Theses and Dissertations
This collection includes both ASU Theses and Dissertations, submitted by graduate students, and the Barrett, Honors College theses submitted by undergraduate students.
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Description
Science, engineering, technology, and mathematics (STEM) classes are required for families in the United States. Due to this requirement, there have been more STEM focused schools present in the educational landscape. Traditionally a high school offering, middle schools are now developing more focused STEM curricula, opening STEM campuses, and creating opportunities for students to expand their STEM knowledge. Parental involvement at the middle school level can be lacking, which is also observed in STEM specific campuses. This action research study examines communication and connection with parents on a STEM middle school campus. The purpose of this study was to create a program where parents can meet once a month with each other and staff on campus to start building a thriving partnership. Ten parent participants were chosen to take part in this three-month study. Each month, participants would meet for an hour to discuss agenda items created by participants at previous meetings. The researcher employed a mixed methods design to understand connection and communication with parents on a STEM middle school campus. To analyze data, descriptive statistics were used for quantitative data, and themes were developed via grounded theory for qualitative data. Results determined that participants' views rose overall from pre to post-innovation in communication and connection. In addition to the gains seen quantitatively and qualitative data, the researcher developed three themes: connection, communication, and parent voice. Overall, the monthly parent meetings were a success overall and enhanced communication and connectivity in the STEM magnet campus. Several limitations, including a lack of diversity in the study population and researcher error, hindered this study. Suggestions for future research include replicating the study while removing the limitations seen in this study and conducting subsequent cycles of AR. Finally, suggestions for future practice indicate the vital need to involve parents in attending programs and in the design, delivery, and application of programs.
ContributorsWelch, Brian (Author) / Ross, Lydia (Thesis advisor) / Coudret, Dude (Committee member) / Marquez, Javier (Committee member) / Arizona State University (Publisher)
Created2024
Description
Late first row transitional metals have attracted attention for the development of sustainable catalysts due to their low cost and natural abundance. This dissertation discusses the utilization of redox-active ligands to overcome one electron redox processes exhibited by these base metals. Previous advances in carbonyl and carboxylate hydrosilylation using redox active ligand-supported complexes such as (Ph2PPrPDI)Mn and (Ph2PPrDI)Ni have been reviewed in this thesis to set the stage for the experimental work described herein.The synthesis and electronic structure of late first row transition metal complexes featuring the Ph2PPrPDI chelate was pursued. Utilizing these complexes as catalysts for a variety of reactions gave a recurring trend in catalytic activity. DFT calculations suggest that the trend in activity observed for these complexes is associated with the ease of phosphine arm dissociation.
Furthermore, the synthesis and characterization of a phosphine-substituted aryl diimine ligand, Ph2PPrADI-H was explored. Addition of Ph2PPrADI-H to CoCl2 resulted in C-H activation of the ligand backbone and formation of [(Ph2PPrADI)CoCl][Co2Cl6]0.5. Reduction of [(Ph2PPrADI)CoCl][Co2Cl6]0.5 afforded the precatalyst, (Ph2PPrADI)Co, that was found to effectively catalyze carbonyl hydrosilylation. At low catalyst loading, TOFs of up to 330 s-1 could be achieved, the highest ever reported for metal-catalyzed carbonyl hydrosilylation.
This dissertation also reports the first cobalt catalyzed pathway for dehydrocoupling diamines or polyamines with polymethylhydrosiloxanes to form crosslinked copolymers. At low catalyst loading, (Ph2PPrADI)Co was found to catalyze the dehydrocoupling of 1,3-diaminopropane and TMS-terminated PMHS with TOFs of up to 157 s-1, the highest TOF ever reported for a Si-N dehydrocoupling reaction. Dehydrocoupling of diamines with hydride-terminated polydimethylsiloxane yielded linear diamine siloxane copolymers as oils.
Finally, dehydrocoupling between diamines and organosilanes catalyzed by a manganese dimer complex, [(2,6-iPr2PhBDI)Mn(μ-H)]2, has allowed for the preparation of silane diamine copolymers. Exceptional solvent absorption capacity was demonstrated by the solid networks, which were found to absorb up to 7 times their own weight. Furthermore, degradation of these networks revealed that their Si-N backbones are easily hydrolysable when exposed to air. The use of lightly crosslinked copolymers as coatings was also studied using SEM analysis.
