Tese (doutorado)—Universidade de Brasília, Faculdade de Educação, Programa de Pós-Graduação em Educação, 2016. / Submitted by Fernanda Percia França (fernandafranca@bce.unb.br) on 2016-12-02T14:56:08Z No. of bitstreams: 1 2016_ShirleyMargarethBuffondaSilva.pdf: 3222308 bytes, checksum: 53786de30dcdc460dc998b2007a9771d (MD5) / Approved for entry into archive by Patrícia Nunes da Silva(patricia@bce.unb.br) on 2017-01-26T10:54:28Z (GMT) No. of bitstreams: 1 2016_ShirleyMargarethBuffondaSilva.pdf: 3222308 bytes, checksum: 53786de30dcdc460dc998b2007a9771d (MD5) / Made available in DSpace on 2017-01-26T10:54:28Z (GMT). No. of bitstreams: 1 2016_ShirleyMargarethBuffondaSilva.pdf: 3222308 bytes, checksum: 53786de30dcdc460dc998b2007a9771d (MD5) / Esta tese é o resultado de uma investigação realizada com estudantes no 2º ano do ensino médio em uma escola pública do Distrito Federal. O objetivo foi desenvolver sequências didáticas com a introdução de questões sociocientíficas (QSC) relativas a dilemas da biotecnologia que envolvem aspectos morais, visando caracterizar implicações pedagógicas para tratar questões morais no ensino de Biologia. Para isso, foram identificados aspectos morais adotados pelos estudantes relativos às QSC, antes, durante e depois da discussão dos dilemas, com o propósito de encontrar possíveis indicadores da relação entre abordagem de QSC e aspectos morais. A investigação tomou como referência pesquisas empíricas e estudos sobre inserção curricular de QSC e moral, bem como estudos no campo da psicologia e da filosofia. As sequências didáticas desenvolvidas foram sobre os seguintes dilemas morais: alimentos transgênicos, clonagem e terapia gênica. As teorias morais normativas e a metaética foram o referencial teórico utilizado na análise dos dados. No caso dos princípios morais nos embasamos na Declaração Universal de Bioética e dos Direitos Humanos e Valores do Espírito do Desporto. Foi realizada uma abordagem investigativa de cunho qualitativo utilizando-se a análise textual discursiva para identificar categorias emergentes nos discursos dos atores, obtidos por meio de questionários, entrevistas e após o desenvolvimento de uma sequência didática com discussões de QSC. Os dados construídos apontaram que a maioria dos estudantes interpreta QSC sobre temas da biotecnologia com base nas teorias morais deontológica e utilitarista e também no ceticismo moral. Nas QSC sobre alimentos transgênicos a moral utilitarista foi a mais utilizada. Já no caso da clonagem e da terapia gênica a moral deontológica foi predominante, com um pequeno número de estudantes que apresentaram ceticismo moral. Nesse contexto, percebemos que as aplicações da biotecnologia abordadas foram analisadas de formas diferentes em termos de moralidade por parte dos estudantes, e que fatores como o contexto, emoções, existência de valores protegidos e sagrados podem ter influenciado o julgamento moral. Além disso, concluímos que com a realização da sequência didática houve mudanças nas percepções dos estudantes quanto a algumas categorias utilizadas na análise como, uso de alimentos transgênicos, consciência ecológica e percepção de risco. Os dados demonstram também que não houve uma mobilização significativa dos estudantes nos debates das QSC. A análise do desenvolvimento das sequências didáticas aponta dificuldades para se incluir aspectos morais em discussões de QSC, tais como a inserção de atividades didáticas apropriadas para desenvolver a participação dos estudantes em QSC e o contexto curricular da escola. Defendemos como tese que a introdução de aspectos morais em QSC é essencial no ensino de Biologia para que se prepare os estudantes na tomada de decisão moral. Para que isso ocorra no contexto curricular da maioria das escolas brasileiras, muitos desafios precisam ser enfrentados tais como a formação de professores e o desenvolvimento de estratégias de ensino variadas dentro da diversidade de cenários existentes. Em síntese, esta investigação identificou elementos para o entendimento de como discussões de QSC no ensino de Biologia