Digital Commons Network^™

Hybrid Two Dimensional Quantum Devices, Joshua Patrick Thompson

Graduate Theses and Dissertations

This thesis describes measurements on hybrid material systems involving two dimensional (2D) materials and phenomena along with the development of a small, hermetically sealed cell. The hermetic cell is designed to assist with analyzing sensitive 2D materials outside of an inert environment. When working with van der Waals materials that are especially sensitive to oxygen or water, it can be difficult to identify usable thin flakes without exposing them to air. To help preserve materials for analysis in air, a capsule was designed that isolates the material in an inert environment. Although the capsule is hermetically sealed, the encapsulated material …

Diversifying Woolf’S Room: Private Spaces And Creativity In The Works Of Willa Cather, Kate Chopin, Gayl Jones, And Alice Walker, Ebtesam M. Alawfi

Graduate Theses and Dissertations

There is a divergence between Woolf’s vision of private physical spaces necessary for creating art and that of some feminists of color such as Alice Walker, Ortiz Cofer, and Gloria Anzaldua. Both Woolf and these contemporary scholars agree on the importance of physical spaces for female artists. However, they disagree on the nature of these spaces. Woolf’s private physical space is a room with a lock on the door whereas these writers’ room is the kitchen table, the bus, or the welfare line. Walker and like-minded writers challenge the narrowness of Woolf’s room because her locked room is a luxury …

Listening To Voices Of Latinx Immigrants In Rural America, Jacqueline Smith

Graduate Theses and Dissertations

The purpose of this phenomenological qualitative study was to capture and gain an understanding of Latinx immigrants’ lived experiences during their transitions from their native countries to rural Arkansas. Using purposeful criterion-based sampling, the population of interest was five Latinx immigrant students and families who migrated from their native countries to the state of Arkansas. The analytic strategy included a single-case model of each family’s transcription, two-case model, cluster analysis to identify likeness, document portrait, and subtheme development. The structural descriptions that formed the essence of the experience resulted in three themes: education, migration, and emotional experiences. The three overall …

Longitudinal Monitoring Of Tumor Response To Immune Checkpoint Inhibitors Using Diffuse Optical Spectroscopy, Joel Isaac Rodriguez Troncoso

Graduate Theses and Dissertations

Immune checkpoint drugs have completely changed the way people treat metastatic melanoma and non-small-cell lung cancer. While the impacts of these immunological checkpoints and their suppression on T cell function are well characterized, their consequences on the tumor microenvironment are not. In a CT26 mouse colorectal cancer model, we employed diffuse reflectance spectroscopy to track in vivo tumor microenvironmental alterations in response to immune checkpoint inhibitors. On three separate days, animals bearing CT26 tumor xenografts were given anti-PD-L1, anti-CTLA-4, a combination of both inhibitors, and isotype control. Within the first 6 days, monotherapy with either anti-PD-L1 or anti-CTLA-4 resulted in …

Development And Evaluation Of Models For Hatchery-Mediated Infection Of Neonatal Broiler Chicks, Brittany Danielle Graham

Graduate Theses and Dissertations

Formaldehyde fumigation has been used to control the microbial load in commercial hatch cabinets. The hatch cabinet environment promotes replication and dissemination of both apathogenic and pathogenic microorganisms. As the microbial load increases during the hatching phase, formaldehyde eliminates airborne microorganisms circulating in the hatch cabinet environment. Due to the hazardous properties of formaldehyde, non-toxic alternatives to formaldehyde fumigation to control the microbial bloom in hatch cabinets are needed. The objectives of the present dissertation were to develop challenge models using singular or multiple microorganisms associated with the microbial bloom to simulate contamination that occurs in commercial hatch cabinets. Initially, …

Incorporation Of Zinc In Pre-Alloyed Cuin[Zn]S2/Zns Quantum Dots, Jean Carlos Morales Orocu

