object classification …

Evaluating The Feeding Value Of Almond Hulls And The Supplementation Of Carbohydrases On Performance, Egg Quality, Nutrient Digestibility And Intestinal Health In Lsl-Lite Hens, Nelly Giovanna Cribillero Chuquihuaccha

Theses and Dissertations

Almond hulls (AH) are a by-product of the almond nut processing rich mainly in insoluble fiber. Addition of fiber in the diet has been shown positive results in performance in poultry. However, scientific literature on the use of AH in poultry is limited. The objective of this dissertation was to determine the effect of the supplementation of ground AH and cellulase-xylanase carbohydrase enzyme (E) inclusions on performance, egg quality, ileal nutrients digestibility, jejunum gene expression and ceca microbiota of Lohmann LSL-Lite pullets and laying hens from 0 to 70 weeks of age. Chapter I describe the knowledge on the composition …

Neural Signatures Of Adhd: A Fast Periodic Visual Stimulation Eeg Study, Haleigh Brielle Davidson

Theses and Dissertations

Fast Periodic Visual Stimulation (FPVS) offers an objective approach for investigating neural responses to emotional stimuli. This study explores the use of FPVS to identify neurophysiological markers associated with Attention Deficit Hyperactivity Disorder (ADHD) by comparing brain responses between ADHD and Non-ADHD participants. EEG data were collected while participants viewed sequences of neutral faces mixed with emotional oddball expressions (Angry, Fear, Happy, and Sad). Frequency-domain analyses were performed to compute Baseline-Corrected Amplitudes (BCA) and Signal-to-Noise Ratios (SNR) across occipitoparietal, occipitotemporal, parietal, and frontal regions of interest. Results revealed significantly reduced BCA and SNR values in ADHD participants, particularly in the …

The Effects Of Ataxin-1 Overexpression In The Central Nervous System On Specific Behavioral And Physiological Characteristics Of Drosophila Melanogaster, Sydney Davis

Theses and Dissertations

Spinocerebellar ataxia type 1 (SCA1) is a dominantly inherited neurodegenerative disease caused by a CAG repeat expansion in the ataxin-1 gene, which results in an abnormally long polyglutamine tract. Similarly, overexpression of wildtype Ataxin-1 (wt-Atx-1) in Drosophila melanogaster leads to neurodegeneration, reduced lifespan, and impaired negative geotaxis. Observations include disruptions in sleep-wake cycles, increased oxidative stress biomarkers (like protein carbonyls), and dysregulation of developmental genes such as armadillo (arm) and nemo kinase (nmo). Additionally, elevated expression of SUMOylation-related genes (Aos-1, Uba2, and dSmt3 or dSumo) and increased SUMO protein levels indicate enhanced SUMOylation in the brain. Quantitative analysis of neuronal …

Real-Time Enhanced Tornado Warning Product Guidance Based On Tornado Debris Signature Height And Population Density, Alexander Cooke

Theses and Dissertations

This research aims to develop an operational program for enhancing real-time tornado warning capabilities by integrating tornado debris signature (TDS) analysis with population impact assessment. The proposed Python-based tool will ingest Level II radar data to identify and analyze TDS, estimating tornado intensity based on maximum TDS height. For high-intensity tornadoes, the program will project the potential impact area using storm motion vectors and integrate this with population density data. The system will assess whether the situation meets National Weather Service criteria for enhanced warning products, providing forecasters with rapid, objective guidance for critical warning decisions. The program’s performance will …

Optimizing Mars Terrain Segmentation With Weakly Supervised Learning: A Focus On Weighted Loss From Annotation Metadata, Malika Dutta

Theses and Dissertations

The study of planetary surfaces heavily depends upon space rovers that gather detailed images of terrain needed for analysis and navigation. Deep neural networks and other sophisticated machine learning techniques are necessary for autonomous navigation in challenging terrain. However, the inconsistent annotations by citizen scientists frequently hinder the performance of these models. This study seeks to optimize terrain segmentation to improve the autonomous capabilities of future Mars rovers by presenting a novel weakly supervised learning framework to handle noise and unreliability in datasets. Using factors like number of clicks, pixel accuracy, and annotator dependability, the method utilizes annotation metadata in …

