Magnetron Sputtering of Transition Metal Oxynitrides and Their Characterization with Auger Electron Spectroscopy and X-ray Photoelectron Spectroscopy (open access)

Magnetron Sputtering of Transition Metal Oxynitrides and Their Characterization with Auger Electron Spectroscopy and X-ray Photoelectron Spectroscopy

Transition metal oxynitrides are of growing interest for their use as electrocatalyst for nitrogen reduction reaction. The metals in the oxynitride used for catalytic process are stabilized in intermediate state for effective activation of nitrogen. Therefore, studying the interaction of metal oxynitrides films to ambient exposure is necessary. Here, sputter deposited vanadium oxynitride is compared to cobalt oxynitride using insitu Auger electron spectroscopy (AES), ex situ X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and scanning electron microscopy (SEM). After deposition in Ar/N2 environment, in situ AES spectra indicate that film is vanadium oxynitride despite oxygen is not the reactive gas. In contrast, in situ AES indicate film is pure cobalt nitride at the same base pressure and deposition condition (as vanadium). For ambient exposure, in situ AES indicate the incorporation of oxygen in the cobalt nitride film to form cobalt oxynitride. Ex situ XPS indicate both films get more oxidized but uniformly distributed as there is only slight difference in grazing and normal emission XPS. XRD and SEM also indicate how homogeneously distributed both films are. These finding confirms how important it is that transition metal centers are kept in intermediate oxidation state for the activation of nitrogen bond.
Date: May 2023
Creator: Adesope, Qasim Adewale
Object Type: Thesis or Dissertation
System: The UNT Digital Library
The Shape of Zauzou Noun Phrases: Predicting Reference Type, Classifiers, Demonstratives, Modifiers and Case Marking Using Syntax, Semantics, and Accessibility (open access)

The Shape of Zauzou Noun Phrases: Predicting Reference Type, Classifiers, Demonstratives, Modifiers and Case Marking Using Syntax, Semantics, and Accessibility

What explains the shape of Zauzou noun phrases? Zauzou (Trans-Himalayan, China) noun phrases exhibit considerable diversity in both the choice of the phrase's primary reference type, and the presence of classifiers, demonstratives, modifiers, and case marking. This investigation uses a large, previously existing Zauzou textual corpus. The corpus was annotated for variables hypothesized to predict the variation in noun phrase form. Syntactic variables investigated include word order, subordination, subordinate role, and a new variable called "loneliness." Participant semantic variables include thematic role, agency, and affectedness. Referential semantic variables include boundedness, number, and animacy. The information packaging variable investigated is accessibility. Statistical analysis of the corpus revealed that case marking was predicted using a variable called "loneliness." This is where a multivalent verb has only one argument that is explicitly referenced in the clause. Lonely noun phrases are more likely to be case marked. The role of loneliness in motivating case marking confirms that disambiguation can be an explanation for differential case marking. Animacy and accessibility are important predictors of noun phrase weight. Overall, high animacy and high accessibility correspond to reduced noun phrase weight. Agency and thematic role were also significant variables. The Zauzou data makes clear that speech act …
Date: May 2023
Creator: Hull, Benjamin
Object Type: Thesis or Dissertation
System: The UNT Digital Library
What School Leaders Need to Know: The Impact of Teacher Turnover on Student Achievement in Middle School Mathematics (open access)

What School Leaders Need to Know: The Impact of Teacher Turnover on Student Achievement in Middle School Mathematics

This study looked at the relationship between teacher turnover and student achievement, in addition to the relationship between specific student demographic characteristics and teacher turnover. Within this study, student demographic, staff demographic, and student achievement data from several middle schools within the studied district, as well as data from each of the school's comparison groups, as designated by the Texas Education Agency, was analyzed. The data used was from the 2018-2019, 2020-2021, and 2021-2022 school years. First, this study looked at specific student demographic characteristics and their relationship with teacher turnover, including race, mobility, and socioeconomic status. This analysis determined if there were specific variables that impacted the rate of turnover. Results determined that the most consistent relationship revealed in the data involves the total number of students on a campus. As the number of students increased, the turnover rate decreased. Additionally, there was a slight negative correlation between the number of African American students and rates of teacher turnover for two of the three years studied. The second part of the study determined if the campus turnover rate had any relationship with the student achievement scores. The student achievement data that was used was the overall campus math score …
Date: May 2023
Creator: Grindle, Colleen D.
Object Type: Thesis or Dissertation
System: The UNT Digital Library

