UNT Libraries - 18,690 Matching Results

Search Results

Attachment, Coping, and Psychiatric Symptoms among Military Veterans and Active Duty Personnel: A Path Analysis Study

Description: The purpose of this study was to examine the role of attachment processes and coping strategies in the development of psychiatric symptoms among military veterans and active duty personnel. Data were obtained from 268 male and female military veterans and active duty personnel. A path analysis was conducted to estimate the relationships between attachment processes, coping strategies, and psychiatric symptoms. Findings demonstrated that greater levels of attachment anxiety were related to increased levels of avoidant coping and psychiatric symptoms, while higher levels of attachment avoidance were related to avoidant coping and PTSD symptoms, as well as decreased levels of problem-focused coping. Alcohol use was associated with psychiatric symptoms. Avoidant coping, but not problem-focused coping, was associated with psychiatric symptoms and partially mediated the relationship between anxious attachment and psychiatric symptoms. Avoidant coping also fully or partially mediated the relationships of avoidant attachment to depression and PTSD symptoms. The findings of this study increase our knowledge of mechanisms that contribute to psychiatric symptoms among military populations, which in turn can guide treatment planning and interventions.
Access: This item is restricted to UNT Community Members. Login required if off-campus.
Date: December 2017
Creator: Romero, Daniel Hugo

Service Honest and Faithful: The Thirty-Third Volunteer Infantry Regiment in the Philippine War, 1899-1901

Description: This manuscript is a study of the Thirty-Third Infantry, United States Volunteers, a regiment that was recruited in Texas, the South, and the Midwest and was trained by officers experienced from the Indian Wars and the Spanish-American War. This regiment served as a front-line infantry unit and then as a constabulary force during the Philippine War from 1899 until 1901. While famous in the United States as a highly effective infantry regiment during the Philippine War, the unit's fame and the lessons that it offered American war planners faded in time and were overlooked in favor of conventional fighting. In addition, the experiences of the men of the regiment belie the argument that the Philippine War was a brutal and racist imperial conflict akin to later interventions such as the Vietnam War. An examination of the Thirty-Third Infantry thus provides valuable context into a war not often studied in the United States and serves as a successful example of a counterinsurgency.
Date: December 2017
Creator: Andersen, Jack David

The Experience of Language Use for Second Generation, Bilingual, Mexican American, 5th Grade Students

Description: There is a paucity of research regarding language use among bilingual clients, particularly with Latino children. In order to provide culturally sensitive counseling for bilingual, Spanish-speaking, Latino children it is important to understand their experience of language use. The purpose of this study was to investigate how second generation, bilingual, Mexican American, 5th grade students experience language use in the two languages with which they communicate. I employed a phenomenological method to data collection and analysis and conducted semi-structured individual and group interviews with three boys and five girls (N = 8). Analysis of the individual and group interviews yielded four main structures: (a) dominant language determined perception of developing dual selves, (b) speaking two languages useful in language brokering and upward mobility, (c) dominant language determined experience of language use, and (d) language use and aspects of the complementarity principle. Findings from this study suggest that bilingual Latino children experience language brokering for their parents as difficult, speaking two languages as useful regarding upward mobility, and that their dominant language influences various aspects of their daily experiences such as with whom and where they use each language. Limitations to this research include insufficient time building rapport with participants and challenges related to unexplored dimensions of bilingualism in the counseling research literature. An overarching implication for future research, clinical practice, and counselor education is that bilingualism, language use, and the depth of experience of Latino children are largely understudied topics.
Date: December 2017
Creator: Paz, Michael

Molecular Dynamics Simulations of the Structure and Properties of Boron Containing Oxide Glasses: Empirical Potential Development and Applications

