Mechanical Properties of Polymer Modified Mortar

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The mechanical properties of the polymer-modified mortar are markedly improved over conventional cement mortar. We utilized recycled ABS in powder form and a polymer latex emulsion, polymer percentage ranges from 0 to 25 percent by polymer/cement ratio were investigated. The mechanical properties investigated were compression strength and adhesion strength. Compression strength effects did not have an impact on adhesion strength. Adhesion strength was calculated with pullout testing apparatus designed by the author. Results indicate that recycled ABS had a lower adhesive strength than the acrylic latex emulsion and the base mortar, but did increase in adhesive strength when mixed with maleic-anhydride. The adhesive strength was investigated for a Fiber Reinforced Polymer (FRP) made of an "E" glass fiber that is a continuous strand roving oriented and pre-tensioned longitudinally in an isopthalic polyester matrix material. The FRP rebar was compared to standard steel rebars, and found that the standard steel corrugated rebar had a higher adhesive strength, due to mechanical interlocking. This was clarified by measurements using a smooth steel rebar. Characterization of the polymer-modified mortar was conducted by pore analysis and scanning electron microscopy. Scanning Electron Microscopy was implemented to view the polymer particles, the cement fibrils formed by the …
Date: August 2002
Creator: Palos, Artemio
System: The UNT Digital Library

Investigations of Thermochemistry and the Kinetics of H Atom Radical Reactions

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The thermochemistry of several species, and the kinetics of various H atom radical reactions relevant to atmospheric and combustion chemistry were investigated using ab initio theoretical techniques and the flash photolysis / resonance fluorescence technique. Using ab initio quantum mechanical calculations up to the G3 level of theory, the C-H bond strengths of several alkanes were calculated. The bond strengths were calculated using two working reactions. From the results, it is apparent that the bond strengths decrease as methyl groups are added to the central carbon. The results are in good agreement with recent experimental halogenation kinetic studies. Hydrogen bond strengths with sulfur and oxygen were studied via CCSD(T) theory, together with extrapolation to the complete basis set limit. The results for the bond dissociation energies (ground state at 0 K, units: kJ mol-1) are: S-H = 349.9, S-D = 354.7, HS-H = 376.2, DS-D = 383.4, and HO-H = 492.6. These data compare well with experimental literature. The rate constants for the isotopic reactions of H + H2S, D + H2S, H + D2S, and D + D2S are studied at the QCISD(T)/6-311+G(3df,2p) level of theory. The contributions of the exchange reaction versus abstraction are examined through transition state …
Date: December 2002
Creator: Peebles, Lynda Renee
System: The UNT Digital Library

The Tone Clock: Peter Schat's System and an Application to His Etudes for Piano and Orchestra, Opus 39

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The scope of this study includes relevant background information on Peter Schat and his compositions and process, an explanation of the Tone Clock system and a detailed analysis of one of his compositions, the Etudes for Piano and Orchestra, Opus 39. The intent is to demonstrate how the Tone Clock naturally evolved from the practices of the Second Viennese School and how it relates to both new and existing modern music. The study is divided into five chapters. Chapter 1 presents a brief introduction to Peter Schat and the Tone Clock. Chapter 2 provides a more detailed biography of Peter Schat and traces the development and evolution of his compositional techniques, ultimately culminating in the Tone Clock. Chapter 3 provides a basic explanation of the Tone Clock itself, with demonstrations of various components through musical examples and illustrations. Chapter 4 is a detailed analysis of the Etudes for Piano and Orchestra, Opus. 39. Chapter 5 summarizes the results of the study, with special attention to the impact of the Tone Clock on performance from the perspective of the performer. The analysis of the Etudes was completed by using the Tone Clock as an analytical tool, aided by the composer's original …
Date: December 2002
Creator: Petrella, Diane Helfers
System: The UNT Digital Library

Gender and Desire in Thomas Lovell Beddoes' The Brides' Tragedy and Death's Jest-Book

