Digital Commons Network^™

Efficiency Of Enzyme Induced Carbonate Precipitation (Eicp) By Crude Extract Urease For Geotechnical And Geoenvironmental Applications, Kaniz Roksana

Theses and Dissertations

Geotechnical engineering is currently facing challenges, including accommodating rapid urbanization, adapting to climate change impacts, and prioritizing sustainability, all while ensuring the safety and stability of critical infrastructure. Biocementation is a recently developed new branch in geotechnical engineering that offers innovative and eco-friendly solutions by leveraging natural processes to enhance soil properties. This dissertation examines the potential of soybean extract urease as a cost-effective substitute for analytical-grade enzymes in Enzyme Induced Carbonate Precipitation (EICP) applications for biocementation. This research examines its effectiveness in various aspects, such as coastal erosion control, desiccation crack remediation, and the removal of heavy metals. Essential …

Lgbtq+ Identity Development And Individual Vs Group Psychotherapy Experience: A Consensual Qualitative Analysis, Aileen Marie Rands

Theses and Dissertations

Multicultural topics, such as LGBTQ+ experience, have accrued predominance within the field of psychology. It has become clear that better understanding minority experience is of utmost importance. Pervasive stigma, discrimination, and mistreatment culminate into minority stress; thus LGBTQ+ individuals face greater risk for poor mental health and seek out psychotherapy at higher rates. Despite this reality, limited psychotherapy research exists in this area generally and essentially no research has looking into the experience of LGBTQ+ individuals in group therapy. The current study investigated experiences of LGBTQ+ clients who have participated in both individual and group psychotherapy. Eleven participants were interviewed …

Mind Matters: Investigating The Impact Of Mental Health First Aid Training On High School Staff, Sarah Jo O'Neill

Theses and Dissertations

This dissertation, titled Mind Matters: Investigating the Impact of Mental Health First Aid Training on High School Staff, examines whether Mental Health First Aid (MHFA) training equips high school personnel with the necessary tools to identify and support students in crisis. Conducted over six weeks during a series of Kitchen Table Conversations, the study involved eight high school staff members who participated in a structured MHFA training program. Qualitative data collected from participant discussions revealed that while the current MHFA training format is a good start, it lacks school-specific contextualization. More importantly, the opportunity to discuss and process the material …

Event-Based Camera Simulation And Neural Network Processing For Autonomous Aerial Refueling, Stephanie C. Hanson

Theses and Dissertations

Event-based cameras excel in dynamic environments, and do not face challenges like washout and motion blur, like a frame-based camera. This work describes the process used to collect the first EBS data collect for use in AAR, and develops an event simulator to generate synthetic training data for evaluating CNN architectures on asynchronous data. The three models compared are a traditional CNN, a YOLO-based CNN, and an asynchronous sparse CNN. The YOLO-based model achieved the best accuracy, while the sparse CNN, despite being less optimized, maintained an average IoU of 0.9. These results highlight the potential of asynchronous approaches for …

Hyperparameter Tuning For Robust Autonomous Vehicle Vision, Nico D. De Ros

Theses and Dissertations

Classification “flickering,” where the classification of an object changes inconsistently between consecutive video frames, remains a persistent issue in modern object classification algorithms. This problem undermines the reliability of autonomous vision systems and poses significant risks in high-stakes applications such as autonomous vehicles. This thesis explores the use of response surface methodology, a statistical design of experiments technique, to optimize hyperparameters across three object classification pipelines. The first pipeline combines YOLOv8 with SORT to establish a benchmark. The second integrates a Bayesian back-end, while the third employs an exponential smoothing back-end. Hyperparameter tuning was conducted using a two-step process: an …

Island Nation Duress: Simulating Passive Peer-To-Peer Bluetooth Communication During Disaster Relief, Jason K. Medeiros

Theses and Dissertations

Pacific Islands under U.S. jurisdiction are highly vulnerable to natural disasters, yet many lack the infrastructure to effectively respond and recover. Clear communication during and after such events is critical for evacuation, hazard awareness, and first responders’ coordination. This research explores a simulation-based approach using Bluetooth communication to relay messages across Guam, assessing its efficiency through statistical analysis. By examining regional differences and geographic impacts on Bluetooth messaging, the study aims to identify key factors that enhance peer-to-peer communication for timely and effective disaster response.

