Digital Commons Network^™

Performance Of Multi-Composite Materials With Corrugated And Cell Geometries Under Low-Velocity Impact, Lukas S. Kolbl

Master's Theses

Composite structures have demonstrated great potential to improve mechanical performance in various applications, including ballistics protection. This study demonstrates that the integration of geometrically optimized composites into core-face sheet assemblies provide great impact resistance. The research investigated the performance of two composite manufacturing methods under low-velocity impact through residual strength and damage comparisons. Corrugated core composites were produced with traditional manufacturing methods, namely compression molding, using twelve stacking sequences. These stacking sequences were chosen to represent four laminate groups, where a unique fiber orientation scheme was employed across three laminate thicknesses (6, 8, and 12 layers). In contrast, honeycomb and …

Finite Element Analysis And Verification Of Transverse Mechanical Properties Of Generally Cylindrical Orthotropic Constitutive Modeling Of 3-Phase Nanocomposite Unit Cell, Christopher J. Hawkins

Master's Theses

Fiber-reinforced composites are increasingly popular due to their specific strength and stiffness, making them ideal for high-performance applications. However, these materials primarily exhibit superior properties in-plane, while their out-of-plane characteristics remain comparatively weaker. Previous research has shown that the most effective method to enhance out-of-plane properties involves the incorporation of carbon nanotubes. Experimental tests have demonstrated significant improvements in properties such as tension, flexural, short beam shear, and fracture toughness. Alongside these experimental studies, analytical equations have been developed to predict the behavior of these composites under various loading conditions, including tension, bending, shear, and fracture. Existing models primarily address …

Bonsai Merkle Tree Streams: Bulk Memory Verification Unit For Trusted Program Verification System, Richard J. Rios

Master's Theses

Today, all modern computing systems are undoubtedly vulnerable to numerous types of attacks that could be targeted toward any layer of the system from dedicated hardware to highly abstracted software. Unfortunately, many devices and systems naturally contain inadequately protected components or software modules that un- dermine their security as a whole. Additionally, security is heavily variable system to system, and has a huge dependence on adequate implementation and ongoing support from device and software manufacturers. To address these various security issues in a very general way, TrustGuard, a containment security system utilizing an external device called the Sentry that would …

Photophoretic Optical Particle Trapping Improvements Using Beam Reflection, Ian A. Garcia, Xiaomin Jin Phd., Kun Hua Phd.

Master's Theses

Current research has shown that photophoretic optical trapping (POT) is a promising method for creating true three-dimensional holograms. A landmark study by Smalley et. al. at BYU was able to generate a full hologram within a 2 cm edge cube with remarkable success. However, a key drawback to this method is its poor ability to hold trapped particles within the focal point of the laser for an extended period of time. An investigation from our group presented at SPIE Photonics West 2023 sought to improve these results by varying the focal length of the trapping and the wavelength of the …

Joseph Moxon: Fueled By Science, Extinguished By Class. How A Forgotten Middle-Classed Early Modern English Puritan Printer Mathematician And Globe-Maker Helped Forge The Scientific Revolution And Democratize Knowledge Among The Trades, Kenneth L. Macro Jr.

Master's Theses

Joseph Moxon, raised within the trades, elevated into the middle-class, was an inducted Fellow of the Royal Society, Hydrographer to the King’s Most Excellent Majesty, Printer, Author, Translator, Maker of Globes and of Spheres, Maker of Maps and of Mathematical Instruments, Engraver, and Entrepreneur. Moxon was the quintessential Renaissance Man. A tradesman living in a time of great scientific intrigue and discovery, Moxon, acknowledged by few mid-seventeenth century historians, rightfully contributed his scientific discoveries—in the forms of tutorials and manuals written for the common man—as a testimony to all printers who have helped in the progression of the Scientific Revolution. …

Ultrasound Denoising And Speckle Reduction Using Artificial Neural Networks, Mark Atttaalla

Master's Theses

This paper focuses on improving speckle reduction and denoising performance in ultrasound images by leveraging neural networks. A dataset of simulated ultrasound images was created using Field-II simulation software based on CT scan images, to create clean and noisy image pairs. Various Convolutional Neural Network models based on U-Net and generative adversarial networks were developed and tested. Peak Signal-to-Noise-Ratio (PSNR) and Structural Similarity Index Measurement (SSIM) were used as metrics along with qualitative assessment. Results show that our tuned U-Net generator network outperformed traditional filtering such as Lee and BM3D.

