Digital Commons Network^™

Fabrication Of Solar Absorber Tube With Internal Fin Structure With In718 And Effect Of Boron With In718 For Solar Absorber Tube Using Selective Laser Melting 3d Printing Technology, Naznin Nuria Afrin

Theses and Dissertations

This research aimed to fabricate Solar Absorber Tubes for Solar-Thermal Power Plant with internal fin structures using Selective Laser Melting (SLM) technology. In this study, we investigated the effect of B with IN718 in 3D printing using SLM for solar absorber tubes. The objective was to study the material-process-properties relationship with goal to identify and validate the optimal parameters for the SLM process. Material selected for this study was IN718 with 0.5% and 1% B particle mixed using a V-shape mixing machine. The flowability test was conducted using the Angle of Repose (AOR) method. 3D printed samples …

Wildlife Road Mortality Patterns In South Texas And Survey Methodology Improvement, Bradley E. Beer

Theses and Dissertations

Mortalities of wildlife caused by collisions with vehicles along roads are increasing in prevalence, threatening the existence of various species and populations. A better understanding of how mortalities change in response to natural and anthropogenic variables and efficient methods of obtaining mortality data are essential to mitigating such mortalities. This thesis investigates several key elements to improving road mortality surveys in south Texas. First, it was found that road mortality survey counts did not change under a pandemic-related lockdown and that 2 mortality survey observers detect more mortalities than 1. Analysis of brown pelican groundings on Texas State Highway 48 …

My Journey As An Elementary Science Teacher: From Linear To Authentic, Johanna Lynn Esparza

Theses and Dissertations

The purpose of this dissertation is to provide a personalized narrative of one science teacher’s use of reflexive teaching as an agent of change. This dissertation is about a journey of change in instruction fostered by a change of identity as a science teacher, using the butterfly cycle as a metaphor. This dissertation narrates the identity evolution of the teacher. This study has relevance because the process utilized by the teacher provides a method of self-examination and identity construction for other elementary science classroom teachers who want to improve their science practices. This study also has relevance because it describes …

High Throughput And Highly Controllable Methods For In Vitro Intracellular Delivery, Justin Brooks, Grayson Minnick, Prithvijit Mukherjee, Arian Jaberi, Lingqian Chang, Horacio D. Espinosa, Ruiguo Yang

Department of Mechanical and Materials Engineering: Faculty Publications

In vitro and ex vivo intracellular delivery methods hold the key for releasing the full potential of tissue engineering, drug development, and many other applications. In recent years, there has been significant progress in the design and implementation of intracellular delivery systems capable of delivery at the same scale as viral transfection and bulk electroporation but offering fewer adverse outcomes. This review strives to examine a variety of methods for in vitro and ex vivo intracellular delivery such as flow-through microfluidics, engineered substrates, and automated probe-based systems from the perspective of throughput and control. Special attention is paid to a …

Bevers: A General, Simple, And Performant Framework For Automatic Fact Verification, Mitchell Dehaven

School of Computing: Dissertations, Theses, and Student Research

Fact verification has become an important process, primarily done manually by humans, to verify the authenticity of claims and statements made online. Increasingly, social media companies have utilized human effort to debunk false claims on their platforms, opting to either tag the content as misleading or false, or removing it entirely to combat misinformation on their sites. In tandem, the field of automatic fact verification has become a subject of focus among the natural language processing (NLP) community, spawning new datasets and research. The most popular dataset is the Fact Extraction and VERification (FEVER) dataset. In this thesis an end-to-end …

Insights On Factors Influencing Startup Failure In The Hospitality Industry, Shivangi Khurania

UNLV Theses, Dissertations, Professional Papers, and Capstones

Hospitality businesses and innovative startups have faced extremely high failure rates. The author provides insights on the factors that impact startup failure in the hospitality industry after performing a deep analysis on innovation frameworks such as the diffusion of innovation theory, the theory of disruptive innovation, and the ten types of innovation framework. Not only that, the author also provides insights based on their own personal experience and knowledge gained through education at the University of Las Vegas, Nevada. The research explored in this paper revealed that startup failure is not based on one factor alone and how leaders in …

The Parkinson’S Prison And The Hero’S Journey To Escape: Improvisation And Storytelling In Parkinson’S Disease, Robert David Cochrane