Class Imbalance: A Landscape Of Classification Models, Joshua L. Edmonds

Theses and Dissertations

Class imbalance poses significant challenges in machine learning classification. This study evaluates the performance of seven models (ANN, k-Means, kNN, LDA, LR, SVM, XGBoost) across multiple imbalance levels (10\%, 5\%, 1 \%, 0.5\%) and investigates the effectiveness of sampling techniques (Undersampling, SMOTE, SMOTE-ENN). ANOVA results confirm that model choice is the most critical factor, with XGBoost and SVM demonstrating superior robustness. SMOTE improves recall but reduces precision, while undersampling generally degrades overall performance. While significant, imbalance levels do not play a critical role in model effectiveness.

Retrospective Cohort Study Of Pure Tone Audiometry Hearing Changes Associated With Ototoxic Metals And Solvents, Continuous Noise And Impulse Noise Exposures At Robins Air Force Base From 2001-2019, Ronald Diaz Cataldo Ramos

Theses and Dissertations

Utilizing DOEHRS-IH and DOEHRS-HC, a retrospective epidemiological study was performed on Robins AFB personnel to investigate relative risks of hearing loss associated with exposures to continuous noise, impulse noise, and ototoxic metals and solvents. An analysis of variance identified age, frequency octave, era and exposure type as influencers of hearing threshold shifts. Risk ratios showed higher risk of hearing loss for exposures to continuous noise + impulse noise + ototoxic metals as well as continuous noise + impulse noise at low frequencies (500Hz and 1,000Hz), and lesser risk for exposures to continuous noise + impulse noise and continuous noise + …

Assessing The Feasibility Of Managed Aquifer Recharge For The United States Air Force, Daniel Hendrix

Theses and Dissertations

Water stress is becoming an increasing global issue, with 4 billion people (50% of the world’s population) experiencing water stress at least one month per year. By 2050, 60% of the world’s population and $70 trillion USD in global gross domestic product will be affected. This research analyzes 78 CONUS USAF installations to determine location-specific water stress and feasible Managed Aquifer Recharge (MAR) solutions. Although thousands of MAR projects have been implemented globally, active-duty USAF installations have yet to contribute to solving this growing issue. Important factors such as required subsurface conditions, physical limitations, design, cost, and regulatory constraints are …

Air-Based Chemical Patient Decontamination Methodologies For Arctic Regions Using Methly Salicylate As A Chemical Agent Surrogate On A Litter-Bound Manikin, Marcus D. Shadd

Theses and Dissertations

This study evaluated a mobile air shower for patient decontamination without disrobing or rinsing, an alternative for Arctic conditions where water is scarce. A manikin in extreme cold weather gear was exposed to 10 µL of methyl salicylate (MeS), a sulfur mustard surrogate, and placed in a horizontal chamber on a military litter. Airborne MeS was measured using a ppbRAE 3000 detector to assess inhalation risk for the patient and decontamination team. Three methods were tested: an air-knife system, paper towels, and no decontamination, with 10 trials each (30 total). ANOVA analysis showed significant reductions in airborne MeS with air-knife …

Radiation Assessment And Distribution In Changing Atmospheric Structures And Turbulence (Radcast), Steven B. Hernandez

Theses and Dissertations

The accessibility of materials and online information has made radiological dispersal devices (RDDs) a more probable threat than conventional nuclear weapons. This study analyzed five datasets from three test periods, using a correlation analysis between optical turbulence, aerosol concentration, and environmental parameters, and geometric mean diameter (GMD) calculations. The correlation analysis failed to yield meaningful insights, prompted a transition to the GMD analysis, which produced clearer results. Findings show GMD ranged from 38–41 nm, increasing at night and during neutral events as reduced vertical motion and boundary layer contraction correlated with optical turbulence. An alternative GMD dataset, calculated by the …

Transfer Efficiencies Of Surface-To-Surface Transport Of Micron-Sized Actinide Surrogate Particles, Austin R. Powell

Theses and Dissertations

Particle effluent of varying sizes is released during routine activities within laboratory environments and these particles can come in contact with a wide range of surfaces. Particles of micron size or smaller can be especially pervasive and can transfer between multiple subsequent surfaces, leading to the progressive contamination of a laboratory. Understanding the transport dynamics of micron sized particles will help inform facility personnel of the possibility of contamination by these potentially hazardous materials of interest. In this research, the transfer efficiency of micron sized surrogate actinide particles (Europium-doped Gadolinium Oxysulfide (EGOS)) is measured for multiple materials, between two particle …

