Digital Commons Network^™

The Binding Of The Micronutrient Transition Metals To The Alkylation Products Of Chemical Warfare Agent, Sulfur Mustard, And Thiols, Potentially Giving New Understanding To Physiological Effects Of Exposure And Increased Toxicity, Colin O'Donnell

Graduate Theses and Dissertations

Model compounds, 3,6,9-trithaiundecane-1,11-dicarboxylic acid (TTDPA), 2,5,8-trithianonane-1,9-dicarboxylic acid (TTDAA), and 1,11-diamide-3,6,9-trithiaundecane (TTDAce), closely related to the adducts formed by cysteine alkylation of the chemical weapon, sulfur mustard, were synthesized. It is shown that TTDPA forms complexes with key metal micronutrients: copper, nickel, cobalt, manganese, and zinc. Though the strength of binding to TTDPA varies, the complexes in many cases precipitate from solution. All metals produced a visible precipitate upon interaction with TTDPA under the conditions tested, however only Cu2+, Mn2+, and Zn2+ produced enough to be measured. The mass of formed precipitate seemed to peak at an equimolar ratio of TTDPA …

Lyubeznik Numbers Of Unmixed Edge Ideals, Sara Rae Jones

Graduate Theses and Dissertations

Lyubeznik numbers, defined in terms of local cohomology, are invariants of local rings that are able to detect many algebraic and geometric properties. Notably they recognize topological behaviors of various structures associated to their rings. We will discuss computations of these numbers for unmixed edge ideals by giving a completely combinatorial construction which realizes the connectedness information captured by these numbers.

Diagnosing Excess Nitrogen In Rice Using Post-Season Tissue Samples, Kyle Hoegenauer

Graduate Theses and Dissertations

Proper nitrogen (N) management in rice production can be difficult to achieve without the aid of tools such as soil and tissue tests. There are no tests currently available to rice producers that determine whether N has been managed properly throughout the season or that detect instances of over fertilization. Rice stalk samples were collected from N response trials within 3 days of harvest from the primary Arkansas rice growing region in 2016-2018. Stalk samples were analyzed for N concentration through a KCl extraction and spectrofluorometric quantification. Samples analyzed with leaf material intact contained statistically different N concentrations than samples …

Fiber-Based Time-Correlated Single Photon Counting As A Method For Investigating Metabolism During Tetanic Contraction Of Skeletal Muscle, Kathryn Miller Priest

Graduate Theses and Dissertations

Nicotinamide adenine dinucleotide (NAD) is a cofactor that serves to shuttle electrons during metabolic processes such as glycolysis, the tricarboxylic acid cycle, and oxidative phosphorylation (OXPHOS) [1-5]. The reduced form of NAD, NADH, is autofluorescent, making it a measurable characteristic in the investigation of metabolic changes. The fluorescence lifetime of NADH is dependent on the state of protein binding, specifically free or bound NADH, allowing for detection of metabolic shifts between glycolysis (free NADH) and OXPHOS (bound NADH) [6-16]. Fiber-coupled time-correlated single photon counting (TCSPC) equipped with an implantable needle probe can be used to measure NADH lifetime in vivo …

Delineating Field Variation Using Apparent Electrical Conductivity In An Ozark Highlands Agroforestry System, Shane Reid Ylagan

Graduate Theses and Dissertations

Little to no work has been conducted assessing field variability using repeated electromagnetic induction (EMI) apparent electrical conductivity (ECa) surveys in agroforestry (AF) systems within regions similar to the Ozark Highlands. The objectives of this thesis were to identify i) spatiotemporal ECa variability; ii) ECa-derived soil management zones (SMZs); iii) correlations among EMI-ECa and in-situ, sentential-site soil properties; iv) whether fewer, EMI-ECa surveys could be conducted to capture similar ECa variance as mid-monthly EMI-ECa surveys; v) correlations between ECa and forage yield, tree growth, and terrain attributes based on plant (forage and tree) species, and fertility treatments, and ECa-derived SMZs, …

Deciphering Surfaces Of Trans-Neptunian And Kuiper Belt Objects Using Radiative Scattering Models, Machine Learning, And Laboratory Experiments, Al Emran

