Latest content added for UNT Digital Library Collection: UNT Theses and Dissertationshttps://digital.library.unt.edu/explore/collections/UNTETD/browse/?q=&display=grid&t=fulltext&sort=creator2024-02-11T10:39:02-06:00UNT LibrariesThis is a custom feed for browsing UNT Digital Library Collection: UNT Theses and DissertationsDiscriminative Control of Behavioral Variability in Video Game Play2024-02-11T10:39:02-06:00https://digital.library.unt.edu/ark:/67531/metadc2280433/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc2280433/"><img alt="Discriminative Control of Behavioral Variability in Video Game Play" title="Discriminative Control of Behavioral Variability in Video Game Play" src="https://digital.library.unt.edu/ark:/67531/metadc2280433/small/"/></a></p><p>Creativity can be a useful skill in today's classrooms and workplaces. When individuals talk about creativity, it's unclear what the controlling variables are when we tact behavior as "creative." Research in understanding the processes behind behaviors that are considered "creative" would assist in identifying functional relations and provide insight on how to teach creativity. Since creativity is often described as doing something different from the norm, behavioral variability may be a potential aspect of creativity. This study aimed to replicate previous findings by investigating the effects of discrimination training in a multiple schedule of varied and repetitive responding in the context of a video game. Participants played through a 2D online video game made in Bloxels. Different alternating-colored platforms served as the discriminative stimuli for the vary and repeat components. Three parameters of variability were measured (e.g., left jumps, right jumps, and double jumps). The results of the study indicate that participants were able to learn the discrimination of when to repeat and vary their responses depending on which colored platform they encountered.</p>Analysis of "The Seven Songs" From The Pilgrim's Progress By Ralph Vaughan Williams2024-02-11T10:38:49-06:00https://digital.library.unt.edu/ark:/67531/metadc2280432/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc2280432/"><img alt="Analysis of "The Seven Songs" From The Pilgrim's Progress By Ralph Vaughan Williams" title="Analysis of "The Seven Songs" From The Pilgrim's Progress By Ralph Vaughan Williams" src="https://digital.library.unt.edu/ark:/67531/metadc2280432/small/"/></a></p><p>The opera, The Pilgrim's Progress, was written by Ralph Vaughan Williams in 1949. "The Seven Songs" are analyzed for performance, examining the elements of music and text of the songs, including melody, harmony, form, vocal line and accompaniment, with the intent of forming conclusions in regard to their usefulness as singular selections, or as a group, for performance.</p>Additive Friction Stir Deposition of Al-Ce Alloys for Improved Strength and Ductility2024-01-27T22:23:48-06:00https://digital.library.unt.edu/ark:/67531/metadc2257751/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc2257751/"><img alt="Additive Friction Stir Deposition of Al-Ce Alloys for Improved Strength and Ductility" title="Additive Friction Stir Deposition of Al-Ce Alloys for Improved Strength and Ductility" src="https://digital.library.unt.edu/ark:/67531/metadc2257751/small/"/></a></p><p>Additive friction stir deposition (AFSD) is a solid-state additive manufacturing (AM) technique that breaks down large constituent particles into more refined and uniformly disturbed microstructure. AFSD was used to print Al-Ce alloys. Current commercial Al-alloys upon elevated temperatures go through dissolution and coarsening of strengthening precipitates causing mechanical degradation of these alloys. Al-Ce alloys do not have this issue as cerium's low solubility restricts dissolution into the aluminum matrix at elevated temperatures, thus giving great thermal stability to the microstructure. Al-Ce alloys lack solid solubility that affects the solid solution strengthening and precipitation strengthening. Al-Ce alloys have limitation at room temperature as they can only reach a maximum of ~65 MPa yield strength. Elements like magnesium have been added to alloy to enable solid solution strengthening, and scandium to enable precipitation strengthening to improve strength before going through the AFSD process. By adding new elements to the Al-Ce alloys, an increase in the yield strength from ~60 MPa to ~200 MPa was achieved before AFSD. The casted alloys form coarse particles that reach 300 µm in size; resulting in stress concentration that causes material fracture before necking, giving >10% ductility. AFSD breaks down these coarse particles to increase strength and ductility increases. The particles were broken down to >20 µm which increased the ductility to 10%. The results of this research shows that Al-Ce alloys are able to reach commercial aluminum alloy mechanical standards of 400 MPa ultimate tensile strength and 10% ductility at room temperature for aerospace applications.</p>Utility Trombone Playing: A Practical Method for Students to Achieve Mastery of Alto, Tenor and Bass Trombone2024-01-27T22:22:57-06:00https://digital.library.unt.edu/ark:/67531/metadc2257750/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc2257750/"><img alt="Utility Trombone Playing: A Practical Method for Students to Achieve Mastery of Alto, Tenor and Bass Trombone" title="Utility Trombone Playing: A Practical Method for Students to Achieve Mastery of Alto, Tenor and Bass Trombone" src="https://digital.library.unt.edu/ark:/67531/metadc2257750/small/"/></a></p><p>With the importance of versatility in freelance work in the world of trombone performance, along with increased competition for that work, the need for players to play alto, tenor, and bass trombones to a high level of proficiency has become more and more crucial. This, coupled with the growing number of orchestras looking to hire musicians who are highly competent on all three instruments means that university professors need to be able to teach all three instruments. This evolution of the job market is driving a need for pedagogical material that is specifically designed to address the unique challenges of practicing and performing at a professional level on the main three instruments in the trombone family. As of the time of writing, this material simply does not exist. This project aims to fill that instructional gap. It gives students and teachers a resource that outlines an approach for a four-year undergraduate course of study that allows for the development of the playing of each of the trombones individually and collectively, utilizing the strengths of one instrument to develop the other two. It will also allow for the exploration of the technical challenges that arise when playing and changing between instruments. This four-year course of study combined with a clear explanation of numerous routines can be used from early in a student's development. It can be tailored to their specific needs and will give any teacher and student a comprehensive and holistic method for the acquisition of the skills needed to become a successful utility trombonist.</p>Experimental and Numerical Investigation of a Novel Cold-Formed Steel Long Span Truss2024-01-27T22:22:06-06:00https://digital.library.unt.edu/ark:/67531/metadc2257749/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc2257749/"><img alt="Experimental and Numerical Investigation of a Novel Cold-Formed Steel Long Span Truss" title="Experimental and Numerical Investigation of a Novel Cold-Formed Steel Long Span Truss" src="https://digital.library.unt.edu/ark:/67531/metadc2257749/small/"/></a></p><p>This thesis describes the experimental and numerical investigation of a novel cold-formed steel 48ft and 54ft long span truss. The truss we designed was to be used as the roofs of large buildings, such as warehouses, hangars, sports arenas. The investigation includes both experimental and numerical testing, the experimental testing of the truss under uniform loads (increasing loads) to determine its deflection and load carrying capacity. The numerical test included developing a finite element model of the truss in SolidWorks and using a finite element model of the truss in ABAQUS to simulate the experimental tests. The findings of this study can be used to improve the design of cold-formed steel long span trusses. The study also provides valuable information for future studies on the modeling of trusses with different cold-formed steel members and the behavior of trusses under load.</p>Exploring the ROI of 1:1 Computing Programs at the High School Level2024-01-27T22:21:58-06:00https://digital.library.unt.edu/ark:/67531/metadc2257748/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc2257748/"><img alt="Exploring the ROI of 1:1 Computing Programs at the High School Level" title="Exploring the ROI of 1:1 Computing Programs at the High School Level" src="https://digital.library.unt.edu/ark:/67531/metadc2257748/small/"/></a></p><p>This dissertation explored the cost and value of 1:1 computing programs in high schools in Texas. The study examines whether the total cost of ownership of these programs can be justified by the student testing gains and graduation rates. It investigates whether student learning outcomes show a definable correlation between positive gains and the implementation of 1:1 computing programs. The study also explores whether there is a measurable return on investment of 1:1 programs based on testing gains and graduation rates. The research used the State of Texas Assessment of Academic Readiness exam scores to validate assumptions and test the hypothesis. The study found no clear link between the addition of 1:1 computing programs and the realms of student success. While there is marginal improvement in student outcomes, there is only circumstantial evidence that laptops and devices are the catalysts for the change. The dissertation also found that the total cost of ownership (TCO) is a significant portion of the district's spending, costing millions of dollars, and that the financial disclosure and budget information data was either missing, incomplete, or over-generalized, causing an issue for assessing program effectiveness or ROI. Despite this lack of transparency, there is a slight positive ROI trend based on the data reviewed during the observation period.</p>Magnetoresponsive Layer-by-Layer (LBL) Polyelectrolyte Microcapsules Exposed to Low Frequency Alternating Magnetic Field for Drug Delivery to Breast Cancer Cells2024-01-27T22:21:45-06:00https://digital.library.unt.edu/ark:/67531/metadc2257747/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc2257747/"><img alt="Magnetoresponsive Layer-by-Layer (LBL) Polyelectrolyte Microcapsules Exposed to Low Frequency Alternating Magnetic Field for Drug Delivery to Breast Cancer Cells" title="Magnetoresponsive Layer-by-Layer (LBL) Polyelectrolyte Microcapsules Exposed to Low Frequency Alternating Magnetic Field for Drug Delivery to Breast Cancer Cells" src="https://digital.library.unt.edu/ark:/67531/metadc2257747/small/"/></a></p><p>Layer-by-layer (LBL) polyelectrolyte capsules can be modified to incorporate stimuli such as superparamagnetic nanoparticles which respond to a magnetic field only when it is turned on. Thus, they can act as a switch to load or unload their drug cargo on demand. Specifically, magnetite is incorporated into bilayer capsules made of alternating poly(allylamine hydrochloride) (PAH) and poly(sodium-p-styrenesulfonate) (PSS) which surrounds calcium carbonate core. The core is then dissolved using ethylenediaminetetraacetic acid (EDTA). These capsules are loaded with at FITC-BSA conjugate and examined with fluorescence to show the unloading of the FITC-BSA from capsules as it brightens the entire field of view of the microscope. The results suggest that we can next load and unload an anticancer drug such as doxorubicin using the combination of microcapsule and alternating magnetic field (AMF) to treat the cancer cells. Preliminary data interprets that the low frequency AMF we use has little to no adverse effect cells viability. This coincides with the general thought that low frequency AMF signals are not harmful to humans. Therefore, as an alternative to hyperthermia methods which use heat, it may be possible to deliver the anticancer drugs specifically to the cells when and where it is needed.