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Catalytic Activity Of Tungsten-Dioxo And Tungsten-Diimido Complexes, Kayla Denike

Graduate Theses and Dissertations

Due to the significant decline in the availability of petrochemical resources and the increasing demand for the useful olefin mixtures extracted from oil, a sustainable and efficient alternative to these materials has become vital. Fortunately, renewable biomass derived materials may serve as a sustainable solution to the limited resources problem. Molecules derived from the degradation of biomasses are highly oxygenated and highly functionalized. Developing processes to efficiently defunctionalize these oxygen-rich materials will lead to potential up-conversion to carbon chemicals. Homogeneous catalytic deoxygenation processes present an opportunity to access valuable carbon commodity chemicals from biomass derived polyols. This dissertation details the …

The Effect Of Water Management And Ratoon Rice Cropping On Methane Emissions And Harvest Yield In Arkansas, Marguerita Leavitt

Graduate Theses and Dissertations

Sustainable intensification of rice farming is crucial to meeting human food needs while reducing environmental impacts. Rice produces 8% of all anthropogenic CH4, which is a potent greenhouse gas. CH4 emissions can potentially be reduced by cultivation practices that minimize the number of days the fields are saturated, such as dry-seeding instead of water-seeding and irrigation using the alternate wetting and drying (AWD) technique instead of delayed, continuous flooding (DF). Ratoon cropping, wherein a second crop of rice is grown from the harvested stubble of the first crop, can be used to produce additional yield with minimal labor, but may …

Quantum Dots In Two-Dimensional Tungsten Diselenide, Jeb Allen Michael Stacy

Graduate Theses and Dissertations

This work focuses on the investigation of single and double quantum dots in two-dimensional transition metal dichalcogenide tungsten diselenide (WSe_2) as a means to evaluate the valley degree of freedom as a potential qubit and ambipolar tungsten diselenide monolayers as single photon sources. Gate-defined quantum dots in monolayer and bilayer WSe_2 were fabricated and characterized. Single dot devices are gated from above and below the WSe_2 to accumulate a hole gas. Temperature dependence of Coulomb-blockade peak height is consistent with single-level transport. Excited-state transport in the quantum dot is shown for both monolayer and bilayer devices. Magnetic field dependence of …

Implementing Food Pantry Nutrition Policies: Perspectives From The Field, Jessica Vincent

Graduate Theses and Dissertations

The charitable food system includes food pantries and are often used by individuals and households who are food insecure (Kuhns & Norotny, 2021; Seligman & Berkowitz, 2019; Sangye, 2013). Adults with any level of food insecurity have a 43% to 53% greater risk of developing a chronic disease than those who are food secure. Those who are food secure have a 37% risk of developing a chronic disease (Gregory & Coleman-Jenson, 2017). For this reason, efforts are being made from state and federal levels to focus on nutrition security, rather than only food security, by increasing the percentage of nutrient …

Effective Knowledge Graph Aggregation For Malware-Related Cybersecurity Text, Phillip Ryan Boudreau

Graduate Theses and Dissertations

With the rate at which malware spreads in the modern age, it is extremely important that cyber security analysts are able to extract relevant information pertaining to new and active threats in a timely and effective manner. Having to manually read through articles and blog posts on the internet is time consuming and usually involves sifting through much repeated information. Knowledge graphs, a structured representation of relationship information, are an effective way to visually condense information presented in large amounts of unstructured text for human readers. Thusly, they are useful for sifting through the abundance of cyber security information that …

Local Broadcast Reporters Maintaining Social Responsibility And Mental Health While Serving A Community Under Lockdown, Mary-Morgan Ellis

Graduate Theses and Dissertations

This study looks at local broadcast news reporters working in Northwest Arkansas before, at the start, and during the COVID-19 global pandemic. Research for this study includes a content study of the tweets and Twitter accounts of eleven local reporters. This study considers the social responsibility theory and examines how these eleven local reporters use the theory in their everyday work. Research found, though these reporters don’t credit the theory by name, they are still putting its guidelines into effect as a sort of moral compass when creating objective and representative news for their communities. The research also found that …

Xps And Ipe Determination Of Band Offsets Of Germanium Based Materials, Justin Michael Rudie

Graduate Theses and Dissertations

Germanium tin and silicon germanium tin are group IV semiconductor alloys that have gained significant interest in recent years for their potential use in optoelectrical devices. While silicon and germanium are indirect bandgap materials on their own, alloying them with tin in sufficient quantities leads to a transition to direct bandgap alloys. Direct gap performance opens the door for efficient light emitting and detecting devices fabricated entirely on group IV materials that are compatible with the industry standard CMOS manufacturing techniques. Germanium tin and silicon germanium tin have bandgaps that respond to light in the mid to near infrared spectrum …