Graduate Theses and Dissertations

Decoding surface-atmospheric interactions and volatile transport mechanisms on trans-Neptunian objects (TNOs) and Kuiper Belt objects (KBOs) involves an in-depth understanding of physical and thermal properties and spatial distribution of surface constituents – nitrogen (N2), methane (CH4), carbon monoxide (CO), and water (H2O) ices. This thesis implements a combination of radiative scattering models, machine learning techniques, and laboratory experiments to investigate the uncertainties in grain size estimation of ices, the spatial distribution of surface compositions on Pluto, and the thermal properties of volatiles found on TNOs and KBOs. Radiative scattering models (Mie theory and Hapke approximations) were used to compare single …

Efficient Hierarchical Space-Time Models For Large Areal Datasets With Application To Forest Inventory Mapping Using Remote Sensing Imagery, Md Kamrul Hasan Khan

Graduate Theses and Dissertations

The focus of this dissertation is development of a novel hierarchical framework, that can be used for predictive modeling of Forest Inventory and Analysis (FIA) data over large regions. This dissertation has two significant contributions. Based on a study region in north-central Wisconsin, we analyze satellite imagery, along with a sample of national forest inventory field plots, to monitor and predict changes in forest conditions over time. The auxiliary data from the satellite imagery of this region are relatively dense in space and time, and can be used to learn how forest conditions changed over that decade. However, these records …

Schools Of Rivals: Physicians, Fights, And Reform In Nineteenth-Century, Southern Medical Education, Laura Elizabeth Smith

Graduate Theses and Dissertations

While the professionalization of medicine in the nineteenth century hinged on community trust, faculty at Southern medical schools hurt their own reputations with their proprietary schools, their public rivalries, and their competition for clinical material and cadavers. Attempts to regulate medical schools also became fodder for doctors to slander each other, all arguing that their methodologies and their schools were superior. This fierce competition resulted from the constant need to lure in more students to ensure these schools’ survival, but it hurt the reputation of doctors as a whole, convincing the public that one doctor seemed just as incompetent and …

Effect Of Varying Amounts Of Sandstone On The Performance Of Asphalt Mixtures In Arkansas, David Murphy

Graduate Theses and Dissertations

There are many different species and subspecies of aggregate used across the state of Arkansas, and the rest the country. However, it cannot be presumed that the amount and type of these aggregates will be compatible with the commonly used asphalt binder of an area; this can lead to performance issues and premature pavement damage. It has been suspected in Arkansas that an excessive amount of sandstone in asphalt mixtures may be a culprit of some of these premature pavement damage issues, especially regarding the moisture susceptibility of a pavement. This study aimed to analyze the performance effects of using …

The Effect Of Plant Elicitor Peptide On Nematode Infected Soybean, Siyang Liu

Graduate Theses and Dissertations

Soybean (Glycine max), an important economic crop native to East Asia, is grown worldwide for its edible beans. Soybean plants are vulnerable to a wide range of diseases, and nematodes are among the worst pests of soybean. The southern root-knot nematode (Meloidogyne incognita) and soybean cyst nematode (Heterodera glycines) are both notable nematode pests of soybean, with the soybean cyst nematode causing more than 30% of total yield loss in the US. Numerous attempts have been made to control soybean nematodes over the past several decades, and genetic engineering technology has received a lot of attention in recent years. Plant …

Environmental Communication: Changing The Attitude-Behavioral Gap In Science Communication Utilizing Strategic Messaging, Carrie Helgeson Nelms

Graduate Theses and Dissertations

National Polls in the United States consistently find the public’s beliefs and attitudes about climate change and other environmental issues significantly diverge from those held by the science community. A communication gap between the findings on the causes and effects of environmental issues and the public’s inability to interpret or refuse to accept these findings are possible causes of this divergence. This communication gap constitutes a threat to society because of inaction to environmental problems and points to needed changes in scientific messaging that better informs and motivates behavioral change. The present research employed a strategic message design to affect …

Analysis Of Seismicity And Related Seismic Risk In Muslim Countries: Case Studies From Afghanistan And Pakistan, Ikramuddin Bahram

Graduate Theses and Dissertations

How communities respond to a natural hazard is influenced by how they perceive it. This dissertation evaluated the gap between intent and action regarding earthquake hazards in Muslim countries with a focus on Afghanistan and Pakistan. Cultural biases provided predictions of risk perceptions and risk-taking preferences that were often more powerful than measures of knowledge and experience. In Muslim communities, perception of risk was influenced by the teachings of Islam and related rituals, traditions, and culture.