Security Aspects of Users' Information Sharing on Social Media

This study aims to investigate college students' security awareness of using social media in sharing information. The two theories that have guided this study are the theory of planned behavior (TPB) and the technology acceptance model (TAM). Data was collected from both undergraduate and graduate students from the University of North Texas (UNT) in Denton. The total responses included 380 students from different majors with 291 valid responses for data analysis; The structural equation model (SEM) Lavaan package was used to find out the best fit of the model. A diagonally weighted least squares (DWLS) was used to model the variables as ordinal in this study's analysis as ordinal data made the model fit substantially. The study found that 6 factors: attitude (AB), subjective norm (SN), perceived behavior control (PBC), perceived usefulness (PU), perceived risks (PR), and security awareness (SA) influenced behavior intention (BI). Also, I found that AB was influenced by PR and SA, as well as SN influenced by SA. Self-efficacy (SE) influenced PBC. On the other hand, the study found that controllability (C) did not influence PBC; perhaps, an individual's skills do not interact with social media security settings. Perceived ease of use (PEOU) did not influence …
Date: May 2023
Creator: Alharbi, Mohannad Abdulltef
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Making Meetings More Meaningful: An Exploration of Meeting Science in Libraries (open access)

Making Meetings More Meaningful: An Exploration of Meeting Science in Libraries

This article adds to the growing body of research in meeting science, explored from a library perspective. The authors investigate the predictors of success for productive meetings, librarian perceptions of effective meeting leadership, and best practices for meeting leadership.
Date: May 12, 2021
Creator: Leuzinger, Julie & Brannon, Sian
Object Type: Article
System: The UNT Digital Library
The Use of Collabrify Roadmaps Digital Curricula for Face-to-Face and Remote Instruction (open access)

The Use of Collabrify Roadmaps Digital Curricula for Face-to-Face and Remote Instruction

This qualitative multiple case study attempts to capture and document the lived experiences of a group of elementary educators surrounding the COVID-19 emergency school closures of the 2019-2020 school year. The purpose of this study is to capture the observations and reactions of teachers after their experience using the Collabrify Roadmaps digital curriculum platform in both remote and face-to-face instructional settings to document and analyze the perceived benefits and challenges in using such a digital curriculum. By utilizing a semi-structured interview process, this study documents experiences and advice from educators in the field regarding the use of digital curricula. The findings from this study offer insight regarding the tools and features teachers want and need in digital curricula.
Date: May 2023
Creator: Mahaffey, Frances Dendy
Object Type: Thesis or Dissertation
System: The UNT Digital Library

Expansion of Pianism through a Reinterpretation of Bartók's Dance Suite for Solo Piano (1925)

This project offers a comprehensive performance guide to Bartók's Dance Suite for solo piano based on a renewed interpretation of the piece. The Dance Suite (Táncszvit/Tanz Suite) is a unique work in Bartók's oeuvre, presented by the composer in two versions: one for orchestra (1923) and one for solo piano (1925). There has been little research done on this piece to enhance its popularity even though it may be a piece that illuminates one of Bartók's compositional philosophies: the unity of all cultures and folk song. Pianists must interpret this piece not only through the eyes of a soloist, but also as a musician who makes careful decisions—as if one were undertaking the making of a piano reduction of an orchestral score oneself. The methods presented intend to help pianists acquire and maintain a curious and flexible mind where freedom of interpretation is concerned, and hone inquisitive minds to overcome challenges when holding the reins of an orchestra across the eighty-eight keys of the piano towards limitless expansion and development of pianism and musicianship.
Date: May 2023
Creator: Lee, Jenny JungYeon
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Professional Learning Communities and the Supportive Conditions for Improved Teacher Instructional Practices (open access)

