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Hybrid Nanocomposites for Bolometer Applications (open access)

Hybrid Nanocomposites for Bolometer Applications

Undergraduate thesis studying the properties of amorphous silicon (⍺-Si) and crystalline silicon nanowires (c-Si NWs), focusing on the requirements placed on thin films by bolometers.
Date: May 1, 2013
Creator: Cook, Andrew
System: The UNT Digital Library
Criticisms of Patriarchy in Women's Captivity Narratives: A Close Look at Mary Rowlandson's The Sovereignty and Goodness of God (1862) and Sarah Wakefield's Six Weeks in the Sioux Tepees: A Narrative of Indian Captivity (1862) (open access)

Criticisms of Patriarchy in Women's Captivity Narratives: A Close Look at Mary Rowlandson's The Sovereignty and Goodness of God (1862) and Sarah Wakefield's Six Weeks in the Sioux Tepees: A Narrative of Indian Captivity (1862)

Undergraduate thesis exploring criticisms of patriarchy in women's captivity narratives by examining Mary Rowlandson's The Sovereignty and Goodness of God (1862) and Sarah Wakefield's Six Weeks in the Sioux Tepees: A Narrative of Indian Captivity (1862). Both used their socially acceptable roles in order to assert their own ideas regarding the patriarchy. The author concludes that both narratives therefore assert that patriarchal societies did not necessarily produce justice for English or American women who were a part of these societies, or for the Dakota Indians who lived in close contact with a patriarchal society.
Date: May 3, 2013
Creator: Hansard, Chelsea
System: The UNT Digital Library
Multitasking mesoporous nanomaterials for biorefinery applications (open access)

Multitasking mesoporous nanomaterials for biorefinery applications

Mesoporous silica nanoparticles (MSNs) have attracted great interest for last two decades due to their unique and advantageous structural properties, such as high surface area, pore volume, stable mesostructure, tunable pore size and controllable particle morphology. The robust silica framework provides sites for organic modifications, making MSNs ideal platforms for adsorbents and supported organocatalysts. In addition, the pores of MSNs provide cavities/ channels for incorporation of metal and metal oxide nanoparticle catalysts. These supported metal nanoparticle catalysts benefit from confined local environments to enhance their activity and selectivity for various reactions. Biomass is considered as a sustainable feedstock with potential to replace diminishing fossil fuels for the production of biofuels. Among several strategies, one of the promising methods of biofuel production from biomass is to reduce the oxygen content of the feedstock in order to improve the energy density. This can be achieved by creating C-C bonds between biomass derived intermediates to increase the molecular weight of the final hydrocarbon molecules. In this context, pore size and organic functionality of MSNs are varied to obtain the ideal catalyst for a C-C bond forming reaction: the aldol condensation. The mechanistic aspects of this reaction in supported heterogeneous catalysts are explored. The …
Date: May 2, 2013
Creator: Kandel, Kapil
System: The UNT Digital Library
Synthesis of heterocycles: Indolo (2,1-a) isoquinolines, renewables, and aptamer ligands for cellular imaging (open access)

Synthesis of heterocycles: Indolo (2,1-a) isoquinolines, renewables, and aptamer ligands for cellular imaging

In this thesis, we explore both total syntheses and methodologies of several aromatic heterocyclic molecules. Extensions of the Kraus indole synthesis toward 2-substituted and 2,3-disubstituted indoles, as well as biologically attractive indolo[2,1-a]isoquinolines are described. Recent renewable efforts directed to commodity maleic acid and the first reported furan-based ionic liquids are described. Our total synthesis of mRNA aptamer ligand PDC-Gly, and its dye coupled forms, plus aminoglycoside dye coupled ligands used in molecular imaging, are described.
Date: May 7, 2013
Creator: Beasley, Jonathan
System: The UNT Digital Library
Templated synthesis of nickel nanoparticles: Toward heterostructured nanocomposites for efficient hydrogen storage (open access)

Templated synthesis of nickel nanoparticles: Toward heterostructured nanocomposites for efficient hydrogen storage

