The ability to finely tune the size and shape of inorganic semiconducting nanocrystals is an area of great interest, as the more control one has, the more applications will be possible for their use. The first two basic shapes develped in nanocrystals were the sphere and the anistropic nanorod. the II_VI materials being used such as Cadmium Selenide (CdSe) and Cadmium Telluride (CdTe), exhibit polytypism, which allows them to form in either the hexagonally packed wurtzite or cubically packed zinc blende crystalline phase. The nanorods are wurtzite with the length of the rod growing along the c-axis. As this grows, stacking faults may form, which are layers of zinc blende in the otherwise wurtzite crystal. Using this polytypism, though, the first generation of branched crystals were developed in the form of the CdTe tetrapod. This is a nanocrystal that nucleates in the zincblend form, creating a tetrahedral core, on which four wurtzite arms are grown. This structure opened up the possibility of even more complex shapes and applications. This disseration investigates the advancement of branching control and further understanding the materials polytypism in the form of the stacking faults in nanorods.

Catalytic reactions of cyclohexene, benzene, n-hexane, 2-methylpentane, 3-methylpentane, and 1-hexene on platinum catalysts were monitored in situ via sum frequency generation (SFG) vibrational spectroscopy and gas chromatography (GC). SFG is a surface specific vibrational spectroscopic tool capable of monitoring submonolayer coverages under reaction conditions without gas-phase interference. SFG was used to identify the surface intermediates present during catalytic processes on Pt(111) and Pt(100) single-crystals and on cubic and cuboctahedra Pt nanoparticles in the Torr pressure regime and at high temperatures (300K-450K). At low pressures (<10{sup -6} Torr), cyclohexene hydrogenated and dehydrogenates to form cyclohexyl (C{sub 6}H{sub 11}) and {pi}-allyl C{sub 6}H{sub 9}, respectively, on Pt(100). Increasing pressures to 1.5 Torr form cyclohexyl, {pi}-allyl C{sub 6}H{sub 9}, and 1,4-cyclohexadiene, illustrating the necessity to investigate catalytic reactions at high-pressures. Simultaneously, GC was used to acquire turnover rates that were correlated to reactive intermediates observed spectroscopically. Benzene hydrogenation on Pt(111) and Pt(100) illustrated structure sensitivity via both vibrational spectroscopy and kinetics. Both cyclohexane and cyclohexene were produced on Pt(111), while only cyclohexane was formed on Pt(100). Additionally, {pi}-allyl c-C{sub 6}H{sub 9} was found only on Pt(100), indicating that cyclohexene rapidly dehydrogenates on the (100) surface. The structure insensitive production of cyclohexane was found …

Sum frequency generation (SFG) vibrational spectroscopy has been used to study the interfacial structure of several polypeptides and amino acids adsorbed to hydrophobic and hydrophilic surfaces under a variety of experimental conditions. Peptide sequence, peptide chain length, peptide hydrophobicity, peptide side-chain type, surface hydrophobicity, and solution ionic strength all affect an adsorbed peptide's interfacial structure. Herein, it is demonstrated that with the choice of simple, model peptides and amino acids, surface specific SFG vibrational spectroscopy can be a powerful tool to elucidate the interfacial structure of these adsorbates. Herein, four experiments are described. In one, a series of isosequential amphiphilic peptides are synthesized and studied when adsorbed to both hydrophobic and hydrophilic surfaces. On hydrophobic surfaces of deuterated polystyrene, it was determined that the hydrophobic part of the peptide is ordered at the solid-liquid interface, while the hydrophilic part of the peptide appears to have a random orientation at this interface. On a hydrophilic surface of silica, it was determined that an ordered peptide was only observed if a peptide had stable secondary structure in solution. In another experiment, the interfacial structure of a model amphiphilic peptide was studied as a function of the ionic strength of the solution, a …