Policies And Price Controls On The Research And Development Of Orphan Drugs In The United States And The European Union, Bena Pearl Filipczak Smith

Master's Theses

There is substantive literature surrounding the impact of price controls on the research and development (R&D) of new pharmaceutical products. The European Union (EU) and United States (US) are often studied in contrast to examine the influence of price controls as the US has fewer pharmaceutical price controls than the EU.

We find moderate evidence that the US spent more on annual domestic pharmaceutical R&D than the EU between 2004 and 2021, on average, before and after adjusting for GDP growth per capita and year. We find strong evidence that the US increased annual domestic R&D spending at a faster …

Dynamic Knowledge Elicitation: Leveraging Student Feedback For Improved Language Model Distillation, Reuven Muller

Master's Theses

Large Language Models (LLMs) have significantly advanced the field of natural language processing but remain resource-intensive and impractical for many organizations. Specialist models offer a viable alternative, often developed through Knowledge Distillation (KD) techniques. However, traditional KD methods rely on predefined static datasets to elicit knowledge from the teacher model, failing to dynamically address the weaknesses of the student model during training. This research introduces two novel methods for adaptive knowledge elicitation: Feedback-Driven Question Generation and Agent-Based Targeted Question Generation. These methods iteratively expand the training dataset based on the student model’s performance, leveraging a teacher model to generate targeted …

Machine Learning-Driven Process Analysis And Optimization In Solid-State Welding And Fusion-Based Additive Manufacturing, Radif Uddin Ahmed

Master's Theses

In the modern era of advanced manufacturing, optimizing process parameters is pivotal in ensuring the quality and reliability of sophisticated component fabrication. This study presents a novel, data-driven approach to parameter optimization in two cutting-edge manufacturing techniques: Friction Stir Welding (FSW) and Laser Powder Bed Fusion (LPBF). By leveraging machine learning methodologies, this research addresses the critical challenge of efficiently determining optimal process parameters, a task traditionally relying on time-consuming and resource-intensive trial-and-error methods. This study will lead to a robust data-driven framework for process analysis of more advanced manufacturing techniques like the Additive Friction Stir Deposition (AFSD) process. Friction …

Active Tectonics, Erosion Rates, And Topographic Metrics In The Hayword-Calaveras Fault Zone, Simone I. Yeager

Master's Theses

In northern California, the complex geometry of the San Andreas Fault system, and how it steps and propagates across the Earth’s surface, is revealed in the topography. Activity along the Mission and Arroyo Aguague oblique reverse faults, located where the right-lateral Hayward Fault steps to the left of the Calaveras Fault, are manifested in the Diablo Mountain Range. The high topography in the restraining step can be observed in lidar imagery and seismicity studies show these faults are connected at depth. In this study, we investigate active tectonics, erosion rates, and topographic metrics from the southern end of the restraining …

Exploring Community Adaptation To Public Safety Power Shutoff Events: Findings From Two Case Studies Of Unincorporated Mountain Communities In Southern California, Ramiro M. Brown

Master's Theses

As aging electrical infrastructure in the US continues to succumb to unyielding weather patterns brought on by climate change, there is an urgency among Investor-Owned Utilities (IOUs) to reduce the likelihood of their equipment sparking a wildfire. Public Safety Power Shutoffs (PSPS) – the intentional de-energization of the electrical grid on high fire weather danger days – have become a staple in IOU Wildfire Mitigation Plans (WMPs) since 2018 as one way to avoid wildfire ignitions via electrical infrastructure. One criticism of PSPS events is that they create their own hazard by cutting off power to thousands – sometimes millions-of …

Relationship Between Depression, Rumination, And Emotionally Valenced Working Memory Performance, Dewey Tran

Master's Theses

Working memory is limited in capacity and easily disrupted such that mood states and competing cognitive processes can impair performance. Rumination is highly associated with depression that may contribute to impaired working memory but has not often been studied. The goal of this study was to elucidate the relationship between depression severity, ruminative state, and working memory performance. Participants completed a baseline assessment of depression severity, rumination (trait and state), and working memory then randomly assigned to a rumination or control groups, followed by a second assessment. I hypothesized working memory would be explained by an interaction between depression severity …