The world is currently facing an energy and environmental crisis for which new technologies are needed. Development of cost-competitive materials for catalysis and hydrogen storage on-board motor vehicles is crucial to lead subsequent generations into a more sustainable and energy independent future. This thesis presents work toward the scalable synthesis of bimetallic heterostructures that can enable hydrogen to compete with carbonaceous fuels by meeting the necessary gravimetric and volumetric energy densities and by enhancing hydrogen sorption/desorption kinetics near ambient temperatures and pressures. Utilizing the well-known phenomenon of hydrogen spillover, these bimetallic heterostructures could work by lowering the activation energy for hydrogenation and dehydrogenation of metals. Herein, we report a novel method for the scalable synthesis of silica templated zero-valent nickel particles (Ni⊂SiO{sub 2}) that hold promise for the synthesis of nickel nanorods for use in bimetallic heterostructures for hydrogen storage. Our synthesis proceeds by chemical reduction of a nickel-hydrazine complex with sodium borohydride followed by calcination under hydrogen gas to yield silica encapsulated nickel particles. Transmission electron microscopy and powder X-ray diffraction were used to characterize the general morphology of the resultant nanocapsules as well as the crystalline phases of the incorporated Ni{sup 0} nanocrystals. The structures display strong magnetic …
Date: May 7, 2013
Creator: Nelson, Nicholas Cole
System: The UNT Digital Library
Synthesis of main group, rare-earth, and d{sup 0} metal complexes containing beta-hydrogen (open access)

Synthesis of main group, rare-earth, and d{sup 0} metal complexes containing beta-hydrogen

A series of organometallic compounds containing the tris(dimethylsilyl)methyl ligand are described. The potassium carbanions KC(SiHMe{sub 2}){sub 3} and KC(SiHMe{sub 2}){sub 3}TMEDA are synthesized by deprotonation of the hydrocarbon HC(SiHMe{sub 2}){sub 3} with potassium benzyl. KC(SiHMe{sub 2}){sub 3}TMEDA crystallizes as a dimer with two types of three-center-two-electron KH- Si interactions. Homoleptic Ln(III) tris(silylalkyl) complexes containing β-SiH groups M{C(SiHMe{sub 2}){sub 3}}{sub 3} (Ln = Y, Lu, La) are synthesized from salt elimination of the corresponding lanthanide halide and 3 equiv. of KC(SiHMe{sub 2}){sub 3}. The related reactions with Sc yield bis(silylalkyl) ate-complexes containing either LiCl or KCl. The divalent calcium and ytterbium compounds M{C(SiHMe{sub 2}){sub 3}}{sub 2}L (M = Ca, Yb; L = THF{sub 2} or TMEDA) are prepared from MI{sub 2} and 2 equiv of KC(SiHMe{sub 2}){sub 3}. The compounds M{C(SiHMe{sub 2}){sub 3}}{sub 2}L (M = Ca, Yb; L = THF{sub 2} or TMEDA) and La{C(SiHMe{sub 2}){sub 3}}{sub 3} react with 1 equiv of B(C{sub 6}F{sub 5}){sub 3} to give 1,3- disilacyclobutane {Me2Si-C(SiHMe2)2}2 and MC(SiHMe2)3HB(C6F5)3L, and La{C(SiHMe{sub 2}){sub 3}}{sub 2}HB(C{sub 6}F{sub 5}){sub 3}, respectively. The corresponding reactions of Ln{C(SiHMe{sub 2}){sub 3}}{sub 3} (Ln = Y, Lu) give the β-SiH abstraction product [{(Me{sub 2}HSi){sub 3}C}{sub 2}LnC(SiHMe{sub 2}){sub 2}SiMe{sub 2}][HB(C{sub 6}F{sub 5}){sub 3}] …
Date: May 2, 2013
Creator: Yan, Ka King
System: The UNT Digital Library
Meausrement of the Neutron Radius of {sup 208}Pb Through Parity Violation in Electron Scattering (open access)

Meausrement of the Neutron Radius of {sup 208}Pb Through Parity Violation in Electron Scattering

