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Theoretical And Numerical Evidence For The Potential Realization Of The Peregrine Soliton In Repulsive Two-Component Bose-Einstein Condensates, A. Romero-Ros, Garyfallia C. Katsimiga, Simeon I. Mistakidis, B. Prinari, G. Biondini, P. Schmelcher, P. G. Kevrekidis

Physics Faculty Research & Creative Works

The Present Work Is Motivated By The Recent Experimental Realization Of The Townes Soliton In An Effective Two-Component Bose-Einstein Condensate By B. Bakkali-Hassan Et Al. [Phys. Rev. Lett. 127, 023603 (2021)PRLTAO0031-900710.1103/PhysRevLett.127.023603]. Here, We Use A Similar Multicomponent Platform To Exemplify Theoretically And Numerically, Within The Mean-Field Gross-Pitaevskii Framework, The Potential Toward The Experimental Realization Of A Different Fundamental Wave Structure, Namely The Peregrine Soliton. Leveraging The Effective Attractive Interaction Produced Within The Mixture's Minority Species In The Immiscible Regime, We Illustrate How Initialization Of The Condensate With A Suitable Power-Law Decaying Spatial Density Pattern Yields The Robust Emergence Of The …

Mechanical Properties Of Fusion Welded Ceramics In The Sic-Zrb2 And Sic-Zrb2-Zrc Systems, Jecee D. Jarman, William Fahrenholtz, Greg Hilmas, Jeremy Lee Watts, Derek S. King

Materials Science and Engineering Faculty Research & Creative Works

Mechanical properties of welded SiC-ZrB2 and SiC-ZrB2-ZrC ceramics were measured up to 1700 °C. Commercial powders were hot pressed, machined into coupons, and preheated to 1600 °C before joining the ceramics using either tungsten inert gas welding or plasma arc welding. Toughness of the parent materials was 3–4 MPa*m1/2 which decreased after welding to 2–2.5 MPa*m1/2. Strength of the SiC-ZrB2-ZrC parent material was ~700 MPa at 25 °C, ~300 MPa at 1700 °C, and retained 40–60% of this strength once welded. Strength of the SiC-ZrB2 parent material was ~600 MPa at 25 °C and 1700 °C and retained 20–30% of …

The Effect Of Tier 2 Intervention On Student Achievement & Student Self-Efficacy, Cheyenne Morgan Hill

Graduate Theses and Dissertations

Biology is a key course in a student's learning path. It provides important information about the living world and creates foundational knowledge that will be used in other science courses as the student progresses through his or her secondary and post-secondary education. However, there is a pattern of low student achievement in this required science course. The inability for students to understand and retain the curriculum in turn leads to low self-efficacy. Together, this creates a poor attitude toward science and a reluctance to pursue further science courses and in turn science careers. Response to Intervention (RTI), a common educational …

“All Skinfolk Ain’T Kinfolk”: Attributions Of Race-Based Discrimination When An Ingroup Member Is The Perpetrator, Christin Alexandra Mujica

Graduate Theses and Dissertations

Most research addressing racial/ethnic discrimination is focused on instances perpetrated by White people or someone not of the same race or ethnic background as the target (i.e., outgroup discrimination). However, based on theories of ethnic identity development and internalized racism, it is possible for people of color to discriminate against people in their own racial or ethnic group. The current study used a qualitative approach to 1) understand what people of color believe about racism and discrimination broadly and based on the race of the perpetrator, 2) describe under what situations (e.g., race of perpetrator or overtness/subtlety of the act) …

Photoassisted Nanoscale Memory Resistors, Amir Shariffar

Graduate Theses and Dissertations

Memristors or memory resistors are promising two-terminal devices, which have the potential to revolutionize current electronic memory technologies. Memristors have been extensively investigated and reported to be practical devices, although they still suffer from poor stability, low retention time, and laborious fabrication processes.

The primary aim of this project was to achieve a device structure of quantum dots or thin films to address a fundamental challenge of unstable resistive switching behavior in memristors. Moreover, we aimed to investigate the effects of light illumination in terms of intensity and wavelength on the performance of the fabricated memristor. The parameters such as …

The Effects Of Metronomic And Maximum-Tolerated Dose Chemotherapy In Colorectal Cancer Angiogenesis: A Combined Approach Using Endoscopic Diffuse Reflectance Spectroscopy And Mrna Expression, Ariel Isaac Mundo Ortiz

Graduate Theses and Dissertations

Colorectal cancer (CRC) continues to be one of the most incident and deadliest types of cancer worldwide. Chemotherapy has proven effective to reduce tumor burden for CRC patients, but there are several disadvantages associated with the use of mainstay maximtolerated dose (MTD) chemotherapeutic strategies. Metronomic chemotherapy (MET) has been developed as an alternative that addresses the shortcomings of maximum-tolerated dose chemotherapy but so far its effectiveness as a neoadjuvant strategy for CRC has not been explored.

