Digital Commons Network^™

Design And Optimization Of A Novel Monolithic Spring For High-Frequency Press-Pack Sic Fet Modules, Bogac Canbaz

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

Silicon Carbide (SiC) Field-Effect Transistor (FET) modules lead the way in power electronics, being superior in efficiency and robustness for high-frequency applications. The shift towards SiC from traditional silicon (Si)-based devices is driven by its superior thermal conductivity, higher electric field strength, and operational efficiency at elevated temperatures. These features are critical for the development of next-generation, grid-oriented power converters aimed at enhancing the reliability and sustainability of power systems. This research focuses on high-frequency press-pack (HFPP) SiC FET modules, addressing the primary challenge of miniaturizing SiC FET dies without compromising performance, through an innovative press-contact design essential for increased …

Charge And Strain Engineering Of Ferroic And Correlated Oxides, Yifei Hao

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

This dissertation presents a comprehensive study of the charge and strain effects on the electronic and magnetic properties of epitaxial ferroic and correlated oxide thin films and heterostructures. We perform the planar Hall effect to quantify the magnetocrystalline anisotropy (MCA) in epitaxial La_1-xSr_xMnO₃ films (x = 0.2 and 0.33) deposited on SrTiO₃ substrates. The biaxial magnetic anisotropy energy of L_0.67Sr_0.33MnO₃ is about 17% larger than La_0.8Sr_0.2MnO₃. By comparing with the theoretically predicted values, we have decoupled the doping and strain effects on …

Sun, Thunder, Daugava: Accessible Choral Music From The Latvian Choral Tradition, Paul M. Von Kampen

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

I have been fortunate enough to visit Latvia twice, once in 2009 and again in 2023. With connections made through the global outreach arm of the Lutheran Church Missouri–Synod, I was able to incorporate myself into Latvian culture in ways that may not have been possible had I been a standard tourist. I am grateful to have been invited into the homes of Latvian friends, to have studied in the Jāzeps Vītols Music Academy Library, and to have celebrated both the Jāņi midsummer festival in the Latvian countryside and my twenty-second birthday on the shores of the mighty Daugava River. …

Next-Generation Crop Monitoring Technologies: Case Studies About Edge Image Processing For Crop Monitoring And Soil Water Property Modeling Via Above-Ground Sensors, Nipuna Chamara

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Artificial Intelligence (AI) has advanced rapidly in the past two decades. Internet of Things (IoT) technology has advanced rapidly during the last decade. Merging these two technologies has immense potential in several industries, including agriculture.

We have identified several research gaps in utilizing IoT technology in agriculture. One problem was the digital divide between rural, unconnected, or limited connected areas and urban areas for utilizing images for decision-making, which has advanced with the growth of AI. Another area for improvement was the farmers' demotivation to use in-situ soil moisture sensors for irrigation decision-making due to inherited installation difficulties. As Nebraska …

Singing While Acting: A Mixed Methods Study Of Classical Singers’ Application Of The Chekhov And Meisner Acting Methods, Amy C. Johnson

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

When considering the minimal acting training incorporated into most voice performance programs, it is understandable why many singers struggle to balance vocal demands with acting demands. Furthermore, the expectations on singers to deliver authentic and nuanced performances are increasing as opera evolves. There is little in-depth understanding of classical singers’ experiences with applying specific acting techniques to their singing. There is also little information about how different acting methods may affect classical singing. This mixed methods collective case study aims to identify the impact of training in a specific acting method on classical singing. The qualitative strand focuses on the …

Exploring Affective Experiences Of Queer Individuals Navigating Relationships With Evangelical Parents, Grace Pappas

School of Social Work Faculty Publications and Presentations

An abundance of scholarship explores and discusses the process of queer identity development, including the experience of disclosing one’s queer identity, often referred to as coming out. Coming out to one’s parent(s) can be a challenging and complex experience for queer individuals, particularly for children from religious families. In this study, I explored the nuanced relationships between queer individuals and their Evangelical parents. I conducted qualitative interviews with nine participants. Using thematic analysis and Ahmed’s theory of affect and happy objects, I constructed four themes: (a) learning the affect queer carries, (b) feeling the affects of being queer, (c) how …

Impact Of Pollution On Marginalized Communities: Case Study Of Omaha, Nebraska, Miqaela Davis