</p>The Idiomatic Techniques and Procedures of Composer Kevin Walczyk (b. 1964) that Define a Unique Musical Language2024-01-27T22:20:21-06:00https://digital.library.unt.edu/ark:/67531/metadc2257746/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc2257746/"><img alt="The Idiomatic Techniques and Procedures of Composer Kevin Walczyk (b. 1964) that Define a Unique Musical Language" title="The Idiomatic Techniques and Procedures of Composer Kevin Walczyk (b. 1964) that Define a Unique Musical Language" src="https://digital.library.unt.edu/ark:/67531/metadc2257746/small/"/></a></p><p>Award winning composer Kevin Walczyk's describes himself as a "musical storyteller," using all musical elements of structure, melody, harmony, and counterpoint to convey programmatic content. A variety of subjects are conveyed that include historical events, people, physical objects or locations, and literary texts. Deeper matters, such as spiritual themes, are also often incorporated in his music that enhance the musical program. The technical procedures employed—pertaining particularly to the expression of programmatic content—has produced a unique musical language that stands out in the modern compositional landscape. What are these inherent idiomatic features, and how are they exhibited? The purpose of this dissertation is to provide a detailed examination of Walczyk's distinct musical language. A critical analysis of the technical procedures used to convey his programmatic content, as well as insights into his influences and writing process, illuminate the attributes of this a posteriori musical language. The two works selected for this study to demonstrate this are Symphony No. 2: Epitaphs Unwritten and Talking Winds, both written for wind band.</p>"To Swim In Air Forever Tooloud Laughcrying"2024-01-27T22:20:16-06:00https://digital.library.unt.edu/ark:/67531/metadc2257745/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc2257745/"><img alt=""To Swim In Air Forever Tooloud Laughcrying"" title=""To Swim In Air Forever Tooloud Laughcrying"" src="https://digital.library.unt.edu/ark:/67531/metadc2257745/small/"/></a></p><p>This thesis' focal presentable object – to swim in air – is a mythosystem comprising six iteratively malleable experiential systems of intermedial musical and visual performance works composed by myself between the years 2018 and 2023. Conceived through the lens of Jennifer Walshe's New Discipline, created within my practice cycle's nodal context, and connected by a sub/conscious structure of perceptual timbre, the mythosystem and its parts form the centerpiece of this discussion of context, process, and method. As described in this document, the creative practice of nodal context and the adaptive intermedial methods used in the conceptualization and composition of to swim in air were developed through a personal and pragmatic application of feminist writer and independent scholar Sarah Ahmed's Queer Phenomenology: Orientations, Objects, Others, and composer, musicologist and trombonist George Lewis' curatorial decolonization guidelines as outlined in his "8 Difficult Steps to Decolonizing Music" towards the creation of presentable cultural objects which invite variable and continuous interaction from their participants through the exploration of the reciprocity of community, multi-practice creative strategy and malleable forms. Throughout this document I discuss how through the exploration of the reciprocity of community, multi-practice creative strategy and malleable forms I have addressed concerns of cost, access and participation in living culture with regards to my own work creating cultural objects. I also discuss phenomenological and practical issues to do with cost, access and living culture present within the creative, curatorial and institutional spaces and communities in which this work was created and is initially intended to exist, and how these concerns impact the pedagogical, practical and experiential potential of my own work. This document also reflects on how the pragmatic and personal adoption of these concepts of cultural object phenomenological ephemera and decolonized curatorial practice as presented by Ahmed and Lewis by other composers, artist, curators, educators, and other creative professionals might impact the nature of artistic institutional spaces, might encourage the engagement of new, speculative and/or more colloquial spaces, and how these spatial reorientations might encourage a more fluidic approach to creative practice, community cultivation and engagement.</p>Thermodynamics, Kinetics and Mechanical Behavior of Model Metallic Glasses2024-01-27T22:19:57-06:00https://digital.library.unt.edu/ark:/67531/metadc2257744/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc2257744/"><img alt="Thermodynamics, Kinetics and Mechanical Behavior of Model Metallic Glasses" title="Thermodynamics, Kinetics and Mechanical Behavior of Model Metallic Glasses" src="https://digital.library.unt.edu/ark:/67531/metadc2257744/small/"/></a></p><p>The thermophysical properties and deformation behavior of a systematic series of model metallic glasses was investigated. For Zr-based metallic glasses with all metallic constituents, the activation energy of glass transition was determined to be in the range of 74-173 kJ/mol while the activation energy of crystallization was in the range of 155-170 kJ/mol. The reduced glass transition temperature was roughly the same for all the alloys (~ 0.6) while the supercooled liquid region was in the range of 100-150 K, indicating varying degree of thermal stability. In contrast, the metal-metalloid systems (such as Ni-Pd-P-B) showed relatively higher activation energy of crystallization from short range ordering in the form of triagonal prism clusters with strongly bonded metal-metalloid atomic pairs. Deformation mechanisms of all the alloys were investigated by uniaxial compression tests, strain rate sensitivity (SRS) measurements, and detailed characterization of the fracture surface morphology. For the metal-metal systems, plasticity was found to be directly correlated with shear transformation zone (STZ) size, with systems of larger STZ size showing better plasticity. In metal-metalloid amorphous alloys, plasticity was limited by the distribution of STZ units, with lower activation energy leading to more STZ units and better plasticity. The alloys with relatively higher plasticity showed multiple shear bands while the brittle alloys showed a single dominant shear band and vein-pattern on the fracture surface indicating sudden catastrophic failure. The effect of chemistry change on thermodynamics, kinetics, and deformation behavior was investigated for the model binary NixP100-x and CoxP100-x metallic glasses. Alloys with higher phosphorous content showed greater activation energy of crystallization, indicating better thermal stability. In addition, metallic glasses with higher % P showed greater hardness, modulus, and serrated flow behavior during indentation that is characteristic of inhomogeneous deformation.</p>Building a Digital Twin of the University of North Texas Using LiDAR and GIS Data2024-01-27T22:17:00-06:00https://digital.library.unt.edu/ark:/67531/metadc2257743/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc2257743/"><img alt="Building a Digital Twin of the University of North Texas Using LiDAR and GIS Data" title="Building a Digital Twin of the University of North Texas Using LiDAR and GIS Data" src="https://digital.library.unt.edu/ark:/67531/metadc2257743/small/"/></a></p><p>Digital twins are virtual renditions of the actual world that include real-world assets, connections, activities, and processes. Recent developments in technologies play a key role in advancing the digital twin concept in urban planning, designing, and monitoring. Moreover, the latest developments in remote sensing technology have resulted in accurate city-scale light detection and ranging (LiDAR) data, which can be used to represent urban objects (buildings, vegetation, roads, and utilities), enabling the creation of digital twin of urban landscapes. This study aims to build a digital twin of the University of North Texas (UNT) using LiDAR and GIS data. In this research, LiDAR point clouds are used to create 3D building and vegetation modeling along with other GIS data (bicycle racks and parking areas) in creating a digital twin model. 3D Basemap solutions of ArcGIS Pro and ArcGIS Online Scene Viewer, respectively, are used to create an initial 3D urban model and build the ultimate digital twin of UNT. The emergency management floorplans of UNT buildings are incorporated into the digital twin to increase emergency management efficiency. Moreover, solar power potential for individual buildings at UNT has been estimated using the Digital Surface Model (DSM) and integrated into the digital twin model to identify the buildings with the highest solar energy capacity. This study indicates that implementing a digital twin in a university enhances campus efficiency, safety, and sustainability, serving as a central system for a smart campus and contributing to intelligent urban growth.</p>"The Gordita's Guide to Body Positivity"2024-01-27T22:16:50-06:00https://digital.library.unt.edu/ark:/67531/metadc2257742/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc2257742/"><img alt=""The Gordita's Guide to Body Positivity"" title=""The Gordita's Guide to Body Positivity"" src="https://digital.library.unt.edu/ark:/67531/metadc2257742/small/"/></a></p><p>"The Gordita's Guide to Body Positivity" is an autobiographical documentary reflecting on society's expectations of the female body image and how it affects Latinx women. Through personal recollections, media content, and archival material, the film explores beauty expectations, body discrimination, and body positivity. The document analyzes the documentary styles such as autoethnography and narration incorporated into the film and provides historical and theoretical context to body image in the Latinx culture and how the media has affected body image, beauty ideals, and eating disorders. In addition, the pre-production, production, and post-production process is detailed.</p>Option Pricing Under New Classes of Jump-Diffusion Processes2024-01-27T22:15:49-06:00https://digital.library.unt.edu/ark:/67531/metadc2257741/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc2257741/"><img alt="Option Pricing Under New Classes of Jump-Diffusion Processes" title="Option Pricing Under New Classes of Jump-Diffusion Processes" src="https://digital.library.unt.edu/ark:/67531/metadc2257741/small/"/></a></p><p>In this dissertation, we introduce novel exponential jump-diffusion models for pricing options. Firstly, the normal convolution gamma mixture jump-diffusion model is presented. This model generalizes Merton's jump-diffusion and Kou's double exponential jump-diffusion. We show that the normal convolution gamma mixture jump-diffusion model captures some economically important features of the asset price, and that it exhibits heavier tails than both Merton jump-diffusion and double exponential jump-diffusion models. Secondly, the normal convolution double gamma jump-diffusion model for pricing options is presented. We show that under certain configurations of both the normal convolution gamma mixture and the normal convolution double gamma jump-diffusion models, the latter exhibits a heavier left or right tail than the former.