This dissertation uses a combined optics and molecular biology approach (using diffuse reflectance spectroscopy and mRNA expression) to study the changes in angiogenesis and …

The Sel Implementation Monkey: Identifying Factors That Serve As Barriers To The Successful Implementation Of Sel In The Classroom And School Setting, Aron Dody

Graduate Theses and Dissertations

The purpose of this study was to identify factors that served as barriers to the successful implementation of social and emotional learning in the classroom and school setting. This study utilized a reflective case study approach concerning USD 417’s social and emotional learning implementation journey.

The research questions for this study were: 1. What factors or conditions serve as barriers to the implementation of SEL in the classroom and school setting? 2. What resources or supports would lead to increased fidelity amongst teachers in the implementation of SEL in the classroom and school setting?

The reflections and data were used …

Evaluation Of Benzobicyclon In Midsouth Rice (Oryza Sativa) Production Systems, Jake Patterson

Graduate Theses and Dissertations

Controlling weedy rice postemergence is challenging for rice producers in the United States because of the lack of herbicide options. Weedy rice is genetically similar to cultivated rice, thus making it difficult to control with mid-season postemergence herbicide applications without also damaging the crop. Hence, there is a need for a new effective postemergence weedy rice control herbicide. Findings from this research indicate that the use of benzobicyclon in current standard quizalofop- and imidazolinone-resistant rice herbicide programs provides tremendous utility for Midsouth rice producers. In both of these production systems, the addition of benzobicyclon to the respective standard herbicide programs …

Ab Initio Studies Of Structure And Properties Of Group-Iv Monochalcogenide Monolayers, Shiva Prasad Poudel

Graduate Theses and Dissertations

The goal of this dissertation is to study the structure of ferroelectric group-IV monochalcogenide monolayers (MMLs) and their material properties. This work also established a new buckled honeycomb phase of these monolayers. Chapter 1 serves as an introduction where the motivation for these studies is established. In chapter 2, I used eight different exchange-correlation functionals (XC) to study the structure of these 2D ferroelectrics and found that their properties are independent of the choice of XC functionals. These findings reveal that the ground-state ferroelectric unit cell can be described by only five independent parameters, whereas their paraelectric (square or rectangular) …

Posterior Predictive Model Checking Of The Hierarchical Rater Model, Nnamdi Chika Ezike

Graduate Theses and Dissertations

Fitting wrongly specified models to observed data may lead to invalid inferences about the model parameters of interest. The current study investigated the performance of the posterior predictive model checking (PPMC) approach in detecting model-data misfit of the hierarchical rater model (HRM). The HRM is a rater-mediated model that incorporates components of the polytomous item response theory (IRT) model, such as the partial credit model (PCM) and generalized partial credit model (GPCM), at the second level of the hierarchy, to model examinees’ responses to performance assessments. To date, the HRM has not been rigorously evaluated using PPMC techniques. Monte Carlo …

Evaluation Of Fenclorim Safener For Use In Rice With Group 15 Herbicides, Tristen Heath Avent

Graduate Theses and Dissertations

The development of herbicide resistance and the lack of effective herbicides to control problematic weeds has caused Arkansas rice (Oryza sativa L.) production to pursue alternative sites of action. Currently, very long-chain fatty acid elongase inhibitors are not labeled for U.S. rice production but have been widely used for Asian rice production systems. Previous research has demonstrated the utility of acetochlor and pyroxasulfone to provide in-season weed control for Arkansas rice production, but variable crop tolerance has been observed. Additionally, acetochlor at 1,260 g ai ha-1 elicited less rice injury when seeds were treated with a herbicide safener seed treatment …

A Geochemical And Mineralogical Evaluation Of The Mona Lisa Turquoise Mine, Polk County, Arkansas, Alexander Arai Goodsuhm

