A 'true' critical current density, j{sub c}, as opposite to commonly measured relaxed persistent (Bean) current, j{sub B}, was extracted from the Campbell penetration depth, {lambda}{sub c}(T,H) measured in single crystals of LiFeAs, and optimally electron-doped Ba(Fe{sub 0.954}Ni{sub 0.046}){sub 2}As{sub 2} (FeNi122). In LiFeAs, the effective pinning potential is nonparabolic, which follows from the magnetic field - dependent Labusch parameter {alpha}. At the equilibrium (upon field - cooling), {alpha}(H) is non-monotonic, but it is monotonic at a finite gradient of the vortex density. This behavior leads to a faster magnetic relaxation at the lower fields and provides a natural dynamic explanation for the fishtail (second peak) effect. We also find the evidence for strong pinning at the lower fields.The inferred field dependence of the pinning potential is consistent with the evolution from strong pinning, through collective pinning, and eventually to a disordered vortex lattice. The value of j{sub c}(2 K) {approx_equal} 1.22 x 10{sup 6} A/cm{sup 2} provide an upper estimate of the current carrying capability of LiFeAs. Overall, vortex behavior of almost isotropic, fully-gapped LiFeAs is very similar to highly anisotropic d-wave cuprate superconductors, the similarity that requires further studies in order to understand unconventional superconductivity in cuprates and …

High temperature alloys are essential to many industries that require a stable material to perform in harsh oxidative environments. Many of these alloys are suited for specific applications such as jet engine turbine blades where most other materials would either melt or oxidize and crumble (1). These alloys must have a high melting temperature, excellent oxidation resistance, good creep resistance, and decent fracture toughness to be successfully used in such environments. The discovery of Ni based superalloys in the 1940s revolutionized the high temperature alloy industry and there has been continued development of these alloys since their advent (2). These materials are capable of operating in oxidative environments in the presence of combustion gases, water vapor and at temperatures around 1050 C. Demands for increased f uel efficiency, however, has highlighted the need for materials that can be used under similar atmospheres and at temperatures in excess of 1200 C. The current Ni based superalloys are restricted to lower temperatures due to the presence of a number of low melting phases that result in softening of the alloys above 1000 C. Therefore, recent research has been aimed at exploring and developing newer alloy systems that can meet the escalating requirements. …

The development of fast magic angle spinning (MAS) opened up an opportunity for the indirect detection of insensitive low-{gamma} nuclei (e.g., {sup 13}C and {sup 15}N) via the sensitive high-{gamma} nuclei (e.g., {sup 1}H and {sup 19}F) in solid-state NMR, with advanced sensitivity and resolution. In this thesis, new methodology utilizing fast MAS is presented, including through-bond indirectly detected heteronuclear correlation (HETCOR) spectroscopy, which is assisted by multiple RF pulse sequences for {sup 1}H-{sup 1}H homonuclear decoupling. Also presented is a simple new strategy for optimization of {sup 1}H-{sup 1}H homonuclear decoupling. As applications, various classes of materials, such as catalytic nanoscale materials, biomolecules, and organic complexes, are studied by combining indirect detection and other one-dimensional (1D) and two-dimensional (2D) NMR techniques. Indirectly detected through-bond HETCOR spectroscopy utilizing refocused INEPT (INEPTR) mixing was developed under fast MAS (Chapter 2). The time performance of this approach in {sup 1}H detected 2D {sup 1}H{l_brace}{sup 13}C{r_brace} spectra was significantly improved, by a factor of almost 10, compared to the traditional {sup 13}C detected experiments, as demonstrated by measuring naturally abundant organic-inorganic mesoporous hybrid materials. The through-bond scheme was demonstrated as a new analytical tool, which provides complementary structural information in solid-state systems in …

