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Water Quality Monitoring And Mapping Using Rapidly Deployable Sensor Nodes, Mohamed Abdelwahab Oct 2023

Water Quality Monitoring And Mapping Using Rapidly Deployable Sensor Nodes, Mohamed Abdelwahab

Theses and Dissertations

Efficient and continuous monitoring of water quality parameters plays a pivotal role in responding to pollution incidents and ensuring the safety of both human consumption and ecological resources. This research introduces an affordable and dependable in-situ water quality sensor package designed for seamless continuous monitoring, providing essential data to facilitate informed decision-making in water resource management. The sensor package enables comprehensive on-site assessment of key water characteristics, including pH, temperature, turbidity (measured in NTU), and total dissolved solids (TDS, measured in ppm). Spatial interpolation techniques, specifically Kriging, are employed to extrapolate variable values at unobserved locations based on nearby measurements. …


Enhancing Relation Database Security With Shuffling, Tieming Geng Oct 2023

Enhancing Relation Database Security With Shuffling, Tieming Geng

Theses and Dissertations

Database security holds paramount importance as it safeguards an organization's most valuable assets: its data. In an age marked by escalating cyber threats, protecting sensitive information stored in databases is essential to preserve trust, prevent financial losses, and maintain legal compliance. In this dissertation, an exploration into the realm of relation database security is undertaken. The research introduces a cryptographic secure shuffling algorithm designed to fortify database security. Additionally, the dissertation presents a series of innovative solutions aimed at bolstering both the security and efficiency of the shuffling algorithm. Encryption algorithms have long served as a mean of safeguarding sensitive …


The Utility Of Bayesian Predictive Models To Forecast Arboviruses In The United States Of America And Territories, Maggie Suzanne Jennave Mccarter Oct 2023

The Utility Of Bayesian Predictive Models To Forecast Arboviruses In The United States Of America And Territories, Maggie Suzanne Jennave Mccarter

Theses and Dissertations

Statistical models have been utilized to understand and forecast infectious diseases across the globe. However, these models have historically been difficult to access and interpret for non-specialist audiences. This dissertation focuses on one computationally efficient model fitting method, the integrated nested LaPlace approximation approach, to forecast three arboviruses in hopes of encouraging accessibility to statistical modelling. Such accessibility could provide areas who simultaneously are most susceptible to infection, and have the least resources, an invaluable tool for informing policy and prevention decisions. The resulting models included biological, land cover, and environmental factors and produced accurate forecasts of neuroinvasive West Nile …


Impact Of Steroid Receptor And Hormone Manipulation In Skeletal Muscle: Implications For Glucose Metabolism And Insulin Sensitivity In Male Mice, Christian Aaron Unger Oct 2023

Impact Of Steroid Receptor And Hormone Manipulation In Skeletal Muscle: Implications For Glucose Metabolism And Insulin Sensitivity In Male Mice, Christian Aaron Unger

Theses and Dissertations

This dissertation aimed to investigate the influence of modifying steroid receptor content and steroid production within skeletal muscle on glucose metabolism and insulin sensitivity within the context of diet-induced obesity. Specifically, our research focused on three key aspects:1) determining the role that skeletal muscle androgen receptor has on glucose metabolism and insulin action in male mice fed a high-fat diet and 2) determining if inducible skeletal muscle aromatase overexpression improves glucose intolerance and insulin action in male mice fed a high-fat diet and 3) determining if inducible skeletal muscle estrogen-receptor alpha (ER-α) overexpression improves glucose intolerance and insulin action in …


Integrated Wastewater Surveillance For Sars-Cov-2 And Antibiotic Resistant Bacteria: Implications For Public Health And Environmental Management, Mirza Isanovic Oct 2023

Integrated Wastewater Surveillance For Sars-Cov-2 And Antibiotic Resistant Bacteria: Implications For Public Health And Environmental Management, Mirza Isanovic

