Digital Commons Network^™

Investigation Of The Optical Properties Of Pbse/Pbx Nanocrystals For Photodetector Applications, Haley Ann Morris

Graduate Theses and Dissertations

Lead selenide and lead selenide/lead sulfide core/shell nanocrystals were investigated for use in near infrared photodetectors. A colloidal synthesis method was used for both the core and core/shell configurations. The lead sulfide shell was examined in order to mitigate oxidation of the nanoparticle surface. Absorbance and photoluminescence spectra were measured at room temperature and 77 K, respectively. Transmission electron microscopy images were also obtained to confirm crystallography and size. Bulk lead selenide was simulated in WIEN2k utilizing the linear-augmented plane wave method of solving density functional theory to better understand the electronic structure of PbSe. The crystal structure, electron density, …

A Gis Approach To Modeling Groundwater Levels In The Mississippi River Valley Alluvial Aquifer, Josef Orion Lilly

Graduate Theses and Dissertations

Groundwater depletion, a subject of growing concern for a significant portion of Arkansas, may lead to future economic challenges for the Arkansas Delta region. The Mississippi River Valley Alluvial Aquifer is the uppermost aquifer and features the largest groundwater capacity in the Mississippi Embayment Aquifer System. The Mississippi River Valley Alluvial Aquifer, commonly referred to as the “alluvial aquifer”, spans 53,000〖 km〗^2 underlying portions of Arkansas, Kentucky, Louisiana, Mississippi, Missouri, Illinois, and Tennessee. As the alluvial aquifer trends southward for approximately 250 miles alongside the Mississippi River, its geographical extent ranges from 50 to 125 miles wide. There is a …

Ecological Approaches To Modernism, The U.S. South, And 20th Century American Literature, Justin Ford Tinsley

Graduate Theses and Dissertations

This project seeks to draw from the insights of the emerging scholarly discipline known as ecocritism, study of the relationship between human and nonhuman in all arts and in all diverse forms, and apply them to the study of a specific regional art, that of the U.S. South. As an interrogation of the human / nonhuman binary, ecocriticism is intrinsically intertwined with the concept of place. Southern studies—having long explored the diversity (in terms of both human experience and geographical terrain) characterizing the region—offers ecocriticism a ripe testing ground for theoretical mergers and analytic applications. Both fields celebrate hybridity, multiplicity, …

How Select Groups Of Preservice Science Teachers With Inquiry Orientations View Teaching And Learning Science Through Inquiry, Peggy Diana Ward

Graduate Theses and Dissertations

Although hailed as a powerful form of instruction, in most teaching and learning contexts, inquiry-based instruction is fraught with ambiguous and conflicting definitions and descriptions. Yet little has been written about the experiences preservice science teacher have regarding their learning to teach science through inquiry. This project sought to understand how select preservice secondary science teachers enrolled in three UTeach programs in Arkansas conceptualize inquiry instruction and how they rationalize its value in a teaching and learning context. The three teacher education programs investigated in this study are adoption sites aligned with the UTeach Program in Austin, TX that distinguishes …

Apparel Design Process: Shifting The Basic Pattern Block Into A New Framework To Fit The Demands Of Post Double Mastectomy Women, Shan Gao

Graduate Theses and Dissertations

Breast cancer is a leading cancer among women today. Mastectomy is one of the most common paths for breast cancer prevention and treatment. However, this treatment path can cause noticeable body changes around the woman’s bust area. Recently more and more post mastectomy women are deciding to live without breast reconstruction surgery. This decision referred to as “going flat” or “living flat.” Due to the changed bodies and a lack of information on functional and aesthetic concerns related to clothing, clothing selection becomes difficult for post mastectomy women who choose to “live flat.”

