UNT Theses and Dissertations - 18,577 Matching Results

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The Acute Toxic Effects of the Synthetic Cannabinoid, JWH-018 on the Cardiovascular and Neuroendocrine System in Ictalurus punctatus (Channel Catfish)
Cannabinoid (CB) receptors have been found in most vertebrates that have been studied. The location of various CB receptors in the body and brain are known, but their physiological functions are not fully understood. The effects CBs have on the cardiovascular system have been of growing interest in recent years. Increasing reports from emergency departments and law enforcement agencies detail acute cardiovascular and psychological effects from synthetic CB intoxication, such as JWH-018. This major health concern is substantiated by governmental agencies like the CDC and NIDA. This pilot study investigates the acute toxic effects of the synthetic CB, JWH-018, on the cardiovascular and neuroendocrine systems in Ictalurus punctatus (channel catfish). Research in organisms besides the traditional mammal models can provide new insights into CB function and physiology. Ictalurus punctatus lend multiple benefits as a model organism that permits researchers to investigate in vivo effects of both cardiovascular and neuroendocrine systems without much influence from traditional sampling methods, and further more provide ample size and tissue to perform specific cardiovascular experiments. Multiple methods were used to assess cardiovascular function and sympathetic nervous system activation. Two different doses, low (500 µg/kg) and high 1,500 µg/kg, of JWH-018 were evaluated in the study. Delivery of JWH-018, via dorsal aorta cannulation, was administered to channel catfish in order to measure cardiovascular functions and sample blood. Plasma levels of the hypothalamus-pituitary-adrenal/interrenal (HPA/I) biomarkers; ACTH, cortisol, epinephrine, and norepinephrine, were measured using ELISAs. Myocardial and neural tissue was collected after the exposures for rt-PCR analysis on β2 adrenergic and glucocorticoid receptor density change. Acute exposure of JWH-018 in undisturbed channel catfish yielded several findings: (1) High dose of JWH-018 was responsible for cardio depressor effects in catfish with a tendency to produce tachycardia, (2) rt-PCR results showed a 2.7 fold increase of glucocorticoid receptor mRNA density ...
Additive Manufacturing of Metastable Beta Titanium Alloys
Additive manufacturing processes of many alloys are known to develop texture during the deposition process due to the rapid reheating and the directionality of the dissipation of heat. Titanium alloys and with respect to this study beta titanium alloys are especially susceptible to these effects. This work examines Ti-20wt%V and Ti-12wt%Mo deposited under normal additive manufacturing process parameters to examine the texture of these beta-stabilized alloys. Both microstructures contained columnar prior beta grains 1-2 mm in length beginning at the substrate with no visible equiaxed grains. This microstructure remained constant in the vanadium system throughout the build. The microstructure of the alloy containing molybdenum changed from a columnar to an equiaxed structure as the build height increased. Eighteen additional samples of the Ti-Mo system were created under different processing parameters to identify what role laser power and travel speed have on the microstructure. There appears to be a correlation in alpha lath size and power density. The two binary alloys were again deposited under the same conditions with the addition of 0.5wt% boron to investigate the effects an insoluble interstitial alloying element would have on the microstructure. The size of the prior beta grains in these two alloys were reduced with the addition of boron by approximately 50 (V) and 100 (Mo) times.
African American Soldiers in the Philippine War: An Examination of the Contributions of the Buffalo Soldiers during the Spanish American War and Its Aftermath, 1898-1902
During the Philippine War, 1899 – 1902, America attempted to quell an uprising from the Filipino people. Four regular army regiments of black soldiers, the Ninth and Tenth Cavalry, and the Twenty-Fourth and Twenty-Fifth Infantry served in this conflict. Alongside the regular army regiments, two volunteer regiments of black soldiers, the Forty-Eighth and Forty-Ninth, also served. During and after the war these regiments received little attention from the press, public, or even historians. These black regiments served in a variety of duties in the Philippines, primarily these regiments served on the islands of Luzon and Samar. The main role of these regiments focused on garrisoning sections of the Philippines and helping to end the insurrection. To carry out this mission, the regiments undertook a variety of duties including scouting, fighting insurgents and ladrones (bandits), creating local civil governments, and improving infrastructure. The regiments challenged racist notions in America in three ways. They undertook the same duties as white soldiers. They interacted with local "brown" Filipino populations without fraternizing, particularly with women, as whites assumed they would. And, they served effectively at the company and platoon level under black officers. Despite the important contributions of these soldiers, both socially and militarily, little research focuses on their experiences in the Philippines. This dissertation will discover and examine those experiences. To do this, each regiment is discussed individually and their experiences used to examine the role these men played in the Philippine War. Also addressed is the role ideas about race played in these experiences. This dissertation looks to answer whether or not notions on race played a major role in the activities of these regiments. This dissertation will be an important addition to the study of the Philippine War, the segregated U. S. Army, and African American history in the modern period.
"Among the Voices Voiceless": Setting the Words of Samuel Beckett
Among the Voices Voiceless is a composition for flute (doubling piccolo), clarinet (doubling bass clarinet), viola, cello, percussion, piano, and electronics, based on the poem "What would I do without this world faceless incurious" by Samuel Beckett. The piece is a setting for disembodied voice: the vocal part exists solely in the electronics. Having no physical body, the voice is obscured as the point of empathy for the audience. In addition, instrumental solos compete for focus during the work's twenty minute duration. In passages including a soloist, the soloist functions simultaneously as antagonist and avatar to the disembodied voice. Spoken word recordings and electronic manipulation of instrumental material provides further layers of ambiguity. The companion critical essay "Among the Voices Voiceless": Setting the Words of Samuel Beckett proposes the distillation of Beckett's style into the elements of prosaicness, repetition, fragmentation, ambiguity, and symmetry. Discussions of Beckett's works such as Waiting for Godot and Molloy demonstrate these elements in his practice. This framework informs the examination of two other musical settings of Beckett's poetry: Neither by Morton Feldman and Odyssey by Roger Reynolds. Finally, these elements are used to analyze and elucidate the compositional decisions made in Among the Voices Voiceless.
Application of UV-Vis Spectroscopy to the Monitoring, Characterization and Analysis of Chemical Equilibria of Copper Etching Baths
The continuously increasing demand for innovation in the miniaturization of microelectronics has driven the need for ever more precise fabrication strategies for device packaging, especially for printed circuit boards (PCBs). Subtractive copper etching is a fundamental step in the fabrication process, requiring very precise control of etch rate and etch factor. Changes in the etching chemical equilibrium have significant effects on etching behavior, and CuCl2 / HCl etching baths are typically monitored with several parameters including oxidation-reduction potential, conductivity, and specific gravity. However, the etch rate and etch factor can be difficult to control even under strict engineering controls of those monitoring parameters. The mechanism of acidic cupric chloride etching, regeneration and recovery is complex, and the current monitoring strategies can have difficulty controlling the interlocking chemical equilibria. A complimentary tool, thin-film UV-Vis spectroscopy, can be utilized to improve the current monitoring strategies, as UV-Vis is capable of identifying and predicting etching behavior that the current standard methodologies have difficulty predicting. Furthermore, as a chemically-sensitive probe, UV-Vis can investigate the complex changes to the chemical equilibrium and speciation of the etch bath, and can contribute overall to significant improvements in the control of the copper etching system in order to meet the demands of next-level design strategies.