Influence Of Horizontal Grid Spacing On Numerical Weather Prediction Simulations Of Clear Air Turbulence, Kailah Rose Gordon

Theses and Dissertations

The focus of this research was to analyze the influence of horizontal grid spacing on numerical simulations of kinetic and thermal forced clear air turbulence (CAT) by quantifying uncertainty using a resolution ensemble. Previous studies indicated that microscale (< 1km) spatial resolutions are necessary to resolve turbulent kinetic energy (TKE) with low uncertainty. Six case studies of moderate or greater CAT, from pilot reports, were simulated at six horizontal grid spacings including 1, 2, 4, 8, 16, and 32km using the Weather Research and Forecast (WRF) Model. Results showed that grid spacing does influence the magnitude of uncertainty; however, the relationship between the grid spacings varied with the type of CAT being simulated and the addition of the cumulus parameterization scheme for grid spacings greater than 4km. Overall, higher precision was found between convective resolutions (1-4km), indicating that microscale resolutions are not necessary to precisely simulate TKE for CAT forecasts.

Unraveling Exoplanetary Signatures From Stellar Activity: A Journey Beyond The Known In Rv Mass Measurements Of K Dwarf Planets, Claire Susanne Geneser

Theses and Dissertations

A precise radial velocity (RV) monitoring campaign was conducted for two Targets of Interest (TOI), TOI-2443 b and TOI-139 b, identified by the Transiting Exoplanet Survey Satellite (TESS) as exoplanet candidates orbiting K dwarf stars. Preliminary estimates of the transmission spectroscopy metric (TSM) indicate that the transiting planets are promising targets for atmospheric follow-up. I perform a multi-planet RV analysis of the TOI-2443 system, combining infrared and optical RV data. The model robustly recovers the signal of TOI-2443 b, an eccentric warm sub-Neptune, with a semi-amplitude of 2.54 ± 0.24 m/s, corresponding to a mass of 7.11 ± 0.67 ��⊕ …

Atmospheric Turbulence Education Effects On Flight Anxiety, Megan A. Hanna

Theses and Dissertations

This study examines the effect of turbulence education on flight anxiety. A pre-post methodology measured students’ anxiety levels before and after a study abroad flight, using an educational video during the pre-flight survey to change their feelings. The Flight Anxiety Situations (FAS) questionnaire assessed anxiety at three survey points: pre-video, post-video, and post-flight. Qualitative analysis using Friedman’s test and the Wilcoxon Signed-rank test, indicated that turbulence education effectively decreased generalized and anticipatory flight anxiety, particularly in non-phobic students. Text analysis of open-ended responses suggested increased scientific knowledge post-video helped students apply technical atmospheric processes to their feelings. Turbulence education was …

Exploring Sexual Dimorphism In A Drosophila Melanogaster Model Of Spinocerebellar Ataxia Type 1, Madelyn Hunter

Theses and Dissertations

Neurodegenerative diseases affect over 36 million people and are characterized by loss of motor control, neuronal degradation, and behavioral changes. The most common of these diseases exhibit sexually dimorphic effects. In this study, Spinocerebellar ataxia type 1 (SCA1) was modeled in the Drosophila central nervous system using the yeast hybrid UAS/GAL4 system. Locomotor activity and clock gene expression was monitored for male and female SCA1 and control flies. Clock genes such as per, tim, Clk, and cyc were monitored over a 24-hour period using qRT-PCR, and distinct sexual dimorphism was detected in locomotor activity and in gene expression for SCA1 …

Corn (Zea Mays L.) Productivity, Profitability, And Environmental Sustainability Responses To Nitrogen Application Strategies, Morgan Hutton

Theses and Dissertations

Nitrogen (N) fertilizer is a critical and costly component in mid-southern United States (US) corn (Zea mays L.) production. This study was conducted to determine whether corn productivity, profitability, and environmental sustainability could be manipulated through N application strategies. The effects of N rate, application system, and urea ammonium nitrate (UAN) injection strategies on corn grain yield, N uptake, and runoff N were investigated near Brooksville, MS and Tchula, MS. In 2023 and 2024, N rate nor application system nor trench covering strategies nor UAN injection depth affected corn grain yield. Injecting UAN in two trenches 20 cm from crop …

Semantic Segmentation Via Transfer Learning For Off-Road Data, Haley Breann Honigfort