For both models, the maximum likelihood procedure for estimating the model parameters under the physical measure is fairly straightforward; moreover, the likelihood function is given in closed form thereby eliminating the need to embed a probability density function recovery procedure such as the fast Fourier transform or the Fourier-cosine expansion methods in the parameter estimation procedure. In addition, both models can reproduce the implied volatility surface observed in the options data and provide a good fit to the market-quoted European option prices.</p>Exploring the Association of Language Brokering and Parent-Child Relationship in Korean Immigrant Families2024-01-27T22:15:48-06:00https://digital.library.unt.edu/ark:/67531/metadc2257740/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc2257740/"><img alt="Exploring the Association of Language Brokering and Parent-Child Relationship in Korean Immigrant Families" title="Exploring the Association of Language Brokering and Parent-Child Relationship in Korean Immigrant Families" src="https://digital.library.unt.edu/ark:/67531/metadc2257740/small/"/></a></p><p>This study focuses on investigating the dynamics of language brokering as Korean immigrant families experience environmental challenges associated with immigration. This study was conducted with qualitative research design with purposive sampling of Korean immigrant families. Six parent-child dyads were recruited and participating children were between 12 to 16 years old. Semi-structured interviews were conducted separately with parents and children in either English or Korean. Thematic analysis was employed for analyzing the transcribed interviews. The Dedoose software program was applied to assist the coding process. 12 subthemes were revealed under four main themes, which were aligned to the study's research questions. The twelve subthemes included parents' dependence on children, vulnerability and resilience of Korean immigrant families, children's socioemotional development through language brokering, and the role of first-born daughter in the family. Parent and child responses indicated how language brokering affects can be a risk in relation to children's development (i.e., with responsibility of language brokering leading the child to experience stress or experience the responsibility of translation as a burden. Positively, respondents indicated that the parent and child experienced a greater sense of empathy for each other's roles. The results derived from this study were aligned with the results of previous research conducted in the field in that language brokering affects parent-child relationship and the socioemotional development of children. The study adds to the literature with the interviewing both parents and children, thereby hearing both perspectives and experiences of parents and children on language brokering and parent-child relationships could be obtained. This study targeted Korean immigrant families since there is a lack in literature that have studied this population in relation to language brokering.</p>Rethinking the Study of Conflict and Peace: Making Causal Inferences in Quantitative Conflict and Peace Research2024-01-27T22:15:26-06:00https://digital.library.unt.edu/ark:/67531/metadc2257739/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc2257739/"><img alt="Rethinking the Study of Conflict and Peace: Making Causal Inferences in Quantitative Conflict and Peace Research" title="Rethinking the Study of Conflict and Peace: Making Causal Inferences in Quantitative Conflict and Peace Research" src="https://digital.library.unt.edu/ark:/67531/metadc2257739/small/"/></a></p><p>Most research questions and theory in quantitative peace and conflict research are fundamentally causal. However, a large gap exists in the extant literature between research question and research methodology. Not only does most existing methodology fail to achieve what most quantitative peace scholars attempt, but many researchers do not appear to be aware of these limitations. In this dissertation, I outline five key shortcomings within this literature that, left unaddressed, create results that are not informative of the questions quantitative peace researchers are interested in. This dissertation demonstrates solutions addressing these shortcomings with two applied chapters, conducting causal research designs on a study examining the economic impact of United Nations peacekeeping operations and the effect of human rights treaties on repression, respectively. I find that conventionally-established results in the literature change dramatically when exposed to methodological changes informed by the causal inference literature.</p>Investigating Novel Streptomyces Bacteriophage Endolysins as Potential Antimicrobial Agents2024-01-27T22:13:53-06:00https://digital.library.unt.edu/ark:/67531/metadc2257738/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc2257738/"><img alt="Investigating Novel Streptomyces Bacteriophage Endolysins as Potential Antimicrobial Agents" title="Investigating Novel Streptomyces Bacteriophage Endolysins as Potential Antimicrobial Agents" src="https://digital.library.unt.edu/ark:/67531/metadc2257738/small/"/></a></p><p>As antibiotic resistance has become a major global threat, the World Health Organization has urgently called scientists for alternative strategies for control of bacterial infections. Endolysin, a protein encoded by a phage gene, can degrade bacterial peptidoglycan (PG). Currently, there are three endolysin products in the clinical phase. We, thus, are interested in exploring novel endolysins from Streptomyces phages as only a few of them have been experimentally characterized. Using bioinformatics tools, we identified nine functional domain groups from 250 Streptomyces phages putative endolysins. NootNoot gp34 (transglycosylase; Nt34lys), Nabi gp26 (amidase; Nb26lys), Tribute gp42 (PGRP; Tb42lys), and LazerLemon gp35 (CHAP; LL35lys) were selected for experimental studies. We hypothesized that (1) the proteins of interest will have the ability to degrade PG, and (2) the proteins will be potential antimicrobial agents against ESKAPE safe relatives. The results showed that LL35lys, Nb26lys and Tb42lys exhibit PG-degrading activity on zymography and hydrolysis assay. The enzymes (400 µg/mL) can reduce PG turbidity to 32-40%. The killing assay suggested that Tb42lys possess a boarder range (Escherichia coli, Pseudomonas putida, Acinetobacter baylyi and Klebsiella aerogenes). While Nb26lys can attack Gram-negative bacteria, LL35lys can only reduce the growth of the Gram-positive strains with an MIC90 of 2 µg/mL. A higher concentration (≥300 µg/mL) of Nb26lys is needed to treat P. putida and K. aerogenes. Therefore, endolysins from Streptomyces phage have potential as possible antimicrobial agents against ESKAPE bacteria.</p>The Effects of Implementing a Reward-Based Version of Ostrom's Eight Design Principles as an Intervention Package on Responses in a Common Pool Resource (CPR) Game2024-01-27T22:12:28-06:00https://digital.library.unt.edu/ark:/67531/metadc2257737/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc2257737/"><img alt="The Effects of Implementing a Reward-Based Version of Ostrom's Eight Design Principles as an Intervention Package on Responses in a Common Pool Resource (CPR) Game" title="The Effects of Implementing a Reward-Based Version of Ostrom's Eight Design Principles as an Intervention Package on Responses in a Common Pool Resource (CPR) Game" src="https://digital.library.unt.edu/ark:/67531/metadc2257737/small/"/></a></p><p>The aim of behavior analysis has always been to apply technologies rooted in basic behavioral principles to problems of societal importance (e.g., Skinner, 1948; 1953; 1987). One such problem is the Tragedy of the Commons - a phenomenon arising from systemic failures among a community, leading to the total collapse of a critical resource (Hardin, 1968). Elinor Ostrom's Eight Design Principles were developed to provide a framework for the self-management of common pool resources (CPRs; Ostrom, 1990/2015). When applied as an independently manipulated variable, Ostrom's design principles have shown strong effects in the management of CPRs within the context of a tabletop board game Catan® (Smith & Becker, 2023). This preparation included both rewards (i.e., positive reinforcement) and sanctions (i.e., positive punishment) as a feature of the independent variable. However, it has been well documented that punishing and coercive contingencies can lead to problematic outcomes for individuals and societies (e.g., Sidman, 2001; Skinner, 1976). This study evaluated the effects of utilizing only rewarding consequences in lieu of sanctions in an effort to produce the previously observed control over self-management of a CPR, utilizing the previously adapted rules of the Catan® board game.</p>The Effect of Restructuring of Peer Firms on Investment2024-01-27T22:11:11-06:00https://digital.library.unt.edu/ark:/67531/metadc2257736/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc2257736/"><img alt="The Effect of Restructuring of Peer Firms on Investment" title="The Effect of Restructuring of Peer Firms on Investment" src="https://digital.library.unt.edu/ark:/67531/metadc2257736/small/"/></a></p><p>Firms' operational restructuring involves information relevant to strategic choices as well as future demand and cost conditions. This study examines the relationship between peer firms' restructuring and a company's responsiveness to its growth opportunities. Peer firm restructuring can increase uncertainty with respect to a company's payoffs regarding its investment projects, leading to decreased responsiveness to growth opportunities. Using a large sample of public companies during 2006–2020, I find that peer firms' restructuring is negatively associated with the responsiveness of capital expenditures (Capex) to growth opportunities. The results suggest that peer firms' restructuring activities provide information about a company's investment projects above and beyond industry shocks reflected in changes in industry sales. Furthermore, these associations are moderated by industry competition. The negative effects of peer firms' restructuring on Capex sensitivity are the strongest in high-competition industries.</p>"Google is my friend": An Exploration of Older Adult Media Literacy2024-01-27T22:11:01-06:00https://digital.library.unt.edu/ark:/67531/metadc2257735/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc2257735/"><img alt=""Google is my friend": An Exploration of Older Adult Media Literacy" title=""Google is my friend": An Exploration of Older Adult Media Literacy" src="https://digital.library.unt.edu/ark:/67531/metadc2257735/small/"/></a></p><p>The advancement and incorporation of media in daily life continue to grow exponentially as the median age of humanity continues to rise. While there are media literacy education programs targeted toward children and adolescents, older adults are often left out of these initiatives. Based on ethnographic research conducted at two senior centers in Denton, TX, this thesis explores the way older adults analyze and interact with media. Data collection methods include participant observation and semi-structured interviews with senior center members over the age of 65. The research findings highlight how older adults navigate an expanding information society and how they lean on their community for support. These findings laid the foundation for the creation of a media literacy educational seminar given at both senior centers.