Department of Environmental Studies: Undergraduate Student Theses

Environmental justice has been a struggle within our country for years. The goal of Environmental justice is for the fair treatment and equal voice for every single individual regardless of race, income, gender, etc. There has been environmental injustice and racism in many cities, but this study focuses on Omaha, Nebraska. Key questions include: What are some specific pollutants that are prevalent in areas with differing racial majorities in Omaha? What are some of the health patterns in these areas and does it relate to environmental racism? How has Omaha reinforced environmental racism through city planning? Using the Climate and …

Development Of A Multi-Use Modular Microfluidic Platform Using 3d Printing, Carson Emeigh

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Microfluidic lab-on-a-chip (LoC) technology has driven numerous innovations due to their ability to perform laboratory-scale experiments on a single chip using microchannels. Although LoC technology has been innovative, it still suffers from limitations related to its fabrication and design flexibility. Typical LoC fabrication, with photolithography, is time consuming, expensive, and inflexible. To overcome the limitations of LoC devices, modular microfluidic platforms have been developed where multiple microfluidic modules, each with a specific function or group of functions, can be combined on a single platform. Modular microfluidics have overcome some of the limitations of LoC devices, but currently, their fabrication is …

Peritextual Elements In Chinese Nonfiction Picturebooks, Sunah Chung, Jongsun Wee, Sohyun Meacham

Faculty Publications

The present work is a comparison of the peritext typology found across various nonfiction picturebooks focusing on Chinese people, including Chinese Americans. Nineteen nonfiction books were chosen following selection methods described in previous literature. Books were individually analysed to see which of five categories they fit under, and insider/outsider status for each author and illustrator was recorded as well. All five types were found in the surveyed Chinese nonfiction picturebooks; however, none of the books encouraged readers to take action for social change. We also found slight variation in peritext usage between the insiders and outsiders for authors and illustrators. …

Age, Gender, And Sexual Orientation And Their Effects On Online Dating Motivations, Jenna Leigh Mcpherson

UNLV Theses, Dissertations, Professional Papers, and Capstones

Online dating and dating apps are becoming more common as a means to meet a romantic or sexual partner (e.g. Rosenfeld, Thomas, & Hausen, 2019). Previous literature on the motivations for why people use dating apps and how they differ among participants of varying age, gender, and sexual orientation has not allowed for comparisons across these groups, or shows conflicting findings. In order to consolidate existing literature and further explore the topic, I conducted both a meta-analysis and meta-synthesis. The meta-analysis demonstrated a gender difference in the motivation of casual sex, such that men scored higher than women. The meta-synthesis …

Examining The Risks And Resilience Of Older Adults Living With Hiv/Aids: Qualitative Community-Based Participatory Research Studies In Southern Nevada, Brandon Ranuschio

UNLV Theses, Dissertations, Professional Papers, and Capstones

Since the height of the HIV pandemic in the 1980s, medical interventions have significantly increased the life expectancy of people living with HIV/AIDS (PLWH) and made HIV/AIDS a livable, chronic health condition. Because of this, PLWH have been living longer lives and thriving with the help of HIV sector healthcare and service providers. However, with their longer life expectancy, older PLWH have been experiencing other health challenges. One such challenge is the risk of developing HIV-Associated Neurocognitive Disorder (HAND), which is a condition that affects up to 50% of PLWH at some point in their lifetime, with middle-aged and older …

Enhancing The Relationships Between Students With Emotional And Behavioral Disorders And Their Teachers, Jack Watts

UNLV Theses, Dissertations, Professional Papers, and Capstones

Outcomes of students with emotional and behavioral disorders (EBD) have failed to meet the standards of educators and educational researchers. For several decades, such students have had worse academic and postsecondary outcomes than any other student population. This has led to emphasis on implementation of evidence-based practices to combat the negative outcomes associated with educational diagnoses of EBD (i.e., behavioral outbursts, suspension, and expulsion). Despite this increased attention, little improvement has occurred, leading to the question of whether practices implemented for students with EBD have been addressing the underlying causes of these students’ negative outcomes. Student–teacher relationships could be an …

Black Women Educational Leaders In Pk-12 Public Education: A Multiple Case Study On The Double Consciousness Of Black Women Educational Leadership In Southwestern United States, Malena Baizan

