UNT Theses and Dissertations - 403 Matching Results

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Design, Synthesis and Screening of Homoleptic and Heteroleptic Platinum(ii) Pyridylazolate Complexes for N-type Semiconducting and Light-emitting Devices

Description: A series of heteroleptic and homoleptic platinum(II) complexes has been synthesized and characterized towards their use in thin film devices such as organic light-emitting diodes (OLEDs) and organic thin film transistors (OTFTs). Pyridylpyrazolate- and pyridyltetrazolate-containing ligands were selected due to their structural rigidity and ease of functionalization. Single-crystal x-ray diffraction studies of two selected heteroleptic complexes show strong aggregation with preferential stacking into vertical columns with a varying degree of overlap of the neighboring square planar molecular units. It is shown that the close proximity of the molecules to one another in the stack increases semiconducting character, phosphorescence quantum yields, and shorter radiative lifetimes. The potential for these materials towards incorporation into high-efficiency doping free white OLEDs (DFW-OLEDs) for solid-state lighting and display applications has been realized and will be expanded upon by present and future embodiments of materials in this thesis.
Date: August 2012
Creator: Oswald, Iain William Herbert
Partner: UNT Libraries

Southern Roots, Western Foundations: the Peculiar Institution and the Livestock Industry on the Northwestern Frontier of Texas, 1846-1864

Description: This dissertation challenges Charles W. Ramsdell's needless war theory, which argued that profitable slavery would not have existed west of the 98th meridian and that slavery would have died a natural death. It uses statistical information that is mined from the county tax records to show how slave-owners on the northwestern frontier of Texas raised livestock rather than market crops, before and during the Civil War. This enterprise was so strong that it not only continued to expand throughout this period, but it also became the foundation for the recovery of the Texas economy after the war.
Date: August 2012
Creator: Liles, Deborah Marie
Partner: UNT Libraries

The Useful Arts

Description: This creative nonfiction dissertation is a series of braided narratives that chronicle the author's career as a trombonist in the John Smith Ensemble. As an amateur trombonist, the author is shocked to be hired as a professional musician for an orchestra that plays on PBS and at Carnegie Hall. She quickly realizes, however, that the job requires her to play the trombone quietly in front of an unplugged microphone while a CD recording of another, more talented trombonist is blasted out toward an unknowing audience. The job also requires the author to tour around America. The scenes of from this tour are braided with scenes wherein she reflects on her life as a professional fake musician and her past failed attempts at getting a job.
Date: August 2012
Creator: Hindman, Jessica
Partner: UNT Libraries

Between Comancheros and Comanchería: a History of Fort Bascom, New Mexico

Description: In 1863, Fort Bascom was built along the Canadian River in the Eroded Plains of Territorial New Mexico. Its unique location placed it between the Comanches of Texas and the Comancheros of the Sangre de Cristo Mountains. This post was situated within Comanchería during the height of the United States Army's war against the Southern Plains Indians, yet it has garnered little attention. This study broadens the scholarly understanding of how the United States Army gained control of the Southwest by examining the role Fort Bascom played in this mission. This includes an exploration of the Canadian River Valley environment, an examination of the economic relationship that existed between the Southern Plains Indians and the mountain people of New Mexico, and an account of the daily life of soldiers posted to Fort Bascom. This dissertation thus provides an environmental and cultural history of the Canadian River Valley in New Mexico, a social history of the men stationed at Fort Bascom, and proof that the post played a key role in the Army's efforts to gain control of the Southern Plains Indians. This study argues that Fort Bascom should be recognized as Texas' northern-most frontier fort. Its men were closer to the Comanche homeland than any Texas post of the period. Its records clearly show that the Army used Fort Bascom as a key forward base of operations against Comanches and Kiowas. An examination of Bascom's post returns, daily patrols, and major expeditions allows its history to provide a useful perspective on the nineteenth-century American Southwest.
Date: August 2012
Creator: Blackshear, James Bailey
Partner: UNT Libraries

