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An Historical Analysis of Rule and Policy Changes in the Texas University Interscholastic League One-Act Play Contest, 1986-2006, and the Results of Those Changes: Administrator and Teacher Perceptions

Description: The University Interscholastic League (UIL) One-Act Play Contest is a competition where similarly sized Texas schools present an 18-40 minute play usually adjudicated by a single judge. At each level of competition the judge awards individual acting awards as well as selecting two productions to advance to the next level of competition. After the awards are announced the judge gives an oral critique to each of the schools. Because of the wide participation and diversity of plays produced, certain rules and guidelines have been adopted to ensure safety, allow for equity, satisfy legal standards, and make the running of the contest practical. These rules can be modified to achieve positive outcomes and improved educational results. Changes in the rules of a UIL contest are in accordance with stated educational objectives of the UIL. Occasionally, however, modifications in procedures raise questions. The problem of this study was to determine, from the perceptions of administrators and teachers, whether significant modifications in the rules and policies for the UIL One-Act Play Contest over a time span of 20 years have had impacts on the goals and procedures of the contest. The study utilized a qualitative approach through historical analysis and a survey to answer two research questions. Historical analysis identified the six modifications in the UIL OAP over the years 1986-2006. The survey instrument determined the impact of these changes on the goals and procedures of the contest. Based on the responses of the survey the competition experience has been enhanced by recent changes.
Date: May 2010
Creator: Stevens, David Todd

Development of a Test Blueprint for a Hospitality Management Capstone Course to Measure Programmatic Student Learning Outcomes

Description: The purpose of this study was to develop a test blue-print for a hospitality management capstone course to measure programmatic student learning outcomes. A total of 50 hospitality industry professionals and hospitality management faculty were interviewed through focus group discussions, and a post-focus group survey was conducted to determine a weighted percentage for each of the nine determined content domains. A test blueprint was developed from the weighted proportions determined by this study and a process by which other educational institutions could follow to establish a consistent and accurate evaluation method for a capstone course was described.
Date: May 2010
Creator: Stevenson, Jackie M.

Ida Gotkovsky's Eolienne Pour Flute et Harpe in Theory and Practice: A Critical Analysis

Description: This dissertation addresses specific theoretical issues within Gotkovsky's Eolienne. She was a student of Messiaen, and his influence is evident in Eolienne, but at the same time, Gotkovsky's compositional voice is both personally distinctive and reflects l'esprit de temps of the twentieth century Parisian musical world. The research provides extensive analytical insight into Gotkovsky's musical language in Eolienne, specifically her use of symmetrical scales, emphasis on timbre, and formal constructs. Because there are limited scholarly resources available on the subject of flute and harp chamber music, and a small amount of biographical information on Gotkovsky, this dissertation is a significant contribution within the area of chamber music for flute, both historically and theoretically. It provides an analysis of Gotkovsky's musical language and the analysis gives performers access to musical-theoretical information previously unavailable.
Date: May 2010
Creator: Surman, Patricia Jovanna

Social, Demographic, and Institutional Effects on African American Graduation Rates in U.S. Colleges and Universities.

Description: Improving the retention and graduation of African Americans and other minority groups in higher education is an important but highly politicized issue on college and university campuses. Prior studies emphasize the relationship between minority retention and achievement, cultural diversity, and racial policies and climates at predominantly White colleges and universities in the United States. In response to the need for further research, the effects of institutional actions related to diversity, minority group and African American retention, and social integration initiatives on African American graduation rates were examined for a national sample of United States (U.S.) colleges and universities. From a potential list of 7,018 colleges and universities, 2,233 met the inclusion criteria for the study. But necessary and complete information from national directories and the census could only be found for the final sample of 1,105. After dropping 30 outliers, several multiple regression analyses identified the institutional actions, social, and demographic factors that best predicted graduation rates. Public U.S. colleges and universities located in the Midwest region had lower African American graduation rates than private colleges and universities located in the South. Higher African American graduation rates occurred in colleges and universities with Black cultural centers, higher first-year retention rates, higher women enrollment rates, a higher number of student organizations, and Division III athletic programs. Colleges and universities located in a town had higher African American graduation rates than those located in a city, suburb, or rural area.
Date: May 2010
Creator: Wright, LaQueta L.