podem contribuir para o favorecimento do raciocínio moral dos estudantes. / This thesis is the result of an investigation carried out with students in the 2nd year of high school in a public school in the Federal District. The goal was to develop didactic sequences with the introduction of socio-scientific issues (SSI) concerning biotechnology dilemmas involving moral aspects, aiming to characterize pedagogical implications to address moral issues in Biology teaching. To achieve this goal, moral aspects adopted by students regarding SSI were identified, before, during and after the discussion of the dilemmas in order to find out possible indicators of the relationship between SSI approach and moral issues. The investigation used, as reference, empirical researches and studies on curricular inclusion of SSI and moral, as well as studies on moral in the fields of psychology and philosophy. The developed didactic sequences involved the following moral dilemmas regarding biotechnology SSI: GM food, cloning and gene therapy. The normative moral theories and meta-ethics were the theoretical framework used in the data analysis. In the case of moral principles we relied on the principles of the Universal Declaration of Bioethics and of Human Rights, and in the case of genetic doping, on the Values of Sport Spirit. An investigative approach of qualitative nature, using discursive textual analysis, was performed to identify emerging categories in the speeches of the actors, obtained through questionnaires, interviews and after the development of a didactic sequence with SSI discussions. The obtained data showed that most students interpret SSI on biotechnology having as a basis moral deontological, utilitarian theories and moral skepticism. In SSI on GM food utilitarian moral was the most used. In the case of cloning and genetic therapy, deontological moral was predominant. A small number of students showed moral skepticism. In this context, we realize that the discussed applications of biotechnology were analyzed in different ways, in terms of morality, by part of the students, and that factors such as the context, emotions, existence of protected and sacred values may have influenced their moral judgment. Furthermore, we noticed that, with the completion of the didactic sequence, there were changes in the perceptions of the students regarding some categories used in the analysis, such as the use of GM food, ecological awareness and risk perception. The data also show that there was not a significant mobilization of the students in the SSI discussions. The analysis of the development of the didactic sequences points out several difficulties to introduce moral aspects in SSI discussions, such as appropriate didactic activities to develop the participation of the students in SSI and the curricular context of the school. We defend the thesis that the introduction of moral aspects of SSI is essential in Biology teaching to prepare students for in their moral decision-making. To attain this goal, in the curricular context of most Brazilian schools, many challenges need to be faced, such as teachers’ proficiency and the development of various teaching strategies within the diversity of the actual scenarios. In summary, this research identified elements for understanding how SSI discussions in Biology teaching may contribute to foster the moral reasoning of the students.

In order to improve the performance of simulation and the convenience of use with OSCI TLM-2.0 Standard on QEMU and SystemC based virtual platform we proposed previously called QSC, this thesis presents a novel approach for integrating OSCI TLM-2.0 with QSC. By moving the OSCI TLM-2.0 interconnect bus outside of the Bus Function Model (BFM), the proposed approach can not only accelerate the simulation speed but also make it easy to add OSCI TLM-2.0 based Intellectual Properties (IPs) to the QSC. Experimental results show that the proposed approach can speed up all the simulations by a factor from 2.8 up to 3.255 on average when compared with the previous approach.

