Physical Sciences and Mathematics Commons^™

Super P-Sulfur Cathodes For Quasi-Solid-State Lithium-Sulfur-Batteries., Milinda Bharatha Kalutara Koralalage

Electronic Theses and Dissertations

Lithium-Sulfur (Li-S) batteries have become a promising candidate to meet the current energy storage demand, with its natural abundance of materials, high theoretical capacity of 1672 mAhg-1, high energy density of 2600 Whkg-1, low cost and lower environmental impact. Sulfide based solid state electrolytes (SSEs) have received greater attention due to their higher ionic conductivity, compatible interface with sulfur-based cathodes, and lower grain boundary resistance. However, the interface between SSEs and cathodes has become a challenge in all solid-state Li-S batteries due to the rigidity of the participating surfaces. A hybrid electrolyte containing SSE coupled with a small amount of …

More Than Meets The Eye: In-Store Retail Experiences With Augmented Reality Smart Glasses, Pauline Pfeifer, Tim Hilken, Jonas Heller, Saifeddin Alimamy, Roberta Di Palma

All Works

Augmented reality smart glasses (ARSGs) promise to enhance consumer experiences and decision-making when deployed as in-store retail technologies. However, research to date has not studied in-store use cases; instead, it has focused primarily on consumers' potential adoption of these devices for everyday use. Nor have prior studies compared ARSG uses with the now-common use of AR on touchscreen devices. The current research addresses these knowledge gaps by examining whether ARSGs outperform AR on touchscreen devices in the context of in-store retail experiences. Testing with an actual retail application (n = 308) shows that ARSGs are superior to AR on touchscreen …

Enhancing Health Tweet Classification: An Evaluation Of Transformer-Based Models For Comprehensive Analysis, Foram Pankajbhai Patel

Computer Science and Engineering Theses

The task of health tweet classification entails identifying whether a given tweet is health-related or not. While existing research in this area has made significant progress in classifying tweets into specific sub-domains of health, such as mental health, COVID-19, or specific diseases, there is a need for a more comprehensive approach that considers a broader range of health-related topics. This thesis addresses this need by proposing a diverse and comprehensive dataset that includes various existing health-related datasets, data collected through a keyword-based approach, and manually annotated data. However, the use of health-related keywords in a figurative or non-health context poses …

Context-Aware Gaze-Based Interface For Smart Wheelchair, Tien Pham

Computer Science and Engineering Theses

Human-Computer Interfaces (HCI) is an essential aspect of modern technology that has revolutionized the way we interact with machines. With the revolution of computers and smart devices and the advent of autonomous vehicles and other machines, there has been a significant advancement in this area that brings convenience to users to interact with technology intuitively and efficiently. However, the importance of HCI goes beyond the convenience of everyday technology. It has become crucial in the development of assistive technologies that empower people with disabilities to live more independently. Person with disabilities, who lack control of one or more parts of …

Emauth: A Usable Continuous Authentication Scheme, Vighnesh Sivaraman

Computer Science and Engineering Theses

ABSTRACT: In recent years, wearables have become an integral part of daily life for most users. Wearables provide a seamless supplement to their main counterparts such as smartphones, and tablets. With the increasing prevalence of smart devices in a ubiquitous manner, protecting data has become a crucial aspect of security in all areas of life, as individuals can be vulnerable to such threats regardless of their location. As a security measure, authentication measures have been adopted. Traditional/ Legacy Authentication mechanisms such as TouchID, FaceID, and Password/PIN are incorporated into the everyday life of users. There also exists another mode of …

Toward A Deeper Integration Of Low-Fidelity Sketches Into Mobile Application Development, Soumik Mohian

Computer Science and Engineering Dissertations

Mobile application development often starts with creating low-fidelity sketches of user interfaces. Integrating these sketches into the software development process can reduce repetition, narrow the gap between user perception and final implementation, and improve app resilience. In this study, we introduce the DoodleUINet dataset, which comprises over 10K sketches of UI elements. Our Doodle2App tool converts low-fidelity sketches into a single-page, compilable Android app. At the same time, our PSDoodle provides an interactive, partial sketch-based search engine with a top-10 screen retrieval accuracy comparable to the state-of-the-art SWIRE line of work but with a 50% reduction in the average required …