This study evaluated the seismicity and earthquake hazard in Afghanistan and Pakistan. Assessments of seismic risk and perception of danger were conducted to examine …

Assessing Consumer Demand, Producer Profitability, And The Environmental Impacts Of Conservation Agriculture Adoption In Sub-Saharan Africa, Willy Byamungu Mulimbi

Graduate Theses and Dissertations

This dissertation explores three aspects of conservation agriculture (CA) in the Sub-Saharan African region (SSA). The first article examines the demand side of CA and explores whether urban maize (Zea mays L.) consumers in the Democratic Republic of the Congo (DRC) would be willing to pay a premium for CA-produced maize flour. The second article estimates the effects CA provides to adopters and their farms in smallholder farming systems in the DRC, focusing on changes in soil properties and cowpea (Vigna unguiculata) yields. The final article uses a Life Cycle Assessment (LCA) approach to monetize the environmental impacts of adopting …

Data-Driven Research On Engineering Design Thinking And Behaviors In Computer-Aided Systems Design: Analysis, Modeling, And Prediction, Molla Hafizur Rahman

Graduate Theses and Dissertations

Research on design thinking and design decision-making is vital for discovering and utilizing beneficial design patterns, strategies, and heuristics of human designers in solving engineering design problems. It is also essential for the development of new algorithms embedded with human intelligence and can facilitate human-computer interactions. However, modeling design thinking is challenging because it takes place in the designer’s mind, which is intricate, implicit, and tacit. For an in-depth understanding of design thinking, fine-grained design behavioral data are important because they are the critical link in studying the relationship between design thinking, design decisions, design actions, and design performance. Therefore, …

The Office Of Possible Projects, Juliette Walker

Graduate Theses and Dissertations

This writing is a companion to the MFA thesis projects that I presented in the Spring 2022 semester at the University of Arkansas in Fayetteville, Arkansas. My thesis work did not exist as a singular, solo exhibition in a traditional gallery space like it did for most of the artists in my graduating cohort; rather, I completed three different but substantial and interrelated projects, many of which occurred outside of traditional art spaces: the Office of Possible Projects at the Fayetteville Public Library, the Cake Stand Biennale which took place across the city of Fayetteville, Arkansas, and the office of …

Mitochondrial Dna Diversity, Parasite And Pathogen Occurrence, And A Potential Disease Vector In Managed And Unmanaged Honey Bee, Apis Mellifera L. Populations, Dylan Cleary

Graduate Theses and Dissertations

The western honey bee, Apis mellifera L., is a globally important pollinator plagued by several harmful stressors impacting colony health and survival. At least eight A. mellifera subspecies were imported and continue to be the genetic ancestors of U.S. honey bee populations today. Successive genetic bottle-neck events have led to reduced genetic diversity in U.S. honey bees. First, the subset of subspecies imported into the U.S. represents only a third of A. mellifera subspecies. Next, the parasitic varroa mite reduced managed and feral populations. Third, ongoing breeding practices have selected for traits from a single genetic lineage and bred from …

Development Of Deep Shear Wave Velocity Profiles And An Approach To Generate Site Signature Consistent Pseudo Shear Wave Velocity Profiles In The Mississippi Embayment, Ashraf Kamal Himel

Graduate Theses and Dissertations

This dissertation details the development of a surface wave method (SWM) technique to generate deep shear wave velocity profiles (VS profiles), applying this technique at 24 sites across the Mississippi embayment and developing an approach to generate pseudo site signature consistent VS profiles from velocity functions and fundamental frequency. In the presented SWM technique, active and passive source surface wave measurements are inverted along with fundamental frequency to develop a site signature consistent VS profile. Multiple transformation methods, including MSPAC, HRFK and FK are used to resolve experimental dispersion data from surface wave measurements. SWM VS profile at the Central …

Initial Exploration Of Reduced Gyrations For Arkansas Asphalt Mix Designs, Jocie L. Baker

Graduate Theses and Dissertations

The most common distresses in asphalt pavement are cracking and rutting. These distresses plague almost every asphalt roadway in the world. Finding ways to mitigate these distresses will improve the performance of asphalt pavements. One way to combat the premature cracking of asphalt in the field is to ensure there is enough asphalt binder within the mix. This will help the flexibility of the asphalt undergoing large loads and deformation. However, it is widely accepted that mix designs across the country lack the appropriate amount of asphalt binder in their mixes, causing dry mix designs that are subject to cracking …