The purpose of this study was to …

Perceptions Of Division I Athletic Director Career Paths, Eric A. Wood

Graduate Theses and Dissertations

There is increased information about the profile of current collegiate athletic directors as it relates to education, age, race, and gender. However, there is a gap in the knowledge of the career paths of the modern day Division I collegiate athletic director position compared to the athletic directors studied over 20 years ago. There is also a gap in the knowledge of the skills necessary to be an effective athletic director from the perspective of Division I athletic directors. The purpose of this study was to use the Perceptions of Division I Athletic Director Career Paths (PADCP) scale to determine …

Growth Of Gesn And Gepb Alloy Films Using Thermal Evaporator, Hakimah Alahmed

Graduate Theses and Dissertations

Silicon is the most important semiconductor material used in microelectronic devices. As the number of transistors keep doubling every 24 months (Moore’s law), transistors continue scaling down in size, electrical interconnect is reaching its limits to keep up with the scaling down rate in integrated circuits. These limitations are related to interconnect density and power consumption. Hence, replacing electrical interconnect with optical interconnect on the chip or between chips has the ability to overcome these limitations. However, silicon has poor light emitting efficiency, and other substitutes such as III-V materials are not suitable due to high cost, lattice mismatch, and …

Agro-Climatic Change, Crop Production And Mitigation Strategies-Case Studies In Arkansas, Usa And Kenya, John Westley Magugu

Graduate Theses and Dissertations

Although climate change impacts vary geographically and temporally, studies at local levels are not readily available for stakeholders to better understand how their local communities would be affected and what remedial measures could be more effective in their local contexts. This dissertation has examined climate change and its impacts in two different local contexts: eastern Arkansas in the USA and Nyando in Kenya. The first part of this dissertation develops agro-meteorological indicators and examines the relationship between agro-meteorological indicators and crop yields in eastern Arkansas between 1960 and 2014. Results reveal that temperature based indicators were more strongly correlated to …

Effectiveness Of The Arkansas 4-H Atv Safety Training Course, Jesse Bocksnick

Graduate Theses and Dissertations

In response to popularity of ATVs in Arkansas and youth ATV accident rates, the Arkansas 4-H program established an ATV safety training program in 2008. The program has educated 1,500 youth in Arkansas about basic concepts of safe ATV operation in response to youth accident rates. The course covered proper equipment, laws, proper riding, and handling techniques. The program has not been evaluated. The study was to evaluate participants’ knowledge levels prior to participation in the program and after receiving instruction and hands-on ATV operation training, and to determine if Standard Course and S-Course participants’ knowledge scores were different. The …

Essays On Monetary Policy Rules And Inflation Dynamics, Saad Ahmad

Graduate Theses and Dissertations

There has been a growing trend to utilize nonlinear models to analyze key issues in monetary policy and international macroeconomics. Using traditional linear models to understand nonlinear relationships can often lead to inaccurate inference and erroneous policy recommendations. The three essays in this dissertation explore nonlinearity in the Federal Reserve’s policy response as well as between a country’s inflation dynamics and integration in the global economy. My aim in accounting for potential nonlinearity is to get a better understanding of the policy makers’ opportunistic approach to monetary policy and evaluate the inflation globalization hypothesis, which basically predicts that global factors …

The Impact Of Crop Insurance On Indonesian Rice Production, Zaura Fadhliani

Graduate Theses and Dissertations

This study builds a theoretical model of the yield-based MPCI crop insurance policy for a risk averse rice farmer in Indonesia and presents the comparative statics analysis of policy variables on yield through the coupling, wealth, and insurance effects. Moreover, Using yield data from 1979 to 2014 for the Tuban Regency, this study applies numerical optimization to the model and simulates the effects of different policies on input use, certainty equivalents, indemnity payment, and premiums. The theoretical analysis shows that no coupling effect exists for change in the coverage level, while a coupling effect exists for change in the subsidy …

Experiences Of Agricultural Education Preservice Teachers Engaging In Critical Friendships, Sable Sellick

Graduate Theses and Dissertations

Like educators in other disciplines, agricultural education preservice teachers must find ways to improve as teachers using methods such as reflection or peer observation. Critical friendship combines both, promoting reflection through the use of a critical friend who observes an individual’s teaching and provides constructive criticism to help the individual advance their practice. This qualitative study sought to use the critical friendship concept to assist agricultural education preservice teachers in reflecting on their teaching techniques. Participants were randomly assigned to one of two groups; one group selected a critical friend in agricultural education, and the other group selected a critical …

