Physical Sciences and Mathematics Commons^™

Electrostatic Loading And Photoredox-Driven Release Of Functional Cargo From Oligoviologen-Based Materials, Mark Steven Palmquist

Arts & Sciences Graduate Student Theses and Dissertations

In the pursuit of advanced functional materials that can perform well in next-generation applications, photoredox-enabled materials constructed to harness visible and near-infrared light to control release of cargo through the manipulation of electrostatic properties can fill a gap not presently occupied to a great extent in the field. Viologens possess redox and electrostatic properties that make them uniquely suited to serve well in this space when integrated into advanced materials including hydrogels and microparticles. The counteranions commonly associated with viologens, which are typically 4,4’-dialkyl bipyridinium salts, have long been used to take advantage of solubility, synthesis, and purification. These anions …

The Effect Of Ionization Density In Applications Of Radiation Detection, Dosimetry, And Therapy, Daniel Mulrow

Arts & Sciences Graduate Student Theses and Dissertations

This dissertation covers a wide range of topics but is linked by the common theme of radiation interacting with materials and studying the result of those interactions. The introduction describes the fundamentals of how radiation interacts with material and how we are able to detect that radiation and the application of how we use those interactions in radiation oncology. The thesis starts with a chapter detailing the temperature dependence of the photophysics in two organic scintillators. This chapter is the foundation for a future study that will look the degree to which these scintillators can distinguish between gammas and neutrons …

Spectro-Polarimetric And Time Domain Characteristics Of Dynamically Evolving Accretion Flows From The General Relativistic Raytracing Of General Relativistic Magneto-Hydrodynamical Simulations, Andrew West

Arts & Sciences Graduate Student Theses and Dissertations

Black holes are among the most exotic phenomena in our universe, physical objects so dense and compact that within their horizon not even light can escape. In binary systems, black holes can accrete material from their companion star, forming an accretion disk that is subjected to extreme physical conditions. Often, these disks are accompanied by jets - highly relativistic outflows of material moving at significant fractions of the speed of light. This extreme environment is the source of some of the most luminous and energetic processes in our universe. Black hole accretion disks are often modeled as a steady state, …

Essays On Statistical Inference, Nonconvex Optimization And Machine Learning, Yanjie Zhong

Arts & Sciences Graduate Student Theses and Dissertations

Over the past decades, numerous optimization and machine learning (ML) algorithms have been proposed, many of which have demonstrated success in real-world applications and significantly impacted people's lives. Researchers have devoted considerable effort to understanding the theoretical underpinnings of these methods and to improving their performance, as well as designing algorithms compatible with demanding real-world constraints. This dissertation focuses on investigating the statistical properties of several mainstream optimization and ML algorithms, enabling us to make decisions with statistical guarantees.First, we examine the classical stochastic gradient descent algorithm (SGD) in a general nonconvex context. Utilizing the multiplier bootstrap technique, we design …

Using In Situ Single-Particle Imaging To Understand The Role Of Structural Distortions During Anion Exchange In Cesium Lead Halide Perovskite Nanocrystals, Dongyan Zhang

Arts & Sciences Graduate Student Theses and Dissertations

Colloidal cesium lead halide (CsPbX3, X = Cl, Br, I) perovskite nanocrystals are being investigated as promising materials for light-emitting devices and fluorescence probes due to their strong absorption and emission (1.55 eV – 3.05 eV) of visible light. Anion exchange is a facile, post-synthetic method to tune the bandgap emission of CsPbX3 nanocrystals, covering most of the spectrum of visible light. However, structural heterogeneities in nanocrystals formed during anion exchange will lead to lower photoluminescence quantum yield and a broader range of emission wavelengths. A single batch of nanocrystals will contain a distribution of sizes, shapes, surface structures, and …

Abundances Of Ultra-Heavy Cosmic Ray Nuclei With Calet, Wolfgang Vaughn Zober

Arts & Sciences Graduate Student Theses and Dissertations

This work describes the determination of the relative abundances of the Galactic Cosmic-Ray (GCR) nuclei from Z=9 through Z=40, with preliminary measurements up to Z=44, using the Calorimetric Electron Telescope (CALET) on board the International Space Station (ISS). This analysis will compare results with the top-of-atmosphere abundances from the balloon-borne SuperTIGER and top-of-instrument abundances from the space missions, ACE-CRIS and HEAO-3. This analysis also provides insight into the potential opportunities and challenges for a future SuperTIGER-like mission on the ISS.Our analysis looks at work on two separate but complementary aspects of the Ultra-Heavy (UH) analysis in CALET. CALET has a …