</p>Green Manufacturing of Lignocellulosic Fiber through Bacterial Degradation Process2024-01-27T22:10:06-06:00https://digital.library.unt.edu/ark:/67531/metadc2257734/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc2257734/"><img alt="Green Manufacturing of Lignocellulosic Fiber through Bacterial Degradation Process" title="Green Manufacturing of Lignocellulosic Fiber through Bacterial Degradation Process" src="https://digital.library.unt.edu/ark:/67531/metadc2257734/small/"/></a></p><p>Lignocellulose is the most abundant biopolymer on earth and offers excellent potential for sustainable manufacturing. Because lignocellulose is structurally complex and resistant to decomposition, innovative degradation strategies are necessary to unlock its value. In this dissertation, a green manufacturing process through enzyme-triggered self-cultured bacteria retting for lignocellulosic fiber was developed and investigated. The mechanism of the lignocellulosic fiber retting at a controlled degradation strategy was studied. This enzymatic degradation strategy utilizes a small amount of enzyme to trigger a large aggregation of specific bacteria to obtain clean fibers. Industrial hemp (Cannabis sativa L.) fiber was successfully retted with this strategy. The degradation of pectin was proved through an environmental scanning electron microscope and reducing sugar analysis. The bacterial successions were identified by 16S rRNA gene metagenomic sequencing. The results showed that Bacillaceae dominated the hemp retting conditions containing 1% pectinase, suggesting that pectinase can manipulate bacterial community succession by changing the nutrients available to bacteria through the degradation of pectin. This degradation strategy has 20-25% less environmental impact than the thermochemical degradation strategy, resulting in better fiber consistency and much shorter processing time (3-5 days) than the traditional water degradation strategy. The study on the degradation of lignin-rich lignocellulose also contributes to the understanding of the natural formaldehyde release mechanisms from wood.</p>Saxophone Instruction by Women: Experiences of Achieving the Rank of Full Professor at Post-Secondary Institutions in the United States2024-01-27T22:09:48-06:00https://digital.library.unt.edu/ark:/67531/metadc2257733/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc2257733/"><img alt="Saxophone Instruction by Women: Experiences of Achieving the Rank of Full Professor at Post-Secondary Institutions in the United States" title="Saxophone Instruction by Women: Experiences of Achieving the Rank of Full Professor at Post-Secondary Institutions in the United States" src="https://digital.library.unt.edu/ark:/67531/metadc2257733/small/"/></a></p><p>Since the first saxophone professor at the Paris Conservatory in 1858, saxophone instruction has primarily been a male-dominated field. Numerous sources detail the experiences, lives, and influence of male post-secondary saxophone instructors. Women have made great strides in the performance and instruction of the saxophone at the post-secondary level, but sources discussing their lives and experiences are limited. Saxophone instruction at the post-secondary level in the United States began in the late 1800s. As the instrument grew in popularity through the 20th century, more and more higher education institutions began incorporating the saxophone as an instrument for primary study. This increased the need for saxophone professors in the United States. In 1994, Elizabeth Zinn Ervin, became the first woman full professor. This was 40 years after the the first man, Larry Teal, held this rank. As of 2023, 15 women have achieved the rank of full professor. This document is intended to highlight several women saxophone instructors throughout the history of the instrument, and detail the thoughts and experiences of women saxophonists who have achieved the rank of full professor in the United States.</p>Mesenchymal Stem Cells Encapsulated and Aligned in Self-Assembling Peptide Hydrogels2024-01-27T22:09:44-06:00https://digital.library.unt.edu/ark:/67531/metadc2257732/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc2257732/"><img alt="Mesenchymal Stem Cells Encapsulated and Aligned in Self-Assembling Peptide Hydrogels" title="Mesenchymal Stem Cells Encapsulated and Aligned in Self-Assembling Peptide Hydrogels" src="https://digital.library.unt.edu/ark:/67531/metadc2257732/small/"/></a></p><p>This study presents a viable strategy using fmoc-protected peptides hydrogels, to encapsulate and stretch mesenchymal stem cells (MSC). To explore the peptide hydrogel potential, a custom mechanical stretching device with polydimethylsiloxane (PDMS) chambers were used to stretch MSCs encapsulated in Fmoc hydrogels. We investigated the impact of fmoc- FF prepared in dimethyl sulfoxide (DMSO), 1,1,1,3,3,3-hexafluoro-2-propanol (HFP) and deionizied water in the self-assembly, and mechanical properties of the gels. The peptide hydrogel is formed through molecular self-assembly of peptide sequence into β-sheets that are connected with the π-π aromatic stacking of F-F groups. The hydrogels provided a stiff, hydrated gel with round nanofiber morphology representing an elastic modulus of 174-266 KPa. MSCs cultured on peptide hydrogels undergo viability, morphology, and alignment evaluations using MTT, live/dead, and phalloidin (F-actin) staining. The F-actins of 3D- cultured MSCs in Fmoc-FF/HFP, and Fmoc-FF/DMSO followed by mechanical stretching showed elongated morphology with defined microfilament fibers compared to the round and spherical F-actin shape of the control cells. Peptide gels with 5mM concentration preserved 100% viability of MSC. Results reveals the feasibility and conditions for successful cell encapsulation and alignment within peptide hydrogels. Encapsulation of MSC in peptide nanofiber followed by a stretching process present a promising tissue engineering platform. By enhancing our understanding of MSC-peptide hydrogel interactions, this research con- tributes to the development of biomaterials tailored for regenerative medicine.</p>Factors Affecting MeHg Contamination of Spiders and Insect-Mediated MeHg Flux from Human-Made Ponds2024-01-27T22:07:52-06:00https://digital.library.unt.edu/ark:/67531/metadc2257731/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc2257731/"><img alt="Factors Affecting MeHg Contamination of Spiders and Insect-Mediated MeHg Flux from Human-Made Ponds" title="Factors Affecting MeHg Contamination of Spiders and Insect-Mediated MeHg Flux from Human-Made Ponds" src="https://digital.library.unt.edu/ark:/67531/metadc2257731/small/"/></a></p><p>The present study focused on methylmercury (MeHg) in emergent aquatic insects and spiders from human-made ponds. This dissertation addresses two main topics: (1) factors affecting variation in spider MeHg concentrations around human-made ponds and (2) the magnitude of MeHg transported out of human-made ponds by emergent aquatic insects (insect-mediated MeHg flux). Spiders were specifically targeted in this study because they have been proposed as sentinels of MeHg contamination (organism whose tissue concentrations reflect the level of MeHg in the environment). Spider MeHg concentrations were related to spider diet, size, and proximity to waterbody, but affected individual spider taxa differently. In a second study, I found that only "large" spiders within a taxa had tissue concentrations positively related to prey MeHg concentrations. These results indicate that the relationship between spider and prey MeHg could be size-dependent and that "large" spiders within a taxa may better reflect ambient MeHg contamination. Finally, I tested a conceptual model hypothesizing insect-mediated MeHg flux from human-made ponds is controlled by pond permanence and fish presence. In agreement with the conceptual model, insect-mediated MeHg flux from ponds was suppressed by the presence of fish, likely due to fish predation on emergent insect larvae. I found the mean aggregate MeHg flux was approximately 6 times higher from ponds without fish than from ponds with fish. The suppression of insect flux by fish was stronger for large insect taxa than small insect taxa. Results of this study indicate that community structure can influence the cross-system transport of contaminants, like MeHg, from ponds to terrestrial food webs.</p>Cross-Pollinating Culturally Sustaining Pedagogies and Systemic Functional Linguistics in English as a Second Language (ESL) Classrooms2024-01-27T22:07:50-06:00https://digital.library.unt.edu/ark:/67531/metadc2257730/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc2257730/"><img alt="Cross-Pollinating Culturally Sustaining Pedagogies and Systemic Functional Linguistics in English as a Second Language (ESL) Classrooms" title="Cross-Pollinating Culturally Sustaining Pedagogies and Systemic Functional Linguistics in English as a Second Language (ESL) Classrooms" src="https://digital.library.unt.edu/ark:/67531/metadc2257730/small/"/></a></p><p>This exploratory case study research was conducted with a view to exploring how teachers teaching emergent bilingual students in ESL programs can enact the principles of culturally sustaining systematic functional linguistics (CS SFL), such as critical centering, historicizing, curricularizing, teaching and learning cycle (TLC), and semantic waving in their classrooms. Two middle school teachers participated in the study and used CS SFL principles to teach their emergent bilingual students. I gathered data for the study through non-participatory observations, semi-structured interviews, informal talks with the teachers, usually right after their classes, and artifacts from teachers and students. The thematic analysis of the data demonstrated that teachers could recognize their students' ways of knowing and being by (a) translanguaging between English and Spanish seamlessly in their classrooms; (b) centering their students' lifeways, prior knowledge, and lived experiences by making them the parts of their curricula; (c) using TLC for creating dialogic interactions between teachers and students and among students; (d) positioning their students through strength perspectives; and (e) using multimodal and multi-semiotic means of communication so that their students can understand their content area knowledge and express their ideas even if their English language is emerging. The teachers faced tensions about whether to reject or perpetuate the monolingual and monocultural ideologies expressed through English language requirements that emergent bilingual students should meet in order to succeed academically. Similarly, they reported that they had challenges in preparing students for high-stakes testing and offering their support for the students sent to in-school suspension (ISS).</p>Investigating the Molecular Framesworks of Phloem-Cap Fiber Development in Cotton (Gossypium hirsutum)2024-01-27T22:06:45-06:00https://digital.library.unt.edu/ark:/67531/metadc2257729/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc2257729/"><img alt="Investigating the Molecular Framesworks of Phloem-Cap Fiber Development in Cotton (Gossypium hirsutum)" title="Investigating the Molecular Framesworks of Phloem-Cap Fiber Development in Cotton (Gossypium hirsutum)" src="https://digital.library.unt.edu/ark:/67531/metadc2257729/small/"/></a></p><p>The current study focuses on the vascular cambium and the reiterative formation of phloem fiber bundles in cotton stems. The role of the TDIF-PXY-WOX pathway was examined in regulating cambial activity and the differentiation of phloem fibers. A study was conducted to identify and characterize the cotton WOX family genes, focusing on WOX4 and WOX14, aiming to identify and analyze their phylogenetic relationships, tissue-specific expression profiles, functional roles, and metabolic consequences. Through a sequence analysis of the Gossypium hirsutum genome, 42 cotton loci were identified as WOX family members. GhWOX4 exhibited a close homology to 7 loci, while GhWOX14 displayed homology with 8 loci. Tissue-specific expression analysis revealed prominent expression patterns of GhWOX4 and GhWOX14 in cotton internodes and roots, suggesting their involvement in vascular tissue development. Functional studies utilizing VIGS (virus-induced gene silencing) demonstrated that the knockdown of GhWOX4 and GhWOX14 resulted in a significant reduction in stem diameter and bast fiber production. This result suggests that secondary phloem fiber development is regulated by GhWOX4 and GhWOX14 genes in cotton. Additionally, the metabolic profiling of VIGS plants revealed significant alterations in amino acids, organic acids, and sugars, with implications for primary metabolic pathways. These findings suggest that GhWOX4 and GhWOX14 play pivotal roles in cotton plant development, including vascular tissue growth and phloem fiber production, and metabolic regulation.