Graduate Theses and Dissertations

Since the early 2000s heavy-metal-free quantum dots (QDs) such as CuInS2/ZnS have attempted to replace CdSe, their heavy-metal-containing counterparts. CuInS2/ZnS is synthesized in a two-step process that involves the fabrication of CuInS2 (CIS) nanocrystals (NCs) followed by the addition of zinc precursors. Instead of the usual core/shell architecture often exhibited by binary QDs, coating CIS QDs results in alloyed and/or partially alloyed cation-exchange (CATEX) QDs. The effect that zinc has on the properties of CIS NCs was studied by incorporating zinc during the first step of the synthesis. Different In:Cu:Zn ratios were employed in this study, maintaining a constant 4:1 …

Evaluation Of Two Neonatal Challenge Models For Broiler Chickens And Their Effects On Early Performance Parameters, Callie Selby

Graduate Theses and Dissertations

Formaldehyde fumigation in poultry hatch cabinets has been utilized for sanitation of hatching eggs for over a century. Formaldehyde is utilized to minimize pathogenic microbes on the surface of the egg as well as the microbial bloom during the hatching process. While formaldehyde is effective, its use is regulated in the United States and Europe due to its carcinogenic nature. Formaldehyde has been shown to damage the cuticle of the egg, cause embryonic death, and damage the epithelial lining of the respiratory tract of freshly hatched chicks, predisposing them for respiratory infection. Alternatives for formaldehyde fumigation must be identified and …

Preliminary Development Of The Dialysis-Membrane-Based Passive Biocide Delivery System For Spacecraft Water Recovery Units, Rogelio Elias Garcia Fernandez

Graduate Theses and Dissertations

The purpose of this investigation is to explore the capabilities of a dialysis-membrane-based system for the in-line dosing of silver ions to treated water in spacecraft water recovery units. The spacecraft environmental control and life support system community (ECLSS) are interested in adopting silver ions as a biocide in future spacecraft water recovery processes since silver ions are effective biocide at concentrations that humans can safely consume. The system has been designed following the configuration of the Water Processor Assembly (WPA) aboard the International Space Station. In this configuration, silver ions have to be added at the last step in …

Detrital Zircon U-Pb Geochronology Of Upper Mississippian Siltstone, Oklahoma And Arkansas, Linnea Johnson

Graduate Theses and Dissertations

Although Upper Mississippian strata have been characterized extensively using lithostratigraphy, sequence stratigraphy, and biostratigraphy across the North American midcontinent, the origin of the silt comprising the Meramec STACK (Sooner Trend Anadarko Basin, Canadian and Kingfisher counties) reservoirs of the Anadarko Basin in west-central Oklahoma and age equivalent units is not well understood, despite its economic importance as an unconventional petroleum reservoir. Previously published models have variously invoked fluvial, marine, and aeolian sediment transport for Upper Mississippian siltstone present along the paleo-shelf edge of the Laurentian craton. This study uses detrital zircon U-Pb geochronology and grain morphology, handheld x-ray fluorescence (hXRF) …

The Evolution Of Defeaters: A Taxonomy, Erica Nicolas

Graduate Theses and Dissertations

It has been widely argued that reasons for a belief come in degrees but not much literature has focused on the idea that defeaters for justification toward those beliefs also come in degrees. The aim of this paper is to explore epistemic defeasibility and construct a taxonomy for epistemic defeaters. This paper argues that epistemic defeaters undergo an evolutionary process before becoming what they are commonly labeled, such as rebutting and undercutting. I argue that within some stages of this process, there can be different degrees of defeat. This paper focuses on defeaters for justification, expands on the account of …

Development Of Aptamer Rolling Circle Amplification Platform As A Vaccine Adjuvant To Control Salmonella In Broiler Chickens, Abigeal Iyabode Omolewu

Graduate Theses and Dissertations

Salmonella has been a major source of concern in public health and food industry. It is the cause of gastrointestinal illness and fever called salmonellosis. Severe cases of salmonellosis have resulted in hospitalization and even death around the world. Salmonella can be found in the intestinal tract of animals including chickens and can be transmitted to human through contaminated food. Hence, it is highly important to find ways of reducing the transmission of Salmonella from chickens to humans. This work is focused on the control of Salmonella in broiler chicken through the development of novel vaccine adjuvant. Two different aptamer …