Essays On Optimization And Modeling Methods For Reliability And Reliability Growth, Thomas Paul Talafuse

Graduate Theses and Dissertations

This research proposes novel solution techniques in the realm of reliability and reliability growth. We first consider a redundancy allocation problem to design a system that maximizes the reliability of a complex series-parallel system comprised of components with deterministic reliability. We propose a new meta-heuristic, inspired by the behavior of bats hunting prey, to find component allocation and redundancy levels that provide optimal or near-optimal system reliability levels. Each component alternative has an associated cost and weight and the system is constrained by cost and weight factors. We allow for component mixing within a subsystem, with a pre-defined maximum level …

Evaluation Of Agricultural Policy In The Dairy Sector In Kosovo And Efficiency Analysis At The Farm Level, Egzon Bajrami

Graduate Theses and Dissertations

This thesis consists of two studies on the dairy sector in Kosovo. The first study evaluates the effect of the Subsidy per Head Scheme (SPHS) on increasing production, land use, gross income and number of dairy cows on dairy farms in Kosovo. Results from the Propensity Score Matching (PSM) approach using four alternative matching algorithms revealed that SPHS has not had any impact on increasing land use, gross income or the number of dairy cows per farm. Furthermore, SPHS had a negative impact on decreasing land use and number of cows for the participating dairy farmers in the program. In …

Long-Term Supplementation With Leucine Does Not Prevent Development Of Obesity In Rats Fed A High-Fat Diet, Dameon Smith

Graduate Theses and Dissertations

Excess dietary fat consumption has been implicated in the development of obesity and diabetes. Obesity can be characterized by a disproportionate increase in fat mass compared to lean body mass. However, if muscle mass can be increased or maintained in obesity, this may facilitate weight loss by increasing the body’s overall metabolic capacity. Historically, supplementation with the branched-chain amino acid leucine has been shown to increase muscle protein synthesis via the protein kinase mTORC1. Recent studies suggest that supplementation with leucine also has the potential to reduce weight gain and fat deposition in high-fat fed, obese mice. The objective of …

Genetic Basis Of Biosynthesis And Cytotoxic Activity Of Medicago Truncatula Triterpene Saponins, Brynn Kathleen Lawrence

Graduate Theses and Dissertations

Saponins are a large family of specialized metabolites produced in many plants. They can have negative effects on a number of plant pests and are thought to play a role in plant defense. With current and possible future uses in industry and agriculture, saponins have also been shown to be hypocholesterolemic, hypoglycemic, immunostimulatory, antioxidative, anti-inflammatory, and cytotoxic. In spite of their usefulness, our understanding of the genetic basis for saponin biosynthesis is still incomplete. We generated recombinant populations with parents from genetically distinct accessions of Medicago truncatula, with either high or low accumulation and varying profiles of saponins. Primers for …

Characterization Of Histone Mutants Associated With Mitotic Defects In Saccharomyces Cerevisiae, Md Riajul Hossain

Graduate Theses and Dissertations

Nucleosomes, the basic unit and the building blocks of chromatin have an essential role in the tight packaging of DNA into higher order chromatin. Work from our lab and others have provided information on the contributions of different histone proteins and specific domains within the nucleosome made to create the centromeric chromatin structure required for normal chromosome segregation during mitosis. The DNA entry/exit site is a particular region of the nucleosome where histone H2A, H3 and H4 form critical interactions that appear to be essential for the association of Sgo1, a tension sensing protein that monitors kinetochore-microtubule attachment. In our …

Social Learning Remixed: Peer-Based Learning And Social Status In An Online Community Of Practice, Christopher Erin Mikkelson

Graduate Theses and Dissertations

People have engaged in peer-to-peer learning within communities of practice (CoPs) for centuries. Thanks to web 2.0 technology, people in the 21st century can now learn together and enact Social status even if they have never met face-to-face. Online communities of practice have since formed around a wide variety of activities, one of which is remixing. Remixing is defined as combining or editing existing materials to produce something new, but leaving each part recognizable as a separate entity. Remixing has recently been recognized as form of digital literacy because users must understand each component to make a good remix. Much …