Description: Potential parameters that can handle multi-component oxide glass systems especially boron oxide are very limited in literature. One of the main goals of my dissertation is to develop empirical potentials to simulate multi-component oxide glass systems with boron oxide. Two approaches, both by introducing the composition dependent parameter feature, were taken and both led to successful potentials for boron containing glass systems after extensive testing and fitting. Both potential sets can produce reasonable glass structures of the multi-component oxide glass systems, with structure and properties in good agreement with experimental data. Furthermore, we have tested the simulation settings such as system size and cooling rate effects on the results of structures and properties of MD simulated borosilicate glasses. It was found that increase four-coordinated boron with decreasing cooling rate and system size above 1000 atoms is necessary to produce converged structure. Another application of the potentials is to simulate a six-component nuclear waste glass, international simple glass (ISG), which was for first time simulated using the newly developed parameters. Structural features obtained from simulations agree well with the experimental results. In addition, two series of sodium borosilicate and boroaluminosilicate glasses were simulated with the two sets of potentials to compare and evaluate their applicability and deficiency. Various analyses on the structures and properties such as pair distribution function, total correlation function, coordination number analysis, Qn distribution function, ring size distribution function, vibrational density of states and mechanical properties were performed. This work highlights the challenge of MD simulations of boron containing glasses and the capability of the new potential parameters that enable simulations of wide range of mixed former glasses to investigate new structure features and design of new glass compositions for various applications.
Access: This item is restricted to UNT Community Members. Login required if off-campus.
Date: December 2017
Creator: Deng, Lu

"Failure to Yield": Essays

Description: Failure to Yield is a collection of creative nonfiction that explores themes of presence and emotional connection and expression. The seven essays, which include three flash essays, explore the themes by reflecting on such topics as marriage, parent-child relationships and addiction. The collection is woven together by the author's relationships with her parents and children and by her experiences growing up in a small town in Iowa.
Access: This item is restricted to UNT Community Members. Login required if off-campus.
Date: December 2017
Creator: Siegfried, Cary Ann

Catalysts of Women's Success in Academic STEM: A Feminist Poststructural Analysis

Description: This study analyzes senior women faculty's discourses about personal and professional experiences they believe contributed to their advancement in academic careers in science, technology, engineering, and mathematics (STEM). The purpose of the study is to understand factors that activate women's success in STEM disciplines where women's representation has not yet attained critical mass. A poststructuralist emphasis on complexity and changing nature of power relations offers a framework that illuminates the ways in which elite women navigate social inequalities, hierarchies of power, and non-democratic practices. Feminist poststructural discourse analysis (FPDA) methods allow analysis of women's talk about their experiences in order to understand the women's complex, shifting positions. Eight female tenured full professors of STEM at research-focused universities in the United States participated in the study. Data sources were in-depth semi-structured interviews, a demographic survey, and curricula vitae. Findings will help shape programs and policies aimed at increasing female representation and promoting achievement at senior levels in academic STEM fields.
Date: December 2017
Creator: Mullet, Dianna Rose

The Impact of True Fit Technology on Millennial Consumer Confidence and Satisfaction in their Online Clothing Purchase

Description: This study examines the use of True Fit® technology by millennial consumers and its impact on consumer confidence and satisfaction with respect to online sizing. In the apparel industry, there is a lack of size standards among retailers, and as a result consumers will encounter frequent size variations in their clothing size. Difference sizing technology has been developed to address the sizing issue. One is True Fit® which unlike other sizing technologies, uses mathematical algorithms to compile large amounts of data from designers. The purpose of this study was to analyze consumer confidence and satisfaction after True Fit® has been used to make a sizing decision while online shopping. The technology acceptance model (TAM) was used as the basis for the theoretical framework for this study. TAM explores how current advances in technology are influencing consumers' behaviors and attitudes. The variables studies included perceived ease of use, perceived usefulness, attitude, intent to use True Fit®, confidence and satisfaction. The methodology used in the study is a quantitative method consisting of an online survey and a True Fit® task, where consumers were exposed to True Fit® prior to answering questions about the use of sizing technology. The results of the study suggest the dependent variable of confidence and satisfaction with the sizing technology was positively affected by the intent to use True Fit®. Thus, it can be inferred that consumers felt positively about adopting apparel size technology and that technology such as this would have wide application in the future.
Date: December 2017
Creator: Parr, Jacqueline Nicole