Just Benjamin, Paige R. Murphy

Graduate Theses and Dissertations

This documentary short film is about a now 30-year-old transgender man telling his story of growing up queer in a small Arkansas town, from being outed as a lesbian in high school, to ultimately being accepted as a trans man by members of his military and biological families. Benjamin “Benji” Davis grew up in the small town of Friendship, Arkansas, enlisted in the U.S. Army shortly after high school and served for six years, then came back to Arkansas and primarily lived in Little Rock until he moved to Denver, Colorado this fall. The documentary is structured linearly both with …

Development And Characterization Of Monolayer And Sub-Monolayer Intermediate Band Solar Cells, Najla Alnami

Graduate Theses and Dissertations

Intermediate band solar cell (IBSC) is a new generation solar cell that is designed to overcome the main limitation of solar cell power conversion efficiency, which is the non-absorption of low photon energy. Experimental efforts towards fabricating high efficiency and low cost IBSC have not met the predictions of theoretical analysis. Existing implementations of the IBSC design using conventional Stranski-Krastanov (S-K) quantum dots (QDs) have resulted in a degradation in the solar cell device characteristics, which has been found to be caused by recapturing or trapping of excess carriers, low intermediate band material absorption, and increased recombination in the solar …

Gaas Growth On Sapphire Substrates (C And R Plane) For Integrated Microwave Photonics (Imwp), Samir Kumar Saha

Graduate Theses and Dissertations

The microwave signal processing in the optical domain creates new opportunities for information and communication technology (ICT) and networks by increasing speed, bandwidth, and processing capability. IMWP incorporates the functions of microwave photonics components/subsystems in monolithic or hybrid photonic circuits to meet future needs. Sapphire platforms have the potential to integrate all-in-one, for instance, light source, analog signal processing, light detection, CMOS control circuit, silicon on sapphire to achieve high-performance, low-cost mixed-signal optical links etc. Molecular beam epitaxy (MBE) has been used to grow GaAs on sapphire substrates to integrate optoelectronic devices in the same platform.

The initial stage of …

Symbolism Or Substance: Factors Influencing Campus Messaging Decisions And Their Alignment With Institutional Values, Laura Herzog Jacobs

Graduate Theses and Dissertations

Historically, institutions of higher education (IHE) have been cautious and slow in making changes. Yet in today’s fast-paced and dynamic world of content availability and information flow generated by 24-hour news cycles and the ubiquity of social media present a challenging reality for colleges and universities in their public relations and communications approaches (Sands & Smith, 2000). Creating a harmonious and agile approach to managing these responsibilities against the backdrop of an incessant flow and public demand for information, including responses to national events often with seemingly little or no connection to the institution, suggested a need to examine the …

The Effects Of Watching Text-Relevant Video Segments On Reading Comprehension Of Culturally Unfamiliar Texts With Adult English Language Learners Supported By The Schematic Information-Processing (Sip) Model Of Reading Comprehension, Amirreza Karami

Graduate Theses and Dissertations

The purpose of this mixed-methods sequential explanatory study was to investigate the effects of watching text-relevant video segments on reading comprehension of a culturally unfamiliar text when technical words are present or absent. Therefore, 44 adult English Language Learners (ELLs) with higher-intermediate to advanced English language proficiency levels from the Universidad Autónoma de Santo Domingo (UASD) School of Languages located in the Dominican Republic were chosen and randomly assigned to two different groups: control vs. experimental.

