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Turbulence Modeling Of Shock Boundary Layer Interaction In Hypersonic Flows, Sogol Pirbastami

UNLV Theses, Dissertations, Professional Papers, and Capstones

Over the past few years, renewed interest in hypersonic research has significantly increased. Some of the most challenging obstacles in hypersonic vehicles design are associated with the shock wave turbulent boundary layer interactions (STBLI). This can cause a severe jump in pressure along with aerothermodynamic loads, which might result in structural damages or engine unstarts of hypersonic vehicles. Understanding the complex characteristics of these flows requires comprehensive physical experiments and detailed CFD turbulence modeling. In this dissertation, CFD simulations of STBLI using different turbulent modeling based on a set of experiments of hypersonic flow over a large hollow cylinder flare …

Tinyml For Gait Stride Classification, Priyanka Rajendra

UNLV Theses, Dissertations, Professional Papers, and Capstones

Human gait classification and analysis become very important when a person has been diagnosed with a neurological disorder or has suffered an injury which has affected their ability to walk correctly. Gait strides are an important parameter to be studied as it helps the doctor to diagnose any underlying gait condition and evaluate what type of treatment suits the best for the patient’s recovery. Studying gait strides also helps athletes to improve their performance.In today’s world, machine learning has emerged as one of the most widely used technology for classification and analysis of gait characteristics. TinyML is a field of …

Constructing The Perfect Girlfriend: Gender, Class, Race, & Performativity Of Paid Intimacy In Nevada Brothels, Christina Parreira

UNLV Theses, Dissertations, Professional Papers, and Capstones

While most research on commodified intimacy, especially in the sex industry, has explored gender dynamics, sex work researchers are beginning to also explore intersectional dynamics in the industry. But little research has examined whether or how workers may navigate these dynamics differently through the ways in which they understand and perform service labor. Much research has explored commodified intimacy in different settings, but very little attention has been paid to the different ways that workers in the same setting perform intimacy. In this dissertation I ask how do different performances of intimate service in the brothels- the girlfriend experience (GFE) …

The Optimum Performance Program In Sports - Youth: A Case Study, Karolyne Bastos Stucki

UNLV Theses, Dissertations, Professional Papers, and Capstones

Ethnically and racially diverse youth athletes underutilize mental health services, resulting in social and economic costs to society (Gudiño et al., 2008; Snowden & Yamada, 2005). Almost half of all children and adolescents participate in sport, and sport participation is especially common in youth from ethnically and racially diverse neighborhoods (Holt, 2008; NSCH, 2017). Therefore, sport may be an effective strategy to permit diverse youth to receive mental health services. The current case study examines The Optimum Performance Program in Sports (TOPPS; a sport-specific family behavior therapy) in an Asian American youth athlete evidencing Social Anxiety Disorder (DSM-5). A within …

Social Support Of Mexican Immigrant Women With Gestational Diabetes Mellitus: A Constructivist Grounded Theory Study, Angela Sojobi

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this study was to explore the perception of social support among Mexican immigrant women with gestational diabetes mellitus (GDM) within the context of their culture and discern the process through which social support can influence their adherence to the GDM management protocols. The incidence of GDM is highest in low-income, ethnic minority communities such as the Mexican immigrant community. Adhering to the GDM management protocols may prove challenging for some women, especially if social support is lacking. If uncontrolled, GDM can result in adverse maternal-fetal outcomes. Among Mexican immigrant women, the incidence of poor glycemic control and …

Modeling The Mechanical Behavior And Shock Propagation Of Metallic And Nanocomposite Materials, Pouya Shojaeishahmirzadi

UNLV Theses, Dissertations, Professional Papers, and Capstones

Evaluating the materials properties under different loading conditions is critical in various industries. Compared to quasi-static loading, predicting the behavior of structures under dynamic loads is more challenging. In this work, we will address multiple problems with strain rates varying from quasi-static to hypervelocity conditions. Computer simulation is increasingly used in the design and evaluation phases to improve the efficiency, cost-effectiveness, and flexibility. However, verification and validation of each simulation is necessary. Experiments are performed in all topics and the computational models are validated by comparing with the experiments. One of the most common types of connections in structures is …

Exploring Treatment Targets To Mitigate Fear Of Falling Activity Avoidance Behavior In Parkinson's Disease And Older Adults, John Vincent Rider

