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Detection and Classification of Heart Sounds Using a Heart-Mobile Interface (open access)

Detection and Classification of Heart Sounds Using a Heart-Mobile Interface

An early detection of heart disease can save lives, caution individuals and also help to determine the type of treatment to be given to the patients. The first test of diagnosing a heart disease is through auscultation - listening to the heart sounds. The interpretation of heart sounds is subjective and requires a professional skill to identify the abnormalities in these sounds. A medical practitioner uses a stethoscope to perform an initial screening by listening for irregular sounds from the patient's chest. Later, echocardiography and electrocardiography tests are taken for further diagnosis. However, these tests are expensive and require specialized technicians to operate. A simple and economical way is vital for monitoring in homecare or rural hospitals and urban clinics. This dissertation is focused on developing a patient-centered device for initial screening of the heart sounds that is both low cost and can be used by the users on themselves, and later share the readings with the healthcare providers. An innovative mobile health service platform is created for analyzing and classifying heart sounds. Certain properties of heart sounds have to be evaluated to identify the irregularities such as the number of heart beats and gallops, intensity, frequency, and duration. Since …
Date: December 2016
Creator: Thiyagaraja, Shanti
System: The UNT Digital Library
Local Phase Manipulation for Multi-Beam Interference Lithography for the Fabrication of Two and Three Dimensional Photonic Crystal Templates (open access)

Local Phase Manipulation for Multi-Beam Interference Lithography for the Fabrication of Two and Three Dimensional Photonic Crystal Templates

In this work, we study the use of a spatial light modulator (SLM) for local manipulation of phase in interfering laser beams to fabricate photonic crystal templates with embedded, engineered defects. A SLM displaying geometric phase patterns was used as a digitally programmable phase mask to fabricate 4-fold and 6-fold symmetric photonic crystal templates. Through pixel-by-pixel phase engineering, digital control of the phases of one or more of the interfering beams was demonstrated, thus allowing change in the interference pattern. The phases of the generated beams were programmed at specific locations, resulting in defect structures in the fabricated photonic lattices such as missing lattice line defects, and single-motif lattice defects in dual-motif lattice background. The diffraction efficiency from the phase pattern was used to locally modify the filling fraction in holographically fabricated structures, resulting in defects with a different fill fraction than the bulk lattice. Through two steps of phase engineering, a spatially variant lattice defect with a 90° bend in a periodic bulk lattice was fabricated. Finally, by reducing the relative phase shift of the defect line and utilizing the different diffraction efficiency between the defect line and the background phase pattern, desired and functional defect lattices can be …
Date: December 2016
Creator: Lutkenhaus, Jeffrey Ryan
System: The UNT Digital Library
Chemical and Electronic Structure of Aromatic/Carborane Composite Films by PECVD for Neutron Detection (open access)

Chemical and Electronic Structure of Aromatic/Carborane Composite Films by PECVD for Neutron Detection

Boron carbide-aromatic composites, formed by plasma-enhanced co-deposition of carboranes and aromatic precursors, present enhanced electron-hole separation as neutron detector. This is achieved by aromatic coordination to the carborane icosahedra and results in improved neutron detection efficiency. Photoemission (XPS) and FTIR suggest that chemical bonding between B atoms in icosahedra and aromatic contents with preservation of π system during plasma process. XPS, UPS, density functional theory (DFT) calculations, and variable angle spectroscopic ellipsometery (VASE) demonstrate that for orthocarborane/pyridine and orthocarborane/aniline films, states near the valence band maximum are aromatic in character, while states near the conduction band minimum include those of either carborane or aromatic character. Thus, excitation across the band gap results in electrons and holes on carboranes and aromatics, respectively. Further such aromatic-carborane interaction dramatically shrinks the indirect band gap from 3 eV (PECVD orthocarborane) to ~ 1.6 eV (PECVD orthocarborane/pyridine) to ~1.0 eV (PECVD orthocarborane/aniline), with little variation in such properties with aromatic/orthocarborane stoichiometry. The narrowed band gap indicate the potential for greatly enhanced charge generation relative to PECVD orthocarborane films, as confirmed by zero-bias neutron voltaic studies. The results indicate that the enhanced electron-hole separation and band gap narrowing observed for aromatic/orthocarborane films relative to PECVD orthocarborane, …
Date: December 2016
Creator: Dong, Bin
System: The UNT Digital Library
Loyalty and Fairness: A Study of the Influence of Moral Foundations on Auditors' Propensity to Subordinate their Judgment (open access)