First, the researcher compared two different types of reading instruction—traditional text-based vs. video-based reading instruction supported by the Schematic Information-Processing (SIP) model of reading …

Teacher And Staff Perception Of School Climate: A Case Study, Michael Shane Hampton

Graduate Theses and Dissertations

The purpose of this study is to determine how different public-school teachers and staff perceive school climate at an achieving public middle school. The research sought to find relationships between teacher sub-groups and other staff members, and how they perceived the school climate, either negatively or positively. The researcher believed that there would be a positive perception of school climate, which coincided with high student achievement. Additionally, it was believed that there would be no relationship between teacher types or demographics, and how the climate would be perceived among the different groups. This paper also presents a review of the …

Experimental And Computational Studies Of Electron Rich Alkenes, Alexa May

Graduate Theses and Dissertations

Thermal homolysis is one of the most fundamental reactions in organic chemistry. Free radical reactions are generally initiated by light or a radical initiator to generate the first radical, which can then propagate or terminate the reaction. Direct thermal homolysis requires no chemical initiators, just an increase in temperature depending on the homolysis energy.There are few studies of direct radical homolysis in complex systems or under mild conditions. The reactions involving C-N homolysis under mild conditions are reported in Chapter 1. Though the authors do not all propose a radical mechanism, we believe they can all be explained by a …

Investigation Of Histomoniasis Prevention In Poultry, Lesleigh Beer

Graduate Theses and Dissertations

Histomonas meleagridis is the etiological agent of histomoniasis, also commonly known as blackhead disease. This protozoal disease of poultry is detrimental to turkeys with flock mortalities often reaching 80-100%, although other gallinaceous birds are susceptible. Since the voluntary removal of nitarsone in 2015, the poultry industry is suffering with no approved prophylactics, therapeutics, or vaccines for this disease. The objectives of this dissertation were to evaluate multiple methods for prevention or control of histomoniasis, including dietary chemoprophylaxis and vaccination. Specifically, this research evaluated quinine as a chemoprophylactic candidate (Chapter 3) or live-attenuated H. meleagridis as vaccine candidates (Chapter 4) in …

Site-Specific Effects Of Lysine Acetylation On Aminoacyl-Trna Synthetase, Hao Chen

Graduate Theses and Dissertations

Aminoacyl-tRNA synthetases (AARSs) are an ancient and highly conserved family of enzymes which can catalyze a two-steps aminoacylation reaction to charge tRNAs with their cognate amino acids, thus playing crucial roles in ribosomal protein synthesis. Naturally, the accurate amino acids and tRNA recognition of these synthetases are essential to the fidelity of translation process. To assure the correct recognition, some of these synthetases have evolved with an editing function to help remove the mischarged tRNAs. In addition to these functions, AARSs are also involved in various biological processes ranging from transcription to translation. Currently, a series of proteomic studies have …

Optimization And Resistance Mitigation Of Dicamba And Glufosinate In Xtendflex® Crops, Grant Lawson Priess

Graduate Theses and Dissertations

The commercial launch of XtendFlex® crops enabled the use of dicamba, glufosinate, and glyphosate in-season. Utilizing herbicides that target different sites of action within troublesome weeds has been a tactic proposed to mitigate the likelihood of target-site resistance evolving; however, if interactions of the herbicides are detrimental to control of weedy species the likelihood of metabolic resistance increases. The objective of this research was to: 1) optimize efficacy and economic benefits of dicamba, glufosinate, and glyphosate; 2) characterize any interactions that were observed; 3) understand the mechanisms responsible for the reductions in weed control; 4) attempt to overcome interactions that …

Analysis Of Bacteriorhodopsin Suspended In A Bilayer Lipid Membrane, Moath Alhejji

Graduate Theses and Dissertations

The bacteriorhodopsin protein’s unique characteristic of proton pumping can convert light energy to electric energy. The aim of this research was to generate photocurrent using bacteriorhodopsin in a bi-layer lipid membrane. Lipid monolayer and bilayer were formed using painting and folding methods, respectively. Capacitance and resistance of the lipid membranes were measured and used to validate the best methodology. My results show that the folding method is more efficient in incorporating Bacteriorhodopsin. The photocurrent was generated by illuminating a green laser (532 nm) on the bilayer lipid membranes. The patch clamp electrophysiology technique was used to apply voltage across the …