Are Streams Protected? Outcomes of Environmental Regulation
Urban areas experience the loss of natural stream channels through conversion to artificial conveyances. This process tends to target headwater and other low order streams. The purpose of this study is to determine the patterns of stream loss in Denton, Texas, and explore the regulatory structure that manages these streams. Historic and current maps and stream data are used to map Denton's streams and categorize them according to their vertical connectivity as: 1) "intact", streams that are open to the atmosphere and connect to groundwater; 2) "concrete", channelized streams open to the atmosphere but cut off from groundwater; and 3) "buried", streams disconnected from the atmosphere and groundwater. A review of federal, state, and local regulatory codes and interviews with local government officials and other stakeholders elucidates stream management in Denton. Results from these analyses reveal high rates of stream loss in the urban center with low rates overall. The federal Clean Water Act and the local Environmentally Sensitive Areas code serve as the primary protective measures for natural streams. These regulations discourage stream impacts through expensive and complex permitting requirements. However the policies allow minor impacts which may cause cumulative effects. This study aims to inform future policy-making decisions and contribute to the knowledge of the environmental regulation of streams.
Assessment of Competencies among Doctoral Trainees in Psychology
The recent shift to a culture of competence has permeated several areas of professional psychology, including competency identification, competency-based education training, and competency assessment. A competency framework has also been applied to various programs and specialty areas within psychology, such as clinical, counseling, clinical health, school, cultural diversity, neuro-, gero-, child, and pediatric psychology. Despite the spread of competency focus throughout psychology, few standardized measures of competency assessment have been developed. To the authors' knowledge, only four published studies on measures of competency assessment in psychology currently exist. While these measures demonstrate significant steps in progressing the assessment of confidence, three of these measures were designed for use with individual programs, two of these international (i.e., UK and Taiwan). The current study applied the seminal Competency Benchmarks, via a recently adapted benchmarks form (i.e., Practicum Evaluation form; PEF), to practicum students at the University of North Texas. In addition to traditional supervisor ratings, the present study also involved self-, peer supervisor, and peer supervisee ratings to provide 360-degree evaluations. Item-response theory (IRT) was used to evaluate the psychometric properties of the PEF and inform potential revisions of this form. Supervisor ratings of competency were found to fit the Rasch model specified, lending support to use of the benchmarks framework as assessed by this form. Self- and peer-ratings were significantly correlated with supervisor ratings, indicating that there may be some utility to 360-degree evaluations. Finally, as predicted, foundational competencies were rated as significantly higher than functional competencies, and competencies improved significantly with training. Results of the current study provide clarity about the utility of the PEF and inform our understanding of practicum-level competencies.
Best Practices in Targeted Advertising for Fashion Entrepreneurs
A key to a business's success is reaching the target market. This ensures that consumers are exposed to the retailer's offerings and by turn, inspired to purchase. In turn, the business can reach its goal of a profitable organization. The purpose of this paper was to determine the most effective fashion advertising appeals for reaching target markets. To address these issues, this thesis consisted of two studies. The purpose of the first study was to determine the advice given to fashion entrepreneurs regarding effective target market practices. The purpose of the second study was to determine effective advertising strategies fashion entrepreneurs may employ for effectively reaching target markets. Data was collected to test the effectiveness of the advice from Study 1, degrees of brand awareness, attitudes towards advertising, willingness to follow trends, purchase intention, purchase behavior, and shopping involvement. The Theory of Reasoned Action was employed as the theoretical framework of the study. The framework was utilized to predict that attitudes towards targeted advertising and pressure to follow fashion trends would positively relate to intent to purchase which, in turn, would positively relate to purchase behavior. The results of this paper concluded the TRA model provided a proper framework to predict purchase behavior from targeted advertising employed by fashion entrepreneurs.
BLE Controller Module for Wireless Sensor Networks
Sensors have been an integral part of our life since a long time. Traditionally, the transmit information to a data collection center through a physical wire. However, with the introduction of Bluetooth Low Energy (BLE) communication protocol, more research is being done into the field of wireless sensor networks (WSN). BLE was introduced to target low power applications. The CC2650 Launchpad designed by Texas Instruments (TI) can lead to a bulky final product. The aim was to design hardware for the CC2650 micro-controller with the aim of making it more compact for use in WSNs. A top-down approach was used wherein the available product is studied to identify the redundant and reverse engineer it to design a new product. A 2 layer printed circuit board (PCB) was designed which resulted in a 64 percent decrease in size compared to the Launchpad. Also, experiments were performed to test the proof of concept.
A Case Study of Mathematics Teachers' Use of Short-Cycle Formative Assessment Strategies
A single case study was used to examine two middle grades mathematics teachers' use of short-cycle formative assessment strategies. Data was collected using multiple sources to provide a description of this single case. Participant change in knowledge of short-cycle formative assessment strategies was collected and analyzed through participant pre- and post-interviews and targeted instructional support was provided through professional development sessions designed to meet diverse needs of participants. Participant change in use of short-cycle formative assessment strategies was collected and analyzed through classroom observations using Assess Today observation protocol and targeted instructional support was provided through post-observation conferences with written feedback. Findings from the study verified that changes in teachers' use of short-cycle formative assessment strategies were positively influenced by the targeted instructional support provided to each participant during the study. The study further indicated that an assessment of teacher's present knowledge and use of short-cycle formative assessment strategies should be considered before providing targeted instructional support to maximize the learning potential for each teacher. Future research is needed regarding the importance of building student self-efficacy through teacher use of short-cycle formative assessment, as well as the importance of involving students in the formative assessment process.
A Classification of the Homogeneity of Countable Products of Subsets of Real Numbers
Spaces such as the closed interval [0, 1] do not have the property of being homogeneous, strongly locally homogeneous (SLH) or countable dense homogeneous (CDH), but the Hilbert cube has all three properties. We investigate subsets X of real numbers to determine when their countable product is homogeneous, SLH, or CDH. We give necessary and sufficient conditions for the product to be homogeneous. We also prove that the product is SLH if and only if X is zero-dimensional or an interval. And finally we show that for a Borel subset X of real numbers the product is CDH iff X is a G-delta zero-dimensional set or an interval.
