Digital Commons Network^™

Mechanical Properties And Microstructural Characteristics Of Hydrated Bcsa Cement At Extreme Temperatures, Behzad Farivar

Graduate Theses and Dissertations

Belitic Calcium Sulfoaluminate (BCSA) cement is an alternative binder known for its rapid setting and high early strength, making it ideal for applications such as fast-track construction and repair. This study presents a comprehensive investigation into the behavior of BCSA cement under a wide range of curing temperatures, with emphasis on early-age strength development, admixture effects, and the use of the maturity method for strength prediction.

The research evaluates BCSA cement performance in both hot and cold environments, ranging from approximately -28.9 °C (-20°F) to 49 °C (120°F). In warm climates, citric acid was used as a set retarder to …

Exploration Of Polymorphic Gate-Based Watermarking In Asynchronous Circuits, Stephanie Stock

Graduate Theses and Dissertations

With the increasing demand for new state-of-the-art integrated circuits (ICs), intellectual property (IP) reuse has become more commonplace to both accelerate the design process and lessen the non-recurring engineering costs of a design. Reuseable IP poses significant security risks, not only to the creator of the IP, but also to the consumer purchasing the IP. For an IP vendor, this risk can come from illegal distribution, cloning, or overuse. For the purchaser, counterfeit IPs may be purchased from an unvetted vendor, leading to a substandard design, malfunctions, IP infringement, or security vulnerabilities. Hardware watermarking is a method to protect designers …

Experimental Study Of Novel Bcsa Scc Repair Materials And Implications On Corrosion In Bcsa Concrete Structures, Elizabeth S.M. Poblete

Graduate Theses and Dissertations

Some current building codes for structural concrete allow the use of alternative cement concrete if their structural, durability, and fire performance can be shown to be comparable to portland cement (PC) concrete. One such alternative cement, belitic calcium sulfoaluminate (BCSA) cement, is a promising standalone replacement for portland cement given its lower global warming potential (GWP), fast setting time, and high early age compressive strength. These properties also make it an ideal repair material. But repair materials often need to be highly flowable and easy to consolidate and their performance when used to repair PC concrete structures must be understood. …

Measuring Agricultural Adaptation Using Remote Sensing: A Study Of Pigeonpea In Malawi, Maria Gorret Nabuwembo

Graduate Theses and Dissertations

Drought, heatwaves, and flooding cause tremendous damage to agricultural production in Malawi, and the continuous production of maize has led to widespread soil degradation. Additionally, climate change is transforming the environment at a scale beyond historical records, posing significant challenges to social, political, and economic systems. To combat these issues, agricultural innovations have been implemented, such as the installation of irrigation systems and development of heat/drought resilient crop varieties. Pigeonpea is one of the prominent drought-tolerant and temperature resilient crops grown as a diversification strategy since it allows farmers to adapt to changes while maintaining subsistence needs. This research investigates …

Leveraging Natural Variation In Yeast To Understand Susceptibility Differences In Parkinson’S Disease, Julio Andres Molina Pineda

Graduate Theses and Dissertations

Parkinson’s Disease (PD) is a neurodegenerative disorder that causes countless suffering around the world. Both forms, familial and sporadic, have been associated with the misfolding and cytotoxicity of α-synuclein, an otherwise non-pathogenic protein suspected to have various roles in the normal maintenance of the central nervous system. Model organisms have emerged as great vessels to uncover the cellular and molecular mechanisms that shape α-syn biology, and great strides have been made to understand it. Yet, it is still unclear why some individuals are affected by α-syn toxicity, while others not so much. Since it’s extremely complicated to study and probe …

Constraining Neutron Star Kicks Through Gravitational Wave Detection, James Phillips

Graduate Theses and Dissertations

Neutron stars have, on average, much higher proper motions than those of hot and bright O and B type main sequence stars. Thus, it is widely suspected that asymmetries in core-collapse supernovae provide a substantial kick to these compact objects at birth. Gen- eral Relativity predicts that such supernova asymmetries will generate bursts of gravitational radiation, though no such burst has been yet detected. Here we argue that the polarization amplitudes of those gravitational waves can be used to calculate the kicks imparted on that nascent neutron star. We begin by reviewing the evidence for natal kicks, then we describe …