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Thomas Lovell Beddoes' female dramatic characters are, for the most part, objectified and static, but these passive women perform a crucial narrative and thematic function in the plays. Alongside the destructive activity of the male characters, they dramatize masculine-feminine unions as idealized and contrived and, thus, unstable. Desire, power and influence, as well as the constrictive aspects of physicality, all become gendered concepts in Beddoes' plays, and socially normative relationships between men and women, including heterosexual courtship and marriage, are scrutinized and found wanting. In The Brides' Tragedy, Floribel and Olivia, the eponymous brides, represent archetypes of innocence, purity, and Romantic nature. Their bridegroom, Hesperus, embodies Romantic masculinity, desiring the feminine and aspiring to androgyny, but ultimately unable to relinquish masculine power. The consequences of Hesperus' attempts to unite with the feminine other are the destruction of that other and of himself, with no hope for the spiritual union in death that the Romantic Hesperus espouses as his ultimate desire. Death's Jest-Book expands upon the theme of male-female incompatibility, presenting heterosexual relationships in the context of triangulated desire. The erotic triangles created by Melveric, Sibylla, and Wolfram and Athulf, Amala, and Adalmar are inherently unstable, because they depend upon the …
Date: May 2002
Creator: Rees, Shelley S.
System: The UNT Digital Library

Monte Carlo simulation and experimental studies of the production of neutron-rich medical isotopes using a particle accelerator.

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The developments of nuclear medicine lead to an increasing demand for the production of radioisotopes with suitable nuclear and chemical properties. Furthermore, from the literature it is evident that the production of radioisotopes using charged-particle accelerators instead of nuclear reactors is gaining increasing popularity. The main advantages of producing medical isotopes with accelerators are carrier free radionuclides of short lived isotopes, improved handling, reduction of the radioactive waste, and lower cost of isotope fabrication. Proton-rich isotopes are the result of nuclear interactions between enriched stable isotopes and energetic protons. An interesting observation is that during the production of proton-rich isotopes, fast and intermediately fast neutrons from nuclear reactions such as (p,xn) are also produced as a by-product in the nuclear reactions. This observation suggests that it is perhaps possible to use these neutrons to activate secondary targets for the production of neutron-rich isotopes. The study of secondary radioisotope production with fast neutrons from (p,xn) reactions using a particle accelerator is the main goal of the research in this thesis.
Date: May 2002
Creator: Rosencranz, Daniela Necsoiu
System: The UNT Digital Library

Memories of Motherland: Gender, Diaspora and National Identity in 1990s Indian Popular Culture

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This thesis examines the role of globalization, an open economy and diasporic experiences on the 1990s popular Indian culture, focusing on discourses of gender, national identity and family. Recent Indian beauty queens and international beauty contests are discussed in the context of gendered nationhood in 1990s India. Several popular films of the 1990s are discussed as narratives expressing longing for an extended family and a homogeneous national identity under the leadership of a traditional father figure. In contrast, independent films interrogate the primacy of ethnic and national identity and raise interesting questions about exilic experience. All of these forms of national and popular culture reflect the conflicting and ever-changing anxieties surrounding national identity and the role of women in India.
Date: May 2002
Creator: Sapre, Manasi
System: The UNT Digital Library

The Effects of Reinforcing Operant Variability on Task Acquisition

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Neuringer, Deiss, and Olson (2000) was replicated and extended to determine the effect of variability contingencies on task acquisition for twelve 7-9 year old children. Subjects first learned to press a computer's shift keys with increasing response variation. Each subject was then exposed to one of three experimental conditions during which they received a point for target responses. Variability condition subjects received additional points on a variable interval schedule for nontarget responses occurring less than 3% of the time. The any condition subjects received additional points on a variable interval schedule for any nontarget response. Control subjects received points only for target responses. All variability condition and two control subjects learned the target response. All any condition subjects and two control subjects did not.
Date: December 2002
Creator: Seymour, Kail H.
System: The UNT Digital Library

London, Ankara, and Geneva: Anglo-Turkish Relations, The Establishment of the Turkish Borders, and the League of Nations, 1919-1939

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This dissertation asserts the British primacy in the deliberations of the League of Nations Council between the two world wars of the twentieth century. It maintains that it was British imperial policy rather than any other consideration that ultimately carried the day in these deliberations. Given, as examples of this paramountcy, are the discussions around the finalization of the borders of the new republic of Turkey, which was created following the collapse of the Ottoman Empire at the end of the First World War. These discussions focused on three areas, the Mosul Vilayet or the Turco-Iraqi frontier, the Maritza Delta, or the Turco-Greek frontier, and the Sanjak of Alexandretta or the Turco-Syrian frontier.
Date: August 2002
Creator: Stillwell, Stephen J.
System: The UNT Digital Library

Fabrication of MOS capacitor and transitor structure using contact photolithography.