Loyalty and Fairness: A Study of the Influence of Moral Foundations on Auditors' Propensity to Subordinate their Judgment

Subordination of judgment is a fundamental threat to auditor objectivity. Subordination of judgment occurs when auditors agree with their superiors either in spite of or without forming their own independent judgments. Many audit procedures rely on independent, critical thinking at every level of the audit team; however, a number of studies suggest that auditors tend to agree with superiors even when a superior's views clearly run contrary to generally accepted accounting principles. While there is general agreement among scholars that subordination of judgment is "bad," very little attention has been given to moral biases that might influence an auditor's tendency to subordination of judgment, or to potential remedies that could mitigate an auditor's tendency to subordinate judgment. Moral Foundations Theory suggests that individuals tend to make intuitive, normative evaluations of situations based upon a set of personal moral biases or preferences called "moral foundations." Two specific moral foundations could influence subordination of judgment in divergent ways. The moral foundation of loyalty-respect may make agreement with a superior's views seem more acceptable than would disagreement. Meanwhile, the moral foundation of fairness may make an auditor more sensitive to the observance of rules, resulting in less subordination of judgment when a superior's …
Date: December 2016
Creator: Neri, Marc P.
System: The UNT Digital Library
A History of Overcoming: Nietzsche on the Moral Antecedents and Successors of Modern Liberalism (open access)

A History of Overcoming: Nietzsche on the Moral Antecedents and Successors of Modern Liberalism

This work aims to understand human moral psychology under modern liberalism by analyzing the mature work of philosopher Friedrich Nietzsche. I seek to understand and evaluate Nietzsche's claim that liberalism, rather than being an overturning of slave morality, is an extension of the slave morality present in both Judaism and Christianity. To ground Nietzsche's critique of liberalism theoretically, I begin by analyzing his "master" and "slave" concepts. With these concepts clarified, I then apply them to Nietzsche's history by following his path from Judaism to liberalism and beyond--to his "last man" and Übermensch. I find that Nietzsche views history as a series of overcomings wherein a given mode of power maintenance runs counter to the means by which power was initially attained. Liberalism, as the precursor and herald of the "last man," threatens the end of overcoming and therefore compromises the future of human valuation and meaning.
Date: December 2016
Creator: Gill, Rodney W.
System: The UNT Digital Library
Evolving Curricular Models in Culinary Arts: An Instrumental Case Study of a Technical Field (open access)

Evolving Curricular Models in Culinary Arts: An Instrumental Case Study of a Technical Field

The purpose of this research study was to examine how chefs and other individuals in the food industry understood the field of culinary arts. This study used an instrumental case study with purposeful sampling of multiple cases. Through a series of open-ended interviews using snowball-sampling strategy that concluded with 45 participants sharing their experiences in culinary education and employment, several themes emerged across all of the interviews: (1) Disempowerment of those who have been successful in the culinary arts; (2) Conflict in the field; and, (3) Needs of employers not being met. Following the analysis of the data, two research questions were inductively formed: (1) How do the participants' understandings vary based upon the three models (apprenticeship, associate degree, and baccalaureate degree) of culinary education? (2) How do these themes vary depending upon the three models of culinary education? What resulted was thick description of the impact of the three models of formal chef education has had on the field of culinary arts, followed by the potential in the development of the baccalaureate degree model as it represented an opportunity for field redefinition in culinary arts. This study produced a set of data revealing that current culinary education has become …
Date: December 2016
Creator: Cossio, Allison
System: The UNT Digital Library
Defect Behaviors in Zinc Oxide and Zinc Titanates Ceramics from First Principles Computer Simulations (open access)

Defect Behaviors in Zinc Oxide and Zinc Titanates Ceramics from First Principles Computer Simulations