In contrast to the nuclear charge densities, which have been accurately measured with electron scattering, the knowledge of neutron densities still lack precision. Previous model-dependent hadron experiments suggest the difference between the neutron radius, R{sub n}, of a heavy nucleus and the proton radius, R{sub p}, to be in the order of several percent. To accurately obtain the difference, R{sub n}-R{sub p}, which is essentially a neutron skin, the Jefferson Lab Lead ({sup 208}Pb) Radius Experiment (PREX) measured the parity-violating electroweak asymmetry in the elastic scattering of polarized electrons from {sup 208}Pb at an energy of 1.06 GeV and a scattering angle of 5{degrees}#14;. Since Z{sup 0} boson couples mainly to neutrons, this asymmetry provides a clean measurement of R{sub n} with respect to R{sub p}. PREX was conducted at the Jefferson lab experimental Hall A, from March to June 2010. The experiment collected a final data sample of 2x#2;10{sup 7} helicity-window quadruplets. The measured parity-violating electroweak asymmetry A{sub PV} = 0.656 {+-}#6; 0.060 (stat) {+-}#6; 0.014 (syst) ppm corresponds to a difference between the radii of the neutron and proton distributions, R{sub n}-R{sub p} = 0.33{sup +0.16}{sub -0.18} fm and provides the #12;first electroweak observation of the neutron skin …
Date: May 31, 2013
Creator: Saenboonruang, Kiadtisak
System: The UNT Digital Library
Evaluation of Law Enforcement and the Court System in Texas: Perspectives of Adult Protective Services Case Managers (open access)

Evaluation of Law Enforcement and the Court System in Texas: Perspectives of Adult Protective Services Case Managers

The purpose of this study was to examine perceptions of Texas Adult Protective Services (APS) case managers (CM) in regard to their relationships with the law enforcement community and area courts. The sample consisted of 138 Texas APS CMs. The survey measured respondents' perceived strengths and weaknesses of their relationships with both the law enforcement community and with area courts. Items also included respondents' interest in receiving additional training and their perceptions of level of job-readiness of newly hired APS CMs. Data were analyzed quantitatively using SAS. Findings of the survey revealed high ratings of perceived teamwork on the part of the CM are associated with high relationship ratings with both area courts and law enforcement. Findings also revealed that high ratings of perceived autonomy on the part of the CM are associated with lower relationship ratings with law enforcement personnel but not with area courts.
Date: May 2013
Creator: Weaver, Matthew S.
System: The UNT Digital Library
Early and Current Family Environment Among Inpatient Trauma Survivors: Associations with Multi-type Abuse and Sexual Orientation (open access)

Early and Current Family Environment Among Inpatient Trauma Survivors: Associations with Multi-type Abuse and Sexual Orientation

The present study is an exploratory analysis of associations among sexual orientation, childhood abuse, and characteristics of both early and current family environment in a sample of 80 inpatient trauma survivors. Participants were administered a background information questionnaire, Dissociative Disorders Interview Schedule, the Family Environment Scale and other instruments not analyzed in the current study. Multi-type abuse was significantly associated with low expressiveness and independence and high control in the early family, but no associations emerged with current family characteristics. Results suggest that the intergenerational transmission of family organization and moral-religious orientation occurred in the entire sample, and the transmission of family conflict patterns occurred only in the L/G/B group. Overall, participants perceived improvements in their current family environments compared to their early family environments. Findings yield support for the sexual minority stress model and mixed support for the intergenerational transmission of family characteristics.
Date: May 2013
Creator: Williams, Jennifer S.
System: The UNT Digital Library
The Girl Disappeared: the Prostitute of La Isla De Santa Flora (open access)

The Girl Disappeared: the Prostitute of La Isla De Santa Flora

The novella, The Girl Disappeared, focuses on the life of Emalia, a street kid from Mexico. She is taken from the streets of Veracruz and forced into a life of prostitution on the fictitious island of La Isla de Santa Flora. The primary conflict that drives the action of the story is her pending choice between escaping her life of slavery and saving another young woman who is on the verge of being forced into a life of prostitution as well. The novella, as a literary piece, dwells on the question of character agency and explores the multilayered nature of code switching. Language for these women becomes a tool in their struggle against their captives and a means of self-preservation, or sanctuary, as they use their growing bilingualism to foment a limited agency, to act in their own defense.
Date: May 2013
Creator: Winston, Michael
System: The UNT Digital Library
Analytical Model of Cold-formed Steel Framed Shear Wall with Steel Sheet and Wood-based Sheathing (open access)

Analytical Model of Cold-formed Steel Framed Shear Wall with Steel Sheet and Wood-based Sheathing