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The ability of Solid Oxide Fuel Cells (SOFC) to directly and efficiently convert the chemical energy in hydrocarbon fuels to electricity places the technology in a unique and exciting position to play a significant role in the clean energy revolution. In order to make SOFC technology cost competitive with existing technologies, the operating temperatures have been decreased to the range where costly ceramic components may be substituted with inexpensive metal components within the cell and stack design. However, a number of issues have arisen due to this decrease in temperature: decreased electrolyte ionic conductivity, cathode reaction rate limitations, and a decrease in anode contaminant tolerance. While the decrease in electrolyte ionic conductivities has been countered by decreasing the electrolyte thickness, the electrode limitations have remained a more difficult problem. Nanostructuring SOFC electrodes addresses the major electrode issues. The infiltration method used in this dissertation to produce nanostructure SOFC electrodes creates a connected network of nanoparticles; since the method allows for the incorporation of the nanoparticles after electrode backbone formation, previously incompatible advanced electrocatalysts can be infiltrated providing electronic conductivity and electrocatalysis within well-formed electrolyte backbones. Furthermore, the method is used to significantly enhance the conventional electrode design by adding secondary …

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This dissertation documents the development of a broadband electron spectrometer (ESM) for GeV class Laser Wakefield Accelerators (LWFA), the production of high quality GeV electron beams (e-beams) for the first time in a LWFA by using a capillary discharge guide (CDG), and a statistical analysis of CDG-LWFAs. An ESM specialized for CDG-LWFAs with an unprecedented wide momentum acceptance, from 0.01 to 1.1 GeV in a single shot, has been developed. Simultaneous measurement of e-beam spectra and output laser properties as well as a large angular acceptance (> {+-} 10 mrad) were realized by employing a slitless scheme. A scintillating screen (LANEX Fast back, LANEX-FB)--camera system allowed faster than 1 Hz operation and evaluation of the spatial properties of e-beams. The design provided sufficient resolution for the whole range of the ESM (below 5% for beams with 2 mrad divergence). The calibration between light yield from LANEX-FB and total charge, and a study on the electron energy dependence (0.071 to 1.23 GeV) of LANEX-FB were performed at the Advanced light source (ALS), Lawrence Berkeley National Laboratory (LBNL). Using this calibration data, the developed ESM provided a charge measurement as well. The production of high quality electron beams up to 1 GeV …

In 1939, composer Julia Smith's first opera Cynthia Parker dramatized the story of a Texas legend. Smith manipulated music, text, and visual images to make the opera accessible for the audience in accordance with compositional and institutional practices in American opera of the 1930s. Transparent musical themes and common Native Americans stereotypes are used to define characters. Folk music is presented as diegetic, creating a sense of authenticity that places the audience into the opera's Western setting. The opera is codified for the audience using popular idioms, resulting in initial but not lasting success.

AGenesis is a novel of "postmortal fiction" set entirely in an afterlife. Nessie, a recently dead woman, accidentally kills an already-dead man, and in the confusion that follows, sets out to discover how he could have died and what after-afterlife he might have gone to. During her travels, she is raped and then help captive by a city of tormented souls; she descends into madness until rescued by children, and she and her newborn but "undead" daughter set out again, this time to find the end of the afterlife. Nessie's daughter eventually seeks a way to enter a living world she's never known, while Nessie tries to end her suffering and find peace.

The plurality of worlds has had a long history in England, which has not gone unnoticed by scholars. Historians have tended to view this English pluralist tradition as similar to those found on the continent, and in doing so have failed to fully understand the religious significance that the plurality of worlds had on English thought and society. This religious significance is discovered through a thorough investigation of plurality as presented by English natural philosophers and theologians, and in so doing reveals much about England in the seventeenth century. As natural philosophers incorporated plurality within the larger framework of natural theology, it became a weapon of science and reason to be used against the unreasonable atheists of late seventeenth-century England.

In this thesis, I address the dichotomy between liberal arts education and terminal vocational training in the American community college. The need is for reform in the community college in relation to philosophical instruction in order to empower citizens, support justice and create more sustainable communities. My call for reform involves a multicultural integration of philosophy into terminal/vocational programs as well as evolving the traditional liberal arts course to exist in a multicultural setting. Special attention is focused on liberating the oppressed, social and economic justice and philosophy of education.

