UNT Theses and Dissertations - 358 Matching Results

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Baeyer-Villiger Oxidation of 1,7- & 1,9-dibromopentacyclo[5.4.0.02,6.03,10.05,9]undecane-8,11-dione

Description: Baeyer-Villiger oxidation of 1,9-dibromopentacyclo[5.4.0.02,6.03,10.05,9]undecane-8,11-dione (1,9-dibromo-PCU-8,11-dione) was performed by using an excess amount of m-chloroperbenzoic acid (3 equivalents) and resulted in the formation of the corresponding monolactone. The reaction would not proceed to the dilactone stage. The structure of the reaction product was established unequivocally via single crystal X-ray diffraction. Baeyer-Villiger oxidation of 1,9-dibromo-PCU-8,11-dione using ceric ammonium nitrate (CAN) was also performed and afforded a mixture of lactones. Only one of these lactones, which also contained an alkene functionality, could be isolated and characterized. 1,7-dibromo-PCU-8,11-dione was also reacted with CAN, yielding the mono-lactone, which has also been characterized.
Date: May 2004
Creator: Akinola, Adeniyi O.
Partner: UNT Libraries

Comparison and Evaluation of Existing Analog Circuit Simulator using Sigma-Delta Modulator

Description: In the world of VLSI (very large scale integration) technology, there are many different types of circuit simulators that are used to design and predict the circuit behavior before actual fabrication of the circuit. In this thesis, I compared and evaluated existing circuit simulators by considering standard benchmark circuits. The circuit simulators which I evaluated and explored are Ngspice, Tclspice, Winspice (open source) and Spectre® (commercial). I also tested standard benchmarks using these circuit simulators and compared their outputs. The simulators are evaluated using design metrics in order to quantify their performance and identify efficient circuit simulators. In addition, I designed a sigma-delta modulator and its individual components using the analog behavioral language Verilog-A. Initially, I performed simulations of individual components of the sigma-delta modulator and later of the whole system. Finally, CMOS (complementary metal-oxide semiconductor) transistor-level circuits were designed for the differential amplifier, operational amplifier and comparator of the modulator.
Date: December 2006
Creator: Ale, Anil Kumar
Partner: UNT Libraries

Iconoclast in the mirror.

Description: This work explores identity positions of speakers in modern and contemporary poetry with respect to themes of subjectivity, self-awareness, lyricism, heteroglossia, and social contextualization, from perspectives including Bakhtinian, queer, feminist and postructuralist theories, and Peircian semiotics. Tony Hoagland, W.H. Auden, Adrienne Rich, and the poetic prose of Hélène Cixous provide textual examples of an evolving aesthetic in which the poet's self and world comprise multiple dynamic, open relationships supplanting one in which simple correspondences between signifiers and signifieds define selves isolated from the world. Hypertext and polyamory serve as useful analogies to the semantic eros characteristic of such poetry, including the collection of original poems that the critical portion of this thesis introduces.
Date: August 2005
Creator: Alexander, Lydia L.
Partner: UNT Libraries

An Examination of Methodological Rigor and Its Effects on Organizational Development and Change Outcomes

Description: Organizational development and change (ODC) is a broad field because change occurs in all organizations, occurs at multiple organizational levels, consists of numerous interventions, and can impact multiple outcomes. Many ODC efforts attempt to examine the effectiveness of their initiatives, yet fail to account for the quality, or rigor of their methods. The purpose of this paper is to examine how methodological rigor and intervention implementation quality impact ODC outcomes. The results indicate that overall methodological rigor is not a significant predictor of organizational change outcomes; however, several individual rigor criteria exhibit predictive power. Implementation quality is a significant predictor of organizational outcomes, but in a negative direction.
Date: May 2005
Creator: Alexander, Sandra G.
Partner: UNT Libraries

Novel Role of Trypsin in Zebrafish

Description: It has been shown previously in our laboratory that zebrafish produce trypsin from their gills when they are under stress, and this trypsin is involved in thrombocyte activation via PAR2 during gill bleeding. In this study, I investigated another role of the trypsin that is secreted from zebrafish. This investigation has demonstrated a novel role of trypsin in zebrafish. Not only did this investigation demonstrate the role of trypsin in zebrafish behavior, but also it showed that PAR2 might be the receptor that is involved in trypsin-mediated behavioral response. In addition, we have shown that Gq and ERK inhibitors are able to block the trypsin pathway and prevent the escaping behavior. Finally, the results of this investigation suggest that the cells that respond to trypsin are surface cells, which have an appearance similar to that of neuromast cells.
Date: May 2013
Creator: Alsrhani, Abdullah Falleh
Partner: UNT Libraries

