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 Decade: 2010-2019
 Collection: UNT Theses and Dissertations
9-Lipoxygenase Oxylipin Pathway in Plant Response to Biotic Stress
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The activity of plant 9-lipoxygenases (LOXs) influences the outcome of Arabidopsis thaliana interaction with pathogen and insects. Evidence provided here indicates that in Arabidopsis, 9-LOXs facilitate infestation by Myzus persicae, commonly known as the green peach aphid (GPA), a sap-sucking insect, and infection by the fungal pathogen Fusarium graminearum. in comparison to the wild-type plant, lox5 mutants, which are deficient in a 9-lipoxygenase, GPA population was smaller and the insect spent less time feeding from sieve elements and xylem, thus resulting in reduced water content and fecundity of GPA. LOX5 expression is induced rapidly in roots of GPA-infested plants. This increase in LOX5 expression is paralleled by an increase in LOX5-synthesized oxylipins in the root and petiole exudates of GPA-infested plants. Micrografting experiments demonstrated that GPA population size was smaller on plants in which the roots were of the lox5 mutant genotype. Exogenous treatment of lox5 mutant roots with 9-hydroxyoctadecanoic acid restored water content and population size of GPA on lox5 mutants. Together, these results suggest that LOX5 genotype in roots is critical for facilitating insect infestation of Arabidopsis. in Arabidopsis, 9-LOX function is also required for facilitating infection by F. graminearum, which is a leading cause of Fusarium head blight (FHB) disease in wheat and other small grain crops. Loss of LOX1 and LOX5 function resulted in enhanced resistance to F. graminearum infection. Similarly in wheat, RNA interference mediated silencing of the 9-LOX homolog TaLpx1, resulted in enhanced resistance to F. graminearum. Experiments in Arabidopsis indicate that 9-LOXs promote susceptibility to this fungus by suppressing the activation of salicylic acid-mediated defense responses that are important for basal resistance to this fungus. the lox1 and lox5 mutants were also compromised for systemic acquired resistance (SAR), an inducible defense mechanism that is systemically activated throughout a plant in response to a localized infection. the lox1 and lox5 mutants exhibited reduced cell death and delayed hypersensitive response when challenged with an avirulent strain of the bacterial pathogen Pseudomonas syringae pv tomato. LOX1 and LOX5 functions were further required for the synthesis as well as perception of a SAR-inducing activity present in petiole exudates collected from wild-type avirulent pathogen-challenged leaves. Taken together, results presented here demonstrate that 9-LOX contribute to host susceptibility as well as defense against different biotic stressors. digital.library.unt.edu/ark:/67531/metadc115127/
Ab Initio and Density Functional Investigation of the Conformer Manifold of Melatonin and a Proposal for a Simple Dft-based Diagnostic for Nondynamical Correlation
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In this work we address two problems in computational chemistry relevant to biomolecular modeling. In the first project, we consider the conformer space of melatonin as a a representative example of “real-life” flexible biomolecules. Geometries for all 52 unique conformers are optimized using spin-component scaled MP2, and then relative energies are obtained at the CCSD (T) level near the complete basis set limit. These are then used to validate a variety of DFT methods with and without empirical dispersion corrections, as well as some lower-level ab initio methods. Basis set convergence is found to be relatively slow due to internal C-H…O and C-H…N contacts. Absent dispersion corrections, many DFT functionals will transpose the two lowest conformers. Dispersion corrections resolve the problem for most functionals. Double hybrids yield particularly good performance, as does MP2.5. In the second project, we propose a simple DFT-based diagnostic for nondynamical correlation effects. Aλ= (1-TAE [ΧλC]/TAE[XC])/λ where TAE is the total atomization energy, XC the “pure” DFT exchange-correlation functional, and ΧλC the corresponding hybrid with 100λ% HF-type exchange. The diagnostic is a good predictor for sensitivity of energetics to the level of theory, unlike most of the wavefunction-based diagnostics. For GGA functionals, Aλ values approaching unity indicate severe non-dynamical correlation. The diagnostic is only weakly sensitive to the basis set (beyond polarized double zeta) and can be applied to problems beyond practical reach of wavefunction ab-initio methods required for other diagnostics. digital.library.unt.edu/ark:/67531/metadc500195/
The Academic Steroid: Nonmedical Use of Prescription Stimulants at a North Texas University
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The goal of this study was to determine the extent, motivations, and justifications of nonmedical prescription stimulant use among the population at a large public university in the North Texas region. Participants consisted of 526 undergraduate students enrolled at the studied university during the spring and summer 2014 semesters. The findings of the study suggest that the nonmedical use by students was higher than the findings in much of the current literature, but was within the parameters established in the literature. The primary motivation for nonmedical use was academic in nature and was justified by moderation of nonmedical use to strategic academic times. digital.library.unt.edu/ark:/67531/metadc699893/
Acute Effects of the Antibiotic Streptomycin on Neural Network Activity and Pharmacological Responses
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The purpose of this study is to find out that if antibiotic streptomycin decreases neuronal network activity or affects the pharmacological responses. The experiments in this study were conducted via MEA (multi-electrode array) technology which records neuronal activity from devices that have multiple small electrodes, serve as neural interfaces connecting neurons to electronic circuitry. The result of this study shows that streptomycin lowered the spike production of neuronal network, and also, sensitization was seen when neuronal network pre-exposed to streptomycin. digital.library.unt.edu/ark:/67531/metadc700026/
American Blitzkrieg: Courtney Hodges and the Advance Toward Aachen (August 1 - September 12, 1944)
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This is an analysis of combat operations of US First Army under the command of Courtney Hodges, between August 1 and September 12, 1944, with an emphasis upon 1st, 4th, 9th, and 30th Divisions. However, other formations are necessarily discussed in order to maintain context. Indeed, many historians have failed to emphasize the complex interdependent nature of these efforts, and the traditional narrative has been distorted by inadequate situational awareness. This study argues that the army's operations were exceedingly difficult, resulting in approximately 40,000 casualties over a six week period. Although historians claim that the Germans were essentially defeated by the end of July, and that the Allied advance was subsequently halted by logistical difficulties, the official combat records clarify that logistical shortages were a tertiary factor, as the enemy remained capable of strong resistance. Consequently, defensive efforts were the primary factor hindering the advance, in conjunction with deteriorating weather conditions, rugged terrain, and surprisingly severe traffic congestion. Although this was mobile warfare, military theorists have overestimated the effectiveness of mechanization and underestimated the potential for antitank defenses. Ultimately, this study asserts that First Army was the primary American combat formation, and historians have exaggerated the importance of George Patton's Third Army. Therefore, in order to understand an American way of war, the combat operations of First Army deserve far more attention than they have previously received. This narrative thus emphasizes forgotten battles, including: Tessy, St. Sever, Tete, Perriers, Mayenne, Ranes, Flers, Mace, Elbeuf, Mantes, Corbeil, Sevran, Mons, Cambrai, Philippeville, Dinant, and Aubel. digital.library.unt.edu/ark:/67531/metadc177245/
American Indian Worldviews, Risk Perceptions and Disaster Planning: an Exploratory Study
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It is commonly assumed that when confronted with an imminent hazard that people will react rationally, and prepare for, or at least attempt to avoid, danger from pending disasters. However, this conventional wisdom is not as evident as it appears. People prepare for, react to, or take social action to avoid hazards when they perceive the risk of danger to be threatening enough to warrant action, providing one has the will, insight and resources to do so. However, not all people perceive risks similarly. Risk is perceived differently by different people which affects risk perception and responses to hazards. This dissertation explores the relationships between American Indian worldviews, risk perceptions and disaster planning. To carry out this research 28 American Indians were interviewed. The sample consists of 14 American Indians residing in a rural are on the northern plains and 14 urban American Indians. The results only partially support that worldview is linked to risk perception and subsequent disaster planning. Other factors found to relate to risk perception and disaster planning for this non-representative sample of American Indians include various forms of social vulnerability. digital.library.unt.edu/ark:/67531/metadc407742/
