Digital Commons Network^™

2d Confinement Of Thermal Gradients In Metallic Non-Local Spin Valves, Rachel K. Bennet

Electronic Theses and Dissertations

Non-local spin valves (NLSVs) are a valuable tool in the growing field of spintronics due to their unique ability to separate charge current from pure spin current. Their potential applications as read heads for hard-disk drives, as well as use as logic gates and other spin sensors, makes detailed understanding of their behavior under a wide range of operating conditions very important.

In this dissertation, I present results of extreme thermal engineering of the supporting substrate of NLSVs, which has a dramatic impact on the background signal of the device as well as contributions from thermal spin effects such as …

Comparing Modern Day Acquisition Costs Of Trafficked Individuals: Implications For Anti-Trafficking Measures, Chelsea Reneé Dillane

Electronic Theses and Dissertations

The acquisition process of trafficked individuals varies case by case around the world, with human traffickers using various methods of acquisition and paying a range of costs to obtain these individuals. While research on the acquisition methods of traffickers is expansive, research on acquisition costs is relatively small and is mostly covered by Kevin Bales and Siddharth Kara. This study examined acquisition costs of trafficked individuals around the world in order to identify themes and patterns of acquisition, with the goal of informing preventative anti-trafficking efforts aimed at the acquisition process of human trafficking. The main finding of this research …

Developing Machine Learning Algorithms For Behavior Recognition From Deep Brain Signals, Hosein Golshan Mojdehi

Electronic Theses and Dissertations

Parkinson’s disease (PD) is a neurodegenerative condition and movement disorder that appears with symptoms such as tremor, rigidity of muscles and slowness of movements. Deep brain stimulation (DBS) is an FDA-approved surgical therapy for essential tremor and PD. Despite the fact that DBS substantially alleviates the motor signs of PD, it can cause cognitive side effects and speech malfunction mainly due to the lack of adaptivity and optimality of the stimulation signal to the patients’ current state. A behavior-adapted closed-loop DBS system may reduce the side effects and power consumption by adjusting the stimulation parameters to patients’ need.

Behavior recognition …

Satellite Constellation Deployment And Management, Joseph Ryan Kopacz

Electronic Theses and Dissertations

This paper will review results and discuss a new method to address the deployment and management of a satellite constellation. The first two chapters will explorer the use of small satellites, and some of the advances in technology that have enabled small spacecraft to maintain modern performance requirements in incredibly small packages.

The third chapter will address the multiple-objective optimization problem for a global persistent coverage constellation of communications spacecraft in Low Earth Orbit. A genetic algorithm was implemented in MATLAB to explore the design space – 288 trillion possibilities – utilizing the Satellite Tool Kit (STK) software developers kit. …

Actin Regulation And Furrow Dynamics During Early Drosophila Embryogenesis, Yi Xie

Electronic Theses and Dissertations

Drosophila embryogenesis starts with a single nucleus undergo 13 rounds of nuclear divisions called syncytial cycles. Staring at cycle 10 when nuclei migrate to the surface of the embryo, massive and dynamic cortical actin structures and cleavage furrow formations occur. How actin regulators coordinate into an organized network directing three-dimension actin structures in the developing organisms is an unsolved question. Here, I present an in-depth characterization of actin cap dynamics: the actin caps go through expansion, stabilization, elongation and fragmentation phases in each cycle. Arp2/3 is the major contributor to actin cap formation. The functions of 7 different actin and …

K-6 Saudi Arabian Teachers' Implementation Of Electronic Textbooks: Factors Associated With Behavioral Intention, Hamed Alghamdi

Graduate Research Theses & Dissertations

Teaching with digitized textbooks is a relatively new domain of education in general and is a completely new domain in Saudi Arabia. This study investigated the relationship between the Unified Theory of Acceptance and Use of Technology (UTAUT) constructs and the behavioral intention of K-6 elementary school teachers in Jeddah School District in Saudi Arabia to identify predictors of their behavioral intention toward using digitized books in their classrooms. The study employed a modified electronic UTAUT survey for data collection. The results of the study indicated a significant relationship between teachers' behavior intention and the variables of performance expectancy, effort …