Improving the Gameplay Experience and Guiding Bottom Players in an Interactive Mapping Game

Description: In game based learning, motivating the players to learn by providing them a desirable gameplay experience is extremely important. However, it's not an easy task considering the quality of today's commercial non-educational games. Throughout the gameplay, the player should neither get overwhelmed nor under-challenged. The best way to do so is to monitor the player's actions in the game because these actions can tell the reason behind the player's performance. They can also tell about the player's lacking competencies or knowledge. Based on this information, in-game educational interventions in the form of hints can be provided to the player. The success of such games depends on their interactivity, motivational outlook and thus player retention. UNTANGLED is an online mapping game based on crowd-sourcing, developed by Reconfigurable Computing Lab, UNT for the mapping problem of CGRAs. It is also an educational game for teaching the concepts of reconfigurable computing. This thesis performs qualitative comparative analysis on gameplays of low performing players of UNTANGLED. And the implications of this analysis are used to provide recommendations for improving the gameplay experience for these players by guiding them. The recommendations include strategies to reach a high score and a compact solution, hints in the form of preset patterns and a clustering based approach.
Date: May 2017
Creator: Ambekar, Kiran
Partner: UNT Libraries

Integrating life cycle analysis and the ecological footprint calculator to foster sustainable behaviors

Description: Many tools have been developed to assess global, national or regional sustainable development policies. However, as governments develop sustainable policies, individuals must also feel empowered to affect their personal impact on the planet. This thesis integrates three sustainability concepts that lend themselves to individual sustainability: The natural step, life cycle assessment, and the ecological footprint. TNS serves to provide the meaning and substance toward sustainable development. LCA helps provide the framework for assessing sustainability. The EF calculator determines the driving components and measures the qualitative decisions made through TNS and LCA. From the analysis of the household footprint calculator a simplified footprint calculator was developed to assist individuals and communities in setting benchmarks and goals as they move away from over-consumption and towards a sustainable lifestyle.
Date: December 2002
Creator: Anderle, Kathryn
Partner: UNT Libraries

Stretched Out On Her Grave: The Evolution of a Perversion

Description: The word "necrophilia" brings a particular definition readily to mind – that of an act of sexual intercourse with a corpse, probably a female corpse at that. But the definition of the word did not always have this connotation; quite literally the word means "love of the dead," or "a morbid attraction to death." An examination of nineteenth-century literature reveals a gradual change in relationships between the living and the dead, culminating in the sexualized representation of corpses at the close of the century. The works examined for necrophilic content are: Mary Wollstonecraft’s Mary, A Fiction, Mary Shelley’s Frankenstein, Emily Brontë’s Wuthering Heights, and Bram Stoker’s Dracula and The Jewel of Seven Stars.
Date: August 2000
Creator: Angel-Cann, Lauryn
Partner: UNT Libraries

Barriers Limiting Access to Hospice Care for Elderly African Americans in Amarillo, Texas

Description: This study examines barriers limiting access to hospice care for elderly African Americans. Ethnic background plays a critical role in the development of attitudes, beliefs and expectations related to death and issues surrounding hospice care. The purpose of this study was to identify barriers that may limit access to hospice care for African Americans. A questionnaire was administered to 56 elderly African Americans in three religious settings and an African American senior citizens center. The questionnaire was designed to obtain information concerning African Americans' attitudes toward death and dying; religious beliefs; health beliefs; familiarity with hospice and prospective use of hospice. The results of the study indicate a number of barriers in access to hospice care for African Americans including: hospice knowledge barriers; education/outreach barriers; cultural knowledge barriers related to death/dying values; family/social support barriers; hospice organizational/provider barriers; health care organizational/provider barriers; and reimbursement barriers.
Date: August 2001
Creator: Anthony, Tomagene
Partner: UNT Libraries

Evaluation of virulence in wild type and pyrimidine auxotrophs of Pseudomonas aeruginosa using the eukaryotic model system Caenorhabditis elegans.