Combining Select Blood-Based Biomarkers with Neuropsychological Assessment to Detect Mild Cognitive Impairment among Mexican Americans: A Molecular Neuropsychology Approach
Mexican Americans face a significant health disparity related to the development of Mild Cognitive Impairment (MCI) when compared to other ethnic groups. Recent work has documented the utility of utilizing blood-based biomarkers in the detection of amnestic MCI among this population. Efforts to enhance the utility of biomarkers in detecting disease through the inclusion of select neuropsychological measures, an approach termed Molecular Neuropsychology, has shown promise. The present study sought to utilize the molecular neuropsychology approach and examine biobanked serum samples as well as neuropsychological assessments from the Health and Aging Brain among Latino Elders (HABLE) study. Random Forest analyses were conducted to determine the proteomic profile of MCI. Then separate linear regression analyses were conducted to determine the variance accounted for by the biomarkers within the select neuropsychological measures. Trail Making Test Part B was identified as having the least amount of variance and was combined with top five biomarkers within the MCI proteomic profile to create a biomarker-cognitive profile for detecting disease presence. This same method was applied to the amnestic and non-amnestic forms of MCI. The overall biomarker-cognitive profile was shown to be 90% accurate in the detection of MCI, with no significant increase when demographic variables were included into the model. Among amnestic MCI cases, the detection accuracy of the biomarker-cognitive profile was 92% and increased to 94% upon inclusion of demographic variables.
Community of Inquiry Meets Critical Discourse Analysis (CDA): A CDA of Asynchronous Computer-Conference Discourse with Seminary Students in India
The purpose of this study was to better understand student learning in asynchronous computer-conference discourse (ASD) for non-native speakers of English in India through the Community of Inquiry (COI) framework. The study looked at ASD from an online course taught in the fall of 2015 to 25 students in a seminary in South India. All but one of the students were non-native speakers of English. The class consisted of 22 men and 3 women. Eight students spoke languages from the Dravidian family of languages (Malayalam, Tamil, Telegu and Kannada). Eight students were from the Northeastern states of Manipur, Nagaland and Tripura, where most languages are from the Sino-Tibetan family. Three students were native speakers of Indo-Aryan languages (Odiya and Assamese). Five students were from Myanmar representing several Sino-Tibetan languages. The COI is a framework used to understand learning in ASD, often used in online learning. To study the ASD of this group, critical discourse analysis (CDA) was used with the COI to capture the unique socio-cultural and linguistic conditions of this group. The study revealed that non-native speakers of English often reach the Exploration phase of learning but rarely show evidence of reaching the Resolution phase. This phenomenon was also observed in native English speakers as reported in the literature. Also, the structure of ASD showed that students took an examination approach to discussion shaped in part by their epistemology. This examination approach shaped how knowledge was constructed. CDA also showed that the discourse acquired an instructor-centered structure in which Resolution and Repair were initiated and finalized by the instructor. The study advances the COI framework by undergirding it with a theory of asynchronous discourse using critical discourse analysis and capturing cognitive, social and teaching presence phenomena for non-native speakers that were not observed through the traditional COI framework. These ...
Comparing Three Approaches for Handling a Fourth Level of Nesting Structure in Cluster-Randomized Trials
This study compared 3 approaches for handling a fourth level of nesting structure when analyzing data from a cluster-randomized trial (CRT). CRTs can include 3 levels of nesting: repeated measures, individual, and cluster levels. However, above the cluster level, there may sometimes be an additional potentially important fourth level of nesting (e.g., schools, districts, etc., depending on the design) that is typically ignored in CRT data analysis. The current study examined the impact of ignoring this fourth level, accounting for it using a model-based approach, and accounting it using a design-based approach on parameter and standard error (SE) estimates. Several fixed effect and random effect variance parameters and SEs were biased across all 3 models. In the 4-level model, most SE biases decreased as the number of level 3 clusters increased and as the number of level 4 clusters decreased. Also, random effect variance biases decreased as the number of level 3 clusters increased. In the 3-level and complex models, SEs became more biased as the weight level 4 carried increased (i.e., larger intraclass correlation, more clusters at that level). The current results suggest that if a meaningful fourth level of nesting exists, future researchers should account for it using design-based approach; the model-based approach is not recommended. If the fourth level is not practically important, researchers may ignore it altogether.
Comparison of the "Méthode Pour La Guitare" by Fernando Sor with the "Méthode Complète Pour La Guitare Par Ferdinand Sor, Rédigée Et Augmentée De Nombreux Exemples Et Leçons Suivis D'une Notice Sur La 7e Corde" by Napoléon Coste
The nineteenth century presents a great increase in publications of guitar methods. Most authors of the time published several versions of their works. Fernando Sor, perhaps the most prominent guitar composers of the time—whose Méthode is regarded today as the most important of the period—only published one edition. However, Napoleon Coste took on the task to do a second account. The literature reviewed shows substantial existing information regarding background, type of text, tone, and contents of Sor's work, but comparisons to date are not substantial. Therefore, there is a need to compare these two texts side by side to yield a complete view of their pairing. The existing negative views of Coste's edition hinder the importance of Coste's work as reference to Segovia's publication of Sor studies, and as a clearer pedagogical application of many of Sor's concepts which are sidetracked by his response to criticism and his elaborations in matters beyond his main subject matter. I provide a comprehensive review of Sor's method, an outline and a consideration of his concepts. Then I offer a complete English translation of Coste's method which is inexistent until now. The comparison follows pointing at differences and similarities. Results show that Coste clarifies and complements many of the principles in less text and simpler language. He modifies certain others either to approach Sor's practice or to depart to a newer standard. He offers his own lessons and sections to apply Sor's concepts. Coste's text heads towards a pedagogical synthesis of Sor's method, but it is incomplete because he omits some concepts without leading the readers to consult Sor. Coste's pedagogical and practical relevance is fundamental for modern standard techniques.
A Comprehensive Performance Guide for the Use of Advanced Technology in Euphonium Repertoire with Electronic Media through Analyses of Works by D. Edward Davis, Neal Corwell, and Lucy Pankhurst
Solos for euphonium with electronic media present the unique challenge of incorporating an active, physical involvement in the live accompaniment through sound-altering technology such as guitar pedals or digital processors. Instructions for this solo genre are often vague and demand a general knowledge of how to use non-traditional devices. Due to the lack of information available on newly-composed pieces for this medium, students and professionals easily overlook the artistic merit of electroacoustic music. This dissertation provides a comprehensive performance guide that aids in the set-up and operation of advanced technology and presents a methodical approach to performing common musical and technical challenges found in modern euphonium repertoire with electronic media. Included in this dissertation are tables of common audio vocabulary and images of connectors, safety precautions, equipment recommendations with performance settings, a list of required connectors, adapters, cables, speakers, and amplifiers, performance set up diagrams, background information, and analyses of both the technical and musical aspects of each piece. In the appendices are signal flow charts, visual illustrations of polar recording patterns, and an updated catalog of published and unpublished original, adapted, and arranged euphonium solos with live electronics and electronic media accompaniment between 1970 and 2017.
A Conjugate Arrangement for Measuring Commercial Viewing
Commercial viewing was measured by a conjugate arrangement for 1 female and 3 male participants. Reinforcing qualities were evaluated according to screen variations and ratings. Subjects changed the screen clarity via knob pressing either making the screen more or less transparent, translucent or opaque based on commercial interest. Results were conducive to participant attentiveness or indifference to commercial viewing. Experimenter was able to identify the commercials that grasped and maintained the participants' viewing behavior. Conceptually this conjugate arrangement could enhance eye tracking technology to improve marketing and advertising strategies. This experiment yield results that suggest a more concrete analysis of consumer response to visual stimuli that maintains attending.