UNLV Theses, Dissertations, Professional Papers, and Capstones

Fear of falling (FOF) is a significant concern among individuals with Parkinson’s disease (PD) and older adults in general. This FOF can lead to avoidance behavior resulting in activity restriction. Some level of fear of falling avoidance behavior (FFAB) may be protective (adaptive) and decrease the likelihood of falls, especially among individuals with physical limitations and high fall risk. However, excessive (maladaptive) avoidance behavior may lead to downstream consequences such as further physical and psychological decline and an increased likelihood of falls, especially when there is a disparity between the FFAB and physiological fall risk. While poor physical functioning, disease …

What Do General And Organic Chemistry Students Consider When Making Decisions About Acids And Bases? A Phenomenographic Study, Sarah Wood

UNLV Theses, Dissertations, Professional Papers, and Capstones

Chemistry students often struggle in organic chemistry courses. In fact, these courses are viewed by some as “weed-out” classes. There are many fundamental concepts covered in general chemistry that contribute to students’ ability to succeed in organic chemistry. One of those fundamental topics, and the focus of this study, is the topic of acids and bases. Acid–base topics are featured in both general and organic chemistry courses, and the interests of this study lie not only within the realm of organic chemistry but also general chemistry.

The purpose of this study was to determine both undergraduate general and organic chemistry …

Investigating Acculturation, Health-Promoting Lifestyle, And Health Status Among Nigerian Immigrants In The United States, Frank Uche Akpati

UNLV Theses, Dissertations, Professional Papers, and Capstones

The United States has a significant number of immigrants from Africa. More come from Nigeria than other African countries. Even though acculturation influences health behavior in other cultures, this relationship is understudied in the Nigerian immigrant community in the United States which can influence their health care. This study examined the relationship between acculturation, health-promoting lifestyle, and health status of Nigerian immigrants. Key constructs from Berry’s acculturation model guided the study. Acculturation was conceptualized as occurring through varying levels of ethnic society immersion (ESI) and dominant society immersion (DSI). The study also examined the influence of education on acculturation using …

Axon Initial Segment Morphology Across Typical Cortical Development And In Mouse Models Of Neurodevelopmental Disorders With A High Incidence Of Epilepsy, Rachel Ali Rodriguez

UNLV Theses, Dissertations, Professional Papers, and Capstones

Neurodevelopmental disorders (NDDs) are commonly associated with a high incidence of epileptic seizures which result from excessive firing of neurons. The axon initial segment (AIS) is a neuronal compartment essential for the control of activity patterns of neurons. The AIS undergoes important modifications during development, but the molecular mechanisms that affect the development, morphology, and protein composition of the AIS are still not well understood. We examined AIS morphology of medial prefrontal cortex (mPFC) pyramidal neurons in wildtype mice across development and in two mouse models of NDDs. Results indicate restructurings at the AIS during typical development, some of which …

Rail Fixed Guideway Systems In Western U.S. Regions, Kelly A. Beavers

UNLV Theses, Dissertations, Professional Papers, and Capstones

This research explores the policy factors influencing the intraregional development of rail transit. For the purpose of this research, policy factors include: institutional arrangements, factors associated with governance, and factors in the policymaking process. The research questions are studied in five case study MSAs within the Pacific West and Mountain West regions of the United States: Phoenix-Mesa-Chandler, AZ; Denver-Aurora-Lakewood, CO; Riverside-San Bernardino-Ontario, CA; Los Angeles-Long Beach-Anaheim, CA; and Portland-Vancouver-Hillsboro, OR. The foundational problems that frame this research are the challenges of urban planning at a regional scale, specifically for transportation. The more specific challenge of transportation planning is situated within …

Numerical Studies Of Regularized Navier-Stokes Equations And An Application Of A Run-To-Run Control Model For Membrane Filtration At A Large Urban Water Treatment Facility, Jeffrey Belding

UNLV Theses, Dissertations, Professional Papers, and Capstones

This dissertation consists of two parts. The first part consists of research on accurate and efficient turbulent fluid flow modeling via a family of regularizations of the Navier-Stokes equation which are known as Time Relaxation models. In the second part, we look into the modeling application for the filtration/backwash process at the River Mountains Water Treatment Facility in Henderson, NV.