Description: The human opportunistic pathogen, Pseudomonas aeruginosa PAO1, has been shown to kill the nematode Caenorhabditis elegans. C. elegans has been a valuable model for the study of bacterial pathogenesis, and has reinforced the notion that common virulence and host defense mechanisms exist. Recently, the pyrimidine pathway was shown to regulate virulence levels. Therefore, mutations in the pyrimidine pathway of PAO1 showed decrease virulence in the nematode. When starving the nematode, bacterial resistance was also shown to increase. It was hypothesized that starvation induced the DAF pathway, which regulates the transcription of genes involved with the antibacterial defense mechanism. Further research will be conducted to test this theory by performing RNAi experiments for the genes functioning in the antibacterial defense mechanism.
Date: August 2004
Creator: Anvari, Sara
Partner: UNT Libraries

Inquiry-based science for high school students: a forensic unit

Description: This project constitutes an instructional unit for honors biology that involves the use of science in the field of criminal investigation and forensics. Before beginning the unit, the learners should have mastered basic laboratory skills, including use of the microscope. They should also have an understanding of the basic structure and function of DNA and its role in heredity and protein synthesis. The standard time frame is 24 days with 70-minute periods, but can be easily adjusted to meet classroom needs. Several instructional strategies enhance student learning and make science fun. The unit is inquiry-driven and activity-based. Students are surprised by the crime, gather and analyze evidence, and work towards proposing an explanation. This real world problem involves the use of cooperative learning and a variety of assessment techniques.
Date: August 2000
Creator: Apple, Kendra Kea
Partner: UNT Libraries

Development of a Coaxiality Indicator

Description: The geometric dimensioning and tolerancing concept of coaxiality is often required by design engineers for balance of rotating parts and precision mating parts. In current practice, it is difficult for manufacturers to measure coaxiality quickly and inexpensively. This study examines feasibility of a manually-operated, mechanical device combined with formulae to indicate coaxiality of a test specimen. The author designs, fabricates, and tests the system for measuring coaxiality of holes machined in a steel test piece. Gage Repeatability and Reproducibility (gage R&R) and univariate analysis of variance is performed in accordance with Measurement System Analysis published by AIAG. Results indicate significant design flaws exist in the current configuration of the device; observed values vary greatly with operator technique. Suggestions for device improvements conclude the research.
Date: December 1999
Creator: Arendsee, Wayne C.
Partner: UNT Libraries

The Apologist Tradition: A Transitional Period in Southern Proslavery Thought, 1831-1845

Description: Early antebellum defenders of slavery acknowledged that slavery created problems for southern society. They contended, however, that slave society was better and more natural than other forms of social organization. Thomas R. Dew, William Harper, and James Henry Hammond each expressed a social philosophy in which slavery had a crucial role in preserving social order. They argued from the basis of social organicism, the idea that society should have an elite that controlled the masses. For all three men, slavery represented a system of order that helped balance the dangers of democracy. Significantly, however, all three men recognized that the slave system was not perfect, and despite their defense of slavery, argued that it was a human institution and therefore corruptible.
Date: December 2000
Creator: Austin, Clara
Partner: UNT Libraries

A model for designing a new telecommunication system in Mongolia

Description: The objective of this research is to design, and determine the feasibility of, a telecommunication system for the city of Erdenet, Mongolia. The Mongolian Telecommunication Company, Telecommunication Company of Erdenet city, and the National Statistical Office of Mongolia provided the data required for telecommunication forecasting of Erdenet. The literature review and analysis of the telecommunication forecasting indicate the need for a model of a new Telecommunication system in Erdenet, Mongolia. The model, as indicated, should become a useful example for planning and updating the telecommunication system in Mongolia. The design of a proposed telecommunication network involves the following considerations: analyzing and forecasting telephone traffic, calculating the required number of channels, determining exchange locations, traffic matrix, and establishing a basic hierarchical structure.
Date: May 2001
Creator: Baatarjav, Enkhbat
Partner: UNT Libraries

Personality Correlates of Eating Disorder Symptomatology in a Nonclinical Sample of Female Undergraduates

Description: Research indicates the existence of an eating disorder continuum. The two-component model of disordered eating suggests that certain personality traits may increase an individual's vulnerability to develop more severe variants of disordered eating symptomatology. The present study investigates pre-clinical elevations on a measure of personality based on the Five-Factor Model (FFM) and pre-clinical elevations on a measure of eating disorder symptomatology in a sample of nonclinical undergraduates. The personality dimensions Neuroticism, Extraversion, and Agreeableness accounted for 7% of the variability in Body Dissatisfaction. Subcomponents comprising the personality dimensions of the FFM as determined by Saucier (1998) (see Appendix A) were analyzed. The Self-Reproach and Intellectual Interests subcomponents were the strongest predictors of Drive for Thinness and Body Dissatisfaction. The subcomponent Sociability was the strongest predictor of Bulimia. Findings present implications for prevention and treatment interventions. Longitudinal studies are needed to determine the temporal directionality of personality and disturbed eating.
Date: May 2003
Creator: Baker, Kristine Genovese
Partner: UNT Libraries