The Effects Of Stress On Attentional Networks, Alice Tsvinev

Master's Theses

The human brain has developed mechanisms to aid our survival, including attentional networks and stress response. Attentional shifts allow humans to react accordingly to their environment, following innate processes like fight or flight. Prolonged exposure to acute stress interferes with such cognitive processes as attention and working memory, impacting attentional systems. The present study examined the effects of acute stress on visual attention processes, specifically focusing on the orienting, alerting, and executive attention networks. 49 participants were randomly placed in either a stress or non-stress condition, then asked to reflect on either stressful or positive moments in their lives, respectively. …

A Novel Reinforcement Learning Method For Efficient Cross-Training Between Real And Simulated Robots, Zhonglin Liang

Master's Theses

Training reinforcement learning policy in a simulated environment can be a go-to choice for many research topics, as a simulated environment provides flexibility and costs less than building a physical environment for training. However, policy trained in a simulated environment often fails to transfer to the real environment for problems that have a more complex dynamics. As the solution, Sim2Real was proposed and it categorizes techniques that improve the performance of the transfer from simulation to reality. Sim2Real is an area of study that focuses on utilizing simulation data to train models that can apply to real world environment. It …

Swim Bladder Morphology Influences The Responses Of Nearshore Rockfishes To Barotrauma, Molly K. Alvino

Master's Theses

Rockfishes (Sebastes spp.) are ecologically and economically important fishes in the continental shelf and slope regions of the Eastern Pacific Ocean. All species within the Sebastes genus have a buoyancy organ, the swim bladder, which is sensitive to rapid changes in pressure that occur when fish are caught and brought up to the surface. Although all rockfishes have swim bladders, pressure-related injuries (barotrauma) affect rockfish species differently. I determined whether swim bladder morphology can explain differences in barotrauma among semi-pelagic (Blue and Olive rockfish) and benthic (Gopher and Vermilion rockfish) species that occupy different habitat zones. Seven different swim bladder …

Creatine And Depression In Rodents: A Meta-Analysis, Ruchika S. Tirupachur

Master's Theses

Traditional treatments for major depression are based on the monoamine deficiency hypothesis, and they fail to achieve remission in a substantial portion of patients. Newer evidence suggests the pathophysiology of depression is a more complex story, highlighting a need for research in alternative therapies. Mounting evidence shows a linkage between depression and the supplement creatine monohydrate (CRMH). Research in rodent models suggests that CRMH may both alleviate depressive symptoms and enhance the efficacy of standard antidepressants like SSRIs. The following study describes findings from a combined fixed- and random-effects meta-analysis based on four empirical studies investigating the effect of CRMH …

The Impact Of Adverse Childhood Experiences On Later Desistance Among Serious Juvenile Offenders From A Broken Family Composition, Olivia Franklin

Master's Theses

The current study aimed to contribute to the overall knowledge of desistance patterns among juveniles by exploring them among serious juvenile offenders who come from a broken home. Utilizing the Pathways to Desistance (PTD) dataset, this study used logistic regression to examine the impact of family composition on later desistance while controlling for various adverse childhood experiences (ACEs) one might experience. Two research questions guide this study: (1) Does family composition (i.e., “broken homes”) impact later desistance among serious adolescent offenders, while controlling for important criminological predictors (i.e., self-control and antisocial peer influence)? (2) Is the quality of one’s home …

Using Noninvasive Calibrated Cuff Plethysmography To Observe The Effects Of Diabetes On Arterial Compliance, Jadon Bradford

Master's Theses

The prevalence of cardiovascular disease is on a continuous exponential growth across the globe. Thus, research into the underlying factors, effective methods of diagnoses, and preventive measures is necessary. Endothelial dysfunction is an early detector of cardiovascular diseases and can be used to inform people of preventative measures and early treatments before any extreme medical conditions occur. Something that is also on the rise and closely linked with cardiovascular disease is diabetes. There have been many past research studies that show the impact of diabetes on cardiovascular disease and more specifically endothelial dysfunction. A calibrated cuff plethysmography device is a …

Hypoxic Incubator: Improving Robustness/Reliability And Demonstrating Physiological Efficacy, Damon Dennis Tan

Master's Theses

The Microphysiological Systems Laboratory aims to develop colorectal cancer tumor models under a hypoxic environment to assess model response to pharmaceutical compounds in vitro. To perform relevant studies, researchers have attempted to use different hypoxic inducing strategies such as a nitrogen pod and hypoxic incubator to recreate in vivo physiological responses to hypoxia. However, studies would be interrupted due to incubator functionality failure. To ensure successful and physiologically relevant studies, I improved and verified the robustness and reliability of a hypoxic incubator previously designed and manufactured in the lab. Through the testing and iterating design processes, I engineered and implemented …