Design and Implementation of Large-Scale Wireless Sensor Networks for Environmental Monitoring Applications

Description: Environmental monitoring represents a major application domain for wireless sensor networks (WSN). However, despite significant advances in recent years, there are still many challenging issues to be addressed to exploit the full potential of the emerging WSN technology. In this dissertation, we introduce the design and implementation of low-power wireless sensor networks for long-term, autonomous, and near-real-time environmental monitoring applications. We have developed an out-of-box solution consisting of a suite of software, protocols and algorithms to provide reliable data collection with extremely low power consumption. Two wireless sensor networks based on the proposed solution have been deployed in remote field stations to monitor soil moisture along with other environmental parameters. As parts of the ever-growing environmental monitoring cyberinfrastructure, these networks have been integrated into the Texas Environmental Observatory system for long-term operation. Environmental measurement and network performance results are presented to demonstrate the capability, reliability and energy-efficiency of the network.
Date: May 2010
Creator: Yang, Jue

A Schenkerian Analysis of Beethoven's E Minor Piano Sonata, Opus 90

Description: This thesis examines the history and origins of Beethoven's E minor Piano Sonata and examines the possibility of the programmatic conception of the work. Dedicated to Beethoven's friend Count Moritz Lichnowsky, the sonata may have been inspired by the Count's illicit affair with his future wife, the singer and actress Josefa Stummer. Providing a thorough Schenkerian analysis of both movements, the inner harmonic structure of the composition is revealed and explained. The author also investigates and details the unpublished original analyses of the composition by Heinrich Schenker, Erika Elias, and Hans Weisse. Both English and German language sources are incorporated into a comprehensive examination of Beethoven's Piano Sonata, op. 90.
Date: May 2010
Creator: Treber, Stefan L.

A Case Study of Undergraduate Course Syllabi in Taiwan

Description: Higher education in Taiwan has been influenced by U.S. and Western practices, and syllabi represent one means to verify this. However, limited research exists in Taiwan on course syllabi and on similarities of syllabi with practices in other countries. In the U.S. as the paradigm shifted from teaching to learning and to the learning-centered context, scholars argued that syllabi should be learning-centered. Given the assumption that higher education in Taiwan is similar to U.S. higher education and the call for a learning-centered context, this qualitative research examined 180 undergraduate syllabi at a public university in Taiwan with a (traditional) syllabus component template and a learning-centered syllabus component template derived from the literature in the U.S. to describe (1) the contents of syllabi, and (2) the extent that syllabi in Taiwan were congruent to U. S. syllabus component templates. Syllabi at this university were highly congruent with the (traditional) syllabus component template and were congruent at the medium level with the learning-centered component template. About 90% of syllabi included 8 of 10 major components. Additional findings included: 70% of faculty were male, and 30% were female; more than 75% of the faculty earned their doctoral degrees from the United States or Europe; gender made no difference on inclusion of major components for both templates; there was no difference in inclusion of components on both templates for faculty who earned their doctoral degrees from the U.S. or Taiwan; a high percentage (80%) of college courses adopted English textbooks published in the U.S.; some differences existed and use of English in the syllabus and on components included in the syllabi. Based on these syllabi, it is evident that syllabi in Taiwan represent course planning and organization congruent to recommended practices in the United States.
Date: May 2010
Creator: Tung, Yao-Tsu

Musical Arrangements and Questions of Genre: A Study of Liszt's Interpretive Approaches