Theses and Dissertations

While current technologies have inadvertently resulted in wastewater treatment plants (WWTPs) becoming major sources of global antibiotic resistance gene (ARG) dissemination, wastewater can be leveraged to provide vital community-level health information. This project examined both of these aspects through wastewater-based surveillance of SARS-CoV-2 and metagenomic analysis of specific ARGs collected from both activated sludge and bioaerosols. In this study, we investigated treatment steps between the influent and final treated effluent to identify the point at which viral RNA is below detection. Additionally, we examined air surrounding high turbulence treatment steps to test for the presence of SARS-CoV-2 RNA in WWTP-generated …


Understanding The Impact Of Adverse Childhood Experiences On Borderline Features And Deliberate Self-Harm Behaviors Among College Students: The Mediating Roles Of Emotion Regulation And Interpersonal Functioning, Sydney Mari Levine Oct 2023

Understanding The Impact Of Adverse Childhood Experiences On Borderline Features And Deliberate Self-Harm Behaviors Among College Students: The Mediating Roles Of Emotion Regulation And Interpersonal Functioning, Sydney Mari Levine

Theses and Dissertations

Research has established ACEs as significant predictors of deliberate self-harm (DSH) in both clinical and community populations. Further, adults meeting criteria for borderline personality disorder (BPD) are nearly 14 times more likely to report childhood adversity. No previous studies have examined the critical roles of emotion regulation and interpersonal functioning as mediating mechanisms in these relations. Thus, the current study explored the mechanism by which ACEs affect borderline personality features (BPF) or deliberate self-harm through emotion regulation and interpersonal functioning in a sample of emerging adult college students. Participants (N = 2,255, M age = 19.25) included college students from …


Effects Of Chronic Stress On Working Memory Are Sex-Specific And Age-Dependent, Tyler Jamison Cox Oct 2023

Effects Of Chronic Stress On Working Memory Are Sex-Specific And Age-Dependent, Tyler Jamison Cox

Theses and Dissertations

As the aging demographic of the United States expands, the convergence of age-related cognitive decline and stress-related dysregulation emerges as a substantial concern, impacting not only the lifespan but also the overall well-being of American citizens. In the realm of research, there has been a pronounced focus on Alzheimer's Disease, leading to an imbalanced allocation of resources compared to the study of normal aging. It is widely acknowledged that executive function deteriorates as individuals age, a concept substantiated by numerous investigations conducted in labs dedicated to the study of normal aging. Significantly, even among individuals afflicted with neurodegenerative disorders affecting …


Studies Of Damage Tolerance In Automated Fiber Placement Based Heterogeneous Meso-Architectured Carbon/ Epoxy Composite Laminates., Karan Kodagali Oct 2023

Studies Of Damage Tolerance In Automated Fiber Placement Based Heterogeneous Meso-Architectured Carbon/ Epoxy Composite Laminates., Karan Kodagali

Theses and Dissertations

Traditional unidirectional (UD) carbon fiber-reinforced polymer matrix composites manufactured via automated fiber placement (AFP) are widely used in aerospace structures. While heterogeneous at the micro-scale, these materials are homogeneous at the meso-scale (ply-scale). The major limitation is its limited toughness, poor damage tolerance/impact resistance capability and the inability to sufficiently redistribute stresses, resulting in strength-toughness tradeoffs, making them susceptible to impact damage. From previous studies, there is an understanding that fiber architecture has a first order effect on the damage tolerance. Introducing new discontinuous/heterogeneous meso-scale architectures, through an optimal merger of material and structure, can result in unprecedented property improvements …


Quantification Of The Internalization Of A Commercially Available Silver Nanoparticle To The Bacterium Escherichia Coli, Samantha Mcneal Case Oct 2023

Quantification Of The Internalization Of A Commercially Available Silver Nanoparticle To The Bacterium Escherichia Coli, Samantha Mcneal Case