Americans Who Would Not Wait: The American Legion of the Canadian Expeditionary Force, 1915-1917
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This dissertation examines the five battalions of the Canadian Expeditionary Force designated as the American Legion. Authorized in Canada between 1915 and 1917, these units were formed to recruit volunteers from the United States to serve in the Canadian Overseas Contingent during the First World War. This work reviews the organization of Canada’s militia and the history of Anglo-American relations before examining the Canadian war effort, the formation of the American Legion, the background of its men, and the diplomatic, political, and constitutional questions that it raised. Much of the research focuses on the internal documents of its individual battalions (the 97th, 211th, 212th, 213th and 237th) and the papers of Reverend Charles Bullock now housed at the Public Archives of Canada. Documentation for the diplomatic furor the American Legion caused comes largely through the published diplomatic documents, British Foreign Office records held at the Public Record Office at Kew, and United States Department of State files at the National Archives at College Park, Maryland. The most useful sources for American Legion correspondence are the Beaverbrook papers held at the House of Lords Record Office, the papers of Canadian Prime Minister Sir Robert Laird Borden, and those of the Governor-General, the Duke of Connaught found in the Public Archives of Canada. During its brief existence the American Legion precipitated diplomatic and political problems in the United States, the United Kingdom, and the Dominion of Canada. Among the issues raised by the controversy surrounding the American Legion were: the relationship between the dominion government in Canada and the British government; the structural problems of imperial communications; the rise of a Canadian national identity and the desire for greater autonomy; and, the nature of citizenship and expatriation. This dissertation is also a long overdue account of the thousands of United States citizens who left their homes and families to join the American Legion in order to fight another country’s war. digital.library.unt.edu/ark:/67531/metadc177171/
Anchor Nodes Placement for Effective Passive Localization
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Wireless sensor networks are composed of sensor nodes, which can monitor an environment and observe events of interest. These networks are applied in various fields including but not limited to environmental, industrial and habitat monitoring. In many applications, the exact location of the sensor nodes is unknown after deployment. Localization is a process used to find sensor node's positional coordinates, which is vital information. The localization is generally assisted by anchor nodes that are also sensor nodes but with known locations. Anchor nodes generally are expensive and need to be optimally placed for effective localization. Passive localization is one of the localization techniques where the sensor nodes silently listen to the global events like thunder sounds, seismic waves, lighting, etc. According to previous studies, the ideal location to place anchor nodes was on the perimeter of the sensor network. This may not be the case in passive localization, since the function of anchor nodes here is different than the anchor nodes used in other localization systems. I do extensive studies on positioning anchor nodes for effective localization. Several simulations are run in dense and sparse networks for proper positioning of anchor nodes. I show that, for effective passive localization, the optimal placement of the anchor nodes is at the center of the network in such a way that no three anchor nodes share linearity. The more the non-linearity, the better the localization. The localization for our network design proves better when I place anchor nodes at right angles. digital.library.unt.edu/ark:/67531/metadc33132/
“The Angular Degrees of Freedom” and Other Stories
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The preface, " Performing Brain Surgery: The Problematic Nature of Endings in Short Fiction," deals with the many and varied difficulties short story writers encounter when attempting to craft endings. Beginning with Raymond Carver and Flannery O’Connor and moving to my own work, I discuss some of the obscure criteria used to designate a successful ending, as well as the more concrete idea of the ending as a unifying element. Five short stories make up the remainder of this thesis: "In-between Girls," "Crocodile Man," "Surprising Things, Sometimes Amusing," "Good Jewelry," and "The Angular Degrees of Freedom." digital.library.unt.edu/ark:/67531/metadc700030/
Aphorismen, Capriccio, and Heptameron for Piano Solo By Jürg Baur: a Performer's Guide
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The purpose of this dissertation is to give instruction regarding the performance of three important piano works by Jürg Baur (1918-2010). Aphorismen, Capriccio, and Heptameron stand out as his most significant piano works both because of their length and because of their pianistic complexity. Since Baur had a successful career as both teacher and composer during his lifetime, his acclaimed works received many honors in Germany. His works can be performed by intermediate to advanced students. Intermediate students can easily offer simpler pieces like Aphorismen in competitions, while pieces like Capriccio and Heptameron better are suited to a more advanced level. Although some of his compositions are difficult to perform compared with other modern German works, Baur's music is more accessible. In the article, "Auf der Spuren der alten Zeit" Baur is quoted to state that Paul Hindemith and Bela Bartok's music influenced his own compositional ideas. However, although Baur is a modern composer, he didn't write in a totally atonal style, but rather attempted to broaden tonality. While Heptameron is atonal, Aphorismen and Capriccio give the impression of tonality, thus they are more accessible to the audience. I was fortunate enough to study Aphorismen with Baur as well as receiving advice for performance of Capriccio and some movements of Heptameron. Therefore, I gained a primary source of instruction, particularly in regards to pedal markings, rhythmic indications, voice balancing, finger suggestions, articulation markings, and tone of musical expression. In this dissertation, I include my own instructions (accepted by the composer) along with the composer's intentions. digital.library.unt.edu/ark:/67531/metadc177239/
Assessing Social Determinants of Severe Mental Illness in High-risk Groups
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The primary objective of this research was to explore the impact of possible social factors on non-institutionalized adults 18 years of age or older residing in the United States who exhibited severe mental illness (SMI). A holistic sociological model was developed to explain SMI by incorporating elements of social learning theory, social disorganization theory, and gender socialization theory with social demographic factors. Based on the holistic sociological model, the following factors were investigated: demographic aspects of age, education, income and gender; gender socialization; influence of neighborhood area; social network influence based on communication and interaction among peers and family members; and socially deviant behaviors such as frequently smoking cigarettes, drinking alcohol and using drugs specifically marijuana. The impact of these factors on SMI was examined. A sample of 206 respondents drawn from National Survey on Drug Use and Health, 2003 was assessed. These respondents had answered all the questions related to SMI; social deviant behaviors; neighborhood environment; and communications among peers, family members and friends; and the other studied factors. Ordinary linear regression with interaction terms was employed as a statistical tool to assess the impact of social determinants on SMI. Being female, living a disorganized neighborhood, and frequent and high levels of smoking cigarettes and drinking alcohol had a significant influence on SMI. This reevaluation and reexamination of the role of gender socialization path, socially deviant behaviors like smoking and drinking, and community construction on SMI provided additional insights. This research is one of the first to develop a more holistic sociological model on SMI and explored the previously untested interactive relationships. The limitations of this study suggest the need to test a potential recursive research model and explore additional bi-directional associations. digital.library.unt.edu/ark:/67531/metadc500085/
An Assessment of Consumers' Willingness to Patronize Foreign-Based Business Format Franchises: An Investigation in the Fast-Food Sector