In the first two chapters, we introduce the Time Relaxation models and their associated differential filter equations. In addition, we develop the regularization method which employs the Nth van Cittert deconvolution operator, which gives rise to the family of models. …

The Spark That Lit The Match: The Use Of Petitions And The Emergence Of Antislavery Politicians In The Movement To Abolish Slavery In The District Of Columbia, 1816-1829, Timothy Brown

UNLV Theses, Dissertations, Professional Papers, and Capstones

The United States capital, Washington, D.C., became the focus of antislavery advocates in their quest to eliminate the domestic slave trade and slavery. By the War of 1812, the domestic slave trade was thriving in the capital. However, many saw it as particularly embarrassing to a nation predicated on the concept of freedom. This embarrassment was even felt by proslavery Southerners. Beginning in 1816, an attempt to restrict the trade in the Capital occurred when Virginia Congressman John Randolph called for the destruction of the domestic slave trade there. Despite being proslavery, he argued that the federal government, as the …

Physiological And Mechanical Comparisons Between Clipless And Flat Pedals, Katelyn Conroy

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this study was to investigate the physiological and mechanical comparisons between clipless and flat pedals. Participants (n=4) completed two at-home 20-minute FTP tests: using clipless and flat pedals using Zwift. The order of conditions were randomized for each participant. Participants used their personal Smart Trainers, clipless pedals, and cycling shoes while flat pedals were provided (Syun-LP, Road Bike Platform Pedals). Power, heart rate and cadence were recorded and used for analysis. All dependent variables were compared using paired t-tests. Power was significantly greater for clipless (226.7 ± 46.2 W) vs. flat (215.2 ± 41.8 W) pedals (p …

The Implementation Of Tribal Provisions From The Vawa 2013 Reauthorization, Deejay E. Chino

UNLV Theses, Dissertations, Professional Papers, and Capstones

Recent changes in VAWA allows tribes – for the first time – to prosecute non-Indians for intimate partner violence. In order to do so, however, tribes have to first meet specific federal mandates. Implementation of federal regulatory policy by American Indian tribes is a dynamic and complex process but there is a dearth of information on the challenges tribes face or on factors that would facilitate successful implementation at the tribal level. This legislation has filled a serious gap in tribal jurisprudence but not all tribes are able to meet requirements, which include having specific legal codes and justice resources. …

Identifying Risk Factors For Ptsd Symptom Clusters In Maltreated, Multiracial Youth Using Nonparametric Modeling, Mallory Constantine

UNLV Theses, Dissertations, Professional Papers, and Capstones

Multiracial youth are one of the most at-risk racial groups for child maltreatment. Multiracial individuals are also more likely to report mental health concerns than other racial or ethnic groups. This study aimed to identify demographic and psychological risk factors that are unique to multiracial, maltreated youth with respect to PTSD symptoms (i.e., re-experiencing, hyperarousal, avoidance) through classification and regression tree (CART) analyses. Participants included 99 multiracial, maltreated youth directly following their placement in an emergency group shelter due to substantiated maltreatment. The first hypothesis was that female gender, English first language, questions related to guilt and self-blame, and depressive …

Factors Influencing Us Residents' Willingness To Engage In Domestic Medical Tourism, Hananeh Derakhshan

UNLV Theses, Dissertations, Professional Papers, and Capstones

Domestic medical tourism is a niche market in the medical tourism industry. The purpose of this study was to determine the association of different attributes on U.S residents’ willingness to participate in domestic medical tourism. Based on the medical tourism index (MTI) components, a total of fourteen possible attributes that may impact US residents’ willingness to seek out-of-town care were created and participants were asked to rate the importance of each attribute on their willingness to seek out-of-town care on a 10-point Likert scale. Using principal component analysis, the attributes were grouped into three components: (1) quality-of-care, (2) destination attraction, …

Student Perceptions Of Formative Feedback In Mathematics, Derek E. Fialkiewicz

UNLV Theses, Dissertations, Professional Papers, and Capstones

There exists a plethora of quantitative studies which show the effectiveness of quality formative assessment and feedback in the classroom setting (Butler, 1987; Nyquist, 2003; Irons, 2008; Baskula, 2010; Pradana et al., 2017; Hossain, 2018; Pinger et al., 2018). Wiliam (2018) suggests the perceptions of the recipients of the feedback must be considered to determine the most effective levels of feedback. Seidman (2019) explained many researchers in the United States study education, but very few focus on the perspectives of the students and teachers, whose experiences comprise schooling. This qualitative study focuses on the perceptions of Grade 8 Pre-Algebra students …