Rediscovering James Robert Gillette's "Vistas"

Description: James Robert Gillette (1886-1963) was an early advocate for original wind band music at a time when marches and band transcriptions of orchestral music contributed heavily to the wind band repertoire. Primarily known as an influential, in-demand organist and composer, Gillette became the director of the Carleton College band program in Northfield, Minnesota in 1924. Taking an innovative approach to building, organizing, and programming, Gillette transformed that group into the Carleton Symphony Band and led a wider push for the symphonic band movement. In promoting his ideals of the symphonic band, he composed and arranged music specifically for the Carleton Symphony Band. One of his original works, Vistas, was widely performed and well-received in the decade just prior to and after its publication in 1934. Despite the popularity of the piece at that time, it has since gone out of print and is a rarely performed piece from Gillette's repertoire. This dissertation focuses on Vistas, Gillette's second published tone poem. This study starts with the examination of the history of Vistas from its origins as a movement in Gillette's transcription of Paul Robert Fauchet's Symphony in B-flat to its subsequent transformation and publication as an original work for band. Next, the performance history and reception of Vistas in the United States is traced and described from the year of publication to the present day. Finally, discrepancies present in the 1934 publication of Vistas are addressed through the creation of a performance edition. This performance edition also provides modifications to make the piece more widely accessible to wind bands today and the full score is presented at the end of the study.
Date: December 2017
Creator: Kitelinger, Jennifer Joy

Considerations for Global Development and Impact using Haiti as a Case Study

Description: As the world becomes more connected, issues surrounding sustainable development are coming to the fore of global discussions. This is exemplified in strategies such as the United Nation's Sustainable Development Goals (SDGs), released in 2015, which created a framework for global development that defines specific goals for issues like poverty, climate change, and social justice. To complement the analysis that went into defining the SDGs, capital allocations around the world are becoming more impact focused so that the paradigm of development is shifting from donations to impact investments. The push for impact, however, has led to a homogenization of global challenges like reproductive health and poverty. This, in turn, has led to a standardization of information resulting in agencies designing interventions based on data and information that is misguided because of incorrect assumptions about a specific context. This paper explores how the decision-making mechanisms of global development agencies and investors could apply more anthropological processes to mitigate negative impact. As the development sector becomes more and more standardized, anthropologists can act as translators between affected communities and the institutions deciding how best to help them.
Date: December 2017
Creator: Clerie, Isabelle

Corbicula fluminea Invasion as a Secondary Effect of Hydrilla verticillata Management via Triploid Grass Carp (Ctenopharyngodon idella)

Description: A study of Asian clam (Corbicula fluminea Müller) colonization in relation to changes in aquatic vegetation community as a result of management of Hydrilla verticillata (L. f.) Royle with grass carp was conducted at the Lewisville Aquatic Ecosystem Research Facility (LAERF), Lewisville, TX, from April 2015 through October 2016. Percent vegetation cover, C. fluminea abundance and water quality metrics (pH, turbidity, conductivity, DO, calcium, chlorophyll a) from 16 experimental subjects were analyzed. Treatments included four replicated grass carp stocking densities; 1-control with no fish stocked (n = 4), 2-low density of 40-43 fish per vegetated ha (n = 4), 3-medium density of 72-81 fish per vegetated ha (n = 4) and 4-high density of 110-129 fish per vegetated ha (n = 4). Data analysis showed statistical significance in the relation of C. fluminea abundance to percent vegetation cover (multiple linear regression, r2 = 0.820), grass carp stocking densities (two-way analysis of variance, p = <0.001) and chlorophyll a (multiple linear regression, r2 = 0.339). Findings of this research indicate the possibility that management of hydrilla had enabled establishment of secondary invasive species.
Date: December 2017
Creator: Holbrook, David Lee