Black Male Emerging Adults: Investigating Inequalities In Adult Transitions, Social Learning, And Criminality, De Andre' Terrell Beadle

Graduate Theses and Dissertations

Emerging adulthood is a life stage that developed as a result of numerous macro-structural changes in recent decades (Arnett 2015), and which has implications for life course criminality and identity formation (Massoglia & Uggen 2010). Much research has been done in the area of the new life stage known as “emerging adulthood,” however little to no research has been done on how emerging adulthood relates to or changes classic findings in criminology, especially about the importance of disadvantages embedded in racial inequalities. This mixed method study analyzes data from the National Study of Youth and Religion (NSYR) to examine Social …

Incorporating A New Class Of Uncertainty In Disaster Relief Logistics Planning, Emre Kirac

Graduate Theses and Dissertations

In recent years, there has been a growing interest among emergency managers in using Social data in disaster response planning. However, the trustworthiness and reliability of posted information are two of the most significant concerns, because much of the user-generated data is initially not verified. Therefore, a key tradeoff exists for emergency managers when considering whether to incorporate Social data in disaster planning efforts. By considering Social data, a larger number of needs can be identified in a shorter amount of time, potentially enabling a faster response and satisfying a class of demand that might not otherwise be discovered. However, …

Beer For Brohood: A Laboratory Simulation Of Masculinity Confirmation Through Alcohol Use Behaviors In Men, Jessica Lauren Fugitt

Graduate Theses and Dissertations

Alcohol use is a widespread behavior that may be associated with negative consequences, especially for men. Research suggests that individuals are motivated to maintain in-group status by engaging in behaviors prototypical of the in-group when group status has been challenged, and that men are particularly likely to do this when masculine in-group status is threatened. This study investigated masculine drinking behaviors through Social and individual lenses, examining the impact of group identification and individual differences on alcohol consumption rates after a simulated gender threatening situation in a bar laboratory. Sixty-five male students (ages 21-29; 74% Caucasian) were given the chance …

Trend Analysis Of Water Quality In Northwest Arkansas Streams Reflects Changes In The Watershed, Zachary Paul Simpson

Graduate Theses and Dissertations

Watershed export of nutrients, sediments, and chemicals impacts receiving waters. Changes within the watershed (e.g., anthropogenic or climatic) can alter the transport of constituents in streams. Stream monitoring is crucial for understanding these effects. This study developed a potential improvement to flow-adjusting constituent concentrations in streams, an important step of analyzing monitoring data in lotic systems for trends. The method incorporates a K-fold cross-validation procedure to optimize a model explaining the relationship between the concentration and streamflow, thus providing a valuable tool to researchers in water quality. Additionally, two case studies were conducted on watersheds located in northwest Arkansas using …

Biocentrism In Environmental Ethics: Questions Of Inherent Worth, Etiology, And Teleofunctional Interests, David Lewis Rice Iii

Graduate Theses and Dissertations

Some biocentrists argue that all living things have "inherent worth". Anything that has inherent worth has interests that provide a reason for why all moral agents should care about it in and of itself. There are, however, some difficulties for biocentric individualist arguments which claim that all living things have inherent worth.

Some biocentrists maintain that all living things have inherent worth and that artificial living things do not because the former, but not the latter, have interests by recourse to their natural selection etiology. Some also argue that synthetic forms of life do not have moral standing because they …

Assessment Of The Level Of Protection Against Coccidiosis In Broiler Breeders Conferred By A Live Anticoccidial Vaccine, And Its Influence On Early Growth And Development., Muhammed Shameer Abdul Rasheed

Graduate Theses and Dissertations

Coccidiosis continues to be a great challenge to the poultry industry all over the world and in broiler breeders vaccination with live oocysts of Eimeria has been widely adopted as a control measure. Broiler breeders are usually subjected to feed restriction during their early growth however no studies have been undertaken on the effects of vaccination in birds whose feed has been restricted in this manner. The objective of this study was to assess the level of protection acquired by broiler breeder chickens when immunized at day-old with live eimerian oocysts and given a restricted diet. Effects upon growth and …

Effect Of Hydration Status On Thermoregulatory Responses In Non-Obese And Obese Males, Matthew Tucker