Motor vehicle theft is the costliest property crime in the United States equaling billions of dollars in losses each year. Despite law enforcement success in decreasing the rate of motor vehicle theft in recent years, the actual number of thefts has increased. It is vital for law enforcement agencies to know who is committing motor vehicle theft and where vehicles are being stolen. This study answers these questions by examining offender demographic characteristics and the location types most targeted for motor vehicle theft in Texas from 2001 to 2005. The state of Texas was chosen because Texas has continually been ranked second in the Federal Bureau of Investigation's Uniform Crime Report for the number of reported incidents of motor vehicle theft in the United States.

Macromolecular interactions are essential for virtually all cellular functions including signal transduction processes, metabolic processes, regulation of gene expression and immune responses. This dissertation focuses on the characterization of two important macromolecular interactions involved in the relationship between Equine Infectious Anemia Virus (EIAV) and its host cell in horse: (1) the interaction between the EIAV Rev protein and its binding site, the Rev-responsive element (RRE) and (2) interactions between equine MHC class I molecules and epitope peptides derived from EIAV proteins. EIAV, one of the most divergent members of the lentivirus family, has a single-stranded RNA genome and carries several regulatory and structural proteins within its viral particle. Rev is an essential EIAV regulatory encoded protein that interacts with the viral RRE, a specific binding site in the viral mRNA. Using a combination of experimental and computational methods, the interactions between EIAV Rev and RRE were characterized in detail. EIAV Rev was shown to have a bipartite RNA binding domain contain two arginine rich motifs (ARMs). The RRE secondary structure was determined and specific structural motifs that act as cis-regulatory elements for EIAV Rev-RRE interaction were identified. Interestingly, a structural motif located in the high affinity Rev binding site is …

This pilot study addresses the distribution of nonstandard syntactic and lexical features in Indian English (IE) across a homogeneous group of highly educated IE speakers. It is found that nonstandard syntactic features of article use, number agreement and assignment of verb argument structure do not display uniform intragroup distribution. Instead, a relationship is found between nonstandard syntactic features and the sociolinguistic variables of lower levels of exposure to and use of English found within the group. While nonstandard syntactic features show unequal distribution, nonstandard lexical features of semantic reassignment, and mass nouns treated as count nouns display a more uniform intragroup distribution.

This research studied the Anderson localization of electrons in two-channel wires with correlated disorder and in DNA molecules. It involved an analytical calculation part where the formula for the inverse localization length for electron states in a two-channel wire is derived. It also involved a computational part where the localization length is calculated for some DNA molecules. Electron localization in two-channel wires with correlated disorder was studied using a single-electron tight-binding model. Calculations were within second-order Born-approximation to second-order in disorder parameters. An analytical expression for localization length as a functional of correlations in potentials was found. Anderson localization in DNA molecules were studied in single-channel wire and two-channel models for electron transport in DNA. In both of the models, some DNA sequences exhibited delocalized electron states in their energy spectrum. Studies with two-channel wire model for DNA yielded important link between electron localization properties and genetic information.

Grandparent-headed families are diverse in nature and represent a rapidly growing family type. While challenges facing grandparent caregivers are well documented, less is known about the well-being of their grandchildren, with many early studies relying on small samples of convenience. This study used an existing large national database, the National Survey of America's Families (NSAF), to compare differences in well-being of both children and grandparent caregivers across the independent variables of family type, ethnicity, gender, and age. Findings suggested better mental health and less parental aggravation for caregivers in traditional two parent intact families as compared to grandparents co-parenting in a multi-generation home, skipped generation grandparents (raising their grandchild with no parent present) or single parents. Skipped generation grandparents in particular reported most caregiver aggravation. Child physical health was reported to be worse by skipped generation grandparent caregivers. Behavior problems were reported to be worse for children in grandparent headed households than those in traditional families, particularly for teenagers raised in skipped generation households by their grandmothers. Specific results, limitations and future directions for research on grandparent-headed households were discussed.