Description: Through his exceptional creative and performing abilities, Franz Liszt was able to transform compositions of many kinds into unified, intelligible, and pleasing arrangements for piano. Nineteenth-century definitions of "arrangement" and "Klavierauszug," which focus on the process of reworking a composition for a different medium, do not adequately describe Liszt's work in this area. His piano transcriptions of Schubert's songs, Berlioz's Symphonie fantastique and the symphonies of Beethoven are not note-for-note transcriptions; rather, they reinterpret the originals in recasting them as compositions for solo piano. Writing about Liszt's versions of Schubert's songs, a Viennese critic identified as "Carlo" heralded Liszt as the creator of a new genre and declared him to have made Schubert's songs the property of cultured pianists. Moreover, Liszt himself designated his work with Berlioz's Symphonie fantastique and the symphonies of Beethoven "Partitions de piano": literally, piano scores. As is well known, concepts of genre in general create problems for musicologists; musical arrangements add a new dimension of difficulty to the problem. Whereas Carl Dahlhaus identifies genre as a tool for interpreting composers' responses to the social dimension of music in the fabric of individual compositions, Jeffrey Kallberg perceives it as a "social phenomenon shared by composers and listeners alike." The latter concept provides a more suitable framework for discussing the genre of transcriptions, for their importance derives in large part from relationships between the original and the derivative works, both as constructed by Liszt and perceived by critics and audiences. During the nineteenth and early twentieth century's, Liszt's transcriptions of songs and symphonies were construed as both compositions for pianists and subsets of the originals. Consequently, these compositions should be studied for their own musical value as well as for the light that they shed on the original works. Liszt's transcriptions are derivative and at the same ...
Date: May 2010
Creator: Van Dine, Kara Lynn

An Analysis of UNT Commuting Patterns

Description: Academic institutions have recently organized to address their campus' greenhouse gas emissions. Along those lines, the University of North Texas (UNT) pledged to minimize the campus' environmental impact, and conducted a transportation survey in May 2009. The analyses confirm that commuting to campus was the second highest source (29%) of UNT's greenhouse gas emissions, following purchased electricity (48%). Students, faculty and staff drive over 89 million miles per year, 84% of which comes from students. Forty‐two percent of student driving trips originate in the primary and secondary core areas surrounding Denton, which are partially served by buses. However, because these core areas are in close proximity to the campus, they contribute only 8% of the total student driving distance. Beyond the Denton core, the inner periphery of Denton County contributes another 22% of driving mileage. Students living in the outer periphery (outside Denton County) contribute the remaining 70% of total driving distance, and carpooling is currently their only alternative.
Date: May 2010
Creator: Waskey, Susan L.

Evaluating the Effectiveness of a Comprehensive Staff Training Package for Behavioral Interventions for Children with Autism

Description: The effectiveness of behavioral interventions for the treatment of young children with autism has been well documented in professional literature. The success of these procedures, however, depends on the fidelity of implementation and proper training of the therapist. The purpose of this study was to evaluate a 125-skill, comprehensive staff training package that involved a graduated sequence of teaching. In addition to changes in skills, social validity and training time were also assessed. Results indicate that correct demonstration of skills increased following training, incorrect implementation decreased, teachers rated the procedures favorably, and the total training took between 20 and 32.5 hours for over 120 skills to reach mastery criteria. A discussion of the results as well as implications for future research is also provided.
Date: May 2010
Creator: Weinkauf, Sara Marie

Student Engagement Theory: A Comparison of Jesuit, Catholic, and Christian Universities

Description: This research study analyzed the results of the Jesuit Universities Consortium in comparison with the results of the Catholic Colleges and Universities and the Council for Christian Colleges Consortia as measured by the 2005 National Survey of Student Engagement (NSSE) in order to determine and identify any statistically significant differences between the consortia. One-way ANOVA analyses and Tukey HSD post hoc comparisons were conducted on the data from freshmen/first year students and seniors/fourth year students on each of the five clusters of the NSSE to determine any statistically significant difference and, subsequently, the effect size of any found differences. The study found that there were statistically significant differences on the following: 1) freshmen/first year students in the Jesuit Universities Consortium and the freshmen/first year students in the Council for Christian Colleges and Universities Consortium on the NSSE cluster of Academic Challenge, 2) freshmen/first year students in the Jesuit Universities Consortium and the freshmen/first year students in the Catholic Colleges and Universities Consortium on the NSSE cluster of Enriching Educational Experiences, 3) freshmen/first year students in the Jesuit Universities Consortium and the freshmen/first year students in the Council for Christian Colleges and Universities Consortium on the NSSE cluster of Supportive Campus Environment, 4) seniors/fourth year students in the Jesuit Universities Consortium and the seniors/fourth year students in the Catholic Colleges and Universities Consortium on the NSSE cluster of Active and Collaborative Learning, and 5) seniors/fourth year students in the Jesuit Universities Consortium and the seniors/fourth year students in both of the Catholic Colleges and Universities and the Council for Christian Colleges and Universities Consortia on the NSSE cluster of Supportive Campus Environment. While statistically significant differences were found in the aforementioned analyses, effect sizes were small for all. Future research studies, including longitudinal studies, are needed to fully investigate levels of ...
Date: May 2010
Creator: Williamson, Robin Marie