Theses and Dissertations

In autonomous driving, utilizing deep learning models to help make decisions has become a popular theme, particularly in the realm of computer vision. Deep learning models are heavily influenced to make decisions based on the environments in which they are trained. Currently, very few datasets exist for off-road autonomy that include visual semantic segmentation labels. Traditional semantic segmentation requires hand-labeling large imagery datasets or using synthetically generated imagery to train a model. This study aims to apply transfer learning techniques to automatically label a new off-road dataset. That objective will be accomplished in two phases: first, by utilizing pre-existing labels …

Over And Under Identification Of Emotional Disturbance (Emd) In Minority Students: Implications For Best Practices In Emd Assessment, Danielle Chanell Jackson

Theses and Dissertations

Emotional Disturbance (EmD) remains one of the most inconsistently defined and assessed categories under the Individuals with Disabilities Education Act (IDEA), leading to widespread misidentification that disproportionately affects minority students. This study investigates systemic biases in EmD assessment practices, highlighting how subjective criteria and a heavy reliance on clinical judgment perpetuate disparities in identifying African American and Latino students in special education. To better understand these biases, the study sought to identify which assessment components school psychologists most frequently utilized when making eligibility determinations for EmD. Quantitative analysis revealed that while race was not a statistically significant predictor of EmD …

The Effect Of Dexmedetomidine On The Frequency Of Ureteral Jets Detected In Dogs Using Standard Brightness Mode Ultrasonography, Leonard E. Jordan Ii

Theses and Dissertations

Ultrasonography can be used in dogs to visualize urine entering the urinary bladder (ureteral jets) to determine whether urine enters the bladder normally. Dexmedetomidine is an alpha-2 adrenergic agonist used for chemical restraint and has diuretic properties. The purpose of this study is to evaluate the effect of dexmedetomidine on the number of jets detected using B-mode ultrasonography. We hypothesized: that intravenous administration of dexmedetomidine would cause increased numbers of jets; that jets would increase with increasing doses of dexmedetomidine and length of sedation. Compared to baseline, increases in observed jets occurred at 30- and 40-minutes post 3 mcg/kg (p=0.042 …

Apatite Entrapment Of Iodine For Nuclear Waste Disposal Applications, William E. Laird

Theses and Dissertations

The purpose of this thesis is to provide baseline knowledge of iodine incorporation into calcium phosphate minerals, specifically apatite. Iodine-129 is a fission product in Spent Nuclear Fuel (SNF) that can administer significant amounts of radiation in small quantities. Apatite (Ca10(PO4)6 (OH, F, Cl)) has been studied for the use of radionuclide confinement. Experimental design was set up to mimic temperatures expected in geologic repositories from 40 to 250℃. Experiments are broken into 2 groups based on iodine species being examined. The first group focuses on iodate (IO3-) which is prevalent under oxidized conditions, and the second handles iodide (I-) …

Cyber Security Threat Recognition And Preparedness Of Undergraduate Students, Litany Hope Lineberry

Theses and Dissertations

Cybersecurity awareness and preparedness are critical competencies for individuals across academic disciplines and professional sectors. However, undergraduate students often lack sufficient knowledge and skills to recognize and mitigate cybersecurity threats. This dissertation examines cybersecurity threat recognition and preparedness among undergraduate students through a three-phase research approach. Study 1 explores faculty perspectives on students' cybersecurity awareness, identifying gaps in knowledge and preparedness across various fields of study. Study 2 investigates industry professionals' perceptions of new hires’ cybersecurity readiness, assessing the alignment between academic training and industry expectations. Study 3 evaluates the effectiveness of an online intervention designed to enhance students' cybersecurity …

A Rapid Artificial Neural Network Interatomic Potential For Bismuth, Lee Michael Mayfield Jr.

Theses and Dissertations

To study molecular dynamics in bismuth, Quantum Espresso was used to create a density functional theory (DFT) database which was then used as the input for rapid artificial neural network (RANN). The RANN interatomic potential that was developed using this database was then validated. Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) was used to create simulations and gather data using the RANN potential. The properties of bismuth, including elastic constants, melting points, and volume change, were calculated and compared to DFT and experimentally observed data. The RANN potential coincided well with these values. The RANN potential shows good predictive capabilities for …