Challenge the Silence

Description: This collection of personal essays about incest, abuse, and depression explores the lasting effects of an invisible childhood. The essays follow the protagonist from the age of five to her early twenties. Her brother, at a young age, becomes sexually abusive of her and her sisters, and her parents fail to protect their daughters. The family is divided as the older girls strive to defend their little sisters, while their parents attempt to excuse their son. When her brother is finally sent away, the protagonist is left to salvage what remains of her relationships with her parents.
Date: August 2012
Creator: Peterson, Erica
Partner: UNT Libraries

The Enemy of My Enemy Is What, Exactly? the British Flanders Expedition of 1793 and Coalition Diplomacy

Description: The British entered the War of the First Coalition against Revolutionary France in 1793 diplomatically isolated and militarily unprepared for a major war. Nonetheless, a French attack on the Dutch Republic in February 1793 forced the British to dispatch a small expeditionary force to defend their ally. Throughout the Flanders campaign of 1793, the British expeditionary force served London as a tool to end British isolation and enlist Austrian commitment to securing British war objectives. The 1793 Flanders campaign and the Allied war effort in general have received little attention from historians, and they generally receive dismissive condemnation in general histories of the French Revolutionary Wars. This thesis examines the British participation in the 1793 Flanders campaign a broader diplomatic context through the published correspondence of relevant Allied military and political leaders. Traditional accounts of this campaign present a narrative of defeat and condemn the Allies for their failure to achieve in 1793 the accomplishments of the sixth coalition twenty years later. Such a perspective obscures a clear understanding of the reasons for Allied actions. This thesis seeks to correct this distortion by critically analyzing the relationship between British diplomacy within the Coalition and operations in Flanders. Unable to achieve victory on their own strength, the British used their expeditionary force in Flanders as diplomatic leverage to impose their objectives on the other powers at war with France.
Date: August 2012
Creator: Jarrett, Nathaniel W.
Partner: UNT Libraries

José Antonio Gómez´s Versos Para Órgano (Section I): a Practical Guide for Performance

Description: José Antonio Gómez is an important figure in Mexican music history and his works are considered representative of the beginning of Mexico´s Independent era. Some musicians are familiar with Gómez´s choral output but his organ music is rarely considered. Due to the lack of an edition of Gómez´s Versets for Organ, a practical guide was found needed to aid its performance. This study is based on performance, analysis, and direct work on the only known source for it. The first chapter, Introduction, presents the argument for an edited version of the first part of the manuscript as a performance guide. The second provides biographical information on the composer. The third chapter discusses the background for the original performance of the Versets for Organ. Chapter 4 provides performance considerations for the works. The edition of the manuscript is included in chapter 5.
Date: August 2012
Creator: Carrasco Curíntzita, Laura A.
Partner: UNT Libraries

The Sex Offender Registry in Collin County, Texas: a Descriptive Analysis of Sex Offenders

Description: The primary goal of this study was to analyze the characteristics of current registered sex offenders in Collin County, Texas, as well as to compare age and gender of the victims of these offenders in order to know who sex offenders primarily target in these crimes. The study also sought to discover geographic patterns of where the registered sex offenders reside for the purpose of keeping communities aware. Participants consisted of 175 registered sex offenders (N = 175) in Collin County, Texas, found on Collin County's and the Texas Department of Public Safety's online public registries. The findings demonstrate that there were significant trends among the sex offenders, their victims, location of residence, and housing complications as a result of progressing sex offender laws. Treatment programs and the reintegration of offenders in the community were also addressed. The meaning of the results in this study can aid in the development of safety and prevention strategies, provide an understanding about the utilization of sex offender registries, and can benefit law enforcement to predict the movement of current sex offenders, along with knowing where to find other potential offenders.
Date: December 2012
Creator: Valenzuela, Priscilla
Partner: UNT Libraries