Evaluating Dry Air Personnel Decontamination Of Methyl Salicylate As A Chemical Agent Surrogate In Extreme Cold Environments To Reduce Airborne Risks Using A Manikin, Lance E. Campbell

Theses and Dissertations

This research investigated a mobile air shower as an alternative to water washing for personnel chemical decontamination in Arctic environments, where traditional methods like disrobing and rinsing are impractical. Interest in Arctic operations has grown with recent U.S. military focus on strategic advancements by Russia and China, yet research on air shower effectiveness for chemical decontamination remains limited. This study examined whether a commercial off-the-shelf air shower could effectively decontaminate methyl salicylate (MES), a surrogate for chemical warfare blister agents, from a manikin outfitted in military cold-weather gear. Researchers used a ppbRAE 3000 photo-ionization detector to measure MES concentrations following …

Molecular Scale Investigations Of Interactions Between Pfas And Concrete, Eric E. Keeler

Theses and Dissertations

Per- and polyfluoroalkyl substances (PFAS), widely referred to as “forever chemicals,” exhibit high environmental persistence and potential health risks due to their robust carbon-fluorine bonds. These substances are prevalent in aqueous film-forming foams (AFFF), used in industrial and military applications, and are known to contaminate environmental surfaces, including concrete. This study aims to characterize the molecular-level interaction energies of six PFAS species—PFOA, PFOS, PFHxS, PFHxA, 6:2 FTS, and PFBS—with calcium silicate, a key component of concrete, using density functional theory (DFT) calculations. Change in Gibbs free energy (ΔG) was determined for each of the interactions, revealing negative ΔG values for …

Improving Zero Shot Learning By Linking Multi-Label Cnns With Llms, Michael A. Wegner

Theses and Dissertations

Classifying previously unseen objects poses a significant challenge for traditional computer vision algorithms, which rely on extensive labeled training data. Zero-shot reasoning offers a way to overcome this limitation. This research explores a novel method for image recognition using the Animals with Attributes 2 (AWA2) dataset as a proof of concept. A multi-label ResNet50 model predicts core attributes like color, ear shape, or number of limbs. Those attributes then feed into ChatGPT which leverages its extensive knowledge base to classify the animal based on the provided attributes. This novel approach skips the need to train on every possible class. Instead, …

Discovering Design Requirements For Next Generation Arctic Tension Fabric Shelters, Mark W. Mcveigh

Theses and Dissertations

Military operations to remote Arctic regions require large-span temporary shelters to house tactical aircraft and provide heated maintained spaces. However, the current System-50 Large Area Maintenance Shelters used by the United States Air Force and Department of Defense are inadequate for Arctic deployments. These shelters lack durability against extreme subzero temperatures, heavy snow accumulation, and high wind speeds. They also fail to address critical Arctic-specific design challenges including permafrost protection, foundation disruption caused by frost heaves, and efficient heating as a result of their inadequate thermal resistance properties. This research analyzed 20 years of climatological data from 8,399 weather observation …

Atmospheric Water Generation: Bacterial And Inorganic Chemical Quality, Garrett E. Stanley

Theses and Dissertations

This study investigated the quality of untreated water collected from a vapor compression-based atmospheric water generator (AWG) operated outdoors in Dayton, Ohio. The concentrations of bacterial and chemical constituents were determined. The concentration of culturable bacteria was between 200 and 2300 CFU/mL, significantly higher than the reference levels described in recreational and drinking water quality guidance. Three discrete bacteria phenotypes were visually identified; two were yellow in color, rod-shaped and gram-negative while the third was milky white, circular, and gram-positive. Chemical analysis on 15 randomly selected samples revealed the presence of Barium (average = 0.16 mg/L), Magnesium (0.08 = mg/L), …

Early-Phase Cost Estimation For Department Of Defense Construction Projects Via Artificial Neural Networks: Implications And Policy Recommendations For Artificial Intelligence Integration, Kobe T. Thompson

Theses and Dissertations

The Department of Defense lost over 500 million dollars between 2016 and 2024, partially due to poor early cost estimates resulting in cost overruns. practice for cost estimation relied on parametric techniques that incorporate historical data, subject matter experts in cost estimating, and predictive software applications. The main motivation for this study was to assess the viability of artificial neural networks as a means of providing a more accurate cost estimate in the early design phases of a construction project. The dataset initially contained approximately 48,000 data points from a database of various Air Force projects, including maintenance, repair, minor …