Universal Back-End Design, Jason Kalili

LMU/LLS Theses and Dissertations

Accessibility in back-end development is often overlooked, with the majority of discussions and efforts centered on front-end design. To make applications usable for a wider audience, developers must also prioritize incorporating accessibility from the back-end. Back-end web accessibility encompasses the design and development of web-based systems and applications that are accessible to all users, including those with disabilities. This involves optimizing the underlying code and infrastructure for accessibility and implementing features that enable users with disabilities to navigate and interact with the site or application. Ensuring back-end web accessibility is crucial for creating an inclusive online environment accessible to everyone, …

Optimizing Resource Utilization, Efficiency And Scalability In Deep Learning Systems, Xiaofeng Wu

Computer Science and Engineering Dissertations

This thesis addresses the challenges of utilization, efficiency, and scalability faced by deep learning systems, which are essential for high-performance training and serving of deep learning models. Deep learning systems play a critical role in developing accurate and complex models for various applications, including image recognition, natural language understanding, and speech recognition. This research focuses on understanding and developing deep learning systems that encompass data preprocessing, resource management, multi-tenancy, and distributed model training. The thesis proposes several solutions to improve the performance, scalability, and efficiency of deep learning applications. Firstly, we introduce SwitchFlow, a scheduling framework that addresses the limitations …

Multi-Objective Optimization Framework For Electrified Vehicle Penetration Based On Life Cycle Assessment And Life Cycle Cost., Eva Alondra Diaz Lozano

Open Access Theses & Dissertations

This research proposed a novel framework for creating optimal transportation scenarios that consider multiple objectives such as minimum greenhouse gas emissions, air pollutant levels, and cost of ownership. The thesis approach is a multi-objective evolutionary algorithm coupled with the AFEET tool, allowing us to efficiently explore the complex trade-offs between these objectives and identify a diverse set of optimal solutions. Through several case studies and a design of experiments, this demonstrates the effectiveness and practicality in different scenarios. This approach has significant implications for policymakers and industry professionals seeking to make sustainable and cost-effective decisions in the transportation sector.

Elizabeth River Basin Environmental Justice Indicators, Molly Mitchell, Andrew M. Scheld, Sarah Stafford, Tamia Rudnicky, Joseph Snitzer

Data

This data is a portion of the data included in the Elizabeth River Environmental Justice Tool (https://cmap22.vims.edu/EREJTool/) The Elizabeth River Environmental Justice map viewer contains a variety of layers that will help planners target vulnerable locations and populations within the Elizabeth River Watershed. This data was developed specifically to support the Elizabeth River Project’s decision making in this region.

Mach And Froude Numbers On Mars., Camella-Rosa Nasr

Electronic Theses and Dissertations

Mars atmospheric global circulation models exhibit transonic jet streaks during
northern winter, which motivates this study of the Mach number, Ma (the ratio of
flow speed to the speed of sound), and the Froude number, Fr (the ratio of flow
speed to the speed of buoyancy waves), as a function of season and location. Two
global reanalyses spanning Mars Years (MY) 24 to 33 are used as input, EMARS
and OpenMARS. The study’s vertical coordinate is the isentropic variable potential
temperature, θ, ranging from θ = 125 to 1100 K, which corresponds to altitudes
ranging on average from z ≈ …

Structural, Magnetic, Electrical, Pseudocapacitive, And Electrocatalytic Properties Of Bilayered Ruddlesden-Popper Oxides., Chandana Kananke-Gamage

Electronic Theses and Dissertations

Ruddlesden Popper (RP) oxides are perovskite-derived functional materials with the general formula An-1Aʹ2BnO3n+1, where A/Aʹ is often a lanthanide or alkaline earth metal, and B is usually a transition metal. These materials contain perovskite-like connectivity, where BO6 units share apexes to form layers that are stacked above each other. The number of layers in each stack is represented by n in the above formula. The spaces between stacks are often occupied by lanthanide or alkaline-earth metals (Aʹ-site metals), which also reside in intra-stack spaces (A-site) between the octahedra. Oxide materials derived from perovskites have been studied for a wide range …

