Physical Sciences and Mathematics Commons^™

Structure Of The South-Central Skagit Gneiss Complex: Implications For Rheological Response To Magmatic Flare-Ups, Jeffery Wegener

Master's Theses

The Skagit Gneiss Complex in the North Cascades magmatic arc consists of Late Cretaceous to Eocene orthogneiss and partially migmatitic paragneiss. Orthogneiss protoliths intruded during two magmatic flare-ups, making the Skagit Gneiss an ideal location to study the relationship between flare-ups and deformation. Geologic mapping, microstructural analysis, and U-Pb dating of zircon were used to construct a timeline of magmatism, metamorphism and deformation in a portion of the Skagit Gneiss. A tonalitic gneiss intruded between ~79-73 at the beginning of the older flare-up and an ~60 Ma, tonalitic to granodioritic, leucocratic orthogneiss intruded at the end of this flare-up. NW-SE …

On The Colorability Of The Sphere Complex, Bennett Haffner

Master's Theses

One of the most prominently studied groups in geometric group theory is the outer automorphism group of the free group Out(F). The sphere complex provides a topological model for Out(F). We demonstrate the chromatic number of the sphere complex is finite.

Analyzing Live And Dead Fuel Moisture In California: Insights For Wildfire Management Decisions, Jack R. Drucker

Master's Theses

This study investigates trends in fuel moisture content (FMC) across California from 2000 to 2021. It utilizes two distinct sources of FMC data: the Fuel Moisture Repository, which integrates live fuel moisture content (LFMC) observations, and a novel dead fuel moisture content (DFMC) reanalysis product which provides spatial fuel moisture maps by integrating dead fuel moisture observations and a fuel moisture model driven by gridded weather data. The analysis uncovered a general downtrend in FMC across California, with the exception of LFMC in the Northernmost regions and coarse DFMC. Despite the differing long-term FMC trends, all the regions experienced a …

Assessing The Role Of Steam Explosivity In Shallow And Deep Marine Environments, Frederick Ede

Master's Theses

Volcaniclastic deposits formed in shallow and deep marine environments show strikingly different characteristics resulting from the ability of steam to assist in lava fragmentation. Deep marine deposits come from recent lava flows at Axial Seamount, formed around 1,500 m water depth, while shallow marine samples come from Miocene Columbia River Basalt Group (CRBG) lava flows that were emplaced in a shallow marine to subaerial environment and are now exposed on the Oregon coast. Volcaniclastic material from these two environments was compared using granulometry, componentry, and mapping. Lithofacies from the CRBG contained abundant ash and lapilli sized clasts with a high …

Remote Sensing With Airborne Infrared Thermography For Assessment Of Landscape Scale Wildfire Spread And Intensity, Christopher C. Giesige

Master's Theses

Wildland fire is one of the most complex environmental physical processes to quantify. The way in which we observe and measure wildland fire is critical in understanding how these processes drive fire dynamics. Fire behavior can be observed in several ways including the use of ground sensors and remote sensing packages aboard aircraft and satellites. Airborne sensors provide high spatial resolution and can provide high temporal resolution. Infrared thermography takes advantage of radiant heat transfer allowing for the study of fire characteristics such as fire spread and intensity. Aircraft observations utilizing infrared cameras have been a well-established method of fire …

Geological And Geophysical Model Of The Sand Wash Extensional Decollement, Utah, Brigham Louis Cardon

Theses and Dissertations

The Sand Wash Fault Zone (SWFZ) in the southern Uinta Basin is a significant extensional fault zone exhibiting complex deformation patterns. Our study integrates detailed structural analyses with a broader tectonic model to elucidate the tectonic evolution of the region. The SWFZ, extending over 34 km with a NW-SE strike, is underlain by an extensional decollement. Substantial deformation is observed in the upper layers, notably within the S2 sandstone of the Eocene Green River Formation. The deformation diminishes with depth, terminating at the oil-rich Mahogany oil shale zone, below which minimal deformation is observed. Our tectonic model, developed primarily through …

Mercury Exposure, Fuel Stores And Torpor Use In Silver Haired Bats, Melina Kuerschner