Implications Of Persistent Micro-Bioplastics On Biogeochemical Properties Across Soil Types, Casandra R. Leach

Master's Theses

Terrestrial microplastics are increasing in abundance and are an emerging contaminant of concern, particularly in agriculture ecosystems where plastic use and subsequent soil contamination are prevalent. Plastic film mulches make up a significant portion of the plasticulture industry and are directly linked to soil microplastic pollution where negative effects to soil biotic and abiotic functions have been observed. In response to this issue, biodegradable film mulches have been promoted as a sustainable alternative to conventional polyethylene-based mulches. These biodegradable mulches, composed of various bioplastics, are designed to be tilled back into the soil where they are expected to decompose. However, …

Hardware Control Unit For Trusted Program Verification System, Jake Owen Alt

Master's Theses

Trust in the underlying hardware is the foundational step towards trusting the correctness and integrity of a software application. However, verifying that today's extremely complex processors work exactly as intended has not been feasible, as evidenced by several recent hardware bugs. Trustworthy, formally verified processors currently forego intricate performance enhancements such as out-of-order execution, hampering them substantially versus their less secure counterparts.

The Containment Architecture with Verified Output (CAVO) system solves this problem by isolating the host system and requiring the result of each instruction to be validated by a small, trusted hardware module called the Sentry. Any transmissions to …

Drivers Of Microparticles Abundance In Freshwater Fish And Macroinvertibrates, Elizabeth Kazmierczak

Master's Theses

Anthropogenic microparticles (MP) (i.e., particles < 5 mm) are defined as materials of manufactured origin found in the environment. They are widespread and a rapidly emerging global contaminant. MP include microplastics (< 5 mm), as well as other microfibers or particles, which can be synthetic, semi-synthetic and non-synthetic. Rivers are a critical source of plastics to oceans, and MP within rivers are retained in part though biological processes, including ingestion. MP ingestion by freshwater biota varies by proximity to point sources (e.g., wastewater treatment plants; WWTP), overall environmental concentrations, and trophic level and functional feeding groups, but few studies have examined these factors together. In our first study we examined fish collected in the North Shore Channel of the Chicago River to determine MP abundance within organisms. We then compared trophic position (i.e., δ15N) and proximity to a WWTP. With all species combined, MP concentration were not significantly different across study sites, but stable isotopes increased downstream. Considered individually, MP abundance relative to WWTP proximity varied by species, which we attributed to habitat preference and mobility. In a second project, we collected macroinvertebrates from three different watersheds in North America and compared the abundance of MP in macroinvertebrates to concentration within the environment (i.e., water column, surface, and benthic). Functional feeding groups were a significant predictor in the amount of microparticles found in macroinvertebrates. Additionally, the concentration of water column microparticles showed a positive relationship with all macroinvertebrate’s microparticle abundance. Results will aid in understanding the ecological impacts of MPs on aquatic food webs and the pathways in which they can enter.

Sadomasochistic Sensations: A Phenomenological Analysis Of Black Ontology, Embodiment, And Transcendence, Sam Forrey

Master's Theses

Over the past fifteen years, feminists have challenged the notion that sexual sadomasochism perpetuates racial and gender-based violence, and instead claim that the practice can be a powerful site to control and subvert oppression. In this thesis, I contribute to this growing discourse and argue that sensations experienced during practices of Black sexual sadomasochism and attention to the feelings and affects that arise from them can be used to mediate Black being in a violently antiblack United States. Through applications of Black feminist thought, Black anti-humanism, and phenomenology, I claim that antiblack oppression denies Black people the experience of tactile …

The Skin Microbiome And Cutaneous T-Cell Lymphoma, Gail Hillary Lantaca Enriquez

Master's Theses

Skin microbiota is associated with disease activity in cutaneous T-cell lymphoma (CTCL). A common treatment for CTCL, narrowband ultraviolet B (nbUVB) phototherapy, has shown to shape the skin microbiome in association with disease improvement in other skin disorders such as atopic dermatitis. To assess the effect of nbUVB phototherapy on the skin microbiome, we performed a longitudinal analysis of skin samples of CTCL patients receiving nbUVB. We found that the treatment led to increased bacterial diversity and reduced abundances of Staphylococcus aureus and Staphylococcus lugdunensis, both bacteria known to be pathogenic. These findings imply that nbUVB treatment changes the skin …