Ethnic-Racial Identity And Psychological Adjustment: An Examination Of Identity Coherence And Identity Confusion As Mediators, Cara Allen

Graduate Research Theses & Dissertations

The current dissertation project investigated relationships among ethnic-racial identity, identity coherence, identity confusion, and self-esteem in an ethnic minority sample. Consistent with previous research, ethnic-racial identity was related to identity coherence. Also consistent with previous research were the findings that identity coherence and identity confusion are differentially associated with self-esteem. Mediation analysis revealed that the relationship between one form of ethnic-racial identity, ethnic-racial identity commitment, and self-esteem was mediated by identity coherence. This mediated relationship was not moderated by gender, ethnicity, or immigration status. However, the relationship between identity coherence and self-esteem was moderated by college experience.

Growth Optimization Of Zinc-Oxide Nanowires/Nanorods Using Hydrothermal Synthesis On Silicon Wafers, Mythili Ananthula

Graduate Research Theses & Dissertations

This research paper aims to grow and optically characterize the Zinc-Oxide (ZnO) nanowires grown using the hydrothermal synthesis method on different semiconductor wafers. We have developed the samples on p-type silicon, n-type silicon, and silicon di-oxide wafers at different temperatures, molarities, and times. Using hydrothermal synthesis method Zinc Oxide nanowires are grown. Zinc Nitrate Hexa-hydrate and Hexamethylenetetramine are chemical components used in the hydrothermal synthesis method at low temperatures.

Different types of analysis have been done on these samples with the help of “Argonne National Laboratory.” The optical absorption spectra were obtained using Perkin Elmer LAMBDA 950 UV-VIS-NIR Spectrophotometer. Photoluminescence …

A Phenomenological Examination Of Womanist Leadership In An Urban Community College, Cynthia Denise Armster

Graduate Research Theses & Dissertations

There is an absence of research addressing Women of Color leaders in the academy, specifically relative to the influence of their cultural identity on their leadership styles. The purpose of this study is to understand the lived experience of Women of Color leaders who served in cabinet-level positions at an urban midwestern multi-campus comprehensive community college system, how their leader persona impacted their decisions and policy-making as Women of Color leaders, and their perception of their impact and legacy in the mentoring of the next generation of Women of Color leaders within community colleges. This study is necessary to increase …

Model-Based Estimates Of The Timing Of Brine Flux Into The Victoria Land Basin From The Mcmurdo Dry Valleys, Antarctica, Valerie Nicole Voisin

Graduate Research Theses & Dissertations

Submarine groundwater discharge (SGD) at a continental scale is one of the least constrained components of the hydrologic cycle and may represent a significant flux of iron and silica waters to the global ocean. Quantifying SGD along the Antarctic margin is complicated by complex subglacial and subsurface hydrogeology and limited observational data. Airborne transient electromagnetic (AEM) surveys have identified extensive high-salinity subsurface brines in the McMurdo Dry Valleys (MDV) that are hydrologically connected to surface features in the MDV (e.g. Taylor Glacier, saline lakes) and are potentially a significant source of SGD to McMurdo Sound. A 2D numerical model was …

Telling Stories, Healing Cultures: Feminist Healing Narratives By Contemporary American Women Of Color, Lindsay Marie Vreeland

Graduate Research Theses & Dissertations

Due to their experiences of oppression as a result of intersecting identities, women of Color are the most disenfranchised by Eurocentric patriarchal accounts and typically most in need of healing. As I explore in my research, works by women writers of Color—such as Louise Erdrich’s Four Souls, Sandra Cisneros’s Have You Seen Marie?, jia qing wilson-yang’s Small Beauty, and Toni Morrison’s Home and Paradise—gathered in this dissertation intentionally question and revise white settler versions of history that devalue people of Color; however, they also revise familiar stories and cultural traditions in their own communities. Doing so both empowers and enables …

Wildlife Ecology And Conservation In A Suburban Preserve Matrix: Applications Of Long-Term Monitoring Data, John Peter Vanek