Mechanism And Kinetics Of Photocatalytic Partial Oxidation Of Methane On Single Site Mox Reaction Centers., Clint Evrard

Electronic Theses and Dissertations

Single-site transition-metal doped photocatalysts are a class of materials in which small transition-metal oxide clusters are embedded onto the surface of zeolites, graphene, and bulk semiconductors. Experimental findings demonstrate that VO4, CrO4, NbO4, and WO4 clusters embedded on an MCM- 41 mesoporous amorphous SiO2 are effective photocatalysts for oxidative reactions. The selective direct partial oxidation of methane (POM) to form methanol is essential for efficiently utilizing natural gas. Photocatalytic methane oxidation has advantages over traditional thermal catalysis as it can be deployed at small-scale facilities to reduce methane release into the atmosphere due to flaring potentially. Our work has aimed …

The Study Of Corrosion On Additive-Manufactured Metals., Braydan Daniels

Electronic Theses and Dissertations

The purpose of this study was to investigate and compare the corrosion mechanisms between wrought and additive-manufactured (3D-printed) copper and stainless steel. The experimental procedure consisted of measuring the open circuit potential, electrochemical impedance spectroscopy, linear sweep voltammetry, Tafel analysis, surface topology, and scanning electron microscopy for each metal within salt water, tap water, sulfuric acid, and synthetic body fluid (excluding copper in synthetic body fluid).

Overall, printed stainless steel was more corrosion-resistant than wrought stainless steel in tap water and synthetic body fluid based on OCP, LSV, and surface topology results. Additionally, printed copper was more corrosion-resistant than wrought …

A Monte Carlo Analysis Of Nonprobability Sampling & Post Hoc Corrections, Julia Hong

Masters Theses & Specialist Projects

Nonprobability samples are often used in place of probability samples because the former are less trouble and less expensive. Unfortunately, it is difficult to determine how well a sample represents population parameters when using nonprobability samples. Researchers attempt to mitigate the disadvantages of nonprobability sampling by performing post hoc corrections, but this adjustment may not successfully undo the effects of nonprobability sampling. To examine these effects, a Monte Carlo simulation was conducted to create a pseudo-population from which samples were drawn. Forty-one conditions were replicated 10,000 times each, with each sample consisting of 100 observations. A post-stratification adjustment was made …

Subterraneans: A Regional Earth Dwelling For Comfort And Beauty, Isaak Benchoff

Architecture Undergraduate Honors Theses

Subterraneans is a study of an affordable, self-sufficient, sustainable, and dignified housing prototype for the region of Northwest Arkansas. It is a design process investigation based on the ideas of turning a local, sustainable material into affordable homes that can be built within a community of people sharing land and resources. The homes would utilize as many natural materials as possible to minimize the impact on the Earth and the cost to the owners.

Research looked at many different vernacular building precedents as well as the work done by contemporary design firms in the area of economical, low-impact, and passively …

Impacts Of Preferential Flow On Tc-99and Np-237 Vadose Transport In Soils At The Savannah River Site, Josh Parris

All Theses

Since the 1950s, the United States has produced approximately 90,000 metric tons of spent nuclear fuel (SNF) (Office of Nuclear Energy, 2022); however, no long-term storage solutions are available. Technecium-99 and neptunium-237, two fission products found in SNF, readily form highly mobile species in oxidizing conditions (Hu, 2008; Bondietti, 1979) and have respective half-lives of 2.13 x 10⁵ and 2.14 x10⁶ years (Hu, 2010). Considering these characteristics, ⁹⁹Tc and ²³⁷Np are two risk-driving isotopes found in SNF storage. The process of macropore-facilitated preferential flow, transport through cracks within a soil matrix, has been recognized to increase …

A Natural Resource Management Plan For The Historic Ramsey House, Brianna Saylor, Cole Oakey, Devin Hevener, Everett Williams, Haley Cox, Rachel Carpenter

Chancellor’s Honors Program Projects

No abstract provided.

Anxiety-Like Behavior In C57bl/6j Mice Is Sexually Dimorphic And Altered By Buprenorphine, Ohm Sharma

Chancellor’s Honors Program Projects

No abstract provided.