Controlled Vocabularies in the Digital Age: Are They Still Relevant?
Keyword searching and controlled vocabularies such as Library of Congress subject headings (LCSH) proved to work well together in automated technologies and the two systems have been considered complimentary. When the Internet burst onto the information landscape, users embraced the simplicity of keyword searching of this resource while researchers and scholars seemed unable to agree on how best to make use of controlled vocabularies in this huge database. This research looked at a controlled vocabulary, LCSH, in the context of keyword searching of a full text database. The Internet and probably its most used search engine, Google, seemed to have set a standard that users have embraced: a keyword-searchable single search box on an uncluttered web page. Libraries have even introduced federated single search boxes to their web pages, another testimony to the influence of Google. UNT's Thesis and Dissertation digital database was used to compile quantitative data with the results input into an EXCEL spreadsheet. Both Library of Congress subject headings (LCSH) and author-assigned keywords were analyzed within selected dissertations and both systems were compared. When the LCSH terms from the dissertations were quantified, the results showed that from a total of 788 words contained in the 207 LCSH terms assigned to 70 dissertations, 246 of 31% did not appear in the title or abstract while only 8, or about 1% from the total of 788, did not appear in the full text. When the author-assigned keywords were quantified, the results showed that from a total of 552 words from304 author-assigned keywords in 86 dissertations, 50 or 9% did not appear in the title or abstract while only one word from the total of 552 or .18% did not appear in the full text. Qualitatively, the LCSH terms showed a hierarchical construction that was clearly designed for a print ...
A Convergence of LDPC Based on Eigenvalues
Low-density parity check (LDPC) codes are very popular among error correction codes because of their high-performance capacity. Numerous investigations have been carried out to analyze the performance and simplify the implementation of LDPC codes. Relatively slow convergence of iterative decoding algorithm affects the performance of LDPC codes. Faster convergence can be achieved by reducing the number of iterations during the decoding process. In this thesis, a new approach for faster convergence is suggested by choosing a systematic parity check matrix that yields lowest Second Smallest Eigenvalue Modulus (SSEM) of its corresponding Laplacian matrix. MATLAB simulations are used to study the impact of eigenvalues on the number of iterations of the LDPC decoder. It is found that for a given (n, k) LDPC code, a parity check matrix with lowest SSEM converges quickly as compared to the parity check matrix with high SSEM. In other words, a densely connected graph that represents the parity check matrix takes more iterations to converge than a sparsely connected graph.
Crossing Over: Essays on Ethnic Parties, Electoral Politics, and Ethnic Social Conflict
This dissertation analyzes several topics related to political life in ethnically divided societies. In chapter 2, I study the relationship between ethnic social conflict, such as protests, riots, and armed inter-ethnic violence, and bloc partisan identification. I find that protests have no effect on bloc support for political parties, riots increase bloc partisan identification, and that armed violence reduces this phenomenon. In chapter 3, I analyze the factors that influence the targeting of ethnic groups by ethnic parties in social conflict. I find some empirical evidence that conditions favorable to vote pooling across ethnic lines reduce group targeting by ethnic parties. In chapter 4, I analyze the effects of ethnic demography on ethnic party behavior. Through a qualitative analysis of party behavior in local elections in Macedonia, I find that ethnic parties change their strategies in response to changes in ethnic demography. I find that co-ethnic parties are less likely to challenge each other for power under conditions of split demography. In fact, under conditions of split demography, I find that co-ethnic parties have political incentives to unite behind a single party because intra-group competition jeopardizes the group's hold on power.
Crystallographic Complex Reflection Groups and the Braid Conjecture
Crystallographic complex reflection groups are generated by reflections about affine hyperplanes in complex space and stabilize a full rank lattice. These analogs of affine Weyl groups have infinite order and were classified by V.L. Popov in 1982. The classical Braid theorem (first established by E. Artin and E. Brieskorn) asserts that the Artin group of a reflection group (finite or affine Weyl) gives the fundamental group of regular orbits. In other words, the fundamental group of the space with reflecting hyperplanes removed has a presentation mimicking that of the Coxeter presentation; one need only remove relations giving generators finite order. N.V Dung used a semi-cell construction to prove the Braid theorem for affine Weyl groups. Malle conjectured that the Braid theorem holds for all crystallographic complex reflection groups after constructing Coxeter-like reflection presentations. We show how to extend Dung's ideas to crystallographic complex reflection groups and then extend the Braid theorem to some groups in the infinite family [G(r,p,n)]. The proof requires a new classification of crystallographic groups in the infinite family that fail the Steinberg theorem.
Cultural Humility, Religion, and Health in Lesbian, Gay, and Bisexual (LGB) Populations
The purpose of this study was to explore the religion – health link in a sample of adults and undergraduate students (N = 555) that identified as lesbian, gay, or bisexual (LGB), and to explore how perceptions of cultural humility of religious individuals and groups toward LGB individuals affect the relationship between religion and health. First, I found religious commitment among LGB individuals was positively correlated with satisfaction in life, but it was negatively correlated with physical health. Second, I found that cultural humility moderated the relationship between religious commitment and satisfaction in life for LGB individuals involved in a religious community. The lowest levels of satisfaction with life were found for individuals with low religious commitment and perceived the cultural humility of their religious community to be low. However, cultural humility did not moderate the relationship between religious commitment and mental and physical health outcomes. Third, I found cultural humility did not moderate the relationship between religious commitment and minority stress (i.e., internalized homophobia). Fourth, I found that cultural humility was a significant positive predictor of motivations to forgive a hurt caused by a religious individual. I conclude by discussing limitations, areas for future research, and implications for counseling.
A Decision-Making Model for Safe and Effective Use of Functional Analysis Procedures
While functional analysis provides the standard methodology for the assessment of problem behavior, procedures still pose potential risk when assessing severe problem behavior. Previous studies have examined several strategies to improve the efficiency of and reduce risks related to the functional analysis process. The purpose of the present series of studies was to replicate and extend previous research on the assessment and treatment of severe problem behavior for one participant diagnosed with an intellectual disability. By incorporating strategies within a systematic decision-making framework, functional analysis procedures were implemented to conduct the assessment of precursors, determine maintaining contingencies for severe problem behavior, and evaluate the effects of a treatment based on the results of a functional analysis.
Delivery of CRISPR/Cas9 into Blood Cells of Zebrafish: Potential for Genome Editing in Somatic Cells
Factor VIII is a clotting factor found on the intrinsic side of the coagulation cascade. A mutation in the factor VIII gene causes the disease Hemophilia A, for which there is no cure. The most common treatment is administration of recombinant factor VIII. However, this can cause an immune response that renders the treatment ineffective in certain hemophilia patients. For this reason a new treatment, or cure, needs to be developed. Gene editing is one solution to correcting the factor VIII mutation. CRISPR/Cas9 mediated gene editing introduces a double stranded break in the genomic DNA. Where this break occurs repair mechanisms cause insertions and deletions, or if a template oligonucleotide can be provided point mutations could be introduced or corrected. However, to accomplish this goal for editing factor VIII mutations, a way to deliver the components of CRISPR/Cas9 into somatic cells is needed. In this study, I confirmed that the CRISPR/Cas9 system was able to create a mutation in the factor VIII gene in zebrafish. I also showed that the components of CRISPR/Cas9 could be piggybacked by vivo morpholino into a variety of blood cells. This study also confirmed that the vivo morpholino did not interfere with the gRNA binding to the DNA, or Cas9 protein inducing the double stranded break.