Effect of Surface Treatment on the Performance of CARALL, Carbon Fiber Reinforced Aluminum Joints

Description: Fiber-metal laminates (FML) are the advanced materials that are developed to improve the high performance of lightweight structures that are rapidly becoming a superior substitute for metal structures. The reasons behind their emerging usage are the mechanical properties without a compromise in weight other than the traditional metals. The bond remains a concern. This thesis reviews the effect of pre-treatments, say heat, P2 etch and laser treatments on the substrate which modifies the surface composition/roughness to impact the bond strength. The constituents that make up the FMLs in our present study are the Aluminum 2024 alloy as the substrate and the carbon fiber prepregs are the fibers. These composite samples are manufactured in a compression molding process after each pre-treatment and are then subjected to different tests to investigate its properties in tension, compression, flexural and lap shear strength. The results indicate that heat treatment adversely affects properties of the metal and the joint while laser treatments provide the best bond and joint strength.
Date: August 2017
Creator: Bandi, Raghava
Partner: UNT Libraries

Application of Cyclic Polarization of Aluminum 3003 Used in All-Aluminum Microchannel Heat Exchangers

Description: All-aluminum microchannel heat exchangers are designed to significantly reduce refrigerant charge requirements, weight, reduced brazed joints, and decreased potential for leakage by increasing reliability. Al 3003 alloy is corrosion resistant and can be formed, welded, and brazed but the issue with all-aluminum heat exchangers is localized corrosion (pitting) in corrosive environments. Currently, there is no universally accepted corrosion test that all coil manufacturers use to characterize their products. Electrochemical testing method of cyclic polarization was employed in this investigation and relevant parameters including electrolyte corrosive agent and its concentration, electrolyte pH, and applied potential scan rate was varied to find an optimal set of parameters. Results of cyclic polarization of Al 3003 in electrolytes containing various concentrations of NaCl were compared with those of the tests in Sea Water Acidified Accelerated Test (SWAAT) electrolyte and it is shown the SWAAT electrolyte (4.2% sea salt acidified to pH of 2.9) is by far stronger (in terms of corrosivity) than typical 3.5% NaCl solution used in most corrosion testing. Corrosion rates (g/m2yr) of Al 3003 measured in this investigation were comparable to those provided by ISO 9223 standard corresponding to C1 through CX categories. Duration of cyclic polarization test is much shorter than that of SWAAT and results obtained in this test is more reproducible compared to those of SWAAT. Scanning electron microscopy micrographs show typical pit depths of about 50 μm.
Date: May 2015
Creator: Barnes, Javier
Partner: UNT Libraries

Organizational development: A comparison of individual and organizational level change.

Description: Organizational change and development (OCD) has been studied by researchers to identify the effectiveness of change initiatives. Because of the broad scope of interventions in OCD, these studies have covered a range of areas including multiple interventions and the methodological rigor used by researchers. However, few have looked at organizational versus individual change within an organization, to examine whether individual change is more effective than organizational change. The purpose of this study is to determine if organizational change occurs in a top down or bottom up manner. A meta-analysis was conducted using 238 field experiments. Each study was coded for intervention and organizational outcome and for individual or organizational level variables. Effect sizes were calculated for each study, each level, and each level by intervention and outcome measure. Results indicate that while OCD interventions overall had a moderate effect size, the level of intervention or outcome was not a moderating variable.
Date: August 2005
Creator: Barnett, Michelle L.
Partner: UNT Libraries

James Earl Rudder: A Lesson in Leadership

Description: This thesis is the about the life of Rudder. The emphasis of this work, however, is that Rudder was successful primarily because of his character and leadership style. Much of the study was drawn from primary sources. Secondary sources were also consulted. This thesis opens with a brief Introduction, which discusses the need for this work. Chapter 1 discusses Rudder's life prior to WW II, emphasizing particular characteristics that benefited his leadership ability. Chapter 2 examines the 2nd Ranger Battalion's transformation under Rudder's leadership and guidance. Chapter 3 chronicles the 2nd Ranger Battalion's assault on the Pointe du Hoc battery, ending in December 1944, when Col. Rudder was reassigned to the 109th Infantry Regiment. Moreover, the controversy surrounding the Ranger's mission is also examined in this chapter. Chapter 4 describes Col. Rudder's leadership with the 109th in the Battle of the Bulge. A chapter accounting Rudder's political career and leadership follows. Chapter 6 examines his term as chancellor and president of the Texas A&M University system, until his death in 1970, and the major institutional changes that he enacted during his tenure, which resulted in A&M becoming the respected research university it is today. This significance and recapitulation of Rudder's life and leadership will follow in the Conclusion.
Date: December 2003
Creator: Bean, Christopher B.
Partner: UNT Libraries