Material Handling With Embodied Loco-Manipulation, Jean Chagas Vaz

UNLV Theses, Dissertations, Professional Papers, and Capstones

Material handling is an intrinsic component of disaster response. Typically, first responders, such as firefighters and/or paramedics, must carry, push, pull, and handle objects, facilitating the transportation of goods. For many years, researchers from around the globe have sought to enable full-sized humanoid robots to perform such essential material handling tasks. This work aims to tackle current limitations of humanoids in the realm of interaction with common objects such as carts, wheelbarrows, etc. Throughout this research, many methods will be applied to ensure a stable Zero Moment Point (ZMP) trajectory to allow a robust gait while loco-manipulating a cart. The …

How Do Beliefs Come Into Play? An Examination Of The Influence Of Core Conceptions On Science Teachers’ Inquiry Lesson Plan Designs, Mehmet Fatih Dulger

UNLV Theses, Dissertations, Professional Papers, and Capstones

Teaching science through inquiry-based methodologies has been advocated by several governmental and professional organizations (National Research Council [NRC], 2000; NGSS Lead States, 2013); however, their use is not widespread. Why is this? What science teachers do in their classrooms is shaped by their beliefs, especially their beliefs about the nature of science, about the goals and purposes of school science and the goals of teaching science, and about the teaching and learning science. By critically examining these core conceptions and their influence on teacher lesson planning, this study aims to shed light on the role conceptions play when teachers design …

Factors Associated With Medication Decision Making In African American Families Of Children With Adhd: A Mixed Methods Study, Amy Glasofer

UNLV Theses, Dissertations, Professional Papers, and Capstones

Attention-deficit/hyperactivity disorder (ADHD) is the most common neurobehavioral pediatric disorder in the United States. Pharmacotherapy is a recommended component of treatment for ADHD. While medication treatment of ADHD is not optimized overall, minority groups experience medication treatment disparities. The persistently lower rates of medication treatment in minority groups may have culturally specific origins which cannot be generalized across minorities. The purpose of this dissertation was to assess and extend knowledge regarding medication decision making (MDM) in African American caregivers of children with ADHD. To assess the state of the science on ADHD disparities, a review of 41 descriptive studies exploring …

Polyvinyl Chloride Gels: Theoretical Modeling Of Their Actuation Mechanism And Characterization Of Their Properties, Zachary Frank

UNLV Theses, Dissertations, Professional Papers, and Capstones

Polyvinyl chloride (PVC) gels are an electroactive polymer smart material which has been considered in a variety of actuator applications. Their large deformation, fast response rates, optical transparency, and soft nature has made them a key area of interest in fields ranging from soft robotics to optics. PVC gels are made from PVC mixed with large quantities of plasticizer, such as dibutyl adipate (DBA). When a voltage is applied, the gel experiences an “anodophilic” deformation (in which it moves preferentially towards the anode). This unique characteristic is the result of a charge buildup near the anode surface, which creates electromechanical …

Party Central: Networks, Influence, And Party Change In The Us House Of Representatives, Sean M. Goff

UNLV Theses, Dissertations, Professional Papers, and Capstones

For decades, scholars have devoted considerable attention to the causes and processes of party change. In this dissertation, I offer a new theoretical framework that not only takes into account the behavior of Members of Congress, but also how that behavior is constrained and conditioned by the relationships they share with other Members. This web of relationships forms a party network, the structure of which changes as Member-to-Member relationships change over time. I also identify three mechanisms of party change: a Member of Congress shifting their position to align with another (assimilation); a Member being pushed to the periphery of …

The Experience Of Self-Coherence: Self-Coherence As The Hub Of All Needs, April Ursula Fox

UNLV Theses, Dissertations, Professional Papers, and Capstones

Self-coherence as the hub of all needs is a novel proposition made by Carol Dweck (2017), and not yet further explored. While supporting self-coherence with a comprehensive review of its presence within behavioral sciences, Dweck does not dive deeper into it, and offers an invitation for further research of its workings. In this study I respond to that invitation. I design a continuation to her theory. I also expand her theory to include what I have found to be missing, but essential, additional components that cannot be ignored within the context of self-coherence as a master sensor of needs. Finally, …

