The a. c. thin film electroluminescent (ACTFEL) devices are of scientific interest due to their applications in large area, flat panel displays. Of particular interest to the research community is the mechanism of electron transport and luminance in these devices. Toward this end, a physical model and a mathematical model for SrS:Cu ACTFEL Devices were developed and published earlier by our group. The purpose of this thesis is to obtain a qualitative and quantitative match between experiment and theory. A brief summary of the model can be found here [1]. Effects of variation in drive parameters in experimental steady state measurements, and analysis of VIL (Voltage-Current-Luminance) plots for different simulated device and drive parameters are performed. The effects of voltage amplitude, activator concentration, interface energy levels, and critical field for dipole collapse were studied. The plots matched qualitatively in that all major experimental features were produced in the simulated waveforms. The measured and the simulated peak currents are 72.5 mA/cm2 and 66.42 mA/cm2 for VA = 123 V. Experimental and theoretical charge transferred per pulse were 2.75 C/cm2 and 2.26 C/cm2. Peak experimental and simulated luminance values for VA = 123 V were 531 cd/m2 and 49150 cd/m2. Total experimental and simulated luminance values for VA = 123 V case were 6.2 cd/m2 and 561.2 cd/m2 respectively. The large difference is attributed to the loss factors such as optical losses (due to total internal reflection), scattering of electrons by impurities in the bulk phosphor layer, and concentration quenching; these have not been incorporated in the model yet.

The purpose of this thesis is to contribute to the understanding of SrS based ACTFEL devices. Better understanding of the processes in the host phosphor will give us the possibility to design more efficient blue emitting ACTFEL devices. Towards this aim, a physical model, that describes the optoelectronic processes taking place in the phosphor, was developed and analytical equations were written. The analytical model was numerically simulated and the plots of flux flowing through the device and luminance output by the device were obtained. Experiments were performed to obtain the plots of current flowing through the device and luminance output by the device. These plots were then qualitatively compared and the results of comparisons are presented. The numerical simulations qualitatively verify the accuracy of the model. The drive parameters were varied in order to study its effect on the VIL characteristics of the device. On varying the voltage applied to the device and its rise and fall times, a good insight was obtained into device behavior. Simulations were also performed to obtain responses to qualitatively match the experimentally obtained responses. Various What-If scenarios have been studied by varying the device parameters. These studies have indicated the importance of these parameters in determining device performance.

The first result of this thesis is a partial result in the direction of Steinberg's Conjecture. Steinberg's Conjecture states that any planar graph without cycles of length four or five is three colorable. Borodin, Glebov, Montassier, and Raspaud showed that planar graphs without cycles of length four, five, or seven are three colorable and Borodin and Glebov showed that planar graphs without five cycles or triangles at distance at most two apart are three colorable. We prove a statement that implies the first of these theorems and is incomparable with the second: that any planar graph with no cycles of length four through six or cycles of length seven with incident triangles distance exactly two apart are three colorable. The third and fourth chapters of this thesis are concerned with the study of Pfaffian orientations. A theorem proved by William McCuaig and, independently, Neil Robertson, Paul Seymour, and Robin Thomas provides a good characterization for whether or not a bipartite graph has a Pfaffian orientation as well as a polynomial time algorithm for that problem. We reprove this characterization and provide a new algorithm for this problem. In Chapter 3, we generalize a preliminary result needed to reprove this theorem. Specifically, we show that any internally 4-connected, non-planar bipartite graph contains a subdivision of K3,3 in which each path has odd length. In Chapter 4, we make use of this result to provide a much shorter proof using elementary methods of this characterization. In the fourth and fifth chapters we investigate flat embeddings. A piecewise-linear embedding of a graph in 3-space is flat if every cycle of the graph bounds a disk disjoint from the rest of the graph. We provide a structural theorem for flat embeddings that indicates how to build them from small pieces in Chapter 5. In Chapter 6, we present a class of flat graphs that are highly non-planar in the sense that, for any fixed k, there are an infinite number of members of the class such that deleting k vertices leaves the graph non-planar.