</p>Exploring the Relationship between Mental Health and Substance Use, Stable Housing, and Completion of the RISE Court Program2024-01-27T22:06:43-06:00https://digital.library.unt.edu/ark:/67531/metadc2257728/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc2257728/"><img alt="Exploring the Relationship between Mental Health and Substance Use, Stable Housing, and Completion of the RISE Court Program" title="Exploring the Relationship between Mental Health and Substance Use, Stable Housing, and Completion of the RISE Court Program" src="https://digital.library.unt.edu/ark:/67531/metadc2257728/small/"/></a></p><p>This thesis analyzes participants of the RISE Court program, a specialized court in Tarrant County, Texas, focusing on women involved in prostitution. The study investigates the intricate relationship between mental health, stable housing, substance abuse, and successful completion of the court program. Through a comprehensive analysis of participant data, the findings reveal insights into the intersection of mental health and the outcomes of participants in the RISE Court program. Contrary to the initial hypotheses, this study presents compelling evidence that mental health issues do not significantly hinder participants from completing the court program nor acquiring stable housing during their participation. However, the data strongly supports the hypothesis that participants with mental health problems are more likely to engage in substance use during the program. Notably, the study found that a substantial portion (71%) of the sample had documented mental health diagnoses, highlighting the pervasive nature of mental health challenges within this demographic. This research represents a considerable stride towards comprehending the complexities surrounding the criminal justice system's interventions for individuals engaged in prostitution, shedding light on the role of mental health in shaping their experiences within the RISE Court program. The findings have implications for the development of more effective, holistic strategies for rehabilitation and reintegration within specialized courts targeting this vulnerable population.</p>Analyzing the Joint Effects of Network and Community Attributes on Network Performance: Evidence from Local Continuum of Care Homeless Service Networks2024-01-27T22:06:11-06:00https://digital.library.unt.edu/ark:/67531/metadc2257727/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc2257727/"><img alt="Analyzing the Joint Effects of Network and Community Attributes on Network Performance: Evidence from Local Continuum of Care Homeless Service Networks" title="Analyzing the Joint Effects of Network and Community Attributes on Network Performance: Evidence from Local Continuum of Care Homeless Service Networks" src="https://digital.library.unt.edu/ark:/67531/metadc2257727/small/"/></a></p><p>This dissertation examines the factors and combinations of factors that affect the performance of continuum of care homeless service networks, applying the configurational approach of contingency theory to data sets drawn from federal sources. The study accepts the two key assumptions from the theory: (1) that there are multiple paths to high performance and (2) key conditions have a joint influence on network performance. The data analysis in this study has two parts. The first employs OLS regression to examine the causal relationship between independent variables and the performance of permanent supportive housing (PSH) programs. This study also applies fuzzy set qualitative comparative analysis (fsQCA) to identify multiple combinations of factors that influence the performance of PSH programs. The results identify key factors and multiple combinations of factors that lead to high and low network performance. Federal CoC funding emerges as a core condition for high and low performance, but all relevant conditions can be critical factors depending on how they interact with other relevant conditions. This analysis helps expand the utility of existing contingency theory by using it to explain the dynamic interactions between factors in the context of public service networks. Ultimately, this dissertation confirms that fsQCA can be a useful method for evaluating the performance of public service networks and helping them provide more services more effectively.</p>"Creature from the Unconscious"2024-01-27T22:03:41-06:00https://digital.library.unt.edu/ark:/67531/metadc2257726/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc2257726/"><img alt=""Creature from the Unconscious"" title=""Creature from the Unconscious"" src="https://digital.library.unt.edu/ark:/67531/metadc2257726/small/"/></a></p><p>Creature from the Unconscious is a reflexive genre hybrid film that follows the process of the director's journey of navigating the process of self-acceptance and self-love in the wake of trauma.</p>The Impact of Kindergarten Classroom Assignment on Classroom Teachers and Student Achievement2024-01-27T22:03:30-06:00https://digital.library.unt.edu/ark:/67531/metadc2257725/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc2257725/"><img alt="The Impact of Kindergarten Classroom Assignment on Classroom Teachers and Student Achievement" title="The Impact of Kindergarten Classroom Assignment on Classroom Teachers and Student Achievement" src="https://digital.library.unt.edu/ark:/67531/metadc2257725/small/"/></a></p><p>To determine the impact of an administrator's decision on student placement in kindergarten classrooms, teachers were asked to share their perceptions on how that decision impacted their ability to deliver instruction and follow the district scope and sequence, as well as how that decision impacts student academic achievement and social and emotional development. This qualitative study was designed to gather data from kindergarten teachers using focus group interviews and individual interviews of campus principals from two campuses within the same district. The following two ways in which kindergarten classrooms were created were explored: (a) by random assignment or (b) knowledge of students' academic and behavioral performance based on information relevant to their Pre-K experience. Campus principal participants reported that they each chose their method to provide equity in the classrooms and fairness amongst their teachers. Teacher participants reported that overall, they preferred to have as much information about incoming students as possible and to be a part of the process of placing students into classrooms for the following year. By examining these teachers' perspectives, the findings from this study may positively influence policy and practice for campus administrators as they decide how they will place students in kindergarten classrooms. Continued qualitative examination of student achievement could help determine if one method of placement positively impacts student achievement. Data collected from a larger sample within the district or expanded to compare between districts could help campus administrators make positive classroom placements for kindergarten students. Also, a quantitative study using a survey might provide a more expansive view of the impact of administrators' process of assigning kindergarten students to classrooms.</p>Acenaphthene and 1,10-Phenanthroline-Fused Βeta-Functionalized Porphyrins2024-01-27T22:02:14-06:00https://digital.library.unt.edu/ark:/67531/metadc2257724/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc2257724/"><img alt="Acenaphthene and 1,10-Phenanthroline-Fused Βeta-Functionalized Porphyrins" title="Acenaphthene and 1,10-Phenanthroline-Fused Βeta-Functionalized Porphyrins" src="https://digital.library.unt.edu/ark:/67531/metadc2257724/small/"/></a></p><p>A series of acene-fused porphyrins and 1,10-phenanthroline-fused porphyrins were synthesized and characterized via NMR spectroscopy and mass spectrometry. The acene-fused porphyrins exhibit unique optoelectronic properties, most notably they exhibit highly red-shifted absorption bands. The 1,10-phenanthroline-fused porphyrins are of interest for their ability to bond to as variety of metals to form chelation complexes.</p>Degradation Mechanisms and Dynamics of Silicon Telluride: A Guide to the Effective Fabrication and Characterization of Silicon Telluride-Based Devices2024-01-27T22:02:04-06:00https://digital.library.unt.edu/ark:/67531/metadc2257723/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc2257723/"><img alt="Degradation Mechanisms and Dynamics of Silicon Telluride: A Guide to the Effective Fabrication and Characterization of Silicon Telluride-Based Devices" title="Degradation Mechanisms and Dynamics of Silicon Telluride: A Guide to the Effective Fabrication and Characterization of Silicon Telluride-Based Devices" src="https://digital.library.unt.edu/ark:/67531/metadc2257723/small/"/></a></p><p>Silicon telluride (Si2Te3) and many other tellurium containing compounds show emergent Raman peaks located at ~120 cm-1 and ~140 cm-1 as they age. The origin of these two emergent peaks is controversial in the literature and has been attributed to myriad causes such as the intrinsic Raman modes of the telluride materials, surface oxidation, defects, double resonances, and tellurium precipitates. The controversial nature of these peaks has led to the misidentification of highly degraded materials as pristine and to the misinterpretation of changes in Raman spectra. For the first time, quality thin film and bulk crystals of Si2Te3 are grown using a chemical vapor deposition (CVD) process. We then present a comprehensive and multimodal study of various Si2Te3 samples and find that the two emergent Raman peaks originate from tellurium nano-crystallites formed in the degraded surface layers of Si2Te3. The formation of the tellurium nano-crystallites are shown to be a result of a hydrolysis process in which Si2Te3 reacts with atmospheric water vapor. The challenges involved in the fabrication of Si2Te3 based devices are also discussed and ways in which degradation can be either prevented or reversed are demonstrated. Finally, we present preliminary data which shows promising low voltage switching behavior in Si2Te3 memory devices.</p>Glucose-Induced Developmental Delay is Modulated by Insulin Signaling and Exacerbated in Subsequent Glucose-Fed Generations in Caenorhabditis elegans2024-01-27T22:00:02-06:00https://digital.library.unt.edu/ark:/67531/metadc2257722/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc2257722/"><img alt="Glucose-Induced Developmental Delay is Modulated by Insulin Signaling and Exacerbated in Subsequent Glucose-Fed Generations in Caenorhabditis elegans" title="Glucose-Induced Developmental Delay is Modulated by Insulin Signaling and Exacerbated in Subsequent Glucose-Fed Generations in Caenorhabditis elegans" src="https://digital.library.unt.edu/ark:/67531/metadc2257722/small/"/></a></p><p>In this study, we have used genetic, cell biological and transcriptomic methods in the nematode C. elegans as a model to examine the impact of glucose supplementation during development. We show that a glucose-supplemented diet slows the rate of developmental progression (termed "glucose-induced developmental delay" or GIDD) and induces the mitochondrial unfolded protein response (UPRmt) in wild-type animals. Mutation in the insulin receptor daf-2 confers resistance to GIDD and UPRmt in a daf-16-dependent manner. We hypothesized that daf-2(e1370) animals alter their metabolism to manage excess glucose. To test this, we used RNA-sequencing which revealed that the transcriptomic profiles of glucose-supplemented wildtype and daf-2(e1370) animals are distinct. From this, we identified a set of 27 genes which are both exclusively upregulated in daf-2(e1370) animals fed a glucose-supplemented diet and regulated by daf-16, including a fatty acid desaturase (fat-5), and two insulin-like peptides (ins-16 and ins-35). Mutation of any of these genes suppresses the resistance of daf-2(e1370) to GIDD. Additionally, double mutation of ins-16 and ins-35 in a daf-2(e1370) background results in an increase in constitutive dauer formation which is suppressed by glucose supplementation. Further investigation of the insulin-like peptides revealed that ins-16 mutation in a wild-type background results in upregulation of ins-35 and DAF-16 nuclear translocation regardless of diet; however, unlike daf-2(e1370), this translocation is not associated with resistance to GIDD. Taken together, these data suggest that glucose-supplemented daf-2(e1370) animals maintain developmental trajectory in part through upregulation of specific insulin-like peptide genes and fatty acid desaturation and contribute to a deeper understanding of the mechanisms underlying the resistance of daf-2(e1370) animals to GIDD. We also showed another fascinating aspect of GIDD: it becomes more pronounced in subsequent generations exposed to a glucose-supplemented diet, suggesting that the parental glucose diet has an impact on the developmental progression of their offspring.