Theses and Dissertations

Nanoparticles (NPs), materials with dimensions ranging from 1 to 100 nanometers, are widely used in various consumer products, with silver nanoparticles (AgNPs) being the most prominent. Exposure to AgNPs occurs through multiple sources, including food packaging, supplements, and disinfectants, owing to their antimicrobial properties. Prior research has identified adverse health effects, such as cytotoxicity, toxicity, and Ag bioaccumulation resulting from AgNP exposure to bacteria in biological systems and the environment. However, most studies employ pristine, highly concentrated NPs, which may not accurately represent realistic exposure scenarios at environmentally relevant concentrations. This project investigates the fate and internalization of AgNPs, found …


The Genetic Associations Of Circadian Rhythm And Sleep Disorder Traits With Risk Of Monoclonal Gammopathy Of Undetermined Significance And Multiple Myeloma, Brittany Crawford Oct 2023

The Genetic Associations Of Circadian Rhythm And Sleep Disorder Traits With Risk Of Monoclonal Gammopathy Of Undetermined Significance And Multiple Myeloma, Brittany Crawford

Theses and Dissertations

Background: Circadian rhythm disruption and sleep have been widely studied for their roles in immunity and cancer development. Evidence for an association of circadian rhythm and sleep traits with multiple myeloma (MM) risk is inconclusive. No studies have investigated these traits in relation to monoclonal gammopathy of undetermined significance (MGUS). Given that MGUS precedes almost all MM cases, investigating sleep and circadian rhythm in relation to both MM and MGUS is necessary. The purpose of this dissertation was to explore the genetic influences of circadian rhythm and sleep traits on the risk of MGUS and MM. Methods: Data were leveraged …


Recycling Of Electrode Materials From Spent Lithium-Ion Batteries To Develop Supercapacitor Devices, Yasmine Mesbah Oct 2023

Recycling Of Electrode Materials From Spent Lithium-Ion Batteries To Develop Supercapacitor Devices, Yasmine Mesbah

Theses and Dissertations

Recently, there has been a rapid expansion in the utilization of lithium-ion batteries (LIBs) due to the propagation of portable electronic devices, electric vehicles, and renewable energy storage systems. Despite the plentiful advantages provided by LIBs, concerns have emerged regarding resource depletion and the environmental impact associated with their widespread use. The lack of essential resources such as lithium, cobalt, and nickel, along with the difficulties associated with managing battery waste, necessitates the development of sustainable strategies that encompass the entire lifecycle of LIBs. Recycling has arisen as a promising solution to combat these challenges and promote a more circular …


What's Your Type? The Relationship Between Enneagram Personality Style And Psychiatric Diagnosis, Danielle Augusta Huber Oct 2023

What's Your Type? The Relationship Between Enneagram Personality Style And Psychiatric Diagnosis, Danielle Augusta Huber

Theses and Dissertations

Despite its long history and ever-growing popularity amongst mental health providers and laypeople, the Enneagram model of personality has seen limited empirical support regarding its clinical relevance and efficacy. The present study sought to contribute to the literature supporting the Enneagram’s use in psychotherapy. As a majority of therapeutic services aim for the reduction and/or resolution of psychopathology, often in terms of one or more diagnoses, and as previous research has theorized how the Enneagram model and psychiatric diagnoses might be related (Palmer, 1988), it was the researchers’ intention to analyze whether these theoretical associations could be statistically supported. This …


A Work Towards A Single-Bridge Hydrazine Sensor, Brenden Jay Schmeltz Oct 2023

A Work Towards A Single-Bridge Hydrazine Sensor, Brenden Jay Schmeltz

Theses and Dissertations

Hydrazine can currently be detected by irreversible methods, Carbazolopyridinophane (2,18-Dithia[3][1,8]carbazolo[3][2,6]pyridinophane) CP was synthesized by Brown et al. to detect hydrazine in real-time while also being reversible. The threshold for detection was 100 ppb, regulatory use requires 10 ppb as this is when permanent damage to humans can be caused. A more sensitive sensor will allow for safer workplaces for many people. A single, 3-atom bridge sensor will further examine the photophysical capabilities of carbazole-pyridine as an emitter/quencher pair. 1-Carbazole-1-methylpyridyl-2methyl sulfide SBCP will allow freedom of rotation as well as the bending of the bridge. These benefits will introduce conformers which …