Supramolecular Pi-Donor/Acceptor Arrays Based On Redox-Active Metal-Organic Coordination Assemblies, Paola Benavides

All Dissertations

Coordination-driven self-assembly is an attractive strategy for constructing thermodynamically stable supramolecular coordination complexes, ranging from discrete metallacycles and cages to infinite coordination polymers and metal-organic frameworks for a variety of applications.

Chapter 1 discusses strategies for preparing supramolecular charge-transfer π-donor/acceptor assemblies and their potential applications.

Chapter 2 demonstrates that tricomponent self-assembly method, which was believed to yield 3D-cages, based on tetrapyridyl porphyrin (M’TPP, M’ = Zn or H₂), dicarboxylate ligands (XDC), and caped cis-Pt(II) corners, actually yields 2D-bowties featuring an M’TPP core and two parallel XDC linkers held together by four heteroligated PtII(N,O) corners. The 2D-bowties showed …

Advancing Iot Security Through Blockchain-Based Decentralized Platform And Ai-Powered Digital Forensics, Ruipeng Zhang

Masters Theses and Doctoral Dissertations

The proliferation of Internet of Things (IoT) devices, from smartphones, smart thermostats to smart home security systems, is revolutionizing our society and daily lives. However, it also has posed significant challenges to IoT security and forensics. To tackle those challenges, innovative solutions are designed to enhancing IoT security and accelerating investigation of cybersecurity incidents by leveraging recent technological advancements in Blockchain and Artificial Intelligence (AI). First, an IoT service platform, called DISP, is proposed to improve the security and interoperability of IoT systems. DISP utilizes the consortium blockchain technology to transform centralized, insecure IoT communications into decentralized, secure, and traceable …

Gaslight: Attacking Hard-Label Black-Box Classifiers Via Deep Reinforcement Learning, Rajat Sethi

All Theses

Through artificial intelligence, algorithms can classify arrays of data, such as images or videos, into a predefined set of categories. With enough labeled data, a classifier can analyze an input’s components and calculate confidence scores for each category. However, machine learning relies heavily on approximation, which allows attackers to exploit classifiers by providing adversarial
examples. Specifically, attackers can modify their input so that the victim classifier cannot correctly label it, while a human observer would be unable to notice the difference.
This thesis proposes Gaslight, a system that uses deep reinforcement learning to generate adversarial examples against a victim classifier. …

Apparatus And Instrumentation Design For Investigation Of Surface Impact Effects On Superconductivity, Austin Back

All Theses

The effects of ion irradiation on the physical properties of materials make EBITs an invaluable tool for many scientific and engineering fields. Many experiments rely on the use of these lab setups to test for device reliability, explore surface physics phenomena, and replicate the environment for many physical systems that are not readily accessible. We seek to extend the capabilities of these experiments using the CUEBIT and a new sample holder installed in section 3.

This thesis begins by presenting an overview of the CUEBIT and the basic operations of the equipment. This is followed by a brief explanation of …

Quantifying Heterogeneity Along A Hillslope Using Seismic Refraction, Structure From Motion, And X-Ray Fluorescence In The Piedmont, South Carolina, Leah Topping

All Theses

The critical zone (CZ) is the life sustaining outer layer of the earth that spans from the top of unweathered bedrock to the tops of the trees. This dynamic zone is always evolving because a variety of chemical, physical, and biological processes transform bedrock into regolith, creating a spatially heterogeneous CZ architecture. This study aims to investigate the relationships between regolith thickness, seismic velocities, and chemical profiles as a function of slope position and it is hypothesized bedrock composition, fracture density, and foliation are the key factors controlling the physical heterogeneity in the top 1-2 meters of the CZ. To …

Iot Health Devices: Exploring Security Risks In The Connected Landscape, Abasi-Amefon Obot Affia, Hilary Finch, Woosub Jung, Issah Abubakari Samori, Lucas Potter, Xavier-Lewis Palmer

School of Cybersecurity Faculty Publications

The concept of the Internet of Things (IoT) spans decades, and the same can be said for its inclusion in healthcare. The IoT is an attractive target in medicine; it offers considerable potential in expanding care. However, the application of the IoT in healthcare is fraught with an array of challenges, and also, through it, numerous vulnerabilities that translate to wider attack surfaces and deeper degrees of damage possible to both consumers and their confidence within health systems, as a result of patient-specific data being available to access. Further, when IoT health devices (IoTHDs) are developed, a diverse range of …