</p>Returning to Our Roots: An Anthropological Evaluation of the Farm to Keiki Program2024-01-27T21:59:55-06:00https://digital.library.unt.edu/ark:/67531/metadc2257721/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc2257721/"><img alt="Returning to Our Roots: An Anthropological Evaluation of the Farm to Keiki Program" title="Returning to Our Roots: An Anthropological Evaluation of the Farm to Keiki Program" src="https://digital.library.unt.edu/ark:/67531/metadc2257721/small/"/></a></p><p>Farm to school programs are becoming a popular intervention to address childhood obesity. The hope is to prevent later chronic illnesses such as diabetes and cardiovascular disease that can result from eating high-fat/high-calorie diets that are low in consumption of fresh fruits and vegetables. This study explores the impacts of one such program, Farm to Keiki, on students, their families, and teachers at two Native Hawaiian preschools on the island of Kauaʽi, Hawaiʽi. This program combined lessons about plants and nutrition with gardening at school and tastetesting in the classroom. Rooted in critical medical anthropology, this study utilized a combination of quantitative and qualitative methods to understand these impacts, as well as the historical and cultural contexts that have contributed to dietary changes among Native Hawaiians. Through in-depth interviews and focus groups, families and teachers described how the program encouraged the children to try new foods and eat more produce, and how the children demonstrated new knowledge about plants and healthy eating. Participants also spoke of ways in which their own knowledge and eating habits changed, and families reported carrying over many of the program's activities at home by gardening and preparing meals together. Additionally, participants offered valuable feedback on ways the program could be improved. This study, which appears to be the first of its kind to involve a Native Hawaiian farm-toschool program, demonstrates that an anthropological approach can provide critical depth and understanding of how programs like Farm to Keiki affect students and the people close to them.</p>Synthesis, Characterization, Standardization, and Validation of Luminescence Optical Chemosensors for the Detection of Carbon Dioxide, Aluminum Ions, and Silver Ions for Real-Life Applications2024-01-27T21:58:36-06:00https://digital.library.unt.edu/ark:/67531/metadc2257720/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc2257720/"><img alt="Synthesis, Characterization, Standardization, and Validation of Luminescence Optical Chemosensors for the Detection of Carbon Dioxide, Aluminum Ions, and Silver Ions for Real-Life Applications" title="Synthesis, Characterization, Standardization, and Validation of Luminescence Optical Chemosensors for the Detection of Carbon Dioxide, Aluminum Ions, and Silver Ions for Real-Life Applications" src="https://digital.library.unt.edu/ark:/67531/metadc2257720/small/"/></a></p><p>The presented dissertation encompasses three distinct investigations into novel complexes with diverse applications. Firstly, a Europium-based complex, K[Eu(hfa)4], exhibits remarkable potential for detecting dissolved CO2 in an ethylene glycol medium, offering a low limit of detection, rapid response times, and high signal-to-noise ratios. This complex demonstrates promise for quantifying CO2 concentrations and finds utility in sugar fermentation monitoring. Secondly, an innovative ratiometric optical sensor, Eu(tta)3([4,4'-(t-bu)2-2,2'-bpy)], showcases exceptional sensitivity and selectivity in detecting aluminum ions, making it suitable for environmental and biological applications. It exhibits reliable quantification in both methanol and aqueous samples, with remarkable accuracy validated by ICP-OES. Lastly, modifications to the Au3Pz3 complex synthesis enable the development of a silver ion sensor, paving the way for detecting silver ion leaching in real-life scenarios, such as silver nanoparticle-embedded bandages. The research extends to the synthesis of silver nanoparticles using various methods and foresees expanded in vitro and in vivo studies. These investigations collectively offer insights into the development of advanced sensing technologies with significant implications for a wide range of practical applications.</p>The Saxophone Meets Chinese Culture: A Guide to Works for Saxophone by Composer Zou Xiangping2024-01-27T21:57:07-06:00https://digital.library.unt.edu/ark:/67531/metadc2257719/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc2257719/"><img alt="The Saxophone Meets Chinese Culture: A Guide to Works for Saxophone by Composer Zou Xiangping" title="The Saxophone Meets Chinese Culture: A Guide to Works for Saxophone by Composer Zou Xiangping" src="https://digital.library.unt.edu/ark:/67531/metadc2257719/small/"/></a></p><p>Zou Xiangping is one of the most significant Chinese composers who writes music for the saxophone. These works, however, are not well-known in the classical saxophone repertoire. The purpose of this dissertation is to help international saxophonists develop an enlightened understanding and ultimately, performance of two selected pieces by Chinese composer Zou Xiangping (邹向平) (b. 1951), Images of Yalong River for Alto Saxophone and Piano (雅砻江印:为中音萨克斯管和钢琴) and Song of Chuanjiang River Boatman for Saxophone Quartet (川江纤夫之歌: 为萨克斯管四重奏) (2022). The compositional background, the relevant introduction about Chinese culture, the manner in which the composer combined this with Western compositional techniques, and comprehensive performance advice of each piece are provided.</p>Using GIFs and Matrix Training to Teach Noun-Verb Tacts to Children with Autism2024-01-27T21:55:42-06:00https://digital.library.unt.edu/ark:/67531/metadc2257718/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc2257718/"><img alt="Using GIFs and Matrix Training to Teach Noun-Verb Tacts to Children with Autism" title="Using GIFs and Matrix Training to Teach Noun-Verb Tacts to Children with Autism" src="https://digital.library.unt.edu/ark:/67531/metadc2257718/small/"/></a></p><p>Verbal behavior is a critical repertoire for children with autism spectrum disorder to acquire. Tacts—verbal behavior evoked by nonverbal stimuli—are important for communicating about the world around oneself. Noun-verb tacts are part of a robust tact repertoire and may be addressed during applied behavior analytic intervention. When acquiring noun-verb tacts, it is important that the speaker learn to respond to many variations of stimuli like novel combinations of learned nouns and verbs, which is called recombinative generalization. One strategy to teach multi-component targets, such as the noun-verb tact, and lead to recombinative generalization is matrix training. Matrix training is a framework utilized to arrange targets that can be combined in order to facilitate recombinative generalization by teaching a subset of combinations and then probing others. With three children with ASD, we used matrix training and evaluated the acquisition of trained and novel combinations of noun-verb tacts with GIFs as stimuli arranged in three matrices. We used a concurrent multiple probe design across sets, and our results indicated that all participants acquired trained noun-verb tact targets in the presence of the GIFs. The degree of recombinative generalization varied across participants, but each participant demonstrated recombinative generalization with some stimuli. We analyzed responding during generalization probes to identify possible sources of stimulus control. We discussed the errors that were emitted when testing for recombinative generalization and provided suggestions for future research on matrix training and recombinative generalization.</p>Transport of Proton, Hydrogen and Alpha Particles through Atomic Hydrogen Environment2024-01-27T21:54:53-06:00https://digital.library.unt.edu/ark:/67531/metadc2257717/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc2257717/"><img alt="Transport of Proton, Hydrogen and Alpha Particles through Atomic Hydrogen Environment" title="Transport of Proton, Hydrogen and Alpha Particles through Atomic Hydrogen Environment" src="https://digital.library.unt.edu/ark:/67531/metadc2257717/small/"/></a></p><p>Using multiple theoretical methods, comprehensive calculations are performed to create a new and more comprehensive data set for elastic scattering and related transport cross sections for collisions of (H$^+$ + H), (H + H) and (He$^{2+}$ + H) in the center-of-mass energy frame. In proton-atomic hydrogen collisions, we have significantly updated and extended previous work of elastic scattering, charge transfer and related transport integral and differential cross sections in the center-of-mass energy range $10^{-4} - 10^4$ eV where the multi-channel molecular orbital approach (MO3) is used. For atomic hydrogen-hydrogen collisions, similar updates have been made of elastic scattering and spin exchange differential and integral cross sections, also for the H + H collision the ionization and negative ion formation cross sections are provided in energy range (1-20 KeV) by use of the 'hidden crossing' theoretical framework. For collisions of alpha particles with atomic hydrogen we have computed the elastic scattering cross section in the center-of-mass energy range $10^{-4} - 10^8$ eV. In this case, at the lowest energies where elastic scattering greatly dominates other reaction channels, a single-channel quasi-molecular-orbital approach (MO1) is used. With the opening of inelastic channels at higher energies the multi-channel atomic-orbital, close-coupling method is applied, and at the highest energies considered perturbation theory (the Born approximation) is used. The results are compared with other data available in literature.</p>Teacher Perceptions of Innovative Learning Environments: Implications for Leaders2024-01-27T21:53:33-06:00https://digital.library.unt.edu/ark:/67531/metadc2257716/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc2257716/"><img alt="Teacher Perceptions of Innovative Learning Environments: Implications for Leaders" title="Teacher Perceptions of Innovative Learning Environments: Implications for Leaders" src="https://digital.library.unt.edu/ark:/67531/metadc2257716/small/"/></a></p><p>Innovative Learning Environments are increasingly built and implemented in schools, but are not necessarily being used according to designers' intentions. The goal of this study was to examine teacher perceptions of the innovative learning spaces they were charged with using and to determine if they were being used effectively and as designed. The research was guided by three basic questions: what were the teachers' perceptions of these spaces, was the teacher pedagogy need to change to accommodate the space, and did the teacher feel support by campus leadership. The fourth research question centered around the goals and vision of the design team that created the innovative learning space. The crux of the issue was that the districts vision for the space came to fruition once the teachers were in the actual space with the students. This qualitative study interviewed seven teachers in the educational setting and separately interviewed the design team. The results indicated that some of the teachers were unaware of the definition of an innovative space and believed that they were utilizing the space in ways that met the designs of the campus leadership. Furthermore, teachers felt the new designs caused a classroom management issue as well as safety and security concerns. The design team felt that teachers needed more training on how to use the innovative spaces and that they were not being used as intended. To inform future school and district policies as well as educational leadership practices, more work is needed around what types of training might be more effective in helping teachers make a pedagogical change if assigned to an innovative learning environment.