Case Study: Exploring Inservice Teachers’ Perceptions And Experiences Of The Effectiveness Of Gifted Preparation And Training Programs In Saudi Arabia, Khlood Khaled Alshareef

Graduate Theses and Dissertations

In Saudi Arabia, the teaching of gifted and talented students is relatively new, and research that describes the quality and effectiveness of teachers' gifted preparation programs and the training sessions they receive remain rather limited and inconsistent. Purpose: This dissertation focuses on understanding the perceptions and experiences of in-service teachers regarding gifted-focused preparation and training programs in the country. Research Design: Data were collected through observation and semi-structured interviews with teachers of gifted and talented students in the country. Findings: Analysis of the data revealed six themes related to teachers’ perceptions and experiences of preparation and training programs in Saudi …

Study Of Thin Gan/Ingan/Gan Double Graded Structures For Future Photovoltaic Application, Mirsaeid Sarollahi

Graduate Theses and Dissertations

Indium gallium nitride (In_x Ga_(1-x) N) materials have displayed great potential for photovoltaic and optoelectronic devices due to their optical and electrical properties. Properties such as direct bandgap, strong bandgap absorption, thermal stability and high radiation resistance qualify them as great materials for photovoltaic devices. The tunable bandgap which absorbs the whole solar spectrum is the most significant feature which became attractive for scientists. The bandgap for these materials varies from 0.7 eV for InN to 3.4 eV for GaN covering from infrared to ultraviolet. In_x Ga_(1-x) N wurtzite crystal is grown on GaN buffer layer by Molecular Beam Epitaxy …

Effects Of An Injectable Zinc Solution At Weaning As An Alternative Castration Method In Beef Cattle, Reagan Nicole Cauble

Graduate Theses and Dissertations

Two experiments were conducted to investigate a 1 mL intratesticular zinc (100 mg Zn) injection administered into each testicle at weaning (Z) and its effects on growth, health, behavior and testosterone. In the first experiment, beef bulls were assigned randomly to treatment at birth: 1) surgically castrated at birth (S; n = 37) or 2) Z (n = 37). Testicular thickness differed by day (P < 0.01) for Z. Testosterone concentrations were greater in Z by d 77 and remained so through d 280 (P = 0.02) compared to S. Zinc injected calves were heavier at the trail’s conclusion (P ≤ 0.04), had greater ADG overall (P < 0.01), heavier hot carcass weight (P = 0.01), and greater lean muscle area (P = 0.01) compared to S; but a lower marbling score (P < 0.01). Yield Grade, dressed carcass yield and fat thickness were similar (P ≥ 0.14). Zinc injected calves had greater haptoglobin (Hp) concentrations (P < 0.01). Zinc injected calves had greater concentrations of white blood cells on d 1 and 2 and greater concentrations and proportions of neutrophils on d 1, 2 and 3 (P < 0.01). Conversely, S had a greater percentage of lymphocytes on d 1, 2 and 3 and a lower ratio of neutrophils to lymphocytes during that same time (P < 0.01). Zinc injected calves spent more time on their side or sternum on d 1 and more time on their side on d 2 while S spend more time standing during that time (P < 0.01). During d 3, 4, 5, and 6, Z stood more while S laid on their sternum (P < 0.01). In trail 2, beef bulls were allocated randomly to treatment one week post weaning: 1) banded (B; n = 42) or 2) Z (n = 39). Body weights were similar (P ≥ 0.39) but ADG improved for Z compared to B (P = 0.05). Testosterone concentrations were greater in Z compared to B (P ≤ 0.02). Testicular width in Z differed by d (P < 0.01). Zinc castrated calves spent more time on their side compared to B one day post castration (P = 0.03) until d 3 and 4 where B spent more time on their side (P ≤ 0.02). Banded calves stood more the first two days (P ≤ 0.01). On days 3, 4, 5, and 6, Z stood more (P ≤ 0.01) while B were on their sternum (P ≤ 0.03). Banded calves had lower Hp concentrations compared to Z (P ≤ 0.01). Total white blood cell concentrations, proportions and concentrations of neutrophils, and proportion of lymphocytes were greater in Z compared to B on d 1, 2, and 3 (P ≤ 0.01). There was no interaction between treatments over time for IL1β, IL6, and TNFα expression (P ≥ 0.83). The findings in both studies indicate that intratesticular Zn injections at weaning can improve growth performance and some carcass attributes but produce a heightened inflammatory and immune response and cause discomfort. Injecting zinc, as formulated and administered in these trails, does not result in complete castration of beef calves at this age and therefore cannot be considered a true castration alternative.