Graduate Theses and Dissertations

The presence of turquoise in Arkansas has long been disputed by geologists and gem collectors. Despite the prevalence of other phosphate minerals in Arkansas, such as planerite, wavellite, and variscite, the absence of an obvious copper (Cu) source required for turquoise formation was considered too great of an obstacle for turquoise mineralization. In this study, geologic, mineralogical, and geochemical techniques provide overwhelming evidence that the novaculite-hosted Mona Lisa Mine in Arkansas does produce turquoise. X-ray diffraction and Raman spectroscopy have confirmed the structural nature of the material and identified other phosphate minerals, such as crandallite, often found in assemblage with …

To The Window, To The Wall: Improving Environmental Monitoring Protocols, Sarah Jones

Graduate Theses and Dissertations

Detecting microorganisms on environmental surfaces via an environmental monitoring (EM) program is part of a preventive food safety culture. Environmental monitoring should 1) verify that food safety plans are reducing cross-contamination risk from surfaces to food, 2) pinpoint microbial niches, and 3) prevent the transmission of pathogens. Environmental monitoring programs utilize EM tools, such as sponges, to sample food contact and non-food contact surfaces. However, EM tool selection is determined by the individual food firm. This dissertation evaluated and characterized factors influencing EM program effectiveness in the food industry. Specifically, this dissertation focuses on the release of microorganisms from EM …

Factors Contributing To Barriers To Equity In Gifted And Talented Identification, Adam Grant Lamparske

Graduate Theses and Dissertations

The purpose of this study was to examine the existing barriers to equity in the identification and servicing of gifted students in a small mid-western suburban school district. A mixed method approach guided by constructivist philosophy was used to conduct this research. An inductive Grounded Theory was the methodological approach. This study sought to gather the perception of school district stakeholders to identify potential barriers that exist for specific subgroups of students to being identified for gifted and talented services. The research questions for this Problem of Practice were as follows: (1) How do teachers and parents in School District …

Finite Dimensional Approximation And Pin(2)-Equivariant Property For Rarita-Schwinger-Seiberg-Witten Equations, Minh Lam Nguyen

Graduate Theses and Dissertations

The Rarita-Schwinger operator Q was initially proposed in the 1941 paper by Rarita and Schwinger to study wave functions of particles of spin 3/2, and there is a vast amount of physics literature on its properties. Roughly speaking, 3/2−spinors are spinor-valued 1-forms that also happen to be in the kernel of the Clifford multiplication. Let X be a simply connected Riemannian spin 4−manifold. Associated to a fixed spin structure on X, we define a Seiberg-Witten-like system of non-linear PDEs using Q and the Hodge-Dirac operator d∗ + d+ after suitable gauge-fixing. The moduli space of solutions M contains (3/2-spinors, purely …

Examination Of The Colorful Semantic Approach Via Telepractice For Children Who Are Deaf Or Hard Of Hearing, Samadhi Pusuba Devayalage

Graduate Theses and Dissertations

Introduction: Hearing loss, deafness or hard of hearing are considered to be the inabilityof perceiving sounds beyond 20 dB. Due to a direct impact of a hearing loss, a developing brain undergoes difficulties in acquiring age-appropriate syntax and speech sounds. As a result, children with hearing loss present language, speech, and literacy disabilities. The current study discusses the efficacy of the colorful semantics approach in order to see its impact on sentence structure development. Methodology: A single subject withdrawal experimental study conducted following ABAB model. Two participants (6 years and 10 years) were recruited to the study following an inclusion …

Mobile Technology For Language Learning And Instruction: Investigating Beliefs And Attitudes Of Indonesian Efl Preservice Teachers, Dodi Siraj Muamar Zain

Graduate Theses and Dissertations

This study is primarily aimed to investigate beliefs and attitudes of Indonesian EFL preservice teachers toward the use of mobile devices such as smartphones or tablets for learning and instructional practice in Indonesia. Furthermore, this phenomenological study attempted to reveal the factors affecting these two constructs from 20 Indonesian EFL preservice teachers through semi-structured interviews. The findings revealed participants’ beliefs that mobile devices could positively contribute to the development of language performance as learning tools and the development of language instruction as instructional tools. Regarding attitudes of EFL preservice teachers toward the use of mobile devices for learning and teaching, …