The American Lowrider As A Form Of Art, Chad Johnson

Graduate Theses and Dissertations

This paper argues that lowriders, a style of heavily customized vehicle deeply rooted in Chicano culture, ought to be recognized as a legitimate American art form. After establishing the historical and cultural background of lowriders, this paper identifies a cluster of essential aesthetic features which define lowriders, such as lowered suspension, custom wheels, elaborate paintwork, and opulent interiors. Several paradigmatic lowriders exhibiting these features are then examined against the background of various philosophical definitions of art. The analysis demonstrates that lowriders with their elaborate body modifications and paintwork do align with the essentialist views such as Clive Bell’s formalism and …

Survival Signature Estimation For All-Terminal Networks By Solving The Multi-Objective Bottleneck Spanning Tree Problem, Dewan Maisha Zaman

Graduate Theses and Dissertations

This research examines the problem of estimating the survival signature of all-terminal networks using Monte Carlo (MC) simulation. Following a recent similar result for twoterminal networks, we show that the work required within each MC replication corresponds to solving a multi-objective bottleneck spanning tree (MOBST) problem. We implement the resulting MC procedure using a “Blocks” algorithm from the literature to solve the MOBST in each replication by identifying its minimal set of non-dominated points. We compare this implementation against intuitive benchmark procedures for completing the work within an MC replication. We conduct numerical experiments to assess the efficacy of multi-objective …

Comparison Of Rt-Qpcr And Rt-Ddpcr On Assessing Model Virus In Wastewater, Wafa Youssfi

Graduate Theses and Dissertations

There is an increasing demand for quantifying viral loads in diverse wastewater systems using polymerase chain reaction (PCR). This study evaluates the performance of two commonly used workflows: reverse transcription quantitative PCR (RT-qPCR) and reverse transcription droplet digital PCR (RT-ddPCR) in wastewater. We compared the two methods by measuring the viral ribonucleic acid (RNA) of a model virus Phi6 in samples collected from various treatment stages at the Westside Wastewater Treatment Facility in Fayetteville, AR. RNA was extracted from real and synthetic wastewater samples and analyzed in parallel using both RT-qPCR and RT-ddPCR. Findings reveal that both methods demonstrated similar …

Subsurface Characterization Using Electrical Resistivity Tomography (Ert) Integrated With Masw, P-Wave Refraction, And Boring Results, Mohammadyar Rahimi

Graduate Theses and Dissertations

Electrical resistivity tomography (ERT) has gained widespread application in geotechnical engineering as a non-invasive method for subsurface characterization. Despite its versatility, several challenges remain regarding its resolution capabilities, interpretive limitations, and integration with other investigative methods. This dissertation addresses three key applications of ERT, focusing on its effectiveness and limitations in resolving thin subsurface layers, detecting anomalies such as voids, and supporting environmental assessment in river restoration projects.

The first study investigates the ability of ERT to resolve thin, discontinuous clay layers beneath levees, using the Melvin Price Reach of the Wood River Levee on the Mississippi River as a …

Physiological And Molecular Responses Of Diverse Rice Genotypes Under Drought Stress, Huda Mohmmed Alshaya

Graduate Theses and Dissertations

Climate change-induced drought stress is a significant constraint on global rice (Oryza sativa L.) production, threatening food security. This study evaluated the drought resilience of 15 diverse rice genotypes from the USDA mini-core collection under field, greenhouse, and osmotic stress conditions. Field trials assessed reproductive-stage drought tolerance based on panicle length (PL), number of spikelets per panicle (NSP), and spikelet sterility (SS). Greenhouse experiments examined moisture retention at the vegetative stage. Significant genotypic variation was observed, with genotypes 310724, 310779, 311181, 311603, 311793, and Vandana exhibiting drought tolerance through stable PL and SS. Additionally, genotypes 310100, 310428, 311255, N22, …

Flexible Microelectrode-Based Impedance Immunosensor For Rapid Detection Of E. Coli O157:H7, Sonatan Kumar Biswas

Graduate Theses and Dissertations

Abstract Food contamination poses a significant threat to public health, the economy, and human health worldwide, occurring at any stage of the food supply chain, from farm to fork. Escherichia coli 0157:H7, recognized as one of the principal causes of foodborne illness, poses a considerable risk to food safety. The primary objective of this investigation is to devise a flexible microelectrode-based immunosensor capable of swiftly identifying E. coli O157:H7 cells without the need for incubation in a pure culture environment. In the development of the biosensor, the gold electrode (composed of 50% Au) underwent an initial coating process involving 2-aminoethanethiol/cysteamine, …