Solo Violin in Gustav Mahler's Symphonic Works as a Musical Sign

Description: Noted for both vocal and symphonic output, Gustav Mahler's musical sophistication constantly puzzled scholars in the past decades. In his symphonic works, the mixed forms and styles in combination with the vocal influence make it abstruse for listeners to detect the meaning of the use of traditional instruments. The solo violin, which has an extensive history of appearing in symphonic compositions since the Baroque era, is an instance of a traditional instrument given an unusual function. For instance, Mahler's violin solos do not tend to showcase the virtuosity of the instrument as they normally do in orchestral music. In order to closely examine the role of the solo violin, I rely on aspects relating to introversive semiosis such as harmonies, rhythms, textures, phrase structures, and forms; then my focus shifts to extroversive semiosis, specifically to topics and contextual factors. By considering the violin as a musical sign, listeners can comprehend the instrument's structure, syntax, and ultimately the complex logic of Mahler's musical discourse.
Date: December 2017
Creator: Yang, Qiyao

Children with Emotional and Behavioral Disorders in Saudi Arabia: A Preliminary Prevalence Screening

Description: Education in Saudi Arabia, including the education of children with special needs, is developing rapidly. However, children with emotional and behavioral disorders are neither consistently identified nor adequately served in Saudi Arabia although they are recognized as a distinct category of children who require special education services. The goal of this study was to examine the prevalence of emotional and behavioral disorders among children in Saudi Arabia to assess the need for intervention services to help those children reach their potential. The current research identified the types of behaviors that are most evident in the study sample. Also, the relationship between demographics and emotional and behavioral disorders is studied to identify possible predictors of disruptive forms of behavior. Parents of children aged 4-17 years in Saudi Arabia were surveyed using the Strengths and Difficulties Questionnaire. The findings of the study suggest that children with emotional and behavioral disorders in Saudi Arabia may account for 20% of the population of children between the ages of 4 and 17. The findings also revealed that over 20% of children in Saudi Arabia have difficulties in peer relationship and lack the necessary prosocial behaviors. The parent reporting, child gender, child education type, the geographical region, the father's education level, and the family's socioeconomic status were found to be statistically significant predictors of children's difficulties. However, these predictors were only able to explain a small portion of the difficulty scores.
Access: This item is restricted to UNT Community Members. Login required if off-campus.
Date: December 2017
Creator: Maajeeny, Hassan

Homologs of Mammalian Lysosomal Lipase in Arabidopsis and Their Roles in Lipid Droplet Dynamics

Description: Lipid droplets (LDs) are organelles with many functions in cells and numerous protein interactors facilitate their biogenesis, maintenance, and turnover. The mammalian lipase responsible for LD turnover during lipophagy, LipA, has two candidate homologs in Arabidopsis: MPL1 and LIP1. One or both of these plant homologs may function in a similar manner to mammalian LipA, providing an LD breakdown pathway. To test this hypothesis, wild type (WT) Arabidopsis plants, MPL1 over-expressing (OE) mutants, and T-DNA insertion mutants of MPL1 (mpl1) and LIP1 (lip1) were examined for LD phenotypes in normal conditions and in environments where LD numbers are known to fluctuate. Plants to be imaged by confocal microscopy were exposed to heat stress and wounding to increase LD accumulation, senescence was induced in leaves to deplete lipids, and LDs were imaged throughout the day/night period to observe their diurnal regulation. The mutation of both MPL1 and LIP1 lead to an increase in LDs within the leaf mesophyll cells, although the spatial distribution of the LDs differed between the two mutants. mpl1 mutants had disrupted diurnal regulation of their LDs, but lip1 mutants did not. Alternately, lip1 mutants retained LDs during dark-induced senescence, and mpl1 mutants did not. Together these results suggest that MPL1 and LIP1 are likely both important for LD dynamics; however they appear have roles in different aspects of LD accumulation and turnover.
Access: This item is restricted to UNT Community Members. Login required if off-campus.
Date: December 2017
Creator: McClinchie, Elizabeth A