The cold-formed steel framed shear walls with steel sheets and wood-based sheathing are both code approved lateral force resisting system in light-framed construction. In the United States, the current design approach for cold-formed steel shear walls is capacity-based and developed from full-scale tests. The available design provisions provide nominal shear strength for only limited wall configurations. This research focused on the development of analytical models of cold-formed steel framed shear walls with steel sheet and wood-based sheathing to predict the nominal shear strength of the walls at their ultimate capacity level. Effective strip model was developed to predict the nominal shear strength of cold-formed steel framed steel sheet shear walls. The proposed design approach is based on a tension field action of the sheathing, shear capacity of sheathing-to-framing fastener connections, fastener spacing, wall aspect ratio, and material properties. A total of 142 full scale test data was used to verify the proposed design method and the supporting design equations. The proposed design approach shows consistent agreement with the test results and the AISI published nominal strength values. Simplified nominal strength model was developed to predict the nominal shear strength of cold-formed steel framed wood-based panel shear walls. The nominal shear …
Date: May 2013
Creator: Yanagi, Noritsugu
System: The UNT Digital Library
Cold-formed Steel Framed Shear Wall Sheathed with Corrugated Sheet Steel (open access)

Cold-formed Steel Framed Shear Wall Sheathed with Corrugated Sheet Steel

Incombustibility is one important advantage of the sheet steel sheathed shear wall over wood panel sheathed shear wall. Compared to shear wall sheathed with plywood and OSB panel, shear wall sheathed with flat sheet steel behaved lower shear strength. Although shear wall sheathed with corrugated sheet steel exhibited high nominal strength and high stiffness, the shear wall usually behaved lower ductility resulting from brittle failure at the connection between the sheathing to frames. This research is aimed at developing modifications on the corrugated sheathing to improve the ductility of the shear wall as well as derive practical response modification factor by establishing correct relationship between ductility factor ? and response modification factor R. Totally 21 monotonic and cyclic full-scale shear wall tests were conducted during the winter break in 2012 by the author in NUCONSTEEL Materials Testing Laboratory in the University of North Texas. The research investigated nineteen 8 ft. × 4 ft. shear walls with 68 mil frames and 27 mil corrugation sheet steel in 11 configurations and two more shear walls sheathed with 6/17-in.OSB and 15/32-in. plywood respectively for comparison. The shear walls, which were in some special cutting arrangement patterns, performed better under lateral load conditions according …
Date: May 2013
Creator: Yu, Guowang
System: The UNT Digital Library
Geoarchaeological Analysis of Two New Test Pits at the Dmanisi Site, Republic of Georgia (open access)

Geoarchaeological Analysis of Two New Test Pits at the Dmanisi Site, Republic of Georgia

This thesis presents the results of geoarchaeological investigations conducted at two new test pits, M11 and M12, at the paleoanthropological site of Dmanisi during the 2012 field season. This research is important for understanding the site formation processes occurring along the north-south axis of the Dmanisi site and how that affects the chronostratigraphic sequence and interpretation of archaeological materials here. With these excavations we can build a stronger interpretation for how broader areas of this site formed and changed both geologically and archaeologically. The geologic results of this study indicate that changes in sediment deposition and development episodes can affect interpretations of how long these sediments accumulated, how likely bones are to preserve, as well as how secondary gravel deposition can influence several archaeological interpretations. The archaeological results suggest that there could have been changes in occupation intensity between the stratum A and B phases although different rates of sediment deposition and surface stability could affect such artifact accumulations. In addition, during the stratum B phase there appears to be little change in artifact procurement behaviors and reduction characteristics by these hominins. The overall results of this research indicate that geologic factors should be addressed and cautions should be taken …
Date: May 2013
Creator: Zack, Winston S.
System: The UNT Digital Library
Layout-accurate Ultra-fast System-level Design Exploration Through Verilog-ams (open access)