Diederich-Fornæss Index On Boundaries Containing Crescents, Jason Demoulpied

Graduate Theses and Dissertations

The worm domain developed by Diederich and Fornæss is a classic example of a boundedpseudoconvex domains that fails to satisfy global regularity of the Bergman Projection, due to the set of weakly pseudoconvex points that form an annulus in its boundary. We instead examine a bounded pseudoconvex domain Ω ⊂ C2 whose set of weakly pseudoconvex points form a crescent in its boundary. In 2019, Harrington had shown that these types of domains satisfy global regularity of the Bergman Projection based on the existence of good vector fields. In this thesis we study the Regularized Diederich-Fornæss index of these domains, …

Exploring (Mis)Alignments Between First-Year Students’ Expectations And Experiences, Matthew G. Meyers

Graduate Theses and Dissertations

Understanding what expectations first-year students have for their first semester of college can help university faculty, staff, and administrators have a better understanding of how to best provide support and resources that meet the needs of their students and lay the necessary foundations for their academic and social success early on. Unfortunately, many students report a variety of social, academic, personal, and environmental experiences that do not fully match their expectations. The purpose of this study was to examine what expectations and experiences first-year college students had about their first semester and how they interpreted both alignments and misalignments between …

A Social Media Strategy Plan For The Jane B. Gearhart Full Circle Food Pantry, Sara Katelyn Holm

Graduate Theses and Dissertations

The Jane B. Gearhart (JBG) Full Circle Food Pantry is a student-led program that provides food assistance for members of the University of Arkansas community. This thesis project includes a social media strategy plan that aims to increase the overall awareness of the pantry and its multifaceted services to decrease food insecurity levels at the University of Arkansas. This plan intends to create behavioral changes that expand usage of the pantry and social media engagement among UA students. Grounded in data-driven insights, this plan is designed from (i) literature on food pantry marketing techniques; (ii) a review of the pantry's …

An Epidemic Of Skepticism: Examining Right-Wing Populist Responses To The Covid-19 Crisis In Germany, Rachel Moline

Graduate Theses and Dissertations

This thesis examines the role of far-right populist groups in the framing of global health crises. To understand the impact far-right populism has had on the response to health crises, I will be analyzing the case of the Alternativ für Deutschland (AfD), or Alternative for Germany, and their response to the ongoing coronavirus pandemic. I evaluate three distinct time periods in the AfD’s history and determine how the AfD has framed and reframed its crisis narrative in response to the coronavirus compared to previous crises, such as the refugee crisis of 2015. I hypothesize that new crises will lead far-right …

Evaluation, Characterization, And Utilization Of Weed-Suppressive Sweetpotato Cultivars For Sustainable Weed Management, Isabel Schlegel Werle

Graduate Theses and Dissertations

Sweetpotato (Ipomoea batatas L.) is a low-technology, subsistence crop that enhances food and nutrition security particularly in developing nations. Weed interference with the crop can reduce sweetpotato storage root yields and product quality. Current weed management practices in sweetpotato include PRE or POST herbicides application, cultivation, mowing, or handweeding. Unlike row crops, herbicide options for sweetpotato are few; therefore, alternative weed control practices are needed. The overall objective of this research was to determine the weed suppressive ability of several sweetpotato cultivars. This research also provides information about cover crop use for weed suppression in sweetpotato production in Arkansas. Field …

Crystal Growth And Property Tuning Of Layered Magnetic Topological Semimetals, Krishna Pandey

Graduate Theses and Dissertations

The demand for energy-efficient devices has been growing rapidly due to the need for data-driven technologies and the global energy crisis. As device size approaches the atomic scale, the miniaturization of electronic devices may stop in the near future unless fundamentally new materials or device concepts are developed. The emergent topological materials with exotic properties show remarkable robustness against crystal lattice defects, which are promising for next-generation technology. These materials host exotic properties such as high mobility, large magnetoresistance, chiral anomaly, and surface Fermi arcs, etc. Among various topological materials, the ZrSiS-family materials exhibit two types of Dirac states, which …

Introduction Of Human Acidic Fibroblast Growth Factor (Fgf1) Variant With Increased Stability And Bioactivity, Azadeh Tavousi Tabatabaei

Graduate Theses and Dissertations

Human acidic Fibroblast Growth Factor 1 (FGF-1) involves in a broad spectrum of biological processes, including cell growth, proliferation, differentiation, migration, angiogenesis, wound healing, and embryonic development. hFGF1 non-selectively binds to cell surface hFGF receptor isoforms to elicit these cell-signaling processes. Since hFGF1 plays a significant role in tissue repair activity, that is a prime candidate for novel wound healing therapeutics. However, hFGF1 has been found to unfold near physiological temperature due to a strong electrostatic repulsion created by a dense cluster of positively charged amino acids near the c-terminus. The problem not only leads to proteolytic degradation of the …