Fundamental Study Of Ionic Liquid Physicochemical Effects On Thermal Stability Of Model Biological Macromolecules, Austin Keith Clark Sep 2023

Fundamental Study Of Ionic Liquid Physicochemical Effects On Thermal Stability Of Model Biological Macromolecules, Austin Keith Clark

Theses and Dissertations

Ionic Liquids (ILs) are substances with a unique physical attribute compared to that of solid ionic salts. At room temperature, ILs are molten salts that have a variety of physical effects that can play a role in their impact on other molecules, as solvents or solutes. They can play the role of the solvent in a variety of applications, from biofuels to organic catalysis or as excipients in pharmaceutical formulations. These ILs have a desirable use as solvents due to their ability to be tunable substances. Changing the cation or anion of the IL causes a change in its physical …


Mechanistic Investigations Of A Novel Braf Regulatory Switch And Braftide, An Allosteric Peptide Inhibitor Of Braf, Alison Yu Sep 2023

Mechanistic Investigations Of A Novel Braf Regulatory Switch And Braftide, An Allosteric Peptide Inhibitor Of Braf, Alison Yu

Theses and Dissertations

RAF kinases (ARAF/BRAF/CRAF or Raf-1) are serine/threonine kinases in the MAPK (RAS-RAF-MEK-ERK) pathway. The MAPK pathway is crucial in development and normal cell function. These same roles are dysregulated in cancer; BRAF is the most frequently mutated isoform in cancers and in particular, activation loop mutants BRAF V600E/K mutants have the highest mutational incidence. Three FDA approved inhibitors potently inhibit BRAF V600E/K mutants. However, these same inhibitors fail to address the non-V600E/K mutations and result in paradoxical activation of the MAPK pathway. Two strategies were employed to address the limitations of the FDA-approved inhibitors: provide novel regulatory details of RAF …


Design And Development Of Clinical Decision Support System For Breast Cancer Diagnosis Using Artificial Intelligence, Karthiga R Sep 2023

Design And Development Of Clinical Decision Support System For Breast Cancer Diagnosis Using Artificial Intelligence, Karthiga R

Theses and Dissertations

The prevalence of breast cancer in women worldwide is far higher than that of cancers of the lungs, brain, or liver. Increasing ageing populations and poor lifestyle habits among the general public, primarily in industrialized nations, are significant factors contributing to the rise in cancer-related mortality rates worldwide. Approximately one woman in every three will develop breast cancer. This research proposes several advanced computer methods for analyzing breast cancer images. This work analyses breast cancer in four imaging modalities: mammography, thermography, ultrasonography and histopathology.

Each modality has some limitations in diagnosing tumors in the breast region. Heavy dose in mammogram …


Combining Expert Opinions To Assess Risk Of Change In Earth Systems: Permafrost Collapse, Global Wildfire, And Water Security, Sayedeh Sara Sayedi Sep 2023

Combining Expert Opinions To Assess Risk Of Change In Earth Systems: Permafrost Collapse, Global Wildfire, And Water Security, Sayedeh Sara Sayedi

Theses and Dissertations

In a world of uncertainty and change, leaders should base their decisions on best available scientific evidence. However, history has shown that science is often inadequately incorporated into the decision-making process. This dissertation investigates three environmental issues to identify the challenges of considering Earth system dynamics in policymaking and management. I also propose solutions for improving the two-way exchange of knowledge and values between researchers and policymakers. In chapter one, I investigate subsea permafrost carbon sensitivity to climate change using an expert assessment. The analysis revealed that subsea permafrost contains significant carbon stocks and is already contributing to climate change …