A Stochastic Search For Intermittent Gravitational-Wave Backgrounds, Jessica Lawrence, Kevin Turbang, Andrew Matas, Arianna I. Renzini, Nick Van Remortel, Joseph D. Romano

Physics & Astronomy Faculty Publications

A likely source of a gravitational-wave background (GWB) in the frequency band of the Advanced LIGO, Virgo, and KAGRA detectors is the superposition of signals from the population of unresolvable stellar-mass binary-black-hole (BBH) mergers throughout the Universe. Since the duration of a BBH merger in band (similar to 1 s) is much shorter than the expected separation between neighboring mergers (similar to 103 s), the observed signal will be "popcornlike" or intermittent with duty cycles of order 10-3. However, the standard cross-correlation search for stochastic GWBs currently performed by the LIGO-Virgo-KAGRA Collaboration is based on a continuous-Gaussian signal model, which …

Diffusion Of Ionic Liquid-Modified Polymer Nanoparticles Through Nasal Mucus, Mary Vanlandingham

Honors Theses

Mucosal barriers are a natural defense system for preventing the entry of foreign objects into the body; however, they pose as obstacles for effective drug delivery. Coated polymer nanoparticles have been proven to possess improved rates of diffusion across mucus compared to their uncoated, or bare, counterparts. When choline-based ionic liquids (ILs) are introduced to an aqueous system, their dissociation leads to an increase in solution conductivity which ultimately reduces the viscosity of mucus without significantly affecting its structure. Additionally, ILs are highly tunable, so they work well in a range of pHs and conductivities, making ILs an ideal choice …

A Synthetic Approach To The Optimization Of Silicon-Rosindolizine Swir Fluorophores, Timothy Lewis

Honors Theses

Fluorophores emitting within the near-infrared (700 – 1000 nm) or shortwave-infrared (1000 – 1700 nm) regions of the electromagnetic spectrum are of particular interest for their potential to supplement or even outright replace commonly used biological imaging techniques, such as magnetic resonance imaging and computed tomography scanning. Various characteristics make these molecules particularly appealing to researchers, such as their ease of synthetic tunability, generally low toxicity, and high solubility in biological media in comparison to other NIR- and SWIR-emissive fluorophores. Different molecular skeletons have been examined for use as the core of these imaging agents, such as squaraine, cyanine, and …

Structural Integrity And Stability Of Dna In Ionic Liquid And Near-Infrared Indolizine Squaraine Dye, Ember Yeji Suh

Honors Theses

Luminol, the most common presumptive test for blood at a crime scene, has multiple issues, such as false positive results with chemical agents, no luminescence due to “active oxygen” cleaning agents on bloodstains, and inability to penetrate textile materials. A combination of indolizine squaraine dye and ionic liquid (IL), or Dye Enhanced Textile Emission for Crime Tracking (DETECT), have shown potential to address these issues. The purpose of this study was to assess the binding mechanism of CG (1:1) and SO₃SQ dye to HSA and how the mechanism can explain the W214 fluorescence quenching effect and to determine …

Chargex: Exploring State Switching Attack On Electric Vehicle Charging Systems, Ce Zhou, Qiben Yan, Zhiyuan Yu, Eshan Dixit, Ning Zhang, Huacheng Zeng, Alireza Safdari Ghanhdari

Computer Science Faculty Research & Creative Works

Electric Vehicle (EV) has become one of the promising solutions to the ever-evolving environmental and energy crisis. The key to the wide adoption of EVs is a pervasive charging infrastructure, composed of both private/home chargers and public/commercial charging stations. The security of EV charging, however, has not been thoroughly investigated. This paper investigates the communication mechanisms between the chargers and EVs and exposes the lack of protection on the authenticity in the SAE J1772 charging control protocol. To showcase our discoveries, we propose a new class of attacks, ChargeX, which aims to manipulate the charging states or charging rates of …