Tese (doutorado)—Universidade de Brasília, Faculdade de Educação, Programa de Pós-Graduação em Educação, 2016. / Submitted by Fernanda Percia França (fernandafranca@bce.unb.br) on 2016-05-20T16:40:57Z No. of bitstreams: 1 2016_KarolinaMartinsAlmeidaeSilva.pdf: 3238593 bytes, checksum: dbfb383329c112bebdc349f5eb3f8f5a (MD5) / Approved for entry into archive by Raquel Viana(raquelviana@bce.unb.br) on 2016-05-20T17:12:27Z (GMT) No. of bitstreams: 1 2016_KarolinaMartinsAlmeidaeSilva.pdf: 3238593 bytes, checksum: dbfb383329c112bebdc349f5eb3f8f5a (MD5) / Made available in DSpace on 2016-05-20T17:12:27Z (GMT). No. of bitstreams: 1 2016_KarolinaMartinsAlmeidaeSilva.pdf: 3238593 bytes, checksum: dbfb383329c112bebdc349f5eb3f8f5a (MD5) / O presente trabalho, de cunho teórico, teve por objetivo delinear, a partir do pensamento complexo, princípios epistêmicos teórico-estratégicos orientadores nas discussões sobre Questões Sociocientíficas (QSC) em aulas de ciências. Nesse sentido, os estudos foram direcionados em duas dimensões complementares: a dimensão epistêmica e a didático-pedagógica, sendo que, cada uma delas comporta elementos teórico-reflexivos voltados à análise da natureza complexificada das QSC. Para tanto, inicialmente, definiu-se as ligações conceituais das QSC e da Educação Ciência-Tecnologia-Sociedade (CTS) em uma via de “complementariedade objetiva específica” visto que, objetivamente denotam abordagens complementares no que se refere aos propósitos gerais acerca da educação científica e porque as QSC possuem objetivações específicas, no caso, a evidente expressão dos valores nos julgamentos das controvérsias. Também realizou-se uma leitura sistemática dos documentos curriculares oficiais e identificou-se que os mesmos sinalizam aspectos sociocientíficos relacionados à abordagem das inter-relações CTS, bem como a importância da contextualização histórica, social e cultural. Em continuidade, uma revisão ampla das pesquisas sobre QSC no contexto internacional e nacional foi realizada no intuito de caracterizar seus elementos conceituais e metodológicos. A análise indicou que as pesquisas expressam um caráter fundamentalmente metodológico visto que em sua maioria, estão voltadas à compreensão e análise da qualidade das argumentações, de interações discursivas e apropriação do conhecimento científico. Desse modo, a complexificação das QSC objetivamente as situam enquanto unidades complexas em relação ao seu estatuto epistêmico e às suas competências formativas. Nesse sentido, a natureza epistêmica das QSC foi caracterizada neste trabalho pela relação de três elementos conceituais: a) científico-tecnológico: denota as inter-relações CTS; b) valorativo: explicita os valores éticos e morais e; c) multidisciplinar: representa a multiplicidade de saberes. Assim, a base da proposta didático-pedagógica foi construída por meio de quadros de estudo em uma via organizacional dos conceitos voltados à relação entre as dimensões epistêmica e didático-pedagógica por meio de descrições dos indicadores que as configuram, e por isso compreendidos como “princípios teórico-estratégicos”. Os princípios compõem o “Quadro de Referência” para a complexificação das QSC e foram assim caracterizados: 1) Natureza das QSC; 2) Situação problemática; 3) Contexto histórico-sócio-cultural; 4) Conhecimento pertinente; 5) Fundamentos Formativos Identitários e; 6) Estratégias organizacionais. Vale ressaltar que a complexificação das QSC perpassa pela fundamentação e caracterização dos elementos que consubstanciam a natureza epistêmica e seus aspectos relacionais com vistas a abordagem estratégica. Isso intencionalmente ressignifica a importância em se considerar as controvérsias das QSC na perspectiva da complexidade quando abordadas em aulas de ciências. Além disso, a significação didático-pedagógica compreende os princípios teórico-estratégicos em uma via de mão-dupla, ou seja, como “ponto de partida” na orientação do planejamento estratégico e, na objetivação das discussões de controvérsias sociocientíficas. Assim sendo, os princípios teórico-estratégicos passarão a ser efetivamente coordenados e relacionados uma vez que os docentes adquiram percepções mais conscientes acerca da perspectiva da complexidade em um processo investigativo gradual mediante a implementação e experiência de formas concretas de intervenção, tendo como referência a realidade da sua sala de aula. / The current project of theoretical nature has aimed to outline, as, theoretical-strategic epistemic principles based on the discussions of the socio-scientific issues (QSC) in science classes. In this sense, the studies were directed in two complementary dimensions: epistemic and didactic-pedagogic dimensions and each involves theoretical-reflective elements aimed to analyzing the complex nature of the QSC. Therefore, the QSC conceptual connections were initially set up and Education Science-Technology-Society (STS) by means of “specific objective complementary”, as