Layout-accurate Ultra-fast System-level Design Exploration Through Verilog-ams

This research addresses problems in designing analog and mixed-signal (AMS) systems by bridging the gap between system-level and circuit-level simulation by making simulations fast like system-level and accurate like circuit-level. The tools proposed include metamodel integrated Verilog-AMS based design exploration flows. The research involves design centering, metamodel generation flows for creating efficient behavioral models, and Verilog-AMS integration techniques for model realization. The core of the proposed solution is transistor-level and layout-level metamodeling and their incorporation in Verilog-AMS. Metamodeling is used to construct efficient and layout-accurate surrogate models for AMS system building blocks. Verilog-AMS, an AMS hardware description language, is employed to build surrogate model implementations that can be simulated with industrial standard simulators. The case-study circuits and systems include an operational amplifier (OP-AMP), a voltage-controlled oscillator (VCO), a charge-pump phase-locked loop (PLL), and a continuous-time delta-sigma modulator (DSM). The minimum and maximum error rates of the proposed OP-AMP model are 0.11 % and 2.86 %, respectively. The error rates for the PLL lock time and power estimation are 0.7 % and 3.0 %, respectively. The OP-AMP optimization using the proposed approach is ~17000× faster than the transistor-level model based approach. The optimization achieves a ~4× power reduction for the OP-AMP …
Date: May 2013
Creator: Zheng, Geng
System: The UNT Digital Library
The Strategic and Operational Debate Over Operation Anvil: the Allied Invasion of Southern France in August, 1944 (open access)

The Strategic and Operational Debate Over Operation Anvil: the Allied Invasion of Southern France in August, 1944

In August, 1944, the Allies embarked on one of the "two supreme operations of 1944," Operation Anvil/Dragoon. It is an operation that almost did not happen. Envisioned as a direct supporting operation of Overlord, Anvil soon ran into troubles. Other operations taking away resources away from Anvil in addition to opposition from the highest levels of Allied command threatened Anvil. This thesis chronicles the evolution of this debate, as well as shed light on one of the most overlooked and successful operations the Allies embarked on in World War II.
Date: May 2013
Creator: Zinsou, Cameron
System: The UNT Digital Library
Derivation of the Thematic Material and Intervallic Gestures From the Main Theme in Fantasia Carioca By Sérgio Assad (open access)

Derivation of the Thematic Material and Intervallic Gestures From the Main Theme in Fantasia Carioca By Sérgio Assad

The quantity of classical guitar literature reached a new peak late in the twentieth century with many famous guitarists publishing their own works for solo classical guitar. This increase in the published guitar literature resulted in a decline of the relative analytical discussions of contemporary guitar works. Sérgio Assad is a perfect example of an active guitarist/composer whose works are frequently performed in guitar recitals and yet very little discussion has been provided attempting to gain a deeper understanding of his compositional language. The purpose of this study is to two-fold: first, to show that Fantasia Carioca (1994) is a very carefully organized work and includes an intricate network of thematic material developed through a spectrum of intervallic gestures, of which all derive from the main theme of the piece; second, to provide a deeper insight into the compositional language of Sérgio Assad through a demonstration of different compositional procedures to which the composer resorts. This one-movement piece reveals a high level of organization present in Sérgio Assad's style. The entire thematic material is carefully derived from the main theme. Each thematic unit shows a set of predetermined characteristics that allow these units to react to particular textures and situations. …
Date: May 2013
Creator: Abdihodži?, Armin
System: The UNT Digital Library
Pasados Fragmentados:la Representación Teatral Del Robo De Niños En Las Dictaduras Española Y Argentina En Obras De Laila Ripoll Y Patricia Suárez (open access)

Pasados Fragmentados:la Representación Teatral Del Robo De Niños En Las Dictaduras Española Y Argentina En Obras De Laila Ripoll Y Patricia Suárez

This study examines the theatrical representation of the stealing of children during the last dictatorships in Spain and in Argentina in Laila Ripoll's Los niños perdidos and Patricia Suárez's Astianacte: una máscara del amor under the lenses of the concepts of trauma, myth and memory. Following the theories suggested by Freud, Adorno, Whitehead, Reyes Mate and others, the first chapter discusses the representation of the psychological traumas left by the dictatorial practices left not only on the minds of individuals but also on both nations as whole entities. While Ripoll invites her audience to reflect upon the consequences of the Spanish Civil War and franquism, Patricia Suárez urges her spectators to doubt about their own identity if they were born during the last dictatorship in Argentina. In chapter two, the concepts advanced by Barthes, Reig Tapia and Moreno-Nuño help explore the ways in which the playwrights condemn the legitimizing myths that gave birth to these dictatorial regimes. Both authors subvert these fictional stories, mainly by the use of sarcasm and humor. By means of the concepts of memory supported by Benjamin, Todorov, Nora and Juliá, the third chapter examines the need to let the traditionally silenced voices tell their version …
Date: May 2013
Creator: Reyt, María Carolina
System: The UNT Digital Library
Finding Meaning in Context Using Graph Algorithms in Mono- and Cross-lingual Settings (open access)