Aging An Ancient Maya Population From Actuncan, Belize Using Dental X-Rays, Kaitlyn Nicole Cash

Honors Theses

My goal is to determine an accurate age at death estimation of an ancient Maya population from the archaeological site of Actuncan, Belize. This was done by measuring the lengths of the coronal pulp cavities in the individuals’ teeth. I used X-Ray images to measure the coronal pulp cavities of the teeth and estimated age using multiple regression formulae for premolars, molars, and incisors to make age estimations. The formulae came from two studies, Ikeda et al. (1985) and Drusini (2008), that form the basis of my research. Ikeda et al. (1985) was the first to use this aging method, …

Microhydration Of Hexachlorophosphate Anion, Anna Robertson

Honors Theses

The microhydration of the hexafluorophosphate anion has been the focus of many previous experimental and computational studies, due to its use in room temperature ionic liquids.This preliminary study examines the analogous hexachlorophosphate anion and its interactions with one to two water molecules (PCl₆⁻(H₂O)_n, n = 1-2), identifying the structural and energetic differences in the microhydration of PCl₆⁻ versus PF₆⁻. A systematic investigation of the possible orientations of one to two water molecules around PCl₆⁻ was done. Full geometry optimizations were performed using the ab initio method …

A Study Of Data/Monte Carlo Agreement In Charmed Baryon Decays At Belle Ii, Kaitlyn Thurmond

Honors Theses

The Belle II experiment at the SuperKEKB electron-positron accelerator facility in Tsukuba, Japan has a primary goal of searching for new physics beyond the Standard Model of particle physics. Extremely precise measurements of particle decays will be compared with Standard Model predictions in order to expose the presence of new particles and interactions. These measurements are prepared using simulated samples to avoid potential biases when studying the data. The Belle II collaboration produces two types of simulated samples for this purpose. One is produced with consistent calibration payloads and another with payloads calibrated as a function of data taking. This …

Investigating Reactivity Of Artificial Copper Peptides With Small Molecules, Allyson Bryant

Honors Theses

The design of artificial enzymes has been a topic of significant interest in the field of biochemistry, as they can provide new opportunities for catalytic processes and drug development. De novo protein design has emerged as a promising approach to create such enzymes, and the study of metalloproteins, particularly copper-binding peptides, has become a focus of this research. This thesis investigates the reactivity of a mutated copper-binding peptide, I5A-3SCC, with oxygen and its implications in the development of artificial enzymes.

The parent peptide, 3SCC, was mutated by replacing Isoleucine residues with smaller Alanine side chains, which was hypothesized to enhance …

A Camera Trap Study Of Scavenger Species On The University Of Mississippi Campus, Lise Larsen

Honors Theses

This is a camera trap study to understand what kind of mammalian scavenger community we have on the University of Mississippi campus and where they are most prominent. Three motion-triggered cameras were used to survey ten buildings on campus over ten weeks. A low number of individuals were caught on camera during this study. There were limitations on this study such as a low number of cameras and a short span of time. More research needs to be done to understand the scavenger community on this campus.

Photophysical And Photochemical Processes In Small Molecules And Materials For Solar Energy Conversion, Ethan Lambert

Honors Theses

The work covered in this thesis all falls under the theme of photophysical processes after light and matter interact. Those of primary interest are Raman scattering induced vibrations and excited state dynamics probed by transient absorption spectroscopy. Small molecules are studied with Raman spectroscopy and computational chemistry. These studies unearth the shifts in vibrational frequency as a function of charge transfer or receipt and how a quantitative assay of natural orbital populations and delocalization can offer both the nature and magnitude of this charge transfer. Further, a method is presented that builds upon previous work within the academic family tree; …

Photocatalyzed Hydrogen Evolution Using Nickel-Bound Metallothionein Protein, Windfield Swetman

Honors Theses

The continued burning of fossil fuels is not only a cause of increasing deterioration of the environment but also a financially unsustainable source of energy. Advances in energy production must be investigated to avoid the long-term effects of this current main source of energy. One of the avenues being explored is the use of metalloenzymes to catalyze hydrogen evolution via water splitting that occurs during the reductive half of artificial photosynthesis. Metalloenzyme catalysts with a single Ni(Cys)₄ active site have been previously studied, and this study explores the possibility of increasing hydrogen production by using metalloenzyme catalysts with multiple …