Separating The R Vs. S Enantiomers Of A Quinoline Aimed At Inhibiting The Allosteric Binding Pocket Of Hiv-1 Integrase, Madison Canfield

Honors Theses

HIV-1 is a retroviral disease that infects CD4+ T cells in the body. Once inside the body, HIV-1 uses human cell machinery to replicate and reproduce using several enzymes to reverse transcribe viral RNA to DNA and integrate the viral DNA into the human genome to reproduce. Several drugs, such as NRTIs, INSTIs, NNRTIs, and PIs, have been created to inhibit specific parts of the viral life cycle and are used in combination to fight HIV-1. However, these medications face challenges of viral mutation and resistance, which increases the importance of creating more potent and effective drugs. Recently, a new …

Unsupervised Dimension Reduction Techniques For Lung Diagnosis Using Radiomics, Janet Kireta

Electronic Theses and Dissertations

Over the years, cancer has increasingly become a global health problem [12]. For successful treatment, early detection and diagnosis is critical. Radiomics is the use of CT, PET, MRI or Ultrasound imaging as input data, extracting features from image-based data, and then using machine learning for quantitative analysis and disease prediction [23, 14, 19, 1]. Feature reduction is critical as most quantitative features can have unnecessary redundant characteristics. The objective of this research is to use machine learning techniques in reducing the number of dimensions, thereby rendering the data manageable. Radiomics steps include Imaging, segmentation, feature extraction, and analysis. For …

Evaluating Bulk Carbon And Nitrogen Isotope Compositions Of Acidic Hydrothermal Sediments On Earth– Implications For Mars Astrobiology, Chance Sturrup

Masters Theses

Carbon isotopes have been widely used as unique biosignatures because biologic processes commonly result in distinctive negative delta ¹³C values (-35 to -10 ‰) within organic material on Earth. However, the bulk delta ¹³C analysis in Gale crater sediments on Mars revealed a wider range of values, from -25 to +56 ‰ (Franz et al., 2020), which suggests a more complex origin. To determine if bulk isotope analysis can be successfully used to detect a microbial signature in a martian analog environment, we analyzed concentrations and isotope compositions of C within hydrothermal sediments in Iceland (Námafjall, Krýsuvík, Hveragerdi) …

The Effect Of Advection On The Three Dimensional Distribution Of Turbulent Kinetic Energy And Its Generation In Idealized Tropical Cyclone Simulations, Joshua B. Wadler, David S. Nolan, Jun A. Zhang, Lynn K. Shay, Joseph B. Olsen, Joseph J. Cione

Publications

The distribution of turbulent kinetic energy (TKE) and its budget terms is estimated in simulated tropical cyclones (TCs) of various intensities. Each simulated TC is subject to storm motion, wind shear, and oceanic coupling. Different storm intensities are achieved through different ocean profiles in the model initialization. For each oceanic profile, the atmospheric simulations are performed with and without TKE advection. In all simulations, the TKE is maximized at low levels (i.e., below 1 km) and ∼0.5 km radially inward of the azimuthal-mean radius of maximum wind speed at 1-km height. As in a previous study, the axisymmetric TKE decreases …

Divergence-Conforming Velocity And Vorticity Approximations For Incompressible Fluids Obtained With Minimal Facet Coupling, Jay Gopalakrishnan, Lukas Kogler, Philip L. Lederer, Joachim Schöberl

Mathematics and Statistics Faculty Publications and Presentations

We introduce two new lowest order methods, a mixed method, and a hybrid discontinuous Galerkin method, for the approximation of incompressible flows. Both methods use divergence-conforming linear Brezzi–Douglas–Marini space for approximating the velocity and the lowest order Raviart–Thomas space for approximating the vorticity. Our methods are based on the physically correct viscous stress tensor of the fluid, involving the symmetric gradient of velocity (rather than the gradient), provide exactly divergence-free discrete velocity solutions, and optimal error estimates that are also pressure robust. We explain how the methods are constructed using the minimal number of coupling degrees of freedom per facet. …