"Second Life, Second Chance"

Description: This is a collection of two stories, one fiction and one non-fiction, in communication with one another. Both stories explore how trauma can transform a life. In "Tabula Rasa," Mena is unable to recall her past after being beaten and left for dead. She must choose whether to uncover her past or forget it and move forward with her life. Set in a town run by witches, Mena learns that both choices are dangerous. In "Eternal Second," the narrator recounts the aftermath of her husband's suicide. She explores how trauma invades all aspects of her life. In both stories, women must navigate a new life created by the destruction of the old one.
Date: August 2017
Creator: Beattie, Jessica Kathrine
Partner: UNT Libraries

Reflections of Other/Reflections of Self

Description: This Thesis collection contains a critical preface and five stories. The preface, “Reflejos y Reflexiones” (translated: Images and Thoughts), addresses the issues of writing the cultural or gendered Other; these issues include methodology, literary colonialism, a dialogue between works, and creating distance through defamiliarizing the self. “Perennials” is the story of Noemi Tellez, an immigrant to the U.S. who must choose between working and taking care of her family. In “Load Bearing” Luis, the eldest child, faces his family and friends on one of his last days before moving away to college. “La Monarca” deals with Lily's, the youngest daughter, struggle to mediate a place between her friends and her family. In “Reflections in the River,” Arabela, the second youngest, faces the ghost of an unwanted pregnancy and La Llorona. “La Cocina de Su Madre” is the story of Magda, the oldest daughter, and her own teenage girl, Natalia, as they attempt to find themselves in a new town after moving a thousand miles from home.
Date: August 2002
Creator: Bebout, Lee
Partner: UNT Libraries

A morphological study of the avian (Gallus domesticus) ductus arteriosi during hatching.

Description: The ductus arteriosi (DA) are two blood vessels connecting the pulmonary arteries to the descending aorta in the avian embryo. Following hatching, the DA closes, separation of the systemic and pulmonary circulation. I present the morphological changes that occur in the chicken DA during prepipping, internal pipping, external pipping, and hatching. The avian DA consists of two distinct tissue types, a proximal and a distal portion. Histological examination shows developmental differences between the proximal and distal portions of the DA with regard to lumen occlusion, endothelial cells, smooth muscle and elastin. Endothelial cell proliferation begins to occur as early as external pipping, with the lumen almost completely occluded by the 3rd day of post-hatching life. Expression of vascular endothelial growth factor (VEGF) increases in avian endothelial cells during hatching. I provide a morphological timeline of changes in the DA as the chicken develops from embryo to hatchling.
Date: May 2006
Creator: Belanger, Candace
Partner: UNT Libraries

Evidentiary Value of Condoms: Comparison of Durable Physical and Chemical Characteristics of Condoms

Description: Condom trace evidence must not be overlooked in sexual assault cases; understanding the chemical and physical characteristics of condoms is imperative if condoms are to be useful evidence. Previous research shows that condom identification is possible, but it is equally important to evaluate durability of condom residues versus time. Using FT-IR, this study examined vaginal swabs from subjects who self-sampled at intervals for up to 72 hours after having intercourse with a condom. This study investigated whether age and the stage of the menstrual cycle affected the durability of residues in the vagina over time. This study revealed that condoms containing nonoxynol-9, silicone-based lubricants, and particulates provide valuable information for identification, and that nonoxynol-9 specifically withstands the vaginal environment for up to 72 hours. Additionally, age and menstrual cycle both appeared to have an effect on the durability of residues although larger sample size is desirable.
Date: May 2000
Creator: Belcher, Kelly Leigh
Partner: UNT Libraries

Documentary Film: Access Denied

Description: Sculptor Eric McGehearty incorporates dyslexia, a learning disability, into his artwork to express his challenges with his limited ability to recognize and understand the written word. The film Access Denied focuses on Eric and his disability. Recognized in 1896, dyslexia has been studied and researched by scientists and educators. New assistive technology is now available to aid dyslexics in reading and writing. Specialized schools provide techniques to improve student learning. However, some options are not readily available to the general public; therefore, information about how to deal with the disability is not easily accessed. The aims of this documentary are to raise awareness of available resources to assist with learning as well as to demonstrate a relationship between art and dyslexia.
Date: August 2006
Creator: Bell, Leah Helanie
Partner: UNT Libraries