Lactobacillus-Mediated Phage Induction And Inhibition Of Growth Of Escherichia Coli, Natalie Stegman

Master's Theses

Bacterial species inhabit both the “healthy” and symptomatic female urinary tract. Lactobacillus species are frequently dominant members of the healthy urinary tract microbiota (urobiome), and thus have been associated with the lack of lower urinary tract symptoms (LUTS). In contrast, colonization by Escherichia coli is the most common cause of urinary tract infections (UTIs). Prior research has found that strains of Lactobacillus can inhibit the growth of uropathogens such as E. coli as well as vaginosis-associated pathogens. Investigations into the means by which lactobacilli inhibit pathogenic growth have primarily focused on their production of hydrogen peroxide (H2O2) and lactic acid, …

Rebuilding Risk Assessment Tools And Evaluating Their Effect On Recidivism In Illinois, Cristina Penate

Master's Theses

This study seeks to examine the relationship between alternative measures of criminal history and recidivism in a cohort of convicted individuals released from prison in Illinois between 2010 and 2015. The current study expands on prior research by examining the relationship between prior criminal history and recidivism using alternative measures of both to account for potential bias resulting from differential policing activities that may lead to convictions. Traditionally, risk assessment instruments have relied on an individual’s total prior convictions for any offense and any re-arrest after release from prison. The current research developed a more nuanced measure of prior convictions …

Regulation Of Spermatogenesis By The Btb Transcription Factor Ribbon, Madeline Kyung Hee Hakala

Master's Theses

The transcription factor Ribbon (Rib) plays an essential role in Drosophila testis development and function. Increased expression of rib throughout development results in significant morphology defects in the adult testis. If overexpression is limited to germ cells and somatic cells in the adult, more mild defects are observed. To better understand how Rib regulates spermatogenesis, we are interested in identifying its transcriptional targets in this context. Through bulk RNA sequencing, differential expression analysis, and subsequent filtering of results, we identified 301 genes with significant changes in expression when rib was overexpressed. Given the previously described role of Rib in the …

Impacts Of Stormwater And Land Cover On The Abundance, Transport, And Composition Of Anthropogenic Litter In Urban Watersheds, Bailey Austin Schwenk

Master's Theses

Anthropogenic litter (AL; trash) is defined as any manufactured item that ends up in the environment. AL consists of many different materials including glass, metal, and plastic, the latter of which typically represents a dominant constituent and has been a major focus of research. Plastic litter and other AL types are pervasive to all types of ecosystems, are persistent in the environment, and are increasing. Rivers are a major conduit transporting AL to oceans. However, rivers also retain and transform AL. More research is needed to understand AL dynamics within rivers, which will improve global models of AL movement and …

Pattern, Process And The Evolution Of Sexual Dimorphism In Three-Spine Stickleback Fish Gasterosteus Aculeatus From Vancouver Island, British Columbia, Katie Van Dame

Master's Theses

Males and females of a species often differ from one another in phenotype—a phenomenon known as sexual dimorphism. Sexual dimorphism is most often attributed to sexual selection. However, sexual dimorphism also derives from natural selection when resource competition generates disruptive selection favoring specialization on different resources, resulting in niche partitioning and the evolution of dimorphism in traits related to competition. Sexual dimorphism may be an important route to increased individual fitness (i.e., more resources, more survival). For example, ecologically driven divergent selection between sexes may derive from differences in their environments, resulting in the evolution of dimorphism in traits related …

Design And Implementation Of An Inverted Short Baseline Acoustic Positioning System, Jakob Frabosilio

Master's Theses

This document details the design, implementation, testing, and analysis of an inverted short baseline acoustic positioning system. The system presented here is an above-water, air-based prototype for an underwater acoustic positioning system; it is designed to determine the position of remotely-operated underwater vehicles (ROVs) and autonomous underwater vehicles (AUVs) in the global frame using a method that does not drift over time.

A ground-truth positioning system is constructed using a stacked hexapod platform actuator, which mimics the motion of an AUV and provides the true position of an ultrasonic microphone array. An ultrasonic transmitter sends a pulse of sound towards …