An Empirical Study Of Pre-Trained Model Reuse In The Hugging Face Deep Learning Model Registry, Wenxin Jiang, Nicholas Synovic, Matt Hyattt, Taylor R. Schorlemmer, Rohan Sethi, Yung-Hisang Lu, George K. Thiruvathukal, James C. Davis

Computer Science: Faculty Publications and Other Works

Deep Neural Networks (DNNs) are being adopted as components in software systems. Creating and specializing DNNs from scratch has grown increasingly difficult as state-of-the-art architectures grow more complex. Following the path of traditional software engineering, machine learning engineers have begun to reuse large-scale pre-trained models (PTMs) and fine-tune these models for downstream tasks. Prior works have studied reuse practices for traditional software packages to guide software engineers towards better package maintenance and dependency management. We lack a similar foundation of knowledge to guide behaviors in pre-trained model ecosystems.

In this work, we present the first empirical investigation of PTM reuse. …

Feature Selection From Clinical Surveys Using Semantic Textual Similarity, Benjamin Warner

McKelvey School of Engineering Graduate Student Theses & Dissertations

Survey data collected from human subjects can contain a high number of features while having a comparatively low quantity of examples. Machine learning models that attempt to predict outcomes from survey data under these conditions can overfit and result in poor generalizability. One remedy to this issue is feature selection, which attempts to select an optimal subset of features to learn upon. A relatively unexplored source of information in the feature selection process is the usage of textual names of features, which may be semantically indicative of which features are relevant to a target outcome. The relationships between feature names …

The Affective Landscapes Of Herbalism In New Mexico, Samantha Angelou Stroud

Geography ETDs

Herbalism, or practices which use plants for medicinal purposes, is tied to traditions in several cultures of the American Southwest, including Indigenous herbal medicine, Mexican-American curanderismo, and Western herbal traditions. Herbalism has been steadily gaining mainstream popularity since the late 1960s, alongside counterculture, holistic health, and back-to-nature movements, introducing many newcomers to the practice. This study asks: How does herbalism create and attach meaning to plants, cultures, and place in New Mexico? What are the affective landscapes produced by herbalism in New Mexico? And, to what extent do meaningful attachments manifest in ethics and actions of care? I argue that …

Deep Learning Applications For Secondary Cosmic Microwave Background Anisotropies, Eric Guzman

Physics Theses and Dissertations

Next-generation cosmic microwave background (CMB) surveys will map the microwave sky with unprecedented precision presenting a wide range of opportunities for new insights into cosmology. To maximize the scientific value of upcoming surveys, new methods that can disentangle primary and secondary CMB anisotropies are required. The CMB secondaries encode information about the cosmological sources that cause them and act as a source of noise in the observation of primary anisotropies. Quadratic estimators are the current standard techniques for reconstruction of the sources of CMB secondaries. While successful for reconstruction of distortion fields with current data, quadratic estimators will become sub-optimal …

Photonic Sensors Based On Integrated Ring Resonators, Jaime Da Silva

Mechanical Engineering Research Theses and Dissertations

This thesis investigates the application of integrated ring resonators to different sensing applications. The sensors proposed here rely on the principle of optical whispering gallery mode (WGM) resonance shifts of the resonators. Three distinct sensing applications are investigated to demonstrate the concept: a photonic seismometer, an evanescent field sensor, and a zero-drift Doppler velocimeter. These concepts can be helpful in developing lightweight, compact, and highly sensitive sensors. Successful implementation of these sensors could potentially address sensing requirements for both space and Earth-bound applications. The feasibility of this class of sensors is assessed for seismic, proximity, and vibrational measurements.

New Methods For Core-Hole Spectroscopy Based On Coupled Cluster Theory, Megan Simons

Chemistry Theses and Dissertations

X-ray absorption spectra (XAS) is a method used to investigate atomic local structure and electronic states. Coupled cluster method is a numerical method used for describing many-body systems and electron correlation in a wavefunction. When equation-of-motion coupled cluster is used in XAS calculations, the ground state is applied to the excitation operator, which excites or ionizes the electron. This causes a large orbital relaxation error, normally ~5 eV, which leads to the need for triple excitations in order to obtain accurate results.