Examining the Origins of Sociology: Continuities and Divergences Between Ibn Khaldun, Giambattista Vico, August Comte, Ludwig Gumplowicz, and Emile Durkheim

Description: This thesis examines the extent to which Ibn Khaldun can legitimately be considered a founding father of sociology. To pursue this research, Khaldun's theoretical framework will be compared with four Western scholars: Auguste Comte, Emile Durkheim, Giambattista Vico, and Ludwig Gumplowicz. This paper begins with an Introduction (Chapter I), followed by a general overview of Khaldun's work (Chapter II). Next, Khaldun's work is compared to that of Auguste Comte (Chapter III), Emile Durkheim (Chapter IV), Ludwig Gumplowicz (Chapter V) and Giambattista Vico (Chapter VI). In each of these chapters, Khaldun is compared and contrasted to the other social theorist, illustrating their similarities and considering their differences. Finally, in Chapter VII, I put forth conclusions that consider the extent to which Khaldun can validly be considered a founding father of sociology.
Date: May 2010
Creator: Soyer, Mehmet

Retirees' Attitudes Toward Mental Illness Treatment: A Life-Course Perspective

Description: This purpose of this dissertation was to examine the attitudes of retirees toward mental illness treatment. Secondary data from the Survey Research Center at the University of North Texas was utilized for this study. The focus was on the influence that gender, income, education, race/ethnicity, personal experience, fear, goodwill, and social control might have had on retirees' attitudes toward mental illness treatment. An n = 225 was selected out of the existing data to serve as the sample population. Binary logistic regression was utilized to analyze the data. Results indicated that the obtained significant findings were consistent with existing literature.
Date: May 2010
Creator: Starkey, Thomas Wayne, Jr.

A Study of Student's Perceptions of Blended Learning Environments at a State-Supported Postsecondary Institution

Description: The purpose of this study was to conduct exploratory research regarding students' perceptions of blended learning environments at a state supported postsecondary institution. Specifically investigated were students' overall perceptions of blended learning environments, the reasons they chose to take a blended course, and whether generational differences existed in students' affected perceptions. An electronic survey was distributed to students enrolled in blended learning courses at the end of the spring 2009 term.
Date: May 2010
Creator: Shaw, Joanna G.

Determining Factors that Influence High School Principal Turnover Over a Five Year Period

Description: The purpose of this study was to determine the effects of salary, compensation and benefits, accountability, job stress, increased instructional responsibilities, changes in student demographics, lack of support, politics, advancement opportunities and promotion on tenure and turnover among high school principals in the state of Texas. The participants in the study included 60 Texas high school principals who left a high school principalship for a different high school principalship within the past 5 years. The participants completed the Texas Principal Survey and data were analyzed using binary logistic regression. The data indicated that salary, compensation and benefits was a significant factor in predicting an increase in the odds of principal turnover for principals who had been in their prior principalship 5 or more years over principals who had been in their prior principalship less than 5 years. Additionally, advancement opportunities was a significant factor in predicting a decrease in the odds of principal turnover for principals who had been in their prior principalship 5 or more years over principals who had been in their prior principalship less than 5 years. Responses from an open ended question asking principals why they left their prior principalship suggested that principals left for reasons including new challenges, lack of support and family. The results of this study support the need for continued research in the area of principal turnover and provide insight to district superintendents, school boards and principals.
Date: May 2010
Creator: Sheppard, Rebecca Replogle