objectively, denote complementary approaches regarding general purposes about science education and reasons for QSC having specific objectivities; in this case, the clear expression of the dispute trial values. There was also a systematic reading of the official curriculum documents and it was identified that they present social-scientific aspects related to the CTS interrelations approach as well as the importance of the historical, social and cultural context. Furthermore, a further research review on QSC in international and national contexts was conducted in order to characterize its conceptual and methodological elements. This analysis indicated that research expresses a fundamentally methodological character, since, in most cases, they are aimed to understanding and analyzing the argument quality, discursive interactions and scientific knowledge appropriation. Thus, objectively, the QSC complexity is situated as complex units in relation to its epistemic status and its training skills. In this sense, the QSC epistemic nature was characterized in this project by the means of three conceptual elements: a) scientific and technological: denotes the CTS interrelations; b) evaluative: explicit ethical and moral values c) multidisciplinary: represents the knowledge multiplicity. Therefore, the basis of didactic-pedagogic proposal was built by means of study groups in an organized concept manner focused on the relationship between epistemic and didactic and pedagogic dimensions by descriptive indicators that make up and therefore understood as “theoretical and strategic principles”. The principles make up the “Framework” for the complexity of QSC and were characterized as follows: 1) Nature of QSC; 2) Problematic situation; 3) historical and socio-cultural context; 4) relevant knowledge; 5) Identity Formed Fundamentals and 6) organizational strategies. It is worth observing that the complexity of QSC runs through the foundation and characterization of the elements that embody the epistemic nature and its relational aspects with a view to strategic approach. This intentionally reframes the importance of considering the controversies of QSC in view of the complexity when covered in science classes. Moreover, the didactic-pedagogic significance comprises the theoretical and strategic principles in a two-way route, that is, as “starting point” in guiding the strategic planning and objectification of the discussions of socio-scientific controversies. Thus, the theoretical and strategic principles will be effectively coordinated and related to the extent that teachers acquire more conscious perceptions on the complexity perspective in a gradual investigative process to the implementation and experience of concrete forms of intervention, taking into consideration the classroom reality.

Submitted by Mario BC (mario@bc.ufrpe.br) on 2018-08-21T13:24:55Z No. of bitstreams: 1 Wilka Karla Martins do Vale.pdf: 1921204 bytes, checksum: 7267f50f2596ceb17077dd4da98a12f2 (MD5) / Made available in DSpace on 2018-08-21T13:24:55Z (GMT). No. of bitstreams: 1 Wilka Karla Martins do Vale.pdf: 1921204 bytes, checksum: 7267f50f2596ceb17077dd4da98a12f2 (MD5) Previous issue date: 2017-02-22 / The SSI Approach can support science teachers in discussions about the interactions between science, technology and society by promoting the opportunity to explore in these interactions their political, social, environmental, ethical, and other dimensions. In addition, in the present study we aimed to understand how the appropriation and objectification of the SSI Approach by science teachers in a process of teacher training within the scope of a discipline on the STS Guidance for the teaching-learning process occurs. We conducted this study based on the theoretical and methodological assumptions of the SSI Approach, in some relevant aspects of the formation of science teachers, and in some theoretical and methodological assumptions of Cultural Historical Activity Theory. In this direction, the study had a qualitative nature and followed different methodological steps, such as, for example, elaboration of a formative didactic experiment, analysis of conceptions and analysis of activities carried out by the participating teachers. The analytical movement initially considered the identification of the previous conceptions of teachers about the SSI approach, before the experience of the formative didactic experiment. In sequence, we analyzed the development of the formative didactic experiment in light of the elements of the system of activity proposed by Engestrom. In the sequence, we analyzed two concrete products of the activities carried out by the teachers, which were flowcharts and lesson plans. Finally, teachers' answers to the questions of an individual interview were analyzed. The results of the analysis indicate that teachers evolved in some aspects identified in their initial conceptions, that the formative didactic