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This study aimed to address consumers' stereotypical categorizations in the form of essentialist views about foreign cultures and their effect on individual consumers, including their negative or aroused emotions and subsequent retail patronage behaviors. The research mission was to empirically assess the salient dimensions of consumers' states of mind (positive and negative affect, psychological essentialism, epistemic curiosity), states of being (store atmospherics), and states of action (retail patronage behaviors) in a cultural context based on Mehrabian-Russell theory of environmental psychology. Specifically, the retail patronage setting was selected as foreign-based fast-food franchises because it represents both a relevant and timely situational context for consumer behavior. This dissertation makes several contributions to international retail patronage literature. First, it frames curiosity as an aroused emotional state and finds support for the relationship between consumer epistemic curiosity and retail patronage. Second, it provides support for the linkage between consumer affect and retail patronage in an international retail setting. Third, it reveals that affect has a greater impact on retail patronage than epistemic curiosity. The overarching finding of this study is an inability to tie the cultural elements in retail atmospherics, including signs, symbols, and artifacts, to consumer emotions. In addition, we were unable to frame psychological essentialism as a personality trait that would reduce the levels of affect and curiosity in retail store environments characterized by foreign-cultural elements. digital.library.unt.edu/ark:/67531/metadc28417/
Bank Capital, Efficient Market Hypothesis, and Bank Borrowing During the Financial Crisis of 2007 and 2008
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During the Great Recession of 2007 and 2008, liquidity and credit dried up, threatening the stability of financial institutions, particularly the banking firms. Traditional source of funds from the last resort, the Discount Window of the Federal Reserve System, failed to remedy the liquidity problem. To assuage the liquidity and credit problem, the Federal Reserve System established several emergency lending facilities and provided unprecedented amount of loans to the banking industry. Using a dataset published by Bloomberg LLP in the aftermaths of the financial crisis, which contains daily loan balances from the Fed, I conduct an event study to test whether financial markets are efficient in reflecting all public, anticipated and classified information in security prices. The most important contribution of this dissertation to the finance discipline and literature is the investigation and analysis of the Fed’s unprecedented loans to the banking industry during the Great Recession and the market reaction to it. The second major contribution of this study is the empirical test of strong form efficient market hypothesis, which has not been feasible due to legal data challenges. This dissertation has other contributions to the finance discipline and banking research. First, I develop an algorithm for measuring the amount of borrowing by banks. Second, I introduce a new “loan balance” ratio to traditional list of bank financial ratios. Third, I use event study methodologies to allow for cross-correlation, heteroscedasticity and event induced-variance change in studying US banks’ performance during the Great Recession. digital.library.unt.edu/ark:/67531/metadc699938/
Between Comancheros and Comanchería: a History of Fort Bascom, New Mexico
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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. digital.library.unt.edu/ark:/67531/metadc283832/
Boosting for Learning From Imbalanced, Multiclass Data Sets
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In many real-world applications, it is common to have uneven number of examples among multiple classes. The data imbalance, however, usually complicates the learning process, especially for the minority classes, and results in deteriorated performance. Boosting methods were proposed to handle the imbalance problem. These methods need elongated training time and require diversity among the classifiers of the ensemble to achieve improved performance. Additionally, extending the boosting method to handle multi-class data sets is not straightforward. Examples of applications that suffer from imbalanced multi-class data can be found in face recognition, where tens of classes exist, and in capsule endoscopy, which suffers massive imbalance between the classes. This dissertation introduces RegBoost, a new boosting framework to address the imbalanced, multi-class problems. This method applies a weighted stratified sampling technique and incorporates a regularization term that accommodates multi-class data sets and automatically determines the error bound of each base classifier. The regularization parameter penalizes the classifier when it misclassifies instances that were correctly classified in the previous iteration. The parameter additionally reduces the bias towards majority classes. Experiments are conducted using 12 diverse data sets with moderate to high imbalance ratios. The results demonstrate superior performance of the proposed method compared to several state-of-the-art algorithms for imbalanced, multi-class classification problems. More importantly, the sensitivity improvement of the minority classes using RegBoost is accompanied with the improvement of the overall accuracy for all classes. With unpredictability regularization, a diverse group of classifiers are created and the maximum accuracy improvement reaches above 24%. Using stratified undersampling, RegBoost exhibits the best efficiency. The reduction in computational cost is significant reaching above 50%. As the volume of training data increase, the gain of efficiency with the proposed method becomes more significant. digital.library.unt.edu/ark:/67531/metadc407775/
Business/it Alignment: the Impact of Incentive Plans on the Development of Shared Vision
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This study, utilizing Preston and Karahanna’s framework for shared vision development and Agency Theory, explores the impact of vision development factors and factors associated with incentive plans on shared vision and alignment. Results of the study confirm the strong relationship between shared vision and alignment, and indicate that having an effective management team is important with respect to developing and maintaining shared vision and alignment within the organization. Several vision development factors such as using the language of the business, participation on the top management team (TMT), and having knowledge of the business impact shared vision through their influence on teamwork. Also, results of this study suggest that participation on the TMT by the CIO/IT leader is more important than the individual’s position in the organizational hierarchy. In addition, attributes associated with incentive plans such as achievable and clear measures, measures linked to organizational goals, measures that align the interests of the individual with those of the organization, regular plan reviews, and using a balanced scorecard approach with respect to incentive plan design positively impact teamwork and shared vision. For practitioners, this highlights the importance of incentive plans as powerful tools that can be used to reinforce shared vision, effective teamwork, and alignment within the organization. Also, the CIO/IT leader needs to be knowledgeable of the business and must fill the role of both a technologist as well as an enterprise leader. This person must be an evangelist communicating the value and benefits of IT to the rest of the organization. digital.library.unt.edu/ark:/67531/metadc700035/
Can These Bones Live? A Collection of Stories
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The collection concerns itself with race, gender, masculinity, marginalization, the act of violence as a means of self expression, identity and the performance of identity, love, and loss. The collection also uses historical events-more specifically, events that are central to black culture in Northeast, Ohio- to situate the characters and witness their response to these historical events. I strive to illustrate blackness as both political and fragmented with the characters in my collection. My characters believe that what they are doing-exacting violence, abusing women, disrespecting each other- is somehow the normative; that somehow what it is that they have learned is how they should perform black identity. digital.library.unt.edu/ark:/67531/metadc28431/
Challenge the Silence
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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. digital.library.unt.edu/ark:/67531/metadc283840/
Child Rescue As Survival Resistance: Hidden Children in Nazi-occupied Western Europe