ZnO and ZnO-TiO2 ceramics have intriguing electronic and mechanical properties and find applications in many fields. Many of these properties and applications rely on the understanding of defects and defect processes in these oxides as these defects control the electronic, catalytic and mechanical behaviors. The goal of this dissertation is to systematically study the defects and defects behaviors in Wurtzite ZnO and Ilmenite ZnTiO3 by using first principles calculations and classical simulations employing empirical potentials. Firstly, the behavior of intrinsic and extrinsic point defects in ZnO and ZnTiO3 ceramics were investigated. Secondly, the effect of different surface absorbents and surface defects on the workfunction of ZnO were studied using DFT calculations. The results show that increasing the surface coverage of hydrocarbons decreased the workfunction. Lastly, the stacking fault behaviors on ilmenite ZnTiO3 were investigated by calculating the Generalized Stacking Fault (GSF) energies using density functional theory based first principles calculations and classical calculations employing effective partial charge inter-atomic potentials. The gamma-surfaces of two low energy surfaces, (110) and (104), of ZnTiO3 were fully mapped and, together with other analysis such as ideal shear stress calculations.
Date: December 2016
Creator: Sun, Wei
System: The UNT Digital Library
Effect of Makerspace Professional Development Activities on Elementary and Middle School Educator Perceptions of  Integrating Technologies with STEM (Science,  Technology, Engineering, Mathematics) (open access)

Effect of Makerspace Professional Development Activities on Elementary and Middle School Educator Perceptions of Integrating Technologies with STEM (Science, Technology, Engineering, Mathematics)

This study investigated a Makerspace professional development program, the Makers' Guild, provided to teachers within north Texas over the course of a semester. The research employed a constructionist approach delivered via 2D and 3D technologies during STEM instructional activities within a creative space. Participants reported statistically significant increases in self-reported competence in technology integration, confidence levels toward integrating World Wide Web, Emerging Technologies for Student Learning, Teacher Professional Development, and attitudes toward math, technology, science, and STEM careers.
Date: December 2016
Creator: Miller, Jennifer R
System: The UNT Digital Library
Legal Compliance in Guardianship Cases An Exploratory Study: Investigating Denton County Probate Court Visitors' Program Success with Legal Compliance in Guardianship Cases in 2013 (open access)

Legal Compliance in Guardianship Cases An Exploratory Study: Investigating Denton County Probate Court Visitors' Program Success with Legal Compliance in Guardianship Cases in 2013

Dabner, Carol P. Legal Compliance in Guardianship Cases. An Exploratory Study: Investigating Denton County Probate Court Visitors' Program Success with Legal Compliance in Guardianship Cases. Doctor of Philosophy (Applied Gerontology), December 2016, 140 pp., 18 tables, references, 20 titles. Aim: To evaluate the effectiveness of the legal compliance of the Denton County Probate Court Visitor's program in the year 2013. Rationale: Guardianship case management success is based on the presence of legal compliance of both guardians and the Court. When a guardian is legally compliant, a ward is receiving the statutorily minimum standards of care. Legal compliance equates (evidence of) the Ward receiving legally sufficient care. Research has not been vast; it has been consistent as to necessity of guardianship training, monitoring, and narrow focus of research. Evidence based research will assist in defining and developing appropriate court monitoring programs, which can add to the quality of care for elderly and disabled adults. Methods: 1,300 guardianship cases in the probate court. Of these cases, 910 had annual reports of the person filed, which 304 were reviewed using the Legal Compliance Audit. Eight (8) factors of compliance were reviewed with three (3) being Court actions and five (5) being guardian actions. …
Date: December 2016
Creator: Dabner, Carol Patrice
System: The UNT Digital Library
The Role of Misfit Strain and Oxygen Content on Formation and Evolution of Omega Precipitate in Metastable Beta-titanium Alloys (open access)

The Role of Misfit Strain and Oxygen Content on Formation and Evolution of Omega Precipitate in Metastable Beta-titanium Alloys