experiment consisted of multiple mediating instruments, such as texts, discussions, rules and division of labor, that inserted characteristics of the A SSI approach to constructed flowcharts and elaborated teaching plans, such as didactic strategies that enable the initiation of socio-scientific argumentation, and that the training experiment contributed to the understanding of these teachers about the SSI Approach. In addition, it was possible to understand how the processes of appropriation and objectification of the SSI Approach occurred by the teachers involved in the research. In this direction, we can consider that, among other aspects, the set of activities carried out by the teachers, the performance of individual and collective actions, the discussions promoted, and the development of activities that reproduced essential features of the SSI Approach, such as Activity of construction of flowcharts, elucidate that the teachers were in the process of appropriation. And as a relation of appropriation to objectification is dialectical, when teachers constructed concrete products, from actions and reflections, for example on how to construct a flow chart and a lesson plan with characteristics of the SSI Approach, teachers were in process Of objectification. These results lead us to believe that it is important to invest in the initial and continuing training of science teachers in the SSI approach, in view of the fact that this approach corroborates objectives that are critical to the scientific and technological literacy of students, as well as Ethical and moral development. / A Abordagem de QSC pode subsidiar os professores de ciências nas discussões sobre as interações entre ciência, tecnologia e sociedade promovendo oportunidade de explorar nestas interações suas dimensões políticas, sociais, ambientais, éticas etc. Neste contexto, no presente estudo tivemos o objetivo de compreender como ocorre a apropriação e objetivação da Abordagem de QSC por professores de ciências em um processo de formação docente no âmbito de uma disciplina sobre a Orientação CTS para o processo de ensino-aprendizagem. Conduzimos este estudo fundamentadas nos pressupostos teóricos e metodológicos da Abordagem de QSC, em alguns aspectos relevantes da formação de professores de ciências, e em alguns pressupostos teóricos e metodológicos da Teoria da Atividade Histórico Cultural. Nesta direção, o estudo teve natureza qualitativa e seguiu diferentes etapas metodológicas, como, por exemplo, elaboração de um experimento didático formativo, análise de concepções e análises de atividades realizadas pelos professores participantes. O movimento analítico considerou inicialmente a identificação das concepções prévias de professores sobre a abordagem de QSC, antes da vivência do experimento didático formativo. Em sequência, analisamos o desenvolvimento do experimento didático formativo a luz dos elementos do sistema de atividade propostos por Engestrom. Na sequência, analisamos dois produtos concretos das atividades realizadas pelos professores quais foram, os fluxogramas e planos de aula. Finalmente, respostas dos professores às questões de uma entrevista individual foram analisadas. Os resultados da análise indicam que os professores evoluíram quanto a alguns aspectos identificados em suas concepções iniciais, que o experimento didático formativo foi constituído de múltiplos instrumentos mediadores, como, por exemplo, textos, discussões, que inseriram características da Abordagem de QSC nos fluxogramas construídos e nos planos de ensino elaborados, como, por exemplo, estratégias didáticas que possibilitam o desencadear da argumentação sociocientífica, e que o experimento formativo contribuiu para a compreensão desses professores sobre a Abordagem de QSC. Além disso, foi possível compreender como ocorreram os processos de apropriação e objetivação da Abordagem de QSC pelos professores envolvidos na pesquisa. Nesta direção, podemos considerar que, entre outros aspectos, o conjunto das atividades realizadas pelos professores, a realização de ações individuais e coletivas, as discussões promovidas, e desenvolvimento de atividades que reproduziram traços essenciais da Abordagem de QSC, como, por exemplo, a Atividade de construção de fluxogramas elucida que os professores estavam em processo de apropriação. E como relação da apropriação com a objetivação é dialética, quando os professores construíram produtos concretos, a partir de ações e reflexões, por exemplo, de como construir um fluxograma e um plano de aula com características da Abordagem de QSC, os professores estavam em processo de objetivação. Esses resultados nos levam a crer que é relevante investir em processos de formação inicial e continuada de professores de ciências para a abordagem de QSC com vista que essa abordagem corrobora com objetivos que prezam a formação crítica e o letramento científico e tecnológico dos alunos, assim como seu desenvolvimento ético e moral.