An Analysis of Interrater Agreement Between the Motivation Assessment Scale (MAS), Questions About Behavioral Function (QABF), and Analog Assessment Outcomes

Description: An analysis of interrater agreement across multiple respondents on anecdotal assessments was compared with experimental functional analysis outcomes for correspondence. Experiment 1 evaluated the agreement of multiple respondents on the function of problem behavior for 22 individuals across 42 target behaviors using the Motivation Assessment Scale (MAS) and the Questions About Behavioral Function (QABF). Results showed agreement on the primary maintaining consequence for 4 or 5 of the 5 respondents in 52% (22/42) of the individual's target behaviors with the MAS and 57% (24/42) with the QABF. Experiment 2 examined whether correspondence occurred between the anecdotal assessment results and experimental functional analysis (EFA) results for 7 individuals selected from Experiment 1. Correspondence between the QABF assessment and the EFA was found for 6 of 7 participants, and 4 of the 7 showed correspondence between the EFA and the MAS. This study showed that the QABF had higher correspondence with analog assessments than the MAS thus, supporting the previous findings of Paclawskyj et al. (2001).
Date: May 2010
Creator: Smith, Carla Michelle

Fathom's Edge

Description: Investigating elements of the creative process in the work of three poets: James Wright, Gjertrud Schnackenberg, and Pegeen Kelly. Each poet deploys a different method for access to those experiences that lie at the edge of accessible language. Each method is discussed and its deployment illustrated. Wright leads us from the sensory world to the supersensual. Schnackenberg makes use of the formal device of the fairy tale. Kelly immerses in the logic of dreams. Drawing on Elaine Scarry's theory of the imagination, the case is made that the poetic act is a dialectic between the poet and the sensory world, in which perception and imagination are equally important.
Date: May 2010
Creator: Sweeney, Mark

Effects of Tasks on Information-Seeking Behavior in a Police Work Environment in the Context of Criminal Intelligence

Description: Although dominant effects of tasks on individuals' information-seeking behavior is accepted by many scholars, a limited number of studies has been conducted to reveal the nature of the relationship between tasks and information-seeking behavior. In their studies, some earlier researchers categorized tasks according to their complexity while others did the same according to the specifications of tasks. Two of the groundbreaking researchers in this area are Katriina Byström and Kalervo Järvelin who contributed to the understanding of the relationship between task complexity and information-seeking behavior. However, their findings also need empirical support for theory growth. In response to this need, this study attempts to test Byström and Järvelin's findings through a research using different research methods and applied in a police work environment. Other than providing empirical support for theory growth, this research is also expected to contribute to the understudied area of police information-seeking behavior. Both qualitative and quantitative data were collected from the participants who came from traffic, homicide, and anti-terrorism divisions of Ankara, Eskisehir, and Kirikkale Police Departments in Turkey. The participants identified terrorism cases as the most complex cases to solve, followed by homicide and traffic accident cases. Differences in the information-seeking behavior of three groups of police officers were examined through qualitative and quantitative data analysis. Oneway ANOVA technique and post hoc comparisons were used to analyze the quantitative data. In addition to shedding light on information-seeking behavior of police officers investigating related cases in Turkey, the results provided support for Byström and Järvelin's findings. For instance, the officers investigating more complex tasks used significantly more information sources than the others, while the use of external information sources was significantly higher in more complex cases.
Date: May 2010
Creator: Tatil, Serkan

Native American Elements in Piano Repertoire by the Indianist and Present-Day Native American Composers