Design, Synthesis and Optoelectronic Properties of Monovalent Coinage Metal-Based Functional Materials toward Potential Lighting, Display and Energy-Harvesting Devices
Groundbreaking progress in molecule-based optoelectronic devices for lighting, display and energy-harvesting technologies demands highly efficient and easily processable functional materials with tunable properties governed by their molecular/supramolecular structure variations. To date, functional coordination compounds whose function is governed by non-covalent weak forces (e.g., metallophilic, dπ-acid/dπ-base stacking, halogen/halogen and/or d/π interactions) remain limited. This is unlike the situation for metal-free organic semiconductors, as most metal complexes incorporated in optoelectronic devices have their function determined by the properties of the monomeric molecular unit (e.g., Ir(III)-phenylpyridine complexes in organic light-emitting diodes (OLEDs) and Ru(II)-polypyridyl complexes in dye-sensitized solar cells (DSSCs)). This dissertation represents comprehensive results of both experimental and theoretical studies, descriptions of synthetic methods and possible application allied to monovalent coinage metal-based functional materials. The main emphasis is given to the design and synthesis of functional materials with preset material properties such as light-emitting materials, light-harvesting materials and conducting materials. In terms of advances in fundamental scientific phenomena, the major highlight of the work in this dissertation is the discovery of closed-shell polar-covalent metal-metal bonds manifested by ligand-unassisted d10-d10 covalent bonds between Cu(I) and Au(I) coinage metals in the ground electronic state (~2.87 Å; ~45 kcal/mol). Moreover, this dissertation also reports pairwise intermolecular aurophilic interactions of 3.066 Å for an Au(I) complex, representing the shortest ever reported pairwise intermolecular aurophilic distances among all coinage metal(I) cyclic trimetallic complexes to date; crystals of this complex also exhibit gigantic luminescence thermochromism of 10,200 cm-1 (violet to red). From applications prospective, the work herein presents monovalent coinage metal-based functional optoelectronic materials such as heterobimetallic complexes with near-unity photoluminescence quantum yield, metallic or semiconducting integrated donor-acceptor stacks and a new class of Au(III)-based black absorbers with cooperative intermolecular iodophilic (I…I) interactions that sensitize the harvesting of all UV, all visible, and a broad spectrum of near-IR ...
"Developer"
A chapbook-length collection of poems.
Developing a Phylogeny Based Machine Learning Algorithm for Metagenomics
Metagenomics is the study of the totality of the complete genetic elements discovered from a defined environment. Different from traditional microbiology study, which only analyzes a small percent of microbes that could survive in laboratory, metagenomics allows researchers to get entire genetic information from all the samples in the communities. So metagenomics enables understanding of the target environments and the hidden relationships between bacteria and diseases. In order to efficiently analyze the metagenomics data, cutting-edge technologies for analyzing the relationships among microbes and communities are required. To overcome the challenges brought by rapid growth in metagenomics datasets, advances in novel methodologies for interpreting metagenomics data are clearly needed. The first two chapters of this dissertation summarize and compare the widely-used methods in metagenomics and integrate these methods into pipelines. Properly analyzing metagenomics data requires a variety of bioinformatcis and statistical approaches to deal with different situations. The raw reads from sequencing centers need to be processed and denoised by several steps and then be further interpreted by ecological and statistical analysis. So understanding these algorithms and combining different approaches could potentially reduce the influence of noises and biases at different steps. And an efficient and accurate pipeline is important to robustly decipher the differences and functionality of bacteria in communities. Traditional statistical analysis and machine learning algorithms have their limitations on analyzing metagenomics data. Thus, rest three chapters describe a new phylogeny based machine learning and feature selection algorithm to overcome these problems. The new method outperforms traditional algorithms and can provide more robust candidate microbes for further analysis. With the frowing sample size, deep neural network could potentially describe more complicated characteristic of data and thus improve model accuracy. So a deep learning framework is designed on top of the shallow learning algorithm stated above in order to further ...
Developing a Self-Respect Instrument to Distinguish Self-Respect from Self-Esteem
Throughout the scientific literature, researchers have referred to self-respect and self-esteem as being the same construct. However, the present study advocated that they exist as two distinct constructs. In this quantitative study, an instrument was developed to measure self-respect as a construct, and subsequently distinguish that self-respect is distinct from the construct of self-esteem. Exploratory factor analyses (EFA) indicated 32.60% of the variance was accounted for by the 11-item Jefferson Self-Respect instrument (JSR), which measured self-respect as a unidimensional construct. The reliability estimate of the scores from the JSR reached an acceptable α = .82. Fit indices (RMSEA = .031, SRMR = .037, CFI = .982, and TLI = .977) from the confirmatory factor analyses (CFA) signified a well-fitted hypothesized model of self-respect that existed as a unidimensional construct. Additionally, the CFA revealed that the construct of self-respect, and self-esteem was generally distinct, and the strength of the correlation between the two constructs was moderately positive (r = .62).
Developing Precipitation Hardenable High Entropy Alloys
High entropy alloys (HEAs) is a concept wherein alloys are constructed with five or more elements mixed in equal proportions; these are also known as multi-principle elements (MPEs) or complex concentrated alloys (CCAs). This PhD thesis dissertation presents research conducted to develop precipitation-hardenable high entropy alloys using a much-studied fcc-based equi-atomic quaternary alloy (CoCrFeNi). Minor additions of aluminium make the alloy amenable for precipitating ordered intermetallic phases in an fcc matrix. Aluminum also affects grain growth kinetics and Hall-Petch hardenability. The use of a combinatorial approach for assessing composition-microstructure-property relationships in high entropy alloys, or more broadly in complex concentrated alloys; using laser deposited compositionally graded AlxCrCuFeNi2 (0 < x < 1.5) complex concentrated alloys as a candidate system. The composition gradient has been achieved from CrCuFeNi2 to Al1.5CrCuFeNi2 over a length of ~25 mm, deposited using the laser engineered net shaping process from a blend of elemental powders. With increasing Al content, there was a gradual change from an fcc-based microstructure (including the ordered L12 phase) to a bcc-based microstructure (including the ordered B2 phase), accompanied with a progressive increase in microhardness. Based on this combinatorial assessment, two promising fcc-based precipitation strengthened systems have been identified; Al0.3CuCrFeNi2 and Al0.3CoCrFeNi, and both compositions were subsequently thermo-mechanically processed via conventional techniques. The phase stability and mechanical properties of these alloys have been investigated and will be presented. Additionally, the activation energy for grain growth as a function of Al content in these complex alloys has also been investigated. Change in fcc grain growth kinetic was studied as a function of aluminum; the apparent activation energy for grain growth increases by about three times going from Al0.1CoCrFeNi (3% Al (at%)) to Al0.3CoCrFeNi. (7% Al (at%)). Furthermore, Al addition leads to the precipitation of highly refined ordered L12 (γ′) and B2 precipitates in ...