The research program reported here is focused on critical issues that represent conspicuous gaps in current understanding of rapid solidification, limiting our ability to predict and control microstructural evolution (i.e. morphological dynamics and microsegregation) at high undercooling, where conditions depart significantly from local equilibrium. More specifically, through careful application of phase-field modeling, using appropriate thin-interface and anti-trapping corrections and addressing important details such as transient effects and a velocity-dependent (i.e. adaptive) numerics, the current analysis provides a reasonable simulation-based picture of non-equilibrium solute partitioning and the corresponding oscillatory dynamics associated with single-phase rapid solidification and show that this method is a suitable means for a self-consistent simulation of transient behavior and operating point selection under rapid growth conditions. Moving beyond the limitations of conventional theoretical/analytical treatments of non-equilibrium solute partitioning, these results serve to substantiate recent experimental findings and analytical treatments for single-phase rapid solidification. The departure from the equilibrium solid concentration at the solid-liquid interface was often observed during rapid solidification, and the energetic associated non-equilibrium solute partitioning has been treated in detail, providing possible ranges of interface concentrations for a given growth condition. Use of these treatments for analytical description of specific single-phase dendritic and cellular operating point …

In this dissertation we focus on the investigation of the pairing mechanism in the recently discovered high-temperature superconductor, iron pnictides. Due to the proximity to magnetic instability of the system, we considered short-range spin fluctuations as the major mediating source to induce superconductivity. Our calculation supports the magnetic fluctuations as a strong candidate that drives Cooper-pair formation in this material. We find the corresponding order parameter to be of the so-called ss-wave type and show its evolution with temperature as well as the capability of supporting high transition temperature up to several tens of Kelvin. On the other hand, our itinerant model calculation shows pronounced spin correlation at the observed antiferromagnetic ordering wave vector, indicating the underlying electronic structure in favor of antiferromagnetic state. Therefore, the electronic degrees of freedom could participate both in the magnetic and in the superconducting properties. Our work shows that the interplay between magnetism and superconductivity plays an important role to the understanding of the rich physics in this material. The magnetic-excitation spectrum carries important information on the nature of magnetism and the characteristics of superconductivity. We analyze the spin excitation spectrum in the normal and superconducting states of iron pnictides in the magnetic scenario. …

This thesis presents first measurements of moments of the hadronic n{sub X}{sup 2} distribution measured in inclusive semileptonic decays of B mesons to final states containing a charm quark, B {yields} X{sub c}{ell}{nu}. The variable n{sub X}{sup 2} is a combination of the invariant mass of the charmed meson m{sub X}, its energy in the B-meson rest-frame E{sub X;BRF}, and a constant {tilde {Lambda}} = 0.65 GeV, n{sub X}{sup 2} = m{sub X}{sup 2}c{sup 4}-2{tilde {Lambda}}E{sub X,BRF} + {tilde {Lambda}}{sup 2}. The moments <n{sub X}{sup k}> with k = 2,4,6 are measured as proposed by theory to constrain assumptions made in the theoretical description of inclusive observables in semileptonic B-meson decays. This description uses Heavy Quark Expansion (HQE), an effective QCD combined with an Operator Product Expansion. The measurement is based on a sample of 231.6 million e{sup +}e{sup -} {yields} {Upsilon}(4S) {yields} B{bar B} events recorded with the BABAR experiment at the PEP-II e{sup +}e{sup -}-storage rings at SLAC. We reconstruct the semileptonic decay by identifying a charged lepton in events tagged by a fully reconstructed hadronic decay of the second B meson. Correction procedures are derived from Monte Carlo simulations to ensure an unbiased measurement of the moments …