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This problem in lieu of thesis report describes a practical photolithographic method to produce micro patterns on metal-oxide-semiconductor or metal-oxide-semiconductor-metal layers for electrical measurements. The desired patterns are then transferred from the photo mask to the photoresist-coated metal film by exposure, followed by wet etching. In the procedure described in this report, it was observed that microstructures as small as 27 mm with an edge roughness of ~ 2 mm can be reproducibly generated with this process. MOS capacitors and transistors structures can be fabricated by using this technique. The method described in this report requires access to only simple facilities so that it is relatively inexpensive, and the overall time required for the whole process is short.
Date: August 2002
Creator: Su, Danni
System: The UNT Digital Library

Computer Crime as a Barrier to Electronic Commerce: New Solutions for Public Law Enforcement.

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Electronic commerce was expected to grow exponentially, but the actual rate of growth in recent years has been disappointing. Recent surveys of perceptions of the development of electronic commerce clearly focus our attention on the perception and fear of computer crime as the major cause of this disappointing growth pattern. The thesis critiques existing private law solutions to this problem and argues from a normative theory on “the commons” for the application of new public law enforcement solutions in the public trust, sanctions, and public coproduction of order. The thesis argues that given the failures of existing private law solutions to the problem, these public law enforcement solutions should be more effective, efficient, and more satisfactory.
Date: August 2002
Creator: Temur, Nuri
System: The UNT Digital Library

Developmental Stressors and Associated Coping Skills in the Development of Disordered Eating in College Females

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There is a lack of clarity in the current literature in how potential etiological factors interact and result in disordered eating. The purpose of this study was to examine an expanded model of Personality, Social Support, Appraisal/Coping Processes, Abuse History, Internalization of Sociocultural Standards, Psychological Disturbances, and Body Disparagement in the development of disordered eating. The current model was evaluated using 276 women in their transition to college, a time period highly associated with symptoms believed to increase a woman's risk for the development of disordered eating including perceived difficulty coping, weight gain, and negative affect. Structural equation modeling was used to allow simultaneous examination of the causal relationships between the factors. Structural analyses confirmed that college women with previous stressful experiences appraised the adjustment to college as more stressful and reported feeling less able to cope with the transition. Those women who identified the transition as overwhelming were also aware of increased negative mood and psychological states since beginning the school semester. Further, women with previous traumatic sexual experiences appeared to be at additional risk for increased negative affective symptoms. The resulting model confirmed that those women who experience negative mood states and those that endorse strong internalization of …
Date: August 2002
Creator: Tripp, Margaret Murphy
System: The UNT Digital Library

Implementation of Scalable Secure Multicasting

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A large number of applications like multi-player games, video conferencing, chat groups and network management are presently based on multicast communication. As the group communication model is being deployed for mainstream use, it is critical to provide security mechanisms that facilitate confidentiality, authenticity and integrity in group communications. Providing security in multicast communication requires addressing the problem of scalability in group key distribution. Scalability is a concern in group communication due to group membership dynamics. Joining and leaving of members requires the distribution of a new session key to all the existing members of the group. The two approaches to key management namely centralized and distributed approaches are reviewed. A hybrid solution is then provided, which represents a improved scalable and robust approach for a secure multicast framework. This framework then is implemented in an example application of a multicast news service.
Date: August 2002
Creator: Vellanki, Ramakrishnaprasad
System: The UNT Digital Library

A Study of Perceptually Tuned, Wavelet Based, Rate Scalable, Image and Video Compression

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In this dissertation, first, we have proposed and implemented a new perceptually tuned wavelet based, rate scalable, and color image encoding/decoding system based on the human perceptual model. It is based on state-of-the-art research on embedded wavelet image compression technique, Contrast Sensitivity Function (CSF) for Human Visual System (HVS) and extends this scheme to handle optimal bit allocation among multiple bands, such as Y, Cb, and Cr. Our experimental image codec shows very exciting results in compression performance and visual quality comparing to the new wavelet based international still image compression standard - JPEG 2000. On the other hand, our codec also shows significant better speed performance and comparable visual quality in comparison to the best codec available in rate scalable color image compression - CSPIHT that is based on Set Partition In Hierarchical Tree (SPIHT) and Karhunen-Loeve Transform (KLT). Secondly, a novel wavelet based interframe compression scheme has been developed and put into practice. It is based on the Flexible Block Wavelet Transform (FBWT) that we have developed. FBWT based interframe compression is very efficient in both compression and speed performance. The compression performance of our video codec is compared with H263+. At the same bit rate, our encoder, …
Date: May 2002
Creator: Wei, Ming
System: The UNT Digital Library

The Solo Compositions for Trumpet of Fisher Aubrey Tull: An Analysis of Structural, Technical, and Stylistic Elements for Performance Preparation, with Three Recitals of Selected Works by Bozza, Fasch, Haydn, Tomasi, and Others