UNLV Theses, Dissertations, Professional Papers, and Capstones

Parkinson’s disease (PD) is the fastest growing neurological disorder in the world, with leading researchers calling it a pandemic. While there is no cure, pharmaceuticals and surgical interventions increase people with Parkinson’s (PWP) ability to lead longer and more productive lives. However, there is a lack of care available for PWP supporting their social and emotional domains. PWP report high levels of stress, anxiety, and isolation due to the chronic and unpredictably progressive nature of the disease. This leads to a vicious cycle of loss of confidence, decreased activity and socialization, and increased falls.A common phrase in the PD community …

Payment Profiles: Using Payment Transaction Data To Identify And Characterize Gamblers, Kasra Ghaharian

UNLV Theses, Dissertations, Professional Papers, and Capstones

Payment providers in the gambling industry facilitate transactions, allowing customers to transfer money to and from wagering accounts. Payments transaction data is information that is captured from these transactions, including, for example, the type, amount, time, and location. How this data may be used for gambling harm minimization and prevention has garnered significant interest, particularly due to accelerated payments modernization in the wake of the COVID-19 pandemic. With this study, I explored the utility of payments transaction data to categorize subgroups of gamblers in order to identify individuals who may be at-risk of harm. I benchmarked six cluster analysis methods …

Hydrogeologic Heterogeneity Identification: Using Inverse Modeling Of Synthetic Borehole Temperatures To Predict Groundwater Flux, Kevin Heintz

UNLV Theses, Dissertations, Professional Papers, and Capstones

Heat has been effectively used as a groundwater tracer for decades, and high-resolution temperature data can better identify and quantify discrete flow zones. Refinements to the numerical modeling of advective heat transfer in borehole temperature sensing deployments can improve understanding of dynamic hydrogeologic systems. In my thesis, I develop a novel two-dimensional coupled radial groundwater flow and heat transfer numerical model that considers intra-borehole vertical flow. To test the performance of this model, I used finite element analysis to generate synthetic data sets consisting of prescribed variable flow fields and resulting borehole temperatures. I input synthetic temperatures into the two-dimensional …

Calcite Spherulite Formations And Their Controls In Halophilic Bacterial Cultures, Zakaria Jibrin

UNLV Theses, Dissertations, Professional Papers, and Capstones

This study arose from an accidental discovery of calcite spherulites forming on colonies of various halophilic bacteria grown on solid Luria-Bertani medium made containing water from a brine pool in Death Valley, their natural habitat. Further studies with a large spherulite forming bacteria, Pseudoalteromonas haloplanktis, showed that calcite precipitation conditions were the consequence of bacteria using amino acids as a source of carbon and energy, a metabolism that produces NH3 and CO2 waste products. NH3 raises the pH of the medium, turning CO2 into CO32-. Calcium in the natural brine combines with CO32-. The resulting spherulitic calcite precipitation is nano-acicular …

Negative Customer Reviews And The Online Decision-Making Process: The Role Of Construal Fit, Minji Kim

UNLV Theses, Dissertations, Professional Papers, and Capstones

Consumers seek out online reviews to aid their decision-making, particularly when purchasing products and services online. Given their power to influence consumer behavior, online reviews have been extensively studied in various settings. While much research has focused on what determines the performance of online reviews, limited research has focused on why a particular review receives more or less attention from consumers. This study aims to fill this knowledge gap by exploring how consumers with different mindsets respond to online reviews framed at different levels of construal. Applying the construal fit principle, this research predicts that consumers more fluently process online …

Study Of Narrative Effects Of Each Instrumental Group In Exemplum: In Memoriam Kwangju By Isang Yun, Jeahyun Jo

UNLV Theses, Dissertations, Professional Papers, and Capstones

Isang Yun (1917–1995) is recognized as one of the most notable avant-garde Korean composers of the twentieth century. His compositions serve as a crucial link between Eastern and Western musical traditions because they contain elements of techniques from both traditions. My intention in this paper is to examine Yun and his symphonic poem Exemplum: in Memoriam Kwangju with the goal of helping the reader comprehend its narrative effects. I will also provide a musical analysis and interpretation based on Yun’s intention in composing Exemplum: in Memoriam Kwangju and examine Yun’s compositional approaches to the three different instrumental groups (strings, wind, …