Description: My paper defines and analyzes the use of Native American elements in classical piano repertoire that has been composed based on Native American tribal melodies, rhythms, and motifs. First, a historical background and survey of scholarly transcriptions of many tribal melodies, in chapter 1, explains the interest generated in American indigenous music by music scholars and composers. Chapter 2 defines and illustrates prominent Native American musical elements. Chapter 3 outlines the timing of seven factors that led to the beginning of a truly American concert idiom, music based on its own indigenous folk material. Chapter 4 analyzes examples of Native American inspired piano repertoire by the "Indianist" composers between 1890-1920 and other composers known primarily as "mainstream" composers. Chapter 5 proves that the interest in Native American elements as compositional material did not die out with the end of the "Indianist" movement around 1920, but has enjoyed a new creative activity in the area called "Classical Native" by current day Native American composers. The findings are that the creative interest and source of inspiration for the earlier "Indianist" compositions was thought to have waned in the face of so many other American musical interests after 1920, but the tradition has recently taken a new direction with the success of many new Native American composers who have an intrinsic commitment to see it succeed as a category of classical repertoire. Native American musical elements have been misunderstood for many years due to differences in systems of notation and cultural barriers. The ethnographers and Indianist composers, though criticized for creating a paradox, in reality are the ones who saved the original tribal melodies and created the perpetual interest in Native American music as a thematic resource for classical music repertoire, in particular piano repertoire.
Date: May 2010
Creator: Thomas, Lisa Cheryl

The Influence of Japanese Composers on the Development of the Repertoire for the Saxophone and the Significance of the Fuzzy Bird Sonata by Takashi Yoshimatsu

Description: The history of the saxophone and its development as a performance medium in Japan is short when compared with other European countries and the United States. In this short history, the saxophone performance level in Japan has increased dramatically. At the same time, compositions for the saxophone by Japanese composers have gained more popularity in the world as can be seen in the program of the World Saxophone Congress and the North American Saxophone Alliance conference. The saxophone history in Japan, including contributions of Arata Sakaguchi (1910-1997), Ryo Noda (b.1948), and Nobuya Sugawa (b.1961), is discussed in order to understand the increase of performances of pieces for saxophone by Japanese composers. The success of many original compositions, especially those that incorporate the synthesis of Eastern and Western music, is another significant element examined in this document. Yoshimatsu approaches music for classical saxophone as a new genre. He seeks all possible sounds that the saxophone can create - beautiful tone to "noise like" - in his compositions. The blending of other musical styles in one piece is one of Yoshimatsu's compositional styles, which can be observed in Fuzzy Bird Sonata; however, he does not limit himself to a single style. This unique style with some technical challenges attracts saxophonists and audiences. An analysis of Fuzzy Bird Sonata is provided in order to have a better understanding of the piece and to address performance practice issues. Also various interpretations are examined by comparing available recordings of Sugawa, Nicolas Prost, and Rob Buckland.
Date: May 2010
Creator: Hanafusa, Chiaki

Comparison of Heteranthera Dubia (Jacq.) MacM.-associated Macroinvertebrates Between Georgraphical Regions in the United States

Description: Macroinvertebrates associated with the aquatic plant, water stargrass (Heteranthera dubia), were sampled from 12 waterbodies in four regions of the United States from June to August 2005. Taxa richness, evenness, and diversity were lowest in the Lower Midwest (LMW) region, and higher in Northern sites, especially the Upper Midwest (UMW), and Northeast (NE). While relative abundance varied from site to site and region to region, utilization of the plant by functional groups remained fairly constant. Collector-gatherers consistently comprised the largest portion of invertebrates sampled. The shredder/ herbivore functional group comprised an average of 17 % of total groups. Through an exhaustive literature review, it was found that shredder/ herbivores of water stargrass have not been reported in the literature. Because of this, the herbivore group was analyzed separately and consisted of 2,383 specimens representing 23 species. The most common groups were Rhopalosiphum sp., Nectopsyche spp. and chironomids. No differences were found in herbivore diversity or evenness between sampling regions, but species richness was significantly different.
Date: May 2010
Creator: Harms, Nathan Earl

Modulation of the Coelomic Fluid Protein Profile in the Earthworm, Lumbricus Terrestris, After Exposure to Copper as Copper Sulfate