This dissertation explores lanthanide speciation in liquid solution systems related to separation schemes involving the acidic ligands: bis(2-ethylhexyl) phosphoric acid (HDEHP), lactate, and 8-hydroxyquinoline. Equilibrium speciation of neodymium (Nd3+), sodium (Na+), HDEHP, water, and lactate in the TALSPEAK liquid-liquid extraction system was explored under varied Nd3+ loading of HDEHP in the organic phase and through extraction from aqueous HCl and lactate media. System speciation was probed through vapor pressure osmometry, visible and Fourier Transform Infrared (FTIR) spectroscopy, 22Na and 13C labeled lactate radiotracer distribution measurements, Karl Fischer titrations, and equilibrium pH measurements. Distribution of Nd3+, Na+, lactate, and equilibrium pH were modeled using the SXLSQI software to obtain logKNd and logKNa extraction constants under selected conditions. Results showed that high Nd3+ loading of the HDEHP led to Nd3+ speciation that departs from the ion exchange mechanism and includes formation of highly aggregated, polynuclear [NdLactate(DEHP)2]x; (with x > 1). By substituting lanthanum (La3+) for Nd3+ in this system, NMR scoping experiments using 23Na, 31P nuclei and 13C labeled lactate were performed. Results indicated that this technique is sensitive to changes in system speciation, and that further experiments are warranted. In a homogeneous system representing the TALSPEAK aqueous phase, Lactate protonation behavior …

One of the central concerns of computational chemistry is that of efficiency (i.e. the development of methodologies which will yield increased accuracy of prediction without requiring additional computational resources – RAM, disk space, computing time). Though the equations of quantum mechanics are known, the solutions to these equations often require a great deal of computing power. This dissertation primarily concerns the theme of improved computational efficiency (i.e. the achievement of greater accuracy with reduced computational cost). Improvements in the efficiency of computational chemistry are explored first in terms of the correlation consistent composite approach (ccCA). The ccCA methodology was modified and this enhanced ccCA methodology was tested against the diverse G3/05 set of 454 energetic properties. As computational efficiency improves, molecules of increasing size may be studied and this dissertation explored the issues (differential correlation and size extensivity effects) associated with obtaining chemically accurate (within 1 kcal mol-1) enthalpies of formation for hydrocarbon molecules of escalating size. Two applied projects are also described; these projects concerned the theoretical prediction of a novel rare gas compound, FKrOH, and the mechanism of human glutathione synthetase’s (hGS) negative cooperativity. The final work examined the prospect for the parameterization of the modified embedded atom …

The efforts of my research have led to the successful construction of several instruments that have helped expand the field of microwave spectroscopy. The classic Balle-Flygare spectrometer has been modified to include two different sets of antenna to operate in the frequency ranges 6-18 GHz and 18-26 GHz, allowing it to function for a large range without having to break vacuum. This modified FTMW instrument houses two low noise amplifiers in the vacuum chamber to allow for the LNAs to be as close to the antenna as physically possible, improving sensitivity. A new innovative Balle-Flygare type spectrometer, the efficient low frequency FTMW, was conceived and built to operate at frequencies as low as 500 MHz through the use of highly curved mirrors. This is new for FTMW techniques that normally operate at 4 GHz or higher with only a few exceptions around 2 GHz. The chirped pulse FTMW spectrometer uses horn antennas to observe spectra that span 2 GHz versus the standard 1 MHz of a cavity technique. This instrument decreases the amount of time to obtain a large spectral region of relative correct intensity molecular transitions. A Nd:YAG laser ablation apparatus was attached to the classic Balle-Flygare and chirped …

This qualitative, inductive study analyzed online recruiting information posted at the websites of five major aerospace and defense corporations to recruit college juniors, seniors, and recent graduates. Recruitment of this group is critical to staff the personnel for the scientific, technical, and management needs of aerospace and defense industries. The study sought: (1) to determine the use of multiple recruitment factors inferred from the literature and recommended for successful recruitment of college graduates, (2) to determine use of online social media (Facebook, Twitter, LinkedIn) to recruit this population, and (3) to explore commonalities among these corporations regarding online recruiting information to determine if a model for online recruitment now exists. A matrix of recruitment factors was developed from a review of the literature on the personnel needs of this industry and on effective recruiting factors for this group. Content analysis involved filtering information at each website with the matrix. Conclusions of this study include: (1) the matrix of recruitment factors and the rating scale developed for the purposes of this study provide a tool for researching, documenting, and comparing recruitment information on the internet; (2) that while these corporations represent the latest applications in technology in their manufacturing processes and …