Professional Learning Communities and the Supportive Conditions for Improved Teacher Instructional Practices

The purpose of the study was to examine and evaluate the extent to which the supportive conditions (collaboration, teacher efficacy, shared leadership, and trust) were present in the district's current professional learning communities (PLCs) model, and whether teachers perceived the supportive conditions to be related to improving their instructional practices. This mixed-methods study used Pearson correlation coefficient, multiple regression, and focus group interviews to concurrently triangulate data to answer the research questions. The sample from this study was identified from 600 middle school teachers. Survey participants included 139 teachers and each of the four focus group interviews contained 6 teachers for a total of 24 teachers. Of the four supporting conditions analyzed, trust generated the highest mean (M = 3.41). Results from this study indicate that the supportive conditions for PLCs have a strong correlation (0.10) with the studied district's current PLC model and each specific supporting condition elicits a targeted aspect of professional learning that has a significant impact on teacher instructional practices. Recommendations for future studies include the expansion of this study to include elementary and high school participants and to extend this study to a larger scope of interested districts seeking to improve their PLC structures for …
Date: May 2023
Creator: Parham, Charlene Marie
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Suppression of Higher Acoustic Harmonics by Application of Solid-Solid Periodic Layered Structure in Nonlinear Ultrasonics Nondestructive Evaluation Field (open access)

Suppression of Higher Acoustic Harmonics by Application of Solid-Solid Periodic Layered Structure in Nonlinear Ultrasonics Nondestructive Evaluation Field

Nondestructive testing (NDT) using ultrasound band 1-5 MHz, has been widely used for the early-stage detection of structural failure; however, it fails to detectf material degradation, fatigue, and microcracks. NDT with nonlinear ultrasound (NLU) can detect a microscopic discontinuity or imperfection that may be a source of the second harmonic in the reflected signal. In this research, we focus on creating a metamaterial band filter that filters out nonlinearities induced by the instrument itself. A 1D elastic superlattice (SL) acoustic filter is designed with a bandgap in its frequency spectrum that covers the frequency range of second harmonic. The SL is made of periodically alternating Cu and Sn-Pb solder layers. We conducted analytical and numerical calculations to obtain the appropriate thickness of each layer. The metamaterial in this study has the pass band for the fundamental frequency of 5 MHz and the first stop band centered near the frequency of 10 MHz; 5 MHz was chosen because the second harmonic at 10 MHz can detect 200μm micro-scale damage. Experiments with aluminum as the reference specimen and with SL filter were conducted. A function-generator generates 3 pulses sine signal, within the frequency range from 2.5 MHz to 20MHz. Spectral analysis of …
Date: May 2023
Creator: Kang, Jinho
Object Type: Thesis or Dissertation
System: The UNT Digital Library

The Lived Experiences of Puerto Rican Mental Health Professionals Who Provided Postdisaster Counseling Services to Children

This photovoice study explored the lived experiences of nine Puerto Rican mental health professionals who provided postdisaster counseling services to children. Due to the complex and multilayered experiences of Puerto Rican mental health professionals, this study used intersectionality as the theoretical lens to facilitate thematic analysis of the data. Results from coresearchers' narratives and photographs generated seven major themes: (a) la politiquería of disasters; (b) the impact of compounding disasters; (c) Puerto Rico se levanta: strategies for collective healing; (d) impact of disasters on children; (e) experiences with clients; (f) awareness, action, change; and (g) supporting, connecting, and transforming. The results and discussion provide awareness into the experiences of Puerto Rican clinicians who formed part of disaster response efforts in their own community. Clinical, educational, and research implications are drawn from coresearchers' narratives and insight.
Date: May 2023
Creator: Rodríguez Delgado, Mónica
Object Type: Thesis or Dissertation
System: The UNT Digital Library

Implementing the Multicultural and Social Justice Counseling Competencies with Black, Indigenous, and Womxn of Color