Constraint-Aware, Scalable, And Efficient Algorithms For Multi-Chip Power Module Layout Optimization, Imam Al Razi

Graduate Theses and Dissertations

Moving towards an electrified world requires ultra high-density power converters. Electric vehicles, electrified aerospace, data centers, etc. are just a few fields among wide application areas of power electronic systems, where high-density power converters are essential. As a critical part of these power converters, power semiconductor modules and their layout optimization has been identified as a crucial step in achieving the maximum performance and density for wide bandgap technologies (i.e., GaN and SiC). New packaging technologies are also introduced to produce reliable and efficient multichip power module (MCPM) designs to push the current limits. The complexity of the emerging MCPM …

An Innocent Bystander Walks Into A Bar: The Influence Of Temporal Proximity And Familiarity On Unconscious Transference, Nia Gipson

Graduate Theses and Dissertations

According to The Innocence Project, 69% of DNA exonerations in the United States involved mistaken eyewitness identification as a contributing factor to these errant convictions. Psychologists have contributed towards minimizing mistaken identifications by proposing best practices that law enforcement still follow today. One understudied cause of mistaken eyewitness identification is unconscious transference (UT). UT is a memory error in which a person encountered in an innocent context becomes confused with a person seen in a guilty context (Loftus, 1976). Past research has established some boundary conditions for when UT can occur; however, the limited methodology has resulted in narrow conclusions …

A Memory-Centric Customizable Domain-Specific Fpga Overlay For Accelerating Machine Learning Applications, Atiyehsadat Panahi

Graduate Theses and Dissertations

Low latency inferencing is of paramount importance to a wide range of real time and userfacing Machine Learning (ML) applications. Field Programmable Gate Arrays (FPGAs) offer unique advantages in delivering low latency as well as energy efficient accelertors for low latency inferencing. Unfortunately, creating machine learning accelerators in FPGAs is not easy, requiring the use of vendor specific CAD tools and low level digital and hardware microarchitecture design knowledge that the majority of ML researchers do not possess. The continued refinement of High Level Synthesis (HLS) tools can reduce but not eliminate the need for hardware-specific design knowledge. The designs …

Intestinal Microbiota Analysis Of Broiler Chickens Under Necrotic Enteritis Challenge And Tributyrin Supplementation, Taylor Nicole Mckinney

Graduate Theses and Dissertations

Poultry is a staple protein source for most of the planet. Until recently, antibiotic growth promoters (AGPs) were used to prevent illnesses in commercial chicken production. Currently, this is not possible due to regulations and consumer concern, but without such a preventative, diseases like necrotic enteritis (NE) have reemerged, posing a threat to bird health, and ultimately, our food source. Necrotic enteritis is a severe gastrointestinal disease caused by the gram-positive pathogen, Clostridium perfringens. Clinical features of this disease are diarrhea, intestinal lesions, and death, with a high transmission rate. In a subclinical form, growth performance is diminished and is …

Changes Of Winter Severity In Arkansas During 1901-2100, Christian Garcia

Graduate Theses and Dissertations

The objective of this study was to quantify the winter severity in a way that was reproduceable and easy to understand. The Accumulated Winter Severity Seasonal Index (AWSSI) was chosen for this reason and was used to quantify winter severity by season across the state of Arkansas. The variables that go into the AWSSI calculation are maximum daily temperature, minimum daily temperature, daily snowfall, and daily snow depth. When the snowfall and snow depth were missing, they can be estimated using daily temperature and precipitation. Then the estimated snowfall and snow depth can be subsequently used to quantify the winter …

Etching Process Development For Sic Cmos, Weston Reed Renfrow

Graduate Theses and Dissertations

Silicon Carbide (SiC) is an exciting material that is growing in popularity for having qualities that make it a helpful semiconductor in extreme environments where silicon devices fail. The development of a SiC CMOS is in its infancy. There are many improvements that need to be made to develop this technology further. Photolithography is the most significant bottleneck in the etching process; it was studied and improved upon. Etching SiC can be a challenge with its reinforced crystal structure. Chlorine-based inductively coupled plasma (ICP) etching of intrinsic SiC and doped SiC, SiO2, and Silicon has been studied. A baseline chlorine …