Businesses cluster to achieve agglomeration benefits. However, research in developing countries suggests that the economic environment limits small business’ propensity to benefit from agglomerations. The study examines the location, networking patterns, formal structures and owner characteristics of 1256 micro businesses from ten industries and thirteen sample areas in Toluca, Mexico. First, the thesis analyses whether clustering has a positive impact on the success rates of the surveyed enterprises, e.g. higher sales per employee. On an industry scale only Retail benefits from agglomerations economies. However, results of the neighborhood data show that specific areas benefit from urbanization economies. Overall, the study finds that businesses located within agglomerations, have higher levels of formalization, networking and professional training, hence constituting a more sophisticated base for economic development. Conclusions can be drawn for development policies and programs, arguing for a more differentiated approach of small business development depending on business location and cluster characteristics.

British composer Tarik Hamilton O’Regan (b. 1978, London) is earning a reputation as an important composer of today. The innovative works of O’Regan are entering the spectrum of professional, educational, and community performing organizations across the United States and Europe. Scattered Rhymes’ intricate melodic, harmonic, and rhythmic relationships with Messe de Notre Dame by Guillaume de Machaut (c.1300-1377) make an examination and comparison of the two works significant. Analyzing Scattered Rhymes by tracing its roots to Guillaume de Machaut’s Messe de Notre Dame, results in a renewed interest in this ancient work and brings prominence to Tarik O’Regan’s modern musical interpretation of ancient ideas. Understanding Scattered Rhymes as a work based on ideas from the fourteenth century in fusion with compositional concepts rooted in the modern era promotes Scattered Rhymes as one that is valuable in the current musical landscape.

The purpose of this study was to examine the development of work and family plans in young adults, and to clarify the long-term stability, prevalence, and consequences of anticipated work-family conflict. The study utilizes Super’s model of career development and social cognitive career theory, as well as research on current work-family interface, as a framework for understanding the period of anticipating and planning for multiple role integration that occurs between adolescence and adulthood. A sample of 48 male and 52 female college students assessed two years prior completed self-report questionnaires measuring work, marriage, and parenting experience; anticipated work-family conflict; and multiple-role planning. Results of this study suggest that students desire both a career and a family, and recognize potential challenges of a multiple-role lifestyle. Such recognition of anticipated work-family conflict varies by conflict domains and measurement methods, but remains stable over two years. Results also suggest that anticipated work-family conflict does not mediate the relationship between experience and planning; instead, marriage experience predicts planning directly. Implications for the findings are discussed as are suggestions for directions of new research concerning anticipated work-family conflict and planning for multiple roles.

This analysis of secondary data collected from family members of nursing home residents in North Texas (n = 422) used a mixed methods approach to determine if there is a difference in perspectives on quality care among family members of Alzheimer’s/Dementia Special Care Unit (ADSCU) residents compared to those of non-ADSCU residents. Descriptive content analysis was used identify and condense responses to an open-ended question into four meaningful categories of qualities of care. An independent t-test was employed to determine if there was a difference between family members of ADSCU residents and family members of non-ADSCU residents regarding their rating of their loved-ones’ nursing home on the important qualities of care they identified from the open-ended question. Closed-ended questions were organized into indices of these qualities of care, and ordinary least square regression was employed to determine if there were significant differences between perceptions of family members of ADSCU residents and those of non-ADSCU residents regarding care their loved-ones are receiving on these qualities of care, controlling for frequency of visit.

This study analyzes how the Art-Union, a British journal interested only in the fine arts, approached photography between 1839 and 1854. It is informed by Karl Marx’s materialism-informed commodity fetishism, Gerry Beegan’s conception of knowingness, Benedict Anderson’s imagined community, and an art critical discourse that was defined by Roger de Piles and Joshua Reynolds. The individual chapters are each sites in which to examine these multiple theoretical approaches to the journal’s and photography’s association in separate, yet sometimes overlapping, periods. One particular focus of this study concerns the method through which the journal viewed photography—as an artistic or scientific enterprise. A second important focus of this study is the commodification of both the journal and photography in Britain. Also, it determines how the journal’s critical engagement with photography fits into the structure and development of a nineteenth-century British social collectivity focused on art and the photographic enterprise.