Arduino Based Hybrid MPPT Controller for Wind and Solar

Description: Renewable power systems are becoming more affordable and provide better options than fossil-fuel generation, for not only the environment, but a benefit of a reduced cost of operation. Methods to optimize charging batteries from renewable technologies is an important subject for off-grid and micro-grids, and is becoming more relevant for larger installations. Overcharging or undercharging the battery can result in failure and reduction of battery life. The Arduino hybrid MPPT controller takes the advantage of solar and wind energy sources by controlling two systems simultaneously. The ability to manage two systems with one controller is better for an overall production of energy, cost, and manageability, at a minor expense of efficiency. The hybrid MPPT uses two synchronous buck DC-DC converters to control both wind and solar. The hybrid MPPT performed at a maximum of 93.6% efficiency, while the individual controller operated at a maximum 97.1% efficiency when working on the bench test. When designing the controller to manage power production from a larger generator, the inductor size was too large due to the frequency provided by the Arduino. A larger inductor means less allowable current to flow before the inductor becomes over saturated, reducing the efficiency of the controller. Utilizing a different microcontroller like the PIC16C63A produces a much faster frequency, which will reduce the inductor size needed and allow more current before over saturation.
Date: December 2017
Creator: Assaad, Michael

The Effects of Multicultural Discussions and Supervisory Working Alliance on Multicultural Counseling Competence

Description: This study examined the influence of multicultural training, multicultural discussions in supervision, and the supervisory working alliance on multicultural counseling competence. The sample consisted of 57 doctoral counseling interns, doctoral graduate students and post-doctoral students in counseling and clinical psychology. Participants completed several instruments including a demographic questionnaire, the Supervisory Working Alliance Inventory - Trainee, and the Multicultural Counseling Inventory. They filled out two questionnaires created for this study, one assessing multicultural discussions in supervision and another quantifying their multicultural training experience. Data analyses included multiple hierarchical regression, utilizing the Hayes PROCESS macro. Multicultural discussions in supervision moderated the relationship between the supervisory working alliance and multicultural counseling competence, but did not significantly moderate the relationship between multicultural training and multicultural counseling competence. Findings suggest that when multicultural discussions in supervision are positive, they significantly increases the strength of the relationship between good supervisory working alliance and multicultural counseling competence in psychology trainees. The findings may inform supervision practices and improve multicultural counseling competence in psychology graduate student trainees.
Date: December 2017
Creator: Carr, Jarice N

Postmodern Multiplicities in Three Original Works

Description: My recent compositions are situated within a postmodern theoretical framework. The heterogeneity of materials and hybridity of musical formation in these works are interpreted and contextualized within a personal reading of postmodern theories. The critical essay traces my aesthetics through a historical investigation into the definition of musical postmodernism. Through extensive citation and analysis of the writings of Julius T. Fraser, Italo Calvino, and Richard Rorty, the essay aims to provide a theoretical context for the interpretation of the musical examples. The creative documentation contains three newly-composed musical works: Piano Trio from Opus 3/c, Opus 6 for Violin, and Opus 7 for Piccolo. The works' postmodern features include creative approaches to the fragmentation of musical time into separate levels, historical allusions, and the exploration of multiplicity.
Access: This item is restricted to UNT Community Members. Login required if off-campus.
Date: December 2017
Creator: Bejo, Ermir

Nathanael Greene and the Myth of the Valiant Few

Description: Nathan Greene is the Revolutionary Warfare general most associated with unconventional warfare. The historiography of the southern campaign of the revolution uniformly agrees he was a guerrilla leader. Best evidence shows, however, that Nathanael Greene was completely conventional -- that his strategy, operations, tactics, and logistics all strongly resembled that of Washington in the northern theater and of the British commanders against whom he fought in the south. By establishing that Greene was within the mainstream of eighteenth-century military science this dissertation also challenges the prevailing historiography of the American Revolution in general, especially its military aspects. The historiography overwhelmingly argues the myth of the valiant few -- the notion that a minority of colonists persuaded an apathetic majority to follow them in overthrowing the royal government, eking out an improbable victory. Broad and thorough research indicates the Patriot faction in the American Revolution was a clear majority not only throughout the colonies but in each individual colony. Far from the miraculous victory current historiography postulates, American independence was based on the most prosaic of principles -- manpower advantage.
Date: December 2017
Creator: Smith, David R.