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The phenomenon of rescue organizations that devoted themselves specifically to hiding and saving Jewish children appeared throughout Nazi-occupied Western Europe (France, Belgium, and the Netherlands). Jewish and non-Jewish rescuers risked their lives to save thousands of children from extermination. This dissertation adds to the historiographical understanding of Holocaust resistance by analyzing the efforts of these child rescue organizations as a form of “survival resistance.” Researching the key aspects of traditional resistance (conscious intent, extensive organization, and effective turn-out) demonstrates that, while child rescue did not present armed resistance, it still was a form of active resistance against the Nazi Final Solution. By looking at rescuers’ testimonies and archival sources (from Yad Vashem, United States Holocaust Memorial Museum, Centre de documentation juive contemporaine, and Kazerne Dossin), this dissertation first outlines the extensive organization and intent of Jewish rescue groups, such as the Oeuvre de Secours aux Enfants (OSE) and Comité de défense des Juifs (CDJ), in France, Belgium, and the Netherlands. The second part looks at rescue organization and intent by Catholic, Protestant, and humanitarian groups. The dissertation concludes by discussing the effectiveness of organized child rescue. In the end, the rescue groups saved thousands of children and proofs that Child rescue in Nazi-occupied Western Europe was a valid--not to mention heroic--form of survival resistance. digital.library.unt.edu/ark:/67531/metadc149581/
The Chopin Etudes: a Study Guide for Teaching and Learning Opus 10 and Opus 25
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The etudes of Chopin are masterworks of the piano literature and are designed to go beyond mere technical exercises; moreover, each etude represents not only a technical study but also has a distinct musical character. Alarmingly, the current trend seems to be to assign the Chopin etudes at an increasingly young age to students who are not yet equipped either technically or musically to handle them. As Chopin’s pupil, Carl Mikuli, commented in the preface to his Chopin edition, the etudes were meant for “more advanced students.” If Chopin had intended his etudes for students at an intermediate level, he would have assigned them to most of his students; however, only a limited number of students had his permission to work on their master’s etudes. As a teacher, I have always felt the need to devise a systematic teaching plan to guide students to handle the challenges of these pieces both physically and musically. This study examines the repertoire which might help prepare a student to learn the etudes without overstraining his/her muscular and mental ability. Rooted in Chopin’s teaching and his recommendation of the pieces to learn before tackling the etudes themselves, this pedagogical study guide intends to help students and teachers to work progressively towards the study of these works. While pinpointing some exercises and simple pieces to assign to a student in preparation for studying the individual etudes, helpful works of later composers are also liberally incorporated, as well as some suggestions for practicing the etudes themselves. Finally, I shall provide my own “re-ordering” of the etudes, with a progressive degree of difficulty, as an additional aid to a young pianist who may eventually want to learn the entire opus 10 and opus 25. digital.library.unt.edu/ark:/67531/metadc115039/
A Chorus of Trees
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This two-part thesis includes a critical preface and a collection of my poems. Using three poems-Louise Glück's "Lullaby," Bob Hicok's "Poem for My Mother's Hysterectomy," and Nick Flynn's "Memento Mori"-the critical preface examines how, in poetry, the transformation of a body negotiates trauma and triggers a conceptual shift, the creation and revision of identity, and the release of the duende's inspirational force. The collection of poetry that follows seeks to transfigure the body as a way to explore the nuanced traumas of human experience. digital.library.unt.edu/ark:/67531/metadc30485/
El Cine De Terror Español Como Espejo De La Cultura Española
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This study traces the history and culture of Spain as seen through the lens of the nation´s production of horror cinema. Starting from the boom of Spanish horror film in the early 1960s, the thesis compares and contrasts the political and social aspects of Spanish society throughout three distinct eras of the 20th century: 1962 – 1975 (the boom of Spanish horror film through the Franco dictatorship), 1975 – 1999 (the transition to democracy through the end of the 20th century) and 2000 – present (the 21st century). Movies as diverse as Gritos en la noche (1962, Jesús Franco), ¿Quién puede matar a un niño? (1976, Narciso Ibáñez Serrador) and Angustia (1987, Bigas Luna) are framed by culturally-related anectodes as well as correlations to their respective social environments. Special attention has been paid to the production and release of each film, especially in regards to censorship during the Franco dictatorship. The results show that Spanish horror cinema has acted as a true mirror to culture, society and politics in its native country throughout the 20th century and that this trend will likely extend in to the future. digital.library.unt.edu/ark:/67531/metadc500060/
A Comprehensive Modeling Framework for Airborne Mobility
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Mobility models serve as the foundation for evaluating and designing airborne networks. Due to the significant impact of mobility models on the network performance, mobility models for airborne networks (ANs) must realistically capture the attributes of ANs. In this paper, I develop a comprehensive modeling framework for ANs. The work I have done is concluded as the following three parts. First, I perform a comprehensive and comparative analysis of AN mobility models and evaluate the models based on several metrics: 1) networking performance, 2) ability to capture the mobility attributes of ANs, 3) randomness levels and 4) associated applications. Second, I develop two 3D mobility models and realistic boundary models. The mobility models follow physical laws behind aircraft maneuvering and therefore capture the characteristics of aircraft trajectories. Third, I suggest an estimation procedure to extract parameters in one of the models that I developed from real flight test data. The good match between the estimated trajectories and real flight trajectories also validate the suitability of the model. The mobility models and the estimation procedure lead to the creation of “realistic” simulation and evaluation environment for airborne networks. digital.library.unt.edu/ark:/67531/metadc407760/
The Contribution of Mira Behn and Sarala Behn to Social and Environmental Transformation in the Indian State of Uttarakhand
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The influence of Mohandas K. Gandhi on social and environmental movements in post-colonial India has been widely acknowledged. Yet, the contributions of two European associates of Gandhi, Madeleine Slade and Catherine Mary Heilemann, better known in India as Mira Behn and Sarala Behn, have not received the due attention of the academic community. This dissertation is an examination of the philosophy and social activism of Mira Behn and Sarala Behn and their roles in the evolution of Gandhian philosophy of socioeconomic reconstruction and environmental conservation in the present Indian state of Uttarakhand. Instead of just being acolytes of Gandhi, I argue that these women developed ideas and practices that drew upon from an extensive intellectual terrain that cannot be limited to Gandhi’s work. I delineate the directions in which Gandhian thought and experiments in rural development work evolved through the lives, activism, and written contributions of these two women. Particularly, I examine their influence on social and environmental movements, such as the Chipko and the Anti-Tehri Dam movements, and their roles in promoting grassroots social development and environmental sustainability in the mountain communities of Uttarakhand. Mira Behn and Sarala Behn’s integrative philosophical worldviews present epistemological, sociopolitical, ethical, and metaphysical principles and practices that have local and global significance for understanding interfaith dialog, social justice, and environmental sustainability and thus constitute a useful contribution to the theory and practice of human emancipation in our times. digital.library.unt.edu/ark:/67531/metadc499983/
Control and Automation of a Heat Shrink Tubing Process
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Heat shrink tubing is used to insulate wire conductors, protect wires, and to create cable entry seals in wire harnessing industries. Performing this sensitive process manually is time consuming, the results are strongly dependent on the operator’s expertise, and the process presents safety concerns. Alternatively, automating the process minimizes the operators’ direct interaction, decreases the production cost over the long term, and improves quantitative and qualitative production indicators dramatically. This thesis introduces the automation of a heat shrink tubing prototype machine that benefits the wire harnessing industry. The prototype consists of an instrumented heat chamber on a linear positioning system, and is fitted with two heat guns. The chamber design allows for the directing of hot air from the heat guns onto the wire harness uniformly through radially-distributed channels. The linear positioning system is designed to move the heat chamber along the wire harness as the proper shrinkage temperature level is reached. Heat exposure time as a major factor in the heat shrink tubing process can be governed by controlling the linear speed of the heat chamber. A control unit manages the actuator position continuously by measuring the chamber’s speed and temperature. A model-based design approach is followed to design and test the controller, and MATLAB/Simulink is used as the simulation environment. A programmable logic controller is selected as the controller implementation platform. The control unit performance is examined and its responses follow the simulation results with adequate accuracy. digital.library.unt.edu/ark:/67531/metadc699928/