Functional analysis procedures were used to assess and treat multiple topographies of self-injurious behavior exhibited by an individual. An experimental functional analysis indicated that one topography, hand biting, appeared to be maintained by social positive reinforcement in the form of delivery of tangible items. The analysis also provided evidence that a second form of self-injury, skin picking, was automatically reinforced. To treat positively reinforced hand biting, access to a preferred tangible was arranged contingent on the omission of biting for a prespecified time interval. Hand biting was nearly eliminated, and low rates were maintained as the schedule of reinforcement was thinned to 10 min. Competing stimulus assessments identified that magazines effectively suppressed all occurrences of skin picking; therefore, noncontingent access to magazines was implemented. Using a combination of multielement and multiple baseline designs, we were able to demonstrate that the two topographies of self-injury were maintained by independent reinforcement contingencies and that interventions corresponding to each topography and function effectively treated both behaviors.

This thesis is a reception study that examines potential reasons why the adolescent to college aged demographic of youth culture is embracing communicative and informational mobility. The project attests that the move to mobility is motivated by two major factors, the attraction of being an early adopter of technology and the way social behaviors are made attractive in mobile marketing. Chapter 1 explores the importance of these social behaviors, as they are very much intertwined and contribute to how youth acclimate into society. Chapter 2 demonstrates that creating social distinction and cultural capital is linked to being an early adopter of technology. The remaining portion of the document examines recent mobile advertisements and why youth would be attracted to the aesthetic and thematic elements contained in the advertisements. Chapter 3 examines how Blackberry utilizes the behavior of creating and expressing identity in their advertisements. Chapter 4 focuses on how Apple has worked to create a community centered around their brand. Finally, Chapter 5 looks at how Google/Android has highlighted the acquisition, sharing, and utilization of content through the phenomenon of applications. With this project, I hope to illustrate the rationale why youth would be attracted to communicative and informational mobility.

To do justice to Shakespeare’s comprehensive moral and political thought this paper seeks to discover what we can learn from the political philosophy of his largely neglected comedy, Taming of the Shrew. Not only does this endeavor provide a valuable forgotten link within the critical analyses of the theorists, but it also corrects the various misinterpretations of the play among contemporary critics. I argue that the play surveys various key themes that are rooted in classical political philosophy – such as education, the problems of anger, and the dynamic between nature and convention – and takes into consideration how they apply to modern man. Shakespeare borrows Plato’s idea that eroticism is central to education and explicitly references Ovid’s love books to reexamine our conceptions about one’s formation of character, the proper standards for judging the ideal mate, and the effects of these issues on the stability of the community. I also submit an innovative explanation of the relation between the induction and the main plot. Taken together they exhibit a critique of the role of the poet and his art in modern civil society.

In my study, I examine if and how Sandra Oh’s portrayal of Dr. Cristina Yang in Grey’s Anatomy, a primetime network drama, reifies or resists U.S. mediated stereotypes of Asian American females. I situate my intercultural study in an interpretive paradigm because I am want to explore how the evolving characteristics of existing the Asian American female mediated stereotype as they influence Asian American female identity. Additionally, I trace the historical development of Asian and Asian American stereotypes yellow peril to the model minority; and from Dragon Lady, Lotus Blossom, Geisha, and Suzie Wong. From my textual analysis, I suggest that when portrayals simultaneously reify and resist characteristics of existing Asian American stereotypes, they may help to breakdown perceived binaries of existing Asian and Asian American stereotypes.