Competing Behaviors Of Thermoregulation And Ambush Foraging In The Timber Rattlesnake (Crotalus Horridus Horridus): A Mechanistic Assessment Of Thermal Conduction, Larry K. Kamees

Graduate Theses and Dissertations

The interaction between the biophysical environment and ectotherm morphology elicits behaviors designed to maintain internal body temperature (Tb) within a range that promotes physiological functions. The short-term requirements of mass (energy requirements) and heat balance are subject to tradeoffs imposed by the organisms current physiological (heat and mass budgets) and environmental (biophysical, demographic, social, and predation) constraints and available resources. In temperate forests, extreme temperatures are common in summer even with intermittent sun exposure due to dense canopy cover. In Spring and Fall, temperatures can range from below freezing to 35 ℃ in 24 hrs. An ambush predator like the …

Wind Tunnel Modeling Of Jack Rabbit Ii Mock Urban Environment Gas Concentration Measurements, Sami S. Fares

Graduate Theses and Dissertations

The 2015 Jack Rabbit (JR) II field trials were conducted to improve understanding of the denser-than-air dispersion of chlorine in an urban environment. The field study involved five large-scale, outdoor release trials of chlorine in a mock urban environment (MUE) at Dugway Proving Ground (DPG). Various instrumentation was deployed, including JazTM Ultraviolet-Visible (UV-Vis) point sensors capable of measuring gas-phase chlorine concentration throughout the mock urban array.

The Chemical Hazards Research Center (CHRC) was tasked by the Chemical Security Analysis Center (CSAC) with the Mock Urban Wind Tunnel (MUWT) program to study the 2015 JR II Trials at wind tunnel scale. …

Improving Computation For Hierarchical Bayesian Spatial Gaussian Mixture Models With Application To The Analysis Of Thz Image Of Breast Tumor, Jean Remy Habimana

Graduate Theses and Dissertations

In the first chapter of this dissertation we give a brief introduction to Markov chain Monte Carlo methods (MCMC) and their application in Bayesian inference. In particular, we discuss the Metropolis-Hastings and conjugate Gibbs algorithms and explore the computational underpinnings of these methods. The second chapter discusses how to incorporate spatial autocorrelation in linear a regression model with an emphasis on the computational framework for estimating the spatial correlation patterns.

The third chapter starts with an overview of Gaussian mixture models (GMMs). However, because in the GMM framework the observations are assumed to be independent, GMMs are less effective when …

Trauma Treatment For Youth In Foster Care: A Mixed-Methods Study Of Clinician Perspectives And Treatment Model Use, Allison Blake Smith

Graduate Theses and Dissertations

Youth in foster care experience trauma exposure and subsequent trauma-related disorders at much higher rates than their peers, with prevalence rates comparable with veterans of war. Although youth in foster care appear to receive services at higher rates than their peers, little is known about what outpatient care consists of, particularly for trauma-related disorders. Furthermore, although several evidence-based treatments exist for the treatment of child and adolescent trauma, little is known about how appropriate and effective existing treatment approaches are for youth in foster care. The current study used a mixed methods approach to examine a) the range of evidence-based …

Mental Health Stigma And Psychological Help-Seeking In Adolescence, Laura Austin

Graduate Theses and Dissertations

Although an overwhelming number of adolescents in the U.S. experience significant psychological distress, the majority of these youth do not receive formal mental health services. Mental health stigma has been identified as a significant barrier to psychological help-seeking during adolescence, with treatment stigma (or the stigma associated with seeking formal psychological services) as the strongest predictor of help-seeking when compared to other types of mental health stigma. Given the long-term impacts of untreated psychological distress in adolescence, more research is needed to understand the influence of mental health stigma on help-seeking during this developmental stage. Furthermore, more research is needed …

Rodent Dental Microwear Texture Analysis As A Proxy For Fine-Scale Paleoenvironment Reconstruction, Jenny H. E. Burgman

Graduate Theses and Dissertations

Dental microwear texture analysis (DMTA) of fossil fauna has become a valuable tool for dietary inference and paleoenvironment reconstruction. Most of this work has utilized larger taxa with larger home ranges. These studies may result in broader-scale habitat inferences that could mask the details of complex mosaic habitats. Rodent DMTA offers an opportunity to work at finer spatial scales because most species have smaller home ranges. Rodents are also keystone species within their ecosystems, abundant, ubiquitous, and found in many fossil deposits. These attributes make them excellent proxies for environmental reconstructions. However, the application of DMTA to rodents remains relatively …