Electronic Thesis and Dissertation Repository

Methylmercury (MeHg) is an environmental contaminant that has a high biomagnification potential with potent neurotoxic effects. Insectivorous bats may be readily exposed to MeHg through their diet. To test the effect of exposure on torpor and body composition in silver-haired bats (Lasionycteris noctivagans), I measured total mercury (THg, combination of inorganic and methylmercury) through fur samples and quantitative magnetic resonance analysis, temperature sensitive radio tags, and respirometry data from these bats to quantify body composition and torpor use. THg levels varied 20-fold with heavier and fatter bats having higher levels, suggesting that individuals that routinely eat more accumulate …

Predictive Models Of Polymer Composites: A Thesis, Navid Afrasiabian

Electronic Thesis and Dissertation Repository

Predictive models are a powerful tool to understand and improve physical systems. Predictive models not only can be used to improve current materials, but they also gain fundamental understanding of the underlying processes. There are numerous theoretical and numerical models introduced in the field of polymer composites and nanocomposites. Different methods best describe a system at a specific time and length scale. In this thesis, I utilize Coarse-grained Molecular Dynamics (CGMD), Multi-PhaseField (MPF), and Lattice-Boltzmann (LB) methods to study different aspect of polymer composites and nanocomposites.

Starting at the nanoscale, we study the dispersion and orientation patterns of nanorod-polymer systems …

Coffee In Brasil: Sustainability And The Role Of Intermediaries, Livia Petzinger

Capstone Collection

ABSTRACT

Coffee is traded in a highly complex global value chain where countless sustainability initiatives have emerged to address social, economic, and environmental issues, challenges which persist due to dominance of the market structure by largescale traders and roasters. Specialty coffee and direct trade have emerged as alternative trade arrangements that promote high-quality coffee through the use of sustainable practices, transparency, and a shortened supply chain. This research analyzes the role that intermediaries in the Brazilian specialty coffee supply chain play in the implementation of sustainability initiatives asking what kinds of sustainability practices they implement and why, and how this …

Solar Photovoltaics As Climate Change Adaptations For Farmers In West Bengal, India: Barriers Within A Food-Water-Energy Nexus Approach, Emily Rochford

Capstone Collection

This capstone research project seeks to identify and address barriers to the use of solar photovoltaics (PV) as an adaptation method to climate change for farmers in West Bengal, India. These barriers are examined within the context of the food-water-energy nexus, particularly concerning the ability of many small holder farmers to produce their own food and sustain their livelihoods. Previous studies have examined both energy access and renewable energy development in West Bengal, and also the food-water-energy nexus in its application to climate change. However, there is minimal literature on how renewable energy development should be applied within the nexus …

Returning Power To The Mashpee Wampanoag Tribe: Energy Policy And Tribal Autonomy, Nicolas Land-Kazlauskas

Capstone Collection

This policy brief addresses tribal autonomy, energy policy, and the resources of the Mashpee Wampanoag Tribe in Massachusetts. Tribal sovereignty has been a difficult and often painful area of discussion for many tribal communities. For generations, tribes have had to carefully navigate their interactions with colonial forces and the residues of colonialist legacies, especially tied to resource wealth and decision-making. Even with the best of efforts by the tribe, their actions often have not impacted the basic legal or economic situations on-the-ground. Their on-going relationships with states and companies continue to undermine tribal autonomy and sovereignty oftentimes simply because they …

Multi-Species Toxicity Testing Of Iprnhc: A Candidate For Organic Coating Enhancements, Maryam Khalilvand Nahid

Electronic Thesis and Dissertation Repository

Corrosion is a natural process affecting the longevity and integrity of metals. N-Heterocyclic carbenes (NHCs) are robust organic compounds that can form strong σ-bonds with metal atoms, allowing for the formation of monolayers on the metal surface. This property makes NHCs promising for coating metals. However, their long-term effects on the aquatic environment are not well understood. The present study investigated the ecotoxicity of 1,3-diisopropyl-1H-benzoimidazolium bicarbonate (iPrNHC NCO₃^-), a candidate for organic coating enhancements, on various species of aquatic organisms. The results showed that high concentrations of iPrNHC significantly increased mortality rates in zebrafish embryos, planarians, Daphnia, …