Criticality in Cooperative Systems

Description: Cooperative behavior arises from the interactions of single units that globally produce a complex dynamics in which the system acts as a whole. As an archetype I refer to a flock of birds. As a result of cooperation the whole flock gets special abilities that the single individuals would not have if they were alone. This research work led to the discovery that the function of a flock, and more in general, that of cooperative systems, surprisingly rests on the occurrence of organizational collapses. In this study, I used cooperative systems based on self-propelled particle models (the flock models) which have been proved to be virtually equivalent to sociological network models mimicking the decision making processes (the decision making model). The critical region is an intermediate condition between a highly disordered state and a strong ordered one. At criticality the waiting times distribution density between two consecutive collapses shows an inverse power law form with an anomalous statistical behavior. The scientific evidences are based on measures of information theory, correlation in time and space, and fluctuation statistical analysis. In order to prove the benefit for a system to live at criticality, I made a flock system interact with another similar system, and then observe the information transmission for different disturbance values. I proved that at criticality the transfer of information gets the maximal efficiency. As last step, the flock model has been shown that, despite its simplicity, is sufficiently a realistic model as proved via the use of 3D simulations and computer animations.
Date: May 2012
Creator: Vanni, Fabio
Partner: UNT Libraries

Predictors of Quality of Life (Qol): Comparing Baby Boomers, Older Adults, and Younger Adults Using Data From the 2010 National Health Interview Survey

Description: The purpose of this study was to identify factors that predict quality of life (QOL) for aging adults and to examine and compare Baby Boomers', Older Adults' and Younger Adults' responses to the 2010 National Health Interview Survey/QOL Functioning and Disability. Significant findings included several significant values based on the multivariate regression to estimate a model to predict QOL. In particular, being male, four ethnicities other than white, being older than Boomer, age in 10 years, the Functional Difficulty Index, the Functional Limitation Index scores, chronic heart disease, asthma, and arthritis all had significant p values. Adults with chronic heart disease, asthma, or arthritis scored lower on the QOL index, but cancer, stroke, or diabetes were not associated with the QOL index. Two hypotheses had strong support. Lower scores on both the Functional Difficulty Index and the Functional Limitation Index yielded lower QOL scores. Further research recommendations include establishing reliability and validity of the QOL index; running additional regressions for demographics (ethnicity, marital status, etc.) to predict possible combinations of variables predicting QOL or barriers to QOL; and investigating the viability of incorporating the QOL index into an electronic medical record (EMR) dashboard parameter to serve as a screening mechanism for those aging adults most at risk for chronicities or co-morbidities that place them at risk for losing their ability to age in place in the home of their choosing.
Date: December 2012
Creator: Bryce, Helen Roult
Partner: UNT Libraries

Development of a Laponite Pluronic Composite for Foaming Applications

Description: The focus of the following research was to provide an optimized particle stabilized foam of Laponite and Pluronic L62 in water by understanding (1) the Laponite-Pluronic interactions and properties for improved performance in a particle stabilized foam and (2) the interfacial properties between air and the Laponite-Pluronic complex. These studies were conducted using both bulk and interfacial rheology, XRD, sessile droplet, TGA and UV-vis. Two novel and simple techniques, lamella break point and capillary breakup extensional rheometry, were used to both understand the Laponite Pluronic L62 interaction and determine a different mechanism for foaming properties. Bulk rheological properties identified an optimal Laponite concentration of 2% with Pluronic L62 ranging from 2.5% and 6.5%, due to the ease of flow for the dispersion. The Pluronic L62 was observed to enhance the Laponite bulk rheological properties in solution. Additionally TGA showed a similar trend in thermal resistance to water with both addition of Laponite and Pluronic L62. XRD demonstrated that 0.25% Pluronic intercalated into Laponite from dried 2% Laponite films. XRD demonstrated that the Laponite matrix was saturated at 1% Pluronic L62. UV-vis demonstrated that a monolayer of Pluronic L62 is observed up to 0.65% Pluronic L62 onto Laponite. Interfacial rheology showed that Laponite enhances Pluronic L62 at the air-liquid interface by improving the storage modulus as low at 0.65% Pluronic L62 with 2% Laponite. The lamella breakpoint of Laponite with Pluronic films indicate strong film interaction due to higher increases in mass. Extensional rheology indicates that 2.5% to 6.5% Pluronic with 2% Laponite show the most filament resistance to stretching.
Date: December 2012
Creator: Davis, James William
Partner: UNT Libraries