Violists today have much music from which to choose. Works exist for unaccompanied viola, viola and piano, and chamber ensemble including viola. Many of these works, especially those from this century, were written specifically for the viola. In addition, a number of earlier original viola works have been recently rediscovered. There are not, however, any great number of concertos for viola and orchestra.According to David Daniels' Orchestral Music: A Handbook, there are nineteen works in the general repertoire for viola and orchestra. Closer examination of these works reveals that few measure up to the standard of quality found in the concerto literature for other instruments. Violists, therefore, continue to search for new and rewarding music to play.The purpose of this study is to supplement the concerto repertoire for the viola with a recently uncovered work, the Concerto in E -flat Major by Joseph Schubert.The concerto is put in a historical and analytical context. Discussions of eighteenth-century Dresden's musical life and Schubert's life and works provide a context for understanding the Concerto. A history of the instrumental parts chronicles the Concerto's two versions. A carefully prepared musical text (based on manuscript parts from the Sachsische Landesbibliothek Dresden) is presented, with discussion of sources and emendations. / School of Music

No description available.

O presente estudo propõe-se responder à questão de investigação: como podemos abordar conceitos de geometria plana com estudantes de sexto ano por meio de confecção de objetos manipulativos digitais e não-digitais, permitindo que estes se reconheçam como fabricantes de seu próprio conhecimento? A pesquisa apresenta uma proposta de atividade em que estudantes foram convidados a serem fabricantes de seu próprio conhecimento, mais especificamente de conhecimentos de geometria plana. Por meio da confecção e manipulação de objetos digitais e não-digitais, os estudantes transformaram a sala de aula em uma Fábrica de Matemática. O estudo foi desenvolvido durante o ano de 2016, com uma turma de sexto ano de uma escola municipal de Sapucaia do Sul, no horário regular de aula. Apoiada na teoria do construcionismo de Seymour Papert, na pedagogia da autonomia de Paulo Freire e na aprendizagem cooperativa e por equipes de Jean Piaget, e utilizando o estudo de caso como metodologia, o presente trabalho apresenta uma experiência de abordagem de conceitos de geometria plana – área, perímetro, paralelismo e perpendicularismo, entre outros – que permitiu o reconhecimento, por parte dos estudantes, da possibilidade de se tornarem agentes ativos na construção dos seus conhecimentos. Além disso, percebeu-se quanto aos resultados, que quando lhes são oferecidas diferentes oportunidades para aprendizagem, os estudantes podem se tornar sujeitos críticos, autônomos e produtores de conhecimento. / The present study proposes to answer the research question: how can we approach concepts of flat geometry with sixth-year students by making digital and non-digital manipulative objects, allowing them to recognize themselves as manufacturers of their own knowledge? The research presents a proposal of activity in which students were invited to be manufacturers of their own knowledge, more specifically of knowledge of flat geometry. Through the making and manipulation of digital and non-digital objects, students transformed the classroom into a Mathematics Factory. The study was developed during 2016, with a sixth grade class from a municipal school in Sapucaia do Sul, at regular school hours. Based on the construction theory of Seymour Papert, Paulo Freire 's pedagogy of autonomy and cooperative and team learning by Jean Piaget, and using the case study as methodology, the present work presents an experience of approaching concepts of flat geometry - area, perimeter, parallelism and perpendicularism, among others - that allowed the students to recognize the possibility of becoming active agents in the construction of their knowledge. In addition, it was perceived as to the results, that when they are offered different opportunities for learning, students can become critical, autonomous subjects and producers of knowledge.

The thesis is focused on the development prices of rent in Czech Budweis and is divided into several parts. The first part is focused on the history of inhabitation and history of rents. The second part is devoted to explaining basic concepts that are important for my work. In the next section of the literary research, I pay attention to itself lease and the rent, where these concepts and facts related with them, described in more detail. In the practical part there is processed the information from questionnaire, information from Správa domů s.r.o. and still focus on apartments, that have been over the past few years, realized rent through estate agents. From the processed data are created synoptic charts and graphs, together with commentaries and evaluation.