Achieving Flexible Fairness And Privacy In Federated Learning, Alycia N. Carey

Graduate Theses and Dissertations

Having access to large, high-quality datasets is crucial for training machine learning models that achieve satisfactory performance. Unfortunately, it is common that a single entity (e.g., mobile device or organization) does not have access to such datasets due to monetary or resource constraints. Traditional machine learning requires that all training data reside in a centralized location during the entire duration of model training, however, in many circumstances it is difficult or even impossible (e.g., due to governmental regulations) for multiple parties to combine their data to meet this constraint. Federated learning is a machine learning paradigm that facilitates the joint …

Geospatial Modeling Of Winter-Related Property Damage In Arkansas, Braedyn Mcbroom

Graduate Theses and Dissertations

Storm Data, a monthly publication by the National Weather Service with records of weather events, reports on property damage caused by natural hazards. Since 1996, the database has included winter-related events. While the property damage data is considered incomplete, no other unique, public datasets report winter-related property damage at the county level. From 1996 to 2024, Arkansas ranked #1 in winter-related property damage. To understand the factors that are driving property damage and potentially reduce Arkansas’ vulnerability to it, three groups separated by temporal periods, i.e., “2000” (01/1996 - 06/2005), “2010” (07/2005 - 06/2015), and “2020” (07/2015 - 06/2024) …

Crispr-Cas9 Integration Of Salmon Elovl2 In Zebrafish Enhances Lc-Pufa Biosynthesis And Growth Across Diets, Waleed Sami J. Al-Bachry

Graduate Theses and Dissertations

Fish are a rich source of EPA and DHA, which are well-known long-chain polyunsaturated fatty acids (LC-PUFAs). The sustainable production of these essential fatty acids poses significant challenges, mainly due to our dependence on marine fish and certain nuts. CRISPR-Cas system was utilized to insert the elongation of long-chain fatty acids-like2 (Elovl2) gene from Salmo salar into Danio rerio. Elovl2 was introduced at 10-15-minute post-fertilization, and successful integration confirmed by PCR genotyping, sequencing and expression of EGFP. Approximately 67% of injected embryos successfully exhibited EGFP and sequence results verified the gene integration of Salmo salar Elovl2 at the first start …

Variation In Stress Response Regulation Across Natural Isolates Of Saccharomyces Cerevisiae, Crystal Christine Crook

Graduate Theses and Dissertations

The stress response of Saccharomyces cerevisiae is a valuable area of study for understanding cellular adaptation mechanisms that govern survival in fluctuating environments. This dissertation investigates stress response regulation in yeast through the roles of Hog1 mitogen-activated protein kinase (MAPK) and the post-transcriptional regulator Mkt1, a key post-transcriptional regulator, in diverse wild yeast isolates. Hog1 is traditionally known for its central role in osmotic stress regulation in the high-osmolarity glycerol (HOG) pathway. This study expands the functional scope of Hog1 to include oxidative and ethanol-induced stress responses.

In parallel, we investigate post-transcriptional regulation of stress responses by the Mkt1 interactome, …

Simulations Of Richtmyer-Meshkov Instability Using High Order Weno Methods, Ryan Holley

Graduate Theses and Dissertations

Turbulent mixing due to hydrodynamic instabilities occurs in a broad spectrum of engineering, astrophysical and geophysical applications. Theory, experiment, and numerical simulation help us to understand the dynamics of interface instabilities between two fluids. This thesis presents an increasingly accurate and robust front tracking method for the numerical simulations of shock-induced turbulent mixing known as Richtmyer-Meshkov Instability (RMI). Front tracking is an adaptive computational method, where the interface instability is explicitly represented as lower dimensional manifolds moving through a rectangular grid. All the cell-center states (density, velocity and pressure) are updated using higher order weighted essentially non-oscillatory (WENO) scheme. Performance …

Design And Implementation Of Asynchronous Communication In Multi-Chiplet Systems: A Comparative Study Of Pseudo-Crossbar And Bus Architectures, Matthew Clemence

Graduate Theses and Dissertations

System-on-Chip (SoC) complexity continues to present challenges in global clock distribution and power management. The Globally Asynchronous Locally Synchronous (GALS) approach addresses these issues by enabling asynchronous communication between locally synchronous chiplets. This thesis details the design and implementation of two GALS architectures employing asynchronous handshaking protocols through Multi-Threshold CMOS NULL Convention Logic (MTNCL). The first architecture, a pseudo-crossbar, uses arbiters and multiplexers/demultiplexers (MUX/DEMUX) for prioritized and dynamic communication between chiplets. The second, a bus-based approach, employs D-latches to manage communication sequentially with predetermined interrupts. This research explores the detailed implementation, functional distinctions, scalability, and integration trade-offs inherent to each …