Material Classification With Spectropolarimetric Lidar, Alexander J. Watson

Theses and Dissertations

A method for characterizing unknown targets using a hyperspectral polarimetric light detection and ranging (LiDAR) system is presented. Light reflected from manmade objects tends to be more polarized than light reflected from objects in the natural world. As such, polarization measurements can be used in remote sensing applications to differentiate artificial and natural objects. Previous works have attempted to characterize objects through passive polarimetric imagery. Methods developed by Cain and Lemaster and Cunningham facilitate reconstruction of the Stokes Vector from returning light. Martin used multispectral polarimetry to classify targets when the angle of incidence (AOI) is close to 0º. Here, …

Approximating Three-Body Trajectories With A Knot Theory Inspired Model For Orbit Generation And Determination, Mason R. Mill

Theses and Dissertations

This thesis explores a novel approach to approximating three-body trajectories using a knot theory-inspired model for orbit generation and determination. Traditional methods for solving the Circular Restricted Three-Body Problem (CR3BP) rely on numerical integration and correction schemes to generate trajectories, often requiring iterative refinements. This research investigates the application of knot theory principles—such as torus knots, Alexander polynomials, and Reidemeister moves—to categorize and model complex orbital trajectories in the CR3BP. By leveraging these mathematical tools, the study aims to enhance trajectory prediction, orbit determination, and mission planning for spacecraft operating in the cislunar environment. The results demonstrate that knot theory …

Personal Decontamination Of Copper Oxide Powder As A Radiological Surrogate On Ambulatory Patients In Arctic Environments: Assessing Residual Airborne Risks After Air Shower Or Vacuum Decontamination Of A Manikin, Quinn G. Pelichoff

Theses and Dissertations

This study assessed air-based decontamination methods for treating patients exposed to dry radiological contamination while minimizing reaerosolization during disrobing, particularly in extreme cold environments. A full-size manikin,  simulating an able-bodied Airman, was dressed in military-issue extreme cold weather gear and coated with 28 grams of Copper Oxide. The manikin underwent one of three treatments: HEPA vacuuming, a mobile personal air shower, or no treatment (control). After treatment, researchers removed the uniform and used optical particle counters to measure airborne dust concentrations that could pose risks during disrobing. Each method was tested ten times (30 trials total). Statistical analyses (ANOVA, Tukey’s …

A Randomized Controlled Study Of Heart Rate Variability Biofeedback In An Older Adult Sample, Whitney D. Allen

Theses and Dissertations

Heart rate variability biofeedback (HRVB) is a controlled breathing treatment designed to increase the variation in consecutive heartbeats leading to improved regulation of one's autonomic nervous system thereby improving one's ability to self-regulate and maintain homeostasis. Changes in heart rate variability (HRV) are seen in those of increased age and lower HRV is associated with poorer outcomes (e.g., increased mortality, worse emotional functioning, cardiovascular risk factors). As such, older adults are a group that stands to benefit from HRVB principles. The current randomized control trial was designed to understand the impact of HRVB in an older adult population on resting …

Molecular Mechanisms Of Niemann-Pick Type C: Investigating Gene Expression, Lipid Metabolism, And Mitochondrial Dysfunction In Fibroblasts, Sarah Kim

Theses and Dissertations

Niemann-Pick Disease Type C (NPC) is a progressive lysosomal storage disorder characterized by the accumulation of lipids, particularly cholesterol, within cells, leading to severe neurological manifestations and developmental issues. This study employs RNA-seq to compare gene expression profiles between fibroblasts derived from a healthy individual and a patient with the NPC1 mutation. A total of 12,978 genes were analyzed, revealing 191 differentially expressed genes. Functional enrichment analysis disclosed significant associations with biological processes related to development, lipid metabolism, embryonic organ development, vascularization, and neuroinflammation. Additionally, the connection between mitochondrial function and lysosomal impairment was explored, revealing that NPC1 mutant fibroblasts …

Mir-125a-3p And Its Targets: Promising Biomarkers For Ovarian, Liver, And Breast Cancers, Offering A Beacon Of Hope For More Effective Diagnosis And Treatment Strategies, Eman Kamaleldien Anwer

Theses and Dissertations

Cancer is a worldwide health problem with various genetic and epigenetic alterations, resulting in disease heterogeneity. Effective diagnostic, therapeutic, and monitoring markers have been determined recently; however, new diagnostic, prognostic, and therapeutic markers are needed. MicroRNAs (miRNA), short non-coding RNAs, have a highlighted role in cancer progression, migration, and programmed cell death. Our study aims to investigate the significance of miR-125a-3p and its downstream targets in breast (BRCA), hepatocellular (HCC), and ovarian (OVCA) malignancies and their possibility as diagnostic biomarkers and targets for therapeutic agents. Bioinformatics and online tools were used to determine the miRNA-predicted downstream targets, analyze GEO datasets, …