</p>Predictors of Academic Success in an Early College Entrance Program2024-01-27T21:52:52-06:00https://digital.library.unt.edu/ark:/67531/metadc2257715/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc2257715/"><img alt="Predictors of Academic Success in an Early College Entrance Program" title="Predictors of Academic Success in an Early College Entrance Program" src="https://digital.library.unt.edu/ark:/67531/metadc2257715/small/"/></a></p><p>Early college entrance programs have existed in the United States since the 1950s, but in-depth research on academic success in these programs is lacking. Every year, early college entrance programs utilize a variety of data-gathering and candidate-screening techniques to select hundreds of students for admission into these accelerated programs. However, only a smattering of research articles has discussed the factors that predict academic success in these programs. This exploratory study investigated commonly-relied-upon admissions data points—such as high school GPA and ACT scores—and demographic information—such as sex, ethnicity, and locality—to see if any of these factors predicted academic success: namely, graduation and early college entrance program GPA. Secondary data from nearly 800 students admitted over an 11-year period to a state-supported, residential early college entrance program located at a large Southern university in the United States were utilized for this study. Logistic regression failed to yield a model that could accurately predict whether or not a student would graduate from the program. Multiple regression models showed that high school GPA and ACT scores were predictive of performance, and that factors like locality and ethnicity can have predictive power as well. However, the low variance in performance explained by the variables included in this study demonstrates that high school GPA, standardized test scores, locality, sex, and ethnicity can only tell us so much about a student's likelihood of success in an early college entrance program.</p>The Effects of Specific and Disguised Mands on Staff's Reinforcer Delivery2024-01-27T21:52:03-06:00https://digital.library.unt.edu/ark:/67531/metadc2257714/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc2257714/"><img alt="The Effects of Specific and Disguised Mands on Staff's Reinforcer Delivery" title="The Effects of Specific and Disguised Mands on Staff's Reinforcer Delivery" src="https://digital.library.unt.edu/ark:/67531/metadc2257714/small/"/></a></p><p>Residential facilities for adults with developmental disabilities offer essential accommodations and support services, with fostering communication for residents as an important aspect of care. Despite the importance of communication, previous research has identified concerns about staff performance (SP) in facilitating positive social interactions, such as engaging in consequent-mediating behavior for residents' mands. Previous research has primarily focused on improving SP through skills-based training. Yet, Skinner's theory of verbal behavior emphasizes the social and reciprocal nature of mands. Skinner suggests that the listener's behavior, engaging in consequence-mediating behavior, must be conditioned by the verbal community. However, empirical investigations into the reinforcing practices of staff in residential facilities, such as the shaping and sustaining of different types of resident mands, is limited. The current investigation sought to address this gap in research by evaluating if distinct mand topographies, disguised or specific mands, influenced the likelihood of staff engaging in consequence-mediated behavior across three staff-resident dyads. Results suggest a low probability of staff responding to, or reinforcing, mands, thus limiting conclusions on the effects of mand topographies on staff performance. Future directions and considerations regarding resident-staff interactions are discussed.</p>Development and Characterization of Compliant Bioelectronic Devices for Gastrointestinal Stimulation2024-01-27T21:51:00-06:00https://digital.library.unt.edu/ark:/67531/metadc2257713/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc2257713/"><img alt="Development and Characterization of Compliant Bioelectronic Devices for Gastrointestinal Stimulation" title="Development and Characterization of Compliant Bioelectronic Devices for Gastrointestinal Stimulation" src="https://digital.library.unt.edu/ark:/67531/metadc2257713/small/"/></a></p><p>In this research, we aimed to develop thin-film devices on a polymer substrate and an alternative 3D-printed device with macroelectrodes for treating gastrointestinal (GI) conditions. First, the fabrication of thin-film devices was demonstrated on a softening thiol-ene/acrylate polymer utilizing titanium nitride (TiN) as electrode material. This was achieved by utilizing cleanroom fabrication processes such as photolithography, wet and dry etching. The functionality of the device was shown by performing electrochemical characterization tests, mainly cyclic voltammetry, electrochemical impedance spectroscopy, and voltage transient. We synthesized a novel thiol-ene/acrylate polymer based on 1,3,5-triallyl-1,3,5-triazine-2,4,6(1H,3H,5H)-trione (TATATO), trimethylolpropanetris (3-mercaptopropionate) (TMTMP), and polyethylene glycol diacrylate (PEGDA). We show that this stretchable shape memory polymer substrate is well suited for cleanroom processes. Finally, for the high throughput of the wearable devices with electrodes size 10 mm in diameter, we implemented single electrode fabrication using printed circuit boards (PCBs) and depositing gold (Au) and TiN on the plated side of PCBs utilizing the sputtering tool. This step was followed by the assembly of those single electrodes on the flexible 3D printed device. We showed that the TiN electrode material performed better in terms of charge storage capacity and charge injection capacity than the widely used stainless steel electrode material for wearables.</p>Directing Transition Metal Catalysis of Second and Third Row Metals through Ligand Design2024-01-27T21:50:25-06:00https://digital.library.unt.edu/ark:/67531/metadc2257712/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc2257712/"><img alt="Directing Transition Metal Catalysis of Second and Third Row Metals through Ligand Design" title="Directing Transition Metal Catalysis of Second and Third Row Metals through Ligand Design" src="https://digital.library.unt.edu/ark:/67531/metadc2257712/small/"/></a></p><p>Ligand design is important due to a ligand's ability to tune properties of the transition metals, such as catalytic activity and selectivity. Gold(I) catalysts can be directly impacted by ligands electronically as well as with steric bulk when undergoing enantioselective and regioselective reactions. In the dissertation, a series of gold(I) acyclic diaminocarbenes were synthesized and used to explore the 1,6 enyne cyclization/hydroarylation. The use of metal templated synthesis of the gold(I) acyclic diaminocarbenes allowed for the gradual increase in steric bulk of the catalysts. In the end, it was shown that electronics play the major role in the regioselectivity for the 1,6 enyne cyclization/hydroarylation but localized steric bulk can control the catalytic reaction if placed strategically. Cross-coupling reactions used to form carbon-carbon or carbon-heteroatom bonds are important in the production of pharmaceutical chemicals on a large scale. Iron, an extremely cheap and earth abundant first row transition metal, has had some success in cross-coupling reactions. Iron does not go through the same catalytic cycle for cross-coupling as most transition metals, the most common of which is palladium. In the dissertation, a ligand was developed to induce Iron to undergo the same cycle as palladium. In addition, the same ligand was placed on palladium(II) and reduced to try to form and isolate a catalytically active palladium(0) complex.</p>Sonorous Andean Landscapes: A Performance Guide for Guevara Ochoa's "Yaraví, Danza y Huayno" (n.d) and Vivanco's "Fantasía Andina" (c. 1988)2024-01-27T21:49:06-06:00https://digital.library.unt.edu/ark:/67531/metadc2257711/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc2257711/"><img alt="Sonorous Andean Landscapes: A Performance Guide for Guevara Ochoa's "Yaraví, Danza y Huayno" (n.d) and Vivanco's "Fantasía Andina" (c. 1988)" title="Sonorous Andean Landscapes: A Performance Guide for Guevara Ochoa's "Yaraví, Danza y Huayno" (n.d) and Vivanco's "Fantasía Andina" (c. 1988)" src="https://digital.library.unt.edu/ark:/67531/metadc2257711/small/"/></a></p><p>Peruvian composers Armando Guevara Ochoa (1926–2013) and César Vivanco (b. 1949) borrow and transplant musical elements from Andean folk tradition into their compositions for the modern classical flute. Guevara Ochoa's Yaraví, Danza y Huayno and Vivanco's Fantasía Andina are solo flute pieces rooted in Peruvian folklore traditions and Andean instrumental performance. The purpose of this dissertation is to provide flutists with technical and interpretative guidance in preparing these pieces. Yaraví, Danza y Huayno, a suite of three short dances, and Fantasía Andina, a free-meter piece in an improvisational style, incorporate elements that utilize the performance techniques of Andean instruments, with use of quotations from traditional Andean folk music. References to quenas (traditional vertical flutes), zampoñas (panpipes), pututos (ceremonial natural horns), charangos (Andean guitars) and Andean harps are integrated within the works and fused with themes borrowed from iconic pieces such as El cóndor pasa, and traditional harmonic, melodic and rhythmic structures of the huayno (fast festive dance) and yaraví (slow melancholic song). The techniques and traditions borrowed from Andean folk music are not notated in these scores due to the limitations of musical notation. Performers are expected to portray the Andean musical identity of the composers' intent. This dissertation assists performers unfamiliar with the traditions of Andean music to identify and understand the implicit Andean roots in both works and develop techniques to accurately represent sounds of Andean Peruvian traditions, with a deeper, culturally informed interpretation of this music.</p>FruitPAL: An IoT-Enabled Framework for Automatic Monitoring of Fruit Consumption in Smart Healthcare2024-01-27T21:46:08-06:00https://digital.library.unt.edu/ark:/67531/metadc2257710/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc2257710/"><img alt="FruitPAL: An IoT-Enabled Framework for Automatic Monitoring of Fruit Consumption in Smart Healthcare" title="FruitPAL: An IoT-Enabled Framework for Automatic Monitoring of Fruit Consumption in Smart Healthcare" src="https://digital.library.unt.edu/ark:/67531/metadc2257710/small/"/></a></p><p>This research proposes FruitPAL and FruitPAL 2.0. They are full automatic devices that can detect fruit consumption to reduce the risk of disease. Allergies to fruits can seriously impair the immune system. A novel device (FruitPAL) detecting fruit that can cause allergies is proposed in this thesis. The device can detect fifteen types of fruit and alert the caregiver when an allergic reaction may have happened. The YOLOv8 model is employed to enhance accuracy and response time in detecting dangers. The notification will be transmitted to the mobile device through the cloud, as it is a commonly utilized medium. The proposed device can detect the fruit with an overall precision of 86%.