Graduate Research Theses & Dissertations

Wildlife is important to humans, offering economic, nutritional, ecological, and socio-cultural value. However, vertebrate biodiversity is being lost at rates 100 times greater than the background extinction rate, threatening human livelihood via the loss of ecosystem services. These human-induced species losses are primarily due to habitat destruction, which is increasingly tied to urban development. Conservation of wildlife resources is therefore imperative in a world where more than 50% of the human population, and 80% of people living in the United States, now live in urban areas. In this dissertation, I demonstrate how monitoring data can be applied to answer questions …

Mid-Career Elementary Teachers' Perceptions Of Elements That Contribute To Job Satisfaction And Intent To Remain In The Field, Sarah Elizabeth Westberg

Graduate Research Theses & Dissertations

This dissertation examined the experiences and perceptions of mid-career elementary teachers by exploring elements contributing to their level of job satisfaction and intent to remain in the field. Participants for the study were identified from those who responded to a questionnaire that they received via their district email addresses. All four participants were teachers with 6-17 years of teaching experience who had considered leaving the field.

Data collection strategies included a series of three interviews with each teacher, as well as responses to two writing prompts. Through analysis of the qualitative data, several common themes emerged, thus providing insight into …

Micro-Macro Mathematical Modeling Analysis Of An Al-Air Battery, Christopher Charles Welch

Graduate Research Theses & Dissertations

The aluminum-air battery is a very promising electrical energy storage system for portable electronics and electric vehicles because it is safe, inexpensive, and has a very high energy density. With the [EMIm]Cl-AlCl3 room-temperature ionic liquid (RTIL) electrolyte, by controlling the acidity, H2 evolution and dendrite formation are prevented and the Al2O3 passive film on the anode can be partially dissolved (cracked), so the battery’s lifespan is extended and even allows battery charging. Still, the Al2O3 passive film on the anode and Al2O3 deposition on the cathode remain issues which negatively affect battery performance. While these phenomena have been experimentally observed, …

Examining Reflective Practice Through Lesson Study, Amanda L. Wojcik

Graduate Research Theses & Dissertations

The purpose of this qualitative study was to examine a team of elementary teachers’ reflective practice through lesson study. The study focused on how three first-grade teachers described their reflective practice during and after lesson study and how they reflected-in, -on, and -for-action during three lesson studies. The teachers each participated in four individual interviews, three stimulated recall interviews, and observations during the lesson studies when they taught research lessons and engaged in post-lesson discussions.

Data from the interviews and lesson study observations were analyzed using qualitative methods and through the lens of Schön’s theory of reflection. Ten sub-themes were …

Shyness Mindset And Sexual Harassment Responses Among Female College Students, Jessica Rose Winder

Graduate Research Theses & Dissertations

Sexual harassment is a common problem that has negative consequences on society as a whole and on individual well-being. Confronting sexual harassers has been shown to be an effective response. Victims of sexual harassment are also encouraged to report harassment. Sexual harassment has been associated with internalizing responses, such as depression and decreased self-esteem. These responses could negatively influence confronting and reporting behaviors. This study draws from previous mindset research. Results from this prior research showed evidence that shyness mindset affects responses to peer victimization among adolescents and college students. This study hypothesized that shyness mindset among female college students …

Effects Of Differential Instructional Time In Algebra On Standardized Assessment And Semester Grade Outcomes, Michael S. Wojtowicz

Graduate Research Theses & Dissertations

Building off of other studies that examined the effectiveness of double-dose algebra programs such as Nomi and Allensworth (2009), this dissertation compared the performance outcomes of students enrolled in one of two alternatives to traditional high school algebra, a double-dose and a single-dose algebra program. This work utilized multiple linear regression to assess the degree of association between student race/ethnicity and selected demographic characteristics, including gender, free and reduced lunch status, and IEP status, on standardized assessment and end of semester mathematics course grade outcomes, while controlling for initial mathematics placement test results. This project assessed these outcomes for students …