The purpose of this descriptive multiple case study was to explore how counselors implement multicultural and social justice counseling competencies (MSJCC) when providing therapy to Black, Indigenous, and Womxn of Color. This study was informed by critical theory and intersectionality theory to capture the complex dynamics of identity and power through semi-structured interviewing, observations of archived counseling sessions, review of archived client case records, and administration of the Multicultural Awareness, Knowledge, and Skills Survey–Counselor Edition–Revised (MAKSS-CE-R), and the Social Justice Scale (SJS). The six doctoral student co-researchers provided rich portrayals of their experiences implementing the MSJCC, the role of identity, and the impact of power relations. Data revealed one overarching theme (the omnipresence of cultural humility), five themes (learning is a process, it starts with me: the catalyst of self-awareness, this is my identity, understanding clients in context: attending to power and intersectionality, and social justice is awareness: advocacy is intentional and active), and eight corresponding subthemes. Co-researchers provided insight into their experiences of barriers, oppression, resilience, and advocacy. Implications and conclusions from this research provide recommendations for mental health counselors, education programs, and research.
Date: May 2023
Creator: Jarrett, Jodi Ann N.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
The Effects of Generational Stereotypes and Attribute Affirmation on the Collection of Audit Evidence (open access)

The Effects of Generational Stereotypes and Attribute Affirmation on the Collection of Audit Evidence

As the workplace has evolved over the past few years, several studies have documented perceived differences in personalities, values, and preferences between generations in the workplace, including in public accounting. In this study, I examine whether exposure to a negative preconceived belief about a staff auditor's generation (generational stereotype) influences the affective state of staff auditors and ultimately causes them to reduce the extent to which they communicate with a client manager to gather the necessary information to perform an audit adequately. I also investigate whether attribute affirmation from a work buddy helps elicit positive affect to mitigate the effects that exposure to negative generational stereotypes may have on audit evidence collection. I conducted a 2 x 2 experiment using graduate auditing students as a proxy for staff auditors. I find that general affect (i.e., mood) rather than interpersonal affect (i.e., likability), drives the negative effect of exposure to generational stereotypes on willingness to collect more audit evidence. I also find that high levels of negative mood can negatively impact participants' self-efficacy. I, however, failed to find evidence of a moderated mediation. The presence of an attribute affirmation results in an insignificant increase in positive affect. When staff auditors are …
Date: May 2023
Creator: Kabutey, Monica
Object Type: Thesis or Dissertation
System: The UNT Digital Library
English and Reading Teachers' Pedagogical Successes and Challenges during the COVID-19 Pandemic (open access)

English and Reading Teachers' Pedagogical Successes and Challenges during the COVID-19 Pandemic

This qualitative descriptive case study examines the pedagogical teaching and instructional practices of fifth, sixth and eighth grade Texas public school English/reading teachers. This study shares the description of each teachers' English and Reading pedagogy, instructional practices, and their successes and/or challenges prior to and during the pandemic. The participants of the study were from two different school districts in Texas. The study utilized surveys and semi-structured interviews as sources of data that revealed reading pedagogy and a self-assessment of reading pedagogy practices prior to and during the COVID-19 pandemic. Three conclusive themes emerged after analysis of the data: importance of social emotional wellness of students, teaching and learning became a one size fits all approach, and varied levels of student engagement. Recommendations from this study for educational practitioners include a need to value the importance of the teacher-student relationship and the powerful role it plays in each student's emotional wellness and learning. Practitioners will need to reflect on what the COVID-19 pandemic taught the educational system about digital platforms and learning. Practitioners in the field should consider how the lingering effects of the COVID-19 pandemic will impact instructional design, teaching, content pedagogy, student academic gaps and academic progress or …
Date: May 2023
Creator: Goodwin, LaTasha Lynee Brown
Object Type: Thesis or Dissertation
System: The UNT Digital Library
How Receiving Communities Structure Refugee Settlement Experiences: The Case of Burmese Immigrants in DFW (open access)

How Receiving Communities Structure Refugee Settlement Experiences: The Case of Burmese Immigrants in DFW