Tese (doutorado)—Universidade de Brasília, Faculdade de Educação, Programa de Pós-Graduação em Educação, 2016. / Submitted by Fernanda Percia França (fernandafranca@bce.unb.br) on 2016-07-25T12:20:03Z No. of bitstreams: 1 2016_MarcosFernandesSobrinho.pdf: 8023100 bytes, checksum: 006c2341890465b79975db1551eba030 (MD5) / Approved for entry into archive by Raquel Viana(raquelviana@bce.unb.br) on 2016-07-29T12:43:47Z (GMT) No. of bitstreams: 1 2016_MarcosFernandesSobrinho.pdf: 8023100 bytes, checksum: 006c2341890465b79975db1551eba030 (MD5) / Made available in DSpace on 2016-07-29T12:43:47Z (GMT). No. of bitstreams: 1 2016_MarcosFernandesSobrinho.pdf: 8023100 bytes, checksum: 006c2341890465b79975db1551eba030 (MD5) / O estudo se insere nos contextos do Exame Nacional do Ensino Médio (Enem) e do livro didático de Física (LDF) em que procuramos realçar a importância da educação científico-tecnológica, com percepção e entendimento da natureza, consoante ao mundo social. Essa educação pressupõe atividades de ensino-aprendizagem, reconhecidamente importantes, ponderadas sobre (e a partir) de discussões de questões sociocientíficas (QSC) capazes de induzir à formação cidadã. Apesar de a literatura recomendá-las fortemente, aponta dificuldades para trabalhá-las. Isso posto, objetivamos ampliar o número [e o acesso] de fontes e gêneros textuais, como alternativas viáveis, na perspectiva de contribuir com a implementação de discussões de QSC, no ensino. Nesse sentido, identificamos, analisamos e sistematizamos indicadores, nos itens do Enem e em textos de LDF, capazes de potencializar articulações de discussões de temas sociocientíficos (TSC), considerando a voz do professor-sujeito de Física. Tomamos dimensões que envolvem a problemática relacionada à escola pública estadual de ensino médio, no que tange: (1) a presença (ou não) de itens e de textos com potencial para TSC, no exame e nos LDF, e seus reflexos na sala de aula; (2) o fato de o Enem cada vez mais se configurar como forma de acesso às vagas de ensino superior no Brasil; o que induz reestruturação dos currículos e impacta, de alguma forma, a “vida” da escola; e (3) a relevância dos itens do Enem e do LDF, no planejamento e na execução da atividade docente. Elegemos, então, uma unidade da federação do Centro-Oeste como campo da pesquisa cujo locus é constituído por seis municípios do interior, entre os quais selecionamos 12 escolas. Os procedimentos investigativos, de cunhos quali e quantitativo e documental, enquadram-se nos escopos teórico e empírico. Utilizamos instrumentos e técnicas para a tomada de dados (questionário, entrevista, gravações em áudio, microdados), tratados por elementos da análise de conteúdo e da estatística descritiva. Os dados sinalizam que, apesar de os professores recorrerem a itens do Enem e a textos de LDF para planejar e ministrar atividades pedagógicas, o fazem de maneira acrítica e com ênfase em algoritmos, muitas vezes deslocados de significância aos estudantes. Análises dos microdados sugerem associação negativa do desempenho dos estudantes, ao perfil dos professores e a itens com potencial para TSC. Dado que os resultados parecem falsear a realidade do contexto escolar, a aludida dificuldade foi, então, desmontada teórica e empiricamente, revelando-se potencialmente minimizada com o estabelecimento de trilhas que possibilitam o professor trabalhar discussões, a partir de TSC, identificados em materiais de fácil e universal acesso. Faz-se necessário, além de possível, favorecer o desenvolvimento da capacidade de reconhecer aspectos fundantes da infraestrutura do que se lê para, então, extrapolar e desenvolver competências latentes e pertinentes, na busca da função que o texto tem de desencadear os propósitos e os desdobramentos das discussões de QSC. Ainda que, atualmente, predominem ações pedagógicas carregadas de singularidades propedêuticas, defendemos um ensino educativo de Física, receptivo às potencialidades de articulações, entre as quais destacamos aquelas pautadas em discussões de QSC. _______________________________________________________________________________________________ ABSTRACT / This paper focuses on the contents on the National Secondary Education Examination (Enem) and of Physics textbooks (PT), aiming to highlight the importance of scientific-technological teaching, with the perception and understanding of nature in the social world. This type of education presumes activities of teaching and learning, which are admittedly important and which should be based on discussions of socio-scientific issues (SSI) able to lead to the education of the citizen. Although the technical literature recommends such activities, it also points out the difficulties in developing them. Thus, we aimed at increasing the number of [and the access to] sources and genres as feasible alternatives, so as to contribute to the implementation of SSI discussions in teaching. In this sense, we identified, analyzed and systematized indicators both on Enem and in the PT that could enhance interactions across socio-scientific themes (SST), considering the voice of the Physics teacher. We analyzed the dimensions that involve the problem related to public secondary schools, regarding these aspects: (1) the presence (or not) of items and texts with potential to SST, both in the examination and in the PT, and their consequences in the classroom; (2) the