The Correlates of Number of Minority Faculty, Minority Student Organizations, Diversity Course Offerings, and Geographic Location to Minority Student Enrollment in Texas Colleges
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This study examined the correlates between the dependent variables African-American and Hispanic student enrollment in Texas public higher education to the independent variables institution type, education region, faculty demographics, curricular offerings and student organizations. Data for African-American (n = 124,000) and Hispanic enrollment (n = 314,000) in all Texas public higher education institutions (n = 109) for the 2008 academic year were examined. Significant results, using a statistical significance of p = .005, were reported for two of the variables. A correlation of Pearson's r = .946 and statistical significance of p = .000 was observed between African-American student enrollment and the percentage representation of African-American faculty in the same institution. A correlation of Pearson's r = .982 and statistical significance of p = .000 was observed between Hispanic student enrollment and the percentage representation of Hispanic faculty in the same institution. The results of this study found significant relationships between the presence of African-American and Hispanic faculty and enrollment of African-American and Hispanic students. Recommendations are made for exploring these findings in further detail. digital.library.unt.edu/ark:/67531/metadc33131/
Cosmology, Extraterrestrial Life, and the Development and Character of Western European Thought in the Seventeenth and Eighteenth Centuries
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Cosmology, as an all-encompassing theoretical construction of universal reality, serves as one of the best indicators for a variety of philosophical, scientific, and cultural values. Within any cosmological system, the question of extraterrestrial life is an important element. Mere existence or nonexistence, however, only exposes a small portion of the ideological significance behind the contemplation of life outside of earth. The manners by which both believers and disbelievers justify their opinions and the ways they characterize other worlds and their inhabitants show much more about the particular ideas behind such decisions and the general climate of thought surrounding those who consider the topic. By exploring both physical and abstract structures of the universe, and specifically concepts on the plurality of worlds and extraterrestrial life, Western European thought in the seventeenth and eighteenth centuries reveals not an era of pure advancement and modernization, but as a time of both tradition and change. digital.library.unt.edu/ark:/67531/metadc84276/
The Counterinsurgency Dilemma: The Causes and Consequences of State Repression of Human Rights in Civil Wars
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In this project a theory of adaptive differential insurgency growth by the mechanism of repression driven contagion is put forth to explain variation in the membership and spatial expansion of insurgencies from 1981 to 1999. As an alternative to the dominant structural approaches in the civil war literature, Part 1 of the study proposes an interactive model of insurgency growth based on Most and Starr's opportunity and willingness framework. The findings suggest that state capacity, via its impact on state repressive behavior, plays an important gatekeeping function in selecting which minor insurgencies can grow into civil war, but contributes little to insurgency growth directly. In Part 2 of the study, I directly examine variation in insurgency membership and geographical expansion as a function of repression driven contagion. I find that repression increases the overall magnitude of insurgency activity within states, while at the same time reducing the density of insurgency activity in any one place. Despite an abundance of low intensity armed struggles against a highly diverse group of regimes around the world, I find an extremely strong and robust regularity: where repression is low - insurgencies don't grow. digital.library.unt.edu/ark:/67531/metadc28464/
Cuff-less Blood Pressure Measurement Using a Smart Phone
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Blood pressure is vital sign information that physicians often need as preliminary data for immediate intervention during emergency situations or for regular monitoring of people with cardiovascular diseases. Despite the availability of portable blood pressure meters in the market, they are not regularly carried by people, creating a need for an ultra-portable measurement platform or device that can be easily carried and used at all times. One such device is the smartphone which, according to comScore survey is used by 26.2% of the US adult population. the mass production of these phones with built-in sensors and high computation power has created numerous possibilities for application development in different domains including biomedical. Motivated by this capability and their extensive usage, this thesis focuses on developing a blood pressure measurement platform on smartphones. Specifically, I developed a blood pressure measurement system on a smart phone using the built-in camera and a customized external microphone. the system consists of first obtaining heart beats using the microphone and finger pulse with the camera, and finally calculating the blood pressure using the recorded data. I developed techniques for finding the best location for obtaining the data, making the system usable by all categories of people. the proposed system resulted in accuracies between 90-100%, when compared to traditional blood pressure meters. the second part of this thesis presents a new system for remote heart beat monitoring using the smart phone. with the proposed system, heart beats can be transferred live by patients and monitored by physicians remotely for diagnosis. the proposed blood pressure measurement and remote monitoring systems will be able to facilitate information acquisition and decision making by the 9-1-1 operators. digital.library.unt.edu/ark:/67531/metadc115102/
Culture and Self-Representation in the Este Court: Ercole Strozzi's Funeral Elegy of Eleonora of Aragon, a Text, Translation, and Commentary.
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This dissertation presents a previously unedited text by one of the most distinguished- yet neglected-Latin writers of the Italian Renaissance, Ercole Strozzi (1471-1508), a poet and administrator in the court of Ferrara. Under the Este Dukes, Ferrara became a major center of literary and artistic patronage. The Latin literary output of the court, however, has received insufficient scholarly scrutiny. The text is a verse funeral elegy of Eleonora of Aragon (1450-1493), the first Duchess of Ferrara. Eleonora was a remarkable woman whose talents and indefatigable efforts on behalf of her husband, her children, and her state, won her accolades both at home and abroad. She also served as a prototype for the remarkable careers of her two daughters, Isabella d'Este, and Beatrice d'Este, who are celebrated for their erudition and patronage of arts and letters. The text is a mirror of the Estense court and reveals to us how its members no doubt saw themselves, at the very peak of its temporal power and the height of its prestige as a center of cultural creativity. It is also important for the striking portrait it presents of Eleonora. Ercole Strozzi chose to call his poem an epicedium, an ancient minor literary genre that had received attention in the two decades prior to its composition, due to the discovery and printing of the silver age Roman poet Statius, whose text includes several epicedia. Strozzi deftly adapts and transcends both his ancient and contemporary models (especially Poliziano), and in the process, creates a new Latin literary genre, the Renaissance epicedium. It is a fine poem, full of both erudition and creativity, and as such is the first fruits of what would be Ercole Strozzi's illustrious poetic career. The work is genuinely worthy of study on both esthetic and historical grounds. digital.library.unt.edu/ark:/67531/metadc33223/
Daily-collected Sleep Diaries Compared to Weekly-collected Sleep Diaries Via Actigraph Concordance