Psychopathy in Male and Female Offenders: Validating the CAPP-IRS and Investigating the Impact of Gender Role Conformity

Description: Recent conceptualizations of psychopathy are moving toward more inclusive, purely trait-based models. However, researchers continue to heavily rely on assessments of psychopathy that include categorical behavioral elements. The newly developed Comprehensive Assessment of Psychopathic Personality – Institutional Rating Scale appears to be a promising interview-based measure of psychopathy, but research on its reliability and validity is in its infancy. As a second issue, the vast majority of research on psychopathy, particularly in offender populations, is conducted with male participants. Nonetheless, the growing body of literature involving incarcerated females suggests gender differences in the prevalence and manifestation of psychopathic traits. Reasons for these differences are unclear, but some have proposed socialized gender roles as a contributing factor. With a sample of 52 female 49 male offenders recruited from a large, metropolitan jail, this dissertation evaluated the construct validity of the CAPP-IRS and examined the effect of gender role conformity on the manifestation of psychopathic traits. Results indicated that a three-factor model of psychopathy represented by antagonistic interpersonal relations, restricted emotions, and disinhibited behavior best fit the data. Findings further suggested convergent and discriminant validity for the CAPP-IRS. Additionally, masculine and feminine gender role conformity differentially related to psychopathy, but generally accounted for a small proportion of the variance in psychopathic traits. Recommendations for future research on the CAPP model and its assessment as well as implications for the clinical assessment of psychopathy in women are discussed.
Access: This item is restricted to UNT Community Members. Login required if off-campus.
Date: December 2017
Creator: Carter, Rachel Marjann

How Does It Feel to be Creative?

Description: How does it feel to be creative? Such a question, when approached from a phenomenological perspective, reveals new understandings about the embodied experience of creativity, and how it feels as it is being lived. This investigation begins with a provocative contrast of two environments where creativity is thought to manifest itself: school art classrooms, where creativity is often legislated from an authority figure, and New Orleans Second Line parades, where creativity is organically and kinetically expressed. A thorough review of the literature on creativity focuses on education, arts education, creative economies, psychology, and critical theorists, collectively revealing a cognitive bias and striking lack of consideration for community, freedom, and the lived experience of being creative. Further discussions in the literature also neglect sites of creativity, and the impact that place (such as a school classroom) can have upon creativity. The phenomenological perspectives of Merleau-Ponty, Heidegger, Bachelard, and Trigg support a methodological lens to grasp embodied knowledge, perceptions of placedness on creativity, and the interdependent frictions between freedom, authenticity, movement and belonging. The research method includes investigations in New Orleans in archives, examination of visual and material culture, participation in cultural practice, and formal and informal interviews. Further, the phenomena of walking and wandering became a methodology for embodied data collection that clarified the emerging rich experiences and descriptions of how it feels to be creative, especially how it feels to be creative in a creative place. What is also revealed are intense frictions, such as the tension between perceptions of personal freedom and a high demand for authenticity in terms of New Orleans traditions, that opens the space and fuels the inspiration for the abundance of creativity found in New Orleans culture.
Date: December 2017
Creator: Bartholomee, Lucy

Facets of Positive Affect and Risk for Bipolar Disorder: Role of the Behavioral Activation System