The Archetypal Female Image In Chinese National Opera: A Study Of Xi Shi, Xin Guo

UNLV Theses, Dissertations, Professional Papers, and Capstones

In contrast to traditional Chinese operas, the history of Chinese National Opera1 is only a few decades long. Some scholars believe that many Chinese operas are feminist and female-centered. However, from the aesthetic standard of women’s voice to the female character’s inner world, it is hard to say that one can describe these operas as feminist simply because women play leading roles or the female arias are more than male. This document will explain the observation by analyzing the portrayal of female archetypes in Chinese national opera and discussing how opera Xi Shi complies with or subverts the portrayal. The …

How Can We Reduce Racism? A Mixed Method Study Of Factors That Influence Attitudes Towards Social Change, Kindy Insouvanh

UNLV Theses, Dissertations, Professional Papers, and Capstones

The resurgence of social movements such as Black Lives Matter has provoked public discourse about racial inequality and efforts towards social change. The current study sought to better understand how young adults reason about racism reduction with a focus on racial allyship and collective action. The present study used mixed methods to identify strategies young adults believe different racial groups could do to reduce racism and investigate the influence that individual factors have on reasoning about social change. Here, I present emergent themes to describe racism reduction strategies from a large and racially diverse sample of undergraduate students (N= 428). …

Improving Pedestrian Safety With The Implementation Of The Demand-Responsive Transverse Rumble Strip As A New Traffic Safety Countermeasure, Md Shakhawat Hossen

UNLV Theses, Dissertations, Professional Papers, and Capstones

The traditional TRS has been extensively used as a traffic calming device to provide cognitive alerts in the form of sound and vibration to drivers. However, TRS always remains fixed on the road and thus exerts cognitive alerts, irrespective of any potential downstream hazards. Moreover, the continuous exposure to rumble strips has been identified as a source of discomfort and annoyance for drivers, which limits its application to potentially useful scenarios. This study explores a rumble strip design with dynamic behavior named as Demand-Responsive Transverse Rumble Strip (DRTRS) in order to address the limitations of static TRS. The study incorporates …

The Role Of Working Memory In Fraction Arithmetic: Eye Movements During A Dual Task, Krystal Kamekona-Mendoza

UNLV Theses, Dissertations, Professional Papers, and Capstones

Fractions are first introduced at the elementary school age, yet difficulty with fraction computation (i.e., adding, subtracting, multiplying, and dividing) continues to persist throughout adulthood. Research suggests that fraction knowledge is predictive of future math achievement and success in algebra. Given the early age at which this concept is introduced and the critical role that it plays in future mathematics success, it is important to better understand the cognitive mechanisms involved in fraction computation and why students continue to struggle with this concept. The role of executive function (e.g., attention, inhibition, working memory) in fraction arithmetic is complex. While working …

Quaternary Ammonium Compounds As Precursors To Disinfection Byproducts, Padmanabhan Krishnaswamy

UNLV Theses, Dissertations, Professional Papers, and Capstones

Disinfection of drinking water is crucial for providing a safe potable water supply. Some of the most common disinfectants employed are chlorine, chloramines and ozone. While these disinfectants successfully inactivate pathogenic microorganisms, they simultaneously react with inorganic or organic precursors to form toxic byproducts, most commonly referred to as disinfection byproducts (DBPs). While there is a wide variety of organic matter and disinfection byproducts known, in this study we have looked into the potential of certain quaternary ammonium compounds (QACs) to act as precursors to form DBPs, namely trihalomethanes (THMs), haloacetonitriles (HANs) and nitrosamines.

The ubiquitous nature of QACs in …

A Human-Embodied Drone For Dexterous Aerial Manipulation, Dongbin Kim

UNLV Theses, Dissertations, Professional Papers, and Capstones

Current drones perform a wide variety of tasks in surveillance, photography, agriculture, package delivery, etc. However, these tasks are performed passively without the use of human interaction. Aerial manipulation shifts this paradigm and implements drones with robotic arms that allow interaction with the environment rather than simply sensing it. For example, in construction, aerial manipulation in conjunction with human interaction could allow operators to perform several tasks, such as hosing decks, drill into surfaces, and sealing cracks via a drone. This integration with drones will henceforth be known as dexterous aerial manipulation.

Our recent work integrated the worker’s experience into …