Development and Analysis of a Mobile Node Tracking Antenna Control System
A wireless communication system allows two parties to exchange information over long distances. The antenna is the component of a wireless communication system that allows information to be converted into electromagnetic radiation that propagates through the air. A system using an antenna with a highly directional beam pattern allows for high power transmission and reception of data. For a directional antenna to serve its purpose, it must be accurately pointed at the object it is communicating with. To communicate with a mobile node, knowledge of the mobile node's position must be gained so the directional antenna can be regularly pointed toward the moving target. The Global Positioning System (GPS) provides an accurate source of three-dimensional position information for the mobile node. This thesis develops an antenna control station that uses GPS information to track a mobile node and point a directional antenna toward the mobile node. Analysis of the subsystems used and integrated system test results are provided to assess the viability of the antenna control station.
Development and Validation of Measures of Generalization of a Behavior Management Package
In order for the benefits of a behavior management skills training program to reach clients, caregivers must use the behavior management skills in the natural environment. The current study took place at a large residential facility for adults with disabilities, in which caregivers had received prior training in which they demonstrated behavior management skills and maintained those skills in contrived role plays. The current study represents a preliminary analysis of generalization of these skills in the natural environment; thus, a measurement system for when caregivers should demonstrate the tools was developed. The specific purpose of this study was to develop and evaluate a program to establish stimulus control over observers' measurement of appropriate behaviors. Researchers systematically developed and validated a measurement system of "good behaviors" that could be used across clients. The process of development and refinement of the measurement system is described. When the system was finalized, three observers' accuracy in using the system was assessed by comparing measured values to that of the code writer. Following feedback on individual instances of behavior, all observers scored the three target behaviors accurately. Ecological validity was assessed by surveying professionals at the facility and ecological validity results suggested a valid measurement system was developed.
Development of a Natural Fiber Mat Plywood Composite
Natural fibers like kenaf, hemp, flax and sisal fiber are becoming alternatives to conventional petroleum fibers for many applications. One such applications is the use of Non-woven bio-fiber mats in the automobile and construction industries. Non-woven hemp fiber mats were used to manufacture plywood in order to optimize the plywood structure. Hemp fiber mats possess strong mechanical properties that comparable to synthetic fibers which include tensile strength and tensile modulus. This study focuses on the use of hemp fiber mat as a core layer in plywood sandwich composite. The optimization of fiber mat plywood was done by performing a three factor experiment. The three factors selected for this experiment were number of hemp mat layers in the core, mat treatment of the hemp mat, and the glue content in the core. From the analysis of all treatments it was determined that single hemp mat had the highest effect on improving the properties of the plywood structure.
Development of a Targeted Protein Residue Analysis Approach in Archaeology
Liquid chromatography-mass spectrometry (LC-MS) based proteomic methods have provided archaeologists with a powerful tool for the discovery and identification of proteins within artifacts. Traditionally, discovery-based methods have utilized a non-targeted full mass scan method in an attempt to identify all proteins present within a given sample. However, increased sensitivity is often needed to target specific proteins in order to test hypotheses. Proteins present within archaeological materials present a unique challenge, as they are often subjected to a variety of chemical transformations both before and after burial. Any preserved proteins will be present within a complex mixture of compounds, and full mass scans often fail to detect less abundant proteins of interest. Consistent and reliable targeted methods are needed to detect protein biomarkers. Taphonomic experimentation was employed as a means to identify the effect of particular processes and conditions on the preservation of mare's milk proteins. In addition, three LC-MS methods were evaluated for their efficiency in identifying mare's milk-specific peptide biomarkers from experimental pottery samples. The ability to reliably detect the presence of these species-specific peptides can help provide evidence about past cultural groups, including the origins of dairying and animal domestication.
"Drum Music": A Performance Guide and Discussion of John Mackey's Influential Concerto for the Modern Percussionist
John Mackey is an influential and prolific composer of wind band literature. His focus on and exploration of the percussion section are defining characteristics of his compositional voice. Mackey's concerto for percussion and wind band, "Drum Music," is a perfect example of his exploitation of the myriad timbres available within the percussion family, and also serves to showcase the versatility required of a modern percussionist. This dissertation and accompanying lecture recital provide a comprehensive guide for performers of the work. Major aspects of Mackey's compositional approach are discussed with emphasis placed on his use of percussion throughout his works. Analysis and performance concerns are discussed for each of the concertos three movements, and information is provided on the reduced version of the work prepared as part of this study.
Dynamic Screening via Intense Laser Radiation and Its Effects on Bulk and Surface Plasma Dispersion Relations
Recent experimentation with excitation of surface plasmons on a gold film in the Kretschmann configuration have shown what appears to be a superconductive effect. Researchers claimed to see the existence of electron pairing during scattering as well as magnetic field repulsion while twisting the polarization of the laser. In an attempt to explain this, they pointed to a combination of electron-electron scattering in external fields as well as dynamic screening via intense laser radiation. This paper expands upon the latter, taking a look at the properties of a dynamic polarization function, its effects on bulk and surface plasmon dispersion relations, and its various consequences.
Educational Uplift along the US-Mexico Border: How Students, Families, and Educators Cultivate a College-Going Culture in Contested Terrain
Using critical race theory and LatCrit as conceptual frameworks, I conducted a qualitative instrumental case study of a cadre of self-identified Mexican-American and Hispanic college students who bring college knowledge, goodwill, and aid to their border town communities. The purpose of this study was to explore how college knowledge and other forms of academic capital are transmitted and co-constructed in the contested terrain of the borderlands. Primary data sources included semi-structured interviews, participant and non-participant observation, and personal artifacts (e.g. newspaper articles, college admissions essays, social media, etc.) collected from 17 full-time undergraduate student participants, 11 males and 6 females, ranging from 19 to 22 years old, who were active members of the Gates Millennium Scholars Program. Supplemental data sources included semi-structured interviews with 23 family members and 9 educators identified by student participants, as well as a review of public records regarding student participant's border town communities (e.g. newspaper articles, census data, educational statistics, etc.). Findings detail how this group of college students manages the 'scholar' distinction in their hometown and utilizes distinct methods to promote academic capital formation. Specifically, this study delineates the following four types of scholars: (1) pioneers, (2) guardians, (3) ambassadors, and (4) advocates. Ultimately, this research highlights the importance of college students' ingenuity in response to enduring system inequality in higher education, particularly along the U.S.-Mexico border, with implications for research theory, policy, and practice.
The Effect of Instructional Expenditures on College Readiness
With limited state and local funds as well as a growing student population, how elected decision makers allocate money to impact college readiness needs to be explored. The purpose of this research study was to explore the impact of instructional expenditures on educational outcomes. This multivariate multiple regression study specifically explored the impact of instructional expenditure ratios and per pupil instructional expenditures of every public school district in Texas on student performance college readiness indicators measured by state assessments (State of Texas Assessment of Academic Readiness [STAAR] Mathematics and English Language Arts [ELA] test scores) and national assessments (American College Test [ACT] and Scholastic Assessment Test [SAT] scores) over a 5-year period. Fifteen different regression models were established with various significant predictors of expenditures and revenue funds. These models explained up to 46% of the variance for college readiness scores over the 5-year period.