Arts Integration For Foreign Language Teaching And Learning: A Three Paper Dissertation, Qian Zhang

Graduate Theses and Dissertations

This three-paper dissertation examines whether arts integration-an approach to teaching in which students construct and demonstrate understanding through an art form-helps with foreign language teaching and learning, especially language performance. The first paper conducts a comprehensive literature review of research on arts integration and its use in the context of language classrooms, including both English as a Second Language and Foreign Language classrooms. The second paper is a qualitative case study exploring how a French teacher perceives the role that arts integration plays in her students’ language performance. Specific arts-integrated strategies are discussed, and connections are made to students’ language …

Robust And Fair Machine Learning Under Distribution Shift, Wei Du

Graduate Theses and Dissertations

Machine learning algorithms have been widely used in real world applications. The development of these techniques has brought huge benefits for many AI-related tasks, such as natural language processing, image classification, video analysis, and so forth. In traditional machine learning algorithms, we usually assume that the training data and test data are independently and identically distributed (iid), indicating that the model learned from the training data can be well applied to the test data with good prediction performance. However, this assumption is quite restrictive because the distribution shift can exist from the training data to the test data in many …

A Classical Delphi Study: Identifying The Essential Leadership Characteristics, Traits, And Skills Of Lutheran School Leaders, Alan Freeman

Graduate Theses and Dissertations

Principals play a key role in the success and sustainability of Lutheran Church Missouri Synod (LCMS) schools. This study examines the qualities, characteristics and traits possessed by successful Lutheran school leaders to provide a framework for developing current and future leaders of Lutheran schools. Today’s Lutheran school administrator must understand and be effective in financial planning, marketing, curriculum and instruction, community outreach and strategic planning in addition to the more traditional areas of curriculum and instruction, employee evaluation, and other school management tasks. Today’s successful Lutheran school administrator must be a leader and not just a manager. Thus, Lutheran schools …

Examining The Effects Of Oral Contraceptive Use On Thermoregulation, Whitley C. Atkins

Graduate Theses and Dissertations

Purpose: The purpose of this investigation was to evaluate the effects of combined (estradiol and progestin) monophasic oral contraceptive pill (OCP) use on thermoregulation. Further, we sought to evaluate OCP use on acute rehydration post-exercise in the heat using recommended rehydration guidelines. Methods: Twelve healthy, aerobically trained (VO2peak = 47.8 ± 4.7 mL/kg/min), long term female oral contraceptive users completed a familiarization trial and two experimental days separated by ≥ 7 days. The two experimental trials were identical except for the hormone dosing phase. One trial was completed during the third week of active pill dosing (ACT) and one during …

The Effects Of Alcohol Intoxication And Threats To Masculinity On Engagement In Sexual Aggression: Results From A Web-Based Survey Design And Alcohol Administration Study, Tiffany Lynn Marcantonio

Graduate Theses and Dissertations

Background: Research examining the combined effects of men’s alcohol consumption and perceptions of their masculinity as precarious (e.g., viewing masculinity as easily threatened) on sexual aggression (SA) is lacking. The goal of this dissertation study was to assess if alcohol consumption and precarious masculinity are related to men’s SA via a web-administered survey (Study 1) and an in-person alcohol administration experiment (Study 2).

Methodology: In Study 1, two samples of young adult men (aged 18-30) were collected, 1) a community sample of 492 men and 2) a college sample of 478 men, to complete a 20-minute survey; participants answered questions …

Arkansas Fresh-Market Blackberries: Identifying Unique Attributes And Harvest Practices That Impact Marketability, Andrea Lea Myers

Graduate Theses and Dissertations

Fresh-market blackberries (Rubus subgenus Rubus) are sold worldwide and have attributes that appeal to consumers. The delicate-nature of the fruit requires hand harvesting, and minimal handling of the fruit postharvest. Objectives of this research on Arkansas fresh-market blackberries was to 1) identify the unique attributes 2) determine the best handling practices to increase postharvest quality, and 3) evaluate the potential of soft robotic gripper for harvesting. For the first objective, blackberry genotypes were harvested from the University of Arkansas System (UA System) Division of Agriculture Fruit Research Station in Clarksville, AR. Nineteen genotypes were harvested in 2020, eight genotypes were …