UNLV Theses, Dissertations, Professional Papers, and Capstones

This dissertation examined the stories of Black Women Educational Leaders (BWEL) in PK-12t public education and their double consciousness as expressed through their leadership. The focus of this study was BWEL’s counternarratives as leaders within a system built upon systemic racism and oppression. Their experiences as Black Women Educational Leaders in PK-12 in a school district in which most school administrators are white, but most of the student body is Black and Brown were highlighted and centered to shed light on how the double consciousness of Black women informs their leadership. Utilizing Critical Race Feminism as the theoretical framework with …

Differential Expression Of Microrna Mir-145 And Mir-155 Downstream Targets In Oral Cancers Exhibiting Limited Chemotherapy Resistance, Conner Belnap

UNLV Theses, Dissertations, Professional Papers, and Capstones

Background: New evidence has suggested that non-coding microRNAs play a significant role in mediating and modulating chemotherapy resistance, particularly among oral cancers. One recent study found that the expression of miR-145 and lack of miR-155 expression strongly correlated with a limited chemotherapy resistance to Cisplatin, 5-Fluorouracil and Paclitaxel , although the mechanism(s) responsible for these observations remain unidentified.

Methods: Using commercially available cell lines of oral squamous cell carcinoma (OSCC), RNA was isolated using phenol:chloroform extraction. The isolated RNA was converted into cDNA by reverse transcription and subsequently screened for the presence or absence of downstream targets of miR-145 and …

Exploring Intention Mapping And Action In Pursuit Of Emotional Storytelling For Musicians, Douglas Carpenter

UNLV Theses, Dissertations, Professional Papers, and Capstones

This document presents a novel approach to music education by integrating acting pedagogies, specifically the concepts of "Intention" and "Action," to enhance the expressive capabilities of musicians. Rooted in the methodologies of Konstantin Stanislavski, Sanford Meisner, and Michael Chekhov, this research seeks to bridge the gap between traditional music education, which often emphasizes technical execution, and the need for emotional expressivity and storytelling in musical performances.

The role of the musician as a 'human instrument,' capable of conveying complex human emotions and narratives through music is explored in this document. Drawing from acting techniques, the document proposes methods to help …

Causal Attribution Tendencies Of Early Childhood Practitioners And The Efficacy Of Attribution Retraining, Alex J. Faucheux

UNLV Theses, Dissertations, Professional Papers, and Capstones

Early childhood practitioners frequently attempt to identify the cause of outcomes experienced by their learners. This is sometimes referred to as causal attribution. Causal attribution may be affected by prior success and failure of a learner, the amount of effort exerted by the learner, the ability level of the learner, and knowledge of any disability associated with the learner, all of which can be considered controllable or uncontrollable, stable or unstable, and internal or external (Weiner, 1986; Woodcock & Vialle, 2011). As practitioners attribute cause to outcomes, they start to develop attributional tendencies; these tendencies, along with the cues and …

Roadblocks To Momentum: An Analysis Of College Major Gpa Restrictions And Stranded Students, Michael J. Hack

UNLV Theses, Dissertations, Professional Papers, and Capstones

College retention, persistence, and completion are key indicators of a successful institution, but six-year degree completion has remained stagnant in recent years (National Student Clearinghouse Research Center, 2022). Despite institutional efforts through success initiatives to keep students retained, one set of barriers to degree completion may be due to established major GPA restrictions and policies that prevent students from being able to declare their majors. Accordingly, students who are unable to declare their major but keep enrolling in courses may be in danger of becoming “stranded.” This quantitative examination of student data from one large public four-year college aims to …

Surface Coating Method For Cement-Based Materials To Improve Chloride Ion Penetration Resistance Using Amine-Based Co2 Solvent, Seongho Han, Tae Hoon Han, Jae Hong Kim

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The application of coatings on concrete surfaces serves as a protective shield, guarding the structure against chlorides and averting corrosion of the reinforcement, consequently enhancing its durability. This study investigates the resistance of cement mortar samples to chloride ion penetration when coated with an amine-based carbon dioxide (CO2) solvent. Various factors, including monoethanolamine (MEA) concentrations of 1, 10, and 30 wt.%; water-to-cement ratios (w/cm) of 0.35, 0.4, and 0.5; coating timings on day 3 and day 27; and pre-conditioning methods such as air drying, are investigated for their impact on the performance of chloride penetration resistance. Specifically, pre-conditioning significantly enhanced …

Modeling Inflation Transmission Among Different Construction Materials, Mohamad Abdul Nabi, Islam H. El-Adaway, Rayan H. Assaad

