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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Some Properties And Conserved Quantities Of The Short Pulse Equation

Erbas, Kadir Can 01 February 2008 (has links) (PDF)
Short Pulse equation derived by Schafer and Wayne is a nonlinear partial differential equation that describes ultra short laser propagation in a dispersive optical medium such as optical fibers. Some properties of this equation e.g. traveling wave solution and its soliton structure and some of its conserved quantities were investigated. Conserved quantities were obtained by mass conservation law, lax pair method and transformation between Sine-Gordon and short pulse equation. As a result, loop soliton characteristic and six conserved quantities were found.
12

Calculation Of Phase Diagrams And The Thermodynamic Quantities From The Mean Field Models Close To Phase Transitions In Molecular And Liquid Crystals

Sen, Sema 01 February 2009 (has links) (PDF)
This study gives our calculations for the temperature-pressure and temperature-concentration phase diagrams using the mean field models applied to ammonium halides (NH4Cl, ND4Cl), ammonium sulfate ((NH4)2SO4/H2O), lithium potassium rubidium sulfate (LiK1-xRbxSO4), potassium pyrosulfate-potassium hydrogensulfate (K2S2O7-KHSO4), cholestanyl myristate-cholesteryl myristate (CnM-CrM), cholestanyl myristate-cholesteryl oleate (CnM-CO), benzene (C6H6) and ice. The phase line equations are derived from the free energies expanded in terms of the order parameters and they are fitted to the experimental data. Some thermodynamic quantities are calculated close to phase transitions in these crystalline systems. We also calculate the specific heat CV using the Raman frequency shifts for NH4Br on the basis of an Ising model close to the lambda-phase transition. A linear relationship is obtained between the specific heat CP and the frequency shifts (1/v)(dv/dT)P near the lambda-point in NH4Br.
13

Critical Behaviour Of The Thermodynamic Quantities For The Thermotropic And Ferroelectric Liquid Crystals Close To The Phase Transitions

Kilit, Emel 01 February 2011 (has links) (PDF)
The specific heat Cp has been showed at various temperatures in the literature, which shows a sharp increase labeled as the lambda-transition at the critical temperature. This transition has been observed previously among the phases of solid-nematic-isotropic liquid in p-azoxyanisole (PAA) and anisaldazine (AAD), and among the phases of solid-smectic-cholesteric-isotropic liquid in cholesteryl myristate (CM). In this thesis work, we analyze the experimental data for the temperature dependence of Cp and the thermal expansion alpha_p and also pressure dependence of alpha_p by a power-law formula. From the analysis of pressure dependence of alpha_p, we calculate the temperature dependencies of specific heat Cp and of the isothermal compressibility kappa_T for the phase transitions considered in PAA, AAD and CM. Our calculations for the temperature dependence of the p and kappa_T can be compared with the experimental data when available in the literature. Polarization, tilt angle and the dielectric constant have been reported in the literature at various temperatures close to the solid-smectic C*-smectic A-isotropic liquid transition in the ferroelectric liquid crystals of A7 and C7. The mean field model with the free energy expanded in terms of the order parameters (polarization and tilt angle) has been reported in the literature previously. In this thesis work, we apply the mean field model first time by fitting the expressions derived for the temperature dependence of the polarization, tilt angle and the dielectric constant to the experimental data for A7 and C7 from the literature. Since the mean field model studied here describes adequately the observed behaviour of A7 and C7, the expressions for the temperature dependence of the polarization, tilt angle and the dielectric constant which we derive, can also be applied to some other ferroelectric liquid crystals to explain their observed behaviour.
14

Calculation Of The Thermodynamic And Spectroscopic Quantities In Molecular Crystals Close To The Phase Transitons