ContributorsSharma, Anuja (Author) / Trovitch, Ryan J. (Thesis advisor) / Seo, Dong-Kyun (Committee member) / Moore, Gary F. (Committee member) / Arizona State University (Publisher)
Created2024
Description
An efficient thermal solver is available in the CMC that allows modeling self-heating in the electrical simulations, which treats phonons as flux and solves the energy balance equation to quantify thermal effects. Using this solver, thermal simulations were performed on GaN-HEMTs in order to test effect of gate architectures on the DC and RF performance of the device. A Π- gate geometry is found to suppress 19.75% more hot electrons corresponding to a DC power of 2.493 W/mm for Vgs = -0.6V (max transconductance) with respect to the initial T-gate. For the DC performance, the output current, Ids is nearly same for each device configuration over the entire bias range. For the RF performance, the current gain was evaluated over a frequency range 20 GHz to 120 GHz in each device for both thermal (including self-heating) and isothermal (without self-heating). The evaluated cutoff frequency is around 7% lower for the thermal case than the isothermal case. The simulated cutoff frequency closely follows the experimental cutoff frequency. The work was extended to the study of ultra-wide bandgap material (Diamond), where isotope effect causes major deterioration in thermal conductivity. In this case, bulk phonons are modeled as semiclassical particles solving the nonlinear Peierls - Boltzmann transport equation with a stochastic approach. Simulations were performed for 0.001% (ultra-pure), 0.1% and 1.07% isotope concentration (13C) of diamond, showing good agreement with the experimental values. Further investigation was performed on the effect of isotope on the dynamics of individual phonon branches, thermal conductivity and the mean free path, to identify the dominant phonon branch. Acoustic phonons are found to be the principal contributors to thermal conductivity across all isotope concentrations with transverse acoustic (TA2) branch is the dominant branch with a contribution of 40% at room temperature and 37% at 500K. Mean free path computations show the lower bound of device dimensions in order to obtain maximum thermal conductivity. At 300K, the lowest mean free path (which is attributed to Longitudinal Optical phonon) reduces from 24nm to 8 nm for isotope concentration of 0.001% and 1.07% respectively. Similarly, the maximum mean free path (which is attributed to Longitudinal Acoustic phonon) reduces from 4 µm to 3.1 µm, respectively, for the same isotope concentrations. Furthermore, PETSc (Portable, Extensible Toolkit for Scientific Computation) developed by Argonne National Lab, was included in the existing Cellular Monte Carlo device simulator as a Poisson solver to further extend the capability of the simulator. The validity of the solver was tested performing 2D and 3D simulations and the results were compared with the well-established multigrid Poisson solver.
ContributorsAcharjee, Joy (Author) / Saraniti, Marco (Thesis advisor) / Goodnick, Stephen (Committee member) / Thornton, Trevor (Committee member) / Wang, Robert (Committee member) / Arizona State University (Publisher)
Created2024
Description
The Pennsylvania Department of Education recently adopted the new academic standards for Science, Technology & Engineering, and Environmental Literacy and Sustainability (STEELS). Scaling STEELS across the commonwealth is a challenging endeavor that depends upon local school districts' implementation of STEELS-based instruction. Therefore, it behooves local school districts to develop strategies supporting local STEELS adoption. The current action research study examined the influence of an intervention built around a Professional Learning Community (PLC) to support a local school district’s implementation of STEELS guided by the Concerns Based Adoption Model (CBAM; Hall & Hord, 2020). Four secondary science teachers from the Bellwood-Antis School District participated in a PLC. The implementation process of the PLC group was measured via the three diagnostic dimensions of CBAM: Innovation Configurations (IC), Stages of Concern (SoC), and Levels of Use (LoU). A concurrent mixed-methods action research design was employed to collect and analyze CBAM measures. The SoC dimension was measured quantitatively via the Stages of Concern Questionnaire. Individual scores were converted to a whole-group PLC SoC Profile for analysis. SoC, LoU, and IC dimensions were assessed qualitatively via semi-structured interviews. Meta-inferences were developed from combined data analysis of quantitative and qualitative data. A CBAM diagnosis for the PLC group was the primary outcome of this action research cycle, which indicated that the PLC members moved into the early phases of implementation during the intervention. Findings from the current cycle of action research informed an updated intervention game plan to be used in the next phase of implementation.