Graduate Theses and Dissertations

During heat stress the human body thermoregulates via cutaneous vasodilation and sweating. Hypohydration can impair thermoregulatory responses that stem from the central nervous system (CNS), but it is unknown if impairments also occur post-synaptically in the microcirculation. Moreover, obese individuals may have impaired thermoregulation, possibly due to microvascular dysfunction. Purpose: The purpose of these studies was two-fold: 1) to determine if obese (OB) individuals exhibit impairments in thermoregulatory responses during exercise heat-stress (centrally-mediated) and intradermal infusion of vasoactive substances (peripherally-mediated) versus non-obese (N-OB), and 2) to determine if hypohydration subsequently affects these thermoregulatory responses differently between groups. Methods: Twenty-one healthy, …

An Investigation Of Short-Term Plasticity In Human Motor Cortex, Matthew Alan Gannon

Graduate Theses and Dissertations

Transcranial magnetic stimulation (TMS) produces a transient magnetic field that activates underlying cortical tissue by eliciting an electrical discharge of the neurons in the targeted area. Repetitive TMS (rTMS) uses patterns of repetitive TMS pulses and has been reliably shown to produce changes in the state of cortical excitability outlasting the time of stimulation. One such protocol that has demonstrated states of increased excitability is intermittent theta burst stimulation (iTBS). This method applies high-frequency bursts (50Hz) of pulses every 200 ms in trains of ten bursts. The effects of and differences between rTMS protocols have been investigated since gaining popularity …

Young Adult E-Cigarette Exposure: Implications For Policy And Prevention, Monica Page Daniel Dobbs

Graduate Theses and Dissertations

Objective. The purpose of this study is to examine factors associated with e-cigarette use among college students to better understand their behavior. Using Ajzen’s Reasoned Action Approach, this study sought to better understanding the influence of attitudes, Social norms, and perceived behavioral controls (PBCs) on college students’ intention to try e-cigarettes (even one puff) in the next 30 days.

Methodology. This study employed three phases for a mixed methods design that took place between December 2015 and April 2016. Phase 1 used Middlestadt’s salient belief elicitation procedure to capture responses through an open ended survey (n=58). Phase 2, a pilot …

Design And Analysis Of An Asynchronous Microcontroller, Michael Hinds

Graduate Theses and Dissertations

This dissertation presents the design of the most complex MTNCL circuit to date. A fully functional MTNCL MSP430 microcontroller is designed and benchmarked against an open source synchronous MSP430. The designs are compared in terms of area, active energy, and leakage energy. Techniques to reduce MTNCL pipeline activity and improve MTNCL register file area and power consumption are introduced. The results show the MTNCL design to have superior leakage power characteristics. The area and active energy comparisons highlight the need for better MTNCL logic synthesis techniques.

Asynchronous Data Processing Platforms For Energy Efficiency, Performance, And Scalability, Liang Men

Graduate Theses and Dissertations

The global technology revolution is changing the integrated circuit industry from the one driven by performance to the one driven by energy, scalability and more-balanced design goals. Without clock-related issues, asynchronous circuits enable further design tradeoffs and in operation adaptive adjustments for energy efficiency. This dissertation work presents the design methodology of the asynchronous circuit using NULL Convention Logic (NCL) and multi-threshold CMOS techniques for energy efficiency and throughput optimization in digital signal processing circuits. Parallel homogeneous and heterogeneous platforms implementing adaptive dynamic voltage scaling (DVS) based on the observation of system fullness and workload prediction are developed for balanced …

Audit-Related Services And Audit Quality: Evidence From Benefit Plan Audits, Jaclyn Prentice

Graduate Theses and Dissertations

The following study examines a material but less understood component of the public audit marketplace, namely the provision of “audit-related” services to financial statement audit clients. I use the benefit plan audit service setting to examine the company and benefit plan characteristics associated with auditor selection and the impact of audit-related services on financial statement audit quality. I provide market evidence of distinct shifts in the use of the same audit firm for the financial statement audit and other audit-related services over time as well as characteristics of the choice of auditors. I then test whether having the same audit …