Effect of Surface Treatment on the Performance of CARALL, Carbon Fiber Reinforced Aluminum Joints
Fiber-metal laminates (FML) are the advanced materials that are developed to improve the high performance of lightweight structures that are rapidly becoming a superior substitute for metal structures. The reasons behind their emerging usage are the mechanical properties without a compromise in weight other than the traditional metals. The bond remains a concern. This thesis reviews the effect of pre-treatments, say heat, P2 etch and laser treatments on the substrate which modifies the surface composition/roughness to impact the bond strength. The constituents that make up the FMLs in our present study are the Aluminum 2024 alloy as the substrate and the carbon fiber prepregs are the fibers. These composite samples are manufactured in a compression molding process after each pre-treatment and are then subjected to different tests to investigate its properties in tension, compression, flexural and lap shear strength. The results indicate that heat treatment adversely affects properties of the metal and the joint while laser treatments provide the best bond and joint strength.
Eggplant Emoji
Eggplant Emoji is a documentary film that reveals a range of feminist perspectives on dick pics, sexting and online sexual harassment. Through intimate and hilarious interviews with women between the ages of 22 and 35, the film harnesses a collective voice that speaks back to the large and small ways patriarchy wields power in modern spaces, especially through sending unsolicited dick pics. By intertwining the testimonies of a dynamic group of female storytellers sitting amongst their close friends, the film provides candid and diverse commentary on this unique moment we are in, where the lines between private and public, online and offline are increasingly blurred. Until there are greater consequences, whether legal, social or otherwise, for men disrespecting women's choices and personal space, the domain of sexting is in a self-policing state and women are left to expend emotional labor to let men know why what they sent is unwanted or violating. Ultimately, the subjects' testimonials coalesce to provide suggestions for respectful, consensual sexting practices and fill in the gaps where sex education often neglects the importance of consent and communication altogether.
Elections and Authoritarian Rule: Causes and Consequences of Adoption of Grassroots Elections in China
This dissertation investigates the relationship between elections and authoritarian rule with a focus on the case of China's adoption of elections at the grassroots level. In this dissertation, I look at the incentives facing Chinese local governments in choosing between holding competitive elections or state-controlled elections, and how the selection of electoral rules shapes the public's preferences over political institutions and influences the citizens' political behaviors, especially voting in elections and participation in contentious activities. The overarching theme in this dissertation proposes that the sources and consequences of Chinese local elections are conditioned on the state-owned resources and the governing costs. When the amount of state-owned resources to rule the local society is limited, the paucity of resources will incentivize authoritarian governments to liberalize grassroots elections to offset the governance costs. The various levels of election liberalization will lead to different consequences in the public's political behavior. An abundance of state-owned resources not only discourages rulers from sharing power with the local society, but also supplies the rulers with strong capacity to obtain loyalty from voters when elections are adopted. As a result, elections under authoritarian governments with an abundance of state-owned resources will see more loyalist voters than elections with authoritarian governments with fewer state-owned resources. In addition, the varieties of election practices will exert impacts on public opinion toward the authoritarian government: awareness of elections will enhance public trust in the government and decrease the public's intention to challenge the incumbents' authority while at the same time increasing the public's faith in the institutions, thereby encouraging the public to adopt official channels to air their grievances. The analysis of the village-level as well as individual-level survey data and cases lends empirical supports to the argument. First, I find that the governing costs—measured by the size of labor force—are ...
Electrochemical Deposition of Nickel Nanocomposites in Acidic Solution for Increased Corrosion Resistance
The optimal conditions for deposition of nickel coating and Ni-layered double hydroxide metal matrix composite coatings onto stainless steel discs in a modified all-sulfate solutions have been examined. Nickel films provide good general corrosion resistance and mechanical properties as a protective layer on many metallic substrates. In recent years, there has been interest in incorporation nano-dimensional ceramic materials, such as montemorillonite, into the metal matrices to improve upon the corrosion and mechanical properties. Layered double hydroxides have been used as corrosion enhancer in polymer coatings by increasing mechanical strength and lowering the corrosion rate but until now, have not been incorporated in a metal matrix by any means. Layered double hydroxides can be easily synthesized in a variety of elemental compositions and sizes but typically require the use of non-polar solvents to delaminate into nanodimensional colloidal suspensions. The synthesis of a Zn-Al LDH has been studied and characterized. The effects of the non-polar solvents dimethylformamide and n-butanol on the deposition and corrosion resistance of nickel coatings from a borate electrolyte bath have been studied, a nickel-LDH nanocomposite coating has been synthesized by electrochemical deposition and the corrosion resistance has been studied. Results indicate an improvement in corrosion resistance for the coatings with minimal change in the nickel matrix's internal strain and crystallite size.
An Engagement Bout Analysis of the Effects of Effort
Operant response rate can be viewed as bouts, periods of alternating engagement and disengagement with ongoing schedules of reinforcement. Relatively few studies have examined the role of force and effort on engagement bouts. Moreover, those examining effort have used switch closure devices to define the response. Switch closures tend to overestimate the effect of effort because increasing the force requirement excludes low-force responses that previously activated the switch. In the present study, we examined the effects of effort using a force transducer, which allows us to record criterion responses that meet the force requirement and subcriterion responses that do not. The current study was conducted using four male Sprague Dawley rats. Each rat was run through a series of four conditions, each with a different combination of variable interval schedules (VI 30s, VI 120s) and force requirements (5.6g, 32g). Log survivor analyses of bout structure showed that increased force requirements decreased the rate of bout initiations. Additionally, when log-survivor functions were computed using only criterion responses, shifts in the function were less extreme than when all measured responses were used; the latter finding suggests exclusion of "subcriterion" responses in prior work has overestimated the effects of force on bout structure
Evaluating the Role of UV Exposure and Recovery Regimes in PAH Photo-Induced Toxicity
Polyaromatic hydrocarbons (PAHs) are contaminants synthesized through incomplete combustion of carbon based substances. PAHs are known to be photodynamic and toxicity increases exponentially when in contact with ultraviolet radiation (UV). The effect of UV absent recovery periods and potential for latent toxicity during photo-induced toxicity are previously unknown and are not included within the toxicity model. Results of equal interval tests further support the current reciprocity model as a good indicator of PAH photo-induced toxicity. Interval test results also indicate a possible presence of time-dependent toxicity and recovery thresholds and should be included into toxicity risk assessments. Moreover, results of latent effects assays show that latent mortality is a significant response to PAH photo-induced toxicity and should be included into toxicity risk assessments. The present research demonstrates that UV exposure time rate is a significant driving force of PAH photo-induced toxicity.
Evocative Foreshadowing: The Motivic Construction in "The Legend of Two Rings"
In this thesis, I demonstrate how I use leitmotif in a programmatic context in my original orchestral suite, The Legend of Two Rings.