The Dallas-Forth Worth Metroplex (DFW) serves as a diverse resettlement location for globally displaced refugees. While research examines how the nation impacts refugee resettlement, studies that examine the role of the city and community in placemaking are still lacking. In city resettlement investigations, research often focuses broadly on advocacy and political movements rather than the impacts of local-level structures and policies. In this paper, I develop an evaluation model using Jenny Phillimore's categories for successful refugee resettlement that examines how structural barriers, community interactions, and resource accessibility affect space and place for refugee populations. Through an ethnography of Chin and Rohingya refugee communities in DFW, I explore the differences between community-settled and state-settled refugee groups and the idea of an integrated resettlement program. Additionally, I argue that refugees who choose their settlement location in the United States are empowered and thus have a stronger connection to their host community than state-settled refugees. For example, in interviews, the Chin emphasized their ownership of Lewisville and feelings of home, while the Rohingya expressed feelings of placelessness and dispossession in Dallas. As governments push towards an entirely privatized system of refugee resettlement, this research argues for an integrated method that draws upon federal …
Date: May 2023
Creator: Stewart, Kaitlin Victoria
Object Type: Thesis or Dissertation
System: The UNT Digital Library
On Sharp Permutation Groups whose Point Stabilizers are Certain Frobenius Groups (open access)

On Sharp Permutation Groups whose Point Stabilizers are Certain Frobenius Groups

We investigate non-geometric sharp permutation groups of type {0,k} whose point stabilizers are certain Frobenius groups. We show that if a point stabilizer has a cyclic Frobenius kernel whose order is a power of a prime and Frobenius complement cyclic of prime order, then the point stabilizer is isomorphic to the symmetric group on 3 letters, and there is up to permutation isomorphism, one such permutation group. Further, we determine a significant structural description of non-geometric sharp permutation groups of type {0,k} whose point stabilizers are Frobenius groups with elementary abelian Frobenius kernel K and Frobenius complement L with |L| = |K|-1. As a result of this structural description, it is shown that the smallest non-solvable Frobenius group cannot be a point stabilizer in a non-geometric sharp permutation group of type {0,k}.
Date: May 2023
Creator: Norman, Blake Addison
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Consideration of Dynamic Assessment to Identify Gifted, Emerging Bilingual Latinx Students: Lessons for School Leaders (open access)

Consideration of Dynamic Assessment to Identify Gifted, Emerging Bilingual Latinx Students: Lessons for School Leaders

Little, if any, research exists that provides guidance for educators on the use of a dynamic assessment as a tool for better identifying Latinx students for gifted programs. The purpose of this qualitative case study was to explore the perceptions of campus principals and elementary teachers as dynamic assessment was being considered as part of the gifted and talented identification protocol. Data were collected through teacher and principal interviews and focus groups, along with an analysis of current practices and protocols within the studied district. The findings revealed several key themes that emerged from educator perspectives on the ability of emergent bilingual students to be placed in gifted programs and how dynamic assessment could or could not play a part in the assessment process. The study provides support and context for future research about dynamic assessment as applied to gifted and talented identification of Latinx students, including (a) the development of a dynamic assessment, (b) the implementation of a dynamic assessment with presentation of data that supports or do not support its use, (c) training to support the implementation of a dynamic assessment, (d) the human capital and time associated with implementing a dynamic assessment, and (e) educator mindset associated …
Date: May 2023
Creator: Toy, Adam P.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Asymptotic Formula for Counting in Deterministic and Random Dynamical Systems (open access)

Asymptotic Formula for Counting in Deterministic and Random Dynamical Systems

The lattice point problem in dynamical systems investigates the distribution of certain objects with some length property in the space that the dynamics is defined. This problem in different contexts can be interpreted differently. In the context of symbolic dynamical systems, we are trying to investigate the growth of N(T), the number of finite words subject to a specific ergodic length T, as T tends to infinity. This problem has been investigated by Pollicott and Urbański to a great extent. We try to investigate it further, by relaxing a condition in the context of deterministic dynamical systems. Moreover, we investigate this problem in the context of random dynamical systems. The method for us is considering the Fourier-Stieltjes transform of N(T) and expressing it via a Poincaré series for which the spectral gap property of the transfer operator, enables us to apply some appropriate Tauberian theorems to understand asymptotic growth of N(T). For counting in the random dynamics, we use some results from probability theory.
Date: May 2023
Creator: Naderiyan, Hamid
Object Type: Thesis or Dissertation
System: The UNT Digital Library
"Doble Identidad" (open access)