Finding Meaning in Context Using Graph Algorithms in Mono- and Cross-lingual Settings

Making computers automatically find the appropriate meaning of words in context is an interesting problem that has proven to be one of the most challenging tasks in natural language processing (NLP). Widespread potential applications of a possible solution to the problem could be envisaged in several NLP tasks such as text simplification, language learning, machine translation, query expansion, information retrieval and text summarization. Ambiguity of words has always been a challenge in these applications, and the traditional endeavor to solve the problem of this ambiguity, namely doing word sense disambiguation using resources like WordNet, has been fraught with debate about the feasibility of the granularity that exists in WordNet senses. The recent trend has therefore been to move away from enforcing any given lexical resource upon automated systems from which to pick potential candidate senses,and to instead encourage them to pick and choose their own resources. Given a sentence with a target ambiguous word, an alternative solution consists of picking potential candidate substitutes for the target, filtering the list of the candidates to a much shorter list using various heuristics, and trying to match these system predictions against a human generated gold standard, with a view to ensuring that the …
Date: May 2013
Creator: Sinha, Ravi Som
System: The UNT Digital Library
Bioconcentration and Morphological Effects of Triclosan on Three Species of Wetland Plants (open access)

Bioconcentration and Morphological Effects of Triclosan on Three Species of Wetland Plants

Triclosan (TCS) is an antimicrobial compound found in several types of common household products. After being washed down the drain, TCS will then end up in the local watershed. Although numerous studies have been conducted to evaluate the fate and effects of TCS in aquatic environments, there have been no studies evaluating the role arbuscular mycorrhizal fungi (AM) play in a plants response to TCS exposure. Three species of wetland plants native North Texas were inoculated with AM spores and exposed to 0, 0.4 g/L and 4.0 g/L TCS concentrations. Root morphology of E. prostrata and S. herbacea showed AM and exposure responses. S. herbacea produced the greatest amounts biomass and TCS bioaccumulation, in all but one treatment. It also displayed opposing results to E. prostrata in measures of root length, root surface area, relative root mass, relative shoot mass and shoot:root ratio. TCS root tissue concentrations increased with increased exposures for both E. prostrata and S. herbacea. Even though E. prostrata had the lowest levels in each measure of biomass production, it had the highest amount of root TCS bioaccumulation in the AM inoculated 4.0 g/L treatment. H. laevis was between the other two species in terms of biomass …
Date: May 2013
Creator: Smith, Caleb M.
System: The UNT Digital Library
Modern Api Design and Physical Computing Techniques in Just Intonation Performance Practice (open access)

Modern Api Design and Physical Computing Techniques in Just Intonation Performance Practice

approached previously by both Harry Partch and Ben Johnston, and proposes the decoupling of interface and sound production as a way forward. The design and implementation of a software instrument and a hardware prototype are described, both using a simple API for variable tuning instruments. The hardware prototype uses physical computing techniques to control the tuning of a string with a servo motor, while the software instrument exists entirely in a web browser. Finally, potential algorithms for clients of the API are presented, and the effectiveness of the hardware prototype is evaluated by measuring its pitch accuracy.
Date: May 2013
Creator: Sonnabaum, Mark
System: The UNT Digital Library
The Beliefs and Expectations of Effective Secondary Choral Teachers in Culturally Diverse Schools (open access)

The Beliefs and Expectations of Effective Secondary Choral Teachers in Culturally Diverse Schools

Through the years, educational theorists and researchers have been interested in a possible relationship between teachers' effectiveness and their beliefs and expectations. Three concepts underpinned this work: teacher effectiveness, cultural diversity, and teachers' beliefs and expectations. The premise of the study was that the beliefs and expectations of effective secondary choral teachers are related to the social-cultural contexts in which they teach. The study implemented critical discourse analysis as the theoretical framework and the in-depth phenomenological long interview for data collection. Three secondary choral teachers were selected to participate in the study based on the researcher's criteria. The study revealed how each teacher conceptualized student cultural diversity during the teaching experience. Teacher beliefs about effective teaching in culturally diverse settings were described as developing over time in phases along a continuum. The study also confirmed that teachers' beliefs about students can be changed through experiences and reflection. The study revealed effective teachers focused on three different types of expectations in the teaching and learning context and affirmed diverse cultural identities and backgrounds. Recommendations included the development of stronger mentorship programs to increase effective teaching strategies for the secondary choral classroom. The findings of this study support my previous work, which …
Date: May 2013
Creator: Spradley, Mackie V.
System: The UNT Digital Library
Federal Funds Target Rate Surprise and Equity Duration (open access)