Adaptive Object Detection For Autonomous Vehicles, Christopher Wolfe

Graduate Research Theses & Dissertations

Autonomous vehicles are gradually entering our daily lives. The goal of fully autonomous commercially available vehicles is becoming closer to reality each day as the contributions from researchers and various institutions are being added to the overall body of knowledge. Object detection is a critical component of an autonomous or semi-autonomous vehicle and draws extensively on results from many fields such as image processing and statistics. In this thesis, we consider ideas from the study of real-time computing and control systems to present a novel method of real-time adaptive object detection. We present a conceptual framework of the method as …

Fundamental Study Of Supported Metal Catalysts Prepared By Metal In Lithium Solution For Energy Science, Haiping Xu

Graduate Research Theses & Dissertations

Electrochemical carbon dioxide reduction reaction (CO2RR) is a promising technique for energy conversion and storage from intermittent electricity sources (ie. wind and solar). By coupling electrochemical CO2 reduction (CO2R) to a renewable energy source atmospheric CO2 could be converted back into a fuel such as ethanol, or a commodity chemical such as ethanol or acetic acid. These products could then be consumed for energy or used to generate more valuable chemical products effectively removing CO2 from the atmosphere. To commercialize this process, it is highly desired to prepare catalysts that selectively reduce CO2 at low overpotential with long durability. Research …

Men's Lived Experiences In A Counselor Training Program: A Phenomenological Investigation, Suzanna Marie Wise

Graduate Research Theses & Dissertations

This qualitative study explored the lived experience of seven counselors-in-training (CITs) who are men in one accredited masters-level counselor preparation program in the Midwestern United States. Over the course of a single interview that ranged in length from approximately one to two hours each, CITs were asked to describe and define their gender identity and expression, describe their experiences of being men in their families and communities, in their respective counseling programs, and as they reflect on the process of becoming a counselor in a woman-concentrated profession. Predominate gender socialization patterns in the United States in which men worked and …

Pursuing Procedural Justice In Sustainability Policy: Assessing The Linkage Between Political Culture And Municipal Efforts, Meng Yuan

Graduate Research Theses & Dissertations

How does the political culture of local governments influence the type and extent of procedural justice in sustainability policy processes? Answering this question is important because political culture is potentially a significant influence on local governments that could be better conceptualized and theorized and because public participation in sustainability policy processes is central to the demands of procedural justice in environmental justice (EJ) movements. This dissertation seeks to bring a new conception and new measures of political culture to the study of policy making by local governments as well as to contribute to developing the conceptualization and measurement of public …

Qualitative Perspectives On The Strange Trails Of Persistence In Stem, Erika Johanna Zocher

Graduate Research Theses & Dissertations

In 2019, a Midwestern state university was awarded a $1 million NSF S-STEM grant to support scholarships for academically gifted, Pell Grant-eligible undergraduates enrolled in one of six designated STEM majors. Educational research was also funded by this grant, with the goal of identifying and contextualizing supports and challenges that impact persistence in STEM within the setting of a near-peer-mentored social support group during the fall of 2019. The purpose of this group was to provide social support and foster a sense of belonging for the twelve scholars. Such support is important for guiding students towards personal development and degree …

An Examination Of Quantity And Quality Of Maternal Consulting Predicting Adolescents' Socio-Emotional Outcomes, Natalie Low

Graduate Research Theses & Dissertations

This observational investigation had two aims. The first aim examined the independent associations of the quantity and quality of maternal consulting and early adolescents’ socio-emotional outcomes. The second aim assessed the moderation effect of the quality of maternal consulting on the relationship between the quantity of maternal consulting and early adolescents’ outcomes. Seventy early adolescents (Mage=12.39 years old) and their mothers participated in the study. The sample was 51.4% girls and 48.6% boys. Mothers and their early adolescents were video recorded discussing typical hypothetical peer-related situations. Conversations were coded for the amount of consulting and four aspects of quality: feasibility, …

Modern Mandala: A Transnational History Of Southeast Asians From Burma, Malaya, And Thailand, 1950-1970., Joann Losavio

Graduate Research Theses & Dissertations

This dissertation documents cultural processes of decolonization and nation-building in the mid-twentieth century between 1950 and 1970 between Southeast Asia and the West, specifically between Burma, Malaya, Thailand, and Great Britain and the United States, as they occurred through transnational connections, migrations, spaces, and exchanges. This study proposes transnational factors were critical in such cultural processes, and proves this point through the examination of three case studies.