"Doble Identidad"

Doble Identidad conveys my experience as someone who struggles with their cultural identity. Through the expository modes of self-reflexivity, participatory, experimental, and poetics, the film displays the factors that molded my cultural identity. My childhood memories and interactions with my loved ones help me tell the story of how my cultural identity has and continues to leave me with feelings of inadequacy of not being Mexican or American enough.
Date: May 2023
Creator: Huerta-Ortega, Katherine Leilani
Object Type: Thesis or Dissertation
System: The UNT Digital Library

Coercion and Consent among Employer-Sponsored and Dependent Visa Holders: A Study of Indian Workers in the U.S. Information Technology Sector

Highly educated and skilled Indian nationals are the largest recipients of H-1B visas in the US. An employer must be willing to sponsor an H-1B work visa for the worker to continue to live and work in the US. This stipulation has granted US employers unprecedented power over H-1B visa holders, which can be understood as status coercion; employers have state-sanctioned power to threaten or discharge a worker from their status, i.e., visa status, which interconnects work and migration status. While the expansive power of employers to curtail a worker's status is one factor driving the ongoing coercive conditions, the other factor is precarious work. There is a gap in the literature in understanding what occurs at the intersection of status coercion and precarious work, especially within high-skilled information technology (IT) jobs. For instance, how does status coercion operate for employer-sponsored H-1B visa holders? Is it similar for dependent visa workers on H-4 EAD visas that rely on their spouse's H-1B, and F-1 OPT visa workers who have employment authorization from USCIS? Lastly, do these visa workers ever resist status coercion? In this study, I draw on twelve in-depth, semi-structured interviews of Indian nationals in the IT sector on H-1B, …
Date: May 2023
Creator: Jangeti, Neha
Object Type: Thesis or Dissertation
System: The UNT Digital Library
The Role of Counselor Trainees' Co-Regulated Mindfulness: A Cluster-Randomized Controlled Study (open access)

The Role of Counselor Trainees' Co-Regulated Mindfulness: A Cluster-Randomized Controlled Study

Mindfulness is a practice that has the potential to help counseling students build a variety of skills that are necessary for clinical efficacy, including therapeutic presence, attunement, empathy, cognitive flexibility, and non-reactivity. However, mindfulness is rarely taught to students in mental health training programs, which makes it an untapped possibility to improve counselor education. Additionally, rarely do researchers explore the role of counselor mindfulness and counselor trauma on clients' perceptions of therapeutic presence. Therefore, the purpose of this study is to explore the effects of a 15-week mindfulness training program for counseling students to understand its effect on client's perceptions of therapeutic presence, counselor state mindfulness development, and counselor trauma symptoms. Participants in this cluster-randomized controlled intervention were masters counseling students currently enrolled in clinical practicum accredited by the Counsel for the Accreditation of Counseling and Related Educational Programs (CACREP). Counselors provided data at three timepoints on their state mindfulness, trauma symptoms, and therapeutic presence. Clients provided data at three timepoints on their perceptions of their counselor's therapeutic presence. We analyzed data through repeated measures ANOVA and two-level longitudinal hierarchical linear models. Implications for counselor education, professional counselor development, and future research are offered and limitations are discussed.
Date: May 2023
Creator: Warwick, Lindsey A.
Object Type: Thesis or Dissertation
System: The UNT Digital Library