Sctiger: A Deep-Learning Method For Inferring Gene Regulatory Networks From Single-Cell Gene Expression Data, Madison Dautle Sep 2023

Sctiger: A Deep-Learning Method For Inferring Gene Regulatory Networks From Single-Cell Gene Expression Data, Madison Dautle

Theses and Dissertations

Inferring gene regulatory networks (GRNs) from single-cell RNA-sequencing (scRNA-seq) data is an important computational question to reveal fundamental regulatory mechanisms. Although many computational methods have been designed to predict GRNs, none work on condition specific GRNs by directly using paired datasets of case versus control experiments, common in diverse biological research projects. We present a novel deep-learning based method, scTIGER, for GRN detection by using the co-dynamics of gene expression. scTIGER also employs cell type-based pseudotiming, an attention-based convolutional neural network method, and permutation-based significance testing to infer GRNs from gene modules. We first applied scTIGER to scRNA-seq datasets of …


Investigations On Copper Assisted Oxidative Transformations For The Construction Of Diverse C-C/C-N(O) Bonds, Prasanna Kumari S Sep 2023

Investigations On Copper Assisted Oxidative Transformations For The Construction Of Diverse C-C/C-N(O) Bonds, Prasanna Kumari S

Theses and Dissertations

Copper catalyzed C-C, C-N/C-O bond formation reactions are a prominent tool to access diverse biologically relevant molecules. Herein, we present the copper- catalyzed diverse C-C/C-N(O) bond forming reactions. In Chapter-I (introduction), we briefly discussed the various copper mediated organic transformations with appropriate examples.

In Chapter II, we report a one-pot methodology for the vicinal aminoalkylation of naphthoquinone through a direct C(sp2)-H functionalization reaction. Through this method, readily available planar naphthoquinone substrates were transformed into three-dimensional molecular scaffolds through the formation of one C(sp2)-C(sp2) and two C(sp2)-N bonds. The indole fused nitrogen heterocyclic products were obtained in good yields. Apart from …


Development Of An Antibiotic Resistance Breaker To Combat Staphylococcus Aureus Pathogenesis Skin Infections Ssis A Multidisciplinary, Gopalakrishnan T Mr Sep 2023

Development Of An Antibiotic Resistance Breaker To Combat Staphylococcus Aureus Pathogenesis Skin Infections Ssis A Multidisciplinary, Gopalakrishnan T Mr

Theses and Dissertations

Problem Statement: Staphylococcus aureus is a highly adaptable and tenacious pathogen known to cause a wide range of infections. The survival characteristics of the pathogen in different host niches are due to their ability to produce various pathogenic determinants. Although there lies the first line of treatment regimens with antibiotics, the pathogen defends at various levels to cause the waves of resistance - a silent pandemic “AMR”.

Notable strategies are through the protective layer, biofilm that enables the inter-/intra species communication (Quorum Sensing; QS) and emerges as a battleground to withstand host-immune response and antibiotic pressure. In parallel, several research …


Interrogating And Genetically Improving Drought Tolerance In The Oilseed Winter Cover Crop, Pennycress ( Thlaspi Arvense L. )., Carol S. Kiam Assato Sep 2023

Interrogating And Genetically Improving Drought Tolerance In The Oilseed Winter Cover Crop, Pennycress ( Thlaspi Arvense L. )., Carol S. Kiam Assato

Theses and Dissertations

Drought damage to crops is a significant threat to food security and a growing problem due to climate change. Amongst all abiotic stresses, drought is the most impactful on soil biota and crop productivity. According to the National Integrated Drought Information System (NIDIS), in 2020, 40% of the United States was under drought, and it is predicted that this number will continue to rise in the forthcoming years due to global warming. Pennycress (Thlaspi arvense L.) is a member of the Brassicaceae family related to canola and Arabidopsis that is rapidly being developed as an oilseed-producing winter cash cover crop …