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Both sleep diaries and actigraphy have been recommended to assess sleep in research and clinical settings. Investigators have traditionally used sleep diaries that were completed daily by participants and collected weekly but have recently begun using sleep diaries that are both completed and collected daily. No research had previously assessed the agreement between daily-collected sleep diaries and actigraph data over one week. Undergraduate students were randomly assigned to use daily- or weekly-collected sleep diaries. Sleep parameters obtained from these measures were compared to each other via concordance with concurrent actigraph data. It was hypothesized that daily-collected sleep diaries would have greater concordance with actigraphy than weekly-collected sleep diaries. Results indicated that daily-collected sleep diaries provided more reliable data than weekly-collected sleep diaries, but the differences were not statistically significant. Additional aims examined self-reported sleep diary adherence, the participation day number, and day of the week. There were trends for the Daily group to have better adherence. Overall concordance did not change based on the day number or day of the week. Both sleep diaries yield comparable sleep parameter data, suggesting that clinicians and researchers can use either method to estimate sleep parameters. digital.library.unt.edu/ark:/67531/metadc500117/
Data Compression Using a Multi-residue System (Mrs)
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This work presents a novel technique for data compression based on multi-residue number systems. The basic theorem is that an under-determined system of congruences could be solved to accomplish data compression for a signal satisfying continuity of its information content and bounded in peak-to -peak amplitude by the product of relatively prime moduli,. This thesis investigates this property and presents quantitative results along with MATLAB codes. Chapter 1 is introductory in nature and Chapter 2 deals in more detail with the basic theorem. Chapter 3 explicitly mentions the assumptions made and chapter 4 shows alternative solutions to the Chinese remainder theorem. Chapter 5 explains the experiments in detail whose results are mentioned in chapter 6. Chapter 7 concludes with a summary and suggestions for future work. digital.library.unt.edu/ark:/67531/metadc149639/
Dead Fox Run: A Collection of Stories
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This collection consists of a critical preface and five linked short stories. The preface analyzes the usage of violence in literate and other forms of media, and specifically the ways in which literature can address violence without aggrandizing or stylizing it. The stories explore this idea through the lens of the lives of two young men, following them from boyhood marked by violence to adulthood crushed by the trauma of the American Civil War. Collection includes the stories "Dead Foxes," "Cow Pen," "Fatherless," "Woodsmoke," and "Brotherhood." digital.library.unt.edu/ark:/67531/metadc68046/
Design, Synthesis and Screening of Homoleptic and Heteroleptic Platinum(ii) Pyridylazolate Complexes for N-type Semiconducting and Light-emitting Devices
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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. digital.library.unt.edu/ark:/67531/metadc283853/
Designing Tools to Probe the Calcium-dependent Function of Arabidopsis Tonneau2
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Plants possess unique features in many aspects of development. One of these features is seen in cell wall placement during cytokinesis, which is determined by the position of the preprophase band (PPB) and the subsequent expansion of the phragmoplast that deposits the new cell wall. During phragmoplast expansion, the phragmoplast tracks to the cortical division site, which was delineated by the PPB. Thus the position of the PPB determines the orientation of the division plane. In Arabidopsis thaliana, TONNEAU2 (TON2) is required for PPB formation and has been shown to interact with a type A subunit of the PP2A phosphatase in the yeast two-hybrid system. In Arabidopsis tonneau2 (ton2) mutants, abnormalities of the cortical microtubule cytoskeleton, such as disorganization of the interphase microtubule array and lack of PPB formation before mitosis markedly affects cell shape and arrangement as well as overall plant morphology. Loss of dcd1/add1, the maize ton2 homologues gives rise to a similar phenotype in Zea mays. The TON2 protein has two EF hand domains which are calcium-binding sites. Since calcium has been known to play key roles in several areas of plant functioning, the following question was raised: “Does calcium binding contribute to the localization and function of TONNEAU at the PPB?” To address this question, a series of constructs were generated to determine if TON2 binds calcium. Additionally, Ca2+ binding sites were mutated in constructs containing the TON2 gene fused to GFP or YPF. These constructs were then transformed into ton2 mutant plants and the localization of TON2 fusion protein and whether the construct is capable of rescuing the mutant phenotype were observed. Although, localization of TON2 to the PPB was not observed, the presence of the constructs were confirmed in the transformed plants using selection markers and by observing fluorescence under a confocal microscope. digital.library.unt.edu/ark:/67531/metadc407800/
Determinants of Mental Health Problems Among College Students
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Many college students have reported struggling with mental health problems while dealing with challenging demands of college. The initial theoretical framework for this research was Pearlin's stress process model (SPM). Building on the SPM, the three additional mediating variables of perceived control, meaninglessness, and financial worries were added to create a composite model for the research. Mental health outcomes in the model were measured by a comprehensive range of factors, which included: psychological distress, suicide, substance abuse, and anger. Data were collected from a non-probability convenience sample of 463 undergraduate students attending a large state supported university in the southwestern region of the United States. Among the social status variables measured, being married, female, and white were significant predictors of poor mental health in the sampled college students. Poor self-image, feeling of meaninglessness, and worrying about current and future finances were significant mediating variables. Poor mental health could make individuals overwhelmed and discouraged. This is a formula for failure in college. The results of this study contribute to a better understanding of the correlates of mental health problems among college students. A greater understanding means that families and college administrations will have better ideas about how to intervene to reduce the stress of students and to focus the available and often limited resources to help young adults in their college experience. digital.library.unt.edu/ark:/67531/metadc33227/
Development of Indium Oxide Nanowires as Efficient Gas Sensors
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Crystalline indium oxide nanowires were synthesized following optimization of growth parameters. Oxygen vacancies were found to impact the optical and electronic properties of the as-grown nanowires. Photoluminescence measurements showed a strong U.V emission peak at 3.18 eV and defect peaks in the visible region at 2.85 eV, 2.66 eV and 2.5 eV. The defect peaks are attributed to neutral and charged states of oxygen vacancies. Post-growth annealing in oxygen environment and passivation with sulphur are shown to be effective in reducing the intensity of the defect induced emission. The as-grown nanowires connected in an FET type of configuration shows n-type conductivity. A single indium oxide nanowire with ohmic contacts was found to be sensitive to gas molecules adsorbed on its surface. digital.library.unt.edu/ark:/67531/metadc103318/
Development of Silicon Nanowire Field Effect Transistors
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An economically reliable technique for the synthesis of silicon nanowire was developed using silicon chloride as source material. The 30-40 micron long nanowires were found to have diameters ranging from 40 – 100 nm. An amorphous oxide shell covered the nanowires, post-growth. Raman spectroscopy confirmed the composition of the shell to be silicon-dioxide. Photoluminescence measurements of the as-grown nanowires showed green emission, attributed to the presence of the oxide shell. Etching of the oxide shell was found to decrease the intensity of green emission. n-type doping of the silicon nanowires was achieved using antimony as the dopant. The maximum dopant concentration was achieved by post-growth diffusion. Intrinsic nanowire parameters were determined by implementation of the as-grown and antimony doped silicon nanowires in field effect transistor configuration. digital.library.unt.edu/ark:/67531/metadc103364/
Device Engineering for Enhanced Efficiency from Platinum(II) Phosphorescent OLEDs