Investigating Cloth Sculpting For Simulation Control In Virtual Reality, Matthew S. Bishop

Theses and Dissertations

Artists require control and predictability over physically based simulations to create their required animation. This control can lead to reduced iteration time to get the desired simulation results. Controlling cloth simulations can require manual effort to create goal keyframes for control algorithms to match. Current techniques and research utilize a keyboard and mouse to create these goal keyframes. Other research has looked at using a virtual reality (VR) head-mounted display with controllers to improve the experience of completing similar animation tasks. However, we are not aware of any research that attempts to use VR as a tool to assist artists …

De Novo Synthetic Studies On Tetracyclic Triterpenoid Systems: Stereoselective Preparation, Biological Evaluation And Total Syntheses Of Euphol And Tirucallol, Joshua Nicholson

Dartmouth College Ph.D Dissertations

Tetracyclic triterpenoids have a rich history in biology, medicine, and chemistry. In terms of pharmaceutical relevance, compounds with this scaffold are one of the most successful classes with over 100 FDA approved examples. Despite this success, the vast majority of compounds within this class are prepared through semisynthesis. While this approach is undeniably successful, judged by the sheer number of medications generated, it also has limitations. Namely, semisynthesis requires the use of complex starting materials that have fixed absolute stereochemistry and often sparse functionality. One approach to address the inherent limitations with semisynthesis is through de novo synthesis. Recently, our …

Modular Approach To Soft Mobile Robots, Dimuthu Kodippili Arachchige

College of Computing and Digital Media Dissertations

Soft robot locomotion is a highly promising but under-researched subfield within the field of soft robotics. The compliant limbs and bodies of soft robots offer numerous benefits, including the ability to regulate impacts, tolerate falls, and navigate through tight spaces. These robots have the potential to be used for various applications, such as search and rescue, inspection, surveillance, and more. The state-of-the-art still faces many challenges, including limited degrees of freedom, a lack of diversity in gait trajectories, insufficient limb dexterity, limited payload capabilities, lack of control methods, etc. To address these challenges, this research introduces a modular approach to …

Cellular Sorting Of The Dictyostelium Discoideum Slug, Erin Flowerday

Theses and Dissertations

Dictyostelium discoideum (Dd) cells are amoeba cells that feed on soil or plant leaf matter bacteria. They divide freely in the presence of food. When starved, cell division is ended, and cells transition from unicellular to multicellular organisms initiated by a chemoattractant, cyclic adenosine monophosphate (cAMP). This study intricately examines cellular sorting within the Dd slug, focusing on individual cell dynamics. Represented as oriented ellipsoids, these cells maintain constant volume through a viscoelastic structure. Applying force to specific semi-axes reveals predictable deformations, highlighting the relationship between force and deformation rate. Manipulating damping coefficients and spring constants uncovers insights into cell …

Investigating The Stability Of Different Sizes Of Gold Nanoparticles In Physiological Environments And Different Gold Nanoclusters In Water., Narges Hajighasemi

Electronic Thesis and Dissertation Repository

Gold nanoparticles (AuNPs) have become promising candidates for various biomedical applications due to their unique physicochemical properties and biocompatibility. Nevertheless, the efficacy of AuNPs in these applications highly relies on their stability and ability to maintain their desired properties within the complex environment of the human body. This thesis investigates the stability and aggregation behavior of citrate-coated AuNPs in in-vitro physiological environments and nitrogen heterocyclic carbene (NHC)-coated gold nanoclusters (AuNCs) in water over time. Analytical techniques such as electrophoretic mobility, dynamic light scattering, and inductively coupled plasma mass spectrometry were employed. It was shown that cell media (in contrast to …

Maximizing Legged Accelerations: A Matter Of Force, Time, And Gravity, Lance Brooks

Applied Physiology and Wellness Theses and Dissertations

Sprint running accelerations require runners to apply surface forces that: support body weight by pushing downward, accelerate the body horizontally by pushing backward, and align the direction of the push with the body’s mass center to maintain balance and posture, which imposes an upper limit on the average forward acceleration force equal to the average gravitational force (1.0 G) acting on the runner. This expectation arises from the mechanical constraints imposed by the need to generate sufficient vertical force to support body weight against gravity while simultaneously producing horizontal force to accelerate forward and aligning the push through the center …