There Are Ghosts In The Machine, Jonathan Green

Graduate Theses and Dissertations

There are ghosts in the machine is a body of paintings that dare to dissolve the boundaries between my physical body, intimate desires, and paintings. Utilizing the aesthetics of leather lifestyles, the paintings express the transformational potential of desire and transgression. Oriented within my experience as a queer, transgender male, I call upon influences that range from the body horror classics by director David Cronenberg or the transgressive attitude of Nine Inch Nails, to theoretical works on the power of eroticism by Audre Lorde and Georges Bataille.Modified by hardware such as chains, zippers, and grommets, the paintings express the transformational …

Refining Particle Size Specification For Asphalt Emulsion, Pedro Luis Diaz Romero

Graduate Theses and Dissertations

Pavements begin to deteriorate as soon as they are constructed, and traffic is released. The rate at which a pavement deteriorates depends on the material quality, the environment, and the loads carried. To properly preserve pavements and extend their life, various pavement preservation treatments are used. For flexible pavements, a considerable number of these treatments use asphalt emulsion (which are refer to simply emulsions from here on). Emulsions are classified based on their particle charge and reactivity. Emulsions used in chip seals are usually of rapid set reactivity and are classified based on tests over fifty years old.

It has …

Temporal Changes In Surface Water Availability: Patterns Of Seasonal Shift On Water Stress In The Conterminous Us Under A Changing Climate, Quinn Montana

Graduate Theses and Dissertations

The argument could be made that there is nothing more valuable on the planet than water. Our lives depend upon it. Climate change is already having an impact on the United States (US) and water stress will be one of the problems we increasingly face in coming decades. Regional research has shown that one or another part of the conterminous US (CONUS) is expected to experience an annual deficit or a surplus in runoff. Further studies have looked at changing patterns over the CONUS as a whole. Other research has focused on a particular season. This work addresses a gap …

Meet Everyone With Art At Location And Time; M.E.A.L.T. Phase 1, Michael Louis Leblanc

Graduate Theses and Dissertations

As an artist who participates in socially engaged arts, it is paramount in my practice to cultivate the balanced power relationship between the audience and artist by providing an ongoing safe environment, accessible subject matter and venue location, and a mechanism that not only calls for participation from the audience but empowers them through direct action. Meet Everyone with Art at Location and Time or M. E. A. L. T. Phase 1 is a mobilizable art exhibition with the long-term goal to meet the audience where they are and to offer an alternative to traditional person-to-person interaction and socializing.

M. …

Crying At Nothing But Colors, Maryalice Carroll

Graduate Theses and Dissertations

crying at nothing but colors is an installation of ceramic works that explores the abstraction of feelings, both physical and emotional. The installation itself is a house made out of tension cables that stretch wall to wall in the gallery space. Inside the house are 7 ceramic objects placed on wooden pedestals paired with tufted rugs.

Throughout this essay, I will describe the abstract ceramic objects as Beings. They are colorful and have textured glaze on the surface with a gloopy opalescent glaze oozing out of holes that cover each piece. They are an extension of myself. They are the …

As The Sun Yellows The Green Of The Maple Tree, Adam Fulwiler

Graduate Theses and Dissertations

As the Sun Yellows the Green of the Maple Tree is a body of paintings investigating communication, improvisation, play, and painting’s capacity for transformation.

Reflecting on my childhood spent with my brother, Austin, who experiences sensory differences due to autism, I establish a painted space that is both forcibly disjointed and meaningfully connected, invoking the uncertainty and complexity of perception and communication. Through chromatic nuance, physicality, representational ambiguity, and visual tempo, I invite the viewer into the act of slow looking—to encounter each work as a living, breathing, individual entity.