The argument illustrated in the thesis outlines Zbigniew Brzezinski’s ability to manipulate himself and his agenda to top priority as the national security advisor to President Carter. It further argues that Brzezinski deserves more blame for the failure of American foreign policy towards Iran; not President Carter. The sources include primary sources such as Zbigniew Brzezinski and President Jimmy Carter’s memoirs as well as information from President Carter’s library in Atlanta, Georgia. Secondary sources include historians who focus on both presidential policy and President Carter and his staff. The thesis is organized as follows: the introduction of Brzezinski, then the focus turns to his time in the White House, Iran, then what he is doing today.

A bidirectional two-hop relay network with decode-and-forward strategy is implemented using GNU Radio (software) and several USRPs (hardware) on Ubuntu (operating system). The relay communication system is comprised of three nodes; Base Station A, Base Station B, and Relay Station (the intermediate node). During the first time slot, Base Station A and Base Station B will each transmit data, e.g., a JPEG file, to Relay Station using DBPSK modulation and FDMA. For the final time slot, Relay Station will perform a bitwise XOR of the data, and transmit the XORed data to Base Station A and Base Station B, where the received data is decoded by performing another XOR operation with the original data.

The major topics discussed are all relevant to interfacing brightly phosphorescent and non-luminescent coinage metal complexes of [Ag(I) and Au(I)] with biopolymers and thermoresponsive gels for making hybrid nanomaterials with an explanation on syntheses, characterization and their significance in biomedical fields. Experimental results and ongoing work on determining outreaching consequences of these hybrid nanomaterials for various biomedical applications like cancer therapy, bio-imaging and antibacterial abilities are described. In vitro and in vivo studies have been performed on majority of the discussed hybrid nanomaterials and determined that the cytotoxicity or antibacterial activity are comparatively superior when compared to analogues in literature. Consequential differences are noticed in photoluminescence enhancement from hybrid phosphorescent hydrogels, phosphorescent complex ability to physically crosslink, Au(I) sulfides tendency to form NIR (near-infrared) absorbing AuNPs compared to any similar work in literature. Syntheses of these hybrid nanomaterials has been thoroughly investigated and it is determined that either metallic nanoparticles syntheses or syntheses of phosphorescent hydrogels can be carried in single step without involving any hazardous reducing agents or crosslinkers or stabilizers that are commonly employed during multiple step syntheses protocols for syntheses of similar materials in literature. These astounding results that have been discovered within studies of hybrid nanomaterials …

Triclosan and triclocarban are antimicrobial compounds added to a variety of consumer products that are commonly detected in waste water effluent. The focus of this study was to determine whether the bioconcentration of these compounds in wetland plants and sediments exhibited species specific and site specific differences by collecting field samples from a constructed wetland in Denton, Texas. The study showed that species-specific differences in bioconcentration exist for triclosan and triclocarban. Site-specific differences in bioconcentration were observed for triclosan and triclocarban in roots tissues and sediments. These results suggest that species selection is important for optimizing the removal of triclosan and triclocarban in constructed wetlands and raises concerns about the long term exposure of wetland ecosystems to these compounds.

Bipolar disorder is a serious mental disorder, affecting anywhere from 2 to 4 percent of Americans. Though research has indicated that this disorder can be devastating for patients, less is known about how the disorder impacts family members. There is no research that has considered impacts on family members adjusting to college. The purpose of the current study was to determine the extent to which having a family member with bipolar disorder impacts adjustment to college, as well as factors that might account for worse functioning. Two groups were recruited: students with a bipolar family member (n = 25) and students with no family history of the disorder (n = 50). Participants were interviewed regarding their own histories of a mood disorder, as well as mood disorder histories in their immediate families. They then completed surveys assessing adjustment to college, functioning, caregiving burden, parental relationship, and attachment style. Students with a family history of bipolar disorder had significantly lower social adjustment scores, lower personal-emotional adjustment scores, and lower financial functioning scores than students without this history. Lower scores were found even after controlling for psychopathology. Avoidant attachment behaviors, anxious attachment behaviors, and aspects of the paternal relationship were identified as …