β-Ti alloys are widely used in airframe and biomedical applications due to their high ductility, high hardenability, and low elastic modulus. The phase transformations in β-Ti alloys are rather complex due to formation of metastable phases during various thermo-mechanical treatments. One such critical metastable phase, the hexagonal omega (ω) phase, can form in β-Ti alloys under quenching from the high temperature β phase and/or isothermal aging at intermediate temperature. Despite a substantial amount of reported works on the ω phase, there are several critical issues related to the ω formation need to be resolved, e.g. role of alloying elements and oxygen content. Therefore, this dissertation has attempted to provide insights into ω transformation in low misfit (Ti-Mo) and high misfit (Ti-V) binary systems as well as multicomponent (Ti-Nb-Zr-Ta) alloys. The evolution of ω structure, morphology and composition from the early stage (β-solution+quenched) to later stages after prolonged aging are systematically investigated by coupling transmission electron microscopy (TEM), atom probe tomography (APT) and high-energy synchrotron X-ray diffraction techniques. The influence of aging temperature and duration on characteristic of ω phase in Ti-Mo, and Ti-V alloys is addressed in details. It is found that compositional changes during aging can alter the structure, …
Date: December 2016
Creator: Hendrickson, Mandana
System: The UNT Digital Library
Determinants of Women's Autonomy in Nepal (open access)

Determinants of Women's Autonomy in Nepal

Nepal in recent times has witnessed a proliferation of community-based organization (CBOs). Established by local residents, CBOs are small level organizations that promote and defend the rights and interests of people especially that of minorities and the disadvantaged. One such minority group that CBOs greatly focus on are women. Despite dramatic increase in the number of CBOs in Nepal its impact on women is understudied. The purpose of this dissertation is to analyze the relationship between Nepalese women's participation in CBOs and their autonomy. Autonomy comprises of four different dimensions; physical mobility, financial autonomy, household decision-making, and reproductive autonomy. Modifying the conceptual framework used by Mahmud, Shah, and Becker in 2012, I hypothesize that women who participate in CBOs experience greater autonomy. Data from the 2008 Chitwan Valley Family Study is used for analysis. Using SPSS, separate logistic regressions are run to analyze the relationship between CBO membership and the dimensions of autonomy. The results support three of the four proposed major hypotheses. Nepalese women who participate in CBOs have greater autonomy in terms of physical mobility, financial autonomy, and household decision-making. No evidence was found to establish link between CBO membership and reproductive autonomy. The variables that are controlled …
Date: December 2016
Creator: Neupane, Diptee
System: The UNT Digital Library
The Impact of Psychotherapeutic Reiki on Anxiety and Mindfulness: A Single-Case Design (open access)

The Impact of Psychotherapeutic Reiki on Anxiety and Mindfulness: A Single-Case Design

Reiki healing is one of several complementary and integrative therapies becoming increasingly prevalent in mental health counseling. It has been identified in the medical field for its usefulness in treating anxiety, depression, distress, and pain but has rarely been studied for its counseling impact on client wellness. I conducted single-case research to explore psychotherapeutic Reiki's (PR's) influence on adult clients' anxiety symptoms and perceived sense of mindfulness and provided analysis of data collected from two assessments administered weekly: the Adult Manifest Anxiety Scale-Adult and the Mindful Attention Awareness Scale. Three of the four participants demonstrated significant improvement in both anxiety and mindfulness over the course of the PR intervention. The study revealed potential therapeutic benefits for integrating PR with conventional talk therapy. Included in discussion of study results are clinical implications and importance, suggestions for future research, and limitations.
Date: December 2016
Creator: Webster, Lindsay
System: The UNT Digital Library
Influence of Underlying Random Walk Types in Population Models on Resulting Social Network Types and Epidemiological Dynamics (open access)

Influence of Underlying Random Walk Types in Population Models on Resulting Social Network Types and Epidemiological Dynamics

Epidemiologists rely on human interaction networks for determining states and dynamics of disease propagations in populations. However, such networks are empirical snapshots of the past. It will greatly benefit if human interaction networks are statistically predicted and dynamically created while an epidemic is in progress. We develop an application framework for the generation of human interaction networks and running epidemiological processes utilizing research on human mobility patterns and agent-based modeling. The interaction networks are dynamically constructed by incorporating different types of Random Walks and human rules of engagements. We explore the characteristics of the created network and compare them with the known theoretical and empirical graphs. The dependencies of epidemic dynamics and their outcomes on patterns and parameters of human motion and motives are encountered and presented through this research. This work specifically describes how the types and parameters of random walks define properties of generated graphs. We show that some configurations of the system of agents in random walk can produce network topologies with properties similar to small-world networks. Our goal is to find sets of mobility patterns that lead to empirical-like networks. The possibility of phase transitions in the graphs due to changes in the parameterization of agent …
Date: December 2016
Creator: Kolgushev, Oleg
System: The UNT Digital Library
Women Chief Housing Officers at State Universities in the Northwest United States (open access)