Dilan, Kavruk 01 February 2011 (has links) (PDF)
We study in this thesis work the spectroscopic and thermodynamic quantities of some substances such as ammonium halides (NH4Cl, NH4I), ferroelectric crystals of tris-sarcosine calcium chloride (TSCC), tris-sarcosine calcium bromide (TSCB), organic compounds of carbon tetrachloride (CCl4) and s-triazine (C3N3H3) close to the phase transitions. Various physical and chemical properties of those materials have been measured near the critical points and have been reported in the literature. In this study, the spectroscopic parameters of the frequency shifts, intensity and bandwidths are calculated as functions of temperature or pressure near the phase transitions in ammonium halides using the experimental data from the literature. The spectroscopic parameters are related to the crystal volume and the specific heat in these compounds. The thermodynamic quantities of the specific heat, thermal expansion and the isothermal compressibility are also calculated in the solid and liquid phases of carbon tetrachloride using the experimental data. In another part of this thesis work, we analyze the temperature dependence of the spontaneous polarization and the dielectric susceptibility at fixed pressures for TSCC and TSCB by using the experimental data from the literature. The temperature dependence of the damping constant for the s-triazine is also calculated here close to the I-II transition. We use the theoretical models on the basis of the observations in the literature to calculate the critical behaviour of these physical quantities and we compare the results with the observed data. Various experimental studies in the literature give us the opportunity to find the proper way of fitting the calculated and observed results. This study gives us the chance of a better understanding of the critical behavior of the studied materials by verifying the values of some critical exponents and the types of transitions as expected by different theoretical models.
15

Um estudo sobre a falta de padronização no uso de grandezas físicas em um curso de Engenharia Elétrica e Eletrônica / A study of the lack of standardization in the use of physical quantities on a course of Electrical and Electronic Engineering

Mattiazzo, Bruno Pagliarani [UNESP] 18 December 2015 (has links)
Submitted by Bruno Pagliarani Mattiazzo (bruno.mattiazzo@gmail.com) on 2016-04-08T17:40:02Z No. of bitstreams: 1 Um estudo sobre a falta de padronização no uso de grandezas físicas em um curso de Engenharia Elétrica e Eletrônica.pdf: 743772 bytes, checksum: 0dde4ea3cc894abf55715498dbb753b0 (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2016-04-08T20:49:12Z (GMT) No. of bitstreams: 1 mattiazzo_bp_me_prud.pdf: 1045556 bytes, checksum: 67a1efed622abbb5161f3d28d675ad4a (MD5) / Made available in DSpace on 2016-04-08T20:49:12Z (GMT). No. of bitstreams: 1 mattiazzo_bp_me_prud.pdf: 1045556 bytes, checksum: 67a1efed622abbb5161f3d28d675ad4a (MD5) Previous issue date: 2015-12-18 / O ensino de Física deve ser melhorado e aprimorado em diversos âmbitos do sistema educacional, inclusive nas universidades. A maioria dos da Engenharia iniciam o curso sem estar devidamente preparados e com um grande déficit conceitual Física e Matemática. Já, nas próprias Faculdades, existe um desencontro de informações entre o que é ensinado de Física, de acordo com os conteúdos já conhecidos e aqueles utilizados no dia a dia do engenheiro já formado. Neste trabalho serão trabalhadas formas de repassar estes conteúdos padronizando a notação utilizada. No presente estudo também é discutidas formas para que os professores possam abordar esses conceitos e conseguir o máximo de aproveitamento dentro da sala de aula. Para a coleta de dados foi aplicados um questionário aos docentes de engenharia elétrica e eletrônica da Fundação Educacional de Votuporanga e dois questionários aos alunos destes mesmos cursos; aula teórica que abordou os principais conflitos na utilização das grandezas físicas foi também ministrada. Nos questionários, os docentes ressaltaram a importância de uma padronização no ensino das grandezas físicas nos cursos de engenharia, assim como as dificuldades no uso dessas grandezas físicas entre os alunos. Nos questionários aplicados aos alunos, a sua grande maioria apresentou déficit na conceitualização das grandezas físicas. Se faz necessária uma padronização no ensino das grandezas físicas nos materiais didáticos e na linguagem utilizada pelos docentes. / The teaching of physics should be improved and enhanced in various areas of the education system, including in universities. Many students begin an engineering degree without being properly prepared and with a great conceptual deficit in physics. This dissertation discussed the misleading ways in which the physical quantities are taught to students in engineering courses and used in the professional scope of these students, thus generating difficulties in learning and improvement of these future engineers. In the present study it is also discussed a way that teachers can address these concepts to achieve maximum use within the classroom. For data collection were applied a questionnaire to electrical and electronic engineering professors and two questionnaires to students of these courses and imposed a lecture that addressed the main conflicts in the use of results. By analyzing the data it was found that all teachers reported the importance of standardization in the teaching of physical quantities in engineering courses, as well as witnessed difficulties in the use of physical quantities among students. In questionnaires given to students it was noticeable that the vast majority of students presented a deficit in the conceptualization of results. So it follows that if a standardization is needed in the teaching of physical quantities in teaching materials and language used by teachers.
16