Refining Contract Management: Essays On Relational Contracting, Transaction Costs, And Text Analysis, Timothy E. Landucci Sep 2023

Refining Contract Management: Essays On Relational Contracting, Transaction Costs, And Text Analysis, Timothy E. Landucci

Theses and Dissertations

This dissertation refines defense contracting by addressing aspects of managing contractual relationships. While the setting and data relate to defense contracts, the lessons can be expanded to nonprofit contracting beyond defense and even to contract management in general. First it presents a game theoretic model of a relational contract between a for-profit supplier and a non-profit buyer and explores how the model could be used to promote stability, manage costs, enhance cooperation, and encourage long-term capacity. The dissertation then explores governance alignment using transaction cost economics (TCE) and Department of the Air Force contracting data. One analysis uses data from …


Removal Of Diclofenac Pharmaceutical Residues From Wastewater, Fatma Aly Aug 2023

Removal Of Diclofenac Pharmaceutical Residues From Wastewater, Fatma Aly

Theses and Dissertations

As diseases worldwide and in Egypt are increasing by time, developing, and producing new medicines is massively expanding. The use of pharmaceutical compounds is rising worldwide. Diclofenac compound is used in plenty of different kinds of drugs as a nonsteroidal anti-inflammatory drug “NSAID” treating inflammation, osteoarthritis and rheumatoid. Due to excessive exposure to diclofenac -from humans and animals, large amounts are found in the water streams and the environment. Most of the conventional treatment methods is not capable of the complete removal of the diclofenac. Therefore, most of it is thrown back into the water bodies badly affecting the environment, …


Gene Dive: Assessing The Diversity Of Perchlorate Reducing Genes In Mars Analog Environments, Colin Michael Robinson Aug 2023

Gene Dive: Assessing The Diversity Of Perchlorate Reducing Genes In Mars Analog Environments, Colin Michael Robinson

Theses and Dissertations

Biotic perchlorate reduction, a metabolic process that potentially occurs on Mars, has long been the subject of speculation in astrobiology. To determine whether it could be a viable metabolic strategy on the Red Planet, we sought to determine whether biotic perchlorate reduction could evolve and persist in Mars-analog environments on Earth. In this study, we introduce Gene Dive, a novel computational methodology that leverages profile hidden Markov models, sequence alignment, phylogenetic tree construction, and Faith's phylogenetic diversity to probe the prevalence and diversity of perchlorate reducing genes in metagenomes. To determine whether biotic perchlorate reduction persists in a wide range …


"The Trees Act Not As Individuals"--Learning To See The Whole Picture In Biology Education And Remote Sensing Research, Rebeka A.F. Greenall Aug 2023

"The Trees Act Not As Individuals"--Learning To See The Whole Picture In Biology Education And Remote Sensing Research, Rebeka A.F. Greenall

Theses and Dissertations

To increase equity and inclusion for underserved and excluded Indigenous students, we must make efforts to mitigate the unique barriers they face. As their knowledge systems have been historically excluded and erased in Western science, we begin by reviewing the literature on the inclusion of Traditional Ecological Knowledge (TEK) in biology education and describe best practices. Next, to better understand how Native Hawaiian and other Pacific Islander (NHPI) students integrate into the scientific community, we used Social Influence Theory as a framework to measure NHPI student science identity, self-efficacy, alignment with science values, and belonging. We also investigated how students …


Phosphorus Sorption And Kinetics Across The Sediment-Water Interface Of Utah Lake, A Shallow Eutrophic Lake, Forrest Fielding Stretch Jarvis Jarvis Aug 2023

Phosphorus Sorption And Kinetics Across The Sediment-Water Interface Of Utah Lake, A Shallow Eutrophic Lake, Forrest Fielding Stretch Jarvis Jarvis