fact that Enem has become a way to gain entrance to universities in Brazil; which leads to a reorganization of the syllabi and somehow impacts the school's "life"; and (3) the relevance of the items on Enem and in the PT to lesson planning and execution. Therefore, we chose a State in Brazil's Central West region as our field of research, whose locus consists of 12 schools selected from six towns. This study combines qualitative and quantitative research, containing document analysis, and it fits in the theoretical and empirical scopes. We used some data collection tools and techniques (questionnaires, interviews, audio recordings, micro-data), which were treated by elements of content analysis and descriptive statistics. The data showed that, despite resorting to the items found on Enem and in the PT textbooks to plan and teach the lessons, teachers usually do so in a non-critical way and they give emphasis to algorithms, which are frequently meaningless to students. Micro-data analyses suggest a negative relationship between students' performance, teachers' professional profile and items with potential to SST. Since the results seem to distort the reality of the school environment, the alluded difficulty was therefore dismissed theoretically and empirically, becoming potentially minimized by establishing ways that make it possible for the teacher to promote discussions based on SST identified in materials easily accessed. It is possible and necessary to foster the development of the ability to recognize infrastructural fundamental aspects of what it is being read, so that one can surpass them and develop latent and pertinent skills, in the search of the text's objective in instigating the SSI's purpose and unfolding their discussions. The educational actions that are made up of with basic singularities currently predominate. However, we defend an educative teaching of Physics, receptive to the potentialities of interactions, among which we highlight those based on SSI discussions.

<p> Novel scalar and full-vectorial mode solvers based on quadratic spline collocation (QSC) method have been developed in MATLAB for optical dielectric waveguide with arbitrary two-dimensional cross-section and refractive index profile.</p> <p> Compared with the conventional finite difference mode solver in the literature and a commercial mode solver, the QSC mode solvers are simple and easy to implement in MATLAB without losing the accuracy of the mode solutions. The scalar mode solver is fast for solving weakly guiding waveguides. Three typical rib waveguides are calculated by the QSC scalar mode solver and compared with the numerical results of a finite difference scalar mode solver in the literature. The full-vectorial mode solver is capable of solving both weakly and strongly guiding waveguides. Typical numerical examples are calculated by the full-vectorial QSC mode solver and the solver is verified by comparing the results to a commercial mode solver.</p> <p> At the end of the thesis, methods of calculating leaky and radiation modes of general dielectric waveguides and possible methods of increasing the accuracy of the QSC mode solvers are proposed.</p> / Thesis / Master of Applied Science (MASc)

This thesis presents the results and analyses of computational studies on certain problems of combustion instability in solid propellants. Specifically, effects of relaxing certain assumptions made in previous models of unsteady burning of solid propellants are investigated. Knowledge of unsteady burning of solid propellants is essential in studying the phenomenon of combustion instability in solid propellant rocket motors. In Chapter 1, an introduction to different types of unsteady combustion investigated in this thesis, such as 1) intrinsic instability, 2) pressure-driven dynamic burning, 3) extinction by depressurization, and 4) L* -instability, is given. Also, a review of previous experimental and theoretical studies of these phenomena is presented. From this review it is concluded that all the previous studies, which investigated the unsteady combustion of solid propellants, made one or more of the following assumptions: 1) quasi-steady gas-phase (QSG), 2) quasi-steady condensed phase reaction zone (QSC), 3) small perturbations, and 4) unity Lewis number. These assumptions limit the validity of the results obtained with such models to: 1) relatively low frequencies (< 1 kHz) of pressure oscillations and 2) small deviations in pressure from its steady state or mean values. The objectives of the present thesis are formulated based on the above conclusions. These are: 1) to develop a nonlinear numerical model of unsteady solid propellant combustion, 2) to relax the assumptions of QSG and QSC, 3) to study the consequent effects on the intrinsic instability and pressure-driven dynamic burning, and 4) to investigate the L* -instability in solid propellant rocket motors. In Chapter 2, a nonlinear numerical model, which relaxes the QSG and QSC assumptions, is set up. The transformation and nondimensionalization of the governing equations are presented. The numerical technique based on the method of operator-splitting, used to solve the governing equations is described. In Chapter 3, the effect of relaxing the QSG assumption on the intrinsic instability is investigated. The stable and unstable solutions are obtained for parameters corresponding