Constraints On Solar Axions Using The Profile Likelihood Ratio Method With The Supercdms Experiments, Shilun Liu

Physics Theses and Dissertations

Dark matter plays an essential role in understanding modern physics and particles beyond the Standard Model. Evidence suggests that dark matter accounts for approximately 85% of the universe’s matter, and 26.8% of its mass-energy composition. Key candidates for dark matter include unidentified subatomic particles like Weakly Interacting Massive Particles (WIMPs) and axions. The Super Cryogenic Dark Matter Search (SuperCDMS) employs direct detection methods to identify these elusive particles using cryogenic technologies. Su- perCDMS Soudan is the latest completed CDMS experiment in Minnesota, in preparation for the next phase experiments of SuperCDMS SNOLAB in Sudbury, Canada. At SNOLAB, the Cryogenic Underground …

Enhancing Fundraising Strategies In Higher Education Through Machine Learning, Laith Alatwah

Electrical Engineering Theses

This thesis presents a comprehensive application of machine learning techniques, namely Fine Gaussian SVM and RUS Boosted Trees, to enhance fundraising strategies in higher education institutions. Analyzing a rich dataset from Blackbaud Raiser's Edge NXT, spanning 2012 to 2022, the study focuses on donor profiles, including demographics, donation history, and engagement patterns. Key demographic insights include the increasing engagement of younger donors (20-29 age group) and significant contributions from older donors (70-99 age group). Geographical trends are also examined, revealing distinct patterns based on donors' city, state, and ZIP code. The Fine Gaussian SVM model demonstrates moderate discriminatory power, with …

Bayesian Variational Inference In Keyword Identification And Multiple Instance Classification, Yaofang Hu

Statistical Science Theses and Dissertations

This dissertation investigates (1) Variational Bayesian Semi-supervised Keyword Extraction and (2) Variational Bayesian Multimodal Multiple Instance Classification.

The expansion of textual data, stemming from various sources such as online product reviews and scholarly publications on scientific discoveries, has created a demand for the extraction of succinct yet comprehensive information. As a result, in recent years, efforts have been spent in developing novel methodologies for keyword extraction. Although many methods have been proposed to automatically extract keywords in the contexts of both unsupervised and fully supervised learning, how to effectively use partially observed keywords, such as author-specified keywords, remains an under-explored …

Bayesian And Deep Generative Modeling In Immunology, Yuqiu Yang

Statistical Science Theses and Dissertations

Due to the accumulation of a large volume of data of different natures such as sequencing data, proteomics data, and clinical data, statistical methods and deep learning algorithms have become increasingly important in the field of immunology. By leveraging the diverse datasets as well as interdisciplinary knowledge from areas like biology and public health, these quantitative methods have revolutionized this field by providing powerful tools for data analysis, modeling, and prediction. This has led to a deeper understanding of the immune system, accelerated the development of novel therapies, and paved the way for personalized and precision medicine approaches in immunology. …

Development And Optimization Of A 1-Dimensional Convolutional Neural Network-Based Keyword Spotting Model For Fpga Acceleration, Trysten E. Dembeck

Masters Theses

Spoken Keyword Spotting (KWS) has steadily remained one of the most studied and implemented technologies in human-facing artificially intelligent systems and has enabled them to detect specific keywords in utterances. Modern machine learning models, such as the variants of deep neural networks, have significantly improved the performance and accuracy of these systems over other rudimentary techniques. However, they often demand substantial computational resources, use large parameter spaces, and introduce latencies that limit their real-time applicability and offline use. These speed and memory requirements have become a tremendous problem where faster and more efficient KWS methods dominate and better meet industry …

Mapping Urban Tree Canopy Using Publicly Available Satellite Data, Rosemary Mcguinness