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Phosphorescent organic light emitting diodes (PHOLEDs) based on efficient electrophosphorescent dopant, platinum(II)-pyridyltriazolate complex, bis[3,5-bis(2-pyridyl)-1,2,4-triazolato]platinum(II) (Pt(ptp)2) have been studied and improved with respect to power efficiency, external efficiency, chromacity and efficiency roll-off. By studying the electrical and optical behavior of the doped devices and functionality of the various constituent layers, devices with a maximum EQE of 20.8±0.2 % and power efficiency of 45.1±0.9 lm/W (77lm/W with luminaries) have been engineered. This improvement compares to devices whose emission initially could only be detected by a photomultiplier tube in a darkened environment. These devices consisted of a 65 % bis[3,5-bis(2-pyridyl)-1,2,4-triazolato]platinum(II) (Pt(ptp)2) doped into 4,4'-bis(carbazol-9-yl)triphenylamine (CBP) an EML layer, a hole transporting layer/electron blocker of 1,1-bis[(di-4-tolylamino)phenyl]cyclohexane (TAPC), an electron transport layer of 1,3,5-tris(phenyl-2-benzimidazolyl)-benzene (TPBI), and a LiF/Al cathode. These devices show the acceptable range for warm white light quadrants and qualify to be called "warm white" even w/o adding another emissive layer. Dual EML devices composed of neat Pt(ptp)2 films emitting orange and CBP: Pt(ptp)2 film emitting blue-green produced a color rendering index (CRI) of 59 and color coordinates (CIE) of (0.47,0.49) at 1000Cd/m² with power efficiency of 12.6±0.2 lm/W and EQE of 10.8±0.2 %. Devices with two blue fluorescent emission layers as singlet filters and one broad yellow emission layer from CBP: Pt(ptp)2 displayed a CRI of 78 and CIE of (0.28,0.31) at 100Cd/m² with maximum power efficiency of 6.7±0.3 lm/W and EQE of 5.7±0.2 %. digital.library.unt.edu/ark:/67531/metadc30482/
Dolores Dyer: Women's Basketball and the American Dream
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Dolores Dyer played from 1952-1953 for the Texas Cowgirls, a barnstorming women's basketball team that provided a form of entertainment popular throughout the United States in that era. The story of Dyer's life demonstrates how a woman could attempt to achieve the American dream—a major theme in American history—through success in athletic competition. Dyer's participation with the Texas Cowgirls also provides a look into the circumstances that limited women's participation in professional sport during the mid-twentieth century. Women's sports studies, although some are very thorough, have gaps in the research, and women's barnstorming basketball is one of the areas often overlooked. In light of this gap, this thesis relies on a variety of sources, including primary documents from unpublished collections, archived materials, and original oral histories from several members of the Texas Cowgirls team. This thesis contains analysis of the socioeconomic factors that influenced Dolores Dyer's maturation into a professional basketball player, examines what the American dream meant to her, and evaluates the extent to which she achieved it. Overall, it constructs a social history that can serve as a foundational source for further study of women in sports during the twentieth century. digital.library.unt.edu/ark:/67531/metadc177246/
Dream of a Thousand Keys: A Concerto for Piano and Orchestra
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Dream of a Thousand Keys is a concerto for piano and orchestra, which consists of four movements presenting multiple dimensional meanings as suggested by the word "key." I trace the derivation of Korean traditional rhythmic cycles and numerical sequences, such as the Fibonacci series, that are used throughout the work, and explore the significant role of space between the soloist and piano that are emphasized in a theatrical aspect of the composition. The essay addresses the question of musical contrasts, similarities, and metamorphosis. Lastly, I cover terms and concepts of significant 21st-century compositional techniques that come into play in the analysis of this work. digital.library.unt.edu/ark:/67531/metadc67968/
A Driver, Vehicle and Road Safety System Using Smartphones
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As vehicle manufacturers continue to increase their emphasis on safety with advanced driver assistance systems (ADAS), I propose a ubiquitous device that is able to analyze and advise on safety conditions. Mobile smartphones are increasing in popularity among younger generations with an estimated 64% of 25-34 year olds already using one in their daily lives. with over 10 million car accidents reported in the United States each year, car manufacturers have shifted their focus of a passive approach (airbags) to more active by adding features associated with ADAS (lane departure warnings). However, vehicles manufactured with these sensors are not economically priced while older vehicles might only have passive safety features. Given its accessibility and portability, I target a mobile smartphone as a device to compliment ADAS that can bring a driver assist to any vehicle without regards for any on-vehicle communication system requirements. I use the 3-axis accelerometer of multiple Android based smartphone to record and analyze various safety factors which can influence a driver while operating a vehicle. These influences with respect to the driver, vehicle and road are lane change maneuvers, vehicular comfort and road conditions. Each factor could potentially be hazardous to the health of the driver, neighboring public, and automobile and is therefore analyzed thoroughly achieving 85.60% and 89.89% classification accuracy for identifying road anomalies and lane changes, respectively. Effective use of this data can educate a potentially dangerous driver on how to operate a vehicle safely and efficiently. with real time analysis and auditory alerts of these factors, I hope to increase a driver's overall awareness to maximize safety. digital.library.unt.edu/ark:/67531/metadc115086/
Economic Mobility into the Planter Class in Texas, 1846-1860
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This study examines upward economic mobility into the planter class in Texas during the antebellum statehood period, 1846-1860. Using quantitative methods to analyze data from census and tax records, this study addresses several questions regarding the property owning experience of Texas planters. Did any of the 1860 planters, men or women, rise to that status from another class? If so, how many rose from small slaveholder or small planter origins, and how many advanced from plain folk origins? In what ways did the amount and nature of wealth of these individuals change in the period studied? In what ways do these findings provide insights into the debate over planter dominance versus ‘plain folk’ inclusive herrenvolk democracy and the relationship between the planters and the other classes? Did the experiences of female planters differ from that of male planters? Did female planter experiences in Texas differ from female planters in other parts of the Old South? The results of these questions demonstrate that economic class mobility into the richest class was significant but limited and that women’s experiences were closely tied to those of male kin. digital.library.unt.edu/ark:/67531/metadc103363/
The Effect of Natural Gas Well Setback Distance on Drillable Land in the City of Denton, Texas
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Municipalities protect human health and environmental resources from impacts of urban natural gas drilling through setback distances; the regulation of distances between well sites and residences, freshwater wells, and other protected uses. Setback distances have increased over time, having the potential to alter the amount and geographical distribution of drillable land within a municipality, thereby having implications for future land use planning and increasing the potential for future incompatible land uses. This study geographically applies a range of setback distances to protected uses and freshwater wells in the city limits of Denton, Texas to investigate the effect on the amount of land remaining for future gas well development and production. Denton lies on the edge of a productive region of the Barnett Shale geological formation, coinciding with a large concentration of drillable land in the southwestern region of the study area. This region will have the greatest potential for impacts to future municipal development and land use planning as a result of future gas well development and higher setback standards. Given the relatively high acreage of drillable land in industrially zoned subcategory IC-G and the concern regarding gas well drilling in more populated areas, future drilling in IC-G, specifically in IC-G land cover classes mowed/grazed/agriculture and herbaceous, would have the least impact on residential uses and tree cover, as well as decreasing the potential for future incompatible land uses. digital.library.unt.edu/ark:/67531/metadc499998/
Effect of Retting on Surface Chemistry and Mechanical Performance Interactions in Natural Fibers for High Performance Polymer Composites