British Labour Government Policy in Iraq, 1945-1950

Description: Britain during the Labour government's administration took a major step toward developing Iraq primarily due to the decision of Ernest Bevin, the Foreign Minister, to start a new British policy toward the Iraqi regimes that would increase the British influence in the area. This led to Bevin's strategy of depending on guiding the Iraqi regime to make economic and political reforms that would lead to social justice.
Date: December 2012
Creator: Alburaas, Theyab
Partner: UNT Libraries

Leader Developmental Readiness of Generation Y in the Training Industry

Description: Members of Generation Y in the training and development industry will be required to assume leadership roles as Baby Boomers retire, yet little empirical research exists regarding how best to prepare them for leadership. The purpose of this study was to examine differences in leader developmental readiness between generational cohorts in the training industry, specifically Baby Boomers, Generation X, and Generation Y. Leader developmental readiness provided a definition of developmental readiness for leaders using the five constructs (learning goal orientation, developmental efficacy, self-awareness, leader complexity, and metacognitive ability). A volunteer sample was compiled from members of the ASTD National LinkedIN group (n = 636). Results were analyzed using structured means analysis with maximum likelihood (ML) estimation. Generational cohorts demonstrated differences in leader developmental readiness. Baby Boomers indicated statistically and practically higher metacognitive ability and developmental efficacy than Generation Y. Results demonstrated statistically and practically higher leader complexity in Generation Y and both Generation X and Baby Boomers. These results should inform leader development practitioners as they continue to use existing methods in preparing the different generations for leader development interventions while pointing to possible needs to increase the metacognitive ability and developmental efficacy in Generation Y and ensure accurate perception of leader complexity in those individuals. Further research would be helpful to confirm or refute findings and expand on the target population for enhanced generalizability.
Date: December 2012
Creator: Garrigue, Marie
Partner: UNT Libraries

Characterization of Arthrobacter Globiformis Aspartate Transcarbamylase Concentrations of Substrates

Description: This thesis consists of one major section with two subsections. The first subsection investigates the activity of Arthrobacter globiformis aspartate transcarbamylase's specific activity with increasing concentrations of the enzyme's substrate. Dihydroorotase (DHOase) activity was also measured with increasing concentrations of the substrate dihydroorotate. The second subsection collected data in order to classify the enzyme, resulting in a classification into the category of class A ATCases with bifunctional ATCase-DHOase complexes. The thesis provides evidence to broaden understanding of the ATCase and DHOase enzymes for members of the family that Arthrobacter belongs to.
Date: December 2012
Creator: Wright, Jackie
Partner: UNT Libraries

Real Analyticity of Hausdorff Dimension of Disconnected Julia Sets of Cubic Parabolic Polynomials

Description: Consider a family of cubic parabolic polynomials given by for non-zero complex parameters such that for each the polynomial is a parabolic polynomial, that is, the polynomial has a parabolic fixed point and the Julia set of , denoted by , does not contain any critical points of . We also assumed that for each , one finite critical point of the polynomial escapes to the super-attracting fixed point infinity. So, the Julia sets are disconnected. The concern about the family is that the members of this family are generally not even bi-Lipschitz conjugate on their Julia sets. We have proved that the parameter set is open and contains a deleted neighborhood of the origin 0. Our main result is that the Hausdorff dimension function defined by is real analytic. To prove this we have constructed a holomorphic family of holomorphic parabolic graph directed Markov systems whose limit sets coincide with the Julia sets of polynomials up to a countable set, and hence have the same Hausdorff dimension. Then we associate to this holomorphic family of holomorphic parabolic graph directed Markov systems an analytic family, call it , of conformal graph directed Markov systems with infinite number of edges in order to reduce the problem of real analyticity of Hausdorff dimension for the given family of polynomials to prove the corresponding statement for the family .
Date: August 2012
Creator: Akter, Hasina
Partner: UNT Libraries

Solid Lubrication Mechanisms in Laser Deposited Nickel-titanium-carbon Metal Matrix Composites