to a typical composite propellant. The stability boundary, in terms of the nondimensional parameters identified by Denison and Baum (1961), is predicted using the present model. This is compared with the stability boundary obtained by previous linear stability theories, based on activation energy asymptotics in the gas-phase, which employed QSC and/or QSG assumptions. It is found that in the limit of large activation energy and low frequencies, present result approaches the previous theoretical results. This serves as a validation of the present method of solution. It is confirmed that relaxing the QSG assumption widens the stable region. However, it is found that a distributed reaction in the gas-phase destabilizes the burning. The effect of non-unity Lewis number on the stability boundary is also investigated. It is found that at parametric values corresponding to low pressures and large flame stand-off distances, small amplitude, high frequency (at frequencies near the characteristic frequency of the gas-phase) oscillations in burning rate appear when the Lewis number is greater than one. In Chapter 4, the effect of relaxing the QSG assumption is further investigated with respect to the pressure-driven dynamic burning. Comparison of the pressure-driven frequency response function, Rp, obtained with the present model, both in the QSG and non-QSG framework, with those obtained with previous linear stability theories invoking QSG and QSC assumptions are made. As the frequency of pressure oscillations approaches zero, |RP| predicted using present models approached the value obtained by previous theoretical studies. Also, it is confirmed that the effect of relaxing QSG is to decrease the |Rp| at frequencies near the first resonant frequency. Moreover, relaxing QSG assumption produces a second resonant peak in |Rp| at a frequency near the characteristic frequency of the gas-phase. Further, Rp calculated using the present model is compared with that obtained by a previous linear theory which relaxed the QSG assumption. The two models predicted the same resonant frequencies in the limit of small amplitudes of pressure oscillations. Finally, it is found that the effect of large amplitude of pressure oscillations is to introduce higher harmonics in the burning rate and to reduce the mean burning rate. In Chapter 5, first the present non-QSC model is validated by comparing its results with that of a previous non-QSC model for radiation-driven burning. The model is further validated for steady burning results by comparing with experimental data for a double base propellant (DBP). Then, the effect of relaxing the QSC assumption on steady state solution is investigated. It is found that, even in the presence of a strong gas-phase heat feedback, QSC assumption is valid for moderately large values of condensed phase Zel'dovich number, as far as steady state solution is concerned. However, for pressure-driven dynamic burning, relaxing the QSC assumption is found to increase |RP| at all frequencies. The error due to QSC assumption is found to become significant, either when |Rp| is large or as the driving frequency approaches the characteristic frequency of the condensed phase reaction zone. The predicted real part of the response function is quantitatively compared with experimental data for DBP. The comparison seems to be better with a value of condensed phase activation energy higher than that suggested by Zenin (1992). In Chapter 6, burning rate transients for a DBP during exponential depressurization are computed using non-QSG and non-QSC models. Salient features of extinction and combustion recovery are predicted. The predicted critical initial depressurization rate, (dp/dt)i, is found to decrease markedly when the QSC assumption is relaxed. The effect of initial pressure level on critical (dp/dt)i is studied. It is found that the critical (dp/dt)i decreases with the initial pressure. Also, the overshoot of burning rate during combustion recovery is found to be relatively large with low initial pressures. However as the initial pressure approached the final pressure, the reduction in initial pressure causes a large increase in the critical (dp/dt)i. No extinction is found to occur when the initial pressure is very close to the final pressure. In Chapter 7, a numerical model is developed to simulate the L* -instability in solid propellant motors. This model includes a) the propellant burning model that takes into account nonlinear pressure oscillations and that takes into account an unsteady gas- and condensed phase, and b) a combustor model that allows pressure and temperature oscillations of finite amplitude. Various regimes of L* -burning of a motor, with a typical composite propellant, namely 1) steady burning, 2) oscillatory burning leading to steady state, 3) oscillatory burning leading to extinction, 4) reignition and 5) chuffing are predicted. The predicted dependence of frequency of L* -oscillations on mean pressure is compared with one set of available experimental data. It is found that proper modeling of the radiation heat flux from the chamber walls to the burning surface may be important to predict the re-ignition. In Chapter 8, the main conclusions of the present study are summarized. Certain suggestions for possible future studies to enhance the understanding of dynamic combustion of solid propellants are also given.