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Cost estimating in the construction industry is challenging due to the high uncertainty associated with the supply chain, especially after the COVID-19 pandemic. Some research studies have addressed such problems by developing models that predict material cost. In fact, all material can be interconnected and interrelated with lead-lag relationships such that any inflation in one material's price can be associated with inflation in other materials' prices, referred to as transmission of inflation. Despite the latter, none of the existing studies have investigated inflation transmission among all construction materials. This paper fills this knowledge gap. The authors used a multistep research …

A Review Of Whipple Shield Ballistic Limit Equations, S. Ryan, W. (William) P. Schonberg

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Ballistic limit equations (BLEs) are semi-analytical expressions used to predict the risk posed by micrometeoroid and orbital debris (MMOD) impacts on a spacecraft. A foundational BLE, known as the new non-optimum (NNO) equation was published by Eric Christiansen of NASA Johnson Space Center in 1990 for application on Whipple shields – two-plate configurations consisting of a thin sacrificial plate located at some standoff in front of the spacecraft pressure hull or structural wall. Today, BLEs for almost all multi-plate spacecraft structures, e.g., honeycomb sandwich panels, monolithic structures with thermal insulation blankets, etc., are based on the NNO Whipple BLE. We …

Investigating Causes Of Disputes Resulting In Litigation In Airport Development Projects In The United States Using Graph-Based Techniques, Ramy Khalef, Islam H. El-Adaway

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Airports represent a crucial a sector of the US infrastructure, but they were documented to have scored a D+. To mitigate this, governmental authorities have issued initiatives to update the airport infrastructure. With an expected critical junction for a major transformation in the airport sector, it is anticipated that airport projects will increase. This shall result in an escalation in the number of disputes. Previous research analyzed dispute concerns within the construction sector, but none tackled the perspective of airport projects. Accordingly, the goal of this study is to investigate the leading causes of disputes in litigation within US airport …

The Influence Of Personal Factors On Wrongful Convictions, Ellee Jackson

Masters Theses and Doctoral Dissertations

Previous work has identified factors that influence the likelihood of wrongful conviction. However, fewer efforts have been made to examine how these factors influence the amount of time between wrongful conviction and exoneration. This is crucial to the expansion of innocence research and the contextualization of wrongful convictions within the criminal justice system. This study employs negative binomial regression to analyze data collected by the National Registry of Exonerations (NRE). Using a sample of 2,349 cases in which the most severe conviction was murder, sexual assault, child sexual abuse, or drug possession, I examine the influence of an exoneree’s age, …

Effect Of Pre-Heating On Residual Stresses And Deformation In Laser-Based Directed Energy Deposition Repair: A Comparative Analysis, Usman Tariq, Sung Heng Wu, Muhammad Arif Mahmood, Michael M. Woodworth, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Laser-Directed Energy Deposition (DED), a Metal Additive Manufacturing Method, is Renowned for its Role in Repairing Parts, Particularly When Replacement Costs Are Prohibitive. Ensuring that Repaired Parts Avoid Residual Stresses and Deformation is Crucial for Maintaining Functional Integrity. This Study Conducts Experimental and Numerical Analyses on Trapezoidal Shape Repairs, Validating Both the Thermal and Mechanical Models with Experimental Results. Additionally, the Study Presents a Methodology for Creating a Toolpath Applicable to Both the DED Process and Abaqus CAE Software. the Findings Indicate that Employing a Pre-Heating Strategy Can Reduce Residual Stresses by over 70% Compared to No Pre-Heating. However, Pre-Heating …

Persistent Identifiers And The Next Generation Of Legal Scholarship, Aaron Retteen, Malikah Hall-Retteen

Faculty Scholarship

This article discusses the importance of the most common persistent identifiers in scholarly communications—the digital object identifier and the ORCID identifier—to legal scholarship. Persistent identifiers help preserve and disseminate academic content and data-driven services that leverage this information standard are now integrated into the publication process. Because legal publishers have not widely adopted persistent identifiers, the legal discipline cannot enjoy the benefits offered by this system. This article looks at barriers to implementing persistent identifiers among legal publishers and provides an anecdotal example of creating a sustainable workflow between the law library and student-run law journals.