Factors Associated With Immediate Postnatal Care In Lao People's Democratic Republic: An Analysis Of The 2017 Lao People's Democratic Republic Multiple Indicator Cluster Survey, Tressa Quayle

UNLV Theses, Dissertations, Professional Papers, and Capstones

Purpose: This study aimed to identify potential factors associated with immediate postnatal care in Laotian women. Background: The World Health Organization recognizes that approximately half of all maternal deaths occur in the immediate postnatal period or 24 hours after birth. One crucial step to improving maternal mortality is a postnatal check during the first 24 hours following birth. Forty-seven percent of Lao women aged 15-49 who delivered a baby in the last two years received a postnatal health check in the first two days after delivery. Of these, 46.5% of postnatal checks were conducted prior to discharge from the facility …

Examination Of The Relationship Between Loneliness And Binge Eating Symptoms, Kimberly Stevens

UNLV Theses, Dissertations, Professional Papers, and Capstones

Loneliness is implicated in several mental health conditions and may also be linked to eating pathology, like binge eating symptoms (e.g., loss-of-control eating). However, the pathways by which loneliness might be associated with binge eating symptoms are less well understood. Preliminary evidence suggests perceived stress may be a key explanatory pathway. Specifically, perceived stress mediates the impact of loneliness on other mental health outcomes and is associated with increased risk of binge eating symptoms. This study investigated relationships between loneliness, perceived stress, and binge eating symptoms and tested whether heightened levels of binge eating was accounted for by increases in …

Predicting Student Success In A K-12 Online School, Andrea Connolly

UNLV Theses, Dissertations, Professional Papers, and Capstones

Given the rapid growth of K-12 online learning, research is needed in the effective identification of at-risk students so that administrators and teachers can develop appropriate supports and interventions. The purpose of this research was to determine if student success in an online course could be predicted for English Learners (EL) using identifiable student characteristics and traits. This study looked at the student traits of behavior, structure, and demographics to determine if they could be used as predictive variables for successful course completion in a K-12 online course. The behavior characteristics were measured by a survey tool and were identified …

A Glass Bead Semi-Hydroponic System For Intact Maize Root Exudate Analysis And Phenotyping, Martha G. Lopez-Guerrero, Peng Wang, Felicia Phares, Daniel P. Schachtman, Sophie Alvarez, Karin V. Van Dijk

Department of Agronomy and Horticulture: Faculty Publications

Background: Although there have been numerous studies describing plant growth systems for root exudate collection, a common limitation is that these systems require disruption of the plant root system to facilitate exudate collection. Here, we present a newly designed semi-hydroponic system that uses glass beads as solid support to simulate soil impedance, which combined with drip irrigation, facilitates growth of healthy maize plants, collection and analysis of root exudates, and phenotyping of the roots with minimal growth disturbance or root damage. Results: This system was used to collect root exudates from seven maize genotypes using water or 1 mM CaCl2, …

Differences In Elementary Students’ Self-Regulated Processes For Computer Versus Printed Reading Assignments, Katerina Sergi, Anastasia Elder, Tianlan Wei, Kristin Javorsky, Jianzhong Xu

Publications

The purpose of this study was to investigate metacognitive self-regulated learning (SRL) differences in computer- and paper-based reading assignments across elementary students. Students in two after-school programs in a southeastern U.S. public school district were recruited. The final sample consisted of 48 students in Grades 2–5 who participated in two counterbalanced conditions involving a computer- and a paper-based reading assignment. The study employed a 2 x 4 (condition-by-grade) mixed-model analysis of variance (ANOVA) and followup tests to examine metacognitive SRL differences between conditions and grades. The results indicate that elementary students used various metacognitive SRL skills across both conditions. The …

Optimizing Disaster Preparedness Planning For Minority Older Adults: One Size Does Not Fit All, Omolola E. Adepoju, Luz E. Herrera, Minji Chae, Daikwon Han

Faculty Scholarship

By 2050, one in five Americans will be 65 years and older. The growing proportion of older adults in the U.S. population has implications for many aspects of health including disaster preparedness. This study assessed correlates of disaster preparedness among community-dwelling minority older adults and explored unique differences for African American and Hispanic older adults. An electronic survey was disseminated to older minority adults 55+, between November 2020 and January 2021 (n = 522). An empirical framework was used to contextualize 12 disaster-related activities into survival and planning actions. Multivariate logistic regression models were stratified by race/ethnicity to examine the …