Theses and Dissertations

Internal sediment phosphorus (P) cycling may regulate harmful algal blooms (HABs) in shallow eutrophic lakes. Utah Lake frequently experiences HABs despite its high alkalinity and P-rich sediment. Phosphorus cycling between the lakebed and the water column is dependent upon stable P-sorption with organic matter (OM) and mineral species, which can vary with substrate availability, P-concentrations, temperature, redox, pH, and microbial activity. A full biogeochemical analysis of the water and sediment across seven sites shows Utah Lake to be spatially well-mixed in terms of composition and sorption, with few exceptions. Sediment P-concentrations (avg. 677 mg-P kg-1) primarily correlate with redox-sensitive iron …


Food Web Of Icy Strait, Alaska: Comparison Of Position, Size, And Overlap Of Trophic Niche Among Fish Species, Andrew D. Suchomel Aug 2023

Food Web Of Icy Strait, Alaska: Comparison Of Position, Size, And Overlap Of Trophic Niche Among Fish Species, Andrew D. Suchomel

Theses and Dissertations

The Icy Strait of southeast Alaska, USA is an ideal system to study how ecological diversity is maintained. This area has historical ecological significance and supports diverse assemblages of fish species that are easily sampled. We used stable isotope analysis using δ13C and δ15N stable isotope ratios. Using these isotope ratios, we quantified trophic niche position, size, and overlap and compared how those trophic niche metrics varied using ecological and evolutionary perspectives. For ecological variation, mean total length, and δ13C trophic niche position has positive relationships with trophic niche size while total percent trophic niche overlap had a strong negative …


Designed For Better Control: Using Kinematic And Dynamic Metrics To Optimize Robot Manipulator Design, John R. Morrell Aug 2023

Designed For Better Control: Using Kinematic And Dynamic Metrics To Optimize Robot Manipulator Design, John R. Morrell

Theses and Dissertations

In the field of control theory, optimal performance is generally defined as the best possible controlled performance given a static, unchangeable plant system. However, principled design of the underlying system can make designing effective controllers easier and dramatically improve the final control performance beyond what any finely tuned controller could achieve alone. This work develops performance metrics for serial robot arms which help guide the design and optimization of the structure of the arm to achieve greater final performance. First, a kinematic (motion-based) metric called the Actuator Independence Metric (AIM) measures the uniqueness of the movement capabilities of the different …


Measuring Microparticle Adhesion Via High-Speed Rotor, Jacob C. Fearnley Aug 2023

Measuring Microparticle Adhesion Via High-Speed Rotor, Jacob C. Fearnley

Theses and Dissertations

Much is known about the atomic/molecular theories that govern adhesion as well as the macroscopic aspects and properties of adhesion. However, adhesion in the microparticle regime is poorly characterized. We report on experiments that use centrifugal force to remove polystyrene (PS) particles from the surface of a high-speed titanium rotor operated in vacuum. This unique rotor can apply forces far greater than other centrifugal force methods or related techniques using atomic force spectroscopy. The mode of attachment, whether particles were located on the windward side versus leeward side of the spinning rotor, time spent in vacuum prior to experiments, and …


Detailed Characterization Of Material Deformation, Alexander J. Farnsworth Aug 2023

Detailed Characterization Of Material Deformation, Alexander J. Farnsworth

Theses and Dissertations

This dissertation presents a comprehensive exploration of material deformation at the atomic level, investigating key findings and contributions through three fundamental methods: Sum Frequency Generation Spectroscopy (SFG), X-ray Diffraction (XRD), and Electron Backscatter Diffraction (EBSD). The research commences by uncovering the material dependency of nonresonant responses in both SFG and Second Harmonic Generation (SHG) signals. This redefinition of the nonresonant component as an information-rich carrier, rather than mere background noise, leads to novel insights into the potential applications of SFG. The study then delves further into the influence of mechanical stress on materials, establishing a connection between dislocation density on …