Description: A Ni/TiC/C metal matrix composite (MMC) has been processed using the laser engineered net shaping (LENS) process from commercially available powders with a Ni-3Ti-20C (atomic %) composition. This processing route produces the in-situ formation of homogeneously distributed eutectic and primary titanium carbide and graphite precipitates throughout the Ni matrix. The composite exhibits promising tribological properties when tested in dry sliding conditions with a low steady state coefficient of friction (CoF) of ~0.1 and lower wear rates in comparison to LENS deposited pure Ni. The as deposited and tribologically worn composite has been characterized using Auger electron spectroscopy, scanning electron microscopy (SEM), X-ray diffraction, high resolution transmission electron microscopy (HRTEM) with energy dispersive spectroscopy (EDS), dual beam focused ion beam SEM (FIB/SEM) serial sectioning and Vickers micro-hardness testing. The evolution of subsurface stress states and precipitate motion during repeated sliding contact has been investigated using finite element analysis (FEA). The results of FIB/SEM serial sectioning, HRTEM, and Auger electron spectroscopy in conjunction with FEA simulations reveal that the improved tribological behavior is due to the in-situ formation of a low interfacial shear strength amorphous carbon tribofilm that is extruded to the surface via refined Ni grain boundaries.
Date: December 2012
Creator: Mogonye, Jon-Erik
Partner: UNT Libraries

No-thought Shopping: Understanding and Controlling Nonconscious Processing in Marketing

Description: This dissertation explores how nonconscious thought processing might be affected and activated in ways that influence consumer decision making. To activate nonconscious thought processes, this dissertation relies on priming—the unobtrusive activation of mental representations by stimuli in a social context, which occurs without participants' conscious awareness. Three dimensions of consumer decision making are investigated: purchase intention, product evaluation and arousal. The dissertation is based on the auto-motive model of nonconscious goal pursuit and somatic marker hypothesis. The dissertation is driven by three experiments, which respectively explore crucial areas in priming effects and addresses the following research question: can primes be shaped or controlled by marketers? Specifically, the dissertation examines whether shopping behavior can be primed. Second, the dissertation also examines how facial primes displaying basic emotions (happiness, anger, contempt, disgust, fear, sadness, and surprise) can prime emotion and arousal. Finally the dissertation examines the effect of the interaction of the buying prime with the primes of faces displaying basic emotions on the dependent variables of purchase intention, product evaluation, emotion, and arousal. Results from three experimental studies show that shopping behavior can be primed, and primed participants will exhibit higher product evaluation than those exposed to a control prime. Second while exposing participants to primes of faces displaying emotions did not elicit those emotions, the priming with faces did reveal a marginal activation of arousal in the participants. Third priming with faces was not found to interact with primed buying behavior such that the interaction would affect the level of arousal. The results indicate that Bargh's auto-motive model of nonconscious goal pursuit can be applied to marketing. Thus priming shopping behavior can affect product evaluation though the effect of this prime appears to be too weak to be applied in the field. Priming with faces was found not to interact ...
Date: December 2012
Creator: Fabrize, Jr., Robert O.
Partner: UNT Libraries

Ecological Forms of Life: Wittgenstein and Ecolinguistics

Description: The present philosophical literature on philosopher Ludwig Wittgenstein tends to either stagnate by focusing upon issues particular to Wittgenstein's philosophy or expand the boundaries of Wittgenstein's thought to shed light onto other areas of study. One area that has largely been ignored is the realm of environmental philosophy. I prepare the way for a solution to this by first arguing that Wittgenstein's later philosophy of language shows 'proto-ecolinguistic' concerns, sharing much in common with the ecolinguistic thought of both Peter Mühlhäusler and Luisa Maffi. This reading, as well as the work of Mühlhäusler and Maffi, is a starting point for an opposition to a common trend in much of contemporary linguistics of adhering to a linguistic paradigm of universalizing linguistic atomism that gives an impoverished account of language. This impoverished account is argued to have potential environmental and ecological consequences which the universalizing atomistic paradigm is ill-equipped to address.
Date: December 2012
Creator: Sarratt, Nicholas M.
Partner: UNT Libraries