ContributorsMartin, Travis (Author) / Boutot, Amanda (Thesis advisor) / Coudret, Dude (Committee member) / Wagner, Don (Committee member) / Arizona State University (Publisher)
Created2024
Description
This dissertation examines the dynamics of research-practice partnerships (RPPs) through a qualitative multiple-case study that explores the boundary work between university researchers and K-12 practitioners. It is framed within Wenger’s communities of practice theory and focuses on the concept of ‘boundary work,’ which is pivotal in understanding the collaboration and knowledge exchange in these partnerships. The study is titled “A Tale of Two Brokers” reflecting the critical role of individuals who bridge the divide between academic and practical spheres. It argues that the concept of boundary work is critical in understanding and improving the functioning of RPPs, suggesting that more attention should be paid to the role of brokers in facilitating these partnerships. Key findings reveal that effective boundary work in RPPs is contingent on mutual respect, shared goals, and a deep understanding of each community’s values and practices. The study highlights that while researchers and practitioners often have different priorities and approaches, successful brokers can harmonize these differences to create a productive partnership. These brokers often possess qualities such as flexibility, strong communication skills, and a deep understanding of academic and practical contexts.
In conclusion, this study contributes to the broader understanding of how university researchers and K-12 practitioners can effectively collaborate. It underscores the importance of recognizing and nurturing the role of brokers in RPPs, providing valuable lessons for future collaborations between academic researchers and practitioners in various fields.
ContributorsKanavel, Kathie Ann (Author) / Boutot, Amanda (Thesis advisor) / Bowers, Nicole (Committee member) / Going, Mary Kay (Committee member) / Arizona State University (Publisher)
Created2024
Description
A high percentage of Native Hawaiian and other Pacific Islander (NHPI) adults (37.4%) aged 18 and older did not see a doctor in the past year. This is the highest percentage among all racial groups. Furthermore, approximately one in eight NHPI adults (12%) are uninsured, a rate that is markedly higher than Whites. Federal reports historically struggle to capture data that could explain these phenomena. Hence, NHPI are insufficiently and incompletely represented in health statistics, access health services at lower rates, and are insured at lower rates than other racial and ethnic minority groups. This has implications for perpetuating adverse mental health conditions and mental health disparities that are prevalent in this community (e.g., depression, anxiety, alcohol use disorder, and tobacco use), particularly following the global COVID-19 pandemic. The overarching goal of this research is to improve and broaden understanding of novel multi-level health determinants causing low mental health care service utilization rates of NHPIs, a presently understudied health disparity for Native Hawaiians and other Pacific Islanders in the U.S. Design: A closed access, cross-sectional Internet survey was used to collect data. Participants were recruited with announcements distributed nationwide via email to NHPI organizations, associations, and networks across the United States and social media. The sample included 395 NHPI adults aged 18 and older. Analysis: Latent profile analysis (LPA) were conducted using Mplus 8 statistical software to examine whether different conceptually meaningful profiles of NHPI Islanders emerge based on hypothesized health determinants measuring Symptom Distress (Perceived Health Status, Depression/Anxiety, and Perceived Stress), Protective Factors (Pacific Cultural Efficacy, Religious Centrality and Embeddedness, Pacific Connectedness and Belonging, and Perceived Societal Wellbeing) and Health Attitudes (Medical Mistrust and Service Provider Preferences [i.e., Traditional/Native Healer vs Medical Doctor/Nurse]) while accounting for demographic covariates (e.g., education, income, and insurance status). Results supported a four-profile model solution, where four distinct groups (named “Very Low Symptomatic,” “Low Symptomatic,” “Moderate Symptomatic,” and “High Symptomatic”) of participants demonstrated varying levels of symptom distress, endorsement of protective factors, and health attitudes. Furthermore, planned mental health care utilization was analyzed as an outcome variable, demonstrating varying levels of planned mental health service utilization across the four profiles. Significance: Findings may inform public policy and healthcare professionals about how to meaningfully engage NHPI communities in culturally competent mental health care services.