Description: Bipolar disorder is characterized by disruptions in mood and affect that occur not only during mood episodes, but during euthymic periods as well. At the same time, sensitivity of the behavioral activation system (BAS) has been implicated in the disorder and is a risk marker for it. Less clear is the relationship between BAS sensitivity and positive affect, particularly lower level facets of positive affect. The aim of the present study was to examine the relationship between positive affect and vulnerability for mania as assessed using BAS sensitivity. Specifically, the link between daily levels and fluctuations of positive affect and baseline BAS sensitivity was examined. Following the hierarchical model of affect, this study also assessed the relationship between BAS sensitivity and the distinct facets of positive affect. Finally, this study examined whether BAS sensitivity moderates associations between daily rewards and positive affect. Undergraduates (N = 265) from a large university in the South were recruited to complete measures of BAS sensitivity, affect, and mood symptoms at baseline. Using ecological momentary assessment (EMA), participants completed daily surveys assessing affect and engagement with rewarding situations. An exploratory factory analysis revealed a four factor structure of positive affect, consisting of Serenity, Joviality, Attentiveness, and Self-Assurance. Greater daily levels of overall positive affect, as well as the lower order facets of Joviality, Self-Assurance, and Attentiveness, were predicted by heightened BAS sensitivity. In contrast, the facet of Serenity demonstrated minimal associations with BAS sensitivity. The study findings support a multi-faceted structure of positive affect and suggest that certain facets may be more closely related to risk for bipolar disorder. Specifically, Joviality and Self-Assurance may represent maladaptive forms of positive affect, whereas Serenity may function as a protective element against bipolar disorder.
Access: This item is restricted to UNT Community Members. Login required if off-campus.
Date: December 2017
Creator: Dornbach-Bender, Allison

Modeling of High Strain Rate Compression of Austenitic Shape Memory Alloys

Description: Shape memory alloys (SMAs) exhibit the ability to absorb large dynamic loads and, therefore, are excellent candidates for structural components where impact loading is expected. Compared to the large amount of research on the shape memory effect and/or pseudoelasticity of polycrystalline SMAs under quasi-static loading conditions, studies on dynamic loading are limited. Experimental research shows an apparent difference between the quasi-static and high strain rate deformation of SMAs. Research reveals that the martensitic phase transformation is strain rate sensitive. The mechanism for the martensitic phase transformation in SMAs during high strain rate deformation is still unclear. Many of the existing high strain rate models assume that the latent heat generated during deformation contributes to the change in the stress-strain behavior during dynamic loading, which is insufficient to explain the large stress observed during phase transformation under high strain rate deformation. Meanwhile, the relationship between the phase front velocity and strain rate has been studied. In this dissertation, a new resistance to phase transformation during high strain rate deformation is discussed and the relationship between the driving force for phase transformation and phase front velocity is established. With consideration of the newly defined resistance to phase transformation, a new model for phase transformation of SMAs during high strain rate deformation is presented and validated based on experimental results from an austenitic NiTi SMA. Stress, strain, and martensitic volume fraction distribution during high strain rate deformation are simulated using finite element analysis software ABAQUS/standard. For the first time, this dissertation presents a theoretical study of the microscopic band structure during high strain rate compressive deformation. The microscopic transformation band is generated by the phase front and leads to minor fluctuations in sample deformation. The strain rate effect on phase transformation is studied using the model. Both the starting stress for transformation and ...
Date: December 2017
Creator: Yu, Hao

Trends in Special Education Due Process Hearings in Texas from 2010-2015: School, Parent, and Social Justice Issues that Inform a Principal's Decision-Making

Description: This study explores all due process hearings that occurred in Texas public school districts from 2010-2015. Special attention was paid to the reasons for the hearings within the legal reports addressed and their outcomes. The study was conducted using a quantitative approach involving a legal document content analysis of due process hearings to select the participants to be interviewed with a qualitative semi-structured interview protocol. Following this process, nine participants from one district were interviewed. Responses were then analyzed for themes and patterns using qualitative methods, and conclusions were drawn based on the data. The study found that campus and central office administrators believed socio-economic levels, lack of empathy shown to parents, and distrust contributed to parents' decisions to file due process complaints or litigation. They also believed that placement decisions influenced by student discipline, parent denial about the impact of the disability on children, and parent entitlement played a role. Lastly, the nine participants found that parent advocacy and communication were strong contributors to the amount of due process hearings held at Evergreen ISD.
Date: December 2017
Creator: Poton, Marcy Rose