Examining The Intersection Of Cultural Competence And Classroom Management Self-Efficacy In Northwest Arkansas K-6 Teachers, Bonnie Culp King

Graduate Theses and Dissertations

This study aims to examine the relationship between Northwest Arkansas K-6 teachers’ cultural competence and classroom management self-efficacy. Multiple linear regression will be the quantitative approach used for analyzing K-6 teachers’ self-reported data. Valid and reliable instruments will be used to measure the concepts as operationalized for this study. Cultural competence will be measured using the “Multicultural Teaching Competency Scale” and classroom management self-efficacy will be measured using the “Teachers’ Sense of Efficacy Scale.” Demographic information will be collected to control for two variables: a teacher’s years of experience in teaching and race/ethnicity. Descriptive statistics and inferential statistics will be …

Optimization Techniques For Soil Organic Carbon Prediction Using Mid-Infrared Spectroscopy, Minerva J. Dorantes

Graduate Theses and Dissertations

Resource-efficient techniques for accurate soil carbon estimation are necessary to satisfy the increasing demand for spatiotemporal data. In the last thirty years, mid-infrared (MIR) soil spectroscopy has developed as an accurate, rapid, cost-effective, and non-destructive technique for soil organic carbon (SOC) analysis. In soil spectroscopy, a calibration model relates spectral data to a corresponding measured soil property and is subsequently used to predict this value from new spectral data. Various optimization techniques have been used to improve the statistical performance of calibrations; however, there is little consensus on the conditions that make these techniques effective. The objectives of this research …

Performance And Fouling During Bioreactor Harvesting, Da Zhang

Graduate Theses and Dissertations

Tangential flow filtration has many advantages for bioreactor harvesting as the permeate could be introduced directly to the subsequent capture step, the process is easy to scale up, and fouling of the filter is limited by the cross flow. However, membrane fouling has limited its widespread use. This is particularly problematic given the high cell densities encountered today. Here a reverse asymmetric commercial membrane, BioOptimal™ MF-SL (Asahi Kasei), where the more open surface faces the feed stream, and the tighter barrier layer faces the permeate stream, has been investigated for bioreactor harvesting. The open surface contains pores up to 40 …

Study Of Single-Photon Wave-Packets With Atomically Thin Nonlinear Mirrors, Christopher Klenke

Graduate Theses and Dissertations

A novel controlled phase gate for photonic quantum computing is proposed by exploiting the powerful nonlinear optical responses of atomically thin transition metal dichalcogenides (TMDs) and it is shown that such a gate could elicit a π-rad phase shift in the outgoing electric field only in the case of two incident photons and no other cases. Firstly, the motivation for such a gate is developed and then the implementation of monolayer TMDs is presented as a solution to previous realization challenges. The single-mode case of incident photons upon a TMD is derived and is then used to constrain the more …

Muscadine Grapes: Identifying Unique Attributes And Postharvest Practices, John Cody Rawls

Graduate Theses and Dissertations

Arkansas has a long history of grape and wine production, and muscadine grapes (Vitis rotundifolia Michx.), a native disease-resistant grape, are an important part of that industry. Muscadine grapes can be sold as a fresh-market grape or made into juice, wine, and other products. Additionally, the University of Arkansas System Division of Agriculture (UA System) breeding program has a focus on creating new muscadine cultivars with commercial potential. The objectives of this research were to evaluate muscadine grape genotypes (cultivars and breeding selections) for fresh market consumption and wine production in 2020 and 2021. 33 seeded and seedless genotypes of …

The Effects Of Immersive Virtual Environments On Motivation, Oral Communication, And Instructional Strategy In Efl Classrooms, John Martin Shipko

Graduate Theses and Dissertations

The creation of web-based real-time computer simulations has given language educators incredible new opportunities to create immersive experiences for English as a Foreign Language (EFL) learners. This thesis reviewed 12 empirical studies, 3 previous literature reviews, 3 non-empirical journal articles, and 23 additional background sources investigating the impact of Immersive Virtual Environments (IVE) on EFL learners’ motivation and oral communication in EFL learning. 12 empirical studies were analyzed closely while other sources were used to provide additional information and theoretical insights. The findings indicate that IVEs offer novel ways to connect EFL learners to native-speaking communities where they can acquire …