ContributorsMarsiglia, Steven Sasa (Author) / Dillon, Frank R (Thesis advisor) / Yellow Horse, Aggie J (Committee member) / Truong, Nancy N (Committee member) / Arizona State University (Publisher)
Created2024
Description
This dissertation examines microevolutionary changes in the Eastern Adriatic and hinterland during Roman imperialism, evaluating changing patterns of variation among indigenous groups with varying histories of acceptance or defiance to Roman rule. Despite the prevalence of Roman influence, trade, and the accommodating nature of Roman political authority administered through existing local leaders, Eastern Adriatic and hinterland peoples underwent significant cultural transformations. Unlike the Roman-allied Liburnians, Romanization was not a voluntary and amicable process for the resisting Delmatae, Histri, Japodes, and Pannonians. The violent experiences of locals during the late Republican Period and early Roman Empire, including death, enslavement, conscription, and displacement, contrast with the eventual integration of the region by the end of the Roman Empire, when their descendants were Roman citizens. These complex histories make it challenging to understand local identities and the impact of Romanization. Biological distance analyses of dental morphology from Liburnian, Delmatae, Japodes, and Pannonian samples representing 313 individuals dating to the Iron Age (c. 700- 400 BCE), and Roman Period (Roman Republic c. 200- 0 BCE; Roman Empire c. 1- 500 CE), were contextualized with archaeological data and classical research. Results indicated no significant differences within Eastern Adriatic and hinterland populations across the time periods. However, interpretations of the results for Roman Period Liburnians, descendants of Roman allies, suggest differentiation from contemporaneous Italic Romans. Conversely, the descendants of resisting populations were not statistically different from Roman Empire Italics, potentially influenced by their ancestors’ experiences of war affecting subsequent admixture, community formation, and adherence to prevailing norms.
Roman laws that managed access to advantageous status identities through marriage and citizenship may also explain the findings that all surveyed local populations demonstrate continuity between ancestors and descendants. The dynamic of being identified as Roman, and yet descending from the people who fought against Rome, is further discussed as a form of biological imperialism, consequentially shaping indigenous ancestral ties within a pan-regional Roman citizenry. While Roman multiculturalism is often considered exemplary of Antique Period diversity, Roman values prioritized diversity when it was advantageous and used pluralism to encourage cultural assimilation and define outsiders.
ContributorsLoewen, Tisa Nicolette (Author) / Stojanowski, Christopher (Thesis advisor) / Buikstra, Jane (Committee member) / Novak, Mario (Committee member) / Knudson, Kelly (Committee member) / Arizona State University (Publisher)
Created2024
Description
Southern United States English (SUSE) is North America’s most stigmatizedregionalized dialect, leading to generational decline and underrepresentation from
characters in primetime television. This study explores the representation of SUSE
features by 80 local news broadcasters in eight Southern affiliates, all outside major
metropolises. This sociophonetic study surveys the PIN-PEN merger and Stages I and II
of the Southern Vowel Shift (SVS) — /aɪ/ glide weakening and /e/-/ɛ/ proximity. The PIN-PEN merger was found to be widespread among broadcasters, with
49/80 (61%) having a PIN-PEN Pillai score less than 0.3, considered “merged”. /aɪ/ glide
weakening was subtly present, despite being a marked SUSE feature: /aɪ/ was
overwhelmingly diphthongal, but the median and Q3 variants (measured in Euclidean
distance from 20% to 80% duration) ended in the lower half of the vowel space, showing
a general lack of glide raising. Lastly, /e/-/ɛ/ proximity had marginal representation: Only
11/80 (14%) broadcasters had a non-sonorant /e/-/ɛ/ Pillai score less than 0.45, and the
median Pillai score was 0.664, establishing that an advanced SVS is not typical. The best predictors for the PIN-PEN merger were attending a Southern college,
being African American, and being male — all factors of socialization. Contrastingly, the
(mutually exclusive) best predictors of /aɪ/ glide weakening were more products of
stylization — occupational role and the subregion that hired the broadcaster (whether the
audience was a ‘Deep South’ market). For /e/-/ɛ/ proximity, the interaction of gender and
Southern college attendance was statistically significant, as only men with Southern
college backgrounds generally had this apparently stigmatized feature. Age was not found to be significant for any feature, subverting expectations that
younger speakers keep SUSE at ‘arm’s length’. TV market size was impactful for each
feature but repeatedly (narrowly) missed the p=0.05 threshold for statistical significance.
Sports anchors led in SUSE forms for each feature, showing SUSE as an asset;
investigative reporters, however, had the least SUSE /aɪ/ and /e/-/ɛ/ variants. Gender had
strong explanatory power for each feature, inferring that men tended to ‘lean in’ to
SUSE’s positive solidarity traits, but women tended to incorporate SUSE less often due
to its negative competency traits.