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The compositions of Fisher Aubrey Tull are widely performed and many have become standard repertoire. Tull's compositions encompass a multiplicity of performance media including works for orchestra, chorus, symphonic band, jazz band, brass choir, and solo and chamber works. Tull's compositional output for the trumpet is prolific and is acknowledged to be music of high quality. An examination of Trumpet and Brass Programs, compiled and published annually by the International Trumpet Guild, shows Tull's solo and ensemble works for trumpet to be frequently performed. Furthermore, his compositions for trumpet have been performed and recorded by internationally acclaimed artists including Vincent DiMartino, Terry Everson, Håkan Hardenberger, Anthony Plog, Carl "Doc" Severinsen and Allen Vizzutti.This study investigates Fisher Tull's eight solo works for trumpet, which include: Vignette for Trumpet and Piano (1954); Concerto No. 1 for Trumpet and Orchestra (1964); Concerto No. 2 for Trumpet and Band (1974); Three Bagatelles for Trumpet and Piano (1975); Eight Profiles for Solo Trumpet (1978); Rhapsody for Trumpet and Band (1980); Sonata for Trumpet and Piano (1986); and Chromutations for Solo Trumpet (1988). Histories of each composition are chronicled. An analysis of formal organization and significant style features examines musical structure, harmonic language, rhythmic character, instrumentation, …
Date: August 2002
Creator: Wenger, Alan J.
System: The UNT Digital Library

Tiger; a stage play, and a reflective essay detailing the writing process

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This thesis includes a full length play and a separate section describing the creation of this play. The play depicts family members struggling with the direct and indirect ramifications of alcoholism, depression, and suicide. The play is composed of two acts; act one contains eight scenes, and act two contains six scenes. It is set in the 1950s and 1960s and takes place in various areas of the family home, at a wedding reception, and at a funeral. The essay section includes a description of the process, a record of changes in the play's direction, notations of personal discoveries, and a self evaluation of the strengths and weaknesses of the play.
Date: August 2002
Creator: Westkaemper, Lisa
System: The UNT Digital Library

Application of Thermomechanical Characterization Techniques to Bismuth Telluride Based Thermoelectric Materials

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The thermoelectric properties of bismuth telluride based thermoelectric (TE) materials are well-characterized, but comparatively little has been published on the thermomechanical properties. In this paper, dynamic mechanical analysis (DMA) and differential scanning calorimetry data for bismuth telluride based TE materials is presented. The TE materials' tan delta values, indicative of viscoelastic energy dissipation modes, approached that of glassy or crystalline polymers, were greater than ten times the tan delta of structural metals, and reflected the anisotropic nature of TE materials. DMA thermal scans showed changes in mechanical properties versus temperature with clear hysteresis effects. These results showed that the application of DMA techniques are useful for evaluation of thermophysical and thermomechanical properties of these TE materials.
Date: August 2002
Creator: White, John B.
System: The UNT Digital Library

Characterization of cDNA and Genomic Clones for a Palmitoyl-acyl Carrier Protein Thioesterase and an Osmotin-Like PR5 Protein in Gossypium Hirsutum.

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Putative cotton cDNA clones and cognate genomic clones for a palmitoyl-acyl carrier protein (ACP) thioesterase (PATE) and an osmotin-like pathogenesis-related 5 (PR5) protein have been isolated and characterized. PATE is a class B fatty acid thioesterase with specificity for saturated long-chain fatty acids such as palmitate, and is implicated as a key enzyme to be targeted for regulation of fatty acid synthesis in order to alter cotton seed oil profiles. A nearly full-length 1.7-kb cDNA clone was isolated using a hybridization probe derived from an Arabidopsis PATE cDNA clone designated TE 3-2. A 17-kb genomic segment encompassing the PATE gene was also isolated, which has six exons and five introns with high sequence identity with other FatB cDNA/gene sequences. The deduced PATE preprotein amino acid sequence of 413 residues has putative signal sequences for targeting to the chloroplast stroma. PR5 proteins called osmotins are made in response to fungal pathogen stress or osmotic stress (water deprivation or salt exposure). Osmotins may actually form pores in fungal membranes, leading to osmotic rupture and destruction of the fungal cells. A cotton osmotin-like PR5 cDNA insert of 1,052 base-pairs was isolated and shown to encode a preprotein of 242 amino acids and is …
Date: May 2002
Creator: Yoder, David W.
System: The UNT Digital Library