O surgimento dos números irracionais / The emergence of irrational numbers

José Souto Sobrinho Filho 25 August 2015 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Este é um trabalho de pesquisa sobre um conjunto de números (irracionais) que é pouco trabalhado no ensino básico de matemática. Foi uma procura muito interessante e enriquecedora, pois encontrei matemáticos e historiadores com visões bem diferentes. Muitos deles não aceitavam este novo conjunto. Para Leopold Kronecker, só existia o conjunto dos números inteiros. Já para Cantor e Dedekind, o aparecimento dos irracionais foi extremamente importante para o desenvolvimento da matemática, abrindo novos horizontes. Menciono aqui um pouco da vida e da obra de alguns matemáticos que se envolveram com os números irracionais. Tratamos ainda da descoberta dos incomensuráveis, ou seja, como iniciou-se o problema da incomensurabilidade, e do retângulo áureo e sua importância em outras áreas. O trabalho mostra também dois grupos de números que não são mencionados quando ensinamos equações algébricas, que são os números algébricos e os números transcendentes, assim como teoremas essenciais para a prova da transcendência dos irracionais especiais e . Por fim, proponho uma aula para uma turma do 3 ano do Ensino Médio com o objetivo de mostrar a irracionalidade de alguns números, usando os teoremas pertinentes / This is a research about a set of numbers (irrationals) that is little explored in secondary school mathematics teaching. It was a very interesting and enriching search, because quite contrary facts were found. Several 19th century mathematicians did not accept this new set of numbers. To Leopold kronecker, only the set of the integers existed. To Cantor and Dedekind, the irrational numbers were extremely important for the development of mathematics, opening new horizons. I also mention the life and work of some mathematicians who were involved with the irrational numbers the discovery of the incommensurability was iniciated. The golden rectangle and its importance in other areas. The work also presents two groups of numbers that are not mentioned when algebraic equations are taught, the algebraic numbers and transcendental numbers. Essential theorems for the proof of the special irrational numbers e . Finnaly, I propose a lesson to a 3rd year high school class in order to show the irrationality of some numbers, using the relevant theorems
17

Implementação de Grandezas Operacionais na Monitoração Individual e de Área / Implementation of new operational quantities in the Individual and area monitoring

Carla da Costa Guimarães 10 October 2000 (has links)
Neste trabalho implementamos as grandezas operacionais no sistema de monitoração de área e individual. Determinamos a combinação ideal dos detectores termoluminescentes para constituírem os monitores de radiação como sendo: dois de fluoreto de cálcio (CaF2), um envolto em filtro de chumbo de (0,50 ± 0,05) mm e outro sem filtro e um de fluoreto de lítio TLD-100, também sem filtro. Aproveitamos a propriedade termoluminescente desses detectores, qual seja a de emissão de luz em intensidade proporcional à dose de radiação recebida, quando eles são aquecidos. A grandeza final avaliada é o equivalente de dose ambiental H*(10) e direcional H(10,) para fins de monitoração de área e o equivalente de dose pessoal Hp(10) para monitoração individual. Para tanto, estudos foram realizados irradiando os monitores no ar no primeiro caso e na frente de um fantoma de PMMA preenchido com água no segundo caso. Para avaliar o desempenho dos monitores de radiação eles foram submetidos a testes de linearidade da resposta com a dose, dependência angular e dependência energética. Uma análise detalhada dos resultados obtidos mostrou que todos os valores dos equivalentes de dose obtidos em testes de desempenho estão dentro dos limites estabelecidos por normas internacionais, com 95% de nível de confiança. Para o monitor escolhido obtivemos para a razão [H(10)determinado/H(10)nominal ± desvio] no caso de equivalente de dose ambiental e pessoal respectivamente os valores: (1,02 ± 0,11) e (0,97 ± 0,25). Os desvios foram calculados com o método t de student, considerando o intervalo que contém o valor nominal com 95% de probabilidade. / Operational quantities have been implemented to be applied in individual and area routine monitoring against external radiation exposure. This procedure is based on the use of an ideal combination of thermoluminescent detectors inside a monitor: two pellets of CaF2, one covered by a lead filter of (0,50 ± 0,05) mm and another one without filter and one TLD-100 without filter too. The operational quantities studied for area monitoring are the ambient and directional dose equivalent, H*(10) and H(10,), respectively and for individual monitoring, the personal dose equivalent, Hp(10). To evaluate the personal dose equivalent, all the experiments were performed irradiating the monitor on a slab water phantom made of PMMA walls with outer dimensions 30x30x15 cm, (a substitute of ICRU sphere four-element tissue phantom) completely full of water. Area monitors were irradiated in free air without any phantom. In general, an operational quantity H is determined from the basic physical quantity kerma free-in-air by means of conversion coefficients. The blind performance testing of monitors was performed after type testing, including analysis of the linearity of the response with the dose, the angular and energy dependence. The results of these investigations agree with the values recommended by international organisations within 95 % of confidence level. The ratios (H(10)evaluated/H(10)nominal ± deviation) obtained for ambient and personal dose equivalente are respectively (1,02 ± 0,11) and (0,97 ± 0,25), with the monitor above quoted. The error was estimated with the method of t-student, considering 95 % confidence level.
18