The first focuses on Malayan students in Great Britain in the early 1950s and how a group of them expressed anti-colonial ideas and desires for their own independent nation in a student journal, …

Copper And Gold In Vapors And Liquids As A Function Of Hcl At 700°C And 100 Mpa, Corrie A. Lucchesi

Graduate Research Theses & Dissertations

Porphyry ore deposits are major sources of copper (Cu) and gold (Au) and form when a magmatic volatile phase (MVP) exsolves from a porphyritic intermediate to felsic melt and transports metals to surrounding country rock where they precipitate in an ore zone. There is a consensus that the chloride concentration of the MVP has a direct relationship to the concentration of Cu and Au in the MVP, but the role of dissolved HCl on Cu and Au concentrations has not been addressed. It is hypothesized that increasing HCl concentrations in the MVP will result in higher concentrations of Cu and …

A Computational Study Of Binary Linear And Quadratic Programming And Solvers, William Cody Mackelfresh

Graduate Research Theses & Dissertations

In this thesis we study and compare computational capability of two solvers, Gurobi and BiqCrunch, and their capabilities to solve various binary quadratic and linear programming problems. We review two types of programming models for three types of combinatorial optimization problems, namely Max-Cut, Max Independent Set, and Max-$k$-Cluster. We also review the Reformulation-Linearization Technique (RLT) and Semidefinite Programming (SDP) approaches for solving these models, go over the software and hardware used to solve these problems, and finally review the numerical results obtained by solving the problems.

Case Study: Examining Perceptions Of Students With Low Vision In Online Courses, Asma Fuad Marghalani

Graduate Research Theses & Dissertations

This qualitative case study explored the most helpful accommodations for students with low vision in online courses. Utilizing online surveys and individual interviews, this case study took place at a U.S. public university in the Midwest. The theoretical framework for this study was Universal Design for Learning (UDL). The findings indicate that students with low vision prefer receiving text and audio information. Additionally, the findings showed that extended time was the most helpful accommodation, alternative formats for materials, headings, and color-contrasting for online content were the most helpful accessibility aspects, and screen readers were the most helpful assistive technology. The …

Implementation Of A 2d Bond Based Peridynamic Fatigue Model In Fem, Kyle Mansfield

Graduate Research Theses & Dissertations

A relatively new fracture theory known as peridynamics has been developed which uses a nonlocal theory to describe crack growth, resolving many of the issues associated to the classical continuum theory. Internal material interactions are described via a family of ‘bonds’, capable of exerting force over a macro-scale region of influence known as the horizon. Bond damage accumulates naturally due to repeated cyclic or critical loading and damage precipitates as a growing crack as bonds reach a critical damage and are severed. In the present work a modified compact tension specimen subjected to cyclic loading is modeled with the 2D …

Development Of An Electron-Beam Halo Diagnostics, Christopher James Marshall

Graduate Research Theses & Dissertations

Electron beam halos defined as the peripheral fraction of the beam that does not contribute to the front end application. Particles located in the halo can cause damage to the particle accelerator and lower the power and quality of the beam. Being able to measure the beam halo could provide insight on the halo-formation mechanism and ultimately will improve the overall performance and quality of the beam. A halo diagnostic was designed, and a prototype built and commissioned. The diagnostics relies on detecting optical radiation by the electron beam and masking its core to enhance the detection of the halo. …

Gender Differences In The Experience Of Power And The Underlying Mechanism Of Status, Jasmin Martinez

Graduate Research Theses & Dissertations

This study examines the differential experiences of men and women with regard to the possession of power. Power—or the unequal control, influence, and access to resources, people, and things—is a byproduct of the hierarchical order that forms in a multitude of social contexts. As well as being unequally held, power is also unequally exercised. This study aims to understand the differences between men’s and women’s experience of power through the lens of another hierarchical variable: social status. One area with large implications for the impact of unequal power is within the workplace. Past literature has found that women and men …