Stress Among Ncaa Division Ii Head Coaches, Dee Gerlach

Graduate Theses and Dissertations

The purpose of this quantitative study was to identify factors that create stress among head coaches at the National Association Athletic Association Division II level. Data was collected through a demographic questionnaire and the Coaching Issues Survey (CIS), a tool used to measure specific factors that may create stress among coaches. The factors of the CIS include four subscales: Athlete-Concerns, Time-Role, Program-Success, and Win-Loss. Participants (N=416) consisted of head coaches representing the following sports: baseball, men’s basketball, women’s basketball, men’s golf, women’s golf, men’s and women’s golf, softball, women’s tennis, and men’s and women’s tennis. The independent variables for this …

Efficacy Of Selected Powdered Floor Treatments And Turmeric Rhizome Powder Against Salmonella, E. Coli, And L. Monocytogenes On Polyurethane-Concrete Flooring Material Carriers, Robert Sidney Fuller

Graduate Theses and Dissertations

The flooring in a food processing environment can become contaminated with pathogenic bacteria in many ways including foot and equipment traffic, incoming materials, and drain backups. Turmeric (Curcuma longa L.) rhizome powder and seventeen other commercially available powdered floor treatments with a variety of active ingredients including quaternary ammonium compounds (QAC), sodium percarbonate and similar perhydrates (SPC), urea, and borax, were investigated for reducing the levels of pathogens on flooring thereby reducing the risk of cross-contamination from the floor to food contact surfaces. Some of the commercially available floor treatments were Environmental Protection Agency (EPA) registered antimicrobials while others were …

Investigation Of Iron-Nickel Films Based Catalysts: Controlling Hydrogen Evolution Reaction (Her) Through An Electrode-Electrolyte Engineering Approach, Sergio Ivan Perez Bakovic

Graduate Theses and Dissertations

Electrochemical energy conversion technologies need to be economically viable in order to be adopted. Earth-abundant transition metals (i.e., Fe, Co, and Ni) have attracted attention due to their high availability, low cost, and catalytic characteristics that are in many cases found in and exploited by nature. Herein, we synthesize FexNi100-xOy electrocatalyst films and study how the electrocatalyst-electrolyte interactions alter the hydrogen evolution reaction (HER).In this work, FexNi100-xOy films were synthesized to study the composition, chemical state, and morphology. Characterization results provided a well-established electrocatalyst film platform to then proceed with electrochemical evaluations. The effects of the electrode composition and electrochemically …

A Case Study Of Eastern Region Arkansas Promise Participants And Their Expectations For The Future, Robin Freeman

Graduate Theses and Dissertations

The purpose of this study was to develop an in-depth understanding of how Eastern Arkansas youth with disabilities and their parents describe their expectations for the future, after participating in the Arkansas PROMISE program. The study sought an understanding of how participants viewed themselves and their expectations for the future, for employment, for participation in higher education, for independent living, and for future financial support. The research used a case study approach, interviewing five students and five parent participants. Participants were asked a series of questions to get an understanding of their experiences, their expectations for the future, and their …

Catalytic Activity Of Molybdenum-Dioxo Complexes, Randy Tran

Graduate Theses and Dissertations

This dissertation details the development of rationally designed dioxomolybdenum catalyst active for deoxydehydration (DODH), the net reduction of diols and polyols into alkenes and dienes. Catalyst design involved variations on dioxomolybdenum(VI) supported by a dianionic meridional pincer ligand. Rational substrate scope was explored using aliphatic diols, aromatic diols, and biomass derived diols. Various reductants were tested for ability to catalyze the reaction. The substrate specific mechanism of DODH was explored utilizing NMR and in-situ infrared spectroscopy and important rate constants and rate determining steps were found to aid in the optimization of ideal reaction conditions. Catalytic activity was observed to …

Prescience, Bob De Smith

Pro Rege

No abstract provided.

Failure, Mary Dengler

Pro Rege

No abstract provided.

Day After Beating, Erica Hughes

Pro Rege

No abstract provided.