Presence Of Nematodes In Gopherus Polyphemus In The Abacoa Greenway, Leighton Stack

Harriet L Wilkes Honors College Theses 2020 - Present

Endo-parasitic nematodes infect the gastrointestinal tract of their reptile hosts including the Gopher polyphemus species. Gopher tortoises are a keystone species that are recognized as a threatened species in Florida. The health of the gopher tortoises is negatively affected by these parasites that cause a plethora of diseases and symptoms. Convenience sampling was used to collect fecal samples from tortoises of the Abacoa Greenway over the past two years. PCR amplified isolated DNA from the fecal samples for a consensus sequence of the nematode 18S rRNA gene. Visualization of the PCR reactions via gel electrophoresis revealed amplification of the appropriately …

"Into The Womb Of Solipsism": The Spectrum Of Loneliness In Wallace's Infinite Jest, Michael Gieger

Theses, Dissertations and Culminating Projects

Academic critics and casual readers of David Foster Wallace’s 1,079-page novel, Infinite Jest, have long ruminated over the book’s daunting physical size and wide narrative scope. This paper offers an argumentative interpretation of the novel’s immensity through an exploration of Wallace’s thematic preoccupation with solipsism and human loneliness. Building primarily from the critical works of Frank Cioffi and Casey Michael Henry, this essay makes the contention that the length of Infinite Jest behaves mimetically, simulating for its attentive readership a sense of perpetual emotional isolation—an isolation reflective of the epic’s untold lonesome characters. The argument further suggests that length of …

Explaining Misinformation Detection Using Large Language Models, Vishnu S. Pendyala, Christopher E. Hall

Faculty Research, Scholarly, and Creative Activity

Large language models (LLMs) are a compressed repository of a vast corpus of valuable information on which they are trained. Therefore, this work hypothesizes that LLMs such as Llama, Orca, Falcon, and Mistral can be used for misinformation detection by making them cross-check new information with the repository on which they are trained. Accordingly, this paper describes the findings from the investigation of the abilities of LLMs in detecting misinformation on multiple datasets. The results are interpreted using explainable AI techniques such as Local Interpretable Model-Agnostic Explanations (LIME), SHapley Additive exPlanations (SHAP), and Integrated Gradients. The LLMs themselves are also …

Development And Evaluation Of A Modeling Platform For Evaluating Immunotherapeutic Efficacy In The Tumor Microenvironment., Dylan Andrew Goodin

Electronic Theses and Dissertations

The tumor microenvironment (TME) represents the complex outcome of numerous tumor, stromal, and immune interactions, and whose composition can significantly affect treatment response. Particularly, immunotherapeutic efficacy is subject to multiple tumor-specific TME interactions that may be difficult to evaluate/predict clinically. Mathematical modelling has been formulated to evaluate specific aspects of the TME, including vasculature, ECM deposition, and immune-tumor interactions. However, the computational challenge of simulating multiple TME interactions has led to sacrificing varying degrees of model generalizability and clinical relevance. This work describes increased computational performance of a 3D continuum model that simulates tumor tissue, ECM, and vasculature using a …

Still I Rise: A Critical Utopian Action Research Study On Black Femme-Identifying And Gender Expansive Emerging Adults In Technology Leadership., Alisia Mcclain

Electronic Theses and Dissertations

This Critical Utopian Action Research (CUAR) study delves into the intersection of authentic leadership, Black Feminist Thought (BFT), and technology leadership development, focusing on the perspectives of emerging adult Black femme-identifying or gender-expansive individuals. Addressing two primary research questions, the study investigates their idealized visions for technology leadership programs and discerns key factors differentiating authentic leadership from models incorporating BFT. Through qualitative analysis of Future-Creating Workshop outputs and participant narratives, the study unveils multifaceted themes. Participants articulate a vision of technology leadership development rooted in authenticity, intersectionality, and inclusivity. Their ideal programs prioritize celebrating complex identities, engaging through technology, and …

Authentic Fake: Authenticity And Authentication., Suyun Son

Electronic Theses and Dissertations

My thesis exhibition questions the modern sanctification of authenticity. No longer believing in objective truths, the postmodern society seeks epistemic grounding on being true to oneself. The categories of authentic-or-fake replaced the binary of true-or-false. But authenticity is a trojan horse for authentication. As a Korean American artist, I'm encouraged to express my “authentic” Korean identity. This encouragement can also imply my works will receive recognition as authentic and meaningful only when they embody Korean cultural expression. Authenticity becomes a performance for the sake of authentication. Ironically, authenticity turns into an act of conformity/confirmation. Authenticity demands you stay true to …