Evaluating The Impact Of Work-Based Learning On Postsecondary Completion And Job Placement Of Electronics Technology Students, Amanda J. Seidenzahl

Graduate Theses and Dissertations

The manufacturing industry today is facing a critical shortage in the availability of talent and skills needed in an ever-changing technological workforce. With an estimated 2.1 million jobs in the manufacturing industry predicted to be unfilled by 2030, organizations are struggling to find a workforce with the skills needed for this evolving industry (NAM, 2020; Ahmad, 2019). Employers have often suggested there is a lack of alignment between classroom experience in higher education, and work-based learning (WBL) is one option to bridge this gap (Krishnamoorthy & Keating, 2021). WBL provides real world experiences that connect learning in the classroom (Krishnamoorthy …

Exploring Hybrid Cohort-Based Doctoral Program Features That Support Nontraditional Doctoral Students’ Persistence: A Preregistered Case Study., Glenda Winborn

Graduate Theses and Dissertations

With the rise of hybrid learning models, non-traditional learners have greater access to doctoral education. However, attrition rates from doctoral programs remain high, ranging from 40% to 50% across all doctoral programs and exceeding these levels in online non-traditional programs. Numerous causes of attrition or persistence in doctoral studies have been researched and can affect the student, the academic institution, and the broader academic society. This qualitative case study will explore adult and lifelong learning doctoral students' perceptions of the programmatic and instructional support resources that have helped improve persistence in their program. Two of the important programmatic features of …

Automation Of Vulnerability And Patch Management: Information Extraction, Association, And Optimization, Kylie Mcclanahan

Graduate Theses and Dissertations

Vulnerability and patch management is an integral part of a robust cybersecurity program, yet it grows increasingly complex due to the sheer amount of data that must be analyzed. Particularly in Operational Technology (OT) environments, analysis must be done manually because of the lack of automated solutions. Additionally, there are many steps in this process, from the initial discovery of the vulnerability to the implementation of its remediation, and each step in the process requires different data in order to be performed effectively. In this work, we provide approaches and strategies to assist operators in industrial or OT environments throughout …

Development Of Si-Based Germanium-Tin Infrared Photodiode, Sylvester Amoah

Graduate Theses and Dissertations

Short-wave infrared (SWIR) and mid-wave infrared (MWIR) photodetectors have attracted increasing attention for the past few decades. SWIR and MWIR detectors are used for a wide range of applications in military and civilian defense, such as future automotive night vision, video surveillance security cameras, and integrated night vision in mobile/wearable electronics. The current market-dominating IR photodetector technology is mainly developed with the costly III-V or II-V material systems, such as InGaAs, InSb, and HgCdTe. While many efforts have been made towards the hybrid integration of III-Vs or II-VIs on a Si substrate, it is highly desirable to develop an alternative …

Fish Cultivation In Fallow Season Rice Fields: Effects On Landscape Methane Emissions, Samuel Carroll

Graduate Theses and Dissertations

Co-cultivation of aquatic animals and rice in the same field is a fairly common practice in various parts of the world, with a number of well-established agro-ecological benefits, such as decreasing the need for chemical pesticides and fertilizers, increasing soil organic matter, and reducing the land area needed for agricultural production. One area of environmental concern in rice production is greenhouse gas emissions. Rice production contributes about 10% of global anthropogenic methane (CH₄) emissions. Currently around 27.5% of Arkansas rice fields are flooded in the winter, which can increase CH₄ emissions in the fallow season by 45% …

Multi-Decadal Land Change Dynamics In Indonesia: Disentangling The Cycle Of Agricultural Land Conversions, Urbanization, And Deforestation, Wei Lun Tay

Graduate Theses and Dissertations

Land use and land cover change (LULCC) significantly impacts Earth’s environmental, climatic, and human systems, especially in tropical regions rich in natural resources and undergoing rapid development. This study examined the spatiotemporal dynamics of LULCC in Indonesia between 2003 and 2023 using remote sensing and geographic information systems/science (GISci) and explored knowledge gaps in agricultural land conversions and the impact of food security programs such as the Food Estate Program. This study employed the Moderate Resolution Imaging Spectroradiometer (MODIS) MCD12Q1 land cover data available through Google Earth Engine, and classified land cover changes into four dominant categories: forest land, mixed …