Women Chief Housing Officers at State Universities in the Northwest United States

Hyatt, Jennifer Leigh. Women Chief Housing Officers at State Universities in the Northwest United States. Doctor of Education (Higher Education), December 2016, 89 pp., 1 table, 3 figures, 48 references, titles. This qualitative study explored the experiences of women chief housing officers (CHOs) at state universities within the northwest region of the United States. The study used narrative inquiry methodology with a thematic analysis approach to investigate how seven female CHOs experience and make meaning of their professional career progression and journey toward becoming and remaining a CHO. Five core themes emerged from the study: (a) understanding housing operations, (b) self-efficacy, (c) gender inequities, (d) relationships with staff, and (e) mentorship. The theme of gender identity suggests that gender does influence how these female CHOs make meaning of their professional experience. The overall results suggest that although the perception of many is that the field of student affairs is wide open to women, in some senior-level positions, such as CHO, gender inequity is prevalent. A factor that may contribute to this inequity is the privatization of housing which calls for a greater understanding of business and housing operations, areas dominated by males. An implication from this study is that an …
Date: December 2016
Creator: Hyatt, Jennifer
System: The UNT Digital Library
Wake (open access)

Wake

Preface: A consideration of the New Sincerity movement in contemporary American poetics in the work of Tao Lin, Matt Hart, and Dorothea Lasky. Creative work: A three section book of poetry exploring elegy, form, and the intersection of strangeness and domesticity.
Date: December 2016
Creator: Beard, Christopher Aaron
System: The UNT Digital Library
Clinical Symptoms and Signs Related to Voice Disorders among Collegiate-Level Singers: A Retrospective Study (open access)

Clinical Symptoms and Signs Related to Voice Disorders among Collegiate-Level Singers: A Retrospective Study

The objectives of this research were to (1) characterize the demographics and vocal health history of collegiate-level singers, particularly those with a voice disorder and (2) describe and compare self-reported symptoms of singers across diagnostic categories of vocal fold disorders. Clinical reports of 56 collegiate-level singers (15 male and 41 female) who visited the Voice Diagnostic Clinic at the University of North Texas for voice evaluations between 2010 and 2015 were reviewed. Information was extracted from clinical records including demographic data, vocal health history, self-reported voice-related symptoms, and voice diagnosis confirmed by strobolaryngoscopic examinations and phonatory function testing. Diagnoses of voice disorders were grouped under three categories: normal (i.e., no perceptible pathology), benign lesions and irritation/inflammation. Seven singers were diagnosed as normal, 27 (51.8%) with benign lesions, and 22 (39.3%) with irritation/inflammation. All singers diagnosed as normal were females. Female singers have twice as many benign lesions as irritation/inflammation whereas males presented the opposite pattern. Nodules, polyps, cysts and irritation/inflammation were the most common voice disorders. Singers with allergies and a past history of voice problems demonstrated a higher incidence of voice disorders. The top five self-reported vocal symptoms were worse voice in the morning (50%), pain in throat (46.4%), …
Date: December 2016
Creator: Mohr, Caitlin
System: The UNT Digital Library
Low-Energy Electron Irradiation of Preheated and Gas-Exposed Single-Wall Carbon Nanotubes (open access)

Low-Energy Electron Irradiation of Preheated and Gas-Exposed Single-Wall Carbon Nanotubes