In the studio, I invent rules and aleatoric devices, mimicking …

Boring Magic, Madison Svendgard

Graduate Theses and Dissertations

Boring Magic encompasses an interest in labor, boredom, and exhaustion. Simultaneously, I am exploring what relief and escapism from these things look like. Escapism acts as the core of my work- what escapism looks like and what creates the need for escapism. I create narrative pieces that are always slightly removed from reality as a way to reflect on what I view as present-day dystopias. The worlds built to create this work are a combination of my lived experiences and invented characters and stories, which culminate in an alternate timeline set in the late 1990s and early 2000s. Relating to …

Invisible Until, Markeith Woods

Graduate Theses and Dissertations

“Invisible Until” explores my personal experiences while working full time at Tyson Foods in Pine Bluff, AR up until moving to Fayetteville for graduate school. The body of artwork comes from reflecting on past a present while drawing from inspiration from Jacob Lawrence, Kerry James Marshall, Jordan Casteel, and more. Using history as a tool to break down the American struggle I used conversations amongst my high school classmates to pull from their direct experiences to convey life and what it means to come from Pine Bluff. By using real people and their life events of trying to achieve progress, …

Investigating The Mechanics And Chemistry Of Sickle Polish Development, Justin Jared Dubois

Graduate Theses and Dissertations

This series of experiments is designed to understand the development and chemistry of sickle gloss. Sickles are common in the archaeological record and have long been studied for their eponymous “sickle gloss”. There is debate as to how this gloss is formed. Five experimental sickles containing flint and novaculite blades were used to harvest high and low moisture content rye and common fescue and associated field weeds. The differences in the development of sickle gloss were examined. High moisture content plants create thick, smooth fields of polish with undulating, billowing margins at a higher developmental speed. Low moisture content plants …

Validation Of Cfd Tornado Pressure On Building And Wind Field With Ttu Vortex Chamber Measurements, Sumit Verma

Graduate Theses and Dissertations

Structural failure of low-rise buildings is the root cause of higher number of casualties, death tolls and economic losses at the place of occurrence of tornadoes. Proper design of low-rise buildings in tornado-prone areas require accurate estimation of tornado-induced wind loads; however, exhaustive research to estimate the wind loads reliably on buildings during tornadic events is still lacking. Several studies have been carried out to investigate the magnitude of forces induced by tornado winds on buildings from experimental as well as computational side. However, the wind pressures obtained on the building from different experimental studies have shown significant variation from …

Development Of An Accelerated Life Testing Method For Reliability Assessment Of Wire Bonded Interconnects Subjected To Mechanical And Electromigratory Stresses, Whit Vinson

Graduate Theses and Dissertations

Power electronic advancement trends indicate that device power density will continue to increase as a result of increased power requirements and desired device form factor reduction in order to reduce weight and material costs and increase ease of integration into next-generation power systems. With these advancements come concerns regarding device reliability. The compounded effects of increased power density and form factor reduction in electrical conductors will yield amplified joule heating effects in addition to the already increasing device temperature profiles resulting from the incorporation of wide bandgap technology into power systems. Joule heating effects can lead to a variety of …

Concurrent Load And Construal On Planning, Maximilian Fey

Graduate Theses and Dissertations

Planning for the future is a necessary activity which spans across all aspects of an individual’s life. Concurrent cognitive load has been shown to hinder future planning, whereas concrete construal of events has been shown to increase planning efficacy. Interestingly, a limited literature speaks towards cognitive load inducing concrete construal. However, the two constructs predict differing outcomes on future planning therefore the interaction of cognitive load inducing a concrete construal is particularly interesting. The research study tested whether differing levels of concurrent cognitive load increase or decrease planning efficacy. The intention of the research was to elucidate whether cognitive load …

An Engineering And Economic Analysis Of The Implementation Of The Carbo Rock-It, Lydia Huck

Graduate Theses and Dissertations

The patented Carbo Rock-It system was developed to carbonate beverages for the craft brewing industry with the goal of reducing time, cost, and environmental impacts of the carbonation process. This research field tests, models, analyzes and optimizes the engineering and economic performance of a commercial-scale Carbo Rock-It placed in production at an operating brewery (Core Brewing and Distilling Co., Springdale, AR). Field tests indicated that the Carbo Rock-It was able to successfully carbonate twelve 120 BBL batches of Scarlet Letter Seltzer to 3.0 vol/vol while meeting all beverage quality and safety requirements. The Carbo Rock-It was able to reduce carbonation …

Something Like A Phenomenon: High Achieving Women Of Color And Experiences Of Mental Health Resource Utilization, Andrea Hampton Hall

Graduate Theses and Dissertations

The purpose of this study was to examine, explore, and understand the lived experiences of high-achieving Black and Latina women who had utilized mental health services in the last 18 months. The impact of discrimination and stigma is present today and may manifest itself within communities of color when these individuals attempt to access mental health services. The counseling field and counselor education programs are ethically responsible for integrating social justice counseling into coursework and practice. This informs educators and counselors of barriers that may influence and impact best practices for providing mental health services to communities of color. A …