Federal Funds Target Rate Surprise and Equity Duration

In this paper I use an equity duration framework to develop and empirically test the hypothesis that returns on growth stock portfolios react more strongly to Federal Funds target rate change announcements, as compared to value stock portfolios. When I decompose the Federal Funds rate change, I find that portfolio returns are only sensitive to rate shocks, as opposed to the predictable component of rate change. Since growth stocks are expected to have higher duration than value stocks, I further explore the well documented polarity between value and growth stocks, by examining the interest rate sensitivities of portfolios that diverge along four fundamental-to-prices ratios: dividend yield, book-to-market value, earnings-to-price and cashflows-to-price. In each case, I find that price reactions are more pronounced for portfolios with high growth characteristics. I also document that portfolio returns react asymmetrically to positive and negative target rate surprises, and that this reaction is conditional on the state of business cycles - periods of economic expansions and recessions. To improve the robustness of my results, several statistical applications have been applied. First, I include Newey-west estimators to examine significant levels of regression estimates. Second, I check if there is any contemporaneous correlation across target rate shocks …
Date: May 2013
Creator: Tee, Kienpin
System: The UNT Digital Library
The Politics of Grading: a Comparative Study of High School English Teachers' Personal Beliefs, Self-reported Systems, and Actual Practices (open access)

The Politics of Grading: a Comparative Study of High School English Teachers' Personal Beliefs, Self-reported Systems, and Actual Practices

The purpose of this study was to attain and analyze data regarding high school English teachers' beliefs about grading practices and their self-reported grading practices, to identify and understand disparities that exist between teachers' beliefs and self-reported practices, to identify discrepancies between the same self-reported practices and evidence of the practices actually utilized, and to consider teachers' perceptions as to the causes for these discrepancies. Instrumentation for this study included two surveys with both Likert and Likert-like items and an interview/portfolio analysis of teachers' grading systems. A combined total of 204 high school English-language arts teachers representing thirty-eight states and eighty-five schools comprised the sample. Corresponding pairs of Likert-type items were analyzed using studies of the mode, median, mean rank, and the Mann-Whitney U Test to study a comparison of the medians, and comparisons of true Likert scale item results were completed using studies of the means and an independent samples t-test. Interview/portfolio analysis data were analyzed both descriptively and inferentially including the calculation of 95% confidence intervals for generalizability. All open-ended items were considered qualitatively through a process of identifying and categorizing trends in language and over-arching themes. Results indicate that the sample finds grading practices recommended by experts …
Date: May 2013
Creator: Thibodeaux, Lisa M.
System: The UNT Digital Library
Estimation of Aircraft Emissions for the Corpus Christi International Airport, Corpus Christi, Texas (open access)

Estimation of Aircraft Emissions for the Corpus Christi International Airport, Corpus Christi, Texas

Commercial aviation is a vital part of the United States economy. It generates over $1 trillion annually, which is more than 5% of the U.S. GDP, and produces approximately 10 million jobs. Every year there is an increase in commercial air traffic. This is attributed to expanding trade between states and other countries, which requires larger amounts of cargo aircraft in operation, and also catering to the growing number of middle and upper class passengers who travel for business and pleasure purposes. A rise in commercial aviation leads to the use of more aviation fuel on a monthly and annual basis. This in turn leads to escalated levels of combustion by-products from jet and turbofan engines into the atmosphere. The negative effects of these by-products range from producing poor air quality and consequent health hazards to contributing to global warming. This study is aimed at assessing the impacts of aircraft emissions on the local air quality in Corpus Christi using the Emissions and Dispersion Modeling System. Flight data for the study was obtained from the Department of Transportation's Research and Innovative Technology Administration. Analyses of the emissions were compared on monthly, annual, engine type and airline provider bases. Climatic, economic …
Date: May 2013
Creator: Thomas, Gregson Johann
System: The UNT Digital Library