This dissertation introduces a coupled cluster method that uses "transition potential" reference orbitals to reduce the orbital relaxation …

Optimizing Tumor Xenograft Experiments Using Bayesian Linear And Nonlinear Mixed Modelling And Reinforcement Learning, Mary Lena Bleile

Statistical Science Theses and Dissertations

Tumor xenograft experiments are a popular tool of cancer biology research. In a typical such experiment, one implants a set of animals with an aliquot of the human tumor of interest, applies various treatments of interest, and observes the subsequent response. Efficient analysis of the data from these experiments is therefore of utmost importance. This dissertation proposes three methods for optimizing cancer treatment and data analysis in the tumor xenograft context. The first of these is applicable to tumor xenograft experiments in general, and the second two seek to optimize the combination of radiotherapy with immunotherapy in the tumor xenograft …

Development Of Bayesian Hierarchical Methods Involving Meta-Analysis, Jackson Barth

Statistical Science Theses and Dissertations

When conducting statistical analysis in the Bayesian paradigm, the most critical decision made by the researcher is the identification of a prior distribution for a parameter. Despite the mathematical soundness of the Bayesian approach, a wrongly specified prior can lead to biased and incorrect results. To avoid this, prior distributions should be based on real data, which are easily accessible in the "big data" era. This dissertation explores two applications of Bayesian hierarchical modelling that incorporate information obtained from a meta-analysis.

The first of these applications is in the normalization of genomics data, specifically for nanostring nCounter datasets. A meta-analysis …

Empirical Likelihood Ratio Tests For Homogeneity Of Distributions Of Component Lifetimes From System Lifetime Data With Known System Structures, Jingjing Qu

Statistical Science Theses and Dissertations

In system reliability, practitioners may be interested in testing the homogeneity of the component lifetime distributions based on system lifetimes from multiple data sources for various reasons, such as identifying the component supplier that provides the most reliable components.

In the first part of the dissertation, we develop distribution-free hypothesis testing procedures for the homogeneity of the component lifetime distributions based on system lifetime data when the system structures are known. Several nonparametric testing statistics based on the empirical likelihood method are proposed for testing the homogeneity of two or more component lifetime distributions. The computational approaches to obtain the …

Effect Of Graphene-Based Fillers On The Properties Of Sunflower-Based Polyurethane, Vishwa Suthar

Electronic Theses & Dissertations

Polyurethane market majorly depends on synthetic materials which are noxious. This stimulated an idea to replace petrochemical resources with renewable resources for polyurethane production. Keeping this in mind, this research focused on the use of sunflower oil for the preparation of polyol and its use in polyurethane composition. The reaction mechanism of epoxidation and ring-opening was approached for the conversion of sunflower oil to polyol. During the conversion of sunflower oil, unsaturated groups of sunflower oil were converted into hydroxyl groups of polyol.

Sunflower oil-based polyol was successfully blended with methylene diphenyl diisocyanate (MDI) to form urethane bonds. Confirmative tests …

Visualized Algorithm Engineering On Two Graph Partitioning Problems, Zizhen Chen

Computer Science and Engineering Theses and Dissertations

Concepts of graph theory are frequently used by computer scientists as abstractions when modeling a problem. Partitioning a graph (or a network) into smaller parts is one of the fundamental algorithmic operations that plays a key role in classifying and clustering. Since the early 1970s, graph partitioning rapidly expanded for applications in wide areas. It applies in both engineering applications, as well as research. Current technology generates massive data (“Big Data”) from business interactions and social exchanges, so high-performance algorithms of partitioning graphs are a critical need.

This dissertation presents engineering models for two graph partitioning problems arising from completely …

Landslide Forecast In Taiwan Based On Machine Learning In The Gis Field, Yi Shen

Honors Capstones

Landslides can pose a significant risk to life, property, and infrastructure in mountainous regions, and can be triggered by various factors, including intense rainfall, earthquakes, and water level changes. Machine learning is commonly used to forecast landslides, based on statistical relationships between past landslides and multiple variables to create a general forecasting model. However, these models often require large amounts of data to achieve accurate results. This project aims to use only a few variables but take advantage of both their spatial distribution and temporal trends to improve the accuracy of landslide forecasts. This approach is tested in Taiwan, a …