FruitPAL 2.0 is envisioned as a device that encourages people to consume fruit. Fruits contain a variety of essential nutrients that contribute to the general health of the human body. FruitPAL 2.0 is capable of analyzing the consumed fruit and then determining its nutritional value. FruitPAL 2.0 has been trained on YOLOv5 V6.0. FruitPAL 2.0 has an overall precision of 90% in detecting the fruit.
The purpose of this study is to encourage fruit consumption unless it causes illness. Even though fruit plays an important role in people's health, it might cause dangers. The proposed work can not only alert people to fruit that can cause allergies, but also it encourages people to consume fruit that is beneficial for their health.</p>The Impact of Leadership on School Culture and Teacher Retention2024-01-27T21:45:58-06:00https://digital.library.unt.edu/ark:/67531/metadc2257709/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc2257709/"><img alt="The Impact of Leadership on School Culture and Teacher Retention" title="The Impact of Leadership on School Culture and Teacher Retention" src="https://digital.library.unt.edu/ark:/67531/metadc2257709/small/"/></a></p><p>To determine the impact that school leaders have on school culture and teacher retention, a sequential explanatory mixed methods approach was used to study schools in a district feeder pattern in in a large, suburban district in Texas with a student population of approximately 25,000. In Phase 1, teachers at one elementary, one middle, and one high school were asked to complete a 26-question Likert scale survey about school culture. The last statement in the survey asked participants if they were willing to participate in a focus group about school culture and teacher retention. In Phase 2, focus group interviews were conducted with volunteer participants who took the survey and stated they would be interested in participating in a focus group. Three focus groups were held to divide the participants by grade level grouping taught: elementary, middle, and high school. Focus group participants stated that they believe school leaders play a vital role in creating the culture of the school and in teachers' desire to remain not only teaching at their school, but also remaining in the field of education. The survey data supported these findings. By examining teachers' perspectives, the findings of the study may positively inform and influence district hiring practices, develop leadership profiles and behaviors, and provide school leaders with ways to recruit and retain teachers. Further research could include a case study at one specific school or expanding the sample size and including more schools or studying a variety of districts to find additional ways to build school culture and retain teachers.</p>Kinetics and Thermochemistry of Halogen and Nitrogen Compounds2024-01-27T21:44:49-06:00https://digital.library.unt.edu/ark:/67531/metadc2257708/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc2257708/"><img alt="Kinetics and Thermochemistry of Halogen and Nitrogen Compounds" title="Kinetics and Thermochemistry of Halogen and Nitrogen Compounds" src="https://digital.library.unt.edu/ark:/67531/metadc2257708/small/"/></a></p><p>Halogen and nitrogen containing compounds play a key role in the atmospheric chemistry of the Earth. Through a mixed computational and experimental approach, the kinetics of these compounds with radicals common to the atmosphere have been explored. Using fundamental measurements such as the IR absorption cross-section, the rate constants of atmospheric reactions and the properties of product molecules have been derived. These results have been further extended to environmental applications such as the Global Warming Potential for a species. The present results can be used as a calibration for further experiments and as checks on computational predictions of environmental properties. Such modeling can aid in the development of future industrial reagents that are less hazardous to the atmosphere.</p>Surface Engineering of Materials for Beyond-Microelectronics2024-01-27T21:44:13-06:00https://digital.library.unt.edu/ark:/67531/metadc2257707/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc2257707/"><img alt="Surface Engineering of Materials for Beyond-Microelectronics" title="Surface Engineering of Materials for Beyond-Microelectronics" src="https://digital.library.unt.edu/ark:/67531/metadc2257707/small/"/></a></p><p>All oxide heterostructure Cr2O3/TiO2-x was deposited on Al2O3(0001) single crystal via MBE. The analysis of interfacial interactions involving two metal oxides resulting in magnetic properties gave insights for using such heterostructures as potential spintronic device materials. The corundum phase epitaxial growth of TiO2-x on Al2O3 was characterized using XPS, AES, EELS, and LEED. The data obtained gives evidence of presence of two-dimensional electron gas at titania surface due to oxygen vacancies formation after deposition. On titania, the deposition of chrome in UHV results in the formation of oxidized chromia overlayer by abstraction of oxygen from the TiO2-x underlayer further increasing the number of vacancies present. In industrial R&D project, dry etching of multiple optical device components was performed using a novel angled etch prototype tool. The first set of experiments involved plasma etching of SiC thin films optimized for target application. The best-known method (BKM) worked from 300mm full wafer to 200mm product. In second experimentation, a variety of gray-tone photoresist received from customers were etched using BKM. Customer received etch rate on each gray-tone material. The third experiments compared recipe R1 to test recipe R2 on the test vehicle VDC. R2 showed faster etch rate but lower process repeatability (RMSE%). With continuous improvement of the tool and the process, two tools are operating products every day, a third prototype tool is about to be in pilot production.</p>A Pedagogical Analysis of "Seven Chinese Folk Songs" by Wanghua Chu2024-01-27T21:42:42-06:00https://digital.library.unt.edu/ark:/67531/metadc2257706/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc2257706/"><img alt="A Pedagogical Analysis of "Seven Chinese Folk Songs" by Wanghua Chu" title="A Pedagogical Analysis of "Seven Chinese Folk Songs" by Wanghua Chu" src="https://digital.library.unt.edu/ark:/67531/metadc2257706/small/"/></a></p><p>Wanghua Chu (b. 1941) is an outstanding Chinese composer and pianist, who has written extensively for piano. This dissertation offers a pedagogical analysis of Seven Chinese Folk Songs (1999), one of his most famous and well-regarded piano solo works. The present study has two broad and related aims: to introduce Wanghua Chu's Seven Chinese folk songs to a broader community of pianists outside of China; and to provide a pedagogical analysis so that pianists of a late-intermediate level and higher can learn it effectively and teachers can teach it successfully. Chapter 2 provides an overview of Wanghua Chu's artistic career and major works, as well as the composition background of Seven Chinese Folk Songs. Chapter 3 introduces the seven original Chinese folk songs that are used in this work, both the actual songs and the song types. Chapter 4 provides an analysis of the musical form of each movement of Seven Chinese Folk Songs. Chapter 5 analyzes the technical difficulties of this work and provides specific practice methods to solve them. Seven Chinese Folk Songs exposes the pianist to the diversity and richness of Chinese folk songs and offers them a different kind of learning opportunity in which they not only broaden their horizons through learning Chinese folk songs and ethnic cultures but also improve their piano playing techniques, as well as enhance their musical expression and imagination abilities.</p>A Comprehensive Investigation of Photoinduced Electron Transfer and Charge Transfer Mechanisms in Push-Pull Donor-Acceptor Systems: Implications for Energy Harvesting Applications2024-01-27T21:42:11-06:00https://digital.library.unt.edu/ark:/67531/metadc2257705/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc2257705/"><img alt="A Comprehensive Investigation of Photoinduced Electron Transfer and Charge Transfer Mechanisms in Push-Pull Donor-Acceptor Systems: Implications for Energy Harvesting Applications" title="A Comprehensive Investigation of Photoinduced Electron Transfer and Charge Transfer Mechanisms in Push-Pull Donor-Acceptor Systems: Implications for Energy Harvesting Applications" src="https://digital.library.unt.edu/ark:/67531/metadc2257705/small/"/></a></p><p>Donor-acceptor systems exhibit distinctive attributes rendering them highly promising for the emulation of natural photosynthesis and the efficient capture of solar energy. This dissertation is primarily devoted to the investigation of these unique features within diverse donor-acceptor system typologies, encompassing categories such as closely covalently linked, push-pull, supramolecular, and multi-modular donor- acceptor conjugates. The research encompasses an examination of photosynthetic analogs involving compounds such as chelated azadipyromethene (AzaBODIPY), N,N-dimethylaminophenyl (NND), phenothiazine (PTZ), triphenylamine (TPA), phenothiazine sulfone (PTZSO2), tetracyanobutadiene (TCBD), and expanded tetracyanobutadiene (exTCBD). The strategic configuration of the donor (D), acceptor (A), and spacer elements within these constructs serves to promote intramolecular charge transfer (ICT), which are crucial for efficient charge and electron transfer. The employment of cutting-edge analytical techniques, such as ultrafast transient absorption spectroscopy, is integral to the study. Furthermore, a comprehensive suite of analytical methodologies including steady-state UV-visible absorption spectroscopy, fluorescence and phosphorescence spectroscopies, electrochemical techniques (including cyclic voltammetry and differential pulse voltammetry), spectroelectrochemistry, and density functional theory calculation (DFT), collectively contribute to the comprehensive characterization of push-pull donor-acceptor systems, with a particular emphasis on their potential as highly effective solar energy harvesting application.</p>The Effect of Developmental Hypoxia on Cardiac Physiology in Three Species: Alligator mississippiensis, Chelydra serpentina, and Danio rerio2024-01-27T21:40:16-06:00https://digital.library.unt.edu/ark:/67531/metadc2257704/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc2257704/"><img alt="The Effect of Developmental Hypoxia on Cardiac Physiology in Three Species: Alligator mississippiensis, Chelydra serpentina, and Danio rerio" title="The Effect of Developmental Hypoxia on Cardiac Physiology in Three Species: Alligator mississippiensis, Chelydra serpentina, and Danio rerio" src="https://digital.library.unt.edu/ark:/67531/metadc2257704/small/"/></a></p><p>In this dissertation, I explored the effects of developmental hypoxia on heart contractility in three separate species of ectotherms: the common snapping turtle (Chelydra serpentina), the American alligator (Alligator mississippiensis), and the zebrafish (Danio rerio). I began with the common snapping turtle and tested whether the utilization of the sarcoplasmic reticulum was altered in response to developmental hypoxia. In the next two chapters, developmental hypoxia of the American alligator was explored studying how the cardiac tissue was affected, specifically in physiological stressors, sarcoplasmic reticulum utilization and sensitivity to pharmacological increases in contractility. The last chapter explored how zebrafish heart contractility was altered in response to chronic hypoxia from egg to adult. Findings from these chapters suggest that while developmental hypoxia did alter cardiac contractility, it did not alter the response of the heart to physiological stressors such as increased heart rate or under hypoxia. Overall, these findings contribute to increasing the current understanding of how developmental hypoxia alters the cardiovascular system but with an emphasis on the cardiac tissue level.</p>