Development of Biomimetic Human Lung Alveolus Chip

The potential of physiologically relevant in vitro cell culture models for studying physiological and pathophysiological phenomena has been widely recognized as replacements for animal and conventional in vitro models. To create models that accurately replicate the structure and function of tissues and organs, it is essential to comprehend the biophysical and mechanical features of the extracellular matrix (ECM) and incorporate them into the in vitro cell culture models. Therefore, we first aimed to investigate how nanotopography can modulate cell behaviors by studying cell behaviors on nanostructures of various aspect ratios on a cobalt-chromium-molybdenum (CoCrMo) alloy surface. We also explored the impact of nanofibrous membranes on the formation of alveolar epithelium, which is critical for lung alveolar interstitium chips. In addition, we investigated the effect of mechanical stretch on cell behaviors and focused on how the dimensionality of the stretch affects cell behaviors. To create physiologically relevant in vitro models based on our findings, we engineered a stem cell niche using a combination of nanofibrous membranes, mechanical stretch, and a soft substrate, and evaluated its impact on stem cell behaviors. Finally, we created a biomimetic human lung interstitium chip for application in physiological and pathophysiological in vitro studies.
Date: May 2023
Creator: Man, Kun
Object Type: Thesis or Dissertation
System: The UNT Digital Library

Extending the Capabilities of Continuum Embeddings in First-Principle Simulations of Materials

In recent years, continuum models of solvation have had exceptional success in materials simulations as well as condensed matter physics. They can easily capture the effects of disordered systems, such as neutral liquids or electrolytes solutions, on material interfaces without the need for expensive statistical sampling. The Environ library (www.quantum-environ.org) implements different continuum models and correction schemes, which is the focus of this presentation. Recently refactored into a stand-alone library, many changes have been introduced in Environ, making it more flexible and computationally efficient. Introduction of a double-cell formalism allows for faster ab initio DFT calculations while reparameterization of soft-sphere continuum model allows for smaller density cutoffs. Furthermore, Environ's periodic boundary conditions correction schemes have been expanded by including the AFC90 library, which allows for faster DFT calculations of partially periodic systems, such as slabs, wires, and isolated molecules. Finally, stand-alone Environ can now provide atomic and molecular descriptors, which can be used to characterize solvated interfaces, e.g. in machine learning applications. The specific details of the implementations are reviewed as well as their efficiency and some choice applications for different calculation setups and systems.
Date: May 2023
Creator: Medrano, Gabriel
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Renewable Electricity in DFW: Access, Distribution, and Consumer Awareness (open access)

Renewable Electricity in DFW: Access, Distribution, and Consumer Awareness

Texas is the leading producer of renewable energy in the U.S, and Dallas-Fort Worth (DFW) is the largest metropolitan area in the state. Texas has a deregulated energy market, with three types of providers: privatized, public-owned, and co-operatives. Privatized providers compete in the deregulated market, and consumers choose between hundreds of electricity retailers. Public-owned providers are owned by the municipality, and electricity consumers that live within the city limits must use the municipal provider. Electric co-operatives operate similarly where customers within the region must use the co-operative, but instead of being owned by the city, co-ops are owned by the members (customers). To date, the availability, cost, accessibility, and outreach of renewable electricity among these provider types remains unclear. For this reason, my research examines the renewable energy market in DFW by asking: (1) Who has access to renewable energy and how do they understand it? (2) How do electricity retailers distribute and make renewable energy available? and (3) If consumers can choose their provider, why do they select certain electricity plans over others? My findings suggest that while many consumers want or are open to using renewable energy, uncertainties surrounding how to find or choose a provider, price, and …
Date: May 2023
Creator: Greer, Marissa
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Bridging the Gap between a Healthy Diet and Agroecology in General Pacheco, Argentina (open access)

Bridging the Gap between a Healthy Diet and Agroecology in General Pacheco, Argentina

This study explores the role Comunidad Milpa (Milpa) plays in implementing agroecology food systems in Comunidad Pacheco, Argentina. From teaching residents about food cultivation practices, to the importance of a healthy diet and developing relationship with local agroecology producers, the method builds upon the idea of food sovereignty and self-governance. Research conducted for this study focused on obstacles residents encountered while seeking to incorporate local agroecology foods into their diet. Incentives encouraging residents to support area agroecology efforts were also investigated, as well as barriers producers experienced while marketing their products. Design methods used for the investigation included both qualitative and quantitative methods in the form of surveys and interviews with members and participants of Milpa. Data gathered through both methods resulted in identifying the perspective Milpa participants have of the organization, their food practices and choices, and obstacles food producers encounter within the community.
Date: May 2023
Creator: Meave, Anya Yvonne
Object Type: Thesis or Dissertation
System: The UNT Digital Library