Description: Proteomic techniques were used to analyze the protein profile of earthworm, Lumbricus terrestris, coelomic fluid collected by either whole body dissection method or the coelomic cavity puncture method. Data demonstrated that collection of coelomic fluid using the coelomic cavity puncture method protocol resulted in a 32% reduction, 377 +/- 4.5 vs 253+/- 19.9 (p=0.0007), in the number of individual proteins. It was determined that the coelomic cavity puncture method yielded a "cleaner" preparation, one less contaminated with extraneous proteins from intestinal tissue, gut contents, and body wall materials. This protocol was used in all later studies. The same proteomic techniques were used to evaluate the effects that exposure to Cu (1.0 μg/cm2) as CuSO4 had on the earthworm coelomic fluid profile. Comparison of protein profile from exposed earthworms demonstrated a significant reduction in the number of proteins expressed (184 ± 2.64 vs 253 ±19.9 p=0.0192) when compared to control organisms. Cu exposure also resulted in a modulation of the protein profile with treated earthworms expressing 47 new proteins that were not identified in unexposed worm coelomic fluid. Additionally, 116 proteins found in coelomic fluid collected from normal worms were absent in Cu exposed organisms. Finally, 137 proteins were conserved or found in both control and exposed organisms; however of these proteins, 24 were up-regulated, 105 were down-regulated, and 8 were unchanged as a result of Cu exposure.
Date: May 2010
Creator: Herring, Reese

Sensitization of Lanthanides and Organic-Based Phosphorescence via Energy Transfer and Heavy-Atom Effects

Description: The major topics discussed are the phosphorescence sensitization in the lanthanides via energy transfer and in the organics by heavy atom effects. The f-f transitions in lanthanides are parity forbidden and have weak molar extinction coefficients. Upon complexation with the ligand, ttrpy (4'-p-Tolyl-[2,2':6',2"]-terpyridine) the absorption takes place through the ligand and the excitation is transferred to the lanthanides, which in turn emit. This process is known as "sensitized luminescence." Bright red emission from europium and bright green emission from terbium complexes were observed. There is ongoing work on the making of OLEDs with neutral complexes of lanthanide hexafluoroacetyl acetonate/ttrpy, studied in this dissertation. Attempts to observe analogous energy transfer from the inorganic donor complexes of Au(I) thiocyanates were unsuccessful due to poor overlap of the emissions of these systems with the absorptions of Eu(III) and Tb(III). Photophysics of silver-aromatic complexes deals with the enhancement of phosphorescence in the aromatics. The heavy atom effect of the silver is responsible for this enhancement in phosphorescence. Aromatics such as naphthalene, perylene, anthracene and pyrene were involved in this study. Stern Volmer plots were studied by performing the quenching studies. The quenchers employed were both heavy metals such as silver and thallium and lighter metal like potassium. Dynamic quenching as the predominant phenomenon was noticed.
Date: May 2010
Creator: Arvapally, Ravi K.

EEG, Alpha Waves and Coherence

Description: This thesis addresses some theoretical issues generated by the results of recent analysis of EEG time series proving the brain dynamics are driven by abrupt changes making them depart from the ordinary Poisson condition. These changes are renewal, unpredictable and non-ergodic. We refer to them as crucial events. How is it possible that this form of randomness be compatible with the generation of waves, for instance alpha waves, whose observation seems to suggest the opposite view the brain is characterized by surprisingly extended coherence? To shed light into this apparently irretrievable contradiction we propose a model based on a generalized form of Langevin equation under the influence of a periodic stimulus. We assume that there exist two different forms of time, a subjective form compatible with Poisson statistical physical and an objective form that is accessible to experimental observation. The transition from the former to the latter form is determined by the brain dynamics interpreted as emerging from the cooperative interaction among many units that, in the absence of cooperation would generate Poisson fluctuations. We call natural time the brain internal time and we make the assumption that in the natural time representation the time evolution of the EEG variable y(t) is determined by a Langevin equation perturbed by a periodic process that in this time representation is hardly distinguishable from an erratic process. We show that the representation of this random process in the experimental time scale is characterized by a surprisingly extended coherence. We show that this model generates a sequence of damped oscillations with a time behavior that is remarkably similar to that derived from the analysis of real EEG's. The main result of this research work is that the existence of crucial events is not incompatible with the alpha wave coherence. In addition to this important ...
Date: May 2010
Creator: Ascolani, Gianluca