O presente estudo propõe-se responder à questão de investigação: como podemos abordar conceitos de geometria plana com estudantes de sexto ano por meio de confecção de objetos manipulativos digitais e não-digitais, permitindo que estes se reconheçam como fabricantes de seu próprio conhecimento? A pesquisa apresenta uma proposta de atividade em que estudantes foram convidados a serem fabricantes de seu próprio conhecimento, mais especificamente de conhecimentos de geometria plana. Por meio da confecção e manipulação de objetos digitais e não-digitais, os estudantes transformaram a sala de aula em uma Fábrica de Matemática. O estudo foi desenvolvido durante o ano de 2016, com uma turma de sexto ano de uma escola municipal de Sapucaia do Sul, no horário regular de aula. Apoiada na teoria do construcionismo de Seymour Papert, na pedagogia da autonomia de Paulo Freire e na aprendizagem cooperativa e por equipes de Jean Piaget, e utilizando o estudo de caso como metodologia, o presente trabalho apresenta uma experiência de abordagem de conceitos de geometria plana – área, perímetro, paralelismo e perpendicularismo, entre outros – que permitiu o reconhecimento, por parte dos estudantes, da possibilidade de se tornarem agentes ativos na construção dos seus conhecimentos. Além disso, percebeu-se quanto aos resultados, que quando lhes são oferecidas diferentes oportunidades para aprendizagem, os estudantes podem se tornar sujeitos críticos, autônomos e produtores de conhecimento. / The present study proposes to answer the research question: how can we approach concepts of flat geometry with sixth-year students by making digital and non-digital manipulative objects, allowing them to recognize themselves as manufacturers of their own knowledge? The research presents a proposal of activity in which students were invited to be manufacturers of their own knowledge, more specifically of knowledge of flat geometry. Through the making and manipulation of digital and non-digital objects, students transformed the classroom into a Mathematics Factory. The study was developed during 2016, with a sixth grade class from a municipal school in Sapucaia do Sul, at regular school hours. Based on the construction theory of Seymour Papert, Paulo Freire 's pedagogy of autonomy and cooperative and team learning by Jean Piaget, and using the case study as methodology, the present work presents an experience of approaching concepts of flat geometry - area, perimeter, parallelism and perpendicularism, among others - that allowed the students to recognize the possibility of becoming active agents in the construction of their knowledge. In addition, it was perceived as to the results, that when they are offered different opportunities for learning, students can become critical, autonomous subjects and producers of knowledge.

No description available.

abstract: Tesla turbo-machinery offers a robust, easily manufactured, extremely versatile prime mover with inherent capabilities making it perhaps the best, if not the only, solution for certain niche applications. The goal of this thesis is not to optimize the performance of the Tesla turbine, but to compare its performance with various working fluids. Theoretical and experimental analyses of a turbine-generator assembly utilizing compressed air, saturated steam and water as the working fluids were performed and are presented in this work. A brief background and explanation of the technology is provided along with potential applications. A theoretical thermodynamic analysis is outlined, resulting in turbine and rotor efficiencies, power outputs and Reynolds numbers calculated for the turbine for various combinations of working fluids and inlet nozzles. The results indicate the turbine is capable of achieving a turbine efficiency of 31.17 ± 3.61% and an estimated rotor efficiency 95 ± 9.32%. These efficiencies are promising considering the numerous losses still present in the current design. Calculation of the Reynolds number provided some capability to determine the flow behavior and how that behavior impacts the performance and efficiency of the Tesla turbine. It was determined that turbulence in the flow is essential to achieving high power outputs and high efficiency. Although the efficiency, after peaking, begins to slightly taper off as the flow becomes increasingly turbulent, the power output maintains a steady linear increase. / Dissertation/Thesis / M.S. Mechanical Engineering 2012