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Sustainability through replacement of non-renewable fibers with renewable fibers is an ecological need. Impact of transportation costs from South-east Asia on the life cycle analysis of the composite is detrimental. Kenaf is an easily grown crop in America. Farm based processing involves placing the harvested crop in rivers and ponds, where retting of the fibers from the plant (separation into fibers) can take 2 weeks or more. The objective of this thesis is to analyze industrially viable processes for generating fibers and examine their synergistic impact on mechanical performance, surface topography and chemistry for functional composites. Comparison has been made with commercial and conventional retting process, including alkali retting, enzymatic retting, retting in river and pond water (retting occurs by natural microbial population) with controlled microbial retting. The resulting kenaf fibers were characterized by dynamic mechanical analysis (DMA), Raman spectroscopy (FT-Raman), Fourier transform infrared spectroscopy (FT-IR), polarized optical microscopy (POM), X-ray photoelectron spectroscopy (XPS), Scanning electron microscopy (SEM) optical fluorescence microscopy, atomic force microscopy (AFM) and carbohydrate analysis. DMA results showed that pectinase and microbe treated fibers have superior viscoelastic properties compared to alkali retting. XPS, Raman, FT-IR and biochemical analysis indicated that the controlled microbial and pectinase retting was effective in removing pectin, hemicellulose and lignin. SEM, optical microscopy and AFM analysis showed the surface morphology and cross sectional architecture were preserved in pectinase retting. Experimental results showed that enzymatic retting at 48 hours and controlled microbial retting at 72 hours yield uniform and superior quality fibers compared to alkali and natural retting process. Controlled microbial retting is an inexpensive way to produce quality fibers for polymer composite reinforcement. digital.library.unt.edu/ark:/67531/metadc271883/
Effects of Quantum Coherence and Interference
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Quantum coherence and interference (QCI) is a phenomenon that takes place in all multi-level atomic systems interacting with multiple lasers. In this work QCI is used to create several interesting effects like lasing without inversion (LWI), controlling group velocity of light to extreme values, controlling the direction of propagation through non-linear phase matching condition and for controlling the correlations in field fluctuations. Controlling group velocity of light is very interesting because of many novel applications it can offer. One of the unsolved problems in this area is to achieve a slow and fast light which can be tuned continuously as a function of frequency. We describe a method for creation of tunable slow and fast light by controlling intensity of incident laser fields using QCI effects. Lasers are not new to the modern world but an extreme ultra-violet laser or a x-ray laser is definitely one of the most desirable technologies today. Using QCI, we describe a method to realize lasing at high frequencies by creating lasing without inversion. Role of QCI in creating correlations and anti-correlations, which are generated by vacuum fluctuations, in a three level lambda system coupled to two strong fields is discussed. digital.library.unt.edu/ark:/67531/metadc500094/
Electrochemically Deposited Metal Alloy-silicate Nanocomposite Corrosion Resistant Materials
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Zinc-nickel ?-phase silicate and copper-nickel silicate corrosion resistant coatings have been prepared via electrochemical methods to improve currently available corrosion resistant materials in the oil and gas industry. A layered silicate, montmorillonite, has been incorporated into the coatings for increased corrosion protection. For the zinc nickel silicate coatings, optimal plating conditions were determined to be a working pH range of 9.3 -9.5 with a borate based electrolyte solution, resulting in more uniform deposits and better corrosion protection of the basis metal as compared to acidic conditions. Quality, strongly adhering deposits were obtained quickly with strong, even overall coverage of the metal substrate. The corrosion current of the zinc-nickel-silicate coating is Icorr = 3.33E-6 for a borate based bath as compared to a zinc-nickel bath without silicate incorporation (Icorr = 3.52E-5). Step potential and direct potential methods were examined, showing a morphological advantage to step potential deposition. The effect of borate addition was examined in relation to zinc, nickel and zinc-nickel alloy deposition. Borate was found to affect the onset of hydrogen evolution and was examined for absorption onto the electrode surface. For copper-nickel silicate coatings, optimal conditions were determined to be a citrate based electrolytic bath, with pH = 6. The solutions were stable over time and strong adhering, compact particle deposits were obtained. The corrosion current of the copper-nickel-silicate coatings is Icorr = 3.86E-6 (copper-nickel coatings without silicate, Icorr = 1.78E-4). The large decrease in the corrosion current as the silicate is incorporated into the coating demonstrates the increase in corrosion resistance of the coatings with the incorporation of silicates. digital.library.unt.edu/ark:/67531/metadc271794/
Electrodeposition of Nickel and Nickel Alloy Coatings with Layered Silicates for Enhanced Corrosion Resistance and Mechanical Properties
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The new nickel/layered silicate nanocomposites were electrodeposited from different pHs to study the influence on the metal ions/layered silicate plating solution and on the properties of the deposited films. Nickel/layered silicate nanocomposites were fabricated from citrate bath atacidic pHs (1.6−3.0), from Watts’ type solution (pH ~4-5), and from citrate bath at basic pH (~9). Additionally, the new nickel/molybdenum/layered silicate nanocomposites were electrodeposited from citrate bath at pH 9.5. The silicate, montmorillonite (MMT), was exfoliated by stirring in aqueous solution over 24 hours. The plating solutions were analyzed for zeta potential, particle size, viscosity, and conductivity to investigate the effects of the composition at various pHs. The preferred crystalline orientation and the crystalline size of nickel, nickel/layered silicate, nickel/molybdenum, and nickel/molybdenum/layered silicate films were examined by X-ray diffraction. The microstructure of the coatings and the surface roughness was investigated by scanning electron microscopy and atomic force microscopy. Nickel/molybdenum/layered silicate nanocomposites containing low content of layered silicate (1.0 g/L) had increase 32 % hardness and 22 % Young’s modulus values over the pure nickel/molybdenum alloy films. The potentiodynamic polarization and electrochemical impedance measurements showed that the nickel/molybdenum/layered silicate nanocomposite layers have higher corrosion resistance in 3.5% NaCl compared to the pure alloy films. The corrosion current density of the nickel/molybdenum/layered silicate nanocomposite composed of 0.5 g/L MMT is 0.63 µA·cm-2 as compare to a nickel/molybdenum alloy which is 2.00 µA·cm-2. digital.library.unt.edu/ark:/67531/metadc699999/
Electronic Sound Analysis with Hardware System and Remote Internet Display
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Currently, standards from government agencies such as the National Institute for Occupation Safety and Health exist to aid in safeguarding individuals’ capacity for hearing, but only in factory settings in which large machines often produce loud levels of sound. Neglecting the fact that these preventative measures are only in place in the most limited of settings, no system currently exists to observe and report sound exposure levels in a manner timely or easily recognizable enough to adequately serve its purpose of hearing conservation. Musicians may also incur significant levels of risk for hearing loss in their day-to-day rehearsals and concerts, from high school marching bands to university wind bands. As a result, music school accrediting organizations such as the National Association of Schools of Music and even the European Union have begun taking steps meant to determine the risks associated with music. To meet these goals and improve upon current technologies, a system has been developed that electronically records sound levels utilizing modern hardware, increases the speed of reporting by transmitting data over computer networks and the Internet, and displays measures calculated from these data in a web browser for a highly viewable, user-friendly interface. digital.library.unt.edu/ark:/67531/metadc103358/
Electrostatic Effects in III-V Semiconductor Based Metal-optical Nanostructures
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The modification of the band edge or emission energy of semiconductor quantum well light emitters due to image charge induced phenomenon is an emerging field of study. This effect observed in quantum well light emitters is critical for all metal-optics based light emitters including plasmonics, or nanometallic electrode based light emitters. This dissertation presents, for the first time, a systematic study of the image charge effect on semiconductor–metal systems. the necessity of introducing the image charge interactions is demonstrated by experiments and mathematical methods for semiconductor-metal image charge interactions are introduced and developed. digital.library.unt.edu/ark:/67531/metadc115090/
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