We investigate the conditions under which electron irradiation of single-walled carbon nanotube (SWCNT) bundles with 2 keV electrons produces an increase in the Raman D peak. We find that an increase in the D peak does not occur when SWCNTs are preheated in situ at 600 C for 1 h in ultrahigh vacuum (UHV) before irradiation is performed. Exposing SWCNTs to air or other gases after preheating in UHV and before irradiation results in an increase in the D peak. Small diameter SWCNTs that are not preheated or preheated and exposed to air show a significant increase in the D and G bands after irradiation. X-ray photoelectron spectroscopy shows no chemical shifts in the C1s peak of SWCNTs that have been irradiated versus SWCNTs that have not been irradiated, suggesting that the increase in the D peak is not due to chemisorption of adsorbates on the nanotubes.
Date: December 2016
Creator: Ecton, Philip
System: The UNT Digital Library
Contributions to Descriptive Set Theory (open access)

Contributions to Descriptive Set Theory

Assume AD+V=L(R). In the first chapter, let W^1_1 denote the club measure on \omega_1. We analyze the embedding j_{W^1_1}\restr HOD from the point of view of inner model theory. We use our analysis to answer a question of Jackson-Ketchersid about codes for ordinals less than \omega_\omega. In the second chapter, we provide an indiscernibles analysis for models of the form L[T_n,x]. We use our analysis to provide new proofs of the strong partition property on \delta^1_{2n+1}
Date: December 2016
Creator: Dance, Cody
System: The UNT Digital Library
Rankin-Cohen Brackets for Hermitian Jacobi Forms and Hermitian Modular Forms (open access)

Rankin-Cohen Brackets for Hermitian Jacobi Forms and Hermitian Modular Forms

In this thesis, we define differential operators for Hermitian Jacobi forms and Hermitian modular forms over the Gaussian number field Q(i). In particular, we construct Rankin-Cohen brackets for such spaces of Hermitian Jacobi forms and Hermitian modular forms. As an application, we extend Rankin's method to the case of Hermitian Jacobi forms. Finally we compute Fourier series coefficients of Hermitian modular forms, which allow us to give an example of the first Rankin-Cohen bracket of two Hermitian modular forms. In the appendix, we provide tables of Fourier series coefficients of Hermitian modular forms and also the computer source code that we used to compute such Fourier coefficients.
Date: December 2016
Creator: Martin, James D. (James Dudley)
System: The UNT Digital Library
Real Time Assessment of a Video Game Player's State of Mind Using Off-the-Shelf Electroencephalography (open access)

Real Time Assessment of a Video Game Player's State of Mind Using Off-the-Shelf Electroencephalography

The focus of this research is on the development of a real time application that uses a low cost EEG headset to measure a player's state of mind while they play a video game. Using data collected using the Emotiv EPOC headset, various EEG processing techniques are tested to find ways of measuring a person's engagement and arousal levels. The ability to measure a person's engagement and arousal levels provide an opportunity to develop a model that monitor a person's flow while playing video games. Identifying when certain events occur, like when the player dies, will make it easier to identify when a player has left a state of flow. The real time application Brainwave captures data from the wireless Emotiv EPOC headset. Brainwave converts the raw EEG data into more meaningful brainwave band frequencies. Utilizing the brainwave frequencies the program trains multiple machine learning algorithms with data designed to identify when the player dies. Brainwave runs while the player plays through a video gaming monitoring their engagement and arousal levels for changes that cause the player to leave a state of flow. Brainwave reports to researchers and developers when the player dies along with the identification of the players …
Date: December 2016
Creator: McMahan, Timothy
System: The UNT Digital Library
The Effects of Student-Perceived Instructor Demotivating Behaviors on Doctoral Students' Information Seeking Behaviors (open access)

The Effects of Student-Perceived Instructor Demotivating Behaviors on Doctoral Students' Information Seeking Behaviors

In their studies on student motivation in th4e 1990s, Gorham & Christophel and Christophel & Gorham found that students perceived their own demotivation to be caused by instructor behaviors. While there are studies that explore the topic of student demotivation and other studies that illustrate the great influence instructors have on student information seeking behaviors, research focusing on the connection between these two concepts is almost nonexistent. Using Gorham & Christophel's concept of instructor-owned student demotivation, this mixed-methods study sought to identify which instructor behaviors doctoral computer science and information science students found demotivating and to what extent their perceptions of these demotivating instructor behaviors influenced their information seeking behaviors in a face-to-face classroom. Demographic and student-perceived demotivating instructor behavior surveys along with semi-structured interviews and follow-up questions were used to collect data. The surveys will be analyzed using descriptive statistics in Excel, and the semi-structured interviews and follow up questions were analyzed using content analysis and Colaizzi's method of phenomenological enquiry in NVivo. The findings showed that instructor demotivating behaviors not only influence student information seeking behaviors in the classroom, but they also can lead to lasting effects on the student. In addition, the participants have expectations of instructor …
Date: December 2016
Creator: Cantu, Brenda Ann
System: The UNT Digital Library
A Decomposition of the Group Algebra of a Hyperoctahedral Group (open access)