It is now widely accepted that the Standard Model assumption of massless neutrinos is wrong, due primarily to the observation of solar and atmospheric neutrino flavor oscillations by a small number of convincing experiments. The MINOS Far Detector, capable of observing both the outgoing lepton and associated showering products of a neutrino interaction, provides an excellent opportunity to independently search for an oscillation signature in atmospheric neutrinos. To this end, a MINOS data set from an 883 live day, 13.1 kt-yr exposure collected between July, 2003 and April, 2007 has been analyzed. 105 candidate charged current muon neutrino interactions were observed, with 120.5 {+-} 1.3 (statistical error only) expected in the absence of oscillation. A maximum likelihood analysis of the observed log(L/E) spectrum shows that the null oscillation hypothesis is excluded at over 96% confidence and that the best fit oscillation parameters are sin{sup 2} 2{theta}{sub 23} = 0.95{sub -0.32} and {Delta}m{sub 23}{sup 2} = 0.93{sub -0.44}{sup +3.94} x 10{sup -3} eV{sup 2}. This measurement of oscillation parameters is consistent with the best fit values from the Super-Kamiokande experiment at 68% confidence.

Current syndromic surveillance systems utilize centralized databases that are neither scalable in storage space nor in computing power. Such systems are limited in the amount of syndromic data that may be collected and analyzed for the early detection of infectious disease outbreaks. However, with the increased prevalence of international travel, public health monitoring must extend beyond the borders of municipalities or states which will require the ability to store vasts amount of data and significant computing power for analyzing the data. Intelligent mobile agents may be used to create a distributed surveillance system that will utilize the hard drives and computer processing unit (CPU) power of the hosts on the agent network where the syndromic information is located. This thesis proposes the design of a mobile agent-based syndromic surveillance system and an agent decision model for outbreak detection. Simulation results indicate that mobile agents are capable of detecting an outbreak that occurs at all hosts the agent is monitoring. Further study of agent decision models is required to account for localized epidemics and variable agent movement rates.

The sudden release of toxic contaminants that reach indoor spaces can be hazardousto building occupants. To respond effectively, the contaminant release must be quicklydetected and characterized to determine unobserved parameters, such as release locationand strength. Characterizing the release requires solving an inverse problem. Designinga robust real-time sensor system that solves the inverse problem is challenging becausethe fate and transport of contaminants is complex, sensor information is limited andimperfect, and real-time estimation is computationally constrained.This dissertation uses a system-level approach, based on a Bayes Monte Carloframework, to develop sensor-system design concepts and methods. I describe threeinvestigations that explore complex relationships among sensors, network architecture,interpretation algorithms, and system performance. The investigations use data obtainedfrom tracer gas experiments conducted in a real building. The influence of individual sensor characteristics on the sensor-system performance for binary-type contaminant sensors is analyzed. Performance tradeoffs among sensor accuracy, threshold level and response time are identified; these attributes could not be inferred without a system-level analysis. For example, more accurate but slower sensors are found to outperform less accurate but faster sensors. Secondly, I investigate how the sensor-system performance can be understood in terms of contaminant transport processes and the model representation that is used to solve the …

The Six épigraphes antiques represent a cross-section of Debussy's creative output that traces the composer's germ-seed from his original setting of the work in 1901 as incidental music to accompany the recitation of several poems, to the four-hand piano version of 1914, and its consequent reduction for solo piano. What can be gleaned by the methods of derivation from his original sketches to the final, mature works is an understanding of Debussy's use of musical metaphor and his connection to the poetry - the Chansons de Bilitis of Pierre Louÿs. Embedded literary procedures create a new musical expression of the work whereby text and music become integrated. Rather than serving as accompaniment to the poems, the Épigraphes function as the primary vessel for the conveyance of these ancient scenes. Several of Debussy's hallmark symmetrical and structural moulds, such as the whole-tone, chromatic, octatonic, and mirroring techniques reflect the omnipresent symmetry of Classical Greece. Various other artistic creations emanated from the Épigraphes, most significantly the orchestration of Ernest Ansermet in 1939. A look at the techniques used by Ansermet for the augmentation of the piano work serves to extrapolate the multifarious layers relevant in performance. In order to facilitate the four-hand …