Student Facilitation and Predictors of Engagement in Peer-Led Literature Circle Discussions

Description: The purpose of this research was to examine the relation between students' personality traits and the extent of their engagement and facilitation in peer-led literature circle discussions. The research was guided by two questions. To what extent do reading ability, gender, and personality traits predict the quality of verbal engagement in literature circles? and How do highly engaged participants facilitate discussion in the circles? The researcher video-taped 17 fourth-grade students' literature circle discussions for a total of 136.7 minutes collected on two separate occasions across two weeks. To answer the first question student contributions in discussions were quantified into a measure of quality of verbal engagement score (cf. Costa & Kallick, 2000). This quality of verbal engagement score served as the dependent variable in a multiple regression. The seven independent variables were (1) extroversion, (2) agreeableness, (3) conscientiousness, (4) emotional stability, (5) openness, (6) reading ability, and (7) gender. The quantitative analysis in this study revealed that emotional stability was the only significant variable that predicted higher quality of verbal engagement. A post hoc analysis that included group size as an additional variable revealed that groups composed of three members correlated with higher overall quality of verbal engagement. The second question was answered through a qualitative analysis of the following: exploratory talk, elaborative feedback, topic management, confessionals, and accountability. Results of this analysis suggest that highly engaged students frequently enhance the group discussions through facilitation. This study extended the extant research by investigating individual factors that may influence the quality of literature circle discussions as well as suggested a framework for understanding facilitation in peer-led literature circle discussions. Further research is needed to determine the influence of group size and personality on varying grade levels.
Date: December 2012
Creator: Young, Chase
Partner: UNT Libraries

Clustering Algorithms for Time Series Gene Expression in Microarray Data

Description: Clustering techniques are important for gene expression data analysis. However, efficient computational algorithms for clustering time-series data are still lacking. This work documents two improvements on an existing profile-based greedy algorithm for short time-series data; the first one is implementation of a scaling method on the pre-processing of the raw data to handle some extreme cases; the second improvement is modifying the strategy to generate better clusters. Simulation data and real microarray data were used to evaluate these improvements; this approach could efficiently generate more accurate clusters. A new feature-based algorithm was also developed in which steady state value; overshoot, rise time, settling time and peak time are generated by the 2nd order control system for the clustering purpose. This feature-based approach is much faster and more accurate than the existing profile-based algorithm for long time-series data.
Date: August 2012
Creator: Zhang, Guilin
Partner: UNT Libraries

Behavioral Aspects of Latino Familialism: a Three Study Analysis

Description: The existing research on Latino familialism draws a distinction between the attitudes associated with familialism and familialism-based action. Because attitudes tend to be more stable when considering variables such as immigration generation status, etc., social science researchers tend to employ measures based on attitudinal aspects of familialism, rather than action or behavior. Because of this preference, there is a lack of studies that examine familialism-based action and behaviors. This dissertation consists of three unique studies that examine actions and behaviors associated with familialism, while taking into account the methodological concerns expressed by previous researchers. The first study uses nationally representative U.S. data to compare the differences in the frequency of contact with various family members, among black non-Hispanics, Hispanics, and white non-Hispanics. The central finding of this study is that Hispanics maintain more frequent contact with family than white non-Hispanics, but there is no difference between Hispanics and black non-Hispanics, with the exception of contact with fathers. The second study, which employs qualitative data collected from a metropolitan area in the Southwest U.S., examines the locus of educational aspirations and expectations among a sample of Hispanics and white non-Hispanics. Among other things, this study finds that Hispanic females were more likely than other participants to make statements that suggest the aspirations or expectations of significant others were a strong influence in the decision to attend college. This study further argues that this tendency is related to the acquiescent nature of traditional Hispanic gender norms associated with the familial concept of marianismo. Using nationally representative U.S. data, the final study finds that, other things being equal, Hispanic college students are more likely than non-Hispanic students to attend a college or university that is within fifty miles of their permanent residence. The study further finds that this tendency mediates the gap between ...
Date: December 2012
Creator: Comeau, Joseph Adrien
Partner: UNT Libraries