ContributorsDekker, Ryan Michael (Author) / Adams, Karen (Thesis advisor) / Prior, Matthew (Committee member) / Pruitt, Kathryn (Committee member) / Arizona State University (Publisher)
Created2024
Description
When Black women step into leadership roles, they confront well-documented organizational obstacles that hinder their progress. Existing research indicates that they experience differential treatment due to their intersectional identity as Black females, and these hindrances significantly impede their path to success. To increase the success of Black women in leadership roles, they need to be supported by professional development dedicated to strengthening their leadership self-efficacy. Through the theoretical lenses of intersectionality and the glass cliff phenomenon, this study investigates how an arts-based sister circle model impacts the leadership self-efficacy of Black women in leadership positions within the arts and culture sector in predominantly white organizations. Using an arts-based Experiential Learning Theory paradigm, this mixed-methods participatory action research design incorporated three virtual sister circle meetings, a participant interview, and a pre- and post-Leadership Self-Efficacy survey. Qualitative data also included digital journals, artistic reflections, and word clouds. I invited participants to join based on the following criteria: (a) Black woman, (b) manager or administrator, (c) working in a predominately white arts and culture organization such as a community arts school, art gallery, or music organization, and (d) commitment to engage in online and workplace learning experiences. Five participants throughout the United States began the study, though only two completed the innovation due to attrition connected to their work. Assertions deduced from the results were: (1) Black women face many challenges when promoted into leadership positions in predominantly white organizations, driving them to seek opportunities to network and create community with other Black women leaders; (2) Sister Circle meetings serve as community spaces providing opportunities for deep conversation and problem-solving without fear of retribution about the social, cultural, and emotional challenges they face as Black women leaders in their organizations; and (3) Participation in Sister Circle meetings may enhance leadership self-efficacy and career development and positively impact work-life balance. Survey results reinforce the sister circle model's positive influence on Black women. The findings collectively suggest that sister circles, as a coaching model, fulfill a crucial role in addressing the nuanced needs of Black women in leadership positions.
ContributorsDavis, Kimberly D (Author) / Boutot, Amanda (Thesis advisor) / Boyce, Ayesha (Committee member) / Ward, Mako F (Committee member) / Arizona State University (Publisher)
Created2024
Description
Functioning freshwater ecosystems are widely recognized as a planetary boundary for the continued human inhabitation of our planet, but little is known about the tradeoffs at the nexus of food, energy and water. In this dissertation I explored the effects of hydrologic variability in the Lower Mekong Basin (LMB) on rice production and functional structure of fish catches. I then examined the tradeoffs at the intersection of fish and rice harvest as a function of hydrologic variability and modeled production under novel engineered hydrologic scenarios. I modeled rice production using a Multivariate Autoregressive State Space (MARSS) model and mechanistically tested for the effect of saline intrusion. I found rice production to be heterogeneously affected by hydrology; in saline afflicted areas, floods had a positive effect size on production, whereas in non-saline afflicted areas, floods had a negative effect size on production. To address hydrologic filtering of the functional structure of fish catches, I collected thousands of specimens from over 100 LMB species in collaboration with Cambodia’s Inland Fisheries Research and Development institute and the Royal University of Agriculture. LMB fishes comprise a large portion of the 1,200 known species in the basin and have historically provided a substantial amount of animal protein to 60 million people in the region. Using an RLQ, co-inertia analysis, I found four functionally relevant morphological trats that were significantly associated with hydrologic variation—mouth position, maxillary length, relative body depth, and relative head depth. These traits are associated with many of the threated species in the LMB, which make up a large portion of the 1200 known species in the basin and have historically provided a substantial amount of animal protein to 60 million people in the region. To examine the tradeoffs within food systems, I used MARSS maximum likelihood estimation to forecast fish and rice production throughout the LMB under different hydrologic scenarios. I end my dissertation with an opinion piece on NexGen Mekong Scientists, a program I started in 2020 with funding from the United States Department of State.
ContributorsHolway, Joseph Henry (Author) / Sabo, John (Thesis advisor) / Grimm, Nancy (Committee member) / Holtgrieve, Gordon (Committee member) / Winemiller, Kirk (Committee member) / Hanemann, Michael (Committee member) / Arizona State University (Publisher)
Created2024