The Evolution of Brand Co-Creation: Models and Exploration of Stakeholders' Motivations
Co-creation is an emerging phenomenon that occurs when two or more parties work together to create value. Co-creation, which is a key component to service dominant logic, is present in business to business, business to consumer, and consumer to consumer processes. This dissertation will focus on the business to consumer (and consumer to business) co-creation relationship. Much of the current business to consumer co-creation literature is qualitative in nature, with quantitative work just now beginning to emerge. As such, there is still much about the phenomenon of co-creation that is not understood. When looking at co-creation in the context of brand management, even less is known. In today's age of digital interaction where consumers are gaining more power on a daily basis, practitioners and academics should understand the motivations for consumers to engage brands in co-creation and what the outcomes of these co-creation partnerships are. Because of this, the dissertation contains three essays with the purpose of (1) identifying the motivations for co-creation from consumer and brand perspectives, (2) exploring each of these motivators on their individual relationship to the outcome of co-creation, and (3) understanding how the perceived ability to influence a brand impacts the outcomes of co-creation. Essay 1, titled "Co-creation of brand identities: consumer and industry influence and motivations," aims to develop an understanding of the phenomena of co-creation and how the practice is used in shaping brand identities. Two studies are undertaken to provide insight into co-creation. First, a qualitative study is used to gain insight from key decision makers with responsibility for a brand. Second, a study of millennial consumers is used to develop the antecedents of consumer motivations of co-creation of brand identities. This essay then presents a comprehensive framework that encompasses two models (industry and consumer) of brand identity co-creation. Much of the ...
The Evolution of Learning Technologies within the UNC German Consortium 2000-2016: A Hermeneutic Phenomenlogical Analysis of German Faculty Member Experiences
Beginning in 2000 and continuing today, the University of North Carolina (UNC) German Consortium offers online German courses to undergraduate students across sixteen of the seventeen UNC public universities. The delivery of online classes differs per faculty member and little previous research investigated the UNC German Consortium's learning technologies. This dissertation investigates the evolution of learning technologies within the UNC German Consortium over the last sixteen years among German faculty from different UNC public universities. Seven faculty and one administrator shared their experiences through interviews. The methodology for this research was hermeneutic phenomenology. Interviewees shared their experiences with learning technology and teaching in the UNC German Consortium including how learning technologies changed over time. Interviews were transcribed, coded, and analyzed to deduce themes. Themes included the importance of the North Carolina Research Education Network (NC REN) for teaching German online, an asynchronous versus synchronous debate, how professors taught in synchronous courses, the importance of learning management systems (LMS) systems, the resilient characteristics of UNC German Consortium faculty, and the need for continual learning as an instructor.
Evolution of Precipitates and Their Influence on the Mechanical Properties of β-Titanium Alloys
Over the last few decades, body-centered-cubic (bcc) beta (β) titanium alloys have largely been exploited as structural alloys owing to the richness in their microstructural features. These features, which lead to a unique combination of high specific strength and ductility, excellent hardenability, good fatigue performance, and corrosion resistance, make these alloys viable candidates for many applications, including aerospace, automobile, and orthopedic implants. The mechanical properties of these alloys strongly depend on the various phases present; which can be controlled by thermomechanical treatments and/or alloy design. The two most important and studied phases are the metastable ω phase and the stable α phase. The present study focuses on the microstructural evolution and the mechanical behavior of these two phases in a model β-Ti alloy, binary Ti-12wt. %Mo alloy, and a commercial β-Ti alloy, β-21S. Microstructures containing athermal and isothermal ω phases in the binary Ti-12wt. %Mo alloy are obtained under specific accurate temperature controlled heat treatments. The formation and the evolution of the ω-phase based microstructures are investigated in detail via various characterization techniques such as SEM, TEM, and 3D atom probe tomography. The mechanical behavior was investigated via quasi-static tensile loading; at room and elevated temperatures. The effect of β phase stability on the deformation behavior is then discussed. Similar to the Ti-12wt. %Mo, the formation and the evolution of the athermal and isothermal ω phases in the commercial β-21S alloy was studied under controlled heat treatments. The structural and compositional changes were tracked using SEM, TEM, HR-STEM, and 3D atom probe tomography (3D-APT). The presence of additional elements in the commercial alloy were noted to make a considerable difference in the evolution and morphology of the ω phase and also the mechanical behavior of the alloys. The Portevin-Le Chatelier (PLC) like effect was observed in iii this alloy at ...
Extended String Techniques and Special Effects in Arnold Schoenberg's String Quartet No. 1 and Its Significance in Chamber Music Literature
Arnold Schoenberg's String Quartet No. 1, Op. 7 stands out as being the first chamber music piece to use a vast number and variety of extended string techniques within one composition. This paper examines a brief history of extended string techniques in chamber music, analyses the unique ways in which Schoenberg applied extended string techniques to manipulate motives in his Op. 7 quartet, and ultimately shows that Schoenberg's use of extended string techniques influenced future composers to employ even more extended techniques and special effects in their own twentieth-century chamber music.
Fabrication of Photonic Crystal Templates through Holographic Lithography and Study of their Optical and Plasmonic Properties in Aluminium Doped Zinc Oxide
This dissertation focuses on two aspects of integrating near-infrared plasmonics with electronics with the intent of developing the platform for future photonics. The first aspect focuses on fabrication by introducing and developing a simple, single reflective optical element capable of high–throughput, large scale fabrication of micro- and nano-sized structure templates using holographic lithography. This reflective optical element is then utilized to show proof of concept in fabricating three dimensional structures in negative photoresists as well as tuning subwavelength features in two dimensional compound lattices for the fabrication of dimer and trimer antenna templates. The second aspect focuses on the study of aluminum zinc oxide (AZO), which belongs to recently popularized material class of transparent conducting oxides, capable of tunable plasmonic capabilities in the near-IR regime. Holographic lithography is used to pattern an AZO film with a square lattice array that are shown to form standing wave resonances at the interface of the AZO and the substrate. To demonstrate device level integration the final experiment utilizes AZO patterned gratings and measures the variation of diffraction efficiency as a negative bias is applied to change the AZO optical properties. Additionally efforts to understand the behavior of these structures through optical measurements is complemented with finite difference time domain simulations.
Formation Control of Multi-Agent Systems
Formation control is a classical problem and has been a prime topic of interest among the scientific community in the past few years. Although a vast amount of literature exists in this field, there are still many open questions that require an in-depth understanding and a new perspective. This thesis contributes towards exploring the wide dimensions of formation control and implementing a formation control scheme for a group of multi-agent systems. These systems are autonomous in nature and are represented by double integrated dynamics. It is assumed that the agents are connected in an undirected graph and use a leader-follower architecture to reach formation when the leading agent is given a velocity that is piecewise constant. A MATLAB code is written for the implementation of formation and the consensus-based control laws are verified. Understanding the effects on formation due to a fixed formation geometry is also observed and reported. Also, a link that describes the functional similarity between desired formation geometry and the Laplacian matrix has been observed. The use of Laplacian matrix in stability analysis of the formation is of special interest.