Theses and Dissertations

This project addresses the need for accessible, cost-effective tools for quantifying spatial and temporal changes in tree canopy cover in urban areas. Urban tree canopy provides a wide range of ecosystem services, including lowering air temperatures, reducing pollution, and mitigating stormwater runoff. Cities around the world have placed the expansion of their urban forests at the center of their sustainability goals. Consistent and timely data on urban tree canopy is essential for urban greening initiatives to succeed. Existing methods of accessing information about urban tree canopy are highly technical, costly, and labor-intensive, while the freely available source of tree canopy …

Optimizing The Protein Yield Of The Collagen Mimetic Peptide: Col108, Fahmida Akter

Theses and Dissertations

Abstract

The fibril-forming collagen mimetic peptide Col108, produced in E. Coli, has shown potential for innovative biomaterial applications. However, further research is constrained by its limited yield. My study aims to enhance the experimental parameters and has successfully pinpointed rifampicin as an efficient method to boost the production of Col108.

Container Migration: A Perfomance Evaluation Between Migrror And Pre-Copy, Xinwen Liang

Electronic Thesis and Dissertation Repository

The concept of migration and checkpoint/restore has been a very important topic in research for many types of applications including any distributed systems/applications or single massive systems/applications; and low latency vehicular use cases, augmented reality(AR) and virtual reality(VR) applications. Migrating a service requires that the state of the service is preserved. This requires checkpointing the state and restoring it on a different server in multiple rounds to avoid a total loss of all data in case of a failure, fault or error. There are many different types of migration techniques utilized such as cold migration, pre-copy migration, post-copy migration.

Compared …

Single Charge Carrier Dynamics In A Single Polymer Chain, Ming Lei

All Dissertations

Understanding how charge carrier move through conjugated polymers is crucial for optimizing the functionality and efficiency of various applications, from organic solar cells and light-emitting diodes (LEDs) to field-effect transistors. Previous studies have demonstrated that tracking the fluorescence centroid displacement provides a method to determine the position of single charge carriers in a conjugated polymer nanoparticle. This method allows the observation of charge carrier trajectories over time and allow researchers to obtain insights into the dynamic processes. In addition, a detailed map of the energy landscape can be constructed by analyzing the fluorescence spectrum. These techniques were previously applied to …

Offensive Content Detection In Online Social Platforms, Ebuka Okpala

All Dissertations

Online social platforms enable users to connect with large, diverse audiences and the ability for a message or content to flow from one user to another user, user to followers, followers to user, and followers to followers. Of course, the advantages of this are apparent, and the dangers are also clearly obvious. The user-generated content could be abusive, offensive, or hateful to other users, possibly leading to adverse health effects or offline harm. As more of society's public discourse and interaction move online and these platforms grow and increase their reach, it is inherently important to protect the safety of …

Assessment Of Tce And Chiral Pcb Dechlorination Rate, Congener Diversity, And Enantioselectivity In Town Creek, Sc, Usa Sediment Microcosms, Catherine P. Sumner

All Dissertations

Polychlorinated biphenyls (PCBs) and trichloroethene (TCE) are ubiquitous contaminants and are recognized as persistent organic pollutants due to their extreme chemical stability. PCBs were manufactured by chlorinating biphenyls that created 209 congeners with various structures, of which 19 are chiral and can exist as a pair of stable atropisomers. PCBs have been known to cause developmental and neurological toxicity in humans and wildlife; they can act as endocrine disrupters, carcinogens, and teratogens. Sangamo Weston Inc. was an industrial plant located near Town Creek in Pickens Country, South Carolina, that manufactured capacitors and used Aroclors 1016 and 1254 as dialectic fluids …

Ensuring The Privacy Compliance Of Voice Personal Assistant Applications, Song Liao

All Dissertations

Voice Personal Assistants (VPA) such as Amazon Alexa and Google Assistant are quickly and seamlessly integrating into people’s daily lives. Meanwhile, the increased reliance on VPA services raises privacy concerns, such as the leakage of private conversations and sensitive information. Privacy policies play an important role in addressing users’ privacy concerns and developers are required to provide privacy policies to disclose their apps’ data practices. In addition, voice apps targeting users in European countries are required to comply with the GDPR (General Data Protection Regulation). However, little is known about whether these privacy policies are informative and trustworthy on emerging …