A Decomposition of the Group Algebra of a Hyperoctahedral Group

The descent algebra of a Coxeter group is a subalgebra of the group algebra with interesting representation theoretic properties. For instance, the natural map from the descent algebra of the symmetric group to the character ring is a surjective algebra homomorphism, so the descent algebra implicitly encodes information about the representations of the symmetric group. However, this property does not hold for other Coxeter groups. Moreover, a complete set of primitive idempotents in the descent algebra of the symmetric group leads to a decomposition of the group algebra as a direct sum of induced linear characters of centralizers of conjugacy class representatives. In this dissertation, I consider the hyperoctahedral group. When the descent algebra of a hyperoctahedral group is replaced with a generalization called the Mantaci-Reutenauer algebra, the natural map to the character ring is surjective. In 2008, Bonnafé asked whether a complete set of idempotents in the Mantaci-Reutenauer algebra could lead to a decomposition of the group algebra of the hyperoctahedral group as a direct sum of induced linear characters of centralizers. In this dissertation, I will answer this question positively and go through the construction of the idempotents, conjugacy class representatives, and linear characters required to do so.
Date: December 2016
Creator: Tomlin, Drew E
System: The UNT Digital Library
Ion Beam Synthesis of Binary and Ternary Transition Metal Silicide Thin Films (open access)

Ion Beam Synthesis of Binary and Ternary Transition Metal Silicide Thin Films

Among the well-known methods to form or modify the composition and physical properties of thin films, ion implantation has shown to be a very powerful technique. In particular, ion beam syntheses of binary iron silicide have been studied by several groups. Further, the interests in transition metal silicide systems are triggered by their potential use in advanced silicon based opto-electronic devices. In addition, ternary silicides have been by far less studied than their binary counterparts despite the fact that they have interesting magnetic and electronic properties. In this study, we investigate ion beam synthesis of Fe-Si binary structures and Fe-Co-Si ternary structures. This work involves fundamental investigation into development of a scalable synthesis process involving binary and ternary transitional metal silicide thin films and Nano-structures using low energy ion beams. Binary structures were synthesized by implanting Fe- at 50 keV energy. Since ion implantation is a dynamic process, Dynamic simulation techniques were used in these studies to determine saturation fluences for ion implantation. Also, static and dynamic simulation results were compared with experimental results. The outcome of simulations and experimental results indicate, dynamic simulation codes are more suitable than static version of the TRIM to simulate high fluence, low energy …
Date: December 2016
Creator: Lakshantha, Wickramaarachchige Jayampath
System: The UNT Digital Library
Building an Understanding of International Service Learning in Librarianship (open access)

Building an Understanding of International Service Learning in Librarianship

From the very beginning, library education has been a mixture of theory and practice. Dewey required apprenticeships to be part of the first library school at the University of Chicago as a method to indoctrinate new professional. Today, acculturation is incorporated into the professional education through a large variety of experiential learning techniques, including internships, practicum, field work, and service learning projects, all of which are designed to develop some level of professional skills within an information organization. But, what is done for understanding library culture? It is said that one cannot truly recognize the extent of one's own cultural assumptions, until they have experienced another. This study followed a group of LIS graduate students that took that next step – going to Russia. By employing a critical hermeneutic methodology, this study sought to understand what value students gain by from working on an assessment project in an international school library. Using a horizon analysis, the researcher established the worldview of participants prior to their departure, analyzed their experience through post-experience interviews, and constructed an understanding of value. Among other concepts, the researcher looked specifically to see whether "library cultural competency", understanding library culture in global context, was developed through …
Date: December 2016
Creator: Walczyk, Christine
System: The UNT Digital Library