Anion Alloying Of Iii-V Semiconductors For Water Splitting., Sonia Calero-Barney

Electronic Theses and Dissertations

The challenge of solar energy conversion and storage translates into the discovery and development of semiconductor materials that can transform sunlight energy into electricity and/or high-energy-density fuels in a cost-effective way. From the solar energy conversion perspective, cation-alloyed III-V solar cells hold record-breaking energy conversion efficiencies, while anion-alloyed III-V’s are particularly interesting for photoelectrochemical hydrogen generation. The major challenge for the adoption of III-V-based technologies lies in the high manufacturing costs of established synthesis techniques and the difficulty to control the composition of ternary alloys. One of the materials investigated in this work is GaSb_zP_1-z. Thermodynamic …

The Impact Of Volatile Organic Compound Exposure On Subclinical Biomarkers Of Cardiovascular Injury., Breandon Taylor

Electronic Theses and Dissertations

Pollution has been identified as the leading environmental cause of non-communicable disease and premature deaths globally. Volatile organic compounds (VOCs) are gaseous chemical constituents of pollution derived from a variety of sources, including industrial solvents and byproducts, automobile exhaust, tobacco smoke, cleaning supplies, and personal care products. VOCs are also abundant at various Superfund and Hazardous Waste Sites. Emerging data suggest that VOC exposure is associated with several adverse health outcomes, including cardiovascular disease (CVD). VOCs and their metabolites can potentially damage the endothelial lining of blood vessels, resulting in perturbed vascular function and vascular inflammation. We hypothesize that VOC …

Foreign Policy In Media: An Examination Of The Captain America Films., Kat Hernandez

Electronic Theses and Dissertations

Popular culture and media are consumed daily by billions around the world, media which can contain meaningful and politically relevant material. The three Captain America films from the 2010s represent this phenomenon in the presentation of Captain America as a nationalist superhero with geopolitically relevant storylines. The direction and production of these films illustrate significant parallels to foreign policy choices of the United States. Through an interpretive analysis of the Captain America films: Captain America: The First Avenger, Captain America: The Winter Soldier, and Captain America: Civil War, this project seeks to analyze Captain America’s image and …

The Impact Of Pegylation On Cellular Uptake And In Vivo Biodistribution Of Gold Nanoparticle Mri Contrast Agents., Nagwa El-Baz

Electronic Theses and Dissertations

Gold nanoparticles (GNPs) have become a pivotal platform for the delivery of pharmaceutical and diagnostic agents as well as for general therapeutic purposes. Despite their potential for use in biomedicine, their interaction with serum proteins is crucial as it could change their biological profile due to the formation of a protein corona, which can affect their delivery to target tissues in the body. Grafting the GNPs with polyethylene glycol (PEG) is widely used in research to decrease opsonization of the particles by serum proteins and decrease the uptake by the reticuloendothelial system. Here in this dissertation, we have developed a …

A Mixed Methods Assessment Of Menstrual Hygiene Management And School Attendance Among Schoolgirls In Edo State, Nigeria., Madeline Tomlinson

Electronic Theses and Dissertations

Menstrual hygiene in lower-middle-income countries (LMICs) is limited and has been linked to many health, educational and social effects. However, the prevalence, details, and impact of menstrual hygiene management have not been well characterized in rural and peri-urban settings across Nigeria. The overall purpose of this research was to investigate menstrual hygiene management (MHM) among adolescent schoolgirls in peri-urban areas of Edo State, Nigeria; and to determine the educational consequences associated with poor MHM. MHM was measured using previously validated questions that were adapted after a formative assessment of MHM within the Edo State community. We used a mixed methods …

A Psychometric Analysis Of The Comprehensive School Survey (Css) Middle School Student Version., Stephen Leach

Electronic Theses and Dissertations

School climate is increasingly recognized by scholars and policymakers as a crucial factor associated with students’ educational experiences. Hence, practitioners endeavor to equitably measure and improve school climate to promote favorable student academic and behavior outcomes. Unfortunately, school climate research is fragmented, and a research-practice gap exists in best scale development and validity testing practices. The result is a proliferation of practitioner-developed school climate measures lacking solid theory-grounding and evidence to support intended score interpretations and uses. In response, Whitehouse et al. (2021) proposed a validity testing framework for practitioner-developed instruments aimed at supporting culturally responsive school climate measurement. Their …