1 Studying The Determinants Of Successful Aging: Diet, Lifestyle, And Social Relations In Egypt, Fayrouz Shaltout

Theses and Dissertations

Abstract

Background

The global population is aging rapidly, with projections indicating that by 2050, one in six people will be over the age of 65. In Egypt, the aging population, particularly those aged 60 and above, is expected to grow significantly, posing a growing public health concern. Unhealthful diets (that are associated with overweight and obesity), are one of the main reasons associated with non-communicable diseases (e.g., diabetes and cardiovascular diseases) are major risk factors for poor aging outcomes. Despite this, there is limited research on the specific determinants of successful aging (SA) in Egypt, especially among individuals aged 50 …

The Metaphysics Of Time Within Physics, Mohamed Ahmed

Theses and Dissertations

The starting point of this thesis is to shed some light on the metaphysical nature of time by reflecting on the physics of time. The aim of this approach is not to [dis]prove or defend a metaphysical position but rather to elucidate the metaphysical position that underlies [or is compatible with] our best scientific theories. This task will be demanding, not only because our best theories may carry different interpretations of their underlying temporal structure but also because there seems to be a conceptual conflict/incompatibility between the notion of time in relativity and quantum mechanics, which are the two major …

The Role Of Non-Coding Rnas As An Innovative Therapeutic Tool For Hepatocellular Carcinoma, Nabila Mohamed Hosni El Kramani

Theses and Dissertations

Hepatocellular carcinoma (HCC) is the second lethal cancer worldwide, with over 60 million new patients added annually. Hepatitis B infection and toxins, e.g., aflatoxin, contribute to the incidence of HCC. Egypt and China show the highest prevalence of viral hepatitis and HCC in the world.

Long non-coding RNAs (lncRNAs) are non-protein-coding transcripts larger than 200 nucleotides. These transcripts work at the transcriptional, post-transcriptional, and epigenetic levels to regulate gene expression by interacting with various biomolecules, such as RNA, DNA, and proteins. They serve essential functions in chromatin remodeling and cell survival, differentiation, and proliferation. The role and biological interactions of …

Predicting The Indirect Cost Of Construction Projects In Egypt: An Artificial Neural Network Approach, Aya Effat

Theses and Dissertations

Cost estimation is one of the vital processes in construction management that needs to be done early in any project in order to determine the project's budget. The accuracy of the cost estimate is a key factor in the success of construction projects since it enables project managers to successfully control the project’s expenses. Construction costs mainly consist of direct cost and indirect cost. Generally, indirect costs can be categorized into two types: site overheads and general overheads. In a construction project, overheads, particularly site overhead costs, make up a considerable portion of a contractor's budget. Accordingly, accurately estimating the …

Identification Of Novel Genetic Biomarkers Linked To The Prodromal Stage Of Parkinson’S Disease (Pd) Patients, Marwa Tawfik Badawy

Theses and Dissertations

Background and Objective: The early diagnosis of neurodegenerative diseases, such as Parkinson's disease (PD), is particularly challenging because symptoms appear only after significant neuronal damage has already occurred. This study is utilizing variant call format (VCF) analysis to identify genetic variants and novel genes that could serve as early prognostic markers for prodromal PD. Materials and Methods: Data were sourced from the Parkinson's Progression Markers Initiative (PPMI), focusing on prodromal patients with gVCF data from the 2021 cohort. The study included 304 participants, comprising 100 healthy controls, 146 individuals with prodromal genetic indicators, 21 individuals with prodromal hyposmia, and 37 …

Integrating Planetary Health Into Public Health Education For Sustainable Healthcare Practices, Eman Aboualy

Theses and Dissertations

Introduction: Integrating planetary health in public health education became an urgent global call for action since the WHO announced that the climate change and environmental degradation are the most threat facing the humanity in the recent decades (1). According to that, many countries are developing strategies for counteracting and mitigating the impact of climate change and restore the planetary health. These strategies are including policy drafting and preparing their public health professionals to recognize and address the health effects of environmental change, promote practices for sustainable healthcare. Although Egypt is formulating different policies to cope with and respond to the …