No other government agency receives as much attention as the National Aeronautics and Space Administration (NASA). The high-profile agency frequently captures attention of the media in both positive and negative contexts. This thesis takes a case study approach using organizational learning and sensemaking theories to investigate crisis communication within NASA's 2003 Columbia tragedy. Eight participants, who in some capacity had worked for NASA during the Columbia tragedy in a communication centered position, were interviewed. Using a grounded theory framework, nine themes emerged pertaining to organizational learning, leadership, structure, and organizational culture. The results of the study aid in understanding how high risk organization's (HROs) can learn from previous failures and details how organizational culture can hinder organizational change.

As the world becomes increasingly interdependent, mutual understanding becomes increasingly important. Therefore, it is essential that people strive for reductions in social distance on an international level. Study abroad is one of the ways to approach internationalization and promote understanding among different peoples and cultures. Prior research has been done on the degrees of social distance between people from different cultures; however, little research has been done regarding changes that cultural immersion produces among those who reside in different cultures. Studies about study abroad programs have focused on cultural sensitivity and adaptability, yet few have combined the study abroad experience with the perceptions of self and other cultural groups. This study presents a framework for understanding people through intercultural activities. It studied social distance and attitude changes brought about in social distance as an artifact of cultural immersion. The study took place both in China and in the United States. It focused on the social distance among American undergraduate students who participated in a China Study Abroad program sponsored by the University of North Texas. The study measured before and after social distance of a group of American students who studied abroad in China. The study abroad program itself was …

When a stock is added into the S&P 500 Index, it is automatically "cross-listed" in the index derivative markets (i.e., S&P 500 Index futures and Index options). I examined the effects of such cross-listing on the trading volume and return volatility of the underlying component stocks. Traditional finance theory asserts that futures and "cash" markets are connected by arbitrage mechanism that brings both markets to equilibrium. When arbitrage opportunities arise, arbitrageurs buy (sell) the index portfolio and take short (long) positions in the corresponding index derivative contracts until prices return to theoretical levels. Such mechanical arbitrage trading tends to create large order flows that could be difficult for the market to absorb, resulting in price changes. Utilizing a list of S&P 500 index composition changes occurring over the period September 1976 to December 2005, I investigated the market-adjusted volume turnover ratios and return variances of the stocks being added to and deleted from the S&P 500, surrounding the effective day of index membership changes. My primary finding is that, after the introduction of the S&P 500 index futures and options contracts, stocks added to the S&P 500 experience significant increase in both trading volume and return volatility. However, deleted stocks …

This study traced the evolution of experiential education in American history museums from 1787 to 2007. Because of a decline in attendance, museum educators need to identify best practices to draw and retain audiences. I used 16 museology and history journals, books, and archives of museums prominent for using the method. I also interviewed 15 museum educators who employ experiential learning, one master interpreter of the National Park Service, and an independent museum exhibit developer. Experiential education involves doing with hands touching physical materials. Four minor questions concerned antecedents of experiential learning, reasons to invest in the method, the influence of social context, and cultural pluralism. Next is a review of the theorists whose works support experiential learning: Dewey, Piaget, Vygotsky, Lewin, Bruner, Eisner, Hein, and David Kolb plus master parks interpreter Freeman Tilden. The 8 characteristics they support include prior experiences, physical action, interaction with the environment, use of the senses, emotion, social relationships, and personal meaning. Other sections are manifestation of experiential learning, transformation of history museums, and cultural pluralism in history museums. The research design is descriptive, and the procedure, document analysis and structured interview. Findings are divided by decades after the first 120 years. Social context, …