Stigma Described By Attempt Survivors With Diverse Gender And Sexual Identities In Their Suicide Stories: A Hermeneutic Phenomenological Dissertation., Sara Williams

Electronic Theses and Dissertations

Suicide is a profoundly impactful issue across societies. Gender and sexually diverse (GSD) populations exhibit rates of suicidal ideation and behavior far greater than those of cisgender heterosexual populations. Stigma impacts health outcomes among GSD populations through stress exposure and response processes. Compound stigma is experienced when individuals occupy positions in multiple stigmatized identity groups and can have multiplicative effects on adverse outcomes. Further, opportunities for positive social support and resilience building may be limited due to the narrow convergence of stigmatized identity groups. Stigma among GSD suicide attempt survivors (GSDAS) is an important phenomenon to explore in order to …

Leadership Competencies For Instructional Designers: Identifying Critical Incidents Used To Lead Design Projects That Improve Performance, Heidi Elaine Kirby

STEMPS Theses & Dissertations

Even though an instructional designer may not have formal authority or direct reports, to be successful, they need leadership skills. Although the literature calls for instructional designers to possess several critical leadership skills, it does not consistently present the same important skills and often defines them very broadly. Further, authors who have argued that leadership skills are not taught to instructional designers in a sufficient way often call for more education on leadership competencies in graduate school, but the literature does not state where these skills are currently being learned and fostered.

This qualitative research study used methods of grounded …

A Relevance Model For Threat-Centric Ranking Of Cybersecurity Vulnerabilities, Corren G. Mccoy

Computer Science Theses & Dissertations

The relentless and often haphazard process of tracking and remediating vulnerabilities is a top concern for cybersecurity professionals. The key challenge they face is trying to identify a remediation scheme specific to in-house, organizational objectives. Without a strategy, the result is a patchwork of fixes applied to a tide of vulnerabilities, any one of which could be the single point of failure in an otherwise formidable defense. This means one of the biggest challenges in vulnerability management relates to prioritization. Given that so few vulnerabilities are a focus of real-world attacks, a practical remediation strategy is to identify vulnerabilities likely …

A Nexus Of Literate Activity: The Design Of Writing Assignments In The Disciplines, Lauriellen Stankavich

English Theses & Dissertations

Writing plays a critical role in higher education as students are inducted into disciplinary practices through different genres, methodological repertoires and argumentation strategies. In Writing Across the Curriculum (WAC) initiatives, the instructor serves as an embodied reservoir of disciplinary knowledge and an arbiter of literate practices but most crucially employs the mediating capacities of the writing assignment as a potent pedagogical nexus. In this practice space, the instructor acts as designer of the pedagogical experience—the course as a whole and writing assignments in particular. This study used interviews, survey, and the collection of syllabi and other instructional artifacts to examine …

Tiny Tusks Breastfeeding And Infant Support: Breastfeeding's Effects On Maternal Mental Health, Anna Jacobs

The Eleanor Mann School of Nursing Undergraduate Honors Theses

Breastfeeding has proven to be beneficial for infant health and maternal physical health, but there are variable outcomes for maternal mental health. This literature review explores the relationship between breastfeeding and maternal mental health, a topic that is often disregarded when discussing breastfeeding with mothers. After an internship with Tiny Tusks Breastfeeding and Infant Support, a program to make breastfeeding more accessible at Razorback Athletics events, maternal mental health related to breastfeeding was shown to be a topic in need of more current research. This objective of this literature review was to determine how breastfeeding can impact maternal mental health …

“This Isn't Working For Me. Can We Do It A Different Way?" The Lived Experiences Of Geoscience Students With Learning Disabilities, Nina Morris

Masters Theses

The purpose of this exploratory qualitative study is to better understand the lived experiences of geoscience students with learning disabilities in their geoscience classes. Students with learning disabilities bring a unique perspective while also facing unique challenges in post-secondary education. In the literature, there is limited information on what support and teaching strategies are beneficial to this population. Undergraduate and graduate geoscience students who identify as having a learning disability from colleges and universities in the United States were recruited. Six students consented to participate in the study, and each completed a semi-structured interview. Semi-structured interviews were designed to prompt …