Osvaldo Lacerda’s Sonata for Flute and Piano (1959): A Performance Guide with Historical Background of Brazilian Genres Embolada, Serestra, and Baião

Description: Osvaldo da Costa Lacerda (March 23, 1927-July 18, 2011), one of the most significant Brazilian composers of the twentieth century, wrote more than 250 compositions. The purpose of this dissertation is to provide a history and analysis of the Brazilian genres characterized in Osvaldo Lacerda’s, Sonata for Flute and Piano. Written in 1959, the sonata represents traditional Brazilian rhythms within a classical structure and modern harmony. The work provides a basis for the exploration of the embolada, the serestas, and the baião, examples of Brazilian typical song forms and rhythms. Analysis of the historical roots of these nationalistic elements will provide appropriate performance practice considerations when playing Brazilian rhythms; and because this sonata only exists in manuscript form, the historical analysis and performance guide will be of service to disseminate this important Brazilian work. As a basis for a critical edition of the Sonata for Flute and Piano, this initial effort will provide performers with a context for Brazilian flute music. Chapters include the Lacerda’s biography, a background of the nationalistic movement in Brazil and the composers who have influenced Osvaldo Lacerda. Definitions of embolada, serestas, and baião is also provided.
Date: December 2012
Creator: Gimenes, Marilia Gabriela do Nascimento
Partner: UNT Libraries

Group 10 Catalyzed Olefin Hydroarylation

Description: Alkyl-arenes are important industry feedstock chemicals that are used as solvents, pharmaceutical precursors, and polymer monomer units. One alkyl-arene, ethylbenzene, is the main focus of this dissertation, and is produced in the million ton a year scale. As alkyl-arenes are important commodity chemicals, catalytic olefin hydroarylation is a lucrative alternative for their production rather than Friedel-Crafts alkylation or various coupling reactions that have lower atom economy, require strong acids, or are energetically demanding. Currently catalytic olefin hydroarylation still suffers from decomposition pathways of the active catalytic complexes, side reactions that lead to waste products, and unfavorable activation barriers, which represent high temperature and pressure. Modifications to the catalytically active system bipyridine platinum(II) (bpyPtII), through computational methods, are explored herein. The work presented here investigates catalytic olefin hydroarylation in order to mitigate the aforementioned difficulties. Included in this study are changes to the electronic profile of the supporting ligand, bpy, through the addition of electron withdrawing or electron donating R groups (methoxy, nitro), definite ligand replacements such as bpy to hydridotris(pyrazolyl)borate (Tp), changes in metal oxidation (II to IV), and replacing the metal center from Pt to Ni. Nickel was selected as a possible alternative to platinum as it is more Earth abundant reducing the monetary requirement for the catalyst. In addition to having a different catalytic energetic profile from platinum. Ni as expected could only facilitate single step hydrogen atom transfers due to its inability to access higher oxidations states.
Date: December 2012
Creator: Gonzalez, Hector Emanuel
Partner: UNT Libraries

A Descriptive Law and Policy Analysis of Corporal Punishment in Florida Public School Districts

Description: Corporal punishment is banned by state statute in 31 of the 50 U.S states. The 19 states that still allow the practice are largely located in the South and the Rocky Mountain West. However, data indicate that the practice of corporal punishment is still largely a Southern phenomenon. In the 19 states that allow the practice to continue in schools, many have seen the use of the disciplinary technique decline. Existing research documents the negative effects and very little research supports any positive benefits of corporal punishment. This study analyzes school board policies from the 67 public school districts in the state of Florida to determine if trends in policies and incidents of corporal punishment are similar Texas and North Carolina. Research on Texas and North Carolina indicate corporal punishment is used more frequently in districts with smaller enrollments, and in more rural areas. Data from this study suggests that the decrease in the number of incidents of corporal punishment as well as the concentration of the practice among school districts in Florida school follows the same trends of declining use that exist in Texas and North Carolina public schools. Findings illustrate a need for continued research of corporal punishment on a district-by-district and potentially a school-by-school basis.
Date: December 2012
Creator: Goodson, Christopher B.
Partner: UNT Libraries