Survival Signature Estimation Using Optimization And Monte-Carlo Simulation For K ≥ 3 Classes Of Nodes On Two-Terminal Networks, Md Sazid Rahman

Graduate Theses and Dissertations

This research develops an efficient approach to estimating survival signatures for two-terminal networks with more than two classes of components. Recently, the survival signature has gained substantial attention in the literature on network reliability estimation due to its unique separability property, which enables passing the network topology information independent of the failure distribution of the components. Following recent results from the literature, estimating the two-terminal survival signature by Monte Carlo simulation entails solving a multi-objective maximum capacity path problem on a two-terminal network in each replication. We adapt a multi-objective Dijkstra’s algorithm from the literature to construct the set of …

Towards Multimodal Scene Graph Generation Approaches To Video Understanding, Trong-Thuan Nguyen

Graduate Theses and Dissertations

This thesis advances video understanding by enhancing Video Scene Graph Generation (VidSGG) through improved temporal modeling, the integration of long-range temporal dependencies via continuous updates to interaction histories, and the utilization of Large Language Models (LLMs) for scene graph reasoning. To this end, three novel datasets and corresponding approaches are introduced. First, the ASPIRe dataset incorporates interactivity annotations and leverages the Hierarchical Interlacement Graph (HIG) for hierarchical temporal modeling, providing deep insights into scene changes and effectively capturing intricate interactions. Next, the AeroEye dataset, focusing on drone videos, is paired with the Cyclic Graph Transformer (CYCLO), which establishes circular connectivity …

The Uneven Disruptions Covid-19 Caused To Scholars’ Publication: A Preregistered Study, Marco De Prosperis

Graduate Theses and Dissertations

This proposed, preregistered study investigates the uneven impacts of COVID-19 on scholarly productivity among University of Arkansas faculty, focusing on how demographic and professional factors—such as gender, ethnicity, academic rank, tenure status, field of study, and the presence of children—may have moderated productivity during the pandemic. Utilizing a non-experimental, cross-sectional design, this research will collect data from 160 full-time faculty members through an online survey. Grounded in Role Theory, the study will examine role conflict and enrichment as faculty navigated shifting responsibilities in research, teaching, and caregiving during remote work. This study is particularly relevant as many assistant professors who …

Vision-Based Multimodal Frameworks For Human Behavioral Analysis: Applications In Group Activity Understanding And Public Health, Naga Venkata Sai Raviteja Chappa

Graduate Theses and Dissertations

Group Activity Recognition (GAR) has emerged as a crucial problem in computer vision, with wide-ranging applications in sports analysis, video surveillance, and social scene understanding. Unlike traditional action recognition focused on individuals, GAR requires understanding complex spatiotemporal relationships between multiple actors, their interactions, and the broader context in which these activities occur. This complexity introduces unique challenges, including the need for accurate actor localization, modeling of inter-actor dependencies, and understanding of temporal evolution in group behaviors. While recent advances have shown promise, existing approaches often rely heavily on extensive annotations such as ground-truth bounding boxes and action labels, creating significant …

Administering Grant-Subsidized Workforce Training: A Critical Case Study, Kaleb Preston Futch

Graduate Theses and Dissertations

Grant monies are distributed for the purpose of funding workforce training programs aimed at affecting the skills gap in the United States. While research has shown that these grants are being awarded, there is not a well-established standard for designing and implementing the programs they fund. This study focuses on recording and classifying the lived experiences of grant staff working on a state funded workforce training program in the United States. This study will employ a qualitative case study approach designed to capture and codify, in the words of those most familiar with it, the aspects of the grant program …

A Case Study Of Intercultural Competence And Perceived Career Coaching Effectiveness In Higher Education, Robert C. Ellis

Graduate Theses and Dissertations

As the cost of a college education continues to increase dramatically, both policymakers and the general public have begun to question the return on investment in higher education. In response, post-secondary institutions have substantially invested in their career development offices in an effort to improve graduate career outcomes. Among the most widespread of the career services offered to college students is career coaching, which the literature supports as having a substantial impact on increasing starting salaries and job offers for new college graduates. Despite being more likely than their peers to utilize their institution’s career development offices, college graduates belonging …