Do conhecimento (matemático) primeiro: grandezas e medidas no centro das atenções / On the previous knowledge: quantities and measures in the core of the attention

Regina Santana Alaminos de Freitas 19 March 2009 (has links)
Este trabalho, um estudo do tipo qualitativo, teve como objetivo compreender de que modo os educadores matemáticos podem fazer emergir o conhecimento primeiro dos educandos no que se refere a grandezas e medidas , legitimando-os e procurando formas de dialogar com os educandos. Os dados/fatos foram coletados a partir de entrevistas com oito educandos de uma 6ª série (sete encontros) da Escola Estadual Antonio Candido Correa Guimarães Filho. Em cada encontro era esperado que uma questão associada a grandezas e medidas desencadeasse um processo gerador/problematizador em busca dos conhecimentos (primeiro) dos alunos. Os princípios da etnomatemática e as idéias de Paulo Freire, assim como teorizações sócio-construtivistas, constituíram os fundamentos da pesquisa. No que se refere às evidências de pesquisa, podemos, de início, dizer que as manifestações dos alunos estão envolvidas mais por uma arte ao formular, resolver e buscar aplicações em termos de grandezas e medidas do que por uma compreensão mais ou menos técnica da maneira como se mede; tomam-se padrões para esta ou aquela grandeza; como se os organizam e opera-se com eles. Em termos de conclusão, vale ressaltar que o exercício feito pela pesquisadora de operacionalização de atitudes, de busca e valorização do conhecimento primeiro que aqui já se mostrou voltada para os estudos etnomatemáticos, especialmente no que se refere a o que o outro pensa, como o outro vê ativou mais e mais o olhar da pesquisadora para processos de cunho etnomatemático tanto no âmbito pedagógico como em termos de pesquisa. / This paper, a research of the type qualitative, has as an aim the understanding of how mathematics educators can bring forth the first knowledge (previous knowledge) of the learners regarding quantities and measures , legitimizing them and looking for ways to dialogue with the students. The data/facts were collected from the interviews with eight 6th grade students (seven meetings) of the State School Antonio Candido Correa Guimarães Filho. In each meeting it was expected that a question related to quantities and measures would trigger a generating/problematizing process in search of the knowledge (the first one) of the students. The principles of ethnomathematics and Paulo Freire\'s ideas as well as socioconstructivist theories constituted the basis of the research. Regarding the research evidences we can say, initially, that the students\' answers are involved more by an art when posing, solving and looking for applications in terms of quantities and measures, than by a more or less technical understanding of the way one measures, defines standards for this or that quantity, organizes them and works with them. In general, the research development allowed us to conclude that it is worth to emphasize that the exercise of the operationalization of attitudes, by the researcher, the quest for and the appreciation of first knowledge - that here has already shown itself focusing on ethnomathematics studies, especially with regard to what the \"other\" thinks, how the \"other\" sees - more and more enabled the researcher to look at the processes of an ethnomathematics nature both within the pedagogical scope as in terms of research.
19

Nový koncept řešení světlovodiče – 2K systém / A new concept of a light guide – 2K system

Filip, Vojtěch January 2018 (has links)
The paper target is design of a conceptual solution of a two-component light-guide with the use of available materials, commonly used for the production of headlamp components, emphasizing the simplicity of the whole solution. The result will be in production of a prototype and the subsequent testing of its functional parameters using standard equipment for the measurement of photometric quantities.
20

Strojové zpracování časoprostorových dat pro potřeby územního plánování. / Machine processing of space-time data for spatial planning.

Brožek, Jan January 2020 (has links)
The diploma thesis deals with the processing of raw data from vehicle tracking by means of GPS in order to obtain traffic quantities as a possible source of data for traffic surveys and subsequent analysis in the field of traffic modeling.

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