Design of Bioinspired Conductive Smart Textile

Description: Electrically conductive fabrics are one of the major components of smart textile that attracts a lot of attention by the energy, medical, sports and military industry. The principal contributors to the conductivity of the smart textiles are the intrinsic properties of the fiber, functionalization by the addition of conductive particles and the architecture of fibers. In this study, intrinsic properties of non-woven carbon fabric derived from a novel linear lignin, poly-(caffeyl alcohol) (PCFA) discovered in the seeds of the vanilla orchid (Vanilla planifolia) was investigated. In contrast to all known lignins which comprise of polyaromatic networks, the PCFA lignin is a linear polymer. The non-woven fabric was prepared using electrospinning technique, which follows by stabilization and carbonization steps. Results from Raman spectroscopy indicate higher graphitic structure for PCFA carbon as compared to the Kraft lignin, as seen from G/D ratios of 1.92 vs 1.15 which was supported by a high percentage of graphitic (C-C) bond observed from X-ray photoelectron spectroscopy (XPS). Moreover, from the XRD and TEM a larger crystal size (Lc=12.2 nm) for the PCFA fiber was obtained which correlates to the higher modulus and conductivity of the fiber. These plant-sourced carbon fabrics have a valuable impact on zero carbon footprint materials. In order to improve the strength and flexibility of the non-woven carbon fabric, lignin was blended with the synthetic polymer Poly acrylonitrile (PAN) in different concertation, resulting in electrical conductivity up to (7.7 S/cm) on blend composition which is enough for sensing and EMI shielding applications. Next, the design of experiments approach was used to identify the contribution of the carbonization parameters on the conductivity of the fabrics and architecture of the fibers, results show carbonization temperature as the major contributing factor to the conductivity of non-woven fabric. Finally, a manufacturing procedure was develop inspired by the ...
Access: This item is restricted to UNT Community Members. Login required if off-campus.
Date: August 2017
Creator: Rizvi, Syed Hussain Raza

The Influence of Disease Mapping Methods on Spatial Patterns and Neighborhood Characteristics for Health Risk

Description: This thesis addresses three interrelated challenges of disease mapping and contributes a new approach for improving visualization of disease burdens to enhance disease surveillance systems. First, it determines an appropriate threshold choice (smoothing parameter) for the adaptive kernel density estimation (KDE) in disease mapping. The results show that the appropriate threshold value depends on the characteristics of data, and bandwidth selector algorithms can be used to guide such decisions about mapping parameters. Similar approaches are recommended for map-makers who are faced with decisions about choosing threshold values for their own data. This can facilitate threshold selection. Second, the study evaluates the relative performance of the adaptive KDE and spatial empirical Bayes for disease mapping. The results reveal that while the estimated rates at the state level computed from both methods are identical, those at the zip code level are slightly different. These findings indicate that using either the adaptive KDE or spatial empirical Bayes method to map disease in urban areas may provide identical rate estimates, but caution is necessary when mapping diseases in non-urban (sparsely populated) areas. This study contributes insights on the relative performance in terms of accuracy of visual representation and associated limitations. Lastly, the study contributes a new approach for delimiting spatial units of disease risk using straightforward statistical and spatial methods and social determinants of health. The results show that the neighborhood risk map not only helps in geographically targeting where but also in tailoring interventions in those areas to those high risk populations. Moreover, when health data is limited, the neighborhood risk map alone is adequate for identifying where and which populations are at risk. These findings will benefit public health tasks of planning and targeting appropriate intervention even in areas with limited and poor-quality health data. This study not only fills the identified ...
Date: December 2017
Creator: Ruckthongsook, Warangkana